Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 291810 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 110 PM EST THU JAN 29 2015 .SYNOPSIS... HIGH PRESSURE OVER THE AREA THIS MORNING WILL SLIDE OFFSHORE TODAY. AN AREA OF LOW PRESSURE WILL APPROACHES FROM THE WEST THURSDAY EVENING...THEN CROSSES THE AREA LATE THURSDAY NIGHT AND FRIDAY...IMMEDIATELY FOLLOWED BY AN ARCTIC COLD FRONT. LOW PRESSURE DEEPENS AS IT DEPARTS TO THE EAST FRIDAY NIGHT. HIGH PRESSURE BUILDS SATURDAY. A WEAK COLD FRONT MOVES THROUGH ON SUNDAY. LOW PRESSURE MOVES OUT OF THE MISSISSIPPI VALLEY AND TRACKS TO THE SOUTH MONDAY. HIGH PRESSURE FOLLOWS INTO MID WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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THE RIDGE WAS MOVING OFFSHORE AS MID AND HIGH CLOUDS CONTINUE TO PUSH EAST WITH THE ADVANCE OF LOW PRESSURE TO THE WEST. THE WIND WAS GENERALLY LIGHT AND SLOWLY SHIFTING TO THE SOUTH. THE COMBINATION OF VERY WEAK WARM ADVECTION AND SUNSHINE WAS ALLOWING FOR TEMPERATURES TO RISE A LITTLE MORE QUICKLY...ESPECIALLY ALONG THE COAST. DEW POINTS WERE SLOWER TO RISE...HOWEVER...A SLOW UPWARD TREND WILL CONTINUE THIS AFTERNOON.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... FAIRLY HIGH CONFIDENCE IN THE SHORT TERM AS A CLIPPER SYSTEM MOVES ACROSS THE REGION TONIGHT AND FRIDAY. THERE IS SOME UNCERTAINTY WITH TEMPERATURES. THINKING THAT LATEST MAV/MET GUIDANCE IS A BIT TOO WARM...SO CUT TEMPERATURES A DEGREE OR TWO...ESPECIALLY WITH A SNOWPACK ACROSS THE MUCH OF THE AREA. WILL CONTINUE TO GO WITH SNOW JUST ABOUT EVERYWHERE - THOUGH EXPECT A WET SNOW FOR THE COAST. SNOWFALL TOTALS WILL RANGE FROM 1 TO 2 INCHES ACROSS THE ENTIRE CWA. 1 INCH CLOSER TO THE COAST AND 2 FURTHER NORTH AND WEST OF NYC. THE CLIPPER PULLS AN ARCTIC FRONT ACROSS THE REGION WITH A MASSIVE DROP IN TEMPERATURES DURING THE LATE AFTERNOON. IT WILL BECOME WINDY BY LATE AFTERNOON...DROPPING WIND CHILLS INTO THE SINGLE DIGITS OVER WESTERN ZONES AND TEENS AND LOWER 20S OVER EASTERN ZONES. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... GLOBAL MODELS ARE IN GENERAL AGREEMENT ON TROUGH CLOSING OFF AS IT TRAVERSES JUST TO THE EAST FRIDAY NIGHT. NOT A LOT OF CHANGE IN THE UPPER FLOW AS CLOSED LOW REMAINS OVER HUDSON BAY...WITH DEEP TROUGH OVER THE ATLANTIC. MEAN TROUGH REMAINS FROM THE CENTRAL STATES EASTWARD. RIDGE OUT WEST FLATTENS SOMEWHAT IN TIME. AT THE SURFACE...LOW PRESSURE DEEPENS OVER THE GULF OF MAINE AS IT MOVES SLOWLY EAST. HIGH PRESSURE MOVES OUT OF THE UPPER MID WEST TOWARD THE OHIO VALLEY FRIDAY NIGHT. IN BETWEEN...VERY TIGHT PRESSURE GRADIENT IS IN PLACE ACROSS THE NORTHEAST. THE HIGH MOVES WELL TO THE SOUTH...WITH A WEAK FRONT BETWEEN ANOTHER HIGH TO THE NORTH. THIS FRONT MOVES THROUGH SOMETIME SUNDAY...WITH LITTLE FANFARE. THEN ATTENTION TURNS TO LOW PRESSURE THAT TRACKS ACROSS THE LOWER MISS VALLEY SUNDAY. ANALYSIS OF VARIOUS MODEL TRACKS WOULD PUT THE LOW OFF THE MID ATLANTIC STATES SOMETIME MONDAY...WITH GGEM MUCH SLOWER. SOLUTIONS FROM RUN TO RUN CONTINUE TO WAFFLE AND UNCERTAINTY EXISTS. VARIOUS SOURCES OF ENERGY IN THE SHORT TERM DO NOT REACH WESTERN CANADA UNTIL FRIDAY...SO IT MAY TAKE UNTIL AT LEAST LATE FRIDAY FOR POSSIBLE SOLUTIONS TO CONVERGE HOPEFULLY. WILL THUS NOT STRAY FAR FROM PREVIOUS FORECAST...BUT WILL INTRODUCE POPS SUNDAY