964
FXUS02 KWBC 080625
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
225 AM EDT TUE JUL 8 2025
VALID 12Z FRI JUL 11 2025 - 12Z TUE JUL 15 2025
***HEAVY RAIN AND STORMS EXPECTED FOR THE MIDWEST AND PORTIONS OF
THE EAST COAST, AND HIGH HEAT CONTINUES FOR THE SOUTHWEST
STATES***
..PATTERN OVERVIEW
AN UPPER LEVEL LOW WILL TRACK FROM SOUTHWEST CANADA INTO THE GREAT
LAKES REGION BRINGING A SURFACE COLD FRONT FROM THE CENTRAL/NORTHERN
ROCKIES THROUGH THE NORTH-CENTRAL STATES IN THE COMING DAYS. UPPER
RIDGING WILL KEEP HOT CONDITIONS IN PLACE FOR MUCH OF THE SOUTHWEST
AND SURROUNDING LOCATIONS. DAILY SHOWERS WILL POP UP IN PROXIMITY
TO A STATIONARY BOUNDARY LINGERING NEAR THE MID- ATLANTIC REGION.
A SEPARATE COMPLEX OF ORGANIZED CONVECTION IS ALSO LIKELY FOR THE
UPPER MIDWEST THURSDAY INTO FRIDAY AHEAD OF THE FRONT.
...GUIDANCE/PREDICTABILITY ASSESSMENT
THE LARGE SCALE PATTERN BEGINS WITH HIGH PRESSURE OVER THE
SOUTHWEST AND A CLOSED LOW/TROUGH PASSING THROUGH WESTERN CANADA
AND A TROUGH PASSING THROUGH THE GREAT LAKES/HUDSON BAY/OHIO AND
TENNESSEE VALLEYS. THE FIRST DAY OR SO HAS VERY GOOD AGREEMENT
THEREFORE A MULTI-MODEL BLEND WAS USED FOR INITIALIZATION. AS BOTH
TROUGHS ADVANCE EASTWARD THROUGH THE WEEKEND AND INTO EARLY NEXT
WEEK THE SPREAD INCREASES AMONG THE SOLUTIONS RESULTING IN TIMING
AND LOCATION DIFFERENCES OF THE QPF AND AMOUNTS. THE ENSEMBLE
MEANS WERE GRADUALLY INCREASED TO ACCOUNT FOR THESE MODEL
DIFFERENCES.
..WEATHER/HAZARDS HIGHLIGHTS
SCATTERED CONVECTION ANTICIPATED TO FIRE AHEAD OF, AND ALONG PROGRESSIVE
COLD FRONTS, STALLED BOUNDARIES AND ROUND THE UPPER HIGH IN THE
SOUTHERN ROCKIES. THE EXACT LOCATION OF ANTICIPATED HIGHER QPF
AMOUNTS REMAIN A BIT UNCERTAIN GIVEN PERSISTENT MODEL DIFFERENCES,
NEVERTHELESS, THERE IS POTENTIAL FOR ISOLATED INSTANCES OF
EXCESSIVE RAINFALL AND LOCALIZED FLASH FLOODING-- INCLUDING AREAS
FROM THE CORN BELT INTO THE MIDWEST AND OHIO VALLEY, APPALACHIANS,
AND MID-ATLANTIC.
FOR DAY 4, THERE IS BROAD MARGINAL RISK AREA FOR THE UPPER
MISSISSIPPI VALLEY/MIDWEST, A BROAD MARGINAL RISK STRETCHING FROM
INTERIOR PORTIONS OF THE DEEP SOUTH TO THE MID- ATLANTIC COAST, AND
A MARGINAL RISK COVERING PORTIONS OF EASTERN COLORADO, KANSAS,
OKLAHOMA AND TEXAS PANHANDLE. FOR DAY 5, THERE IS A MARGINAL RISK
FOR EASTERN NEW MEXICO AND PARTS OF THE OKLAHOMA/TEXAS PANHANDLES
AND FROM THE CENTRAL/SOUTHERN PLAINS TO SOUTHERN PORTIONS OF THE
NORTHEAST/MARYLAND.
MANY LOCATIONS WILL HAVE DAILY MAXIMUMS CLIMBING WELL INTO THE
100S AT LOWER ELEVATIONS ACROSS THE SOUTHWEST AND MAINLY DRY
CONDITIONS, EXCEPT FOR PERHAPS FAR SOUTHEASTERN ARIZONA INTO NEW
MEXICO WHERE SOME MONSOONAL MOISTURE MAY BE PRESENT. EXPERIMENTAL
HEATRISK VALUES MAY RISE TO MAJOR OR EXTREME LEVELS (3 OUT OF 4 OR
4 OUT OF 4) FROM THE CALIFORNIA DESERTS INTO SOUTHERN NEVADA, UTAH,
AND ARIZONA. EXTREME HEAT WATCHES HAVE BEEN RAISED FOR PARTS OF
ARIZONA AND NEVADA THROUGH AT LEAST THURSDAY AND SEVERAL EXTREME
HEAT WARNINGS ARE IN EFFECT FROM SOUTHERN CALIFORNIA TO EASTERN
ARIZONA.
CAMPBELL/HAMRICK
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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