000 AXPZ20 KNHC 171549 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SUN JUL 17 2011 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 1545 UTC. ...TROPICAL LOWS... A 1009 MB SURFACE LOW PRES IS NEAR 10N87W WITH SCATTERED MODERATE ISOLATED STRONG CONVECTION TRYING TO ORGANIZE INTO A BAND WITHIN 60 NM OVER THE W QUADRANT. THIS LOW IS EXPECTED TO MOVE GENERALLY NW REACHING NEAR 10N90W AT SUNRISE MON...AND NEAR 11N95W AT SUNRISE TUE. MODEL GUIDANCE IS VERY AGRESSIVE WITH THIS LOW QUICKLY DEEPENING..THUS FORECAST ASSOCAITED WINDS TO INCREASE TO 20 TO 30 KT WITHIN ABOUT 240 NM OF CENTER BY EARLY TUE. IF CONVECTION ORGANIZES INTO A PERSISTENT BAND...THE MENTION OF POSSIBLE TROPICAL CYCLONE FORMATION WILL BE ADDED TO ALPHANUMERIC AND GRAPHICAL PRODUCTS. A 1004 MB SURFACE LOW IS NEAR 16N107W AND HAS BEEN MOVING S OVER THE PAST 24 HOURS. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS CURRENTLY TRYING TO BAND WITHIN 90 NM OVER THE W SEMICIRCLE. THIS LOW IS EXPECTED TO MOVE W TO NEAR 16N108W EARLY MON AND NEAR 17N111W EARLY TUE. AS THE LOW MOVES WEATWARD IT WILL ENCOUNTER INCREASING COLDER SEAS SURFACE WATER SO ITS ENVELOPE OF TIME FOR DEVELOPMENT IS LIMITED. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS E TO W ACROSS THE SW CARIBBEAN AND PANAMA ALONG 09N...THEN TURNS NW INTO THE 1009 MB SURFACE LOW AT 10N87W. THE MONSOON TROUGH AXIS THEN EXTENDS NW OVER THE EXTREME E PACIFIC WATERS PARALLEL TO THE CENTRAL AMERICAN COAST TO OVER MEXICO AT 18N100W...THEN TURNS SW INTO THE 1004 MB SURFACE LOW ESTIMATED AT 16N107W. THE MONSOON TROUGH AXIS THEN CONTINUES SW PASSING THROUGH 11N120W TO 08N135W WHERE LOW LEVEL WINDS INDICATE THE AXIS OF THE INTERTROPICAL CONVERGENCE ZONE BEGINS...AND CONTINUES SW TO BEYOND 08N140W. OVERCAST LOW AND MID LEVELS CLOUDS ARE OBSERVED N OF THE EQUATOR TO THE E OF 90W AND CONTINUE NW OF A LINE FROM THE 00N90W 17N110W. EMBEDDED SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS NOTED ALONG THE COAST OF COLOMBIA WITHIN 150 NM OF 07N78W...AND ALSO WITHIN 180 NM EITHER SIDE OF A LINE FROM 06N85W TO 15N98W SURROUNDING THE LOW PRES AT 10N87W. SIMILIAR CONVECTION IS ALSO NOTED WITHIN 60 NM EITHER SIDE OF A LINE FROM 12N100W TO 11N110W AND BECOMING ISOLATED WITHIN 60 NM EITHER SIDE OF A LINE FROM 11N124W TO 09N130W ALONG THE W SEGMETNT OF THE MONSOON TROUGH AXIS. ISOLATED MODERATE AND STRONG CONVECTION IS ALSO NOTED WITHIN 150 NM OF COAST OF MEXICO FROM 93W TO 99W. ...DISCUSSION... A LONG WAVE TROUGH IS ANCHORED ALONG THE W COAST OF N AMERICA WITH ITS MEAN AXIS CONTINUING S INTO THE DISCUSSION AREA ALONG 32N125W TO A BASE AT 17N136W. AN EMBEDDED SHORTWAVE TROUGH IS NOTED FROM SW CALIFORNIA TO 21N133W TO 14N138W