Area Forecast Discussion
Issued by NWS Upton, NY

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KOKX 192102 AFDOKX Area Forecast Discussion National Weather Service New York NY 402 PM EST Mon Feb 19 2018 .SYNOPSIS... High pressure remains anchored over the western Atlantic through mid week as a slow moving frontal system approaches from the Mississippi Valley. The associated warm front will work north across the area this evening. A cold front moves across Wednesday night. A series of lows will be moving through the Northeast late this week into the weekend. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... A record warm pattern sets up as an anomalously strong upper ridge over the western Atlantic strengthens through mid week. At the same time, a slow moving frontal system associated with an upper trough over the western states work east from the Mississippi Valley. This will place the region in a warm, deep- layered SW flow. A warm front will move across the area tonight preceded by light overrunning rain. Much of the rain will exit the area by midnight with areas of fog and patchy drizzle forming. Temperatures will remain steady if not slowly rise overnight. Lows will be about 15 to 20 degrees above normal, in the 40s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Low clouds, fog, and patchy drizzle will likely start the day on Tuesday with some clearing expected in the afternoon as some warmer, drier air mixes down from aloft. The high res NAM (3km) maintains a strong low-level inversion across the area and maintains saturated low-levels for all but the far interior. This is likely overdone based on past performance and the preference is to go with some improvement. There is though more uncertainty near the immediate coast. Temperatures in this type of airmass will also be tricky with an onshore flow keeping coastal areas much cooler than the interior, where highs will be near record levels. Preference was toward the a MET/MAV MOS along the coast, and the warmer MAV across the interior. Some interior locations will approach 70. Areas of fog and drizzle are likely to develop Tuesday night in the warm, moist airmass, as dew points get into the lower 50s. This will be due to both an advection fog off the cooler marine waters, and radiation fog inland where the SW flow becomes light. Lows Tuesday night will approach 30 degrees above normal, generally in the 50s. These readings will likely break record warmest lows. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... The very active and mild weather pattern will remain in place but will become less mild late this week into the weekend. This is due to a strong Southwest Pacific jet that will remain north of the region through the long term period. It`s quite strong looking at model projections of this jet which convey 190+kt extending from Great Lakes northeast through Canadian Maritimes Wednesday through Thursday. Thereafter, the jet structure remains the same but the magnitude decreases. At the surface, a very busy weather period is in store with several systems moving across. Some notable features include areas of fog going into Wednesday especially along the coast and very warm temperatures continuing Wednesday. Forecast highs Wednesday upper 50s for the Twin Forks of Long Island to lower 70s N/W of NYC. The warmth is not as much for the rest of the forecast period but highs most days looking at Thursday through early next week are forecast to be about 5-10 degrees above normal. The other remarkable feature will be chances of rain which is forecast Wednesday afternoon into Wednesday night as well as Thursday and then again Friday afternoon through the weekend. The periods of rain look to be mostly light to perhaps moderate at times. Early next week, drying conditions are forecast. High pressure moves farther southeast into the Western Atlantic Wednesday. A cold front moves across Wednesday night. The front moves south of Long Island Thursday but stalls with an area of low pressure developing along it. The low and front move farther offshore southeast of Long Island Thursday night with high pressure briefly building in from the north. The high will be moving quickly off the New England coast Friday with another frontal system moving in from the west. Once again, there will be a lingering front behind the system and another low developing along it for the weekend. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... A warm front approaches the area later this evening and tonight, then lifts north of the terminals on Tuesday. VFR conditions with southerly winds 5 to 10 kt. Stratus has overspread much of the region and rain develop through 22z. Some MVFR ceilings have begun to develop across the western terminals and will continue to push east through the late afternoon and early evening. S winds around 10 kt are forecast, and these winds lighten by evening. MVFR to IFR conditions are likely tonight as ceilings lower and fog develops. Cannot rule out LIFR ceilings and visibilities at times as the night progresses. LLWS in the forecast most terminals for SW winds around 2 kft at 35-40 kt. Low conditions continue Tuesday morning, however some improvement is expected by mid to late morning. Uncertain to if we actually reach VFR before 18Z. NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: Amendments are possible this evening for stratus/MVFR ceilings. KLGA TAF Comments: Amendments are possible this evening for stratus/MVFR ceilings. KEWR TAF Comments: Amendments are possible this evening for stratus/MVFR ceilings. KTEB TAF Comments: Amendments are possible this evening for stratus/MVFR ceilings. KHPN TAF Comments: Amendments are possible this evening for stratus/MVFR ceilings. KISP TAF Comments: Amendments are possible this evening for stratus/MVFR ceilings. .OUTLOOK FOR 18Z TUESDAY THROUGH SATURDAY... .Tue...MVFR or IFR possible at night, otherwise VFR with SW wind G15-20KT possible. .Wed...Mostly VFR, patchy fog possible. Chance of showers with MVFR late in the day. SW wind G15-20KT possible. Winds shift to the N at night. .Thu...MVFR in rain. NE wind G15 KT possible. .Fri...CHC MVFR in rain. .Sat...CHC MVFR in rain. && .MARINE... A prolonged period of S-SW winds ahead of a slow moving frontal system approaching from the Mississippi Valley will produce marginal SCA conditions later tonight into Wednesday night on the ocean waters east of Fire Island Inlet. However, current SCA only goes out through the day Wednesday as confidence at this time is too low to extend into Wednesday night. Aside from Wednesday into Wednesday evening with some seas of 5 ft on the ocean, sub-SCA conditions are forecast across the waters for the rest of the week into the weekend. It`s a relatively quiet period with the pressure gradient remaining weak. && .HYDROLOGY... Less than 1/4 inch of rainfall is expected through tonight. Several rounds of rain are possible late this week into the upcoming weekend, but no significant hydrologic impacts are anticipated at this time. && .CLIMATE... Temperatures may approach or break record highs in a few spots Tuesday and Wednesday. Record Highs for Tuesday February 20, 2018 Location........Record/Year Newark..............70/1939 Bridgeport..........54/1991 Central Park........69/1939 LaGuardia...........63/1943 JFK.................61/1949 Islip...............62/2016 Record Highs for Wednesday February 21, 2018 Location........Record/Year Newark..............69/1953 Bridgeport..........59/2002 Central Park........68/1930 LaGuardia...........68/1953 JFK.................63/2002 Islip...............63/2002 && .EQUIPMENT... NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) is off the air for an extended period of time. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory from midnight tonight to 6 PM EST Tuesday for ANZ350-353. && $$ SYNOPSIS...JM/DW NEAR TERM...DW SHORT TERM...DW LONG TERM...JM AVIATION...BC MARINE...JM/DW HYDROLOGY...JM/DW CLIMATE...// EQUIPMENT...//

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.