271
FXUS02 KWBC 241927
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
327 PM EDT THU JUL 24 2025
VALID 12Z SUN JUL 27 2025 - 12Z THU JUL 31 2025
...MAJOR AND PERSISTENT HEAT WAVE CONTINUES ACROSS THE MID-SOUTH
AND SOUTHEAST THROUGH THE MIDDLE OF NEXT WEEK...
..GENERAL OVERVIEW
A MAJOR HEATWAVE CONTINUES FOR MUCH OF THE CENTRAL/SOUTHEAST SUNDAY
BEFORE SHRINKING TO THE SOUTHERN TIER/SOUTHEAST THROUGH THE MIDDLE
OF NEXT WEEK. A SPRAWLING UPPER RIDGE CENTERED OVER THE MID-SOUTH
REACHES PEAK SPRAWL ON MONDAY BEFORE SUPPRESSION/COOLER
TEMPERATURES FROM A HUDSON BAY LOW BRINGS HEAT RELIEF FOR THE
NORTHERN TIER STATES THROUGH MIDWEEK. COMPLEXES OF SHOWERS AND
STORMS ARE LIKELY ALONG THE NORTHERN PERIPHERY OF THE RIDGE OVER
THE NORTHERN PLAINS TO UPPER MIDWEST ON SUNDAY TO THE CENTRAL
PLAINS AND MIDWEST BY TUESDAY MIDWEST, AND MONSOONAL MOISTURE MAKES
A RETURN TO THE SOUTHWEST STATES. THE RIDGE AXIS SHIFTS WEST AND
BUILDS NORTH ACROSS THE ROCKIES INTO WESTERN CANADA STARTING
TUESDAY.
..GUIDANCE/PREDICTABILITY ASSESSMENT
EXCELLENT OVERALL MODEL AGREEMENT REMAINS AMONG GLOBAL GUIDANCE
SUITE REGARDING THE SOUTHERN UPPER RIDGE AND THE HUDSON BAY LOW
INTO THE MIDDLE OF NEXT WEEK. THE SURFACE FORECAST WAS BASED ON THE
00Z/06Z GLOBAL MODELS THROUGH DAY 5 WITH SOME ENSEMBLE MEANS FOR
DAYS 6/7 AFTER THE UKMET DROPS OUT. THE GFS REMAINS A LITTLE MORE
PROGRESSIVE WITH AN IMPULSE ROUNDING THE RIDGE ON SUNDAY WHICH PUTS
MORE QPF OVER WISCONSIN THAN MINNESOTA WHERE THE CONSENSUS QPF
PLACEMENT IS. HOWEVER, BY EARLY NEXT WEEK, THE DOMINANCE OF THE
RIDGE ALLOWS FOR MORE AGREEMENT AMONG GUIDANCE WITH THE SOUTHERN
SHIFT OF ACTIVITY DOWN THE PLAINS AND GREAT LAKES STILL ALLOWING A
GENERAL MODEL BLEND TO BE PREFERRED OVERALL.
..WEATHER/HAZARDS HIGHLIGHTS
ACTIVE WEATHER/HEAVY RAINFALL POTENTIAL SHIFTS SOUTH SUNDAY THROUGH
THE MIDDLE OF NEXT WEEK AS THE SPRAWLING RIDGE SUPPRESSES FROM THE
NORTH. THE DAY 4 SLIGHT RISK REMAINS FOR MUCH OF NORTHERN MINNESOTA
INTO NORTHWEST WISCONSIN THOUGH MESOSCALE PROCESSES WILL TAKE OVER,
SO THIS AREA SHOULD SHIFT THOUGH THE INGREDIENTS OF HIGH MOISTURE
AND INSTABILITY WARRANT THE SLIGHT RISK. SUPPRESSION OF THE RIDGE
IS LOOKING MORE PROGRESSIVE, SO THE DAY 5 MARGINAL RISK THAT SPANS
THE NORTH-CENTRAL PLAINS WAS EXPANDED SOUTH A BIT INTO NORTHERN
IOWA.
DEEPER MONSOONAL MOISTURE OVER THE DESERT SOUTHWEST WARRANTS
MAINTENANCE OF THE DAY 4 MARGINAL RISK OF MUCH OF NEW MEXICO INTO
EASTERN ARIZONA. FORCING BECOMES MORE WIDESPREAD AND ENCOMPASSES
MORE OF NEW MEXICO, CENTRAL ARIZONA, AND CENTRAL COLORADO FOR
MONDAY AND TUESDAY. THE LARGER DAY 5 MARGINAL RISK IS MAINTAINED.
MORE EXPANSIVE ACTIVITY IN NORTHWESTERLY FLOW IS EXPECTED SUNDAY
OVER THE UPPER OHIO VALLEY, NORTH-CENTRAL APPALACHIANS, AND MID-
ATLANTIC WITH THE 12Z CONSENSUS, SO THE DAY 4 MARGINAL RISK WAS
EXPANDED ACROSS THIS AREA.
HEAT WILL CONTINUE TO BE A MAJOR PROBLEM FOR THE MID-SOUTH THROUGH
SOUTHEAST STATES GIVEN THE SIZE OF THE UPPER RIDGE. RELIEF
PROGRESSES SOUTH, BUT IS MAINTAINED OVER THE SOUTHERN TIER THROUGH
THE MIDDLE OF NEXT WEEK. DANGEROUS HEAT INDICES ON THE ORDER OF
105 TO 115 DEGREES WILL LIKELY BE COMMON FOR THE PIEDMONT AND
COASTAL PLAIN OF THE SOUTHEAST U.S. AND INCLUDING NORTHERN FLORIDA,
WITH HEAT RISK IN THE MAJOR TO EXTREME CATEGORY FOR MUCH OF NEXT
WEEK. HOT AND HUMID OVERNIGHT LOWS WON'T PROVIDE MUCH RELIEF
EITHER.
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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