000 AXPZ20 KNHC 162110 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC MON MAR 16 2015 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 2000 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...THE GRADIENT BETWEEN 1026 MB HIGH PRES OVER NE MEXICO AND THE MONSOON TROUGH TO THE S IS STRONG ENOUGH TO SUPPORT MINIMAL GALE FORCE N WINDS IN THE GULF OF TEHUANTEPEC THIS AFTERNOON WITH SEAS TO 11 FT. HIGH PRES OVER NE MEXICO WILL GRADUALLY WEAKEN OVER THE NEXT DAY OR SO...DIMINISHING THE PRES GRADIENT AND THE WINDS IN THE GULF OF TEHUANTEPEC. NUMERICAL GUIDANCE IS NOW UNANIMOUS THAT WINDS WILL REMAIN BELOW GALE FORCE OVERNIGHT TONIGHT. DRAINAGE FLOW OFF THE MOUNTAINOUS TERRAIN WILL HELP MAINTAIN 30 KT N WINDS THROUGH SUNRISE TUE. WINDS SHOULD DIP BELOW THE ADVISORY CRITERIA OF 20- 25 KT BY TUE EVENING...WITH SEAS FINALLY SUBSIDING BELOW 8 FT OVERNIGHT TUE NIGHT. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 08N83W TO LOW PRES NEAR 05N91W 1010 MB TO 04N104W TO 11N117W TO LOW PRES NEAR 10N122W TO 06N132W. THE ITCZ AXIS WAS ANALYZED FROM 06N132W TO 06N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 240 NM SE OF THE AXIS BETWEEN 83W AND 85W...WITHIN 270 NM N AND 120 NM S OF THE AXIS BETWEEN 90W AND 94W...AND S OF THE AXIS TO 07N BETWEEN 106W AND 125W. ...DISCUSSION... A WEAKENING UPPER LEVEL TROUGH IS CHARGING EASTWARD THROUGH NW WATERS. A SOUTHWESTERLY JET ON THE LEADING EDGE OF THIS UPPER TROUGH IS PROPELLING MOISTURE ALOFT INTO THE FORECAST AREA. SATELLITE IMAGERY SHOWS AN AREA OF MULTI-LAYERED CLOUDS WITH SOME EMBEDDED SHOWERS WITHIN 570 NM E OF A LINE FROM 32N130W TO 10N137W. A DISSIPATING STATIONARY FRONT AT THE SURFACE STRETCHES FROM 32N130W TO 22N138W. THIS REMNANT BOUNDARY HAD EARLIER CONTRIBUTED TO THE BATCH OF NW SWELL THAT STILL MAINTAINS AN AREA OF 8 TO 10 FT SEAS S OF 11N W OF 133W. THIS DAMPENING SWELL SHOULD SEE SEAS SUBSIDE BELOW 8 FT OVERNIGHT TONIGHT. THE UPPER TROUGH WILL PUSH INTO NE WATERS TUE AND RECEIVE REINFORCING SHORTWAVE ENERGY IN ITS BACK EDGE BY WED WHICH WILL DEEPEN AND SLOW THE TROUGH ALOFT. THE 1021 MB HIGH PRESSURE CENTER NEAR 31N138W EXTENDS A RIDGE AXIS NE THROUGH 32N137W AND SW THROUGH 30N140W. THE HIGH SHOULD STRENGTHEN AND IT MOVES NE TO 35N132W BY TUE AFTERNOON WHERE IT WILL REMAIN THROUGH WED AFTERNOON AS IT CONTINUES TO STRENGTHEN. THE STRENGTHENING SUBTROPICAL HIGH WILL TRIGGER A RETURN OF MODERATE TO FRESH TRADE WINDS OVER WATERS W OF 120W BY THE END OF THE FORECAST PERIOD WED AFTERNOON. AN UPPER LOW IS CENTERED NEAR THE SOUTHERN GULF OF CALIFORNIA. PACIFIC MOISTURE IS FEEDING INTO THE LEADING EDGE OF THIS TROUGH WHERE POSITIVE VERTICAL MOTION IN THE REAR RIGHT QUADRANT OF THE UPPER JET ON THE EASTERN SIDE OF THE LOW IS ENHANCING CONVECTION. SCATTERED MODERATE CONVECTION WAS N OF 16N WITHIN 210 NM E OF A SURFACE TROUGH REFLECTED BY THIS UPPER LOW FROM 22N106W TO 13N108W AND SCATTERED SHOWERS ARE FOUND N OF THIS AREA OVER MUCH OF CENTRAL MEXICO BETWEEN 100W AND 107W. THERE ARE ALSO ISOLATED THUNDERSTORMS NEAR THE UPPER LOW CENTER IN THE VICINITY OF THE SOUTHERN TIP OF THE BAJA CALIFORNIA PENINSULA ACCORDING TO LIGHTNING STRIKE DATA. THE UPPER LOW WILL TURN NEGATIVE TILT TONIGHT AND SHIFT NE INTO NORTHWESTERN MEXICO BEFORE PUSHING INTO TEXAS WED. THE PLUME OF LOW-LEVEL MOISTURE DIRECTED INTO MEXICO WILL WANE THROUGH TUE...WITH THE BULK OF THE PRECIPITATION MOVING N OUT OF MEXICO BY WED MORNING. GAP WINDS... GULF OF PAPAGAYO...HIGH PRES OVER THE GULF OF MEXICO WILL REMAIN STATIONARY BUT GRADUALLY WEAKEN THROUGH WED AFTERNOON. THE PRES GRADIENT BETWEEN THIS RIDGING TO THE N AND THE MONSOON TROUGH TO THE S WILL BE ENHANCED BY NOCTURNAL DRAINAGE FLOW TO ALLOW FRESH TO STRONG E-NE WINDS IN THE GULF OF PAPAGAYO DURING THE OVERNIGHT AND EARLY MORNING HOURS THROUGH WED AFTERNOON. $$ SCHAUER