000 AXPZ20 KNHC 301605 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC MON JUL 30 2012 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 1500 UTC. ...TROPICAL WAVES... SATELLITE IMAGERY AND OVERNIGHT SCATTEROMETER PASSES SUGGEST A TROPICAL WAVE ALONG 101W...EXTENDING FROM THE MONSOON TROUGH N TO 16N MOVING W 10 KT. THIS WAVE HAS GROWN BAROTROPICALLY OVER THE PAST SEVERAL DAYS...AND AMPLIFIED SIGNIFICANTLY IN THE PAST 24 HOURS...FUELED BY ENERGY PROVIDED BY A PERSISTENT LOWER TROPOSPHERIC JET ALONG 12N EXTENDING FROM THE SW CARIB ACROSS CENTRAL AMERICA...AND ASSOCIATED GAP WIND FLOW THROUGH AND DOWNSTREAM OF THE GULF OF PAPAGAYO...AND MOST RECENTLY...WITH ADDITIONAL ENERGY AND CONVERGENCE FROM A SMALL PLUME OF NE WINDS DOWNSTREAM FROM THE GULF OF TEHUANTEPEC. THIS WAVE IS EXPECTED TO CONTINUE TO MOVE SLOWLY W AND REMAIN CONVECTIVELY ACTIVE FOR THE NEXT TWO DAYS BEFORE WEAKENING AND LOSING AMPLITUDE AS IT MOVES W OF 115W WED NIGHT. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH EXTENDS FROM 09N74W AND MEANDERS W-SW TO 06N110W...WHERE IT TRANSITIONS TO ITCZ...CONTINUING ON TO 08.5N119W TO BEYOND 08N140W. SCATTERED TO NUMEROUS MODERATE TO STRONG CONVECTION NOTED N OF 03.5N E OF 83W. NUMEROUS STRONG CONVECTION NOTED FROM 04N TO 08N E OF 81W. SCATTERED MODERATE ISOLATED STRONG CONVECTION OCCURRING IN NARROW BANDS FROM 08N TO 15N BETWEEN 98W AND 106W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 240 NM N AND 270 NM S OF ITCZ AXIS W OF 110W. ...DISCUSSION... A LARGE BLOCKING MIDDLE TO UPPER LEVEL RIDGE OVER THE CENTRAL U.S. ALONG ABOUT 100W CONTINUES TO PRODUCE A STAGNANT UPPER PATTERN ACROSS MUCH OF THE DISCUSSION AREA. A MIDDLE TO UPPER LEVEL CYCLONE NEAR 23N125W REMAINS NEARLY STATIONARY...WITH A TROUGH EXTENDING NE TO THE SOUTHERN CALIFORNIA COAST...AND ALSO SW TO NEAR 15N133W. A COMPLEX TUTT EXTENDS FROM THE GULF OF MEXICO W AND NW ACROSS MUCH OF MEXICO...WITH SEVERAL TUTT LOWS OF DIFFERING SIZES. AMPLE LOW TO MID LEVEL MOISTURE AND TUTT ASSOCIATED UPPER DIVERGENCE WILL MAINTAIN ACTIVE WEATHER ACROSS MEXICO ALONG THE SIERRA MADRE OCCIDENTALES AND EXTENDING W AND NW ACROSS THE GULF OF CALIFORNIA. UPPER LEVEL EASTERLIES ARE FOUND S OF 16N AND W OF 80W...YIELDING LIGHT WIND SHEAR AND FAVORABLE UPPER CONDITIONS FOR PERIODS OF DEEP CONVECTION. AT LOWER LEVELS...SURFACE HIGH PRES REMAINS CENTERED NW OF THE AREA NEAR 35N136W WITH A RIDGE EXTENDING SE FROM THE HIGH TO 20N114W. THE RESULTING PRES GRADIENT BETWEEN THIS RIDGE AND LOWER PRES NEAR THE ITCZ IS PRODUCING A ZONE OF 20-25 KT NE-E TRADES FROM 11N TO 20N W OF 130W WITH SEAS TO 9 FT. THESE CONDITIONS WILL NOT CHANGE MUCH IN AREAL COVERAGE AND INTENSITY THROUGH THE NEXT 24-48 HOURS. NE TO E WINDS OF 20-25 KT WILL CONTINUE TO PULSE ACROSS AND DOWNWIND OF THE GULF OF PAPAGAYO THROUGH EARLY WED...BEFORE DIMINISHING BY WED EVENING. A SUFFICIENT PRES GRADIENT EXISTS BETWEEN HIGH PRES ACROSS THE GULF OF MEXICO AND THE MONSOON TROUGH S-SW OF CENTRAL AMERICA RESULTING IN N-NE 20-25 KT WINDS THROUGH THE GULF OF TEHUANTEPEC AND DOWNSTREAM/SW ABOUT 150 NM. THE TROPICAL WAVE MENTIONED ABOVE WITH HELP TO MAINTAIN THIS FLOW THROUGH WED MORNING...WITH WINDS DECREASING TO 20 KT OR LESS WED AFTERNOON. A LOW TO MIDDLE LEVEL CYCLONIC CIRCULATION NEAR 18N113W CONTINUES TO INDUCE PULSING CONVECTION IN ITS VICINITY AS IT DRIFTS W...AND WAS DEPICTED AS A SURFACE TROUGH ALONG 113W BY AN OVERNIGHT ASCAT PASS. THIS TROUGH WILL CONTINUE TO DRIFT W AND WEAKEN THROUGH THE NEXT 48 HOURS AS IT ENCOUNTERS GRADUALLY COOLER OCEAN WATERS AND MORE STABLE ATMOSPHERIC CONDITIONS. CROSS-EQUATORIAL SOUTHERLY SWELL WILL BREACH THE S CENTRAL/SW BORDER OF THE DISCUSSION AREA BY TUE AFTERNOON WITH 8 FT SEAS EXPECTED S OF 04N BETWEEN 110W AND 125W IN SW SWELL. $$ STRIPLING