Invest 98L Becomes TD 13

August 20, 2020

Last night Invest 98L was upgraded to Tropical Depression 13, the 5-day forecast is shown below. I'll explain a little about what the models are showing but the official forecast is what we should all go by to make any decisions.

The GFS operational model has started to see this system much better and now shows a strong category 2 hurricane making landfall around the Florida Big Bend area early next Wednesday. Just as a reference, the model run 6 hours before that showed a strong tropical storm making landfall in Louisiana. A few other models are showing development but not the Euro yet. I'd like to see more run to run consistency from the GFS and other models come on board around a consolidated forecast before I start trusting any one solution. The spaghetti models along with the GFS and Euro ensemble guidance are below. Notice that very few of the Euro's 51 members are showing development. I can't really say which of the two between the GFS and Euro are seeing the future environment correctly, it'll probably take another day or two to know for sure, but I'm leaning towards the GFS with its idea that we will have a potentially impactful storm making landfall along the northern to eastern Gulf Coast mid next week. It hasn't really made a lot of sense that no development was shown by the GFS up until last night and that the Euro still isn't showing any, most tropical meteorologists seem to be confused by this so I think the GFS now may be starting to see things correctly.

Invest 97L is still doing its thing and the outlook on its future is about the same as I mentioned yesterday. The track guidance may be starting to consolidate around a more westerly track in the Gulf with the intensity forecast maybe a touch higher. For the time being TD 13 seems to be the one to pay more attention to but we'll keep watching this as well.

Hopefully by tomorrow morning we'll see some better model agreement where we can start to feel more confident about a forecast.

Have a good day.

Chris

Tropical Update - August 19, 2020

August 19, 2020

There are still two areas being watched by the NHC, Invest 97L in the Caribbean and Invest 98L farther to the east with a third area off the coast of Africa that needs to be watched over the next few days. I'm not going to spend any time on the yellow area today. You can see these and their potential paths on the 2-Day and 5-Day outlook maps below. As of right now, the good news is that there doesn't seem to be a consensus that there will be a major impact from either 97L or 98L. That doesn't mean that there won't be, but it is not like we've seen in the past for some storms where the models are locked in on them being a serious threat. So for now we're still in the mode of watching and waiting for the forecast to consolidate. Don't be concerned yet, but don't let your guard down.

To give you an idea where 97L and 98L may track and how they may strengthen, let's look at some of the model plots starting with 97L.

97L tracks:

97L intensity:

98L tracks:

98L intensity:

There are additional model solutions than what I've shown above so keep in mind these are not the full range of possibilities nor are they a forecast.

97L is struggling to develop and it doesn't look like it has highly favorable conditions ahead of it for the near term. I think it is fairly certain that 97L will enter the Gulf late this weekend, but there is a huge spread on where it may go after that and I don't think the Gulf will be the most favorable for development. The consensus from the intensity guidance is for a tropical storm at the most at least for the near term. It sounds like a stronger storm may track more to the east and a weaker storm more to the west. That being said we're talking about 4+ days from now so we're at the limit of reliability for the models and the models haven't been doing well this year.  I didn't show the GFS or GEPS (Canadian) tracks for 97L because they're not that much different than the other group of tracks.

98L is looking fairly healthy and it is expected to slowly strengthen as it approaches the islands. What happens after that is uncertain and depends on its track, which you can see has a large spread as well. I'm also showing the GFS and GEPS (Canadian) model ensemble tracks because the other group seems to show a track in the Gulf and I want you to see that is far from certain. The intensity guidance is a little stronger and it is more likely we'll see this become a hurricane over the short term. In a general sense, a stronger storm in the near term would favor a more easterly track. That doesn't rule out a weaker storm initially that stays more on a westerly course and then strengthens later, it is just too far out to know at this time.

So we continue to watch and wait. Again, at least we're not staring down a couple of monster storms in the models at this point but we need to be prepared to see what happens when the forecast consolidates over the next several days.

Have a great rest of the week.

Chris

Update on the Tropics - August 16, 2020

August 16, 2020

Below is the 5-day outlook from the National Hurricane Center. As it was thought, activity is starting to increase in the tropics. It's still too far out to talk for certain about development or specific storm tracks but I think that will change some time this week. Operational models aren't showing a lot of development just yet, but the ensemble models, or at least some of the members, are. The operational models have done poorly overall this year so it is possible they're just not "seeing" the environment correctly yet. Either way, observed conditions and support from the ensembles is enough for the NHC to start identifying some areas of interest.

Please get your hurricane kit in order and have an evacuation plan if you have not done so already. I'll probably send out another update mid-week. Until then enjoy the rest of your weekend and have a great week.

Chris

     

Tropical Weather Update

August 10, 2020

There is not a lot of tropical activity to report this morning. The NHC is watching an area well out in the Atlantic designated Invest 95L that has a 60% chance of developing over the next 5 days. Models don't forecast a lot of development from this in the short term but it is something to watch.

