Tracking the storm with Jason-2
SWH estimates derived from a Jason-2 (descending) overpass, acquired at 01:30 UTC on 17 April, are shown in Fig. 9. SWH values from a WAM analysis of the same locations are presented along with the satellite observations.
Fig.9. SWH values obtained from Jason-2 overpass at 01:30 UTC on 17 April and WAM analysis for the same period.
Fig. 9 shows that highest SWH values are obtained in a large region (approximately with 5º x 5º) centered on 53ºN, -18ºE. In this area, Jason-2 observations reveal SWH values between 7 and 8 m, and these are consistent with the WAM estimations. Lower SWH estimates (less than 3 m) were observed to the south of Ireland and over the Bay of Biscay.
Fig.10. SWH estimations obtained from Jason-2 overpass at 01:30 UTC on 18 April and WAM analysis for the same period.
Fig. 10 and Fig. 11 show SWH values obtained from Jason-2 overpasses at 01:30 UTC and 16:30 UTC on 18 April, respectively. The analysis of Fig. 10 reports a different overpass of Jason-2, with highest SWH values in a region with the same dimensions as for the previous day, but centered on 48ºN, -17ºE and with observations near 8 m.
Fig.11. SWH values acquired from Jason-2 overpass at 16:30 UTC on 18 April and WAM analysis for the same period.
Fig. 11 exhibits an ascending overpass of Jason-2 on 18 April. Satellite measurements reveal the highest wave values to be over the Bay of Biscay, mainly in the coastal zone of the north of Spain, near 45ºN, -5ºE, where SWH values reached 7 m. In contrast with the previous observations from late April 18 (see Fig. 9 and 10), it is remarkable that the highest waves had propagated to the Bay of Biscay so soon after their generation. This is evident, as Jason-2 data showed SWH around 2 m at early April 17 in the region of the Bay of Biscay.