000 AXPZ20 KNHC 100947 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SUN NOV 10 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 CONTINUE THROUGH MAXIMUM DRAINAGE AROUND SUNRISE THIS MORNING...THEN DIMINISH TO A MAXIMUM OF 30 KT BY NOON TODAY. THE NORTHERLY FLOW WILL CONTINUE TO SURGE TO 30 KT THROUGH THIS EVENING. THE NORTHERLY WINDS ARE EXPECTED TO INCREASE AGAIN TO MINIMAL GALE FORCE LATE TONIGHT AND CONTINUE THROUGH SUNRISE ON MON. THE GRADIENT THEN RELAXES SLIGHTLY WITH SURGES TO 30 KT THROUGH LATE TUE WHEN THE NORTHERLY FLOW IS EXPECTED TO BEGIN TO INCREASE TO MINIMAL GALE FORCE TUE NIGHT PRIOR TO THE NORMAL MAXIMUM DRAINAGE AROUND SUNRISE ON WED. GUIDANCE SUGGESTS THE NORTHERLY FLOW WILL GRADUALLY INCREASE THROUGHOUT THE DAY WED WITH STRONG GALE WINDS OF 35-45 KT ACROSS A LARGE SWATH DOWNSTREAM OF THE GULF OF TEHUANTEPEC TO NEAR 13N96W LATE WED NIGHT. THIS WOULD RESULT IN A STORM WARNING FOR FREQUENT GUSTS OF 50-60 KT...ACCOMPANIED BY SEAS OF 15-20 FT... BY LATE WED...AND CONTINUING THROUGH SUNRISE ON THU. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS W FROM THE CARIBBEAN COAST OF COLOMBIA AT 09N76W ACROSS THE CARIBBEAN APPROACH TO THE PANAMA CANAL...CONTINUING W ACROSS EXTREME N PANAMA AND THE PANAMA/COSTA RICA BORDER TO THE PACIFIC COAST OF COSTA RICA AT 10N84W...THEN WIGGLES WESTWARD BETWEEN 08-10N TO 10N94W...THEN DIPS SW TO 08N110W...THEN TURNS NW THROUGH AN EMBEDDED 1008 MB LOW PRES AT 11N116.5W TO 13N125W WHERE IT TURNS SW AGAIN THROUGH ANOTHER EMBEDDED 1008 MB LOW PRES AT 11.5N127.5W...CONTINUING SW TO 09N130W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN ITCZ AXIS...WHICH IN TURN CONTINUES W TO BEYOND 11N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS DISSIPATING PARALLEL TO THE COAST OF CENTRAL AMERICA WITHIN 45 NM EITHER SIDE OF A LINE FROM 10N86W TO 14N92W. SIMILAR CONVECTION IS NOTED WITHIN 45 NM EITHER SIDE OF A LINE FROM THE MONSOON TROUGH AT 08N102W TO 15N100W. A N-S ORIENTATED TROUGH IS INDICATED IN THE SCATTEROMETER WINDS EXTENDING N FROM THE EMBEDDED SURFACE LOW AT 11N116.5W TO 17N117W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED TO THE E OF THIS TROUGH...ROUGHLY WITHIN 60 NM OF 16N115.5W AND NE OF THE LOW WITHIN 30 NM OF 12.5N114.5W. SMALL CLUSTERS OF ISOLATED MODERATE...TO OCCASIONALLY STRONG... CONVECTION IS NOTED ELSEWHERE ALONG THE EASTERN SEGMENT MONSOON TROUGH...WITHIN ABOUT 120 NM EITHER SIDE OF A