jaxjagman

National Weather Service Nashville TN 230 PM CDT Thu Apr 30 2020 .DISCUSSION... Closed upper low/deep trough over the region continues very slow eastward track. Instability from cold-core still expected to pop a few showers along the plateau into the late evening or so. Upper low currently on a southeast trajectory and will move off the Atlantic coast late Fri. Upper ridge will build in behind and bring us dry weather up into Sun. By early Sun, upper ridge breaking down and by this point a cold front is sitting just northwest. This frontal boundary will sink down into the mid-state late in the day, then continue south, reaching the TN/AL border vicinity toward Mon morning. Airmass ahead showing signs of pretty decent destabilization and there seems to be at least a marginal chance of SVR storms, with even a better chance across the northeast late Sun/Sun night. This will be helped along by passing weak upper wave. Upper flow shifts more northwest behind wave Sun night, while system across the plains retreats frontal boundary back just to our north by Mon evening. There is quite a bit of elevated instability Mon thus the scattered strong storm threat continues. GFS has boundary now just to our north pretty active Mon night into Tue, bringing a complex down in northwest flow. EURO now also looking very similar. Areas to our north look to have the biggest brunt at this point, but just a small deviation south will really increase widespread strong/severe chance. Stormy conditions continue after that as well, at least as far as the GFS in concerned. Tue afternoon, and especially Tue night, things look to be more organized once again. SBCAPE/MLCAPE shoot up across KY in the afternoon, then works down here. EBS and SRH both on the increase, and getting into mid-higher end levels. EURO however at this point much different. After Mon night episode, it pretty much favors areas south of us. Be interesting to see how this evolves. Either way, both models giving us pretty much a dry Wed into late week.

https://www.weather.gov/ohx/10thAnniversaryMay2010Flood

APEC looks quite bullish

Subsurface continues to cool,besides region 3

News said it was,quick mesoscale.Those cells around that area had some clearing earlier

Thats what i get when i take my scan off OHX so quick

Stroms just dont have the umph when they show rotation,the best cell seems to be the cell possibly headed towards Rocky Top

This is what i was looking at as well.It's hard to find even PW's even getting to 1.1"

More than i thought..lol Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1237 AM CDT Sat Apr 25 2020 Valid 251200Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE TENNESSEE VALLEY AND SOUTHERN APPALACHIANS... ...SUMMARY... Scattered, strong to severe thunderstorms are expected to develop this afternoon across portions of the Tennessee Valley into the southern Appalachians. A few strong storms may also develop across south Florida. ...TN Valley/Southern Appalachians... Sharp mid-level speed max is forecast to eject across AR into northern AL by 26/00z. This feature is associated with a pronounced short-wave trough that should encourage strong-severe convection across the TN Valley during the afternoon. Latest model guidance continues to suggest a strongly diffluent high-level flow regime will develop across the TN Valley ahead of the short wave and a weak surface low is expected to track from the Boot Heel of MO toward central KY during the afternoon. Very cold mid-level temperatures will spread east, along/north of the cyclonic jet such that steep lapse rates will be common, especially as some boundary-layer warming is anticipated immediately ahead of the Pacific front. While moisture is seasonally low across the Gulf States into the TN Valley, 50s surface dew points should yield modest SBCAPE north of the jet where 500mb temperatures are forecast to be as cool as -18C at peak heating. Forecast soundings suggest surface parcels will reach convective temperature by 17-18z and isolated thunderstorms should initiate within exit region of aforementioned jet. Shear profiles favor supercells and hail may be the greatest threat with this activity; although, low-level shear appears adequate for some tornado potential. Robust convection should spread toward the southern Appalachians by evening where it will encounter a wedge front anchored east of the mountains. Some erosion of the cool boundary layer will be noted across SC into extreme western NC. For this reason have adjusted severe probabilities to account for destabilization in this region. Otherwise, air mass will struggle to recover across the southern Middle Atlantic during the overnight hours. Even so, sustained warm advection does warrant some threat for a few strong storms late.

You want that to clear out or fall apart,especially east of I-65

Think this might be the villain tomorrow,but we'll see

The Euro and GEFS are far apart in the upcoming days with the MJO.Believe ,possible what the GEFS sees is a Kelvin upcoming so it has destructive interference.Models keep showing this other than timing

If the NAM is right but could very well be over doing things there would some strong storms in the mid morning in Mid Tn as the LLJ kicks in,then spreads eastward,seems tho there could be some early junk,looks messy

Yes,starting today The Cumberland Trail opens from 7AM until sunset

I was thinking about going also but man those parks are gonna be packed

Short range models don't even agree with the synoptic for Sat,whats new Mid week, next week the Euro has a system that goes -ve tilt somewhere around the Cen/Plains.Something to watch anyways at this range. Longer range into May could be a Kelvin passing through,but thats to far out to believe and or timing

Hanks pretty damn brave,Oklahoma yesterday,but some great footage

Slightly different look on tonights runs so far

This was the strongest +IOD on record compared to 1994 and 1997,both those years following in winter 1995 and 1998 made it to a moderate Nina to strong Nina.Even in 2006 which is now the actual 4th most IOD event this went into a strong Nina and is the only IOD event that went into a more resurgent Nina in 2008.So seemingly this could be a more moderate Nina is not out of the question

It's going through Tn on this afternoons run.+ tilt,.looks kinda meh right now unless something changes.Also the Euro shows a potent shortwave around the Gulf Shores early Thursday.Some KI but the better Showalter and Theta is south

Yeah buddy

12Z Euro sped up,quite a bit.Sure it will change once again,pretty volatile pattern right now.

Have to wait and see what the first system does.But both the Euro and GFS is hinting at the trough will go -ve tilt somewhere .Euro looks more into the lower Ms/Valley but the GFS is further east around the Friday time frame.GFS seems to want to make the 2nd system the dominant storm tonight with even very little inversion.One of them is going to fail seemingly,the first storm or the next system into possibly next weekend

So basically you'd rather see the tripole warm and not cool,it has adverse effects https://journals.ametsoc.org/doi/pdf/10.1175/JAS-D-11-018.1

Also,if its even right of course at this range this would be seemingly a time where you'd root for the EPO more than anything.Certainly would be a chance of a SER