April 2-8, 2023 | Severe Storms

[StormfanaticInd]

I am still very impressed/worried about Tuesday and Wednesday 

Edited April 2, 2023 by StormfanaticInd

[Iceresistance]

14 minutes ago, StormfanaticInd said:

I am still very impressed/worried about Tuesday and Wednesday 

Had some storms that tried to develop over me, but they collapsed.

[StormfanaticInd]

Could be some marginal severe on monday

[ClicheVortex2014]

Feels incredible outside. 81 degrees with 10 degree dew point. 

Under a high wind watch for Tuesday... 35-45 mph sustained winds, gusting up to 65. I knew this area is windy but geez. Assuming a massive change doesn't happen, this will be the 7th high wind warning of 2023. Averaging roughly 1 every 2 weeks.

Edited April 2, 2023 by ClicheVortex2014

[StormfanaticInd]

 

[StormfanaticInd]

3 minutes ago, StormfanaticInd said:

 

Feels like a May setup

[Sentinel]

4 minutes ago, StormfanaticInd said:

Feels like a May setup

This is a nasty set up... 

[Iceresistance]

Tornado Watch up for Northern Texas and Southern Oklahoma, this does NOT include my location!

[StormfanaticInd]

KIND

Long Term...(Monday night through Sunday)
Issued at 304 PM EDT Sun Apr 2 2023

...CONTINUING TO MONITOR POTENTIAL FOR ANOTHER REGIONAL SEVERE
WEATHER OUTBREAK TUESDAY INTO WEDNESDAY...

***BOTTOM LINE UP FRONT***

* Citizens of central Indiana should be weather aware and prepared
  Tuesday into Wednesday this week.

* Potential remains for another significant severe weather event for
  central Indiana Tuesday into Wednesday, primarily somewhere in the
  Tuesday night into midday/early afternoon Wednesday window.
  Significant uncertainties remain and confidence in details is
  modest at best.

* Guidance trends in the last 24 hours have shifted the synoptic
  pattern slightly westward and thus cold frontal passage later in
  time, potentially late Tuesday night to as late as early Wednesday
  afternoon. This trend may result in less favorable timing for
  severe storms evolving from Tuesday`s event, particularly surfaced-
  based convection that would include a tornado and damaging wind
  threat, but could also result in a severe threat Wednesday with
  all hazards on the table, depending upon how late in the day the
  front passes.

* Frontal passage earlier in the Tuesday night/Wednesday time frame
  would most likely have a higher risk of a broad QLCS wind/tornado
  threat, while a later passage could result in a tendency toward
  more discrete storm modes on Wednesday with all hazards possible,
  albeit with a slightly less potent, but still favorable
  environment for severe storms as the cyclone occludes and begins
  to weaken. Evolution of the mesoscale environment Tuesday into
  Wednesday will drive the resultant modes and threats, and remains
  highly uncertain.

***MORE ON OVERALL LONG TERM FORECAST DETAILS***

Primary focus for the long term will be on Tuesday into Wednesday,
April 4th-5th. Guidance remains broadly consistent in developing an
extremely strong low pressure system to the lee of the Rockies as a
potent upper level trough digs into the western CONUS early in the
week. This low very quickly wraps up and pivots rapidly northeast
from the central Plains into the upper Midwest/far western Great
Lakes Tuesday into Wednesday.

Severe outbreak potential for somewhere in the Missouri/Mississippi
Valleys and potentially eastward into the Ohio and Tennessee Valleys
remains a major threat, with outcomes dependent upon evolution of
the mesoscale environment that can still only primarily be inferred.

The surface cyclone should feature a large open warm sector, with
ample instability owing to strong warm advection and poleward
moisture transport, and anomalously strong flow throughout the depth
of the troposphere evolving to our west during the day on Tuesday
and translating eastward as the cold front does so late Tuesday into
Wednesday. Extremely strong low level and deep layer shear is
expected, with the threat for supercell storm modes to our west
initially, potentially growing upscale into a potent QLCS, although
more discrete storm modes still cannot be ruled out. How far
eastward this QLCS might persist before rapidly weakening is highly
dependent upon timing and position of the cyclone/cold front and is
a significant source of uncertainty at this time.

