118
FXUS63 KAPX 250728
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
328 AM EDT TUE AUG 25 2026
KEY MESSAGES
- STRONG STORMS AND HEAVY RAIN POSSIBLE ON WEDNESDAY
DISCUSSION
ISSUED AT 326 AM EDT TUE AUG 25 2026
PATTERN SYNOPSIS/FORECAST:
569DM 500MB LOW CHURNING ACROSS SOUTHERN CANADA ATTM, SLOWLY LOSING
A BIT OF STEAM AS IT PASSES OVERTOP THE BROAD SOUTHERN STREAM 598DM
RIDGE CENTERED OVER NEW MEXICO. ADDITIONAL PERTURBATIONS RIDING UP
INTO THE PACNW OFF THE PACIFIC, ALBEIT MUCH LESS NOTABLE THAN THE
ONE OVER SOUTHERN CANADA. SHORTWAVE RIDGE AXIS BUILDING OVER THE
UPPER GREAT LAKES IN THE WAKE OF 563DM UPPER LOW OVER QUEBEC, THOUGH
A FEW PV MAXIMA CONTINUE TO SWIRL BACK TOWARD MI IN BEHIND THIS AS
OF 3Z AS NWLY 80KT UPPER JET DEPARTS. QUIET AND BRIEFLY DRYING HERE
IN THE NORTHWOODS WITH HIGH PRESSURE RETURNING...BETWEEN PLUME OF
MOISTURE ASSOCIATED WITH THE DEPARTING LOW FINALLY PULLING OUT TO
THE EAST...AND NEXT PLUME OF MOISTURE, INSTABILITY, AND ATTENDANT
CONVECTION STRETCHING FROM THE CENTRAL PLAINS UP AROUND THE
AFORMENTIONED CANADIAN UPPER LOW..ALONG A COLD FRONT STRETCHING FROM
OCCLUDED LOW OVER MANITOBA DOWN INTO THE PANHANDLE OF NEBRASKA, WITH
A WARM FRONT OVER MN. STATIONARY BOUNDARY STRETCHES FROM WESTERN KS
TO THE CAROLINAS AND UP INTO ME; SOME DEEPER MOISTURE AND CONVECTION
OVER THE LOWER MS VALLEY AND GULF COAST WITH THIS. A LITTLE WARMER
YESTERDAY WITH INCREASING SUNSHINE AND WARM ADVECTION ALOFT; 850MB
TEMPS RISE INTO THE TEENS AGAIN JUST TO OUR WEST.
RIDGE AXIS WILL MOVE THROUGH TODAY...AS UPSTREAM PV MAXIMUM DIGS
INTO THE UPPER MIDWEST TONIGHT INTO WEDNESDAY, DRAGGING A SURFACE
FRONT THROUGH THE AREA, GIVING US A SHOT AT SOME BEEFIER SHOWERS AND
STORMS FOR MIDWEEK. THIS PV MAX WILL LIFT OUT TO OUR EAST THURSDAY
MORNING AS A LOBE OF ENERGY DIVES SSE FROM AN UPPER LOW OVER HUDSON
BAY, SIMILAR TO THIS PAST WEEKEND, THOUGH IT APPEARS THIS WILL BE
TRANSLATED SLIGHTLY EAST FROM THIS PAST WEEKEND'S PATTERN, SUCH THAT
IT MAY NOT BE QUITE AS COOL...BUT WE WILL PROBABLY REMAIN A LITTLE
MORE CLOUDY/UNSETTLED. PATTERN WILL BEGIN TO FLATTEN OUT ACROSS THE
NORTHERN CONUS AS AN UPPER LOW TREKS THROUGH WESTERN CANADA...WITH A
SHALLOW RIDGE AXIS UPSTREAM FROM US FOR THE END OF THE WEEK,
SIGNALING A POTENTIAL PATTERN FOR ACTIVITY TO RIDE THE RIDGE TOWARD
THE GREAT LAKES FOR THE SECOND HALF OF THE WEEK. QUITE A BIT OF
UNCERTAINTY IN THE PATTERN BEYOND THIS, WITH GUIDANCE STRUGGLING TO
DETERMINE HOW THE PATTERN ACROSS CANADA WILL EVOLVE GOING INTO NEXT
WEEKEND, THOUGH IT IS POSSIBLE WE MAY BE UNDER THE INFLUENCE OF WARM
ADVECTION AND COULD STAY SOMEWHAT UNSETTLED.
FORECAST DETAILS...
