Category Archives: Rain

NYC Weather Update – Labor Day Weekend

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Rejoice! The long awaited Labor Day Weekend is upon us. Although I’d love to say that the weather will be fantastic throughout, but unfortunately there will be a few disturbances traversing the region the second half of this weekend. Thunderstorms accompanying these disturbances may literally rain on the annual West Indian Day Parade in Brooklyn on Monday.

Friday – the remainder of today will be a picture perfect, fall-like day with high temperatures hovering right around 80. A pleasant, dry airmass is in place in association with an area of high pressure that’s currently sitting over us.

Saturday – essentially a repeat of Friday, but with a bit more cloud cover.

Sunday – high temperatures on Sunday will be considerably warmer than Saturday, since the area of high pressure sitting over us now will have moved to the east, building up southwesterly winds and allowing for an influx warm air to penetrate the region. Expect more humid and warm highs between the mid-upper 80s. A weak frontal boundary will be approaching Sunday, and transit the region late Sunday into Monday. This will be our first shot at rain and thunderstorms, some of which may deliver some heavy rain.

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Labor Day – the timing of the aforementioned frontal passage will be critical in terms of sensible weather Monday. It currently looks like Monday will be partly cloudy, with highs again in the mid-80s. There will be an increasing chance of scattered thunderstorms later in the day Monday leading into Tuesday as another weakening cold front nears the area.

Tuesday – the return to the work week will continue to feature warm and humid highs in the mid-upper 80s and a continued chance of thunderstorms as that cold front works its way through.

NYC Weather Update – Aug 25, 2014

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We have a fairly straightforward weather week ahead of us leading into the Labor Day Weekend. Currently, our region is sitting under an area of high pressure, which will be sliding to the southeast. As it does so, winds will shift to the south and southwest, allowing the entry of a warm and humid airmass that’s been responsible for brutal triple digit heat in the southern tier of the country.

Tuesday – temperatures will continue to climb into the mid-upper 80s under clear skies due to the aforementioned atmospheric dynamics.

Wednesday – this will be the warmest day of the week with temperatures approaching, if not topping 90, in some spots around the region. Some clouds will start to build in ahead of a cold front that is forecast to push through the area late Wednesday or Thursday. There is some discrepancy between different forecast models as to whether there will be a significant chance for precipitation with this frontal passage. Given this set up, it is likely even if there is rain, it won’t be widespread in coverage or long in duration.Screen Shot 2014-08-25 at 6.18.10 PMThursday – following the passage of the cold front, temperatures will fall back into the low-mid 80s for Thursday. Mostly sunny skies will return with high pressure moving in behind the cold front.

Friday – should be a similar day in most respects to Thursday, with slightly cooler highs around 80.

Labor Day Weekend – currently, Saturday looks like the best day of the long weekend, with high pressure still in control over the region. High temperatures should be around 80 again with mostly sunny skies. Unfortunately, it does appear that there will be an increasing chance of precipitation in the form of showers and thunderstorms Sunday afternoon and Monday. More on this later in the week.

NYC Weather Update – Aug 18, 2014

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This week will feature mostly calm and tame conditions for the most part, which is excellent news in comparison to last week when a record-breaking storm dropped 13″+ of rain on Islip.

Today-Wednesday will feature essentially the same weather, sunny to mostly clear skies with pleasant high temperatures in the upper 70s and low 80s.

Our first and only real chance at precipitation this week will be on Thursday, and it’s a low chance at that with the passing of a weak impulse of energy through the area. Screen Shot 2014-08-18 at 10.04.30 AM

Friday – high temperatures will continue to drop into the mid-70s as winds coming from the east will allow for a cooler marine air layer to park over the area.

NYC Weather Update – Jul 15, 2014

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A correction from yesterday – I had said today may see less potential for severe weather. In fact, the Storm Prediction Center once again has most of the NYC metro area under a slight risk for severe thunderstorms later today.

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Based on current satellite trends, it does appear there will be some breaks in the clouds this morning and afternoon. This will allow sufficient sunshine and daytime warming to fuel strong to severe storms across our region again later today. In the upper atmosphere, largely unidirectional winds from the south-southwest, a favorable jet stream set up, and approaching cold front suggest the potential for storms with damaging wind gusts and even some hail. Flash flooding is again a distinct possibility.

As you see below, portions of our area saw up to 1-1.5″ rain yesterday, and these same areas are in the target zone for severe storms today as well. With the upper level winds lining up from the south-southwest, training (where multiple storms hit the same location over a period of time) of storms is likely. This will enhance the risk for flash flooding.

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A note about the term unidirectional winds: Unlike a hurricane, severe thunderstorms thrive on upper atmospheric energy, and unidirectional winds at all levels are more conducive to imparting a rotation on a rising parcel of air (rotating thunderstorms can produce tornadoes).

Otherwise, expecting a warm, humid day, with highs in the mid 80s and some sun before storms arrive later in the afternoon. It will be cooler and more comfortable tomorrow with this stormy cold front having passed us!

