Cold Rain, Then Cold Wind Cold Theory in the Cold

Now

Showers, cold. Despite a breeze with a south of east component, heavy clouds and light showers are keeping temperatures from reaching 50° in most of the Washington metro area this afternoon. Precipitation amounts through 5pm have been only 0.1" at National and 0.05" (all of which fell in the last hour) at Dulles.

Rainfall should be heavier overnight, however, as a developing low pressure area in the mid Mississippi and lower Ohio valleys gets cranked up on its way to the eastern Great Lakes by tomorrow. Following the passage of this very deep low, strong winds should bring another shot of cold air in for the rest of the weekend. The National Weather Service has issued a High Wind Watch for Saturday evening through Sunday morning for the potential of sustained winds at least 40 mph or gusts at least 58 mph throughout the local blogging area.

Pictured: One model's prediction of a very strong (980 mb) low centered over southern Canada Saturday evening. The closely-spaced isobars indicate strong winds over the Mid Atlantic area; from NCEP/NWS

Tonight and Tomorrow

Rain, then windy and colder. Rain will become heavier tonight, with temperatures steady in the upper 40s to near 50°. The rain will end as showers by mid day tomorrow. Southerly winds ahead of a strong cold front could push temperatures into the low 60s around the middle of the day, but strong northwesterly winds following the frontal passage will bring falling temperatures through the rest of the afternoon and into tomorrow night.

For the outlook through the rest of the weekend, scroll down to Camden's post below.

Climate Corner

The RealClimate blog today revisits the issue of global cooling claims made in the 70s. Newsweek has just done a re-evaluation of their 1975 article titled, "A cooling world." They conclude in the cold light of today that huge improvements in data collection and modeling technology have made "any forecasts from 1975 as inoperative as the predictions being made around the same time about the inevitable triumph of communism." The real lesson here is: Don't get your science from the SCMSM (so-called mainstream media).

Chilly Still on the Menu

A strong ridge of high pressure extending from northern Hudson Bay across eastern North America to Cuba continued pumping cold air into the Mid Atlantic region on Wednesday. A northwesterly breeze again gusting over 30 mph at times kept temperatures well below seasonal averages in the Washington metro area. High temperatures were 55° at National and Dulles, 54° at BWI.

Despite diminishing winds, temperatures will remain well below average today as a low pressure area becoming organized in the central Rockies and incorporating leftover moisture from what was eastern Pacific Huricane Paul brings the threat of rain late Friday into part of the weekend.

Surface weather map at 11pm last night from HPC/NCEP/NWS

Today and Tonight

Continued cold, less windy. Under mostly sunny skies, today's highs will be in the mid 50s. Overnight, clouds will increase toward morning with lows near 40° in the city, low to mid 30s in the cooler 'burbs.

For the outlook through the weekend, scroll down to Dan's post below.

Fun with Numbers

Larson's Long-Range is off today, but we can take the opportunity to look at the connection, if any, between fall and winter temperatures. With both September and October running cooler than average, the question arises whether or not this indicates anything about the upcoming winter. As Matt has already noted, the relationship is quite complex.

The chart shows the September and October (SO) average temperature on the x-axis, and the following December, January, and February (DJF) average on the y-axis. The data points include the 135 years of Washington observations through last year. The solid regression line represents the best fit to the data, with the equation of the line shown in the upper left. The upward slope of the line shows that there is a positive relationship, but the correlation is very weak. The value 0.09 for R² means that only 9% of the variability in winter average temperatures is explained by the September-October average. Note that out of the 5 coolest SO averages, there was one year with the coolest DJF average, but there was also one with the second warmest DJF. (For more on regression analysis, see the discussion of the December-January relationship posted last year.)

For more Washington DC data, see:
Washington DC Weather Records

CapitalWeather.com chart from NWS data, photo © Kevin Ambrose

A Winter's Day

Correction: The reference to the daily high below (which did hold at 51°) should have said that it was within one degree of the record low maximum for the date. The fact checkers at PM Update have been suitably admonished to stay off the fried Coke.

