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 28, 2007

Interesting night back home…

Filed under: General Weather & Forecasting — Mike U @ 11:40 pm

The first severe weather event of 2007 in the Kansas City area was a pretty active one…mainly south of the metro though.  I was watching a little bit of the long-lived tornadic supercell activity unfold in the Iola, KS area while at work this evening.  Here is a StormLab graphic showing the storm reports over east central KS and west central MO:

It’s not even March yet!


February 27, 2007

Quivira short-trip on Feb 26th

Filed under: Photography — Mike U @ 10:29 am

A sandhill crane displaying out in the field just north of Quivira NWR80,000 Sandhill Cranes.  It was one of my days off Monday, and I decided to head out to Quivira to do some photography… since I haven’t done any shooting since the 2nd of January.  With it being late February, I was hoping to photograph some Sandhill Cranes that are staying on the refuge temporarily on their journey north.  While the large majority of these cranes stay along the Platte River about 175 miles north of here, there are a number of family groups that use Quivira.  I think some stop at Quivira shortly anyway before continuing to the Platte.  When I arrived Monday around midday I was greeted to a large conglomeration of cranes on a farm field roughly 3 miles north of the Big Salt Marsh. I photographed from here for about an hour to hour and a half.  In the late afternoon, I drove through the rest of the refuge to try and find any other action, but I didn’t find much — although I did spot 5 Tundra Swans.  I was anticipating the cranes flying back to the Big Salt Marsh just prior to sunset, but that wasn’t happening — they were all still in that one location, frolicking in two different fields separated by an east-west farm road.  I was fortunate enough to have a big row of trees to help use as a blind allowing me to get a bit closer to the cranes than I otherwise would.  Anyway, I stayed here until sunset to photograph them as they were not in any hurry to fly back to the marsh.  I ran into a local photographer and volunteer at Quivira NWR, and we struck up a conversation for a bit… and he told me that the large percentage of these cranes actually stayed the whole winter!  I found that hard to believe given how cold it got during January.  Really interesting.  I wonder how much last winter’s warmth had to do with that, and they figured it would be just as warm this winter and decided to stay after migrating down in late October.

February 25, 2007

Central Plains Winter Storm Feb 23-24 [9]

Filed under: Feb 23-24, 2007,General Weather & Forecasting — Mike U @ 10:59 am

. . . Peak wind gust reports across eastern Colorado and western Kansas on the 24th . . .

Location Peak
Gust (mph)
Cheyenne Wells, CO 82 Storm spotter measured
Hays, KS 75 AWOS
La Junta, CO 74 ASOS
Elkhart, KS 72 AMOS
Hill City, KS 69 ASOS
Springfield, CO 69 ASOS
Akron, CO 68 ASOS
Limon, CO 68 ASOS
Scott City, KS 68 AWOS
Hugoton, KS 67 AWOS
Ulysses, KS 67 AWOS
Johnson, KS 66 AWOS
Garden City, KS 66* ASOS
Dodge City, KS 64 ASOS
Sheridan Lake, CO 64 Storm spotter measured
Lamar, CO 64 ASOS
Hoxie, KS 63 Storm spotter measured
Liberal, KS 63 AWOS
Leoti, KS 62 Mesonet
Burlington, CO 62 ASOS

* Garden City observations were manually taken for 3 hours during the
wind storm and gusts were not reported, so peak wind could have been
higher than 66 mph.

. . . Blizzard criteria met at automated weather observation stations over the central High Plains . . .

of Automated Surface Observation
of Blizzard (Hrs)
Limon, CO 9.5 1020-1955
Akron, CO 7 1233-1925
Ainsworth, NE 7 1711-0011
Thedford, NE 6 1411-2011
North Platte, NE 5.75 1418-2004
Goodland, KS 4.25 1657-2116
Lamar, CO 3.25 1527-1841
La Junta, CO 3 1446-1753
Burlington, CO 3 1253-155

Note of interest:
  Immediately west of the low in western
central Kansas, blizzard conditions were reported from Hays to Rush
Center to Larned during the late afternoon hours, however, the band of
snow was rather narrow, and conditions lasted less than 3 hours, not
officially meeting blizzard criteria, but came close in some areas.

Addendum:  I was wrong, I found out that this corridor from Hays to Rush Center to Larned did indeed meet blizzard criteria after looking through our logs at work.  Several reports of 3 to 4 hours of less than 1/4 mile visibility in snow and blowing snow to go along with the 50+ mph wind gusts. 

