508
FXUS02 KWBC 021915
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
214 PM EST THU FEB 02 2023
VALID 12Z SUN FEB 05 2023 - 12Z THU FEB 09 2023
..OVERVIEW
A WAVY AND FAIRLY PROGRESSIVE UPPER-LEVEL PATTERN WILL BE PRESENT
OVER THE CONTIGUOUS STATES INITIALLY BEFORE AN UPPER TROUGH TREKS
ACROSS THE CENTRAL AND EASTERN U.S. EARLY IN THE WEEK WITH FAIRLY
DRY CONDITIONS. A TROUGH ENTERING THE WEST COAST SUNDAY WILL
SPREAD SOME PRECIPITATION TO THE WEST. AS THAT TROUGH TRACKS INTO
THE CENTRAL U.S. BY TUESDAY-WEDNESDAY, IT SHOULD TRANSITION INTO A
MUCH A WETTER PATTERN. MUCH OF THE CENTRAL AND EASTERN U.S. LOOKS
TO SEE ABOVE AVERAGE TEMPERATURES THROUGH NEXT WEEK, WITH NEAR
NORMAL CONDITIONS IN THE WEST.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE BEGINNING OF THE EXTENDED FORECAST IS WELL CLUSTERED AS A
TROUGH MOVES THROUGH THE EAST BY MONDAY AND A STRONGER TROUGH
NUDGES INTO THE WEST, WITH RIDGING IN BETWEEN. WITH OVERALL
AGREEMENT A MULTI-MODEL BLEND WAS UTILIZED FOR DAYS 3 AND 4. AS
NOTED FROM THE PREVIOUS FORECAST DISCUSSION, DIFFERENCES PERSIST
WITH THE EVOLUTION OF THE WESTERN TROUGH. GFS RUNS HAVE BEEN
SHOWING RUN TO RUN STREAM SEPARATION LEADING TO AN UPPER LOW
CLOSING OFF IN THE SOUTHWEST/NORTHERN MEXICO TUESDAY-WEDNESDAY AND
SLOWING DOWN, WITH SOME EJECTION EAST BY THURSDAY. THE ECWMF HAS
BEEN PERSISTENT IN DEPICTING A TROUGH WITH A BIT OF SEPARATION
THAT HAS A STEADY EASTWARD PROGRESSION. THE 00Z RUN OF THE ECWMF
HAS A MORE NOTABLE DEPARTURE FROM THE CLUSTERED UPPER TROUGH/LOW
OVER THE SOUTHWEST AND WANTS TO QUICKLY SHUNT THE FEATURE EASTWARD
KEEPING IT MORE PROGRESSIVE THAN THE REST OF THE GUIDANCE. THE CMC
ONCE AGAIN SEEMS TO BE THE MIDDLE GROUND SOLUTION BETWEEN THE
ECWMF AND THE GFS/UKMET AS THE CLOSED LOW/TROUGH SHIFTS EASTWARD
TOWARD THE SOUTHERN/CENTRAL PLAINS. AGAIN, THE ENSEMBLE MEMBERS BY
AND LARGE WERE SIMILAR TO THEIR PARENT MODELS. WHILE THE ECWMF WAS
NOT RULED AN OUTLIER FOR BEING MUCH FASTER THAN OTHER SOLUTIONS,
IT DID HAVE A REDUCED WEIGHTING WHEN COMPARED TO THE PREVIOUS
FORECAST. LIKEWISE, WPC DID NOT PREFER THE SLOWEST/WEST PLACEMENT
OF THE GFS BUT RATHER A CLOSER TO MIDDLE GROUND. SIMILAR WEIGHTING
WAS USED TO MAINTAIN SOME FORECAST CONTINUITY BUT TRENDED LESS OF
THE ECWMF.
..WEATHER/HAZARD HIGHLIGHTS
A COUPLE OF ROUNDS OF LIGHT PRECIPITATION ARE EXPECTED TO PASS
OVER THE MIDWEST/GREAT LAKES INTO THE NORTHEAST NEXT WEEK. AREAS
DOWNWIND OF THE LAKES MAY HAVE HIGHER AMOUNTS THAN SURROUNDING
LOCATIONS DUE TO LAKE ENHANCEMENT. SHOWERS ARE POSSIBLE ALONG THE
EASTERN SEABOARD WITH SOME MOISTURE RETURN BY SUNDAY FROM FLORIDA
INTO THE EASTERN CAROLINAS AND EASTERN PARTS OF NEW ENGLAND, BUT
ANY HEAVIER AMOUNTS LOOK TO REMAIN OFFSHORE. FOR THE WESTERN
STATES, MODERATE PRECIPITATION IS EXPECTED TO OVERSPREAD COAST TO
PORTIONS OF THE INTERMOUNTAIN WEST BY EARLY NEXT WEEK. IN GENERAL
LOWER ELEVATIONS WILL HAVE RAIN WHILE AREAS OF HIGHER ELEVATION
WILL RECEIVE SNOW; WITH TYPICAL TERRAIN ENHANCEMENT ACROSS THE
COASTAL RANGES AND THE SIERRA NEVADA. THEN PRECIPITATION COULD
OVERSPREAD THE CENTRAL U.S. BY MONDAY-TUESDAY ALONG AND AHEAD OF A
LOW PRESSURE/FRONTAL SYSTEM. THE DETAILS OF THIS PRECIPITATION
INCLUDING PLACEMENT AND PRECIPITATION TYPE REMAIN UNCERTAIN GIVEN
THE MODEL DIFFERENCES. THE CURRENT FORECAST SHOWS ENHANCED
RAINFALL AMOUNTS CENTERED ACROSS THE LOWER MISSISSIPPI VALLEY AND
SURROUNDING AREAS BY TUESDAY-WEDNESDAY, WITH SOME POTENTIAL FOR
WINTRY WEATHER ACROSS PORTIONS OF THE PLAINS TO MIDWEST, BUT THIS
IS SUBJECT TO CHANGE WITH FUTURE FORECASTS. MEANWHILE, ADDITIONAL
ROUNDS OF ENERGY COMING INTO THE WEST WILL KEEP PRECIPITATION
CHANCES LIKELY IN THE PACIFIC NORTHWEST AND THE NORTHERN ROCKIES
THROUGH MIDWEEK. THE EXACT LOCATION OF THE PRECIPITATION AND
AMOUNTS ARE OF LOWER CONFIDENCE GIVEN THE SPREAD IN MODEL
SOLUTIONS.
ANOTHER COLD MORNING IS EXPECTED SUNDAY ACROSS NORTHERN NEW
ENGLAND, BUT WITH TEMPERATURES BELOW ZERO MORE LIMITED IN SCOPE
THAN IN THE SHORT RANGE PERIOD, AND HIGHS SHOULD WARM UP CLOSE TO
NORMAL THERE DURING THE DAY. ABOVE AVERAGE TEMPERATURES OF 10 TO
20F (15-25F ABOVE AVERAGE FOR THE DAILY HIGHS) WILL CONTINUE TO
EXPAND THROUGH EARLY NEXT WEEK, WITH SOME SHIFT INTO THE EASTERN
HALF OF THE U.S. BY TUESDAY-THURSDAY. FOR THE WEST, MAXIMUM
TEMPERATURES ARE EXPECTED TO HOVER AROUND 5-10F BELOW NORMAL,
THOUGH WITH LOWS ABOUT AVERAGE.
CAMPBELL
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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