Friday, September 23, 2005

"I still see her dark eye[s] glowin'"

It may be a little hard to believe just looking out the window, but it's the warmest day this month in the Washington metro area. The official temperature hit 90 by 2pm, and it was 92 an hour later. Dewpoints are in the sticky 60s. Radar at mid afternoon showed some scattered showers and possible thunderstorms, mainly in the region east of Elkins, West Virginia, and north of Charlottesville. A line has now formed east of I-81 and south of I-66 which will probably stay south of the metro area.


There is still a chance of scattered showers or thunderstorms through this evening. Temperatures will cool and humidities will drop tonight as a cold front near the Mason-Dixon line early this afternoon makes its way through the area. Lows will be in the mid 60s. An easterly flow behind the front will keep skies mostly cloudy tomorrow with temperatures in the mid 70s.

Tropical Beat

Hurricane Rita has been gradually weakening, but it is still a dangerous Category 3 storm with maximum winds of 125 mph as of 5pm. The center of the storm is located about 155 miles east-southeast of Galveston, and it's moving northwest at 12 mph. With a turn a little to the north, it will make landfall early tomorrow morning somewhere between Galveston and the Texas/Louisiana border, closer to Port Arthur than Galveston. The exact position of landfall is important for the location of maximum storm surge, but the area of hurricane force winds extends up to 85 miles from the center, and the area of tropical storm winds extends up to 205 miles from the center.

Minimal Tropical Storm Philippe is now drifting west to threaten Bermuda with tropical storm winds before being absorbed by another low pressure area.

Political Science: Disaster Planning or Planning Disaster?

The WaPo's editorial "Anticipating Rita" may be just a wee bit premature. With Houston hopefully spared the worst impacts of what could have been a more apocalyptic scenario, there could still be some second-guessing on the storm preparations. An "evacuation" which proceeds at half the speed (50 miles in 12 hours) of a storm traveling 9 mph might not be the most efficient that the greatest technological society the world has ever known is capable of. This is especially true if the evacuation process ends up killing more people than the storm itself. Evacuate Galveston in this situation? Absolutely. Evacuate most of metro Houston as well? Probably not. Granted, there are large areas of Harris County which are prone to flood and should be evacuated, but if 2 million people are living in such conditions, it's time to rethink some zoning rules. There are undoubtedly many people who could shelter in place if they know who they are and where to go. Do you know what your altitude is? Many parts of DC are quite low; the elevation of National Airport is only 10 feet. Here in Montgomery County not too far from the Beltway, it's more like 300 feet. (The only reason I know this is because I needed to set the altitude for my barometer.) It's time to ask government officials at all levels some serious questions about what they have done with the hundreds of billions of dollars they have spent in the past 4 years preparing to Defend the Motherland.

Thursday, September 22, 2005

"I still hear your sea winds blowin'"

As Josh noted in the comments, we've got the muggies to go along with the warm temperatures in the Washington metro area this afternoon. Although the temperatures in the upper 80s are well above the long-term average for the date of 77, the record of 98 set in 1895 is in no jeopardy. (That must have been quite a heat wave in 1895: All of the temperature records for the 5 days from the 19th to the 23rd of September were set that year. The records ranged from 94 through 98.) Unfortunately, there is no rain in sight to break our nearly month-long drought.

Tonight will be mostly clear with lows near 70 in the city, upper 60s in the suburbs. Clouds will increase tomorrow afternoon as a cold front approaches from the Midwest. There is a 40% chance of showers.

Tropical Beat

After reaching maximum sustained winds of 175 mph and an estimated minimum pressure of 897 mb, Rita has weakened to Category 4 at "only" 145 mph. The Weather Channel has noted that this is only the third time that there have been 2 category 5 storms in the same year. The other 2 years were 1960 and 1961. If Rita makes landfall as a Category 4, it will be only the second time that 2 storms have made landfall in the U.S. at Category 4 or higher in the same year. (The other year was 1915.)

At 5pm, Rita was located about 405 miles southeast of Galveston, headed west-northwest at 9 mph. The good news on the forecast track is that it has shifted to the east of the immediate Houston/Galveston area, so the highly-populated (and low-lying) area could be spared the worst impact. The bad news is that it puts the worst effects into an area with a high concentration of offshore oil platforms and an onshore area with about 25% of the entire country's refinery capacity. The 5pm update also raised tropical storm warnings as far east as (shudder) New Orleans.

Rita Resources

If you have connections to the Houston area, or just want to follow what is happening there, the Houston Chronicle has special coverage online. As of mid afternoon, cable news was showing 5 or 6 lanes of northbound I-45, plus several feeder lanes, completely gridlocked, while police were attempting to clear the southbound lanes for reversal. Wolf Blitzer was haranguing the police chief over "why it took so long."

