JUNE 25-27 SEVERE WEATHER POTENTIAL

[StormfanaticInd]

Pretty decent setup showing for this period. Could be a couple of long lived severe mcs(derecho?). There will plenty of instability/shear to work with which usually means trouble in the summer

[StormfanaticInd]

 

[StormfanaticInd]

👀

[Chinook]

Some storms should get going into an MCS in Minnesota tomorrow night, probably into Wisconsin. The CAMs are not in much agreement as to when and where initial storms will get going. Hey, want to see an insane forecast sounding for CAPE? Here it is, with over 8000 J/kg of CAPE. It's at the southwest corner of Minnesota.

[StormfanaticInd]

Hi res models are not that excited about tomorrow. Hmmmm....

[StormfanaticInd]

Day 1 Convective Outlook  

NWS Storm Prediction Center Norman OK

0800 AM CDT Mon Jun 24 2024

 

Valid 241300Z - 251200Z

 

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE UPPER

MIDWEST...

 

...SUMMARY...

Scattered severe thunderstorms are expected over parts of the Upper

Midwest this afternoon into tonight. Storms will be capable of large

hail, and a cluster potentially capable of destructive wind gusts

could develop over parts of Minnesota into Wisconsin.

 

...Upper Midwest...

A mid-level trough will continue to transition eastward and modestly

amplify over the Canadian Prairies, with southern-peripheral height

falls and strengthening westerlies from North Dakota/northern

Minnesota toward the Upper Great Lakes through tonight. In this same

corridor, a weak MCV may be evolving this morning over eastern North

Dakota/northwest Minnesota, while these scattered thunderstorms will

probably also influence and somewhat hinder the effective

north-northeastward of a warm front later today across Minnesota and

Wisconsin.

 

A very moist (low 70s F dewpoints) and unstable air mass will

otherwise develop northeastward regionally in tandem with the warm

front as surface cyclogenesis occurs across the Siouxland and

southern Minnesota through evening. Upwards of 3000-5000 J/kg MLCAPE

is expected within the warm sector, with very warm mid-level

temperatures associated with the elevated mixed-layer plume likely

limiting warm sector development away from (south of) the immediate

triple point and cold front/warm front vicinity. 

 

Multiple convective scenarios are possible late this afternoon

through tonight. For one, as the air mass recovers from the early

day storms, widely scattered surface-based thunderstorms may develop

by late afternoon near the eastward-advancing cold front within the

relatively narrow warm sector from far eastern North Dakota into

northern/western Minnesota. Any storms that do develop will likely

organize into supercells given strong wind profiles and the large

buoyancy. Large to very large hail, damaging winds and perhaps a

tornado would be possible with any supercells, especially with

storms in proximity to the warm front.

 

Additionally, on the southern fringe of the early scattered early

day convection (and related cloud cover) from eastern North Dakota

into northern Minnesota, storms may form near an effective triple

point/differential heating reinforced warm front. Such initial

development could occur across south-central/southeast Minnesota,

with robust instability/seasonally strong shear potentially

supportive of an initial mode of intense supercells, with subsequent

upscale growth in an MCS with heightened damaging wind potential. 

 

Additional mostly elevated storms could form tonight from eastern

Minnesota into northern/central Wisconsin, on the immediate cool

side of the surface baroclinic gradient as a nocturnally

increasingly low-level jet heightens isentropic ascent. These storms

may also pose a large hail and damaging wind risk through the

overnight.

 

An upgrade to Enhanced Risk (Level 3/5) may be warranted pending

morning observational/guidance trends, potentially including a

corridor across south-central/southern Minnesota and west/southwest

Wisconsin, where a semi-focused swath of potentially significant

damaging winds appears plausible.

[StormfanaticInd]

 

Day 2 Convective Outlook  

NWS Storm Prediction Center Norman OK

1258 AM CDT Wed Jun 05 2024

 

Valid 061200Z - 071200Z

 

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE

EAST-CENTRAL INTO SOUTHEAST FL PENINSULA....

 

...SUMMARY...

Thunderstorms are anticipated along an expansive cold front from the

Northeast into the Southeast and Lower Mississippi Valley as well

over portions of the southern High PLains and the Florida Peninsula.

