6/4 FCST: Central Plains et al.

[Jeff Snyder]

Per request, thread being started for forecast discussion... Looks like some severe possible as Gulf moisture makes a return to the central plains...

 

[Mike Hollingshead]

Thanks Jeff. Friday looks like one of those nc NE summer flying eagle days to me right now. Hopes have gone to high per 0z eta. I don't have a lot of thoughts to offer other then there is some fairly nice shear up there atop healthy cape. Low level flow could be considered rather weak, but it seems sometimes these southward moving sups don't need impressive low level shear to spit out tors. They can be very fun to chase as they continually backbuild and drop south to even ssw. 850/700 temps rather stout, but perhaps that is a good thing. I think I'm game to find out. Get one up and she should go for some time. Target as of Tues night Valentine Nebraska. Thoughts?

Mike

 

[John Sickels]

Check out HPC map for Friday:

http://www.hpc.ncep.noaa.gov/medr/9jh.gif

SPC also talking about "active" day over the central plains on Friday.

 

[Mike Hollingshead]

Nevermind, not as excited now. 12 and 18z eta took away half the 500mb flow leaving us with 20 whopping knots. Might still be something interesting though who knows.

 

[Chauncy Schultz]

I'm not entirely discounting Friday being an interesting day in the severe weather department in parts of the northern or even central plains. Truth be told, I have not looked too closely at the areas discussed previously discussed here, i.e. the NE area, but I have had a chance to look at some data further north, in the Dakotas.

The upper level ridge located across the West will continue to slowly amplify and build north and eastward...with upper level northwest flow to persist across the center of the nation. Embedded in this flow will certainly be some shortwaves which are currently hard to pick out considering the fact that the GFS continues to suffer from convective feedback which is adversely affecting not only it's qpf signal, but also its vorticity fields, a prime mechanism for locating the shortwaves in the flow. Now that we're getting closer in time, though, the ETA agrees that some waves will be on their way through the northern plains during peak heating...but the 2 models disagree on timing of the surface low/trough to press through the Dakotas, with the GFS the slower model. The two also disagree to some extent to where the nose of the low level jet will be located by 00z.

One thing is fairly certain....that being that instability will not be that hard to come by. The 12z and 18z ETA runs both project upwards of 3000 J/KG of SBCAPE extending as far north as south central ND during the day…not surprising considering the abundant low level moisture that won’t have a problem getting into the region. Capping will be of some concern ...so 1)convection may be strongly tied to surface convergence and be located further north...again, into the Dakotas and 2)the convection could be of the overnight MCS variety. The wind profile will certainly be supportive of supercells if surface based updrafts were to form during the aft/eve.... especially since 500mb flow is still projected to be upwards of 40kts further north....but I agree that weaker low level wind fields may preclude a more significant tornado risk.

In essence, then, there remains some risk of severe weather on Friday....especially from Nebraska on north. We'll have to keep tabs on things.

 

[Jared Mysko]

SPC just made the slight risk line go right along the Canadian border so I guess I can relax now, lol. Looks a bit silly to me since I am quite sure that it will extend into the Canadian Prairies. I don't expect that there will be anything major but I'm quite sure Friday will be a good day for storms in southern Sask. I'm still gonna save up some gas money for a real chase which may be soon.

Cheers,

Jared

 

[Mike Hollingshead]

Jared.... just get ready for Sunday up there..lol, wow. Someone wants to start a Sunday thread that'd be great.

http://weather.cod.edu/forecast/ETA/offeta..._3km_hel_84.gif

Sunday has a smidge of potential in the western Dakotas.

 

[Jared Mysko]

Yup, I can't wait to see the next ETA forecast runs for Monday in Manitoba. Looks like a two day chase for me. Monday may be the main day for action if the 12z forecasts are any indication.