NASA and NOAA see massive rainfall and winds in Hurricane Irma – now Cat3



At 500 PM AST (2100 UTC), the center of Hurricane Irma was located near latitude 18.8 North, longitude 39.1 West. Irma is moving toward the west near 13 mph (20 km/h). A turn toward the west-southwest is expected tomorrow.

Maximum sustained winds are near 120 mph (195 km/h) with higher gusts. Irma is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Fluctuations in strength, up or down, are possible during the next few days, but Irma is expected to remain a powerful hurricane through the weekend.

Hurricane-force winds extend outward up to 25 miles (35 km) from the center and tropical-storm-force winds extend outward up to 105 miles (165 km).

The estimated minimum central pressure is 964 mb (28.47 inches).


NASA gets a night-time and under-the-hood look at Hurricane Irma

NASA-NOAA’s Suomi NPP Satellite provided a night-time and infrared look at the Atlantic’s latest hurricane that revealed the power under the clouds. NASA’s GPM also provided a look at the rainfall being generated by Hurricane Irma.

After forming in the eastern Atlantic Ocean on Wednesday tropical storm Irma strengthened and became a powerful category three hurricane on Thursday August 31, 2017.


Finding Irma’s Heaviest Rainfall

That heavy rainfall was confirmed by the Global Precipitation Measurement mission or GPM core satellite.

Hurricane Irma was moving west-northwestward with winds of about 115 mph (100 knots) when the GPM core Observatory satellite saw it on September 1 at 1:47 a.m. EDT (0547 UTC). Data collected by GPM’s Microwave Imager (GMI) and Dual-Frequency Precipitation Radar (DPR) instruments showed the locations and intensity of heavy precipitation within the hurricane. GPM’s Radar (DPR Ku band) found that a powerful convective storm in a band of rain on Irma’s northern side was dropping rain at a rate of almost 6.3 inches (159 mm) per hour.

On Sept. 1 at 0347 UTC (Aug. 31 at 11:47 p.m. EDT) the VIIRS instrument aboard NASA-NOAA’s Suomi NPP satellite captured a night-time infrared image of Hurricane Irma in the Atlantic Ocean that showed powerful thunderstorms around the eye. Credits: NASA/NOAA/UWM-CIMSS, William Straka III

GPM’s radar (DPR Ku Band) showed the height and the 3-D rainfall structure of powerful storms spiraling around hurricane Irma. DPR showed that storm tops were reaching heights of over 9.6 miles (15.5 km) in the band of powerful convective storms north of the hurricane’s center. GPM is a joint mission between NASA and the Japanese space agency JAXA.

On Sept. 1 at 1:47 a.m. EDT (0547 UTC) GPM core observatory found a band of rain on Irma’s northern side was dropping rain at a rate of almost 6.3 inches (159 mm) per hour where storm tops were reaching heights of over 9.6 miles (15.5 km). Credits: NASA/JAXA, Hal Pierce

Irma’s Location and Strength on Sept. 1

The National Hurricane Center (NHC) said that at 11 a.m. EDT (1500 UTC) on Sept. 1 that Irma was undergoing an eyewall replacement cycle. The small eye was becoming less distinct, with both microwave and visible imagery indicating the presence of a forming outer eyewall.

On Sept. 1 at 0347 UTC (Aug. 31 at 11:47 p.m. EDT) the VIIRS instrument aboard NASA-NOAA’s Suomi NPP satellite captured a night-time image of Hurricane Irma in the Atlantic Ocean that showed a tight circulation. Credit:
CREDIT Credits: ASA/NOAA/UWM-CIMSS, William Straka III

The center of Hurricane Irma was located near 18.5 degrees north latitude and 27.8 degrees west longitude. That’s about 1,580 miles (2,540 km) east of the Leeward Islands. Irma was moving toward the west-northwest near 13 mph (20 kph). A turn toward the west is expected by tonight, followed by a turn toward the west-southwest on Saturday, Sept. 2.

