# Presentation: 388092

## WFO Applications of TAMDAR

- Many WFOs have begun to use TAMDAR in their public, aviation and marine forecasts.
- Many other applications are yet to be realized, such as fire weather, HAZMAT support, and convective warnings.

## FSL Web Access

- Total soundings accessed by NWS Central Region offices are now more than double before the GLFE began.
- Sounding requests from TAMDAR airports rose from 279 in December 2004 to more than 700 in February and March 2005

## Area Forecast Discussions

- NWS meteorologists have mentioned the use of TAMDAR in their area forecast discussions about fifty times each month.

## TAMDAR Data Use

- TAMDAR has been used in forecasting
- Fog formation
- Model comparison and verification
- Lake effect snow
- Precipitation type – Ice Storm
- Precipitation type - Snowstorm
- Use in Local Models

## Fog Formation

- AREA FORECAST DISCUSSION
- NWS GREEN BAY WI
- 345 AM CST MON MAR 21 2005

- .SHORT TERM...TODAY THROUGH TUESDAY. RELATIVELY QUIET
- TONIGHT COMPARED TO THE LAST FEW DAYS. NORTHEAST LOW LEVEL
- FLOW CONTINUES TO PRODUCE SOME CLOUDINESS OVER THE
- NORTHEAST HALF OF THE FORECAST AREA. SOME LAKE EFFECT
- SNOW FLURRIES SEEN OVER THE LAKE ON RADAR SHOULD STAY THERE.
- _DONT THINK FOG WILL DEVELOP BEFORE SUNRISE DUE TO GRADIENT_
- _WIND AND DRY T__**AMDAR**__ SOUNDINGS FROM LATE EVENING FLIGHTS_
- _INTO CENTRAL WISCONSIN AIRPORT._

## Fog Formation

- AREA FORECAST DISCUSSIONNWS NORTHERN INDIANAAFDIWX 645 PM EST SAT MAR 26 2005
- .AVIATION... FOG/LOW CLOUDS A CONCERN FOR AVIATION TONIGHT AS
-  DEWPOINT DEPRESSIONS 5-8DEG WITH LIGHT WINDS AS SUNSET
- APPROACHES. HWVR, FAIRLY WIDESPREAD LOW/MID CLOUDS
- LINGERING ACROSS THE AREA, AND HIGH CLOUDS SPREADING NE
- TOWARD THE MDWST SHOULD LIMIT RADIATIONAL COOLING TONIGHT.
- ALSO, _T__**AMDAR**__ SOUNDINGS FROM SBN/FWA THIS EVE SHOWING DWPTS _
- _DECREASING WITH HEIGHT IN LOWEST 50MB AGL_

## Model Comparison & Verification

- AREA FORECAST DISCUSSIONNWS GRAND RAPIDS MIAFDGRR 308 AM EST THU MAR 17 2005
-      THE SHORT RANGE MODELS ARE SIMILAR THIS MORNING AND BASICALLY HAVE THE NORTHWEST US SHORT WAVE INDUCING A SFC LOW IN THE PLAINS TODAY AND THEN THAT LOW MOVES EAST THROUGH THE CWA BY LATE SATURDAY. _GFS AND ETA MODEL SOUNDINGS LINE UP VERY NICELY WITH CURRRENT T__**AMDAR**__ SOUNDINGS OVER THE SOUTHERN GREAT LAKES AND SHOW A REMARKABLY SIMILAR PROFILE._

## Lake Effect Snow

- AREA FORECAST DISCUSSIONNWS MARQUETTE MIAFDMQT 1032 AM EST SUN MAR 13 2005
- .DISCUSSION... MAIN UPDATE CONCERN IS LAKE EFFECT.
- A POLAR VORTEX WAS LOCATED OVER FAR NW ONTARIO IN THE
- TROUGH...WITH A SHRTWV LOCATED NEAR PICKLE LAKE ONTARIO.
- HEIGHTS CONTINUE TO RISE OVER UPPER MICHIGAN AHEAD OF THIS
- SHRTWV...NOW APPROXIMATELY AT 525 DAM (NEAR 10 DAM INCREASE
- SINCE 00Z). THESE RISING HEIGHTS HAVE ALSO YIELDED RISING 850MB
- TEMPERATURES WITH READINGS AROUND -15C OVER WESTERN LAKE
- SUPERIOR AND -18C OVER THE EASTERN PORTION. _LAKE EFFECT_
- _CONTINUES DUE TO THE INSTABILITY...BUT DRY AIR AS SEEN ON A_
- _12Z T__**AMDAR**__ SOUNDING AT CMX AND THE 12Z GRB SOUNDING HAS_
- _KEPT THE LAKE EFFECT LIGHT.  _

