Tag Archives: tropical weather

NYC Weekend Weather + Note on Harvey – Aug 25, 2017

I’ve returned from Europe (missed the eclipse though!) to a very pleasant stretch of calm weather and slightly below normal temperatures. Surface high pressure to our northwest over Ontario will continue to bring us cool, dry Canadian air that evokes a more fall-like feel.

Rest of today – just about normal temperatures with highs around 80°F, skies have cleared up nicely and we should have spectacular weather for the start of the weekend.

Saturday – high pressure remains in control, and gives us another pristine day of slightly below normal temperatures in the upper-70s but lots of sun.

Sunday – basically a clone of Saturday, high temperatures in the upper-70s, lots of sun.

Monday – more of the same with temperatures again in the upper-70s, maybe a few more clouds, but who can complain especially when you consider the next section.

 

Hurricane Harvey a Major Threat to the Texas Coast

It’s worth mentioning here that we have a very dangerous situation developing on the Texas coast today and over the course of the next few days with Hurricane Harvey. If you have friends or family in this area, it’s not a bad idea just to try and check in with them.

GOES 16 visible satellite image of Harvey showing impressive size, distinctive eye, decent symmetrical outflow except on the side already beginning to interact with land.

Harvey originally formed over the eastern Caribbean, dissipated approaching the Yucatan, and then redeveloped as it emerged over the Bay of Campeche. Favorable conditions have allowed Harvey to strengthen quickly into a Category 2 storm, and it’s forecast to continue strengthening to Category 3 before landfall.

This would make it the first major hurricane to make landfall on the US mainland in nearly 12 years. The biggest concern with Harvey is that most forecast models have the storm stalling out after landfall, and possibly looping back out to the Gulf and making a second landfall mid-week next week in eastern Texas, still retaining tropical storm strength. Two areas of upper-level high pressure will essentially be trapping Harvey in place.

The slowing forward motion of the storm means that tropical storm and hurricane force winds will rage for many hours. The longer the winds churn up the waters of the gulf, the bigger the life-threatening storm surge along the coast. Peak storm surge of 6-12′ is forecast. That’s without waves on top. For reference, Sandy brought a peak storm surge of 14′ to The Battery. That’s well above the first, and well into the second story of most homes. On top of that, rainfall totals measuring 2-3′ are possible, which would cause widespread inland flooding.

NYC Weekend Weather – Aug 4, 2017

A hot week transitions into a weekend that will see the end of the heat and humidity for at least half of next week and maybe longer. Rain and thunderstorms dot the forecast except appropriately Sunday.

Rest of today – partly sunny with high temperatures in the mid-80s. The rain and thunderstorms this morning give way to a dry day otherwise.

Saturday – a warm front moves through overnight into the morning with a cold front following right on its heels. This will bring a period thunderstorms producing heavy rain at times. Marginally favorable atmospheric conditions could spawn a few strong storms. Clouds clear up in the afternoon and highs are expected to reach normal levels in the mid-80s.

Sunday – cooler, drier air moves in behind the cold front Saturday. High pressure builds to the south and west and moves south sending cooler Canadian air around its periphery towards us. High temperatures will be comfortable around 80°F with lots of sun.

Monday – a weak disturbance brings rain and cooler temperatures, well below average only in the mid-upper 70s.

Trouble in the Tropics?

A vigorous tropical wave has spun up off the west African coast and Cabo Verde. Storms originating from this region have historically been some of the most powerful and damaging, but that’s if they can sustain the transit across the Atlantic. The National Hurricane Center has this wave at a 50% of forming into a tropical depression or storm in 2 days, and 80% chance in 5 days. It’s worrying that it’s starting to get picked up on long-term GFS model runs taking a swipe at the US East Coast as a strong tropical cyclone, however, this far out, it’s difficult to say which one of many scenarios could play out. It does bear monitoring though.

GFS for Wednesday 8/16, with the tropical system in the picture right off the East Coast of the US.

