April 27, 2011 Part 2: Forecast Accuracy

As we reflect on such a historic day we should thank the people from the Storm Prediction Center, National Weather Service, and local TV station meteorologists for forecasting this event days ahead.  This event was forecast very well from all these people and myself included.  The Storm Prediction Center highlighted the areas that were heavily impacted by this event 5 days prior to the event.  

The purple area remained highlighted with a Moderate Risk on Day 3 with an exceptionally high percentage of severe weather risk for a Day 3 Moderate Risk outlook.  The 45% purple shaded area is the area where the Moderate Risk was highlighted.

On the day of the event, a High Risk was issued as of 1:00 AM CDT (0600Z) with a high 30% chance of tornadoes over northern Alabama.  This time is close to the first round of storms that hit the area, but these were not the worst.  As the day progressed the atmosphere became highly unstable and favorable for a major outbreak as already highlighted that morning.  At 11:30 AM CDT (1630Z), Storm Prediction Center had a High Risk with a 30% chance of tornadoes and embedded in the High Risk was a small area of 45% chance of tornadoes.  Shortly before Storm Prediction Center updated the risk they issued a Particularly Dangerous Situation (PDS) Tornado Watch for all of Mississippi except for extreme southern counties.  This will be compared to my forecast for 1:00 PM CDT (1800Z) that I made on that day before the event began to unfold and what verified.

At the time I was forecasting the areas that will likely be hit the hardest, Storm Prediction Center issued a PDS for most of Alabama except for southeastern portions and extreme southwestern portions of the state.  What was most shocking for me is that when the Storm Prediction Center issued this I just finished highlighting a High Risk with the likely hood of a PDS Tornado Watch for central and northern Alabama and central Tennessee.  After I have posted my forecast, the Storm Prediction Center updated their severe weather outlook at 3:00 PM CDT (2000Z).  The High Risk with the high probability of tornadoes stayed over the same location.  Following the update, they issued a PDS Tornado Watch for central and eastern Tennessee.  I will compare the Storm Prediction Center's 2000Z severe weather outlook with my 4:00 PM CDT (2100Z) outlook and what verified.  

The last severe weather outlook for April 27, 2011 that Storm Prediction Center issued was at 8:00 PM CDT (0100Z).  The High Risk area has now been shifted over to northeastern Alabama and extreme northwest Georgia with a 30% chance of tornadoes.  My forecast was for 7:00 PM CDT (0000Z) with a High Risk bigger than the Storm Prediction Center had and over the same general areas, but included western portions of South Carolina and North Carolina and a small portion of southeast Tennessee where Chattanooga is.  Here is a comparison between the two with a verification.  

When I highlighted the High Risk area for my forecast I anticipated another PDS Tornado Watch to be issued.  Scary enough, about 6 hours and 10 minutes after I have posted my forecast, the Storm Prediction Center issued a PDS Tornado Watch at 6:50 PM CDT which is just 10 minutes before the time I forecast it would show up.

After the 27th, tornadoes kept on developing in The Carolinas up into the New England area, but were much weaker than what was experienced in Mississippi, Alabama, and Georgia.

It was horrifying to see how much the forecast models agreed that this day, one year ago, all the ingredients were going to come together for a tremendous outbreak.  It was scary to me when forecasting for this event and realizing how bad it will be, but I am proud of how well I was able to forecast for this event.  We should all be proud with such great lead time there was to warn the public because it could have been worse.  God bless all of those who were affected by this event.

April 27, 2011 Part 1: Unforgotten Memories

It has been one full year since this event happened and since we saw James Spann in a way we haven't seen him before.  April 27, 2011 is a day that no one in the Southeast will ever forget with all that was lost and with all of the unity that happened afterwards with people helping each other out.  Homes and businesses were demolished beyond recognition, lives were lost and forever changed, possessions and dreams were lost and crushed.  After a span of one year the pieces of peoples lives are still in the process of being picked up, but so much has been accomplished since that day last year.  Clouds and even the chance of some showers scatter themselves over the Southeast, but no signs or chances of anything severe to stop the clean-up.

The National Weather Service for 16 offices, Shreveport, LA; Jackson, MS; Memphis, TN; Mobile, AL; Birmingham, AL; Huntsville, AL; Nashville, TN; Morristown, TN; Peachtree City, GA; Wilmington, OH; Greenville-Spartanburg, SC; Blacksburg, VA; Louisville, KY; Wakefield, VA; Baltimore-Washington; and State College, PA, commemorate this day in history on how it affected each one of them.  Here is a map of all the tornadoes that touched down in Alabama.   

