Snow day

Or, if you prefer, in the words of the 6 year old hodo-son, an "underwear day". Since the schools and many businesses are closed today, there isn't much to do except watch the storm and catch up on sleep.

Ernesto made landfall in south Florida in extreme southwestern Miami-Dade county overnight. Nearly zero strengthening occurred during the day yesterday when Ernesto moved from Cuba toward south Florida. This resulted in a weaker than forecast storm at landfall, and a weaker storm when he arrives here in Melbourne later today. Nothing wrong with that.

At 8 AM, Ernesto was found 50 miles ESE of Naples. Maximum sustained winds are now down to 40 MPH. Central pressure is about 1001 MB. Ernesto may be downgraded to a tropical depression prior to exiting the state somewhere between Daytona and Melbourne overnight Thursday. Strengthening back into a hurricane prior to landfall in the Carolinas Thursday evening is possible.

Looking outside right now, it appears to be a nice but overcast day right now. I've collected about an inch of rain since midnight; we'll probably see 3-6 inches before this is over. The worst of the storm won't be here until after lunch time, ending around midnight tonight. Expected winds are in the 25-35 MPH sustained, with gusts to 50 MPH.

Shields up?

Ernesto finally emerged from the Cuban landmass this morning, after spending not quite 24 hours over land. The combination of land and an upper-level low spinning to the northwest of Ernesto has weakened the storm to a 45 MPH tropical storm this morning. He has moved a little further west than anticipated by nearly a full degree of longitude (about 60 miles), which has implications for the track and strength forecasts. He is moving to the northwest at 14 MPH; central pressure is 1005 mb.

The movement to the west means both good and bad news for us. First the bad; it has shifted the forecast track back to our west. Ernesto is now expected to make landfall in the upper Keys early Wednesday morning and exit the peninsula somewhere between Melbourne and Daytona early Thursday morning. The models are again in excellent agreement on this scenario. Nearly none of the models take the storm to our east, in fact, more of the model tracks are west of the official forecast than east of the forecast. This will put Melbourne on the eastern (stronger) side of the circulation, so the tornadic threat will be high Tuesday night through Wednesday night.

The good news (yes, there can be good news in all of this): The circulation, as previously mentioned, spent more time over Cuba, and as a result is a little weaker and less organized. Additionally, as one progresses west along the northern Cuban coast, the distance to Florida decreases. Implication here is that the storm will (hopefully) spend less time over the high octane water in the Florida Straits. Ernesto has about 18-24 hours prior to landfall in the Keys, and is not expected to become a hurricane prior to landfall. This means a weaker storm for us, which is always good.

Weather conditions will begin to deteriorate today. We are under a tropical storm warning and a hurricane watch at of 5 AM this morning. On the current forecast track, we will have tropical storm force winds, with gusts to hurricane strength. Rainfall amounts are estimated to be in the 5-10 inch range before all is said and done; pumping down the pool a little bit might not be a bad idea today. Storm surge is not expected to be a big problem in this part of the state.

So, do you board up the abode today? I suppose it depends on your personal situation. For example, I probably would not wait in line at Home Depot for plywood for this one. If you don't have shutters, today is not the day to get them. Maybe this weekend, but not today.

If you've got shutters already made and ready to go, them you might want to consider putting them up, especially if you have certain parts of your home (e.g., big doors) that are a little more vulnerable to an east wind. The hodo-hut has a couple of those, so those will certainly go up today.

It's not clear to me what will be open tomorrow (schools, businesses, etc.). The usual threshold is whether or not the causeways can stay open, which (I think) the wind threshold is 40 MPH. Assuming that is the threshold, it seems to me we should exceed that, so I'd be surprised if those things remained open tomorrow. A decision on that should come later today.

Ernesto coming to visit

First off, apologies to any of you who happened to try and access this blog yesterday. Somehow, the blogger software deleted half of my blog template. Without a template, there's no blog to see. Yes, I realize this is a 21st century version of "the dog ate my homework", but it's all I've got. I've had to reconstruct the template from scratch; please leave me a comment if I haven't reconstructed a link you use/need.

A lot has happened since my last post. The forecast landfall position has shifted east from Mobile to just south and west of Miami. The storm strengthened into a hurricane Sunday morning, but then encountered the rugged terrain of Haiti, and weakened back down to a tropical storm. Ernesto is currently a 50 MPH tropical storm, moving to the NW at 12 MPH with a central pressure of 1002 mb. Landfall near Guantanamo should occur later this morning.

The forecast track drawn by the Hurricane Center this morning has Ernesto moving due north through Florida from southwest of Miami and exiting north of Daytona. I suspect it was a fairly easy track call for them; the computer models were in excellent agreement overnight on this forecast track. This resulted from the extra aircraft data taken last night to measure the winds and pressures of the steering features around Ernesto. Something we watch is the trend in the track forecast. In this case, the trend (since last Friday) has been to move the track further to the east with each forecast package. One can hope the trend will continue to push the track east and off of our coast, placing us on the (theoretically) weaker western edge. This is a possibility, but I wouldn't necessarily plan for it.

