GOES-12 water vapor images

GOES-12 water vapor images (with aircraft location)

Continental Flight 128, en route from Rio de Janiero to Houston on 3 August, encountered severe turbulence over the Atlantic Ocean just north of Hispaniola, according to AP Press reports. Other press reports suggest the turbulence occurred southeast of Puerto Rico (see this one from Bloomberg, for example), but flight tracking software available online shows a flight path that changed north of Hispaniola, presumably in response to the turbulence encountered. The aircraft landed in Miami at 5:30 EDT, or 0930 UTC; according to press reports, the turbulence was encountered an hour before that, or around 0830 UTC. [UPDATE: on-board flight logs (courtesy of John Williams at RAP at NCAR) suggest the flight path change, presumably right after the encounter with turbulence, occurred around 0800 UTC; that data has been superimposed on GOES-12 Imager water vapor (shown above) and window channel imagery (linked below)] What was happening in the satellite imagery at the time?

MIMIC Total Precipitable water shows that the region of turbulence was moistening with time as a tropical wave approached from the east. However, GOES-12 satellite data show only modest convection in the region. For example, the 6.7 micron water vapor imagery from 08:02 UTC shows only scattered convection, although the presence of developing deep convection very near the location of the turbulence to the north of Hispaniola suggests a strong correlation. A loop of the water vapor imagery certainly suggests the presence of a leading edge to the convective development, which leading edge is very close to the region of severe turbulence. Perhaps the two are related, but at first glance this case demonstrates the challenges inherent in predicting damaging turbulence.

(Update on 10 August: two McIDAS-V image loops, courtesy of Joleen Feltz at CIMSS, show the flight position plotted on Water Vapor (6.5 micron) imagery and window channel (10.7 micrometers) imagery derived from GOES-12 Imager data, clearly showing the flight deviation just as the plane flies over deepening new convection just to the north of Hispaniola.)

Cloud-top cooling (below) estimated using the UW/CIMSS Convective Initiation algorithm indicate cooling of 13 K in 15 minutes. Assuming a moist adiabatic atmosphere with a lapse rate of 6.5 K/km, this is vertical growth of 2 km in 15 minutes, equivalent to upward motion exceeding 200 cm per second. The flight data (the dashed line in the figure below) suggest that the airplane flew very close to this developing cumulus tower.

GOES-12 instantaneous cloud top cooling rate (with aircraft flight path)

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GOES-11 IR image with surface reports

The anomalously strong ridge of high pressure that helped to bring record warm temperatures to parts of the Pacific Northwest — which included an all-time high temperature of 103º F at Seattle WA — was also bringing unseasonably warm temperatures as far north as the Yukon Territory of Canada on 29 July – 30 July 2009. A GOES-11 IR image with surface reports (above) showed that surface temperatures were as warm as 93º F (34º C) at Carmacks (station identifier CXCK) and as warm as 82º F (28º C) at Shingle Point (station identifier CYUA) along the arctic coast.

GOES-11 visible images

These warm temperatures were helping to create an environment favorable for rapid wildfire growth. GOES-11 visible images (above) revealed a number of very large smoke plumes that developed across the Yukon Territory.

The corresponding GOES-11 3.9 µm shortwave IR images (below) showed the presence of widespread fire “hot spots”, with many pixels reaching IR brightness temperatures of 330º K or greater (red pixels) — the hottest pixels exhibited temperatures of 341º K.

GOES-11 3.9 µm shortwave IR images

A 1-km resolution NOAA-15 AVHRR Red/Green/Blue (RGB) composite image (below) offered a closer view of some of the fires and their associated smoke plumes. Note the difference in appearance between the rivers in far western Yukon Territory (along the far left side of the image) and the dark blue lakes located farther to the east. The westernmost rivers are fed by the melting glaciers (seen in the lower left corner of the image) and contain a great deal of suspended sediment, which makes their water surface appear very different than that of the lakes.

NOAA-15 AVHRR RGB false color image

===== 01 AUGUST UPDATE =====

With the aid of a favorable forward scattering angle during the early morning hours, a large plume of smoke aloft from the Yukon fires (with possible contributions from recent Alaska fires as well) could be seen on GOES-11 visible images (below), moving southeastward across parts of the Dakotas, Minnesota, Nebraska, and Iowa on 01 August 2009.

