Mid-latitude cyclone in the central US

January 22nd, 2018 |

GOES-16 Water Vapor (6.9 µm) images, with hourly precipitation type plotted in yellow [click to play MP4 animation]

5-minute GOES-16 Water Vapor (6.9 µm) images, with hourly precipitation type plotted in yellow [click to play MP4 animation]

A large mid-latitude cyclone intensified over the central US on 22 January 2018, producing a wide variety of weather — in the cold sector, heavy snow and blizzard conditions across the Plains and Upper Midwest (WPC storm summary), and in the warm sector, severe weather (tornadoes, large hail and damaging winds: SPC storm reports) from Mississippi to Illinois, Indiana, and Ohio. GOES-16 (GOES-East) Mid-level Water Vapor (6.9 µm) images (above) showed the large size of the storm circulation, which included a well-defined Warm Conveyor Belt (WCB) and a Trough of Warm Air Aloft (TROWAL) as identified here. More information on conveyor belts and TROWALs is available here.

A GOES-16 Mesoscale Sector provided 1-minute imagery over the Upper Midwest — “Red” Visible (0.64 µm) images (below) revealed some of the convective elements surrounding the surface low as it reached its occluded stage over Iowa. A small cluster of thunderstorms also developed over central Illinois around 19 UTC, producing 1.0-inch diameter hail.

GOES-16 Visible (0.64 µm) images, with hourly precipitation type plotted in yellow [click to play MP4 animation]

1-minute GOES-16 Visible (0.64 µm) images, with hourly precipitation type plotted in yellow [click to play MP4 animation]

Taking a  closer look at the eastern portion of the previous satellite scene, there was an overlap between the M1 and M2 Mesoscale Sectors — this allowed for images at 30-second intervals (below).

30-second GOES-16 Visible (0.64 µm) images, with hourly precipitation type plotted in yellow [click to play MP4 animation]

30-second GOES-16 Visible (0.64 µm) images, with hourly precipitation type plotted in yellow [click to play MP4 animation]

Rope Cloud over the northwest Gulf of Mexico

January 22nd, 2018 |

GOES-16 “Red Visible” 0.64 µm imagery from 1402-2142 UTC on 22 January 2018. (Click to animate)

Visible GOES-16 Satellite Imagery over the northeastern Gulf of Mexico on 22 January 2018 showed the development of a Rope Cloud. Such features have been discussed before on the CIMSS Blog — here, here, here and here! Rope Clouds are handy features in satellite analysis over the ocean because they indicate distinctly where the surface cold front exists. Note that the WPC surface analysis, shown here for 1500 UTC, has the front in the same location as the rope cloud, with convection noted out in advance of the surface cold front. The hourly animation below, showing surface observations and the GOES-16 Red Visible (0.64 µm) Imagery, confirms the windshifts that were observed when the Rope Cloud/Cold Front passed any station.

Hourly Surface Observations and GOES-16 “Red Visible” 0.64 µm imagery from 1400-2200 UTC on 22 January 2018. (Click to enlarge)

Eruption of the Mayon Volcano in the Philippines

January 22nd, 2018 |

Himawari-8 False-color RGB images [click to animate]

Himawari-8 False-color RGB images [click to animate]

The first in a renewed series of eruptions of the Mayon Volcano in the Philippines began around 0450 UTC on 22 January 2018. As seen in Himawari-8 False-color Red-Green-Blue (RGB) images from the NOAA/CIMSS Volcanic Cloud Monitoring site (above), the ash cloud was transported to the northwest.

Multi-spectral retrievals of the Ash Cloud Height (below) indicated that the ash reached altitudes of at least 10 km (dark blue).

Himawari-8 Ash Cloud Height product [click to animate]

Himawari-8 Ash Cloud Height product [click to animate]

A plot of rawinsonde data from nearby Legaspi at 00 UTC on 22 January (below) indicated that the 10 km altitude corresponded to a pressure of 285 hPa.

Plot of rawinsonde data from Legaspi, Philippines [click to enlarge]

Plot of rawinsonde data from Legaspi, Philippines [click to enlarge]

A Suomi NPP VIIRS True-color RGB image from RealEarth (below) revealed some of the lower-altitude ash (shades of tan to brown) drifting toward the west at the satellite overpass time of 0507 UTC. Thermal anomalies — signatures of hot lava flows — are indicated by red dots.

Suomi NPP VIIRS True-color RGB image [click to enlarge]

Suomi NPP VIIRS True-color RGB image [click to enlarge]