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Applications of Aircraft Weather Data

American Meteorological Society Short CourseSan Antonio, Texas January 14, 2007

Rich Mamrosh – NOAA NWS Green Bay, Wisconsin

Applications in Field Forecast Offices

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Applications in Field Forecast Offices

• National Weather Service – Warning and Forecast Offices– Center Weather Service Units– Storm Prediction Center

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NWS Forecast Office Applications

• Data Comparison (Radiosonde, Radar, Profilers)

• Marine (Wind and Wave Forecasts)

• Fire Weather (Haines Index, Mixing Heights)

• High Wind Events (Santa Ana, Front Range, Synoptic)

• Aviation (Ceiling, Visibility, LLWS)

• Winter (Precipitation Type, Lake Effect Snow)

• Convective Storms (Watch and Warning Decisions)

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Data Comparison

Wind Profilers

Commercial aircraft

GOES and POES Satellites

Wind Estimates from Doppler Radar

RadiosondesNumerical models

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Data Comparison

• The NWS in La Crosse, Wisconsin used TAMDAR to verify what looked to be erroneous radiosonde data.

• The dewpoint from the Minneapolis, Minnesota radiosonde seemed way too low.

• TAMDAR data showed that the radiosonde information was indeed correct. This was very important in determining what precipitation type was likely later that day.

Radiosondes

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Data Comparison

AREA FORECAST DISCUSSIONNWS LA CROSSE WIAFDARX 401 AM CST MON NOV 1 2004

.SHORT TERM... THE NOVEMBER 1ST 00Z 850 MB DEW POINT OF -36C AT CHANHASSEN LOOKED INITIALLY SUSPICIOUS WHEN LOOKING AT TRAJECTORIES. HOWEVER...A MESABA AIRCRAFT WITH THE NEW TAMDAR SENSOR AT 04Z HAD A DEW POINT OF -32C IN THE CHANHASSEN AREA. THE ACCURACY OF THIS DEW POINT IS RATHER CRITICAL BECAUSE IT AFFECTS THE INITIAL ONSET OF PRECIPITATION…

Radiosondes

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Data ComparisonModel Forecasts

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Data ComparisonModel Forecasts

• Senior duty meteorologists at NCEP often use AMDAR flight level data to determine the validity of radiosonde winds and temperatures. Meteorologists in WFOs and CWSUs compare AMDAR to model initial analyses and forecasts.

• The Lousiville, Kentucky NWS used AMDAR on May 17, 2005 to validate their suspicions that the NAM model dewpoints in the low levels were erroneous.

• The boundary layer moisture was important in the fog forecast that night.

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Data Comparison

AREA FORECAST DISCUSSIONNWS LOUISVILLE KYAFDLMK 940 PM EDT TUE MAY 17 2005

.UPDATE... HAVE NOTED VERY HIGH DEW POINT ERRORS IN THE RECENT RUNS OF THE ETA (NAM) MODEL. LOOKS AS THOUGH THE NAM HAD WAY UNDER-FORECAST THE MAGNITUDE OF THE DRY POCKET WITHIN THE DAYTIME BOUNDARY LAYER STRETCHING FROM THE OHIO VALLEY INTO THE MID-SOUTH THIS EVENING. AN ACARS DESCENT SOUNDING INTO EVANSVILLE AROUND 1Z SHOWED 950MB DEWPOINTS OF +4C...THE ETA HAD FORECAST +10 WITH THE GFS MUCH CLOSER AT +5C. WITH THAT SAID...OUR DEW POINT FORECAST WAS ON TARGET.

Model Forecasts

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Marine Forecasting

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Marine Forecasting

• A dense network of wind and temperature soundings are important to the production of accurate wind and waves forecasts.

• Temperature profiles are important to determine stability (which affects mixing down of stronger winds aloft).

• Wind profiles are needed to determine directional and vertical shear (which also affect transport of stronger winds aloft).

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Marine Forecasting

A dense network of radiosondes is not available near the oceans and Great Lakes.

