[LeArc] Forecast Discussion : MLI@ 11/20/02 3:06:17 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 202119
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
318 PM CST WED NOV 20 2002

ONE SHORT WAVE TROUGH IS EXITING THE AREA WITH A SURFACE COLD
FRONT TO PASS THROUGH THE CWA TONIGHT...WHILE ANOTHER WAVE IS
TAKING SHAPE ALONG THE CANADIAN-U.S. BORDER.  LATEST RUC AND MSAS
ANALYSES INDICATE 850MB WARM ADVECTION...A NICE SURFACE PRESSURE
RISE/FALL COUPLET AND UPPER LEVEL JET SUPPORT WITH THE CANADIAN
SYSTEM.  RADAR SIGNATURES IN ND APPEAR TO BE MID-LEVEL CLOUDS RATHER
THAN PRECIP AT THIS TIME.

MAIN CONCERN IS THE CANADIAN SYSTEM TOMORROW AND ANOTHER UPPER LEVEL
WAVE/SURFACE COLD FRONT LATE SATURDAY.

12Z MODELS GENERALLY AGREE IN BRINGING THE TROUGH THROUGH THE CWA
DURING THE DAY TOMORROW WITH THE STRONGEST FORCING OVER AND JUST
EAST OF THE CWA.  WILL MAINTAIN LIKELY POPS IN THE EASTERN 2/3RDS OF
THE CWA AND CHANCE POPS IN THE WEST.  INTERESTINGLY...THE 18Z ETA
IS DOING THE FLIP FLOP AND BACKING OFF THE QPF COMPARED TO THE 12Z
ETA AND GFS.  GIVEN THE UPPER LEVEL SUPPORT...AVAILABILITY OF MODEST
MOISTURE AND THE PROGGED DEVELOPMENT OF SURFACE LOW IN RESPONSE TO
THE UPPER LEVEL FORCING...SOME SPOTS MAY SEE AROUND 1 INCH OF
ACCUMULATION.

THE NEXT SHORT WAVE TROUGH FOR THE LATTER PART OF SATURDAY LOOKS LESS
IMPRESSIVE THOUGH STILL WORTH CHANCE POPS.  WENT ABOVE GUIDANCE
TEMPS ON SATURDAY AHEAD OF THE SYSTEM.  PASSAGE OF THIS TROUGH WILL
BRING MUCH COOLER AIR INTO THE REGION THROUGH EARLY WEEK...WITH
TUESDAY LOOKING TO BE THE COLDEST DAY AS WE SIT UNDER SURFACE HIGH
PRESSURE. EXTENDED MODELS GENERALLY AGREE IN A WARMING TREND AROUND
MID WEEK...AND LITTLE CHANCE OF SIGNIFICANT PRECIP BEYOND TOMORROW.

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

WOLF