April 23rd Eastern Nebraska Storm Chase

04-23-10 CHASE LOG:  NE

This ended up being a somewhat disappointing chase overall, but it was certainly good to just see some storms!Our group consisted of me, MaryLynn Nelson, Peggy Willenberg, and Beau Gjerdingen.The forecast was for severe storms to develop across eastern NE on an occluded front, warm front, and dryline by the late afternoon hours and especially into the early evening.After staying in Omaha the night before, our course of action was to drive to Lincoln, NE and re-evaluate towards midday.Storms were already starting to fire on the occlusion to our west at this point and a tornado watch has been issued for this area.After a few hours, we traveled to York, NE on I-80 thinking that these storms could develop back down on the boundary and we could at least have a look at them.The Interstate also offered a quick escape east in case additional storms would fire across eastern NE where the better moisture and low level shear resided.Storms did not end up building down the boundary and the dryline was quickly approaching our location with the occlusion being lifted well north.A nice cumulus field began to develop across far eastern NE and northeast KS, so we ended up moving east on I-80 all the way back to Omaha in the vicinity of the moisture and convergence axis.Our first storm of the day began to develop around 15 miles south of Omaha near 6pm.This storm was moving due north-northwest towards our position so we stayed put.All the while, new storms and turkey towers were starting to form all around us but were finding themselves very difficult to break the cap and sustain their updrafts.The aforementioned storm did end up moving just to the west of our position while new storms developed along a convergence boundary near Lincoln, NE.These storms near Lincoln quickly went severe with large hail and even a tornado warning but we decided to stay on the more northern cell, following the storm north on Highway 133 out of Omaha towards Blair.As we approached the base between Omaha and Blair, we headed west on a dirt road and found ourselves staring at a beautiful vault/updraft and lowering underneath the storm.At this time, the anvil started to produce some nice mammatus as well.This storm ended up weakening some and new updrafts were starting to our north so we continued to follow these cells to the northwest towards Fremont and then eventually to West Point, NE where we finally gave up the chase and ended up core punching into some pea size hail.South of West Point, we did see a nice non-rotating wall cloud that only stuck around for several minutes or so.

Definitely a disappointing chase considering how good the low level shear along the boundaries was forecast and how it looked per the Mesoanalysis during the event.One thing that I was very worried about before the event was the lack of upper level winds.The main upper level jet had been forecast and ended up being well south of the area and the reason why portions of MO ended up having quite a bit of severe weather.In addition, there was a stronger cap than expected as shown on the special 20Z sounding out of Omaha.This was even more evident on the Topeka sounding.Another factor was the late arrival of the shortwave to the area that finally made it by 00Z ignited all the storms in the area during the evening and primarily after sunset.I also noticed that the inflow into these storms was quite chilly but with dewpoints around 60 degrees so moisture was not much of an issue.

omaha-storm113
omaha-storm113

Storm updraft developing very quickly directly over Omaha, NE.

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omaha-storm22

Beautiful vault and base on this storm near Omaha, NE.

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omaha-storm33

A closer view of the storm base and associated strong updraft region of storm near Omaha, NE.

omaha-storm44
omaha-storm44

Fuzzy picture of brief lowering on storm near West Point, NE shortly after sunset.

More photos from this day can be found here: http://www.flickr.com/photos/39991047@N02/sets/72157623800381923

100423_rpts
100423_rpts

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