Friday, February 16, 2007

Near-Record Cold Slow to Ease


Clear, windy, cold. Temperatures were just a little less frigid and the winds slightly less biting today in the Washington metro area. By mid afternoon, readings had reached the 30s in many places, although the only report above freezing was from Fredericksburg. Highs were 30° at National, 28° at Dulles, 27° at BWI. Below average temperatures will continue through the holiday weekend with a chance for some light snow or flurries courtesy of a fairly energetic "clipper" storm system moving southeastward from the Northern Plains.

Tonight and Tomorrow

Clear, very cold, then increasing clouds. Under clear skies and diminishing winds, lows tonight will again be well below average: upper teens in the city, low teens to near 10° in 'burbville. Clouds will increase in the afternoon tomorrow, with some light snow or flurries possible (40% chance) late in the day or at night, especially west of the Blue Ridge. Highs will be 34-38°.

For the outlook through the rest of the weekend and beyond with Larson's Long-Range, scroll down to Josh's post below.

Close But No Cigar

One of the cardinal rules of least-regret forecasting is, "Don't forecast a record." Last night's low at Dulles seemed to have all the right ingredients:
  • A relatively short period of record (43 years).
  • An existing record which is the second highest of any day in February.
  • An Arctic air mass
  • Clear skies
  • Diminishing winds (although apparently not quite enough)
  • Low humidity
  • A solid ice pack
The result was a near miss: a low of 12.7°, just above the old record of 11° in 1987.

Cool Tool

DC's new mayor Fenty is reported to operate a whole armful of Blackberries, and his administration has implemented a "cool tool" to track snow removal in the city. The interactive map displays the status of every block in the District in terms of plowing and salting operations. (Link from WaPo columnist Marc Fisher's blog.)

Mediarology: Denial Ain't Just a River

Can't get enough climate change denialism or Gore bashing from squawk radio or the Drudge Report? Check out what some current and former Ohio weathercasters had to say at a recent panel discussion. In a sure sign that reports of the death of irony are greatly exaggerated, attached to the bottom of the Cleveland Plain Dealer article is the report that the Swiss scientist who discovered that phosphorus from laundry detergent was killing the Great Lakes by choking them with algae died last month. Didn't he know that there was just a natural algae cycle and banning phosphorus would kill the detergent industry and destroy the American way of life?

Thursday, February 15, 2007

Frigid February Fifteenth


Variable clouds, windy, cold. The sun angle is almost halfway between the winter solstice low and the spring equinox, but that natural cycle was heavily outweighed today in the Washington metro area by some frigid Arctic air reinforced on strong northwesterly breezes. Highs barely reached the upper 20s: National 27°, Dulles and BWI 24° Combined with the chilly overnight lows, the month's double-digit deficit from average was extended further.

Although the record low of 5° at National is not in jeopardy tomorrow morning, the record of 11° last reached in 1987 at Dulles is the second highest daily minimum for February there and could be seriously threatened. The weekend will not be quite as cold, but still chilly.

Tonight and Tomorrow

Clear, very cold. Clear skies, low humidity, and diminishing winds should allow temperatures to plunge tonight to the mid teens in the city and upper single digits to near 10° in the coldest 'burbvilles. Tomorrow will be sunny and not quite as cold, highs 27-30°.

For the outlook through the weekend and beyond with Larson's Long-Range, scroll down to Josh's post below. chart based on Eq. 2.9 in Stull, Meteorology for Scientists and Engineers, photo © Kevin Ambrose

Wednesday, February 14, 2007

Cold Comfort: Could Have Been Worse


Variable clouds, windy, cold. We now return to our regular programming. The "Praying Mantis Storm of 2007" (see image to the right of complex low pressure system at 7am this morning) could have done much worse damage to the Washington metro area if its massive quantities of sleet had been freezing rain. Nevertheless, over 100,000 customers lost power, particularly in Prince George's and Anne Arundel Counties.

After early highs in the mid 30s (National 35°, Dulles 34°, BWI 36°), , temperatures have dropped again this afternoon toward freezing, continuing the string of every day so far this month reaching 32° or below. (The 30-year average for February is 18.5 days, so we're well on our way to meeting the quota.) The monthly average through yesterday of 26.9°, if it continued to the end of the month, would tie this February with 1885 as the 4th coldest in Washington history.

Cold temperatures for the next several days mean that the ice will be with us for a while, and there is at least the possibility of some light snow from a clipper system this weekend.

Tonight and Tomorrow

Clearing, windy, cold. Lows tonight under clearing skies will be in the upper teens to near 20° in the city and low to mid teens in 'burbville. Wind chills could be as low as zero. Tomorrow will be mostly sunny, windy, and cold, highs in the upper 20s to about 30°.

For the outlook through the weekend and beyond with Larson's Long-Range plus the latest Snow Lover's Crystal Ball, if any, tune in tomorrow for Josh's post.

Pictured: A snow blower needs assistance from some old-fashioned technology in western Fairfax Co. yesterday. In conditions like this, PM Update Central prefers the trusty ice chopper obtained a quarter century ago at Houst Hardware. By photographer Kevin Ambrose.

Capitol Climate: The "F" Word (No, Not That One!)

In our last installment of the Capitol Hill Climate Follies, 4 scientists were testifying on the Hill about the recent IPCC climate change report. Last Friday's edition of the Chronicle of Higher Education provides a review of the session, including the purported role of dinosaur, shall we say, "flatulence".

Seasonal Outlook

Latest seasonal forecast: Click here.

Latest 3-month temperature outlook from Climate Prediction Center/NWS/NOAA.