[LeArc] Forecast Discussion : MLI@ 2/3/03 5:31:20 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 031140
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
540 AM CST MON FEB 3 2003

SYNOPTIC PICTURE THIS MORNING SHOWS 500MB RIDGE OVER EASTERN HALF OF
THE U.S...WITH A FULL LATITUDE TROF COMING OUT OF THE ROCKIES INTO
THE HIGH PLAINS. AT THE JET LEVEL...DOUBLE 110KT JETS ARE OVER
SOUTHEAST NEBRASKA AND NEW MEXICO. AT THE SURFACE...A LOW IS OVER
NORTHEAST MISSOURI...WITH A WARM FRONT EXTENDING TO NEAR CHICAGO.
TO THE NORTH OF THE FORECAST AREA...PRECIP ACROSS NORTHERN WISCONSIN
IS ASSOCIATED WITH THE 850MB WARM FRONT...WHILE PRECIP ACROSS
CENTRAL AND EASTERN NEBRASKA AND WESTERN KANSAS IS ASSOCIATED WITH
THE 500MB TROF.

THE PRIMARY FORECAST CONCERNS THIS PACKAGE ARE IN THE SHORT TERM...
WITH SNOW LIKELY ACROSS THE NORTHWEST HALF OF THE FORECAST AREA
THIS AFTERNOON AND TONIGHT...AND HIGH WINDS ACROSS THE FORECAST AREA
TONIGHT.  MAIN THEME THRU THE NEXT 7 DAYS IS A RETURN TO WINTER...
WITH TEMPERATURES A GOOD 10 DEGREES OR MORE BELOW NORMAL.

THE MODELS INITIALIZED MODERATELY WELL..EXCEPT A LITTLE WEAK ON THE
DEPTH OF THE SURFACE LOW.  BOTH THE AVN AND ETA HANDLED QPF THRU
06Z FAIRLY WELL.  THE MODELS BRING THE SURFACE LOW THROUGH THE
SOUTHEAST CORNER OF THE FORECAST AREA TODAY...INTO SOUTHERN
MICHIGAN TONIGHT...WITH RAPID DEEPENING.  1000-850MB THICKNESS DROP
BELOW 1310 THIS MORNING ACROSS NORTHWEST PORTIONS OF THE FORECAST
AREA AND THIS AFTERNOON SOUTHEAST...WITH 1000-500MB THICKNESSES
DROPPING BELOW 540 AFTER 18Z NORTHWEST AND AROUND 00Z SOUTHEAST.
PRIMARY AREA FOR PRECIPITATION WILL BE NORTHWEST...IN THE
DEFORMATION ZONE...WHICH IS ALSO WHERE STRONGEST 700MB VV'S WILL BE.
LIMITED JET COUPLING WILL PRODUCE SOME UPPER DIVERGENCE THIS
AFTERNOON AND EVENING.  THE DEFORMATION SNOW WILL PULL EAST OF THE
AREA THIS EVENING...WITH FLURRIES LINGERING THRU THE REMAINDER OF
THE NIGHT.  THE NORTHWEST CORNER OF THE FORECAST AREA SHOULD SEE 2
TO 3 INCHES OF SNOW...WITH 1 TO 2 INCHES ACROSS THE NORTHWEST THIRD
TO HALF OF THE FORECAST AREA...AND AN INCH OR LESS SOUTH AND EAST.
BLOWING AND DRIFTING SNOW WILL BE A PROBLEM THIS EVENING IN
NORTH AND WEST AREAS.

WINDS WILL INCREASE THIS AFTERNOON AS THE LOW PULLS EAST. AN
IMPRESSIVE PACKING OF SURFACE ISOBARS WILL ALIGN WITH 850MB WINDS
BY 21Z WEST...AND BY 00Z CENTRAL AND EAST...PRODUCING SUSTAINED
WINDS IN THE 25 TO 35 MPH RANGE THRU THE NIGHT.  WINDS WILL STILL BE
HIGH IN THE MORNING NORTHEAST...AND BREEZY ACROSS THE FORECAST AREA
FOR THE DAY.

DID NOT MAKE MANY CHANGES TO THE REMAINDER OF FORECAST AS STILL ON
TRACK...OTHER THAN MINOR TEMPERATURE TWEAKS.  STILL LOOKS LIKE
A REINFORCING COLD FRONT WEDNESDAY NIGHT...WITH A STRONG 500MB TROF
ROTATING THRU THE AREA THURSDAY NIGHT OR FRIDAY.  ANOTHER COLD
FRONT SHOULD MOVE THRU IN THE SATURDAY NIGHT/SUNDAY TIME FRAME.


.DVN...
IA...WINTER WEATHER ADVISORY THIS AFTERNOON AND TONIGHT NEAR AND
NORTHWEST OF A LINE FROM FAIRFIELD TO IOWA CITY TO MAQUOKETA TO
DUBUQUE...AND A WIND ADVISORY FOR TONIGHT FOR THE REMAINDER OF IOWA
COUNTIES.
IL...WINTER WEATHER ADVISORY THIS AFTERNOON AND TONIGHT FOR
JO DAVIESS COUNTY...AND A WIND ADVISORY FOR TONIGHT FOR ALL OTHER
ILLINOIS COUNTIES.
MO...WIND ADVISORY TONIGHT.

$$
REA