Severe Thunderstorm Warning 29, NWS Detroit, MI

SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
339 PM EDT SAT JUN 2 2001

STACKED LOW EASILY IDENTIFIED IN SATELLITE AND RADAR IMAGERY...
TRACKING INTO WRN LOWER MI THIS AFTERNOON. THE WL SLOWLY PROGRESS
EAST TONIGHT ACROSS THE NRN CWA...MEANDERING TO NRN NEW ENGLAND BY
MONDAY...WITH A TROF AXIS EXTENDING BACK ACROSS THE FAR NRN LAKES.
MEANWHILE...A PIECE OF ENERGY WL BREAK OFF FROM THE UPPER LOW MOVING
ONSHORE OVER BRITISH COLUMBIA. THIS SHORTWAVE WL TRANSIT THE
ROCKIES...PRODUCING CYCLOGENESIS IN THE SRN PLAINS.

LINGERING HEAT-OF-THE-DAY CONVECTION WL WIND DOWN AFTER 6 PM AS MAX
HEATING PASSES AND LOWER SURFACE DEW POINTS ADVECT IN FROM THE SW.
LOTS OF PEA SIZED HAIL WITH THESE CELLS. FORCING ASSOCIATED WITH THE
UPPER LOW IS UNIMPRESSIVE. Q-VECTOR CONVERGENCE IN THE 850-500MB
LAYER BASICALLY DEPARTS THE NE PART OF THE CWA THIS EVENING. BEST
DEFORMATION IN THE SAME LAYER REMAINS TO THE NORTH TONIGHT. CURRENT
RADAR TRENDS SUGGEST LITTLE PRECIP UNDER THE HEART OF THE UPPER
LOW...AND WL JUST GO SCT SHRA FOR THE OVERNIGHT.

PLENTIFUL LOW LEVEL MOISTURE...CYCLONIC FLOW...AND DAYTIME HEATING
WL BE PRESENT SUNDAY. EVEN SO...TEMPS ALOFT WARM SUBSTANTIALLY AS
UPPER LOW PULLS AWAY...AND NVA WORKS IN AS WELL. ETA MODELS TRY TO
PRODUCE A FEW HUNDRED JOULES OF SHALLOW INSTABILITY...BUT THE
MID-50S DEW POINTS LOOK A BIT TOO HIGH. LOOKING TO THE WEST ACROSS
IOWA AND MN...HEALTHY AMOUNT OF CU DEVELOPMENT...BUT NO SHRA. DEW
POINTS ARE IN THE MID TO UPPER 40S...SO HARD TO SEE US EXCEEDING 50
BY MUCH. SO...AFTER CONSIDERING ADDING POPS...WL LEAVE THEM OUT. MID
LEVELS SHOULD DRY OUT CONSIDERABLY DURING THE DAY...ESPECIALLY IN
THE SOUTH. WL LET THINGS BECOME PARTLY SUNNY DURING THE AFTERNOON IN
THE SOUTH...A FEEBLE ATTEMPT TO ADD A HINT OF OPTIMISM TO THE
FORECAST.

SUNDAY NIGHT...CWA IS PINCHED BETWEEN THE DEPARTING STACKED
LOW...AND A DEVELOPING LOW IN THE SRN PLAINS. LOW LEVEL JET WL
RAPIDLY TRANSPORT MOISTURE NORTH INTO THE MID-MS AND OHIO VALLEYS.
HOWEVER...WEAK SURFACE RIDGE WL KEEP THE DEEP MOISTURE AT BAY...WITH
PARTLY CLOUDY AND DRY CONDITIONS.

DEEP MOISTURE WL CONTINUE TO WORK SLOWLY NORTH MONDAY AS INITIAL SRN
PLAINS SURFACE WAVE EJECTS INTO MO...AND THE WARM FRONT TO THE SOUTH
BECOMES BETTER DEFINED IN THE OHIO VALLEY. QG FRONTOGENESIS
INCREASES IN THE 850-500MB LAYER IN SRN LOWER MI...AND THE
DEFORMATION ZONE ALSO LIFTS NORTH INTO THE SRN ZONES DURING THE
AFTERNOON. WL MENTION A CHANCE OF SHRA IN THE SOUTH MONDAY AFTERNOON.

THRU THE FORECAST...ETA 2M TEMPS OFFER A GOOD COMPROMISE BETWEEN
WARMER FWC AND COOLER MAV.

EXTENDED...EXCEPT FOR A SHORTWAVE RIDGE TRANSITING THE LAKES ON
TUESDAY...UPPER TROFFING WL HOLD IN THE ERN THIRD OF THE NATION THRU
THIS EXTENDED PACKAGE. MODELS OVERALL IN GOOD AGREEMENT. THE ETAXX
IS THE MAIN OUTLIER BY THE MIDDLE PART OF NEXT WEEK...ONLY BRINGING
A TRICKLE OF ENERGY INTO THE REGION ON NW FLOW ALOFT. OTHER MODELS
ARE PREFERRED IN BEING MORE AMPLIFIED...WITH A SIGNIFICANT UPPER
TROF CUTTING UNDERNEATH AN UPPER HIGH IN NRN CANADA...AND MOVING
INTO THE LAKES WED.

MAIN BAROCLINIC ZONE WL BE SET UP JUST TO OUR SOUTH EARLY IN THE
EXTENDED...WITH A LEAST TWO SURFACE WAVES MOVING ALONG THE BOUNDARY.
ALWAYS TRICKY IN THE WARM SEASON...TRYING TO FIGURE HOW MUCH
CONVECTION WL OCCUR IN THE WARM SECTOR...AS THIS COULD CUT OFF MUCH
OF THE MOIST INFLOW UP OVER THE BOUNDARY. STILL LOOKS LIKE A GOOD
SHOT AT RAIN...ESPECIALLY IN THE SOUTH...AS ONE WAVE ZIPS ACROSS
INDIANA/OHIO TUE...AND A SECOND LATE TUE NIGHT/EARLY WEDNESDAY. THEN
THE UPPER TROF SLIDES ACROSS...KEEPING US WITH A CHANCE OF SHRA THRU
WED. SURFACE HIGH LOOKS TO DRY US OUT THU/FRI...BEFORE A NORTHWEST
FLOW SHORTWAVE BRINGS A CHANCE OF SHRA SAT.

.DTX...NONE.

ZOLTOWSKI