056
FXUS63 KDLH 082031
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
331 PM CDT MON SEP 8 2025
KEY MESSAGES
- SHOWERS AND THUNDERSTORMS EXPECTED TONIGHT INTO TUESDAY. AN
ISOLATED STRONG TO SEVERE STORM WILL BE POSSIBLE MAINLY IN THE
BRAINERD LAKES AREA WITH LARGE HAIL THE PRIMARY THREAT.
- RAINFALL MAY BE HEAVY AT TIMES AND MAY LEAD TO LOCALIZED FLASH
FLOODING.
- A DRY AND WARMING PATTERN TAKES OVER FOR THE REMAINDER OF THE
WEEK WITH RAIN CHANCES RETURNING HEADING INTO THE WEEKEND.
DISCUSSION
ISSUED AT 331 PM CDT MON SEP 8 2025
HIGH PRESSURE WAS IN CONTROL ACROSS THE EASTERN GREAT LAKES THIS
AFTERNOON AND EXTENDED TO THE SOUTHWEST INTO THE SOUTHERN
PLAINS. AN ELONGATED AREA OF LOW PRESSURE WAS IN PLACE OVER THE
NORTHERN PLAINS WITH A WARM FRONT EXTENDING FROM SOUTHERN NORTH
DAKOTA INTO CENTRAL MINNESOTA AND FAR WESTERN WISCONSIN. A
CLUSTER OF ELEVATED THUNDERSTORMS WAS OBSERVED ON RADAR ACROSS
PORTIONS OF KOOCHICHING, ITASCA AND ST. LOUIS COUNTIES. THIS
CLUSTER WAS LOCATED AT THE HEAD OF AN MUCAPE GRADIENT STRETCHING
FROM THE DAKOTAS INTO WESTERN AND NORTH-CENTRAL MINNESOTA. SPC
MESOANALYSIS SHOWS UP TO AROUND 500 J/KG OF MUCAPE WHERE THE
STORMS ARE WITH AROUND 30 KNOTS OF EFFECTIVE SHEAR. STORMS
HAVEN'T SHOWN MUCH ORGANIZATION THUS FAR BUT SLIGHTLY BETTER
SHEAR DOES ARRIVE AS THE EVENING PROGRESSES AS A LOW-LEVEL JET
SPREAD ACROSS THE REGION BEHIND THE ADVANCING WARM FRONT.
FORECAST SOUNDINGS CONTINUE TO SHOW A CAPPING INVERSION
PERSISTING INTO TONIGHT, WHICH SHOULD LIMIT ANY SURFACE BASED
STORMS AND KEEP THEM ELEVATED. THIS WILL LEAD TO A MARGINAL
LARGE HAIL THREAT WITH MARGINAL MID-LEVEL LAPSE RATES AND, WHILE
CAPE PROFILES ARE OVERALL SKINNY LEADING TO MORE OF A HEAVY
RAIN THREAT, THE THICKEST PART OF THE PROFILES IS THROUGH THE
HGZ. SHOULD A STORM BECOME SURFACE BASED, THERE IS A NON-ZERO
TORNADO THREAT WITH FAIRLY STRONG SPEED AND DIRECTIONAL SHEAR IN
THE 0-1KM LAYER AND SRH OVER 200 M2/S2. MULTIPLE ROUNDS OF
SHOWERS AND STORMS ARE EXPECTED FOR TONIGHT INTO TUESDAY AS THE
WARM FRONT STALLS OUT OVER THE REGION AND THEN STARTS TO SLOWLY
MOVE SOUTHEAST AS A COLD FRONT TUESDAY. THE BEST CHANCE FOR ANY
STRONG STORMS THIS EVENING WILL BE IN THE BRAINERD LAKES AREA
AND SOUTH/WEST OF A CASS LAKE TO GRAND RAPIDS TO HIBBING TO
CLOQUET TO HINCKLEY LINE. GIVEN THE POTENTIAL FOR MULTIPLE
ROUNDS OF STORMS AND CONTINUED MOISTURE FEEDING INTO THE
REGION, SOME ISOLATED FLASH FLOODING WILL BE POSSIBLE. THE
HEAVIEST RAINFALL AMOUNTS LOOK TO STRETCH FROM THE IRON RANGE
INTO THE ARROWHEAD WHERE 1 TO 2 INCHES PLUS OF RAINFALL WILL BE
POSSIBLE. THE AREA OF HEAVIER RAINFALL POTENTIAL THEN SHIFTS
INTO NORTHWEST WISCONSIN FOR TUESDAY.
