[LeArc] Forecast Discussion : MLI@ 7/19/2003 5:08:22 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 192152
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
430 PM CDT SAT JUL 19 2003

SYNOPTIC PICTURE LATE THIS AFTERNOON SHOWS HIGH PRESSURE OVER THE
AREA...WITH A STATIONARY FRONT EXTENDING ACROSS SOUTHERN MISSOURI.
LOW DEW POINTS LINGER ACROSS MUCH OF THE FORECAST AREA...BUT HIGHER
DEW POINTS AROUND 70 ARE JUST SOUTH AND WEST.

THE PRIMARY FORECAST CONCERN OVER THE NEXT 7 DAYS IS IN THE SHORT
TERM...WITH THE POTENTIAL FOR SEVERE WEATHER ASSOCIATED WITH A COLD
FRONT MOVING THRU THE FORECAST AREA SUNDAY NIGHT.

THE MODELS AGREE FAIRLY WELL ON AN MCS LATE TONIGHT...MOVING THRU
SOUTHERN MINNESOTA AND SOUTH/CENTRAL WISCONSIN...WITH THE SOUTHERN
EDGE OF THE CONVECTION POSSIBLY MAKING IT INTO THE DVN FORECAST AREA
BETWEEN 09Z AND 12Z.  THE OUTFLOW WILL DRIFT SOUTH ACROSS THE
FORECAST AREA DURING THE MORNING...POSSIBLY TO INTERSTATE 80...WITH
PRECIPITATION PROBABLY DISSIPATING. MOSTLY SUNNY SKIES SOUTH OF THIS
AREA WILL DRIVE TEMPS INTO THE LOWER 90S SUNDAY AFTERNOON...10
DEGREES COOLER FAR NORTH. CAPES FROM INTERSTATE 80 SOUTH COULD REACH
4500 TO 5000 SUNDAY AFTERNOON. WITH A VORT MAX MOVING THRU DURING THE
AFTERNOON...RENEWED CONVECTION ALONG THE OUTFLOW BOUNDARY COULD
INITIATE AND HEAD EAST OF THE AREA INTO LATE AFTERNOON OR EARLY
EVENING. MEANWHILE...TO THE WEST...STRONG CONVECTION...POSSIBLY A BOW
OR DERECHO...WILL MOVE EAST ACROSS NORTH CENTRAL OR CENTRAL IOWA...
ALONG THE NORTHERN BOUNDARY OF THE THETA-E RIDGE AND NOSE OF THE
LOW-LEVEL JET...AND ALONG OR JUST AHEAD OF THE COLD FRONT.  A
SURFACE LOW ALONG THE FRONT WILL BEGIN TO DEEPEN AS THE FRONT MOVES
INTO THE FORECAST AREA FROM THE WEST IN THE EARLY OR MID EVENING. THE
LOW...AND ASSOCIATED TRIPLE POINT...SHOULD PASS NEAR OR JUST SOUTH OF
DVN IN THE 05Z-06Z TIME FRAME. VV'S WILL BE STRONG AHEAD OF AND WITH
THE FRONT. THE LOW WILL DEEPEN MORE RAPIDLY AS IT MOVES EAST
OF THE MISSISSIPPI RIVER INTO NORTH CENTRAL AND CENTRAL ILLINOIS
IN THE 06Z-09Z TIME FRAME...WITH THE ASSOCIATED CONVECTION GAINING
STRENGTH. THE PRIMARY THREAT WITH THIS SYSTEM WILL BE STRAIGHT LINE
WINDS...POSSIBLY UP TO 80 MPH. LARGE HAIL WILL ALSO BE POSSIBLE
ALTHOUGH THE WET-BULB ZERO WILL BE A TOUCH HIGH AT 13K FT. ISOLATED
TORNADOES ASSOCIATED WITH THE TRIPLE POINT CAN NOT BE RULED OUT.  THE
SYSTEM WILL GAIN STRENGTH INTO THE LATE EVENING...MOVING EAST OF THE
MISSISSIPPI RIVER AND EAST OF THE FORECAST AREA.

LOWER TEMPS AND DEW POINTS WILL MOVE BACK INTO THE AREA FOR A FEW
DAYS AFTER THIS SYSTEM PASSES THRU...ON A VIGOROUS NORTHWEST FLOW.
THE NEXT CHANCE FOR PRECIPITATION...OTHER THAN THE CHANCE OF A
SPRINKLE OR TWO ON MONDAY AFTERNOON THROUGH TUESDAY ASSOCIATED WITH
CYCLONIC FLOW ALOFT...WILL BE IN THE SATURDAY TIME FRAME.

WILL KEEP CLOSE TO CURRENT FORECAST.  TOOK OUT MENTION OF PRECIP
MONDAY...DUE TO PROGRESSIVE NATURE OF COLD FRONT.

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

$$

REA