Ex-hurricane Ophelia over Ireland and the United Kingdom

October 16th, 2017 |

Meteosat-10 Water Vapor (6.25 µm) images, with hourly surface wind gusts (knots) plotted in red [click to play MP4 animation]

Meteosat-10 Water Vapor (6.25 µm) images, with hourly surface wind gusts (knots) plotted in red [click to play MP4 animation]

After reaching Category 3 intensity over the eastern Atlantic Ocean on 14 October, Hurricane Ophelia rapidly underwent transition to an extratropical storm which spread high winds across much of Ireland and the United Kingdom on 16 October 2017. EUMETSAT Meteosat-10 upper-level Water Vapor (6.25 µm) images (above) revealed the familiar “scorpion tail” signature of a sting jet (reference). Hourly wind gusts (in knots) from primary reporting stations are plotted in red.

The sting jet signature was also seen on Meteosat-10 lower-level Water Vapor (7.35 µm) images (below).

Meteosat-10 Water Vapor (7.35 µm) images, with hourly surface wind gusts (knots) plotted in red [click to play MP4 animation]

Meteosat-10 Water Vapor (7.35 µm) images, with hourly surface wind gusts (knots) plotted in red [click to play MP4 animation]

Two sites with notable wind gusts were Cork, Ireland (67 knots at 0930 UTC) and Valley, UK (70 knots at 1500 UT), shown below. In fact, a wind gust of 103 knots (119 mph or 191 km/hour) was reported at the Fastnet Rock Lighthouse off the southwest coast of Ireland.

Time series plot of surface data from Cork, Ireland [click to enlarge]

Time series plot of surface data from Cork, Ireland [click to enlarge]

Time series plot of surface data from Valley, United Kingdom [click to enlarge]

Time series plot of surface data from Valley, United Kingdom [click to enlarge]

Terra and Aqua MODIS true-color images [click to enlarge]

Terra and Aqua MODIS true-color images [click to enlarge]

In a toggle between Terra MODIS (overpass time around 1159 UTC) and Aqua MODIS (overpass time around 1345 UTC) true-color Red/Green/Blue (RGB) imagery (above), a somewhat hazy appearance was seen over the Irish Sea on the Terra MODIS image.

Of particular interest was the observation of blowing sand about 3 hours later at Isle of Man, from 1520-1620 UTC — during that time period their surface winds gusted to 68 knots (78 mph), and surface visibility was reduced to 2.2 miles (below).

Time series plot of surface data from Isle of Man [click to enlarge]

Time series plot of surface data from Isle of Man [click to enlarge]

Wildfires in Northern California

October 9th, 2017 |

GOES-16 Shortwave Infrared (3.9 µm) images, with county outlines plotted in gray (dashed) and surface station identifiers plotted in white [click to play MP4 animation]

GOES-16 Shortwave Infrared (3.9 µm) images, with county outlines plotted in gray (dashed) and surface station identifiers plotted in white [click to play MP4 animation]

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

GOES-16 Shortwave Infrared (3.9 µm) images (above) showed the “hot spot” signatures (black to yellow to red pixels) associated with numerous wildfires that began to burn in Northern California’s Napa County around 0442 UTC on 09 October 2017 (9:42 PM local time on 08 October). A strong easterly to northeasterly Diablo wind (gusts) along with dry fuels led to extreme fire behavior, with many of the fires quickly exhibiting very hot infrared brightness temperature values and growing in size at an explosive rate (reportedly burning 80,000 acres in 18 hours).

A comparison of nighttime GOES-16 Shortwave Infrared (3.9 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images (below) offered another example of nocturnal fire signature identification — the bright glow of the fires showed up well on the 1-km resolution 1.61 µm imagery. Especially noteworthy was the very rapid southwestward run of the Tubbs Fire, which eventually moved just south of station identifier KSTS (Santa Rosa Sonoma County Airport; the city of Santa Rosa is located about 5 miles southeast of the airport. These Northern California fires have resulted in numerous fatalities, destroyed at least 3500 homes and businesses, and forced large-scale evacuations (media story).

GOES-16 Shortwave Infrared (3.9 µm, left) and Near-Infrared

GOES-16 Shortwave Infrared (3.9 µm, left) and Near-Infrared “Snow/Ice” (1.61 µm, right) images [click to play MP4 animation]

A toggle between 1007 UTC (3:07 AM local time) Suomi NPP VIIRS Shortwave Infrared (3.74 µm) and Day/Night Band (0.7 µm) images (below) provided a view of the fires at an even higher spatial resolution. Since the Moon was in the Waning Gibbous phase (at 82% of Full), it provided ample illumination to highlight the dense smoke plumes drifting west-southwestward over the adjacent offshore waters of the Pacific Ocean.

Suomi NPP VIIRS Shortwave Infrared (3.74 µm) and Day/Night Band (0.7 µm) images [click to enlarge]

Suomi NPP VIIRS Shortwave Infrared (3.74 µm) and Day/Night Band (0.7 µm) images [click to enlarge]

A closer VIIRS image comparison (with county outlines) is shown below.

