Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 231102 AFDOKX Area Forecast Discussion National Weather Service New York NY 702 AM EDT MON MAY 23 2016 .SYNOPSIS... Low pressure off the North Carolina coast moves slowly north today and tonight, then drifts northeast Tuesday and Tuesday night, remaining offshore and passing south and east of the region. High pressure will then briefly follow for Wednesday and Thursday morning with a cold front stalling in the vicinity Thursday afternoon or night. The front returns north as a warm front on Friday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A weak surface coastal low, 1005 mb, will move slowly north today as a mid and upper cutoff low drifts along the mid Atlantic coast. This low and associated cold pool will have vort maxes rotating around the cutoff low. In addition a weak surface trough will be developing along the coast. Initial clearing will allow for daytime heating and surface based instability to increase. Both the surface trough and upper low will provide convergence and lift for scattered showers to develop. And with the instability and cape increasing to 200 to 400 j/kg this afternoon, isolated thunderstorms will be possible. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/... The surface low continues to drift north and northeast tonight through Tuesday night, remaining offshore, as the mid and upper cutoff low also drifts along the coast. With the low a little closer to the coast tonight and additional energy rotating through, there will be a better, likely, chance of showers. There may be isolated thunder early, however, cape and instability will be decreasing. Not all areas will see precipitation, and will be dependent on where the low and upper low drift. Once again, Tuesday afternoon thunderstorms will be possible as a surface trough develops and the low drifts east of the region. Precipitation ends during Tuesday evening as the upper low begins to fill and open, moving farther to the east, and height will be rising at all levels after 03z Wednesday. Could be a rather sharp end to the precipitation. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Ridging aloft on Wednesday will help slow down a cold front sinking south across the Northeast. Insufficient moisture and lift should therefore keep the cwa dry. Mixing to 850 mb, where temps are forecast to rise to around 13C, along with a mostly sunny sky and SW winds will bring high temps about 10-15 degrees above normal across the entire area. The cold front weakens and stalls over us on Thursday as ridging aloft continues. Chance of afternoon tstms from around the city and points west where better instability will reside. Subsidence will limit mixing more than on Wednesday, so expecting high temps to be a couple of degrees cooler on average versus Wednesday. Friday and Saturday look to be similar days with ridging aloft and a weak SE-S wind flow. This will probably limit chances of showers/thunderstorms to inland sections both days, and chances don`t appear to be very high due to limited moisture and/or capping from ridging aloft. Models however hint at the possibility of an MCS moving through late Thursday night into early Friday morning, so a more widespread rainfall is still a possibility. High temps both days still averaging above normals in spite of a limited mixing profile. It appears that Sunday could feature deeper mixing,and along with rising temps aloft, high temps could end up a few degrees warmer than currently forecast. Didn`t want to stray too far from WPC guidance this far out in time, which is warmer than superblend. Highs well into the 80s for some inland spots. Once again, limited chances of showers/storms focused inland. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... Low pres remains nearly stationary off the Delmarva into Tue. A lot of variability in the flow thru the taf period. Nearly calm this mrng then ne flow attempts to develop. Sea breeze flow then expected to take over by early aftn. Wind direction will become vrb tngt as the sea breeze circulation weakens. Mainly vfr thru this eve...although some sct shwrs possible aft 16-18z. Isold tstms cannot be ruled out...particularly from the city into the Hudson Valley and nern NJ. For tngt...mvfr or lower in rain aft 5z. ...NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component fcsts can be found at: http:/ KJFK TAF Comments: No unscheduled amendments expected this mrng. Low prob of a tstm this aftn. KLGA TAF Comments: No unscheduled amendments expected this mrng. Low prob of a tstm this aftn. KEWR TAF Comments: No unscheduled amendments expected this mrng. Low prob of a tstm this aftn. The afternoon KEWR haze potential forecast is GREEN...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: No unscheduled amendments expected this mrng. Low prob of a tstm this aftn. KHPN TAF Comments: No unscheduled amendments expected this mrng. A tempo may be needed for tstms this aftn...mainly aft 18z. KISP TAF Comments: No unscheduled amendments expected. .OUTLOOK FOR 12Z Tuesday through Friday... .Tuesday...periods of mvfr in -shra and/or tstms. .Wednesday-Thursday...vfr. .Thursday night...low chc of mvfr -shra. .Friday...mvfr possible in tstms. && .MARINE... Small craft seas remain on the ocean waters this morning, mainly from swells from departing low pressure that was meandering near Nova Scotia. Seas are expected to fall below 5 feet by late this morning. The general small craft hazard was converted to a small craft for hazardous seas and runs through 11 am this morning. Otherwise, a rather weak pressure gradient force will be across the waters today through Tuesday night as a weak low off the North Carolina coast moves north today and tonight, and northeast Tuesday and Tuesday night. Winds will remain below small craft levels today through Tuesday night. And seas on the ocean waters will remain below small craft once the seas subside this morning. Sub-sca conditions will prevail for the rest of the forecast period with the lack of a strong pressure gradient or significant swell. && .HYDROLOGY... A long periods of generally light precipitation is expected today through Tuesday evening with 1/2 to 3/4 of an inch expected. Locally higher amounts are possible if any thunderstorms develop this afternoon and Tuesday afternoon. Widespread significant rainfall is not expected for the rest of the week. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory for hazardous seas until 11 AM EDT this morning for ANZ350-353-355. && $$ SYNOPSIS...JC/MET NEAR TERM...MET SHORT TERM...MET LONG TERM...JC AVIATION...JMC MARINE...JC/MET HYDROLOGY...JC/MET is the U.S. government's official web portal to all federal, state and local government web resources and services.