332
FXUS02 KWBC 041804
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
204 PM EDT SAT APR 4 2026
VALID 12Z TUE APR 07 2026 - 12Z SAT APR 11 2026
..PATTERN OVERVIEW
SPLIT FLOW OVER THE LOWER 48 NEXT WEEK WILL BE HIGHLIGHTED BY TWO
MAIN STREAMS. IN A STEADILY PROGRESSIVE NORTHERN STREAM, A LEADING
UPPER TROUGH OVER THE NORTHERN THIRD OF THE NATION TUESDAY WILL
QUICKLY EXIT AS AN ENERGETIC UPSTREAM UPPER TROUGH PROGRESSES ON
IT'S HEELS FROM THE NORTHWEST U.S. TUESDAY TO THE NORTHEAST INTO
THURSDAY/FRIDAY. THESE WILL REINFORCE A WAVY FRONTAL BOUNDARY OVER
THE GULF AND FLORIDA TO PROLONG A WET PATTERN. MEANWHILE, AN
EASTERN PACIFIC SOUTHERN STREAM CLOSED UPPER TROUGH AND SYSTEM
ENERGY WILL SLOWLY WORK INLAND TO THE WEST/SOUTHWEST WITH SOME
SHOWERS BY FRIDAY/SATURDAY. AMPLE LEAD RETURN FLOW DEVELOPMENT THEN
OVER THE CENTRAL U.S. MAY PORTEND A RE-EMERGING HEAVY RAINFALL
PATTERN BY NEXT WEEKEND THAT HAS SOME SIGNAL EVIDENT BEYOND THAT
INTO WEEK 2 AS PER THE CLIMATE PREDICTION CENTER (CPC) THAT MAY
OFFER BROAD MODERATE AND HIGH RISK POTENTIAL TO MONITOR.
..GUIDANCE/PREDICTABILITY ASSESSMENT
LATEST MODEL AND ENSEMBLE GUIDANCE CONTINUES TO SHOW GOOD
AGREEMENT ON THE LARGE SCALE PATTERN ACROSS THE CONUS NEXT WEEK,
BUT WITH LINGERING UNCERTAINTY IN THE DETAILS AND TIMING OF
SYSTEMS. THERE ARE SOME MINOR TIMING DIFFERENCES WITH THE NORTHERN
STREAM SHORTWAVE WHICH DRIVES A DECENT SURFACE SYSTEM ACROSS THE
NORTHERN ROCKIES/PLAINS AND UPPER MIDWEST/GREAT LAKES MIDWEEK.
AFTER THIS, UNCERTAINTY REMAINS INITIALLY WITH THE TIMING OF THE
SOUTHERN STREAM UPPER LOW OFF THE WEST COAST, AND THEN HOW MUCH OF
THE LOW OPENS UP AS IT ENTERS THE SOUTHWEST NEXT WEEKEND OR STAYS
INTACT. THE BETTER CONSENSUS SUGGESTS THE UPPER LOW SHOULD MORE OR
LESS STAY IN TACT/SEPARATE FROM THE NORTHERN STREAM, BUT THE GFS
WAS MUCH MORE SHEARED WITH THIS, LIKELY IN RESPONSE TO A
STRONGER/MORE SOUTHWARD POSITIONED UPPER LOW OFF THE NORTHWEST
COAST.
THE LATEST WPC GUIDANCE BLEND FOR THE UPPER LEVEL AND SURFACE
PROGS WAS PRIMARILY DERIVED FROM A BLEND OF THE DETERMINISTIC
GUIDANCE FOR THE FIRST HALF OF THE PERIOD. INCREASED WEIGHTING OF
THE ENSEMBLE MEANS DAYS 6 AND 7 TO 60 PERCENT OF THE BLEND TO HELP
MITIGATE THE UNRESOLVABLE ASPECTS OF THE FORECAST IN THE WEST LATE
PERIOD. THIS MAINTAINS GOOD CONTINUITY WITH PRIOR WPC GUIDANCE AND
IS CONSISTENT WITH THE NBM.
..WEATHER/HAZARDS HIGHLIGHTS
A WAVY FRONT IS FORECAST TO SETTLE OFFSHORE INTO THE ATLANTIC AND
GULF NEXT WEEK, THOUGH IT WILL STILL BE PASSING OVER FLORIDA AND
PROVIDE A FOCUS FOR ABOVE AVERAGE MOISTURE THERE AND POSSIBLY INTO
GULF COASTAL AREAS. CONSISTENT WITH WPC DAY 3-7 HAZARDS PRODUCTS,
THE WPC EXCESSIVE RAINFALL OUTLOOK SHOWS MARGINAL RISK AREAS ON DAY
4/TUESDAY AND DAY 5/WEDNESDAY FOR EASTERN COASTAL FLORIDA. A WET
PATTERN SHOULD PERSIST GIVEN SOUTHERN STREAM TROUGH ENERGY MAY BE
REINFORCED INTO LATER PERIOD WITH FLOW AMPLIFICATION.
FARTHER NORTH, THE NORTHEAST UPPER TROUGH WILL ALLOW FOR SOME
LINGERING LOWER LAKE EFFECT PRECIPITATION WITH A ROUND OF RAIN AND
SNOW PASSING OVER THE NORTHEAST TUESDAY. ANOTHER SWATH OF
PRECIPITATION IS POSSIBLE IN THE NORTH-CENTRAL PLAINS TO MID-UPPER
MISSISSIPPI VALLEY. MEANWHILE, SOME CONVECTION IS POSSIBLE IN THE
FOUR CORNERS REGION INTO TUESDAY WITH SOME SOUTHERN STREAM WAVES
ALOFT AND ABOVE AVERAGE MOISTURE. THEN AS AN UPPER LOW/TROUGH MOVES
TOWARD AND INTO THE WEST, LIFT AND POOLED MOISTURE SHOULD SUPPORT
SOME ORGANIZED PRECIPITATION WEDNESDAY INTO LATER NEXT WEEK,
INCLUDING HIGHER ELEVATION SNOW. THE SIGNAL IS INCREASING FOR
RETURN FLOW AHEAD OF THE WESTERN TROUGH TO SPREAD WIDESPREAD
MODERATE TO HEAVY PRECIPITATION INTO THE PLAINS AND MIDWEST LATER
NEXT WEEK. THIS MAY CONTINUE INTO WEEK 2 AS WELL PER LATEST
PRODUCTS FROM CPC.
FOLLOWING COLD FRONT PASSAGES AND COOLED CANADIAN HIGH PRESSURE
SETTLING NEXT WEEK, THE CENTRAL TO EASTERN U.S. SHOULD SEE PERIODS
WITH BELOW AVERAGE TEMPERATURES. THE WEST CAN EXPECT ABOVE AVERAGE
TEMPERATURES BY 10 TO 20 DEGREES UNDERNEATH UPPER RIDGING FOR THE
EARLY PART OF THE WEEK. ABOVE NORMAL PRE-FRONTAL TEMPERATURES
SHOULD SPREAD INTO THE HIGH PLAINS BY TUESDAY AND GRADUALLY FARTHER
SOUTHEAST LATER NEXT WEEK AS THE RIDGE SHIFTS EAST, WHILE THE WEST
COAST CAN EXPECT TEMPERATURES TO COOL AS UPPER TROUGHING AND
ASSOCIATED FRONTAL SYSTEMS WORK SLOWLY INLAND.
SANTORELLI/SCHICHTEL
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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