FXUS61 KOKX 180605 AFDOKX Area Forecast Discussion National Weather Service New York NY 205 AM EDT Mon May 18 2026 .WHAT HAS CHANGED... Air quality alerts in effect for portions of the region on Monday. Otherwise, no other significant changes. && .KEY MESSAGES... 1) Summerlike temperatures through Wednesday 2) A cold front moves across Wednesday bringing showers and thunderstorms. Brief gusty winds and locally heavy rain possible. 3) Much cooler airmass expected Thursday into the holiday weekend. 4) Cold water safety concerns continue this weekend with good boating weather, and water temperatures still in the lower 50s. && .DISCUSSION... .KEY MESSAGE 1... A weak back door cold front approaches the region tonight as high pressure moves southeast across coastal New England. Overall, a weak pressure gradient is in place. Winds will become light and variable in direction. Then on Monday, this front moves back east of the region. Winds become more southeast on Monday with some gusts along the coast. Mid level ridging increases tonight into Monday. The subsidence is expected to keep dry weather conditions and not much in the way of cloud coverage. The temperature differences across the region will be more apparent on Monday due to the back door cold front. Locations farther east will be cooler with more onshore maritime influence (highs in the 70s) while locations to the north and west of NYC will be some of the warmest relatively (highs in the upper 80s to near 90). The 850mb temperatures do show a remarkable increase amongst the numerical weather prediction models, going up near 3 to 4 degrees C during the day Monday. The local area gets more into the warm sector Monday night through Tuesday night. Tuesday, the models show another degree warmth in 850mb temperatures. For the whole area, much warmer temperatures expected Tuesday compared to Monday. With dewpoints not changing much from the previous day, the apparent temperatures will likewise increase as well. This is looking to be the warmest day of the week with highest heat indices as well. Forecast high temperatures are ranging from the mid 80s to mid 90s with heat indices right near the actual temperature with some locations about a degree higher than the actual temperature. No locations are forecast to reach 100 degrees temperature. The blend of temperatures was from MOS consensus and NBM. NBM alone seemed too high but after noting the relatively greater warmth of ECMWF and Canadian 850mb temperatures, did not want to lower temperatures too much. May be an isolated shower or thunderstorm late Tuesday into Tuesday evening with the instability and potential surface trough development. Otherwise, weather remains mainly dry. .KEY MESSAGE 2... Mid level heights lower more during the day Wednesday with more cooling apparent in the models 850mb fields Wednesday afternoon into early Wednesday evening. The numerical weather prediction models continue to show a quicker trend to the movement of the cold front with even the 12Z Sunday NAM showing the cold front moving across much of the area by 5PM Wednesday. With the front moving through during the afternoon hours and being south of the region by the start of the evening, this will really limit the daytime warmth and therefore the instability that will enhance thunderstorm activity. Chances of thunderstorms for western half of the region with warmer temperatures forecast, slight chance of thunderstorms for eastern half of the region with cooler temperatures forecast. The bulk shear 0-6 km AGL forecast values of near 30-40 kt could very well overcome that lack of instability and allow for some stronger thunderstorms which would bring some brief strong gusty winds and a quick period of heavy rain. Not too concernedwith flooding potential because of the rapid movement expected of the front and associated showers and thunderstorms. Flow aloft has more westerly component instead of southerly component. Severe thunderstorm potential seems to be marginal with this kind of environment. The high temperatures on Wednesday were lowered from NBM by also blending with MOS consensus, mainly near 80 to 90 degree range. Would expect these temperatures to be set by early afternoon and then start declining with the showers and thunderstorms as well as the cooler air advecting