Monday, October 8, 2018

Hurricane warnings issued as Michael strengthens and aims for Florida

Hurricane Michael is strengthening as it enters the Gulf of Mexico and is aimed at Florida. The storm is expected to become a Category 3 hurricane by the time it reaches Florida’s Gulf Coast on Wednesday. It will probably be the area’s strongest hurricane in at least 13 years.
Florida’s Panhandle, from Pensacola to Apalachicola, and its Big Bend area are the zones of greatest concern. This area faces the possibility of coastal inundation from rising ocean waters, flooding rain and destructive winds starting Tuesday night and continuing through Wednesday.
“#Michael could be one of the worst hurricanes to ever strike the Florida Big Bend and Florida Panhandle region,” tweeted Rick Knabb, the Weather Channel’s hurricane expert. “We only have today and Tuesday to complete life-saving preparations.”
The National Hurricane Center warned of a “life-threatening storm surge,” which is the rise in ocean water above normally dry land. It could reach at least 8 to 12 feet in hardest-hit areas, inundating roads, homes and businesses. Mandatory evacuations were ordered in three Florida counties.
Serious hurricane effects will not be restricted to coastal areas and may extend farther inland, potentially affecting the Tallahassee area. Damaging winds also were predicted to reach southern Georgia and southeast Alabama.
Gov. Rick Scott (R) declared a state of emergency for 26 counties. “Families should take the opportunity TODAY to make sure they have three days of food and water, as well as all needed medications,” he tweeted. “EVERY FAMILY must be prepared. We can rebuild your home, but we cannot rebuild your life.”

Enhanced infrared satellite loop of Hurricane Michael about to enter the Gulf of Mexico. (weathernerds.org)
After making landfall on Wednesday, Michael’s effects are expected to surge northward. The Hurricane Center called for “life-threatening flash flooding” through Georgia and South Carolina, including some of the same areas flooded by Hurricane Florence.
While destructive hurricane-force winds are forecast to be confined mostly to Florida, damaging tropical-storm-force winds are predicted to affect a much larger area, potentially expanding north into the Carolinas.

Probability of tropical storm-force winds from Hurricane Michael. (National Hurricane Center)

The latest

As of 11 p.m. Eastern time, Michael’s peak winds were at hurricane strength, sustained at 90 mph, as it moved north at 12 mph. It was centered 450 miles south of Apalachicola.
The storm, the seventh Atlantic hurricane of 2018, began to form an eye on Monday as it strengthened. Traveling over very warm water, with light upper-level winds, it could rapidly intensify over the next 24 hours, the National Hurricane Center said.
At its current rate of speed, tropical-storm-force winds should reach the northern Gulf Coast as early as Tuesday evening, after which conditions will deteriorate. Landfall is projected Wednesday — although models differ on whether it will occur early or late in the day.
Hurricane warnings have been posted from the Alabama-Florida border to the Suwannee River, just northwest of Cedar Key on Florida’s west coast. Tropical storm warnings extend farther south, to Chassahowitzka, Fla., and to the west, along the Alabama coast. Tropical storm watches are in effect for the Mississippi coast and around the Tampa Bay area.
Storm-surge warnings are in effect from the Okaloosa/Walton County line in Florida to the Anclote River around Tarpon Springs. The Tampa Bay area is under a storm-surge watch.

Storm effects

Florida Governor declares state of emergency for 26 counties
Florida Gov. Rick Scott warned residents that tropical storm Michael could become a Category 3 hurricane by the time it makes landfall on Florida's gulf coast. 
Storm surge
Michael is projected to strike an area that is exceptionally prone to storm surge because of the adjacent shallow shelf water and the concave shape of the coast. Like a bulldozer, the storm will be able push a vast amount of ocean water inland, potentially inundating homes, roads and businesses on the coast.
Areas to the east of where the storm center tracks will experience the greatest storm surge, and flooding will be worst around the high tides.
Storm surges just east of where the center makes landfall could reach 8 to 12 feet if the storm comes ashore around high tide. Here are specific initial storm-surge projections from the Hurricane Center:
  • Indian Pass to Crystal River: 8-12 feet.
  • Cedar Key to Crystal River: 6-8 feet.
  • Okaloosa/Walton County line to Indian Pass: 5-8 feet.
  • Crystal River to Anclote River: 4-6 feet.
  • Anclote River to Anna Maria Island, including Tampa Bay: 2-4 feet.
  • Alabama/Florida border to Okaloosa/Walton County line: 2-4 feet.

