Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 272119 AFDOKX Area Forecast Discussion National Weather Service New York NY 519 PM EDT Sun May 27 2018 .SYNOPSIS... A stationary front will remain south of the area through tonight as a wave of low pressure tracks along the boundary. Meanwhile, high pressure builds in from coastal New England. The high weakens Memorial Day and remains in the region Monday night. A backdoor frontal passage will occur on Tuesday, allowing high pressure to build in through the middle of the week. The remnants of Alberto may then impact the region into the weekend. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... Nely winds were increased along the coasts. Otherwise, the fcst is on track. A stationary front remains across southern New Jersey and south of Long Island tonight as a developing wave of low pressure east of the NJ coast tracks east. Meanwhile, an upper trough tracks through the northeast with weak vort maxes moving through the flow. Will keep chance and slight chance probabilities through tonight, however, upper levels have been drying and precipitation will be light, and possibly more drizzle. And with weak height rises to the west and north late tonight will taper and end precipitation chances. A northwest flow will remain through tonight with cloud cover and temperatures will not drop off that much. There is a high risk of rip current development at the ocean beaches through early this evening, and a moderate risk on Mon. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... The upper shortwave will be moving east with heights slowly rising monday morning. Light precipitation will be ending, however, would not be surprised if precipitation shuts off below 10Z. A northwest flow will persist. Temperatures will rebound Monday, but remain below seasonal normals. The western portion of the stationary front will be pushed east and north as a warm front, mainly across upstate NY, Monday into Monday afternoon, as an upper trough remains across eastern Canada into New England. The front will be weak with little forcing. The GFS is more aggressive with bringing precipitation to near the Lower Hudson Valley by late in the day. Will leave dry at this time, however, there is a chance of a few showers to develop as instability increases with 100-200 J/kg of CAPE. Monday night will be dry, with light winds. With low level moisture in place all guidance is indicating potential for fog to develop, possibly becoming dense along the coast late Monday night. At this time will mention patchy 2 mile fog restrictions. && .LONG TERM /TUESDAY THROUGH SUNDAY/... Little change in the long term as the models remain in good agreement. A weak backdoor front comes thru on Tue. The NAM is dry, the GFS and ECMWF suggest something in the isold to perhaps sct category w of the Hudson late in the day. The model qpf may be a grid scale issue, with the center of any progged convection centered s and w of the cwa. A dry fcst has been maintained. The warmer Superblend was used for high temps. Hipres for Wed with fair wx. The NBM was used for temps, which resulted in a slight increase in the fcst highs. The remnants of Alberto are progged to travel roughly up the MS Valley on Wed, merging with the upr low which is currently spinning near Salt Lake City. This eventual hybrid sys slowly tracks thru the region Fri-Sun. Mid lvl moisture transport into the region could support some isold-sct shwrs and tstms on Thu, then the main sys could produce better chcs thru Sun. Right now, the best dynamics remain generally n of the cwa, although the timing and position of these features are highly uncertain this far out, especially concerning Alberto in the mix. As a result, the fcst maintains only slgt chc pops for Thu, low chc (30 percent) for Fri and Sat, and slgt chc again on Sun. The NBM was used for temps, which again resulted in an increase in highs Thu-Sat. && .AVIATION /21Z SUNDAY THROUGH FRIDAY/... High pressure will begin to build into the area from the northeast tonight into tomorrow. Although conditions are predominantly IFR with occasional drizzle and mist at this time, the drier air associated with the building high will allow for a gradual improvement to MVFR- VFR by tomorrow afternoon. Due to lingering moisture in the meantime, a few sites, especially KGON and KISP may see reductions in visibilities due to fog and drizzle for the early portion of the night, before improving by morning. There is less confidence in the wind forecast. Occasional improvements in the ceilings may allow for a few stronger gusts in the 20-25 kt range to mix to the surface, particularly at the city airports and KGON/KISP. Expect flow to gradually decrease overnight into the morning in response to the building high, and as low pressure departs the area. NE-E flow will generally shift to a more SW-SSE direction by tomorrow afternoon. .OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY... .Monday...MVFR cigs expected in the morning, then VFR. .Tuesday-Wednesday...VFR. .Thursday...Mainly VFR. MVFR or lower possible late. .Friday...MVFR or lower in -SHRA. Isold TS possible. && .MARINE... A developing wave of low pressure along a stationary front south of the forecast waters in combination with building high pressure along coastal New England have resulted in an increased, and gusty, NE to E flow, especially across the ocean waters. A strong pressure gradient force will continue through much of tonight as the wave of low pressure tracks to the east. Will continue with the SCAs for the ocean waters through tonight, and for the eastern Long Island Sound and eastern bays through this evening. A sca has also been issued til midnight for the wrn Sound and s shore bays. High pressure will build late tonight into Monday and remain into Monday night. A weaker pressure gradient force will then be across the forecast waters. Winds and seas will remain below SCA levels Monday and Monday night. Winds and waves are expected to remain blw sca lvls Tue-Fri. Conditions may deteriorate next weekend. && .HYDROLOGY... No hydrologic impacts are anticipated through Thu. There is a low potential for locally heavy rain Fri-Sun depending on the timing and placement of Alberto remnants. && .TIDES/COASTAL FLOODING... A strong E-NE flow and high celestial tides with the upcoming full moon Tue morning combine to push water levels right up to minor coastal flooding thresholds along the south shore back bays of southern Nassau and southern Queens counties with this evening`s high tide cycle. Believe the western Long Island Sound falls just short. A coastal flood statement has been issued. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) is off the air for an extended period of time. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...High Rip Current Risk until 9 PM EDT this evening for NYZ075- 080-081-178-179. NJ...None. MARINE...Small Craft Advisory until midnight EDT tonight for ANZ330-335- 340-345. Small Craft Advisory until 6 AM EDT Monday for ANZ350-353-355. && $$ SYNOPSIS...12/19 NEAR TERM...12/19 SHORT TERM...19 LONG TERM...12 AVIATION...MD MARINE...12/19 HYDROLOGY...12/19 TIDES/COASTAL FLOODING... EQUIPMENT...

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