Friday, March 3, 2023

Tornado Watch

Right now only a small part of this squall line is severe up in Kentucky. But as we get some daylight, that may change. 

The high winds are dangerous in themselves today, apart from any rain or storms. If you live in a mobile home, it is probably better to spend the day with a friend who has a sturdy house, especially if you have trees around it.

The threat for some storms to go severe and produce damaging winds, some hail, and isolated tornadoes is real too. Whether you get a severe thunderstorm warning or a tornado warning as this squall line moves through, you need to get into a small central room (bathroom, closet, or hallway) on the lowest floor of a sturdy house that is not a mobile home. And you might cover your head and neck or otherwise shield your body in case of falling or flying debris. If you do not have a safety helmet, then you might have time to grab a pillow and/or some blankets. 

Don't overthink it today though, just do the basics, because these storms are going to move really fast, maybe at speeds of about 60 miles per hour. And it may be tough to tell what is straight line wind damage and tornado damage until afterward when surveys are done of whatever areas get damage. 

Some of the damage will likely be from just the gradient winds outside of storms with this strong low pressure system. This is a very unusual setup, and the closest thing I know to compare it to is a hurricane moving inland, the kind of strong winds and low-end tornado threat it produces as it is dying out over land. 

That Winfield transmitter is Channel 6 that covers Marion, Lamar, Winston, Walker, and Fayette counties, best I remember. 

7:22 AM - Right now the hot zone to watch is North Central Mississippi. Some storms are gradually intensifying there ahead of the main line. The main threat is damaging winds with any storms, but of course, there is also a threat for a tornado to develop, or this would only be a severe thunderstorm watch. 

7:39 - The storms sure are racing along as expected even if the line itself sort of slowed down on us. Storms within the line are moving quickly northeast. At the moment they are still under severe limits. 

7:57 - Line of storms has crossed I-55 in MS and is starting to organize a little better but for now storms remain under severe limits. Should cross state line into AL within next hour or so. 

8:03 AM - Via latest SPC outlook, we all have a basic damaging wind/isolated tornado threat with this system, but the hatched areas up across the Tennessee border are the most likely places for winds of hurricane force in a storm, or of a tornado developing that can really sustain itself and maybe do a little more than the average damage. So if you are on the TN side maybe be a little extra careful today, but really we all just need a safety plan and to put it into action right away if under a severe thunderstorm or tornado warning later. Or if the weather turns threatening as the line comes through your area. 

8:30 - There was an observed wind gust of 60 miles per hour at the Jackson-Evers International Airport, prompting a severe thunderstorm warning for a whole bunch of counties in Central Mississippi along the leading edge of this line now. 

8:36 - Here's a better look at things. Despite lots of clouds and a few little showers, the air is pretty muggy over Northwest Alabama already. We'll see how much the atmosphere stays capped and if the wind shear defeats its purpose, or if the cap breaks and we get some sustained rotating updrafts.

And yes, power outages are likely. Suddenly I am glad I do have a flashlight, radio that doesn't require juice, and a can opener I use my hands for. Sometimes people watching the weather are not masters of preparing for everything. Stay calm if the power goes out. Main thing today is to stay in a safe place. We got through rolling blackouts at Christmas time when it was so cold.

8:54 - Up in Knoxville their weather radio transmitter is out, so people around there need to make backup plans. The one in Winfield in Alabama is not totally down, just been giving a weak signal lately.

8:58 - And the line is fast approaching Northwest Alabama. Will be interesting to see what the winds are when it comes into the Shoals in next half hour or so.

...and @FlyHSV just gusted to 54 MPH with no storms in the area. Third time over 50 MPH this week. Almost unheard of.

— Jason Simpson (@simpsonWVTM13) March 3, 2023

9:02 AM - The man has a point. Weather has been pretty crazy lately. After today, it does look a lot calmer for the weekend and next week. Just trying to mention a silver lining.

9:09 - Law enforcement has reported an 18-wheeler overturned by high winds near Tupelo, not associated with a thunderstorm.

Just the winds out ahead of the line.

9:12 - And a roof partially taken off an apartment building in Nettleton. 

