024
FXUS63 KARX 130502
AFDARX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1202 AM CDT FRI MAR 13 2026
KEY MESSAGES
- TWO MAJOR WEATHER SYSTEMS REMAIN ON TARGET TO IMPACT THE
REGION WITH THE FIRST TONIGHT-FRIDAY MORNING AND THE SECOND
STORM COMING SATURDAY NIGHT - MONDAY MORNING.
- STORM #1: VERY STRONG WINDS GUSTING UP TO 50-60 MPH, STRONGEST
WEST OF THE MISSISSIPPI RIVER. LIGHT SNOW SHOWERS ACCOMPANYING
THESE WINDS COULD RESULT IN SNOW SQUALLS AND PERIODS OF
WHITEOUT CONDITIONS.
- STORM #2: A POTENTIALLY HISTORIC WINTER STORM IS COMING INTO
FOCUS FOR SATURDAY NIGHT INTO MONDAY MORNING. A WIDESPREAD
SWATH OF 12-18+ INCHES OF SNOW IS LOOKING MORE LIKELY ACROSS A
LARGE PORTION OF THE FORECAST AREA, ESPECIALLY BETWEEN I-90
AND I-94. STRONG WINDS SUNDAY AFTERNOON AND NIGHT COULD LEAD
TO BLIZZARD CONDITIONS AND LOCALIZED TREE AND POWER LINE
DAMAGE.
- BITTERLY COLD TEMPERATURES SETTLE IN FOR LATE SUNDAY INTO
TUESDAY BEFORE REBOUNDING LATER IN THE WEEK.
DISCUSSION
ISSUED AT 300 PM CDT THU MAR 12 2026
TONIGHT - FRIDAY MORNING: WINTER STORM #1 | DAMAGING WIND RISK
A POTENT 993-MB CLIPPER WAVE IS DIGGING ALONG THE
ND/MT/CANADIAN BORDER EARLY THIS AFTERNOON IS ON TRACK TO MOVE
INTO NORTHERN WISCONSIN TONIGHT. A 60-70-KT LLJ ALONG THE
WESTERN AND SOUTHERN FLANK OF THIS LOWER TROPOSPHERIC CYCLONE
HAS ALREADY BROUGHT 70-80 MPH WIND GUSTS TO MONTANA THIS
MORNING AND THESE WINDS SPREAD TO THE ESE THROUGH THE AFTERNOON
AND EVENING RIGHT BEHIND A STRONG COLD FRONT. PRECEDING
WAA/ISENTROPIC LIFT PRECIPITATION IS SPREADING AHEAD OF THIS
SURFACE LOW AND ARRIVES LATER THIS AFTERNOON AND PERSISTS INTO
THE OVERNIGHT. THERE WILL BE A SHARP RAIN TO SNOW GRADIENT ALONG
THE TRACK OF THE SURFACE LOW WITH SNOW AMOUNTS OF 3-6 INCHES
MOST LIKELY NORTH OF HIGHWAY 29 AND AMOUNTS FALLING OFF PRETTY
QUICKLY TO THE SOUTH.
THE COLD FRONT REACHES SOUTH-CENTRAL MINNESOTA AROUND MIDNIGHT
AND THE MISSISSIPPI RIVER BY 3AM. THE WNW WINDS INCREASE QUICKLY
IN THE WAKE OF THE FRONT WITH A STRONG CONSENSUS IN THE MODELS
THAT THE STRONG CAA AND MECHANICAL MIXING WILL STEEPEN LAPSE
RATES TO SUPPORT THE TRANSPORT OF THE 60-70-KT LLJ TO THE
SURFACE. EXPLICIT WIND GUST FORECASTS FROM THE HRRR AND RAP ARE
IN THE 45 TO 55 KT RANGE WITH WINDS AT THE TOP OF THE MIXED
LAYER NEARING 65 KTS. THE STRONGEST WINDS LOOK TO BE IN THE 3-5
HR PERIOD IMMEDIATELY FOLLOWING THE FRONTAL PASSAGE AND THEN
WE'LL SEE THE ISALLOBARIC WIND RELAX. WHILE STILL BLUSTERY,
WINDS SHOULD THEN SLOWLY DECREASE THROUGH THE REST OF THE DAY.
THE HIGH WIND WARNING HAS BEEN EXTENDED INTO SOUTHWEST WISCONSIN
WHERE THESE GUSTS UP TO 60 MPH ARE A POSSIBILITY, BUT MORE
LIMITED TO HIGHER ELEVATIONS AND EXPOSED LOCALES.
