Archive Severe Weather 2019

[Kory]

What is the "COD" in this context?

Why are those particular MJO phases more favorable for severe weather in the CONUS?

Early April always seems to be tricky, anyway. You can get the occasional biggies (much like March and Beauregard), but you're just as likely if not more to see issues with moisture return (cold fronts too close together), meridional flow, etc. Look at 2017 - all those high risks and nothing anywhere near that significant. The first part of mid-April is only now getting into fantasy range of the GFS.

COD is known as the “circle of death” regarding the MJO strength. It is a weak phase of the MJO where other background forcing takes effect.

Those phases over Africa and Indian Ocean help poleward flux of heat (I believe), due to the enhanced convection associated with the MJO, which then forces changes in the jet stream and teleconnections such as the PNA/AO/etc. those phases tend to have Pac jet extensions into North America and large scale troughing that is centered in the West/Central U.S....a more favorable pattern for severe weather.

 

[CheeselandSkies]

Thanks, that is helpful. Maybe with any luck (for us chaser types), it will get into a more favorable phase timed just right with what should be peak season - later April into May.

 

[Weatherphreak]

Even fantasy land is looking iffy. April 12th system looked halfway decent on the gfs earlier but FV3 isn’t in agreement at all. May not see much rain in the Tennessee valley over the long term which I’m not complaining about but everything will be yellow in about a week.

 

[CheeselandSkies]

GFS has been hinting that things could pick up around the end of the first week/early part of the second week of April. Granted it is the GFS beyond 240 hours, but it's been pretty steady with that look since the period came into range.

 

[akt1985]

GFS has been hinting that things could pick up around the end of the first week/early part of the second week of April. Granted it is the GFS beyond 240 hours, but it's been pretty steady with that look since the period came into range.

I assume you are talking about the few thundershowers that are in the forecast over Alabama next Friday? I’m going down to Florida next Friday and I hope I don’t have to dodge severe storms.

 

[CheeselandSkies]

I assume you are talking about the few thundershowers that are in the forecast over Alabama next Friday? I’m going down to Florida next Friday and I hope I don’t have to dodge severe storms.

Not really. I was talking a little bit beyond that, and more looking for just a general pattern that looks more conducive for severe weather potential somewhere in the central/eastern US, whether it be the Plains, the Midwest or Dixie.

For example today's 12Z GFS run at 300 hours depicts a large area of >1,000 j/kg SBCAPE across much of TX/OK/KS/NE/AR/LA/MS in the warm sector of a 988 MB lee low. Obviously way too early to get excited or try to nail down storm mode or location of greatest threat beyond "somewhere in the central U.S," but if it persists with that general look in that general time frame and the EURO joins in, it's a good bet something is brewing for that time frame.

Far preferable in my mind than seeing both models locked on to the idea of cold air continuing to flow into the eastern U.S. for the foreseeable future, like they were at this time last year.

 

[bwalk]

Good defense and explanation of your original point, Cheese. You backed it up with some facts and evidence. Most importantly, you gave all of us some hope there could be some actual active weather to monitor, discuss and/or chase in the near future. Most of us are tired of this cold pattern.

 

[kivey2969]

Looks like we have a slight risk for parts of MS, TN, AL today. Anybody going to start a thread?

 

[Equus]

Hosting a campout and go under a 5% TOR. This happens rather often... but when hosting weekend campouts in AL in March or April I guess it's to be expected ahaha

 

[MichelleH]

Hosting a campout and go under a 5% TOR. This happens rather often... but when hosting weekend campouts in AL in March or April I guess it's to be expected ahaha

Interesting...that 5% wasn't there before the 11:25 AM Day 1 update. Seems the tornado threat has increased. Like you said though, it IS March in Alabama. LOL

 

[bwalk]

Wow. This confirmed tornado touched down in Colorado yesterday. The temperature was in the 30's & the dew point was also in the 30's!
I mean is this even possible?! I know the SVR dynamics are different West of the Mississippi River (dry lines, etc) but still. It seems close to impossible.

In fact, at 4pm, when the tornado was reported, both, the temp & the dew point were 32 degrees!



