High Plains Drifter

disclaimer:  "The meteorological views/forecast thinking expressed are those solely of the author of this blog
and do not necessarily represent those of official National Weather Service forecast products,
therefore read and enjoy at your own risk and edification!"

February 27, 2011

Chase Account: 2011 February 27 (Sub-severe storms)

Filed under: Chase Accounts,Storm Chasing — Mike U @ 10:00 pm

First storm chase of 2011 — sub-severe storms from northern Woods County, OK into Barber County, KS

Sunday, 2/27 was my only day off work during a long stretch of day shifts, and I was swaying back and forth on deciding whether to dedicate the day to a storm chase or not.  When I went to bed Saturday Night, I was not anticipating chasing, but was willing to re-consider if things shifted farther to the west.  Well, the RUC and HRRR models early Sunday morning were shifting the surface moisture and convergence farther west into northwestern Oklahoma.  Also, the remnant cold airmass had lingered around a bit farther south deeper into Kansas, and it appeared that the warm front would not lift back north into Kansas at the surface.  The mid level jet streak was also poised to come across West Texas a little bit later and perhaps a bit farther south, so all this led to the possibility of a focus farther west for mid-afternoon strong to severe storms. I decided to target far Northwest Oklahoma based on agreement between the RUC and HRRR model runs, which seemed to be fitting observations and my conceptual model of how the wind, temperature, and moisture field would evolve.  I expected a narrow tongue of mid-upper 50s dewpoint air to make it back to Harper County, OK.

The moisture did make it back into far Northwest Oklahoma by early afternoon, but the deep and extremely intense westerly momentum across West Texas did not allow the moisture to remain back west over the far western counties of western Oklahoma.  South-southwest winds at the surface were shunting the 50s dewpoints a county or so farther east, and the corridor of southeast winds were not really materializing in the Gage/Laverne areas.  I was expecting (and hoping) the initial towers to develop near Lipscomb, TX and then move across the Laverne area and eventually Buffalo, OK and points northeast from there.  What ended up happening was towering cumulus development occurring farther south and a bit east in the well-mixed air.  The initial group of tower cumulus developed from Arnett to Cheyenne, basically at the longitude I was already at.  I needed to adjust east.  So I did just that, and when I reached Buffalo there was an elongated cluster of poorly organized bases to my south-southwest.  I continued east to near Camp Houston and watched that area develop a little bit more, and radar indicated taller growth into the mid-levels.  I was basically right along the front, but the winds just north of the front were becoming southeasterly up to the KS border.  I liked this.  I thought that if this storm could form rapidly, it may just take advantage of this mesoscale sweet spot from northern Woods County into southern Barber County, KS.  I took a gamble with this first development, seeing as the second area of cumulus growth and echo on radar was quite a ways to the south still.  (this southern storm near Vici, OK ultimately developed into the long-lived supercell and “storm of the day”).  I figured, “bird in hand”, so I’ll play with this thing closer to me and already an established storm.

I went north on N2230 Rd a few miles east of Camp Houston and followed it north into Kansas.  Of course, by the time I reached the storm near the KS border, it was beginning to fall apart.  It still maintained some structure as it neared Aetna, but it was just so small.  I then opted to go east on Hackberry road (instead of continuing north on Aetna Rd. to Hwy 160).  The storm continued to move quickly northeast at around 40 mph or so, and as this was going on, the storm to the south, about 60 miles south-southeast of me was beginning to ramp up quite a bit.  I continued to observe updraft pulses with the storm just north of me, but the contrast was poor.  I came across some roaming bison on this open range that Hackberry Road meanders through.  That was pretty cool.  I was out of position with the southern storm farther away, and on a day like this when storms were moving 40-55mph, early decisions you make in the chase will largely impact what follows because there is no room for error.  I committed too soon on this chase on a storm that was too far northwest with respect to the warm/moist sector.  The storm to the south-southeast of me had much more real-estate of CAPE to work with, but the storm was fighting all this intense westerly component low level flow.  That kind of bothered me and was one reason why I second guessed the storm.  The southern storm ultimately became a very nice looking supercell on radar and an eventual tornado producer that a number of storm chasers saw.  Of course, the way I chase, I seek “the road less traveled”, and again it bit me.  Nevertheless, it was great to get out and dust off the cob webs (including my forecasting skills!) and kick off the 2011 storm chasing season.  Photos from the chase below:

Heading home from chase

Filed under: chase mode updates — Mike U @ 5:48 pm

Saw some marginal storm structure in the red hills along the ok ks border. Highlight of the chase was coming across a few bison on the open range west of Hardtner along Hackberry Road over open range. Contemplated going after northern OK storm about 50 miles southeast of me but thought the potential reward was low. A few photos on my blog later tonight

chase update 2/27 1:25pm

Filed under: chase mode updates — Mike U @ 2:27 pm

First storm chase of 2011. I am sitting just north of Laverne
Oklahoma where it is a balmy 76 degrees. Unbelievable after the past
couple of days. I am right along the front in extreme northwest OK.
There are some upper 50s dewpoints within throwing distance of my
location. Woodward is sitting at 57F dewpoint at 1pm. I think the
winds will continue to back to the southeast from Gage to Woodward
through the afternoon. I am interested in the RUC and the HRRR both
showing a small area of convection developing at the nose of the 1500+
J/kg surface-based CAPE around 22z or so in this area. There is
already convection developing in south-central KS but it’s all in the
low stratus for the most part. Nice heating going on out here on the
western Plains. I’ll be hanging out here unless something pulls me in
another direction.

Test post

Filed under: chase mode updates — Mike U @ 11:29 am

Seeing if this thing still works!

February 9, 2011

Southwest Kansas Snow Event 2011 Feb 8 [6]

Filed under: 2011 Feb 8 — Mike U @ 12:51 am

7.8″ total snowfall (10:30pm) at my house 5 N Dodge City. As of the time of this blog post, at around 11:40pm CST, light snow continued, but it was beginning to wind down (see radar figure below).  We have been getting roughly 2 to 5 tenths of an inch of snow, per radar analysis, since the last time I measured the snow.  I went out and measured again, but compaction has set in from the prolonged strong northeast winds, so simply measuring snow depths doesn’t really mean the same thing as “snowfall”.  At 6:25pm, I called it 6.3″, so another 1.5″ in that four hour time span is reasonable.  It’s going to be fun photographing these drifts in the morning!  In the meantime, I have attached some nighttime images of some of the drifting between my house and the neighbor’s house on my south side.  The northeast winds caused fairly substantial drifting in through there.










February 8, 2011

Southwest Kansas Snow Event 2011 Feb 8 [5]

Filed under: 2011 Feb 8 — Mike U @ 5:16 pm

Still moderate/occasional heavy snow as of 4:10pm. Around 5.5″ was what I was calling the total snowfall here at my house 5 N Dodge City as of 3:30pm.  The drifting is so substantial that it is nearly impossible to find a representative area now.  There is a lot of subjectivity to measuring snow in this wind.  In the longer duration gusts, it’s a near white-out condition looking out my back window.  I drove through town about an hour ago and visibility in town was extremely low, no more than a block or two at the most.  Attached to this post are a few images I shot from along Wyatt Earp during heavy snow and blowing snow:

110208_15523684 110208_15535522 110208_15555414 110208_15564932

Southwest Kansas Snow Event 2011 Feb 8 [4]

Filed under: 2011 Feb 8 — Mike U @ 2:18 pm

3.0″ snow 5 N Dodge City and numerous drifts to 10-15″. Heavy snow is in progress at my house north of Dodge.  It was difficult to measure the snow, but as of 12:50pm, I came up with what I thought was a fairly representative 3.0″ snow depth.  There were a lot of 1″ depth spots, but there were also a lot of 6-9″+ drifts adjacent to the psuedo bare areas.  The drifting over the ditch at the front of my front yard is approaching 25″ now.  I’ve attached a couple photographs to this post to illustrate the substantially reduced visibility in heavy snow and blowing snow.





