Live Blog: Tornado Outbreak Continuous Coverage

Severe Weather Outlook 1

This live blog provides a one-stop shop for our users to get the latest forecasts during the current tornado outbreak. In addition to descriptive graphics, we will also share footage as this event unfolds, along with periodic forecast discussions.

Update: Wednesday, March 17, 2021 at 6:08pm ET (5:08pm CT)
Update: Wednesday, March 17, 2021 at 6:04pm ET (5:04pm CT)

A dangerous tornado is currently passing across I-65, north of Birmingham, between Gardendale and Morris.

Update: Wednesday, March 17, 2021 at 5:04pm ET (4:04pm CT)

As of 3:58pm CT, a confirmed tornado was located near Bull City, moving northeast at 30 mph. This tornado-producing storm will soon begin in infringe on northwestern portions of the Birmingham metro region.

Confirmed tornado heading northeastward toward northwestern portions of the Birmingham, Alabama metro.
Update: Wednesday, March 17, 2021 at 4:43pm ET (3:43pm CT)

That blue dot on the right image indicates that debris is being lofted into the atmosphere by a strong tornado. This is the tornado that was near Brookwood, Alabama around 3:31 pm CT. It’s moving northeast at 20 mph. Radar imagery shared by chief meteorologist Marc Weinberg.

Update: Wednesday, March 17, 2021 at 4:33pm ET (3:33pm CT)

Extensive tornado damage over chicken houses in Wayne County, Mississippi from earlier this afternoon. Photo shared by Brian Emfinger (@brianemfinger on Twitter)

Update: Wednesday, March 17, 2021 at 4:12pm ET (3:12pm CT)

A confirmed and strong tornado remains on the ground with a storm that is now east of downtown Tuscaloosa, Alabama. The tornado is now just north of I-20, moving northeastward toward Brookwood.

Strong tornado moving in Tuscaloosa County, Alabama
Update: Wednesday, March 17, 2021 at 3:54pm ET (2:54pm CT)

A confirmed large and extremely dangerous tornado is 7 miles south of Tuscaloosa, Alabama as of 2:45pm CT. The storm is moving northeast at 30 mph. The National Weather Service has designated this as a particularly dangerous situation.

Radar over Tuscaloosa, Alabama as of 2:50pm CT
Strong velocity couplet on Radar southeast of Tuscaloosa as of 2:53pm CT
Update: Wednesday, March 17, 2021 at 3:40pm ET (2:40pm CT)

Clusters of supercells continue to head northeastward across the outlined region. Though surface temperatures may be slightly lower relative to areas nearby, vertical wind shear is very favorable for strong, potentially long-track tornadoes.

Latest region favorable for strong tornadoes in the near future.
Update: Wednesday, March 17, 2021 at 2:30pm ET (1:30pm CT)
tornado watch for western mississippi, southeastern Arkansas, and northern and northeast Louisiana until 7pm CT.
PDS tornado watch for much of western MS and across parts of northern/northeastern LA and southeastern AR until 7pm CT
Update: Wednesday, March 17, 2021 at 2:22pm ET (1:22pm CT)

The SPC has outlined a region across south-central Mississippi that has rapidly become favorable for the development of strong tornadoes.

Update: Wednesday, March 17, 2021 at 2:16pm ET (1:16pm CT)

From earlier in Wayne County, MS. . .

Update: Wednesday, March 17, 2021 at 1:43pm ET (12:43pm CT)

Another PDS tornado will shortly be issued across parts of western Mississippi, southeastern Arkansas, and northeastern/eastern Louisiana.

Outlined region expected to go under PDS tornado watch shortly.
Update: Wednesday, March 17, 2021 at 1:33pm ET (12:33pm CT)

Analogs indicate strong tornado potentially ongoing in Mississippi currently.

