A recap of the Tornadoes that occurred on May 20 in Western Missouri has been posted on the new Severe Plains Blog:
http://severeplains.com/blog/?p=900
http://severeplains.com/blog/?p=900
Friday, May 21, 2010
Thursday, May 20, 2010
May 20 Severe Weather?
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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!
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...
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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...
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...
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!
http://www.severeplains.com/live.html
http://www.severeplains.com/live.html
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:
http://www.severeplains.com/blog
For more information regarding updates while on the chase last Thursday, please visit the new blog site for Severe Plains:
http://www.severeplains.com/blog
Thursday, April 29, 2010
Head to New Blog For Updates!!
A Reminder:
Please head to the new blog site for the latest updates while chasing!
Severe Plains Blog
http://www.severeplains.com/blog
Please head to the new blog site for the latest updates while chasing!
Severe Plains Blog
http://www.severeplains.com/blog
Wednesday, April 28, 2010
April 29, 2010 Chase Forecast
Chase #1 of 2010!
Time of Departure: ~12:30PM
Initial Target: Herington, KS
Discussion: Initial low pressure system over Nebraska will swiftly progress northeast into northern Minnesota by late evening. A trailing cold front will surge east/southeast over MN/IA/NE and into northern Kansas during the evening, intersecting with a dryline positioned over central Kansas/Oklahoma. Largely linear forcing expected along the cold front in the Northern Plains preludes any significant tornado risk despite very strong shear values given the howling winds throughout all levels. Thunderstorms should initiate along this cold front during the evening hours, likely unzipping the front the entire way from southern Minnesota into southern Nebraska and along the Kansas/Nebraska border. As this occurs a secondary low is forecast to form in central Kansas, enforcing the dryline and providing a source for some localized backing of the winds. As this occurs it would appear likely that convective initiation should ensue given enhanced convergence. Bulk shear values are undoubtedly sufficient for supercells during the evening with an increase in shear likely with the low level jet increasing and proving south-southeast winds at the surface during the early overnight. Moisture is a concern given only mid to upper 40s exist widely in the area of interest, however continued strong southerly flow should provide ~60 surface dew points by 00z tomorrow. Widespread 1000-1500 J/kg of mixed-layer CAPE should exist, however fairly substantial capping inversion should limit any development without the aid of at least moderate surface convergence. Given surface temperatures of mid 80s and dew points ~60, high LCL values are also of concern for tornado potential. Nonetheless, the risk is there for at least a storm or two to develop along the dryline or for the cold front to initialize a storm near the intersection of the two boundaries.
It is for this purpose that the initial target be just south of the expected cold front and dryline intersection, being close enough for a tail-end charlie situation along the front or close enough to close quickly on any development to the south along the dryline. Will update by early afternoon with additional thoughts after viewing the 00z runs tonight and the 12z runs tomorrow morning; along with a look at the current conditions as a fellow co-worker and I depart.
Time of Departure: ~12:30PM
Initial Target: Herington, KS
Discussion: Initial low pressure system over Nebraska will swiftly progress northeast into northern Minnesota by late evening. A trailing cold front will surge east/southeast over MN/IA/NE and into northern Kansas during the evening, intersecting with a dryline positioned over central Kansas/Oklahoma. Largely linear forcing expected along the cold front in the Northern Plains preludes any significant tornado risk despite very strong shear values given the howling winds throughout all levels. Thunderstorms should initiate along this cold front during the evening hours, likely unzipping the front the entire way from southern Minnesota into southern Nebraska and along the Kansas/Nebraska border. As this occurs a secondary low is forecast to form in central Kansas, enforcing the dryline and providing a source for some localized backing of the winds. As this occurs it would appear likely that convective initiation should ensue given enhanced convergence. Bulk shear values are undoubtedly sufficient for supercells during the evening with an increase in shear likely with the low level jet increasing and proving south-southeast winds at the surface during the early overnight. Moisture is a concern given only mid to upper 40s exist widely in the area of interest, however continued strong southerly flow should provide ~60 surface dew points by 00z tomorrow. Widespread 1000-1500 J/kg of mixed-layer CAPE should exist, however fairly substantial capping inversion should limit any development without the aid of at least moderate surface convergence. Given surface temperatures of mid 80s and dew points ~60, high LCL values are also of concern for tornado potential. Nonetheless, the risk is there for at least a storm or two to develop along the dryline or for the cold front to initialize a storm near the intersection of the two boundaries.
It is for this purpose that the initial target be just south of the expected cold front and dryline intersection, being close enough for a tail-end charlie situation along the front or close enough to close quickly on any development to the south along the dryline. Will update by early afternoon with additional thoughts after viewing the 00z runs tonight and the 12z runs tomorrow morning; along with a look at the current conditions as a fellow co-worker and I depart.
Tuesday, April 27, 2010
April 29 Severe Weather Forecast #1
A nice and cool day today with temperatures only into the low to mid 60s over the region. A few showers were able to develop thanks to the abundant sunshine and cool temperatures aloft, however nothing widespread or too significant. We'll see the winds turn to the south during the overnight tonight, beginning to bring back the warm and moist air that was shunted southeast with the cold front this past weekend. This will set the stage for a severe weather event Thursday evening and overnight as a large trough moves eastward onto the Plains.
