atcf requirements, intensity consensus sea heights consistent with nhc forecasts (progress report)
DESCRIPTION
ATCF Requirements, Intensity Consensus Sea Heights Consistent with NHC Forecasts (Progress Report). Presenter Buck Sampson (NRL Monterey) Investigators Ann Schrader, Efren Serra (SAIC, Monterey) Paul Wittmann (FNMOC) Hendrik Tolman (NCEP) Mike Frost (NRL, Monterey) Collaborators - PowerPoint PPT PresentationTRANSCRIPT
ATCF Requirements, Intensity Consensus
Sea Heights Consistent with NHC Forecasts
(Progress Report)
Presenter
Buck Sampson (NRL Monterey)
Investigators
Ann Schrader, Efren Serra (SAIC, Monterey)
Paul Wittmann (FNMOC)
Hendrik Tolman (NCEP)
Mike Frost (NRL, Monterey)
Collaborators
Chris Sisko, Chris Lauer, Jessica Schauer (NHC)
Andrea Schumacher, John Knaff and Mark DeMaria (CIRA)
IHC 2011Miami
Tasks
1. NHC User Requirements for ATCF (80% Complete)
2. Intensity Consensus (Complete)
3. Sea Heights Consistent with NHC Forecasts (80% Complete)
1. User Requirements for ATCFHighlights
-ATCF Requirements Lists (FY 2010 and 2011)
-60 hr forecasts
-Capability to save TWO disturbance probabilities
-Expanded seas radii capability (>995 nm)
-Other NHC/JHT/HFIP Requests
-GPCE version of wind probabilities
-“Display Only” version of Web-ATCF
-Large ensemble ingest, retention and display
-ATCF Documentation
Sixty Hour Forecast Capability
Intensity
Track
Wind Radii
Capability to save TWO disturbance probabilities
Transition disturbance to a storm
TWO disturbance entry
Disabled Menu Items
Web-ATCF “Display Only” Mode
Disabled functions throughout application. Allows no advisories, no communication with web
pages, no storm file updates. Near real-time updates on live tropical cyclones.
Large ensemble ingest, storage, display
1000 MC Wind Probability realizations. ATCF can now handle
up to 1300 aids for a single date. Still needs color for intensity.
Online Documentation
•ATCF Users Manual (300 pages)•ATCF System Administrators Guide (50 pages)•ATCF Installation Guide (10 pages)•ATCF Storm Archive Management (2 pages)•ATCF Objective Best Track Guide (5 pages)•fasDB (GRIB and Bufr Database) Guide (25 pages)•ATCF Storm Database Format (20 pages)•GUI documentation (1000 pages)•22 ATCF related journal articles
Link to documents: http://www.nrlmry.navy.mil/atcf_web/docs/ATCF-FAQ.html
2. Intensity Consensus
• Forecasts are all “early models”• Consensus is average forecast• 2006: INT3 = DSHP + GHMI + GFNI• 2007: INT4 = DSHP + GHMI + GFNI + LGEM• 2008: IVCN = DSHP+ GHMI + GFNI + LGEM + HWFI
ICON = DSHP+ LGEM + GHMI +
HWFI
* As of 2008, NHC names consensus and defines input guidance.
More info: Sampson, C. R., J. L. Franklin, J. L., J. A. Knaff and M. DeMaria, 2007:
Experiments with a simple tropical cyclone intensity consensus. Wea. And Forecasting,
23, 304-312.
Intensity Skill Relative to 2006 NHC Intensity Consensus
Atlantic 2009-2010
-10123456789
10
0 1 2 3
Forecast Day
Skill
(%
)
ICON
IVCN
IVCN+COAMPS
DSHP:+GHMI+GFNI+LGEM+COAMPS
(507) (385) (294) (234)
(DSHP+GHMI+GFNI+LGEM +COAMPS-TC) provided most skill relative to 2006
Intensity Consensus (DSHP+GHMI+GFNI). COAMPS-TC forecasts real-time at NRL
in 2010. 2009 reruns courtesy of Yi Jin (NRL). Evaluation does not contain landfall.
Intensity Skill Relative to 2006 NHC Intensity Consensus
Atlantic 2009-2010
-10123456789
10
0 1 2 3
Forecast Day
Skill
(%
)
ICON
IVCN
IVCN+COAMPS
DSHP:+GHMI+GFNI+LGEM+COAMPS
(507) (385) (294) (234)
(DSHP+GHMI+GFNI+LGEM +COAMPS-TC) provided most skill relative to 2006
Intensity Consensus (DSHP+GHMI+GFNI). COAMPS-TC forecasts real-time at NRL
in 2010. 2009 reruns courtesy of Yi Jin (NRL). Evaluation does not contain landfall.
Significant Improvement of
3-4% Over IVCN!
