Marine Weather and Tide Forecast for Staatsburg, NY

DISCUSSION
Key Messages:

- Dangerous heat and humidity return Wednesday with heat index values ranging from 95 to 100 throughout portions of the Hudson and Mohawk River Valleys where a Heat Advisory is now in effect.

- Additional Heat Advisories possible for Thursday with heat index values looking to reach the mid/upper 90s.

- An unsettled pattern will lead to multiple rounds of showers and possible thunderstorms beginning late Wednesday afternoon through early next week.

Discussion:

High pressure dominating the surface beneath mid- to upper-level ridging aloft will ensure dry conditions through early Wednesday afternoon. The amplification of said ridge, however, will see 850 mb temperatures increase to about +17C to +19C, translating to surface air temperatures reaching the low 80s to low 90s. And while forecast soundings show a fair amount of mid-level dry air present tomorrow, a steeper subsidence inversion and the advection of warm, moist air through deep southerly flow will pose a detriment to the amount of mixing that will take place.
And, unlike today, predominantly southerly winds will not favor downsloping and subsequent drying that could limit the rise of dewpoints. Therefore, with heat index values looking to reach 95 to 100 throughout portions of the Hudson and Mohawk River Valleys, a Heat Advisory is in effect from noon to 8 PM tomorrow.

Late tomorrow afternoon, tranquility comes to an end as the surface high slides north and east while a stationary boundary currently sitting just off to our south lifts north and eastward as a very diffuse warm front/dewpoint boundary. Meanwhile, the ridge aloft is forced to also shift eastward as a shortwave disturbance sinks south and east from the eastern Great Lakes. Scattered showers and thunderstorms look to develop late tomorrow afternoon/early tomorrow evening as cyclonic vorticity advection increases in response to the upper impulse and low- level convergence increases as a result of the weak boundary. At this time, the two forcing mechanisms do not look to intersect, leading to more widely scattered showers tomorrow night. Latest CAMs have also adopted this solution, so confidence has therefore increased in this element of the forecast. It is possible, with some elevated instability, that some embedded rumbles of thunder could occur, however, the severe threat is slim to none with very little shear and very marginal lapse rates.

Southwesterly flow Thursday will force the continuation of dangerously hot and humid conditions, though to a lesser extent than Wednesday. This will be especially true if any showers and/or thunderstorms from Wednesday night linger farther into the morning Thursday. However, at present, we expect heat indices to reach the mid to upper 90s especially throughout portions of the Hudson River Valley, so additional Heat Advisories may be necessary. Outside of the heat, additional rounds of showers and thunderstorms are expected throughout the day Thursday as yet another upper-level shortwave rotates through the region atop a surface frontal system. Shortly ahead of the cold front associated with the surface low traversing southern Quebec, a pre-frontal trough will track through the region, generating an initial batch of showers and thunderstorms late Thursday morning. Along and ahead of the incoming cold front and attendant shortwave aloft, a secondary round of showers and thunderstorms comes Thursday afternoon into Thursday evening, with the possibility of some of these being stronger to potentially severe in magnitude. A bit more shear than we have seen recently and high DCAPE values indicate the potential for strong to locally damaging wind gusts being the primary hazard.
However, with this being a very conditional threat dependent on the extent of convection Wednesday night and Thursday morning, confidence is not yet high in this element of the forecast.
However, we will continue to monitor this closely going forward.

The loss of daytime heating Thursday should put an end to the threat for thunderstorms with mere lingering showers into Thursday night and Friday morning as the aforementioned cold front and upper-level shortwave track through the region. This being a true cold front, Friday will begin the cooling trend heading into the weekend, putting an end to the oppressive heat and humidity. Highs will therefore be in the 70s to low 80s.
Saturday will then be one of the best days, if not the best weather day, of the 7 day period with surface high pressure and ridging aloft building in to once again reinforce dry conditions regionwide. Favored conditions will, unfortunately, be short- lived, however, as unsettled conditions return and bring back the chance for showers and possible thunderstorms Sunday and possibly into Monday. However, differences in the medium to long range guidance make for a low-confidence forecast especially for Monday. Highs will remain in the 70s and 80s, though, so the continuation of non-oppressive heat is fairly confident.

AVIATION /17Z TUESDAY THROUGH SATURDAY/
Through 18Z Wednesday, VFR conditions prevail through at least 02Z/Wed. Then, clear skies within the lingering muggy air mass will likely allow patchy fog to develop leading to intermittent MVFR and IFR Vsbys at all terminals toward 05-07Z/Wed at KGFL/KPSF before more frequent intervals of IFR/LIFR Vsbys/Cigs develop after 08Z/Wed. Intermittent periods of MVFR vis may also develop at KALB and KPOU. IFR/VIS fog then lifts into a low stratus deck by 12-14 UTC before giving way to VFR flying conditions at all sites.

Outlook...

Wednesday Night: Moderate Operational Impact
Chance of SHRA
TSRA.
Thursday: High Operational Impact
Definite SHRA
TSRA.
Thursday Night: Low Operational Impact
Slight Chance of SHRA
TSRA.
Friday: No Operational Impact. NO SIG WX.
Friday Night: No Operational Impact. NO SIG WX.
Saturday: No Operational Impact. NO SIG WX.
Saturday Night: Moderate Operational Impact
Chance of SHRA
TSRA.
Sunday: Moderate Operational Impact
Chance of SHRA
TSRA.

ALY WATCHES/WARNINGS/ADVISORIES
CT...None.
NY...Air Quality Alert until midnight EDT tonight for NYZ032-033- 038-042-083.
Heat Advisory from noon to 8 PM EDT Wednesday for NYZ038-040- 041-043-049-050-052-053-059-060-064>066-083-084.
MA...None.
VT...None.