May 2 - 16, 2023 | Severe Weather Sequence

[ClicheVortex2014]

AMA wrote an essay for the afternoon mesoscale update. Doesn't sound like the overnight round is too impressive. Fine with me, need to catch up on my sleep.

.MESOSCALE UPDATE FOR WIND, HAIL, AND A LOW TORNADO THREAT FOR
THIS AFTERNOON THROUGH TONIGHT...
Issued at 241 PM CDT Wed May 10 2023

* Synoptic Overview: The latest 10/18z RAP H500 analysis shows a
  negatively tilted trough located over the Desert Southwest and
  is continuing to move east/northeast early this afternoon. Out
  ahead of this feature, southerly winds continue to advect
  theta-e at H700 across mainly an axis along west TX and east NM.
  This can be seen in the mid level water vapor satellite band and
  with some cumulus clouds developing across northeastern NM.
  Moisture return would be greater across the area if low pressure
  was not located to our southeast along with ongoing convection
  in east and southeast TX. A subtle weak shortwave out ahead of
  the main low pressure system is moving across north central NM
  early this afternoon. Current expectation is that this weak
  disturbance will aid in convective initiation across far
  northeastern NM, as already seen by a thunderstorm developing
  across the higher terrain in NM. The main event so to speak, is
  expected to be during the late evening into the overnight hours
  as the main upper level wave approaches the Panhandles and
  provides stronger PVA. This may generate a secondary round of
  thunderstorms, some of which could be severe, during the
  overnight hours and could continue into early Thursday morning.

* Mesoscale: Latest 18z surface analysis shows dew points are
  continuing to slowly decrease across the Southern High Plains as
  daytime mixing is bringing down drier air from aloft to the
  surface. A surface dry line continues to sharpen across eastern
  NM and is expected to be the surface lifting mechanism to get
  convection started this afternoon. This is already apparent as
  of 1845z, with a shower/storm beginning to develop south of
  Raton, NM. The 10/18z RAP mesoanalysis shows that there may be
  a small area along the dry line that is uncapped at this time,
  with MLCAPE around 1000 J/kg. This is located in the vicinity of
  where the initial storm is beginning to develop. CIN will
  continue to decrease through the daytime hours, but surface
  moisture will also decrease which will lead to lower CAPE
  values. Given the weak upper level flow aloft, any storms that
  form during the afternoon into the early evening hours are not
  expected to be fast moving. With that being said, effective
  shear will be quite weak and may inhibit some of the severe
  weather threat. As thunderstorms move into the western
  Panhandles later this afternoon, the more aggressive models
  suggest that 1000-1500 J/kg of MLCAPE may remain over the area
  along with slowly increasing effective shear as southerly H850
  winds increase to near 30 kts. The better chance of storms being
  surface based looks to be in the northwest based on the more
  aggressive soundings from models that have a higher moisture
  bias. This initial round of storms, which looks to become linear
  based on CAMs and the relatively marginal shear, may continue
  across the west and potentially the central Panhandles til
  midnight. A secondary line of linear storms may develop over
  portions of west TX as the main upper level wave comes across
  during the overnight hours. The first round of convection may
  hinder how far north this secondary line is able to develop as
  portions of the Panhandles could be worked over and may limit
  further thunderstorm development. In any case, low level
  moisture will be on the increase and surface dew points may
  approach the mid to upper 50s, with low 60s further east. As
  moisture increases throughout the column, long skinny CAPE
  profiles look possible with CAPE values around 1000 J/kg. Cannot
  rule out some of these storms potentially becoming surface
  based, which would lead to a low end tornado threat given the
  long low level forecast hodographs. A QLCS may develop as 0-3km
  shear values are near 30 kts along and behind where the line is
  forecast to develop. Several CAMs are depicting that this
  scenario is possible and a brief tornado spin-up looks plausible
  during the overnight hours. Will need to continue to monitor
  the potential for this threat, especially since it is during the
  overnight period.

* Threats: The main threats with any severe thunderstorms this
  afternoon through this evening will be large hail (up to ping pong
  ball) and damaging wind gusts (up to 65 mph). Given the lack of
  moisture this afternoon, especially across the west, CAPE values
  combined with weak shear are not overly supportive of a very large
  hail threat. Even though moisture and shear will increase through
  the overnight hours, as mentioned above, long skinny CAPE profiles
  are possible and are not the most supportive of very large hail.
  Storms are expected to become mainly elevated after sunset tonight
  as we lose daytime heating and capping in the low levels becomes
  prevalent. This will decrease the damaging wind threat, but if a
  QLCS is able to form, some gusty winds could mix down to the
  surface. The low end tornado threat is highly conditional and will
  depend upon the low to mid levels cooling as the upper level wave
  approaches the Panhandles. Cannot rule out a quick spin-up or two
  during the overnight hours. Will need to carefully monitor the
  trends through the overnight hours.

* Timing & Location: Two rounds of thunderstorms are expected over
  the next 12 to 18 hours. The first round is forecast to move in
  across the western Panhandles around 5 to 7 PM Central. A line
  of storms may move across portions of the western Panhandles
  through early evening. A secondary round of thunderstorms may
  develop across portions of west TX during the overnight hours
  (around 11 PM through 1 AM) and is expected to trek east. The
  highest chance at seeing these storms overnight would be across
  the central and/or southern TX Panhandle. These storms are
  expected to be east of the area near sunrise on Thursday.

