Severe Thunderstorm Warning 42, NWS Grand Rapids, MI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
300 PM EDT SUN JUN 10 2001

VIGOROUS MID LEVEL SHORTWAVE IN THE NORTHWEST FLOW ALOFT WILL BE
SWINGING THROUGH SW MI EARLY TONIGHT... BRINGING A ROUND OF STRONG
OR PERHAPS SVR TSTMS. MODELS PROG STRONG SUBSIDENCE AND DRYING IN
THE WAKE OF THIS FEATURE... WITH VERY PRONOUNCED SFC RIDGING. WILL
THEREFORE DRY THINGS OUT LATER TONIGHT AND CONTINUE TO ADVERTISE A
MOSTLY SUNNY AND WARM DAY ON MONDAY. THINGS APPEAR TO GET ACTIVE
AGAIN ON MONDAY NIGHT/TUESDAY AS UPPER FLOW FLATTENS AGAIN AND MORE
RIPPLES DEVELOP UPSTREAM IN THE WESTERLIES AND SCOOT THROUGH. THESE
DISTURBANCES WILL HAVE A VERY MOIST AND UNSTABLE ENVIRONMENT TO
CAPITALIZE ON... WITH 65 TO 70 DEW POINTS AROUND AND CAPES PUSHING
3000 J/KG. QUASI-STATIONARY SURFACE BOUNDARY WILL CONTINUE FLIRTING
WITH THE AREA AS WELL.  AGAIN...TIMING/LOCATION OF THESE RIPPLES IS
VERY TOUGH BEYOND 24 HOURS...SO ITS HARD TO PINPOINT WHICH PART OF
THE FCST (AND WHERE) TO INSERT LIKELY POPS FOR TSTMS. WILL THEREFORE
AT THIS POINT GO WITH CHANCE WORDING MONDAY NIGHT...TUESDAY AND
TUESDAY NIGHT.  GIVEN THE PROGGED INSTABILITY AND STRONG BELT OF
WESTERLIES ALOFT...A FEW STRONG CONVECTIVE COMPLEXES WILL LIKELY
AFFECT SW MI IN THIS TIME PERIOD.

WITH INFLUX OF VERY WARM AIR...POTENTIAL ALSO EXISTS FOR AT LEAST
SRN PORTIONS OF THE AREA TO BECOME CAPPED IN LATER PERIODS SOUTH OF
THE WARM FRONT. WILL THEREFORE FEATURE LOWEST CHC POPS THERE AND
HAVE VERY WARM/HUMID WORDING. FIRST 90 DEGREE DAY APPEARS POSSIBLE
TUESDAY FOR AT LEAST THE I-94 CORRIDOR DEPENDING ON EVENTUAL
POSITION OF FRONTAL BOUNDARY AND AMOUNT OF SUN. THINKING BOUNDARY
WILL LIKELY GET HUNG UP ACROSS CENTRAL LOWER MICHIGAN TUESDAY.

MEADE

EXTENDED FORECAST DISCUSSION...
SWRLY FLOW ALOFT WILL BRING THE WARMEST AIR OF THE SEASON THUS FAR
INTO THE FORECAST AREA ON WED...WITH AFTERNOON TEMPS LIKELY
APPROACHING 90 DEG F OVER INTERIOR COUNTIES. AVN/MRF SOLUTIONS STILL
BRING TROPICAL GULF MOISTURE NWD INTO THE STATE FOR THU/THU NIGHT
AHEAD OF APPROACHING SHORTWAVE TROUGH AND SFC COLD FRONT. WILL HAVE
TO MONITOR THE REMNANT MOISTURE AXIS FROM ALLISON...AS HEAVY RAIN
POTENTIAL MAY EXIST WITH CONVECTION THU AFTERNOON/NIGHT ACROSS
PORTIONS OF THE FORECAST AREA. MODELS SUGGEST SIMILAR TIMING FOR
COLD FRONTAL PASSAGE LATE THU NIGHT/FRI MORNING...WITH GOOD DRYING
BEHIND FRONT FOR FRI. DAYS 6 AND 7 DIFFICULT TO CALL AS MODELS SHOW
FAST ZONAL FLOW ACROSS THE NRN U.S. THIS SCENARIO WILL ALLOW FOR
FAST MOVING DISTURBANCES...BRINGING THE THREAT FOR SCATTERED
CONVECTION EVERY OTHER DAY OR SO. WILL KEEP SAT DRY...BUT BRING IN
ANOTHER CHANCE FOR CONVECTIVE ACTIVITY ON SUN.

GREENE

.GRR...NONE.