[LeArc] Forecast Discussion : MLI@ 12/2/02 2:49:23 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 020902
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
300 AM CST MON DEC 2 2002

STRONG NW FLOW STILL IN PLACE OVER CENTRAL U.S.  NEXT SURGE OF
ARTIC AIR POISED TO THE NORTH ACROSS MN/WI.  THE COLDER AIR IS
LAGGING THE SURFACE FRONT WHICH EXTENDS FROM SURFACE LOW OVER NERN
NE THROUGH NRN IA AND NRN IL AT 07Z.  BAND OF POST FRONTAL CLOUDS
ORIENTED NW-SE FROM ERN DAKOTAS THROUGH MN THROUGH WI.  REGIONAL
RADAR COMPOSITE SHOWS BAND OF SN ASSOCIATED WITH ENHANCED CLOUDS
FROM CNTRL MN ITNO SRN WI.  THE SN LINES UP WELL WITH RRQ OF H3 JET.
SN HAS BEEN INCREASING SINCE 06Z WITH A COUPLE OF SITES IN  CNTRL
AND SERN MN REPORTING VSBYS AT OR BELOW 1 MILE AT TIMES.

PRIMARY CONCERN WILL BE SN CHANCES/ACCUMULATION FOR TODAY.  MODELS
CONTINUE TO AGREE ON BROAD SCALE FEATURES THROUGH THE MIDDLE OF THE
WEEK.  THERE ARE WERE SOME DIFFERENCES NOTED BETWEEN THE ETA/GFS
WITH LOW LEVEL THERMAL AND MOISTURE FIELDS IN THE NEAR TERM.  BOTH
MODELS...BASED ON 2M TEMPS...WERE TOO AGRESSIVE WITH THE COLDER AIR
ACROSS NERN IA/NRN IL AND THE ETA APPEARS TO BE TO DRY IN THE LOW
LEVELS TODAY...ESPECIALLY IN LIGHT OF THE DEVELOPING PCPN TO OUR N.
THE GFS IS THE PREFERRED MODEL...SINCE IT APPEARS TO BE HANDLING THE
ELVOVING PCPN TO OUR N BETTER THAN THE ETA.

MODELS HAVE ONCE AGAIN BACKED OFF ON SNOW THREAT FOR CWA TODAY AS
THEY DID ON YESTERDAYS 00Z RUN.  ONE THING THAT HAS BEEN CONSISTENT
THE LAST SEVERAL RUNS IS THEY CONTINUE TO FOCUS THE HEAVIER PCPN TO
OUR NORTHEAST.  EVEN THOUGH THE GFS HAS PULLED BACK ON QPF FOR NERN
CWA TODAY...WILL CONTINUE WITH 1-2 INCH AMOUNTS FOR NW IL SINCE
GFS CONTINUES TO DEPICT GOOD UVVS THIS MORNING AS RRQ OF H3 JET
SWEEPS ACROSS NERN CWA BETWEEN 12Z AND 18Z.  FOR NW CWA AND ALONG I80
CORRIDOR WILL GO WITH LESS THAN AN INCH. LOOKS LIKE MOST OF THE PCPN
WILL END BY MIDDAY. DIFFICULT TEMP FORECAST TODAY WITH COLD AIR
MOVING THROUGH CWA.   CAA WILL LIKELY BE OFFSET OVER SRN
SECTIONS BY SOME SUNSHINE THIS MORNING. FAR SOUTHERN SECTIONS COULD
BOUNCE BACK INTO THE LOWER TO MIDDLE 40S BEFORE NOON.  CLOUDS AND
PCPN IN THE NORTH SHOULD KEEP TEMPS STEADY IN MID-UPPER 20S. WILL
WAIT UNTIL ISSUANCE TIME TO MAKE FINAL ADJUSTMENTS TO TODAYS TEMPS.
LOW LEVEL WINDS TURN TO THE NORTH...THEN NE BY TONIGHT AS COLD AIR
DEEPENS.  BOTH GFS/ETA DEPICTING SOME LAKE ENHANCED CLOUDS/PCPN
MOVING IN LATE TONIGHT WITH ETA BEING THE MOST AGREESSIVE.  THIS
LOOKS REASONABLE WITH LM STILL RELATIVELY WARM AND STRENGTH OF COLD
AIR MASS.  WILL GO WITH A LOW CHANCE POP IN THE ERN CWA FOR -SN AND
FLURRIES ELSEWHERE. THE EXPECTED CLOUD COVER LATE TONIGHT WILL IMPACT
MINS AND HAVE BUMPED TEMPS UP A NOTCH ESPECIALLY IN THE NE. NEXT SW
WILL MOVE THROUGH REGION ON WEDNESDAY.  MOISTURE WILL BE LIMITED AND
ONLY EXPECT FLURRIES.

NO CHANGES ANTICIPATED FOR THE EXTENDED. 00Z GFS/MRF SHOWS MORE OF
THE SAME THROUGH NEXT WEEKEND.

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

DLF