Daily Archives: July 19, 2016

Comparing GOES-R IFR Probability Fields and Webcam Observations over Alaska


GOES-R IFR Probability, 1345 UTC on 19 July 2016, and 1400 UTC Observations of surface Visibility. Blue arrows point to, from left to right, Wainwright, Barrow, and Deadhorse Alaska (Click to enlarge)

The FAA website that includes webcams over much of Alaska provides a great opportunity to match IFR Probability fields with surface observations. In the image above, Wainwright AK shows a 3-mile visibility, but Barrow and Deadhorse farther east report 10-mile visibilities. All three stations are very near high IFR Probabilities — the red/orange region has IFR Probabilities exceeding 90%. What to the webcams at the three stations show? Screen captures from the three webcams are below. Webcams from both Barrow and Deadhorse show non-IFR conditions. Wainwright shows a dense fog through which the sun is dimly visible. These webcam observations are in general agreement with the GOES-based IFR Probability fields: only Wainwright is in a region where IFR Probabilities are consistently high.


Wainwright AK webcams at 1413 UTC on 19 July 2016 (Click to enlarge)


Barrow AK webcams at 1413 UTC on 19 July 2016 (Click to enlarge)


Deadhorse AK webcams at 1413 UTC on 19 July 2016 (Click to enlarge)



GOES-R IFR Probabilities, 1645 UTC on 19 July 2016, and 1700 UTC Observations of Ceilings/Visibilities (Click to enlarge)

The image above is of GOES-R IFR Probabilities over the Aleutians, along with surface observations of ceilings and visibilities.  In general, IFR Probabilities are a bit higher on the northern side of the Aleutians (False Pass, Cold Bay, Nelson Lagoon, Port Heiden, Pilot Point) than the southern side (Perryville, King Cove).  That is confirmed with the screen captures of webcam imagery, seen below.  The webcam scenes are aligned from west to east, starting at False Pass AK and ending at Pilot Point.


Webcam imagery from False Pass AK (PAKF) at 1653 UTC, 19 July 2016 (Click to enlarge)


Webcam imagery from Cold Bay, AK (PACD) at 1654 UTC on 19 July 2016 (Click to enlarge)


Webcam imagery from King Cove, AK, (PAVC) at 1655 UTC on 19 July 2016 (Click to enlarge)


Webcam imagery from Nelson Lagoon, (PAOU) 1656 UTC on 19 July 2016 (Click to enlarge)


Webcam Imagery from Perryville, AK, 1659 UTC on 19 July 2016 (Click to enlarge)


Webcam imagery from Port Heiden, AK, (PAPH) 1657 UTC on 19 July 2016 (Click to enlarge)


Webcam Imagery from Pilot Point, AK, (PAPN) at 1658 UTC on 19 July 2016 (Click to enlarge)