July 13-?, 2024 | Potential MCS Pattern

[NWOhioChaser]

*sigh*

Might get missed again. Have a feeling this will dive quicker than we think. 

[snowlover2]

ILN has one hell of a write up.

Quote

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
248 PM EDT Mon Jul 15 2024

.SYNOPSIS...
An unsettled weather pattern will be in place through the middle
of the week. Multiple disturbances will move through and then a
cold front will move through Wednesday. Warm temperatures will
also be in place until the passage of the cold front. Drier and
cooler conditions are expected for the second half of the
week into the upcoming weekend.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
A remnant/decaying MCV continues to pull away from the area,
with an axis of clouds extending to the SW of the MCV center
near the I-70 corridor near a weakly-convergent axis, which is
supporting some pooling of better LL moisture. Although quite a
bit of clearing has evolved behind this MCV thus far this
afternoon within a subsidence regime, agitated Cu and ISO SHRA are
beginning to expand in coverage in EC/SE IN and WC OH. Amidst a
subtly convergent W-E oriented axis very close to the I-70
corridor, expect an expansion of the Cu field, and the
corresponding ISO/SCT TSRA to go along with it as we progress
into mid/late afternoon. With only subtle forcing/lift but a
favorable LL thermodynamic environment characterized by steep LL
lapse rates, any convection that develops will likely gust out
fairly quickly, initiating new convection along any outflows.
The activity may organize into small clusters which would pose a
better potential for ISO gusty to damaging winds, so the
organizations trends will be monitored closely through the
afternoon. Don`t think that organization or coverage will be
high enough to warrant a watch issuance, but certainly a few
instances of gusty to isolated damaging winds can be expected,
especially near/S of the I-70 corridor where coverage of
activity is expected to be the greatest. Will continue mention
in the HWO.

Ample subsidence in the immediate wake of the AM MCV led to
abundant sunshine through the noontime hour, allowing for temps
and dewpoints to rise steadily. The combination of temps in the
lower 90s and dewpoints in the lower 70s has allowed for heat
index values around 100 to evolve this afternoon for many spots
near the OH Rvr and just S of I-70. ALthough there are still
some uncertainties regarding afternoon convective redevelopment
and the associated impact on temps/heat index values, feel that
there still should be slightly cooler temps/dewpoints N of I-70
in central OH that heat index values should largely stay below
advisory thresholds.

As we progress late into the evening by/past sunset, our focus
will quickly shift from the waning convection locally to an
intense MCS that will likely be in the early stages of
development in ern IA/nrn IL. There is now a fairly consistent
signal for a robust MCS to develop in far nrn IL before quickly
racing to the E through nrn IN late this evening. As it
approaches the ILN FA around/after midnight, two things are
expected to occur:

1) The momentum of this strong MCS, characterized by a /very/
impressive RIJ (as depicted within the H8 wind fields of
50-60kts), will likely carry the outflow/gust front well into
the local area, especially parts of WC into central OH around
06z-09z. Although the MCS will be outrunning its forcing a bit
with eastward extent, it will become somewhat self-sustaining,
meaning that convection (SHRA/TSRA) will likely be maintained
longer than is shown by some guidance. As such, do think we will
be in a situation where we will have near-severe or severe wind
gust potential in EC IN and WC OH between about 05z-07z before
the complex weakens and "fans out," ejecting the (mostly
subsevere) gust front to the E into central OH, southeast into
the Miami Valley, and to the S into the Tri-State and SE IN. Do
think that the best potential for severe storms (wind gusts)
associated with this feature will be from Wayne/Fayette/Union
Cos in IN to the ENE through Union Co OH and points to the N/NW
of this line between 05z-07z.

