Tropical Depression Flossie near Hawai’i

August 5th, 2019 |

GOES-17

GOES-17 “Red” Visible (0.64 µm), “Clean” Infrared Window (10.35 µm) and Upper-level Water Vapor (6.2 µm) images [click to play animation | MP4]

An animation that cycles through GOES-17 (GOES-West) “Red” Visible (0.64 µm), “Clean” Infrared Window (10.35 µm) and Upper-level Water Vapor (6.2 µm) images (above) showed Tropical Depression Flossie just northeast of Hawai’i on 05 August 2019. Note that (1) the exposed low-level circulation center (LLCC) was very apparent in the visible imagery, (2) deep convection offset to the east/northeast of the LLCC exhibited cloud-top infrared brightness temperatures as cold as -83ºC , and (3) a series of gravity waves were propagating westward away from the convection, moving toward Hawai’i.

GOES-15 Infrared imagery and deep-layer wind shear data from the CIMSS Tropical Cyclones site (below) showed that the tropical cyclone was in an environment of strong shear, which was responsible for the displacement between the exposed LLCC and the convection. In addition to the wind shear, the weakening trend of the system was also due to its motion over cold Sea Surface Temperatures and low Ocean Heat Content.

GOES-15 Infrared Window (10.7 µm) images, with contours and streamlines of deep-layer wind shear [click to enlarge]

GOES-15 Infrared Window (10.7 µm) images, with contours and streamlines of deep-layer wind shear at 18 UTC [click to enlarge]

Severe thunderstorms in the Dakotas, as viewed by 4 GOES

August 3rd, 2019 |

 

Visible images from GOES-17, GOES-15, GOES-14 and GOES-16, with SPC Storm Reports plotted in red [click to play animation | MP4]

Visible images from GOES-17, GOES-15, GOES-14 and GOES-16, with SPC Storm Reports plotted in red [click to play animation | MP4]

With GOES-14 undergoing its annual INR testing and evaluation, it afforded the ability to monitor features such as severe thunderstorms in the western Dakotas from 4 GOES — GOES-17 (GOES-West) at 137.2ºW, GOES-15 at 128ºW, GOES-14 at 105ºW and GOES-16 (GOES-East) at 75.2ºW longitude (above). These storms produced hail as large as 2.0 inches in diameter and damaging winds to 75 mph (SPC Storm Reports). The images are displayed in the native projection of each satellite.

NWS Juneau, Alaska issues their first-ever Severe Thunderstorm Warning — based on satellite imagery

June 27th, 2019 |

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

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

1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm) images (above) showed the development of thunderstorms over the far southern end of the Alaska Panhandle on 27 June 2019. These storms intensified as they moved southeastward toward the Misty Fjords area of Alaska (located east and southeast of Ketchikan PAKT) — and when a significant lightning jump was noted with the strongest storm, NWS Juneau issued their first-ever Severe Thunderstorm Warning at 0249 UTC. A few thunderstorm overshooting tops could be seen in the visible images (for example, at 0230 UTC).

The Severe Thunderstorm Warning polygon is shown below.

Severe Thunderstorm Warning polygon [click to enlarge]

Severe Thunderstorm Warning polygon [click to enlarge]

GOES-17 “Clean” Infrared Window (10.35 µm) images (below) revealed minimum cloud-top infrared brightness temperatures around -60ºC (darker red enhancement).

GOES-17 “Clean

GOES-17 “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

A comparison of GOES-17 “Red” Visible (0.64 µm) images at 1-minute intervals with GOES-15 Visible (0.63 µm) images at 15-30-minute intervals (below) helps to underscore the importance of 1-minute imagery for identifying and tracking the pulse-type of thunderstorms that developed on this day. Also evident is the brighter appearance of the GOES-17 Visible imagery — the ABI instrument on the newer GOES-R Series benefits from on-orbit visible calibration, which mitigates the visible detector degradation that plagued the older GOES series.

GOES-17

GOES-17 “Red” Visible (0.64 µm, left) and GOES-15 Visible (0.63 µm, right) images [click to play animation | MP4]

Additional information about this severe thunderstorm event is available on a FDTD GOES Applications Webinar.

