Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 261435 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 1035 AM EDT THU MAR 26 2015 .SYNOPSIS... A WARM FRONT LIFTS THROUGH THE REGION THIS MORNING...FOLLOWED BY COLD FRONT TONIGHT. A WEAK TROUGH MOVES THROUGH FRIDAY NIGHT INTO SATURDAY...BEHIND THE DEPARTING LOW. HIGH PRESSURE BUILDS IN SUNDAY. ANOTHER FRONTAL SYSTEM MOVES THROUGH MONDAY...FOLLOWED BY HIGH PRESSURE FOR TUESDAY. A FRONTAL SYSTEM WILL APPROACH LATE WEDNESDAY INTO THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WITH LIFT SUPPLIED BY A LOW LEVEL JET AND PLENTY OF MOISTURE IN PLACE...RAIN PUSHES IN FROM THE SOUTH INTO EARLY AFTERNOON. THIS LIFT...COMBINED WITH SOME ELEVATED CAPE AND MARGINALLY UNSTABLE MID LEVEL LAPSE RATES...COULD RESULT IN AN ISOLATED RUMBLE OF THUNDER AS WELL. BETTER OVERALL CHANCES OF THUNDER WOULD BE OVER THE EASTERN HALF OF THE AREA...BUT WILL LEAVE IN MENTION OF THUNDER ACROSS THE ENTIRE AREA. EXPECTING PATCHY/AREAS OF FOG AS WELL...AND SOME OF THIS FOG COULD BE LOCALLY DENSE. NOT ENOUGH CONFIDENCE IN WIDESPREAD DENSE FOG TO GO WITH A DENSE FOG ADVISORY AT THIS POINT. BUT THIS WILL NEED TO BE WATCHED...ESPECIALLY OVER THE EASTERN HALF OF THE CWA WHERE RELATIVELY HIGHER DEWPOINTS ADVECT FROM OFF THE COLD AREA WATERS. OTHER CONCERN IS FOR LOCALIZED FLASH FLOODING...PARTICULARLY OVER EASTERN CT WHERE RAINFALL THIS AFTERNOON COULD BE BRIEFLY HEAVY DUE TO CONVECTION...AND COINCIDING WITH WHERE SNOW MELT CAN CONTRIBUTE TO RUNOFF. OVERALL THREAT IS LOW...SO NO WATCH IS PLANNED FOR THIS. USED A NAM/MAV MOS BLEND FOR HIGH TEMPERATURES...WHICH BRINGS THEM ABOVE NORMAL. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... A COLD FRONT SLOWLY PASSES THROUGH WITH MORE RAINFALL. STILL ENOUGH ELEVATED CAPE TO MENTION ISOLATED THUNDER...BUT MAINLY FOR THE EVENING. MODELS HAVE TRENDED SLOWER WITH THE END TIME OF RAINFALL...SO EVEN BY DAYBREAK FRIDAY...WILL CARRY LIKELY POPS FOR A GOOD PORTION OF THE CWA. POPS THEN GRADUALLY LOWER INTO FRIDAY AFTERNOON....WITH AT LEAST THE WESTERN HALF OF THE CWA AT A HIGH CHANCE OF REMAINING DRY DURING THE AFTERNOON. COLD ADVECTION BEHIND THE COLD FRONT WILL BE DELAYED SOMEWHAT...SO HIGHS WILL MANAGE TO AVERAGE NEAR 50. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... BROAD UPPER LEVEL TROUGH REMAINS OVER THE EAST COAST FRIDAY NIGHT INTO SATURDAY WITH THE TROUGH AXIS MOVING EAST OF THE REGION LATE SATURDAY NIGHT INTO SUNDAY. COLD AIR ADVECTION ON SATURDAY WILL MEAN LOWER THICKNESSES AND COLDER TEMPERATURES...GENERALLY 30S REGION- WIDE. SHORTWAVE ENERGY WILL ROTATE THROUGH THE UPPER TROUGH WHILE AT THE SURFACE A WEAK TROUGH REMAINS BEHIND DEPARTING LOW PRESSURE. THE COMBINATION WILL PROVIDE ENOUGH LIFT WITH LINGERING LOW LEVEL MOISTURE. WITH COLDER AIR IN PLACE...MOST OF THE AREA WILL SEE SNOW SHOWERS SATURDAY MORNING...CHANGING