908
FXUS63 KMKX 190357
AFDMKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
957 PM CST WED DEC 18 2024
KEY MESSAGES
- SNOWFALL IS EXPECTED THURSDAY MORNING INTO THURSDAY NIGHT,
WITH WIDESPREAD ACCUMULATIONS OF 3 TO 6 INCHES. IMPACTS TO THE
MORNING COMMUTE ARE EXPECTED FROM MADISON NORTHWESTWARD, WITH
IMPACTS TO THE EVENING COMMUTE ACROSS ALL OF SOUTHERN
WISCONSIN. A WINTER WEATHER ADVISORY IS IN EFFECT FROM SAUK,
DANE, JEFFERSON, WAUKESHA, AND MILWAUKEE COUNTIES NORTHWARD.
- LAKE MICHIGAN COUNTIES WILL SEE LAKE EFFECT SNOW SHOWERS
LINGER INTO FRIDAY MORNING, POTENTIALLY IMPACTING THE MORNING
COMMUTE ACROSS SHEBOYGAN, WASHINGTON, OZAUKEE, WAUKESHA, AND
MILWAUKEE COUNTIES. A WINTER WEATHER ADVISORY REMAINS IN
EFFECT THROUGH MIDDAY FRIDAY FOR THESE REGIONS.
- THE NEXT ROUND OF ARCTIC AIR SETTLES INTO SOUTHERN WISCONSIN
THIS WEEKEND, WITH TEMPERATURES SETTLING BACK TOWARD NORMAL
INTO EARLY NEXT WEEK.
- THE NEXT CHANCES FOR ACCUMULATING SNOWFALL DEVELOP MONDAY INTO
MONDAY NIGHT.
UPDATE
ISSUED 957 PM CST WED DEC 18 2024
THE FORECAST REMAINS LARGELY ON TRACK AS OF MID-EVENING.
REGIONAL RADAR MOSAICS SHOW AN AREA OF LIGHT TO MODERATE SNOW
PROGRESSING ACROSS THE DAKOTAS. SAID AREA OF SNOW IS BEING
FORCED BY A STACKING OF LOW-MID LEVEL WAA, DPVA AHEAD OF AN
EJECTING ALBERTA CLIPPER, AND UPPER DIVERGENCE WITHIN A 300 MB
LEFT EXIT REGION. SAID AREA OF SNOWFALL WILL TRANSLATE EAST-
SOUTHEAST TOWARD THE UPPER MISSISSIPPI VALLEY WITH ITS PARENT
FORCING MECHANISMS DURING THE OVERNIGHT HOURS, OVERSPREADING
CENTRAL WISCONSIN & OUR NORTHWESTERN COUNTIES SHORTLY AFTER
SUNRISE THURSDAY MORNING. ANTICIPATE THAT STACKED SYNOPTIC
ASCENT WILL CONTINUE TO ACCOMPANY SNOW AS IT PROGRESSES INTO THE
NORTHWEST CORNER OF THE AREA, SUPPORTING MODERATE TO PERHAPS
BRIEFLY HEAVY SNOWFALL RATES TO THE NORTHWEST OF MADISON DURING
THE MORNING COMMUTE. BUDGET EXTRA TIME IF COMMUTING IN THESE
LOCATIONS TOMORROW MORNING. ADDITIONAL PERIODS OF LIGHT TO
OCCASIONALLY MODERATE SNOW WILL CONTINUE AREAWIDE INTO THURSDAY
AFTERNOON AS SYNOPTIC ASCENT OVERSPREADS THE ENTIRETY OF
SOUTHERN WISCONSIN. ALL COMMUTERS ARE ENCOURAGED TO BUDGET EXTRA
TIME DURING TOMORROW EVENING'S COMMUTE. CONTINUE TO MONITOR
TRENDS REGARDING POTENTIAL LAKE-ENHANCED SNOWFALL THURSDAY NIGHT
INTO FRIDAY MORNING OVER EAST-CENTRAL AND SOUTHEASTERN
WISCONSIN, AS HEAVIER SNOWFALL RATES AND IMPACTS TO THE FRIDAY
MORNING COMMUTE WOULD BE POSSIBLE IN ANY SUCH ACTIVITY. UPDATES
TO THE FORECAST WILL BE MADE AS EVENING GUIDANCE CONTINUES TO
FILTER IN.
