Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 251452 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 952 AM EST WED FEB 25 2015 .SYNOPSIS... A COLD FRONT MOVES ACROSS THE REGION TODAY. LOW PRESSURE PASSES WELL OFFSHORE ON THURSDAY FOLLOWED BY ARCTIC HIGH PRESSURE SLOWLY BUILDING TOWARD THE AREA LATE THIS WEEK AND INTO THE WEEKEND. A COLD FRONT APPROACHES LATE SUNDAY...AND MOVES ACROSS THE AREA EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATED SKIES TO INDICATE CLR FOR THIS MRNG. OTHERWISE NO MAJOR CHANGES MADE. DEEPENING LOW PRESSURE WELL EAST OF LONG ISLAND WILL PASS WELL TO THE NORTH AND EAST OF THE REGION TODAY AS A COLD FRONT MOVES THROUGH THIS AFTERNOON. EXPECTING A GOOD DEAL OF SUNSHINE WITH ONLY A FEW STRATOCUMULUS AND HIGH CIRRUS CLOUDS. WITH A WESTERLY FLOW AHEAD OF THE FRONTAL PASSAGE...EXPECTING TEMPERATURES TO RISE INTO THE LOWER 30S INLAND TO THE MIDDLE AND POSSIBLY UPPER 30S ACROSS COASTAL CONNECTICUT...METRO NE NEW JERSEY...NEW YORK CITY...AND LONG ISLAND. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... HEIGHTS WILL BE RISING ALOFT TONIGHT AS A FAIRLY ROBUST SHORTWAVE IN THE SOUTHERN BRANCH OF THE UPPER LEVEL JET DEVELOPS A SURFACE LOW ALONG THE SOUTHEAST COAST. AHEAD OF THIS DEVELOPING LOW...CLOUDS WILL INCREASE ACROSS OUR CWA OVERNIGHT. TEMPERATURES WILL FALL INTO THE THE SINGLE DIGITS INLAND TO THE LOWER AND MIDDLE TEENS ELSEWHERE. THE CONSENSUS OF THE LATEST MODEL GUIDANCE CONTINUES TO DEPICT THE LOW PASSING WELL TO THE SOUTH AND EAST OF THE AREA THURSDAY. THE BEST LIFT AND MID-LEVEL FORCING STAY WELL TO THE SOUTH AND THE UPPER LEVEL SHORTWAVE RESPONSIBLE FOR THE LOW PRESSURE WILL ALSO BE WEAKENING AS IT APPROACHES. THE LOW LEVEL AIR WILL BE QUITE DRY AS WELL...MAKING IT DIFFICULT FOR ANY SUBSTANTIAL SNOWFALL TO MAKE IT TO THE SURFACE. FORECASTING SLIGHT CHANCE POPS FOR LIGHT SNOW DURING THE DAY WITH THE SMALL POSSIBILITY THE NORTHERN FRINGE OF THE PRECIPITATION SHIELD IS ABLE TO ADVANCE SLIGHTLY FURTHER NORTH. TEMPERATURES ON THURSDAY WILL BE IN THE LOWER TO MIDDLE 20S. WIND CHILLS WILL BE IN THE SINGLE DIGITS IN THE MORNING AND RISE INTO THE TEENS DURING THE AFTERNOON. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... ELONGATED TROUGH EXTENDING FROM NORTHEAST TO SOUTHWEST ACROSS THE GREAT LAKES REGION WEAKENS AS IT APPROACHES THE NORTHEASTERN STATES FRIDAY. GLOBAL MODELS AGREE ON GENERAL ZONAL FLOW ALOFT SATURDAY...WITH DIFFERENCES ARISING ON UPSTREAM TROUGH AND SHORTWAVE ENERGY. ANALYSIS OF GLOBAL MODELS INCLUDING GFS AND ECMWF SHOWS NORTHERN STREAM SHORTWAVE QUICKLY