AND IS ACCOMPANIED BY UPPER MOISTURE WHICH IS SPREADING E OVER CENTRAL CALIFORNIA AND AS FAR S AS 31N130W. OTHERWISE THE UPPER LEVELS ARE VERY DRY TO THE N OF 14N W OF 116W...AND OVER THE NW BAJA CALIFORNIA PENINSULA. A LONG WAVE UPPER RIDGE CONTINUES TO DOMINATE CENTRAL N AMERICA ORIGINATING FROM AN ANTICYCLONE MEANDERING OVER OKLAHOMA. AN ASSOCIATED RIDGE EXTENDS SW ACROSS NW OLD MEXICO TO A CREST OVER THE PACIFIC NEAR 23N117W. THIS RIDGE WILL CONTINUE TO BLOCK THE FORWARD ADVANCE OF THE PREVIOUSLY DESCRIBED UPPER TROUGHS THROUGH AT LEAST MON NIGHT. THEREAFTER A STRONG SHORTWAVE TROUGH IS EXPECTED TO MOVE THE LONGWAVE AXIS OVER THE W CONUS BY EARLY TUE AS THE ANTICYCLONE SHIFTS E TO OVER ARKANSAS. AN EMBEDDED UPPER CYCLONE IS SHIFTING W ACROSS CENTRAL OLD MEXICO NEAR 26N105W AND IS TRAILED BY A SHORTWAVE ANTICYCLONE OVER THE SW GULF OF MEXICO. THIS RESULTS IN AN AREA OF UPPER DIFFLUENCE OVER CENTRAL OLD MEXICO. A CLUSTER OF INTENSE CONVECTION FLARED OVER THE BAY OF CAMPECHE LAST NIGHT WITH THE REMNANTS NOW CENTERED ON 21N98W. UPPER DIFFLUENCE IS ALSO SUPPORTING THE CONVECTION PREVIOUSLY DESCRIBED NEAR THE SURFACE LOW AT 16N107W. AN UPPER LEVEL TROUGH EXTENDS WSW ACROSS THE CARIBBEAN FROM PUERTO RICO TO AN UPPER CYCLONE AT 12N78W. AN UPPER RIDGE EXTENDS SW FROM NW VENEZUELA TO A CREST ALONG THE PACIFIC COAST OF COLOMBIA. AN TROPICAL UPPER ANTICYLONE IS CENTERED NEAR 05N126W WITH A RIDGE EXTENDING E...ROUGHLY OVER THE LOWER LEVEL MONSOON TROUGH AXIS...TO A CREST AT 08N105W. THUS...THE UPPER LEVELS OF THE DEEP TROPICS IS SOMEWHAT DIFFLUENT OVER MOST OF CENTRAL AMERICA...AND OVER THE TROPICAL PACIFIC E OF 110W. CONVECTION CONTINUES TO FLARE ALONG THE W COAST OF CENTRAL AMERICA DURING NIGHT HOURS AND SHIFTS W OVER THE PACIFIC DURING DAYLIGHT. THE ASSOCIATED DENSE DEBRIS MOISTURE COVERS THE PACIFIC E OF 110W. THE DEBRIS MOISTURE FROM THE THIN LINE OF CONVECTION ALONG THE W SEGMENT OF THE MONSOON TROUGH FANS OUT ONLY A FEW MILES FROM THE DECAYING CLUSTERS BEFORE EVAPORATING IN THE DRY AIR ALOFT OVER THE TROPICS W OF 120W. WIDESPREAD RAINFALL...WITH LOCALIZED TRAINING DEEP CONVECTION...IS EXPECTED TO CONTINUE TO DEVELOP ALONG THE W COAST OF CENTRAL AMERICA DURING THE DAY OR SO. THIS MAY RESULT IN FLASH FLOODS AND MUDSLIDES THROUGH THE WEEKEND. A GRAPHICAL REPRESENTATION IS PRESENTED AT HTTP://WWW.HURRICANES.GOV/MARINE. ELSEWHERE AT THE SURFACE...NW FLOW WILL CONTINUE TO PULSE AT 15-20 KT ALONG THE W COAST OF BAJA CALIFORNIA PENINSULA THROUGH TONIGHT THEN DIMINISH. REINFORCING SW SWELL IS CROSSING THE EQUATOR BETWEEN 92W AND 122W. SOUTHWESTERLY MONSOONAL WINDS ARE EXPECTED TO DIMINISH SOME AS THE SURFACE LOWS MOVE GENERALLY WESTWARD. $$ NELSON 