CIMSS Satellite Blog

AWIPS images of geostationary satellite water vapor channel data

AWIPS images of geostationary satellite water vapor channel data (above) showed a long moisture plume moving across the Pacific Ocean toward the west coast of the US on 02-03 October 2008. A comparison of GOES-11 water vapor channel data with POES (AMSU) and SSM/I Total Precipitable Water (TPW) products (below) revealed that TPW values were as high as 50-60 mm (2.0-2.4 inches) within this moisture plume. The MIMIC TPW product suggested that this moisture plume originated over the western Pacific Ocean, southeast of Japan.

AWIPS images of POES TPW products and GOES water vapor channel

This moisture plume was associated with a strong polar jet stream, as seen by an overlay of hourly MADIS atmospheric motion vectors on GOES water vapor channel imagery (below).

GOES water vapor images + MADIS winds

The 18 UTC GFS model fields were forecasting maximum winds in the core of the jet to reach 170 knots (below) — there were a few MADIS wind vectors with speeds of 177-181 knots around that time (and a MADIS wind vector with a speed of 191 knots was seen at 21 UTC).

GFS winds + MADIS winds

AWIPS satellite images + surface analysis

A cold frontal boundary was moving southward across the Pacific Ocean and approaching the Hawaiian Islands on 29 September - 30 September 2008, as seen on a comparison of AWIPS visible, IR, and water vapor satellite imagery and corresponding surface analysis (above). According to the boundary layer Meteorological Assimilation Data Ingest System (MADIS) atmospheric motion vectors (below), the front was moving southward at a speed of around 15-20 knots — IR cloud top temperatures were warmer than 0º C along the frontal cloud band north of Hawaii, suggesting rather shallow cloud features.

AWIPS image of GOES-11 10.7 µm IR channel and MADIS winds

A closer view using GOES-11 visible imagery (below) revealed that a series of mesoscale vorticies had developed along the frontal boundary. Another interesting feature was the persistent volcanic plume downwind of the big island of Hawaii (streaming toward the southwest), due to ongoing activity at the Kilauea volcano since Spring 2008 (see the April 2008 CIMSS satellite blog entry). Also note the long, thin line of cumulus clouds below the volcanic plume, a result of lee-side convergence.

GOES-11 visible images

A comparison of GOES-11 and GOES-13 visible images (below) shows that the volcanic plume was even more apparent with the larger viewing angle and more favorable “forward scattering” geometry from the GOES-13 satellite (positioned at 105º W longitude, vs. 135º W longitude for GOES-11).

GOES-11 and GOES-13 visible images