Snowflowxxl
Member
Yes
-
Hello, please take a minute to check out our awesome content, contributed by the wonderful members of our community. We hope you'll add your own thoughts and opinions by making a free account!
Severe March 2-4 Severe weather Threat
- Thread starter Arcc
- Start date
ForsythSnow
Moderator
Yeah I'm seeing that in the newer model runs. If it keeps it up we definitely will avoid the worst of it up here.
Snowflowxxl
Member
12z NAM is alarming!
snowlover91
Member
12z NAM keeps most of NC in the cooler side of things with a sharp boundary dividing the state.. meanwhile areas in GA, SC, AL and MS are in the low 70s so it could be rough down that way.
YIKES. THIS IS NOT A GOOD LOOK!!!!!
Here's the next frame. Ruh roh. Of course, the euro will show the cellular structure better than the lower res GFS... but this is running into a very warm airmass imo. can only lead to problems.
Regardless of shear/cape around the area in the midlevels, i can definitely see this being a potential strong wind threat for AL/GA/SC under the heavier showers. If some cells start going, 
Snowflowxxl
Member
Trend on the GFS is for less influence of the wedge in GA
That's not good.
That is the key to watch, does this event trend higher with instability like the last one did. Higher instability, some sort of cap and an decent EML is the only thing keeping this from a High risk IMO.
What is this I hear about along the edge of a wedge, amplification of thunder storms in a setup like this? I'm not very good with severe, outside the basics... is it more prone to storm development, more shear, even with weaker severe ingredients?
In this setup, it's the warm front than really a wedge. But yes, the warm front can cause convection, but it also backs surface winds and increasing low level helicity.
Going to be interesting to see how entrenched the wedge turns out to be and how quickly the southern and eastern portions erode. Along the boundary, there could definitely be a few spin-ups. This situation certainly looks concerning and bears watching closely, especially with respect to the wedging extent. As we know, wedges are usually a bit more stubborn than models indicate, especially when they're reinforced with moderate precipitation. The low tracking up the Apps (which is a bit unusual) and the lack of a favorably located damming high to the north make me think that this could be one of those times where the wedge erodes more quickly. We'll see if models trend that way.
ForsythSnow
Moderator
SPC day 4 has this at the moment.
Euro is slightly weaker with the PV and slightly west with the trough at 48hrs. Looks like the slowing/amping trend will continue.
Maybe not, very close to the same thing yesterdays 12z run showed.
Ron Burgundy
Member
Zero mention of possible severe by FFC in their AFD. Kind of weird given we are 72 hours out.
Snowflowxxl
Member
Euro not backing down!
Edit: After looking at it in more depth, wow. Upped parameters for much of GA and Alabama.
Edit: After looking at it in more depth, wow. Upped parameters for much of GA and Alabama.
Last edited:
If a stronger EML verifies and we get a less junky warm sector, so much more area is affected.
This is the NAM) I’d say so far atm lapses are pretty limiting along with a skinny CAPE sounding, that hodo is similar to last setups tho and strong shear/SRH, also that’s a pretty moist column, drying doesn’t occur until your near 500mb, this screams low cloud bases, anyways even with limiting low level lapses, 3CAPE is decent 
18z NAM has over 1000 j/kg cape values over S central MS into C AL Sunday afternoon. 0-1km SRH over 250 m2/s2 over AL...
STP increasing Sunday afternoon from previous runs.
Also low level jet ramping up over AL/MS compared to 6z/12z valid 18z Sunday.
STP increasing Sunday afternoon from previous runs.
Also low level jet ramping up over AL/MS compared to 6z/12z valid 18z Sunday.
What has me worried is short range guidance is probably gonna perk up instability more since they can detect more mesoscale/local stuff and boundaries and have way better resolution than globals
This sounding is near Birmingham Sunday after noon. SRH over 400, you have to be kidding me. The 18z NAM is also showing a more substantial EML building into southern AL than before. If that continues with this type of low amp wave, it's just gonna get nasty.
Attachments
Three things that could stop an outbreak.
1: too much junk convection slows warm front progression and instability stays too low.
2: Lack of EML contributes to #1 and poos laspe rates. Strong shear tears apart updrafts until front with wind being main threat.
3: SSW surface winds limit convergence and delay cell initiation. This allows upper level winds become parallel with the front and we end up with a squall line on the front.
1: too much junk convection slows warm front progression and instability stays too low.
2: Lack of EML contributes to #1 and poos laspe rates. Strong shear tears apart updrafts until front with wind being main threat.
3: SSW surface winds limit convergence and delay cell initiation. This allows upper level winds become parallel with the front and we end up with a squall line on the front.
Likely.
Basically squall line..lol?
No, just a likely chance something prevents an outbreak.
Snowflowxxl
Member
Always does seem to be one thing that prevents everything from coming together for a system to reach its full potential. Most of the time it seem's a bunch of junk convection in the morning last longer than normal and doesn't allow for the atmosphere to destabilize. The warm front also doesn't make it as for north as the models had anticipated.
THIS IS ON MY ROOFTOP
Snowflowxxl
Member
Last two events that were big in GA were 3/19/18 and 4/5/17. Both times saw the warm front really struggle to make it above the city. I will probably be monitoring that the closest from here on out. The GFS and ICON keep ATL around 55 most of the day, which would mean low chances.
Webberweather53
Meteorologist
There also seems to be a proverbial wall for severe weather and especially tornadoes that literally hugs the Alabama-Georgia state line (minus a few exceptions), which is probably explained by the presence of the Apps. 95%+ of the time GA gets sloppy seconds from Alabama and typically those storms already grew upscale or evolved into linear slop.
Ron Burgundy
Member
NWS has ATL at 63 Sunday. I’m all for 55 though.
Snowflowxxl
Member
Yea Georgia isn't really known much for Tornado Outbreaks. We saw some with the 4/27/11 system, but nothing like Alabama.
Webberweather53
Meteorologist