jaxjagman Posted December 31, 2021 Share Posted December 31, 2021 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CST Fri Dec 31 2021 Valid 011200Z - 021200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE DEEP SOUTH AND TENNESSEE VALLEY.... ...SUMMARY... Widespread thunderstorms are expected from the ArkLaTex to the Western Appalachians on New Year's Day. All severe-weather hazards are possible including large hail, damaging winds, and tornadoes, a couple of which may be strong. ...Synopsis... A positively tilted upper-level trough will be centered near the Great Basin to start the period. This trough will maintain its positive tilt as it shifts eastward across the Plains and into the Midwest by 12Z Sunday. An embedded mid-level shortwave trough will move quickly from the southern High Plains across the Midwest and Ohio Valley Saturday to the Northeast by Sunday morning. A surface reflection of this mid-level shortwave trough is expected to travel along the front from the Ozarks to the Ohio Valley and into the Mid-Atlantic. ...Ohio Valley into the central Appalachians... There is still considerable uncertainty regarding the northward extent of the destabilization and severe-weather threat based on the position of the position of the surface front and the strength of the surface low. The NAM is stronger with the surface low with a much farther north warm front bringing low 60s dewpoints north of the Ohio River into southern Illinois, southern Indiana, and Southwest Ohio. However, the operational GFS is much weaker and southeast with the surface low and only brings low 60s dewpoints into south-central Kentucky. The ECMWF solution is between these two locations with the frontal position, which also closely resembles the GEFS mean. Therefore, the northern extent of the marginal and slight risk threat areas match the ECMWF and GEFS mean. A line of storms is expected to move through this region during the afternoon and early evening hours. Forecast soundings show more than 50 knots of flow only a few hundred meters above the surface. Therefore, mixing this strong flow to the surface should not be that difficult, even in a weak buoyancy environment. Low 60s dewpoints should yield MLCAPE around 250 to 500 J/kg across southern Kentucky, which increases the confidence for severe winds as the squall line moves through. In addition, a QLCS tornado threat will exist given the strong low-level speed shear present ahead of this line of storms. However, the limited instability and veered surface flow will be limiting factors to a greater tornado threat along this portion of the line. ...Portions of the Deep South into the Tennessee Valley... A large area of thunderstorms, some of which may be severe, is expected to be ongoing from western Kentucky to northern Texas Saturday morning. As the surface low moves from the Plains into the Ozarks Saturday morning, this convection is expected to become better organized, likely into a squall line, and start to advance eastward. Dewpoints are forecast in the mid to upper 60s ahead of these storms, which should yield MLCAPE around 500 to 1500 J/kg from north to south. This should be more than sufficient to maintain a strong squall line through the afternoon and into the overnight hours across eastern Arkansas, most of Tennessee, and northern Mississippi and Alabama. A 50 to 60 knot low-level jet will result in strong low-level speed shear across the entire warm sector. Forecast soundings show mostly unidirectional flow in the lowest 1 km due to the veered surface flow across most of the warm sector as a result of the elongated nature of the surface pressure pattern. This should temper the tornado threat somewhat, but with the strong speed shear and the expectation of a well balanced squall line, the environment will still be supportive for QLCS tornadoes. Most guidance hints at the potential for some warm sector supercell development across portions of Mississippi, Alabama, and Tennessee Saturday afternoon/evening. The ECMWF has been especially bullish with pre-frontal convection for the last several days, which continues through the latest 00Z run. Any strong supercells which can develop in the open warm sector will likely have the greatest threat for significant to potentially intense tornadoes. The most likely region for pre-frontal supercell development will be from eastern Arkansas to northern Alabama and possibly southern Tennessee where greater instability is forecast. Veered low-level flow will keep low-level directional shear limited during the first half of the day. However, at least slightly greater low-level turning is shown by forecast soundings during the late afternoon into the evening hours as surface flow remains south-southwest, while the low-level jet starts to veer more westerly as the main wave shifts east. This may result in a slightly higher tornado threat into the overnight hours from far eastern Mississippi into northern/central Alabama and northwest Georgia. ..Bentley.. 12/31/2021 Link to comment Share on other sites More sharing options...
jaxjagman Posted December 31, 2021 Author Share Posted December 31, 2021 We had to replace our roof the last storm,meant to post it on the last severe thread but its locked now 1 3 Link to comment Share on other sites More sharing options...
nrgjeff Posted December 31, 2021 Share Posted December 31, 2021 Saturday will depend on the prefrontal trough. Main front is veered off with parallel upper level flow, not really a tornado machine. Mississippi and Alabama will start Saturday capped. However the cap will gradually erode. Prefrontal trough is forecast and will be there. Question is the cap. If the cap breaks down there, discrete supercells will bring their usual threats. They would probably go from rooted to tornado in an hour. That kind of shear, this time with low level flow, would spin up tornadoes rapidly. Would be MDT but too early to make the call now. That's only if the cap breaks. If the cap holds then it'll look a lot like Wednesday - which still had Sand Mountain tornado(es). However that's not a huge day across the region. SPC should hold with ENH on this afternoon's Day 2. 2 1 Link to comment Share on other sites More sharing options...
