[LeArc] Forecast Discussion : MLI@ 6/2/2002 3:13:08 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 022008
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
308 PM CDT SUN JUN 2 2002

UPPER RIDGE WAS OVER CENTRAL CONUS AT 12Z WITH TROUGHS MOVING INTO 
NORTHERN ROCKIES AND OVER NEW ENGLAND. AT SURFACE STATIONARY FRONT 
EXTENDED FROM CYCLONE IN NW KS ACROSS SE NEB INTO SW IA AND THEN 
ALONG IA/MO BORDER IN CWFA INTO S CENTRAL IL AT 18Z. VERY UNSTABLE 
AIR TO THE SOUTH OF FRONT WAS CAPPED IN SW IA BY H7 TEMPERATURES 
ABOVE 13 C...WHILE LITTLE TO NO CAP INDICATED OVER IA/IL 
ZONES...BUT LOW LEVELS STABILIZED BY MCS THAT MOVED THROUGH THIS 
MORNING WITH CONSIDERABLE MID LEVEL CLOUD COVER LINGERING AND 
KEEPING TEMPERATURES DOWN. FORECAST CHALLENGES CONTINUE TO CENTER ON 
SEVERE AND HEAVY RAIN POTENTIAL OVER NEXT 2 DAYS UNTIL HIGH PLAINS 
LOW AND LINGERING FRONT PUSH EAST. 

H5 SHORTWAVE THAT ACCOMPANIED THIS MORNINGS MCS WAS NOW OVER SRN WI 
WITH NEXT UPSTREAM WEAK WAVE MOVING INTO SE SD. ANOTHER WAVE SEEN ON 
WV IMAGERY OVER MOVING INTO SE WY MAY BE OF MORE CONSEQUENCE. ALL 
MODELS SIMILAR WITH LARGE SCALE FEATURES...BUT MAY NOT HAVE 
INITIALIZED H85 DEWPOINTS IN EASTERN NEB. QPF PLACEMENT WAS TOO FAR 
N THIS MORNING. GENERALLY FOLLOWED AVN/ETA COMPROMISE IN NEAR 
TERM...WITH SOME SOUTHWARD ADJUSTMENTS TO HIGHER QPF. 

SHORTWAVE MOVING INTO NW IA THIS AFTERNOON SHOULD HELP TRIGGER 
CONVECTION IN W-NW IA AS CONVECTIVE TEMPERATURE OVERCOMES CAP THAT 
WILL BE WEAKEST ALONG FRONT. CORFIDI VECTORS AND THICKNESS PATTERN 
SUGGESTS MCS WILL MOVE SE ALONG BAROCLINIC ZONE INTO CWFA THIS 
EVENING AND WILL CARRY LIKELY POPS. WITH SPC MODERATE SEVERE RISK 
GOING DUE TO MORE FAVORABLE SHEAR AND STRONGER LOW LEVEL JET 
DEVELOPING TONIGHT...WILL PLACE SEVERE WORDING IN ZONES. HAD 
ADDITIONAL 1 TO 1.5 INCHES NW OF FFL TO IOW LINE TODAY...WHICH IS AN 
AREA THAT HAS BEEN HIT SEVERAL TIMES THIS PAST WEEK. SURFACE 
DEWPOINTS IN 70S SOUTH OF FRONT...H85 DEWPOINTS ABOVE 16 JUST TO 
SOUTH AND HIGH PREC WATER INDICATE ABUNDANT MOISTURE FOR HEAVY 
RAINFALL. WITH TONIGHTS MCS LIKELY MOVING OVER THIS SAME AREA AND 
POSSIBLY ANOTHER THERE OR JUST NORTH MONDAY...WILL GO AHEAD AND 
HOIST FLOOD WATCH FOR TONIGHT FOR E CENTRAL IA ZONES...MAINLY 
BETWEEN HIGHWAYS 30 AND 34. 

SURFACE FRONT LINGERS JUST TO SOUTH OR INTO SOUTHERN ZONES MONDAY 
AND TUESDAY AND WILL CONTINUE WITH HIGH SCATTERED TO LIKELY POPS. 
HEAVY RAIN POTENTIAL MAY BE MORE PROBLEMATIC MONDAY NIGHT INTO 
TUESDAY AS LOW APPROACHES. TEMPERATURES WILL CONTINUE TO BE 
TRICKY...WITH CLOUDS AND COOL EASTERLY WINDS IN FAR NORTH LIMITING 
HIGHS TO 60S MONDAY WITH MID 80S ON OTHER SIDE OF FRONT IN FAR 
SOUTH. OVERALL...WILL NOT STRAY TOO FAR FROM GUIDANCE 
TEMPERATURES...EXCEPT TO TWEAK THESE N AND S EXTREMES. SURFACE 
CYCLONE MOVES THROUGH TUESDAY NIGHT...FOLLOWED BY H5 SHORTWAVE LATE 
WED TO FINALLY SHUT OFF RAIN CHANCES. 

IN EXTENDED...MEDIUM RANGE GUIDANCE CONTINUES TO PUSH LONG WAVE H5 
TROUGH AXIS TO EAST EARLY THURSDAY. BIG DIFFERENCES BETWEEN 
MRF AND UK WITH H5 WAVES TOWARD WEEKEND...BUT WILL GO WITH MRF ECMWF 
CONSENSUS WITH SURFACE HIGH FRIDAY MORNING AND THEN RETURN FLOW INTO 
SATURDAY. COULD BE CHANCE OF RAIN SUNDAY AS MRF TRIES TO DEVELOP REX 
BLOCK TO EAST WITH SURFACE TROUGH IN VICINITY...BUT NOT ENOUGH 
CONFIDENCE YET TO INTRODUCE POPS. DID NOT STRAY FAR FROM MOS 
NUMBERS...EXCEPT WENT A LITTLE ABOVE FOR LATE FRIDAY INTO SATURDAY 
WARMUP. 

COORD WITH DMX...THANKS.

.DVN...
IA...FLOOD WATCH TONIGHT EAST CENTRAL.
IL...NONE.
MO...NONE.

DLS