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Warm Before the Plunge!

9:15 am in Uncategorized by Ted Keller

Computer Model Temperature Forecast

It may not seem like it this morning, but warmer days are just ahead! Enjoy them while you can.

The turn to a south wind and milder conditions begins tomorrow.  Sixties are in the bag for Friday and through the weekend and into early next week.  A rouge seventy or two could be lurking in the mix as well!

Large temperature swings, as always, are dictated by changes in the jet stream flow.  Generally, when the flow dips over the western U.S. while rising over us, we experience warmer conditions.

The question is will the dip in the jet result in an eventual storm for us?  The latest computer model guidance suggests the pattern will shift dramatically toward Thanksgiving, with much colder air replacing the warm.  Depending on the nature of smaller disturbances in the flow, a cold front may simply advance through or may stall and develop “waves” or bumps of disturbed weather, some of these can occasionally go on to produce deep storms.

The latest computer models keep hinting at waviness in the arctic front sometime around Wednesday and Thursday, followed by a substantial drop in temperature.  Lows could dip below twenty by Black Friday morning! 

Since the models have been doing some waffling regarding the timing and position of the frontal waves, I still can’t determine whether winter precipitation of any consequence is possible on Wednesday or Thursday.  As always, I will have the latest look at the situation on KOLR/KSFX tonight.

VToo.2 Update #1 Sunday June 6th

1:54 pm in Uncategorized by Ted Keller

Well, we’re heading for the first target area of the trip, which will be northeastern Colorado. We are seconds from crossing into Colorado from Kansas.  I’m having an issue with our GPS device in case you’re wondering why the position isn’t working.

Some encouragement came when the SPC actually put a minimal (2%) tornado risk out with the late morning update! 

It is interesting that a NW-SE boundary of maximum dew points has set up this afternoon in northeastern Colorado.  There is also edvidence of pre-convection occuring in northern Colorado and southern Wyoming.  For these reasons plus the fact that we’ll need to be in western Nebraska for Monday’s initiation made us decide to head to Sterling, Colorado this afternoon, ETA about 4 pm MDT.

Table Rock Tornado/Saturday Storms, April 24, 2010

7:46 pm in Uncategorized by Ted Keller

Storm Front 4/24/10 - Hwy 65 - Amber Nicholson

The atmosphere did produce storms and severe weather, including a tornado, on Saturday afternoon April 24, 2010.  As reviewed in my blog post early on Saturday, the conditions did end up being favorable for a tornado but further west than I think anyone would have thought.

Several storm lines where pivoting around an upper level low on this day.  Sunshine in-between these lines was allowing air to become unstable, feeding the next line.  There were three of these yesterday.

The first was swinging through the extreme eastern and northeastern portion of the KOLR/KSFX viewing area.  One cell along this line was exhibiting rotation aloft in southern Phelps County (the height of the radar beam at that distance makes the direct detection of low level rotation impossible) and was enough to issue a tornado warning.

The second line formed in northern Arkansas and moved NNE.  This was the one that blew through Greene County (photo left).  Strangely, a tornado was generated by this by a cell in this line at Table Rock State Park at about 1:40 pm (official NWS report here).  This tornado not obvious on radar and I would classify this as a bottom-up tornado where some sort of rotation near the surface was “spun-up” into a strong thunderstorm updraft. This stretches the rotation, decreases the radius of the rotation and causes an increase in wind speed.

The storm at about the time or shortly before the tornado had a strong updraft as noted in the 3D image.  North is left, south is right in this picture.  A strong updraft will often suspend larger rain droplets (or hail) aloft, leading to “weak echo region” (WER),  This mini “WER” is circled in the image. In large supercells, this feature is often very large and tall.  In this case, all of this is under 10,000 feet (legend on left of image). 

3D Reflectivity at 1:30 pm

Weak rotations were detected at the surface but had virtually no depth to them.  The nature of this type of tornado makes it difficult to tag these circulations as tornadoes.  The vast majority of these weak circulations (and there are often very many in thunderstorm lines/areas) do not produce a tornado so it cannot be assumed that a tornado is present.

Just to let you know, these types of tornadoes may not be warned upon for a long time.  It would take smaller radars scanning continuously, combined with more knowledge of how these types of storms form AND a dissemination system quick enough to warn people!

Potential Snow Wednesday

11:06 am in Forecast Discussion, Uncategorized by Ted Keller

wednesday_snow

There continues to be support for a band of snow in the Ozarks for Wednesday afternoon.  The exact track is not known but the consensus seems to be for areas southeast of Springfield.

While snow may fly, it is important to note that because of the unusually warm November we’ve experienced, ground temperatures are warm for the season which would inhibit snow accumulation.  Temperatures at the ground will likely be above freezing during most of this as well.

On the other hand, morning model runs are showing strong rising motion with this system and a favorable track of the storm in the upper atmosphere.  Cooling at the surface Wednesday afternoon may be greater than originally thought.

There is not enough confidence in this sysyem to suggest any snow totals for the Ozarks at this time.

Severe Update 4:40

4:42 pm in Severe Storms, Uncategorized by Ted Keller

radar0433This is the same segment discussed eariler today, moving slower than I originally thought.  It blew out some windows in Neosho.  ETA for Springfield about 5:30 p.m.

Snow nearby?

12:46 pm in Uncategorized by Ted Keller

It’s conceivable that snow could fall or be mixed with rain late Friday with a front, a small low pressure area and some very cold air!

Two computer models are in partial agreement over this. The details of when and where tonight on KOLR!

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