Marine Hail in Lake Huron, June 9, 2004

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1010 AM EDT WED JUN 9 2004

.SHORT TERM...
LATEST MESOSCALE ANALYSIS REVEALS FRONTAL BOUNDARY DRAPED ACROSS
NORTHERN LOWER THEN SNAKES SOUTH ACROSS SOUTH CENTRAL LAKE
MICHIGAN...AND JUST ON THE DOOR STEP OF KMKE AT 13Z.  ATMOSPHERE
AHEAD OF THIS FRONT IS QUITE MOIST AND UNSTABLE WITH SURFACE
DEWPOINTS INTO THE LOWER 70S AND INTEGRATED PRECIPITABLE WATERS PER
FSL/S GROUND BASED GPS NEAR 1.50.  MODIFYING 12Z SOUNDING WITH
86/71 SURFACE PARCEL, SHOWS CAPES NEAR 4500 J/KG WITH LI/S TO -10C.
THE WET BULB AND FREEZING LEVELS ARE STILL QUITE HIGH BETWEEN
12K-13K FEET BUT ARE EXPECTED TO SLOWLY DROP DURING THE AFTERNOON AS
THE SURFACE COLD FRONT APPROACHES.  HEAVY RAINFALL POTENTIAL STILL
EXISTS AS STORM MOTION WILL BE SLOW PER CORFIDI VECTORS.

CURRENTLY, WE ARE IN THE WAKE OF THE EARLY MORNING MCS (NEARLY
STATIONARY LAST NIGHT) WITH 1KM HI-RES VISIBLE SHOWING NOTHING MORE
THAN CI/CS ACROSS THE LOWER STATE.  LAPS DATA CURRENTLY HAS HIGH
CONVECTIVE INHIBITIONS BUT WITH AMPLE SUNSHINE, WE SHOULD ERODE THE
SURFACE CAP IN THE NEXT COUPLE OF HOURS WITH CONVECTIVE TEMPS
BETWEEN 83-85F.  WIND FIELD REMAINS WEAK PER LATEST RUC AS MODEL
REVEALS THE POTENTIAL FOR LAKE BREEZE DEVELOPMENT AND PERHAPS FOCUS
MECHANISM FOR THIS AFTERNOON...IN ADDITIONAL TO WHAT DEVELOPS ALONG
THE COLD FRONT.  WE REMAIN IN A SLIGHT RISK AND GIVEN THE DEGREE OF
INSTABILITY, CAN NOT RULE OUT SEVERE WEATHER...ALTHOUGH BEST SHEAR
REMAINS WELL BEHIND THE FRONTAL BOUNDARY.

WE WILL REFRESH THE GRIDS AND HWO.

BGM

&&

.UPDATE...ISSUED AT 720 AM EDT

WILL UPDATE TO LESSEN THUNDERSTORM CHANCES THIS MORNING AS CAP IS
HOLDING STRONG ACROSS CWA. THIS LEADS TO CHANCE WORDING NORTH TO
ISOLATED SOUTH. STILL LOOKS DECENT FOR ACTIVITY THIS AFTERNOON AND
EVENING...ALTHOUGH OVERALL ORGANIZATION IS SOMEWHAT IN QUESTION.
REMNANTS OF OVERNIGHT MCS(S) FROM WI INTO WESTERN LOWER MI SEEMS
TO BE DISRUPTING FLOW. ACTUALLY...CONFLUENT UPPER FLOW HAS SET UP
IN FAR SOUTHERN LOWER MI...ON CUSP OF MESOSCALE HIGH FROM STORMS
AND WAVE LIFTING INTO OHIO VALLEY. THIS MAY MESS THINGS UP A BIT
IN THIS PREFERRED AREA (SW LOWER) AREA OF CONVECTIVE INITIATION.
THAT SAID...IT APPEARS FROM INITIAL VISIBLE SATELLITE IMAGES THAT
THERE WILL BE A FAIR AMOUNT OF SUN IN THIS REGION THIS MORNING...
LEADING TO RATHER RAPID DESTABILIZATION WITH DEW POINTS ALREADY
AROUND 70 F. BOTTOM LINE...RATHER VIGOROUS...ALBEIT DISORGANIZED
CONVECTION STILL EXPECTED DURING LATER 1/2 OF THE DAY.

