2019 Short/Medium Range Severe Weather Thread

[metallica470]

New warning says confirmed tornado over Lewistown

[SchaumburgStormer]

1 minute ago, metallica470 said:

New warning says confirmed tornado over Lewistown

Velocity doesn’t look great at the moment. May be cycling 

[metallica470]

3 minutes ago, SchaumburgStormer said:

Velocity doesn’t look great at the moment. May be cycling 

Yea, looks like it let up right around Lewistown which would be good news

[Hoosier]

Some clearing spreading from Iowa into western IL.  Should get a nice bump in temps in northern IL later.  I do wonder if somewhat greater severe chances could set up in the central/southern LOT cwa compared to farther north, but it's a bit unclear. 

[purduewx80]

Just now, Hoosier said:

I do wonder if somewhat greater severe chances could set up in the central/southern LOT cwa compared to farther north, but it's a bit unclear. 

Totally agree; 12Z 3km NAM may have the best idea, but nothing has really captured the warm sector staying as far S as it is now. That warm front will be hard to budge w/ the new sfc-based severe storms riding it.

[Indystorm]

Think the location of svr as always depends on where that WF lines up geographically but Chicago web page is expecting svr storms in the 4-7 p.m. time frame in their area and then overnight.

[Indystorm]

73/62 IKK and se wind with new cells popping south of I-74 in advance of the tornado warned cell.

[Hoosier]

Warm front is still pretty far south.  

On a more localized scale for parts of IL/WI, the E/SE flow off of a relatively cool Lake Michigan should further limit a tornado threat close to the lake.

[Indystorm]

Ya, that WF position makes me a little nervous for central IN later on today.

[King James]

73/62 IKK and se wind with new cells popping south of I-74 in advance of the tornado warned cell.

I ended my day earlier and I’m just hanging out, I’m about an hour from my house. Is this something I might want to be at home for?

[janetjanet998]

HRRR still struggling ....storm is still a hair too far north and weakens it fast ..models and most forecasters clueless

you could tell from the visible Sat.  what was going to happen the past couple of hours...there is a mini "warm front" of CU popping up east of the storm and a mini "cold front"  of CU SW of the storm 

think of the storm as a low and these fields are the fronts..with bubbling CU in the "warm sector"

the storm is also slowing down...if this area because a complex then it will throw sinking air back NW of it and kill off any later afternoon storms

 

 

[Malacka11]

Mammatus, right?

[Indystorm]

Latest SPC update

 Farther north, isolated supercells should also persist within warm
   advection zone across IL. This activity could develop a bit north
   into the early evening as warm front advances into southern
   WI/southern Lake MI.

   ..Darrow.. 05/24/2019         Must have stronger confidence than I do that the WF will surge north.

[Stebo]

1 minute ago, Indystorm said:

Latest SPC update

 Farther north, isolated supercells should also persist within warm
   advection zone across IL. This activity could develop a bit north
   into the early evening as warm front advances into southern
   WI/southern Lake MI.

   ..Darrow.. 05/24/2019         Must have stronger confidence than I do that the WF will surge north.

LLJ will do wonders, I agree with their take.

[Stebo]

1 hour ago, janetjanet998 said:

HRRR still struggling ....storm is still a hair too far north and weakens it fast ..models and most forecasters clueless

you could tell from the visible Sat.  what was going to happen the past couple of hours...there is a mini "warm front" of CU popping up east of the storm and a mini "cold front"  of CU SW of the storm 

think of the storm as a low and these fields are the fronts..with bubbling CU in the "warm sector"

the storm is also slowing down...if this area because a complex then it will throw sinking air back NW of it and kill off any later afternoon storms

 

 

Score one for the HRRR, storm went poof

[Hoosier]

We don't have a big convective complex ongoing, so there is really nothing to hold back the warm front from making a significant northward push from where it currently is.  Question I have for later this evening is how long storms will remain surface based/near surface based.  The pressure gradient is not all that strong to keep the low levels well mixed after dark... on the other hand, the airmass near/south of the warm front is quite moist to keep the amount of nocturnal cooling somewhat in check so could envision a wind/tornado threat lingering into the overnight... at least isolated.

[Hoosier]

Definite northward progress since last time I posted the map

 

[janetjanet998]

44 minutes ago, Stebo said:

Score one for the HRRR, storm went poof

yep.... LOT was expecting it to continue also

 

 

THIS HAS BEEN EVIDENT WITH A PERSISTENT SEVERE STORM   MOVING EAST THROUGH CENTRAL IL. THIS STORM HAS BEEN RIDING EAST   ALONG THE WARM FRONT, WHERE UPPER 60S TO LOW 70S DEWPOINTS   CURRENTLY RESIDE. DON'T SEE ANY REASON WHY THIS WON'T CONTINUE TO   PERSIST, ESPECIALLY AS LARGE SCALE ASCENT WILL LIKELY INCREASE   OVER THE NEXT COUPLE OF HOURS

 

There are cells going up in IA but they are moving NE..

there might be an outflow boundary from the old storm back to Northern MO into the cluster by MCI...that may light up soon

but so far not much CU development over Northern IL

note: I am focusing on Northern central IL area 

[janetjanet998]

