re: February 2019 Cold blast and southern snow discussion thread

06z GFS this morning... still snowing in CenLA & north LA... but now the NOLA northshore getting in on the action

Same problem, the moisture being there when the cold arrives is suspect. You've got a better shot up in central La, but wouldn't expect much.



The gap there between the red and green shows you a dry lower level for central louisiana. PWat is 0.44 in, so not a lot of moisture available and a big pocket to evaporate quickly as it gets close to the ground.

I'm looking down the line for a snow opportunity, as a disturbance keeps showing up in the gulf when there is cold around. The problem with that so far is that it's too far south but the Pacific is presenting a complicated scenario currently that probably isn't getting modeled well. Even so, the overall set up about to show up is allowing too much west to east flow to get any cold shots to stick around. NAO isn't cooperating, Pacific ridge not lined up ideally either.

In short, there's some small potential but requires a whole lot to time out exactly right.

Those look like those systems that start off as rain and changes over to snow.
90% of the time the systems either don't produce the anticipated precipitation, or never change over to snow on the back end

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Some of the projections for next week are insane...projecting into the negative 20s for TEMPS

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This makes me wonder how far off the predictions for our temps may be. Temps being THAT cold usually spill south more so than models often predict.

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This makes me wonder how far off the predictions for our temps may be.

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I suspect they'll end up being pretty close to what's projected, maybe with a little bias to the colder side. I'm of the mind the models are overdoing the actual cold a little bit. Still, exceptional cold.

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Temps being THAT cold usually spill south more so than models often predict.

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Even if they do, which I mean, isn't unreasonable to think they may it won't be able to stick around long. As the lobe of cold dives into the midwest, there's no blocking high out toward Greenland to keep it from progressing east. The EPS has a blocking high actually build in late in the week, just as the west coast riding brakes down.

Nothing to force it south or keep it in place for very long. Thankfully for our Chicagoland posters.

The Euro is also on board, mostly because it's coming in just a little colder. Again, healthy scepticism on the moisture surviving but it's getting hard to ignore the persistent signal from both. Especially up north of 10/12.

LIX is talking about it now too, but not in the office forecast yet.

I'm not expecting much of anything in BR and points south but the odds are trending up at least.

Area Forecast Discussion
National Weather Service New Orleans LA
347 PM CST Fri Jan 25 2019

.DISCUSSION...
High pressure will remain in place through Saturday. Cool
temperatures can be expected on Saturday. Day time highs should
only reach the 50s, and overnight lows will dip into the 30s.
Sunday temperatures moderate some as highs should begin to climb
back into the 60s, and overnight lows should be mostly in the 40s.
The pattern remains fairly benign through Monday. No precipitation
is expected through Monday. The big story going into next week
for the country will be the punch of cold air expected to move
into the eastern United States and the chance of snow across the
Deep South. A front will move through the region on Tuesday.
Guidance suggest that there could be some moisture available as
the front comes through and with cold air rushing in behind it for
a changeover to wintry precipitation as the front exits the area.
I have not included this in the official forecast as the guidance
is hard pressed to suggest wintry precip this far south. The GFS
is warmer than the ECMWF. I have tried to maintain a blend of
guidance. Will have to watch this as more guidance comes in
house, but for right now we are expecting all rain for our
immediate area. If the GFS show a colder signal over the next few
days, my confidence would increase at the possibility of wintry
precip in our area...however...models do sometimes struggle with
cold air progression and depth. Strong cold air advection will
drive temperatures well below freezing across most of the CWA
Tuesday and Wednesday nights. Tuesday night we could be looking at
a hard freeze for areas north of Lake Pontchartrain. Highs on
Wednesday and Thursday will be a good 10 degrees below average in
the lower to middle 50s. By Thursday, a largely zonal flow
pattern is expected to develop in the mid and upper levels.

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Schools were off yesterday and today up this way due to ice. 19 degrees right now.

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They closed in Anchorage because it got too warm...

Roads turned into rinks