May 7-28, 2022 | Severe Weather/MCS Sequence

[ClicheVortex2014]

Finally down to just one severe warning but woooow. 55 unfiltered significant wind reports at the end of the day.

 

GEFS and EPS have a pattern that would warrant suspicion for a very active severe weather pattern at any time of year... but this is coming in the peak of the tornado season.

Edited May 13, 2022 by ClicheVortex2014

[ElectricStorm]

Crazy derecho, definitely would have verified as a 60 hatched wind risk but it's tough to know exactly how these MCS events are going to play out so I can definitely see why they kept it at 45. The only good thing about today was the strong tornado threat never materialized but that doesn't matter much when the MCS is basically a Cat 1 hurricane moving through. Wind threat definitely reached its max potential today unfortunately. 

[StormfanaticInd]

Next week might finally get active in the OV. I think 🙄

[Guest]

Dirty 30’s black skies you hear about.

 

[Guest]

On the news just now:

169 damaging wind reports.  59 and counting of reports of 75mph+.  Just said it’s the 2nd most in a single storm in the US since 2004.

Edited May 13, 2022 by SoDakFarmer

[Guest]

Compilation mostly from Castlewood.  https://www.gowatertown.net/galleries/severe-weather-photos-5-12-22/

All pics are clickable for full size.

Edited May 13, 2022 by SoDakFarmer

[FortySixAnd32]

https://www.foxweather.com/watch/play-5a7ec90a100049b

 

[ClicheVortex2014]

I guess my comparison to the setup on 12/15/21 wasn't far off. How the hell do we have 2 of the most significant derechos on record (at least by the standard of number of significant wind reports) happen within 6 months of eachother? 

Edited May 13, 2022 by ClicheVortex2014

[1816]

27 minutes ago, ClicheVortex2014 said:

I guess my comparison to the setup on 12/15/21 wasn't far off. How the hell do we have 2 of the most significant derechos on record (at least by the standard of number of significant wind reports) happen within 6 months of eachother? 

I know this guy with a weather site who has some pretty strong opinions about why 🤣

[ClicheVortex2014]

10 minutes ago, 1816 said:

I know this guy with a weather site who has some pretty strong opinions about why 🤣

Can't go wrong with that. Sounds reliable

Edit: just realized who you're referring to, though to be fair it could've applied to a lot of people 😄

Edited May 13, 2022 by ClicheVortex2014

[TLChip]

43 minutes ago, ClicheVortex2014 said:

I guess my comparison to the setup on 12/15/21 wasn't far off. How the hell do we have 2 of the most significant derechos on record (at least by the standard of number of significant wind reports) happen within 6 months of eachother?

How often do those produce severe wind speeds over 75+?  
I remember reading about a few with winds over 100, that’s incredible. Saw 114 on the radar but that was pretty high up. 

[ClicheVortex2014]

7 minutes ago, TLChip said:

How often do those produce severe wind speeds over 75+?  
I remember reading about a few with winds over 100, that’s incredible. Saw 114 on the radar but that was pretty high up. 

Usually to be called a derecho, it requires at least 3 spread out >75 mph wind gusts within the MCS lifespan. Usually only maybe half a dozen such MCSs meet that criteria per year... sometimes more, sometimes less. So derechos are pretty rare because it's pretty rare to have an MCS that produces widespread damaging winds AND high-end damaging winds. But to have over 50 such reports is extremely rare... not to mention multiple measured 100+ mph wind gusts are within those. 

Yeah the 100+ mph winds shown on radar were like 1000-2000 feet above ground, and they might've resulted in some of the 100+ mph surface gusts. That's certainly not something you see with every derecho.

Edited May 13, 2022 by ClicheVortex2014

[TLChip]

Oh that makes more sense I thought they started at 55+. I only remember one off the top of my head and it was the PA 2020 (500+mile I think it traveled.) 

We had 82mpg gusts recorded in our county and the power grid was down for 5 days imby.

[ClicheVortex2014]

38 minutes ago, TLChip said:

Oh that makes more sense I thought they started at 55+. I only remember one off the top of my head and it was the PA 2020 (500+mile I think it traveled.) 

We had 82mpg gusts recorded in our county and the power grid was down for 5 days imby.

"Damaging winds", i.e. winds that meet severe tstorm warning criteria, starts at 55 knots... so maybe that's where you got the 55 number from. But 75+ mph gusts are considered 'significant' and are denoted on SPC storm reports maps by a square rather than a blue triangle(?)

If it weren't for the significant wind requirement, there'd be dozens of derechos per year. Basically just synonymous with MCS because widespread damaging winds from MCSs are pretty common in the summer and sometimes winter with high shear/low cape setups.

Derechos are pretty rare in the vicinity of/east of the Appalachians because you need, not just strong/extremely unstable conditions, but steep lapse rates aloft to really help air parcels accelerate. The dry air with the EML also helps speed up evaporation which adds to the wind potential. To get that you need to be close to a source region or in a favorable pipeway to get it... and that source region is either Mexico or the intermountain West... Arizona/New Mexico, Colorado, Wyoming, even Montana sometimes.

