Area Forecast Discussion
Issued by NWS Upton, NY

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036 FXUS61 KOKX 230206 AFDOKX Area Forecast Discussion National Weather Service New York NY 1006 PM EDT Sat Jun 22 2024 .SYNOPSIS... A stationary boundary stays north of the area through tonight, and then should begin to lift further north Sunday. A cold front approaches Sunday night and moves through early Monday with high pressure to follow into Tuesday. A cold front passes through late Wednesday night into Thursday. High pressure will then return for Thursday night into Friday. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
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Added some patchy fog for ern areas as well as the river valleys. No other major changes attm. Isold-sct showers and thunderstorms will be around tngt with instability and anomalous humidity in place. Frontal boundary stays locked up north of the area, but close enough to have some forcing impacts, especially across northernmost and northeastern portions of the area. CAMs have had some inconsistencies around whether convection lingers or re-fires up during a portion of the night. Bulk shear should be no more 25-30 kt so not conducive to organized convection, however with multiple weak boundaries around and a very humid air mass where it does not take much to initiate or re-fire and some interaction with any outflow could keep thing going some. It will be a rather warm and muggy night. Also, like last night where rain occurs causing a wet ground there very well may be patches of fog in places. Don`t have this in the forecast as synoptic flow may be a bit stronger than the previous night and may preclude this, but this will need to be monitored. Lows overnight remain well above normal with dew point readings hovering around 70. Therefore no meaningful relief tonight as lows will range from around 70 across a few interior and eastern coastal sections, to the upper 70s across the NYC and portions of the NE NJ metro.
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&& .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... The region should get even more into the warm sector on Sunday as the warm front lifts further to the north. In terms of this stretch of heat and humidity, this should be the most uncomfortable day widespread across the area. Therefore continue heat headlines for one more day, and added So. Nassau, So. New Haven, and So Middlesex as temps just away from the immediate shore should be able to reach 95 heat index criteria for 2 consecutive days this weekend, thus the northern portions of these southern zones are close enough to warrant the advisory. Only far eastern coastal sections look to remain just below heat adv criteria on Sunday. The chances for more widespread and more organized convection increase into Sunday afternoon and evening despite the fact that storm coverage with convective allowing models isn`t all that impressive. There should be better priming of the overall environment as height falls in increase for the afternoon and evening. The winds increase aloft, thus better bulk shear should lead to more organized convection with the primary threat from any storms being strong damaging wind gusts, with hail and an isolated tornado possible but on the lower end of the threat scale. Storm mode will likely be multicell, with a more linear / broken linear mode possible into the evening as forcing increases. A mixed mode of cluster / supercell cannot be ruled out further north across the CWA. Hodograph curvature carves out more storm relative helicity further north on Sunday. SPC has a Slight risk of severe storms for a little more than half the area, with a marginal risk further southeast across the area. Heavy downpours and lightning will be a concern as well with any storms. With the faster flow aloft storms should move along as any localized flash flood threat would be more from repeat / training storms as individual cells should move faster compared to the previous day. With the very high moisture environment with PWATs likely just above 2 inches for much of the area and a warm cloud layer easily above 11 kft instantaneous rainfall rates could be rather high, and a potential issue for the more urban environments in terms of localized flash flooding. Overall the flash flood threat coverage wise appears limited due to the faster nature of the storms, but one or two isolated cases remain a concern. For more on potential hydrologic impacts see the Hydrology section. There is still a good deal of uncertainty for the overnight late Sunday night into early Monday morning. There will be a pre-frontal trough lingering which may serve as a focus for additional convection towards the middle of the night. How much any previous convection has worked over the storm environment will be the determinant as to how much convection can occur during the night. Getting towards early Monday morning the cold front starts to work into western portions of the area. With the humid airmass still in place look for widespread 70s for the low temperatures. During the day Monday with the cold front getting to the east by mid to late morning look for a drier N to NW flow. There should still be a fair amount of cumulus as the cooler air aloft should be in place with the upper level trough axis lagging behind a bit. Dew point readings towards afternoon should get into the lower 60s, and may even lower a bit more into the upper 50s or thereabout with potentially more mixing due to downsloping. It will still be a very warm day, just not as oppressive and heat headlines not anticipated. With the upper level trough axis still lagging behind low end chance PoPs seems prudent with a shower or thundershower possibility through the afternoon. Temperatures in most places should top out well into the 80s in most places due to a land based wind trajectory out of the W and NW. && .LONG TERM /TUESDAY THROUGH SATURDAY/... Key Points: * Temperatures will remain near to just above normal for much of the extended period. * A slow moving frontal system could bring locally heavy rainfall from late day Wednesday into Thursday. There has not been much change to the thinking with the extended forecast for this update, and followed the National Blend of Models closely. Shortwave ridging on Tuesday gives way to a more zonal flow by Wednesday into Thursday. A shortwave trough passes north of the area on Thursday followed by weak ridging again into next weekend. Much of the week looks to remain dry, save for a frontal system that approaches from the west late Wednesday night into Thursday. Modeled PWATS of close to 2" along with a weak steering flow aloft would increase the chances of excessive rainfall for the area as the front passes through the area. Model thermodynamic profiles also look favorable for thunderstorm development; though this may be somewhat limited given the nighttime approach of the system. The front passes Thursday, with a return to drier conditions under high pressure and westerly flow to end the week. High temperatures on Wednesday look to be near 90F across the urban corridor of NYC and NJ and upper 80s elsewhere. With dewpoints in the mid to upper 60s, this will yield heat indices in the mid to upper 90s across the hottest locations. Thereafter, the front passes through and Thursday/Friday are a bit cooler, but still above average, in the mid to upper 80s. Dry weather returns Friday as another high builds into the region. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/...
