Severe Thunderstorm Warning 103, NWS Detroit, MI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1111 AM EDT MON JUN 14 2004

.UPDATE...

UPDATE FOCUS IS WITH CONVECTION THIS AFTERNOON/EVENING AND SEVERE
POTENTIAL. AIRMASS ACROSS SOUTHEAST MICHIGAN IS QUICKLY
DESTABILIZING. DEWPOINTS ARE ALREADY RUNNING IN THE UPPER 60S...WITH
LOWER 70S JUST UPSTREAM ACROSS NORTHERN INDIANA. SOMEWHAT CAPPED
ATMOSPHERE INITIALLY ACROSS SOUTHEAST MICHIGAN HAS LEAD TO MOSTLY
SUNNY SKIES THIS MORNING...WITH GOOD INSOLATION. TEMPERATURES HAVE
CLIMBED INTO THE UPPER 70S BY 15Z...WITH HIGHS IN THE LOW 80S STILL
ON TRACK. MODIFIED 12Z DTX SOUNDING FOR A MODEST 82/67 STILL LEADS
TO 3000J/KG CAPE. WIND FIELDS ARE ALSO DECENT...WITH 20KTS AT
850MB/40KTS AT 500MB...WITH 0-6KM SHEAR AROUND 30M/S. SOUNDINGS ALSO
SHOW SOME MID-LEVEL DRY AIR...WHICH WOULD HELP TO ENHANCE DOWNBURST
POTENTIAL. WIND WILL BE THE PRIMARY HAZARD. FREEZING LEVELS ARE
STILL RUNNING NEAR 13-14KFT...SO HAIL IS ALSO POSSIBLE WITH THE
STRONGER STORMS.

EARLY MORNING CONVECTION ACROSS NORTHERN ILLINOIS BECOMING MORE
ORGANIZED...AND TAKING ON A BOW SHAPE ON THE LEADING EDGE. EXPECT
THIS TO CONTINUE TO DEVELOP EASTWARD INTO AN INCREASINGLY UNSTABLE
AIRMASS. UPPER SHORTWAVE OVER MINNESOTA WILL ALSO MOVE SOUTHEAST
ACROSS WISCONSIN THIS AFTERNOON...PROVIDING SOME SYNOPTIC
LIFT/850-500MB QVECTOR CONVERGENCE. SURFACE ANALYSIS ALSO SHOWS A
WEAK TROUGH NEAR LAKE MICHIGAN...WITH ANOTHER BACK ACROSS CENTRAL
WISCONSIN. 100KT 300MB JET ACROSS THE DAKOTAS WILL ALSO MOVE INTO
THE REGION BY EVENING...WITH LOWER MICHIGAN GETTING INTO SOME UPPER
DIVERGENCE IN THE LEFT FRONT QUADRANT THIS AFTERNOON.

WITH FAST FORWARD PROPAGATING BOW ECHO OVER NORTHERN ILLINOIS...
SEVERE THUNDERSTORM WATCH ALREADY ISSUED FOR THE SOUTHERN CWA UNTIL
22Z. ADDITIONAL CONCERN IS ACROSS THE NORTHERN CWA. BETTER DYNAMICS
WILL AFFECT THE NORTHERN CWA LATER THIS AFTERNOON...WHILE ORGANIZED
COMPLEX WILL ZIP ACROSS THE SOUTH EARLIER IN THE DAY. CONCERN THAT
THE STORM TO THE SOUTH WILL DISRUPT INFLOW/BLOWOFF WILL HELP
STABILIZE THE AREA AND LIMIT THE SEVERE POTENTIAL. HOWEVER STILL
ENOUGH CONCERN TO KEEP A MENTION OF THE SEVERE IN THE
NORTH...ALTHOUGH WITH THE BETTER CHANCE IN THE SOUTH. ZONE UPDATE
OUT...WITH UPDATED HWO TO FOLLOW.

