000 AXPZ20 KNHC 120945 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC TUE NOV 12 2013 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 FEATURE... GULF OF TEHUANTEPEC...CURRENT MINIMAL GALE FORCE WINDS ARE EXPECTED TO GRADUALLY INCREASE TODAY AND TONIGHT REACHING MINIMAL STORM FORCE ON WED WITH THESE STORM FORCE CONDITIONS PERSISTING THROUGH THE MAXIMUM DRAINAGE LATE WED NIGHT. WINDS WILL THEN DIMINISH THROUGHOUT THU WITH A MAXIMUM OF 25 KT EXPECTED AT SUNSET FRI. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS W-NW ACROSS THE GULF OF PANAMA DISSECTING PANAMA TO THE PACIFIC COAST OF COSTA RICA AT 09N84W... CONTINUING NW TO 10N87W...THEN TURNS SW TO 08N97W WHERE IT THEN WIGGLES WESTWARD BETWEEN 07-09N TO 08N126W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN ITCZ AXIS...WHICH IN TURN CONTINUES W TO BEYOND 08N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED OVER THE GULF OF PANAMA WITHIN 45 NM OF 08N79W...WHERE FREQUENT LIGHTNING IS CURRENTLY DETECTED. SIMILAR CONVECTION IS NOTED ALONG THE MONSOON TROUGH WITHIN 180 NM EITHER SIDE OF A LINE FROM 07N109W TO 12N125W. ISOLATED MODERATE CONVECTION IS OBSERVED WITHIN 90 NM OF THE MONSOON TROUGH BETWEEN 85-107W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED WELL N OF THE MONSOON TROUGH WITHIN 75 NM OF CLUSTERS AT 13N91W AND 13N104W. BROKEN TO OVERCAST LOW/MID LEVEL CLOUDS...WITH ONLY EMBEDDED WEAK SHOWERS...IS NOTED ACROSS THE DEEP TROPICS ELSEWHERE FROM 09N TO THE EQUATOR FROM THE S AMERICA COAST WESTWARD TO ALONG 126W...AND ALSO WITHIN 240 NM OF THE ITCZ AXIS. ...DISCUSSION... A LONGWAVE UPPER RIDGE DOMINATES WESTERN N AMERICA ORIGINATING FROM A LARGE UPPER ANTICYCLONE QUASI-STATIONARY OVER THE CAYMAN ISLANDS IN THE NW CARIBBEAN. AN UPPER LEVEL EMBEDDED SHORTWAVE TROUGH IS SWINGING E THROUGH THE LONGWAVE RIDGE PATTERN... CURRENTLY EXTENDING FROM THE TEXAS PANHANDLE SOUTHWARD ACROSS NW OLD MEXICO...TO OVER THE SOUTHERN GULF OF CALIFORNIA TO 114N110W...AND TERMINATING IN AN UPPER CYCLONE OVER THE DEEP TROPICAL PACIFIC AT 05N107W. THIS UPPER TROUGH EFFECTIVELY SEPARATES THE UPPER ANTICYCLONIC FLOW OVER TROPICAL PORTION OF THE DISCUSSION AREA. DRY UPPER AIR IS INDICATED N OF 22N WITHIN 480 NM W OF THE TROUGH AXIS...AND WITHIN 1200 NM W OF THE TROUGH AXIS FROM 10-22N. AN UPPER ANTICYCLONE IS CENTERED NEAR 10N136W WITH A SHORTWAVE RIDGE AMPLIFYING N THROUGH 32N121W...AND CONTINUING N-NE ACROSS ALL OF WESTERN N AMERICA. AN UPPER RIDGE ALSO EXTENDS E FROM THIS ANTICYCLONE TO 16N113W...AND IS CONTRIBUTING TO DRY UPPER AIR OVER THE TROPICS PREVIOUSLY DISCUSSED. LOOKING FURTHER N...A LONGWAVE TROUGH DOMINATES THE PACIFIC BETWEEN 130-180W WITH SEVERAL EMBEDDED CYCLONES. ONE DEEP LAYERED CYCLONE IS CENTERED NEAR WITH ITS CYCLONIC ENVELOPE EXTENDING E OVER THE NW PORTION OF THE DISCUSSION AREA. DENSE UPPER MOISTURE...ORIGINATING IN THE CENTRAL PACIFIC...AND REINFORCED BY ITCZ CONVECTION BETWEEN 142-152W...IS STREAMING NE ACROSS THE DISCUSSION AREA IN THE STRONG UPPER SOUTHWESTERLY FLOW...ROUGHLY WITHIN 300 NM EITHER SIDE OF A LINE FROM 21N140W TO OVER SOUTHERN CALIFORNIA AT 35N. AN UPPER RIDGE EXTENDS