QUIGLEY
SHORT TERM
ISSUED 314 PM CST WED DEC 18 2024
TONIGHT THROUGH FRIDAY:
OVERCAST SKIES AND NORTHWESTERLY WINDS CONTINUE THROUGH THIS
EVENING, WITH WINDS CALMING OVERNIGHT AS A BRIEF RIDGE OF HIGH
PRESSURE MOVES OVERHEAD. EXPECT OVERNIGHT LOWS IN THE UPPER
TEENS TO LOWER 20S, WITH TRENDS A COUPLE DEGREES WARMER DUE TO
OVERCAST SKIES ACTING AS A BLANKET ACROSS THE REGION.
THURSDAY MORNING, A CLIPPER SYSTEM APPROACHES FROM THE NORTHEAST
AND SPREADS LIGHT TO MODERATE SNOWFALL ACROSS SOUTHERN
WISCONSIN. SNOW BEGINS IN SOUTHWESTERN WISCONSIN BETWEEN 6 AND 9
AM CST, IMPACTING THE MADISON AREA NORTHWESTWARD FOR THE MORNING
COMMUTE. BY MID-MORNING, SNOW SPREADS INTO THE REMAINDER OF
SOUTHERN WISCONSIN. THE HEAVIEST RATES UP TO 0.5 INCH PER HOUR
WILL DEVELOP MID-MORNING AND CONTINUE THROUGH THE LATE EVENING
HOURS, IMPACTING THE EVENING COMMUTE WITH SLIPPERY TRAVEL.
SNOW/LIQUID RATIOS ARE EXPECTED TO BE NEARING 16:1 DUE TO
TEMPERATURES IN THE 20S, WHICH IMPLIES FLUFFY, LIGHT SNOWFALL.
THAT BEING SAID, SLIPPERY TRAVEL IS EXPECTED ACROSS UNTREATED
ROADS AND AREAS SEEING THE HIGHEST RATES.
LIGHT SNOW BECOMES DOMINANT THURSDAY EVENING. HOWEVER, AS THE
CLIPPER EXITS TO THE EAST FRIDAY MORNING, A LOBE OF VORTICITY
PIVOTING AROUND THE NORTHWESTERN SIDE OF THE LOW MAY ENHANCE
SNOWFALL RATES ONCE AGAIN ACROSS SOUTHEASTERN WISCONSIN. AT THE
SAME TIME, WINDS SHIFT TO BECOME NORTHEASTERLY OFF LAKE
MICHIGAN, LEADING TO LAKE ENHANCEMENT AND LAKE EFFECT SHOWERS
ACROSS THE LAKE MICHIGAN COUNTIES. THE WINTER WEATHER ADVISORY
REMAINS IN EFFECT THROUGH NOON FRIDAY IN SHEBOYGAN, WASHINGTON,
OZAUKEE, WAUKESHA, AND MILWAUKEE COUNTIES FOR THESE CONCERNS.
SNOW ENDS AS WINDS TURN NORTHWESTERLY FRIDAY AFTERNOON.
MH
LONG TERM
ISSUED 314 PM CST WED DEC 18 2024
FRIDAY NIGHT THROUGH WEDNESDAY:
NLY WINDS WILL DIMINISH FRI NT AS A N-S SFC RIDGE APPROACHES FROM
MN AND IA. THE SFC RIDGE WILL THEN GRADUALLY MOVE ACROSS WI ON
SAT. POLAR AIR WILL RESIDE OVER SRN WI FOR THE WEEKEND WITH LOWS
IN THE SINGLE DIGITS, AND TEENS BY THE LAKE. HIGHS WILL ONLY WARM
TO NEAR 20F ON SAT BUT CLOSE TO 30F ON SUN AS SLY WINDS AND WARM
ADVECTION ENSUE. NO PCPN IS FORECAST ALTHOUGH ONE OR TWO
VORTICITY MAXIMUMS IN NNWLY FLOW ALOFT WILL SKIM BY TO THE WEST.
SLY WINDS AND WARM ADVECTION WILL THEN CONTINUE INTO MON WITH A
SHORTWAVE TROUGH APPROACHING FROM SD AND MN. THE TROUGH WILL PASS
DURING THE DAY WITH LIGHT SNOW BECOMING LIKELY VIA WARM ADVECTION
AND PVA. THE LIGHT SNOW MAY LINGER INTO MON EVENING.
