899
FXUS63 KDTX 100752
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
352 AM EDT SUN AUG 10 2025
KEY MESSAGES
- HOT AND MUGGY WEATHER THROUGH MONDAY WITH HEAT INDEX WELL INTO THE
90S.
- POTENTIAL FOR SHOWERS AND THUNDERSTORMS EARLY NEXT WEEK.
DISCUSSION
SOUTHEAST MICHIGAN WILL REMAIN POSITIONED TO FINISH THE WEEKEND
PERIOD WITHIN THE WESTERN FLANK OF PREDOMINATE LARGE SCALE UPPER
RIDGING. THIS AFFORDS ANOTHER DAY OF HIGHER MAGNITUDE WARMTH, WITHIN
THE BACKDROP OF AN ELEVATED MEAN THICKNESS FIELD, FULL INSOLATION
POTENTIAL AND PREVAILING LOW LEVEL SOUTHERLY FLOW. MODEL PROJECTION
OF LOW LEVEL MOISTURE QUALITY POINTS TO A SIMILAR PROFILE AS NOTED
YESTERDAY, WITH DEWPOINT READINGS LARGELY PARKED IN THE UPPER 60S TO
AROUND 70 DEGREES DURING PEAK HEATING. HIGHS TARGETING THE 89 TO 93
DEGREE RANGE, LENDING TO AN AFTERNOON PEAK IN HEAT INDEX OF MIDDLE
90S. ENVIRONMENT LACKING IN MEANINGFUL FORCED ASCENT TO OVERCOME A
CAPPED, STABLE MID LEVEL PROFILE WILL LARGELY SUPPORT DRY
CONDITIONS. FORECAST MAINTAINS AN ISOLATED OPPORTUNITY FOR
CONVECTIVE DEVELOPMENT OVER THE SAGINAW VALLEY LATE TODAY, WITH SOME
INDICATION OF GREATER CONVERGENCE EMERGING OVER CENTRAL LOWER MI.
UPPER RIDGING WILL MAINTAIN GREATER INFLUENCE INTO MONDAY, AS
IMPINGING WEAK HEIGHT FALLS STRUGGLE TO GAIN TRACTION INITIALLY WITH
AN INITIAL LEAD SHORTWAVE SHEARING MORE TOWARD THE NORTHERN GREAT
LAKES. THIS SOLIDIFIES THE RESIDENT HOT AND HUMID CONDITIONS, WITH
LITTLE NOTEWORTHY CHANGE IN EITHER THE THERMAL OR MOISTURE PROFILE
AGAIN TRANSLATING INTO A PEAK HEAT INDEX OF MID 90S. MAIN IMPETUS
FOR CONVECTIVE DEVELOPMENT REMAINS A SOUTHWEST TO NORTHEAST ORIENTED
HIGHER THETA-E AXIS ALIGNED ALONG THE EDGE OF THE HEIGHT FALL
GRADIENT, ALLOWING INTERLUDES OF DCVA AND MOISTURE CONVERGENCE TO
ANCHOR ASCENT WITHIN A LESS CAPPED ENVIRONMENT. THIS AXIS EASES
FURTHER INTO LOWER MICHIGAN WITH TIME, PROVIDING AT LEAST A LOW
POTENTIAL FOR LATE DAY OR EVENING CONVECTIVE DEVELOPMENT. HIGHER
PROBABILITY WITH NORTHWEST EXTENT, BUT WITH PROSPECTIVE COVERAGE
MUTED OVERALL BY A POORLY FORCED ENVIRONMENT STILL FEATURING A WARM
MID LEVEL PROFILE. MEAGER WIND FIELDS WILL KEEP ANY ACTIVITY
DISORGANIZED, WITH SLOW MOVING SINGULAR CELLS AFFORDING SOME BRIEF
HEAVY RAINFALL.
