Jump to content
  • Forum Image

Recommended Posts

Good morning! 
A really great day is on tap for today! How about those winds yesterday, it sounded like the roof was going to come off the house! ūüôā¬†

Most of the country is starting off a little below normal this morning and the same goes for our area. You can see three areas on the map that aren't below normal, the desert southwest, and the tips of TX and FL. Snap346065020.thumb.png.5761c8c16882ee8ea041085fde486968.png

 

8 AM temperature anomaliesecmwf-deterministic-atlanta-t2m_f_anom-7988800.thumb.png.c46a00827b01c4013c64854278187a27.png

 

Temperatures will rebound nicely today and almost everyone should see highs near 70.
ndfd-conus-atlanta-t2m_f_max_last24-7945600.thumb.png.a4d24eee78667e6a67333c6e49369050.png


If you like today, you're really going to like Tuesday.
ndfd-conus-atlanta-t2m_f_max_last24-8032000.thumb.png.7b0219864a885499fca6752a3ebb2cc5.png


There is a Marginal Risk for severe weather on Wednesday with some thunderstorms across north Georgia, but these shouldn't be a very big deal. 

Quote

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0230 AM CDT Mon Apr 27 2020

   Valid 291200Z - 301200Z

  • ¬† ¬†THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS¬†OF COASTAL TX INTO THE SOUTHEAST...

   ...SUMMARY...
   Isolated strong to severe thunderstorms may occur Wednesday across portions of coastal Texas into the Southeast.

   ...Coastal Texas into the Southeast...
   A line of storms will probably be ongoing Wednesday morning across parts of coastal TX into southern LA ahead of a surface cold front. A lingering strong/gusty wind threat may continue with this convection before it moves offshore. Farther north, an upper low is forecast to move from the MS Valley eastward while amplifying through the period. A mid-level jet should gradually overspread parts of the lower MS Valley and Southeast through the day. At the surface, a low should develop slowly eastward over the Great Lakes region while gradually occluding. A cold front attendant to this low is forecast to sweep eastward across the OH/TN Valleys and Southeast on Wednesday, eventually reaching the vicinity of the East Coast by the end of the period.

   Depending on the location and intensity of the morning convection across the lower MS Valley, there appears to be a window for at least weak destabilization across parts of the Southeast ahead of the cold front Wednesday afternoon. This potential appears relatively greater across southern MS into southern/central AL, the FL Panhandle, and parts of GA. Strengthening shear through the day with the mid-level jet overspreading this region would support organized storms. The main uncertainty precluding higher severe probabilities for now is the amount of destabilization that may occur. Regardless, at least an isolated severe risk for mainly large hail and strong to locally damaging winds appears plausible. This threat may continue eastward Wednesday evening and overnight along/ahead of the cold front across parts of northern/central FL, GA, and SC.
http://www.daculaweather.com/4_spc_day3_outlook.php

204055282_SPC_CO_Day3State(3).thumb.png.339c0aa03952a0f49b2af3f0022fa545.png

 

Let's take just a moment to remember the 316 people that perished on this date in 2011 during the April 27-28 Super Outbreak.

Snap346065027.png.546a8b73b185a41dc9a29d6764ea2a25.png
Snap346065028.png.674ba0e16b5a1dfa523129728164f7e1.png

 

Fortunately, so severe weather for us today, so I hope you can get outside and enjoy a nice spring day.
Have a great Monday!

ffc-27.png.86f229c6f4ed4efac7f3dbc9b530b319.png

mrx-27.thumb.png.e69aea049bf511c43aca0c61cc478fdb.png

bmx-27.thumb.png.8e6f691602779c08131e658845b8ae6c.png

  • Like 1

Share this post


Link to post
Share on other sites
Quote

April 27

The outbreak was caused by a vigorous upper-level trough that moved into the Southern Plains states on April 25. An extratropical cyclone developed ahead of this upper-level trough between northeastern Oklahoma and western Missouri, and moved northeastward.¬†Conditions were similar on April 26, with a predicted likelihood of severe thunderstorms, including an extended threat of strong to violent long-track tornadoes throughout the afternoon and evening hours; mixed-layer CAPE values were forecast to be around 3000‚Äď4000 J/kg, around east Texas, Louisiana, and Arkansas. The storm mode on April 26 was predicted to include mostly discrete tornadic supercells during both the afternoon and the early evening, shifting over to a mesoscale convective complex, with more of a threat of damaging winds and hail during the nighttime hours.