THERE IS ALSO AN INCREASING SIGNAL IN THE HIGHER RESOLUTION
GUIDANCE THAT VIGOROUS SNOW SHOWERS/HCR FEATURES WILL WRAP
AROUND THE LOW AND MOVE THROUGH DURING THE MORNING HOURS.
WHETHER THESE SHOWERS REACH THE CRITERIA FOR A SNOW SQUALL
REMAINS TO BE SEEN, BUT ANY SNOW SHOWERS WITHIN THE CORRIDOR OF
STRONGER WINDS WILL LEAD TO RAPIDLY DEGRADING VISIBILITIES OVER
SHORT DISTANCES FOR THOSE OUT DRIVING FRIDAY MORNING. FOR NOW,
THE IMPACTS FROM THESE SNOW SHOWERS IS COVERED IN THE WIND
WARNING/ADVISORY PRODUCTS, BUT SHORT-FUSED ADVISORIES OR
POSSIBLY EVEN A SNOW SQUALL WARNINGS WILL BE ASSESSED THROUGH
THE NIGHT.
SATURDAY NIGHT - MONDAY MORNING: WINTER STORM #2 | HEAVY SNOW
WHILE THE FIRST WINTER STORM TONIGHT IS RESPECTABLE ON ITS OWN,
THE SECOND STORM ON ITS HEELS SAYS "HOLD MY BEER" AND HAS THE
POTENTIAL TO DELIVER A WIDESPREAD 12 TO 18 INCHES OF SNOW WITH
LOCALIZED POCKETS OF 24 INCHES NOT OUT OF THE QUESTION IN
ADDITION TO BLIZZARD CONDITIONS. WE'VE BEEN WATCHING THIS STORM
FOR MANY DAYS AND WHILE THE SETUP IS DOWNRIGHT TEXTBOOK, THERE
REMAINS UNCERTAINTIES IN EXACTLY WHERE THE BAND OF HEAVIEST SNOW
FALLS. THE ENSEMBLE GUIDANCE HAS BEEN NARROWING IN ON OUR
FORECAST AREA FOR THE STORM TRACK, BUT WE ARE STILL 2-3 DAYS
OUT AND WE NEED TO EXPECT THAT THE STORM TRACK WILL WOBBLE.
HECK, THE CULPRIT UPPER LEVEL PV LOBE IS STILL OVER THE
NORTHEAST PACIFIC AND DOESN'T MOVE INTO THE UPPER AIR NETWORK
UNTIL TOMORROW AFTERNOON.
FROM AN INGREDIENT STANDPOINT, THE STORM IS A CLASSIC. A
RAPIDLY DEEPENING MERIDIONAL UPPER LEVEL TROUGH AND SURFACE LOW,
STRONG ISENTROPIC ASCENT AND MOISTURE TRANSPORT OVER AN
ELONGATED FGEN BAND ORIENTED ALONG THE LOW TRACK THAT PIVOTS
DIRECTLY OVER THE FORECAST AREA, UPRIGHT INSTABILITY OVER THE
FGEN ZONE THAT COULD LEAD TO THUNDERSNOW ON SUNDAY. THERE IS
STILL NOTABLE SPREAD IN THE QPF VALUES BETWEEN THE GEFS AND EPS
WITH THE GEFS MUCH MORE RAMBUNCTIOUS WITH REALIZING THE STRONG
MOISTURE TRANSPORT OVER THE FRONT AND PRODUCING A 12-18 HOUR
WINDOW OF 1"/HR SNOW RATES. IT IS INCREDIBLY DIFFICULT TO
SUSTAIN SNOW RATES THIS HIGH FOR THIS LONG AND CASTS UNCERTAINTY
INTO WHETHER THESE ARE EVEN REALISTIC. FOR REFERENCE, THE
RECORD 2-DAY SNOWFALL TOTALS FOR LA CROSSE AND ROCHESTER ARE
18.5 AND 20.1 INCHES, RESPECTIVELY. THERE ARE MANY ENSEMBLE
MEMBERS THAT ARE ECLIPSING THESE VALUES.
THERE WILL BE A SHARP CUTOFF IN SNOW AMOUNTS ALONG THE SOUTHERN
SIDE OF THE SNOW BAND AS A PRONOUNCED WARM NOSE LIFTS NORTHWARD
INTO NORTHERN IOWA AND SOUTHWESTERN WISCONSIN. AREAS THAT
REMAIN UNDER THE >+1-3C 850-MB ISOTHERM WILL SEE THEIR
PRECIPITATION VARY BETWEEN SNOW, RAIN, SLEET, AND POSSIBLY
FREEZING RAIN WITH IMPACTS AND AMOUNTS VARYING QUICKLY OVER
SHORT DISTANCES. IT WON'T BE UNTIL SUNDAY AFTERNOON/EVENING AS
THE COLD AIR ADVECTION ENSUES AND THE DEFORMATION BAND PIVOTS
SOUTHWARD THAT THE PRECIPITATION TYPE CHANGES TO SNOW OVER THE
SOUTHERN FORECAST AREA.
