Flood wave along the Nueces River in Texas

October 27th, 2018 |

As pointed out by NWS Corpus Christi (above), GOES-16 (GOES-East) Near-Infrared “Vegetation” (0.86 µm) images revealed an interesting flood wave moving along the Nueces River on 27 October 2018 (following a recent period of heavy rainfall).

A toggle between before (10 October) and after (27 October) Aqua MODIS False Color Red-Green-Blue (RGB) images from the MODIS Today site (below) showed dramatic differences between the amount of water (darker shades of blue) flowing along portions of the Nueces River on those 2 days.

Before (10 October) and after (27 October) Aqua MODIS False Color RGB images [click to enlarge]

Before (10 October) and after (27 October) Aqua MODIS False Color RGB images [click to enlarge]

A comparison of Suomi NPP VIIRS Visible (0.64 µm), Near-Infrared Vegetation (0.86 µm) and Near-Infrared Snow/Ice (1.61 µm) images from 27 October (below) demonstrated the improved land/water contrast of the Near-Infrared imagery, which makes it helpful for diagnosing certain types of flooding signatures.

Suomi NPP VIIRS Visible (0.64 µm), Near-Infrared Vegetation (0.86 µm) and Near-Infrared Snow/Ice (1.61 µm) images [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm), Near-Infrared Vegetation (0.86 µm) and Near-Infrared Snow/Ice (1.61 µm) images [click to enlarge]

===== 28 October Update =====

GOES-16 Near-Infrared

GOES-16 Near-Infrared “Vegetation” (0.86 µm) images at 1552 UTC on 27 and 28 October [click to enlarge]

A toggle between GOES-16 Near-Infrared “Vegetation” (0.86 µm) images at 1552 UTC on 27 and 28 October (above) showed the advance of the flood wave during that 24-hour period.

A comparison of Suomi NPP VIIRS Near-Infrared “Vegetation (0.86 µm) and “Snow/Ice” (1.61 µm) images from the early afternoon hours on 27 and 28 October (below) displayed these 24-hour changes at a higher spatial resolution (375 meters, vs 1 km at satellite subpoint with GOES-16). The rear edge of the flood wave (located about 25 miles southeast of Cotulla) appeared to show up a bit better in the 0.86 µm images than the 1.61 µm.

Suomi NPP VIIRS Near-Infrared

Suomi NPP VIIRS Near-Infrared “Vegetation (0.86 µm) and “Snow/Ice” (1.61 µm) images from 27 and 28 October [click to enlarge]

Finally, in a toggle between 250-meter resolution Aqua MODIS False Color RGB images from 27 and 28 October (below), the advance of the leading edge of the flood wave can clearly be seen.

Aqua MODIS False Color RGB images from 27 and 28 October [click to enlarge]

Aqua MODIS False Color RGB images from 27 and 28 October [click to enlarge]

===== 29 October Update =====

GOES-16 Near-Infrared

GOES-16 Near-Infrared “Vegetation” (0.86 µm) images from 1552 UTC on 27, 28 and 29 October [click to enlarge]

GOES-16 Near-Infrared “Vegetation” images from 1552 UTC on 27, 28 and 29 October (above) showed the continued eastward movement of the flood wave down the Nueces River.

Heavy rainfall in Arizona from the remnants of Rosa

October 2nd, 2018 |

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images, 25 September – 02 October [click to play MP4 animation]

Rosa became a Tropical Storm on 25 September 2018, and reached peak intensity as a Category 4 Hurricane on 28 September. As it gradually weakened and made landfall over Baja California on 02 October, its moisture moved across the US Desert Southwest causing heavy rainfall and flash flooding — parts of Arizona received record-setting rainfall (NWS Phoenix | NWS Flagstaff), with precipitation rates as high as 1 inch in 30 minutes in the Phoenix area. GOES-16 (GOES-East) “Clean” Infrared Window (10.3 µm) images during the 8 days from 25 September to 02 October (above) showed the life cycle of Rosa.

A closer look at Rosa during that same time period is shown below. The image interval is 15 minutes, except for 5-minute imagery during a test of Mode 4 scanning strategy on 01 October (from 0000-1550 UTC).