The amount of time Ernesto spends along Cuba is the thing to watch today. Of course, the longer he spends on land, the weaker the storm will become. The Cuban terrain is not as rugged as that found in Haiti, so the weakening shouldn't be as dramatic as yesterday. Ernesto is forecast to spend 12-24 hours over Cuba and emerge over the rather warm water there at about 78 degrees west longitude. A little east or west of this spot has implications for the location of landfall in Florida. Then, the longer he spends over these warm waters will determine how strong he'll get before landfall; currently he's forecast to spend 24 hours over warm water and make it back to Cat 1 prior to landfall. Other than land interactions, there are no other apparent inhibiting factors to prevent strengthening.

On this track, Melbourne will experience winds in the 50-60 MPH range during the day on Wednesday. Biggest threat will be the possibility of tornadoes occurring on the eastern edge of the eye, which is forecast to pass just to our west (weather radios are handy in this case). I suspect the causeways and schools will be closed on Wednesday, but these types of decisions won't be made until the Hurricane Center raises some sort of watch or warning for our area; as of 5 AM this morning, they had not yet done so, though it would seem they would need to do so by 5 PM this evening.

Today would be a good day to review that list of storm items you're supposed to have and replenish as needed.

Buy Gas Today

Tropical Storm Ernesto formed yesterday in the eastern Caribbean. Currently, Ernesto is a 45 MPH tropical storm, moving toward the WNW at 16 MPH. Ernesto has battled against upper-level shearing winds most of the last two days. There was even a period of time yesterday when I wondered if the storm would survive, but survive it has. The storm looks much more impressive on satellite this morning compared to yesterday morning. The shear is expected to weaken as we move forward from here which, unfortunately, means Ernesto should survive and, based on it's location, will have to hit land somewhere.

That "somewhere" is where all the fun begins. The storm track for the next three days is fairly straight forward: high pressure is found north of Ernesto, such that he should move on a NW heading and skirt Jamaica and western Cuba. After that, it will enter the Gulf of Mexico, and that's when the thinking diverges somewhat. Some of the global weather models develop a weakness in that high pressure ridge and consequently turn Ernesto north, resulting in a landfall location along the central/eastern Gulf coast. Other models do not develop this weakness, moving the landfall location toward the western Gulf coast. I think right now, we're looking at a Houston to Mobile landfall around next Friday or Saturday. Notice that timeframe is a week away, meaning there's an awful lot that can happen prior to landfall. Peninsular Florida (where I live) would appear to be safe from this one, but the Panhandle is not as safe.

Additionally (if somehow you haven't heard yet) Tuesday is the one year anniversary of Katrina's landfall in New Orleans. There is a decent chance Ernesto might be there next week.

The intensity forecast, usually the hard part, is relatively straightforward in this case. Ernesto is still battling shear and although the shear is decreasing, the sea surface temps (SST's) are not super warm in the central and eastern Caribbean. As such, gradual strengthening is expected over the next three days. The really warm SST's (over a deep layer of the ocean) are found from Jamaica into the Gulf. These SST's are still not as warm as last year, however, they are warm enough to develop the storm into a hurricane, and possibly a major hurricane as some models are forecasting.

With the possibility of another major hurricane in the Gulf of Mexico next week, it seems reasonable and prudent to procure some gasoline today and tomorrow before things get, well, interesting.

Early morning visible image...

...shows the shearing.

Sheared

Overnight, Chris became rather disorganized.



The image above is from about 5 AM ET this morning. The image shows the convection (thunderstorms) near and to the west of Puerto Rico. The swirl of clouds due north of Puerto Rico is the low level center of Chris. Essentially, shear from the north has decoupled the convection from the low level center. If one were to loop these images in time, one would note that the low level center is moving toward the west-northwest, while the convection is moving toward the southwest. Central pressure has risen to 1010 mb, and maximum winds are set at 45 MPH. There is currently a plane in the system.

Tropical systems decouple all the time; most recent example is Hurcn Jeanne in 2004. I distinctly recall the low-level center of that system moving to the west while the convection stayed to the east. Unfortunately, that system was able to recover and eventually make landfall on the Florida east coast. Not saying Chris is going to hit Florida; what I am saying is that Chris isn't necessarily dead yet.

So, what's next for Chris? No one is really quite sure what will happen next. Options are for the low-level center to fire up some thunderstorms, or for the cluster of thunderstorms to generate a low-level center. My guess would be for the latter to occur. I think the low-level center is in a poor environment (dry air, shear) to initiate very much convection. The cluster of thunderstorms is in a slightly better environment (not as dry, but still sheared). Currently, it would appear more likely that Chris would weaken (and possibly dissipate) than strengthen.

