Tuesday, March 22, 2016

Thursday Update

Well as I had mentioned earlier the SPC has most all of Central and North Alabama in a SLIGHT RISK for severe weather on Thursday.
The main threat will come in the for of damaging straight line winds as the squall line progresses eastward as well as a small tornado threat with cells that may form out ahead of the main line. While this mornings runs had very little in the way of CAPE the 18z NAM has really ramped up the cape showing 2000 jules at 4pm in west Alabama.
While I am not expecting a major tornado event a few tornadoes are possible. Here is the STP valid 4pm
There will be more than enough Helicity to support rotating updrafts that may develop. With that being said we could also be looking and some decent hail in the stronger storms.
This looks to be a daytime event and that could be concerning as it looks to hit during the best daytime heating. The time frame I am going with is 11am-9pm.. The one thing that may throw a wrench in this whole thing is this
The NAM is showing some rain showers developing early Thursday morning. If this happens it may stabilize the atmosphere enough to lessen our severe chances that afternoon. This is developing and I will post more tomorrow evening as we get closer to the event

Monday, February 22, 2016

Tuesday Update....

Ok folks we are just about 24 hours before the severe threat could begin to show its face across Alabama. Currently the SPC has areas south of I-20 in an enhanced risk for severe weather on Tuesday with a moderate risk to the South of Highway 80.
The NWS in Birmingham has issued its own graphic cast showing an elevated risk as well as estimated timing up into central Alabama
The surface low is supported by a deep trough, (and can be clearly can be seen in this output) Bulk shear values (0-6 km) nearing 100 knots, a low level jet (5,000 feet) over 60 knots.
With the SB cape values backed off a bit up into central Alabama and be more concentrated to South Alabama. As well as the STP values remain to be high in South ALabama
Now here is my thinking on locations of the severe weather
Now as far as timing while the NWS has it beginning as early as 4pm I feel the greater threat will come after 6pm. One thing that needs to be watched carefully is the flooding threat. Some places could see upwards of 3-4 inches of rainfall by the time it is all over. Take the time now to prepare yourself. Have a way to receive weather alerts if warnings are issued, have a plan in place, have a helmet to put on in case of a tornado hitting your home. Make sure you have a good flashlight in case of power outages. And make sure that when you go into your safe place that you have on regular shoes not flip flops or sandals..

Sunday, February 21, 2016

Tuesday Severe Threat?????

The buzz all weekend has been if we will see severe weather on Tuesday. Well as of 6pm models are getting into more agreement so some type of severe weather looks likely. Currently the SPC has the lower 2/3 of Alabama in a the standard Slight Risk for severe weather on Tuesday.
I feel the risk area will be shifted more to the north over the next 24-48 hours. based off what I am seeing. Right now all modes of severe weather are possible but currently the greatest risk for tornadoes in my opinion looks to be down on the gulf coast including Biloxi Ms, New Orleans La, Mobile Al, and Pensacola Fl. Here are a few models for Tuesday all valid at 6pm. STP
0-3km SRH
SB Cape
Notice all the higher values are along the coastal areas. Yes there will be enough instability across portions of central Alabama that we may see severe thunderstorms. Main 12 hour window looks to be from 6pm Tuesday-6am Wednesday. Stay tuned for later updates as we get closer and can nail down the exact impact locations a bit better. For those across Central and West Alabama keep up to date by following WVUA23 Chief Meteorologist Richard Scott on FB WVUA 23 Richard Scott or if you are in Southwest Alabama or Northwest Florida you can tune into Spinks Megginson at rzweather.com (link on the right side of the blog)

Monday, February 1, 2016

Tuesday Update..