GRADUAL DECLINE IN UPPER HEIGHTS AHEAD OF AN INBOUND MID LEVEL
TROUGH WILL EASE THE ATTENDANT MAIN THETA-E PLUME INTO THE REGION
TUESDAY. THIS AFFORDS THE MOST FAVORABLE UNDERLYING THERMODYNAMIC
PROFILE FOR CONVECTIVE DEVELOPMENT THIS FORECAST PERIOD. WITH THAT,
FORCING FIELD REMAINS QUITE ILL-DEFINED. GOVERNING MID LEVEL
SOUTHWEST FLOW ALONG THE DOWNSTREAM FLANK OF THE UPPER TROUGH MAY
YIELD ONE OR MORE VORTICITY MAXIMUM THIS PERIOD. WEAK PRE-FRONTAL
LOW LEVEL TROUGHING AND/OR BOUNDARY INTERACTION FROM OUTFLOW/LAKE
BREEZE ACTIVITY ALSO A POSSIBILITY. FORECAST WILL CONTINUE TO
HIGHLIGHT A GENERIC, BROAD MENTION FOR SHOWERS AND THUNDERSTORMS,
TARGETING THE AFTERNOON AND EVENING HOURS. AGAIN CONVECTIVE
ORGANIZATION CONTAINED BY LOW BULK WIND SHEAR VALUES, WITH LOCALLY
HEAVY RAINFALL THE MAIN ISSUE SHOULD A GREATER RESPONSE MATERIALIZE.
CONVECTIVE POTENTIAL MAY LINGER INTO TUESDAY NIGHT/WEDNESDAY AS THE
UPPER TROUGH AXIS AND ASSOCIATED FRONTAL BOUNDARY ARRIVE IN RESPONSE
TO A STRONGER MID LEVEL WAVE EJECTING ACROSS THE NORTHERN GREAT
LAKES. LESS HUMID CONDITIONS THEN EMERGE FOR THE LATE WEEK PERIOD AS
CANADIAN HIGH PRESSURE TAKES CONTROL. INBOUND AIRMASS COOLER
RELATIVE TO THIS RECENT HOT STRETCH BUT STILL EDGED ON THE WARMER
SIDE OF AVERAGE FOR MID AUGUST.
MARINE
VERY WARM SOUTHERLY FLOW CONTINUES WITH STRONG NEAR WATER STABILITY
LEADING TO WINDS GENERALLY UNDER 20 KNOTS. DRY MID LEVELS IN PLACE
OVER THE CENTRAL GREAT LAKES WILL MOSTLY CAP THUNDERSTORM ACTIVITY,
BUT A FEW STORMS ARE LIKELY TO SNEAK INTO THE NORTHERN SECTIONS OF
LAKE HURON AS A COLD FRONT DISSIPATES NEARBY TO THE WEST.
MONDAY INTO TUESDAY, A SECOND LOW DEVELOPS OVER SOUTHERN ONTARIO AND
TRACKS JUST NORTH OF LAKE SUPERIOR, DRAWING A MORE SIGNIFICANT COLD
FRONT THROUGH THE AREA AND CLEARING OUT THE WARM/HUMID AIRMASS BY
MID-WEEK. THIS FRONT WILL LIKELY TRIGGER SHOWERS AND THUNDERSTORMS.
SOUTHWEST WINDS SHIFT TO THE NORTHWEST AS A RESULT OF THIS FRONTAL
PASSAGE AS WELL.
PREV DISCUSSION
ISSUED AT 1153 PM EDT SAT AUG 9 2025
AVIATION...
LIGHT SOUTHERLY FLOW OF WARM AND HUMID AIR CONTINUES INTO LOWER MI
BETWEEN ATLANTIC COAST SURFACE HIGH PRESSURE AND A BROAD FRONTAL
SYSTEM EXTENDING FROM THE MIDWEST TO SOUTHERN PLAINS. THE KEY IS A
500 MB RIDGE OVERHEAD GUARDING AGAINST EASTWARD PROGRESS OF ONGOING
THUNDERSTORMS THAT EXTEND FROM SOUTHERN WI INTO CENTRAL LAKE
MICHIGAN. EVEN HIGH CLOUD DEBRIS LARGELY FAILS TO MAKE IT INTO THE
TERMINAL CORRIDOR LEAVING VFR CLEAR SKY IN PLACE THROUGH THE
MORNING. MODEST CUMULUS THEN REDEVELOPS OVERHEAD IN THE AFTERNOON
WHILE STORMS HOLD OFF NEARBY TO THE WEST INTO SUNDAY EVENING.
FOR DTW/D21 CONVECTION... THUNDERSTORMS ARE NOT EXPECTED TONIGHT
THROUGH SUNDAY.
THRESHOLD PROBABILITIES...
* NONE.
DTX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
DISCUSSION...MR
MARINE.......SF
AVIATION.....BT
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