It might be wise to go ahead and shelter while this line blows through until the winds die down, even if you don't get a severe thunderstorm warning, if you have any doubts as to whether you are safe enough. Remember - small central room or hallway on the lowest floor, away from windows. And of course in a sturdy house, not a mobile home. 

9:14 - And lots of trees down across that county, Lee County MS.

9:19 - Looks like those high winds are estimated just below severe thunderstorm criteria.

9:21 - As the line gets ready to enter Northwest Alabama, the NWS Huntsville reminds people to be ready to take shelter if a warning is issued. And hey, if it makes you feel better, just go ahead and shelter before the line gets to you. It is going to pack some strong winds whether they make it to severe criteria or not. 

9:29 - All right, people from Muscle Shoals down to Town Creek and Phil Campbell need to be heading to shelter now. These storms are moving fast today. 

9:33 - Fayette, Lamar, and Marion counties are now under a severe thunderstorm warning as well as Franklin, Colbert, and Lauderdale, oh and Lawrence, almost forgot. Also saw a tornado warning pop up back across MS border. Sometimes what I see on text data and the radar maps do not update at same time.

9:34 - Since it is not coming up on the radar imagery yet, here is just the warning/watch map. Red is tornado warning, that shade of orange in NW AL is the block of severe thunderstorm warnings.

Yellow is tornado watch, which is covered up by the other brownish shade of orange for much of North AL, the High Wind Warning.

9:39 - Thanks to NWS Birmingham for a decent radar image.

9:44 - Funnel cloud reported in Alcorn County, MS.

9:55 - The tornado warning in Mississippi was let go. But the severe thunderstorm warning in Northwest Alabama (Shoals included) carries a tag that a tornado is possible in the storm, even though the main threat is damaging straight-line winds.

10:08 AM - Two people were injured back in Mooresville MS from this line when a tree fell on a house, said they were unable to evacuate premises.

10:19 - Unfortunately just got a note from SPC that as we continue to get breaks in the clouds and warm up, unstable air will increase the tornado threat as storms move East and we get into the afternoon.

10:21: Many trees down west of Hamilton in Marion County. These storms today mean business.

10:30 - The line moves along. More warnings are coming out . . . 


   Tornado Watch Number 60
   NWS Storm Prediction Center Norman OK
   625 AM CST Fri Mar 3 2023

   The NWS Storm Prediction Center has issued a

   * Tornado Watch for portions of 
     Northwest Alabama
     Far southeast Illinois
     Western into central Kentucky
     Northeast Mississippi
     Western into Middle Tennessee

   * Effective this Friday morning and afternoon from 625 AM until
     100 PM CST.

   * Primary threats include...
     A few tornadoes and a couple intense tornadoes possible
     Scattered damaging winds likely with isolated significant gusts
       to 80 mph possible

   SUMMARY...A fast moving line of storms will intensify and track
   northeast this morning into early afternoon. Damaging gusts and a
   few tornadoes will be the primary hazards with these storms.

   The tornado watch area is approximately along and 85 statute miles
   east and west of a line from 10 miles west northwest of Owensboro KY
   to 40 miles south southeast of Tupelo MS. For a complete depiction
   of the watch see the associated watch outline update (WOUS64 KWNS


   REMEMBER...A Tornado Watch means conditions are favorable for
   tornadoes and severe thunderstorms in and close to the watch
   area. Persons in these areas should be on the lookout for
   threatening weather conditions and listen for later statements
   and possible warnings.



   AVIATION...Tornadoes and a few severe thunderstorms with hail
   surface and aloft to 1 inch. Extreme turbulence and surface wind
   gusts to 70 knots. A few cumulonimbi with maximum tops to 400. Mean
   storm motion vector 22050.