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Marine Forecasting

• AMDAR observations have provided meteorologists with valuable supplemental data near the oceans and Great Lakes.

• Forecasters have used AMDAR to issue, continue and discontinue Small Craft Advisories, Gale Warnings and Storm Warnings.

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Marine Forecasting

• The NWS in Grand Rapids, Michigan used AMDAR data in deciding to continue a Gale Warning for the nearshore waters of eastern Lake Michigan on November 6, 2005.

• TAMDAR soundings from Kalamazoo, Michigan showed that there still were winds at nearly 50 knots in the lowest 3,000’ of the atmosphere.

• In addition, the air was unstable, and the winds had little directional shear – both favorable for the transfer of strong winds to the surface.

Gale Warning

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Marine Forecasting

GALE WARNING: A warning of sustained surface winds, or frequent gusts, in the range of 34 knots (39 mph) to 47 knots (54 mph) inclusive, either predicted or occurring, and not directly associated with a tropical cyclone.

Map of NWS Grand Rapids forecast area. Nearshore marine area is in purple.

Gale Warning

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Marine Forecasting

AMDAR data in Great Lakes region from 1400 to 1659 UTC on November 6, 2005

Gale Warning

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Marine Forecasting

TAMDARSoundingFrom KalamazooShowingWest windsAt 46 knots About2,200’ AGL.

Gale Warning

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Marine Forecasting

AREA FORECAST DISCUSSIONNWS GRAND RAPIDS MIAFDGRR 1032 AM EST SUN NOV 6 2005

5 MINUTE WIND DATA AT THE GLERL COAST SITES SHOWS THEWINDS HAVE PEAKED AT MKG...LWA AND MICHIGAN CITY IN THEPAST HOUR NEAR 45 KNOTS. THE TREND IS NOW DOWN SLOWLYON THE WIND SPEED. TAMDAR DATA STILL SHOWS WINDS UNDER 5000 FT OF JUST UNDER 50 KNOTS OVER THE WESTERN CWA AT 10 AM. AS A RESULT OF ALL OF THAT I PLAN ON LEAVING THE GALEWARNING AND THE WIND ADVISORY AS IS INTO THE MID AFTERNOON.

Gale Warning

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Marine Forecasting

• AMDAR can provide the information to determine the likelihood of lake and sea breeze formation.

• Lake and sea breezes are hindered by an offshore gradient wind, and enhanced by an onshore wind. Stability also plays a role.

Lake and Sea Breezes

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Marine Forecasting

• Meteorologists at the NWS in Cleveland used AMDAR data on April 16, 2005 to forecast the formation and inland penetration of a lake breeze from Lake Erie.

• AMDAR soundings showed that there were significant south (offshore) winds that would slow the formation of the lake breeze, and limit it’s inland movement.

• In addition to it’s importance for mariners, this wind forecast also affects the large hub airport at Cleveland.

Lake and Sea Breezes

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Marine Forecasting – Lake and Sea Breezes

AMDAR sounding from 1244 UTC in the vicinity of Cleveland

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Marine Forecasting – Lake and Sea Breeze

AREA FORECAST DISCUSSIONNWS CLEVELAND OHIO1159 AM EDT SAT APR 16 2005

.UPDATED…SOUTH WINDS WERE INCREASING AND TEMPERATURES WERE RISING WITH FULL SUNSHINE. HIGHS SHOULD RANGE FROM 65 TO 70 DEGREES. THE LAKE BREEZE, IF IT DOES DEVELOP, SHOULD BE RIGHT ALONG THE LAKESHORE FROM NEAR CLEVELAND THROUGH ERIE. AMDAR DATA NEAR CLEVELAND WAS INDCATING THE WINDS FROM SOUTH AROUND 25 KNOTS AT 2,000 FEET.

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Fire Weather

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Fire Weather

• AMDAR data are becoming increasingly utilized by fire weather forecasters, as coverage expands across the U.S.

