Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 261129 AFDOKX Area Forecast Discussion National Weather Service New York NY 729 AM EDT Tue Mar 26 2024 .SYNOPSIS... A high pressure ridge over the area will gradually weaken through tonight. A cold front approaches on Wednesday and slowly passes through during Wednesday night into Thursday. Meanwhile, low pressure develops along the Atlantic seaboard, tracks NE, passing us to the southeast late Thursday night into Friday morning. The low eventually tracks into the Canadian Maritimes over the weekend. Another low pressure system may impact the area early next week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... The forecast is mainly on track. Minor adjustments were made to hourly temperatures and dewpoints based on the latest trends. Shallow moisture trapped under an inversion keeps us cloudy today. Weak isentropic lift arriving from the east introduces a slight chance of light rain or drizzle over LI and southern CT this morning. Chances of light rain and drizzle then expand west this afternoon with the help of some isentropic lift. High temperatures about 5 degrees below normal. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... Light rain and drizzle potential expands farther to the rest of the area tonight. Moisture then deepens west to east on Wednesday ahead of a cold front. Threat of rain therefore trends higher towards the western zones. Also expecting areas of fog starting tonight when the turbulent mixing potential near the bottom of the low level inversion lessens. We could be stuck with the fog well into the day Wednesday with light winds and plenty of low level moisture. Milder for Wednesday, with highs in the 50s. A cold front enters the forecast area Wednesday night, bringing an area of focused moisture convergence with it. Rain is therefore likely Wednesday night with the deeper moisture and lift along the front. Models show elevated CAPE Wednesday afternoon and night, but lift appears to be to weak for a mention of thunder. The front slows its eastward motion on Thursday as the flow aloft amplifies and a 500mb trough axis approaches. This will help focus energy along an elongated area of low pressure toward the Carolina coast. This deepening low center then tracks NE and approaches not too far SE of the 40N/70W benchmark late Thursday night. The combination of the front, frontogenetic forcing on the NW side of the elongated low, and synoptic upper divergence from a jet streak continue the likelihood of rain across the area on Thursday, with rain chances diminishing west to east Thursday night. Cold air wraps in from the NW as the rain is ending late, but likely too late for any potential snow (northernmost zones only) to be of any significance. Will keep out the mention of snow for the time being. && .LONG TERM /FRIDAY THROUGH MONDAY/... Low pressure passes east of the region on Friday, as a cold front slides east of the region. Any left over precipitation Friday morning is expected to come to an end shortly after daybreak, mainly across the eastern sections of Long Island and Connecticut. There is a low end chance that POPs linger into Friday afternoon. There is some uncertainty with just how strong the low is that passes east of the area and its exact placement on Friday. The deeper the low is, the better chance that we could see some snow showers on the back end of the precipitation Friday morning. Will go with a rain/snow mix for now. Otherwise, expect a gusty northwest flow, with a colder/drier airmass working into the region. Conditions are expected to remain dry at least Friday night and the first half of Saturday. Some of the forecast guidance is hinting at a quick moving low pressure system/upper level shortwave to pass over the area late Saturday into Sunday. This may set off a few showers/light rain, however the timing and placement of this feature remains a bit uncertain with low confidence. Will only carry slight chance POPs for now. The next chance of rain comes Monday night into Tuesday as yet another low pressure treks towards the region. With this being a day 7-8 event, will cap POPs at 50 for now. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/...
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High pressure over the terminals slowly weakens today. MVFR ceilings are expected at all the area terminals through the day and into the evening. IFR is possible at KGON late this afternoon and evening. Tonight, conditions are expected to fall to IFR with low end chance of some terminals falling below IFR. Confidence remains low, however where confidence is highest, have included a TEMPO to cover this threat. Conditions improve Wednesday morning to MVFR. NE winds around 10 kt early this morning for NYC and Lower Hudson Valley terminals. Further east, NE winds 10-15 kt with gusts around 20 kt. NNE-NE winds are expected to continue through much of the day today, generally 10-15 kt. Wind speeds may begin to fall below 10 kt this evening. NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Timing of MVFR to IFR or lower may be off by an hour or two. OUTLOOK FOR 12Z WEDNESDAY THROUGH SATURDAY... Wednesday: MVFR to IFR. Areas of of light rain or drizzle possible. Thursday: IFR with rain likely. Friday: MVFR early, becoming VFR in the afternoon. Chance of rain early. NW wind gusts 20-25 kt possible. Saturday: VFR. NW wind gusts 20-25 kt possible. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90
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&& .MARINE... SCA remain in place on the ocean through Weds afternoon due mainly to elevated seas from a lingering swell. Gusts to at least 25kt also expected during the day today, but becoming less likely heading into the evening. SCA also for eastern LI sound through this afternoon - again primarily for elevated wave heights. A prolonged period of winds at or below 10kt is expected from late tonight through Thursday morning. Winds then increase Thurs afternoon and night from the N-NW as the pressure gradient tightens over the waters. Advisory level gusts expected at for all waters by the end of this period. Could get close to gales on the ocean late Thursday night. Low pressure passing east of the waters on Friday will result in at least small craft conditions with both gusty winds and elevated seas. There is a chance gales will be needed during the daytime Friday. The small craft conditions are likely to continue through the first half of the weekend before conditions subside below SCA levels. && .HYDROLOGY... Mostly 1-2 inches of rainfall is forecast from Wednesday through Thursday night. The higher amounts will be focused more toward Long Island and southern Connecticut. Given the current flash flood guidance, not anticipating hydrologic impacts, but if the expected totals ramp up in subsequent forecasts, maybe some minor flooding could occur over southern Connecticut. No hydrologic impacts are anticipated for the weekend and into early next week. && .TIDES/COASTAL FLOODING... The current forecast is a blend of the previous forecast and NYHOPS with consideration of the the departure trends seen since the past high tide cycle. Advisories remain in effect for today`s high tide cycle for Southern Nassau County, as well as along western LI Sound from Southern Fairfield/Northern Nassau on westward. Coastal flood statements, where flooding is expected to be only isolated and barely reached, remain across NY Harbor through the rest of Southern Brooklyn/Queens as well as the south shore back bays of SW Suffolk County. Winds will be much lighter in the hours leading up to tonight`s high tide cycle, so not enough confidence to issue advisories/statements for tonight in spite of the nighttime cycle being higher astronomically. Perhaps Southern Nassau and Southern Fairfield counties could need an advisory, but might only need a statement. Will allow the next shift to assess trends and updated guidance for further headline considerations. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Coastal Flood Advisory from noon today to 3 PM EDT this afternoon for CTZ009. NY...Coastal Flood Advisory from noon today to 3 PM EDT this afternoon for NYZ071-073-176-177. Coastal Flood Advisory until 1 PM EDT this afternoon for NYZ179. NJ...None. MARINE...Small Craft Advisory until 6 PM EDT this evening for ANZ332. Small Craft Advisory until 6 PM EDT Wednesday for ANZ350-353- 355. && $$ SYNOPSIS...BC/JC NEAR TERM...JC SHORT TERM...JC LONG TERM...BC AVIATION...BC MARINE...BC/JC HYDROLOGY...BC/JC TIDES/COASTAL FLOODING...

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