Its odd cells aren't developing yet over IL., NE MO ..like they are out in the plains ...

these would moving into N IL if they did develop

HRRR wants to develop a couple of super cells near IKK but so far not much ..even CU wise

 

edit 4:55pm: small CU field may be going up now over western IL around UIN

 

here SPC talks about the Northern MO area

 

MOZ000-KSZ000-242230-  
  
MESOSCALE DISCUSSION 0774  
NWS STORM PREDICTION CENTER NORMAN OK  
0356 PM CDT FRI MAY 24 2019  
  
AREAS AFFECTED...NORTHERN MO  
  
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE   
  
VALID 242056Z - 242230Z  
  
PROBABILITY OF WATCH ISSUANCE...40 PERCENT  
  
SUMMARY...TRENDS WILL BE MONITORED FOR INCREASING THUNDERSTORM  
COVERAGE AND A WATCH MAY BE NEEDED TO COVER THE RESULTING THREAT FOR  
HAIL, DAMAGING WIND GUSTS, AND POSSIBLY A FEW TORNADOES.  
  
DISCUSSION...AIR MASS ACROSS NORTHERN MO CONTINUES TO DESTABILIZE AS  
STRONG DIURNAL HEATING OCCURS AMIDST AMPLE LOW-LEVEL MOISTURE.  
VISIBLE SATELLITE IMAGERY SHOWS A NEWLY DEVELOPED CUMULUS FIELD EAST  
OF KANSAS CITY, WITH A FEW ATTEMPTS AT DEEPER CONVECTION NOTED. AS  
THE AIR MASS FURTHER DESTABILIZES, EVENTUAL CONVECTIVE INITIATION IS  
ANTICIPATED. ENVIRONMENT IS CHARACTERIZED BY MODERATE INSTABILITY  
(I.E. MLCAPE AROUND 1500 J/KG) AND AMPLE VERTICAL SHEAR (I.E.  
EFFECTIVE BULK SHEAR OF 40-50 KT) FOR SUPERCELLS, WITH LARGE HAIL  
AND DAMAGING WIND GUSTS AS THE MAIN HAZARDS. A TORNADO OR TWO IS  
ALSO POSSIBLE. IN ADDITION TO IN SITU CONVECTIVE INITIATION,  
UPSTREAM THUNDERSTORMS ACROSS EASTERN KS MAY EVENTUALLY MOVE INTO  
NORTHWESTERN KS OVER THE NEXT FEW HOURS. TRENDS WILL BE MONITORED  
FOR POSSIBLE WATCH ISSUANCE.  

 

 

[King James]

Sun just came out near IKK. Wife called me to bring a hair tie to dinner because it’s getting humid. Definitely a change the last hour

[CoalCityWxMan]

Just now, King James said:

Sun just came out near IKK. Wife called me to bring a hair tie to dinner because it’s getting humid. Definitely a change the last hour

Yup, highest dews of the year so far. Feels kinda nice. Has that “juicy” feel to it where this morning it felt chilly. 

[janetjanet998]

something trying to go up NE of UIN..should head my way if it develops

NOTE: In Northeast Peoria county at Three Sisters Park, which is between Chillicothe and Rome, Summer fest is ongoing ....1000's of people mostly in tents some of those in wooded areas...alot drunk some on other stuff too ...not enough shelter for all of them ..any big winds could be bad news

[Hoosier]

3 minutes ago, King James said:

Sun just came out near IKK. Wife called me to bring a hair tie to dinner because it’s getting humid. Definitely a change the last hour

Sun out here too.  Might be able to pull off about a 4-7 degree rise (?) in temps as we take advantage of late day insolation before temps slowly fall.

[King James]

Sun out here too.  Might be able to pull off about a 4-7 degree rise (?) in temps as we take advantage of late day insolation before temps slowly fall.

77/70 here

[purduewx80]

getting good pressure falls near and north of the warm front now, which is allowing the bubble high over chicagoland to to weaken and shift northeast over the lake. 

there is also subsidence behind the earlier convection, which will be replaced w/ lift and fairly widespread convection later in the evening as the LLJ increases. severe weather is possible but i'd think some flash flooding is probably the bigger threat across MO, IA, IL and maybe southern WI overnight.

[Hoosier]

8 minutes ago, King James said:

77/70 here

Full disclosure, JOT went up 4 degrees in the past hour which was the basis for my guess. I really don't know how much of a rise there will be.  

[Indystorm]

Storms beginning to fire around Macomb and in ne MO radar hole area.  Wondering if northern MO will be put under a tornado watch for storms approaching from KC or for development farther east.

[Hoosier]

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
556 PM CDT Fri May 24 2019

.MESOSCALE DISCUSSION...
553 PM CDT

The weather forecast over the next 12+ hours remains fairly
complicated, and uncertainties abound mainly due to the weak
nature of large-scale forcing for ascent. While a threat for
strong to severe thunderstorms certainly exists this evening and
into the nighttime hours, how this threat materializes remains
tied to mainly subtle mesoscale processes and subtle waves of
synoptic ascent which are both difficult to diagnose and pinpoint
with much certainty.

