GaWx

This was a very enjoyable and interesting winter storm of rare proportions here! I measured ~2.9” (mainly sleet…see image below) from a 12 hour long combo starting as sleet for couple of hours, ZR adding to base for a couple more hours, back to sleet (much more that lasted several hours), and then some snow during last few hours often mixed with sleet. And it is a very solid 2.9”! Temperatures during the bulk of it were in the upper 20s. That’s the most accumulation in this area since 12/1989. 1/2018 was ~2” of a combo. I estimate the sleet portion of the 2.9” was 2”, which would almost have to be the most sleet in the city from any storm in modern records (back to mid 1870s). 1/2018 had a good bit of sleet that lasted ~2 hours (including when mixed with snow), but it didn’t get over 0.5”. This was the 3rd most sleet I’ve ever seen behind only two ATL sleetstorms (2/1979, 1/1988). The ZR portion fortunately was much lower here than the ~0.45” in 1/2018. I’m guessing it was ~0.1” with no more than 0.05” of accretion. Thus, there were very few outages in SAV (only ~200). However, Glynn county (Brunswick) has a whopping ~28K outages, which is ~55%! Nearby Charlton county had a similar % out while Camden (~1/3) and McIntosh (~1/4) had fewer but still many out. So, extreme SE GA had by far the most ZR in the state, which was modeled well. I haven’t seen amounts yet. Total liquid equivalent precip was 0.71” at more inland SAV. Based on models calling for an avg of ~0.10” more in my area, I’m guessing ~0.80” for my place, which would be near the similarly impressive ~0.75” I got in 1/2018 (that one lasted ~7 hours). Had all of the precip been snow (which was not forecasted), perhaps I could have had up to 5” based on rough Kuchera type of considerations (nowhere near 10:1 with 850s borderline). Regardless, this 2.9” of a solid layer, if anything, will very likely melt more slowly than 5” of pure snow. After a low near 27, current temp has struggled to only 33. Thus melting of this rock solid accumulation has been very slow. Edit: For me this was not only the Brick storm (thanks @Brick Tamland) but also the Tony @dsaurstorm due to sleet dominating! He would have loved it! Edit #2: I brought inside 2 samples of the frozen precip that I had collected in 2 cylindrical cups to melt it and allow for an estimate of liquid equivalent. I did something similar in Jan of 2018 to estimate it for that winter storm. I plan to post about the results after this is completed. I’m roughly estimating 0.80” based on adding ~0.10” to KSAV’s 0.71”. @Awesomesauce81 @gtg947h @metallica470

I just measured ~1.5-1.75” of mainly sleet mixed in with the ZR of earlier. Totally sleeted in! Everything bright white. It’s amazing how light it looks more like dusk than the middle of the night! And now after an hour of a little snow mixing in with the sleet, the snow, which includes some big beautiful flakes, is increasing at 2:15! On another check at 2:20AM, it’s still majority pouring sleet!

Finally at 12:50AM, I’m after all of these hours seeing some snow mixung in with the still predominant sleet! It’s 28.6F. I have ~1.25” of sleet on the ground! @dsaur would love it! @metalicwx367

ZR changed back to moderate sleet within the last ~45 minutes and with the colder temp (29.0F), it is accumulating nicely on the ground now with ~0.5” measured! Even my asphalt street is starting to turn white. Roads are very slick with some bridges closed. As Don said, it switched to snow at the more inland airport at 10PM but went back to a mix at 11PM. Even Ft Pulaski is at 29F thanks to N winds off the cold land. Sapelo Island and St. Simons are at 32.

1. It’s been mainly ZR for the last hour here after mainly sleet for a couple of hours. That tells me 850s are probably at least ~+3C due to a stubborn warmer area that some models had. 2. 1.1” officially at KATL (overperformed).

It has turned from sleet to a mix of sleet and ZR with 30.4F. Tiny icicles on some leaves. I expect it to turn to snow soon (within a couple of hours at the very most) as the heavier stuff comes in. We’ll see. Sleet getting heavier again.

Down to 31.0F with sleet continuing. Accumulating easily on elevated surfaces.

