Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 230029 AFDOKX Area Forecast Discussion National Weather Service New York NY 829 PM EDT FRI JUL 22 2016 .SYNOPSIS...
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A cold front approaches tonight and will move across early Saturday. Another cold front will pass across the area Saturday night. High pressure will then be in control on Sunday before a cold front moves across the area Monday into Monday night. High pressure returns for Tuesday through Thursday. Another front moves through the area on Friday.
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&& .NEAR TERM /THROUGH SATURDAY/...
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Spatial coverage of convection has been quite limited so far this evening. Accounting for mesoscale models such as HRRR, ARW and NMM, followed a relative more active pattern exhibited by their respective forecast reflectivity. Without much forcing aloft as the jet streak northwest of the region has the local region in a quadrant that does not favor lift, relatively higher chances for convection will be tied with the surface trough approaching, leftover boundaries from daytime seabreezes, and remaining low level instability. Surface CAPE values will be still be near 100 J/kg into this evening so essentially left a chance of showers and thunderstorms. However, noting recent trends, lowered the chances to mostly 30 percent or less. Mesoscale models show the peak convective activity between 0 and 3Z. Temperatures and dewpoints were on track. Min temperatures overnight will only lower in the mid to upper 70s for much of the urban and coastal regions with mid 60s to lower 70s for the more interior and rural sections. A high risk for rip current development at ocean beaches remains through this evening due to southerly wind waves increasing to 3 to 5 ft and a residual 2 ft SE swell.
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&& .SHORT TERM /SATURDAY THROUGH 6 PM SATURDAY/... Seriously, despite the passage of a trough this evening, we will not cool off much for Saturday and another hot day will be seen across the area. However, with winds trending toward the west to northwest at all levels, this will advect in drier air that will drop surface dewpoints into the 50s to lower 60s by the afternoon. Thus, heat index values will not be as high as today and in some ways it may feel a little better. However, the west to northwest flow will `downslope` and thus drag the hotter air out even toward the coast. I leaned toward the hotter end of statistical guidance for highs as a result. The Heat Advisory will remain up for The City and we added urban parts of Essex and Union Counties in NJ as well as Hudson County where actual temperatures could get to 100 (most likely at Newark which would be about the average highest temperature of the year). No records are in threat at Newark or in the City though as we are competing against the Heat wave of 2011 when Newark set an all-time record high of 108. Another more vigorous trough passes across New England tomorrow evening, both aloft and at the surface. There may be enough moisture in interior new London County to pop off a shower or thunderstorm but otherwise it should be dry. Saturday night will be a little cooler. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... High pressure builds into the area on Sunday. High temperatures on Sunday will be in the upper 80s to low 90s for most areas, but will be in the low to mid 90s for NYC, portions of NE NJ, and southern portions of the Lower Hudson Valley. With a west to northwest flow, dewpoints should not be as high as Saturday, resulting in heat indices below 95 degrees. High pressure moves offshore Sunday night. Meanwhile a low pressure over eastern Canada will push its associated cold front through the area Monday, scattered showers and thunderstorms will develop over western areas and spread east as that front advances and pushes through the region Monday night. Highs on Monday will be in the low to mid 90s, and heat indices will top off in the mid to upper 90s. Monday night will be very warm and humid with lows near 80 around NYC, and in the low to mid 70s elsewhere. Areas of fog are likely as well. High pressure builds into the area on Tuesday, ushering in cooler and dryer air. Highs on Tuesday will be in the low to mid 90s, and with surface dewpoints in the 60s, heat indices will once again top off in the mid 90s. High pressure will continue to build across the area through Thursday. Temperatures will be in the upper 80s to low 90s on Wednesday, and mid to upper 80s on Thursday. Another cold front is then forecast to impact the local area later on Thursday and into Friday. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... A weak cold front approaches tonight and moves through towards daybreak. Isolated convection this evening, but unlikely to affect any of the local terminals. Otherwise, VFR conditions expected through the TAF period. There is a low chance for some patchy fog and MVFR vsbys early Saturday morning outside the NY metro. S-SW winds will diminish this evening. WNW flow is likely tomorrow with gusts to 20KT in the afternoon. Coastal sea breeze development. 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: There is a low chance for a SHRA or TS in the terminal area around 03Z. High Confidence of W-WNW flow on Saturday. KLGA TAF Comments: There is a low chance for a SHRA or TS in the terminal area around 03Z. High Confidence of W-WNW flow on Saturday. KEWR TAF Comments: There is a low chance for a SHRA or TS in the terminal area around 03Z. High Confidence of W-WNW flow on Saturday. KTEB TAF Comments: There is a low chance for a SHRA or TS in the terminal area around 03Z. High Confidence of W-WNW flow on Saturday. KHPN TAF Comments: There is a low chance for a SHRA or TS in the terminal area around 03Z. High Confidence of W-WNW flow on Saturday. KISP TAF Comments: There is a low chance for a SHRA in the terminal area around 04Z. High Confidence of W-WNW flow on Saturday. .OUTLOOK FOR 00Z SATURDAY THROUGH WEDNESDAY... .SAT NGT through SUN NGT...VFR. .MON...Mainly VFR, except MVFR or lower possible in scattered late day/evening thunderstorms. .TUE and WED...VFR. && .MARINE...
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SCA conditions remain on the ocean waters and South Shore bays. The wind gusts will be 20-25 kt across the ocean and South Shore Bays and ocean seas will be 4-6 ft this evening. South Shore Bays will have winds drop below SCA by late this evening. All other waters will remain below SCA tonight. Overall the pressure gradient will decrease tonight so winds will gradually lower but ocean seas will take longer to decrease. A chance of showers and thunderstorms remains for the waters for late this evening with even lower chances overnight. Lighter offshore flow on Saturday will keep waves on the low side. High pressure will influence the area waters on Sunday. A cold front moves through the waters Monday night, and then high pressure returns for the middle of next week. Below small craft advisory conditions expected for the extended period.
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&& .HYDROLOGY...
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Any stronger thunderstorms that get going this evening could produce locally heavy downpours given PWATs around 1.5 inches. The main threat looks to be more on the side of localized minor ponding or poor drainage flooding in urbanized areas. Scattered showers and thunderstorms will impact the region Monday afternoon and Monday night, resulting in the potential for locally heavy rain.
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&& .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...Heat Advisory until 7 PM EDT Saturday for NYZ072>075-176-178. High Rip Current Risk until 9 PM EDT this evening for NYZ075- 080-081-178-179. NJ...Heat Advisory until 7 PM EDT Saturday for NJZ006-106-108. MARINE...Small Craft Advisory until 6 AM EDT Saturday for ANZ350-353- 355. Small Craft Advisory until 11 PM EDT this evening for ANZ345. && $$ SYNOPSIS...Stachelski NEAR TERM...Stachelski/JM SHORT TERM...Stachelski LONG TERM...FIG AVIATION...Tongue MARINE...Stachelski/FIG/JM HYDROLOGY...Stachelski/FIG

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