163
FXUS02 KWBC 162017
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
417 PM EDT FRI OCT 16 2026
VALID 12Z MON OCT 19 2026 - 12Z FRI OCT 23 2026
...A NOR'EASTER COULD BRING PROLONGED IMPACTS TO COASTAL
COMMUNITIES ALONG THE EAST COAST...
..OVERVIEW
A DEVELOPING NOR'EASTER COULD BE SLOW TO EXIT THE EAST COAST,
BRINGING PROLONGED RAIN, WIND, AND WAVE HAZARDS ALONG THE MID-
ATLANTIC COAST POTENTIALLY EXTENDING INTO LATE NEXT WEEK. A DIGGING
TROUGH OFF THE WEST COAST IS FORECAST TO EVOLVE INTO A CUT-OFF
LOW, WHICH COULD TAP TROPICAL MOISTURE AND GENERATE HEAVY RAINFALL
AND MOUNTAIN SNOW OVER PORTIONS OF THE GREAT BASIN, FOUR CORNERS,
SIERRA NEVADA, AND EVENTUALLY EMERGE INTO THE HIGH PLAINS LATE NEXT
WEEK.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE AI MODELS LED THE WAY A COUPLE OF DAYS AGO IN INDICATING THE
POSSIBILITY OF A SIGNIFICANT NOR'EASTER THROUGH THE MIDDLE OF NEXT
WEEK OFF THE EAST COAST. THE DYNAMICAL ECMWF LATER INDICATED THE
POTENTIAL FOR THE NOR'EASTER TO ACQUIRE TROPICAL CHARACTERISTICS
OVER THE ABOVE NORMAL WARM WATERS NEAR THE GULF STREAM. IT TOOK A
COUPLE MORE RUNS FOR THE GFS TO SUGGEST THE POSSIBILITY OF A
NOR'EASTER. SINCE YESTERDAY, ALL DYNAMICAL MODELS HAVE FOLLOWED
SUIT TO INDICATE COASTAL CYCLOGENESIS CLOSER TOWARD THE EAST COAST
BY EARLY NEXT WEEK. WHILE THE GUIDANCE SHOWS A VARIETY OF FORWARD
MOTION OF THE NOR'EASTER THEREAFTER, RANGING AS FAR SOUTH AS
FLORIDA TO MAKING LANDFALL AT THE MID-ATLANTIC COAST, THE AVERAGE
OF ALL ENSEMBLE POSSIBILITIES SUGGEST LITTLE OVERALL MOTION
SOMEWHERE JUST OFF THE NORTH CAROLINA COAST, WITH WIND AND WAVE
IMPACTS POSSIBLY LINGERING ALONG THE MID-ATLANTIC COAST INTO LATE
NEXT WEEK.
OVER THE WESTERN U.S., MODEL CONSENSUS HAS TRENDED TOWARD A SLOWER
EASTWARD PROGRESSION FOR THE DEEP TROUGH TO DIG OFFSHORE FROM THE
WEST COAST NEXT WEEK BEFORE PUSHING INTO THE WESTERN U.S. LATER
NEXT WEEK. THE PROGRESSION HAS NOW BEEN DELAYED SO THAT RAIN IS
NOW FORECAST TO HOLD OFF ACROSS THE HIGH PLAIN UNTIL LATE NEXT
WEEK, POSSIBLY TILL FRIDAY FOR THE NORTHERN HIGH PLAINS.
..WEATHER/HAZARDS HIGHLIGHTS
A NOR'EASTER IS FORECAST TO DEVELOP OFF THE CAROLINA COAST LATER
THIS WEEKEND. RAIN ASSOCIATED WITH THE SYSTEM HAS TRENDED MORE
INLAND IN THIS LATEST CYCLE, WITH WIND POSSIBLY REACHING GALE
FORCE AS FAR WEST AS THE SOUTHERN PORTION OF THE CHESAPEAKE BAY.
HIGH WIND HAZARDS ARE CURRENTLY LIKELY FROM THE NORTH CAROLINA
COAST UP TO THE DELAWARE COAST, WHICH COULD EXTEND FURTHER UP THE
ATLANTIC COAST TOWARD LONG ISLAND AT TIMES INTO LATE NEXT WEEK.
TEMPERATURES ACROSS THE EAST COAST ARE FORECAST TO BE NORMAL TO
SLIGHTLY BELOW NORMAL, BUT COULD WIND UP BEING COLDER THAN FORECAST
IF CURRENT TRENDS CONTINUE.
AN UPPER RIDGE, AIDED BY AN AMPLIFYING UPSTREAM PATTERN AND
APPROACHING EMBEDDED SHORTWAVE ENERGY, WILL SUPPORT BROAD SOUTHERLY
FLOW AND ABOVE AVERAGE TEMPERATURES ACROSS THE CENTRAL U.S. NEXT
WEEK. THE EMBEDDED SHORTWAVE DOESN'T CARRY A THREAT OF PRODUCING
ANY PRECIPITATION.
A SHORTWAVE PASSING SOUTH OF THE GULF OF ALASKA IS FORECAST TO
DIG/AMPLIFY INTO A CUT-OFF LOW OVER THE EASTERN PACIFIC JUST OFF
THE WEST COAST MIDWEEK. THE DEPTH AND SPEED OF THIS SYSTEM WILL
DETERMINE HOW MUCH MOISTURE IT CAN PULL INTO THE REGION. THE LATEST
TRENDS SUGGEST AN INCREASING LIKELIHOOD FOR ANOMALOUS MOISTURE TO
BE PULLED INTO THE WEST. THIS MOISTURE WILL THEN INTERACT WITH A
STRONG COLD FRONT AND PRODUCE SCATTERED TO ISOLATED THUNDERSTORMS
OVER PORTIONS OF THE FOUR CORNERS. HEAVY RAINFALL MAY OCCUR AS WELL
WITH SOME EXTREME FORECAST INDEX SHIFT OF TAIL SIGNALS SHOWING UP
ACROSS THE SOUTHWEST BY NEXT TUESDAY NIGHT. SOME HIGH ELEVATION
SNOWFALL CAN'T BE RULED OUT FOR PARTS OF THE INTERMOUNTAIN WEST AND
SIERRA NEVADA BY MID-WEEK.
KONG/KEBEDE
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 FORECAST, EXCESSIVE RAINFALL OUTLOOK,
WINTER WEATHER OUTLOOK PROBABILITIES, HEAT INDICES AND KEY MESSAGES
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
HTTPS://WWW.WPC.NCEP.NOAA.GOV/#PAGE=OVW
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