Contrails along the Florida coast

December 18th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm, top), Near-Infrared “Cirrus” (1.37 µm, middle) and Low-level Water Vapor (7.3 µm, bottom) images [click to play animation | MP4]

A pair of circular contrails was seen along the coast of the Florida Panhandle in GOES-16 (GOES-East) “Red” Visible (0.64 µm), Near-Infrared “Cirrus” (1.37 µm) and Low-level Water Vapor (7.3 µm) images (above) on 18 December 2018. The contrail features were moving eastward at speed of 50-60 knots.

GOES-16 Water Vapor weighting functions derived using 12 UTC rawinsonde data from Tallahassee, Florida (below) revealed significant contributions by radiation being sensed from levels peaking at either 424 hPa or 442 hPa with all 3 spectral bands — due to a shallow layer of mid-tropospheric moisture — with secondary higher-altitude weighting function peaks around the 300 hPa pressure level.

Water Vapor weighting functions derived using 12 UTC rawinsonde data from Tallahassee, Florida [click to enlarge]

GOES-16 Water Vapor weighting functions derived using 12 UTC rawinsonde data from Tallahassee, Florida [click to enlarge]

Wind speeds from 12 UTC Tallahassee rawinsonde data (below) were 50 knots or greater above the 300 hPa layer, which suggests the contrails existed near that level — and the increased moisture at that high altitude allowed the contrails to persist for nearly 2.5 hours before dissipating.

Plot of 12 UTC rawinsonde data from Tallahassee, Florida [click to enlarge]

Plot of 12 UTC rawinsonde data from Tallahassee, Florida [click to enlarge]

GOES-16 Infrared and Water Vapor winds (source) also showed wind speeds of 50 or greater at higher altitudes in the general vicinity of these contrail features (below).

GOES-16 Infrared and Water Vapor winds [click to play animation]

GOES-16 Infrared and Water Vapor winds [click to play animation]

Southern US storm, and a Tehuano wind event

December 15th, 2018 |

GOES-16 Low-level Water Vapor (7.3 µm) images, 13-15 December [click to play MP4 animation]

GOES-16 Low-level Water Vapor (7.3 µm) images, 13-15 December [click to play MP4 animation]

A large midlatitude cyclone moved from the southern High Plains to the Lower Mississippi Valley during the 13 December15 December 2018 period (surface analyses) — GOES-16 (GOES-East) Low-level Water Vapor (7.3 µm) images (above) showed the evolution of this system.

The corresponding GOES-16 Water Vapor images with plots of hourly surface wind gusts are shown below; peak wind gusts exceeding 50 knots occurred in parts of Colorado, New Mexico and Texas on 13 December.

GOES-16 Low-level Water Vapor (7.3 µm) images with hourly plots of surface wind gusts, 13-15 December [click to play MP4 animation]

GOES-16 Low-level Water Vapor (7.3 µm) images with hourly plots of surface wind gusts in knots, 13-15 December [click to play MP4 animation]

This event was unusually windy in South Texas and the Rio Grande Valley:

Another notable aspect of this storm was a very localized area of heavy snowfall just south of Sweetwater, Texas:


The remnant patch of snow cover was evident in VIIRS Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) imagery on 14 and 15 December (below). The heaviest snowfall occurred over an isolated ridge along the eastern edge of the Edwards Plateau, where elevations of 2500-2600 feet were about 500 feet higher than the adjacent rolling plains. Since snow is a very effective absorber of energy at the 1.61 µm wavelength, it appeared dark on the Snow/Ice imagery.

Topography, Suomi NPP VIIRS Visible (0.64 µm) and Near-Infrared "Snow/Ice" (1.61 µm) images on 14 December [click to enlarge]

Topography plus Suomi NPP VIIRS Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images on 14 December [click to enlarge]

Topography plus NOAA-20 VIIRS Visible (0.64 µm) and Near-Infrared "Snow/Ice" (1.61 µm) images on 15 December [click to enlarge]

Topography plus NOAA-20 VIIRS Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images on 15 December [click to enlarge]

The residual snow cover on 14 December was also seen in Terra/Aqua MODIS True Color and False Color Red-Green-Blue (RGB) images, viewed using RealEarth (below). The snow appeared as shades of cyan in the False Color images.

