Winter Wx

No Rest from Old Man Winter

Miguel Pierre Winter Wx

Low pressure is now forming over Delmarva region this morning, will move well south and east of region today. A steady area light to moderate snow now over Southern New Jersey and Delaware could give those areas 1-2 inches. While the rest of the Tri-state area see more light snow showers and flurries, with any accumulation likely under 1 inch.

LongIsland.rad

Another shortwave and artic front, may produce few snow showers and flurries on Thursday afternoon and evening. Mainly north of NYC. The coldest airmass this week, will arrive on Thursday night and Friday. The NAM,GFS, ECMWF show 850mb near or below -20C Thursday night, early Friday. NW winds should relax by dawn and with some snow cover left, low temperatures in the single digits are likely for NYC area and near or below 0 for the NW suburbs.

12zNAMf66Some record low temps will be challenged on Friday. Especially for JFK and LGA. NYC and EWR look to be just out of reach. Temperatures will slowly rise into lower 20s in the afternoon. These are some record lows around for the tri-state area on Friday 2/28/14:

NYC 5 1934
LGA 12 1980
JFK 15 1950
EWR 1 1934
BDR 10 1950
ISP 12 2008

A weak shortwave coming out from SW may produce a period of light snow or flurries on Saturday. A bigger system coming out the Southwest US, is likely produce more significant wintry precipitation in the form of snow, Sunday into Monday.  Still several days away to hone any down specific details.

Cold Pattern Arrives, Storms to Follow

Miguel Pierre Long-Range Discussions, Winter Wx

The cold pattern that has been discussed for this week, has arrived. An artic front pass through overnight with some showers. As colder continues filter into region,  temperatures may fall back in the lower 30s and upper 20s. Before rising back into middle 30s this early this afternoon. Tonight will be much colder, with temperatures dropping into lower 20s in NYC and the teens for most of the suburbs. Tomorrow will be mostly sunny with temperatures rising into upper 20s or lower 30s for highs.

The storm for Wednesday, now appears will far enough south, it will just give us a light snowfall at best. We have seen storms this season trend stronger or farther NW, just inside 24-48hr. However, latest model trends show the shortwave energy along trough, that will responsible for spawning this storm, is more strung out Without this energy being more consolidated, the trough can’t sharpen, to tighten the baroclinic zone farther NW. There is also other polar jet disturbances, keep the height flatter ahead and behind this system. This results in weaker low developing along Mid-Atlantic coast and tracking well south and east of the 40/70 benchmark. I will still monitor this for any significant changes in handling shortwave energy and other features. But right now I don’t expect no more than a couple of inches of snow accumulation.

6zGFS57

Thursday and Friday will be high pressure will be control resulting in cold and dry weather. Then pattern will be more active, starting this weekend. The Polar Vortex will slowly begin to retrograde and with the MJO entering phase 8, the sub-tropical jet will become active with disturbances moving across the southern CONUS. There will also be high-amplitude ridge along the West Coast of North America. So anyone of these disturbance has potential to interact or phase with northern stream disturbances, and produce a significant storm for the Eastern US.

However details vary with each prognostication of every disturbance on the models from run to run. It’s important for everyone to not get infatuated with model solutions, at this point. Instead use pattern recognition, ensembles and trends to determine the probability of that solution occurring, without getting into specifics.  I will have more posts here this week about these storm threats.

Rain Today, Strong Thunderstorms Possible Friday

Miguel Pierre Severe Wx, Winter Wx

A frontal system and strong shortwave trough will give the region a period of rain from later this morning into this afternoon.  The rain can be seen on radar over PA. Temperatures aloft are enough for the area to only see rainfall from this event. However, surface temperatures may be slow to rise above freezing, due to the snowpack. Which could cause rain to freeze on surfaces. Especially north and west of NYC. Therefore, the National Weather Service has issued a Freezing Rain Advisory for NW NJ and Orange and Rockland Counties in NY. Rainfall totals are likely between .25″ – .50″ across the area. So no significant flooding is expected. However snow melt today may cause some ponding on the roadways. So wear waterproof boots. Rain should ending this evening.

Radar2A cold front will move through on Friday, with some showers and possibly some thunderstorms. SPC has places southern parts of the tri-state area in a 5% or 15% risk for thunderstorms with damaging wind gusts. Models don’t show any surface-based instability. So severe weather is not likely. But with a strong 500mb jet streak and some elevated instability there is potential for a forced low-topped squall line that produce wind gusts of at least 40mph. Temperatures will also likely rise into 50s ahead of this front.

day3prob_0830
gfsNE_500_spd_060These weekend will feature mostly dry weather, with a gradual step down with temperatures. Next week still looks much colder with a threat of more snow.