NYC Weather Update – Jul 14, 2014

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The Storm Prediction Center has placed the entire NYC metro area in an area for a slight risk of severe weather today. A strong low pressure center over the Great Lakes and its associated cold front are slowly making their way towards the Eastern Seaboard. Despite the cloudiness today, forecasters are still fairly confident that atmospheric conditions will be favorable for the formation of severe thunderstorms in the region. Based on current radar trends, these storms would most likely not be arriving in the NYC area until later this afternoon. The primary threat to our area will be damaging winds and torrential rain capable of triggering flash floods.
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Tuesday will feature a similar set up for weather over the region, though there is less risk for severe weather tomorrow. However, strong storms are possible throughout the day and the risk of flash flooding is a distinct possibility. High temperatures will be in the mid 80s despite cloud cover, due to the influence of warm, humid air rushing in between the cold front and high pressure offshore over the Atlantic. This same warm, humid air mass is what will feed the storms for today and tomorrow. As you see below, the forecast rainfall total for today and tomorrow is as high as 3.6″ over Northeastern New Jersey, and ranges between 2.5-3″ for most parts of the Tri-State area.Untitled2

Wednesday – we get a reprieve from the stormy weather as the cold front and storm system finally move east of NYC. Expect a cloudy start to the day with gradual clearing and conditions improving markedly. The next weather story for Wednesday through the end of the week is the cool, polar air mass that will be a dominant feature. High pressure will build in behind this storm system and usher in much cooler temperatures, with highs in the low 80s Wednesday-Friday, and overnight lows in the low-mid 60s in the city, and in the 50s north and west!

Thursday & Friday – expecting these two days to be essentially the same weather-wise, with high temperatures in the low 80s in the city (and upper 70s further north). Sunny to mostly clear skies for both days.

NYC Weekend Weather – Return of the Polar Vortex? – Jul 11, 2014

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You may have heard from media reports that the dreaded polar vortex is set to make a return to the Eastern US during the middle of the coming week. I’ll discuss that in detail below. First, for the weekend forecast:

Today & Saturday – a very pleasant couple of days in the wake of the cold front that finally pushed through our area yesterday. You can feel a marked drop in humidity, and temperatures are much more comfortable. Saturday, high temperatures should top out in the mid 80s in NYC.

Sunday – a chance for afternoon thunderstorms and a high in the mid 80s, chance of rain increasing through out the day into the overnight hours.

Polar Vortex?

Forecast models are in good agreement that beginning Tuesday into most of the rest of next week, an upper air vortex (see below, the trough with an inclosed region surrounded by the blue arrows) will drop into the Midwest and Northeast from the northern regions of Canada. This vortex can be technically referred to as a polar vortex, a term that instantly revives media hype about how cold it will be. But keep in mind, during the summer, polar regions heat up as well, so even the coldest polar airmass and vortexes are much milder than their winter counterparts. Furthermore, the influence of the sun is quite strong as we just passed the summer solstice, so the sun is sitting at a very high angle each day and is highly effective at heating the air quickly. Hence, temperatures are expected to be much below normal for some areas, but we’re not talking about snow or ice.

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Upper air forecast from GFS for Monday, 8PM EDT, 500mb absolute vorticity.

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Next Week

There will be a good deal of energy traveling with the polar vortex, so we’re expecting a somewhat disturbed pattern of weather for the beginning of next week. Tuesday & Wednesday will see the best chances for rain and thunderstorms with a cold front approaching us from the west. Before the cold front, we’ll still see temperatures in the mid to upper 80s with a chance for thunderstorms Monday. Once the cold front passes, we’ll be right in the mix with the “polar” air mass, so our high temperatures will drop into the low 80s, and overnight lows will drop into the upper 60s for the latter part of the week.
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NYC Weather Update – Jul 8, 2014

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We had a nice couple days of seasonable, dry, and sunny weather this past weekend in the wake of Hurricane Arthur’s passage, but that came to an end yesterday and today. The high pressure that gave us the nice conditions moved to the southeast and out over the open waters of the Atlantic, merging with the semi-stationary Bermuda high. As you may know, this set up favors hot, humid temperatures all along the east coast, and we are no exception. Expect high temperatures to top out in the low-mid 90s today, with uncomfortably high humidity.

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Wednesday – we may get some relief from the heat later today and overnight with a pre-frontal trough and scattered diurnal thunderstorms forming in the hot, unstable air. However, tomorrow will be more or less a repeat of today, with temperatures in the upper 80s to low 90s and muggy conditions.

Thursday – The cold front above won’t actually reach us until late in the day Wednesday, but when it does hit us Thursday, it will bring some chance for scattered thunderstorms and a slight drop in temperatures back down into the mid 80s.

Friday – amazingly, our streak of great weekend weather (with the exception of Arthur) is set to continue. Once the cold front clears us Thursday, we’ll see high pressure build in from the west Friday, which means some cooler winds and lower humidity airmass from Canada moving in. Temperatures should be milder, in the low-mid 80s Friday through the weekend.

Our next shot at precipitation will be late Sunday into the beginning of next week.

