Sandy Hook NJ to Fire Island Inlet NY out 20 NM Marine Forecast
|Tonight...W Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 3 Ft.|
|Sun...Sw Winds Around 10 Kt. Seas 2 To 3 Ft.|
|Sun Night...W Winds 5 To 10 Kt With Gusts Up To 20 Kt, Becoming Nw After Midnight. Seas 2 To 3 Ft. Chance Of Showers And Tstms In The Evening.|
|Mon...Ne Winds 5 To 10 Kt, Becoming S In The Afternoon. Seas Around 2 Ft. Chance Of Showers In The Morning, Then Showers Likely With Chance Of Tstms In The Afternoon. Vsby 1 To 3 Nm.|
|Mon Night...Sw Winds 5 To 10 Kt. Seas 2 To 3 Ft. Showers Likely With Chance Of Tstms In The Evening, Then Showers Likely After Midnight. Vsby 1 To 3 Nm In The Evening.|
|Tue...W Winds Around 10 Kt, Becoming Nw In The Afternoon. Seas 2 To 4 Ft. Showers Likely, Mainly In The Morning.|
|Tue Night...Nw Winds 5 To 10 Kt. Seas 2 To 4 Ft.|
|Wed...N Winds 5 To 10 Kt, Becoming W In The Afternoon. Seas 2 To 3 Ft.|
|Wed Night...Sw Winds Around 5 Kt, Becoming Nw After Midnight. Seas Around 2 Ft.|
|Thu...N Winds 5 To 10 Kt, Becoming Se In The Afternoon. Seas Around 2 Ft.|
|Thu Night...S Winds Around 10 Kt, Becoming Sw After Midnight. Seas Around 2 Ft. Winds And Seas Higher In And Near Tstms.|
|Area Forecast Discussion|
National Weather Service New York NY
808pm EDT Sat July 20 2019
Synopsis: Region will reside between high pressure over the western Atlantic and a cold front dropping south across eastern Canada. The cold front will move across the region late Sunday afternoon into the evening. A wave of low pressure moves along the front Monday and Monday night as it slowly pushes through the local area. High pressure then returns for the remainder of the week.
Near Term - Until 6am Sunday Morning
Forecast is mainly on track. Isold pulse showers/tstms have developed just outside of the local forecast area so have expanded the schance probability of precipitation a bit this evening. Slight adjustments also made to T/Td and sky based on current conds and trends.
Otherwise, high heat and humidity will remain the focus into this evening with much of the region reporting heat indices 100 to 105.
Forecast area will remain at the southern edge of the westerlies with broad upper ridging across the southern half of the country merging with the subtropical high over the western Atlantic. Anomalously warm heigheights aloft, deep westerly flow, and high boundary layer moisture (high humidity) will result in dangerous heat indices through early this evening. Even overnight, the urban corridor and coastal sections will see heat indices in the mid 80s to around 90. While there will be some relief overnight, it will remain a hazard for living premises that are not ventilated well or do not have AC.
Lows will be in the upper 70s to lower 80s by daybreak. This almost 15 degrees above normal.
There is a moderate risk of rip currents at Atlantic Ocean beaches through this evening
Short Term - 6am Sunday Morning Through Sunday Night
Upper low descending south and east from Hudson Bay will send height falls across eastern Canada as well as cold front across the Great Lakes toward the region. Even so, a deep-layered westerly flow will result in another day of high heat and humidity with heat indices once again in the 105-110 range.
There are a few wild cards in play that could limit the heat somewhat. This includes a more westerly flow with the potential for some drier air aloft mixing down to the surface. It may be just enough to keep values lower than Saturday. Additionally, instability clouds ahead of the approaching cold front and convective debris form upstream may filter into the region in the afternoon.
Preference at this time was to go on the warmer side of the guidance. Even if some drier air is realized in the low levels, this may in fact allow the airmass to heat up further. Much of the area will see highs in the lower to mid 90s, with readings near 100 in the urban corridor of NE NJ.