Ok folks now is the time to make sure you are prepared for severe weather. Make sure you have a way to receive weather alerts tomorrow. Make sure you have a plan in place if your area is placed under a tornado warning.Make sure you have a flashlight with good batteries, make sure to have a helmet to help protect your head. The SPC has not changed the their thinking on the current outlook which now has all of NW Alabama in an enhanced risk tomorrow evening. Areas along I-20 to I-65 to the Northwest seem to be under the biggest threat.
I have been in contact with local Chief Meteorologist Richard Scott over at WVUA23 discussing timing and strength of the system. Like I mentioned this morning it is hard to overlook the short range mesoscale models when it comes to severe weather and the NAM is still hinting at SB Cape values around 750 j/kg
and the GFS is around 500 j/kg. EHI values are almost 2 which is not real high but it only needs to be at 1 for severe weather. Whats problematic is the bulk shear that looks to be 60-65 knots
and the 0-3km SRH is extremely high and more than sufficient to support rotating updrafts
The Significant Tornado Parameter is not overwhelming but high enough to bare watching
Here is a timeline from Chief Meteorologist Richard Scott on when you can expect the storms in your area.
Remember the lines you see here as far as the outlooks and timelines are just that LINES. Storms do not know these colors and storms are expected almost anywhere across Alabama tomorrow night just the higher chance in my opinion will in NW Alabama and points to the NW
Stay tuned for any changes that may develop.

Sunday, January 31, 2016

Tuesday Update

Current SPC Outlook
Good morning everyone. I will not beat around the bush so I will dive right into things. Based off current data (the 06z runs) I feel the threat for some severe weather is still there for Alabama overnight Tuesday. The one thing is the overall tornado threat seems to be diminishing but not gone. Basically making the main threat for Alabama damaging straight line winds along the squall line. INSTABILITY: Temperatures will be in the lower 70s and dewpoints in the lower 60s. 3pm 2meter temps
Dew Points at 6pm
The GFS and NAM are only indicating about 250-500 j/kg of CAPE from 3 p.m. to midnight window. While yes this is more than enough to produce thunderstorm updrafts, but they won’t be intense. GFS SB CAPE VALUES at 6pm Tuesday
NAM CAPE VALUES at 6pm Tuesday
WIND SHEAR: The overall wind shear needed for organized thunderstorms will certainly not be lacking as bulk shear values will be over 60 knots. Low level helicity will be very high as well. The GFS and NAM rate it at over 400 m2/s2, which is almost too high. Bulk Shear
The Significant Tornado Parameter is greater than 1 over Central Mississippi at mid-afternoon and nearly 2 over northern Mississippi by sunset, but goes down as the sun sets.
The entire system is a bit slower than this time 2 days ago. With this happening now the main area of concern for significant tornadoes will be north Mississippi and western Tennessee as storms in these areas could be supercells and will be occurring during the prime heating of the day. With that in mind I have adjusted my threat map accordingly.

Saturday, January 30, 2016

Tuesday Severe Update Model Madness

Ok now that the mesoscale models are able to get into the mix we can start getting a better understanding on what we can expect next Tuesday. Right now per the Global models the system has slowed a bit and pulling back to the north and northwest with the greater dynamics. Looking at the GFS and other global models the trough seems to be slowing a bit and going more of a positive tilt which which helps lessen the threat of a major severe weather event. If you base the entire forecast off of the GFS model.
Now don't take that likely because the threat is still there and it is still real just a tad lesser than this time yesterday. Right now this morning this is looking like a High Shear Low CAPE type event with the GFS CAPE values around 500 j/kg and the EURO is putting out values about 750 j/kg which is high enough for severe storms to develop but could limit the overall strength of the storms (but they can still be extremely dangerous) Again if you base the forecast off of the GFS models. GFS CAPE Values at 6pm Tuesday
GFS SRH values at 6pm Tuesday
Now the mesoscale (NAM) is in and actually is able to go out thru 6pm Tuesday and here is what we see with that. CAPE Values at 6pm
Significant Tornado Parameter 6pm Tuesday
SRH 6pm Tuesday
Bulk Shear values are very impressive as well
With all that said all the dynamic and thermo dynamics profiles suggest severe weather. Even though the trends are a tad weaker than yesterday and based on what I am seeing I am adjusting my threat map just slightly to the NW
Also for those of you asking about a timeframe here is just and educated guess based on current speeds of the system from all models.. West Alabama 5-8pm Central Alabama 7-10pm East Alabama 9pm-2am Now remember there will be a few more adjustments to be made over the next couple of days as with each run there is the chance the trough digs into the area faster and the all the severe parameters increase or decrease each time. I will update as needed. Just be prepared by having a plan in place and make sure your NOAA WX Radio is working properly.