Record Heat Fuels Historic Tornado Outbreak

Video (click to play): Tuscaloosa, Alabama tornado by Chris England from University of Alabama, via YouTube

For related record temperature posts, see:

• Record Heat
• Record Cold

6 PM Update: NCAR Currents has just published an analysis of the factors leading to such a high death toll in yesterday's tornadoes:
Recipe for calamity: The ingredients of a horrific tornado outbreak

The overall death toll has now been reported as 272 across 6 states.

Original post:
OK, let's get the caveat out of the way right up front: No individual temperature ever caused a specific storm.

When a pattern persists over a large area for an extended period of time, however, it's worthy of notice. The latest reports indicate hundreds of people killed, 162 in the state of Alabama alone, from the tornado outbreak which pounded the Southeast yesterday (April 27). The National Weather Service's Storm Prediction Center has a preliminary count of 164 tornado reports for the day and 3 additional reports so far today. This is the culmination of a month which has undoubtedly broken the April tornado record with 453 separate storms tallied by The Weather Channel. This total, which apparently does not yet include the widespread outbreak of April 27, smashes the previous record of 267 in 1974 and approaches the all-time monthly record of 543 set in May, 2003.

Temperature is only one factor in the development of severe storms, but heat provides the energy which makes thunderstorms and their associated tornadoes possible. So far this month, NOAA's National Climatic Data Center reports 1759 record high temperatures in the U.S. vs. 310 record lows, a ratio of nearly 5.7 to 1, exceeding even March's 5.3 to 1. This is the highest since the ratio of 6.1 last April. There have now been 13 out of the last 14 months with more heat records than cold records. The cumulative ratio since January 2010 is 2.2 to 1.

As shown on the map to the right, April temperatures to date have been above the long-term average across much of the U.S., particularly over the southern portion of the country.

Images (click to enlarge):

• Radar image at 10:25 am, April 28, shows showers and thunderstorms stretching almost continuously from the Canadian border southward to the Gulf of Mexico, from Intellicast
• Tornado and severe storm reports for April 27, from Storm Prediction Center
• Monthly total number of daily high temperature, low temperature, and high minimum temperature records set in the U.S. for November 2010 through April 2011, data from NOAA National Climatic Data Center, background image © Kevin Ambrose (www.weatherbook.com). Includes historical daily observations archived in NCDC's Cooperative Summary of the Day data set and preliminary reports from Cooperative Observers and First Order National Weather Service stations. All stations have a Period of Record of at least 30 years.
• Cumulative excess of heat records vs. cold records by month for 2010 and 2011 to date, data source as above
• Preliminary April 2011 monthly temperature departure from climatological average from NOAA/NCEP via ESRL

Hottest Easter Keeps UK on Track for Warmest April on Record

The hottest Easter in at least a century in Britain is keeping this month's temperatures on a pace to break the 2007 record for the warmest April in history. The highest temperature over the weekend was 27.8°C on Saturday at Wisley, in Surrey. In London, the temperature was 27.1°C on Saturday and around 25°C on Sunday, vs. a normal high of 15°C at this time of year.

Over 100,000 people were estimated to have flocked to southern beaches this weekend.

London temperatures this week are forecast to range from a high of 22°C on Monday to a more seasonable 13°C for the Royal Wedding on Friday.

Temperatures in April to date have been well above average over most of Europe, with the highest departures in Spain, France, and Germany.

Images (click to enlarge): Weekend crowds at Brighton beach, England, from UK Guardian; European temperature departures from average for April, 2011 to date, from NOAA/ESRL

Bad Friday: St. Louis Tornado Rated EF-4

Images (click to enlarge): Radar image at 8:30 pm CDT, April 22, showing intense thunderstorms and EF-4 tornado moving through St. Louis area, from Intellicast; St. Louis tornado track from NWS; Storm damage at St. Louis airport from NWS

