000 AXPZ20 KNHC 210246 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SUN JUN 21 2015 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0230 UTC. ...TROPICAL WAVES... A TROPICAL WAVE AXIS IS ALONG 92W N OF 09N TO ACROSS WESTERN GUATEMALA MOVING W AT 10-15 KT. ONLY ISOLATED MODERATE CONVECTION IS WITHIN 240 NM W OF WAVE FROM 10N-12N. A TROPICAL WAVE AXIS IS ALONG 106W/107W FROM 05N-13N MOVING W NEAR 15 KT. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM W OF THE WAVE FROM 10N-12N...AND ALSO E OF WAVE WITHIN 30 NM OF 10N104W. THIS CONVECTION REMAINS UNDER A DIFFLUENT FLOW ALOFT ALLOWING FOR CONVECTION TO PERSIST. A RECENT SCATTEROMETER PASS SHOWED VERY WELL THE WIND SHIFT ASSOCIATED THIS WAVE. THE 1742 UTC ASCAT PASS FROM SAT AFTERNOON CLEARLY DEPICTED A NE TO SE SHIFT IN DIRECTION OF MODERATE WINDS ACROSS THE WAVE AXIS. A TROPICAL WAVE AXIS IS ALONG 127W/128W FROM 05N-13N MOVING W 15 KT. SCATTERED MODERATE CONVECTION IS WITHIN 30 NM OF 07N126W. THIS CONVECTION IS FURTHER ENHANCED BY A SHARPLY NEGATIVELY- TILTED UPPER TROUGH AXIS LYING JUST TO ITS W. ANOTHER TROPICAL WAVE IS JUST W OF THE AREA ALONG 141W FROM 08N- 14N MOVING W 15 KT. NO CONVECTIVE ACTIVITY IS NOTED WITH THIS WAVE AS IT IS UNDER VERY STRONG SUBSIDENCE ALOFT. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... SCATTEROMETER DATA INDICATES THAT A WEAK MONSOON TROUGH EXTENDS W OFF THE COAST OF COLOMBIA FROM 08N79W...AND CONTINUES WESTWARD TO 08N90W TO 09N103W. THE ITCZ FORMS JUST W OF THE WAVE ALONG 106W/107W...AND EXTENDS WNW TO 10N118W...THEN TURNS SW TO JUST W OF THE WAVE ALONG 127W AND CONTINUES TO TO BEYOND 07N140W. LARGE CLUSTERS OF SCATTERED STRONG CONVECTION ARE WITHIN 120 NM OF THE TROUGH BETWEEN 82W-86W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM S OF TROUGH BETWEEN 90W-93W...WITHIN 60 NM OF LINE FROM 03N83W TO 03N88W AND S OF 04N W OF 135W. SCATTERED MODERATE CONVECTION IS FROM 02N-05N BETWEEN 124W- 127W...AND WITHIN 30 NM OF LINE FROM 127W AND 130W. ...DISCUSSION... UPPER LEVELS...THE FLOW PATTERN ASSOCIATED WITH AN ANTICYCLONE GRADUALLY LIFTING NEWD NEAR 27N126W...AND ANOTHER ONE OVER FAR NORTHERN BAJA CALIFORNIA CONTINUES TO DOMINATES THE NORTHERN PART OF THE AREA MAINLY N OF 20N W OF 110W. ANOTHER ANTICYCLONE IS FARTHER S NEAR 13N123W. AN UPPER-LEVEL-TROUGH EXTENDS ACROSS NW MEXICO AND SOUTHERN BAJA CALIFORNIA INTO THE FAR EASTERN PORTION TO NEAR 20N112W. A SHARPLY NEGATIVELY-TILTED TROUGH EXTENDS INTO THE WESTERN PART OF THE AREA FROM 19N140W SE TO 15N132W AND TO NEAR 09N128W. THIS FEATURE IS HELPING TO ENHANCE CONVECTION ASSOCIATED WITH THE TROPICAL WAVE ALONG 126W