Windspeed Posted December 31, 2021 Share Posted December 31, 2021 Saturday will depend on the prefrontal trough. Main front is veered off with parallel upper level flow, not really a tornado machine. Mississippi and Alabama will start Saturday capped. However the cap will gradually erode. Prefrontal trough is forecast and will be there. Question is the cap. If the cap breaks down there, discrete supercells will bring their usual threats. They would probably go from rooted to tornado in an hour. That kind of shear, this time with low level flow, would spin up tornadoes rapidly. Would be MDT but too early to make the call now. That's only if the cap breaks. If the cap holds then it'll look a lot like Wednesday - which still had Sand Mountain tornado(es). However that's not a huge day across the region. SPC should hold with ENH on this afternoon's Day 2.This just came out but obviously with the caveats if/will supercells fire in the warm sector. If so it could be a bad evening. 1 1 Link to comment Share on other sites More sharing options...
John1122 Posted December 31, 2021 Share Posted December 31, 2021 Spent part of the day in NE Alabama. Thickly humid there and upper 60s. Lots of rain showers off and on. Not sure how that may affect instability, if that even matters in this case. I assume tomorrow would be the biggest potential. 1 Link to comment Share on other sites More sharing options...
jaxjagman Posted January 1, 2022 Author Share Posted January 1, 2022 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0636 AM CST Sat Jan 01 2022 Valid 011300Z - 021200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH EARLY TONIGHT ACROSS THE TN VALLEY... ...SUMMARY... Damaging winds and tornadoes, a couple of which could be strong, will be possible through early tonight, especially across the Tennessee Valley. ...TN Valley and vicinity through tonight... Convection has persisted through the early morning hours along a baroclinic zone demarcating the northwest edge of the richer low-level moisture from AR into TN/KY. The convection has reinforced this boundary and it is unlikely to return northward today, given the lack of strong cyclogenesis as a result of an expansive cold air mass across the central U.S. that will undercut the stronger forcing for ascent in advance of the primary shortwave trough over AZ/UT this morning. Even though the main surface cyclone will not be particularly intense and will develop farther northeast away from the warm sector (in tandem with an ejecting shortwave trough now over TX/OK), strong deep-layer wind fields and vertical shear will persist through the day and into tonight in the warm sector across the TN Valley. Given the persistence of the subtropical ridge over FL and only glancing/small height falls through the day, much of the convection may remain confined to the convection-reinforced frontal zone. Still, there will be the potential for embedded supercells within a broken band of storms along the front, and a lower chance for a couple of supercells in the open warm sector along diffuse confluence zones a little south of the front this afternoon/evening. Effective bulk shear of 60-70 kt, effective SRH near 300 m2/s2, and MLCAPE of 500-1500 J/kg will conditionally support supercells capable of producing tornadoes, damaging winds, and marginally severe hail. The prospects for a strong tornado or two will likely hinge on pre-frontal supercell development (which is uncertain) from northern MS into northern AL and TN late this afternoon/evening. The frontal convection will spread southeastward through the overnight hours, with a gradually lessening severe threat and shrinking warm sector centered on AL toward the end of the period. ..Thompson/Kerr.. 01/01/2022 Link to comment Share on other sites More sharing options...
Windspeed Posted January 1, 2022 Share Posted January 1, 2022 Link to comment Share on other sites More sharing options...
Utvols235 Posted January 1, 2022 Share Posted January 1, 2022 Off and on sun in Red Bank. 73 degrees. Dew point at 65. Link to comment Share on other sites More sharing options...
jaxjagman Posted January 1, 2022 Author Share Posted January 1, 2022 Tornado in KY has some decent rotation now Link to comment Share on other sites More sharing options...
jaxjagman Posted January 1, 2022 Author Share Posted January 1, 2022 Almost a 2 on trot Link to comment Share on other sites More sharing options...
VOLtage Posted January 1, 2022 Share Posted January 1, 2022 Kind of worried about a more discrete storm mode with the initial line of storms. Link to comment Share on other sites More sharing options...
jaxjagman Posted January 1, 2022 Author Share Posted January 1, 2022 Not much convection at all,some quick rotation then it dies off just as fast Link to comment Share on other sites More sharing options...
jaxjagman Posted January 1, 2022 Author Share Posted January 1, 2022 URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 3 NWS Storm Prediction Center Norman OK 1050 AM CST Sat Jan 1 2022 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of South-central Kentucky Western to middle Tennessee * Effective this Saturday morning and evening from 1050 AM until 600 PM CST. * Primary threats include... A few tornadoes likely with a couple intense tornadoes possible Scattered damaging winds likely with isolated significant gusts to 75 mph possible SUMMARY...An intensifying squall line should spread east-northeast with a threat for damaging winds and embedded tornadoes. A couple pre-frontal supercells may develop as well with the possibility of a strong tornado. The tornado watch area is approximately along and 60 statute miles east and west of a line from 90 miles east northeast of Bowling Green KY to 35 miles south southeast of Jackson TN. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU3). 2 Link to comment Share on other sites More sharing options...
