High Wind in Michigan, February 25, 2001

SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
350 AM EST SUN FEB 25 2001

RAIN WILL DIMINISH TO SCATTERED SHOWERS BY 8 AM AROUND SE MICHIGAN,
THEN END FOR A WHILE DURING THE LATE MORNING. WILL CONTINUE THE
URBAN AND SMALL STREAM FLOOD ADVISORY UNTIL ABOUT 8 AM AS THINGS
DRAIN OFF A LITTLE MORE. WILL ALSO BE KEEPING AN EYE ON MAIN RIVER
LEVELS AS THE FROZEN GROUND WILL ALLOW A LOT OF RUN OFF.

IMPRESSIVE DRY SLOT WILL TAKE OVER FROM THERE AND ATTENTION TURNS
QUICKLY TO THE WIND POTENTIAL FOR TODAY. SURFACE ANALYSIS SHOWED THE
00Z MODEL RUNS WHERE CLOSE, IF NOT A COUPLE OF MILLIBARS TOO WEAK,
AS THE SYSTEM MOVED INTO THE WESTERN GREAT LAKES. ALL OF THE MODELS
TRACK IT THROUGH EASTERN LAKE SUPERIOR AND INTO ONTARIO BY THIS
EVENING. DURING THIS TIME THEY DROP THE CENTRAL PRESSURE AT LEAST 5
MB, WITH THE ETA DROPPING IT CLOSE TO 10 MORE BY 18Z. THE ETA MAY BE
A LITTLE OVERDONE, BUT SURFACE OBS ALREADY SUPPORT SUSTAINED 25 TO
35 MPH WIND AT PRESS TIME BEHIND THE COLD FRONT, SO EVEN THE 5 MB
DEEPENING WILL JUST ADD TO THE GRADIENT FLOW. IN ADDITION, FWC WIND
GUIDANCE IS REALLY UP THERE WITH SUSTAINED WIND AROUND 25 KNOTS AT
FLINT AND MAXING OUT AT 32 KNOTS THIS AFTERNOON AT DETROIT. SO THERE
IS GOOD SUPPORT FOR A HIGH WIND WIND ADVISORY IN ALL OF SE LOWER,
ESPECIALLY IN LIGHT OF TREE LIMBS THAT WERE WEAKENED BY ICE
ACCUMULATION YESTERDAY. PLAN TO BEGIN THE HEADLINE THIS AFTERNOON
AND CONTINUE IT THROUGH THIS EVENING.

IN ADDITION TO THE GRADIENT WIND, LINGERING CONVECTIVE POTENTIAL
WILL COMPLICATE MATTERS BY ADDING A GUST COMPONENT WITH 850 FLOW
CONTINUING IN THE 40 TO 60 KNOT RANGE. THE BEST CHANCE FOR
SHOWERS, AND POSSIBLY A THUNDERSTORM, WILL BE ON THE LEADING EDGE OF
THE WRAP AROUND MOISTURE AND ALONG THE FRONT. IN THIS REGION, THE
850 TO 500 MB LAPSE RATE WILL BE PUSHING 30 AND 850 DEWPOINTS WILL
STILL BE AROUND 2C. THIS PART OF THE SYSTEM BRUSHES THROUGH THE
SAGINAW VALLEY THIS MORNING AND THAT IS WHERE SHOWERS WILL BE
LIKELY, ESPECIALLY WITH ANY DIURNAL COMPONENT THAT CAN DEVELOP.
PRECIPITATION CHANCES THEN DIMINISH TO THE SOUTH AS UPPER SUPPORT
WANES TOWARD OHIO, BUT FRONTAL CONVERGENCE AND ANY ADDED INSTABILITY
FROM DAYTIME HEATING WILL NOT ALLOW US TO RULE OUT THUNDER IN THE
SOUTH SECTIONS AS WELL. THE DIURNAL COMPONENT WILL PLAY A GREATER
ROLE IN THE SOUTH PART OF OUR AREA AS CLEAR SKY IS SHOWING UP IN THE
DRY SLOT OVER ILLINOIS AT PRESS TIME.

