653
FXUS63 KDLH 190922
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
422 AM CDT THU MAR 19 2026
KEY MESSAGES
- WIDELY ISOLATED PATCHES OF DENSE FOG ARE EXPECTED THIS MORNING
AND SHOULD DISSIPATE BY MID-MORNING.
- CLOUDS AND POSSIBLE FOG DEVELOPMENT EARLY THIS MORNING MAY
LIMIT HEATING TODAY. TEMPERATURES WILL CLIMB ABOVE FREEZING.
AREAS WHERE SKIES ARE PARTLY CLOUDY OR CLEAR DURING PEAK
HEATING WILL REACH THE UPPER 40S TO LOW 50S.
- A WEAK CLIPPER WILL MOVE ACROSS THE CANADIAN PRAIRIES AND
NORTHERN MINNESOTA TONIGHT. EXPECT A MIX OF RAIN AND FREEZING
RAIN STARTING LATE THIS MORNING AND ENDING TONIGHT OVER NORTH-
CENTRAL MINNESOTA INTO THE ARROWHEAD. ICE POTENTIAL IS
GREATEST IN COOK COUNTY.
- WIDESPREAD FOG IS EXPECTED TONIGHT DUE TO SNOW MELT AND
SOUTHERLY WINDS. FOG WILL BE LOCALLY DENSE.
- A BETTER ORGANIZED CLIPPER WILL MOVE THROUGH THE REGION OVER
THE WEEKEND. MIXED PRECIPITATION IS FORECAST.
DISCUSSION
ISSUED AT 422 AM CDT THU MAR 19 2026
A STRIPE OF LOW STRATUS STRETCHED FROM NEAR GPZ TO UPPER
MICHIGAN AT 3 AM AND WILL CONTINUE TO SLOWLY PROGRESS SOUTHWARD
THIS MORNING. THERE IS A 10% CHANCE OF VERY LIGHT FREEZING
DRIZZLE WITH THAT CLOUD DECK. THE OTHER CONCERN EARLY THIS
MORNING IS THE POTENTIAL DEVELOPMENT OF FOG. LOW-LEVEL MOISTURE
RECEIVED A SMALL BOOST FROM SNOWMELT AND SOUTHERLY WARM AIR
ADVECTION YESTERDAY AFTERNOON. CLEAR TO MAINLY CLEAR SKIES OVER
MUCH OF NORTHEAST MINNESOTA ALONG WITH RELATIVELY LIGHT WINDS
WILL ALLOW FOR RADIATIONAL COOLING. THE MAIN QUESTION IS WHETHER
THE COOLING WILL BE RAPID ENOUGH TO GENERATE DENSE FOG OR IF
DIRECT DEPOSITION OF ICE ONTO SURFACES WILL LIMIT FOG FORMATION.
INL VISIBILITY WAS AT 1/4 MILE FOR A FEW MINUTES IN THE LAST
HOUR AND IS BACK TO 5 MILES NOW. REDUCED VISIBILITY IS EXPECTED
TO BECOME MORE WIDESPREAD BEFORE SUNRISE, BUT WIDESPREAD DENSE
FOG APPEARS UNLIKELY.
A CLIPPER LOCATED OVER SOUTHERN ALBERTA EARLY THIS MORNING WILL
PROPAGATE EAST-SOUTHEASTWARD ACROSS THE CANADIAN PRAIRIES AND
INTO NORTHEAST MINNESOTA BY EARLY FRIDAY MORNING. THE REGIONAL
RADAR MOSAIC REVEALS A BAND OF LIGHT PRECIPITATION OVER SOUTHERN
MANITOBA WHICH APPEARS SHOWERY IN NATURE. HIGH-RES MODELS ARE
BEGINNING TO CAPTURE THAT PRECIPITATION. THE 00Z HI-RES FV3 AND
07Z RAP SEEM TO HAVE THE BEST HANDLE AT THE MOMENT. THOSE MODELS
BRING LIGHT PRECIPITATION INTO THE INTERNATIONAL FALLS VICINITY
LATE THIS MORNING AND INTO THE EASTERN ARROWHEAD THROUGH EARLY
AFTERNOON. TEMPERATURES ARE EXPECTED TO WARM ABOVE FREEZING
RESULTING IN RAIN AS THE MAIN WEATHER TYPE. THERE IS ABOUT A 10%
CHANCE OF FREEZING RAIN EVEN WITH AIR TEMPERATURES ABOVE
FREEZING AS PRECIP BEGINS.
