000 AXPZ20 KNHC 010943 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC WED OCT 01 2008 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0915 UTC. ...SPECIAL FEATURES... TROPICAL DEPRESSION 14E HAS FORMED NEAR 16N116W...APPROXIMATELY 530 NM SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA. A LARGE BAND OF STRONG CONVECTION IS NOTED WRAPPING AROUND THE WESTERN AND SOUTHERN SIDES OF THE LOW ON RECENT IR SATELLITE IMAGERY. SHORT WAVE IR IMAGERY SHOWED THE CONVECTION STARTING TO WRAP AROUND TO THE SOUTHEAST OF THE CENTER AS WELL. A QUIKSCAT PASS FROM AROUND 02Z SHOWED 20 TO 30 KT WINDS WITHIN 300 NM OF THE CENTER...WITH A LARGER AREA OF PERSISTENT MODERATE TO STRONG SOUTHERLY WINDS CONVERGING INTO THE SYSTEM SOUTH OF THE ITCZ. T.D. 14E IS SITUATED ON THE SOUTHWEST SIDE OF AN UPPER ANTICYCLONE...WHERE DIVERGENT SOUTHEAST FLOW ALOFT IS ENHANCING CONVECTION. THE DEPRESSION IS OVER WATERS WITH SEA SURFACE TEMPERATURES AROUND 82 DEG F...BUT IS EXPECTED TO DRIFT INTO SLIGHTLY COOLER WATERS OVER THE NEXT COUPLE OF DAYS. A SECOND LOW PRES AREA IS CENTERED NEAR 12N98W...OR APPROXIMATELY 330 NM SW OF THE GULF OF TEHUANTEPEC. A COMPARISON OF RECENT MICROWAVE IMAGERY AND IR IMAGERY SHOWS THIS FEATURE HAS AN EXPOSED CENTER. THE LOW IS SITUATED SOUTH OF AN UPPER RIDGE AXIS...SUPPLYING MODERATE E SHEAR AND HOLDING CONVECTION DOWNSHEAR TO THE WEST OF THE CENTER. A QUIKSCAT PASS FROM 00Z SHOWS STRONG NE WINDS OUT OF THE GULF OF TEHUANTEPEC CONVERGING INTO THE NORTH SIDE OF THE LOW...WITH MODERATE TO STRONG SW WINDS CONVERGING INTO THE LOW ON ITS EAST SIDE. A NEARBY SHIP OBSERVATION IN CONJUNCTION WITH THE QUIKSCAT HINT THAT THE LOW IS PART OF AN ELONGATED TROUGH TO THE NORTHEAST. EASTERLY SHEAR IS EXPECTED TO WEAKEN OVER THE NEXT COUPLE OF DAYS...ALLOWING THE POSSIBILITY THAT THE LOW MAY INTENSIFY. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N78W 7N85W 13N93W 11N105W 12N111W 08N125W 12N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS WITHIN 120 NM OF THE AXIS BETWEEN 97W AND 105W. SCATTERED MODERATE CONVECTION WITHIN 120 NM S OF AXIS BETWEEN 130W AND 135W. ...DISCUSSION... E OF 120W... MAIN FORECAST ISSUE FOR AT LEAST THE NEXT COUPLE OF DAYS WILL BE DEVELOPMENT AND TRACK OF TROPICAL DEPRESSION 14E AS MENTIONED ABOVE. FOR FURTHER DETAILS SEE NHC FORECAST AND DISCUSSION UNDER WMO HEADER WTPZ24 KNHC OR AWIPS HEADER TCMEP4. IN ADDITION...QUIKSCAT SHOWS A BROAD SWATH OF MODERATE TO STRONG SOUTHERLY WINDS TO THE SOUTH OF T.D. 14E CONVERGING INTO THE SYSTEM. GLOBAL MODELS GENERALLY SHOW THIS FLOW DIMINISHING OVER THE NEXT COUPLE OF DAYS...EXCEPT CLOSER TO THE STORM CENTER. FURTHER EAST...QUIKSCAT DATA FROM AROUND 00Z SHOW 20 TO 30 KT NORTHERLY WINDS PERSISTING THROUGH THE GULF OF TEHUANTEPEC THIS EVENING...CONVERGING INTO THE LOW NEAR 12N98W. PREVIOUS SURFACE ANALYSES INDICATED A TROPICAL WAVE S OF EL SALVADOR MIGRATING WESTWARD. THIS APPEARS TO BE GETTING ABSORBED INTO THE LOW JUDGING BY THE WIND FIELD. ALOFT...AN UPPER ANTICYCLONE CENTERED NEAR 21N112W WITH A RIDGE AXIS EXTENDING EAST THROUGH GUATEMALA IS PROVIDING MODERATE EASTERLY SHEAR S OF 17N. THE UPPER ANTICYCLONE WILL WEAKEN AS AN UPPER TROUGH DIGS TO THE NORTH OF THE AREA THROUGH THU...ALLOWING THE SHEAR TO DIMINISH. MEANWHILE SOUTHERLY CROSS EQUATORIAL SWELL AROUND 8 FT WILL PUSH AS FAR AS 10N THROUGH THU. W OF 120W... AN UPPER TROUGH IS DIGGING THROUGH 135W N OF 22N. AN ASSOCIATED COLD FRONT EXTENDS FROM 30N132W TO 22N140W. SHIP OBSERVATIONS AND QUIKSCAT DATA SHOW ONLY A SMALL BAND OF 20 KT SOUTH WINDS AHEAD OF THE FRONT N OF 28N. THE FRONT WILL WEAKEN THROUGH TODAY AS THE UPPER SUPPORT LIFTS TO THE NE. EVEN AS THE FRONT WASHES OUT...FRESH SWELL UP TO 12 FT IS EXPECTED TO PUSH INTO THE AREA BEHIND THE FRONT AND PROPAGATE TO THE SE. EXPECT AN AREA OF CONFUSED SEAS BY LATE TOMORROW FROM 12N TO 24N BETWEEN 120W AND 130W AS THE SWELL ENCOUNTERS SEAS RELATED TO T.D. 14E MIGRATING WESTWARD. FURTHER SOUTH...A STATIONARY AND WEAK 1011 MB LOW IS EMBEDDED ALONG THE ITCZ NEAR 11N137W WITH ONLY MODEST CONVECTION NOTED. $$ CHRISTENSEN