464
FXUS63 KDTX 040312
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1112 PM EDT SAT OCT 3 2026
KEY MESSAGES
- COOL TONIGHT WITH LOWS IN THE LOWER 40S TO UPPER 30S. NARROW BAND
OF LIGHT SHOWERS POSSIBLE LATE TONIGHT INTO SUNDAY MORNING MAINLY
NORTH OF I-69.
- SEASONABLE HIGHS SUNDAY NEAR 70 DEGREES.
- BELOW NORMAL TEMPERATURES ARRIVE MONDAY WITH HIGHS ONLY NEAR 60
AND LOWS FALLING INTO THE 30S. CHANCE FOR FROST IS POSSIBLE MONDAY
NIGHT PARTICULARLY OVER THE SAGINAW VALLEY/THUMB.
AVIATION
VFR CONDITIONS WILL PREVAIL THROUGH THE EARLY MORNING HOURS WITH
MOSTLY CLEAR SKIES TO THE SOUTH AND LIGHT SOUTH WINDS TO START THE
TAF PERIOD AS SURFACE HIGH PRESSURE MOVES INTO THE NEW ENGLAND
REGION. A LOW PRESSURE SYSTEM WILL QUICKLY FOLLOW MOVING ACROSS THE
UPPER MIDWEST AT THIS TIME WITH NOTABLE INCREASE IN MID TO HIGH
CLOUD AND RAINFALL MOVING ACROSS NORTHERN LOWER MICHIGAN. SOME OF
THIS RAINFALL ALONG THE TAIL END MAY REACH MBS AND FNT BETWEEN 09Z
TO 11Z SUNDAY MORNING. EXPECTING ONLY LIGHT RAIN IF IT DOES OCCUR
AND CEILINGS SHOULD REMAIN VFR. MOSTLY DRY COLD FRONTAL PASSAGE
THROUGH SOUTHEAST MICHIGAN SUNDAY RESULTING IN A WEST WIND SHIFT AND
SUPPORT LOWER CEILINGS TO AROUND 5KFT DURING THE DAY.
D21/DTW CONVECTION... THUNDERSTORMS ARE NOT FORECAST THIS PERIOD.
DTW THRESHOLD PROBABILITIES
* LOW FOR CEILING 5000 FT OR LESS SUNDAY AFTERNOON.
PREV DISCUSSION
ISSUED AT 256 PM EDT SAT OCT 3 2026
DISCUSSION...
HIGH PRESSURE CENTERED OVER NORTHERN LOWER MI HAS MAINTAINED A
PLEASANT FALL DAY ACROSS SE MI. EAST-NORTHEAST WINDS HAVE WRAPPED
ENOUGH LAKE MOISTURE AROUND THE PERIPHERY OF CORE SUBSIDENCE TO
SUPPORT A HEALTHY COVERAGE OF DIURNAL CUMULUS OVER THE
SOUTHERN/EASTERN PORTIONS OF THE AREA WITH SUNNY SKIES HOLDING OVER
THE WESTERN/NORTHERN PORTIONS. CLOUDS FADE EARLY THIS EVENING WITH
SUNSET LEADING TO ANOTHER COOL NIGHT WITH LOWS FALLING INTO THE
LOWER 40S.
A SHORTWAVE TROUGH CURRENTLY WORKING ACROSS THE UPPER MIDWEST TRACKS
INTO THE NORTH-CENTRAL GREAT LAKES LATE TONIGHT AS HIGH PRESSURE IS
SHUNTED EAST. MOISTURE TRANSPORT ISN'T PARTICULARLY STRONG DUE TO
WEAK LOWER LEVEL WINDS (SUB 40KTS BELOW 700MB), HOWEVER IS ENOUGH TO
DRAW IN RIBBON OF MODEST THETA-E FROM THE MIDWEST ALONG THE LEAD
EDGE OF THE MID-LEVEL WAVE/PV ANOMALY. ISENTROPIC ASCENT IS ALSO
CONFINED ALONG THIS LEAD EDGE RESULTING IN A NARROW BAND OF
POTENTIAL SHOWERS SLIDING ACROSS BETWEEN ~09-13Z. OWING TO CLOSER
PROXIMITY TO THE SHORTWAVE AND COLD POOL, SAID SHOWER CHANCES
ESSENTIALLY CONFINED NORTH OF I-69. SURFACE COLD FRONT LAGS, NOT
CROSSING UNTIL SUNDAY EVENING, WITH MINIMAL FANFARE OUTSIDE A LOW
CHANCE FOR AN ISOLATED SHOWER/DRIZZLE.
