017
FXUS63 KDTX 180827
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
327 AM EST WED FEB 18 2026
KEY MESSAGES
- WIDESPREAD PRECIPITATION THIS MORNING. AN ISOLATED THUNDERSTORM
CANNOT BE RULED OUT.
- MILD TEMPERATURES PERSIST THROUGH THURSDAY.
- RENEWED CHANCE FOR RAIN LATE THURSDAY INTO FRIDAY MORNING, WITH
SNOW SHOWER CHANCES BY FRIDAY AFTERNOON OR EVENING.
DISCUSSION
SLOW PROGRESSION OF AN OCCLUDED LOW PRESSURE SYSTEM ACROSS MN HAS
BROUGHT MULTIPLE RIBBONS OF PRECIPITATION TO SE MI TIED TO ENHANCED
SYSTEM RELATIVE ISENTROPIC ASCENT IN THE MID-LEVELS. THESE INITIAL
BANDS WILL CONTINUE TO PROGRESS NORTHEASTWARD THROUGH THE MID-MORNING
HOURS, WHICH WILL EVENTUALLY GIVE WAY TO A MORE DYNAMICALLY ENHANCED
SECOND ROUND, LEADING TO SOME ENHANCED RAINFALL RATES PARTICULARLY
FOR THE TRI-CITIES AND THUMB. ELONGATION OF THE JET STREAM INTO THE
NORTHERN OHIO RIVER VALLEY WILL HELP INDUCE A STRONGER AGEOSTROPHIC
RESPONSE UNDER ENHANCED UPPER-LEVEL DIVERGENCE WHILE A TRIALING
VORTICITY MAXIMUM ROUNDS THE BASE OF THE TROUGH AND PIVOTS INTO SE
MI, LEADING TO THE ENHANCEMENT OF RAINFALL RATES. INSTABILITY LOOKS
TO BE MOSTLY DISJOINTED FROM PRECIPITATION, LEADING TO LOWER END
CHANCES FOR THUNDERSTORMS. HOWEVER, CANNOT RULE OUT SOME ISOLATED
ACTIVITY WITH MID-LEVEL LAPSE RATES HOLDING AROUND 7C/KM.
ALL RAIN TO ABRUPTLY END THROUGH THE LATE MORNING TO EARLY AFTERNOON
AS A PROMINENT MID-LEVEL DRY SLOT RAPIDLY MOVES ACROSS THE GREAT
LAKES WITH SURFACE FLOW BACKING TO THE SOUTHWEST IN THE WAKE OF A
WARM FRONT. THIS FRONT IS PROJECTED TO STALL OUT ACROSS THE CWA,
LIKELY SOMEWHERE ACROSS THE TRI-CITIES AND GREATER PORTION OF THE
THUMB, AND POSSIBLY STALLING FARTHER WEST ACROSS PORTIONS OF
TUSCOLA/LAPEER/ST. CLAIR. TEMPERATURE CONTRAST WILL BE STARK ON
EITHER SIDE OF THE STALLED FRONT, WITH HIGHS MAKING A PUSH TOWARDS
60 (CLOSER TO THE MI/OH BORDER, WHERE TEMPERATURES FAIL TO PUSH OUT
OF THE 40S NORTH OF THE FRONT. BRIEF WINDOW FOR SOME LATE DAY MIXING
ALSO BRINGS POTENTIAL FOR GUSTS AROUND 20-25 MPH WITHIN THE WARM
SECTOR THIS AFTERNOON.
DRY OVERNIGHT AND THROUGH TOMORROW FOR MOST LOCATIONS, WITH LOW-END
RAIN SHOWER CHANCES ACROSS SOUTHERN MICHIGAN AS A WEAK SHORTWAVE
CLIPS THE REGION. ATTENTION WILL THEN TURN TO A SECOND LOW PRESSURE
SYSTEM WHICH WILL DEVELOP ON THE LEE OF THE CENTRAL ROCKIES THURSDAY
MORNING BEFORE STEERING INTO LAKE HURON AND NORTHERN LOWER MICHIGAN
BY FRIDAY, OCCLUDING OVER THE GREAT LAKES. PROJECTED PATH OF THIS
LOW WILL KEEP SE MI WITHIN THE WARM SECTOR, BRINGING RENEWED CHANCES
FOR RAIN SHOWERS THROUGH THE MORNING. CYCLONIC FLOW WILL WRAP COLD
AIR FROM THE PLAINS AROUND THE SOUTHERN QUADRANT OF THIS SYSTEM,
WHICH PENDING TIMING OF THIS CAA, COULD BRING DECREASING
TEMPERATURES THROUGH THE AFTERNOON, ALONG WITH WINDY CONDITIONS AS
STRONGER MIXING DEPTHS INTERACT WITH THE LLJ ALOFT, BRINGING THE
CHANCE TO SEE GUSTS 35-40 MPH. ADDITIONALLY, WRAP AROUND MOISTURE
WITH THE COOLER TEMPERATURES WILL BRING SOME CHANCES FOR SNOW
SHOWERS BY THE AFTERNOON OR EVENING.
