As we’ve been saying for several days, severe storms require certain ingredients. Most of them were in place, but we were lacking enough cold air aloft to get good updrafts going.
Weather balloon data is back! Shows lapse rates too low for severe weather here. Temps aren’t cold enough aloft to cause clouds to rise/lift fast enough to get robust vertical motion needed to create a storm capable of producing a rapidly rotating updraft (aka tornado).
We are expecting showers and thunderstorms today as a strong storm system moves through the Upper Plains and Great Lakes region. The system will drag a cold front across our area today bringing storms, some of which could be severe.
Last night’s forecast was “no rain until Thursday!”
Uhhhh. Then this morning happened.
Light rain this morning surprised me. Rain was supposed to pass completely south of us. Most of it did. But we still got some this morning. At 5:56 AM NWS-Nashville noted approaching rain in West Tennessee was not reaching the ground thanks to a low level Dry Air Monster.
Dry days ahead!
Pretty warm, too.
Rain and storms may start late Wednesday night/wee hours Thursday morning.
South winds will be strong. The Euro model thinks winds will gust over 40 MPH. Storm strength will depend on instability and dewpoint levels. No two storm events are the same, but this looks pretty similar to what we saw yesterday/Saturday — plenty of wind energy, questionable instability. As usual, considerable uncertainty, especially this far away.
Last night’s storm reports weren’t from storms but from the Wind Advisory. “Non thunderstorm-winds,” they call it.
Rain reached 2″+ in spots yesterday. Creeks and streams rose quickly and fell not as quickly. A few rivers reached pre-flood “action stage.” For more on that, this.
The rain is over. Storms have moved on to our east, allowing for our the tornado watch including Davidson and Williamson counties to be cancelled. We remain under a wind advisory until 9PM.
Sustained winds of 15 to 20 mph, gusting up to 30 mph, are expected for another hour or so, becoming calm by midnight.
