Florence produces record rainfall in North Carolina and South Carolina

September 17th, 2018 |

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images, with hourly precipitation type symbols plotted in yellow and SPC storm reports plotted in cyan, 13-17 September [click to play MP4 animation]

After Hurricane Florence made landfall in North Carolina during the morning hours on 14 September, it moved very slowly (at times only 2-3 mph) southwestward into South Carolina during 15-16 September (surface analyses). Prolonged heavy rainfall resulted (WPC summary), with new state records (see below) for precipitation from a tropical cyclone being set in North Carolina (35.93 inches) and South Carolina (23.63 inches). GOES-16 (GOES-East) “Clean” Infrared Window (10.3 µm) images every 5 minutes during the 4-day period of 13-16 September (above) showed the evolution of banding and the development of new convection that produced the heavy rainfall — widespread flooding along with strong winds caused power outages across portions of the 2 states (NC | SC), and closed sections of Interstates 95 and 40. Note that the power outages caused extended dropouts of the plotted surface reports — especially in eastern North Carolina; reports were missing when the gray 4-letter station identifiers disappeared — even though many of those sites were likely experiencing heavy rainfall during those dropout times.

Florence also spawned a few tornadoes on 14, 15 and 16 September — SPC storm reports are plotted in cyan on the GOES-16 Infrared images.

Hourly images of the MIMIC Total Precipitable Water product (below) showed tropical moisture associated with Florence as it moved inland during the 13-17 September period.

MIMIC Total Precipitable Water product [click to play animation | MP4]

MIMIC Total Precipitable Water product, 13-17 September [click to play animation | MP4]

Animations of plots of rawinsonde data from the coastal sites of Newport/Morehead City, North Carolina and Charleston, South Carolina (below) revealed the increase in deep tropical moisture from 13-16 September — Total Precipitable Water values were as high as 68.6 mm (2.70 inches) at Newport and 67.8 mm (2.67 inches) at Charleston.

Daily plots of rawinsonde data from Newport/Morehead City, North Carolina [click to enlarge]

Daily plots of rawinsonde data from Newport/Morehead City, North Carolina [click to enlarge]

Daily plots of rawinsonde data from Charleston, South Carolina [click to enlarge]

Daily plots of rawinsonde data from Charleston, South Carolina [click to enlarge]

As the remnants of Florence moved from Kentucky to West Virginia during the daylight hours of 17 September, numerous tornadoes occurred in central Virginia (SPC storm reports | NWS Wakefield summary). 1-minute GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images (below) showed the development of thunderstorms which produced these tornadoes.

GOES-16 "Red" Visible (0.64 µm, left) and "Clean" Infrared Window (10.3 µm, right) images, with plots of SPC storm reports [click to play MP4 animation]

GOES-16 “Red” Visible (0.64 µm, left) and “Clean” Infrared Window (10.3 µm, right) images, with plots of SPC storm reports [click to play MP4 animation]

===== 18 September Update =====

Before/after (26 August/18 September) Terra MODIS False Color RGB images [click to enlarge]

Terra MODIS False Color RGB images, 26 August vs. 18 September [click to enlarge]

A comparison of before/after (26 August/18 September) Terra MODIS False Color Red-Green-Blue (RGB) images from the MODIS Today site (above) showed areas of inland flooding (increasing water coverage appears as darker shades of blue) in the wake of Florence across far southeastern North Carolina and far northeastern South Carolina.

Looking slightly to the south, a similar before/after comparison of Terra MODIS True Color RGB images (below) revealed areas of sediment runoff into the Atlantic Ocean.

Terra MODIS True Color RGB images, 26 August vs. 18 September [click to enlarge]

Terra MODIS True Color RGB images, 26 August vs. 18 September [click to enlarge]

Hurricane Florence makes landfall in North Carolina

September 14th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with hourly plots of surface wind gusts in knots [click to play MP4 animation]

Hurricane Florence made landfall near Wrightsville Beach, North Carolina at 1115 UTC (7:15 am EDT) with estimated maximum winds of 78 knots (90 mph) and a minimum central pressure estimate of 958 hPa (28.29″). Overlapping GOES-16 (GOES-East) Mesoscale Domain Sectors provided images every 30 seconds — “Red” Visible (0.64 µm) images (above) and “Clean” Infrared Window (10.3 µm) images (below) showed the storm as it slowly moved inland after sunrise. A peak wind gust of 105 mph was recorded at Wilmington NC (which is located at the center of the GOES-16 images); in northeastern North Carolina, winds gusted to 105 mph at Fort Macon and 112 mph at the New River Inlet Buoy.

