Wednesday, July 13, 2005

N42RF is having 50-hr maintenance today, and N43RF arrived to Costa Rica at about 00 UTC after having a difficult time landing because of bad weather at the airport. The ER-2 is not flying today.

The forecast situation shows that Emily has continued to intensify slowly and is still generally tracking just north of due west. The NHC forecast calls for Emily to be in the western Caribbean by Sunday and threatening the Yucatan by Monday. In the East Pacific, conditions remain generally similar to what they were the previous day. A north- south oriented squall line moved offshore of Costa Rica and may have been associated with a tropical wave, although there was some disagreement as to whether or not a wave was actually there. What was clear, however, was southwesterly flow in the low-levels and at the surface. The western boundary of that flow, delineating a cyclonic shear zone, is oriented roughly SW-NE and centered at about 94-96 W. The upper-level winds show moderate northeasterly shear, associated with the southern edge of a strong upper-level anticyclone situated over the Gulf of Mexico. Some of the global models have predicted that this upper-level anticyclone will move toward the southwest and become centered over Mexico, indicating a possible decrease in the vertical shear over the region of interest. Thus, conditions may be becoming more favorable for genesis. For this reason the plan called for N42RF to conduct a survey mission on Thursday, takeoff at 17 UTC from San Jose. N43RF would then conduct a follow-on mission on Thursday night, takeoff at 05 UTC Friday. The ER-2 would fly a coordinated mission with N43RF, takeoff at 06 UTC Friday. A go-no go decision was planned for 13 UTC for N42RF and 18 UTC for N43RF. Depending on what happens on Thursday, and what is found on these two missions, follow-on missions may be schedule for Friday. As for the models, NOGAPS is suggesting that a depression may form anywhere from 2-5 days into the future and possibly be in range of operations from San Jose.

Rob Rogers
HRD Field Program director