Powerball

Now it's producing golf ball sized hail.

It looks like a tornado and ping ping size hail has been reported with the cell near Opelika, headed towards Phenix City and Columbus

Atmosphere has recovered nicely. Managed a late day high of 89*F after several hours of clear skies, with dewpoints having pooled back into the mid 70s. The anvils from the storms developing to the west are blowing in now.

Mesoscale Discussion 1122 NWS Storm Prediction Center Norman OK 0237 PM CDT Sat Jul 21 2018 Areas affected...northeast Alabama...east Tennessee...northern Georgia...western North Carolina and western South Carolina Concerning...Severe potential...Watch possible Valid 211937Z - 212200Z Probability of Watch Issuance...40 percent SUMMARY...Isolated to widely scattered storms are expected to develop this afternoon over a portion of the southern Appalachian region. Some of the storms will become capable of producing downbursts winds and possibly some hail. Though a severe thunderstorm watch issuance is possible, it remains uncertain whether storm coverage will become sufficient. DISCUSSION...This afternoon isolated storms are in the process of developing along an old modifying outflow boundary from northeast AL into middle and east TN. Other storms are expected to initiate over the higher terrain of east TN and the western Carolinas. The surface layer in vicinity of the outflow boundary continues to destabilize with diabatic warming boosting MLCAPE to 1500-2000 J/kg based on latest objective analysis. WV imagery shows a band of deeper ascent accompanying a vorticity maximum spreading southeast through east TN, along with a mid-level jet that is contributing to 35-45 kt effective bulk shear. The greater storm coverage will likely remain confined to eastern KY into northeast TN where vertical wind shear and instability are weaker. Storms developing farther south across much of the mesoscale discussion area will probably remain more isolated to widely scattered, but some of the storms could acquire mid-level updraft rotation, and a few instances of downburst wind and hail will be possible. In addition to expected isolated storm coverage, another potential limiting factor for a more robust severe threat is weak mid-level lapse rates. Nevertheless, convective trends will continue to be monitored next couple hours for a possible WW issuance over a portion of this region. ..Dial/Hart.. 07/21/2018 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GSP...MRX...FFC...OHX...BMX...HUN... LAT...LON 35858216 35178190 34648253 33768365 32598476 33088552 34508591 35798518 36248346 35858216

12z NAM still shows an impressive 4000+ J/KG of CAPE later today and LIs of -11 to -12. It also develops a 2nd squall line this afternoon that will dive SE over many of the same areas.

Looks like we've been stealing you guys' severe weather / ring of fire storms. We've had more storm reports in GA than even OK this year, and we're pretty much neck & neck with NE / MO.

Well last night's storms have held their strength and are coming through now. A ton of lightning and a pretty awesome shelf cloud with them. They were sub-severe though by the time they reached here (only winds of 30-40 MPH). That said, I'm surprised there's some decent clearing behind them. That may bold well for a 2nd or 3rd round later today...

Well damn! The latest NAM is showing some stupid crazy instability tomorrow afternoon.

What's crazy is that happened *WITH* a patch of opaque Cirrus over the city for much of the today.

A brief cell did pulse up over Nashville, but it has since fizzled back out. Cap is still holding firm and the CU field is still looking pretty unimpressive right now. We'll see if that changes...

In all fairness, it was a marginal setup that could have easily gone the other way. It was all dependent on mesoscale waves (which models always struggle to handle) that happened to overachieve.

In fact, with storm reports from this stretching from Chattanooga to Mobile (and all places in between), this qualifies as a Derecho. At this latitude, I imagine to have an organized QLCS propagate such a distance from NE to SW in late June is pretty anomalous. Sadly, one person was killed while several people were injured. https://www.al.com/expo/news/erry-2018/06/0d2d6a3a666396/storms_down_trees_power_lines.html

No relief at any point for most of us any time soon if the GFS is correct. Can thank the SW Drought for that.

If you buy the GFS, it gets much worse from here on out once Alberto's out of the way. (granted, you guys in NC may get a more extended reprieve next weekend before the furnace really kicks in).

You may like it now, but I'm thinking just wait until all of that starts evaporating under the June sun angle.

Averages. Atlanta's average high this time of year is in the mid 70s. But between the persistent eastern troughing up until now (thus relentess NW or SE flow) and then what looks to be a split flow type of pattern setting up next week (thus dealing with clouds / rain from cut off lows), we'll do good to get out of the 60s from here on out, which is a fair bit below average.

Please, make it stop...

-6*F 850mb temps and stratocumulus as far south as here in May?

This needs to stop yesterday. If I wanted to use space heaters in April, I would move back to Michigan.

Just awful... We're practically into April, not mid-January!

Well damn!!! 000 FXUS62 KFFC 180835 AFDFFC Area Forecast Discussion National Weather Service Peachtree City GA 435 AM EDT Sun Mar 18 2018 As vigorous shortwave moves east over TN valley, broad and unusually strong westerly flow to the south remains in place. In my experience with severe weather forecasts both here and in the southern plains, this pattern has a great deal of potential to produce atypically high instability and very strong deep vertical wind shear with supercells the dominant mode. It has been over a year since this area has seen supercell storms of this magnitude (Jan 22 2017). Large hail and a few tornadoes will be likely. Given MLCAPE values 2000-2500 J/kg and 0-6km bulk shear of 60-70kts, hail will likely be much larger than the Jan 2017 event with sizes of 2 to 3 inches likely. If there is a bright side to this story, it could be the low level shear, 0-1km bulk shear is only progged of 30-35kts. This is still quite strong and should be sufficient for a few tornadoes, but unlikely to see the larger /long-tracked tornadoes that we saw with the Jan 2017 event or other notable supercell-based tornado events and outbreaks. Interestingly, CIPS top 15 analogs based on 00Z NAM valid 00Z Tue do not contain any events in the last 10 years, so could be some analogs with lower storm report density and thus lower analog probabilities. Top analogs is Apr 3 1998 which produced widespread hail over north GA but other dates have hit or miss coverage of reports and not too many tornado events though there area some. Other bright side of supercell events is that coverage/probability of any point seeing severe storms will be lower than with linear events. Not something you want to take a chance on however, plan accordingly. Have kept PoPs closer to guidance and perhaps lower with mainly 40-60pct Monday afternoon and evening. Will certainly keep a close watch on this and will continue with steady pace of impact briefings.

The latest GFS brings the heat back by mid-month (after a brief "cool down").

Wow! As of today, few trees are already blooming. Crazy!