Damaging Wind in Ohio, August 2, 2001

AREA FORECAST DISCUSSION...CORRECTED TO WORDING
NATIONAL WEATHER SERVICE NORTHERN INDIANA
216 AM EST THU AUG 2 2001

FORECAST CHALLENGE TODAY WILL TIMING OF THE COLD FRONT AND HOW FAR
IT SAGS SOUTH.

CURRENT SURFACE CHART CONTINUES TO SHOW MUGGY AIR ACROSS THE REGION
WITH PARTLY TO MOSTLY CLOUDY AND HAZY SKIES.  DEWPOINTS CONTINUE TO
BE IN THE LOWER TO MIDDLE 70S. MIDDLE TO HIGH CLOUDINESS IS COMING
FROM A DYING MCS OVER ILLINOIS. IR IMAGE CLOUD TOPS HAVE CONTINUED TO
WARM OVER ILLINOIS...BUT THERE IS NEW DEVELOPMENT OVER EASTERN IOWA
ALONG THE COLD FRONT.  COLD FRONT CONTINUES TO LAG BEHIND EXTENDING
FROM UPPER MICHIGAN TO CENTRAL IOWA. THE LEADING EDGE OF THE
PRECIPITATION CURRENTLY EXTENDS FROM CENTRAL LAKE MICHIGAN TO HENRY
COUNTY IN NORTHWEST ILLINOIS. THE PRECIPITATION IS MOVING EAST AT
ABOUT 10 MPH.

ALL THE MODELS HAVE FRONT THROUGH OUR CWA BY FRIDAY MORNING...WITH
THE ETA THE SLOWEST OF THE THREE. ALL THREE HAVE THE UPPER RIDGE
RETROGRADING TO THE WEST WHICH WILL ALLOW THE COLD FRONT TO
ADVANCE SOUTHEAST ACROSS OUR AREA.  THIS IS THE TREND AS PROFILER
DATA SHOWING NORTHWEST WINDS AT 500 MBS OVER NORTHWEST INDIANA
ALREADY.  WILL LEAN TOWARD THE ETA SOLUTION IN MAKING THE
FORECAST BECAUSE IT HAD THE BEST HANDLE ON THE PLACEMENT AND
STRENGTH OF THE ILLINOIS MCS.  THE ATMOSPHERE REMAINS QUITE UNSTABLE
WITH PRECIPITABLE WATER OF NEARLY 2 INCHES BEING INDICATED BY THE
00Z KDVN SOUNDING BUT WITH UPPER RIDGE STILL IN PLACE OVER THE
AREA...THE CAPPING INVERSION WILL CONTINUE TO INHIBIT PRECIPITATION.

A PRE-FRONTAL TROUGH WILL DEVELOP THIS MORNING ACROSS NORTHERN
ILLINOIS IN ADVANCE OF THE FRONT. THIS WILL BE THE FOCUS OF
THUNDERSTORM DEVELOPMENT.  SEVERE STORMS ARE NOT ANTICIPATED THIS
AFTERNOON EVEN THOUGH THERE IS STRONG INSTABILITY.  FREEZING LEVELS
ARE TOO HIGH FOR LARGE HAIL AND WIND FIELDS ARE QUITE WEAK.  THE
PRIMARY THREAT WILL BE HEAVY RAIN.  STORMS THAT DO DEVELOP HAVE THE
CAPABILITY OF DROPPING 2 INCHES OF RAIN PER HOUR.  WILL CONTINUE THE
CHANCE OF THUNDERSTORMS ACROSS THE ENTIRE CWA FOR TODAY...WITH THE
BEST CHANCE BEING SOUTH AND EAST OF A MONTPELIER OHIO TO MONTICELLO
INDIANA LINE. THIS ALL DEPENDS ON THE TIMING OF FRONTAL PASSAGE.
WITH FRONTAL PASSAGE EXPECTED VERY LATE TONIGHT...WILL KEEP A DRY
FORECAST FOR THE NORTHWEST FRIDAY AND A SMALL CHANCE POP SOUTHEAST
FRIDAY MORNING.

FOR TEMPERATURES...WILL USE A BLEND OF F~WC/FAN/MAV GUIDANCE.

EXTENDED LEFT UNCHANGED.

.IWX...NONE.

GLL