Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 170007 AFDOKX Area Forecast Discussion National Weather Service New York NY 707 PM EST Mon Jan 16 2017 .SYNOPSIS... A warm front approaches late tonight and early Tuesday. Low pressure passes Tuesday night. An active weather pattern will continue into early next week with multiple frontal systems impacting the area. In between each of these systems, high pressure will be briefly build into the area. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
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Radar returns with reports of sleet now becoming a concern over north central Pennsylvania. If this activity holds together, it reaches Port Jervis at 3Z. Radar appears to be lighting up along the leading edge of the theta-e ridge into New Jersey, but nothing there hitting the ground. There is precipitation, rain per the observations, with the band across central Pennsylvania. No forecast changes at this point; the precipitation needs to overcome some decent dry air, but an early update with significant changes is possible if warranted. Light winds, and clear skies early will allow temperatures to fall through the 30s. Clouds increase, lowering through the night. Temperature falls will cease, with readings likely remaining fairly steady through the remainder of the overnight. The temperatures and onset of any precipitation will be the key to the forecast as moisture ahead of upstream shortwave advects eastward, along with weak lift. Mainly west of NYC (NE NJ and west of the Hudson River), rain will begin very late tonight, if not steady, but spotty. With temperatures close to or just below freezing, light icing is possible during the beginning of the morning commute for these western locales.
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&& .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Mid and upper level ridge gives way to shortwave energy, PVA and mid level lift by late in the day and through the evening. At the surface, weak high pressure moves well to the east as a warm front approaches late in the day. It looks like triple point low pressure develops near the NYC metro in the evening and passes east at night, hugging the coast. Deep moisture by late in the day and through the evening will result in a steady rain. Once again, interior portions of the area in the morning may be cold enough for an increasing area of rain/freezing rain as temperatures hover around the freezing mark before warming. A freezing rain advisory has been posted for these locations for the morning hours. As the low passes Tuesday night and mid and high level moisture moves east, lift weakens and any rain will lighten, taper off and become more intermittent. Patchy fog at night is expected with light flow, cooling temps and abundant low level moisture. Temperatures rise into the upper 30s and lower 40s during the afternoon, then fall back a few degrees at night. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Southern branch of the polar jet will continue to be the main player during this period with multiple Pacific frontal systems impacting the area. Global models are in overall good agreement with some timing differences. During this time, temperatures will remain above seasonable levels with high generally in the 40s and lows in the 30s. Each of the aforementioned frontal systems looks to interact with an airmass that supports primarily rain. The first system will pass to the east Wednesday morning with rain tapering off from west to east. High pressure then follows Thursday into Friday before another southern branch system brings rain to the area. The 12Z operational GFS is stronger with high pressure over eastern Canada with the passage of a northern branch shortwave trof. This scenario would have a somewhat colder airmass in place for Saturday`s event, but model consensus points toward weaker high pressure. Thus, for the time will keep out any mention of freezing rain across the interior. Vertically the airmass would be warm enough for rain. Early next week, another system impacts the area. None of the short term climate predictors show much change in the upper flow through next week. Thus, wet and warm looks to be the them. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/...
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High pressure builds down from southeastern Canada into Tuesday as a warm front slowly approaches from the southwest. VFR through 6z and probably VFR through 12z, though there is a low chance of rain or freezing rain moving into western terminals 9-12z with MVFR ceilings. MVFR conditions develop Tuesday morning at western terminals, with freezing rain at KSWF. Precipitation changes to all rain by early afternoon and moves into eastern terminals, along with MVFR conditions. IFR conditions then develop throughout by mid-late afternoon. Winds become light and variable throughout this evening, and continue into Tuesday morning. E-SE winds at under 10kt develop at mainly coastal terminals Tuesday afternoon, with winds at inland terminals staying mainly light and variable. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component fcsts can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: Timing of onset of light and variable winds could be off +/- 1-2 hours. Timing of onset of rain and MVFR conditions Tuesday morning could be off by around 2 hours. KLGA TAF Comments: Timing of onset of light and variable winds could be off +/- 1-2 hours. Timing of onset of rain and MVFR conditions Tuesday morning could be off by around 2 hours. KEWR TAF Comments: Timing of onset of light and variable winds could be off +/- 1-2 hours. Timing of onset of rain and MVFR conditions Tuesday morning could be off by around 2 hours. KTEB TAF Comments: Timing of onset of light and variable winds could be off +/- 1-2 hours. Timing of onset of rain and MVFR conditions Tuesday morning could be off by around 2 hours. KHPN TAF Comments: Timing of onset of rain and MVFR conditions Tuesday morning could be off by around 2 hours. There is a low chance of freezing rain and MVFR conditions late tonight/early Tuesday morning. KISP TAF Comments: Timing of onset of rain and MVFR conditions around midday Tuesday could be off by around 2 hours. .OUTLOOK FOR 00Z WEDNESDAY THROUGH SATURDAY... .Tuesday night-Wednesday...MVFR/IFR or lower likely in rain. .Wednesday night...Becoming VFR. .Thursday-Friday...VFR. .Friday night-Saturday...Chance of MVFR or lower. E-NE winds G15-20+KT possible.
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&& .MARINE... As high pressure departs, westerly winds will persist, but remain under 15 KTs tonight. A warm front and low pressure will approach the waters Tuesday, and pass over the waters Tuesday night. Winds turn to the east ahead of the front and low during the day Tuesday, then will vary based on location before becoming NW late Tuesday night. With winds remaining rather light through Tuesday night, expect seas to remain 3 ft or less on the ocean, and 1 ft or less across the non ocean waters. Winds on the ocean may approach 20 kt on the ocean late Wednesday into Wednesday night as low pressure gradually intensifies offshore. The low will slowly move to the east Thursday into Friday. Ocean seas should stay below SCA levels, but could approach 4 ft the end of the week. Otherwise, a weak pressure gradient continues to bring Sub-SCA winds on all waters for the end of the week. && .HYDROLOGY... No hydrologic impacts are anticipated with around a half inch of precipitation Tuesday through early Wednesday. The best chance for significant precipitation looks to be early next week as a potential strong southern branch upper trough approaches the region. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Freezing Rain Advisory from 7 AM to noon EST Tuesday for CTZ005. NY...Freezing Rain Advisory from 7 AM to noon EST Tuesday for NYZ068. Freezing Rain Advisory from 4 AM to noon EST Tuesday for NYZ067. NJ...Freezing Rain Advisory from 4 AM to noon EST Tuesday for NJZ002. MARINE...None. && $$ SYNOPSIS...DW/PW NEAR TERM...JMC/PW SHORT TERM...PW LONG TERM...DW AVIATION...Maloit MARINE...DW/PW HYDROLOGY...DW/PW

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