Thursday, May 24, 2007

Gradual Warmup Continues


Sunny, warm. This afternoon's weather map shows a strong high pressure area dominating the eastern third of the U.S. with virtually no rain anywhere east of the Mississippi. The Washington metro area is enjoying temperatures generally in the low 80s with only slightly higher humidity indicated by dewpoints reaching into the upper 50s. The warming trend is likely to continue into the holiday weekend.

Tonight and Tomorrow

Mostly clear, warm. Lows tonight under mostly clear skies will range from the low 60s downtown to the mid and upper 50s in 'burbville. Tomorrow will be sunny and a little warmer, highs 84-87°.

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

Tropical Topics

With the official start of hurricane season a week from tomorrow, the USAT Weather Guys had a pointer yesterday to an interesting collection of tropical cyclone climatology charts at the National Hurricane Center website.

The statistical return period for Category 1 hurricanes in the Mid Atlantic area, shown to the right, is 5 years for the Outer Banks, but 15 years for Virginia Beach and 24 years for Ocean City. Also included on the web site are maps of the actual total number of strikes by county for the last 80 years. The strike data is derived from an NHC technical memorandum which is available for download from the National Hurricane/Tropical Prediction Center library. Caution: These mainly pre-WWW documents were apparently scanned into pdfs which means that they have multi-deca-megabyte file sizes (multi-hour downloads on a dialup connection).

Graphic from NOAA/NWS/NHC

Programming Note: PM Update will be taking a long weekend, so have a great holiday, everyone!

Wednesday, May 23, 2007

Carbon Copy, Carbon Copied


Sunny, warm. Temperatures are a degree or two warmer, high clouds are a little more prevalent, and there are a few more scattered showers along the Virginia/West Virginia border, but today is pretty much a carbon copy of yesterday weatherwise. Temperatures are mostly in the upper 70s with a couple of 80°+ readings in the warmer spots.

Continued seasonably warm and dry conditions are on tap through the end of the week and into the holiday weekend.

Tonight and Tomorrow

Mostly clear, warm. Tonight's moonlit skies will be accompanied by lows near 60° downtown to the mid 50s in cooler 'burbalonia. Tomorrow will feature lots of sunshine, only slightly more humidity, and highs 79-83°.

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

Climate Corner: More Carbon Copied

A paper, "Global and regional drivers of accelerating CO2 emissions", published yesterday in the online edition of the Proceedings of the National Academy of Sciences (PNAS), reports that worldwide CO2 emissions have been increasing at an accelerating rate. The annual rate of increase for the first half of this decade was 3.1% per year compared to 1.1% per year for the 1990s. This rate was "greater than for the most fossil-fuel intensive of the Intergovernmental Panel on Climate Change emissions scenarios developed in the late 1990s."

News of this research appeared on page 1A of USAT ("Global carbon levels spiraling") and also in:
Graphic from PNAS

Tuesday, May 22, 2007

DC: Delightfully Comfortable


Sunny, warm. Southerly breezes have brought temperatures a few degrees warmer this afternoon, but humidities are still comfortable as dewpoints remain in the low 50s. Culpeper and Fredericksburg were the warm spots in the region with 81° at 4pm. Except for a few isolated popup showers near the southern portion of the Virginia/West Virginia border, radar is clear in all directions.

Continued seasonably warm and dry conditions are on tap for the next couple of days.

Tonight and Tomorrow

Mostly clear, seasonable. Lows tonight under a few scattered clouds will be from the upper 50s downtown to the low 50s in the 'burbs. Tomorrow will be a lot like today with highs in the upper 70s to near 80°.

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

Tropical Topics

The National Hurricane Center and Climate Prediction Center today issued the official outlook for this year's hurricane season. The forecast calls for a 75% chance of above-normal activity, including 13-17 named storms, 7-10 hurricanes, and 3-5 major hurricanes (category 3 or higher). Among the factors expected to contribute to the higher activity are: warmer sea surface temperatures, reduced wind shear, and lower surface pressure over the tropical Atlantic, higher upper atmosphere pressure from the central Atlantic eastward to Africa, and a favorable African easterly jet.

Hurricane season outlook graphic from NOAA.

Capitol Climate

Among the climate-related hearings scheduled this week on Capitol Hill is "Potential impacts of global warming on recreation and the recreation industry" by the Senate Environment and Public Works committee on Thursday.

The tentative topic for the next American Meteorological Society Environmental Science Seminar Series the week of June 11 is "Why Should We Trust that the Science of Global Warming is Right?".

Monday, May 21, 2007

As You Like It


Sunny, comfortable. The allergy sufferers and gardeners may have some complaints, but for most people it's a nearly perfect May afternoon in the Washington metro area. Following an overnight cold frontal passage, it took until after 1pm to exceed the midnight temperature of 70°, but by mid afternoon low and mid 70s were widespread throughout the region. Radar is clear for hundreds of miles in all directions.

After similar temperatures tomorrow, a warming trend should set up for the rest of the week.

Surface weather map and satellite picture at 2pm today from HPC/NCEP/NWS

Tonight and Tomorrow

Partly cloudy, seasonable. Under mostly clear to partly cloudy skies tonight, lows will range from the mid 50s downtown to the upper 40s in the coolest 'burbs. Tomorrow will be much like today with highs in the low to mid 70s.

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

A Sinking Feeling

As you may have heard recently, some modelling studies have suggested that the Southern Hemisphere ocean may slow the rate of global warming by being a better CO2 sink than earlier expected. You probably won't hear it from the more rabid blogs, squawk radio, or "Fair and Balanced" cable noise networks, but last week a study in the journal Science based on actual measurements indicated that exactly the opposite appears to be taking place. The data show that the capability of the Southern Ocean to absorb excess CO2 may be already maxing out. The research was reported by the Beeb, the Guardian, and Reuters, among others.

Seasonal Outlook

Latest seasonal forecast: Click here.

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