Not to diminish the value of UV protection, but can you cite a source for the claim "Towering cumulus (developing T-storm) clouds can actually magnify UV radiation"? It sounds incredible. Thanks.

Guys-
so, just to clarify- is Saturday going to be uncomfortably muggy, or just a little more muggy than today?

After a rough week at work, I have a lot of sitting on the deck (beer in hand) time planned for Saturday, and I'd hate for the humidity to cramp that...

I'm just STUNNED that we may have a t-storm.

Any idea on the timing of the "rainfree windows" on Sunday? Could one fall in the 3-5 timeframe when the DC United game will be taking place?

These past few days have reminded me a lot of (the best possible) summer weather in northern England. One thing I always found so annoying though was that you'd get brilliant sunshine from like 4 am - 10 am, and then it would cloud up for the rest of the day. Can the CW team explain the weather pattern where the "early bird gets the worm" as far as sunshine is concerned?

jbroon: Tomorrow will definitely be more humid today and moderately muggy... but not quite oppressive.

sick of rainy united game days: We can't pin down the timing of the rain on Sunday at this point although I will say odds are greatest during the late afternoon and evening, which unfortunately coincides with the DC United game.

Max: When there is a cold air aloft (at cloud level), and the sun warms the surface in the morning and afternoon, it causes the air to rise. When warm air rises into cooler air, it condenses and forms clouds during peak afternoon heating. Due to a dip in the jet stream, we've had cold air aloft the past several days, creating the unstable airmass that has lended itself to cloud development and isolated t'storms each afternoon.

Roy-- Here is an article from American Scientist which describes how clouds, in some cases, can enhance surface UV: Sunshine on a Cloudy Day

I'm in an outdoors wedding near Hagerstown on Saturday. Is the chance for rain/storms any different up there for Saturday afternoon?

Laura: I would say comparably low chances (30%)

This is my favorite weather website but I do have one complaint. I still don't think the capital weather gang has nailed the "At a Glance" pictures which depict the upcoming forecast. Although saturday is going to be nice with a chance of late day thunderstorms the "At a Glance" picture shows darks clouds, a rain drop, and a lightning bolt. I know enough about weather to know what it means but to the casual weather observer which probably makes up 90% of the people usuing this page it could be confusing. Aside from that I still love this page.

Eric -- Thanks for the feedback. I hear you on the icon issue and agree they could be misleading on their own. However, they're intended to complement our own forecast which provides the detail you describe -- so we hope people will read our detailed forecasts rather than solely relying on the icons. Also, the actual icon that displays is not determined by us, but by the National Weather Service, which we get through an automated feed.

Eric -- Appreciate the feedback. The timing of your comment is incredible. I literally was just talking the past couple days with Jamie, our webmaster, about a couple tweaks to our At-a-Glance icons that would go toward addressing your comment. As it turns out, the Saturday icon actually pretty much matches what the NWS is forecasting for DC on Saturday (mostly cloudy, chance of t'storms), whereas we are going partly cloudy in Camden's forecast. But you are right that there are times the icons we're showing are a bit more gloom and doom than the intended NWS forecast (although less so than the icons NWS uses on their own website). We'll be making a few tweaks over the coming days, so keep watching and let us know if you see any improvement in the icon forecast depiction.

Dan, why use the NWS feed at all? We're looking for your forecast and perhaps you should pick the icons that best represent your forecast ... (?)

My dance this evening at the Elks Lodge looks okay. (8 PM--midnight)

Columbia Pike Blues Festival tomorrow PM: chance of an isolated thunderstorm.

The big weather issue this weekend involves the projected all-day thunderstorm risk Sunday. Wonder what's going on as we have no threat of organized tropical activity anywhere other than possibly the West Pacific off Japan. Could we be subject to some rain action moving in from the Midwest?

Yesterday we had the usual dinnertime shower which has begun to be a regular feature of this pattern.

Andy-- It's simple: We don't have the time/resources to manually update that several times a day and we'd rather focus our efforts on the written commentary/features.

Yep ... some day maybe we'll do our own At a Glance. But in the meantime, we think the NWS forecast serves as a nice snapshot for those in a hurry, while we pour our effort into the more detailed forecasts that appear in the blog posts (and which you can always jump to immediately using the "Go to CWG's Full Forecast" link at the bottom of the At-a-Glance box).

I have planned a Sat camping trip on the Maryland AT with some buddies. We've going to make the "go/no-go" decision tomorrow morning. Our concern is late afternoon / early evening thunderstorm and sustained rain. Any advice from the gang?

Randy: I don't know if I'd cancel a whole trip due to the threat of scattered/isolated afternoon t'storms. I don't think this is going to be a sustained rain event -- either weekend days.

Thanks Jason.