Heavy rainfall over the Hawaiian island of Kauai

April 15th, 2018 |

GOES-15 Water Vapor (6.5 µm, left) and Infrared Window (10.7 µm, right) images, with hourly plots of surface reports [click to play MP4 animation]

GOES-15 Water Vapor (6.5 µm, left) and Infrared Window (10.7 µm, right) images, with hourly plots of surface reports [click to play MP4 animation]

A series of back-building thunderstorms produced very heavy rainfall and flash flooding (Public Information Statement | Local Storm Reports) over the northern and eastern portion of Kauai on 14-15 April 2018. GOES-15 (GOES-West) Water Vapor (6.5 µm) and Infrared Window (10.7 µm) images (above) showed these deep convective storms, which exhibited cloud-top infrared brightness temperatures in the -60 to -70 ºC range (red to black enhancement).

Even though the JMA Himawari-8 AHI instrument provides more frequent Water Vapor and Infrared Window images (every 10 minutes, compared to every 15-30 minutes with GOES-15) at a higher spatial resolution (2-km at satellite sub-point, vs 4-km with GOES-15),  Hawai’i is located near the limb of the Himawari-8 view — so parallax was playing a major role in the apparent location of the important convective features. Note how the primary thunderstorms were displayed to the east of Kauai on the Himawari-8 images, in contrast to directly over the island on GOES-15 images.

Himawari-8 Water Vapor (6.9 µm, left) and Infrared Window (10.4 µm, right) images, with hourly plots of surface reports [click to play MP4 animation]

Himawari-8 Water Vapor (6.9 µm, left) and Infrared Window (10.4 µm, right) images, with hourly plots of surface reports [click to play MP4 animation]

The MIMIC Total Precipitable Water product (below) showed that high amounts of tropical moisture were drawn northward across Hawai’i by the circulation of an upper-level trough that was situated west of the islands.

MIMIC Total Precipitable Water product [click to play animation]

MIMIC Total Precipitable Water product [click to play animation]

Flooding in the Midwest and lower Ohio River Valley

February 26th, 2018 |

GOES-16 0.86 µm “Veggie” Band Imagery at 1902 UTC on 12 and 26 February 2018 (Click to enlarge)

Solar radiation at 0.86 µm is strongly absorbed by water on the surface, but reflected by land. There is therefore a big contrast in GOES-16 “Veggie” Band imagery between rivers and adjacent land, and that contrast difference can easily identify regions of inundation. The toggle above compares imagery from 26 February 2018 and from 12 February 2018 over the lower Ohio River Valley. Significant widening of many waterways is apparent in the 0.86 µm imagery on 26 February, especially over southern Indiana, a result of both snow melt and abundant precipitation in the past 7 days, shown below (from this link). This has caused many stream gauges to show Moderate (Red gauges) to Major (Purple Gauges) flooding (image from this link), also shown below.  A zoomed-in image over northern Indiana, at bottom, shows the major flooding along the Kankakee River.

Observed precipitation for the 7 days ending at 1200 UTC on 26 February 2018 (Click to enlarge)

Stream Gauge Observations at 1200 UTC on 26 February 2018 (Click to enlarge)

GOES-16 0.86 µm “Veggie” Band Imagery at 1902 UTC on 26 February 2018 (Click to enlarge). Green Arrows highlight the Kankakee River, in flood.


=============== Added, 27 February 2018 ===================
Suomi NPP’s Flood Product, produced via CSPP using data from a Direct Broadcast site (at UW-Madison) is shown below. Flooded regions in the lower Ohio River/Mississippi River Valley and surroundings are indicated by shading in yellow to red.

Suomi NPP Flood Product, 1923 UTC on 26 February 2018 (Click to enlarge)

Some of these areas of river flooding could also be seen in a comparison of Suomi NPP VIIRS True-color and False-color Red-Green-Blue RGB images (below) — the False-color image uses the Near-Infrared 2.2 µm and 0.86 µm bands for the Red and Green contributions, and highlights water as shades of blue.

Suomi NPP VIIRS True-color and False-color images [click to enlarge]

Suomi NPP VIIRS True-color and False-color RGB images [click to enlarge]

Flooding in Southern California

January 9th, 2018 |

1-minute GOES-16 Infrared Window (10.3 µm) images; with hourly reports of surface weather type plotted in yellow [click to play MP4 animation]

1-minute GOES-16 Infrared Window (10.3 µm) images; with hourly reports of surface weather type plotted in red [click to play MP4 animation]

An onshore flow of moisture (MIMIC TPW) in tandem with forcing for ascent with the approach of an upper-level low and a surface cold/occluded front brought heavy rainfall and some higher-elevation snowfall (NWS LOX/SGX | WPC) to much of Southern California on 09 January 2018. To help monitor the event, a GOES-16 (GOES-East) Mesoscale Sector was positioned over the region, providing images at 1-minute intervals. “Clean” Infrared Window (10.3 µm) images (above) showed the colder clouds associated with periods of moderate to heavy rainfall. Some of this precipitation fell over burn scar areas from wildfires that occurred in December 2017 — including the Thomas fire, which was the largest on record for the state of California — resulting in numerous mud/debris slides that caused at least 17 fatalities, destroyed/damaged hundreds of homes, and closed many streets and highways.

