607
FOUS11 KWBC 150801
QPFHSD
PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
401 AM EDT SUN MAR 15 2026
VALID 12Z SUN MAR 15 2026 - 12Z WED MAR 18 2026
..NORTHERN HIGH PLAINS THROUGH THE GREAT LAKES
DAYS 1-3...
...BLIZZARD EXPECTED THIS WEEKEND WITH WIDESPREAD MAJOR IMPACTS
AND RECORD-BREAKING SNOWFALL FOR PORTIONS OF THE UPPER MIDWEST AND
GREAT LAKES...
CONFIDENCE CONTINUES TO BE HIGH FOR A WIDESPREAD MAJOR WINTER
STORM ACROSS THE UPPER MIDWEST AND GREAT LAKES AS A LEE SURFACE
LOW LIFTS NORTHEAST AND RAPIDLY DEEPENS INTO AN INCREASINGLY MOIST
COLUMN. SNOWFALL FROM MINNESOTA THROUGH WISCONSIN AND NORTHERN
MICHIGAN, INCLUDING THE U.P, WILL BREACH 12" IN MANY LOCATIONS WITH
AREAS OF NORTHERN WI INTO THE U.P. LIKELY TO EXCEED 24" BY THE
STORMS CLOSURE.
CURRENT WV SATELLITE AND UA ANALYSIS INDICATES A MATURING SYNOPTIC
EVOLUTION WITH A DIGGING SHORTWAVE ACROSS WY AND AN ATTENDANT
SURFACE LOW CURRENTLY ANALYZED OVER THE WESTERN HIGH PLAINS OF
KANSAS. AS THE SHORTWAVE TROUGH DIGS FURTHER TO THE SOUTHEAST, FLOW
WILL BECOME INCREASINGLY MERIDIONAL OVER THE CENTRAL PLAINS TO
MISSISSIPPI VALLEY WITH THE TROUGH AXIS FORECAST TO TILT NEUTRAL
TO EVENTUALLY NEGATIVE WITH THE 5H HEIGHT PATTERN EXPECTED TO CLOSE
OFF NEAR OR OVER IA BY LATER THIS EVENING. SURFACE LOW WILL TREK
NORTHEAST OVER THE COURSE OF SUNDAY, INTENSIFYING SLOWLY AS IT
MIGRATES TOWARDS THE SOUTHERN EDGE OF LAKE MICHIGAN BY NIGHTFALL.
AS THE UPPER PATTERN CLOSES OFF AND TAKES ON THE NEGATIVE TROUGH
ORIENTATION, SURFACE LOW WILL RAPIDLY INTENSIFYING AS IT BEGINS TO
ENTER INTO ITS FULL MATURATION PHASE AS THE PRIMARY HEIGHTS FROM
850MB TO 500MB BECOME MORE VERTICALLY STACKED INTO MONDAY MORNING.
THE CYCLONE WILL FINALLY REACH OCCLUSION PHASE BY MONDAY AFTERNOON,
BUT SURFACE LOW PRESSURE WILL LIKELY BE DOWN INTO THE UPPER 970S BY
THIS JUNCTURE OVER THE WESTERN GREAT LAKES, SOLIDIFYING ITS
PRESENCE WITH AN ALL-OUT BLIZZARD FOR A LARGE CHUNK OF THE MIDWEST
AND GREAT LAKES REGION. MOISTURE CONVERGENCE OCCURRING DURING THE
STORMS LIFE CYCLE EMANATING FROM THE DECAYING AR PUSHING EAST, AND
A BUDDING THETA-E RIDGE ARCING NORTHWARD ON INTENSIFYING
WAA/SOUTHERLY FLOW OUT OF THE GULF WILL HELP PROVIDE SUBSTANTIAL
DEEP LAYER MOISTURE POLEWARD, AS FAR NORTH AS THE WESTERN ONTARIO
PROVINCE IN CANADA, A TESTAMENT TO THE OVERALL FORTITUDE OF THIS
DISTURBANCE. THE OVERLAP OF ROBUST DEEP LAYER ASCENT WITH
MAXIMIZING MOISTURE RETURN WILL DEEPEN THE LOW SUBSTANTIALLY, AND
AID IN THE EXPANSION OF A CONSIDERABLE PRECIPITATION SHIELD, WITH
HEAVY SNOW ARCING FROM SD THROUGH THE GREAT LAKES ALREADY AS OF THE
PRE-DAWN HOURS SUNDAY. PRECIP FIELD WILL SLOWLY PIVOT NORTHEAST
WHILE CONTINUING THROUGH D2 AS THE SURFACE LOW MOVES INTO ONTARIO
BY 00Z/TUESDAY.
