nrgjeff

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.

I forgot to comment on the big Tennessee win! Vols avenged the Rupp ruckus. When Tennessee plays with energy the defense creates offense. We'll see how things go into March. As of Arks, yeah the extended range looks wet. Most of it is above freezing in contrast to the ice crap progged a couple days ago. Oh the Knoxville article. Regardless of which side one is on the climate debate (another Forum section) a warmer climate with longer growing season is considered beneficial to humanity thanks to food production. Nets drought impacts with longer growing season where moisture is adequate.

Cold starting late next week into the 26th weekend has support from the Yukon block @Carvers Gap that's a good description. However I'm not sure how long it'll last. It's been cold-ish for six weeks now.

Mississippi I have more confidence in on Thursday. Surface temps should hit 70 degrees with 65 dews. Prefrontal trough will slam into that environment. Alabama will depend on how the warm front behaves. Midday rain would keep it stable. Morning rain lifting into Tennessee would open Alabama to outflow. Little if any rain would leave the warm front, but still surface heating questions. No rain would leave a stratus deck in tact. Stratus is pattern recognition early season warm 850 Ts. Bottom Line: Alabama has two paths to keeping stable and only one path to severe. Mississippi is probably reverse, a 2/3 chance of severe.

If it can happen in the Plains in early March, Hesston KS Mar. 13, 1990 it certainly happens in the South. That day in March 2012 was prolific on a national scale. This (Saturday) morning SPC expanded the Thursday 15% east to the Alabama Georgia line. Gets into the Lower Plateau as well. As for the MJO, we got a buffet line of convection going into the Maritime Continent. -PNA is indeed activated.

Perhaps we can test the TIMS enhanced version. Tornado watches bring even more snow the next system. For those who get anxious about severe wx I'm just jawboning. Day 7 might as well be day 124.

Saturday snow is canceled for southeast Tenn. I'm now much more interested in Thursday severe Mid South. Maybe it'll TIMS after that, haha!

Vols got a nice road win! Do we have a snow index for that? Also we need a rave glowsticks reaction. Really good news such as.. Garden thread going means spring is coming!

Yeah they might want to ask Memphis truck drivers about that, lol! Models could have been better overnight. Southeast Tenn gonna need more @John1122 Feb 2014 vibes. That one got us.