Isolated severe thunderstorms are most likely across the

east-central and southeast Florida Peninsula.

 

...Synopsis...

A mature mid-latitude cyclone will likely be over far northwestern

Ontario early Thursday before then progressing southeastward into

the Upper Great Lakes throughout the day. During this same period,

upper ridging is forecast to build from the Southwest and southern

Plains into the Pacific Northwest. A belt of enhanced

westerly/northwesterly flow will exist between these two features,

extending from the northern Plains through the Mid MS and OH Valley.

 

At the surface, a cold front is expected to extend southward from a

low over eastern Ontario across western NY and eastern PA before

then arcing more southwestward along the central and southern

Appalachians and then more westward across the Southeast and into

central TX. 

 

...Northeast/Mid-Atlantic...

Northern/eastern portion of this front is expected to remain

progressive, moving off the Northeast and northern Mid-Atlantic

coast by early Friday morning. Mid-level temperatures across the

region preceding the front will be warm, with associated poor

mid-level lapse rates. Even so, dewpoints in the upper 60s will help

support modest buoyancy and the potential for thunderstorms along

and ahead of the front. Much of the stronger mid-level flow will be

displaced west of the front, keeping vertical shear modest and

limiting storm organization.

 

...Southeast into the Southern Plains...

Southern/western portion of front is expected to be less

progressive, only making modest southerward push across TX and the

Southeast while becoming increasingly diffuse. Isolated

thunderstorms are possible ahead of this front, particularly from GA

into NC. A secondary push of continental air will likely become a

more defined frontal zone from OK into the Mid-South/TN Valley, with

some chance for afternoon/evening thunderstorm development ahead of

this front from the TX Panhandle into central OK. A few stronger

storms are possible, but weak shear is currently expected to limit

severe potential.

[StormfanaticInd]

Extreme instability building. Might need a moderate risk???

[StormfanaticInd]

2 hours ago, StormfanaticInd said:

Extreme instability building. Might need a moderate risk???

Now approaching 8000 surface cape 🧐

Edited June 24 by StormfanaticInd

[StormfanaticInd]

Going to be very interesting to see how tonight and tomorrow play out. Big time wind potential pending how things develop 

[Chinook]

anybody want to see some crazy numbers? I wonder what the MPX sounding will look like tonight

 

 

Edited June 25 by Chinook

[StormfanaticInd]

14 minutes ago, Chinook said:

anybody want to see some crazy numbers? I wonder what the MPX sounding will look like tonight

 

That's beyond crazy lol

 

[StormfanaticInd]

Storms in southern Wisconsin look interesting.

[snowlover2]

0z HRRR

[StormfanaticInd]

7 minutes ago, snowlover2 said:

0z HRRR

Really have to take these hi res models with a grain of salt. Hrrr is not even handling the current storms in southern Wisconsin correctly 

[junior]

Looks like an MCS type of week.

Edited June 25 by junior

[snowlover2]

Quote

Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0101 AM CDT Tue Jun 25 2024

   Valid 251200Z - 261200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
   THE CENTRAL PLAINS...MIDWEST AND MID MISSISSIPPI VALLEY...

   ...SUMMARY...
   Scattered severe thunderstorms are possible across parts of the
   central/southern Great Plains and Midwest late this afternoon and
   evening. Damaging wind gusts, large hail, and a tornado or two may
   are possible.

   ...Central Plains and Midwest...
   A complex and highly uncertain forecast scenario is likely to evolve
   today, as the remnants of one or more convective clusters interacts
   with a broadly moist and unstable air mass over the Midwest and
   central Plains. Early in the period, an MCS may be ongoing across
   parts of the southern Great Lakes and OH Valley. Near the eastern
   extent of the buoyancy plume reintensification of the eastern most
   convection/remnants thereof appears unlikely through the morning
   across the mid to upper OH Valley.

   Farther west across IL and IN, any ongoing storms or remnant
   outflow, should continue south and may reintensify/reinvigorate over
   the mid MS Valley by mid morning. While mid-level flow decreases
   with southern extent, moderate buoyancy may sustain a risk for
   damaging gusts with a loosely organized cluster/MCS, potentially as
   far south as the lower OH/Mid MS Valley this evening.

