Re: *FEBUARY 19th/20th 2012 SNOW THREAT*

by **Stovepipe** 2012-02-20, 3:14 pm

Saw these posted at American:

*FEBUARY 19th/20th 2012 SNOW THREAT* - Page 39 Wsuz5d

*FEBUARY 19th/20th 2012 SNOW THREAT* - Page 39 2mwba6r

by **Stovepipe** 2012-02-20, 3:15 pm

John1122 wrote:I got 4.5 inches of snow, but also a nasty nasty case of food poisoning. I spent 16 hours yesterday (4am-8pm) with the vomitng/dry heaves. It feels like I've been in a car wreck today my abs and ribs are so sore from it.

Damn John, sorry to hear that. You didn't even get to enjoy all that snow. yikes

by **John1122** 2012-02-20, 3:39 pm

Yeah, it pretty much sucked. I got to see it falling out the window is about it.

by **Homemommy** 2012-02-20, 3:58 pm

John1122 wrote:Yeah, it pretty much sucked. I got to see it falling out the window is about it.

Sorry to hear that. Glad you checked in, we was worried about you. Congrats on the snow. You're the winner of the most snow. king

by Vanster67 2012-02-20, 4:47 pm

John1122 wrote:I got 4.5 inches of snow, but also a nasty nasty case of food poisoning. I spent 16 hours yesterday (4am-8pm) with the vomitng/dry heaves. It feels like I've been in a car wreck today my abs and ribs are so sore from it.

Damn glad you are ok. Hate that you got sick. Glad you are feeling better, and at least got to see the snowfall.

by **John1122** 2012-02-20, 6:32 pm

For people who always go on about ground temps, snow started falling with the temp at 37 degrees and the balance accumulated at 34 degrees. It had been in the 50s leading up to it. Heavy snowfall rates will overcome above freezing temps every time.

by **Toot** 2012-02-20, 6:40 pm

John1122 wrote:For people who always go on about ground temps, snow started falling with the temp at 37 degrees and the balance accumulated at 34 degrees. It had been in the 50s leading up to it. Heavy snowfall rates will overcome above freezing temps every time.

Preach on brother...preach on!! Sadly there will still be those that bring up ground temps during a snowstorm. I predict somebody will be screaming something about ground temps this March when a threat appears on models. Those damn ground temps lmao

by **John1122** 2012-02-20, 6:49 pm

When the big sliver dollar sized flakes start rolling down they accumulate. It melts some from below and you get compression but the snow is falling so quickly that it piles up much faster than it can melt.

Now if the temps were a bit colder we'd have gotten much more snow, probably over a foot. But still, it can and does accumulate with temps above freezing and when the ground is warm.

by **John1122** 2012-02-20, 6:53 pm

That said, it put me at 8 inches on the year. It kept me from having my least snowy winter ever and even though it's only about 40% of the normal snowfall here I'm reasonably satisfied with how hard snow has been to come by for everyone this winter.

Hopefully we get at least one more system that gets every one. Honestly I can't imagine it happening again but this year is going amazingly like 1992-1993. That year also featured almost no snow anywhere, then 4 inches around Feb 20th after temps had been near 70 in the week leading up to it.

by **Toot** 2012-02-20, 7:44 pm

John1122 wrote: Honestly I can't imagine it happening again but this year is going amazingly like 1992-1993. That year also featured almost no snow anywhere, then 4 inches around Feb 20th after temps had been near 70 in the week leading up to it.

by **Stovepipe** 2012-02-22, 9:03 am

After thoughts from Chattanooga met nrgjeff at American:

I under-estimated the back piece of upper-level energy for North Carolina east of the Apps. My last forecast post was back on Friday before going to ski. It was mountain-focused, fading the Piedmont. Left the door open, but with lots of doubt. Very happy it worked out for y'all receiving snow. Tennessee went as I figured: no snow in the valley of death; accumulation Plateau, Smokies and extreme northeast Tenn.

The system was tilted from the surface low at the coast, to the mid-level low over NC, back to the 500mb wave and cyclonic jet streak back over the Tennessee Valley. I'm not talking positive/negative tilt, but vertical tilt. The "Saturday" night rain-maker lead short-wave (s/w) had pushed offshore by Sunday morning while the back s/w was just coming across Tenn. Many times we see that second s/w fizzle as it approaches the "main" system. This time it would appear that the "main" upper-level system was the back one, even as the surface low moved along. When rain changed to snow in the Piedmont that precip was driven by PVA from the back s/w; lead s/w was about off-shore. Meanwhile the 700 and 850 lows tracked out of GA/SC into southern NC, promoting the snow in northern NC. North winds sfc to 700 cooled the column as the lift/PVA came in from Tenn. The system was vertically tilted, helping precipitation hang back long enough for lower levels cool off and change it to snow. Normally I'd still forecast the second s/w to weaken; and, lead s/w rain to end before the cold air arrives. However, this case was different because of how the system lined up well vertically.

Perhaps the copious amount of moisture available, with the tropical tap, also promoted the efficiency of the back s/w. The models honed in on the vertically tilted structure and healthy QPF with the second/back wave by 24-36 hours out. While model performance could have been better, operational forecasters can learn from this system. Though no two are alike, this one is yet another addition to the pattern recognition tool belt. Enjoy!