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Post by bdgwx on Jun 28, 2018 9:51:28 GMT -6
Well, I will say it wouldn't be the first time that an MCS ventured further than predicted. Remember July 19th, 2006? Yeah, we were no where close to the slight risk area that day and, in fact, some areas that got hit weren't even in the marginal risk (or whatever it was called back then). Just food for thought...
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Post by Chris Higgins on Jun 28, 2018 9:58:48 GMT -6
The CAMs are doing a terrible job resolving today's convective trends and convective potential...so old school methods will be king until they start to show something more closely resembling reality...which so far they are not.
There is now a well defined MCV/shortwave visible in satellite (visible and water vapor) cresting the top of the flat ridge and about to begin the downward slide on the eastern side of the ridge. The small, but potent complex tied to the MCV is surviving quite well within what will arguably be the most hostile environment of the day right now...with a warm ridge of mid-level temps immediately ahead of it...where 700mb temps on the latest SPC meso page show a rather toasty +14c! Yet the storm continues unabated. The air mass fueling the storm is extremely unstable with various CAPES running from 4500 to 6000+ over northwest MO depending on which flavor (ML, MU, SB). At this point...storms are definitely elevated...feeding off ML CAPEs from between 700 and 1000m up. Downstream over eastern MO...the air is not CURRENTLY as unstable due to overnight convection and lingering high clouds. But those clouds are clearing and temperatures will spike as the sun pops out in full force...leading to a corresponding rise in CAPE values ahead of the growing complex. In addition, mid-level temps cool some closer to the Mississippi River...so it would make sense that any drop subtle drop in instability will be compensated by cooler mid-level temperatures. Bottomline... the thermodynamics ahead of the complex remains supportive of severe storms with damaging wind and hail as the key threat.
The mean wind/steering flow/upwind propagation vectors all indicate a gradual turn more to the southeast with time is likely and the latest satellite and radar trends would seem to verify that as the past few frames of both are showing a developing southeastward surge. This will take the complex...and its severe potential southeast along the theta-e gradient right into the STL area late this afternoon. I suspect future SPC outlooks will expand the severe over eastern Missouri and one could argue the need for an upgrade as the potential for widespread wind damage within the line will be increasing in my opinion...if the system can maintain its current strength for another couple of hours.
EDIT...
One thing that may keep the storm moving more east than southeast is the track of the MCV/shortwave. Latest HRRR/MesoNAM show the vortex on a more east/southeast track...more towards Chicago...which could keep things a bit more to the north...with only the tail of the shortwave swiping the STL area later this evening.
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Post by Snowstorm920 on Jun 28, 2018 9:59:16 GMT -6
I think the chances probably are better that it falls apart but there is that outside chance it punches through and takes on a life of its own. That mid level warm air may melt it away just as easily though. We’re getting strong surface heating now which is like throwing nitrous on an already hot fire. This thing has so much energy to work with it’s ridiculous |
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Post by STGOutdoors on Jun 28, 2018 10:00:36 GMT -6
Well, I will say it wouldn't be the first time that an MCS ventured further than predicted. Remember July 19th, 2006? Yeah, we were no where close to the slight risk area that day and, in fact, some areas that got hit weren't even in the marginal risk (or whatever it was called back then). Just food for thought... Heck, the cluster a couple weeks ago from Iowa was supposed to disspate in Iowa. Made it all the way down and through southern MO if I recall. I remember really cheering that one on because it was getting quite dry. Edit - this was exactly two weeks ago today. |
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Post by Snowstorm920 on Jun 28, 2018 10:11:59 GMT -6
Radar is estimating the height of that storm ~60k feet
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Post by cozpregon on Jun 28, 2018 10:27:07 GMT -6
60mph winds up Atlantic (Cass County) IA.
