I’m going to keep this update rather brief since it’s getting late, but I wanted to give everyone across the Central Plains a big heads up on the potential severe weather outbreak tomorrow. A shortwave trough is currently located in the western United States and will move over the Central Plains during the day tomorrow. A frontal system is currently located over Kansas, which will lift northward as a warm front throughout the day tomorrow. This warm front will sit along the Kansas/Nebraska border as a surface low quickly strengthens in Colorado and eventually moves eastward along the Kansas/Nebraska border into Missouri and Iowa. Ahead of a cold front that will extend from the surface low pressure system and south and along the warm front is where rapid supercell development will be likely tomorrow.
To break all of this down a little further and make it a little easier to understand, temperatures are going to climb well into the 80s and dew points will be well into the 60s along and south of the warm front. This will allow the environment to become increasingly unstable throughout the day on Tuesday, and the mid to upper level system that will be moving over the region during the day on Tuesday will provide sufficient wind shear, which will allow for rapid supercell development. Many of these storms could become tornadic with a few of these tornadoes likely being strong. Damaging winds and very large hail will also be likely with any supercell that develops. Because of the parameters that will be in place, the environment will be conducive for these air parcels to quickly accelerate upward, condense, and develop into towering supercells.
Storms will begin developing into the afternoon in Kansas and Nebraska and will eventually push eastward into Iowa, Missouri, and Illinois. To get more specific, the initial threat will begin in Kansas and Nebraska particularly along the Kansas/Nebraska border, where the warm front will be located, and northward into central and eastern Nebraska. An area that may be currently being overlooked is in western Kansas, where initially a supercell or two may try to develop and become tornadic, quickly moving northeastward. If earlier convection does not hinder any later development, tornadoes across the regions that I just mentioned will be likely. The threat will then push eastward into northern Missouri, the lower two-thirds of Iowa, and eventually into Illinois into the evening and overnight hours. Later into the evening/overnight hours, these storms may try to cluster up, and while the tornado threat would continue, damaging straight-line winds would also be a big threat.
If you do not like the Firsthand Weather Facebook page, be sure to go like it. I will be putting numerous updates on that page throughout the day tomorrow! Please share this post to get the word out to those that will likely impacted by this potentially significant severe weather event.
Update at 1:30 pm EDT: I wanted to share my tornado outlook map and the discussion that I shared along with it. The forecast above that I posted last night still looks good given the latest model guidance. Below is what I posted on the Facebook page about an hour ago.
Discrete supercells will likely develop later this afternoon and evening inside and around the outlined region on this map. Given the expected environmental conditions, many of these storms could quickly become tornadic, some of which could be strong. I am still watching the possibility of some lone supercells developing in parts of Kansas, but the main risk will be across Nebraska and will eventually extend into portions of western Iowa and northwestern Missouri. The Nebraska/Kansas border needs to be watched closely also, right along the warm front, and also into southern portions of South Dakota.
Again, supercells capable of producing tornadoes will rapidly develop later this afternoon. Some of these tornadoes will be strong. A damaging wind threat will likely extend eastward into Iowa, northern Missouri and eventually Illinois later tonight. Please refer to my earlier Facebook updates for more details on that.