ELEVATED INSTABILITY AND LIFTED INDICES NEAR ZERO THIS
AFTERNOON INTO THIS EVENING OVER THE BORDERLANDS SUGGESTS A
POTENTIAL FOR A FEW RUMBLES OF THUNDER. WARM AIR ALOFT PERSISTS
AS THE SECOND WING OF PRECIPITATION ADVANCES INTO THE ARROWHEAD
THIS EVENING INTO THE OVERNIGHT. SURFACE TEMPERATURES WILL DROP
BELOW FREEZING WHICH RAISES THE POTENTIAL FOR FREEZING RAIN
MAINLY OVER COOK COUNTY. THE CHANCE OF FREEZING RAIN IS ABOUT
40% AND THE PROBABILITY OF 5 HUNDREDTHS OF AN INCH OF ICING IS
AROUND 25%.
WITH ANOTHER WARM DAY ON TAP TODAY AND STRENGTHENING SOUTHERLY
WARM AIR ADVECTION AHEAD OF THE CLIPPER, THE STAGE WILL BE SET
FOR THE DEVELOPMENT OF WIDESPREAD FOG TONIGHT, SOME MAY BE
LOCALLY DENSE. IF THE FOG DEVELOPS, IT WILL BE DIFFICULT TO
SHAKE UNTIL THE WEEKEND. THE FORECAST HIGHS FOR FRIDAY WILL
HINGE ON WHETHER FOG AND LOW STRATUS DEVELOP TONIGHT. IF WE SEE
CLEARING, HIGHS WILL REACH THE UPPER 40S TO LOW 50S. OTHERWISE
WE CAN EXPECT UPPER 30S TO MIDDLE 40S. I TOOK THE WARMER PATH
FOR NOW.
ANOTHER PERIOD OF PRECIPITATION IS FORECAST SATURDAY AND
SUNDAY. THE PERSISTENT BAROCLINIC ZONE OVER THE NORTHLAND (AN
AREA IN THE ATMOSPHERE FEATURING A "NOTABLE" HORIZONTAL
TEMPERATURE GRADIENT) WILL FEED INTO A WEAK AREA OF LOW PRESSURE
TRAVERSING THE NORTHLAND SATURDAY. THAT SYSTEM WILL BE SIMILAR
TO TODAY'S CLIPPER. PRECIPITATION CHANCES WILL BE GREATEST NORTH
OF THE LOW TRACK. AS OF THIS MORNING THAT AREA INCLUDES MOST OF
NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN. WITH THE SYSTEM
RIDING RIGHT ALONG THE BAROCLINIC ZONE AND 0 *C ISOTHERMS
BISECTING THE NORTHLAND, A MIX OF RAIN, SNOW, AND POSSIBLY
FREEZING RAIN IS FORECAST. SLIGHT WOBBLES IN THE TRACK OF THE
LOW AND THE THERMAL GRADIENT ALOFT WILL INFLUENCE PRECIP TYPES.
AS OF THIS MORNING SNOW AMOUNTS ARE A DUSTING UP TO AN INCH. THE
LIKELIHOOD OF PRECIP BEING ALL SNOW IS LOW, AROUND 10-30%
DEPENDING ON LOCATION WITH THE GREATEST ODDS OF ALL SNOW IN COOK
COUNTY. FOR AREAS WHERE THERE IS A MIX...RAIN, SNOW, SLEET, AND
FREEZING RAIN ARE ALL POSSIBILITIES.
ANOTHER SHORTWAVE TROUGH WILL MOVE INTO THE REGION BY SATURDAY
NIGHT. ANOTHER ROUND OF WINTRY MIXED PRECIPITATION IS FAVORED.
THE SECOND ROUND OF PRECIPITATION IS SHAPING UP A BIT STRONGER
WITH ANOTHER DUSTING UP TO AN INCH OF SNOW POSSIBLE AND HIGHER
TOTALS ALONG THE NORTH SHORE. TOTAL SNOW BETWEEN BOTH SYSTEMS
WILL RANGE FROM A DUSTING UP TO AN INCH OR TWO FOR MOST
LOCATIONS AND UP TO 3 INCHES IN THE HIGH TERRAIN OF THE NORTH
SHORE. PRECIPITATION SHOULD TAPER OFF SUNDAY MORNING ALTHOUGH
THE GFS SOLUTION KEEPS LIGHT SNOW IN THE PICTURE THROUGH SUNDAY.
EARLY NEXT WEEK WILL SEE WARM TEMPERATURES DURING THE DAY
COOLING BELOW FREEZING AT NIGHT. THERE ARE A FEW ADDITIONAL
CHANCES OF PRECIPITATION MONDAY NIGHT AND THEN TUESDAY NIGHT
INTO WEDNESDAY. BOTH OF THOSE WOULD BE CLIPPER-TYPE SYSTEMS WITH
RELATIVELY LIGHT PRECIPITATION.
