WFO Applications of TAMDARWFO 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 AccessFSL 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 DiscussionsArea Forecast Discussions

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

TAMDAR Data UseTAMDAR 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 FormationFog FormationAREA 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 LEVELFLOW CONTINUES TO PRODUCE SOME CLOUDINESS OVER THENORTHEAST HALF OF THE FORECAST AREA. SOME LAKE EFFECTSNOW FLURRIES SEEN OVER THE LAKE ON RADAR SHOULD STAY THERE.DONT THINK FOG WILL DEVELOP BEFORE SUNRISE DUE TO GRADIENTWIND AND DRY TAMDAR SOUNDINGS FROM LATE EVENING FLIGHTSINTO CENTRAL WISCONSIN AIRPORT.

Fog FormationFog 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 SUNSETAPPROACHES. HWVR, FAIRLY WIDESPREAD LOW/MID CLOUDSLINGERING ACROSS THE AREA, AND HIGH CLOUDS SPREADING NE TOWARD THE MDWST SHOULD LIMIT RADIATIONAL COOLING TONIGHT. ALSO, TAMDAR SOUNDINGS FROM SBN/FWA THIS EVE SHOWING DWPTS DECREASING WITH HEIGHT IN LOWEST 50MB AGL

Model Comparison & VerificationModel 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 TAMDAR SOUNDINGS OVER THE SOUTHERN GREAT LAKES AND SHOW A REMARKABLY SIMILAR PROFILE.

Lake Effect SnowLake 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 THISSHRTWV...NOW APPROXIMATELY AT 525 DAM (NEAR 10 DAM INCREASESINCE 00Z). THESE RISING HEIGHTS HAVE ALSO YIELDED RISING 850MBTEMPERATURES WITH READINGS AROUND -15C OVER WESTERN LAKESUPERIOR AND -18C OVER THE EASTERN PORTION. LAKE EFFECTCONTINUES DUE TO THE INSTABILITY...BUT DRY AIR AS SEEN ON A12Z TAMDAR SOUNDING AT CMX AND THE 12Z GRB SOUNDING HASKEPT THE LAKE EFFECT LIGHT.

Precipitation type – Ice StormPrecipitation type – Ice Storm

Forum posting from Andrew Just at NWS Marquette

Yesterday morning (December 30th) at the Marquette NWS office, we constantlylooked 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. Thereason 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 toevaporative cooling. Surface observations told us when the freezing rain wouldtransition 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 fora couple of hours of freezing rain with little in the way of snow or sleet, we upgradedthe winter weather advisories to ice storm warnings. These warnings wouldeventually verify during the afternoon, with reports of anywhere from 0.25 to 0.5 inchof ice along with plenty of accidents on the roads.

Precipitation type - SnowstormPrecipitation 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 duringthis event.

Use in Local ModelUse in Local Model

AREA FORECAST DISCUSSION...UPDATENWS CLEVELAND OHIOAFDCLE 940 PM EST WED MAR 2 2005

PREV UPDATE... AM SOMEWHAT CONCERNED ABOUT THE CONTINUEDMOISTURE 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 THEMOISTURE WILL EXIT/DISSIPATE AS FAST AS THE MDLS SUGGEST. THE18Z NAM INSISTS ON STRONG LOW LVL CVRG AND UPWARD MOTIONACROSS NW PA. COMBINED WITH THE LK HURON FETCH AND STRONGLYCYCLONIC FLOW CONTINUING INTO THE EARLY MORNING THINK THATLCLY HVY SNOW WILL CONTINUE THRU MIDNIGHT. DATA FROM TAMDARFLIGHT INTO ERI AT 23Z ALSO SHOWS INVERSION STILL ABOVE 6000 FTSO THERE IS STILL PLENTY OF LOW LVL INSTABILITY. NWS MQT WRF RUN FROM 18Z USING THE TAMDAR DATA CONTINUES TO SHOW SIGNIFICANT PCPN FOR NW PA OVERNIGHT.

Sounding ComparisonsSounding 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, MinnesotaInternational 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

Minneapolis, MinnesotaMinneapolis, 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

Need to AddressNeed 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 ScheduleMesaba 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 GLFEInform 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 ApplicationsSevere 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