Tag Archives: high pressure

NYC Weekend Weather (Brooklyn Half Marathon) – May 14, 2015

This week ends off with pleasant, sunny, dry weather, and temperatures slightly above average in the low 70s. We get a chance at some much needed rain (there were actually brush fires yesterday, giving you an idea how dry it’s been), but the unfortunate part is that the rain will likely occur in periods on Saturday. Sunday will be better, as it doesn’t look like the rain sticks around that long.

Rest of today – a gorgeous spring day with high pressure in control, yielding a cloud-free and seasonable day with highs in the low 70s.

High pressure firmly entrenched over us today and tomorrow.
High pressure firmly entrenched over the region today and tomorrow.

Friday – expecting more of the same during the day, mostly sunny and mild with temperatures topping out again in the low 70s. Later Friday night, there could be a few showers and thunderstorms that develop as an approaching frontal system nears the area.

Saturday – lingering showers and maybe a thunderstorm or two in the morning, but it does not appear the entire day will be a washout. We’ll be in the warm sector which should allow for temperatures to approach 80 or slightly higher, depending on the cloud cover situation in the afternoon hours. Sadly, I know this is not what all you runners that are going to be doing the Brooklyn Half Marathon want to hear.

North American Model high resolution output for Saturday at 11AM, showing the possibility of showers.
North American Model high resolution output for Saturday at 11AM, showing the possibility of showers.

Sunday – at this point, it appears Sunday will be dry, with more clouds than sun, and temperatures remaining warm in the upper-70s. A blocking high pressure center over the Gulf of Maine should be enough to prevent rain from entering the area. gfs_namer_108_1000_850_thick

Monday – the high pressure depicted above will retreat eastward a bit, which would allow for a better chance of rain later Monday evening/night into Tuesday. During the day, conditions should be dry with partly sunny skies and a high near 70.

NYC Weekend Weather – May 8, 2015

Another splendid weekend is in store for us with warm temperatures in the upper-70s and near 80. Subtropical Storm Ana marks the first named storm of the 2015 Atlantic Hurricane Season. It is not expected to bring us any direct impacts, however, it could bring moisture our way that could supplement a storm system forecast to pass through early next week.

Rest of today – early fog has burned off, skies have cleared, and temperatures should top out near 80. We have been under the persistent influence of a high pressure center that has been responsible for pumping in this warm, moist air from the south.

Saturday – clouds and sun, with sunny breaks more likely to appear near the coast in the afternoon. High temperatures should be a bit cooler in the mid-70s with the influence of clouds, however, any sunny breaks could easily shoot temperatures up a few degrees.

Sunday – once again, Sunday comes through as the best day of the weekend, with mostly sunny skies and highs in the low-80s.USA_East

Monday – clouds for the most part as a frontal boundary approaches from our north and west. High temperatures will still be quite mild with the influence of high pressure bringing southerly winds, expecting a high again near 80. Some chance for afternoon thunderstorms to develop as that frontal boundary nears.

Tuesday – probably our best shot at getting measurable rainfall as the aforementioned front passes through. Some left over moisture from Ana could work its way into this setup. Ahead of the front, temperatures should still rise into the upper-70s. It’ll be noticeably cooler for the second half of the week.

 

Subtropical Storm Ana

We have our first named storm of the 2015 Atlantic Hurricane Season which doesn’t officially begin until June 1st. Subtropical Storm Ana developed out of a weak tropical disturbance off of Florida. This just goes to show, a tropical cyclone can form under the right conditions at any time of the year.

Visible satellite loop of Subtropical Storm Ana this morning - Geostationary Satellite Server
Visible satellite loop of Subtropical Storm Ana this morning – Geostationary Satellite Server

Subtropical Storm Ana fortunately does not have much time to organize and intensify before it makes landfall on the coast of the Carolinas. This should limit any serious damage, however, these areas will likely experience prolonged high winds, torrential rain, and coastal flooding.

