![Page 1: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/1.jpg)
An Analysis of High-Impact, Low-Predictive Skill Severe Weather Events
in the Northeast U.S.
Matthew Vaughan, Brian Tang, and Lance Bosart
Department of Atmospheric and Environmental Sciences
University at Albany/SUNY
Albany, NY 12222
Master’s Thesis Seminar
Albany, NY
2 December 2015
Supported by the NOAA Collaborative Science, Technology and Applied Research Program (NA13NWS4680004)
![Page 2: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/2.jpg)
• Severe weather impacts on the Northeast
– Densely populated, major metropolitan areas
Motivation
Hurlbut and Cohen (2014)
![Page 3: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/3.jpg)
• Interstate 95 corridor from Boston through Washington D.C. = most densely populated region in U.S.
Motivation
2010 Census (census.gov)
![Page 4: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/4.jpg)
• Severe weather impacts on the aviation
– 8 of 25 busiest airports in the U.S. are found north of D.C. and east of Pittsburg, PA
Motivation
ARUP Canada
Weather caused 63.88% of all National Airspace System delays between 2003–2015 (www.transtats.bts.gov).
![Page 5: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/5.jpg)
• Severe weather impacts on the aviation
– 8 of 25 busiest airports in the U.S. are found north of D.C. and east of Pittsburg, PA
Motivation
ARUP Canada
![Page 6: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/6.jpg)
• Severe weather impacts on the aviation
– 8 of 25 busiest airports in the U.S. are found north of D.C. and east of Pittsburg, PA
Motivation
ARUP Canada
![Page 7: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/7.jpg)
• The Northeast provides a challenging forecast environment
– Complex terrain, lake-water boundaries
Motivation
maps-for-free.com
m
![Page 8: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/8.jpg)
BACKGROUND LITERATURE
![Page 9: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/9.jpg)
• Monthly climatology of severe reports in the Northeast (1999–2009)
Background
Hurlbut and Cohen (2014)
![Page 10: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/10.jpg)
• Monthly climatology of severe reports in the Northeast (1999–2009)
Background
Hurlbut and Cohen (2014)
![Page 11: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/11.jpg)
• Monthly climatology of severe reports in the Northeast (1999–2009)
Background
Hurlbut and Cohen (2014)
![Page 12: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/12.jpg)
• Recent research suggests MUCAPE is weaker for coastal Northeast severe linear events than non-severe MCSs in the Great Plains
Background
Lombardo and Colle (2011) [NARR reanalysis]
Coastal Northeast
![Page 13: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/13.jpg)
• Recent research suggests MUCAPE is weaker for coastal Northeast severe linear events than non-severe MCSs in the Great Plains
Background
Cohen et. al. (2007) [3-h proxy soundings] Lombardo and Colle (2011) [NARR reanalysis]
Coastal Northeast Great Plains
![Page 14: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/14.jpg)
Coastal Northeast
• Recent research suggests MUCAPE is weaker for coastal Northeast severe linear events than non-severe MCSs in the Great Plains
Background
Cohen et. al. (2007) [3-h proxy soundings] Lombardo and Colle (2011) [NARR reanalysis]
![Page 15: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/15.jpg)
• Northeast CAPE
– Hurlbut and Cohen (2014) used 6-h proximity soundings to evaluate Northeast severe weather environments
Background
Hurlbut and Cohen (2014) [6-h proximity soundings]
![Page 16: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/16.jpg)
• Northeast CAPE
– Majority of events have MLCAPE < 1000 J kg−1
Background
Hurlbut and Cohen (2014) [6-h proximity soundings]
![Page 17: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/17.jpg)
• Northeast deep-layer shear
– Bulk wind shear (0–6 km) medians for all events hovers between ~13–16 m s−1 (~25–31 kt)
Background
Hurlbut and Cohen (2014) [6-h proximity soundings]
![Page 18: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/18.jpg)
• Northeast deep-layer shear
– Bulk wind shear (0–6 km) medians for all events hovers between ~13–16 m s−1 (~25–31 kt)
Background
Hurlbut and Cohen (2014) [6-h proximity soundings]
![Page 19: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/19.jpg)
• Hitchens and Brooks (2012) verified SPC day-1 slight-risk convective outlooks over CONUS
– Found increased forecast performance with time
Background
• Black line represents slight-risk performance • Gray line represents moderate-risk performance
Source: Hitchens and Brooks(2012)
![Page 20: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/20.jpg)
• Found increasing severe report areal coverage with time
• Slight-risk outlook area peaks in 1994
– Trend suggests better FOH scores are due to well-placed, smaller risk areas
Background
• Black line represents annual slight-risk outlook area • Gray line represents severe report area Source: Hitchens and Brooks(2012)
![Page 21: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/21.jpg)
Research Goals
• Evaluate slight-risk forecast performance over the Northeast
