507
FXUS63 KDLH 201121
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
621 AM CDT WED AUG 20 2025
KEY MESSAGES
- PATCHY DENSE FOG THIS MORNING.
- SUNNY AND WARM WEATHER TODAY AND THURSDAY
- A SLOW-MOVING COLD FRONT CROSSES LATE THURSDAY THROUGH FRIDAY
AND WILL BRING A CHANCE FOR SHOWERS AND STORMS. A FEW STORMS
MAY BE STRONG TO SEVERE.
- BEHIND THE FRONT EXPECT MUCH COOLER TEMPERATURES FOR THE
WEEKEND WITH HIGHS IN THE 60S AND LOWS IN THE 40S.
DISCUSSION
ISSUED AT 257 AM CDT WED AUG 20 2025
PATCHY DENSE FOG IS THE MAIN CONCERN EARLY THIS MORNING, BUT IT WILL
GRADUALLY BURN OFF, LEADING TO A SUNNY AND PLEASANT WEDNESDAY. IT
IS QUITE TRANSIENT AND THEREFORE HAVE ONLY COVERED ANY PROBLEM
AREAS WITH SPS'S WHICH SEEMS LIKE A GOOD CALL GIVEN THE OSCILLATORY
NATURE OF THE PHENOMENA.
THE QUIET WEATHER WILL BE SHORT-LIVED, AS WARMER AIR BUILDS IN FOR
THURSDAY WITH HIGHS IN THE LOW TO MID 80S. A SLOW-MOVING COLD FRONT
APPROACHING LATE IN THE DAY WILL BRING THE POTENTIAL FOR SHOWERS
AND THUNDERSTORMS. WHILE A FEW STORMS COULD BECOME STRONG TO SEVERE
WITH HAIL AND WIND, THE OVERALL SEVERE THREAT IS MARGINAL AS THE
STORMS ARRIVE IN KOOCHICHING COUNTY AROUND SUNSET LOSING DIURNAL
HEATING. INITIALLY SHEAR AND CAPE ARE SUFFICIENT FOR STRONG TO
SEVERE STORMS, BUT EHI VALUES QUICKLY FADE AFTER SUNSET REDUCING
THE THREAT. THERE MAY BE A LITTLE LLJ ENHANCEMENT OVERNIGHT TO
COMPENSATE FOR THE LACK OF INSTABILITY. THE STORM PREDICTION CENTER
HAS MAINTAINED A MARGINAL RISK (LEVEL 1 OF 5) FOR PORTIONS OF
OUR AREA TO ACCOUNT FOR THIS CONDITIONAL THREAT FOR BOTH
THURSDAY AND FRIDAY. ONE THING TO KEEP AN EYE ON IS THE
POTENTIAL FOR HEAVY RAINFALL WITH PWATS NEAR 2 INCHES AND A SLOW
MOVING COLD FRONT WITH UPPER LEVEL FLOW PARALLEL TO THE FRONT.
ON A POSITIVE NOTE, THE MPCA SAYS THAT THE CANADIAN WILDFIRES
HAVE DIMINISHED IN INTENSITY DUE TO RECENT RAINFALL, AND
THEREFORE THERE SHOULD BE SIGNIFICANTLY LESS SMOKE AND BETTER
AIR QUALITY FOLLOWING THE THURSDAY/FRIDAY COLD FRONT RELATIVE TO
THE REST OF THIS SUMMERS COLD FRONTS.
A SIGNIFICANT PATTERN CHANGE ARRIVES FOR THE WEEKEND AS THE FRONT
USHERS IN A MUCH COOLER, FALL-LIKE AIR MASS WITH BREEZY NORTHWEST
WINDS. HIGHS WILL DROP INTO THE 60S AND LOW 70S. AN UPPER-LEVEL
LOW WILL KEEP A CHANCE FOR SCATTERED SHOWERS IN THE FORECAST FROM
FRIDAY NIGHT THROUGH SUNDAY. SOME LAKE-ENHANCED RAIN SHOWERS WILL
ALSO BE POSSIBLE, ESPECIALLY ALONG THE SOUTH SHORE, AS THE COLD
AIR PASSES OVER THE RELATIVELY WARM WATERS OF LAKE SUPERIOR. THIS
COOLER PATTERN WILL PERSIST INTO MONDAY BEFORE TEMPERATURES BEGIN
TO MODERATE BY TUESDAY.
AVIATION /12Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 613 AM CDT WED AUG 20 2025
MVFR STRATUS IS PERSISTING WITH SOME BREAKS AND SHOULD LAST
THROUGH MID/LATE MORNING WITH LOCALIZED LIFR FOG. DAYTIME
HEATING SHOULD EVENTUALLY SCOUR OUT THE STRATUS. MODELS SHOW
ANOTHER LIGHT SIGNAL FOR FOG TONIGHT ACROSS THE REGION THOUGH
PROBABLY EVEN LESS COVERAGE AS WE GET FURTHER REMOVED FROM
PRECIPITATION. LIGHT WINDS.
MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/
ISSUED AT 257 AM CDT WED AUG 20 2025
LIGHT AND VARIABLE WINDS THROUGH TONIGHT WITH HIGH PRESSURE
SETTLING IN. WINDS WILL TREND A BIT BREEZIER THURSDAY NIGHT INTO
FRIDAY WITH SOUTHWEST WINDS BECOMING NORTHWEST AS A COLD FRONT
PASSES THROUGH. SCATTERED NON-SEVERE SHOWERS AND STORMS WILL BE
POSSIBLE THURSDAY NIGHT. WIND GUSTS ARE EXPECTED TO HOVER
AROUND 15 KT THURSDAY NIGHT INTO FRIDAY. NW WIND GUSTS TO 20-25
KT ARE POSSIBLE GOING INTO SATURDAY FOR MOST NEARSHORE ZONES AS
MORE COOLER AIR MOVES IN FROM THE NORTH.
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...NONE.
DISCUSSION...WOLFE
AVIATION...WOLFE
MARINE...WOLFE
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