Monday, January 10, 2011

Jan 19th next?

1-18 reality. No school. At least 2 inches of snow, followed by 6hrs of sleet and a few hrs of freezing rain.

1-17 - late day skiing - problem is temps were 10deg higher than forecast overnite. Todays high though was 22. At 9pm, its 21, so not much dropoff. Getting to 32 from 21 with a se wind is fairly easy. Complicating that is a dew point of 5, so the precip approaching in S NJ now, should lower the temp more. Further complicating is that the LP is forecast to be a bit stronger and further east, just inside BM, which should change the surface winds to ne and n and keep the remaining cold air in. There is a decent probability that we end up with 6 inches before it changes to freezing rain. I do think surface temps make it to 34 on Tuesday, later in the afternoon, but by then the precip is mostly over. It looks like the precip is already early as it is. My concern with WAA events always is that the precip arrives early and the temps rise late. Prediction is 3-6, maybe even 8 if the precip gets in early enough, with 4- 6hrs of freezing rain

1-16 Wintry mix still expected, with possible front loaded frozen N and NW of NYC

Solutions trending colder at 12z
Euro 0z 850 line is further south, at it highest in vt, than the 12z yesterday. Todays 12z run maxes out the 850 temp over dxr at 1.6. Surface temps still way high for euro, probably due to its insistance on se winds compared to other models. Track looks like obx to ack on the 12z run today. This is shifted east. It also doesn't develop the coastal as much or as fast as the gfs

CMC -both runs drive the low up the coast right over us, which explains its warmth

0z ukmet brings coastal inside obx to inside bm. pushes 850 line into mass. 12 z can't figure out if it wants the clipper or the coastal to win and blasts warm air north.

GFS - 12z run does pump 850 temps over 5 at 0z wed, with surface temps staying under 35. Over .5 of its .91 will fall with surface temps under 32. Its storm track is from inside obx to inside ack. Weak, 1004 area of LP. Over an inch qpf, but more over eastern mass.
6z run has 1004 lp at inside delmarva going to 996 over cape cod bay. Over 1" qpf
0z has over an inch of liquid - inland low dominant, 1004, until a 1004 low forms just s of LI. This means south/east winds, warmer.

Nam - 0z nam forms low well off coast and that doesn't dominate until it reaches here, bringing warmer winds. Drier with only .5 precip
6 z develops low inland in VA, much quicker dev and coastal dominates, should be colder at surface. Bulk of precip to our west? NJ gets 1.75, we get 1.
12z - surface temps make it to 33. 850 goes to 4.2 but only after it stops preciping - supports front end frozen. Drier again, bulk of precip to the east, only .5 falling in dxr. Interesting that it keeps the two storms separate, with the coastal developing, moving out and then the inland instead of moving ne, moves e over our area bringing rain.











1-15

GFS in each run has shifted east and colder, with more energy in the coastal than the primary. Latest 18z run shows it barely making it above freezing at the surface in DXR, and not making it above freezing for two weeks at POU. This looks like a classic front loaded cold storm. Question is whether its snow, sleet or freezing rain.

NAM is way warm, with nearly all precip falling as rain as surface temps stay around 35 and 850 temps go above 5c

Euro 12z has much of the precip falling aloft as frozen, but its surface temps are way too warm. Note this morning it was off by over 10F. Its also drier with .54 falling, with .15 as frozen. Its 0z run brings L through PA to coast, then north. 12z goes up west, with only a weak surface reflection.

With accupro models having issues, the ukmet only goes to 72, looks similar to gfs and colder.

12 cmc has the 850 line all the way into canada, despite taking the low from obx to BM. This is opposite of the 0z which had the low right over us, but the 850 line in only as far n as the ma/vt border

1-14 Still questions on this storm

GFS for last few days has been sending the storm to the lakes, with a warm front extending over us bringing warm air advection snow and changing it to rain, or more likely, drizzle. While it has a surface reflection low, it doesn't do much with it. The 6z run today actually keeps the temps right around freezing aloft and at the surface and the concern with that would be that its underdoing the aloft temps and overdoing the surface, leading to an icing situation. Total qpf under .5 for most of the runs. This solution is least likely, but most favorable since it limits the precip.

Euro has been bullish on the northern storm transferring to a coastal. Yesterdays 12 run brought the low from inside Cape Hatteras up through Rhode Island at 984mb. Normally, this is a monster snowstorm for Western CT and the Hudson Valley, NNJ and rain NYC east and along the shore. This solution too would have front end snow and back end snow, but wouldn't dry slot like the gfs, and its QPF is 1.5 inches, which is enough to cause some problems. The 0z run today still has the northern branch going through the lakes, like the gfs. But it brings a lot of moisture up from GA and the GOM and forms the Low in NC and brings it up the coastal plain right over NYC at 1000mb - so its weaker as it doesn't phase until northern new england. Still has front snow, but less on the backside. Temps would be near 40 both aloft and the surface. Precip is further west, with E PA getting the bulk, and its less, 1.5 with 1 inch by us. I think its moving to the GFS solution and will pull a bit further west this afternoon.

Other models:
UKMET - two systems, one goes to the south, one to the north
DGEX 6z has no real organized system. most of the energy to our south. Yesterdays 18z run was similar to the euro in that a coastal plain storm forms going just to our SE and bringing a lot of rain.
0z CMC has a central APPs runner with some front end snow, but mostly rain. Similar to Euro with 2 inches over PA, but 1.5 in our area. Yesterdays 12z run had a look similar to todays GFS - but stronger southern low, sliding south of us, bringing almost all snow.



1-12

Wide range of solutions for this event.
0z euro cold and out to sea, 12 z had major storm hitting, OBX to ACK, but had temp issues with DXR on the 0 line at 850.
Long range cmc was out to sea
DGEX 6z had the main low going obx to ack, but was even warmer than euro
0z gfs had split north and south branch storms, one going north of us bringing the warmth up and the southern going south of us, looking like a fropa. 6z ditto. 12z is really odd and will ignore.


Watching the gfs around the 19th - its 228 hrs out, but showing storm in the area.
Euro is more surpressed, for now, and has a fropa instead, with temps warming prior, bringing some rain? Looks odd.

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