[LeArc] Forecast Discussion : MLI@ 7/9/2003 2:21:40 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 090717 CCA
AFDMLI

AREA FORECAST DISCUSSION.
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
215 AM CDT WED JUL 9 2003

00Z ANALYSIS CONFIRMS A STRONG SUMMER STORM SYSTEM DROPPING 
SOUTHEAST FROM MONTANA DURING THE NEXT 24 HOURS.  AT THE SURFACE...A 
VERY IMPRESSIVE QUASI STATIONARY FRONT CONTINUES TO LAY FROM NEAR 
KHSI TO SOUTHERN IOWA...TO NEAR KIND. TEMPERATURES CONTINUE TO RUN 
IN THE LOWER 80S ACROSS NORTHERN KANSAS...JUST SOUTH OF THE 
FRONT...AS MUCH COOLER AIR IS PRESENT NORTH...ACROSS THE GREAT 
LAKES.  THIS STABLE AIR SHOULD CONTINUE TO ENHANCE THIS BOUNDARY 
THROUGH THE DAY TODAY...LIKELY KEEPING IT FROM WASHING OUT OR MOVING 
TOO FAR NORTH.  THIS IS A SIGNIFICANT DIFFERENCE FROM SEVERAL 
MODELS...WHICH TAKE THE BOUNDARY WELL NORTH OF THE AREA BY LATE 
AFTERNOON.   

THE PLACEMENT OF THIS BOUNDARY WILL BE CRITICAL TO THE DEVELOPMENT 
OF SEVERE WEATHER THIS AFTERNOON AND EVENING. WHILE THE THREAT OF 
SIGNIFICANT SEVERE STORMS EXISTS OVER THE ENTIRE AREA THROUGH LATE 
EVENING...LOCAL LOW LEVEL SHEAR WILL BE GREATEST NEAR AND JUST NORTH 
OF THIS QUASI STATIONARY BOUNDARY. IF INSTABILITY CAN ESTABLISH 
ITSELF ALONG OR JUST SOUTH OF THE BOUNDARY...THIS IS WHERE THE 
THREAT FOR SUPERCELLS CAPABLE OF PRODUCING TORNADOES WILL BE 
GREATEST. AT THIS TIME...IT APPEARS THE ROUGHLY WEST TO EAST 
BOUNDARY WILL BE BETWEEN INTERSTATE 80 AND HIGHWAY 34 DURING THE 
AFTERNOON AND EARLY EVENING. WILL HIGHLIGHT THIS LOCATION IN THE 
MORNING HAZARDOUS WEATHER OUTLOOK. AS FAR AS POPS GO...WILL WATCH 
THE EVOLUTION OF THE TWO CONSOLIDATING MCS/S TO THE WEST CLOSELY 
BEFORE ISSUANCE TIME.  UNLESS THINGS CHANGE SIGNIFICANTLY IN THE 
NEXT SEVERAL HOURS...PLAN ON GOING CATEGORICAL TODAY AS MORNING 
STORMS ARE REPLACED BY WIDESPREAD AFTERNOON CONVECTION. MODELS HAVE 
SLOWED THE COLD FROPA TO MID EVENING. DESPITE DISAGREEING WITH THE 
EVOLUTION OF THE TRIPLE POINT AND WEST EAST BOUNDARY...WE FEEL THE 
SPEED OF THE UPPER FEATURES IS HANDLED REASONABLY WELL AND THE MAIN 
FRONTAL PASSAGE SEEMS LOGICAL.  WILL KEEP EVENING POPS...ALONG WITH 
SEVERE RISK AND HEAVY RAIN.  FLOOD WATCH ISSUED BY DAYSHIFT 
YESTERDAY WILL BE KEPT GOING THROUGH TONIGHT...AND WILL HIGHLIGHT 
AREAS IN THE SOUTH WHO SAW EXCESSIVE RAIN THIS PAST EVENING. 

NICE COOL DOWN IN NORTHWEST FLOW STILL LOOKS ON TRACK FOR THURSDAY 
THROUGH SUNDAY WITH BENIGN WEATHER. NO SIGNIFICANT CHANGES TO THE 
EXTENDED AT THIS TIME. 

DVN...
IA...FLOOD WATCH TODAY THROUGH LATE EVENING.
IL...FLOOD WATCH TODAY THROUGH LATE EVENING.
MO...FLOOD WATCH TODAY THROUGH LATE EVENING.


$$
ERVIN