294
FXUS63 KMKX 202102
AFDMKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
302 PM CST WED NOV 20 2024
KEY MESSAGES
- THE FIRST SUBSTANTIAL SNOWFALL OF THE WINTER 2024-2025 SEASON ARRIVES
THURSDAY MORNING, WHEN A BRIEF BUT HEAVY ROUND OF SNOW WILL
TRACK ACROSS EAST-CENTRAL AND SOUTHEASTERN WISCONSIN. THE
ROUND OF SNOW WILL GENERALLY BRING BETWEEN 1-4" OF SNOW
ACCUMULATION TO EAST- CENTRAL AND SOUTHEASTERN WISCONSIN.
- A WINTER WEATHER ADVISORY REMAINS IN EFFECT BETWEEN 6 AM AND
NOON CST THURSDAY ACROSS THE EASTERN HALF OF THE AREA. ALL OF
THE MILWAUKEE METRO REMAINS INCLUDED IN THE ADVISORY. THE
MADISON METRO IS NOT INCLUDED IN THE ADVISORY.
- ADDITIONAL, MORE SCATTERED SNOW SHOWERS ARE EXPECTED ALONG A PASSING
FRONT THIS AFTERNOON AND EVENING. ACCUMULATION IS NOT
EXPECTED, THOUGH SNOW SHOWERS COULD BRING ABRUPT DROPS IN
VISIBILITY.
- A PROLONGED PERIOD OF GUSTY WINDS CONTINUES THROUGH THURSDAY NIGHT.
THE STRONGEST GUSTS ARE EXPECTED THURSDAY MORNING AND
AFTERNOON. SMALL CRAFT ADVISORIES AND GALE WARNINGS REMAIN IN
EFFECT IN NEARSHORE AND OPEN WATER ZONES.
- THE NEXT WIDESPREAD PRECIP CHANCE ARRIVES MONDAY, WITH MOSTLY
RAIN BEING FAVORED AT THIS TIME.
SHORT TERM
ISSUED 302 PM CST WED NOV 20 2024
TONIGHT THROUGH THURSDAY NIGHT:
SYNOPSIS/MESOANALYSIS: SURFACE OBSERVATIONS PLACE A TROUGH/SECONDARY
COLD FRONT ALONG AN APPROXIMATE DUBUQUE, IA - MADISON - STEVENS
POINT AXIS EARLY THIS AFTERNOON. THE SURFACE BOUNDARY IS POSITIONED
BENEATH AN AREA OF LOW PRESSURE IN THE MID-LEVELS OF THE ATMOSPHERE,
WITH GOES WATER VAPOR IMAGERY SHOWING THE FEATURE ADVANCING TOWARD
THE SOUTHERN HALF OF LAKE MICHIGAN AS OF 2:30 PM. LIFT FROM THE TWO
FEATURES WILL SUPPORT SCATTERED SNOW SHOWERS THROUGH THE REMAINDER
OF THE AFTERNOON AND THIS EVENING, WHICH COULD BRING ABRUPT
REDUCTIONS IN VISIBILITY DURING THE EVENING DRIVE HOME. TO OUR EAST,
DPVA AHEAD OF THE AFOREMENTIONED UPPER DISTURBANCE IS ENCOURAGING
SURFACE CYCLOGENESIS OVER SOUTHERN LAKE HURON, WHERE AN AREA OF SUB-
1000 MB SURFACE PRESSURES HAS BEEN NOTED IN RECENT OBSERVATIONS.
SAID SURFACE LOW WILL CONTINUE TO DEEPEN THIS AFTERNOON AND TONIGHT,
GRADUALLY RETROGRADING NORTHWEST TOWARD NORTHERN LAKE MICHIGAN AND
THE UPPER PENINSULA OF MICHIGAN. THE FEATURE WILL PROGRESS SOUTH
DOWN THE EASTERN HALF OF LAKE MICHIGAN DURING THE DAY ON TUESDAY.
THE LOW'S APPROACH FROM THE NORTHWEST, IN ADDITION TO INCREASING WAA
AND DPVA IN THE LOW-MID LEVELS, WILL DRIVE A ROUND OF BRIEF BUT
HEAVY SNOWFALL THURSDAY MORNING, PARTICULARLY OVER EAST-CENTRAL AND
SOUTHEASTERN WISCONSIN. THE TIMING OF SAID SNOWFALL WILL BRING
IMPACTS TO THE MORNING COMMUTE. A WINTER WEATHER ADVISORY IS IN
EFFECT BETWEEN 6 AM AND NOON THURSDAY, WHEN THE HEAVIEST SNOWFALL
RATES WILL BE MOVING ACROSS EAST-CENTRAL AND SOUTHEASTERN PORTIONS
OF THE AREA. PRECIPITATION WILL TRANSITION TO A RAIN-SNOW MIX LATE
THURSDAY MORNING, AND EVENTUALLY ALL RAIN BY THURSDAY AFTERNOON.
