Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 222234 AFDOKX Area Forecast Discussion National Weather Service New York NY 634 PM EDT Wed Mar 22 2017 .SYNOPSIS... Gusty northwest winds will continue through this evening in the wake of a cold front. High pressure builds in tonight from the Great Lakes, moving more into the region on Thursday. The high moves offshore Thursday night. A warm front passes Friday, followed by a cold front Saturday. The front will wobble across the area on Sunday before lifting back north on Monday as a warm front. Additional areas of low pressure may impact the area starting late Monday. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Wind advisories have either expired or been cancelled across the area with gusts generally less than 40 mph, and will continue to gradually subside through the night. Instead of welcoming spring, we are welcoming back winter across the Tri-State Area as chilly air has returned in the wake of a cold front that passed across the area this morning. The main impact in the wake of this front has been gusty northwest winds especially from The City east across Long Island and across CT. Gusts have dropped off even exceeded 50 mph in a few land based locations including a 54 mph gust at the Westhampton Airport. Wind Advisories will be left up as is with coastal areas hanging onto them longer. Surface pressure gradients remain up through most of the night, however, the WRF keeps 925 mb winds over 35 kts across much of the area through 06Z Thursday. There is a bump in the 925 mb winds on this model between 03Z and 06Z across Fairfield County extending into Queens, Nassau and western Suffolk Counties, so there is a possibility if some of this higher momentum aloft mixes down of the need to extend Wind Advisories in some areas for a few hours. Even though winds will gradually drop off overnight in strength, we should still see enough of a breeze overnight to prevent a full decoupling. Thus did not do too much tweaking of lows in the normal radiational spots though we still show between 3 and 5 inches of snow on the ground in the Hudson Valley in Orange and Putnam Counties as of this morning. A clear sky is expected tonight with lows around 20 in The City and most other areas in the teens. The coldest spots will be close to 10 well inland. Some record lows may get reached or tied tonight, see the climate section below. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... Surface high pressure will slide southeast from the Great Lakes Thursday morning toward the Delmarva Peninsula by Thursday afternoon. This will result in a clear sky with northwest winds shutting off by the late morning and winds turning to the west to southwest by the afternoon which will push readings back to near 40 in The City with lower 40s in urban sections of Northeastern NJ and the 30s elsewhere. Ample sunshine will help take the edge off the early spring chill. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... The good news is the really cold weather is on the way out, however, so is seeing the sun during much of the extended as an unsettled weather pattern sets up. A warm front will lift north across the area Thursday night into Friday morning in advance of an area of low pressure ejecting out of the southern Plains. As the Plains low gets closer an increase in moisture will take place and spread light precipitation into the area on Friday morning - possibly as early as 5 to 8 AM. Given temps will be near to below freezing especially inland in the normal Klondike spots of Orange, Putnam, Passaic and CT, there will be the risk for frozen precipitation before temperatures gradually rise above freezing with the passage of the warm front. Forecast model soundings all show a warm nose or warm layer aloft with shallow cold air so the risk for a variety of frozen precipitation exists. Across North Jersey and the Lower Hudson Valley, frozen precipitation may start as snow but quickly go to sleet or more likely freezing rain as the warm layer aloft surges in. Model soundings look a little better for a bit more in the way of snow across interior CT, where at Danbury snow may last a little longer before mixing with sleet and/or freezing rain for a bit before transitioning to all rain. Either way, QPF amounts are mainly a tenth of an inch or less so this will not be a big event but perhaps just enough to create some slick spots on roads if it lasts long enough. If precip is slower to arrive, then p-type will be more likely just rain as temps will warm up by later in the morning. However, this short lived cold snap will chill any road surfaces allowing for even a light amount of precip to get slick except in spots where a hefty salt still sits on the roads. By Friday night, the warm front should push far enough north that most of area dries out except for inland CT where some light rain may linger. The southern Plains low advances east on Saturday toward St. Louis. Our area should be in the warm sector, though still see a decent amount of clouds. Depending on if we get any sun, temps may crack 60 especially from The City on west. Southerly flow off the chilly waters will hold max temps down on The Island, CT and southern parts of Brooklyn and Queens into the 50s. The warm front to our north will start to get shoved back south by later in the day in response to a surface high pressure over eastern Canada. Model