346
FXUS02 KWBC 071846
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
146 PM EST TUE FEB 07 2023
VALID 12Z FRI FEB 10 2023 - 12Z TUE FEB 14 2023
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE LATEST MODEL GUIDANCE PROVIDES A GENERAL AGREEMENT WITH THE
LARGE SCALE PATTERN THROUGH THE EXTENDED PERIOD, HOWEVER THERE
CONTINUES TO BE STRUGGLES WITH SPECIFIC DETAILS WITH THE EMBEDDED
SYSTEMS. SEVERAL RUNS OF THE GFS OF LATE HAVE BEEN TOEING THE LINE
OF BEING AN OUTLIER, ESPECIALLY WITH THE FEATURE THAT EXITS INTO
THE SOUTHERN PLAINS AND LIFTS NORTH AND EAST TOWARD THE EASTERN
SEABOARD. IT HAS BEEN CONSISTENT WITH DEVELOPING A CLOSED
LOW/TROUGH THAT SWINGS TROUGH THE SOUTH AND ON THE MORE
PROGRESSIVE SIDE OF THE CLUSTER. IT ALSO FAVORS A FURTHER
NORTHWEST PLACEMENT NEAR THE MID-ATLANTIC COAST WHILE THE REST OF
THE GUIDANCE IS CLUSTERED OFFSHORE. A SMALL AMOUNT OF THE 06Z GFS
WAS INCLUDED IN THE MULTI-MODEL INITIALIZATION BUT WAS DROPPED
AFTER DAY 3. A COMPROMISE BETWEEN THE 00Z ECWMF, CMC AND UKMET WAS
USED FOR A MAJORITY OF THE EXTENDED FORECAST. THE EC ENSEMBLE MEAN
AND THE NAEFS HAD SIMILAR SOLUTIONS TO THE PREFERRED TRIO. THE
WEIGHTING OF THE MEANS WERE STEADILY INCREASED THROUGH THE MIDDLE
AND LATTER PERIODS TO REDUCE THE AMOUNT OF SPREAD WITH THE SYSTEM
AS IT NEARS THE EAST COAST AND TRACK OFFSHORE.
..WEATHER/HAZARD HIGHLIGHTS
A COMPLEX SURFACE LOW PRESSURE SYSTEM WILL TRACK THROUGH THE
NORTHEAST AND THE CANADIAN MARITIMES FRIDAY AS AN UPPER LEVEL
TROUGH ADVANCES INTO THE SOUTHERN TIER OF THE U.S.. MEANWHILE, THE
WEST WILL CONTINUE TO HAVING AN AMPLIFYING RIDGE IN PLACE. WITH
GUIDANCE FAVORING A SLOWER PROGRESSION THERE WILL LIKELY BE A
LINGERING HEAVY RAINFALL POTENTIAL ALONG WITH SOME RISK OF RUNOFF
ISSUES WITH REPEAT/TRAINING OF CELLS ALONG A SLOW MOVING AND GULF
MOISTURE POOLING FRONT OVER THE MOIST SOILS OF THE SOUTHEAST. HIGH
RAINFALL RATES MAY LEAD TO LOCAL AREAS OF FLASH FLOODING. WPC HAS
MAINTAINED AN EXPERIMENTAL DAY 4 MARGINAL RISK FOR EXCESSIVE
RAINFALL FOR PORTIONS OF THE SOUTHEAST FRIDAY. MEANWHILE, COLD AIR
DRAPED TO THE NORTH OF THE SYSTEM AND COLD CANADIAN AIR IN THE
WAKE OF SYSTEM PASSAGE WILL ALSO OFFER A THREAT FOR SNOW/ICE ON
THE NORTHERN PERIPHERY OF THE PRECIPITATION SHIELD THROUGH
NORTHERN PORTIONS OF THE NORTHEAST AND SOUTHEAST CANADA.
LAKE-ENHANCED SNOW AND GUSTY WINDS WILL LINGER INTO THE WEEKEND.
THE DEEP UPPER TROUGH THEN SLATED TO LIFT FROM THE SOUTHEAST TO UP
THE EAST COAST FOR THE WEEKEND OFFERS MODERATE COASTAL LOW GENESIS
AND ATLANTIC INFLOW POTENTIAL TO LIFT ENHANCED LATE WEEK RAINS UP
THE EASTERN CAROLINAS/MID-ATLANTIC BEFORE RENEWING SOME MAINLY
INTERIOR NORTHEAST WEEKEND SNOWS. COLD FRONTS PASSING AHEAD OF THE
TROUGH IN THE EAST SHOULD MEANWHILE LEAD TO A TRANSITION FROM MUCH
ABOVE NORMAL TEMPERATURES THROUGH LATE WORKWEEK TO NEAR NORMAL
CONDITIONS FOR THE WEEKEND.
WHILE THERE IS A GROWING GUIDANCE SIGNAL FOR THE AMPLIFICATION OF
THE OVERALL FLOW SIGNIFICANTLY LATER WEEK ACROSS THE NATION AND
ADJOINING OCEANS, SUBSEQUENT PRECIPITATION RE-EMERGENCE MAY
OTHERWISE BE LIMITED THROUGH THE WEEKEND. NORTHERN STREAM
SHORTWAVE TROUGH PASSAGE SHOULD SUPPORT SEVERAL SHOTS FOR MODEST
PRECIPITATION, MAINLY FOR THE PACIFIC NORTHWEST AND INLAND TO THE
NORTHERN ROCKIES. MEANWHILE, UNCERTAIN EASTERN PACIFIC/WEST COAST
UPPER TROUGH/LOW AMPLIFICATION IN A DEFINING SOUTHERN STREAM COULD
LEAD TO MODEST PRECIPITATION SOUTHWARD ALONG THE CALIFORNIA COAST
AND EVENTUALLY INTO THE SOUTHWEST. BUT WITH GUIDANCE POINTING
TOWARD AN UPPER LOW IN THE SOUTHWEST BY AROUND MONDAY, GULF
MOISTURE STREAMING AHEAD OF IT COULD RENEW A RAINFALL THREAT IN
THE SOUTHERN PLAINS TO LOWER MS VALLEY BY MONDAY-TUESDAY.
CAMPBELL/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, EXPERIMENTAL EXCESSIVE RAINFALL
OUTLOOK, WINTER WEATHER OUTLOOK PROBABILITIES AND HEAT INDICES 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
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