John Homenuk

NYC Forecast: Cool, pleasant weekend ahead

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The past few days have been sunny, cool and pleasant. You wouldn’t know it though, as smoke from wildfires has obscured much of the sunshine. Hazy skies will persist for another day or so until a frontal boundary swipes the smoke away later Thursday. The weekend will feature cooler temperatures and pleasant conditions.

NYC QuickCast

This afternoon: Pleasant and warmer than yesterday. Highs in the mid 70’s. Hazy skies continue with wildfire smoke overhead.

Tonight: Partly cloudy, with lows in the mid 60’s. A bit warmer than the past few evenings.

Thursday: Warmer and hazy again. Highs in the middle to upper 70’s. Increasingly cloudy late, with a chance of showers after sunset.

Weekend Forecast: Wonderful Autumn weather

A frontal boundary will approach the area late Thursday into Friday, with the opportunity for clouds and showers. These will mostly be sporadic in nature and low in terms of coverage. The front will cross the area on Friday, sweeping away the thick plume of wildfire smoke which has remained over the area for several days.

Temperatures will average several degrees below normal this weekend as high pressure settles in.

Later Friday into Saturday, a large area of high pressure will sink southward into New England. A northerly component to the wind will usher in cooler air from Canada. The airmass will be characterized by temperatures several degrees below normal.

With a large high pressure overhead, expect plenty of sunshine (no haze, either!) on Saturday and Sunday. Temperatures will be quite cool, with lows in the upper 40’s and lower 50’s and highs in the mid 60’s. It truly does look like a spectacular Autumn weekend with very few hazardous weather concerns to speak of.

Teddy will pass off the East Coast early next week

Tropical Storm Teddy, which is currently thousands of miles away in the Southern Atlantic, will move northwestward towards Bermuda this weekend. The system is expected to strengthen quite a bit as it does so, with the National Hurricane Center predicting a Major (Category 3) Hurricane.

Almost all ensemble data agrees that Teddy will be a few hundred miles off the east coast by Monday.

Forecast model guidance suggests that the storm will then turn northward, interacting with another disturbance over the northwest Atlantic Ocean. This will bring Teddy close to parts of the Gulf of Maine or Newfoundland by next week.

Impacts in the NYC area are expected to be limited, but may include rough surf and large waves as the storm passes by off the coast. Interests in New England and Eastern Canada should pay close attention to forecasts over the next few days as the track of the system may still change.

John Homenuk

Smoke from Western US wildfires reaches NYC

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Smoke from wildfires in the Western United States has reached NYC today. The sky will remain hazy and milky throughout the day as a result. The thick plume of smoke will remain 15,000 to 20,000 feet above our heads, limiting ground-level effects.

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John Homenuk

Cooler air expected in the Northeast, Sally to impact Gulf Coast states

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NYC Forecast Briefing: A few sprinkles or showers will move through the area this evening, but the majority of Sunday is now expected to be pleasant. Cooler than normal air will move in to the area for a few days behind a frontal boundary. Additional rounds of cooler than normal air will occur late this upcoming week and weekend. Meanwhile, Tropical Storm Sally continues its trek through the Gulf of Mexico and may impact parts of the Gulf Coast within a few days.

NYC QuickCast

This afternoon: Mostly pleasant conditions and seasonable temperatures are expected. Clouds will increase late. High temperatures will reach the middle to upper 70’s

Tonight: Cloudy with a few showers, especially north of the city. A bit warmer, with temperatures only falling into the middle 60’s.

Monday: Plenty of sunshine, less humid. High temperatures in the middle to upper 70’s with a light northerly breeze.

Northeast US Forecast: Cooler than normal air on the way

Behind a frontal boundary that will impact the area with some showers late Sunday evening, high pressure and cooler than normal air will move into the Northeast states. This airmass will also be characterized by lower dew points, helping the airmass feel refreshing and crisp.

This airmass will last for at least a few days, with very pleasant weather likely as a result. High temperatures for the rest of the week should average in the low to mid 70’s, with plenty of sunshine and very few weather hazards as high pressure dominates.

Temperatures will temporarily warm up again by the middle part of this week. A storm system moving through Southeast Canada and New England will eventually move near the area (likely from Thursday into Friday). A few showers are possible as this system passes by.

More importantly, though, the storm will bring the first really crisp airmass with it. After a front passes the area on Friday, much cooler than normal temperatures are likely next weekend. The last Euro Ensemble suggested temperatures 5-10 degrees below normal, on average, from Saturday into Monday.

Pictured above, a mid/upper level trough is forecast to slide through Southeast Canada. This trough is anomalous in its own right and features some very cool and low dewpoint air. Synoptically, this supports temperatures at least several degrees below normal for a few days in the Northeast next weekend – which matches up quite well with what most guidance is suggesting.

Get your pumpkin spiced lattes ready.

Tropical activity continues to ramp up, Sally a tropical storm

Tropical Storm Sally formed yesterday, and is expected to continue a trek into the northeast Gulf of Mexico today. The storm is currently encountering light to moderate northwesterly shear, which is tilting thunderstorms off to the east of the storms center. This is preventing the system from strengthening too much as of this morning.

The latest shear analysis near and surrounding the storm suggested 10-20 kts (averaging around 15 kts) of northwesterly wind shear. Visible satellite imagery shows that convection is biased to the southeast side of the storm, and this northwesterly shear is likely partially to blame for that.

Sally is also a very broad system, with tropical storm force winds extending quite a bit away from the center. This should also keep the system from strengthening significantly today, at least until the storm can organize a more substantial inner core and tighten up the spatial extend of its maximum wind.