Terra/Aqua MODIS True Color and False Color images on 14 December [click to enlarge]

Terra/Aqua MODIS True Color and False Color images on 14 December [click to enlarge]

A toggle between Terra MODIS True Color RGB images on the late morning of 14 and 15 December (below) demonstrated the amount of snow melt in 24 hours.

Terra MODIS True Color RGB images on 14 and 15 December [click to enlarge]

Terra MODIS True Color RGB images on 14 and 15 December [click to enlarge]

The strong cold front associated with this storm moved rapidly southward across the western Gulf of Mexico on 14 December (surface analyses), crossing the terrain of the Isthmus of Tehuantepec in southern Mexico and emerging into the Gulf of Tehuantepec as a gap wind (known as a Tehuano wind). A curved rope cloud marking the leading edge of the Tehuano winds was evident on GOES-17 and GOES-16 “Red” Visible (0.64 µm) images (below).

* GOES-17 images shown here are preliminary and non-operational *

GOES-17 (left) and GOES-16 (right)

GOES-17 (left) and GOES-16 (right) “Red” Visible (0.64 µm) images [click to play animation | MP4]

A comparison of GOES-16 Visible imagery from 14 and 15 December (below) showed how far southwestward the gap winds spread out across the Pacific Ocean during those 2 days. Note that on 15 December there were ship reports with wind speeds of 50 knots, at 12 UTC and at 17 UTC.

GOES-16

GOES-16 “Red” Visible (0.64 µm) images with surface and ship reports, 14-15 December [click to play animation | MP4]

NOAA-20 VIIRS True Color RGB and Infrared Window (11.45 µm) images on 14 and 15 December (below) also showed the progression of the Tehuano wind rope cloud — the hazy signature of dust-laden air within the offshore flow was also apparent on the daytime True Color images.

NOAA-20 VIIRS True Color and Infrared Window (11.45 µm) images on 14 and 15 December [click to enlarge]

NOAA-20 VIIRS True Color RGB and Infrared Window (11.45 µm) images on 14 and 15 December [click to enlarge]

Metop-A and Metop-B ASCAT surface scatterometer winds across the western Gulf of Mexico [click to enlarge]

Metop-A and Metop-B ASCAT surface scatterometer winds across the western Gulf of Mexico [click to enlarge]

On 14 December, a sequence of EUMETSAT Metop-A and Metop-B ASCAT surface scatterometer winds (source) showed the cold front moving southward across the western Gulf of Mexico (above), and also showed the northerly gap wind flow just beginning to emerge into the Gulf of Tehuantepec around 1607 UTC (below).

Metop-A and Metop-B ASCAT surface scatterometer winds across the southern Gulf of Mexico and the Gulf of Tehuantepec [click to enlarge]

Metop-A and Metop-B ASCAT surface scatterometer winds across the far southern Gulf of Mexico and the Gulf of Tehuantepec [click to enlarge]

The plume of dry air being transported southwestward across the Pacific Ocean by the gap winds was apparent on MIMIC Total Precipitable Water images (below). The majority of this dry air was within the surface-850 hPa layer (21 UTC comparison).

MIMIC Total Precipitable Water product (Total column, and Surface-850 hPa layer) [click to play animation]

MIMIC Total Precipitable Water product (Total column, and Surface-850 hPa layer) [click to play animation]

GCOM-W1 AMSR2 microwave products

November 30th, 2018 |

GCOM-W! AMSR2 Total Precipitable Water and Wind Speed products, from 2256 UTC on 28 November to 1692 UTC on 30 November [click to play animation]

GCOM-W1 AMSR2 Total Precipitable Water and Wind Speed products, from 2256 UTC on 28 November to 1692 UTC on 30 November [click to play animation]

A series of GCOM-W1 AMSR2 swaths during the period from 2256 UTC on 28 November to 1692 UTC on 30 November 2018 (above) showed the global coverage of Total Precipitable Water and Wind Speed products from that polar-orbiting satellite.

