Hurricane Irma

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The problem is intensity forecasting is even more difficult than track forecasting when it comes to tropical cyclones. They don't know for sure it will weaken as much as forecast.

Some slight weakening is expected currently as the outer reaches of the storm are being disrupted by mountainous terrain of Hispaniola. The trouble is re-strengthening is still possible if the storm stays clear of Cuba. South Florida is flat and mostly covered with swamp. The landmass alone is unlikely to cause significant weakening. What could cause weakening is an increase in the environmental wind shear from the stalled out frontal boundary to its north. Unfortunately storms with a very large eye and "annular" characteristics can be unexpectedly resilient to shear. Also, conditions are only expected to become less favorable at the very last moment as the storm hooks north.

With all that said, there is no guarantee this storm won't effect the US with Category 5 strength winds. 185 mph is unlikely, but low end category 5 or high end category 4 landfall cannot be ruled out.

Let's not forget about Sandy: Minimal hurricane, $70 billion in damage. It was a considerable hurricane previously, but it made landfall as a minimal hurricane/extratropical storm hybrid.

Irma, as stated previously, might be headed for the populous Miami area. They are already talking about it exceeding Katrina/Harvey in total damage. Who knows what's going to happen. But the potential is there.

Irma must be taken seriously at this point.

SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...20.4N 69.7W
ABOUT 75 MI...125 KM ENE OF PUERTO PLATA DOMINICAN REPUBLIC
ABOUT 120 MI...190 KM SE OF GRAND TURK ISLAND
MAXIMUM SUSTAINED WINDS...175 MPH...280 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...921 MB...27.20 INCHES

The eye on satellite continues to be quite distinct, and data from
an Air Force reconnaissance plane indicate that the initial
intensity is 150 kt. The central pressure remains near 921 mb.

The environment along the future track of Irma is favorable for the
hurricane to maintain most of its current intensity, although some
fluctuations are likely due to eyewall replacement cycles which
are difficult to predict. There are no obvious reasons why Irma
will not remain a powerful hurricane for the next 3 days while
approaching Florida. Thereafter, an increase in the wind shear could
lead to gradual weakening, but Irma is expected to remain a
major hurricane until landfall occurs.

The best estimate of the initial motion is toward the west-northwest
or 290 degrees at 14 kt. Irma is being steered by the flow around
the south side of the subtropical ridge, but in 2 to 3 days, the
hurricane will be located on the southwestern edge of the
aforementioned ridge, and a turn to the northwest and north-
northwest should then begin. There has been no change in the
guidance which is still quite clustered and brings the core
of Irma very near the southeast Florida coast in about 3 days.
The NHC forecast, which is similar to the previous one, is very
close to the multi-model consensus and the HFIP corrected consensus
HCCA. The later has been performing very well during Irma.


KEY MESSAGES:

1. Irma is a potentially catastrophic category 5 hurricane and will
continue to bring life-threatening wind, storm surge, and rainfall
hazards to the northern coast of Hispaniola today. These hazards
will spread across the Turks and Caicos tonight and the Bahamas
tonight through Saturday.

2. A hurricane watch is in effect for much of Cuba. Irma is likely
to bring dangerous wind, storm surge, and rainfall to portions of
these areas on Friday and Saturday.

3. The threat of dangerous major hurricane impacts in Florida
continues to increase. A hurricane watch has been issued for south
Florida, the Florida Keys, Lake Okeechobee, and Florida Bay. This
watch will likely be expanded northward later today. Residents in
these areas should heed any advice given by local officials.

4. A storm surge watch has also been issued for portions of south
Florida and the Florida Keys. This means there is the possibility of
life-threatening inundation from rising water moving inland from the
coastline during the next 48 hours in these areas. The Potential
Storm Surge Flooding Map depicts a reasonable worst-case scenario -
the amount of inundation that has a 10 percent chance of being
exceeded. Because the Flooding Map is based on inputs that extend
through 72 hours, it best represents the flooding potential in the
watch area.

5. The chance of direct impacts is increasing in portions of
Georgia, South Carolina, and North Carolina, but it is too early to
specify the magnitude and location of the impacts.

