Lake effect snow in Nevada

February 21st, 2019 |


GOES-17

GOES-17 “Clean” Infrared Window (10.3 µm) images [click to play animation | MP4]

GOES-17 (GOES-West) “Clean” Infrared Window (10.3 µm) images (above) showed an unusual lake effect snow feature downwind of Pyramid Lake in northwestern Nevada on 21 February 2019 — the surface visibility dropped to 0.5 mile with moderate snow as ihe lake effect cloud moved over Reno-Tahoe International Airport around 16 UTC. Prior to that, the lake effect snow also affected portions of Interstate 80 in the Patrick area.

A morning overpass of the NOAA-19 satellite provided a 1-km resolution Infrared Window (10.8 µm) image of the lake effect cloud at 1254 UTC (below). The coldest cloud-top infrared brightness temperature on that image was -46ºC.

NOAA-19 AVHRR Infrared Window (10.8 µm) image at 1254 UTC [click to enlarge]

NOAA-19 AVHRR Infrared Window (10.8 µm) image at 1254 UTC [click to enlarge]

GOES-17 cloud-top infrared brightness temperatures associated with this feature were as cold as -47ºC just after 15 UTC, which were very close to the tropopause temperature of -47.9ºC on 12 UTC rawinsonde data from Reno (below).

Plot of 12 UTC rawinsonde data from Reno, Nevada [click to enlarge]

Plot of 12 UTC rawinsonde data from Reno, Nevada [click to enlarge]

Although clouds often prevented a good view of Lake Pyramid, Terra MODIS Sea Surface Temperature values of 42º and 43ºF were sampled on 11 and 16 February (below). With a northerly flow of air having temperatures around 20ºF across such warm water, significant boundary layer instability was generated to aid the growth of the lake effect cloud feature.

Terra MODIS Sea Surface Temperature product on 11 and 16 February [click to enlarge]

Terra MODIS Sea Surface Temperature product on 11 and 16 February [click to enlarge]

Although the view angle from GOES-16 (GOES-East) was rather large, a Land Surface Temperature pixel mapped to the northern portion of the lake had a value of 39.3ºF at 1701 UTC (below).

GOES-16 Land Surface Temperature product at 1701 UTC [click to enlarge]

GOES-16 Land Surface Temperature product at 1701 UTC [click to enlarge]

Moisture Streaming towards Southern California

February 14th, 2019 |

Morphed Microwave Total Precipitable Water, 1800 UTC 13 February to 1700 UTC 14 February 2019 (Click to enlarge)

A potent Atmospheric River is affecting the California Coast on 14 February 2019. The morphed microwave imagery, above (from this site), shows rich moisture from deep in the tropics moving onto the southern California and northwest Mexican coasts.  The animation below shows the Layered Precipitable water — also a product derived from microwave imagery — for the same time period, but at 3-hour time steps (from this site).  An interesting feature is that the 850-700 hPa moisture layer is not as continuous back to the tropics as the other 3 layers.

Advected Layer Precipitable Water, 18z 13 February to 18z 14 February 2019 (Click to enlarge)

You can also infer a large influx of moisture from the low-level water vapor imagery, as shown in the short animation below from GOES-17, from 1617 UTC (just as Loop Heat Pipe issues that cause missing data were ramping down) to 1857 UTC. One might also infer a long-duration event from this animation!

GOES-17 ABI Band 10 Infrared 7.3 µm Imagery (Low-Level Water Vapor Band) from 1617 UTC to 1857 UTC on 14 February 2019 (Click to animate)

The GOES-R All-Sky Total Precipitable Water product (from this site) is as yet produced only from GOES-16 data (The Loop Heat Pipe problems have a strong impact on all Baseline products, including Legacy Profiles that are used to create Total Precipitable Water, which impact is still under investigation). The western Pacific is on the limb of this product, but it does capture the deep moisture moving towards southern California.

GOES-16 All-Sky Total Precipitable Water, 1400 UTC on 14 February 2019 (Click to enlarge)

Much of the San Diego National Weather Service Forecast Office County Warning Area is under Flood and/or Wind Warnings! See the Screen Capture below from 1121 AM Pacific Standard Time.