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images, with hourly plots of wind gusts [click to play MP4 animation]

The MIMIC Total Precipitable Water product (below) showed abundant moisture associated with Florence moving inland during the 48-hour period ending at 23 UTC on 14 September.

MIMIC Total Precipitable Water product [click to play animation | MP4]

MIMIC Total Precipitable Water product [click to play animation | MP4]

Toggles between Visible and Infrared Window images from Terra/Aqua MODIS and Suomi NPP VIIRS are shown below.

Terra MODIS Visible (0.65 µm) and Infrared Window (11.0 µm) images [click to enlarge]

Terra MODIS Visible (0.65 µm) and Infrared Window (11.0 µm) images at 1620 UTC [click to enlarge]

Aqua MODIS Visible (0.65 µm) and Infrared Window (11.0 µm) images [click to enlarge]

Aqua MODIS Visible (0.65 µm) and Infrared Window (11.0 µm) images at 1801 UTC [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images at 1835 UTC [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images at 1835 UTC [click to enlarge]

Over the western Atlantic Ocean, strong winds associated with Florence created large waves which induced upwelling of colder water from below the ocean surface, as seen in Ocean Heat Content data (below).

Ocean Heat Content data from 14 September [click to enlarge]

Ocean Heat Content data from 14 September [click to enlarge]

Super Typhoon Mangkhut makes landfall in the Philippines

September 14th, 2018 |

Himawari-8 Infrared Window (10.4 µm) images [click to play MP4 animation]

Himawari-8 Infrared Window (10.4 µm) images [click to play MP4 animation | Animated GIF]

Himawari-8 Infrared Window (10.4 µm) images (above) showed Super Typhoon Mangkhut making landfall as a Category 5 intensity storm over the far northern portion of Luzon in the Philippines just after 17 UTC on 14 September 2018 (1 am local time on 15 September). The eye quickly deteriorated and became cloud-filled after moving inland.

The MIMIC-TC morphed microwave product (below) indicated that Mangkhut was in the process of completing an eyewall replacement cycle shortly before making landfall.

westernMIMIC-TC morphed microwave product [click to enlarge]Mangkhut moved over waters of the western Philippine Sea having high values of Ocean Heat Content and Sea Surface Temperature during the final day preceding landfall (below).

Ocean Heat Content and Sea Surface Temperature data along the path of Mangkhut [click to enlarge]

Hurricane Florence continues to approach the southeastern US

September 11th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) images [click to play MP4 animation]

Hurricane Florence maintained Category 4 intensity on the morning of 11 September 2018 — and 1-minute (initially 30-second, until 1345 UTC) Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) and “Clean” Infrared Window (10.3 µm) images (below) showed improving eye structure after the tropical cyclone completed an eyewall replacement cycle during the preceding nighttime hours (MIMIC TC). A distinct pattern of transverse banding was also evident within the northern semicircle of Florence on Infrared imagery.

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images [click to play MP4 animation]

DMSP-18 SSMIS Microwave (85 GHz) imagery from the CIMSS Tropical Cyclones site (below) showed a large eye at 1015 UTC, and also at 1103 UTC.

DMSP-18 SSMIS Microwave (85 GHz) and GOES-16

DMSP-18 SSMIS Microwave (85 GHz) and GOES-16 “Clean” Infrared Window (10.3 µm) images at 1015 UTC [click to enlarge]

GOES-16 Upper-level Water Vapor (6.2 µm) images with Derived Motion Winds (below) revealed that a well-defined high altitude outflow channel had developed northwest of Florence, helping the storm to maintain its intensity.

