Jeff Smith's Probable Cause

Soaking Rain For Tomorrow Night

While we have a significant rain event on the way for late tomorrow into tomorrow night, there may be some interesting weather tonight in parts of the area.  There is a lead shortwave that'll pass through during the pre-dawn hours, and this can spread in a bit of light rain or perhaps a light mix into the area very late tonight into early tomorrow morning.  The reason that I mention a mix is that temperatures will fall into the 30s overnight, and even just below freezing in some of the suburbs.  So don't be completely shocked if you wake up to a couple of raindrops (or even ice pellets or snowflakes N&W)! 

We'll probably have a break when it's just cloudy and not precipitating during the midday hours tomorrow.  Steadier rain will develop though, primarily late in the afternoon.  Temperatures will probably stay in the lower 40s during the day, and we won't get our official high until tomorrow night.  That's the when the rain will really start coming down.  The models have trended wetter, and there is a high likelihood of a half inch to an inch of rain tomorrow night into Friday morning.  While no widespread flooding issues are anticipated, some areas could exceed an inch of rain from this system.  Lifted indices (instability) would indicate that thunder is not out of the realm of possibility during some of the downpours! 

Rain will come to an end at some point Friday morning, and it may take until noon for the rain to wrap up on eastern Long Island.  The breeze will pick up a bit and there will be a few breaks of sunshine by late in the day.  Typically, temperatures would fall behind a system in late January.  That is not the case on Friday!  Guidance is suggesting that highs will reach the lower and middle 50s.

The weekend is looking pretty quiet at this point.  There were earlier worries about a wave of low pressure just missing us to the south late Saturday.  That system now looks like it'll be even farther south and weaker, so Saturday would just feature some clouds and sun, along with continued mild temperatures in the upper 40s.  A colder air mass will be moving east from the Great Lakes, but it probably won't get here until Sunday night, along with a flurry or two. 

Quiet, Then Questionable

The snowpack from Saturday's storm has been almost completely demolished by the rain and warmth of the past 36 hours.  Slightly cooler air will work in overnight, dropping temperatures down to near freezing in the city, but 20s in the outlying areas.  Tomorrow will certainly be a cooler day than today was, as highs only get into the lower and middle 40s, but that's still above average for this time of year. 

An upper level low situated over Texas will throw a piece of energy (but not all of it, and that's important) in our direction for later Thursday.  There may be a peek or two of sun to start on Thursday, but clouds will rapidly increase and rain should begin by or just after dusk for most areas.  This will be a rain event for the majority of our area, but with temperatures marginally cold enough (and cold air marginally deep enough) north and west, the precipitation can begin as a brief period of snow over Sullivan and western Ulster Counties.  I'd give it about a 30% shot at getting one inch of snow over the higher elevations of Ulster County. If it does begin as snow, it would quickly change to freezing rain and then rain in these locations.

This will probably be a quarter to half an inch of rain event for much of the area, with only a 20%-30% chance of exceeding a half inch.  Some of the latest model trends would suggest that because this comes in as just a small piece of energy from the southern system (and not the whole thing), rainfall may be gone by dawn on Friday, with the exception of Long Island and parts of the Jersey Shore. 

The fact that energy is left over in the southeast US beyond Friday (which I buy) makes for an interesting weekend forecast.  At the very least, we'll have to watch a wave of low pressure off to our south on Saturday just as colder air is seeping in.  I'll have more details on that in the coming days! 

NYC: 2 to 1 Odds of Getting More Than 3" Tomorrow

I've compiled the latest probabilities, and these will help to explain why the 3"-6" zone has been creeping farther south.  Everything still looks on track for timing, etc.  First flakes will fall near the Delaware Water Gap around 2AM and then rapidly spread east from there.  The storm will come to an end early tomorrow afternoon, making it about a 12 hour affair.  The heaviest snow should be around daybreak, with visibilities down to about a half mile or so in many locations.  Rain will mix in along the Jersey Shore and the south shore of Long Island, limiting accumulations in those areas.  That being said, this will be a mostly snow event for the majority of the area.  The sweet spot for snow will likely be over Sussex County, NJ, where the ratios will be good and they'll be far enough south to get into the best moisture. That area has the best shot of 6"+.  Here are the probabilites of exceeding 1", 3", and 6" benchmarks in selected locations.