in behind the cold front. .KEY MESSAGE 3... Mid level ridge suppressed for late week into the holiday weekend. At the surface, high pressure moves in from the Great Lakes Thursday but then moves northward into Northern New England and eventually the Canadian Maritimes Friday into the holiday weekend. Max temperatures forecast decrease by near 15 to 20 degrees for Thursday compared to the previous day. Max temperatures are in the upper 60s to lower 70s Thursday. Cooling trend continues Friday with high temperatures forecast mainly in the mid to upper 60s and then just low to mid 60s for most locations on Saturday. Overall, the low level flow will become more easterly. Along with that aside from Thursday and Friday which are forecast to be mainly dry, there will be an increasing chance of showers heading into the holiday weekend with high pressure getting farther away and low pressure approaching from the south and west. .KEY MESSAGE 4... Cold water safety concerns today as water temperatures remain in the 50s. The cold water temperatures can quickly cause hypothermia and physical incapacitation to anyone suddenly immersed in the water. Anyone going out on small boats, canoes or kayaks should plan accordingly and use extreme caution to avoid this threat. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... Weak high pressure over the area early this morning will give way to weak backdoor cold front dropping down along the New England coast and into the area later this morning. The front will quickly lift back to north as warm front later in the afternoon. VFR through the TAF period. Light winds overnight will vary from SW to variable, becoming E/SE during the morning hours, mainly after 09Z. Winds will gradually veer to a more southerly direction late morning into the afternoon, increasing to around 10kt with a some locations G15-18kt. KLGA is expected to be NE-ENE during the morning and early afternoon hours before veering to more southerly flow. KBDR also could hang on to an E wind into the afternoon, ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Gusts may be more occasional Monday afternoon. Winds may also be more to the left of the current forecast Monday afternoon. This will depend on how much the area can heat up to mix down a more SSW direction. .OUTLOOK FOR 06Z TUESDAY THROUGH FRIDAY... Late Monday Night: VFR. Tuesday: VFR. S/SW winds 10-15g20-25kt into eve. Isolated thunderstorm potential afternoon into early eve, mainly north of NYC terminals with brief MVFR or lower possible. Wednesday: VFR, giving way to possible MVFR or lower with potential showers and thunderstorms. Showers likely afternoon into eve with a chance of thunderstorms. S/SW winds 10-15g20-25kt day into eve. Peak gusts to near 30 kt possible. NW windshift in the evening. Thursday-Friday: MVFR or lower possible with a chance of showers. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... Sub-SCA conditions remain on the waters through Monday night. Next chance for SCA will be Tuesday into Tuesday night with increasing southerly flow and fetch, mainly on the ocean. Marginal SCAconditions possible on Wednesday into Wednesday evening with otherwise conditions forecast to be below SCA thereafter through Friday. Cold water safety concerns today as water temperatures remain in the 50s. The cold water temperatures can quickly cause hypothermia and physical incapacitation to anyone suddenly immersed in the water. Anyone going out on small boats, canoes or kayaks should plan accordingly and use extreme caution to avoid this threat. && .CLIMATE... Record High Temperatures: May 19: KEWR: 98/1962 KBDR: 89/2017 KNYC: 99/1962 KLGA: 96/2017 KJFK: 92/2017 KISP: 89/2017 Record High Minimum Temperatures: May 17: KEWR: 68/2015 KBDR: 60/2025 KNYC: 70/1906 KLGA: 68/1965 KJFK: 63/1965 KISP: 62/2015 May 18: KEWR: 74/2017 KBDR: 66/2017 KNYC: 75/2017 KLGA: 80/2017 KJFK: 65/2017 KISP: 63/1977 May 19: KEWR: 67/1986 KBDR: 66/2017 KNYC: 68/1986 KLGA: 68/2017 KJFK: 67/2017 KISP: 65/2017 May 20: KEWR: 72/1996 KBDR: 61/2019 KNYC: 74/1996 KLGA: 77/1996 KJFK: 63/1996 KISP: 62/1996 && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...Air Quality Alert from 11 AM this morning to 11 PM EDT this evening for NYZ069>075-176-178. NJ...None. MARINE...None. && $$ DISCUSSION...JM AVIATION...DW MARINE...JM