Now

Cold, windy. It's "a winter's day in a deep and dark . . ." October? Returning from a weekend visit to the pig races and fried everything (including Coke) at the N.C. State Fair, PM Update finds that someone left the freezer door open.

Assisted by a northwesterly wind gusting over 30 mph, temperatures in the Nation's Capital region are struggling to reach the low 50s this afternoon, and the wind makes it feel much colder. The high hourly reading at National of 51° at 2pm, if it holds for the day (It's been back to 50° through 5pm), would be the average high for Dec. 2-4, and it misses the record low minimum for the date in 77 years of records by only 1°. The last time the daily high was below 55° was March 26.

CapitalWeather.com chart from NWS data, photo © Kevin Ambrose

Tonight and Tomorrow

Continued cold, breezy. Winds should die down somewhat tonight, but not enough to push lows below the mid to upper 30s in most places. Tomorrow will be partly cloudy and breezy, but not as windy as today, with highs around 54°.

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

Climate Corner: "Would You Like Information with Your Data and Fries?"

If you've ever done any searching in an unfamiliar subject area in the virtual haystack known as the web, you know it's often very hard to separate the golden from the garbage. RealClimate.org, the climate site run by climate scientists, announced today that they are participating in a new service by Google Co-op which allows searches to be performed using only sites which have been selected to meet some level of quality. So, if you'd rather get your climate change information from scientists instead of paid political propagandists, fiction writers, the oil industry, or Homer Simpson, try out their new search facility.

Slow Burn

Now

Cloudy, foggy. Pervasive low clouds and fog, with even some mist and drizzle thrown in, have been mightily resistant to burning off today in the Washington metro area, resulting in a slow burn by meteorologists over busted temperature forecasts. Temperatures have struggled to reach even the mid and upper 60s in most places, although by 4pm, the robo-observer at Fredericksburg was reporting clear skies (below 12,000 feet, anyway) and 73°.

A cold front and developing low pressure area approaching from the Ohio Valley will bring increasing chances of showers late tonight and part of tomorrow before it moves off to bring heavy rain to northern New England.

Tonight and Tomorrow

Showers likely, then cooler. Lows tonight under overcast skies will be in the upper 50s. The chance of showers is 70% by morning. Showers are likely tomorrow morning, possibly a few thunderstorms, with decreasing clouds in the afternoon and early highs in the mid 60s, but turning cooler later.

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

Energy Watch: Being Green

If you're interested in reducing the amount of energy you burn and possibly saving some green as well, the recent NYT article, "The Energy Diet", is number 16 on the paper's list of most popular emailed articles in the last 30 days. The author, Andrew Postman, appeared on today's WAMU-FM Kojo Nnamdi show. Real Audio and Windoze Media streaming audio are available on the station's web site.

(In the interest of "fair and balanced" coverage, Instapundit responds from the right.)

Image from New York Times

Frost is Off the Pumpkin

Now

Sunny, warm. Yesterday's chilly rain has been replaced by warm October sun in the Washington metro area. Temperatures at mid afternoon were generally in the mid to upper 70s, with exurb Fredericksburg reporting 81° for about the last 3 hours. Summery dewpoints in the low to mid 60s were adding a hint of mugginess as well. Another warm day is on tap for tomorrow before the next storm system developing in the Ohio Valley helps bring in some Gulf moisture for rain or showers tomorrow night and into Friday.

Tonight and Tomorrow

Continued Warm. Skies will be mainly clear tonight, but without any drying, lows are unlikely to be much below 60° in most places. Some fog is probable in low-lying areas. Tomorrow will again be mostly sunny and warm with highs in the mid 70s, but with cloudiness increasing late in the day.

For the outlook through the rest of the week and the weekend, scroll down to Dan's post below.

