244
FXUS02 KWBC 080700
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
300 AM EDT THU AUG 8 2024
VALID 12Z SUN AUG 11 2024 - 12Z THU AUG 15 2024
...EXCESSIVE HEAT LINGERS OVER PORTIONS OF TEXAS AND THE CENTRAL
GULF COAST INTO NEXT WEEK...
..OVERVIEW
THE UPPER LOW THAT TRACKS JUST NORTH OF THE GREAT LAKES AND IS
RESPONSIBLE FOR PUSHING DEBBY REMNANTS OUT OF THE NORTHEAST BY
SATURDAY MORNING LINGERS OVER THE NORTHEAST AS A TROUGH INTO
TUESDAY. THIS WILL MAINTAIN A COOLER/DRIER AIR MASS TO MUCH OF THE
NORTHEAST/MID-ATLANTIC THROUGH EARLY NEXT WEEK. UPSTREAM OVER THE
WEST AND CENTRAL STATES, UPPER RIDGING CENTERED OVER TEXAS WILL
MAINTAIN MONSOONAL FLOW OVER THE SOUTHWEST/SOUTHERN ROCKIES INTO
THE MIDDLE OF NEXT WEEK WITH HEAT CONCERNS PERSISTING FROM TEXAS
TO THE CENTRAL GULF COAST. MINOR/MAINLY DRY TROUGHING OVER THE
PACIFIC NORTHWEST WILL LINGER THROUGH THE PERIOD.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE 18Z GFS AND 12Z ECMWF/CMC/UKMET HAD GOOD AGREEMENT FOR DAYS 3-5
WITH THE NORTHEAST AND NORTHWEST TROUGHING AND SOUTH-CENTRAL
RIDGING. FOR DAYS 6/7 THE 12Z ECENS/18Z GEFS MEANS WERE INCLUDED
FOR THE MIDWEEK PATTERN. FOR QPF THE 01Z NBM WAS DIRECTLY BLENDED
WITH THE 12Z ECMWF/CMC WITH SOME 18Z GFS IN TARGETED AREAS
INCLUDING THE SOUTHERN PLAINS WHERE THERE IS A HEAVY RAIN THREAT ON
DAYS 4/5.
..WEATHER/HAZARDS HIGHLIGHTS
MONSOONAL MOISTURE FLOW ON THE WESTERN SIDE OF THE RIDGE CENTERED
OVER TEXAS WILL KEEP A WET AND UNSETTLED PATTERN IN PLACE FROM THE
FOUR CORNERS REGION NORTHWARD INTO THE CENTRAL ROCKIES/HIGH PLAINS
FOR SUNDAY/MONDAY. MARGINAL EROS ARE IN PLACE HERE FOR DAYS 4/5.
WITH THE SURFACE HIGH SHIFTING EAST TO THE MIDWEST ON SUNDAY, THE
CLOCKWISE FLOW OPENS THE WESTERN GULF TO EJECT MOISTURE UP THE
PLAINS IN A BIT OF A DISJOINTED MANNER WITH THE ROCKIES ON SUNDAY,
THAT THEN CONNECTS ACROSS THE HIGH PLAINS ON MONDAY, SO A SEPARATE
MARGINAL RISK EXTENDS FROM SOUTH DAKOTA DOWN THE EASTERN SIDE OF
THE PLAINS THROUGH THE OZARKS ON DAY 4. THE CONNECTED MARGINAL ON
DAY 5 EXTENDS EAST TO THE MID-SOUTH. CONVECTIVE PROCESSES THAT ARE
NOT HANDLED WELL IN GLOBAL MODELS WILL LIKELY CAUSE FURTHER
ADJUSTMENT TO THESE AREAS WITH POSSIBLE UPGRADES IN THE COMING
DAYS, SO STAY TUNED.
FINALLY, A PERSISTENT FRONT OVER THE SOUTHEAST/CAROLINAS LOOKS TO
PRODUCE WIDESPREAD RAIN WITH EMBEDDED HEAVIER RAIN WHERE RECENT
EXCESSIVE RAINFALL FROM DEBBY HAS RESULTED IN FULLY SATURATED
SOILS THAT MAY ONLY PARTIALLY RECOVER BY THEN. MARGINAL RISKS ARE
IN EFFECT IN THIS PART OF THE SOUTHEAST FOR DAYS 4/5.
ABOVE SEASONAL NORMAL TEMPERATURES PERSIST OVER TEXAS TO THE
CENTRAL GULF COAST INTO NEXT WEEK DOWN STREAM OF A RIDGE AXIS OVER
WEST TEXAS. HEATRISK VALUES WILL BE AT MODERATE TO MAJOR LEVELS
WITH SOME ISOLATED EXTREME VALUES. BELOW NORMAL TEMPERATURES OVER
THE CENTRAL U.S. PERSISTS BEHIND A COLD FRONT INTO MONDAY BEFORE
RETURN FLOW BRINGS TEMPS BACK TOWARD NORMAL.
JACKSON
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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