Archive for January, 2007

First Snow Of February?
January 31, 2007


Low pressure near the Texas gulf coast is producing snow as far south as Memphis, TN this evening. That low is forecast to move east/northeast to a position near Cape Hatteras, NC Thursday evening and then track off shore, well east of Maryland by Friday morning. If the low holds to this forecast track, we’ll have just light snow or flurries with accumulations of a dusting up to an inch or two. The storm will likely impact the area from late Thursday morning until midday Friday. The posted graphic is the forecast of the low pressure center’s postion from the National Weather Service’s Hydrometeorological Prediction Center.

Tom Tasselmyer

Advertisements

Another Nearly Snowless January
January 31, 2007

With no snow headed our way today, January ’07 will go in the books as the second consecutive January with less than 1″ of snow at Baltimore’s official weather station down at BWI Thurgood Marshall Airport. January ’06 had just a trace of snow at the airport and this year we’ve had just 0.9″. January is typically the snowiest month of the year with a normal (30 year average, 1971-2000) snowfall of 7.0″. Will a new month bring some snow? February arrives tomorrow with at least a chance for some light snow, but new computer model data arriving this morning seems to show the main area of precipitation staying to our south, which would result in just minor accumulations; a dusting to perhaps an inch or two for the Baltimore area. More on this approaching storm later.

January Snowfall Since 2000
2000 21.3″

2001 3.7″
2002 2.3″
2003 5.3″
2004 8.4″
2005 7.6″
2006 Trace
2007 0.9″

Tom Tasselmyer

Winter Settles In
January 29, 2007

This January has been unusual. It was not very wintry for the first half of the month. It hit 71 degrees on the 6th. Six days this month registered highs in the 60s and seven made it into the 50s. Only one day so far never made it out of the 20s. Typical highs this time of year are in the low 40s and we have been much closer to that mark in the last week and a half.

January 28 is a significant date in the region’s record books for big snows. In 1772 the Washington/Jefferson storm marooned both patriots on their plantations. Three foot snows were reported across Virginia and Maryland. In 1922 the Knickerbocker storm struck. 28 inches of snow collapsed the roof of the Knickerbocker Theater in Washington, DC, taking the lives of over 100 people. The storm dumped a record 23.3 inches of snow on Baltimore. In 1998 a major nor’easter was pulling away from the area. Ghent, West Virginia received 42 inches of snow. Flat Top, West Virginia piled up 35 inches in 24 hours and Beckly received 31 inches. Wind gusts to 83 mph were recorded along the Mid Atlantic coast. An unofficial wind gauge on the roof of an Ocean City hotel recorded a gust to 112 mph. Frederick, Maryland received only some wet snow in the storm. It was all rain in Baltimore, 2.02 inches to be exact, over the two day period. The peak gust at the airport was 37 mph.

It looks like the end of January in Baltimore will be a little colder than average. Highs are expected to be in the upper 30s to near 40 with lows ranging from the upper teens into the low 20s.

Keep Warm.

John Collins

Spring And Winter In One Month
January 26, 2007


With the arrival of very cold arctic air tonight, January 2007 is shaping up as a month of big contrasts. The first 16 days of the month had an average temperature of 47.1F, an amazing 14.7F above normal for better than two weeks! Pending the final numbers from tonight’s cold blast, the period from January 17th through the 25th has had an average temperature of about 31.1F. Now that’s just one degree below normal for those nine days, but compared to the way this month started, dropping the average temperature by over 15 degrees is fairly dramatic. The extended outlook keeps the cold locked into the eastern United States into at least early February. With El Nino still keeping the southern branch of the jet stream energized, we’ll have to keep a close eye on possible storm developments to our south that would pose a winter weather threat while this cold pattern is in place. The image posted shows the National Weather Service Climate Prediction Center 8-14 day temperature outlook for the U.S., covering the period from February 2nd through the 8th. Below normal temperatures are expected in the blue shaded areas east of the Mississippi. Bundle up!

Tom Tasselmyer

Sunday Snow
January 22, 2007

The first significant snow of the season wasn’t a blockbuster but it did manage to snarl traffic for a while late Sunday.

Snow reports include: Essex, 1.0″; WBAL/TV Hill, .75″; Ellicott City & Hunt Valley, .50″; BWI, .90″; Crofton, 1.5″; Owings Mills, 1.2″; Jessup, 1.4″; Laurel, 1.9″; Bowie, .60″; Frostburg, 3.0″.

The sounding balloon launched at Sterling, VA at 7pm Sunday showed that southwest winds in the lower atmosphere pushed the temperature to near the freezing point in the first few thousand feet while staying below freezing at the surface (surface winds were generally east-southeast). This is why “mixed precipitation” was included in the overnight forecast with an icing situation possible during the overnight hours.

Persistent clouds in the wake of the storm should hold temperatures below the seasonal average on Monday and precipitation chances appear minimal during the daylight hours.

The next disturbance in the pipeline should be midweek but will be riding pretty far to the north. Rain/snow chances are not all that great but a chance for a precipitation “wintry mix” was included in the extended outlook for Wednesday night. Not confident with the timing of this if it does develop. We’ll see.

John Collins

First Snowfall In Nearly A Year?
January 21, 2007

Low pressure approaching from the west, should pass south of Baltimore tonight, emerging on the coast near Norfolk, VA early Monday morning. On this path a light snowfall is expected for much of central Maryland. The last official snow accumulation at BWI-Marshall airport was back on February 11th and 12th of 2006, about 342 days ago! With some warmer air possibly mixing into the storm, snow may change to, or mix with sleet and some freezing drizzle before it tapers off in the pre-dawn hours of Monday. A general 1-3″ snowfall is most likely with the typical variations depending on ground temperatures, proximity of the warmer bay and the amount of sleet or freezing drizzle that develops. The higher snowfall totals are likely to be a little south of Baltimore with the lighter accumulations north of the city, near the Pennsylvania line. Winter is back!

