000 AXPZ20 KNHC 310325 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC TUE JUL 31 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0230 UTC. ...TROPICAL WAVES... TROPICAL WAVE FROM 15N102W TO 08N104W. THE WAVE HAS AMPLIFIED SIGNIFICANTLY IN THE PAST 24 HOURS...FUELED BY ENERGY PROVIDED BY A PERSISTENT LOWER TROPOSPHERIC JET ALONG 12N EXTENDING FROM THE SW CARIBBEAN TO ACROSS CENTRAL AMERICA...AND ASSOCIATED GAP WIND FLOW THROUGH AND DOWNSTREAM OF THE GULF OF PAPAGAYO...AND WITH ADDITIONAL ENERGY AND CONVERGENCE FROM A SMALL PLUME OF NE WINDS DOWNSTREAM FROM THE GULF OF TEHUANTEPEC. SCATTERED MODERATE CONVECTION IS N OF 13N WITHIN 150 NM E OF THE WAVE... AND ALSO FROM 12N TO 14N BETWEEN 104W AND 109W. THIS WAVE IS EXPECTED TO CONTINUE TO MOVE SLOWLY W WHILE REMAINING 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... THE MONSOON TROUGH IS ALONG 07N78W TO 09N83W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 10N88W TO 10N103W THEN RESUMES FROM 09N106W TO 07N120W TO 09N140W. SCATTERED MODERATE CONVECTION IS N OF 07N E OF 86W. SIMILAR CONVECTION IS WITHIN 120 NM S OF THE ITCZ BETWEEN 91W AND 93W...AND ALSO BETWEEN 100 AND 103W. ...DISCUSSION... A LARGE BLOCKING MIDDLE TO UPPER LEVEL RIDGE OVER THE CENTRAL U.S. ALONG ABOUT 98W CONTINUES TO PRODUCE A STAGNANT UPPER PATTERN ACROSS MUCH OF THE DISCUSSION AREA. A MIDDLE TO UPPER LEVEL CYCLONE NEAR 26N126W IS DRIFTING TO THE W...WITH AN ATTENDANT TROUGH EXTENDING NE TO ACROSS THE CENTRAL BAJA CALIFORNIA PENINSULA...AND ALSO SW TO NEAR 13N140W. A COMPLEX TUTT EXTENDS FROM THE GULF OF MEXICO W AND NW ACROSS MUCH OF MEXICO...WITH SEVERAL ASSOCIATED TUTT LOWS OF DIFFERING SIZES OVER THIS REGION. AMPLE LOW TO MID LEVEL MOISTURE AND TUTT ASSOCIATED UPPER DIVERGENCE WILL MAINTAIN ACTIVE WEATHER ACROSS MEXICO ALONG THE SIERRA MADRE OCCIDENTALS...AND EXTENDING W-NW ACROSS THE GULF OF CALIFORNIA. UPPER LEVEL EASTERLIES ARE FOUND ACROSS THE MAJORITY OF THE WATERS S OF 13N AND W OF 80W... YIELDING LIGHT WIND SHEAR AND FAVORABLE UPPER LEVEL CONDITIONS FOR PERIODS OF DEEP CONVECTION. AT LOWER LEVELS...1027 MB SURFACE HIGH PRES REMAINS CENTERED NW OF THE AREA NEAR 35N140W WITH A RIDGE EXTENDING SE FROM THE HIGH TO 21N113W. THE RESULTING PRES GRADIENT BETWEEN THIS RIDGE AND LOWER PRES NEAR THE ITCZ IS PRODUCING A ZONE OF 20-25 KT NE TRADES FROM 10N TO 20N W OF 133W...AS WELL AS 20 KT NE-E WINDS FROM 10N TO 16N BETWEEN 127W AND 133W AS MEASURED BY A RECENT ASCAT PASS. SEAS TO 9 FT ARE ALSO ACCOMPANYING THESE WINDS. 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 TUESDAY DIMINISHING TUE NIGHT...WITH THE STRONGEST WINDS OCCURRING DURING THE MORNING HOURS DURING PEAK DRAINAGE FLOW OFF OF THE NEARBY LANDMASS. A SUFFICIENT PRES GRADIENT EXISTS BETWEEN HIGH PRES ACROSS THE GULF OF MEXICO AND THE MONSOON TROUGH S-SW OF CENTRAL AMERICA TO RESULT IN N-NE 20-25 KT WINDS THROUGH THE GULF OF TEHUANTEPEC AND DOWNSTREAM ABOUT 75-90 NM...AS INDICATED BY AN EARLIER ASCAT PASS. THE TROPICAL WAVE MENTIONED ABOVE WILL HELP TO MAINTAIN THIS FLOW THROUGH TUE MORNING...WITH WINDS DECREASING TO 20 KT OR LESS BY TUE NIGHT AS THE WAVE MOVES FARTHER AWAY FROM THE REGION. CROSS-EQUATORIAL SOUTHERLY SWELL HAS BREACHED THE S CENTRAL/SW BORDER OF THE DISCUSSION AREA WITH 8-9 FT SEAS IN PLACE S OF 03N BETWEEN 115W AND 125W IN SW SWELL...REACHING TO S OF 05N BETWEEN 110W AND 130W BY WED AFTERNOON. $$ LEWITSKY