000 AXPZ20 KNHC 202211 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SUN SEP 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 2130 UTC. ...SPECIAL FEATURES... THE ELONGATED AREA OF LOW PRES MOVING NORTHWARD AND JUST OFFSHORE OF BAJA CALIFORNIA SUR HAS BECOME SUFFICIENTLY ORGANIZED THIS AFTERNOON TO BE CLASSIFIED AS TROPICAL DEPRESSION SIXTEEN-E...LOCATED NEAR 25.0N 113.7W 1003 MB AT 2100 UTC AND MOVING NNW OR 345 DEG AT 12 KT. MAXIMUM SUSTAINED WINDS ARE 30 KT WITH GUSTS 40 KT...AS INDICATED BY AFTERNOON SCATTEROMETER DATA. SCATTERED STRONG CONVECTION IS OCCURRING WITHIN 180 NM ACROSS THE N SEMICIRCLE...WHILE ISOLATED TO SCATTERED MODERATE CONVECTION IS WITHIN 120 ACROSS THE S SEMICIRCLE. VERY ACTIVE CONVECTION CONTINUES ACROSS THE GULF OF CALIFORNIA AND ADJACENT LAND AREAS ON BOTH SIDES OF THE GULF...FROM 22N TO 30N...WHERE SCATTERED MODERATE TO STRONG CONVECTION PREVAILS. T.D. SIXTEEN-E IS EXPECTED TO MAINTAIN A NORTHWARD MOTION THIS EVENING AND TONIGHT...AND MOVE INLAND ACROSS CENTRAL BAJA CALIFORNIA OVERNIGHT...THEN RE-EMERGE ACROSS THE NORTHERN GULF OF CALIFORNIA MONDAY AND THEN INLAND AGAIN ACROSS THE STATE OF SONORA MEXICO MONDAY AFTERNOON. ATMOSPHERIC CONDITIONS...AND THE FORECAST INTERACTION WITH LAND DO NOT APPEAR TO PROVIDE CONDUCIVE CONDITIONS FOR STRENGTHENING. THE MAIN THREAT FOR THIS SYSTEM IS THE HEAVY RAINFALL THAT WILL OCCUR WITH AND WELL AHEAD OF THE DEPRESSION ACROSS BAJA CALIFORNIA...NW MAINLAND MEXICO...SOUTHERN CALIFORNIA...AND THEN ACROSS ARIZONA IN THE COMING DAYS. THESE RAINS COULD PRODUCE LIFE THREATENING FLASH FLOODS AND LEAD TO MUDSLIDES...ESPECIALLY ACROSS THE MOUNTAINOUS TERRAIN OF MEXICO. MARINE CONDITIONS WITHIN THE GULF OF CALIFORNIA HAVE DETERIORATED SIGNIFICANTLY DURING THE PAST 24 HOURS...AS SOUTH TO SOUTHEAST WINDS OF 20 TO 30 KT ARE RUNNING STRAIGHT UP THE GULF...AND HAVE GENERATED SEAS TO AROUND 9 FT THIS AFTERNOON. THESE CONDITIONS...WITH HIGHER WINDS AND SEAS NEAR SQUALLS AND THUNDERSTORMS WILL PERSIST ACROSS THE CENTRAL GULF AND SHIFT INTO THE N GULF TONIGHT THROUGH MONDAY. ...TROPICAL WAVES... A TROPICAL WAVE IS INVOF 100W-101W MOVING W 10-15 KT. ISOLATED MODERATE CONVECTION DOTS THE WATERS BETWEEN 95W AND 108W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR 08.5N75W TO 07N88W TO 09.5N116.5W WHERE IT REMAINS FRACTURED...THEN RESUMES FROM LOW PRES NEAR 16.5N116.5W TO 11.5N128W TO 12N134W TO BEYOND 10N140W. SCATTERED MODERATE TO STRONG WITHIN 90 NM N AND 180 NM S OF TROUGH BETWEEN 102W AND 116.5W. SCATTERED MODERATE TO STRONG WITHIN 60 NM N AND 150 NM S OF TROUGH BETWEEN 117W AND 139W. ...DISCUSSION... A 1026 MB HIGH CENTERED NW OF THE AREA NEAR 36N147W EXTENDS A RIDGE SE TO JUST W OF T.D. SIXTEEN-E...NEAR 25N123W. THE PRES GRADIENT BETWEEN THE RIDGE AND MONSOON TROUGH IS PRODUCING MODERATE TO FRESH NE TRADE WINDS OVER WESTERN PORTIONS OF THE AREA W OR 127W. THIS IS RESULTING IN SEAS TO 8 FT FROM FROM 12N TO 18N W OF 132W. THE HIGH PRES CENTER WILL SHIFT WESTWARD OVER THE NEXT 24 HOURS...WHICH WILL WEAKEN THE PRES GRADIENT OVER THE WESTERN WATERS AND RESULT IN DIMINISHED TRADE WINDS...WITH ASSOCIATED SEAS SUBSIDING TO BELOW 8 FT BY MONDAY. GAP WINDS...A PULSING OF WINDS WILL START LATE TONIGHT ACROSS THE GULF OF TEHUANTEPEC. WINDS WILL PEAK DURING THE OVERNIGHT AND EARLY MORNING HOURS NEAR 25 KT TONIGHT AND NEAR 30 KT MON NIGHT. WINDS WILL BE WEAKEST IN THE AFTERNOON AND EARLY EVENING HOURS WITH WINDS MAINLY IN THE 20 KT RANGE...WITH LOCALLY STRONGER WINDS TO NEAR 25 KT. $$ STRIPLING