Major ice storm on the way for Kentucky

[Whacker77]

I'm surprised no one has mentioned this, but a major ice storm is headed for Kentucky. The latest warnings from the Louisville NWS office says ice accumulations of .50 to .75 inches is possible from just north and west of Louisville to just south and east of Louisville. The NAM shows major accumulations of ice in that area and heavy snow north and east of the ice. The GFS shows the same situation, but less moisture with which to work. Regardless, winter storm warning for snow and ice are going into effect.

Right now, the consensus seems to be Louisville sees a few inches of snow before it receives around .25 inches of ice. Last night, it appeared the city was in line for as much as .75 inches of ice so hopefully the southward trend of the ice continues. I lived through the ice storm of January 2009 that crippled the entire state of Kentucky. It was a brutal experience as my power was off for six and a half days while temperatures dipped to zero at night. Almost 250000 of the 400000 customers in Louisville were in the dark. That equates to about 750000 people. I hate WAA.

We see our fair share wild weather here in Louisville, but ice is the one thing that scares me.

[clskinsfan]

Not just KY. TN looking at some bad icing as well.

[Ed Lizard]

NAM at LOU looks like sleet or graupel. Still should cancel school.

[am19psu]

Jackson, KY is better. E KY/E TN/S WV/W VA are going to get pounded.

[Ed Lizard]

Jackson, KY is better. E KY/E TN/S WV/W VA are going to get pounded.

When its winter and not severe season, the radio button for emagram is more useful.

Hotlinked images off the NIU site become red "x"s in about 3 days, I was uploading the emagrams for Foxboro on the big storm or not thread, but this event will be passed before the GIF files become useless.

[Whacker77]

I don't totally understand how to read those charts. Could someone provide a brief explanation?

[Ed Lizard]

I don't totally understand how to read those charts. Could someone provide a brief explanation?

The emagram is reaaly simple, and easier to understand for a potential winter situation. One looks at the normal model plot to indeed see precip is falling at a certain time, then, on the emagram, is dewpoint and temperature plotted as a function of height. This is a forecast from a model. Its the same data plotted on a skew-T, which is to help people evaluate severe weather potential, but on different scales.

On the Lexington NAM forecast, there is about 600 meters barely above freezing, hence, I would suspect only partial melting, and with the last thousand meters below freezing, I'd expect the partially melted snow to freeze back into graupel/sleet/snow pellets.

I'm an amateur, I just guess on P-type from the emagrams. What I will do, when looking at the regional GFS or NAM 4 panel on the PSU e-Wall look for the 850 mb freezing line, the shallower thickness lines if plotted, and the 1000-500 mb thickness lines, and if their is a spread between them, with the 850 furthest South, I start checking point soundings around and South of the 850 mb freezing line, suspecting a shallow cold airmass is in play.