516
FXUS02 KWBC 220722
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
322 AM EDT THU AUG 22 2024
VALID 12Z SUN AUG 25 2024 - 12Z THU AUG 29 2024
..OVERVIEW
THE ONGOING BLOCKY FLOW PATTTERN OVER THE COUNTRY IS EXPECTED TO
INCREASINGLY TRANSITION INTO EARLY NEXT WEEK. THIS IS AS AMPLE
EASTERN PACIFIC UPPER TROUGH ENERGY FINALLY LIFTS IN EARNEST INLAND
ACROSS THE WEST AND INTO CANADA AS QUITE A WARMING UPPER RIDGING
THAT HAS BEEN ANCHORED OVER THE SOUTH-CENTRAL U.S. ELONGATES OVER
THE EAST-CENTRAL U.S.. THIS TEMPORARILY EASES MONSOONAL FLOW INTO
THE SOUTHWEST BEFORE AN EXPECTED OVERALL MODEST MID-LATER PERIOD
RETURN. WELL TO THE NORTH, PATTERN EVOLUTION WILL LEAD TO
OPPORTUNITIES FOR MORE PROGRESSIVE AND ENERGETIC NORTHERN STREAM
UPPER TROUGH ENERGY AND COOLING AIRMASSES TO WORK INTO THE WEST AND
DOWNSTREAM OVER THE U.S. NORTHERN TIER STATES MID-LATER NEXT WEEK.
..GUIDANCE/PREDICTABILITY ASSESSMENT
MODELS AND ENSEMBLE SOLUTIONS CONTINUE TO PROVIDE LESS THAN STELLAR
MODEL TO MODEL AND RUN TO RUN EMBEDDED SYSTEM TIMING VARIANCES
THROUGH MEDIUM RANGE TIME SCALES, BUT FORECAST SPREAD HAS OVERALL
DECREASED VERSUS THE PAST FEW DAYS. ACCORDINGLY, THE WPC MEDIUM
RANGE PRODUCT SUITE WAS PRIMARILY DERIVED FROM A MODEL AND ENSEMBLE
BLEND WITH ENHANCED WEIGHTING APPLIED TO SOLUTIONS ON THE SLIGHTLY
LESS PROGRESSIVE SIDE OF THE FULL ENVELOPE OF GUIDANCE GIVEN
RECENT FLOW NATURE, BUT THE RESULT IS NOT AS SLOWED AS CONTINUITY.
..WEATHER/HAZARDS HIGHLIGHTS
AMPLIFIED UPPER TROUGHING WILL FINALLY EJECT INLAND OVER THE
WEST/NORTHWEST THIS WEEKEND AND PROVIDE A PERIOD WITH COOLED AND
UNSETTLED CONDITIONS. THIS MAY INCLUDE RAINS AND SPOTTY HIGH
ELEVATION MOUNTAIN SNOWS ACROSS THE NORTHERN INTERMOUNTAIN
WEST/ROCKIES. RAINS/CONVECTION MAY ALSO DEVELOP DOWNSTREAM OVER
THE NORTH-CENTRAL U.S. EARLY NEXT WEEK GIVEN FOCUS FROM POSSIBLE
MODERATE CYCLOGENESIS/FRONTOGENESIS, WITH MODEST FOCUS SHIFTING
DOWNSTREAM AS THE WEEK PROGRESSES WITH SYSTEM/FRONTAL TRANSLATION.
RENEWED NORTHERN STREAM UPPER TROUGH APPRAOCH AND DIGGING BACK INTO
THE NORTHWEST INTO MID-LATER NEXT WEEK OFFERS POTENTIAL FOR
DEVELOPMENT AND DIGGING/INTRUSION OF UNSETTLED AND COOLED FLOW.
UPPER RIDGING BUILDING FROM THE SOUTH-CENTRAL U.S. THROUGH THE
EAST-CENTRAL U.S. WILL ALLOW SUMMERTIME TEMPERATURES TO SPREAD
ACROSS THESE REGIONS TO INCLUDE VALUES UPWARDS OF 10 DEGREES ABOVE
NORMAL. HEAT RISK GUIDANCE IDENTIFIES AN ASSOCIATED REGION WITH
UPWARDS TO MAJOR LEVEL IMPACTS WITH MAIN FOCUS SET TO SHIFT SLOWLY
FROM THE SOUTH-CENTRAL PLAINS AND MID-MISSISSIPPI VALLEY SUNDAY
SOUTHEASTWARD THROUGH THE SOUTH-SOUTHEAST INTO NEXT MIDWEEK.
A LINGERING TRAILING FRONT STALLING ACROSS FLORIDA WILL MAINTAIN
PERIODIC RAIN/THUNDERSTORM CHANCES THERE AND INTO SOUTHEAST U.S.
COASTAL AREAS INTO NEXT WEEK. MOIST FLOW AND PATTERN LONGEVITY MAY
LEAD TO POSSIBLE LOCAL RUNOFF ISSUES, ESPECIALLY FOR URBAN AREAS.
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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