000 AXPZ20 KNHC 271008 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC MON JUL 27 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0900 UTC. ...SPECIAL FEATURE... A COMPLEX TROPICAL WAVE WAS IDENTIFIED INVOF 124W-134W FROM 04N TO 17N...WITH A TRAILING LOW TO MIDDLE LEVEL PERTURBATION PRODUCING A SURFACE TROUGH FROM 13N124W TO 17N122W. THE WAVE WAS GENERALLY MOVING WWD NEAR 15 KT. RECENT 05-0600 UTC ASCAT PASSES CONTINUE TO INDICATE 20-30 KT E TO SE WINDS OCCURRING ACROSS THE NE PORTIONS OF THE TRAILING SURFACE TROUGH...WERE SEAS ARE 8-10 FT. HOWEVER...A SURFACE LOW ANALYZED EARLIER TONIGHT WITH THIS FEATURE IS NOT CURRENTLY EVIDENT IN THE ASCAT PASSES. CONVECTION HAS DIMINISHED IN ASSOCIATION WITH THE SURFACE TROUGH WHILE INCREASING ALONG THE LEADING EDGE OF THE TROPICAL WAVE. SCATTERED MODERATE TO STRONG FROM 03N TO 09N BETWEEN 132W AND 138W. ELSEWHERE WIDELY SCATTERED MODERATE TO STRONG FROM 09N TO 16N BETWEEN 121W AND 141W. ALTHOUGH UPPER LEVEL NW WIND IS CURRENTLY PRODUCING MODERATE TO STRONG WIND SHEAR ACROSS THE N PORTIONS OF THIS FEATURE...ENVIRONMENTAL CONDITIONS ARE SOMEWHAT CONDUCIVE FOR DEVELOPMENT OVER THE NEXT FEW DAYS. A TROPICAL DEPRESSION COULD FORM DURING THE NEXT FEW DAYS AS THIS FEATURE MOVES W TO W-NW AROUND 15 KT. ...TROPICAL WAVES... A TROPICAL WAVE WAS INVOF 101W-103W FROM 06N-17N...MOVING W AROUND 15-20 KT. ISOLATED TO LOCALLY SCATTERED MODERATE TO STRONG CONVECTION WAS OCCURRING ABOUT THIS WAVE...MAINLY WITHIN 240 NM EITHER SIDE OF THE MONSOON TROUGH. A TROPICAL WAVE WAS INVOF 15N113W TO 1009 MB LOW PRES NEAR 07N110W...MOVING W AROUND 15-20 KT. CONVECTION HAS INCREASED ABOUT THIS WAVE OVERNIGHT...WITH SCATTERED TO LOCALLY NUMEROUS MODERATE TO STRONG CONVECTION FROM 06N TO 13N BETWEEN 108W AND 115W. WIDELY SCATTERED MODERATE TO STRONG CONVECTION ELSEWHERE FROM 03N TO 14N BETWEEN 101W AND 117W. COMPUTER MODEL GUIDANCE SUGGESTS THAT THE LOW WILL MOVE W-NW 15-20 KT OVER THE NEXT FEW DAYS WITH THE POTENTIAL FOR SLOW IMPROVEMENT IN ORGANIZATION. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH HAS GRADUALLY BECOME BETTER DEFINED OVER THE PAST 48 HOURS...AND CURRENTLY EXTENDS FROM 08.5N78W TO 09N86W TO 07.5N96W TO LOW PRES 07N110W 1009 MB TO 10N116W...WHERE IT BREAKS...THEN RESUMES FROM 08.5N129W TO BEYOND 11N141W. SCATTERED TO LOCALLY NUMEROUS MODERATE TO STRONG WITHIN 240 NM S OF AXIS BETWEEN 78W AND 88W. SCATTERED MODERATE TO STRONG WITHIN 24N NM N AND 180 NM S OF AXIS BETWEEN 93W AND 107W. ...DISCUSSION... A 1030 MB SUBTROPICAL HIGH WAS ANALYZED NW OF THE AREA NEAR 45N144W AND EXTENDED A RIDGE AXIS SE THROUGH 30N129W TO 18N114W. THE REMNANTS OF FELICIA WERE ANALYZED AS A 1015 MB LOW PRESSURE SYSTEM SW OF THE RIDGE CENTERED NEAR 24N125.5W MOVING W AROUND 10 KT. 05-0600 ASCAT PASSES SHOWED WINDS ONLY AS HIGH AS 20 KT ACROSS THE NW QUADRANT...WHERE SEAS WERE TO 8 FT. THE LOW IS FORECAST TO OPEN UP...BECOMING A TROUGH LATER TODAY AS IT CONTINUES WWD. WINDS TO 20 KT WITH 7-9 FT SEAS ARE EXPECTED TO PERSIST THROUGH TUE NEAR THE SYSTEM UNDER PRIMARILY SW SWELL. AS THE REMNANT LOW HAS WEAKENED...THE RIDGE HAS BUILT ACROSS THE NE WATERS AND ALONG THE OFFSHORE WATERS OF THE BAJA CALIFORNIA PENINSULA. AT THE SAME TIME...DEEP-LAYERED TROUGHING OVER THE SW UNITED STATES AND A MID-LEVEL LOW MEANDERING IN THE VICINITY OF THE SOUTHERN GULF OF CALIFORNIA FORCED MORE TROUGHING AT THE SURFACE. THIS INCREASED THE PRESSURE GRADIENT AND THE WINDS OFFSHORE OF THE BAJA CALIFORNIA PENINSULA THIS EVENING...BUT HAVE DIMINISHED TO 15-20 KT OVERNIGHT. MODERATE TO FRESH NW WINDS ARE EXPECTED TO RETURN MON EVENING...WITH SEAS BUILDING TO 8 FT. THE PRESSURE GRADIENT WILL SLACKEN BY TUE WHEN THE AFOREMENTIONED TROUGHING WEAKENS. THE PRESSURE GRADIENT BETWEEN THE SUBTROPICAL RIDGE AND LOWER PRESSURE ASSOCIATED WITH THE ITCZ OVER W WATERS HAS BROUGHT MODERATE TO FRESH TRADE WINDS TO THE AREA PRIMARILY N OF THE ITCZ W OF 125W. THIS AREA OF TRADES IS FORECAST TO SHIFT W OF THE AREA OVER THE NEXT TWO DAYS. SEAS WERE 7-9 FT IN NE WIND WAVES AND MIXED SE AND SW SWELL PRIMARILY FROM 10N TO 20N W OF 130W. THESE MARINE CONDITIONS SHOULD SUBSIDE BELOW 8 FT BY TUE MORNING. THE DEVELOPMENT OF THE MONSOON TROUGH IS EXPECTED TO MAINTAIN GOOD LOW LEVEL CONVERGENCE ABOUT THE TROUGH AXIS OVER THE NEXT FEW DAYS...AND COMBINE WITH FAVORABLE UPPER LEVEL CONDITIONS TO MAINTAIN ACTIVE TROPICAL CONVECTION W OF 90W THROUGH WED. GAP WINDS... GULF OF PAPAGAYO...A SOUTHERLY DISPLACED RIDGE AXIS IN THE SW N ATLC AND GULF OF MEXICO HAS INCREASED THE PRESSURE GRADIENT BETWEEN IT AND WEAK TROUGHING TO THE S OF THE GULF OF PAPAGAYO OFFSHORE NE WINDS ARE EXPECTED TO BRIEFLY PULSE TO 20-25 KT WITH THE ASSISTANCE OF NOCTURNAL DRAINAGE FLOW THROUGH EARLY THIS MORNING THEN AGAIN TONIGHT...WITH SEAS BUILDING TO 9 FT. $$ STRIPLING