Tropical Storm Matthew in the Windward Islands

September 28th, 2016

Note: Matthew was upgraded to a Hurricane at 1800 UTC on 29 September. See the National Hurricane Center Website for the latest information.

GOES-13 Visible (0.63 µm) and shortwave Infrared (3.9 µm) at 6-hour intervals, 23-28 September 2016 [Click to animate]

GOES-13 Visible (0.63 µm) and shortwave Infrared (3.9 µm) at 6-hour intervals, 23-28 September 2016 [Click to animate]

The area of disturbed weather that has been moving across the tropical Atlantic for the past week, shown above in six-hour steps using visible (0.63 µm) imagery during the day and shortwave infrared (3.9 µm) imagery at night, has developed into a strong tropical storm, named Matthew, as it moves through the Windward Islands. Matthew is embedded with the rich moisture source of the Intertropical Convergence Zone, as shown in the animation below of MIRS Total Precipitable Water, taken from this source. Matthew is also heading towards a region rich in moisture — it appears that dry air should not influence Matthew’s evolution in the near term.

Morphed MIRS Total Precipitable Water, 25-28 September 2016 [Click to animate]

Morphed MIRS Total Precipitable Water, 25-28 September 2016 [Click to animate]

Matthew’s predicted course into the Caribbean is over very warm water with high heat content (below, imagery from the CIMSS Tropical Weather site). Wind shear over the storm is low, with larger values to the west; the region of high shear in advance of Matthew has been preceding the storm for the past 72 hours and it is forecast to continue its retreat from Matthew. The forecast from the National Hurricane Center is for slow strengthening.

Observed Sea Surface Temperatures and Oceanic Heat Content [Click to enlarge]

Observed Sea Surface Temperatures and Oceanic Heat Content [Click to enlarge]

Wind Shear, 1500 UTC on 28 September [Click to enlarge]

Wind Shear, 1500 UTC on 28 September [Click to enlarge]

Late in the afternoon on the 28th, GOES-13 detected cloud tops cooler than -80º C associated with some of the overshooting tops (the purple enhancement). Overshooting tops can be detected automatically and shown at this website.

GOES-13 Infrared (10.7 µm) imagery, 1445-2045 UTC on 28 September 2016 [Click to animate]

GOES-13 Infrared (10.7 µm) imagery, 1445-2045 UTC on 28 September 2016 [Click to animate]


============== Added, 29 September 2016 =================

Suomi NPP overflew the eastern Caribbean early on 29 September, and the Day Night Band imagery, below, (from RealEarth) shows Matthew west of the Windward Islands. A lone lightning strike is visible in the convective clouds. There appears in this very low light image to be a low-level circulation exposed to the west of the deep clouds, suggesting a sheared storm.

Suomi NPP Day Night Band Visible (0.70 µm) imagery, ~0540 UTC on 29 September 2016 [Click to enlarge]

Suomi NPP Day Night Band Visible (0.70 µm) imagery, ~0540 UTC on 29 September 2016 [Click to enlarge]

A GOES-13 Visible Image animation from just after sunrise shows a the circulation center exposed to the west of the deep convection.

GOES-13 Visible (0.63 µm) imagery, 1045-1245 UTC on 29 September 2016 [Click to enlarge]

GOES-13 Visible (0.63 µm) imagery, 1045-1245 UTC on 29 September 2016 [Click to enlarge]

NOAA-19 overflew Matthew at about 1900 UTC on 29 September 2016, shortly after the storm was upgraded to a Hurricane, and visible imagery from that pass (data courtesy of the AOML Direct Broadcast antenna) shows far less evidence of a sheared storm. The Central Dense Overcast is above the surface circulation.

NOAA-19 Visible (0.63 µm) imagery, 1931 UTC on 29 September 2016 [Click to enlarge]

NOAA-19 Visible (0.63 µm) imagery, 1931 UTC on 29 September 2016 [Click to enlarge]

The Loma fire in California

September 27th, 2016

Suomi NPP VIIRS imagery from the Day/Night Band visible (0.70 µm) and Infrared (3.74 µm) at 0936 UTC on 27 September, and terrain [Click to enlarge]

Suomi NPP VIIRS imagery from the Day/Night Band visible (0.70 µm) and Infrared (3.74 µm) at 0936 UTC on 27 September, and terrain [Click to enlarge]

Between 0900 and 1000 UTC on 27 September (2 AM and 3 AM PDT) Suomi NPP overflew the Loma fire that is burning in the high terrain between Santa Clara and Santa Cruz counties in northern California. (News Article 1; News Article 2) The toggle above shows the glow of the fire in the nighttime visible imagery from the Day/Night Band on the VIIRS instrument. This glow is along the border of the two counties, well removed from the glow of nearby cities. The fire hot spot as detected by the 3.7 micron channel is apparent as well. Smoke from the fire is difficult to detect in this low-light scene (the waxing quarter moon was below the horizon at the time of the image, shedding no light on the scene).

