The main purpose of this ongoing blog will be to track planetary extreme, or record temperatures related to climate change. Any reports I see of ETs will be listed below the main topic of the day. I’ll refer to extreme or record temperatures as ETs (not extraterrestrials).😉
Main Topic: Tracking Hurricane Ian Day2
Dear Diary. All eyes of the weather and climate world are on Hurricane Ian, so we will focus on that for this and the next few posts. Here are a couple of my observations, using the latest model data from this morning:
The consensus of model data appears to shift the landfall of Ian just south of Tampa for Thursday morning:
Here is my friend Matthew Cappucci’s latest writeup on Ian from the Washington Post:
Ian forecast: Major hurricane landfall expected along Florida’s west coast
Landfall is predicted late Wednesday into early Thursday; the storm threatens to bring a ‘life-threatening storm surge,’ destructive winds, flooding rains and tornadoes
Updated September 27, 2022 at 1:10 p.m. EDT|Published September 27, 2022 at 10:25 a.m. EDT
Hurricane Ian as viewed from NOAA’s GOES East weather satellite on Tuesday morning. (Tropical Tidbits)
Hurricane conditions are forecast to be upon Florida’s Gulf Coast by early Wednesday morning, so authorities were urging residents to evacuate to higher ground and otherwise make sure they are prepared for the storm Tuesday.
“You’ve got today,” said Jamie Rhome, the National Hurricane Center’s acting director. “Not to put too fine a point on it, but you’ve got today to make your final preparations.”
After that, conditions were expected to rapidly devolve, with threats of hurricane-force winds, flooding rain and damaging storm surge, a rise in ocean water over normally dry land.
A storm surge warning covers Tampa Bay and a stretch of the coast from Tarpon Springs in the north and Flamingo, on Florida’s southern tip. The hurricane center warns “there is a danger of life-threatening inundation … from rising water moving inland from the coastline,” with the highest risk between Fort Myers and Tampa Bay, where the surge could be as high as 12 feet.
In addition to destructive winds potentially topping 100 mph, the National Hurricane Center is also warning that “widespread considerable flash and urban flooding are expected mid-to-late week across central and northern Florida.” Some weather models suggest rainfall of up to two feet is possible in central west Florida.
Even far removed from the storm, meanwhile, tornadoes could accompany Ian’s spiral rain bands. Several tornado warnings were issued overnight for the Florida Keys, and conditions favorable for tornadoes will overspread much of the Peninsula later Tuesday.
Here is what to expect from each of the storm’s main threats, and when:
Storm at a glance as of 11 a.m. Tuesday
- Location: 305 miles south-southwest of Sarasota, Fla.
- Movement: Due north at 10 mph
- Maximum sustained winds in eyewall: 115 mph
- Category: 3
- Air pressure: 28.44 inches or 963 millibars
Ian made landfall in southwestern Cuba early Tuesday as a major hurricane. A mature eye has since formed on satellite. Overnight reconnaissance flights inside Ian found a roughly 11- or 12-degree spike in air temperature inside the eye. That’s a sign of sinking air, which heats up and dries out. The more air that rises in the eyewall of a storm, the more that sinks in the eye, and the hotter and clearer the eye gets. That’s an indicator of a powerful hurricane.
The storm’s peak winds modestly dropped — from 125 to 115 mph — as it crossed Cuba, but they are forecast to increase to 130 mph by Tuesday night as the storm moves back over warm water.
Weather models late Monday converged in their simulations of Ian to make landfall somewhere between Tampa Bay and Cape Coral in the Wednesday evening to Thursday morning time frame. Because Ian will be turning eastward and moving ashore sooner than if it continued northward, there will be less time for dry air from the north to infiltrate the storm and weaken it substantially before it comes ashore.
The National Hurricane Center is predicting a Category 3 landfall around 8 p.m. Wednesday on the south side of Tampa Bay, near Bradenton, Fla.
Predicting the exact strength of Ian is a challenge. On one hand, Ian will be moving over very warm sea-surface temperatures supportive of it maintaining its strength or even subtly intensifying. Conversely, an uptick in disruptive wind shear, or changing winds with height, combined with an influx of dry air from the north will seek to weaken Ian. It appears the two will counteract to yield a net gradual weakening as Ian makes landfall.
Still, that will leave Ian as an intense hurricane until landfall, at which point a more hasty decrease in strength is predicted, as it becomes removed from the warm ocean, or its fuel. It is worth remembering that a storm’s strength or category has no bearing on how much freshwater flooding it can produce, which has become the leading cause of casualties in tropical cyclones in recent years.
The storm will be slowing down as it moves ashore, prolonging impacts to western and central parts of the Florida Peninsula. By late Thursday, Ian will have begun curving northward to the northwest of Orlando, bringing tropical-storm impacts to north Florida. Ian is then expected to weaken into a depression, or remnant tropical swirl of low pressure, as it cruises through Georgia and South Carolina into the start of the weekend. Heavy downpours, breezy winds and a few tornadoes would be possible.
Storm surge forecast from the National Hurricane Center.
The National Hurricane Center is predicting that a 5- to 8-foot storm surge would be a reasonable worst-case scenario expectation in Tampa Bay based on the current track forecast. That’s a slight decrease from the previous 5- to 10-foot surge forecast that was predicated on the storm’s eye passing just to its north. Since then, track projections have shifted slightly to the south, somewhat decreasing the surge risk around Tampa but increasing it between Sarasota and Cape Coral, where it could reach 8 to 12 feet.
