Thursday, October 16, 2014

Active Secondary Severe Weather Season



If it seems we have had a lot of severe weather over the past month, you're right.  Our primary severe weather season was almost non-existent with the obvious exception of the Mayflower/Vilonia tornado.  We all know it only takes one storm to cause devastation.  The cool and wet summer did bring storms and some of them reached severe limits.

As we are now rolling into fall and we always cation the secondary severe weather season can prove to be as active or even more active than spring.  The National Weather Service has almost completed their surveys from the Monday, October, 13th severe weather event.  They have found 7 tornadoes across the state.  If you account for the 3 tornadoes on October 2nd and 1 on September 17th, the majority of our tornadoes this year have all occurred within the past one month.  That's amazing!  

Are we finished with the severe weather?  No.  We are getting a much needed break which may last at least for the next 7 days.  We have the end of October, November, and into December to watch for a very active weather pattern.  I hope it calms down, but as I indicated on the blog several weeks ago, history says this may turn into an active secondary severe weather season and it has.

Check out these stats. below.


These are severe weather reports from the National Weather Service office in North Little Rock which covers most of the state.  January and February were quiet, then we saw some activity in March.  It really ramped up in April and a lot of that was from the 27th.  May was very calm, but June and July proved to be active.  The wet weather pattern helped to keep us from hitting 100 degrees.  Notice how we are only half way through October and the severe weather reports have really ramped up.  As a matter of fact, the Little Rock office has more severe weather reports this month than it did all of last April. Amazing!
As far as tornadoes are concerned. We had 7 in all of meteorological spring (March, April, and May).  We have had more in just the first 2 weeks of October!   Also, more than half of the tornadoes so far this year have all occurred within the past month. 

Sunday, October 12, 2014

Monday Severe Weather Update




6:40PM Sunday update... it appears the short term hi resolution models may be speeding up the arrival of rain and thunderstorm activity.  It could get into central Arkansas before sunrise...COULD.  This video goes over more model data plus some of my thoughts.








This video goes in depth with timing and severe threats late tonight into Monday.


Friday, October 10, 2014

Severe Weather Chances Increasing



October is becoming more active than spring, if you take out that one storm which produce the devastating Mayflower/Vilonia tornado.  For all of April and May, the North Little Rock National Weather Service office issued 119 severe thunderstorm warnings.  Just in the first few days of October, we're up to 39.  By Monday afternoon, we may not exceed 119, but we're going to inch higher.  The idea this would be an active severe weather season is unfortunately becoming a reality.

Heavy rain will be the main threat late Friday into Saturday as a slow moving cold front interacts with copious amounts of moisture including moisture from the Pacific hurricane, "Simon".  The front will settle across southern Arkansas Saturday allowing very cool air to filter into the state.  We're not getting out of the 50s and 60s for much of central and northern Arkansas.  By Sunday, the front will begin to move to the north in response to a developing storm system to our west.  While there will be a small chance for rain/storms Sunday, the best chance arrives Sunday night into Monday.  The timing of this can still change and that's going to play a key role as to the severity of the storms Monday.  If the storm is delayed and comes through Monday afternoon, that will only allow the instability levels to increase and the severe weather threat will be greater.  Even if it comes through during the morning, severe weather will be possible.

At this time, hail and wind will be a major concern.  Isolated tornadoes can't be ruled out, especially if any thunderstorm can develop ahead of the main line.  I can't stress this enough, this can still change and I urge you to keep checking back.

By Tuesday, we should begin a stretch of cool and dry weather.

Much of the model data below is courtesy of weatherbell.com

This is only 1 model, but let's see what it says.  By 4AM Monday, rain and storms will be ongoing across the north.  Watch the line of storms develop rapidly over Oklahoma, then push over to Arkansas.
By 7AM, you see the line crossing from OK into AR.  See those storms ahead of the main line?  Don't take this literally as each model run will change, but if any storm can develop ahead of the main line, the tornado threat will increase.  Also, if this system slows down, that only allows daytime heating to add fuel to the fire.
By 10AM, The line is marching east and affecting central Arkansas.  There are times when the line moves much faster than the models predict.
By 1PM, the line is getting ready to cross the MS River.
The Storm Prediction Center already shows a "Slight Risk" for severe weather later Sunday.
On Monday, much of the Channel 7 viewing area has a risk for some severe weather.  At this time the main threats will be wind and hail.  A tornado threat will increase, especially if any storms develop ahead of the main line.
Rainfall amounts will range between 3-5 inches or more over the next 5 days.