Hurricane Noel QuikSCAT winds

November 2nd, 2007 |

AWIPS GOES-12 IR image + QuikSCAT winds

Hurricane Noel remained a minimal Category 1 hurricane early in the day on 02 November 2007, although the satellite presentation was starting to deteriorate (GOES-12 IR animation) as the storm began the transition to an extratropical system. SeaWinds scatterometer data from the QuikSCAT satellite around 10:48 UTC (above, and below) did show two wind retrievals of 74 knots just to the northwest of the storm center. However, those two 74 knot wind speed points had the “Rain Flag” active (all the wind barbs with circles on the CIMSS Tropical Cyclones TCTrak display have the Rain Flag active), meaning that the presence of rainfall may have contaminated the data at those points — energy backscattered from large rain drops can constitute a significant (but unknown) portion of the measured echo energy.

AWIPS GOES-12 IR + QuikSCAT winds

Noel becomes a Hurricane

November 1st, 2007 |

AWIPS GOES-12 IR images (Animated GIF)

Tropical Storm Noel intensified late in the day on 01 November 2007 to become a minimal Category 1 hurricane just north of the Bahamas. AWIPS images of the GOES-12 10.7µm IR channel (above) show that the circular area of very cold cloud top temperatures (colder than -80º C, green enhancement) became more well-defined and moved closer to the surface circulation during the intensification process.

Tropical Storm Noel – Convective bursts

November 1st, 2007 |

GOES-12 10.7µm IR images (Animated GIF)

After spending some time meandering over Cuba and just off the northern coast of the island, Tropical Storm Noel began to intensify a bit and produce bursts of convection within its eastern semicircle as it started to move slowly northward during the day on 31 October 2007. AWIPS images of the GOES-12 10.7 µm IR channel (above) revealed a significant increase in the areal coverage of very cold cloud top temperatures (below -80ºC, light green enhancement); in fact, isolated IR brightness temperatures as cold as -92º C (white pixels) were noted at 04:01 UTC on 01 November.