Severe Weather May 26th- 28th 2021

[WXMan42711]

interesting

[CheeselandSkies]

Fresh from busting hard in KS, staying the night in DDC which seemed like a good jumping off point for tomorrow but now that looks to be trending down as well. Yet another sign I should just give up this f***ing hobby.

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[Chinook]

6-hr hail swaths up to 0330z highlight many of the areas that had severe weather or heavy rain. Areas that show 50mm (2") threshold are very likely to have had 2" hail hit the ground.

[stormdragonwx]

Someone correct me if I'm wrong here but I don't trust the CAM's that have been showing a lot of convective overturning as I've been observing the storms out north and west on GR3 for the past few hours and they appear to be weakening and moving away from the risk area. If there's no redevelopment later tonight into the morning then this setup could be explosive tomorrow during peak daytime heating. With the atmosphere we got in place (70+ dews, plenty of shear, and 4k+ CAPE) If there's enough of a cap then I don't see how we couldn't have a couple tornadic supercells before the squall line develops.

[weatherextreme]

1 minute ago, stormdragonwx said:

Someone correct me if I'm wrong here but I don't trust the CAM's that have been showing a lot of convective overturning as I've been observing the storms out north and west on GR3 for the past few hours and they appear to be weakening and moving away from the risk area. If there's no redevelopment later tonight into the morning then this setup could be explosive tomorrow during peak daytime heating. With the atmosphere we got in place (70+ dews, plenty of shear, and 4k+ CAPE) If there's enough of a cap then I don't see how we couldn't have a couple tornadic supercells before the squall line develops.

 

Looks like the SPC is thinking the same .  From the latest Day 1 update 

 

SUMMARY...
   Scattered severe thunderstorms are expected from parts of the
   southern Great Plains into the Ozarks and mid Mississippi Valley. 
   Very large hail, significant severe wind gusts, and some tornadoes
   are possible.

   ...Southern Great Plains to Mid Mississippi Valley...

   Seasonally strong upper trough will shift east across the northern
   Plains today with the primary mid-level jet expected to translate
   across NE/IA into northern IL during the afternoon. This feature
   will be partly responsible for maintaining an MCS that has developed
   over the central Plains early this morning. This activity is
   forecast to spread into IA/northern MO by the start of the day1
   period ahead of the primary surface low. The extent of the cold pool
   will likely prove significant and should prove instrumental in
   forcing a convective outflow well ahead of the main synoptic front.
   As such, leading edge of this MCS may not weaken appreciably as it
   propagates across northern MO into west-central IL. Damaging winds
   are the main threat with this MCS.

   Of more concern will be the pre-frontal air mass along the I-44
   corridor extending across southwest MO through the body of OK into
   the TX South Plains. Latest radar data continues to indicate
   lingering convection along the KS/OK border as well as over the
   eastern TX Panhandle. It's not entirely clear how much of this
   convection will be present at daybreak. Several HREF members suggest
   at minimum there will be left over convective debris, or more likely
   some weak convection at 12z. This activity would likely propagate
   east and possibly reintensify as boundary-layer heating reduces CINH
   by early afternoon. If convection is not too disruptive, then a more
   buoyant air mass may advance into southeastern KS/southwestern MO;
   however, the most likely area for strong instability will remain
   across the southern Plains. This is the most concerning portion of
   the outlook as thunderstorms will develop along the early-day
   outflow boundaries, dryline, and synoptic front. While low-level
   flow should veer a bit into the southwest across this region,
   adequate turning/bulk shear will be present for supercells. Have
   lowered the tornado probabilities a bit across this region but not
   due to the lack of buoyancy/shear. At this time there is too much
   uncertainty regarding the evolution of the early-day convection and
   the possibility for disrupting cold pool. When these boundaries are
   identified later today there may be a region where higher potential
   for a few tornadoes can be addressed.

   Otherwise, severe thunderstorms will develop across a large corridor
   from the TX South Plains, through OK into MO. Very large hail will
   be noted across the southern Plains with supercells and upscale
   growth into an MCS is possible by early evening. If an MCS does
   evolve, damaging winds would become a legitimate concern as this
   activity propagates toward the Red River.

