nrgjeff

There is the MD for which I'm waiting. If the SPC and I draw the same boundary and forecast, is that a good sign or a bad sign? At any rate instability and low level turning with height will increase markedly when it all comes together West Kentucky and northwest Tenn. Any discrete cell(s) will ingest it all. However that whole MD may get whacked by wind too. MEM south is at risk for QLCS tornadoes.

Wednesday April 13: My target area has shifted, though I do not plan a real chase. Virtual target is north of my previous post last night. Dyersburg, esp the flatter area west of is my target. Lunch in Dyersburg would have been nice! Mississippi dewpoints are under-achieving, not a shock given MCS. Also 800mb is warm on most soundings and fcst soundings (between standard constant press level charts). That means Miss has to work even harder to recover surface T/Td. Yes it'll hit 80 deg. However it might not be enough. Meanwhile outflow boundary OFB lifts north into northwest Tenn. 800mb will cool sooner there. Temps and Dews will almost match Mississippi. In fact dews could recover better, circumnavigating the mixed air over Miss. Dotted green is edge of the more pronounced lower T/Td. Yellow line is the chaser's OFB. It is forecast to lift into the red position by late afternoon. Prefrontal trough is not drawn, but I expect the red OFB to intersect it in northwest Tenn. Hence chase target. 1KM SHR below satellite, numerical models NWP shows my conceptual model. However NWP could misplace the OFB. NWP has robust cells on its intersection with the pre-frontal trough. Chaser would follow the boundary, not the NWP. Just good to see the conceptual model confirmed.

Oh wow! Aluminum bats carry the ball better than wood. Odd decision making. Kind of like chasing the South, haha!

Most of that Moderate is wind driven. However the southern quarter of the MDT is 15% tornado, which straddles the Arkansas and Mississippi border. Pre-frontal trough is quite likely along that AR/MS state line, and eventually moving into Mississippi. Outflow from morning rain and/or the usual Alabama boundary will intersect the prefrontal trough. That intersection is ahead of (southeast of) the synoptic triple point (TP). Synoptic cold front may have a line of storms as SPC says, and the TP a cluster near the warm front. However the pre-frontal trough and OFB intersection farther south could feature discrete supercells if enough local SRH storm relative helicity. Chart looks like a reasonable initiation of any tornadic cells. Could lumber farther east into Mississippi later. Alabama has lower forecast CAPE - but could get some straight winds Wed. night. Wed. Apr. 13 TOR probs.

Now for today Monday April 11, I have to post this. (See my April 6 follow-up previous page.) Little outside of our Region, but today so classic. Mon. April 11 boundaries for the win! First the black X is probably not severe though near boundaries, where they kind of merge in with a synoptic front. Not a classic intersection though. See MD 446. However some strong storms. Red X is classic outflow intersection with front, aligned right for severe. HRRR goes bonkers with supercells in Arkansas. We'll see. Probably something more in between like ARW / NSSL. NAM seemed underdone. FV3 looks good, more bullish than ARW but not HRRR fest. Despite rising heights, it's gonna go. Very much looks late spring like. Setup is May Plains. Terrain is.. Virtual chase from home, haha!

Wednesday April 6 follow up. Yes @PowellVolz that's my intended message back on Wed. At any rate the northern boundary intersection passed over Chattanooga. As expected, we just got some wind. However it was a little more interesting than I'd expected. First of all, going with a Kansas flag is the only way to go last week! Found my little perch in Chattanooga at US Express, a high spot with a good view. Also where I 1st saw Comet NEOWISE with binoculars. In town, but just doing recon before the dark skies. US Express is a sweet spot, both literally and figuratively in my heart. OK back to Wed. April 6. Then this gets going to my southwest over Lookout Mtn. Thankfully it dissipated without incident, because that's Downtown and other densely populated areas. Look back at radar archive and it had weak rotation. Then to my north a horseshoe cloud forms, sometimes an indicator of rear-flank and possible rotation, but I ignored it for a few minutes. Alas the check of radar archive and it was the better rotation. Not pictured. Think common bow horse shoe. Finally this happens! I gave chase to the horseshoe a little late for proper (aggressive) viewing position. I'm SAFE position with it to my north, but I can't see anything. Wind damage is later reported with the feature between Colledgedale and Ooltewah. I can confirm strong wind from west and small hail. Wed. April 6.

Rock Chalk Jayhawk! Thank you all for the congratulations. It is always special. Setting the record for come-back during the Championship is incredible too. I was out of town last week for kids spring break. Tuesday I was recovering from staying up so late Monday. Hard to sleep after all that excitement, and social media with friends back home. Kansas has been hungry since 2020 was cancelled. Some players remain from 2020. Team dedicated the Championship to players from the 2020 team who graduated. Coach Self also has the personal story. Team rallied around Coach after his dad passed away. Now it's baseball season. NBA and NHL playoffs are soon. Most importantly, it's the heart of Southern chase season. April tends to have better visibility than March. Rock Chalk Jayhawk everywhere!

