791
FXUS02 KWNH 200834
PREEPD
PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
433 AM EDT FRI MAR 20 2026
VALID 12Z MON MAR 23 2026 - 12Z FRI MAR 27 2026
...ANOMALOUS EARLY SEASON HEAT WAVE ACROSS THE SOUTHWEST ABATING
SOMEWHAT EARLY NEXT WEEK BUT MAY REBUILD MIDWEEK...
..OVERVIEW
THE MEDIUM RANGE PERIOD WILL FEATURE AN ACTIVE NORTHERN STREAM,
SUPPLIED BY A CLOSED GULF OF ALASKA LOW SHEDDING LOBES OF SHORTWAVE
VORTICITY ACROSS DOWNSTREAM PORTIONS OF SOUTHERN CANADA/NORTHERN
CONUS. THESE TRANSIENT WAVES WILL OCCASIONALLY ERODE RIDGING IN THE
NORTHWEST AND GENERATE PRECIPITATION. MEANWHILE, THE PREDOMINANT
WESTERN RIDGE WILL REMAIN LOCKED IN OVER THE SOUTHWEST WHILE
GRADUALLY EXPANDING INTO THE SOUTHEAST BY MID-WEEK.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE LATEST GUIDANCE IS IN REASONABLY GOOD AGREEMENT REGARDING THE
EVOLUTION OF THE RIDGE ACROSS THE SOUTHERN U.S. NEXT WEEK.
UNCERTAINTY EXISTS WITH RESPECT TO THE TIMING AND AMPLITUDE OF THE
SHORTWAVES PROPAGATING THROUGH THE NORTHERN TIER OF THE U.S.. A
GENERAL MODEL BLEND CONSISTING OF THE NON UKMET DETERMINISTIC
GUIDANCE WAS USED IN THE DAY 3 BLEND. A NON-EURO SUITE BLEND WAS
FAVORED THROUGH THE END OF THE PERIOD DUE, IN PART, TO RUN-TO-RUN
INCONSISTENCIES, SOME ENSEMBLE SPREAD IN THE ECE, AND A DIVERGENCE
FROM THE CMC/GFS SUITE CONSENSUS REGARDING THE NORTHERN STREAM
EVOLUTION.
..WEATHER/HAZARDS HIGHLIGHTS
THE MAIN STORY DURING THE MEDIUM RANGE PERIOD WILL BE THE
ANOMALOUS,AND POTENTIALLY, RECORD BREAKING HEATWAVE IN THE WEST. A
PROMINENT UPPER-LEVEL RIDGE WILL SUPPORT MAXIMUM TEMPERATURES THAT
ARE 20-40 DEGREES ABOVE AVERAGE FROM THE SOUTHWEST TO GREAT
PLAINS. WIDESPREAD MAXIMUM AND MINIMUM TEMPERATURE RECORDS ARE
EXPECTED FROM THE SOUTHWEST EARLY NEXT WEEK TO THE CENTRAL U.S. BY
MIDWEEK. THIS HEATWAVE, COMBINED WITH DRY CONDITIONS, WILL
CONTRIBUTE TO FIRE WEATHER CONCERNS OVER PORTIONS OF THE NORTHERN
HIGH PLAINS, CENTRAL ROCKIES AND SOUTHERN PLAINS EARLY NEXT WEEK. A
CRITICAL THREAT (70% CHANCE) OF STRONG WINDS, LOW RELATIVE
HUMIDITY AND WARM TEMPERATURES WILL BE IN PLACE OVER THE
AFOREMENTIONED AREAS.
A POTENT MID-LATITUDE CYCLONE WILL MOVE FROM THE NORTHWEST TO THE
CANADIAN MARITIME NEXT WEEK. THIS SYSTEM WILL BRING MODERATE TO
HEAVY RAIN OVER THE PACIFIC NORTHWEST TUESDAY. MOST OF THE
PRECIPITATION FROM THIS WILL BE IN THE FORM OR RAIN SINCE THE
SHORTWAVE ALOFT WILL BE EMBEDDED WITHIN THE BROADER WESTERN RIDGE.
HIGHER ELEVATIONS OF THE OLYMPIC AND CASCADE MOUNTAINS WILL
RECEIVE SOME SNOWFALL, ESPECIALLY ON THE BACKSIDE OF THE ASSOCIATED
COLD FRONT. THE LOW PRESSURE SYSTEM WILL WEAKEN WHILE IT TRACKS
ACROSS THE CENTRAL U.S., BEFORE REINVIGORATING OVER THE EAST AND
PRODUCING SOME RAIN/SNOW FOR PARTS OF THE GREAT LAKES AND NORTHEAST
BY LATE NEXT WEEK.
KEBEDE
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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