• Useful fire weather forecasts are dependent on accurate observations and/or model forecasts of mixing layer heights, Haines indices, and surface relative humidity.

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Fire Weather

• Smoke from prescribed burns and wildfires can cause serious problems for those with respiratory problems. It also can also cause accidents by reducing visibilities on highways.

• The NWS produces a Smoke Dispersion index based mostly on model forecast soundings. These forecasts are used by fire weather agencies to determine whether prescribed burns should be allowed, and if wildfires might produce hazardous smoke conditions.

Smoke Dispersion

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Fire Weather

• The Miami NWS used AMDAR to update smoke dispersion forecasts on May 2, 2005.

• ACARS soundings showed very light winds (3-10 kts) in the mixed layer, which inhibits smoke dispersion.

Smoke Dispersion

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Fire Weather

ACARS soundingFrom 1411 UTC On May 2, 2005In the vicinity ofMiami, FloridaShows very light Winds (< 10 kts)in the mixed Layer.

Smoke Dispersion

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Fire Weather

AREA FORECAST DISCUSSIONNWS MIAMI FL1030 AM EDT MON MAY 2 2005

.FIRE...WILL AMEND GRIDS AND FWF. WINDS IN MIXED LAYER ARE FAIRLY LIGHT, WHICH IS CONFIRMED BY ACARS DATA. THIS WILL RESULT IN ADJUSTMENTS TO TODAY’S DISPERSION INDICES.

Smoke Dispersion

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Fire Weather

• The utility of AMDAR in fire weather forecasting fostered the development of locally driven efforts.

• An experiment called HI-RISE (Hazardous Incident − Rapid In-flight Support Effort) was conducted in the spring of 2005 by the following participants – National Weather Service– Texas Forest Service– USDA Agricultural Station– Aventech Research Inc.

AMDAR inspired systems

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Fire Weather

Air Tractor AT-402B aircraft used in HI-RISE

Data flow in HI-RISE experiment*

AIMMS-20 instrumentation

HI-RISE involved the installation of meteorological instruments on a small firesurveillance aircraft, and downlinking the data in real time to meteorologists.

D

AMDAR inspired systems

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Fire WeatherNon-commercial aircraft such as these can fly REALLY close to fires andmeasure meteorological parameters vital in forecasting fire behavior

Air Tractor AT-402B aircraft flying over Texas Forest Service ground crew during HI-RISE experiment

AMDAR inspired systems

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Fire Weather

Example of aircraft sounding from HI-RISE fire weather experiment.Notice highly detailed temperature, moisture and wind data.

AMDAR inspired systems

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Fire Weather

• This proof of concept experiment provided valuable real time data to fire weather forecasters at controlled burns in central Texas.

• All of the participants agreed that this concept should be developed further for fire weather and other applications, including HAZMAT support.

HI-RISE Team from NWS, USDA, Texas Forest Service and AVENTEC

AMDAR inspired systems

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High Winds

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High Winds

• Non - convective high wind events occur over the entire country.

• Meteorologists largely rely on model forecasts to issue high wind watches, and a combination of observations and model data to issue warnings.

• The lack of real time upper air data can make warning decisions difficult.

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High Winds

• Downslope high wind events occur with some regularity in the Rocky Mountain region.

• Santa Anna winds in California and strong winds along the front range in Colorado are two well known phenomena that are forecast challenges.

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High Winds

Schematic of Santa Ana winds in southern California

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High Winds

• A Santa Ana wind event occurred the night of December 22-23, 2006 in southern California.

• Meteorologists at the NWS in San Diego monitored AMDAR soundings during the early morning hours, and decided to upgrade a wind advisory to a high wind warning based on AMDAR soundings.

