Heavy Rain Likely Flood Watch in Effect

**Flood Watch in effect 7PM tonight through tomorrow morning.**

Now

Cloudy, seasonable Clouds were lowering and thickening this afternoon ahead of a massive storm system centered over the upper Midwest. Moderate to heavy precipitation is indicated over southern West Virginia late this afternoon. Despite the cloud cover, temperatures were over 50° for the 3rd consecutive day, following the coldest February since 1979 and the 15th coldest since the beginning of official Washington records in 1871. February's total snowfall of 5.9" at National was above the 30-year average by 13%.

Today's high/departure from average: National 52°/+2, Dulles 51°/+1, BWI 50°/+1

Tonight and Tomorrow

Rain developing, moderate to heavy. Rain will develop over the region this evening from southwest to northeast, becoming moderate to heavy at times; scattered thunderstorms are possible. Lows will be in the upper 40s. Rain will end in the morning tomorrow with some clearing in the afternoon and highs in the upper 50s.

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

Blogosphere Climate

The ClimatePolicy blog was launched today by the American Meteorological Society's Policy Program. It is intended to "discuss a wide range of topics that span scientific understanding, impact assessment, policy analysis, and the value judgments that shape people’s policy preferences" related to climate change.

Mediarology

The Weather Channel's foray into prime-time infotainment continues with the debut of a new series, "Epic Conditions". The show, which features extreme outdoor sports, premieres Sunday at 9pm with an episode on extreme skiing at Steamboat. Media Daily reported last week that the new program will be replacing "Storm Stories" in the weekday schedule this fall.

MediaWeek reported Monday that new research shows significantly higher ad recall rates for the Weather Channel than USA Network or HGTV.

Frigid February Finally Fading

Now

Sunny, seasonable True to form, this February is finishing with a below-average day, although it's only by 1°. The seasonable temperatures felt even more springlike this afternoon with the strong sun and light winds. Highs were 51° at National, 52° at Dulles, 50° at BWI.

Meanwhile, a storm system which once again dumped on Denver with an additional 3-7" of snow will be heading toward the upper Great Lakes in the next couple of days, bringing possibly heavy rain to the Mid Atlantic area and an icy mix to interior southern New York and New England.

Tonight and Tomorrow

Increasing clouds, chance of rain in afternoon.
Clouds will begin to increase tonight with lows in the mid 30s downtown to near 30° in 'burbville. Tomorrow will be mostly cloudy with a 40% chance of rain by evening and highs 48-52°

For the outlook Friday through the weekend, scroll down to Dan's post below. Also included in Dan's post is a post-mortem of Sunday's storm.

Climate Corner

An international panel of scientists sponsored by the United Nations Foundation and the scientific research honor society Sigma Xi released a report yesterday "outlining the best measures for mitigating and adapting to global warming." The executive summary, full report, and links to news coverage are available on the UNF web site.

(N)ice Art

Our link yesterday to Walter's snow sculpture was picked up by our friends at the USA Today weather blog.

Nibbling Away at the Cold

Now

Mostly sunny, seasonable. After the persistent cold most of the rest of this month, today's near-average temperatures seem mild by comparison, as Sunday's snow continues to fade away, perhaps helped in part by the legendary Snow Mice. At mid afternoon, most reporting locations in the metro region were within a couple of degrees of 50°. Highs were 52° at National, 51° at Dulles and BWI.

Dry conditions will continue for another day or so while a new storm system organizes in the central Rockies and heads toward the Great Lakes on a similar track as the last one, promising an icy event for parts of the East Coast. This time, however, both of the main U.S. models have the ice zone a couple of hundred miles further north. This time they mean it. Honestly. Stay tuned.

Photo of snow sculpture from CapitalWeather.com visitor Walter. See Flickr for some more amazing creations.

Tonight and Tomorrow

Partly cloudy, seasonable. Lows tonight under partly cloudy skies will be from the low and mid 30s in town to the upper 20s in the cooler 'burbvilles. Tomorrow will be similar to today, but with a bit more sun, and highs 48-52°.

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

Revenue Removal

An article in today's WaPo Metro section implies that local transportation departments could use some help from the Snow Mice. Despite the aggregate snow total being only about 50% of "normal", seemingly chronically underfunded snow removal budgets have already been exceeded, in some cases prior to Sunday's event.

Snow Turns to Slush

Now

Melting. Temperatures at or above freezing during much of yesterday's main event, through the overnight hours, and then emerging sunshine today have made quick work of melting the snow accumulation in the Washington metro area. Here at PM Update Central outside the Beltway in MoCo, where 5½" fell, patches of ground are already showing, especially on south-facing lawns. Highs were 40° at National, 42° at Dulles, 43° at BWI, after lows of 32° at all 3 locations.

The leftover moisture in the area, along with some upper-level energy moving nearby to the south, could produce some fog, as well as light rain showers or flurries tonight through tomorrow morning.

Tonight and Tomorrow

Some fog, chance of showers or flurries, milder. Lows tonight under variable cloudiness should range from the mid 30s downtown to the upper 20s in 'burbville. Some fog is likely to develop, and there is a 30% chance of rain showers or snow flurries through tomorrow morning. Clouds will decrease during the day tomorrow with highs in the upper 40s to 50°.

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

V-Day Storm Rated Cat 3

The Valentine's Day snow/ice storm has been given a preliminary rating of Category 3 ("major") on the new Northeast Snowfall Impact Scale (NESIS). The storm was ranked as the "14th biggest impact out of a sample of 34 of the largest winter storms since 1950, and it was one of the largest winter storms to strike interior sections of the Northeast (as opposed to coastal areas) since 1950. The storm was one of the top three interior Northeast snowstorms observed since 1940."

