NEAR TERM /THROUGH SATURDAY NIGHT/

6:49 PM EDT Update...

Most of the forecast remains valid per latest trends in obs and model guidance. Only change was to the surface wind direction forecast between roughly 3 AM and 9 AM EDT tomorrow, which is when a land breeze is expected to form over and within several miles of Lake Erie; similar to this morning. Once again, a weak synoptic MSLP gradient and significant radiational cooling over land surrounding ~77F Lake Erie are expected to permit land breeze development. Please see discussion below for further details.

Previous Discussion...

Little change expected to the weather map through Saturday night as strong Canadian high pressure at the surface remains in firm control, drifting slowly from the central Great Lakes this afternoon into the eastern Great Lakes by Saturday night. This will keep mostly clear and comfortable conditions in place as low-level northeasterly flow keeps dew points in the 50s. Another night of clear skies, light winds, and the dry airmass will lead to lows in the mid/upper 50s tonight, with some upper 40s to low 50s possible in sheltered valleys of interior NE Ohio and NW PA. Rising mid-level heights Saturday as the mid/upper trough axis over the NE CONUS slides a bit farther east allowing the ridge over the Midwest to fold east into the Great Lakes will support warmer highs in the low/mid 80s, but as mentioned, dew points will remain comfortable.
Slightly warmer Saturday night as warm air advection and high clouds increase in response to developing return flow, so expect lows to stay in the low 60s in most areas, with upper 50s in interior NW PA.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/
An omega upper level blocking pattern will stick around for much of Sunday with high pressure remaining the primary influence. This will allow for dry conditions on Sunday, although with a southerly flow becoming established, expect temperatures to be the warmest this forecast period with highs climbing into the upper 80s to low 90s.
The shift in weather patterns will begin on Sunday night as the aforementioned blocking pattern begins to break down with a trough over the central US merging with a trough over the East Coast. This trough feature will persist over the region through the end of this period, moving multiple areas of enhanced upper level energy along it and providing support for showers and thunderstorms on Monday.

The extent of showers and thunderstorms is highly dependent on the timing of the various features moving into the area and how they interact with one another. With increased moisture and WAA, afternoon instability on Monday will climb to 1000-1500 J/kg, although some models suggest even higher instability values across the western counties. Given this enhanced surface lift, opted to maintain the highest chance of PoPs from late Monday morning through Monday evening, taping to just a slight chance through the overnight hours. The biggest thing missing on the day on Monday would be any suitable upper level support. Will have to continue to monitor this setup , especially if there is a shortwave that develops and moves across the area Monday afternoon which would act to enhance the storm potential. Highs on Monday will be in the mid to upper 80s, although in areas that receive precipitation expect a bit cooler of temperatures. Overnight lows through the period will drop into the mid to upper 60s.

LONG TERM /TUESDAY THROUGH FRIDAY/
The overall synoptic pattern looks to become more favorable for widespread showers and thunderstorms by Tuesday as an upper level trough and surface low influence the area. On Tuesday, a warm front is expected to lift north of the area, increasing both moisture and temperatures behind it. Daytime instability across the area should again climb to 1500 J/kg or more, especially across western counties, providing sufficient surface support. Aloft, a vort max looks to progress east across the area providing support aloft. The storm chances will continue through the overnight hours and into Wednesday as a cold front approaches from the east. This boundary is expected to stall across the CWA through Friday, ultimately keeping the chances of showers and thunderstorms over the area for much of the week. If this boundary shifts north or south any, the location and support for showers and thunderstorms will also shift and may decrease precipitation chances. The main feature that will need to be watched synoptically speaking will be the dominant ridge over the western US and how that will influence local weather. For now, opted to include likely PoPs Tuesday and Tuesday night, but after that opted to cap it at slight chance given the uncertainty and model divergence.

High temperatures through the period will be in the mid to upper 80s with heat indices climbing into the 90s most days. Overnight lows will linger in the mid to upper 60s.

AVIATION /00Z Saturday THROUGH Wednesday/
VFR expected through 00Z/Sun as a ridge aloft builds from the Upper Midwest and the surface portion of the ridge remains anchored over/near the eastern Great Lakes, including northern OH and NW PA. Our regional surface winds are expected to be variable in direction around 5 to 10 knots. However, a land breeze is expected to form over and within several miles of Lake Erie between ~07Z and ~13Z/Sat. In addition, a lake breeze is expected to form over and within several miles of the lake between ~15Z/Sat and ~00Z/Sun. KCLE and KERI will be impacted by these land and lake breezes.

Outlook...Periodic and isolated to scattered showers and thunderstorms with non-VFR are possible Sunday night through Wednesday.

MARINE
High pressure over the eastern US will keep marine conditions pleasant through the weekend. On Saturday, a northeast flow may locally become gustier across the central basin with winds 10-15 knots and waves 1-3 feet, but still not expecting any headlines at this time. This aforementioned high will drift off the East Coast on Sunday, allowing for a south-southwest flow of 5-10 knots to become established across Lake Erie through Tuesday night. Late Tuesday, a cold front will begin to slide southeast across the lake before settling across northern Ohio and a stalled boundary for much of this week. This will maintain variable winds at 5-10 knots. In addition, chances of showers and thunderstorms throughout the week starting on Monday may result in locally higher winds and waves.

CLE WATCHES/WARNINGS/ADVISORIES
OH...None.
PA...None.
NY...None.
MARINE...None.