Thursday, August 23, 2007

Saving Private August


Cloudy, a little warmer, humid. Despite the "Partly sunny, High 85" on the front page of your dead-tree WaPo this morning, it's another cloudy and cool, but sticky, afternoon in the Washington metro area. (Wonder how that happened; those lazy drones at the National Weather Service and their freedom-hating lackeys at said "upper 70s". Oh yeah, here it is in small print on the back page of the Metro section: "SOURCES: AccuWeather, Inc. . . ." I would have sworn I read somewhere (scroll down) that socialized meteorology was Bad for America.)

Although the wind still has an easterly component, it's been more out of the south than recently, and some thinning of the low overcast has allowed temperatures to reach the mid and upper 70s by mid afternoon. At 3:00, you'd have had to go as far south as Richmond to see a temperature of 80°. Dewpoints are even more muggy than yesterday, in the sticky upper 60s to 70°. If you opened your windows, you're probably going to need air conditioning to get the humidity down. Radar is showing an impressive area of storms and an associated warning box northeast of Pittsburgh, but it's dry east of the mountains.

As we've been promising and Jason explains in his post below, more August-like temperatures are on the way and should be here for the weekend.

Tonight and Tomorrow

Decreasing clouds, humid, warmer. Without much of an incentive (maybe they should be privatized) to leave town just yet, the clouds will persist tonight, and the high dewpoints should contribute to mist and fog in some places with lows in the upper 60s to near 70°. Although the clouds will last into the morning, indications are good that some sun in the afternoon tomorrow will allow temperatures to finally get back to the mid and upper 80s, perhaps even 90° for a high.

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

Tropical Topics

Dean was declared dead, and the last advisory was issued at 11pm last night. No new development is expected in the Atlantic for the next couple of days.

Political Science

Bob King, who covers hurricanes for the Palm Beach Post in his Eye on the Storm blog, does an excellent job of deconstructing the Faux News war on the National Hurricane Center in his post yesterday. He includes a link to some unofficial, but absolutely devastating, data on the issue of AccuWeather vs. Hurricane Center accuracy on Katrina (and Rita, as well). In 5 cases (6 for the feds), the AccuWeather 5-day position error for Katrina was more than double that of the Hurricane Center.

Wednesday, August 22, 2007

The Dog Nose Days of August


Cloudy, very cool, humid. Like a dog's nose, the metro area's weather remains cool and damp. The record low maximum of 69° for today was threatened with breakage only through early afternoon, but the more optimistic temperature predictions by most forecasters were clearly busted. Some sun penetrated the continuing low clouds, but even by mid afternoon temperatures were struggling to pass 70° at most locations in the region. Despite the high humidity, however, radar has been clear in all directions.

A gradual decrease in cloudiness should lead to a warming trend, but there is wide disagreement among models on the pace of that warming.

Tonight and Tomorrow

Decreasing clouds, humid, gradual warming. Skies will be mostly cloudy overnight with lows in the mid to upper 60s. Clouds will decrease gradually tomorrow, and the actual amount of sun will strongly determine the degree of warming; model predictions range all the way from 77° to 89°, about as wide a range as you're likely to see around here. Humidity will remain high, but there is only a 20% chance of showers throughout the period.

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

Tropical Topics

Hurricane Dean made a second landfall on the Mexican Gulf coast about 40 miles south of Tuxpan around 12:50 Eastern time today. The storm had strengthened back to a Category 2 (max winds 100 mph). It was already weakening over land this afternoon; by the 5pm advisory it was down to tropical storm strength. It is expected to quickly dissipate as a heavy rain storm over the mountains of central Mexico.

Elsewhere in the tropics, no development is expected in the Atlantic Basin for the next 48 hours.

The Phillyweather blog had some interesting comments yesterday about media coverage of the hurricane. Also in the blogosphere, The Weather Channel has some typically insightful comments by Dr. Greg Forbes on the persistence of Erin's remnants and by Stu Ostro on Dean's minimum pressure.

Local Event

Next Monday, the 27th, the Center for American Progress is presenting a panel discussion, "Forecast: Storm Warnings". This forum "will discuss the impact of global warming on hurricane severity and frequency. In addition, there will be a discussion of necessary federal, state, and local policies that would increase the resilience of hurricane prone communities. The forum will feature, Mayor Richard Crotty (R) of Orange County, Florida, hurricane scientist Dr. Peter J. Webster, John B. Copenhaver of DRI International, and Jane Bullock, former chief of staff of Federal Emergency Management Agency director James Lee Witt."

The event is free and open to the public, but RSVP is required.

Tuesday, August 21, 2007

DC: Dark, Clammy


Cloudy, very cool, humid. After some welcome rain, mostly in the early morning hours, it's like a bad day at the beach in the Washington metro area: cloudy, damp, and cool. National picked up 1.42" of precipitation, and Dulles had 0.53". Temperatures are near record low maximums, barely reaching 70° this morning and remaining mostly in the upper or even mid 60s this afternoon with some fog and drizzle. Radar shows showers scattered through Pennsylvania and south and west of Charlottesville, but nothing in the immediate area.

