Friday, May 21, 2010

Thursday, May 20, 2010

May 20 Severe Weather?


A day of light to moderate rain and embedded thunderstorms during the evening hours last night left areas of Kansas City with another 0.75-1.25" of rain on the already wet ground. Additional rainfall today will not be as widespread or as significant, thus expect the flooding threat to diminish over the local Kansas City area. Other areas of Missouri will see a flooding threat continue through the day as heavier rains with embedded thunderstorms continue, and another round of general moderate rainfall occurs over eastern portions of the state overnight tonight.

Main concern for this update is the potential of some severe weather this afternoon and evening over parts of extreme eastern Kansas and western Missouri. The upper level low currently centered over central Kansas will slowly progress eastward in conjunction with the surface low currently along the KS/OK border. Cold air aloft will allow for at least some destabilization of the lower levels given at least some sunshine this afternoon over these areas. If some clearing can occur, expect at least 500 J/kg of instability with upwards of 1000 J/kg of most-unstable CAPE being possible. At least marginally severe hail should be realized if sufficient instability values can be reached over parts of western Missouri. If low level instability can be realized with surface heating this afternoon, fairly substantial turning in the lower portions of the hodographs may allow for the risk of tornadoes just ahead of the surface low pressure system where winds will be southeasterly. At this time there is undoubtedly some concerns with the setup, but the main concern will be whether or not some clearing will occur to allow the destabilization needed.

This will be a fairly narrow corridor for severe weather this afternoon where enough destabilization can occur and the low level wind fields are supportive. Latest SPC outlooks have this area defined fairly well  at the moment.

An update tomorrow may reflect on any severe weather that occurs today and otherwise look at the upcoming pattern of very warm and humid weather!

Tuesday, May 11, 2010

Severe Weather Continues...


Severe weather across the Plains states continues today and is expected to continue tomorrow as well. Yesterday's event were well documented and have been all over nearly every national news station and even local news stations last night and today. Tornadoes threatening two well populated areas, Wichita and Oklahoma City, and unfortunately impacting one (Oklahoma City) causing 5 deaths and numerous other injuries. Tornadoes continued across other parts of southern Kansas and throughout Oklahoma, even as far south of the Red River Valley. I'm not going to spend too much time to rehash all of these details as I'm sure everyone has read all about them by now...

Today's storm threat was fairly condition despite having great instability and shear present, due to the strong elevated mixed layer that capped all attempts at convection until ~8PM. Since then we have a few thunderstorms along the warm front in Illinois and into eastern Missouri, as well as a severe/tornadic thunderstorm in northwest Oklahoma. Additional storms should continue to fire and the current areas of thunderstorms expand through the evening and early overnight as a strong low level jet creates good lift across the frontal boundary. For this reason the SPC has issued a new tornado watch that covers areas of Oklahoma and Kansas, with additional watches (likely severe) being needed later tonight. The main threat with storms beyond the 10pm time-frame will be large hail given the steep lapse rates and good elevated instability. These storms will likely move out of Kansas during just before sunrise, and exiting western Missouri by mid-morning. This will likely set the stage for another severe weather event across portions of Kansas and Missouri as well as some adjacent areas (to a lesser extent).

By late afternoon tomorrow a warm front should be situated from near the KS/MO border across northern Missouri and through central Illinois, Indiana and Ohio. Dew point values in the mid to upper 60s can be expected to the south of this boundary and to the southeast of a cold front that should be positioned from Manhattan, KS southwest through Enid, OK and into north-central Texas. Surface profiles suggest widespread 2000+ J/kg of surface based instability with areas of 3000 J/kg likely occurring in areas where moisture can pool along/near boundaries. A fairly stout elevated mixed layer should keep any initiation at bay until late afternoon and evening hours with northern Missouri likely seeing convection before areas of eastern Kansas due to slightly cooler temperatures aloft. Bulk shear values of 45-65 kts will easily support supercells capable of very large hail throughout the warm sector. Southerly winds at the surface through much of eastern Kansas/Oklahoma will likely limit tornado potential somewhat through those areas, although isolated tornadoes will likely not be ruled out. A higher likelihood of tornadic supercells will exist in areas where surface winds can back (become southeast), likely east of a developing low near the KS/MO/NE intersections. Stronger low level turning of the hodographs will exist here and likely promote a higher risk of tornadoes over northern Missouri and perhaps into northeast Kansas as well. Convection will likely continue to expand into the early overnight hours, into perhaps line segments as the low level jet increases the forward motion and provides more unidirectional shear. This will provide more of a focus for large hail and perhaps damaging winds into the overnight hours for parts of eastern Kansas and areas of northern/central Missouri. Another concern with convection tomorrow evening/overnight will be the potential for flooding given some likelihood for the training of these thunderstorms along/just ahead of the cold front and near the frontal intersection for parts of Kansas and Missouri.

A few more rounds of showers and thunderstorms look to be possible through the end of the week. However, nothing prominently severe looks to occur at this time...

Monday, May 10, 2010

May 11 Severe Weather Potential

Wasn't able to get an organized post together for the severe weather threat upcoming on Monday. Needless to say given the hype from all of the news sources and meteorological sources is that this could be a fairly significant event. The potential does exist for strong and long-lived tornadoes, perhaps from the late afternoon through the evening and continuing into the early overnight hours before storms congeal into more of a linear mode. In addition to the tornado threat, expect very large hail and damaging winds (especially overnight).

There will be plenty of chasers, spotters, research groups, media and locals out trying to chase these storms that will likely be carrying a forward speed of 35-45 mph. This will make it an interesting challenge for everyone to stay safe out there, and hopefully everyone does!

I work the evening shift tomorrow and will likely be there late as storms roll into the Kansas City area between 9pm-12am. I will not likely update the blog until after the event has passed...

Thursday, May 6, 2010

April 6 Chase

Currently out chasing in eastern Kansas... View the Live website page for current video and GPS tracking!

Monday, May 3, 2010

April 29 Chse Recap

Took a trip back home for the weekend, thus the late response to recap last Thursday's storm chase which yielded two tornadoes that have both been confirmed by the NWS offices. A complete recap will be posted later today, with images likely being available sometime later...

For more information regarding updates while on the chase last Thursday, please visit the new blog site for Severe Plains: