Marine Weather and Tide Forecast for Oswego, NY

KEY MESSAGES
1) Patchy fog this morning, mainly over and east of Lake Ontario.

2) Summer-like heat Monday and Tuesday with the chance for a few afternoon showers and thunderstorms inland from the lakes, especially Tuesday.

3) A strong cold front will bring showers and thunderstorms midweek, followed by mainly dry, but much cooler conditions for the later half of the week.

DISCUSSION
KEY MESSAGE 1...Patchy fog this morning, mainly over and east of Lake Ontario.

Warm, moist air advecting over the cold waters of Lake Ontario has resulted in an expansive marine layer over the northern half of Lake Ontario, and continues to advect inland across much of the eastern Lake Ontario region this morning. Visibility has improved at mid morning in many areas, but some patchy fog will still be found close to the lake and along the Saint Lawrence River through midday before improving this afternoon. Most of the fog over Lake Erie and the western Southern Tier has lifted into a stratus deck.

KEY MESSAGE 2...Summer-like heat Monday and Tuesday with the chance for a few afternoon showers and thunderstorms inland from the lakes, especially Tuesday.

Mid and upper level ridging will amplify over the eastern third of the CONUS and western Atlantic early this week, setting up a deep southwesterly flow right into our region. A couple of low pressure systems will cut northeast through the upper Great Lakes in between the eastern ridge and western trough first part of this week forcing a strong push of mid-summer like air into the lower Great Lakes and Northeast on their eastern flank. This will help boost temperatures well into the 80s across much of western and northcentral NY Monday and Tuesday, with a run at 90F not out of the question for some of our traditionally warmest locations. The warmest day will likely be Monday with the mid and upper level ridge axis cresting over our region, with upper level heights then falling a bit Tuesday as the ridge axis moves east of the area. NBM max temperature output continues to be too warm, thus in coordination with surrounding offices as has been done over the past several days, daytime highs were lowered a few to several degrees both days. The potential for reaching heat headline criteria continues to be low, however this is the first time this season our area will experience true, summer- like weather. Expect temperatures along and close to the lakeshores to be cooler owed to the still chilly lake water temperatures.

Building instability both afternoons will bring the possibility for a few showers and thunderstorms to develop along and inland of any lake breeze boundaries. This will be especially true on Tuesday afternoon as a strong cold front approaches from the west.

KEY MESSAGE 3...A strong cold front will bring showers and thunderstorms midweek, followed by mainly dry, but much cooler conditions for the later half of the week.

A strong cold front is progged to cross the area later Tuesday night and Wednesday morning, bringing a period of showers and thunderstorms to western and northcentral NY. A large area of high pressure will build into our region in the wake of the front, bringing a mainly dry, but much cooler airmass back in across the area. Coolest day will be Thursday, with many locations not getting out of the 50s. Expect a slow rebound in temperatures into the holiday weekend with 60s and some low 70s.

AVIATION /12Z SUNDAY THROUGH THURSDAY/
Lingering low level moisture will bring the potential for flight restrictions this morning in some areas.

Warm, moist air advecting over the cold waters of Lake Ontario has resulted in an expansive marine layer over the northern half of Lake Ontario, and continues to advect inland across much of the eastern Lake Ontario region this morning. Visibility has improved at mid morning in many areas, but some patchy fog and IFR will still be found close to the lake and along the Saint Lawrence River through midday before improving this afternoon. IFR CIGS will continue east of Lake Ontario through midday before improving this afternoon. Most of the fog over Lake Erie and the western Southern Tier has lifted into a stratus deck, with areas of IFR/MVFR CIGS across the Southern Tier through midday before improving this afternoon.

Strong mid May diurnal heating will help erode most of the fog and low stratus over land by midday, with a return to mainly VFR conditions by late morning/early afternoon. Marine fog and stratus may persist over the lakes for much of the day.

Otherwise, mainly dry weather will prevail today through tonight.
The one possible exception is the potential for a few isolated showers and thunderstorms later this afternoon and evening across the western Southern Tier.

Outlook...

Monday...Mainly VFR with a low chance of showers and thunderstorms, mainly in the afternoon and early evening.

Tuesday..Mainly VFR. A chance of a few showers and thunderstorms later in the afternoon.

Tuesday night through Wednesday...Areas of MVFR with showers and thunderstorms likely, ending later Wednesday.

Thursday...VFR.

MARINE
A weak pressure gradient will be in place today and tonight on both lakes providing light winds and little to no wave action.

Pressure gradient steadily tightens some Monday through Monday night, bringing gradually strengthening SW breezes on both lakes with light to at times moderate chop, before near SCA conditions will be possible by Tuesday afternoon with fresh southwesterlies across western Lake Ontario ahead of an approaching cold front.

BUF WATCHES/WARNINGS/ADVISORIES
NY...None.
MARINE...None.