   A greater focus for severe convection appears likely to evolve along
   the slow-moving synoptic cold front drifting south across the
   central Plains. Strong heating along the front ahead of a subtle
   shortwave trough will allow for isolated storm development this
   afternoon. Model soundings show enhanced mid and upper-level shear
   profiles, along with steep mid-level lapse rates. Supercells may
   evolve with an initial risk for large hail, given MLCAPE of
   4000-5000 J/kg and the discrete mode. A brief tornado or two may
   also be possible with enhanced vertical voritcity and low-level
   shear near the front.

   With time, mostly front-parallel flow will favor upscale growth into
   clusters and potentially an MCS over eastern NE and IA. With
   plentiful MLCAPE (2000-3000 J/Kg) in place over the region, damaging
   winds will remain possible as storms track east/southeast into the
   eastern central Plains and the mid MS Valley. The exact
   eastern/southern extent of any severe risk remains quite uncertain,
   given the tendency for storms to outrun the stronger upper-level
   support. Still, a few CAM members suggest a coherent line of storms
   will continue overnight reaching southern MO/IL and eastern KS
   before the start of the Day2 period.

   ...KS OK and the TX Panhandle...
   On the northern fringes of the subtropical ridge over the southern
   third of the CONUS, robust diurnal heating should support very hot
   daytime temperatures along and east of dryline from west-central KS,
   into northwest OK and the TX Panhandle. As the western portion of
   the ridge intensifies, flow aloft should gradually veer to
   northwesterly as a weak mid-level perturbation traverses the
   periphery of the ridge and moves out of the central Rockies. Weak
   ascent should overlap with near-convective surface temps in the low
   100s F during the later afternoon, supporting isolated to widely
   scattered thunderstorm development along and east of the dryline.
   Moderate buoyancy within the well-mixed but moist surface air mass,
   along with enhanced mid and upper-level flow, will favor a mixed
   mode of high-based multicell clusters and perhaps transient
   supercells capable of damaging gusts and isolated hail. The
   longevity of these storms is somewhat questionable, given the
   tendency for weakening upper-level support and warming mid-level
   temperature to the south, but at least an isolated severe risk may
   persist into parts of central OK/KS into the early evening.

   ...Dakotas and western MN...
   Behind the main synoptic front, daytime heating over residual
   boundary-layer moisture should support the development of moderate
   buoyancy ahead of a second weaker cold front moving out of southern
   Canada. A shortwave trough over the northern Rockies is forecast to
   intensify as it moves southeast into the Plains. Modest forcing for
   ascent coupled with weak low-level warm advection may support
   isolated storm development late in the afternoon, eventually moving
   into the eastern Dakotas and western MN by early evening. Relatively
   long and straight hodographs suggest the potential for a few
   elevated supercells with a risk for isolated large hail.

   ..Lyons/Barnes.. 06/25/2024

 

[snowlover2]

ILN

Quote

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Tranquil conditions will continue locally through daybreak,
although they won`t last too much long, unfortunately. As the
sfc high shifts to the E of the OH Vly through the morning,
abrupt moisture return will begin to nose back into the area
from the W into the afternoon hours. This will occur following
the S/W ejecting E through the Great Lakes region through
daybreak, which has prompted the development of a stout and
increasingly-well organized MCS now across WI, which will track
to the ESE into MI and far nrn IL/IN/OH through mid morning. As
this occurs, we may see a few WAA-induced WAA develop along a
N-S oriented axis across EC IN and WC OH, primarily between
about 13z-17z, but this should be of little consequence to the
convective evolution through the rest of the day.

The forecast later into the daytime becomes incredibly complex,
and will be largely dictated by convective evolution throughout
the time period. As the primary S/W pulls to the NE of the OH
Vly late morning into early evening, taking with it the better
forcing, the remnant outflow/boundary stretching back to the W
should serve as a focus for renewed convective development by
early afternoon across nrn IL/IN/OH. This will occur as activity
attempts to redevelop closer to the pool of better
moisture/instby collecting/advecting across IL/IN and far wrn
OH. Confidence continues to increase in the potential for
redevelopment, to a certain extent, of a E-W oriented axis of
TSRA along the stale MCS boundary. This reason for this is
partially because of the delayed timing (compared to previous
fcsts), which will allow /just enough/ time for a surge of
higher theta-e air (better LL moisture content) to nose into
areas near/W of I-75 into early afternoon. The latest guidance
suggests that a very narrow ribbon of SB-instby will develop
immediately ahead of the southward-progressing outflow-driven
storm activity into mid-afternoon, supporting locally gusty to
damaging winds with the strongest cores. This will especially be
the case for areas near/W of I-75 and especially near/W of I-71
with the better instby to work with than for locales in NE KY
or the lower Scioto Valley. The better SB instby should pinch
off with eastward extent.

