000 AXPZ20 KNHC 191611 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC THU NOV 19 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1530 UTC. ...SPECIAL FEATURES... TROPICAL STORM RICK IS LOCATED NEAR 14.7N 105.8W...OR 300 NM SW OF MANZANILLO MEXICO...AT 1500 UTC MOVING N AT 6 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1002 MB. MAXIMUM SUSTAINED WIND SPEED 35 KT WITH GUSTS TO 45 KT. SCATTERED MODERATE TO STRONG CONVECTION IS OBSERVED WITHIN 180 NM ACROSS THE NW AND 60 NM SE SEMICIRCLES. THE LOW LEVEL CENTER REMAINS UNDERNEATH THE SE PORTION OF A LARGE CONVECTIVE CLUSTER THIS MORNING...AS SOUTHEASTERLY WIND SHEAR CONTINUES TO IMPACT THE STORM. GLOBAL MODELS SUGGEST THAT THIS WIND SHEAR WILL DIMINISH SLIGHTLY DURING THE NEXT 48 HOURS...AND ALLOW FOR RICK TOSTRENGTHEN MODESTLY AS IT DRIFTS NORTH TO NORTHWARD TODAY...THEN BEGINS TO MOVE AT A FASTER RATE TOWARD THE NW TONIGHT AND FRIDAY... THEN CONTINUING NW AND PASSING BETWEEN CLARION AND SOCORRA ISLANDS SATURDAY NIGHT AND EARLY SUNDAY. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. GALE WARNING FOR GULF OF TEHUANTEPEC...HIGH PRES WILL BUILD BEHIND A COLD FRONT IN THE WESTERN GULF OF MEXICO N OF THE AREA TODAY AND TONIGHT WHICH WILL INDUCE ANOTHER ROUND OF FRESH TO STRONG NORTHERLY WINDS IN THE GULF OF TEHUANTEPEC THIS AFTERNOON AND EVENING... INCREASING TO MINIMAL GALE FORCE TONIGHT...WHEN SEAS WILL BUILD TO 11 FT. WIND ARE THEN EXPECTED TO DIMINISH BELOW GALE FORCE LATER IN THE DAY ON FRIDAY...CONTINUING AROUND 30 KT THOUGH SATURDAY MORNING THEN DIMINISHING FURTHER TO 20-25 KT IN THE VICINITY OF THE GULF THROUGH SATURDAY AFTERNOON. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 10N84W TO 08.5N94W TO 11N100W...WHERE IT IS FRACTURED...THEN RESUMES FROM 11.5N108W TO LOW PRESNEAR 11N113.5W TO LOW PRES NEAR 09.5N127W TO 07.5N132W...WHEREIT TRANSITIONS TO ITCZ...CONTINUING ON BEYOND 08N140W. SCATTEREDMODERATE TO STRONG CONVECTION NOTED FROM 05N TO 11.5N BETWEEN80W AND 105W. SCATTERED MODERATE TO STRONG CONVECTION NOTEDWITHIN 180 NM N AND 150 NM S OF TROUGH AND LOWS BETWEEN 110W AND130W. ...DISCUSSION... N OF 15N E OF 120W...TROUGHING OVER NW MEXICO HAS WEAKENED OVERNIGHT AS HIGH PRES NORTHWEST OF THE AREA HAS SHIFTED EAST. THIS HAS ALLOWED THE TIGHT PRES GRADIENT THAT WAS PREVIOUSLY OVER THE REGION TO WEAKEN...AND IN TURN ALLOWED STRONG WINDS OVER THE GULF OF CALIFORNIA AND OFF THE WEST COAST OF THE BAJA CALIFORNIA PENINSULA TO DIMINISH VERY SLIGHTLY. AN ALTIMETER PASS FROM 02 UTC INDICATED SEAS TO NEAR 8 FT IN BOTH THE SOUTHERN GULF OF CALIFORNIA AND OFF BAJA CALIFORNIA SUR...BUT CONTINUED N-NW WINDS OF 20-25 THROUGH THEFULL LENGTH OF THE GULF WILL MAINTAIN WAVE HEIGHTS OF 6-8 FT THROUGH LATE THIS MORNING BEFORE WINDS AND SEAS BEGIN TO SLOWLY SUBSIDE LATE THIS MORNING THROUGH THE AFTERNOON. NW SWELL WITH WAVE HEIGHTS OF 8 TO 9 FT WILL PERSIST W OF 118W THROUGH THIS MORNING...THEN CONTRACT WESTWARD AS THE NW SWELL DECAYS. S OF 15N E OF 110W...DEEP LAYER DRY AIR IS IN PLACE ACROSS MUCH OF THE AREA N OF 10N INFLUENCED BY A BROAD UPPER ANTICYCLONE CENTERED OVER SOUTHERN MEXICO...KEEPING OVERNIGHT CONVECTION MINIMAL OFF THE CENTRAL AMERICAN COAST NORTH OF COSTA RICA. SCATTERED CONVECTION PERSISTS S OF THE MONSOON TROUGH ALONG ROUGHLY 10N HOWEVER DUE TO CONVERGENCE OF MODERATE SW FLOW IN THE LOWER LEVELS AND WEAK UPPER DIVERGENCE ON THE SOUTHERN PERIPHERY OF THE MID/UPPER RIDGE. NO MAJOR CHANGES ARE EXPECTED OVER THE NEXT 2 TO 3 DAYS. LOOKING AHEAD...THERE IS SOME DISAGREEMENT WITH GLOBAL MODEL GUIDANCE WITH REGARDS TO THE DEVELOPMENT OF LOW PRES ALONG THE MONSOON TROUGH EAST OF COSTA RICA BY SAT. THE GFS IS AN OUTLIER SHOWING VERY AGGRESSIVE DEVELOPMENT OF A LOW PRESSURE SYSTEM BETWEEN 90W AND 100W MONDAY THROUGH WEDNESDAY...AND HAS BEEN DISCOUNTED AT THE PRESENT TIME. ELSEWHERE...OVERNIGHT SCATTEROMETER DATA CONTINUED TO SHOW STRONG TRADE WINDS OVER MUCH OF THE AREA N OF 11N BETWEEN RIDGING ASSOCIATED WITH THE 1030 MB HIGH NEAR 35N135W AND LOWER PRES ALONG THE MONSOON TROUGH/ITCZ. VARIOUS ALTIMETER DATA CONTINUE TO SHOW SEAS AS HIGH AS 12 FT IN THE AREA OF THE STRONG TRADE WINDS... HELPED IN PART PRIMARILY BY LONG PERIOD NW SWELL PREVAILING ACROSS MUCH OF THE REGION. THIS IS PRODUCING AN UNUSUALLY LARGE AREA OF CONFUSED SEAS OF 8 FT AND GREATER...ROUGHLY N OF 05N. THE RIDGE WILL GRADUALLY WEAKEN THROUGH THE REMAINDER OF THE WEEK AND ALLOW THE TRADE WINDS TO DIMINISH ACCORDINGLY. WINDS AND SEAS WILL SUBSIDE...BUT REMAIN 8 FT OR GREATER ACROSS MUCH OF THE WEST AND SOUTHWEST PORTIONS OF THE AREA THROUGH LATE IN THE WEEK. $$ STRIPLING