Severe weather risk 4/30 - 5/3

[bjc0303]

Euro continues to look pretty potent for Tuesday and Wednesday. 

[Radtechwxman]

4 minutes ago, bjc0303 said:

Euro continues to look pretty potent for Tuesday and Wednesday. 

I was just looking at the height trends on the 12z euro for Wed evening and at 0z it barely had any kind of height falls grazing the warm sector. I'm wondering if with the cap and late jet arrival if we won't see the main show till right before sunset kinda like what happened on 4-14-12. Even though this event and that event aren't really synoptically similar, the late timing of the jet kind of made me think of that because I remember storms all day struggled to produce tornadoes except that wedge in KS near Salina but otherwise the most prolific part of that outbreak was def towards sunset and after dark

[bjc0303]

4 minutes ago, StormChaser4Life said:

I was just looking at the height trends on the 12z euro for Wed evening and at 0z it barely had any kind of height falls grazing the warm sector. I'm wondering if with the cap and late jet arrival if we won't see the main show till right before sunset kinda like what happened on 4-14-12. Even though this event and that event aren't really synoptically similar, the late timing of the jet kind of made me think of that because I remember storms all day struggled to produce tornadoes except that wedge in KS near Salina but otherwise the most prolific part of that outbreak was def towards sunset and after dark

Well the euro has QPF signals suggestive of scattered activity starting in the early afternoon across the dry line, with it continuing into overnight hours into NE OK and eastern KS. 

[jojo762]

10 minutes ago, StormChaser4Life said:

I was just looking at the height trends on the 12z euro for Wed evening and at 0z it barely had any kind of height falls grazing the warm sector. I'm wondering if with the cap and late jet arrival if we won't see the main show till right before sunset kinda like what happened on 4-14-12. Even though this event and that event aren't really synoptically similar, the late timing of the jet kind of made me think of that because I remember storms all day struggled to produce tornadoes except that wedge in KS near Salina but otherwise the most prolific part of that outbreak was def towards sunset and after dark

Something also remarkably similar to that day is that's the euro STILL shows 3000+ J/KG SBCAPE well into the night. Verbatim on the Euro, a tornado threat would likely last well after dark -- something that is particularly concerning.

High-end event appears to be evolving for Wednesday. 

[andyhb]

7 minutes ago, jojo762 said:

Something also remarkably similar to that day is that's the euro STILL shows 3000+ J/KG SBCAPE well into the night. Verbatim on the Euro, a tornado threat would likely last well after dark -- something that is particularly concerning.

High-end event appears to be evolving for Wednesday. 

Considering it's still over 4 days out, I'm not sure it's worth making statements like this.

Sure, the last two runs of the Euro would suggest the potential for a bigger event, but we've seen a number of inside-96 hr downtrends recently.

[jojo762]

1 minute ago, andyhb said:

Considering it's still over 4 days out, I'm not sure it's worth making statements like this.

Sure, the last two runs of the Euro would suggest the potential for a bigger event, but we've seen a number of inside-96 hr downtrends recently.

Why do we always arguing over simple semantics in meteorology/forecasting circles? Not any real problem with you pointing out that it's maybe not necessary yet. But I mean even SPC is already mentioning the possibility of strong tornadoes in a D5 outlook.

 

We have indeed seen many setups completely fall apart in <96 hours recently, so perhaps a bit premature. But it is hard not to get excited for the current progged  setup over such a classic/good area given the bull crap we've had to deal with for several years now. 

[Radtechwxman]

34 minutes ago, jojo762 said:

Something also remarkably similar to that day is that's the euro STILL shows 3000+ J/KG SBCAPE well into the night. Verbatim on the Euro, a tornado threat would likely last well after dark -- something that is particularly concerning.

High-end event appears to be evolving for Wednesday. 

I totally agree man. The ceiling is high for Wed. If that trough ejection can time right and not too late we could def see a tornado event but that remains to be seen. The upper low came onshore today so 0z runs should have a pretty good sampling 

[OUGrad05]

57 minutes ago, jojo762 said:

Something also remarkably similar to that day is that's the euro STILL shows 3000+ J/KG SBCAPE well into the night. Verbatim on the Euro, a tornado threat would likely last well after dark -- something that is particularly concerning.

High-end event appears to be evolving for Wednesday. 

Yeah, I'm definitely concerned about the overnight threat.  Mentioned that to my wife earlier this morning and again after reviewing the 12Z euro.  We're in the Tulsa metro so reasonable likelihood that we are after dark.  Although the significant weather parameters on the 12Z were interesting at 7pm Weds over Tulsa.  Still talking D5...and could be multiple rounds.

[bjc0303]

Here’s what I meant re: QPF. Lots at play here - global cannot resolve convection by any means - but this is as good a signal as any for long lived scattered/discrete activity along the dry line. Mode maybe more questionable into KS with potentially higher forcing. 

Numerous details yet to be resolved, but the euro has me quite giddy for Tues/Weds. 