SW FROM THE CARIBBEAN UPPER ANTICYCLONE PREVIOUSLY MENTIONED NEAR THE CAYMAN ISLANDS TO A FAIRLY SHARP CREST OVER THE DEEP TROPICAL PACIFIC AT 14N107W. UPPER DIFFLUENCE CONTINUES TO ENHANCE PEAK-HEATING CONVECTION OVER THE SW CARIBBEAN...AND OVER INTERIOR CENTRAL AMERICA...WITH THE DECAYING CLUSTERS MOVING W OFF THE PACIFIC COAST OF CENTRAL AMERICA EACH NIGHT. OVERALL THE ENHANCED CONVECTION HAS DECREASED SIGNIFICANTLY THE PAST COUPLE OF DAYS. HOWEVER...THE UPPER LEVELS STILL APPEAR FAIRLY MOIST OVER CENTRAL AMERICA TO THE E OF 102W...AND OVER THE TROPICAL PACIFIC WITHIN 180 NM OF 15N104W. WESTERN BAJA CALIFORNIA PENINSULA...NW 10-15 KT WINDS WITH SEAS 3-6 FT...PRIMARILY IN MIXING LONG PERIOD NW AND CROSS EQUATORIAL S SWELL...ARE EXPECTED EARLY TODAY...THEN INCREASING BRIEFLY TO 15-20 KT ACROSS THESE COASTAL PACIFIC WATERS TO THE N OF 27N TONIGHT. GUIDANCE RELAXES THE GRADIENT SUPPORTING ONLY 5-10 KT WED THROUGH FRI...THEN BACKING TO THE SW AT 10 KT FRI NIGHT INTO EARLY SAT. A COLD FRONT WILL MOVE ACROSS THE PACIFIC COASTAL WATERS N OF 27N ON SAT FOLLOWED BY W-NW WINDS AT 15-20 KT...WITH SEAS BUILDING 7-10 FT ON SAT NIGHT...AND CONTINUING THROUGH EARLY MON MORNING BEFORE BEGINNING TO SUBSIDE. GULF OF CALIFORNIA...NW WINDS AT 10-15 KT ARE EXPECTED ACROSS THE GULF WATERS TODAY...EXCEPT BRIEFLY INCREASING TO 20 TO 25 KT ACROSS THE WATERS N OF 29N LATE TODAY...AND CONTINUING THROUGH THIS EVENING. EXPECT THE ASSOCIATED SEAS TO BUILD BRIEFLY TO ABOUT 6 FT IN THE OPEN FETCH WATERS. GUIDANCE THEN SUGGESTS THE GRADIENT WILL RELAX SUPPORTING NW 10-15 KT THROUGH LATE WED NIGHT WHEN THE NW WINDS WILL FURTHER DIMINISH TO 5-10 KT. THESE LIGHT WINDS WILL BECOME SOUTHERLY AT 5-10 KT ON FRI...INCREASING TO 10-15 KT EARLY SAT. THE SW WINDS WILL FURTHER INCREASE TO 20- 25 KT OVER THE FAR NORTHERN GULF WATERS ON SAT AFTERNOON IN ADVANCE OF A COLD FRONT ARRIVING LATE SAT NIGHT. GULF OF PAPAGAYO...NE WINDS ARE EXPECTED TO SURGE ACROSS THE GULF OF PAPAGAYO AT 15-20 KT WITH SEAS TO 4-6 FT THROUGH SUNRISE ON WED. THEREAFTER...NE 5-10 KT WINDS EXPECTED...EXCEPT INCREASING BRIEFLY TO 10-15 KT LATE EACH NIGHT THROUGH SUNRISE EACH MORNING...WITH THIS PATTERN CONTINUING THROUGH THE UPCOMING WEEKEND. ELSEWHERE AT THE SURFACE...THE REMNANTS OF A COLD FRONT ARE CURRENTLY DISSIPATING FROM 32N131W TO 25N137W. COMBINED SEAS ARE 7-9 FT TO THE N OF 28N WITHIN 150 NM OF THIS DECAYING FRONT... PRIMARILY DUE TO POST-FRONTAL NW SWELL MIXING WITH CROSS EQUATORIAL SE SWELL. THESE SEAS SHOULD SUBSIDE BELOW 8 FT THIS MORNING ACROSS THE DISCUSSION WATERS TO THE S OF 32N. A SURFACE RIDGE WILL STRENGTHEN ACROSS THE DISCUSSION AREA E OF THIS DISSIPATING FRONT TODAY WITH NE TRADES INCREASING TO 15-20 KT/SEAS 6-8 FT ACROSS THE TROPICS FROM 10-20N BETWEEN 112-140W. EXPECT THE GRADIENT TO FURTHER TIGHTEN SUPPORTING NE 20-25 KT TRADES NEAR 10N130W ON WED. NORTHERLY 10-15 KT WINDS WILL INCREASE TO 15-20 KT ACROSS THE DISCUSSION WATERS N OF 25N E OF 128W ON WED...INCREASING TO 20-25 KT ON THU...WITH THE AFFECTED AREA TO THE N OF 25N BETWEEN 120-135W ON FRI AND SAT...WITH SEAS BUILDING TO 12 FT NEAR 29N135W ON SAT. $$ NELSON