Super Typhoon Jelawat

March 30th, 2018 |

Himawari-8 “Red” Visible (0.64 µm) Imagery, hourly from 2200 UTC 29 March through 0800 UTC 30 March (Click to animate)

Super Typhoon Jelawat has developed in the central Pacific Ocean, to the west of Guam and the Marianas Islands. The hourly imagery, above, from Himawari-8, from 2200 UTC on 29 March through 0800 UTC on 30 March show a rapid eye development. Satellite presentation seems best at around 0500 UTC, with a well-defined eye. Subsequently, high clouds covered the eye as it became less symmetric.

Himarwari-8 AHI Band 13 (“Clean Window”, 10.41 µm) Infrared Imagery, 2300 UTC on 29 March 2018 through 0140 UTC on 30 March 2018 (Click to enlarge)

Infrared Imagery (10.41 µm) imagery, above, shows a well-defined eye shortly after 0000 UTC. Following a data outage, imagery from 1400 UTC to 1600 UTC, below, shows a central region of cold convective clouds, but no obvious eye.

Himarwari-8 AHI Band 13 (“Clean Window”, 10.41 µm) Infrared Imagery, 1420 UTC on 30 March 2018 through 1600 UTC on 30 March 2018 (Click to enlarge)

Water Vapor Infrared Imagery from Himawari, below, shows that outflow from Jelawat is well-established to the north; outflow appears to be entrained into the mid-latitude westerlies. MIMIC Total Precipitable Water for the 24 hours ending 1600 UTC on 30 March (shown underneath the water vapor infrared imagery below) also shows the entrainment of tropical moisture around Jelawat into mid-latitudes.  The Total Precipitable Water shows a band of rich moisture extending to the east-southeast of Jelawat, portending a wet period for the Marianas Islands.

Himawari-8 AHI Water Vapor Imagery, Bands 8 (6.24 µm) and 10 (7.35 µm) at 1600 UTC on 30 March 2018 (Click to enlarge)

Morphed Microwave Observations of Total Precipitable Water, 1700 UTC on 29 March 2018 to 1600 UTC on 30 March 2018 (Click to enlarge)

Morphed Storm-centered Microwave Imagery for the 24 hours ending at 0900 UTC on 30 March, 2018 (from this site), show the rapid intensification after 0000 UTC on 30 March.  (Update:  a similar animation that ends at 1900 UTC on 30 March 2018 demonstrates a rapid collapse of the eyewall convection!)

Morphed Microwave Imagery for the 24 hours ending at ~0900 UTC on 30 March 2018 (Click to enlarge)

Full-resolution Visible Imagery from AHI (Band 3, 0.64) is shown below. (Faster and slower animations are available). A rapid organization and clearing of the eye is apparent around 0400 UTC with an equally-rapid apparent subsequent obscuration.

Full-Resolution Himawari-8 “Red” Visible (0.64 µm) Imagery, hourly from 0000 UTC 30 March through 0850 UTC 30 March (Click to animate)

GCOM overflew the storm at around 1610 UTC on 30 March, and the toggle below shows the 36.5 and 89.0 Ghz imagery over the storm (the same enhancement is used in each image).  The 36.5 Ghz imagery suggests a very asymmetric storm.  Eyewall convection in the 89 Ghz imagery is not robust. (These data were downloaded at the Direct Broadcast antenna on Guam and are courtesy Kathy Strabala, SSEC/CIMSS)

GCOM AMSR-2 36.5 and 89.0 GHz imagery over Jelawat, 1604 UTC on 30 March 2018 (Click to enlarge)

NOAA-20 and Suomi NPP also both overflew Jelawat around 1600 UTC on 30 March. The toggles below show NOAA-20 and then Suomi NPP Day Night Band visible imagery. and Infrared 11.45 Imagery, at 1549 and 1639 UTC. (Imagery courtesy William Straka, SSEC/CIMSS)  In contrast to the Visible and Infrared imagery from Himawari earlier in the day (at top), an eye is not present.  (Note that NOAA-20 data are provisional, non-operational, and undergoing testing still.)

