Hoosier

2020 Short/Medium Range Severe Thread

Recommended Posts

15 hours ago, Stebo said:

7-7.5 c/km are not poor lapse rates, only the GFS is closer to 6.5 which is workable but also poorly underdone by a shitty model. 

At that point I had only looked at the GFS, given it was only GFS/Euro out far enough.

Share this post


Link to post
Share on other sites
55 minutes ago, Chicago Storm said:

At that point I had only looked at the GFS, given it was only GFS/Euro out far enough.

Come on man, GFS is always going to have shit lapse rates this far out due to model bias. 

  • Like 1

Share this post


Link to post
Share on other sites

This same 18z NAM run also ramps up tornado parameters along the warm front in eastern Ohio at the same time as well, as per this forecast sounding.  The NAM does not initiate precipitation in this area though, so it seems the threat there would be much more conditional if this run verifies.  Forecast parameters are lower in the area between E OH and IL.

Lapse rates on the 18z NAM run are also pretty high, with Plains-like 7.5-8.5 values from Illinois over into Ohio.

nam_2020032518_075_40.35--81.36.png

Share this post


Link to post
Share on other sites

With a 986mb low over Iowa, and 60-65F dew points from Louisiana up to Springfield IL/Davenport IA, I believe the SPC will have to give a slight risk outlook for the entire cold front and adjacent areas. Especially with 75 kt winds at 500mb over this region.

  • Like 1

Share this post


Link to post
Share on other sites
1 hour ago, Indystorm said:

This is much farther north from where SPC currently has a svr outlook.  Don't know if it's the NAM just being the NAM.

Think Broyles half-assed it per usual. 

Based on model data last eve the threat should have been much further north in coverage.  Later model data could change that, but based off the data he should have been looking at the threat area was poorly outlined.

  • Thanks 1

Share this post


Link to post
Share on other sites

The NAM is actually the worst model in the suite right now. I think the globals(particularly the UK) are painting a better setup. The primary difference between them and the NAM is the fact that the NAM is significantly faster

Share this post


Link to post
Share on other sites

Scary NAM forecast for the Calumet region for Sat. afternoon & eve using ye olde clown maps.  If NAM is slower it could be even more intense due to WAA.

IMAGE NOT FOUND

Share this post


Link to post
Share on other sites

Becoming interested in this setup.  I am always wary of the lake playing games with frontal position at this time of year but I think it will be ok here.  I'd say more uncertain with northward extent in northern IL.

  • Like 1

Share this post


Link to post
Share on other sites
6 hours ago, CheeselandSkies said:

He sounds uncharacteristically bearish on the Day 3 outlook. Doesn't even use the "T" word.

Yea he is being very conservative which is unlike him. Tornadoes were definitely worth mentioning. Slight risk areas should be bigger to especially up north

Share this post


Link to post
Share on other sites

Looking at morning NAM and GFS parameters today I would have to agree with Hoosier's post above that things all depend upon the strength of the lake influence wrt how far north that warm front is gonna go on Sat afternoon and evening.  There's gonna be a heck of a gradient and potential for svr storms between west central and ne Illinois though.

Share this post


Link to post
Share on other sites

New day 2 sees big expansion east of the marginal risk through most of the OV for hail.

Quote

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1243 PM CDT THU MAR 26 2020  
 
VALID 271200Z - 281200Z  

 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF  
EASTERN KANSAS AND ADJACENT WEST-CENTRAL MISSOURI...  
   
..SUMMARY
 
 
WIDESPREAD THUNDERSTORMS -- ALONG WITH POTENTIAL FOR MAINLY HAIL --  
ARE EXPECTED FROM EASTERN PORTIONS OF KANSAS EASTWARD ACROSS THE  
MIDWEST FRIDAY.  
   
..SYNOPSIS
 
 
A POSITIVELY TILTED UPPER TROUGH OVER THE INTERMOUNTAIN REGION IS  
EXPECTED TO ADVANCE STEADILY EASTWARD FRIDAY, GRADUALLY SHIFTING  
INTO THE PLAINS DURING THE SECOND HALF OF THE PERIOD. MEANWHILE,  
RIDGING WILL PREVAIL DOWNSTREAM OVER THE EASTERN HALF OF THE  
COUNTRY.  
 
