ridge is expected to affect the Lake Erie region and Upper OH Valley on Sunday through Friday, June 12th. Aloft, the mean ridge axis should drift from near the western Great Lakes and Lower OH Valley toward the eastern seaboard of the United States. At the surface, the primary high pressure center should wobble SE`ward from northern ON and the Upper Great Lakes to Atlantic waters east of Bermuda. This projected weather pattern evolution at the surface and aloft will allow net low-level WAA to impact our CWA. In addition, a low-level moisture tap to the southern Gulf Stream and/or Gulf should develop this Monday through Friday and allow humidity to increase noticeably, especially on Tuesday onward. Moderating temperatures should include late afternoon highs in the mid 70`s to mid 80`s on Sunday followed by late afternoon highs in the mid 80`s to mid 90`s this Thursday and Friday. Note: sufficient daytime heating of surface air over land surrounding ~59F Lake Erie and a favorably-weak synoptic MSLP gradient should allow a lake breeze to develop and affect locations within several miles of the entire lake during the late morning through early evening hours of this Sunday and Monday, respectively. The coolest high temperatures are expected within the lake breeze. Fair weather is expected on Sunday through Sunday night due, in part to stabilizing subsidence accompanying the ridge. Subtle shortwave troughs should ripple generally eastward through the ridge aloft this Monday through Friday. Low-level convergence/moist ascent along attendant surface trough axes may trigger isolated to scattered showers and thunderstorms, especially each afternoon through early evening, as a moistening boundary layer destabilizes via daytime heating. Latest trends in NWP model guidance do not depict a strong signal for any storms to become severe. However, the combination of appreciable boundary layer instability and moderate deep-layer bulk shear may support a few strong to severe storms during the afternoon and early evening hours of Wednesday and Thursday. && .AVIATION /00Z Saturday THROUGH Wednesday/...

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Several rounds of showers are likely throughout the TAF period. The first round of showers will likely clip NW OH early in the TAF period with more one or two more rounds of showers likely across most of the area later tonight into early Saturday morning. While thunderstorms can`t be completely ruled out during the overnight/early morning showers, confidence is too low to introduce any thunder chances with this update. There will probably be a break in precipitation mid to late morning into the afternoon before a broken line of showers and thunderstorms develops somewhere across NE OH/NW PA Saturday afternoon and moves south into Saturday evening. There`s still quite a bit of uncertainty in the placement/timing of thunderstorm initiation due to potential for early-day clouds and precipitation, but currently thinking that the best chance of thunderstorms will be south of a line from KTOL to KCLE to KERI between about 21Z and 00Z. The forecast will likely be refined as confidence increases in subsequent updates. Any showers/storms throughout the TAF period could produce non- VFR conditions in lower ceilings and especially reduced visibilities in moderate to locally heavy rainfall. The severe weather risk is low through Saturday morning, although any afternoon/evening thunderstorms could produce strong/erratic wind gusts and hail. Winds will be out of the southwest at 8 to 14 knots with gusts to 20 to 25 knots through the majority of the TAF period. Winds will become a bit more westerly Saturday afternoon before diminishing a bit towards the end of the forecast period. Outlook...Non-VFR possible in patchy fog early Sunday morning. Periods of non-VFR likely in occasional showers and thunderstorms Monday night through Wednesday.

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&& .MARINE... Southwest winds on Lake Erie will increase to 15-25 knots tonight ahead of a cold front, with the stronger winds focused towards the east end of the lake on Saturday. This will lead to elevated waves in the open waters of 3-6 feet. The cold front pushes south of Lake Erie late Saturday afternoon/evening with winds decreasing quickly. Thunderstorms will also be possible tonight and Saturday with a few strong storms possible on the lake Saturday afternoon. High pressure builds in behind the front for Sunday and Monday with a light onshore flow Sunday and 15 knots or less on Monday. Southerly flow resumes on Tuesday. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ DISCUSSION...Jaszka AVIATION...15 MARINE...10