Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 230225 AFDOKX Area Forecast Discussion National Weather Service New York NY 1025 PM EDT Fri Sep 22 2017 .SYNOPSIS... Post Tropical Cyclone Jose will meander and weaken to the southeast of Long Island through Saturday night as high pressure remains centered over the eastern Great Lakes, and extends into the northeast, into the beginning of next week. Meanwhile, Hurricane Maria tracks well offshore of the east coast. A cold front passes through the region Wednesday night into Thursday. High pressure builds to the northwest next Friday. Please refer to National Hurricane Center products for more details on Maria. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
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Current forecast is on track. Only minor changes were made to hourly temperatures and dew point temperatures based on the latest observations and near term forecast trends. Upper levels still exhibit the persistent pattern of a strong high amplitude ridge across the Eastern US. Upper jet remains displaced well north into interior SE Canada. For tonight, the weakening post tropical cyclone Jose will keep clouds and some occasional light showers across parts of Long Island and Southeast Connecticut. Otherwise, mainly dry conditions are forecast. North winds will still be gusty at times through the evening and just remain gusty at the coast late tonight. A combination of MAV/MET/NAM12/GMOS was used for min temperatures tonight. Lowered min temps 1-2 degrees across far Eastern Long Island for late tonight. Looking at a range from the upper 50s to upper 60s.
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&& .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... Upper levels still exhibit the persistent pattern of a strong high amplitude ridge across the Eastern US Saturday and Saturday night. Upper jet remains displaced well north into interior SE Canada. For Saturday, high pressure will approach closer to the region and along with it, bring an increase in subsidence. Jose is forecast to further weaken. A dry day is forecast with more sun as clouds will be less than the prior day. The pressure gradient will further decrease across the area. Northerly winds will lower as a result. The warmer MAV was preferred for temperatures due to recent better performance. A combination of MAV and GMOS was used for max temperatures, yielding a range from the upper 70s to upper 80s. For Saturday night, high pressure builds in a little more with continued subsidence. Further weakening of Jose will create an even weaker pressure gradient with winds likewise diminishing. Radiational cooling will result in lower minimum temperatures Saturday night. Used relatively cooler MET guidance for Saturday night lows. && .LONG TERM /SUNDAY THROUGH FRIDAY/... The longwave pattern will continue to be highly amplified with a strong upper ridge over the eastern states, with a trough across the western states, that will remain in place through the beginning of next week with dry conditions and temperatures above seasonal normals. There is a possibility of tying or breaking record highs for Sunday. See the climate section for more information. Meanwhile, Hurricane Maria will track slowly north, east of the eastern seaboard, then northeast through most of the upcoming week as post tropical Jose remains southeast of Cape Cod and dissipates Sunday. Refer to the latest advisories from the National Hurricane Center for the latest forecast information on Jose and Maria. The longwave pattern will transition mid to late next week as a trough digs into the northern plains and Great Lakes region and then moves east as the eastern ridge weakens. This will bring an end to the above normal temperatures. A cold front is expected to cross the area Wednesday night into Thursday. There is some uncertainty with the timing of the digging trough and the cold front crossing the area. However, there will be little moisture accompanying the front and portions of the region may be brushed with the outer bands of showers from Maria late in the week. So, will have mainly slight chance probabilities Wednesday night into Thursday. Weak ridging begins to build to the west Thursday into next Friday. Due to long period swells from both Jose and Maria, there will be a prolonged period of rough surf at the ocean beaches, with the likelihood of a high risk of rip currents. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
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Remnants of Jose will meander and weaken off the southern New England coast through Saturday. VFR expected overnight, except eastern terminals. KGON should observe MVFR cigs most of the night, less than 2 kft. KISP and KBDR need to be watched. Few clouds Saturday all terminals. N winds continue around 10 to perhaps 15 kt, with occasional gusts overnight across NYC metro and eastern terminals. Strongest winds at KGON with gusts well in the 20s. N winds begin to lighten Saturday, especially by afternoon. .OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY... .Saturday night-Monday night...VFR with light winds. .Tuesday-Wednesday...MVFR in showers possible.
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&& .MARINE... The Small Craft Advisory/SCA for the south shore bays expired at 6 pm. An SCA remains in effect for the Eastern Sound and Peconic and Gardiners Bays until 6 am Saturday and for the Atlantic Ocean coastal waters until 6 am Sunday. Long period SE swells will be increasing across the Atlantic ocean coastal waters by Saturday night as winds decrease. Long period swells are expected to remain on the ocean waters Sunday through the upcoming week, and an SCA will likely be needed through the period. Across the remainder of the waters winds and gusts are expected to remain below advisory levels Sunday through Wednesday night. Gusts behind a cold front late Thursday and Thursday night may reach small craft levels across all the forecast waters. && .HYDROLOGY... No hydrologic problems anticipated through the end of next week. && .TIDES/COASTAL FLOODING... Post Tropical Cyclone Jose will remain nearly stationary a couple hundred miles SE of eastern Long Island, with Ekman forcing keeping elevated water levels along the coast despite offshore winds. Water levels should gradually drop tonight into the weekend. Historically, guidance is too fast to bring down water levels in the back shore bays when there is a persistent onshore long period swell, so have continued the coastal flood advisory from Brooklyn through southwest Suffolk County through tonights high tide. There is some potential that there could be some very localized minor flooding at the most vulnerable south shore bay locales Saturday morning. A coastal flood statement was issued for this. Rough surf will also continue into the weekend, but dune erosion from this point on should be localized. && .CLIMATE... The following are record high temperatures for Sunday September 24, 2017 along with the forecast high temperature. Record High Temperature Forecast High Temperature ----------------------------- ------------------------- Central Park........89 (1959) 89 LaGuardia...........89 (1959) 88 Kennedy.............88 (1970) 87 Islip...............83 (2009) 86 Newark..............92 (1959) 90 Bridgeport..........87 (1959) 84 The following are record maximum minimum temperatures for Sunday September 24, 2017 along with the forecast minimum temperature. Record Max Minimum Temperature Forecast Minimum Temperature ------------------------------ ---------------------------- Central Park........74 (1970) 70 LaGuardia...........73 (1970) 71 Kennedy.............71 (1970) 69 Islip...............69 (1970) 65 Newark..............74 (1970) 68 Bridgeport..........71 (2011) 66 && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...Coastal Flood Advisory until 4 AM EDT Saturday for NYZ075-080- 178-179. NJ...None. MARINE...Small Craft Advisory until 6 AM EDT Saturday for ANZ330-340. Small Craft Advisory until 6 AM EDT Sunday for ANZ350-353-355. && $$ SYNOPSIS...JM/MET NEAR TERM...GC SHORT TERM...JM LONG TERM...MET AVIATION...PW MARINE...GC/JM/MET HYDROLOGY...JM/MET TIDES/COASTAL FLOODING... CLIMATE...

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