Large storm system over the western/central US

April 17th, 2016

GOES-14 Water Vapor (6.5 µm) images [click to play MP4 animation]

GOES-14 Water Vapor (6.5 µm) images [click to play MP4 animation]

GOES-14 Water Vapor (6.5 µm) images (above; also available as a large 85 Mbyte animated GIF) showed the development of a large upper-level closed low centered over the western US during the 15 April17 April 2016 period. This large storm system was responsible for a wide variety of weather, ranging from heavy snow and high winds in the Rocky Mountains to heavy rainfall and severe weather from eastern Colorado to Texas (SPC storm reports: 15 April | 16 April | 17 April).

Strong storm over the Upper Midwest and western Great Lakes

March 16th, 2016

GOES-13 Water Vapor (6.5 µm) images, with surface analyses [click to play animation]

GOES-13 Water Vapor (6.5 µm) images, with surface analyses [click to play animation]

A strong storm rapidly deepened as it moved northeastward across the Upper Midwest and western Great Lakes on 16 March 2016. GOES-13 Water Vapor (6.5 µm) images (above) showed the evolution of the system as the cloud shield expanded and became more elongated in a west-to-east orientation. On the previous day, this storm produced widespread hail and tornadoes from far eastern Iowa into northern and central Illinois (SPC storm reports).

A closer view of GOES-13 Visible (0.63 µm) images with METAR surface reports (below) revealed the strong winds caused by the tight pressure gradient — a peak wind gust of 61 mph was recorded at Waukesha in southeastern Wisconsin, with multiple power outages across the region caused by wind-related tree damage. Heavy rain (as much as 2-3 inches) produced some minor river flooding in various parts of Wisconsin; across northern Wisconsin, northeastern Minnesota, and the Upper Peninsula of Michigan the rain changed to snow, with as much as 18.5 inches accumulating at Redridge, Michigan, 13.0 inches at Lutsen, Minnesota, and 8.0 inches at Poplar and Sand Bay, Wisconsin. The weight of the wet snow was causing tree limbs to fall, with additional power outages being reported.

GOES-13 Visible (0.63 µm) images [click to play animation]

GOES-13 Visible (0.63 µm) images [click to play animation]

With the strong winds associated with this storm, there were also scattered pilot reports of moderate turbulence across the region, including 2 reports of severe turbulence over southern Wisconsin as seen below.

GOES-13 Water Vapor (6.5 µm) image, with pilot report of severe turbulence [click to enlarge]

GOES-13 Water Vapor (6.5 µm) image, with METAR surface reports and a pilot report of severe turbulence [click to enlarge]

GOES-13 Water Vapor image, with pilot report of severe turbulence [click to enlarge]

GOES-13 Water Vapor image, with METAR surface reports and a pilot report of severe turbulence [click to enlarge]

Landsat-8 Imagery

January 16th, 2016

Landsat-8 false-color image overpass [click to enlarge]

Landsat-8 false-color image overpass [click to enlarge]

Landsat-8 imagery — with a spatial resolution of 15 to 30 meters — is available for viewing via the SSEC RealEarth web map server. An example of a swath of false-color Red/Green/Blue (RGB) imagery across the central US between the times of 1630-1640 UTC on 16 January 2016 is shown above. Snow cover and ice (as well as ice crystal clouds) appear as varying shades of cyan in this type of RGB image.  Let’s take a closer look at 3 regions along this overpass to examine some interesting features.

The northerly flow of arctic air over the still-unfrozen waters of Lake Superior was aiding the development of lake effect snow (LES) bands, some of which were moving inland over the eastern portion of the Upper Peninsula of Michigan. One of the more well-defined LES bands was seen to be moving across the Grand Marais area — a cooperative observer 10 miles south of the city reported 8.5 inches of new snow during the 24-hour period from 12 UTC on 16 January to 12 UTC on 17 January.

Landsat-8 false-color RGB image over Lake Superior [click to enlarge]

Landsat-8 false-color RGB image over Lake Superior [click to enlarge]

Looking farther to the south, an interesting feature was seen in the southern part of ice-covered Green Bay, Wisconsin (below): a channel through the ice (red arrows) had been cut by the US Coast Guard icebreaker Mackinaw during the evening of 14 January, to allow passage for a ship to unload cargo at a dock along the mouth of the Fox River (which empties into the southern end of Green Bay). Hat tip to the NWS Green Bay for providing the information on which icebreaker was involved.