MOVING ACROSS THE AREA LATE THIS WEEKEND AND INTO MONDAY. STRENGTH OF THIS TROUGH DIFFERS...AS DOES TIMING. TROUGH AXIS PIVOTS EAST...WITH EITHER FLAT FLOW OR WEAK RIDGE BUILDING BEHIND. THEN WESTERN TROUGH AND ASSOCIATED ENERGY EJECTS AND TRACKS ACROSS THE MID PORTION OF THE COUNTRY TUESDAY...WITH LARGER DIFFERENCES NOTED. THUS LOWER CONFIDENCE IN FORECAST DETAILS. AT THE SURFACE...ARCTIC HIGH PRESSURE DIVES OUT OF CENTRAL CANADA AND MOVES ACROSS THE UPPER MID WEST THURSDAY NIGHT AND FRIDAY. RIDGING EXTENDS ACROSS THE GREAT LAKES REGION...WITH PREVAILING NORTHERLY FLOW FOR OUR AREA THROUGH FRIDAY. GLOBAL MODELS ALL FORECAST A SLOW PROGRESSION EAST ACROSS THE OHIO VALLEY FRIDAY NIGHT...WITH THE CENTER OF THE HIGH MOVING OVERHEAD LATE SATURDAY/SATURDAY NIGHT. COLD FRONT APPROACHES SUNDAY...MOVING ACROSS THE AREA SOMETIME SUNDAY NIGHT OR EARLY MONDAY. HIGH PRESSURE THEN BUILDS TOWARD THE AREA MONDAY...WITH ECMWF SLOWER THAN GFS AND GFS ENSEMBLE MEAN. BY TUESDAY...LOW PRESSURE TRACKS ACROSS THE MID WEST TOWARD GREAT LAKES REGION...WITH ECMWF SLOWER THAN GFS/GFS ENSEMBLE MEAN. WHAT THIS MEANS IS MAINLY A DRY FORECAST THROUGH SATURDAY NIGHT. BY SUNDAY...PRECIP CHANCES INCREASE FROM THE WEST...WITH PERHAPS THE GREATEST CHANCE FOR PRECIP SUNDAY NIGHT AHEAD OF THE COLD FRONT. HOWEVER...QPF SHOULD BE MINIMAL AS NOT A LOT OF MOISTURE PRESENT AHEAD OF THE FRONT. PTYPE WILL BE PROBLEMATIC...AND SNOW COULD BECOME A WINTRY MIX...WITH DIFFERENCES NOTED ALOFT WITH REGARD TO WAA. WINTRY PRECIP LIKELY ENDS MONDAY...WITH ADDITIONAL WINTRY PRECIP POSSIBLE SOMETIME TUESDAY. AGAIN...DETAILS REMAIN UNCLEAR DUE TO MODEL DIFFERENCES NOTED. TEMPS REMAIN DOWNRIGHT COLD COURTESY OF ARCTIC HIGH AND NORTHERLY FLOW THROUGH SATURDAY. LOWS THURSDAY NIGHT IN THE SINGLE DIGITS AND TEENS...WITH A COLDER NIGHT LIKELY FRIDAY NIGHT. EXPECTED LOWS FROM AROUND ZERO TO THE SINGLE DIGITS. QUITE COLD FOR LATE FEBRUARY. EXPECTED HIGHS FRIDAY AND SATURDAY WILL AVERAGE AROUND 20 TO 25 DEGREES BELOW SEASONAL NORMS. 20S EXPECTED FOR DAYTIME HIGHS. ANOTHER CHILLY NIGHT IS EXPECTED SATURDAY NIGHT DUE TO CLEAR SKIES AND LIGHT WINDS AS THE CENTER OF THE HIGH BUILDS OVERHEAD. ON SUNDAY...SOUTHERLY FLOW AHEAD OF THE COLD FRONT WILL ALLOW TEMPS TO RISE CLOSE TO THE FREEZING MARK. WHILE THIS IS WARMER...IT IS STILL 10 TO 15 DEGREES BELOW NORMAL. TEMPS WILL BE CLOSER TO NORMAL LEVELS SUNDAY NIGHT THROUGH TUESDAY...ALTHOUGH THEY LIKELY REMAIN SLIGHTLY BELOW ON AVERAGE. