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GFS really slowing the s/w ejection for Saturday. Not liking the look of that.

Really? I think the latest run shows a much more ominous look for OK on Sunday evening. With a secondary surface lee cyclone forming over the TX panhandle, a coupled 250-mb jet structure, and backing SSE low-level winds maximizing hodographs...oh, and the 700-mb flow favors a weaker cap over OK by late-afternoon, peak diurnal heating. The GFS run this time would even hint at a major localized outbreak along the retreating warm front in N OK / S KS.

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Really? I think the latest run shows a much more ominous look for OK on Sunday evening. With a secondary surface lee cyclone forming over the TX panhandle, a coupled 250-mb jet structure, and backing SSE low-level winds maximizing hodographs...

 

There's no H5 flow faster than 30 kt east of the dryline at 00z. We were already treading a fine line with deep-layer shear, and if ithe trough slows much further, we go from outbreak talk to borderline supercell/multicell talk.

 

potent look on sunday for someone

 

Yep. Setting up for a crappy Ozarks/MS River event. 2013...

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potent look on sunday for someone

 

I-35 dryline day in OK if that happens.

 

This run continues to get a tad slower which might cause a problem or two the day before but makes Sunday look better further west in the plains.

 

So really could have potential Wed-Sun in the plains on this run where previous runs had it further east on Sunday.

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There's no H5 flow faster than 30 kt east of the dryline at 00z. We were already treading a fine line with deep-layer shear, and if ithe trough slows much further, we go from outbreak talk to borderline supercell/multicell talk.

 

 

Yep. Setting up for a crappy Ozarks/MS River event. 2013...

 

Well, with where Sunday sets up with this run, that's not exactly the Jungles completely, c'mon man.

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potent look on sunday for someone

Agree with this

There's no H5 flow faster than 30 kt east of the dryline at 00z. We were already treading a fine line with deep-layer shear, and if ithe trough slows much further, we go from outbreak talk to borderline supercell/multicell talk.

 

 

Yep. Setting up for a crappy Ozarks/MS River event. 2013...

Completely disagree with all of this.

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There's no H5 flow faster than 30 kt east of the dryline at 00z. We were already treading a fine line with deep-layer shear, and if ithe trough slows much further, we go from outbreak talk to borderline supercell/multicell talk.

Yep. Setting up for a crappy Ozarks/MS River event. 2013...

Sunday has looked better on 500 on a lot of runs. Tho this does no favors to Sat as you note.

I'm not sure it even matters but its weird it spins up a front running low that sits over the northeast.

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I-35 dryline day in OK if that happens.

 

This run continues to get a tad slower which might cause a problem or two the day before but makes Sunday look better further west in the plains.

 

So really could have potential Wed-Sun in the plains on this run where previous runs had it further east on Sunday.

 

Yeah this looks like it is trending toward the slower ejection similar to the Euro, it just might mean instead of Saturday being the big day, Sunday would be.

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There's no H5 flow faster than 30 kt east of the dryline at 00z. We were already treading a fine line with deep-layer shear, and if ithe trough slows much further, we go from outbreak talk to borderline supercell/multicell talk.

 

 

Yep. Setting up for a crappy Ozarks/MS River event. 2013...

 

post-266-0-94357500-1368505907_thumb.gif

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Sunday has looked better on 500 on a lot of runs. Tho this does no favors to Sat as you note.

I'm not sure it even matters but its weird it spins up a front running low that sits over the northeast.

I noticed that and I don't see it at all on previous runs.  Is that a possible reason for the slower ejection, or does it not have much impact?

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Agree with this

Completely disagree with all of this.

I'm not sure how you can disagree with a plot of H5 winds. Again, I was referring to Saturday, not Sunday.

 

BTW, I don't know where you guys are getting your data. IWM has crapped the bed lately, and it seems like NCEP is the only timely site, which doesn't have dew points (among other fields necessary for severe wx analysis).

 

Just got out to 00z Mon on RAP. The shortwave looks ill-timed to me WRT dryline potential. LLJ veers and outruns the instability axis, but could certainly see potential for IA/IL, etc.

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I noticed that and I don't see it at all on previous runs.  Is that a possible reason for the slower ejection, or does it not have much impact?

 

It looks like some convectively induced noise, I would be surprised to see it that on the next run.

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I'm not sure how you can disagree with a plot of H5 winds. Again, I was referring to Saturday, not Sunday.

 

BTW, I don't know where you guys are getting your data. IWM has crapped the bed lately, and it seems like NCEP is the only timely site, which doesn't have dew points (among other fields necessary for severe wx analysis).

 

Just got out to 00z Mon on RAP. The shortwave looks ill-timed to me WRT dryline potential. LLJ veers and outruns the instability axis, but could certainly see potential for IA/IL, etc.