Conditions will be slow to improve, but the heat will return by the latter part of the week.

Tonight and Tomorrow

Cloudy, humid, cool, scattered showers possible. Cloudy skies, with some fog and drizzle, will persist overnight. Lows will be near their current readings in the mid and upper 60s. There is a 40% chance of measurable rain. Tomorrow will again be cloudy and damp but somewhat warmer with highs in the mid to upper 70s. The chance of showers is 30%.

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

Tropical Topics

Dean made landfall around 4:30 this morning on the east coast of the Yucatan Peninsula near the port of Costa Maya. It was still strengthening as it approached land as a Category 5 storm with winds of 160 mph. The central pressure of 906 mb was the ninth lowest ever recorded in the Atlantic Basin, and the third lowest at landfall, exceeded only by the infamous 1935 Florida Keys storm and Hurricane Gilbert as it hit Cancun in 1988. This is the first Category 5 landfall in the Atlantic Basin since Andrew in 1992.

The storm weakened quickly to Category 2 over land this morning, but it continued to lash the coast with pounding waves. At 5pm, Dean had just moved offshore into the Bay of Campeche as a Category 1 storm with estimated maximum winds of 80 mph. The mainly westward track will take Dean across the southern end of the Gulf of Mexico and to another landfall in Mexico in the middle of the day tomorrow, after possibly having restrengthened to a Category 3. After that, it should rain itself out as a depression in the mountains of central Mexico.

The transcript of this morning's discussion on hurricanes hosted by is available at the online WaPo.

Political Science: Freedomology

We don't normally cite Faux News here at the Update, but an opinion piece today, "Does Government Weather Forecasting Endanger Lives?" is worth noting, if only for the point that wingnuttery regarding privatization of weather services did not disappear with the resounding defeat of Sen. Santorum at the polls last year. Having fled civil service after only 5 years at NOAA, the Update is no great fan of bureaucracy, but only the most ideologically extreme would claim that government has no role in public safety. This was recognized from the earliest days of the republic; there's a good reason why an immediate ancestor of today's NOAA, the Coast Survey, was founded exactly 200 years ago. It's a fact that the advances in numerical weather prediction during the last 50 years that have made today's forecast accuracy possible have all been government-funded, either directly at NOAA or through support of university research. Private industry could not, and would not, have made the huge investment necessary to produce these results.

The author of the article, John Lott, is an economist. I think we know how accurate their models have been. Like Allan Sloan in today's WaPo, I'm a strong advocate of free markets (after all, they made it possible for me to do this as a public service), but apparently Mr. Lott sees no hypocrisy in being paid by tax dollars as an employee of the University of Maryland.

Monday, August 20, 2007

DC: Damp, Cool
Yucatan, Belize Make the Dean's List


Cloudy, very cool, humid. Following last night's storms which brought a welcome ½" or more of rain to most of the metro area, persistent low clouds (around 2000 feet) and a northeasterly wind north of a stationary front through central and southern Virginia have kept temperatures to fall-like levels. As of mid afternoon, National had seen a high so far of only 71°, and Dulles was at 70°. If the high at National holds through midnight, it will tie the record low maximum for the date since 1929.

Humidity levels are quite sticky, however, with dewpoints generally in the low and mid 60s. Shower activity so far today has stayed mostly north of the Mason-Dixon line, but by post time, storms were developing through western Maryland and southward along the Virginia/West Virginia border.

After the likelihood of more showers through tomorrow, a gradual drying trend will lead to hotter temperatures later in the week.

Tonight and Tomorrow

Cloudy, humid, scattered thunderstorms possible. There is a 40% chance of showers or thunderstorms overnight. Lows under cloudy skies will be in the upper 60s to around 70°. Tomorrow will again be cloudy and damp with a 50% chance of showers and highs only 75-80°.

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

Tropical Topics

After passing just off the southern coast of Jamaica, the center of major hurricane Dean stayed south of the Cayman Islands as it continued its rapid westward trek across the Caribbean today. Next on Dean's list of targets are the southern Yucatan Peninsula of Mexico and Belize. Hurricane Warnings are in effect from Cancun southward in Mexico and along the entire coast of Belize. Hurricane Warnings are also in effect for the west coast of Yucatan for when the storm emerges into the southern Gulf of Mexico. On this path, any effects on the U.S. should be minimal, but that didn't stop FEMA from putting on a PR show with preparations exceeding those for Katrina.

Maximum sustained winds were 150 mph as of the 2pm advisory, slightly under the threshold for Category 5, the highest on the Saffir-Simpson scale. Estimated central pressure was 924 mb, but that had dropped to 918 mb by 5pm. Over the weekend, a reading of 924 mb put the storm in the top 5 of most intense storms in the eastern Caribbean during the satellite era (since 1965).

Climate Corner

Today's entire WaPo science ¾ page is devoted to an article, "Warming Will Exacerbate Global Water Conflicts", discussing the possible effects of rainfall changes arising from global warming.

Seasonal Outlook

Latest seasonal forecast: Click here.

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