Hurricane Irma moves through the Florida Keys

September 10th, 2017 |

GOES-16 ABI Infrared Imagery from the Clean Window (10.3 µm), 0122-1342 UTC (Click to animate)

GOES-16 data posted on this page are preliminary, non-operational and are undergoing testing

GOES-16 Infrared Imagery, above, shows Hurricane Irma moving north on a wobbly path (displaying trochoidal motion) through the Florida Keys. The eye of the storm moved between Key West (surface data plot) and Marathon (surface data plot) around sunrise on 10 September. Also note the development of well-defined transverse banding well to the northwest and north of the storm center — a cloud signature often associated with high-altitude turbulence. (In addition, GOES-16 Infrared images during 09-10 September with plots of surface wind gusts in knots is available here). Irma is a storm increasingly affected by wind shear, as evidenced by the asymmetries in the upper level clouds. and as noted in the 1200 UTC 10 September 2017 Wind Shear analysis below (Source).

Wind shear (850-250 hPa) analysis, 1200 UTC 10 September, over GOES-13 Visible Imagery (0.64) (Click to enlarge)

 

Irma is being influenced by a mid-latitude system and is gradually starting the extended process of extratropical transition. The drying associated with the mid-latitude system is very apparent over the Gulf of Mexico in the animation of 6.95 µm (Mid-level Water Vapor) Infrared Imagery from GOES-16, below.

 

GOES-16 Mid-Level Water Vapor (6.95 µm) Infrared Imagery, 0230 -1445 UTC on 10 September 2017 (Click to animate)

MIMIC TPW, below (source), shows the convergence of residual Atlantic frontal moisture from the east (into northern Florida) and Hurricane Irma’s moisture fro the the Caribbean (into southern Florida) (Click to animate).

MIMIC Total Precipitable Water (Click to animate)

MIMIC Total Precipitable Water (Click to animate)

Suomi NPP overflew Irma at 0740 UTC on 10 September, and Day/Night Band Visible Imagery (0.70 µm) is toggled with Infrared Imagery (11.45 µm) over the eye, below.

Suomi NPP Imagery over the eye of Irma: Day/Night Band Visible (0.70 µm) and Infrared (11.45 µm), 0740 UTC on 10 September (Click to enlarge)

Suomi NPP Imagery: Day/Night Band Visible (0.70 µm) and Infrared (11.45 µm), 0740 UTC on 10 September (Click to enlarge)

During the subsequent daytime hours, VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images at 1855 UTC, below, showed the eye of Category 3 Hurricane Irma about 40 minutes prior to landfall at Marco Island, Florida.

Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images (Click to enlarge)

Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images (Click to enlarge)

 

A toggle through 6 different Suomi NPP Channels near the time of landfall (0.41 µm, 0.64 µm, 0.86 µm, 1.38 µm, 1.61 µm and 10.8 µm) is shown below.

Suomi NPP VIIRS Imagery at 1852 UTC on 10 September 2017: 0.41 µm, 0.64 µm, 0.86 µm, 1.38 µm, 1.61 µm and 10.8 µm) (Click to enlarge)

Pyrocumulonimbus clouds in British Columbia, Canada

August 12th, 2017 |

GOES-16 Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images, with hourly surface reports plotted in yellow [click to play animation]

GOES-16 Visible (0.64 µm, top) and Shortwave Infrared (3.9 µm, bottom) images, with hourly surface reports plotted in yellow [click to play animation]

* GOES-16 data posted on this page are preliminary, non-operational and are undergoing testing*

GOES-16 “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images (above) along with “Red” Visible and “Clean” Infrared Window (10.3 µm) images (below) showed the formation of 3 pyrocumulonimbus( pyroCb) clouds late in the evening on 12 August 2017, within the cluster of ongoing intense wildfires in British Columbia, Canada.

GOES-16 Visible (0.64 µm) and Infrared Window (10.3 µm) images, with hourly surface reports plotted in yellow [click to play animation]

GOES-16 Visible (0.64 µm, top) and Infrared Window (10.3 µm, bottom) images, with hourly surface reports plotted in yellow [click to play animation]

A toggle between NOAA-18 AVHRR Visible (0.63 µm), Near-Infrared (0.86 µm), Shortwave Infrared (3.9 µm) and Longwave Infrared Window (10.8 µm) images is shown below. The coldest cloud-top IR brightness temperature was -70º C (associated with the northernmost pyroCb).

NOAA-18 Visible (0.63 µm), Shortwave Infrared (3.9 µm) and Longwave Infrared Window (10.3 µm) images, with surface station plots in yellow [click to enlarge]

NOAA-18 Visible (0.63 µm), Shortwave Infrared (3.9 µm) and Longwave Infrared Window (10.3 µm) images, with surface station plots in yellow [click to enlarge]

In a daytime Suomi NPP VIIRS true-color Red/Green/Blue (RGB) image (from RealEarth) with VIIRS-detected fire locations plotted in red (below), a very large pall of exceptionally-dense smoke from the BC fires could be seen drifting northward as far as the Northwest Territories of Canada.