## Precipitation type – Ice Storm

- Forum posting from Andrew Just at NWS Marquette
- Yesterday morning (December 30th) at the Marquette NWS office, _we constantly_
- _looked at the latest TAMDAR soundings_ to get a measure of the amount of both
- dry air over the Western Great Lakes Region and how warm the air was aloft. The
- reason for this was the concern for a period of freezing rain across Upper Michigan,
- and whether some of the precipitation would start off as snow or sleet due to
- evaporative cooling. Surface observations told us when the freezing rain would
- transition over to rain, however the frequent soundings gave us more of an idea
- how long the freezing rain would last. _Because the soundings showed potential for_
- _a couple of hours of freezing rain with little in the way of snow or sleet, we upgraded_
- _the winter weather advisories to ice storm warnings._ These warnings would
- eventually verify during the afternoon, with reports of anywhere from 0.25 to 0.5 inch
- of ice along with plenty of accidents on the roads.

## Precipitation type - Snowstorm

- Comments received from Dan Baumgardt, Science Officer, NWS La Crosse
- On December 5, 2004, there was some question on the precipitation type during the
- night. The models were indicating that the warm air would advance northward into
- the region...but the TAMDAR flights that evening showed that the cold air was
- holding.  _As a result, the snow changing to all rain forecast was changed to all snow _
- _and accumulations were added to the forecast.  The area ended up seeing all snow _
- _during this event; thus, the TAMDAR data proved to be a very valuable data during_
- _this event. _

## Use in Local Model

- AREA FORECAST DISCUSSION...UPDATENWS CLEVELAND OHIOAFDCLE 940 PM EST WED MAR 2 2005
- PREV UPDATE... AM SOMEWHAT CONCERNED ABOUT THE CONTINUED
- MOISTURE OVR ONTARIO ROTATING INTO THE AREA. ALTHOUGH THE
- FORECAST AREA IS NOW GENERALLY UNDER WEAK NVA WITH THE
- VORT NOW TO THE SE OF THE AREA...AM NOT CONFIDENT THAT THE
- MOISTURE WILL EXIT/DISSIPATE AS FAST AS THE MDLS SUGGEST. THE
- 18Z NAM INSISTS ON STRONG LOW LVL CVRG AND UPWARD MOTION
- ACROSS NW PA. COMBINED WITH THE LK HURON FETCH AND STRONGLY
- CYCLONIC FLOW CONTINUING INTO THE EARLY MORNING THINK THAT
- LCLY HVY SNOW WILL CONTINUE THRU MIDNIGHT. _DATA FROM T__**AMDAR**_
- _FLIGHT INTO ERI AT 23Z ALSO SHOWS INVERSION STILL ABOVE 6000 FT_
- _SO THERE IS STILL PLENTY OF LOW LVL INSTABILITY. NWS MQT WRF _
- _RUN FROM 18Z USING THE T__**AMDAR**__ DATA CONTINUES TO SHOW _
- _SIGNIFICANT PCPN FOR NW PA OVERNIGHT.  _

## Sounding Comparisons

- TAMDAR was compared with NWS radiosondes at 1100 UTC and 2300 UTC Saturday, 4/9/05
- Comparisons at Minneapolis and International Falls were favorable, with little questionable data seen.

## International Falls, Minnesota

- 2300 UTC April 9, 2005
- Temperature differences at 925, 850, and 700mb were 0.8C, 1.1C, and 0.4C
- Dewpoint differences were 1.0C, 0.8C, and 0C
- Wind speed and direction differences were negligable

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## Minneapolis, Minnesota

- 1100 UTC April 9, 2005
- Radiosonde compared to two TAMDAR soundings from short duration flights.
- Average temperature differences at 950, 925, and 850 mb were  0.3C, 0.8C, and 0.2C
- Average dewpoint differences were 0.7C, 1.1C, and 6.5C (sharp gradient at 850mb)
- Wind direction differences averaged 10 to 20 degrees, speeds differed by up to 19 knots in strong, turbulent low level jet

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## Need to Address

- Update Mesaba Flight Schedule
- Inform WFOs of change to GLFE duration
- Get TAMDAR used for Severe Weather support by WFOs, CWSUs, AWC, SPC and airline meteorology units – believe this to be extremely important for success

## Mesaba Schedule

- Current Mesaba schedule on GLFE web page is from December 2004
- Some flight times and routes have been changed
- This should be updated immediately

## Inform WFOs of duration of GLFE

- Will need to inform users to date change of GLFE. This may affect participation (should improve it), local model runs, and survey times
- Other users such as the media and universities should also be informed

## Severe Weather Applications

- TAMDAR should prove to be even more valuable during the convective season
- Reduction of data due to icing should be  greatly reduced
- Events such as squall lines and mesoscale convective complexes are often poorly handed by models and forecasters due to lack of data. TAMDAR should be of great value