Detailed Forecast

Monday Discussion : Can’t Beat The Heat

The dog days of summer are here.  The pattern for the coming week looks very much like the pattern we’ve seen over the last month.  A large high pressure over the eastern part of North America will keep us hot and dry.  The heat over the northeast hasn’t been record breaking by any stretch, but it has been consistent.  Here’s a map of the temperatures across America during July.  You can see, that the northeast and Hudson Valley were several degrees above average.

So as we look to the start of the week… expect more of the same.  Increasing humidity levels, and mid summer heat.  Highs on Monday and Tuesday likely in the low 90s.  When you factor in the humidity, a heat index in the mid 90s are likely… even some upper 90s heat index values.

A Heat Advisory is in effect for Monday and Tuesday as a result.  The heat and humidity will be in place through Wednesday, before we have some relief in the form of scattered showers and thunderstorms by late week.  Make sure you take breaks from strenuous activity, as heat exhaustion will be possible.

Have a great start to your work week, Hudson Valley.

Tropical Storm Isaias Recap : 8/4/2020

The Hudson Valley does not experience tropical systems directly very often.  That’s a very good thing.  The topography and vegetation in our area are not conductive to sustained strong winds.  If a severe thunderstorm pushes through with 55mph+ wind gusts, that can cause power outages in localized areas.  So it comes as little surprise that with Tropical Storm Isaias left an ugly mark on our region over the past several days.

Reports of well over 300,000 power outages across the region.  Our friends at Central Hudson alone had nearly 115,000 outages… and other suppliers reported over 213,000 outages.  Many of these over 300,000 have been restored.  However, some may not have power restored until after the coming weekend.  That’s the kind of damage we saw in the especially hard hit areas of Orange, Southern Dutchess, Putnam, Rockland, and Westchester counties.

So looking back at the data so far, let’s start with the rainfall amounts, and those amounts were quite substantial…

This is a combination of rainfall map and rainfall reports from the National Weather Service.  The totals may be slightly difficult to see, but you can see that the heaviest rainfall amounts were focused in the western HV and Catskills.  This is due to the center of Isaias taking a track roughly from Sullivan County, through western Ulster County, and up into Greene County.  The heaviest rains were on the western half of the storm, and you can see how that played out in reality.  Newburgh only saw 1.81″ of rain on the eastern side of Orange county… while in the western edge of Orange county, Port Jervis saw roughly 4 inches of rain.  Flooding concerns were focused mainly in the Catskills, where some areas saw upwards of 5 or 6 inches of rain in Greene and western Ulster counties.

Rough Winds

When we talk about wind gusts… that’s where the bulk of the damage was generated.  We said this storm would have 2 different sides, the side with torrential rains… and the side with potentially damaging wind gusts.  So we just said the heaviest rains were in the Catskills… so that means the worst winds must have been in the SE Hudson Valley.  This wind gust map shows the storm over the course of roughly 6 hours, in 15 minute increments.

Wind Gusts from 12pm to 5:30pm

This is NY state, and it shows wind gusts in MPH.  The Hudson Valley is in the lower right quadrant, and you can see where the strongest wind gusts were focused.  Here’s a rough scale of the wind gusts on this map:
– Blue : less than 34mph
– Greene : 35mph to 46mph
– Orange : 47mph to 58mph
– Red : 59mph to 68mph
– Gray : 68mph or higher

The worst gusts start out in Orange, Rockland, Westchester county around 1pm… and push northward into Dutchess by 2pm.  The worst winds are roughly between 2pm and 3:30pm in Dutchess, Putnam and Westchester counties.  The closer to the NY/CT border you go, the worse the winds.  Here are the reported gusts from the NWS:

A peak gust of 61mph at Bannerman Island… but multiple reports of wind gusts above 50mph can be found.  The problem is not just the intensity of the peak wind gust… but the fact that gusts between 40mph and 60mph continued for roughly 2 hours in any location.  A strong to severe summer time thunderstorm has gusts of that magnitude for 10 or 15 minutes… the gusts from Isaias lasted nearly 2 hours, and the result was that many of the trees and power lines in the region could not handle the power of the winds.  The end result was what we saw… over 300,000 power outages in our region.

Hopefully in the coming days, we can get the damage cleaned up, and start getting power restored to all of our residents.  For now, please think of your fellow Hudson Valley resident, and lend a helping hand if you can.  We’re tough, Hudson Valley!  We wish you all a safe and healthy remainder of the week.

Wednesday Discussion : What a Difference a Day Makes

What a difference a day makes. A day after Tropical Storm Isaias dropped torrential rains and brought damaging wind gusts to the Hudson Valley… we have picture perfect conditions for our Wednesday.
 
