000 FXUS61 KOKX 162020 AFDOKX Area Forecast Discussion National Weather Service New York NY 420 PM EDT Sat Oct 16 2021 .SYNOPSIS... A strong cold front will pass through the area through during the late afternoon and early evening hours. High pressure over the Southeast will gradually build into the region through the middle of the week. A strong cold frontal passage is possible on Friday. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... A strong negatively tilting upper trough will approach this evening. At the surface, a cold front, entering W Orange County as of 4pm, will trek east across the Tri-State during the early evening hours. Southerly gusts of 30-40 mph will continue along the coastal plain into early this evening, shifting NW at the same speed behind the cold front for a brief time. Forecast remains on track, with a low topped fine line of convection entering W Orange County and western NJ. So far, this fine line is mainly producing wind gusts of 35 to 45 mph, but will be monitoring the radar and environmental trends over the next hour or so as it moves through NE NJ and Lower Hud for any strengthening cells as the line moves through the strongly deep- layer sheared but weak instability environment. Primary threat looks to be widespread 35 to 45 mph wind gusts, with localized wind gusts up to 50 mph with any stronger cells for NYC metro, NE NJ and Lower Hud. This could cause some minor tree damage with the line. The threat for severe thunderstorms, with damaging wind gusts, appears to be low and localized, mainly west of the Hudson. There is a very low, but non-zero threat for a brief and weak tornado for this area, typical of these high shear/low cape fine line events. Any thunderstorm activity and gust front should weakens as it crosses east of the NYC/NJ metro, into coastal areas. But wind gusts to 40 mph are still possible with passage of the gusts front. Cold front/guts front should pass east of the region by around 10pm, but post- frontal showers in response to approaching trough axis and with mid level jet dynamics, will be slow to ending from w to e until between 10pm and 4am. Drying conditions expected late tonight with gusts NW winds bringing i the coolest airmass of the early fall season. Lows falling to near seasonable by Sunday morning with upper 40s far interior, to the lower and mid 50s at the coast. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... Deep troughing under the negatively tilting upper trough pivoting through the Northeast US Sunday into Sunday Night. Afternoon some morning breaks of sun, steep daytime lapse rates with the cold pool aloft and deep cyclonic flow will result in considerable afternoon cloudiness, and isolated to scattered afternoon showers and/or sprinkles. Gutsy W/NW winds to 20 to 30 mph will prevail on Sunday, relaxing Sunday Night. A chilly feel to the day with highs near seasonable in the lower to mid 60s, but with limited sunshine and breeze. Clearing skies and subsiding winds Sunday Night with loss of diurnal instability. Appears to be enough mixing to keep temps near seasonable, around 50 for city/coast, and 40s Interior. Any interior valley areas that are able to decouple could drop into the 30s. && .LONG TERM /MONDAY THROUGH SATURDAY/... The models have been relatively consistent the last few days and no big changes to the pattern are expected in the long term. The cold pool aloft along with some additional moisture from the Great Lakes will result in increasing high based low clouds on Mon with the chance for a few sprinkles or shwrs. NBM pops are still dry across the cwa, but inserted sprinkles into the fcst nonetheless. Also had to deviate from the NBM regarding cloud cover, as the model was producing mostly sunny skies. It will likely be mostly sunny to start, but the blossoming of the cu field should produce bkn-ovc skies by the aftn. The clouds should dissipate in the eve as the instability wanes. Good agreement model-wise Tue-Thu. The fcst has been kept dry and the NBM was used as high pres over the sern conus builds into the area. Chances for shwrs introduced Thu ngt and Fri as a frontal sys impacts the area. The fropa looks to be Fri per the 12Z GFS and ECMWF. The ECMWF isn't as cold as the GFS behind the front, so there is some uncertainty wrt how cold it gets next weekend. Trended the fcst towards the colder MEX guidance however, as the output is still warmer than what would occur if the 12Z GFS verified, and the GFS has been persistent in modeling a quick shot of cold air into the region. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... A cold front, through eastern upstate New York, and moving into eastern Pennsylvania at 17Z, will move through the terminals this evening, from around 22Z west to 03Z east. Thunderstorms will be possible ahead of the front with showers lingering behind the front for a few hours. High pressure begins to build toward the area late tonight into Sunday morning. VFR through much of the period, except MVFR ceilings along portions of the Connecticut and Long Island coasts, that may lift to VFR late this afternoon. Brief MVFR conditions, possibly IFR, are likely with any thunderstorms. S winds 10-20 kt with gusts upwards of 25-30 kt, with the highest potential along coastal terminals, and during the afternoon. Winds shift to the W to NW with the frontal passage with gusts remaining through this evening at the NYC metro area terminals. Winds remain from the west to northwest through the end of the forecast period. There may be occasional gusts developing Sunday morning. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Highest wind gusts this afternoon are expected at KJFK with southerly winds sustained at 15 to 20 kt with gusts at times 30 to 35 kt. A line of showers and thunderstorms will move through late this afternoon which could bring wind gusts of around 35 kt. However this line is expected to weaken as it approaches and moves through the metro terminals, so there is uncertainty as to how high the winds become, and how strong the thunderstorms will be. Expect thunderstorms to be through the metro area by 00Z Sunday. .OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY... .Sunday afternoon - Monday...VFR. W to NW winds gusting around 20 kt mainly daytime/eve possible. .Tuesday - Thursday...VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... SCA remains in effect for all waters this afternoon into this evening with southerly gusts of 25-30 kt and occasional gusts to 35 kt, especially nearshore. These winds speeds will continue for a brief period immediately in wake of cold frontal passage this evening from the NW. Winds on the non-ocean waters should weaken to 20 kt later this evening behind the cold front, but 25 kt gusts are still likely on the ocean through late tonight. Seas will gradually subside below 5 ft late tonight into early Sun morning. WNW flow will continue Mon and Tue. A sca may be needed, especially on the ocean. All waters expected to remain blw sca lvls Wed attm with high pres building in. Sly flow increases on Thu ahead of a cold front. A sca may be needed. && .HYDROLOGY... Average rainfall late this afternoon and evening is one quarter to one half inch. The HREF max rainfall potential is between 3/4 to 1 1/4 inch of rain well NW of NYC, so localized minor issues cannot be ruled out. No flash flooding is expected due to the progressive nature of the system. Otherwise, no hydrologic impacts are expected through next week. && .CLIMATE... Temperatures today have been unseasonably warm, but should stay shy of these record highs: Sat 10/16 EWR: 86/1956 BDR: 80/1975 NYC: 84/1956 LGA: 82/1958 JFK: 79/2008 ISP: 80/1963 && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 2 AM EDT Sunday for ANZ331-332-335- 338-340-345. Small Craft Advisory until 8 AM EDT Sunday for ANZ350-353-355. && $$ SYNOPSIS...JMC/NV NEAR TERM...NV SHORT TERM...NV LONG TERM...JMC AVIATION...MET MARINE...JMC/NV HYDROLOGY...JMC/NV CLIMATE...