OVER TO RAIN SHOWERS BY LATE MORNING INTO THE AFTERNOON. PRECIPITATION LINGERS INTO SATURDAY NIGHT. SURFACE HIGH PRESSURE BUILDS IN FOR SUNDAY...THEN MOVES OFF THE COAST SUNDAY NIGHT. RIDGING ALOFT OVER THE NORTHEAST ALONG WITH DEEPENING LOW PRESSURE MOVING INTO THE GREAT LAKES WILL ALLOW FOR WARM ADVECTION AHEAD OF THE LOW. TEMPERATURES WILL WARM INTO THE 40S. LOOKS LIKE ANY PRECIPITATION FROM THIS SYSTEM WILL HOLD OFF UNTIL MONDAY MORNING. COLD FRONT MOVES THROUGH MONDAY. THERE IS LIMITED MOISTURE TO WORK WITH...SO WILL CONTINUE WITH JUST SLIGHT CHANCE POPS. WITH LOWER AMPLITUDE UPPER FLOW SYSTEMS QUICKLY MOVE EAST. AS A RESULT...HIGH PRESSURE BUILDS MONDAY NIGHT INTO TUESDAY. SOME UNCERTAINTY FOR THE AREA OF LOW PRESSURE THAT APPROACHES FOR WEDNESDAY. FOR NOW...WILL KEEP SLIGHT CHANCE POPS FOR WEDNESDAY. ANOTHER FRONTAL SYSTEM APPROACHES LATE WEDNESDAY NIGHT INTO THURSDAY...WITH A WARM FRONT MOVING THROUGH THE AREA DURING THIS TIME PERIOD. && .AVIATION /15Z THURSDAY THROUGH MONDAY/... A WARM FRONT WILL CROSS THE AREA THIS MORNING. A COLD FRONT APPROACHES FROM THE WEST ON THIS AFTERNOON...CROSSING TONIGHT. LIFR/VLIFR CONDITIONS EARLY THIS MORNING COULD BRIEFLY IMPROVE TO MVFR BETWEEN 14Z AND 18Z IN WAKE OF WARM FRONTAL PASSAGE...BEFORE COMING BACK DOWN TO IFR/LIFR THIS AFT/EVE AHEAD OF APPROACHING COLD FRONT. MODERATE POTENTIAL EXISTS FOR LIFR/VLIFR CONDS TO REMAIN OR RE-DEVELOP THIS AFTERNOON/EVENING WITH ADVECTION FOG/STRATUS ACROSS KJFK/KHPN/KBDR/KGON/KISP. LESSER THREAT OF THIS FOR KLGA/KEWR/KTEB. GRADUAL IMPROVEMENT TO MVFR IN WAKE OF COLD FRONT TONIGHT. LOW CONFIDENCE IN SPARSE THUNDER OCCURRING OVER TERMINALS THIS AFT/EVE. OTHERWISE...PERIODS OF SHRA TODAY INTO TONIGHT. HEAVIEST ACTIVITY OVER NYC METRO TERMINALS AND POINTS EAST. SOUTH WINDS DEVELOPING THIS MORNING IN WAKE OF WARM FRONT. WINDS INCREASE TO S 10-20KT MID TO LATE AFTERNOON. A FEW GUSTS TO 30 KT POSSIBLE IN AFT/EVE. WINDS SHIFT WSW AND THEN NW FROM W TO E BETWEEN 00Z AND 06Z WITH GUSTS 15 TO 20 KT. LLWS EXPECTED THIS AFT/EVE FOR COASTAL TERMINALS WITH SW WINDS AT 2 KFT OF 55-65KT AT CT/LI TERMINALS AND TO 45-55KT AT NYC TERMINALS. 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: POTENTIAL BRIEF IMPROVEMENT TO MVFR CONDS BETWEEN 14Z AND 18Z. MODERATE CONFIDENCE IN LIFR OR LOWER VSBY LATE THIS AFTERNOON INTO EVE. KLGA FCSTER COMMENTS: POTENTIAL BRIEF IMPROVEMENT TO MVFR CONDS BETWEEN 14Z AND 18Z. KEWR FCSTER COMMENTS: HIGHEST POTENTIAL FOR LIFR CONDS THROUGH 16Z. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: HIGHEST POTENTIAL FOR LIFR CONDS THROUGH 16Z. KHPN FCSTER COMMENTS: MODERATE TO HIGH CONFIDENCE IN LIFR/VLIFR CONDS PREVAILING INTO THIS EVENING. KISP FCSTER COMMENTS: MODERATE TO HIGH CONFIDENCE IN LIFR/VLIFR CONDS PREVAILING INTO THIS EVENING. .OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY... .FRIDAY...BECOMING VFR WITH TAPERING -RA. .FRIDAY NIGHT-SATURDAY...CHANCE MVFR WITH IN ANY -SHRA/-SHSN. N-NE WINDS G15-25KT POSSIBLE. .SATURDAY NIGHT-MONDAY...VFR. SW-W WINDS G15-25KT POSSIBLE. && .MARINE... WARM FRONT LIFTS THROUGH THE REGION THIS MORNING...AND THEN A COLD FRONT MOVES ACROSS THE WATERS TONIGHT BEFORE BECOMING NEARLY STATIONARY ACROSS THE OCEAN WATERS ON FRIDAY. A DENSE FOG ADVISORY HAS BEEN ISSUED FOR THIS MORNING. DENSE FOG IS LIKELY ACROSS ALL WATERS THIS MORNING AS MILD AIR MOVES IN FROM THE SOUTH OVER COLD SEA SURFACE TEMPERATURES. DID NOT HAVE THE CONFIDENCE TO GO WITH A DENSE FOG ADVISORY FOR THE ENTIRE DAY...BUT IT COULD REQUIRE AN EXTENSION IN TIME. THE PRESSURE GRADIENT WILL TIGHTEN TODAY...AND SMALL CRAFT ADVISORY CONDITIONS WILL DEVELOP ON THE OCEAN AND SOUTH SHORE BAYS THIS AFTERNOON. WINDS FALL BELOW SCA CONDITIONS ON THE SS BAYS TONIGHT...BUT SEAS WILL REMAIN ELEVATED ON THE OCEAN WATERS THROUGH AT LEAST FRIDAY. WAVES REMAIN AT OR ABOVE 5 FT FRIDAY NIGHT INTO SATURDAY WITH A STRONG NORTHWEST FLOW BETWEEN DEPARTING LOW PRESSURE TO THE EAST AND HIGH PRESSURE BUILDING TO THE WEST. ALSO...GUSTS ON THE OCEAN WATERS MAY APPROACH SMALL CRAFT FOR A WHILE SATURDAY. THE FLOW SUNDAY NIGHT INTO MONDAY BECOMES WEST THEN SOUTHWEST AS HIGH PRESSURE MOVES EAST AND ANOTHER LOW APPROACHES. WIND AND WAVES WILL BE ABOVE SCA CRITERIA FOR MONDAY THROUGH TUESDAY. GALE FORCE WINDS ARE POSSIBLE MONDAY NIGHT INTO TUESDAY. WAVES COME DOWN BELOW 5 FT ON TUESDAY. WINDS STAY ABOVE SCA THROUGH TUESDAY NIGHT. && .HYDROLOGY... AN ADDITIONAL 1/2 TO 3/4 INCH OF RAIN IS EXPECTED THROUGH FRIDAY. THEREAFTER...SIGNIFICANT PRECIPITATION IS NOT EXPECTED FRIDAY NIGHT THROUGH THE BEGINNING OF THE NEW WEEK. THE RAINFALL AND SNOW MELT WILL RESULT IN MINOR TO MODERATE RISES ON RIVERS/STREAMS ACROSS MAINLY SOUTHERN CONNECTICUT AND LOWER HUDSON RIVER VALLEY DURING THE LATE WEEK PERIOD...POSSIBLY INTO THIS WEEKEND. CURRENTLY RIVERS AND STREAMS ARE EXPECTED TO REMAIN BELOW BANKFULL...BUT THE MILD TEMPS AND INCREASED RIVER/STREAM FLOW WILL INCREASE ICE BREAKUP AND MOVEMENT DURING THE NEXT FEW DAYS. ISOLATED ICE JAMS ARE POSSIBLE...WHICH IF THEY OCCUR...COULD RESULT IN LOCALIZED FLOODING. SINCE ICE JAM FLOODING IS UNPREDICTABLE AND SUDDEN...INTERESTS ALONG ICE COVERED RIVERS SHOULD MONITOR NWS FORECASTS FOR THE LATEST INFORMATION. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEB SITE. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...DENSE FOG ADVISORY UNTIL NOON EDT TODAY FOR ANZ330-335-338-340- 345-350-353-355. SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ350-353-355. SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ345. && $$ SYNOPSIS...JC/JP NEAR TERM...JMC/JC SHORT TERM...JC LONG TERM...JP AVIATION...NV MARINE...JC/JP HYDROLOGY...JC/JP

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