Archive for November, 2007

Hurricane Season Ends Quietly
November 30, 2007


With the end of November, the 2007 hurricane season comes to a close as well. There were 14 named storms, 6 that grew into hurricanes and just two hurricanes that were considered “major”, reaching category 3 or higher. For the second year in a row we saw fewer hurricanes than the National Oceanic and Atmospheric Administration forecast and the storms that did form tended to be less intense. Another sign of the decline in hurricane activity over the past couple years is the the number of days for which a hurricane exists somewhere in the northern hemisphere. For 2007 so far, there have only been 80 hurricane days, the fewest since 1977 and the third fewest hurricane days since 1958 (see graphic from Ph.D. student Ryan N. Maue’s web site). After the record setting hurricane season of 2005 many feared devastating hurricane seasons would become the norm, but the global oceanic-atmospheric system has once again proven to be far more complex than we understand. The difficulty that the nation’s best hurricane forecasters have in simply predicting the number of storms in a season, let alone where they will be or how intense they will become, should remind us that long range forecasts of local weather or global climate are make great headlines, but are generally not reliable.

Tom Tasselmyer

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Big Storm Season
November 26, 2007

It was a quiet weekend with some chilly temperatures. Saturday morning’s low of 22 stands as the coldest reading of the season so far.

A storm is coming out of the Gulf coast region and is headed this way. The center of the storm will pass just to the west of Baltimore and this means that we will be on the warm side with rain in the forecast. Some areas may receive around an inch of rain.

We are moving into a season that can produce some powerful storms over the Mid Atlantic and Northeastern U.S.

Two memorable storms struck the region on November 25. In 1950 a huge storm generated 57 inches of snow at Pickens, W.Va. and 3 feet of snow in parts of Ohio. Wind gusts over 100mph hit New Jersey and parts of New England. Another storm in 1971(Thanksgiving that year) dumped 1-2 feet of snow over interior portions of the Mid Atlantic and New England. In Baltimore this storm generated 2.41 inches of rain over a two day period and winds gusted to 42 mph.

The question, is anything significant in the outlook over the next few weeks? Long range forecasting is far from reliable regarding specifics but some models hint that a couple of respectible storms could sweep across the area over the next three weeks that have a potential to develop into nor’easters. Indications at this early stage are that these storms (if they develop) would have their biggest impact on New England. The chart below shows a potential storm moving out over the coast a little over a week from now. Note the tightly packed isobars indicating very low pressure and strong winds.

Computer model accuracy improves in the shorter term so we’ll have to wait a few days to see how things play out. Tune us in every day on TV-11, on Insta-Weather Plus or on wbaltv.com.

John Collins

November 23, 1989
November 23, 2007

Weather made the headlines on Thanksgiving Day 18 years ago today. It was November 23, 1989 and John Collins and I had only been on the air here at WBAL-TV for a few weeks. An early season arctic air mass had invaded the mid Atlantic states and with high temperatures in the mid 30s it felt more like Cleveland, the town I had just left. On Wednesday morning, November 22nd, an area of low pressure was developing over northern Louisiana, on the southern fringe of the arctic air mass draped across Maryland. By 7:00 p.m. Wednesday evening, the low had moved to the Alabama/Georgia border, had spread rain and freezing rain into the Carolinas and snow was already being reported in central and northern Virginia. The storm sped toward the outer banks of North Carolina by 1:00 a.m. on Thursday and then tracked to a position over the Atlantic, east of Ocean City, MD by 7:00 a.m. on Thursday. By the time the turkeys were going into the ovens around Baltimore on Thanksgiving morning, the sun was shining on a fresh 3.8″ blanket of snow. To our south, the storm dumped 7″ on Solomons, MD, 4″ at National Airport in D.C. and to our east, Margate, NJ picked up 8″ of snow. With the fresh snow pack and clear skies, temperatures sunk to a record low of 17F on the morning of Friday, November 24th. The winter of ’89 had arrived and would tighten its grip on Maryland with one of the coldest Decembers on record. The average temperature in December of 1989 was a frigid 25.4F, which is 11.3 degrees below normal. John and I would be quickly baptized into Maryland winter weather forecasting with several early season snowstorms and arctic blasts until the pattern eased up with mild weather returning in January and February of 1990.

