745
FXUS63 KDTX 140945
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
445 AM EST SUN DEC 14 2025
KEY MESSAGES
- BITTER COLD TEMPERATURES TODAY. THE COLDEST PERIOD WILL BE THIS
MORNING WITH WIND CHILLS RANGING BETWEEN 5 BELOW ZERO AND 15 DEGREES
BELOW ZERO.
- LAKE EFFECT SNOW BANDING POSSIBLE ALONG THE EASTERN THUMB
SHORELINE OF HURON AND SANILAC COUNTIES TODAY. SNOW ACCUMULATIONS OF
2 TO 4 INCHES ARE POSSIBLE IF SNOW BANDING DOES PUSH INLAND OFF OF
LAKE HURON.
- A WARMUP IS FORECASTED FOR THE MIDDLE OF THE WEEK WITH
TEMPERATURES NEAR TO SLIGHTLY ABOVE NORMAL WEDNESDAY AND SOME 8 TO
10 DEGREES ABOVE NORMAL THURSDAY.
- A STRONG STORM SYSTEM IS FORECASTED TO IMPACT THE GREAT LAKES
REGION THURSDAY AND INTO FRIDAY. MUCH OF THE PRECIPITATION IS
EXPECTED TO FALL IN THE FORM OF RAIN WITH THE SIGNIFICANT IMPACT OF
THE STORM SYSTEM COMING FROM STRONG WINDS.
AVIATION
WINDS JUST ABOVE THE SURFACE HAVE COME AROUND TO THE NORTHWEST,
WHICH HAS ALLOWED DRIER AIR AND CLEARING TO WORK INTO MOST OF
SOUTHEAST MICHIGAN. ANOTHER PUSH OF MOISTURE/CLOUDS FROM LAKE
SUPERIOR-LAKE MICHIGAN WILL SPREAD IN LATE THIS MORNING, ALONG WITH
SCATTERED FLURRIES/LIGHT SNOW SHOWERS. MOSTLY LOW VFR CIGS EXPECTED
THIS AFTERNOON, BUT AREAS OF HIGH MVFR IN SNOW SHOWERS. INCREASED
MIXING DEPTHS WILL SUPPORT NORTHWEST WIND GUSTS AROUND 25 KNOTS MID
DAY, QUICKLY DIMINISHING IN THE EARLY EVENING. WINDS WILL BACK WEST-
SOUTHWEST THIS EVENING/TONIGHT, BUT UNCERTAINTY WITH HOW WELL THE
SOUTHERN LAKE MICHIGAN CLOUDS/FLURRIES WILL SPREAD EAST AND IMPACT
THE TAF SITES OVERNIGHT.
FOR DTW...CIGS UNDER 5000 FEET TO REDEVELOP LATE THIS MORNING AND
AFTERNOON, WITH OCCASIONAL FLURRIES LIKELY RETURNING AS WELL.
DTW THRESHOLD PROBABILITIES...
* LOW FOR CIGS AOB 5000 FEET, EXCEPT MEDIUM TOWARD NOON AND THIS
AFTERNOON.
* HIGH FOR PRECIP TYPE BEING SNOW.
PREV DISCUSSION
ISSUED AT 323 AM EST SUN DEC 14 2025
DISCUSSION...
A POLAR VORTEX AMIDST DEEPER PLANETARY VORTICITY RESERVOIR IS
CURRENTLY CENTERED IN VICINITY OF NORTHERN LAKE HURON THIS MORNING.