Forecast profiles in the area depict a significant capping inversion
during the day into the evening, which would allow instability to
build and inhibit convection during the day in the open warm sector,
but this is a also source of uncertainty and will significantly
impact evolution and magnitude of the severe threat. Euro Extreme
Forecast Index (EFI) and Shift of Tails (SoT) continues to suggest
anomalously high instability regionally Tuesday into Tuesday night,
although these values are marginally lower and also shifted
west/northwestward in the latest data.

A primary, major source of uncertainty is the longitudinal position
of the front and preceding warm sector Tuesday into Wednesday and
timing of its passage. Overall guidance trends in the last 24 hours
have been to the west, which is commonly seen with extremely deep
and rapidly developing cyclones. CIPS severe analogs depict the
highest severe risk even further west over southern Iowa/western
Missouri/northeast Oklahoma, but this guidance was also the furthest
west for Friday`s event. Experimental machine learning severe
weather guidance from CSU is pegged to its maximum level in nearly
an identical area to the starting point of Friday`s outbreak, but
just slightly westward, from southeast Iowa and western Illinois
into northwest Arkansas, with high probabilities extending again
into central Indiana and surrounding vicinity - especially the
western half of the area.

A potential scenario which would trend toward a wider scale damaging
wind threat and away from significant tornado threat for central
Indiana is that the forcing/shear vectors may be slightly more
boundary parallel on Tuesday than last night`s event, but subtle
changes to this or any of a number of other factors will have a
significant impact upon the evolution of the environment and
resultant threats.

Overall, this pattern has a broad range of possible outcomes - a
high ceiling for widespread severe storms, but also a non-negligible
underperformance potential depending upon timing and evolution of
the environment in the warm sector.

In addition to the severe weather threat, another strong synoptic
wind event will accompany this cyclone, with 925 mb flow likely
around 45-50KT and an 825 mb low level jet as high as 60-65KT, which
again looks quite familiar. Gusts Tuesday night into Wednesday
appear likely to be in the 45-50 MPH range with a few higher gusts
likely, and yet another wind headline may be necessary for that time
frame. Euro EFI/SoT again remain strongly suggestive of a
climatologically anomalous wind event Tuesday night into Wednesda

[StormfanaticInd]

15 minutes ago, Iceresistance said:

Tornado Watch up for Northern Texas and Southern Oklahoma, this does NOT include my location!

Should be some big hail and of course tornado. Some significant 

[ClicheVortex2014]

Warm front is producing several non-tornadic supercells. Main event in the next several hours

[ElectricStorm]

Severe thunderstorm warning here. Starting to hear some thunder now

[ElectricStorm]

Got some tiny hail here as the main core passed just to my south. Marginal risk coming in clutch up here. 

[Hoosier]

1 hour ago, StormfanaticInd said:

KIND

Long Term...(Monday night through Sunday)
Issued at 304 PM EDT Sun Apr 2 2023

...CONTINUING TO MONITOR POTENTIAL FOR ANOTHER REGIONAL SEVERE
WEATHER OUTBREAK TUESDAY INTO WEDNESDAY...

***BOTTOM LINE UP FRONT***

* Citizens of central Indiana should be weather aware and prepared
  Tuesday into Wednesday this week.

* Potential remains for another significant severe weather event for
  central Indiana Tuesday into Wednesday, primarily somewhere in the
  Tuesday night into midday/early afternoon Wednesday window.
  Significant uncertainties remain and confidence in details is
  modest at best.

* Guidance trends in the last 24 hours have shifted the synoptic
  pattern slightly westward and thus cold frontal passage later in
  time, potentially late Tuesday night to as late as early Wednesday
  afternoon. This trend may result in less favorable timing for
  severe storms evolving from Tuesday`s event, particularly surfaced-
  based convection that would include a tornado and damaging wind
  threat, but could also result in a severe threat Wednesday with
  all hazards on the table, depending upon how late in the day the
  front passes.

