Monday Night Update on Hurricane Ian

September 26, 2022

This will be a short update this evening. The 5 p.m. advisory on Hurricane Ian is shown below and as you can see the western FL Panhandle from Bay County west is almost certainly safe from any significant impacts. All the same, the expected impacts maps are shown as well.

There is some chance that we may see tropical storm force winds (>39mph) with locations farther east having a greater chance, but impacts will most likely be minimal. Probabilities with earliest and most likely arrival times are shown.

Right now no storm surge impact is expected for our area but you may notice tides are a little higher than normal.

Expected Storm Surge

Rainfall in our area is expected to be limited to just a few inches (we may actually get very little to none) and the flooding risk is low as well.

5-Day Rain Totals

Flash Flood Risk

That's it for this update, which will likely be my last one for Ian, which should be bring little to no impacts to our area.

As of now there's nothing else out in the tropics to be concerned about either.

Have a good week.

Chris

Tropical Storm Ian Sunday Morning Update

September 25, 2022

I've been waiting for Ian to decide what it's going to do before making a post. We're not quite there yet but I'll tell you what I know at this point.

The official forecast for Ian as of 11 a.m. EDT is shown below. After shifting west quite a bit yesterday due both to model shifts and shifts in the storm's position the track has been mostly stable overnight. For an excellent explanation of these things and why they matter watch Dr. Levi Cowan's (Tropical Tidbits) latest video. You can see the center of the forecast track takes the storm into the St. Marks area of Apalachee Bay early Friday as weakening category 1 or 2 storm but with quite a bit of spread in where it may ultimately end up (more on this below). Reading between the lines I think the most favored track is still east of our area but a track more to the west can't be ruled out. Ian is expected to become quite strong before landfall with the forecast calling for a category 4 storm with 140mph sustained winds in the Gulf three days from now. The presence of increasing wind shear from a trough (think front) pushing south is expected to weaken Ian as it approaches the coast. That being said, significant impacts are expected wherever Ian does make landfall.

Now let's talk about the forecast uncertainty. Really the best resource on this is the video I linked above, but I'll do my best to summarize. First it's important to understand that the cone of uncertainty shows "two-thirds of historical official forecast errors over a 5-year sample," source. Another way to look at that is one third of storms track outside of the cone. Also, note that the cone does not represent uncertainty in the models or that of a particular storm! For that we either need to look at the models or read the NHC's discussion. Here are some statements from the full advisory issued at 5 a.m. EDT: "While the models agree on the overall scenario, there are still significant differences regarding the exact track of the storm, especially after 72 hours. Even with the addition of.. [additional data]..., the spread in the guidance has not narrowed from before...With the cross-track spreading remaining between 200-220 n mi at days 4 and 5, it cannot be overstated that significant uncertainty remains in Ian's long-range prediction." And from the 11 a.m. EDT discussion: "there is still significant uncertainty in the long-range track forecast of Ian, and future adjustments to this portion of the forecast will likely be required." So while the track has stabilized some there is still quite a bit of uncertainty in the long term due to uncertainty on where the storm actually is (it's still not vertically stacked from the surface to the mid-levels of the atmosphere so the center is jumping around, although this is getting better) and future timing and strength of both Ian and an approaching trough that will be the main steering influence.

Getting into the models, the Euro and UK models have been consistent with a Florida west coast landfall. The GFS models started shifting west on Thursday with this continuing through yesterday afternoon when some of the hurricane spaghetti models started shifting west also.  While there is still a group of models to the west of the Euro and UK, some good news for us in the western Panhandle is that several models in this western group, including the GFS, have shifted back to the east a bit. This is a trend I've been looking for. Yesterday afternoon I was starting to have growing concerns that Ian may be coming our way but I wanted to watch and see if the western trend continued or not. Now that the shift has stopped and even moved back east a little I'm feeling better. Even so, it may be another day or so before the track is nailed down with more certainty. Shown below are the latest GEFS, EPS (Euro), UK, and other spaghetti models.

GEFS Ensemble (GFS)

Euro Ensemble

UK Ensemble

Other Hurricane Spaghetti Models

There's not much else that needs to be said at this point. It's a good time to think about any plans you'd need to make if a storm does come our way, get some supplies, and get some gas. We'll have a clearer picture in a day or so.

Enjoy your Sunday.

Chris

Tropical Development Possible in the Caribbean

September 19, 2022

Well that didn't take long... The National Hurricane Center is watching a tropical wave located east of the Windward Islands for development as it moves west this week. Currently they are indicating a 20% chance of development through 5 days. Computer models started picking up on this yesterday with consensus growing since then. The GFS is very quick to develop this wave with a bona fide storm forming before reaching the islands later this week while the Euro and Canadian models don't show development until it's in the Western Caribbean early to mid next week. With the three respective ensembles for these models in good agreement that this wave will develop as well I think there is a pretty good chance we'll see something come of this. It's really too early to speak of the storm's track but this could end up being a threat to the Gulf as it moves north out of the Caribbean with potential tracks ranging from the northern Gulf Coast to more to the east across Cuba and the Bahamas and also with a few tracks going towards the western Gulf. Once Fiona moves out of the picture a high pressure will develop in the Atlantic that will keep this wave/storm moving west or west-northwest through the weekend or longer. It looks like the timing of a series of troughs (think fronts) around the end of the month will largely determine the final track north. In the short term there's not a lot to inhibit strengthening once/if a storm forms but any troughs present near the point of landfall could impart wind shear that limits strengthening later or causes some weakening prior to landfall. Again it's still too early to be specific about all of this but that is the general idea how things may play out.