The Chronicle science reporter has a SciGuy blog on the storm, although the link was broken when I tried it earlier. Here are some interesting storm discussion sites I gleaned from the SciGuy:The National Center for Atmospheric Research (NCAR) is running an experimental super-high-resolution model (4 km) called the ARW, but like most research, it's a bit later than real-time. The output currently displayed is from last night's 00Z (8pm EDT) data.

Wednesday, September 21, 2005

Lovely Rita, Meteorology Maid

5:15 update: Rita was upgraded between advisories to Category 5, max winds 165 mph; min pressure by recon is 914 mb. The forecast track has been shifted toward the right (in the direction of Galveston/Houston). Hurricane watch is in effect for Port Mansfield Texas to Cameron Louisiana.

The Washington metro area weather is lovely as Rita rampages across the Gulf of Mexico. Temperatures are mostly in the low to mid 80s, although to the south Stafford and Fredericksburg are near or at 90 this afternoon. Dewpoints are in the mid 50s or lower. As Dan said earlier, warm and dry will be the rule here for the next several days. Showers and thunderstorms which developed yesterday were too far to the south and east to help the drought in the immediate area.

Tropical Beat

Hurricane Rita strengthened dramatically overnight to Category 4. The morning advisory estimated maximum winds of 140 mph because the reconnaissance plane was prevented from flying by mechanical problems, but satellite analysis indicated even higher strength. This was updated at 2:15 to 150 mph and a minimum pressure headed for record territory at 920 mb. As with Katrina, a huge eye has developed, and the size of the circulation has expanded as well, easily stretching from the northern Yucatan across half of Cuba to southern Florida. At 11am, the storm was centered 755 miles east-southeast of Corpus Christi, Texas. It was moving westward at 13 mph. The expected track puts the center on the Texas coast early Saturday, probably between Corpus Christi and Galveston, but there is still a large cone of uncertainty.

Tropical Storm Philippe is still around, but it is looking more ragged as it moves north ward to the east of Bermuda.

Broadcast News

The Diane Rehm show on WAMU-FM (88.5) had a discussion this morning with Dr. Judith Curry of Georgia Tech, a co-author of the Science magazine hurricane study we cited last Thursday, and Dr. William Gray of Colorado State, who predicts seasonal tropical storm activity. Also on the panel was Dr. Anthony Busalacchi of the University of Maryland. The main conclusion of Dr. Curry's study is that there has been about a doubling in the number of severe tropical cyclones (Category 4 and 5) since 1970. This is despite the fact that the overall number of storms has not increased. As she explained on the show, the study was careful not to draw any causal connections between global warming and the higher storm intensity. (Some general media reports have not been as precise in their interpretations.) Dr. Gray claims that the study and its conclusions are flawed on several grounds:
  1. The period of record is not long enough.
  2. The researchers don't have enough experience.
  3. It's too hard to distinguish between categories 3 and 4.
  4. The agreement between the statistical data and model results is irrelevant.
  5. All variability is explained by a multi-decadal oscillation.
Fortunately, the connection between congeniality and quality of science is not very strong, but to this observer, Dr. Curry came across as much more reasonable than Dr. Gray. It didn't quite descend to the level of a classic Saturday Night Live "Jane, you ignorant slut", but Dr. Gray did have a "my way or the highway" view of the data, implying that only he had been doing this long enough to know how to properly do the analysis. He also had what can only be described as a contemptuous attitude toward computer modeling, using what sounded like the technical term "hooey" to describe model results.

In a sad sign of how much science has become politicized, one of the first callers, at about 34 minutes after the hour, questioned the source of funding for the researchers. (In a profile in this month's Discover magazine, Dr. Gray implies that his NOAA funding was cut off by the Clinton administration for political reasons.)

The show is scheduled to be repeated tonight at 9, and it is also available on the show web site.

Dr. Patrick Michaels of UVA has a critique of Dr. Curry's Science article at Tech Central Station.

Google is a new financial supporter of the NOVA science series on PBS, and the search term typed into the screen display in the underwriting message on the show last night was "Meteorology". Go Google!

Added later:
An analysis of Gray's point of view at RealClimate the following year ("Gray and Muddy Thinking about Global Warming") generated a lively debate.