* Frontal passage earlier in the Tuesday night/Wednesday time frame
  would most likely have a higher risk of a broad QLCS wind/tornado
  threat, while a later passage could result in a tendency toward
  more discrete storm modes on Wednesday with all hazards possible,
  albeit with a slightly less potent, but still favorable
  environment for severe storms as the cyclone occludes and begins
  to weaken. Evolution of the mesoscale environment Tuesday into
  Wednesday will drive the resultant modes and threats, and remains
  highly uncertain.

***MORE ON OVERALL LONG TERM FORECAST DETAILS***

Primary focus for the long term will be on Tuesday into Wednesday,
April 4th-5th. Guidance remains broadly consistent in developing an
extremely strong low pressure system to the lee of the Rockies as a
potent upper level trough digs into the western CONUS early in the
week. This low very quickly wraps up and pivots rapidly northeast
from the central Plains into the upper Midwest/far western Great
Lakes Tuesday into Wednesday.

Severe outbreak potential for somewhere in the Missouri/Mississippi
Valleys and potentially eastward into the Ohio and Tennessee Valleys
remains a major threat, with outcomes dependent upon evolution of
the mesoscale environment that can still only primarily be inferred.

The surface cyclone should feature a large open warm sector, with
ample instability owing to strong warm advection and poleward
moisture transport, and anomalously strong flow throughout the depth
of the troposphere evolving to our west during the day on Tuesday
and translating eastward as the cold front does so late Tuesday into
Wednesday. Extremely strong low level and deep layer shear is
expected, with the threat for supercell storm modes to our west
initially, potentially growing upscale into a potent QLCS, although
more discrete storm modes still cannot be ruled out. How far
eastward this QLCS might persist before rapidly weakening is highly
dependent upon timing and position of the cyclone/cold front and is
a significant source of uncertainty at this time.

Forecast profiles in the area depict a significant capping inversion
during the day into the evening, which would allow instability to
build and inhibit convection during the day in the open warm sector,
but this is a also source of uncertainty and will significantly
impact evolution and magnitude of the severe threat. Euro Extreme
Forecast Index (EFI) and Shift of Tails (SoT) continues to suggest
anomalously high instability regionally Tuesday into Tuesday night,
although these values are marginally lower and also shifted
west/northwestward in the latest data.

A primary, major source of uncertainty is the longitudinal position
of the front and preceding warm sector Tuesday into Wednesday and
timing of its passage. Overall guidance trends in the last 24 hours
have been to the west, which is commonly seen with extremely deep
and rapidly developing cyclones. CIPS severe analogs depict the
highest severe risk even further west over southern Iowa/western
Missouri/northeast Oklahoma, but this guidance was also the furthest
west for Friday`s event. Experimental machine learning severe
weather guidance from CSU is pegged to its maximum level in nearly
an identical area to the starting point of Friday`s outbreak, but
just slightly westward, from southeast Iowa and western Illinois
into northwest Arkansas, with high probabilities extending again
into central Indiana and surrounding vicinity - especially the
western half of the area.

A potential scenario which would trend toward a wider scale damaging
wind threat and away from significant tornado threat for central
Indiana is that the forcing/shear vectors may be slightly more
boundary parallel on Tuesday than last night`s event, but subtle
changes to this or any of a number of other factors will have a
significant impact upon the evolution of the environment and
resultant threats.

Overall, this pattern has a broad range of possible outcomes - a
high ceiling for widespread severe storms, but also a non-negligible
underperformance potential depending upon timing and evolution of
the environment in the warm sector.