 

[WXMan42711]

some spin ups still ongoing at this hour

[Chinook]

this is quite a long time ago now, but here is the radar for the reported tornado at Perryton, TX (time of 0041z)

[OKwx_2001]

10z HRRR has the storms developing much earlier than previous runs. As early as late morning. I feel like that's too early for tornado potential but it will be interesting if those storm end up materializing or they even remain on later runs

[StormChazer]

My chase target is as clear as mud today.........

[Powerball]

2 minutes ago, StormChazer said:

My chase target is as clear as mud today.........

^^^2021 in a nutshell.

[Calderon]

I'm watching the chances of SVR basically cratering for STL metro with this bullshit slowly moving in from central & western MO. Still no SVR or TOR warning for St. Louis County & City the whole spring.

[StormChazer]

Starting to think we might have a decent chance at tornadoes around I-44 and I-40 this evening....

[StormChazer]

 

[Weatherdemon]

https://www.spc.noaa.gov/products/md/2021/md0763.html

 

Mesoscale Discussion 0763 NWS Storm Prediction Center Norman OK 1104 AM CDT Thu May 27 2021 Areas affected...portions of southeastern Kansas and northeastern Oklahoma across the Ozarks and into parts of southern Illinois Concerning...Severe potential...Watch likely Valid 271604Z - 271730Z Probability of Watch Issuance...80 percent SUMMARY...A gradual increase in storm coverage/intensity -- and attendant severe risk -- over the next couple of hours will likely require WW issuance DISCUSSION...Latest visible satellite imagery shows widespread/ongoing convection and attendant cloud cover, and several outflow boundaries, from southeastern Kansas and Oklahoma east to the mid Mississippi Valley. The ongoing convection is occurring south and east of a cold front extending from a low in southwestern Iowa, southwestward across Kansas to the Texas Panhandle. Ahead of a loosely continuous, composite outflow boundary arcing from northwest of St. Louis westward to southwestern Missouri, and then into northeastern Oklahoma, some heating/destabilization is underway -- particularly from southern Illinois westward across the Ozarks. This trend should continue, resulting in a gradual increase in convective coverage and intensity over the next couple of hours. Area VWP data indicates around 30 kt low-level south-southwesterly flow across the warm sector, veering to west-southwesterly at mid levels. This is providing sufficient shear for organized/mixed-mode convection, and therefore expect severe potential -- mainly in the form of damaging winds and hail -- to gradually increase in concert with convective intensification. As such, expect WW issuance to be required within the next hour.

[OKwx_2001]

Starting to get some clearing here in Tulsa so that will be concerning if it continues.  Currently at my outdoor job so I hope the big stuff holds off until I get home (I'm off at 2). I would much rather track it at home than drive in it.

[Weatherdemon]

Area Forecast Discussion
National Weather Service Tulsa OK
1124 AM CDT Thu May 27 2021

.DISCUSSION...

Forecast has been updated this morning based on the latest trends
in the data. Model soundings this morning were weakening the cap
fairly quickly today, likely due to ascent from warm
advection/isentropic lift evident on 305K surface. 12Z OUN 
sounding showed very steep mid level lapse rates and large CAPE, 
with decent deep layer shear. Low level shear is still fairly 
weak. Storms are already ongoing across NE OK, evidence of 
weakening cap. More storms to develop later today as daytime 
heating continues, even with quite a bit of cloud cover, as very 
rich low level moisture is in place with low 70s dewpoints. Very 
large hail and damaging winds main threats. Tornado potential 
should be localized and focused along outflow boundaries, though 
given the time of year and the environment, the potential does 
exist for a strong tornado. Storms eventually congeal into an MCS 
and plow southeast with wider swaths of damaging wind potential 
becoming main threat. A QLCS tornado threat will exist on any 
bowing structures that surge to the east to northeast. With
multiple rounds of storms possible along and north of I40 thru
tonight, a flash flood watch has been issued.

[nrgjeff]

I like western Oklahoma today, except it'll be so crowded!

Kansas convection does not seem to want to enter Oklahoma, keeping OK undisturbed. Also some gravity waves are down in Oklahoma, well ahead of the Kansas cold front. Those will likely be a focus for afternoon development. HRRR seems to have that.

12Z NAM/AWR versions had too much northern Oklahoma action early. While I normally don't lean on mid-morning HRRRs they are probably more accurate than the 12Z suite.

