Area Forecast Discussion
Issued by NWS Upton, NY

Current Version | Previous Version | Text Only | 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
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
899 FXUS61 KOKX 210601 AFDOKX Area Forecast Discussion National Weather Service New York NY 201 AM EDT Tue Mar 21 2017 .SYNOPSIS...
-- Changed Discussion --
A weak cold front will move across Tuesday morning, followed by a stronger cold front Tuesday night. This second front will usher in much colder air Wednesday and Thursday via building Canadian high pressure. Milder air will return later this week, before a cold front probably sags to the south this weekend.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 6 AM THIS MORNING/...
-- Changed Discussion --
Ahead of the weak cold front, there is some weak warm air advection. RUC analysis of 975 and 950mb show temperatures a few degrees above freezing and surface temperatures have held within the upper 30s to mid 40s for most locations. Winds are light and variable with a broken to overcast mid deck of clouds in place. The temperatures are forecast to just lower a few degrees for most locations on average with radiational cooling thus mitigated from clouds overhead. The bulk of the precip towards daybreak Tuesday will be southwest of the region, associated with a weak frontal system traversing the mid-Atlantic, but it may brush the extreme SW portions of the local forecast region. Ambient temperatures in place for those sections will allow for a slight chance of light rain with otherwise mainly dry conditions elsewhere. The interior temperatures are forecast to drop to right near freezing so any precipitation there could be light freezing rain, but again those farther northward sections are expected to remain dry.
-- End Changed Discussion --
&& .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
-- Changed Discussion --
Weak cold front moves across during the morning. After morning cloudiness (and perhaps a brief rain/snow shower), clearing should set in during afternoon as drier air works into region. Sunshine and westerly flow will help temperatures reach lower and mid 50s Tuesday afternoon, if not a little warmer in and around NYC due to downslope flow. Stronger cold front approaches Tuesday night as upper trough rotates through eastern Great Lakes. Front should pass through close to daybreak Wednesday, but once again moisture looks to be fairly limited, so we will continue with dry forecast. Lows should drop into 20s inland and low 30s near coast.
-- End Changed Discussion --
&& .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... Models and ensembles continue to advertise highly amplified pattern as upper trough heads to Maritimes Wed/Thu. Ridging tries to build in behind system Fri but there are differences in position and strength of developing trough next weekend. Canadian high pressure builds over region Wed/Thu which will result in below average temperatures. Despite March sunshine, highs should only reach 30s both days. Lows Wed night should range from teens inland to low 20s near coast. Should also be rather brisk which will send wind chills into single numbers at times, or even below zero inland. Temperatures begin to modify Fri as high moves offshore and SW flow gets underway. Then our attention turns to a backdoor front, which should drop south through area Saturday night or Sunday morning, as strong high pressure builds across Hudson Bay. We then need to keep an eye on low pressure emerging from Ohio Valley, which may end up bringing some precipitation to area Sun-Mon or keeps everything suppressed to our south. Too much uncertainty this far out to say which solution is more favored at this time. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
High pressure remains over the region tonight. A weak cold front will move through Tuesday morning, bringing only additional clouds. Light northwest winds tonight, generally 10 KTS or less. Winds will increase during the mid to late morning on Tuesday, becoming more westerly by afternoon. Clouds become more scattered behind the passing front. VFR through the TAF period. .OUTLOOK FOR 00z TUESDAY THROUGH Saturday... Tuesday night-Thursday..VFR. NW gusts 20-25 kt possible on Wednesday. .Friday...Chance of sub-VFR cigs. .Saturday...Mainly VFR.
-- End Changed Discussion --
&& .MARINE... Quiet through Tue night, with a weak cold frontal passage Tue morning. A stronger cold front passing early Wed morning will be followed by increasing NW winds. Gusts to 30 kt are most likely but it`s certainly possible gusts could reach 35-40 kt, especially on the ocean. A gale watch has been issued for all waters, since this surge of cold is very impressive for late March and can easily lead to these higher gusts to gale force. Winds and seas diminish once again Thu as high pressure builds over the waters. SW flow gets underway Fri as the high moves east. but winds and seas probably stay below SCA. && .HYDROLOGY... No hydrologic problems expected through this week. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Gale Watch from Wednesday morning through late Wednesday night for ANZ330-335-338-340-345-350-353-355. && $$ NEAR TERM...JM AVIATION...CB

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