Area Forecast Discussion
Issued by NWS Upton, NY

Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
120 FXUS61 KOKX 200735 AFDOKX Area Forecast Discussion National Weather Service New York NY 335 AM EDT Fri Sep 20 2024 .SYNOPSIS...
-- Changed Discussion --
Low pressure remains south and east of the Long Island through through Saturday before slowly pushing farther offshore Sunday into early next week. At the same time, high pressure noses in from the northeast into Monday and remains in control through Tuesday. A frontal system approaches mid to late next week.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
A rather persistent weather pattern will continue into the weekend across the northeast. Low pressure will linger south and east of Long Island with high pressure slowly ridging southwest out of southeast Canada. Most of the region will remain dry through tonight. The east end of Long Island and southeast Connecticut could see a few showers on the northwest side of the offshore low, but so far any activity has had a hard time making it this far west. The chance could be slightly higher tonight as some upper level energy pivots west around the associated upper low. The thickest cloud cover should also remain across eastern Long Island and southeast Connecticut with partly cloudy conditions further west towards the NYC metro, NE NJ, and Lower Hudson Valley. Highs today across much of the area will be in the middle to upper 70s except out east where highs will be in the upper 60s and low 70s. A few 80 degree readings are not out of the question in the NYC metro. Some slightly cooler air begins to advect in from the north tonight with lows falling into the middle to upper 50s for most spots.
-- End Changed Discussion --
&& .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
-- Changed Discussion --
Low pressure will continue to spin south and east of Long Island on Saturday. The associated upper low remains nearly stationary as well, but should begin to open up in the afternoon/evening as it interacts with upper level energy from the Great Lakes. This interaction should ultimately begin the process of moving the upper trough axis further offshore Saturday night and Sunday. As a result, the surface low will slowly move further offshore. High pressure will continue ridging down from southeast Canada on Saturday, but will become more dominant on Sunday. The chance for a few showers will remain across the east end of Long Island and southeast Connecticut on Saturday. Its beginning to look like the bulk of any showers will remain closer to Cape Cod, but did not want to completely remove PoPs yet as the modeling continues to struggle resolving if this precip can make it as far west as New London and the Twin Forks. Otherwise, it will remain dry for the rest of the area with partly to mostly cloudy skies. The interaction with the upper level energy from the Great Lakes will likely increase cloud cover a bit areawide in the afternoon and evening. Highs should be a bit cooler on Saturday with highs in the upper 60s and low 70s east and middle to upper 70s west, especially NYC metro and NE NJ. Conditions will improve further Saturday night into Sunday with the high pressure building further south and the offshore low moving further away from the coast. Dry conditions are expected with highs near seasonable levels in the lower to middle 70s. With cooler and drier air over the region, temperatures Sunday night look to fall into the upper 40s inland and lower to middle 50s elsewhere.
-- End Changed Discussion --
&& .LONG TERM /MONDAY THROUGH THURSDAY/...
-- Changed Discussion --
No major changes made to the long term Monday through Thursday with the NBM used for the forecast. *Key Points* *Dry conditions Monday and Tuesday transition to potential of showers mid to late week with an approaching frontal system. *Temperatures will likely end up slightly below normal. Upper ridge axis slides over the area on Monday with surface high pressure over New England. The ridge flattens by Tuesday with guidance signaling a shortwave passing well to our north and west on Tuesday. Dry conditions are generally expected Monday and Tuesday. There will likely be mostly cloudy conditions late Monday and continuing into Tuesday with SW flow aloft. There may also be a passing shower well inland late Tuesday and Tuesday night. The chance for showers slowly spreads across the rest of the area Wednesday into Thursday as a larger upper trough and associated frontal system slowly approach from the west. The global deterministic and ensemble guidance are in disagreement on the overall evolution of trough as it nears the coast during this time frame. See no reason to sway from the model consensus on PoPs overall, but capped them off at chance for now given this is a Day 6- 7 forecast. Highs will mainly be in the the upper 60s and low 70s this week with nighttime temperatures in the 50s. Some moderation is possible late in the week.