2) There is likely to be fairly robust convective
redevelopment/backbuilding on the SW fringe of the complex as
the unseasonably strong (non-storm augmented SW LLJ of 30+kts)
runs into the WNW-ESE fresh convectively-induced boundary laid
out by the primary MCS/MCV further to the N across far nrn OH.
This will promote aggressive moisture/mass convergence along a
slowly-sagging southward-moving boundary, primarily stretching
across central/southern parts of IL/IN. There are some
indications that this heavy rain potential /may/ creep into
EC/SE IN very late tonight, with slow-moving TSRA producing
torrential rainfall rates. There is not yet enough confidence to
issue a Flash Flood Watch for parts of EC IN into SE IN and far
wrn parts of the Tri-State as the complex should move more to
the S, or even SSW, with time. But there are still some
uncertainties regarding the location/placement of the MCS and
the corresponding regenerative activity expected between
06z-12z. But the best signal is for the more concerning flash
flood setup to be just off to our W.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
In the wake of the southward-sagging MCS/convection Tuesday
morning, a good deal of subsidence/cloud debris will evolve
locally through much of the daytime, suggesting lower PoPs
through at least mid afternoon for much of the area. However,
there should be some SHRA/TSRA redevelopment N of I-70 into late
afternoon, with some ISO activity possible elsewhere into the
evening hours. There is likely to be a slow uptick in convective
coverage (with better forcing/lift moving into the area) into
the evening/overnight hours, with the best coverage slowly
shifting S of I-70 to closer to/S of the OH Rvr after midnight.

It is within this regime/setup that the greatest flash flood
risk for us locally may evolve as W-E steering-layer flow
overlaps with an increasingly-west to the east oriented LL
baroclinic zone (front). Ripples of S/W energy migrating from W
to E within the enhanced zonal midlevel flow will provide enough
forcing and lift for continued convective redevelopment late in
the evening into the overnight, with PWATs near/in excess of 2".
There is at least some concern for training convection to move
near/along an axis stretching from SE IN into srn fringes of
central OH (and points S into N/NE KY) that very well could
promote some flooding potential Tuesday night. At this juncture,
there is not enough confidence regarding exact location to
issue a Flash Flood Watch, but it is mentioned here for
awareness purposes and will continue to be highlighted in the
HWO.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
The cold front will finally shift southeast through most of the area
on Wednesday. The latest guidance shows a surface wave associated
with a mid-level disturbance rippling along the front somewhere
close to the Ohio River. Based on a very moist vertical profile as
well as elevated instability, would think the primary threat will
likely be heavy rain and localized flooding before the shortwave
drags the front out of our CWA late in the day.

High pressure will build into the region behind the front, providing
cooler weather late this week through the weekend. The high will
likely begin to break down starting Monday allowing some return
moisture and a chance of precipitation returning to southern
areas.

 

[NWOhioChaser]

Some mean looking storms here. 

[btbucks]

Got some dime size hail here.

[Chinook]

Is anybody else getting 14 minute delay on GRLevel3/GRLevel2? This is not like the usual operation of having data that's about 2 minutes old.

[StormfanaticInd]

Noticing some rotation in Greensburg Indiana 

Edited July 15 by StormfanaticInd

[snowlover2]

Dubuque getting hammered with possible 90mph winds!

Quote

Severe Weather Statement
National Weather Service Quad Cities IA/IL
612 PM CDT Mon Jul 15 2024

ILC085-IAC055-061-097-105-152345-
/O.CON.KDVN.SV.W.0306.000000T0000Z-240715T2345Z/
Jo Daviess IL-Jackson IA-Dubuque IA-Jones IA-Delaware IA-
612 PM CDT Mon Jul 15 2024

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM CDT
FOR WESTERN JO DAVIESS...NORTHERN JACKSON...DUBUQUE...NORTHEASTERN
JONES AND DELAWARE COUNTIES...

At 611 PM CDT, a severe thunderstorm was located over Dubuque, moving
east at 45 mph.

THIS IS A DESTRUCTIVE STORM FOR Dubuque, Galena, and Bellevue

HAZARD...90 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...You are in a life-threatening situation. Flying debris may
         be deadly to those caught without shelter. Mobile homes
         will be heavily damaged or destroyed. Homes and businesses
         will have substantial roof and window damage. Expect
         extensive tree damage and power outages.

Locations impacted include...
Dubuque, Manchester, Galena, Asbury, Dyersville, Bellevue, Cascade,
Epworth, East Dubuque, Farley, Peosta, Edgewood, Earlville,
Hopkinton, Delhi, New Vienna, Colesburg, Worthington, Scales Mound,
and Holy Cross.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4263 9071 4251 9064 4251 9022 4215 9032
      4238 9143 4264 9161
TIME...MOT...LOC 2311Z 274DEG 37KT 4249 9070

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...DESTRUCTIVE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...OBSERVED
MAX WIND GUST...90 MPH

 

[StormfanaticInd]

[StormfanaticInd]

[Hoosier]

LOT mesoscale update

.MESOSCALE...
Issued at 546 PM CDT Mon Jul 15 2024

Explosive severe thunderstorm development has taken place across
Iowa, with storm tops exceeding 65kft. Special soundings from
DVN and ILX both show extreme instability and moderate deep
layer shear, though sufficient shear to support storm scale
organization in light of the extreme instability.

