Flooding in Louisiana

August 12th, 2016

Morphed MIRS observations of total precipitable water (TPW), 1500 UTC 11 August - 2100 UTC 12 August [click to play animation]

Morphed MIRS observations of total precipitable water (TPW), 1500 UTC 11 August – 2100 UTC 12 August [click to play animation]

Persistent convection in an atmosphere rich in moisture has led to life-threatening flooding over many Parishes in southern Louisiana. The animation above, taken from images at this site that morphs MIRS estimates of Total Precipitable Water (with values valid over both land and water) shows values around three inches over much of southeastern Louisiana. These TPW values agree with in situ observations such as the radiosonde from New Orleans at 1200 UTC on 12 August, where 2.70″ was observed. 24-hour rainfall totals ending at 1200 UTC on 12 August (Link) show a widespread region of more than 6″; raingauge observations of 6-hour totals at 1200 and 1800 UTC, below, show that the rain continued into the day on 12 August.

GOES-14 Visible (0.62 µm) images, with METAR observations of 6-hour precipitation, 1200 and 1800 UTC on 12 August 2016 [click to enlarge]

GOES-14 Visible (0.62 µm) images, with METAR observations of 6-hour precipitation, 1200 and 1800 UTC on 12 August 2016 [click to enlarge]

The flood-producing thunderstorms were very slow-moving, as evidenced in the animation of Infrared Window (10.7 µm) images from GOES-14, below (GOES-14 is in SRSO-R mode this month). Very little motion occurs in the two hours of this loop (using images at 5-minute time steps).

GOES-14 Infrared Window (10.7 µm) Imagery, 1625-1830 UTC on 12 August 2016 [click to play animation]

GOES-14 Infrared Window (10.7 µm) Imagery, 1625-1830 UTC on 12 August 2016 [click to play animation]

The entire sequence of 1-minute interval GOES-14 Infrared Window (10.7 µm) images from 0001-2358 UTC on 12 August is shown below.

GOES-14 Infrared Window (10.7 µm) images, with surface weather symbols plotted in yellow [click to play MP4 animation]

GOES-14 Infrared Window (10.7 µm) images, with surface weather symbols plotted in yellow [click to play MP4 animation]

This event is also discussed at the Satellite Liaison Blog, where the focus is on 1-minute visible imagery from GOES-14 and 1-minute lightning data.

===== 13 August Update =====

GOES-14 Infrared Window (10.7 µm) images, with hourly surface weather symbols plotted in yellow [click to play MP4 animation]

GOES-14 Infrared Window (10.7 µm) images, with hourly surface weather symbols plotted in yellow [click to play MP4 animation]

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).

GOES-14 SRSO-R: severe thunderstorms over North Dakota, South Dakota and Minnesota

August 10th, 2016

GOES-14 Visible (0.63 µm) images, with hourly surface reports and SPC storm reports of hail (yellow) and damaging winds (cyan) [click to play MP4 animation]

GOES-14 Visible (0.63 µm) images, with hourly surface reports and SPC storm reports of hail (yellow) and damaging winds (cyan) [click to play MP4 animation]

1-minute SRSO-R GOES-14 Visible (0.63 µm) images (above; also available as a 265 Mbyte animated GIF) showed the development of severe thunderstorms which produced large hail and damaging winds (SPC storm reports) in southeastern North Dakota, northeastern South Dakota and far western Minnesota on 10 August 2016. SPC noted a region of enhanced instability centered over southeastern North Dakota around 16 UTC (MCD); it is interesting to note that an orphan anvil was seen to form around 13 UTC between Valley City (KBAC) and Gwinner (KGWR) — near the northern edge of the pocket of instability — before the main convection began to develop just north of the North Dakota/South Dakota border around 1515 UTC.

GOES-14 is operating in SRSO-R Mode

August 9th, 2016

GOES-14 0.62 µm Visible images from 1230 to 1245 UTC on 9 August 2016 [click to play animation]

GOES-14 0.62 µm Visible images from 1230 to 1245 UTC on 9 August 2016 [click to play animation]

GOES-14 is in SRSO-R mode from today through 25 August, providing 1-minute imagery over western portions of the United States. The geographic footprint for 9 August 2016 is shown above (realtime images), and the 15-minute animation contains 13 images, versus the normal 2 that GOES-East or GOES-West would provide during routine scanning. This one-minute imagery is being provided to help prepare for GOES-R; GOES-R is scheduled to launch on 4 November, and when operational it will routinely provide 1-minute imagery in mesoscale sectors.

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-15 (left), GOES-14 (center and GOES-13 (right) Visible images [click to play animation]

GOES-15 (left), GOES-14 (center and GOES-13 (right) Visible images [click to play animation]

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.

GOES-14 Visible (0.62 µm) images [click to play animation]

GOES-14 Visible (0.62 µm) images [click to play animation]

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.

GOES-14 Visible (0.62 µm) images, with surface reports and SPC storm reports of hail (yellow) and wind (cyan) [click to play MP4 animation]

GOES-14 Visible (0.62 µm) images, with surface reports and SPC storm reports of hail (yellow) and wind (cyan) [click to play MP4 animation]

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.

GOES-13 (left), GOES-14 (center) and GOES-13 (right) 0.62 um Visible images [click to play MP4 animation]

GOES-13 (left), GOES-14 (center) and GOES-13 (right) 0.62 um Visible images [click to play MP4 animation]

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.

GOES-15 (left panels), GOES-14 (center panels) and GOES-13 (right panels) 0.62 m Visible and 3.9 µm Shortwave Infrared images [click to play animation]

GOES-15 (left panels), GOES-14 (center panels) and GOES-13 (right panels) 0.62 m Visible (top) and 3.9 µm Shortwave Infrared (bottom) images [click to play animation]

Hurricane Earl makes landfall in Belize

August 4th, 2016
GOES-14 10.7 µm Infrared Window images, hourly from 0115 through 1015 UTC on 4 August 2016 [click to play animation]

GOES-14 10.7 µm Infrared Window images, hourly from 0115 through 1015 UTC on 4 August 2016 [click to play animation]

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.

Metop-A ASCAT Scatterometer Winds, 0238 UTC 4 August 2016 [click to enlarge]

Metop-A ASCAT Scatterometer Winds, 0238 UTC 4 August 2016 [click to click to enlarge]

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.

Morphed MIRS Total Precipitable Water, 0600 UTC on 4 August 2016 [click to enlarge]

Morphed MIRS Total Precipitable Water, 0600 UTC on 4 August 2016 [click to click to enlarge]

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.

GOES-15, GOES-14, GOES-13 (left, center,right) Visible Imagery of Earl over Belize and Mexico, ~1200 UTC on 4 August 2016 [click to enlarge]

GOES-15, GOES-14, GOES-13 (left, center,right) Visible Imagery of Earl over Belize and Mexico, ~1200 UTC on 4 August 2016 [click to click to enlarge]

Two Geostationary Satellites viewing a system approximately equidistant from both satellites allowed for stereoscopic imagery to be created, below.

GOES-13 and GOES-14 Visible Imagery (0.62 µm), 1415 - 2115 UTC on 4 August 2016 [click to play animation]

GOES-13 and GOES-14 Visible Imagery (0.62 µm), 1415 – 2115 UTC on 4 August 2016 [click to play animation]