000 AXPZ20 KNHC 140958 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC THU AUG 14 2014 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0945 UTC. ...SPECIAL FEATURES... TROPICAL STORM KARINA WAS CENTERED NEAR 17.4N 115.2W AT 14/0900 UTC...OR ABOUT 443 NM S OF THE SOUTHERN TIP OF BAJA CALIFORNIA...MOVING W OR 275 DEG AT 12 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 998 MB. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. KARINA IS EXHIBITING A LARGE CANOPY ...RESEMBLING A CENTRAL DENSE OVERCAST...OF VERY DEEP COLD TOP CONVECTION CONSISTING OF THE NUMEROUS STRONG TYPE WITHIN 30 NM NW AND 90 NM SE SEMICIRCLES OF THE CENTER. SCATTERED STRONG CONVECTION IS ELSEWHERE WITHIN 75 NM NW AND 120 NM SE SEMICIRCLES OF THE CENTER. THE OUTFLOW PATTERN LOOKS GOOD IN THE WESTERN SEMICIRCLE...BUT APPEARS RESTRICTED ON THE EASTERN SEMICIRCLE DUE TO THE UPPER NE SHEAR. KARINA IS FORECAST TO GRADUALLY STRENGTHEN WHILE CONTINUING ON A WESTWARD MOTION REACHING HURRICANE INTENSITY NEAR 18N119W IN 24 HOURS. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. LOW PRES IS EMBEDDED IN THE MONSOON TROUGH NEAR 12N139W WITH A LOW PRES OF 1008 MB MOVING SLOWLY NW. NO SIGNIFICANT CONVECTION IS NOTED CURRENTLY IN ASSOCIATION WITH THE LOW PRES. ASSOCIATED WINDS ARE 20 KT OR LESS WHILE AN AREA OF 7-8 FT SEAS IS LOCATED FROM 14N TO 16N W OF 137W. THIS AREA OF SEAS IS SUBJECT TO ADJUSTMENTS IN FUTURE FORECASTS ALONG WITH THE INTRODUCTION OF POSSIBLE SIGNIFICANT WINDS PENDING DEVELOPMENTS WITH THE LOW PRES AS IT CONTINUES TO HAVE A MEDIUM CHANCE FOR TROPICAL CYCLONE FORMATION DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... A TROPICAL WAVE EXTENDS ALONG 101W FROM 10N TO ALONG 101W INTO CENTRAL MEXICO MOVING W AT ABOUT 10-15 KT. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM E OF THE WAVE FROM 13N TO 16N. A TROPICAL WAVE HAS RECENTLY ENTERED THE FAR EASTERN PART OF THE AREA...AND IS ALONG 87W N OF 09N TO INLAND FAR NW NICARAGUA AND CENTRAL HONDURAS TO THE GULF OF HONDURAS MOVING W NEAR 20 KT. NO SIGNIFICANT CONVECTION IS NOTED WITH THIS WAVE. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE ITCZ EXTENDS FROM 10N86W TO 13N98W TO 12N95W...THEN RESUMES FROM 13N102W TO 16N107W. MONSOON TROUGH EXTENDS FROM 14N115W TO 11N130W TO 12N134W TO LOW PRES NEAR 12N139W 1008 MB TO 11N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS NOTED WITHIN 120 NM N OF THE MONSOON TROUGH BETWEEN 120W-126W...AND ALSO W OF 138W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF THE MONSOON TROUGH BETWEEN 130W-134W. ...DISCUSSION... IN THE UPPER LEVELS...AN UPPER RIDGE EXTENDS FROM N CENTRAL MEXICO ACROSS SOUTHERN BAJA PENINSULA TO 16N130W. NE WINDS ON THE SOUTHERN PERIPHERY OF THE RIDGE HAVE BEEN IMPACTING TROPICAL STORM KARINA WITH NE SHEAR...HOWEVER THESE WINDS HAVE RECENTLY WEAKENED. CONVECTIVE CLUSTERS OF THE STRONG TYPE HAVE RECENTLY MOVED OFFSHORE THE MEXICAN COAST UNDER NE FLOW GENERATED BY AN ANTICYCLONE OVER FAR NW MEXICO NEAR 31N107W...AND OVER THE WATERS FROM 20N-24N BETWEEN 106W-110W. A WEAK UPPER TROUGH EXTENDS FROM SOUTHERN CALIFORNIA SW TO 28N122W TO NEAR 27N130W. WATER VAPOR IMAGERY SHOWS MODERATE TO STRONG SUBSIDENCE WITH ASSOCIATED DRY AND STABLE CONDITIONS TO THE N OF A LINE FROM 27N110W TO 20N122W TO 20N140W. SE OF THIS SAME LINE...PLENTIFUL DEEP ATMOSPHERIC MOISTURE IS OBSERVED...AND IS SURROUNDING KARINA. NOCTURNAL SCATTERED STRONG CONVECTION MOVING SW IN CLUSTERS HAS JUST DEVELOPED DURING THE RECENT HOURS WITHIN 30 NM EITHER SIDE OF LINE FROM 14N92W TO 15N95W. THIS ACTIVITY IS BEING AIDED BY A MID TO UPPER CYCLONIC CIRCULATION THAT STRETCHES FROM THE WESTERN GULF OF MEXICO SW TO INLAND CENTRAL MEXICO. THIS ACTIVITY SHOULD PERSIST INTO THE MORNING HOURS. AT THE SURFACE...THE SURFACE A WEAK RIDGE EXTENDS FROM 30N131W SE TO 26N121W. A DISSIPATING COLD FRONT SUPPORTED BY THE EARLIER MENTIONED UPPER TROUGH EXTENDS FROM NEAR 32N120W SW TO 29N130W TO 29N138W. A WEAK SURFACE TROUGH PERSISTS ALONG A POSITION FROM 18N128W TO 13N130W. ISOLATED WEAK CONVECTION IS WITHIN 120 NM EITHER SIDE OF THE TROUGH. THE TROUGH IS FORECAST TO MOVE WESTWARD REACHING NEAR 131W BY EARLY FRI...THEN BECOME LESS DEFINED AS IT APPROACHES THE SPECIAL FEATURES LOW PRES LATER ON FRI AND INTO SAT. GAP WINDS... AN ASCAT PASS FROM LATE LAST NIGHT SHOWED A SMALL AREA OF N 20- 25 KT ACROSS THE FAR NORTHERN GULF OF TEHUANTEPEC. THESE WINDS FUNNELED IN ACROSS THE ISTHMUS OF TEHUANTEPEC DURING THE OVERNIGHT HOURS AS FROM DRAINAGE FLOW OFF SE MEXICO KICKED IN. ALSO THE LATEST SURFACE ANALYSIS ALSO INDICATED A TIGHTER PRES GRADIENT THERE COMPARED TO WHAT HAD BEEN OBSERVED IN PREVIOUS ANALYSES. FRESH GAP WIND FLOW OF 20-25 KT THROUGH THE GULF OF PAPAGAYO IN ENHANCED GRADIENT LEFT IN THE WAKE OF THE WAKE OF THE TROPICAL WAVE CURRENTLY ALONG 87W IS FORECAST TO MATERIALIZE AGAIN DURING THE OVERNIGHT HOURS THROUGH SAT. SEAS TO 8 FT ARE POSSIBLE IN THE DOWNSTREAM PLUME OF THESE WINDS. $$ AGUIRRE