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New Severe Chances for Tonight, Plus Severe Wx Tomorrow Night

Current Official Hourly Observation (taken at :53 on the hour)

Current Radar Loops

Temp & Rain Probabilities Next 36 Hours (auto-updating)

You’re going to hear a lot about severe weather today and tomorrow. But, first things first.

Afternoon NWS Severe Weather Briefing (good summary of what’s below):

TodayIncreasing Clouds – High 81°

TonightRain/Storms, with a Small Chance of Severe Weather – 10 PM 70°

The new run of the HRRR (below) still thinks a shower/thunderstorm blob will arrive around 8 PM tonight:

The Storm Prediction Center has moved today’s outlook for severe weather much closer to us, such that the yellow “Slight Risk” area now sits tangent (touching, but does not include) to both counties:

Tonight’s probability of damaging winds (58+ mph) and/or large hail (1″+) happening within 25 miles of you is 5%; if you go one county to the west, that probability increases to 15%. Wind, then Hail, outlooks are shown below:

We are excluded, barely, from tonight’s tornado probability outlook:

ThursdayOff/On Rain & Thunderstorms Early; Some Severe Weather Potential Late – Wake Up 63°, PM High 77°

Rain occurring tonight/overnight/early Thursday will end, replaced by a humid airmass riding transported by south winds.

From the NWS (in blue):

Attention then turns to the west as [a] severe weather outbreak [is] expected to get underway Thursday afternoon across Louisiana, Arkansas, and Missouri, then spread into Mississippi, West Tennessee, and Western Kentucky by Thursday evening.

Here’s the outlook from the Storm Prediction Center for Thursday:

If you’re traveling west Thursday, you need to be very aware of the weather around you. This is a dangerous severe weather setup, especially for the area outlooked in red, above.

We’re under a “Slight Risk.” The same weather system forecast to occur in the above-outlooked red region will move east into Middle Tennessee.

Here’s the good news: any widespread/substantial severe weather is expected to weaken by the time it reaches the Tennessee River very late Thursday night/early Friday morning:

BTW, it occurs to me everyone may not know exactly what we’re talking about when we refer to the Tennessee River. See the yellow line inside the black rectangle, below:

Anyway, once the system reaches the Tennessee River very late tomorrow night, it’s expected to weaken. Back to the NWS:

Weather models (GFS, Euro, SREF, NAM) all indicate storms will undergo significant weakening after reaching the Tennessee River and spreading eastward across [Middle Tennessee] after 1 AM Friday morning.

Reasons for weakening:

1.  The storms will be running away from the main axis of instability, which will be located in Arkansas.

2.  Strong storm-supporting winds near the “top” of the atmosphere will be moving north, and out of Middle Tennessee.

3.  The nighttime ETA means the sun won’t be out to further destabilize our atmosphere as the storms arrive.

The result: diminished severe weather ingredients. For the wxnerd, CAPE values will be around 1,000, and there will be a mature-storm-killing veer-back-veer wind profile.

All that said, severe weather remains possible for us while we sleep. The severe ingredients will be decreasing, but they’ll still be there. The main threats are damaging winds and large hail, and an outside chance of a tornado or two.

Notice this from the SPC’s Probabilistic Outlook for late Thursday night. We’re in the shaded (“hatched”) area:

This means that despite the anticipated weakening, the probability of a significant severe weather event (significant: near-hurricane force winds) happening within 25 miles of you while you sleep tomorrow night is at least 10%.

Storms may rejuvenate during the daylight hours Friday, but if that happens it will most likely occur east of us.

Additional info coming later today.

This website supplements content found @NashSevereWx on Twitter.

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