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Post by jmg378s on Apr 28, 2020 9:23:04 GMT -6
Another factor here is that meso models have a bit more line normal shear orientation than the global models (relative to a presumptive southeast moving QLCS). That subtle difference, if that's the way it plays out, could also help sustain updrafts and some line embedded circulations.
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Post by BRTNWXMAN on Apr 28, 2020 9:23:24 GMT -6
The rpm is actually showing a couple of loop type signatures running along and South of inter state 70... With embedded supercell structures. That wouldn't surprise me. We should keep an eye on surface wind trends today too...any backing will greatly increase the tornado risk. |
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Post by cozpregon on Apr 28, 2020 9:29:17 GMT -6
One thing about this set up that I find curious and may play a factor is that the shear values are not off the charts. That may play more in the favor of storms because updrafts will not be getting torn apart... As it stands right now it looks to me like there is a healthy balance between the bulk sheer and the degree of instability. Short term models have the BRN in the low 20s... which is close to ideal. |
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Post by Snowstorm920 on Apr 28, 2020 9:42:15 GMT -6
A snippet from this morning disco: The main concern in the short term continues to be the severe weather chances across the region this afternoon through this evening. HREF probabilities of surface based CAPE greater than 1000 J/kg remain well over 90 percent between 18z and 00z Wednesday, especially for portions of central/northeast MO and west central IL, with bulk shear between 30 and 35 kts. However, several of the deterministic models have the associated surface low a bit further north with the 00z run, so could see our area between the stronger dynamics to our north and better instabilities to our south. For now will keep similar timing with pre-frontal discrete cells developing by 21z, then activity will evolve into more linear convection through the evening as front slides south across forecast area, exiting by 04z Wednesday. Main threats will be large hail, damaging winds, and a few tornadoes possible with pre-frontal supercells. Have we seen that before?? 🤔 You can copy and paste that for almost every severe episode around here |
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Post by Snowstorm920 on Apr 28, 2020 9:48:09 GMT -6
Depending on which model you look at there are some messy looking hodographs with plenty of veer back in the profile here this evening. The critical angle and 0-3km cape look awfully good though
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Post by Snowstorm920 on Apr 28, 2020 10:36:28 GMT -6
SPC moved the enhanced risk into the western counties for a 30% wind risk. The 5% tornado risk also now covers most of the area  |
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Post by toddatfarmington on Apr 28, 2020 10:36:44 GMT -6
Watch those Tds this afternoon... if we can get the mid 60s like the models suggest- I think severe threat will certainly be there. I was actually thinking they may need to pull the enhanced area a bit further north with the morning update. And right on cue ...., |
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Post by cozpregon on Apr 28, 2020 11:42:10 GMT -6
Can see that jet max diving into NE KS  |
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Post by Chris Higgins on Apr 28, 2020 11:59:07 GMT -6
Tds are definitely on the way up!
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Post by BRTNWXMAN on Apr 28, 2020 12:07:36 GMT -6
Tds are definitely on the way up! This airmass definitely has that feel...ample destabilization underway. |
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Post by Snowman99 on Apr 28, 2020 12:31:48 GMT -6
It do be warm and bit muggy.
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Post by BRTNWXMAN on Apr 28, 2020 12:34:01 GMT -6
Pretty cool looking system...don't often see two well defined comma heads that close together.  |
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Post by Snowstorm920 on Apr 28, 2020 13:05:46 GMT -6
Wonder if we won’t see a rare PDS severe thunderstorm watch around Tulsa later
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Post by WEAXWATCHER on Apr 28, 2020 13:35:11 GMT -6
My backyard station says its 81* and DP is 61*. Feels dry. It's a gorgeous day outside! About to mow and have an adult beverage or three.
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Post by Jeffmw on Apr 28, 2020 13:38:48 GMT -6
Still around guys just keeping an eye on things.
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Post by WEAXWATCHER on Apr 28, 2020 13:58:19 GMT -6
LSX just tweeted wind and hail, no mention of tornadoes.
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Post by Chris Higgins on Apr 28, 2020 14:09:05 GMT -6
Had a viewer email today and ask why I keep saying "hail and wind are main concerns...but I cannot rule out a tornado" There are a couple of reasons...
#1, it is true... you cannot rule out a tornado today.
#2, 100% of the time when I don't mention tornadoes... people follow up with "what about tornadoes?" So why wait to be asked.
#3, I never want to speak in absolutes about tornadoes. I will never say "no way" because that is a sure fire way to get a suprise tornado and have people start pointing fingers..and heaven forbid...get somebody hurt.
Easiest way to attack all of those is to qualify with "Tornadoes are the least concern... but cannot rule one out." Boom done.
Just finished virtual classroom visit #27...Only 50 more to go!
