495
FXUS63 KDTX 051921
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
321 PM EDT SUN APR 5 2026
KEY MESSAGES
- STRETCH OF COLDER CONDITIONS WILL EXIST TONIGHT THROUGH TUESDAY
WITH TEMPERATURES REMAINING BELOW NORMAL DURING THIS TIME.
- POTENTIAL FOR A MIX OF LIGHT RAIN AND SNOW EXISTS LATE TONIGHT AND
AGAIN MONDAY AFTERNOON INTO MONDAY NIGHT. A DUSTING OF ACCUMULATION
ON GRASSY SURFACES WILL BE POSSIBLE.
- THE NEXT GOOD CHANCE FOR RAIN WILL BE THURSDAY INTO FRIDAY.
DISCUSSION
A BRIEF INTERVAL OF BELOW TO WELL BELOW NORMAL TEMPERATURES CAN BE
EXPECTED THE NEXT COUPLE DAYS AS THE GREAT LAKES REGION RESIDES
ALONG THE SOUTHERN EDGE OF THE BROAD UPPER LEVEL TROUGH UNDER DEEP
LAYER NORTHWEST FLOW. BRIEF MID LEVEL SUBSIDENCE/NEGATIVE
DIFFERENTIAL VORTICITY ADVECTION WILL SUSTAIN DRY CONDITIONS THROUGH
THE FIRST HALF OF THE NIGHT AND WILL ALLOW SOME PARTIAL CLEARING
THIS EVENING. A MID LEVEL SHORT WAVE IMPULSE NOW OVER NRN MN WILL
QUICKLY MOVE ACROSS SE MI OVERNIGHT. THE RESULTING LARGE SCALE SCALE
ASCENT AND DEEP LAYER MOISTURE WILL SUPPORT A CHANCE OF SHOWERS.
STEEP MID LEVEL LAPSES RATES WILL RESULT IN A CONVECTIVE COMPONENT
TO THE SHOWERS. A SUBTLE LOW LEVEL WARM LAYER WILL ADVECT INTO THE
SOUTHERN PORTIONS OF THE AREA OVERNIGHT, SUPPORTING A RAIN OR
RAIN/SNOW MIX IN THE SOUTH. THE THERMAL PROFILE WILL BE COLD ENOUGH
TO SUPPORT WET/MELTING SNOW IN THE NORTH.
THE PASSAGE OF THIS WAVE WILL USHER IN A REINFORCING SHOT OF COLD
AIR MONDAY INTO TUESDAY. STEEPENING LOW LEVEL LAPSE RATES AS A
RESULT OF COLD AIR ADVECTION AND DAYTIME HEATING MONDAY WILL RESULT
IN EXPANDING DIURNAL CU AND SHOWERS MON AFTERNOON. WHILE TEMPS ARE
EXPECTED TO REBOUND INTO THE 40S ACROSS MOST OF THE AREA, LOW WET
BULB ZERO HEIGHTS WILL SUPPORT SOME SNOW IN THE HEAVIER CONVECTIVE
SHOWERS, ESPECIALLY ACROSS THE NORTHERN HALF OF THE FORECAST AREA.
GIVEN FORECAST WEAK SURFACE BASED INSTABILITY, SOME OF THESE SHOWERS
MAY PRODUCE BRIEF INTENSE SNOWFALL RATES. THERE IS SOME INDICATION
IN A FEW HI RES SOLUTIONS OF AN EXPANDING REGION OF LOW LEVEL
CONVERGENCE DEVELOPING ALONG A SURFACE COLD FRONT/TROUGH AXIS
SLIDING SOUTH MONDAY EVENING/NIGHT, WARRANTING A LINGERING CHANCE OF
SNOW SHOWERS. THE PUSH OF COLD AIR BEHIND THIS IS QUITE IMPRESSIVE
FOR EARLY APRIL AS 850MB TEMPS DROP INTO THE NEGATIVE TEENS. THIS
WILL DRIVE MON NIGHT LOWS INTO THE 20S AND WILL WARRANT TUESDAY
HIGHS ONLY IN THE 30S TO NEAR 40. STRONG HIGH PRESSURE EXPANDING
ACROSS THE REGION WILL AT LEAST SUPPORT DRY CONDITIONS ON TUESDAY.