FORECAST POSITIONS AND MAX WINDS

INIT 07/1500Z 20.4N 69.7W 150 KT 175 MPH
12H 08/0000Z 21.1N 71.7W 145 KT 165 MPH
24H 08/1200Z 21.9N 74.2W 140 KT 160 MPH
36H 09/0000Z 22.5N 76.5W 135 KT 155 MPH
48H 09/1200Z 23.1N 78.4W 135 KT 155 MPH
72H 10/1200Z 25.5N 80.0W 125 KT 145 MPH
96H 11/1200Z 30.1N 80.6W 105 KT 120 MPH
120H 12/1200Z 35.0N 82.0W 50 KT 60 MPH...INLAND

Thursday morning update: Extreme HURRICANE IRMA continues on an ominous track toward Florida. There is no good news overnight. Full hurricane preparations are required in peninsula Florida, and Georgia and the Carolinas should have preparations underway.
The main models that are easily visible to the public focus on the east coast of the state as the potential path of the core of the storm, and that raises the possibility of a devastating hurricane moving up the I-95 corridor, but with effects across the entire state. That may be the outcome. But the other models – the so-called ensembles - that give us an understanding of the uncertainty in the forecast, tell us that the entire peninsula is still at risk for the track for the worst part of the storm. And the cone covers the entire peninsula due to the known errors in forecasts for hurricanes 3 days in advance.
The bottom line is that everyone in southeast Florida – from the Keys through Miami-Dade, Broward, and Palm Beach County needs to prepare as if they knew Hurricane Andrew were coming. We certainly hope that doesn’t happen and that the worst of the storm ends up missing, but if you’re ready for Hurricane Andrew, you’re ready for anything. And that’s what we need to be: ready for anything. This is a greater hurricane threat to Florida than Andrew because it is so much bigger and will travel the length of the state.
It is possible that the worst of the storm could miss to the east, but we can’t bet on it, and the odds do not favor that happening at this point. So everybody in South Florida has to work together to get ready. Do not leave anything to chance.
In the rest of the state, follow the advice of your local officials. Evacuation decisions on the west coast are going to be very very difficult. The Gulf coast is extraordinarily vulnerable to life-threatening storm surge. If the storm were to track up the west coast of the state – which is only about 100 miles to the left, within the margin of average error – serious life-threatening storm surge would result. But ordering evacuations is a monstrous decision. People leaving Southwest Florida would have a long drive to safety – a drive that would mean using the same roads as people leaving the east-coast cities. I feel for the decision-makers.
In coastal Central and North Florida, a storm significantly stronger than Hurricane Matthew is a possibility, on, if anything, a worse track. Now is the time to prepare.
In interior Central Florida and points north, Hurricane Irma is also a serious threat. Be ready to stay home and take care of yourself if the power goes out, trees are down, and you are stuck in your neighborhood. Find the safest part of your house for you and your family, and know where you will park your car to avoid having it flooded or crushed by a falling tree. Have plenty of supplies to see you through a week without going out.
Irma is likely to affect ALL of peninsula Florida, and a good part of the Southeast. We can’t know exactly how yet, or where the absolute worst will be, but there are things that everybody can do to be ready, in case this incredible storm impacts your area.
If you are new to these posts, I listed things to do and think about on yesterday evening’s post.
Few people alive have experienced a storm like this. It is reminiscent of the great hurricanes that unleashed their fury on Florida in the first seven decades of the 20th Century… and then for the most part disappeared. We have to learn from those storms, and the main lesson is that we have to prepare, while we hope that we get a glancing blow. What you do this week, can have everything to do with how you live your life next week.
It is 99% sure that a hurricane is coming to Florida. Whether we get the absolute worst of it is another question, but waiting to prepare is rolling the dice. Preparation will only get harder as we get closer to Saturday when the wind will be blowing in the southern part of the state.

Good analysis



Sandy comparisons are tempting because we lived through it, but Sandy was a unique event in many ways. Even though it was a minimal hurricane the barometric pressure was equivalent to a high end cat three and storm surge flooding was equivalent to a category three or four because the storm was the largest ever so the winds piled the water onshore hour after hour.

Some effects are possible in the mid Atlantic and Northeast mid to late next week from what is left of Irma.

