Area Forecast Discussion
Issued by NWS Upton, NY

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary On
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. --
293 FXUS61 KOKX 252011 AFDOKX Area Forecast Discussion National Weather Service New York NY 411 PM EDT Tue Jun 25 2024 .SYNOPSIS...
-- Changed Discussion --
High pressure builds off the Eastern Seaboard this afternoon into tonight. A warm front moves in late tonight and then moves northeast away from the region early Wednesday. A cold front then approaches from the west, moving across late Wednesday night into early Thursday. High pressure gradually builds in thereafter through Thursday night, becoming centered over the area Friday morning and moving offshore Friday evening. A warm front lifts north of the area Friday night into Saturday, followed by a cold frontal passage sometime on Sunday. High pressure then likely builds in for early next week.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH WEDNESDAY/...
-- Changed Discussion --
Winds expected to become more SW for the latter half of this afternoon and gusty. Clouds are expected to increase into early this evening but plenty of sun is still expected as much of the clouds will be higher level cirrus clouds with some transparency. For tonight, nearly steady zonal mid level height tendency. Vort max moves across during the evening, with most of its energy north of the area. At the surface, high pressure moves farther offshore. A warm front approaches from the west and eventually moves into the region. This warm front is forecast to move northeast of the region early Wednesday. Some CAMs are depicting a few showers potentially developing across parts of the region in and around NYC as well as locations to the north and west. Will only have slight chance POPs for this. Forecast lows tonight were a blend of MOS consensus and NBM, ranging from the upper 60s to lower 70s for a majority of the region. It will start to feel more humid as well as the dewpoints are forecast to rise into the upper 50s to lower 60s.
-- End Changed Discussion --
&& .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY/...
-- Changed Discussion --
On Wednesday, more height falls are forecast at 500mb. A mid level trough approaches from the west. Even stronger height falls are forecast for Wednesday night as the trough eventually moves into the area late Wednesday night. This trough will exit the area early Thursday and shift east of the area Thursday afternoon. At the surface, the warm front will be moving northeast away from the region early Wednesday. The area will be in the warm sector during the day Wednesday. There are model indications of a pre-frontal trough developing during the day but not much convective development along it. This is probably due to mixing down of drier air. Dewpoint depressions of near 25 degrees are forecast, limiting the moisture available for convective initiation. A cold front will be approaching from the west. Chances for showers and thunderstorms begin north and west of NYC in the first half of the afternoon and then in the second half of the afternoon chances for showers and thunderstorms are forecast farther east into NE NJ, NYC, Western Long Island, SW Connecticut. Late afternoon, expecting showers and thunderstorms to become likely north and west of NYC. The cold front eventually moves into the region Wednesday night. Showers become likely ahead of it for Wednesday evening across the entire region. The chance for thunderstorms will remain as well. A note about thunderstorms. There could be strong to severe thunderstorms within the region. SPC has highlighted much of the western half of the region with a slight risk of severe thunderstorms and a marginal risk for severe thunderstorms to the east for the remainder of the region. Models show limited CAPE (near or less than 1000 J/kg) but 40-50 kt of bulk shear 0-6 km AGL. The CAPE becomes elevated Wednesday night, so do expect some maintenance of convection across the coastal sections of the region. Also see hydro section for flooding potential which will have a marginal risk especially for any strong or severe thunderstorms. PWATS are forecast to reach near 2 inches, highest along the coast Wednesday night. For Thursday, the cold front may still be lingering nearby in the morning and will remain across eastern parts of the region. The front moves fully offshore by early afternoon. Chances for showers remain late Wednesday night into Thursday morning. Dry conditions expected to return for the whole forecast region Thursday afternoon. Regarding temperatures, SW winds tonight into Wednesday with warm air advection. Warmer night is expected tonight compared to previous night with more humid conditions. Highs forecast Wednesday will be relatively similar to those of the previous day with some more humidity but will be a few degrees cooler along the coast. Only have max heat indices getting to lower 90s within NYC and part of NE NJ into the mid 90s. Overall, the entire forecast region is expected to stay below heat advisory criteria. Highs forecast more in the 80s for Thursday with drier conditions as dewpoints drop into upper 50s to lower 60s.
