Suomi NPP VIIRS 0.7 µm Day/Night Band + 11.45 µm IR + "Fog/stratus product" images

An AWIPS comparison of Suomi NPP VIIRS 0.7 µm Day/Night Band (DNB), 11.45 µm IR, and IR brightness temperature difference “Fog/stratus product” images at 06:51 UTC on 09 May 2012 (above) revealed several ribbons of the aurora borealis (which showed up as bright west-to-east oriented features on the DNB image over Ontario and Quebec, Canada). Note that there was no correlation between these bright DNB aurora features and any high cloud features on the 11.45 µm IR image, or  any low cloud or fog features on the legacy “fog/stratus product” image.

These aurora features would have been along the southern periphery of the auroral oval, which was expanding southward at that time  according to images from the Space Weather Prediction Center (below).

Space Weather Prediction Center auroral oval product images

Photos of the aurora borealis were taken from Upsala, Ontario — located approximately halfway between Thunder Bay (station identifier CYQT) and Dryden (station identifier CYHD) — and posted on Spaceweather.com. These photos were taken about an hour prior to the VIIRS images shown above.

View only this post Read Less

Suomi NPP VIIRS 0.7 µm Day/Night Band image + 11.45 µm IR image

A surface outflow boundary (resulting from a dissipating mesoscale convective system over southern Texas) created an undular bore that propagated southward and southwestward during the night-time hours on 07 May 2012. AWIPS comparisons of 1-km resolution Suomi NPP VIIRS 0.7 µm “Day/Night Band” images with the corresponding VIIRS 11.45 µm IR images at 07:27 UTC or 2:27 am local time (above) and also at 09:08 UTC or 4:08 am local time (below) demonstrated how the Day/Night Band imagery could be used to better visualize the individual cloud band structures of the bore. On the Day/Night Band images, cloud features could be seen due to moonlight illumination, and bright areas of city lights were also very prominent.

Suomi NPP VIIRS 0.7 µm Day/Night Band image + 11.45 µm IR image

This undular bore could also be seen on 4-km resolution GOES-13 10.7 µm IR images (below), although the individual cloud band features were not as well-defined due to the coarser spatial resolution. At Junction, Texas (station identifier KJCT), east-northeasterly winds gusted to 25 knots (29 mph) at 3:43 am local time as the bore passed.

GOES-13 10.7 µm IR images

View only this post Read Less

MTSAT-2 6.7 µm water vapor channel images (click image to play animation)

Tornadoes are relatively rare in Japan, and the majority of them occur in association with tropical cyclones — but a tornado struck the city of Tsukuba, Japan on 06 May 2012, and was responsible for one fatality, over 40 injuries, and damage (rated F2 to F3) to nearly 500 homes and buildings. MTSAT-2 6.7 µm water vapor channel images (above; click image to play animation) showed that strong convection developed over Japan along the eastern periphery of a large upper-level low. The location of Tokyo Narita International Airport (station identifier RJAA) is overlaid on the images — Tsukuba is about 30 miles northwest of RJAA.

Also important to note on the water vapor imagery (prior to 05 UTC) was the appearance of a small area of lee waves immediately downwind of the Mt. Fuji area (just to the west of RJAA), suggesting the presence of a strong jet streak moving northeastward over the Japanese island of Honshu. A longer animation showed the development of a number of distinct cyclonic vortices, many marked by a pronounced warm/dry signature on the water vapor imagery. These vortices corresponded to individual Potential Vorticity (PV) anomalies; one of the stronger PV anomalies moved just south of RJAA and helped to initiate a new cluster of convection offshore toward the end of the long animation.

A closer view using MTSAT-2 10.8 µm IR channel images (below; click image to play animation) showed that cloud top IR brightness temperatures associated with the tornadic supercell quickly cooled to the -55 to -60º C range (darker red color enhancement), and exhibited subtle cold/warm thermal couplets and brief enhanced-V signature at 04:01 UTC.

MTSAT-2 10.8 µm IR channel images (click image to play animation)

MTSAT-2 0.7 µm visible channel images (below; click image to play animation) revealed subtle indications of overshooting tops, as well as a brief anvil plume (at 06:32 UTC). The hazy signature of a blowing dust plume was also evident just to the south and east of Japan.

MTSAT-2 0.7 µm visible channel images (click image to play animation)

The tornado was reported to have occurred at Tsukuba around 1 pm local time (05:00 UTC), with hail at Mito around 1:20 pm local time (05:20 UTC). The location of the tornado (T) and hail (H) are overlayed on a close-up view of the 05:01 UTC MTSAT-2 0.7 µm visible channel image (below), which showed a well-defined flanking line boundary of convection feeding northwestward into the parent thunderstorm.

MTSAT-2 0.7 µm visible image + Surface reports + Tornado and Hail report locations

View only this post Read Less

GOES-13 10.7 µm IR channel images (click image to play animation)

AWIPS images of 4-km resolution GOES-13 10.7 µm IR channel data (above; click image to play animation) showed the development of large thunderstorms over the far eastern Gulf of Mexico during the pre-dawn hours on 03 May 2012.

Better detail of the cold convective cloud tops could be seen in a series of 1-km resolution POES AVHRR 10.8 µm IR and MODIS 11.0 µm IR channel images (below).

POES AVHRR 10.8 µm IR and MODIS 11.0 µm IR images

McIDAS images of 1-km resolution GOES-13 0.63 µm visible channel data (below; click image to play animation) revealed the formation of a mesoscale convective vortex (MCV) after the night-time convection dissipated.

GOES-13 0.63 µm visible channel images (click image to play animation)

A GOES-13 10.7 µm IR image at 16:10 UTC with an overlay of ASCAT scatterometer surface winds at 16:05 UTC (below) suggested that the MCV was causing a perturbation in the general southeasterly flow as it was beginning to organize.

GOES-13 10.7 µm IR image + ASCAT scatterometer surface winds

View only this post Read Less