Hurricane Matthew: heavy rainfall and flooding across the Southeast and Mid-Atlantic US

October 9th, 2016 |

MIMIC Total Precipitable Water product, from 06 October/04 UTC to 08 October/16 UTC [click to play MP4 animation]

MIMIC Total Precipitable Water product, from 06 October/04 UTC to 08 October/16 UTC [click to play MP4 animation]

Copious amounts of moisture associated with Hurricane Matthew resulted in heavy rainfall (map | text list) and widespread flooding across the Southeast and Mid-Atlantic US during the 07 October to 09 October 2016 period. Hourly images of the MIMIC Total Precipitable Water (TPW) product (above; also available as a 22 Mbyte animated GIF) showed the high TPW values that spread from Florida to the Mid-Atlantic states; all-time record high TPW values were measured via rawinsonde at Jacksonville, Florida and Charleston, South Carolina, with a record high value for the month of October at Newport/Cape Hatteras, North Carolina (Tweet). For more details, see the Weather Underground blog.

Track of Matthew, from 28 September at 12 UTC to 09 October at 18 UTC

Track of Matthew, from 28 September at 12 UTC to 09 October at 18 UTC

Matthew set numerous records for intensity, longevity, and landfall (summary) — an animation of hourly GOES-13 Water Vapor (6.5 µm) images covering the 11-day period from 12 UTC on 28 September to 12 UTC on 09 October is shown below (also available as a large 113 Mbyte animated GIF). The CIMSS Tropical Cyclones site posted GOES-13 Visible (0.63 µm) animations from the individual days of 03 October, 04 October, 05 October, 06 October, 07 October, and 08 October.

GOES-13 Water Vapor (6.5 µm) images [click to play MP4 animation]

GOES-13 Water Vapor (6.5 µm) images [click to play MP4 animation]

The combination of high winds and flooding led to widespread power outages, with over 2 million homes and businesses without power. A comparison of nighttime Suomi NPP VIIRS Day/Night Band (0.7 µm) images from 28 September (before Mattthew arrived) and 09/10 October (after the passage of Matthew) showed a notable reduction in the glow of city lights in areas with no power (below; images courtesy of William Straka, SSEC). Note that the presence of patchy clouds on all 3 images tended to diffuse or even obscure the appearance of city lights below, depending on the thickness of the cloud layer(s).

Suomi NPP VIIRS Day/Night Band (0.7 µm) images on 28 September, 09 October and 10 October [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) images on 28 September, 09 October and 10 October [click to enlarge]

As clouds cleared in the wake of Hurricane Matthew on 09 October, a Suomi NPP VIIRS true-color Red/Green/Blue (RGB) image at 1859 UTC, viewed using RealEarth (below), revealed patterns of turbidity in the offshore waters of the Atlantic Ocean from Florida to North Carolina; this increased turbidity was a result of high amounts of particles suspended in the water due to a combination of mixing from prolonged high winds and runoff from inland flooding.

Suomi NPP VIIRS true-color image [click to enlarge]

Suomi NPP VIIRS true-color image [click to enlarge]

About 8 hours later, a Terra MODIS Sea Surface Temperature (SST) product image at 0243 UTC on 10 October (below) showed a large eddy of warm Gulf Stream water (with a maximum SST value of 85.2º F, darker red color enhancement) surrounding a pocket of cooler water (with a minimum SST value of 78.5º F, darker blue color enhancement) off the coast of South Carolina.

Terra MODIS Sea Surface Temperature product [click to enlarge]

Terra MODIS Sea Surface Temperature product [click to enlarge]

The VIIRS Instrument on Suomi NPP provides data that are used in a River Flood Product (discussed previously on this blog). The product uses three reflective bands (I01, I02, and I03 at 0.64 µm, 0.86 µm and 1.61 µm, respectively) and the infrared window band I05 at 11.45 µm. The image below (courtesy of Sanmei Li at George Mason University) identifies many flooded regions over North Carolina. In particular, the flooding near Goldsboro and Lumberton is identified.

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JPSS River Flood product produced with Suomi NPP data, 1817 UTC on 11 October 2016 (Click to enlarge)

A sequence of 1 pre-Matthew (06 September) and 3 post-Matthew (09, 10 and 12 October) Terra/Aqua MODIS false-color RGB images from the SSEC MODIS Today site (below) also helped to highlight areas of flooding (darker shades of blue, especially notable along river valleys) that resulted from the heavy rainfall.

Terra and Aqua MODIS false-color images, from 06 September and 09, 10 and 12 October 2016 [click to enlarge]

Terra and Aqua MODIS false-color images, from 06 September and 09, 10 and 12 October 2016 [click to enlarge]

Matthew along the east coast of Florida

October 7th, 2016 |

GOES-13 Visible (0.63 µm) Imagery, 1230-1337 UTC (Click to enlarge)

Hurricane Matthew is on a path that parallels the coast of Florida, with the center remaining just offshore. GOES-13 Visible imagery from a 1-hour time period this morning, above, shows the continued development of convection around the eyewall and the motion of convective bands inland. GOES-13 Visible images with hourly surface winds and wind gusts (in knots) are shown below. The highest wind gust recorded along the central Florida coast was 107 mph (NWS Melbourne PNS).

