purduewx80

These squalls are a good indicator of the true Arctic air coming in. Much steeper low level lapse rates develop as 850s tank.

AIFS has been more or less consistent for days. Upper jet dynamics look great but deep moisture peeling off to the east Saturday night and the wave’s fast progression should limit amounts outside of a mesoscale heavier band.

good luck with that

Re: February, most of the Gulf is still balmy so severe wx is gonna pick up in a hurry https://doi.org/10.1175/MWR-D-24-0016.1

It has consistently shown a modest snowfall for the mountains into VA Sunday-Monday, but it’s nowhere near a monster anywhere. After that it overwhelms the Southeast with cold/dry weather.

It's probably going to be hard to avoid a robust Southeast ridge in the extended, with high confidence that the Pacific Ridge (PR) dominates from the end of January through February - GEFS and EPS are both showing this. What could help earlier in the period is the Alaska Ridge (AKR), since that will dump Arctic air into the heart of the continent. Overrunning events may still occur, especially northern parts of the Southeast into the Mid-Atlantic, but it looks like most 00Z guidance further suppressed the storm track with the AKR pattern and Arctic cold overwhelming things later next week before a more significant warmup occurs. Curious to see if we'll be able keep the relatively cooler (or less warm) anomalies along the East Coast that have occurred in both December and January so far (last 60 days depicted at the bottom).

2.1” of snow/sleet at ATL and 0.25” of freezing rain so far.

GA closing in on 100k outages. Winds beginning to ease after the indicated peak gusts over the last few hours.

Definitely have a thickening glaze on everything elevated now after a little melting midday. Power outages have quickly surged on the NW/W side of metro Atlanta into northeast Alabama with some gusts of 25-35 mph. Good setup for freezing drizzle much of the night after the main precipitation shield exits, which is more efficient at accretion.

The Carolinas are increasingly under the convergent quadrant of the upper jet, which diminishes the lift needed to maintain the band of heavier snow. Low level dynamics will kick in this afternoon but the DGZ is too high up for most areas to see the snow rates observed this morning.

That has little to nothing to do with it. The jet dynamics are becoming more unfavorable with time, resulting in weakening frontogenesis near and above 700mb, which had been tapping into the dendritic growth zone earlier this morning. The bulk of our moisture with this higher up forcing came from the Pacific. Low level winds out of the E or SE are also bringing in drier air out of the weakening surface high.

3.1” here prior to the sleet we have now. Some -FZRA mixing in. Will be curious to see if the “unmodeled” snow cover will maintain freezing temps at the surface despite SE winds. Models seem to be handling winds ahead of the inverted surface trough well, as gusts of 25-35 mph are being reported in central MS.

No surprise there’s heavy snow occurring across Atlanta with this intense forcing from frontogenesis. Will be progressive but could pivot as it weakens over TN and western NC. http://moe.met.fsu.edu/banding/

Easy over. That’s a band of 1-2”/hour moving across south Fulton now.

Can see the delineation in precip types quite well on CC. Precip is sleet or mixed at first prior to saturation occurring and then flips to snow (N/E of ATL now), with the warmer air aloft evident in the south metro and along/S of I-20 in AL.