Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 260811 AFDOKX Area Forecast Discussion National Weather Service New York NY 411 AM EDT Tue May 26 2020 .SYNOPSIS... Offshore high pressure will continue ridging across the area through Thursday. A slow moving cold front approaches Friday and moves through Saturday. High pressure returns Sunday into early next week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Some fog remains across the area this mrng. Obs indicate patchy dense at the most, so have gone with that wording in the fcst and issued an SPS. It is possible that the moisture is too deep attm to get widespread dense per the model time heights. The fog and stratus burns off gradually today. A model consensus was used for burnoff time, but this is always tricky especially near the coast. The stlt fog product shows extensive fog over the ocean. It is entirely possible that a fog bank sets out there today, possibly even hugging the Long Island coast based on the sly llvl flow. The onshore flow will limit the potential warmth today, with highs ranging from the lwr 80s in the nwrn interior to upr 60s along the oceanfront. The NBM was followed with some tweaks, particularly invof Montauk where the numbers seemed too low based on the MOS. If the fog hangs in however this will be a major bust as temps could struggle to even get to 60. There is a moderate rip current risk today. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... More fog is expected tngt. There appears to be more dry air aloft which could tip the scales towards more widespread dense. Patchy dense has been included in the fcst for now. A similar burnoff challenge is expected for Wed, and to account for the uncertainty a model blend was used. For temps, went closer to a MAV/MET blend which brought the n shore of Long Island up and the sern CT coast down. Elsewhere it was very similar to the NBM. The NBM was used for the overnight temps with some manual adjustments. There is a moderate rip current risk for Wed. && .LONG TERM /THURSDAY THROUGH MONDAY/... The core of the upper ridge will begin to break down on Thursday and shift over the Western Atlantic. However, the surface ridge looks to remain in tact, which will likely keep much of the region dry through Thursday. Patchy fog and low stratus are also likely Thu morning with a continued onshore flow and warm air moving over ocean temperatures in the lower 50s. Any stratus and fog likely diminish with daytime heating, but it could linger near the coast. The ridging will boost temperatures away from the immediate coast into the upper 70s to near 80 Thursday. Temperatures closer to the coast will be held down in the lower to middle 70s and some places more exposed to the onshore flow could stay in the 60s. Temperatures could also be held down if stratus and/or fog hang on longer. There could be a few showers that traverse around the periphery of the ridge as it breaks down Thursday, mainly N and W of NYC. The upper ridge continues to break down Thursday night into Friday with a more significant upper short wave trough digging into the Great Lakes and southeast. There may be some vort energy traversing around the ridge from the southeast Thursday night into Friday morning which could bring some higher probability of showers. Otherwise, the main area of forcing will be with the shortwave and its associated cold front, which models have been slowing down over the last several runs. There may be a prefrontal trough developing to our NW Friday with some enhanced convection, but the highest probabilities for showers and possible thunderstorms may occur Friday night into the first half of Saturday with the actual cold front. Forecaster confidence is low regarding the timing of the front, so have continued to go with chance probabilities. Have increased them on Saturday due to the trend for a slower frontal passage. Conditions should improve late Saturday into Saturday night as the upper trough moves over the Eastern States. High pressure builds down out of Southern Canada for Sunday into early next week with dry conditions expected. Conditions will become increasingly more humid into the end of the week. The timing of the cold front will ultimately determine how warm temperatures reach Friday into Saturday. Highs should remain cooler near the immediate coast, in the lower to middle 70s, with temperatures in the upper 70s and lower 80s away from the coast. Temperatures trend cooler and possibly below normal Sunday into early next week. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... Offshore high pressure will continue to ridge across the area the next several days. This will keep the terminals under a weak, mainly moist onshore flow. Widespread LIFR/VLIFR conditions overnight with what looks to be a quicker improvement to VFR later this morning. Still though, there remains some uncertainty with how quickly conditions improve. Have leaned toward a more optimistic solution based on the shallow nature of moisture and time of year. Then a potential repeat Tuesday night with not much change in the airmass. Winds overall light and variable, then calm overnight. Winds then become E-SE in the morning, and then more southerly in the afternoon at 5 to 10 kt. .OUTLOOK FOR 06Z WEDNESDAY THROUGH SATURDAY... .Wednesday-Thursday...VFR. Chance IFR with areas of fog during the overnights into early morning hours each day. .Thursday night-Saturday...MVFR possible. A Chance of showers and thunderstorms. && .MARINE... Areas of dense fog can be expected thru this mrng. There is a chance the fog could persist all day, especially on the ocean. Additional fog development is likely tngt into Wed. Winds and seas however will remain blw sca lvls thru Wed. High pressure over the Western Atlantic will keep winds and seas below SCA levels Thursday. More fog is possible Wed ngt and Thursday morning. Winds increase ahead of a cold front on Friday and could come close to 25 kt on the ocean. Ocean seas may also build to around 5 ft. Winds should gradually weaken Friday night into Saturday, but 5 ft ocean seas may persist into the first half of the weekend. && .HYDROLOGY... No significant hydrologic impacts are expected through Thursday. Showers and thunderstorms are are possible Friday into Saturday with a chance for minor urban and poor drainage flooding. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO35 (162.55 MHz) is undergoing its final stages of testing, and is operating at full power. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Dense Fog Advisory until 10 AM EDT this morning for ANZ330-335- 338-340-345-350-353-355. && $$

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