DC: Dewpoints Climbing

** Heat Advisory in effect noon to 8pm Tuesday **

Now

Hazy, hot, humid. Yesterday's showers varied widely in amount across the region, from zero in parts of Northern Virginia to over an inch in some eastern locations. (The green areas through much of Prince George's County range from 0.5" to as high as 1.5", while the blues through much of the District and Montgomery County are less than 0.5", and most of Fairfax County is less than 0.1".)

The additional moisture, however, has helped lift dewpoints into the sultry low 70s, a level which pushes the heat index up about 7 or 8 degrees from the temperatures in the low 90s. Both Ft. Belvoir and Manassas were sporting heat indices of 100° by 2pm, and Ft. Belvoir was the hot spot at 4pm with an index of 103°. By mid afternoon, however, radar showed only a few isolated showers, mostly southward along I-95.

Hot temperatures and uncomfortable humidity are likely to continue through the middle of the week.

Chart of 24-hr. precipitation through 8am this morning from NWS Southern Region.

Tonight and Tomorrow

Hot, humid, scattered thunderstorms possible. There is still a slight chance of an isolated thunderstorm through this evening; otherwise, it will be a warm and sticky night with lows barely getting into the upper 70s downtown and the lower 70s in the 'burbs. Tomorrow will be continued hot and humid with highs 95-99° and heat indices approaching 105°. There is only a slight chance of an afternoon or evening thunderstorm.

For the outlook through the rest of the week, scroll on down to Jason's post below.

Tropical Topics

The tropical wave which tracked westward through the Caribbean late last week has pushed onward into Central America without developing.

As the Proenza affair at the National Hurricane Center continues to unfold, the House Committee on Science and Technology announced today that the chairmen of 2 subcommittees have sent a letter to NOAA Administrator Lautenbacher requesting that Proenza be returned as Director of the NWS Southern Region if he is permanently removed from his post at the NHC. According to the letter, NOAA had planned to assign Proenza as training chief of the Office of Climate, Water and Weather Services, a "drastic demotion", before the NHC assessment team had even been formed. An article in Friday's Miami Herald reviews Proenza's campaign to get his job back.

The paper by Holland and Webster on "Heightened Tropical Cyclone Activity in the North Atlantic" which PM Update posted on last Monday has been referenced in the Science Notebook of today's WaPo, but without the crucial caveat that this issue is far from settled because of the limitations of the available data.