Maximum sustained winds are near 110 mph (175 kph) with higher gusts. Fluctuations in strength, up or down, are possible during the next few days, but Irma is expected to remain a powerful hurricane through the weekend. Hurricane-force winds extend outward up to 15 miles (30 km) from the center and tropical-storm-force winds extend outward up to 90 miles (150 km).

The estimated minimum central pressure is 972 millibars.

The NHC predicts that hurricane Irma will slowly intensify while heading toward the west-northwest. Irma is predicted to have winds of over 123 mph (110 knots) within the next five days. This would make Irma a strong category 3 hurricane on the Saffir-Simpson hurricane wind scale. There is some uncertainty about the long term direction of Irma’s movement.


83 thoughts on “NASA and NOAA see massive rainfall and winds in Hurricane Irma – now Cat3

  1. The predicted tracks are very uncertain right now including missing land altogether in a few runs but this hurricane will be a Cat5 at some point and you don’t want to be on the right side of the eyewall when/if it hits land.

  2. I have tried to explain to some people about the effect of the wind changing direction when you are in the direct path and they don’t really get it. Been in the eye of 3 different hurricanes, its much scarier in the dark.
    I have been checking Irma on AccuWeather HC and watching it of&on through and she is building up to be a right bitch.

      • I been checking movement and rainfall, did not look at that. Wow, that is a big assed hump in the ocean, if it combines with a high tide during any landfall it will be a monster.

      • Sorry – impossible. You are not going to get a lift of water around 33ft with only 120 mph wind that is 50 miles wide. Now, you can get waves that high, no problem.

      • JKrob, maximum lift (hump) must coincide with the same limit for suction pumps < 7to 8m. Incidentally, thanks, you gave me an insight (certainly well known to hurricane specialists, I'm sure) that all that water that falls as rain is the suction evaporated water lifted from the "hump".

  3. Hoping it takes a hard right up east coast. One every 12 years is enough.
    SARC below:
    Maybe we can redirect all those windmills and deflect it?
    Or install a few billion floating balls in its path to restrict it’s water uptake? Or maybe put Obama and Gore in a small boat to tame it, and make it behave before it becomes a catagory 6?
    So many options, going to need a lot of $ FAST to study it and find a solution.

  4. Experiencing a few hurricanes myself growing up in the Virgin Islands, my parents always taught me to never buy a house at the bottom of a hill. As a six year old child it seemed only logical. Today, it is just common sense.
    There, in the Virgin Islands, if you were ‘well to do’, you lived in the hills. In North America the ‘well to do’ live near the ocean/rivers. Yet the ‘well to do’ have the best insurance policies. Well… that is just common sense isn’t it……

    • Clearly you have never priced flood insurance. The first $250,000 is Federal and fairly cheap. Everything above 250 is private and really expensive. I was once in charge of taking care of a $10 million house for an estate. I decided to rely on the power of prayer.

      • It is obviously common sense to stop building houses in flood-plains or at the beach where a hurricane hits every 20 years.
        But somebody owns that land now and how do you say that land you bought is now basically worthless. They fight back and they have money so it is very difficult for any government or regulator. And then the developers tend to have inside influence which can’t even be under-estimated. Developers run rough-shod over most municipalities in case you didn’t know.
        Any government-owned land in those areas should be a strict building moratorium area and then one has to say “you knew what the rules were when you bought this land” (whatever those were) and don’t let developers change the rules afterward. Otherwise, NO insurance. They should take the loss when they build in a place which is obviously a once-in-20-year-loser investment.

      • Bill,
        Local governments are tasked with developing land to the highest and best use in order to collect the most in property taxes for their local governments. Since local governments do not fund flood insurance or foot the bill for major disaster relief, they do not care. But as I posted on another thread, should we ban all building in tornado prone areas, ice storm areas, earthquake areas and any other area that might suffer a natural disaster? Why not ban building altogether and return to being hunter gatherers where only the strong survive.

