255
FXUS02 KWBC 191900
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
300 PM EDT THU MAR 19 2026
VALID 12Z SUN MAR 22 2026 - 12Z THU MAR 26 2026
...ANOMALOUS EARLY SEASON HEAT WAVE ACROSS THE SOUTHWEST ABATING
SOMEWHAT EARLY NEXT WEEK BUT MAY 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
GUIDANCE GENERALLY SHOWS GOOD AGREEMENT ON THE LARGE SCALE PATTERN
EVOLUTION OVER THE CONUS THROUGH THE PERIOD, BUT NOTABLE
DIFFERENCES IN THE DETAILS. THERE REMAIN SOME TIMING UNCERTAINTIES
WITH A SHORTWAVE/SURFACE LOW PRESSURE SYSTEM MOVING FROM THE
MIDWEST TO THE NORTHEAST, WITH THE 06Z GFS A BIT STRONGER/WEST WITH
THE SYSTEM RESULTING IN MUCH HIGHER SNOW TOTALS ACROSS THE
INTERIOR NORTHEAST. BY NEXT WEEK, DETERMINISTIC GUIDANCE CONTINUES
TO TREND TOWARDS STRONGER RIDGING OVER THE WEST, WHICH IS IN
AGREEMENT WITH THE ENSEMBLE MEANS. AGAIN, THE 06Z GFS WAS
FLATTER/WEAKER WITH THIS RIDGING AS A RESULT OF FASTER/STRONGER
TROUGHING MOVING INTO THE NORTHWEST LATER IN THE PERIOD.
FOR THE WPC 500MB AND SURFACE PROGS, WAS ABLE TO USE A BLEND OF
THE DETERMINISTIC GUIDANCE THE FIRST HALF OF THE PERIOD. INCREASED
THE WEIGHTING OF THE ENSEMBLE MEANS TO 60 PERCENT OF THE BLEND BY
THE END OF THE PERIOD TO MITIGATE THE SMALLER SCALE DETAIL
DIFFERENCES. DID NOT INCLUDE THE GFS AT ALL IN THE BLEND DUE TO
ISSUES DESCRIBED ABOVE. GENERALLY, THIS APPROACH MAINTAINED GOOD
CONTINUITY WITH THE PREVIOUS WPC FORECAST.
..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 BEFORE 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 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 ON
SUNDAY, 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. FLORIDA COULD SEE SOME
SHOWERS AND THUNDERSTORMS LINGER NEAR THE EAST COAST DUE TO THE
COLD FRONT BECOMING STATIONARY IN THE VICINITY.
SANTORELLI/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
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page