290
FXUS63 KAPX 290348
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1148 PM EDT MON APR 28 2025
KEY MESSAGES
- WIDESPREAD THUNDERSTORMS TONIGHT AND TUESDAY MORNING WITH CHANCES
FOR SCATTERED SEVERE STORMS
- RAIN CHANCES RE-EMERGE ON THURSDAY, LINGERING INTO FRIDAY.
- COOLER FRIDAY INTO SATURDAY.
- PERIOD OF WARM AND MOSTLY DRY CONDITIONS POSSIBLE IN THE EXTENDED
RANGE (~MAY 5 AND BEYOND).
UPDATE
ISSUED AT 931 PM EDT MON APR 28 2025
GENERAL IDEA REMAINS UNCHANGED, WITH UPSTREAM CONVECTION
EXPECTED TO WORK EAST INTO THE AREA OVERNIGHT. UNCERTAINTY ON
OVERALL STORM ORGANIZATION AND COVERAGE REMAINS SIGNIFICANT AS
WANING INSTABILITY INTERCEPTS STILL EXCELLENT DEEP LAYER SHEAR.
MOISTURE ADVECTION IS INCREASING RATHER SIGNIFICANTLY, AT LEAST
SUPPORTING SOME MAINTENANCE OF UPSTREAM ACTIVITY AS IT HEADS
EAST. SPC STILL HIGHLIGHTS EASTERN UPPER AND NORTHWEST LOWER AS
HAVING THE GREATEST POTENTIAL OF SEVERE STORMS TONIGHT...WITH
WINDS AND HAIL BEING THE PRIMARY SEVERE WEATHER CONCERNS. WILL
SIMPLY CONTINUE TO MONITOR AND SEE HOW THINGS UNFOLD OVER THE
NEXT SEVERAL HOURS.
SHORT TERM /THROUGH TUESDAY/
ISSUED AT 320 PM EDT MON APR 28 2025
FORECAST SYNOPSIS: CURRENT SATELLITE AND RADAR DEPICT AREAS OF
THUNDERSTORM ACTIVITY OVER THE WESTERN UPPER PENINSULA AND WESTERN LK
SUPERIOR THIS AFTERNOON. THIS IS DRAPING SOME HIGH CLOUDS OVER
NORTHERN MI, HOWEVER AMPLE SUNSHINE IS STILL REACHING THE SURFACE IN
MOST SPOTS. TEMPERATURES ARE QUICKLY RISING INTO THE HIGH 60S AND
LOW 70S ACROSS NORTHERN MI. CRITICAL FIRE WEATHER CONDITIONS DUE TO
FREQUENTLY GUSTY SOUTHERLY WINDS PERSISTING DRY AIR NEAR THE
SURFACE. THESE CONDITIONS WILL PERSIST THROUGH THE LATE AFTERNOON
HOURS AS MIXING HEIGHTS RISE TO AROUND 4 KFT AND MIX OUT ANY
MOISTURE THAT TRIES TO SEEP IN FROM THE WEST. NE LOWER WILL SEE
THESE CONDITIONS LINGER INTO THE EVENING, HOWEVER MID AND LL
MOISTURE WILL FINALLY MAKE ITS WAY OVER LK MI AND TO NW LOWER. A
SURFACE CYCLONE WILL REACH WI AND MOVE A WARM SECTOR OVER THE STATE
AFTER MIDNIGHT. THIS WARM SECTOR WILL HAVE A LLJ OF AROUND 60 TO 70
KTS AT 2-5 KFT. DURING THIS TIME, THERE WILL BE A SW/NE AXIS OF
UPPER LEVEL FORCING DRAPED OVER WI/MN AND THROUGH LK SUPERIOR. THESE
FEATURES WILL START TO DIP SE AROUND MIDNIGHT, YIELDING STRONG SHEAR
(BULK 0-6KM UP TO 50 OR EVEN 60KTS) AND LIFT (MID AND LL OMEGA) OVER
NORTHERN MI. AROUND 500 TO 1200 J/KG OF ELEVATED INSTABILITY WILL
EXIST ON TOP OF THIS, AND IN SOME SPOTS (NEAR MANISTEE AND WEXFORD
CO.) A FEW HUNDRED SFC/ML INSTABILITY EXISTS. DRY AIR ALOFT (600 MB
AND ABOVE) WILL BE PRESENT THROUGHOUT THE NIGHT, LEADING TO
HEALTHY MID LEVEL LAPSE RATES OF +7 C/KM.
