613
FXUS63 KDLH 090549
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
1249 AM CDT TUE SEP 9 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 /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1249 AM CDT TUE SEP 9 2025
MOST WEATHER MODELS CONTINUE TO POORLY HANDLE THE ONGOING
CONVECTION, SO HAVE BACKED OFF ON PREVAILING THUNDERSTORM
MENTION AT MOST TERMINALS OVERNIGHT AND RELIED HEAVIER ON VCTS
AND PROB30 GROUPS. WITH THAT SAID, HIB/DLH HAVE THE BEST
POTENTIAL TO SEE ONGOING SHOWER/STORM POTENTIAL OVERNIGHT GIVEN
PROXIMITY TO A STATIONARY FRONT. LOOK FOR GENERALLY MVFR TO VFR
VISIBILITIES FOR THEM IN SHOWERS, WITH OCCASIONAL DIPS TO IFR
VISIBILITY FOR ANY STORMS THAT MOVE OVERHEAD. SHOWERS AND STORMS
ARE GENERALLY SLOW MOVING, BUT THE FRONT SHOULD START SLOWLY
SAGGING SOUTH TODAY, PUSHING FARTHER SOUTHEAST INTO NORTHWEST
WISCONSIN FOR MUCH OF TODAY. OUTSIDE OF STORMS, EXPECT CURRENT
VFR TO MVFR CEILINGS TO PLUMMET TO IFR TO LIFR TOWARDS EARLY
MORNING FOR NORTHEAST MINNESOTA TERMINALS TOWARDS EARLY MORNING,
LINGERING TOWARDS MIDDAY. THIS AREA OF IFR CEILINGS SHOULD
SHIFT INTO NORTHWEST WISCONSIN LATER IN THE MORNING INTO
AFTERNOON/EVENING AS THE FRONT AND PRECIPITATION SLIDES
SOUTHEAST, WITH CONDITIONS GRADUALLY RETURNING TO MVFR/VFR FOR
MOST NORTHEAST MINNESOTA TERMINALS MID TO LATE TODAY. LIFR TO
VLIFR CONDITIONS IN DENSE FOG PERSIST AT INL INTO EARLY THIS
MORNING, BEFORE GRADUALLY IMPROVING TOWARDS MID TO LATE MORNING. LLWS
PERSISTS TOWARDS 08Z FOR DLH AND 10Z FOR HYR PRIOR TO THE LOW-
LEVEL JET WEAKENING.
LOOK FOR MORE WIDESPREAD FOG TO DENSE FOG AND LOW STRATUS
POTENTIAL TOWARDS OR JUST AFTER THE VERY END OF THE CURRENT TAF
PERIOD TUESDAY NIGHT GIVEN LIGHT WINDS AND LINGERING LOW-LEVEL
MOISTURE.
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 UNTIL 10 AM CDT THIS MORNING FOR LSZ121-
148-150.
DISCUSSION...BJH
AVIATION...ROTHSTEIN
MARINE...BJH
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