      • You all have good points. Just suggesting, human memories are good for about 20 years or so. Why are we so shocked when natural disasters happen, when we’ve placed ourselves in the path. Unfortunately the insurance companies will pay to rebuild “exactly” what was destroyed, at the exact same elevation, with the exact same materials. Everyone will be happy for the next 20 years…..wash, rinse, repeat, we shall be shocked again (possibly this year).

        • It has always amazed me how local and state building code agencies make it so difficult and expensive to innovate building design and materials in regions where natural disasters are the norm. They fight tooth&nail to keep people doing the same thing and using the same materials. It is pretty well impossible to build a hurricane/tornado/wildfire proof structure, but you can damned well harden them against damage. And you would think insurers would be leading the charge on this.
          Just checked latest track plots at AW Hurricane center and they are showing it moving at 13 mph in a generally westward line, think Puerto Rico and Dominican Republic may take this one right in the teeth.

      • .

        It is obviously common sense to stop building houses in flood-plains or at the beach where a hurricane hits every 20 years.

        The other answer is stop building flimsy wooden structure that blow away in the wind. We have the technology to build seismic resistant and storm resistant structures. Yet look at all the debris. it is basically pathetic wooden shacks that crumple in high winds.

      • Not completely true. I once visited a rich man on the Kona coast of Hawaii. While his house was not on pylons, it had a very open, fairly tall, ground floor with only a bit of storage. The residence was at least 10 ft above ground level, let alone sea level. (I’d not be surprised if he self-insured.)

  5. I’m praying it stays out at sea. The Northeast hasn’t fully recovered from Sandy yet and Harvey’s cleanup and rebuilding will take untold years. Irma already looks scary as sh*t.

  6. On the Gold Coast in SE Queensland, Australia, we haven’t had a serious cyclone since 1976 when we used to get half a dozen a year quite regularly for decades prior.
    Development has skyrocketed but memories have faded. Sites where houses were washed out to sea 50 years ago have houses that have changed hands for multi-millions.
    We all know the verdict when normal weather returns.

  7. Those spaghetti lines seem to suggest that the Lesser Antilles will only be grazed, with the Greater Antilles will also be similarly spared. Those living or vacationing in the Bahamas will really have to worry, though. And if the general track holds, it looks like the south Atlantic US coast (between Virginia and Florida) will be in for a pounding.

  8. Health, auto, and homeowners’ insurance institutions drive up costs, create enormous bureaucracies, delay recovery and repair, intrude in and exploit people’s private lives (by gathering and selling data), and encourage people to engage in worse health, driving and building practices than they would otherwise have.
    Nothing would hold doctors’ feet to the fire more effectively than a direct pay system that forced them to explain diagnoses, treatment options and costs to patients.
    Do world’s-safest drivers who subject themselves to State Farm’s or other companies’ “telematics” tracking procedures actually experience cheaper rates? How much cheaper than other drivers? And how much information is Nationwide hawking on the open market?
    (from one presently engaged in re-roofing after hail): the behind-the-scenes shenanigans between adjusters and roofers; the disconnect between actual costs of re-roofing and the payouts; the difficulty in making needed improvements in an older house… are jaw-dropping!
    “Leaders” who announce “We’ll have you rebuilt in no time… just the way you were,” are enabling the problem to persist. Individual owners and businesses will have to take the lead to bullet-proof their homes and workplaces because there is little genuine incentive to improve things beyond the status quo.

    • Would a metal roof have prevented the hail damage you’re fixing?
      (I have one and it only became noisy, not damaged, in a big hailstorm. (No big stones in it though.)

      • Pound on your roof with a hammer and if the dents don’t bother you’re good to go. Personally I like my metal roof a lot.

  9. So the track is he trick. Anyone want to bet on where it will make landfall? I will say northern GA or southern SC… any other predictions? (i’ll say just south of Charleston, SC)…
    if you win you get a free ticket to _____________…

      • I’ve wondered why they don’t name hurricanes with more “appropriate” names – like Death Megatron or Poison Wind or Savage Butcher or something. Prolly get a lot more evacuation with those names.