As hurricanes swirl counterclockwise, onshore winds and the greatest surge potential is found south of the center of circulation. To the north, winds will blow out of the east, off the land — thus reducing the surge.
A slight northward shift in Ian’s track would greatly increase the surge risk in Tampa Bay.
That’s why storm surge warnings are in effect for Tampa Bay and areas to the south, where confidence is highest of dangerous impacts. To the north, only storm-surge watches are up for now, since the potential exists for offshore winds.
Storm surge is an increase in water levels above ordinarily dry ground. Florida’s offshore bathymetry, or the shape of the sea floor, is extremely conducive to serious flood events. That’s because of the long, shallow and gently-sloping continental shelf in the eastern Gulf of Mexico.
Imagine pushing a grocery cart up a long, gradually sloping ramp — it would be effortless in comparison to pushing it up a short, stubby or nearly vertical ramp. That’s the premise here; it’s wayeasier for strong winds to blow an enormous volume of water ashore.
Rain and freshwater flooding
Forecast rainfall from Hurricane Ian. (NOAA/WPC)
The heaviest rain will come down near and to the north of Ian’s center. The storm will ingest dry air from the northwest as it makes landfall, which will swirl into the storm and begin slowly eroding its southern flank. That will cut back on rainfall totals south of the center, though a widespread 3 to 7 inches is still likely.
To the north, however, rainfall rates of 2 to 3 inches per hour are possible near and just north of Ian’s eye, with totals in the 12- to 16-inch range widespread and few locales seeing closer to two feet. The storm’s slow forward speed will increase the risk of serious flooding.
It’s important to remember that, in moisture-loaded environments like this, heavy rain can fall far from the center. That means places between Orlando and Jacksonville even on the eastern side of the state could see a foot of rain.
The weather has been anomalously wet across Florida as of late, meaning the ground is already saturated and will have a difficult time absorbing excess runoff.
Anticipated storm surge, meanwhile, will back up rivers, making it more challenging for excessive rainfall to drain to the sea. The two will conspire to further exacerbate freshwater-flooding impacts. The Weather Prediction Center notes that there is a level 3 out of 4 “moderate risk” of flash flooding and excessive rainfall.
Friday and into the weekend, heavy rain will spread further north into Florida and then over the Southeast and Mid-Atlantic.
“Considerable flooding is expected across Central Florida into southern Georgia and coastal South Carolina, with significant, prolonged river flooding expected across central to northern Florida,” the Hurricane Center wrote.
The storm’s remnant rainfall could persist over the Mid-Atlantic into early next week.
Winds will be strongest near the coastline as the storm center comes ashore — the zone from roughly Cape Coral to Tampa is most at risk.
The strongest winds will be found within the eyewall, or a semi-unbroken band of intense convection — downpours and thunderstorms — that encircle the eye. The ring of extreme winds may gust to near 100 to 120 mph at the shoreline, and 80 to 100 mph within a few miles of the coast.
Farther inland, winds gusting 65 to 90 mph will be common near the storm’s center, or within 50 miles of the coast. Farther east, winds will be mainly tropical storm force in nature.
Residents in the path of the storm should ensure their place of shelter is not at risk of being affected by falling trees.
The combination of saturated ground and high winds will greatly increase the risk of tree falls and power outages.
Landfalling tropical systems often produce tornadoes in their right front quadrant, or ahead of and to the right of the center. That’s because onshore winds slow as they encounter friction from the rough land surface, while upper-level winds roar on unimpeded. That results in wind shear, or a change in wind speed and/or direction with height.
That means any towering clouds that extend vertically through multiple layers of atmosphere, like cells within Ian’s spiral rain bands, will be subject to a twisting force. That means a few quick-hitting tornadoes, probably wrapped in rain and impossible to see given low cloud bases, could form any time throughout the next several days. A tornado watch is already in effect Tuesday until 5 p.m. for parts of South Florida as some of the storm’s initial rain bands cycle in.
Warnings for waterspouts and a few tornadoes were issued across the Florida Keys on Monday night, and the Storm Prediction Center has drawn level 2 out of 5 “slight” risks of tornadoes across most of southern and central Florida in their forecasts over the next several days.
Scott Dance contributed to this report.
The Atlantic hurricane season
The latest: The 2022 season started out slow, but has rapidly intensified this fall with conditions prime for storms. Fiona brought severe flooding to Puerto Rico before making landfall in Canada, and now we’re tracking Hurricane Ian as it heads for Florida. For the seventh year in a row, hurricane officials expect an above-average season of hurricane activity.
Tips for preparing: We rounded up seven safety tips to help you get ready for hurricanes. Here’s some other guidance about keeping your phone charged and useful in dangerous weather, and what to know about flood insurance.
Understanding climate change: It’s not just you — hurricanes and tropical storms have hit the U.S. more frequently in recent years. And last summer alone, nearly 1 in 3 Americans experienced a weather disaster. Read more about how climate change is fueling severe weather events.
Here is more news and notes on Hurricane Ian (latest news will be posted at the top of this list, which I will frequently update as Tuesday rolls along):
Here are some “ET’s” recorded from around the planet the last couple of days, their consequences, and some extreme temperature outlooks:
Here is more climate and weather news from Tuesday:
(As usual, this will be a fluid post in which more information gets added during the day as it crosses my radar, crediting all who have put it on-line. Items will be archived on this site for posterity. In most instances click on the pictures of each tweet to see each article. The most noteworthy items will be listed first.)
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Guy Walton “The Climate Guy”