July 1-21, 2022 | Ring of Fire/MCS Outbreak Sequence

[ClicheVortex2014]

NAM is getting into range for the MCS setup. Pretty solid setup for Minnesota and the Great Lakes for the 4th of July. Looking at 5000+ cape, 35+ effective shear. Plenty of reason to suspect a MCS, if not initial supercells.

[ClicheVortex2014]

Dunno where this is but this is a textbook multicell thunderstorm

 

[Sentinel]

1 minute ago, ClicheVortex2014 said:

Dunno where this is but this is a textbook multicell thunderstorm

 

That is phenomenal

[snowlover2]

Quote

 Day 4-8 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0354 AM CDT Sat Jul 02 2022

   Valid 051200Z - 101200Z

   ...DISCUSSION...
   A prominent upper ridge is forecast to encompass much of the central
   CONUS into the Southeast through the extended forecast period. The
   potential for organized severe thunderstorms each day should be tied
   to low-amplitude shortwave troughs moving around the upper ridge
   from the northern Rockies/Plains into the Midwest and OH Valley
   vicinity. If any of these small-scale perturbations cresting the
   ridge can encourage a convective cluster to grow upscale into an
   MCS, then damaging winds would be possible as convection spreads
   east-southeastward across parts of the Midwest into the OH Valley
   and Great Lakes. The northern extent of any appreciable severe
   threat will be tied to the presence of rich low-level moisture
   along/south of a weak front. At this point, predictability remains
   low regarding the evolution/timing of these subtle mid-level
   perturbations, and related potential for one or more bowing clusters
   to develop and pose an organized severe risk.

   ..Gleason.. 07/02/2022

 

 

[ClicheVortex2014]

NAM really highlights the upcoming pattern. Outflow boundaries/MCVs from previous MCSs could add/enhance severe days.

[ClicheVortex2014]

1 minute ago, ClicheVortex2014 said:

NAM really highlights the upcoming pattern. Outflow boundaries/MCVs from previous MCSs could add/enhance severe days.

7-day QPF screams ring of fire/MCS events 

[ClicheVortex2014]

My standards for making a post on Facebook has increased greatly in the past decade, yet I felt the need to make a post about this coming week. I post this because I'm aware not everyone is able to keep up with of the vernacular we use here. My Facebook is filled with non-meteorological friends/family so I keep it right to the point. They can ask deeper questions if they want, like why a desert layer aloft increases instability, but that's not what most want.

Quote

The next week will feature a weather pattern conducive to some really strong storms. A strong, July-like high pressure will sit over the Southern Plains and create a Ring of Fire, as it's informally known. Storms fire along the rim of the high pressure, causing a precipitation pattern that resembles a ring. It gets that name because rain associated with convection is typically shown as different shades of red on radar.

This kind of pattern usually shows up at least once per year and is known to produce strong mesoscale convective systems (MCS) which often bring widespread damaging winds but come with extraordinary unpredictability with respect to when, where, and how strong. The takeaway is that this pattern is known to produce such convective systems. The regions typically impacted are the Upper Midwest into the Great Lakes and Ohio Valley. This weather regime should start on the 4th or 5th and last for maybe a week... hard to know at this point. But if you hear storms are possible, know that the storms could produce damaging winds on a rather large scale.

A decade ago now, in late June, a pattern kicked off that produced an extreme heat wave along with a sequence of very severe MCSs. The MCSs knocked off power in the middle of this heat wave that was producing widespread 100-110+ heat indices. This heat wave won't be as severe, and it's unlikely we'll see a repeat of MCSs of that intensity. However, it's possible one or two will because, again, this general pattern does produce those kinds of events.

The bare essentials of why these storms happen in this regime is 3 part:

1) Above average moisture (as a result of a stagnant pattern/modest moisture return from the Gulf) and above average temps (strong high pressure). This provides moderately to strongly unstable conditions on its own.

2) Desert air air from the Southwest gets advected into the Midwest and gets stuck aloft. Rapidly cooling temps aloft greatly increases instability... especially when it's placed above a thick layer of subtropical/tropical heat and moisture.

3) Due to lower pressures aloft in Canada/in the Northeast contrasting with the very strong high pressure in the Southern Plains, the jet stream actually strengthens enough to support organized storm systems, such as MCSs. It's dangerous to add seasonably strong winds aloft when there's a heat wave ongoing at the surface. Just as dangerous as the opposite case; unseasonably warm temps in the winter when winds aloft are never lacking. The two cases often provide very different results but they both often produce dangerous severe weather.

 

Edited July 3, 2022 by ClicheVortex2014

[ClicheVortex2014]

Quite the active pattern, verbatim

 

 

Edited July 3, 2022 by ClicheVortex2014

[StormfanaticInd]

Interesting week ahead. Hot and potentially very stormy

[StormfanaticInd]

Seems like it has been forever since we have had a major severe weather event other than the one a couple weeks ago in Ohio. This week looks interesting but these setups often bust around here anymore.

