000
FXUS61 KOKX 252005
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
405 PM EDT Fri Aug 25 2023

.SYNOPSIS...
-- Changed Discussion --
A slow moving frontal system tracks east through the region into Saturday morning, with secondary cold front moving through Saturday evening. High pressure builds in from the northwest on Sunday and then passes to the north early next week. An offshore frontal boundary northwest of Tropical Cyclone Franklin will then briefly backup toward the east coast Monday and into Tuesday. At the same time, a cold front approaches from the northwest, passing across the area Wednesday morning. High pressure builds in for the end of the week.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
-- Changed Discussion --
Shortwave trough slides east into tonight. The region will be in the warm sector ahead of a broad, weak surface low and attendant cold front. This front should make its way through overnight into early Saturday morning. The ragged band of rain showers aided by the warm front and LLJ has slid east through the day, with the exception of eastern LI and parts of southern CT. Surface instability has nudged up over eastern PA and southern NJ where a bit of clearing has developed in the warm sector, but this has yet to really advance into our neck of the woods. The drier air aloft may work into the region and help to destabilize conditions enough to break the weak cap and allow for additional showers or a few thunderstorms to pop up into the early evening however. With a lack of trigger/focus, more likely is just some isolated shower activity. Far eastern portions of the forecast area may see a bit more expansive coverage of drizzle or showers where a modest 925 mb LLJ remains into tonight. Any shower or thunderstorm could produce locally heavy downpours that lead to nuisance flooding of urban and poor drainage areas this evening, but this threat appears isolated if it were to occur. The steadiest of the activity should finally slide east by daybreak Saturday as surface trough and LLJ slides east, with trailing cold front moving through, with perhaps a few additional showers along it.
-- End Changed Discussion --
&& .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
-- Changed Discussion --
The surface wave pushes offshore Saturday, with the trailing cold front moving through early in the morning. Absent a few spotty showers, especially east, drying conditions can be expected in the wake of this front Sat AM. Cyclonic flow and lingering weak surface troughing should result in sct to bkn cu development by the afternoon. Temps run near seasonable upper 70s to low to mid 80s with offshore flow. A secondary Canadian cold front approaches late in the day, sweeping through in the evening hours. An isolated shower or thunderstorm with the fropa, but a pronounced 750 to 850mb cap should limit any strong or severe threat from this activity, with any showers or thunderstorms brief and limited in coverage. Most remain dry as drier air moves in behind the front as flow turns NNW into Sunday AM. Followed the superblend of guidance for this update, with subtle adjustments.
-- End Changed Discussion --
&& .LONG TERM /SUNDAY THROUGH FRIDAY/...
-- Changed Discussion --
The mean upper trough will remain where it has most of the summer across eastern Canada and into the NE quarter of the CONUS. Periodic shortwave energy traversing the trough will send another frontal system through the area by midweek. Before then though, high pressure builds in from the northwest on Sunday and then to the north across New England on Monday. There could be an isolated shower across the interior Sunday afternoon with the departing shortwave trough, along with a reinforcing shot of cool, dry air into the region. An offshore frontal boundary stalls on Monday and then even backups well north and west of tropical cyclone Franklin, which is forecast to be a hurricane by this time. The system is progged to stay well offshore with no direct impacts. However, some indirect impacts will be dangerous rip currents due to an increasing swell and high surf. As another piece of jet energy dives southward out of eastern Canada, it will amplify the upper trough dropping southeast Great Lakes. The latter of which will send a cold front toward the region. The backing upper flow may allow for some overrunning showers to work in from the Atlantic late Monday into Tuesday. Showers/isolated thunderstorms associated with the cold front will then follow Tuesday night into Wednesday. An easterly flow preceding the front should not allow for too much destabilization of the airmass, with perhaps the exception of areas well north and west of NYC. Behind the frontal boundary look for a continental polar air mass with cooler temperatures and comfortable conditions into the later portion of next week by Thursday. Temperatures overall through the period will average approximately 5 degrees below average, with noticeably lower humidity Wed night into Thursday. Monitor https:/www.weather.gov/okx/tropical for the latest NHC forecasts on this tropical system and others.