THE FRONT WILL BE THROUGH SE MICHIGAN SHORTLY AFTER 18Z AND THEN
SYNOPTIC SCALE SUBSIDENCE WILL TAKE OVER AND BRING THE BEST CHANCE
OF STRONG WIND GUSTS TO A WIDER AREA. STRONG AND DEEP LAYER COLD
ADVECTION WILL GIVE FORECAST 850 MB WINDS AROUND 50 KNOTS A GOOD
CHANCE OF MAKING IT TO THE SURFACE. THE ETA LOOKS THE MOST INTENSE
WITH DOWNWARD OMEGA REACHING 5 UB BY 00Z OVER LOWER MICHIGAN, AND
HELPING JUSTIFY THE WIND ADVISORY FOR THIS EVENING. PEAK WIND GUSTS
AROUND 50 MPH AT SOME OF THE AIRPORTS SEEM REACHABLE.

THE WIND WILL DIMINISH AFTER MIDNIGHT AS THE GRADIENT RELAXES AND
SUBSIDENCE DECREASES. OUTSIDE OF A CHANCE OF SNOW SHOWERS IN THE
SAGINAW VALLEY, JUST BROKEN CLOUDS WILL BE LEFT OVER TOWARD SUNRISE
MONDAY. A WEAK CLIPPER WILL BRING AN ADDITIONAL SURGE OF COOLER AIR
DURING THE AFTERNOON, THEN HIGH PRESSURE WILL HELP DECREASE THE
CLOUDS HEADING INTO MONDAY NIGHT.

.DTX...URBAN AND SMALL STREAM FLOOD ADVISORY...UNTIL 8 AM...
       ALL OF SE MICHIGAN
       HIGH WIND ADVISORY...THIS AFTERNOON AND THIS EVENING...
       ALL OF SE MICHIGAN
       STORM WARNING...THIS AFTERNOON AND TONIGHT...LAKE HURON
       GALE WARNING...THIS AFTERNOON AND TONIGHT...LAKE ST CLAIR.

BT

MIZ047>049-053>055-060>063-068>070-075-076-082-083-251700-

SEVERE WEATHER OUTLOOK FOR SOUTHEAST MICHIGAN
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
615 AM EST SUN FEB 25 2001

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

DISPATCHERS...PLEASE NOTIFY YOUR EMERGENCY MANAGERS IMMEDIATELY.

THERE IS A CHANCE OF SHOWERS...WITH A THUNDERSTORM POSSIBLE...
DURING THE LATE MORNING AND EARLY AFTERNOON HOURS ACROSS ALL OF
SOUTHEAST MICHIGAN. THIS ACTIVITY COULD PRODUCE SEVERE WIND GUSTS...
AND MAY REQUIRE SPOTTER ACTIVATION.

A STRONG COLD FRONT WILL CROSS SOUTHEAST MICHIGAN DURING THE LATE
MORNING AND EARLY AFTERNOON HOURS. THE WIND IS VERY STRONG WITH THIS
LOW PRESSURE SYSTEM...ESPECIALLY A FEW THOUSAND FEET ABOVE THE
GROUND. AS THE FRONT MOVES THROUGH THE AREA...THERE IS A CHANCE THAT
SHOWERS WILL DEVELOP...WITH A THUNDERSTORM ALSO POSSIBLE. BECAUSE
THE WIND IS SO STRONG WITH THIS SYSTEM...EVEN A HEAVY RAIN SHOWER
COULD HELP PULL DAMAGING WIND GUSTS TO THE GROUND. A THUNDERSTORM
WILL HAVE THE POTENTIAL TO PRODUCE WIND GUSTS NEAR 60 MPH AND WOULD
MOVE NORTHEAST AT ABOUT THE SAME PACE.

THE SPEED OF THE COLD FRONT WILL LIMIT THE THUNDERSTORM CHANCE TO
BETWEEN 11 AM AND 2 PM. AFTER THAT, THE TEMPERATURE WILL BEGIN
FALLING, BUT THE STRONG WIND WILL CONTINUE INTO THIS EVENING. A HIGH
WIND ADVISORY IS IN EFFECT FOR THIS PROLONGED PERIOD OF STRONG WIND.

STAY TUNED TO NOAA WEATHER RADIO...OR YOUR LOCAL RADIO...
TELEVISION...OR CABLE TELEVISION STATION...FOR LATER FORECAST
UPDATES.

BT