May 2 - 16, 2023 | Severe Weather Sequence

[Chinook]

8 hours ago, Iceresistance said:

I thought that CAPE over 7000 was physically impossible O_O

It is not impossible. For a real-life sounding it takes #1. The SPC/Sharppy calculation based off virtual temperature instead of temperature, which I guess is technically correct. (That's fairly standard these days)  #2 high surface temperature #3 high surface point #3 high lapse rates with the EML. Other discussion: obviously this is rare to get over 6000 J/kg of CAPE (in any format)  so there just have to be some rare elements in terms of high lapse rate and high equilibrium level. And, I don't know if we have the higher surface temperatures for this so early in May.

Tomorrow:

It looks like the CAPE could be fairly typical with 2000 J/kg or somewhat less. There should be quite a bit of high clouds east of the dryline.  There may be some non-severe rainstorms hanging out, cooling the air in central Oklahoma. There should be scattered severe storms. As for shear but I'd say 40 knots of deep layer shear with variable 0-3km storm relative helicity, possibly increasing to over 300 m2/s2 after 03z. I can't decide if I think the SPC will go for a slight risk approach or if I think the SPC will bump up to enhanced risk in at least one portion of the area east of the dryline.

[ClicheVortex2014]

Looks like the northern Texas Panhandle is picking up some beneficial rain tonight. Borger is already at half an inch of rain, obviously with much more to come with the next updates. Dumas is at a quarter inch.

I think Borger is gonna be the big winner today in terms of rain.

Edited May 4, 2023 by ClicheVortex2014

[ClicheVortex2014]

This gust front ain't messing around

[ClicheVortex2014]

What a bonus

[ClicheVortex2014]

Panhandle magic when there’s a significant drought in place

Edited May 4, 2023 by ClicheVortex2014

[ClicheVortex2014]

Borger got 1.38", Amarillo got 0.6", and Dumas got 0.5". Solid win for a day we weren't expecting much.

By the way, these locations have had less than 2.5" so far this year prior to today.

Edited May 4, 2023 by ClicheVortex2014

[Iceresistance]

Woke up to a complex just to my west

[ElectricStorm]

This morning convection seemed to be decently strong, that's probably going to significantly limit severe potential later today in OK. SPC already removed the 5% tor area and 15% wind area and trimmed the slight risk to the west. Wouldn't surprise me if they remove it entirely from OK next update. Hopefully we can get a decent storm later still, but looking less likely.

[Iceresistance]

16 minutes ago, ElectricStorm said:

This morning convection seemed to be decently strong, that's probably going to significantly limit severe potential later today in OK. SPC already removed the 5% tor area and 15% wind area and trimmed the slight risk to the west. Wouldn't surprise me if they remove it entirely from OK next update. Hopefully we can get a decent storm later still, but looking less likely.

And there is more behind it!

[ElectricStorm]

46 minutes ago, Iceresistance said:

And there is more behind it!

Yep next round is about to move in here pretty soon. Starting to look like a pretty good rain day now, hopefully we can get some more from the third round later. 

[Ingyball]

Well the Oklahoma convection has robbed me of moisture return so it's looking like a swing and a miss for storms and any rain here. Just haven't been able to cash in since February. 

[ElectricStorm]

As expected, most of OK has been downgraded to marginal. Looks like a small area of favorable tornado potential could materialize in far SW OK/NW TX along the red river, where a 5% tor area has been added.

Another thunderstorm heading my way, so far it's been a great day for rain/non severe storms. I'd certainly rather have this than something like 2/26 or 4/19

Edited May 4, 2023 by ElectricStorm

[Iceresistance]

This is likely going to turn into an extended sequence, stalled trough from the west incoming this weekend...

[Chinook]

2 hours ago, Iceresistance said:

This is likely going to turn into an extended sequence, stalled trough from the west incoming this weekend...

There have 33 severe reports since the beginning of the month. Small slight risk tomorrow. Marginal, Day 3. no circled areas on Day 4-8. Wake me up when the cold pattern has given way to an actual severe weather pattern.