A tornado which caused extensive damage in the northern suburbs of St. Louis on Good Friday evening, April 22, has been rated EF-4 on the enhanced Fujita scale by the National Weather Service (NWS). EF-4 includes winds of 208-260 mph, with gusts as high as 261 mph. The storm was one of 2 tornadoes in the St. Louis metropolitan area. It was the strongest tornado in St. Louis County since January 24th 1967. The NWS reports, "Some of the most intense damage occurred in St. Louis County across Maryland Heights, Bridgeton, St. Ann, Edmundson, Lambert St. Louis International Airport, Berkeley, and Ferguson and in Madison County near Granite City." At the airport,

Many of the large windows in the main terminal building were blown out or damaged by flying debris and a large section of roof was peeled from Concourse C. Although the vast majority of people were evacuated to lower levels and to interior rooms before the tornado hit, 5 people were treated and released from area hospitals for injuries due to flying debris. The airport was closed due to the extensive damage.

Some flights had resumed by Sunday, with full operations expected by midweek.

The lack of deaths from the storm was attributed to the advance warning of at least half an hour and excellent response by the public.

This was the second major tornado outbreak in a metropolitan area in less than a week, following the Raleigh tornado last Saturday, April 16. The Weather Channel reports that there have been 28 tornadoes in St. Louis County since 1950, but there have now been 2 of them since New Year's Eve, both EF-3 or higher.

Early Start to Tropical Season?

April 25 Update: NASA has a recap of the storm's demise (System 91L):
Fizzled Tropical Prospects: The Atlantic Low

April 21, 2 PM Update: As of 2 pm EDT, the National Hurricane Center has lowered the chances for tropical development from this system to 10%.

Weather Underground's Dr. Jeff Masters agrees that the likelihood of development is low.

Original post:
Nearly 6 weeks before the traditional June 1 opening of tropical season in the Atlantic, the National Hurricane Center this afternoon issued a "Special Tropical Weather Outlook" for a low pressure area northeast of Puerto Rico:

A LOW PRESSURE AREA LOCATED ABOUT 460 MILES NORTHEAST OF SAN JUAN
PUERTO RICO HAS DEVELOPED SOME SHOWER AND THUNDERSTORM ACTIVITY
NEAR ITS CENTER.  IN ADDITION...SATELLITE DATA AND SHIP REPORTS
INDICATE GALE-FORCE WINDS ARE OCCURRING NORTH OF THE CENTER.  SLOW
DEVELOPMENT OF THIS SYSTEM IS POSSIBLE DURING THE COUPLE OF DAYS AS
IT MOVES WEST-NORTHWESTWARD AT ABOUT 10 MPH.  THERE IS A LOW
CHANCE...20 PERCENT...OF THIS SYSTEM DEVELOPING INTO A SUBTROPICAL
OR TROPICAL CYCLONE BEFORE CONDITIONS BECOME LESS FAVORABLE IN
ABOUT 48 HOURS.  ADDITIONAL INFORMATION ON THIS LOW CAN BE FOUND IN
HIGH SEAS FORECASTS ISSUED BY THE NHC/TROPICAL ANALYSIS AND
FORECAST BRANCH...UNDER AWIPS HEADER NFDHSFAT2 AND WMO HEADER
FZNT02 KNHC.  ANOTHER SPECIAL OUTLOOK WILL BE ISSUED ON THURSDAY...
OR SOONER IF NECESSARY. 

The NASA visible satellite image (click to enlarge) shows the storm at 17:45 UTC (1:45 pm EDT) today. The center of circulation is west of the largest area of clouds.

There has only been one named storm (or equivalent in the pre-naming era) in April since Atlantic tropical cyclone records began in 1851. That was Ana, which formed on April 18, 2003. There was one tropical cyclone in February 1952 and one in March 1908.

TWC Reports April Tornado Record

For an update on the April tornado record, see:
Record Heat Fuels Historic Tornado Outbreak

The Weather Channel's severe storm expert Dr. Greg Forbes is reporting that the preliminary total of 272 tornadoes through yesterday breaks the April record of 267 in 1974. The average number of April tornadoes is 163.