New York City (Central Park):

Chance of more than 1":  91%

Chance of more than 3":  67%

Chance of more than 6":  5%

Danbury, CT:

Chance of more than 1":  86%

Chance of more than 3":  81%

Chance of more than 6":  5%

Bridgeport, CT:

Chance of more than 1":  86%

Chance of more than 3":  81%

Andover, NJ:

Chance of more than 1":  91%

Chance of more than 3":  86%

Chance of more than 6":  29%

Belmar, NJ:

Chance of more than 1":  76%

Chance of more than 3":  29%

Caldwell, NJ:

Chance of more than 1":  91%

Chance of more than 3":  81%

Chance of more than 6":  14%

Lakehurst, NJ:

Chance of more than 1":  71%

Chance of more than 3": 24%

Morristown, NJ:

Chance of more than 1":  91%

Chance of more than 3":  81%

Chance of more than 6":  14%

Newark, NJ:

Chance of more than 1":  86%

Chance of more than 3":  62%

Chance of more than 6":  5%

Somerville, NJ:

Chance of more than 1":  91%

Chance of more than 3":  67%

Chance of more than 6":  19%

Sussex, NJ:

Chance of more than 1":  91%

Chance of more than 3":  81%

Chance of more than 6":  24%

Teterboro, NJ:

Chance of more than 1":  91%

Chance of more than 3":  67%

Chance of more than 6":  10%

East Hampton, NY

Chance of more than 1":  86%

Chance of more than 3":  43%

JFK Airport

Chance of more than 1":  86%

Chance of more than 3":  48%

Chance of more than 6":  5%

La Guardia Airport:

Chance of more than 1":  91%

Chance of more than 3":  67%

Chance of more than 6":  5%

Islip, NY:

Chance of more than 1":  86%

Chance of more than 3":  43%

Montauk, NY:

Chance of more than 1":  86%

Chance of more than 3":  43%

Monticello, NY:

Chance of more than 1":  91%

Chance of more than 3":  81%

Chance of more than 6":  19%

Orange County Airport (Montgomery, NY):

Chance of more than 1":  91%

Chance of more than 3":  81%

Chance of more than 6":  14%

Poughkeepsie, NY:

Chance of more than 1":  91%

Chance of more than 3":  81%

Chance of more than 6":  10%

Republic Airport (Farmingdale, NY):

Chance of more than 1":  86%

Chance of more than 3":  43%

Stewart Airport (Newburgh, NY):

Chance of more than 1":  86%

Chance of more than 3":  81%

Chance of more than 6":  14%

Westhampton Beach, NY:

Chance of more than 1":  86%

Chance of more than 3":  38%

White Plains, NY:

Chance of more than 1":  91%

Chance of more than 3":  81%

Chance of more than 6":  5%

 

 

 

 

 

 

 

 

 

Update on Saturday Storm

You'll notice that the trend is upward for snowfall potential on Saturday.  Here are the latest numbers. Again, these are the probabilities of snowfall exceeding certain values.

 

New York City (Central Park):

Chance of more than 1":  86%

Chance of more than 3":  38%

Chance of more than 6":  10%

Newark:

Chance of more than 1":  86%

Chance of more than 3":  38%

Chance of more than 6":  10%

White Plains:

Chance of more than 1":  95%

Chance of more than 3":  62%

Chance of more than 6":  10%

Montgomery, NY:

Chance of more than 1":  100%

Chance of more than 3":  86%

Chance of more than 6":  33%

Poughkeepsie, NY:

Chance of more than 1":  100%

Chance of more than 3":  81%

Chance of more than 6":  33%

Monticello, NY:

Chance of more than 1":  100%

Chance of more than 3":  91%

Chance of more than 6":  67%

Islip, NY:

Chance of more than 1":  76%

Chance of more than 3": 24%

Chance of more than 6":  5%

Bridgeport, CT:

Chance of more than 1":  95%

Chance of more than 3":  67%

Chance of more than 6":  14%

Danbury, CT:

