247
FXUS63 KDTX 110817 CCA
AFDDTX
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
417 AM EDT WED MAR 11 2026
KEY MESSAGES
- A FLOOD WATCH IS IN EFFECT FOR SOUTHERN PARTS OF SOUTHEAST MI
THROUGH EARLY AFTERNOON. ADDITIONAL ROUNDS OF SHOWERS AND STORMS ARE
EXPECTED THROUGH THE DAY AND MAY PRODUCE HEAVY RAINFALL.
- A WINTER WEATHER ADVISORY IS IN EFFECT FOR THE TRI CITIES REGION
AND NORTHERN THUMB THIS MORNING DUE TO FREEZING RAIN. ICE
ACCUMULATIONS OF UP TO 0.10 INCH IS EXPECTED TO RESULT IN TRAVEL
IMPACTS EARLY THIS MORNING.
- ACCUMULATING SNOW IS LIKELY FRIDAY MORNING AND STRONG WINDS IN
EXCESS OF 40 MPH ARE POSSIBLE DURING THE DAY FRIDAY.
- ANOTHER ROUND OF ACCUMULATING SNOW AND STRONG WINDS IS
INCREASINGLY LIKELY SATURDAY NIGHT THROUGH SUNDAY.
DISCUSSION
AN EARLIER LINE OF ELEVATED CONVECTION IS EXITING THE AREA WITH THE
STALLED SURFACE FRONT NOW POSITIONED OVER NORTHWEST OHIO. SEVERE
THREAT THROUGH THE REST OF THE EARLY MORNING IS LOW AS THE RAIN-
COOLED OUTFLOW AND NORTHEAST WIND SHOULD HOLD THE SURFACE BASED
INSTABILITY SOUTH. 40-50 KT WSW FLOW NOTED IN KDTX VWP DATA
CONTINUES TO ADVECT A FEED OF ANOMALOUS MOISTURE INTO THE ELEVATED
FRONTAL SLOPE. PWAT ANALYZED AT 1.30" IS NEAR THE DAILY MAX IN SPC
RAOB CLIMATOLOGY. AS THE LLJ PASSES OVERHEAD EARLY THIS MORNING,
EXPECT THE FLARE-UP OF CONVECTION OVER NORTHERN IN TO SPREAD
NORTHEAST ACROSS THE SOUTHERN FORECAST AREA THROUGH MIDDAY. OPTED TO
ISSUE A FLOOD WATCH FOR THIS AREA GIVEN HEAVY RAINFALL ALREADY
RECEIVED, WEAK ELEVATED INSTABILITY, AND INCREASED LIKELIHOOD FOR
TRAINING STORMS AS CORFIDI VECTOR MAGNITUDE FALLS BELOW 10 KT. HI-
RES ENSEMBLE DATA OFFERS 50% CONFIDENCE FOR AREAS TO RECEIVE OVER 2"
OF RAIN, WHICH IS HIGHER THAN CURRENT FLASH FLOOD GUIDANCE. THIS
SUGGESTS HIGHER POTENTIAL FOR FLOODING ISSUES IN URBAN AREAS AND
ALONG SMALL STREAMS. AREAS LEFT OUT OF THE WATCH ARE NOT EXPECTED TO
SEE AS MUCH ADDITIONAL RAINFALL FROM THE NEXT ROUND.
AUTOMATED OBSERVATIONS OVERNIGHT INDICATED INTERVALS OF FREEZING
RAIN ACROSS THE SAGINAW VALLEY AND NORTHERN THUMB, WITH DEW POINTS
THERE STILL HOLDING IN THE LOWER 30S. WIDESPREAD PRECIP IS DEPARTING
THE AREA BUT WITH THE ADDITIONAL PRECIP EXPECTED LATER THIS MORNING,
WILL KEEP THE WINTER WEATHER ADVISORY GOING. IT IS POSSIBLE THAT
TEMPERATURES AND DEW POINTS RISE COMFORTABLY ABOVE FREEZING THIS
MORNING IN WHICH CASE THE ADVISORY MAY BE CANCELED EARLY.