PUTTING THIS ALL TOGETHER, AN INITIAL ROUND OF ISOLATED THUNDER
STORMS ARE POSSIBLE OVER EASTERN UPPER AND NW LOWER THIS
EVENING AND TONIGHT (BEFORE MIDNIGHT). A LINE OF STORMS WILL
LIKELY SPROUT OVER CENTRAL WI AND THE U.P. ORIENTATED FROM SW-
NE. THIS WILL MOVE ACROSS NORTHERN MI, REACHING THE WESTERN
COAST OF LK HURON BY SUNRISE TUESDAY. CHANCES REMAIN FAVORABLE
FOR A HANDFUL OF THESE STORMS TO PRODUCE DAMAGING WINDS AND SOME
LARGE HAIL. THERE IS A NON-ZERO CHANCE FOR A TORNADO OR TWO
WITH THE VERY FAVORABLE SHEAR ENVIRONMENT WHILE CLOUD BASES
TEMPORARILY DIP.
THE FRONT WILL MOVE THROUGH TUESDAY MID MORNING, WHICH COULD RESULT
IN MORE THUNDERSTORM ACTIVITY FOR NE LOWER AS THIS IS WHERE THE BEST
ENVIRONMENT WILL REMAIN TOMORROW MORNING.
WINDS WILL BE BREEZY OVERNIGHT, HOWEVER THERE IS LOW CONFIDENCE FOR
WIDESPREAD STRONG GUSTS AS MIXING HEIGHTS WILL BE CAPPED (MOST
INSTABILITY REMAINS ELEVATED). WINDS TURN WEST TUESDAY AND
STRENGTHEN AND BECOME FREQUENTLY GUSTY.
FORECAST CONFIDENCE AND CONCERNS: A CHAOTIC ENVIRONMENT, SUCH AS
WHAT IS FORECASTED TONIGHT, RESULTS IN A FEW UNCERTAINTIES. LETS
START WITH THE MORE CERTAIN THOUGHTS. THERE WILL BE THUNDERSTORM
ACTIVITY ACROSS NORTHERN MI TONIGHT, RESULTING IN LIGHTNING, WETTING
RAINS AND GUSTY OUTFLOW WINDS. THE COOL LAKES WILL TEMPORARILY
HURT STORM DEVELOPMENT, HOWEVER BACKGROUND FORCING AND FAVORABLE
MID AND LL ENVIRONMENTS SHOULD KEEP ACTIVITY ALIVE. THE
COVERAGE AND STRENGTH ARE WHAT COULD CHANGE AS STORMS MOVE OVER
LAND. IF A LINE OF STORMS BECOMES MORE DEFINED, IT WILL BECOME
PARALLEL WITH MID LEVEL FLOW AS IT REACHES THE SHORES OF NW
LOWER AND HAVE WHAT IT NEEDS TO SUSTAIN ITS DEFINITION AS IT
CROSSES THE PENISULA. THIS COULD RESULT IN MORE WIDESPREAD
DAMAGING WINDS. CAMS DON'T REFLECT THIS SCENARIO, HOWEVER IT
DEPENDS HEAVILY ON HOW CONVECTION STARTS OVER WI AND THE WESTERN
U.P.. BETTER CHANCES EXIST FOR CONVECTION REMAINING MORE
SCATTERED BUT ALIGNED IN THE FORM OF A LINE WITH DAMAGING WINDS
AND LARGE HAIL REMAINING AN ISOLATED THREAT WITH A HANDFUL OF
STORMS.
