5/8/04 FCST - KS, NE, IA

[Mike Hollingshead]

Yes, I've noticed that in sw IA near the Red Oak area. There was alot of standing water in that area when I noticed those summers. I can't say I've noticed Denison doing it, but it's possible. Ths front looks like it may be slowly dropping south!!!!!!! Not the right direction, but since either way it's so slow I'm not certain it matters at this point. I do think Tekamah ene will be the first place to "go"....hopefully really early.

 

[Ryan Pfannkuch]

The state of IA has some serious issues with dewpoint calibration at several AWOS stations and has for some time now. You definitely have to take a lot of the AWOS readings with a serious grain of salt and look at surrounding stations to see if a reading may be overdone.

 

[Mike Peregrine]

Originally posted by Joel Wright
There are a few observation sites out in IA that usually report bogusly high readings every summer. I believe Denison is one of them, I know Shenendoah is one. Sometimes their dewpoint is reported as high as the upper 80's while all other sites are in the 70's.

Shenandoah over-blows dewpoint and temperature both ... it's done it for a long time now and I'm not sure why that equipment hasn't been calibrated (or else there is some reason that the moisture and temperature tend to collect around the station ... who knows). St. Joseph also tends to be different enough from the surrounding stations to make it pretty suspicious ...

Still trying to decide what to do ... if I go for it I need to leave really soon here - - -

 

[Mike Hollingshead]

http://www.rap.ucar.edu/weather/model/disp...&hours=hr09hr12

That shows the new run(15z) and the old run(12z) for the same time frame. Nice change in the new run. LOL till it updated! I'm not thinking.....

http://www.rap.ucar.edu/weather/model/disp...&hours=hr02hr03

I was thinking how the earlier hours update more frequently then the 6,9, and 12hr. Hmmmm though. RUC pretty much thinking by 2 pm?

 

[Mike Peregrine]

Would be nice though if it would hold off to 21z as helicity improves quite a bit:

http://beta.wxcaster.com/models/eta/centra...KM_SRH_09HR.gif

llvl shear:

http://beta.wxcaster.com/models/eta/centra..._SHEAR_09HR.gif

The surface wind just does not veer with enough punch to hold interest ...

http://beta.wxcaster.com/models/eta/centra...VECTOR_09HR.gif

It is reminding me of yesterday, though there may be a better chance of initiation. I'm afraid though that anything that does initiate will be doing so in an environment that will not sustain surface-based rotating convection for long.

0-3 SRH is on the low end of marginal:

http://beta.wxcaster.com/models/eta/centra...KM_SRH_09HR.gif

SFC based CAPE nears 3000 along the boundary, provided that it does extend northward to the IA/SD/NE state lines:

http://beta.wxcaster.com/models/eta/centra...S_CAPE_09HR.gif

LCLs and LFC values seem to indicate high convection that will be heavy on precip:

http://beta.wxcaster.com/models/eta/centra...ML_LCL_09HR.gif

http://beta.wxcaster.com/models/eta/centra...ML_LFC_09HR.gif

Think I'm sitting it out AGAIN. Man this is dull ... where are the serious fireworks peeps??? We NEED a big 'ol trough and a negative tilt soon or May is going to SUCK. (Climatology does show some better possibility for the coming week, though - for central and southern too.)

 

[Austin Ivey]

I think we're all going to have to wait for mid-late next week Mike. I hope so, since I have off of work next week!

 

[Fritz Kruse]

Tornado Threat Northern Iowa

ETA and New RUC show at least 30 knots at 500mb or more along the warm front in n. Iowa. Also very good instability with over 3000 J/kg. My favorite chases are with about 50 knots at 500mb and 3000 J/kg and seems to be a great balance of shear and instability for tornadic thunderstorms.

This case, we need any storms that form along the warm front to slow down and move about 10 knots, or turn more right to get around 20 knots of mid level storm relative shear. If this happens a few tornados would be possible later this afternoon with stronger mesocylones. Now if they really hail load and move very slowly and along the warm front then watch out. The mid level direction from the west should keep the storms along the front.

 

[Mike Hollingshead]

I agree Fritz.

http://www.spc.ncep.noaa.gov/exper/mesoana...sis/s2/muli.gif

http://www.spc.ncep.noaa.gov/exper/mesoana...sis/s2/sbcp.gif

Getting just a touch unstable along the front in IA and the cap is weakening.

http://www.spc.ncep.noaa.gov/exper/mesoana...sis/s2/mcon.gif

Nice convergence and the IA end of the front is still further north under better mid-upper flow. MikeP I wouldn't blow this off just yet.

 

[Mike Hollingshead]

Looks like best convergence just north of Columbus now on sfc. And satellite showing new cu there now. Liking the NE side much more then the IA side now. SFC winds more backed here and not veering like in IA.

 

[Jared Mysko]

System moving in from Montana at this time...intercept vehicle packed and gased up... departing in 5 minutes

Target: Estevan SK

ETA: 8pm

Jared Mysko

 

[Mike Hollingshead]

http://www.spc.noaa.gov/products/md/md0593.html

For those that don't know where to look.

 

[Fritz Kruse]

Storm Lake to Ft. Dodge Iowa - Watch Out !!

Nice Theta-e axis showing into west central Iowa, 30 to 35kt at 500mb, Mu CAPE approaching 3000 J/kg along warm front and over 4000 J/kg south...Jeez!!

Look for explosive development, and with such High CAPE, this can make up for lack of good storm relative shear; probably next few hours. I still think a Tornado threat looks good along the warm front so would look for a RED BOX shortly. Looks like a wave moving into nw Iowa now.

SPC will probably issue a BLUE BOX, then after a few hooks develop change it to a RED BOX.

 

[Tim Stoecklein]

Is Amos still hanging out near Des Moines? Or was he never there? That seems like a good target right now to me. I believe we could see it start up in the next two hours. Hope I didn't just jinx it... :wink:

 

[Mike Hollingshead]

Stuff popping near Des Moines now. Last I heard Amos was in Norfork NE.

http://kamala.cod.edu/spc/WW163.20.html

Stuff near Des Moines appears to actually be south of the boundary?

 

[JR Hehnly]

Lovely, I just got back to Oklahoma, flew out of Des Moines this morning. Good luck up there, guys!