Source: https://gazette.com/news/funnel-clo...cle_268f0812-5270-11e9-a506-a74ea63fee0c.html

3/29/19/Co temps/dew points: (Denver for reference) https://www.wunderground.com/histor...istory/daily/us/co/denver/KDEN/date/2019-3-29

 

[Equus]

SPC saying cloud cover and meager low level moisture is hampering stuff so far, and given the only occasional breaks of sun between the showers here, I'm intrigued to see if there's enough instability to get stuff really going. Would be nice to not have damaging wind or hail as there are 7+ cars parked here in the woods, threatened by both.

Ok and as I say that we suddenly have full sun. Interesting.

 

[MikeAthensAl]

Wow. This confirmed tornado touched down in Colorado yesterday. The temperature was in the 30's & the dew point was also in the 30's!
I mean is this even possible?! I know the SVR dynamics are different West of the Mississippi River (dry lines, etc) but still. It seems close to impossible.

In fact, at 4pm, when the tornado was reported, both, the temp & the dew point were 32 degrees!

View attachment 1263

Source: https://gazette.com/news/funnel-clo...cle_268f0812-5270-11e9-a506-a74ea63fee0c.html

3/29/19/Co temps/dew points: (Denver for reference) https://www.wunderground.com/histor...istory/daily/us/co/denver/KDEN/date/2019-3-29

The dreaded snownado!

 

[akt1985]

Severe thunderstorms starting to pop over middle Tennessee.

 

[Timhsv]

ULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE NASHVILLE TN
618 PM CDT SAT MAR 30 2019

THE NATIONAL WEATHER SERVICE IN NASHVILLE HAS ISSUED A

* TORNADO WARNING FOR...
NORTHEASTERN ROBERTSON COUNTY IN MIDDLE TENNESSEE...

* UNTIL 645 PM CDT.

* AT 617 PM CDT, A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO
WAS LOCATED 7 MILES NORTHWEST OF CROSS PLAINS, OR 10 MILES
NORTHEAST OF SPRINGFIELD, MOVING EAST AT 55 MPH.

HAZARD...TORNADO.

SOURCE...RADAR INDICATED ROTATION.

 

[Timhsv]

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE NASHVILLE TN
632 PM CDT SAT MAR 30 2019

THE NATIONAL WEATHER SERVICE IN NASHVILLE HAS ISSUED A

* TORNADO WARNING FOR...
NORTHEASTERN MAURY COUNTY IN MIDDLE TENNESSEE...
SOUTHEASTERN WILLIAMSON COUNTY IN MIDDLE TENNESSEE...

* UNTIL 700 PM CDT.

* AT 632 PM CDT, A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO
WAS LOCATED NEAR COLUMBIA, MOVING EAST AT 45 MPH.

HAZARD...TORNADO.

SOURCE...RADAR INDICATED ROTATION.

IMPACT...FLYING DEBRIS WILL BE DANGEROUS TO THOSE CAUGHT WITHOUT
SHELTER. MOBILE HOMES WILL BE DAMAGED OR DESTROYED.
DAMAGE TO ROOFS, WINDOWS, AND VEHICLES WILL OCCUR. TREE
DAMAGE IS LIKELY.

* THIS DANGEROUS STORM WILL BE NEAR...
SPRING HILL AND THOMPSON'S STATION AROUND 650 PM CDT.

 

[Equus]

Just brief rain and very distant thunder with the line here - the campfire is even still going strong. At least it wasn't a hailstorm.

Huh, there has been tree damage only a few miles away in Eldrige and Nauvoo. There were marginally higher velocity spikes there but never any warnings or significant evidence for severe.

 

[Kory]

Just brief rain and very distant thunder with the line here - the campfire is even still going strong. At least it wasn't a hailstorm.

Huh, there has been tree damage only a few miles away in Eldrige and Nauvoo. There were marginally higher velocity spikes there but never any warnings or significant evidence for severe.

It got rough in Tuscaloosa but sub severe.

 

[Equus]

Judging by lightning output and velocity signatures, looks like I got in a pretty significant lull. Not gonna complain

 

[rolltide_130]

A marked uptick may be coming as we head into April. This 10 day lull we're in now may soon be coming to an abrupt end..