[LeArc] Forecast Discussion : MLI@ 8/2/02 2:37:52 PM

[learc@mailman.qth.net]

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


FXUS63 KDVN 021939
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
239 PM CDT FRI AUG 2 2002

SYNOPTIC PICTURE THIS AFTERNOON SHOWS 110KT JET ALONG U.S.-CANADIAN
BORDER FROM BC TO ONTARIO.  AT 500H A STRONG HIGH IS CENTERED OVER
MISSOURI...WITH A STRONG WEST-EAST FLOW NORTH INTO CANADA...AND A
SHORT WAVE OVER THE STATE OF WASHINGTON.  AT THE SURFACE A 1024MB HIGH
IS CENTERED OVER NORTHWEST IOWA. TO THE WEST A WEAK LOW IS IN NORTHERN
WYOMING...WITH A TROF EXTENDING INTO EASTERN COLORADO.

THE PRIMARY FORECAST CONCERNS THIS PACKAGE ARE THREE-FOLD.  FIRST IS
MIN TEMPS TONIGHT...WHICH WILL PROBABLY GO BELOW CURRENT FORECAST.
SECOND IS PRECIP CHANCES ASSOCIATED WITH A COLD FRONT ON SUNDAY.
THIRD IS THE MAGNITUDE OF COOLER INTO AND THROUGH THE WORK WEEK...AS A
HIGH BUILDS DOWN FROM CANADA INTO THE GREAT LAKES...BRINGING A COOLER
EASTERLY FLOW.

THE SHORT-TERM MODELS INITIALIZED WELL AT THE SURFACE...WITH THE ETA
HAVING THE EDGE AT 500H OVER THE PLAINS.  THE MODELS AGREE ON BRINGING
THE COLD FRONT ACROSS THE FORECAST AREA SUNDAY...WITH THE AVN AND ETA
DURING THE DAY...AND THE NGM IMPLYING EVENING OR OVERNIGHT. THE FRONT
THEN LINGERS JUST SOUTH INTO MONDAY. PVA...STRONG VV'S...AND UPPER
DIVERGENCE WILL PROBABLY BE PRIMARILY JUST NORTHWEST OF THE FORECAST
AREA SATURDAY NIGHT...WITH WEAKER VV'S AND UPPER DIVERGENCE ACROSS THE
AREA SUNDAY AND SUNDAY NIGHT.

LOOKING FURTHER AHEAD...THE MEDIUM RANGE MODELS AGREE ON A STRONG
SURFACE HIGH BUILDING DOWN FROM CANADA INTO THE CENTRAL GREAT LAKES
MIDWEEK.  THE FETCH THRU TUESDAY AND INTO TUESDAY NIGHT WILL BE DOWN
LAKE MICHIGAN ON A NORTHEAST FLOW THAT TURNS EAST OVER THE FORECAST
AREA.  ON WEDNESDAY THE FLOW BECOMES STRAIGHT EAST...LIGHT SOUTHEAST
THURSDAY...AND THEN LIGHT SOUTH FRIDAY.  INDICATIONS ARE THAT
SIGNIFICANT COOLING WILL MAINTAIN THRU MIDWEEK.

WILL STAY WITH CURRENT FORECAST...EXCEPT TRIMMING BACK A BIT ON POPS
THIS WEEKEND AND MONDAY.  WILL TEND TOWARDS COOLER MEX IN EXTENDED.

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

REA