STRONG WINDS ON THE BACKSIDE OF THE DEPARTING LOW AND
DEFORMATION ZONE WILL LEAD TO BLOWING AND DRIFTING SNOW SUNDAY
AFTERNOON INTO MONDAY MORNING. THE WETTER NATURE OF THE SNOW
EARLY ON COMBINED WITH THE WINDS COULD RESULT IN TREE AND POWER
LINE DAMAGE AS THESE WINDS INCREASE AND TEMPERATURES BEGIN TO
FALL. THE WINTER STORM WATCH FOR WEST OF THE MISSISSIPPI RIVER
HIGHLIGHTS THE RISK FOR BLIZZARD CONDITIONS AND WE WILL HAVE TO
MONITOR TRENDS IN CASE AN EASTWARD EXPANSION OF BLIZZARD WORDING
IS NEEDED.
IT GOES WITHOUT SAYING THAT TRAVEL MAY BE IMPOSSIBLE AT TIMES
DURING THIS WINTER STORM. THE COMBINATION OF HIGH SNOW AMOUNTS
AND STRONG WINDS COULD MAKE ROADS IMPASSABLE, ESPECIALLY IN
OPEN AREAS WEST OF THE MISSISSIPPI RIVER.
EARLY NEXT WEEK: BITTERLY COLD TEMPERATURES
STRONGER CAA TRAILING OUR WEEKEND SYSTEM SENDS TEMPERATURES
PLUMMETING BACK TO VALUES MORE TYPICAL OF EARLY FEBRUARY. HIGHS
ON MONDAY ONLY REACH INTO THE TEENS WITH LOWS FOR MONDAY NIGHT
FALLING BELOW ZERO WITH A 20-30% CHANCE OF LOWS IN THE TEENS
BELOW ZERO GIVEN THE FRESH SNOW. THIS COLD SNAP LOOKS TO ONLY
LAST A FEW DAYS WITH HIGHS REBOUNDING BACK TO NEAR AVERAGE BY
THE END OF THE WEEK.
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 1154 PM CDT THU MAR 12 2026
MVFR/IFR CONDITIONS DUE TO RAIN/SNOW WITH STRONG GUSTS OUT OF
THE WEST- NORTHWEST TO 40-50 KNOTS OVER THE FIRST 6-12 HOURS OF
THE PERIOD ARE THE MAIN CONCERN FOR AVIATION INTERESTS.
OVERNIGHT, SNOW AND IFR WILL BE PREDOMINANT NORTH OF AN EAU-MFI
LINE WHILE SPOTTY RAIN/SNOW MIX AND VFR/MVFR WILL BE
PREDOMINANT ACROSS SE MN AND WEST CENTRAL WI. PRECIP SUBSIDES BY
12Z WITH SKIES SHOULD EVENTUALLY SCATTER OUT BEFORE 18Z AND
GUSTS WILL BE ON A SLOW DECREASE BEFORE DROPPING BELOW 10 KNOTS
AFTER SUNSET.
ARX WATCHES/WARNINGS/ADVISORIES
WI...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY
AFTERNOON FOR WIZ017-029-032>034-041>044-053>055-061.
WINTER STORM WARNING UNTIL 1 PM CDT FRIDAY FOR WIZ017.
WIND ADVISORY UNTIL 1 PM CDT FRIDAY FOR WIZ017-029-032>034-
041>044.
WINTER WEATHER ADVISORY UNTIL 1 PM CDT FRIDAY FOR WIZ029.
HIGH WIND WARNING UNTIL 1 PM CDT FRIDAY FOR WIZ053>055-061.
MN...HIGH WIND WARNING UNTIL 10 AM CDT FRIDAY FOR MNZ079-086>088-
094>096.
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY
AFTERNOON FOR MNZ079-086>088-094>096.
IA...HIGH WIND WARNING UNTIL 10 AM CDT FRIDAY FOR IAZ008>011-018-
019-029-030.
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY
AFTERNOON FOR IAZ008>011-018-019-029-030.
DISCUSSION...SKOW
AVIATION...FERGUSON
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