Tuesday, December 31, 2013

Year End 2013

Remarkably, December is only -.6 off average and has 73% of normal precip, so still on the dry side.  Snowfall of 14 inches is just above normal.

DXR for the year was -1.4 per graphic below, but oddly was one of the few stations below normal for temps.
DXR was close to normal for precip, certainly not a drought year, although the last few months were dry.  Thunderstorms drove the difference across the state.
Snowfall was slightly above normal, with Bridgeport scoring the most in an unusual winter

source:  accupro climate data

Monday, December 9, 2013

Mid Dec

12-16  most consensus in models for tomorrow's clipper. 2-4 inches with a slight chance of 6". Should be quick. Timing is tough as snow starts around 7am and picks up around 10-12. Then it's over by 2.
12 nam precip .28
12z gfs precip .23
0z  ecmwf precip .14
Cmc is .5 graphically.

12-15. Started at daybreak, 2" by noon, then a lull. 6" by 2am when it switched to zr for an hour or so.  Most interesting aspect was the temp drop from 19 at daybreak to 16 for all the daytime.  Temps did go up to 30 overnite, but the models were off by at least 5 degrees for most of the storm.  Mental note that with strong high in place, models overestimate temps.  Also most precip came through before the 925 line made it into the area.

12-13
0z Nam all snow, in the 12 inch range (see below)
6z NAM is all snow with about 1.25 qpf
 0z euro has .65 qpf before the next 6 hrs mixes/rains, map has 6 inches
0z gfs had us in 6+ range on snow map
6z gfs has .57 qpf before mixing issues
CMC has .5-.75 - brings low in closer, but keeps 850 cold until most of precip passes
UKMET farthest north - brings primary to pa, forms secondary over us.  But front loads precip
I'm not buying the warmup past freezing though at the surface.  Could be rough period of sleet/freezing rain. Hoping that the moisture moves in faster than the temp change, as it usually does.
NWS has 6-10 and winter storm watch
Euro

GFS

NAM


12-12
0z Euro - cold south, stretched out over two days. at 12z sat with .03 qpf to 0z Mon with .03 qpf. In between .44 qpf total, all snow. 850's get to -.4 at the warmest, snow map with 3-6
0z gfs - similar to Euro, stretched out lp. Ends quicker and has more qpf per 6hr. Brief rise above 0 at 850 causes mix early sunday, surface temps not over freezing. qpf .5-.75 snow accum 3-6
6z gfs is colder, with temps at 850 barely making it over freezing (0.3). Wetter with .77 qpf with .28 of that above freezing at 850, but below at 925, so sleet likely. Snow map with 6-9 inches. Precip from 12z sat to 18z sun.
0z NAM - still far out for NAM but it has a very different solution. It keeps the northern branch stronger, makes the coastal stonger too, but hugging the coast, torching the 850 temps to over 5. Whole of NE gets rain, but only after front end snows. It brings in snow 12-15z sat, keeps it light until 0-3z sun, at 6z sun, the 850 line moves tot he ct/ma border, by 9z its into VT. Seems too fast. Total qpf around an inch. Snow map of 3-5 inches for most of the area.
6z nam - same time frame as 0z, a bit cooler at 850, 850 line is over us at 6z sun. LP Runs right along li coast. QPF is .75-1 north of 84, 1-1.25 south. 4-6 inches on snow map
12z nam - starting to get colder. Snow map with much of CT over 6 and parts over 9. 850 line never lifts out of CT, stalls north of 84 though. QPF is down with most of the state .75-1 and only the far E slice of CT and RI getting 1-1.25 12-11
GFS and Euro still in agreement with weak system - qpf over 6 hrs never greater than .17.  0 lines are around 0 at their warmest, with the 18z gfs going to .1 for less than 6 hrs with little precip.  Based on qpf and a 15:1 ratio, its 6 inches out of both.  CMC continues higher output - .5 to .75 w ct, with .75-1 east ct. NAM came in looking good at 18z, but weak 1008 low off Cape may, UKMET at 72 with tx low, 96 over BM, only 1004


Morning
GFS, CMC, Euro, DGEX all on same track - LP drops from the plains, TX, LA, AL, GA, off NC/VA.  Euro is slower at that point, CMC is closer to the coast, GFS is faster.  All with mslp of 1012, to 1008 to 1004 to 1000.  None have any solid amount of precip. .4qpf for the area now.  Odd alignment of model solutions. Euro is all snow, GFS has some brief mix, CMC is half/half, DGEX has brief mix.

UKMET is faster, weaker and farther north, but only have h96 and h120 data.


CMC has most QPF .75-1.0

 12-10
gfs
0z - LP in tx, reforms in AL, goes up coast, over NJ to LI to CCOd as 996 low.  Snow to mostly rain
6z LP in tx, doesnt really organize well, moves in a broad area up to NJ as 1000, ccod 996, colder, probably equal snow and rain
12z LP in Tx, falls apart, reforms off NJ, but as a secondary with another low over wny. Much colder, nearly all snow, over 12 inches.
18z - same  - takes LP over TX, turns into blob, reforms this time closer to LI.  Probably half snow, half rain.
CMC 12z takes a 996 low west of Buffalo, forms new 1000 lp off NJ, tracks inside BM.   Very close to all snow - right on the line for a portion of it.

0z euro respawns off NJ to over CT.  Snow to mostly rain
12z Euro - lp in panhandle tx, falls apart, reforms off Delmarva, deepens rapidly, hugs coast off ACY, then goes inside BM as 988 low
Euro is more amped, gfs a bit flatter.
UKMET is weaker, takes double barrel approach - 0z has secondary on the coast, 12z out east of BM.  
.DGEX rides up the apps to right over CT, as does NAVGEM
GFS Ens have the low coming up out of tx to buffalo, hinting at secondary

12-9 -snow for tomorrow.  Euro with .19 qpf, GFS .4 and NAM .38.  Trending in a higher manner.  Could see 2-4 inches, NWS looking for 1-2, but even the Euro output is 2 inches.  Euro ens are also over .25 Its a quick and light event, but look for a band or two which may surprise.

Next down the pike is the 14th - 12z euro is a bit close to the coast, bringing mix.  0z euro was at the BM bringing all snow, and a bunch of it.   12 gfs brings storm right over us, mostly rain.  6z and 0z slides wave off obx, limited moisture, all snow. 18z GFS track is odd, it brings a low up the oh valley from the gulf, amorphously slides it due east, where it reforms off NJ and just about moves e over LI.  Snow to start, then cold rain.  0 line at 850 over mass through most of the precip. DGEX brings it up the apps to right over nyc. CMC brings one low over or inside BM on the 14th, but cold enough for snow, then another more potent on the 15th, but much warmer, borderline rain.  12z UKMET slides low from TX at 120 to S of the BM on 144.  This one is up in the air, but GFS usually doesn't adjust east and any phasing probably just makes it stronger and further west.

Storm 3 - could be the one! (spoiler, it was)

 2/9  Set up is an upper low over TX that heads northeast into TN valley and then transfers off the coast. At the upper levels, there's ...