Forecast: Weekend showers a worry?
Summery Friday in the 80s; weekend cools to 70s
* There is hail & then there is hail | Fog of the Cape Cod wind farm *
* Outside now? Radar, temps & more: Weather Wall | Nats-Orioles *
More sun than clouds is nice. But hot enough to sweat, even with fairly low humidity.Today: Partly sunny. Mid-to-upper 80s. | Tonight: Partly cloudy. Upper 50s to low 60s. | Tomorrow: Partly sunny to mostly cloudy. 30% chance of mainly p.m. showers & storms. Mid-to-upper 70s. | Sunday: Mostly cloudy. 40% chance of showers & storms. Low-to-mid 70s. | A Look Ahead | Get Express Forecast by E-mail
FORECAST IN DETAIL
Today's 80s may be too hot for some, especially on the trip home for those observing Bike to Work Day. Increased weekend clouds help bring highs down to the 70s as humidity ticks upward. The extra moisture in the air combined with lower pressure could spark showers and thunderstorms at times over the weekend, though as of now chances are below 50%.
Today (Friday): Great end to our week!... if you're a warm-weather fan. Partly sunny skies help temperatures reach the upper 70s to near 80 around lunchtime. Even with some clouds at times, highs should make the mid-or-upper 80s. Wear that sunscreen if out in the direct midday sun. Confidence: High
Tonight: Wow! Our second fantastic evening in a row, with temperatures dropping into the 70s. Lows cool to the upper 50s to low 60s under partly cloudy skies. Confidence: Medium-High
Keep reading for the forecast into next week...
Tomorrow (Saturday): The morning hours might squeeze out some sun, but steadily the clouds should build and probably hold highs to the mid-to-upper 70s. As of now, we have about a 30% chance of showers & thunderstorms, mostly focused on the afternoon hours. Winds around 10 mph from the southeast bring in a bit more humidity. Confidence: Low-Medium
Tomorrow Night: Any isolated thunderstorms should die down by late evening. But we'll stay with a 30-40% chance of showers through the night. Mostly cloudy skies keep overnight lows mild. Downtown may only get down to the low 60s. Upper 50s to near 60 outside the Beltway. A bit of humidity in the air could prove a tad uncomfortable. Confidence: Medium
Sunday: The forecast remains somewhat tricky on Sunday with partly to mostly cloudy skies. Shower and thunderstorm chances go up to around 40%. Highs in the low-to-mid 70s should be nice enough if you don't mind the moderate humidity. Just don't stray too far from shelter in case any sudden thundershowers or heavy showers pop above you. Confidence: Low-Medium
Mostly cloudy Sunday night with a 20-30% chance of a shower or two. Upper 50s to low 60s should do it for lows. Confidence: Low-Medium
Assuming high pressure builds in strong enough to exert its authority (not a sure bet), then Monday & Tuesday should feature decreasing precipitation chances and increasing sunshine with highs in the mid-70s to low 80s. Confidence: Low-Medium
By
Camden Walker
| May 21, 2010; 9:00 AM ET
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Posted by: SBrun | May 21, 2010 6:37 AM | Report abuse
@SBrun
There's a 30-40% chance of showers Sunday morning. That's about as much detail as we can provide at this point. Check back tomorrow and Sunday morning for more info.
Posted by: CapitalWeatherGang | May 21, 2010 10:10 AM | Report abuse
and we've got a patio party on sunday afternoon/evening. what exectly makes the forecast "tricky"?
Posted by: rhingo | May 21, 2010 10:11 AM | Report abuse
@rhingo
This is a weak, poorly defined system passing through. Trying to nail down the timing and location of showers and storms that might form at this point is difficult. This is often the case with late spring and summer showers and storms -- i.e. convective activity. It's like heating up a pot of hot water and trying to predict exactly where and when one bubble will reach the surface.
Posted by: CapitalWeatherGang | May 21, 2010 10:23 AM | Report abuse
We're planning an outdoor event from 2-4 Saturday afternoon... appreciate CWG's thoughts on whether we should cancel some of the outdoor festivities. In other words, are the rain chances for tomorrow the summer late-afternoon type storms, or more a risk of a steady (though scattered) rain event all afternoon? Thanks & a nice weekend to all.
Posted by: JenDC | May 21, 2010 10:37 AM | Report abuse
@JenDC
Would not cancel outdoor festivities - but have a plan to move indoors if necessary. Shower/storm activity Saturday afternoon probably scattered.
Posted by: CapitalWeatherGang | May 21, 2010 10:50 AM | Report abuse
Looks like the webcam stopped working and a good time.
Posted by: Ian-CapitalWeatherGang | May 21, 2010 11:05 AM | Report abuse
Ugh, let me see if I can replace the graphic. How annoying! I wanted to capture the nice day today, with the sunshine... ah well
Posted by: Camden-CapitalWeatherGang | May 21, 2010 11:24 AM | Report abuse
Hey CWG -- If a watched pot never boils, then does that mean it won't rain this weekend? ;-) Thanks for your info and honesty.
Posted by: erbele | May 21, 2010 11:57 AM | Report abuse
According to the weather maps there's almost no surface low, trough or frontal boundary by Sunday, just high pressure and a southeasterly flow...is it possible the rain could fizzle out by then?
Posted by: Bombo47jea | May 21, 2010 12:39 PM | Report abuse
Thanks, CWG, for the explanation.
R
Posted by: rhingo | May 21, 2010 12:51 PM | Report abuse
erbele - I like your analogy, but don't think it applies too much to the atmosphere this weekend. I think we could have fun discussing Schrödinger's Cat and other metaphysical items ;) but really I should report more on the physics of the atmosphere this weekend being unstable enough that showers/storms could pop up almost anywhere (thank Chaos Theory for that aspect) haha :-) Let me know if I should put in hyperlinks to articles for you?
Bombo47jea - with a southerly flow, near a "dirty" high pressure system .. I still think chances are decent for showers & storms to pop. You are right they won't be due to lifting ahead of much, if any, of a boundary, but these "airmass storms" will still act like popcorn over parts of the region. (I am doubting it would be any sort of line of storms with much coverage area)
Posted by: Camden-CapitalWeatherGang | May 21, 2010 1:26 PM | Report abuse
Camden -- For the links, sure. I am finding that learning about physics is a lot more interesting at age 50 then it was at age 15! (I just read about Schrödinger's Cat, I already know about Chaos Theory!)
Posted by: erbele | May 21, 2010 2:02 PM | Report abuse
haha, agreed erbele. Much more fun outside of official schooling. We can delve into it on the internet nowadays too. At our own pace. etc. etc.
Glad to see you found what I was alluding to :-)
Posted by: Camden-CapitalWeatherGang | May 21, 2010 2:17 PM | Report abuse
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We're hoping to go strawberry picking this weekend - what are our chances of a rainout if we go early (10ish) on Sunday morning? Thanks!