Details are still sketchy despite being only 2 1/2 days out, with the GFS still playing catch-up with the NAM and especially the ECMWF/GEM models. Strong southerly flow at the surface and above the surface should yield sufficient moisture return with ~60 surface dew points to the Central Plains by Thursday evening. This southerly flow will continue into the evening hours, and combined with strong flow in the mid-levels from the west-southwest will yield strong shear values over the area of interest. The combination of instability and shear does yield 0-3km EHI values of 3-4 which given a surface based storm would likely be more than sufficient for rotation in the lowest portions of the storm. Other parameters to note would be mixed layer CAPE of 1000-1500 J/kg, deep layer (0-6km) shear of 45-55 knots with a vector more normal than not to the boundary over south-central Kansas and Oklahoma. Such strong wind fields throughout all of the levels will end up giving fairly quick storm motions of 30-40 mph to the northeast, which would be favorable for any storms moving off of the dryline and into an even higher dew point environment.
All of the above parameters would be more than sufficient for strong rotating supercells likely capable of tornadoes given the strong deep layer and storm-relative shear. However, there are definitely some negatives at this point with the setup on Thursday. Moisture return will be sufficient for thunderstorms, however given surface temperatures of 80+ degrees F will give way to ~20 degree F dew point depressions and LCL heights of 1500 meters or higher. This decreases the tornado potential initially, but with storm modification of the surrounding environment could definitely still yield tornadoes. A pronounced warm nose in the lower levels will also give way to some substantial inhibition for surface based parcels to initially develop. There are of course many other details which will hopefully become better defined by tomorrow night, but for now it does appear that the positives outweigh the negatives on this setup for severe weather.
An additional update is likely by tomorrow night, with the final details regarding my chasing opportunities with this setup. A quick glance beyond Thursday doesn't give much model consensus, but it would appear that a continued threat of showers and thunderstorms would appear likely.
Details are still sketchy despite being only 2 1/2 days out, with the GFS still playing catch-up with the NAM and especially the ECMWF/GEM models. Strong southerly flow at the surface and above the surface should yield sufficient moisture return with ~60 surface dew points to the Central Plains by Thursday evening. This southerly flow will continue into the evening hours, and combined with strong flow in the mid-levels from the west-southwest will yield strong shear values over the area of interest. The combination of instability and shear does yield 0-3km EHI values of 3-4 which given a surface based storm would likely be more than sufficient for rotation in the lowest portions of the storm. Other parameters to note would be mixed layer CAPE of 1000-1500 J/kg, deep layer (0-6km) shear of 45-55 knots with a vector more normal than not to the boundary over south-central Kansas and Oklahoma. Such strong wind fields throughout all of the levels will end up giving fairly quick storm motions of 30-40 mph to the northeast, which would be favorable for any storms moving off of the dryline and into an even higher dew point environment.
All of the above parameters would be more than sufficient for strong rotating supercells likely capable of tornadoes given the strong deep layer and storm-relative shear. However, there are definitely some negatives at this point with the setup on Thursday. Moisture return will be sufficient for thunderstorms, however given surface temperatures of 80+ degrees F will give way to ~20 degree F dew point depressions and LCL heights of 1500 meters or higher. This decreases the tornado potential initially, but with storm modification of the surrounding environment could definitely still yield tornadoes. A pronounced warm nose in the lower levels will also give way to some substantial inhibition for surface based parcels to initially develop. There are of course many other details which will hopefully become better defined by tomorrow night, but for now it does appear that the positives outweigh the negatives on this setup for severe weather.
An additional update is likely by tomorrow night, with the final details regarding my chasing opportunities with this setup. A quick glance beyond Thursday doesn't give much model consensus, but it would appear that a continued threat of showers and thunderstorms would appear likely.
Monday, April 26, 2010
A Few Nice Days Ahead
A few showers remained in the area today with the upper level low still hanging around over Iowa. These showers pivoted around the low this evening and will continue to do so overnight, giving areas a few hundredths to a tenth of an inch of rain in the heavier bands. A nice scene this evening in Kansas City with the showers moving through as the sun was lowering, created both some high contrast dark clouds and a nice sunset scene (including a brief rainbow). We'll dry out tomorrow and continue to remain dry with warming temperatures for Wednesday and Thursday.
The next chance for rain and severe weather for that matter will come on Thursday for the Central Plains. A deepening trough in the west will eject several waves of energy for late this week and through the weekend. Model forecasts have been very inconsistent in what the system will do in regards to a cold front Thursday night. This will have dramatic affects on both precipitation and especially severe weather chances for Friday and the weekend. A quick look at the potential on Thursday shows a great chance of thunderstorms given the strength of the forcing along the cold front that will likely be sweeping southeast across the Plains. A lot of questions still need to be answered regarding the specifics, but it would appear likely that at least a strong line of thunderstorms would sweep over parts of the Northern and Central Plains Thursday evening and overnight. Additional details regarding the severe weather potential on Thursday and the remainder of the week will be addressed in later updates. Finally have a few days off with what looks to be an active pattern, so may finally get a chase day in as well!
The next chance for rain and severe weather for that matter will come on Thursday for the Central Plains. A deepening trough in the west will eject several waves of energy for late this week and through the weekend. Model forecasts have been very inconsistent in what the system will do in regards to a cold front Thursday night. This will have dramatic affects on both precipitation and especially severe weather chances for Friday and the weekend. A quick look at the potential on Thursday shows a great chance of thunderstorms given the strength of the forcing along the cold front that will likely be sweeping southeast across the Plains. A lot of questions still need to be answered regarding the specifics, but it would appear likely that at least a strong line of thunderstorms would sweep over parts of the Northern and Central Plains Thursday evening and overnight. Additional details regarding the severe weather potential on Thursday and the remainder of the week will be addressed in later updates. Finally have a few days off with what looks to be an active pattern, so may finally get a chase day in as well!
