


Area Forecast Discussion
Issued by NWS Upton, NY
Issued by NWS Upton, NY
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210 FXUS61 KOKX 272152 AFDOKX Area Forecast Discussion National Weather Service New York NY 552 PM EDT Fri Jun 27 2025 .SYNOPSIS... High pressure will continue shifting east of the New England coast tonight as a warm front approaches from the south. The front lifts through during Saturday morning, followed by a cold front Saturday night. High pressure returns on Sunday. A frontal boundary advances back north as a warm front Monday afternoon, getting captured by low pressure tracking east in Canada. A cold front follows Tuesday evening with high pressure mid to late next week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Dewpoints have been further lowered through this evening in the forecast due to more mixing than anticipated. Otherwise, the forecast remains on track. High pressure along the New England coast continues to ridge over the area. The surface ridging has allowed for some breaks in the clouds across Long Island and southern Connecticut. Modest mixing has allowed for dew points to drop into the 40s to low 50s for many spots. The rest of the afternoon and evening will remain dry and cool for late June. The high will begin moving offshore tonight as the upper ridge starts weakening. This is in response to an approaching shortwave trough traversing across southeast Canada. The stalled front to our south across the Middle Atlantic begins lifting north as a warm front tonight. Clouds will thicken and lower overnight, especially as the warm front draws closer to the area. Lift with the front is weak with little to no shortwave energy aloft nearby to add a more organized area of forcing. Cannot rule out some showers late tonight and early Saturday morning. Forecast soundings indicate weak lift, likely from overrunning ahead of the warm front, so some drizzle or light rain is also possible earl Saturday morning. Thunder chances overnight/early Saturday appear limited with weak elevated instability nosing in from the southwest late. Have mentioned a slight chance of thunder from around the NYC metro on west, but cannot completely rule it out areawide. The increasing dew points and nearby warm front also support mention of patchy fog. Turbulent mixing above the boundary layer should prevent any of the fog from becoming dense. Have mentioned a slight chance of thunder from around the NYC metro on west. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/... Main concerns for Saturday will increasing heat indices in the afternoon as well as potential for an isolated severe thunderstorm in the late afternoon and early evening. The warm front will continue lifting north of the area in the morning. A shower or two remains possible in the morning and cannot completely rule out a rumble of thunder. Any low clouds, drizzle and fog diminish by mid to late morning as the flow becomes southerly and heating takes place. Temperatures will warm fairly significantly compared to the last few days. Afternoon highs should reach the low 80s across Long Island and southern Connecticut due to onshore flow influence. However, the NYC metro, NE NJ, and Lower Hudson Valley should rise into the middle and upper 80s. Dew points increase into the lower 70s yielding max heat indices in urban NE NJ in the mid to upper 90s with around 90 away from the coast and influence of the marine layer. Potential for convection looks to be late in the afternoon and early evening. Forecast soundings indicate capping around 5 kft into the afternoon and there may be a weak middle level cap/warm air to limit convective development. Heights aloft should fall a bit late in the day with the shortwave moving across New England. The main forcing will come from surface convergence and some lift from weak energy aloft. These features should be enough to allow convection to develop in an environment with about 1000 J/kg of MLCAPE and about 25 kt of 0-6 km unidirectional shear. The stronger flow/shear looks to reside northeast of the area and greater instability likely remains across the Middle Atlantic. CAMs have signaled potential of a fairly progressive broken line of convection developing late in the day and moving into the area in the evening. As the line encounters the marine environment, the line should weaken as it encounters more stable air across Long Island and Connecticut towards or just after sunset. SPC has maintained a marginal risk for a severe thunderstorm west of Long Island and Connecticut. The main concern is from damaging wind gusts. Locally heavy downpours are possible as PWATs are increase to around 1.80 in. However, the progressive nature of the system will limit duration of heavy rain and limit the overall flood threat. Minor urban and poor drainage flooding is possible. The front and shortwave push east of the area Saturday night. High pressure builds in from the west allowing some drier air to move into the area. The building high pressure and lingering troughing just to our east sets the stage for a predominately westerly flow on Sunday. This should hold off sea breezes until potentially late in the day. Guidance has trended warmer on Sunday with highs now in the middle to upper 80s. Heat indices look to remain near the actual air temperature as dew points should mix out into the lower 60s due to the westerly flow. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... A weakly amplified ridge with high pressure at the surface keeps conditions mainly dry Sunday night into large portion of Monday. Mainly clear conditions are expected Sunday night. Cloud cover may increase late Monday afternoon as the ridge begins to shift offshore in response to a trough that digs into the Great Lakes and Canada. This trough also brings surface low pressure to our north in Canada, which captures a stalled frontal boundary to our south, bringing it through our area Monday afternoon as a warm front. We remain warm-sectored Monday evening into Tuesday evening before a cold front moves through early Tuesday night. Warm temperatures, ample moisture, higher dewpoints, and decent instability should lead to not only showers during this period, but general thunderstorms. Global models are bringing pockets of 1500-3000 J/kg through the area during this timeframe. Severe weather looks unlikely until the cold front. Ahead of the FROPA, bulk shear looks to climb to 35-45 kts which could lead to some stronger updrafts in longer-lived thunderstorms. This may support some heavier downpours and instances of damaging winds in stronger thunderstorms that develop along and ahead of the cold front. Late Tuesday night, conditions dry as zonal flow sets in a loft with high pressure at the surface holding Wednesday into Friday. Temperatures Monday and Tuesday range from the mid 80s for most to lower 90s in parts of the urban NYC metro. With dew pts progged into the 60s and 70s. Little in the way of temperature relief behind the front Tuesday night, though drier air in subsequent W/NW flow helps to lower humidity values mid to late week. && .AVIATION /22Z FRIDAY THROUGH WEDNESDAY/... High pressure builds in from the northeast, as a frontal boundary remains draped to the south over the Mid Atlantic. Mainly VFR for the rest of the afternoon. MVFR and eventually IFR ceilings build in after 3Z Sat with light rain developing from west to east. Categories lower to IFR for most terminals through the Saturday morning push. Some improvement in categories possible after 13-15Z for the NYC terminals with rain ending. Outlying terminals will take longer to improve to MVFR. MVFR to VFR possible for terminals into the afternoon. SHRA and TSRA possible after 20Z for western terminals. Included as a Prob30 for now for the NYC terminals. Timing of best chance for TSRA for the NYC terminals looks closer to 00Z with coverage isolated to scattered. Winds are E to SE with occasional gusts to around 20 kt. Gusts diminishing by 00Z Sat. Winds then become primarily S by Saturday morning. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Amendments possible for timing of category changes and onset of rain this evening/tonight. Gusts today may be more occasional at times. .OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY... Saturday: Any remaining MVFR cigs should become VFR except outlying terminals. Showers likely with a chance of thunderstorms and MVFR in the evening. Sunday and Monday: Mainly VFR. A chance of showers and thunderstorms late Monday and Monday night. Tuesday: Showers and thunderstorms with MVFR or lower possible, especially late afternoon and evening. Wednesday: Mainly VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... The SCA remains on the ocean this evening. Wind gusts close to 25 kt are possible this evening with seas around 5 ft. Seas should subside below 5 ft followed by conditions on the ocean below SCA levels through the rest of the night. Winds may increase again on Saturday, but should remain below 25 kt. Otherwise, conditions will remain below SCA levels through Sunday. Sub-SCA conditions are expected Sunday night through early Tuesday. Winds and waves may approach SCA conditions Tue afternoon into early Tue night in response to an approaching and passing cold front. Thereafter, sub-SCA conditions return into mid & late week. && .HYDROLOGY... No significant hydrologic concerns are anticipated through next week. Locally heavy downpours will be quick moving late Saturday into Saturday evening with only minor nuisance flooding expected. && .TIDES/COASTAL FLOODING... Localized minor coastal flooding remains possible for the most vulnerable spots along the back bays of S Nassau and Queens during this evening`s high tide cycle, as water levels come down slightly from a new moon early in the week. No statements were issued as no impacts are expected. A high rip current risk remains for ocean beaches into this evening. Surf height lowers to 2 feet Saturday with onshore flow, so rip current risk will lower to moderate on Saturday. Sunday, winds shift to westerly for a portion of the day, but rip risk remain moderate under 2 ft surf height. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...High Risk for Rip Currents until 9 PM EDT this evening for NYZ075- 080-081-178-179. NJ...None. MARINE...Small Craft Advisory until 11 PM EDT this evening for ANZ350- 353-355. && $$ SYNOPSIS...BR/DS NEAR TERM...BR/DS SHORT TERM...DS LONG TERM...BR AVIATION...MW MARINE...BR/DS HYDROLOGY...BR/DS TIDES/COASTAL FLOODING...