PRECIPITATION WILL TAPER BY THURSDAY EVENING. NORTHWEST WINDS
WILL BE GUSTY THROUGH THE DAY ON THURSDAY, WITH WIDESPREAD
35-40 MPH WINDS ANTICIPATED.
REST OF THIS AFTERNOON & THIS EVENING: THE ONGOING SCATTERED SNOW
SHOWERS WILL CONTINUE TO ADVANCE INTO & PERSIST ACROSS THE REGION.
WARM ANTECEDENT SURFACE AND PAVEMENT TEMPERATURES WILL PREVENT ANY
ACCUMULATION FROM OCCURRING, HOWEVER, BRIEF BOUTS OF MODERATE
SNOWFALL RATES ARE POSSIBLE AS ACTIVITY MOVES THROUGH. COMBINED WITH
THE GUSTY WEST/NORTHWEST WINDS IN PLACE ACROSS THE REGION, THIS
COULD RESULT IN ABRUPT DROPS IN VISIBILITY TO ONE MILE OR LESS.
THOSE DRIVING HOME THIS EVENING SHOULD THUS BUDGET EXTRA TIME AND
ALLOW FOR EXTRA FOLLOWING DISTANCE IN THE EVENT SCATTERED SNOW
SHOWERS ARE ENCOUNTERED.
THURSDAY MORNING & EARLY AFTERNOON: AN ABUNDANCE OF SYNOPTIC FORCING-
---NAMELY INCREASING WAA/ISENTROPIC ASCENT IN THE 850-700 MB
LAYER & DPVA ALOFT---WILL SUPPORT A PERIOD OF BRIEF BUT HEAVY
SNOWFALL OVER EAST-CENTRAL AND SOUTHEASTERN WISCONSIN AS LOW
PRESSURE MOVES DOWN LAKE MICHIGAN. SAID SYNOPTIC FORCING WILL
BE WELL-POSITIONED WITH RESPECT A DEEP AND SATURATED DGZ,
SUPPORTING EFFICIENT TO HEAVY (1- 1.5"+/HR) SNOWFALL RATES AS
ACTIVITY MOVES THROUGH. SATURATION OF THE DGZ, AS WELL AS
PRECIPITABLE WATERS AROUND 0.5", WILL ALSO SUPPORT A VERY WET
NATURE TO THE SNOW THAT FALLS. THE END RESULT WILL BE QUICK
ACCUMULATION OF SNOW ON GRASSY SURFACES. WHILE PAVEMENT
TEMPERATURES WILL STILL BE WELL-ABOVE FREEZING PRIOR TO THE
ONSET OF SNOW, THE HEAVY RATE OF SNOWFALL IS LIKELY TO LEAD TO
SOME SLUSH ACCUMULATION ON ROADS. IMPACTS TO THE THURSDAY
MORNING COMMUTE ARE THUS ANTICIPATED WITH THIS SNOWFALL, WITH A
WINTER WEATHER ADVISORY IN EFFECT BETWEEN 6 AM AND NOON CST
THURSDAY OVER EAST- CENTRAL AND SOUTHEASTERN WISCONSIN.
GENERALLY 1-4" OF SNOW ARE EXPECTED WITHIN THE ADVISORY AREA,
WITH THE LOWEST TOTALS BEING NEAR THE WARMER WATERS OF LAKE
MICHIGAN AND THE HIGHER TOTALS BEING ALONG THE KETTLE MORAINE.
A FEW TOTALS APPROACHING OR EVEN EXCEEDING 5" CAN'T BE RULED
OUT ALONG THE SHEBOYGAN-FOND DU LAC CO LINE, WHERE SNOW WILL
BEGIN TO FALL PRIOR TO SUNRISE & THE ONSET OF THE DIURNAL
CYCLE. PRECIPITATION WILL GRADUALLY TRANSITION TO A RAIN-SNOW
MIX BY LATE MORNING, AND EVENTUALLY ALL RAIN BY EARLY AFTERNOON
AS A MILDER AIR MASS FUNNELS INTO SOUTHERN WISCONSIN FROM THE
NORTHEAST. GIVEN THAT THIS IS THE FIRST APPRECIABLE SNOWFALL IN
SEVEN MONTHS, AND THE ANTICIPATED OVERLAP OF HEAVY SNOWFALL
RATES WITH THE MORNING COMMUTE, THOSE WITH THURSDAY MORNING
TRAVEL PLANS ARE STRONGLY ENCOURAGED TO BUDGET EXTRA TIME AND
ALLOW FOR PLENTY OF FOLLOWING DISTANCE. QUIGLEY
LONG TERM
ISSUED 302 PM CST WED NOV 20 2024
FRIDAY THROUGH WEDNESDAY:
FRIDAY THROUGH WEDNESDAY:
FRIDAY: AS THE DEPARTED LOW PRESSURE WEAKENS AND MERGES INTO
DEEPENING LOW PRESSURE OVER PENNSYLVANIA, NORTHWEST WINDS
CONTINUE, BUT AT A SLOWER PACE (15-20 MPH GUSTING TO 25-30). DRY
WEATHER LIKELY FOR ALL LAND AREAS, WITH A FEW LINGERING BANDS OF
RAIN OVER LAKE MICHIGAN. DAYTIME HIGHS IN THE MID 40S WITH MOSTLY
CLOUDY SKIES. FRIDAY NIGHT LOWS AROUND 30 DEGREES.
