000
FXUS61 KOKX 260014
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
814 PM EDT Sun Jun 25 2023

.SYNOPSIS...
A weak trough remains near the region tonight before another
trough of low pressure approaches from the west on Monday. A
slow moving frontal system will impact the area through mid-
to-late week. Weak high pressure tries to move in Friday before
another frontal system approaches from the west impacting the
region through the weekend.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
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Showers and storms have continued through early this evening for far western portions of the NE NJ. These are now winding down for the second half of this evening with the loss of daytime heating. Although the atmosphere remains primed just west of NYC and west of the NJ shore with a spoke of upper level energy and WPC mesoanalysis not showing much of a wane in instability, the activity should be less going forward. Much of the activity has been driven by cell mergers on residual boundaries which is all it takes with the humidity and enough instability in place. Any storms have had a history of producing torrential rain with 1 to 2 inch amounts in a short period of time. However, radar trends and CAMs support this being increasingly unlikely going through the subsequent hours leading towards midnight. Thus have lowered PoPs later, especially further east over the next several hours until just before dawn. Overall conditions should be more dry than wet, but can`t rule out additional pop up showers/storms during this period, especially towards daybreak Monday. With little change in the airmass from the previous few nights, patchy fog is once again expected to develop from east to west tonight. The question remains how far west and northwest this can expand, and how much coverage (patchy vs areas). Far SE sections of LI already seeing fog with visibilities getting below a mile in spots. Winds just above the surface are a little stronger than the past couple nights which could disrupt fog development, although more widespread and/or dense development can`t be ruled out. As with previous nights, the best chances remain along the coast. Overnight lows will again remain in the mid to upper 60s.
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&& .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... Monday is expected to be an active weather day as a vertically stacked low over Michigan slowly moves east during the day. Energy out ahead of this feature will combine with jet energy rounding the base of the upper trough and a developing surface trough to spark convection during the afternoon and evening hours. A few unorganized showers and thunderstorms could be ongoing to start the day, but those should give way to the potential for more organized convection as the day wears on. By late afternoon, CAPE is expected to climb to 1000-1500 J/kg west of NYC along with bulk shear of 30-35 kts. SPC continues to place the NYC Metro, northeast New Jersey, western Long Island, and portions of the Lower Hudson Valley in a slight risk for severe weather, with the remainder of the region in a marginal risk. The greatest threat with any strong to severe storms would be the potential for damaging winds, although an isolated tornado can`t be ruled out north and west of NYC. In addition to the potential for severe thunderstorms, a flash flood threat also remains, with WPC including northeast New Jersey in a slight risk of excessive rainfall. While the ingredients are in place to support the development of strong to severe storms, the exact evolution of the convection remains uncertain. Some of today`s 12Z high resolution model runs indicate the potential for multiple rounds of convection, possibly beginning as early as 15-16Z over western portions of the area. Any early convection may limit the available instability later in the afternoon/evening. In addition, the timing of the primary convection looks to be on the late side - after 21Z and possibly after 00Z, at which point diurnal support would be waning. For areas east of NYC, another mitigating factor is the general south to southeast flow, which introduces more of a marine influence and could help suppress any eastward moving convection. While the potential for severe weather diminishes overnight, shower and thunderstorm chances will linger across the region as the upper low draws closer. The combination of lingering shower activity and overall higher winds should preclude any fog development Monday night. Temperatures on Monday are expected to rise into the upper 70s to lower 80s, near to slightly below normal for late June. Overnight lows will fall into the mid to upper 60s. && .LONG TERM /TUESDAY THROUGH SUNDAY/... The unsettled pattern will continue through the long term, with the only chance of a brief reprieve and perhaps more intervals of sunshine overall towards Fri / Sat. Shower and thunderstorm coverage will be numerous to widespread on Tuesday with a possible moderate to heavy downpour with WPC giving the city and interior areas a Marginal risk for excessive rainfall. The risk for flooding from any moderate or heavy downpours will depend on how waterlogged the soils get over the next few days. PWATs sit around 1.6-1.7" based on the 12Z GFS, the 6Z ECMWF getting close to 1.8" and the 12Z NAM giving upwards of 2.1" on Tuesday. Aside from the risk for heavier rain, thunderstorms may pose their own risks. The latest 12Z NAM is putting out 2500-2800 J/kg of MUCAPE with Bulk Sfc-500mb shear of 40- 50 kts and mid- level lapse rates between 6 and 7C/km. The SPC currently has us under a Marginal Risk for severe weather on Tuesday. Coverage of showers and storms may start lessen on Wednesday as the deeper moisture axis starts shifting to the east and north as a front and triple point pass overhead or nearby. However, the upper trough and closed low will only slowly move overhead into Thursday. Shower and scattered t-storm activity remains possible, especially in the afternoon and evening. The trough and associated frontal system may start to shift to the east on Friday with weak high pressure trying to settle, but confidence how this evolves is still quite low. 700mb RH values from deterministic models would suggest some moments of sun in between periods of clouds on Friday. Look for daily max temps to average below normal with a good deal of daytime cloud cover anticipated on average throughout the period. There may be a day towards Fri or Sat where daytime temps may get closer to normal. Night minimums should average close to normal with higher humidity due to a persistent southerly flow and a good chance of night time cloud cover. Mainly used NBM for temperatures. Late Saturday into Sunday another frontal system will approach us from the west increasing southerly flow and thereby increasing available moisture and keeping temperatures warm. && .AVIATION /00Z MONDAY THROUGH FRIDAY/...
