2:00 p.m. - The focus for most of the shower and thunderstorm activity will be north of a line from Bremerton to Seattle. Instability will allow for showers and thunderstorms – some with small hail – to persist in these areas through the early evening. Elsewhere, expect partly sunny skies. With the additional cloud cover this morning (debris from showers and storms), highs will be only in the lower 80s for Seattle.
Showers in the lowlands and mountains will taper later tonight. Morning lows will be in the 50s with some clouds along with some sunshine. The start to Seafair Sunday should be very nice.
1:21 p.m. - Best chance of rain this afternoon (and thunderstorms) will be from King and Kitsap counties north as well as in the mountains.
12:36 p.m. - A few heavy showers with potential for small hail and thunder will continue to roll northeast across King County through 1:30 p.m.
12:15 p.m. - A few showers will continue with the chance of thunder through early afternoon, but the chances will diminish as the day wears on.
Noon - Thunderstorms with small hail and lightning moved through Puget Sound this morning.
The most numerous and strongest cells were between 7 and 9 a.m. and produced small hail around Kirkland, Seattle, University Place and Enumclaw.
Larger hail to the size of dimes was reported near Maple Valley.
Another thunderstorm quickly developed over downtown Seattle around 11 a.m. While this storm was small in size, it produced lightning strikes that briefly interrupted power to the KIRO 7 studios and other locations around Seattle.
On KIRO 7's Facebook page, viewers said they could hear the thunder in the Bothell-Mill Creek area, Alderwood, Port Orchard, North Bend and multiple Seattle neighborhoods.
These storms were produced by plenty of low-level moisture and warmth below cooler air aloft. This "instability" allowed thunderstorm updrafts to grow higher in the sky, up to 40,000 feet in the atmosphere.
Morning thunderstorms of this intensity are quite unusual.
Fortunately, for Seafair activities on Lake Washington, even the late-morning thunderstorm over downtown Seattle didn't interrupt the fun. KIRO 7's Deborah Horne at the pits at Seafair reported blue skies while lightning was striking toward downtown.
Later today, lowland showers and storms will end and the attention will turn to the central and north Cascades for a thunderstorm threat.
A repeat of this stormy weather is not expected for Seafair Sunday.
This is a developing story and will be updated once more information becomes available.