952
FXUS02 KWBC 072127
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
426 PM EST MON NOV 07 2022
VALID 12Z THU NOV 10 2022 - 12Z MON NOV 14 2022
...POTENTIALLY SIGNIFICANT WINTER STORM LIKELY FOR THE NORTHERN
PLAINS ON THURSDAY...
...NICOLE TO IMPACT FLORIDA AND THE EAST COAST LATER THIS
WEEK/WEEKEND...
..OVERVIEW
AN AMPLIFIED UPPER TROUGH CENTERED OVER THE ROCKIES EARLY THURSDAY
SHOULD DEVELOP INTO A CLOSED LOW OVER THE UPPER MIDWEST/GREAT
LAKES BY EARLY FRIDAY. CONFIDENCE CONTINUES TO INCREASE FOR A
POTENTIALLY SIGNIFICANT WINTER STORM TO DEVELOP OVER PARTS OF THE
NORTHERN PLAINS WITH LIKELY APPRECIABLE ACCUMULATING SNOWFALL AND
STRONG WINDS THURSDAY INTO FRIDAY, THOUGH WITH CONTINUED
UNCERTAINTY FOR THE SPECIFICS. MEANWHILE, UPPER LEVEL RIDGING WILL
CONTINUE THURSDAY INTO FRIDAY ACROSS PARTS OF THE EASTERN U.S.
BEFORE WHAT IS NOW SUBTROPICAL STORM NICOLE (LIKELY TROPICAL BY
THE MEDIUM RANGE PERIOD) REACHING FLORIDA IS LIKELY TO GET PICKED
UP AHEAD OF THE APPROACHING ROCKIES/PLAINS TROUGH. NICOLE WILL
LIKELY BRING WIDESPREAD HEAVY RAINFALL AND GUSTY WINDS TO PARTS OF
FLORIDA THURSDAY AND SPREADING UP THE EASTERN SEABOARD FRIDAY AND
SATURDAY. A REBUILDING UPPER RIDGE OVER THE NORTHEAST
PACIFIC/NORTHWESTERN NORTH AMERICA WILL LIKELY YIELD MEAN
TROUGHING OVER MUCH OF CANADA INTO THE LOWER 48 BY THE WEEKEND AND
EARLY NEXT WEEK, ALONG WITH BELOW NORMAL TEMPERATURES OVER MUCH OF
THE COUNTRY.
..GUIDANCE AND PREDICTABILITY ASSESSMENT
THERE IS STILL MEANINGFUL SPREAD FOR THE DEVELOPING NORTHERN TIER
STORM DURING THE LATTER HALF OF THE WEEK, WITH LATEST GFS RUNS AND
00Z ECMWF ON THE STRONGER AND/OR SOUTHWESTERN SIDE OF THE SPREAD
AND THE 12Z UKMET FARTHEST NORTHEAST AS OF EARLY FRIDAY. THE NEW
12Z ECMWF HAS TRENDED FARTHER NORTHEAST THAN ITS PRIOR RUN,
HIGHLIGHTING THE CONTINUED UNCERTAINTY WITH IMPORTANT DETAILS.
PREFERENCE SIDED WITH AN INTERMEDIATE SOLUTION BASED ON GUIDANCE
AVAILABLE THROUGH THE 06Z CYCLE. AHEAD OF THIS SYSTEM, GUIDANCE
SHOWS SOME SHUFFLING/TRENDING FOR SUBTROPICAL STORM NICOLE WHICH
SHOULD GAIN A MORE TROPICAL CHARACTER IN COMING DAYS PER NATIONAL
HURRICANE CENTER FORECASTS. 12Z GUIDANCE TRENDS ARE GENERALLY
FASTER WITH THE NORTHWARD PROGRESSION OF NICOLE ALONG THE EAST
COAST AS THE UPPER TROUGH APPROACHES.
FARTHER WEST, MODELS AND ENSEMBLE MEMBERS ARE ALL OVER THE PLACE
FOR EXACTLY HOW INITIAL EASTERN PACIFIC SHORTWAVE ENERGY MAY SPLIT
TO PRODUCE ONE OR MORE PACIFIC UPPER LOWS/SHORTWAVES (WHICH MAY OR
MAY NOT REACH THE WEST COAST), WITH THE REST OF THE ENERGY
ROUNDING A LARGER SCALE MEAN RIDGE AND DROPPING INTO SOUTHERN
CANADA AND THE LOWER 48. THERE MAY ALSO BE A SOUTHERN STREAM THAT
CARRIES SHORTWAVE ENERGY ACROSS THE EASTERN PACIFIC AND FAR
SOUTHERN TIER U.S. THUS CONFIDENCE CONFIDENCE ULTIMATELY BECOMES
QUITE LOW FOR SHORTWAVE DETAILS ACROSS MUCH OF THE EASTERN PACIFIC
AND WITHIN THE BROAD MEAN TROUGH COVERING CANADA AND THE LOWER 48.
