Slight Chance of Severe WX Today Followed by Cold Air

 November 29, 2020

The Storm Prediction Center (SPC) has issued a Slight (yellow) risk for severe weather near the FL and AL coasts with a Marginal (dark green) risk extending a little farther inland in southern AL today through tonight. In the Slight risk area there is a 5% chance of tornadoes and damaging winds. The 5% damaging wind risk extends throughout the Marginal area but with the tornado risk reduced to 2%. Thunderstorms will develop this afternoon as a warm front lifts north ahead of an approaching cold front and will persist until the cold front passes late this evening. There is a bit of uncertainty with this forecast and the SPC expects severe storms to only occur in isolated areas.

After the front passes we can expect several days of cold and sometimes breezy weather with a night or two of freezing temps almost all the way to the beaches. Northern AL and TN may even see some winter precip on the back side of the cold front. Lows may reach the upper 20's even in the northern FL Panhandle with Northern AL well into the mid to low 20's, eastern TN may see one night in the upper teens in places. We should see another weather system sometime between midweek and the weekend. There is a general pattern in place that will keep cooler than average weather in place maybe through the end of the second week of December with precipitation expected to be mostly below normal for this time of year.

That's it for today. Keep an eye out on the weather and have multiple ways of receiving alerts if you're in the severe weather risk area. Some of us haven't experienced freezing weather this year so it's time for us to protect our outdoor plants. Have a great week.

Chris

Last Tropical Update of the Season? Also a Look at Other Weather

November 22, 2020

The tropics look like they're finally quieting down. The last area of interest we had in the Caribbean didn't materialize thankfully. You can see the NHC is watching an area off the East Coast. Development changes don't look very good but if something does develop it'll go out to sea. All other areas look quiet with nothing significant to note on the models. Several trusted sources seem to think we may be done for the year, let's hope so... Hurricane season doesn't officially end until the end of the month and we've actually had systems develop into January. All the same chances for a significant storm are rapidly diminishing. This will be my last update on the tropics unless something significant pops up. As I get time I may recap some of the interesting stats and storms from the 2020 season.

Up here in the mid latitudes we're starting to get into the typical winter weather pattern. Before we get to that, let's look at the winter outlook. The La Nina pattern that has been partially responsible for our active hurricane season will also affect our winter weather. Below are the winter temperature and precipitation outlooks from NOAA. The southeast is forecast to be warmer and dryer than normal for the period from December to February. La Nina doesn't always produce this pattern and seasonal forecasts can often be wrong, but this is currently what we can expect. Note that even if these forecasts are correct that doesn't mean that we won't get cold air or some good rain showers as the winter progresses.

Taking a look at the near term we'll have a series of fronts move through over the next 7 days. The first front is currently pushing south through northern AL and TN. It is producing rain but it is expected to dry out as it keeps moving south. The next system will come through about midweek bringing rainy and stormy weather. It looks like it'll clear the area by Thanksgiving morning but there could be a few lingering showers in the eastern Panhandle. After that a messy series of systems will approach from the west on Friday with rainy and stormy weather lasting through the weekend. Right now severe weather chances don't look too high but that is something to watch for this time of year. Some areas could see fairly high rain totals through 7 days, with most of it coming from the weekend system. Temps will dip a little as each front clears out but I don't think we'll get too far below normal this week. Around the first of the month we may see quite a big dip with low temps near freezing or below from Montgomery north and lows potentially in the 30's from there south to the coast. As we've seen in the past this info should be pretty reliable out to midweek but it is subject to significant changes beyond that.

That is all I have for today. Now that the tropics are quiet I'll reduce the frequency of updates to every week or week and a half unless extreme or severe weather is threatening.

Stay safe and have a great Thanksgiving.

Chris

Tropical Weather Update

November 15, 2020

There are two storms on the NHC outlook map this morning, Theta and Iota. Theta formed way out in the eastern North Atlantic and has been moving east. It hasn't been a threat to land but it may eventually bring some stormy weather to the archipelago of Madeira and parts of Europe. Iota formed from Invest 98L in the Caribbean and has been moving west. In a year of records, it had the strongest initial forecast for any storm when it first became TD 31 on Friday. It is now a hurricane and is forecast to become a major hurricane and make landfall in Central America near where Eta did. Iota is expected to stay on a westward track and not come north.