VIIRS Infrared Imagery (11.45 µm) from NOAA-20 (1549 UTC) and Suomi NPP (1639 UTC) on 30 March 2018 (Click to enlarge)

VIIRS Day Night Band Visible Imagery (0.70 µm) from NOAA-20 (1549 UTC) and Suomi NPP (1639 UTC) on 30 March 2018 (Click to enlarge)

Suomi NPP also overflew the storm on 29 March 2018, at 0421 UTC. This was before Jelawat’s rapid intensification. The toggle below again uses data from the Direct Broadcast antenna on Guam and shows VIIRS visible (0.64 µm) and infrared (11.45 µm) imagery, MIRS products (Total Precipitable Water and Rain Rate) derived from data from the ATMS microwave sounder on Suomi NPP, and individual microwave channels from ATMS: 31, 88, 165 and 183 Ghz.

Suomi NPP VIIRS Visible (0.64 µm) and Infrared (11.45 µm) Imagery, MIRS Total Precipitable Water and Rain Rate, and individual Suomi NPP ATMS Channels: 31, 88, 165 and 183 GHz, all at 0421 UTC on 29 March 2018 (Click to enlarge)

Interests in the Marianas Islands should closely monitor the progress and evolution of this storm. This site and this site both have information on the system.

The March of Cyclones in a ‘Foureaster’ Animation

March 27th, 2018 |

GOES-16 ABI Imagery from 28 February through 24 March 2018 at 15-minute time steps. CIMSS Natural Color imagery is shown during the day, a blend of GOES-16 ABI Shortwave (3.9 µm) and Longwave (10.3 µm) Infrared imagery is shown at night. (Click to open YouTube animation)

Four weeks of GOES-16 Full-Disk imagery, spanning 28 February to 24 March at a 15-minute interval, showing four Nor’easters, are available via the image above at YouTube.  The imagery shows CIMSS Natural Color during the day and a blend of GOES-16 ABI Shortwave (3.9 µm) and Longwave (10.3 µm) Infrared imagery at night.

The original mp4 (200 megabytes) is available for download here.

Icebreaking in Whitefish Bay on Lake Superior

March 24th, 2018 |

GOES-16 ABI Band 2 “Red” (0.64 µm) Visible imagery, 2202 UTC on 22 and 23 March 2018 (Click to enlarge)

Dan Miller, the Science and Operations Officer (SOO) in Duluth sent the imagery above. Constant icebreaking has been ongoing on Whitefish Bay prior to the opening of the SOO Locks this weekend. A faint black line representing open water is apparent in the 22 March imagery, and it’s even more apparent in the 23 March imagery.

A toggle below, from 24 March 2018, shows the Band 2 “Red” (0.64 µm) Visible and the Band 5 “Snow/Ice” (1.61 µm) Near-Infrared images. The open water is apparent in both images — dark in contrast to the white snow and lake ice in the visible, darker than the adjacent ice in the 1.61 µm. Recall that horizontal resolution in Band 2 is 0.5 km at the sub-satellite point (nadir), and in Band 5 it is 1 km.

GOES-16 ABI Band 2 “Red” (0.64 µm) Visible and Band 5 “Snow/Ice” (1.61 µm) near-infrared imagery, 2202 UTC on 22 and 23 March 2018 (Click to enlarge)

Suomi NPP and NOAA-20 also viewed the icebroken path on 24 March, and favorable orbit geometry for NOAA-20 and Suomi NPP on 24 March (orbit paths from this site) meant 2 sequential passes from both satellites both viewed Whitefish Bay. The 4 images are shown in an animation below, with imagery from NOAA-20 first, then Suomi NPP (the labels all say Suomi NPP erroneously). Note that NOAA-20 data are provisional, non-operational, and undergoing testing still).

VIIRS Visible (0.64 µm) Imagery from NOAA-20 (1708, 1846 UTC) and Suomi-NPP (1756, 1937 UTC) on 24 March 2018 (Click to enlarge)

The break in the ice was also visible in Day Night Band Imagery from VIIRS at 0722 UTC (from NOAA-20) on 24 March 2018.  It is also apparent in the shortwave Infrared imagery from both GOES-16 (very subtly) and from VIIRS (which offers better spatial resolution).

The icebreaking track was also apparent on 250-meter resolution Terra MODIS True-color and False-color Red-Green-Blue (RGB) images from the MODIS Today site (below). In the False-color image, ice and snow (in areas of sparse vegetation) show up as shades of cyan.