Also, it doesn’t seem like a big ZR setup in our area with no wedge. That along with your and other reports is very encouraging. The wind is blowing the sleet up against the window. It is accumulating on the leaves of a bush I just looked at. Down to 32.5.

Sleet has just gotten much heavier and it is loud! Temp dropped to 33.4F!

Southside

Sleet started here in Savannah about 5:50PM with 35.4F. Wind blowing hard!

Unofficial FL record is 5”. That is from Jan of 1800 on border with SE GA near St. Mary’s. @donsutherland1knows about that storm. That record being clobbered!

My sis in Emory area FaceTimed me and it is coming down heaviest yet with a nice dusting!

VERY light rain here in SAV just started at 3:30PM with 37.4F.

Do you agree @purduewx80and @SnowGoose69and @CheeznadoATL may be about to get snow? Not only the radar, but Columbus and especially Auburn have been getting snow recently. Also, doesn’t the 1000 ft elevation help ATL? And @dsaur ~30-40 miles south just started getting snow!

Agreed on the temps. -My highest has been ~39 vs 41 forecast. Wetbulb ~31. -Jacksonville’s forecasted high of low 50s won’t be close as high so far only 44 -Brunswick/St. Simons only 42-3 so far. Forecast was 45-47. -Waycross only 44 vs ~46 forecast

Thanks for your insight! Based on the 12Z models, I agree 100%. And regardless, all of the models have increased qpf substantially! For our corridor, Euro is on the low side with 0.65-0.8”. 17Z HRRR is 0.85-1”. ICON and CMC are 0.9-1”. The others are 1-1.25”! The variance in 850s from model to model strongly is affecting predominant precip types (Kuchera snow except Icon): -The ICON and NAM, which have <0.7” of SN, have 850s mainly +1 to +2C favoring IP/ZR. NAM has 1-2” of IP and 0.55-0.80” of ZR as it has ~1.1-1.2” total qpf. ICON doesn’t show IP or ZR, but it would have to be quite high considering the 0.9-1” qpf! -CMC is in between with 0 to +1C 850s till going <0C late. It has ~3.5-4” of SN/IP with ~1.5-2” of IP. It has only ~0.05” of ZR. -Euro: ~+1C 850z til late when it goes <0C. But it somehow still gives 2.5-4” of snow and 3-5” of SN/IP, combined. ZR light (<0.1”). -GFS is significantly colder with 850s starting ~0C and later falling from there. With qpf up to 1-1.25”, it gives 4-6.5” snow/IP (mainly SN)! ZR is surprisingly high considering the 850s with 0.3-0.4”! That looks highly suspect. -17Z HRRR is on the high end of snow/IP (almost all snow) with 7.5-8.5”!! ZR is minimal. Qpf is high at 1.05-1.35”. 850s: start +1 to 0C but fall pretty quickly. So, lots of variance on wintry precip forms for our corridor depending on 850s with this likely historic storm! @Awesomesauce81 @gtg947h

Montgomery, AL, had light snow just start. It is increasing in Hattiesburg, MS, and continues heavy in McComb and N.O. At Mobile it started 3 hours ago. Pensacola NAS just stated getting flurries at 11AM EST with 28 and DP of 20. An hour earlier it was 32/8.

McComb, MS, in far S MS just N of LA border 100 miles NNW of N.O. started snowing at 9AM EST and went to heavy snow (1/4 mile vis) at 11AM! Comparing that to latest models: HRRR, Euro, NAM 3km, and Icon significantly too light while CMC and GFS closer to reality.

Thanks. Fwiw, Greenville, AL, which is S of Montgomery, has snow that started a little while ago. Only official station N of Mobile area with snow. But that’s still pretty far south.

Do you have a good feel for about when S of I-20 would likely get their up to 1/2”?

1.5 hours ago it was looking like ATL could have snow before noon. And now you two both think it probably won’t snow at all?

But we were just talking about the possibility of snow starting in ATL area by late morning.

Even near the airport? What’s changed?

14Z HRRR has spot on dewpoints in ATL and GA in general as of 10AM fwiw. But 12Z NAM 10AM dewpoints too high as KATL at 17F vs reality of 8F. It has dewpoints in other parts of GA also too high. Something to keep in mind when considering qpf differences between the two models at least in GA. HRRR may be more realistic.