[LeArc] Forecast Discussion : MLI@ 4/21/2003 3:46:26 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 210844
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
344 AM CDT MON APR 21 2003

WELL DEFINED TROUGH SEEN ON SATELLITE EXTENDING SOUTHWEST FROM 
STACKED LOW OVER LAKE SUPERIOR TO EASTERN NEB. AREA 88DS AND SURFACE 
REPORTS SHOW LIGHT RAIN AND DRIZZLE IN WI INTO SOUTHERN MN EARLY 
THIS MORNING AND INITIAL CHALLENGE IS PROBABILITY OF MEASURABLE 
PRECIP THIS MORNING...THEN LONGER TERM TEMPERATURE TRENDS.

MODELS AGAIN IN CLOSE ENOUGH AGREEMENT WITH INITIALIZATION AND 
FEATURES THROUGH MIDWEEK...SO FOLLOWED BLEND OF GFS AND MESO-ETA IN 
SHORT TERM. 88D TREND HAS SHOWN WEAKENING AREA OF DRIZZLE AND LIGHT 
RAIN AS TROUGH ROTATES TOWARD NORTHEAST IA EARLY THIS MORNING. BEST 
LOW LEVEL CONVERGENCE PASSES OVER NORTHEAST THIRD OF CWA AND WITH 
METARS SHOWING MEASURABLE RAIN UPSTREAM...WILL HAVE TO CARRY 
SIGNIFICANT POP IN THIS AREA. OTHERWISE...REST OF AREA SHOULD SEE NO 
MORE THAN MORNING SPRINKLES OR DRIZZLE. LOW LEVEL MOISTURE 
PROGS BACK UP GOING TREND OF KEEPING LOW CLOUDS IN PLACE THROUGH 
MOST OF DAY WITH BREEZY NW FLOW LIMITING TEMPERATURES CLOSE TO MAV 
AND META 2M TEMPERATURES IN 50S. COULD SEE SOME BREAKS IN CLOUDS 
MUCH LIKE YESTERDAY...MAINLY IN WEST WHERE KEPT HIGHS IN UPPER 50S. 
TONIGHT...INVERTED RIDGE SLIDES INTO WESTERN IA BY 12Z. EXPECT 
CLEARING TO TAKE PLACE OVER ENTIRE AREA BY LATE EVENING AS LOW LEVEL 
MOISTURE AND CYCLONIC LOW FLOW SHIFTS EAST. WITH DEEP NW COLD 
ADVECTION FLOW...MAY TAKE A WHILE TO DECOUPLE...BUT STILL EXPECTING 
GOOD DROP WITH ADVECTION OF DRY AIR. GUIDANCE HAS COME CLOSER TO 
LOCAL FORECAST TRENDS AND STAYED COURSE WITH LOWER TO MID 30S.
TUESDAY TO SEE LOTS OF SUNSHINE WITH RIDGE AXIS MOVING OVER AREA...
BUT WITH COLD START AND LIGHT NORTHERLY FLOW WILL STAY JUST BELOW 
COOL END OF GUIDANCE IN UPPER 50S TO LOWER 60S. DRY AIRMASS TO COOL 
QUICKLY WEDNESDAY MORNING WITH WEAK RETURN FLOW NOT ARRIVING QUICKLY 
ENOUGH TO PREVENT DROP INTO 30S...AT LOW END OF GUIDANCE.

MEDIUM RANGE GUIDANCE IN CLOSE AGREEMENT WITH CLOSED UPPER LOW 
MOVING OUT OF CENTRAL ROCKIES TO NW KS THURSDAY MORNING. SIGNIFICANT 
DIFFERENCES DEVELOP AS WAVE SHOWN TO OPEN AND MOVE INTO MO ON 
FRIDAY. GFS MOST AGRESSIVE WITH KEEPING CLOSED CIRCULATION...WHILE
UK AND ECMWF OPEN WAVE AND SCOOT IT MUCH FASTER TO THE EAST. 
SOLUTIONS STILL POINT TOWARD A COOL RAIN EVENT...ESPECIALLY IN THE 
SOUTH BEGINNING LATE THURSDAY LASTING INTO FRIDAY. MADE SOME 
ADJUSTMENTS TO REFINE LIKELY POPS TO SOUTH AND EXTEND INTO FRIDAY. 
ONLY MINOR TEMPERATURE CHANGES BEYOND INTO WEEKEND.  

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

$$
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