NYC Weather Update – Jun 19, 2017

The weather on Sunday turned out to be a real gift for fathers in the region, yielding a lot more clear skies than anticipated going into the weekend. We could have a rough start this week with possible severe weather, and another chance of rain mid-week. A tropical system forming over the Gulf of Mexico bears watching this coming weekend.

Rest of today – humid and warm with high temperatures in the low to mid-80s. Mostly sunny to start. All the ingredients for possibly severe thunderstorms will be in place this afternoon and evening. A flash flood watch is in effect for most of the area west of Long Island. The Storm Prediction Center has placed some of the region west of the Hudson River under an enhanced risk of experiencing severe weather with the city itself in a slight risk area.

A vigorous cold front will move east towards NYC today. As we can feel, the airmass ahead of the front is saturated and warm. The more sun we get before the front approaches, the greater the destabilization in the atmosphere. The cold front will line up with the flow of the jet stream, which will favor line segments and training of storm cells repeatedly hitting the same areas (flash flood warning is in place because of this).

Timing of the leading edge of the storms appears to be around 5pm. Any storms or substantial cloud cover ahead of this would decrease the severe potential. Primary threat along this leading line of storms would be damaging wind gusts with a small chance for hail and a couple isolated tornadoes.

Behind this leading line of storms, we could see a slight break around 8PM, but then more rounds of moderate to heavy rains that could lead to flash flooding.

Tuesday – severe weather and rain should dissipate fairly quickly after midnight. Decreasing clouds in the wake of the cold front though high temperatures remain similar to today due to the influence of southwest winds.

Wednesday – mostly sunny with high temperatures in the low-80s. A chance for rain in the afternoon, but much milder and less widespread than today.

Thursday – mostly sunny again, with highs in the low-80s again.

 

Potential Tropical Storm in the Gulf

Two possible tropical systems are churning, one east of the Windward Islands and the other crossing over the Yucatan into the Gulf of Mexico. The latter system may have a tangible impact in terms of bringing tropical moisture to the area this coming weekend.

 

 

 

 

 

 

NYC Weekend Weather – Apr 21, 2017

A cool and dreary end of the week leads into a continued stretch of slightly below average temperatures for the weekend. Temperatures remain on the cool side with chances for rain to start next week before a warm up in the second half of next week. Far off in the Central Atlantic, a rare April tropical storm (Arlene) has formed.

Rest of today – rains moved through overnight and lingering showers this morning should end within the next couple hours. Cloudy with high temperatures only in the upper-50s to around 60°F.

Saturday – despite winds turning to the north with high pressure moving in from the west, temperatures should still rebound into the low-60s. Partly to mostly cloudy skies.

Sunday – mostly cloudy to overcast with temperatures hovering around 60°F.

Monday – the next chance for rain comes in along with a developing coastal low that lingers through Tuesday. Timing of this coastal storm remains somewhat uncertain, so it could end up being somewhat of a pest early next week.

 

Rare April Tropical Storm
We’re still 2 full months off from the official start of the 2017 Atlantic hurricane season, which makes the formation of the first named storm of the season even more of a meteorological oddity. Tropical Storm Arlene will spend its life churning up the waters of the Central Atlantic without any impacts on land. It’s still worth noting that this is only the second time since the dawn of the satellite era that a tropical storm has been detected in April.

TS Arlene is the tight circulation located at around 50° W, 40° N

NYC Weekend Weather + Hurricane Matthew Update – Oct 6, 2016

The main weather headline for this weekend was going to be about possible impacts from Hurricane Matthew. I’m glad to report it now appears the storm will miss us, but the good news for us translates for doubly bad news for Florida. We went from a possible hurricane/tropical storm impact this weekend to a weekend where we expect to see some decent, fall-like weather.

Rest of today – sunny with a high temperature in the low-70s.

Friday – sunny, slightly warmer with highs in the mid-70s. High pressure remains anchored over the area, blocking the progress of Matthew northward, and also giving us great weather.

