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Post by jmg378s on Jun 29, 2019 8:08:34 GMT -6
What does the MCV mean in weather? I see it and think Mean Corpuscular Volume. Yay red cells! It stands for mesoscale convective vortex. It's a smaller low pressure / spin aloft, or wake low, that results from latent heat release and/or vorticity that develops north of a rear inflow jet of a long lived complex of thunderstorms. Remnant MCVs are known to be able to kick off new batches of thunderstorms like on Wednesday. MCVs themselves can produce severe weather too; perhaps the most notable case was the "Super Derecho" of 2008 that tracked through Missouri. It's also been referred to as the "inland hurricane" due to the eye-like feature that developed and the 100+ mph straight line winds it produced. |
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Post by Chris Higgins on Jun 29, 2019 9:40:21 GMT -6
This past week has been among the most challenging summer weeks of forecasting I can remember...and as a whole...I think the entire weather enterprise failed. This week, perhaps more than any other in recent memory, showed how reliant we have become on following model simulated radar. The problem is... it has become quite good at times...and quite terrible at others. It is accurate just enough to suck you in...and make it difficult to ignore...even when other signals are telling you a different story. Early this week I was pulled into the model madness...but I quickly realized I was hyper-analyzing mesoscale fantasy. Trying to get too specific. So I stopped looking at meso products almost altogether. Instead... I tried to really dig into just 500mb and 700mb charts...ignoring altogether the radar output. That ended up being the most effective...except that the shortwaves within those flows were showing significant impacts/feedback from the surface developments/MCSs and resulting MCS. A shortwave that was clearly evident for 3 days from now...vanished on the next run... or was so far misplaced in time/space it was difficult to decipher what feature you were tracking.
What stood out early on was the fact that mcv/vort maxes were going to be falling off the ridge and getting tucked back to the south and southwest. I mentioned itnearly this week...and Fish even brought up his concerns in a AFD early in the week. However, timing those events was fools play. The lack of specifics lead at one point to a 7 day forecast plastered with spot storm chances almost every day....I hate that. So I tried to wean them out were I could...but my attempts to better time were not so good. Tuesday night's storms turned into Wednesday afternoon storms...and Friday storms were pulled entirely because I pushed then to fri night or sat AM. It has been an aweful mess. I. the end... there has been much more dry time than wet...and temperatures have been increasing...along with humidity. So the big picture stuff has been a good news story. But the specifics of timing and location have been a diaster...on almost every level. If I have one truly positive thing to take away from this week... it was the ability to course correct the forecsst the day of in the morning. The Wed AM forecast made reasonable adjustments to account for expected afternoon activity...even if my forecast from the day before was not so good. The same for yesterday. I felt good about the adjustments that were made as the system evolved in the AM...and especially with my handoff to Jaime where we opted (well before the NWS) to go all in on storm potential for Friday afternoon.
Sorry for the rambling message...it has just been a tough week.
Time to celebrate my son's birthday!
Have a good weekend all.
Chris
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Post by mosue56 on Jun 29, 2019 9:59:09 GMT -6
Tell him, the happiest of birthdays from all of us in Chris' Corner! Thanks, Chris! Try to have some fun and also rest! That's what weekends are for!
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Post by jeffcobeeman on Jun 29, 2019 13:45:23 GMT -6
Beautiful weather down here at Tablerock Lake. Springfield Cardinals game last night was great, but a bit hot and humid until the sun set.
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Post by Chris Higgins on Jun 29, 2019 14:16:49 GMT -6
Unusual to so clearly see what amounts to sea/river breaze convergence zones showing up on radar this afternoon near downtown. I am not sure I have ever seen it so clearly.
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Post by cozpregon on Jun 29, 2019 14:35:41 GMT -6
Eastern edge of the extreme CAPE is uncapped and seeing some scattered development. Likely to remain scattered/diurnal but if it does get organized it may be something to watch later.  |
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Post by jmg378s on Jun 29, 2019 18:02:15 GMT -6
21z special sounding from Aberdeen, SD is jussssst a bit unstable...  |
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Post by BRTNWXMAN on Jun 29, 2019 19:06:01 GMT -6
I was going to mention Fish's FD from earlier in the week. Mr. Sieveking did a great job outlining the posibilities of outflows throwing a wrench in the gears and he nailed it. It's been a chaotic week of weather for sure...
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ilnois
Wishcaster
Columbia, IL
Posts: 123
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Post by ilnois on Jun 29, 2019 19:21:04 GMT -6
Any thoughts on whether the Camping World 400 in Joliet IL will
be delayed tomorrow?
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Post by Snowman99 on Jun 30, 2019 3:54:45 GMT -6
Looks like the MSC up in MN is going to dive south. How far south and west will it go? NWS has added slight chance for this evening. Slight risk for a good chunk of IL.