Suomi NPP VIIRS Shortwave Infrared (3.74 µm) and Day/Night Band (0.7 µm) images [click to enlarge]

Suomi NPP VIIRS Shortwave Infrared (3.74 µm) and Day/Night Band (0.7 µm) images [click to enlarge]

A comparison of Suomi NPP VIIRS true-color and false-color Red/Green/Blue (RGB) images from RealEarth (below) helped to discriminate between smoke and cloud features offshore over the Pacific Ocean.

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]

===== 10 October Update =====

Suomi NPP VIIRS true-color and false-color images [click to enlarge]

Suomi NPP VIIRS true-color and false-color images [click to enlarge]

With the switch to southwesterly surface winds on 10 October, smoke plumes could be seen moving northeastward on RealEarth VIIRS true-color imagery, while the burn scars of a number of the larger fires became apparent on VIIRS false-color RGB imagery (above).

===== 12 October Update =====

Suomi NPP VIIRS true-color RGB images, with VIIRS-detected fire locations [click to enlarge]

Suomi NPP VIIRS true-color RGB images, with VIIRS-detected fire locations [click to enlarge]

A transition back to northerly winds on 12 October helped to transport the wildfire smoke far southward over the Pacific Ocean (above). Smoke was reducing surface visibility and adversely affecting air quality at locations such as San Francisco (below).

Time series plot of surface observations at San Francisco International Airport [click to enlarge]

Time series plot of surface observations at San Francisco International Airport [click to enlarge]

Suomi NPP VIIRS Aerosol Optical Depth values were very high — at or near 1.0 — within portions of the dense smoke plume (below).

Suomi NPP VIIRS true-color RGB image and Aerosol Optical Depth product [click to enlarge]

Suomi NPP VIIRS true-color RGB image and Aerosol Optical Depth product [click to enlarge]

Increase in Gulf of Mexico water turbidity in the wake of Hurricane Irma

September 11th, 2017 |

Suomi NPP VIIRS true-color RGB images on 07 September and 11 September [click to enlarge]ep

A comparison of Suomi NPP VIIRS true-color Red/Green/Blue (RGB) images on 07 September (before Irma) and 11 September (after Irma) revealed a marked increase in turbidity of the shallow Continental Shelf waters off the coast of southern/southwestern Florida and the Florida Keys. Irma moved through that region on 10 September as a Category 3 hurricane — and even though the center of Irma moved northward off/along the west coast of Florida (with a wind gust to 75 mph at Key West) , the strongest winds were recorded along/near the east coast of Florida: wind gusts to 92 mph and 109 mph and 142 mph — stirring up particulates within the shallow Continental Shelf waters.

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

Large-scale (CONUS) VIIRS true-color before-Irma and after-Irma images are available here and here. Note that the cloud shield of Irma had expanded as far westward as Kansas, Texas and Oklahoma on 12 September ( GOES-16 true-color images) — in addition to large areas of dense smoke from wildfires in the Pacific Northwest (blog post) which was drifting eastward across the northern US.

Widespread Smoke in the Pacific Northwest

September 6th, 2017 |

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

Dry weather over the Pacific Northwest (and over Idaho and Montana) has created an ideal environment lately for wildfires, and much of the region is shrouded in smoke from those fires as shown in the Suomi NPP True Color Imagery, above, from this site.  Note the red points that are Suomi-NPP-detected fires; they persist from day to day, and some grow in size during the course of the animation. GOES-16 Animations of True Color (in this case, the CIMSS Natural True Color product that is created using Bands 1, 2 and 3 (0.47 µm, 0.64 µm and 0.86 µm, respectively)), below, (also available here; a similar product from CIRA is available here), show the pall of smoke as well. Air Quality Alerts from the National Weather Service were widespread on 6 September.

CIMSS Natural True Color, every 15 minutes, from 1400-2130 UTC on 6 September 2017 (Click to animate)

GOES-16 has multiple channels and products that can view both the Smoke and the Fires that produce the smoke. In addition to the visible imagery, Fire Products, below, can characterize the Temperature, Power (in megawatts) and area (in square meters) of the fire detected by GOES-16.  On this day, clouds over the fires in Oregon mean that satellite detection is challenged, even though the by-product, smoke, is apparent.  Fires over Idaho are readily apparent however.  These fires were also detected by the 3.9 µm Shortwave Infrared channel on GOES-16, the traditional fire-detection channel (used in concert with 10.3 µm, the clean window channel).  Imagery at 1.6 µm and 2.2 µm imagery can also be used to highlight hot fires;  that will be the subject of a future blog post.

GOES-16 Fire Products: Fire Temperature, Fire Power and Fire Area, 2037 UTC on 6 September 2017 (Click to enlarge)

 

The mp4 animation, below, shows CIMSS Natural True Color over the Full Disk on 5 September 2017.  The Full Disk View allows a better visualization of how the smoke is moving (and underscores how widespread it is) — and it shows Hurricane Irma as well.

CIMSS Natural True Color, every 15 minutes, on 5 September 2017 (Click to animate)

 

NOAA creates many Smoke-related products, some of which are easily accessible at this link.