697
FXUS63 KDLH 171755
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
1255 PM CDT SUN AUG 17 2025
KEY MESSAGES
- ANOTHER ROUND OF RAIN AND THUNDERSTORMS BEGINS THIS AFTERNOON
AND CONTINUES OVERNIGHT INTO MONDAY MORNING.
- HIGH PRESSURE AND DRIER CONDITIONS RETURN FROM TUESDAY INTO
THURSDAY MORNING WITH NEAR NORMAL TEMPERATURES.
DISCUSSION
ISSUED AT 344 AM CDT SUN AUG 17 2025
HIGH PRESSURE CENTERED OVER NORTHEAST ONTARIO AND A LOW PRESSURE
SHORTWAVE LIFTING THROUGH THE DAKOTAS WILL CREATE GUSTY EASTERLY
SYNOPTIC PRESSURE GRADIENT WINDS TODAY OVER THE REGION. A FEW
OF THOSE GUSTS OF 30 TO 40 MPH MAY REACH THE TWIN PORTS LATE
MORNING TO MID- EVENING TODAY. WITH THESE EAST-NORTHEAST GUSTY
WINDS TODAY, A HIGH RIP CURRENT RISK EXISTS FOR THE IMMEDIATE
LAKE SUPERIOR WATERS IN THE TWIN PORTS. A BEACH HAZARDS
STATEMENT IS IN EFFECT TODAY FOR THOSE BEACHES DUE TO A
DANGEROUS SWIMMING CONDITIONS IN THE TWIN PORTS OF CANAL PARK,
MINNESOTA POINT, AND WISCONSIN POINT. ONSHORE FLOW UNDER
SEASONABLE COOL AIRMASS AIDS IN KEEPING MAX TEMPERATURES TODAY
IN THE MID-60S TO LOW-70S, ESPECIALLY FOR NORTHEAST MINNESOTA
DOWNWIND OF LAKE SUPERIOR.
A NOTABLE DRY LAYER FROM 3000 TO 10000 FEET IS OBSERVED ON HIGH
RES FORECAST MODEL SOUNDINGS THROUGH MID-AFTERNOON TODAY NORTH
OF A STALLED STATIONARY FRONT SLOWLY LIFTING NORTHWARD INTO
CENTRAL MINNESOTA. A FEW WIDELY SCATTERED THUNDERSTORMS AND RAIN
SHOWERS CANNOT BE ENTIRELY RULED OUT IN EARLY AFTERNOON TODAY,
BUT OUTSIDE OF THE BRAINERD LAKES REGION MINIMAL RAINFALL IS
EXPECTED. AS BETTER MESOSCALE FRONTAL FORCING ENTERS NORTH-
CENTRAL MINNESOTA LATE AFTERNOON TODAY, EXPECT AN UPTICK IN
STORM CHANCES FROM WEST TO EAST THIS EVENING. ANOMALOUS
PRECIPITABLE WATER VALUES OF 1.4 TO 1.8 INCHES ARE LIKELY IN A
LIMITED-DURATION WARM SECTOR ALOFT THIS EVENING AND OVERNIGHT.
THESE CONDITIONS UNDER A DISORGANIZED AND WEAKLY SHEARED
ENVIRONMENT AND INSTABILITY PROGGED AT LESS THAN 500 J/KG KEEP
THE MAIN THUNDERSTORM HAZARDS TO HEAVY RAINFALL OF 1-2 INCHES
AND GUSTY WINDS TO 40 MPH INTO THIS EVENING AND TONIGHT. AS THE
HEAVIER RAINFALL LINGERS MONDAY MORNING IN NORTH-CENTRAL
WISCONSIN AND THE TIP OF THE ARROWHEAD, CHANCES FOR ADDITIONAL
RAINFALL DECREASE FROM WEST TO EAST ELSEWHERE MONDAY MORNING TO
MID-DAY.
EVEN AS THOSE GUSTY EASTERLY WINDS DECREASE TONIGHT FROM SOUTH
TO NORTH NEAR LAKE SUPERIOR, EXPECT LINGERING LARGE SWELL MONDAY
FROM 2 TO 4 FEET AND FUNNELED EASTERLY WINDS GUSTING 15-20 MPH.
ANOTHER DAY OF A HIGH RIP CURRENT RISK IS POSSIBLE AGAIN MONDAY
SO ANOTHER BEACH HAZARDS STATEMENT MAY AGAIN BY NEEDED FOR THE
TWIN PORTS BEACHES TOMORROW.
A VERY DRY AIRMASS SETS UP FOR MONDAY NIGHT THROUGH THURSDAY
AFTERNOON TO CREATE MOSTLY SUNNY SKIES, NEAR TO SLIGHTLY BELOW
NORMAL SEASONABLE TEMPERATURES AND DRY WEATHER.
