Damaging Winds in Michigan, August 4, 2002

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
225 PM EST SUN AUG 4 2002

FORECAST CHALLENGES WILL LIE WITH TIMING/PCPN COVERAGE WITH CDFNT
NEXT 24 HOURS AND TEMPS INTO THE EXTENDED.

SHORT TERM DISCUSSION...
88DS/VIS SAT SHOWING SEVERAL WEAK OUTFLOW BOUNDARIES ACROSS N
INDIANA/S MICHIGAN. LAPS INDICATES CAPES >2K J/KG AND LIS -5 TO
-7. CDFNT LOCATED AT 18Z FROM THE CENTRAL U.P. OF MI...TO CNTRL WI...
TO N IOWA. MODELS IN AGREEMENT ON THE FRONT DROPPING SOUTH AS HIGH
PRESSURE BUILDS IN BEHIND. MODELS NOW DEPICTING MORE IN THE WAY OF
CONVERGENCE AND INSTABILITY INTO THE OVERNIGHT HOURS. BY 12Z MON...
PWS WILL EXCEED 2...DECENT VVS WILL BE MOVING THROUGH THE AREA
AND THE SFC FRONT WILL BE IN THE GENERAL AREA. MOST WIDESPREAD
CONVECTION WILL LIKELY START IN THE NORTH AND CENTRAL THIS EVENING
AND SPREAD SOUTH DURING THE NIGHT AND INCREASING IN COVERAGE AS S/W
MOVES IN AND FRONT GETS CLOSER. MID LVL CAP APPEARS TO BE
SUPPRESSING MOST ACTIVITY...HOWEVER ISOLATED CONVECTION HAS STARTED
TO POP EAST AND SOUTH OF FWA...WITH SCT CONVECTION IN SW LWR.
SOUNDINGS NOT OVERLY IMPRESSIVE FOR SVR WX...HOWEVER WITH HIGH
PWS...DECENT INSTABILITY AND SOME DRIER AIR ALOFT TO BE MIXED DOWN
WITH PRECIP LOADING CANT RULE OUT SOME ISOLATED WET MICROBURSTS. AT
A MIN...WILL KEEP HIGH CHC POPS GOING TONIGHT AND DEPENDING ON RADAR
TRENDS MAY BUMP UP TO LIKELY. MODEL GUIDANCE RANGES FROM 50 POPS(NGM)
TO 70-80 POPS(AVN/ETA) IN THE NORTH AND CNTRL.

SFC FRONT MOVES THROUGH DURING THE MORNING...DOING LITTLE MORE THAN
SHIFT THE WIND. DEWPTS ACROSS THE CNTRL AND SOUTHERN PORTIONS OF
THE CWA WILL REMAIN FROM 68 TO 72 THROUGH MUCH OF THE DAY...PRIOR TO
THE 850 MB FRONT MOVING IN. MODELS SHOW POST SFC FRONTAL QPF SLOWLY
SHIFTING SOUTH THROUGH THE DAY AND CAN SEE NO REASON TO ARGUE. WILL
KEEP WORDING AS IS FOR TIMING WITH MORNING WORDING MAINLY N OF US-
30...AND ALL DAY SOUTH. WITH CLOUD CVR AND SLOWLY DECREASING 850 MB
TEMPS...HIGHS WILL BE COOLER...WITH READINGS IN THE MID-UPR 80S
LOOKING GOOD.

AFTER THIS...HIGH PRESSURE WILL DOMINATE CONDITIONS WITH 850 MB
TEMPS DROPPING TO +10 TO +12...ALLOWING FOR MUCH MORE PLEASANT HIGHS
AND LOWER HUMIDITIES. GUIDANCE NUMBERS REASONABLE AND IN LINE WITH
EACH OTHER.

EXTENDED DISCUSSION...

FEW CHANGES TO EXTENDED AS HIGH PRESSURE WILL DOMINATE THE AREA
THROUGH THE PERIOD. UPPER RIDGE TRIES TO MOVE EAST A LITTLE MORE BY
THE LATE PART OF THE WEEK AND THE WEEKEND. STILL DOES NOT LOOK LIKE
ENOUGH RETURN FLOW FOR HOT CONDITIONS...BUT TEMPS SHOULD BE BACK
WELL INTO 80S. UPPER LOW MOVES INTO PLAINS BY WEEKEND AND UPPER
HIGH BEGINS TO MOVE WEST. TROF APPROACHES LATE SUNDAY SO WL HOLD OFF
ANY PCPN CHANCES AS IT LOOKS TO BE LATE SUNDAY.

.IWX...NONE.

FISHER/LASHLEY