Saturday, December 10, 2016
Mid December update
12-18 - results...6.5" on grass 6" on deck and table. Generally, all models got the idea right - snow front end. They also got the 925-700mb temps close enough. They did not come close to surface temps.
12z yesterday sfc temp guidance for 18z
Euro - 34.1
GFS - 34
actual just went to 30.
Yesterday's 12z Temps for 15z today
GFS temp was 31.2
Euro temp 30.1
NAM Temp 31
Temps in C Precip via DXR
12z -5.2 .13
15z -3.6 .33
18z -1.1 .13
Closest runs were all on Dec 13
GFS 6z with 12z at -4.8 and 18z at 1.2 but .28" and 850s too cold at -2.8 at 18z
GFS 12z with 12z at -3.2/ 18z at 1.7 and .41" and 850s at 18z were -.2 which was closer
Euro 0z with 12z at -3.1/ 18z at 2.9 and .59" with 850s at 18z +.7 which was really close.
Some snow maps...12z 3knam, RGEM, 12k nam, GFS, Euro
12/15 - no real updates. Models eerily consistent. NAM is oddly lower, so thats a red flag, but 3-4" still looks good there. GFS/Euro/ GEM looking at 4-5". Still a chance a LP pops - but if its to our west, it doesn't matter. Still looking at 3-6 of snow, starting midnight or so, turning to rain around noon, perhaps as freezing rain. All rain by 2, which is 2 hrs later than modeled. Then it stops, drizzles, and the front comes through Sunday, with heavy bout of rain and possibly back end snow. Those details are still being worked out, but back end snows are fairly rare, so there needs to be a good case for it before pulling the trigger on that one. Some indications of a clipper type system on the 23rd could still bring a white Christmas.
Yesterday's snow amounted to about a slushy inch, but fell just before school so they delayed. We are expecting a dusting overnight with a cold front passing through and a LP passing to our east. Temps Thurs and Fri are expected to be around 20 as a high, with lows in the single digits. As a storm cuts to the lakes, or NY State, a warm front will swing through bringing warm air advection snows to the area. These typically hit quick and hard, then turn to drizzle and warm up. Only mitigating factor from me really being excited is not a lot to hold the cold air in. But, GFS and Euro are looking at about .6 qpf before 850 and 925 temps get above freezing. Some of that snow early on will have high ratios as its -5c surface and -12 c at 85- with a low and large dendritic snow growth zone. Early estimates would be a 3-6 inch snowfall.
12/10 First day it didn't break freezing.
Lack of computer making updates tough.
Opportunities exist -they show up, disappear, re-appear, turn cold, then warm.
The storm on the 11th-12th looks like mostly rain south of CT. Its overrunning ahead of a storm moving either over us or to our north. GFS trending colder, Euro has always been cold enough for snow. Northern CT could see 4-6. I'm expecting 1-3 here. There's no high to the north, but the cold ahead of it is pretty significant. Ground is now frozen, and expect it to remain so until rain, so there could be some freezing rain.
Accumulated snow map.
Then the 14th-15th storm appears to be going out to sea. I'd watch that one.
Then the 17th-18th another one shows up. Its waffling warm/cold. Current snow map plus the amount from the 12th.