[LeArc] Forecast Discussion : MLI@ 10/1/02 2:06:52 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 011913
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
205 PM CDT TUE OCT 1 2002

ACTIVE WEATHER PATTERN UNFOLDING FOR REGION THROUGH THE WEEKEND.  
MID LEVEL SW FLOW STRENGTHENING AS WEST COAST TROUGH DEEPENS AND 
UPPER RIDGE HOLDING ON OVER SERN U.S.  MSAS PLACES SURFACE FRONT 
ACROSS NW IA THROUGH ERN NE INTO WAVE OVER NORTH CENTRAL KS.  WATER 
VAPOR LOOP SHOWS EMBEDDED S/W OVER ERN NE AT 18Z WHICH SUPPORTING 
CLUSTER OF 
SHRA/TSRA FROM CENTRAL INTO E CENTRAL/NE IA.  TSRA LIGHTING ON 
SOUTHERN FRINGE OF CLUSTER AS IT ENCOUNTERS MORE AVAILABLE 
INSTABILITY OVER NE MO/CENTRAL IL.  

IN THE SHORT TERM MODELS ARE IN AGREEMENT MOVING ERN NE IMPULSE ENE 
INTO WI THIS EVENING AND SHOVING SURFACE FRONT SE TO NEAR A 
STJ-MLI-RFD LINE BY 12Z WEDNESDAY.  MODELS...ESPECIALLY 
AVN...ADVERTISING A COUPLED JET STRUCTURE EVOLVING OVERNIGHT AS 
SOUTH CENTRAL CANADA JET INCREASES TO AROUND 12OKTS AND WITH A 100KT 
JET NOSING INTO CENTRAL NE BY 12Z WED.  THIS COMBINED WITH 850 FRONT 
OVER IA AND PW AROUND 1.5 INCHES SHOULD PROVIDE LIFT...GOOD MOISTURE 
SOURCE AND FOCUS FOR SOME DECENT RAINS LATE TONIGHT AND EARLY 
WEDNESDAY OVER NORTHERN SECTIONS OF CWA.  CURRENT FORECAST PACKAGE 
ALREADY HAS HEAVY RAIN MENTIONED AND WILL CONTINUE.  A SURFACE WAVE 
RIDING ALONG THE FRONT WEDNESDAY KEEPS FRONT FROM MOVING MUCH 
WEDNESDAY MORNING THEN FRONT MOVES SOUTHEAST INTO IL/NRN MO BY 00Z 
THURSDAY.  WILL TAPER POPS OFF NORTH AFTER WEDNESDAY MORNING AND 
KEEP AT LEAST LIKELYS GOING SOUTH FOR RAIN/TSRA. THURSDAY NIGHT 
FRONT LIFTS BACK NORTH IN RESPONSE TO STRONG S/W LIFTING OUT OF S.W. 
TROUGH.  BY 12Z AVN PLACES FRONT OVER NW CORNER OF CWA.  THE ETA IS 
NOT QUITE AS AGRESSIVE PLACING FRONT NEAR A CID/DBQ LINE BY EARLY 
FRIDAY.  AVN HAS BEEN THE PREFFERED MODEL ALL ALONG AND WILL TREND 
TOWARD THE AVN SOLUTION FOR THURSDAY/FRIDAY. AVN MOVES SURFACE LOW 
RAPIDLY NORTHEAST FRIDAY WITH COLD FRONT MOVING EAST OF CWA BY 00Z 
SATURDAY.

TEMPS THROUGH THE PERIOD WILL BE A HEADACHE WITH STRONG BAROCLINIC 
ZONE WAFFLING OVER CWA NEXT FEW DAYS.  AGAIN AVN IS THE PREFERRED 
MODEL ...SO WILL STAY CLOSE TO THE MAV NUMBERS.

.EXTENDED...SATURDAY THROUGH TUESDAY
S/W ENERGY MOVING OUT OF WESTERN U.S. WILL PROVIDE ANOTHER CHANCE OF 
RAIN FOR SUNDAY.  TIMING WILL BE AN ISSUE WITH MRF/CANADIAN 
SUGGESTING SURFACE LOW WILL MOVE THROUGH REGION EARLY SUNDAY...BUT 
UKMET IS CONSIDERABLY SLOWER WITH SURFACE TROF OVER THE FRONT RANGE 
AT 12Z SUNDAY. 12Z AVN IS ALSO SHOWING SYSTEM DIGGING AND CLOSING 
OFF OVER SOUTHERN ROCKIES SUNDAY...WHICH ALSO LENDS SUPPORT FOR 
SLOWER SOLUTIONS. FOR NOW WILL GO WITH A BLEND AND INTRODUCE SHRA 
FOR SUNDAY.  SINCE THERE IS SOME CONSIDERABLE DIFFERENCES IN TIMING 
WITH THIS SYSTEM...WILL STAY A LITTLE ABOVE MEX  NUMBERS FOR MONDAY.



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