This shear is expected to gradually weaken over the next 12 hours, so the storm may be able to organize itself a bit further. The National Hurricane Center forecasts the storm to strengthen to a hurricane before it makes landfall near the Louisiana coastline on Tuesday.

Most forecast model guidance is now in good agreement regarding the storms track and strength, with ensembles agreeing that the storm will move towards the Louisiana Coast as a Category 1 hurricane. Still, with relatively low shear and warm water temperatures, it is important to keep a close eye on the storms strength and possibly of intensification.

The 06z Euro Ensembles were in generally good agreement in regards to the storms track, bringing the system near the Louisiana coast early next week. Still, some members were stronger and slower with the storm – with deeper pressures indicative of a more substantial system.

Sally is likely to bring multiple weather hazards to the areas it impacts regardless of strength. The system is expected to slow down considerably, which will lead to a high likelihood of torrential, flooding rainfall. Sally remains trapped in a pocket of very moist air throughout the atmospheric column. This means that the system will not have much dry air to deal with, even in the mid levels of the atmosphere.

As Sally approaches the coast, steering flow will weaken and the storm will become “trapped” under a mid level ridge. This suggests that the system will slow down considerably near the Gulf Coast, while tropical moisture pools over the area. As a result, torrential and flooding rainfall is possible.

The Euro Ensemble is strongly suggesting the possibility of prolific rainfall amounts, with the ensemble mean suggesting over 10 inches of rain along parts of the coast. Actual amounts could be much higher than that in areas that receive “training” of tropical moisture – which occurs when areas of heavy rain move over the same regions over and over.

Additionally, some storm surge is possible as the system moves towards the Gulf Coast. The National Hurricane Center is forecast over 3 feet of storm surge in some areas that are highly susceptible to storm surge damage.

We recommend checking out the National Hurricane Center’s latest hazards page and key points in order to help develop a plan for you and your family if you live in those regions.

John Homenuk

NYC Forecast: Showers Sunday, pleasant otherwise

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Seasonable conditions are expected for the remainder of Friday and Saturday. Temperatures will average near or slightly below normal, with lower humidity. Showers are expected as a front approaches the area on Sunday. Pleasant weather will return next week.

QuickCast

This afternoon: Calm conditions are expected to continue with temperatures in the low to mid 70’s.

Tonight: Mostly clear with temperatures falling into the 50’s. Low dew points will keep the air feeling crisp and refreshing.

Saturday: Plenty of sunshine, with pleasant weather expected. High temperatures will reach the lower to middle 70’s once again. Clouds will increase later Saturday and Saturday evening.

Discussion: Showers Sunday, pleasant conditions return thereafter

Forecast models are in good agreement that a frontal boundary will approach the area on Sunday. This will lead to increasing clouds and showery conditions throughout much of the day. It remains to be seen exactly how quickly these showers actually approach the region, as recent model guidance has slowed the frontal boundary down. A slower frontal approach could mean showery/drizzly conditions, but no true steady rainfall on Sunday. Either way, showers are expected later Sunday night.

Showers will approach the area from the west later on Sunday evening.

Recent runs of the ECMWF, for example (pictured above) have continued a trend towards a later frontal passage. That trend has also been accompanied by a drier tendency, which is obviously good news if we hope to salvage Sunday. Forecast soundings show relatively limited moisture in the atmosphere until the front approaches, but that moisture is in the low levels. This suggests that cloudy and drizzly conditions are most likely on Sunday. When the front does approach, some periods of steadier rain are possible – but the rainfall amounts won’t be the real story.

After showers wrap up later Sunday into Monday morning, high pressure will return to the area. Calm and cool conditions are likely on Monday, with high temperatures only reaching near 70. Plenty of sunshine and gradually more noticeable warmth is expected throughout the week. Temperatures will return towards 80 F by the middle to latter half of the week, particularly from Wednesday into Friday.

Tropical activity expected to ramp up again next week

The National Hurricane Center is monitoring several different areas for tropical development, in addition to tropical systems Paulette and Rene, which are already ongoing. Both of those systems are expected to recurve harmlessly away from the United States.

In the Gulf of Mexico, NHC is monitoring Invest 96L, which may form into a tropical system after it passes Florida this weekend. The system will remeerge into the Gulf of Mexico and may strengthen again before it reaches the coasts of the Northeast Gulf of Mexico.

NHC is monitoring several areas for tropical development in the next five days.

Meanwhile, Invest 95L is organizing itself off the coast of Africa and will continue its trek westward over the next few days. NHC says this system has a high chance of developing into a tropical system. Most forecast model guidance suggests this is a system to watch closely as it evolves towards the Caribbean in the next several days.

There is a great deal of uncertainty regarding 95L’s organization over the next few days. Much of that uncertainty stems back to the systems convective developments in the next 24-48 hours, and where the low level center organizes and becomes dominant. There are multiple convective complexes currently battling for control, and forecast models are struggling to pin down which will become the “leader” so to speak.

Trends over the last few runs of deterministic and ensemble guidance have suggested a more westerly surge of convection, with a dominant low level center organizing by Sunday. This tends to support a more westerly track with the system instead of an early recurve into the Atlantic Ocean.

At this range, there is not much for us to do other than monitor the convective organization of the system and monitor resulting ensemble trends. There is a good chance that the system will end up somewhere near 50 W by early next week, at which point we should have a much better idea where it will be heading – notice the inflection point among ensembles near that point, where some are heading northward and others almost due westward.

If you’re like me, you’ll be watching satellite all weekend. If you’re not, check back in for updates in the next few days! Have a great weekend y’all.