Here is another image of a wider view of the Southeast region with all the tornado touchdowns.  

This is something not only the people who were affected by this will remember, but our planet will remember for a while as the tornadoes left what are known as tornado scars on the ground.  

This is an image that shows the damage path with regards to vegetation.  Where you see area's of aqua are areas of no vegetation.  It is clear to see the tornado paths of the EF-4 that went between Jasper and Cordova (top tornado path), the EF-4 Tuscaloosa and Birmingham tornado (middle tornado path), and the EF-3 that went through Sawyerville and Eoline (bottom tornado path).

City Forecast Discussion: Lincoln, NE

Does this look familiar NCAA football fans?  The Division 1 Cornhusker fans sure do recognize this because this is their Memorial Stadium with the Tom Osborne Field and a "Sea of Red".  Located in the Great Plains city of Lincoln, the capital of Nebraska.  A stadium that holds over 80,000 people located in a city with a population over 258,000, over 7% of Nebraska's total population, creates a big attraction towards football fans and severe weather?  Yep!  Lincoln is in Tornado Alley and is not unfamiliar to severe weather and tornadoes.  The challenge lays in forecasting the weather for Lincoln to warn the public about events like these.  Lincoln is quite familiar with extreme heat and cold being in the Great Plains.  However, neither were a problem during the forecasting period as high temperatures only reached around 80 a few times.  The 60's was a comfort zone for the highs as more than half of the days reach a high in the 60's.  The lows had as much of a wide spread as the highs did where one day it hit 38 degrees.  Most of the time it liked to linger around 50.  The best way to describe each day by winds is "windy".  The lowest wind that was dealt with was 16 mph while the highest was 27 mph.  So the winds like to stay around 20 mph which is never good if you just got your hair done and want it to stay perfect.  The precipitation for the area is one of those things where you just want to say "forget about it" because models can forecast for rain to fall and not even a drop will fall at the Lincoln Airport.  This happened twice during the forecast period and it rained all around the airport, but not on it.

So, forecasting for a specific point in Lincoln, Nebraska is a hard challenge given the wide range in temperatures, varying winds, and precipitation that may or may not fall at your location, but maybe a mile down the road.  With that said, that leads me to the final city which is a tournament city for The Weather Challenge competition.  This city has a similar name to the largest city in Kansas, but is located in The Lone Star State next to the Red River.  Named after a five-foot waterfall on a river that was in the city, before being destroyed by a flood in 1886, and has had two devastating tornadoes, one in 1964 and the other in 1979.  Can you guess this Choctaw Indian settlement?

A Blast In The Past of Easter Sunday

Easter Sunday is a joyous day to celebrate with your family and your church with Easter egg hunts and Easter dinners.


Easter has a fascinating history not only religiously, but also meteorologically.  The weather always plays a part in every holiday where people get together for celebrations.  Today has been fairly inactive in the weather except around Anderson County, TX where hail was reported, but for the most part it has been a great day to be outside.  It hasn't always been that way though.  There has been a number of tornado outbreaks during the past years of Easter as well as tropical systems and winter weather events.  One of the earliest found tornado events that occurred on Easter was the Easter Weekend 1913 Tornado Outbreak Sequence that began March 20th and ended March 24th.  In 1913, Easter landed on March 23rd.  The number of deaths and injuries have mixed results depending on where you look, but what is known is that two deadly tornadoes did occur.  One hit Omaha, Nebraska and another hit Terre Haute, Indiana.  Both occurred on Easter Sunday.  The most devastating of the two was the Omaha tornado that was rated an F4 where about 150 people perished and hundreds more were injured.  What made matters worse was a passing cold front that brought snow to the area after the tornado passed through.  The same storm that created the tornado later started a huge dust storm that overwhelmed Topeka, Kansas.  The Terre Haute tornado happened later that night causing about 50 deaths.  To give you an idea on what the tornado looked like that devastated Omaha, here is an image: .
On April 21, 1957, there was an Easter Sunday outbreak of tornadoes that became known as the 1957 Lubbock Tornado Outbreak that spawned an unknown number of tornadoes, but some of these tornadoes were fairly large.  Not much information, if any, are known on how strong these tornadoes were partly because they traveled through rural areas where few people lived.  Luckily, there were no fatalities and the number of injuries were low.  Little was known on this event to the public until a guy named Jonathan D. Finch did a case study on this event with great details on the tornadoes and the atmospheric setup.  He shows how unique this event was because unlike most tornadoes traveling from southwest to northeast, these tornadoes traveled from southeast to northwest.  Here is an image of one of the tornadoes on his case study website from a newspaper article:

In 2006, there was yet another Easter tornado outbreak known as the Easter Week 2006 Tornado Outbreak Sequence.  This event started on April 13th and ended April 18th dropping 54 tornadoes, the strongest being an F2.  On Easter Sunday, which was April 16th, there were 14 determined tornadoes, 2 of which were F2, 3 were F1, and the remaining 9 were F0.  Throughout the whole event, there was only 1 fatality, but none occurred on Easter.
The most recent tornado outbreak that occurred during Easter was the April 19-24, 2011 Tornado Outbreak Sequence where at least 89 tornadoes were confirmed and the strongest of them was an EF4.  The last day of the event, April 24th, was Easter Sunday and only 11 tornadoes occurred on that day.  The strongest on Easter was an EF1 that caused some damage in Arkansas.  There were no fatalities during this entire event.

So far Easter seems to be the holiday where tornadoes love to interrupt.  However, there are other memorable weather events that have occurred on Easter that are not as devastating as tornadoes are.  Winter likes to make an entrance sometimes on Easter and one of those events was way back in 1929 when there was a large amount of snow that fell in the Midwest region of the U.S.  Not many other snowy or rainy weather events have been recorded on Easter, but the National Weather Service of La Crosse, Wisconsin was generous enough to post a number of Easter weather events that involved their coverage area.  If you would like to view more of these events here is the link: http://www.crh.noaa.gov/news/display_cmsstory.php?wfo=arx&storyid=8052&source=0.

There is another force of nature that has shown up a few times around Easter and that is tropical systems.  Looking as far back as 1846, there were 3 tropical systems that developed on Easter Sunday.  One of them were uncertain because of it being in 1846 and little knowledge was known about tropical cyclones, but there is belief that one made landfall in the Southern Mississippi Valley creating a lot of flooding.  During the 1973 Atlantic Hurricane Season there was a tropical depression that developed on Easter Sunday on April 22nd that created no threat as far as recorded history goes.  Finally, during the 2003 Atlantic Hurricane Season there was Subtropical Storm Ana that developed on Easter Sunday April 20th.  It later made landfall in Bermuda followed by Florida where only 2 fatalities were reported that were caused from the subtropical storm.

Compelling weather history for Easter isn't it?  Easter is a unique holiday in the first place because it doesn't occur on the same numbered day as other holidays like Christmas or Thanksgiving.  It is always in March or April on a Sunday, but the number of the day changes every year.  Another interesting fact pertaining to Easter is the island that these guys have been resting on for thousands of years.

That's right!  Easter Island Heads or their correct name "moai".  The island that these famous statues have been sitting on was named Easter Island because a Dutch explorer named Jacob Roggeveen encountered this island on Easter Sunday in 1722 which was on April 5th.

Happy Easter everyone!!!

City Forecast Discussion: Hilo, Hawaii

Ain't this a beautiful sight.  Blue ocean, mountains in the background, and a gorgeous coast line in the tropics. Hilo is a spectacular vacation location that has a nearly predictable temperature due to it's tropical location.  Rain is a common appearance as well as breezy conditions.  So what were some of the forecast challenges?  One thing that wasn't much of a challenge was the high and low.  For the two weeks forecasting for Hilo the high ranged from 76 F to 81 F and the low ranged from 62 F to 67 F.  Small range in temperature so being a degree or two off is fairly common.  The wind was just slightly more challenging than the temperature because depending on which direction it came from it could be as strong as over 25 mph sustained or as low as 10 mph.  If it came from a northerly direction it would be coming off the ocean and most likely be breezy, but if it were to be more from the land then it could be light because of surface friction from the trees and buildings.  The challenging part for Hilo was the precipitation.  Being in a tropical location you would expect at least a little bit of rain every day with some days having a lot of it and that is true, but it is all location dependent.  The precise location that was being forecast for was the western side of the Hilo International Airport.  So, if it rained on the eastern side of the airport or on the western portion of Hilo then it doesn't count toward the contest.  The other important factor to keep in mind, other than location, is the amount of precipitation.  It could be a light shower and get just a tiny bit of rain or a thunderstorm and get over an inch.  As a matter of fact, Hawaii experienced its largest hailstone during this time period of forecasting for Hilo when Oahu experienced a storm that dropped grapefruit-size hail that measured up to 4.25 inches long.  Check out how big this thing was: 

The next location is far from the tropics and is in the great Tornado Alley.  This "Star City" is home to a large group of huskers and was originally named Lancaster, but was changed due to the assassination of the 16th president of the U.S.  Think real hard.