[Crazieman]

The cold water kings, Wichita is even bullish on their AFD for Wednesday.

Quote

.LONG TERM...(Wednesday through Saturday)
Issued at 253 PM CDT Sat Apr 28 2018

Stronger mid/upper flow will move out across the southern/central
Plains for Wed as the main upper impulse slides over the Desert
Southwest. Meanwhile, low level moisture will continue to pump
into the region with mid 60 dewpoints a good bet by Wed afternoon.
Once again, expecting a triple point to be located somewhere over
west-central KS by Wed afternoon with the dryline extending
into western OK. Currently expecting more widespread storms along
the dryline/warm front Wed due to less capping, better large scale
forcing and richer low level moisture. 0-6km shear will be in the
50 to 60kt range with CAPE in the 2500-3000J/kg range. Low level
shear isn`t that impressive until surface flow starts to back
closer to sunset as low level jet increases. Deep layer shear
looks to be normal to the dryline which should keep anything that
develops along it fairly isolated which should minimize storm
interaction and increase tornado potential, especially toward
evening.

 

[andyhb]

Not to take the attention away from Tuesday and Wednesday, but the 12z/18z runs have me eyeing the TX Panhandle on Monday. Seems like the idea is to get enough moisture in there for the potential of a couple of slow-moving tornadic supercells, the 12z Euro (which has tended to be the most stingy with moisture) had 60s dewpoints getting to CDS by 00z.

Low level shear profiles are looking pretty ideal for the area and coupled with a well-timed shortwave passage should be able to overcome the cap. Might also be a situation where the "just in time" nature of the moisture may help since it won't have a lot of time to mix out (and some early cloud cover wouldn't hurt either). Taking the mean of the solutions, I'd probably set up somewhere E of AMA as it sits right now.

[OUGrad05]

49 minutes ago, andyhb said:

Not to take the attention away from Tuesday and Wednesday, but the 12z/18z runs have me eyeing the TX Panhandle on Monday. Seems like the idea is to get enough moisture in there for the potential of a couple of slow-moving tornadic supercells, the 12z Euro (which has tended to be the most stingy with moisture) had 60s dewpoints getting to CDS by 00z.

Low level shear profiles are looking pretty ideal for the area and coupled with a well-timed shortwave passage should be able to overcome the cap. Might also be a situation where the "just in time" nature of the moisture may help since it won't have a lot of time to mix out (and some early cloud cover wouldn't hurt either). Taking the mean of the solutions, I'd probably set up somewhere E of AMA as it sits right now.

Yes and you have the panhandle...which does fun things.  So not a bad play for Monday I'd say.  

[andyhb]

Thursday looks to have some potential as well on the 18z GFS with a much more meridionally-oriented dryline, albeit it certainly isn't quite as robust as the threat on the previous days.

[bdgwx]

I was going to mention Thursday as well too.

The 12Z EPS suggests that convective activity is maximized pretty much right in the center of the SPC's 30% area for Wednesday. Maybe slightly higher odds on the NE portion of that area if we are splitting hairs.

It looks like the CIPS analog guidance page didn't update today.

[OUGrad05]

Thursday definitely should be watched closely especially if the system continues to slow overall and shift west.  

[jojo762]

00Z GFS is definitely liking the TX PH on Monday. Tuesday looks roughly the same, with significant-severe potential being conditional on storm initiation along the dryline... most likely area for this to occur would appear to be INVOF the triple point. Wednesday continues to look like a big-league day with moderate/strong destabilization and impressive low-level and deep-layer shear along the entire dryline. 00Z GFS precip signal for Wednesday is much like the Euro in depicting several scattered supercells - with perhaps multiple rounds shown on the GFS - near the dryline... again with a significant-severe risk likely lasting well into the overnight hours.

[Chicago Storm]

Have been pondering the idea of chasing, but still not sure...

Mon looks to have the worst potential of all. Dp's likely only to be in the mid-upper 50's at best, weakening UL flow with time, narrow instability axis and capping are all concerns. I've never been fond of "just in time moisture".

Tue does hold decent potential, but is conditional. Departing lead wave and rising heights, but good UL flow and no worries about moisture or instability axis. KS/OK would be the target.

Wed is obviously the best looking day, with few negatives right now. KS/OK target once again.

Thur could hold some potential somewhere, especially if the GFS is right...but still too far out and guidance is all over the place with it.

[Radtechwxman]

6 hours ago, Chicago Storm said:

Have been pondering the idea of chasing, but still not sure...

Mon looks to have the worst potential of all. Dp's likely only to be in the mid-upper 50's at best, weakening UL flow with time, narrow instability axis and capping are all concerns. I've never been fond of "just in time moisture".

Tue does hold decent potential, but is conditional. Departing lead wave and rising heights, but good UL flow and no worries about moisture or instability axis. KS/OK would be the target.

Wed is obviously the best looking day, with few negatives right now. KS/OK target once again.

