000 AXPZ20 KNHC 231005 RRA TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC FRI JAN 23 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 FORECAST TO COMMENCE AT 06 UTC ON JAN 24 HAS BEEN ISSUED FOR THE GULF OF TEHUANTEPEC. A COLD FRONT MOVING THROUGH THE FAR WESTERN GULF OF MEXICO EARLY THIS MORNING WILL SWEEP SEWD THROUGH THE REST OF THE GULF THROUGH EARLY ON SAT. THIS COLD FRONT WILL BE FOLLOWED BY STRONG HIGH PRES THAT WILL SURGE SOUTHWARD ALONG THE SIERRA MADRE ORIENTAL MOUNTAINS OF MEXICO. THE COLD DENSE AIR MASS USHERED IN BY THE RIDGE WILL SPILL SOUTHWARD THROUGH THE CHIVELA PASS...AND OUT ACROSS THE GULF OF TEHUANTEPEC WHERE SEA SURFACE TEMPERATURES ARE 27.5-28.5 DEG CELSIUS. THIS WILL ALLOW FOR MIXING OF THE COLD DENSE AIR OVER THESE VERY WARM WATERS WITH N WINDS OF 30-35 KT EXPECTED WITHIN 30 NM OF A LINE FROM 16N95W TO 15N95W TO 14.5N95.5W BY 06 UTC ON JAN 24...AND FURTHER INCREASING TO 40 KT BY 12 UTC THAT SAME DAY WITH SEAS QUICKLY BUILDING TO 9-14 FT AND TO 10-18 FT BY LATE SAT NIGHT. N-NE WINDS OF 20-30 KT WILL BE EVIDENT ELSEWHERE WITHIN 75 NM OF A LINE FROM 16N95W TO 15N95W TO 12.5N98W BY LATE FRI NIGHT...AND WITHIN 75 NM OF A LINE FROM 16N95W TO 15N95W TO 12N100W BY LATE SAT NIGHT WITH SEAS IN THE RANGE OF 9-14 FT. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 09N84W TO 06N95W. ITCZ AXIS EXTENDS FROM 06N95W TO 06N105W TO 06BN115W TO 05N125W TO 06N140W. NO SIGNIFICANT CONVECTION IS NOTED. ...DISCUSSION... ALOFT...A VERY NOTICEABLE UPPER-LEVEL LOW IS CENTERED NEAR 19N127W. THE LOW IS EMBEDDED IN AN UPPER TROUGH THAT STRETCHES FROM EASTERN NEVADA SW TO THE FAR NE CORNER OF THE AREA...TO THE LOW AND CONTINUES SW TO NEAR 10N139W. A JET STREAM BRANCH EXTENDS ACROSS THE SOUTHERN PORTION OF THE TROUGH...AND NE 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 PRODUCING SCATTERED SHOWERS AND TSTMS FROM 14N-18N BETWEEN 116W-121W. THIS ACTIVITY IS SLOWLY SHIFTING EASTWARD. THE LOW IS FORECAST TO REMAIN NEARLY STATIONARY OVER THE NEXT 24 HOURS...THEN WILL DISSIPATE AS A STRONGER CUT-OFF LOW DEVELOPS OVER NW MEXICO AND NORTHERN BAJA CALIFORNIA. AT THE SURFACE...A TROUGH EXTENDING FROM 21N128W TO 15N131W IS SUPPORTED BY THE UPPER LOW NEAR 19N127W. TO ITS N...A 1029 MB HIGH PRES CENTER IS ANALYZED N OF THE AREA AT 38N128W WITH A RIDGE SW TO 32N138W...AND CONTINUING SW TO JUST E OF THE HAWAIIAN ISLANDS. ANOTHER RIDGE EXTENDS FROM THE HIGH CENTER SE TO NEAR 21N112W. THE 0538 UTC ASCAT PASS REVEALED A SWATH OF NE 20 KT WINDS BETWEEN THE TROUGH AND THE FIRST RIDGE. THE TROUGH OS FORECAST TO CONTINUE ON A WESTWARD TRACK THROUGH THE NEXT 24- 48 HRS WITH THE TIGHT GRADIENT OF 20 KT PRECEDING IT WITHIN ABOUT 180 NM TO ITS W AND NW. MODELS SUGGEST THAT A PIECE OF ENERGY IN THE FORM OF DEEP ATMOSPHERIC MOISTURE WILL SEPARATE FROM THE AFOREMENTIONED AREA OF SCATTERED SHOWERS AND TSTMS E OF THE UPPER LOW...AND TRACK GENERALLY NEWD TO NEAR 20N112W BY 48 HRS. PRESENTLY THIS SCENARIO IS BEING DEPICTED AS A TROUGH ON THE SURFACE PROGS...BUT MAY A WEAK LOW AS WELL. THE HIGH PRES CENTER WILL REMAIN NEARLY STATIONARY DURING THE NEXT 24 HOURS. LONG PERIOD NW SWELLS...WITH A LEADING EDGE PERIOD OF 21 TO 23 SECONDS...ARE ALREADY IMPACTING THE NW WATERS WITH SIGNIFICANT WAVE HEIGHTS OF 12-13 FT. BY FRI MORNING...THE NW SWELL WILL CONTINUE TO PUSH INTO THE FORECAST WATERS WITH SEAS OF 12-14 FT AFFECTING THE AREA N OF 16N W OF 132W. THE COLD FRONT ASSOCIATED WITH THIS SWELL EVENT IS NOT EXPECTED TO REACH THE AREA UNTIL LATE ON SUN. HIGH PRES BUILDING OVER THE SOUTHWEST U.S. WILL COMBINE WITH A SURFACE TROUGH ACROSS NW MEXICO TO TIGHTEN THE PRESSURE GRADIENT IN THE GULF OF CALIFORNIA. THE MOST RECENT SCATTEROMETER PASS INDICATED FRESH TO STRONG FROM 25N TO 30N. THESE WINDS WILL SPREAD SOUTHWARD TO ENCOMPASS MOST OF THE GULF OF CALIFORNIA THROUGH FRI...WITH FRESH NW WINDS FORECAST TO BE CONFINED THE FAR NORTHERN PORTION OF THE GULF BY EARLY ON SUN. GAP WINDS... FRESH TO LOCALLY STRONG WINDS ARE EXPECTED ACROSS THE GULF OF PAPAGAYO UNTIL 1200 UTC WITH SEAS OF AROUND 6 FT THROUGH AND DOWNWIND OF THE GULF. WINDS WILL INCREASE AGAIN TO 20-25 KT SAT NIGHT INTO SUN MORNING AS HIGH PRES BUILDS ACROSS THE NW CARIBBEAN. $$ AGUIRRE