000 AXPZ20 KNHC 061616 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SAT OCT 06 2012 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1500 UTC. ...SPECIAL FEATURE... THE EMBEDDED SURFACE LOW PRESSURE ALONG THE MONSOON TROUGH NEAR 14N118.7W HAS RECENTLY BEEN UPGRADED TO TROPICAL DEPRESSION FIFTEEN-E. THIS NEWLY CLASSIFIED T.D. HAS MAXIMUM SUSTAINED WINDS 30 KT GUSTS 40 KT AND WAS MOVING W OR 280 DEG AT 9 KT. ESTIMATED CENTRAL MINIMUM PRESSURE IS 1006 MB. CONVECTION ASSOCIATED WITH THIS LOW HAS BEEN IMPROVING OVERNIGHT...WITH A LARGE CLUSTER ACROSS THE NW SEMICIRCLE OF THE LOW BECOMING MORE OF A CURVED BAND THIS MORNING...WITH DEFINITIVE MID LEVEL CYCLONIC TURNING OVER OR JUST TO THE W OF THE SURFACE CENTER. A 0452 UTC ASCAT PASS LAST NIGHT SHOWED AN ELONGATED NE TO SW ALIGNED TROUGH... INDICATING THE POSITION OF THE MONSOON TROUGH...WITH SHARP CYCLONIC TURNING NEAR 13.8N116W...BUT DID NOT SUGGEST A CLOSED CIRCULATION. THE CONVECTIVE BANDING HAS IMPROVED CONSIDERABLY SINCE THAT TIME...AND A TROPICAL DEPRESSION HAS FORMED THIS MORNING. SCATTERED TO NUMEROUS MODERATE TO STRONG CONVECTION WAS OCCURRING WITHIN 270 NM NE AND 180 NM SW SEMICIRCLES...WHILE SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS ELSEWHERE WITHIN 360 NM SW QUADRANT. THE T.D. REMAINS UNDERNEATH AN UPPER LEVEL RIDGE...SANDWICHED BETWEEN TWO UPPER LEVEL HIGHS...AND IS IN A MARGINALLY FAVORABLE UPPER LEVEL ENVIRONMENT. COMPUTER MODEL GUIDANCE SUGGESTS THAT THE T.D. WILL MOVE WNW TO NW DURING THE NEXT COUPLE OF DAYS...AND HAS ONLY 36-48 HOURS FOR IMPROVED ORGANIZATION AND STRENGTHENING BEFORE REACHING COOLER SST'S AND MORE STABLE UPPER LEVEL CONDITIONS. THE T.D. IS FORECAST TO STRENGTHEN TO A TROPICAL STORM WITHIN 24 HOURS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH EXTENDS FROM 10N75W TO 08.5N97W TO 10N107W WHERE IT FRACTURES...THEN RESUMES FROM 17N111W THROUGH THE T.D. FIFTEEN-E AT 14N118.7W THROUGH LOW PRES NEAR 08.5N124W 1008 MB TO 08N128W...WHERE IT TRANSITIONS TO ITCZ...CONTINUING ON TO 09.5N134W TO BEYOND 07N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 180 NM S OF THE TROUGH E OF 107W. ...DISCUSSION... AS MENTIONED ABOVE...TWO UPPER LEVEL ANTICYCLONES STRADDLE THE NEW T.D....AND FORM AN UPPER LEVEL RIDGE N OF 10N EXTENDING BETWEEN 104W AND 132W. T.D. FIFTEEN-E HAS FORMED FROM A DEEP LAYERED EASTERLY WAVE...AND MIDDLE LEVEL CYCLONIC TURNING CAN STILL BE SEEN SURROUNDING THE T.D. IN WATER VAPOR IMAGERY. BROAD UPPER BLOCKING PATTERN PERSISTS ACROSS THE REGION THIS MORNING...WITH LITTLE CHANGES EXPECTED UNTIL THE RIDGE BEGINS TO FLATTEN MONDAY THROUGH TUESDAY. ELSEWHERE AT THE LOW LEVELS...BROAD BUT WEAK SURFACE RIDGING COVERS THE DISCUSSION AREA N OF 18N W OF 118W WITH AN ASSOCIATED 1018 MB HIGH CENTER AT 29N128W. SOUTHWESTERLY LOW LEVEL MONSOONAL WINDS AT 15-20 KT...ALONG WITH CROSS EQUATORIAL S SWELL...CONTINUES TO RESULT IN AN AREA OF SEAS 6-8 FT IN THE AREA BOUNDED FROM 08N TO 10N BETWEEN 114W-120W. WINDS WILL DIMINISH TO 15 KT AND SEAS WILL SUBSIDE TO 4-7 FT ON SUN. NW WINDS OCCURRING E OF THE SURFACE RIDGE WILL INCREASE TO 20-25 KT OVER THE AREA N OF 28N E OF 118W TO THE NORTHERN PORTION OF THE BAJA CALIFORNIA PENINSULA THIS AFTERNOON...AS THE MODERATE GRADIENT TIGHTENS...AND PERSIST THROUGH EARLY TUE. THIS GRADIENT IS THEN FORECAST TO RELAX AFTER TUE. LONG PERIOD SOUTHERN HEMISPHERIC S TO SW SWELLS ARE FORECAST BY WAVE MODEL GUIDANCE TO SPREAD ACROSS THE ENTIRE AREA E OF 120W INTO EARLY NEXT WEEK. THESE SWELLS ARE EXPECTED TO CULMINATE IN 4-5 FT SEAS ALONG MUCH OF THE COAST OF MEXICO INCLUDING THE SOUTHERN PORTION OF THE BAJA CALIFORNIA PENINSULA...AND THE SOUTHERN TIER OF THE GULF OF MEXICO. GAP WINDS...NW TO N WINDS OF 20-25 KT WERE DEPICTED OVERNIGHT BY A 0308 UTC ASCAT PASS THROUGH THE GULF OF TEHUANTEPEC AND DOWNSTREAM TO THE S FOR SOME 120 NM. THESE WINDS AREA EXPECTED TO BRIEFLY DIMINISH THIS AFTERNOON....THEN INCREASE AGAIN TO 20-25 KT STARTING LATE TONIGHT AND LAST THROUGH EARLY THIS WEEK AS HIGH PRES RIDGES SWD ACROSS CENTRAL AND SOUTHEASTERN MEXICO. $$ STRIPLING