Severe weather in Oklahoma, Texas and Louisiana

April 22nd, 2020 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed thunderstorms that produced a variety of severe weather (SPC Storm Reports) across far southern Oklahoma on 22 April 2020. These discrete supercell storms developed along a cold front associated with a low pressure system moving across the region (surface analyses).

GOES-16 Visible and Infrared images with plots of time-matched SPC Storm Reports are shown below.

GOES-16 "Red" Visible (0.64 µm, top) and "Clean" Infrared Window (10.35 µm, bottom) images, with plots of SPC Storm Reports [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm, top) and “Clean” Infrared Window (10.35 µm, bottom) images, with plots of SPC Storm Reports [click to play animation | MP4]

Farther to the southeast across eastern Texas, GOES-16 Visible and Infrared images (below) revealed a large and long-lived supercell thunderstorm that eventually moved eastward into Louisiana.

GOES-16 "Red" Visible (0.64 µm) and "Clean" Infrared Window (10.35 µm) images [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

GOES-16 Visible and Infrared images with plots of time-matched SPC Storm Reports are shown below. An Above-Anvil Cirrus Plume was produced by this thunderstorm, and cloud-top infrared brightness temperatures were as cold as -80ºC (violet pixels). Early in its life cycle, after dropping hail of 1.0-2.0 inches in diameter, the supercell produced the fatal EF-3 Onalaska tornado.

GOES-16 "Red" Visible (0.64 µm, top) and "Clean" Infrared Window (10.35 µm, bottom) images, with plots of SPC Storm Reports [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm, top) and “Clean” Infrared Window (10.35 µm, bottom) images, with plots of SPC Storm Reports [click to play animation | MP4]

A toggle between 1-km resolution NOAA-19 AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images at 2338 UTC (below) provided a more detailed view of the Above-Anvil Cirrus Plume. The coldest cloud-top infrared brightness temperature in the region of the overshooting top was -84.7ºC.

NOAA-19 AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images [click to enlarge]

NOAA-19 AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images [click to enlarge]

Additional imagery of these storms is available on the Satellite Liaison Blog.

Posted in AVHRR, GOES-16, POES, Severe convection | No Comments »

Bomb cyclone makes landfall along the Oregon/California coast

November 26th, 2019 |

GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images, with 3-hourly plots of surface fronts [click to play animation | MP4]

GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images, with surface fronts plotted in cyan and buoy locations plotted in red [click to play animation | MP4]

A sequence of GOES-17 (GOES-West) Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images (above) showed the evolution of a bomb cyclone (surface analyses: WPC | OPC) that made landfall along the Oregon/California coast just after sunset on 26 November 2019. The storm produced wind gusts of 106 mph in southwestern Oregon and 70 mph in northwestern California.

GOES-17 “Red” Visible (0.64 µm) images of the storm are shown below — the Mean Sea Level Pressure anomaly was 4-5 sigma below the climatological mean as the rapidly-deepening midlatitude cyclone made landfall. Similarly, 925 hPa wind speed anomaly was 3-5 sigma above the climatological mean. The system had transitioned to a warm seclusion phase by 00 UTC, as seen in a comparison of Visible and Water Vapor images at that time.

GOES-17 "Red" Visible (0.64 µm) images, with 3-hourly plots of surface fronts [click to play animation | MP4]

GOES-17 “Red” Visible (0.64 µm) images, with surface fronts plotted in cyan and buoy locations plotted in red [click to play animation | MP4]

A GOES-17 Mesoscale Domain Sector was positioned over the region, providing Visible images at 1-minute intervals (below).

GOES-17

GOES-17 “Red” Visible (0.64 µm) images, with hourly plots of surface wind barbs and gusts in knots [click to play animation | MP4]

A larger-scale view of the entire GOES-17 Mesoscale Domain Sector is shown below, using Visible images from the AOS site.

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-km resolution NOAA-15 AVHRR Shortwave Infrared (3.7 µm) imagery at 0217 UTC (below) showed the center of circulation just off the Oregon/California coast. At that time, winds were gusting to 50 knots at Crescent City, California (KCEC).

NOAA-15 AVHRR Shortwave Infrared (3.7 µm) image at 0217 UTC [click to enlarge]

NOAA-15 AVHRR Shortwave Infrared (3.7 µm) image at 0217 UTC, with plots of 02 UTC surface reports (cyan/yellow) and wind gusts (in knots, red) [click to enlarge]

A time series of surface data from Crescent City, California (below) showed the period when the air pressure dropped to 973.4 hPa (28.74 inches) — setting a new all-time low pressure record for the state of California. In addition, new low pressure records for the month of November were set at Medford, Oregon (981.4 hPa / 28.98 inches) and at Eureka, California (984.8 hPa / 29.08 inches).

Time series of surface data at Crescent City, California [click to enlarge]

Time series of surface data at Crescent City, California [click to enlarge]

Air pressure at the offshore buoy 8 miles NW of Crescent City (46027) dropped to 971.7 hPa (28.69 inches) at 0350 UTC (below).