Santa Ana

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High Winds

AREA FORECAST DISCUSSIONNWS SAN DIEGO CA1120 PM PST FRI DEC 22 2006

.DISCUSSION... UPDATE TO UPGRADE THE WIND ADVISORY FOR THE INLAND EMPIRE AND THE SANTA ANA MOUNTAINS AND FOOTHILLS TO A HIGH WIND WARNING THROUGH EARLY AFTERNOON SATURDAY. RECENT ACARS SOUNDINGS FROM ONTARIO SHOW A VERY IMPRESSIVE SUBSIDENCE INVERSION NEAR 700 MB FAVORABLE FOR MOUNTAIN WAVE DEVELOPMENT AS WELL AS AN OVERALL STRONG WIND FIELD BELOW 700 MB WITH WINDS UP TO 50 KNOTS OR SO. WINDS IN THE WINDIER LOCATIONS...BELOW THE CAJON PASS AND NEAR FREMONT CANYON HAVE GUSTED TO AROUND 60 MPH IN THE PAST HOUR.

Santa Ana

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High Winds

AMDAR sounding at 0411 UTC December 23, 2006 from Ontario,California showing mountain top inversion and strong wind field.

Santa Ana

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High Winds

• A High Wind event driven by an intense cyclone occurred in the Northeast on November 13, 2003.

• The NWS in Upton (Long Island), New York used AMDAR data to monitor winds aloft in real time, and made warning decisions based on these data.

• The upstream data at the New York area airports was especially valuable.

New York City

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High Winds

Surface weather map from November 13, 2003 shows strong cyclone over southern Quebec

New York City

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High Winds• AREA FORECAST DISCUSSION• NATIONAL WEATHER SERVICE UPTON NY• 1000 AM EST THU NOV 13 2003 .

• DISCUSSION... .UPDATE...SEVERAL REPORTS OF DOWNED TREES/DAMAGE AND WINDS AS HIGH AS 52 KT AT AMBROSE LIGHT. HIGHEST LAND BASED WIND IS 48 KT AT LGA. EXAMINATION OF 12Z ACARS WINDS REPORTS SHOWS THAT 09Z RUC WINDS ARE TOO LOW AND THAT EVEN 06Z ETA WINDS ARE FEW KNOTS BELOW OBSERVED. AS COLD ADVECTION WORKS IN THIS AFTERNOON...HIGHER LEVEL WINDS WILL WORK DOWN TO SURFACE. USING A 90% RULE OF WINDS ALOFT...RESULTS IN PEAK SURFACE OF 60 KT OR 70 MPH. WILL HEADLINE...WIND GUSTS TO NEAR HURRICANE FORCE.

New York City

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High Winds12UTC soundingFrom BrookhavenNew York shows60+ knot windsWithin 2,000’ AGL.

New York City

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High Winds1243 UTC AMDAR soundingfrom JFK airportshows 51 knotwinds around 2400’ AGL.

New York City

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High Winds

1433 UTC AMDAR soundingfrom Newark, NJshows 63 knotwinds around 3000’ AGL andan almost dry,adiabatic lapserate.

New York City

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High Winds

AREA FORECAST DISCUSSIONNWS GRAND FORKS ND340 AM CST SUN DEC 17 2006

.SHORT TERM (SUN-TUE)...AMDAR SOUNDINGS AT 05Z FOR DVL/JMS SHOWED THAT MORE COLD ADVECTION HAD OCCURRED AT 850 MB THAN MODELS ANTICIPATED WHILE LOW LEVEL WINDS WERE STRONGER TOO. THE COLDER CONDITIONS HAVE KEPT THE BOUNDARY LAYER MORE MIXED AND WINDS ARE ABLE TO MIX THROUGH A BIT EASIER. JMS SHOWED 70 KNOTS AT 801 MB (JUST ABOVE THE INVERSION) AND DVL SHOWED 50 AT 911 MB. THESE WERE 10 TO 25 KNOTS HIGHER THAN MODEL SOUNDINGS.

North Dakota

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High Winds TAMDAR sounding from0509 UTC inthe vicinity ofJamestown,North Dakotaon December17, 2006 shows70 knot windsat 801 mb.

North Dakota

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Aviation Forecasting

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Aviation Forecasting

• Meteorologists at the NWS San Diego office are one of the biggest users of AMDAR data in the United States. The scarcity of upstream data, varied terrain, and a maritime influence make the availability of frequent upper air data very useful.