DESCRIBED ABOVE. WATER VAPOR SATELLITE IMAGERY SHOWS MODERATE TO STRONG SUBSIDENCE WITH RESULTANT DRY AIR COVERING MUCH OF THE DISCUSSION AREA N OF 15N W OF 109W. PATCHES OF BROKEN TO SCATTERED STRATOCUMLUS CLOUDS ARE SEEN FROM 17N-22N BETWEEN 110W-128W...AND N OF 16N W OF 128W. NLY FLOW IS OVER SOUTHEASTERN MEXICO...THE GULF OF TEHUANTEPEC AND THE REMAINDER OF THE AREA N OF 10N BETWEEN 91W-100W DUE TO THE COMBINATION OF AN ANTICYCLONE OVER MEXICO NEAR 21N103W...AND A BROAD UPPER LOW CENTERED OVER THE NW YUCATAN PENINSULA. BROAD RIDGING COVERS THE FAR EASTERN PART OF THE AREA E OF ABOUT 87W...WHILE AN ANTICYCLONE IS JUST S OF THE EQUATOR NEAR 89W. THE FLOW PATTERN PATTERN BETWEEN BOTH THESE FEATURES IS CREATING A DIFFLUENT FLOW PATTERN OVER THE DEEP CONVECTIVE ACTIVITY OCCURRING OVER THE EASTERN PART OF THE AREA S OF THE MONSOON TROUGH. THIS IS HELPING TO SUSTAIN THIS ACTIVITY. AT THE SURFACE...HIGH PRES OF 1020 MB NEAR 31N133W EXTENDS A RIDGE SEWD TO NEAR 20N118W. THE PRES GRADIENT BETWEEN THE RIDGE AND LOWER PRES IN THE VICINITY OF THE ITCZ IS MAINTAINING MODERATE TO LOCALLY FRESH NE-E TRADES OVER THE WESTERN WATERS N OF THE ITCZ FROM 09N-16N W OF 115W AS HIGHLIGHTED BY AN ASCAT PASS FROM THIS AFTERNOON. SEAS ARE IN THE RANGE OF 6-8 FT PRIMARILY IN MIXED NE AND SE SWELLS WITHIN THIS AREA. THE 1020 MB HIGH IS FORECAST TO REMAIN NEARLY STATIONARY OVER THE THE NEXT 24 HOURS AS A WEAK COLD FRONT APPROACHES THE FAR NW CORNER OF THE AREA. SE SWELLS MIXED WITH LONG PERIOD CROSS-EQUATORIAL SW SWELLS ARE PRODUCING AN AREA OF 8-9 FT SEAS S OF A LINE FROM 00N140W TO 04N120W TO 04N102W. THESE SEAS ARE FORECAST TO SUBSIDE SLIGHTLY OVER THE NEXT 24-48 HOURS AT A FORECAST LOCATION S OF 01S BETWEEN 105W-120W. GAP WINDS... GULF OF PAPAGAYO...PULSING WINDS OF 20-25 KT ARE EXPECTED ACROSS THIS GULF DURING THE LATE NIGHT AND EARLY MORNING HOURS WITH THE ASSISTANCE OF THE NOCTURNAL DRAINAGE FLOW AND SOME ADDED ENHANCEMENT FROM THE EASTERLY GRADIENT FLOW ACROSS THE SW CARIBBEAN. SEAS ARE FORECAST TO BUILD TO 9 FT. THE RESULTANT ENE SWELLS WILL PROPAGATE WESTWARD REACHING TO NEAR 105W SUN. THESE WINDS WILL PULSE AGAIN TO 20-25 KT LATE SUN NIGHT INTO EARLY MON MORNING. GULF OF TEHUANTEPEC...N WINDS OF 20-25 KT ARE FORECAST TO BEGIN EARLY ON MON N OF 14.5N BETWEEN 94W-96W WITH SEAS TO 8 FT AS A TROPICAL WAVE PASSES THROUGH CENTRAL AMERICA AND THE ISTHMUS OF TEHUANTEPEC. BY EARLY MON AFTERNOON...THESE WINDS ARE FORECAST TO DIMINISH TO 15-20 KT WITH SEAS TO 9 FT IN A NE SWELL WITHIN 30 NM OF A LINE FROM 16N95W TO 14N96W AS THE WAVE PULLS OFF TO THE W OF THE GULF OF TEHUANTEPEC AND VICINITY. $$ AGUIRRE