Flood in Michigan, February 9 to 14, 2001

SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1125 AM EST FRI FEB 9 2001

CONCERNS THIS AFTERNOON WILL BE SEVERE WEATHER POTENTIAL AND FLOOD
THREAT.

ONGOING RAIN SHOWERS.../NO THUNDER IN CWA SINCE JUST BEFORE SUNRISE/
CONTINUE ACROSS CWA. SHOWER ACTIVITY LINES UP VERY WELL WITH AXIS OF
850 MB THETA-E FIELD AND ASSOCIATED ADVECTION AS DEPICTED ON 12Z
MESOETA. TRAILING EDGE OF SHOWERS NOW MAKING WAY THROUGH SAGINAW
COUNTY LINES UP WELL WHERE 850MB THETA-E ADVECTION TRANSITIONS TO
NEUTRAL ADVECTION. AXIS OF ELEVATED INSTABILITY...WITH RUC 800MB
LI/S SHOWING BEST INSTABILITY...TRANSITIONS SOUTH ACROSS CWA THIS
AFTERNOON WITH BEST INSTABILITY CONFINED TO FAR SOUTHEAST COUNTIES.
CONVECTION IN ILLINOIS THAT PROMPTED SEVERE THUNDERSTORM WATCH FOR
IL/IN APPEARS TO BE DEVELOPING ALONG COLD FRONT. THAT WILL BE
CONCERN FOR THIS AFTERNOON AND EVENING AS COLD FRONT MAKES ITS WAY
ACROSS CWA. TIMING ON FROPA LOOKS TO BE EARLY TO MID AFTERNOON
NORTH...MID TO LATE AFTERNOON CENTRAL...AND EARLY EVENING SOUTH.
DESPITE FAIRLY POTENT SHOWERS THIS MORNING...HAVE NOT BE ABLE TO MIX
DOWN ANY OF THE HIGH MOMENTUM AIR TO THE SURFACE...KDTX 88D SHOWING
50 TO 60 KNOTS JUST 1000 FEET OFF THE SURFACE. WITH BETTER
CONVERGENCE ALONG THE FRONT...MAY SEE SOME OF THAT HIGHER MOMENTUM
AIR MAKE IT TO THE SURFACE...AND IT MAY DO SO WITH OR WITHOUT
THUNDER. WILL OF COURSE ALSO NEED TO WATCH EVOLVING LINE IN IL TO
SEE IF IT SHOWS ANY NORTHWARD DRIFT.

IN TERMS OF RIVER FLOODING...NO CONCERNS SEEN NOW WITH LATEST
GUIDANCE FROM THE RFC SHOWING ALL RIVERS TO REMAIN BELOW FLOOD
STAGE. HAVE RECENTLY RECEIVED SPOTTER REPORTS OF URBAN-TYPE FLOODING
IN LAPEER AND TUSCOLA COUNTIES. GIVEN THESE REPORTS AND EXPECTED
HEAVIER RAINFALL TO PERSIST ACROSS CWA.../NOTE MINI DRY SLOT ACROSS
NORTHERN CWA...BUT RAINFALL ALREADY FILLING IN AGAIN TO THE
WEST/...THROUGH THE AFTERNOON AND EVENING.

WILL NOT MAKE CHANGES TO TEMPERATURES. WILL NEED SOME BREAKS IN THE
RAIN...TO REACH FORECAST MAX TEMPS...BUT STILL THINK MAX TEMPS
REACHABLE.

.DTX...GALE WARNING LAKE HURON...THIS AFTERNOON AND TONIGHT.
       GALE WARNING LAKE ST CLAIR...THIS AFTERNOON AND EVENING
       URBAN AND SMALL STREAM FLOOD ADVISORY ENTIRE CWA THIS AFTERNOON.

OKEEFE

MIZ047>049-053>055-060>063-068>070-075-076-082-083-091200-

SEVERE WEATHER OUTLOOK FOR SOUTHEAST LOWER MICHIGAN
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1152 AM EST THU FEB 8 2001

...SEVERE WEATHER POTENTIAL STATEMENT FOR SOUTHEAST MICHIGAN...

DISPATCHERS...PLEASE NOTIFY YOUR EMERGENCY MANAGERS IMMEDIATELY.

ISOLATED THUNDERSTORMS ARE POSSIBLE ACROSS SOUTHEAST LOWER MICHIGAN
THIS AFTERNOON AND EVENING. ONE OR TWO OF THESE THUNDERSTORMS MAY
BECOME SEVERE AND SPOTTER ACTIVATION MAY BE NECESSARY.

IN ADDITION TO THE THUNDERSTORM THREAT...HEAVY RAIN WILL CAUSE
PONDING OF WATER ON AREA ROADS AND IN LOW LYING AREAS. DRAINAGE WILL
BE POOR IN THOSE AREAS WHERE SNOW STILL COVERS OPENINGS TO STORM
SEWERS. TO ACCOUNT FOR THIS SCENARIO...AN URBAN AND SMALL STREAM
FLOOD ADVISORY HAS BEEN ISSUED. MOTORISTS SHOULD BE ALERT FOR
STRETCHES OF WATER OVER ROADWAYS...ESPECIALLY IN URBAN AREAS.

LOW PRESSURE WILL TRACK NORTHEAST ACROSS LOWER MICHIGAN TODAY...
PULLING A STRONG COLD FRONT ACROSS THE REGION THIS AFTERNOON AND
EVENING. THUNDERSTORMS ARE POSSIBLE AHEAD OF AND ALONG THE COLD
FRONT. THE GREATEST THREAT FOR A SEVERE THUNDERSTORM TO DEVELOP
LOOKS TO BE ALONG THE FRONT. THEREFORE...THE GREATEST THREAT FOR A
SEVERE THUNDERSTORM IN THE SAGINAW VALLEY AND THUMB WILL BE BETWEEN
NOON AND 4 PM...AND 2 PM TO 8 PM FOR POINTS FROM METRO FLINT
SOUTH...INCLUDING METRO DETROIT.

ANY SEVERE THUNDERSTORMS THAT DEVELOP WILL MOVE NORTHEAST AT 50 MPH.
THE GREATEST THREAT FROM THESE STORMS WILL BE WIND GUSTS TO 60 MPH.

STAY TUNED TO NOAA WEATHER RADIO...OR YOUR LOCAL RADIO...
TELEVISION...OR CABLE TELEVISION STATION...FOR ALL OF YOUR WEATHER
INFORMATION.

OKEEFE/TILLEY