Tropical Wave of Interest Circled in Green

More to come on this later this week. It'll be the end of month or early October before this is a concern so we have plenty of time to watch it. That being said it may not be until early next week until we start having a good idea how this will ultimately evolve.

Have a good week.

Chris

Tropical Storm Fiona Likely not a Threat to the Gulf

September 16, 2022

A quick update on Fiona tonight but there's not much else to say that's not in the title. The latest NHC forecast is below and you can see the storm is likely to curve into the Atlantic around Monday and stay out of the Gulf of Mexico. There will be continued impacts to the northern Leeward Islands, Puerto Rico, Hispaniola, possibly the Bahamas, and then maybe Bermuda down the road. Impacts to the U.S. East Coast look pretty unlikely at this point but it's a bit too early to know for sure.

EPS, UKMET, GEFS, and CMC Super-Ensemble

http://arctic.som.ou.edu/tburg/products/realtime/tropical/

Hurricane Spaghetti Models

https://web.uwm.edu/hurricane-models/models/index.html

Looking at the rest of the tropics there's not much else to talk about. I've heard some chatter that activity may pick up later this month and into October but the way this season is going we'll just have to wait and see.

That's it for today on the tropics. I expect this will be my last post on Fiona. Here in the Southeast expect the weather to remain pretty nice through the week with maybe a chance of rain near the coast and expect the temps to go back up.

Have a good weekend.

Chris

Tropics Go Back To Being Quiet

September 11, 2022

Yesterday was the climatological peak of hurricane season and as you can see below the tropics are oddly quiet. The only area being watched by the NHC is a wave that is going to push off of Africa on Monday. It has a 20% chance of development over the next 5 days but I don't think we have to be concerned about it.

The only other thing I want to mention is the tropical wave I spoke about last time. The wave I'm watching is the one south of the big 'H" half way between Africa and the Lesser Antilles. Other than a few ensemble members, models aren't showing any outright development. However, it does look like it will hold together somewhat as it continues west. By the end of the week it will be approaching the Windward Islands and it is at this point that a few ensembles start to develop it. Wind shear conditions from the Windward Islands through to the eastern Gulf don't look the best but anytime there's a wave moving through this area this time of year I think it's worth watching. I think it's a low probability that this will develop but I want to continue to watch it for the next 10 days or so.

The first cold front of the season will push through tomorrow and leave behind some cooler and drier air. Folks along the coast will not notice too much (we'll get a few nights in the mid to upper 60's) but northern AL and TN will have two or three nights in the mid to upper 50's with day time highs still fairly warm for all. The weather north of the coast looks dry through at least the end of week but along the coast expect rain chances to return by Thursday. That being said I think the weekend will be fairly nice with only a 30-40% chance of rain.

That's it for today, the tropics remain oddly inactive given what the seasonal forecasts were predicting. As a homeowner along the coast I have no complaints but it's confusing when so many forecasts fall flat. The season isn't over by any stretch but we're definitely not going to have the above average season that was predicted.

Have a good week.

Chris

Tropical Weather Update - Lots of Activity but no Current Threats to the US

September 7, 2022

Activity in the tropics has picked up (finally?) but even so this will be a fairly short update. Looking at the 5 Day Outlook you can see there is quite a bit going on with two named storms and two other areas being watched. The good news is that these areas are not a threat to land with possibly one exception (and not counting Bermuda which Earl may impact). 

The one exception is the yellow 'x' on the African coast. This area is a tropical wave that is just emerging into the Atlantic. In about ten days time this wave will be approaching the Leeward Islands and then it will probably continue making its way across the northern Caribbean. The 06Z GFS run notwithstanding (which develops this too early in my opinion which causes it to recurve into the Atlantic) it looks like this wave will stay moist but in an otherwise somewhat hostile environment as it moves west. Ensemble models are split between developing it too early, which again I think is less likely, or not developing it at all so we'll have to watch how the trends evolve. So even though a forecast for a long term threat to the Caribbean or Gulf is not in the cards at this point, and would be unreliable if it was, a tropical wave moving into the Caribbean this time of year is something to watch especially if conditions become favorable two weeks from now. 

Along the northern Gulf a coastal low pressure may develop along a cold front that will push into the area later today and tonight. A few ensemble members from both the GFS and Euro hint at a chance for development but it looks like wind shear will be too strong for anything tropical to try and form. You may see some things about this on the internet but no development is expected. What you can expect is more rain along the coast (what else is new...) but the current forecast projects the highest amounts to the east in the Big Bend region. Looking through the weekend and into next week this pattern may stay in place with a series of coastal lows forming along frontal boundaries with continued rainy weather.

5 Day Rainfall

That's it for today. Nothing to be concerned about in the short term, but maybe something to watch down the road. Have a good week.

Chris