931
FXUS02 KWBC 292005
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
405 PM EDT FRI MAY 29 2026
VALID 12Z MON JUN 01 2026 - 12Z FRI JUN 05 2026
..OVERVIEW
THE MEDIUM RANGE PERIOD, BEGINNING MONDAY, WILL FEATURE AN
AMPLIFIED PATTERN WITH A DIGGING TROUGH OVER THE EAST COAST AS WELL
AS A CLOSED MID-LEVEL LOW OVER THE ROCKIES/NORTHWEST. THE
NORTHWEST VORT MAX WILL PUSH EAST ALONG THE U.S./CANADA BORDER AS
THE WEEK PROGRESSES. THE EAST COAST TROUGH WILL BE REINFORCED BY
WAVES OF SHORTWAVE ENERGY OUT OF EASTERN CANADA THROUGH MIDWEEK
BEFORE RETREATING BACK NORTH AND OUT INTO THE NORTH ATLANTIC BY
LATE NEXT WEEK. IN BETWEEN THESE FEATURES, PLAINS UPPER RIDGING
SHOULD LEAD TO WARMER THAN AVERAGE TEMPERATURES FOR PORTIONS OF THE
INTERIOR WEST TO MIDWEST, WHILE ALLOWING FOR MOISTURE AND
INSTABILITY TO STREAM NORTHWARD AND PRODUCE MULTIPLE ROUNDS OF
CONVECTION IN THE CENTRAL U.S. THROUGHOUT THE WEEK. QUASI-ZONAL
FLOW WITH EMBEDDED SHORTWAVES LOOKS TO DEVELOP BY LATE WEEK AS THE
EARLY WEEK SYSTEMS PULL AWAY.
..GUIDANCE/PREDICTABILITY ASSESSMENT
MODELS AGREE REASONABLY WELL WITH THE OVERALL PATTERN FAVORING AN
OMEGA BLOCK EARLY NEXT WEEK, AS THE UPPER LOW PINCHES OFF IN THE
NORTHWEST WHILE TROUGHING POTENTIALLY DEVELOPING INTO AN UPPER LOW
IS IN PLACE OVER THE EAST. THE NORTHWEST LOW HAS SHOWN SOME MINOR
SPREAD IN PLACEMENT/TIMING, WHICH AFFECTS THE RESULTING SURFACE
LOW/FRONTAL SYSTEMS, BUT A MODEL AVERAGE SEEMS REASONABLE. PERHAPS
MORE SIGNIFICANT FOR MODEL DIAGNOSTICS HAS BEEN THE EASTERN U.S.
TROUGH/LOW. MULTIPLE GFS RUNS HAVE BEEN FARTHER SOUTH AND WEST OF
THE EC/CMC AND AI MODEL CONSENSUS WITH THE DEVELOPING UPPER LOW BY
MIDWEEK, YIELDING A WESTERN SURFACE LOW THAT AFFECTS NEW ENGLAND
WITH PRECIPITATION FOR LONGER. PREFER LEANING AWAY FROM THE GFS
RUNS, INCLUDING THE 12Z GFS, FOR THIS FEATURE. SHORTWAVES IN THE
NORTHERN TIER AND RIDGING IN THE SOUTH-CENTRAL TO SOUTHEASTERN U.S.
SHOWS REASONABLE AGREEMENT, WHILE A PACIFIC UPPER LOW APPROACHING
THE NORTHWEST LATE WEEK SHOWS A GOOD 12Z MODEL CONSENSUS AS WELL
(AFTER MORE SPREAD IN THE EARLY 00Z/06Z CYCLE).
A GENERAL MODEL BLEND WORKED WELL FOR THE EARLY PART OF THE
PERIOD, REDUCING THE GFS PROPORTION THROUGH THE WEEK WHILE RAISING
THE PROPORTION OF ENSEMBLE MEANS TO NEAR HALF BY THE END OF THE
FORECAST PERIOD.
..WEATHER/HAZARDS HIGHLIGHTS
THE MOST PERSISTENT SIGNAL FOR PRECIPITATION NEXT WEEK WILL BE
ACROSS THE CENTRAL U.S., WHERE MULTIPLE ROUNDS OF CONVECTION ARE
LIKELY AS MOISTURE AND INSTABILITY STREAM NORTHWARD. BY TUESDAY,
STORMS OVER PORTIONS OF THE SOUTHERN HIGH PLAINS COULD PRODUCE
ISOLATED INSTANCES OF FLASH FLOODING, YIELDING A MARGINAL RISK IN
THE DAY 5 ERO. SIMILAR AREAS WILL LIKELY BE AT RISK ON WEDNESDAY,
PERHAPS SHUNTING GRADUALLY EAST BY THURSDAY. BY MID TO LATE WEEK,
ENHANCED TROPICAL MOISTURE MAY ARRIVE INTO THE CENTRAL GULF COAST
VICINITY DESPITE NO BONA FIDE TROPICAL SYSTEM, SO THIS WILL
CONTINUE TO BE MONITORED.
ELSEWHERE, THE TROUGH/UPPER LOW OVER THE INTERMOUNTAIN WEST WILL
LEAD TO SOME LINGERING RAIN OVER THE NORTHERN ROCKIES/HIGH PLAINS
INTO EARLY NEXT WEEK. MEANWHILE FRONTAL SYSTEMS PUSHING THROUGH THE
SOUTHEASTERN QUADRANT OF THE U.S. COULD ALLOW FOR CONVECTION TO
SPARK ON MONDAY, CLEARING IN MANY AREAS EXCEPT FLORIDA AS THE
FRONT(S) PUSH THROUGH. SOME RAIN IS POSSIBLE IN THE NORTHEAST IN
THE EARLY HALF OF THE WEEK UNDER THE INFLUENCE OF THE UPPER
TROUGH/LOW.
TEMPERATURE-WISE, EXPECT WARMER THAN AVERAGE CONDITIONS FOR THE
NORTH-CENTRAL U.S. FOR MULTIPLE DAYS UNDER RIDGY FLOW. ABOVE
AVERAGE CONDITIONS ALONG THE WEST COAST EARLY NEXT WEEK SHOULD
SHIFT INTO THE INTERIOR WEST MIDWEEK AND BEYOND. TEMPERATURES
SHOULD BE WELL INTO THE 100S INTO THE DESERT SOUTHWEST, A FEW
DEGREES ABOVE NORMAL. NEAR TO COOLER THAN NORMAL TEMPERATURES ARE
POSSIBLE FOR THE EAST UNDER THE TROUGH, WARMING LATE WEEK.
TATE/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, EXCESSIVE RAINFALL OUTLOOK,
WINTER WEATHER OUTLOOK PROBABILITIES, HEAT INDICES AND KEY MESSAGES
ARE AT:
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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