&&

.PREV DISCUSSION...ISSUED AT 415 AM EDT

00Z RAOBS/WATER VAPOR LOOP SHOW UPPER RIDGE OVER THE EASTERN
CONUS...WITH UPPER LOWS OVER NORTHERN QUEBEC AND THE WEST COAST.
OBSERVED +110KT 300MB JET EXTENDS ACROSS SOUTHERN CANADA BETWEEN
THESE SYSTEMS. SURFACE ANALYSIS SHOWS COLD FRONT HAS DROPPED INTO
NORTHERN LOWER...EXTENDING FROM QUEBEC TO COLORADO. REGIONAL RADARS
SHOW CONVECTION MAINLY ELEVATED BEHIND THE FRONT FROM SOUTH DAKOTA
TO WISCONSIN...WITH STORMS DEVELOPING AHEAD OF IT FROM WESTERN LOWER
TO NORTHERN HURON.

MAIN FOCUS WITH THIS PACKAGE CONTINUES TO BE WITH PRECIP/SEVERE
CHANCES ASSOCIATED WITH THE COLD FRONT. ETA/GFS ARE STILL SOMEWHAT
SIMILAR WITH THE OVERALL PATTERN...BUT FEATURE TIMING DIFFERENCES
THAT IMPACT PRECIP CHANCES ACROSS SOUTHEAST MICHIGAN. SURFACE FRONT
DROPS SOUTH OF THE STATE BY 12Z THURSDAY AS HIGH PRESSURE BUILDS
INTO NORTHERN ONTARIO. ETA IS A BIT STRONGER/FARTHER SOUTH WITH THE
SURFACE HIGH...BUT NOT MUCH DIFFERENCE WITH THE PLACEMENT OF COLD
FRONT. BIG DIFFERENCES WITH THE WAY THE TWO MODELS HANDLE CONVECTION
ALONG THE FRONT THOUGH...WHICH LEAD TO ADDITIONAL DIFFERENCES IN
PLACEMENT/SPEED LATER IN THE PERIOD.

FOR TODAY...SURFACE FRONT WILL SLOWLY DROP SOUTH INTO THE CWA.
BOUNDARY IS NOT ALL THAT WELL DEFINED...WITH ONLY WEAK LOW LEVEL
CONVERGENCE ALONG IT. HOWEVER THERE IS ENOUGH INSTABILITY CURRENTLY
AVAILABLE TO GET STORMS GOING AHEAD OF IT. 03Z RUC ANALYSIS/FORECAST
SHOW THE CAP IN PLACE EARLIER WEAKENING ACROSS WESTERN LOWER...BUT
STILL TRYING TO HOLD ON ACROSS THE SOUTHEAST. 600MB TEMPS ONLY
SLOWLY DROP FROM 2C ACROSS THE CWA...WHICH COULD EXPLAIN WHY STORMS
ARE HAVING SUCH A HARD TIME MAKING IT EASTWARD. HOWEVER AS A
SHORTWAVE OVER THE MID MISSISSIPPI VALLEY APPROACHES THIS MORNING
AND HEIGHTS CONTINUE TO FALL...WE SHOULD SEE STORMS CONTINUE TO
EXPAND ACROSS THE CWA. WILL START WITH NUMEROUS TSRA IN THE NORTH
WHERE STORMS ARE TRYING TO FIRE NEAR THE FRONT...AND START WITH
SCATTERED IN THE SOUTH. A FEW CELLS ARE TRYING TO DEVELOP ACROSS THE
SOUTHERN CWA...HENCE THE CHANCE POPS INITIALLY. WILL THEN KEEP
LIKELY POPS ACROSS THE CWA DURING THE AFTERNOON WITH BETTER
INSTABILITY/DROPPING HEIGHTS AND THE SURFACE FRONT APPROACHING.

