084
FXUS02 KWBC 161857
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
157 PM EST WED NOV 16 2022
VALID 12Z SAT NOV 19 2022 - 12Z WED NOV 23 2022
...WINTER-LIKE TEMPERATURES ACCROSS THE U.S. ALONG WITH CONTINUED
LAKE EFFECT SNOW...
..SYNOPTIC OVERVIEW
A HIGHLY AMPLIFIED UPPER-LEVEL FLOW PATTERN CONTINUES ACROSS THE
COUNTRY TO START THE PERIOD WITH A DEEP TROUGH EXTENDING FROM
HUDSON BAY TO THE UPPER MIDWEST FORECAST TO GRADUALLY SHIFT TO THE
EAST AS ANOTHER TROUGH BEGINS TO DIG IN THE WEST LATER IN THE
PERIOD. TEMPERATURES WILL REMAIN QUITE CHILLY AND WELL BELOW
AVERAGE INITIALLY ACROSS A WIDE SWATH OF THE COUNTRY AFTER THE
PASSAGE OF AN ARCTIC FRONT AND HIGH PRESSURE REMAINS IN PLACE.
PRECIPITATION CHANCES WILL PERSIST IN FLORIDA AND BEGIN TO
INCREASE IN THE PACIFIC NORTHWEST BY THE START OF NEXT WEEK WITH
THE PASSAGE OF THE WESTERN TROUGH.
..GUIDANCE AND PREDICTABILITY ASSESSMENT
THE OVERNIGHT GUIDANCE SHOWED SLIGHTLY ABOVE AVERAGE
PREDICTABILITY PARTICULARLY THROUGH THE EARLY HALF OF THE PERIOD
WHEN MOST OF THE DETERMINISTIC GUIDANCE WAS IN GOOD AGREEMENT ON
THE OVERALL PATTERN. THE GUIDANCE DEPICTED AN AMPLIFIED TROUGH IN
THE MIDWEST/NORTHEAST AND SOUTHERN STREAM SHORTWAVE OVER THE
SOUTHERN PLAINS EARLY IN THE PERIOD FOLLOWED BY ANOTHER TROUGH
AMPLIFYING IN THE WEST WITH A RIDGE ALONG THE WEST COAST. THE 00
UTC ECMWF SHOWED GOOD CONSISTENCY WITH PAST RECENT RUNS AND BOTH
THE 00 UTC AND 06 UTC GFS BEGAN TO CONVERGE TOWARDS THIS SAME
SOLUTION, WITH THE 00 UTC UKMET ALSO IN GENERAL AGREEMENT. THE
DETERMINISTIC RUNS, SPECIFICALLY THE 00 UTC ECMWF, ALSO SHOWED
GOOD AGREEMENT WITH THE ENSEMBLE GUIDANCE LATER IN THE PERIOD WITH
RESPECT TO THE EVOLUTION OF THE WESTERN TROUGH AND POSSIBLE STREAM
SEPERATION. THE 00 UTC CMC SHOWED A MORE AMPLIFIED PATTERN OVERALL
WHICH DIVERGED MORE SIGNIFICANTLY FROM THE SOLUTIONS IN THE OTHER
GUIDANCE. THE WPC BLEND FOR THE FIRST HALF OF THE PERIOD WAS A
COMBINATION OF THE 00 UTC ECMWF AND UKMET AND 06 UTC GFS. THE 06
UTC GEFS MEAN AND 00 UTC EC MEAN WERE INCORPORATED FOR THE LATTER
HALF OF THE PERIOD WITH THE 00 UTC ECMWF INCLUDED TO PROVIDE A
MORE AMPLIFIED PATTERN. FOR THE PRECIPITATION FORECASTS, SOME OF
THE 00 UTC ECMWF WAS INCORPORATED WITH THE NBM TO INCREASE QPF IN
THE LAKE-EFFECT REGIMES OF THE LOWER GREAT LAKES AS WELL AS ALONG
THE ATLANTIC COAST OF FLORIDA EARLY IN THE PERIOD. THE QPF FROM
THE NBM WAS NOTABLY LOWER FOR THE WEST COAST FROM SOUTHERN OREGON
INTO CALIFORNIA LATER IN THE PERIOD COMPARED TO THE PRIOR WPC
FORECAST, BUT THIS WAS GENERALLY CONSISTENT WITH THE OTHER MODEL
GUIDANCE. THE 00 ECMWF WAS USED TO INCREASE AMOUNTS A BIT TO
PROVIDE MORE CONTINUITY, ALTHOUGH THE AMOUNTS STILL REMAIN LOWER
OVERALL.
..WEATHER/HAZARD HIGHLIGHTS
WIDESPREAD WELL BELOW AVERAGE TEMPERATURES ARE FORECAST TO
CONTINUE INTO THE WEEKEND ACROSS A MAJORITY OF THE COUNTRY, WITH
THE COLDEST READINGS EXPECTED ACROSS MINNESOTA, NORTH DAKOTA AND
NORTHERN WISCONSIN WHERE HIGHS WILL ONLY REACH INTO THE MIDDLE 10S
TO LOWER 20S WITH LOWS IN THE 0S OR EVEN SLIGHTLY BELOW ZERO FOR
THIS SAME GENERAL AREA. THE FRIGID TEMPERATURES WILL BEGIN TO
SHIFT INTO THE GREAT LAKES REGION AND OHIO VALLEY SUNDAY INTO
MONDAY. IT WILL ALSO BE QUITE CHILLY EXTENDING SOUTHWARD TO TEXAS
AND THE CENTRAL GULF COAST THROUGH MONDAY, WITH HIGHS GENERALLY
RUNNING 10 TO 20 DEGREES BELOW MID-LATE NOVEMBER AVERAGES.
DOWNSLOPE FLOW SHOULD HELP TO MODERATE TEMPERATURES OVER THE
CENTRAL AND SOUTHERN PLAINS BY EARLY NEXT WEEK.
IN TERMS OF PRECIPITATION, MUCH OF THE NATION SHOULD BE RELATIVELY
DRY AS THE NOTED SURFACE HIGH PRESSURE DOMINATES THE OVERALL
WEATHER PATTERN. LAKE EFFECT SNOW IS LIKELY TO BE PERSISTENT
DOWNWIND OF THE LOWER GREAT LAKES THROUGH SUNDAY OWING TO STRONG
COLD AIR ADVECTION OVER THE WARMER WATERS. SOME LIGHT SHOWERS ARE
POSSIBLE IN TEXAS SUNDAY AS THE SOUTHERN STREAM SHORTWAVE MOVES
THROUGH. DAILY CHANCES FOR HEAVIER SHOWERS AND THUNDERSTORMS WILL
PERSIST ALONG THE ATLANTIC COAST OF FLORIDA. LOWER ELEVATION
SHOWERS AND HIGHER ELEVATION SNOW WILL BEGIN IN THE PACIFIC
NORTHWEST SUNDAY AND EXPAND INTO THE NORTHERN ROCKIES BY TUESDAY
AS A TROUGH DIGS INTO THE WEST. RAIN CHANCES ALSO LOOK TO INCREASE
AHEAD OF THIS TROUGH ON WEDNESDAY ACROSS PORTIONS OF TEXAS AND THE
LOWER MISSISSIPPI VALLEY.
PUTNAM/HAMRICK
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
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page