*Flash* Posted January 1, 2022 Share Posted January 1, 2022 34 minutes ago, jaxjagman said: Not much convection at all,some quick rotation then it dies off just as fast Indicative of a cap not yet broken...or so it sounds. You think that trend will hold? Link to comment Share on other sites More sharing options...
jaxjagman Posted January 1, 2022 Author Share Posted January 1, 2022 11 minutes ago, *Flash* said: Indicative of a cap not yet broken...or so it sounds. You think that trend will hold? yeah,warm above,starting to see lightning now Link to comment Share on other sites More sharing options...
jaxjagman Posted January 1, 2022 Author Share Posted January 1, 2022 Confirmed tornado in KY,wiped out a grain silo,fwiw 1 Link to comment Share on other sites More sharing options...
brianc33710 Posted January 1, 2022 Share Posted January 1, 2022 Bham temp 77 dewpoint 70 on NYD!?!? This would be impressive for even Tampa Bay in January! 2 Link to comment Share on other sites More sharing options...
jaxjagman Posted January 1, 2022 Author Share Posted January 1, 2022 Some weak rotation NE of Centerville Link to comment Share on other sites More sharing options...
jaxjagman Posted January 1, 2022 Author Share Posted January 1, 2022 getting better Link to comment Share on other sites More sharing options...
jaxjagman Posted January 1, 2022 Author Share Posted January 1, 2022 Tornado south of Bald springs Link to comment Share on other sites More sharing options...
VOLtage Posted January 1, 2022 Share Posted January 1, 2022 Nashville is in the crosshairs of that tornado warned storm. Link to comment Share on other sites More sharing options...
jaxjagman Posted January 1, 2022 Author Share Posted January 1, 2022 7 minutes ago, VOLtage said: Nashville is in the crosshairs of that tornado warned storm. Not very strong rotation now Link to comment Share on other sites More sharing options...
jaxjagman Posted January 1, 2022 Author Share Posted January 1, 2022 Storm headed towards Centerville might get warned real soon Link to comment Share on other sites More sharing options...
Santa Clause Posted January 1, 2022 Share Posted January 1, 2022 Storm mode looks to hold back on outbreak possibly. Link to comment Share on other sites More sharing options...
VOLtage Posted January 1, 2022 Share Posted January 1, 2022 Mesoscale Discussion 0008 NWS Storm Prediction Center Norman OK 1238 PM CST Sat Jan 01 2022 Areas affected...Central KY...Middle TN...Northern AL Concerning...Tornado Watch 3... Valid 011838Z - 012015Z The severe weather threat for Tornado Watch 3 continues. SUMMARY...Threat for damaging wind gust and tornadoes continues across central KY and middle TN within Tornado Watch 3. This threat will persist downstream into more of central KY, middle TN, and northern AL, where a watch will likely be needed. DISCUSSION...Recent observations place the outflow boundary from about 20 miles south of LEX southwestward to just southeast of BWG, continuing southeastward through western TN to about 20 miles southeast of MEM. Numerous shallow but strong/organized cells have developed along this outflow boundary and lightning has become slightly more frequent over the last hour. General trend with the stronger storms developing within the line is for an initially cell-in-line structure with a strong, more organized updraft. This more cellular structure then relatively quickly trends towards bowing line segments as the outflow boundary continues pushing southeastward. As such, a relatively brief period for tornadogenesis exists before the storms then transition to more of a damaging wind threat. Initial, more discrete development has also occurred sporadically ahead of the line, with a longer duration of more cellular structure contributing to a slightly greater tornado risk. These storms also trend towards bowing line segments as the outflow overtakes them. This overall pattern is expected to continue for at least the next few hours as the outflow pushes quickly eastward/southeastward. Current motion places the outflow near the edge of Tornado Watch 3 by 1930Z-2000Z. Winds are currently a bit more veered downstream, but vertical shear remains very strong. As such, supercells capable of damaging wind gusts and tornadoes remain possible and a downstream watch will likely be needed. Link to comment Share on other sites More sharing options...
Amped Posted January 1, 2022 Share Posted January 1, 2022 5 minutes ago, Wmsptwx said: Storm mode looks to hold back on outbreak possibly. There is a lot of discrete stuff ahead of the line extending all the way to the gulf coast. Link to comment Share on other sites More sharing options...
jaxjagman Posted January 1, 2022 Author Share Posted January 1, 2022 3 minutes ago, Amped said: There is a lot of discrete stuff ahead of the line extending all the way to the gulf coast. agree Link to comment Share on other sites More sharing options...
jaxjagman Posted January 1, 2022 Author Share Posted January 1, 2022 sirens going off here Link to comment Share on other sites More sharing options...
jaxjagman Posted January 1, 2022 Author Share Posted January 1, 2022 nrot is 2.5 for that cell tpwards Fairview Link to comment Share on other sites More sharing options...
jaxjagman Posted January 1, 2022 Author Share Posted January 1, 2022 best cell right now is north of Fairwiew 1 Link to comment Share on other sites More sharing options...
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