Area Forecast Discussion
Issued by NWS Upton, NY

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KOKX 092331 AFDOKX Area Forecast Discussion National Weather Service New York NY 731 PM EDT Thu Apr 9 2020 .SYNOPSIS... High pressure will build from the west Friday through Saturday night, then move offshore on Sunday. A complex low pressure system will approach Sunday night and move across on Monday. A cold front will move across on Tuesday. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Showers and thunderstorms will continue to push east as a cold front moves through, ending everywhere after 8 pm. The severe threat has pushed offshore, therefore the Severe Thunderstorm Watch that was previously in effect was cancelled/expired. Weak shortwaves aloft and at the surface may bring a passing shower across much of the area after midnight, except southwestern Connecticut, with a snowflake possibly mixing in the interior. Winds will continue to be on the strong side, with gusts up to 45 mph expected as the cold front moves through and the surge of cold advection just behind it. Therefore, will continue with the Wind Advisory through 8 pm. Thereafter, winds will diminish, especially in some of the outlying areas where some model soundings show an inversion setting up, which would preclude high wind gusts. Temperatures will drop near normal levels tonight, with lows ranging from the 30s inland to the lower 40s in the New York City metro area. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... On Friday, on the back side of the low that is slowly moving into the Canadian Maritimes, a vort max/shortwaves will be in the vicinity, again giving the area a slight chance for showers, this time mainly across the Lower Hudson Valley and southern Connecticut. The biggest concern on Friday will be the winds that develop as the pressure gradient tightens up. Strong westerly winds will gust 40-45 mph with sustained winds 25-30 mph. A wind advisory may be needed, but because of the uncertainty, did not issue one just yet, but may need to be issued with the overnight forecast. Temperatures will be below normal on Friday, with highs in the upper 40s to lower 50s. && .LONG TERM /SATURDAY THROUGH THURSDAY/... High pressure will strengthen as it moves east Saturday night with the local pressure tendency in the region increasing Saturday night. The high will be moving offshore going into Sunday and will eventually give way to an approaching complex low pressure system approaching from the south and west. The progression of the system will have a warm front passage followed by a cold front passage Monday into Monday evening. Dry weather will prevail Sunday into Sunday evening as the atmospheric column will have to sufficiently moisten before the commencement of rainfall ahead of this system. Rain becomes likely late Sunday night and continues through much of Monday. Heavy rain will be possible Monday morning with the bulk of the rainfall occurring Monday morning into early Monday afternoon. Rain tapers off Monday night. Rain showers a possibility again on Tuesday into Tuesday night with another cold frontal passage. Models show possible stalling of the front offshore heading into Wednesday so another chance of rain showers is forecast Wednesday as well. Temperatures on average are forecast to be a few degrees below normal Friday night through Saturday night, near normal Sunday, above normal Sunday night through Monday night, and closer to normal thereafter. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... Low pres will track away from the area thru Fri. Mainly VFR thru the TAF period. There could be a few brief periods of MVFR or lower in isold-sct shra or shsn, especially on Fri. Coverage and probability are too low to include in the TAFs attm. Strong WNW winds thru the TAF period. Some decrease in strength tngt, then increasing speeds aft 14Z Fri. Peak gusts around 40 kt expected. .OUTLOOK FOR 00Z SATURDAY THROUGH TUESDAY... .Friday night...VFR with WNW winds gradually diminishing to 15-20G25kt. .Saturday...VFR. WNW winds 15G20-25kt. .Sunday...VFR. .Sunday night and Monday...MVFR to IFR in rain. S winds G20-30kt. Chance of LLWS. .Tuesday...Cold fropa with chance mainly afternoon showers/MVFR. W winds G15-20kt. && .MARINE... Gales on all waters today through Friday as low pressure strengthens while.MARINE... Gales on all waters today through Friday. A strong frontal system will pass through the waters today with a strengthening southerly flow this morning, followed by a westerly gale developing in the afternoon. There looks to be short respite for the first half of tonight before gales return to the waters during the early morning hours Friday. A shot of cold air in conjunction with deepening low pressure tracking from northern New England into the Canadian Maritimes Thursday night into Friday will allow gales to continue through Friday evening. SCA gusts for all waters Saturday. Sub-SCA conditions Saturday night into Sunday evening as high pressure moves across the waters. SCA gusts return for all waters late Sunday night with gales on the ocean probable again Monday with rest of waters maintaining SCA gusts. SCA gusts linger into much of Monday night. Ocean seas forecast of 5 to 8 ft Friday night, 3 to 5 ft Saturday morning into early Saturday afternoon. Then below 5 ft ocean seas thereafter through Sunday evening. Ocean seas build back up to near 6 to 11 ft late Sunday night into early next week. && .FIRE WEATHER... Wetting rains today should help limit fire growth potential on Friday despite strong winds and low afternoon RH. With some drying out Saturday, could be a day of concern, with W winds still gusting to 30 mph and minimum RH 20-30%. && .HYDROLOGY... QPF of 1-2 inches Sunday night into Monday could also cause at least minor poor drainage flooding at that time. && .TIDES/COASTAL FLOODING... The combination of spring tides (some places needed less than 1/4 ft of positive tidal departures for minor coastal flooding) and background tidal anomaly will have water levels exceeding minor flood thresholds for vulnerable locations along Western Long Island Sound, the south shore bays of western Long Island, and along NY/NJ harbor. This all despite mostly weak wind/wave forcing. Astronomical tides are about 1/2 ft lower for this mornings high tides, but strengthening SE flow ahead of an approaching frontal system should allow for surge of 1-2 ft to develop, with another round of widespread minor coastal flooding in the aforementioned areas. Timing of peak winds looks to be after high tide farther east, but if stronger winds arrive sooner, minor coastal impacts could occur there as well. Strong offshore flow develops before tonight high tide cycle. Similar to Wednesday nights tide, not much surge needed to reach minor flooding thresholds. Highest threat of minor coastal flooding is along the south shore bays of Long Island, with water slow to exit through the inlets. Elsewhere, a negative surge will likely have water levels falling below minor flood thresholds. Breaking waves likely to build to 4-6 ft today, which will likely cause beach erosion, but dune impacts should be minimal. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO35 (162.55 MHz) is undergoing its final stages of testing, and is operating at full power. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Wind Advisory until 8 PM EDT this evening for CTZ005>012. NY...Wind Advisory until 8 PM EDT this evening for NYZ067>075- 078>081-176>179. Coastal Flood Advisory until 1 AM EDT Friday for NYZ178-179. NJ...Wind Advisory until 8 PM EDT this evening for NJZ002-004-006- 103>108. MARINE...Gale Warning until 6 PM EDT Friday for ANZ330-335-338-340-345- 350-353-355. && $$ SYNOPSIS...JM/JP NEAR TERM...JP SHORT TERM...JP LONG TERM...CB/JM AVIATION... MARINE...JP FIRE WEATHER... HYDROLOGY...CB/Goodman/JP TIDES/COASTAL FLOODING... EQUIPMENT... is the U.S. government's official web portal to all federal, state and local government web resources and services.