Tim's Weather World: Another Eye in the Sky

Hard to imagine a time when forecasters didn’t have satellites but they are a relatively weapon in the meteorologist’s arsenal.  Satellites came on the weather scene back in the early 60s.  The lack of satellite imagery made hurricane forecasting particularly difficult.  The Galveston hurricane in 1900 killed more than 6000 people making it the deadliest natural disaster to ever strike the United States.  Estimates actually vary on the number killed between 6000 and 12,000 when a 15 foot storm surge washed over the island that was only 8.7 feet above sea level at Galveston’s highest point.


Galveston19001_650.jpgToday we have two geostationary satellites constantly maintaining a constant vigil about 22,000 miles above the earth.  NOAA and NASA successfully launched another in a series of meteorological satellites just this past Thursday.  As older satellites are phased out, newer ones will come onboard.  It’s an essential part of the forecast process that helps protect the nearly 35 million people in the United States that live in hurricane prone areas.  While the midwest has been quiet so far this severe weather season, during a typical year nearly 1000 tornadoes can be expected.  Satellites will also help us in forecasting the storms that produce tornadoes which spawn the strongest winds on earth.


Goesp.jpgThe latest satellite in the GOES-P series will also improve space weather forecasts and help warn us about solar disturbances. 






Peeks of sun today, then clouds roll in for the rest of the week

After some morning clouds, haze and patchy fog, the sun should break through today. And Chicagoans should take a good look, because the reminder of the week may be very cloudy. Low pressure will be moving into Kansas today and is then forecast to take a very leisurely trek through the Ohio Valley during the week ahead. Showers associated with the approaching low are expected to reach northern Illinois sometime Tuesday afternoon and then continue off and on into next weekend.
The elusive 50-degrees
After Chicago’s official O’Hare high hit 46 degrees Sunday, it marked the 96th consecutive day with temperatures failing to reach the 50-degree mark, the sixth longest such string in Chicago records dating back to 1871.The 55-degrees reported the first day of meteorological winter, December 1st, was the last day O’Hare recorded a 50-degree high.
An inch or more of rain
There is a wide variation in computer model estimates of rain here this week, but most indicate at least an inch or more total is possible. Runoff from still melting snow pack to the north along with forecast rains could see some area rivers and streams rise to near bank full later this week.

Last subzero reading in March

Dear Tom,
I seem to recall a March subzero reading in Chicago within the last 15 years. Am I right?
Steve, Plainfield

Dear Steve,
Subzero days in March are rare in Chicago with only 15 on the books since 1871, but you are correct that one did occur recently. On March 4, 2002, the mercury plunged to a frigid minus 7 at O’Hare Airport and minus 4 at Midway Airport, giving the city its first March subzero readings since 1982 when it dropped to 1 below on the 8th. Suburban areas were even colder with lows of minus 9 at Barrington, minus 12 at McHenry and minus 13 at both Romeoville and DeKalb. The coldest it’s ever officially gotten in March in Chicago was 12 below on March 4, 1873, and the city’s latest-in-the-season subzero reading occurred on March 22, 1888, when the thermometer bottomed out at minus 1.

March snowfall in Chicago

We should make it through the first two weeks of March with little or no snow here in Chicago. However, historical records tell us that it is fairly rare to avoid snow for the entire month. 

Chicago snow in the month of March

23.1″      Snowiest March on record (1926)

trace       Least amount of snow for the month (trace in 2000, 1997, 1994, 1921 and 1910) 

2.1″        March 2009

7.9″        March 2008

2.3″        March 2007 

Up to six inches of snow is still on the ground in some of Chicago’s northern suburbs. Meanwhile, little or no snow remains in downtown Chicago as well as many of the city’s southern and western subrubs.   

03 07 2010 0750_s.jpg 

Above:  Field School in Northbrook this morning where there is plenty of snow still on the ground 

Below:  The view from Oswego High School in southwest suburban Oswego shows bare ground.  Most of the snow there melted days ago.

03 07 2010 0755_s.jpg