Marine Weather and Tide Forecast for Liverpool, NY

KEY MESSAGES
1) Increasing clouds are expected tonight into Tuesday morning, along with a few light rain showers for the Wyoming Valley.

2) Dry, partly sunny and seasonable weather is expected Tuesday afternoon through at least Thursday.

3) There remains a good deal of uncertainty and spread in the development and track of a coastal low Friday into the weekend. If the low does track further west, some periods of rain will be possible along with steady north winds up to 15 mph.

DISCUSSION
KEY MESSAGE 1...

It's a complex cloud cover forecast this evening, tonight and into Tuesday. There are strato-cumulus clouds developing in the lower levels of the atmosphere streaming in from the northeast over the area. These should start to wane toward sunset. At the same time mid level clouds are trying to push in from the southwest, but are being deflected by the high pressure to the north. The latest blend of CAMs and other global guidance still suggests mostly cloudy to overcast conditions over the area most of tonight. Toward daybreak break early Tuesday morning, the clouds should clear across the northern half to third of Central NY. Strato cumulus clouds then likely redevelop as some modest daytime heating takes place across Central NY. Meanwhile NE PA, and especially the Wyoming Valley area will see thicker stratus clouds overnight and into Tuesday, along with some periods of light rain at times. Rainfall amounts continue to decrease, now expected 0.10 inches or lower only along the I-80 corridor in Luzerne County...elsewhere measurable rain is not expected. Temperatures will be cool tonight, dropping into the 40s for most locations (low 50s Wyoming Valley).

KEY MESSAGE 2...

There remains high confidence in dry, partly sunny and seasonably mild weather Tuesday afternoon through Thursday across the region. A strong surface high remains anchored to our north and east over southern Quebec and an upper level ridge moves over the area by Wednesday (out ahead of a cut off 500mb low over the Central Great Lakes/Ohio Valley). This setup keeps a northeasterly flow of dry and cool air advecting into the forecast area. By later Thursday an upper level low phases together with northern stream energy to develop a 500mb low over Virginia, but again our area remains dry.
Temperatures will be in the 60s for highs each day, with lows in the upper 30s to 40s each night. If skies clear enough overnight there certainly could be patchy fog and even patchy frost, especially by Wednesday night, but only moderate confidence on this occurring.

KEY MESSAGE 3...

Model guidance continues to struggle with the complex weather pattern setting up Friday into the weekend. As mentioned above some upper level energy will dive south across New England Thursday and merge with the 500mb low drifting east from the Ohio Valley into the Mid-Atlantic. 12z deterministic guidance such as the GFS and ECMWF have now shifted further south and east with the coastal low track.
Considering all the uncertainty with this system, taking an ensemble approach was best to account for difference in the different deterministic model guidance. As the low potentially wraps up and strengthens along the northern Mid-Atlantic coast it could still send some periods of rain back into our area from the east. The official forecast maintains a slight chance to low end chance for showers Friday into Saturday, mainly along and east of I-81. Trends in the latest guidance will continue to be monitored closely in the coming days as we attempt to resolve this storms track and potential impacts here locally. At this time, the possible outcomes range from mostly sunny and dry conditions Friday/Saturday...to cooler and cloudy with periods of rain. North-northwest winds will also be breezy and gusty, 8-15 mph with gusts up to 20-25 mph in this timeframe.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

Mainly VFR conditions are expected this evening. Some showers will be possible at AVP overnight, not anticipating restrictions at this time, at least not until after 12Z. Guidance is also hinting fog at ELM early tomorrow morning though confidence is low as conditions may be too dry for fog to develop. If fog does develop, then IFR/LIFR restrictions are possible. Winds are somewhat variable this evening with speeds up to 10 kts. Winds will shift the east tomorrow with speeds around 5 kts.

Outlook...

Tuesday Night Through Friday...Mainly VFR; potential for patch fog and IFR restrictions in early morning hours.

Friday Night through Saturday...Low chance for showers.

BGM WATCHES/WARNINGS/ADVISORIES
PA...None.
NY...None.