[LeArc] Forecast Discussion : MLI@ 11/25/02 1:59:25 AM

Mon, 25 Nov 2002 01:59:25 -0600

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

FXUS63 KDVN 250811
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
210 AM CST MON NOV 25 2002

SYNOPTIC PICTURE THIS MORNING SHOWS A 110KT JET AT 300MB OVER THE
NORTHERN GREAT LAKES...WITH DVN UNDER THE RIGHT REAR QUAD...WHICH IS
WHAT GAVE US OUR SNOW YESTERDAY. AT 500MB A BROAD TROF IS OVER THE
CENTRAL U.S...WITH A WEAK SHORT WAVE CURRENTLY OVER THE FORECAST
AREA.  TO THE NORTH...A STRONG SHORT WAVE IS HEADING SOUTH FROM
CENTRAL SASKATCHEWAN.  TO THE WEST...A RIDGE IS OVER THE WEST COAST.
AT THE SURFACE A LOW IS IN EASTERN KENTUCKY...WITH A 1035MB HIGH
BUILDING IN FROM THE CENTRAL PLAINS. THE CLOUD SHIELD ASSOCIATED WITH
OUR FIRST SNOWFALL HAS PULLED EAST...AS WRAP-AROUND APPROACHES FROM
NORTH CENTRAL IOWA. TEMPERATURES HAVE FALLEN LIKE A ROCK EARLY THIS
MORNING...WITH THE CLEAR SKIES...THIN SNOW COVER...AND LIGHT WINDS...
DOWN TO 12F SO FAR AT DVN.

THE PRIMARY FORECAST CONCERN IS A STRONG SHORT WAVE ON TUESDAY...
WHICH COULD BRING ANOTHER CHANCE OF SNOW TO THE AREA.

THE SHORT-TERM MODELS INITIALIZED WELL AT 500MB AND THE SURFACE AT
00Z. THEY AGREE QUITE WELL ON THE SASKATCHEWAN SHORT WAVE MOVING
THROUGH...OR JUST SOUTH OF THE FORECAST AREA ON TUESDAY...
ACCOMPANIED BY GOOD 300MB DIVERGENCE AND 700MB VV'S. THICKNESSES
COLD ENUF FOR ALL SNOW.  LOOKING FURTHER AHEAD A STRONG 140-150KT JET
MOVES ACROSS THE LOWER MISSISSIPPI AND TENNESSEE VALLEYS IN THE
WEDNESDAY-THURSDAY TIME FRAME.  ON THURSDAY...THE ETA BRINGS A 500H
SHORT WAVE OVER THE AREA...WITH A WEAK SURFACE PERTURBATION...AND A
100KT JET SEGMENT OUT OF THE NORTH.  THE AVN KEEPS THE UPPER WAVE
NORTH...BUT ALSO BRINGS ACROSS A SURFACE FEATURE.  NEW MRF GUIDANCE
DRY FOR THURSDAY.

WILL CONTINUE WITH CURRENT FORECAST FOR TUESDAY CHANCES...FAVORING
SOUTH.  WILL HAVE TO KEEP AN EYE ON...HOWEVER...AS A SLIGHT CHANGE
IN TRAJECTORY COULD CHANGE THE PICTURE SIGNIFICANTLY.  MAY REDUCE
MENTION OF PRECIP IN AT LEAST ONE DAY IN THE FRIDAY-SUNDAY PERIOD.
ALTHOUGH MRF...UK...AND EUROPEAN IN TYPICAL DISAGREEMENT...DON'T SEE
ENUF TO HIT ON TOO HARD ON PRECIP.

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

REA