Today brings a risk for severe thunderstorms, capable of damaging winds and marginal hail. The Storm Prediction Center has the risk over most of Middle Tennessee, except for a small corner to the north east. Here is the SPC’s discussion…
…GULF COAST STATES TO SERN ATLANTIC COAST…
AS MENTIONED IN THE SYNOPSIS…SEVERAL MIDLEVEL IMPULSES ARE EVIDENT IN MORNING WATER VAPOR IMAGERY TRANSLATING GENERALLY EWD ALONG LOW-LEVEL BAROCLINIC ZONE. VISIBLE SATELLITE IMAGERY SHOWS MORE EXTENSIVE CLOUD COVER THIS MORNING ACROSS THE TN VALLEY INTO THE CNTRL/SRN APPALACHIANS. HOWEVER…AREAS TO THE S WILL LIKELY EXPERIENCE STRONG DAYTIME HEATING. WHEN COUPLED WITH LOWER/MID 70S DEWPOINTS…ENVIRONMENT WILL BECOME MODERATE TO STRONGLY UNSTABLE BY AFTERNOON. ALSO OF NOTE…12Z OBSERVED SOUNDINGS AND CURRENT VWP DATA SUGGEST A BELT OF 30-35 KT FLOW PRESENT IN THE 3-6 KM AGL LAYER…WHICH WHEN COMBINED WITH THE STRONG INSTABILITY WILL LIKELY FOSTER CORRIDORS OF MORE INTENSE STORMS…PRIMARY IN ADVANCE OF THE MORE PERSISTENT MIDLEVEL IMPULSES. THE PRIMARY HAZARD WITH THESE STORMS WILL BE DAMAGING WIND GUSTS.
The clouds preventing heating have, for the most part, dissipated. All that remains are lower level cumulous pockets and those wont affect how the atmosphere heats. Now that the atmosphere is heating, we will gain some fairly strong CAPE values, but mainly by evening. These storms look like they will show up mainly at or after 7 PM, with 2-3 j/kg CAPE and some pretty nice Helicity values. I haven’t seen helicity like this over Tennessee in a while, so it could be nice. This helicity will also allow for the possibility for tornadoes, with the EHI model showing values ranging from 1-3 over a large area, mainly over western portions of the mid state.
So, in summary…
Thunderstorms will be widespread across the state, mainly this evening but a scattered thunderstorm cannot be ruled out before then. There will be large amounts of instability and shear, allowing for thunderstorms with threats mainly being damaging winds/hail. Tornadoes cannot be ruled out as well.
I am hoping to catch one of the earlier storms, and maybe even tonight’s storms. Check back for updates!
Update: all of Middle Tennessee is under a Flash Flood Watch
