526 AXPZ20 KNHC 242311 CCA TWDEP Tropical Weather Discussion...Corrected NWS National Hurricane Center Miami FL 2205 UTC Tue Jul 24 2018 Corrected ITCZ/MONSOON TROUGH section 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 1800 UTC surface analysis and satellite imagery through 2145 UTC. ...TROPICAL WAVES... A tropical wave has an axis along 94W from 03N to 04N, moving westward near 22 kt. After appearing better defined in satellite imagery this morning, the wave is presently appearing weaker in both visible and IR imagery. Some subtle evidence of the wave is noted in the latest model 700 mb streamline analysis. Only scattered moderate convection is within 30 nm of line from 12N93W to 13N91W. A tropical wave has an axis extending from 04N105W to weak low pressure near 10N105W 1012 MB to 16N105W, moving westward at 15 kt. Model 700 mb streamline analysis depicts this wave as having a broad cloud pattern along with a sharp northeast to southeast wind shift. Satellite imagery also concurs that the cloud pattern is rather broad. Deep convective activity associated with the wave has remained constant throughout the day, and the associated moisture is strongly observed in the TPW moisture animation. The convection consists of the scattered moderate isolated strong type intensity within 45 nm of a line from 12N109W to 12N106W to 13N105W. Scattered moderate convection is within 30 nm of 14N104W and within 30 nm of 10N108W. Models keep the signal of the low pressure tied to the wave over the next couple of days as the models track the system track in a general west to west-northwest motion. A tropical wave has an axis extending from 04N134W to low pressure near 12N133W 1010 mb to 17N134W. It is moving westward at an estimated speed over the past 24 hours of about 23 kt. The wave is associated with troughing at 700 mb as depicted in model guidance, and shows a strong signal in the TPW moisture animation. The low embedded along this wave remains rather compact as has been over the past 2-3 days and as is currently observed in satellite imagery. An Ascat pass from 1714Z this afternoon captured fresh northeast to east winds within 240 nm of the low in the N quadrant. The wave and low is forecast to move cross 140W on Wed morning. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...Corrected The monsoon trough axis extends from a 1011 mb low over NW Colombia near 10N74W to 08N87W to 10N100W to low pressure near 10N105W 1012 MB and 10N118W, where latest scatterometer data indicates the ITCZ begins and continues to low pressure near 12N124W 1010 mb to low pressure near 12N134W 1010 mb and to 09N140W. Aside from convection associated with the tropical waves and associated lows, scattered moderate isolated strong convection is within 240 nm south of the axis between 78W-81W. Scattered moderate convection is within 180 nm south of the axis west of 137W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weak high pressure ridge extends east-southeastward from well northwest of the 250 nm boundary east-southeastward to 25N118W and to near the Revillagigedo Islands. The pressure difference between the ridge and troughing over Baja California and the southwestern United States is maintaining light to moderate northwest winds across the Mexican offshore waters. Little change is expected in these conditions during the next several days. A long period SW cross-equatorial swell is affecting all of the offshore waters. his extensive swell event is peaking, and is inducing seas ranging between 7-9 ft over the open waters for all the forecast zones. Seas will slowly subside through the remainder of the week. Scattered showers and thunderstorms are moving northwestward over much of the central section of the Baja California Peninsula. This activity is weakening as it approaches the northern section of the peninsula. Additional activity may form during the overnight hours as an upper-level disturbance rides to the north and northwest on the southwestern periphery of an upper-level anticyclone that is centered over southwestern New Mexico. It is possible that activity repeats late on Wed and Thu as well as the high drifts to the SW. Gulf of Tehuantepec: South to southwest winds will shift to northwest winds Wed afternoon and become moderate southwest winds Wed night and gentle to moderate west to northwest winds during Thu. Waveheights of up to 8 ft in the gulf region will slowly subside through the end of this week as swell energy from the past several days dissipates. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Northeast to east winds will pulse to fresh speeds during the late night and morning hours for the remainder of this week. Seas from these winds are interacting with the SW swell event resulting in mixed seas in the gulf between of 8 and 9 ft. Seas in this area will subside below 8 ft on Wed. Gentle to moderate northeast to east winds are forecast elsewhere north of the monsoon trough which will meander west of Central America between 07N and 10N. Moderate to fresh south to southwest winds are generally expected to the south of the trough axis during the next several days. A long-period SW cross-equatorial swell event encompasses just about the entire region. Maximum combined seas are near 9 ft over these waters. Wave model guidance suggests that these seas will gradually subside to around 8 ft Wed, and then to less than 8 ft Thu. REMAINDER OF THE AREA... A high pressure ridge extends south-southwest from a strong and nearly stationary 1030 mb high centered well north of the area at 42N140W through to 32N145W, and southeastward from there to 27N135W and weakens as it reaches 25N128W to 22N121W and to near the Revillagigedo Islands. The pressure gradient between the ridge and lower pressure found along and near the monsoon trough is maintaining moderate to fresh NE trade winds north of the monsoon trough, south of 20N and west of 115W. Little change in this pattern is expected for the upcoming week. Low pressure of 1010 mb is located near 12N along the tropical wave that extends from 04N134W to 17N134W. The gradient between the low and high pressure ridging to its north is resulting in fresh to strong northeast to east winds within 180 nm to its north along with seas in the 8-10 ft range. The low is forecast by the global models to move west of the area early Wed. Fresh to strong northeast to east winds will linger in its wake from 14N to 17N west of 139W, with seas of 8-10 ft. These conditions will diminish by Wed evening as the low moves farther away from the discussion area. Another low pressure center of 1010 mb is currently centered near 12N124W. Scattered moderate convection is noted within 90 nm of the low, except 60 nm in the SE quadrant. This low will weaken as it tracks in a west-southwest motion to near 10N130W by early Wed afternoon and to near 11N135W by Thu afternoon and move west of 140W Fri. Fresh to strong northeast to east winds and seas of 8-9 ft can be expected within 90 nm of the low in the N quadrant through tonight. These winds will diminish to mainly fresh winds on Wed, with seas of 8-9 ft within 240 in the N quadrant on Wed before decreasing in coverage on Thu. Large long-period SW swell continues crossing the equator, with seas of 8-9 ft over the waters east and southeast of a line from 30N123W to 20N128W to 19N140W to 12N140W to 10N117W to 04N111W to 03.4S120W, except the lee of the Galapagos Islands. Wave model guidance indicates that these seas will subside to less than 8 ft, except for a small pocket of 8 ft seas in southwest swell from 02N-05N between 81W and 85W. $$ Aguirre