WEEKEND: TEMPERATURES NEAR OR JUST ABOVE SEASONAL NORMS SATURDAY
AND SUNDAY (HIGHS IN THE 40S, LOWS IN THE 30S). DRY WEATHER
THROUGH SUNDAY AFTERNOON. 15-30% RAIN CHANCE SUNDAY EVENING /
NIGHT AS A WEAK LOW PRESSURE TRACKS NORTHEASTWARD THROUGH IL.
MONDAY: AS WEAK LOW PRESSURE CONTINUES NORTHEASTWARD FROM IL AND
HIGH PRESSURE BUILDS INTO SOUTHERN CANADA MONDAY, PRECIP CHANCES
INCREASE TO 25-40%, MAINLY ON ACCOUNT OF COOLER AIR PUSHING IN
ALOFT (FROM THE WEST) AND SOME ASSOCIATED FGEN. OUR FORECAST
CALLS FOR RAIN TO REMAIN THE DOMINANT PRECIP TYPE THROUGHOUT THE
EVENT, BUT FORECAST SOUNDINGS DO SHOW THE POSSIBILITY THAT THE
LATTER HALF COULD SEE A TRANSITION TO WET SNOW. A HARD FREEZE IS
EXPECTED MONDAY NIGHT, BUT THE CURRENT FORECAST CALLS FOR PRECIP
CHANCES DIMINISH BELOW 15% BEFORE FREEZING SURFACE AIR TEMPS
ARRIVE.
REST OF THE PERIOD: SEASONABLY COOL TEMPERATURES (HIGHS IN THE
30S TO AROUND 40, LOWS IN THE 20S) ARE LOOKING LIKELY. MOSTLY
QUIET WEATHER THROUGH MID NEXT WEEK WITH HIGH PRESSURE BUILDING
JUST NORTH OF THE REGION.
SHEPPARD
AVIATION
ISSUED 302 PM CST WED NOV 20 2024
-SHSN ARE WORKING THEIR WAY INTO THE REGION THIS AFTERNOON AHEAD
OF AN APPROACHING SURFACE FRONT AND UPPER DISTURBANCE. WHILE
VFR CATEGORIES WILL PREVAIL ALONG THE IMMEDIATE LEADING EDGE OF
THIS PRECIP, EVENTUAL CIG/VIS REDUCTIONS AND ATTENDANT
DEGRADATIONS TO MVFR ARE ANTICIPATED AS -SHSN PERSIST LATE THIS
AFTERNOON/EARLY THIS EVENING. MOST SITES EXPERIENCING PRECIP
HAVE REMAINED AT MVFR, THOUGH BRIEF REDUCTIONS TO IFR HAVE BEEN
OCCASIONALLY NOTED THROUGH EARLY AFTERNOON. THUS CAN'T ENTIRELY
RULED OUT SOME BRIEF PERIODS OF IFR AT ALL FIELDS AS -SHSN
CONTINUE TO ADVANCE EAST THIS AFTERNOON, THOUGH CONFIDENCE IS
TOO LOW TO INCLUDE ANY TEMPO GROUPS AT THIS TIME. WILL MONITOR
OBSERVATIONAL TRENDS AND MAKE AMENDMENTS IF NECESSARY. EXPECT A
LULL IN PRECIP OVERNIGHT, PARTICULARLY ACROSS THE NORTHEAST,
BUT CAN'T ENTIRELY RULE OUT SOME ADDITIONAL -SN CLOSER TO THE
WI-IL STATE LINE. HAVE ACCOUNTED FOR THIS POTENTIAL WITH PROB30
GROUPS AT JVL AND MSN, AND PLAN TO MAKE AN INSERTION AT ENW IN
UPCOMING 21Z UPDATE. WILL MONITOR FOR ANY POTENTIAL NEED FOR
NORTHWARD EXPANSIONS OF PROB30'S INTO THE MKE VICINITY. ANOTHER
ROUND OF MORE SUBSTANTIAL SN/+SN WILL WORK INTO EAST-CENTRAL
AND SOUTHEASTERN WI THURSDAY MORNING, BRINGING ADDITIONAL
CIG/VIS REDUCTIONS AND A MIX OF IFR/MVFR CATEGORIES. NORTHWEST
WINDS WILL REMAIN GUSTY THROUGH THE PERIOD, REACHING THEIR
HIGHEST VALUES FOLLOWING SUNRISE THURSDAY.