GOES-15 can provide 3.9 µm imagery roughly 4 times per hour (when GOES-R is launched, shortwave infrared imagery will be produced every 5 minutes over the continental United States) allowing a better indication of how the fire is evolving with time. The animation below, from 0500 through 1530 UTC, shows a cooling trend in the warmest pixels (hottest pixels are colored red in the animation, then yellow, then black), which is expected as winds that drive the fire relax at night. There is notable motion in the navigation of this image. GOES-15 is operating with only 1 Star Tracker (vs. the usual 3), resulting in less-precise image navigation.

GOES-15 shortwave infrared (3.9 µm) imagery from 0500 UTC through 1500 UTC on 27 September [Click to animate]

GOES-15 shortwave infrared (3.9 µm) imagery from 0500 UTC through 1500 UTC on 27 September [Click to animate]

Visible Imagery from GOES-15 after sunrise on 27 September shows a long smoke plume moving southeastward from the fire source.

GOES-15 visible (0.62 µm) imagery from 1430 to 1530 UTC on 27 September [Click to enlarge]

GOES-15 visible (0.62 µm) imagery from 1430 to 1530 UTC on 27 September [Click to enlarge]

Widespread power outage in Puerto Rico

September 23rd, 2016

Suomi NPP VIIRS Day/Night Band (0.7 um) images: cloud-free "clear view" (31 Dec 2015) vs 22 September and 23 September 2016 [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 um) images: cloud-free “clear view” (31 Dec 2015) vs 22 September and 23 September 2016 [click to enlarge]

A fire at the Aguirre power plant in Salinas (located along the southern coast of Puerto Rico) on 21 September 2016 triggered a widespread power outage across the island. A comparison of Suomi NPP VIIRS Day/Night Band (0.7 um) images of Puerto Rico on a cloud-free “clear view” night (31 December 2015) and the 2 nights following the power outage (22 and 23 September) is shown above (visualized using RealEarth); the nighttime glow of city lights is dramatically reduced on the 22 September image, while some restoration of power to much of the island — reportedly 75% — is apparent on the 23 September image.  Additional details and images can be found on the NASA Earth Observatory site.

Tropical Storm Karl

September 19th, 2016
Suomi NPP VIIRS imagery from the Day/Night Band visible (0.70 µm) and Infrared (11.45 µm) at 0351 UTC on 19 September [Click to enlarge]

Suomi NPP VIIRS imagery from the Day/Night Band visible (0.70 µm) and Infrared (11.45 µm) at 0351 UTC on 19 September [Click to enlarge]

Tropical Storm Karl in the middle of the Atlantic Ocean was a disorganized storm early on 19 September (as noted in these two discussions from the National Hurricane Center at 0300 and 0900 UTC): the surface circulation was displaced to the south and west of the deep convection. Night-time determination of the center location from infrared imagery for such storms is difficult. However, the Day/Night Band on the VIIRS instrument on board Suomi NPP can provide visible imagery at night and such visible imagery can aid in surface feature detection. The toggle above shows the 11.45 µm Infrared image from Suomi NPP just before 0400 UTC and the 0.70 µm Day/Night Band visible image from the same time. With the aid of ample illumination from the Moon (that was in the Waning Gibbous phase, at 85% of Full) the low-level swirl of clouds was apparent near the storm center at 18.2 N, 46.7 W (a bit south and west of the center as noted by the National Hurricane Center at 0300 UTC).

A zoomed-in image toggle centered on the low-level circulation is below.

(Imagery courtesy of William Straka, SSEC)

Suomi NPP VIIRS imagery from the Day/Night Band visible (0.70 µm) and Infrared (11.45 µm) at 0351 UTC on 19 September over the center of Karl [Click to enlarge]

Suomi NPP VIIRS imagery from the Day/Night Band visible (0.70 µm) and Infrared (11.45 µm) at 0351 UTC on 19 September over the center of Karl [Click to enlarge]