360
FXUS02 KWBC 150759
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
359 AM EDT SUN MAR 15 2026
VALID 12Z WED MAR 18 2026 - 12Z SUN MAR 22 2026
***RECORD HEAT EXPECTED ACROSS THE SOUTHWEST NEXT WEEK***
..GENERAL OVERVIEW
AN AMPLIFIED UPPER LEVEL FLOW PATTERN WILL BE IN PLACE ACROSS THE
CONTINENTAL U.S. FOR THE MIDDLE TO END OF THE WEEK, AND GRADUALLY
BECOMING LESS AMPLIFIED BY NEXT SUNDAY. A HIGHLY ANOMALOUS UPPER
RIDGE SITUATED ACROSS THE DESERT SOUTHWEST WILL DELIVER SUMMER-LIKE
HEAT TO THIS REGION WITH RECORDS EXPECTED FOR MULTIPLE DAYS, AND
WIDESPREAD WELL ABOVE AVERAGE TEMPERATURES FOR MOST AREAS WEST OF
THE MISSISSIPPI RIVER. UPPER LEVEL TROUGHING SHOULD PERSIST ACROSS
THE EASTERN U.S. WITH A NEW LOW PRESSURE SYSTEM LIKELY AFFECTING
THE GREAT LAKES AND THE NORTHEAST BY SATURDAY.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE 00Z MODEL GUIDANCE SUITE IS IN EXCELLENT OVERALL AGREEMENT ON
MOST ASPECTS OF THE FORECAST WEDNESDAY INTO THURSDAY ACROSS THE
CONTINENTAL U.S., WITH A GENERAL DETERMINISTIC AND AIFS MODEL
GUIDANCE BLEND WORKING WELL AS A STARTING POINT FOR FRONTS AND
PRESSURES. THE CMC HAS TRENDED CLOSER TO THE CONSENSUS ACROSS THE
NORTHERN TIER STATES WITH A LESS AMPLIFIED UPPER RIDGE COMPARED TO
ITS OUTLIER 12Z SOLUTION FOR THE SECOND HALF OF THE FORECAST
PERIOD, AND ALSO LESS EXTREME WITH THE TROUGH/CLOSED LOW OVER THE
NORTHEASTERN U.S. TOWARDS NEXT WEEKEND. THE GFS IS WEAKER AND MORE
ZONAL HERE COMPARED TO THE MORE DEFINED TROUGH AXIS IN THE CMC AND
ECMWF GUIDANCE. THE ENSEMBLE MEANS WERE INCREASED TO ABOUT 40% BY
NEXT SUNDAY GIVEN MORE MODEL SPREAD IN SYSTEM TIMING. THE NBM
LOOKED REASONABLE FOR THE MOST PART, BUT QPF WAS RAISED SOME ACROSS
THE NORTHEAST NEXT WEEKEND WITH THE NEXT STORM SYSTEM LIKELY
ADVECTING DEEPER MOISTURE NORTHWARD.
..WEATHER/HAZARDS HIGHLIGHTS
A MUCH COLDER AIR MASS WILL SETTLE ACROSS THE EAST COAST REGION FOR
THE MIDDLE OF THE WEEK WITH A CANADIAN SURFACE HIGH IN PLACE AFTER
THE PASSAGE OF THE STRONG COLD FRONT, WITH READINGS MORE TYPICAL
OF JANUARY INSTEAD OF MID-MARCH. THERE SHOULD BE A GRADUAL
MODERATION IN TEMPERATURES TOWARDS THE END OF THE WEEK AS THE
SURFACE MOVES OFFSHORE. RAIN AND INLAND SNOW ACROSS THE NORTHERN
MID-ATLANTIC AND THE NORTHEAST IS LIKELY TO MAKE A RETURN IN TIME
FOR NEXT WEEKEND AS THE NEXT STORM SYSTEM APPROACHES FROM THE GREAT
LAKES, ALTHOUGH UNCERTAINTIES REMAIN.
THE OPPOSITE WILL HOLD TRUE FOR A LARGE EXPANSE OF THE WESTERN
U.S. WITH A MASSIVE UPPER RIDGE BUILDING IN THROUGH THE WEEK,
PERHAPS REACHING 594DM. THIS WILL LIKELY PEAK IN INTENSITY THURSDAY
INTO FRIDAY BEFORE GRADUALLY BREAKING DOWN, WITH TEMPERATURES
INCREASING EACH DAY THROUGH THIS TIME. NUMEROUS DAILY RECORDS WILL
BE BROKEN BY THE MIDDLE TO END OF THE WEEK, AND MANY MONTHLY MARCH
RECORDS ARE ALSO LIKELY. THE RESULT WILL BE HIGHS SOARING PAST 100
DEGREES FOR THE FIRST TIME THIS SEASON (AND EARLIEST ON RECORD)
FOR THE LOWER ELEVATIONS OF SOUTHERN CALIFORNIA (AWAY FROM THE
COAST) AND ARIZONA. AS A RESULT, EXTREME HEAT WATCHES ARE ALREADY
IN EFFECT TO ACCOUNT FOR THIS AND ALSO FOR HOW EARLY IN THE SEASON
THIS IS. WIDESPREAD HEAT WILL ALSO MAKE HEADLINES ACROSS MUCH OF
THE INTERMOUNTAIN WEST AND EXPANDING EAST TO THE WESTERN HIGH
PLAINS FOR THE SECOND HALF OF THE WEEK, WITH HIGHS LIKELY TO BE
WELL INTO THE 90S ACROSS WESTERN TEXAS AND MUCH OF NEW MEXICO.
READINGS OVERALL ARE LIKELY TO BE 20-30 DEGREES ABOVE MID-MARCH
LEVELS FROM THE SOUTHWEST UP TO THE WESTERN DAKOTAS.
FOR THE PACIFIC NORTHWEST, AN ATMOSPHERIC RIVER NORTH OF THE
WASHINGTON BORDER SHOULD AFFECT THE OLYMPIC PENINSULA AND NORTHERN
CASCADES GOING INTO TUESDAY, BUT MODEST RAINFALL RATES SHOULD LIMIT
THE POTENTIAL FOR FLOODING. SHOWERS AND SOME THUNDERSTORMS WILL BE
POSSIBLE ACROSS SOUTHERN PORTIONS OF THE FLORIDA PENINSULA THROUGH
MUCH OF THE WEEK AS A STATIONARY FRONT REMAINS STALLED JUST SOUTH
OF THE STATE, AND A MARGINAL RISK AREA IS VALID FOR MAINLY
SOUTHEASTERN FLORIDA ON WEDNESDAY WITH HEAVIER RAINFALL CLOSER TO
THE COAST. OTHER PARTS OF THE COUNTRY SHOULD REMAIN UNEVENTFUL IN
TERMS OF PRECIPITATION.
HAMRICK
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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