Saturday – a cold front will approach from the west, clouds will increase overnight and there is a chance for rain on Saturday. Mostly cloudy otherwise with highs in the low-70s. Part of the reason Matthew is expected to miss the Northeast is because this frontal boundary was faster to approach than was forecast earlier. This means it will have a role in pushing Matthew out to sea, instead of lifting it north towards the coast here.

Sunday – noticeably cooler with below average high temperatures only in the mid-60s and skies clearing.

Hurricane Matthew No Longer a Threat to the Northeast – Could Hit Florida Twice

As of 11AM EDT, the National Hurricane Center‘s advisory showed that Hurricane Matthew had restrengthened into a robust Category 4 storm with maximum sustained winds of 140mph. It had just moved past New Providence island in the Bahamas moving northwest at 14mph, having avoiding a direct landfall on the highly populated island where the capital Nassau sits. However, as we get more information in, it’s becoming clear that some areas of Haiti really got the worst case scenario. This video footage from the small town of Jeremie on the northern side of the western tip of the Tiburon Peninsula shows the catastrophic damage Matthew caused. Jeremie took a direct hit from the storm’s northeastern eyewall, the strongest part of the storm, as Matthew made landfall on Haiti as a Category 4 with 145mph winds. This gives you an idea of the raw power of the storm that’s now headed for Florida.

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Satellite image of Matthew at 11AM EDT October 6th, 2016. Below: radar imagery from Miami shows Matthew’s eye.

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Outlook for Matthew

Luckily for us, long-range forecast models show that Matthew no longer poses a threat to the Northeast. The flip side is that a fairly unprecedented scenario might befall Florida. Some models are suggesting that after Matthew moves offshore of the Carolinas, it may execute a large cyclonic loop, with the possibility of making a second landfall on South Florida later next week, albeit as a much weaker storm. First, Floridians all up and down the east coast, will have to contend with a dangerous Category 4 storm scraping along the shore or maybe making direct landfall. The coast scraper scenario would result in worse outcomes for Georgia and South Carolina, since reduced interaction with land will mean a stronger storm, as well as higher storm surge.

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NYC Weather + Hurricane Matthew Update – Oct 3, 2016

After a gloomy, but appropriately fall-like start October, this week looks like it will bring much improved weather. Temperatures are expected to be just below or at normal for the majority of the week. The big question mark in the long-term for weather in our region is the progress of Hurricane Matthew, which could impact the area this coming weekend.

Tuesday – mostly cloudy to start with gradual clearing and high temperatures in the upper-60s.

Wednesday – mostly sunny with high temperatures in the upper-60s. High pressure anchored over southeastern Canada will give us an extended period of nice weather.

Thursday – sunny, warmer with high temperatures in the low-70s.

Friday – sunny, with high temperatures in the low-70s.

Hurricane Matthew an Increasing Threat to the US East Coast

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Hurricane Matthew as captured by one of NOAA’s geostationary satellites on Monday, Oct 3 at 5PM EDT.

Hurricane Matthew poses an imminent and possibly catastrophic threat to Haiti, and portions of Eastern Cuba. Heavy rains from rain bands associated with the storm have already begun falling over Hispaniola and have hit Jamaica as well. Matthew is a potent Category 4 storm with maximum sustained winds at 140mph. It is expected to bring rainfall of 8-20″ across the region, with some places receive 7-11′ of storm surge.

Matthew has displayed a number of anomalous characteristics that have defied forecasters and experts best efforts at predicting its intensity. Matthew underwent a period of rapid intensification, going from tropical storm to a Category 5 hurricane with 160mph winds in just under 36 hours. This puts Matthew in an exclusive circle of just a handful of storms in recorded history that have accomplished this feat. Even more amazing, Matthew underwent this rapid intensification in the face of strong southwesterly wind shear that would typically stall a storm’s growth or weaken it.

During much of its life, a large area of intense thunderstorms has accompanied Matthew, at times exceeding the actual storm center in size. Scientists are uncertain as yet what role this feature had in Matthew’s unusual intensification. This feature has been impacting Hispaniola.