-- End Changed Discussion --
&& .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
A warm front remains north of the terminals today with cold front approaching and passing through late tonight into Saturday morning. Mainly MVFR over the next few hours. VFR becoming more likely at the city terminals by around 23z before lowering in category towards midnight. Also some showers possible before midnight, but coverage/duration not high enough to include in TAFs. Better chance of showers and an isolated thunderstorm late tonight into Saturday night ahead and along with the cold front passing through. MVFR/IFR for the overnight hours. Winds will be southerly, generally under 10kt inland and 10-15kt at the coastal terminals. The winds remain S this evening and lighter, before becoming SW later tonight, then NW towards 12z Sat. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Occasional gusts 20-25kt possible at KJFK. Winds at KEWR may vary ENE to SSW through 00z, but at least remain under 10 kt. Chance that VFR does not prevail from 23-04z and is MVFR instead. Prevailing IFR possible late tonight. OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY... Saturday-Sunday: VFR. Monday: VFR, with MVFR/IFR and shra possible late day and nighttime. Tuesday: MVFR or lower in SHRA/TSRA especially in the afternoon and evening. Wednesday: MVFR or lower and shra possible in the morning, otherwise VFR. CHC N-NW gusts 20kt in the afternoon. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
SCA wind gusts on the ocean, southern and eastern bays, and LI Sound should relegate to just the ocean and eastern nearshore waters this evening as the low level jet shifts east. Winds fall below SCA late tonight on all waters. Elevated seas on the ocean may linger near 5 ft into early Saturday afternoon, though it`s possible they could come down earlier in the morning. Sub SCA conditions continue to be favored for Sun into Mon on all waters (although ocean seas may run 3-4 ft in mixed E and SE swell), with high pressure building in. By Monday night into Tuesday look for SE swells to become more energetic with swells likely building further as tropical cyclone Franklin lifts north in the Western Atlantic late Monday into Tuesday. Small craft conditions develop by Tuesday with ocean seas expected to climb to 5 to 8 ft, highest east of Fire Island Inlet Tuesday afternoon and Tuesday night. Seas will then begin to subside Wed into Thu as the Franklin heads up into the North Atlantic.
-- End Changed Discussion --
&& .HYDROLOGY...
-- Changed Discussion --
Spotty showers and thunderstorms through tonight presents a nuisance flood threat of primarily urban and poor drainage areas. Flash flood threat remains low. No hydrological concerns at this time from Sunday through Friday.
-- End Changed Discussion --
&& .TIDES/COASTAL FLOODING...
-- Changed Discussion --
There is a high risk for rip current development through Saturday with 5 ft+ southerly wind waves. Swells from tropical cyclone Franklin will likely build late Monday into Tuesday, continuing into midweek, increasing likelihood for high surf and dangerous rip currents. In addition, a full moon on Wed Night will have astro tides increasing through the mid to late week period. Combined with the high surf, the potential for areas of ocean beach erosion/flooding and scattered areas of dune erosion increases during the times of high tide Tue/Wed.
-- End Changed Discussion --
&& .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...High Risk for Rip Currents through Saturday evening for NYZ075-080- 081-178-179. NJ...None. MARINE...Small Craft Advisory until 2 AM EDT Saturday for ANZ331-332- 340-345. Small Craft Advisory until 8 PM EDT this evening for ANZ335. Small Craft Advisory until 2 PM EDT Saturday for ANZ350-353- 355. && $$ SYNOPSIS...DR/DW NEAR TERM...DR SHORT TERM...DR LONG TERM...DW AVIATION...JC MARINE...DR/DW HYDROLOGY...DR/DW TIDES/COASTAL FLOODING...DW