122
FXUS02 KWBC 120658
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
157 AM EST SAT NOV 12 2022
VALID 12Z TUE NOV 15 2022 - 12Z SAT NOV 19 2022
..SYNOPTIC OVERVIEW
A RATHER COLD PATTERN IS EXPECTED TO BE IN PLACE ACROSS MUCH OF
THE NATION FOR NEXT WEEK WITH BROAD CYCLONIC FLOW ALOFT AROUND A
DEEP UPPER LEVEL TROUGH CENTERED NEAR THE NORTH-CENTRAL U.S. AND
EXTENDING INTO CENTRAL CANADA. MULTIPLE REINFORCING COLD
FRONTS/SHORTWAVES WILL HELP TO MAINTAIN THIS PATTERN, AND A STRONG
UPPER RIDGE AXIS SHOULD PREVAIL JUST OFF THE WEST COAST. THERE
WILL LIKELY BE TWO SEPARATE GULF COAST STORM SYSTEMS THAT DEVELOP
IN RESPONSE TO SHORTWAVES TRACKING AROUND THE SOUTHERN PERIPHERY
OF THE DEEP TROUGH, AND THESE ARE EXPECTED TO PRODUCE ROUNDS OF
RAIN FROM THE DEEP SOUTH TO THE EAST COAST.
..GUIDANCE AND PREDICTABILITY ASSESSMENT
THE LATEST GUIDANCE IS SHOWING AN ACTIVE PATTERN WITH MULTIPLE
SHORTWAVES INITIALLY WITHIN THE NORTHERN AND SOUTHERN STREAMS THAT
TRANSITION TO A BROAD AND PHASED TROUGH OVER MUCH OF THE NATION.
OVERALL, THERE IS GOOD SYNOPTIC SCALE AGREEMENT WITH THE BROAD
CYCLONIC FLOW EXPECTED OVER THE NORTH-CENTRAL STATES, BUT THERE IS
STILL NOTABLE SPREAD ON THE TIMING, LOCATION AND STRENGTH OF
INDIVIDUAL SHORTWAVE FEATURES THAT INCREASE BEYOND WEDNESDAY, WITH
THE 00Z GFS BECOMING STRONGER WITH THE NEXT SOUTHERN STREAM SYSTEM
CROSSING THE SOUTHERN PLAINS AND THEN THE GULF COAST REGION FOR
LATE IN THE WEEK. THE CMC HAS TRENDED CLOSER TO THE MODEL
CONSENSUS COMPARED TO ITS PREVIOUS 12Z RUN, WHICH WAS AN OUTLIER
SOLUTION ACROSS THE WESTERN U.S. WHEN COMPARED TO THE ENSEMBLE
GUIDANCE.
THE WPC FORECAST WAS PRIMARILY BASED ON A MAINLY GFS/ECMWF/UKMET
MODEL BLEND THROUGH ABOUT WEDNESDAY, 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 SATURDAY.
..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 THE
GULF COAST EARLY IN THE WEEK THAT WILL LIKELY WIDESPREAD RAIN
ACROSS MUCH OF THE DEEP SOUTH AND SOUTHEAST, AND PERHAPS THE FIRST
SNOW OF THE SEASON FROM MISSOURI TO PARTS OF THE OHIO VALLEY,
ALBEIT LIGHT AMOUNTS. IT THEN REACHES THE EAST COAST BY WEDNESDAY
AND MAY INTENSIFY FURTHER UPON REACHING THE NORTHEAST U.S. WITH
POTENTIAL SNOW FOR INTERIOR NEW ENGLAND. COLD AIR ADVECTION OVER
THE GREAT LAKES IS EXPECTED TO PRODUCE LAKE EFFECT SNOW AT TIMES,
AND SOME OF THIS SNOW COULD BE LOCALLY HEAVY.
THE OTHER NOTEWORTHY ASPECT OF THE EXTENDED FORECAST WILL BE THE
WIDESPREAD ANOMALOUS COLD WEATHER ACROSS A GREAT DEAL OF THE
NATION FOR BASICALLY ALL OF NEXT WEEK, ESPECIALLY FROM THE WESTERN
HIGH PLAINS TO THE MIDWEST WHERE BOTH HIGHS AND LOWS COULD BE
RUNNING ON THE ORDER OF 15-35 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 AND PORTIONS OF THE
WEST COAST STATES, 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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