Already seeing signs of amalgamating cold pools/downdrafts with
convection over Iowa with radar showing some developing rear
inflow jets. The evolution of the convection so far continues to
fit the expectations for today with evolution to QLCS well
underway. As cold pool strengthens, would anticipate a QLCS to
begin accelerating eastward with increasing damaging wind threat
as storms approach and cross the Mississippi River.

Strengthening low level jet this evening over northern Illinois
should result in a ramping up of low level shear and coincident
increasing threat of QLCS tornadoes with bowing segments and/or
line embedded supercells. Given the shear/instability combo,
threat is certainly there for a large number of QLCS tornadoes
this evening over northern IL.

Recent satellite/radar imagery shows some cells developing over
far northern Winnebago County near the Wisconsin line. This
could be the beginnings of a "warm air advection" wind ahead of
the Iowa QLCS, which if it is and continues to fill in this
could result in a potential significant/high end flash flood
threat in our CWA if storms drift south of the IL/WI border.
Given the vulnerability of the Rockford area due to nearly 10"
of rain over the past 48 hours, this will be something that we
will be monitoring extremely closely.

- Izzi

 

[snowlover2]

Tornado warnings all along that line.

[StormfanaticInd]

This is a very impressive mcs/qlcs. Going to be several tornadoes and destructive winds 

[NWOhioChaser]

Ugh, to stay up for this line or go to bed.. that’s the question. I feel like it’s going to split us again.

[StormfanaticInd]

Wow

[junior]

Peak strength Wow. Models had this diving more south into IL but its still riding ESE. Perhaps the MCV at the IL/WI will continue into MI but the rest of the system will gust out.

Edited July 16 by junior

[TheRex]

Stay safe everyone!

I was pulling up the lightning tracker map for the small storms we are having in VT and noticed there was constant lightning in the Midwest region. It looks like it could be a very dangerous state situation out there. 

[StormfanaticInd]

Power outages are climbing fast

[StormfanaticInd]

Chicago and Gary with storm warnings and tornado warnings

[snowlover2]

Quote

 Mesoscale Discussion 1643
   NWS Storm Prediction Center Norman OK
   0937 PM CDT Mon Jul 15 2024

   Areas affected...Central Illinois into central Indiana

   Concerning...Severe potential...Watch likely 

   Valid 160237Z - 160400Z

   Probability of Watch Issuance...95 percent

   SUMMARY...A downstream watch across central Illinois into central
   Indiana is expected within the next hour as a severe MCS continues
   to push east/southeast.

   DISCUSSION...The southern end of a severe MCS continues to propagate
   to the southeast along and south of a diffuse baroclinic zone draped
   into eastern IL/central IN. Severe winds continue to be reported
   with this line over the past 30 minutes, and GOES IR imagery
   continues to show strong updraft pulses along the leading edge of
   the cold pool. High boundary-layer moisture content downstream into
   central IL/central IN (dewpoints in the upper 70s) will modulate the
   effects of nocturnal cooling/stabilization resulting in ample
   buoyancy (3000-4000 J/kg MLCAPE) with limited inhibition for MCS
   maintenance. Consequently, the expectation is for the MCS to
   continue well into central IL/central IN with an attendant threat
   for severe winds, including the potential for signification severe
   winds (75+ mph).

   ..Moore/Thompson.. 07/16/2024

 

[snowlover2]

Don't see this everyday.

Quote

Severe Weather Statement
National Weather Service Chicago/Romeoville
954 PM CDT Mon Jul 15 2024

INC089-160315-
/O.CON.KLOT.TO.W.0030.000000T0000Z-240716T0315Z/
Lake IN-
954 PM CDT Mon Jul 15 2024

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1015 PM CDT FOR LAKE
COUNTY...

At 954 PM CDT, tornado producing storms were located along a line
extending from South Deering to Dyer to near Grant Park, moving east
at 60 mph.

