385
FXUS02 KWBC 120634
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
234 AM EDT THU MAR 12 2026
VALID 12Z SUN MAR 15 2026 - 12Z THU MAR 19 2026
...RECORD WARMTH ACROSS CALIFORNIA AND THE SOUTHWEST THIS WEEKEND
INTO NEXT WEEK...
...STRONG STORM TO BRING HEAVY SNOW AND HIGH WINDS FOR THE UPPER
MIDWEST/GREAT LAKES...
..OVERVIEW
THE MEDIUM RANGE PERIOD WILL TREND QUITE AMPLIFIED THIS WEEKEND
AND INTO NEXT WEEK. A SHORTWAVE DIGGING INTO THE NORTH-CENTRAL U.S.
ON SUNDAY WILL SPIN UP A REASONABLY STRONG SURFACE LOW IN THE
CENTRAL U.S., TRACKING INTO THE GREAT LAKES ON MONDAY. HEAVY SNOW
AND STRONG WINDS ARE INCREASINGLY LIKELY SUNDAY-MONDAY FROM THE
UPPER MIDWEST INTO THE UPPER GREAT LAKES. GUSTY WINDS AND MODEST
RAINFALL WILL ACCOMPANY THE COLD FRONT THROUGH THE EAST AS WELL.
MEANWHILE, A ROBUST AND STRONG UPPER-LEVEL RIDGE CENTERED OVER THE
SOUTHWEST AND GREAT BASIN WILL PROMOTE UNSEASONABLY WARM TO RECORD-
BREAKING TEMPERATURES ACROSS CALIFORNIA TO THE SOUTHWEST AND
EVENTUALLY INTO PARTS OF THE INTERMOUNTAIN WEST.
..GUIDANCE/PREDICTABILITY ASSESSMENT
MODEL GUIDANCE CONTINUES TO SHOW GOOD AGREEMENT ON THE LARGE SCALE
PATTERN EVOLUTION FEATURING AN AMPLIFIED TROUGH OVER THE EAST AND
STRONG RIDGING OVER THE WEST. MODELS ARE CONTINUING TO TREND CLOSER
ON THE TRACK OF THE STRONG LOW FROM THE CENTRAL U.S. TO THE GREAT
LAKES WITH MINIMAL SPREAD AT THIS POINT. SOME SPREAD IN THE TIMING
OF HOW QUICKLY THE TROUGH AXIS MAY CLEAR THE EAST COAST AT THE END
OF THE PERIOD/NEXT THURSDAY, WITH THE CMC ALSO SUGGESTING A SLIGHT
BREAK DOWN OF THE WESTERN RIDGE A BIT EARLIER. WITH REASONABLE
MODEL AGREEMENT, WPCS FORECAST FOR TONIGHT LEANED HEAVILY ON THE
DETERMINISTIC MODELS THROUGH DAY 5, INCREASING THE ENSEMBLE MEAN
WEIGHTING TO 50-60 PERCENT OF THE BLEND BY DAY 7 TO HELP MITIGATE
SOME OF THE SMALLER SCALE VARIANCES IN THE DETERMINISTIC GUIDANCE.
..WEATHER/HAZARDS HIGHLIGHTS
A STORM SYSTEM MOVING INTO THE CENTRAL U.S. ON SUNDAY WILL SPIN UP
INTO A REASONABLY STRONG SURFACE LOW OVER THE GREAT LAKES BY
MONDAY. THIS WILL BRING A HEAVY SNOW AND STRONG WIND THREAT FROM
THE UPPER MIDWEST AND UPPER GREAT LAKES SUNDAY INTO MONDAY, WITH
INCREASING CONFIDENCE IN BLIZZARD OR NEAR- BLIZZARD CONDITIONS IN
SOME LOCATIONS. THE HEAVIEST SNOW TOTALS (POTENTIALLY ONE TO TWO
FEET) ARE CURRENTLY MOST LIKELY ACROSS PORTIONS OF WISCONSIN AND
MICHIGAN. A CORRIDOR OF FREEZING RAIN IS ALSO POSSIBLE JUST SOUTH
OF THE SNOW. RAIN WITH THIS SYSTEM AHEAD OF THE COLD FRONT SHOULD
STAY FAIRLY MODEST ACROSS THE SOUTHEAST, THOUGH MAY BECOME LOCALLY
HEAVY IN THE NORTHEAST BY MONDAY. A MARGINAL RISK IS HIGHLIGHTED ON
THE DAY 5/MONDAY EXCESSIVE RAINFALL OUTLOOK IN THIS REGION. GUSTY
WINDS MAY ACCOMPANY THIS SYSTEM AS IT TRACKS THROUGH THE EAST. SOME
LAKE EFFECT SNOW IS POSSIBLE DOWNWIND OF THE GREAT LAKES BEHIND
THIS SYSTEM AS WELL.