Update: Wednesday, March 17, 2021 at 1:27pm ET (12:27pm CT)

A confirmed tornado has already been detected 10 miles south of Goodwater, Mississippi and will cross over the Mississippi/Alabama state line. The Storm Prediction Center has outlined a region that could face impacts from a strong tornado within the next 1-2 hours or less.

Strong tornado threat exists across parts of the MS/AL border
Update: Wednesday, March 17, 2021 at 12:47pm ET (11:47pm CT)

A PDS tornado watch has now gone live across parts of Mississippi and Alabama until 7pm CT. We will make a better graphic in a bit.

A PDS tornado watch has gone live across parts of Mississippi and Alabama until 7pm CT.
Update: Wednesday, March 17, 2021 at 12:40pm ET (11:40pm CT)

Parts of Mississippi and Alabama now sit under a rare 45% tornado risk. These high probabilities have only been used a handful of times in the past. This means that there’s a 45% chance that a tornado will hit within 25 miles of a given point within the outlined region.

The probability that a tornado will hit within 25 miles of a given point in the outlined regions.
Update: Wednesday, March 17, 2021 at 12:20pm ET (11:20pm CT)

The Storm Prediction will issue a PDS (particularly dangerous situation) tornado watch shortly across parts of Mississippi and Alabama. Breaks in cloud coverage, along with strong, low-level transport of moist air from the Gulf of Mexico, have quickly allowed for the atmosphere to become unstable. Temperatures have already surged well into the 70s to near 80 across central and southern Mississippi.

PDS tornado watch coming shortly for outlined region
Breaks in cloud coverage have allowed for quick destabilization.
Update: Wednesday, March 17, 2021 at 12:00pm ET (11:00pm CT)
Severe weather outlook for Wednesday, March 17.
Severe weather outlook for Thursday, March 18.

Significant severe weather outbreak possible Saturday

Forecast Discussion: A strong shortwave is currently sweeping across the Four Corners region, which has induced the development of a surface low pressure system over the southeast Colorado/northeast New Mexico border. As the strong shortwave closes off into a mid-level low pressure system, the surface low will move into southwestern Kansas over the next few hours. A frontal boundary is currently stalled out across central Missouri, lower Illinois/Indiana and along the Ohio River in Ohio/Kentucky. A very moist environment exists south of the frontal boundary at and near the surface. As the surface low treks across Kansas tonight and tomorrow morning and into Missouri/Iowa late Saturday afternoon, the stalled front will begin moving northward as a warm front, replacing the dry airmass to its north with moisture-laden air. Throughout the day Saturday, surface dew points will increase across southeast Iowa and over the remainder of Illinois, Indiana, and Ohio.

surface analysis

Isentropic lift occurs when warmer air pushes up and over a colder airmass, which can generate precipitation. Isentropic lift, along with embedded weaker shortwaves, will continue to generate rainfall along and north of the soon-to-be warm front tonight into tomorrow morning across much of the lower Midwest. If you take a look at the Storm Prediction Center’s (SPC) severe weather risk area for Saturday, they have an enhanced and moderate risks extending from far northeast Missouri and southeast Iowa into northern/central Illinois, and northwestern Indiana. Please be aware that conditions in the morning (6-8am CT) may not feel like a severe weather day across the enhanced/moderate risk areas. Since the warm front will have not moved through much of the region at this point, temperatures will be somewhat chilly, especially with the rain falling. However, as the warm front surges northward, low-level moisture (humidity levels) will increase rapidly into the afternoon hours.

severe weather forecast

The surface low will move into western Iowa by mid-afternoon, strengthening further as it moves into the region. The region positioned just east of the surface low, ahead of the cold front, and south of the warm front will have the greatest risk of dangerous severe weather, as outlined in the SPC forecast. Rainy weather in the morning hours should move out quickly enough to allow for sufficient daytime heating at the surface. As the mid-level low approaches from the west, mid-level temperatures will cool, which will increase instability within the atmosphere. Surface-based instability allows air parcels (bubbles of air) near the surface and within the low levels of the atmosphere to begin rising. Surface heating and the addition of moisture makes those low-level air parcels buoyant. By cooling the mid-levels of the atmosphere, this ensures that the rising air parcels will remain warmer than the surrounding environment, allowing them to keep rising. This strong rising motion in the atmosphere on Saturday will result in deep thunderstorms developing across the risk zone, which will cause an increased risk for very large hail.

