2019 Short/Medium Range Severe Weather Thread

[Indystorm]

16 minutes ago, cyclone77 said:

Numerous 1" hail reports coming out of the IL QCA the past hour or so.  We were under a warning for those storms but they are quickly crapping the bed, warning cancelled.  Did give us a nice light show in the western/southwestern sky the past hour or so. 

Was wondering if you were able to view the spectacle.

[yoda]

Looks like a new watch coming soon for IL and IN

[yoda]

1 minute ago, yoda said:

Looks like a new watch coming soon for IL and IN

And there it is, till 7am... small watchbox of only 15 counties though

[bowtie`]

Got to love Mother Natures alarm clock. Took two close lightning strikes and had a fair blow. Think I will try and go back to sleep now. I had no intensions of getting up this early. It is my day off.

[hawkeye_wx]

Tuesday evening looks pretty active over here.  We're in the enhanced area now, but Des Moines thinks a further upgrade is possible.

[janetjanet998]

another busted MCS fail and LOT flood watch 

HRRR as late as 10z had very heavy rains and intense storms in the current cluster over me.....which is nothing but light to moderate rain right now

 I don't understand why models had this holding ins own all night then go poof again over N IL...im talking about the bigger one over MCI last evening not the smaller lead one 

usually these don't start to weaken  until 6-7am or so....not 1-2am

[Chambana]

Multiple large trees uprooted in and around the Champaign-Urbana area. I’m just going to assume the very soggy ground is contributing to the uprooted trees, we gusted to 63mph last night.

[SchaumburgStormer]

Good amount of damage in the Argenta-Oreana area in Macon county from last night. Luckily my parents had no damage, but quite a bit of large tree damage throughout town. May have spun one up pretty quickly along the line as it passed over Oreana. 

[hawkeye_wx]

23 hours ago, hawkeye_wx said:

Tuesday evening looks pretty active over here.  We're in the enhanced area now, but Des Moines thinks a further upgrade is possible.

Well, so much for that.  The severe potential has been shifted south and west.  We've been downgraded.

[Chambana]

Not one, not two, but THREE EF-1 tornadoes confirmed in Champaign county early Sunday morning per the NWS. One of the tornadoes that hit Urbana had winds of 90-100mph. Pretty impressive. 

[IWXwx]

This morning's 3k NAM really pumps up the SB/MUCAPE into the 4000J/kg range in Northern Indiana tomorrow afternoon and depicts quite the squall line stretching across the state and dropping straight south from the IN/MI state line and moving well into southern IN before weakening.

I can foresee SPC extending their slight risk through Indiana into Ohio as well as up into the ORD area with the afternoon Day 2 for winds.

[Hoosier]

1 hour ago, IWXwx said:

This morning's 3k NAM really pumps up the SB/MUCAPE into the 4000J/kg range in Northern Indiana tomorrow afternoon and depicts quite the squall line stretching across the state and dropping straight south from the IN/MI state line and moving well into southern IN before weakening.

I can foresee SPC extending their slight risk through Indiana into Ohio as well as up into the ORD area with the afternoon Day 2 for winds.

It does look slight risk worthy.

[Hoosier]

Upgraded to enhanced farther south/west

 

Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1234 PM CDT Fri May 31 2019

   Valid 011200Z - 021200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM KANSAS
   INTO A PORTION OF THE MIDWEST...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER A PORTION OF
   THE SOUTHERN PLAINS...

   ...SUMMARY...
   Scattered severe storms are possible Saturday afternoon central and
   eastern Kansas, northern Oklahoma, Missouri, Illinois and extreme
   southeast Iowa. Other more isolated strong to severe storms are
   possible from the southern through central High Plains. Large hail
   and damaging wind will be the primary threats.

   ...Synopsis...

   Shortwave trough now over the northern High Plains will become
   absorbed within the amplifying northern stream and move southeast
   through the Midwest region Saturday. Cold front initially from the
   upper Great Lakes through western KS will move southeast, and by
   early evening should extend from the southern Great Lakes, northern
   MO into southeast CO where it will likely stall. 

   ...Central Plains through the Midwest regions...

   The atmosphere from KS through the Midwest is expected to become
   moderately to strongly unstable Saturday afternoon with 2000-3000
   J/kg MLCAPE supported by the northeast advection of low-mid 60s F
   dewpoints through the warm sector beneath plume of steeper (7-7.5
   C/km 700-500 mb) lapse rates. Some model solutions are overdone with
   low-level dewpoints by several degrees, apparently due to excessive
   evapotranspiration, but correcting for this still supports moderate
   to strong instability as the surface layer warms during the
   afternoon. Widely scattered to scattered storms are expected to
   initiate along the cold front by mid afternoon as the boundary layer
   destabilizes and the cap weakens. Northwesterly winds will
   strengthen to 40+ kt at 500 mb, especially from eastern KS through
   central IL as height gradient increases in association with the
   amplifying upper trough. This will support 35-40 kt effective bulk
   shear. Both supercell and multicell storm modes are expected with
   initial discrete storms eventually consolidating into lines or
   clusters as they spread southeast. Damaging wind and large hail will
   be the main threats.  