Thursday evening update: We’re getting down to crunch time. HURRICANE IRMA is on track to impact the southern part of the state beginning Saturday. In South Florida, tomorrow is your last day to prepare your home, business, car, or boat.
The big change today is that the (generally most reliable) European model has shifted to the west. The effect of this is simply to reinforce the fact that we cannot be absolutely certain EXACTLY where the worst of this hurricane is going to go. The only thing we feel certain about is that a large powerful hurricane is going to approach the peninsula of Florida on Sunday.
The bottom line: The entire peninsula needs to be if preparation mode. Anybody not preparing for the worst hurricane in decades is rolling the dice.

If the storm stays on the NHC track, Irma is going to push the ocean and the inland waterways – on BOTH the east and west coast of the state – over their banks potentially 10 feet over normally dry land. It won’t be that high everywhere, and in some places it could be a bit higher. There is no way to know exactly where the highest will be, so we have to plan for it to be extreme everywhere near the water.

BULLETIN
Hurricane Irma Advisory Number 38
NWS National Hurricane Center Miami FL AL112017
1100 AM EDT Fri Sep 08 2017

...EYE OF HURRICANE IRMA MONITORED BY HURRICANE HUNTER PLANES AND
CUBAN RADARS...
...HURRICANE CONDITIONS SPREADING WESTWARD OVER PORTIONS OF CUBA AND
THE CENTRAL BAHAMAS...


SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...22.0N 75.3W
ABOUT 270 MI...435 KM E OF CAIBARIEN CUBA
ABOUT 405 MI...655 KM SE OF MIAMI FLORIDA
MAXIMUM SUSTAINED WINDS...150 MPH...240 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...927 MB...27.38 INCHES

Hurricane. Irma Discussion Number 38
NWS National Hurricane Center Miami FL AL112017
1100 AM EDT Fri Sep 08 2017

Recent data from both NOAA and Air Force reconnaissance planes
indicate that Irma's intensity remains at 130 kt, although this
value could be 5 kt higher or lower. The central pressure has been
oscillating around 927 mb.

The environment continues to be favorable for Irma to maintain its
category 4 status, and only unpredictable eyewall replacement cycles
could result in intensity fluctuations during the next 48 hours.
Nevertheless, the NHC forecast brings Irma near south Florida as a
category 4 hurricane. Thereafter, interaction with land and an
increase in shear should induce gradual weakening.

Plane, satellite and radar fixes from Cuba indicate that the eye of
Irma is moving toward the west-northwest or 285 degrees at about 12
kt. The hurricane should continue on this track for the next 24
hours. After that time, Irma will reach the southwestern edge of
the subtropical high and begin to turn north-northwestward and
northward. This turn will occur, but the precise moment is still
uncertain, and that is why NHC emphasizes that nobody should focus
on the exact track of the center. The new NHC forecast was adjusted
just a little bit westward and is on top the latest ECMWF model and
the HFIP corrected consensus. In fact, these two aids are also very
close to each other.

KEY MESSAGES:

1. Irma is an extremely dangerous Category 4 hurricane and will
continue to bring life-threatening wind, storm surge, and rainfall
hazards to the Bahamas through Saturday. Hurricane conditions will
spread over portions of the north coast of Cuba, especially over the
adjacent Cuban Keys, through Saturday.

2. Irma is likely to make landfall in Florida as a dangerous major
hurricane, and will bring life-threatening wind impacts to much of
the state regardless of the exact track of the center.

3. There is the danger of life-threatening storm surge inundation in
southern Florida and the Florida Keys during the next 36 hours,
where a Storm Surge Warning is in effect. In particular, the threat
of significant storm surge flooding along the southwest coast of
Florida has increased, and 6 to 12 feet of inundation above ground
level is possible in this area. This is a life-threatening
situation. Everyone in these areas should take all actions to
protect life and property from rising water and follow evacuation
instructions from local officials.

4. Irma is expected to produce very heavy rain and inland flooding.
Total rain accumulations of 4 to 12 inches, with isolated amounts of
20 inches are expected over the Florida peninsula Saturday through
Monday. The highest amounts are expected over the eastern Florida
peninsula and upper Florida Keys. Irma will likely bring periods of
heavy rain to much of Georgia, South Carolina, and western North
Carolina early next week, including some mountainous areas which are
more prone to flash flooding. All areas seeing heavy rainfall from
Irma will experience a risk of flooding and flash flooding.