Tornado Risk: The enhanced and moderate risks also have been issued due to the tornado risk tomorrow. Within the treat zone, winds will flow from the southeast at the surface but will veer to the southwest with increasing height. We call this vertical wind shear. The position of the surface low relative to the mid-level low and shortwave will cause this turning of the winds with height. Given higher instability and vertical wind shear, tornadoes, some of which could be EF-2 or stronger, are expected. In fact, long-track tornadoes are possible. Keep in mind that the tornado risk extends southward into the Mississippi Valley ahead of the cold front as well; however, the tornado probabilities across that region will stay comparatively lower.

Chicago Tornado/Hail Risk: You might notice that the SPC only has Chicago under a slight risk; however, residents should watch the forecast closely tomorrow afternoon into the evening. The 18z NAM model is slower with moisture return across the Chicago area. By 5pm CT, the model projects dew points to only be in the mid to upper 40s. To the contrary, the HRRR model guidance has consistently projected dew points to be in the upper 50s or 60°F around the same time in downtown Chicago and well into the 60s in the western and southern metro. Timing matters a lot. If the low levels moisten sooner in Chicago, this could increase the tornado risk across the city, especially in the western and southern metro. Which model do we pick? That’s a tough question, especially when they’re trying to iron out intricate details. From what I can tell, the NAM model keeps conditions a bit cloudier across northern Illinois into the afternoon and even has storms moving through a little earlier than the HRRR model does. On the other hand, the HRRR has more daytime heating across the area, which would likely allow the warm front to advance northward more quickly. In effect, this would give developing and passing storms a much more unstable environment to work with. Honestly, I wouldn’t be surprised if the SPC bumps up the risk across areas closer to Chicago in their next update.

NAM model dew points
HRRR model dew points

Please continue to monitor the situation closely throughout the day tomorrow. These forecasts are never perfect, which means that you should expect some forecast modifications tonight and tomorrow morning.  

Two-Day Severe Weather Event Including A Tornado Risk

Saturday-Early Sunday Morning: A strong shortwave system currently located over the Four Corners region has contributed to the development of a surface low pressure system over Mexico. As the shortwave advances eastward, the surface low will move northeastward across Texas tomorrow. By mid-afternoon, the low should be east of Dallas, TX, and by the evening, the system will begin moving across Louisiana/Arkansas. Widespread moderate rainfall will accompany this low across western Texas and across most of Oklahoma, but the primary concern for a potentially significant severe weather event is farther east into eastern Texas, northern Louisiana, southern Arkansas, and west-central Mississippi. Later into Saturday evening and early Sunday morning, the severe weather threat should continue across central-eastern Mississippi.

Aside from the light to moderate rainfall moving across northeast Louisiana and west-central Mississippi this evening, conditions across much of the Mid-South are quite pleasant. A frontal boundary associated with the previous storm system that dumped high snowfall amounts across the Plains and Upper Midwest is currently draped across the lower Mid-South. Since the frontal boundary never really had the opportunity to move well off the Gulf Coast, it won’t take much time for the low-level atmosphere to moisten as the surface low advances eastward over Texas. Dew points are only in the 40s and 50s across eastern Texas, northern Louisiana, and southern Arkansas this evening, but southerly/southeasterly winds will help bring dew points back into the upper 60s and 70s by tomorrow afternoon. Sufficient low-level moisture is a necessary ingredient for severe weather to occur.