Global Forecast System ensemble forecast tracks for Ana
Global Forecast System ensemble forecast tracks for Ana

NYC Weekend Weather – Apr 30, 2015

This week ends with clouds and some small chance of rain, but we’re in for a real sweet stretch of pleasant conditions and warmer than average temperatures from Sunday into early next week. In fact, we could be hitting 80 by Tuesday ahead of a cold front that could bring some thunderstorms with it, before we cool back down into the low-70s, which is still above normal.

Friday – due to the influence of a weak area of low pressure to our south, we will be seeing generally cloudy skies, with some very slight chance for scattered showers in the southernmost portions of the region. Temperatures will be moderate by northeast winds circulating counterclockwise around the low pressure to our south, yielding high temperatures in the upper 50s to near 60, just a few degrees below normal.

Saturday – as the aforementioned low pressure system slides off to the east over the Atlantic, clouds should gradually decrease. Temperatures will also rebound somewhat to around normal with a high in the mid-60s. However, there could be just enough instability in the atmosphere to spark a couple scattered showers or thunderstorms.

 

gfs_namer_081_1000_850_thickSunday – by this time, an area of high pressure will have developed over the Carolinas. This setup will favor the influx of a warm airmass from the Gulf of Mexico. Skies will clear, and temperatures will be noticeably warmer in the low 70s.

Monday – another gorgeous day to start the week, with sunny skies and high temperatures in the mid-70s (10º above normal). Don’t say I told you so, but if there were a day to skip work, this would be it.

Climate Prediction Center's 6-10 forecast for temperature. Our odds are very good for getting warmer than normal temperatures.
Climate Prediction Center’s 6-10 forecast for temperature. Our odds are very good for getting warmer than normal temperatures.

Tuesday – although it will be even warmer Tuesday than it will be Monday, with highs possibly topping 80, it won’t be quite as pleasant since clouds will be building up ahead of a cold front that will bring our next chance at rain.

NYC Weekend Weather – Apr 2, 2015

We’re finally getting a run at some spring-like weather with highs above normal to end the work week. We’ll get some of those April showers that we’re hoping will lead to a fantastic display of spring flowers later this month and May. A cold front passing through Saturday will knock temperatures back a notch, and then we enter into a period of active weather dictated by a stalled frontal boundary the first half of next week.

Today – warm and breezy, with a high near or just over 60. Clouds increasing late, as a warm front approaches from the south. A chance of showers develops overnight as this warm front continues moving towards us.

 

Friday – an even warmer day on tap, with that aforementioned warm front having passed through. We’ll be in the warm sector until later when a cold front moves through. High temperatures, despite rain and clouds, should still be able to top out in the lower 60s.

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Saturday – with the cold front passing through, temperatures will drop on Saturday, back to about normal in the lower 50s. Partly sunny skies will slowly give way to more clear conditions.

Sunday – Sunday through Wednesday will be rather interesting. A frontal boundary is expected to push through Sunday, however, it is then expected to stall in our vicinity for a few days. As waves of low pressure ride along this stalled frontal boundary, the chance for showers persists through Wednesday.

A nice start to next week with above average high temperatures Monday and Tuesday in the mid-upper 50s along with those chances for rain.

NYC Weekend Weather – Mar 27, 2015

We got a taste of what high temperatures should be like for this time of year Wednesday and Thursday, but the cold front that has since moved through will set the stage for a return to below normal temperatures to start the weekend. With a low pressure center well to our east possibly spawning an inverted trough, there is some possibility for light rain/snow mix overnight Friday and into Saturday. Temperatures rebound Sunday and we go into next week with about normal temperatures right around 50.

Rest of today – a noticeably colder night on tap with northwesterly winds in the wake of that aforementioned cold front allowing for low temperatures to dip to about freezing. Any lingering precipitation would manifest itself as rain/snow mix, with points further east having a higher chance of seeing wet snow.