Friday morning update: Extraordinary HURRICANE IRMA continues on track. It will move into the Florida Straits just north of the Cuban coast tomorrow (Saturday) and turn to the north toward Florida during the day.
It is impossible to know the exact angle of the turn, though we are confident it will happen. The possibility that the worst of the storm will go closer to the Florida west coast or the east coast appear about even.
The storm has weakened a bit, down to 150 mph. There is opportunity for it to weaken a bit more if the circulation interacts with Cuba, but it could also restrengthen some over the Florida Straits south of the Keys.
The models overnight are split. The European model and some other behind-the-scenes models the National Hurricane Center uses – which have had the best accuracy so far with Irma – bring the eye of the hurricane with the worst winds closer to the west coast of the state than the GFS and some other models, which take it closer to the east coast. Both models and most imaginable tracks bring the core of the storm over the Florida Keys.
If the Euro track materializes, or anything like that, residents along the west coast of Florida who live near the water are in peril. Be sure you have taken all precautions to get away from areas that the Gulf may swamp in that scenario.
Taken together, the models and the NHC cone accentuate the fact that the entire state is at risk, and everyone needs to fully prepare for an unprecedented storm.
The threat is to Florida is EXTREME. This is not like any hurricane we have experienced in modern times. The closest is giant Hurricane Donna in 1960. This will be a long-duration event. You will have to be ready to stay in your safe spot for 12 hours or longer, depending on where the strongest winds track. Beyond the, the winds will blow hard for the best part of two days. It will affect the entire state, except the far western panhandle.
Even with excellent modern computer models, the exact track of the core of the hurricane, where the strongest winds occur, is critical, but not forecastable. We won’t know exactly who will be subject to the winds in the eyewall – forecast to be Category 4 – until hours before it happens. Outside the core, the winds will still be damaging, but not devastating. But damaging will will extend far from the eye.
We all need to prepare as if we knew 100% that the core of the hurricane were coming over our home, which means we prepare like we’re expecting Hurricane Andrew. Then we hope for the best. A jog of 25 miles, can make a tremendous difference.
Outside of the core, the very strong winds blowing over the water will drive the Atlantic into the east coast and the Gulf into the west coast. The west coast is extremely vulnerable to storm surge. Unless they get very lucky, life-threatening storm surge will occur from southwest Florida to the Big Bend. The surging water could go miles inland. Be very very careful not to remain in a dangerous location.
In South Florida, today is your last chance to prepare yourself and your family. What you do today can make a difference in the rest of your life. The decisions you make may be the most important of your life. Get to high ground if you live near the water. Find a strong building in which to ride out the storm. Park your car where it can survive flooding and flying debris.
The threat will expand north. I expect all of Florida except the Panhandle to eventually be under hurricane warnings. Do not be a victim. Take action so Hurricane Irma is an inconvenience, not a life-changing event.

Just a quick Friday afternoon update on HURRICANE IRMA. I’m on The Weather Channel today from 5:00 to 9:00 PM ET.
The top winds in Irma have decreased a little bit from yesterday. Do NOT think of this as weakening. The energy of the hurricane is simply spreading out – which just further guarantees the entire state of Florida, except the western panhandle, will get damaging winds from the storm.
We still don’t know where exactly where the fiercest winds with hit. The afternoon computer models have shifted to the west. If that turns out to be the final track, the Miami to West Palm Beach corridor will not receive the strongest winds in the storm. But, until Irma makes the turn toward Florida, we can’t be sure and, certainly, no one should let down their guard.
This westward shift just further confirms that the west coast of the Florida is at an extremely high risk of dangerous flooding from the Gulf water being pushed over the land – most likely late Sunday into Monday in Southwest Florida, then moving up the coast. Do not risk your life if you are in dangerous location. Every county knows where those areas are. Know your risk.
The hazards will move north over the ENTIRE peninsula through the weekend, including life-threatening storm surge along both coasts and on bays, rivers, and canals connecting to the ocean. The strongest winds will decrease as Irma moves north, but the trees and buildings in West, Central, and North Florida are not as resilient to strong wind as they are in Greater Miami, so the extreme threat continues.
Look for failure points in your home, and trees that could blow down on your house or your car. Be sure you plan to stay in a part of the house that is as protected as possible from flying debris or falling trees. Consider getting mattresses off your bed to fortify your safe spot as the storm approaches over the weekend.
This is it, South Florida. Your last chance for full preparation. And the window is closing farther north in the state.


