Posts

Steven Copertino

Cold Front to Bring Northeast Relief, Lee Becomes a Major Hurricane

/by

Good Evening! 

Today was yet another hot and humid day across much of the Northeast with highs reaching up into the middle to upper 80’s over much of the area. Coastal sections of New Jersey, Long Island, and Connecticut were able to see lower temperatures due to easterly winds off of the cool Atlantic where highs stayed in the upper 70’s and lower 80’s throughout much of the day. Much of the day today was quite sunny and clear, which further added to the “summer-like” feel in addition to dewpoints reaching up into the upper 60’s and lower 70’s. The good news is that a cold front is working its way into sections of western Pennsylvania and into portions of New York this evening, and will bring some welcomed change to the area as soon as tomorrow!

This front will continue to march along, but have little in the way of any precipitation associated with it due to a lack of deep moisture content from the south.  There may be some small showers and brief downpours as this front continues east and interacts with subtle mesoscale features, but overall the evening should remain dry once again. As we head into the very early morning hours of Thursday, we have to watch for an increased chance of showers and some gusty winds along with Mid Atlantic and Northeast coasts. By this time, the cold front will be interacting with Hurricane Maria, which will be located to the southeast of the Delmarva peninsula. Widespread shower activity is not anticipated at this for the New York metro area as this front steadily chugs east, but the front could slow down a bit and bring in some additional moisture once it nears the Massachusetts and Rhode Island area.

Loop of Hurricane Maria off the Mid Atlantic coast along with the cold front that will be steering it out to sea over the next few days (Simuawips.com)

Loop of Hurricane Maria off the Mid Atlantic coast along with the cold front that will be steering it out to sea over the next few days (Simuawips.com)

Thursday will be a much more comfortable day across the entire Northeast, with the mid level trough associated with the cold front moving into the region. Behind the cold front, we should see light winds out of the northwest, with mainly sunny skies. Dewpoints will also drop quite dramatically as well, so tomorrow should be quite a pleasant day compared to the past few. Highs tomorrow will range from the low to middle 70’s near the coast, with cooler temperatures in the mid 60’s to lower 70’s expected further away from the coast. Again, the area will remain rather dry due to a lack of moisture and this should last through tomorrow evening as well. Tomorrow night will be a nice change and certainly have more of a fall feel to it as radiational cooling takes hold and really allows temperatures to drop for the first time in a while. Lows tomorrow evenings should range in the upper 40’s to lower 50’s along the coast, with low to middle 40’s further north and west.

Friday and into the weekend looks to be much of the same, with much lower dewpoints, light winds, and mostly sunny skies with highs in the middle 60’s to lower 70’s through Sunday. The only real chance for showers looks to be on Friday evening and into Saturday morning as another cold front moves into the area to reinforce the cooler weather. The shortwave associated with the front will have limited energy and moisture to work with, so the threat of heavy rainfall seems quite low at this time. Overall, it should be a beautiful weekend for the area, but not quite fall weather yet!

Farther out, medium range guidance continues to suggest that a very large area of mid level ridging will develop over the eastern third of the nation by the beginning of next week. However, do to the positioning of this ridge, we may be able to escape the heat and humidity like we had this week due to the potential for an area of high pressure to bring more onshore winds. This will allow temperatures to remain in the middle to upper 70’s with some increased moisture and a few rain chances, though nothing looks too significant at this time. We may see this pattern persist into next weekend as well, with potentially warmer temperatures once again taking over, but we will have further updates on that later in the week!

Loop of the cold front driving out the high dewpoints in the area and ushering a more seasonable airmass for the next few days

Loop of the cold front driving out the high dewpoints in the area and ushering a more seasonable airmass for the next few days

Lee Becomes the Fifth Major Hurricane of the 2017 Season-Watching the Caribbean 

Hurricane Lee made a very impressive comeback from back when it died in the central Atlantic about a week ago now. Earlier this afternoon, the storm was upgraded to a Category 3 with sustained winds up to 115 miles per hour. Lee is thousands of miles away from land and will stay that way as it continues to accelerates to the north, but it may add to the amazing superlatives that this hurricane season has racked up so far. It could push 2017 ahead of 2004 for the most active 30-day period (ACE wise) in recorded history. Later in the day tomorrow, Lee will begin to feel the effects of higher wind shear, which should start to drastically weaken the cyclone until its absorbed by a larger system in the North Atlantic. Lee has had an impressive journey over the past week or so, and will be remembered as being one of the only major hurricanes to not affect land, thankfully.