LITTLE CHANGE IN THE RELEVANT SYNOPTIC DETAILS REFERENCED IN THE
LAST FORECAST AS GUIDANCE REMAINS STEADFAST IN ALL FACETS OF THIS
STORMS ANTICIPATED EVOLUTION. THE SYNOPTIC SETUP IS EXTREMELY
FAVORABLE FOR A CLASSIC MIDWEST WINTER STORM WITH WIDESPREAD
INTENSE SNOWFALL. EMBEDDED BANDS WITH SNOWFALL RATES OF 1-3"/HR ARE
EXPECTED AS REFLECTED BY HIGH POTENTIAL FOR CSI AND EVEN CI IN
MODEL CROSS- SECTIONS SUNDAY AFTN INTO MONDAY WHICH DRIVES INTENSE
OMEGA INTO THE TROWAL. THERE REMAINS HIGH CONFIDENCE IN A LATERALLY
TRANSLATING BAND OF HEAVY SNOW FROM SD INTO MN SUNDAY MORNING,
WITH THE ENVIRONMENT TRANSITING INTO ONE THAT MATCHES THE
CONCEPTUAL MODEL FOR A PIVOTING BAND OVER EASTERN MN AND
WI/MICHIGAN U.P. SUNDAY EVENING INTO MONDAY. IT IS IN THIS AREA
WHERE THE HEAVIEST SNOWFALL IS EXPECTED, AND POTENTIALLY RECORD, OR
NEAR- RECORD 2-DAY SNOWFALL IS POSSIBLE FROM EASTERN MN THROUGH WI
AND NORTHERN MI. ELSEWHERE, SNOWFALL RATES OF 1"/HR OR MORE ARE
STILL LIKELY AT TIMES, JUST WITH LESSER DURATION. THESE SNOWFALL
RATES COMBINED WITH GUSTY WINDS REACHING UP TO 60 MPH WILL CREATE
BLIZZARD AND NEAR-BLIZZARD CONDITIONS AND WHITEOUTS, WITH MAJOR TO
EXTREME IMPACTS PROGGED BY THE RECENT WSSI-P. EVEN IN AREAS THAT
GET LOWER SNOW TOTALS, THE BLOWING SNOW POTENTIAL WILL STILL RESULT
IN DIFFICULT TRAVEL, AND IT IS LIKELY THAT MOST FORMS OF
TRANSPORTATION WILL BE TREACHEROUS AT BEST, AND IMPOSSIBLE AT
WORST, THROUGH THE EVENT ACROSS A LARGE AREA FROM MONTANA TO
MICHIGAN, AND EVERYWHERE IN BETWEEN.
EVENT-TOTAL SNOWFALL IS LIKELY TO BE EXTREME IN SOME AREAS. THIS IS
REFLECTED BY 72-HR WPC PROBABILITIES (ENDING 12Z TUESDAY) THAT ARE
HIGH (>70%) FOR AT LEAST 12" FROM SOUTHEAST MN TO POINTS NORTHEAST
THROUGH NORTH- CENTRAL WI, AND THE ENTIRETY OF THE U.P. OF MI.
WHERE SNOWFALL IS MOST PROLIFIC, LIKELY IN NORTHEASTERN WI AND THE
U.P OF MI, WPC PROBABILITIES INDICATE A 70-90+% CHANCE OF AT LEAST
24", AND LOCALIZED TOTALS OF 3-4 FEET ARE POSSIBLE BEFORE THIS
EVENT ENDS WITH THE MAXIMA POSITIONED ACROSS THE HURON MOUNTAINS
DOWNWIND OF LAKE SUPERIOR. THIS COULD RESULT IN RECORD SNOWFALL IN
SOME PLACES, AND WITH SLRS BEING NEAR TO SLIGHTLY BELOW CLIMO,
COMBINED WITH THE STRONG WINDS, POWER OUTAGES AND LONG- LASTING
IMPACTS ARE EXPECTED. FOR THESE REASONS, WINTER STORM KEY MESSAGES
ARE IN EFFECT, AND ARE LINKED BELOW (KEY MESSAGE 1).