Tom Tasselmyer

Thanksgiving Weather
November 19, 2007

Thanksgiving is a floating holiday that can fall anywhere from November 22-28. This year Thanksgiving comes on the earliest of those dates but this does not have a significant impact on the weather. This year it looks like we approach Thanksgiving with a warming trend but on the big day itself it appears rain is possible.

The weather chart above shows the moisture running out ahead of a fairly strong cold front. Computer models have been fairly consistent with this idea for several days now. Over the next few days the models will have more data to work with and will provide a more finely tuned idea of how the day will turn out. Stay tuned.

Thanksgiving straddles autumn and winter and historically, anything can happen. Last year there was some light rain in Baltimore and the high temperature was only 48 degrees, a little below the average of 55.

Over the past 30 years, the warmest Thanksgiving was in 1987 when the high hit 71 degrees. The coldest was in 1996. The morning low was 18 and the high was only 33.

Statistically, one in three Thanksgivings will receive measurable rain and one in ten will record snow. Snowfall this early in the season is generally inconsequential but in 1989 a complex storm system moved across the area just before Thanksgiving and brought in some very cold air. A weather disturbance then pushed some moisture into that cold air mass and four inches of snow fell on Thanksgiving Eve and Thanksgiving Day.

This Thanksgiving could be a wet one so check in with Tom, Neal, Sandra and Jay for the latest Insta-Weather Plus forecast for your travel and holiday planning.

John Collins

Wind and Cold and Mountain Snow
November 15, 2007


A few flurries were reported at BWI-Marshall between 10:34 a.m. and 10:44 a.m. last Friday, the earliest in the season we’ve had snow at the airport since a November 1st flurry in 1993. Now, less than a week later, another strong cold front will produce gusty winds, falling temperatures and lake effect snow in the mountains. Travelers headed west through the mountains on Thursday will likely see the rain mix with or change to snow before noon in Allegany and Garrett Counties with snow showers also likely at the higher elevations of the PA Turnpike and up in the mountains of West Virginia. As temperatures drop through the 40s in central Maryland Thursday afternoon, a few spots north and west of Baltimore could also see some wet snow mix with the rain before ending in the early afternoon. Skies will clear around Baltimore Thursday night, but moisture blowing off the great lakes and up into the cold air over the mountains will result in more snow in far western Maryland, Pennsylvania and West Virginia into Friday morning. Accumulations of 2-4″ are possible by midday Friday, especially above 2000 feet.

Tom Tasselmyer

Winter Trends
November 12, 2007

Despite a near term forecast for a brief period of milder temperatures, signs of winter are here, statistically and otherwise.

Last Friday, the first snow of the season was recorded at BWI-Marshall Airport. Observers noted that a trace of snow fell between 10:34 and 10:44 am. If you blinked you probably missed it. Tom Tasselmyer dug into the record books and found that Friday’s report of flakes stand as the area’s earliest in at least 13 years. The same weather disturbance produced several inches of wet snow in northern New Jersey and northeast Pennsylvania.

Other wintery signs in the record books indicate that on this date (November 11) in 1987, a record 6 inches of snow fell at BWI-Marshall and on November 12, 1968, the record snowfall is 3.3 inches. The record low temperature for November 12 is 18 degrees, set back in 1957.

With these wintery signs in mind, the question is, just what will the coming winter be like? Long term forecasting can only point toward broad trends in temperature and precipitation. The National Weather Service’s Climate Prediction Center has generated the following outlooks for December, January and February.

It appears that the weather pattern is not conducive to large scale or long term invasions of arctic air during the main winter months. As far as precipitation is concerned, Maryland falls in the “equal chances” category for rain or snow in the period. This means that there are no compelling “signals” either way in the weather pattern for a stormy or quiet winter in this area. A moderate La Nina is underway in the Pacific and is expected to go into the new year with a weakening trend. The outlook for below average precipitation conditions in the southern U.S. as noted on the map is typical of La Nina.

