000 AXPZ20 KNHC 310906 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SAT MAR 31 2007 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0845 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 2N78W 6N85W 4N110W 3N140W. SCATTERED MODERATE CONVECTION WITHIN 120 NM S OF AXIS BETWEEN 84W-96W. ...DISCUSSION... SUBTROPICAL PACIFIC... STRONG ZONAL FLOW IN THE UPPER LEVEL WESTERLIES IS BECOMING ESTABLISHED OVER THE SUBTROPICAL PAC WATERS NOW THAT THE CLOSED UPPER LOW OVER THE SW UNITED STATES IS FINALLY EJECTING NE. A BROAD RIDGE IS LOCATED MAINLY N OF THE AREA JUST OFF THE WRN U.S. COAST...TRANSITIONING INTO BROAD CYCLONIC FLOW ACROSS NRN MEXICO ON THE UNDERBELLY OF THE U.S. TROUGH. UPPER CONFLUENCE INTO THE TROUGH IS PRODUCING MODERATE/STRONG SUBSIDENCE STREAMING INTO NW MEXICO...PRODUCING MAINLY CLOUD-FREE SKIES E OF 125W EXCEPT FOR A FEW CIRRUS OVER THE MEXICAN PLATEAU. THE SUBTROPICAL JET HAS BECOME A LITTLE MORE ACTIVE IN RESPONSE TO A DIGGING TROUGH S OF THE HAWAIIAN ISLANDS...AND A 90-100 KT JET STREAK NOW EXTENDS FROM 21N140W TO 20N115W WITH INCREASED CIRRUS STREAMING INTO THE AREA. HIGH PRES REMAINS IN CONTROL AT THE SFC...BUT IT HAS SLID A BIT S TO 35N132W WITH A SLIGHTLY LOWERED PRES OF 1026 MB. THIS HAS CAUSED THE TRADES TO WEAKEN COMPARED TO THE LAST FEW DAYS. TROPICAL PACIFIC... WITH THE SUBTROPICAL JET STREAMING INTO THE AREA ALONG 21N...THE UPPER FLOW OVER THE TROPICAL AREAS OF THE PACIFIC IS MAINLY WESTERLY BUT THEN DIVES SE AS IT FLOWS INTO A BROAD UPPER TROUGH LOCATED ALONG 98W. A WEAK MID-LEVEL RIDGE IS ALONG 15N BUT THIS REGION IS BEING OVERLAPPED BY THE ADVANCING CIRRUS SHIELD FROM THE W. THE ITCZ REMAINS LARGELY CONVECTIVELY INACTIVE...ALTHOUGH THE BROAD TROUGH ALONG 98W DOES APPEAR TO BE PRODUCING ENOUGH UPPER DIFFLUENCE TO AID SOME TSTMS NEAR THE ITCZ BETWEEN 84W-95W. OTHERWISE THE ENTIRE AREA E OF 110W IS UNDER A BROAD SUBSIDENT ENVIRONMENT WITH MID-LEVEL RIDGING CENTERED OVER SE MEXICO. ON THE MARINE FRONT...A SERIES OF LONG-PERIOD SWELL TRAINS CONTINUES TO MOVE CLOSER TO THE MEXICAN/CENTRAL AMERICAN COAST...THE FIRST OF WHICH IS EXPECTED TO ARRIVE THIS MORNING WITH PERIODS NEAR 17 SEC. DANGEROUS SURF CONDITIONS ARE LIKELY TO DEVELOP THROUGH THE DAY ESPECIALLY ON THE SW-FACING BEACHES BETWEEN PANAMA AND BAJA CALIFORNIA. A SECOND SWELL TRAIN IS EXPECTED TO ARRIVE AT THE COAST LATE MON AND SHOULD PRODUCE SIMILAR CONDITIONS. $$ BERG