B razilian N ortheast J et S tream: frequency, wind speed and direction

The Brazilian N ortheast J et S tream ( BNEJS ) was analysed over 16 years (1994–2009) using reanalysis data from the N ational C enter for E nvironmental P rediction –  N ational C enter for A tmospheric R esearch (NCEP‐NCAR). With a wind speed higher than 30 m s −1 , the BNEJS was observed on average for 69 days year −1 , and reached 114 days in 2003. More frequently, these jet streams were observed during the rainy season (9 days month −1 , on average), and rarely between F ebruary and A pril (2 days month −1 , on average). The study found that the BNEJS , with a minimum speed limit of 20 m s −1 , occurred very often (it was detected almost every day). The average wind speed of the BNEJS was 37 m s −1 , and reached a maximum of 64 m s −1 . The directions of the BNEJS were identified to be more often from the northwest and the southwest, and were rarely found occurring from the north. That from the northwest occurred more frequently in winter and autumn (288 and 172 days, respectively). The BNEJS 's direction from the southeast has a similar frequency during both spring and summer (64 and 63 days, respectively).