000 AXPZ20 KNHC 201018 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC WED JAN 20 2010 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 0915 UTC. ...ITCZ... AXIS ANALYZED ALONG 02N79W TO 05N85W TO 06N91W TO 04N100W TO 08N119W TO 08N129W TO 06N140W. ISOLATED TO SCATTERED MODERATE TO STRONG CONVECTION WAS OCCURRING WITHIN 90 NM OF AXIS W OF 106W. ...DISCUSSION... BROAD UPPER RIDGE ACROSS CENTRAL PACIFIC S THROUGH W OF THE HAWAIIAN ISLANDS EXTENDS E ALONG 16N TO 130W...WHILE A LARGE POLAR LOW SE OF THE ALEUTIANS CONTINUES TO PRODUCE AN UNUSUALLY STRONG AND BROAD W TO WNW JET FROM THE CENTRAL PACIFIC ESE TO OFFSHORE OF THE CALIFORNIA COAST NEAR 130W. CORE WIND SPEEDS IN THE UPPER JET WERE IN EXCESS OF 150 KT N OF 30N PER RECENT STLT DERIVED WINDS...WHILE A BRANCH OF 90-140 KT WNW WINDS WERE DETECTED FROM 25N TO 30N MOVING INTO BAJA CALIFORNIA. A BROAD LONG WAVE TROUGH ACROSS THE GULF OF MEXICO EXTENDED FROM THE YUCATAN SW TO NEAR 9N109W...THEN CONTINUED IN A NARROW TUTT LIKE FASHION WSW...CROSSING THE EQUATOR NEAR 140W. WEAK CYCLONIC TURNING AND UPPER DIVERGENCE ACROSS THE ITCZ WAS YIELDING ISOLATED TO SCATTERED MODERATE TO STRONG CONVECTION ALONG THE ITCZ AS DESCRIBED ABOVE. A SERIES OF SHORT WAVES HAVE BEEN MOVING EWD ACROSS THE CENTRAL AND NE PACIFIC...EMBEDDED IN THIS STRONG WLY FLOW ALOFT...AND HAVE BECOME INCREASINGLY NEGATIVELY TILTED IN TIME AS THEY APPROACHED THE W COAST OF THE U.S. DUE TO THE PERSISTENT POLAR VORTEX SE OF THE ALEUTIANS. THIS HAS ALLOWED FOR THIS STRONG UPPER FLOW INTO THE BAJA. THE ERN MOST S/W IN THE AREA HAS MOVE INLAND ACROSS SRN CALIFORNIA IN THE PAST 24 HOURS...WHERE SEVERE WX WAS INDICATED...AND CURRENTLY SUPPORTS A COLD FRONT ACROSS THE NRN GULF OF CALIFORNIA SW INTO NE PORTIONS NEAR 24N125W. 20-25 KT SWLY WINDS WERE OCCURRING ALONG AND AHEAD OF THIS FRONT AND INTO THE GULF OF CALIFORNIA. THE NEXT S/W TO THE W HAS CROSSED 130W N OF 30N AND WAS SUPPORTING ANOTHER FRONT MOVING INTO THE NW PORTIONS OF THE AREA. GALES TO 40 KT WERE OCCURRING BEHIND THIS FRONT ACROSS THE FORECAST AREA...WITH SEAS TO 27 FT IN LARGE NW SWELL. THIS STRONG UPPER FLOW WILL PERSIST FOR ANOTHER 48 HOURS AND ALLOW YET ANOTHER S/W TO MOVE ESE TO OFFSHORE OF CALIFORNIA AND CARVE OUT A CUT OFF UPPER LOW...AND YIELD A PROGRESSION OF COLD FRONTS MOVING ESE TO SE INTO THE AREA...EVENTUALLY MOVING SE ACROSS ALL OF BAJA CALIFORNIA BY FRI EVENING...AND ACROSS OLD MEXICO THIS WEEKEND...INTO THE GULF OF MEXICO...AND REACH FROM THE SW GULF ACROSS SRN MEXICO...TO NEAR 11N120W BY SUNDAY EVENING. STRONG GALES...AND POTENTIALLY STORM FORCE WINDS WILL SWEEP ACROSS N PORTIONS OF THE AREA N OF 26N DURING THE NEXT 12 TO 48 HOURS AND GENERATE HUGE SEAS IN NW SWELL THAT WILL PROPAGATE THROUGH THE ENTIRE AREA AND SLAM THE W COAST OF S AMERICA WITH HUGE SURF SUN AND MON. SEAS ACROSS THE FORECAST AREA WILL BUILD 15 TO 30+ FT IN LARGE NW SWELL BY THU EVENING...FROM THE SRN TIP OF BAJA SW AND W INTO THE TROPICS. ELSEWHERE AT THE SURFACE... HIGH PRES CENTER 1015 MB AT 23N116W IS BEING NUDGED E BY THE APPROACHING COLD FRONTS. THE PRESSURE GRADIENT TO THE S OF THIS WEAK SURFACE RIDGE IS PRODUCING 20+ KT TRADES S OF 15N AND W OF 130W...AND WILL GRADUALLY SHIFT W AND WEAKEN NEXT FEW DAYS. 20-25 KT NE TO E WINDS WILL CONTINUE THROUGH GULF OF PAPAGAYO AND EXPECTED TO DIMINISH TO OR BELOW 20 KT BY FRI. MODERATE TO STRONG NLY WIND ACROSS GULF OF PANAMA WILL DIMINISH BELOW 20 KT THU MORNING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ STRIPLING