Archive for May, 2010

Busy Hurricane Season Likely
May 27, 2010

The National Oceanic and Atmospheric Administration has issued its’ 2010 Hurricane Outlook for the Atlantic Basin. Forecasters indicate that the 2010 hurricane season is expected to be “active to extremely active”.

The Atlantic hurricane season begins June first and runs through November. The numbers shown in the graphic above carry a 70% probability of occurring and exceed the seasonal average of 11 named storms, 6 hurricanes and 2 major hurricanes in any given year. The reasons for the high expectations are:

  • High altitude winds are conducive to storm development. The Pacific El Nino conditions have dissipated and the resulting wind shear effects are diminished
  • Sea surface temperatures in the Atlantic are at record levels, running up to four degrees Fahrenheit above average
  • Since 1995, the tropical multi-decadal signal has brought favorable ocean and atmospheric conditions in sync, favoring high activity

NOAA will update this outlook in early August, as the huricane season approaches its’ peak period of activity.

The graphic below lists the first twelve names selected for this year’s storms.

John Collins

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Mixed Rain Results
May 24, 2010

The month of May has seen some wide swings in temperatures and mixed results for rainfall.

In general, the region has come up a little short in the rain category despite the recent run of unsettled weather. An exception to the dry conditions is an area of recently heavy rainfall just west of Baltimore.

A narrow band of recurring rain over the Friday-Sunday time frame has produced some rain totals in excess of  2 inches. The map above is a generalization and is based on rainfall estimates from the National Weather Service Doppler Radar installation at Sterling, VA.

It is evident that most of the Baltimore mtero area was left out of the generous rain. The result, continued below average precipitation for the month and year at the area’s official weather recording station.

It should be noted that significant rainfall is not in the forecast for the next week or so.

John Collins

Stormy Friday?
May 14, 2010

This week has seen high temperatures in the 50s, 60s and 70s with lots of clouds and a few periods of rain totaling less than one inch.

A cold front will be moving in on Friday that will bring an end to the unsettled conditions.

The warmer, more humid air ahead of the front will provide the ingredients for scattered thunderstorms late in the day. If storms do develop, some could become strong to severe.

The National Weather Service has identified an area (outlined in green above) in which there is a slight risk for the development for severe thunderstorm activity. This area includes most of Maryland. Hail and strong winds would be the most likely severe feature produced by the possible storm activity.

The passage of the front early Saturday will set the stage for some beautiful weekend weather.

The front will settle in south of the Mid Atlantic region on Saturday and high pressure will provide dry, pleasant conditions for Preakness.

John Collins


Seesaw Temperatures
May 12, 2010

Temperatures this week have been and will be all over the place.

Early week temperatures have been running way below the seasonal averages with morning lows in the 30s in some areas and daytime highs nearly 20 degrees below normal.

A couple of storms systems slated for the middle and end of the week are expected to moderate the temperatures but the area will still be on a roller coaster for a couple of days.

By the weekend, readings should settle into the low 70s for highs with dry weather…..just in  time for Preakness.

John Collins

Cooling Down
May 7, 2010

Changes are coming with the approach of the next storm system.

The system shown in the Friday evening forecast map will bring a chance for a few scattered showers or thunderstorms early Saturday. Following that, some chilly air will move into the area.

The graph above shows above average high temperatures recorded at BWI-Marshall in the past week. The contrast is obvious starting this weekend as below average temperatutres will dominate for several days, followed by close to average readings by the end of next week. Keep a jacket handy.

John Collins