An outbreak of severe weather occurred across parts of the Mid-South, Ohio Valley and mid Mississippi Valley on 03 April 2018. A GOES-16 Mesoscale Sector provided images at 1-minute intervals — “Red” Visible (0.64 µm) images (above) and “Clean” Infrared Window (10.3 µm) images (below) include plots of SPC storm reports.

Looking farther to the southwest over parts of Texas, Louisiana and Arkansas, similar animations of 1-minute GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images are shown below.

NOAA/CIMSS ProbSevere All Hazards (Prob Hail, Prob Wind, Prob Tor) use during this event is discussed here.

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A cold front moving southward along the western Great Plains showed a distinct signature in GOES-16 Water Vapor Imagery.  The hourly animation above, with surface observations, shows the front in the Low-Level Water Vapor passing over stations where winds shift from westerly and southwesterly to strong northerly.  The feature is far more trackable in GOES-16 ABI Imagery with a 5-minute cadence as is typical over CONUS, as shown below for both low-level water vapor infrared imagery (Band 10, 7.34 µm) and upper-level water vapor infrared imagery (Band 8, 6.19 µm). The infrared imagery allowed a precise determination of when the cold front would reach a location. (In fact, because a GOES-16 Mesoscale Sector was placed over west Texas, the time of arrival could be observed down to the minute, as shown in this animation of the clean window (10.3 µm) infrared imagery from GOES-16).

Visible Imagery after sunrise (below) shows that some surface cloudiness was associated with this feature — but other parts were clear.

It is not common for surface features to appear in the Upper-Level Water Vapor Imagery, even when the surface is near 900 mb, as over the High Plains of west Texas. Weighting Functions show from which layers in the atmosphere energy detected by the satellite originates. The Weighting function from Amarillo TX at 1200 UTC on 3 April is shown below.  The low-level water vapor weighting function — shown in magenta — shows contributions from the surface, but the upper-level water vapor weighting function — shown in green, shows contributions ending about 200 mb above the surface, at around 700 mb.  A conclusion might be that the depth of the cold air quickly increases to around 200 mb behind the front.  Thus is can appear in the Upper-Level water vapor imagery.   The cold front passes Amarillo (here is a meteorogram) shortly before 1200 UTC (and before the Radiosonde was launched).  The radiosonde from Dodge City Kansas, however, at 1200 UTC, shows a cold layer about 200 mb thick.  (Here is the Amarillo Sounding for the same time;  it’s shown in the Weighting Function plot below as well).

Interpretation of water vapor imagery is simplified if you use information from weighting functions to understand the three-dimensional aspect of the water vapor imagery.

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Some remnant signatures of Winter could be seen on 01 April 2018 — the first were seen  on GOES-16 (GOES-East) GOES-16 “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice (1.61 µm) over North Dakota and South Dakota, in the form of snow cover and snow/ice on parts of the Missouri River (above). With the high April sun angle, the lesser snow cover over northern South Dakota melted rather quickly, and the southern edge of the deeper snow cover in southern North Dakota also receded during the day.

Farther to the east, the motion and breakup of ice in Green Bay was evident on GOES-16 “Red” Visible (0.64 µm)  images (below).

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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.

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.

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.

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!)

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.

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)

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.)

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.

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.

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