GOES-16 "Clean" Infrared Window (10.3 µm) images, 25 September - 02 October [click to play MP4 animation]

GOES-16 “Clean” Infrared Window (10.3 µm) images, 25 September – 02 October [click to play MP4 animation]

The transport of tropical moisture associated with Rosa could be followed using the MIMIC Total Precipitable Water product (below). The moisture over southwestern Arizona on 02 October was >4 standard deviations above normal for that region and time of year.

MIMIC Total Precipitable Water product, 25 September - 02 October [click to play MP4 animation | MP4]

MIMIC Total Precipitable Water product, 25 September – 02 October [click to play MP4 animation | MP4]

The increase in deep tropical moisture was very evident in plots of rawinsonde data from Tucson, Arizona (below) — Total Precipitable Water peaked at 43.9 mm or 1.73 inches at 12 UTC on 01 October.

Plots of rawinsonde data from Tucson, Arizona 30 September - 02 October [click to enlarge]

Plots of rawinsonde data from Tucson, Arizona 30 September – 02 October [click to enlarge]



Medicane “Zorbas”

September 29th, 2018 |

NOAA-20 and Suomi NPP VIIRS Day/Night Band (0.7 µm) images [click to enlarge]

NOAA-20 and Suomi NPP VIIRS Day/Night Band (0.7 µm) images [click to enlarge]

Medicane “Zorbas” — as named by Freie Universität Berlin (surface analyses) — developed in the Mediterranean Sea late in the day on 27 September 2018. A toggle between VIIRS Day/Night Band (0.7 µm) images from NOAA-20 and Suomi NPP (above; courtesy of William Straka, CIMSS) revealed the well-defined circulation of the storm a few hours after Midnight local time on 28 September. Note the bright streak north of the storm center on the NOAA-20 image — this was an area of clouds illuminated by intense lightning activity. Other less prominent lightning streaks were evident in thunderstorms farther to the east over the Mediterranean Sea. On the Suomi NPP image, a small bright spot could be seen, evidence of minor volcanic activity at Mount Etna on the island of Sicily, as well as the hazy signature of a plume of blowing dust/sand that was moving northward off the coast of Libya. The corresponding VIIRS Infrared images are available here.

During the following daylight hours of 28 September, EUMETSAT Meteosat-11 High Resolution Visible (0.8 µm) images (below) showed the storm as it became better organized and increased intensity. Another dense plume of blowing dust/sand began to move off the coast of Libya late in the day.

Meteosat-11 Visible (0.8 µm) images, with hourly plots of wind barbs (yellow) and wind gusts (red) [click to play animation | MP4]

Meteosat-11 Visible (0.8 µm) images, with hourly plots of wind barbs (yellow) and wind gusts (red) [click to play animation | MP4]

On 29 September, Meteosat-11 Visible (0.8 µm) images (below) showed the Medicane moving inland along the Peloponnese coast of southern Greece — shortly after the storm center passed, winds gusted to 48 knots at Kalamata at 1220 UTC (while a heavy thunderstorm was being reported).

Meteosat-11 Visible (0.8 µm) images, with hourly plots of winds (yellow) and gusts in knots (red) [click to play animation | MP4]

Meteosat-11 Visible (0.8 µm) images, with hourly plots of wind barbs (yellow) and gusts in knots (red) [click to play animation | MP4]

A sequence of Terra and Aqua MODIS True Color Red-Green-Blue (RGB) images from 28 and 29 September from RealEarth (below) showed another view of the Zorbas on those 2 days (the valid time of the Terra MODIS image showing the eye-like feature on 29 September was 0911 UTC). Sea Surface Temperatures were near 25ºC in the central Mediterranean Sea where Zorbas was intensifying.

Terra/Aqua MODIS True Color RGB images on 28 and 29 September [click to enlarge]

Terra/Aqua MODIS True Color RGB images on 28 and 29 September [click to enlarge]

Hourly images of the MIMIC Total Precipitable Water product (below) showed moisture associated with the storm, which produced heavy rainfall and flash flooding in parts of southern Greece — the NESDIS Blended TPW Anomaly product indicated that this moisture was as much as 200% of normal for the region and date. Additional information and videos can be found here.

MIMIC morphed Total Precipitable Water images, 27-29 September [click to play animation | MP4]

MIMIC morphed Total Precipitable Water images, 27-29 September [click to play animation | MP4]

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]