983
FXUS63 KDTX 231000
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
600 AM EDT WED APR 23 2025
KEY MESSAGES
- MUCH WARMER OVER MOST OF THE AREA TODAY THROUGH FRIDAY.
- LOW CHANCES FOR WIDELY SCATTERED SHOWERS AND THUNDERSTORMS THIS
AFTERNOON INTO THE FIRST HALF OF THE NIGHT.
- WIDER SPREAD SHOWERS WITH EMBEDDED THUNDERSTORMS LIKELY FRIDAY
AFTERNOON THROUGH FRIDAY NIGHT AS LOW PRESSURE LIFTS THROUGH THE
GREAT LAKES.
- DRY AND SEASONABLE THIS WEEKEND AS HIGH PRESSURE DRIFTS OVER.
AVIATION
INTERVALS OF HIGHER MID LEVEL MOISTURE WILL CONTINUE TO LIFT ACROSS
THE AREA THIS TAF PERIOD. THIS OCCURS AS A WARM FRONTAL BOUNDARY
DRIFTS NORTHWARD, LEADING TO THE DEVELOPMENT OF HIGHER BASED VFR
CLOUD WITH A FOCUS ON THE AFTERNOON AND EVENING PERIODS. THIS WILL
ALSO BRING THE CHANCE FOR SHOWERS AND THUNDERSTORMS LATE
AFTERNOON AND EVENING /MAINLY AFTER 19Z/, WITH SLIGHTLY HIGHER
PROBABILITY FROM PTK NORTHWARD BASED ON LATEST MODEL OUTPUT.
FORECAST WILL CONTINUE TO OUTLOOK THIS PERIOD FOR POSSIBLE TSRA.
MODEST WINDS FROM THE SOUTH TO SOUTHWEST TODAY.
FOR DTW...MAIN WINDOW FOR ISOLATED TSRA BETWEEN 19Z AND 22Z.
DTW THRESHOLD PROBABILITIES
* LOW FOR CEILING AT OR BELOW 5000 FEET TODAY.
* LOW FOR THUNDERSTORMS LATE THIS AFTERNOON.
PREV DISCUSSION
ISSUED AT 335 AM EDT WED APR 23 2025
DISCUSSION...
NEAR ZONAL UPPER PATTERN CONTINUES FOR THE MIDWEEK PERIOD ALLOWING A
SERIES OF DIFFUSE, DUMPY SHORTWAVES TO SLIDE OVER THE GREAT
LAKES/LOWER MI. THESE DISTURBANCES AID IN BOTH LIFTING A WEAK WARM
FRONTAL BOUNDARY NORTH TOWARDS CENTRAL LOWER MI TODAY AS WELL AS
ADVECTING PERIODIC WAVES OF MID-LEVEL MOISTURE INTO THE STATE
SUPPORTING WIDELY SCATTERED SHOWERS AND STORMS (AS SEEN EARLY THIS
MORNING). OVERALL POPS REMAIN FAIRLY BROAD-BRUSHED AT 20-30% IN
RUNNING FORECAST AS WEAKER FORCING COMBINED WITH SENSITIVITY TO
FRONTAL POSITIONING AND UNCERTAINTY TO WHAT DEGREE REMNANT PIECES OF
UPSTREAM CONVECTION SURVIVE THE LOCAL DRIER LOW LEVEL AIRMASS ALL
LEND TO A LOW PREDICTABILITY, NEBULOUS RAIN COVERAGE. A BREAK IN
RAIN CHANCES IS LIKELY BY MID MORNING THROUGH EARLY AFTERNOON AS THE
FIRST WAVE KICKS EAST OF THE REGION. THESE CHANCES THEN RETURN LATE
AFTERNOON-EVENING AS A SECOND WAVE (CURRENTLY GENERATING CONVECTION
OVER IOWA) REACHES THE WESTERN GREAT LAKES. SAID CONVECTIVE REMNANTS
REACH SE MI BETWEEN ~18-22Z HOWEVER THE RESIDENT LOW LEVEL DRY
AIRMASS WORKS TO WEAKEN ACTIVITY LIKELY ONLY RESULTING IN SPOTTY
SHOWERS/STORMS. ADDITIONAL SCATTERED CONVECTION TIED TO A SURGE IN
THETA-E ADVECTION THEN PUSHES IN FROM THE WESTERN GREAT LAKES
BETWEEN ~00-06Z WITH BEST COVERAGE NORTH OF M-59- OWING TO CLOSER
PROXIMITY TO THE PV ANOMALY TRACKING OVER CENTRAL LOWER MI. IN BOTH
WINDOWS, LAPSE RATES HOVER AROUND 6.5-7 C/KM WITH MLCAPE'S SITTING
AT SEVERAL HUNDRED J/KG SUPPORTING THE CHANCES FOR SOME EMBEDDED
ELEVATED THUNDERSTORMS WITHIN WIDER SHOWERS. 0-6KM SHEAR AROUND
35KTS WILL OFFER A LOW, BUT NON-ZERO, SHOT FOR AN ISOLATED ORGANIZED
STORM WHICH WOULD BE CAPABLE OF GENERATING HAIL.