NHC’S KEY MESSAGES:
1. Irma will continue to bring life-threatening wind, storm surge,
and rainfall hazards to portions of the Bahamas and the north coast
of Cuba, especially over the adjacent Cuban Keys, through Saturday.
2. Irma is expected to make landfall in Florida as an extremely
dangerous major hurricane, and will bring life-threatening wind
impacts to much of the state regardless of the exact track of the
center.
3. There is the danger of life-threatening storm surge inundation in southern Florida and the Florida Keys during the next 36 hours where a Storm Surge Warning is in effect. The threat of significant storm surge flooding along the southwest coast of Florida has increased, and 8 to 12 feet of inundation above ground level is possible in this area. This is a life-threatening situation.Everyone in these areas should take all actions to protect life and property from rising water and follow evacuation instructions from local officials.
4. Irma is expected to produce very heavy rain and inland flooding. Total rain accumulations of 8 to 15 inches, with isolated amounts of 20 inches are expected over the Florida Keys and much of the Florida peninsula through Tuesday night. The highest amounts are expected over the eastern Florida peninsula and upper Florida Keys. Irma
will likely bring periods of heavy rain to much of Georgia, South Carolina, and western North Carolina early next week, including some mountainous areas which are more prone to flash flooding. All areas seeing heavy rainfall from Irma will experience a risk of flooding and flash flooding.

...IRMA MAKING LANDFALL ON THE CAMAGUEY ARCHIPELAGO OF CUBA AS A
CATEGORY 5 HURRICANE...
...HURRICANE WARNINGS EXTENDED NORTHWARD ALONG THE FLORIDA
PENINSULA...


SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...22.1N 77.7W
ABOUT 120 MI...190 KM ESE OF CAIBARIEN CUBA
ABOUT 300 MI...485 KM SSE OF MIAMI FLORIDA
MAXIMUM SUSTAINED WINDS...160 MPH...260 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...924 MB...27.29 INCHES

Hurricane Irma Discussion Number 40
NWS National Hurricane Center Miami FL AL112017
1100 PM EDT Fri Sep 08 2017

An Air Force Hurricane Hunter flight has found that Irma has
re-intensified to category 5 strength. The plane measured a
maximum flight-level wind of 154 kt and SFMR winds of 140-145 kt in
the northwestern eyewall, so the initial intensity is raised to 140
kt. The hurricane is producing very deep convection in all
quadrants around the eye, which the Air Force flight measured to be
35 n mi wide.

Apparently the ridge to the north of Irma has been stronger than
expected, and the initial motion remains westward, or 280/11 kt.
The track guidance continues to insist on Irma turning
west-northwestward soon, moving along the Cuban Keys adjacent to
the north coast of Cuba during the next 24 hours. After that time,
Irma is expected to turn sharply north-northwestward and accelerate
after 48 hours, moving parallel to the west coast of Florida and
then into Georgia. Mainly because Irma's eye has not deviated from
its westward motion, the new NHC forecast track has again shifted
slightly westward. Because of the hurricane's angle of approach to
the west coast of Florida, it is extremely difficult to pinpoint
exactly where the center might move onshore.

If the eye continues to move over the Cuban Keys and does not move
inland over the main island of Cuba, then Irma would likely not
lose much intensity during the next day or so. As we've stated
many times, fluctuations in intensity are likely during the next 36
hours due to possible and unpredictable eyewall replacement cycles.
After 36 hours, there are some indications that vertical shear may
increase over the hurricane, and a little more weakening is
anticipated at that time. Because of the concerns in the track
forecast noted above, Irma would be able to maintain a strong
intensity for a longer period of time if the center stays off the
west Florida coast. Regardless, Irma is still expected to be a
dangerous hurricane as it approaches the Florida Keys and the west
coast of Florida through 48 hours.

Northern Cuba is getting raked. As for Florida on the east coast storm surge will be a problem because the winds will be blowing so long but otherwise it is looking a lot less likely they will get the devastating hit feared. It will still be a dangerous storm with lots of trees and power lines down and debris flying around. The Keys especially the lower half and the Florida southwest coast are under a large threat for a devestating hit. Thing is a lot of people evactuated the east coast for the west coast. Could this change, of course mother nature is in charge as always but as we get closer chances of a major change drop.