AFTER 00Z TUESDAY, SNOWFALL RATES WILL BE WANING RAPIDLY IN DIRECT
ASSOCIATION WITH THE STORM, TRANSITIONING MORE AND MORE TO LAKE-
EFFECT SNOWS DOWNWIND OF ALL OF THE LAKES. PRONOUNCED CAA ON NW
FLOW IN ITS WAKE COULD RESULT IN SOME LAKE EFFECT SNOW IN THE
FAVORED NW SNOW BELTS DOWNSTREAM OF ALL THE GREAT LAKES. WPC
PROBABILITIES ARE MODERATE (50%) FOR AT LEAST 4" OF SNOW FROM LES
IN SW MI, AS WELL AS ALONG THE CHAUTAUQUA RIDGE AND INTO THE TUG
HILL PLATEAU. ADDITIONAL HEAVY SNOW WILL OCCUR NEAR MARQUETTE, MI
AS WELL, ADDING ONTO THE EXTREME SNOWFALL EVENT THERE THE NEXT FEW
DAYS BRING STORM AND LES COMBINATION TOTALS TOWARDS THE 4-5FT RANGE
BY TUESDAY AFTERNOON. THE LAKE- EFFECT WILL CONTINUE INTO TUESDAY
MORNING BEFORE LARGELY DISSIPATING.
ON THE S/SE SIDE OF THIS SNOWFALL SWATH, AN AXIS OF MIXED
PRECIPITATION IS LIKELY, LEADING TO ICING ACCRETION FROM CENTRAL IA
THROUGH SOUTHERN WI AND INTO THE NORTHERN MIT IN LOWER MI. THE
MOST SIGNIFICANT ICING IS EXPECTED FOR THE NORTHERN MIT OF MI
WHERE WPC PROBABILITIES FOR AT LEAST 0.25" OF ICE HAVE SETTLED
BETWEEN 40-70%, AND THE AXIS OF HIGHER PROBABILITIES FOR AT LEAST
0.10" OF ICE HAVE EXTENDED BACK INTO SOUTHERN WI.
..CENTRAL APPALACHIANS
POWERFUL CYCLONE OVER THE GREAT LAKES WILL PROVIDE A STRONG COLD
FRONT TRAILING THE PRIMARY SURFACE LOW AS IT MIGRATES EASTWARD
THROUGH MUCH OF THE COUNTRY EAST OF THE MISSISSIPPI. ONCE THE COLD
FRONT ADVANCES BEYOND THE APPALACHIAN FRONT, STRONG COLD AIR
ADVECTION (CAA) REGIME WILL TRANSPIRE WITH RAIN CHANGING TO SNOW
FOR THE MOUNTAINS OF WESTERN PA DOWN THROUGH WESTERN MD AND THE
ADJACENT WV HIGHLANDS. ELEVATIONS >2000FT WILL SEE SOME SNOWFALL
WITH THE GREATEST ACCUMS FOCUSED OVER AREAS >2500FT, A GENERAL
CLIMO OUTPUT FOR THIS TYPE OF EVOLUTION. WPC PROBABILITIES FOR >4"
OF SNOWFALL ARE BETWEEN 20-40% FOR THE ENTIRE APPALACHIAN CHAIN OF
WESTERN PA DOWN THROUGH WV. MAXIMA OF 40-60% IS LOCATED OVER THE
CANAAN VALLEY DOWN INTO SNOWSHOE, WV WHERE SOME DETERMINISTIC
OUTPUT ARE PRINTING OUT UPWARDS OF 6-8" OF HIGH RATIO SNOWFALL
POST-FROPA. SETUP AND MAGNITUDE OF THE UPSLOPE FLOW IS CLASSIC FOR
THIS SCENARIO ALLOWING FOR GROWING CONFIDENCE IN AT LEAST MINOR
IMPACTS FOR THE TERRAIN OF THE MID ATLANTIC.
WEISS/KLEEBAUER
...WINTER STORM KEY MESSAGES ARE IN EFFECT. PLEASE SEE CURRENT
KEY MESSAGES BELOW...
HTTPS://WWW.WPC.NCEP.NOAA.GOV/KEY_MESSAGES/LATESTKEYMESSAGE_1.PNG
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