[LeArc] Forecast Discussion : MLI@ 11/14/02 4:10:10 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 142215
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
415 PM CST THU NOV 14 2002

SURFACE COLD FRONT DRAPED ACROSS CWA HAS MORE OR LESS REMAINED 
NEARLY STATIONARY THROUGH THE DAY TODAY...WITH PRECIPITATION ALONG A 
SURFACE TROUGH JUST TO ITS SOUTHEAST.  THIS SURFACE TROUGH HAS BEEN 
SLOWLY MOVING EAST...AND THE PRECIPITATION HAS BEEN MOVING ALONG 
WITH IT AS AN UPPER LEVEL VORT MAX MOVES THROUGH CWA.  A 
SECONDARY...WEAKER VORT MAX IS ASSISTING SOME LIGH PRECIPITATION 
ALONG THE IA/MN BORDER...WHICH MAY BRUSH THE NORTHERN COUNTIES 
TONIGHT.

MAIN FORECAST CONCERN TONIGHT IS THE CLOUDS AND TEMPERATURES THROUGH 
SATURDAY.

12Z MODELS ARE IN GOOD AGREEMENT...WITH UPPER LEVEL TROUGH NOT 
EXITING THE AREA UNTIL LATE FRIDAY...THOUGH THE VORT MAX MOVES EAST 
OF THE CWA BY 06Z TONIGHT.  MAIN MODEL DIFFERENCES SHOW UP AROUND 48 
HRS...WITH THE ETA EJECTING THE UPPER LEVEL LOW MORE QUICKLY THAN 
THE AVN...NGM...OR UKMET.  AVN APPEARS TO BE VERIFYING A LITTLE 
BETTER THAN THE ETA ON THE SURFACE AND UPPER LEVEL FEATURES...SO 
HAVE MAINLY BASED FORECAST OFF OF IT.  

BACK EDGE OF PRECIPITATION IS ALMOST TO THE MISSISSIPPI FOR ALL OF 
CWA NOW...AND IS MAKING GOOD PROGRESS TO THE EAST.  THE MAIN BAND OF 
VERY LIGHT PRECIP SHOULD EXIT CWA BY ABOUT 2Z...LEAVING ONLY 
SPRINKLES FOR THE REST OF THE EVENING.  AS FOR CLOUDS...THERE IS A 
LITTLE BIT OF DRYING CAUSING THE SMALL CLEARING AREA THIS EVENING 
AROUND CID...BUT THE LOW CLOUDS OVER NRN IA SHOULD MOVE IN AND HANG 
ON TIL MORNING.  HAVE ALSO GONE PESSIMISTIC WITH THE LOW CLOUDS ON 
FRIDAY AND FRIDAY NIGHT...AS WE REMAIN IN CYCLONIC FLOW AT ALL 
LEVELS...WITH ENOUGH LOW LEVEL MOISTURE FOR THOSE CLOUDS.  WITH 
INCREASE IN CLOUDS TONIGHT AND FRIDAY NIGHT FROM PREVIOUS 
FORECAST...HAVE GONE WARMER THAN PREVIOUS FORECAST...THOUGH STILL 
COLDER THAN THE MAV GUIDANCE.  THERE IS STILL A BIG QUESTION MARK 
ABOUT WHETHER LOW CLOUDS WILL MAKE IT IN HERE SATURDAY MORNING WITH 
THE LOW LEVEL NORTHEAST FETCH OFF THE LAKE.  FOR NOW HAVE GONE ON 
THE PESSIMISTIC SIDE...AND CAN MODIFY LATER.  SATURDAY SHOULD SEE 
SOME REAL CLEARING...THOUGH WITH CAA STILL ONGOING...TEMPS SHOULD 
STAY ON THE COOL SIDE.  SUNDAY WILL SEE THE REAL WARM-UP...AND HAVE 
GONE QUITE A BIT WARMER THAN SATURDAY.

EXTENDED...HAVE ADJUSTED TIMING FOR MONDAY SYSTEM TO MORE DURING THE 
DAYTIME RATHER THAN SUNDAY NIGHT AS THE WAVE SEEMS TO BE DELAYED A 
LITTLE ON THE EXTENDED RANGE MODELS.  NEAR TERM MODELS ARE STILL 
FAIRLY FAST THOUGH...THIS MAY NEED TO BE ADJUSTED AGAIN LATER.  NEXT 
BIG QUESTION IS TUESDAY-  THE 12Z UKMET BRINGS IN A MUCH STRONGER 
SYSTEM THAT DIGS MUCH FARTHER SOUTH THAN EITHER THE 00Z GFS OR ECMWF 
OR THE 120H OF THE 12Z AVN/GFS ARE HINTING AT.  FOR NOW HAVE 
RETAINED DRY FORECAST...THOUGH HAVE INCREASED CLOUDS AS A TREND 
SHOULD OTHER MODELS BEGIN TO FOLLOW UKMET SOLUTION.  WEDNESDAY AND 
MOST OF THURSDAY LOOK DRY...THOUGH THURSDAY ANOTHER WAVE DIVES OUT 
OF THE NORTHERN ROCKIES...AND PUSHES THROUGH THE AREA. 

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

LRE