Thursday, February 8, 2007

Double Digit Departure Developing


Clear, windy, cold. Winter continues its icy grip on the Washington metro area. With every day so far this February below average and today becoming the 4th consecutive day having a double digit departure from average, the month as a whole is now pushing into negative double digits. The next winter storm event is likely to take shape in the first half of next week, but the timing, track, and intensity are still subject to adjustment in the coming days.

Tonight and Tomorrow

Clear, cold. Lows tonight under clear skies will be in the mid to upper teens in the city and low teens to near 10° in 'burbland. Tomorrow will be much like today, but with a little less wind and highs about 30-32°.

For the outlook through the weekend and beyond, including the Snow Lover's Crystal Ball which has the scoop on next week's potential winter storm, scroll on down to Josh's post below.

Capitol Climate

U.S. contributors to the recent IPCC climate change report, Drs. Susan Solomon (NOAA), Kevin Trenberth (NCAR), Richard Alley (Penn State), and Gerald Meehl (NCAR), were busy on Capitol Hill today, testifying this morning to the House Science and Technology Committee and this afternoon to Senate Environment and Public Works. Copies of the prepared testimony and webcasts are available through the respective committee web sites, and at least the House hearing was covered on CSPAN, so it should be available in reruns during the next several days.

The portion of the House hearing Q&A which I saw indicates that many politicians on both sides of the aisle are increasingly understanding the science and are willing to discuss it from a non-ideological point of view. From the context of the conversation, it appears that several committee members have scientific backgrounds, although the specifics were not clear. Obviously, there are significant differences regarding the policy implications, but most of the discussion, with the notable exception of the final rebuttal, was refreshingly free of the anti-scientific propaganda still echoing around various web noise sites and squawk radio, as well as, sadly, the editorial page of the Wall Street Journal, which is inexplicably attached to what is otherwise a world-class newspaper.

Wednesday, February 7, 2007

Snow? You Call This Snow?


Clear, cold. Well, that was as exciting as the real thing: 1-2" of very fluffy powder (egged on by 463 exuberant comments from visitors) from a fast-moving "clipper system" across the Washington metro region last night has been followed by sunny, breezy, and cold conditions this afternoon and a rapidly disappearing "snow pack". Highs have been generally in the upper 20s: 29° at National, 28° at Dulles, 27° at BWI, for another double-digit negative departure from average. Josh will undoubtedly have more to say on this later, but the cold temperatures are likely to continue well into next week, with some early indications of a more substantial (perhaps even "superstantial") winter event early in the week. (NWS, going out on a bit of a limb at the 6-day range, is calling for 50% chance on Tuesday in their latest update.)

Tonight and Tomorrow

Clear, cold. Winds will diminish tonight with clear skies and lows near 15° in the city and 10° in 'burbsylvania. Tomorrow will be sunny, windy, and cold, with highs near freezing.

For the outlook through the rest of the week and the Snow Lover's Crystal Ball, scroll on down to Dan's post below.

Snow Daze

Closing decisions by area school systems are an easy target, and hindsight is always 20/20, but as a long-time taxpayer of the great state of Maryland and Montgomery County in particular, PM Update is seriously wondering if someone can explain what happened today. (Yes, teachers, we feel your pain. The young Update ran off to sea rather than spend more than 1 semester trying to indoctrinate some of the parents of today's little darlings in the intricacies of non-base-10 number systems.)

Card-carrying members as we are of the reality-based community, we took the PM Update mobile unit out to gather some real-time data on the situation. Traveling the bone-dry pavements of North Bethesda and Kensington, we were surprised to observe some conditions that some of you more sheltered city-dwellers might not easily apprehend. At the major intersections, there was considerable danger of skidding . . . from the massive quantities of sand on the roadway. Another hazard which might not be intuitively obvious to the non-professional was the sand trucks themselves hurtling across the double yellow line as they raced back to the garage at the end of their grueling 3 or 4 hour shifts. Finally, not to be overlooked is the subtle snow-day menace posed by the SUVs full of high school students careening down Rockville Pike to meet their friends to hang out at White Flint Mall.