GCOM-W1 AMSR2 Total Precipitable Water, Wind Speed, Surface Rain Rate and Cloud Liquid Water products [click to enlarge]

GCOM-W1 AMSR2 Total Precipitable Water, Wind Speed, Surface Rain Rate and Cloud Liquid Water products [click to enlarge]

A closer look just south of the Atlantic provinces of Canada (above) showed a comparison of Total Precipitable Water, Wind Speed, Surface Rain Rate and Cloud Liquid Water products over a strong mid-latitude cyclone at 0545 UTC on 29 November (the 0532 UTC time stamp on the images denotes the beginning time of that particular satellite swath).

Surface analyses from the OPC (below) classified this low pressure system as Hurricane Force at 00 UTC and Storm Force at 06 UTC — however, AMSR2 ocean surface wind speeds were as high as 71 knots west of the surface low, 84.8 knots north of the low and 95.6 knots in the vicinity of the occluded front.

Surface analyses at 00 UTC and 06 UTC [click to enlarge]

Surface analyses at 00 UTC and 06 UTC [click to enlarge]

Shortly after the overpass of GCOM-W1, additional views of the western portion of this storm were provided by Aqua MODIS and NOAA-20 VIIRS (below). (note: the NOAA-20 VIIRS images are incorrectly labeled as Suomi NPP)

Aqua MODIS Water Vapor (6.7 µm) and Infrared Window (11.0 µm) images at 0543 UTC [click to enlarge]

Aqua MODIS Water Vapor (6.7 µm) and Infrared Window (11.0 µm) images at 0543 UTC [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 0557 UTC [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 0557 UTC [click to enlarge]

Another overpass of GCOM-W1 about 10 hours later continued to show a broad region of strong post-frontal westerly winds to the south of the storm center (below). During that period, the occluded low continued to deepen from 957 to 952 hPa (surface analyses).

GCOM-W1 AMSR2 Total Precipitable Water, Wind Speed at 0532 and 1529 UTC [click to enlarge]

GCOM-W1 AMSR2 Total Precipitable Water and Wind Speed products at 0532 and 1529 UTC [click to enlarge]

Additional features seen in the AMSR2 Total Precipitable Water and Wind Speed products in other parts of the world included the following:

GCOM-W1 AMSR2 Total Precipitable Water and Wind Speed products at 0353 UTC on 29 November [click to enlarge]

GCOM-W1 AMSR2 Total Precipitable Water and Wind Speed products south of Iceland at 0353 UTC on 29 November [click to enlarge]

Low pressure south of Iceland (surface analyses), with an ocean surface wind speed of 76 knots (above).

GCOM-W1 AMSR2 Total Precipitable Water and Wind Speed products off the US West Coast at 1026 UTC on 29 November [click to enlarge]

GCOM-W1 AMSR2 Total Precipitable Water and Wind Speed products off the US West Coast at 1026 UTC on 29 November [click to enlarge]

Low pressure off the US West Coast (surface analyses), with an ocean surface wind speed of  70 knots (above).

GCOM-W1 AMSR2 Total Precipitable Water and Wind Speed products north of Hawai'i at 1202 UTC on 29 November [click to enlarge]

GCOM-W1 AMSR2 Total Precipitable Water and Wind Speed products north of Hawai’i at 1202 UTC on 29 November [click to enlarge]

Low pressure and a cold front northwest of Hawai’i (surface analysis), with a long fetch of tropical moisture and widespread ocean surface wind speeds of 60-70 knots (above).

GCOM-W1 AMSR2 Total Precipitable Water and Wind Speed products southwest of Australia at 1659 UTC on 29 November [click to enlarge]

GCOM-W1 AMSR2 Total Precipitable Water and Wind Speed products southwest of Australia at 1659 UTC on 29 November [click to enlarge]

Low pressure southwest of Australia, with an ocean surface wind speed of 47 knots (above).

