895
FXUS63 KDTX 201745
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
145 PM EDT MON JUL 20 2026
KEY MESSAGES
- A STATEWIDE AIR QUALITY ALERT IS IN EFFECT THROUGH TODAY WITH LINGERING
WILDFIRE SMOKE ACROSS MICHIGAN.
- SHOWERS AND THUNDERSTORMS TONIGHT WILL POSE AN ISOLATED RISK FOR
SEVERE WEATHER.
- ADDITIONAL SCATTERED SHOWERS AND THUNDERSTORMS ON TUESDAY, THEN MOSTLY
DRY CONDITIONS WITH TEMPERATURES DIPPING BELOW AVERAGE DURING THE
MID TO LATE WEEK PERIOD.
AVIATION
MINOR VISIBILITY RESTRICTIONS DUE TO SMOKE WILL PERSIST THIS
AFTERNOON - AS HIGH CLOUDS WASH ACROSS THE AIRSPACE. AN APPROACHING
COLD FRONT LATE THIS EVENING AND OVERNIGHT WILL BRINGS THE CHANCE
FOR SHOWERS AND THUNDERSTORMS. EXPECTING ANY ACTIVITY THAT
APPROACHES WILL BE DECAYING, GIVEN THE TIME OF DAY AND THE REDUCED
CAPACITY TO SUPPORT VIGOROUS CONVECTION. AS SUCH WILL REMAIN
BEARISH ON CONVECTIVE COVERAGE. WINDS WILL FLIP AROUND THE
WEST/NORTHWEST AROUND DAYBREAK TUESDAY AND QUICKLY GAIN A MEANINGFUL
GUST COMPONENT - WITH GUSTS IN THE 25KT NEIGHBORHOOD THROUGH MUCH OF
TUESDAY.
D21/DTW CONVECTION..THERE IS A CHANCE FOR A FEW THUNDERSTORMS ACROSS
THE AIRSPACE AROUND MIDNIGHT.
DTW THRESHOLD PROBABILITIES
* LOW IN THUNDERSTORMS LATE TONIGHT.
* LOW FOR WESTERLY CROSSWINDS
PREV DISCUSSION
ISSUED AT 353 AM EDT MON JUL 20 2026
DISCUSSION...
HIGH PRESSURE WILL DRIFTS OFF THE MID-ATLANTIC COAST TODAY LEADING
TO INCREASING SOUTHWEST RETURN FLOW. INFLUENCE FROM THIS HIGH
PRESSURE WILL BRING DRY AND AROUND AVERAGE TEMPERATURES THIS
AFTERNOON. HIGHS TODAY SHOULD LAND IN THE LOW 80S FOR MOST THE AREA.
THERE REMAINS HAZE/SMOKE FROM WILDFIRES HANGING AROUND TO THE WEST
AND PARTS OF THE STATE TODAY THAT WILL PIVOT BACK THROUGH THE AREA AS
WINDS BECOME SOUTHWESTERLY. SOME IMPROVEMENTS TO THE AIR QUALITY ARE
EXPECTED COMPARED TO THE LAST SEVERAL DAYS, BUT CONCENTRATIONS STILL
MAY BE IN THE UNHEALTHY FOR SENSITIVE GROUPS AQI RANGE PER EGLE.
THUS, AN AIR QUALITY ALERT REMAINS IN PLACE THROUGH TODAY.
PROSPECTS FOR SHOWERS AND THUNDERSTORMS INCREASE TONIGHT AS A POTENT
CANADIAN SHORTWAVE AND COLD FRONT SWING ACROSS THE REGION. MODELS DO
POINT TO A VORT MAX THAT WILL ROUND THE WESTERN CONUS RIDGE AHEAD OF
THIS WAVE EARLY THIS EVENING, BUT LACK OF INSTABILITY AND MOISTURE
AVAILABILITY SHOULD KEEP THE AREA MOSTLY DRY UNTIL LATER TONIGHT.
HIRES MODELS DEPICT BLOSSOMING CONVECTION OCCURING WEST OF LAKE
MICHIGAN THAT ARRIVES AS A BROKEN LINE INTO SOUTHEAST MICHIGAN.
THERE IS SOME UNCERTAINTY IN REGARDS TO TIMING WITH CONVECTION FIRST
ARRIVING BETWEEN 04-06Z ACROSS THE SAGINAW VALLEY AND SPREADING
SOUTHEASTWARD TO THE DETROIT METRO REGION IN THE 10-12Z WINDOW. THE
GREATER UNCERTAINTY REMAINS THE AVAILABLE INSTABILITY IN THE 06-12Z
WINDOW AS CONVECTION IS EXPECTED TO ARRIVE WITH THE GREATER SYNOPTIC
SUPPORT OUTPACING THE INSTABILITY. THIS WOULD LEAN TOWARDS A
WEAKENING OF ANY MORE ORGANIZED CONVECTION AS IT MOVES INTO SOUTHEAST
MICHIGAN. THOUGH, MOISTURE QUALITY IS EXPECTED TO IMPROVE WITH PWATS
TO NEAR 2.00 INCHES ALONG WITH INCREASING DEEP LAYER SHEAR AND
STEEPENING MID- LEVEL LAPSE RATES. THIS AT LEAST SUPPORTS HIGH POPS
FOR SHOWERS WITH EMBEDDED THUNDERSTORMS THAT WILL POSE AN ISOLATED
SEVERE WEATHER RISK. CONVECTIVE OUTLOOK CONTINUES TO CARRY A MARGINAL
RISK FOR ALL OF SOUTHEAST MICHIGAN WITH A SMALL PORTION OF SLIGHT
RISK ACROSS FAR NORTHWEST PORTIONS OF THE CWA. DAMAGING WIND GUSTS
AND BRIEF HEAVY DOWNPOURS ARE THE MAIN THREATS.