LONG TERM /TUESDAY NIGHT THROUGH MONDAY/
ISSUED AT 320 PM EDT MON APR 28 2025
PATTERN SYNOPSIS AND FORECAST:
HIGH PRESSURE BUILDS IN BRIEFLY ON WEDNESDAY WITH SEASONABLE
TEMPERATURES AND LIGHTER WINDS. NEXT CHANCE FOR PRECIPITATION WILL
BE THURSDAY INTO PORTIONS OF FRIDAY DUE TO A LOW PRESSURE SYSTEM
TRACKING UP FROM THE S PLAINS-MS VALLEY VICINITY INTO SOUTHERN
PORTIONS OF MI. THERE ARE STILL DISCREPANCIES ON THE EXACT TRACK OF
THIS LOW PRESSURE SYSTEM, FOR INSTANCE CMC SHOVES IT A LITTLE
FARTHER EAST, ALONG WITH SUBSEQUENT GEPS ENS, BUT THE GFS/GEFS &
ECMWF/EPS KEEP THE LOW/PRECIP SHIELD FARTHER NW. SOMETHING TO FINE
TUNE IN THE COMING DAYS BUT THE BEST POTENTIAL FOR WETTING RAINS MAY
RESIDE ACROSS THE SOUTHEASTERN HALF OF NORTHERN MI. MUCH COOLER
FRIDAY INTO THE FIRST HALF OF THIS WEEKEND AFTER THIS SYSTEM, AND
ADDITIONAL UPPER LEVEL SYSTEM SWINGS ON THROUGH (SHOWERS WILL LINGER
ON FRIDAY DUE TO AN UPPER LEVEL SYSTEM ADDING LIFT). CANNOT
COMPLETELY RULE OUT A FEW SNOWFLAKES IF THE COLD AIR TIMES PERFECTLY
WITH SOME LINGERING MOISTURE. DRY THIS WEEKEND, WITH WARMING
TEMPERATURES SUNDAY INTO EARLY NEXT WEEK AS HEIGHTS BUILD ALOFT. A
WARM AND DRY PERIOD LOOKS INCREASINGLY LIKELY IN THE EXTENDED (~MAY
5 AND BEYOND) AS AN OMEGA/REX BLOCK, OR SOME COMBINATION OF THE TWO,
FORMS OVER THE CONUS WITH THE HIGH PRESSURE CENTERED NEAR NORTHERN
MI.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1145 PM EDT MON APR 28 2025
STILL EXPECTING UPSTREAM SHOWERS AND THUNDERSTORMS TO MOVE WEST
TO EAST ACROSS THE AREA EARLY THIS MORNING. UNCERTAINTY
REMAINS, BOTH WITH REGARDS TO OVERALL COVERAGE AND INTENSITY OF
THESE STORMS. IF STORMS REMAIN ORGANIZED, A FEW MAY CONTAIN VERY
GUSTY WINDS AND SOME HAIL. SHOWER THREAT CONTINUES INTO TODAY,
WITH AGAIN PERHAPS A FEW EMBEDDED THUNDERSTORMS. GRADUAL
IMPROVEMENT EXPECTED FROM WEST TO EAST THIS AFTERNOON. STRONG
LOW LEVEL JET WILL CONTINUE TO PRODUCE WIDESPREAD LOW LEVEL
WIND SHEAR EARLY THIS MORNING, THIS DESPITE MAINTENANCE OF
GUSTY SOUTH TO SOUTHWEST SURFACE WINDS. WIND SHEAR ENDS LATER
THIS MORNING, WITH SURFACE WINDS BECOME NORTHWEST AND REMAINING
GUSTY AS WE HEAD THROUGH THE DAY. SKIES CLEAR AND WINDS DECREASE
THIS EVENING.
APX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LHZ345>349.
GALE WARNING UNTIL 11 AM EDT TUESDAY FOR LMZ323-341-342-
344>346.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LSZ321-322.
UPDATE...MSB
SHORT TERM...ELD
LONG TERM...JLD
AVIATION...MSB
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