931
FXUS02 KWNH 200801
PREEPD
PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
400 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 THE 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 NEXT
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 PARTO 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 SOMETIMES, RECORD BREAKING HEATWAVE IN THE WEST. A
PROMINANT UPPER LEVEL RIDGE WILL SUPPORT
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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