GCOM-W1 AMSR2 Total Precipitable Water and Wind Speed products southeast of Argentina at 1659 UTC on 29 November [click to enlarge]

GCOM-W1 AMSR2 Total Precipitable Water and Wind Speed products southeast of Argentina at 1659 UTC on 29 November [click to enlarge]

Low preesure and a cold front southeast of Argentina, with TPW as high as 2.2 inches and an ocean surface wind speed of 58.6 knots (above).

GCOM-W1 AMSR2 Total Precipitable Water and Wind Speed products over the North Sea at 0259 UTC on 30 November [click to enlarge]

GCOM-W1 AMSR2 Total Precipitable Water and Wind Speed products over the Norwegian Sea at 0259 UTC on 30 November [click to enlarge]

Low pressure over the Norwegian Sea (surface analysis), with an ocean surface wind speed of 75 knots (above).

GCOM-W1 AMSR2 Total Precipitable Water and Wind Speed products over the Aleutian Islands at 1247 UTC on 30 November [click to enlarge]

GCOM-W1 AMSR2 Total Precipitable Water and Wind Speed products over the Aleutian Islands at 1247 UTC on 30 November [click to enlarge]

A plume of moisture and strong winds ahead of a low pressure and cold front (surface analysis) moving across the Aleutian Islands (above).

Due to the frequent overlap of polar-orbiting satellite swaths at high latitudes, some locations can have data coverage from numerous consecutive overpasses. The example below shows the Barents Sea — between 70-80º N latitude — during 7 consecutive swaths from 2256 UTC on 28 November to 0847 UTC on 29 November.

GCOM-W1 AMSR2 Total Precipitable Water and Wind Speed products over the Barents Sea from 2256 UTC on 28 November to 0847 UTC on 29 November [click to enlarge]

GCOM-W1 AMSR2 Total Precipitable Water and Wind Speed products over the Barents Sea from 2256 UTC on 28 November to 0847 UTC on 29 November [click to enlarge]

Blowing dust in the Arabian Sea

November 3rd, 2018 |

Sequence of daily True Color RGB images from Terra MODIS, Aqua MODIS and Suomi NPP VIIRS, covering the period 01-03 November [click to play animation]

Sequence of daily True Color RGB images from Terra MODIS, Aqua MODIS and Suomi NPP VIIRS, covering the period 01-03 November [click to play animation]

Strong winds across southern Iran and Pakistan were lofting plumes of blowing sand/dust offshore over the Gulf of Oman and the Arabian Sea during 01 November, 02 November and 03 November 2018 — a sequence of daily composites of True Color Red-Green-Blue (RGB) images from Terra MODIS, Aqua MODIS and Suomi NPP VIIRS from RealEarth (above) showed the increase in dust transport during that 3-day period.

A comparison of True Color RGB images from Terra MODIS, NOAA-20 VIIRS, Suomi NPP VIIRS and Aqua MODIS on 03 November is shown below.

Comparison of True Color RGB images from Terra MODIS, NOAA-20 VIIRS, Suomi NPP VIIRS and Aqua MODIS on 03 November [click to play animation]

Comparison of True Color RGB images from Terra MODIS, NOAA-20 VIIRS, Suomi NPP VIIRS and Aqua MODIS on 03 November [click to play animation]

Metop-A and Metop-B ASCAT data (source) showed surface wind speeds in the 20-25 knot range emerging from the coast where plumes of blowing dust were located (below).

Meop ASCAT surface scatteromete winds [click to enlarge]

Meop ASCAT surface scatteromete winds [click to enlarge]

EUMETSAT Meteosat-11 High Resolution Visible (0.8 µm) images from 02 November and 03 November (below) showed the daily evolution of the dust plumes.

Meteosat-11 Visible (0.8 µm) images [click to play animation | MP4]

Meteosat-11 Visible (0.8 µm) images on 02 November [click to play animation | MP4]

Meteosat-11 Visible (0.8 µm) images on 03 November [click to play animation | MP4]

Meteosat-11 Visible (0.8 µm) images on 03 November [click to play animation | MP4]