&&

BRAVENDER

.PREV DISCUSSION...352 AM EDT MON JUN 14 2004

SHORT WAVE ENERGY IS BREAKING DOWN THE RIDGE OVER EASTERN NORTH
AMERICA AS THE FLOW ALOFT TRANSITIONS TO A MORE ZONAL PATTERN. THE
00Z UPPER AIR PLOTS SHOWED THE MAIN BELT OF WESTERLIES EXTENDING
FROM THE PACIFIC NORTHWEST TO THE NORTHERN HIGH PLAINS. THIS STRONG
MID/UPPER LEVEL FLOW WILL WORK EAST INTO THE GREAT LAKES REGION
TODAY AND EVENTUALLY TO THE NORTHEAST COAST BY TUESDAY. THE WATER
VAPOR LOOP DOES SHOW A SHORT WAVE OVER THE EASTERN DAKOTAS...WHICH
SHOULD HELP FOCUS CONVECTION ACROSS THE REGION LATER TODAY. THE 07Z
SURFACE MAP SHOWS A VERY WEAK BOUNDARY EXTENDING FROM THE STRAITS OF
MACKINAC THROUGH SOUTHERN WISCONSIN...WITH A MORE WELL DEFINED
SURFACE TROUGH EXTENDING FROM CENTRAL NEBRASKA TO NORTHERN IOWA. THE
CHANCES OF CONVECTION TODAY WILL BE THE MAIN FORECAST CONCERN THIS
PACKAGE.

THE 00Z MODEL SUITE ARE IN FAIRLY GOOD AGREEMENT THAT THE SHORT WAVE
OVER THE DAKOTAS WILL LIFT INTO THE NORTHERN GREAT LAKES REGION THIS
AFTERNOON. THIS WILL SPREAD SOME WEAK DCVA INTO THE SOUTHERN LAKES
REGION THIS AFTERNOON/EARLY THIS EVENING. THE MODELS ARE ALSO
INDICATING THAT THE UPPER LEVEL WIND MAX WILL EXTEND INTO THE
WESTERN GREAT LAKES BY 00Z...PROVIDING SOME WEAK UPPER LEVEL
DIVERGENCE TO SE MICHIGAN. A SURFACE TROUGH WILL ALSO PASS
THROUGH THE REGION LATE THIS AFTERNOON. 0-1KM MIXED LAYER CAPE ON
ETA SOUNDINGS SHOW BETWEEN 1500 AND 2000 J/KG ACROSS SE MICHIGAN BY
18/21Z AS TEMPS RISE INTO THE LOWER 80S WITH DEWPOINTS IN THE MID
60S. ALTHOUGH SURFACE INSTABILITY WILL NOT BE AS GREAT AS IT WAS
YESTERDAY...WINDS NEAR 500MB WILL STRENGTHEN TO 45 TO 50 KNOTS THIS
AFTERNOON...ALLOWING 0-6KM SHEAR TO INCREASE TO 30 M/S. THIS SHOULD
ALLOW CONVECTION TO DEVELOP INTO MULTI CELL CLUSTERS...SOME OF WHICH
MAY BECOME LINEAR AND PRODUCE SEVERE WIND GUSTS. WITH THE LIKELIHOOD
OF SOME SURFACE BOUNDARIES OVER THE AREA...ISOLATED SUPERCELLS WILL
ALSO BE POSSIBLE. WITH WET BULB ZERO HEIGHTS BETWEEN 9 AND 10K
FT...THE STRONGER STORMS WILL BE CAPABLE OF LARGE HAIL.

THE ETA SOLUTION WOULD INDICATE WIDESPREAD COVERAGE TO THE
CONVECTION LATE THIS AFTERNOON AND EVENING. THE ETA SOLUTION
DEVELOPS AN MCS OVER IOWA THIS MORNING...THEN TRACKS THE REMNANTS
ACROSS THE SOUTHERN LAKES LATER THIS AFTERNOON. THUS
FAR...CONVECTION UPSTREAM HAS BEEN MORE SCATTERED...WITH LESS
COVERAGE THAN INDICATED BY THE ETA. THE 04KM WRF ACTUALLY HAS THE
BEST HANDLE ON THE CONVECTION THUS FAR...AND IS SUGGESTIVE OF THE
CONVECTION BEING MORE SCATTERED IN NATURE THIS AFTERNOON OVER LOWER
MI...EXCEPT OVER THE SAGINAW VALLEY. AS FOR THIS MORNING...WILL
INCLUDE A LOW CHANCE FOR SHOWERS/THUNDERSTORMS AS SOME WEAK LOW
LEVEL THETA E ADVECTION MOVE INTO THE AREA FROM THE WEST. THE RUC IS
ALSO INDICATING A WEAK MID LEVEL SHORT WAVE OVER NORTHERN
ILLINOIS...MOVING EAST. THESE FEATURES HAVE ALLOWED SOME CONVECTION
TO DEVELOP IN THE MILWAUKEE AREA THIS PAST HOUR.

