We have an active weather pattern with two storms moving through NYC this first full week of spring. A nor’easter will pass offshore today, bringing mixed precipitation early then cold rain later. We get a lull Tuesday with temperatures rebounding into the mid-50s, before a second low hits Wednesday. This will bring another round of cold rain with temps back in the mid-40s. Temperatures rebound again Thursday after this second storm.
Rest of today – some light mixed precipitation has already moved through the region this morning. A second round of more consistent, moderate precipitation should hit around lunch. High temperatures only in the mid-40s. Overnight lows around 40°F.
High resolution rapid refresh simulated radar for 1PM Monday
Weather Prediction Center surface forecast for 8PM Monday
Tuesday – the nor’easter pulls away to the northeast and we get a brief period of calm with weak high pressure building in. Partly sunny skies expected with highs in the upper-50s. Overnight lows in the low-40s with rain chances picking up towards Wednesday morning.
Wednesday – a second storm system moves up from the south. This will bring us another round of cold rain, with highs back in the mid-40s. Overnight lows around 40°F.
GFS model 500 mb height and relative vorticity valid 2PM Wednesday. A shortwave trough is evident over the Northeast, providing upper-level divergence for the second storm to hit this week.
Thursday– similar to Tuesday with things drying out. Partly sunny skies with high temperatures in the mid-50s. Overnight lows in the mid-40s.
Cloudy day with light rain possible to start the forecast period. Skies clear for the remainder of the week behind this storm as high pressure builds. Temperatures will dip into the 30s for a brief stretch as well before rebounding back to above normal levels in the mid to upper-40s. Looking ahead into next week, above normal temperature trend is very likely to continue.
Rest of today – Light rain possible today with a warm front passing nearby and a cold front following behind that. However, the bulk of the moisture with this storm system appears to be focused south of the region, so not expecting any heavy rainfall totals. Otherwise, mostly cloudy with highs in the upper-40s. Overnight lows around 40°F with gradual clearing towards daybreak.
Weather Prediction Center surface forecast for 7PM Tuesday.
Wednesday – mostly sunny with high temperatures in the low-40s, about average for this time of year. Winds turn to the northwest behind the cold front, which will facilitate cold air advection. Overnight lows in the mid-20s as a result with high pressure building.
Thursday – cold start to the day will likewise mean a cooler high temperature in the mid-30s with mostly sunny skies. High pressure continues to exert its influence. Overnight lows once again quite cold in the low-20s.
Climate Prediction Center temperature outlook for Feb 23-27, showing greater than 90% probability of above normal temperatures for much of the Northeast.
Friday– this pattern continues with high temperatures Friday reaching into the mid-30s under mostly sunny skies. Overnight Friday into Saturday, the high pressure finally starts moving east in earnest. Lows will range in the upper-20s.
Light rain today will fall today. This will be followed by a brief spell of sunny skies and calm weather Wednesday. Another storm system impacts the area Thursday, bringing some mixed precipitation and rain. On the back side of this system, a drastic drop in temperatures will take place going into the weekend. This will be the coldest air mass we’ve seen in many weeks with lows in the teens.
Rest of today – Light rain in the morning and cloudy. High temperatures in the upper-40s. Overnight lows in the mid-30s with gradual clearing.
Weather Prediction Center surface forecast for 7AM Wednesday
Wednesday – high pressure briefly builds in with high temperatures in the mid-40s. Mixed precipitation could begin later in the day as the next storm system approaches. Overnight lows in the upper-30s with increasing mixed precipitation then transitions to rain.
Thursday – A warm up takes place with a warm front and southerly flow overnight. High temperatures reach into the mid-50s with rain ending in the morning/early afternoon. Much cooler temperatures overnight with lows around 30°F once the cold front of this storm system moves through.
GFS model 1000-500 mb precipitation and thickness valid 5PM Friday. Note the large area of Canadian high pressure centered over Indiana.
Friday– strong Canadian high pressure builds behind the cold front mentioned above. A much colder air mass will accompany this high, with temperatures Friday only in the low-30s. The real chill takes place overnight, with lows dropping into the mid-teens as Arctic air keeps pumping in!
The track of the imminent nor’easter and blizzard has continue to trend west of earlier model runs. This has introduced increasing uncertainty as to overall snowfall totals along the immediate coastal areas along with possible wintry mix/freezing rain. On the other hand, confidence is increasing in heavy snow for areas north and west of the city, with snowfall totals 18″+ looking likely.
Impacts – heavy snow north and west of the city, snowfall accumulations in the interior 16-20″+ looking likely. Sharp gradient in the heaviest snowfall totals approaching the coast where wintry mix, freezing rain, and even plain rain could mix in during the early afternoon Tuesday. The exact location of the extent of warm air intrusion off the ocean will ultimately determine the difference between routine totals over 1 foot and areas that receive much lower snowfall totals. The difference in some cases could be a matter of mere miles. This line could fall in and around NYC itself. Still expecting a period of blizzard or near blizzard conditions for NYC during the course of this storm even if a transition to mixed precipitation does occur. Snowfall totals could still pile up close to a foot or over prior to this transition. The possibility of freezing rain and ice introduces an additional hazard on the roads and when coupled with strong winds of 30-35mph and gusts 45mph+ could result in power outages.
