Mesoscale Convective Vortex generated by monsoon thunderstorms in Arizona

July 9th, 2018 |

As mentioned by NWS San Diego, monsoon thunderstorms that developed over Arizona spawned a small Mesoscale Convective Vortex (MCV). The animation below shows nighttime GOES-16 (GOES-East) “Clean” Infrared Window (10.3 µm) images, followed by daytime GOES-16 “Red” Visible (0.64 µm) images — the center of the MCV circulation briefly exhibited an “eye-like” appearance just after 16 UTC (south of the California/Mexico border).

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) and “Red” Visible (0.64 µm) images, with hourly plots of surface reports [click to play MP4 animation]

A 1-km resolution NOAA-19 Infrared Window (10.8 µm) image at 1132 UTC (below) showed a more detailed view of the small cluster of thunderstorms responsible for the MCV — the convection produced 0.68″ of rainfall near Yuma KNYZ in far southwestern Arizona, and generated an outflow boundary which produced wind gusts to 46 mph at Thermal, California KTRM (NWS statements).

NOAA-19 AVHRR Infrared Window (10.8 µm) image [click to enlarge]

NOAA-19 AVHRR Infrared Window (10.8 µm) image [click to enlarge]

A toggle between 1-km resolution NOAA-15 and NOAA-18 Visible (0.63 µm) images (below) revealed the emergence of the eye-like MCV center in far northern Baja California (just southeast of Campo, California KCZZ) at 1547 UTC.

NOAA-15 and NOAA-18 Visible (0.63 µm) images [click to enlarge]

NOAA-15 and NOAA-18 Visible (0.63 µm) images [click to enlarge]

Blooming canola fields in North Dakota and Manitoba

July 9th, 2018 |

Terra MODIS True Color RGB images on 06 June, 05 July and 09 July 2018 [click to enlarge]

Terra MODIS True Color RGB images on 06 June, 05 July and 09 July 2018 [click to enlarge]

A toggle between Terra MODIS True Color Red-Green-Blue (RGB) images (from the MODIS Today site) on 06 June, 05 July and 09 July 2018 (above) revealed the brightening yellow-green hues of blooming canola fields across parts of northeastern North Dakota and southern Manitoba. Note that changes can even be seen between the 2 days in early July!

Credit to NWS Grand Forks for alerting us to this interesting phenomenon.


Super Typhoon Maria

July 5th, 2018 |

Himawari-8 Visible (0.64 µm, left) and Infrared Window (10.4 µm, right) images [click to play MP4 animation]

Himawari-8 “Red” Visible (0.64 µm, left) and “Clean” Infrared Window (10.4 µm, right) images [click to play MP4 animation]

Typhoon Maria underwent a period of rapid intensification (ADT | SATCON) while it was just northwest of Guam late in the day on 05 July 2018, becoming the first Category 5 Super Typhoon of the 2018 West Pacific season. Rapid-scan Himawari-8 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.4 µm) images (above) showed Maria during this period of rapid intensification. Cloud-top infrared brightness temperatures reached -80ºC (violet enhancement) at times in the eyewall of the storm.

A GPM GMI Microwave (85 GHz) image from the CIMSS Tropical Cyclones site (below) showed the pinhole eye of Maria around the time it reached Category 5 intensity. The tropical cyclone was moving over water with high values of Ocean Heat Content — and was in an environment characterized by low values of Deep-layer Wind Shear.

GPM GMI Microwave (85 GHz) image [click to enlarge]

GPM GMI Microwave (85 GHz) image [click to enlarge]

Mesovortices could be seen within the eye on Himawari-8 Visible imagery (below). However, note how the eye became less distinct and increased in diameter toward the end of the animation.

Himawari-8

Himawari-8 “Red” Visible (0.64 µm) images [click to play MP4 animation]

Shortly after 00 UTC on 06 July, Maria began the process of an eyewall replacement cycle as shown in MIMIC TC morphed microwave imagery (below) — and during the following 6-12 hours a decreasing trend in storm intensity was seen (ADT | SATCON).

MIMIC TC morphed microwave image product [click to play animation]

MIMIC TC morphed microwave image product [click to play animation]

A toggle between Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1603 UTC on 06 July (below; courtesy of William Straka, CIMSS) showed Category 4 Typhoon Maria after the eye had filled following the eyewall replacement cycle.

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

===== 08 July Update =====

Himawari-8

Himawari-8 “Clean” Infrared Window (10.4 µm) images [click to play MP4 animation]

Super Typhoon Maria re-intensified to Category 5 intensity at 12 UTC on 08 July (SATCON) — Himawari-8 “Clean” Infrared Window (10.4 µm) images (above) displayed a large (30 nautical mile wide) eye. The subtle signature of mesovortices could be seen rotating within the eye.

During the preceding daylight hours, Himawari-8 “Red” Visible (0.64 µm) images (below) showed the eye mesovortices in better detail.

Himawari-8

Himawari-8 “Red” Visible (0.64 µm) images [click to play MP4 animation]

However, Maria was again downgraded to a Category 4 storm at 00 UTC on 09 July, as another eyewall replacement cycle took place (DMSP-17 microwave image) and the storm began to move over water having slightly cooler Sea Surface Temperature and Ocean Heat Content. The eye and its mesovortices continued to be prominent in Himawari-8 Visible and Infrared imagery (below).

Himawari-8

Himawari-8 “Red” Visible (0.64 µm, left) and “Clean” Infrared Window (10.4 µm, right) images [click to play MP4 animation]

Severe thunderstorms in North Dakota and South Dakota

July 4th, 2018 |

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images, with SPC storm reports plotted in blue [click to play MP4 animation]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Clean” Infrared Window (10.3 µm) images (above) showed the merger of two Mesoscale Convective Systems over North Dakota and South Dakota during the nighttime (pre-sunrise) hours on 04 July 2018. In addition to hail of 1.00-2.00 inches in diameter, these thunderstorms produced widespread damaging winds up to 95 mph in north-central South Dakota (SPC storm reports).

Nighttime comparisons of VIIRS instrument Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) imagery from the Suomi NPP and NOAA-20 satellites are shown below (courtesy of William Straka, CIMSS). With illumination from the Moon (which was in the Waning Gibbous phase, at 68% of Full), the “visible image at night” capability of the Day/Night Band was demonstrated; numerous bright lighting streaks could also be seen, with many in the vicinity of the cold overshooting tops that were evident on Infrared imagery. The Infrared images also revealed cloud-top gravity waves which were propagating radially outward away from the primary clusters of cold overshooting tops.

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]