Here is how much precipitation it would take to break the drought as of Saturday.

Update 2:22pm EDT: Severe thunderstorm warning for winds in excess of 60 mph now in effect for DC and Virginia suburbs. Original posting: NWS radar at 1:45pm EDT. These "waves" you see in the lines line of thunderstorms west and southwest of Washington, DC are known to meteorologists as Line Echo Wave Patterns (LEWPs). When you see the greatest reflectivity on the leading edge, they are especially likely to cause high -- or damaging -- winds. (Relatively) Weak tornadoes (all tornadoes are dangerous!) can occur at the crest of each wave. Major flight delays at Atlanta, Baltimore, Charlotte, Newark, JFK, LaGuardia, Philadelphia, Orlando, and San Francisco.

In addition to the tornado watch, we now have major weather-related delays at San Francisco, Atlanta, Baltimore, Newark, JFK, LaGuardia and Philadelphia.  If you are stuck in all of this or planning to fly this afternoon in or near these areas, here is my Airline Crisis Survival Guide .

Here we go. These include Baltimore, D.C., Richmond and Raleigh. A number of severe thunderstorm warnings are already out. Major weather-related delays now reported at Baltimore, Newark, LaGuardia and San Francisco. These will grow in number and worsen as the day progresses (with the possible exception of SFO). Note: I will not be live-blogging today's storms. More info from AccuWeather .

Here is today's tornado potential map. Generally, 5% represents a significant threat. And, here is the threat area for thunderstorm-generated winds of 60 mph or more. Generally 15% is considered a significant threat in this category. Go ahead, while you are thinking about it, and bring in lawn furniture, trampolines, and other objects that can be blown about. Putting the car in the garage is a good idea. Plan to keep up on the weather in your area if you live in the threat zone. Already, there are major flight delays at Baltimore and LaGuardia. As the day progresses, I expect the delays to spread to more airports and become longer in duration.

The above tornado watch represents the beginning of (yet another) severe weather threat for the Middle Atlantic and Northeast regions. The hatched area, especially, has the risk of damaging thunderstorm winds and tornadoes tomorrow. Pay attention to the weather if you live in these regions! Probability of tornado, wind more than 60 mph or large hail within 25 miles of a point. Hatched area is region where stronger tornadoes and winds of more than 75 mph may occur. Forecast by the NWS Storm Prediction Center

An illuminating interview with Anthony Watts that will be aired on PBS's News Hour  this evening (6pm CDT in Wichita). Here is a video of the interview: There is a transcript here . I agree almost completely with Anthony's view of global warming.