000 AXPZ20 KNHC 261549 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Thu Jul 21 2016 Tropical weather discussion for the eastern Pacific Ocean from the Equator to 32N, east of 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 0600 UTC surface analysis and satellite imagery through 0945 UTC. ...SPECIAL FEATURES... Hurricane Frank is centered AT 21.2N 116.6W, or about 445 miles wsw of the southern tip of the Baja California Peninsula, at 1500 UTC, moving slowly wnw, or 290 degrees at 08 kt. The maximum sustained winds have increased to 65 kt with gusts to 80 kt. The estimated minimum central pressure has dropped to 989 mb. Currently, scattered moderate isolated strong convection is observed within 150 nm se, and within 90 nm over the nw semicircles of the center. Frank has likely peaked in strength as a minimal hurricane, and is forecast to begin a weakening trend within 24 hours. Refer to the latest NHC forecast advisory under AWIPS/WMO headers MIATCMEP2/WTPZ22 KNHC for more details. Tropical Storm Georgette is centered at 18.4N 128.6W at 1500 UTC, moving nw, or 305 degrees at 03 kt. Maximum sustained winds are currently 60 kt with gusts to 70 kt. Estimated minimum central pressure is at 987 mb. A large eye became noticeable over the past few hours, and surrounded by scattered moderate isolated strong convection within 60 nm over the se semicircle, and within 90 nm over the nw semicircle. Georgette is expected to continue to weaken as both oceanic and atmospheric conditions become less favorable and the cyclone accelerates. Refer to the latest NHC forecast advisory under AWIPS/WMO headers MIATCMEP3/WTPZ23 KNHC for more details. Also refer to the latest high seas forecast under AWIPS/WMO headers MIAHSFEP2/FZPN03 KNHC for more details on the wave forecasts associated with these systems. ...TROPICAL WAVE... A tropical wave is analyzed n of 09N along 101.5W, and has been moving w at about 12 kt. Scattered moderate isolated strong convection is noted from 10-15N within 180 nm e, and within 120 nm w of the wave axis. Expect this tropical wave to lose identity over the next day or so. ..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A monsoon trough extends wsw from the pacific coast of Colombia at 08N78W to 07N83W, then turns nw to 10N88W to 09N95W to 11N109W where scatterometer winds indicate a transition to an ITCZ. The ITCZ extends sw to 08N130W, then resumes sw of Georgette at 14N136W to 12N140W. Scattered moderate isolated strong convection is observed along the pacific coast of Colombia, Panama and Costa Rica within 30 nm either side of a line from 03N78W to 07N78W to 07N81W TO 10N86W. Similar convection is noted within 60 nm either side of a line from 05N88W to 08N94W to 09N106W, within 150 nm either side of a line from 10N113W to 08N127W, and within 60 nm of 13.5N137W. ...DISCUSSION... N of 15N e of 120W: Tropical storm force winds associated with tropical cyclone Frank will move w of 120W on on Wed, and associated seas of 8 ft or greater will shift w of 120W on Wed night. See special features above additional information on Frank. A w to e orientated surface ridge will build from 21N120W to 15N106W in the wake of tropical cyclone Frank. The weak gradient ne of the ridge will support light to gentle nw winds through the upcoming weekend, with seas of 4-6 ft. A nnw to sse orientated trough will meander e and w over the Baja California Peninsula, and the northern Gulf of California this week, supporting light and variable winds across the Gulf of California waters through Fri. A gentle to moderate southerly flow is expected to begin on Fri night, and will persist through Sat across the gulf waters. Moderate northerly flow expected late Thu night into the early daylight hours on Fri, and then again late Fri night into Sat morning with seas building to about 6 ft. Model guidance is suggesting a slightly stronger drainage flow on Sat night into Sun morning, with seas building to 8 ft. S of 15N e of 120W: See section on tropical wave. Moderate e winds are expected across, and just downstream of the Gulf of Papagayo during the overnight hours tonight and on Wed night, then guidance is hinting at fresh e drainage flow on Thu night as a surface low develops near 10N91W. The low should move westward through the upcoming weekend, with increasing chance of tropical cyclone formation later in the week. Long-period cross-equatorial sw swell, in the formed of combined seas of 6-8 ft, is forecast to propagate n across the equator between 100-115W on Thu, and reach along 08N between 90-115W on Sat before beginning to subside. Combined seas are forecast to less than 8 ft on Sun. W of 120W: See special features above for information on tropical cyclones Georgette and Frank that will pass westward through the northern portion of this discussion area through this upcoming weekend. Combined seas of 6-9 ft, primarily due to mixing swell, are expected to surround the large seas near the cyclone, and cover the waters elsewhere to the n of 12N through the upcoming weekend. $$ Nelson