March 22-23 Severe Weather Update

23 03 2013

We pretty much have the forecast wrapped up as all the models are agreeing with pretty much everything. We will first start off with the overall setup of where the low will wind up moving.

Right now the surface low is sitting near Houston, TX. SPC has a warm/stationary front along the Gulf Coast. There is a strong temperature gradient in Central Mississippi and Alabama which is where the low pressure will move along. The low pressure should enter Southwest Mississippi late this evening around 10PM and slowly move into West Central Alabama near 2AM Sunday morning. The low should strengthen some and make its way into Central Tennessee near 8AM. At this time it will hang out in Tennessee for a little bit and strengthen the cold front which will start sweeping through Alabama near 4PM tomorrow. The cold front should pass through Alabama by 10PM tomorrow night.

Now time for the setup of the threats. Right now, there is a tornado watch in Central Mississippi and a severe thunderstorm watch in North Mississippi stretching into Southeast Arkansas and Northeast Louisiana. This makes perfect sense with the current forecast track of the low. As the low makes its movement to the Northeast it will bring with it warm, moist, unstable air along the coast which would be favorable for severe thunderstorms that could produce hail, some possibly large, and damaging winds, but about a mile above us in the atmosphere is a key wind called Low Level Jet that is very weak until tonight when it usually strengthens. Here is the situation with that though, the area where the Low Level Jet or LLJ strengthens will be north of where the rich, unstable air is. The LLJ is a key component for tornadoes to develop as long as everything else is there for the storms. So southern Mississippi and Alabama will have the unstable air while northern Alabama will have the LLJ and a component we call shear which is a difference in wind speed and direction in the atmosphere. This leaves Central Alabama and Central Mississippi which will likely have a mix of the two which is where the main focus is. Now this isn’t to say that southern Alabama and northern Alabama are in the clear as mentioned earlier.

Finally to the threats and the areas. The biggest threats at first will be damaging wind and hail through the rest of today. Once when the LLJ kicks in that will increase the threat of tornadoes. The area for the threat of damaging wind and hail will be our entire viewing area and as the night goes on into the morning the threat of tornadoes shows up for Central Alabama all the way down to the Florida/Alabama state line. Parts of Northern Alabama have a chance as well, but it is lower than the rest of Alabama. This threat does stretch into western Georgia. The timing of all of this is hard to tell, but the tornado threat will be after midnight.





Weekend Severe Weather Discussion

22 03 2013

We are looking at another severe weather event for this weekend and the tricky part has been figuring out what the biggest threats will be and when they will occur.  We have been looking at 3 main forecast models and they all tend to tie together for the big picture, but it’s the small important details that makes this so hard.  Here is what the Storm Prediction Center has for tomorrow:

SPC has the main focus over most of Alabama and Mississippi with the highest risk of 30% chance of severe weather in the southern half of Alabama and Mississippi.  Here is the problem with this though, the forecast models are showing something a little different.  Here is what we are more thinking the biggest threat will be:

March23_24SVRArea

This area seems to be more favorable as the more recent forecast model runs are wanting to push the warm front further north than what was expected.  Why is that important?  Where the warm front is helps point out the area of interest where tornadoes are likely to be spotted because they typically like to develop there due to the dramatic change in wind direction as you go higher in the atmosphere.  The area highlighted is the area where most of all the ingredients for severe weather line up.  This includes a lot of complicated stuff, but what it ultimately results in is the region where we could see rotating storm capable of producing tornadoes, strong damaging winds and even large hail.  This isn’t to say that south of this area won’t get anything because that area has other factors that could help in developing some severe storms as well.

So to sum it all up we are looking at an event that could start out as a wind and hail event as it is moving towards us until the cold front catches up to the warm front which will develop a squall line.  As this starts to happen rotating storms are likely to develop.  There has been talk of whether some discrete storms will develop and rotate, but as of right now we are not seeing that to happen because a specific feature in the atmosphere that we look for is very weak to cause storms to rotate.