WEAK MID-LEVEL HEIGHT RISES ATTEMPT TO BUILD OVER SOUTHERN LOWER MI
THURSDAY SUPPRESSING/GREATLY LIMITING ANY PRECIP FROM SHORTWAVES
STILL TRAVERSING OVER NORTHERN LOWER MI. THE MAJORITY OF THE AREA IS
EXPECTED TO STAY DRY AS A RESULT, THOUGH THERE IS A POTENTIAL
EXCEPTION. THERE IS SIGNAL AMONG SOME HIGH-RES (AND COARSER MODELS
LIKE THE 00Z RGEM) FOR A BACKDOOR COLD FRONT-LAKE BREEZE HYBRID,
DRIVEN BY WEAK SURFACE HIGH PRESSURE OVER NORTHERN LAKE HURON, TO
DROP ACROSS THE NORTHERN HALF OF THE CWA, DOWN TO ROUGHLY THE I-69
CORRIDOR. SOLUTIONS ARE DIVIDED ON THE STRENGTH OF THIS LOW LEVEL
FORCING TO GENERATE POP-UP (THUNDER)SHOWERS SO FOR NOW HAVE ONLY
INSERTED A BASE SLIGHT CHANCE (15%) POP TO HIGHLIGHT. DEEPER LAYER
SOUTH TO SOUTHWEST FLOW BELOW 500MB MAINTAINS WARM ADVECTION INTO
THE AREA INCREASING 850MB TEMPS TO 10-11C AND SUPPORTING HIGHS
AROUND 80 THURSDAY FOR AREAS SOUTH OF I-69. FOR AREAS NORTH, IT
DEPENDS HIGHLY ON THE AFOREMENTIONED BACKDOOR COLD FRONT WHICH WOULD
CREATE A DECENT NORTH-SOUTH TEMPERATURE GRADIENT WITH HIGHS IN THE
MID TO UPPER 70S NEAR I-69 AND ONLY 60S IN THE THUMB.
LARGE SHORTWAVE EJECTS OUT OF THE SOUTHERN PLAINS LATE THURSDAY AND
LIFTS NORTHEAST OVER THE GREAT LAKES FOR FRIDAY. RAIN LOOKS TO
ARRIVE BY LATE MORNING-EARLY AFTERNOON AS WIDESPREAD SHOWERS WORK
ACROSS THE AREA THROUGH FRIDAY NIGHT. SCATTERED EMBEDDED
THUNDERSTORMS ALSO LIKELY, MAINLY IN THE AFTERNOON-EVENING
TIMEFRAME, AS A FEW HUNDRED J/KG OF MLCAPE DEVELOP WITH PEAK DIURNAL
HEATING. FLATTER MID-UPPER WAVE DECREASES THE DEGREE TO WHICH GULF
MOISTURE IS ABLE TO GET ADVECTED THIS FAR NORTH WITH THE CORE
HOLDING TO OUR SOUTH OVER THE OHIO VALLEY. THAT SAID PW VALUES STILL
INCREASE OVER 1", WELL WITHIN THE 90TH PERCENTILE FOR THE DAILY
CLIMO, SUPPORTING FOR HEAVIER DOWNPOURS AND A SOAKING RAIN WITH QPF
LOOKING TO FALL GENERALLY BETWEEN 0.3-0.6" (SOME LOCALLY HIGHER
AMOUNTS POSSIBLE GIVEN T-STORM CHANCES). BROAD NORTHERN PLAINS HIGH
PRESSURE BUILDS IN BY EARLY SATURDAY MORNING ENDING FURTHER RAIN
CHANCES WITH DRY CONDITIONS HOLDING THROUGH THE WEEKEND AS IT DRIFTS
OVERHEAD.
MARINE...
LIGHT WINDS CONTINUE THROUGH THE MIDWEEK PERIOD UNDER THE GUISE OF
HIGHER PRESSURE AND A WEAKER PRESSURE GRADIENT. ANY LOCALIZED HIGHER
WIND SPEEDS WILL BE FOUND ACROSS NORTHERN LAKE HURON WITH THE
SOUTHEAST FLOW, WHERE GUSTS AROUND 20 KNOTS WILL BE POSSIBLE THIS
AFTERNOON AND EVENING. OTHERWISE, THERE WILL BE THE CHANCE FOR
SHOWERS OR AN ISOLATED THUNDERSTORM CENTERED OVER LAKE ERIE INTO
LAKE ST. CLAIR TODAY, WITH ADDITIONAL LOW END CHANCES EXTENDING INTO
LAKE HURON LATE TONIGHT INTO TOMORROW MORNING. THE BETTER CHANCES
FOR MORE WIDESPREAD ACTIVE WEATHER AND ELEVATED WINDS ENTER FRIDAY
AS THE NEXT LOW PRESSURE SYSTEM ARRIVES OVER THE STATE.
DTX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
AVIATION.....MR
DISCUSSION...KDK
MARINE.......AM
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