HAZARD...Damaging tornadoes. This storm is producing mulitple
         tornadoes at the same time!

SOURCE...Radar confirmed tornado.

IMPACT...Flying debris will be dangerous to those caught without
         shelter. Mobile homes will be damaged or destroyed. Damage
         to roofs, windows, and vehicles will occur.  Tree damage is
         likely.

Locations impacted include...
  Hammond, Gary, Merrillville, East Chicago, Schererville, Hobart,
  Crown Point, Highland, Cedar Lake, Lowell, Portage, Lakes of the
  Four Seasons and New Chicago.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. TAKE COVER NOW! Move to a
basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.

&&

LAT...LON 4130 8753 4171 8752 4170 8751 4167 8747
      4167 8744 4168 8743 4167 8742 4165 8744
      4164 8743 4162 8729 4162 8722 4130 8722
TIME...MOT...LOC 0254Z 263DEG 53KT 4168 8754 4148 8752 4126 8754

TORNADO...OBSERVED
MAX HAIL SIZE...0.00 IN

 

[snowlover2]

Quote

 URGENT - IMMEDIATE BROADCAST REQUESTED
   Severe Thunderstorm Watch Number 542
   NWS Storm Prediction Center Norman OK
   1055 PM EDT Mon Jul 15 2024

   The NWS Storm Prediction Center has issued a

   * Severe Thunderstorm Watch for portions of 
     East central Illinois
     West central into central Indiana

   * Effective this Monday night and Tuesday morning from 1055 PM
     until 500 AM EDT.

   * Primary threats include...
     Scattered damaging winds and isolated significant gusts to 75
       mph likely
     Isolated large hail events to 1 inch in diameter possible
     A tornado or two possible

   SUMMARY...A well-formed, bowing squall line with a history of
   damaging winds will continue east-southeastward from Illinois into
   Indiana through the early morning hours.  Wind damage and severe
   wind gusts of 60-75 mph will be the main threat, though isolated
   large hail near 1 inch in diameter and a tornado or two with
   embedded circulations will also be possible.

   The severe thunderstorm watch area is approximately along and 45
   statute miles north and south of a line from 40 miles south
   southwest of Decatur IL to 40 miles northeast of Indianapolis IN.
   For a complete depiction of the watch see the associated watch
   outline update (WOUS64 KWNS WOU2).

   PRECAUTIONARY/PREPAREDNESS ACTIONS...

   REMEMBER...A Severe Thunderstorm Watch means conditions are
   favorable for severe thunderstorms in and close to the watch area.
   Persons in these areas should be on the lookout for threatening
   weather conditions and listen for later statements and possible
   warnings. Severe thunderstorms can and occasionally do produce
   tornadoes.

   &&

   OTHER WATCH INFORMATION...CONTINUE...WW 539...WW 541...

   AVIATION...A few severe thunderstorms with hail surface and aloft to
   1 inch. Extreme turbulence and surface wind gusts to 65 knots. A few
   cumulonimbi with maximum tops to 550. Mean storm motion vector
   30040.

   ...Thompson

 

[Chinook]

Definitely the significant wind threat/45% was necessary

 

 

triple tornado warnings near Chicago earlier

 

 

the storm had 6500 J/kg to work with earlier

Edited July 16 by Chinook

[Hoosier]

Nice storm here.  Got pretty windy and the power flickered several times, but no signs of damage right here from what I can tell.  I saw several green flashes in the sky that looked like transformers blowing.  

Looks like there were multiple tornadoes in Chicago metro, and might've had something tornadic in the city again for the 2nd night in a row.  

[cer5059]

 

Hey AA1776, this is ATC, we just received a tornado warning alert so we're going to have to evacuate the tower and ground control is heading in for cover too. Good luck out there and we'll get back to you once the tornado passes. 

Talk about negligence 

 

[TheRex]

4 hours ago, cer5059 said:

 

Hey AA1776, this is ATC, we just received a tornado warning alert so we're going to have to evacuate the tower and ground control is heading in for cover too. Good luck out there and we'll get back to you once the tornado passes. 

Talk about negligence 

 

It seems someone didnt do a good job looking downstream to see what was coming there way.  This could have been a huge mass casualty event.  I hope the powers that be make some changes for the future.