Archive for April, 2008

Late April Snow
April 30, 2008

Snowfalls at Keyser\'s Ridge, MD, April 29, 2008

The cold front that triggered the severe thunderstorms in Maryland and tornadoes in southeast Virginia as it tracked through the area Monday evening also dragged in some rather chilly air. Across the higher mountains of Virginia, Maryland and West Virginia, rain changed to snow showers early Tuesday morning. The Maryland State Highway Administration’s webcam at Keyser’s Ridge in Garrett County captured the winter-like scene around 8:00 a.m. Snow was sticking to the grassy areas, trees and Interstate 68. Temperatures eventually climbed into the 40s during the afternoon, but it was an unusually cold April 29th, even for Garrett County, “The Ice Box of Maryland”.

Tom Tasselmyer


Tornado Anniversary
April 28, 2008

An interesting coincidence on Monday. The Baltimore region falls withing the “Slight Risk” area for severe thunderstorm activity as determined by the National Weather Service’s Storm Prediction Center.

Baltimore is on the northern edge of the “Risk” area and conditions are marginal for severe storm development but it is a situation that should be monitored.

The coincidence is that Monday is the anniversary of the La Plata tornado of 2002. This was an unusually strong storm for the Mid Atlantic region. Below is a NASA satellite picture that clearly shows a portion of the debris path of the storm along with a few statistics.

The storm touched down on the western edge of Charles County and over the period of an hour and a half moved eastward, across the Chesapeake Bay and dissipated on the Eastern Shore. A complete report with pictures and graphics is available at: ttp://

John Collins

Cooler Temperatures Return
April 27, 2008

It’s been a nice run. Temperatures this week have been running 10-15 degrees above the seasonal average.

A Saturday cool front and another storm complex on Monday will drag the high temperatures back into the 60s which are more typical for the season.

The Monday storm is expected to be a pretty good rainmaker and that should help restock the water reserves in the region. As of Saturday (April 26) afternoon the April rainfall at BWI-Marshall is .68 inchesĀ above the seasonal average. The region is still short for the year though by 2.10 inches.

Monday’s storms may also be setting the area up for some severe weather and this will be something to watch for.

John Collins

Saturday Evening, April 26..8:10pm
April 27, 2008

A line of strong thunderstorms is approaching the area from the northwest. The storms are lined up from southern Pennsylvania to near Taneytown to just west of Frederick to just east of Martinsburg and are moving east at 15 to 20mph. These storms are producing many cloud-to-ground lightening strikes and this is probably the most dangerous activity right now. Some of the lightening is hitting the ground about 10-15 miles ahead of the actual storm. These storm cells have the potential to produce small hail and wind gusts to 40 mph. If the line holds together it will reach the western and northwesrn edges of the Baltimore metro area in about 1 hour.

John Collins

Another Pollen Record
April 26, 2008

David Kerxton reported Friday morning’s pollen count set a new record, obliterating Thursday’s all-time mark. The number of pollen grains in a cubic meter of air, sampled in Owings Mills early Friday, was a whopping 4,005! Most of the pollen was frorm trees with some grass pollen and one grain of weed pollen. Expect a continuation of the high pollen counts until a cold front can move into the area with a few showers Saturday afternoon and evening. To see Rob Roblin’s report on the record setting pollen counts, go the video section of

Tom Tasselmyer

Pollen Count Soars
April 25, 2008

David Kerxton the, “Pollen King”, who counts the number of pollen grains in a cubic meter of air and sends the tally to us here at WBAL-TV each morning, reports that the Thursday morning count was a record for the 12 years he’s been looking at pollen in his microscope. David counted 2,550 grains of pollen in the sample of air he monitored atop the offices of Dr.s Golden, Matz and Rosenberg out in Owings Mills. Most of this was tree pollen with some grass pollen mixed in. If you suffer from pollen allergies, hold on, we are likely to have another very high count on Friday and perhaps Saturday. Relief may come in the form of a cold front moving through Saturday evening, which should be able to produce a few showers to wash out the atmosphere.

Tom Tasselmyer

Beneficial Rain
April 22, 2008

While Sunday’s storms brought severe weather and two confirmed tornadoes in Maryland (see post below), they also provided the area with some beneficial rain. With rainfall totals of 1.5″ to 4″ in many areas of central Maryland, the reservoirs are gradually filling to near capacity. Great news as we inch closer to the hot weather of late spring and summer. An email we recieved Monday afternoon from Kurt Kocher of the Environmental Services Division of Baltimore provided the numbers on the graphic posted here. Sunny, warm days in spring are wonderful for getting outside but an occasional soaking rain can also be appreciated.

Tom Tasselmyer

Sunday Storms
April 21, 2008

Sunday, a storm complex moved from the Great Lakes to northeast North Carolina. The combination of moisture and upper air dynamics produced areas of excessive rain and some severe weather. The map below touches on the highlights.

The storm will slowly exit the area Monday. Easterly winds left in its’ wake will keep us cloudy, cool and a little wet for a day or two.

John Collins

April Warm Spell
April 19, 2008

After a week of sunshine and a consistent warming trend, temperatures soared into the 80s on Friday. It wasn’t a record but it felt great. The record high for the date was 94 degrees, set in 1896.

A change is in the air. Unseasonably warm temperatures and fair weather will continue Saturday but an approaching cold front will abruptly change things on Sunday with a chance for rain and temperatures cooling by 15 to 20 degrees. An easterly wind fetch is expected early next week and this will likely result in considerable cloudiness and temperatures on the chilly side of the seasonal averages. Keep the jacket handy.

John Collins

Desert-Like Temperature Ranges
April 16, 2008

High pressure stretching up and down the eastern seaboard from Maine to Florida will continue to produce dry weather in the mid Atlantic states for a few more days. The sinking air under the high pressure system is quite dry, which combines with clear skies and light winds to produce desert-like temperature ranges and variations. For example, on Wednesday at BWI-Marshall, the temperature went from a morning low of 35 to an afternoon high of 67, a temperature range of 32 degrees. At Frederick, MD the affect was even greater, with a low of 28 and an afternoon high of 72…a 44 degree swing! Look for more wide ranging temperatures Thursday and Friday as this weather pattern is expected to hold through the work week.

Tom Tasselmyer