[LeArc] Forecast Discussion : MLI@ 9/24/02 2:58:30 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 240806
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
305 AM CDT TUE SEP 24 2002

BROAD UPPER LEVEL TROUGH OVER CONUS WITH SHORTWAVE MOVING THROUGH 
THE FLOW.  LOW LEVELS REFLECTING THESE SHORTWAVES IN SMALL...BUT 
INTENSE...CLIPPER LIKE SYSTEMS ROLLING ACROSS THE UPPER MID WEST.  
SATELLITE IMAGERY INDICATING ONE OF THESE SYSTEM MOVING ACROSS THE 
GREAT LAKES AREA...AND ANOTHER DROPPING SOUTH OUT OF B.C.  MAIN 
STORY IN THE CWA THIS MORNING ARE THE VERY CHILLY TEMPS...TEMPS 
CURRENTLY RANGING FROM UPPER 30S TO MID 40S.  EXPECT WIDESPREAD 
FROST OVER NORTHWEST THIRD OF CWA.  

MAIN FORECAST PROBLEM THIS MORNING ARE ASSOCIATED WITH THE TIMING OF 
A FRONT DUE THROUGH CWA ON WEDNESDAY NIGHT/THURSDAY.  

00Z MODELS APPEAR TO HAVE INITIALIZED FAIRLY WELL.  MAIN FEATURE TO 
WATCH IS THE MOVEMENT OF THE FRONT PROGGED TO MOVE THROUGH THE AREA 
WEDNESDAY NIGHT.  ON THIS FEATURE...ETA IS SLOWER THAN THE PREVIOUS 
RUN...WITH THE AVN SHOWING BETTER AGREEMENT WITH ITS PREVIOUS RUN.  
IN GENERAL...DUE TO THEIR SIMILARITY WILL BE GOING WITH A BLEND OF 
AVN AND ETA...WITH A DEFINITE LEAN TOWARDS THE AVNS SLIGHTLY SLOWER 
SOLUTION.

WEDNESDAY NIGHT POPS BASED ON THE FRONT BEING ABLE TO PULL TROPICAL 
MOISTURE NORTH QUICKLY ENOUGH.  HAVE SIGNIFICANT DOUBTS ABOUT 
THIS...AND SO HAVE KEPT POPS IN THE LOW CHANCE CATEGORY.  
THURSDAY...WITH THE FRONT TO THE EAST AND THE TROPICAL MOISTURE 
FINALLY ABLE TO MAKE IT INTO THE AREA...PRECIP CHANCES LOOK MUCH 
BETTER AND HAVE GONE WITH HIGH CHANCE POPS.  IF LATER SHIFTS SEE 
THAT IT STILL LOOKS GOOD TO GET TROPICAL MOISTURE INTO REGION POPS 
MAY NEED TO BE RAISED MORE.

FOR TEMPS WILL BE GENERALLY USING THE AVN MOS TEMPS...WITH SOME 
TWEAKS FOR LOCAL EFFECTS AND TRENDS.

DO NOT PLAN ON MAKING ANY CHANGES TO THE FRIDAY TO MONDAY FORECAST.  

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

LRE