QUIGLEY
MARINE
ISSUED 302 PM CST WED NOV 20 2024
AN ACTIVE PERIOD FEATURING WINTRY PRECIPITATION AND GUSTY NORTH-
NORTHWEST WINDS BEGINS OVERNIGHT AS 992 MB LOW PRESSURE
DEVELOPS OVER THE UPPER PENINSULA OF MICHIGAN. SAID LOW WILL
RETROGRADE INTO THE NORTHERN OPEN WATERS OF LAKE MICHIGAN BY
SUNRISE BY DAYBREAK THURSDAY, CONTINUING TO DEEPEN TO NEAR 990
MB IN THE PROCESS. THE DEVELOPMENT AND APPROACH OF THE SURFACE
LOW WILL RESULT IN INCREASING WIND GUSTS TONIGHT, WITH READINGS
RANGING BETWEEN 30-40 KNOTS ANTICIPATED BY SUNRISE OVER THE
WESTERN HALF OF THE LAKE. SIMILAR GUSTS WILL CONTINUE THROUGH
THURSDAY AFTERNOON AS THE AFOREMENTIONED SURFACE LOW DRIFTS
SOUTH ACROSS THE LAKE AND FILLS TOWARD 996 MB. GALE WARNINGS
THUS REMAIN IN EFFECT BETWEEN 12 AM AND 7 PM CST THURSDAY OVER
THE NORTHERN HALF OF THE OPEN WATERS, AND BETWEEN 3 AM CST
THURSDAY AND 12 AM CST FRIDAY ACROSS THE SOUTHERN HALF OF THE
OPEN WATERS. WAVE HEIGHTS BETWEEN 7-14 FEET WILL ACCOMPANY
THURSDAY AFTERNOON'S GUSTS.
GUSTY WEST TO NORTHWEST WINDS ARE ONGOING IN NEARSHORE ZONES THIS
AFTERNOON, SUPPORTING CONTINUED SMALL CRAFT ADVISORY CONDITIONS
THROUGH THIS EVENING. THE APPROACH OF RETROGRADING LOW PRESSURE FROM
THE NORTH WILL RESULT IN EVEN GREATER, NORTHWESTERLY GUST READINGS
APPROACHING DAYBREAK THURSDAY, WITH A GALE WARNING GOING INTO EFFECT
FROM SHEBOYGAN SOUTH TO WINTHROP HARBOR AT 3 AM CST THURSDAY
MORNING. 30-40 KNOT WINDS WILL BE ACCOMPANIED BY WAVE HEIGHTS
RANGING BETWEEN 4-10 FEET THURSDAY AFTERNOON. GUSTY WINDS AND
ELEVATED WAVE HEIGHTS WILL CONTINUE INTO THURSDAY EVENING, WITH THE
GALE WARNING REMAINING IN EFFECT UNTIL 12 AM FRIDAY. GUSTY NORTHWEST
WINDS---ALBEIT LIGHTER THAN THE READINGS EXPECTED ON THURSDAY---WILL
CONTINUE THROUGH FRIDAY IN NEARSHORE ZONES. AN ADDITIONAL SMALL
CRAFT ADVISORY WILL LIKELY BE NEEDED AS THIS PORTION OF THE PERIOD
DRAWS CLOSER.
QUIGLEY
MKX WATCHES/WARNINGS/ADVISORIES
WI...WINTER WEATHER ADVISORY...WIZ051-WIZ052-WIZ058-WIZ059-WIZ060-
WIZ064-WIZ065-WIZ066-WIZ070-WIZ071-WIZ072...6 AM THURSDAY
TO NOON THURSDAY.
LM...GALE WARNING...LMZ080-LMZ643-LMZ644-LMZ645-LMZ646-LMZ669-
LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ870-LMZ872-LMZ874-
LMZ876-LMZ878...3 AM THURSDAY TO MIDNIGHT FRIDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ868...MIDNIGHT THURSDAY TO 6 PM THURSDAY.
SMALL CRAFT ADVISORY...LMZ643-LMZ644-LMZ645-LMZ646 UNTIL 3 AM
THURSDAY.
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