[LeArc] Forecast Discussion : MLI@ 5/6/2003 5:02:17 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 060959
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
500 AM CDT TUE MAY 6 2003

08Z SURFACE ANALYSIS SHOWED A WEAK SURFACE LOW OVER LAKE MICHIGAN 
WITH A STATIONARY FRONT EXTENDING SOUTH INTO THE LOWER OHIO RIVER 
VALLEY THEN SOUTHWEST TO A DEVELOPING LOW PRESSURE OVER SWRN OK.
IN THE MID LEVELS...BROAD H5 TROF AS OVER SWRN U.S. WITH EASTERN
TWO THIRDS OF THE U.S. UNDER THE INFLUENCE OF SWLY FLOW.  ISOLATED
TSRA MOVING OUT OF ERN NE EARLIER THIS MORNING MADE IT AS FAR EAST 
AS SW IA BEFORE FALLING APART. 

MODELS GENERALLY AGREE ON THE OVERALL SYNOPTIC PATTERN THROUGH THE 
END OF THE WEEK.  S/W ENERGY EJECTING OUT OF SWRN U.S. TROF SENDS  
SURFACE WAVES ALONG THE FRONT TONIGHT...THURSDAY/THURSDAY NIGHT AND 
AGAIN ON SATURDAY.  I'LL FAVOR THE 00Z GFS SOLUTION FOR THIS 
ISSUANCE...SINCE IT SEEMS TO HAVE A GOOD HANDLE ON THE SHRA/TSRA 
OVER WRN/NRN KS IN THE VICINITY OF THE H8 FRONT THIS MORNING. 

TODAY SHOULD BE DRY FOR THE MOST PART WITH WEAK SURFACE RIDGE OVER 
CWA. A BLEND OF  FWC/MET NUMBERS BASED ON H8 TEMPS AND SOME MID/HIGH
CLOUDINESS BLOWING OFF OF SHRA/TSRA OVER THE PLAINS.  WILL INCLUDE A 
LOW POP IN THE FAR W FOR SHRA/TSRA WITH GFS OMEGA FIELDS SUPPORTING 
PCPN BY LATE AFTERNOON.  SURFACE WAVE MOVING THROUGH WESTERN MO THIS 
EVENING WILL DRAW MID/UPPER 60S SURFACE DEWPOINTS AND H8 DEWPOINTS 
OF 10 TO 12C AS FAR NORTH AS CENTRAL MO...PROVIDING A GOOD MOISTURE 
SOURCE FOR MCS TO TAP TONIGHT. WILL GO WITH LIKELY POPS SOUTHERN 
THIRD OF CWA AND TAPER OFF TO LOW CHANCE POPS IN THE NORTH. NO HYDRO 
HEADLINES WERE ISSUED THIS MORNING...THINKING THAT PROGRESSIVE 
NATURE OF SYSTEM WILL KEEP RAINFALL AMOUNTS FROM EXCEEDING FLASH 
FLOOD GUIDANCE. WITH CWA ON THE COLD SIDE OF THE SYSTEM...ANY SEVERE 
THREAT SHOULD BE LIMITED TO HAIL.  WILL LEAVE SOME LINGERING SHRA IN 
SE GROUPS WEDNESDAY MORNING...OTHERWISE SHOULD BE DRY. NORTHEAST 
SURFACE FLOW WILL BRING COOLER TEMPS TO THE REGION AND WILL USE 
BLEND OF MAV/MET NUMBERS.  NEXT WAVE MOVES OUT OF SOUTHERN PLAINS 
WEDNESDAY NIGHT AND MODELS TRACK IT JUST TO THE NORTH AND WEST OF 
FIRST SYSTEM.  LEFT LOW POPS IN FOR LATE WEDNESDAY NIGHT AHEAD OF 
NEXT SYSTEM WITH GFS SHOWING IMPULSE MOVING OVER AREA AHEAD OF MAIN 
SYSTEM...HOWEVER ITS LOOKING MORE LIKE PCPN ONSET WILL BE LATE IN 
THE DAY THURSDAY.  DAY SHIFT CAN TAKE ANOTHER LOOK AT THE TIMING AND 
ADJUST AS NECESSARY.  THIS SYSTEM LOOKS MORE IMPRESSIVE THAN THE 
FIRST AND HAS A BETTER CHANCE AT PRODUCING SIGNIFICANT RAINFALL OVER 
SOUTHERN HALF OF CWA ALONG WITH A SEVERE HAIL THREAT.  A THIRD 
SYSTEM MOVES THROUGH REGION SATURDAY/SUNDAY BRINGING ANOTHER THREAT 
OF RAIN/SEVERE WX TO THE REGION.


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

$$
DLF