000 AXPZ20 KNHC 302112 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SAT JUN 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1930 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 09N78W TO 09N91W TO A TROPICAL WAVE ALONG 93W FROM 07N TO 12N. THE ITCZ AXIS EXTENDS FROM 08N97W TO 08N103W TO 05N112W TO BEYOND 05N140W. RECENT SCATTEROMETER PASSES SHOW THE LOW PREVIOUSLY ANALYZED SW OF COSTA RICA HAS DISSIPATED FOR THE TIME BEING. SCATTERED MODERATE CONVECTION LIES WITHIN 360 NM NW OF THE TROPICAL WAVE N OF 09N AND WITHIN 360 NM SE OF THE TROPICAL WAVE N OF 09N...INCLUDING THE REMAINS OF THE LOW PRES SYSTEM. SCATTERED MODERATE CONVECTION CAN BE FOUND WITHIN 240 NM S OF THE AXIS E OF 80W INCLUDING IN THE GULF OF PANAMA. SCATTERED MODERATE CONVECTION ALSO IS WITHIN 180 NM S OF THE AXIS BETWEEN 105W AND 116W AND BETWEEN 120 NM AND 480 NM N OF AXIS BETWEEN 105W AND 110W. ...DISCUSSION... THE TROPICAL WAVE ALONG 93W MENTIONED IN THE SECTION ABOVE LIES ON THE WEST EDGE OF A DEEP LAYER INVERTED TROUGH THAT IS SUPPORTING AN UPPER LOW EVIDENT IN WATER VAPOR IMAGERY OVER BELIZE. SOME OF THE FORECAST MODELS ARE SHOWING CONSOLIDATION OF THE MID LEVEL ENERGY ASSOCIATED WITH THE TROPICAL WAVE AND THE INVERTED TROUGH OVER THE NEXT FEW DAYS WITH SOME INTENSIFICATION OF THE SURFACE REFLECTION EXPECTED EARLY NEXT WEEK. FOR NOW...FRESH TO STRONG LOW-LEVEL EASTERLY FLOW BEHIND THE TROPICAL WAVE CONTINUES TO FUNNEL THROUGH THE GULF OF PAPAGAYO. THE INCREASED LOW LEVEL VORTICITY INDUCED BY THIS JET WILL ALSO ASSIST IN THE DEVELOPMENT OF A LOW PRES SYSTEM AT THE SURFACE. CONVECTION ASSOCIATED WITH THE WAVE IS DESCRIBED IN THE SECTION ABOVE. A BROAD UPPER LOW IS CENTERED NEAR 03N107W. SPEED DIFFLUENCE BETWEEN THE 40 KT EASTERLY UPPER JET N OF THE LOW ALONG 12N AND LIGHTER NE FLOW NW OF THE LOW IS ENHANCING CONVECTION ALONG THE ITCZ. THIS CONVECTION IS ALSO DESCRIBED ABOVE. THE UPPER LOW IS FORECAST TO TRACK W-NW IN TANDEM WITH THE WEAKENING JET OVER THE NEXT DAY OR SO. THE SUBTROPICAL RIDGE IS RELATIVELY WEAK...STEMMING FROM 1033 MB HIGH PRES WELL NEAR 37N165W. THE RIDGING OVER THE WESTERN PORTION OF THE FORECAST AREA HAS BEEN COMPROMISED BY A DISSIPATING STATIONARY FRONT OVER NW WATERS. TRADE WINDS ARE DOWN TO A MODERATE BREEZE AS A RESULT. THE LOW PRES SYSTEM ANCHORING THIS FRONT WILL MOVE INTO NORTHERN CALIFORNIA OVERNIGHT TONIGHT...DECREASING SURFACE PRESSURES IN THE WESTERN U.S. WHILE HIGH PRES BUILDS ALONG 37N BEHIND THE FRONT. THIS WILL RESULT IN A TIGHTER PRES GRADIENT OFF BAJA CALIFORNIA. NW WINDS ARE ARE ALREADY A FRESH BREEZE OFF BAJA CALIFORNIA N OF 28N AS 1022 MB HIGH PRES E OF THE FRONT HAS BEEN FORCED CLOSER TO THE LOWER PRESSURES OVER NW MEXICO. WINDS WILL BECOME FRESH TO STRONG ON SUN AND EXPAND SOUTHWARD ALONG THE PENINSULA AS THE PRES GRADIENT STRENGTHENS BETWEEN THE NORTHWARD DISPLACED SUBTROPICAL RIDGE AND TROUGHING OVER THE WESTERN U.S. AND MEXICO. BY MON...THE EASTERN EDGE OF THE RIDGE AXIS WILL DIP SOUTHWARD AND WINDS AND SEAS WILL BEGIN DIMINISHING OFF THE W COAST OF BAJA CALIFORNIA JUST AS SOUTHERLY FLOW INCREASES OVER THE GULF OF CALIFORNIA. GAP WINDS... GULF OF PAPAGAYO...THE FRESH TO STRONG NE WINDS CURRENTLY IN PLACE BEHIND THE TROPICAL WAVE WILL SHRINK EASTWARD BY SUN AS THE WAVE PULLS WESTWARD. THE PRES GRADIENT WILL REMAIN STRONG ENOUGH THROUGH MON FOR A SUSTAINED FRESH BREEZE IN THE GULF OF PAPAGAYO INCREASING IN THE MORNING HOURS WITH THE ASSISTANCE OF DRAINAGE FLOW OFF THE LAND. GULF OF CALIFORNIA...FRESH TO STRONG SOUTHERLY WINDS ARE FORECAST TO BEGIN OVER THE GULF OF CALIFORNIA N OF 26N MON AFTERNOON AS THE SUBTROPICAL RIDGE SINKS SOUTHWARD TOWARD NE WATERS...INCREASING THE PRES GRADIENT OVER THE GULF. $$ SCHAUER