Projected dew points on Saturday afternoon

Sometimes, morning thunderstorms and rainfall can help limit a severe weather risk if the atmosphere does not have adequate time to recover and become unstable. However, this should not be an issue tomorrow. Most of the widespread rainfall will remain mainly west of the Midsouth, and if morning activity develops across the region, it should remain scattered enough that plenty of daytime heating will still occur. Since the mid-level environmental temperatures will be quite cold (something that will actually contribute to more instability), temperatures around 70°F should be sufficient for moderate instability.

Projected radar for Saturday afternoon

Given sufficient instability and favorable wind shear profiles, a tornado risk exists across eastern Texas, northern Louisiana, southern Arkansas, and west-central Mississippi. Some tornadoes could be strong. Additionally, large hail and damaging winds will cause issues. The Storm Prediction Center has included a moderate and enhanced risk across those areas. If you are the risk zone, please plan accordingly, and ensure that you have a place to take shelter if a tornado hits your hometown.

Saturday severe weather outlook from the SPC

Sunday-Sunday Evening: The surface low will continue advancing northeastward on Sunday and eventually move across the Ohio Valley. Given this track, a broad and elongated severe weather risk will exist across a large part of the Southeast and extend into the lower Ohio Valley. The Storm Prediction Center has placed an enhanced severe weather risk from Alabama and Georgia northward into southern Ohio. A squall line will eventually develop and move eastward later Sunday or early Monday morning just ahead of an advancing cold front. Though the squall line will primarily pose a damaging wind risk with isolated tornadoes, the bigger tornado threat will exist ahead of the squall line during the day on Sunday, where thunderstorms could be more discrete. Comparatively, the tornado threat may not be as high as on Saturday; however, sufficient instability and wind shear should favor the development of tornadoes across parts of the slight and enhanced regions on Sunday. I will provide a follow-up update for the Southeast tomorrow evening. After monitoring how everything evolves tomorrow and tomorrow night, I expect I will have to make some modifications on the magnitude of the Sunday tornado risk. As suggested above, please have a plan in place.

Sunday severe weather outlook from the SPC
Tornado sheltering guidelines recommended by FEMA

-Meteorologist Matthew Holliday

Tornado Outbreak expected in Southeast

A significant Tornado outbreak and Severe Thunderstorm outbreak is expected across many areas in the Southeast, from Florida back into Alabama up through Georgia, South Carolina and parts of North Carolina.    The biggest risk is from northern Florida into Southern Georgia with smaller risks as far west as Eastern Mississippi up into Southern Virginia.

Tornado Outbreak forecast

Significant Severe Tornadoes expected

Tornado Outbreak
Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SIG SEVERE 95,336 13,200,743 Columbia, SC…Charleston, SC…

St. Petersburg, FL…Orlando, FL…

Savannah, GA…Gainsville, FL

30 % 52,311 4,824,800 Jacksonville, FL…Tallahassee, FL…

Savannah, GA…Gainesville, FL…

Albany, GA…

15 % 44,337 9,370,344 Tampa, FL…St. Petersburg, FL…

Columbia, SC…Clearwater, FL…

Charleston, SC…

10 % 42,022 5,926,863 Orlando, FL…Columbus, GA…

Fayetteville, NC…Wilmington, NC…

Lakeland, FL…

5 % 81,803 21,852,295 Charlotte, NC…Atlanta, GA…

Miami, FL…Raleigh, NC…

Greensboro, NC…

2 % 48,102 6,722,417 Virginia Beach, VA…Norfolk, VA…

Birmingham, AL…Chesapeake, VA…

Winston-Salem, NC…

High Risk issued for Severe Weather

Categorical Day1 1300Z Outlook
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
HIGH 52,325 4,828,034 Jacksonville, FL…Tallahassee, FL…

Savannah, GA…Gainesville, FL…

Albany, GA…

MODERATE 44,236 9,345,964 Tampa, FL…St. Petersburg, FL…

Columbia, SC…Clearwater, FL…

Charleston, SC…

ENHANCED 54,540 8,455,690 Orlando, FL…Columbus, GA…

Cape Coral, FL…Fayetteville, NC…

Port St. Lucie, FL…

SLIGHT 68,779 19,272,935 Charlotte, NC…Atlanta, GA…

Miami, FL…Raleigh, NC…

Greensboro, NC…

MARGINAL 58,080 13,692,306  

Virginia Beach, VA….

