249
FXUS02 KWBC 290823
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
423 AM 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 IN THE EAST COAST AS WELL
AS A CLOSED MID-LEVEL LOW OVER THE ROCKIES/NORTHWEST. THE NORTHWEST
VORT MAX WILL SLIP NORTH INTO SOUTHERN CANADA BEFORE PROPAGATING
INTO THE CANADIAN MARITIME BY LATE NEXT WEEK. THE EAST COAST TROUGH
WILL BE REINFORCED BY WAVES OF SHORTWAVE ENERGY OUT OF EASTERN
CANADA BEFORE QUICKLY RETREATING BACK NORTH AND OUT INTO THE NORTH
ATLANTIC BY LATE NEXT WEEK. ZONAL FLOW DEVELOPS ACROSS THE NORTHERN
TIER OF THE CONUS ON THE BACKSIDE OF THE DEPARTING ROCKIES/WESTERN
U.S. LOW.
..GUIDANCE/PREDICTABILITY ASSESSMENT
MODELS ARE IN REASONABLY GOOD AGREEMENT REGARDING THE EVOLUTION OF
THE WESTERN U.S. PATTERN, WHILE NOTABLY DIVERGING ON THE EASTERN
U.S. TROUGH EVOLUTION. IN THE EAST, THE GFS DEVELOPS A DEEP CUT OFF
LOW OVER THE MID-ATLANTIC BY MID-WEEK AND HAS IT SLOWLY MOVE OUT TO
SEA WHILE THE EURO IS NOTABLY WEAKER AND MORE PROGRESSIVE, AND THE
CANADIAN IS MUCH SLOWER AND WEAKER THAN BOTH.
A GENERAL MODEL BLEND CONSISTING OF THE AVAILABLE DETERMINISTIC AND
AI GUIDANCE WERE USED IN THE DAY 3 BLEND WITH EQUAL WEIGHTING
ACROSS THE BOARD. THE VARIANCE ALONG THE EAST COAST IS THE GREATEST
ON DAY 4 WHERE THE DETERMINISTIC EURO GFS AND CANADIAN ALL HAVE
DIFFERENT SOLUTIONS. A COMPOSITE OF ALL 3 WAS USED TO FIND AN
AVERAGE. THE ENSEMBLE MEANS MAKE UP A MAJORITY OF THE BLEND
BEGINNING ON DAY 5 DUE TO THE DEVELOPING ZONAL FLOW AND UNCERTAINTY
IN THE WESTERN ATLANTIC.
..WEATHER/HAZARDS HIGHLIGHTS
TROUGHING OVER THE INTERMOUNTAIN WEST ABOVE A DECAYING LOW
PRESSURE SYSTEM WILL PROMOTE SCATTERED SHOWERS AND THUNDERSTORM
ACTIVITY ACROSS THE CENTRAL U.S. NEXT WEEK. SOME STORMS OVER
PORTIONS OF THE SOUTHERN HIGH PLAINS COULD PRODUCE ISOLATED
INSTANCES OF FLASH FLOODING NEXT TUESDAY, WHICH IS REFLECTED IN OUR
DAY 4 MARGINAL RISK (AT LEAST 5% CHANCE) OF EXCESSIVE RAINFALL.
WARM AND HUMID AIR WILL CONTINUE TO SURGE NORTH THROUGHOUT THESE
AREAS, LEADING TO MUGGY CONDITIONS THROUGH MID-WEEK WHEN CONDITIONS
BEGIN TO IMPROVE A BIT AS WARM AIR SHIFTS INTO THE EASTERN U.S..
TROUGHING OVER THE EAST WILL SUPPORT SLIGHTLY BELOW AVERAGE
TEMPERATURES UNTIL MID-WEEK WHEN THE AFOREMENTIONED SEASONAL AIR
BEGINS TO WORK ITS WAY BACK INTO THE REGION. ELSEWHERE,
TEMPERATURES REMAIN AROUND AVERAGE. A PLUME OF TROPICAL MOISTURE
MAY IMPACT PORTIONS OF THE GULF COAST LATE NEXT WEEK, BUT THERE'S
STILL PLENTY OF UNCERTAINTY REGARDING WHERE EXACTLY THE MAXIMUM QPF
FOOTPRINT WILL ORGANIZE AT THIS TIME.
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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