711
FXUS02 KWBC 130807
PMDEPD
EXTENDED FORECAST DISCUSSION...AMENDED
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
305 AM EST SUN NOV 13 2022
VALID 12Z WED NOV 16 2022 - 12Z SUN NOV 20 2022
***IT WILL FEEL MORE LIKE JANUARY ACROSS MUCH OF THE U.S. WITH
WIDESPREAD SUBFREEZING HIGH TEMPERATURES EXPECTED ACROSS THE
NORTH-CENTRAL STATES ALONG WITH LAKE EFFECT SNOW***
..SYNOPTIC OVERVIEW
A RATHER COLD PATTERN IS EXPECTED TO BE IN PLACE ACROSS MUCH OF
THE NATION FOR THE MIDDLE OF THE WEEK INTO NEXT WEEKEND WITH BROAD
CYCLONIC FLOW ALOFT AROUND A DEEP UPPER LEVEL TROUGH CENTERED NEAR
THE NORTH-CENTRAL U.S. AND EXTENDING TO HUDSON BAY. MULTIPLE
REINFORCING COLD FRONTS/SHORTWAVES WILL HELP TO MAINTAIN THIS
PATTERN, AND A STRONG UPPER RIDGE AXIS SHOULD PREVAIL JUST OFF THE
WEST COAST. A WELL ORGANIZED STORM SYSTEM WILL BE EXITING THE
NORTHEAST LATE ON WEDNESDAY, WITH COASTAL RAIN AND INLAND SNOW
EXPECTED, FOLLOWED BY LAKE EFFECT SNOW DOWNWIND OF THE GREAT LAKES
..GUIDANCE AND PREDICTABILITY ASSESSMENT
THE 00Z MODEL GUIDANCE SUITE IS IN GOOD SYNOPTIC SCALE AGREEMENT
FOR THE WEDNESDAY-FRIDAY TIME PERIOD AND AGREE ON A STRONG
REINFORCEMENT OF THE COLD AIR MASS ACROSS MUCH OF THE NORTHERN
TIER STATES. HOWEVER, MORE PRONOUNCED MODEL DIFFERENCES EMERGE
GOING INTO NEXT WEEKEND WITH ARCTIC SHORTWAVE ENERGY DIVING SOUTH
ACROSS CENTRAL CANADA AND THEN THE NORTH-CENTRAL U.S. THE ECMWF
IS NOW MUCH STRONGER AND FARTHER WEST WITH A POLAR CLOSED LOW OVER
THE WESTERN GREAT LAKES, WHEREAS THE GFS HAS MORE OF AN OPEN WAVE
ALOFT AND NOT AS ANOMALOUS. THE CMC ALSO HAS A CLOSED POLAR LOW,
BUT IT IS FARTHER EAST AND CLOSER TO THE GFS IN TERMS OF
PLACEMENT. THIS LEADS TO LOWER THAN NORMAL FORECAST
PREDICTABILITY FOR THE END OF THE FORECAST PERIOD.
THE WPC FORECAST WAS PRIMARILY BASED ON A MULTI-DETERMINISTIC
MODEL BLEND THROUGH ABOUT THURSDAY, FOLLOWED BY INCREASING THE
INCLUSION OF THE GEFS AND EC ENSEMBLE MEANS TO ACCOUNT FOR THE
GREATER MODEL DIFFERENCES GOING INTO THE END OF THE WEEK AND INTO
NEXT WEEKEND. IN TERMS OF QPF, A BLEND OF ABOUT 25% GFS/25%
CMC/50% NBM WAS USED AS A BASELINE FOR THE GREAT LAKES REGION TO
ADD MORE DETAIL TO THE EXPECTED LAKE EFFECT SNOWFALL.
..WEATHER/HAZARD HIGHLIGHTS
THERE WILL BE TWO MAIN THINGS MAKING WEATHER HEADLINES GOING INTO
NEXT WEEK. THE FIRST WILL BE AN ORGANIZING STORM SYSTEM NEAR NEW
ENGLAND BY MIDWEEK THAT IS FORECAST TO PRODUCE WIDESPREAD RAIN
ACROSS MUCH OF THE MID-ATLANTIC AND INTO COASTAL PORTIONS OF THE
NORTHEAST, AND ACCUMULATING SNOW FOR INTERIOR PORTIONS OF NEW
ENGLAND. STRONG COLD AIR ADVECTION OVER THE GREAT LAKES IS
EXPECTED TO PRODUCE LAKE EFFECT SNOW FOR SEVERAL DAYS, AND SOME OF
THIS SNOW COULD BE LOCALLY HEAVY AT TIMES.
THE OTHER NOTEWORTHY ASPECT OF THE EXTENDED FORECAST WILL BE THE
WIDESPREAD ANOMALOUS COLD WEATHER ACROSS A GREAT DEAL OF THE
NATION FOR THE ENTIRE FORECAST PERIOD, ESPECIALLY FROM MONTANA AND
WYOMING EASTWARD TO THE MIDWEST WHERE AFTERNOON HIGHS COULD BE
RUNNING ON THE ORDER OF 15-30 DEGREES BELOW TYPICAL MID-NOVEMBER
AVERAGES. SOME DAILY RECORD LOWS ARE ALSO WITHIN THE REALM OF
POSSIBILITY FOR THESE AREAS. THE EXCEPTIONS TO THE COLD WEATHER
WILL LIKELY BE ACROSS THE FLORIDA PENINSULA WITH READINGS NEAR OR
SLIGHTLY ABOVE AVERAGE.
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
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