Marine Weather and Tide Forecast for Port Ewen, NY

NEAR TERM /THROUGH TONIGHT/

Update
As of 1:30 PM EDT...Decaying MCS now tracking to the south of our region, with just a few light showers scraping portions of the I-84 corridor in the Mid Hudson Valley. We have had a few pop-up cells over the high terrain in southern VT within the last hour or so, but these showers have struggled to intensify given limited instability so far and lack of shear to help storm organization. However, we are seeing more breaks in the clouds, with mainly clear skies to our west that should move in over the next few hours, which should help to increase out instability. Previous thinking of mid-level dry air and subsidence helping to prevent CI over the next few hours still holds from the previous forecast, but additional showers/storms still remain possible this evening. Please see previous discussion below for more details on the marginal severe threat this afternoon. Otherwise, only notable adjustments with this update were to bump temps up a couple degrees for northern areas that have seen more clearing and knock them down a couple degrees for the eastern Catskills and Mid Hudson Valley where there are more clouds as well as the influence of cool outflow from the morning MCS. Previous forecast overall remains in good shape...

Previous
MCS tracking across western and central NY earlier this morning has decayed significantly, as shown by radar trends and warming cloud tops on IR satellite imagery. A few sprinkles or light showers are possible with with the remnant convection over the next hour or two across the Catskills, but overall it should remain dry through early this afternoon.

Attention then turns to the potential for additional shower and thunderstorm development this afternoon. More clearing behind this decaying MCS should allow for temperatures to warm well into the 70s to low 80s for daytime highs. Dew points in the 60s and steepening mid-level lapse rates will allow for up to 1000-1500 J/kg of SBCAPE to build this afternoon, and the outflow boundary from the decaying MCS may act as a focus for convective initiation (CI) this afternoon.

However, current GOES 16 WV imagery shows a lot of mid-level dry air behind this decaying MCS, and model forecast soundings show a slight capping inversion that may inhibit convective initiation, at least through the first half of the afternoon.
12z HRRR showed less widespread convection this afternoon compared to previous runs, which is in line with current thinking. Nevertheless, with heights falling aloft this evening there may be enough additional forcing to overcome any cap, and so we are still expecting at least scattered showers and thunderstorms very late this afternoon into early tonight.
Greatest chance appears to now be along and north of I-90.
Vertical shear isn't overly impressive at <25-30 kt so widespread/organized severe weather isn't expected, but with DCAPE values approaching 750-1000 J/kg a few storms could contain damaging winds. We still agree with the SPC marginal risk across the region. PWATs on the order of 1.25-1.45" could also lead to some locally heavy rainfall within thunderstorms, and storm motions won't be overly fast, so isolated hydro issues can't be ruled out this evening. We have made these adjustments to reflect the above thinking with this forecast update.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/
Key Message:

- Severe thunderstorms Saturday afternoon and early evening with chances for all severe weather hazards (Winds stronger than 58 mph, hail greater 1 inch, and isolated flash flooding)

Timing: Between 9 AM and 8 PM Saturday

Forecast Confidence: Moderate (40-60%) for timing, impacts, and locations to see severe thunderstorms.

Discussion:

Latest high resolution model guidance continues to support strong to severe thunderstorms to move from west to east across eastern New York and western New England beginning mid to late Saturday morning for locations north of I-90 and in the early afternoon hours Saturday everywhere else. The current nature of storms is widely scattered, but latest forecast trends are hinting as multiple lines of storms potentially developing to move west to east. Taking a deeper dive into environmental conditions, we look at energy needed at and above the surface to initiate thunderstorms which will be plenty available Saturday. Dew point temperatures in the 60s and with cooler temperatures above the surface, this will help contribute to one of the primary hazards for Saturday being damaging wind gusts greater than 58 mph. Hail size up to 1 inch also can't be ruled out Saturday with severe thunderstorms. As with any developed thunderstorm, isolated locations of flash flooding could occur due to heavy rainfall especially in low-lying, poor drainage locations.
It's important to be weather aware and prepared for severe thunderstorms Saturday such as having multiple ways to receive warnings, securing loose outdoor items, having an action plan to move indoors if you are outdoors when you hear thunder, and clearing drainage locations from debris (such as leaves).

Thunderstorms should be east of western New England during the early evening hours as a strong cold front moves through with a few lingering rain showers overnight into Sunday afternoon.
Temperatures finally become cooler into the 40s and 50s with highs on Sunday in the 50s and 60s. A low pressure system that brought the associated cold front continues to move north and east across the Northeast Sunday bring breezy and cooler conditions in store for Sunday night.

LONG TERM /MONDAY THROUGH THURSDAY/
Surface low pressure continues to depart farther to the north and east away from the region early next week as high pressure noses in from the Great Lakes. This will result in a period of drier weather.
An increased pressure gradient between the departing low and incoming high will result in a northwesterly breeze both days. A few gusts could exceed 30 mph on Monday. High temperatures will start out below normal with highs in the 50s and 60s.

Another period of unsettled weather likely returns for the mid to late week period as separate northern and southern stream upper shortwaves/closed lows attempt to phase together within the Great Lakes/Ohio Valley region. A low pressure system will initially track from the Ohio Valley into the Lower Great Lakes, later developing a secondary surface low near the mid-Atlantic coast which then tracks northeastward through the end of the week. The result will be increasing probabilities for periods of rainfall. The overall interaction between these shortwaves remain uncertain and would impact the overall track of this system and when and how much precipitation occurs. Precipitation probabilities are in the 35 to 50 percent range on Wednesday increasing to 55 to 70 percent by Thursday. High temperatures both days continue to run below normal, in the 50s and 60s.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/
Through 18z Saturday...VFR conditions are in place across all terminals this afternoon with decreasing clouds across the region. This afternoon, MVFR conditions will be possible with passing showers and some isolated non-severe thunderstorms. With differences in the guidance on just where these will develop and track, it was difficult to pin down exactly when and where these showers and storms could potentially impact terminals. So, input TEMPOs and PROB30 groups at KALB and KGFL where these are most likely this afternoon and this evening. KPOU and KPSF should remain dry, though a light shower or two crossing through their vicinity is possible. Any MVFR conditions from precipitation should improve to VFR once again tonight before some fog/low stratus is expected to develop everywhere. This will especially be possible where winds go calm and at terminals that see rain this afternoon. MVFR to IFR conditions are expected with this and IFR ceilings will continue into the end of the 18z TAF cycle even after visibilities improve tomorrow morning. Otherwise, winds will be relatively light and variable out of the south with sustained speeds ranging from about 5-10 kt.

Outlook...

Saturday Night: Moderate Operational Impact
Chance of SHRA
TSRA.
Sunday: Moderate Operational Impact. Breezy. Chance of SHRA.
Sunday Night: Low Operational Impact. Breezy. Slight Chance of SHRA.
Monday: Low Operational Impact. Breezy. NO SIG WX.
Monday Night: Low Operational Impact. Breezy. NO SIG WX.
Tuesday: No Operational Impact. NO SIG WX.
Tuesday Night: Low Operational Impact. Slight Chance of RA.
Wednesday: Moderate Operational Impact. Chance of RA.

ALY WATCHES/WARNINGS/ADVISORIES
CT...None.
NY...None.
MA...None.
VT...None.