NIGHT AND CONTINUE INTO MONDAY. COLD AIR WILL PREVAIL. DANGEROUSLY COLD FRIDAY NIGHT COURTESY OF STRONG COLD AIR ADVECTION AND STRONG NW WINDS. IN FACT...WINDS MAY REACH ADVISORY CRITERIA FOR PORTIONS OF THE AREA...AND THESE WINDS ALONG WITH PLUMMETING TEMPS WILL YIELD BELOW ZERO WIND CHILL READINGS. NW ZONES LIKELY APPROACH WIND CHILL ADVISORY CRITERIA OF -15. ANOTHER ROUND OF DANGEROUSLY COLD TEMPS ARRIVES BEHIND THE MONDAY NIGHT SYSTEM. LEANED TOWARD WPC NUMBERS...WITH SOME WEIGHT TO PREVIOUS FORECAST. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/...
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HIGH PRESSURE SLIDES OFFSHORE THIS AFTERNOON. LOW PRESSURE APPROACHES FROM THE WEST THIS EVENING...CROSSES THE AREA OVERNIGHT AND FRIDAY MORNING...THEN EXITS TO THE EAST AS IT DEEPENS FRIDAY AFTERNOON. VFR THIS AFTERNOON. MVFR LIKELY DEVELOPS AROUND/JUST AFTER MIDNIGHT WITH THE ONSET OF LIGHT SNOW...THEN IFR IN LIGHT SNOW FROM 5-8Z FROM NW TO SE THROUGH 11-15Z FROM NW TO SE...WHEN SHOULD RETURN TO MVFR WITH SCATTERED SNOW SHOWERS FOR REMAINDER OF TAF PERIOD. GENERALLY EXPECTING 1-2 INCH SNOWFALL WITH HIGHEST AMOUNTS AT NORTHERN TERMINALS. NOTE THERE IS A LOW CHANCE OF FZRA/RAIN AT FAR EASTERN TERMINALS LATE TONIGHT BEFORE THE ONSET OF STEADY SNOW. LIGHT AND VARIABLE WINDS BECOME SE AT LESS THAN 10 KT AT CITY TERMINALS THIS AFTERNOON. WINDS THEN VEER TO THE S THIS EVENING...REMAINING LIGHT AND VARIABLE INLAND. WINDS SHIFT SW-W-NW FRIDAY MORNING (11-15Z CITY TERMINALS)...WITH GUSTS TO AROUND 20-25 KT BY EARLY AFTERNOON. HIGH CONFIDENCE IN OCCURRENCE OF WINDS. MODERATE TO HIGH CONFIDENCE IN SNOW AND ASSOCIATED MVFR/IFR CONDITIONS. CONFIDENCE IN EXACT TIMING IS LOWER. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: TIMING OF CHANGES IN WIND SPEED AND DIRECTION AND CHANGES IN FLIGHT CATEGORIES COULD BE OFF +/- 2-3 HOURS. MOST LIKELY SNOW ACCUMULATION IS AROUND 1". KLGA FCSTER COMMENTS: TIMING OF CHANGES IN WIND SPEED AND DIRECTION AND CHANGES IN FLIGHT CATEGORIES COULD BE OFF +/- 2-3 HOURS. MOST LIKELY SNOW ACCUMULATION IS AROUND 1". KEWR FCSTER COMMENTS: TIMING OF CHANGES IN WIND SPEED AND DIRECTION AND CHANGES IN FLIGHT CATEGORIES COULD BE OFF +/- 2-3 HOURS. MOST LIKELY SNOW ACCUMULATION IS AROUND 1". THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: TIMING OF CHANGES IN WIND SPEED AND DIRECTION AND CHANGES IN FLIGHT CATEGORIES COULD BE OFF +/- 2-3 HOURS. MOST LIKELY SNOW ACCUMULATION IS AROUND 1". KHPN FCSTER COMMENTS: TIMING OF CHANGES IN WIND SPEED AND DIRECTION AND CHANGES IN FLIGHT CATEGORIES COULD BE OFF +/- 2-3 HOURS. MOST LIKELY SNOW ACCUMULATION IS 1-2". KISP FCSTER COMMENTS: TIMING OF CHANGES IN WIND SPEED AND DIRECTION AND CHANGES IN FLIGHT CATEGORIES COULD BE OFF +/- 2-3 HOURS. MOST LIKELY SNOW ACCUMULATION IS JUST UNDER 1". .OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY... .FRIDAY AFTERNOON...MOST LIKELY VFR...MVFR IN ISOLD -SHSN A LOW POSSIBILITY. NW WIND G20-30 KT LIKELY. .FRIDAY NIGHT-SATURDAY...VFR. NW WINDS G30-40KT LIKELY. .SATURDAY NIGHT...VFR. NW WIND G 20-30KT POSSIBLE EARLY. .SUNDAY...VFR. NW WIND G15-20KT POSSIBLE. .SUNDAY NIGHT- MONDAY..CHANCE OF SNOW WITH IFR CONDITIONS. NE-N WIND G25-35KT POSSIBLE. .MONDAY NIGHT...BECOMING VFR FROM W TO E AS ANY SNOW COMES TO AN END. N-NW WIND G20-25KT POSSIBLE. .TUESDAY...VFR.
