[LeArc] Forecast Discussion : MLI@ 3/20/03 2:43:01 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 202039
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
238 PM CST THU MAR 20 2003

SURFACE WEATHER MAP SHOWS LOW PRESSURE OVER SOUTHERN MISSOURI WITH
STATIONARY FRONT EXTENDING NORTHWARD FROM IT INTO WESTERN WISCONSIN
AND NORTHEAST MINNESOTA. A COLD FRONT EXTENDED SOUTH OF IT INTO
EASTERN ARKANSAS. TEMPERATURES OUT AHEAD OF THE FRONT WERE
GENERALLY IN THE 60S AND 70S...WITH SOME 40S AND 50S NOTED
IMMEDIATELY EAST OF THE FRONT IN OUR CWA. DEWPOINTS AHEAD OF IT WERE
IN THE 40S AND 50S. KDVN RADAR INDICATES SCATTERED SHOWERS OVER THE
CWA...WITH A LINE OF PRECIPITATION EXTENDING FROM KEOSAUQUA TO THE
QUAD CITIES THEN NORTHEAST TO FREEPORT.

UPPER AIR CHARTS SHOW AND UPPER LEVEL LOW OVER THE SOUTHWEST
MISSOURI AREA. A TROF EXTENDS NORTHEAST AND SOUTHWEST FROM THE LOW.
A SHORTWAVE AT 500 MB WAS TRAVERSING THE EXTREME NORTHERN U.S.
HIGHEST WIND SPEEDS WERE SOUTH AND EAST OF THE TROF. PRESSURE FALLS
WERE NORTHEAST OF THE LOW AND PRESSURE RISES WERE SOUTHWEST OF IT.
THESE FEATURES SUGGEST THE LOW WILL BEGIN LIFTING NORTHEAST.


FORECAST CHALLENGES INCLUDE PRECIPITATION CHANCES TOMORROW.


SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...

SURFACE LOW OVER SOUTHERN MISSOURI LIFTS NORTHEAST TONIGHT TAKING
THE FRONT DRAPED NORTH TO SOUTH ACROSS THE CENTRAL PORTION OF OUR
CWA WITH IT. UPPER LEVEL LOW PHASES WITH SHORTWAVE MOVING ACROSS THE
EXTREME NORTHERN U.S. AND BECOMES A SHORTWAVE ITSELF BEFORE LIFTING
NORTHEAST. SHORTWAVE MOVING ACROSS THE EXTREME NORTHERN U.S.
INTENSIFIES INTO A CUTOFF LOW AND MOVES ACROSS THE NORTHERN CWA
FRIDAY AFTERNOON. LOW THEN LIFTS NORTHEAST TAKING THE SURFACE LOW
WITH IT FRIDAY NIGHT INTO SATURDAY.

THERE WILL BE A CHANCE OF SHOWERS TOMORROW AFTERNOON WITH THE UPPER
LEVEL LOW AND PVA OVER THE AREA. BEST CHANCES FOR RAIN WILL BE
TOWARD THE NORTH WHERE THE PVA WILL BE THE GREATEST. RAIN SHOWERS
WILL DIMINISH TOMORROW NIGHT THEN SNOW FLURRIES WILL BE POSSIBLE
OVER NIGHT AS WE WILL REMAIN IN PVA AND CYCLONIC CURVATURE BEHIND
THE LOW. SATURDAY LOOKS PRECIP-FREE WITH CLOUD COVER DECREASING
FROM THE WEST AS THE UPPER LEVEL LOW MOVES NORTHEAST.


EXTENDED (SUNDAY THROUGH THURSDAY)...

AN ACTIVE PERIOD WITH THREE SYSTEMS MOVING THROUGH OUR CWA. MODELS
DIFFER ON TIMING OF THEM. GENERALLY...THE EUROPEAN IS FASTEST AND
THE UKMET THE SLOWEST. WILL LEAN TOWARD THE MIDDLE OF THE ROAD MRF.
GOING EXTENDED HAS A GOOD HANDLE ON THE EXTENDED SO WILL NOT
CHANGE. THURSDAY LOOKS DRY AS A SIGNIFICANT SYSTEM DEVELOPS OVER THE
UTAH/COLORADO AREA. EXPECT PCPN ASSOCIATED WITH THIS SYSTEM TO HOLD
OFF FROM REACHING THE CWA UNTIL FRIDAY.


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

$$

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