Timing – light snow should begin to fall early into the overnight hours, progressively growing in intensity. In the city, overnight accumulations of 3-6″ possible, with a sharp increase in totals north and west. Heavy snow with sleet and wintry mix during the morning and early afternoon in the city, all snow in points north and west. Blowing and drifting snow with blizzard conditions possible. Snow begins to wind down during the evening hours.
Caveats – any further movement of the storm track west would result in drastically lower snowfall totals for NYC and points east along the coast. Correspondingly, an eastward shift of the storm track would put NYC itself squarely in the bullseye for the heaviest snows.
We’ve finally had a stretch of warmer than average weather after what seemed like an endless winter. Things are set to get even warmer tomorrow in the wake of tonight’s rain storm, before cooling off back into normal range to end the week. Another round of rain (with some mixed precipitation inland) will be impacting the area Friday into Saturday.
Rest of today – light rain falling now should increase in intensity over the course of the evening. Steady rain is expected overnight. Dense fog and low visibilities may be a problem overnight into the early morning hours, due to the influence of a saturated, warm airmass approaching an area of colder air. Overnight lows in the low 40s, with dew points around the same (fog often forms when dew point = air temperature).
Wednesday – any remaining rain should end quickly tomorrow morning. Clouds will give way to sun as high pressure begins to take hold over the area. Before too cold air gets into the area due to a northwest wind, we should see temperatures reach the mid-50s (wouldn’t be surprised if some spots hit close to 60 with the increasing daylight hours).
Thursday – another pleasant, and seasonable day, with plenty of sun and high temperatures around normal in the mid-upper 40s.
High pressure in control
Friday – one more day of decent weather, but with slightly more clouds than Thursday. Temperatures should top out around the mid-40s again. The next storm system approaches from the west and rain should begin to fall during the late evening hours. Overnight, some mixing with snow/wintry mix could occur, however, by daybreak Saturday, temperatures will be well above freezing and any mixing should return to all rain.
Saturday – a rainy day, but on the mild side with temperatures near 50.
Next storm coming Friday into Saturday
A cooldown coming
Unfortunately, after a week of normal temperatures, we are likely to see a return to below normal temperatures for the second half of March, based on the following forecasts from the Climate Prediction Center. High pressure will be dropping down from Canada again next week, leading to this greater than 60% probability of below normal temperatures. Luckily, since normal temperatures are now in the upper 40s, the below normal temperatures will not mean a return to the frigid tundra.
Climate Prediction Center 8-14 day temperature outlook
Climate Prediction Center 1 month temperature outlook for March
The details are starting to come together for tomorrow’s Nor’easter. Over the past day, forecast models have been pointing to a faster moving system, such that the onset of precipitation is expected to begin overnight tonight, with the bulk of the precipitation ending by early afternoon tomorrow. This storm is expected to throw a little bit of everything our way tomorrow, making for a nasty day overall, with snow changing over to freezing rain or sleet, then perhaps a period of plain rain, followed by a possibility of a rain snow mix.
What to Expect
Snow, moderate to heavy at times, beginning overnight tonight. Winds picking up from southeast, then eventually moving to the northeast and north during the day Saturday. Snow transitioning to a period of possibly freezing rain or sleet during the morning hours, then a period of rain around midday and a possible rain/snow mix towards late afternoon before precipitation gradually tapers off later in the evening. High temperature right around or slightly above freezing.
Forecast Storm Track
Forecast models are in generally good agreement that the center of this Nor’easter will be passing just inside the 40ºN 70ºW benchmark sometime in the late afternoon Saturday (approx 4-5PM).
Without a high pressure center to the north supplying cold air to the area, this setup will allow for enough warm, moist air to circulate around the eastern side of the low pressure center to give us a mix of precipitation throughout the day. The extent to which snow can be sustained will be strongly dependent on dynamical cooling, and how quickly cold air can be pulled in on the western side of the low pressure center.
Storm track forecast from the Weather Prediction Center, with clusters indicating forecast positions of individual ensemble members.
Snowfall Forecast
As you can see below, the probability of more than 4″ of snow is quite low for coastal areas, especially Eastern Long Island, where mainly rain is forecast. The heaviest totals (no more than 5″, most likely) will be concentrated well north and east of NYC where temperatures are expected to be cold enough to sustain all snow for longer. Because the forward speed of the storm is now predicted to be faster, the chances of NYC getting any significant snowfall (even 2″) is considerably lower. Most of the city is in a swath of between 30-40% chance of getting more than 2″ of snow.
Probability of greater than 2″ of snowfall
Probability of greater than 4″ of snowfall
Ice Accumulation
The probability of us receiving a trace, but a measurable amount of ice from freezing rain is quite a bit higher than the probability of receiving snow, with most of the city in the 40-60% range.
Probability of ice accumulation greater than .01″
Sunday – the storm will be long gone by Sunday, and we’re expecting to hit highs in the mid-upper 30s.
Monday – there is some potential for a round of all snow on Monday, but forecast models have not been in good consensus on how this will play out. A clipper system is expected to pass through, though it is unclear whether this system will spawn a secondary low offshore. In the latter case, we could see some significant snow, while if it’s just a clipper, we probably won’t see more than a couple inches.
