814
FXUS63 KMKX 201550
AFDMKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
950 AM CST WED NOV 20 2024
KEY MESSAGES
- SCATTERED SNOW SHOWERS THIS AFTERNOON AND EVENING. THE MAIN
TRAVEL IMPACT FOR THE AFTERNOON COMMUTE IS REDUCED VISIBILITY.
- A BURST OF ACCUMULATING SNOW IS EXPECTED EARLY THURSDAY
MORNING, TRANSITIONING TO A RAIN/SNOW MIX BY THE AFTERNOON.
REDUCED VISIBILITES WITH GUSTY WINDS AND SLUSHY ACCUMULATIONS
ON ROADS WILL IMPACT THE MORNING COMMUTE. A WINTER WEATHER
ADVISORY IS IN EFFECT FOR SOUTHEAST WISCONSIN.
- STRONG WESTERLY WINDS ARE EXPECTED THURSDAY. WINDS WILL
APPROACH 45 MPH FOR MUCH OF SOUTHERN WISCONSIN. GALE FORCE
WINDS ARE EXPECTED ON LAKE MICHIGAN.
UPDATE
ISSUED 951 AM CST WED NOV 20 2024
THE FORECAST REMAINS ON TRACK AS OF MID-MORNING. CURRENT SURFACE
OBSERVATIONS PLACE A TROUGH/SECONDARY COLD FRONT ALONG AN
APPROXIMATE WATERLOO, IA - LA CROSSE - BLACK RIVER FALLS AXIS.
ALOFT, WATER VAPOR IMAGERY DEPICTS AN AREA OF CLOSED LOW
PRESSURE CENTERED OVER THE MN BOUNDARY WATERS. INCREASING LIFT
ALONG/AHEAD OF THE ENCROACHING SURFACE BOUNDARY & MID-LEVEL
DISTURBANCE WILL SUPPORT SCATTERED SNOW SHOWERS ACROSS THE
REGION THIS AFTERNOON AND EVENING. PRECIP MAY BRIEFLY BEGIN AS A
RAIN/SLEET MIX OVER SOUTHEASTERN AND EAST-CENTRAL WI---
PARTICULARLY NEAR THE WARMER WATERS OF LAKE MICHIGAN---PRIOR TO
QUICKLY TRANSITIONING TO ALL SNOW AS THE COLUMN RAPIDLY COOLS
ALONG/BEHIND THE PASSING SURFACE TROUGH/FRONT. WHILE
ACCUMULATIONS AREN'T ANTICIPATED IN THIS ACTIVITY, ~50-100 J/KG
OF CAPE DEPICTED IN FORECAST SOUNDINGS WILL SUPPORT EMBEDDED
CELLULAR ELEMENTS WITHIN THIS AFTERNOON'S SNOW SHOWERS. SAID
CELLULAR ELEMENTS WILL HELP TO CONTRIBUTE TO ABRUPT REDUCTIONS
IN VISIBILITY. THOSE WITH TRAVEL PLANS THIS AFTERNOON, AS WELL
AS THIS EVENING DURING THE COMMUTE HOME, SHOULD PLAN TO BUDGET
EXTRA TIME IN DOING SO.
QUIGLEY
SHORT TERM
ISSUED 503 AM CST WED NOV 20 2024
TODAY AND TONIGHT:
THE LIGHT RETURNS ON THE RADAR EARLY THIS MORNING ARE ASSOCIATED
WITH AN AREA OF 700MB FRONTOGENESIS. SO FAR, THE SURFACE
OBSERVATIONS ARE NOT INDICATING THAT RAIN IS REACHING THE
GROUND. HOWEVER, WE HAVE SOME LOW CLOUDS IN PLACE NEAR THE
LAKESHORE IN SOUTHEAST WI, AND THE 700MB FGEN IS ALSO
STRENGTHENING AS IT SLIDES EASTWARD. SOME LIGHT RAIN IS POSSIBLE
IN SOUTHEAST WI THROUGH 8 AM.
WE WILL REMAIN STUCK IN CYCLONIC FLOW ALL DAY. GIVEN THE
WEAKENING LOW OVER SOUTHERN MANITOBA AND THE STRENGTHENING LOW
OVER LAKE HURON, I AM NOT OPTIMISTIC THAT THE AREA OF CLEAR SKY
CURRENTLY OVER SOUTHEAST MN WILL MAKE IT ALL THE WAY INTO
EASTERN WI THIS MORNING.
RAPID CYCLOGENESIS WILL OCCUR NEAR SOUTHERN LAKE HURON THIS
AFTERNOON AS A STRONG SHORTWAVE TROUGH SWINGS FROM IL INTO LOWER
MI AND THE CLOSED UPPER LOW SPINNING OVER NORTHERN MN TAKES ON A
NEGATIVE TILT. THE PRECIP ASSOCIATED WITH THAT NORTHERN MN LOW
WILL SLIDE INTO SOUTHERN WI THIS AFTERNOON. AS THE LAKE HURON
LOW STRENGTHENS, THE PRECIP WILL BECOME MORE SHOWERY AS IT
PUSHES INTO SOUTHERN WI DUE TO THE STEEP LOW LEVEL LAPSE RATES.
THESE SHOWERS MAY INITIALLY BE A MIX OF RAIN AND SNOW (WITH
ONLY SHALLOW DENDRITIC ZONE SATURATION ON FORECAST SOUNDINGS,
AND SFC AIR TEMPS IN THE LOWER 40S LEADING TO MELTING), BUT
SHOULD TRANSITION TO ALL SNOW QUICKLY AS CLOUD ICE INCREASES AND
SURFACE TEMPS FALL INTO THE MID/LOW 30S THROUGH LATE AFTERNOON.
THE MILD AIR TEMPERATURES AND THE INTERMITTENT SNOW MAKE THIS
ROUND OF PRECIP RELATIVELY LOW IMPACT, BUT SUDDEN REDUCTIONS IN
VISIBILITY (BRIEF BURSTS OF MODERATE SNOW) WILL BE A CONCERN FOR
THE AFTERNOON COMMUTE. THE PEAK PERIOD OF SCATTERED SNOW SHOWERS
WILL BE 1 TO 6 PM. GUSTY WINDS WILL ACCOMPANY THE SNOW, WITH
HIGHEST GUSTS UP TO 30 MPH TOWARD THE WI/IL BORDER.
WHILE CLEARING SKIES ARE NOT EXPECTED TONIGHT, THERE SHOULD BE
STRONG ENOUGH COLD AIR ADVECTION TO COOL OUR AIR TEMPERATURES
DOWN TO AROUND 30. THE BRISK WESTERLY WINDS WILL CAUSE OUR WIND
CHILL VALUES TO BE IN THE UPPER TEENS. ANY LINGERING SNOW
SHOWERS OVERNIGHT WILL BE LARGELY CONFINED TO AREAS ALONG AND
SOUTH OF THE I-94 CORRIDOR, AS THE BETTER FORCING AND MOISTURE
SAG SOUTHWARD.
CRONCE
LONG TERM
ISSUED 503 AM CST WED NOV 20 2024
THURSDAY:
A BURST OF SNOW IS EXPECTED THURSDAY MORNING THAT COULD ADD UP
TO 3 INCHES IN 3 HOURS OVER A PORTION OF SOUTHEAST WI. GIVEN
THAT IT IS THE FIRST SNOW OF THE SEASON AND FALLING DURING THE
MORNING COMMUTE, WE ISSUED A WINTER WEATHER ADVISORY.
THERE IS CONSISTENCY IN THE MODEL RUNS PRODUCING A STRONG,
RETROGRADING SURFACE LOW THAT IS FORECAST TO TRACK FROM NORTHERN
LAKE HURON AROUND MIDNIGHT TO CENTRAL LAKE MICHIGAN MID
THURSDAY MORNING, AND THE SOUTHERN TIP OF LAKE MICHIGAN BY MID
THURSDAY AFTERNOON. THE ONLY OPERATIONAL MODEL OUTLIER IS THE
NAM FOR THE SURFACE LOW LOCATION, BUT THE PRECIP AMOUNT IS
CONSISTENT WITH THE OTHER MODELS. HOWEVER, THE NAM STILL TRIES
TO BRING THE PRECIP INTO SOUTHERN WI NEARLY 3 HOURS LATER THAN
THE GFS, ECMWF, HRRR, AND WRF-ARW MODELS. OUR FORECAST USES THE
MAJORITY OF THE MODELS, BUT IT'S IMPORTANT TO ACKNOWLEDGE THIS
DISCREPANCY BECAUSE IF THE NAM IS RIGHT, THE TEMPS MAY BE TOO
MILD FOR THE HIGHER SNOWFALL TOTALS WE ARE PREDICTING.
THERE SHOULD BE ONE PRIMARY SNOW BAND WHEREVER THE LOW LEVEL
FRONTOGENESIS LINES UP, BUT WIDESPREAD SNOW IS EXPECTED ACROSS
ALL OF SOUTHERN WI BETWEEN 6 AND 9 AM. BY MID THURSDAY MORNING,
MILDER AIR WRAPPING IN BEHIND THE SYSTEM WILL HELP CHANGE SNOW
OVER TO RAIN. SNOWFALL RATES UNDER THE PRIMARY BAND HAVE A 60
PERCENT CHANCE OF BEING GREATER THAN 1 INCH PER HOUR PER THE 00Z
HREF, LINING UP WITH THE AXIS OF THE KETTLE MORAINE. ANY SHIFT
IN THE SYSTEM WEST OR EAST WOULD CHANGE THE LOCATION OF THAT
FORECAST HEAVIER SNOWFALL. THUS, WE WENT WITH A BROAD AREA FOR
THE WINTER WEATHER ADVISORY.
