000
FXUS63 KDTX 200337
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1137 PM EDT SAT JUL 19 2025
KEY MESSAGES
- DRY CONDITIONS SUNDAY THROUGH TUESDAY.
- HEAT AND A LOW CHANCE OF THUNDERSTORMS RETURN MID WEEK, WITH HEAT
INDICES APPROACHING 100 DEGREES POSSIBLE ON THURSDAY.
AVIATION
A RATHER COMPLEX CLOUD/FOG SET UP IS EXPECTED OVERNIGHT THROUGH THE
EARLY MORNING HOURS. LIGHT WINDS AMPLE LOW LEVEL MOISTURE, MARKED BY
SFC DEWPOINTS AROUND 70 WILL BE SUPPORTIVE OF THIS LOW CLOUD/FOG
DEVELOPMENT AS THE HIGHER CLOUDS DEPART TO THE EAST. MEANWHILE, A
SLOW MOVING COLD FRONT WILL ADVANCE ACROSS SE MI OVERNIGHT. SHALLOW
POST FRONTAL COLD AIR ADVECTION INTO THE AMBIENT LOW LEVEL MOISTURE
WILL SUPPORT AN EXPANSION OF LOW CLOUDS LASTING THROUGH THE MORNING.
PROBABILISTIC GUIDANCE AND VARIOUS MODEL SOUNDINGS SUGGEST A MIX OF
LOW END MVFR AND IFR BASED CLOUDS THROUGH THE MORNING. DIURNAL
MIXING AND DRY AIR ADVECTION FROM THE NORTH WILL RESULT IN A SUBTLE
EROSION OF EARLY DAY LOW CLOUDS DURING THE LATE AFTERNOON SUNDAY.
FOR DTW/D21 CONVECTION...ALTHOUGH ISOLATED SHOWERS REMAIN POSSIBLE
ALONG THE COLD FRONT EARLY SUNDAY MORNING, THUNDERSTORM
PROBABILITIES ARE LOW.
THRESHOLD PROBABILITIES...
* HIGH IN CEILINGS AOB 5000 FEET OVERNIGHT AND SUNDAY.
PREV DISCUSSION
ISSUED AT 302 PM EDT SAT JUL 19 2025
DISCUSSION...
NO MAJOR CHANGES FOR THIS AFTERNOON AND EVENING FROM THE LATE
MORNING UPDATE, POSTED BELOW FOR COMPLETION WITH MINOR UPDATES, IN
ADDITION TO THE EXTENDED FORECAST:
REMNANTS OF AN MCV FEATURE WILL SWEEP ACROSS SOUTHERN MICHIGAN
THROUGH THE REMAINING AFTERNOON HOURS WITH ADDITIONAL ISOLATED
DEVELOPMENT JUST AHEAD AND NORTH OF THIS FEATURE, ALONG A WARM FRONT
AND WITHIN A LARGE RIBBON OF ENHANCED THETA-E. THE ENVIRONMENT FOR
LATE THIS AFTERNOON AND EVENING REMAINS CHARACTERIZED BY NEBULOUS
FORCING UNDER MODEST INSTABILITY AND DECENT KINEMATICS. ADDITIONAL
SOURCES FOR SHOWER AND THUNDERSTORM LATE TONIGHT WILL BE AHEAD OF AND
ALONG A COLD FRONT THAT WILL SWEEP FROM NORTHWEST TO SOUTHEAST
ACROSS SE MI BETWEEN 23Z-06Z TONIGHT, UNDER THE FAVORABLE RIGHT
ENTRANCE REGION OF THE UPPER-LEVEL JET. THIS WILL BRING HIGHER END
POP CHANCES (50-70%) TO SE MI TONIGHT.
KINEMATICALLY, THE SHEAR PROFILES ARE DECENT, NOTING THE STRONGER
WIND PROFILES IN THE MID-LEVELS WHICH ELEVATE SLIGHTLY LATE THIS
AFTERNOON AND EVENING. 1-6KM BULK SHEAR WILL RANGE BETWEEN 25 TO 35
KNOTS, THE HIGHEST FOUND OVER THE NORTHERN-THIRD OF THE CWA. THIS
WILL BE A POSITIVE FOR ORGANIZED CONVECTION AS INSTABILITY SLOWLY
BUILDS IN THROUGH THE AFTERNOON. THE MAJOR CAVEAT CONTINUES TO BE
THE DEGREE OF INSTABILITY THAT CAN PULL IN AHEAD OF ANY STORM
DEVELOPMENT. MOSTLY CLOUDY SKIES HAVE HELD ACROSS SE MI THROUGH THE
AFTERNOON, ENFORCED WITH CIRROSTRATUS FROM UPSTREAM ACTIVITY WHICH
HAS LIMITED THE DEGREE OF AFTERNOON HEATING. DEW POINTS REMAIN IN
THE MID TO UPPER 60S WITH LOCAL MAXIMUMS IN THE LOW 70S HOLDING
ACROSS THE WEST SIDE OF THE STATE. HI-RES OUTPUT HOLDS SBCAPE VALUES
BETWEEN 500-1000 J/KG ACROSS SE MI, WITH SPC MESOANALYSIS
FORECASTING A LITTLE MORE AGGRESSIVE VALUES JUST ABOVE 1000 J/KG. THE
BETTER THERMODYNAMICS WILL LIKELY RESIDE THROUGH WEST AND CENTRAL
MICHIGAN, INTO THE TRI-CITIES, ALIGNING WITH ARC OF BETTER MOISTURE.
