000 AXPZ20 KNHC 121004 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Tue Mar 12 2019 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 0845 UTC. ...SPECIAL FEATURES... Gale Warning: Low pressure of 1005 mb within about 60 nm to the west of Punta Baja in Baja California Norte will track in an east-northeast direction direction cross the northern part of Baja California and the northern Gulf of California this morning. Minimal gale force winds and seas of 12 to 15 ft are occurring within 60 nm of the low in the southwest semicircle will diminish to strong winds in just a few hours. Please read the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03 KNHC/HSFEP2 or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough extends from 08N84W to 05N88W. The ITCZ extends from 05N88W to 04N108W to 04N130W and to beyond 04N140W. Scattered moderate convection is seen within 120 nm north of the ITCZ between 110W and 114W, within 60 nm south of the ITCZ between 127W and 129W, and within 30 nm of the ITCZ between 91W and 95W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A not so typical lower latitude occurrence of a mid-latitude low pressure system with attendant fronts has reached a location of near 30N117W, which is about 60 nm west of Baja California Norte. Short-lived gale force winds near the low in its southwest semicircle will soon diminish. See Special Features section for more details on this system. As this low moves across northern Baja California this morning, its associated cold front that is along a position from near 28N113W to near 21N115W will begin to gradually weaken and at the same time the occluded front from 28N113W to the low also weakens. Once the gale force winds diminish, strong winds are expected within 180 nm of the low in its SW semicircle as it soon approaches 30N116W, and mainly fresh winds ahead of the low. Fresh to locally strong northerly winds are expected over the waters between Las Marias Islands and Los Cabos following passage of the cold front this afternoon and evening. A set of large long- period northwest swell will propagate across the forecast waters in the wake of the front. This set of swell will begin to reach the Revillagigedo Islands tonight and through the rest of the week bringing with it potentially hazardous surf conditions along the coast of Baja California. Looking ahead, high pressure building over the Great Basin will support strong northwest winds across the Gulf of California by late Thu. Farther south, a cold front moving through the western Gulf of Mexico will result in near gale-force gap winds through the Gulf of Tehuantepec by late Fri. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Ship with call sign "PCHM" reported 30 kt a few hours ago as it approached the border between Nicaragua and Costa Rica. This location is in the far east side of the strong to near gale force northeast winds from the ongoing Gulf of Papagayo gap wind plume. A fairly tight pressure gradient over Central America and the Caribbean Sea will continue to support fresh to near-gale force northeast winds pulsing through the Gulf of Papagayo through Wed night. Winds will be strongest during the overnight and early morning hours with the assistance of nocturnal drainage flow. Expect seas to peak at 10 or 11 ft ft downstream associated with the gap wind plume mainly through the next 24 hours. These winds are forecast to diminish on Fri. Fresh to strong north to northeast gap winds over the Gulf of Panama will pulse again tonight, then diminish to moderate to fresh winds pulsing at night over this area through Fri. Elsewhere, gentle to moderate winds with mixed swell will persist through Fri. REMAINDER OF THE AREA... Strong high pressure ridging is building east-southeast across the waters in the wake of the previously described low and cold front. Partial Ascat data from the overnight hours revealed a large area of fresh to strong north to northeast winds over the waters roughly north of 13N and west of 130W. Latest altimeter data showed seas to 14 ft over the outer waters north of 19N east of 130W and to 12 ft north of 19N west of 130W. west of 135W. The gradient between strong high pressure that is building southeastward over the northern waters and the cold front associated with the Special Features low is resulting in fresh to strong northwest winds over waters north of 25N and east of 125W along with seas of 11 to 14 ft in northwest swell. This area of winds and large seas will shrink through tonight, and is forecast to be confined to north of 29N and east of 124W by late tonight. Further south, the building ridge will support an expanding area of fresh to strong trade winds from about 05N to 20N today, then from about 08N to 14N and west of 125W tonight through early Thu. Wed. Seas in this region will build to around 12 ft with a mix of longer period northwest swell and shorter period northeast wind waves. The large northwest swell will gradually decay as it moves through the region, but seas of 8 to 10 ft will dominate the waters west of 110W through Fri. $$ Aguirre