000 AXPZ20 KNHC 202154 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC MON JUL 20 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2145 UTC. ...SPECIAL FEATURES... A 1009 MB SURFACE LOW IS ANALYZED NEAR 13N109.5W AND IS MOVING NW AT 6 KT. SCATTERED MODERATE ISOLATED STRONG CONVECTION CONTINUES WITHIN 360 NM W OF THE CENTER WITH INTERMITTENT BANDING FEATURES. UPPER LEVEL WIND SHEAR HAS PERSISTED LONGER THAN EXPECTED AND PREVENTED THE ANTICIPATED TROPICAL CYCLONE FORMATION. THIS WIND SHEAR IS STILL FORECAST TO WEAKEN AND THERE IS A VERY HIGH PROBABILITY OF TROPICAL CYCLONE FORMATION WITHIN THE NEXT DAY OR SO. CYCLONIC 20-30 KT WINDS ARE OBSERVED WITHIN 150 NM E AND WITHIN 120 NM OVER THE W SEMICIRCLES OF THE CENTER. THE LOW...OR POSSIBLE TROPICAL CYCLONE IS FORECAST TO MOVE TO NEAR 14N112W 1007 MB ON TUE WITH CYCLONIC WINDS INCREASING TO 30- 35 KT MINIMAL GALE FORCE WITHIN 45 NM OF CENTER...WITH SEAS BUILDING TO 14 FT. THE LOW...OR POSSIBLE CYCLONE IS FORECAST TO REACH NEAR 15N114.5W 1004 MB ON WED WITH 30-40 KT GALE CONDITIONS WITHIN 75 NM OF CENTER EXCEPT WITHIN 45 NM OVER THE SW QUADRANT...AND SEAS BUILDING 12-16 FT. SEE LATEST HIGH SEAS FORECAST UNDER WMO/AWIPS HEADERS FZPN03 KNHC/MIAHSFEP1 FOR ADDITIONAL DETAILS. ...LOWS AND TROPICAL WAVES... THE REMNANT LOW PRESSURE OF DOLORES IS LOCATED NEAR 31N121W AND IS ANALYZED AT 1012 MB. THERE IS NO SIGNIFICANT CONVECTION AND ASSOCIATED SURFACE WINDS HAVE DIMINISHED TO 10-15 KT. THE LOW WILL MOVE OF THE AREA TONIGHT. THE REMNANT LOW OF ENRIQUE IS ANALYZED AT 1010 MB NEAR 21N136W AND IS MOVING SLOWLY W-NW. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 75 NM E OF THE CENTER. SURFACE WINDS OF 10-15 KT CONTINUE WITHIN 210 NM OVER THE N SEMICIRCLE WITH SEAS OF 6-8 FT PRIMARILY DUE TO MIXING SWELLS. THE LOW IS FORECAST TO MOVE W OF THE AREA ON TUE. A TROPICAL WAVE IS ANALYZED FROM 07-16N ALONG 99W WITH ISOLATED MODERATE AND STRONG CONVECTION NOTED WITHIN 210 NM E AND WITHIN 150 NM W OF THE WAVE AXIS. A TROUGH EXTENDS FROM 11N117W TO 18N120W WITH SCATTERED MODERATE ISOLATED STRONG CONVECTION OBSERVED S OF 14N WITHIN 90 NM OF TROUGH. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A WEAK SURFACE TROUGH ORIGINATES FROM A 1009 MB SURFACE LOW OVER NW COLOMBIA AT 09N76W AND EXTENDS WSW ACROSS THE GULF OF PANAMA AND IS ACCOMPANIED BY SCATTERED MODERATE TO STRONG CONVECTION. SCATTEROMETER WINDS SUGGEST THAT A WEAK MONSOON TROUGH DEVELOPS JUST W OF THE TROPICAL LOW AT 13N109.5W...AND EXTENDS SW TO 09N124W WHERE IT TRANSITIONS TO AN ITCZ WHICH CONTINUES WSW TO BEYOND 07N140W. EXCEPT AS PREVIOUSLY DESCRIBED WITH THE TROPICAL LOW AND TROPICAL WAVES...SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 180 NM ETHER SIDE OF A LINE FROM 07N78W TO 06N104W...S OF THE MONSOON TROUGH WITHIN 120 NM EITHER SIDE OF A LINE FROM 08N119W TO 02N132W...AND OVER AND TO THE S OF THE ITCZ WITHIN 90 NM EITHER SIDE OF A LINE FROM 07.5N134W TO 06N140W. ...DISCUSSION... CROSS EQUATORIAL SOUTHERLY SWELL IS MIXING WITH NW SWELL RESULTING IN COMBINED SEAS OF 6-9 FT SEAS ACROSS THE TROPICS S 05N BETWEEN 105-130W. THESE ENHANCED SEAS ARE EXPECTED TO MOVE N REACHING THE COAST OF CENTRAL AMERICA ON WED NIGHT THROUGH EARLY THU NIGHT. GULF OF PAPAGAYO...GUIDANCE HAS BACKED OFF SOMEWHAT AND NOW EXPECT E-NE 15 KT DRAINAGE TONIGHT WITH SEAS TO ONLY 7 FT. DRAINAGE WINDS OF 15-20 KT ARE EXPECTED TO RESUME ON WED NIGHT RESULTING IN A SWATH OF 6-8 FT PROPAGATING WSW TO NEAR 10.5N90W ON THU MORNING. $$ NELSON