HIGH PRESSURE WILL BUILD IN FOR MID-WEEK WITH UPPER LEVEL
RIDGING PUSHING IN FROM THE WEST AS WELL. THIS WILL LEAD TO DRY
CONDITIONS WITH TEMPERATURES WARMING INTO THE 70S WITH EVEN SOME
LOW 80S BY FRIDAY. RAINFALL CHANCES THEN RETURN FOR FRIDAY INTO
THE WEEKEND WITH A CUTOFF LOW DROPPING SOUTHEAST FROM ST. JAMES
BAY INTO SOUTHWESTERN ONTARIO ALONG WITH A BAROCLINIC ZONE
SETTING UP FROM THE NORTHERN HIGH PLAINS INTO THE GREAT LAKES
FOR THE WEEKEND INTO EARLY NEXT WEEK. TEMPERATURES WILL THEN
COOL BACK INTO THE 60S AND LOWER 70S TO START THE NEW WORK WEEK.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 109 PM CDT MON SEP 8 2025
CLOUD COVER WILL INCREASE THIS AFTERNOON AS A WARM FRONT LIFTS
INTO THE REGION. CEILINGS WILL LOWER TO MVFR TONIGHT WITH SOME
IFR CEILINGS POSSIBLE AT DLH, INL, HIB, AND BRD. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP LATER THIS AFTERNOON AND
ESPECIALLY TONIGHT. THIS ACTIVITY WILL REMAIN SOUTH OF THE WARM
FRONT AND SHOULD NOT AFFECT INL. CONFIDENCE ON THE TIMING AND
LOCATION OF THIS ACTIVITY REMAINS LOWER. FOG IS ALSO EXPECTED TO
DEVELOP IN THE HOURS AROUND DAYBREAK. THERE IS THE POTENTIAL FOR
IFR OR LOWER VISIBILITIES, ESPECIALLY AT HIB AND INL. WINDS
HAVE BEEN SLOW TO INCREASE AND HAVE LOWERED MOST TERMINALS WITH
THIS UPDATE. LLWS IS STILL ON TRACK TO AFFECT DLH, HIB, AND HYR
LATER THIS AFTERNOON AND INTO TONIGHT.
MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/
ISSUED AT 331 PM CDT MON SEP 8 2025
ROUNDS OF SHOWERS AND THUNDERSTORMS WILL BE SEEN THIS AFTERNOON
INTO TUESDAY WITH ACTIVITY BECOMING MORE FOCUSED ALONG THE SOUTH
SHORE AS THE DAY PROGRESSES TUESDAY. LIGHTNING AND SMALL HAIL
WILL BE THE PRIMARY THREATS WITH ANY STORMS. WINDS WILL BE
SOUTHERLY TO SOUTHWESTERLY WITH GUSTS TO 20 TO 25 KNOTS TONIGHT
INTO TUESDAY FROM THE OUTER APOSTLES TO SAXON HARBOR. SMALL
CRAFT ADVISORIES HAVE BEEN ISSUED THROUGH LATE TUESDAY MORNING
FOR THIS THREAT. WINDS REMAIN SOUTHWESTERLY FOR TUESDAY AND
DECREASE TO 10 TO 20 KNOTS DURING THE AFTERNOON BEFORE FURTHER
WEAKENING TUESDAY NIGHT AND BECOMING NORTHEASTERLY AT 5 TO 15
KNOTS FOR WEDNESDAY.
FOR THE OPEN WATER DISCUSSION, REFER TO THE NWS MARQUETTE AREA
FORECAST DISCUSSION AT WEATHER.GOV/MQT.
DLH WATCHES/WARNINGS/ADVISORIES
MN...NONE.
WI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 10 AM CDT
TUESDAY FOR LSZ121-148-150.
DISCUSSION...BJH
AVIATION...BJH
MARINE...BJH
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