Autumn tree colors

October 12th, 2015 |

Terra MODIS true-color image [click to enlarge]

Terra MODIS true-color image [click to enlarge]

A 250-meter resolution Terra MODIS true-color Red/Green/Blue (RGB) image from the SSEC MODIS Today site (above) revealed the widespread orange hue of Autumn tree colors over parts of northeastern Minnesota, northern Wisconsin, and the western Upper Peninsula of Michigan on 11 October 2015.

A comparison with the corresponding MODIS false-color RGB image (below) helped to identify 2 features of interest: (1) the large burn scar from the Pagami Creek fire in northeastern Minnesota (12 September 2011), and (2) the long tornado damage scar from the EF3 Langlade tornado in northeastern Wisconsin (07 June 2007). The location of these 2 features appears on this annotated image.

Terra MODIS true-color and false-color images [click to enlarge]

Terra MODIS true-color and false-color images [click to enlarge]

On the following day (12 October), the three MODIS true-color images below showed similar signatures of Autumn tree colors over portions of the Northeast US (SSEC MODIS Today).

Terra MODIS true-color image [click to enlarge]

Terra MODIS true-color image [click to enlarge]

Terra MODIS true-color image [click to enlarge]

Terra MODIS true-color image [click to enlarge]

Terra MODIS true-color image [click to enlarge]

Terra MODIS true-color image [click to enlarge]

The Autumn tree colors across the Northeast US were also evident on Suomi NPP VIIRS true-color imagery, as viewed using the SSEC RealEarth web map server (below).

Suomi NPP VIIRS true-color image [click to enlarge]

Suomi NPP VIIRS true-color image [click to enlarge]

Moisture from Central Pacific Hurricane Oho moving into British Columbia and Alaska

October 9th, 2015 |
GOES-15 Infrared Water Vapor (6.5 µm) Imagery, 0000 UTC 5 October through 0900 UTC 9 October 2015 [click to animate]

GOES-15 Infrared Water Vapor (6.5 µm) Imagery, 0000 UTC 5 October through 0900 UTC 9 October 2015 [click to animate]

The rocking animation* above shows central Pacific Hurricane Oho forming south of Hawai’i and then moving quickly northeast; moisture associated with the remains of the storm is now moving onshore in British Columbia and Alaska Southeast. It is unusual for central Pacific Hurricanes to influence directly the weather in the Pacific Northwest as Oho will (link). Because of the record number of central Pacific Hurricanes this year (in the satellite era at least), however, it’s perhaps not surprising that this is occurring.

The moisture is also trackable via microwave data as shown in the MIMIC Total Precipitable Water animation below.

MIMIC Total Precipitable Water for 72 hours ending 0700 UTC 09 October 2015 [click to enlarge]

MIMIC Total Precipitable Water for 72 hours ending 0700 UTC 09 October 2015 [click to enlarge]

Scatterometer winds from 0630 UTC (below) show a region of 40+-knot winds both in the warm sector of the storm and behind the cold front.

GOES-15 Water Vapor Imagery and ASCAT Scatterometer Winds, 0630 UTC on 9 October 2015 [click to enlarge]

GOES-15 Water Vapor Imagery and ASCAT Scatterometer Winds, 0630 UTC on 9 October 2015 [click to enlarge]

*You may notice some full disk imagery missing in this loop (at 0900 and 2100 UTC in the animation). At 2100 UTC the Sun is behind the ground antenna acquiring the data. This happens for a few days each year. The 0900 UTC imagery is missing because of GOES-15 Keep-Out Zone Operations.

Flooding in South Carolina

October 5th, 2015 |
Suomi NPP VIIRS Infrared (11.45 µm) and Day/Night Band Visible (0.70 µm) imagery overlain with 24-hour precipitation for the period ending 1200 UTC on 5 October [click to enlarge]

Suomi NPP VIIRS Infrared (11.45 µm) and Day/Night Band Visible (0.70 µm) imagery overlain with 24-hour precipitation for the period ending 1200 UTC on 5 October [click to enlarge]

Historic rainfalls associated with tropical moisture and a surface low pressure system inundated portions of South and North Carolina over the weekend. During the first four days of October, Charleston SC had 17+” of rain, Downtown Charleston had more than 16″, Columbia had 11″, Myrtle Beach had 14″. In fact, new records were set for greatest 1-day, 2-day, 3-day and 4-day rainfall at Charleston and Columbia (and storm-total rainfall amounts were as high as 26.88 inches in Charleston county;  click here for a YouTube video showing radar reflectivity from 1-6 October). The toggle above shows the Suomi NPP VIIRS Day/Night Band (with and without 24-hour precipitation totals ending 5 October, after the heaviest rain had moved north of Charleston) and Suomi NPP VIIRS 11.45 µm infrared imagery at 0630 UTC (2:30 am local time) — overshooting tops are evident within a band of strong convection offshore that was moving westward (inland) around the upper-level low pressure system located east of Jacksonville FL (as seen in the larger-scale version of the Day/Night Band image below).