GOES-16 Upper-level Water Vapor (6.2 µm) images, with Derived Motion Winds [click to play MP4 animation]

GOES-16 Upper-level Water Vapor (6.2 µm) images, with Derived Motion Winds [click to play MP4 animation]

1-minute GOES-16 True Color Red-Green-Blue (RGB) images (courtesy of Kathy Strabala, CIMSS; details) are shown below. A larger-scale RGB animation beginning at sunrise is available here (courtesy of Rick Kohrs, SSEC).

GOES-16 natural color RGB images [click to play MP4 animation]

1-minute GOES-16 True Color RGB images, 1330-1440 UTC [click to play MP4 animation]

Taking a closer look at the center of Florence later in the day, 1-minute GOES-16 data (below) showed mesovortices within the eye on Visible imagery, along with a narrow radial band of colder (darker red) cloud-top infrared brightness temperatures about 30-50 miles from the inner edge of the eyewall.

GOES-16

GOES-16 “Red” Viisible (0.64 µm) images [click to play MP4 animation]

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images [click to play MP4 animation]

===== 12 September Update =====

Florence remained at Category 4 intensity early in the day as it continued its northwestward motion toward the southeast coast of the US on 12 September. A 20-hour period of 1-minute GOES-16 Infrared images (from 0000-2015 UTC) is shown below.

1-minute GOES-16

1-minute GOES-16 “Clean” Infrared Window (10.3 µm) images, from 0000-2015 UTC [click to play MP4 animation]

Nighttime toggles between VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 are shown below (courtesy of William Straka, CIMSS). Bright lightning-illuminated cloud areas can be seen on the DNB images distant to the north and northwest of the storm center; with minimal illumination from the Moon (which was in the Waxing Crescent phase, at only 10% of Full), Florence was illuminated primarily via airglow. On the Infrared images, a coarse pattern of transverse banding was evident along the far southern and western periphery of the storm.

Suomi NPP VIIRS Day/Night Band and Infrared Window images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

NOAA-20 VIIRS Day/Night Band and Infrared Window images [click to enlarge]

NOOA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

A sequence of Terra/Aqua MODIS and Suomi NPP VIIRS Infrared images (below) showed dramatic changes in the cold central dense overcast (CDO) of Florence between 02 and 18 UTC.

Infrared Window images from Terra MODIS (11.0 µm) and Suomi NPP VIIRS (11.45 µm) [click to enlarge]

Infrared Window images from Terra MODIS (11.0 µm) and Suomi NPP VIIRS (11.45 µm) [click to enlarge]

During the morning hours, 1-minute GOES-16 Visible and Infrared images (below) once again displayed a distinct eye and eyewall structure, with surface mesovortices evident within the eye. A curious linear standing wave — extending radially outward to the northeast of the storm center — developed from about 13-15 UTC (best seen on Infrared images).

GOES-16

GOES-16 “Red” Visible (0.64 µm) images [click to play MP4 animation]

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images [click to play MP4 animation]

ASCAT surface scatterometer winds from Metop-A (below) were as strong as 76 knots just northeast of the eye at 1450 UTC.

GOES-16

GOES-16 “Red” Visible (0.64 µm) image with Metop-A ASCAT surface scatterometer winds [click to enlarge]

A stereoscopic animation using GOES-16 and GOES-17 imagery is shown below — to view in three dimensions, cross your eyes until 3 equal images are apparent, then focus on the image in the center. *Note: GOES-17 images shown here are preliminary and non-operational*

Stereoscopic animation using GOES-16 and GOES-17

Stereoscopic animation using GOES-16 and GOES-17 “Red” Visible (0.64 µm) imagery [click to play animation]

During the afternoon hours, GOES-16 Visible and Infrared images (below) showed that the eye presentation  was beginning to deteriorate as Florence weakened to Category 3 intensity by 21 UTC.

GOES-16

GOES-16 “Red” Visible (0.64 µm) images [click to play MP4 animation]

GOES-16

GOES-16 “Clean” Infrared Window {10.3 µm) images [click to play MP4 animation]

The MIMIC Total Precipitable Water product (below) indicated that high TPW values associated with Florence began to move inland along the US East Coast by the end of the day.

MIMIC Total Precipitable Water product [click to enlarge]

MIMIC Total Precipitable Water product [click to enlarge]