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&& .MARINE...
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SUB-SCA CONDITIONS CONTINUE THIS AFTERNOON AS THE HIGH WAS MOVING OFF THE NORTHEAST TO MID ATLANTIC COAST. WINDS SHIFT AROUND TO THE SOUTH AS THE HIGH MOVES EAST. WINDS AND SEAS START TO INCREASE LATE TONIGHT IN RESPONSE TO A TIGHTENING PRESSURE GRADIENT. EXPECT SMALL CRAFT ADVISORIES ON THE OCEAN WATER TONIGHT STARTING AT 6Z. A CLIPPER SYSTEM MOVING NORTH OF THE WATERS WILL DRAG AN ARCTIC FRONT ACROSS THE WATERS ON FRIDAY. WINDS RAPIDLY INCREASE LATE FRIDAY. EXPECT GALE FORCE GUSTS TO START TO DEVELOP AFTER 18Z FRIDAY. AS LOW PRESSURE DEEPENS TO THE EAST AND HIGH PRESSURE BUILDS TO THE WEST...STRONG GALES ARE EXPECTED FRIDAY NIGHT INTO SATURDAY MORNING. IN FACT...SOME GUSTS COULD APPROACH STORM FORCE. OVERALL THOUGH GUSTS OF 35 TO 45 KT ARE EXPECTED. VERY COLD TEMPS WILL RESULT IN FREEZING SPRAY FRIDAY NIGHT INTO SATURDAY. WINDS DIMINISH SLOWLY LATER SATURDAY AND SATURDAY NIGHT AS HIGH PRESSURE PASSES WELL SOUTH AND A WEAK FRONT APPROACHES FROM THE NORTH. ANOTHER AREA OF LOW PRESSURE IS EXPECTED TO APPROACH LATE SUNDAY AND MOVE JUST SOUTH OF THE WATERS MONDAY. WINDS INCREASE BEHIND THIS LOW. ROUGH SEAS FRIDAY NIGHT AND SATURDAY WILL GRADUALLY SUBSIDE WITH THE DIMINISHING WINDS. SEAS BUILD AGAIN MONDAY.
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&& .HYDROLOGY... NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH FRIDAY...THOUGH SOME LIGHT SNOW IS EXPECTED TONIGHT INTO FRIDAY...WITH NO HYDROLOGIC IMPACT EXPECTED. THERE IS THE POTENTIAL FOR SIGNIFICANT PRECIPITATION IN THE FORM OF SNOW...OF AT LEAST 1/2 INCH LIQUID EQUIVALENT SUNDAY NIGHT AND MONDAY. HOWEVER...MUCH UNCERTAINTY EXISTS AS THE STORM MAY PASS FAR ENOUGH TO THE SOUTH FOR LITTLE OR NO PRECIPITATION. STAY TUNED. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...GALE WARNING FROM 1 PM FRIDAY TO 6 AM EST SATURDAY FOR ANZ330- 335-338-340-345-350-353-355. SMALL CRAFT ADVISORY FROM 1 AM TO 1 PM EST FRIDAY FOR ANZ350- 353-355. && $$ SYNOPSIS...BC/PW NEAR TERM...BC/MET/PW SHORT TERM...BC LONG TERM...PW AVIATION...GOODMAN/MALOIT MARINE...BC/PW HYDROLOGY...BC/PW

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