• The data are especially useful to monitor the depth of the marine layer, upon which the formation and inland penetration of low clouds and fog are dependant upon.

Ceiling and Visibility

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Aviation ForecastingCeiling and Visibility

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Aviation Forecasting

The San Diego Forecast Office is responsible for the TAFs for Ontario (ONT), John Wayne (SNA), San Diego (SNA), as well as Palm Springs, Thermal, and Carlsbad (Not shown)

Ceiling and Visibility

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Aviation ForecastsCeiling and Visibility

The TAF for Ontario issued at 2325 UTC on April 30, 2001 mentioned that visibilities might fall to 2 miles late at night, and that skies would be clear. It was thought that the depth of the inversion would be insufficient to climb the range of hills, and reach the inland valley area.

TAFONTKONT 302327Z 010024 26015KT 5SM HZ SCT250

FM0400 25005KT 5SM HZ SKC

FM0600 VRB03KT 5SM BR

SKC

FM1300 VRB03KT 2SM BR HZ

SKC

FM1900 26009KT 4SM HZ

SKC

FM2200 26015KT P6SM SKC=

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Aviation Forecasts

ACARS from Long Beach, California at 0232 UTC on May 1, 2001 shows the base of a temperature inversion around 1,000’

Ceiling and Visibility

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Aviation ForecastsCeiling and Visibility

ACARS from San Diego, California at 0233 UTC on May 1, 2001 shows the base of a temperature inversion around 1,200’.

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Aviation ForecastsCeiling and Visibility

ACARS WVSS from Ontario, California at 0201 UTC on May 1, 2001 shows the base of a temperature inversion around 1,900’.

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Aviation Forecasts

Ceiling and Visibility

TAFONTKONT 010525Z 010606 VRB03KT 5SM BR SKC

FM1200 VRB03KT 2SM BR OVC008 TEMPO 1215 1SM BR OVC005

FM1600 VRB03KT 3SM BR HZ SKC FM2000 26012KT 5SM HZ SKC FM0500 VRB03KT 4SM BR OVC010=

The meteorologist noticed that soundings from the evening hours showed that the marine layer was about 1,000 to 1,200 feet along the coast, and 1,900 feet MSL at Ontario. This suggested that the damp, maritime air had already reached the interior valley, and that low clouds and fog were indeed possible. This information was used to issue the 06UTC TAF, forecasting IFR ceilings of 5 hundred feet and visibilities around one mile were expected overnight.

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Aviation Forecasts

AREA FORECAST DISCUSSION...UPDATEDNWS FORT WORTH TX1055 AM CDT TUE MAY 4 2004

.AVIATION... 604 AM. VFR...LLWS THRU 14Z THEN NO CONCERNS.SW WINDS AT 1-2 KFT HAVE SET UP A STRONG INVERSION...AND A LLJ OF ARND 23035KT PER ACARS SOUNDINGS/VWP. WITH LT 10 KTS AT THE SFC...I WILL MENTION LLWS THRU 14Z. WITH QUICKLY WARMING TEMPERATURES UNDER PLENTY OF SUN...ANY LLWS SHLD BE GONE BY MID MORNING WITH GUSTY S/SW WINDS. SLY WINDS 5-15 KTS TO PREVAIL TONIGHT. 30/SS &&

Low Level Wind Shear

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Winter Weather

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Winter Weather

• Precipitation type remains one of the main challenges of winter weather forecasting.

• Accurate forecasts require a detailed knowledge of the temperature and humidity structure of the atmosphere.

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Winter Weather

• Meteorologists at the NWS offices in Warsaw, Indiana used TAMDAR during the evening of December 25, 2006 to determine that cloud microphysics were not suitable for heavy snowfall.

• TAMDAR soundings into Fort Wayne showed that temperatures were too warm for significant ice crystal growth.

• They updated their forecast, to reduce (in half) the snow accumulation amounts.