As the storm system moved eastward toward the Ohio, Mississippi, and Tennessee Valleys on April 27, a very powerful 80‚Äď100 knot mid-level jet stream moved into the Ohio and Tennessee Valleys behind the trough and created strong wind shear, along with a low pressure center moving quickly northeastward across those areas on April 27. During the afternoon of April 27, CAPE values were estimated to be in the range of 2000‚Äď3000 J/kg across Louisiana and southern Mississippi, with the moderate instability moving northeastward across the southern Tennessee Valley; additionally, temperatures across the southeastern United States ranged from the 70s¬įF (mid-20s¬įC) to the lower 90s¬įF (near 35 ¬įC). Helicity levels ranged from 450‚Äď600 m2/s2, which supported some significant tornadic activity and strong to violent long-track tornadoes.

A total of 56 severe weather watches were issued by the Storm Prediction Center (SPC) over those four days in the outbreak area. This included 41 tornado watches‚ÄĒ10 of which were Particularly Dangerous Situation (PDS) watches‚ÄĒand 15 severe thunderstorm watches.¬†The SPC assigns numbers to each severe weather watch issued starting at the beginning of each year; the organization unsuccessfully used two of their allocated watch numbers during this outbreak (numbers 208 and 209).


Significant severe weather was ongoing early on April 27 (in the overnight hours) and continued for the entire calendar day virtually unbroken. For the second day in a row, the SPC issued a high risk of severe weather for the Southern United States. Later that morning, the SPC even increased the probability for tornadoes to 45 percent along a corridor from Meridian, Mississippi, to Huntsville, Alabama, an extremely rare issuance exceeding the high risk standards. Conditions became increasingly favorable for tornadoes during such an extreme tornado outbreak.

Morning squall lines
During the early morning hours, a cold front with several embedded low pressure areas extended from east Texas northeastward into the Ohio River Valley. An upper-level disturbance that had moved across the frontal boundary the previous evening sparked an area of thunderstorms that morphed into a squall line. This line of severe thunderstorms would produce tornadic activity from the evening on April 26 into the late morning of April 27. Early in the morning the squall line, packing straight-line winds and numerous embedded tornadoes, moved through Louisiana and Mississippi before proceeding to affect North and Central Alabama and parts of Middle and East Tennessee. The line strengthened as it moved through Alabama, partially due to a high amount of low-level moisture from the Gulf of Mexico and increasing wind shear.

A majority of the tornadoes embedded in this initial squall line were weak, though several were strong and as such caused significant damage.

An EF3 tornado caused major damage to homes in Coaling, Alabama, an EF2 and an EF3 tornado produced severe damage and a fatality near Eupora, Mississippi.

Another EF3 tornado resulted in heavy damage in downtown Cordova, Alabama, which was struck by a violent EF4 tornado later that afternoon.

One embedded cell that began in Cullman County, Alabama produced a long-tracked EF2 tornado that struck the town of Hanceville, killing one person. That cell would then produce over ten tornadoes (most rated EF1) to the northeast in Marshall County and another EF1 tornado in Dade County, Georgia. The initial storms caused widespread power and telephone line outages across Alabama and Tennessee. This line of storms also caused some NOAA weather radio transmitter sites to stop functioning for the remainder of the outbreak. Because of this, more than one million customers were without power and had no warning of any approaching tornadoes later that day.[38]

