Chase Case #2

[Verne Carlson]

okay I'm going to project the surface features and 500 mb winds through the day an say Kearney, NE for an initial target. Normally on the morning of I'd be checking the RUC for 18 - 0z projections but I'll do this by mental note to move things about a 1/2 state east from the morning.

 

[Chris Lott]

Not if we're assuming this is 'chase season'. You're correct, this time of year (winter) 6am = 12z; but in spring and summer 7am = 12z.

You guys are both correct. I was stuck in the current "winter" scenario, not even thinking about daylight savings time. Anyway, I'm ready for the 18Z update, still holding tight in Ponca City.

 

[Tim Segraves]

I'm going to start out in Phillipsburg, KS this early. I like the way southern NE is looking but don't want to commit this early since there is almost no CAPE so I'm taking a slightly more southerly position for now. I hope to see some more moisture and instability move up here in the next update.

 

[John Farley]

Since the data are for early morning (not a forecast of later), the instability is well to the east or southeast, and shear will be localized along the warm front, I'm going for the more eastern target, probably in NE Kansas. Less of a drive for me, too. So I will start out in Lawrence, KS.

 

[Dick McGowan]

Just analyzing the 12z maps, there seems to be dry air contaminating Kansas/Nebraska regions at 850 out of the SW...with a warm temp at 24 C, definitely a temperature advection going on, which may cap the warm front later in the day (or they may never be able to become surface based). I see rich, deep BL moisture heading up from Mexico, out of the straight South at 850 as well, with a rich, 16 dewpoint crossing the border. It should make it up to W. Texas and into the panhandles by 0z, so I'll start out in San Angelo, Texas and hope the dryline really starts to punch through by 21-22z to my west. Near El Paso, it's 63/16 with sfc winds at 15 knots from the W/SW...I like my spot for now and will be eager to see the 18z data...as I am ready to head north OR south if needed. I think the mid and upper level support should continue to increase throughout the day as the system out on the West Coast digs further south (I hope!).

 

[Brian Stertz]

I am going to start out in Hastings NE on the warm front and edge of the cap. Dryline looks tempting but am leary of the likelihood that LCL's may be pretty high. Some good moisture pooling is likely to occur on the boundary along the I-80 corridor. I would expect winds to steadily back at 850mb by later in the day. Should have a triple point nearby by late afternoon/evening and some pretty good directional shear. I'll set up camp and wait for more data and hopefully a good RUC panel.

 

[Dennis Sherrod]

Well, I am not 100% satisfied with my decision yet, but I will start off initially in Emporia, KS.

 

[Doug Mitchell]

I'm going to start the day in McCook, NE

 

[David Wolfson]

The low up near Julesburg and the front north of the KS/NE border is hard to resist, but... the upper pattern seems to be fixing to eject PVA off the mountains into the Clayton-Boise City-Springfield area. There's streamwise divergence according to my eyes with almost a split flow trying to develop at the higher levels. I think afternoon will find the Julesburg low dropping south to extreme southwest KS with some frontal development on something like a Syracuse - Wichita line. The DDC sounding isn't much, but the deeper moisture and temps should look pretty good south and east from there by evening.

So I'm starting out in... Coldwater, KS.

 

[Simon Brewer]

Hardcore cold air advection at 700mb over Southern Cal makes me think that mid-level closed-low will dig a little more throughout the day and not reach the plains, so I'm thinking there will be no height falls or maybe even height rises south of I-70 at 500mb as that ridge builds a little more in advance of the slow-moving mid-level closed-low. The trough propagating across Manitoba should reinforce the cold/cool air north of the warm front/stationary over southern Nebraska. Lee troughing over the High Central Plains and low-level pressure falls over, most likely, Colorado in advance of the slow moving mid-level closed-low should continue the moisture feed into northern Kansas and southern Nebraska...

Basically, I think it looks best to play the stationary boundary/warm front in southern Nebraska at the intersection of the dryline.. question is: how far east does the dryline mix? I'm gonna sit in Hastings, NE and wait for more data...

Simon

 

[Dennis Dennison]

I am going to sit in Alliance, Nebraska. My gut says something is possible in South Dakota too, but my confidence is only 50/50. I think this position will allow me to move quickly as I get more reports.
So Sam, I am with you to an extent.

 

[Bob Hartig]

Just analyzing the 12z maps, there seems to be dry air contaminating Kansas/Nebraska regions at 850 out of the SW...

Dick, where are you getting this from? I haven't been able to make out dews on this 850 chart. No problems with the Weather Graphics charts, but I'm having a tough time with this one.

I still have a hunch that moisture won't be problem around NE/NC Kansas. My personal tendency has been to underestimate just how far north deep moisture will reach between 12z and firing time. Looking forward to the 18z run to find out whether I guessed right or bombed.

 

[Chris Frost]

Well, I'm probably gonna get on I-70 west out of Lawrence for HILL CITY. My thinking is play the dryline close to the low, however, it's still early in the the day for an adjustment

That dryline bulge along the Red River is interesting but the winds aren't as good

 

[Darren Addy]

I'm posting this before reading any of the comments (as an exercise) because this is something I really need to get much better at and hopefully these exercises and the surrounding discussion will help.

I'm trying to think of where this set up will be 8 hours from now and thinking that the low (and associated dryline) should be sliding east. I don't want to be west of the dryline and I want to be south of the cold front. I think I'd select Russell, KS on I70 as my starting point and hope that the decent road options from there would put me in striking distance of the action as further data comes in.

 

[Dick McGowan]

Dick, where are you getting this from? I haven't been able to make out dews on this 850 chart. No problems with the Weather Graphics charts, but I'm having a tough time with this one.

I still have a hunch that moisture won't be problem around NE/NC Kansas. My personal tendency has been to underestimate just how far north deep moisture will reach between 12z and firing time. Looking forward to the 18z run to find out whether I guessed right or bombed.

http://img132.imageshack.us/img132/42/12z850ww3.gif The red is temperature and the green are dewpoints. You can see the deeper moisture's contour lines on the US/Mexico border down there pushing northward. It's still 12z and I never wake up this early anyways to analyze anyways ! But at 7 a.m. and 24 degrees C at 850 mb in SW KS, the air there is most likely capped just above the surface...and it looks like it's advecting northward with the front. The 850 mb dewpoints are shallow right now up in KS....and I'm not a huge fan of SW 850's, but that's not to say things won't change by 18z. I'm most likely heading north at 18z into the Texas Panhandle...