September 29th, 2014
GOES-13 0.63 µm visible channel images with METAR surface reports (click to play animation)
Tropical Invest 97L formed near Bermuda during the pre-dawn hours on 29 September 2014. After sunrise, AWIPS II images of GOES-13 0.63 µm visible channel data (above; click image to play animation) revealed a well-defined low-level circulation spinning just to the west of Bermuda. It is interesting to note that at 12:55 UTC a waterspout was reported 4 km to the east of the Bermuda International Airport (station identifier TXKF), associated with a band of deep convection that was moving northward (below).
GOES-13 0.63 µm visible channel image with Bermuda METAR observation
An overpass of a Metop satellite at 14:38 UTC provided a good view of the surface wind field with data from the ASCAT scatterometer instrument (below). There was one wind vector with a speed around 30 knots (green) just to the east of the center of circulation.
GOES-13 0.63 µm visible channel image with Metop ASCAT scatterometer surface winds
A comparison of Terra MODIS 0.65 µm visible channel and 11.0 µm IR channel images at 15:25 UTC (below) showed that the coldest cloud-top IR brightness temperatures of -55º C (orange color enhancement) were located to the north of the circulation center.
Terra MODIS 0.65 µm visible channel and 11.0 µm IR channel images
September 15th, 2014
Advanced Dvorak Technique (ADT) plot for Hurricane Odile
A time series plot of the Advanced Dvorak Technique (ADT) intensity estimate for Hurricane Odile (above) showed that the tropical cyclone went through a period of rapid intensification on 14 September 2014, reaching Category 4 on the Saffir-Simpson hurricane scale as it moved northwestward toward the southern tip of Baja California (Odile track map).
McIDAS images of GOES-15 10.7 µm IR channel data covering the 13-15 September period (below; click image to play animated GIF; also available as an MP4 movie file) showed Odile from the period of rapid intensification on the 14th to landfall on the 15th. Odile made landfall near Cabo San Lucas around 04:45 UTC on 15 September, with an estimated intensity of 110 knots — this ties with Hurricane Olivia (1967) as the strongest hurricane to make landfall in Baja California Sur during the modern satellite era.
GOES-15 10.7 µm IR channel images (click to play animated GIF)
Several hours prior to landfall, a comparison of GOES-15 10.7 µm IR and DMSP SSMIS 85 GHz microwave images from the CIMSS Tropical Cyclones site (below) indicated that Odile had a large outer eyewall at that particular point in time.
GOES-14 10.7 µm IR channel image and DMSP SSMIS 85 GHz microwave image
Even after several hours of traversing the rugged terrain of the Baja California peninsula, Odile continued to maintain hurricane intensity; the faint signature of an eye could still be seen on AWIPS II images of Suomi NPP VIIRS 0.64 µm visible channel and 11.45 µm IR channel data at 22:34 UTC on 15 September (below).
Suomi NPP VIIRS 0.64 µm visible channel and 11.45 µm IR channel images
September 8th, 2014
GOES-15 10.7 µm IR channel images (click to play animation)
McIDAS images of 4-km resolution GOES-15 10.7 µm IR channel data (above; click image to play animation; also available as an MP4 movie file) showed the merger of two large mesoscale convective systems (MCS) which produced an all-time record maximum calendar day precipitation amount of 3.29 inches at Phoenix Sky Harbor Airport (PHX) on 08 September 2014. Some locations in the Phoenix area received in excess of 5 inches of rainfall (NWS Phoenix event summary).
An AWIPS-II image of 375-meter resolution Suomi NPP VIIRS 11.45 µm IR channel data (below) showed the MCS pair at 09:07 UTC or 3:07 AM local time — this was prior to the merger, and the southeastern storm exhibited a minimum cloud-top IR brightness temperature of -84º C (purple color enhancement), which was much colder than the -71º C seen with the northwestern storm. At the onset of the heavy thunderstorms at PHX, southerly to southeasterly winds — likely outflow from the southeastern MCS — gusted as high as 31 knots (36 mph) and visibility was reduced to 0.8 mile (surface reports: text | graph).
Suomi NPP VIIRS 11.45 µm IR channel image
As the circulation of former-Hurricane Norbert continued to spin over the Pacific Ocean west of Baja California, deep tropical moisture kept working its way farther inland — GOES sounder Total Precipitable Water (TPW) values in excess of 50-60 mm (2.0 to 2.4 inches) were eventually seen across the southwestern half of Arizona (below; click image to play animation).
GOES sounder Total Precipitable Water derived product images (click to play animation)
The Blended Total Precipitable Water product (below; click image to play animation) also showed values of 50-60 mm working their way into southwestern Arizona during the 06-08 September period.
Blended Total Precipitable Water product (click to play animation)
The Percent of Normal TPW product (below; click image to play animation) indicated that these TPW values were in excess of 200% of normal (yellow color enhancement) over large portions of the Desert Southwest. On the morning of 08 September, the TPW value of 2.03 inches derived from rawinsonde data at Tucson, Arizona set a record high for the month of September at that location.
Percent of Normal TPW product (click to play animation)
September 2nd, 2014
NASA Global Hawk flight path, with Cloud Height, Tropical Overshooting Tops, and Lightning data (click to play animation)
The NASA Global Hawk aircraft are once again being used to study tropical cyclones during the 2014 season. As part of CIMSS participation in GOES-R Proving Ground activities, a Global Hawk flight path tool was developed to display important parameters such as ACHA Cloud Top Height, Tropical Overshooting Tops, and lightning (above; click image to play animation). Global Hawk pilots use this product to navigate the aircraft around locations of potential turbulence.
GOES-13 0.63 µm visible channel images (click to play animation)
To support the Global Hawk investigation of Tropical Storm Dolly on 02 September 2014, the GOES-13 satellite was placed into Rapid Scan Operations (RSO) mode to provide images at 5-7 minute intervals. GOES-13 0.63 µm visible channel images (above; click to play animation) and 10.7 µm IR channel images (below; click to play animation) are shown which cover the 3-hour period of the Global Hawk flight segment shown above. There is evidence of overshooting tops seen in the visible imagery, with cloud-top IR brightness temperatures of -80º C and colder (purple color enhancement).
GOES-13 10.7 µm IR channel images (click to play animation)