Hurricane Ian makes landfall in Florida

September 29th, 2022 |

GOES-16 “Clean” Infrared Window (10.3 µm) and “Red” Visible (0.64 µm) images [click to play animated GIF | MP4]

Overlapping 1-minute Mesoscale Domain Sectors provided 30-second interval GOES-16 (GOES-East) “Clean” Infrared Window (10.3 µm) and “Red” Visible (0.64 µm) images (above) during a 7-hour period that included the landfall of Hurricane Ian along the southwest coast of Florida at 1905 UTC (Visible | Infrared) on 28 September 2022. Moving across very warm water (where buoy Sea Surface Temperature values were 82-85ºF), Ian intensified to a Category 4 hurricane at 1200 UTC, and further intensified as it neared the Florida coast to just below Category 5 strength (rated at 135 knot sustained winds). As Ian moved inland, peak wind gusts were as high as 140 mph, and heavy rainfall exceeded 10 inches within a 4-hour period (WPC Storm Summary). These strong winds quickly resulted in power outages to 96-99% of customers in DeSoto, Charlotte and Lee Counties by 2244 UTC — note the disappearance of surface plot data in the GOES-16 imagery after 20 UTC at sites such as Venice (peak gust 90 knots / 104 mph), Punta Gorda (peak gust 117 knots / 135mph) and Fort Meyers (peak gust 87 knots / 100 mph).

30-second GOES-16 Visible images with time-matched plots of GLM Flashes (below) indicated that lightning activity within the eyewall decreased as the eye of Ian approached the coast.

GOES-16 “Red” Visible (0.64 µm) images, with plots of GLM Flashes [click to play animated GIF | MP4]

In a comparison of ~500-meter resolution GOES-16 Visible and ~15-meter resolution Landsat-8 Operational Land Imager Panchromatic images valid at 1557 UTC — viewed using RealEarth (below) — the Landsat image provided a more detailed view of the cloud structures within the eye of Hurricane Ian as it was just off the west coast of Florida.

GOES-16 “Red” Visible (0.64 µm) and Landsat-8 Panchromatic (0.59 µm) images, valid at 1557 UTC [click to enlarge]

A closer look at the 15-meter resolution Landsat-8 Panchromatic image is available here.

Fiona intensifies to a Category 4 hurricane

September 21st, 2022 |

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images [click to play animated GIF | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed Fiona as it intensified to a Category 4 Hurricane just east of The Bahamas at 0900 UTC on 21 September 2022. The coldest cloud-top 10.35 µm infrared brightness temperatures were around -81ºC.

GOES-16 Infrared images with and without a overlay of GLM Flash Extent Density (below) did reveal isolated brief periods of lightning in the eyewall region of Fiona — but most of the lightning activity was associated with convection well east of the eye.

GOES-16 “Clean” Infrared Window (10.35 µm) images, with and without a overlay of GLM Flash Extent Density [click to play animated GIF | MP4]

The corresponding 1-minute GOES-16 Cloud Top Temperature and Cloud Top Height derived products are shown below — the coldest Cloud Top Temperature values were around -84ºC, while maximum Cloud Top Height values were around 58,000 feet.

GOES-16 Cloud Top Temperature and Cloud Top Height derived products [click to play animated GIF | MP4]

In a time-matched comparison of Infrared Window images from Suomi-NPP and GOES-16 at 0700 UTC (below), the coldest cloud-top infrared brightness temperatures were -86ºC and -81ºC, respectively. A slight northwestward parallax displacement was evident with the GOES-16 image.

Infrared Window images from Suomi-NPP (11.45 µm) and GOES-16 (10.35 µm) [click to enlarge]

===== 23 September Update =====

GOES-16 “Clean” Infrared Window (10.35 µm) images [click to play animated GIF | MP4]

As Fiona passed just to the northwest of Bermuda during the nighttime hours on 22-23 September, it was briefly downgraded to a Category 3 storm at 0600 UTC (before being again upgraded to Category 4 at 1200 UTC on the following morning) — but a wind gust to 81 knots (93 mph) was recorded at Bermuda Naval Air Station (station identifier TXKF) shortly before 10 UTC while that airport was temporarily closed to air traffic (Bermuda discussion). 1-minute GOES-16 Infrared images (above) showed Fiona during the 0000-1000 UTC period on 23 September.

A DMSP-17 SSMIS Microwave (85 GHz) image at 1053 UTC from the CIMSS Tropical Cyclones site (below) exhibited the eye and eyewall structure about an hour after the peak wind gust at Bermuda.

DMSP-17 SSMIS Microwave (85 GHz) image at 1053 UTC [click to enlarge]

LIS observations over Typhoon Hinnamnor

September 1st, 2022 |
Himawari-8 Band 13 Infrared imagery (10.41 um) and LIS Flash Events, 1539-1542 UTC on 1 September 2022

The International Space Station carries a variety of instruments, including the Lightning Imaging Sensor (LIS), designed to extend the Lightning Climatology from the Tropical Rainfall Measuring Mission (TRMM). ISS overflew Typhoon Hinnamnor at about 1540 UTC on 1 September (image, from this site). The lightning animation above (click here for an animated gif) shows data from 1539 UTC until 1543 UTC, with >80 flash events occurring.  The observed lightning is far from the ragged eye of the storm.

The Joint Typhoon Warning Center (link) and the Japan Meteorological Agency (link) have more information on this typhoon.  Previous blog posts on Hinnamnor are here and here.  Himawari-8 data are courtesy JMA.

 

Super Typhoon Hinnamnor once again reaches Category 5 intensity

August 31st, 2022 |

JMA Himawari-8 Visible (0.64 µm) images [click to play animated GIF | MP4]

2.5-minute rapid scan JMA Himawari-8 Visible (0.64 µm) images (above) showed rapidly-intensifying Typhoon Hinnamnor as it once again reached Category 5 intensity (ADT | AiDT | SATCON) about 3 hours after local sunrise on 31 August 2022. Mesovortices rotating within the eye were evident though breaks in patchy high clouds overhead.

2.5-minute Himawari-8 Infrared (10.4 µm) images (below) revealed convection within the eyewall region which exhibited cloud-top infrared brightness temperatures of -80°C and colder (violet pixels).

JMA Himawari-8 Infrared (10.4 µm) images [click to play animated GIF | MP4]

Several hours before sunrise, a toggle between NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images valid at 1749 UTC, viewed using RealEarth (below) revealed concentric mesospheric airglow waves in the DNB image, propagating away from Hinnamnor (primarily to the north of the storm).

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images, valid at 1749 UTC [click to enlarge]

The mesospheric airglow waves were less evident in an earlier comparison of Suomi-NPP VIIRS Day/Night Band and Infrared Window images, valid at 1700 UTC (below) — however, at that time the DNB displayed bright streaks near the eye, indicative of clouds illuminated intense lightning activity.

Suomi-NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images, valid at 1700 UTC [click to enlarge]