GOES-16 “Red” Visible (0.64 µm) images (below) showed some of the features which helped produce heavier rainfall and snowfall during the daylight hours on 09 January.

1-minute GOES-16

1-minute GOES-16 “Red” Visible (0.64 µm) images; with hourly reports of surface weather type plotted in red [click to play MP4 animation]

The circulation of the upper-level low was easily seen on GOES-16 Mid-level Water Vapor (6.9 µm) images (below).

1-minute GOES-16 Water Vapor (6.9 µm) images; with hourly reports of surface weather type plotted in red [click to play MP4 animation]

1-minute GOES-16 Water Vapor (6.9 µm) images; with hourly reports of surface weather type plotted in red [click to play MP4 animation]

===== 10 January Update =====

Suomi NPP VIIRS True-color and False-color RGB images [click to enlarge]

Suomi NPP VIIRS True-color and False-color RGB images [click to enlarge]

On the following day, a toggle between Suomi NPP VIIRS True-color and False-color Red-Green-Blue (RGB) images from RealEarth (above) showed (1) the large burn scar from the Thomas Fire (shades of reddish-brown), and (2) snow cover in the higher terrain (darker shades of cyan) on the False-color image. The True-color image revealed sediment from runoff flowing into the nearshore waters from Santa Barbara to Oxnard (shades of brown to light green).

A closer look at the Thomas Fire burn scar was provided by 30-meter resolution Landsat-8 False-color RGB imagery (below), which showed thin filaments of muddy sediment just offshore, as well as fresh snow cover (shades of cyan) along or immediately adjacent to the northeastern edge of the burn scar (in the Hines Peak area). On 10 January, the fire was listed as 92% contained (100% containment was declared on 12 January).

Landsat-8 False-color RGB image [click to enlarge]

Landsat-8 False-color RGB image [click to enlarge]

===== 11 January Update =====

Suomi NPP VIIRS True-color images on 10 January and 11 January [click to enlarge]

Suomi NPP VIIRS True-color images on 10 January and 11 January [click to enlarge]

A comparison of Suomi NPP VIIRS True-color RGB images on 10 January and 11 January (above) showed that sediment was flowing farther offshore from the Thomas Fire burn scar area.

Farther to the south, offshore sediment transport was also seen in the San Diego area (below).

Suomi NPP VIIRS True-color image on 11 January [click to enlarge]

Suomi NPP VIIRS True-color image on 11 January [click to enlarge]

Heavy rain in Florida

October 26th, 2017 |

Aided in part by precipitation associated with Hurricane Irma, some areas of Florida have received record rainfall during the June-October 2017 period:

* GOES-16 data posted on this page are preliminary, non-operational and are undergoing testing *

GOES-16 Visible (0.64 µm, left), Near-Infrared

GOES-16 Visible (0.64 µm, left), Near-Infrared “Vegetation” (0.86 µm, center) and Near-Infrared “Snow/Ice” (1.61 µm, right) images [click to play animation]

A comparison of GOES-16 “Red” Visible (0.64 µm), Near-Infrared “Vegetation” (0.86 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images (above) showed that water was a strong absorber of radiation at 0.86 µm and 1.61 µm wavelengths — therefore wet ground, rivers, lakes and the oceans appeared dark in those images. This makes those two GOES-16 ABI spectral bands useful for identifying areas of flooding.

Two areas in Florida are noteworthy on the images: the St. Johns River in the northeast part of the state (where Moderate Flooding had been occurring), and parts of South Florida (which had just received an additional 1-5 inches of rain on  the previous day).

A closer look at those 2 areas using Terra MODIS Visible (0.65 µm) and Near-Infrared “:Snow/Ice” (1.61 µm) images are shown below.

Terra MODIS Visible (0.65 µm) and Near-Infrared :Snow/Ice

Terra MODIS Visible (0.65 µm) and Near-Infrared :Snow/Ice” (1.61 µm) images, showing central and northeastern Florida [click to enlarge]

Terra MODIS Visible (0.65 µm) and Near-Infrared :Snow/Ice" (1.61 µm) images, showing southern Florida [click to enlarge]

Terra MODIS Visible (0.65 µm) and Near-Infrared :Snow/Ice” (1.61 µm) images, showing southern Florida [click to enlarge]

In stark contrast to the periods of heavy rain, a strong cold front brought clear skies and very dry air over Florida, as seen in MIMIC Total Precipitble Water product (below).

MIMIC Total Precipitable Water product [click to enlarge]

MIMIC Total Precipitable Water product [click to enlarge]

This dry air evoked enthusiasm in least one South Florida resident: