000 AXPZ20 KNHC 080344 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SAT MAR 08 2008 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0345 UTC. ...ITCZ... ITCZ AXIS ALONG 1N79W 2N95W 7N110W 5N125W 7N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 120 NM N OF AXIS BETWEEN 115W AND 140W...AND WITHIN 45-60 NM OF LINE 11.5N109W 9.5N113W. SCATTERED MODERATE EQUATOR TO 5N BETWEEN 87W AND 94W. ...DISCUSSION... EAST OF 110W... MAIN FORECAST ISSUE IS THE CURRENT GALE FORCE WIND EVENT UNDERWAY WITHIN 60-90 NM OF THE GULF OF TEHUANTEPEC. A STRONG COLD FRONT HAS MOVED THROUGH THE CHIVELAS PASS/ISTHMUS OF TEHUANTEPEC AND ALONG WITH A 1022 MB SFC HIGH NEAR 22N97W HAS BROUGHT GALES TO THE AREA. SFC OBSERVATIONS FROM MINATITLAN SEVERAL HOURS AGO INDICATED SUSTAINED WINDS OF 40 WITH GUSTS TO 45 KNOTS. BASED ON THIS OBSERVATION...A STRONGER GALE WITH WINDS UP TO 45 KNOTS...AND AN OUTSIDE CHANCE FOR STORM FORCE WINDS IS FCST FOR THE HIGH SEAS WITHIN THE NEXT 12 HOURS. IN ANY EVENT THE SURFACE HIGH PRES DRIVING THE EVENT WILL SHIFT EWD BY LATER TODAY...ALLOWING THE PRES GRADIENT TO RELAX AND ALLOWING MODERATE SELY RETURN FLOW OVER THE WRN GULF OF MEXICO. THIS WILL ALLOW PERMIT NLY GAP WINDS THROUGH TEHUANTEPEC TO DIMINISH TO LESS THAN GALE FORCE BY EARLY SUN...AND LESS THAN 20 KNOTS BY SUN EVENING. ELSEWHERE E OF 110W...A TIGHT GRADIENT ON THE EASTERN SIDE OF THE HIGH PRES IS ALLOWING 20-25 KNOT NLY FLOW OVER THE GULF OF CALIFORNIA S OF 28N. THESE WINDS WILL DIMINISH WITHIN 18 HOURS OR SO AS THE HIGH PRES SHIFTS E. HIGH PRES W OF BAJA WILL SHIFT EWD SAT...ALLOWING MODERATE TO FRESH NLY FLOW OFF THE WRN COAST OF BAJA. AT THE MID AND UPPER LEVELS...A MID/UPPER TROUGH IS DIGGING THROUGH ERN TEXAS...N OF A BROAD UPPER ANTICYCLONE CENTERED OVER THE SW CARIBBEAN NEAR 13N77W. DIVERGENCE ALOFT ON THE SW SIDE OF THE UPPER ANTICYCLONE IS INTERACTING WITH LOW LEVEL CONVERGENCE ALONG THE ITCZ TO ENHANCE AN AREA OF SCATTERED MODERATE CONVECTION FROM THE EQUATOR TO 5N BETWEEN 87W AND 94W. A SHORT WAVE TROUGH WITH A WELL DEFINED VORTMAX NEAR 26N118W IS DIGGING ALONG THE COAST OF CENTRAL BAJA...BUT WILL HAVE LITTLE IMPACT ON SENSIBLE SURFACE WEATHER. FURTHER SOUTH...ELY TRADES OVER THE SW CARIBBEAN WILL PICK UP SAT INTO SUN AS HIGH PRES BUILDS N OF THE CARIBBEAN. THIS WILL IN TURN ALLOW FRESH TO STRONG ELY FLOW THROUGH GULF OF PAPAGAYO...AND FRESH NLY FLOW THROUGH GULF OF PANAMA BY LATE SUN. W OF 110W... THE BACKSIDE OF THE MID/UPPER SHORTWAVE TROUGH MOVING DOWN THE BAJA CALIFORNIA COAST IS DIGGING SWD ALONG 25 TO 125W. THE TROUGH HAS SPLIT OVER THE NW PORTION OF THE AREA WITH AN UPPER LEVEL CUT OFF LOW E OF HAWAII NEAR 20N146W. MEANWHILE FLATTENING UPPER RIDGE ALONG 120W APPEARS TO BE RELOADING ALONG 130W IN THE FACE OF THE DIGGING TROUGH NOTED ABOVE. THE RESULTING MID/UPPER WLY FLOW BETWEEN THE FLAT RIDGE AND THE TROUGHING TO THE N IS ADVECTING MAINLY UPPER LEVEL MOISTURE NWD THEN EWD ACROSS THE TROPICAL PACIFIC. DIVERGENCE ALOFT ON THE SRN EDGE OF THE UPPER RIDGE IS ENHANCING CONVECTION ALONG THE ITCZ W OF 115W. THE UPPER DIVERGENCE IS ALSO SUSTAINING A WEAK TROUGH ALONG THE ITCZ NEAR 139W. THE GRADIENT BETWEEN THE TROUGH AND SURFACE RIDGING WELL TO THE N IS MAINTAINING A BROAD AREA OF FRESH TRADE WINDS ROUGHLY BETWEEN 7N AND 16N W OF 120W. $$ COBB