OVERALL, THIS SETUP STILL WARRANTS THE CONTINUED MENTION FOR
ISOLATED SEVERE WEATHER DEVELOPMENT, BUT SEVERE TRENDS HAVE TRENDED
DOWNWARD. SHOWER AND STORMS WILL BE FAVORED BETWEEN THE 4PM-10PM
TIME FRAME. STORM MODE WILL LIKELY RANGE BETWEEN ISOLATED TO
MULTICELL CLUSTER WITH ISOLATED DAMAGING GUSTS FROM WET MICROBURSTS
THE PRIMARY HAZARD. LARGE HAIL AND AN ISOLATED TORNADO ARE SECONDARY
HAZARDS, BUT CANNOT BE RULED OUT UNDER ANY ORGANIZED UPDRAFTS. ANY
SORT OF ROTATING UPDRAFTS WOULD BE FAVORED MORE OVER CENTRAL
MICHIGAN INTO THE TRI-CITIES, ALIGNING WITH THE STRONGEST CAPE
DENSITY AND NOTING BETTER CURVATURE IN THE MID-LEVELS OF SR-
HODOGRAPHS WITH A VERY SLIGHT ELONGATION TO THE 0-1KM SEGMENT.
PASSAGE OF A WEAK LOW PRESSURE SYSTEM TRANSVERSING ACROSS NORTHERN
LOWER MICHIGAN INTO ONTARIO WILL DRAW A COLD FRONT ACROSS THE STATE
LATE TONIGHT THROUGH TOMORROW MORNING, BOOSTED FROM HIGH PRESSURE
FILLING WITHIN ITS WAKE. THE FRONT WILL SLOW ACROSS THE NORTHERN
OHIO VALLEY TOMORROW AFTERNOON WHICH BRINGS LOW END CHANCES FOR
SHOWERS TO BRUSH SOUTHERN MICHIGAN TOMORROW MORNING AND AFTERNOON,
BUT OTHERWISE HIGH PRESSURE BRINGS STABLE CONDITIONS AND DRY WEATHER
TO THE REGION THROUGH TUESDAY. HIGH PRESSURE WILL DEPART INTO THE
WEST ATLANTIC BY THE MIDWEEK PERIOD WHICH WILL STREAM IN HOTTER
TEMPERATURES FROM THE PLAINS INTO THE GREAT LAKES WHERE A 594 DAM
RIDGE WILL BECOME ESTABLISHED. 850MB TEMPERATURES AOA 20C BRING
INCREASINGLY LIKELY CHANCES TO SEE TEMPERATURE HIGHS RETURN INTO THE
90S WED-THU, AND POSSIBLY THROUGH FRIDAY PENDING TIMING OF A
POTENTIAL COLD FRONT AND STORM CHANCES. MEDIUM RANGE MODELS HAVE
TRENDED DRIER THROUGH THE MIDWEEK PERIOD WITH THE STRONGER RIDGE IN
PLACE, BUT LOW-END POP CHANCES HOLD, GIVEN THE CHANCE TO SEE
SHORTWAVE FEATURES ROUND THE RIDGE. PASSAGE OF THIS COLD FRONT LATE
THURSDAY INTO FRIDAY BRINGS THE BETTER CHANCES FOR SHOWER AND
THUNDERSTORMS.
MARINE...
QUIETER CONDITIONS THIS AFTERNOON WILL GIVE WAY TO UNSETTLED
CONDITIONS LATER TODAY AS A LOW PRESSURE SYSTEM TRACKS EAST AND
CROSSES LAKE HURON LATER THIS EVENING. THIS SYSTEM ADVECTS A HUMID,
UNSTABLE AIR MASS WITH SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS DEVELOPING THIS AFTERNOON AND INTO THE OVERNIGHT
HOURS. AMBIENT WIND SPEEDS AND WAVE HEIGHTS WILL HOLD BELOW SMALL
CRAFT ADVISORY CRITERIA BUT ISOLATED TO SCATTERED SEVERE STORMS WILL
BE CAPABLE OF PRODUCING GUSTS IN EXCESS OF 40 KT, HAIL, AND
WATERSPOUTS. THE COLD FRONT CLEARS THE AREA SUNDAY MORNING WITH
DRIER CONDITIONS AND MODERATE NORTH WIND TO WRAP UP THE WEEKEND.
HIGH PRESSURE PASSING TO THE NORTH CAUSES LIGHT WIND TO VEER TO
EASTERLY ON MONDAY. THE NEXT CHANCE OF THUNDERSTORMS LOOKS TO HOLD
OFF UNTIL TUESDAY NIGHT INTO WEDNESDAY ALONG A WARM FRONT MOVING IN
FROM THE MIDWEST.
HYDROLOGY...
NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS
SOUTHEAST MICHIGAN LATE TODAY AND THIS EVENING. BASIN AVERAGED
RAINFALL TOTALS WILL RANGE BETWEEN A QUARTER-INCH TO A HALF- INCH,
HOWEVER, ANY STRONG THUNDERSTORM WILL BE CAPABLE OF QUICKLY
PRODUCING LOCALIZED RAINFALL TOTALS BETWEEN 1 TO 2 INCHES. GIVEN
FASTER STORM MOTIONS, OVERALL FLOODING CONCERNS REMAIN LOW, HOWEVER,
HIGHLY LOCALIZED FLOODING REMAINS POSSIBLE ACROSS URBAN AREAS AND
LOW-LYING FLOOD PRONE LOCATIONS.
DTX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
AVIATION.....SC
DISCUSSION...AM
MARINE.......TF/SS
HYDROLOGY....AM
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