000 AXPZ20 KNHC 270322 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC MON AUG 27 2007 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 0300 UTC. ...TROPICAL WAVES... TROPICAL WAVE OVER GUATEMALA ALONG 90W N OF 6N MOVING W 10-15 KT. TSTM ACTIVITY WHICH WAS MOVING WWD ACROSS NICARAGUA AND HONDURAS EARLIER IN THE DAY HAS CONSOLIDATED INTO A LARGE CONVECTIVE CLUSTER THAT IS MOVING OFFSHORE ACROSS THE GULF OF FONSECA. SCATTERED MODERATE/ISOLATED STRONG CONVECTION N OF 10N BETWEEN 85W-89W. TROPICAL WAVE ALONG 102W N OF 8N MOVING W 10-15 KT WITH A 1006 MB LOW NEAR 16N102W. THE CIRCULATION AROUND THE LOW HAS BECOME LESS ORGANIZED DURING THE PAST FEW HOURS...BUT SURFACE PRESSURES AND WIND OBSERVATIONS FROM ACAPULCO AND IXTAPA/ZIHUATANEJO INDICATE THAT THERE MUST BE A LOW OFFSHORE. IN ALL LIKELIHOOD...THE LOW IS PROBABLY JUST A MINIMUM IN PRESSURE WITHIN THE ELONGATED TROUGH/ITCZ OFF THE COAST. SCATTERED MODERATE/ISOLATED STRONG CONVECTION N OF 11N BETWEEN 99W-108W. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N77W 10N87W 15N100W 12N110W 11N140W. SCATTERED MODERATE N OF 7N BETWEEN 81W-93W. SCATTERED MODERATE/ISOLATED STRONG FROM 10N-17N BETWEEN 98W-107W. WIDELY SCATTERED SHOWERS/TSTMS WITHIN 90 NM OF THE AXIS BETWEEN 112W-120W AND W OF 137W. ...DISCUSSION... OFF THE MEXICAN COAST... STRONG CROSS-EQUATORIAL LOW-LEVEL FLOW CONTINUES TO FEED NWD TOWARDS THE ELONGATED TROUGH OF LOW PRES JUST OFF THE COAST OF MEXICO AND CENTRAL AMERICA. THE AXIS OF LOW-LEVEL SPEED CONVERGENCE IS SLIGHTLY OFFSET FROM THE WIND SHIFT ASSOCIATED WITH THE TROUGH...SO SOME OF THE TSTM ACTIVITY IS DISPLACED ABOUT 350 NM S OF THE COAST...ESPECIALLY BETWEEN NICARAGUA AND THE GULF OF TEHUANTEPEC. HOWEVER...TSTM ACTIVITY WHICH HAD FORMED OVER LAND ACROSS MEXICO AND CENTRAL AMERICA HAS DRIFTED SWD IN SOME CASES AND NOW SCATTERED MODERATE CONVECTION LIES ALONG THE COAST BETWEEN COSTA RICA AND MAZATLAN MEXICO. FARTHER W...THE SPEED CONFLUENCE AND WIND SHIFT ARE MORE ALIGNED BETWEEN 95W-105W...AND THUS DEEP CONVECTION IS MUCH CLOSER TO THE 1006 MB AREA OF LOW PRES ABOUT 140 NM WSW OF ACAPULCO. MUCH OF THE CONVECTION OVER THE REGION IS BEING VENTILATED BY STRONG NE/E UPPER LEVEL FLOW WHICH IS ADVECTING THE CIRRUS TOWARDS THE EQUATOR. REMAINDER OF AREA... THE WRN PART OF THE DISCUSSION AREA IS MUCH QUIETER THAN AREAS TO THE E. THERE IS MUCH LESS MOISTURE TO WORK WITH COURTESY OF A LARGE AREA OF MODERATE/STRONG SUBSIDENCE N OF 10N W OF 120W. AN UPPER LOW LOCATED ABOUT 250 NM SW OF THE SRN TIP OF BAJA CALIFORNIA IS HELPING TO DRAW MOISTURE NWD ACROSS MEXICO. THE TRADES ACROSS THE TROPICAL PACIFIC ARE ALMOST NON-EXISTENT WITH LOW-LEVEL WESTERLY FLOW SPANNING BETWEEN THE LOW/WAVE NEAR 100W AND 135W. A WEAK 1010 MB LOW IS LOCATED NEAR 18N134W AND IS MOVING SW 5-10 KT DUE TO A STRENGTHENING RIDGE TO THE N. THE LOW IS EXPECTED TO BECOME ABSORBED WITHIN THE ITCZ OVER THE NEXT 48-72 HRS. $$ BERG