AT THE SURFACE, WEAK LOW PRESSURE OVER THE CENTRAL/SOUTHERN HIGH  
PLAINS WILL BEGIN TO CONSOLIDATE OVER THE EASTERN COLORADO AREA  
DURING THE DAY, AND THEN SHOULD DEEPEN AND MOVE EAST/NORTHEAST  
ACROSS KANSAS LATE IN THE PERIOD. AS THIS OCCURS, A WARM FRONT  
EXTENDING EASTWARD ACROSS THE OHIO VALLEY AREA WILL DRIFT NORTHWARD,  
WHILE A COLD FRONT TRAILING FROM THE LOW ADVANCES ACROSS THE CENTRAL  
AND SOUTHERN PLAINS THROUGH THE END OF THE PERIOD.  
   
..EASTERN KANSAS VICINITY EASTWARD ACROSS THE MIDWEST
 
 
SHALLOW MOISTURE RETURN IS FORECAST ACROSS THE SOUTHERN PLAINS  
REGION AHEAD OF THE ADVANCING UPPER SYSTEM, BUT THE WARM SECTOR OF  
THE EVOLVING SURFACE CYCLONE IS EXPECTED TO REMAIN LARGELY CAPPED.  
WHILE A CONDITIONAL SEVERE RISK IS STILL EVIDENT OVER OKLAHOMA,  
POTENTIAL FOR SURFACE-BASED STORM DEVELOPMENT NOW APPEARS MINIMAL  
DUE TO THE CAPPING. GREATER POTENTIAL FOR A SURFACE-BASED STORM OR  
TWO IS APPARENT NORTHWARD INTO EASTERN KANSAS, AS THE SURFACE LOW  
ADVANCES TOWARD THIS AREA. HOWEVER, THE MAJORITY OF CONVECTIVE  
INITIATION -- FROM NORTHEASTERN KANSAS/MISSOURI/SOUTHERN IOWA  
EASTWARD ACROSS THE OHIO VALLEY WILL REMAIN ELEVATED, WITHIN A ZONE  
OF LOW-LEVEL WARM ADVECTION AIDING IN SUSTENANCE OF MODERATE  
MOST-UNSTABLE CAPE.  
 
GIVEN FAVORABLY STRONG FLOW ACROSS THE AREA, ORGANIZED/ROTATING  
STORMS WILL BE POSSIBLE LOCALLY, WITH POTENTIAL SPREADING EASTWARD  
ACROSS THE OHIO VALLEY WITH TIME OVERNIGHT. PRIMARY RISK WITH THE  
CONVECTION ACROSS THE ENTIRE REGION WILL BE HAIL, WITH  
LOW/CONDITIONAL RISK FOR STRONG WIND GUSTS AND POSSIBLY A TORNADO  
MOST APPARENT ACROSS WESTERN PORTIONS OF THE RISK AREA INTO  
KANSAS/NORTHEAST OKLAHOMA DURING THE EVENING.  
 
..GOSS.. 03/26/2020

 

swody2_categorical.png

Share this post


Link to post
Share on other sites

Continue to closely monitor Saturday for a potential local-ish chase.

There several things to like, but also several things to hate about the set-up at this point.

 

  • Like 2

Share this post


Link to post
Share on other sites

Storms moving at the speed of light would be number one regarding chasing. I do think there’s a pretty strong possibility this stays mostly discrete until the evening though.

Would maybe like to see a bit more turning in the lowest 3 km and a bit more instability, but I’m inclined to think that the arcing Pacific front/pseudo-dryline, in addition to the triple point in IA early on, should be a breeding ground for supercells. Tornado potential dependent on how the low level wind fields evolve (and how fast the deep layer cyclone occludes).

  • Like 4

Share this post


Link to post
Share on other sites

Very rare update to the current day 3.

Quote

DAY 3 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0353 PM CDT THU MAR 26 2020  
 
VALID 281200Z - 291200Z  

 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF  
IL/IN...AS WELL AS THE ARK-LA-MISS...  
   
..SUMMARY
 
 
SCATTERED SEVERE STORMS WILL BE POSSIBLE, MAINLY SATURDAY AFTERNOON  
AND EVENING, ACROSS MUCH OF THE MISSISSIPPI AND OHIO VALLEY REGIONS.  
A FEW TORNADOES, DAMAGING WINDS, AND LARGE HAIL WILL ALL BE  
POSSIBLE.  
   