Saturday – a much colder than average day, with high temperatures only hitting the mid-upper 30s, nearly 15 degrees below normal. Cloudy, windy, and raw, with snow showers possible early (accumulation unlikely), and rain showers later.

We are right on the western fringe of a precipitation associated with that low pressure center off  of southern Nova Scotia.
We are right on the western fringe of a precipitation associated with that low pressure center off of southern Nova Scotia.

Sunday – things clear up nicely as that low pressure keeps pulling off to the east. Temperatures rebound a bit into the low 40s, which is still well below average.

Monday – a continued warmup ahead of a dry cold front, with high temperatures topping out around 50 under increasingly cloudy skies.

Tuesday – a pleasant, seasonable day with high temperatures in the low 50s and mostly sunny skies as high pressure comes into control.

The next chance at precipitation comes Tuesday night into Wednesday with a fast moving clipper system.

Warmer air swinging around a high pressure area to our south.
Warmer air swinging around a high pressure area to our south.

NYC Weather Update – Mar 5, 2015

Today may be the last major winter storm of the winter for us. It certainly has been an eventful and cold winter for the books. We’ll end the week and start off this weekend and early next week with below normal temperatures, but temperatures will rise steadily throughout next week, such that we should be back to normal temperatures in the mid-upper 40s by the end of next week.

Rest of today – snow is already tapering off over the area, with widespread snowfall totals of between 4-8″ reported (largely in line with forecasts). Any remaining precipitation should completely clear the area within the next couple of hours. Screen Shot 2015-03-05 at 4.58.33 PM

Friday – we endure what we all hope will be the last day of temperatures in the low-mid 20s as cold, dry air filters in behind this storm system.

Saturday – high pressure moves in over the weekend, with temperatures Saturday edging up to around freezing.

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Sunday – fair weather continues, but perhaps with more clouds on Sunday as some weak impulses of energy move over areas well to the north of NYC. High temperatures will increase to the low 40s.

Monday – the warming trend continues as spring approaches, high temperatures continue to warm into the mid-40s under partly cloudy skies.

Finally leaving the Arctic air behind?

A large scale warming trend is forecast to take hold over much of the US during the medium term. Temperatures next week should warm progressively such that by next Friday, we’ll be looking at (gasp) high temperatures near 50. The week after, on the cusp of spring, almost the entirety of the Continental US is forecast to experience warmer than normal temperatures, with the exception of Texas, and New York into Southern New England. However, we are forecast to be in normal range of temperatures for this time of year, which means mid-upper 40s. Not quite flip flops and t-shirt weather, but a positive trend nonetheless.

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NYC Weekend Weather – Feb 26, 2015

Another cold weekend is on tap for the area, before the start of a week of active weather. It does appear that March will be coming in like a lion this year.

Rest of today – some sun, with a chance for light flurries and a high in the mid-20s.

Friday – diminishing clouds with a high temperature again in the mid-20s. High pressure begins building to our west, yielding northwesterly winds that will allow chilly, Arctic air to filter back into the area. Overnight lows Friday will be in the low teens.

Saturday – with high pressure to our west still firmly in control, it will be a sunny, but cold day, with highs again only in the mid-20s.

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Sunday – clouds will be increasing ahead of an approaching storm system and as high pressure exits to the east. There will be a slight warmup ahead of the storm, with temperatures topping out near freezing. Snow likely overnight, although significant accumulations are not expected.

Monday – temperatures will warm potentially into the low 40s on Monday as warm air from the southwest gets pulled into the storm system. There may be some mixed precipitation along the coastal plain, with all snow elsewhere, mostly early in the day.9khwbg_conusTuesday – following the passage of the storm on Monday, temperatures dip back to around freezing, ahead of another storm system that will be impacting the area Tuesday into Wednesday. This storm has a greater potential significant precipitation.