SOME OF THE COOLEST AIR OF THE SEASON THUS FAR FOLLOWS AS 850MB
TEMPS FALL TO 1-2C BY SUNDAY NIGHT DROPPING LOWS TO THE LOW 40S-
UPPER 30S. THERMAL TROUGHING HOLDS OVER THE CENTRAL GREAT LAKES
THROUGH MONDAY AS 850MB TEMPS NUDGE DOWN FURTHER TO AROUND 0C
LIMITING DIURNAL RECOVERY TO HIGHS NEAR 60. BUILDING SURFACE HIGH
PRESSURE LATE DAY MONDAY PROMOTES CLEARING SKIES AND NEAR CALM WINDS
BY MONDAY NIGHT SUPPORTING SE MI'S FIRST SHOT AT FROST, PARTICULARLY
ACROSS THE SAGINAW VALLEY/THUMB, AS LOWS APPROACH THE MID 30S. MORE
SEASONABLY AVERAGE TEMPERATURES RETURN FOR THE MIDWEEK PERIOD AS
HUDSON BAY UPPER TROUGHING SHIFTS TOWARDS LABRADOR.
MARINE...
HIGH PRESSURE OVER THE CENTRAL AND EASTERN GREAT LAKES REGION WILL
GRADUALLY MOVE OVER THE NORTHEAST THROUGH THE END OF THE WEEKEND AS
LOW PRESSURE TRACKS EAST ACROSS SOUTHERN ONTARIO, REMAINING NORTH OF
LAKE SUPERIOR. WHILE THIS LOW IS PROGGED TO REMAIN WELL NORTH OF THE
AREA, IT IS EXPECTED TO INTENSIFY AS IT MOVES EAST TOWARDS THE JAMES
BAY AREA, RESULTING IN A LARGE-SCALE UPTICK IN WINDS OVER THE
REGION. A COLD FRONT EXTENDING SOUTH FROM THE LOW PRESSURE SYSTEM
WILL ALSO USHER IN A WIND SHIFT ON SUNDAY. TONIGHT INTO SUNDAY
MORNING, SOUTH WINDS PREVAIL ACROSS LAKE HURON. WINDS THEN BECOME
WESTERLY MID-DAY SUNDAY AND GRADUALLY WILL SHIFT AND COME OUT OF THE
NORTHWEST SUNDAY AFTERNOON AND EVENING. GENERALLY SPEAKING SUNDAY
THROUGH MONDAY, WINDS OF 25 TO 30 KNOTS ARE EXPECTED OVER LAKE
HURON, WITH THE STRONGEST WINDS EXPECTED ACROSS THE NORTHERN THIRD.
SUNDAY EVENING THROUGH MONDAY MORNING WILL SEE THE BEST WINDOW OF
POTENTIAL FOR WINDS AROUND OR IN EXCESS OF 30 KNOTS OVER THE OPEN
WATERS OF LAKE HURON. THIS IS ESPECIALLY SO UP ACROSS THE FAR
NORTHERN THIRD OF THE LAKE. WILL CONTINUE TO MONITOR TRENDS IN THE
FORECAST AND PROBABILISTIC DATA ON LOW-END GALE POTENTIAL FOR SUNDAY
NIGHT INTO MONDAY MORNING. RIGHT NOW PROBABILITY FIELDS ARE AROUND
20% FOR SEEING LOW-END GALES AROUND 34 KNOTS ACROSS FAR NORTHERN
LAKE HURON.
FURTHER SOUTH ON LAKE ST. CLAIR AND THE NEARSHORE WATERS OF LAKE
ERIE, SIMILAR WIND DIRECTIONS AND WIND SHIFTS WILL BE OBSERVED, BUT
THEY WILL BE DELAYED IN TIME COMPARED TO OVER LAKE HURON. WINDS WILL
ALSO INCREASE SUNDAY NIGHT INTO MONDAY; HOWEVER, THEY WILL NOT BE AS
STRONG THAT FAR SOUTH.
WINDS GRADUALLY WEAKEN LATE MONDAY INTO TUESDAY AS A TRANSIENT AREA
OF HIGH PRESSURE BRIEFLY MOVES THROUGH THE REGION. WE THEN SEE
ANOTHER SYSTEM TRACK NORTH OF THE AREA, BUT WILL BRING ANOTHER
UPTICK IN WINDS FOR MID-WEEK.
DTX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
LAKE HURON...GALE WATCH FROM SUNDAY EVENING THROUGH MONDAY MORNING FOR LHZ361-
362.
SMALL CRAFT ADVISORY FROM 11 AM SUNDAY TO 8 AM EDT MONDAY FOR
LHZ421.
SMALL CRAFT ADVISORY FROM 11 AM SUNDAY TO 2 PM EDT MONDAY FOR
LHZ441.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
AVIATION.....AA
DISCUSSION...KDK
MARINE.......JA
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