[LeArc] Forecast Discussion : MLI@ 4/15/2003 4:07:25 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 152101
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
400 PM CST TUE APR 15 2003

ANOTHER VERY WARM DAY ACROSS THE CWA...WITH STRONG SOUTHERLY FLOW 
GUSTING TO AROUND 30 MPH.  TEMPERATURES ARE CLOSE TO WHAT THEY WERE 
YESTERDAY AT THIS TIME...ONLY A FEW DEGREES DIFFERENT AS OF 3 PM.  
DEVELOPING WARM FRONT ACROSS SOUTHERN MINNESOTA AND CENTRAL 
WISCONSIN IS NEARLY STATIONARY ATTM. SURFACE LOW OVER WESTERN 
NEBRASKA HAS BEEN SLOWLY DEEPENING AND SHIFTING SOUTH DURING THE DAY 
TODAY...THOUGH PRESSURE FALLS OVER NEBRASKA AND KANSAS HAVE BEEN 
INCREASING...SO EXPECT THE LOW TO BEGIN MOVING EAST SOON.  
THUNDERSTORMS HAVE 

MAIN CONCERN IN THE NEAR TERM...TONIGHT THROUGH WEDNESDAY 
NIGHT...INCLUDES THE POSITION OF THE FRONT AS IT DROPS SOUTH ACROSS 
THE CWA.  THIS IN TURN AFFECTS THE ONSET OF PRECIPITATION LATE 
TONIGHT...AND TEMPERATURES ON WEDNESDAY WITH THE FRONT IN THE 
VICINITY.  IN GENERAL PREFER HOW THE ETA IS CURRENTLY HANDLING THE 
SURFACE LOW AND FRONT...AND HOW IT BRINGS THE FRONT SOUTH OVERNIGHT 
TONIGHT.  ETA SEEMS TO HAVE A DECENT HANDLE ON HOW SURFACE FRONTS 
MOVE THIS TIME OF YEAR...USUALLY SETTLING JUST SOUTH OF LAKE 
MICHIGAN...EXTENDING WEST TO ALONG OR A LITTLE NORTH OF INTERSTATE 
80.  THE FRONT CONTINUES TO SHIFT SLOWLY SOUTH AS THE LOW CENTER 
MOVES EAST.  TONIGHT...DEWPOINTS...LIFT...AND INSTABILITY DO NOT 
REALLY COME TOGETHER OVER THE CWA UNTIL NEARLY 12Z...AND WHILE I 
THINK THAT WE WON'T SEE ANYTHING UNTIL AFTER 09Z...HAVE USED AFTER 
MIDNIGHT WORDING IN THE ZFP.  

WEDNESDAY...THINGS COULD GET VERY INTERESTING...WITH SOME MODERATE 
CAPES...DECENT SHEAR WITH THE SURFACE LOW CENTER PASSING ACROSS 
CENTRAL MO...AND THE WARM FRONT STILL HANGING OUT ALONG SOUTHERN 
PORTIONS OF THE CWA.  THUNDERSTORMS ARE QUITE LIKELY...BUT BEST 
CHANCES FOR SEVERE THREAT WILL BE WILL BE SOUTH OF THE CWA...AHEAD 
OF THE SURFACE LOW.  THUNDERSTORMS FOR OUR AREA MAY BE ABLE TO 
PRODUCE MARGINAL HAIL AND WIND GUSTS...BUT NOT EXPECTING MUCH 
WORSE.  BY WEDNESDAY NIGHT...THE LOW CONTINUES TO PULL EAST...AND 
THUNDERSTORM THREAT DIMINISHES GREATLY...CONVERTING TO DEFORMATION 
ZONE RAIN.

SYSTEM PULLS EAST OF REGION THURSDAY AS IT MOVES THROUGH CENTRAL IL 
INTO CENTRAL INDIANA.  BOTH GFS/ETA SUGGEST ABUNDANT LOW LEVEL WRAP 
AROUND MOISTURE AND WEAK LOW LEVEL CONVERGENCE ACROSS CWA EARLY 
THURSDAY.  THIS SUPPORTS CHANCE POPS IN CURRENT FORECAST AND WILL 
CONTINUE.  COLD...MOIST WRAP AROUND FLOW ALSO SUPPORTS GOING TEMP 
FORECAST FOR MAXES THURSDAY WITH NORHTERN HALF OF CWA STAYING IN THE 
40S.  MET SUGGESTING MID 50S IN THE SOUTH WHICH LOOKS TO WARM AND 
WILL SIDE WITH COOLER MAV NUMBERS...IN THE LOW 50S.  

NEXT SYSTEM TO IMPACT REGION WILL MOVE OUT OF THE PLAINS LATE FRIDAY 
AND THROUGH THE REGION ON SATURDAY.  THE GFS/UKMET ARE SIMILAR WITH 
THE TRACK OF THE SYSTEM THROUGH SUNDAY...WITH THE UKMET 
SLOWER...ESPECIALLY LATE IN THE WEEKEND.  WITH HIGH AMPLITUDE OF MID 
LEVEL WAVE WILL TREND TOWARD THE SLOWER UKMET SOLUTION.  SYSTEM 
SHOULD BE EAST OF REGION BY BEGINNING OF NEXT WEEK AND WILL KEEP 
FORECAST DRY.

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

$$

LRE