PTC Five Designated In The Atlantic

June 30, 2021

This afternoon the eastern most wave mentioned in my last update has been designated Potential Tropical Cyclone Five by the NHC, the forecast cone is below.

You'll note that the forecast has PTC Five becoming a tropical storm and maintaining this strength through five days. The NHC is not currently forecasting intensification for two reasons. First, the storm is moving quite fast and is expected to speed up some and maintain a high forward speed through about three days. A high forward speed creates wind shear which is typically detrimental to intensification. Second, beyond three days the track is quite uncertain and with the possibility of land interaction the intensity forecast becomes very uncertain. The NHC did note that their intensity forecast is at the low end of the model guidance (for the reasons previously described) so keep that in mind as more strengthening than shown is definitely possible.

For us along the Gulf Coast we're in a wait and see scenario where we won't have a good idea what the long term track and intensity will be until Saturday. At that point we'll know how well it survived the wind shear and what the land interaction possibilities look like. Spaghetti models show solutions as far east as a storm crossing Hispaniola and then recurving into the Atlantic to the storm making landfall in the Yucatan and continuing west and then everything in between. The bottom line is that it is possible there could be a tropical system of some kind in the Gulf early next week.

My next update will likely be on Saturday unless there's a change to the current level of uncertainty.

Have a great rest of the week.

Chris

Tropical Weather Update - June 27, 2021

June 27, 2021

Synopsis: There are a couple of systems being watched by the NHC but there is nothing for Gulf Coast residents to be concerned about at this time. The southeast Atlantic coast may see some minor impacts from a tropical depression or tropical storm on Monday. There are a couple of tropical waves in the eastern Atlantic that bear watching, but no strong signals for development currently.

Getting into the details, the 2-day and 5-day outlooks below show the two systems being watched by the NHC. 

The system off the east coast isn't a concern for most of us but for those in that area some wind and rain from a mid-grade tropical storm looks to be the worst case if it manages to develop. Out in the eastern Atlantic a tropical wave has a 30% chance to develop as it heads towards the Lesser Antilles. Models aren't too excited about this system and environmental conditions aren't the best so significant development is not expected. All the same these systems should always be watched just in case. Farther to the east there is another wave just coming off the African continent. You can see the large area of clouds just off the coast on the 2-day outlook. The GFS and Euro models (and their ensembles) show a stronger signal for this second wave but nothing to get excited about at this point. The first wave may try to develop around mid-week as it approaches the islands. If it can survive the eastern Caribbean, which is typically an unfavorable area for systems to develop, we may have a weak system to keep an eye on in the central Caribbean about a week from now. Overall chances of this look low. The second wave may get a shot at development towards the end of this week. If it does, it could be a threat to the islands and points west around the weekend or beginning of next week, perhaps the Bahamas as well if it pulls more to the north. If this occurs we'll want to start watching to get an idea where the long term track may lead, but we're 10+ days out at this point so there's a ton of uncertainty. To put this in perspective, early last week there was a lot of excitement about the first wave, only to watch the models back way off with nothing happening, so it turned into a non-event.

That's it for today, I'll probably send another update out next weekend unless things go quiet. You can find links to all my posts, the NHC graphics, and more at my blog: https://www.deepsouthwx.com/. As always if you have any questions let me know.

Have a great week!

Chris

Tropical Weather Update - June 21, 2021

June 21, 2021

Taking a quick look at the tropics this morning, Claudette has made its way to the northeast and is now a tropical storm again near the NC/VA border. Elsewhere, the NHC is watching a tropical wave located southeast of the Windward Islands for development. Currently they give this system a 20% chance over the next 5 days but it is expected that any development will be short lived as the system encounters unfavorable conditions to its west.

In the longer term we may see some hints at development from another tropical wave coming off of Africa Wednesday into the weekend. As with the system mentioned above any development looks to be short-lived. There has been some robust tropical wave activity so far this season but it is still a bit early for those kinds of storms. Also, around the weekend or beginning of next week a disturbance may try to develop in the southwest Caribbean and head north. There's not a ton of model support on this yet so we'll see how it goes.

That's it for today. If the probability for development in the Caribbean increases I'll send out another update towards the end of the week.

Have a great week.

Chris

Potential Tropical Cyclone Three Designated in the GOM

June 17, 2021

The NHC has designated the disturbance in the Gulf as Potential Tropical Cyclone (PTC) Three. The NHC gives this label to storms that they expect to become a tropical cyclone (TC) soon but they haven't quite got there yet. This allows them to start rolling out their different products and watches/warnings a little earlier than if they waited until a tropical depression had formed. Anyhow, now that you know that, you can take a look at the forecast map along with the wind speed and surge forecast maps. 