Reading some cold front pessimism in places (dark corners of the Internet, lol). We are talking gravity waves south of the CF. It's May 27 not May 7. Could work out!  

[Weatherdemon]

Mesoscale Discussion 0764 NWS Storm Prediction Center Norman OK 1129 AM CDT Thu May 27 2021 Areas affected...eastern Texas Panhandle...Oklahoma. far southern Kansas and northwest Arkansas Concerning...Severe potential...Watch likely Valid 271629Z - 271730Z Probability of Watch Issuance...80 percent SUMMARY...Thunderstorms are expected to develop across western through central Oklahoma by early afternoon and gradually spread east. Supercells with isolated large hail will be the initial main threat, but isolated damaging wind and a few tornadoes are also possible. DISCUSSION...Latest objective analysis show the atmosphere to be moderately to strongly unstable (2500-3000 J/kg MLCAPE) across western through central OK supported by steep mid-level lapse rates above rich low-level moisture with surface dewpoints in the low 70s F. Latest trends in radar show a few showers developing within a modest warm advection regime in the pre-frontal warm sector across western OK. While some remnant capping may still exist, convective inhibition should gradually weaken as temperatures rise into the low 80s F. Rap analysis data show a mid-level jet approaching this region from the west, and effective bulk shear profiles will gradually increase to between 40 and 50 kt through the afternoon. This environment should support discrete supercells as the initial storm mode with large to very large hail likely. While low-level hodographs are not particularly large with 0-1 km storm relative helicity between 100-150 m2/s2 isolated tornadoes cannot be ruled out given degree of instability and a very moist boundary layer with relatively low LCLS. Additional storms may develop along the cold front by late afternoon across southern KS into northern OK and these will also likely become severe. ..Dial/Hart.. 05/27/2021

[JoMo]

Flash flood warning here. Strong storm, pouring. (Around 2" rain in 45 mins) Hopefully that ends my severe chances today. Area around Tulsa and to the S and W of there looks like it could be an area of concern.

[thunderbird12]

Tornado watch issued for much of OK until 7 PM CDT. Tor probs for the watch are relatively low (40/20), but high probs for wind/hail (70/60 for both). 

[Weatherdemon]

Public | Counties | Probabilities | Aviation | Warnings | Initial RADAR

Hazard Tornadoes EF2+ Tornadoes Likelihood Moderate Low Severe Wind 65 kt+ Wind High Moderate Severe Hail 2"+ Hail High Moderate Note:  The expiration time in the watch graphic is amended if the watch is replaced, cancelled or extended. Note: Click for Watch Status Reports. SEL5 URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 215 NWS Storm Prediction Center Norman OK 1155 AM CDT Thu May 27 2021 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Northern and Central Oklahoma * Effective this Thursday morning and evening from 1155 AM until 700 PM CDT. * Primary threats include... A couple tornadoes possible Scattered damaging winds and isolated significant gusts to 80 mph likely Scattered large hail and isolated very large hail events to 3 inches in diameter likely SUMMARY...Thunderstorms will develop and intensify through the afternoon across the watch area, with supercells possible. Very large hail and damaging winds are the main threat, but there is some concern for a few tornadoes in the most intense cells. The tornado watch area is approximately along and 65 statute miles north and south of a line from 50 miles west northwest of Clinton OK to 20 miles south southeast of Fayetteville AR. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings.

[thunderbird12]

First tornado watch for the OKC metro since January 10, 2020, a span of over 16 months. 

[ouamber]

Sunny and very humid in Tulsa right now!

[JoMo]

That storm near Vinita, (NE OK) is looking suspect, tagged tornado possible.  (They dropped the tag)

[StormChazer]

First tornado warning! Loyal, OK

[schoeppeya]

Could be an ugly look if that boundary gets pushed all the way down into the Tulsa area.

[StormChazer]

4 minutes ago, schoeppeya said:

Could be an ugly look if that boundary gets pushed all the way down into the Tulsa area.

Can confirm, we've been cooking in the sun here in Tulsa for a bit now...85 degrees out.

[StormChazer]

Mike Armstrong on Channel 5 just had rotation drop right ontop of him, literally.

[cheese007]

1 minute ago, StormChazer said:

Mike Armstrong on Channel 5 just had rotation drop right ontop of him, literally.

https://www.koco.com/nowcast

[weatherextreme]

Nathan steaming live

 

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