HEAVY RAIN POTENTIAL WEDNESDAY...WARM ADVECTION TONIGHT INTO
WEDNESDAY MORNING SHOULD LEAD TO AN INCREASE IN SHOWER/STORM
COVERAGE ACROSS THE AREA, WITH THE POTENTIAL FOR BETTER CONVECTIVE
INSTABILITY ALONG THE COLD FRONT/DRY SLOT IN THE AFTERNOON AS CLOUDS
ATTEMPT TO CLEAR OUT A BIT...AND THEN MORE SHOWERS HANGING ON INTO
THE OVERNIGHT WITH ADDITIONAL MOISTURE BEHIND THE SYSTEM. PWATS JUMP
TOWARD 1.5IN AGAIN LATE TONIGHT INTO THE EARLY MORNING HOURS, AND
HANG ON THROUGH THE AFTERNOON, SUGGESTING POTENTIAL FOR HEAVY RAIN,
PARTICULARLY IF STORMS ARE SLOW MOVING OR TRACK OVER THE SAME AREAS
MULTIPLE TIMES. THINK THE MOST LIKELY QPF BULLSEYE WILL BE THE EUP,
CLOSER TO THE SYNOPTIC FORCING ASSOCIATED WITH THE SHARP PV MAX
DIGGING INTO THE AREA...AND WHERE THERE MAY BE A POTENTIAL WARM
FRONT TO FOCUS SLOW-MOVING/TRAINING ACTIVITY. GUIDANCE SOUNDINGS IN
THIS AREA SUGGEST AN ENVIRONMENT MORE FAVORABLE FOR HEAVY RAINFALL
AS WELL, WITH SKINNIER CAPE PROFILES IN A MOIST ENVIRONMENT THROUGH
MUCH OF THE COLUMN. IF THE PV MAX DIGS A LITTLE FURTHER SOUTH INTO
THE AREA, THOUGH, THIS COULD PUT MORE OF THE AREA AT RISK FOR HEAVY
RAIN. ATTM, PROBABILISTIC GUIDANCE IS STARTING TO COME INTO A LITTLE
BETTER/STRONGER AGREEMENT (40-80 PERCENT) ON THE IDEA OF AT LEAST AN
INCH OF RAIN ACROSS THE EUP BY WEDNESDAY EVENING; WORTH NOTING THAT
THE CURRENT BULLSEYE OF 1IN+ QPF HASN'T MOVED MUCH AT ALL SINCE
YESTERDAY MORNING'S PACKAGE.
STRONG STORMS POSSIBLE WEDNESDAY...THINK WE WILL BE FIGHTING A
STRONG WARM NOSE AROUND 800MB (ISH) DURING THE DAY, BUT THERE ARE
SIGNALS FOR A COMBINATION OF DIURNAL HEATING AND MID-LEVEL COOLING
BY THE AFTERNOON TO TRY TO OVERCOME THIS AS THE FRONT CROSSES THE
REGION...ALLOWING ELEVATED INSTABILITY DURING THE MORNING HOURS TO
POTENTIALLY BECOME SURFACE BASED. GREATER INSTABILITY AND STEEPER
LAPSE RATES ALOFT SHOULD REMAIN TO OUR SOUTH WEDNESDAY...BUT WE ARE
STILL LOOKING AT 500-1500ISH JOULES OF INSTABILITY, WHETHER
ELEVATED OR NOT. ADDITIONALLY, A MID-LEVEL JET MAX ASSOCIATED
WITH THE PV MAXIMA SUGGESTS AN INCREASED SHOT AT DEEP-LAYER
SHEAR, AND WILL NEED TO KEEP AN EYE OUT FOR SOME STORM
ORGANIZATION AND SOME STRONGER STORMS. IT APPEARS THE BOUNDARY
MAY TRY TO DRAPE ACROSS THE REGION, TURNING A LITTLE MORE
ZONALLY-ORIENTED WITH TIME THROUGH THE DAY, WITH POTENTIAL FOR
SHEAR VECTORS AT LEAST MARGINALLY PERPENDICULAR TO THE BOUNDARY
AT TIMES, AND MAY NEED TO KEEP AN EYE OUT FOR SOME DISCRETE CELL
DEVELOPMENT THROUGH THE DAY.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1050 PM EDT MON AUG 24 2026
MOSTLY CLEAR TO PARTLY CLOUDY SKIES TODAY INTO THIS EVENING UNDER
SOME PASSING HIGHER LEVEL CLOUDS AND A FEW HIGH BASED CUMULUS.
CONCERN REMAINS THIS MORNING FOR THE POSSIBILITY FOR SOME
MIST/LIGHT FOG TO DEVELOP. CONFIDENCE CONTINUES TO REMAIN LOW
ON JUST HOW WIDESPREAD AND SIGNIFICANT THIS MIST/FOG WILL
BECOME. ANY FOG/MIST WILL QUICKLY MIX OUT AFTER SUNRISE. LIGHT
WINDS, WITH SOME LOCAL AFTERNOON LAKE BREEZE DEVELOPMENT
EXPECTED.
APX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...NONE.
DISCUSSION...FEF
AVIATION...MSB
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