AVIATION /06Z TAFS THROUGH 06Z FRIDAY/
ISSUED AT 110 AM CDT THU MAR 19 2026
LOW FORECAST CONFIDENCE EARLY THIS MORNING. AN AREA OF MVFR
STRATUS WAS LOCATED OVER PORTIONS OF NORTHEAST MINNESOTA AND IS
FORECAST TO DRIFT SOUTHWARD OVER DLH AND HYR LATER THIS MORNING.
06Z HIB OBSERVATION FEATURED A CEILING OF 1000FT. IFR CEILINGS
ARE POSSIBLE FARTHER EAST. ELSEWHERE THE CLEAR SKIES MAY SUPPORT
FOG DEVELOPMENT THIS MORNING. RADIATIONAL COOLING MAY RESULT IN
IFR OR LIFR VISIBILITY. THE STRATUS OVER NORTHEAST MN APPEARS
TO BE EXPANDING SLOWLY WESTWARD AS THE CLOUDS DRIFT SOUTH. IF
MVFR/IFR OVERCAST SPREADS TO BRD, VISIBILITY WOULD BE MVFR OR
EVEN VFR. HIB REPORTED A TRACE OF ICE ACCUMULATION AT 06Z. IT'S
HARD TO DETERMINE WHETHER THAT WAS FROM VERY LIGHT FREEZING
DRIZZLE OR DIRECT DEPOSITION IN THE ABSENCE OF PRECIPITATION.
THE RISK OF VERY LIGHT FREEZING DRIZZLE IS LOW, BUT NOT ZERO
(AROUND 10%). FORCING FOR ASCENT IS WEAKER THAN EXPECTED EARLY
THIS MORNING WHICH IS ALSO LIMITING CONFIDENCE. THERE ARE TWO
MAIN OUTCOMES. EITHER THE STRATUS WILL CONTINUE TO EXPAND AND
WOULD THEN PERSIST THROUGH MUCH OF THE DAY OR THE LIFT WILL BE
INSUFFICIENT TO GENERATE WIDESPREAD STRATUS LEAVING RADIATIONAL
FOG AS THE ONLY CONCERN DURING THE DAY. I KEPT A MORE
PESSIMISTIC FORECAST FOR NOW. LLWS WILL DEVELOP THIS EVENING. A
LOW PRESSURE SYSTEM WILL DRIFT PAST THE NORTHLAND IN ONTARIO AND
MAY PRODUCE LIGHT RAIN AT INL THIS EVENING. WARM AIR ADVECTION
WILL STRENGTHEN THIS EVENING AND WIDESPREAD FOG WILL DEVELOP
AFTER 20.00Z AND MAY PERSIST THROUGH MUCH OF FRIDAY.
MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/
ISSUED AT 422 AM CDT THU MAR 19 2026
WINDS WILL BE FROM THE EAST TO SOUTHEAST TODAY AND WILL VEER
SOUTHWESTERLY TONIGHT AS A LOW PRESSURE SYSTEM PROPAGATES
SOUTHEASTWARD ACROSS NORTHWEST ONTARIO. SUSTAINED WINDS OF 5 TO
10 KNOTS ARE FORECAST AND WILL INCREASE TO 8 TO 15 KNOTS FOR THE
WATERS OF THE SOUTH SHORE TONIGHT. HAZARDOUS CONDITIONS ARE NOT
EXPECTED AT THIS TIME. FOG IS FORECAST TO DEVELOP ONSHORE
TONIGHT AND MAY ADVECT ONTO THE WATER. IF THAT OCCURS, EXPECT
VISIBILITY LESS THAN 1 MILE NEAR THE SHORE. THE NEXT PERIOD OF
HAZARDOUS CONDITIONS IS FORECAST FOR THE WEEKEND WHEN A STRONGER
LOW PRESSURE SYSTEM IS FORECAST TO PASS OVER THE REGION. STRONG
EAST AND NORTHEASTERLY WINDS WILL DEVELOP SATURDAY AFTERNOON
AND BECOME HAZARDOUS DURING THE EVENING HOURS. THERE IS A 20-30%
CHANCE OF LOW-END GALES ALONG THE NORTH SHORE AND THE SOUTHWEST
ARM SATURDAY NIGHT AND EARLY SUNDAY MORNING. WAVES WILL BUILD
TO 3 TO 9 FEET WITH THE HIGHEST VALUES IN THE WATERS OF THE
SOUTHWEST ARM AND OVER THE OUTER APOSTLE ISLANDS. WINDS ARE
FORECAST TO WEAKEN SUNDAY AFTERNOON AND NIGHT. SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED.
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...HUYCK
AVIATION...HUYCK
MARINE...HUYCK
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