SEVERE WEATHER CONTINUES TO BE A POTENTIAL PROBLEM FOR TODAY. LAPSE
ANALYSIS STILL INDICATES OVER 1000J/KG CAPE OVERNIGHT...WHICH WILL
ONLY INCREASE DURING THE DAY. IR SATELLITE SHOWS SOME CLEAR BREAKS
UPSTREAM ACROSS NORTHERN ILLINOIS/SOUTHERN LAKE MICHIGAN. CONVECTIVE
DEBRIS IS MAINLY TRACKING EAST ACROSS THE NORTHERN CWA. WE SHOULD
SEE SOME SUN THIS MORNING ACROSS THE SOUTHERN CWA...WHICH COULD HELP
TO PROPEL TEMPS INTO THE UPPER 80S AGAIN. DEWPOINTS ARE STILL
RUNNING IN THE LOW 70S...WHICH WILL LEAD TO OVER 2000J/KG CAPE/LIS
DOWN TO -5C. WIND FIELD IS STILL PRETTY MARGINAL...ALTHOUGH 0-6KM
SHEAR INCREASES TO 30M/S BY AFTERNOON. 850MB JET ALSO PICKS
UP...WITH LOW-LEVEL WINDS AROUND 30KTS. COULD SEE SOME MULTICELL
STORMS...ALTHOUGH IT LOOKS LIKE MAIN THREAT WILL BE FROM PULSE
SEVERE. WIND/HAIL BOTH LOOK POSSIBLE...EVEN WITH FREEZING LEVELS UP
TO 14-15KFT. STORM MOTION IS LESS THAN 20KTS...AND ORIENTATION TO
INFLOW SUPPORTS BACKBUILDING/TRAINING ECHOES...WITH LOCALIZED
FLOODING CONCERNS. FORECAST PRECIPITABLE WATERS INCREASE TO ABOUT
1.75 INCHES /ABOUT 200 PERCENT OF NORMAL AT DTX/...SIMILAR TO WHAT
WAS OBSERVED UPSTREAM AT GRB/MPX LAST NIGHT.

FOR TONIGHT...MODEL DIFFERENCES START TO BECOME APPARENT. ETA
CONTINUES TO DEVELOP CONVECTION ON THE BACK SIDE OF THE
FRONT...SIMILAR TO WHAT HAS BEEN OBSERVED UPSTREAM OVERNIGHT...AND
KEEPS IT GOING ACROSS THE CWA FOR MUCH OF THE NIGHT. GFS ON THE
OTHER HAND DEVELOPS AN ORGANIZED COMPLEX ACROSS THE MID MISSISSIPPI
VALLEY THIS EVENING...WHICH CUTS OFF THE MOISTURE FEED INTO THE
STATE AND CONSEQUENTLY SHOWS VERY LITTLE PRECIP ALONG THE FRONT.
GIVEN WHAT IS OBSERVED UPSTREAM...WILL KEEP LIKELY POPS GOING
TONIGHT...EVENING NORTH/ALL NIGHT SOUTH.

SURFACE FRONT DROPS SOUTH OF THE STATE ON THURSDAY. HOWEVER 850MB
FRONT LINGERS BACKS NEAR THE SOUTHERN CWA. WITH SOME ADDITIONAL
MOISTURE AVAILABLE...ADDITIONAL CONVECTION COULD DEVELOP ALONG THE
ELEVATED FRONT. WILL KEEP CHANCE POPS GOING ACROSS THE SOUTHERN HALF
OF THE CWA THURSDAY...AND CUT BACK FARTHER SOUTH THURSDAY NIGHT.
THURSDAY NIGHT IS VERY MARGINAL...ALTHOUGH THE GFS DOES TRY TO
DEVELOP ALONG COMPLEX...WHICH SHOULD BRUSH THE FAR SOUTHERN CWA. ETA
IS SOMEWHAT SIMILAR WITH ITS LOW-LEVEL JET...HOWEVER INSTEAD
DEVELOPING STORMS FARTHER NORTHWEST ACROSS MINNESOTA/WISCONSIN.

FOR THE END OF THE WEEK...UPPER LOW OVER QUEBEC CONTINUES TO SPIN
OVER THE CANADIAN MARITIMES...MAKING VERY SLOW PROGRESS EASTWARD.
WESTERN LOW LIFTS NORTHEAST INTO THE NORTHERN HIGH PLAINS...BECOMING
RATHER BROAD AS SOME ENERGY REMAINS ANCHORED OVER THE WEST.
SHORTWAVE RIDGE BETWEEN THESE TWO SYSTEMS SHORTWAVES AND SHIFTS
ACROSS THE GREAT LAKES. BUILDING HEIGHTS WILL HELP TO DISPLACE THE
BAROCLINIC ZONE BACK TO THE NORTH. BETTER SYNOPTIC LIFT/MOISTURE
FLUX ACROSS THE WESTERN CWA UNDER FALLING HEIGHTS...WITH THIS
ACTIVITY SLOWLY WORKING EASTWARD. ETA/GFS CONTINUE TO HAVE
DIFFERENCES WITH PLACEMENT AND SPEED OF THE FRONT MOVING BACK INTO
THE CWA. HIGH PRESSURE STILL TRIES TO HOLD ON ACROSS NORTHEAST
ONTARIO THROUGH FRIDAY...SO WILL KEEP CHANCE TSRA ACROSS THE
SOUTHWEST CWA...FOLLOWED BY CHANCE EVERYWHERE BEGINNING FRIDAY
NIGHT. CHANCES CONTINUE THROUGH THE WEEKEND AS ACTIVE SOUTHWESTERLY
FLOW SETS UP ACROSS THE REGION.