Norfolk, VA…

 

 

 

 

 

 

 

 

 

A strengthening mid and upper level trough currently over Texas and Oklahoma will shift eastward into Mississippi and Alabama by this afternoon with a cold front surging east from Louisiana and Mississippi.    This storm will deepen and move north-northeastward across Alabama and Georgia.  Dewpoints ahead of this cold front are already in the 65 to 70 degree range with very buoyant air present.  The net result of these factors will be the potential for a significant tornado outbreak today.

Severe Weather is currently taking place across parts of Alabama, Georgia and Florida and a Tornado Watch is in effect until 10 AM EST.  Cluster of severe storms remain from the overnight hours and the storm environment remains favorable for supercell development.  A few tornadoes are likely and they could be intense.  Damaging winds and Large hail are also possible with these storms.

Additional watches should be expected during the day today.

While the current storms across Georgia are present, the main risk does not occur until later this morning, when thunderstorm activity will begin again over Southern Alabama and the Florida panhandle.  These storms will the spread east-northeast across Florida and Georgia through the day.  Long tracked, strong tornadoes will be possible in fast moving supercells, in addition to damaging winds and large to very large hail.  The severe risk will spread northeastward into the Carolinas this evening as the system moves toward the Southern Appalachians.  Tornadic supercells could continue to occur in south Carolina and Southern North Carolina during the overnight hours.

Further South, the cold front will reach the remainder of Florida later this evening and overnight and bring the risk of severe thunderstorms and a few tornadoes.

Any and all preparations for this event should be concluded by early this afternoon.   This will be a very dangerous situation for many people.   Please be prepared and ready at a moments notice.   We here at Firsthand Weather will do our best to be with you every step of the way this afternoon but keep your weather radios handy and pay attention to your local news broadcasts for updates on warnings that occur.    Facebook likes to prevent you from seeing our page if we post a lot of posts, as we likely will this afternoon.   To see what we are writing, you will need to go directly to our facebook pages and website, please do not count on your newsfeed to give you our information.

 

Robert Millette

 

Tornadoes, Some Strong, Looking Likely For Tomorrow

Significant Tornado Parameter - Mid To Late Afternoon

We have a lot to discuss tonight, so I want to keep this article relatively brief and want to get into more specifics on the timeline and exact locations that will likely be impacted tomorrow (Wednesday) and tomorrow night. Last night, I wrote up a very detailed analysis on this severe weather potential that will likely take shape tomorrow, and I encourage you to go back and read that article in case you missed it. Not a lot has changed since that article.

There remains to be a pretty strong model consensus that a potential tornado outbreak could unfold tomorrow across parts of the Mississippi Valley, Tennessee Valley and also including a lot of surrounding regions. I’ll have more on specific locations in just a minute.

A Few Details I Want To Mention:

Before getting into specific locations, a broad mid to upper-level trough is continuing to move eastward as expected, which will set up the proper dynamics for this event to occur. A strong sub-tropical jet stream currently extends from the Pacific into Mexico and is feeding adequate moisture into the southeastern U.S. This moisture plume will continue to expand northward as a frontal boundary continues to push north as a warm front.

As expected, a tongue of drier air should be available at the mid-levels, further destabilizing the environment. Daytime heating tomorrow should adequately destabilize the environment further. A strong low-level jet stream will be present and eventually extend northward. The mid and upper-level winds should increasingly become favorable throughout the day due to the eastward moving trough. Winds will increase and change with height in a clockwise direction (a favorable directional and speed shear environment). Basically, conditions will be very favorable for supercells capable of producing tornadoes. In fact, some of these tornadoes could be strong.