In the longer term there is the possibility of more tropical development in the same location in the Caribbean later this week through the weekend. Right now the signal isn't very strong, but it's something to keep an eye on.

In other weather there is currently a front moving through the Southeast, some of you in northern Alabama and Tennessee have already experienced some stormy weather from it. It looks like the rain chances dimension as the front pushes south. On the coast the NWS forecast only calls for "a stray light shower or sprinkle." Temps will drop as the front passes but it will really only bring us down a little cooler than we should be for this time of year. Temps will warm back up towards the end of the week. Right now it looks like it may be a week or more before the next weather system comes through although that is subject to change of course.

That is all I have this morning. I'll let you know if anything concerning pops up in the tropics. Have a great week.

Chris

Eta Now Headed Just North of Tampa...

November 11, 2020

First of all Happy Veterans Day! Second of all, what a difference a day makes, or day and a half. I just realized that I called the last email I sent on Monday night "Tuesday Night Update...," I'm not sure what that was about...I'll correct the blog, you all make pen and ink changes on your end...Also, nobody responded to tell me what they thought the spaghetti models looked like...Anyhow, Eta is now solidly headed just north of Tampa and I think we can feel good that this forecast won't change. Eta has regained hurricane strength but is expected to weaken some before landfall tomorrow.

Frankly I don't understand everything that caused so many changes in the forecast and models. I was really starting to think this was going to go to the west. Maybe this will turn into a case study so I can learn more. I think partly it was due to some better data we got yesterday from a hurricane hunter flying around the far outer edge of the storm sampling the large scale environment. I think it is also due in part to Eta being a little stronger than expected, a weaker storm would have headed more to the northwest. Below is an animation of the forecast cone changes since Friday the 6th. Once this is all over I'll make an animation of Eta's entire life in the cone through four landfalls.

Elsewhere in the tropics, Theta is doing its thing to the east. The red area in the Caribbean has been designated Invest 98L. Right now it is mainly considered to be a threat to Central America, and maybe quite a substantial one. In the long term we'll have to watch and see if it tries to come north.

That is it for today. We'll keep an eye on 98L, which will probably become Iota soon. Conditions are also generally favorable for even more development in the Caribbean so we will have to keep an eye out for that over the next few weeks.

Chris

Monday (not Tuesday...) Night Update On Eta

November 9, 2020

I wanted to send out a quick update on Eta tonight. The bad news is that I don't think we know yet what it is going to do. The good news is that I don't think it will be a very strong storm wherever and whenever it makes landfall. From the NHC: "There is lower than normal confidence in the latter portion of the track forecast given the large spread in the guidance." I don't think the NHC cone is correct in the long term. I don't so much think that it is wrong, as in the NHC is wrong, only that the NHC is intentionally slow to make forecast adjustments and I don't think we've seen the end of the changes to the models. For the record, my "guess" yesterday that the storm would hit the Big Bend looks to be fairly unlikely at this point. So for now no more guesses from me...

Here are some models to illustrate the continued uncertainty:

Spaghetti (I see a shrimp with long antennae attacking the Panhandle, what do you see?): 

ECMWF (these are split between tracks to the southwest and north or northeast with most dissipating over water):

GEFS (GFS ensembles, most tracks seem to curve off to the northwest with many dissipating also):

UK (most members take the storm southwest into Mexico):

Notice that virtually all the tracks in the last three images are blues and greens indicating a weak storm. There are a lot of different solutions here with little consensus. If I had to pick a trend from all of these it seems like the curve off to the northwest is favored a bit at the moment, but we'll see how long that lasts. The HWRF currently takes a very weak storm into Apalachicola with the previous two runs showing a weak landfall in Louisiana so not much consistency there either.