..MS/OH VALLEY AREA
 
 
A DEEPENING SYNOPTIC CYCLONE WILL MOVE FROM NORTHEAST KS SATURDAY  
MORNING TO WI BY SATURDAY NIGHT, IN ADVANCE OF AN  
EJECTING/POSITIVE-TILT MIDLEVEL TROUGH. AN ELEVATED MIXED LAYER IN  
PRIOR DAYS SHOULD LIMIT THUNDERSTORM COVERAGE IN THE WARM SECTOR,  
AND ALLOW LOW-LEVEL MOISTURE TO SPREAD NORTHWARD INTO IL AND THE OH  
VALLEY, BENEATH THE REMAINING STEEP LAPSE RATE PLUME THROUGH THE DAY  
SATURDAY. ELEVATED CONVECTION WILL BE POSSIBLE THROUGH THE DAY INTO  
THE NORTHERN HALF OF THE OH VALLEY IN A WARM ADVECTION REGIME, AND  
ALSO ACROSS IA/WI IN THE ZONE OF STRONG ASCENT PRECEDING THE SURFACE  
CYCLONE AND MIDLEVEL TROUGH. LARGE HAIL WILL BE THE PRIMARY THREAT  
WITH THE ELEVATED STORMS.  
 
DURING THE DAY, SURFACE DESTABILIZATION IN ADVANCE OF THE COLD FRONT  
WILL CONTRIBUTE TO AN ENVIRONMENT FAVORABLE FOR THUNDERSTORM  
DEVELOPMENT ALONG THE FRONT BY EARLY AFTERNOON, ROUGHLY NEAR THE MS  
RIVER. POTENTIALLY MODERATE BOUYANCY (MLCAPE CLOSE TO 1000 J/KG)  
AND EFFECTIVE BULK SHEAR IN EXCESS OF 70 KT WILL FAVOR SUPERCELLS,  
WITH BROKEN BANDS OF CELLS EXPECTED GIVEN FAST STORM MOTIONS THAT  
WILL LIKELY EXCEED THE MOTION OF THE COLD FRONT. LOW-LEVEL SHEAR  
AND HODGRAPH CURVATURE WILL BE LARGEST ACROSS THE NORTHERN PART OF  
THE WARM SECTOR, WHERE A FEW TORNADOES WILL BE POSSIBLE, IN ADDITION  
TO DAMAGING WINDS/LARGE HAIL. THE FRONTAL CONVECTION WILL SPREAD  
EASTWARD THROUGH THE EVENING/OVERNIGHT INTO THE OH VALLEY, WITH SOME  
POTENTIAL FOR ISOLATED SEVERE WIND/HAIL AND PERHAPS TORNADOES.  
 
THERE IS SOME POTENTIAL FOR INCREASES IN SEVERE PROBABILITIES AND  
SOME EXPANSION OF THE NORTHERN SLIGHT RISK AREA IN LATER UPDATES.  
AREAS OF TN/KY WILL ALSO BE MONITORED FOR ANY INCREASE IN SEVERE  
THREAT WITH CONVECTION DEVELOPING NORTHEASTWARD OVERNIGHT FROM THE  
MID SOUTH. THE SOUTHERN SLIGHT RISK AREA REMAINS UNCHANGED IN THIS  
UPDATE, THOUGH THERE IS UNCERTAINTY REGARDING THE MAGNITUDE OF THE  
SEVERE THREAT THIS FAR SOUTH.  
 
..THOMPSON.. 03/26/2020  
 

 

swody3_categorical.png

  • Weenie 1

Share this post


Link to post
Share on other sites

The Day 4-8 left something to be desired, as well RE: next Tuesday in Dixie; usually even with model disagreement the man is gung ho as can be if there's any potential at all.

Share this post


Link to post
Share on other sites
3 minutes ago, Hoosier said:

I don't remember ever seeing an afternoon update on a day 3 outlook. 

I can remember about 3 and every single one of them ended up being significant events. This one is no different in my opinion either.

  • Like 2
  • Weenie 1

Share this post


Link to post
Share on other sites
2 minutes ago, Stebo said:

I can remember about 3 and every single one of them ended up being significant events. This one is no different in my opinion either.

Y'all have better memories than me. :P  Were they Plains or Dixie setups?  I couldn't remember one that was focused more in our region. 

Share this post


Link to post
Share on other sites
1 hour ago, snowlover2 said:

Very rare update to the current day 3.

 

swody3_categorical.png

Beat me to it, just got home and seen that. I know better than to get my hopes up, but 3 straight days in a Mrgl or Slight. Still haven't heard thunder this year.

  • Like 1

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

  • Recently Browsing   0 members

    No registered users viewing this page.