[LeArc] Forecast Discussion : MLI@ 2/2/03 5:33:36 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 021143
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
543 AM CST SUN FEB 2 2003

RUNNING WAY BEHIND DUE TO AWIPS/IPFS BEING VERY SLOW FOR UNKNOWN
REASONS.

BRIEFLY AND BLUNTLY...THE MODELS DON/T HAVE A CLUE WHAT IS GOING
ON. THEY ARE NOT HANDLING CURRENT PRECIP NORTH OR WEST OF CWFA AT
ALL. BOUNDARY SETTING UP JUST SOUTH OF CWFA AND LOOKS LIKE IT WILL
NOT MAKE IT INTO THE CWFA...AS WINDS CONTINUE TO BACK AND BECOME MORE
AND MORE EASTERLY. ALL MODELS SHOW IMPRESSIVE LIFT MOVING EAST INTO
THE CWFA THIS AFTERNOON AND ALL ARE DRY. NOT A CHANCE. GOOD
ISENTROPIC LIFT AND A BOUNDARY WITH WAA MEANS PRECIP. FOG HASN/T
GOTTEN TOO FAR OUT OF HAND THIS MORNING AND ONLY EXPECT LOCALLY
DENSE.

TONIGHT THROUGH MONDAY NIGHT THE FUN BEGINS. STRONG ISENTROPIC LIFT
THROUGH THE NIGHT AS STORM SYSTEM APPROACHES. HAVE BUMPED UP PRECIP
TO LIKELY CATEGORY WITH AVAILABLE MOISTURE/LIFT. INCONSISTENCIES
WITH THE MODELS BRING LOW TRACK INTO QUESTION. HOWEVER CONCEPTUALLY
THE MODELS HAVE BEEN SUGGESTING FOR SEVERAL RUNS OF HAVING TWO
SEPARATE LOWS MOVING THROUGH WITH THE SECOND LOW THE MAIN EVENT.
ADDITIONALLY THE TRACK OF THE SECOND LOW IS ROUGHLY ALONG A KMCI...
KUIN...TO SOUTH OF KCHI...OR JUST A LITTLE SOUTH OF THAT. ALL
MODELS HAVE BEEN HINTING AT THIS FOR AT LEAST 4 OR 5 RUNS NOW.

CAA WITH SYSTEM IMPRESSIVE...AND PRECIP SHOULD BE TURNING OVER TO
ALL SNOW IN ABOUT THE NORTHWEST QUARTER OF CWFA AROUND DAWN MONDAY.
CHANGE FROM RAIN TO SNOW WILL BE COMPLETE BY MID DAY. TAKING THE
MODELS APART REVEALS THE FOLLOWING. 700 TO 500 MB TEMPERATURES FALL
RIGHT INTO THE FAVORED DENDRITIC GROWTH AREA (-13 TO -17) OVER CWFA.
850 TO 500 OMEGA MAX IS OVER CWFA. RH IS AT LEAST 90 PERCENT
THROUGH MOST OF THE ATMOSPHERE. DESPITE WHAT OTHER MODEL FEATURES
ARE SAYING...THIS POINTS TO SNOW AND A LOT OF IT. CURRENTLY EXPECT A
BAND OF 6 TO 8 INCHES...POSSIBLY A LITTLE MORE...ROUGHLY ALONG A
LINE FROM ELDON IOWA TO STERLING ILLINOIS. AXIS POSSIBLY MAY SHIFT
ANOTHER 20 MILES TO THE NORTHWEST (ABOUT 1 COUNTY OR SO) WITH THE
12Z RUN AS THE SYSTEM EXITS THE ROCKIES. THEREFORE WILL RAISE
HEADLINES FOR WINTER STORM WATCH.

SNOW TO BE HEAVIEST MONDAY AFTERNOON AND EARLY EVENING WITH A
GRADUAL TAPERING TO FLURRIES LATE MONDAY NIGHT. WIND TO INCREASE LATE
MONDAY AND MONDAY NIGHT. PRESSURE GRADIENT OF 15 TO 20 MB ACROSS
IOWA SUGGEST MAX GUST POTENTIAL TO 40 MPH. WITH NEW SNOW...NEAR
ZERO VISIBILITIES LIKELY IN RURAL AREAS. WINDS TO START TAPERING OFF
LATE MONDAY NIGHT BUT WILL STILL BE BRISK ON TUESDAY.

NO CHANGES DONE TO EXTENDED DUE TO LACK OF TIME. TEMPERATURES
STARTING TUESDAY HIGHLY DEPENDENT ON HOW THE SNOW FIELD LAYS OUT.

.DVN...WINTER STORM WATCH MONDAY AND MONDAY NIGHT.
IA...IAZ040>042-051>054-063>068-076>078-087>089-098-099.
IL...ILZ001-002-007-009-015>018-024>026-034-035.
MO...MOZ009-010.

$$
SF