   ...Southern High Plains...

   Storms are expected to once again develop over the higher terrain of
   NM and southwest TX and subsequently spread east into the High
   Plains. Have introduced a slight risk over this region where a belt
   of somewhat stronger winds aloft and moderate instability will
   promote a parameter space sufficient for a few supercells capable of
   large hail and damaging wind.

   ...MAXIMUM RISK BY HAZARD...
   Tornado:   2%     - Marginal
   Wind:     30%     - Enhanced
   Hail:     30%     - Enhanced

   ..Dial.. 05/31/2019

[RyanDe680]

Slight shift north on the slight risk for today 

[IWXwx]

Could the filtered sun due to the smoke dampen convective perimeters as compared to what the CAMs are predicting?

[RCNYILWX]

IMO using the baseline of the issued Enhanced Risk, placement should either be shifted north into northern IL or expanded from current area to include northwest 2/3 of LOT CWA. Based off path of well defined shortwave tracking across the area around mid afternoon, strongest mid-level winds and deep layer wind shear will be across northern IL and southern WI. There will be more than enough instability area wide and very steep lapse rates, considering that we already had pretty stout elevated hailers this morning over northern IL and southern WI.

Looks like a solid early summer severe day, with large to isold sig hail with initial discrete/semi discrete storms likely trending to more of a damaging wind risk if things as expected congeal/grow upscale. Doesn't look like much of a tornado threat with weak low level winds, little/no directional shear, and soundings showing well mixed low levels. Would likely need outflow boundary interaction for any brief tor threat, or possibly in proximity to the weak surface low moving over southern WI.

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[RCNYILWX]

Could the filtered sun due to the smoke dampen convective perimeters as compared to what the CAMs are predicting?

Doesn't seem like the smoke should dampen insolation and thus instability too much. Even with pretty thick smoke yesterday we got to low-locally mid 80s highs without a problem.

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[Hoosier]

1 hour ago, IWXwx said:

Could the filtered sun due to the smoke dampen convective perimeters as compared to what the CAMs are predicting?

Dews coming in under guidance would temper instability some, as has been mentioned in the discussions. Haven't checked to see how the CAMs are handling dews.

[Hoosier]

1 hour ago, RCNYILWX said:

IMO using the baseline of the issued Enhanced Risk, placement should either be shifted north into northern IL or expanded from current area to include northwest 2/3 of LOT CWA. Based off path of well defined shortwave tracking across the area around mid afternoon, strongest mid-level winds and deep layer wind shear will be across northern IL and southern WI. There will be more than enough instability area wide and very steep lapse rates, considering that we already had pretty stout elevated hailers this morning over northern IL and southern WI.

Looks like a solid early summer severe day, with large to isold sig hail with initial discrete/semi discrete storms likely trending to more of a damaging wind risk if things as expected congeal/grow upscale. Doesn't look like much of a tornado threat with weak low level winds, little/no directional shear, and soundings showing well mixed low levels. Would likely need outflow boundary interaction for any brief tor threat, or possibly in proximity to the weak surface low moving over southern WI.

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Yeah, the threat in northern IL looks as decent if not better than where the ENH is currently placed.

[nwohweather]

Dews coming in under guidance would temper instability some, as has been mentioned in the discussions. Haven't checked to see how the CAMs are handling dews.

Yeah was gonna say dewpoint matters way more than pure air temperature. Instability by definition is how fast an water molecule cools with height

[Hoosier]

The boundary that just went through Chicago *could* locally enhance the tornado threat a little for anything tracking along it later... wherever it is by then.

[janetjanet998]

as others have pointed out..dewpoints lower then modeled

 

The corn crop should be sprouting by now in a normal year and add moisture to the air from here on out...

even though the ground is wet ...I wonder if models will be too high on dew points in the coming weeks since most of the corn isn't even planted yet

 

also will that complex in MI throw back sinking air back west?

[janetjanet998]

latest HRRR fires ZERO convection over downstate IL in the enhanced area

[Hoosier]

14 minutes ago, janetjanet998 said:

as others have pointed out..dewpoints lower then modeled

 

The corn crop should be sprouting by now in a normal year and add moisture to the air from here on out...

even though the ground is wet ...I wonder if models will be too high on dew points in the coming weeks since most of the corn isn't even planted yet

 

also will that complex in MI throw back sinking air back west?