THE NEXT CANADIAN PRAIRIES SHORTWAVE TROUGH SLIDES THROUGH THE
BORDERLANDS THURSDAY TO CREATE THE NEXT ROUND OF THUNDERSTORM
CHANCES. A DECENT MOISTURE TAP AND INSTABILITY POOL ASSOCIATED
WITH A BAND OF FRONTAL FORCING IS PROGGED WITH THIS THURSDAY
SHORTWAVE. SO GIVEN THE CURRENT SYNOPTIC PATTERN A CHANCE OF
STRONG THUNDERSTORMS WILL HAVE TO BE MONITORED FOR THURSDAY
LATE AFTERNOON TO EVENING IN THE NORTHLAND.
POST-FRONTRAL WEST TO NORTHWESTERLY FLOW ALOFT SETS UP FRIDAY
INTO NEXT WEEKEND UNDER SEASONABLE TEMPERATURES.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 1254 PM CDT SUN AUG 17 2025
CURRENT VFR CONDITIONS TO BE SLOWLY OVERCOME BY MVFR CEILINGS AS
WAVES OF SHOWERS AND THUNDERSTORMS SPREAD IN FROM THE SOUTHWEST
LATER TODAY AND THIS EVENING. ALL TERMINALS TO EVENTUALLY
DETERIORATE THIS EVENING TO PREDOMINANTLY MVFR CONDITIONS, THEN
TO IFR CEILINGS AND MVFR VISIBILITIES AFTER 05Z/MIDNIGHT AS
WIDESPREAD RAIN WITH EMBEDDED THUNDER SPREADS IN. PERIODS OF
LIFR CEILINGS ARE ALSO POSSIBLE, BUT HAVE ONLY INCLUDED THAT FOR
KBRD AND KINL FOR NOW. EXPECT A GRADUAL IMPROVEMENT BEGINNING
LATE MORNING/EARLY AFTERNOON, BUT CONFIDENCE IS LOW AND HAVE NOT
INCLUDED FOR NOW.
MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/
ISSUED AT 1254 PM CDT SUN AUG 17 2025
NORTHEAST WINDS ARE STRENGTHENING SO FAR TODAY, WITH GUSTS SO
FAR STAYING UNDER 33 KTS, BUT I DO NOT EXPECT THAT TO LAST LONG,
AND WINDS SHOULD BE STRONGEST BETWEEN THE 2PM TO 8PM. THIS IS
BEING CAUSED BY A TIGHTENING PRESSURE GRADIENT OVER WESTERN LAKE
SUPERIOR BETWEEN HIGH PRESSURE OVER ONTARIO AND INCOMING LOW
PRESSURE PASSING THROUGH SOUTH DAKOTA AND SOUTHERN MINNESOTA
LATER TODAY. SUSTAINED WIND SPEEDS AROUND 20 KNOTS WITH GALE
FORCE GUSTS, MAINLY FOR THE SOUTHWEST TIP OF THE LAKE. THESE
WINDS WILL BUILD LARGE WAVE HEIGHTS, WHICH IS UNUSUAL FOR THIS
TIME OF YEAR, ACROSS ALL WATERS RANGING FROM 3 TO 6 FEET. EXPECT
DANGEROUS CONDITIONS FOR SMALL CRAFT AND VESSELS THROUGH TODAY
WITH ADVISORIES IN EFFECT. THE GALE WARNING HAS BEEN EXPANDED TO
THE DULUTH TO PORT WING ZONE, FOR NOW THROUGH 10 PM. WHILE THE
CURRENT ADVISORIES EXPIRE THIS EVENING CURRENTLY, AN EXTENSION
IN TIME CAN BE EXPECTED FOR MOST ZONES IS LIKELY INTO MONDAY AS
ELEVATED SWELL LINGERS. THE NEXT ROUND OF THUNDERSTORMS BUILDS
WEST TO EAST THIS EVENING AND GENERAL THUNDERSTORM HAZARDS ARE
LIKELY TONIGHT INTO MONDAY MID- DAY.
FOR THE OPEN WATER DISCUSSION, REFER TO THE NWS MARQUETTE AREA
FORECAST DISCUSSION AT WEATHER.GOV/MQT.
DLH WATCHES/WARNINGS/ADVISORIES
MN...BEACH HAZARDS STATEMENT UNTIL 10 PM CDT THIS EVENING FOR
MNZ037.
WI...BEACH HAZARDS STATEMENT UNTIL 10 PM CDT THIS EVENING FOR
WIZ001.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LSZ121-
140-141-146>148-150.
GALE WARNING UNTIL 10 PM CDT THIS EVENING FOR LSZ142>145.
DISCUSSION...NLY
AVIATION...LE
MARINE...LE
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