GOES-13 Visible (0.63 um) images, with hourly surface winds and gusts in knots [Click to play animation]

GOES-13 Visible (0.63 um) images, with hourly surface winds and gusts in knots [Click to play animation]

A 24-hour animation of morphed Microwave imagery (from this site), below, suggests that an eyewall replacement cycle has completed: the very small eye present at storm’s center at the start of the animation has been replaced by a larger-diameter eye at the end of the animation. Storm strength typically drops during eyewall replacements. Note also that the microwave data shows that the strongest convection remained offshore.

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Morphed Microwave Imagery of Matthew showing Strongest Convection, 1200 UTC 06 October to 1100 UTC 07 October 2016 (Click to enlarge)

Infrared imagery from GOES-13, below, also shows the coldest cloud tops to the east of the eye (indicated by the arrow in the image).

GOES-13 Infrared (10.7 µm) Imagery, 1355 UTC. The flashing arrow points to Matthew’s eye (Click to enlarge)

A longer animation of GOES-13 Infrared Window (10.7 um) images with hourly surface winds and wind gusts (in knots) is shown below (MP4 | animated GIF).

GOES-13 Infrared Window (10.7 um) images [Click to play animation]

GOES-13 Infrared Window (10.7 um) images [Click to play animation]

A toggle between Suomi NPP VIIRS Visible (0.64 um) and Infrared Window (11.45 um) images at 1751 UTC is shown below; Matthew was a Category 3 hurricane at that time.

Suomi NPP VIIRS Visible (0.64 um) and Infrared Window (11.45 um) images [Click to enlarge]

Suomi NPP VIIRS Visible (0.64 um) and Infrared Window (11.45 um) images [Click to enlarge]

Hurricane Matthew southeast of Florida

October 6th, 2016 |

GOES-13 Infrared Window Channel (10.7 µm) Imagery, 0345, 0745 and 1145 UTC (Click to enlarge)

Hurricane Matthew moved through the Bahamas overnight, slowly organizing and strengthening to Category 4 intensity after its interaction with the high terrain of the Greater Antilles (Note that Day/Night Band Imagery from overnight on 6 October — from this Blog Post — shows that city lights are back on in Port-au-Prince Haiti as recovery proceeds in that country). The three images above show the evolution of the storm from 0345 UTC to 1145 UTC on 6 October. A warm eye is present, but it is not a cloud-free eye.

The GOES-13 satellite continued to be in Rapid Scan Operations (RSO) mode, providing images as frequently as every 5-7 minutes. An animation of Infrared Window (10.7 µm) imagery is shown below (MP4 | animated GIF). Nassau, Bahamas (station identifier MYNN) experienced a wind gust of 74 knots at 13 UTC.

GOES-13 Infrared Window (10.7 µm) imagery [Click to play animation]

GOES-13 Infrared Window (10.7 µm) imagery [Click to play animation]

A higher-resolution view of the eye was provided by a Suomi NPP VIIRS Infrared Window (11.45 µm) image at 0645 UTC, below.

Suomi NPP VIIRS Infrared Window (11.45 µm) image [Click to enlarge]

Suomi NPP VIIRS Infrared Window (11.45 µm) image [Click to enlarge]

GOES-13 Visible Imagery from early in the morning on 6 October, below (MP4 | animated GIF), confirms the diagnosis of a cloudy eye. The center of the storm is moving northwestward between Andros Island to the west and New Providence Island to the east (Nassau, the capitol of the Bahamas, is on New Providence Island).

GOES-13 Visible (0.63 µm) Imagery, 1145-2015 UTC (Click to animate)

Matthew is forecast to reach the coast of Florida within 24 hours. For the latest information, consult the website of the National Hurricane Center. Additional information is available here.

Hurricane Matthew moves into the Bahamas

October 5th, 2016 |
morphedmw_matthew_last48hrs_ending5oct_1000

Morphed Microwave Imagery showing the eye of Matthew from 1400 UTC 3 October through 1345 UTC 5 October (Click to enlarge)

The animation of Matthew, above, from morphed microwave imagery (from this site), shows the toll that interaction with the high terrain of Hispaniola and eastern Cuba has had on the storm (causing it to be downgraded from Category 4 to Category 3 intensity). The formerly distinct eye had eroded, although eye re-formation occurs at the end of the animation. Once again, a comparison of microwave vs infrared imagery revealed that the well-defined eye structure was much more apparent using microwave data. Strengthening/Re-organization of Matthew in the near term will be governed by Sea Surface Temperatures (that are warm) and wind shear (shown below, from this site, that is weak).

wg8shr_0900_5october2016

Diagnosed wind shear, 0900 UTC on 5 October 2016 (Click to enlarge)

Total Precipitable Water fields (from this site, using data from here), below, show abundant moisture surrounding Matthew at its present position. There is dry air over the eastern United States landmass, however.

Morphed Total Precipitable water from MIRS, 1300 UTC 4 October – 1200 UTC 5 October (Click to enlarge)

Morphed Total Precipitable water from MIRS, 1300 UTC 4 October – 1200 UTC 5 October (Click to enlarge)

During the morning and afternoon hours, the satellite presentation of Matthew began to slowly improve on GOES-13 Visible (0.63 µm) and Infrared Window (10.7 µm) imagery, below (MP4 | animated GIF), with well-defined convective bursts seen later in the day. Note: the noise seen on the 1645 UTC images was due to solar RFI.

GOES-13 0.63 µm Visible (left) and 10.7 µm Infrared Window (right) images [Click to play animation]

GOES-13 0.63 µm Visible (left) and 10.7 µm Infrared Window (right) images [Click to play animation]