[snowlover2]

ILN still talking MCS's and microbursts through the week.

Quote

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
335 PM EDT Sun Jul 3 2022

.SYNOPSIS...
High pressure over the Great Lakes will move off to the mid
Atlantic on Monday. For the rest of the week, a number of
disturbances will drop across the Great Lakes bringing a
repeated chance for showers and thunderstorms.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Few diurnal cumulus will dissipate with loss of heating leaving
clear skies through the night. Temperatures will fall into the
60s.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
As high pressure center pass off to the east, low level flow
will become southerly. Dry atmosphere will remain in place with
just a bit cumulus and some thin cirrus. Highs will be a few
degrees warmer than today. Quiescent conditions will continue
into Monday evening. Heading into the overnight, will be
watching for the potential for an MCS to drop out of the lower
Great Lakes and possibly reach northern counties before daybreak
Tuesday. Low will only fall into the lower 70s.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Ridging will be centered west of the Ohio Valley for the middle to
end of the week leading to middle/upper level northwesterly flow
over the region. This upper level flow pattern is expected to
overlap with hot, humid, unstable air in the area and a meandering
frontal boundary. The synoptic setup described will likely be
favorable for multiple rounds of showers and storms through the end
of the week. The exact timing and placement of storms cannot be
determined at this time due to the convective nature of the events.
However, the chance for showers and storms will generally peak in
the afternoon/evening when peak instability occurs. Any storms could
produce locally heavy rain in the high PWAT environment. Storms
could also pose a damaging wind threat due to microburst potential
(high DCAPE) although MCS organization is also possible in the
northwest flow regime south of the front. Forecast temperatures
remain 5-10 degrees above average through at least the second half
of the work week.

 

 

[ClicheVortex2014]

Day 3 slight risk for the OV. I suspect the first of many over the next week or two.

  Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0230 AM CDT Sun Jul 03 2022

   Valid 051200Z - 061200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   THE OHIO VALLEY INTO THE MID-ATLANTIC...AND THE NORTHERN/CENTRAL
   PLAINS...

   ...SUMMARY...
   Isolated to scattered severe thunderstorms may occur Tuesday across
   parts of the Ohio Valley into the Mid-Atlantic, and portions of the
   northern/central Plains.

   ...Ohio Valley into the Mid-Atlantic...
   Downstream of a prominent upper ridge over the Plains, a
   convectively enhanced, low-amplitude shortwave trough should advance
   eastward from the Great Lakes across parts of the OH Valley and
   Mid-Atlantic on Tuesday. Modestly enhanced mid-level winds will
   accompany this shortwave trough, and sufficient deep-layer shear for
   organized updrafts should overspread these regions through the day.
   Current expectations are that diurnal heating of a moist low-level
   airmass will act to destabilize the environment ahead of one or more
   clusters of thunderstorms that should be ongoing Tuesday morning
   across some portion of the Midwest/Great Lakes. Convection should
   increase in coverage and intensity Tuesday afternoon as it spreads
   eastward across parts of the OH Valley into the Mid-Atlantic.
   Damaging winds will be a concern with any clusters that can develop,
   but isolated large hail may also occur with any discrete
   thunderstorms. The eastern extent of the severe risk remains
   somewhat uncertain, as low-level moisture may be somewhat more
   limited towards the Atlantic Coast.

 

Day 4-8 outlook. Sounds like they were close to issuing a day 4 slight.

   ...DISCUSSION...
   Medium-range guidance is in good agreement that a prominent upper
   ridge will remain over much of the central CONUS through at least
   late this week. Appreciable severe potential should be tied to
   low-amplitude shortwave troughs that will advance around the
   periphery of the upper ridge from the northern Rockies/Plains into
   the Midwest, OH Valley, and occasionally the Mid-Atlantic. One such
   perturbation, which appears in guidance to be convectively
   augmented, may move from the Dakotas across parts of the Upper
   Midwest on Day 4/Wednesday. A moist and rather unstable airmass
   should be present along/south of a front across these regions
   Wednesday afternoon. Depending on the presence of morning convection
   and the evolution of the subtle shortwave trough, an MCS capable of
   producing severe/damaging winds may evolve from parts of the
   northern Plains into the Midwest through Wednesday evening. There is
   not enough confidence in the placement and track of this potential
   MCS to include a 15% severe area at this time, but this will be
   reevaluated in later outlooks.