Windy Cold At Bat; Wintry Mix On Deck

*Winter Storm Watch in Effect Late Saturday Night Through Sunday Night*

Now

Windy, cold. We're in the late innings, but winter isn't ready to put away the bat just yet. Winds peaking as high as 55 mph overnight have made it feel a lot colder than the near 40° temperatures this afternoon in the Washington metro area, especially after the relatively balmy experience of 3 consecutive days above average (and above freezing). Highs were 41° at National, 39° at Dulles, and 38° at BWI.

A low pressure area just now becoming organized in the central Rockies will deepen and move northeastward toward the Great Lakes, bringing with it the threat of some wintry precipitation in the Mid Atlantic region Sunday.

Tonight and Tomorrow

Clear, less windy, cold. Under clear skies and diminishing winds, lows tonight should be from the low 20s downtown to the mid and upper teens in 'burbland. Tomorrow will be mostly sunny and continued cold, less windy than today with highs 42-45°

For the outlook through the rest of the weekend, including Sunday's potential wintry mix, scroll down to Camden's post below.

Tropical Topics

Winter may be still batting, but tropical season is just over 90 days away. Here at PM Update, we're getting in the mood by starting to read Ivor van Heerden's "The Storm", a scientist's on-the-scene report of the Katrina experience. From the tone of the introduction, it appears that he will be pulling no punches in his analysis of what went on.

Meanwhile, yesterday the National Hurricane Center published their annual post mortem analysis of forecast accuracy for last year's storm season. The good news: Atlantic track forecast accuracy set new records in the range from 12-72 hr., beat each individual dynamical model, and only slightly trailed the consensus models. The bad news: Intensity forecasting continues to be a formidable problem. Intensity accuracy was close to the average of the last 5 years, but skill levels (improvement over average conditions, or climatology and persistence) were "down sharply."

Chart of hurricane track forecast accuracy in nautical miles at 24, 48, 72, 96, and 120 hr., years 1990-2006, from NHC

Spring Pops Up; Winter Attempting to Rally

*Wind Advisory in Effect Through 10am Friday*

Now

Windy, turning colder. Some light showers (0.01") and even the sound of thunder in some places ushered in winds gusting over 40 mph at times as a cold front south of an energetic clipper system moved briskly eastward through the Washington metro area today. Temperatures, however, again exceeded expectations, popping up to the nearly spring-like upper 50s before they began to drop around mid afternoon. Highs were 59° at National, 56° at Dulles, 55° at BWI. To the south, Charlottesville and Richmond were both in the low 60s.

Winter will be attempting to stage a comeback in the next couple of days as below-average temperatures return along with a marginal possibility of some more winter-like precipitation on Sunday.

Surface weather map at 1pm today from HPC/NCEP/NWS

Tonight and Tomorrow

Clearing, windy, colder. Lows tonight under clearing skies will be in the upper 20s to near 30°. Tomorrow will be mostly sunny and breezy with highs only in the low 40s.

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

Winter Thunder

The 30-year climatological average is 1 February thunderstorm every 5 years in Washington, but thunder has now been observed in 2 consecutive Februarys and in 3 out of the last 5. The previous occurrence to last year was in 2003.

Mediaorology: Channel 4 Sweeps V-Day Storm Coverage

Yesterday's WaTi business section had an article, "TV news makes hay out of snow" about the local news ratings during the Valentine's Day storm and the implications of the weather coverage for the all-important February "sweeps" period. The corrected rankings in today's dcrtv blog show WRC-4 in first place for all 3 time slots (6am, 5pm, 11pm), followed by WJLA-7 at 6am and 5pm; WTTG-5 was second at 11pm. WUSA-9 was last at 6am and 11pm and 3rd at 5pm. WRC's score was at least 50% above the last-place station in each set of ratings; it was over 4 times the last-place WUSA-9 at 11pm.

CapitalWeather.com chart from Washington Times data via dcrtv.com, photo © Kevin Ambrose

Winter Strikes Out

Now

Sunny, seasonably mild. There are still a few more innings to be played, but winter has struck out in the Washington metro area, at least for now. Despite a northerly breeze, mild Pacific air and strong sunshine pushed temperatures beyond the optimistic end of the forecast range by mid afternoon, reaching the mid 50s. Highs were 56° at National, 52° at Dulles and BWI. After 7 consecutive days with 1" or more of snow/ice on the ground, melting has reduced the depth to 0. The melting was helped by the 0.25" of showers which fell last night. Freezing temperatures throughout the country have retreated to near the Canadian border.

Temperature chart at 3pm today from Unisys

Tonight and Tomorrow

Partly cloudy, mild. Lows tonight will be in the mid to upper 30s under partly cloudy skies, with some low 30s in the cooler 'burblands. Tomorrow will be variably cloudy with highs near 50°, but becoming breezy and colder late in the day. There is a 30% chance of showers in the late afternoon or evening.

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

Climate Corner

Today's WaPo reports that the Maryland House of Delegates has approved with a wide bipartisan 122-16 margin a bill to regulate auto CO₂ emissions. Following inaction at the federal level, 10 other states have already enacted regulations based on those established in California. Senate approval is expected, and Gov. O'Malley has promised to sign the bill, which requires new vehicles sold or registered in the state to have an average fuel economy of 43 miles per gallon by model year 2011.