Unfortunately, our eyes will be turning to the Western Caribbean as we said they likely would be back in last weeks posts. The global models are starting to really hint on a large gyre of tropical moisture festering and eventually moving north, possibly into the Gulf of Mexico. This is all very far out, but systems like these tend to take days before becoming a named system, and sometimes they just remain disorganized masses of thunderstorms that can produce widespread flooding. Regardless, we will be closely following any developments over the next few days since the Caribbean is the climatological breeding ground for strong cyclones in October, and we currently have very favorable conditions for a system to take advantage of if one does wind up forming. As of right now, I would say that there is a medium chance of tropical cyclone formation in the NW Caribbean and Gulf of Mexico in the 7-10 day period.

Animation of the ECMWF model showing a large, cyclonic gyre taking shape in the Caribbean/Gulf of Mexico in 6-10 days (Courtesy Phil Pappin

Animation of the ECMWF model showing a large, cyclonic gyre taking shape in the Caribbean/Gulf of Mexico in 6-10 days (Courtesy Phil Pappin)

For more information and posts like this one, make sure you sign up for Premium Forecasts — where multiple detailed articles, videos, and interactives are posted each day. Also, come interact with our staff and many other weather enthusiasts at 33andrain.com!

Have a great evening!

Steve Copertino

Miguel Pierre

Summer-Like Warmth Continues, Hurricane Maria Stays Offshore This Week

/by

Good morning! More summer-like weather from the weekend will continue today, as strong mid-level ridging continues to be over the Northeast and Mid-Atlantic. It will be hot and humid for late September with plenty of sunshine for today. More sea-breezes developing this afternoon, may keep temperatures a little cooler than on Sunday, especially closer to the coast. But high temperatures will likely reach the mid-upper 80s in many areas again. Some inland spots could reach around 90 degrees again. These temperatures will likely be a few degrees short of record highs for today.

Read more

Steven Copertino

Maria Finally Departs the Caribbean and Jose Fades. Whats Next?

/by

Good Evening

Back on Monday we highlighted the potential for Maria to become an extremely dangerous Category 4 or even 5 Hurricane before reaching the small island of Dominica in the Lesser Antilles, and unfortunately that is exactly what happened. Maria rapidly intensified into a Category 5 hurricane with 160 mph winds just before making landfall on the small island, and then preceded to head from SE to NW, leaving the entire island in its core for at least three hours. The storm was the second Category 5 land falling hurricane this season, tying the 2007 with Dean a Felix. Details are still very spotty, but the pictures, video, and first-hand accounts of Dominica are heart-breaking. Most, if not all of the homes on the island have suffered severe damage, with some houses being completely destroyed. Due to the topography of the island, devastating mud slides and land slides were common, which swept away homes, roads, and well-built concrete structures. Its hard to believe that we’d have a storm that would rival the total devastation that Hurricane Irma caused just a few weeks ago, but we could be looking at yet another situation  where an entire island community has seen complete devastation. With the peak of the Cape Verde season quickly coming to a climatotlogical end, we should see the frequency of storms impacting this region begin to wind down, but I would not be surprised to see one or two more systems during the month of October given the active state that we are currently in.

Damage from Hurricane Maria when it hit the island of Dominica as a Category 5 hurricane with winds of up to 160 miles per hour (Credit: The Guardian)

Damage from Hurricane Maria when it hit the island of Dominica as a Category 5 hurricane with winds of up to 160 miles per hour (Credit: The Guardian)

Due to the high, mountainous peak of Dominica and the amount of time that Maria spent traversing the island, the inner eyewall of the storm become disrupted and fractured, but not for long. On Tuesday the storm began to rapidly regain strength after dropping to a Category 4 hurricane. Recon missions throughout the day found that the storm had an incredibly compact eye of around 5-8 nautical miles and the winds rose from 155 mph to 175 mph during the course of the day, with the pressure falling to an incredible 908 millibars, making the storm the tenth strongest on record for the Atlantic basin.

Recon also released numerous dropsonde instruments which provide a vertical profile of various locations in the storm, and some of these probes happened to measure extreme winds of around 190-195 mph at the surface, but it is not certain whether these were instantaneous gusts or actually representative of the storms strength. Regardless, the storm began to approach the US Virgin islands late in the day on Tuesday and into the evening. Very deep convection began to develop quite rapidly around the center of the storm, and before long, concentric eye walls began to develop. This marked that the storm was about to attempt an eyewall replacement cycle before hitting Puerto Rico. It was clear that the storm would have issues completing this process and then intensifying once again due to the storms intensity and the size of the outer eyewall, but it also signaled for new dangers to arise. The storms wind field grew quite substantially as it approached Puerto Rico early Wednesday morning, causing the carious weather stations to be blown apart in addition to both weather radars on the island.