THE UPDATED FORECAST STARTED WITH AN OPERATIONAL COMPOSITE AND
SOME LOCALIZED MANUAL ADJUSTMENTS DURING THE FIRST PART OF THE
PERIOD TO REFLECT PREFERENCES FOR THE NORTHERN TIER STORM AND
OFFICIAL NHC TRACK FOR NICOLE. THEN THE BLEND TRANSITIONED TO
ABOUT HALF MODELS AND HALF ENSEMBLE MEANS TO BALANCE THE
INCREASING DETAIL UNCERTAINTY WHILE HOLDING ONTO SOME DEFINITION
OF FEATURES WHERE FEASIBLE. RESULTING SPECIFICS NEAR THE WEST
COAST FROM SATURDAY ONWARD DO NOT REFLECT ANY CONFIDENCE IN THAT
SPECIFIC EVOLUTION, AND INDEED THE NEW RUNS HAVE CHANGED.
..WEATHER/HAZARD HIGHLIGHTS
A WELL DEFINED SURFACE LOW LOOKS TO EMERGE OUT OF THE CENTRAL HIGH
PLAINS ON THURSDAY AND DEEPEN AS IT MOVES INTO THE UPPER
MISSISSIPPI VALLEY BY FRIDAY. WITH MODEL RUNS CONTINUING TO SHOW
THE POTENTIAL FOR ACCUMULATING AND POSSIBLY SIGNIFICANT SNOWFALL
ACROSS PARTS OF THE DAKOTAS AND FAR NORTHERN MINNESOTA THURSDAY
INTO FRIDAY, THE PROBABILITIES IN THE WINTER WEATHER OUTLOOK FOR
DAY 4 CONTINUE TO INCREASE GRADUALLY, WITH WIDESPREAD GREATER THAN
70% PROBABILITIES FROM WESTERN-CENTRAL SOUTH DAKOTA INTO FAR
NORTHERN MINNESOTA. DEPENDING ON STRENGTH OF THE LOW, GUSTY WINDS
COULD ACCOMPANY SNOWFALL AND LEAD TO POSSIBLE BLIZZARD CONDITIONS
AND DANGEROUS TRAVEL. AGAIN, WHILE A MEANINGFUL WINTER STORM OVER
PARTS OF THE NORTHERN TIER CONTINUES TO BECOME MORE LIKELY, THE
SPECIFICS IN THE PLACEMENT OF THE HEAVIEST SNOW AXIS REMAIN IN
QUESTION AND ARE DEPENDENT ON THE EXACT LOW TRACK AND STRENGTH. IN
THE WARM SECTOR OF THIS STORM, MODERATE TO HEAVY RAINFALL IS
POSSIBLE ACROSS PARTS OF THE UPPER MIDWEST AND INTO THE GREAT
LAKES, WITH A CHANCE FOR STRONG THUNDERSTORMS AS WELL. THERE COULD
BE AN AXIS OF FREEZING RAIN AND/OR SLEET BETWEEN THE SNOW AND RAIN
AREAS, BUT AGAIN DEPENDENT ON DETAILS OF THE LOW.
COASTAL AND MARITIME IMPACTS THAT INCLUDE COASTAL FLOODING,
TROPICAL STORM FORCE WINDS, HEAVY RAINFALL, ROUGH SURF, AND BEACH
EROSION ARE POSSIBLE ASSOCIATED WITH NICOLE NEAR/OVER FLORIDA AND
THE SOUTHEAST. THE DAYS 4 AND 5 EXPERIMENTAL EXCESSIVE RAINFALL
OUTLOOKS DEPICT SLIGHT RISK AREAS FROM PARTS OF FLORIDA AND THE
SOUTHEAST COAST (DAY 4) AND INTO THE EASTERN CAROLINAS/COASTAL
MID-ATLANTIC (DAY 5) TO SHOW THE POTENTIAL FOR FLASH FLOODING FROM
TROPICAL RAINS. THESE AREAS MAY HAVE TO SHIFT OR BE UPGRADED IN
FUTURE FORECASTS DEPENDING ON RAINFALL AMOUNTS AND THE TRACK OF
THE TROPICAL SYSTEM. MOISTURE FROM THIS SYSTEM SHOULD MOVE UP MUCH
OF THE EAST COAST INTO THE WEEKEND THOUGH WITH MORE UNCERTAINTY IN
THE AMOUNTS AND COVERAGE. AN APPROACHING COLD FRONT WILL LIKELY
HELP TO PROVIDE SOME FOCUSED ENHANCEMENT OF RAINFALL.
