000 AXPZ20 KNHC 020248 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC MON JUL 02 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 0030 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS IS INLAND OVER PANAMA AND COSTA RICA. THE ITCZ AXIS EXTENDS FROM 10N111W TO 11N121W TO 06N132W TO 06N140W. ISOLATED MODERATE CONVECTION IS WITHIN 180 NM EITHER SIDE OF THE AXIS BETWEEN 113W AND 129W AND WITHIN 120 NM N OF THE AXIS W OF 131W. A TROUGH LIES E OF THE ITCZ ALONG 109W FROM 09N TO 15N. SCATTERED MODERATE CONVECTION IS S OF THE TROUGH FROM 04N TO 09N BETWEEN 103W AND 111W. ...TROPICAL WAVE... A TROPICAL WAVE IS ALONG 98W FROM 08N TO 14N. IT IS MOVING W AT 5 KT. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 240 NM E OF THE WAVE FROM 08N TO 13N AND SCATTERED MODERATE CONVECTION IS ELSEWHERE WITHIN 510 NM E AND 120 NM W OF THE WAVE FROM 08N TO 13N AS WELL AS FROM 04N TO 08N BETWEEN 90W AND 101W. THIS WAVE LIES ON THE WEST EDGE OF A DEEP LAYER INVERTED TROUGH THAT IS SUPPORTING AN UPPER LOW EVIDENT IN WATER VAPOR IMAGERY NEAR THE GULF OF TEHUANTEPEC. SOME OF THE FORECAST MODELS ARE SHOWING CONSOLIDATION OF THE MID LEVEL ENERGY ASSOCIATED WITH THE TROPICAL WAVE AND THE INVERTED TROUGH AND ALLOW THE DEVELOPMENT OF A SURFACE LOW ALONG THE WAVE. THERE IS SOME EVIDENCE IN THE 1550 UTC ASCAT AND 1808 UTC OSCAT IMAGERY THAT A BROAD LOW IS TRYING TO FORM ALONG THE WAVE AROUND 10N. SHEAR SHOULD DETER ANY SIGNIFICANT DEEPENING OF THIS LOW THROUGH THE END OF THE FORECAST PERIOD TUE EVENING. ...DISCUSSION... SUBTROPICAL RIDGING REMAINS WEAK OVER THE FORECAST AREA. IT STEMS FROM A 1029 MB HIGH PRES SYSTEM NEAR 38N155W. THE RIDGING OVER THE WESTERN PORTION OF THE FORECAST AREA REMAINS COMPROMISED BY AN UPPER TROUGH THAT EXTENDS FROM THE PACIFIC NW U.S. INTO NW FORECAST WATERS. TRADE WINDS ARE DOWN TO A MODERATE BREEZE AT THE MOMENT AND WILL HOVER NEAR 20 KT OVER FAR W WATERS JUST N OF THE ITCZ THROUGH TUE EVENING. THE DEEP LAYER TROUGHING MOVING INTO THE WESTERN U.S. IS DECREASING SURFACE PRESSURES THERE AS HIGH PRES BUILDS BEHIND THE FRONT. THIS HAS RESULTED IN A TIGHT PRES GRADIENT THAT EXTENDS SOUTHWARD TO OFF BAJA CALIFORNIA. FRESH TO STRONG NW WINDS CAN BE FOUND AS FAR S AS 25N AND W OF THE PENINSULA TO 119W. ON MON...THE STRONGEST PRES GRADIENT WILL SHIFT NORTHEASTWARD AND WINDS AND SEAS WILL BEGIN DIMINISHING OFF THE W COAST OF BAJA CALIFORNIA. DEEP LAYERED INVERTED TROUGHING BETWEEN 105W AND 115W IS FORCING A SURFACE TROUGH N OF THE ITCZ ALONG 109W. CONVECTION FOUND PRIMARILY S OF THE TROUGH IS DESCRIBED IN THE ITCZ/MONSOON TROUGH SECTION ABOVE. PRECIPITABLE WATER IMAGERY SHOWS A MOISTURE MAXIMA NEAR 06N106W. CONVECTION HERE IS BEING ENHANCED BY LIFT OF THIS MOISTURE BY UPPER DIFFLUENCE BETWEEN SE FLOW N OF 06N AND N FLOW S OF 06N. THE TROUGH IS EXPECTED TO WEAKEN OVER THE NEXT TWO DAYS AND A DRIER AIR MASS IS FORECAST TO MOVE IN FROM THE NORTH. THIS SHOULD DECREASE THE CHANCE FOR CONVECTION. GAP WINDS... GULF OF PAPAGAYO...THE GRADIENT BETWEEN HIGH PRES IN THE GULF OF MEXICO AND LOWER PRES TO THE SW WILL REMAIN STRONG ENOUGH THROUGH TUE EVENING FOR A SUSTAINED FRESH BREEZE IN THE GULF OF PAPAGAYO THAT IS EXPECTED TO BE STRONGER IN THE EARLY MORNING HOURS WITH THE ASSISTANCE OF DRAINAGE FLOW OFF THE LAND. GULF OF CALIFORNIA...THE 1728 UTC ASCAT PASS AND THE 1942 UTC OSCAT PASS SHOW FRESH S-SE WINDS LIE OVER THE GULF OF CALIFORNIA S OF 29N. THESE WINDS ARE INDUCED BY THE INCREASING PRES GRADIENT BETWEEN THE SUBTROPICAL RIDGING OVER NE WATERS AND LOWER PRESSURES OVER CENTRAL MEXICO. FRESH WINDS WILL GRADUALLY SHRINK TO N OF 30N BY THE END OF THE FORECAST PERIOD TUE EVENING. $$ SCHAUER