Beautiful sunshine and blue skies, low humidity, and a NW breeze. Afternoon highs in the low 80s are expected. A very comfortable night tonight, with temps in the upper 50s, followed by another beautiful day on Thursday with low humidity and highs in the low 80s.
 
We’ll be watching an upper level coastal disturbance for Friday that could bring some clouds and scattered showers back to the region. For now, we’ll try and enjoy the nice weather, and use it as a chance to clean up and recoup from yesterday’s storm. A special thanks to all our men and women working tirelessly to restore power, and get us all back on our feet… especially our partners at Central Hudson. We’ll try to pull together some storm data tonight.
 
Everyone please try and have a nice afternoon!

Tuesday Morning Tropical Storm Isaias Discussion

A quick look at Tropical Storm Isaias, and you can see on the 2 hour radar loop that this system is moving FAST. Tropical Storm Isaias has winds of 70mph (as of the 8am update), but continues to weaken. It’s center is currently located over the Chesapeake Bay, as it races NNE at 33mph. It’s speedy movement will mean it arrives (and departs) a bit faster than earlier projected. We’re able to get pretty detailed at this point, so lets look at the timeline

Timeline:

– Now thru 12pm –
Scattered showers and downpours, relatively calm winds, gusting 10 to 20mph. A severe thunderstorm with strong wind gusts and possibly a tornado can’t be ruled out (less than 2% chance)
 
– 12pm to 2pm –
Increasing wind gusts and heavy downpours. Areas from I-84 on south especially will see moderate to heavy rainfall closer to 2pm. The SE wind gusts with the onset of heavy rain will be 30mph to 60mph, with strongest winds in higher elevations. This will be the front edge of the tropical storm, so banding rainfall and bursts of wind will be expected.
– 2pm to 4pm –
Height of the storm! Center of Isaias expected to move right over the Hudson Valley. Ahead of the center, is where the worst weather will be. Strong SE wind gusts between 30mph and 60mph are possible, along with wind driven rainfall. Flash flooding is possible in areas where heaviest bands persist… but the area of heaviest rainfall with Isaias will likely be in eastern PA up toward Binghamton. For that reason, wind gusts in our area will be a considerable concern… and scattered power outages are possible due to down trees and power lines. 1 to 3 inches of rain are possible for the eastern half of the Hudson Valley, with 2 to 5 inches possible in the western HV and Catskills.
 
– 4pm to 6pm –
Heaviest rain shifts north of I-84… as heavy rain begins to taper off in the lower Hudson Valley toward 6pm. Winds will diminish for a time, as the front edge of Isaias pushes north of our region. Winds will intensify again as the wind wraps around the back side of the storm, so expect strong wind gusts out of the NW between 20mph and 50mph, even after the rainfall stops.
 
– 6pm to 8pm –
Rain tapers off from south to north as Isaias exits. Winds will be quite strong and gusty out of the NW… gusting between 20mph and 50mph at times.
 
We’ll try to have more updates as the front edge rain shields arrive in the Hudson Valley between 12pm and 1pm. Once again…
 
WORST OF THE STORM:
1pm to 4pm from I-84 on south
2pm to 5pm from I-84 on north

Monday Afternoon Tropical Storm Isaias Discussion

With Tropical Storm Warnings posted for the lower half of the Hudson Valley (Orange, Rockland, Putnam Westchester), it’s likely that many of you may be feeling a bit of angst and uncertainty this afternoon. This short discussion will try to clear up a few basic points.
What:
– Rain… heavy at times Tuesday afternoon.
– Increasing winds of 10mph to 25mph, gusting over 35mph
– localized wind gusts over 50mph possible
– Rainfall amounts of 2 to 4 inches… locally 5″+ possible
 
When:
– 6am to 2pm : Rain showers likely, periods of heavier rain possible
– 2pm to 6pm : Isaias approaches, increasing gusts and downpours
– 4pm to 10pm : Worst of the storm, periods of torrential downpours
as well as howling winds, gusting 35 to 50mph (possibly over 50mph)
 
Where:
– The entire region will experience the affects of Isaias
– Heavy rains expected for all locations
– Gusty winds over 30mph possible for entire HV
– Strongest wind gusts (over 50mph) likely south of I-84
 
Tropical Storm Isaias will likely undergo a brief period of strengthening before making landfall near the NC/SC border. From there, it will push NNE and head toward the Hudson Valley. It will spread rain northward, well in advance of the center of rotation, so rain showers are likely most of the day on Tuesday. The storm will approach the region between 2pm and 8pm. The winds will increase in that time frame, gusting over 30mph at times, mainly as the outer bands of Isaias rotate into the region. The worst conditions will likely be from 2pm to 10pm on Tuesday. During that time, gusts over 35mph are possible, with the highest chances for damaging wind gusts over 50mph being in areas east of the Hudson River, and also in areas further south (south of I-84). The effects of this storm for the region will be like a powerful nor’easter… with some potential for wind gusts that could exceed 40mph, which is what has prompted the Tropical Storm Warning for portions of the area.
 
