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FXUS61 KOKX 181942
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
342 PM EDT Mon Sep 18 2023

.SYNOPSIS...
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A low pressure system impacts the region today as it tracks up the coast. High pressure builds Tuesday and remains in control through Friday before shifting off the New England coast Friday night into the weekend. Low pressure may impact the region Saturday and Sunday.
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&& .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
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Deepening low pressure system just offshore lifts north and east this evening, as an upper trough tracks east into the region. A broad area of steady light rain, mainly north and east of the center, will continue to push into southern New England and out of the local region. Behind it, more intermittent showers persist into early evening until drier air is able to work in tonight. Additional rainfall amounts should largely remain under a quarter inch, except perhaps across southern CT where enhanced jet dynamics with the incoming trough may help overcome the relatively weak mid level lapse rates and produce locally heavy downpours. Temperatures overnight generally bottom out in the 50s, though parts of the urban metro may hang near 60. Followed a blend of NBM and HRRR guidance for this update.
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&& .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
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Drier conditions return into midweek as low pressure exits and high pressure enters. The H5 trough axis overhead early Tuesday lifts north and east, allowing for gradual height increases through Wednesday as ridging builds in. This will lead to a more tranquil pattern the next couple of days. An increased pressure gradient between the departing low and building high will elevate the flow a bit Tuesday. Northwest winds 10 to 15 mph with a few gusts 20 to 25 mph early in the day should lighten by late afternoon. Other than a bit of fair weather cu, sunshine prevails. With the boundary layer mixing to around 800 mb per BUFKIT soundings, temperatures should be around normal for mid September, with highs generally in the mid 70s Tuesday. A similar tale on Wednesday, with surface high pressure to the west maintaining the northerly flow and dry air mass. Abundant sun can be expected with little cloud cover during the afternoon hours.
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&& .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
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There has been no significant change to the long term and have largely followed the NBM during the period. Deterministic models and ensemble means are in good agreement with the larger scale pattern into the upcoming weekend. Ridging aloft will build over the northeast Wednesday night through Friday. As a result, high pressure will be in control with tranquil conditions for the end of the week. At the same time, southern stream energy will undercut the ridge and form a broad trough over the southeast. High pressure both aloft and at the surface begin to shift offshore this weekend. The modeling has continued to trend towards an organized low pressure developing along or off the southeast coast Friday into Saturday. To the north of the low, an inverted trough appears to set up as the surface high moves off the New England coast. The models diverge on the timing, placement, and strength of the aforementioned low pressure. However, trends are beginning to signal that moisture will increase from south to north this weekend. The ensembles show varying solutions with regard to the evolution of the track of the low pressure with some lifting it northward Saturday towards the Middle Atlantic while others hold it near or over the southeast into Sunday. These differences are handled well within the model consensus. PoPs have been increased a bit this weekend, but still remain in the chance category. The NBM probabilities of greater than 1" in any 6 hour period this weekend remain low and less than 10 percent. These values have been similar over the last several cycles. Unsettled conditions are possible this weekend with potential for a soaking, longer duration rainfall event. Temperatures through the period look seasonable, but could end up slightly below average during the upcoming weekend with more clouds and potential rainfall.
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&& .AVIATION /20Z MONDAY THROUGH SATURDAY/...
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An area of low pressure moves through today and east of the region tonight. High pressure builds in on Tuesday. Rain showers continue this afternoon with IFR to MVFR conditions. Another round of heavier showers is possible early this evening with perhaps more IFR visibilities before all rain comes to an end tonight. There could very well be some fluctuation between MVFR and IFR through the early evening. Some occasional brief LIFR will be possible. VFR eventually returns tonight as rain showers taper off from west to east. Winds are near to less than 10 kt. The winds will transition from the E direction this afternoon to a more NW direction going into tonight. Tonight into Tuesday wind speeds increase to near 10-15 kt. A few gusts near 15-20 kt are possible tonight. More frequent gusts to near 20-25 kt are expected on Tuesday, generally in the late morning and afternoon. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... End time of rain showers could be off by 1-2 hours. Timing of end of IFR and MVFR could be off by 1-3 hours. Categories could very well fluctuate between MVFR and IFR before 00Z. OUTLOOK FOR 12Z TUESDAY THROUGH SATURDAY... Tuesday through Friday: VFR. Saturday...MVFR possible with a chance of rain showers. E gusts near 15-20 kt. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90
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&& .MARINE...
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An increasing northwest flow develops tonight behind departing low pressure, and gusts on the ocean waters may be near 25 kt at times. In addition, southeast swells will be increasing from distant Hurricane Nigel, with ocean seas reaching SCA levels. The seas will remain elevated through Tuesday, and possibly into Tuesday evening before lowering. A Small Craft Advisory remains in effect for these waters tonight and Tuesday. Swells could linger into Wednesday, and seas may be near SCA levels east of Moriches Inlet. Winds on the waters should remain below SCA levels Wednesday through Friday. A steepening pressure gradient then brings increasing winds and potential for SCA gusts, especially on the ocean on Saturday. Elevated seas are possible on Thursday with E-SE swells from Nigel. Seas may also become elevated above 5 ft on Saturday to the north of low pressure near the southeast coast. Monitor https:/www.weather.gov/okx/tropical or https:/www.nhc.noaa.gov for the latest NHC forecasts on Hurricane Nigel.
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&& .HYDROLOGY...
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Localized nuisance flooding will be possible in heavier downpours into this evening. No hydrologic impacts are anticipated Tuesday through the end of the week. Uncertainty exists in the timing and amounts of potential rainfall for the upcoming weekend.
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&& .TIDES/COASTAL FLOODING...
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There is a high rip current risk for all Atlantic-facing beaches on Tuesday given 3 to 5 ft swells with 8 to 10 second periods. This should begin to lower on Wednesday, with a moderate risk in place for all beaches.
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&& .OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None. NY...High Risk for Rip Currents from Tuesday morning through Tuesday evening for NYZ075-080-081-178-179. NJ...None. MARINE...Small Craft Advisory until 6 PM EDT Tuesday for ANZ350-353-355.
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&& $$ SYNOPSIS...DR/DS NEAR TERM...DR SHORT TERM...DR LONG TERM...DS AVIATION...JM MARINE...DR/DS HYDROLOGY...DR/DS TIDES/COASTAL FLOODING...DR