On a side note, a larger-scale view of GOES-17 Visible imagery (below) showed a curious thin elongated feature moving southwestward from Yukon across the Alaska Panhandle to the Gulf of Alaska, which became more obvious later in the day as the lower sun angle increased forward scattering. This feature was casting a shadow onto the marine boundary layer stratus clouds over the Gulf of Alaska (0250 UTC image).

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

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

This feature was also apparent in GOES-17 Near-Infrared “Cirrus” (1.38 µm) images (below), since that spectral band excels at the detection of atmospheric particles that are efficient scatterers of light (such as cirrus ice crystals, dust, smoke and volcanic ash/sulfate). In fact, this was a streamer of high-altitude sulfate from the Raikoke eruption on 21 June — and this thin volcanic filament could be unambiguously identified earlier in Cirrus imagery than in Visible imagery (for example, over Yukon at 1950 UTC, before forward scattering became large enough to aid identification at visible wavelengths).

GOES-17 Near-Infrared “Cirrus” (1.38 µm) images [click to play animation | MP4]

GOES-17 Near-Infrared “Cirrus” (1.38 µm) images [click to play animation | MP4]

GOES-13 brought out of storage

June 21st, 2019 |

GOES-13 Visible (0.63 µm) images [click to play animation | MP4]

GOES-13 Visible (0.63 µm) images [click to play animation | MP4]

GOES-13 was taken out of storage on 19 June 2019 to begin a period of Image Navigation and Registration (INR) testing — the Satellite Data Services positioned a spare rooftop antenna to begin ingesting the GVAR data from the satellite (positioned over the Equator at 60.2º W longitude) . Visible images from 21 June are displayed above. According to NOAA: “With the established performance of NOAA’s new geostationary satellites, GOES-16 (as GOES-East) and GOES-17 (as GOES-West), and a healthy GOES-14 in reserve, NOAA can provide GOES-13 to the Air Force for their weather forecasting needs. After a check of the GOES-13 instruments, NOAA will operate the satellite on behalf of the Air Force during its remaining life span.”

A 5.5-hour animation of all five spectral bands of the GOES-13 Imager is shown below.

Images from all 5 spectral bands of the GOES-13 Imager [click to enlarge]

All 5 spectral bands of the GOES-13 Imager [click to enlarge | MP4]

Water Vapor images from GOES-17 (GOES-West), GOES-15, GOES-16 (GOES-East) and GOES-13 (below) — all centered at Glasgow, Montana — showed the development of an anomalously-deep (for 21 June) mid-tropospheric cutoff low over eastern Montana. The images are displayed in the native projection of each satellite.

Water Vapor images from GOES-17, GOES-15, GOES-16 and GOES-13, all centered at Glasgow, Montana [click to play animation | MP4]

Water Vapor images, from left to right: GOES-17, GOES-15, GOES-16 and GOES-13, all centered at Glasgow, Montana [click to play animation | MP4]

===== 25 June Update =====

All 5 spectral bands of the GOES-13 Imager [click to enlarge]

All 5 spectral bands of the GOES-13 Imager [click to enlarge]

A 23.5-hour animation of all five spectral bands of the GOES-13 Imager is shown above, centered over Wisconsin.

GOES-13 Visible (0.63 µm) images [click to play animation | MP4]

GOES-13 Visible (0.63 µm) images [click to play animation | MP4]

GOES-13 Visible images centered near Cape Verde in western Africa (above) showed that the INR quality of GOES-13 was still very good.

===== 26 June Update =====

GOES-13 Infrared Window (10.7 µm) and Visible (0.63 µm) images [click to play animation | MP4]

GOES-13 Infrared Window (10.7 µm) and Visible (0.63 µm) images [click to play animation | MP4]

A test of GOES-13 Rapid Scan Operations (RSO)was conducted on 26 June — a sequence of Infrared Window and Visible images (above) revealed the presence of a Mesoscale Convective Vortex (MCV) off the US East Coast, following the dissipation of its parent nocturnal thunderstorm.