Optimized GOES-13 Scanning becomes operational

May 6th, 2014 |

An optimization to the GOES-13 scanning schedule (discussed here) that provides, among other things, better coverage of the Caribbean Sea, became operation at 1600 UTC on May 6, 2014. Half-hourly imagery (in this case, 10.7 µm) from before the switch show intermittent coverage over the Caribbean Sea (at :15 and :45 minutes after the hour); CONUS imagery at :02 and :32, however, only extended to 14 N and to 63 W.


GOES-13 Infrared (10.7 µm) Imagery, times as indicated, before the switch to an Optimized Schedule (click to enlarge)

GOES-13 schedule optimization allows the :00 and :30 (note the slight shift in nominal time) images to scan to 5 N. (and also east to 54 W) Thus, an animation with 15-minute imagery (below) shows more complete coverage over the Caribbean.


GOES-13 Infrared (10.7 µm) Imagery, times as indicated, after the switch to an Optimized Schedule (click to enlarge)

ProbSevere results over tidewater Virginia

May 6th, 2014 |

NOAA/CIMSS ProbSevere superimposed on MRMS radar display over southeastern Virginia. Times as indicated. (Click to enlarge)


The Hazardous Weather Testbed (HWT) exercise (Click here for the HWT blog) is ongoing at the Storm Prediction Center.  One of the new products being tested by forecasters is the NOAA/CIMSS ProbSevere product. ProbSevere in the animation above highlighted a cell that produced hail. The AWIPS-2 readout suggests strong vertical growth, and strong glaciation, at 0215 UTC. (The HWT Blog entry on this storm is here) What did the satellite view?


GOES-13 Visible Imagery (0.63 µm), times as indicated. (Click to enlarge)

Visible imagery, above, from just before sunset, shows nascent convective development east of Lynchburg over southeastern Virginia, and also older convection over the Chesapeake Bay and Delmarva Peninsula. The infrared imagery (10.7 µm), below, shows rapid development of convection over southeastern Virginia after 0000 UTC. The first convective cell, which cell is east of the Outer Banks of North Carolina at 0315 UTC, had cloud-tops that cooled about 12 C in 17 minutes (between 0115 and 0132 UTC); the storm that produced hail, and was warned, had cloud-tops that cooled 20 C in 13 minutes, between 0202 UTC and 0215 UTC. This strong vertical growth contributes to a big increase in the ProbSevere value.


GOES-13 Infrared Imagery (10.7 µm), times as indicated. (Click to enlarge)

When interpreting the radar and satellite imagery, be aware of the effects of parallax on the satellite imagery. GOES-13 imagery displayed here is not corrected for parallax. GOES-13 data are parallax-corrected when used in ProbSevere computations, of course.