From the late morning to the early afternoon, another squall line moved through northern parts of Mississippi and Alabama as high wind shear and low-level moisture persisted. However, this time several discrete supercells developed along and in front of the line, spawning seven weak tornadoes across Morgan, Limestone, and Madison Counties in northern Alabama around noon that day.[38]

Quote

Afternoon supercells

Extremely deep ground scouring near Philadelphia, Mississippi caused by a fast-moving EF5 tornado that killed three people.
The most intense supercells of the outbreak developed around midday in central Mississippi and began tracking eastward. During the early afternoon, as wind shear and low-level moisture continued to dramatically increase, a tornado emergency was declared for Neshoba County, Mississippi, as a large tornado was reported on the ground by both storm spotters and a camera atop a television tower from ABC affiliate WTOK-TV (channel 11) in Meridian, Mississippi. This powerful EF5 tornado caused incredible damage northeast of Philadelphia, Mississippi, where pavement was torn off from roads, vehicles were thrown, and the ground was scoured out to a depth of 2 feet (0.61 m) by the tornado. Three people died when a mobile home was thrown 300 yards (270 m) into a wooded area, obliterating it in the process.[39] Another very long-tracked EF4 tornado passed near the town of Enterprise, Mississippi, killing seven people before crossing into Alabama and eventually dissipating.

Responding to the high risk issued by the SPC and the already unstable atmosphere expected to become even more unstable throughout the afternoon hours, a PDS tornado watch was issued at 1:45 p.m. CDT (1845 UTC) for much of Alabama and portions of Mississippi, Tennessee, and Georgia. A widespread complex of supercell storms overspread the states of Mississippi and Alabama and violent tornadoes began rapidly touching down as the evening progressed.[38] Four tornadoes were officially rated EF5 on the Enhanced Fujita scale that day.

One of those EF5 tornadoes struck the town of Smithville, Mississippi, where many well-built brick homes were reduced to bare slabs, numerous hardwood trees were completely debarked, and an SUV was hurled half a mile into the top of the town's water tower, subsequently leaving behind a visible dent. Another long-tracked EF5 wedge tornado passed through rural portions of Alabama and Tennessee, becoming the deadliest tornado of the outbreak as it completely devastated the towns of Hackleburg, Phil Campbell, Mount Hope, Tanner, and Harvest, killing 72 people. This marks only the second day in history (after April 3, 1974) that there were more than two F5/EF5 tornadoes reported.[40]

The tornadoes continued tracking through central Alabama that afternoon and into the early evening hours. A dangerous and destructive tornado struck the city of Cullman, Alabama at around 3:00 p.m. CDT (2000 UTC). This large, multiple-vortex tornado was captured on several tower cameras from television stations, such as Fox affiliate WBRC (channel 6) and ABC affiliate WBMA-LD/WCFT-TV/WJSU-TV (channels 58, 33, and 40) both out of Birmingham. The tornado caused extensive destruction in the city's downtown area; it was ultimately rated EF4. The final damage count was 867 residences and 94 businesses in Cullman, and six people died.[41]

The town of Cordova, Alabama, which had already been damaged by an EF3 tornado from the initial round of storms, was struck by an EF4 tornado that killed 13 people.

Two violent EF4 tornadoes also ripped through Jackson County, Alabama, one of which caused a fatality near Bridgeport while the other passed near Pisgah and into Georgia where it caused major damage in Trenton and killed 14 people.

At around 5:10 p.m. CDT (2210 UTC), a very large and exceptionally destructive tornado struck Tuscaloosa, Alabama and about 40 minutes later, that same tornado struck the northern suburbs of nearby Birmingham.[42] A tornado emergency was issued for both cities, along with many other cities that day. Many local television stations, including WBRC and WBMA-LD/WCFT/WJSU, as well as CBS affiliate WIAT (channel 42), broadcast live footage of this long-tracked tornado in both Tuscaloosa and Birmingham. A debris ball was observed by the Birmingham NEXRAD, indicating that the tornado was causing extreme damage.[43] This tornado killed 64 people and caused extensive devastation in densely populated areas, and the tornado struck several of the same small communities as the April 1956 F4, the April 1977 F5 and the April 1998 F5 tornadoes that hit portions of the Birmingham area. The supercell that produced the Tuscaloosa/Birmingham EF4 tornado originated in Newton County, Mississippi.