• Build database of events with poor forecast skill
• Analyze environments conducive to poor forecast skill
![Page 22: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/22.jpg)
Research Goals
• Evaluate slight-risk outlook performance over the Northeast
![Page 23: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/23.jpg)
Methodology: Game Plan
• Establish Northeast domain to evaluate forecast skill
• Plot slight-risk convective outlook contours over the domain
• Evaluate outlooks with valid storm reports and compare to CONUS verification – Similar verification methodology to Hitchens
and Brooks (2012) • Mod and high contours within slight contours were included (i.e. everywhere inside the slight was
treated the same)
![Page 24: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/24.jpg)
Mod and High Outlooks Included
![Page 25: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/25.jpg)
Mod and High Outlooks Included
![Page 26: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/26.jpg)
Mod and High Outlooks Included
![Page 27: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/27.jpg)
Mod and High Outlooks Included
![Page 28: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/28.jpg)
Mod and High Outlooks Included
![Page 29: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/29.jpg)
Mod and High Outlooks Included
![Page 30: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/30.jpg)
Mod and High Outlooks Included
![Page 31: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/31.jpg)
Northeast Domain
![Page 32: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/32.jpg)
Northeast Domain
![Page 33: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/33.jpg)
Algorithm Example
![Page 34: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/34.jpg)
Algorithm Example
![Page 35: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/35.jpg)
Algorithm Example
![Page 36: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/36.jpg)
Algorithm Example
![Page 37: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/37.jpg)
Algorithm Example
![Page 38: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/38.jpg)
Algorithm Example
![Page 39: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/39.jpg)
Algorithm Example
![Page 40: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/40.jpg)
Algorithm Example
![Page 41: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/41.jpg)
Algorithm Example
![Page 42: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/42.jpg)
Contingency Table
Observed Y Observed N
Forecast (Y) Correct Hit (A)
False Alarm (B)
Forecast (N) Miss (C) Correct null (D)
0 ≤ POD ≤ 1, best score: POD = 1, best score ≠ perfect forecast
0 ≤ FAR ≤ 1, best score: FAR = 0, best score ≠ perfect forecast
0 ≤ TS ≤ 1, best score: TS = 1, best score = perfect forecast
Methodology: Evaluation
![Page 43: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/43.jpg)
SLIGHT-RISK SKILL SCORES
![Page 44: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/44.jpg)
Northeast and CONUS: TS
Median is plotted with the 25th and 75th percentiles in the
whiskers.
![Page 45: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/45.jpg)
Northeast and CONUS: Slight Risk Frequency
![Page 46: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/46.jpg)
Research Goals
• Build database of events with poor forecast skill
![Page 47: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/47.jpg)
Database Criteria
• For inclusion in the 1980–2013 database, an event must meet at least 1 of 2 criteria:
– Have a slight risk contour within the NE
domain
– Have a sufficiently high impact to warrant inclusion • How do we define “high impact”?
![Page 48: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/48.jpg)
0
20
40
60
80
100
120
140
160
1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012
Gri
dp
oin
ts (
Spat
ial A
rea)
Aff
ect
ed
Severe Impact Area per Slight Risk Event
Northeast Severe Report Trend
![Page 49: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/49.jpg)
0
20
40
60
80
100
120
140
160
1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012
Gri
dp
oin
ts (
Spat
ial A
rea)
Aff
ect
ed
Severe Impact Area per Slight Risk Event
Northeast Severe Report Trend
![Page 50: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/50.jpg)
0
20
40
60
80
100
120
140
160
1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012
Gri
dp
oin
ts (
Spat
ial A
rea)
Aff
ect
ed
Severe Impact Area per Slight Risk Event
Northeast Severe Report Trend
![Page 51: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/51.jpg)
0
20
40
60
80
100
120
140
160
1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012
Gri
dp
oin
ts (
Spat
ial A
rea)
Aff
ect
ed
Severe Impact Area per Slight Risk Event
Northeast Severe Report Trend
![Page 52: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/52.jpg)
• Event days = 1503
• Slight-risk days = 1300
• High-impact events without slight-risk = 203
High-Impact Database: Quick Stats
![Page 53: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/53.jpg)
TYPES OF LOW-PREDICTABILITY EVENTS
![Page 54: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/54.jpg)
Type 1 (Low POD) Example
Reports captured = 0 Reports missed = 200 POD = 0 FAR = N/A TS = 0
