Severe Weather Threat May 17-19, 2025

[UpperLevelLOL]

 

[OH-IOan]

Go easy

No, it's my fault for not mentioning the year. I had a brain fart and forgot that April 27 existed.

 

[jiharris0220]

There’s been storms by Woodward since this morning?

The currently severed warned storms in north eastern Oklahoma have been here since this morning.

It’s all elevated convection, and isn’t the dryline line convection I’m talking about.

 

[Schoeppeya]

Yeah thought this would happen yesterday, I’d be pretty uncomfy from kingfisher to Guthrie to Stillwater

 

[Jbop]

Mesoscale Discussion 0859
NWS Storm Prediction Center Norman OK
0212 PM CDT Sun May 18 2025

Areas affected...northeast Colorado...western Nebraska...northwest
Kansas

Concerning...Severe potential...Watch likely

Valid 181912Z - 182145Z

Probability of Watch Issuance...95 percent

SUMMARY...Supercells capable of very large hail, tornadoes, and
damaging wind are likely to develop after 21Z over northeast
Colorado, spreading into western Nebraska and northwest Kansas
through evening.

DISCUSSION...A surface low continues to deepen over eastern CO as
the shortwave trough moves across the area. Surface analysis shows a
prominent plume of low-level moisture extending out of western KS
and across northeast CO, where dewpoints are holding in the lower
50s F.

Full heating near and south of this moisture plume will erode the
minimal capping inversion by around 21Z, and rapid thunderstorm
development is expected. The combination of strong instability,
steep lapse rates, and veering winds with height will strongly favor
supercells capable of very large hail, and a few tornadoes. Activity
should easily remain severe into NE and KS this evening as the
southeasterly low-level jet persists, maintaining moisture advection
as well as shear and inflow.

 

[OH-IOan]

 

[TornadoFan]

 

[Muwx]

The currently severed warned storms in north eastern Oklahoma have been here since this morning.

It’s all elevated convection, and isn’t the dryline line convection I’m talking about.

I’m talking about the convection that has started to form on the dry line near Woodward

 

[Tennie]

Wouldn't be surprised if that's on the ground. The terminal radar at the Denver International Airport shows a very tight couplet south of Watkins.
View attachment 42218

I just saw a Spotter Network report of a landspout in that area. There likely is something down right now.

EDIT:

And there's the report that I mentioned earlier!

 

[US_Highway15]

Tornado Warning in effect for a storm south east of Denver. Pretty good couplet on it.

 

[Ozonelayer]

What a beauty. Hate that we already have a tornado though, because if the ingredients are there in CO, then it could be a very long day in KS/OK.

 

[Jbop]

Mesoscale Discussion 0858
NWS Storm Prediction Center Norman OK
0158 PM CDT Sun May 18 2025

Areas affected...Northwest to west-central Texas

Concerning...Severe potential...Watch likely

Valid 181858Z - 182130Z

Probability of Watch Issuance...80 percent

SUMMARY...Thunderstorm development along the dryline is expected
roughly between 20-22 UTC across northwest to west-central Texas.
The convective environment will support supercells capable of large
hail, severe gusts, and a few tornadoes. Watch issuance is likely as
storms begin to develop.

DISCUSSION...Recent GOES visible imagery shows shallow, but slowly
deepening, cumulus along and just ahead of a sharpening dryline as
it continues to mix east and boundary-layer depth increases amid
filtered diurnal heating. Latest RAP/HRRR forecast soundings suggest
any lingering MLCIN will be minimized as surface temperatures warm
into the 92-95 F range over the next few hours within the warm
sector. Regional VWPs show flow within the lowest 2-3 km AGL
oriented roughly along the dryline, which should promote adequate
residence times for parcels to reach their LFCs and initiate deep
convection. Latest high-res solutions suggest this should occur
generally between 20-22 UTC. Thunderstorms will mature within a very
unstable air mass with MLCAPE values exceeding 4000 J/kg and
effective shear on the order of 40-50 knots. Limited directional
shear will initially promote splitting supercells with an attendant
very large hail threat (most probable max hail size may be 2-3
inches in diameter). Southeasterly low-level winds across northwest
TX may support adequate low-level veering for some tornado threat.
Further south (roughly south of I-20), 1.5 to 2.5 km LCL heights and
more backed low-level flow will modulate the initial tornado
potential. After 00 UTC a strengthening low-level jet will increase
low-level hodograph curvature and support an increasing tornado
threat with any remaining discrete right-moving supercells across
much of central/northern TX. Watch issuance will likely be needed as
thunderstorm initiation becomes more imminent.

 

[jiharris0220]

Honestly looking at the mesoscale, I wouldn’t be surprised if west central Oklahoma stole the show from Kansas.

 

[TornadoFan]

Well, didn't expect my home state to kick things off today

 

[Ozonelayer]

Honestly looking at the mesoscale, I wouldn’t be surprised if west central Oklahoma stole the show from Kansas.
View attachment 42222

If anything drops in that environment, then it could be intense to possibly violent. Big emphasis on the 'possibly'

 

[OH-IOan]

Here's another great photo:

 

[Schoeppeya]

If any of those towers going up around Woodward become established this early it will severely cap the ceiling of this event from Kansas border northward in my opinion.

Theta -E advection of moist air is still occurring over a vary narrow area and probably need a few more hours of intensifying low level flow to modify that

 

[Muwx]

Honestly looking at the mesoscale, I wouldn’t be surprised if west central Oklahoma stole the show from Kansas.
View attachment 42222

Cloud cover really limited the SC KS threat.

 

[Jimruns]

What actually led to 5/20/19 not living up to the forecast? I’ve never found out why.

Trey did a video on the whys

 

[jiharris0220]

If anything drops in that environment, then it could be intense to possibly violent. Big emphasis on the 'possibly'

It’s a limited window for sure, how long supercells remain discrete once the LLJ fully kicks in only gives a time around 3hours for the greatest tornado potential, if even that.

So far, it looks like the NWS made the right call for the small area of 10-15% tornado probs.