It's not as if the scope of this "storm" was incorrectly forecast, either here or by any other outlet I observed. In comments to the previous post, I noted that the water equivalent of this powder ranged up to a high of 0.07" at Dulles. Assuming that the snow depth was a full 2" (probably rounded up; I had to really stretch to find as much as 7/8" even on the north side at Update Central in MoCo), that means almost 97% of the stuff was air, which is exactly what most of it turned into by lunch time, especially on those 50% of all ground surfaces which face south. If there was any question at all about conditions, and it's extremely hard to believe there was one, why wouldn't a 2-hour delay have been sufficient?

Pictured: Class, this is what real snow looks like, observed last weekend by's Matt and Ian, along with a group of DC-area snow-starved lake-effect storm chasers at Pulaski, NY. Some of the "chase team" appeared with Mike Seidel on the Weather Channel Monday night. Some video by Randy Legette of is on YouTube.

Monday, February 5, 2007

How Cold Is It?
Chance of Snow Tomorrow Night


Windy, very cold. "[I]t's so cold outside, the politicians have their hands in their own pockets." (Va. Rep. Tom Davis at last week's House Government Oversight Committee hearing on climate science censorship.) After an official low of 14°, the Washington area's latest Arctic blast limited temperatures to near 20° in many places this afternoon, although the southern fringes of the region saw readings as high as the mid and upper 20s. Winds gusting as high as 30 mph at times made the temperatures even more uncomfortable and dewpoints in the negative teens added to the drying effect.

Temperature chart at 4pm today from Unisys

Tonight and Tomorrow

Very cold. Winds will diminish tonight. Along with clear skies and very low dewpoints, lows will drop to near 10° in town to the low single digits in the 'burbs. Tomorrow will be mostly sunny and not quite as cold, but with increasing clouds late in the day and highs in the upper 20s.

Tomorrow Night

Chance of Snow. A weak "clipper" system sliding in from the northwest could bring some light snow or flurries to the area before moving off the coast. With the extreme dryness of the current airmass and the weakness of the system, any accumulations are likely to be minimal. There's about a 50-50 chance we'll see more than half an inch in the metro area, but most likely under 2 inches.

For the outlook through the rest of the week and the Snow Lover's Crystal Ball, scroll on down to Jason's post below.

Cold Comfort

The proof of the pudding will be tonight, but some of the more breathless media claims of "coldest in a decade" may have been a bit premature. Today's low of 14° is the lowest since February 19 last year. If we reach single digits tonight, as seems likely, it will be the first time since . . . well, actually since 8° 3 years ago on Jan. 10. If tomorrow's high is at least 25°, the low would have to be 4° or below to equal that 2004 day's average.

Looked at another way, there's a long way to go in the next 3 weeks or so in order to "cancel out" the above-average record so far this winter. To balance the +30° departure from average on Jan. 6 this year, tomorrow would have to see a low of -1° and a high of 15°. Overall, the rest of February would have to average 12.8° below normal for the winter to be average. In order to do this, high temperatures would have to average no warmer than about the mid 30s for the next 23 days.

Climate Corner

After sleeping on it over the weekend, the WaPo has an editorial today on the latest IPCC global warming report.

In the blogosphere, Stu Ostro of the Weather Channel "fired" back Friday against the anti-scientific global warming skeptics. The links include several useful references to the scientifc literature. In another post early this afternoon, he responds to an earlier comment by clarifying and confirming what we've been saying here all along, that Dr. Heidi Cullen's so-called demand for "decertification" of AMS Seal of Approval holders was completely invented by the ideological noise machine and amplified by certain parties for their own purposes. Thank you, Weather Channel, for standing up for the science against ideological ignorance.

Dr. Cullen has a joint blog entry with 2 other climate scientists today, "There is More Heat. Let There be Light", discussing the IPCC report.

Seasonal Outlook

Latest seasonal forecast: Click here.

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