Thur could hold some potential somewhere, especially if the GFS is right...but still too far out and guidance is all over the place with it.

Why wouldn't you? Nothing else in the long range. And yea the setup isn't perfect but it is way better than the last one at least with better quality moisture and much better flow aloft. When you get a trough like that in May, you chase it. Lol

[Radtechwxman]

Why is this thread so dead? Lol. Looks like 3 solid chase days coming up

[OUGrad05]

2 minutes ago, StormChaser4Life said:

Why is this thread so dead? Lol. Looks like 3 solid chase days coming up

Dunno, I've wondered the same.  Euro has been slowly weakening some of the data points.  It needs to bounce back at some point, compare the last 4 runs looking at shear and winds at various heights.  It's still not bad but also not great.  

[Chicago Storm]

Why is this thread so dead? Lol. Looks like 3 solid chase days coming up

Mon is DOA and Tue/Thur are more conditional.

Only really good day to get excited about is Wed.

Then add in the many other outlets for discussion, such as FB and Twitter...


.

[hlcater]

8 minutes ago, Chicago Storm said:

Mon is DOA and Tue/Thur are more conditional.

Only really good day to get excited about is Wed.

Then add in the many other outlets for discussion, such as FB and Twitter...


.

Monday DOA? Please elaborate.

[weatherextreme]

I know that some don't care for the Torcon to much, but wanted to add this for what Forbes is seeing for WEDNESDAY and Thursday.  Looks like Forbes is seeing something big for Thursday too.

 

 

WEDNESDAY 5/2
Severe thunderstorms in south IA, northwest and possibly extreme west MO, southeast NE, KS, OK except panhandle, northeast, north-central and a strip of west TX from near Wichita Falls to Fort Stockton. TORCON - 5 in west and central OK, west and central KS; 4 east OK and east KS, north-central and northeast TX; 3 rest of region except 2-3 south-central TX.

A low near the CO/KS border continues to bring in warm, moist Gulf of Mexico air, while an upper trough begins to reach the area. Storms form along the dryline from southwest KS to west TX, along the warm/stationary front that spreads into south IA, and in the warm sector where the cap is broken by the approaching upper forcing and increased instability. Low-level shear is more than enough for tornadoes.

 

 

THURSDAY 5/3
Severe thunderstorms in lower peninsula of MI, extreme northwest OH, north half IN, north and central IL, south WI, east IA, MO except southeast, east KS, west AR, central and east OK, northeast and central TX. TORCON - 5 in north-central and northeast TX, OK, KS, AR, and MO areas; 4 IL area; 3 rest of forecast area

A trough of low pressure extends from the Central Plains to the Great Lakes, while a dryline is over central TX, with moist, unstable air ahead of it, an upper trough moving into the area, and a moderately strong low-level jet. Ingredients all present for tornadoes, although the directional change of the low-level wind shear may not be too large.

 

 

 

[Radtechwxman]

One concern I do have now is Euro has drastically backed off on moisture quality. Barely has 65 dews into KS by Wed. Major change from previous runs

[jojo762]

A tor:con of five already for Thursday is a bit surprising. GFS/Euro currently depict ample boundary-layer moisture and instability and sufficient 0-3KM SRH (most GFS soundings depict 200-300m2/s2 along the dryline in KS/OK by 00Z) but the unidirectional profile above 850mb and the uncertainity in regards to the impacts of any early day convection and when/how initiation takes place scares me off a bit.

[andyhb]

6 minutes ago, StormChaser4Life said:

One concern I do have now is Euro has drastically backed off on moisture quality. Barely has 65 dews into KS by Wed. Major change from previous runs

I'm pretty sure that's due to ongoing convection in KS, looking at the QPF fields.

[OKStorm]

 

Still early but you can see some return ongoing so I am not going to jump on the dry wagon just yet.

 

 

[OUGrad05]

Just now, OKStorm said:

 

Still early but you can see some return ongoing so I am not going to jump on the dry wagon just yet.

 

 

Good southerly flow all day today.  15-20 here at my house, I'm in the Tulsa area.  Nice plume of mid 50s already in South Central OK.  With the GOM so warm I wouldn't be surprised to see moisture return a touch better than anticipated, at least early on.

[andyhb]

It would be better to show the trend in moisture (i.e. dTd/dt) than just the absolute values there IMO.

[Radtechwxman]

30 minutes ago, andyhb said:

I'm pretty sure that's due to ongoing convection in KS, looking at the QPF fields.

Yea that's a good point. Didn't think of that. But even into OK I was shocked to only see 65 dews. Before it had upper 60s to low 70s. Got good return flow off the extreme western Gulf right now. As that surface high keeps moving east today should see more of the Gulf open up. Another thing I did notice which could be impacting moisture also is that LLJ core gets shunted east a little from the lead wave causing a weaker branch to the west. Hoping we see good enough secondary low development to reform a better LLJ further west towards dryline