MEANWHILE, A COUPLE OF SHORTWAVES SHOULD KEEP THE PACIFIC
NORTHWEST SOMEWHAT WET THROUGH THE PERIOD. SUNDAY INTO MONDAY MAY
SEE THE HEAVIEST PRECIPITATION FOR THE OLYMPICS AND CASCADES AS A
MODERATE ATMOSPHERIC RIVER COMES THROUGH, BUT HOLDING OFF ON ANY
ERO AREAS DUE TO UNCERTAINTIES IN HOW FAR SOUTH RAIN WILL OCCUR,
SNOW LEVELS, AND RAINFALL RATES. MODERATE TO HEAVY SNOW IS POSSIBLE
IN THE HIGHER ELEVATIONS OF THE NORTHWEST INLAND INTO THE ROCKIES.
ELSEWHERE, SOME LIGHT RAIN AND SNOW MAY SPREAD ACROSS THE NORTH-
CENTRAL U.S. BY MONDAY INTO TUESDAY WITH A SHORTWAVE IMPULSE.
HEAT FROM THE SOUTHWEST TO THE CENTRAL GREAT BASIN WILL BUILD
THROUGH THE PERIOD, WITH WIDESPREAD RECORD BREAKING VALUES
POSSIBLE. MODERATE TO LOCALIZED MAJOR HEATRISK IS FORECAST ACROSS
PARTS OF SOUTHERN CALIFORNIA INTO THE DESERT SOUTHWEST AS
TEMPERATURES APPROACH OR EXCEED 100 DEGREES IN SOME PLACES. OVER
THE WEEKEND, ABOVE NORMAL TEMPERATURES WILL OVERSPREAD THE SOUTH AS
WELL, WITH SOME RECORDS POSSIBLE INTO THE SOUTHERN PLAINS, AND
ANOTHER BRIEF WARMUP FOR THE MIDWEST AND THE EAST SUNDAY INTO
MONDAY. THIS WILL BE SHORT LIVED THOUGH, AS THE AMPLIFYING TROUGH
EARLY NEXT WEEK WILL BRING WITH IT BELOW NORMAL TEMPERATURES.
DAYTIME HIGHS ARE FORECAST TO BE 10 TO 20 DEGREES BELOW AVERAGE BY
NEXT MONDAY AND TUESDAY OVER THE NORTHERN/CENTRAL PLAINS INTO THE
MIDWEST, AND CHILLY MORNING LOWS MAY LEAD TO FROST/FREEZE CONCERNS
IN THE SOUTHEAST.
SANTORELLI
ADDITIONAL 3-7 DAY HAZARD INFORMATION CAN BE FOUND ON THE WPC
MEDIUM RANGE HAZARDS OUTLOOK CHART AT:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
WPC MEDIUM RANGE 500MB HEIGHTS, SURFACE SYSTEMS, WEATHER GRIDS,
QUANTITATIVE PRECIPITATION FORECAST (QPF), EXCESSIVE RAINFALL
OUTLOOK (ERO), WINTER WEATHER OUTLOOK (WWO) PROBABILITIES, HEAT
INDICES, AND KEY MESSAGES CAN BE ACCESSED FROM:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST500_WBG.GIF
HTTPS://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST_WBG_CONUS.GIF
HTTPS://WWW.WPC.NCEP.NOAA.GOV/5KM_GRIDS/5KM_GRIDSBODY.HTML
HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/DAY4-7.SHTML
HTTPS://WWW.WPC.NCEP.NOAA.GOV/#PAGE=ERO
HTTPS://WWW.WPC.NCEP.NOAA.GOV/WWD/PWPF_D47/PWPF_MEDR.PHP?DAY=4
HTTPS://WWW.WPC.NCEP.NOAA.GOV/HEAT_INDEX.SHTML
HTTPS://WWW.WPC.NCEP.NOAA.GOV/#PAGE=OVW
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