The graph (click to enlarge) from the National Weather Service's Storm Prediction Center shows the cumulative annual total of 671 tornadoes to date outpacing the 2008 count of 631.

Record Late Snowfall in Green Bay

April 20 Update: The final daily snowfall total for Green Bay was 9.9".

For the ICE AGERS: Some temperature context for this event:

Despite the unseasonable cold of the last few days, the month of April so far has been within 0.7° of the long-term average in Green Bay. On the other hand, the month-to-date precipitation of 3.92" is slightly under 2.5 times the average amount. The season-to-date total of 7.00" is also almost double the average.

Here are some other month-to-date temperature departures from around the rest of Wisconsin:

Oshkosh    +1.5
Wausau     -0.6
La Crosse  +1.8
Madison    +2.6
Marquette  +1.6
Milwaukee  +0.5   

These daily snowfall records for April 19 were also set:

 CITY           SNOWFALL(IN)     OLD RECORD(IN)     YEAR

GREEN BAY(NWS)     9.9               1.5            1898
APPLETON           9.4               0.5            1924...1928
WISCONSIN RAPIDS   6.0               0.5            1982
STURGEON BAY       5.0               2.0            1925...1993
OSHKOSH            4.6               0.2            1953
STEVENS POINT      4.0               T              1914...1922
WAUSAU             1.9               1.5            1898
MERRILL            0.9               0.8            1928  

The top 5 seasonal snowfall totals at Green Bay are:

RANK    SNOWFALL       YEARS
1       147.7 INCHES   1887/88
2       103.6 INCHES   1889/90
3        92.4 INCHES   2010/11 [through April 19]
4        87.7 INCHES   2008/09
5        87.4 INCHES   2007/08  

Original post:
The National Weather Service reports that today's snowfall at Green Bay, Wisconsin has set a record for so late in the season:

AS OF 9 PM THIS EVENING...8.7 INCHES OF SNOW HAD FALLEN IN GREEN BAY.

THIS IS THE GREATEST DAILY SNOWFALL EVER SO LATE IN THE SEASON.

TODAY`S SNOWFALL BRINGS THE SEASONAL TOTAL TO 91.2 INCHES...WHICH
IS THE THIRD GREATEST SEASONAL TOTAL EVER IN GREEN BAY...AND THE
MOST SINCE THE WINTER OF 1889-1890.  

This exceeds by half an inch the 8.2" which fell 4 days later in the month on April 23, 1910. Measurable snow has fallen as late as May 28, when 3" fell in 1947 at Green Bay.

Daily records were also set or tied at Milwaukee and Madison:

A RECORD SNOWFALL OF A TRACE WAS SET AT MILWAUKEE WI ON APRIL 19.
THIS TIES THE OLD RECORD OF A TRACE SET IN 1990.

A RECORD PRECIPITATION OF 1.04 INCHES WAS SET IN MADISON ON
APRIL 19.  THE PREVIOUS RECORD WAS 0.93 INCHES IN 1993.

A RECORD SNOWFALL OF 1.3 INCHES WAS SET IN MADISON ON APRIL 19.
THE PREVIOUS SNOWFALL RECORD OF 0.3 INCHES WAS SET IN 1953.  

Happy Anniversary, BP Oil Disaster!

This morning's Diane Rehm Show marked the one-year anniversary tomorrow of the BP oil spill disaster in the Gulf of Mexico (audio here). Guests were:

• Joel Achenbach: reporter, The Washington Post; writer for Achenblog; author of "A Hole at the Bottom of the Sea: The Race to Kill the BP Oil Gusher."
• Frances Beinecke: president, Natural Resources Defense Council; former member of the National Oil Spill Commission.
• Randall Luthi: president of the National Ocean Industries Association and former director of the Minerals Management Service.

Luthi repeatedly praised the beneficial effects of the disaster as a learning experience for the industry. Investigative reporter Greg Palast suggests the industry may be somewhat learning impaired:
BP's Secret Deepwater Blowout