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A low pressure trough remains nearby through tonight. Another trough moves into the region Monday along with a warm front to the west. Generally VFR early this evening, then becoming IFR, possibly LIFR, as stratus and fog develop 02Z to 04Z, and spread west. Timing and how low conditions will be are highly uncertain. There is a chance of showers during the overnight which may briefly improve conditions a little, still remaining IFR or MVFR. Thunderstorms are possible late Monday morning into the afternoon, with the potential for stronger thunderstorms late in the afternoon and into the evening, especially from the NYC metro terminals and north and west. Heavy rain, gusty winds and even small hail are possible. MVFR/IFR likely with any thunderstorm. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Amendments likely this evening for lowering conditions as fog and stratus develop. Uncertainty with the timing, and how low conditions will be. IFR to LIFR expected. Amendments Monday for timing of improvements. There is a chance of thunderstorms late morning into the afternoon. Stronger thunderstorms are possible late Monday afternoon into the early evening with gusty winds, and small hail is possible. OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY... Monday night: Showers. A chance of tstms with gusty winds from around the NYC metros and north and west early in the evening. MVFR cond expected, IFR possible. Tuesday and Wednesday: Showers. Tstms with gusty winds and hail possible, especially afternoon/evening. MVFR cond expected, IFR possible. Tuesday S winds G20-25kt. Thursday: Chance of showers and a slight chance of tstms. MVFR or lower possible at times. Friday: Becoming VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90
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&& .MARINE... Fog has lingered over the eastern ocean waters for much of the day and is expected to expand westward across most of the waters again tonight. The primary exception to this will be NY Harbor. The fog could once again become dense. Otherwise, both winds and seas are expected to remain below SCA criteria through the day on Monday before increasing Monday night on increasingly southerly flow. By Tuesday, seas on the ocean will increase to 5-6 feet, and are expected to remain elevated into Wednesday night before decreasing during the day on Thursday. Winds will also increase to around 25 kt on the ocean on Tuesday. && .HYDROLOGY... Minor flooding of low lying and poor drainage areas will remain possible in any heavier showers this evening across the Lower Hudson Valley and northeast New Jersey. There is a continued risk of minor flooding and localized flash flooding mainly late Monday into Tuesday in showers and thunderstorms. WPC continues to carry a slight risk of excessive rainfall across northeast New Jersey on Monday and a marginal risk across the remainder of the area, with a marginal risk for the entire region on Tuesday. Hydrologic impacts are also possible Wednesday into Thursday, but may be dependent on where the heaviest rainfall occurs through Tuesday. WPC currently has a marginal risk of excessive rainfall NW of the NYC metro. && .TIDES/COASTAL FLOODING... The moderate risk of rip current development continues for all ocean beaches through Monday, with an upgrade to a high risk on Tuesday. The rip current risk is being driven mainly due to south to southeasterly swells. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...FEB/BR NEAR TERM...FEB/JE SHORT TERM...FEB LONG TERM...BR AVIATION...MET MARINE...FEB HYDROLOGY...FEB/DS TIDES/COASTAL FLOODING...