It happens in the East probably more often than most are aware I think, but I don't think this magnitude of derecho has been observed in recorded history there. Probably did at some point in North American history that we'll never know about

Edited May 13, 2022 by ClicheVortex2014

[ClicheVortex2014]

GFS in a nutshell the past 2 days between severe weather and... this

 

[snowlover2]

18 minutes ago, ClicheVortex2014 said:

GFS in a nutshell the past 2 days between severe weather and... this

 

GFS brings that tropical system up this way on that run.

[ClicheVortex2014]

Now up to 64 significant wind reports from yesterday. This ties 12/15/21. However... filtered significant wind reports for 12/15/21 was 57. Yesterday has 52 so far. That means the significant wind reports are more clustered than 12/15 which isn't much of a surprise when you look at the below images

Edited May 13, 2022 by ClicheVortex2014

[StormfanaticInd]

Saturday and Sunday severe risk for my area kind of snuck up on me

[StormfanaticInd]

Some slow moving storms northwest of St. Louis 

 

Edited May 14, 2022 by StormfanaticInd

[ClicheVortex2014]

13 minutes ago, StormfanaticInd said:

Saturday and Sunday severe risk for my area kind of snuck up on me

Not to burst your bubble but I won't be surprised to see both days being a marginal risk for our area. Granted, we haven't got much this year so anything is welcomed. But with the way the focus shifted from the Southeast to the Plains so quick this year, I think it's only a matter of time until we've had enough.

Edited May 14, 2022 by ClicheVortex2014

[StormfanaticInd]

2 minutes ago, ClicheVortex2014 said:

Not to burst your bubble but I won't be surprised to see both days being a marginal risk. Granted, we haven't got much this year so it'll be nice. But with the way the focus shifted from the Southeast to the Plains so quick this year, I think it's only a matter of time until we've had enough.

Yeah, it's been a lot quieter than what I would have thought for us in the OV this spring 

[ClicheVortex2014]

22 minutes ago, StormfanaticInd said:

Yeah, it's been a lot quieter than what I would have thought for us in the OV this spring 

Seems it's been pretty hit-or-miss since 2012. I thought the second straight La Nina year would be different but I guess not. Mother Nature just decided to be super obedient to climatology this year I guess. Would really help out us Meteorologists if this happened on a more consistent basis but it's cool

Edited May 14, 2022 by ClicheVortex2014

[ClicheVortex2014]

I'm happy to see HRRR has something for western Ohio tomorrow. Fingers crossed. It's been way too warm lately for May and for this lack of storms.

[snowlover2]

ILN thought for today and tomorrow and also hinting at possible severe on Wednesday night.

Quote

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
649 AM EDT Sat May 14 2022

.SYNOPSIS...
After a recent stretch of quiet weather, the pattern will turn a
bit more active through this weekend, with chances for showers
and storms this afternoon and again Sunday night. Slightly
cooler and drier air filters in for the start of the workweek
before additional chances for storms arrive midweek and beyond
as warmer and more humid air returns to the area.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Our wonderfully quiet stretch of weather that has evolved over
the better part of the last 5 to 6 days seems to be coming to a
close, at least somewhat.

Slightly more humid air has built into the region over the past
12 hours or so, with DPs generally in the upper 50s and lower
60s area-wide. Aloft, the closed low that had meandered about
the SE CONUS for the past several days has transitioned to an
open wave as it becomes absorbed into the main quasi-westerly
flow through the Appalachians. That feature will continue to
pull E of the OH Vly during the day as a weak midlevel S/W
pivots E into the western OH Vly by this afternoon. With the
increased LL humidity leading to slightly more substantial LL
instby, this feature will provide a focus for weak lift amidst a
largely-uncapped profile, promoting the development of ISO/SCT
SHRA/TSRA by mid afternoon and beyond, especially for western
parts of the local area where coverage will be a bit more
widespread.

There are several questions that still remain as we progress
through the day today -- most notably the degree of mixing down
sfc DPs during peak heating and the impact that would/could
have on our TSRA coverage and placement. It should be noted that
the LL and deep-layer shear are both incredibly weak. Today`s
setup is one that is much more reminiscent of a summer pulse
convection day, with updrafts going up, but unable to be
sustained for any notable period of time, and thus quickly
collapsing and gusting out, promoting renewed
updrafts/convection on the periphery of the outflows. So
although there is some weak westerly steering-layer flow, the
propagation of the convection will be guided by a frequent
renewal of updrafts along propagating outflows. The primary
concern today with any more robust updraft will be gusty to
isolated/very spotty damaging winds when the core inevitably
collapses without much shear to work with. Fcst soundings show
DCAPE on the order of 800+ J/kg developing near/west of I-75 by
21z with the steepening of LL lapse rates as depicted on our
inverted-V fcst soundings. There are, however, uncertainties
regarding updraft strength and maintenance with only very meager
deeper-layer shear to work with. The updrafts could self-
destruct before having a chance to get tall enough for a long
enough period of time to create concerns upon collapse. So this
is probably a scenario where we will see divergent signatures on
radar when the cores collapse, but just how strong those are
and how gusty the winds will be, remains to be seen. A few
instances of damaging wind cannot be completely ruled out, but
do think this will be very isolated in nature, if it occurs at
all. Will maintain mention in HWO for isolated instances of a
strong/gusty winds.