The rapid jump in temps/humidity/SB instby early/mid afternoon
in the wrn third of the ILN FA may be enough to prompt and
maintain a more concerning severe threat into the local area
than was originally expected. At this juncture, it is likely
that additional clusters or complexes of storms will develop
within the trailing MCS boundary, spreading to the SSE through
the local area between about 17z-23z (N-S). Given the robust
destabilization efforts underway near/W of I-75/I-71 prior to
storm arrival, it is certainly worth mentioning the potential
for widespread gusty to locally damaging winds this afternoon
into early evening. A high DCAPE environment amidst favorable
LL/deep-layer thermodynamic fields and potential for aggressive
cold-pool driven processes suggests that these storms could be
locally intense and persist for quite a long time, even in the
absence of any synoptic-based forcing or source for lift. Feel
that the SPC slight risk on the SWODY1 in our west is well-
warranted and needed.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
The fcst for this evening through Wednesday following the
expectation for daytime convection becomes even muddier,
unfortunately. It seems plausible, given the latest data, that
there will be a several hour lull in pcpn locally following the
afternoon/early evening storms. This lull should stretch past
midnight into the middle of the night before additional loosely-
organized activity moves back in from the W by/after 06z-09z.
The storms tonight are likely to be much more disorganized and
not pose such a potential for strong/severe activity. However,
any of this activity will bring with it the potential for some
lightning and very heavy downpours/localized ponding of water.

Coverage of SHRA/TSRA should be on the increase toward daybreak
and beyond, but there are quite a few uncertainties in how
things will unfold on Wednesday in terms of a hazardous-weather
perspective.

There is likely to be better forcing moving E through the
region Wednesday morning through the daytime, potentially too
much so. In fact, in an uncapped environment, the focus for any
organized storms appears rather nebulous (except along the SE-
moving front very late in the day), potentially leading to a
somewhat "grungy" environment characterized by poor LL (and
midlevel) lapse rates. This would suggest that storms/updrafts
may struggle to become particularly intense, with much more in
the way of widespread storms, with only a few becoming strong to
severe briefly. There will be slightly better LL and deep-
layer flow fields to work with Wednesday, but the poor deep-
layer lapse rates and slightly less unstable environment cast
some doubt onto the coverage of /severe/ storms.

Rainfall through the period will be highly-variable, both in
time and space, but would expect that some spots will pick up
1-2 inches between now and Wednesday evening, especially with
the anomalously-high PWATs expected region-wide for the daytime
Wednesday.

 

[NWOhioChaser]

Nice bowing segment coming down my way. It was super intense coming off the lake but is slowly weakening. I still expect maybe a good rumble of thunder and some gusty winds though. Under a severe thunderstorm watch until noon. Muggy and already 76 degrees with a DP of 65. Definitely feels like rain is coming

Edited June 25 by NWOhioChaser

[BuckeyeGal]

1 hour ago, snowlover2 said:

ILN

 

Strongly worded..

[snowlover2]

NW OH is out of the slight but more of SW OH is in it.

[junior]

Getting some scattered development here as the OFB races south. 

 

Good downpour and some thunder here.

Edited June 25 by junior

[ClicheVortex2014]

Severe storm about to impact NWS Amarillo. Will be interesting to see what happens.

 

[ClicheVortex2014]

4 minutes ago, ClicheVortex2014 said:

Severe storm about to impact NWS Amarillo. Will be interesting to see what happens.

 

The mesonet at Amarillo 9NNE just recorded a 79 mph wind gust 😳

[ClicheVortex2014]

10 minutes ago, ClicheVortex2014 said:

The mesonet at Amarillo 9NNE just recorded a 79 mph wind gust 😳

NWS Amarillo gusted to 78 mph