Suomi NPP VIIRS Day/Night Band Visible (0.70 µm) Imagery, 0630 UTC 5 October 2015 with surface analysis [click to enlarge]

Suomi NPP VIIRS Day/Night Band Visible (0.70 µm) Imagery, 0630 UTC 5 October 2015 with surface analysis [click to enlarge]

The animation of GOES-13 10.7 µm Infrared imagery, below (click to view mp4 loop; very large animated gif file available here; a YouTube video of all GOES-13 RSO Infrared magery from 1-4 October is here), shows the evolution of the atmospheric flow pattern, from thunderstorms moving southwest-to-northeast along the coast on 1 October to thunderstorms moving directly inland, first from southeast-to-northwest late on 3 October and then to east/northeast-to-west/southwest along the coast at the end of the animation as an upper-level low developed east of Jacksonville. Multiple rounds of heavy rains occurred as the orientation of the rain bands pivoted, always overlapping South Carolina.

GOES-13 Infrared (10.7 µm) Imagery, 0015 UTC 1 October through 1145 UTC 5 October 2015 [click to animate]

GOES-13 Infrared (10.7 µm) Imagery, 0015 UTC 1 October through 1145 UTC 5 October 2015 [click to animate]

Much of the rain over Charleston fell between 0300 UTC on 3 October and 0700 UTC on 4 October, in two distinct events, as shown in the hourly GOES-13 Infrared image animation below. During the first bout of heavy rain that occurred late on the 2nd/early on the 3rd of October, cells moved over Charleston from the south; during the second bout of heavy rain, from the 3rd into the 4th, cells moved over Charleston from the southeast (this toggle of Total Precipitable Water from the GOES Sounder shows the convection offshore in regions of abundant moisture). The change in direction of cell motion was driven by the development of an upper-level low pressure system, as shown in the Water Vapor Imagery animation farther below. Both the thunderstorms over South Carolina and the thunderstorms supporting the evolution of Hurricane Joaquin benefited from the very moist tropical air mass that was over the Atlantic Ocean off southeast coast of the US.

GOES-13 Infrared (10.7 µm) Imagery, 0245 UTC 3 October through 0745 UTC 4 October 2015 [click to animate]

GOES-13 Infrared (10.7 µm) Imagery, 0245 UTC 3 October through 0745 UTC 4 October 2015 [click to animate]

GOES-13 Infrared Water Vapor (6.5 µm) Imagery, 0015 UTC 1 October through 1445 UTC 5 October 2015 [click to animate]

GOES-13 Infrared Water Vapor (6.5 µm) Imagery, 0015 UTC 1 October through 1445 UTC 5 October 2015 [click to animate]

A composite of the MIMIC Total Precipitable Water product and WSR-88D radar reflectivity visualized using SSEC RealEarth, below, showed how the offshore plume of high TPW became very narrow and focused on South Carolina during the 44-hour period from 18 UTC on 02 October to 14 UTC on 04 October.

MIMIC Total Precipitable Water product and Radar reflectivity [click to animate]

MIMIC Total Precipitable Water product and Radar reflectivity [click to animate]

Moisture moves inland over the Carolinas as Hurricane Joaquin moves through the Bahamas

October 2nd, 2015 |

METOP ASCAT Scatterometer Winds, 1356 UTC 2 October and GOES-13 Visible (0.63 µm) imagery [click to enlarge]

METOP ASCAT Scatterometer Winds, 1356 UTC 2 October and GOES-13 Visible (0.63 µm) imagery [click to enlarge]

Hurricane Joaquin moved slowly through the eastern Bahamas on 1 and 2 October 2015. ASCAT data from 1356 UTC, above, shows rain-flagged values near 90 knots not far from the storm center (Joaquin is a potent Category 4 Hurricane; its strongest winds are confined to within about 50 miles of the center).

MIMIC Total Precipitable Water for the 72 hours ending 1900 UTC on 2 October [click to enlarge]

MIMIC Total Precipitable Water for the 72 hours ending 1900 UTC on 2 October [click to enlarge]

Joaquin is embedded within a very moisture-rich environment, and that tropical moisture will move inland over the Carolinas and surrounding states over the weekend and produce heavy rains. The animation of MIMIC Total Precipitable Water, above, shows a corridor of very high total precipitable water just offshore of the Carolinas at the end of the animation, ready to shift inland.

Water Vapor Imagery, below, shows a strong trough over the northern Gulf of Mexico. This trough is serving to move Joaquin out of the Bahamas, and it will also serve as a potent precipitation producer on the East Coast. Percent-of-Normal plots from NESDIS’s Blended Precipitable Water product shows a large region of nearly 200% of normal over South Carolina, and greater than 200% of normal over North Carolina and regions north and east. Flood Watches have been issued from northeast Georgia to southern New Jersey.

GOES-13 Water Vapor Infrared Imagery (6.5 µm) and NESDIS Percent-of-Normal Blended Total Precipitable Water Product, 1745 UTC 2 October 2015 [click to enlarge]

GOES-13 Water Vapor Infrared Imagery (6.5 µm) and NESDIS Percent-of-Normal Blended Total Precipitable Water Product, 1745 UTC 2 October 2015 [click to enlarge]

For the latest information on Joaquin, consult the National Hurricane Center. Additional information is available at the CIMSS Tropical Cyclones site, and in a previous Blog Post.