418
FXUS63 KDLH 171734
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
1134 AM CST SUN NOV 17 2024
KEY MESSAGES
- DRY WEATHER TODAY THROUGH MONDAY AFTERNOON, EXCEPT VERY LIGHT
RAIN SHOWERS IN THE BORDERLANDS THIS MORNING.
- WIDESPREAD MODERATE TO LOCALLY HEAVY RAINFALL FORECAST
BEGINNING MONDAY EVENING AND LASTING INTO TUESDAY EVENING AS
A LARGE WEATHER SYSTEM LIFTS SOUTH TO NORTH.
- EASTERLY WINDS GUSTING TO 45 MPH MONDAY NIGHT INTO TUESDAY
MORNING FOR COASTAL LOCATIONS NEAR LAKE SUPERIOR.
- WINTRY MIX EXPECTED MID-WEEK AFTER THE MODERATE RAIN WRAPS UP
TUESDAY NIGHT.
DISCUSSION
ISSUED AT 315 AM CST SUN NOV 17 2024
SURFACE LOW PRESSURE CENTERED IN THE ND/MN STATELINE AREA EARLY
THIS MORNING IS CREATING A WEAK COLD FRONT PASSING ACROSS THE
NORTHLAND. WHILE NO SIGNIFICANT TEMPERATURE DROPS ARE EXPECTED
WITH THIS FRONTAL PASSAGE, A WIND SHIFT TO SOUTHWESTERLY IS
BEING OBSERVED ON SURFACE OBSERVATIONS IN NORTHWEST MINNESOTA.
THESE WINDS EVENTUALLY MOVE INTO NORTH-CENTRAL MINNESOTA OVER
THE NEXT FEW HOURS AND THEN FURTHER EASTWARD DURING THE DAYLIGHT
MORNING HOURS TODAY. AS DEEPER MIXING OCCURS BEHIND THE FRONT,
EXPECT ANOTHER DAY OF WINDS GUSTING 20 TO 30 MPH THROUGH THIS
AFTERNOON. THE SURFACE TRACK OF THE LOW PRESSURE EVENTUALLY
MOVING INTO NORTHWEST ONTARIO LATER TODAY KEEPS LOW-LEVEL
STRATUS CLOUDS IN PLACE LONGEST FOR THE IRON RANGE AND
BORDERLANDS THIS AFTERNOON, ELSEWHERE IN THE NORTHLAND WILL
CLEAR IN THE LATER MORNING TO MID-AFTERNOON HOURS TODAY FROM
SOUTH TO NORTH. ALL OF THIS WILL OCCUR WITH SURFACE TEMPERATURES
KEEPING IN THE 40S, OR ABOUT 8 TO 15 DEGREES ABOVE NORMAL.
DETERMINISTIC SHORT-RANGE HIGH-RES GUIDANCE SHOWS A FEW
VORTICITY MAXIMUMS ROTATING THROUGH THE LOW TO MID- LEVEL
PRESSURE CENTER LATER TODAY. AS RELATIVE HUMIDITY IN THE SIMILAR
COLUMN WHERE THIS LOCALIZED FORCING WILL BE LOCATED REMAINS IN
THE 80-90% RANGE, THE FORECAST FOR THE IRON RANGE AND
BORDERLANDS KEEPS A 20-40% CHANCE OF RAIN SHOWERS THROUGH MID-
AFTERNOON TODAY BEFORE A MUCH DRIER AIRMASS QUICKLY FOLLOWS THE
DEPARTING LOW PRESSURE. ELSEWHERE IN THE NORTHLAND THOUGH WILL
BE DRY TODAY.
WINDS QUICKLY CALM TONIGHT AS HIGH PRESSURE SETS UP OVER THE
REGION, LEADING TO LOW TEMPERATURES AIDED BY RADIATIONAL COOLING
IN THE UPPER-20S TO LOW-30S...ALSO ABOUT 10 TO 15 DEGREES ABOVE
NORMAL FOR SIMILAR OVERNIGHT LOW TEMPERATURES NORMALLY IN THE
UPPER-TEENS TO MID-20S FOR THIS TIME OF YEAR.
