[LeArc] Forecast Discussion : MLI@ 6/14/02 1:37:34 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 140637
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
130 AM CDT FRI JUN 14 2002

.OVERVIEW...STRONG...LATE SPRING CLOSED LOW OVER MINNESOTA SPINNING
SOUTHEAST AT 15-20 MPH.  SYSTEM HAD LOTS OF DIURNAL DRIVEN CLOUDS AND
SHOWERS AND STORMS IN CENTER OF COLD AIR THU PM WITH HIGHS ONLY IN
MID 50S TO MID 60S THERE.  TRAJECTORIES SUPPORT AIR THIS PM TO BE COMING
FROM NEAR FARGO THU WHICH MEANS VERY COOL TEMPS...EVEN WITH SOME
MODIFICATION.  UPPER AIR ANALYSIS SUPPORTS SYSTEM TO MOVE SOUTHEAST OVER
OUR REGION TODAY WITH DECENT AMOUNT OF LOW LEVEL MOISTURE ALSO LOTS OF
PM CLOUDS AND CHANCE OF SHOWERS AND A FEW STORMS.

...DETERMINING HEATING DRIVEN POPS AND IMPACT ON TEMPS MAIN FORECAST
ISSUE...

.DIAGNOSIS AND DAYS 1-3...MODELS ARE REASONABLE ON LARGER SCALE FEATURES
WITH NORMAL MODEL BIASES AT 06Z.  ETA IS CLOSEST ON ROTATING SHORT WAVES
BUT NOWCAST TOOLS SUGGEST MORE VIGOROUS ENERGY SOUTHWEST OF ALL MODELS.
THIS WILL AFFECT ALL OUR AREA WITH HIGHEST POPS EAST OF I-380
CORRIDOR BY MID DAY...THUS WILL GO A TAD HIGHER ON PM POPS AS CONVECTIVE
TEMPS TO BE REACHED AND LOTS OF UPPER LEVEL VORTICITY/COOL AIR ALOFT.
USE PERSISTENCE FROM TEMPS WED PM AND COMBINE WITH FWC/MAV TEMPS TO
ADJUST HIGHS TODAY WITH ETA 2M ABOUT 3-5 DEGREES TOO WARM.  RESULT WILL
BE A TREND NEAR TO SLIGHTLY BELOW GUIDANCE FOR MAX TEMPS AS SKIES BECOME
MOSTLY CLOUDY WITH LOTS OF POPCORN SHOWERS AND FEW STORMS BY EARLY
AFTERNOON.  BLUSTERY NW WINDS TO INCREASE BY LATE MORNING TO 15 TO 25
MPH WITH SOME GUSTS TO NEAR 30 MPH TO MAKE FOR A SEASONABLY COOL DAY.
THEN CLEARING TONIGHT WITH LOW TEMPS NEAR MAV/FWC FOR COOL NIGHT AND
ALSO FOR NIGHT THIS WEEKEND.  WARMER ON SATURDAY BUT THEN REINFORCING
SHOT OF COOLER AIR LATE SATURDAY WILL KEEP TEMPS BELOW NORMAL.   LIMITED
MOISTURE...TRIGGER AND BOUNDARY SUPPORT REMOVING POPS THO FOR A NICE
BUT COOL TO MILD WEEKEND.

.EXTENDED (MON-THU)...GRADUAL WARMUP OCCURS WITH INCREASING CHANCE OF
SHOWERS AND STORMS LATE MON INTO WEDNESDAY.  MODELS VARY ON STRENGTH OF
NEXT FRONT LATE WED INTO THURSDAY AND LEAVE FOR DAY SHIFT TO CONSIDER.

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

NICHOLS