So it looks like we have more watching and waiting. In other news subtropical storm Theta has formed way out in the Atlantic. This is noteworthy because 2020 has officially set the record for the most storms of any Atlantic Hurricane season on record. The thinking is that we may add 1-3 more storms before it is all over with. Speaking of that, the NHC identified another area of interest in the Caribbean later during the day on Sunday. This was the new system I mentioned we need to keep an eye out for as we get closer to the weekend. The NHC currently has this area at a 50% chance of development over the next 5 days.

That's it for this evening. I really don't think Eta is much of a threat but rightfully so most of you don't trust a storm farther than you can throw it...so let's see what it does.

Chris

Update on Eta and Other Weather

November 8, 2020

Tropical Storm Eta is current located over central Cuba and is expected to make landfall in the Keys early Monday morning, possibly as a hurricane. After that Eta will move west into the Gulf and then start to drift around midweek as steering currents break down. This is depicted well in the forecast cone which shows a lot of uncertainty after day 3.

After Wednesday things are very uncertain although the general trend brings the storm back into Florida somewhere between Tampa and the Panhandle towards the end of the week or weekend. There is a lot of disagreement with the models so it's difficult to know what will happen. The GFS brings Eta almost to a landfall as a hurricane in Tampa on Friday before taking it back to the west and then back towards the Big Bend as weak tropical storm on Monday. The Euro brings a weak tropical storm into the Panhandle between Apalachicola and Destin on Saturday. The GFS ensembles have several members taking the storm towards the Tampa area but a lot of them in the current run actually take the storm back to the southwest where it dissipates over the Yucatan. The Euro ensembles are fairly well grouped taking the storm into Florida between Apalachicola and Tampa on Friday or Saturday. It is interesting that the operational Euro has consistently shown the storm coming into the Panhandle with the ensembles only showing a few members heading that way, most are farther east. Both the operational Euro and ensembles have been consistent for days, so that is something to consider. For what it's worth the UK also dissipates the storm over the Yucatan on Friday and the Canadian brings a really weak storm into the Big Bend, also on Friday.

The good news is that the intensity trend keeps Eta relatively weak. A hurricane impact on the Gulf Coast isn't impossible, but a tropical storms looks most likely at this time. The HWRF is a bit of an outlier here, it blows the storm up to category 3 strength and then takes a category 1 storm into the Big Bend on Thursday. Even though the HWRF has been a good model this year, this far out and in that much disagreement with the other models I am skeptical. It does give us an idea of what could be possible though. If I had to guess, I'd say Eta will make landfall somewhere between Apalachicola and the Big Bend as a tropical storm on Friday or Saturday. Even though as a whole models have been inconsistent and not in agreement, the most consistent trend brings a tropical storm into the Big Bend. A big caution is that all of this uncertainty kicks in right when we get to the 3-5 day range when forecasting becomes unreliable in all but the best conditions. The recent inconsistency with the GFS ensembles could be that it is picking up on a new steering pattern possibility back to the southwest. That will be something to watch for over the next 24 hours to see if that is a one run anomaly or the start of a trend, especially if the Euro starts to pick up on this.

Looking longer term, may we see a chance for another system to develop in the western Caribbean late next week into the weekend. Model signals aren't overwhelming, but there is enough there to suggest we need to watch for it.

Regarding non-tropical weather, it looks like a front will sweep through most of the Southeast on Wednesday and then stall on Thursday near the coast through most of the weekend. This stalled system is probably one reason the steering for Eta breaks down. We may see a little bit of cooler air with this front, more so for northern AL and TN, but for most of us it looks like our next chance for cool air will around the beginning of the week of the 16th.

That's it for today. Let's keep watching Eta, it may be closer to midweek before we get a good handle on how things will play out. The good news is that I don't think we're looking at a major impact, but there will likely be at least some impacts somewhere along the Gulf Coast.

Have a great Sunday and a good start to the week.

Chris

Quick Update on Eta - Spoiler: We're Still Waiting...

