212
FXUS02 KWBC 071901
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
200 PM EST WED FEB 07 2024
VALID 12Z SAT FEB 10 2024 - 12Z WED FEB 14 2024
..GUIDANCE/PREDICTABILITY ASSESSMENT
GFS/ECMWF/CANADIAN/UKMET SOLUTIONS OFFER REASONABLY GOOD FORECAST
CLUSTERING THROUGH THE WEEKEND AND A MODEL COMPOSITE SEEMS TO
OFFER A SOLID FORECAST BASIS ALONG WITH THE NATIONAL BLEND OF
MODELS AND WPC PRODUCT CONTINUITY. FORECAST SPREAD RAPIDILY
INCREASE NEXT WEEK AS MODELS AND ENSEMBLES REMAIN HIGHLY SENSITIVE
TO EMBEDDED SYSTEM AND POTENTIAL STREAM PHASING UNCERTAINTIES IN
COMPLEX AND TRANSITIONAL FLOW. THE MAIN ISSUE IN THIS TIME FRAME
CONCERNS THE POTENTIAL DEVELOPMENT AND TRACK OF A SOUTHERN TO
EASTERN U.S. THEN WESTERN ALANTIC COASTAL STORM EARLY NEXT WEEK
AND ASSOCIATED INLAND AND MARITIME IMPACTS. NEW MACHINE LEARNING
MODELS ALSO SHOW QUITE VARIED SOLUTIONS WITH THIS MAIN SYSTEM IN
THIS PERIOD. WPC PRODUCTS HAVE TRENDED TO SHOW A LESS PROGRESSIVE
AND DEEPER LOW TRACK GIVEN POTENTIAL SUPPORT ALONG WITH A
COMPOSITE TRACK BASED ON ALL GUIDANCE.
..OVERVIEW AND WEATHER/HAZARDS HIGHLIGHTS
SPLIT FLOW ACROSS THE NATION WILL BE HIGHLIGHTED THIS WEEKEND BY
AN AMPLIFIED UPPER SHORTWAVE/POSSIBLE COMPACT CLOSED LOW IN A
SEPARATED SOUTHERN STREAM OVER THE SOUTHWEST. THIS WILL PRODUCE
LOWER ELEVATION RAINS ALONG WITH A HEAVY SNOW THREAT FOCUS FROM
THE MOGOLLON RIM TO THE SOUTH-CENTRAL ROCKIES/HIGH PLAINS AS
ENHANCED BY UPSLOPE FLOW. LEAD IMPULSES AND THE MAIN SYSTEM WILL
EJECT EASTWARD OVER THE SOUTHERN TIER OF THE LOWER 48 INTO EARLY
NEXT WEEK IN A PATTERN FAVORING INCREASING MOISTURE RETURN AND
RAINFALL POTENTIAL DOWNSTREAM ACROSS THE SOUTH WITH FRONTAL WAVE
INDUCTION. THIS MAY INCLUDE A RUNOFF/FLOODING THREAT WITH
REPEAT/TRAINING OF ACTIVITY FROM THE LOWER MISSISSIPPI VALLEY AND
CENTRAL GULF COAST STATES TO THE SOUTHEAST SATURDAY INTO MONDAY
WHERE WPC EXCESSIVE RAINFALL OUTLOOK MARGINAL RISK AREAS HAVE BEEN
POSTED. GUIDANCE CONTINUES TO OFFER LESS THAN STELLAR FORECAST
SPREAD AND RUN TO RUN CONTINUITY INTO LONGER TIME FRAMES BUT HAS
SHOWN A GROWING SIGNAL LEADING TO THE POSSIBLE LIFTING OF A
DEEPENING EAST COAST TO WESTERN ATLANTIC CYCLONE THAT COULD IMPACT
THE APPALACHIANS/MID-ATLANTIC AND NORTHEAST EARLY NEXT WEEK.
HOWEVER, DEVELOPMENT AND TRACK REMAIN CONTINGENT ON UNCERTAIN
STREAM PHASINGS AND BAROCLINIC PATTERN SET-UP. THIS TYPE OF
SCENARIO OFFERS POTENTIAL FOR LIFTING RAINS WITH FOCUS INTO THE
MID-ATLANTIC AND A WINDOW FOR WRAP-BACK PLOWABLE SNOWS FOR
MARGINALLY COOLER AREAS FROM THE APPALACHIANS THROUGH THE INTERIOR
NORTHEAST AROUND TUESDAY BEFORE EXITING OFFSHORE. MEANWHILE
OVERALL, PERIODIC ENERGY INTRUSIONS FROM THE PACIFIC WILL BRING
MODEST PRECIPITATION TO THE PACIFIC NORTHWEST WHILE NORTHERN
STREAM SYSTEM INTRUSIONS DOWN ACROSS THE U.S. NORTHERN TIER STATES
WILL OFFER PERIODIC MODEST SNOW OPPORTUNITIES.
IN TERMS OF ANOMALOUS TEMPERATURES, UPPER RIDGE PROGRESSION FROM
THE EASTERN-CENTRAL U.S. INTO THE WESTERN ATLANTIC WILL SLOWLY
SHIFT UNSEASONABLY WARM TEMPERATURES EASTWARD ACROSS THE REGION
INTO THIS WEEKEND WTH DAYTIME HIGHS UPWARDS TO 10-20+ ABOVE
NORMAL, WITH SOME POTENTIAL FOR DAILY TEMPERATURE RECORDS. IN
CONTRAST, THE SOUTHWEST U.S./CALIFORNIA SHOULD BE COOL WITH UPPER
SYSTEM PASSAGE, ESPECIALLY FOR DAYTIME HIGHS THAT MAY BE UP TO
10-15+F BELOW NORMAL THIS WEEKEND BEFORE MODERATING.
SCHICHTEL/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, EXCESSIVE RAINFALL OUTLOOK,
WINTER WEATHER OUTLOOK PROBABILITIES, HEAT INDICES AND KEY
MESSAGES ARE AT:
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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