The Future Ain't What It Used to Be

Issue 14.09 (September) of Wired Magazine has an article, "Storm Center", reviewing the tradeoffs between form and function in the design of the new NOAA Satellite Operations Facility in the venerable Suitland Federal Center. In replacing the old mission control in an "asbestos-riddled, flood-prone, former World War II-era hospital", the techno-geeks said, "Save money! Just build us a box." The architect, however, took a broader view, given that the cost of his futuristic design was only about 8 hours of Iraq War. (Before you start the political flames, that's his quote, not mine!) The building is scheduled to begin operations this fall.

Image from Wired Magazine

Soggy to Sunny

Now

Showers, cool. Heavy rain at times today has given way to lighter showers and drizzle this afternoon in most of the Washington metro area. Radar shows the heavier showers retreating eastward of I-95 near Washington and I-83 north of Baltimore.

Of the 3 major regional airports, National has the least amount so far with just over ½" by late afternoon, bringing the monthly total of around 3" close to the long-term average for the whole month of October. BWI has the most with almost an inch. Accumulations were somewhat higher to the west at Frederick and Hagerstown, which are now both over 1".

With the heavier clouds moving eastward, some breaks in the overcast are apparent west of the Blue Ridge. Temperatures are generally within a degree or two of 60°.

CapitalWeather.com chart from NWS data, photo © Kevin Ambrose

Tonight and Tomorrow

Gradual clearing, becoming warmer. A few showers and some drizzle and fog will linger through this evening. Lows tonight will be in the mid to upper 50s with clouds beginning to decrease toward morning. Tomorrow will be mainly sunny, especially in the afternoon, and warmer, highs in the mid 70s.

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

Mediarology: Aviation and El Niño

The deadliest aviation accident in history occurred in 1977 when two fully loaded jumbo jets collided, killing 583 passengers and crew. The crash was weather-related, but it happened on the ground. The PBS science series NOVA investigates the circumstances tonight (8pm on WETA 26 and WMPT 22).

NPR's "Living on Earth" interviewed Dr. Kevin Trenberth, Head of the Climate Analysis Section at the National Center for Atmospheric Research, on El Niño last Friday. A transcript and podcast are available on the show's website. The program is broadcast on WETA 90.9 FM, Tuesdays from 10pm to 11pm.

Crisp Turns to Damp

Now

Increasing clouds, cool. A thickening high overcast moving literally over the top of a slowly retreating high pressure area (1024 mb/30.26" at 4pm at National) has kept the string of below-average temperatures going in the Washington metro area. By 4pm, readings were generally in the low 60s with a light southerly breeze.

A non-tropical system with tropical moisture which brought up to 10 inches of rain, flooding, severe thunderstorms, and 2 deaths to the Houston area will work its way northeastward tomorrow, bringing some rain to the Mid Atlantic region.

CapitalWeather.com chart from NWS data, photo © Kevin Ambrose

Tonight and Tomorrow

Increasing chance of rain. Lows tonight under cloudy skies will be close to the long-term average for a change, near 50°. The chance of rain will increase to 50% by morning. Highs tomorrow will be only around 59° with rain becoming steadier and heavier by noon. While the models are keeping the heaviest precipitation west of the mountains, the latest output this afternoon brings an area of up to 1" of rain into at least the western portion of the DC region by tomorrow afternoon.

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

Climate Corner

The discussion has continued into this afternoon over Andrew's Sunday Undercast, "Climate Change: Denying Denial."

Yesterday's Climate Code on The Weather Channel included more evidence that the climate change issue is NOT political, despite the attempts of some to make it so. It included an interview with the president of the Chicago Climate Exchange, which provides a market for trading greenhouse gas emissions. It also covered the environmental characteristics of the new office tower being built in New York by that noted left-wing radical anti-capitalist organization, Bank of America. If you missed the Sunday broadcast, it's scheduled to be repeated this Saturday.