601
FXUS02 KWNH 190832
PREEPD
PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
431 AM EDT THU MAR 19 2026
VALID 12Z SUN MAR 22 2026 - 12Z THU MAR 26 2026
...ANOMALOUS EARLY SEASON HEAT WAVE ABATING SOMEWHAT EARLY NEXT
WEEK BUT APPEARS TO REBUILD MIDWEEK...
..OVERVIEW
THE MEDIUM-RANGE FORECAST PERIOD SHOULD FEATURE AN ANOMALOUS UPPER
HIGH HOVERING NEAR THE SOUTHWESTERN BORDER OF THE U.S. WHILE BRIEF
RIDGING EARLY NEXT WEEK IN THE EASTERN U.S. WILL BE REPLACED BY
BROAD TROUGHING MIDWEEK. IN THE WEST, STRONGER RIDGING APPEARS TO
BE THE CURRENT MODEL TREND EARLY NEXT WEEK BEFORE SIGNIFICANT
TROUGHING REACHES THE PACIFIC NORTHWEST AND ADVANCES FARTHER
SOUTHEAST INTO THE WESTERN U.S. FROM MIDWEEK ONWARD.
..GUIDANCE/PREDICTABILITY ASSESSMENT
WITHIN THE GENERAL THEME OF AN ANOMALOUS UPPER HIGH OVER THE
SOUTHWEST AND BROAD TROUGHING IN THE EAST, DETERMINISTIC SOLUTIONS
FROM THE GLOBAL MODELS HAVE BEEN EJECTING WAVES TOO FAST EASTWARD
FROM THE ROCKIES TOWARD THE EASTERN U.S. CASE IN POINT IS THE
FRONTAL WAVE ACROSS THE CENTRAL U.S. ON SUNDAY. ALL GLOBAL MODELS
INCLUDING THE AI OUTPUTS FROM PREVIOUS DAYS HAVE BEEN EJECTING
THIS WAVE WAY TOO FAST TO THE EAST. THE LATEST MODEL GUIDANCE HAS
BEEN TRENDING TOWARD MORE RIDGING IN THE GREAT PLAINS THIS WEEKEND.
THE DOWNSTREAM IMPLICATION IS FOR THE WARM FRONT TO BE FARTHER
NORTH, TOGETHER WITH WARMER CONDITIONS OVER THE EASTERN U.S. AND
SLOWER EJECTION OF THE LOW PRESSURE WAVE ACROSS THE NORTHEAST ON
MONDAY. IT APPEARS THAT ALL DETERMINISTIC MODELS INCLUDING THE AIS
OFFER SKILLFUL GUIDANCE FROM ABOUT DAY 5 ONWARD FOR THE EASTERN
TWO-THIRDS OF THE COUNTRY EXCLUDING THE SOUTHERN TIER STATES.
ACROSS THE WEST, STRONGER RIDGING APPEARS TO BE THE CURRENT MODEL
TREND EARLY NEXT WEEK BEFORE SIGNIFICANT TROUGHING REACHES THE
PACIFIC NORTHWEST AND ADVANCES FARTHER SOUTHEAST INTO THE WESTERN
U.S. FROM MIDWEEK ONWARD. THE STRONGER RIDGE ADVERTISED BY THE EC
MEAN FROM THE SOUTHWEST TO THE ROCKIES APPEARS TO BE A VIABLE
SOLUTION BECAUSE BOTH THE GEFS AND CMC MEANS ARE TRENDING TOWARD A
STRONGER RIDGE BUT LAGGING BEHIND THE EC MEAN SOLUTION.
GIVEN THE UNCERTAINTY NOTED ABOVE, THE BEST COURSE OF ACTION IS TO
USE THE CONSENSUS OF THE LATEST ENSEMBLE MEANS FROM THE GEFS,
ECMWF, AND CMC MEAN. THE NBM'S QPF WAS CLOSER TO THE GEFS MEAN FOR
THE WAVE CROSSING THE NORTHEAST SUNDAY-MONDAY, WHICH IS THE
PREFERRED SOLUTION ASSUMING A SLOWER WAVE SPEED COMPARED WITH THE
EC MEAN WHICH CONTAINS SOLUTIONS WITH A MORE SOUTHERN TRACK ACROSS
THE APPALACHIANS.
..WEATHER/HAZARDS HIGHLIGHTS
THE MEDIUM-RANGE FORECAST PERIOD WILL BEGIN ON SUNDAY WITH THE
RECORD-BREAKING EARLY SEASON HEATWAVE IN THE WESTERN U.S. ABATING
A BIT DUE TO COLD AIR INTRUDING INTO THE NORTHERN AND CENTRAL
PLAINS. THEREAFTER, MORE WIDESPREAD HIGH TEMPERATURES 20 TO 30+
DEGREES ABOVE NORMAL APPEAR TO RETURN OVER THE WESTERN U.S. ON
WEDNESDAY AS A RATHER STRONG COLD FRONT PENETRATES INLAND THROUGH
MUCH OF THE WESTERN U.S. AND INTO THE NORTHERN PLAINS BY AROUND
THURSDAY. NUMEROUS RECORD HIGH TEMPERATURES WILL LIKELY BE BROKEN
ONCE AGAIN ACROSS THE SOUTHWEST FOLLOWED BY THE SOUTHERN PLAINS.
ACROSS THE CENTRAL PLAINS TO THE MIDWEST, RECENT MODEL TRENDS ARE
INDICATING STRONGER RIDGING ACROSS THE SOUTHERN PLAINS ON SUNDAY.
THIS TRANSLATES TO A STRONGER AND FARTHER NORTHWARD PLACEMENT OF
THE WARM FRONT ACROSS THE MIDWEST AND A STRONGER SURGE OF THE COLD
AIR DOWN THE NORTHERN AND CENTRAL PLAINS.
WINTRY PRECIPITATION COULD AFFECT NEW ENGLAND PARTICULARLY THE
INTERIOR SECTIONS WITH THE PASSAGE OF THE LOW PRESSURE WAVE, WITH
THE MODELS TRENDING TOWARD A SLOWER EJECTION OF THE WAVE. THIS
WOULD KEEP A WINTRY MIX FARTHER INLAND AND RAIN FARTHER SOUTH
ACROSS THE MID-ATLANTIC ALTHOUGH THE DETAILS ARE FAR FROM CERTAIN.
THERE WILL LIKELY BE A BRIEF WARM-UP FOR THE EAST COAST REGION THIS
WEEKEND AHEAD OF THE STRONG COLD FRONT, WITH HIGHS EXPECTED TO BE
WELL INTO THE 60S AND 70S FOR MANY AREAS. HIGHS SHOULD RETURN TO
SLIGHTLY BELOW NORMAL LEVELS BY MONDAY AND TUESDAY AS A CANADIAN
SURFACE HIGH BUILDS IN FROM THE NORTH.
ACROSS THE PACIFIC NORTHWEST, WITH THE APPROACH OF A DEEP UPPER
TROUGH EARLY NEXT WEEK, A RETURN OF RAIN AND MOUNTAIN SNOW IS
LIKELY, WITH TUESDAY TO WEDNESDAY BEING THE TIME PERIOD OF
RECEIVING THE HEAVIEST PRECIPITATION. THE SUNSHINE STATE COULD
SEE SOME SHOWERS AND THUNDERSTORMS LINGER NEAR THE EAST COAST DUE
TO THE COLD FRONT BECOMING STATIONARY IN THE VICINITY.
KONG
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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