The following tropical advisory is pulled from the National Hurricane Center. New advisories are released approximately every 3 hours.
Axpz20 Knhc 202202 Twdep tropical weather discussion NWS TPC/National Hurricane Center miami fl 2205 UTC fri nov 20 2009 tropical weather discussion for the eastern pacific ocean from the equator to 32N, east of 140W. based on 1800 UTC surface analysis and satellite imagery through 2115 UTC. ...itcz, the itcz axis extends from 07N77W to 04N80W to 06N91W to 05N106W to 08N119W to 06.5N140W. scattered moderate to isolated strong convection within 150 nm s of axis e of 81W, and within 240 nm n of axis and 90 nm s of axis w of 116W. ...discussion... w of 115W, a deep layer trough extending from along the coasts of washington-oregon-n cal to 23N127W was digging e-se on the east side of rex block centered on the large ridge n of hawaii. an associated cold front extends from nrn california to 30N133W to 28N40W and continues wwd as a shear axis. the front was shifting ese and towards central california and ne portions of the forecast area. a 1020 mb high near 27N132W was collapsing, with the stronger central pacific ridge, centered on a 1027 mb surface high along 33N and n of hawaii, was sliding and building ewd behind the cold front. recent scatterometer passes show moderate to fresh 20-25 kt trade winds s of the high pres from generally 20-22N to the nrn fringes of the itcz along 07.5N from 114W wwd behind 140W. the resultant wind waves were mixing with a fading pulse of nw swell to produce seas of 8 to 11 ft n of 10N and w of 115W, with seas up 12 to 14 ft from 17N138W and downwind, in the strongest ne trade wind flow. farther e, the trade wind flow has diminished slightly from yesterday as the high to the north continues to weaken. these fresh trades will expand and spread farther e during the next 24 hours as the central pacific high continues to build e behind the front n of the area. the front itself is expected to become diffuse by sat night across ne portions of the area as the associated upper dynamics lift out. meanwhile divergent flow aloft on the right rear entrance area of a weak jet max on the se side of the upper trough is interacting with the modest trade wind convergence to enhance scattered convection n of the itcz w of 120W. looking ahead the weekend, the blocking ridge n of hawaii will break down ahead of an approaching central pacific trough. this will allow the surface ridge that has begun to build behind the current weakening w coast cold front to remain in place n of the area, maintaining a broad swath of fresh to strong trades from 10N to 25N w of 120W. se cross-equatorial flow will converge with the ne trades to keep clusters of convection active along the itcz w of 120W as well. meanwhile another pulse of nw swell yielding combined seas of 10 ft and greater will dominate most of the marine area w of 115W tonight and sat. e of 115W, the main weather phenomena remains the persistent central america gap winds. high resolution scatterometer data showed nely winds of 20 to 25 kt through the gulf of papagayo, again this morning, enhanced by drainage effects, with 20 kt winds noted off of the gulf of fonseca. fresh trade winds are pushing from the sw caribbean s across panama as well, into the gulf of panama near 20 kt, enhancing moderate to strong nocturnal convection off the colombian coast. meanwhile, scatterometer data also showed nly flow of 20-25 kt persisting to flow s out through the gulf of tehuantepec, but is forecast to diminish briefly through late saturday before post frontal winds across the w gulf of mexico flow drain through the pass again sunday.