Surface analysis late this afternoon depicts a northwest to
southeast arcing warm front--reinforced by this morning`s
convection which laid out an outflow boundary--likely just
entering portions of La Salle, Livingston, and Ford Counties.
Dewpoints immediately to the south of this boundary jump into the
70s with breezy south to south-southwesterly winds, and this
seems to be demarcated pretty well by an area of bubbling Cumulus
and HCRs which are steadily building northward. Recent RAP
soundings and SPC mesoanalysis reveal that this is a relatively
high-quality warm sector, with mean mixing ratios pushing 16 g/kg
and decent moisture through a fairly deep layer (up to 700 mb). An
earlier tornadic supercell, which was riding along the northern
extent of this warm frontal boundary, quickly dissipated a few
hours ago as it approached Bloomington, likely as it encountered a
pocket of warmer air aloft with 700 mb temperatures analyzed at
+9 to +10C. This is indicative of lingering capping, which has
thus far suppressed any additional convective initiation attempts
in the warm sector. Recent GOES-16 visible satellite loops reveal
some towering Cu development taking place across West Central
Illinois, however, where capping is lower due to cooler
temperatures aloft.

Farther to our west, an additional area of bubbling cumulus has
been noted across central and eastern Iowa, although recent radar
trends suggest incipient updrafts are struggling to develop.
Large scale forcing for ascent is not strong here, but modest
mid-level height falls (20-40 m/12 hours) are noted in recent
analyses nosing into far northwestern Iowa at the leading edge of
a very subtle shortwave. It`s possible some lingering mesoscale
subsidence is still in place across eastern Iowa in the wake of
this morning`s MCS, tempering additional robust convective
development at this juncture, but conditions do appear favorable
for robust updraft development over the next few hours.

With this all laid out, it does appear there may be two favored
corridors for potential convective development over the next few
hours: /1/ near and south of the incoming warm front and /2/
across eastern Iowa. All modes of severe weather would be possible
across our area, including the threat for a few tornadoes. Deep
layer shear in excess of 50 kts will support rotating storms and
supercell structures and sizable CAPE in the hail growth zone
will foster large hail development, potentially to the size of
golf balls or even larger with some analogs supporting 2"+ hail
not out of the question.

Recent runs of the HRRR have been a bit concerning, developing
robust storms near the incoming warm front and into the I-80
corridor. Locally backed surface flow would support a tornadic
potential with these storms as they interact with the front and
gain access to considerable streamwise vorticity. Think it looks
too aggressive based on latest satellite trends, but we will need
to keep our eyes peeled for development near and south of I-80
during the 8 to 11 PM time frame. The other area of convection--to
our west in eastern Iowa--may attempt to develop into our western
counties later this evening, likely after 10 PM or so. A tornado
threat will continue here, although CAM guidance indicates some
propensity for storms to congeal into clusters which may
eventually deliver more of a damaging wind and hail threat as this
second area of activity pushes eastward into the overnight hours.

Finally, a flash flood potential does exist this evening and
overnight, although the spatial breadth and magnitude of this
threat still is uncertain due to the mesoscale processes involved.
Current thinking is that the Flash Flood Watch captures the
favored corridor well, and no immediate changes are planned.

Carlaw

[Indystorm]

I now see that northern MO has been placed under a tornado watch till midnight central time.

[Indystorm]

That was fast

 

BULLETIN - EAS ACTIVATION REQUESTED  
TORNADO WARNING  
NATIONAL WEATHER SERVICE QUAD CITIES IA/IL  
618 PM CDT FRI MAY 24 2019  
  
THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A  
  
* TORNADO WARNING FOR...  
  NORTHEASTERN KEOKUK COUNTY IN SOUTHEASTERN IOWA...  
  SOUTHWESTERN JOHNSON COUNTY IN EAST CENTRAL IOWA...  
  NORTHERN WASHINGTON COUNTY IN SOUTHEASTERN IOWA...  
  SOUTHEASTERN IOWA COUNTY IN EAST CENTRAL IOWA...  
  
* UNTIL 700 PM CDT.  
      
* AT 618 PM CDT, A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO  
  WAS LOCATED NEAR KINROSS, OR 19 MILES NORTHEAST OF SIGOURNEY,  
  MOVING EAST AT 25 MPH.  
  
  HAZARD...TORNADO AND HALF DOLLAR SIZE HAIL.  
  
  SOURCE...RADAR INDICATED ROTATION.  
  
  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.  
  
* THIS DANGEROUS STORM WILL BE NEAR...  
  WELLMAN AROUND 625 PM CDT.  
  KALONA AROUND 645 PM CDT.  
  UNIVERSITY HEIGHTS, HILLS AND OAKDALE AROUND 700 PM CDT.  
  
OTHER LOCATIONS IMPACTED BY THIS TORNADIC THUNDERSTORM INCLUDE IOWA  
CITY MUNICIPAL AIRPORT, FRYTOWN, WINDHAM, AMISH, JOHNSON COUNTY  
FAIRGROUNDS, HOLBROOK, COSGROVE AND SHARON CENTER.