BULLETIN
Hurricane Irma Advisory Number 42
NWS National Hurricane Center Miami FL AL112017
1100 AM EDT Sat Sep 09 2017

...IRMA CONTINUES TO POUND THE NORTH COAST OF CUBA...
...FORECAST TO RESTRENGTHEN WHILE HEADING FOR SOUTH FLORIDA AND THE
KEYS...


SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...22.8N 79.8W
ABOUT 90 MI...145 KM ESE OF VARADERO CUBA
ABOUT 175 MI...285 KM SE OF KEY WEST FLORIDA
MAXIMUM SUSTAINED WINDS...125 MPH...205 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...941 MB...27.79 INCHES

Hurricane Irma Discussion Number 42
NWS National Hurricane Center Miami FL AL112017
1100 AM EDT Sat Sep 09 2017

The interaction of Irma's circulation with Cuba has resulted in
some weakening of the hurricane. Data from an Air Force plane
indicate that the maximum winds are now 110 kt. However, once the
circulation moves away from Cuba, restrengthening is forecast and
Irma is expected to remain a very dangerous hurricane for the next 2
days while moving very near the Florida peninsula.

The eye has been moving toward the west or 280 degrees at about 8
kt. The hurricane is about the reach the southwestern portion of
the subtropical high, and the expected turn to the northwest and
north-northwest should begin soon. The track guidance is tightly
packed and takes the hurricane over the Florida Keys and near or
over the Florida Peninsula. The NHC forecast is in the middle of
the guidance envelope and given the good agreement among models, the
confidence in the track forecast is high.

Irma is now under the scope of Key West radar, so hourly updates
will begin at 1600 UTC.

KEY MESSAGES:

1. Irma will continue to bring life-threatening wind, storm surge,
and rainfall hazards to portions of the Bahamas and the north coast
of Cuba, especially over the adjacent Cuban Keys, through tonight.

2. Irma is expected to make landfall in Florida as an extremely
dangerous major hurricane, bringing life-threatening wind
impacts to much of the state regardless of the exact track of the
center. Wind hazards from Irma are also expected to spread northward
along the coast of Georgia and South Carolina where a Hurricane
Watch has been issued.

3. There is an imminent danger of life-threatening storm surge
flooding in portions of central and southern Florida, including the
Florida Keys, where a Storm Surge Warning is in effect. The threat
of catastrophic storm surge flooding is highest along the southwest
coast of Florida, where 10 to 15 feet of inundation above ground
level is expected. This is a life-threatening situation and everyone
in these areas should immediately follow any evacuation instructions
from local officials.

4. Irma is expected to produce very heavy rain and inland flooding.
Total rain accumulations of 10 to 20 inches, with isolated amounts
of between 20 and 25 inches, are expected over the Florida Keys, the
Florida peninsula, and southeast Georgia from Saturday through
Monday. Significant river flooding is possible in these areas. Early
next week Irma will also bring periods of heavy rain to much of the
southeast United States where an average of 2 to 6 inches is
forecast, with isolated higher amounts, from North and South
Carolina to Tennessee and eastern Alabama. This includes some
mountainous areas which are more prone to flash flooding. Residents
throughout the southeast states should remain aware of the flood
threat and stay tuned to forecasts and warnings.

Saturday morning HURRICANE IRMA update: Irma’s assault on the State of Florida has begun. Winds are getting gusty on the southeast coast and in the Keys. The gusts will increase in surges through the morning and spread north through the day.

The center of Hurricane Irma ran into the coast of Cuba overnight resulting in some weakening of the highest winds – now down to 130 mph. While that’s not a bad thing – except for our friends along the north coast of Cuba – it doesn’t necessarily make any difference to Florida. Between Cuba and Florida, the water is extremely warm. Meanwhile the atmosphere will be conducive to Irma restrengthening.

All of peninsula Florida is still expected to receive damaging hurricane-force winds. Nobody should let down their guard because of the storm’s interaction with the Cuban coast this morning. It is still a giant, tremendously dangerous storm of the type that peninsula Florida hadn’t seen since Hurricane Donna in 1960.