Northern Indiana

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Winter Weather

AREA FORECAST DISCUSSIONNWS NORTHERN INDIANA935 PM EST MON DEC 25 2006

.UPDATE... 2355 UTC TAMDAR DESCENT SNDG INTO KFWA CONFIRMS TEMPS THROUGH 700MB TO BE BARELY SUFFICIENT FOR NUCLEATION WITH TEMPS AOA M7C. OUTSIDE OF RELATIVELY WEAK AND POORLY DEFINED TRANSITORY BANDING THAT BRINGS A MIX TO BRIEF BURST OF 2-3SM -SN CHANGEOVER...THERE CONTINUES TO BE NO ACCUMS GIVEN 2 INCH SOIL TEMP OF 38F AND MAX SUBCLOUD T OF 2-4C AND WET GROUND MELTING SNOW AS SOON AS IT FALLS. MOST OF CWA PLAGUED WITH SATURATION BENEATH PRIME NUCLEATION HEIGHT AS SUCH HAVE UPDATED AND BASICALLY HALVED ACCUMS OUTSIDE OF FAR W/NW WITH MENTION OF TRACE MIXED EVENT

Northern Indiana

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Winter Weather

TAMDARsounding from0027 UTC onDecember 25,2006 shows adeep, moistlayer that isgenerally toowarm for icecrystal Formation.

Northern Indiana

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Convective Storms

Supercell thunderstorm near Joplin, Missouri

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Convective Storms

• AMDAR data has been shown to be very effective in the issuance of convective watches and warnings.

• Real time data has been very valuable in determining the presence of capping inversions, wind shear, low level moisture, etc.

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Convective Storms – Warning Decisions

• The NWS in La Crosse, Wisconsin used TAMDAR in deciding NOT to issue a tornado warning – despite a tornado signature on radar.

• This late season event in October, 2006 shows the utility of AMDAR in the proper depiction of the near-storm environment, which is vital to accurate convective warnings.

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Convective Storms – Warning Decisions

Surface warm front expected to be the focus for surface based convection during the afternoon hours. Given the high cape and high shear environment the area was in a Moderate Risk for severe weather with a heightened threat for tornadoes.

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2000 UTC SPC Day 1 Outlook

• Moderate Risk highlighted area of high shear, instability and moisture pooling along a frontal boundary.

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Convective Storms – Warning Decisions•MCD indicated storms expected to develop in the outlook area with increasing CAPE just north of a warm front.

•Although a capping inversion was in place this was expected to weaken during the afternoon hours.

•Strong deep layer shear expected to promote supercells with possible tornadoes.

•Tornado Watch was issued at 2035 UTC.

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Convective Storms – Warning Decisions

Map of NWS La Crosse, Wisconsin forecast area (shaded)

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Convective Storms – Warning Decisions

Large Supercell over the Minneapolis forecast area.

Multiple tornado warnings were issued for the storm as is moves into western Wisconsin.

•Warning decision needs to be made around 0100 UTC for ARX

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Convective Storms – Warning Decisions

MSP soundings shows a stronger CAP to the south but a strong and persistent cap in all directions.

EAU sounding indicated very dry air at the surface and a strong CAP.

LSE soundings show a strengthening CAP and dry air at the surface.

A subsequent MSP sounding showed a stronger CAP and deeper stable layer than the RUC.

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Convective Storms – Warning Decisions

Aircraft soundings gave forecasters confidence in issuing Severe Thunderstorm Warnings and holding off on Tornado Warnings.

The Supercell subsequently weakened as it moved through the La Crosseforecast atea.

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Summary

• The use of AMDAR has increased in WFOs, CWSUs, and NCEP centers in the past decade.

• Applications of AMDAR have been found for almost all weather phenomena.

• Need dense coverage of observations that can be provided by regional airlines.

• Need more water vapor soundings.

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Acknowledgements

• Gary Austin - NWS Green Bay MIC• Pete Browning - NWS Central Region SSD• Dave Helms - NWS Office of Science and Technology