Landsat-8 Panchromatic Visible (0.59 µm) and False-color RGB images [click to enlarge]

Landsat-8 Panchromatic Visible (0.59 µm) and False-color RGB images [click to enlarge]

Finally, a look to the southern portion of the overpass: the Mississippi River, between the states of Louisiana and Mississippi. The Landsat satellites fly over the same portion of the Earth every 17 days, so taking advantage of this fact we can visualize the profound changes in the southern Mississippi River due to the flow of large amounts of water resulting from heavy rainfall farther to the north — over the Middle Mississippi River and Ohio River Valley regions — during December 2015 (as discussed in this blog post). Water appears as darker shades of blue in these particular Landsat RGB images, aiding in the identification of areas where flooding is occurring.

Landsat-8 false-color RGB images on 31 December 2015 and 16 January 2016 [click to enlarge]

Landsat-8 false-color RGB images on 31 December 2015 and 16 January 2016 [click to enlarge]

Flooding in the Missouri/Mississippi/Ohio River basins

January 2nd, 2016

Aqua MODIS false-color RGB images on 19 December 2015 and 02 January 2016 [click to enlarge]

Aqua MODIS false-color RGB images on 19 December 2015 and 02 January 2016 [click to enlarge]

A comparison of 250-meter resolution Aqua MODIS false-color Red/Green/Blue (RGB) images from the SSEC MODIS Today site on 19 December 2015 and 02 January 2016 (above) showed large increases in the width of portions of the Missouri/Mississippi/Ohio Rivers (as well as many of their tributaries and surrounding lakes) during that 14-day period. These false-color images use MODIS bands 7/2/1 as the R/G/B components — water appears as varying shades of darker blue. Some light snow cover (shades of cyan) can also be seen in the upper left corner of the 02 January image.

A comparison of Aqua MODIS true-color (created using bands 1/4/3) and false-color (created using bands 7/2/1) RGB images on 02 January (below) demonstrated the advantage of the false-color imagery for detection of the extent of river and lake flooding. The high sediment content of the area lakes and rivers made them appear as varying shades of tan to brown on the true-color image, making their boundaries more difficult to distinguish from the similar shades of the surrounding bare ground surfaces. (Note: when GOES-R is launched in late 2016, similar spectral bands on the ABI instrument will allow the creation of these types of true-color and false-color RGB images)

Aqua MODIS true-color and false-color RGB images on 02 January 2016 [click to enlarge]

Aqua MODIS true-color and false-color RGB images on 02 January 2016 [click to enlarge]

A more detailed view of flooding across the eastern portion of the MODIS images (in southern Indiana and northern Kentucky) was provided by 30-meter resolution Landsat-8 false-color imagery, as visualized using RealEarth (below). A magnified view of the Evansville, Indiana / Owensboro, Kentucky area can be seen here.

Landsat-8 false-color image [click to enlarge]

Landsat-8 false-color image [click to enlarge]

Maps of total observed precipitation and departure from normal (below) during the same 14-day period as the 2 MODIS false-color images shown at the top of the blog post revealed that widespread areas received upwards of 8-10 inches of rainfall, which was 6-8 inches above normal for that 2-week period of time.

19 December 2015 to 02 January 2016 total precipitation and departure from normal [click to enlarge]

19 December 2015 to 02 January 2016 total precipitation and departure from normal [click to enlarge]

As a result of water runoff from the heavy precipitation, new records for maximum river gauge height were set for the Mississippi River at Cape Girardeau, Missouri and Thebes, Illinois (below).

River gauge plot for the Mississippi River at Cape Girardeau, Missouri [click to enlarge]

River gauge plot for the Mississippi River at Cape Girardeau, Missouri [click to enlarge]

River gauge for the Mississippi River at Thebes, Illinois [click to enlarge]

River gauge for the Mississippi River at Thebes, Illinois [click to enlarge]

Additional information is available from the NWS Paducah.