[LeArc] Forecast Discussion : MLI@ 9/17/02 1:35:01 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 171842
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
142 PM CDT TUE SEP 17 2002

FORECAST IS COMPLEX WITH TIMING ISSUES. THE ETA12 EXPERIMENT HAS ALSO
CAUSED GUIDANCE TO BE DELAYED BY 1-2 HRS...ADDING TO THE COMPLEXITY.
RADAR TRENDS AGREE WITH MODELS IN THAT FORCING IN THE LOWER
MISSOURI/OHIO VALLEYS WEAKENING. MODELS SUGGEST THAT THIS PRECIP MAY
JUST BRUSH FAR EASTERN CWFA TONIGHT WHERE BETTER CONVERGENCE/FORCING
LOCATED WHILE LLJ DEVELOPS IN THE PLAINS. LOW LEVEL DRY AIR AND THETA
E MIN LIKELY TO KEEP MUCH OF CWFA DRY BUT CAN/T RULE OUT POSSIBLE
SPRINKLES SOUTH THIRD THIS EVENING. LLJ SHIFTS EAST WEDNESDAY. THIS
COMBINED WITH A WEAK THETA E RIDGE AND SOME FORCING MAY BE ENOUGH TO
ALLOW PRECIP TO DEVELOP IN THE AFTERNOON. THETA E RIDGE/FORCING REMAINS
WED NIGHT SO A BETTER CHANCE OF PRECIP. AVN LOOKS TO SUFFER CONVECTIVE
FEEDBACK THURSDAY. THIS COMBINED WITH LACK OF FORCING IN ALL MODELS
BRINGS TO QUESTION OVERALL PRECIP CHANCES.

NEW AVN IN MARK CONTRAST TO OVERNIGHT AVN IN REGARDS TO COOL DOWN. NEW
AVN KEEPS MOST OF COLD AIR NORTH WITH JUST A GLANCING BLOW BY EARLY
NEXT WEEK. STRONG NORTHWEST FLOW ON FRIDAY SUGGESTS A SUBTLE WAVE WHICH
MAY GENERATE SOMETHING. CURRENT FORECAST IS DRY SO WILL LEAVE DRY FOR
NOW AS WELL. SUNDAY/MONDAY DRY AS WELL WITH ANOTHER SYSTEM APPROACHING
FOR LATE MONDAY/TUESDAY. FOR NOW WILL LEAVE TUESDAY DRY DUE TO
QUESTIONABLE TIMING/CONTINUITY OF MODELS.

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

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