000 AXPZ20 KNHC 032202 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC THU JUN 03 2010 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2030 UTC. ...TROPICAL WAVE... TROPICAL WAVE EXTENDS FROM NORTH CENTRAL NICARAGUA NEAR 14N85W TO 06N81W AND IS MOVING W NEAR 5 KT. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS WITHIN 180 NM W AND 90 NM E OF THE TROPICAL WAVE INCLUDING OVER WESTERN PANAMA...COSTA RICA...AND NICARAGUA. THE WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE AXIS LIES ALONG 09N85W TO 08N96W TO 10N109W TO 06N128W TO 08N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 60 NM EITHER SIDE OF THE ITCZ AXIS FROM 91W TO 111W AND WITHIN 75 NM N AND 120 NM S OF AXIS W OF 126W. TWO TROUGHS ARE EMBEDDED IN THE ITCZ. THE EASTERN TROUGH WAS FROM 13N89W TO 04N91W AND HAD SCATTERED MODERATE CONVECTION WITHIN 120 NM W OF THE TROUGH N OF 10N. THE WESTERN TROUGH WAS FROM 12N118W TO 07N123W AND HAD SCATTERED MODERATE CONVECTION WITHIN 120 NM W AND 90 NM E OF THE TROUGH. ...DISCUSSION... SUBTROPICS... A MORE AMPLIFIED UPPER PATTERN IS SETTING UP SHOP N OF 20N...WITH A SLOW MOVING UPPER LOW OVER THE NW GULF OF MEXICO FORECAST TO FORCE THE ANTICYCLONE CURRENTLY NEAR 30N123W ON A SLOW NORTHEASTWARD PATH INTO THE SW U.S. THE TAIL OF THE UPPER TROUGH HAS PINCHED OFF TWO UPPER LOWS...ONE NEAR 22N120W AND ANOTHER NEAR 25N140W. THE EASTERN LOW IS EXPECTED TO REMAIN RELATIVELY STATIONARY WHILE THE WESTERN LOW WILL SLOWLY SLIDE SW OVER THE NEXT TWO DAYS. UPPER LEVEL SOUTHWESTERLY WINDS WILL INCREASE TO 50 KT ON THE SE SIDE OF THE LOW BY SAT. REAR RIGHT QUADRANT DIFFLUENCE ALONG THE ITCZ ASSOCIATED WITH THIS JET SHOULD HELP THE CAUSE FOR CONVECTION JUST W OF THE AREA...WITH THE JET TRANSPORTING THE MID TO UPPER LEVEL CONVECTIVE BLOW OFF MOISTURE NORTHEASTWARD INTO W SUBTROPICAL WATERS. AT THE SURFACE...1022 MB HIGH PRES NEAR 28N132W WILL REMAIN DRIFT SLIGHTLY E WITH LITTLE CHANGE IN STRENGTH OVER THE NEXT TWO DAYS. THE HIGH WILL BE HELD SOUTH OF 30N BY A SERIES OF NORTHERN STREAM COLD FRONTS PASSING TO ITS N. NW TO N WINDS OFF THE CALIFORNIA COAST INDUCED BY THE PRESSURE GRADIENT BETWEEN LOWER PRES OVER THE SW U.S. AND THE RIDGE EXTENDING FROM THE HIGH CENTER TO THE CENTRAL CALIFORNIA COAST HAVE BROUGHT 8 FT NW SWELL INTO NE WATERS. 20 KT WINDS WILL SHIFT S INTO FORECAST WATERS ON SAT AS THE COLD FRONT CURRENTLY PASSING N OF THE SUBTROPICAL HIGH MOVES INTO THE WESTERN U.S. AND FURTHER INCREASES THE PRESSURE GRADIENT. THE 1504 WINDSAT PASS STILL SHOWS A SMALL AREA OF 20 KT TRADE WINDS N OF THE ITCZ OVER FAR W WATERS...BUT THESE WINDS ARE EXPECTED TO DIMINISH TO LESS THAN 20 KT OVERNIGHT UNDER THE INFLUENCE OF THE WEAK SUBTROPICAL HIGH. TROPICS... DIFFLUENT FLOW BETWEEN THE SW SIDE OF THE UPPER LEVEL ANTICYCLONE OVER THE CARIBBEAN NEAR 17N81W AND THE NW SIDE OF THE ANTICYCLONE OVER SOUTH AMERICA NEAR 10N62W LIES OVER A MAXIMUM OF DEEP LAYER MOISTURE NEAR THE ITCZ OVER FAR EASTERN WATERS. A SURFACE TROUGH FROM 13N89W TO 04N91W AND A TROPICAL WAVE PRIMARILY OVER CENTRAL AMERICA EXTENDING FROM 06N81W TO 14N85W LIE IN THIS REGION AND BOTH HAVE SIGNIFICANT CONVECTION ASSOCIATED WITH THEM DETAILED IN THE SECTIONS ABOVE. UPPER LEVEL NORTHEASTERLY WINDS ARE EXPECTED TO STRENGTHEN OVER THIS REGION AS THE ANTICYCLONE OVER THE CARIBBEAN SHIFTS NE OVER THE NEXT FEW DAYS. THIS SHOULD DECREASE THE LIKELIHOOD OF DEEP CONVECTION. THE OTHER FOCUS FOR CONVECTION IS A TROUGH EMBEDDED IN THE ITCZ FROM 12N118W TO 07N123W. THIS TROUGH LIES UNDER A REGION A LIGHT UPPER LEVEL FLOW WEDGED BETWEEN A ZONAL 30-40 KT WESTERLY JET TO ITS N ALONG 20N AND 20-30 KT NE WINDS PRIMARILY S OF 09N. CONDITIONS SHOULD REMAIN RELATIVELY UNCHANGED NEAR THE TROUGH ON FRI...BUT LOOK FOR INCREASED WESTERLY WIND SHEAR TO APPROACH THE SYSTEM ON SAT AS THE PATTERN ALOFT TO THE N BECOMES MORE AMPLIFIED. $$ SCHAUER