4/17/04 FCST: MIDWEST/GREAT LAKES

[ckbehnke]

I think the depth of moisture could be alot worse. Looking at 12Z sounding for DVN, it's not that bad. DVN is the more favorable sounding I believe due to it's relation to the frontal boundary. I am more worried about lack of favorable Jet structure up to 6Z, and no signs of a significant shortwave to help in synoptic scale ascent. I think it will be a matter of timing/hoping something discrete can go before the arrival of the LLJ

 

[Mike Peregrine]

Just posting the links to the 9hr RUC maps for this afternoon in IA for those who are interested while we're waiting for the 6hr update.

CAPE/CINH - http://www.rap.ucar.edu/weather/model/ruc0...hr_sfc_cape.gif - indicates instability along the WF in the 2000 range, along with a gap in inhibition.

Convergence - http://www.rap.ucar.edu/weather/model/ruc0...hr_sfc_mcli.gif - looks inviting along the boundary - there is a plume that extends from TX up across the dryline in KS - but doesn't appear deep enough to be hopeful about sfc based convection as of this particular run.

Helicities in the 500-600 range (another concern for any still considering the DL, although the panhandle is decent.) http://www.rap.ucar.edu/weather/model/ruc0...hr_sfc_sreh.gif

Vertical motion/mixing panels - http://www.rap.ucar.edu/weather/model/ruc0...9hr_925_mxr.gif - again, depth looks good in vicinity of boundary.

Looks to me like Iowa holds the ticket at this point ... won't be making the drive today, though - got the car in shape and it's just all tricked out - can't wait to use it now. All the best for those heading out -

 

[Mike Peregrine]

By the way, Jon Davies has a really good explanation for cap estimation according to month:

http://members.cox.net/jondavies1/700mbTca...mbTcapguide.gif

and explanation of 700mb temperature guidelines here:

http://members.cox.net/jondavies1/700mbTca...p/700mbTcap.htm

Thought those are helpful for amateurs like myself -

 

[Michael Shively]

Just took a look at the radar from KDMX at 0006Z....looks to be some convection starting.....maybe....very weak returns, but are consistent with t-storm development....look for a watch to be issued shortly,as MD stated earlier....so far, no EXPLOSIVE development however

 

[Michael Shively]

OK....NOW there is EXPLOSIVE development i think somebody needs to start a now thread on these storms in NC IA

 

[rdale]

Awaiting the NOW thread - here's the cell along the IA/MN line:

ftp://radioweather.us/dmx0055.gif