-- End Changed Discussion --
&& .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
-- Changed Discussion --
High pressure starts to build in Thursday night as heights rise aloft in a zonal flow. The airmass that will build in will bring drier and a bit cooler conditions to the area. Friday looks to be the pick of the long term. High pressure moves overhead early in the day and then offshore by the evening. This will lead to sunny and dry conditions, with high temperatures potentially a few degrees below normal for late June. Dewpoints in the low 50s will give a comfortable feel to the air. By Friday evening, the synoptic surface flow will become southerly (outside of any areas that will already be in a southerly flow from seabreezes) in response to the high moving offshore. A warm front looks to move through sometime later Friday night into Saturday morning. This will start to bring in warm and moist air ahead of the next cold frontal passage. Between a pre-frontal trough and a slower moving cold front, chances for showers and thunderstorms last from Saturday afternoon through Sunday night. At this time there are no hydrologic issues expected, but it is worth nothing that pwats look to be between 2.25 and 2.5 inches. In this environment, any shower or thunderstorm will likely be able to produce heavy downpours. The front pushes through sometime on Sunday and then high pressure looks to build in for the beginning of next week leading to dry conditions.
-- End Changed Discussion --
&& .AVIATION /20Z TUESDAY THROUGH SUNDAY/... A warm front lifts north of the area tonight as a cold front approaches Wednesday night. VFR. SW winds 10-15 kt at the metro terminals, and around 10 kt at all other terminals. Gusts to 25 kt possible through early evening mainly at the coast. All other terminals may see occasional gusts to 20 kt. Winds diminish tonight and increase again Wed afternoon. PROB30 for TS introduced at 30 hr terminals Wed in vicinity of pre-frontal trof. However, most activity may hold off until 00z or after. Best chance of Wed afternoon convection will be city terminals and areas to N and W. Any TSRA that develops may contain strong gusty winds or hail. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... No unscheduled amendments are expected. OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY... 18z Wednesday: Mainly VFR. A chance of showers and thunderstorms in the late afternoon, and likely at night, with MVFR or lower possible. SW wind 15-20 kt G20-25 kt near the coast. Thursday: Mainly VFR, MVFR or lower possible early in the morning in shower and thunderstorms. Friday: VFR. Saturday: VFR with a chance of thunderstorms in the afternoon. Sunday...MVFR possible in a chance of shra and tstms. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE...
-- Changed Discussion --
Small craft advisory, SCA, remains in effect for the ocean zones south of Long Island 6PM tonight through Wednesday night. Decided to add in South Shore Bays with SCA. The South Shore Bays have SCA from 8PM tonight until 10PM Wednesday night. Already starting to have Ambrose jet form along western ocean zone and more gusty SW flow is expected to continue through tonight including the South Shore Bays. There may be some 25 kt gusts farther north for other non-ocean zones as well for tonight through Wednesday evening but those will probably just be occasional. Late Wednesday night, SCA conditions will just remain on the ocean with non-ocean waters expected to have below SCA conditions. SCA conditions could linger into Thursday on the ocean, mainly due to seas, but otherwise would expect conditions to become below SCA. Winds and waves generally remain below SCA criteria from Thursday night through early next week. However, there is the potential for SCA winds Saturday afternoon through early Sunday as the pressure gradient increases across the waters ahead of a cold frontal passage. Wind gusts could reach 25 kt on all waters and waves could reach 5 ft on the ocean waters. Conditions then likely lower for the start of next week.
-- End Changed Discussion --
&& .HYDROLOGY...
-- Changed Discussion --
Around 0.5 to 1 inch of rain forecast Wednesday afternoon through Thursday morning. Marginal risk of flooding, especially Wednesday night, and for poor drainage and low lying areas within any potentially strong to severe thunderstorms. At this time, there are no hydrologic concerns Thursday night through early next week.
-- End Changed Discussion --
&& .TIDES/COASTAL FLOODING...
-- Changed Discussion --
There is a high rip current risk at all local Atlantic facing beaches today through Wednesday evening.
-- End Changed Discussion --
&& .OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None. NY...High Risk for Rip Currents through Wednesday evening for NYZ075-080- 081-178-179. NJ...None. MARINE...Small Craft Advisory from 8 PM this evening to 10 PM EDT Wednesday for ANZ345. Small Craft Advisory until 6 AM EDT Thursday for ANZ350-353-355.
-- End Changed Discussion --
&& $$ SYNOPSIS...JM/JT NEAR TERM...JM SHORT TERM...JM LONG TERM...JT AVIATION...IRD MARINE...JM/JT HYDROLOGY...JM/JT TIDES/COASTAL FLOODING...