February 24, 2007

Central Plains Winter Storm Feb 23-24 [8]

Filed under: Feb 23-24, 2007,General Weather & Forecasting — Mike U @ 4:06 pm

Tornado damage southwest of Dodge City on the 23rd.  I came in to work this morning to check my e-mail and the latest on the storm since my cable/internet are out at home (Ugh!)… then after receiving a report of damage from last night’s tornado in southwestern Ford County, our WCM came in and I went on a damage survey with the WCM at our office, and we found a decent track through southwestern and west-central Ford County…with a smaller track to the southwest of it.  Damage was not major with the primary indications of tornado being flipped center pivot irrigation systems.  This storm was extremely rare being in February and at night as well.  Dodge City was in the cross-hairs of this storm between 10:45 and 11:00pm last night but the storm circulation diminished quickly and lost supercell characteristics.  While out on the survey, the northwest winds were incredible…

55 to 65 mph wind gusts behind the low!  Some of the surface obs in western KS and eastern CO are awesome today.  Many 33040G55KT surface wind observations (northwest at 40 knots gusting to 55 knots).  Even here in Dodge City we have peaked at 55 knots at 3:00pm, which caused commercial power interruption at the office.  We’re missing out on the blizzard conditions though as it’s not snowing in Dodge City.  Farther northwest in western Nebraska, far western Kansas, eastern Colorado… blizzard conditions are incredible with the winds as strong as they are.

February 23, 2007

Central Plains Winter Storm Feb 23-24 [7]

Filed under: Feb 23-24, 2007,General Weather & Forecasting — Mike U @ 7:31 pm

"Panhandle Magic" begins the Great Plains tornado season!  At least a handful of chasers witnessed and documented the first Plains tornado of 2007 as a few supercells developed over the eastern Texas Panhandle early this evening.  Below is a radar image with a few of the storm report icons from around that time.  Apparently the tornado north of McLean was the one that was observed by several chasers… Not much has happened yet in Southwest Kansas but I think that’s about to change per the water vapor loop… tremendous upward motion is about to impinge on Southwest Kansas and dewpoints are rising into the lower to mid 50s just south of Dodge City.  More later…


Central Plains Winter Storm Feb 23-24 [6]

Filed under: Feb 23-24, 2007,General Weather & Forecasting — Mike U @ 4:42 pm

71 today… blizzard tomorrow!  High plains weather never ceases to amaze me.  We had a high of 71 degrees today in Dodge City… and at this very time tomorrow afternoon… it could very well be 30 degrees with northwest winds of 40 mph gusting to 55 mph and moderate to heavy snow with blizzard conditions.  The storm appears to be developing farther south just a bit…with the surface to 700mb lows developing just a little bit farther south.  Even the new 12z ECMWF shows a 500mb low center over the TX Panhandle now tomorrow morning.  I’m at home briefly, but expect to be called back into work in a couple hours when storms start developing.  A tornado watch and a blizzard warning are in effect over parts of the Dodge City NWS county warning area… how about that?  We’ll see what the real atmosphere can produce tonight and tomorrow… it looks really interesting. 

Central Plains Winter Storm Feb 23-24 [5]

Filed under: Feb 23-24, 2007,General Weather & Forecasting — Mike U @ 2:02 am

Western Kansas blizzard still on track.  All the models are still on track in developing the surface and mid level cyclone during the day Saturday as it moves across Kansas.  The kinematic and thermal fields are all quite impressive for fairly decent precipitation west of the low — suggesting a 9 to 12 hour duration blizzard over portions of western Kansas.  Below are a few NAM forecast charts I put together from the latest 00z model run:

850mb temperature prog shows air cold enough for snow diving south across western Kansas by midday Saturday 2/24.  700mb moisture is shown to wrap significantly around the system during the day

500mb low will be positioned near Pratt, KS per the NAM model with a very deep ~530dam minimum height.

For "wrap-around" precipitation around a powerful low, forecasters tend to look for a nose of warm, moist air in the mid levels from roughly 750 to 550mb.  Above is the 700mb temperature forecast showing an axis of warmer 700mb temps nosing back into the Hays-Wakeeney corridor just northwest of the 700mb low center.  The temperature gradient at 700mb between this warm nose aloft (more popularly called "trowal" by forecasters) and the axis of cold air to its immediate west over far northwestern Kansas and northeastern Colorado…will be a zone of enhanced precipitation.

Next update on this storm may not come until late tomorrow night as I may be pulling some overtime at work with severe weather ahead of this storm.

Central Plains Winter Storm Feb 23-24 [4]

Filed under: Feb 23-24, 2007,General Weather & Forecasting — Mike U @ 12:33 am

1st Severe Thunderstorm Outbreak on the Plains Tomorrow Night!  I have modified the dates on my blog of this event from the 24-25 to 23-24 as the system will be fairly quick moving…and the fact that Friday night the 23rd looks more and more like a potential nasty night for widespread severe thunderstorms along the dryline and advancing cold front aloft.  Take a look at the 00z NAM forecast from tonight’s run below.  It’s the 500mb Heights and 250mb Isotachs showing the upper level jet streaks.  This is a classic Great Plains severe weather pattern given adequate moisture in the warm sector:

Northern branch of polar jet and subtropical jet will spread into the southern Plains by late afternoon into the early evening on 2/23