Plots of Wind Speed (blue), Wind Gust (red) and Air Pressure (green) from Buoy 46027

Plots of Wind Speed (blue), Wind Gust (red) and Air Pressure (green) from Buoy 46027


Posted in AVHRR, GOES-17, POES | No Comments »

Thunderstorm over the Arctic Ocean

August 11th, 2019 |

NOAK49 PAFG 110400 CCA
PNSAFG
AKZ222-111600-

Public Information Statement…CORRECTED
National Weather Service Fairbanks AK
800 PM AKDT Sat Aug 10 2019

…Lightning Detected within 300 Miles of North Pole Today…

A number of lightning strikes were recorded between 4pm and 6pm
today within 300 miles of the North Pole. The lightning strikes
occurred near 85 degrees north, 120 degrees east, which is about
700 miles north of the Lena River Delta of Siberia. This lightning
was detected by the GLD lightning detection network which is used
by the National Weather Service. This is one of the furthest
north lightning strikes in Alaska Forecaster memory.

$$

JB

As noted by the NWS Fairbanks forecast office, lightning was detected with a thunderstorm located over the Arctic Ocean north of Siberia between 6-8 pm AKDT on 10 August (or 00-02 UTC on 11 August 2019). A sequence of AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images from NOAA-15 (at 2315 UTC), NOAA-19 (at 0100 UTC) and NOAA-15 (at 0232 UTC) (below) showed the eastward motion of this thunderstorm, which had developed in advance of a 500 hPa lobe of vorticity — the coldest cloud-top infrared brightness temperature associated with this feature was -49.9ºC (yellow enhancement) at 0100 UTC.

NOAA-19 AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images [click to enlarge]

AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images from NOAA-15 (at 2315 UTC), NOAA-19 (at 0100 UTC) and NOAA-15 (at 0232 UTC) [click to enlarge]



Posted in Arctic, AVHRR, Lightning, POES | No Comments »

Blowing dust in southern Nevada

April 9th, 2019 |

GOES-17 Split Window (10.3-12.3 µm), Split Cloud Top Phase (11.2-8.4 µm) and

GOES-17 Split Window (10.3-12.3 µm), Split Cloud Top Phase (11.2-8.4 µm) and “Red” Visible (0.64 µm) images [click to play animation | MP4]

GOES-17 (GOES-West) Split Window (10.3-12.3 µm), Split Cloud Top Phase (11.2-8.4 µm) and “Red” Visible (0.64 µm) images (above) displayed a plume of blowing dust — whose source region was a dry lake bed along the California-Nevada border — which developed in advance of an approaching cold front (surface analyses) and moved northeastward across far southern Nevada on 09 April 2019. Wind gusts of 50-65 mph were reported across the region.

This dust plume was also apparent over far southern Nevada in GOES-17 True Color Red-Green-Blue (RGB) images from the AOS site (below).

GOES-17 True Color RGB images [click to play animation | MP4]

GOES-17 True Color RGB images [click to play animation | MP4]

There are 5 airports located in the Las Vegas Valley, and GOES-17 images showed that the dust plume passed directly over Henderson (KHND) — time series plots of surface data from these sites (below) indicated that visibility was reduced to 3 miles at Henderson, with visibilities dropping to 8-9 miles at McCarran International Airport (KLAS) and Nellis Air Force Base (KLSV). The visibility was not impacted at the North Las Vegas Airport (KVGT), with its more northwest location being farther from the dust plume.

Time series plot of surface data at Henderson [click to enlarge]

Time series plot of surface data at Henderson [click to enlarge]

Time series plot of surface data at McCarran International Airport [click to enlarge]

Time series plot of surface data at McCarran International Airport [click to enlarge]

Time series plot of surface data at Nellis Air Force Base [click to enlarge]

Time series plot of surface data at Nellis Air Force Base [click to enlarge]

A notable exception was the Boulder City Municipal Airport (KBVU), which was downwind of a smaller local point source of blowing dust (Mursha Reservoir, another dry lake bed to the southwest) — the visibility at KBVU was restricted to 2 miles at times. With the 2-km spatial resolution (at satellite nadir) of the GOES-17 Infrared spectral bands, there was not a signature of this smaller-scale Boulder City dust plume in the 10.3-12.3 µm and 11.2-8.4 µm Brightness Temperature Difference products — however, this hazy plume was evident in the 0.5-km resolution (at satellite nadir) Visible imagery.

Time series plot of surface data at Boulder City Municipal Airport [click to enlarge]

Time series plot of surface data at Boulder City Municipal Airport [click to enlarge]

A comparison of 1-km resolution NOAA-19 AVHRR Visible (0.63 µm), Shortwave Infrared (3.8 µm) and Split Window (10.8-12.0 µm) images (below) provided a detailed view of the primary dust plume — and also exhibited a subtle signature of the smaller plume that reduced visibility at Boulder City KBVU. The small dust aerosols act as efficient reflectors of incoming solar radiation, therefore appearing warmer (darker) on the Shortwave Infrared image.

NOAA-19 AVHRR Visible (0.63 µm), Shortwave Infrared (3.8 µm) and Split Window (10.8-12.0 µm) images, with plots of 23 UTC surface reports [click to enlarge]

NOAA-19 AVHRR Visible (0.63 µm), Shortwave Infrared (3.8 µm) and Split Window (10.8-12.0 µm) images, with plots of 23 UTC surface reports [click to enlarge]

The GOES-17 and NOAA-19 images also showed that the larger dust plume moved across a section of Interstate 15 between Sloan and Jean; traffic cameras showed significant reductions in visibility along I-15 near Primm (along the California/Nevada border).

Posted in Air quality, AVHRR, GOES-17, POES, Red-Green-Blue (RGB) images | No Comments »

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