000 AXPZ20 KNHC 171549 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SUN JUL 17 2011 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 1545 UTC. ...TROPICAL LOWS... A 1009 MB SURFACE LOW PRES IS NEAR 10N87W WITH SCATTERED MODERATE ISOLATED STRONG CONVECTION TRYING TO ORGANIZE INTO A BAND WITHIN 60 NM OVER THE W QUADRANT. THIS LOW IS EXPECTED TO MOVE GENERALLY NW REACHING NEAR 10N90W AT SUNRISE MON...AND NEAR 11N95W AT SUNRISE TUE. MODEL GUIDANCE IS VERY AGRESSIVE WITH THIS LOW QUICKLY DEEPENING..THUS FORECAST ASSOCAITED WINDS TO INCREASE TO 20 TO 30 KT WITHIN ABOUT 240 NM OF CENTER BY EARLY TUE. IF CONVECTION ORGANIZES INTO A PERSISTENT BAND...THE MENTION OF POSSIBLE TROPICAL CYCLONE FORMATION WILL BE ADDED TO ALPHANUMERIC AND GRAPHICAL PRODUCTS. A 1004 MB SURFACE LOW IS NEAR 16N107W AND HAS BEEN MOVING S OVER THE PAST 24 HOURS. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS CURRENTLY TRYING TO BAND WITHIN 90 NM OVER THE W SEMICIRCLE. THIS LOW IS EXPECTED TO MOVE W TO NEAR 16N108W EARLY MON AND NEAR 17N111W EARLY TUE. AS THE LOW MOVES WEATWARD IT WILL ENCOUNTER INCREASING COLDER SEAS SURFACE WATER SO ITS ENVELOPE OF TIME FOR DEVELOPMENT IS LIMITED. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS E TO W ACROSS THE SW CARIBBEAN AND PANAMA ALONG 09N...THEN TURNS NW INTO THE 1009 MB SURFACE LOW AT 10N87W. THE MONSOON TROUGH AXIS THEN EXTENDS NW OVER THE EXTREME E PACIFIC WATERS PARALLEL TO THE CENTRAL AMERICAN COAST TO OVER MEXICO AT 18N100W...THEN TURNS SW INTO THE 1004 MB SURFACE LOW ESTIMATED AT 16N107W. THE MONSOON TROUGH AXIS THEN CONTINUES SW PASSING THROUGH 11N120W TO 08N135W WHERE LOW LEVEL WINDS INDICATE THE AXIS OF THE INTERTROPICAL CONVERGENCE ZONE BEGINS...AND CONTINUES SW TO BEYOND 08N140W. OVERCAST LOW AND MID LEVELS CLOUDS ARE OBSERVED N OF THE EQUATOR TO THE E OF 90W AND CONTINUE NW OF A LINE FROM THE 00N90W 17N110W. EMBEDDED SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS NOTED ALONG THE COAST OF COLOMBIA WITHIN 150 NM OF 07N78W...AND ALSO WITHIN 180 NM EITHER SIDE OF A LINE FROM 06N85W TO 15N98W SURROUNDING THE LOW PRES AT 10N87W. SIMILIAR CONVECTION IS ALSO NOTED WITHIN 60 NM EITHER SIDE OF A LINE FROM 12N100W TO 11N110W AND BECOMING ISOLATED WITHIN 60 NM EITHER SIDE OF A LINE FROM 11N124W TO 09N130W ALONG THE W SEGMETNT OF THE MONSOON TROUGH AXIS. ISOLATED MODERATE AND STRONG CONVECTION IS ALSO NOTED WITHIN 150 NM OF COAST OF MEXICO FROM 93W TO 99W. ...DISCUSSION... A LONG WAVE TROUGH IS ANCHORED ALONG THE W COAST OF N AMERICA WITH ITS MEAN AXIS CONTINUING S INTO THE DISCUSSION AREA ALONG 32N125W TO A BASE AT 17N136W. AN EMBEDDED SHORTWAVE TROUGH IS NOTED FROM SW CALIFORNIA TO 21N133W TO 14N138W