consensus is there as to a backdoor cold front moving toward the area Saturday evening and thus we showed an increase up in PoPs in that time frame from east to west across CT and Long Island. Also given the marine push, I added in patchy fog as we may end up seeing more drizzle at times than actual light rain. Temps will slowly fall through the night. Inland we may see a little frozen precipitation if colder air seeps in better than expected. Sunday the main issue is where does the front stall out. The ECMWF on the 00Z operational run was warmer by about 10 degrees in spots than the 12Z operational GFS. For now I played temps in between but suspect from The City on east the cooler scenario will win on out but there is certainly some bust potential with temps. In many spots readings may hold steady or even fall through the day depending on what the front decides to do. We kept in a chance of rain through the day as the approaching low from the west and the front overhead should keep enough lift in place to keep things wet most of the time. Beyond Sunday waves of low pressure are expected to impact the area with a frontal boundary near or north of the area. The first wave should pull east by Monday morning but model agreement was poor after this with timing and the track of the lows. Given the pattern, frozen precipitation may be possible at times well inland especially at night where any cold air is trapped. If the frontal boundary hangs up further south then frozen precipitation is possible further toward the coast. Most likely though the flow aloft is west to southwest, so I have favored a warmer forecast. I bumped up temps a bit over the previous forecast based on a blend of the operational GFS and ECMWF. There could be some breaks in rain at times, but this far out exact timing of features is difficult. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... VFR through the TAF period with mainly clear sky. NW winds near 25KT with gusts up to 40KT peaking this afternoon. Gusts begin to drop off toward sunset and diminish after midnight. Winds pick up again for a few hours midday Thursday but likely drop off in the early afternoon as high pressure settles across the area. NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: http:/ KJFK TAF Comments: No unscheduled amendments expected. KLGA TAF Comments: No unscheduled amendments expected. KEWR TAF Comments: No unscheduled amendments expected. KTEB TAF Comments: No unscheduled amendments expected. KHPN TAF Comments: No unscheduled amendments expected. KISP TAF Comments: No unscheduled amendments expected. .OUTLOOK FOR 18z THURSDAY THROUGH MONDAY... .18z Thursday..VFR. NW winds becoming SW-W 10-15 KT. .Friday...MVFR possible. Chance of SHRA. SW gusts 25 kt. .Saturday...Mainly VFR. Chance of mid-late afternoon MVFR in CIGs and -SHRA. .Saturday night and Sunday...MVFR/IFR and rain. E-SE gusts 20-25 kt. .Monday...MVFR possible in showers. && .MARINE... Gusty winds of 35 kts+ and waves of 4 to 7 ft will continue through early this evening before conditions start to decrease tonight from west to east. Gale warning remains until 06Z Thursday. SCA remains likely thereafter late tonight into early Thursday before all waters go below SCA for the rest of Thursday. Freezing spray was kept in for later tonight into Friday morning especially for the ocean waters and eastern end of The Sound. High pressure moves across the waters Thursday night, and passes well to the east Friday. Winds diminish during this time, but begin to increase from the SW later Friday into Friday night. A cold front approaches from the north Saturday, and settles near or just south of the waters Saturday night into Sunday. Winds diminish, and turn toward the E/NE. Speeds increase yet again Sunday as high pressure builds well to the north. && .FIRE WEATHER... NW winds of 15-30 mph with gusts 35-40 mph and min RH 20 to 30 percent should help dry fine fuels in areas where the snowpack is gone. This will enhance the threat for brush fire spread in those areas through early this evening. Winds are lighter but similar RH values are expected for Thursday. && .HYDROLOGY... Unsettled weather from this weekend through early next week may result in an inch or more of precipitation. However, this would occur over a prolonged period and would be intermittent, so no hydrologic concerns are anticipated. Snowpack melt in interior sections will continue at a slow rate through Thursday with most areas likely loosing any significant snowpack by Saturday as temperatures rise to above normal readings and lows even remain above freezing. && .CLIMATE... The following are record low temperatures for Thursday March 23, 2017 along with the forecast low temperatures. Record Low Temperature Forecast Low Temperature ---------------------- ------------------------ Central Park........12 (1875) 21 LaGuardia...........20 (1959) 22 Kennedy.............20 (1959) 21 Islip...............15 (2004) 18 Newark..............13 (1934) 19 Bridgeport..........19 (2004) 19 && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Gale Warning until 2 AM EDT Thursday for ANZ330-335-338-340- 345-350-353-355. && $$ SYNOPSIS...CS NEAR TERM...DW/CS SHORT TERM...CS LONG TERM...PW/CS AVIATION...IRD MARINE...PW/CS FIRE WEATHER... HYDROLOGY...CS CLIMATE...// is the U.S. government's official web portal to all federal, state and local government web resources and services.