000 AXPZ20 KNHC 260851 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SAT SEP 26 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 0830 UTC. ...SPECIAL FEATURES... A 1007 MB AREA OF LOW PRES IS EMBEDDED IN THE MONSOON TROUGH NEAR 12.5N91.5W MOVING WNW AT 11 KT. DISORGANIZED SCATTERED MODERATE CONVECTION IS WITHIN 75 NM IN THE NE QUADRANT OF THE LOW. RECENT SCATTEROMETER PASSES MISSED THE EASTERN HALF OF THE LOW WHERE THE STRONGEST WINDS ARE LIKELY OCCURRING. WINDS ARE RUNNING AROUND 20 KT CURRENTLY AND ARE FORECAST TO INCREASE TO 20-30 KT BY 24 HOURS WITH THE LOW TURNING TO THE NW AND THEN N BY 24-36 HOURS...AND EVENTUALLY NNE BEYOND THAT. SEAS ARE CURRENTLY 8-9 FT SE OF THE LOW AND WILL GRADUALLY BUILD TO 8-11 FT WHILE WRAPPING AROUND THE LOW THROUGH 48 HOURS. THIS LOW AS A HIGH CHANCE OF TROPICAL CYCLONE FORMATION IN THE NEXT 48 HOURS. ...TROPICAL WAVES... TROPICAL WAVE FROM 07N104W TO 16N106W MOVING W AT 10 KT. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 06N TO 14N BETWEEN 103W AND 108W. RECENT SCATTEROMETER PASSES INDICATED A WIND SHIFT AT THE SURFACE ALONG THE WAVE AXIS. TROPICAL WAVE FROM 03N138W TO 12N136W MOVING W AT 10 KT. SCATTERED MODERATE CONVECTION IS FROM 03N TO 12N W OF 135W. A RECENT RAPIDSCAT SCATTEROMETER PASS INDICATED A WIND SHIFT AT THE SURFACE ALONG THE WAVE AXIS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 10N84W TO LOW PRES NEAR 12.5N91.5W TO LOW PRES NEAR 11.5N103W TO 10N120W TO 09N134W. NO ITCZ AXIS IS PRESENT. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF THE AXIS BETWEEN 111W AND 121W. ...DISCUSSION... A 1006 MB AREA OF LOW PRES IS EMBEDDED IN THE MONSOON TROUGH NEAR 12.5N91.5W OR ABOUT 90 NM SW OF THE COASTS OF GUATEMALA AND EL SALVADOR AND IS NEARLY STATIONARY. NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION IS WITHIN 120 NM IN THE E SEMICIRCLE AND 45 NM IN THE W SEMICIRCLE OF THE LOW. RECENT SCATTEROMETER DATA INDICATED 20-25 KT WINDS NEAR THE LOW WITH SEAS TO 8 FT POSSIBLE. CURRENTLY TROPICAL CYCLONE FORMATION IS NOT EXPECTED IN THE NEXT 48 HOURS...HOWEVER THE LOW IS FORECAST TO MOVE LITTLE AND PERSISTENT CONVECTION MAY PRODUCE HEAVY RAINS ACROSS PORTIONS OF EL SALVADOR...SOUTHERN GUATEMALA AND SOUTHEASTERN MEXICO DURING THE NEXT FEW DAYS...ALONG WITH GUSTY WINDS ALONG THE COAST. THESE RAINS COULD CAUSE LIFE-THREATENING FLASH FLOODS AND MUDSLIDES. REFER TO STATEMENTS ISSUED BY YOUR LOCAL METEOROLOGICAL AGENCY FOR ADDITIONAL DETAILS. A SURFACE RIDGE EXTENDS SE FROM HIGH PRES NEAR 34N129W THROUGH 30N126W TO 21N121W. A STATIONARY FRONT IS NEAR THE NW CORNER OF THE DISCUSSION WATERS EXTENDING FROM 1015 MB LOW PRES NEAR 34N134W. THIS LOW IS FORECAST TO DEEPEN WHILE GRADUALLY MOVING SW DURING THE NEXT 24-48 HOURS WITH WINDS INCREASING TO GALE FORCE ON THE NW SIDE OF THE LOW JUST OUTSIDE OF THE DISCUSSION WATERS. THESE WINDS WILL GENERATE FRESH NW-N SWELL WHICH WILL MANAGE TO PROPAGATE INTO THE NW CORNER BY 36-48 HOURS. CROSS-EQUATORIAL SOUTHERLY SWELL WITH COMBINED SEAS OF 8-10 FT REMAINS IN THE S CENTRAL WATERS. THIS SWELL WILL LINGER ACROSS THE SAME GENERAL AREA THROUGH THE NEXT 48 HOURS WITH SEAS DECAYING SLIGHTLY TO 8-9 FT. GAP WINDS...AN ASCAT-B SCATTEROMETER PASS INDICATED 20-30 KT NORTHERLY WINDS IN THE GULF OF TEHUANTEPEC SUPPORTING SEAS OF 8- 11 FT. THESE WINDS WILL PERSIST THROUGH THE NEXT 24 HOURS... DIMINISHING BY 36 HOURS AS THE LOCAL PRES GRADIENT RELAXES SLIGHTLY. $$ LEWITSKY