Archive for June, 2008

More Severe Weather Potential
June 23, 2008

An upper level area of low pressure continues to spin over the Great Lakes. Spokes of energy have been rotating around this low and generating disturbances at the surface resulting in showers and thunderstorms, some of which have been severe.

This low will still be over the Great Lakes on Monday and the chance continues that showers and thunderstorms will be moving across the area.

The National Weather Service Storm Prediction Center has indicated that there will be a slight risk for severe weather over portions of the Mid Atlantic region on Monday.

By the middle of the week the upper level low will have lost its’ identity and the “troffiness” that has allowed for unsettled weather in the region for several days will be absorbed in the general westerly flow. The bulk of the first week of summer should be fairly typical with high temperatures in the mid-upper 80s and lows in the 60s. Rain chances will increase a little toward the end of the week as a couple of weak disturbances approach.

John Collins


Sunday Severe Potential
June 22, 2008

An approaching cold front on Sunday will provide the setup for some severe weather in the area. Hail, strong winds and frequent lightening appear to be the highest risk with any storms that develop.

The National Weather Service Storm Prediction Center has targeted Maryland as having a Slight Risk for severe thunderstorms.

John Collins

Late Spring Records
June 17, 2008

These are the last days of spring, temperatures are on the rise and the region has already experienced one significant heat wave, but chilly weather is not out of the question.

The passage of last night’s cool front will introduce a different air mass to the region for a day or two. Upper level low pressure reaching from James Bay to the Mid Atlantic is settling in. The result, the jet stream is taking a little dip to the south and letting some cooler air filter down from Canada.

A quick check of the Baltimore record books shows the following for record lows for the next two days:

Wednesday, June 18 ….. 48 degrees (set in 1959)

Thursday, June 19 ….. 48 degrees (set in 1954)

Records, by their very nature, are tough to break and this air mass is not a particularly cold one so the records are probably safe. It looks like the chilliest morning will be Wednesday with some low temperatures in the region possibly dipping into the upper 40s. Whether readings at BWI-Marshall get that chilly is questionable. We’ll see what happens.

For now, enjoy the pleasant temperatures and lower humidity and pollution levels. All of summer is still ahead.

John Collins

Warm, Humid and Stormy
June 16, 2008

A cold front will be crossing the Mid Atlantic region late Monday. The combination of warm, humid air in place and the front will create a potential for severe thunderstorm activity Monday afternoon and evening.

The National Weather Service Storm Prediction Center has indicated that there is a moderate risk for severe thunderstorm activity over Maryland. That area is outlined over the morning satellite picture below.

Once the front passes through the region early Tuesday, the air mass will be much cooler and less humid. Something to look forward to.

John Collins

What’s Behind the Midwest Floods and Tornadoes?
June 13, 2008

Joe D’Aleo, one of my favorite Certified Consulting Meteorologists, who blogs on ICECAP, has put together a nice piece explaining the relationship between the unusually chilly spring and the massive flooding and frequent reports of tornadoes in the eastern half of the nation.  Joe explains in his blog:  Cool Spring Brings Tornadoes and Flooding to the Central United States that the contrast between the chilly spring air to the north, and the warmth of spring trying to move up from the south, has produced a very energetic jet stream.  The pattern may also produce cooler temperatures over the summer months.  If so, the heat we experienced earlier this week may be rare this summer.  We’ll see!

Tom Tasselmyer

Record Snow + Cold Spring = June Skiing
June 13, 2008

In the Colorado mountains, the record setting snowfall of last winter combined with the cold spring nationwide (36th coolest on record since 1895), has set the stage for some mid-June skiing! With more than three feet of snow left on Aspen Mountain the resort has decided to open the slopes and lifts this weekend for a chance to enjoy a rare taste of winter just one week before summer officially begins! It will be interesting to see if they can keep the slopes open for some Independence Day skiing in July!

Tom Tasselmyer

Heat Wave Misses Record Book
June 11, 2008


Four straight days with temperatures in the low to mid 90s and still no new entries in the Baltimore record book. With records going back over 130 years it is safe to say heat and humidity is nothing new around here in early June. In fact, Baltimore’s “coolest” record high in June is 96, so unless temperatures reach the upper 90s the chances of setting a record this time of year are slim.

Record heat or just late spring in Baltimore, relief is on the way with strong thunderstorms this evening heralding a cold front. Computer models put the front on the eastern shore by 2am and off the coast by around 8am.

Tom Tasslmyer

The Heat Wave Continues
June 9, 2008

We are two days into our first heat wave of the season and we have failed to tie or break the record high temperatures Tom wrote about in the previous blog. This is not a record one strives to go after but as long as it is going to be so darn uncomfortable we might as well go for it.

It looks like the hot, humid streak will last two more days. Monday’s record of 98 appears vulnerable. Tuesday’s record high of 97 might be a little tougher to reach. A cold front will be getting closer and partly cloudy skies may hold the temperatures in the low 90s.

That front and the potential for thunderstorms will eventually break the heat wave and highs are expected to be in the 80s with lower humidity the rest of the week.

All this talk of record heat made me think of the magic number….100 degrees. The earliest in the season we reach that benchmark in the record books is June 5th with a reading of 101, set back in 1925. The June records show that Baltimore has reached the century mark or higher seven times. The hottest of those was 105 degrees set on June 29, 1934.

In the Mid Atlantic region it is the high humidity that makes these hot days so uncomfortable. The best suggestion I can offer is to take it easy, drink plenty of fluids and hang tough until Wednesday.

John Collins

Back To The 90s!
June 7, 2008

Temperatures topped out in the low 80s on Friday; with a max of just 84 at BWI-Marshall airport. Without any 90 degree days so far this spring, this is now the deepest into the year we’ve gone without a day in the 90s since 2003. Back in that year the first 90 was recorded on June 24th. However, it looks like the heat will arrive with a vengeance this weekend. Record highs are possible Saturday, Sunday and Monday. A ridge of high pressure building over the region will produce rising temperatures. The heat will combine with high humidity to produce a heat index over 100 each day. Find a shady, cool spot and drink plenty of water and hang in there, summer officially begins in two weeks (June 20th)!

Tom Tasselmyer

Earliest Triple Digit Temp.
June 6, 2008


June 5, 1925 was a very hot day in Baltimore. With a high of 101 it was not only a record for the date that has stood for 83 years, it is also the earliest recorded temperature of 100 or higher in Baltimore. In sharp contrast to that scorcher, we have not yet recorded an official 90 degree temperature at BWI-Marshall this year. It’s the longest we’ve had to wait for a 90 degree temperature since 2005 when the first 90 was recorded on June 6th. If we don’t reach 90 on Friday, this will be the deepest we’ve gone into the year without 90 degree heat since 2003, when the first 90 came on June 24th.

Tom Tasselmyer