===== 13 August Update =====The heavy rainfall continued into 13 August, with storm total accumulations exceeding 31 inches in Louisiana (WPC storm summary). The entire sequence of 1-minute interval GOES-14 Infrared Window (10.7 µm) images spanning the period 1115 UTC on 11 August to 2159 UTC on 13 August, above, shows the development of multiple clusters of slow-moving thunderstorms, some of which exhibited cloud-top IR brightness temperatures of -80ºC or colder (violet color enhancement).
Shown below is a comparison of GOES-15 (GOES-West), GOES-14 and GOES-13 (GOES-East) Visible images covering the longer 1-hour period of 1230-1330 UTC, focusing on a area of thunderstorms over North Texas. During this time, there are 53 images from GOES-14, compared to 7 images from GOES-15 and 5 images from GOES-13 — note how the evolution of overshooting tops is very easy to follow using the 1-minute GOES-14 imagery.GOES-14 also monitored the dissipation of fog/low stratus clouds over Nebraska, as seen in the animation below. Additional details can be found here. Later in the day, the GOES-14 Visible (0.62 µm) animation below (also available as a large 62 Mbyte animated GIF) showed the development of severe thunderstorms in Montana and Wyoming, which produced several reports of damaging winds and large hail (up to 4.0 inches in diameter). This example is particularly noteworthy due to the fact that the storm was well-sampled by satellite imagery in a region of poor radar coverage (h/t to @DanLindsey77). For additional details on this case, see the VISIT Meteorological Interpretation Blog. A 3-panel comparison of Visible images from GOES-15 and GOES-13 (available at the routine 15-30 minute interval) and GOES-14 (available at 1-minute intervals) is shown below. During the early afternoon hours, the GOES-15 (GOES-West) satellite performed a “North/South Station Keeping maneuver”, during which there was no imaging between 1700-1900 UTC. To help cover for this outage, the GOES-13 (GOES-East) satellite was paced into Full Disk scan mode, which provided only 1 image every 30 minutes. During this time period, the 1-minute imagery from GOES-14 (shown below) was essential to monitor such features as a wildfire burning southeast of Ely, Nevada (station identifier KELY). Two apparent flare-ups of the fire were seen in the areal coverage of the hottest pixels (red) on GOES-14 Shortwave Infrared (3.9 µm) images at 1805 UTC and 1807 UTC, which were not captured by the 30-minute GOES-13 imagery. In fact, the 1745 UTC GOES-13 Shortwave Infrared image suggested that there was a brief reduction in the intensity of the fire (indicated by a lack of red pixels), which was not the case according to the 1-minute GOES-14 imagery.
Hurricane Earl made landfall around 0600 UTC on 4 August in Belize. The hourly animation from GOES-14, above, shows a rapid warming of the coldest cloud tops over Earl after landfall, as commonly happens. GOES-14 is out of storage to support SRSO-R Operations beginning Tuesday August 9.
The GOES-14 image at landfall shows coldest cloud tops on the north side of the storm. A timely Metop-A overpass (times available at this site) from several hours before landfall provided ASCAT winds, below, that also show strongest winds to the north side of this storm.Although the strong winds of Earl have diminished now that the storm is over land, Total Precipitable Water values, below, (showing MIRS data, available at this site) remain high and flooding continues to be a threat. Earl is forecast to move along the southern tip of the Bay Campeche starting tomorrow. For more details see the National Hurricane Center website. Three geostationary satellites viewed Earl as it moved across the southern Yucatan peninsula. GOES-15, GOES-14 and GOES-13 visible imagery from near 1200 UTC is shown below. Two Geostationary Satellites viewing a system approximately equidistant from both satellites allowed for stereoscopic imagery to be created, below.