4/2/06 NOW: Midwest/Southern Plains/TN and OH Valleys

[Brett Adair]

SVR Tstorm Watch 129 has been issued for portions of SE TX and Tornado Watch 130 has been issued for portions of MO/SE IA/WRN IL. Rotating midlevel wave is ejecting out into western Missouri where explosive development is possible along the dryline orientation across west/central Missouri within the next couple of hours. Shear/Instability are both adequate for the formation of supercell thunderstorms and mesocyclogenesis this afternoon across this area.

 

[HAltschule]

Looks like initiation is starting to occur across Southwest MO and also in Central MO. TCU's are popping and about to develop Precipitation bases. Radars should fill in pretty rapidly as cells develop and form into lewps and bows.

EDIT: 18z Sounding from Springfield, MO shows a 3 degrees cap present. LI's are -7 and the environment is a "loaded gun" sounding. Once these cells break the cap they will become rapidly severe. SRH is still around 230-260 in the area, so supercells are likley but organized, persistent tornadic storms are not.

 

[nickgrillo]

Hmmm... Why aren't storms likely to persist? There is strong 0-6 km deep-layered shear to keep any storm sustained and strong and plenty of boundary layer veering near the warm front (with backed sfc flows existing in northern MO -- yielding stronger SR inflow, in turn increasing SR helicity and tornadic potential -- in the midst of strong surface-based CAPE also present).

I am currently in Boone, MO -- right off of I-70 and I'm not particularly liking the environment down here (slightly more veered sfc flow here further south in the warm sector) and I am likely gonna head north to nc MO closer to the warm front (where at least 1000j/kg of SBCAPE and 250m2/s2 0-1 km SRH exists, per SPC mesoanalysis) with strong insolation occuring across the area along and south of the warm front -- further diabatically destabilizing the troposphere (with stronger CAPE progged by the RUC and NAM to develop within the next few hours).

Deepening cumulous around here continues to indicate CIN is weakening -- with boundary layer parcels beginning to reach their LFC (initiating deep, moist convective clouds) and any storms that develop should have the potential to produce very large hail and quite likely a couple tornadoes, particularly slightly further north near the warm front.

 

[HAltschule]

Hmmm... Why aren't storms likely to persist? [/b]

I think we are interpreting what I was trying to say differently. Undoubtedly there will be sustained and persistent supercells, but I was trying to imply that I don't believe the persistent long-lived tornadoes within those supercells will exist. There was some talk yesterday about a High Risk for today and for the PDS wording in the tornado watches, but I just don't see that kind of risk this afternoon. I do expect to see some isolated tornadoes this afternoon if, for no other reason than Missouri has been the tornado hotspot this season so far.

As we speak, scattered storms are popping pretty quickly in MO and seem likely to go severe soon.

 

[HAltschule]

Wow, no kidding. Looks like Des Moines, IA will be threatened by some warm frontal convection/isolated tornado threat in the next hour or two. Nice arc of storms firing just to the south and heading due north.

 

[Alex Lamers]

Watch out for the storm near Osceola, Iowa in Clarke County. It's interesting in that its mean storm motion is about 25-30º right of the rest of the storms. Based on 19z mesoanalysis it is also firmly in place right ahead of the low on the warm front. Watching for rotation but I can't see any - yet.

 

[Alex Fisher]

I'm sitting in New Sharon, IA...15 miles south and 45 miles east of des moines....intermittent clearing here right now. Any recommendations on what storm I should get on? My internet is limited here so I cant get radar very often.

 

[MatthewCarman]

I live in Jasper County Iowa and a tornadic storm is moving northeast from Warren county so I could be put under the warning soon. I will post and let you all know everything is ok after the storm passes by. I have to go my noaa all hazourds weather radaio siren just went off. See you all later and let you all know if I see a tornado.

 

[HAltschule]

Exactly my thoughts. The cell south of DSM does not show any tornado signatures to me. Not sure why it's warned unless they have public reports. There is a cell approaching Bloomfield, IA that looks sweet. Severe Supercell that could attain isolated tornadic potential. If you high tail it to get ahead of that storm...that might be the best way to go. From there South you can take your pick but I would not bother with the stuff heading toward DSM.

EDIT: This storm approaching Bloomfield just went Tornado Warned.

 

[Brandon Clement]

The storms that are firing in extreme Northern Arkansas are really grabbing my attention. It looks as though they will stay discrete and they are working with cape values between 2000-3000 and 50 knots of effective shear. I like the Marion County storm but terrain and roads would make quite a difficult chase on that sup. It is now severe warned in a newly issued tor watch and looks to me moving more towards due east the last few frames.

 

[Alex Lamers]

For those of you who are way out of position, you may want to consider the Muscatine, Iowa area just SW of Davenport. It's cleared out considerably in the past hour. Thetae advection bullseye nosing into the area and nicely backed wind flow ahead of the warm front that is now just south of that area. Davis Co. cell still looks decent.

 

[HAltschule]

Agreed, Brandon. The Northern Arkansas cell has the best rotation and has 3.25" hail with it. The other cell with 2.50" hail is southeast of Springfield, MO. All of these are discrete and look nasty. Hopefully a couple of people are chasing in Southern MO and Northern AR.

EDIT: Cell near Montgomery City, MO has rapidly acquired a hook echo appearance and shows rotation. This cell is discrete and has 2.75" hail. Another potential nader producer.

 

[Brandon Clement]

The storm to the northwest of Little Rock is looking very healthy. The last frame on the radar it looks like it is trying to show a hook. I'm pretty sure we will be seeing it go from severe to tor warned shortly.

radar

EDIT: No sooner than I say something the storm rapidly weakens in two radar frames. Will be interesting to see if it is just in a cycle period and it looks like it could split.

 

[HAltschule]

"Cell near Montgomery City, MO has rapidly acquired a hook echo appearance and shows rotation. This cell is discrete and has 2.75" hail. Another potential nader producer."

This cell has become particularly nasty within the line and has 3.00-3.50" hail with it. Decent G2G shear has developed and it will be tracking through the Northern suburbs of St. Louis, MO in the next hour or so. This one is def. worth watching. The rest of the line is quite impressive as well.

St. Louis, MO Webcam link: http://www.wustl.edu/webcam/

 

[Benjamin Sipprell]

"Cell near Montgomery City, MO has rapidly acquired a hook echo appearance and shows rotation. This cell is discrete and has 2.75" hail. Another potential nader producer."

This cell has become particularly nasty within the line and has 3.00-3.50" hail with it. Decent G2G shear has developed and it will be tracking through the Northern suburbs of St. Louis, MO in the next hour or so. This one is def. worth watching. The rest of the line is quite impressive as well.

St. Louis, MO Webcam link: http://www.wustl.edu/webcam/
[/b]

I'll keep you posted ... now living in Lake St. Louis region just west of St. Charles ... lots of rumbling, getting dark to the west ... if I wasn't moving into my apartment and unpacking I would be chasing ... I haven't showered since Thursday!

My car!