AND IS ACCOMPANIED BY UPPER MOISTURE WHICH IS SPREADING E OVER CENTRAL CALIFORNIA AND AS FAR S AS 31N130W. OTHERWISE THE UPPER LEVELS ARE VERY DRY TO THE N OF 14N W OF 116W...AND OVER THE NW BAJA CALIFORNIA PENINSULA. A LONG WAVE UPPER RIDGE CONTINUES TO DOMINATE CENTRAL N AMERICA ORIGINATING FROM AN ANTICYCLONE MEANDERING OVER OKLAHOMA. AN ASSOCIATED RIDGE EXTENDS SW ACROSS NW OLD MEXICO TO A CREST OVER THE PACIFIC NEAR 23N117W. THIS RIDGE WILL CONTINUE TO BLOCK THE FORWARD ADVANCE OF THE PREVIOUSLY DESCRIBED UPPER TROUGHS THROUGH AT LEAST MON NIGHT. THEREAFTER A STRONG SHORTWAVE TROUGH IS EXPECTED TO MOVE THE LONGWAVE AXIS OVER THE W CONUS BY EARLY TUE AS THE ANTICYCLONE SHIFTS E TO OVER ARKANSAS. AN EMBEDDED UPPER CYCLONE IS SHIFTING W ACROSS CENTRAL OLD MEXICO NEAR 26N105W AND IS TRAILED BY A SHORTWAVE ANTICYCLONE OVER THE SW GULF OF MEXICO. THIS RESULTS IN AN AREA OF UPPER DIFFLUENCE OVER CENTRAL OLD MEXICO. A CLUSTER OF INTENSE CONVECTION FLARED OVER THE BAY OF CAMPECHE LAST NIGHT WITH THE REMNANTS NOW CENTERED ON 21N98W. UPPER DIFFLUENCE IS ALSO SUPPORTING THE CONVECTION PREVIOUSLY DESCRIBED NEAR THE SURFACE LOW AT 16N107W. AN UPPER LEVEL TROUGH EXTENDS WSW ACROSS THE CARIBBEAN FROM PUERTO RICO TO AN UPPER CYCLONE AT 12N78W. AN UPPER RIDGE EXTENDS SW FROM NW VENEZUELA TO A CREST ALONG THE PACIFIC COAST OF COLOMBIA. AN TROPICAL UPPER ANTICYLONE IS CENTERED NEAR 05N126W WITH A RIDGE EXTENDING E...ROUGHLY OVER THE LOWER LEVEL MONSOON TROUGH AXIS...TO A CREST AT 08N105W. THUS...THE UPPER LEVELS OF THE DEEP TROPICS IS SOMEWHAT DIFFLUENT OVER MOST OF CENTRAL AMERICA...AND OVER THE TROPICAL PACIFIC E OF 110W. CONVECTION CONTINUES TO FLARE ALONG THE W COAST OF CENTRAL AMERICA DURING NIGHT HOURS AND SHIFTS W OVER THE PACIFIC DURING DAYLIGHT. THE ASSOCIATED DENSE DEBRIS MOISTURE COVERS THE PACIFIC E OF 110W. THE DEBRIS MOISTURE FROM THE THIN LINE OF CONVECTION ALONG THE W SEGMENT OF THE MONSOON TROUGH FANS OUT ONLY A FEW MILES FROM THE DECAYING CLUSTERS BEFORE EVAPORATING IN THE DRY AIR ALOFT OVER THE TROPICS W OF 120W. WIDESPREAD RAINFALL...WITH LOCALIZED TRAINING DEEP CONVECTION...IS EXPECTED TO CONTINUE TO DEVELOP ALONG THE W COAST OF CENTRAL AMERICA DURING THE DAY OR SO. THIS MAY RESULT IN FLASH FLOODS AND MUDSLIDES THROUGH THE WEEKEND. A GRAPHICAL REPRESENTATION IS PRESENTED AT HTTP://WWW.HURRICANES.GOV/MARINE. ELSEWHERE AT THE SURFACE...NW FLOW WILL CONTINUE TO PULSE AT 15-20 KT ALONG THE W COAST OF BAJA CALIFORNIA PENINSULA THROUGH TONIGHT THEN DIMINISH. REINFORCING SW SWELL IS CROSSING THE EQUATOR BETWEEN 92W AND 122W. SOUTHWESTERLY MONSOONAL WINDS ARE EXPECTED TO DIMINISH SOME AS THE SURFACE LOWS MOVE GENERALLY WESTWARD. $$ NELSON