Tom Tasselmyer

Carolina Storm Should Stay East
January 19, 2007


Low pressure developing off the Carolina coast is staying far enough offshore to keep any precipitation in Maryland on the light side. Just trace amounts of light rain with a few ice pellets and flakes of snow have been reported around Baltimore through the evening. Closer to the coast, Salisbury and Ocean City have picked up .14″ and .23″ of rain respectively. Although the storm has had a minimal impact on Maryland, it is expected to strengthen on its treck north toward New England Friday, with heavy snow possible in northern and western Maine. Northwest winds on the backside of that intensifying New England storm will draw another shot of arctic air into the mid Atlantic states for the weekend. Wind gusts over 40 mph will be possible around Baltimore from late Friday through Saturday. Lake effect snow will accumulate several inches Friday and Saturday in Garrett Co. and the sourrounding mountains of West Virginia and Pennsylvania. In the meantime, the southern branch of the jet stream will remain very active through the weekend, possibly sending another winter weather threat our way by Sunday night into Monday. The posted image is the National Weather Service’s WRF model valid at 1pm Friday showing the big storm pounding Maine with wind and snow while a new storm begins to take shape over the southwestern U.S.

Tom Tasselmyer

Carolina Snow Moving North
January 18, 2007


Early morning observations show snow and sleet across central NC with some freezing rain farther south into the mountains of SC and the hills of north Georgia.

Raleigh, NC Light Snow, 28F
Charlotte, NC Freezing Rain, 28F
Columbia, SC Freezing Rain, 32F
Atlanta, GA Freezing Rain, 32F

Pressure falls are occuring along the outer banks where a low pressure center is trying to organize. Overnight computer models show the precipitation staying mainly south and east of the Baltimore area as the storm moves north today and tonight. A chilly, light rain is expected for much of the eastern shore this afternoon and evening with just a few 1/100ths of an inch of precipitation making it west of the bay in the form of light rain, sleet or flurries. The storm should pull out of the area after midnight and intensify, heading for New England as a much more potent winter storm on Friday. Strong gusty winds behind the storm will pull in even colder arctic air for the start of the weekend. The image posted here is from the high resolution WRF computer model run at the Baltimore/Washington National Weather Service Forecast Office, valid for 5pm today. Green is rain, red is sleet and blue is snow. The low is seen just southeast of Wilmington, NC.

Tom Tasselmyer

Wintry Mix Possible
January 17, 2007


The coldest air of winter so far will retreat to the northeast tonight, allowing mositure from a very active southern branch of the jet stream to move toward the mid Atlantic states. Low pressure is expected to develop off the South Carolina coast early Thursday morning and then track northeast toward the outer banks of North Carolina during the day. The storm will likely brush past Maryland as it tracks off shore and rapidly intensifies near Cape Cod on Friday. If the storm holds to this track (a big “if”), rain, sleet and snow will move from North Carolina into central and southeast Virginia during the late morning of Thursday. A chilly rain will spread onto Maryland’s lower eastern shore during the afternoon with a chance of light sleet or snow west of the bay during the late afternoon and evening. Precipitation, of any variety, is expected to be light in the Baltimore area, generally .10″ to .25″, which combined with warm ground temperatures, will limit potential snow and sleet accumulations to an inch or two. There is still the very real possiblity of the storm staying to our south and east with little or no precipitation falling west of the bay. The image posted here shows the 1pm Thursday forecast from the high resolution WRF model run at the Baltimore/Washington National Weather Service Forecast Office. Green represents rain, red and purple show areas of sleet or freezing rain and blue is the forecast snow. New computer model runs tonight will hopefully add some insight. More updates as the storm approaches.

Tom Tasselmyer

Spring To Winter
January 15, 2007

Through the first 14 days of January 2007 temperatures at BWI-Marshall Airport are averaging 13.4F above normal. The average temperature for the month so far is 45.8F, which, if the month ended today, would be good enough for third warmest all-time, just behind the Januarys of 1932 (47.4F) and 1950 (46.9F). But, spring in January is about to come to an end.

An arctic cold front is creeping slowly closer to Maryland and should slide through the Baltimore area just after midnight tonight. As of 7am Monday morning the front had dropped south through much of New England and was about to move through Boston. It was raining and 38F at Boston, but snowing with the temperature down to 18F at Saranac Lake, NY. Winter was moving south through the great lakes region as well with freezing rain and 32F in Detroit, while Cleveland was holding onto rain and 52F. The core of the bitterly cold air was entering the upper Midwest with Devil’s Lake, ND down to -24F and Hallock, MN, in the northwest corner of that state, a bone chilling -27F as of 7am e.s.t. The front will bring a chance of showers to the mid Atlantic states today with the rain changing to snow showers in the mountains after the front passes late tonight.

Here in the Baltimore area we could see temperatures slowly falling for an entire 24 hour time period. When the front moves through between 1am and 4am Tuesday, temperatures will likely be in the 50s but begin to fall slowly through the 40s during the morning, dropping into the 30s by late Tuesday afternoon, then settling through the 20s Tuesday evening and finally bottoming out in the teens Wednesday morning. Better find that long lost winter coat…fast!

Tom Tasselmyer