A tropical storm warning has been issued from Intracoastal City, LA to the AL/FL line. PTC 3 is expected to become a tropical depression tonight or early tomorrow with some slight strengthening to tropical or subtropical storm strength before making landfall in LA early Saturday. Heavy rain will be the biggest hazard. Three day rain totals through Sunday morning are shown below. Note that isolated areas may see significantly higher amounts and it is likely that rain will linger in some areas through the beginning of next week.

Along with heavy rain there will be an isolated tornado threat as well.

Unless there's a significant change to the forecast this will be my one and only email about this system.

Have a good Friday and a great weekend and stay safe.

Chris

Tropical Weather Update - June 13, 2021

June 13, 2021

The NHC is watching an area in the southwestern Gulf of Mexico for development. If it does develop it will be slow to occur with a 10% chance over two days and a 50% chance over five days. Designated Invest 92L, most models keep it bottled up where it is for the rest of the week before bringing it north across the Gulf this weekend. The short term window for development isn't very good but if it is able to survive it may have a better shot towards the end of the week. Right now a messy system with rain and wind, maybe as a weak tropical storm, moving north towards Texas and Louisiana around the weekend looks most likely. Any solution beyond midweek is not very certain so we'll need to keep watching but nothing too exciting is expected at this time.

Levi Cowan posted the first Tropical Tidbits video yesterday, he explains all of this nicely here: https://www.youtube.com/watch?v=O3el7qjBoOo.

That is all I have for now, I'll keep you updated if something changes. Have a great week!

Chris

Tropical Weather Update - June 7, 2021

June 7, 2021

Synopsis: development in the southwest Caribbean may be possible towards the end of the week but nothing to be concerned about at this time.

Yesterday evening an area to watch with a 20% chance of development popped up on the 5-Day Outlook. The text from the NHC states: "An area of low pressure is expected to develop over the southwestern Caribbean Sea by Thursday or Friday. Some gradual development will be possible thereafter as the system moves slowly northwestward toward Central America."

In the last update I mentioned that models were hinting at development towards the end of this week or through the weekend. That specific signal has more or less been dropped, this area highlighted by the NHC is something different. Models are still hinting at development but not until mid next week now. This time of year something called the Central American Gyre, or GAC, can form. The CAG is an area of stormy weather that can sometimes spit out a tropical disturbance. There is not a CAG yet but one is expected to develop. This is what models are hinting at and what the NHC is watching for. I have also included the Eastern Pacific 5-Day Outlook and the Climate Prediction Center's Tropical Hazard Outlook which show this possibility as well.

There's nothing to be concerned about right now. It'll be awhile before we need to pay attention if this area does produce a storm. As with the last update I'm mainly just making you aware that there is some noise about tropical development in case you see or hear something. If it helps, hurricanes are fairly rare in the month of June, statistically speaking.

Have a great week.

Chris

June 1st Tropical Weather Update

June 1, 2021

I hope everyone had a great Memorial Day weekend. Today is the first official day of hurricane season (yay?). There's not a lot going on in the Atlantic at the moment but I thought it was a good time for a quick update, you can see the 5-day outlook below. 

We've already had our first named storm, Ana, that wasn't noteworthy other than it continued the trend of having a storm before the official start of the season. Before I get to what the next few weeks may look like, I want to update you on a few other seasonal forecasts. NOAA's forecast which was issued on May 20 is calling for an above average season with storm numbers as shown in the graphic (https://www.noaa.gov/media-release/noaa-predicts-another-active-atlantic-hurricane-season). Interestingly, the Met Office in the UK is calling for an average season (https://www.metoffice.gov.uk/research/weather/tropical-cyclones/seasonal/northatlantic2021). 

We're probably going to see the chance for activity in the Atlantic pick up over the next two weeks. Activity in the Eastern Pacific Basin is picking up, they're already on their second storm, and I think we'll see that continue in the short term. Often an increase in activity to our west is a sign of things to come in the Caribbean (which is one of the hot spots this time of year) and sure enough several models are hinting at some development around the end of next week. It'll be this weekend or early next week before there is a better feel for what might happen so nothing to be concerned about right now. Climatologically we're in the part of the season where a storm can quickly spin up from the tail end of an old front or other disturbance so sometimes we get surprises, but at the moment nothing is expected for about 10 days.

That's it for today. As a reminder all of these get posted to my blog www.deepsouthwx.com and I have a Twitter account you can follow as well @DeepSouthWXUS. There are links to a variety of resources on the site.

Have a great week.

Chris