LINE FROM 08N85W 09N96W TO 08N110W TO 08N121W. BROKEN TO OVERCAST LOW/MID LEVEL CLOUDS...WITH ONLY EMBEDDED WEAK SHOWERS...ARE NOTED ACROSS THE DEEP TROPICS FROM 08N TO THE EQUATOR FROM THE S AMERICA COAST TO ALONG 120W...AND WITHIN 120 NM S OF THE ITCZ. ...DISCUSSION... A LONGWAVE UPPER RIDGE DOMINATES WESTERN N AMERICA EXTENDING NW FROM A LARGE UPPER ANTICYCLONE QUASI-STATIONARY OVER THE NW CARIBBEAN AT 20N87W. AN UPPER LEVEL SHORTWAVE TROUGH IS SWINGING NE THROUGH THE LONGWAVE PATTERN...ROUGHLY FROM 34N126W TO OVER THE TROPICAL PACIFIC AT 15N112W. DRY UPPER AIR IS INDICATED N OF 24N WITHIN 240 NM W OF THE TROUGH AXIS. HOWEVER...THE UPPER TROUGH IS PRECEDED BY DEBRIS MOISTURE WITHIN 480 NM E OF THE ITS AXIS...AND IS SUPPORTING AN AREA OF CONVECTION THAT LACKS LIGHTNING ATTM...WITHIN 150 NM OF 32N119W. THIS CONVECTION WILL PASS NE ACROSS SOUTHERN CALIFORNIA THIS MORNING. FURTHER S... THE EASTERN EXTENT OF THIS THINNING MOISTURE WILL SPREAD NE ACROSS THE TEXAS PANHANDLE TODAY. AN UPPER ANTICYCLONE IS CENTERED NEAR 05N141W WITH A SHORTWAVE RIDGE EXTENDING NE TO A CREST AT 32N128W...AND A RIDGE EXTENDING E ACROSS THE TROPICS TO A CREST AT 12N118W. AN UPPER TROUGH IS CENTERED NW OF THE AREA FROM 32N147W TO OVER THE HAWAIIAN ISLANDS AND IS SWINGING EASTWARD TOWARDS THE NW PORTION. A BAND OF UPPER MOISTURE...ORIGINATING IN THE CENTRAL PACIFIC...IS STREAMING E IN UPPER ZONAL FLOW BETWEEN THE TROPICAL ANTICYCLONE AND THIS APPROACHING UPPER TROUGH...ACROSS THE AREA WITHIN 270 NM EITHER SIDE OF A LINE FROM 210N140W TO 25N124W...WHERE IT ENCOUNTERS THE DRY AIR ACCOMPANYING AN UPPER TROUGH PREVIOUSLY DESCRIBED. AN UPPER RIDGE EXTENDS SW FROM THE CARIBBEAN UPPER ANTICYCLONE PREVIOUSLY MENTIONED AT 20N87W TO A SHARP CREST OVER THE DEEP TROPICS AT 11N113W. AN AREA OF UPPER DIFFLUENCE IS INDUCED W OF THE RIDGE CREST...AND IS ENHANCING THE CONVECTION PREVIOUSLY DESCRIBED ALONG A SURFACE TROUGH EXTENDING N FROM THE MONSOON TROUGH TO 17N117W. MOST OF THE RESULTANT DEBRIS MOISTURE IS ADVECTED NE ALONG THE W PERIPHERY OF THE UPPER RIDGE...AND MERGES WITH ADDITIONAL UPPER MOISTURE...ORIGINATING FROM CONVECTION OVER CENTRAL AMERICA...WITH THE MOISTURE SPREADING N ACROSS THE WESTERN GULF OF MEXICO. AN UPPER CYCLONE IS SHIFTING W ACROSS THE SW CARIBBEAN NEAR 12N81W...AND ERODING THE UPPER RIDGE OVER CENTRAL AMERICA. UPPER DIFFLUENCE WELL W OF THIS UPPER CYCLONE AND UNDER THE UPPER RIDGE...ENHANCED