WEAK SHORT WAVE RIDGING AND SURFACE HIGH PRESSURE WILL BUILD INTO
THE AREA TONIGHT IN THE WAKE OF THE CONVECTION. SURFACE HIGH
PRESSURE WILL LINGER OVER THE AREA ON TUESDAY. THIS COUPLED WITH
MUCH DRYER AIR AT 850MB SHOULD PROVIDE A DRY DAY ACROSS THE AREA. A
SHORT WAVE TROUGH WILL DEEPEN OVER NORTHERN PLAINS ON TUESDAY...THEN
MOVE INTO NORTHERN ONTARIO BY WEDNESDAY. THIS WILL SEND A COLD FRONT
SOUTHEAST ACROSS THE GREAT LAKES ON WEDNESDAY. THE 00Z MODEL SUITE
ARE ACTUALLY IN REASONABLY GOOD AGREEMENT ON TIMING THE FRONTAL
BOUNDARY INTO SE MICHIGAN ON WEDNESDAY...INDICATING A LATE
AFTERNOON/EARLY EVENING FROPA. THIS OF COURSE WILL ALLOW INSTABILITY
TO BUILD OVER THE REGION PRIOR TO FROPA. WITH THE REGION WITHIN THE
ENTRANCE REGION OF A 130KT 250MB JET...VERY STRONG FOR MID
JUNE...AND GIVEN THE STRONG MID LEVEL FLOW OVER THE LOWER
LAKES...THERE WILL AGAIN BE A CHANCE FOR SEVERE WEATHER. THE TRENDS
IN THE ETA AND GFS HAVE BEEN TOWARD DRYER AIR IN THE LOW LEVELS
EARLY WEDNESDAY...WITH THE BULK OF THE MOISTURE CONFINED TO A NARROW
AXIS ALONG THE COLD FRONT. WILL THUS TRIM BACK THE CHANCES OF
CONVECTION TO WEDNESDAY AFTERNOON/WEDNESDAY NIGHT. WILL ALSO RAISE
MAX TEMPS A FEW DEGREES ON WEDNESDAY GIVEN THE STRONG THERMAL
ADVECTION AHEAD OF THE FRONT.

THE EXTENDED FORECAST LOOKS IN GOOD SHAPE SO NO UPDATES WILL BE
NEEDED. ALL MEDIUM RANGE MODEL SOLUTIONS CONTINUE TO SHOW A HIGHLY
AMPLIFIED RIDGE BUILDING INTO WESTERN CANADA BY THE WEEKEND...WITH A
DEEPENING UPPER LOW OVER HUDSON BAY. THIS WILL OF COURSE LEAD TO
LOWER HEIGHTS OVER THE GREAT LAKES AND COOLER THAN NORMAL
TEMPERATURES OVER SE MICHIGAN.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

CONSIDINE

EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT
HTTP://WWW.CRH.NOAA.GOV/DTX  (ALL LOWER CASE)

HAZARDOUS WEATHER OUTLOOK FOR SOUTHEAST MICHIGAN
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1239 PM EDT MON JUN 14 2004

MIZ063-068>070-075-076-082-083-151100-
LENAWEE-LIVINGSTON-MACOMB-MONROE-OAKLAND-ST. CLAIR-WASHTENAW-WAYNE-
1239 PM EDT MON JUN 14 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST MICHIGAN.

.DAY ONE...THIS AFTERNOON AND TONIGHT

SEVERE THUNDERSTORM WATCH 467 IS IN EFFECT UNTIL 6 PM.

NUMEROUS THUNDERSTORMS ARE EXPECTED THIS AFTERNOON...WITH STORMS
BECOMING MORE SCATTERED THIS EVENING. THERE IS A CHANCE OF SEVERE
WEATHER WITH THESE THUNDERSTORMS. WIND GUSTS TO 70 MPH ARE THE MAIN
HAZARD...WITH HAIL TO ONE INCH IN DIAMETER ALSO POSSIBLE. IN
ADDITION...BRIEF HEAVY RAIN COULD CAUSE LOCALIZED PONDING OF WATER
ON ROADWAYS. STORM MOTION WILL BE TO THE EAST AT 45 MPH.

