Fog in the Pecos River valley of New Mexico


GOES-R IFR Probabilities computed from GOES-13 and Rapid Refresh Data, 0700-1300 UTC, 6 February 2015 (Click to enlarge)

Fog developed over the Pecos River valley in southeastern New Mexico early on the morning of 6 February. This small-scale feature was captured well by the GOES-R IFR Probability fields, shown above. Probabilities increased quickly between 0745 and 0800 UTC. In contrast, the brightness temperature difference product, below, showed little signal until around 1000 UTC. GOES-R IFR Probability fields responded more quickly to the possible development of fog and in this case could have alerted any forecaster to its imminent formation. IFR conditions were present at Carlsbad (KCNM), Artesia (KATS) and Roswell (KROW) by 1100 UTC.


GOES-13 Brightness Temperature Difference fields, 0700 through 1300 UTC, 6 February 2015 (Click to enlarge)

MODIS data from Terra and Aqua, and VIIRS data from Suomi NPP give occasional snapshots (at high resolution) of conditions. Terra (just before 0500 UTC) and Aqua (around 0900 UTC) data were used to compute IFR Probabilities, and the high resolution data, below, is consistent with the development of fog over night. The 0900 UTC image especially suggests the possibility of fog.


MODIS IFR Probability from Terra (0448 UTC) and Aqua (0901) UTC on 6 February 2015 (Click to enlarge)

Suomi NPP data are not yet used to compute IFR Probabilities. The toggle, below, of the Day Night Band and the Brightness Temperature Difference at 0835 UTC does not show convincing evidence of fog at that time. The Day Night Band is very crisp because of the near Full Moon that provided ample lunar illumination.


Suomi NPP Day Night Band and Brightness Temperature Difference, 0835 UTC, 6 February 2015 (Click to enlarge)

The imagery above all suggest that the presence of model data — from the Rapid Refresh — enhanced the satellite data as far as suggesting IFR conditions.