We would like to stress, that while some details have changed, the general expectations with Tropical Storm Isaias have not changed. The expectation of a track further west has resulted in expectations for slightly stronger wind gusts than we were initially projecting. This continues to be a potentially significant event, and bares watching. We will try to have more frequent updates as we approach the storm’s arrival.

Sunday Night Tropical Storm Isaias Update

Currently Isaias sits off the East coast of Florida, it has been looking healthier today as it was able to escape dry air, sheer and the higher terrain of Hispaniola and is now within the favorable warmer Gulf Stream waters.
A strong high pressure in the central Atlantic coupled with a large trough over the Eastern Conus will leave very little options for the further track of Isaias. All model guidance is locked in on a track that brings the center of circulation up the eastern seaboard and potentially through parts of our region.
Here are the rainfall projections from the GFS and European models…
GFS Rainfall Projection
European Rainfall Projection:
As you can see there are only small track variances between them, only thing we can be confident on, is the fact that a widespread heavy rainfall is likely, with rainfall amounts between 2”-6” possible. Something that will bare watching is the chance for a “PRE” which is short for a Predecessor Rain Event which if you are bored and want to geek out, you can read about here…. https://journals.ametsoc.org/mwr/article/138/8/3272/71161/Predecessor-Rain-Events-ahead-of-Tropical-Cyclones
In laymen’s terms this is an event in which heavy rainfall breaks out ahead of an incoming tropical system, this is further enhanced by the trough that is draped across the region as it causes moisture and heavy rain to surge along this boundary, any heavy rain that occurs Tuesday in advance of the main rain shield associated with the system, may exacerbate any potential for flooding and would need to be monitored.
In terms of wind gusts, the friction of land will always keep the worst of the wind along the coast, but the models are supporting tropical force wind gusts across our southern and eastern counties, this combined with soaking rainfall may lead to scattered outages.
GFS Model Wind Gusts
European Model Wind Gusts:
The final track and intensity will determine if our impacts are on the high end or low end of this evenings guidance. With the threat of today’s severe weather behind us we are now moving on to tropical storm coverage.
If you have plans for Tuesday please factor this into those plans, most of Tuesday looks unsettled with rain and wind intensifying by later in the day. Stay tuned for more updates.

Sunday Afternoon T-Storm Potential

The humidity is very high across the region this afternoon. Temperatures have been holding in the mid and upper 70s, thanks to the morning rain showers… but it feels quite uncomfortable. Now we’re beginning to see the sky brighten a bit, and even some breaks in the clouds. That’s allowing temperatures to climb, and we’ll be into the 80s before long.
This will cause our T-Storm threat to increase over the next few hours. Some guidance does suggest that a few supercell T-Storms could develop randomly around the Hudson Valley.
There is considerable atmospheric sheer today, which could lead to rotation within those storms. As a result, the threat for a stray tornado cannot be ruled out. These storms are equally possible no matter where you are located within the HV today. For context and perspective, the threat of severe weather occurring within 30 miles of your location is less than 30%… and the threat for a tornado occurring is less than 5%. However, the potential for severe weather is present today, and everyone should exercise measured caution, and remain alert.
 
We will try to share any alerts that are issued this afternoon. This is a tricky forecasting situation, because the clouds and showers from this morning may have stabilized the atmosphere enough to where nothing develops. However, it’s always best to be cautious, and the rest of the atmospheric conditions are favorable for severe weather. So keep your eyes and ears open this afternoon.

Sunday Discussion : A Complex Severe Threat

Isolated thunderstorms will be possible Sunday afternoon through early evening ahead of a cold front. Recently, some data has been hinting toward a potentially severe event. Unlike past events, this is an extremely complex forecast with many driving factors. While potentially widespread, conditions leading up to the event may very well also hinder development. The main question will be whether storms materialize or not.

Timing: The main severe threat appears to be anytime after 12:00 noon through sunset.

Main Threats: All modes of severe weather are possible, including damaging winds, large hail, heavy rainfall, and an isolated tornado.