[Chinook]

by the way, our nasty overly-long upper level trough came from a phasing

http://www.greatlakes.salsite.com/April_28_2023_500mb_loop.html

[Chinook]

flying eagle at Eagle Pass  TX

 

[Iceresistance]

Saturday or Sunday could be big, really big. The Mesoscale models are up to something here...

[ClicheVortex2014]

Wednesday could be an interesting day around here. Got some moderate instability with very strong directional shear and decent speed shear.

 

Snippet from my AFD (apparently proof reading twice isn't enough for the first mid shift)

Wednesday could be the most interesting day of this long-term
period. Guidance have the western US upper-level trough in the
vicinity of Las Vegas by 7am Wednesday before it moves east-
northeast through the day. At that time 700mb winds may be
southwesterly, but southerly 700mb winds are expected through the
afternoon and evening hours in the east which will advect some
healthy 700mb theta-e values. By the afternoon, there should be a
seasonably robust surface low in Colorado, possibly as deep as
990mb, and guidance are showing upper-50 to lower-60 dew points in
the eastern half of the Panhandles. There`s a pretty good signal
that storms will develop on a surface trough with the NBM
producing almost 40% to almost 50% PoPs in the east. If
thunderstorms develop along this axis, strong to severe
thunderstorms would be possible with large hail and damaging winds
the more likely hazard. The tornado threat would be conditional
upon the kind of low-level moisture content that verifies.

All that said, there is model disagreement. The 00z deterministic
ECMWF has a less amplified western trough and keeps it northwest of
the Panhandles on Wednesday. However, it has better dew points
across the Panhandles, and even has a sharp dryline in the far west,
but the winds aloft are weak due to being far removed from the upper-
level trough which would lower any threat for strong to severe
thunderstorms. This would be good for a better chance for
precipitation across the area, and a solution like this is probably
why NBM has 20-30% PoPs across the west. Will watch what the 00z EPS
mean shows, which likely won`t be fully loaded until after this AFD
is sent, but the 12z suite showed EPS is more in line with GFS/GEFS
than its own deterministic model. Therefore, it seems the
deterministic ECMWF is on its own island.

 

Edited May 5, 2023 by ClicheVortex2014

[NWOhioChaser]

Send some storms my way. Boring stretch of weather in the lower Great Lakes. Glad some are getting some much needed rain 

Edited May 5, 2023 by NWOhioChaser

[Iceresistance]

The HRRR Is truly up to something here, very explosive convection in Oklahoma and Texas.

 

I still have Saturday and Sunday as "Conditional", but it's looking nasty.
(My own forecast, please take this with a grain of salt)

[ElectricStorm]

Main threat for Sat/Sun looks to be large hail and strong winds. With weak forcing and very weak shear, the tornado threat should be low (but not 0).

I'm expecting one or both days to be upgraded to slight risk around here, hopefully any big hailers miss the populated areas. 

[StormfanaticInd]

This weekend should produce some good storms. Not sure about the tornado threat yet

[ElectricStorm]

18z HRRR shows a solid, relatively short-lived squall line tomorrow evening/overnight. Definitely agree with the SPC adding the slight risk, and wouldn't be surprised if they expand it north a bit in future updated. Definitely some decent storm potential here, hopefully we can cash in. Tornado threat should be very low, but not entirely ruled out. 

I'm still pretty interested in Sunday, but for the slight risk area and the marginal risk for the southern plains. I think there could be some decent tornado potential in IA. We'll see what the CAM's have as we get closer, but I think we could potentially see an upgrade to enhanced at some point. 

Further south I think we could see an upgrade to slight, really just depends on if storms can develop or not. Similar to tomorrow, shear will still be pretty weak so I don't think we'll see much of a tornado threat, but there once again could be some large hail/strong winds. 

18z GFS thinks Monday could be interesting, I haven't really been paying much attention to anything past the weekend yet, but if that verifies we could be looking at several more smaller-scale setups over the next week or so. Seems like everyone is all doom and gloom on social media which I guess is understandable from a chasing perspective, but I'm overall optimistic about the next week or so, as long as we can cash in on some decent storms. 

[Iceresistance]

0z HRRR goes crazy for Saturday, and maybe a repeat except more discrete Supercells on Sunday? Too far out for Sunday for the HRRR as it's just starting to show it.

[ElectricStorm]

Enhanced risk added for hail