 

Edited May 10, 2023 by ClicheVortex2014

[snowlover2]

Confirmed tornado in CO.

Quote

Severe Weather Statement
National Weather Service Denver CO
555 PM MDT Wed May 10 2023

COC087-121-110015-
/O.CON.KBOU.TO.W.0013.000000T0000Z-230511T0015Z/
Morgan CO-Washington CO-
555 PM MDT Wed May 10 2023

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 PM MDT FOR
SOUTHEASTERN MORGAN AND NORTHWESTERN WASHINGTON COUNTIES...

At 555 PM MDT, a confirmed tornado was located 6 miles east of Gary,
or 14 miles southwest of Akron, moving north at 30 mph.

HAZARD...Damaging tornado and half dollar size hail.

SOURCE...Weather spotters confirmed tornado.

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.

Locations impacted include...
Midway.

 

[snowlover2]

Quote

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
631 PM MDT WED MAY 10 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0610 PM     HAIL             7 WSW AKRON             40.13N 103.34W
05/10/2023  M3.00 INCH       WASHINGTON         CO   TRAINED SPOTTER

 

[Chinook]

strong rotation at Merino, Colorado

[ElectricStorm]

This might be the smallest watch I've ever seen 

[Ingyball]

Getting pretty concerned about the setup tomorrow. Pretty classic May significant setup for us here. Nice compact low going negatively tilted at the right time, (mini) upper jet intersects the warm sector at nearly 90 degrees. Mid-level cooling lowers cap concerns. It seems like all systems go tomorrow. If there's a failure mode it'd be too much convection (kind of like what's going on in western Kansas today, or that Texas low slows down and causes subsidence at the wrong time.  CIPS has been very inconsistent with one to two big outbreak showing up each run then disappearing. SARS Analogs are much more impressive though with some big outbreaks like the Harper County Kansas F4 in 2004 have shown up on both NAM and HRRR sounding. Here are some of the other outbreaks I found that had high impacts. 

https://en.wikipedia.org/wiki/Tornado_outbreak_sequence_of_June_10–16,_1970#:~:text=The tornado outbreak sequence of,down during the outbreak sequence.

https://en.wikipedia.org/wiki/Tornado_outbreak_of_November_23–24,_2001

https://www.weather.gov/iln/20000920

[snowlover2]

Gorilla Hail!

Quote

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
706 PM MDT WED MAY 10 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0613 PM     HAIL             6 ENE GARY              40.10N 103.47W
05/10/2023  M4.00 INCH       MORGAN             CO   NWS EMPLOYEE

 

[Chinook]

For tomorrow: the 00z HRRR predicts the cap will break near Oklahoma City, with relatively isolated cells. I think there will be an increasing tornado chance along with increasing shear, as the late afternooon-evening SRH gets quite a bit higher.

[ClicheVortex2014]

Bit of a hint of a mid-level meso with this cell. Nocturnal LLJ is kicking in. Thankfully low-level moisture is weak right now so the tornado threat stays low. Will be interesting to see how long it persists and if it can make it into the better moisture and remain surface-based. That's a lot of if's though and I don't think it'll happen

Edited May 11, 2023 by ClicheVortex2014

[Chinook]

update: The FV3 does not really break the cap around Oklahoma City. but the NAM 3km does.

[ClicheVortex2014]

That southern cell is developing quickly 

[Iceresistance]

I didn't post much because I was recording this:

 

[ClicheVortex2014]

New development in east NM

 

Shear is looking pretty good. Instability not so much but moving into greater values.

Edited May 11, 2023 by ClicheVortex2014

[ClicheVortex2014]

Solid jet streak pushing in to western Texas, probably will be good to keep storms going through sunrise

[ClicheVortex2014]

Ahh... thunder and lightning. Love it.

[ElectricStorm]

Day 1 outlook is out, looks pretty similar the the previous Day 2. Need to watch the convection in TX, if it stays strong enough and makes it further east it could possibly limit the severe threat later on. I personally don't really think that will be much of an issue though. 

Storm coverage will probably be too limited for an upgrade to moderate but if models uptrend in storm coverage, and depending on obs tomorrow morning/early afternoon, I wouldn't really be surprised if a small moderate risk area is added later. 

[ClicheVortex2014]

Looks like the low threat for a tornado panned out. Nothing confirmed, nor do I expect one to be, but it's trying. Low-level moisture is improving and low-level shear is pretty decent.

Edited May 11, 2023 by ClicheVortex2014

[ClicheVortex2014]

Cool satellite loop. Clearly 3 rounds of initiation. First round produced damaging winds, second round produced hail, third round tried to produce a tornado.

 

Edited May 11, 2023 by ClicheVortex2014

[ClicheVortex2014]

Might have another mesovortex developing just SW of here

 

[ClicheVortex2014]

Nice thunderstorm day it’s been

[ClicheVortex2014]

Got some rotation by the radar

[Iceresistance]

Morning storms crossing into Oklahoma

 

Another round of severe storms is possible tomorrow.

[Iceresistance]

Enhanced risk is now much bigger in Oklahoma

[Neoncyclone]

The environment forecast to be in place over Central Oklahoma is definitely concerning.. The only potential saving grace i've seen is that models are a bit messy. Really hoping for no discrete storms this afternoon. 

 

[Neoncyclone]

Rotating bean in Louisiana this morning.