COLDER TEMPERATURES TAKE HOLD TO START THE EARLY WEEK PERIOD ALONG
WITH SOME CHANCES FOR SNOW SHOWERS DERIVED FROM LAKE ENHANCEMENT
UNDER THE GREATER TROUGH STRUCTURE.
MARINE
A MARINE DENSE FOG ADVISORY REMAINS IN EFFECT UNTIL LATER THIS
MORNING FOR SOUTHERN LAKE HURON AND LAKE ST. CLAIR, IN THE ABSENCE
OF MEANINGFUL DRYING MECHANISMS. WINDS MAINLY PERSIST OUT OF THE
EAST WITH AN APPROACHING LOW PRESSURE SYSTEM, ALTHOUGH THE SOUTHERN
WATERWAYS COULD FLIP SOUTHWESTERLY GIVEN OTHER SURFACE PRESSURE
ADJUSTMENTS. AN ENERGETIC LOW-LEVEL JET (+45 KNOTS AT 925 MB) IS
MOVING OVERHEAD AS THE MATURE SYSTEM TRACKS NORTHEASTWARD ACROSS
MINNESOTA. THIS SUPPORTS GUSTS TO GALES OVER THE NORTHERN HALF OF
THE HURON BASIN TODAY. A GALE WARNING REMAINS IN PLACE UNTIL LATE
THIS AFTERNOON, BEFORE THE LOW-LEVEL JET AXIS LIFTS INTO THE
NORTHERN GREAT LAKES. THIS SYSTEM WILL ALSO PRODUCE PERIODS OF
RAINFALL, POSSIBLY MIXED WITH SNOW OVER THE NORTHERN WATERWAYS.
CAN'T COMPLETELY RULE OUT A RUMBLE OF THUNDER FURTHER SOUTH. A BRIEF
LULL IN DYNAMICS ENSUES THURSDAY, FAVORING HEADLINE-FREE CONDITIONS.
ANOTHER PERIOD OF ELEVATED WINDS ARRIVES FRIDAY WITH THE NEXT LOW
PRESSURE SYSTEM. POTENTIAL CONTINUES TO INCREASE FOR AN ADDITIONAL
ROUND OF GUSTS TO GALES ACROSS NORTHERN LAKE HURON FRIDAY MORNING.
PREV DISCUSSION
ISSUED AT 1207 AM EST WED FEB 18 2026
AVIATION...
CIGS/VSBYS HAVE BECOME MORE CHAOTIC THE LAST FEW HOURS FIRST LOOKING
TO TREND MORE TO A LOW STRATUS DECK INSTEAD OF DENSE FOG, THEN CIGS
ROSE TO LOW VFR WHILE VSBYS REMAIN IFR. WITH PRECIPITATION LOOMING
IN THE NEXT 1-2 HOURS, WILL TRY TO ADD SOME DETAIL/LOWER CATEGORY
FOR THE TWO MAIN PERIODS OF RAIN THAT WILL PASS THROUGH THE REGION
EARLY THIS MORNING AND AGAIN LATE MORNING/EARLY AFTERNOON. SOME
GUIDANCE STILL SUGGESTS 1/4SM WITH THE SHOWERS BUT SEVERAL MODELS
ARE SHOWING SOME IMPROVEMENT FROM THAT. MUCH DRIER AIR SURGES IN FOR
THE AFTERNOON WITH A RAPID RESPONSE IN CIGS AND VSBYS.
FOR DTW...WILL CONTINUE TO MONITOR CIGS/VSBYS AS THE BOUNCE AROUND A
BIT OVER THE NEXT FEW HOURS. MAINLY MVFR WITH IFR/LIFR POTENTIAL
DURING PERIODS OF RAIN. BEST CHANCE OF FIRST ROUND OF RAIN WILL BE
07-10Z WITH A SECOND ROUND BETWEEN 14-17Z. SCATTERED SHOWERS
POSSIBLE IN BETWEEN AS WELL.
DTW THRESHOLD PROBABILITIES...
* LOW IN CEILINGS AOB 200 FT AND/OR VISIBILITIES BELOW 1/2SM
OVERNIGHT AND WEDNESDAY MORNING.
* HIGH IN CEILINGS AOB 5000 FEET TONIGHT AND WEDNESDAY MORNING.
* HIGH IN PRECIP TYPE AS ALL RAIN TONIGHT.
* LOW IN THUNDERSTORMS OVERNIGHT AND WEDNESDAY MORNING.
DTX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
LAKE HURON...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR LHZ421-422-
441>443-462>464.
GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LHZ361-362.
LAKE ST CLAIR...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR LCZ460.
MICHIGAN WATERS OF LAKE ERIE...NONE.
DISCUSSION...AM
MARINE.......KGK
AVIATION.....DRK
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