[LeArc] Forecast Discussion : MLI@ 9/17/02 2:35:52 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 170743
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
243 AM CDT TUE SEP 17 2002

SYNOPTIC PICTURE THIS MORNING SHOW STRONG SURFACE HIGH MOVING EAST INTO
OHIO VALLEY...WHILE A TROF MOVES INTO THE HIGH PLAINS. A DEVELOPING
SOUTHEAST FLOW ACROSS THE REGION HAS BROUGHT 65 DEW POINTS AS FAR
NORTH AS STL. AT 500H A WELL-DEFINED SHORT WAVE IS LIFTING NORTHEAST
FROM NORTHEAST OKLAHOMA INTO SOUTHWEST MISSOURI.

THE PRIMARY FORECAST CONCERN THIS CYCLE IS COMPLEX RAINFALL EVENT FROM
THIS EVENING THRU WEDNESDAY AND THURSDAY.  ALSO OF INTEREST IS A
LESSER PRECIP EVENT IN THE SATURDAY TIME FRAME.  MAIN CHANGE FROM
PREVIOUS PACKAGES IS HIGHER DEW POINTS IN THE 60S RETURNING THIS
AFTERNOON THROUGH WEDNESDAY INTO THURSDAY...AND EARLIER ONSET OF
PRECIP CHANCES.

THE SHORT-TERM MODELS AGREE ON THE OKLAHOMA SHORT WAVE LIFTING INTO
THE SOUTHERN PORTION OF THE FORECAST AREA LATE THIS AFTERNOON...AND
THEN NORTH THRU THE FORECAST AREA TONIGHT. A WARM FRONT WILL LIFT THRU
THE FORECAST AREA WEDNESDAY AND WEDNESDAY EVENING...PROVIDING
ISENTROPIC LIFT WEDNESDAY AND WEDNESDAY EVENING.  A MODERATELY STRONG
COLD FRONT WILL MOVE THRU THURSDAY...WITH THE AVN INDICATING A STRONG
SHORT WAVE MOVING FROM SOUTHWEST TO NORTHEAST ALONG THE FRONT.  THE
500H TROF AXIS FOLLOWS 12Z FRIDAY.  WEDNESDAY NIGHT COULD SEE HEAVY
RAINFALL...WITH A SECOND PUNCH OF HEAVY RAIN THURSDAY WITH SHORT WAVE
ALONG FRONT.

LOOKING FURTHER AHEAD...A SECONDARY WAVE WILL MOVE THRU FRIDAY NIGHT...
WITH HIGH PRESSURE BUILDING IN THRU THE WEEKEND.  AN INVERTED TROF IS
POSSIBLE IN THE MONDAY TIME FRAME.

WILL STAY CLOSE TO CURRENT FORECAST. MAY INTRODUCE LOW POPS SOUTH THIS
AFTERNOON.  MAY ALSO KEEP PRECIP LONGER AFTER COLD FRONT...THRU THURSDAY
NIGHT. FOCUS FOR PRECIP AFTER THAT...THRU THE EXTENDED PERIOD...BECOMES
MORE DIFFUSE...SO MAY BACK OFF ON PRECIP FOR SATURDAY.  TEMPERATURES
ARE ON TRACK...WITH MAJOR COOL DOWN THURSDAY THRU WEEKEND...AND INTO
NEXT WEEK.

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

REA