Blizzard of 93

Detailed & entertaining Forecast Discussion from CTP on the Sunday snow chance. KEY MESSAGE 2: Continuing to monitor the potential for winter weather on Sunday. Over the next few days, a closed low currently off the NorCal Coast will drop southward as it opens a bit, and take a turn to the east after reaching the Baja Peninsula. The trough swings east over the srn US, and eventually develops a sfc low as Gulf moisture is incorporated. Timing and occurrence are fairly well- agreed- upon at that point. Mud gets thrown onto the crystal ball as divergence in track of the low and depth/residence of the cold air over the ern US are seen in the latest deterministic forecasts. If precip gets into PA, the hints are still there that the air will be cold enough in PA to have some snow at first, but not a slam dunk certainty. As alluded to, the GFS and ECMWF, and ECMWF-AI latest runs are keeping the low track flatter. That would make much, if not all, of the precip miss PA to the south. But, ensemble means from both sides of the pond and nord de la frontiere make precip well into PA with the CMCE mean pushing the most QPF into PA - and much farther north. The latest NBM guidance has trended lower with PoPs, which matches recent trends in guidance. The best chance for precipitation is currently across southern PA. Additional shifts/modifications are likely and we will continue to keep an eye for a more consistent/longer trend to make tweaks to this weekend`s forecast.

Thanks, I didn’t realize that it only went out to 84 hours.

18z EPS is way too close to write anything off at this range.

@mitchnick or anyone else have the 18z Canadian?

Here is the 24 precip on the 18z EPS.

18z EPS is way too close to write anything off at this range.

Agreed, the Sunday chance is still way too close to write off at this range. The 18z Euro was a close call & grazes southern PA with some light snow this run. It was not far away from something more.

MDT only needs 9 inches or so more of snow to reach seasonal average of 30 inches by early April. We still have 6 realistic weeks to score, so it’s certainly within reach.

6z EPS & 6z AI EPS are on board for the Sunday into Monday snow chance. Reminder that the regular EPS only goes out to 144 hours, but the AI EPS goes out up to 15 days.

The 6z Euro just made a good change & is now on team snow chance for Sunday st the end of its 144 run.

0z Canadian is still on team CTP snow chance for Sunday.

@mitchnick I liked the look at the end of the 18z EPS as well & think it would have delivered a decent front end thump for southern PA on to the north if the run continued. 6hr snowfall on 18z Eps at 144hrs. Nothing in our area before that hour.

My lean right now for this Sunday is a 3 to 6 type of front end snow thump that mixes or changes over depending on the final track. I think that the chances of a high end event are diminishing, but I think a low end Warning to Advisory level snow are still on the table for many of us.

Way too soon for that. Lots of options are still on the table.

Here are CTP’s thoughts on the Sunday Winter storm chance. KEY MESSAGE 2: Risk managing potential for Valentine`s Day weekend storm Aside from the 09/12Z GFS to some extent, an ensemble consensus including ECMWF, CMC, NBM, and AI runs would lean toward an increasing potential for wintry weather arriving by the second half of Valentine`s Day weekend. That said, there is still plenty of time and space between now and then. Wintry weather/impacts, particularly details surrounding how much and what ptypes, are uncertain/unclear. Confidence right now is on low side, but the potential certainly exists and will need to be monitored in the coming days.

18z AI EPS main issue is lack of good precip getting near most of the region.

The lower snow totals on the 18z AI EPS are mostly due to a south & east track cluster and lower precipitation totals that held down snow amounts on most members. It basically followed the Op AI Euro this run.

6z GFS & 0z Canadian both have significant front end thumps of snow this run for CTP on Sunday, while the Euro has an icy start. This will be a long week of tracking…

18z AI EPS snow map

More from the 18z AI EPS

18z AI EPS looks solid with a good clustering of low tracks jumping to the coast.

The trend is our friend in CTP … Long way to go, but good to see the Ops at 12z all showing a storm in our region this run. Details TBD…

Fake fake news. Every model snows on us next weekend at least to start.

Agreed, this season has featured many nights in the single digits, but I haven’t been able to get to below zero. Last January’s -2 is still my coldest temperature of this decade.