In addition to the severe weather threat, another strong synoptic
wind event will accompany this cyclone, with 925 mb flow likely
around 45-50KT and an 825 mb low level jet as high as 60-65KT, which
again looks quite familiar. Gusts Tuesday night into Wednesday
appear likely to be in the 45-50 MPH range with a few higher gusts
likely, and yet another wind headline may be necessary for that time
frame. Euro EFI/SoT again remain strongly suggestive of a
climatologically anomalous wind event Tuesday night into Wednesda

Will dig into this more as it approaches and gets into CAM range, but the stuff I glanced at suggested that surface based storms may still be possible even well after midnight/Wednesday morning, albeit in an environment with weaker instability compared to earlier on Tuesday.

[Iceresistance]

I'm hearing Thunder, Convective Feedback is really going.

 

Tornado Warning near Marlin, TX

[ElectricStorm]

Confirmed tornado near Kosse, TX

[ClicheVortex2014]

Tuesday looks like a long day even this far west of the dryline. Not as long as farther east, but still

.LONG TERM ...
(Tuesday through next Saturday)
Issued at 207 PM CDT Sun Apr 2 2023

Critical fire weather conditions Tuesday with high winds possible.
Quiet rest of week.

Tuesday will see the upper level low eject into the Northern
Plains and place the Panhandles under the jets. Mixing looks to
start early Tuesday with the stronger winds. Winds have slightly
increased in models, thus have used a 1:1:1 blend of ConsMOS, NBM,
and NBM90 to account for the length and spread of possible mixing.
Wind gusts may now be as high as 70 mph. NBM gives a 77 percent
chance of wind gusts greater than 56 kts (65 mph) for Dalhart, 68
percent chance at Guymon, a 65 percent chance at Borger, and a 64
percent chance at Amarillo. The cold front that is expected to
push southward into the FA has slowed down and looks to turn winds
northerly starting around midnight or so. Critical fire weather
conditions are a slam dunk with fuels being around the 90th
percentile. Blowing dust will be very likely as well due to the
drought conditions and strong winds. Winds should ease back in the
evening hours and especially in the post-frontal air mass.

Thursday through the weekend still has divergent solutions between
models. The trough that looks to form in the south goes far enough
south that this run of the NBM has decreased precip chances again
to a small portion of the southeast just on Saturday night. Expect
this will likely disappear like the rest of the chances for
precip have. Long range models did agree on temps being likely
warmer with having the trough dig further south, keeping clouds
from being as thick or forming at all. So far though, perhaps only
elevated fire weather conditions may form from this change.

 

Edited April 2, 2023 by ClicheVortex2014

[Hoosier]

The 3 km NAM doesn't go out this far, but here's a NAM forecast sounding from northern IL at 12z Wednesday.  There's little CINH and one could argue that storms may be able to be sfc based even at that time of morning, but it's obviously something that will need to be refined as we get closer.  

[ClicheVortex2014]

00z HRRR is uhh... a little bit more aggressive with the dryline

[Hoosier]

00z HRRR does pop some discrete cells in IL during Tuesday afternoon.

Also has 70 degree dewpoints around the Quad Cities.  I'll believe that when I see it.

[ElectricStorm]

That environment on the 0z HRRR is unreal, if that even comes close to verifying and a storm can break the cap that would be a major problem. This run doesn't fire a ton of storms but reflectivity output at the 48 hour range can be questionable. Really interested to read the SPC outlook discussion in a few hours. 

[Neoncyclone]

 

🤣🤣

Honestly though I don't know how I feel about Tuesday, there's no questioning the volatile atmosphere that will be in place, mainly questioning forcing as the cold-front is well behind and doesn't move into the area until the evening/overnight.

Edited April 3, 2023 by Neoncyclone

[ElectricStorm]

SPC upgrades the northern area to moderate including 15 hatched tornado area. 10 hatched for the southern enhanced risk

 

[Iceresistance]

8 hours ago, ElectricStorm said:

SPC upgrades the northern area to moderate including 15 hatched tornado area. 10 hatched for the southern enhanced risk

 

This is eerily similar to March 31st...

Edited April 3, 2023 by Iceresistance
Typo

[Hoosier]

Wednesday is starting to look a little more interesting around or just east of here.  Fropa timing seems to be inching slower.  I expect the severe threat to get going fairly early on Wednesday.