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Infrared satellite image of Hurricane Matthew as a strong Category 4, note the impressive area of intense thunderstorms east of the storm’s core.

Outlook for Hurricane Matthew

Matthew is expected to either skirt the extreme southwest peninsula of Haiti or make landfall there, then perhaps a secondary landfall on Eastern Cuba. The more interaction Matthew’s circulation has with the high terrain of these regions, the weaker it will get before entering the wide open, and warm waters of the Bahamas. It is expected to maintain major hurricane status (maximum sustained winds greater than 115mph) throughout most of the 4-5 forecast period.

Since even earlier today, major forecast models have come into much better agreement about the path of Matthew in the longer term. The unfortunate news is that the models have settled on solutions that push Matthew further to the west than previous runs. This dramatically increases the chances of a landfall somewhere on the Southeastern US, with Florida also in the range of possible tracks. Should this scenario unfold, we would be spared from a direct landfall here, but would still receive a storm of considerable strength with strong winds and heavy rains possible.

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Hurricane Joaquin Update – Oct 2, 2015

Good news to report regarding Hurricane Joaquin – since yesterday, forecast models have arrived at a much clearer consensus regarding the track of Joaquin once it leaves the Bahamas – and the resulting forecast track takes it well east of the US East Coast.

This means we will luckily miss any severe impacts from a landfalling tropical cyclone. However, with Joaquin to the south and a ridge of high pressure to the north, continuous onshore northeasterly winds will still present moderate coastal flooding issues. Temperatures will likewise remain cool under the clouds and onshore flow, with rain expected to continue from today until Saturday. Lingering showers may persists on Sunday.

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NYC Weather Update – Hurricane Joaquin in the Picture? – Oct 1, 2015

This week of damp, grey weather is leading up to a weekend when the uncertain future of Hurricane Joaquin may have an enormous impact on our weather. Since its formation earlier this week, Hurricane Joaquin has intensified steadily into a Category 3 storm currently spinning around the Bahamas. Joaquin’s future is still highly uncertain, and there’s been considerable spread between major forecast models as to where the storm will be at the end of the weekend. At this point, a landfall in the NYC region late this weekend is not out of the question.

Rest of today – cloudy and cool with high temperatures only in the mid-60s.

Friday – rain at times, windy and raw, with northeast winds in the 20-25mph range. It will feel like November with highs only in the mid-50s.

Saturday – similar to Friday in terms of sensible weather, with highs only in the upper-50s.

Sunday – this is where things get interesting depending on the track of Hurricane Joaquin. Depending on how closely Joaquin comes to hitting us, we could be looking at tropical storm conditions building through the day. If, on the other hand, it recurves out to sea, Sunday could be the best day of the weekend.

The Big Question: Where’s Joaquin Going?

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Currently, Joaquin is a Category 3 storm over the Bahamas, with noticeable central eye, and symmetrical outflow in satellite images. Joaquin has been moving southwest along the edge of a subtropical ridge. Joaquin is an environment favorable for continued intensification, sitting over some very warm water with moderate wind shear.

Forecast Track

Over the last couple of days, forecast models have been set in basically two camps, one curving Joaquin northwest into North Carolina or Virginia. The other camp continues to point to a recurvature of Joaquin. Given the large spread between the models, National Hurricane Center forecasters have been emphatic about the degree of uncertainty with the track forecast up to this point.

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Some major forecast models’ track forecasts for Joaquin
Official NHC track forecast
Official NHC track forecast

Potential Impacts

Regardless of the landfall point for Joaquin, it will be contributing to a plume of tropical moisture leading to widespread heavy rainfall over a large portion of the east coast.

With the persistent northeast winds ahead of the northward advancing Joaquin, coastal flooding is also likely to take place in flood prone areas.

