165
FXUS02 KWBC 080659
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
259 AM EDT TUE OCT 8 2024
VALID 12Z FRI OCT 11 2024 - 12Z TUE OCT 15 2024
..OVERVIEW
AN INITIAL NORTHEAST/MID-ATLANTIC UPPER TROUGH SHOULD PUSH OFF THE
COAST ON FRIDAY, WHILE A CENTRAL U.S. RIDGE WILL CONTINUE TO BRING
MUCH ABOVE NORMAL TEMPERATURES BUT WITH NORTHERN STREAM ENERGY
DAMPENING THE NORTHERN PERIPHERY. THIS ENERGY SHOULD AMPLIFY AS IT
REACHES THE EAST COAST THIS WEEKEND SETTING UP ANOTHER ROUND OF
EASTERN U.S. TROUGHING EARLY NEXT WEEK. MEANWHILE OUT WEST, ONE
SHORTWAVE INTO THE NORTHWEST THIS WEEKEND WILL BE FOLLOWED BY A
MUCH MORE AMPLIFIED TROUGH INTO THE WEST COAST NEXT WEEK WHICH WILL
ALSO ACT TO AMPLIFY UPPER RIDGING DOWNSTREAM AND ANOTHER ROUND OF
MUCH ABOVE NORMAL TEMPERATURES TO THE NORTHERN HIGH PLAINS/PLAINS.
..GUIDANCE/PREDICTABILITY ASSESSMENT
MODELS SHOW GOOD AGREEMENT ON THE OVERALL PATTERN EVOLUTION ACROSS
THE CONUS DURING THE MEDIUM RANGE PERIOD, BUT WITH SOME TYPICAL
DETAILS DIFFERENCES ESPECIALLY INTO EARLY NEXT WEEK. ONE INITIAL
AREA OF UNCERTAINTY STILL LIES WITH THE FIRST SHORTWAVE INTO THE
WEST THIS WEEKEND AND THE CMC IS STILL FASTEST WITH THIS FEATURE
AND STRONGER WITH IT AS IT MOVES INTO THE SOUTH-CENTRAL U.S. WHILE
THE REST OF THE GUIDANCE SHOWS STRONGER RIDING OVER THIS REGION.
THE CMC IS ALSO NOT AS AMPLIFIED AND MUCH FASTER WITH THE SHORTWAVE
INTO THE NORTHEAST LATE WEEKEND/EARLY NEXT WEEK, AND IS ALSO A
LITTLE MORE MUTED/FASTER WITH THE NEXT TROUGH INTO THE WEST NEXT
TUESDAY. THE WPC FORECAST FOR TONIGHT LEANED HEAVILY TOWARDS THE
ECMWF AND GFS FOR THE FIRST HALF OF THE PERIOD, INCREASING THE
ENSEMBLE MEANS LATE PERIOD, BUT STILL MAINTAINING A SLIGHTLY
MAJORITY DETERMINISTIC BLEND ON DAY 7.
..WEATHER/HAZARDS HIGHLIGHTS
A LARGE PART OF THE LOWER 48 WILL SEE FAIRLY DRY WEATHER FOR A
MAJORITY OF THE PERIOD. A COMPACT EASTERN PACIFIC UPPER TROUGH/LOW
MAY BRING A BRIEF PERIOD OF MOSTLY LIGHT RAINFALL TO THE CENTRAL
WEST COAST AROUND FRIDAY-SATURDAY, WITH A LITTLE LIGHT
PRECIPITATION POSSIBLY REACHING FARTHER EASTWARD INTO THE WEST
THEREAFTER. THEN A FRONT APPROACHING THE PACIFIC NORTHWEST MAY
BRING SOME MOISTURE INTO THE REGION BY THE START OF NEXT WEEK. THE
AMPLIFYING UPPER TROUGH AND ACCOMPANYING SURFACE EVOLUTION SHOULD
BRING SOME AREAS OF RAINFALL TO PARTS OF THE GREAT LAKES/NORTHEAST
BY LATE WEEKEND INTO THE EARLY PART OF NEXT WORK WEEK, THOUGH WITH
FAIRLY LOW CONFIDENCE IN SPECIFICS AT THIS TIME.
A CENTRAL U.S. UPPER RIDGE WILL CONTINUE TO PROMOTE AN EXTENDED
PERIOD OF WELL ABOVE NORMAL TEMPERATURES WITH NORTHERN STREAM
TROUGHING AND A COLD FRONT PUSHING THE GREATEST WARM ANOMALIES
SOUTHEAST WITH TIME FROM THE CENTRAL PLAINS AND MID/UPPER
MISSISSIPPI VALLEY TO THE SOUTHEAST FRIDAY- SATURDAY. TEMPERATURES
AROUND 10 DEGREES ABOVE NORMAL IN THE SOUTHWEST COULD SET
ADDITIONAL DAILY RECORDS THOUGH THE TEMPERATURES HAVE MODERATED
COMPARED TO RECENT DAYS AND THE SHORT RANGE. THE NORTHERN
ROCKIES/HIGH PLAINS MAY SEE TEMPERATURES REACH UP TO 10-20F ABOVE
NORMAL BY EARLY NEXT WEEK. MEANWHILE, SOME NEAR TO SLIGHTLY ABOVE
NORMAL TEMPERATURES IN THE EAST THIS WEEKEND SHOULD BE REPLACED BY
TEMPERATURES GENERALLY 5-10 DEGREES BELOW NORMAL NEXT WEEK
UNDERNEATH AMPLIFIED TROUGHING.
SANTORELLI
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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