386
FXUS02 KWBC 260724
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
324 AM EDT TUE AUG 26 2025
VALID 12Z FRI AUG 29 2025 - 12Z TUE SEP 02 2025
..OVERVIEW
TROUGHING OVER THE EAST WILL GENERALLY HOLD THROUGH MUCH OF THE
MEDIUM RANGE PERIOD WITH BLOCKY RIDGING OVER THE INTERIOR WEST.
ENERGY DOWN THE WEST SIDE OF THE TROUGH WILL INTERACT WITH FRONTAL
BOUNDARIES AT THE SURFACE TO BRING A HEAVY RAIN THREAT TO PORTIONS
OF THE GREAT PLAINS LATER THIS WEEK. THE PATTERN BECOMES MORE
UNCERTAIN THIS WEEKEND AND EARLY NEXT WEEK BUT SHOWERS AND
THUNDERSTORMS, WITH LOCALLY HEAVY RAINFALL, SHOULD CONTINUE TO
FOCUS ACROSS THE SOUTHERN TIER.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE LATEST GUIDANCE HAS TRENDED CLOSER TO A EURO-CENTRIC SOLUTION
REGARDING THE SYNOPTIC EVOLUTION OVER THE LOWER 48 DURING THE
MEDIUM RANGE PERIOD. A GENERAL MODEL BLEND WAS USEFUL FOR DAYS 4
AND 5 WITH SKEWED WEIGHTING TOWARD EQUAL PARTS EURO AND GFS. THE
EURO SUITE CONSISTING OF THE DETERMINISTIC AND ENSEMBLE MEAN WERE
FAVORED THROUGH THE REST OF THE PERIOD, DUE TO THEIR FAIRLY DECENT
CLUSTERING WITH A MAJORITY OF THE MACHINE LEARNING MODELS AS WELL
AS TOO MUCH DISPERSION SEEN IN THE GEFS AND RUN-TO-RUN
INCONSISTENCY IN THE GFS.
THERE'S GROWING CONFIDENCE IN A HEAVY RAIN THREAT OVER PORTIONS OF
THE CENTRAL/SOUTHERN PLAINS ON DAYS 4 AND 5. ALL OF THE DETERMINISTIC
QPF HAVE TRENDED WETTER ON DAY 5, IN PARTICULAR. A QPF SIGNAL IN
THE EUROPEAN EFI SUPPORTS THIS THREAT. THERE'S UNCERTAINTY ON A
HEAVY RAIN THREAT OVER PARTS OF THE NORTHERN/CENTRAL PLAINS ON DAY
5.
..WEATHER/HAZARDS HIGHLIGHTS
A STATIONARY FRONT DRAPED ACROSS THE HIGH PLAINS WILL BE THE FOCUS
FOR THUNDERSTORMS THIS FRIDAY AND SATURDAY. A MARGINAL RISK (AT
LEAST 5% CHANCE) IS IN EFFECT FROM GREAT PLAINS DOWN AND ACROSS THE
GULF COAST AND SOUTHEAST ON FRIDAY AND SATURDAY. ON SATURDAY, A
SLIGHT RISK (AT LEAST 15% CHANCE) OF EXCESSIVE RAINFALL WAS
INTRODUCED OVER PARTS OF THE TEXAS/OKLAHOMA PANHANDLE INTO EASTERN
NEW MEXICO TO ACCOUNT FOR A GROWING MODEL SIGNAL FOR MULTIPLE
ROUNDS OF CONVECTION OVER THAT AREA BETWEEN FRIDAY AND SATURDAY.
ELSEWHERE, THE DOWNSTREAM SECTION OF THE FRONT WILL PROMOTE
ADDITIONAL THUNDERSTORM ACTIVITY ACROSS THE GULF COAST THIS
WEEKEND. A CONVERGENCE AXIS BENEATH A WEAK DISTURBANCE ALOFT COULD
REFOCUS MONSOON MOISTURE OVER MUCH OF NEW MEXICO AND THE FOUR
CORNERS REGION LATER THIS WEEKEND AND INTO NEXT WEEK.
SURFACE HIGH PRESSURE FROM CANADA WILL DESCEND OVER MUCH OF THE
EASTERN U.S. THIS WEEK. THIS WILL BRING A COOL AND DRY CONTINENTAL
AIRMASS TO THE MIDWEST AND EAST COAST. CLOUDY AND STORMY
CONDITIONS OVER THE PLAINS WILL LIKELY CONTRIBUTE TO WELL BELOW
AVERAGE TEMPERATURES BEGINNING THURSDAY.
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 (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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