Areas under storm surge-watch and warning. (National Hurricane Center)
Rainfall
The National Hurricane Center projects widespread rainfall amounts of four to eight inches, from the Florida Panhandle and Big Bend areas north into Georgia and South Carolina, and isolated amounts of up to a foot. “This rainfall could lead to life-threatening flash floods,” it said.
Over the Florida Peninsula and Florida Keys, two to four inches are predicted, with isolated amounts to six inches.

Hurricane Michael rainfall forecast. (National Hurricane Center)
Heavy rain could arrive in Florida on Tuesday night and in south Alabama and south Georgia early Wednesday. By Wednesday night and into Thursday, heavy rain will rapidly streak through Georgia and into the Carolinas.
Flooding rainfall is likely to affect some of the areas recovering from Hurricane Florence.
The rain is expected to reach the Mid-Atlantic, including North Carolina, Virginia, Maryland and Washington late Wednesday night into Thursday before rapidly exiting by Friday. Depending on the track of Michael’s remnants, southern New England could also see a period of heavy rain late Thursday.
The potential rainfall in the Mid-Atlantic and New England ranges from 2 to 4 inches, with higher amounts locally. Because these areas have seen heavy rain in recent weeks, flooding may become a concern here as well.
Wind
Michael’s maximum sustained winds are forecast to be around 120 mph when it strikes the coast. Winds this strong will be confined to the ring around its calm eye, known as the eyewall, and “devastating” wind damage could occur in this narrow zone.
"Well-built framed homes may incur major damage or removal of roof decking and gable ends,” the National Hurricane Center said. “Many trees will be snapped or uprooted, blocking numerous roads. Electricity and water will be unavailable for several days to weeks after the storm passes.”

Probability of hurricane-force winds. (National Hurricane Center)
After the storm strikes land, this eyewall will quickly collapse, and winds will weaken.
While hurricane-force winds of over 74 mph will be confined to a relatively small area, tropical-storm winds of 39 to 73 mph will occur over a much larger zone and could result in minor structural damage and many downed trees and power outages.
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Elsewhere in the tropical Atlantic

Tropical Storm Leslie — which formed Sept. 23 — is still active and probably will be through the weekend. It is forecast to become a hurricane, again, as it heads toward the Azores by the end of the week. And despite being around for 16 days, it is presently centered just 115 miles from where it was when it formed.

Leslie's past track dating from Sept. 23, with the five-day forecast track and cone of uncertainty. (Brian McNoldy/tropicalatlantic.com/NOAA/NHC)
Finally, a potent weather disturbance that recently left the coast of Africa is located near the Cabo Verde Islands and has a shot at becoming at least a tropical depression this week, if not a tropical storm, before conditions become more hostile by the weekend. The National Hurricane Center is giving it a 60 percent chance of reaching tropical depression or storm status this week, but no models suggest this will become a threat to land. The next name on the list is Nadine.
Correction: A previous version of this article erroneously stated that the last major hurricane, Category 3 or higher, to strike the Florida Panhandle was Opal in 1995. It was actually Hurricane Dennis in 2005.


Visible satellite image over the far eastern tropical Atlantic. (EUMETSAT)
https://www.washingtonpost.com/weather/2018/10/08/michael-strengthens-hurricane-is-forecast-make-landfall-florida-dangerous-category-midweek/?utm_term=.b05a4a79f2e6

-Posted by: Ciela Marie Acala

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