November 5, 2020

I've been waiting for better information before sending an update on Eta. We still don't know a whole lot but since it's getting near the end of the week I thought I should get something out since I said I would. That sounds a bit like the election, but I digress... The official forecast for Eta is below. You can see Eta will be with us for a while, maybe well into next week or even the weekend possibly. One reason I have been waiting is we really need the storm back over water for a day or two to get a better feel for what the mid to long term forecast will look like. You can see that there's a fair possibility that we'll have a storm in the Gulf early next week but that's not guaranteed. In the long term models are all over the place showing everything from a landfall anywhere from the Keys to Louisiana in the Gulf to a Florida east coast landfall with the storm then crossing back over into the Gulf. Some of the models have been downright entertaining. The good news is that there doesn't seem to be a strong consensus for a lot of intensification, but you know how this season has been going...

That's it for now, there should be some better info by Saturday I hope. Keep an eye out for Levi's videos if he posts one, they've done a really good job explaining what is going on.

Have a good end of the week and a great weekend.

Chris

Tropical Storm Eta Form in the Caribbean - Not a Short Term Threat to the US

November 1, 2020

Yesterday Invest 96L became TD 29 and then Tropical Storm Eta. This year now ties 2005 with the record for highest number of named storms in the Atlantic on record. You can see the official track for Eta below. Eta is no threat to the US, but we do need to watch the area where Eta makes landfall late this week for something new to develop.

Levi Cowan does an excellent job explaining the situation with Eta and what the models are showing. If you have 13 minutes I recommend you watch his video from last night here: https://www.youtube.com/watch?v=9tVcZGOkD70

If all you're concerned about is Eta you can forego reading the rest of this email. I spend the rest of it explaining what I was seeing yesterday, talking about the possibility for development late this week, and talking about models a bit.

Looking at this morning's model runs, it seems like the GFS really was the odd man out yesterday. The GFS now brings Eta into Central America on Monday and no longer shows it stalling and then coming north. What is interesting is that both the Euro and GFS ensembles as well as some of the spaghetti models still show tracks to the north as shown below.

Spaghetti:

Euro Ensembles:

GFS Ensembles:

So what are these tracks to the north? Some of them are forecasts for Eta, although likely erroneous, but most are showing something else. What Levi explained last night is that Eta is part of a larger broad circulation in the western Caribbean. These tracks back to the north are picking up on the idea that this broad circulation might spit out another storm and send it off to the north late this week. This new storm could be what is left over from Eta after landfall or something else, but either way there's a fairly strong hint that something may develop. Last night's run of the Euro shows this idea well. This was confusing me a bit yesterday and I thought it would be informative to show you a few models. The first animation below is the vorticity product at 850mb, which is the large scale spin in the atmosphere at about 5,000ft. It is my go-to product to look for tropical cyclone development. The large circular orange and red areas are storms. You can see Eta make landfall and then something else come north. Ensembles can be confusing to look at, after a time it is really hard to tell if you're tracking the same storm or something new. The second animation below is the "spaghettios" product from the Euro ensemble model, the EPS. It is showing the locations of low pressure systems from 51 different members. After showing Eta going ashore you can easily see how it quickly becomes difficult to track what is going on and it is impossible to tell if it brings what is left of Eta back north or something new. Either way it is still very informative and you can get an idea how well the operational Euro, the first animation, is doing if it is in fairly good agreement with the general trend you see in the ensembles. Ensembles also help you sniff out things that the operational models aren't showing. Many times this year both the GFS and Euro failed to show development but the majority of their ensembles did, especially with the GFS. This was telling us that we should not be trusting the operational models, especially when we had a robust tropical wave entering an area where conditions were ripe for development. Please, ignore anything out beyond 120 hours, models are fairly unreliable past 5 days for forecasting although you can use the longer term maps to get an idea of what may be possible.

Hopefully that long explanation was informative or at least interesting. I think we can feel good that Eta isn't going to come north in the short term but we need to watch and see what happens towards the end of the week regarding the possibility for new development.

Unless something changes significantly I'll probably wait until midweek to send out another update. Have a great Sunday.

Chris