Chance of more than 1":  100%

Chance of more than 3":  86%

Chance of more than 6":  19%

Belmar, NJ:

Chance of more than 1":  38%

Chance of more than 3":  14%

Lakehurst, NJ:

Chance of more than 1":  33%

Chance of more than 3":  10%

Teterboro, NJ:

Chance of more than 1":  91%

Chance of more than 3":  48%

Chance of more than 6":  14%

Morristown, NJ

Chance of more than 1":  91%

Chance of more than 3":  57%

Chance of more than 6":  14%

Somerville, NJ

Chance of more than 1":  91%

Chance of more than 3":  57%

Chance of more than 6":  14%

Sussex, NJ:

Chance of more than 1":  100%

Chance of more than 3":  81%

Chance of more than 6":  24%

Caldwell, NJ:

Chance of more than 1":  91%

Chance of more than 3":  62%

Chance of more than 6":  14%

 

Snow, Then More Snow

We have a dusting of snow on the way for this evening for many areas, especially north and west of the city.  The more significant storm is on tap for Saturday though, and I'll be concentrating on that for this post.  I've compiled some probabilities of exceeding 1", 3", and 6" of snow.  Remember, these are the chances of getting more than the specified amount.  Keep that in mind!  The first flakes will move in during the predawn hours of Saturday morning, with the steadiest snow probably just after daybreak.  The storm winds down during the early afternoon, with some mixing along coastal areas before ending.

Here are the probabilites for the Saturday storm for various locations:

New York City (Central Park):

Chance of more than 1":  86%

Chance of more than 3":  33%

Newark:

Chance of more than 1":  86%

Chance of more than 3":  33%

White Plains:

Chance of more than 1":  86%

Chance of more than 3":  48%

Montgomery, NY:

Chance of more than 1":  95%

Chance of more than 3":  86%

Chance of more than 6":  19%

Poughkeepsie, NY:

Chance of more than 1":  95%

Chance of more than 3":  81%

Chance of more than 6":  10%

Monticello, NY:

Chance of more than 1":  95%

Chance of more than 3":  91%

Chance of more than 6":  57%

Farmingdale, LI:

Chance of more than 1":  57%

Chance of more than 3": 14%

Bridgeport, CT:

Chance of more than 1":  91%

Chance of more than 3":  57%

Danbury, CT:

Chance of more than 1":  91%

Chance of more than 3":  81%

Belmar, NJ:

Chance of more than 1":  48%

Chance of more than 3":  10%

Lakehurst, NJ:

Chance of more than 1":  38%

Chance of more than 3":  10%

Teterboro, NJ:

Chance of more than 1":  86%

Chance of more than 3":  48%

Morristown, NJ

Chance of more than 1":  86%

Chance of more than 3":  57%

Chance of more than 6":  10%

Somerville, NJ

Chance of more than 1":  81%

Chance of more than 3":  62%

Chance of more than 6":  10%

Sussex, NJ:

Chance of more than 1":  95%

Chance of more than 3":  86%

Chance of more than 6":  10%

Caldwell, NJ:

Chance of more than 1":  86%

Chance of more than 3":  62%

Chance of more than 6":  10%

Saturday Is Looking Snowier

Snowlovers know things had to go their way at least once this winter, and the trend is their friend with respect to Saturday's system.  Models have moved toward a colder solution and this of course would mean more snow.  Probabilities are now very high for receiving at least one inch of snow on Saturday in New York City.  Here are the numbers that I've been able to come up with thus far.

Probability in Central Park of receiving more than:

One Inch:  71%

Two Inches:  33%

Three Inches:  19%

In the meantime, a relatively weak system will be moving by tonight with a dusting of snow for many areas, especially north and west of the city.  I'll update as I get more information regarding the weekend system, including snow probabilites for different parts of the area!

Looking more wintry

In the midst of a nearly snowless winter, we now have two shots at accumulating snowfall over the next 96 hours.  In the meantime, get ready for a biting wind this afternoon as a much colder air mass enters the region.  We’ve already seen wind gusts over 40mph in some areas, and this will continue as temperatures tumble to near freezing by dusk!