494
FXUS63 KDTX 051820
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
220 PM EDT SUN APR 5 2026
KEY MESSAGES
- STRETCH OF COLDER CONDITIONS WILL EXIST TODAY THROUGH TUESDAY WITH
TEMPERATURES REMAINING BELOW NORMAL DURING THIS TIME.
- A FEW LIGHT RAIN OR SNOW SHOWERS ARE POSSIBLE TODAY.
- 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.
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.
PREV DISCUSSION
ISSUED AT 308 AM EDT SUN APR 5 2026
DISCUSSION...
DEEP LAYER COLD AIR ADVECTION ONGOING EARLY THIS MORNING, AS
GOVERNING HEIGHT FALLS SOUTH OF A SOUTHERN CANADIAN CLOSED LOW WORK
TO ESTABLISH BROADER UPPER LEVEL TROUGHING. PEAK IN THE ADVECTIVE
PROCESS EARLY TODAY, BRINGING 850 MB TEMPERATURES DOWN TO AROUND -8C
FOR THE AFTERNOON. TIMING AND MAGNITUDE OF THE ADVECTIVE PROCESS
WILL RESTRICT ANY MEANINGFUL DIURNAL TEMP RECOVERY. THIS ENSURES
TEMPERATURES HOVER IN THE UPPER 30S TO LOWER 40S THROUGH THE DAY.
FIRM WESTERLY GRADIENT WILL MAINTAIN A LEVEL OF GUSTINESS AIDED BY A
DIURNAL INCREASE IN CONVECTIVE DEPTH. PROJECTED WIND MAGNITUDE ACROSS
THE MIXED LAYER WILL CONTINUE TO FAVOR SOME PEAK GUSTS INTO THE 30
TO 35 MPH RANGE. POCKETS OF HEIGHTENED DCVA WITHIN THE BACKDROP OF
GENERAL MID LEVEL CYCLONIC FLOW AND CONTINUED CAA WILL MAINTAIN A
SUPPORTIVE ENVIRONMENT FOR WIDELY SCATTERED SHOWER PRODUCTION OF
LIGHT INTENSITY. FORECAST MAINTAINS A MENTION OF RAIN OR SNOW GIVEN
THE LOWER FREEZING LEVEL.
BENIGN CONDITIONS EXIST THIS EVENING, BEFORE A MID LEVEL WAVE
GLIDING THROUGH THE MEAN TROUGH ARRIVES LOCALLY 06Z-12Z EARLY MONDAY
MORNING. BRIEF SHOT OF MEANINGFUL FORCED ASCENT ANCHORED TO THIS
FEATURE, AFFORDING ANOTHER WINDOW FOR LIGHT PRECIPITATION
PRODUCTION. SOME VARIABILITY YET ACROSS THE MODEL SOLUTION SPACE IN
TERMS OF TRAJECTORY AND ACCOMPANYING PLACEMENT OF RESULTING QPF.
FORECAST WILL OFFER A BROADER AND RELATIVE MODEST STANCE ON
PRECIPITATION CHANCES, BUT SOME UPWARD REVISION IN POPS PLAUSIBLE
ACROSS A SMALLER FOOTPRINT. REGARDLESS, LIGHT AMOUNTS EXPECTED, WITH
MARGINAL TEMPERATURES AGAIN OFFERING A PRECIPITATION TYPE OF RAIN
AND SNOW. DUSTING OF GRASSY ACCUMULATION IN SPOTS BY DAYBREAK. LOWS
RANGING FROM UPPER 20S NORTH TO MID 30S IN PARTS OF METRO DETROIT.