THE LOW HEIGHT ANOMALY, DISTINGUISHED BY H5 HEIGHTS OF SUB 510DAM AND
850MB TEMPERATURES OF -24C WILL PIVOT DIRECTLY ACROSS SOUTHEAST
MICHIGAN BETWEEN 12-18Z. SPIN DOWN OF VORTICITY WILL CAUSE AN
EXCITEMENT OF THE LAKES WITH INDUCTIONS OF VARIOUS MESOLOW FEATURES
OVER THE BIGGER LAKE BASINS OF THE GREAT LAKES. THE MAIN QUESTION
HAS BEEN WHETHER ANY CONVERGENCE BANDING WILL BE SHOVED INLAND OVER
THE FAR EASTERN THUMB SHORELINE BEFORE BECOMING SHORE PARALLEL FOR A
TIME. REALLY A CONDITIONAL, ALL-OR-NOTHING TYPE OF FORECAST WITH
DIFFERING HIRES SOLUTIONS. THE HRRR RUNS ARE THE MOST BULLISH WITH
SOME AGREEMENT FROM THE ARW FOR PUSHING INLAND, WHILE THE 3KM NAM
AND RGEM/HRDPS SOLUTIONS SUGGEST MOST OF THE LAKE EFFECT SNOW WILL
REMAIN OFFSHORE. LOCAL TIME-LAGGED ENSEMBLE OUTPUT IS MIXED AT SITE
P58 WITH HIGH PROBABILITY >80% TO MEASURE BUT LOW PROBABILITIES <30%
FOR A 0.5 INCH SNOW. THE SAME TIME-LAGGED ENSEMBLE SYSTEMS
CONVECTIVE METHOD ALSO CALCULATES AN APPROXIMATE 30% CHANCE FOR 1
INCH OF SNOW. NBM DATA IS SUGGESTING A MISS WITH 60-70%
PROBABILITIES FOR 0.1 INCH, 0% PROBABILITY OF 2 INCHES, ALONG THE
SHORELINE AREAS OF HURON AND SANILAC COUNTIES. LAKE EFFECT
PARAMETERS ARE VERY GOOD FOR CONVECTIVE ACTIVITY WITH WATER
TEMPERATURES IN THE LOWER 40S PROVIDING FOR LAKE-850MB DELTA TS OF
AT LEAST -20C AND LAKE INDUCED CAPE VALUES REACHING/EXCEEDING 900
J/KG. OBSERVED SNOW AMOUNTS WILL OBVIOUSLY BE DEPENDENT ON RESIDENCE
TIME/OR THE LACK THEREOF OF ONSHORE SNOW BANDING LATER TODAY. ANY
BANDING IS EXPECTED TO RESULT IN HOURLY SNOWFALL RATES OF 1 PER HOUR
OR POSSIBLY MORE. OUT OF RESPECT FOR LAKE EFFECT PARAMETERS, DID
INCREASE SNOW AMOUNTS INTO THE 2 TO 4 INCH RANGE, AGAIN CONDITIONAL
TO BANDING MOVING INLAND. A SHORT-FUSED WINTER WEATHER ADVISORY MAY
BE NEEDED.
FAST NORTHWEST FLOW WILL DEVELOP LATE TONIGHT AND MONDAY AS BROAD
RIDGING AND SUPERGEOSTROPHIC FLOW EXPANDS AND REACHES INTO LOWER
MICHIGAN. RISING GEOPOTENTIAL HEIGHTS HELPS SURFACE ANTICYCLONE
BUILD INTO SOUTHEAST MICHIGAN WITH A WEAKER SURFACE WIND LIMITING
WIND CHILLS INTO THE SINGLE DIGITS BELOW ZERO MONDAY MORNING. EXIT
REGION TO UPPER LEVEL SPEED MAX AND ATTENDANT WEAK PACIFIC SHORTWAVE
IS EXPECTED TO RESULT IN WEAK SYNOPTIC LIFT OVER THE FORECAST AREA
DURING THE DAYTIME MONDAY. CHANGING FLOW CURVATURE IS EXPECTED TO
RESULT IN A WAVE OF WARM ADVECTION ALOFT. FORECAST SOUNDINGS WITH
VERTICAL UVV PROFILES SUGGESTS SATURATION AND LIFT WILL BE VERY HIGH
UP IN THE COLUMN AT/ABOVE 8.0 KFT AGL WITH A CONSIDERABLE AMOUNT OF
DRY AIR HOLDING IN THE LOWEST 6.0 KFT AGL PARTICULARLY SOUTH OF I 69
CORRIDOR. PLAN VIEW OF MOISTURE ON ISENTROPIC SURFACES REALLY
SUPPORTS THE IDEA OF A DRY AIR FEED INTO SOUTHEAST MICHIGAN FROM
GUSTY SOUTHWESTERLIES. THE OFFERED GUIDANCE OF 30 TO 80% POPS FOR
THE NORTHERN 2/3RDS OF THE CWA APPEARS REASONABLE. SNOW AMOUNTS OF A
LESS THAN AN INCH IN THE THUMB ALSO APPEARS REASONABLE.
