000 AXPZ20 KNHC 290953 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC TUE APR 29 2014 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 0830 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR FROM 09N75W TO 09N85W TO 04N97W...WHERE IT TRANSITIONS TO ITCZ...CONTINUING ON TO 08N111W TO 02N130W TO BEYOND 03N140W. SCATTERED MODERATE TO STRONG CONVECTION NOTED WITHIN 90 NM S OF TROUGH BETWEEN 80W AND 85W. SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 180 NM S OF TROUGH BETWEEN 88W AND 97W. SCATTERED TO LOCALLY NUMEROUS MODERATE TO STRONG CONVECTION NOTED FROM 02N TO 11.5N BETWEEN 110W AND 126W. SCATTERED MODERATE CONVECTION NOTED WITHIN 210 NM N AND 90 NM S OF ITCZ BETWEEN 126W AND 137W. ...DISCUSSION... AN UPPER LEVEL REX BLOCKING PATTERN ACROSS THE AREA FOR THE PAST 48 HOURS WILL BEGIN TO WEAKEN AND SHIFT EASTWARD DURING THE NEXT 24 HOURS AS A LARGE AND BROAD DEEP LAYERED TROUGH EXTENDING FROM THE GULF OF ALASKA INTO THE NW HAWAIIAN ISLAND CHAIN EARLY THIS MORNING MOVES E TO 145W THIS AFTERNOON AND EVENING...AND THEN SWEEPS NE ACROSS NW PORTIONS WED AND THU. CURRENTLY E OF THIS FEATURE IS A LARGE HIGH AMPLITUDE UPPER RIDGE CENTERED ALONG 126W AND N OF 29N...AND HAS BEGUN TO SHIFT E OVERNIGHT. DUE S OF THE RIDGE...A MIDDLE TO UPPER LEVEL CYCLONE HAS REMAINED CUT OFF FROM THE MEAN UPPER FLOW...CENTERED NEAR 22N127W...WITH UPPER TROUGH AXIS EXTENDING S-SE TO NEAR 14N123W. THIS CYCLONE REMAINS FAIRLY VIGOROUS THIS MORNING...WITH JET ENERGY MOVING THROUGH THE BASE OF THE TROUGH. MID LEVEL LIFT INDUCED BY THE CYCLONE CONTINUES TO PRODUCE ELEVATED CONVECTION TO THE E AND SE OF THIS LOW...CURRENTLY FROM 16N TO 23N BETWEEN 114W AND 122W. UPPER DIFFLUENCE AT THE BASE OF THE TROUGH ALSO CONTINUES TO ENHANCE A LARGE AREA OF MODERATE TO DEEP CONVECTION N OF THE ITCZ DESCRIBED ABOVE BETWEEN 110W AND 126W. AS THE CENTRAL PACIFIC UPPER TROUGH SWEEPS E AND NE DURING THE NEXT FEW DAYS...THIS CYCLONE WILL BE NUDGED E-NE AND MOVE ACROSS THE SOUTHERN TIP OF BAJA CALIFORNIA LATE WED AND INTO W CENTRAL MEXICO THU. EXPECT UNSTABLE CONDITIONS TO PREVAIL WITHIN ABOUT 400 NM E AND SE OF THIS LOW AS IT SHIFTS INLAND THROUGH THU. GLOBAL MODELS SUGGEST VERY WET AND UNSTABLE CONDITIONS WILL PREVAIL ACROSS SE MEXICO...LARGE PORTIONS OF CENTRAL AMERICA...AND THE TROPICAL WATERS E OF 110W THU THROUGH FRI AS THIS LOW PRESSURE SYSTEM MOVES NE ACROSS MEXICO. AT THE SURFACE...A 1027 MB HIGH IS CENTERED AT 37N128W WITH A RIDGE EXTENDING SE TO NEAR 14N113W. S OF THE RIDGE...NE TO E TRADEWINDS ARE FOUND S OF 22N AND W OF 122W...AND ARE FUELING ACTIVE CONVECTION NEAR AND N OF THE ITCZ THERE. SEAS ACROSS THIS AREA WERE RUNNING 7-9 FT IN MIXED LONG PERIOD NW...NE AND S SWELL. THE PRESSURE GRADIENT BETWEEN THE HIGH AND LOW PRESSURE ACROSS MEXICO AND THE DESERT SW OF THE U.S. IS PRODUCING FRESH TO STRONG N-NW WINDS OFF OF THE COAST OF SOUTHERN CALIFORNIA AND NORTHERN BAJA CALIFORNIA...AND CONTINUES TO GENERATE MODERATE PERIOD NW SWELL. SEAS ACROSS THE REGION ARE 7-9 FT IN NW SWELL AND EXTEND S TO NEAR 20N ACROSS THE OUTER WATERS OUT TO BEYOND 120W. WINDS ALONG THE W COAST OF BAJA CALIFORNIA HAVE DIMINISHED TO 15-20 KT EARLY THIS MORNING. HOWEVER...STRONG HIGH PRESSURE ACROSS THE GREAT BASIN WILL BEGIN TO NOSE SOUTHWARD INTO SOUTHERN CALIFORNIA AND THE GULF OF CALIFORNIA THIS MORNING BRING COOL AIR...AND STRONG NLY WINDS INTO N PORTIONS OF THE GULF. WINDS ARE EXPECTED TO QUICKLY INCREASE TO 20-30 KT BY LATE AFTERNOON AND EVENING...N OF 26N...AND BUILD SEAS 7 TO 10 FT BY EARLY TONIGHT. SOME OF THIS STRONG NLY FLOW WILL SPILL ACROSS THE GAPS IN THE MOUNTAINS OF BAJA AND ACROSS THE OUTER WATERS OF THE PENINSULA THIS AFTERNOON THROUGH WEDNESDAY. THESE WINDS INSIDE OF THE GULF WILL SPREAD TO CENTRAL PORTIONS N OF 26N THIS EVENING AND CONTINUE THROUGH WED EVENING TO PRODUCE SEAS TO 8 FT S OF ISLA SAN ESTEBAN. STRONG NLY WINDS ARE EXPECTED TO RETREAT INTO N PORTIONS WED NIGHT THROUGH THU BUT WILL PERSIST AND MAINTAIN SEAS 6-9 FT ACROSS N PORTIONS THROUGH THU NIGHT BEFORE WINDS AND SEAS SUBSIDE. A COLD FRONT WILL ENTER THE NW PORTION ON WED ACCOMPANIED BY A SW-W-NW 15-20 KT WINDS ACROSS THE WATERS FROM 28-32N WITH SEAS OF 7-9 FT. THE FRONT WILL SLOW AND WASH OUT ALONG 32N132W TO 25N138W ON WED. GULF OF TEHUANTEPEC...HIGH PRESSURE BUILDING BEHIND A GULF OF MEXICO COLD FRONT WED AND THU WILL NOSE SOUTHWARD INTO THE REGION WED NIGHT AND EARLY THU AND LEAD TO STRONG NLY FLOW AROUND 20 KT EARLY THU MORNING INTO THE GULF OF TEHUANTEPEC THAT WILL PERSIST THROUGH SAT. NOCTURNAL DRAINAGE FLOW WILL ENHANCE THIS FLOW EACH NIGHT...WITH A MAX TO 30 KT EXPECTED FRI NIGHT AND TO 25 KT SAT NIGHT BEFORE DIMINISHING SUN. $$ STRIPLING