-- End Changed Discussion --
&& .AVIATION /08Z FRIDAY THROUGH TUESDAY/... Low pressure remains offshore, east of Long Island through the TAF period. VFR, except for eastern terminals at times, with KGON going MVFR overnight and into this morning, and perhaps into early the afternoon. KISP and KBDR may briefly experience MVFR ceilings for early Friday morning. KGON will have another period of MVFR Friday night. Winds will be mainly NE and around 7-10 kt for most terminals overnight, with a few inland terminals closer to 5 kt. KGON however is expected to have gusts up to 20 kt overnight. NE winds pick up again for all terminals with gusts resuming by 14 to 15z Friday for most terminals with sustained winds 10-15 kt, and g17-25 kt. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Confidence remains high with wind direction into Friday. Amendments may be needed for KEWR and KTEB for Friday where wind gusts may be more occasional. OUTLOOK FOR 06Z SATURDAY THROUGH TUESDAY... Late Friday night: Mainly VFR, pockets of MVFR possible east. Saturday: VFR. MVFR east of the NYC terminals in possible showers, but low chance of occurring. NE gusts around 15-25 kt possible, highest gusts east. Sunday: VFR. NE gusts 15-25 kt possible, highest gusts east. Monday...VFR. Tuesday..Mainly VFR, with pockets of MVFR possible. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE...
-- Changed Discussion --
Small craft advisories have been extended on the ocean waters through Saturday night, and will likely need to be expanded into early next week as a persistent N-NE flow keep seas elevated above 5 ft. SCA winds will be a little more challenging to reach, but are more likely around Moriches Inlet on east with some gusts to 25 kt. Winds on the non-ocean should largely remain below SCA levels into early next week. However, there is a window this afternoon and evening on the Long Island Sound east of the mouth of the CT River and E LI Bays for winds around 25 kt. Have therefore issued an SCA this afternoon and evening. Winds on the ocean should start to weaken Saturday night into Sunday and remain below SCA levels into early next week.
-- End Changed Discussion --
&& .HYDROLOGY... There are no hydrologic issues through the middle of next week. && .TIDES/COASTAL FLOODING...
-- Changed Discussion --
Multiple rounds of coastal flooding are expected through this weekend with low pressure to the southeast slowly drifting farther out into the western Atlantic. This will result in a building easterly swell that will help to pile water into the area in conjunction with high astronomical tides. Northerly winds will also develop more of an easterly component the second half of the weekend which will contribute to the wind forcing component of the surge. Surge forecast is generally 1 1/2 to 2 1/2 ft with the highest of the tides being during the morning into afternoon high tide cycles. This results in locations adjacent to western LI Sound and the south shore bays of western LI getting to around moderate benchmarks Friday with widespread minor elsewhere. Thus, there are coastal flood warnings for those moderate locations and advisories elsewhere. There is also the potential for another round of moderate coastal flooding Saturday morning for southern Nassau, southern Queens, and SW Suffolk, where a coastal flood watch in in effect. Most other locations will likely see minor flooding continuing. The threat gradually lessens Sunday into Monday with any moderate flooding expected to be more localized. Astronomical levels will also be on the downswing. In addition, due to the building easterly swell there is a high rip current risk through Saturday, which will likely need to be extended into Sunday.
-- End Changed Discussion --
&& .OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Coastal Flood Warning from noon today to 4 PM EDT this afternoon for CTZ009. Coastal Flood Advisory from 11 AM this morning to 3 PM EDT this afternoon for CTZ010>012. NY...Coastal Flood Warning from noon today to 4 PM EDT this afternoon for NYZ071-073-177. Coastal Flood Advisory from 11 AM this morning to 3 PM EDT this afternoon for NYZ078>081. Coastal Flood Advisory from 9 AM this morning to 1 PM EDT this afternoon for NYZ072-074-075. High Risk for Rip Currents through Saturday evening for NYZ075-080- 081-178-179. Coastal Flood Watch from Saturday morning through Saturday afternoon for NYZ080-178-179. Coastal Flood Advisory from noon today to 4 PM EDT this afternoon for NYZ176. Coastal Flood Warning from 9 AM this morning to 1 PM EDT this afternoon for NYZ178-179. NJ...Coastal Flood Advisory from 9 AM this morning to 1 PM EDT this afternoon for NJZ006-106-108. MARINE...Small Craft Advisory from noon today to 11 PM EDT this evening for ANZ332-340. Small Craft Advisory until 6 AM EDT Sunday for ANZ350-353-355.
-- End Changed Discussion --
&& $$ SYNOPSIS...DS NEAR TERM...DS SHORT TERM...DS LONG TERM...DS AVIATION...JM MARINE...DS HYDROLOGY...DS TIDES/COASTAL FLOODING...