821
FXUS02 KWBC 250700
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
300 AM EDT FRI OCT 25 2024
VALID 12Z MON OCT 28 2024 - 12Z FRI NOV 01 2024
...HEAVY SNOW THREATS FOR THE WEST/NORTHWEST NEXT WEEK MAY FOCUS
OVER THE CENTRAL ROCKIES TUESDAY. LEAD CENTRAL U.S. HEAT TO THEN BE
REPLACED BY A COLD/WINDY POST-FRONTAL AIRMASS AS FROST/FREEZE
ISSUES SPREAD FROM THE WEST INTO LATER NEXT WEEK...
..GENERAL OVERVIEW
AN AMPLIFIED UPPER-LEVEL TROUGH SET TO DIG INTO THE WEST THIS
WEEKEND WILL SPREAD HIGHLY UNSETTLED WEATHER ACROSS MUCH OF THE
WESTERN U.S. EARLY NEXT WEEK TO INCLUDE HIGH-ELEVATION SNOW, GUSTY
WINDS AND COLDER TEMPERATURES. THIS TROUGH WILL THEN PUSH EASTWARD
AGAINST EXPANSIVE/WARM CENTRAL TO EASTERN U.S. UPPER RIDGING;
RESULTING IN A WAVY SHARP FRONT FOR THE MID-SECTION OF THE COUNTRY
WHERE A MODERATELY HEAVY RAIN EVENT APPEARS TO EMERGE FROM THE
PLAINS THROUGH THE MISSISSIPPI VALLEY AND MIDWEST BY NEXT MIDWEEK.
..GUIDANCE/PREDICTABILITY ASSESSMENT
LATEST GFS/ECMWF/UKMET/CANADIAN MODEL GUIDANCE SEEMS WELL CLUSTERED
THROUGH EARLY TO MID NEXT WEEK AND ENJOYS GOOD ENSEMBLE AND
NATIONAL BLEND OF MODEL (NBM) SUPPORT, BOLSTERING FORECAST
CONFIDENCE. A COMPOSITE SOLUTION SEEMS TO WELL MITIGATE LINGERING
SYSTEM TIMING DIFFERENCES NEXT WEEK, ALBEIT WITH FAVORED SLOW
TRANSITION FROM THE MODELS TO A BLEND OF THE NBM AND COMPATIBLE
GEFS/ECMWF ENSEMBLE MEANS. THIS HOLDS GOOD WPC PRODUCT CONTINUITY.
..WEATHER/HAZARDS HIGHLIGHTS
A COLD FRONT ASSOCIATED WITH A DIGGING UPPER-LEVEL TROUGH FROM
THE PACIFIC WILL INCREASINGLY WORK INLAND OVER THE WEST INTO EARLY
NEXT WEEK. PERIODS OF RAIN, HIGH- ELEVATION SNOW, WINDY AND COLDER
CONDITIONS ARE EXPECTED TO OVERSPREAD MUCH OF THE REST OF THE
WESTERN U.S. THROUGH EARLY NEXT WEEK ALONG/BEHIND THE FRONT, WITH
HIGH WINDS SET TO IMPACT THE SOUTHERN ROCKIES AND SOUTHERN HIGH
PLAINS AS THE COLDER AIRMASS DIGS INTO THE REGION. THIS MAY ALSO
LEAD TO SOME FROST/FREEZE CONCERNS.
MODEST CYCLOGENESIS ACROSS THE CANADIAN PRAIRIES WILL ADVANCE A
FRONT ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST THROUGH EARLY
NEXT WEEK. THIS FRONT IS FORECAST TO SHARPEN WITH TIME AS IT
CONTINUES TO PUSH AGAINST AN EXPANSIVE HIGH PRESSURE SYSTEM
ANCHORING ACROSS THE EASTERN AND SOUTHERN U.S. SNOW WILL APPEAR TO
LINGER OVER THE NORTHERN TO CENTRAL ROCKIES AND INTO THE NORTHERN
HIGH PLAINS BEHIND A LOW PRESSURE WAVE WHERE ACCUMULATING SNOWFALL
APPEARS LIKELY. AHEAD OF THE SHARPENING FRONT, A LONG FETCH OF
RETURN FLOW FROM THE GULF OF MEXICO COULD LEAD TO A MODERATE TO
HEAVY RAIN EVENT TO EMERGE ACROSS THE MID- MISSISSIPPI VALLEY TO
THE MIDWEST WITH EMBEDDED THUNDERSTORMS BY MIDWEEK NEXT WEEK
ESPECIALLY IF A LOW PRESSURE WAVY IS ABLE TO CONSOLIDATE ALONG THE
FRONT. IN THE MEANTIME, PRECIPITATION ASSOCIATED WITH THE NEXT
PACIFIC SYSTEM IS FORECAST TO MOVE INTO THE PACIFIC NORTHWEST
DURING MIDWEEK NEXT WEEK.
THE DIGGING TROUGH IN THE WEST WILL BE MIRRORED BY A STAUNCH
DOWNSTREAM RIDGE OVER THE CENTRAL TO EASTERN U.S. NEXT WEEK. THIS
RIDGE WILL SUPPORT TEMPERATURES BETWEEN 20-30 DEGREES ABOVE AVERAGE
ACROSS THE PLAINS ON MONDAY BEFORE SPREADING INTO THE MISSISSIPPI
VALLEY AND MIDWEST/EAST INTO TUESDAY, WEDNESDAY AND THURSDAY.
THERE'S ALSO A POTENTIAL FOR WIDESPREAD TEMPERATURE RECORDS TO BE
TIED OR BROKEN ACROSS FROM ARIZONA TO TEXAS ON SUNDAY FOLLOWED BY
AN EXPANSION OF THIS INTO THE PLAINS AND UPPER MIDWEST.
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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