108
FXUS02 KWBC 131748
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
148 PM EDT MON APR 13 2026
VALID 12Z THU APR 16 2026 - 12Z MON APR 20 2026
...HOT ACROSS THE EAST COAST AND MORE HEAVY RAIN AND THUNDERSTORMS
FOR THE PLAINS AND MIDWEST TO CLOSE OUT THE WORK WEEK...
..GENERAL OVERVIEW
AN ANOMALOUS UPPER LEVEL RIDGE WILL BE IN PLACE ACROSS THE EASTERN
U.S. FOR THE END OF THE WEEK, ACCOMPANIED BY RECORD BREAKING
TEMPERATURES IN MANY PLACES FROM THE CAROLINAS TO THE MID-ATLANTIC.
A LEAD SHORTWAVE CROSSING THE OHIO VALLEY AND THE NORTHEAST WILL
PUT A DENT IN THIS RIDGE, FOLLOWED BY A MUCH STRONGER TROUGH/COLD
FRONT BY SUNDAY THAT WILL BRING THE EARLY SEASON HEATWAVE TO AN
END. THIS SAME STORM SYSTEM WILL LIKELY GENERATE MULTIPLE ROUNDS OF
HEAVY RAIN AND STRONG TO SEVERE THUNDERSTORMS ACROSS THE PLAINS AND
MIDWEST, FOLLOWED BY A RETURN TO MUCH COOLER WEATHER. A NEW STORM
SYSTEM FROM THE PACIFIC IS LIKELY TO AFFECT THE WEST COAST REGION
BY SUNDAY INTO MONDAY WITH RENEWED PROSPECTS FOR RAIN AND MOUNTAIN
SNOW ACROSS MUCH OF THE REGION.
..GUIDANCE/PREDICTABILITY ASSESSMENT
OVERALL DECENT MODEL AGREEMENT OF THE AMPLIFIED UPPER-LEVEL TROUGH
OVER WESTERN U.S. GRADUALLY MOVING EASTWARD THROUGH THE EARLIER
PORTION OF THE PERIOD. AS WE HEAD INTO THE WEEKEND, DETERMINISTIC
MODELS START TO DIVERGE AND SHOW AN INCREASE IN RUN-TO-RUN
VARIABILITY ON THE SHORTWAVE ENERGY EJECTING FROM THE WEST. THE
MOST NOTICEABLE OUTLIER WILL BE THE GFS, AS IT SHOWS A FASTER
PROGRESSION OF THE LARGE-SCALE FEATURES, ESPECIALLY FOR THE LOW
PRESSURE SYSTEM EVOLVING OFF THE PACIFIC NORTHWEST ON SUNDAY. LATER
IN THE PERIOD, MODELS SPREAD INCREASES EVEN FURTHER, WHICH MADE
FINE-TUNING DIFFICULT. THEREFORE, THE LATTER PORTION OF THE
FORECAST INCORPORATED MUCH MORE OF THE MODEL MEANS. IN ADDITION,
THE NBM SEEMED TO UNDER-PERFORM ON TEMPERATURES OVER THE
SOUTHEAST/MID- ATLANTIC THROUGH SUNDAY.
..WEATHER/HAZARDS HIGHLIGHTS
THE LEAD SHORTWAVE TROUGH CROSSING THE OHIO VALLEY ON THURSDAY IS
EXPECTED TO BE ACCOMPANIED BY A WEAKENING BAND OF SHOWERS AND
THUNDERSTORMS FROM THE MID-SOUTH TO THE OHIO VALLEY. MOST OF THE
GUIDANCE DOES NOT CURRENTLY SHOW ANYTHING ALL THAT CONCERNING FROM
A FLOOD POTENTIAL PERSPECTIVE, AND THEREFORE THE DAY 4/THURSDAY
EXCESSIVE RAINFALL OUTLOOK REMAINS VOID OF ANY RISK AREAS, ALTHOUGH
THIS COULD CHANGE IN THE DAYS AHEAD AS THE SMALLER SCALE DETAILS OF
ANY CONCENTRATED THUNDERSTORM ACTIVITY BECOMES MORE IN FOCUS. THE
LARGER SCALE TROUGH AND FRONT APPROACHING THE MIDWEST ON DAY
5/FRIDAY WILL HAVE ENOUGH DYNAMICS AND INSTABILITY TO SUPPORT MORE
WIDESPREAD CONVECTIVE COVERAGE AND HEAVY RAINFALL FROM EASTERN
KANSAS TO THE GREATER CHICAGO METRO AREA, AND THEREFORE A MARGINAL
RISK AREA WILL BE VALID HERE FOR FRIDAY.
WINTER WEATHER WILL CONTINUE TO MAKE WEATHER HEADLINES ACROSS THE
HIGHER TERRAIN OF THE WESTERN U.S. IN TWO DISTINCT ROUNDS. THE
AMPLIFYING TROUGH OVER THE NORTHERN ROCKIES WILL SUPPORT MODERATE
TO HEAVY SNOW FROM NORTHERN UTAH/COLORADO NORTHWARD TO THE IDAHO
AND MONTANA ROCKIES THURSDAY, WITH UP TO A FOOT OF SNOW LIKELY FOR
THE HIGHER RANGES. THERE WILL BE A BREAK IN THE ACTION UNTIL LATE
SATURDAY WHEN THE NEXT STORM SYSTEM ARRIVES IN THE PACIFIC
NORTHWEST. THIS IS FORECAST TO PRODUCE HEAVY SNOW FOR THE CASCADES
AND EXTENDING TO THE NORTHERN SIERRA BY MONDAY MORNING, AND SHOWERS
FOR THE LOWER ELEVATIONS AND NEAR THE COAST.
THE ANOMALOUS AND RECORD BREAKING APRIL HEATWAVE WILL STILL BE
ONGOING GOING INTO THE START OF THIS FORECAST PERIOD THURSDAY FROM
THE PLAINS TO THE EAST COAST, WITH THE GREATEST ANOMALIES EXPECTED
FROM VIRGINIA TO GEORGIA. WIDESPREAD LOWER TO EVEN MIDDLE 90S ARE
EXPECTED THURSDAY, WHICH WOULD SET NUMEROUS DAILY RECORDS AND
PERHAPS COME CLOSE TO SOME MONTHLY RECORDS. THIS ALSO HOLDS TRUE
GOING INTO FRIDAY AND SATURDAY AS WELL, ALTHOUGH NORTHERN PORTIONS
OF THE MID-ATLANTIC MAY GET A MODEST COOLING TREND WITH A WEAK
FRONTAL BOUNDARY DROPPING SOUTH. RELIEF COMES BY SUNDAY AS A STRONG
COLD FRONT STEADILY MAKES ITS WAY TO THE EAST COAST, WITH THE
HOTTEST CONDITIONS MAINLY CONFINED TO THE PIEDMONT AND COASTAL
PLAIN OF VIRGINIA AND THE CAROLINAS, AND THEN PLEASANTLY COOLER BY
MONDAY WITH THE FRONT EXITING THE COAST.
OUDIT/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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