[LeArc] Forecast Discussion : MLI@ 8/21/02 1:47:30 PM

[learc@mailman.qth.net]

The following weather message is provided by McDonough County E.S.D.A.


FXUS63 KDVN 211851
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
151 PM CDT WED AUG 21 2002

SYNOPSIS...
MORNING UA AND SURFACE ANALISIS SHOWS THE AREA IS NOW IN THE WARM AND
MOIST SECTOR.  THE SURFACE WARM FRONT AT 15Z EXTENDS FROM NEAR FSD TO
ALO TO VYS.  WELL DEFINED SHORT WAVE JUST WEST OF MCI AT 12Z...NOW
APPROACHING THE UPPER MIDWEST FROM THE SOUTHWEST.  THIS WAVE HAS
SPAWNED OVERNIGHT CONVECTION FROM KANSAS THROUGH NORTHWEST IOWA.  MUCH
OF THIS IS NOW DECAYING AS EXPECTED...WITH THE EXCEPTION OF PORTION
NEAR MCI.  THIS WILL BE THE CONVECTIVE CLUSTER TO WATCH AS IT
APPROACHES THE CWA THIS AFTERNOON.  CIRRUS AND DEBRIS CLOUDS CONTINUE
TO SLOWLY THIN NORTH OF INTERSTATE 80...WITH MODERATED INSOLATION
ALREADY IN PLACE SOUTH OF THE INTERSTATE.  THIS WILL ALLOW ADEQUATE
HEATING FOR STORMS TO INTENSIFY IN OUR AREA THIS AFTERNOON.


SHORT TERM...
SEVERE WEATHER THREAT WILL MAINLY AFFECT THE AREA THIS EVENING...WITH
HEAVY RAIN EXPECTED LATE EVENING AND OVERNIGHT.  PWAT VALUES IN EXCESS
OF TWO INCHES NOTED ON THE OMA 12Z SOUNDING AND NEAR 2 INCHES ON 18Z
DVN SOUNDING...SHOW TROPICAL AIRMASS OVER THE REGION.  DESPITE MODEL
DIFFERENCES...ALL SHORT TERM MODELS INDICATE DIFFLUENT THICKNESS OVER
THE CWA TONIGHT THROUGH THURSDAY MORNING.  TRAINING CELLS APPEAR TO BE
LIKELY GIVEN NEARY STATIONARY BOUNDARY OVER THE CWA.  ALL THIS SAID...
COUNTY FFG GUIDANCE VALUES ARE RUNNING RATHER HIGH AND CROPS ARE MATURE.
 THEREFORE I FEEL WIDESPREAD FLOODING PROBLEMS DO NOT WARRANT A FLOOD
WATCH AT THIS TIME. URBAN FLOODING MAY BECOME AN ISSUE...IF STORMS PICK
ON ONE AREA REPEATEDLY.  THE FRONT BECOMES QUASI-STATIONARY THURSDAY AND
FRIDAY...WITH SEVERAL ROUNDS OF HEAVY RAIN AND THUNDESTORMS EXPECTED
THROUGH FRIDAY NIGHT.  IF HEAVY RAIN DOES MATERIALIZE TONIGHT...A FLOOD
WATCH MAY BE NEEDED FOR THURSDAY NIGHT AND FRIDAY FOR AREAS THAT RECIEVE
HEAVY RAIN TONIGHT.


EXTENDED...
NO MAJOR CHANGES EXPECTED IN EXTENDED AS CANADIAN HIGH SETTLES SOUTH
ACROSS THE AREA FOR SEVERAL DAYS OF PLEASANT WEATHER.  MRF AND UKMET
CONTINUE TO INDICATE A LOBE UPPER LEVEL VORTICITY WORKING SOUTH
ACROSS THE AREA MONDAY.  FOR NOW...I WILL NOT CHANGES THE GOING
FORECAST...BUT SHOWERS MAY NEED TO BE ADDED IF THIS FEATURE MOVES OVER
THE AREA DURING PEAK HEATING.  OTHERWISE...DRY WEATHER WILL CONTINUE
THROUGH WEDNESDAY...WITH SLOWLY MODERATING TEMPERATURES.



.DVN...
IA...NONE.
IL...NONE.
MO...NONE.

ERVIN/DVN LAST/OMA NEXT