January 22nd, 2015
Suomi NPP VIIRS 11.45 um IR channel image, with METAR surface reports
With a cloud-free sky and light winds under a dome of high pressure, strong radiational cooling over a deep snowpack allowed the overnight low temperature to drop to -47º F (-43.9º C) at Wabush Lake (station identifier CYWK) in far western Labrador — this was quite possibly the coldest site in North America on 22 January 2015 (the coldest overnight low temperature in Alaska that morning was -39º F or -39.4º C at Galena). AWIPS images of Suomi NPP VIIRS 11.45 µm IR channel data (above) and MODIS 11.0 µm IR channel data (below) showed minimum surface IR brightness temperatures of -47º C or -52.6º F (darker blue color enhancement) in the western Labrador.
MODIS 11.0 um IR channel image, with METAR surface reports
A comparison of 1-km resolution Soumi NPP VIIRS 11.45 µm and 4-km resolution GOES-13 10.7 µm IR images (below) showed the advantage of higher spatial resolution for more accurately locating the coldest regions.
Suomi NPP VIIRS 11.45 um and GOES-13 10.7 um IR channel images
January 22nd, 2015
FY-2G Color Composite Image from 0500 UTC 8 January 2015 (Click to enlarge)
The Chinese Meteorological Satellite FY-2G was launched on 31 December 2014 from Xichang Launch Center in Sichuan Province. It has achieved Geostationary Orbit at 99.5º E and its first full disk Color Composite image, above, from 8 January 2015, has been released.
For more information on FY-2G, click here. FY-2G is the eventual replacement for FY-2E at 105º E.
January 21st, 2015
Suomi NPP VIIRS Sea Surface Temperature (SST) product
A sequence of four AWIPS images of the Suomi NPP VIIRS Sea Surface Temperature (SST) product (above) showed very detailed information about the SST patterns in the Gulf of Mexico on 21 January 2015. Two features in particular are worth noting: (1) what appears to be a train of Kelvin-Helmholtz instability waves along one of the northern boundaries of the Loop Current (best seen on the 06:52 UTC image), and (2) a small-scale cyclonic eddy located between the far northern edge of the Loop Current and the Mississippi River Delta. On the final 19:57 UTC image, SST values in the general region of this small-scale eddy ranged from 46.7º F at the Mississippi River Delta (cyan color enhancement) to 79.7º F (darker red color enhancement) near the northern edge of the Loop Current – a difference of 33º F within a distance of only about 100 miles.
January 20th, 2015
MIMIC Total Precipitable Water product, with Tropical Surface Analyses (click to play animation)
AWIPS images of the MIMIC Total Precipitable Water product (above; click image to play animation) showed a broad moist plume in the equatorial South Pacific Ocean, within which Tropical Storm Niko began to develop during the 19 January – 20 January 2015 period. By the end of the animation, Gale Force winds were being analyzed within the eastern semicircle of the developing cyclone. Metop ASCAT surface scatterometer winds at 08:01 UTC (below) showed winds as strong as 42 knots (though the direction of the stronger yellow wind barbs was suspect, likely due to rain contamination).
MIMIC TPW product, with Metop ASCAT surface scatterometer winds
After daybreak on 20 January, McIDAS images of GOES-15 (GOES-West) 0.63 µm visible channel data (below; click image to play animation) showed the development of spiral banding wrapping into the central low-level circulation center as the system reached tropical storm intensity by 18 UTC. In addition, a few strong convective pulses with distinct overshooting tops could be seen near the core of Niko.
GOES-15 0.63 µm visible channel images (click to play animation)
An animation of GOES-15 10.7 µm IR channel images from the CIMSS Tropical Cyclones site (below) included an overlay of contours of the deep layer (200 – 850 hPa) wind shear at 18 UTC — Tropical Storm Niko developed in a region characterized by low wind shear, which enabled the storm to rapidly intensify.
GOES-15 10.7 µm IR channel images, with contours of deep layer wind shear