[LeArc] Forecast Discussion : MLI@ 6/2/2002 2:38:18 AM

[learc@mailman.qth.net]

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


FXUS63 KDVN 020734
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
234 AM CDT SUN JUN 2 2002

SYNOPTIC PICTURE THIS MORNING SHOWS A 120KT JET CENTERED OVER THUNDER
BAY...WITH A 500H RIDGE OVER CENTRAL PLAINS AND TROF ALONG WEST COAST...
AND WNW FLOW OVER DVN.  AT THE SURFACE A STATIONARY FRONT EXTENDS EAST-
WEST ACROSS SOUTHERN IOWA INTO NORTH CENTRAL ILLINOIS.  CONVECTION
FIRED ALONG THE FRONT IN SOUTH CENTRAL IOWA EARLIER TONIGHT...BUT
DIVED SOUTHEAST AND DISSIPATED.  MORE EXTENSIVE CONVECTION EXTENDS FROM
SOUTHERN SOUTH DAKOTA INTO CENTRAL IOWA ALONG 850H FRONT...AND ON NOSE
OF 45KT LLJ.

MODELS INITIALIZED WELL AT 00Z AT 500H AND THE SURFACE.  HOWEVER...BY
06Z...AVN AND NGM STILL CLOSE TO TREND BUT ETA WAY WAY OFF...PLACING
FRONT SOUTH INTO CENTRAL MISSOURI.  AVN IS HANDLING PRECIP TREND IN
THE DAKOTAS AND WESTERN IOWA THE BEST...WITH THE ETA O.K...AND THE NGM
POOR.

THE PRIMARY FORECAST CONCERNS THIS PACKAGE CONTINUE TO BE THE
STATIONARY FRONT ACROSS THE FORECAST AREA THRU MONDAY NIGHT...GETTING
KICKED EAST ON TUESDAY WITH A PASSING LOW.  THIS WILL PROVIDE THE
POTENTIAL FOR LOCALLY HEAVY RAIN AND SEVERE WEATHER.

THE SHORT-TERM MODELS HAVE A HARD TIME AGREEING ON THE STATIONARY FRONT
OVER THE NEXT 48 HOURS...WITH THE ETA BEING ODD-MODEL OUT THRU 24
HOURS...AND NGM OUT TIL 48 HOURS.  MAIN CONSENSUS IS THAT FRONT WILL
LURK NEAR IOWA-MISSOURI LINE TODAY AND TONIGHT...LIFTING INTO SOUTHERN
OR CENTRAL FORECAST AREA MONDAY AND MONDAY NIGHT...AND GETTING KICKED
EAST TUESDAY AS SURFACE LOW RIDES EAST ALONG FRONT MIDDAY.  AT 500H
THERE ARE SEVERAL VERY WEAK WAVES OVER THE NEXT FEW DAYS...WITH THE
PRIMARY TROF MOVING OVER DVN WEDNESDAY NIGHT IN THE 06Z TIME FRAME.
THE EUROPEAN AND UK AGREE ON THIS SCENARIO.  SPC KEEPS FORECAST AREA
UNDER THE GUN WITH SLIGHT RISK SEVERE OVER THE NEXT 2 DAYS...WITH HAIL
AND STRAIGHT LINE WINDS BEING THE PRIMARY THREAT...ALTHO ISOLATED
TORNADOS CAN NOT BE RULED OUT DUE TO STATIONARY FRONT.  QPF IS
TRICKY...WITH EACH MODEL PUTTING VV'S AND UPPER SUPPORT IN DIFFERENT
AREAS.  SHOWERS WILL SPILL INTO FORECAST AREA THIS MORNING FROM
CENTRAL IOWA...AND MAY CONTINUE INTO AFTERNOON.  QPF FOCUS FOR TONIGHT
THROUGH MONDAY AND TUESDAY WILL BE NORTHERN PORTION OF FORECAST AREA.

WILL LOWER TEMPS A NOTCH FOR TODAY DUE TO SIGNIFICANT CLOUD COVER.
OTHERWISE...ONLY MINOR CHANGES TO ONGOING FORECAST.

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

REA