GOES-11 visible images

Later in the morning, the smoke plume was very evident on MODIS true color imagery (below) as it continued to move eastward over Wisconsin and Lake Michigan.

MODIS true color image

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First GOES-14 full-disk visible image

The GOES-14 (GOES-O) satellite was launched on 27 June 2009, and is undergoing its Post Launch Test. The first calibrated full disk visible image (above) was received by the SSEC Data Center beginning at 17:30 UTC on 27 July 2009.

A close-up view centered over central California (below) showed marine fog and stratus hugging the Pacific coast, with cumulus clouds developing inland over the higher terrain of the Sierra Nevada.

GOES-14 visible image (centered over central California)

Farther to the west, a pattern of ship tracks was evident in the marine layer stratocumulus clouds over the North Pacific Ocean (below).

GOES-14 visible image (ship tracks over the North Pacific Ocean)

A nice series of von Karman vorticies was seen streaming southward from Guadalupe Island off the west coast of Baja California (below).

GOES-14 visible image (von Karmann vorticies off Baja California)

A view centered over southern Florida (below) showed the development of numerous thunderstorms over that region.

GOES-14 visible image (centered over southern Florida)

A view centered over Lake Erie (below) showed widespread cumulus cloud development surrounding the lake (with some bands of billow clouds evident in the eastern portion of the scene). There was also a hint of a sediment plume south of Long Point, which extends into the northeastern portion of the lake from Ontario — this sediment plume could also be seen on MODIS true color imagery.

GOES-14 visible image (centered over Lake Erie)

Looking to the south of the Equator, a view centered over central Chile in South America (below) showed a small cyclonic (clockwise in the Southern Hemisphere) vortex in the marine layer clouds off the coast, with snow cover inland over the higher terrain of the Andes.

GOES-14 visible image (centered over central Chile)

Over the South Pacific Ocean, some interesting cloud structure suggesting the formation of actinae was apparent (below).

GOES-14 visible image (actinae over the South Pacific Ocean)

An image centered over the Amazon River in central Brazil (below) showed how the wide waterway was suppressing the formation of cumulus clouds (since the water surfaces were not heating up as quickly as the adjacent land surfaces). The Amazon River was still abnormally wide after record rainfall across parts of Brazil during May-June 2009 — in fact, at the mouth of the Amazon River a large sediment plume was seen fanning outward into the Atlantic Ocean on MODIS true color imagery.

GOES-14 visible image (centered over the Amazon River in Brazil)

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1-km MODIS fog/stratus product + 4-km GOES-12 fog/stratus product

A comparison of the 1-km resolution MODIS fog/stratus product with the corresponding 4-km resolution GOES-12 fog/stratus product (above) shows the importance of improved spatial resolution for the detection of areas of river valley fog (yellow to orange features) that were beginning to form across parts of southwestern Wisconsin and adjacent portions of southeastern Minnesota and northeastern Iowa at 08:15 UTC (3:15 am local time) on 23 July 2009. The features that were enhanced with the darker orange to red colors were patches of deeper stratus clouds.

About 2 hours and 45 minutes later, a similar comparison of the 1-km resolution NOAA-15 AVHRR fog/stratus product with the 4-km resolution GOES-12 fog/stratus product (below) indicated that some areas of fog had continued to increase in coverage during that time interval (especially in parts of the east-west oriented Wisconsin River valley and the north-south oriented Mississippi River valley).

1-km NOAA-15 fog/stratus product + 4-km GOES-12 fog/stratus product

An AWIPS image of the high resolution topography (below) shows which river valleys were experiencing fog formation as seen on the MODIS fog/stratus product image.

MODIS fog/stratus product + topography

After sunrise, GOES-12 visible images (below) revealed that the areas of fog burned off rather quickly as the high July sun angle promoted rapid surface heating and subsequent boundary layer mixing.

GOES-12 visible images

At 13:00 UTC (8 am local time), the GOES-12 visible image indicated that the AWIPS Fog Monitor product (below) was incorrectly identifying the fog in the Kickapoo River valley in southwestern Wisconsin (running northeast through southwest from station KVOK to KOVS) as a green “NO_FOG” feature. This underscores the importance of modifying the default values of the AWIPS Fog Monitor product so that fog features over a certain region (and during a certain season) can be more accurately characterized.

GOES-12 visible image + AWIPS Fog Monitor product

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