Of course this is only an “outlook”, not a prediction. Extreme weather is always a possibility, regardless of the long term pattern. As they say, stay tuned.

John Collins

Temperature Benchmark
November 11, 2007

The area has passed a temperature benchmark. The record high temperature for BWI/Marshall Airport on Thursday, November 8 was recorded in 1995 at 80 degrees. The next time an 80 degree reading appears in the high temperature records is on February 25. On that date in 1930 the thermometer hit 83 degrees. This amounts to a 108 day run in which, statistically speaking, the forces of nature prevent the area from having any significantly warm days.

Shorter days and lower sun angle have pushed the area over the edge and we are going down that slippery slope that locks us into colder winter temperatures.

Bundle up.

John Collins

First Flakes Last Five Winters
November 9, 2007

The fast moving clipper that will scoot through the mid Atlantic states tonight and early tomorrow has the potential to produce some early season snowflakes. The threat is mainly for colder areas north and west of Baltimore, especially at elevations above 1000 feet. Any snow sightings around Baltimore would be about a month earlier than the average of the past few winters, but not that unusual for November. Over the past 30 winter seasons in Baltimore, 19 of them have had at least a trace of snow in November and 10 have had at least 0.1″ of snow.

Winter’s First Flakes:
2006-2007: Dec. 7
2005-2006: Nov. 23
2004-2005: Dec. 15
2003-2004: Dec. 4
2002-2003: Dec. 3

Tom Tasselmyer

Noel Near Miss
November 4, 2007

Late season Tropical Storm Noel finally attained hurricane strength after cutting a swath through the Caribbean islands. It didn’t take long though for the storm to lose its’ tropical characteristics. Noel transitioned to a powerful nor’easter, skirting along the Mid Atlantic and Northeast coastline.

The storm was far enough off shore in the Mid Atlantic region that its’ effects were minimal. Gale and storm force winds prevailed along the Atlantic coast with wave heights up to 15 feet.

Significant rain stayed about 40 miles off the DELMARVA coast but radar showed sprinkles and drizzle over the Maryland counties of the Eastern Shore for a brief time on Saturday morning.

The outer cloud bands of the storm pushed as far west as Fredeick and Washington counties.

Winds were blustery most of the day Saturday and were strongest along the coast. Ocean City, MD recorded gusts to 40 mph. Tolchester Beach, on the Bay in Kent County recorded gusts to 30 mph. The peak gust on TV Hill was 19 mph. and BWI/Marshall recorded a gust to 23 mph.

As is typical with this type of storm, clear, dry conditions filled in as the storm moved northward. The greatest impact from the nor’easter will be felt along coastal New England and the Maritime Provinces of Canada where winds could approach hurricane force and heavy rain is likely. Parts of Maine may even receive a little snow.

John Collins

Winters After Warmest Octobers
November 3, 2007

Does the warmth of October tell us anything about the upcoming winter? It is hard to say for sure, but many times the pattern that develops in autumn will at least carry over into the first half or so of winter. With October 2007 going into the record books tied for 5th warmest on record, it will be bad news for snow fans if the warm and dry pattern holds into the winter of 2007-2008. Looking at statistics for the winters following the warmest Octobers of years past shows a definite trend toward less snow and warmer temperatures. For the 10 warmest Octobers on record, two (1879 and 1881) occurred before reliable snowfall records were kept and one (this year) didn’t have a winter to look at. So, here’s a breakdown of the average temperature and snow in the winters following the warmest Octobers on record that have snowfall or temperature records available:

Average Snow: 13.1″…which is 5.1″ below normal…or 72% of normal.
Average Temperature: 38.9…which is 4.9 warmer than normal.

Not exactly the kind of information that snow lovers want to hear about, but encouraging to those who are already dreading winter. Keep in mind, however, that this is not a forecast, just a look at the numbers for a few winters. We shall see what actually unfolds…stay tuned!

Tom Tasselmyer