Activity has picked up in the Eastern Pacific over the past few days in what has been a fairly quiet season over there so far. This is notable because an uptick in activity in the Eastern Pacific can foretell what may be coming in the Atlantic basin over the next few weeks. Several of the weather patterns that support tropical development move west to east. These can be monitored by other means but looking for development to our west can be helpful for forecasters.

Last week Colorado State issued an update to their seasonal hurricane forecast. Their forecast is now for 24 named storms, 12 hurricanes, and five major hurricanes. This is almost double the activity of an average season. The 9 named storms and 2 hurricanes we have already had count toward these totals. Other seasonal forecasts indicate about the same level of activity. We're about a month away from the climatological peak of hurricane season and it is generally expected that we'll see activity start to pick up over the next few weeks.

I'll let you know once something pops up we need to start watching. Have a great week.

Chris

Saturday Morning Tropical Update

August 1, 2020

I think the calendar is broken, I'm not sure how it can be August already...I apologize for not getting an update out yesterday. I wanted to wait until Friday to let the forecast for Isaias settle and then Friday got busy. I figured most of you were following things closely anyways.

Hurricane Isaias will continue its course up the east coast. Right now it isn't forecast to strengthen more than a category 1 hurricane but that could change some if it tracks more over open water. At a minimum it looks like it may bring hurricane or tropical storm conditions from Florida all the way to the Canadian Maritimes.

Looking at the rest of the tropics there are a few other areas of interest but no serious threats to land are currently expected. TD Ten located in the far eastern Atlantic may strengthen enough to get a name before it encounters hostile conditions and weakens. The orange 'x' is a strong tropical wave that may strengthen a little but it looks to take a path out to sea, maybe one near Bermuda, but no significant impacts are expected.

I'm not seeing much in the longer term and there's a possibility that the first part of August is quiet in the tropics. Things can change so I'll let you know if something pops up.

That's all I have for today. Have a great weekend.

Chris

Wednesday Morning Update on PTC 9

July 29, 2020

There's bad news and good news for residents along the Gulf this morning. The bad news is that the track of PTC 9 has shifted to the west with the center of the forecast track now showing the storm entering the Gulf on Sunday. Note that the cone is still fairly broad out to Sunday and that a more eastern track is still possible. The good news is that it looks like conditions in the Gulf may be hostile enough to limit intensification or cause the storm to dissipate altogether but it'll be a few more days before we're confident in this.

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PTC 9 has the wind strength to be a named tropical storm but I think there must not be enough of a well defined and closed off low pressure center for it to be officially considered as such. PTC 9 has been really big for a tropical wave with a broad circulation spread out over a large area. Generally if a wave develops it is favored that the circulation will consolidate on the north or northeast side of the circulation. With this wave most of the convection (storminess) has been on the southern or southwestern side and this has caused the circulation to consolidate more to the south. The initial NHC forecast tracks were based on the storm forming more to the north but now that it looks like it is trying to develop a tighter circulation on the southern side of the wave the track has been shifted to the southwest to compensate. This is one of the issues with forecasting tropical cyclone development. The storm track is based on the location of the low pressure center and until there's a defined center to feed into the models they're doing their best trying to estimate where the center may form. Because of this we have the bad news that this storm could enter the Gulf.  

So now back to the good news. First, the track of the storm is likely to be one that causes at least some if not a lot of land interaction through Hispaniola and the rest of the Greater Antilles which have mountainous terrain. The storm will also have to fight off some dry air so conditions for strengthening don't look that great overall. The best scenario for strengthening would be for the storm to thread the needle between the islands and the Florida Keys and form a bubble of moisture around itself to fight off dry air. I don't see this as being very likely. Additionally, both the Euro and GFS show a fairly strong trough moving in and stalling over the lower Mississippi Valley on Sunday. This trough will bring with it strong mid and upper level southwesterly winds that will impart a lot of wind shear on PTC 9 as it enters the southeastern Gulf, if that is its track. Both models currently show a weak storm surviving the trek into the Gulf through the islands that then struggles to maintain a circulation as it fights wind shear off the west coast of Florida. With both major global models showing this occurring 4 days from now we can have a fair amount of confidence in it but to really ease my mind I'd like to see this trend hold through Friday morning.

That's it for today, we just need to keep watching what happens. I probably won't send out another update until Friday unless things change significantly before then. Have a great rest of the week.

Chris

Quick Update on the Tropics

July 28, 2020

The NHC has designed the tropical wave that was Invest 92L as Potential Tropical Cyclone 9. I was going to wait another day before sending an update because there's still not a lot of confidence that models are seeing this system correctly. Even so there has been a trend towards a more northeast track as you can see from the cone and one that shows only slow intensification.

That's it for today, we'll have to keep watching how this evolves. Have a great week.

Chris