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... A COLD FRONT WILL MOVE ACROSS THE REGION THIS AFTERNOON...FOLLOWED BY HIGH PRESSURE TONIGHT. HIGH CONFIDENCE IN VFR CONDITIONS TODAY. W WINDS 10-15 KT WITH GUSTS AROUND 20 KT TODAY. WINDS THEN VEER NW-N DIMINISH TO UNDER 10 KT THIS EVENING. 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 WIND GUSTS MAY BE OFF BY +/- 1 HOUR. KLGA FCSTER COMMENTS: TIMING OF WIND GUSTS MAY BE OFF BY +/- 1 HOUR. KEWR FCSTER COMMENTS: TIMING OF WIND GUSTS MAY BE OFF BY +/- 1 HOUR. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: TIMING OF WIND GUSTS MAY BE OFF BY +/- 1 HOUR. KHPN FCSTER COMMENTS: TIMING OF WIND GUSTS MAY BE OFF BY +/- 1 HOUR. KISP FCSTER COMMENTS: TIMING OF WIND GUSTS MAY BE OFF BY +/- 1 HOUR. .OUTLOOK FOR 12Z THU THROUGH SUNDAY... .THU...LOW CHANCE OF LIGHT SNOW WITH MVFR CONDITIONS. .FRI-SAT...VFR. .SUNDAY...VFR DAYTIME. THEN CHANCE OF MIXED PCPN WITH MVFR CONDITIONS AT NIGHT. && .MARINE... LOW PRES PASSES TO THE EAST OF THE WATERS THIS MORNING. BEHIND THE LOW...THE PRESSURE GRADIENT TIGHTENS. WILL CONTINUE THE SCA UNTIL 23Z ON THE OCEAN WATERS FOR GUSTS TO 25 KT AND SEAS BUILDING TO AROUND 5 FT. THERE ALSO REMAINS THE POSSIBILITY OF SOME LIGHT FREEZING SPRAY ON THE OCEAN WATERS DURING THE DAY. THE PRESSURE GRADIENT RELAXES TONIGHT INTO THURSDAY...ALLOWING CONDITIONS TO FALL BELOW SCA LEVELS ON ALL WATERS. AS ARCTIC HIGH PRESSURE SLOWLY APPROACHES THE WATERS THURSDAY NIGHT THROUGH SATURDAY...EXPECT A PREVAILING NORTHERLY FLOW ACROSS THE WATERS. IN GENERAL...SUB SCA CONDITIONS ARE EXPECTED THROUGH THIS TIME FRAME. WINDS LIGHTEN SATURDAY NIGHT AS THE HIGH MOVES OVERHEAD. THEN SOUTHERLY WINDS PREVAIL AS THE HIGH MOVES EAST AND A COLD FRONT APPROACHES FROM THE WEST. SEAS REMAIN 5 FEET OR LESS OVER THE OCEAN WATERS LATE THIS WEEK. SEAS SUBSIDE THIS WEEKEND AS WINDS LIGHTEN. FOR THE HARBORS/BAYS AND SOUND...SEAS/WAVES REMAIN RATHER TRANQUIL THROUGH THE LATE WEEK AND WEEKEND PERIOD. MANY AREAS ARE AFFECTED BY ICE AS WELL...AND THIS CONTINUES AS COLD AIR REMAINS ENTRENCHED ACROSS THE NORTHEAST. && .HYDROLOGY... MAINLY DRY WEATHER CAN BE EXPECTED THROUGH SUNDAY. THERE IS A CHANCE FOR MEASURABLE PRECIPITATION SUNDAY NIGHT INTO MONDAY...AND AGAIN NEXT TUESDAY. HOWEVER...SIGNIFICANT LIQUID EQUIVALENT IS NOT EXPECTED AT THIS TIME THROUGH MONDAY. ICE WILL CONTINUE TO DEVELOP ON LOCAL AREA RIVERS AND STREAMS AS TEMPS REMAIN WELL BELOW AVERAGE. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ350- 353-355. && $$ SYNOPSIS...DS/PW NEAR TERM...JMC/DS/PW SHORT TERM...DS LONG TERM...PW AVIATION...DW MARINE...DS/PW HYDROLOGY...DS/PW

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