[LeArc] Forecast Discussion : MLI@ 3/12/03 4:57:04 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 121105
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
505 AM CST WED MAR 12 2003

SYNOPTIC PICTURE THIS MORNING SHOWS A COLD FRONT EXTENDING FROM A
SOUTHEAST ONTARIO LOW THROUGH THE CENTRAL PORTION OF THE FORECAST
AREA...AND SOUTHWEST TO A WESTERN KANSAS LOW.  THE FRONT IS
MAKING SLOW PROGRESS ACROSS THE FORECAST AREA DUE TO LACK OF STEERING
WINDS AT 850MB.  A LARGE HIGH EXTENDS FROM SASKATCHEWAN INTO THE
THE DAKOTAS.  AT 500MB...FLOW IS NEARLY ZONAL ACROSS THE COUNTRY.
AT 300MB A 120KT JET EXTENDS ACROSS THE DAKOTAS.  PRECIP AHEAD OF
THIS JET COVERS MUCH OF SOUTHERN MINNESOTA.

THE PRIMARY FORECAST CHALLENGE THIS MORNING IS PRECIP ASSOCIATED
WITH THE COLD FRONT...WHICH WILL BE STALLING OUT AND AFFECTING THIS
AREA THROUGH MIDNIGHT TONIGHT.  ALSO OF INTEREST ARE A SHORT WAVE
SATURDAY NIGHT AND SUNDAY...AND A POTENTIAL LOW MOVING OUT OF THE
SOUTHERN PLAINS TUESDAY.

THE SHORT-TERM MODELS HAVE COME INTO AGREEMENT ON THE COLD FRONT...
STALLING IT SOUTH OF THE FORECAST AREA ACROSS NORTHERN MISSOURI BY
18Z. RAIN WILL BE POSSIBLE THIS MORNING ACROSS NORTHERN PORTIONS OF
THE FORECAST AREA...JUST NORTH OF THE 850MB FRONT POSITION...AS IT
SINKS SOUTH ACROSS THE AREA.  VV'S AND 300MB DIVERGENCE INCREASE
DURING THE DAY...MAXING OUT AROUND 00Z THIS EVENING...ESPECIALLY
JUST SOUTH OF THE FORECAST AREA.  THEREFORE...RAIN WILL BE POSSIBLE
ACROSS THE AREA THIS AFTERNOON...ALTHO THE HEAVIEST RAIN COULD BE
SOUTH OF THE AREA...ROBBING OUR AREA OF ENUF MOISTURE FOR ANY
SIGNIFICANT RAINFALL.  DYNAMICS WILL CONTINUE TO BE STRONG INTO THE
EVENING...AS THE KANSAS LOW BEGINS TO MOVE EAST ALONG THE
STATIONARY FRONT.  THE LOW MOVES JUST NORTH OF STL AROUND 06Z
TONIGHT...WITH HIGH PRESSURE BUILDING IN FROM THE NORTH.  THURSDAY
WILL BE A LITTLE COOLER THAN EXPECTED PREVIOUSLY DUE TO A LIGHT
FETCH OF LAKE MICHIGAN.  HOWEVER...WINDS MAY BE LIGHT ENUF THAT
LAKE INFLUENCE MAY BE QUITE MINIMAL.

LOOKING FURTHER AHEAD...WARM AIR ADVECTION WILL SET UP THURSDAY NIGHT
AS THE HIGH SHIFTS EAST.  THIS WILL CONTINUE INTO SATURDAY...
BRINGING MUCH WARMER AIR INTO THE REGION.  A SHORT WAVE WILL BRUSH
THROUGH OUR NORTH SATURDAY NIGHT...THEN SLOW UP AND LAY A
BAROCLINIC ZONE ACROSS OUR AREA SUNDAY AND MONDAY...WITH A WARM
FRONT POSSIBLY DEVELOPING ACROSS NORTHERN MISSOURI...AND A DEEP LOW
MOVING OUT OF THE SOUTHERN PLAINS TUESDAY TO JUST WEST OF THE
FORECAST AREA. THIS WILL BRING AN EXTENDED PERIOD OF PRECIP
CHANCES...WITH THUNDERSTORMS POSSIBLE DUE TO THE WARMER TEMPS.  WE
AREA GETTING INTO THE SEASON...AND WILL HAVE THE SYNOPTIC PATTERN
AND THE TEMPERATURES...WHERE LOW TOP SEVERE THUNDERSTORMS WILL BE
POSSIBLE SOMETIME BETWEEN SUNDAY AND TUESDAY.

WILL MAKE FEW CHANGES TO THE ONGOING FORECAST...EXCEPT FOR MINOR
TEMP ADJUSTMENTS AND INTRODUCTION OF THUNDER IN THE EXTENDED.


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

$$

REA