Severe turbulence over Hawai’i

January 12th, 2018 |

GOES-15 Water Vapor (6.5 µm) images, with hourly pilot reports of turbulence [click to play animation]

GOES-15 Water Vapor (6.5 µm) images, with hourly pilot reports of turbulence [click to play animation]

Numerous pilot reports of moderate to severe turbulence were received over the Hawai’i area on 12 January 2018 — and GOES-15 (GOES-West) Water Vapor (6.5 µm) images (above; also available as an MP4) showed the development of a quasi-stationary gravity wave train over the northwestern portion of the island chain which appeared to be associated with many of these pilot reports.

HNL UA /OV 2115N16010W/TM 2241/FL320/TP B767/TB CONT MOD TURB

HNL UUA /OV 2115N16048W/TM 2255/FL340/TP H/B747/TB MOD-SEV TURB

HNL UUA /OV BOARD/TM 2350/FL370/TP H/B772/TB SEVERE TURB

PHNL UUA /OV 2443N 15516W /TM 2358 /FL370 /TP B737 /TB SEV 370 /RM ZOA CWSU AWC-WEB

In spite of the large satellite viewing angle, these waves were also very evident on Himawari-8 Lower-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images (below; also available as an MP4). The 3 Water Vapor bands on the Himawari AHI are nearly identical to the 3 Water Vapor bands on the GOES-R series ABI.

Himawari-8 Low-level (7.3 µm, left), Mid-level (6.9 µm, center) and 6.2 µm, right) Water Vapor images, with hourly pilot reports of turbulence [click to play animation]

Himawari-8 Low-level (7.3 µm, left), Mid-level (6.9 µm, center) and Upper-level (6.2 µm, right) Water Vapor images, with hourly pilot reports of turbulence [click to play animation]

A toggle between 1-km resolution Terra MODIS Water Vapor (6.7 µm), Infrared Window (11.0 µm) and 250-meter resolution true-color Red-Green-Blue RGB images at 2106 UTC on 12 January (below) showed that no high-altitude clouds were associated with the gravity wave features — thus, these aircraft encounters were examples of Clear Air Turbulence (CAT).

Terra MODIS Water Vapor (6.7 µm) and True-color RGB images [click to enlarge]

Terra MODIS Water Vapor (6.7 µm), Infrared Window (11.0 µm) and true-color RGB images [click to enlarge]

A color-enhanced version of the Aqua MODIS Water Vapor (6.7 µm) image at 0014 UTC on 13 January is shown below (courtesy of Jordan Gerth, CIMSS).

An AWIPS screen capture (below, courtesy of Robert Bohlin, NWS Honolulu and Jordan Gerth, CIMSS) displays a High Pass filter product along with the 3 individual Himawari-8 Water Vapor band images at 0120 UTC on 13 January.

Upper-level Water Vapor (6.2 µm, upper right), Mid-level Water Vapor (6.9 µm, lower left) and Lower-level Water Vapor (7.3 µm, lower right) images [click to enlarge]

Himawari-8 High Pass filter product (6.9 µm, upper left), Upper-level Water Vapor (6.2 µm, upper right), Mid-level Water Vapor (6.9 µm, lower left) and Lower-level Water Vapor (7.3 µm, lower right) images [click to enlarge]

It bears mention that the rawinsonde data from Lihue, Hawai’i at 0000 UTC on 13 January (below) indicated significant wind shear (both speed and directional) within the 200-300 hPa layer (text listing) — the layer in which many of the turbulence reports were found.

Rawinsonde data from Lihue, Hawai'i at 00 UTC on 13 January [click to enlarge]

Rawinsonde data from Lihue, Hawai’i at 00 UTC on 13 January [click to enlarge]

The packet of gravity waves was directly over Lihue (red asterisk) at that time (below).

GOES-15 Water Vapor (6.5 µm) image at 0000 UTC on 13 January, with pilot reports of turbulence plotted. The red asterisk denotes the location of Lihue [click to enlarge]

GOES-15 Water Vapor (6.5 µm) image at 0000 UTC on 13 January, with pilot reports of turbulence plotted. The red asterisk denotes the location of Lihue [click to enlarge]

Blowing snow in North Dakota and Minnesota

January 11th, 2018 |

GOES-16

1-minute GOES-16 “Red” Visible (0.64 µm, left) and Near-Infrared “Snow/Ice” (1.61 µm, right) images, with plots of hourly surface wind barbs in cyan and surface weather type in yellow [click to play MP4 animation]

Several inches of new snow followed by strong northerly winds led to widespread blizzard conditions across the Red River Valley of North Dakota and Minnesota on 11 January 2018 (NWS Grand Forks summary). A GOES-16 (GOES-East) Mesoscale Sector had been positioned over the Upper Midwest to monitor the winter storm, providing images at 1-minute intervals — and a comparison of “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images (above) showed the development of horizontal convective rolls that are a common feature associated with blowing snow.

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]

Final Full Disk images from GOES-13

January 8th, 2018 |

As discussed in this blog post, GOES-13 — launched in May 2006, with a Post Launch Test in December 2006 — served as GOES-East from 2010 to 2017. Image dissemination was terminated on 08 January 2018; the satellite will then begin drifting on 10 January to its storage location at 60º  West longitude. Shown below are the final Full Disk Visible (0.63 µm), Water Vapor (6.5 µm) and Infrared Window (10.7 µm) images broadcast by GOES-13 at 1445 UTC.

GOES-13 Visible (0.63 µm) image [click to enlarge]

GOES-13 Visible (0.63 µm) image [click to enlarge]

GOES-13 Water Vapor (6.5 µm) image [click to enlarge]

GOES-13 Water Vapor (6.5 µm) image [click to enlarge]

GOES-13 Infrared Window (10.7 µm) image [click to enlarge]

GOES-13 Infrared Window (10.7 µm) image [click to enlarge]