671
FXUS63 KDTX 192043
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
343 PM EST FRI DEC 19 2025
KEY MESSAGES
- SNOW SHOWERS END AND WIND DIMINISHES THIS EVENING.
- GUSTY WIND RETURNS WITH A CHANCE FOR LIGHT SNOW OR RAIN/SNOW MIX
SATURDAY AFTERNOON AND EVENING. NO SNOW ACCUMULATION.
- BELOW NORMAL TEMPERATURES LINGER SUNDAY BUT WITH DRY WEATHER TO
WRAP UP THE WEEKEND.
DISCUSSION
A RESPECTABLE MULTI-BAND MODE OF LAKE EFFECT SNOW PEAKED DURING LATE
MORNING AND EARLY AFTERNOON AS THE LOW LEVEL THERMAL TROUGH CROSSED
LAKE MICHIGAN AND THE LOWER PENINSULA. THE STRONG LOW LEVEL WIND
FIELD AND STEEP BOUNDARY LAYER LAPSE RATE MADE IT EASY FOR BANDS OFF
LAKE MICHIGAN TO MAKE IT ALL THE WAY ACROSS INTO SE MI WITH GOOD
ORGANIZATION, AND DESPITE LOWER END CONVECTIVE DEPTH AVERAGING
AROUND 5 KFT. A FEW OVERACHIEVING BANDS BENEFITED FROM MODEST MID
DECEMBER DAYTIME BOUNDARY LAYER INSTABILITY WITHIN ZONES OF ENHANCED
LOW LEVEL CONVERGENCE AND A THERMAL PROFILE WELL ROOTED IN THE DGZ.
NOW PAST PEAK, A FEW MORE HOURS OF SNOW SHOWERS ARE EXPECTED UNTIL
SYNOPTIC SCALE SUBSIDENCE AND ASSOCIATED DRY AIR QUICKLY SUPPRESS
ACTIVITY BY THIS EVENING.
THE STRENGTH OF THE LARGER SCALE SURFACE WIND FIELD IS ALSO AT PEAK
AS OF FORECAST ISSUANCE. THERE IS STILL A CHANCE FOR A FEW
BORDERLINE ADVISORY LEVEL GUSTS PRIOR TO SUNSET, HOWEVER THE TREND
IS RAPIDLY DECREASING AS THE PARENT LOW PRESSURE SYSTEM MOVES
FARTHER INTO NORTHERN QUEBEC. IN CONTINUED QUICK PROGRESSION OF
PRESSURE SYSTEMS, A NARROW RIDGE OF HIGH PRESSURE SLIDES QUICKLY
THROUGH LOWER MI TONIGHT WHILE THE NEXT SURFACE LOW AND FRONTAL
SYSTEM ORGANIZES OVER THE PLAINS. GUSTY WIND REDEVELOPS AND IS
TEMPERED BY A RAPID INCREASE IN WARM ADVECTION AND ISENTROPIC LIFT
BY SATURDAY MORNING. THE MOISTURE SUPPLY IS ADEQUATE FOR A CHANCE OF
LIGHT SNOW, ALTHOUGH COVERAGE AND DURATION INCREASE FARTHER NORTH
INTO CENTRAL AND NORTHERN LOWER MI WHERE FORCING IS MAXIMIZED CLOSER
TO THE CONSOLIDATING SURFACE LOW. A LIGHT RAIN/SNOW MIX IS IN PLAY
AS SURFACE TEMPERATURES RETURN WELL ABOVE FREEZING THROUGH A SHALLOW
BOUNDARY LAYER UNTIL THE LEADING COLD FRONT/TROUGH SWEEPS THE
MOISTURE AXIS EASTWARD IN THE LATE AFTERNOON. EVEN THEN, READINGS
HOLD ABOVE FREEZING UNTIL AFTER SUNSET WHEN THE PRIMARY/ARCTIC COLD
FRONT ARRIVES WITHIN THE DRY SLOT OF THE LARGER SCALE TROUGH. COLD
ADVECTION THEN DOMINATES FOR THE REST OF SATURDAY NIGHT WHICH TAKES
READINGS DOWN INTO THE TEENS BY SUNDAY MORNING.
HIGH PRESSURE SETTLES IN ACROSS THE GREAT LAKES SUNDAY AND SUNDAY
NIGHT KEEPING TEMPERATURES BELOW NORMAL IN A BROAD ARCTIC AIR MASS.
DRY WEATHER IS PROJECTED DURING THIS TIME WITH BROAD CONSENSUS
ACROSS DETERMINISTIC MODEL SOLUTIONS LEADING UP TO THE NEXT CHANCE
OF PRECIPITATION BY MONDAY. A SHORT WAVE DRIVEN LOW PRESSURE SYSTEM
MOVES INTO THE LEE OF THE ROCKIES DURING THE DAY BUT IS SHOWN TO
HAVE A REACH OF MID LEVEL WARM ADVECTION FAR TO THE EAST INTO THE
GREAT LAKES, REASONABLE CONSIDERING THE BROAD LONG WAVE RIDGE IN
PLACE SOUTH OF THE LOW TRACK. THIS COULD RESULT IN A FEW HOURS OF
WINTRY MIXED PRECIP LATER MONDAY AND MONDAY NIGHT AS THE LOW
PRESSURE SYSTEM APPROACHES ALONG THE CANADIAN BORDER. THIS LEADS
INTO THE WARMING TREND THAT IS FIRMLY ON TRACK FOR THE MID WEEK
CHRISTMAS HOLIDAY.
MARINE
DEPARTING LOW PRESSURE AFFORDS ANOTHER FEW HOURS OF NORTHWEST GALES
BEFORE HIGH PRESSURE BUILDS IN OVERNIGHT TO ALLOW THE EXPIRATION OF
HEADLINES THIS EVENING. HIGH PRESSURE THEN BRUSHES THE SOUTHERN
GREAT LAKES EARLY SATURDAY MORNING, SHIFTING WINDS TO THE SOUTH
SOUTH AND CUTTING OFF ANY LINGERING LAKE EFFECT RESPONSE. THE NEXT
CLIPPER QUICKLY APPROACHES SATURDAY, LEADING TO ANOTHER ROUND OF
GALE POTENTIAL IN BOTH THE WARM AND COLD ADVECTIVE REGIMES. THE WARM
SECTOR EXPANDS INTO LAKE ERIE AND SOUTHERN LAKE HURON DURING THE DAY
SATURDAY, WITH THE LOW LEVEL JET INTENSIFYING TO 50-60 KNOTS BY
AFTERNOON. LOW INVERSION HEIGHTS LIMIT THE DEPTH OF MOMENTUM
TRANSFER, ESPECIALLY FOR THE COLDER NEARSHORE WATERS, TO KEEP
MAJORITY OF GUSTS AOB 30 KNOTS. THAT SAID, A LOCALIZED POCKET OF
OVERLAPPING JET STRENGTH AND WARMER OPEN WATER TEMPERATURES EXISTS
OVER SOUTHERN LAKE HURON WHERE SOUTHERLY FLOW COULD GUST TO GALES AS
EARLY AS MID-MORNING. GALE POTENTIAL THEN INCREASES MORE BROADLY
SATURDAY NIGHT FOR ALL OF LAKE HURON AS A COLD FRONT TRACKS THROUGH
AND SHIFTS WINDS TO THE WEST. PEAK WINDS COINCIDE WITH A STRONG
SURGE OF COLD ADVECTION OVERNIGHT, IN WHICH A PERIOD OF STRONG GALES
IS POSSIBLE. HIGH PRESSURE THEN RETURNS SUNDAY TO EASE WINDS AND
WAVES BACK BELOW HEADLINE THRESHOLDS.
PREV DISCUSSION
ISSUED AT 1234 PM EST FRI DEC 19 2025
AVIATION...
THIS MORNING AND AFTERNOON FEATURED SPORADIC POCKETS OF SOME
MODERATE TO HEAVIER SNOW SHOWERS THAT ARE EITHER NOW LEAVING THE
VICINITY OF THE AIRSPACE OR ARE WEAKENING. SNOW SHOWERS WILL
CONTINUE THROUGH THE LATER AFTERNOON HOURS BUT SHOULD MOSTLY REMAIN
FLURRIES OR LIGHT SNOW SHOWERS ARE DRY AIR BEGINS ADVECTING IN FROM
THE WEST. WEST FLOW WITH GUSTS 30 TO 35 KNOTS WILL REMAIN POSSIBLE
THROUGH DAYLIGHT HOURS WITH CEILING HEIGHTS RANGING FROM HIGH-END
MVFR TO LOW VFR (2.5KFT TO 4KFT). ADVENT OF DRY AIR SHOULD GRADUALLY
INCREASE CEILING HEIGHTS TONIGHT BEFORE BACKING TO THE SOUTHWEST,
WHICH WILL ADVECT LOW STRATUS CLOUD COVER NORTH OF ALL TERMINALS.
FOR DTW...LIGHT SNOW SHOWERS WILL BE POSSIBLE THROUGH THE REMAINING
AFTERNOON HOURS, WANING INTO THE EVENING. OTHERWISE, WEST FLOW
PREVAILS, GUSTING UP TO AROUND 30 KNOTS DURING DAYLIGHT HOURS.
DTW THRESHOLD PROBABILITIES...
* HIGH IN CEILINGS AOB 5000 FEET TODAY.
* MEDIUM IN CROSSWINDS THRESHOLDS BEING EXCEEDED THROUGH 4 PM TODAY.
DTX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
LAKE HURON...GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LHZ361>363-421-422-
441>443-462>464.
LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LCZ460.
MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LEZ444.
LOW WATER ADVISORY UNTIL 10 PM EST THIS EVENING FOR LEZ444.
DISCUSSION...BT
MARINE.......MV
AVIATION.....AM
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