The supercell also produced an EF4 tornado later that evening that killed 22 people and struck the Ohatchee, Alabama area and eventually crossed into Georgia, causing additional damage near Cave Spring before dissipating.

Further to the south, a mile-wide EF3 tornado killed 7 people in mostly rural areas and caused major damage in the small town of Eoline.

The final EF5 tornado of the day caused remarkable damage in and around the town of Rainsville, Alabama, killing 25 people before crossing into Georgia and dissipating. Tornadoes continued touching down further to the northeast as the sun set, particularly in Georgia. This included a long-tracked EF4 tornado that caused major damage in Ringgold, Georgia, Apison, Tennessee, and Cleveland, Tennessee, killing 20 people along the path.

After dark, violent tornadoes continued to touch down, and a nighttime EF4 tornado destroyed many lakeside homes at Lake Martin in eastern Alabama, killing seven people.

Additional strong nighttime tornadoes occurred in Georgia, including an EF3 that killed two people in Barnesville, and another EF3 that destroyed homes and killed one person at Lake Burton.[44][45]

 

Share this post


Link to post
Share on other sites

There is a video where all the storms across AL, Ms and Ga are chronicled that day and shown by radar.  The morning storms are more linear and surrounded by rain and typical of our area. ,  But that afternoon as the system moves along clearing occurs and then the super cells appear, and almost every one have the perfect hook, and many the debris balls of powerful twisters.  Unlike normal situations these were not rain wrapped and the Cullman Tornado was a monster, a beauty of incredible multi vortexes.  The 4ef5's in one day was unheard of...   No wonder it is called a 100 year event.  It was like we got a taste of Tornado Alley and Dixie Alley mixed together and served up in one storm-- in one area....

  • Like 1

Share this post


Link to post
Share on other sites
2 hours ago, NorthGeorgiaWX said:

Day 7 may bring some record highs to the southeast 

ndfd_record_high_se_7.thumb.png.0859cbe6f063b032ab3598c7b2670371.png

Guess we can't complain to much! It has been rather nice the last few weeks and actually Spring like.

  • Like 2

Share this post


Link to post
Share on other sites
54 minutes ago, RickyD said:

There is a video where all the storms across AL, Ms and Ga are chronicled that day and shown by radar.  The morning storms are more linear and surrounded by rain and typical of our area. ,  But that afternoon as the system moves along clearing occurs and then the super cells appear, and almost every one have the perfect hook, and many the debris balls of powerful twisters.  Unlike normal situations these were not rain wrapped and the Cullman Tornado was a monster, a beauty of incredible multi vortexes.  The 4ef5's in one day was unheard of...   No wonder it is called a 100 year event.  It was like we got a taste of Tornado Alley and Dixie Alley mixed together and served up in one storm-- in one area....

Think of that event as a spring time Storm of The Century. 

Share this post


Link to post
Share on other sites

tclbhm_supercell.thumb.png.34935ae191f87e13f3a8d27e654d9ba8.png

That same supercell that produced the Tuscaloosa tornado is the same one that produced a high end ef-3 here in Rabun later that night. Luckily it only killed 1, but if it had been just a month later it would have been a disaster. The area of the worst damage was mostly summer/vacation homes, so at the time they were vacant. It was the first debris ball ever recorded on the GSP radar. GSP has a great study on that tornado as well as the whole event here: https://www.weather.gov/gsp/EpicOutbreak

Share this post


Link to post
Share on other sites

That was a wicked day. I HATE seeing individual cells like those, you know each one is going to have a tornado.

 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Who's Online   0 Members, 0 Anonymous, 9 Guests (See full list)

    There are no registered users currently online



√ó
√ó
  • Create New...