   Thereafter, the overall predictability in organized severe
   thunderstorms appears low. Some severe potential will probably exist
   each day through at least Day 6/Friday across portions the northern
   Rockies and adjacent High Plains, as convection forms over the
   higher terrain and spreads eastward into a more unstable airmass. As
   multiple weak mid-level perturbations round the crest of the upper
   ridge, additional MCS/bowing clusters capable of producing damaging
   winds may also occur from the Upper Midwest into the OH
   Valley/Mid-Atlantic vicinity through the end of the week. But,
   confidence remains low in the placement and evolution of these
   features at this extended time frame. By next weekend, a stronger
   mid-level shortwave trough may impinge on the upper ridge as it
   moves across the northern Rockies/Plains into central Canada. Trends
   will be monitored for an increased severe potential across this
   region around Day 7/Saturday into Day 8/Sunday.

 

Edited July 3, 2022 by ClicheVortex2014

[ClicheVortex2014]

Fantasy range NAM has a significant tornado outbreak for... Pennsylvania.

Disclaimer: I wouldn't rule out a tornado outbreak in this regime. This just seems to be classic NAM overreacting.

[ClicheVortex2014]

Embedded supercell in a squall in Montana has some rotation

 

Edited July 3, 2022 by ClicheVortex2014

[ClicheVortex2014]

Crazy how quick a preexisting mesocyclone can warp a seemingly ordinary cell into a supercell

[ClicheVortex2014]

CIPS analogs for Tuesday isn't convincing of a high-end event, though there are signs of a possibly widespread event for Ohio. To be fair to NAM, there's also an analog that has a tornado outbreak for the Mid-Atlantic.

[ClicheVortex2014]

1 hour ago, ClicheVortex2014 said:

Fantasy range NAM has a significant tornado outbreak for... Pennsylvania.

Disclaimer: I wouldn't rule out a tornado outbreak in this regime. This just seems to be classic NAM overreacting.

To add to why I think this is NAM being NAM:

It looks to me like Tuesday will be split into two severe weather regimes. Most of Ohio is instability heavy, weaker on shear. Pennsylvania/Mid-Atlantic has stronger shear but moisture/instability is in question.

It's not surprising to me that NAM is overestimating moisture/instability, especially in the region where there's some dispute among models. NAM is known for that, and that's likely the case here.

Not only that, but NAM has a 998mb low in northern New England. GFS has 1004mb, Euro 1008mb. A stronger low means greater moisture return, stronger low-level shear, and speed shear in general. Mesoscale models really aren't the ones to go to when trying to figure out the strength of a synoptic low pressure.

WPC has a 1006mb "low" where NAM has 998mb. 

So the Pennsylvania/Mid-Atlantic threat is being way overblown IMO. The focus should be on eastern Indiana/Ohio/western PA.

Edited July 4, 2022 by ClicheVortex2014

[ClicheVortex2014]

The squall in Montana has devolved and all that remains is a supercell that has taken a hard right turn

[Chinook]

There have been a few severe storm reports in Montana today, not really enough to verify the enhanced risk. I saw some great wall cloud pictures on twitter, along with a video of a flood in downtown Helena. Here is a reasonably good radar view of a supercell that was 86 miles from the KGGW radar. The supercell composite parameter maxed out at about 12 at some parts of Montana.

 

 

small scale squall line with possibly two areas of strong wind, although the base velocity is not that impressive

 

 

Edited July 4, 2022 by Chinook

[snowlover2]

0z HRRR which goes through Tuesday.

[ClicheVortex2014]

22 minutes ago, Chinook said:

There have been a few severe storm reports in Montana today, not really enough to verify the enhanced risk. I saw some great wall cloud pictures on twitter, along with a video of a flood in downtown Helena. Here is a reasonably good radar view of a supercell that was 86 miles from the KGGW radar. The supercell composite parameter maxed out at about 12 at some parts of Montana.

 

 

small scale squall line with possibly two areas of strong wind, although the base velocity is not that impressive

 

 

The enhanced risk would easily verify on storm reports if Montana was more populated. But the intensity of the storms on radar suggests this was easily worthy of an enhanced risk.

Edited July 4, 2022 by ClicheVortex2014

[ClicheVortex2014]

NAM continues to triple and quadruple down on this ridiculous scenario. To be fair, NE OH/W PA has had a few major/historic tornado outbreaks that includes at least 3 EF4+ each so it's not unprecedented, but I still don't think this is gonna be the next case.

 

Nonetheless... here's a NAM sounding for NW PA.

Edited July 4, 2022 by ClicheVortex2014

[snowlover2]

49 minutes ago, ClicheVortex2014 said:

NAM continues to triple and quadruple down on this ridiculous scenario. To be fair, NE OH/W PA has had a few major/historic tornado outbreaks that includes at least 3 EF4+ each so it's not unprecedented, but I still don't think this is gonna be the next case.

 

Nonetheless... here's a NAM sounding for NW PA.

3K NAM just a little different.

[ClicheVortex2014]

10 minutes ago, snowlover2 said:

3K NAM just a little different.

Not a big fan of 3km NAM because this is one reason... *crickets*

 

[ClicheVortex2014]

Mini-supercell in Nebraska with a debris signature