Rain, Few Storms Tonight; Beautiful Weekend; Severe Weather Monday

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

Current Radar Loops

Local radar loop includes live severe weather warning

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

Make sure you read “Monday’s Severe Weather Concern” at the bottom. 

Tonight – Rain, Few Thunderstorms – 69 at 10 PM

The SPC (Storm Prediction Center) has us under a “Slight Risk” of severe weather for this evening:

What.  We’re under a “Slight Risk” due to a 15% probability of Damaging Winds (58+ MPH) happening within 25 miles of you:

Screen Shot 2014-04-24 at 1.52.02 PM

The line, however, continues to decay as it marches into Middle Tennessee. No real worries with this system.

Rain Totals. Around 0.40″. The cold front creating these storms will quickly slide through after 1 AM, taking these thunderstorms with it.

Friday – Cloudy, Clearing, and Cooler – Wake Up 60 / Afternoon High 74

There is a slight chance there could be a lingering shower before 7 AM, but as we said above, we think the majority of rain will depart in the wee hours of the morning.

Clouds will clear and give way to sunshine by the afternoon.

Saturday A Sunny, Beautiful Day – Wake Up 47 / Afternoon High 81

49° at the start of the race, low to mid 70°s by noon. Light winds 5-10 mph out of the south, very little/no humidity, and a few clouds, all with NO RAIN!

Official Extended NWS Forecast:

Screen Shot 2014-04-24 at 3.26.02 PM

Monday’s Severe Weather Concern

It’s common for one or two runs of a medium range weather model to suggest a severe weather event 3 or more days away. Usually, those models “correct” themselves, and remove the concern.

Over the past few days, however, output from medium range weather models (Euro, GFS) has been generally, and disturbingly, consistent. This has us concerned about what may happen Monday.

Weather models think that on Sunday, a warm front will lift humid air from the south and into Middle Tennessee, setting us up “for a potent dynamical and convective system to develop Monday.” (NWS-Nashville, Morning Area Forecast Discussion, 4/24/14).

Meanwhile, to our southwest (AR-LA-MS), it appears atmospheric ingredients should be in place to create and sustain supercell thunderstorms capable of producing tornadoes, large hail, and damaging winds.

These atmospheric dynamics are forecast to shift northeast and into Middle Tennessee; however, by the time those dynamics are expected to get here (Monday night), the nature of the threat might change from a supercellular concern to a squall-line worry. Both modes of severe weather are potentially dangerous, but we would prefer to see a squall line rather than a mature, rotating supercellular environment. A squall line would pack large hail and damaging straight line winds, but it also represents a decreased tornado threat when compared to the aforementioned supercell environment.

“Any way you slice it . . . the potential is there for an outbreak of organized severe weather across the mid state during this Monday through Monday night time frame. . . but it still looks like the best potential for severe weather will be west and southwest of the mid state during this time period.”  (NWS-Nashville, Afternoon Area Forecast Discussion, 4/24/14).

Bottom line: we think severe weather is possible, if not likely, Monday and Monday night. This may include damaging winds, large hail, and tornadoes. We’re unsure of the exact timing and storm modes, but the potential exists for a significant severe weather event to extend into Middle Tennessee. All this could change, so you need to glue — or perhaps staple — yourself to multiple reliable severe weather sources, especially Sunday and Monday.

This website supplements info @NashSevereWx on Twitter.