[LeArc] Forecast Discussion : MLI@ 2/25/03 3:32:01 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 252140
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
340 PM CST TUE FEB 25 2003

SURFACE RIDGE CENTERED JUST EAST OF THE CWA HELPING TO KEEP COLD... 
DRY...ALMOST ARCTIC AIR OVER THE CWA TODAY.  UPPER LEVEL ANALYSIS 
AND IR SATELLITE IMAGERY SHOWING A SHORTWAVE PROGRESSING ACROSS  
SOUTHERN IA INTO IL...BUT DESPITE SOME ECHOES ON THE RADAR...ONLY 
CLOUDS REPORTED ON OBS.  SOUNDING FROM THIS MORNING INDICATING VERY 
DRY LOW LAYERS...KEEPING ANY PRECIP FROM MAKING IT TO THE GROUND.  

MAIN CONCERN THIS FORECAST INCLUDES TEMPS NEXT FEW DAYS...AND 
PRECIPITATION CHANCES FRIDAY THROUGH THE WEEKEND.

12Z MODELS IN DECENT AGREEMENT THROUGH MOST OF THE NEAR TERM 
FORECAST...WITH DRY CONDTIONS THROUGH FRIDAY.  THERE ARE A SERIES OF 
SHORT WAVES THAT MOVE ACROSS THE MID WEST...BUT NONE OF THEM WITH 
ENOUGH MOISTURE OR GET CLOSE ENOUGH WITH THE LIFT TO PRODUCE MORE 
THAN FLURRIES AT THE MOST FOR THE CWA.  WILL BE USING A BLEND OF THE 
AVN/ETA FOR THIS FORECAST.

CLEARING CONDITIONS TONIGHT WILL ALLOW TEMPS TO DROP OFF 
AGAIN...THOUGH WITH LIGHT SOUTHERLY FLOW NOT AS COLD AS THIS 
MORNING.  UPSTREAM TEMPS UNDER AND JUST NORTH OF THE RIDGE WITH 
SIMILAR 1000-850THKNESS VALUES RANGE FROM 0 TO 5 BELOW.  WITH SOME 
MODERATION AND CLOUDS EARLY THIS EVENING...FEEL WE COULD COMFORTABLY 
BE RANGING FROM AROUND ZERO TO NEAR 5 ABOVE ZERO.  

WEDNESDAY THE SURFACE RIDGE REMAINS IN CONTROL...WITH LOW CLOUDS AND 
PRECIP AGAIN SUPPRESSED TO THE SOUTH.  CLOUDS AND SNOW COVER SOUTH 
WILL KEEP TEMPS FROM RISING MUCH...AND WITH ADVECTION FROM THE SOUTH 
WILL BE HARD TO GET WARM THERE EITHER.  CURRENT FWC GUIDANCE AND 
GOING FORECAST LOOK TOO WARM...AND WILL TWEAK DOWN 3-5 FOR A LOWER 
RANGE ACROSS CWA.

WEDNESDAY NIGHT...HIGH MOVING OFF TO THE EAST WILL KEEP TEMPS 
MODERATED FROM TONIGHT...BUT STILL ON THE CHILLY SIDE.  MAV TEMPS 
SIMILAR TO GOING FORECAST AND WILL NOT CHANGE MUCH.

THURSDAY AND THURSDAY NIGHT TEMPS FINALLY MODERATING SOME AS MORE  
SUNSHINE THAN ON PREVIOUS DAYS.  HOWEVER...FEEL THAT GUIDANCE TEMPS 
TOO WARM WITH A LITTLE SNOW ON THE GROUND AND SURFACE RIDGE STILL IN 
PLACE.  HAVE GONE BELOW GUIDANCE BOTH PERIODS.

FRIDAY AND FRIDAY NIGHT WE FINALLY GET SOME DECENT SOUTHERLY FLOW 
AHEAD OF THE NEXT SYSTEM...BUT WITH THIS SYSTEM DIVING TOO FAR SOUTH 
TO BRING IN PRECIP...EFFECT IS REDUCED.  HAVE TAPERED BACK ON 
FRIDAYS HIGHS...LOW TO MID 30S INSTEAD OF MID TO UPPER...AND GONE 
WITH THE COLDER FMR TEMPS FOR FRIDAY NIGHT.

.EXTENDED...SAT-TUE
SOME BIG DIFFERENCES IN THE MODEL SOLUTIONS THIS TIME FRAME... 
ESPECIALLY FOR THE WEEKEND. HAVE STAYED FAIRLY CLOSE TO GFS 
SOLUTION...BUT HAVE KEPT TO LOW POPS FOR SATURDAY AS THE ECMWF HAS A 
MUCH WEAKER SYSTEM THAN THE GFS.  HAVE GONE WITH COLDER FMR TEMPS 
FOR THE MOST PART.

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

$$

LRE