Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/13/21


Area Forecast Discussion
National Weather Service New York NY
922 PM EST Sun Dec 12 2021 .SYNOPSIS... High pressure settles southwest of the region Monday into Monday night before moving offshore. A second area of high pressure builds to the north Tuesday into Tuesday night. High pressure moves off the New England coast Wednesday and Wednesday night allowing a warm front to approach and move north Thursday. A cold front moves across the region Thursday night into early Friday as the associated low tracks well to the north. High pressure briefly builds Friday as a wave of low pressure quickly approaches Friday night and affects the area into the beginning of next weekend. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... Updated for current conditions, mainly dew points and temperatures. Forecast remains on track. Upper ridging and drier air continue building in from the west. At the surface, high pressure was located southwest of the area, and dry conditions are expected through the period. There may be some scattered cirrus clouds late tonight as they spill over the ridge. Dewpoints tonight will bottom out in the upper teens to lower 20s, however westerly winds should remain up, 5-10 mph, mitigating any possible radiational cooling. Low temperatures therefore should remain in the mid to upper 30s across NYC and coastal locations and the upper 20s in the interior and across the Long Island Pine Barrens, under the westerly flow. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... Surface high pressure and dry conditions will dominate the short term. The high south of the area will weaken and slide offshore Monday afternoon and evening, while a secondary surface high builds north of the area by Tuesday night. Breezy southwesterly to westerly winds and dry conditions will continue on Monday, as high pressure remains to our south. Gusty winds are supported by HRRR 10m gust potential, which is depicting 15-20 mph gusts for much of the day Monday, especially across the eastern CWA. For temperatures, went slightly below MOS, to near the NBM 90th percentile for highs for Monday, in the low to mid 50s, given the predominant westerly flow, which is 5-8 degrees above normal. Low temperature reasoning remains similar to Sunday night for Monday night. Winds will begin to diminish toward daybreak on Tuesday, however, potentially allowing for a few hours of radiational cooling under nearly cloudless skies. Forecast lows range from the mid and upper 30s for coastal spots, with upper 20s and low 30s inland. High pressure builds in from the north on Tuesday, again keeping the area dry under large scale subsidence. High temperatures will be similar to Monday, in the low and mid 50s areawide. Winds veer to the northeast and east late Tuesday as the high to the north begins to move offshore. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... The models and ensembles continue to be in good agreement through much of the extended forecast period, especially for the frontal system that will be impacting the region Thursday and Thursday night. Some uncertainty develops with the strength and placement of a frontal wave developing across the central US and tracking quickly through the northeast and mid Atlantic states for the beginning of next weekend. There also remains good continuity from previous forecasts, so mainly used the NBM guidance through the extended. Temperatures from Wednesday into Saturday night remain above normal with the peak of the warmth still expected for Thursday as a deep southwesterly flow brings well above normal temperatures to the east coast. Guidance has increased the highs slightly for Thursday, and with the highly anomalous warmth expected leaned toward the 75 percentile for Thursday`s highs. As a result, at this time, temperatures will be approaching record levels at a few of the climate sites. Temperatures will be near 15 degrees, to possibly as much as 20 degrees, above normal for Thursday. For Saturday there is uncertainty as to the amplification of the northern stream longwave trough that tracks quickly from the Pacific northwest Thursday and to the Great Lakes region Saturday. Behind this system temperatures are expected to return to seasonal levels for Sunday. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... VFR through the TAF period with high pressure building south of the region. W-SW winds 5-10 kt are expected tonight, strongest at NYC terminals. SW winds continue on Monday and increase to 10-15 kt. Gusts 17-20 kt should occur middle to late morning and continue into the afternoon, ending late in the afternoon. SW winds fall back to 10 kt or less in the evening. NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Gusts on Monday may end up occasional. .OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY... .Monday night-Wednesday...VFR. .Thursday...Mainly VFR, slight chance of showers at night. .Friday...VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... Expecting SCA conditions to continue through Monday and potentially Monday night for the ocean waters, mainly for seas. However, gusts may approach SCA levels on the ocean waters overnight as high pressure builds to the south and the gradient increases once again. Even across the Sound east of the mouth of the Connecticut river and possible the eastern bays may have gusts approaching SCA levels later tonight. Once conditions improve on the ocean waters late Monday or Monday evening, sub SCA conditions will remain into Tuesday night. Winds and seas will be below SCA levels Wednesday and Wednesday night across all the forecast waters. An increasing southwesterly flow behind a warm front Thursday may allow for gusts to approach or exceed SCA levels across the ocean waters as seas build to SCA levels. Small craft conditions are then expected on the ocean waters into early Friday, with conditions subsiding below SCA levels from west to east during the day and possibly into Friday evening as low pressure tracks well to the north and high pressure builds in from the west. && .HYDROLOGY... No hydrologic impacts are anticipated through Sunday. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 7 PM EST Monday for ANZ350-353-355. && $$ SYNOPSIS...DBR/MET NEAR TERM...DBR/DS SHORT TERM...DBR LONG TERM...MET AVIATION...DS MARINE...DBR/MET HYDROLOGY...DBR/MET