Southwest Kansas Snow Event 2011 Feb 8 [3]

Filed under: 2011 Feb 8 — Mike U @ 11:22 am

0.50″ QPF. The 12z NAM, 14z RUC, and 13z HRRR all generate a half-inch of liquid equivalent precipitation.  18:1 SLR would be 9″ of snowfall.  Stronger frontogenesis for a longer period of time is now expected across Southwest Kansas, especially between the Arkansas River and the Oklahoma border through this evening.  Moderate snow is occurring now at my house with the northeast wind around 25 mph, gusting occasionally to 35 mph.  Heavy snow is now developing to the northwest of Dodge City, and this will overspread Dodge by Noon.  My own personal snowfall forecast is now 6 to 9″ for Dodge City.  The office just upgraded Dodge to a Winter Storm Warning now for widespread 4-8″.


Southwest Kansas Snow Event 2011 Feb 8 [2]

Filed under: 2011 Feb 8 — Mike U @ 10:12 am

High snow-to-liquid ratios (SLR) being observed. Overnight, light to moderate snow accumulated 2 to 5 inches across northwest and north-central Kansas, southwest and south-central Nebraska.  SLR of 18-25:1 are being reported with several 4 and 5 inch snow amounts up north with only about two-tenths of an inch of melted snow.  Given the wind and the very “fluffy” nature of the snow, rain gauge catch is a big problem.  Accuracy of SLR during these times are very poor… but that being said, I think at least 18 (if not low 20s) to 1″ liquid makes sense given the very deep dendritic growth zone layer of a couple hundred millibars.  It’s snowing lightly as of 8:45am in Dodge City with what appears to be perhaps a tenth or two of accumulation.


The 12z RUC continues to be quite impressive with the simulated radar reflectivity and 700mb frontogenesis through the day across Southwest Kansas.  I think we’ll easily see 5″ of snow in Dodge City, if not more, based on a high SLR from observations up north.  New Local Storm Report came in at 8:37am of 4-6″ of snow from a spotter south of Collyer in Trego County (that’s in the Dodge City NWS forecast area).  Wow.

12z RUC graphics follow.  Last image is the RUC accumulated snowfall through Midnight tonight, showing 5″ in Dodge City:

Southwest Kansas Snow Event 2011 Feb 8 [1]

Filed under: 2011 Feb 8 — Mike U @ 2:58 am

Finally, some decent snow for Dodge City this season.  About time. It looks like a 3 to 5″ snow event will affect Dodge City, KS and surrounding areas.  The 08/00z runs of the NAM gives Dodge City about 0.55″ of QPF while the GFS and Canadian GEM offer around 0.30 to 0.40″ or so.  What is interesting about this storm is that the thermodynamics in the lower-mid troposphere will be characterized by a very deep layer within the dendritic growth zone (-12 to -18°C).  Saturation and lift through this deep growth zone layer will likely support liquid-to-snow ratios of 1:15 if not higher… to 1:18 or so.  Therefore, 0.40″ QPF would yield 6 or 7 inches of snow.  The official forecast for Dodge City is for 3-6″:

Tuesday: Snow likely before 9am, then snow and areas of blowing snow after 9am. High near 18. Wind chill values as low as -1. Breezy, with a east northeast wind between 22 and 24 mph. Chance of precipitation is 100%. New snow accumulation of 2 to 4 inches possible.

Tuesday Night: Snow and areas of blowing snow before 2am, then snow likely and areas of blowing snow between 2am and 5am, then areas of blowing snow and a chance of snow after 5am. Low around 0. Wind chill values as low as -19. Blustery, with a north northwest wind between 15 and 22 mph. Chance of precipitation is 100%. New snow accumulation of 1 to 2 inches possible.

Here is a surface map as of 06z (Midnight CST) showing the approaching arctic airmass ahead of the approaching upper low.  Snow was already underway across western Nebraska and much of northeastern Colorado:


The following series of images show the 05z run of the 20km RUC model of 700mb Wind/Temperature/Heights along with Composite Reflectivity every three hours from 09z to 21z Tuesday.  The last image is the RUC forecast snowfall accumulation total through 21z:

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