I'm wondering that too.  Not sure if the models get continuous input on the state of the vegetation.

[Chinook]

Some 55-60 dBz severe-warned storms near Wyandotte, MI. I wonder if we will get a report from Michsnowfreak on this.

[Powerball]

It seems like for the first time in forever, Detroit is finally getting some severe action.

[Hoosier]

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
203 PM CDT Sat Jun 1 2019

SHORT TERM...
155 PM CDT

Through Tonight...

An outflow/lake breeze composite boundary has pushed inland to
near a Woodstock to Naperville to Wheeler line based on latest
surface observations. The airmass to the east and north of this
boundary has been stabilized, with dewpoints in the upper 50s and
temperatures in the upper 60s. This stabilization is also
demarcated by stable wave clouds on GOES-16 visible satellite
imagery. Latest guidance does indicate the breezier synoptic
southwesterly flow may force this boundary back east a bit through
the afternoon hours, and how this modified airmass impacts the
severe potential into portions of Lake (IL) and Cook counties
remains a bit uncertain at this time. Recent ACARS soundings out
of Midway show this stable layer is pretty robust, with a notable
temperature inversion present near the surface. With additional
diabatic heating, would expect at least some airmass recovery on
the cool side of this boundary with baroclinicity starting to wash
out a bit over the next 1 to 3 hours. If this boundary remains
robust, however, it could locally mute the severe threat into Cook
and Lake counties later this evening by limiting the potential
for strong downdrafts and associated winds to reach the surface.

The other question stems around a notable pocket of dry air now
being analyzed in the 850-700 mb layer with 850 mb dewpoints under
0 C now being analyzed across portions of northwestern Illinois
and into our far western counties. This could tend to work against
updraft intensity--at least initially--although an axis of much
higher moisture is analyzed near I-90. With surface temperatures
having warmed into the 80s, dewpoints in the lower 60s, and steep
mid-level lapse rates in place overhead, MLCAPE values are,
nonetheless, inching past 2000 J/kg early this afternoon,
especially near and west of the I-90 corridor. Mid-level winds
are also increasing ahead of a small but sharp shortwave, and
effective deep layer shear values are pushing north of 30-35 kts
across the region (lower south of I-80, highest north). 500 mb
height falls on the order of 50-60 m/12 hr have been noted
spreading towards southern Wisconsin. Associated increases in
forcing for ascent will be responsible for expanding showers and
thunderstorms along and incoming cold front through the evening
hours. All of this taken together spells a continued threat for
strong to severe storms across our region this afternoon. Hi-res
guidance continues to struggle with a rather wide disparity in
solutions still noted this afternoon.

Storms are beginning to develop across southwestern Wisconsin at
this hour, near a developing weak surface low and at the leading
edge of stronger ascent from the incoming shortwave. Latest
thinking is that storms will continue to develop south and
westward over the next hour or two, eventually nearing Winnebago,
Ogle, and Lee counties towards 4 PM or so. Additional convection
is also attempting to develop along the aforementioned
outflow/lake breeze across southern Cook and into Lake (IN) and
Porter counties. The airmass immediately ahead of this boundary is
unstable and only weakly capped, so we will need to keep an eye on
this area for potential storm development as well. Initial
discrete/isolated activity will carry a risk for large hail
(potentially up to ping pong-golf ball sized), but storms should
quickly begin to congeal into line segments as robust forcing
overspreads the area. As a result, the severe threat will begin to
transition to mainly wind damage, with a potential for 60-70 mph
wind gusts. At this time, think the main severe corridor may end
up developing near and north of I-80, and particularly focusing
along I-88 and I-90 where instability will be maximized. The
tornado threat is low from a synoptic standpoint with minimal
low-level hodograph curvature, but we will be keeping an eye on
any stronger updrafts which manage to develop near this feature
later this afternoon. A brief tornado spin-up or two can`t be
ruled out in the vicinity of this boundary, but the main severe
risk still appears to be from hail and damaging winds.

Looks like a surging line of storms will move out of our south and
eastern counties by mid-evening with a continued threat for strong
to locally damaging wind gusts. Will be holding onto some low PoPs
behind this line of storms with lingering moisture and some
instability to work with, but the main severe window will come to
a close by about 9-10 pm area-wide.

Carlaw

 

[Hoosier]

20z outlook expresses some doubts about convective coverage in the ENH area.

[CoalCityWxMan]

Storm with a pretty healthy hail core moving into the center of the metro

[RyanDe680]

Just now, CoalCityWxMan said:

Storm with a pretty healthy hail core moving into the center of the metro

Was just under that.  No wind.  Heavy rain though (0.25 in about 10 minutes) and penny hail.  Decent storm.