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Post by Chris Higgins on Jun 28, 2018 10:28:57 GMT -6
Posting this shortly...  |
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Post by toddatfarmington on Jun 28, 2018 10:29:52 GMT -6
The CAMs are doing a terrible job resolving today's convective trends and convective potential...so old school methods will be king until they start to show something more closely resembling reality...which so far they are not. There is now a well defined MCV/shortwave visible in satellite (visible and water vapor) cresting the top of the flat ridge and about to begin the downward slide on the eastern side of the ridge. The small, but potent complex tied to the MCV is surviving quite well within what will arguably be the most hostile environment of the day right now...with a warm ridge of mid-level temps immediately ahead of it...where 700mb temps on the latest SPC meso page show a rather toasty +14c! Yet the storm continues unabated. The air mass fueling the storm is extremely unstable with various CAPES running from 4500 to 6000+ over northwest MO depending on which flavor (ML, MU, SB). At this point...storms are definitely elevated...feeding off ML CAPEs from between 700 and 1000m up. Downstream over eastern MO...the air is not CURRENTLY as unstable due to overnight convection and lingering high clouds. But those clouds are clearing and temperatures will spike as the sun pops out in full force...leading to a corresponding rise in CAPE values ahead of the growing complex. In addition, mid-level temps cool some closer to the Mississippi River...so it would make sense that any drop subtle drop in instability will be compensated by cooler mid-level temperatures. Bottomline... the thermodynamics ahead of the complex remains supportive of severe storms with damaging wind and hail as the key threat. The mean wind/steering flow/upwind propagation vectors all indicate a gradual turn more to the southeast with time is likely and the latest satellite and radar trends would seem to verify that as the past few frames of both are showing a developing southeastward surge. This will take the complex...and its severe potential southeast along the theta-e gradient right into the STL area late this afternoon. I suspect future SPC outlooks will expand the severe over eastern Missouri and one could argue the need for an upgrade as the potential for widespread wind damage within the line will be increasing in my opinion...if the system can maintain its current strength for another couple of hours. EDIT... One thing that may keep the storm moving more east than southeast is the track of the MCV/shortwave. Latest HRRR/MesoNAM show the vortex on a more east/southeast track...more towards Chicago...which could keep things a bit more to the north...with only the tail of the shortwave swiping the STL area later this evening. And the SPC pulls back the Slight Risk in NE MO www.spc.noaa.gov/products/outlook/day1otlk.html |
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Post by cozpregon on Jun 28, 2018 10:32:05 GMT -6
Looking at some of the sfc analysis... getting some decent pressure rises behind the MCS. Cold pool may be getting together.
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Post by Chris Higgins on Jun 28, 2018 10:34:38 GMT -6
Not sure why SPC would downgrade the risk for this area unless they are relying solely on the CAMS? Sorry, not going in that direction.
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Post by Chris Higgins on Jun 28, 2018 10:44:04 GMT -6
Iowa complex has rapidly become better organized will a well defined mesoscale circulation in the last 15 minutes noted on the radar.
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Post by STGOutdoors on Jun 28, 2018 10:46:02 GMT -6
Spc also pulled back the risk from our area Tuesday when we ended up having a couple tornado warnings (with qlcs tornado) and many severe thunderstorm warnings. So...not giving them a lot of credit here lately, sorry.
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Post by Snowstorm920 on Jun 28, 2018 10:51:24 GMT -6
That’s an interesting decision by the SPC to say the least. Every once in awhile they make a decision that makes you scratch your head
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Post by Snowstorm920 on Jun 28, 2018 10:52:55 GMT -6
They don’t even mention the Iowa complex in the discussion
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Post by cozpregon on Jun 28, 2018 10:54:19 GMT -6
Looks pretty healthy now |
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Post by Snowstorm920 on Jun 28, 2018 11:22:56 GMT -6
Hrrrr is slowly catching up and the latest run looks eerily similar to the 06 complex
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Post by STGOutdoors on Jun 28, 2018 11:37:56 GMT -6
Yea HRRR suddenly has it but delays the right turn making it a close call.
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Post by Snowstorm920 on Jun 28, 2018 11:40:20 GMT -6
Yea HRRR suddenly has it but delays the right turn making it a close call. Its initializing it further north that it truly is so keep that in in mind. Its just starting to see whats happening |
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Post by ajd446 on Jun 28, 2018 11:56:18 GMT -6
Talk about top fuel dragster airmass. I am currently 91 with dp of 81.
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lunchladyd
Junior Forecaster
On the Troy -Silex, Mo. line
Posts: 399 
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Post by lunchladyd on Jun 28, 2018 12:13:08 GMT -6
Severe thunderstorm watch for NE counties. Will it make it down here? Thats the question.
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Post by cozpregon on Jun 28, 2018 12:14:08 GMT -6
Des Moines Airport had 55+mph winds and the bulk of the storm missed them to the south.
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Post by amstilost on Jun 28, 2018 12:34:55 GMT -6
Sure seems like the bulk of the motion is due east, with an ever so slight southeast slant, with the complex in Iowa. HRRR sure makes a hard right as the complex exits Iowa.
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Post by Tilawn on Jun 28, 2018 12:45:13 GMT -6
 this is the definition of DISGUSTING!!! Going to be an early afternoon for me. Can’t handle this humidity this high anymore since I had severe heat exhaustion back a few years ago |
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Post by unclesam6 on Jun 28, 2018 13:00:53 GMT -6
One thing's for sure, that thing ain't goin to chi-town
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Post by guyatacomputer - NE St. Peters on Jun 28, 2018 13:04:37 GMT -6
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Post by Snowstorm920 on Jun 28, 2018 13:05:23 GMT -6
Looks like she'll be coming right down the river
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Post by Snowstorm920 on Jun 28, 2018 13:07:53 GMT -6
HRRR is really struggling again. These extreme instability days with modest shear always give the models fits
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Post by yypc on Jun 28, 2018 13:16:15 GMT -6
Cant decide if I want this thing to hit or not. If we lose power for an extended period it will be very uncomfortable.
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Post by mosue56 on Jun 28, 2018 13:42:51 GMT -6
Will this be called a derecho? Any idea how fast it’s moving?
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Post by ajd446 on Jun 28, 2018 13:44:23 GMT -6
How extreme is our instability right now
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