ADDITIONAL PVA LIFTS NE INTO THE AREA TODAY AHEAD OF THE INBOUND MID-
LEVEL TROUGH THAT PASSES OVERHEAD LATE TONIGHT. THE SURFACE LOW OVER
SW LOWER IS PROGGED TO TRACK NE FROM TO NEAR THE ST. CLAIR RIVER BY
18Z, WITH THE WARM SECTOR BRIEFLY SPREADING UP INTO THE METRO
DETROIT VICINITY BETWEEN 15 AND 18Z. POOR LAPSE RATES NEAR MOIST
ADIABATIC WILL LIMIT SEVERE POTENTIAL BUT CAN'T RULE OUT ISOLATED
GUSTY WINDS AS THE LLJ CLIPS FAR SE MI. AS THE LOW TRACKS THROUGH,
BACKSIDE DEFORMATION FORCING SUSTAINS ANOTHER ROUND OF SHOWERS
BEFORE DRIER AIR ARRIVES FROM THE NORTHWEST THROUGH THE AFTERNOON.
THERE MAY BE A COUPLE HOUR WINDOW FOR LIGHT WINTRY MIX AS
TEMPERATURES FALL INTO THE 30S FROM NW TO SE. IMPACTS ARE NOT
ANTICIPATED AS ANY PRECIP WILL BE LIGHT. COOLER CONDITIONS IN THE
20S TONIGHT LEAD INTO A SEASONABLE DAY THURSDAY AS UPPER LEVEL
CONFLUENCE WITHIN A RISING HEIGHT FIELD SUSTAINS MAINLY DRY
CONDITIONS.
THE NEXT NORTHERN STREAM WAVE ARRIVES FRIDAY MORNING, AMPLIFYING
UPSTREAM WITH AN IMPRESSIVE CORRIDOR OF HEIGHT FALLS AND PVA
TARGETING SOUTHERN LOWER MI. THIS KICKS OFF DEEP LAYER ISENTROPIC
ASCENT TO PRODUCE A QUICK HITTING BURST OF PRECIP OVERNIGHT INTO THE
FRIDAY MORNING COMMUTE - CURRENT TIMING IS LINED UP BETWEEN ABOUT
MIDNIGHT AND 8AM. TEMPS IN THE UPPER 20S TO LOWER 30S AT ONSET FAVOR
SNOW INITIALLY BEFORE WARM ADVECTION IN THE LOW LEVELS BRINGS
POTENTIAL FOR A CHANGEOVER TO RAIN BY MID-MORNING. LATEST ENSEMBLE
GUIDANCE SUPPORTS A GENERAL 1 TO 3 INCH WET SNOWFALL MAINLY ALONG
AND NORTH OF I-69, BUT POSSIBLY INTO THE HIGHER TERRAIN ALONG THE
GLACIAL RIDGE AS WELL. AREAS FARTHER SOUTH ARE MORE POISED FOR A
DUSTING.
HIGH CONFIDENCE EXISTS IN A PERIOD OF STRONG WINDS FRIDAY AFTERNOON
AS THE HIGHLY DYNAMIC SYSTEM TRACKS ACROSS THE NORTHERN GREAT LAKES.
AN IMPRESSIVE GRADIENT AND STRONG SUBSIDENCE/COLD ADVECTION PRODUCE
40+ MPH WINDS AND MAY WARRANT A HEADLINE. THE NEXT ROUND OF HIGHER
IMPACT WEATHER CONTINUES TO COME INTO FOCUS FOR THE SUNDAY AND
MONDAY PERIOD. GUIDANCE HAS BEEN CONSISTENT ON DEPICTING A VIGOROUS
DIGGING WAVE INDUCING STRONG SYNOPTIC ASCENT DIRECTLY OVER THE GREAT
LAKES AS IT TAKES ON A NEGATIVE TILT. ISENTROPIC ASCENT RAMPS UP
SATURDAY NIGHT TO PRODUCE A BAND OF SNOW OVER LOWER MI BEFORE THE
SURFACE LOW TRACKS ACROSS THE AREA LATE SUNDAY. DEPENDING ON ITS
TRACK, HEAVY PRECIP AND STRONG WIND WILL BE POSSIBLE.
