[LeArc] Forecast Discussion : MLI@ 3/11/03 4:18:22 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 112224
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
425 PM CST TUE MAR 11 2003

ALMOST SPRING LIKE PATTERN APPEARANCE TO THE 18Z SFC ANALYSIS THIS 
AFTERNOON...WITH 15 TO 20 KT SOUTHERLY SURFACE FLOW AT THE 
SURFACE...AND SOME 30+ DEWPOINTS POOLING AHEAD OF A COLD FRONT 
MOVING TOWARDS THE CWFA FROM THE DAKOTAS/MN/WI AREA.  THERE IS SOME 
PRECIP RIGHT BEHIND THIS FRONT...WITH LOW CIGS AND VSBYS IN SN.  
GOOD PRESSURE FALLS ALL AHEAD OF THE FRONT OVER ALL OF CWA. 

MAIN FORECAST CONCERN THIS FORECAST INCLUDES PRECIP CHANCES TONIGHT 
AND AGAIN WEDNESDAY NIGHT...AND HOW WARM TO GO WITH TEMPS.

OF THE 12Z MODEL RUNS...ONLY THE AVN SEEMS TO HAVE EVEN A HINT OF 
THE PRECIPITATION CURRENTLY FALLING ACROSS THE DAKOTAS BORDER INTO 
MN...EVEN THOUGH IT HAS TOO MUCH PRECIP TO THE SOUTH OF THE FRONT.  
ETA HAS NO PRECIP IN THESE LOCATIONS AT ALL.  LIKE THE PREVIOUS 
SHIFT...PREFER THE AVN FOR BOTH ITS HANDLING OF THE PRECIP BEHIND 
THE FRONT...AND THE POSITION OF THE FRONT OVER THE NEXT 24 HOURS.  
BULLISH PRECIP AHEAD OF FRONT CAN BE ACCOUNTED FOR.

TONIGHT AM CONCERNED THAT THE PRECIP CURRENTLY BEHIND THE FRONT WILL 
AFFECT ABOUT THE NORTHERN HALF OF THE AREA AS IT SHIFTS TO DRAPE 
ACROSS THE FAR SOUTHERN PORTIONS OF THE CWA.  HAVE PUT IN LOW 
POPS...MAINLY FOR AFTER MIDNIGHT TONIGHT.  TEMPS NEXT FEW DAYS ON 
THE TRICKY SIDE...WITH A LARGE RANGE ACROSS THE CWA DUE TO THE FRONT 
LINGERING ACROSS THE SOUTHERN PORTIONS OF THE CWFA.  
TOMORROW/WEDNESDAY AFTERNOON/NIGHT IS THE NEXT CHANCE OF PRECIP...AS 
AN INVERTED TROUGH/WEAK LOW MOVES ACROSS CENTRAL MO.  HAVE KEPT POPS 
IN THE CHANCE CATEGORY STILL...AS THERE IS SOME QUESTION AS TO 
WHETHER THE OVERRUNNING MOISTURE WILL BE ABLE TO SATURATE THE LOWER 
LAYERS BEFORE THE EVENT IS OVER.  WEDNESDAY AFTERNOON POPS A LITTLE 
SCARCE..AND HAVE KEPT THEM ON THE LOW SIDE OF CHANCE.  THURSDAY AND 
FRIDAY RATHER QUIET AS HIGH BRUSHES AREA TO THE NORTH AND EAST...AND 
SOUTHERLY FLOW KICKS IN ON FRIDAY.  LATER SHIFTS MAY HAVE TO UP 
TEMPS ON FRIDAY...THOUGH HAVE STUCK FAIRLY CLOSE TO GUIDANCE VALUES 
FOR NOW.  

EXTENDED...(SAT-TUE)
MAIN FEATURE OF INTEREST DURING THE EXTENDED IS THE PATTERN SHIFT 
FROM ZONAL TO A LARGE UPPER LEVEL LOW THAT SWINGS ACROSS THE 
SOUTHWESTERN US...AS DEPICTED IN VARIOUS SPEEDS AND STRENGTHS ON THE 
00Z AND 12Z GFS...THE ECMWF...AND UKMET MODELS.  FROM EARLIER 
AFDS...THIS APPEARS TO BE RELATIVELY NEW...AND AM NOT GOING TO GET 
TOO EXCITED ABOUT THIS THING JUST YET.  NO MATTER WHAT...WE ARE 
LOOKING AT ABOVE NORMAL TEMPERATURES THROUGH THE PERIOD...AND RAIN 
CHANCES FOR SUNDAY THROUGH TUESDAY.  THIS SYSTEM MAY END UP BEING 
MUCH WEAKER AND MORE TO THE SOUTH THAN CURRENT DEPICTIONS...SO HAVE 
KEPT TO CHANCE POPS.  

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

$$

LRE