&&

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

&&

BRAVENDER/GURNEY

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
1057 AM EDT WED JUN 9 2004

MIZ047>049-053>055-101200-
BAY-HURON-MIDLAND-SAGINAW-SANILAC-TUSCOLA-
1057 AM EDT WED JUN 9 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE TRI-CITIES AND THUMB
REGION.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THUNDERSTORMS WILL BECOME MORE NUMEROUS THIS AFTERNOON AND CONTINUE
THROUGH THE EVENING HOURS.  A FEW OF THESE THUNDERSTORMS MAY BECOME
SEVERE WITH PENNY SIZE HAIL AND WIND GUSTS TO 60 MPH.  IN
ADDITION...HEAVY RAINFALL IS EXPECTED WITH THESE THUNDERSTORMS AND
MAY BRING SOME LOCALIZED FLOODING.  THUNDERSTORM MOVEMENT WILL EAST
SOUTHEAST AT 20 MPH. THIS ACTIVITY WILL BE THE RESULT OF A COLD
FRONT THAT WILL SAG SOUTH THROUGH THE AREA THIS AFTERNOON.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THERE WILL BE A CHANCE OF THUNDERSTORMS FRIDAY NIGHT THROUGH MONDAY.
THIS ACTIVITY WILL BE THE RESULT OF A SLOW MOVING SURFACE FRONT AND
A SERIES OF UPPER LEVEL DISTURBANCES.

.SPOTTER INFORMATION STATEMENT...

DISPATCHERS...PLEASE NOTIFY YOUR EMERGENCY MANAGER IMMEDIATELY.
SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING.

MIZ060>063-068>070-075-076-082-083-101200-
GENESEE-LAPEER-LENAWEE-LIVINGSTON-MACOMB-MONROE-OAKLAND-SHIAWASSEE-
ST. CLAIR-WASHTENAW-WAYNE-
1057 AM EDT WED JUN 9 2004

THIS HAZARDOUS WEATHER OUTLOOK IS LOCATIONS ALONG AND SOUTH OF I-69.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THUNDERSTORMS WILL BECOME MORE LIKELY DURING THE AFTERNOON AND
CONTINUE INTO TONIGHT.  SOME OF THESE THUNDERSTORMS MAY BECOME
SEVERE WITH HAIL UP TO 1 INCH AND WIND GUSTS TO 65 MPH.  IN
ADDITION...HEAVY RAINFALL MAY ALSO PRODUCE SOME LOCALIZED FLOODING.
DEVELOPMENT OF THUNDERSTORMS WILL LIKELY OCCUR AFTER 2 PM.
THUNDERSTORMS WILL MOVE EAST AT 20 MPH. THIS ACTIVITY WILL BE THE
RESULT OF A COLD FRONT THAT WILL SAG SOUTH THROUGH THE AREA LATE
THIS AFTERNOON INTO TONIGHT.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THE CHANCE OF SCATTERED THUNDERSTORMS WILL PERSIST ON THURSDAY AND
FRIDAY...WITH MOST OF THE ACTIVITY REMAINING CONFINED TO LOCATIONS
SOUTH OF THE M 59 CORRIDOR. THUNDERSTORMS WILL THEN BECOME MORE
WIDESPREAD ACROSS THE ENTIRE AREA THIS WEEKEND...AND PERSIST INTO
NEXT MONDAY.

THE AFOREMENTIONED COLD FRONT IS EXPECTED TO STALL OVER THE OHIO
VALLEY FOR SEVERAL DAYS...BEFORE RETURNING BACK THROUGH THE AREA
DURING THE WEEKEND...LEADING TO THIS CONTINUATION IN THUNDERSTORM
CHANCES.

.SPOTTER INFORMATION STATEMENT...

DISPATCHERS...PLEASE NOTIFY YOUR EMERGENCY MANAGER IMMEDIATELY.
SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON INTO TONIGHT.

BGM

HTTP://WWW.CRH.NOAA.GOV/DTX  (ALL LOWER CASE)