MARINE
WIDESPREAD RAIN AND EMBEDDED THUNDERSTORMS CONTINUE TODAY AS LOW
PRESSURE TRACKS ALONG A FRONTAL BOUNDARY FROM SOUTHERN LAKE MICHIGAN
TOWARD SOUTHERN LAKE HURON. CYCLONIC FLOW AROUND THE LOW TRANSITIONS
TO BROADER NORTHWEST FLOW TONIGHT THAT INTRODUCES 30+ KNOT GUST
POTENTIAL AS COLD ADVECTION RAMPS UP, ALBEIT BRIEF DURATION. ACTIVE
STRETCH OF WEATHER CONTINUES FOR THE LATTER HALF OF THE WEEK, WITH A
RETURN TO WINTRY CONDITIONS. INCREASING CONFIDENCE IN GALE POTENTIAL
FOR FRIDAY AS STRONG LOW PRESSURE TRACKS ACROSS THE GREAT LAKES,
ALONGSIDE WINTRY PRECIPITATION.
HYDROLOGY
A FLOOD WATCH IS IN EFFECT FOR COUNTIES ALONG AND SOUTH OF M-59, AS
WELL AS SOUTHERN ST. CLAIR COUNTY, THROUGH EARLY AFTERNOON.
ADDITIONAL THUNDERSTORMS ARE FORECAST TO TRACK OVER AREAS THAT
RECEIVED HEAVY RAINFALL OVERNIGHT. THERE IS POTENTIAL FOR TRAINING
STORMS AND HEAVY RATES OF OVER 1" PER HOUR TO LEAD TO FLOODING
CONCERNS ESPECIALLY WITHIN LOW-LYING AND URBAN AREAS. 50% CONFIDENCE
EXISTS FOR LOCALIZED STORM TOTAL AMOUNTS OF OVER 2". RISES ON AREA
RIVERS ARE EXPECTED ACROSS SOUTHEAST MI OVER THE NEXT FEW DAYS GIVEN
THE WIDESPREAD MODERATE TO HEAVY RAINFALL SINCE LAST EVENING.
PREV DISCUSSION
ISSUED AT 1214 AM EDT WED MAR 11 2026
AVIATION...
THE UPSTREAM CLUSTER OF SHOWERS AND THUNDERSTORMS WILL TRACK ACROSS
SE MI DURING THE PRE DAWN HOURS. ADDITIONAL SHOWERS WITH SOME
EMBEDDED THUNDERSTORMS WILL PERSIST THROUGH WED MORNING AND INTO THE
EARLY AFTERNOON ALONG/IN ADVANCE OF A SURFACE LOW LIFTING NORTHWARD
ALONG A COLD FRONT. CEILINGS WILL UNDERGO WIDE VARIABILITY DURING
THE MORNING HOURS AS LOW LEVEL MOISTURE CONTINUES TO ADVECT INTO A
RESIDUAL COOL LAKE MODIFIED BOUNDARY LAYER ACROSS SE MI. THE PASSAGE
OF THE SFC LOW AND COLD FRONT BETWEEN 15Z AND 18Z WILL RESULT IN A
VEERING OF THE WINDS TO THE WEST-NORTHWEST. POST FRONTAL COLD AIR
ADVECTION WILL ALLOW WIND SPEEDS/GUSTS TO INCREASE STEADILY DURING
THE AFTERNOON AND EVENING, POSSIBLY PEAKING OVER 25 KNOTS AT TIMES.
FOR DTW...UPSTREAM RADAR SUGGESTS NUMEROUS THUNDERSTORMS TRACKING
ACROSS THE METRO AIRSPACE BETWEEN 07Z AND 11Z. ISOLATED TO SCATTERED
THUNDERSTORM MAY THEN OCCUR IN ADVANCE OF THE COLD FRONT DURING THE
MID TO LATE MORNING HOURS. CONFIDENCE ON THE LATER MORNING
CONVECTION IS LOW AT THIS TIME.
DTW THRESHOLD PROBABILITIES...
* HIGH FOR CEILINGS AT OR BELOW 5000 FEET THROUGH THE FORECAST.
* HIGH FOR THUNDERSTORMS EARLY THIS MORNING. LOW AFTER 12Z.
DTX WATCHES/WARNINGS/ADVISORIES
MI...WINTER WEATHER ADVISORY UNTIL 10 AM EDT THIS MORNING FOR MIZ047>049-
053-054.
FLOOD WATCH UNTIL 2 PM EDT THIS AFTERNOON FOR MIZ063-068>070-075-
076-082-083.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THURSDAY FOR LHZ421-441.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 4 PM EDT THURSDAY
FOR LHZ442-443.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
DISCUSSION...TF
MARINE.......MV/TF
HYDROLOGY....TF
AVIATION.....SC
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AT WWW.WEATHER.GOV/DETROIT.
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