AN UPPER LEVEL DISTURBANCE AND SURFACE TROUGH WILL MOVE ACROSS LOWER
MICHIGAN THIS AFTERNOON AND EVENING. THE AIRMASS ACROSS SOUTHEAST
MICHIGAN WILL BECOME INCREASINGLY UNSTABLE THIS AFTERNOON...AND
THUNDERSTORMS WILL CONTINUE TO DEVELOP. THE BEST CHANCE FOR SEVERE
WEATHER WILL BE BETWEEN 2 PM AND 6 PM THIS AFTERNOON.

.DAY TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

SCATTERED THUNDERSTORMS ARE EXPECTED WEDNESDAY AFTERNOON AND
WEDNESDAY EVENING. THERE IS A CHANCE OF SEVERE WEATHER WITH THESE
THUNDERSTORMS. A COLD FRONT WILL MOVE ACROSS THE STATE ON WEDNESDAY.
AN UNSTABLE AIRMASS OVER SOUTHEAST MICHIGAN AHEAD OF THIS FRONT WILL
PROVIDE THE CHANCE FOR STRONG TO SEVERE THUNDERSTORMS.

THERE IS A CHANCE OF THUNDERSTORMS AGAIN ON FRIDAY AS ANOTHER COLD
FRONT MOVES ACROSS THE REGION.

.SPOTTER INFORMATION STATEMENT...

DISPATCHERS...PLEASE NOTIFY YOUR EMERGENCY MANAGER IMMEDIATELY.

THE SPOTTER NETWORK HAS BEEN ACTIVATED.

MIZ047>049-053>055-060>062-151100-
BAY-GENESEE-HURON-LAPEER-MIDLAND-SAGINAW-SANILAC-SHIAWASSEE-TUSCOLA-
1239 PM EDT MON JUN 14 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST MICHIGAN.

.DAY ONE...THIS AFTERNOON AND TONIGHT

SEVERE THUNDERSTORM WATCH 468 IS IN EFFECT UNTIL 8 PM.

NUMEROUS THUNDERSTORMS ARE EXPECTED THIS AFTERNOON...WITH STORMS
BECOMING MORE SCATTERED THIS EVENING. THERE IS A CHANCE OF SEVERE
WEATHER WITH THESE THUNDERSTORMS. WIND GUSTS TO 70 MPH AND HAIL TO
ONE INCH IN DIAMETER ARE THE MAIN HAZARDS. HEAVY RAIN IS ALSO
POSSIBLE...WHICH COULD CAUSE PONDING OF WATER ON ROADWAYS. STORM
MOTION WILL BE TO THE EAST AT 30 MPH.

AN UPPER LEVEL DISTURBANCE AND SURFACE TROUGH WILL MOVE ACROSS LOWER
MICHIGAN THIS AFTERNOON AND EVENING. THE AIRMASS ACROSS SOUTHEAST
MICHIGAN WILL BECOME INCREASINGLY UNSTABLE THIS AFTERNOON...AND
THUNDERSTORMS WILL CONTINUE TO DEVELOP. THE BEST CHANCE FOR SEVERE
WEATHER WILL BE BETWEEN 2 PM AND 8 PM THIS AFTERNOON.

.DAY TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

SCATTERED THUNDERSTORMS ARE EXPECTED WEDNESDAY AFTERNOON AND
WEDNESDAY EVENING. THERE IS A CHANCE OF SEVERE WEATHER WITH THESE
THUNDERSTORMS. A COLD FRONT WILL MOVE ACROSS THE STATE ON WEDNESDAY.
AN UNSTABLE AIRMASS OVER SOUTHEAST MICHIGAN AHEAD OF THIS FRONT WILL
PROVIDE THE CHANCE FOR STRONG TO SEVERE THUNDERSTORMS.

THERE IS A CHANCE OF THUNDERSTORMS AGAIN ON FRIDAY AS ANOTHER COLD
FRONT MOVES ACROSS THE REGION.

.SPOTTER INFORMATION STATEMENT...

DISPATCHERS...PLEASE NOTIFY YOUR EMERGENCY MANAGER IMMEDIATELY.

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING.

BRAVENDER