5 day rainfall totals
5 day rainfall totals

 

NYC Weekend Weather – Aug 27, 2015

We have a simply splendid weekend on tap. Temperatures will be on the upward trend through the end of this week and into the weekend. The warm trend will continue into the beginning of next week, along with a return of more humid, dog days of summer type weather. Keeping an eye on the tropics, a great deal of uncertainty surrounds the future of Tropical Storm Erika, which could effect the U.S. East Coast in the long term.

Rest of today – beautiful, sunny skies with high temperatures in the low-80s. High pressure to the west is firmly in control, delivering this pleasant, seasonable weather.

Friday – almost a carbon copy of today, high temperatures in the low-80s with even fewer clouds as the high pressure center will be parked right over us.

Saturday – as the high pressure from the end of the week moves offshore and weakens, a subtropical high pressure center begins to take to control. This setup favors a warmer, more humid regime. Winds will shift to the southwest and temperatures will begin to climb into the mid-upper 80s.

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Sunday – a longer term trend of warm and humid weather, typical of late summer, will continue Sunday. Temperatures will again be in the upper-80s. This trend looks to continue well into next week.

Tropical Storm Erika

A tropical wave that moved offshore of West Africa late last week has tracked across the Atlantic, strengthening along the way to become the fifth named storm of the 2015 Atlantic Hurricane season. Tropical Storm Erika, like its predecessor Danny, is having trouble maintaining its strength due to the influence of dry air and hostile northwesterly wind shear. Due to this shear, Erika’s center of circulation is actually still somewhat exposed (see below), and displaced away from its area of heaviest thunderstorms, which is concentrated in the southeastern quadrant of the storm.

The long term prospects for the storm are highly uncertain due to a number of factors. Erika looks to be tracking over Puerto Rico and may interact with Hispaniola (bringing much needed rain), which would significantly weaken the already feeble storm. This could lead to it dissipating entirely. However, should the storm make it past this area of high wind shear and possible land interaction, it’ll end up in the very warm waters around the Bahamas. This would provide the fuel for it to intensify quickly into a hurricane which could then threaten Florida and the East Coast. Definitely worth keeping an eye on.

Satellite image of Erika, with exposed center of circulation circled in red
Satellite image of Erika, with exposed center of circulation circled in red

NYC Weather Update – Aug 23, 2015

A slow moving cold front brings an unsettled start to the week. Ahead of this cold front, temperatures will rise along with humidity, leading to a late-summer feel. Once this frontal boundary passes, high pressure to the west will allow for a cooler, drier Canadian airmass to enter the region, leading to more seasonable temperatures along with sunny skies.

Rest of today – a mix of sun and clouds continues with a small chance of some rain, with temperatures topping out around average in the low-80s.

Monday – as a cold front approaches from the west, humidity and temperatures will rise along with a south wind. There is some small chance for thunderstorms, especially west of the Hudson. Otherwise, expect a mix of sun and clouds with temperatures in the mid-80s.

Tuesday – with the cold front lingering in our vicinity, a small chance for showers and thunderstorms continues, along with warm and humid temperatures in the mid-upper 80s.

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Wednesday – the cold front finally pushes through Tuesday, and gives way to high pressure building in from the west on Wednesday. This will lead to comfortable temperatures in the low-80s with sunny skies.

Thursday – similar conditions to Wednesday, with sunny skies and a pleasant, comfortable high in the low-80s.

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A Note on the Tropics

We’re about to enter the most active period of the Atlantic hurricane season, and things have definitely picked up in the tropics. A series of monsoonal tropical waves are moving off of the cost of West Africa, giving rise to the potential for a couple of Cape Verde type tropical cyclones. This conveyor belt of tropical waves has already spawned this season’s first hurricane, Danny, which peaked as a major hurricane with winds of 115mph (Category 3) at the end of last week. Danny has weakened considerably, but could still bring some much needed rain to Hispaniola and Puerto Rico in the next couple days. Meanwhile, another tropical wave following on Danny’s footsteps could become Tropical Storm Erika in the coming days. Neither of these storms poses any immediate threat to the United States for the time being.

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