Terra MODIS True-color and False-color RGB images [click to enlarge]

Terra MODIS True-color and False-color RGB images [click to enlarge]

Fires over the Texas Panhandle

March 23rd, 2018 |

GOES-16 ABI Shortwave Infrared imagery (3.9 µm), 1905-2058 UTC on 23 March 2018 (Click to animate)

The Storm Prediction Center issued an Extreme Fire Weather advisory for 23 March 2018, and a GOES-16 Mesoscale Sector (#2, from this site) was positioned over the High Plains of Texas to monitor.

The GOES-16 Shortwave Infrared imagery, above, from 1905-2058 UTC on 23 March 2018 shows rapid warming of pixels near Borger TX (KBGD), and then southeast of Borger and northeast of Amarillo (KAMA). Surface observations show gusty southwest winds and low dewpoints, ideal for fire. Under the cirrus shield to the south, decreased solar insolation meant less vertical mixing of dry air and high winds, so dewpoints were higher and winds were weaker, lessening the fire danger.

Note that missing pixels are apparent in the GOES-16 Shortwave IR imagery around 2010 UTC. Quality flags that highlight the extreme warmth of the pixel have been activated, and AWIPS data are reported as missing in those locations.

Visible imagery, both Band 1 (“Blue” Visible, 0.47 µm) and Band 2 (“Red” Visible, 0.64 µm) from the GOES-16 ABI, below, show visible smoke plumes starting around 1940 UTC for the fire near Borger, and closer to 2000 UTC for the fire southeast of Borger. The plumes appear in both visible bands at approximately the same time, although they are more distinct in the blue band because of the enhanced scattering in the atmosphere at that wavelength.

GOES-16 ABI “Blue” Visible imagery (0.47 µm), 1905-2058 UTC on 23 March 2018 (Click to animate)

GOES-16 ABI “Red” Visible imagery (0.64 µm), 1905-2058 UTC on 23 March 2018 (Click to animate)

A qualitative method of identifying fires is the Fire RGB that combines the shortwave IR (3.9 µm, the red component of the RGB) with the 2.2 µm (Green) and 1.6 µm (Blue) reflectance channels. As fires become progressively hotter, they emit more and more radiation at shorter wavelengths that can be detected by the ABI on GOES-16, and this alters the color of the RGB over the fire. The Fire RGB animation is shown below. When the 3.9 µm imagery is missing from AWIPS (2005 UTC, 2007-2011 UTC, 2015 UTC because the pixels are hot enough that quality control flags are activated, so the data are not shown), the red pixels in the Fire RGB turn green because no Red component is present (Click here to see the Fire RGB and Shortwave IR animated 2004-2016 UTC).

GOES-16 ABI Fire RGB imagery (3.9 µm, 2.2 µm, 1.6 µm), 1905-2058 UTC on 23 March 2018 (Click to animate)

There are Baseline products that allow a quantitative estimate of fire properties. The animation below shows the Mesoscale Domain Band 7 Shortwave Infrared (3.9 µm) imagery zoomed in over the Texas Panhandle, at 1-minute time-steps; superimposed on the imagery are the GOES-16 Fire Detection Fire Temperature pixels. Fire Products at present are not produced over Mesoscale Domains, so CONUS-scale Fire Products (produced every 5 minutes) are shown instead. The Fire Temperature product in this case has a signal before an obvious signal is present in the 3.9 µm signal — although that could be a function of the 3.9 µm enhancement used here.

An observant reader will notice that the pixels in the GOES-16 Fire Product do not align with the GOES-16 3.9 µm pixels. This is because of the double remapping in the GOES-16 ABI Bands that occurs at NESDIS before data are sent to AWIPS. The Baseline product is not doubly remapped at NESDIS. (This double remapping is being removed from the processing stream shortly).

GOES-16 ABI Shortwave Infrared imagery (3.9 µm), shown every minute, and the GOES-16 Fire Temperature Baseline Product, shown every 5 minutes, 1905-2014 UTC on 23 March 2018 (Click to animate)

This animation (from Pete Wolf, SOO in Jacksonville FL), shows a fast-moving fire in the Fire RGB a bit later.  The animation is from the CIRA Slider, similar to this link that shows an animation from 2045 UTC on 23 March to 0045 on 24 March.