000
FXUS61 KOKX 212021
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
421 PM EDT Fri Apr 21 2023

.SYNOPSIS...
-- Changed Discussion --
A warm front will work slowly north from the Mid Atlantic states tonight, stalling near or just south of the area on Saturday. A cold front along with a frontal wave will then move across the area Saturday night into Sunday morning. A weak secondary cold front will pass through Sunday night, with high pressure to the west slow to build in thereafter through mid week as weak low pressure lingers along the New England coast. Another low pressure system may impact the area toward the end of the week.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
-- Changed Discussion --
An easterly flow ahead of a warm front over southern NJ will work slowly north tonight. Low clouds/areas of fog will expand along the NJ coast early this evening and work across the area tonight. Far eastern LI/SE CT, there may be enough low-level ridging and drier air to keep the fog in check with just some stratus. In addition, the fog could be more patchy in nature and not dense as dew points will generally be at or below the sea surface temps. There is also a low chance for drizzle overnight with a strengthening LLJ, but lift is weak and moisture is real shallow. For the time, will keep it out of the forecast. Lows will drop into the upper 40s and lower 50s in outlying areas, to the the lower to mid 50s across the NYC metro. This is 5 to 8 degrees above normal. See climate section below as a few locations could be near record max minimums.
-- End Changed Discussion --
&& .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
-- Changed Discussion --
Areas of fog and low clouds in the morning will likely dissipate as far east as western LI and SW CT by afternoon. There is less certainty with this improvement making it into eastern LI and SE CT with a warm front stalled just to the south and east to southeast winds bringing in warmer, moist air across the cooler near short waters. Aloft, an upper low will continue to fill across the Great Lakes, while the longwave trough becomes more negatively tilted as it works across the Tennessee and Ohio Valleys on Saturday. This will send a cold front toward the area that will move across the area late Saturday night into Sunday morning. There will be some instability to support embedded thunderstorms with the main band of showers that move in Saturday night, exiting far eastern areas Sunday morning. The system looks to be slow enough with enough lift for a moderate rainfall event with 0.75 to 1.25 inches expected across the area. The highest amounts will be inland where there will be some orographic enhancement in a SE flow ahead of the cold front. It will remain unseasonably warm, especially away from the coast, with highs once again around 70 west of NYC and up into the Lower Hudson Valley. It will mainly be in the 60s elsewhere with 50s along the immediate south shore of LI. For Sunday, conditions dry out by afternoon but there will remain a slight chance of showers with the upper trough axis lifting across the area. It will be a bit cooler away from the coast Sunday with highs in the 60s most locations.
-- End Changed Discussion --
&& .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
-- Changed Discussion --
A large upper level trough with a weakening surface low lingers over the area through much of the beginning of the week. This will likely result in continued chances of precipitation, generally in the form of rain showers, Sunday night through Tuesday afternoon. Daytime heating may allow for some elevated instability which could cause some instability showers to develop, but should be limited enough to prevent the occurrence of any thunder each afternoon. The upper level trough flattens out as high pressure moves into the area from the southwest late Tuesday and into Wednesday. This should result in fairly dry conditions for the middle of the week. Beyond this, models diverge in how they handle the following system, but a potential coastal low develops south of the area and approaches sometime in the Thursday to Friday timeframe which may result in some rain. Kept PoPs at slight chance/chance for now to indicate uncertainty in timing and strength of the system. Temperatures will be generally seasonable for late April through the long term forecast. Highs each day will be in the upper 560s to middle 60s with lows generally in the 40s each night.
-- End Changed Discussion --
&& .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
A warm front approaches tonight and remains over or just south of the area through Saturday. E-SE winds just over 10 kt, stronger closer to the coast, with some gusts 15-18 kt. Winds should back a little more easterly and slowly diminish this evening. VFR through the rest of the afternoon. As the warm front approaches, cigs/vsby should lower this evening. At the NYC metros, MVFR cigs may be possible as early as 21Z, more importantly IFR cigs should arrive there after about 23Z-01Z, with LIFR by 03Z-05Z. Farther north and east, IFR possible at KISP/KHPN/KBDR by 03Z-04Z. MVFR cigs should arrive at KSWF/KGON about that same time, and may not go IFR at all. Guidance indicates possible improvement around 13-15Z Saturday morning but timing and the level of improvement is uncertain. MVFR could linger a bit longer in the morning SW winds increase through the Saturday, with 10-14G20KT by 18z. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... AMD likely this evening to fine-tune arrival of lower cigs. OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY... Saturday Afternoon: VFR, then MVFR, possibly IFR redevelop during the late day and at night, with showers arriving. Slight chance of thunder at night. SE winds G20-25 kt in the afternoon and at night. Sunday: MVFR or lower in showers, especially E of the NYC metros. Monday and Tuesday: VFR. W-NW winds G15-20 kt. Wednesday: VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
As a warm front approaches from the south tonight into Saturday, a weak pressure gradient will keep winds and seas below SCA criteria through early Saturday. Areas of fog may develop tonight, with the possibility of dense fog affecting the waters. However, there is some uncertainty with how dense the fog will become. SCA conditions are possible Saturday night ahead of an approaching cold front and wave of low pressure. Seas looks to come up to around 5 ft on the ocean waters with marginal gusts approaching 25 kt. Confidence not high enough to issue at this time. Ocean seas may be elevated to near 5 feet Sunday night but fall below SCA by Monday morning. Sub-SCA conditions are then expected on all waters through the middle of the week.
-- End Changed Discussion --
&& .HYDROLOGY... No hydrologic impacts are expected through the weekend. A frontal system could bring 0.75" to 1.25" rainfall from Sat night into Sunday morning, with locally higher amounts of around 1.50" possible, leading to nuisance impacts being the most likely outcome due to antecedent dry conditions. No hydrologic impacts expected from Monday onward. && .CLIMATE...
-- Changed Discussion --
The following are record temperatures for Saturday April 22nd. Currently the forecast reflects that the records may be reached at some of our climate sites. Record Max Minimum Temperatures for Saturday April 22nd ------------------------------------ Central Park........62 (2016) LaGuardia...........61 (2016) * Kennedy.............54 (1985) * Islip...............54 (1976,1974) Newark..............61 (2016) * Bridgeport..........53 (2016) * - Temperatures currently forecast to be within 2 degrees of the minimum temperature record $$ .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None.
-- End Changed Discussion --
&& $$ SYNOPSIS...DW/MW NEAR TERM...DW SHORT TERM...DW LONG TERM...MW AVIATION...JT MARINE...DW/MW HYDROLOGY...DW/MW