BY MONDAY AFTERNOON, LOW PRESSURE IN THE CENTRAL U.S. PLAINS
LIFTS A WARM FRONT NORTHWARD INTO THE UPPER MIDWEST. STRONG
SOUTHERLY MOIST AIR TAPPING INTO THE GULF OF MEXICO WILL PRODUCE
ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES (FORECAST AROUND 1.3"
IN DETERMINISTIC MEDIUM RANGE GUIDANCE AROUND THE TWIN CITIES
BREAKING PREVIOUS OBSERVED DAILY MAX OF 0.91" AT THE CHANHASSEN
UPPER AIR SITE FOR NOV 20 PER STORM PREDICTION CENTER.....FORECAST
AROUND 0.9" IN INTERNATIONAL FALLS WOULD APPROACH THE CURRENT
OBSERVED DAILY MAX OF 0.96" AT THE INTERNATIONAL FALLS UPPER AIR
SITE FOR NOV 20) BEGINNING MONDAY EVENING AND THROUGH TUESDAY.
AS THE BETTER FRONTAL-ASSOCIATED FORCING LIFTS NORTHWARD AS THE
LOW PRESSURE TRACKS INTO THE UPPER MIDWEST MONDAY NIGHT, EXPECT
INCREASING RAINFALL CHANCES FROM SOUTH TO NORTH. BY THE PRE-DAWN
HOURS OF EARLY TUESDAY MORNING, MUCH OF THE NORTHLAND IS
EXPECTED TO SEE A STEADY MODERATE RAINFALL WITH RATES AROUND 0.1
INCH PER HOUR AND LOCALIZED/PERIODICALLY TO 0.25 INCHES PER
HOUR. FOR STORM TOTAL RAINFALL AMOUNTS, THERE IS A 70-80% CHANCE
OF 0.5-1" OF RAINFALL ACROSS ALL OF THE NORTHLAND. LAKE AND
TERRAIN ENHANCEMENT IN THE EASTERN BAYFIELD PENINSULA AND ALONG
THE NORTH SHORE IS EXPECTED TO BOOST OBSERVED RAINFALL TOTALS
COMPARED TO THE REST OF THE REGION BY TUESDAY NIGHT. THESE
LOCATIONS HAVE A 40-60% CHANCE OF SEEING ANYWHERE FROM 1-2" OF
RAINFALL IN THIS TIME PERIOD. THE UPPER-END FORECAST OF RAIN
FOR THE COASTAL REGIONS OF LAKE AND COOK COUNTIES IS A 20-30%
CHANCE OF 2.5-3" OF RAINFALL.
WHILE THE RAIN BEGINS TO OVERSPREAD THE AREA MONDAY NIGHT, AN
INCREASED PRESSURE GRADIENT BUILDS OVER WESTERN LAKE SUPERIOR
WATERS. THIS RESULTS IN A FORECAST CALLING FOR STRONG EASTERLY
WINDS OVER THE WATERS REACHING THE COASTAL LAND AREAS OF THE
BAYFIELD PENINSULA, INTO THE TWIN PORTS AND ALL ALONG THE NORTH
SHORE. THERE IS A 50% CHANCE OF WIND GUSTS AT LEAST 40-45 MPH
LATE MONDAY NIGHT AND LASTING THROUGH TUESDAY LATE MORNING FOR
THE NORTH SHORE AND THE TIP OF THE BAYFIELD PENINSULA. FUTURE
WIND ADVISORIES MAY BE NEEDED FOR THIS TIME PERIOD IF CONFIDENCE
CONTINUES TO GROW IN THESE WINDS IMPACTING LOCAL AREAS NEAR
LAKE SUPERIOR.
THE PRIMARY FRONTAL-ASSOCIATED MODERATE RAINFALL ENDS TUESDAY
EVENING WITH THE BEST FORCING WELL-NORTH OF THE FORECAST REGION
AND THE LOW PRESSURE CENTERED OVER THE MN/ON/MB BORDER REGION.