Midday tomorrow will feature an advancing warm front, which will cause clouds and scattered showers throughout the region. Behind the warm front will be an extremely moist air mass (dew points in the mid-upper 70’s). This will help result in high CAPE (Convective Available Potential Energy) values of up to ~3,000 J/kg, which is extremely favorable for severe weather development. Also, there will be a good deal of shear, which could allow for a few cells to rotate, resulting in an isolated tornado or two. While likely not a widespread tornadic event, it cannot be completely ruled out at any given location. The Storm Prediction Center has placed nearly our entire region in a slight risk (level 2 out of 5) for severe thunderstorms.

Simulated radar for Sunday (Aug 2nd) :

Conflictingly, many model runs show lingering cloud cover after the warm front passes, which will put a cap on any convection. Also, widespread cloud cover will not allow for surface heating, which is essential for updrafts. This appears to be the case on the most recent run of the Nam 3 km, which doesn’t show much convective development due to cloud cover. While a possible solution, it will only take a couple of breaks of sunshine to create a very unstable atmosphere, resulting in severe thunderstorm development. Like always, we will monitor this situation and give updates as we get closer in time.

Have a great evening!

Kyle

Weekend Discussion : Eyes on Isaias

Our weekend weather appears rather quiet.  Some standard summer weather to open the first few days of August.  Nothing that should have major impacts on your weekend plans.

So as we turn the calendar to August in the Hudson Valley, it’s the tropics that will grab our local attention.  On Friday, Hurricane Isaias formed in the Caribbean, and as you can see by the 11pm Friday advisory… it’s got the eastern US within its sights.  The ‘cone of uncertainty’ with Isaias is relatively narrow… which means that we have a fairly good idea of what to expect with the track.

You’ll easily notice the upper air pattern provides a path right up the eastern seaboard for Isaias.  An approaching upper level trough will push toward the east coast ahead of Isaias.  At the same time, a large upper level ridge over the Atlantic will be sliding further east.  The area between the two features will be where Isaias makes it’s path.  The biggest uncertainty, is exactly where these features shown above are positioned.  This will mean the difference of a few hundred miles in the track, and the position of the heaviest rains in the coming days.

As it stands right now, this could be the rainfall scenario for the Hudson Valley between Monday and Wednesday…

A period of rain and thunderstorms could develop out ahead of Isaias on Monday, followed by the remnants of Hurricane Isaias on Tuesday.  All told, 2 to 5 inches or rainfall could be possible… with localized amounts over 6″.  The key to everything, is the track.  Which we just mentioned could shift a couple hundred miles either way as it moves up the east coast.  You’ll see in the graphic above, the rainfall swath is now extremely wide… so the amount of projected rainfall is dependent on the path of Isaias.  For that reason, you’ll want to keep an eye on the forecast as we are able to focus in on the details a bit better.

Finally, just to bring some piece of mind to some of you.  Any time we are talking about a tropical storm, one of the first things some people think of, is wind damage.  For the Hudson Valley, Isaias does not present a major concern with regard to wind.

This map shows the maximum wind gusts up and down the east coast from what would be Tropical Storm Isaias.  There are a few hurricane force gusts into parts of Virginia and North Carolina… but further north, gusts up to 50 or 60 mph are possible.  The black curve represents the track Isaias takes on this solution.  This is probably about as far west as Isaias is expected to track (but once again, we need to monitor it closely).  Notice how the strongest wind gusts are to the east of the center of circulation.  So unless Isaias were to take a track even further inland (which the cone of uncertainty suggests is not likely), the strongest wind gusts over 35mph, would be east of our area… mainly over Connecticut and Long Island.  So as you can see, wind damage is not the real concern at this moment… it’s rainfall.

But as always with a situation like this, the details should come into clearer view as we get closer to the event.  Be sure to check back for updates as we get closer.  Have a great weekend!

Tuesday Discussion : “Dog Days” Of Summer

Today will be another hot one throughout the Hudson Valley. Southern regions will see highs in the mid-80’s to near 90° with dew points in the low 70’s. As a result, a heat advisory is in effect for Orange, Putnam, Rockland & Westchester Counties, with heat indexes in the mid-90’s this afternoon. Northern areas will likely stay slightly cooler, especially in the Catskills, with highs near 80°.

A few isolated thunderstorms are possible this afternoon ahead of a cold front (30-40%). Timing appears to be anywhere between 1-7 pm. This will not be a widespread event and while most locations will stay dry, any storm that does form could produce gusty winds and heavy downpours. The Storm Prediction Center has placed our region in a marginal risk (level 1 out of 5) for severe thunderstorms today as a storm or two may approach severe thresholds.

Enjoy your Tuesday!

Kyle