Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 291730 AFDOKX Area Forecast Discussion National Weather Service New York NY 1230 PM EST Tue Nov 29 2016 .SYNOPSIS... A pair of storm systems that will affect the area Today into Wednesday night. The first storm will move in today and depart this evening. The second storm will impact the area Wednesday through Wednesday night. High pressure will then slowly return for late week into the weekend, with only a weak cold frontal passage on Friday. Another low could impact the area Sunday night into Monday. && .NEAR TERM /THROUGH TONIGHT/...
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Several chances at this time...as a large Mid-Latitude Cyclone over eastern North America with upper tropospheric center over central Minnesota. Significant difluence aloft proving forcing for good stratiform rain event over the region at this time. Rainfall rates in the 0.15-0.25" per hour range. Heavier rainfall starts to taper down by sunset from west to east. Plenty of nuisance flooding on roadways and will issue a statement. With the low levels being very stable, have backed down on the potential for strong winds. Thinking that peak gusts will remain 30 mph or less. Have also removed thunder as colder cloud tops are now moving into New England and there has not been any intra-cloud lightning detected. lastly...have the rain ending sooner than previous with all rain over before midnight. Winds go calm overnight and thus fog...locally dense...is expected,,,mainly . Temps above normal with highs in the 55-60 degree range. Lows tonight may not drop below normal highs for this time of year...50s coast and well into the 40s interior.
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&& .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... After a brief respite early Wed morning...the second and potentially stronger frontal system approaches Wed and crosses through the region Wed Night. Forcing will be from 150kt jet streak and strong PAC energy rotating around the large closed low moving ne from the northern plains into Southern Ontario/Quebec Wed into Wed night. At the surface...primary low pressure tracks through the Great Lakes Wed/Wed Night with a warm front approaching the region during the day and triple pt low developing over or just NW of the region Wed Eve and intensifying as it tracks into New England Wed night Overrunning rain likely develop Wed morning. With closer mid/upper level forcing and low- level jet once again pumping in +3-4 std pwat...potential exists for another period of moderate/heavy rain Wed Aft/Eve in the vicinity of warm front and developing triple pt low. More pronounced marginal elevated instability should support embedded tstm activity during this time. With strong forcing and good convergence along the cold front..potential for organized fine line/squall line development Wed Eve with a conditional low prob of strong/severe wind gusts. This development is explicitly generated in several high-res models. At this point there is uncertainty on timing of shortwave energy...track of the triple pt low and placement of llj/warm sector...which are keys in determining heavy rain axis and any organized convective threat. Cold front pushes east after midnight as shortwave energy pivot through...bring rain to an end. Drying conditions expected late Wed Night on gusty westerly flow. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Upper low will be centered to our north on Thursday with a somewhat cyclonic flow aloft over our area. At the surface, high pressure builds in slowly. It`ll be a breezy day, but still with temperatures above normal as cold air advection will be weak and gradual on a west flow. Have bumped up high temp forecast a couple of degrees from a guidance blend. Cooler conditions on Friday as temps aloft drop, but mixing up to 850 mb still expected on a moderate westerly flow. Again, went a little above guidance for high temps. A weak cold front or trough of low pressure may move through during the afternoon, and this could cause a few sprinkles over the far NW zones and perhaps in the vicinity of the east end of LI. Not much of a change in the pattern for Saturday, just slightly cooler and will leave out any mention of sprinkles. There is still some pretty big differences among the global models regarding the next system to potentially affect the forecast area. ECMWF at least has trended toward GFS and CMC/GGEM with slowing down the onset of possible PCPN from low pressure developing in the southern states. Still the fastest among the three models, it doesn`t bring any PCPN over here until late Sunday night. With this trend, have removed PCPN from the forecast for the daytime on Sunday, but will still leave in a chance of PCPN for the night in the event the other models start speeding up this system. Will cap PoPs at chance for Monday with the given uncertainty in timing and track of this low pressure system. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/...