NYC Weather Update – Feb 16, 2015

Sunday night’s lows were the coldest of the year thus far, indicative of the coldest airmass to hit the area in recent memory. Again, according to climatology, the last time New York City itself hit a low of zero was in January 1994. Unfortunately, the cold snap does not show any signs of abating during the week, although the first half of the week will see daytime high temperatures in the mid-upper 20s as opposed to the teens. We’ll finish the week off back into the teens before a warmup to above freezing with an approaching storm system this weekend. Behind that – you guessed it, another round of arctic air and abnormally cold temperatures.

Rest of today – cold and overcast, with high temperatures not even getting to 20 in the city. Snow should begin falling overnight, with generally light accumulations by daybreak.

Tuesday – slightly warmer with high temperatures in the mid 20s, but also with a chance for snow as a storm system now dumping snow across a vast swath of the South passes well to the south of us. We could still end up picking up 2-5″ of snow in the city, with higher amounts along the south facing shores of Long Island and minimal accumulation north of I-84.

Snowfall total forecast for Tuesday
Snowfall total forecast for Tuesday

Wednesday – a weak cold front will pass through Wednesday, and may give us a small chance for light snow, otherwise, expecting cloudy skies with high temperatures in the mid-upper 20s.

Thursday – behind that cold front, we get our next shot of Arctic air, with overnight lows into Thursday struggling to hit 10 in the city, and zero and below in outlying inland areas. Daytime highs will only be in the mid-teens despite ample sun. Thursday night, we might get another shot at low temperatures hitting zero in the city, with lows below zero across most inland locations.

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Friday – basically a repeat of Thursday, sunny but with brutally cold temperatures in the mid-teens.

Over the weekend – watching for the development of a storm system that could bring some wintry mix/freezing rain to the area, but finally give us a break from below freezing temperatures.

More Cold on Tap to End February

After the weekend storm, we get yet another reinforcing blast of Arctic air to end the month of February. Below, you’ll see the Climate Prediction Center‘s 8-14 day outlook spanning February 23 – March 1. We’re in a region with a greater than 60% probability of experiencing below average temperatures for this period.

Climate Prediction Center 8-14 day outlook for Feb 23 - Mar 1
Climate Prediction Center 8-14 day outlook for Feb 23 – Mar 1

NYC Weekend Weather – Nor’easter Update – Jan 23, 2015

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.
Storm track forecast from the Weather Prediction Center, with clusters indicating forecast positions of individual ensemble members.

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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 2″ of snowfall
Probability of greater than 4" 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"
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.

NYC Weekend Weather – Jan 15, 2014

We end this week off with a windy day Friday, followed by an intrusion of cold air on Saturday before a warmup Sunday that should be accompanied by some rain during the day, then possibly a mix of rain and snow Sunday night. Some chance of snow persists into early Monday.

Friday – a cold front dropping from Canada will tighten the pressure gradient ahead of it, bringing with it breezy west-northwest winds between 15-25mph during the day tomorrow. High temperatures will be about normal in the upper 30s, but with wind chill values only in the 20s.

Saturday – subsequent to the passage of that cold front, we get another shot of cold, arctic air, with temperatures on Saturday struggling to even reach 30 in the city, and only in the 20s elsewhere.

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Sunday – a low pressure system will be moving steadily northeast into Quebec by Sunday. This storm system will have a trailing cold front as well as a preceding warm front. We should enter the warm sector behind the warm front passing over us Sunday. This will allow for temperatures to rise into the mid-40s (possibly higher in a few spots). There will be a transfer of energy to a secondary low pressure center which is forecast to form off the Mid-Atlantic coast. This will result in the chance for us to get a few periods of moderate-heavy rain on Sunday, especially in the afternoon hours. As the coastal low moves off to the northeast, rain should taper down during the overnight hours into Monday, and temperatures will be cold enough to support a chance of rain/snow mix.gfs_namer_087_1000_850_thick

Monday – snow showers should end early Monday. High temperatures will be about average for this time of year, in the upper 30s.