  WOUS64 KWNS 031222

   625 AM CST FRI MAR 3 2023




   COLBERT              CULLMAN             FAYETTE             
   FRANKLIN             LAMAR               LAUDERDALE          
   LAWRENCE             LIMESTONE           MADISON             
   MARION               MORGAN              WALKER              



   HARDIN               MASSAC              POPE                



   BRECKINRIDGE         BUTLER              CALDWELL            
   CALLOWAY             CARLISLE            CHRISTIAN           
   CRITTENDEN           DAVIESS             EDMONSON            
   FULTON               GRAVES              GRAYSON             
   HANCOCK              HENDERSON           HICKMAN             
   HOPKINS              LIVINGSTON          LOGAN               
   LYON                 MARSHALL            MCCRACKEN           
   MCLEAN               MEADE               MUHLENBERG          
   OHIO                 SIMPSON             TODD                
   TRIGG                UNION               WARREN              



   ALCORN               BENTON              CALHOUN             
   CHICKASAW            ITAWAMBA            LAFAYETTE           
   LEE                  MARSHALL            MONROE              
   PONTOTOC             PRENTISS            TIPPAH              
   TISHOMINGO           UNION               YALOBUSHA           



   BEDFORD              BENTON              CARROLL             
   CHEATHAM             CHESTER             CROCKETT            
   DAVIDSON             DECATUR             DICKSON             
   DYER                 FAYETTE             GIBSON              
   GILES                HARDEMAN            HARDIN              
   HAYWOOD              HENDERSON           HENRY               
   HICKMAN              HOUSTON             HUMPHREYS           
   LAWRENCE             LEWIS               LINCOLN             
   MADISON              MARSHALL            MAURY               
   MCNAIRY              MONTGOMERY          OBION               
   PERRY                ROBERTSON           RUTHERFORD          
   STEWART              SUMNER              WAYNE               
   WEAKLEY              WILLIAMSON          WILSON              


Here we go . . . details soon.

Coming soon . . . 


Mesoscale Discussion 0242

   NWS Storm Prediction Center Norman OK

   0401 AM CST Fri Mar 03 2023

   Areas affected...portions of northern MS/AL...western into Middle

   TN...western KY...far southeast MO...and far southern IL

   Concerning...Severe potential...Watch likely 

   Valid 031001Z - 031230Z

   Probability of Watch Issuance...80 percent

   SUMMARY...A new tornado watch will likely be needed by 13-14z/7-8 am

   CST across portions of the Tennessee and Lower Ohio Valleys.

   Damaging gusts and a few tornadoes will be possible through

   midday/early afternoon.

   DISCUSSION...A quasi-stationary boundary is evident in surface

   analysis extending from west-central TN toward the TN/KY border

   vicinity north of Nashville. Meanwhile, the warm front, demarcating

   mid-60s F surface dewpoints from upper 50s to low 60s F dewpoints,

   is arcing from near Memphis into east-central MS (between Starkville

   and Tupelo) and central AL. Large-scale ascent ejecting into east

   TX, as the mid/upper trough becomes more negatively tilted as of

   10z, will aid in deepening of the surface low over central AR as it

   tracks northeast toward the Lower OH Valley through midday. As this

   occurs, the warm front will lift northward, allowing for

   destabilization of the airmass downstream from WW 59 across parts of

   northern MS into western and Middle TN, and eventually northward

   toward the lower OH River. 

   Ongoing precipitation across parts of western/Middle TN/southeast

   MO/western KY and vicinity lends to some uncertainty with respect to

   the northern extent of severe potential through the morning, and

   possible watch issuance. While a relative minimum in severe activity

   may exist in the short term, as the warm front surges northward

   through mid-morning, forecast soundings in addition to CAMs and

   deterministic guidance suggest organized convection will develop

   northeast from near the MS River through western KY.

   Where the more moist and unstable airmass evolves, sufficient

   low-level instability, in the presence of intense low-level shear

   (aided by a 50-60 kt 850 mb jet), will support organized linear

   convection with perhaps embedded or semi-discrete cells. Damaging

   gusts and a few tornadoes will be possible with this activity

   through midday/early afternoon. A downstream watch will likely be

   needed by around 13z-14z.

   ..Leitman/Edwards.. 03/03/2023

   ...Please see for graphic product...


   LAT...LON   36008974 36938956 37368926 37688873 37868807 37918734

               37868678 37748655 37208638 36328636 35068661 34518683

               34178714 33848781 33598840 33638940 33788978 34038992


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