EXPECT MUCH OF THE WEST/ROCKIES INTO THE NORTHERN PLAINS TO SEE
BELOW NORMAL TEMPERATURES THROUGH THE FIRST PART OF NEXT WEEK. THE
COLDEST AIR WILL LIKELY BE ACROSS THE NORTHERN HIGH PLAINS AND
PLAINS THURSDAY-SATURDAY WITH HIGHS IN THAT AREA UP TO 20-30F
BELOW NORMAL. SOME LOCATIONS IN THE GREAT BASIN MAY SEE SIMILAR
ANOMALIES. IN CONTRAST, WELL ABOVE NORMAL TEMPERATURES WILL
PROGRESS FROM THE MIDWEST TO THE EAST COAST THURSDAY-FRIDAY WITH
WIDESPREAD DAILY RECORDS FOR WARM LOWS POSSIBLE AND A HANDFUL OF
RECORD HIGHS AS READINGS SOAR 15 TO 25 DEGREES ABOVE NORMAL. A
STRONG COLD FRONT CROSSING THROUGH THIS REGION LATE THIS WEEK WILL
USHER IN A MUCH COLDER AIRMASS, WITH HIGH TEMPERATURES BY THE
WEEKEND IN THE MIDWEST AS MUCH AS 10 TO 20 DEGREES BELOW NORMAL.
THE COOLER TEMPERATURES WILL ALSO REACH THE EAST THIS WEEKEND, AND
SUNDAY-MONDAY LOOK TO BE NEAR OR BELOW NORMAL FOR ALMOST THE
ENTIRE CONUS.
RAUSCH/SANTORELLI
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
HAZARDS:
- HEAVY PRECIPITATION ACROSS PORTIONS OF THE UPPER MISSISSIPPI
VALLEY AND THE NORTHERN PLAINS,
THU-FRI, NOV 10-NOV 11.
- HEAVY RAIN ACROSS PORTIONS OF THE NORTHERN/CENTRAL PLAINS, THE
UPPER/MIDDLE MISSISSIPPI VALLEY,
THE MID-ATLANTIC, THE SOUTHEAST, AND THE GREAT LAKES, THU-FRI, NOV
10-NOV 11.
- HEAVY RAIN ACROSS PORTIONS OF THE NORTHEAST, THE
CENTRAL/SOUTHERN APPALACHIANS, THE MID-ATLANTIC,
THE SOUTHEAST, THE GREAT LAKES, AND THE OHIO VALLEY, FRI-SAT, NOV
11-NOV 12.
- HEAVY SNOW ACROSS PORTIONS OF THE NORTHERN/CENTRAL PLAINS, AND
THE UPPER MISSISSIPPI VALLEY, THU,
NOV 10.
- SEVERE WEATHER ACROSS PORTIONS OF THE NORTHERN/CENTRAL PLAINS,
AND THE UPPER/MIDDLE MISSISSIPPI
VALLEY, THU, NOV 10.
- FLOODING POSSIBLE ACROSS PORTIONS OF FLORIDA.
- FLOODING OCCURRING OR IMMINENT ACROSS PORTIONS OF FLORIDA.
- HIGH WINDS ACROSS PORTIONS OF THE NORTHERN/CENTRAL PLAINS, AND
THE UPPER/MIDDLE MISSISSIPPI
VALLEY, THU, NOV 10.
- HIGH WINDS ACROSS PORTIONS OF THE SOUTHEAST, THU-FRI, NOV 10-NOV
11.
- MUCH BELOW NORMAL TEMPERATURES ACROSS PORTIONS OF THE
NORTHERN/CENTRAL PLAINS, FRI-SAT, NOV
11-NOV 12.
- HEAVY PRECIPITATION ACROSS PORTIONS OF MAINLAND ALASKA, SAT, NOV
12.
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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