Models in this case are again less useful than usual. It took about 2-3 days for the global models to finally figure out where Chris was, and then Chris went ahead and had it's convection sheared off. A small subset of all the hurricane models have been consistently forecasting dissipation; these models continue to produce this forecast, which doesn't seem as far-fetched as it did earlier in the week. The NHC forecast track has Chris spending most of Sunday over central and western Cuba before emerging into the Gulf. If (big if) Chris makes it into the Gulf, it still poses a threat to (most likely) the southern Texas or Mexican coastlines.

The plane found 60 MPH!

Well, I did say we're not very good at this intensity forecast thing, didn't I?



Chris obviously got it's act together today. At 8 PM, Chris was packing maximum sustained winds of 60 MPH. The storm is moving toward the NW at 13 MPH. Chris is a small storm; tropical storm force winds only extend 25 miles from the center. Storm outflow (important for maintaining and increasing strength) is good from between north to southwest of the center (or, for those of you still with a clock face on your wrist, from noon to 7 o'clock). Dry air, and some shear are still present to the northwest of the storm.

Decreasing shear is most likely responsible for the intensity increase today. Some further intensification is possible. However, as I posted this morning, the oceanic heat content is not very great in this part of the Atlantic and is certainly not sufficient to support a major hurricane east of Florida. If Chris makes it into the Gulf of Mexico, then the heat content there, while still lower than last year, is sufficient to support a potentially dangerous system.

So, where is Chris going? Our global model friends have not yet settled on a reasonable solution (or even a series of possible soutions that can be debated). Many of them still disipate Chris after 72 hours. The Bermuda high is forecast to build in from the north and east, deflecting Chris left of its current heading after about 3 days. The current NHC forecast track reflects this, and seems reasonable, passing Chris closer to Cuba than Key West. It is possible Chris could interact with the rugged land mass of Hispanola, which would disrupt the circulation and possible throw all the previous forecasts into doubt.

New month, new tropical storm

Many have wondered why this tropical season has been so quiet. Actually, it has been rather normal, we're simply remembering last year, which (all together now) was the most active Atlantic season in written history. Chris is the 3rd named storm this year; by this time last year we had 7 named storms, 3 of those became hurricanes, and 2 of those became major hurricanes. Compare to the long-term (1944-1996) average of 1, 0, and 0 respectively, indicates last year was, well, abnormal, and that this year is slightly ahead of normal.

On to Chris. Chris became the third tropical system this morning. He is located a couple hundred miles east of Antigua, and is a minimal (35 mph) tropical storm. Chris is moving toward the west-northwest at 9 mph. Tropical storm warnings have been issued for most of the Leeward Islands, and tropical storm watches are up for Puerto Rico, and the Virgin Islands. Chris is expected to pass north of the islands over the next couple of days. Strong intensification over the next two days is not anticipated (but remember, we're not too good at that yet).

The forecast is problematic, primarilly because our forecast models haven't correctly located the storm yet. Global forecast models typically take a few runs to figure out/lock onto where a new tropical cyclone is. Additionally, NHC will most likely fly a plane into Chris today, collecting more data to be loaded into the models. In other words, today's simulations will tend to be less accurate than those from tomorrow. This morning, many of the global models dissipate Chris in about three days, and take it south into the rugged terrain of Hispanola. Tomorrow's models might have a completely different story.

The forecast is also complicated by the other flows in the region. Below is a water vapor satellite image from around 6 AM ET this morning. The colors here represent the amount of water vapor in the atmosphere in the roughly 5-7 km altitude range. The color bar on the bottom right indicates the amount of vapor, ranging from brown (dry) to blue (wet). If you loop these images following the link on the right (dial-up unfriendly) you can get a sense of the flow patterns.



First thing of interest is that there's an awful lot of dry air surrounding Chris. This is not an environment conducive for major strengthening. Second is the presence of an upper-level low pressure system centered east of the Bahamas, extending south to Hispanola. The location of this low relative to Chris will also determine the forecast.

Another factor favoring minimal intensification is the oceanic heat potential, illustrated in the image below. Long story short, tropical storms need warm water, and this chart indicates where the warm water is. The light blues indicate where enough warm water exists to support a minimal tropical storm or a Cat 1 hurricane, while the reds indicate where major hurricanes could be supported. Chris is currently located in the light blue area, implying there is enough heat in the ocean to support no greater than a minimal hurricane.



One factor in favor of strengthening is that the wind shear near Chris has been decreasing over the last day or so. The global models forecast this shear to continue to decrease over the next couple of days. Extra points to those of you who have noted that these are the same global models that aren't accurately modeling Chris just yet.

The Hurricane center has not bought off on the weakening trend from the global models. The current track keeps the storm south of the Bahamas, but north of the Greater Antilles. The storm is forecast to be a strong tropical storm (about 60 mph) covering a fairly small area. It is too soon to determine if it will impact Melbourne or not, but it is something that bears watching.