[LeArc] Forecast Discussion : MLI@ 11/2/02 1:41:30 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 021951
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
151 PM CST SAT NOV 2 2002

HIGH PRESSURE CENTERED OVER NORTHERN ARKANSAS/SOUTHERN
MISSOURI WITH RIDGE EXTENDING NW THROUGH WRN IA/ERN NE
AT 18Z.  UPPER LOW OVER SERN ID AT 12Z IS STARTING ITS
MOVE EAST...PER WATER VAPOR LOOP. ALSO EVIDENT ON WATER VAPOR
IMAGERY IS S/W MOVING OUT OF WRN CANADA. IR IMAGES SHOWING
EXTENSIVE CLOUD COVER FROM THE LOWER MS VALLEY NORTH INTO THE HIGH
PLAINS.

MAIN CONCERN THIS ISSUANCE WILL BE PCPN THREAT/TYPE FOR SUNDAY AND
AGAIN ON TUESDAY.  MODELS ARE IN GOOD AGREEMENT MOVING ID H5 LOW
EAST AND DAMPENING IT OUT AS IT MERGES WITH H5 CYCLONIC FLOW OVER
IOWA SUNDAY.  MODELS ALL GENERATE MAINLY LIGHT QPF DURING THE DAY
SUNDAY...WITH ETA/MESO ETA HIGH-LIGHTING NARROW BAND OF HIGHER QPF
JUST NORTH OF THE H5 LOW TRACK.  AVN ALSO HINTING AT THIS AND LOOKS
REASONABLE.  LOW LEVEL TEMPS WILL BE MARGINAL FOR SNOW.  BEST
THREAT FOR SNOW WILL BE ACROSS THE NORTHERN THIRD AND WILL DEPEND ON
HOW MUCH TEMPS RECOVER BEFORE PCPN STARTS BY MID MORNING.  WILL
GO WITH A RAIN SNOW MIX NORTH AND ALL RAIN SOUTH.  TEMPERATURE
FORECAST TONIGHT WILL BE COMPLICATED BY CLOUD SHIELD SPREADING NE AND
DIMINISHING WINDS AS SURFACE RIDGE SLIDES TO THE SOUTHEAST.  MID/HI
CLOUD SHIELD COVERING MOST OF THE SW HALF OF IA AT 18Z.  EXPECT NE
PROGRESSION TO SLOW THIS EVENING AS CLOUD SHIELD ENCOUNTERS NWLY
FLOW.  SO...NERN COUNTIES SHOULD HAVE CLEAR SKIES FOR A GOOD PART OF
THE EVENING ALLOWING TEMPS TO DROP RAPIDLY.  WILL GO CLOSE TO COLDER
MET NUMBERS IN THE NE TONIGHT AND FAVOR  MILDER FWC NUMBER IN THE
SOUTH.  SOUTHERLY FLOW AHEAD OF SURFACE FRONT WILL DRIVE TEMP
RECOVERY ON SUNDAY.  MAV/MET NUMBERS LOOK REASONABLE AND ARE IN
LINE WITH GOING FORECAST.  PCPN SHOULD BE OUT CWA BY SUNDAY EVENING
WITH MODELS INDICATING GOOD DRYING BEHIND SYSTEM.

NEXT SYSTEM TO MOVE THROUGH TUESDAY.  AGAIN PCPN SHOULD BE LIGHT
WITH PCPN TYPE STILL A PROBLEM WITH MARGINAL H8 TEMPS.  ALTHOUGH
AVN IS SUGGESTING SLIGHTLY COLDER TEMPS WILL BE IN PLACE COMPARED TO
TOMORROWS EVENT. SO WILL GO WITH A R/S MIX WORDING IN THE NORTH.


EXTENDED (WED-SAT)
TEMPS WILL BE MODERATING FOR THE END OF THE WEEK AS H5 FLOW DE-
AMPLIFIES OVER THE NRN HALF OF THE COUNTRY.  BY SATURDAY
STRONG SURFACE LOW MOVING INTO S CENTTRAL CANADA DRAGS A COLD
FRONT THROUGH THE PLAINS.  STRONG SOUTHERLY FLOW DEVELOPING AHEAD OF
THE FRONT SHOULD PUSH TEMPS ABOVE NORMAL.  WILL ADJUST MEX NUMBERS
UP ABOUT A CATEGORY FOR SATURDAY.

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