Suomi NPP VIIRS true-color image, with VIIRS-detected fire locations plotted in red [click to enlarge]

Suomi NPP VIIRS true-color image, with VIIRS-detected fire locations plotted in red [click to enlarge]

The Suomi NPP OMPS Aerosol Index (AI) product (below; courtesy of Colin Seftor, SSAI) displayed AI values as high as 17.18 within the thick BC fire smoke pall.

Suomi NPP OMPS Aerosol Index [click to enlarge]

Suomi NPP OMPS Aerosol Index [click to enlarge]

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

Suomi NPP OMPS Aerosol Index product [click to enlarge]

Suomi NPP OMPS Aerosol Index product [click to enlarge]

On 13 August, a maximum OMPS AI value of 39.91 was seen at around 21:13 UTC over the Northwest Territories of Canada (above) — according to Colin Seftor and Mike Fromm (NRL), this value surpassed the highest pyroCb-related AI value ever measured by TOMS or OMI (whose period of record began in 1979).

The north-northeastward transport of BC fire smoke — as well as a prominent increase in smoke from fires across northern Canada and the Prairies — was evident in an animation of daily composites of Suomi NPP VIIRS true-color images from 07-13 August (below).

Daily Suomi NPP VIIRS true-color image composites (07-13 August), with VIIRS-detected fire locations plotted in red [click to play animation]

Daily Suomi NPP VIIRS true-color image composites (07-13 August), with VIIRS-detected fire locations plotted in red [click to play animation]

Severe thunderstorms in the Northeast US

July 1st, 2017 |

* GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing *

As noted in the Tweet above from NWS Gray/Portland ME, a record number of tornado warnings were issued by that office on 01 July 2017. According to their damage surveys, the tornadoes were rated EF-0 to EF-1, with some straight-line wind damage also seen. GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images with plots of SPC storm reports (below; also available as a 98-Mbyte animated GIF) displayed the overshooting tops and colder cloud-top infrared brightness temperatures associated with some of the thunderstorms. Note the significant offset between cloud-top features and storm reports — this is due to parallax from the large viewing angle of the GOES-16 satellite (which is positioned over the Equator at 105º West longitude).

GOES-16 Visible (0.64 µm, top) and Infrared Window (10.3 µm, bottom) images, with plots of SPC storm reports in red on Visible, and in black on Infrared [click to play MP4 animation]

GOES-16 Visible (0.64 µm, top) and Infrared Window (10.3 µm, bottom) images, with plots of SPC storm reports in red on Visible, and in black on Infrared [click to play MP4 animation]

A comparison of Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images at 1744 UTC (below) showed the early stages of convective development in far southwestern Maine, in addition to well-developed thunderstorms in eastern New York (which would later move northeastward to produce a swath of heavy rainfall that caused flooding at some locations).

Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11..45 µm) images [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11..45 µm) images [click to enlarge]

Thunderstorm development was fueled by high amounts of moisture that had moved into the Northeast US, as shown below by the Blended Total Precipitable Water product (values in the 40-50 mm or 1.6-2.0 inch range) and the Blended Total Precipitable Water Percent of Normal product (with values in excess of 200%).

Blended Total Precipitable Water product [click to enlarge]

Blended Total Precipitable Water product [click to enlarge]

Blended Total Precipitable Water Percent of Normal product [click to enlarge]

Blended Total Precipitable Water Percent of Normal product [click to enlarge]

The hourly evolution of moisture was depicted by the MIMIC Total Precipitable Water product (below).

MIMIC Total Precipitable Water product [click to play animation]

MIMIC Total Precipitable Water product [click to play animation]

Tropical Storm Bret

June 19th, 2017 |

GOES-16 “Veggie” Band (0.86 µm) animation of Tropical Storm Bret, 1545-2030 UTC on 19 June 2017 (Click to animate)

GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing.

The fast-moving tropical system in the southern Caribbean Sea has developed a closed circulation and has been named Bret.  Tropical Storm Bret, shown above in an animation of GOES-16 Near-Infrared (0.86 µm) imagery that highlights land/water contrasts (the Orinoco River in Venezuela and Caribbean Islands — some with cloud streamers in their lee — north of Venezuela stand out clearly), is forecast to remain very close to the South American coastline.  Such proximity to land will likely hinder development. Further, wind shear in the atmosphere over the storm is predicted to increase.

Bret is embedded within a ribbon of very moist air (associated with the ITCZ) that stretches from Africa to the northwest Caribbean, as shown in the animation below (taken from this site) that shows morphed microwave observations of total precipitable water.

Microwave estimates of Total Precipitable Water for the 24 hours ending 1900 UTC on 19 June 2017 (Click to enlarge)

For more information on Bret, refer to the National Hurricane Center and the CIMSS Tropical Cyclones sites (where you can also follow the future of the system emerging into the Gulf of Mexico).