000 AXPZ20 KNHC 200239 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 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 0215 UTC. ...SPECIAL FEATURES... TROPICAL STORM KARINA CENTERED NEAR 15.9N 135.3W...OR 1151 NM E OF HILO HAWAII AT 20/0300 UTC MOVING W OR 275 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 90 NM IN THE N...AND 120 NM IN THE S AND W QUADRANTS. A CONTINUED DECREASE IN FORWARD SPEED IS EXPECTED AND KARINA COULD BECOME NEARLY STATIONARY BY WED NIGHT WITH LITTLE CHANGE IN STRENGTH. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. TROPICAL STORM LOWELL NEAR NEAR 18.7N 120.7W...OR 656 NM WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA AT 20/0300 UTC MOVING NW OR 315 DEG AT 6 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 996 MB. MAXIMUM SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 210 NM IN THE E SEMICIRCLE...240 NM IN THE SW...AND 90 NM IN THE NW QUADRANTS. SCATTERED MODERATE CONVECTION IS BETWEEN 150 AND 240 NM IN THE E QUADRANT...AND ELSEWHERE BETWEEN 240 AND 420 NM IN THE SE QUADRANT. A DECREASE IN FORWARD SPEED IS EXPECTED TONIGHT AND WED...FOLLOWED BY A TURN TOWARD THE NNW WED NIGHT WITH LITTLE CHANGE IN STRENGTH. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS. WEAK LOW PRES IS FORMING NEAR 08N93W ALONG THE SOUTHERN PORTION OF A TROPICAL WAVE WHICH EXTENDS ALONG 93W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 240 NM IN THE S SEMICIRCLE AND ELSEWHERE WITHIN 300 NM IN THE W QUADRANT. CURRENTLY ASSOCIATED WINDS AND SEAS ARE 20 KT OR LESS AND LESS THAN 8 FT...HOWEVER WINDS ARE FORECAST TO INCREASE TO FRESH TO STRONG IN THE GULF OF PAPAGAYO TONIGHT WHICH WILL FEED INTO THE LOW CIRCULATION WITH THE WINDS EXPANDING AND SPREADING WESTWARD AROUND THE LOW AS IT CONTINUES WESTWARD. THIS LOW HAS A MEDIUM FORMATION CHANCE FOR TROPICAL CYCLONE DEVELOPMENT DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... A TROPICAL WAVE EXTENDS FROM LOW PRES NEAR 08N93W TO NEAR THE GUATEMALA/MEXICO BORDER CONTINUING NORTHWARD INTO THE EXTREME EASTERN BAY OF CAMPECHE MOVING W AT 15-20 KT. SEE THE DISCUSSION ABOUT THE LOW ABOVE FOR MORE DETAILS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 06N77W TO LOW PRES NEAR 08N93W TO 12N112W. NO ITCZ AXIS IS E OF 140W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 120 NM S OF THE AXIS BETWEEN 82W AND 90W...FROM 05N TO 10N BETWEEN 100W AND 104W... FROM 09N TO 12N BETWEEN 105W AND 110W...FROM 12N TO 16N BETWEEN 103W AND 106W...AND FROM 15N TO 18N BETWEEN 108W AND 110W. SCATTERED MODERATE CONVECTION IS FROM 07N TO 10N W OF 136W. ...DISCUSSION... 1026 MB HIGH PRES IS NW OF THE DISCUSSION WATERS NEAR 41N145W EXTENDING A RIDGE SE THROUGH 32N132W TO CENTRAL BAJA CALIFORNIA NEAR 27N115W. THIS RIDGE WILL SHIFT TO THE N AS LOWELL MOVES IN A GENERAL NORTHWARD DIRECTION. THIS RIDGE IS MAINTAINING MODERATE WINDS ACROSS THE FORECAST WATERS W OF 110W OUTSIDE OF THE INFLUENCES OF KARINA AND LOWELL. ELSEWHERE E OF 110W...UPPER LEVEL DIFFLUENCE OVER THE SW CARIBBEAN SEA AND W OF COLOMBIA IN THE NE PACIFIC IS HELPING TO SUPPORT SCATTERED MODERATE TO STRONG CONVECTION ACROSS PANAMA AND GUATEMALA AIDED BY DAYTIME HEATING. $$ LEWITSKY