SYSTEM'S COLD FRONT WILL BE TRAILING BEHIND THE LEAD WAVE OF
THUNDERSTORMS IN THE MORNING AND PUSH THROUGH DURING THE DAY.
DESTABILIZATION WILL BE QUESTIONABLE POST MORNING THUNDERSTORMS. IF
FRONTAL TIMING LAGS ENOUGH, ADDITIONAL THUNDERSTORMS WILL BE
POSSIBLE THAT MAY POSE AN ISOLATED SEVERE RISK. FAVORED AREA WOULD
BE FAR SOUTHEAST PORTIONS OF THE CWA (ROUGHLY ALONG AND SOUTH OF A
PORT HURON TO ADRIAN LINE).
PASSAGE OF THE FRONT WILL BRING A NOTICEABLE DROP IN TEMPERATURES
FOR WEDNESDAY WITH 850MB TEMPERATURES FALLING TO BELOW 10C RESULTING
IN DAYTIME HIGH TEMPERATURES IN THE LOW TO MID 70S. SURFACE HIGH
PRESSURE SHOULD KEEP CONDITIONS MOSTLY DRY MID-WEEK EVEN WITH BROAD
CYCLONIC FLOW ALOFT FROM THE EASTERN CANADIAN CLOSED MID-UPPER LOW.
THE ONLY EXCEPTION MAY BE ACROSS THE THUMB WHERE A FEW SHOWERS EARLY
WEDNESDAY MAY BE POSSIBLE AS A SHORTWAVE DROPS ACROSS THE NORTH
CENTRAL GREAT LAKES. MICHIGAN WILL REMAIN UNDER A DRY AND COOLER
NORTHWEST FLOW INTO THE LATE WEEK PERIOD WHILE RESIDING BETWEEN THE
EAST CANADIAN TROUGH AND THE WESTERN CONUS RIDGE. THIS BRINGS
TEMPERATURES ROUGHLY AROUND AVERAGE TO CLOSE OUT THE WORK WEEK WHILE
LIMITING CONVECTIVE CHANCES.
MARINE...
HIGH PRESSURE INFLUENCE WANES ACROSS THE CENTRAL GREAT LAKES TODAY
WITH DRY INITIAL CONDITIONS. UNSETTLED WEATHER BUILDS IN THIS
EVENING AND OVERNIGHT, AS A STRONG LOW PRESSURE SYSTEM TRACKS ACROSS
CENTRAL/SOUTHERN ONTARIO. GUSTY WINDS AHEAD OF THE ATTENDANT FRONT
WILL LEAD TO A PERIOD OF SMALL CRAFT ADVISORY CONDITIONS,
PARTICULARLY ACROSS SAGINAW BAY, WHERE SOUTHWESTERLY FLOW CHANNELS
MORE EFFICIENTLY. A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR THE BAY
WITH ADDITIONAL SMALL CRAFT ADVISORIES EXTENDING ACROSS THE REST OF
THE NEARSHORE ZONES WITH TIME, AS FLOW VEERS WESTERLY, THEN
NORTHWESTERLY. POTENTIAL EXISTS FOR SHOWERS AND THUNDERSTORMS TO
OVERSPREAD THE WATERWAYS AS THE FRONT MOVES THROUGH, SUPPORTING
PERIODS OF LOCALLY HIGHER WINDS AND WAVES. SHOWERY/STORMY CONDITIONS
COULD PERSIST ON TUESDAY BEFORE HIGH PRESSURE FROM ALBERTA/MANITOBA
BUILDS IN BY TUESDAY EVENING, PRODUCING A DRYING EFFECT. TIGHTER
GRADIENT FLOW ARISES TUESDAY AFTERNOON WITH AN ENERGETIC
NORTHWESTERLY LOW-LEVEL JET FAVORING NON-ZERO POTENTIAL FOR A PERIOD
OF GUSTS TO GALES FOR PORTIONS OF THE HURON BASIN THROUGH WEDNESDAY.
DTX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 4 PM EDT WEDNESDAY FOR LHZ421-422.
SMALL CRAFT ADVISORY FROM 4 AM TUESDAY TO 10 PM EDT WEDNESDAY FOR
LHZ441>443.
LAKE ST CLAIR...SMALL CRAFT ADVISORY FROM 4 AM TO 10 PM EDT TUESDAY FOR LCZ460.
MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY FROM 4 AM TO 10 PM EDT TUESDAY FOR LEZ444.
AVIATION.....MANN
DISCUSSION...AA
MARINE.......KGK
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