Wow, I love the enthusiasm in here! Relative to past years this is actually hype. Might yet get some severe wx enthusiasts on the board, haha. Temps have over achieve; so, CAPE is higher than forecast. Dews are as forecast, with the higher temps, which means the LCLs are not particularly low and grungy. MRX may be right that LCLs are favorable.. for chasing. Deep layer shear is there, and the upper levels are stout along I-40. However the LLJ did not report for duty. Probably not a big tornado day.

I'm way behind. Drew up this when Mesoscale Discussion 422 came out. Then got sidetracked. Still worth comparing MD #422 with the old image. More notes below image, but first... However now MD #424 is more relevant to us. Feels like they'll go severe, not tornado watch. SPC put out a tornado watch for that southern boundary intersection. As expected went on gravity wave (yellow) intersection with maritime / yesterday outflow (dark green). Local enhanced SRH is almost Plains like. Our MD 424 is for the intersection of the traditional cool wedge (light green) and pre-frontal trough (light blue). It is more what I look for in the South. However, no LLJ saves Tennessee from much tornado action. I draw the cold front in dark blue, but it's less of a factor. Synoptic warm front is north of Kentucky. All boundaries were cross checked visible satellite and surface chart at the time.

True. Even summer could be tempered for yet another year - in contrast to 1st year Nina. Could we be that lucky? Also a third winter in a row with mild Tropical Pacific SSTs does create a cooler background in the broad Northern Hemisphere Atmo, regardless of MJO behavior. Let's do it! First of all for spring @jaxjagman let's try to hold that +TNI. Should we be careful what we wish for? Or just game on!

Showers percolating in southeast Mississippi are on and south of the Gulf Coast front lifting north, out ahead of the main surface trough and line of storms. Cells could be of interest. Gulf front will continue to lift north into east-central Miss. Main line of storms goes from West Miss into Louisiana. It's linear with QLCS tornadoes probable, and likely poor visibility. The new cells out ahead would perhaps provide better visibility; however, typical South challenges of terrain and trees exist. Also even the cells ahead could get into messy groups or clusters. HRRR is keying in on those southeast Miss cells 15-16Z runs. 12Z NAM missed them. 12Z FV3 was meh small cells. However one of the 12Z ARWs (NSSL research) hinted at the cells becoming rooted southeast Miss. Then going into Bama like the FV3. Latest HRRR runs have some ARW support. One could say the ARW is with HRRR (her). Satellite as of 12:30 Central shows vertical development, and turning with height as the baby anvils shear properly.

Showers percolating in southeast Mississippi are on and south of the Gulf Coast front lifting north, out ahead of the main surface trough and line of storms. Cells could be of interest. Gulf front will continue to lift north into east-central Miss. HRRR is keying in on those southeast Miss cells 15Z run. 12Z NAM missed them. 12Z FV3 was meh small cells. However one of the 12Z ARWs (NSSL research) hinted at the cells becoming rooted southeast Miss. Then going into Bama like the FV3. One could say the ARW is with HRRR (her). PS. I'm sorry I missed the thread for today. However I'll keep this here to follow the HREFs charts above. Satellite as of 12:30 Central shows vertical development, and turning with height as the baby anvils shear properly.

Yeah the GFS is trying to do something mesoscale in southeast Tenn. It could happen somewhere. Thunder would of course promote such totals, but wherever it sets up. Thank your brother's family for us down in Chatty! Though that mesoscale feature is a question, intensity and location, the synoptic setup looks good. Cold, lift and moisture are timed together. We don't have to pray for a trowal on the back side. Instead it'll get cold enough quick enough with the main lift. Last post for the afternoon. Chattanooga members of the board are cautiously optimistic.