As I’ve mentioned several times already, overnight and early-morning convection could keep the environment more stable than expected, however I wouldn’t count on that occurring. It’s really only going to take a couple hours of sunlight to quickly destabilize the atmosphere, and the model guidance indicates that any leftover convective activity will move out in time.

Locations In The Danger Zone:

Please take special note if you’re in the areas that are listed.

Highest risk for tornadoes tomorrow (some strong): eastern half of Arkansas, northern half of Louisiana, much of Mississippi (higher chance of strong tornadoes), western and central Tennessee (higher chance of strong tornadoes), western and northwest Alabama (higher chance of strong tornadoes in northwest Alabama)

Additional regions that could be at risk for tornadoes: the rest of Alabama, the rest of Louisiana, western half of Kentucky, southeastern Missouri, southern parts of Illinois and Indiana and early on in eastern Texas. The threat could expand eastward into parts of Georgia towards Wednesday evening. I will also be keeping a close eye on the possibility of this threat expanding into eastward parts of Tennessee, western North Carolina, and Upstate South Carolina into the overnight hours, although the greatest tornado risk will occur west of these areas.

Significant Tornado Parameter – Early Afternoon:

Significant Tornado Parameter - Early Afternoon

Significant Tornado Parameter – Mid To Late Afternoon:

Significant Tornado Parameter - Mid To Late Afternoon

Significant Tornado Parameter – Early Evening:

Significant Tornado Parameter - Early Evening

Concluding thoughts:

Again, nothing is ever certain, but this could end up being a high-impact severe weather event. I wouldn’t be surprised if SPC upgrades parts of the enhanced risk to a moderate risk for parts of Mississippi, Alabama, and western Tennessee. If you’ll be traveling during this time, please check the weather frequently and have a plan in place if you live in any of the mentioned locations.

Latest SPC Outlook (will be updated in an hour or two):

SPC Tornado Outlook

Tornadoes, Some Strong, Likely To Impact U.S. Today

SPC tornado forecast

I posted a fairly lengthy discussion on the site the other day on this upcoming severe weather potential. Due to being busy this week, I’m not going to be able to make my own maps like I promised, so the SPC’s convective outlooks are going to have to do. SPC typically does a very good job when predicting these kinds of events!

Anyway, if you want a more detailed discussion, please refer to my older article, which is still fairly up-to-date. The environment is becoming very favorable for the development of discrete supercells later this afternoon, and I expect some of these cells to become tornadic. I won’t get as much into the thermodynamics and kinematics today like I did the other day, but I do want to show you a visible satellite image.

satellite image

As you can see, the cloud-cover is very thick over much of Texas into central Oklahoma due to storminess over the area. That doesn’t mean that tornadic storms won’t develop in that region, but if this cloud-cover can stay thick enough, it will hinder the environment from becoming as unstable. There is a pretty sizable cap over the region, so daytime heating will be needed to erode that cap.

However, the residents in the area farther north and northeast of the region mentioned above need to watch today’s severe weather situation very closely. The hotspot will be from north and northern Oklahoma, southeastern Kansas, across Missouri, and into Illinois, where tornadoes (possibly strong and long-track) could occur. As you see on satellite image, there are breaks in the cloud-cover so the atmosphere is continuing to become very unstable over that region.

Here is SPC’s tornado probability map. Especially if you’re in the black hatched region, you need to be prepared for the potential of tornadoes, some of which could be strong. Always have a plan in place, and have a way to get alerts from your local NWS office.

