Blizzard of 93

Certainly a few things to resolve out towards NY Eve… The 0z Euro says congrats Atlanta, while the 0z GFS says congrats PA. The extent & impact of the blocking will continue to throw models fits for the at least a few more days.

Certainly a few things to resolve out towards NY Eve… The 0z Euro says congrats Atlanta, while the 0z GFS says congrats PA. The extent & impact of the blocking will continue to throw models fits for the at least a few more days.

LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Overrunning precip on Monday night and Tuesday will be mainly snow overnight, but could turn to rain in the Laurels and central mtns before morning. As that change would occur, there is a strong possibility that some ZR will occur. We will continue to mention ZR in the wx grids and show a small patch of ice accum in the central mtns late Mon night and early Tues AM. We have 3 more periods to become more confident in the forecast, but may eventually need a wint wx advy for that time frame. Since there is expected to be SN at first and temps hovering in the 30-32F range for much of the CWA late Mon night and early Tues, the changeover to RA could occur without creating dangerous ZR. The highest threat of ice accumulations appears to be around AOO and UNV before sunrise. QPF will be almost nothing on the MD border, but a widespread 0.20" in the nrn half of the CWA. Most of that would be falling when it would be SN. SLRs are very low (<10:1), and accums will be a max of 1-2" with the highest accums in Tioga & Sullivan Cos. A coating (<1") is expected for much of the area before the SN turns to RA. The precip should lift off to the NE and be over around noon Tues. Temps max out in the upper 30s NE and near 50F between AOO and HGR. Gusts will increase Tuesday evening to the teens and 20s, but drop off through the day on Wed as high pressure moves in.

Here is CTP for Monday night/early Tuesday for the Harrisburg area. Monday Night Snow likely before 4am, then rain and snow likely. Cloudy, with a low around 30. Calm wind becoming southeast around 6 mph after midnight. Chance of precipitation is 60%. New snow accumulation of less than a half inch possible.

6z GFS still supports the idea of a little Tuesday am Christmas Eve Eve snow with showing around 1 inch in the LSV & near 3 near Williamsport.

0z GFS keeps even the LSV in the game for the chance of a little snow on Tuesday.

JB says there is a 10 to 15 day lag after Europe gets cold until it gets cold in the east. He believes the trough will back in from the North Atlantic into the east.

0z GFS & 6z GFS are still showing interesting looks for potential Winter storm chances towards end of the month into the first few days of the New Year. The onset of Blocking really throws models fits until they can see the full impact of the -NAO. If it sets up just right, we could be tracking a meaningful potential storm. The 0z GFS showed this beauty of a chance at the end of its run.

The 18z GFS got more interesting for the Tuesday am weak wave chance. This run gets 1 to 2 inches of snow into the LSV.

Wild weather day! Heavy rain, followed by 2 hours of relatively warm sunshine, then more heavy rain & wind. Then, Snow showers when leaving my office in Harrisburg & snow showers in Marysville with a light dusting on car tops.

The 0z GFS brought back the potential chance for an end of the month coastal that is influenced by the -NAO.

6z GFS has some light snow & mix on Tuesday.

Longer term, the GFS & Euro both are showing the potential of a more significant coastal type of storm towards New Year’s in response to the -NAO blocking pattern that looks to become established the last week of tye month.

The overnight models are still trying to resolve the potential of a weak wave around Christmas that could deliver a mix for many of us.

It is truly remarkable that MDT is running 9 degrees below normal temperature for the month through 12/16. What a cold stretch, along with above normal snow for the season to date at 4.7 inches. Great start to the season & hopefully we are on our way to a good Winter that is overdue for many of us.