Hurricane Arthur Update – Jul 3, 2014

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Hurricane Arthur has held steady with 90mph winds over the last 6 hours or so. The storm’s eye continues to grow more defined, with central pressure continuing to fall to 977mb. These signs point to further strengthening, and the National Hurricane Center is still forecasting Arthur to hit Category 2 strength as it makes its closest pass over North Carolina.

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Track Forecast

Over the course of the day, Arthur has moved further north than originally forecast, and is only slowly beginning to make its turn towards the northeast. As a result, most forecast models have been pushed a bit further to the west. Most of the models now have Arthur making landfall somewhere over coastal North Carolina, and then passing inside the 40N, 70W benchmark offshore of the Northeast. The bottom line is that the updated forecast track increases the likelihood of adverse impacts to coastal areas all along the East Coast. This includes high surf, beach erosion, and dangerous riptides even in areas that don’t see direct impacts. This new track also puts portions of Southeastern New England under risk of experiencing tropical storm conditions, and heavy rain bands from Arthur as it passes offshore.

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It’s a good thing that mandatory evacuations were placed for the Outer Banks and coastal North Carolina, as portions of these low-lying areas are forecast to experience storm surge inundation of greater than 3 feet during the peak of the storm.

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Blue shaded areas = 1-3′ of storm surge Yellow areas = between 3-6′ of storm surge

NYC Weather – Independence Day – Jun 30, 2014

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Lots to talk about on the last day of June, which brings with it the opening of a warm trend and possible mini heat wave. A stubborn low pressure system over the Plains States is pushing warm and humid air from the Gulf ahead of a leading cold front. As a result, Tuesday will feature warm, muggy conditions with highs in the upper 80s, maybe even touching 90.

Wednesday, that frontal boundary comes closer, and with the heat and humidity in place, we’ll have the right conditions for some pop-up showers and thunderstorms later in the day. However, coverage is expected to be widely scattered. Highs again will be in the upper 80s, possibly hitting 90.

Thursday -as the cold front makes its approach in earnest, a pre-frontal trough is forecast to develop, and this should help spark off more widespread showers and thunderstorms than on Wednesday. Expect high temperatures to be somewhat lower due to cloudy skies, but still warm and humid in the mid to upper 80s.

Friday (Independence Day) – A lot of weather forecasters were saying earlier this weekend that July 4th was going to be a nice day with no rain. Sadly, that doesn’t appear to be the case now, as the timing of that pesky cold front has slowed down somewhat. This does mean you could see rain and or thunderstorms during the day Friday and into Friday night, but at least the heat will break somewhat with temperatures only around 80.

Cold front right on top of us Friday could rain on your July 4th plans.
Cold front right on top of us Friday could rain on your July 4th plans.

First Named Tropical System of the Atlantic Hurricane Season?

Over the weekend, a disturbance off the east coast of Florida began to show signs of increasing organization, to the point that the National Hurricane Center now gives the system an 80% chance of forming into a tropical depression in the next 2 days. If it does, then it will become the first named tropical system of the 2014 Atlantic Hurricane Season.

High resolution satellite image of the incipient tropical system off the east coast of Florida
High resolution satellite image of the incipient tropical system off the east coast of Florida

Why does this matter to us? Well, as it currently stands, it appears this tropical system/possible storm may impact our weekend weather here in the Northeast. Some forecast models have this storm moving to the near offshore waters of the Northeast by Saturday (indicated in pink circle below). This could bring the potential for rain to parts of the Northeast, in particular, New England. Fortunately, it doesn’t appear as though this storm will strengthen much (below you see the lowest pressure at the center of 1012mb, for reference, normal pressure at sea level is 1013mb), and in fact, it will likely make a transition to becoming an extratropical cyclone/storm rather quickly after it moves north of Florida. Still, it’s a bit too early to tell just where this storm will go, so it bears monitoring.

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Possible storm tracks as illustrated by GFS ensemble members
Possible storm tracks as illustrated by several different forecast models

NYC Weather Update – Jun 19, 2014

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We’re going to get some welcome relief to the brief warm spell we’ve had so far this week, as a large area of showers over Pennsylvania will move east slowly during the course of the day today. You can already feel a change in the air, with temperatures generally 10 degrees (or more) cooler this morning than at this time yesterday.

Friday – the cold front responsible for bringing us showers today will move through to our south and usher in a cool, dry air mass from Canada in its wake. High pressure will then build over Quebec and dominate the area through at least Monday. Temperatures will be pleasant near 80 with mostly sunny skies.

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Saturday and Sunday – the pattern of pleasant, mild and seasonable temperatures will set the stage for the formal beginning of summer (Saturday, June 21st is the day of the summer solstice, the longest day of the year). Temperatures both days will range in the upper 70s to low 80s, with low humidity and sunny skies.

Monday and Tuesday – this stretch of nice weather continues into the beginning of the next work week, with high pressure slowly moving off to the east, but still warm and nice. Temperatures again will be in the low 80s with mostly sunny skies.

Our next chance at rain will come Wednesday with a cold front associated with a two storms systems that will merge (one over the Mississippi Valley, the other moving from Ontario).

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