000 AXPZ20 KNHC 200920 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC WED AUG 20 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 0900 UTC. ...SPECIAL FEATURES... TROPICAL STORM KARINA CENTERED NEAR 15.9N 135.9W AT 20/0900 UTC MOVING W OR 270 DEG AT 4 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. MAXIMUM SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 120 NM OF THE CENTER EXCEPT IN THE NW QUADRANT. KARINA IS EXPECTED TO BECOME NEARLY STATIONARY DURING THE NEXT 24 HOURS WITH LITTLE CHANGE IN INTENSITY. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. TROPICAL STORM LOWELL CENTERED NEAR 18.7N 121.0W AT 20/0900 UTC MOVING NW OR 305 DEG AT 4 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 996 MB. MAXIMUM SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS WITHIN 180 NM OF THE S SEMICIRCLE. LOWELL REMAINS A VERY LARGE CIRCULATION. A PAIR OF ALTIMETER PASSES AROUND 0400 UTC PROVIDED EXCELLENT SEA HEIGHT DATA FOR THE TROPICAL CYCLONE...INCLUDING HIGH CONFIDENCE IN THE RADIUS OF 12 FT SEAS. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS. WEAK LOW PRES EMBEDDED IN THE MONSOON TROUGH NEAR 08N93W AT THE SOUTHERN EXTENSION OF A TROPICAL WAVE ALONG 94W/95W IS PRODUCING SCATTERED MODERATE ISOLATED STRONG CONVECTION OVER A BROAD AREA FROM 05N TO 09N BETWEEN 90W AND 99W. MODEL GUIDANCE INDICATES PERIPHERAL WINDS WILL INCREASE DOWNSTREAM FROM GULF OF PAPAGAYO TONIGHT WHICH WILL ALLOW THE LOW TO BECOME BETTER ORGANIZED AS IT CONTINUES WESTWARD. THIS LOW HAS A MEDIUM CHANCE FOR TROPICAL CYCLONE DEVELOPMENT DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... A TROPICAL WAVE MOVING W AT 15 KT EXTENDS FROM THE LOW PRES NEAR 08N93W TO GULF OF TEHUANTEPEC ALONG 94W/95W. SCATTERED MODERATE TO STRONG CONVECTION IS N OF 14.5N BETWEEN 93W AND 96W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A MONSOON TROUGH EXTENDS FROM 09N79W TO 10N87W TO LOW PRES NEAR 08N93W TO 09N110W. SCATTERED MODERATE CONVECTION IS WITHIN 180 NM EITHER SIDE OF THE TROUGH AXIS BETWEEN 85W AND 110W. ...DISCUSSION... 1026 MB HIGH PRES NW OF THE AREA NEAR 40N144W EXTENDS A RIDGE SE THROUGH 32N132W TO BAJA CALIFORNIA NEAR 27N115W. THE RIDGE WILL SHIFT N AS LOWELL MOVES POLEWARD THE NEXT 2-3 DAYS. THE RIDGE IS MAINTAINING MODERATE WINDS ACROSS THE FORECAST WATERS W OF 110W OUTSIDE OF THE CIRCULATION INFLUENCE OF KARINA AND LOWELL. UPPER LEVEL DIFFLUENCE OVER THE MONSOON TROUGH IS ENHANCING CONVECTIVE ACTIVITY BETWEEN 05N AND 15N E OF 110W. $$ MUNDELL