Everyone place your bets on how far south and west it gets..or relative of it.
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Post by Chris Higgins on Jun 30, 2019 9:21:55 GMT -6
I think we are fine today. Complex #1 is really suffering the affects of its interaction with the ridge...and being directed more to the east. However, this lead complex will take a bite out of the ridge crest...making it easier for complex #2 to crash more south late today into tonight. I am more interested in that second complex up near Minneapolis at this stage of the game.
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Post by Snowstorm920 on Jun 30, 2019 10:12:26 GMT -6
Models won’t be much help again today. Going to have to watch radars trends closely.
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Post by ComoEsJn on Jun 30, 2019 12:41:05 GMT -6
round 2 seems to so far be following behind round 1, if I'm looking at it right.
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Post by ndolan387 on Jun 30, 2019 13:17:03 GMT -6
We are going to see the remnants of Alvin later this week. It will interesting to see how much rain that will produce in our neck of the woods. Also to add to the rainfall totals, the jet stream is shifting far south this week so it will become unsettled thus we will get more organized fronts and storms. We have to keep an eye on the small tributaries and of course the major rivers in the coming weeks, months (hopefully not to the end of the year)! Otherwise, if we don't get any rain today KSTL will finish with 4.66" for June (the wettest month out of the year climatology speaking). The normal is 4.28" so only 0.38" above average. Though we have had frequent days with rain as you all know firsthand. Now we will have to see how the summer season shapes up as a whole because the spring season was impressive when it came to rainfall totals! It would even more impressive if the summer season rivals the rainfall totals (back to back). Let's hope not!!
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Post by cozpregon on Jun 30, 2019 14:05:54 GMT -6
round 2 seems to so far be following behind round 1, if I'm looking at it right.
The first MCS is cleaning up the CAPE across IL... the second one should come in further west along the big CAPE across IA- question for me is will this maintain itself into the night time hours.
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Post by guyatacomputer - NE St. Peters on Jun 30, 2019 14:12:15 GMT -6
And they are both doing some building along the line to the west; the second line more so than the first.
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Post by Snowstorm920 on Jun 30, 2019 14:17:19 GMT -6
Pretty good cold pool diving south across IL. Have to think the outflow will make it here
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Post by BRTNWXMAN on Jun 30, 2019 14:30:34 GMT -6
Pretty good cold pool diving south across IL. Have to think the outflow will make it here That's what I'm thinking too but mid-level temps are fairly toasty and increasing CIN may play a role after sunset...thinking a weakening trend will occur as storms advect/back build into the region this evening. |
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Post by cozpregon on Jun 30, 2019 17:04:04 GMT -6
That line up in Iowa is impressive- 76mph at DBQ
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Post by cozpregon on Jun 30, 2019 17:18:22 GMT -6
Big cold pool behind that-
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Post by Snowstorm920 on Jun 30, 2019 17:21:04 GMT -6
Big cold pool behind that- Think it will make it here? I have my doubts |
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Post by ajd446 on Jun 30, 2019 17:27:38 GMT -6
Why do we not have a heat advisory I believe we have hit 100 plus heat indices for 4 days now. Just curious. Thanks
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Post by cozpregon on Jun 30, 2019 17:27:40 GMT -6
There’s some decent MLCape here- 2000j/kg... nothing like up in IA though. If the cold pool can maintain itself there’s a chance
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Post by cozpregon on Jun 30, 2019 17:30:23 GMT -6
There’s some good convection in the cold pool now- that helps to enhance it
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Post by yypc on Jun 30, 2019 17:33:22 GMT -6
Why do we not have a heat advisory I believe we have hit 100 plus heat indices for 4 days now. Just curious. Thanks I thought it was 105 heat index needed here. 100 heat index is fairly common in the summer. |
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Post by ajd446 on Jun 30, 2019 17:38:14 GMT -6
Its 100 for 4 consecutive days.
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Post by guyatacomputer - NE St. Peters on Jun 30, 2019 17:41:32 GMT -6
That line near Davenport is definitely developing a south, and even a bit of a southwest movement to it. Will it fizzle once it loses the heating of the day or will it continue that movement towards STL after dark?
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BDS
Wishcaster
Columbia, MO
Posts: 202 
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Post by BDS on Jun 30, 2019 18:23:49 GMT -6
Why do we not have a heat advisory I believe we have hit 100 plus heat indices for 4 days now. Just curious. Thanks Lambert didn't hit 100 HI yesterday or the day before. Only Chesterfield hit 100 HI two days ago. Didn't reach it today. |
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Post by John G -west belleville on Jun 30, 2019 19:13:00 GMT -6
Look at the Western flank just collapse
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Post by guyatacomputer - NE St. Peters on Jun 30, 2019 19:20:21 GMT -6
Look at the Western flank just collapse |
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