Tuesday, September 20, 2005

Readin' Rita

Sometime between 1pm and 2pm, the official Washington temperature hit 90 degrees for the 6th time this month. Humidity has also increased, with dewpoints in the low to mid 60s. Some showers which developed near Annapolis around mid afternoon have spread into a broken line from the Maryland middle Eastern Shore across the lower Potomac to the Northern Neck of Virginia and towards Richmond. Easton, MD reported a heavy thunderstorm around 3:45 and precipitation of 0.20". There is nothing to the west which would bring some relief for our developing drought.

Tonight and Tomorrow

The chances of an isolated shower developing through this evening are only about 10%. Lows will be in the mid 60s under clearing skies. Tomorrow will be sunny with highs in the mid 80s and lower humidity.

Tropical Beat

After remaining a tropical storm overnight, Rita quickly strengthened into a hurricane this morning. It is now a Category 2 storm with max winds of 100 mph. At 5pm, the center was about midway between Key West and Havana, moving west at about 15 mph. Key West was recently reporting an east wind at 41 kt, gusting to 50. Hurricane warnings are in effect for the Florida Keys and for the coast of Florida from Florida City on the east around to Chokoloskee on the southwest coast. Tropical storm warnings are also in effect for portions of the Florida coast northward to Jupiter Inlet on the east and Englewood on the west. Rita is expected to strengthen further as it makes its way into the Gulf of Mexico.

Rita's future path depends on the behavior of a huge ridge of high pressure which was stretching this afternoon in the middle of the atmosphere (500 mb level) from Arizona all the way across to the southeastern U.S. coast. (Notice the big area enclosed by the line labeled 594 and the unusual 600 line enclosing the peak of the ridge over Texas.) This had actually strengthened a little from this morning, but it also shifted to the east. The ridge will weaken as a low-pressure trough now off the California coast moves eastward, but the main factor will be a second trough developing over the West Coast toward the end of the week. If that trough is deep enough, it will force the steering currents over the Gulf to be more from the south, and the hurricane will take a more easterly path, perhaps as far east as western Louisiana. Otherwise, it could move into the southern Texas coast or possibly even northern Mexico.

Monday, September 19, 2005

Drought and Flood

5pm update: Rita remains just below hurricane strength, but is expected to reach that level soon, probably tonight. The track is essentially unchanged, but slightly faster.

The long warm, dry spell continues in the Washington metro area. A few showers have been tantalizingly close in the past week. Although National observed rain on 4 consecutive days, only 1 (Thursday) had even 0.01 inch. Those same 4 days also each had double-digit temperature departures above "normal" (long-term average). Temperatures this afternoon are again in the mid to upper 80s, but the official high will likely be a little below the 90-degree level reached 4 times within the last week. The radar is clear in all directions.

Tonight and Tomorrow

Warm conditions will continue through tomorrow, with lows tonight in the upper 60s to around 70. Highs tomorrow will be around 86, and there is only a 30% chance of afternoon or evening showers.

Tropical Beat: "Houston, We May Have a Problem"

With the memory of Katrina fresh, the media are wasting no time recognizing the significance of Tropical Storm Rita. At 2pm, the storm was nearing hurricane strength over the central Bahamas; max winds were near 70 mph and the estimated central pressure was 993 mb. The center was about 380 miles east-southeast of Key West, moving west-northwest around 14 mph. The short-term track is clearly through the Florida Keys into the Gulf, but after that there is a range of opinion. The GFDL model, which has a good record with hurricanes, and the official track, put the storm near Houston by the weekend. However, New Orleans is within the eastern portion of the "cone of uncertainty."

Rita is the earliest 17th storm of the season. The only other one which occurred before Oct. 7 was the tropical storm which formed on Sept. 28, 1933.

Hurricane Philippe is being steered northward east of the same high pressure ridge which is keeping Rita moving westward. This is keeping the minimal hurricane (max winds 75 mph) safely east of the Leeward Islands. It is expected to pass east of Bermuda on Saturday.

To the east, a large area of storms halfway between the Antilles and Africa remains disorganized, and upper-level winds are unfavorable for development.

Broadcast News: Megaflood

Set your TiVo for a different kind of "Storm Stories" on the PBS NOVA program tomorrow at 8pm on channel 26. This is the story of a gigantic flood near the end of the last ice age which sculpted large areas of the Pacific Northwest. Personally, I was unaware of this until I traveled in the region about 10 years ago, but it's an amazing tale of the melting of a glacier thousands of feet thick which had formed an ice dam, creating a lake half the size of Lake Michigan in the basin near what is now Missoula, Montana. The bursting of the glacial ice dam produced a flood as much as a thousand feet deep which shaped hundreds of miles of landscape in eastern Washington state. Recent evidence shows that this pattern of damming and flooding may have occurred repeatedly.

Seasonal Outlook

Latest seasonal forecast: Click here.

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