ADDITIONAL SHORTWAVE ENERGY SHEARS THROUGH MONDAY AFTERNOON INTO
MONDAY NIGHT. THIS WILL ESTABLISH A WEAKLY UNSTABLE DIURNAL PROFILE
FOR THE DAYLIGHT PERIOD, AS THE INHERENT COLD MID LEVEL PROFILE
COMBINES WITH DAYTIME HEATING TO YIELD VERY STEEP LAPSE RATES ACROSS
A DEEP LAYER. THIS WILL ALLOW FOR A SCATTERED TO NUMEROUS COVERAGE
OF SHOWERS DURING THE AFTERNOON AND EVENING HOURS, WITH GREATER
COVERAGE WITH NORTHWARD EXTENT. ANY MIDDAY ACTIVITY FAVORS MAINLY
RAIN AS A PRECIPITATION TYPE AS TEMPERATURES PEAK WELL INTO THE 40S,
BUT WITH A TREND TOWARD A MIX OR ALL SNOW TOWARD EVENING AND
OVERNIGHT AS FREEZING LEVELS BECOME MORE SUPPORTIVE. BRIEF HIGHER
INTENSITY SHOWERS MAY ALSO YIELD INSTANCES OF GRAUPEL. DUSTING OF
SNOW IN SOME LOCATIONS ALSO PLAUSIBLE SHOULD ACTIVITY LINGER LONG
ENOUGH INTO THE NIGHT.
COLDEST CONDITIONS THIS FORECAST PERIOD ENTRENCHED MONDAY NIGHT AND
TUESDAY. INBOUND AIRMASS MARKED BY 850 MB TEMPERATURES BELOW -10C
THIS PERIOD. SINGLE DIGIT WIND CHILL PLAUSIBLE IN THE COLDEST
LOCALES TUE AM, WITH DAYLIGHT TEMPERATURES HOLDING IN THE 30S. A
DRYING AND INCREASINGLY STABLE ENVIRONMENT AS HIGH PRESSURE BUILDS
ACROSS THE AREA. WARMING TREND THEN ENSUES FOR THE LATTER HALF OF
NEXT WEEK. NEXT MEANINGFUL SHOT FOR RAINFALL APPEARS TIED TO A COLD
FRONT ATTENDANT TO A DYNAMIC WAVE TRACKING ACROSS THE NORTHERN
CONUS. QUITE A BIT OF MODEL VARIABILITY IN THE SPECIFIC DETAIL WITH
THIS SYSTEM AND FURTHER FORECAST REVISION LIKELY.
MARINE...
COLD ADVECTION ENSUES TODAY IN THE WAKE OF AN EXPANSIVE LOW PRESSURE
SYSTEM DEPARTING THE GREAT LAKES TO THE NORTHEAST. GUSTY WINDS FROM
THE W TO WSW THIS MORNING WILL VEER TO WNW AND NW BY THIS EVENING,
SUSTAINED AT 15 TO 25 KT. A GALE WARNING IS IN EFFECT FOR NORTHERN
AND NORTH-CENTRAL LAKE HURON WHERE CONFIDENCE IS HIGHEST IN A PERIOD
OF 35 KT GALES THROUGH THIS EVENING. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT FOR THE LAKE HURON NEARSHORE WATERS FROM SAGINAW BAY TO
PORT HURON WHERE WINDS ARE FORECAST TO GUST BETWEEN 25 AND 30 KT,
PEAKING MIDDAY. BRIEF GUSTS TO 25 KT ARE POSSIBLE OVER LAKE ST.
CLAIR AND WESTERN LAKE ERIE BUT CONFIDENCE IS TOO LOW FOR A SMALL
CRAFT ADVISORY AT THIS TIME. WINDS WILL WEAKEN TONIGHT AS THE
GRADIENT RELAXES. A CLIPPER SYSTEM PASSES THROUGH ON MONDAY WITH AN
UPTICK IN NORTHWEST WINDS EXPECTED MONDAY NIGHT IN ITS WAKE. LOW
PROBABILITY EXISTS FOR GALES OVER SOUTHERN LAKE HURON. COOLER
NORTHWEST FLOW PERSISTS INTO TUESDAY. FLOW ORGANIZES OUT OF THE
SOUTH ON WEDNESDAY AS THE NEXT LOW PRESSURE SYSTEM TRACKS INTO THE
UPPER MIDWEST.
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.
AVIATION.....MV
DISCUSSION...MR
MARINE.......TF
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