The timing looks to be late Saturday night when things start cooking, but brought to a boil by after midnight Saturday when all of the features we look for to create severe weather line up.  By this time it looks like it will be in the eastern half of Alabama into Georgia.

Since the forecast models are having a hard time with all of this even with it being just tomorrow we are still watching it all to see what changes might happen as the environment will be very delicate and only the slightest change can make it worse or not even happen.

StormTEAM 4/Gamma 9 Senior Meteorologist Michael Vasquez

 





Blizzard of 1993: 20 Year Anniversary

13 03 2013

It’s hard to believe that it has been 20 years ago since we had the infamous Blizzard of 93′  that received a number of names such as Storm of the Century and 93′ Superstorm.  It’s wrath lasted from March 12 to March 15 dropping snow in the Southeast, tornadoes in Florida, and feet of snow along the Atlantic Coastline.  Some basic, but interesting facts about the storm:

The highest amount of snow recorded during it’s like was 69 inches or 5 ft and 9 inches in Mt. La Conte, TN.  Its lowest pressure recorded was a 960 millibar low.
Coldest temperature reported was -12 degrees Fahrenheit.
It caused $6.65 million in damage according to 2008 U.S. currency.
There were 310 people who parished from this storm.

We are going to focus on the impacts in our viewing area.  To start it off, here is an image of the snowfall accumulation from the storm in it’s entirity.

It’s always amazing to see that as far as the coastline of Alabama, Florida Panhandle, and Mississippi saw 1-4 inches from this storm and much more further north.  But how much snow really fell?  We found some measurements for how much snow was on the ground specific locations which will vary from where all of you viewers lived, but this is what we were able to pull up:

Alexander City: 7 in.
Auburn Agronomy Farm: 5 in.
Opelika: 4 in.
Wetumpka: 6 in.
Montgomery Airport: 4 in.
Selma: 4.5 in.
near Union Springs: 4 in.
Troy: 4 in.
North Brewton: 3 in.
Chatom: 5 in.
Atmore: 2 in.
Hurtsboro: 3 in.
Mobile Regional: 3 in.
Bay Minette: 3 in.
Robertsdale: 2 in.
Columbus, GA: 1 in.

If you lived in Birmingham then you saw 17 in. of snow with snow drifts much higher than that.

The snow is always fun, but as mentioned before there were several fatalities.  Of those fatalities, 16 of them were in Alabama, 15 were in Georgia, and Florida had 44.

This was a powerful storm and so far we have not seen anything like it.  Could we see something similar in the future?   Very likely.  When?  We don’t know.  What we will always remember from that day is the setup that led to such an event and one picture will be always been meteorologists memories which will help us find it again when something similar happens again.  The famous picture is here:

Blizzard93





Comet PanSTARRS

12 03 2013

Tonight and this week will be a great time to look for Comet PanSTARRS across Central & South Alabama as we will have clear skies as the sunsets. To look for the comet, just look to the western horizon around 30-45 minutes after sunset. You will only be  able to see the comet for about 15 minutes after sunset so have your spot picked out ahead of time.

Sunset time for Columbus, GA/Phenix City, AL (Eastern Time)

Panstarrs Sunset CSG

Sunset time for Mobile, AL (Central Time)

Panstarrs Sunset Mobile

Where To Look

PanSTARRS_finder_large_thumb

 

 

 

 

 

 

 

To look for the comet, just look to the west about 10-20°above the horizon and very close to the crescent moon. It’s not going to be as bright as Hale-Bopp in the late 90s, but you will be able to see it with your naked eye & binoculars. PanSTARRS will look like a bright fuzzy star and will have the same brightness magnitude as a star in the big dipper.

A good way to gauge the distance above the horizon is to use a closed fist at arms length from you as seen below.Panstarrs Hand

The forecast for Tuesday night through Friday night should be good to see Comet PanSTARRS as we will see mostly clear skies at the time around sunset for Mobile, Montgomery, & Columbus/Phenix City

Good luck on viewing the comet and if you get any good pics, we would love to see them!

-StormTEAM 4 / Gamma 9 Weather Chief Meteorologist Patrick Bigbie