000 AXPZ20 KNHC 190959 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC WED JAN 19 2011 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0930 UTC. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE AXIS IS CENTERED ALONG 5N78W 5N90W 5N100W TO 1010 MB LOWS NEAR 10N116W AND 10N125W. IT THEN BEGINS AGAIN AT 8N129W AND CONTINUES TO 7N140W. NO SIGNIFICANT CONVECTION IS NOTED. ...DISCUSSION... AN UPPER LEVEL TROUGH EXTENDING FROM THE SW U.S SW TO INTO THE AREA AT 32N117W AND TO 23N123W IS PROGRESSING EWD WITH TIME. WATER VAPOR IMAGERY SHOWS MODERATE SUBSIDENCE AND RESULTANT DRY AIR NW OF THE TROUGH TO 128W...AND SE OF THE TROUGH FROM 19N TO 24N. A JET STREAM BRANCH DIVES SE INTO THE AREA THROUGH 32N133W TO 25N125W...THEN ROUNDS THE BASE OF THE TROUGH TO 26N119W AND TRACKS NEWD TO ACROSS NORTHERN AND CENTRAL BAJA CALIFORNIA. SCATTERED TO BROKEN HIGH CIRRUS CLOUDS WITHIN EITHER 60 NM EITHER SIDE OF THE JET ARE BEING CHANNELED TO ACROSS BAJA CALIFORNIA AND FAR NORTHERN MEXICO. TO THE W OF THE TROUGH...THE AREA REMAINS DOMINATED BY BROAD SCALE UPPER RIDGING RESPONDING TO DEEP LAYER TROUGHING ANCHORED W OF THE REGION ALONG 155W. WATER VAPOR IMAGERY SHOWS THAT THE RIDGING STRETCHES WELL TO THE N OF THE REGION. AN UPPER LEVEL TROUGH IS OVER THE FAR WESTERN PORTION STRETCHING FROM 17N138W SE TO 11N132W TO 9N127W TO NEAR 8N121W. DIFFLUENT FLOW ALOFT NOTED TO THE E OF THE TROUGH CONTINUES TO PROVIDE FOR A FAVORABLE UPPER LEVEL ENVIRONMENT FOR ISOLATED TO WIDELY SCATTERED SHOWERS AND TSTMS TO FORM ALONG THE ITCZ. MOIST SW UPPER LEVEL FLOW TO THE E OF THE TROUGH ABOVE THE ITCZ CONVECTION IS ADVECTING SCATTERED TO BROKEN CIRRUS CLOUDS NEWD TO 19N...AND EWD FROM THERE TO ACROSS CENTRAL MEXICO FROM 14N TO 19N. MODERATE TO STRONG SUBSIDENCE EVIDENT TO THE SE OF THIS MOISTURE PLUME IS SUPPRESSING AND DEEP CONVECTION FROM DEVELOPING WITH ONLY ISOLATED WEAK CONVECTION ALONG THE ITCZ E OF 89W. A MID/UPPER LEVEL RIDGE EXTENDS FROM ANTICYCLONE ANCHORED OVER NW VENEZUELA SW TO THE EQUATOR AT 92W. AT THE SURFACE...A 1030 MB HIGH CENTER LOCATED N OF THE AREA NEAR 37N136W EXTENDS A RIDGE SE THROUGH 32N121W TO NEAR 22N125W. A TIGHT PRES GRADIENT ON THE SOUTHERN PERIPHERY OF THE RIDGE DUE TO THE PRES DIFFERENCE BETWEEN IT AND LOWER PRESSURE ASSOCIATED WITH THE ITCZ AND WEAK 1010 MB LOWS STATED ABOVE UNDER ITCZ CONTINUES TO INDUCE NE TO E 20 KT TRADE WINDS OVER THE AREA BOUNDED FROM 14N TO 20N W OF 135W. THESE TRADES ARE FORECAST TO REMAIN STEADY STATE OVER THE NEXT 48 HOURS AS THE HIGH CENTER REMAINS NEARLY STATIONARY...PERHAPS DRIFT SOME TO THE SW. A TIGHT PRES GRADIENT OVER THE FAR NE PORTION OF THE AREA DUE TO THE PRES DIFFERENCE BETWEEN THE RIDGE AND THE CALIFORNIA COASTAL TROUGH IS ALLOWING FOR NE WINDS OF 20 KT TO EXIST N OF 27N BETWEEN 121W AND 132W...WITH WINDS TO 30 KT OCCURRING JUST TO THE N OF 32N. THESE WINDS ARE FORECAST TO INCREASE TO 20 TO 25 KT IN 24 HOURS WHILE GALE FORCE WINDS START UP JUST N OF 32N. HOWEVER...BY 36 HOURS THESE WINDS DIMINISH TO 20 KT AS THE GRADIENT SLACKENS SOME. SEAS OF 8 TO 12 FT WITHIN THIS AREA OF WINDS WILL POSSIBLY BUILD TO 10 TO 14 FT IN MIXED NW AND N SWELL BY 24 HOURS...THEN LOWER TO A MAX OF 10 OR 11 FT OVER THE WESTERN SECTION BY 48 HOURS. ELSEWHERE AT THE SURFACE...THE WEAK 1010 MB LOWS MENTIONED ABOVE WILL ONLY DRIFT W THROUGH THE NEXT 36 HOURS THEN MOST PROBABLY BECOME DIFFUSE IN 48 HOURS...OR SHORTLY THEREAFTER. WITH RESPECT TO OTHER MARINE ISSUES...THE LARGE LONG PERIOD NW SWELLS WITH PERIODS OF 15-17 SEC ADVERTISED THE PAST FEW DAYS TO MOVE INTO THE AREA ARE ALREADY PRODUCING SEAS OF 8 TO 12 FT IN THE WESTERN SECTION. THESE SWELLS...GENERATED FROM A SERIES OF INTENSE LOW PRES SYSTEMS WELL NW OF THE REGION...WILL CONTINUE THROUGH 48 HOURS AND FORECAST BY WAVEWATCH GUIDANCE TO BUILD EVEN FURTHER BEYOND 48 HOURS. GAP WINDS... NEXT GULF OF TEHUANTEPEC EVENT IS FORECAST TO BEGIN ON FRI AS HIGH PRES BUILDS S ACROSS MEXICO AND WESTERN GULF OF MEXICO IN THE WAKE OF A COLD FRONT THAT MOVES THROUGH THE BAY OF CAMPECHE AND SOUTHEASTERN MEXICO. PRESENT INDICATIONS ARE THAT N WINDS THROUGH ISTHMUS OF TEHUANTEPEC ARE EXPECTED TO INITIATE AT 20 TO 25 KT...THEN REACH TO 30 KT IN THE AFTERNOON WITH THE POSSIBILITY OF A BRIEF EPISODE OF WINDS REACHING MINIMAL GALE FORCE. WINDS ARE EXPECTED TO INCREASE TO 20 KT FROM THE NW OVER THE FAR NORTHERN WATERS OF THE GULF OF CALIFORNIA BEGINNING ON THU AS BROAD AND STRONG HIGH PRES SETTLES IN OVER THE INTERMOUNTAIN AREA OF THE U.S. AND INTERACTS WITH SURFACE TROUGHINESS OVER NW MEXICO AND THE NORTHERN GULF OF CALIFORNIA ALLOWING FOR THE CULPRIT STEEP PRES GRADIENT TO BECOME PRESENT. $$ AGUIRRE