The storm raged ashore with winds in the 155 mph range, making Maria a strong Category 4 hurricane on the Saffir-Simpson scale. Maria went on to produce prolific flooding, wind damage, and cut a path of carnage across the island that would send all of its inhabitants into darkness as all of the power facilities went down during the storm. Details are also still rolling in slowly on the extent of the damage to the island, but it may be safe to say that the Puerto Rico that existed before Maria is no longer there. Estimates say that power may not be restored to some portions of the island for possibly up to 4-6 months. Additionally, much of the infrastructure will need to be rebuilt, which will be a daunting task in of itself. The next few weeks and months may be quite rough for the locals, but with resilience and endurance the people of the island will be able to overcome this disaster and restore their home to levels greater than before Maria.

GOES 16 imagery of Hurricane Maria making landfall on the island of Puerto Rico with winds of up to 155 miles per hour

GOES 16 imagery of Hurricane Maria making landfall on the island of Puerto Rico with winds of up to 155 miles per hour

Maria has since left the Caribbean, and land interaction along with an increase in vertical wind shear have been affecting the system. The storm weakened down to a Category 2 on Thursday, but has since regained some strength and is now a 125 mph Category 3 hurricane. The storm is currently located very close to the Turks and Caicos, producing winds up to tropical storm force on the islands along with torrential rainfall as it slowly heads NNW at around nine miles per hour. Maria should keep this heading over the weekend and into the early portion of next week, but some key aspects of this forecast remain in question. While it is quite likely Maria misses the United States, the American model has been trending strong with the riding out ahead of Maria in the past few runs, bringing the storm precariously close to the Outer Banks of North Carolina. Again, such a solution looks unlikely right now, but with the remnants of Jose still meandering around, we truly will not know just how close the storm passes to the east coast before it makes its famed passage out to sea.

Trend loop of the GFS model showing the westward trend over the past 5 runs (Courtesy of TropicalTidbits)

Trend loop of the GFS model showing the westward trend over the past 5 runs (Courtesy of TropicalTidbits)

So What Else? 

Well, we have the remnants of tropical storm Jose which has finally become post-tropical after 70 advisories by the National Hurricane Center. For reference, this storm has been ongoing since Hurricane Irma was north of Hispaniola! The remnants of this storm should gradually dissipate over the next few days and really should not be much of a threat besides increased wave action and showers. Elsewhere, Tropical Storm Lee has come back to life after shedding about three different low level circulations over the past three days and is located well out in the open Atlantic, just east of a large upper level low. Lee is an extraordinarily small system and is reminiscent of Hurricane Michael from 2012 in that of it is relying heavily on baroclinic process to form convection and strengthen. Given its size and the upper level conditions, I would give the storm a higher than normal odds of becoming a small hurricane over the next few days.

Lastly, our eyes turn to the western Caribbean as the month of September begins to fade. Medium and long range models are showing that this area of the Atlantic basin may become much more active during the next few weeks as a large area of upper level divergence sets up right over extremely warm sea surface temperatures of around 31-32 Celsius. This upper level divergence over very warm waters would promote a large amount of deep convection to form, which could eventually lower pressures in the Caribbean and cause a tropical system to form. This is all at least 8-12 days out at this point, but the signals are there that we should begin to monitor this region for potential tropical cyclone development as we near the beginning of October.

I will have a full update on Maria and any other threat that may pop up on Monday!

ECMWF model showing large scale rising over the western Caribbean in about 10 days. Conditions could become quite favorable for tropical cyclone genesis by this time.

ECMWF model showing large scale rising over the western Caribbean in about 10 days. Conditions could become quite favorable for tropical cyclone genesis by this time.

Have an excellent weekend!

Steven Copertino

Miguel Pierre

Jose Impacts on the New England & Mid-Atlantic Coasts

/1 Comment/by

Happy Tuesday! Hurricane Jose remains well offshore. But will still have some relatively minor impacts over coastal parts of the Northeast and Mid-Atlantic over the next few days or so. Meanwhile, more attention has turned to Hurricane Maria which has become extremely powerful Category 5 hurricane, as moved over Dominica last night. Puerto Rico and the Virgin Islands may take a direct hit from by Wednesday. But this article, will mostly discuss impacts from Jose

Based on latest observations and model guidance, Hurricane Jose will be tracking further southeast of the 40/70 benchmark, than previously expected. So only some outer fringe rain and wind impacts are expected for most coastal areas of between the Delmarva and New England through Wednesday. Showers and breezy conditions are generally expected, as outer rainbands from Jose push inland from off the ocean. Some locally heavier downpours with possibly higher wind gusts to around 40mph, especially along the New Jersey, Delaware and Long Island shores. But true tropical storm conditions aren’t largely anticipated.

Read more