078
FXUS63 KDTX 131911
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
311 PM EDT FRI JUN 13 2025
KEY MESSAGES
- INCREASING CHANCES FOR RAIN SHOWERS THIS EVENING AND OVERNIGHT,
SOUTH OF M-59; A RUMBLE OF THUNDER CANNOT BE RULED OUT.
- SHOWERS MAY LINGER BETWEEN I-94 AND THE MI/OH BORDER SATURDAY
MORNING WITH DECREASING CLOUD COVER FROM NORTH TO SOUTH AS THE DAY
PROGRESSES.
- WARMING TREND BEGINS SUNDAY WITH HIGHS IN THE 80S, FOLLOWED BY
INCREASING HUMIDITY NEXT WEEK.
DISCUSSION
CUT-OFF LOW OVER MISSOURI ATTEMPTS TO TRANSITION TO AN OPEN WAVE,
GRADUALLY DRIFTING NORTHEASTWARD INTO THE OHIO VALLEY THROUGH THE
NEXT 48 HOURS. THIS WILL ACTIVATE THE STALLED FRONTAL BOUNDARY
DRAPED ACROSS NORTHERN IN/OH RESULTING IN SOME SHOWER ACTIVITY
LIFTING INTO PORTIONS OF SOUTHEAST MICHIGAN. AT PRESENT, A WEAK LOBE
OF CVA HAS TRIGGERED A BROKEN MESOSCALE LINE OF LIGHT SHOWERS WHICH
HAVE HELD TOGETHER OVER THE LAST SEVERAL HOURS, AND CONTINUE TO INCH
NORTHWARD. ADDED A 15 PERCENT POP AREA THROUGH HE DIURNAL WINDOW
BEFORE THESE SHOWERS SHOULD DISSIPATE. 13.12Z MODELS HAVE TRENDED
BOTH EARLIER AND FURTHER NORTH WITH MORE POTENT ACTIVITY THIS
EVENING AND OVERNIGHT, MAINLY FOR LOCATIONS SOUTH OF M-59. KDTX
RETURNS HAVE INCREASED OVER LENAWEE AND MONROE COUNTIES WITH BOTH
ADG AND TTF NOW REPORTING -RA. ALSO MONITORING LOW-END THUNDER
POTENTIAL TONIGHT, BUT LEANING TOWARDS A VERY ISOLATED APPROACH
GIVEN THE LACK OF DYNAMIC FORCING AND NIL INSTABILITY NORTH OF THE
BOUNDARY. A SLIGHT CHANCE THUNDER MENTION WAS INCLUDED WITH THE
OUTGOING FORECAST.
THE SURFACE LOW IS PROGGED TO TRACK EAST ALONG THE OHIO RIVER
TONIGHT WHILE HIGH PRESSURE CONTINUES TO BUILD SOUTHEASTWARD,
CENTERING OVER WESTERN QUEBEC. THE BOUNDARY SHOWS MINIMAL MOVEMENT
WHILE TRIGGERING SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS WHICH
LIKELY PERSIST SATURDAY MORNING AND INTO THE MIDDAY HOURS. THE MORE
PROLONGED ACTIVITY SHOULD BE CONFINED WELL SOUTH OF I-94, MORESO
NEAR THE MI/OH BORDER. MAINLY DRY CONDITIONS RETURN SATURDAY FOR THE
REST OF THE AREA WITH INCREASING GEOPOTENTIAL HEIGHTS. CLOUDS CLEAR
FROM NORTH TO SOUTH WHICH LEADS TO A THERMAL GRADIENT ORIENTED WITH
THE CLEARING TREND. HOWEVER, SHOWERS AND THUNDERSTORMS LIKELY
PERSIST SOUTH OF I-94 SATURDAY MORNING AND INTO THE MIDDAY HOURS
NEAR THE MI/OH BORDER.