![Page 55: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/55.jpg)
•Low POD
Type 1
Types of Low Predictability Events
• Type 1 – High impact
– Lowest 25th percentile POD score
![Page 56: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/56.jpg)
Type 2 (High FAR) Example
Reports captured = 2 Reports missed = 0 POD = 1 FAR = .986 TS = .014
![Page 57: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/57.jpg)
• Type 1 – High impact
– Lowest 25th percentile POD score
• Type 2
– Highest 25th percentile FA area
– Lowest 25th percentile severe report area
•Low POD
Type 1
•High FAR
Type 2
Types of Low Predictability Events
![Page 58: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/58.jpg)
•Low POD
Type 1
•High FAR
Type 2
Types of Low Predictability Events
• Type 1
– High impact
– Lowest 25th percentile POD score
• Type 2
– Highest 25th percentile FA area
– Lowest 25th percentile severe report area
No events meet both requirements
![Page 59: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/59.jpg)
COLLECT EVENTS WITH GOOD FORECAST SKILL FOR COMPARISON
![Page 60: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/60.jpg)
•High TS
Good Event
Type of High Predictability Events
• Good Event – High impact
– Highest 25th percentile threat score
![Page 61: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/61.jpg)
HIGH-IMPACT, LOW-PREDICTIVE SKILL CLIMATOLOGY
![Page 62: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/62.jpg)
Annual Frequency
![Page 63: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/63.jpg)
Monthly Frequency
![Page 64: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/64.jpg)
Monthly Frequency
![Page 65: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/65.jpg)
Research Goals
• Evaluate environments conducive to poor forecast skill
![Page 66: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/66.jpg)
EVENT-CENTERED COMPOSITES
![Page 67: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/67.jpg)
Event Centering Technique
• 0.5° NCEP Climate Forecast System Reanalysis (CFSR) – Chose morning (1200 UTC) for synoptic analysis,
afternoon (1800 UTC) for severe weather parameter analysis
• Type 1 and Good forecast events centered on
the point of maximum report density • Composited April–September to capture majority
(93%) of high-impact events
• Type 2 events centered at centroid of the
slight-risk region
![Page 68: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/68.jpg)
Event Climatology
![Page 69: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/69.jpg)
Event Climatology
![Page 70: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/70.jpg)
Event Climatology
Numbers indicate raw number of events. Green line indicates expected value based on methodology.
![Page 71: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/71.jpg)
Event Climatology
Numbers indicate raw number of events. Green line indicates expected value based on methodology.
![Page 72: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/72.jpg)
SEVERE WEATHER PARAMETER ANALYSIS
(MUCAPE & DEEP-LAYER SHEAR)
![Page 73: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/73.jpg)
0
500
1000
1500
2000
2500
3000
3500
4000
0 10 20 30 40 50 60 70 80 90
MU
CA
PE
(J/k
g)
1000–500-hPa Shear Magnitude (kt)
Type 1 and Good Forecast Events
MUCAPE-Shear Phase Space
![Page 74: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/74.jpg)
0
500
1000
1500
2000
2500
3000
3500
4000
0 10 20 30 40 50 60 70 80 90
MU
CA
PE
(J/k
g)
1000–500-hPa Shear Magnitude (kt)
Type 1 and Good Forecast Events
MUCAPE-Shear Phase Space
![Page 75: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/75.jpg)
MUCAPE-Shear Phase Space
![Page 76: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/76.jpg)
MUCAPE-Shear Phase Space
![Page 77: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/77.jpg)
Threat Scores of High-Impact Events
Average threat scores of high-impact events occurring under low (< 31 kt) and high (≥ 31 kt) 1000–500-hPa shear. Whiskers are
confidence intervals at the 99% level.
![Page 78: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/78.jpg)
EXAMPLE CASE
![Page 79: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/79.jpg)
• Type 1 under-predicted storm
• SPC issued 5% wind outlook for Northeast
18 August 2009 Severe Wind Event (LSHC)
![Page 80: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/80.jpg)
Synoptic Overview 250 hPa 1600 UTC 18 August 2009
250-hPa geopotential height (dam, black contours), 250-hPa winds (knots, shaded and barbed), divergence (× 10−5 s−1, red contours)
![Page 81: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/81.jpg)
500-hPa geopotential height (dam, black contours), 500-hPa winds (knots, barbed), 500-hPa relative vorticity (×10−5 s−1, shaded)
Synoptic Overview 500 hPa 1600 UTC 18 August 2009
![Page 82: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/82.jpg)
700–500-hPa lapse rate (K/km, black contours), 1000–500-hPa shear (knots, barbed), surface-based CAPE(J/kg, shaded)
Synoptic Overview SBCAPE & shear 1600 UTC 18 August 2009
![Page 83: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/83.jpg)
• MLCAPE: 1948 J kg−1
• MLCIN: -167 J kg−1
• 6-km shear: 12 kt • 3-km shear: ~28 kt • DCAPE: 510 J kg−1
