898 FXUS61 KOKX 091819 AFDOKX Area Forecast Discussion National Weather Service New York NY 219 PM EDT Tue Oct 9 2018 .SYNOPSIS... A broad area of high pressure will set up over the Atlantic through Wednesday, then gradually weaken Wednesday night into Thursday as a cold front approaches. The front will pass through Thursday night into Friday as the post-tropical remnant of Michael passes well to the southeast. High pressure will then build in for the weekend. A warm front will then pass through Sunday night into Monday morning, followed by a cold front Monday afternoon and night. Please refer to National Hurricane Center products for further details on Michael. && .NEAR TERM /THROUGH TONIGHT/... Latest satellite imagery shows some clearing working in from the SW across central NJ. Additionally, hires model data all supporting some clearing this afternoon, so trending toward partly sunny the next few hours. High pressure will continue to retreat offshore this afternoon with a warm, humid S-SW flow. If more clearing occurs than forecast, expect highs to verify a few degrees warmer, particularly across NYC. For tngt, winds slacken and fog is likely to develop across much if not all of the CWA. Cirrus and SW flow could be limiting factors, but with dewpoints starting out in the low 70s, confidence was high enough to go with areas as opposed to patchy. Used SuperBlend for temps, which was slightly warmer due to the expected fog and lack of good radiational cooling conditions. Overnight lows appear to be about where daytime highs should be...so a mild night. && .SHORT TERM /WEDNESDAY/... An upper ridge will remain over the Eastern seaboard, so a continuation of the warm and humid wx can be expected. After the mrng fog burns off, there will still be some pockets of residual stratus as well as thickening cirrus. The subtropical high cloud shield ahead of Michael was already thru WV so these will likely reach the CWA by Wed. The position of the ridge however should help to suppress convective initiation, so the fcst has been kept dry. A blend of the guidance and raw model data was used for temps, which will remain 10 degrees or more abv climo. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... As the offshore high weakens, a tropical moisture plume well in advance of Hurricane Michael will begin to stream into the area late Wednesday night into Thursday ahead of an approaching front. One could say this qualifies as a tropical predecessor rainfall event, as the moisture feed will be driven in part by the deep layer S-SW flow between the offshore high and Michael after the storm makes landfall and moves through the Southeast states as a tropical storm. PW increases to 2.25-2.5 inches by Thu afternoon with the approach of the front as a southerly H9 LLJ maxes out at 50 kt, and heavy rain is possible. May also have to watch for rotating convection capable of producing damaging winds or a brief tornado from NYC metro north/west, where a low sfc-based CAPE, high-shear environment may set up, with SBCAPE 500 J/kg and 0-1 km helicity 200-300 m2/s2. Rain chances should remain high especially across Long Island and SE CT going into Thu night and Friday, with the front making only slow progress offshore as Michael passes to the SE as a potent post-tropical storm. Direct heavy rainfall from Michael should however remain well offshore. Winds are not forecast to be especially strong as Michael passes to the SE, but that could change especially for Long Island if the storm makes a closer pass at the area than expected. High pressure and cooler wx should follow for the weekend, with highs only 55-60 on Sat and 60-65 on Sunday. A frontal system passing through on Monday should bring milder conditions, also the chance of showers and possibly a tstm. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... High pressure off the NJ coast will drift farther off the coast through tonight and into Wednesday morning. Conditions will be mainly MVFR, with periods of VFR this afternoon. Ceilings will be lowering once again this evening and tonight, becoming IFR and as low as LIFR after 04Z. There is some uncertainty with the timing and how low ceilings will become. IFR to LIFR fog is possible late tonight at locations outside of the NYC metro terminals. Conditions improve back to VFR late Wednesday morning or into the afternoon. Improvement may be quicker than currently forecast Wednesday morning. Winds S to SW 5 to 10 KT, becoming SW tonight around 5 KT, with light and variable winds outside of the NYC terminals. Winds will be SW to S 5 to 10 KT Wednesday. 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: VFR becoming MVFR once again after 22Z, and then IFR. Timing of the lowering is uncertain and may take longer than currently forecast. KLGA TAF Comments: VFR becoming MVFR once again after 22Z, and then IFR. Timing of the lowering is uncertain and may take longer than currently forecast. KEWR TAF Comments: VFR becoming MVFR once again after 22Z, and then IFR and LIFR. Timing of the lowering is uncertain and may take longer than currently forecast. KTEB TAF Comments: VFR becoming MVFR once again after 22Z, and then IFR and LIFR. Timing of the lowering is uncertain and may take longer than currently forecast. KHPN TAF Comments: IFR with periods of MVFR this afternoon. Conditions lower to LIFR this evening. There is uncertainty as to the timing of the lower conditions this evening. KISP TAF Comments: MVFR, with a brief period of VFR possible this afternoon. May remain VFR a little longer than forecast. IFR tonight and then LIFR late tonight. Timing of the lowering is uncertain and may take longer than currently forecast. .OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY... .Wednesday afternoon and night...MVFR, becoming VFR around 18Z, then becoming MVFR and IFR at night. Chance of showers toward Thursday morning. .Thursday...MVFR or lower possible. Showers, with a chance of thunderstorms, heavy rainfall possible. S winds 15-20KT, gusting 20-30 KT. LLWS possible. .Friday...MVFR with showers and isolated thunderstorms ending in the morning, then becoming VFR. Winds NW G20-25kt. .Saturday-Sunday...VFR. && .MARINE... Winds and seas will remain blw sca lvls thru Wed with a broad area of hipres centered over the Atlc. SCA conditions should develop Thu afternoon via strengthening S flow ahead of a cold front, and there is a chance that gusts on the ocean waters could peak briefly at minimal gale force late Thu. SCA conds expected to continue on the ocean waters from Thu night into at least Fri night and possibly Sat morning as winds turn N then NW with the passage of Michael well to the SE. Worst case scenario if Michael makes a closer approach than expected could mean some gale force wind gusts for the ocean waters on Friday. && .HYDROLOGY... Rain Thu afternoon into Thu evening could be heavy at times as a southerly LLJ transports a deep tropical moisture plume into the area ahead of a cold front. While total rainfall from Thu into Fri should range from 1-2 inches, localized amounts of 2-4 inches and associated areal/flash flooding can't be ruled out, so will mention in the HWO. && .TIDES/COASTAL FLOODING... High tide has passed and the threat of isolated minor coastal flooding across the south shore back bays of western Long Island has ended. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO35 (162.55 MHz) remains off the air for an extended period of time. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$