Wednesday appears to be shaping up as a decent severe weather day for the pandhandle and into southwest and southcentral Nebraska. A boundary will be sagging south into the area with a surface low setting up in same general region. Deep layer shear will not be overwhelming but in the neighborhood of 35-40 kts. Surface moisture appears to have dewpoints in the 65 to almost 70 degree range, with MLCAPE values approaching 3500 J/kg. Helicity also appears to be sufficient for supercell development with values approaching 300-400 in the target area. I'm including eastern WY as it will be in the post frontal upslope flow and appears to have a decent chance of storms developing as well. Things have been kind of quiet around here lately so I thought I'd post a thread to try and stir up some interest for those chasers who might have their eye on this developing scenario.
-
While Stormtrack has discontinued its hosting of SpotterNetwork support on the forums, keep in mind that support for SpotterNetwork issues is available by emailing [email protected].
07/18/07 FCST: WY / NE / SD / IA / WI / IL / ...
- Thread starter Mark Blue
- Start date
Edward Ballou
EF4
Moderator Note: please update the target area to include SD/IA/IL/OH & any others.
There's an impressive boundary or zone of development between Yankton and Sioux City. The skew-T's are very much at different ends of the spectrum. Yankton only has a CAPE of about 467 while Sioux City is at 5000+? Of course we can't make our forecasts on cape alone! Td's look to be in the high 70's and darn near approaching 80 in NW Iowa. I believe this is our best area for the day. Another supporting fact is the LCL's in the area seem to make a nice low pocket centered on Sioux Falls. I am worried about CIN and low level shear. There's a nice pocket of these parameters extending NE from Rose,NE area all the way up to Pipestone, MN. I would look for things coming off of this area and heading east. A decent setup - I hope everything doesn't just go boom at once. A definite need to be early to this event as it will go HP and then MCS pretty quick. I guess the last thing that worries me is the cloud deck. It's not as present down there as it is in Brookings.
Not sure if I will head out yet - it is very tempting. NWS seems to be downplaying the tornado threat and favoring lots of rain and hail.
There's an impressive boundary or zone of development between Yankton and Sioux City. The skew-T's are very much at different ends of the spectrum. Yankton only has a CAPE of about 467 while Sioux City is at 5000+? Of course we can't make our forecasts on cape alone! Td's look to be in the high 70's and darn near approaching 80 in NW Iowa. I believe this is our best area for the day. Another supporting fact is the LCL's in the area seem to make a nice low pocket centered on Sioux Falls. I am worried about CIN and low level shear. There's a nice pocket of these parameters extending NE from Rose,NE area all the way up to Pipestone, MN. I would look for things coming off of this area and heading east. A decent setup - I hope everything doesn't just go boom at once. A definite need to be early to this event as it will go HP and then MCS pretty quick. I guess the last thing that worries me is the cloud deck. It's not as present down there as it is in Brookings.
Not sure if I will head out yet - it is very tempting. NWS seems to be downplaying the tornado threat and favoring lots of rain and hail.