  10. “Maximum sustained winds are near 120 mph”
    Curious, is this wind speed at the surface?
    Spoke to a retired MIT Prof who know works for NOAA. When I asked him about the difference
    between reported wind speeds and actual wind speeds at ground level. He was quite direct
    about it saying cat 3/4/5 are very rare because of the friction at lower altitudes to the cyclonic winds.
    It seems that we reduce the significance of older storms when aircraft measurements were not possible.
    Back then measurements were made on ground and from ships at sea.
    It seems we are embracing and apples and oranges comparison.

    • Supposedly the final formal classification of these storms based on wind speeds taken from unobstructed sites 10 meters from the ground.

    • Yes, I agree w/the apples & oranges idea. It’s a crock to rate hurricane winds from high in the air when the effects are on the ground where the wind damage occurs. It is an inaccurate rigged system, but since it meets the needs of bureaucrats it won’t change.
      I live in FL at sea level. Water more worrisome than wind in most situations.

      • I live 500′ above the Mississippi in Wisconsin. I’ll be watching with the casual disinterest of someone who chose a reasonably secure location to live. Good luck.

  11. I’m guessing on missing the West Indies and Bahamas just, and Florida, and grazing up the East coast with a 50 50 chance of mayhem in and around the NY area or pottering off into the jetrsream and dumping bad weather on the UK…

    • I don’t see a high pressure system coming from the south to force Irma into a northern track. Everything I am finding is showing a continued track south of 20th parallel. Possible striking Puerto Rico and Dominican Republic could push her into a track through Straits of Florida into Gulf, worst of all possible scenarios. She is still running west at 12-15 mph and still very compact. Going to start prelim loadout this afternoon, shoiuld know what this bitch is going to do by Wed. morning.

    • What is the status of that circulating low just west-north-west of Irma? That looks like it might be developing as well.

  12. Seems a little spot of dry air and cooler SSTs have retarded development for now but she’ll no doubt ramp back up again as she moves into the more favorable conditions to the west.

  13. If this one turns NW, it is likely to give Bahamas a blow and then slide up the coastline ~along SCarolina and north. It seems to me hurricanes approaching that coast at an acute angle tend to follow the coast northward, as if the warm water offshore pulls it seaward instead of slanting inland. Speculation,but a lot of hurricanes have followed this path under these geometric conditions.

  14. Here’s Mann’s chance to tell us just how “climate change” will make it worse before the fact rather than after the fact.
    (I’m assuming he already knows whether it will or will not make landfall.)

  15. Keep in mind, Irma is a small storm. It will intensify quickly but also diminish quickly. Also the models have been trending away from the US East Coast. Let’s hope that trend continues.

  16. It is called a Hurricane. Someone have the guys at NASA Google that and look at what destruction they used to bring routinely to the North American Continent…. oh yeah, that was until the warmist nutjob Al Gore predicted many more and more intense storms to come than Katrina (Cat 3) in 2005. Finally we had a mini-Hurricane that turned into a Tropical Storm Rain Event….albeit a very bad rain event, but only because it sat on top of the 4th largest city in North America for 3 days.

  17. The animation shows a strong east current in the Caribbean Sea. This may mean a return to rain on the Texas coast.

    • Hurricane IRMA
      As of 00:00 UTC Sep 04, 2017:
      Location: 17.3N 50.4W
      Maximum Winds: 100 kt Gusts: 120 kt
      Minimum Central Pressure: 959 mb
      Environmental Pressure: 1012 mb
      Radius of Circulation: 240 NM
      Radius of Maximum Wind: 15 NM
      Eye Diameter: N/A
      Atmospheric pressure decreases. Latitude decreases. The hurricane is moving to the Lesser Antilles.

      • She has definitely held well below 20th, AccuWeather lists her as being down to 17.5 and still tracking west at 12-15mph. Eyewall appears to have opened up in the last few hours which usually is an indication of increasing strength. She is still compact, all the same, which is damned worrying.

Comments are closed.