Warnings (as of 11:21 AM PDT on 14 February 2019) over the San Diego County Warning Area (Click to enlarge)

Rope cloud in the East Pacific Ocean

January 16th, 2019 |
GOES-17

GOES-17 “Red” Visible (0.64 µm) image, with an overlay of the 12 UTC surface analysis [click to enlarge]

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

An 1802 UTC GOES-17 “Red” Visible (0.64 µm) image with an overlay of the 12 UTC surface analysis (above) revealed a well-defined rope cloud which stretched for nearly 1000 miles, marking the cold front position at the time of the image. Rope clouds can therefore be used to diagnose the exact location of the leading edge of a cold frontal boundary between times when surface analyses are available. In this case, the cold front was associated with a Hurricane Force low over the East Pacific Ocean on 16 January 2019 (surface analyses).

GOES-17 "Red" Visible (0.64 µm) images [click to play animation]

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

An animation of GOES-17 Visible images is shown above, with a zoomed-in version closer to the rope cloud displayed below.

GOES-17 "Red" Visible (0.64 µm) images [click to play animation]

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

An even closer look (below) showed that the rope cloud was only about 2-3 miles wide.

GOES-17 "Red" Visible (0.64 µm) images [click to enlarge]

GOES-17 “Red” Visible (0.64 µm) images [click to enlarge]

When the 18 UTC surface analysis later became available, a close-up comparison with the 1802 UTC GOES-17 Visible image (below) indicated that the northern portion of the cold front (as indicated by the rope cloud) was slightly ahead of — and the southern portion slightly behind — the smoothed cold frontal position of the surface analysis product.

1802 UTC GOES-17 "Red" Visible (0.64 µm) image, with an overlay of the 18 UTC surface analysis [click to enlarge]

1802 UTC GOES-17 “Red” Visible (0.64 µm) image, with an overlay of the 18 UTC surface analysis [click to enlarge]

NOAA-15 AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images at 1617 UTC [click to enlarge]

NOAA-15 AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images at 1617 UTC [click to enlarge]

1-km resolution AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images of the rope cloud were captured by NOAA-15 at 1617 UTC (above) and by NOAA-18 at 1710 UTC (below). Along the northeastern portion of the rope cloud, there were a few convective clouds which exhibited cloud-top infrared brightness temperatures as cold as -55 to -60ºC (darker shades of red) and were tall enough to be casting shadows due to the low morning sun angle.

NOAA-18 AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images [click to enlarge]

NOAA-18 AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images at 1710 UTC [click to enlarge]


===== 17 January Update =====

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

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

On the following day, another rope cloud (one that was more fractured) was seen moving across Hawai’i as a cold front passed the island of Kaua’i — the southeastward progression of the rope cloud was evident on GOES-17 True Color Red-Green-Blue (RGB) images (above)  from the UW AOS site.

Surface observations plotted on GOES-17 Visible images (below) showed the wind shift from southwest to north as the cold front moved through Lihue on Kauwa’i around 00 UTC.

GOES-17

GOES-17 “Red” Visible (0.64 µm) images, with plots of surface reports [click to play animation | MP4]

===== 18 January Update =====

Suomi NPP VIIRS Day/Night Band (0.7 µm) image, with and without buoy observations [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) image, with and without buoy observations [click to enlarge]

Not all rope clouds are associated with cold fronts; with ample illumination from the Moon — in the Waxing Gibbous phase, at 90% of Full — a Suomi NPP VIIRS Day/Night Band (0.7 µm) image (above) provided a “visible image at night” of a rope cloud in the northern Gulf of Mexico which highlighted a surface wind shift axis.

A sequence of VIIRS Day/Night Band images from NOAA-20 and Suomi NPP (below) showed the movement of the rope cloud during a time span of about 1.5 hours.

NOAA-20 and Suomi NPP VIIRS Day/Night Band (0.7 µm) images [click to enlarge]

NOAA-20 and Suomi NPP VIIRS Day/Night Band (0.7 µm) images [click to enlarge]

Camp Fire in northern California

November 8th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm, top left), Shortwave Infrared (3.9 µm, top right), “Clean” Infrared Window (10.3 µm, bottom left) and Fire Temperature (bottom right) [click to play animation | MP4]

The Camp Fire started around 1433 UTC or 6:33 AM local time on 08 November 2018 in Northern California; the rapid spread of the fire prompted evacuations and forced road closures. GOES-16 (GOES-East) GOES-16 “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm), “Clean” Infrared Window (10.3 µm) and Fire Temperature (above) showed the initial evolution of the fire at 5-minute intervals — especially noteworthy were (1) the rapid vertical jump of the smoke column at 1547 UTC, which cast a long shadow to the northwest, and (2) Fire Temperature values that exceeded 2000 K (bright red pixels) at numerous times, with a maximum value just over 2300 K.

