JasonOH

There's a big time flash flood threat behind this supercell.  It's dumping a ton of rain and more storms are popping along the OFB behind it and training along the path.  I expect some really bad flooding to occur tonight.

Looks like it will go south of Hattiesburg.  Looks to end up very close to Camp Shelby.

Tylertown storm is really improving its presentation.  Hook is becoming evident and the inbounds (outflow) are ramping up like the outbounds (inflow) have been the last few scans

Leesville, LA got a TDS. 

2 minutes ago, Moderately Unstable said:

Can someone take a look at the storm near Lennox GA and tell me what they think? VAX is showing a TVS but it is far from the radar site. 

I don't think that's surface based so there shouldn't be a huge tornado threat from it

I'm betting it lofted a bunch of leaves. Plenty of trees in that area and leaves are super easy to lift high.

TDS very evident on the LA cell.

Cell in LA also produced.  Quite the CC drop on it

Bit of a CC drop on the Texas storm. Spotter confirmed tornado.

Already a large area with greater than 2500 J/Kg of MLCAPE south of the warm front.  Definitely a volatile environment if surface winds are not veered and storms can form.

I have a feeling the HRRR is really overdoing they mixing of the boundary layer. There is not any other model support for mixing of that strength and I find it pretty hard to believe it will happen with the quality of moisture. Some mixing will happen, but not as much as the HRRR is modeling.

55 minutes ago, StormySquares said:

In this environment, any storms should be spinning but the lack of UH tracks in interesting. 

Sometimes that’s a sign that the storms are modeled to be elevated, similar to a lot of the crapvection last week. WAA loves to force elevated convection if there is a layer that supports it.

25 minutes ago, StormySquares said:

How do you find/use the DAT for NWS Jackson?

This link will work for any office. 
https://www.weather.gov/jan/dat_redirect

TDLR: Officially prelim 190 mph on the EF4 and 150mph on the EF3. More detailed info tomorrow. Adjustments are possible over the coming weeks.

4 minutes ago, Bob's Burgers said:

2.25 miles wide 

That puts it as the third widest on record behind El Reno 2013 (2.6 miles wide) and Hallam, NE (2.5 miles wide).

This was the strongest tornado since Rochelle in 2015. 

Up to 190mph and 3960 yards based on the viewer.

Reverse image search yielded nothing on that tree damage pic. I think we can say it’s likely legit.

Walthall county tornado rated 170mph EF4.

I wonder if they can only do the lower bound of DOD10 without a review to determine the actual wind speed. 
 

More info from a friend: EF4 and above and they typically need to call in a Special team to make the final determination. That would explain the lower bound usage and why it’s being checked again.

From the damage assessment toolkit. Bassfield EF4 was 2 miles wide

Great twitter thread about the NWS warning process for at embedded supercell that produced the crazy radar imagery last night in SC. 
 

Since I was confused earlier here is a tweet with the tracks

Bassfield is a prelim EF4. The trailing tornado is prelim EF3.  (Thanks to Andy for the correction. I got my counties all messed up)
 

Tweet about the house that slid. Looks like it was unanchored on cinder blocks.