DAILY TEMPERATURE RISES ENSUE SUNDAY WITH 850 MB TEMPERATURES
ASCENDING INTO THE MID-UPPER TEENS (CELSIUS) AND A PROLONGED STRETCH
OF +80F, POSSIBLY THROUGH THE ENTIRE WEEK. SPLIT-FLOW ALOFT EMERGES
SATURDAY, LASTING INTO EARLY NEXT WEEK WHICH SUPPRESSES WIDESPREAD
SHOWER/STORM OPPORTUNITIES. EXTENDED STRETCH OF EASTERLY FLOW SHIFTS
SOUTHERLY MONDAY INTO TUESDAY AS DEEP-LAYER FLOW ORIENTS
SOUTHWESTERLY WITH TIME. THIS DELIVERS THE FIRST REAL DOSE OF MUGGY
WEATHER AS SURFACE DEWPOINTS CLIMB INTO THE UPPER 60S, POSSIBLY
BREAKING THE 70F MARK BY MIDWEEK. THIS COINCIDES WITH THE NEXT
SHORTWAVE TROUGH FEATURE TRACKING ACROSS THE MIDWEST. IF
SHEAR/INSTABILITY MATERIALIZES APPROPRIATELY, THUNDERSTORM ACTIVITY
COULD BECOME WIDESPREAD.
MARINE
A FRONTAL BOUNDARY REMAINS STALLED OVER THE OHIO VALLEY WHILE BROAD
HIGH PRESSURE OVER NORTHERN ONTARIO GRADUALLY SHIFTS INTO QUEBEC
THIS WEEKEND. THIS PATTERN SUSTAINS LIGHT NORTHEAST WIND, GENERALLY
15 KT OR LESS, ACROSS THE CENTRAL GREAT LAKES. ENHANCED WIND
FUNNELING DOWN THE AXIS OF SAGINAW BAY WILL REACH 20 TO 25 KNOTS AND
A SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH TONIGHT. SHOWERS
CONTINUE SPREADING ACROSS THE SOUTHERN LAKES INTO EARLY SATURDAY AS
A WEAK LOW TRACKS ALONG THE STALLED FRONT TO THE SOUTH. DRIER
WEATHER FOLLOWS SUNDAY AS THE HIGH PRESSURE BUILDS IN FROM THE
NORTH. GENERALLY WEAK FLOW PERSISTS INTO EARLY NEXT WEEK WITH WARMER
AND MORE UNSTABLE CONDITIONS ARRIVING ON SOUTH WIND MONDAY AND
TUESDAY.
PREV DISCUSSION
ISSUED AT 139 PM EDT FRI JUN 13 2025
AVIATION...
SE MI REMAINS IN A STAGNATE PATTERN LOCKED IN BETWEEN A STALLED
SURFACE BOUNDARY SOUTH OF THE MI BORDER AND THE ELEVATED PORTION OF
THE FRONT PRODUCING SHOWERS UP ACROSS NORTHERN LOWER AND THE U.P. A
LOW PRESSURE SYSTEM RIPPLING ALONG THE SURFACE FRONT IS BRINGING AN
AREA OF LIGHT RAIN UP TOWARD THE DETROIT TAF SITES SO INCLUDED A FEW
HOURS OF SHOWER CHANCES THERE THIS AFTERNOON. ADDITIONAL ROUND OF
LIGHT SHOWERS WILL BE POSSIBLE TONIGHT FOR THE SAME LOCATIONS AS THE
CENTER OF THE LOW PASSES JUST TO THE SOUTH. CHANCE TO SEE MVFR CIGS
WITH THE OVERNIGHT ACTIVITY. A VERY NARROW BAND OF SHOWERS WILL LIFT
THROUGH FNT BEFORE 18Z BUT BEYOND THAT THERE IS NO RAIN EXPECTED.
WINDS WILL BE OUT OF THE NE/E THROUGH THE PERIOD WITH ONLY A SMALL
DIURNAL/NOCTURNAL INCREASE/DECREASE IN SPEED TO CONTEND WITH.
FOR DTW/D21 CONVECTION...THERE WILL BE A CHANCE FOR SHOWERS THIS
AFTERNOON AND AGAIN TONIGHT AS A LOW PRESSURE SYSTEM PASSES SOUTH OF
THE STATE. THUNDERSTORMS ARE NOT EXPECTED DUE TO LACK OF
INSTABILITY.
THRESHOLD PROBABILITIES...
* LOW FOR THUNDERSTORMS THIS AFTERNOON AND TONIGHT.
* LOW TO MEDIUM FOR CEILINGS AT OR BELOW 5,000 FEET THIS AFTERNOON
AND TONIGHT.
DTX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 4 AM EDT SATURDAY FOR LHZ421-422.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
DISCUSSION...KGK
MARINE.......TF
AVIATION.....DRK
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