000 AXPZ20 KNHC 232131 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC TUE DEC 23 2014 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 2100 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC...A COLD FRONT WILL MOVE ACROSS THE WESTERN GULF OF MEXICO THROUGH WED NIGHT. GAP WINDS INTO THE GULF OF TEHUANTEPEC WINDS WILL INCREASE TO 20 TO 25 KT BY WED AFTERNOON...THEN FURTHER INCREASE TO GALE FORCE WED EVENING AS A COOLER AND DENSER AIR MASS FUNNELS ACROSS THE ISTHMUS. GALE FORCE WINDS WILL PERSIST INTO THU MORNING THEN DIMINISH. SEAS WILL BUILD TO AROUND 18 FT BY EARLY ON THU. MODEL GUIDANCE SHOWS WINDS DIMINISHING TO BELOW 20 KT ON FRI. NE SWELLS IN EXCESS OF 8 FT WILL PROPAGATE SW AWAY FROM THE GULF AFTER THE ONSET OF THE GALE EVENT...AND REACH TO NEAR 101W FROM 10N TO 14N BETWEEN 95W AND 101W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 07N78W TO 07N81W TO 09N85W TO 07N91W. THE ITCZ EXTENDS FROM 07N91W TO 06N97W TO 07N121W TO 05N140W. SCATTERED MODERATE CONVECTION IS FROM 03N TO 07N BETWEEN 103W AND 112W. ...DISCUSSION... UPPER LEVELS...A SHARP UPPER LEVEL TROUGH EXTENDS FROM NORTH- CENTRAL MEXICO SW TO AN UPPER LEVEL LOW NEAR 14N111W AND SW TO A BASE NEAR 07N115W. THE DEPTH OF THE TROUGHING IS SUPPORTIVE OF A SURFACE TROUGH ANALYZED FROM 08N111W TO 15N110W THAT IS PROVIDING FOCUS FOR SCATTERED MODERATE CONVECTION ALONG AND NORTH OF THE ITCZ FROM 03N TO 17N BETWEEN 99W AND 112W. A LARGE PORTION OF THIS CONVECTION IS AIDED BY MAXIMUM UPPER DIVERGENCE OCCURRING TO THE E OF THE UPPER LEVEL LOW. THIS CONVECTION WILL CONTINUE TO PULSE THROUGH WED AS THE UPPER CYCLONE REMAINS NEARLY STATIONARY. NW OF THE TROUGH...BROAD ANTICYCLONIC FLOW ALOFT COVERS THE AREA FOCUSED ON A MIDDLE TO UPPER LEVEL RIDGE CENTERED NEAR 26N128W. MOSTLY DRY AND STABLE AIR IS NOTED ACROSS MUCH OF THE DISCUSSION AREA W OF 110W AND OUTSIDE OF THE INFLUENCE OF THE UPPER LEVEL LOW DISCUSSED ABOVE. AT THE SURFACE...A 1029 MB HIGH PRES CENTER SUPPORTED BY THE UPPER LEVEL ANTICYCLONIC FLOW ALOFT IS ANALYZED N OF THE AREA NEAR 36N132W WITH A RIDGE STRETCHING SE TO 20N112W AND SW TO 30N142W. THE INDUCED PRES GRADIENT IS SUPPORTING FRESH TO STRONG TRADE WINDS ACROSS THE WESTERN PORTION FROM 07N TO 13N W OF 125W PER LATEST SCATTEROMETER DATA. OTHERWISE...8 TO 11 FT SEAS PRIMARILY IN NW SWELLS ARE NOTED W OF A LINE FROM 30N115W TO 23N115W TO 00N128W AND WILL SLOWLY SUBSIDE THROUGH THU...HOWEVER A NEW SET OF NW SWELLS RAISING SEAS TO 12 FT WILL PROPAGATE INTO THE FAR NE CORNER OF THE AREA THU. GAP WINDS... GULF OF CALIFORNIA...STRONG HIGH PRES WILL BUILD N OF THE REGION OVER THE GREAT BASIN THROUGH LATE WED INDUCING A TIGHT PRES GRADIENT THAT IS EXPECTED TO BRING STRONG TO POSSIBLY NEAR GALE FORCE NW WINDS OVER MUCH OF THE NORTHERN AND CENTRAL PORTIONS OF THE GULF OF CALIFORNIA THROUGH TONIGHT. AS THE GRADIENT BEGINS TO RELAX WED MORNING...THE WINDS ARE EXPECTED TO DIMINISH TO 20 KT OR LESS BY WED EVENING. SEAS IN THE GULF ARE FORECAST TO BUILD TO OR AROUND 8 FT ACROSS PORTIONS OF THE CENTRAL AND SOUTHERN GULF OF CALIFORNIA TONIGHT. THESE SEAS WILL QUICKLY SUBSIDE TO LESS THAN 8 FT BY EARLY WED AFTERNOON AS WINDS DIMINISH. GULF OF PAPAGAYO...MODEL GUIDANCE INDICATES THAT THE NEXT NE 20-25 KT SURGE THROUGH THE GULF WILL BEGIN LATE ON THU INTO EARLY FRI. $$ HUFFMAN