999
FXUS02 KWBC 160827
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
427 AM EDT FRI OCT 16 2026
VALID 12Z MON OCT 19 2026 - 12Z FRI OCT 23 2026
...A POSSIBLE EAST COAST LOW EARLY-TO-MID NEXT WEEK COULD BRING
COASTAL IMPACTS...
..OVERVIEW
A DEVELOPING COASTAL LOW COULD PRODUCE RAIN AND WIND HAZARDS ALONG
THE MID-ATLANTIC COAST EARLY-TO-MID NEXT WEEK. A DIGGING TROUGH IN
THE WEST IS EXPECTED TO PRODUCE A CUT-OFF LOW, WHICH COULD
TAP TROPICAL MOISTURE AND GENERATE HEAVY RAINFALL AND MOUNTAIN SNOW
OVER PORTIONS OF THE FOUR CORNERS, SIERRA NEVADA, SOUTHERN PLAINS
AND GREAT BASIN NEXT WEEK.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE DETERMINISTIC GFS APPEARS TO BE COMING INTO ALIGNMENT WITH THE
EURO REGARDING A MID-LEVEL DISTURBANCE THAT LINGERS BEHIND ITS
PARENT TROUGH AND RESTRENGTHENS OVER THE CAROLINA COAST EARLY NEXT
WEEK. ALL OTHER DETERMINISTIC GUIDANCE HAVE SOME MID-LEVEL FEATURE
PRESENT, BUT THE STRENGTH OF THE LOW REMAINS THE MAIN QUESTION.
CLUSTER ANALYSIS SIGNALS THAT THE PREDOMINANT AREA OF UNCERTAINTY
IN THE 500MB PATTERN ACROSS THE CONUS DURING THE MEDIUM RANGE IS
THE TIMING/PLACEMENT OF A DIGGING EAST PACIFIC CUT-OFF LOW. THE
SPEED AT WHICH THIS SYSTEM PROPAGATES EAST WILL DETERMINE HOW MUCH
PRECIP PORTIONS OF THE SOUTHWESTERN U.S. GET BEGINNING EARLY NEXT
WEEK.
..WEATHER/HAZARDS HIGHLIGHTS
A COASTAL LOW IS EXPECTED TO DEVELOP OFF THE CAROLINA COAST LATER
THIS WEEKEND. THE CURRENT TRENDS SUGGEST MORE RAIN AND WINDS ALONG
PORTIONS OF THE MID-ATLANTIC AND NORTHEAST COASTS. HIGH WINDS
HAZARDS ARE CURRENTLY LIKELY FROM THE NORTH CAROLINA COAST UP TO
THE DELAWARE COAST. TEMPERATURES ACROSS THE EAST COAST ARE FORECAST
TO BE AVERAGE TO SLIGHTLY BELOW AVERAGE, BUT COULD WIND UP BEING
COLDER THAN FORECAST IF CURRENT TRENDS CONTINUE AND THE COASTAL LOW
STRENGTHENS AND/OR GETS CLOSER TO THE COAST.
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 MID-LEVEL DISTURBANCE WILL BREAK OFF FROM A GULF OF ALASKA LOW
AND DIG/AMPLIFY INTO A CUT-OFF LOW OVER THE EASTERN
PACIFIC/WESTERN U.S. ON TUESDAY OR WEDNESDAY. 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.
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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