ANY ACCUMULATIONS FROM THE MORNING WILL LIKELY MELT DURING THE
AFTERNOON. THUS, NOT EXPECTING MUCH OF AN IMPACT TO THE AFTERNOON
COMMUTE.
WINDS ARE THE OTHER STORY FOR THURSDAY. WITH THE STRONG LOW,
PROBABLY BEING ENHANCED BY THE WARM LAKE MICHIGAN, WESTERLY
WINDS IN EXCESS OF 40 MPH ARE LIKELY FOR THE MIDDAY AND
AFTERNOON HOURS. HIGHEST GUSTS WILL BE IN SOUTHEAST WI. GUSTS
TO 45 MPH WOULD BE WIND ADVISORY CRITERIA. GIVEN THAT THE
FORECAST IS RIGHT UP TO THAT POINT, I DID NOT HAVE ENOUGH
CONFIDENCE TO ISSUE A WIND ADVISORY ON THIS SHIFT.
FRIDAY THROUGH TUESDAY:
MAINLY DRY WEATHER IS EXPECTED FOR FRIDAY INTO THE WEEKEND AS
WEAK HIGH PRESSURE LEANS INTO THE AREA FROM THE WEST. LOOKS LIKE
TEMPS SHOULD BE RIGHT AROUND NORMAL THROUGH SATURDAY, POSSIBLY
WARMING BACK TOWARDS 50 ON SUNDAY AS WEAK UPPER RIDGING PUSHES
IN. THE PATTERN LOOKS MORE ACTIVE THEN EARLY WEEK, WITH A RETURN
OF PRECIP CHANCES. NOT A LOT OF CERTAINTY AT THIS POINT WITH
TIMING AND TYPE OF PRECIP GIVEN THE SPREAD AMONG MODELS.
CRONCE
AVIATION
ISSUED 951 AM CST WED NOV 20 2024
VFR CONDITIONS PREVAIL THROUGH EARLY THIS AFTERNOON AT ALL
TERMINALS, WITH -SHSN, REDUCED VIS READINGS, AND ATTENDANT
CATEGORICAL REDUCTIONS ARRIVING FROM THE WEST BY LATE
AFTERNOON AND TONIGHT. THE CURRENT FORECAST CALLS FOR PREVAILING
MVFR WITHIN THE AFOREMENTIONED -SHSN, THOUGH BRIEF PERIODS OF
IFR ARE POSSIBLE WITHIN THE HEAVIEST OF ACTIVITY. PRECIP WILL
BRIEFLY TAPER OVERNIGHT, PRIOR TO THE ARRIVAL OF ADDITIONAL SN
AND PERIODS OF +SN THURSDAY MORNING. THIS ROUND OF PRECIP WILL
MAINTAIN PREVAILING MVFR REGIONALLY, WITH PERIODS OF PREVAILING
IFR POSSIBLE AT EAST-CENTRAL AND SOUTHEASTERN TERMINALS WHERE
+SN IS MOST LIKELY. WILL MONITOR TRENDS THROUGH TODAY/TONIGHT
AND MAKE TIMING ADJUSTMENTS AS NECESSARY.
QUIGLEY
MARINE
ISSUED 503 AM CST WED NOV 20 2024
STRONG LOW PRESSURE OF 29.3 INCHES OVER SOUTHERN MANITOBA WILL
WEAKEN TODAY. MEANWHILE, ANOTHER SURFACE LOW OF 29.3 INCHES WILL
DEVELOP OVER LAKE HURON AND RETROGRADE WESTWARD TO NORTHERN LAKE
MICHIGAN BY THURSDAY MORNING, WHILE DEEPENING TO AROUND 29.2
INCHES.
WESTERLY WINDS WILL STRENGTHEN TODAY AS THE SECOND LOW DEVELOPS.
A GALE WARNING IS IN EFFECT LATE TONIGHT THROUGH THURSDAY EVENING
FOR THE OPEN WATERS OF LAKE MICHIGAN AS THE SECOND LOW CONTINUES
TO DEEPEN AND TRACKS FROM NORTH TO SOUTH DOWN THE EASTERN EDGE OF
THE LAKE. GALES TO 35-45 KT ARE FORECAST DURING THIS PERIOD, WITH
WINDS VEERING FROM NORTHWEST TO DUE NORTH AS THE LOW PASSES BY.
NORTHWEST WINDS REMAIN GUSTY INTO FRIDAY, WITH GALES POSSIBLE
THROUGH FRIDAY NIGHT.
CRONCE
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.
VISIT US AT WEATHER.GOV/MILWAUKEE
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSMILWAUKEE
WWW.TWITTER.COM/NWSMILWAUKEE
WWW.YOUTUBE.COM/NWSMILWAUKEE
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page