RELATIVELY QUIET WEATHER FOR THE MIDDLE OF THE WEEK TUESDAY AND
WEDNESDAY AS FLOW EVOLVES MORE ZONAL AND BROAD RIDGING INFLUENCES
THE REGION. NOT A WHOLE LOT TO TALK ABOUT RIGHT NOW, BUT MANY OF THE
DAYS ARE EXPECTED TO BREEZY TO WINDY. NEAR TO SLIGHTLY ABOVE NORMAL
TEMPERATURES ARE EXPECTED WEDNESDAY WITH READINGS 5 TO 10 DEGREES
ABOVE NORMAL THURSDAY.
MODELS HAVE SHOWN CONTINUITY IN A DEEP MIDLEVEL TROUGH PUSHING INTO
THE INTERIOR OF THE US WEDNESDAY RESULTING IN A STRONG BAROCLINIC
ZONE IMPACTING THE GREAT LAKES THURSDAY. EARLY INDICATIONS ARE THIS
WILL BE AN ENERGETIC WIND PRODUCER WITH THE POTENTIAL FOR VERY
STRONG WINDS WITH A BULK OF THE PRECIPITATION OCCURING IN THE WARM
SECTOR. UNCERTAINTY AT THIS TIME IS A RESULT OF DIFFERENCES IN
TIMING OVER SOUTHEAST MICHIGAN.
MARINE...
THE ARCTIC FRONT IS NOW EAST OF THE AREA WHICH HAS LET THE COLD AIR
BEGIN TO FILTER INTO THE REGION THROUGH THE DAY. THE COLDEST OF THE
ARCTIC AIR WILL ARRIVE OVERNIGHT INTO SUNDAY MORNING WITH A
SECONDARY FRONT TURNING WINDS A BIT MORE TO THE NORTHWEST FROM WEST.
WIND SPEEDS WILL CONTINUE TO BE IN THE MID 20 KNOT RANGE WITH GUSTS
UP TO AROUND 30 KNOTS. THE NORTHWESTERLY FLOW WILL PUSH THE HIGHER
WAVES ALONG THE LAKE HURON SHORELINE OF THE THUMB RESULTING IN SMALL
CRAFT ADVISORIES THE REST OF THE DAY THROUGH SUNDAY NIGHT. THE COLD
AIRMASS AND ELEVATED WINDS WILL ALSO LEAD TO POTENTIAL SNOW SQUALLS
AND FREEZING SPRAY AS WELL DURING THIS TIME. MONDAY WILL AGAIN
FEATURE ELEVATED WIND SPEEDS AS THE NEXT SYSTEM TRACKING THROUGH
SOUTHERN CANADA RUNS UP AGAINST A HIGH PRESSURE SYSTEM CENTERED OVER
MUCH OF THE EASTERN CONUS. THE TIGHTENING OF THE PREFRONTAL GRADIENT
ALONG WITH COLD UNSTABLE AIR WILL LEAD TO ANOTHER PERIOD OF WIND
GUSTS NEARING GALE FORCE. CURRENTLY THERE IS A LARGE SPREAD IN THE
MODEL GUIDANCE SOLUTIONS AS TO WHAT MAX GUSTS WILL BE ACHIEVABLE BUT
SEVERAL HOURS OF GALES MAY BE POSSIBLE MONDAY AFTERNOON.
DTX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
LAKE HURON...GALE WATCH FROM MONDAY MORNING THROUGH MONDAY AFTERNOON FOR LHZ362-
363-421-422-441-462.
SMALL CRAFT ADVISORY UNTIL 4 AM EST MONDAY FOR LHZ421-441.
SMALL CRAFT ADVISORY UNTIL 4 AM EST MONDAY FOR LHZ442-443.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
AVIATION.....SF
DISCUSSION...CB
MARINE.......DRK
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page