Morning Sounding: Convective Initiation
![Page 84: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/84.jpg)
• MLCAPE: 2192 J kg−1
• MLCIN: -233 J kg−1
• 6-km shear: 12 kt
• DCAPE: 1294 J kg−1
Morning Sounding: Severe Report Location
![Page 85: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/85.jpg)
DCAPE: 1294 J/kg
WAL Sounding Climatology
![Page 86: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/86.jpg)
Radar 1600 UTC 18 Aug
![Page 87: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/87.jpg)
Radar 1630 UTC 18 Aug
![Page 88: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/88.jpg)
Radar 1700 UTC 18 Aug
![Page 89: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/89.jpg)
Radar 1730 UTC 18 Aug
![Page 90: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/90.jpg)
Radar 1800 UTC 18 Aug
![Page 91: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/91.jpg)
Radar 1830 UTC 18 Aug
![Page 92: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/92.jpg)
Radar 1900 UTC 18 Aug
![Page 93: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/93.jpg)
Radar 1930 UTC 18 Aug
![Page 94: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/94.jpg)
Radar 2000 UTC 18 Aug
![Page 95: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/95.jpg)
Source: UCAR
Radar 2030 UTC 18 Aug
![Page 96: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/96.jpg)
Radar 2100 UTC 18 Aug
![Page 97: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/97.jpg)
Radar 2130 UTC 18 Aug
![Page 98: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/98.jpg)
Radar 2200 UTC 18 Aug
![Page 99: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/99.jpg)
Radar 2230 UTC 18 Aug
![Page 100: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/100.jpg)
Radar 2300 UTC 18 Aug
![Page 101: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/101.jpg)
Radar 0000 UTC 19 Aug
![Page 102: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/102.jpg)
Radar 0030 UTC 19 Aug
![Page 103: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/103.jpg)
Radar 0100 UTC 19 Aug
![Page 104: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/104.jpg)
Radar 0130 UTC 19 Aug
![Page 105: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/105.jpg)
Radar 0200 UTC 19 Aug
![Page 106: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/106.jpg)
Radar 0230 UTC 19 Aug
![Page 107: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/107.jpg)
Radar 0300 UTC 19 Aug
![Page 108: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/108.jpg)
Radar 2000 UTC 18 Aug
Surface parcel: T = 35 °C and TD = 17 °C
![Page 109: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/109.jpg)
Radar 0000 UTC 19 Aug
![Page 110: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/110.jpg)
77 kt wind gust at 0233 UTC
Radar 0000 UTC 19 Aug
• MLCAPE: 1945 J kg−1
• MLCIN: -178 J kg−1
• 6-km shear: 16 kt
• DCAPE: 1199 J kg−1
![Page 111: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/111.jpg)
77 kt wind gust at 0233 UTC
Radar 0000 UTC 19 Aug
• MLCAPE: 1945 J kg−1
• MLCIN: -178 J kg−1
• 6-km shear: 16 kt
• DCAPE: 1199 J kg−1
![Page 112: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/112.jpg)
• Low Shear High CAPE (LSHC) event.
– Weak synoptically forced environment – Orography and lake boundaries critical in convective
initiation – Convective initiation environment differed from
environment to the east where most severe reports occurred.
• Type 1 LSHC cases often feature storms propagating
into environments with higher PBL heights and greater DCAPE
• In the absence of strong low-to-mid level flow and large vertical wind shear, large DCAPE and high PBL heights likely contribute to the severe wind threat
Case Summary
![Page 113: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/113.jpg)
• Low-predictive skill climatology results:
– Northeast has better threat scores than CONUS – Peak in JJA for low-POD events, little yearly variation
• Most common under westerly, southwesterly, and northwesterly 500-hPa flow regimes
– High-FAR events not as common in recent years
• Composite results: – Deep-layer shear a significant predictive skill discriminator – Northerly, northwesterly, and southerly flow regimes have
lowest skill – Synoptic setup similar between good and low-POD cases but key
features (trough, baroclinicity, etc.) stronger in good cases
• Case study results: – Low-POD, low-shear events often propagate into higher-PBL,
higher-DCAPE environments – High shear, low CAPE low-POD events often exhibit insolation-
driven, high-PBL instability
General Summary
![Page 114: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/114.jpg)
• Family (parents, siblings Meghan and Chris)
• Drs. Lance Bosart & Brian Tang
• UAlbany faculty and staff
• Teachers at ERAU and in Berkshire County
• Fellow graduate students
Acknowledgements
![Page 115: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/115.jpg)
FIN
![Page 116: An Analysis of High-Impact, Low-Predictive Skill Severe ...bgmresearch.eas.cornell.edu/...Thesis_Presentation... · Master’s Thesis Seminar Albany, NY 2 December 2015 ... Hurlbut](https://reader033.vdocument.in/reader033/viewer/2022052005/6019786430662218961c0847/html5/thumbnails/116.jpg)
Northwesterly Flow Low-POD Event Conceptual Model