SPC tornado forecast

Multi-Day Severe Weather/Tornado Threat This Week

SPC's Thursday Outlook:

This upcoming week is likely going to bring one of the biggest severe weather/tornado threats that has been seen in quite a while. Over the past two years, the tornado season has been unusually quiet, and this year hasn’t been any different so far. I mentioned on the site and on social media several weeks ago that I believed that a window would open up later in April going into May that could prove to be active and quite dangerous. We are quickly approaching that window, and this week will be the beginning of a several week period of severe weather across parts of the United States.

Before I get into the details on this week, I want to point out that some of the most memorable tornado seasons are years that were not-so-active. One recent example of that would be the 2013 EF-5 Moore tornado, which occurred during an anonymously quiet season. Regardless of the overall numbers when everything is all said and done, I can assure you that the people who are impacted by a tornado care nothing about averages, because to them, it was a bad season. With that said, the period we’re entering could bring an average to above average number of tornadoes, so I do believe we’re about to come out of this “tornado drought.”

Persistent mid and upper-level ridging over the western U.S. and Alaska (due to warmer waters in the Gulf of Alaska and along the western U.S. coast) has kept the overall pattern unfavorable for severe weather over the last couple of years. However this week, there’s going to be a change in the overall pattern, with troughing developing over the West Coast and broad ridging farther east. In fact, medium and long-range model guidance continues to hint at this being a trend the rest of this season. I believe this will be the case at least through parts of April going into May, and we’ll just have to wait and see what happens beyond that. All of this means that a more active severe weather period is probably on the way.

I want to briefly break down this week’s severe weather/tornado threat. Keep in mind that there could be an outbreak of tornadoes on Wednesday and Thursday. I use the term ‘outbreak’ loosely because different people interpret that differently than others. In this article, I’m going to use SPC’s maps, but I’ll be making my own maps and will try to have them posted by sometime Tuesday.

Tuesday:

The atmosphere is going to be very unstable across the Southern Plains on Tuesday, but it seems that a strong cap is going to be in place. A cap is a warm-layer of air on top of a cooler-layer of air at the surface. It’s almost like putting a lid on the atmosphere, which hinders storms from developing. If those air particles can’t rise, then they can’t cool (adiabatically), condense, and develop into towering clouds and produce precipitation. However, there are times when this cap can be eroded away with a certain mechanism, such as heating the surface, adding moisture to the atmosphere, or a favorable pattern forcing the air upward vertically or moving that above-the-surface warm-layer out of the area.

This is the exact situation that we have on Tuesday. IF the cap can be taken care of, then supercells capable of producing severe weather could occur and maybe even produce a few tornadoes. SPC has only placed a marginal risk for severe weather across parts of the Southern Plains, not because they don’t think these storms will be severe but because it’s uncertain whether or not they’ll actually develop due to the cap. Hopefully that makes sense, and let’s hope that the cap holds strong.

SPC’s Tuesday Outlook:

SPC's Tuesday Outlook

Wednesday and Thursday:

All of the ingredients are going to be in place to support the development of supercells across portions of the Southern Plains on Wednesday, and that threat will shift farther east on Thursday, which will include parts of the Southern Plains and extending northeastward into the central and upper Mississippi Valley and approaching parts of the Great Lakes.

Moisture is going to get pumped northward from the Gulf of Mexico, and the heating of the day will make the environment very unstable. Wind shear (the changing of wind direction and speed with height) is going to be favorable for storms to develop, maintain their strength, and rotate. The mid and upper levels will be supportive enough to lift the air up through the atmosphere, causing air particles to cool, condense, and form towering clouds and precipitation. All modes of severe weather including tornadoes will be possible. The low-level winds will also be supportive (another necessary component) for the development of possible tornadoes.

Even though the main focus seems to be on Thursday, which I agree could be a big day, Wednesday needs to be watched just a closely. Storms that develop on Wednesday could carry over into the next day, and that will need to clear out in order for the environment to be as conducive for discrete supercells. All of the necessary ingredients will be available both days, but it only takes one small hindrance to cause a bust. At this time, I don’t expect this to be a bust for either day, so residents that are in the zone outlined on SPC’s maps below need to adequately prepare for this potential outbreak of severe weather.

