000 AXPZ20 KNHC 230251 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC FRI APR 23 2010 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 0130 UTC. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE AXIS WAS ANALYZED FROM 05N77W TO 07N88W TO 05N101W TO 09N120W TO 04N140W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WITHIN 270 NM N AND 90 NM S OF THE ITCZ AXIS BETWEEN 106W AND 119W. SCATTERED MODERATE CONVECTION WITHIN 180 NM N OF THE ITCZ AXIS BETWEEN 96W AND 100W. ...DISCUSSION... AN AMPLIFIED MID TO UPPER LEVEL LOW OVER THE U.S. DESERT SW WILL DRIFT E THROUGH THE FOUR CORNERS REGION FRI. THE 1840 AND 1700 UTC ASCAT PASSES SHOWED 20 TO 25 KT NW TO N WINDS OVER NE WATERS ASSOCIATED WITH THE PRES GRADIENT BETWEEN THIS TROUGH AND 1031 MB HIGH PRES NW OF THE AREA NEAR 36N144W. THIS PRES GRADIENT HAS ALSO BROUGHT W TO NW WINDS TO 20 KT IN THE NORTHERN GULF OF CALIFORNIA ACCORDING TO ASCAT...WITH HIGHER WINDS POSSIBLE IN THE RELATIVELY SMALL AREAS DOWNWIND OF MOUNTAIN PASSES. SIMILARLY...THE PRES GRADIENT S OF THE HIGH BETWEEN IT AND THE ITCZ HAS BROUGHT STRONG EASTERLY TRADE WINDS TO W WATERS ACCORDING TO THE 1942 UTC ASCAT PASS. THE HIGH PRES SYSTEM IS FORECAST TO CONTINUE TO WEAKEN AS IT IS NUDGED EASTWARD OVER THE NEXT TWO DAYS BY A COLD FRONT PASSING OVER ITS NW EDGE. AS THE TROUGH OVER THE SW U.S. MOVES EAST FRI...LOOK FOR THE PRES GRADIENT TO WEAKEN ENOUGH TO BRING WINDS BELOW 20 KT OVER NE WATERS AND THE GULF OF CALIFORNIA BY AFTERNOON. TRADE WINDS WILL SHRINK IN AREA THE NEXT FEW DAYS IN RESPONSE TO THE WEAKENING HIGH PRES TO THE N. STRONG MOISTURE CONVERGENCE ALONG THE ITCZ BETWEEN THE NE TRADES AND STRONG SE TRADES S OF THE EQUATOR HAS PROVIDED FUEL FOR CONVECTION BETWEEN 105W AND 120W. A TROUGH EMBEDDED IN THE ITCZ FROM 12N122W TO 05N122W HAS FURTHER HELPED POOL LOW LEVEL MOISTURE. THE ASCAT PASS FROM 1704 UTC SHOWS TO 20 T0 25 KT SOUTHERLY FLOW ON THE SE SIDE OF THE TROUGH. AN UPPER JET WITH WEST-SOUTHWESTERLY WINDS OF 60 KT OR GREATER JUST N OF THE SURFACE LOW IS CURRENTLY TRANSPORTING MID TO UPPER LEVEL MOISTURE INTO CENTRAL MEXICO. THE PROXIMITY OF THIS JET WILL LIKELY INHIBIT ANY FURTHER DEVELOPMENT OF THE TROUGH...WITH MOST OF THE GUIDANCE CARRYING A SLOW W MOVING TROUGH FRI AND DISSIPATING IT FRI EVENING. CURRENTLY...A WEAK UPPER RIDGE AXIS LIES SE OF THE TROUGH AND THE DIFFLUENCE ASSOCIATED WITH IT IS SUPPORTING THE DEEP CONVECTION ALONG THE ITCZ E OF THE TROUGH. THE UPPER RIDGE WILL SHIFT E OVER THE NEXT TWO DAYS...AWAY FROM THE LOW LEVEL SYSTEM. AS A RESULT...CONVECTION IS EXPECTED TO BECOME LESS PREVALENT NEAR THE TROUGH AS IT WEAKENS FRI. FARTHER E...AN ANTICYCLONE IS DEVELOPING ALOFT NEAR 07N103W. THIS AREA IS CURRENTLY IN A RELATIVE MINIMUM FOR LOW TO MID LEVEL MOISTURE ACCORDING TO SATELLITE PRECIPITABLE WATER IMAGERY. A NEW POOL OF MOISTURE HAS MOVED W INTO THE EASTERN PACIFIC ALONG THE ITCZ E OF 92W AND WILL SUPPLY SOME FUEL FOR INCREASED CONVECTION OVER THE NEXT TWO DAYS TO THE DIFFLUENT REGION ASSOCIATED WITH THE DEVELOPING ANTICYCLONE. OVER FAR S WATERS...THE STRONG SE TRADES SOUTH OF THE EQUATOR ARE HELPING THE CAUSE FOR CROSS-EQUATORIAL SWELL WITH WAVES TO 9 FT OVER S CENTRAL WATERS THROUGH SAT. SW SWELL IS ALSO CONTRIBUTING TO WAVE HEIGHTS OVER SE WATERS ABOVE 8 FT. SHIP OBSERVATION A8IT6 REPORTED 9 FT WITH 20 KT S WINDS NEAR 02N86W AT 0000 UTC. LOW LEVEL CONVERGENCE IS INCREASING BETWEEN THE 20-25 KT NE WINDS IN THE SW CARIBBEAN A 0000 UTC AND THE SOUTHERLY WINDS IN SE WATERS...BUT 20-30 KT SOUTHERLY UPPER FLOW ALOFT IS INHIBITING CONVECTION HERE. THE INCREASED LOW LEVEL VORTICITY MAY MAKE THE REGION RIPE FOR THE DEVELOPMENT OF A SURFACE LOW OVER THE NEXT FEW DAYS AS SOME OF THE GUIDANCE SUGGESTS. IN ADDITION...UPPER LEVEL WINDS SHOULD BECOME MORE DIFFLUENT AND ALLOW FOR AN INCREASED CHANCE OF DEEP CONVECTION IN SE WATERS OVER THE NEXT TWO DAYS. $$ SCHAUER