[LeArc] Forecast Discussion : MLI@ 11/3/02 2:25:59 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 032035
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
235 PM CST SUN NOV 3 2002

ACTIVE UA PATTERN THIS AFTERNOON OVER THE CENTRAL U.S.  S/W ENERGY
IS DROPPING SOUTHEAST ACROSS NRN GREAT LAKES WHILE SOUTHERN STREAM
S/W IS SHEARING OUT ACROSS NRN KS/MO.  MOST OF THE SIG PCPN
ASSOCIATED WITH SRN STREAM SYSTEM IS NO OVER ERN IL/WRN IN WITH
JUST SOME VIRGA STRETCHED OUT NORTH OF THE VORT TRACK OVER SRN
IA/NRN MO.  COLD FRONT ASSOCIATED WITH NRN STREAM TROF WAS JUST
ENTERING NW IA EARLY THIS AFTERNOON...WITH COLD AIR SC MOVING INTO
W CENTRAL MN/E CNTRL SD.

MODELS ARE IN GOOD AGREEMENT THROUGH MONDAY AS THE DAMPEN OUT THE
PLAINS SYSTEM THIS EVENING AS MOVES INTO NW FLOW REGIME AS GREAT
LAKES SYSTEM MOVES ESE.  WEAK UPPER RIDGE BUILDS IN MONDAY AS
SURFACE RIDGE SETS ALONG THE MS RIVER BY MONDAY AFTERNOON.
DISCREPANCIES SHOW UP WITH SYSTEM MOVING OUT OF NORHTERN ROCKIES
LATE MONDAY INTO TUESDAY. GFS AGAIN IS FASTER THAN THE ETA MOVING
THIS S/W THROUGH IA BY 06Z WED WHILE ETA IS ABOUT 6 HOURS SLOWER.
IN THIS FAST FLOW REGIME...THE GFS IS THE PREFERED MODEL.

MAIN CONCERN IN THE NEAR TERM WILL BE CLOUD TRENDS TONIGHT.  CLOUDS
ASSOCIATED WITH SRN STREAM SYSTEM HAVE CLEARED NW/N CNTRL IA BY MID
DAY.  SOME ADDITIONAL DEVELOPEMENT ON BACKSIDE OF CLOUD SHIELD OVER
NE IA WILL DELAY CLEARING SOME...BUT BASED ON DISTANCE SPEED TOOL...
NW PART OF CWA SHOULD BREAK OUT BY EARLY EVENING. MODEL  RH PROGS
SUPPORT CLEARING IN SERN SECTIONS EARLY MONDAY MORNING.  SC
FIELD MOVING SE THROUGH MN THIS AFTERNOON IS OF SOME CONCERN FOR
NORHTERN CWA LATER TONIGHT. HOWEVER MODELS SUGGEST THESE CLOUDS WILL
STAY TO OUR N. ALSO THESE CLOUDS SHOULD ENCOUNTER MORE SUBSIDENCE
BEHIND SRN STREAM S/W AS THEY APPROACH NORTHERN IA.  VIRGA OVER SRN
IA/NRN MO COULD PRODUCE A FEW SPRINKLES THIS EVENING.  TEMPS TONIGHT
WILL BE DEPENDENT ON CLEARING AND SURFACE WINDS.  NW COUNTIES SHOULD
COOL THE MOST WITH CLEARING SKIES THIS EVENING AND SFC RIDGE GETTING
CLOSE ENOUGH BY EARLY MORNING TO ALLOW WINDS TO DECOUPLE.  WILL GO
CLOSE TO COLDER MET NUMBERS IN THE NW AND FAVOR MILDER FWC/MAV IN THE
EAST. HIGH PRESSURE SLIDES ACROSS REGION MONDAY. LIGHT WINDS
ASSOCIATED WITH HIGH WILL LIMIT MIXING DEPTH SO WILL USE A MAV/FWC
COMPROMISE WITH MET NUMBERS LOOKING TOO WARM.

NEXT SYSTEM TO MOVE INTO REGION ON TUESDAY.  AVN SHOWING POSITIVE
UVV'S BY LATE MONDAY NIGHT...HOWEVER MOISTURE WILL BE LIMITED.
BEST THREAT FOR PCPN WILL BE DURING THE DAY TUESDAY AS SURFACE AND
UPPER SYSTEM FORCING PHASE.  STILL MOISTURE WILL REMAINED LIMITED
AND ONLY EXPECT A LIGHT PCPN EVENT.  GFS SUGGESTS AIR ACROSS NRN CWA
COULD SUPPORT SOME SNOW MIXED IN WITH LIGHT RAIN...WHILE ALL RAIN
EXPECTED IN THE SOUTH.  SO NO CHANGE FROM CURRENT PACKAGE.  GFS
MOVES PCPN EAST OF REGION BY TUESDAY EVENING.  CLEARING EXPECTED
TUESDAY NIGHT AS HIGH PRESSURE RIDGE MOVES THROUGH EARLY WEDNESDAY.

LONG RANGE MODELS CONTINUE TO SHOW NORTHWEST FLOW TRANSITIONING
TO A MORE ZONE FLOW DURING PERIOD.  LAST SHOT OF COLD AIR SWEEPS
RAPIDLY THROUGH THE REGION THURSDAY WITH DRY COLD FRONT MOVING
THROUGH DURING THE EARLY MORNING. ENERGY MOVING INTO PACIFIC COAST
FRIDAY HELPS BREAKDOWN NW FLOW OVER THE CENTRAL/NORTHERN PLAINS
AND SETS UP A STRONG RETURN FLOW OVER REGION BY EARLY FRIDAY.  GFS
THEN EJECTS A COUPLE OF S/W'S OUT OF THE SW AND INTO THE SOUTHERN
PLAINS AND MID MISSISSIPPI VALLEY OVER THE WEEKEND.  THE SECOND
SYSTEM LOOKS QUITE OMINOUS FOR LATE SUNDAY INTO MONDAY.  HOWEVER...
GFS IS SUGGESTING RAIN WITH COLD AIR WELL TO THE NORTH OF REGION.
FOR THE EXTENDED...WIL CONTINUE WITH DRY WX THURSDAY AND FRIDAY AND
CHANCE POPS FOR RAIN SATURDAY/SUNDAY.  TEMPS WILL BE MODERATING
THROUGH THE PERIOD.


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