Again, I’ll post my own maps on Tuesday and will also try to post another article. If I see that the severe weather threat is going to extend farther east beyond Thursday, I’ll detail that later in the week.

SPC’s Wednesday Outlook:

SPC's Wednesday Outlook:

SPC’s Thursday Outlook:

SPC's Thursday Outlook:

Tornado Outbreak Looking More Likely For Tomorrow

I’m going to keep this update rather brief since it’s getting late, but I wanted to give everyone across the Central Plains a big heads up on the potential severe weather outbreak tomorrow. A shortwave trough is currently located in the western United States and will move over the Central Plains during the day tomorrow. A frontal system is currently located over Kansas, which will lift northward as a warm front throughout the day tomorrow. This warm front will sit along the Kansas/Nebraska border as a surface low quickly strengthens in Colorado and eventually moves eastward along the Kansas/Nebraska border into Missouri and Iowa. Ahead of a cold front that will extend from the surface low pressure system and south and along the warm front is where rapid supercell development will be likely tomorrow.

To break all of this down a little further and make it a little easier to understand, temperatures are going to climb well into the 80s and dew points will be well into the 60s along and south of the warm front. This will allow the environment to become increasingly unstable throughout the day on Tuesday, and the mid to upper level system that will be moving over the region during the day on Tuesday will provide sufficient wind shear, which will allow for rapid supercell development. Many of these storms could become tornadic with a few of these tornadoes likely being strong. Damaging winds and very large hail will also be likely with any supercell that develops. Because of the parameters that will be in place, the environment will be conducive for these air parcels to quickly accelerate upward, condense, and develop into towering supercells.

Storms will begin developing into the afternoon in Kansas and Nebraska and will eventually push eastward into Iowa, Missouri, and Illinois. To get more specific, the initial threat will begin in Kansas and Nebraska particularly along the Kansas/Nebraska border, where the warm front will be located, and northward into central and eastern Nebraska. An area that may be currently being overlooked is in western Kansas, where initially a supercell or two may try to develop and become tornadic, quickly moving northeastward. If earlier convection does not hinder any later development, tornadoes across the regions that I just mentioned will be likely. The threat will then push eastward into northern Missouri, the lower two-thirds of Iowa, and eventually into Illinois into the evening and overnight hours. Later into the evening/overnight hours, these storms may try to cluster up, and while the tornado threat would continue, damaging straight-line winds would also be a big threat.

If you do not like the Firsthand Weather Facebook page, be sure to go like it. I will be putting numerous updates on that page throughout the day tomorrow! Please share this post to get the word out to those that will likely impacted by this potentially significant severe weather event.

SPC's Latest Convective Outlook for Tuesday

SPC’s Latest Convective Outlook for Tuesday

Update at 1:30 pm EDT: I wanted to share my tornado outlook map and the discussion that I shared along with it. The forecast above that I posted last night still looks good given the latest model guidance. Below is what I posted on the Facebook page about an hour ago.

Discrete supercells will likely develop later this afternoon and evening inside and around the outlined region on this map. Given the expected environmental conditions, many of these storms could quickly become tornadic, some of which could be strong. I am still watching the possibility of some lone supercells developing in parts of Kansas, but the main risk will be across Nebraska and will eventually extend into portions of western Iowa and northwestern Missouri. The Nebraska/Kansas border needs to be watched closely also, right along the warm front, and also into southern portions of South Dakota.

Again, supercells capable of producing tornadoes will rapidly develop later this afternoon. Some of these tornadoes will be strong. A damaging wind threat will likely extend eastward into Iowa, northern Missouri and eventually Illinois later tonight. Please refer to my earlier Facebook updates for more details on that.

Tornado Outlook

This is the highest tornado-risk area. Some tornadoes could be strong.