Feb 13-14 - valentines southern slider

[jmundie]

Boo ya.

Lets hope this doesn't jinx it.

[aubieman]

Let the record show that over a week ago I predicted a Valentine's Day snowstorm.  I did it in jest, but I still posted it somewhere.

[ams30721us]

12z Euro:

[jmundie]

Nashville wetbulbs to below freezing at the surface per the euro. First time I've seen that for this threat.

Looks like some rain/freezing rain may mix early am. Temps look to stay in the mid 30s to 40 on valentines day, and a mini shot of cold air comes in as the system passes by (850s down to -4 to -8)

[Kevin]

People using the Wunderground maps need to take extreme caution...its WAY overdoing amounts...actual data for instance would show little if any snow in Memphis despite the maps showing 'several' inches.

[Woodvegas]

12Z ECMWF MOS QPF for BNA is 0.55 inches.

[Eric]

People using the Wunderground maps need to take extreme caution...its WAY overdoing amounts...actual data for instance would show little if any snow in Memphis despite the maps showing 'several' inches.

Buzz.  Kill.   

[Kevin]

Buzz.  Kill.   

LOL. Actual sounding-type data just simply doesn't match with those snow output maps. To be sure...Nashville in a better position than most...but Memphis at least is pretty much all rain...though maybe a mix to start.

[jmundie]

People using the Wunderground maps need to take extreme caution...its WAY overdoing amounts...actual data for instance would show little if any snow in Memphis despite the maps showing 'several' inches.

What's wrong with them Kevin? Are you saying the text data doesn't support it?

As far as I can tell - 850s are plenty cold, the surface is wetbulbing to freezing for those north of I40. BL issues? Ratio problems?

[Kevin]

What's wrong with them Kevin? Are you saying the text data doesn't support it?

As far as I can tell - 850s are plenty cold, the surface is wetbulbing to freezing for those north of I40. BL issues? Ratio problems?

I'm looking at some text data (which I can't post here)...and its not as good as the snow output maps. Wunderground is doing something weird much like the Twisterdata maps for NAM/GFS that's way overdoing it. Nashville is still getting some snow...but its mostly Northwest and North Middle sections...and would probably see a late changeover...the stuff on the southern end would be pretty much all rain all together...

[Thundersnow]

Liking this...







...although, I find it interesting that when the model doesn't have us in the bullseye, we say, "Well, I wouldn't want to be in the bullseye at this range anyway."

But, when the model does show us in the bullseye, it's "Awesome!  We're in the bullseye!" 

[ams30721us]

I'm looking at some text data (which I can't post here)...and its not as good as the snow output maps. Wunderground is doing something weird much like the Twisterdata maps for NAM/GFS that's way overdoing it. Nashville is still getting some snow...but its mostly Northwest and North Middle sections...and would probably see a late changeover...the stuff on the southern end would be pretty much all rain all together...

Are you counting in the Evap. Cooling etc.? I have the text data too and while it is borderline its not that bad when considering the other parameters. Not to mention GFS trended toward it which makes me feel a lot better. Now showing NW GA even below freezing at the surface monday night into Tuesday.

[Kevin]

Don't get me wrong...If I were in Nashville...I'd be at least somewhat optimistic...but I'm not looking forward to much of anything back this way yet.

[jmundie]

Liking this...







...although, I find it interesting that when the model doesn't have us in the bullseye, we say, "Well, I wouldn't want to be in the bullseye at this range anyway."

But, when the model does show us in the bullseye, it's "Awesome!  We're in the bullseye!" 

I'm more worried about mixing... but the maps I'm seeing have us at 40% humidity and low to mid 30s before the onset of precip. Evap cooling, I'd imagine takes us down a couple degrees.

What's really weird to me is that precip on Friday night looks like it should be showing accums, but euro wunderground maps aren't. But for this event, which is apparently marginal, it is.

[Kevin]

Are you counting in the Evap. Cooling etc.? I have the text data too and while it is borderline its not that bad when considering the other parameters. Not to mention GFS trended toward it which makes me feel a lot better. Now showing NW GA even below freezing at the surface monday night into Tuesday.

Perhaps something there...but still you also have to remember the arctic airmass is retreating so that doesn't play as much as a role. The big question then is how fast the airmass retreats and whether that allows other ptypes to get involved instead of just pure snow...whether that's rain or even freezing rain/sleet...and I DON'T trust the Euro (or the GFS) to handle that properly.

I would normally be more aggressive about the airmass situation given how slowly arctic air usually is...but with such little snowpack upstream...it's not going to be the usual big positive that it otherwise would be. Could play a role still...and the airmass is looking colder and colder as we get closer.

Like said...If I'm in Nashville or a similar latitude...I'm getting a little hopeful...everybody else - very skeptical for right now.