3. Sea Heights Consistent with Official Forecast
(OFCL/WW3)
1. Obtain GFS sfc winds
2. Cut out model vortex
3. Generate OFCL vortex
4. Insert OFCL in GFS sfc winds
5. Run WW3
6. Similar in concept to NAH WW3
(Modified) Goals for 2010:
Algorithm:
1. Produce grib files for NAWIPS
2. Use 6-h old GFS run to reduce latency
3. Run real-time at NRL
4. ATCF output for 12-ft seas radii
3. Sea Heights Consistent with Official Forecast
(OFCL/WW3)
1. Obtain GFS sfc winds
2. Cut out model vortex
3. Generate OFCL vortex
4. Insert OFCL in GFS sfc winds
5. Run WW3
6. Similar in concept to NAH WW3
(Modified) Goals for 2010:
Algorithm:
1. Produce grib files for NAWIPS
2. Use 6-h old GFS run to reduce latency
3. Run real-time at NRL
4. ATCF output for 12-ft seas radii
Buoy 41048 during Igor
0
1
2
3
4
5
6
7
8
9
1 15 29 43 57 71 85 99 113 127 141 155 169 183 197 211 225 239
Time ->
Sig
Wa
ve
Ht
(M)
Buoy 41048
WW3 Hindcast 10-min
WW3 Hincast 1-min
Buoy 41044 during Igor
0
2
4
6
8
10
12
14
1 14 27 40 53 66 79 92 105 118 131 144 157 170 183 196 209 222 235 248 261 274 287 300
Time ->
Sig
Wav
e H
t (M
)
Buoy 41044
WW3 Hindcast 10-min
WW3 Hindcast 1-min
Buoy 41047 During Earl
0
2
4
6
8
10
12
1 11 21 31 41 51 61 71 81 91 101 111 121 131 141 151 161 171 181 191 201 211
Time --->
Sig
Wav
e H
t (M
)
OFCL/WW3 10-min
OFCL/WW3 1-min
OFCL/WW3
OFCL/WW3 Hindcasts vs Buoys
TAFB Eval: OFCL/WW3 sea heights 5-6ft low (ouch!)
Buoy 41046 During Earl
0
2
4
6
8
10
12
14
16
18
20
1 12 23 34 45 56 67 78 89 100 111 122 133 144 155 166 177 188 199 210
Time --->
Sig
Wav
e H
t (M
)
Buoy 41046
OFCL/WW3 10-min
OFCL/WW3 1-min
OFCL/WW3 Radii of 12-ft Seas Evaluation Using TAFB Analysis as Ground Truth
Improved biases
Need to revisit wind radii assignment beyond 72 h as some
expansion of wind radii needed (use DRCL?). Also possibly
removing too much of background winds during vortex insertion.
3. Sea Heights Consistent with Official Forecast
(OFCL/WW3)
Remaining Tasks for 2011:
1. Implement in NHC environment (underway)
2. Documentation (underway)
3. Real-time runs in NHC environment in 2011
4. Experiments with modified algorithms (if time permits)
Progress Summary
1. NHC User Requirements for ATCF (80% complete)
2. Intensity Consensus Review and Update (complete)
3. Sea Heights Consistent with NHC Forecasts (80% complete)
EXPERIMENTAL TC-COR GUIDANCE
SITE TC-COR
Agrihan 2 Alamagan 2 Anatahan 2 Pagan 2 Saipan 3 Tinian 4
•Based on Watches/Warnings and cumulative wind probabilities in the Atlantic and Gulf of Mexico (CIRA)•Strategic objective guidance for onset of 50-kt winds at military installations•Does not include local effects or base sensitivities
TC-COR Threshold Probabilities Forecast Lead 4 5% 72 H 3 6% 48 H 2 8% 24 H 1 12% 12 H
(NRL, CIRA, NOAA/NESDIS)
EXPERIMENTAL TC-COR GUIDANCE
SITE TC-COR
Agrihan 2 Alamagan 2 Anatahan 2 Pagan 2 Saipan 3 Tinian 4
•Based Watches/Warnings and cumulative wind probabilities in the Atlantic and Gulf of Mexico (CIRA)•Strategic objective guidance for onset of 50-kt winds at military installations•Does not include local effects or base sensitivities
TC-COR Threshold Probabilities Forecast Lead 4 5% 72 H 3 6% 48 H 2 8% 24 H 1 12% 12 H
(NRL, CIRA, NOAA/NESDIS)
Why so low?
Why are the TC-COR guidance thresholds so low?
•Guidance should step through conditions sequentially•Times should correspond to those in operations, if possible•Shouldn’t miss a wind event
Objective TC-COR Settings for 26W 2004 at Yokosuka
Current Thresholds Double Current Thresholds Quadruple Current Thresholds(Maximum Threat Scores)
4 (-70 hours) 4 Missed 4 Missed
3 (-34 hours) 3 (-34 hours) 3 Missed
2 (-16 hours) 2 Missed 2 Missed
1 (-10 hours) 1 (-10 hours) 1 (-10 hours)
55 kt (Oct 9 1634) 55 kt (Oct 9 1634) 55 kt (Oct 9 1634)
Why are the TC-COR guidance thresholds so low?
•Guidance steps through conditions sequentially•Times are reasonable•This guidance was *not* available to forecasters in real-time
Objective TC-COR Settings for 26W 2004 at Yokosuka
Current Thresholds Double Current Thresholds Quadruple Current Thresholds(Maximum Threat Scores)
4 (-70 hours) 4 Missed 4 Missed
3 (-34 hours) 3 (-34 hours) 3 Missed
2 (-16 hours) 2 Missed 2 Missed
1 (-10 hours) 1 (-10 hours) 1 (-10 hours)
55 kt (Oct 9 1634) 55 kt (Oct 9 1634) 55 kt (Oct 9 1634)
TC-COR 1 EVALUATION
•82 cases •10 Navy and Air Force bases •WestPac, Atlantic•1996-2009
TC-COR 1 Forecast vs Base Setting (73 Cases)
Observed YesObserved No
Forecast Yes 10 15
Forecast No 0 57
Observed YesObserved No
Forecast Yes 20 3
Forecast No 9 41
TC-COR 1 Forecast vs Observed Wind Near Site (82 Cases)
Misses
False Alarms
Threat Score=.625
Threat Score=.4