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.

snppviirs_floodmap_south_north_carolina_usa_11oct_2016_18_17

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]

Hurricane Hermine

September 1st, 2016

GOES-13 Visible (0.63 µm) images, with surface/buoy/ship reports plotted in yellow [click to play animation]

GOES-13 Visible (0.63 µm) images, with surface/buoy/ship reports plotted in yellow [click to play animation]

Hermine was upgraded to a Hurricane over the Gulf of Mexico around 20 UTC on 01 September 2016. GOES-13 (GOES-East) Visible (0.63 µm) images (above) showed improvement in the appearance of curved banding structures around the eye late in the day. The GOES-13 satellite had been placed into Rapid Scan Operations (RSO) mode, providing images as frequently as every 5-7 minutes. Note that Hurricane Hermine developed from Tropical Invest 99L, which was sampled by 1-minute GOES-14 imagery beginning on 25 August; unfortunately, the 1-minute Super Rapid Scan Operations for GOES-R (SRSO-R) test period ended at 1115 UTC on 29 August (however, imaging of the evolution of Tropical Depression 9 to Hurricane Hermine continued at 15-minute intervals).

The corresponding GOES-13 Infrared Window (10.7 µm) images (below) revealed the eventual formation of a distinct eye, with bursts of convection exhibiting cloud-top IR brightness temperatures in the -75º to -80º C range (shades of white to violet pixels) in the western and southern semicircles of the eyewall region. Hermine became the first hurricane to make landfall in Florida since Wilma in 2005.

GOES-13 Infrared Window (10.7 µm) images, with surface/buoy/ship reports plotted in yellow [click to play animation]

GOES-13 Infrared Window (10.7 µm) images, with surface/buoy/ship reports plotted in yellow [click to play animation]

A Suomi NPP VIIRS true-color Red/Green/Blue (RGB) image visualized using RealEarth (below) provided a detailed view of the curved banding around the western and southern portion of the eye.

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

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

A comparison of DMSP-17 SSMIS Microwave (85 GHz) and GOES-13 Infrared Window (10.7 µm) images around 2315 UTC (below) depicted a much larger eye presentation on microwave vs infrared — the microwave image showed the curved banding structure around an eye that was still not well-organized.

DMSP-17 SSMIS Microwave (85 GHz) and GOES-13 Infrared Window (10.7 µm) images [click to enlarge]

DMSP-17 SSMIS Microwave (85 GHz) and GOES-13 Infrared Window (10.7 µm) images [click to enlarge]

While Hermine passed over waters exhibiting warm Sea Surface Temperature values in the eastern Gulf of Mexico, the Ocean Heat Content values were only modest (below).

Sea Surface Temperature and Ocean Heat Content values [click to enlarge]

Sea Surface Temperature and Ocean Heat Content values [click to enlarge]

The high values of Total Precipitable Water (TPW) associated with Hermine were evident on hourly composites of morphed TPW from MIRS sensors (below). Rainfall amounts exceeded 22 inches in Florida (WPC storm summary)

Morphed Total Precipitable Water derived from MIRS sensors [click to play animation]

Morphed Total Precipitable Water derived from MIRS sensors [click to play animation]


===== Post-landfall Update, 02 September =====
 

Suomi-NPP overflew Hermine shortly after 0700 UTC on 02 September, after its 0530 UTC landfall near St. Mars FL. The toggle below shows the VIIRS 0.7 µm Day/Night Band and the 11.45 µm Infrared Window imagery. Both show the asymmetric nature of the storm. Rain and clouds extend quite a distance to the south and east of the storm, but not far to the west. The infrared imagery shows cold cloud tops surrounding the storm center southeast of Tallahassee, with very cold cloud tops also over Tampa FL and near Savannah GA with bands associated with the storm. Cloud detail is missing in the Day/Night Band image because of the lack of lunar illumination — a New Moon occurred early on 01 September — however, high-altitude mesospheric airglow waves (references: 1 | 2 | 3) can be seen off the east coast of Florida and Georgia, excited by Hermine’s bands of strong thunderstorms.

Suomi NPP Day/Night Band Visible (0.70 µm) and Infrared Window (11.45 µm) images at 0723 UTC on 2 September [click to enlarge]

Suomi NPP Day/Night Band Visible (0.70 µm) and Infrared Window (11.45 µm) images at 0723 UTC on 2 September [click to enlarge]

A toggle between before-landfall (0319 UTC Terra MODIS) and after-landfall (0814 UTC POES AVHRR) Infrared images, below, shows the expected trend of warming cloud-top IR brightness temperatures and a consolidation into a more compact storm circulation.

11.0 µm Terra MODIS (0319 UTC) and 12.0 µm POES AVHRR (0814 UTC) Infrared images [click to enlarge]

11.0 µm Terra MODIS (0319 UTC) and 12.0 µm POES AVHRR (0814 UTC) Infrared images [click to enlarge]

===== 03 September Update =====

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

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

A toggle between Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 0707 UTC on 03 September (above; courtesy of William Straka, SSEC) showed that Hermine — still being classified as a Tropical Storm — continued to produce mesospheric airglow waves as it moved off the East Coast of the US. Numerous bright white streaks were also evident on the Day/Night Band image, due to cloud illumination from intense lightning activity.