Below is the 24hr NAM forecast of 850mb relative humidity and wind vector.  Ordinarily in the warm season, low stratus is not much of concern in the warm sector east of the dryline… however being so early in the season (late February) the northward transport of high moisture content will likely result in a lot of low clouds given the cooler lower troposphere this time of year.  All the models suggest this, and is a big concern for "chaseable" severe storms on the dryline tomorrow:

24hr NAM forecast valid 6pm CST 2/23 indicating low clouds likely east of the dryline the afternoon of 2/23

Regardless, it appears the massive cold advection in the mid levels will overcome slight deficiencies in the lower troposphere especially after 6pm tomorrow — including portions of Southwest Kansas.  SPC Day 2 forecast had a "moderate risk" of severe storms from roughly Ness City, KS south along the dryline and points east into Oklahoma.  I will likely be working my first severe event of the season tomorrow in the Dodge City forecast area… should be interesting!  Next post will be about the latest on the possible blizzard behind this storm on Saturday!

27hr NAM forecast valid 9pm CST 2/23 showing surface wind vectors, CAPE (convective available potential energy), and 500mb Temperatures.

February 22, 2007

Central Plains Winter Storm Feb 23-24 [3]

Filed under: Feb 23-24, 2007,General Weather & Forecasting — Mike U @ 7:11 am

An intense, fast-mover.  It appears all the major models have a decent handle on this storm now as we enter the 60-72 hour forecast window.  All the models suggest intense deep tropospheric cyclogenesis over Southwest Kansas early Saturday with the 500mb low bottoming out in the lower 530s.  I made a comparison graphic below, which shows the NAM and the UKMET the slowest solutions.  The ECMWF is still the fastest and farther north with the upper low track.  Regardless of which solution is favored, there will be a swath of intense winter precipitation and wind over a 6-12 hour time frame over portions of western Kansas.  

Comparison of 5 models of the 500mb low position at 6pm CST 2/24

The UKMET solution would favor intense snow and wind here in Dodge City with perhaps a few hours of near blizzard conditions if the snow accumulates enough.  Interstingly enough, the UKMET shows more QPF in the "wrap-around" comma head of the storm over western/northwestern KS than any of the other models.  The UKMET traditionally shows less QPF than any other model in just about any situation.  I would argue that the numerical models are going to struggle with QPF in such strong cyclogenesis during the day Saturday and there very well could be significant snow of 5 to 8" to go along with 40-50mph winds somewhere over the western 1/3 of Kansas by midnight Saturday night.

72hr UKMET 12-hr precipitation forecast valid 6pm CST 2/24

February 21, 2007

Central Plains Winter Storm Feb 23-24 [2]

Filed under: Feb 23-24, 2007,General Weather & Forecasting — Mike U @ 12:32 am

. . . A bit farther south? . . .

The new Feb 21 00z run of the GFS suggests the mid level upper low will close-off over the Texas Panhandle around +84hr to +90hr… a classic scenario for significant precipitation over Southwest Kansas.  As a blizzard lover, this is exactly the kind of 500mb pattern I would be looking for — but there is one problem:  the magnitude of warm air ahead of the system and the overall lack of low level baroclinicity.  At least for here in Dodge City, we may be too warm for significant snow… at least as it stands right now.  That said, it is actually quite a feat to get this kind of deep tropospheric cyclogenesis without cold enough air for snow in Southwest Kansas in February.  A 535 decameter 500mb is usually deep enough to "generate" its own cold air through the column for snow at this time of year.  The question will be how quick this can happen.  A big "kicker" Pacific jet will keep this system on the move, so any blizzard conditions would likely occur for a 6 to 9 hour period perhaps over portions of western Kansas — a lot of uncertainty though.  When it does snow though, the snow rates may be quite high and with 30-50 mph winds… blizzard conditions would most likely be met… including here in Dodge City should this latest GFS run be any accurate.

96hr GFS run valid 6pm CST 2/24 showing the upper low and surface low nearly stacked along the OK-KS border.

Storm chasing this system?  There still remains a possibility of a chase Saturday if a) I am not needed for any overtime at work b) if Dodge City area remains out of the blizzard risk.  I will not chase if it appears we may get blizzard conditions in Dodge City with this storm.. (that’s the blizzard freak in me!).  Anyway, below are two charts from the 21/00z run of the GFS… the first is the 400mb RH and the 2nd is the surface wind and Lifted Index.  (I like to look at 400mb RH because I think it shows the mid-latitude cyclone dry intrusion subsidence and warm conveyor best and roughly the level in the troposphere that water vapor is depicted on the WV satellite imagery)… anyway, using these two charts, and *if* this were a perfect prog, then there should be an enhanced tornado threat over far south-central Kansas shortly not too long after 18z, if any insolation is realized in the mid level dry intrusion.  We’ll see how this plays out in subsequent runs as well as other models.

400mb RH… I like looking at this as a prog for what the water vapor satellite image might look like

Surface wind and surface-based LI suggesting an area of instability near the OK-KS border… notice this area is progged to be at the nose of the mid level dry intrusion in the image above.

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