A WARMING TREND WILL THEN ENSUE WEDNESDAY INTO THURSDAY WITHIN THE
RETURN FLOW OF THE DEPARTING SFC HIGH AND IN ADVANCE OF A CLOSED MID
LEVEL WAVE FORECAST TO MOVE ALONG THE CNTL US/CANADIAN BORDER
REGION. AS THIS WAVE LIFTS NORTH OF THE REGION, IT IS FORECAST TO
DRAG AN ASSOCIATED COLD FRONT INTO LOWER MI, PARALLELING THE MID
LEVEL FLOW. THE BROAD ARRAY OF ENSEMBLE GUIDANCE GENERALLY SUGGESTS
HIGH CHANCES FOR RAIN LATE IN THE WEEK DUE TO THE PROJECTED SLOW
MOVEMENT OF THIS FRONT.
MARINE
THE PRESSURE GRADIENT AND COLD ADVECTION WEAKEN TONIGHT, ALLOWING
WNW WIND TO SUBSIDE AND CURRENT HEADLINES TO EXPIRE. A CLIPPER
SYSTEM PASSES THROUGH ON MONDAY BRINGING SNOW SHOWERS AND AN UPTICK
IN NORTH TO NORTHWEST WINDS MONDAY NIGHT IN ITS WAKE. GUSTS MONDAY
NIGHT ARE FORECAST TO PEAK BETWEEN 25 AND 30 KT BEFORE WEAKENING
TUESDAY MORNING. HIGH PRESSURE BUILDS IN BRIEFLY ON TUESDAY, THEN
FLOW STRENGTHENS OUT OF THE SOUTH ON WEDNESDAY AS THE NEXT LOW
PRESSURE SYSTEM TRACKS INTO THE UPPER MIDWEST. THIS SYSTEM WILL SEND
A SLOW-MOVING COLD FRONT ACROSS THE GREAT LAKES THURSDAY AND FRIDAY.
PREV DISCUSSION
ISSUED AT 220 PM EDT SUN APR 5 2026
AVIATION...
LOW PRESSURE NOW OVER QUEBEC HAS LEFT BROAD CYCLONIC FLOW IN PLACE
ACROSS THE GREAT LAKES. LOW VFR CEILINGS AND BREEZY WEST FLOW (GUSTS
TO 30 KNOTS) WILL PERSIST THROUGH THE REMAINDER OF THE AFTERNOON
BEFORE CONDITIONS IMPROVE TONIGHT AS WINDS SUBSIDE AND SKIES CLEAR.
ANY CLEARING WILL BE BRIEF TONIGHT BEFORE A QUICK-HITTING CLIPPER
ARRIVES EARLY MONDAY MORNING. THIS SYSTEM LACKS DEEP MOISTURE, BUT
SHOULD HAVE ENOUGH INSTABILITY AND LAKE ENHANCEMENT TO PRODUCE A
WINDOW OF RAIN AND/OR SNOW SHOWERS BETWEEN ROUGHLY 08Z AND 14Z. THE
INSTABILITY COMPONENT OF THIS SYSTEM RESULTS IN VARIABLE
PRECIPITATION RATES AND P-TYPES, SO EXPECT CIG/VSBY RESTRICTIONS TO
BE VARIABLE THROUGHOUT THE MORNING AS WELL. ADDITIONAL SCATTERED
RAIN-SNOW SHOWERS REMAIN POSSIBLE IN THE AFTERNOON AS BOUNDARY LAYER
INSTABILITY STAYS IN TACT.
DTW THRESHOLD PROBABILITIES...
* HIGH FOR CEILING AT OR BELOW 5000 FT THROUGH THIS AFTERNOON. LOW
THIS EVENING. MEDIUM MONDAY.
* MODERATE FOR PTYPE TO BE RAIN/SNOW MIX MONDAY MORNING AND MONDAY
AFTERNOON.
DTX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LHZ421-422-
441>443.
GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR LHZ361-362.
LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LCZ460.
MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LEZ444.
DISCUSSION...SC
MARINE.......TF
AVIATION.....MV
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