 

Well Saturday is worse now but Sunday is better, either way it is not as bad as you are leading on.

 

weather.cod.edu is what website we are using for data.

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I'm not sure how you can disagree with a plot of H5 winds. Again, I was referring to Saturday, not Sunday.

 

BTW, I don't know where you guys are getting your data. IWM has crapped the bed lately, and it seems like NCEP is the only timely site, which doesn't have dew points (among other fields necessary for severe wx analysis).

 

Just got out to 00z Mon on RAP. The shortwave looks ill-timed to me WRT dryline potential. LLJ veers and outruns the instability axis, but could certainly see potential for IA/IL, etc.

 

COD, as fast or faster than NCEP now.

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Agreed about Saturday, and this has been a threat all along even when the GFS was progging a faster and slightly lower amplitude trough ejection, but UL flow is atrocious. Great looking difluent/negative tilt flow pattern for a broad region of WAA mass ascent, but not great in terms of deep layer shear even in the presence of nice clockwise low level hodographs largely driven by late season diurnal patterns across the plains. Haven't looked at Sunday yet...but I am guessing veering flow (which the GFS had previous runs) and uni-directional shear becomes more dominant. 

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Which ridge are you referring to? The one that Dsnow and I were referring to is the one in behind this system in the Eastern Pacific.

 

 

I am referring to the weak attempt at ridging ahead of the system. Stronger ridge would slow system down and push it farther north providing a better line up of ingredients. I was going on a different tangent from what ya'll were discussing.

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00z GGEM also comes in with a more amplified look from Saturday (looks better on Saturday than the GFS) to Tuesday, with a multitude of s/w's rotating around the base of the longwave trough. There are two primary sfc cyclogenesis events involved, one on Saturday and Sunday and the other for Monday and Tuesday.

 

For those who didn't see this link earlier: http://www.plainsweather.com/wxmap/model/

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Had a buddy point this out to me (Tim Marquis) and its a bit strange.  The GFS has some phantom bone dry air advecting north coming from TX as early as 12z Saturday.  This continues and seems to be why the instability is substantially lower in west KS near the dryline where the best shear is located.  Something seems weird and fishy about it to me, also... I don't think its realistic.  The air is not mixing back east after hour 60 and that's a bit strange.

 

GFS_3_2013051400_F108_DPTC_850_MB.png

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Too much hype for a multi-day event that doesn't look to do too much better than the last multi-day event.

 

Why so?

 

I think this has better potential for at least one of the days (it could really end up being any of them) than the last event. It certainly doesn't look as focused along the front with eastward extent, either.

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..SHORTWAVE TROUGH PRESENTLY NEAR THE CALIFORNIA COAST  
 
PREFERENCE: 2/3 NAM TO 1/3 ECMWF  
CONFIDENCE: ABOVE AVERAGE  
 
MODELS ARE IN AGREEMENT IN ALLOWING THE TROUGH TO REACH THE  
CENTRAL/SOUTHERN ROCKIES BY MIDDAY THURSDAY...BY WHICH TIME THE  
GFS ALLOWS FOR AN AREA OF CONVECTIVE GRID-SCALE FEEDBACK TO PHASE  
WITH THE LARGER TROUGH BEFORE ENTERING THE PLAINS...RESULTING IN  
GREATER EASTWARD MOVEMENT OF ITS ASSOCIATED DRYLINE BY 12Z FRIDAY.  
GIVEN AN ABSENCE OF SUPPORT FOR THIS SCENARIO AND THAT THE  
COURSER-GRIDDED GFS IS MORE PRONE TO SUCH ERRORS COMPARED TO THE  
HIGHER RESOLVING GUIDANCE...ITS SOLUTION IS DISCOUNTED.  
OTHERWISE...THE NAM/ECMWF HANDLE THE TROUGH COMPARABLY...WITH THE  
HIGHER RESOLVING NAM SLIGHTLY MORE PREFERRED THAN THE SLIGHTLY  
LESS RESOLVING ECMWF.  

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SW Kansas is still the place to be Saturday.  After talking to Tim more, I'm not buying the lower instability where the more impressive 0-500 mb bulk shear is located.  If you look at hour 72, you will see what we believe to be a garbage short wave in SW KS.  This anomalous wave is causing some sort of convective feedback in the models and spawning an unrealistic low in the TX panhandle.  This low advects dry surface air unrealistically... most likely causing the weird lack of moisture in SW KS after hour 60.

 

GFS_3_2013051400_F72_WSPD_500_MB.png

 

That short wave is simply not realistic, IMO and is causing all sorts of problems.  It was also present in the 18z run which also explains the issue there.  But on top of that, yes... Sunday north and east of OK City is looking pretty good.

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