NEAR TERM /THROUGH SATURDAY/
High pressure will continue to drift slowly east tonight to the Lower Great Lakes by Saturday, bringing continued dry and mainly clear weather. The clear skies and light winds will allow for good radiational cooling conditions again tonight, with lows dropping back into the 50s. Expect some river valley fog across the Southern Tier late tonight through early Saturday morning.

Saturday, a few diurnal cumulus may develop again with daytime heating inland from the lakes. Otherwise, plenty of sunshine once again. Ongoing airmass modification will add on a few more degrees to temperatures, with highs in the low to mid 80s for lower elevations on upper 70s on the hills.

SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/
An omega block will drift east across the Ohio Valley and eastern Great Lakes Sunday, with surface high pressure beneath drifting from NY/PA and New England Sunday into southern Quebec by Monday. High pressure surface and aloft will continue to support an extended period of dry weather for the second half of the weekend into at least the first half of Monday. A mid level trough and associated weak surface trough will move into the western Great Lakes and Ohio Valley later Monday. A gradual increase in large scale forcing, moisture, and instability will bring a low chance of a late day shower or thunderstorm to far Western NY, but the better rain chances will remain west of our region through Monday.

Temperatures will continue their day to day warming trend with building heights and ongoing warm advection. Highs Sunday and Monday will be in the upper 80s to near 90, with mid 80s for higher terrain. Surface dewpoints only slowly rise through the period, with no appreciable heat index above and beyond the actual air temperature through Monday.

LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
Very warm and humid conditions are expected to continue through this period. Temperatures above normal, with dewpoints in the mid 60s to mid 70s will keep days humid and nights muggy. Heat index values will near 90F, and lower 90s by Friday. Showers and thunderstorms will be possible each day through this period.

A closed Atlantic low will start this period off the Atlantic coastline, drifting north/northwestward. Exact track and timing of this closed low is still with uncertainty...which will have ramifications on the timing of the trough/ridge progression the remainder of the week. As such timing showers and thunderstorms will be difficult. Weak, mild flow aloft does not bring an increase potential for severe storms as of yet, though the PWAT values 1.75"+ within this weak flow could yield drenching thunderstorms with potential hydro concerns.

AVIATION /21Z FRIDAY THROUGH WEDNESDAY/
Clear skies and VFR will prevail in most areas tonight. Areas of river valley fog will develop across the Southern Tier with local IFR. The chance of fog at KJHW is low (but non-zero) with a better chance of fog in the surrounding valleys.

Saturday, Southern Tier river valley fog will burn off by mid morning, leaving VFR to prevail as high pressure remains over the eastern Great Lakes.

Outlook...

Sunday through Monday...Mainly VFR. Valley fog with local IFR possible across the Southern Tier each overnight/early morning.
Tuesday...VFR/MVFR with a chance of showers and thunderstorms.
Wednesday...VFR/MVFR with showers and thunderstorms likely.

MARINE
Surface high pressure will drift east tonight to the lower Great Lakes by Saturday, then to New England Sunday before weakening over southern Quebec Monday. The resulting light winds and negligible wave action will generally support very nice conditions for recreational boating this weekend...although very light winds on Saturday may be less than ideal for those sailing.

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