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High pressure remains across the Western Atlantic as a nearly stationary front lingers north of the region. Mainly VFR this eve, however sct shwrs and tstms will produce mvfr or lower where they occur. The convection generally dissipates everywhere by 3Z or so, although cannot rule out at least isold tstms overnight. Stratus and fog development likely late once again at some terminals, but low confidence in this at NYC terminals and have omitted for now. Conditions improve by late Sunday morning. S or SW flow tngt with speeds generally at or under 10 kt. Strong and gusty winds will be possible in and near tstms. Strengthening flow on Sunday, increasing to near 15G25kt by afternoon. Additional convection is likely in the afternoon or early evening. NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Coverage and timing of tstms tngt highly uncertain so not included in the TAFs. Isold-sct coverage areawide expected thru 6Z. Timing of convection on Sunday could be off by a couple hours. MVFR or lower conditions possible early Sunday AM if low stratus or fog is able to develop. OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY... Sunday night: Showers and thunderstorms likely with MVFR conditions. S-SW wind gusts 20-25 kt along the coast. Monday: MVFR with a chance of showers and thunderstorms. Tuesday: VFR. Wednesday: Mainly VFR. A chance of showers and thunderstorms in the afternoon and at night, with MVFR or lower possible. Thursday: MVFR or lower possible early. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90
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&& .MARINE... SCA on the ocean tngt for seas, and blw criteria elsewhere. By early afternoon Sunday small craft conditions begin to develop for a good portion of the near-shore waters, with perhaps the exception of NY Harbor with gusts 25, to even 30 kts further east. Ocean seas approach 8 ft late Sunday and Sunday night. A cold front approaches Monday night with gusts falling below small craft criteria on the nearshore waters, but seas and gusts slower to subside on the ocean waters. Towards late Monday afternoon and evening seas should eventually subside enough for sub small craft conditions to return to the ocean waters. Winds and seas across all the waters remain below advisory levels Tuesday and Tuesday night. Increasing southerly winds on Wednesday and Wednesday night will allow for conditions on the oceans to approach SCA conditions. && .HYDROLOGY... WPC has a marginal risk of excessive rainfall for most of the area, with a Slight risk across a good portion of CT into this evening. A marginal risk will continue for mainly north and northwest interior portions of the area for Sunday and Sunday night. With a very humid airmass in place any stronger storms could produce heavy rain with isolated local instances of up to a few inches possible in a short time. There is a chance for locally heavy rain from late day Wednesday afternoon into Wednesday night with a front moving through the region. && .TIDES/COASTAL FLOODING... There will be a high rip current risk for both Sunday and Monday for all ocean beaches with higher wave energy approaching the shoreline with a S to SW wind wave on Sunday. The winds becoming more offshore on Monday, but with the high risk continuing. && .CLIMATE... Here are current record high temperatures for Sunday... Sunday, June 23 NYC: 96(1888) LGA: 95(1965) JFK: 94(2010) EWR: 97(1965) ISP: 91(1999) BDR: 91(2010) && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Heat Advisory until 8 PM EDT Sunday for CTZ005>011. NY...Heat Advisory until 8 PM EDT Sunday for NYZ067>075-078-176>179. High Risk for Rip Currents from 6 AM EDT Sunday through Monday evening for NYZ075-080-081-178-179. NJ...Heat Advisory until 8 PM EDT Sunday for NJZ002-004-006-103>108. MARINE...Small Craft Advisory from noon Sunday to midnight EDT Sunday night for ANZ331-332-335-340-345. Small Craft Advisory until 6 AM EDT Monday for ANZ350-353-355. && $$ SYNOPSIS...JE/DBR NEAR TERM...JMC/JE SHORT TERM...JE LONG TERM...DBR AVIATION...JMC/DR MARINE...JMC/JE/DBR HYDROLOGY...JE/DBR TIDES/COASTAL FLOODING... CLIMATE...