000 AXPZ20 KNHC 241003 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SAT JAN 24 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 0945 UTC. ...SPECIAL FEATURES... A GALE WARNING IS IN EFFECT FOR THE GULF OF TEHUANTEPEC. N TO NE WINDS OF 30-35 KT HAVE JUST RECENTLY COMMENCED OVER THE FAR NORTHERN OF PART OF THE GULF AS STRONG HIGH PRES OF 1030 MB SETTLES IN OVER EASTERN MEXICO WITH ITS ASSOCIATED RIDGING SURGING SWD ACROSS SE MEXICO. COLD DENSE BEING USHERED IN BY THIS NORTHERLY FLOW WILL FUNNEL THROUGH THE CHIVELA PASS AND TO ACCELERATE ACROSS THE ISTMUS OF TEHUANTEPEC INTO LATE SUN NIGHT. THIS AIR MASS WILL MOVE OVER WARM 27.5-28.5 DEG CELSIUS SEA SURFACE TEMPERATURES. THE 30-35 KT WINDS WILL PEAK TO 40 KT THIS AFTERNOON INTO TONIGHT WITH SEAS BUILDING TO 18 FT. MODELS INDICATE THAT THIS WILL BE A LONG DURATION GALE FORCE GAP WIND EVENT AS THE STRONG RIDGING ACROSS EASTERN MEXICO WILL BE SLOW TO WEAKEN. A REINFORCING PUSH OF COLD AIR IS EXPECTED TO OCCUR ON MON FOLLOWED BY A STRONGER ONE ON WED. WINDS ARE FORECAST TO DIMINISH TO MINIMAL GALE FORCE SUN AFTERNOON AND EVENING... THEN INCREASE AGAIN TO 35-40 KT LATE SUN NIGHT INTO MON MORNING. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH AXIS EXTENDS FROM 05N77W TO 06N90W TO 07N101W. ITCZ AXIS EXTENDS FROM 07N101W TO 07N111W TO 07N120W TO 07N130W TO 07N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM S OF THE TROUGH BETWEEN 83W-87W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM S OF THE ITCZ BETWEEN 110W-115W. ...DISCUSSION... ALOFT...A WEAKENING UPPER LOW MOVING S IS CENTERED NEAR 18N127W. THE LOW IS EMBEDDED IN AN UPPER TROUGH THAT STRETCHES FROM THE SW U.S. SW TO ACROSS FAR NORTHERN BAJA CALIFORNIA AND TO THE LOW...AND CONTINUES SW FROM THERE TO NEAR 12N135W. A JET STREAM BRANCH EXTENDS ACROSS THE SOUTHERN PORTION OF THE TROUGH...AND NEWD TO ACROSS CENTRAL MEXICO. AMPLE UPPER LEVEL MOISTURE STREAMING ENE TO THE SE OF THE LOW IS BEING FURTHER ENHANCED BY UPPER DIVERGENCE E OF THE LOW AND TROUGH PRODUCING SCATTERED SHOWERS AND ISOLATED TSTMS FROM 16N-18N BETWEEN 115W-119W. THIS ACTIVITY IS SLOWLY MOVING EASTWARD. THE LOW IS FORECAST TO GRADUALLY LOSE ITS IDENTITY OVER THE NEXT 12-18 HOURS AS A STRONGER CUT-OFF LOW DEVELOPS JUST W OF NORTHERN BAJA CALIFORNIA. MODELS SUGGEST THAT A PIECE OF ENERGY IN THE FORM OF DEEP ATMOSPHERIC MOISTURE WILL SEPARATE FROM THE AFOREMENTIONED AREA OF SCATTERED SHOWERS AND ISOLATED TSTMS AS MENTIONED ABOVE ...AND TRACK GENERALLY NEWD TO NEAR 21N115W BY LATE SUN NIGHT BEFORE WEAKENING TO A TROUGH MON. AT THE SURFACE...A 1030 MB HIGH PRES WELL N OF THE AREA NEAR 40N128W EXTENDS A RIDGE SOUTHWARD TO COVER MOST OF THE DISCUSSION AREA N OF 18N. A WEAK SURFACE TROUGH...ASSOCIATED WITH THE AFOREMENTIONED UPPER LOW NEAR 18N127W...EXTENDS FROM 18N131W TO 12N137W. AN ASCAT PASS FROM 0654 UTC THIS MORNING REVEALED AN AREA OF FRESH TO STRONG NE WINDS FROM 16N TO 21N W OF THE TROUGH DUE TO THE PRES GRADIENT BETWEEN THE HIGH PRES TO THE N AND THE TROUGH. MODERATE TO FRESH WINDS ARE NOTED ELSEWHERE ACROSS THE SOUTHERN PERIPHERY OF THE RIDGE. AN AREA OF LARGE LONG PERIOD NW SWELL...ASSOCIATED WITH A COLD FRONT IN THE CENTRAL PACIFIC N OF HAWAII...IS PROPAGATING SEWD THROUGH THE NW WATERS. THESE SWELLS ARE RESULTING IN MAX COMBINED SEAS OF 12 FT WITH PERIODS OF 16-18 SEC. THE COLD FRONT WILL ENTER THE FAR NW PORTION OF THE AREA LATE SUN NIGHT ALONG A POSITION ROUGHLY FROM NEAR 30N138W TO 26N140W. WINDS ASSOCIATED WITH THIS FRONT ARE EXPECTED TO BE 20 KT OR LESS...HOWEVER THE EXTENSIVE SWELL TRAIN PROPAGATING FROM THE NW IS FORECAST TO BE SITUATED TO THE W OF A LINE FROM NEAR 30N126W TO 19N130W TO 10N140W WITH ASSOCIATED SEAS OF 8-11 FT. HIGH PRES BUILDING OVER THE SOUTHWEST U.S. IN COMBINATION WITH A SURFACE TROUGH ACROSS NW MEXICO HAS TIGHTENED THE PRES GRADIENT IN THE GULF OF CALIFORNIA. WINDS ARE PRESENTLY FRESH TO STRONG FROM 25N TO 30N WITH SEAS LESS THAN 8 FT. THESE WINDS ARE EXPECTED TO DIMINISH TO 20 KT OR LESS BY LATE TONIGHT. GAP WINDS... FRESH TO LOCALLY STRONG WINDS ARE EXPECTED TO INCREASE TO 25 KT TONIGHT AND INTO SUN MORNING THROUGH THE GULF OF PAPAGAYO AS HIGH PRES BUILDS ACROSS THE WESTERN CARIBBEAN. THESE WINDS ARE FORECAST TO LAST INTO LATE SUN. FRESH NORTHERLY WINDS ARE FORECAST THROUGH THE GULF OF PANAMA SAT NIGHT INTO SUN MORNING BEFORE DIMINISHING SUN AFTERNOON...AND STARTING BACK UP SUN NIGHT INTO EARLY MON. $$ AGUIRRE