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FXUS61 KOKX 022022
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
422 PM EDT Sun Jul 2 2023

.SYNOPSIS...
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A warm front to the north this evening followed by a weak cool front/trough passage on Monday will result in unsettled weather. A weak cold front will work across the area on Tuesday, followed by high pressure building in for the middle of the week. A frontal system will then slowly approach from the west late in the week into next weekend.
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&& .NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
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The warm front was analyzed across southcentral CT this afternoon with the local area solidly in the warm sector. Back to the west, showers and a few thunderstorms were developing in association with a a mesoscale convective vortex making its way across east central PA. With cloud cover dissipating over much of the area and dewpoints widely in the low 70s, the air mass has destabilized this afternoon (SBCAPE ~ 1000-1500 J/kg) though a bit a of CIN still lingers per the SPC mesoanalysis and NYS Mesonet profilers. Expectation is for shower and thunderstorm activity to increase in coverage this afternoon into this evening as the MCV helps to trigger additional activity. Recent CAMs are depicting convective initiation to be later now, and thus later moving any activity across eastern PA/western NJ into our area after 00Z, as broken line of cells. The later timing of the convection may temper the severe threat a bit, though per model soundings some DCAPE through 03Z would still indicate the potential for gusty winds with any stronger cells. There also remains a threat of heavy rainfall with any thunderstorm through this evening. 12Z HREF maintains low probabilities of greater than 1" in an hour anywhere in the CWA, though there is a 10% prob of greater than 3" in 3hrs across northeastern NJ, which is above flash flood guidance of about 2". The airmass in place depicts PWAT of over 2" per 12Z KOKX RAOB, and though cells should be moving with 15-20kts of midlevel flow, the potential for urban and poor drainage flooding remains across these areas through the evening. The convective activity should weaken as it moves east through the overnight and become elevated. Have maintained the slight chance/isolated thunder chances into the overnight across portions of the CWA to account for this. Fog across the coastal areas may develop early Monday morning with moist environment and light southerly flow. Confidence is low on this occurrence, so have left out of the gridded database for now.
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&& .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
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Any overnight convection should be east of the area by daybreak. Weak H5 ridging aloft gives way to a mid level trough moving through the area by late Monday. The trough axis moves toward the area from the OH Valley but remains west of the CWA by evening. At the surface, a weak prefrontal sfc trough approaches during the afternoon. The airmass in place becomes destabilized by afternoon, with increasing chances of showers and thunderstorms. Model soundings are showing 1000-1500J/kg of SBCAPE along with some bulk shear, 25-30kts. SPC has placed the entire area in a marginal risk for severe thunderstorms, with damaging winds and hail possible with any storm. In addition, given the high PWAT airmass still largely in place, cannot rule out the possibility of an isolated flash flood especially north and west of NYC. 850mb temperatures warm in to the upper teens, 17-19C which will yield a warmer day than Sunday near or just above 90 for NYC and the urban corridor, and mid to upper 80s elsewhere.
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&& .LONG TERM /TUESDAY THROUGH SUNDAY/...
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Models have clearly trended slower with the upper trough lifting out of the Northeast on Tuesday. The latter of which will also send a weak cold front through the area. Environment will be weakly sheared with moderate CAPE values of 1000-1500 J/KG. Thus, chances for scattered convection have come up for Tuesday with the best chances being in the afternoon, possibly lingering into the early evening along the coast. In addition, high PW values will remain close to 2 inches, but storm movement should keep any flood threat to the minor, nuisance variety. We will also be heading into the warmest part of the summer thus far early in the season. There is the potential for a couple of days (Wed and Thu) of 90-degree heat away from the immediate coast. With the aforementioned cold frontal passage potentially being more active Tuesday, highs look to fall short of 90 that day. Heights begin to build with the departure of the upper trough and ridging builds in from the west for the mid week period. 85h temps around 18C will result in surface temps 5-8 degrees above normal. Airmass looks to dry out enough with a W/SW flow to keep heat indices close to the ambient temperature. So at this time, the threat for heat advisory criteria is low. The is a chance for isolated convection Wednesday and Thursday afternoons, mainly inland. However, airmass will be drier with some mid level capping. For the end of the week, heights fall with the approach of another upper trough. The trend has been for a slower progression with the front possibly stalling west of the area for much of the weekend. Temperatures will be cooler in the 80s, largely due to an increase in cloud cover, onshore flow, and possible scattered convection.
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&& .AVIATION /20Z SUNDAY THROUGH FRIDAY/...
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A warm front has lifted north of the forecast area. A cold front slowly approaches from the west on Monday. Outside of some widely scattered showers this afternoon, conditions should be mainly VFR until later this evening, when an area of showers and thunderstorms are expected to move through the terminals. MVFR to IFR conditions are expected with these. They will be associated with heavy rain and gusty winds. For now, limited gusts to 30 kt, though if the storms become strong to severe, winds of 40-50+ kt are possible for a brief time. The timing of these showers and thunderstorms continues to be later with each forecast run, and although current thinking is still 23Z-03Z this evening, these may move through an hour or so later than is currently forecast. Thereafter, MVFR conditions likely persist through the night, with a return to VFR by 12Z Monday. More showers are possible around daybreak, but no restrictions to visibility or ceilings are expected. Outlying terminals may drop to IFR or lower, especially for eastern terminals. Winds are pretty consistent during the TAF period, with a S-SW flow near 5-10 kt for much of the TAF period. There could be a few gusts 15-20 kt this afternoon. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... There is uncertainty concerning the timing of categorical changes as well as thunderstorms during the TAF period. Timing of the categorical changes and thunderstorms could be an hour or two later than is currently forecast. There is additional uncertainty on MVFR conditions overnight tonight in regards to timing and how low conditions become. OUTLOOK FOR 18Z MONDAY THROUGH THURSDAY... Sunday night: MVFR to IFR with periods of showers and thunderstorms. A few S gusts 15-20 kt early. Monday: MVFR or lower at times day into early evening with chances of showers and thunderstorms, showers and thunderstorms likely north and west of NYC terminals afternoon into early evening. Showers and thunderstorms taper off later in evening with VFR returning. Some SW wind gusts 15-20 kt afternoon into early evening. Tuesday: Mainly VFR. Slight chance of showers and thunderstorms with MVFR or lower possible day into early evening north and west of NYC terminals. Wednesday: Mainly VFR. Thursday: Mainly VFR. Slight chance of showers and thunderstorms with MVFR or lower possible afternoon into evening near NYC terminals and to the north and west of NYC terminals. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90
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&& .MARINE...
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Winds and seas are expected to generally be below SCA levels through the upcoming week due to weak gradient winds across the waters. Waves on the eastern ocean zone may approach 5 ft tonight into Monday afternoon with a southerly flow building seas.
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&& .HYDROLOGY...
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There is a chance for areas of minor flooding into this evening with any thunderstorms that do develop across the area. Mainly nuisance and urban poor drainage is expected, but an isolated flash flood cannot be ruled out across northeastern NJ and the Lower Hudson Valley. For Monday, mainly nuisance flooding is possible with any thunderstorms mainly north and west of NYC. No hydrologic issues are expected Tuesday through Sunday.
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&& .TIDES/COASTAL FLOODING...
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In terms of rip currents...A mixture of 3ft@8 sec SE swells and 2-3 ft S wind waves will have a borderline moderate to high risk of rip development Tuesday. Based on climo, higher confidence in high risk for Suffolk County beaches, with threat for high risk possible for western beaches late afternoon w/ sea breeze development. Rip development threat should ease back to solid moderate on Wednesday as S and SE swells subside back to around 2 ft. In terms of coastal flooding...Astronomical tides continue to increase through Tuesday with the approach of a full moon. Generally localized minor coastal flood impacts for tonight and Monday night high tide for southern Queens, southern Westchester and southern Fairfield county, with a bit more widespread minor flooding (up to 1 ft of inundation) for Southern Nassau county. Additional rounds of minor flooding are possible with the evening/night high tide cycle through midweek.
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&& .OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None. NY...Coastal Flood Advisory until 11 PM EDT this evening for NYZ179. Coastal Flood Advisory from 7 PM Monday to midnight EDT Monday night for NYZ179. NJ...None. MARINE...None.
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&& $$ SYNOPSIS...DBR/DW NEAR TERM...DBR SHORT TERM...DBR LONG TERM...DW AVIATION...JP MARINE...DBR/DW HYDROLOGY...DBR/DW TIDES/COASTAL FLOODING...NV