MUCH COOLER WESTERLY FLOW WRAPPING AROUND THE LOW PRESSURE
FINALLY BEGINS TO ENTER THE NORTHLAND TUESDAY NIGHT, WHICH
CREATES THE FIRST CHANCES OF A WINTRY MIX IN NORTH-CENTRAL
MINNESOTA WEDNESDAY MORNING. AS THE COLDER AIR SLIDES INTO
NORTHWEST WISCONSIN WEDNESDAY DAYTIME, LINGERING LIGHT RAIN
SHOWERS TURN OVER TO ALL OF A WINTRY MIX CHANCE (20-40%). THIS
WILL ALSO BE THE START OF A PERIOD OF TEMPERATURES MUCH CLOSER
TO NORMAL...DAYTIME HIGHS IN THE 30S INLAND AND NEAR 40 ALONG
THE COASTAL AREAS. AT THIS POINT, ANY SNOWFALL ACCUMULATIONS ARE
EXPECTED TO BE FAIRLY LIGHT (LESS THAN A COUPLE OF INCHES) OVER
A TIME SPAN FROM WEDNESDAY INTO THURSDAY. GUIDANCE POINTS TO THE
LOW PRESSURE FINALLY EXITS THE BORDERLANDS INTO THE LOWER GREAT
LAKES THURSDAY PM. THIS CHANGE IS REFLECTED IN THE FORECAST WITH
DECREASING PRECIPITATION CHANCES FOR LAKE EFFECT SHOWERS BY
FRIDAY AFTERNOON.
HIGH PRESSURE IS PROGGED TO SETUP OVER THE CENTRAL U.S. TO BEGIN
NEXT WEEKEND AND PROMOTES LINGERING SEASONABLE AIRMASS TO KEEP
NEAR-NORMAL TEMPERATURES AND MAINLY DRY CONDITIONS IN PLACE FOR
NEXT SATURDAY.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 1134 AM CST SUN NOV 17 2024
MVFR CEILINGS CURRENTLY PREVAIL ACROSS MUCH OF THE NORTHLAND,
BUT A RAPID IMPROVEMENT TO VFR IS EXPECTED OVER THE NEXT FEW
HOURS AS THE BACK END OF THE CLOUD BANK EXITS THE AREA.
EXPECTING VFR CONDITIONS TO RETURN BY MID TO LATE AFTERNOON AND
THEN PREVAIL THROUGH THE REMAINDER OF THE PERIOD. GUSTY WESTERLY
WINDS TO 20 TO 30 KNOTS WILL CONTINUE THROUGH THE AFTERNOON
BEFORE BECOMING LIGHT AROUND 6 KNOTS OR LESS AROUND SUNSET.
MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/
ISSUED AT 210 AM CST SUN NOV 17 2024
LIGHT WINDS THIS MORNING QUICKLY INCREASE AGAIN IN SPEED OVER
THE WESTERN WATERS BEHIND A PASSING COLD FRONT. SOUTHWESTERLY
WINDS ARE FORECAST TO BE STRONGEST ALONG THE SOUTH SHORE WHERE
PARTS OF IT ARE COVERED IN A GALE WARNING. THE WARNING WAS
EXPANDED FURTHER NORTHWARD TOO EARLY THIS MORNING FOR INCREASED
CONFIDENCE IN GUSTS NEAR 35 KNOTS NORTH OF GRAND MARAIS ALONG
THE NORTH SHORE THIS AFTERNOON. THE REST OF THE NEARSHORE WATERS
ARE FORECAST TO BE AT OR LESS THAN 30 KNOT GUSTS SO SMALL CRAFT
ADVISORIES PREVAIL ELSEWHERE. AFTER THE FEW ZONES IN THE GALE
WARNING EXPIRE AT 4 PM TODAY, SMALL CRAFT ADVISORIES FOR
LINGERING GUSTY WINDS AND ELEVATED WAVE HEIGHTS ARE VERY LIKELY
TO BE NEEDED AT LEAST THROUGH THE EVENING HOURS TODAY. WINDS
DECREASE LATER SUNDAY NIGHT AND SHIFT EASTERLY MONDAY. THOSE
EASTERLY WINDS BEGIN TO CREATE ANOTHER ROUND OF CONDITIONS
HAZARDOUS TO SMALL CRAFT MONDAY EVENING AND ONWARD. THIS WILL BE
A PERIOD OF PROLONGED SMALL CRAFT ADVISORIES TO POTENTIAL (70%
CONFIDENCE) GALE WARNINGS FOR STRONG EASTERLY WINDS ALL ACROSS
THE WESTERN WATERS MONDAY NIGHT INTO TUESDAY.
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 PM CST THIS EVENING FOR LSZ121-
141>145-148.
GALE WARNING UNTIL 4 PM CST THIS AFTERNOON FOR LSZ140-146-147-
150.
DISCUSSION...NLY
AVIATION...BJH
MARINE...NLY
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