[LeArc] Forecast Discussion : MLI@ 1/29/03 3:13:34 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 290922
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
322 AM CST WED JAN 29 2003

LOW CLOUDS CLEARING FROM NORTH EARLY THIS MORNING AS DRIER AIR 
PUSHES SOUTH AHEAD OF SURFACE HIGH MOVING INTO NORTH DAKOTA. COLD 
FRONT THAT PRODUCED PRECIPITATION OVER AREA NOW WELL TO SOUTHEAST. 
WEAK SHORTWAVE UPSTREAM MOVING THROUGH SOUTH DAKOTA PRODUCING -SN 
PROGGED TO REMAIN TO WEST OF CWFA TODAY. INITIAL FORECAST CHALLENGE 
IS TEMPERATURES AS CANADIAN HIGH SETTLES OVER AREA...THEN CHANCES 
FOR PRECIPITATION WITH NEXT SIGNIFICANT SYSTEMS THURSDAY 
NIGHT/FRIDAY AND SUNDAY/SUNDAY NIGHT. 

SHORT TERM MODELS SIMILAR WITH SURFACE HIGH BUILDING SOUTHEAST TO 
CENTER OVER SOUTHEAST IA AROUND 00Z. WEAK MID LEVEL FORCING 
ASSOCIATED WITH DAKOTAS SHORTWAVE WILL STAY WELL TO WEST WITH MAIN 
IMPACT BEING SOME MID AND HIGH CLOUDS OVER THE WEST BY AFTERNOON.
SOME VERY WEAK MID LEVEL FORCING REACHES INTO SOUTHEAST IA BY LATE 
AFTERNOON AND COULD PRODUCE FLURRIES...BUT WITH JET LEVEL 
CONVERGENCE WILL LEAVE OUT. ARCTIC AIRMASS OVER MN WILL CONTINUE TO 
PUSH SOUTH TODAY AND WITH SNOW COVERING MOST OF CWFA...WILL BE 
DIFFICULT TO WARM MUCH. WENT CLOSE TO MAV GUIDANCE. TONIGHT...WITH 
HIGH OVERHEAD WILL SEE RAPID COOLING IN EVENING BEFORE RETURN FLOW 
DEVELOPS AND TEMPERATURES BECOME STEADY OR RISE SOME. CONTINUED 
ABOUT A CATEGORY BELOW MOS AND CLOSE TO META 2M TEMPS WITH 
WIDESPREAD LOWS IN SINGLE DIGITS. THURSDAY WILL SEE SIGNIFICANT WARM 
UP WITH SW FLOW AHEAD OF DEVELOPING HIGH PLAINS CYCLONE AND SHOULD 
BE ABLE TO REACH INTO 30S DESPITE COLD START.

ALL MODELS KEEP LOW WELL TO NORTH WITH COLD FRONT PUSHING THROUGH 
AROUND 12Z FRIDAY. BIG QUESTION IS PRECIP TYPE. DESPITE SNOW COVER...
THINK TEMPERATURES WILL DROP BELOW FREEZING ACROSS SOUTH IN EVENING. 
THERE...FORECAST SOUNDINGS INDICATE RAIN...SO WILL CONTINUE WITH ZR 
OR S WORDING. NORTH OF I-80...STILL LOOKS LIKE MAINLY S. RAISED POPS 
UP INTO 40 TO 50 RANGE.

PATH OF STRONGER CYCLONE ON SUNDAY SIMILAR BETWEEN LATEST GFS AND 
ECMWF...BUT SIGNIFICANT TIMING ISSUES REMAIN. BOTH AGREE WITH LOW TO 
TRACK MAINLY NORTH...KEEPING MOST OF CWFA IN WARM SECTOR BEFORE 
FROPA TO INDICATE RAIN INITIALLY ON SUNDAY AND THEN SNOW IN WRAP 
AROUND ESPECIALLY NORTH SUNDAY NIGHT AND EARLY MONDAY. THIS IS IN 
LINE WITH CURRENT FORECAST AND NO SIGNIFICANT CHANGES MADE. 

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

$$
DLS