A GOES-16 Mesoscale Domain Sector was positioned over California beginning at 2115 UTC, providing imagery at 1-minute intervals — a comparison of Visible and Shortwave Infrared images (below) showed how quickly the hot thermal signature of the fire (yellow to red enhancement) advanced southwestward during the remaining 3 hours of daylight. Just northwest of the fire, Chico (station identifier KCIC) reported very low relative humidity values (6% at 21 UTC), as seen by the large spread between temperature and dewpoint late in the day.

GOES-16

GOES-16 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play MP4 animation]

1-km resolution NOAA-18 AVHRR Visible (0.64 µm), Near-Infrared “Vegetation” (0.86 µm), Shortwave Infrared (3.7 µm) and Infrared Window (10.8 µm) images (below) showed the bifurcation of the smoke plume as well as the large, very hot thermal signature of the fire at 1712 UTC or 9:12 AM local time.

NOAA-18 AVHRR Visible (0.64 µm), Near-Infrared "Vegetation" (0.86 µm), Shortwave Infrared (3.7 µm) and Infrared Window (10.8 µµ) images [click to enlarge]

NOAA-18 AVHRR Visible (0.64 µm), Near-Infrared “Vegetation” (0.86 µm), Shortwave Infrared (3.7 µm) and Infrared Window (10.8 µm) images [click to enlarge]

NOAA-20 Visible (0.64 µm), Near-Infrared

NOAA-20 VIIRS Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Higher spatial resolution views were provided by NOAA-20 VIIRS Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm) and Infrared Window (11.45 µm) images (above) and by Aqua MODIS Visible (0.65 µm), Near-Infrared “Snow/Ice” (1.61 µm) and Infrared Window (11.0 µm) images (below). [Note: the NOAA-20 VIIRS images are incorrectly labeled as Suomi NPP]

Aqua MODIS Visible (0.65 µm), Near-Infrared

Aqua MODIS Visible (0.65 µm), Near-Infrared “Snow/Ice” (1.61 µm) and Infrared Window (11.0 µm) images [click to enlarge]

Alternative views of the NOAA-20 VIIRS and Aqua MODIS images are shown below (using legacy AWIPS-1).They include Shortwave Infrared images from the 2 satellites, which reveal the very large (approximately 10 miles in length) thermal anomaly or fire “hot spot”. Due to the very dry atmosphere over the region (MODIS 6.7 µm Water Vapor image), the smoke could be clearly seen on the MODIS 1.37 µm Cirrus image (since there was very little attenuation of upwelling 1.37 µm radiation by middle/upper-tropospheric water vapor).

NOAA-20 Visible (0.64 µm), Day/Night Band (0.7 µm), Near-Infrared "Snow/Ice" (1.61 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images [click to enlarge]

NOAA-20 Visible (0.64 µm), Day/Night Band (0.7 µm), Near-Infrared “Snow/Ice” (1.61 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Aqua MODIS Visible (0.65 µm), Near-Infrared "Cirrus" (1.37 µm), Near-Infrared "Snow/Ice" (1.61 µm), Shortwave Infrared (3.7 µm) and Infrared Window (11.0 µm) images [click to enlarge]

Aqua MODIS Visible (0.65 µm), Near-Infrared “Cirrus” (1.37 µm), Near-Infrared “Snow/Ice” (1.61 µm), Shortwave Infrared (3.7 µm) and Infrared Window (11.0 µm) images [click to enlarge]

As a result of the unusual dryness air mass across the region, the 00 UTC Oakland sounding set a record low Total Precipitable Water value for the date (3 mm or 0.12 inch):

 

The Aqua MODIS Total Precipitable Water product at 2123 UTC (below) showed widespread values in the 3-5 mm range (darker shades of brown) over much or northern California. 12 hours later, the TPW value from the 12 UTC Oakland sounding was slightly lower (2.9 mm or 0.11 inch) — and the MODIS TPW product at 0921 UTC continued to show widespread dry air over California.

Aqua MODIS Total Precipitable Water product and Visible (0.65 µm) image at 2123 UTC [click to enlarge]

Aqua MODIS Total Precipitable Water product and Visible (0.65 µm) image at 2123 UTC [click to enlarge]

True Color Red-Green-Blue (RGB) imagery from NOAA-20 VIIRS (below) provided a good view of the smoke.