Cold front and pre-frontal trough will move into the area late afternoon/early evening. While the airmass ahead of it is clearly hot and unstable, it may be too warm aloft with capping and not enough forcing to break it. Wind shear is also weak and not favorable for organized convection. Thus, there are only low chances for showers and thunderstorms in the forecast.
Cold front moves through in the evening with any showers pushing to the south. Drier and cooler air will gradually filter in overnight into Monday morning.
For Sunday at the Atlantic Ocean beaches, there will be a low rip current risk
Long Term - Monday Through Saturday
The period starts with a frontal boundary near the local area. An upper level trough digging through the Great Lakes and Ohio Valley Mon/Monday night will spawn a surface low on this boundary in the Ohio Valley Sunday night and tracking it eastward Monday and through the local area Monday night. The location of the front and amount of cloud cover Monday morning will be key in determining the potential for severe weather as well as high temps. The oppressive heat will be a thing of the past by Monday, with highs mostly back in the 80s, although the humidity will remain. Storm Prediction Center has much of the Tri State in a marginal risk, but this may even be too high. Shear looks to be high, but instability could be mainly south of the area limiting the potential for severe weather. Have maintained chance tstms in the forecast for the entire area, but this too could be overdone and am not including any enhanced wording at this time.
Will need to monitor the track of the low, with indications of 1/2 to an inch of rainfall falling on the north side of the low from the combination of frontogenesis and an approaching entrance region of an upper jet enhancing lift. Storm total rainfall amounts may range from 3/4 of an inch to 2 inches. Highest amounts are currently N and W of NYC, but a slight shift to the SE would bring the highest amounts right over the most flood prone areas (NE NJ and NYC).
The front sags back to the south on Tuesday with pcpn ending. The upper trough will linger through the middle of the week and could trigger an isolated shower Wednesday afternoon as a shortwave moves through although it will be battling subsidence from strengthening ridging. Heigheights will rise through the remainder of the forecast period, with dry weather and gradually increasing high temps.
Sub-Small Craft Advisory conditions are expected into Sunday with a prevailing W-SW flow. Gusts on the ocean waters will approach 20 kt nearshore, mainly during the afternoon hours. A cold front moves through late Sunday afternoon into early evening with the potential for scattered convection. A northerly flow of 5 to 10 kt develops in wake of the front.
Seas Monday night/Tuesday appeared to be too high based on the scenario so have knocked them down around a foot. Thus, have sub-advsy conds through the remainder of the period with a relatively weak flow
No widespread hydrologic impacts are expected through the weekend. However, some brief heavy rain will be possible with any thunderstorms.
Generally between 1-2 inches of average basin rainfall is expected Monday into Tue, with the highest amounts N and W of NYC, however this will depend on the exact track of a wave of low pressure riding along a frontal boundary. At this time, think urban and small stream flooding would be most likely, however if the axis of heaviest rainfall shifts slightly SE, the threat for flash flooding will increase
The following are records for Sunday, July 21:
Record high minimum temperatures:
NYC: 82 in 1980 LGA: 83 in 1980 JFK: 79 in 2017 EWR: 81 in 1980 ISP: 76 in 1980 BDR: 76 in 1994
Record high temperatures:
NYC: 104 in 1977 LGA: 100 in 1991 JFK: 99 in 1991 EWR: 103 in 2011 ISP: 101 in 1991 BDR: 98 in 1991
NYC NOAA Weather Radio Station KWO35 (162.55 MHz) remains off the air
NOAA New York NY Office: Watches - Warnings - Advisories
CT...Excessive Heat Warning until 8pm EDT Sunday for CTZ005>012. NY...Excessive Heat Warning until 8pm EDT Sunday for NYZ067>075- 078>081-176>179. NJ...Excessive Heat Warning until 8pm EDT Sunday for NJZ002-004- 006-103>108. MARINE...None.