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Post by WEAXWATCHER on Apr 28, 2020 14:10:29 GMT -6
Storms are firing from Mound City through Harrisburg
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Post by cozpregon on Apr 28, 2020 14:12:49 GMT -6
CU seems to be getting agitated... and virtually no cap. May start seeing some popups ahead of the line  |
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Post by WEAXWATCHER on Apr 28, 2020 14:14:42 GMT -6
Had a viewer email today and ask why I keep saying "hail and wind are main concerns...but I cannot rule out a tornado" There are a couple of reasons... #1, it is true... you cannot rule out a tornado today. #2, 100% of the time when I don't mention tornadoes... people follow up with "what about tornadoes?" So why wait to be asked. #3, I never want to speak in absolutes about tornadoes. I will never say "no way" because that is a sure fire way to get a suprise tornado and have people start pointing fingers..and heaven forbid...get somebody hurt. Easiest way to attack all of those is to qualify with "Tornadoes are the least concern... but cannot rule one out." Boom done. Just finished virtual classroom visit #27...Only 50 more to go! I wasnt bashing, Chris, I was wondering why not say "A tornado or two cannot be ruled out". The general public doesn't know where to find the disco. I know the threat is there, just find it odd that the LSX office didnt mention it on social media. You know as well as any of us... it is the number one place to find info and first place to lay blame. I also understand that it's bad if it is over stated. Please dont misunderstand my post. |
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Post by demerson- Fletcher MO on Apr 28, 2020 14:19:10 GMT -6
Popping fast! That line came outa nowhere
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Post by unclesam6 on Apr 28, 2020 14:21:23 GMT -6
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Post by Chris Higgins on Apr 28, 2020 14:33:22 GMT -6
Had a viewer email today and ask why I keep saying "hail and wind are main concerns...but I cannot rule out a tornado" There are a couple of reasons... #1, it is true... you cannot rule out a tornado today. #2, 100% of the time when I don't mention tornadoes... people follow up with "what about tornadoes?" So why wait to be asked. #3, I never want to speak in absolutes about tornadoes. I will never say "no way" because that is a sure fire way to get a suprise tornado and have people start pointing fingers..and heaven forbid...get somebody hurt. Easiest way to attack all of those is to qualify with "Tornadoes are the least concern... but cannot rule one out." Boom done. Just finished virtual classroom visit #27...Only 50 more to go! I wasnt bashing, Chris, I was wondering why not say "A tornado or two cannot be ruled out". The general public doesn't know where to find the disco. I know the threat is there, just find it odd that the LSX office didnt mention it on social media. You know as well as any of us... it is the number one place to find info and first place to lay blame. I also understand that it's bad if it is over stated. Please dont misunderstand my post. Oh.. I know you weren't... lol. I was just sharing the story from earlier today... and explaining why I do what I do. Not sure why NWS made no mnetion... maybe to keep focus on other two I guess. |
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Post by Chris Higgins on Apr 28, 2020 14:35:53 GMT -6
Watching area between Hermann and Lebanon MO... seems to be a weak convergence zone there at the surface...and some agitated cu. May get some developement there ahead of the main show. CAMs have shown some at times.
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Post by cozpregon on Apr 28, 2020 14:35:58 GMT -6
Saw that on facebook... the 4th question to that post was "what about tornadoes are they still a threat"
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Post by Snowstorm920 on Apr 28, 2020 14:36:49 GMT -6
Mesoscale Discussion 0485
NWS Storm Prediction Center Norman OK
0333 PM CDT Tue Apr 28 2020
Areas affected...eastern Missouri...southeast Iowa...into western
Illinois
Concerning...Severe potential...Watch likely
Valid 282033Z - 282200Z
Probability of Watch Issuance...95 percent
SUMMARY...Severe thunderstorms with the potential for damaging wind
gusts and large hail with a tornado or two will be likely this
afternoon and evening.
DISCUSSION...Mid-level ascent from an approaching shortwave trough
over the central High Plains is impinging on the warm sector of a
surface cyclone over southern Minnesota and northern Iowa. Boundary
layer moisture has increased through the day across Missouri and
southern Illinois with surface dewpoints in the upper 50s into the
low 60s F. As a result of the moistening, 1000-2000 J/kg of MLCAPE
has developed across the area. The instability is concurrent with
effective bulk-shear of 30 to 40 kt. Severe storms including a mix
of line segments and a few supercells are likely to develop over the
next 1 to 2 hours along the surface trough/cold-front trailing the
surface low. Initially, these storms will pose a risk for a tornado
or two but will transition to a damaging winds and hail threat.
..Lyons/Cook/Thompson.. 04/28/2020
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Post by cozpregon on Apr 28, 2020 14:45:08 GMT -6
Just looks cool  |
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Post by mosue56 on Apr 28, 2020 14:56:30 GMT -6
How big
Is the thunderstorm watch? We are in Bonne Terre today!
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Post by ElKay23 - Columbia, IL on Apr 28, 2020 15:07:26 GMT -6
How big Is the thunderstorm watch? We are in Bonne Terre today!  |
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Jeke
Junior Forecaster
Old Jamestown, MO
Posts: 320 
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Post by Jeke on Apr 28, 2020 15:08:41 GMT -6
Hope this helps...
IN EAST CENTRAL MISSOURI
CRAWFORD FRANKLIN GASCONADE
JEFFERSON LINCOLN MONTGOMERY
SAINT CHARLES SAINT LOUIS SAINT LOUIS CITY
WARREN WASHINGTON
IN NORTHEAST MISSOURI
MARION MONROE PIKE
RALLS
THIS INCLUDES THE CITIES OF ALTON, BELLEVILLE, BOWLING GREEN,
CAHOKIA, COLUMBIA, EDWARDSVILLE, FULTON, HANNIBAL,
JEFFERSON CITY, LITCHFIELD, MEXICO, MOUNT STERLING, PITTSFIELD,
QUINCY, SAINT CHARLES, SAINT LOUIS, SULLIVAN, UNION,
AND WASHINGTON.
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