The forecast track for the worst of the storm is now squarely on the Lower Florida Keys and Florida’s extremely vulnerable west coast. Here’s what this means for the various parts of the state and surrounding states:

In South Florida from MIAMI TO THE PALM BEACHES, think Hurricane Wilma in terms of the wind. There will be an extended period from later today through tomorrow of strong, dangerous winds, but not the full-scale assault that would have happened if the eye had come closer.

In addition, however, flooding rainfall of a foot or more, plus rising sea water – storm surge of 5 feet or more in vulnerable low-lying locations – is still possible.

In the FLORIDA KEYS, it is a full-scale hurricane emergency. Key West is probably going to get its worst storm in modern history, and perhaps ever. Life-threatening weather conditions will overtake the Keys later today and peak tomorrow morning, although Florida Bay water will continue to rise after the center passes to the north. Ultimate hurricane protection is required for anyone remaining in the Keys. Be sure you have a solid high-elevation location to ride out the storm. The danger from rising water due to storm surge and rainfall, as well as wind, will be extreme.

In SOUTHWEST FLORIDA – the NAPLES-FT. MYERS-CAPE CORAL area, the potential exists for the worst hurricane in history. The core of Hurricane Irma, potentially with winds gusting over 150 mph or more, is going to come close. Buildings in Southwest Florida are not, in general, built to withstand these winds. As the peak winds approach the Gulf water will surge over the islands and the shoreline of the mainland, so it will be very difficult or impossible to move once the storm starts.

Once the eye goes by, the maximum surge – forecast to be 8 to 12 feet above the ground in low-lying areas – will move in from the Gulf. This is fast moving, destructive water. You cannot drive through it and you cannot stand in it. It will sweep buildings away. Storm surge is the deadliest hazard in a hurricane.

The water will surge miles inland in some areas – far up the Caloosahatchee River, for example – higher than you can imagine. It is critical that everyone makes it to high ground.

Ultimate hurricane protection is required in all of Southwest Florida. Be sure you are in an elevated location by tonight. Inside the house or building, prepare an interior hall, closet, or bathroom with as many walls between you and the outside of the building as possible. Have the food and supplies you need with you, so you don’t have to venture to other parts of the house or building during the peak of the storm.

Have mattresses handy as an extra layer of safety. Be ready to get under the mattress or use them to protect yourself from flying debris inside your house, if there is a breach of the outside wall or the roof.

Think about everything today. How are you going to entertain the kids? How are you going to take care of your pet? Take no chances. This is an extraordinarily dangerous situation.

Farther north on the WEST COAST OF FLORIDA – SARASOTA, TAMPA BAY, AND POINTS NORTH: The threat of deadly storm surge is real and increasing. It is essential that you get out of low-lying areas. Follow the local evacuation orders, which are still being issued.

On the current track, the wind will be fierce and damaging along the entire west coast. Review the steps listed above to stay safe if you are going to be near the eye of the storm, even well away from the water.

Along the EAST COAST OF FLORIDA, AND COASTAL GEORGIA AND SOUTH CAROLINA, there storm surge threat is very real, and it may be worse than Hurricane Matthew last year, even with Irma tracking farther west. Listen for information from your local officials and obey all evacuation orders.

Elsewhere in CENTRAL AND NORTH FLORIDA – INCLUDING ORLANDO AND GAINESVILLE: Damaging hurricane force winds are expected for a long duration moving from south to north beginning late tonight (Saturday night).

Be sure you are in a sturdy building and are prepared to move to an inside hallway, closet, or bathroom during the height of the storm, which is going to go on for 12 hours or more. Have entertainment for the kids, and think about how the pets are going to go to the bathroom. Consider having a mattress handy in case a window breaks or somehow the wind gets into your house.

For all of Peninsula Florida, this is going to a long slog of weather conditions ranging from deadly to damaging to frightening to horribly uncomfortable. Millions of us will lose power. Hundreds of miles of coastline will be damaged. And some people will lose their lives.

There are still things you can do to make you life better after the storm. You'll see a list below, and a shopping list, if stores are still open in your location. Also, you’ll see Key Messages from the National Hurricane Center.

Today is the warm-up. Some dangerous conditions will begin in the southern peninsula, but tonight is when the full assault will commence. BE READY. HELP YOU NEIGHBORS. STAY SAFE.