During the following daylight hours of 03 September, GOES-13 (GOES-East) Visible (0.63 µm) images (below: also available as an MP4 animation) showed the circulation of post-tropical cyclone Hermine. In eastern North Carolina, winds gusts as high as 80 mph were recorded, with rainfall amounts as great as 8.54 inches (NWS Newport/Morehead City); the storm also produced a few tornadoes (SPC Storm Reports). In southeastern Virginia, winds gusted to 73 mph (NWS Wakefield). A few of the heavier rainfall amounts for individual states are listed here.

GOES-13 Visible (0.63 µm) images, with surface and buoy wind barbs plotted in yellow and wind gusts (knots) plotted in red [click to play animation]

GOES-13 Visible (0.63 µm) images, with surface and buoy wind barbs plotted in yellow and wind gusts (knots) plotted in red [click to play animation]

A Suomi NPP VIIRS true-color image visualized using RealEarth (below) showed the clouds associated with Hermine at 1827 UTC.

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

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

Detection of River Flooding in Alaska

August 31st, 2016
Google Maps of west central Alaska, the JPSS River Flood Product and Landsat-8 False Color Imagery, 30 August 2016 [click to enlarge]

Google Maps of west central Alaska, the JPSS River Flood Product and Landsat-8 False Color Imagery, 30 August 2016 [click to enlarge]

Swampy conditions near the meandering Innoko River, a tributary to the Yukon River in Alaska, have been diagnosed by the JPSS River Flood Product near the Innoko’s mouth on the Yukon. (August has been very wet over parts of Alaska) A timely Landsat-8 overpass, in clear skies, on 30 August 2016 allows for excellent validation of the Flood Product. The animation above (using Images from RealEarth) cycles between the Google Maps terrain and satellite views of the region, the JPSS Flood Product (developed by a group led by Sanmei Li at George Mason University, which product uses reflective channels on JPSS (I01, I02, and I03, 0.64 µm, 0.86 µm and 1.61 µm, respectively) and I05, the 11.45 µm channel) and the Landsat-8 False Color overpass. Diagnosed floods in the JPSS Product are distinctly captured in the Landsat-8 False Color product.

Flooding in Louisiana

August 12th, 2016

Morphed MIRS observations of total precipitable water (TPW), 1500 UTC 11 August - 2100 UTC 12 August [click to play animation]

Morphed MIRS observations of total precipitable water (TPW), 1500 UTC 11 August – 2100 UTC 12 August [click to play animation]

Persistent convection in an atmosphere rich in moisture has led to life-threatening flooding over many Parishes in southern Louisiana. The animation above, taken from images at this site that morphs MIRS estimates of Total Precipitable Water (with values valid over both land and water) shows values around three inches over much of southeastern Louisiana. These TPW values agree with in situ observations such as the radiosonde from New Orleans at 1200 UTC on 12 August, where 2.70″ was observed. 24-hour rainfall totals ending at 1200 UTC on 12 August (Link) show a widespread region of more than 6″; raingauge observations of 6-hour totals at 1200 and 1800 UTC, below, show that the rain continued into the day on 12 August.

GOES-14 Visible (0.62 µm) images, with METAR observations of 6-hour precipitation, 1200 and 1800 UTC on 12 August 2016 [click to enlarge]

GOES-14 Visible (0.62 µm) images, with METAR observations of 6-hour precipitation, 1200 and 1800 UTC on 12 August 2016 [click to enlarge]

The flood-producing thunderstorms were very slow-moving, as evidenced in the animation of Infrared Window (10.7 µm) images from GOES-14, below (GOES-14 is in SRSO-R mode this month). Very little motion occurs in the two hours of this loop (using images at 5-minute time steps).

GOES-14 Infrared Window (10.7 µm) Imagery, 1625-1830 UTC on 12 August 2016 [click to play animation]

GOES-14 Infrared Window (10.7 µm) Imagery, 1625-1830 UTC on 12 August 2016 [click to play animation]

The entire sequence of 1-minute interval GOES-14 Infrared Window (10.7 µm) images from 0001-2358 UTC on 12 August is shown below.

GOES-14 Infrared Window (10.7 µm) images, with surface weather symbols plotted in yellow [click to play MP4 animation]

GOES-14 Infrared Window (10.7 µm) images, with surface weather symbols plotted in yellow [click to play MP4 animation]

This event is also discussed at the Satellite Liaison Blog, where the focus is on 1-minute visible imagery from GOES-14 and 1-minute lightning data.

===== 13 August Update =====

GOES-14 Infrared Window (10.7 µm) images, with hourly surface weather symbols plotted in yellow [click to play MP4 animation]

GOES-14 Infrared Window (10.7 µm) images, with hourly surface weather symbols plotted in yellow [click to play MP4 animation]

The heavy rainfall continued into 13 August, with storm total accumulations exceeding 31 inches in Louisiana (WPC storm summary). The entire sequence of 1-minute interval GOES-14 Infrared Window (10.7 µm) images spanning the period 1115 UTC on 11 August to 2159 UTC on 13 August, above, shows the development of multiple clusters of slow-moving thunderstorms, some of which exhibited cloud-top IR brightness temperatures of -80ºC or colder (violet color enhancement).