The convection today will be primarily diurnally-driven,
although suppose that new updrafts will continue to fire along
propagating outflows/boundaries late into the evening until the
SBCIN becomes too great to overcome as the larger-scale lift
will still be relatively weak.

Highs today will again reach into the lower 80s. With a bit more
cloud cover expected this afternoon, do think that temps will
generally be a degree or two cooler than has been the case the
past several days.

Cloud cover will wane late this evening as the convection
gradually dies off.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
The environment will quickly stabilize very late this evening
after sunset in the wake of convection as it shifts to the SE
of the ILN FA and the area gradually clears out. Subsidence in
the wake of the S/W energy will promote some clearing late
tonight. In areas which receive appreciable rainfall during the
day, some patchy fog may develop as the LL wind flow once again
becomes light/VRB/calm. This would only be favored in areas
where appreciable LL moisture is present (such as in river
valleys and where the ground is still saturated/wet from earlier
rainfall). Lows tonight will dip into the upper 50s and lower
60s.

If there is any fog development tonight, it will quickly burn
off Sunday morning, yielding a mostly sunny start to the day
just about everywhere. This will allow for daytime temps to
reach into the low/mid 80s once again.

There are some uncertainties regarding the fcst as we progress
into the afternoon and early evening on Sunday as the guidance
remains somewhat varied on the degree in which LL moisture is
mixed out during peak diurnal heating. This would have obvious
implications on SB instby during the late afternoon into the
evening, especially as the deeper-layer shear gradually
increases later in the day. As of right now, the trend seems to
suggest a mixing down of sfc DPs during the afternoon into
early evening, suggesting that convective coverage locally
during this time could be relatively minimal. Where the higher
LL moisture resides, likely just to the west of the ILN FA,
there will be some convection develop during the afternoon into
early evening, but think that most spots locally will remain dry
through this time period.

The more substantial forcing and deeper-layer shear will arrive
very late in the evening into the overnight period, with an
overall favorable synoptic-scale setup for large-scale ascent.
This will occur with some subtle theta-e advection N/NE into the
area late in the evening, suggesting that there may be some
destabilization efforts to the environment long after the
favorable diurnal cycle has ended. This being said, there are
considerable uncertainties in just how unstable the environment
is able to remain, with many fcst soundings showing a somewhat
unfavorable LL thermodynamic environment characterized by a
near-sfc inversion. This is especially the case with the
potential of a later arrival of the ascent, suggesting that we
may be able to stabilize sufficiently enough so that convection
that moves through during the overnight hours is primarily
elevated in nature. This is not to say it is going to be a quiet
night as there will likely be quite a bit of lightning/thunder
with convection that moves through during the overnight period.
This is discussed more thoroughly below.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Interesting start to the period with an H5 shortwave trough carving
through the Midwest. An associated surface low and attached cold
front will move through our fa overnight Sunday, leading to a more
organized line of showers/storms. Several models do hang onto enough
CAPE Sunday night to suggest at least a chance of thunder, with
effective shear values nearing 40 kts. The biggest limitation for
strong/severe thunderstorm potential will be unfavorable low level
lapse rates developing overnight as a near-surface inversion forms.
This may end up keeping majority of the convection elevated, but
there could still be some locations in our western CWA that will
need to be closely monitored for strong to isolated severe storm
potential. Models seem to suggest that the line of pcpn holds off
until closer to 06z (2 AM), with the line of showers/storms
progressing from west to east overnight.

A few showers may linger east of I-71 Monday morning before exiting
to our east. Surface high pressure begins to take control and keep
conditions dry through Tuesday. Temperatures will trend closer to
climatological normals Monday and Tuesday in the low to mid-70s.

Upper level flow becomes more zonal by Wednesday, but the pattern in
long-range models reveals several shortwaves rippling through
Wednesday through Thursday. This will help with initiating scattered
showers and some thunderstorms given the instability. Currently, the
best coverage in pcpn will be Wednesday night. This period will be
worth monitoring as instability appears to linger overnight and
favorable effective shear near 40 kts remains in place.

As we progress into Friday, long range models fairly consistent in
displaying an H5 ridge building across the eastern CONUS. A bubble
of high pressure forms underneath the ridge and favors dry
conditions. Additionally, an increase in temperatures and humidity
levels will be felt as we progress into the weekend under the
influence of the ridge.

 

 

[StormfanaticInd]

Feels like a summer afternoon with all these pop up thunderstorms