002
FXUS02 KWBC 070736
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
236 AM EST TUE JAN 7 2025
VALID 12Z FRI JAN 10 2025 - 12Z TUE JAN 14 2025
...ARCTIC AIRMASS SETS STAGE FOR A LATE WEEK INTO THE WEEKEND
SNOW/ICE STORM FOCUS ACROSS PARTS OF THE SOUTH...
..GUIDANCE/PREDICTABILITY ASSESSMENT
MODEL AND ENSEMBLE FORECAST SPREAD ACROSS MUCH OF THE LOWER 48 OVER
MED-RANGE TIME SCALES HAS SEEMINGLY TURNED THE CORNER WITH LATEST
SEVERAL GUIDANCE CYCLES AND NOW SHOWS A MUCH MORE COMPATIBLE AND
CONSISTENT FORECAST, FINALLY BOLSTERING FORECAST CONFIDENCE. WHILE
SMALLER SCALE DETAILS WILL REMAIN MORE PROBLEMATIC INTO SHORT RANGE
TIME SCALES, A BROAD MODEL AND ENSEMBLE COMPOSITE ALONG SEEMS TO
MITIGATE AND OFFER A REASONABLE FORECAST AND THREAT MESSAGING
BASIS. UPCOMING RUNS OF THE NATIONAL BLEND OF MODELS WILL MOVE
EVEN MORE IN LINE AND DEFINITION TO ALLOW GOOD MAINTENANCE OF WPC
PRODUCT CONTINUITY IN LINE WITH THESE FAVORABLE TRENDS THAT INCLUDE
A STRONGER SIGNAL FOR SIGNIFICANT WINTER WEATHER OVER THE SOUTH
FRIDAY, THEN A MORE OFFSHORE SCENARIO LEANING STORM IMPACT UP/OFF
THE EAST COAST INTO THE WEEKEND, ALBEIT TO BE FURTHERED MONITORRED.
..WEATHER/HAZARDS HIGHLIGHTS
AN UNSETTLING AND COOLING EASTERN PACIFIC SYSTEM WITH WIDESPREAD
LIGHT TO MODERATE PRECIPITATION WILL WORK THROUGH AN AMBIENT AND HIGHLY
AMPLIFIED UPPER RIDGE OVER/OFF THE WEST COAST FRIDAY. A SUBSEQUENT
TRACK ACROSS THE NORTHWEST TO NORTH-CENTRAL U.S./MIDWEST THIS
WEEKEND INTO EARLY NEXT WEEK WILL FOCUS MAINLY RAINS OVER THE
PACIFIC NORTHWEST AND A THREAT OF SNOWS DOWNSTREAM AS AIDED BY
TERRAIN AND CYCLO/FRONTOGENESIS.
MEANWHILE, ANOMALOUS MOISTURE RETURN BY FRIDAY WILL FOCUS OVER THE
CENTRAL GULF COAST AS A LOW PRESSURE SYSTEM STRENGTHENS OVER THE
NORTHERN GULF OF MEXICO. A MARGINAL RISK AREAS HAS BEEN RETAINED
FOR THE DAY 4//FRIDAY WPC EXCESSIVE RAINFALL OUTLOOKS FOR
LOCALIZED FLOOD POTENTIAL. THIS THREAT DOES NOT EXTEND TO DAY 5.
WHILE THE GULF LOW STRENGTHENS AND PROGRESSES DOWNSTREAM, COLD AIR
WELL IN PLACE OVER THE SOUTH WILL SUPPORT POTENTIALLY IMPACTFUL
SNOW AND MIXED/ICY WINTRY PRECIPITATION ON THE NORTHERN PERIPHERY
OF WIDESPREAD PRECIPITATION WITH FOCUS BY FRIDAY FROM THE
TENNESSEE VALLEY TO THE CENTRAL/SOUTHERN APPALACHIANS/SOUTHEAST.
AS THE GULF SYSTEM PROGRESSES, PRECIPITATION WILL EXPAND
NORTHEASTWARD SATURDAY ACROSS AT THE SOUTHERN/EASTERN MID-
ATLANTIC.. HEAVY PRECIPITATION POTENTIAL WILL BE STRONGLY DEPENDENT
ON THE TIMING AND PLACEMENT OF THE LOW PRESSURE SYSTEM, BUT
TRENDING INCREASINGLY INTO THE WESTERN ATLANTIC AS A DEEPENING LOW
MARITIME THREAT WHILE SEEMINGLY LOWERING BUT NOT REMOVING INLAND
RISKS NORTHWARD UP THE EAST COAST.
THE WEATHER PATTERN WILL FAVOR THE CONTINUATION OF WELL BELOW
NORMAL TEMPERATURES FROM THE ROCKIES EASTWARD INTO LATE WEEK AND AT
LEAST THIS WEEKEND. EXPECT HAZARDOUS TEMPERATURE ANOMALIES TO
10-20 DEGREES BELOW NORMAL FROM THE MID-MISSISSIPPI/OHIO VALLEYS
THROUGH THE APPALACHIANS/MID-ATLANTIC AND BACK OVER THE SOUTHERN
PLAINS, ESPECIALLY FOR SNOW COVERED AREAS FROM THE JUST OCCURRING
AND UPCOMING MAJOR WINTER STORMS.
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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