CONSIDERABLE CONVECTION OVER NORTHERN COSTA RICA...WESTERN NICARAGUA... WESTERN HONDURAS AND SE GUATEMALA ON SAT. THIS CONVECTION HAS MOVED W OVER THE PACIFIC WATERS ALONG CENTRAL AMERICA AS PREVIOUSLY DESCRIBED. THIS DAILY CONVECTION CONTINUES TO MOISTEN THE UPPER LEVELS OVER CENTRAL AMERICA TO INCLUDE SOUTHEASTERN MEXICO...AND WILL LIKELY SUPPORT INTERIOR CONVECTION OVER THE WESTERN PORTIONS OF CENTRAL AMERICA AT PEAK HEATING AGAIN THIS AFTERNOON. GULF OF CALIFORNIA...NW WINDS AT 10-15 KT ARE EXPECTED ACROSS THE GULF WATERS THROUGH EARLY TONIGHT...THEN INCREASE 15-20 KT TONIGHT ACROSS THE GULF WATERS TO THE S OF 28N...WITH SEAS OF 3- 5 FT IN LONG FETCH CENTRAL WATERS BRIEFLY TUE EVENING. LITTLE CHANGE THEN EXPECTED THROUGH TUE AFTERNOON. GUIDANCE THEN SUGGESTS THE GRADIENT WILL RELAX SUPPORTING NW 10-15 KT THROUGH FRI MORNING. SURFACE WINDS WILL BACK TO THE SW AND INCREASE TO 15-20 KT OVER THE NORTHERN GULF WATERS ON FRI AFTERNOON IN ADVANCE OF AN APPROACHING COLD FRONT. GULF OF PAPAGAYO...NE WINDS AT EXPECTED TO SURGE INTO THE GULF OF PAPAGAYO AT 20-25 KT ON MON NIGHT WITH SEAS BUILDING BRIEFLY TO 4 TO 6 FT DOWNSTREAM OF THE GULF...WITH THE MAXIMUM SEAS NEAR 11N87W. BAJA CALIFORNIA PENINSULA...LIGHT NW-N 5-10 KT WINDS WITH SEAS 2-4 FT IN MIXED NW AND LONG PERIOD S SWELL...WILL CONTINUE ALONG THE PACIFIC COAST OF THE BAJA PENINSULA THIS MORNING. THE GRADIENT WILL TIGHTEN THIS EVENING SUPPORTING NW 10-15 KT/SEAS 3- 5 FT THROUGH TUE NIGHT. LATEST GUIDANCE HAS REVERSED...AND NOW RELAXES THE GRADIENT SUPPORTING ONLY 5-10 KT THROUGH EARLY FRI. NW WINDS ARE EXPECTED TO INCREASE TO 15-20 KT ACROSS THE COASTAL WATERS N OF 28N LATE FRI...AND FURTHER INCREASE TO 20-25 KT FRI NIGHT WITH SEAS BUILDING 7-10 FT. ELSEWHERE AT THE SURFACE...A COLD FRONT IS APPROACHING THE FAR NW WATERS WITH S-SW WINDS AT 15-20 KT ACROSS THE DISCUSSION AREA NW OF A LINE FROM 32N129W TO 24N140W. COMBINED SEAS ARE AT 6-8 FT IN MIXED NW AND LONG PERIOD SE CROSS-EQUATORIAL SWELL. THE FRONT WILL EXTEND FROM 32N135W TO 26N140W LATE TONIGHT WITH THE SOUTHERLY FLOW N OF 27N WITHIN 180 NM E OF FRONT INCREASING TO 20-25 KT...AND THE NW FLOW WILL INCREASE TO 20-25 KT N OF 29N WITHIN 120 NM W OF FRONT. SEAS WILL BUILD BRIEFLY TO 8-11 FT WITHIN THESE AREAS. A SURFACE RIDGE WILL STRENGTHEN E OF THE APPROACHING FRONT BY TUE AND BLOCK THE FORWARD ADVANCE OF THE FRONT...WHICH WILL WASH OUT FROM 32N128W TO 25N135W ON TUE. $$ NELSON