NOAA-20 VIIRS True Color RGB image [click to enlarge]

NOAA-20 VIIRS True Color RGB image [click to enlarge]

A NOAA-15 AVHRR Shortwave Infrared image at 0225 UTC or 6:25 PM local time (below) depicted the very large thermal anomaly of the fire.

NOAA-15 AVHRR Shortwave Infrared (3.7 µm) image; major highways are plotted in cyan, with Interstate highways plotted in red [click to enlarge]

NOAA-15 AVHRR Shortwave Infrared (3.7 µm) image; major highways are plotted in cyan, with Interstate highways plotted in red [click to enlarge]

The smoke had an adverse  impact on air quality over 100 miles from the fire source: the surface visibility dropped to 1 mile at Santa Rosa KSTS and 2 miles at San Francisco International Airport KSFO (below).

Time series of surface observations for Santa Rosa [click to enlarge]

Time series of surface observations from Santa Rosa [click to enlarge]

Time series of surface observations from San Francisco International Airport [click to enlarge]

Time series of surface observations from San Francisco International Airport [click to enlarge]

===== 09 November Update =====

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images [click to enlarge]

Nighttime VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images from NOAA-20 at 0849 UTC (above) and Suomi NPP at 0942 UTC (below) revealed the bright glow and the large, hot thermal anomaly of the Camp Fire.

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images [click to enlarge]

VIIRS True Color RGB images from Suomi NPP at 2104 UTC and NOAA-20 at 2154 UTC (below) showed the broad extent of the smoke from the Camp Fire in northern California as well as the Woolsey Fire in southern California. These images were captured and processed by the CIMSS/SSEC Direct Broadcast ground station.

Suomi NPP VIIRS True Color RGB image at 2104 UTC [click to enlarge]

Suomi NPP VIIRS True Color RGB image at 2104 UTC [click to enlarge]

NOAA-20 VIIRS True Color RGB image at 2154 UTC [click to enlarge]

NOAA-20 VIIRS True Color RGB image at 2154 UTC [click to enlarge]

An animation of 1-minute GOES-16 Visible and Shortwave Infrared images (below) revealed several plume jumps over the fire source from 15-19 UTC — and toward the end of the day, a decrease in the areal coverage and intensity of hot pixels indicated that extreme fire conditions were easing and containment efforts were slowing the spread of the fire.

GOES-16 "Red" Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play MP4 animation]

GOES-16 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play MP4 animation]

Abnormally dry to extreme drought conditions across California were a contributing factor to this and other wildfires across the state.

US Drought Monitor conditions as of 06 November [click to enlarge]

US Drought Monitor conditions as of 06 November [click to enlarge]

 

 

 

 

====== 11 November Update =====

Suomi NPP VIIRS Shortwave Infrared (3.74 µm) images [click to play animation]

Suomi NPP VIIRS Shortwave Infrared (3.74 µm) images [click to play animation]

A sequence of Suomi NPP VIIRS Shortwave Infrared (3.74 µm) images centered at Paradise, California viewed using RealEarth (above) showed the spread of the Camp Fire thermal anomaly (dark black pixels) during the period 1943 UTC on 08 November to 1046 UTC on 11 November.

1-minute GOES-16 Visible and Shortwave Infrared images (below) showed the development of new smoke plume and hot thermal signatures around the periphery of the ongoing Camp Fire during the day on 11 November. As of 1849 UTC (10:49 AM local time), the fire had burned 109,000 acres and was listed as 25% contained.

GOES-16 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play MP4 animation]

GOES-16 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play MP4 animation]

The new smoke plume — as well as residual smoke from previous days of burning — could be seen on VIIRS True Color RGB imagery from Suomi NPP at 2029 UTC and NOAA-20 at 2114 UTC (below). The entire image swaths as captured and processed by the Direct Broadcast ground station at CIMSS/SSEC can be seen here and here.

Suomi NPP VIIRS True Color RGB image at 2029 UTC [click to enlarge]

Suomi NPP VIIRS True Color RGB image at 2029 UTC [click to enlarge]

NOAA-20 VIIRS True Color RGB image at 2114 UTC [click to enlarge]

NOAA-20 VIIRS True Color RGB image at 2114 UTC [click to enlarge]

The Camp Fire claimed 85 lives, burned 153,000 acres and destroyed nearly 19,000 structures — making it both the deadliest and the most destructive wildfire on record for the state of California.