000 AXPZ20 KNHC 210932 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC FRI JUL 21 2006 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 0915 UTC. ...SPECIAL FEATURES... HURRICANE DANIEL IS CENTERED NEAR 13.2N 125.3W...OR ABOUT 1050 NM SW OF THE SOUTHERN TIP OF THE BAJA PENINSULA...AT 21/0900 UTC MOVING WNW 9 FT. MAXIMUM SUSTAINED WIND SPEED HAVE DECREASED SLIGHTLY TO 115 KT WITH GUSTS TO 140 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 948 MB. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. DANIEL HAS BEEN OSCILLATING BETWEEN HAVING ONE MAIN EYEWALL AND TWO CONCENTRIC EYEWALLS...AND NOW APPEARS TO BE IN THE LATTER STAGE. THE MAIN RING OF CONVECTION IS ABOUT 50 NM FROM THE CENTER BUT NOW A NEW RING OF CONVECTION APPEARS TO BE FORMING WITHIN 20-25 NM W AND SW OF THE CENTER. THE HURRICANE HAS A SLIGHT OBLONG STRUCTURE IN A NW/SE FASHION...POSSIBLY DUE TO SOME ELY SHEAR COURTESY OF AN UPPER LEVEL ANTICYCLONE TO ITS NE NEAR 21N122W. THIS ENVIRONMENT ALSO APPEARS TO BE DISPLACING THE BEST UPPER LEVEL OUTFLOW TO THE W OF THE SYSTEM. NUMEROUS MODERATE/STRONG CONVECTION IS WITHIN 150 NM N AND 120 NM S SEMICIRCLES. A 1008 MB LOW IS CENTERED NEAR 11N103W...OR 375 NM SSW OF ACAPULCO MEXICO...DRIFTING TO THE NW. THE CONVECTIVE STRUCTURE NEAR THE LOW IS ALMOST THE SAME AS THIS TIME YESTERDAY... ALTHOUGH A 0046 UTC QUIKSCAT PASS REVEALED THAT THE WIND FIELD HAS INCREASED STRADDLING THE ITCZ. ALSO...THE LOW-LEVEL CENTER IS STILL SOMEWHAT EXPOSED ON THE NE SIDE OF THE CONVECTIVE CLUSTER. THE GFS ENSEMBLE MEAN INDICATES THAT THE LOW SHOULD CONTINUE TO ORGANIZE OVER THE NEXT 24 HRS AND BECOME MORE CONSOLIDATED (CONTRARY TO GUIDANCE FROM THE PAST COUPLE OF DAYS)...THEREFORE TROPICAL CYCLONE DEVELOPMENT IS POSSIBLE WITHIN THE NEXT 24-36 HRS. NUMEROUS MODERATE/STRONG CONVECTION IS WITHIN 150 NM W SEMICIRCLE. ...TROPICAL WAVES... TROPICAL WAVE ALONG 87W N OF 5N MOVING W 15 KT. THE WAVE HAS AN ILL-DEFINED CIRCULATION ALTHOUGH AN AXIS OF DEEP CONVECTION EXTENDS FROM NE COSTA RICA SWD TO 3N MOVING WWD. SCATTERED MODERATE/STRONG CONVECTION FROM 3N-13N BETWEEN 83W-90W. ..ITCZ... ITCZ IS CENTERED ALONG 7N77W 11N93W 11N108W 14N117W 7N127W 12N136W 11N140W. SCATTERED MODERATE/STRONG CONVECTION FROM 3N-13N BETWEEN 83W-90W. WIDELY SCATTERED SHOWERS/TSTMS WITHIN 60 NM OF THE AXIS BETWEEN 107W-116W. SEE SPECIAL FEATURES FOR CONVECTION ASSOCIATED WITH LOW NEAR 11N103W. ...DISCUSSION... A CUT-OFF MID-LEVEL LOW...COLLOCATED WITH A SHARP UPPER TROUGH...IS CENTERED NEAR 19N137W AND IS DRIFTING W TOWARDS 140W WITH STRONG SUBSIDENCE WITHIN ABOUT 400 NM OF THE CENTER. AN ELONGATED SURFACE TROUGH...WHICH IS A MANIFESTATION OF A MERGER BETWEEN THE REMNANT LOW OF CARLOTTA AND AN ITCZ LOW...IS LOCATED ALONG 137W AND IS ALSO MOVING W WITHIN THE ELY TRADES. THIS STACKED AREA OF LOW PRES WILL ULTIMATELY CAUSE HURRICANE DANIEL TO TAKE A MORE NW COURSE DUE TO A WEAKENED RIDGE. FARTHER E...A MID/UPPER LOW IS LOCATED JUST SW OF SOCORRO ISLAND NEAR 18N112W AND ORIGINATED FROM A TROUGH WHICH WAS LOCATED ALONG THE PACIFIC COAST OF MEXICO. DEEP-LAYERED MOISTURE IS LOCATED E/SE OF THE LOW AND IS FLOWING N TOWARDS MEXICO BETWEEN THE GULF OF TEHUANTEPEC AND PUERTO VALLARTA. A LARGE UPPER LEVEL HIGH HAS DEVELOPED OVER THE ISTHMUS OF TEHUANTEPEC AND IS PROVIDING UPPER LEVEL DIVERGENCE THAT IS SUPPORTING TSTMS WITHIN 120 NM OF THE MEXICAN COAST BETWEEN 94W-106W (LIKELY DUE TO THE NIGHTTIME LAND BREEZE BOUNDARY). THE HIGH IS ALSO PRODUCING RATHER STRONG ELY SHEAR OVER THE WATERS E OF 110W AND IS KEEPING THE LOW-LEVEL CENTER OF THE LOW NEAR 11N103W PARTIALLY EXPOSED ON THE E SIDE OF THE DEEP CONVECTION. $$ BERG