A QUASI-ZONAL FLOW AND WEAK SFC WINDS WILL THEN PREVAIL INTO
CHRISTMAS DAY WITH ABOVE NORMAL TEMPS.
GEHRING
AVIATION
ISSUED 957 PM CST WED DEC 18 2024
A MIX OF MVFR AND VFR FLIGHT CATEGORIES PREVAIL AT SOUTHERN
WISCONSIN TERMINALS THIS EVENING, THANKS TO AN OVC DECK BASED
BETWEEN FL025 AND FL035. HAVE ATTEMPTED TO ACCOUNT FOR RECENT OBS
TRENDS IN THE NEAR-TERM FORECAST AT ALL TERMINALS, WITH SIMILAR
CONDITIONS TO THOSE CURRENTLY ONGOING CONTINUING INTO EARLY THURSDAY
MORNING. CURRENTLY EVIDENT OVER THE NORTHERN GREAT PLAINS, AN UPPER
DISTURBANCE WILL CROSS SOUTHERN WISCONSIN FROM THE LATE THURSDAY
MORNING INTO THURSDAY EVENING, BRINGING PERIODS OF -SN/SN, LOWERED
CIG/VIS READINGS, AND ATTENDANT CATEGORICAL REDUCTIONS. ANTICIPATE
THAT THE STEADIEST SNOWS WILL OCCUR DURING THE AFTERNOON HOURS ON
THURSDAY, WHICH HAS BEEN REFLECTED IN THE LATEST FORECAST. LAKE
ENHANCEMENT WILL ALLOW SNOW TO CONTINUE INTO THURSDAY NIGHT & FRIDAY
MORNING OVER EAST-CENTRAL AND SOUTHEASTERN WISCONSIN, LIKELY
BRINGING ADDITIONAL IMPACTS TO KSBM AND KMKE.
QUIGLEY
MARINE
ISSUED 314 PM CST WED DEC 18 2024
BRISK NORTHWEST WINDS CONTINUE HIGH PRESSURE BUILDS INTO THE
UPPER MISSISSIPPI RIVER VALLEY. WINDS WILL DIMINISH TONIGHT AND
REMAIN LIGHT INTO THURSDAY MORNING AS HIGH PRESSURE MOVES ACROSS
LAKE MICHIGAN. WINDS WILL SHIFT TO BECOME SOUTHEASTERLY DURING
THE DAY THURSDAY AS LOW PRESSURE APPROACHES LAKE MICHIGAN FROM
THE UPPER MISSISSIPPI VALLEY. EXPECT RAIN AND SNOW SHOWERS
THROUGHOUT THE DAY THURSDAY INTO THURSDAY NIGHT. WINDS AND WAVES
IN NEARSHORE REGIONS WILL BECOME ELEVATED, LEADING TO A SMALL
CRAFT ADVISORY THURSDAY AFTERNOON THROUGH FRIDAY EVENING.
LOW PRESSURE MOVES SOUTHEASTWARD ACROSS THE SOUTHERN HALF OF
THE OPEN WATERS OVERNIGHT THURSDAY, BRINGING A LULL IN WINDS TO
THE SOUTHERN HALF AND SLOWLY BACKING WINDS TO BECOME NORTHERLY
IN THE NORTHERN HALF. THE LOW WILL PROGRESS EAST OF THE OPEN
WATERS INTO FRIDAY MORNING, RESULTING IN GUSTY NORTH WINDS
ACROSS THE LAKE. NORTHERLY WINDS CONTINUE INTO SATURDAY, SLOWLY
DIMINISHING AS LOW PRESSURE EXITS EASTWARD.
MH
MKX WATCHES/WARNINGS/ADVISORIES
WI...WINTER WEATHER ADVISORY...WIZ046-WIZ047-WIZ051-WIZ056-WIZ057-
WIZ058-WIZ063-WIZ064...6 AM THURSDAY TO 6 AM FRIDAY.
WINTER WEATHER ADVISORY...WIZ052-WIZ059-WIZ060-WIZ065-
WIZ066...9 AM THURSDAY TO NOON FRIDAY.
LM...SMALL CRAFT ADVISORY...LMZ643-LMZ644...2 PM THURSDAY TO 6 PM
FRIDAY.
SMALL CRAFT ADVISORY...LMZ645-LMZ646...2 PM THURSDAY TO
MIDNIGHT SATURDAY.
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