Early Congratulations @Knoxtron! Baby previous page. I agree roads will be fine or at least easily passable by Monday. Free for All Friday: MRX refers to kissing jets. I want to make love to the upper level set-up. I was going to say the obligatory last-minute bump-up of snowfall totals. Appears justified this time. Normally I'm skeptical just-in-time cold. However we have key factors. We get classic jet induced / PVA upward vertical motion with thick DGZ. Also the isentropic lift. All juxtaposed with cold and moisture for once around here. NO transfer to the Coast; instead, the back wave (our wave) is the stronger one behind what went through the Carolinas today. Kissing jets is the Carolinas jet-let interacting favorably with what's coming out of the Plains. Areas of lift associated with each jetlet/jet stream interact. Kissing jets is the opposite of what often happens here, where they are out of phase and/or sinking motion of the Coastal nixes the lift. Again that's not a concern. It's fairly easy to model both ways, so the kissing jets carries solid confidence. MRX highlights below. National Weather Service Morristown TN 345 PM EST Fri Mar 11 2022 There is a very high degree of confidence that accumulating snowfall will be seen across the entire forecast area. There is also high confidence that a short period (roughly 2-4 hours) of heavy snowfall rates will be seen. Model plan views show the CWA between two distinct jet structures which will favor strong upward motion. Additionally, cross sections show this deep upward omega along with saturated air extending through the dendritic growth zone and also into regions of negative saturated EPV. All of this supports the idea of high synoptically driven precip rates with the potential for some enhancement via convective processes and resulting 2"/hr snowfall rates. All of this has lead to a broad increase in expected snow accumulations, especially over the central and parts of the southern TN valley, which are locations that should be favorably positioned beneath upper jet structures. That being said, there remains a fair amount of uncertainty in a few areas. Geographically speaking, the southern and far northeastern TN valley are areas of concern. For areas east of I-75 in the southern valley, the question is whether the heavier precip rates will have a long enough residence time over the cold air to result in the higher amounts we`ve put in. Trends have been to support higher amounts so that`s the direction the forecast has gone. In the northeast TN valley, models want to hang on to some warmer temperatures near the surface for a bit longer than other areas, resulting in lower snow amounts relative to areas in the immediate vicinity. This is present in both hires model output as well as courser models like the GFS. Still, the trends have been upward there too. Lastly, going back to the convective element, this could easily lead to some overachieving of storm total snow amounts in places while other locations may be very close or possibly lower than forecast. This is something we simply will not know until we`re in the middle of the event.

Friday free for all. Time to start jawboning Sunday and Monday. Sunday Slight gets into Western Tenn. Flat Arkansas Delta might be the most interesting chaser aspect. Heights are rising though. LLJ ramps up anyway. It's almost like a later spring setup. Monday the Day 4 covers the Region from I-40 south. Inverse of my usual snow commentary, ha. Main system is lifting away, but CAPE and wind shear remain in our warm sector. Lots of college basketball will probably keep me home Sunday. Work would be the problem Monday. Unless it mainly keeps south of Tenn.

My Feb. 23 post above was my last peacetime post. I opined in severe wx yesterday but my attention has been elsewhere. We need the Europe warm 11-15 day forecast to carry forward into the 6-10 day. It will provide policy makers more leeway to strengthen sanctions against Russia even further. No politics rule is not violated hoping for a mild forecast in Europe. It's weather!

Yeah the signal could be there. Also seeing a possible colder 16-20 Day. One has to expect a significant system in the transition. Possible MJO move could support the severe wx pattern; however, it's quite muddled right now. Including tropical cyclones which are wild cards - though not as much so from the Southern Hemisphere.

Seeing Tennessee crush Mizzou is the most satisfying thing this week. Honestly it's more satisfying than Kansas crushing in-state rival KSU. Now you know how Jayhawks feel about Mizzou, haha!

My Kid reports thunder last night. Unfortunately I slept through it. Meanwhile every road in East Brainerd was flooded. Advisory no FF Warning. Two blocks away in Georgia had a Warning. Where was ours? Schools should have delayed 2-hours; but without the warning, decision makers did not act. Total Failure of the Warnings system!

And NO FF WARNING! Two blocks away in Georgia was warned. Hamilton Co. only an advisory. @dwagner88 is that right or did I miss the warning? Every way out of East Brainerd to the Interstater was flooded. However Hamilton Co. schools and private schools business as usual. The one morning we needed a 2-hour delay, nothing was done. This after 4-5 false school closures. Is that on the schools? I would say it's on the NWS. Today was a colossal failure of the warnings system. Mike Smith (infamous on Twitter) mode activated. We need an independent review board! I'm trying to figure out a diplomatic way to email NWS from work. I can't find professional wording at this time.

I see a couple chances along and north of I-40. Still a few weeks to go up there.

Michigan should be disqualified from the Big Dance.

If that's a true Gap near Monterey the one would expect convergence downstream for Maryland and Pleasant Hill. White zone on the chart could also benefit from upslope on the Rim. However the convergence lee of the Gap is probably the bigger driver, at least it appears so by scale and the yellow area. Directional convergence just part of it. Bernoulli Effect should accelerate air through the Gap. Air runs into slower moving air lee side, and more convergence is created. All this is hypotheses based on fluid theory. Wind observations could test and confirm. Microclimates always interest me. Good stuff!

I'm going to resurrect this thread for heavy rain expected next week. Saves the winter thread for any threats of winter precip. Somewhat stationary front will set up over our Region. Several impulses will come out early to midweek. Mostly above freezing, we can focus on flooding threats. Then the main energy brings what could be more severe weather late week. QPF moves with the tracks of the waves. Totals should be robust. Pattern makes it hard to dodge the heavy rain, unless the frontal position shifts markedly.

Thursday kind of surprised in Alabama. I figured the CAPE was more robust in Mississippi; however, the line was also forced. Same east-west boundary sat in Alabama, awaiting the pre-frontal trough. Sure enough the boundary intersection was the epicenter. Notably the FV3 got the scenario day ahead. NAM caught on later.