Hurricane Agnes

Now getting plain rain although not enough yet to tip the bucket. Temp still holding at 34 but dp continues to creep up and is at 29.

My Upper Darby sis just texted that she is getting sleet with flakes mixing in and a temp of 33. The precip. just started up here and am getting pingers with some rain mixed in, and it's 34 with dp 28.

Leading edge is just overhead here but getting virga as the air was pretty dry just ahead of it. It's starting to moisten up now and temp is 34 with dp 27 and overcast.

6z GFS has some token stuff on the ground in Philly metro (I think the NBM is discounting this run at the moment).

Don't know if I need stronger coffee but it looks like the 6z GFS just made a slider out of the 12/23 storm (suppression?) and now it is OTS.

I created an OBS thread for the event - We are starting out at or slightly below freezing IMBY, which is actually a bit "warmer" than the past couple mornings (some due to the cloud deck vs previous mornings).

Current obs - Tem 32 with dp 24 and overcast.

That's what our Streets Dept. here in Philly says - it's done to keep the snow from sticking to the road surface although it also lowers the freezing point of any melted precipitation as long as there is a decent concentration of it and no heavy rain to wash it away. But then they also claim they don't plow here until there is supposedly 3" or more that has accumulated on the roads and often by then, the damage is already done after the accidents pile up from slipping and sliding cars. And if you have like what is forecast here - heavy rain - (and worse, rain on either end of the event time frame) putting any type of treatment down means it all gets washed away. So I guess it's all in the timing of it with a focus needed on getting the overpasses and bridges treated well.

18z GFS has a little something down here along I95 but the kicker is the last panel a couple days before New Years. lol

I was just up your way around the time you posted this (at Assi Plaza) and saw the tell-tale "storm incoming" hazy deck of cirrus with sun trying to blaze through. Actually made it up to 40 as a high (degree warmer than yesterday's high) after a low of 27. I saw Springfield Township did some brining earlier today. Am thinking it's more to reduce the potential for black ice with the event supposedly getting going during morning rush after a cold overnight and antecedent cold roads... plus a forecast of some kind of mix to start (including IP) for down this way. I know they use their own trucks to do it. Also wanted to throw the 12z Ukie in for its snow forecast for this upcoming event through to Saturday.

18z hi-res EC (only up to 90 hours) shows the low really tucked in but then still wraps cold air in over I95 (but I expect it means some kind of mix).

To compare - the 18z NBM -

18z GEFS showing an obvious north focus for the greatest amounts of frozen by the weekend.

Could be a mid-range blip. Will have to see what the 0z says... 2009 - 2010 was an El Nino winter but anytime you have some kind of tucked coastal, it's gonna wrap in too much warm air just inland. If you get a juiced up clipper with enough intensity and antecedent cold air, you could get walloped as the ocean moisture wraps in around the low and loses the battle with the cold air as the low approaches the coast. This thing almost looks like an overrunning precip event pulling moisture out of the GOM first before it spins something off the coast.

It's not just La Nina and a "warm" ocean. It's still December and unless there are some really anomalous cold outbreaks early in fall, the ocean isn't really going to hit it's coldest temps until well into February, which is the typical lag.

18z GFS is depicting some wrap-around snow as the low departs Friday/Saturday. As some quick obs, I made it up to 41 today after a low of 33. Had a little drive-by rain shower early this morning for 0.01" and with 0,11" yesterday, ended up with a 0.12" 2-day total. Skies were unsettled in general today with the sun fighting to appear and then giving up. Currently 37 with dp 31

Finally catching up in the other threads. Excellent pic, framing, and timing! The kind of pic that people make into posters.

Some RERs for record warm low at some sites yesterday - My own "low" for Wednesday was 51 just before midnight last night. My high for yesterday was 55 and I got another 0.01" of leftover rain for a total of 0.12", and 0.98" as a 2-day event total. It's currently 48, partly cloudy with a Full Cold Moon setting, and dp 46.

My Monday high was 46 and yesterday's was 56 after a low of 47 and 0.86" of rain. This morning netted an additional 0.11" of rain so far (for a 0.97" 2-day event total), with a mild low of 53 so far. Mt. Holly noted that multiple CWA climate sites may tie or break record high mins for today (I suppose dependent on the timing of the cold front later tonight and bleeding in of that colder air before midnight) - I was surprised not to see fog earlier this morning - mostly mist - BUT the fog has rolled in now and is under 1/10th of a mile in places. It's currently 54 with dp 53 and foggy/misty.

Ended up with a 57 high Saturday, followed by a 43 high yesterday after a low of 28. This morning the bottom fell out with a low of 23 and scrape-able frost on all the cars. It's currently 24 with dp 23 and a deck of cirrus overhead. In other news, both the GFS and EC progs for the MJO don't inspire a potential for a major cold dump during that 3rd week of December even with the NAO fairly negative during that period, although a couple GEFS & EPS members appear in phase 8 for this week. (Ensemble GFS) (Operational GFS)

Well remember that everything is pushed a couple months later. So spring is the new winter. You'll see the verification in March. Cold front did start advecting cooler and drier air in. Currently down to 50 with dp 39.

The line came through here giving me another 0.18" of rain (no convection though) for a total of 0.67" for that 2-round event. The temp didn't drop off much yet as I think the front is still a bit west of here. Currently misty and 55 with dp 53.

Sun popped out about 2:30 pm an the temp is probably sitting at the day's high (which is 57, with dp 54 so far) before the cold front comes through. There's some kind of line to the NW that might be associated with the front.

You are definitely in Heat Miser's kingdom (although further north up in the mountains where Flagstaff is, they do get frozen precip)! I ended up with a high of 47 Tues, and of 46 on the last day of November after a low of 37. And December did start out December-like with highs/lows of 41/30 and 44/26, along with some dps that were in the 20s. This morning's low was a big non-diurnal change with a 43 just after midnight and the temp rising slowly ever since. So far with the initial round of rain pretty much moving towards the coast, I got 0.49" from it and it's currently an overcast and misty 55 with dp 54.