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Low pressure over West Virginia will track through the region tonight. A warm front will approach the area on Wednesday. Ceilings and visibility will continue to lower through this afternoon with rain. As the rain ends tonight, a period of improvement is possible. However, if fog develops during this window, IFR or lower can be expected. Additional rain will develop by late Wednesday morning. Southeasterly winds will veer to the south this afternoon, and to the west tonight. Gusts may be limited, especially in the steadiest rain. Winds will back to the southeast again on Wednesday. Winds at 2000 ft of around 50 kt can be expected through the early evening, resulting in low level wind sheer. ...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: Occasional gusts to around 25 kt possible this afternoon and evening. KLGA TAF Comments: Occasional gusts to up to 25 kt possible this afternoon and evening. KEWR TAF Comments: Occasional gusts to around 20 kt possible this afternoon and evening. KTEB TAF Comments: Occasional gusts up to 20 kt possible this afternoon and evening. KHPN TAF Comments: Occasional gusts up to 20 kt possible this afternoon and evening. KISP TAF Comments: Occasional gusts to around 25 kt possible this afternoon and evening. .OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY... .Rest of Wednesday...IFR with rain. Southerly winds up to 20 kt. .Thursday...VFR with westerly flow. .Friday...VFR with westerly flow. .Saturday...VFR with northwesterly flow. .Sunday...VFR with northwesterly flow.
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&& .MARINE... SCA wind gusts expected to develop over all waters this morning...with a short period of marginal gale gusts possible on the ocean this late this afternoon/eve. For the nearshore waters...the gale threat appears to be more of an occasional gust. Any embedded thunderstorms this aft/eve could bring down some locally higher gusts. Seas should build to 8 to 12 ft on the ocean by this evening. Areas of fog will also be possible late today into Tonight as a high dewpoint airmass moves over the waters Ocean seas on Wed should remain elevated through the daytime Wed. Winds also increase Wed Aft/Wed Eve as the next storm approaches, with SCA winds gusts likely on all waters, and possibly reaching gale force on the ocean Wed Night just ahead of an approaching cold front. Embedded thunderstorms could bring down some locally higher gusts...with even potential for an organized squall line. SCA conditions remain likely on the ocean waters through Saturday night. Elsewhere, periods of 25 kt gusts will be possible primarily over the eastern sound and bays through Friday night, with a chance that all non-ocean waters remain below criteria on Saturday. && .HYDROLOGY... Around 1-1.5 inches of rainfall is expected today into this evening...with locally higher swaths of 2+ inches possible. The main threat is for minor urban and poor drainage flooding...with a low prob of flash flooding if 2+ inch swath aligns over urban corridor. Another 1-2 inches of rainfall is possible Wed into Wed Night. Once again the main threat will be for minor urban and poor drainage flooding. No significant PCPN expected from Thursday through at least Sunday. A chance of PCPN returns Sunday night into Monday. && .CLIMATE... Much needed precipitation is expected across the Tri-State area Tuesday into Wednesday which should aid in cutting the significant departures from normal we have seen so far for this year. Through yesterday Central Park was 9.16 inches below normal for the year to date with respect to precipitation. Looking closer at precipitation stats, so far this year only 36.35 inches of precipitation has fallen at The Park. Since records started in 1869 only 41 calendar years, or roughly 28 percent, have had less than 40 inches of precipitation for the calendar year. Since 1990 though this has only happened twice: in 2001 The Park measured 35.92 inches and in 2012 The Park measured 38.51 inches. Going back to 1970 another 3 years would join this list - 1970, 1981 and 1985. For some of other major climate stations, the last 2 years combined have also been significantly dry. Newark Airport only saw 38.98 inches of precipitation last year and this year so far was at 32.41 inches. The last time Newark had 2 consecutive years with less than 40 inches of precipitation was in 1980 and 1981 which saw a significant drought in North Jersey. At Bridgeport, last year a total of 35.03 inches of precipitation was measured and this year`s total stands at 33.30 inches. Bridgeport has not had two consecutive years with less than 40 inches of precipitation since the stretch from 1985-1988. The bottom line...we`ve been dry and it will be interesting to see how things finish up the year. This will be something for us to watch during December. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 7 PM EST this evening for ANZ335- 338-345. Small Craft Advisory until 10 PM EST this evening for ANZ330- 340. Small Craft Advisory until 6 PM EST Wednesday for ANZ350-353- 355. && $$ SYNOPSIS...JC/NV NEAR TERM...Tongue SHORT TERM...NV LONG TERM...JC AVIATION...JMC MARINE...JC/NV HYDROLOGY...JC/NV CLIMATE...

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