000 AXPZ20 KNHC 261004 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SUN JUN 26 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0900 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH IS ALONG 09N84W TO LOW PRES NEAR 13N91W 1009 MB TO 11N105W TO 10N122W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 10N122W TO 08N130W TO 05N140W. NUMEROUS MODERATE TO STRONG CONVECTION IS WITHIN 30 NM E AND 60 NM W SEMICIRCLES OF THE LOW. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 240 NM S OF THE MONSOON TROUGH BETWEEN 100W AND 106W. ...DISCUSSION... THE MAJORITY OF THE DISCUSSION AREA CONTINUES TO BE DOMINATED BY UPPER ANTICYCLONIC FLOW...ANCHORED BY TWO ANTICYCLONES...ONE OVER THE RIO GRANDE VALLEY NEAR THE TEXAS AND MEXICO BORDER NEAR 29N103W AND THE OTHER JUST S OF THE SOUTHERN TIP OF THE BAJA CALIFORNIA PENINSULA NEAR 20N110W. AN ASSOCIATED UPPER RIDGE EXTENDS SW TO 11N140W. SATELLITE WATER VAPOR IMAGERY SHOWS EXTENSIVE MODERATE TO STRONG SUBSIDENCE OVER THE AREA NW OF THE RIDGE AXIS AS DEPICTED BY THE FIELD OF BROKEN STRATOCUMULUS CLOUDS MOVING SOUTHWESTWARD OVER THE SW PERIPHERY OF THE ANTICYCLONIC FLOW. AN ELONGATED UPPER LEVEL LOW NEAR THE NW PORTION OF THE DISCUSSION AREA POSITIONED OVER 31N143W EXTENDS A TROUGH SE AND S ALONG 140W. THIS FEATURE WILL RETREAT WESTWARD OVER THE NEXT 24 TO 48 HOURS AS A VIGOROUS UPPER LEVEL LOW DIVES SOUTHEASTWARD TOWARDS NORTHERN CALIFORNIA. MODEL GUIDANCE NOW CARRIES AN ASSOCIATED UPPER TROUGH THROUGH THE FAR NORTHERN PORTION OF THE AREA AS THE UPCOMING UPPER LOW TRANSLATES TOWARD CALIFORNIA...WITH AN ATTENDANT SURFACE TROUGH ALSO SKIRTING THROUGH THE NORTHERN WATERS. OTHER THAN A WIND SHIFT...DO NOT EXPECT SIGNIFICANT WINDS OR SEAS BEHIND THIS SURFACE TROUGH. UPPER LEVEL EASTERLY FLOW ALONG THE SOUTHERN PERIPHERY OF THE ANTICYCLONE CONTINUES TO TRANSPORT UPPER LEVEL MOISTURE AND DEBRIS CLOUDS FROM CONVECTION THAT HAD DEVELOPED OVER INTERIOR CENTRAL MEXICO YESTERDAY AFTERNOON AND EVENING...WITH ADDITIONAL STRONGER CONVECTION RELATED TO THE MONSOON TROUGH AS DESCRIBED ABOVE ALSO MOVING WESTWARD. NEWER CONVECTION IS CURRENTLY DEVELOPING OVER THE INTERIOR PORTIONS OF MUCH OF CENTRAL AMERICA AS IT IS BEING ENHANCED BY UPPER DIVERGENCE IN THE AREA...ALONG WITH ENHANCED ATMOSPHERIC INSTABILITY FROM THE SOUTHERN SEGMENT OF A TROPICAL WAVE MOVING ACROSS THE YUCATAN PENINSULA TOWARD THE SW GULF OF MEXICO. THIS WAVE IS HELPING TO ENHANCE ABUNDANT DEEP LEVEL MOISTURE WHICH IS ALSO HELPING TO SUSTAIN THE CONVECTION. EXPECT VERY HEAVY RAINFALL AND GUSTY WINDS WITH THIS PERSISTENT CONVECTION DURING THE NEXT COUPLE OF DAYS. A WEAK 1009 MB SURFACE LOW ALONG THE MONSOON TROUGH IS NEAR 13N91W MOVING SLOWLY NW...BUT WITH MOST OF THE LOW LEVEL VORTICITY EXPECTED TO STAY TO THE N AND NE OF THE AREA OVER CENTRAL AMERICA AND THE SW GULF OF MEXICO...ALONG WITH INCREASING UPPER LEVEL NE WINDS DURING THE NEXT 24 TO 48 HOURS ...NO SIGNIFICANT DEVELOPMENT OF THIS LOW IS EXPECTED PRIOR TO ITS DISSIPATION. ELSEWHERE AT THE SURFACE...A BROAD RIDGE COVERS THE AREA GENERALLY TO THE N OF 13N AND W OF 117W. RECENT WINDSAT AND ASCAT SCATTEROMETER DATA CAPTURED A SMALL AREA OF NW TO N 20 KT WINDS N OF 29N BETWEEN 119W AND 122W... ALONG WITH 8 FT SEAS IN MIXED SW AND NW SWELL ACROSS THE REMAINDER OF THE AREA N OF 28N BETWEEN 118W AND 126W. THESE WINDS AND SEAS ARE FORECAST TO DIMINISH AND SUBSIDE WITHIN THE NEXT 24 HOURS. PERSISTENT SOUTHERLY FLOW FEEDING IN TO THE MONSOON TROUGH CONSISTS OF 20 KT S TO SW WINDS AND SEAS TO 9 FT WITHIN 240 NM S OF A LINE FROM 12N89W TO 08N104W...ALONG WITH AN AREA OF 8 TO 9 FT CROSS-EQUATORIAL SW SWELL SURROUNDING THIS AREA. THESE WINDS ARE FORECAST TO DIMINISH WITHIN THE NEXT 24 TO 36 HOURS WHILE SEAS WILL GRADUALLY DECAY TO BARELY 8 FT BY 48 HOURS. $$ LEWITSKY 000 AXPZ20 KNHC 261004 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SUN JUN 26 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0900 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH IS ALONG 09N84W TO LOW PRES NEAR 13N91W 1009 MB TO 11N105W TO 10N122W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 10N122W TO 08N130W TO 05N140W. NUMEROUS MODERATE TO STRONG CONVECTION IS WITHIN 30 NM E AND 60 NM W SEMICIRCLES OF THE LOW. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 240 NM S OF THE MONSOON TROUGH BETWEEN 100W AND 106W. ...DISCUSSION... THE MAJORITY OF THE DISCUSSION AREA CONTINUES TO BE DOMINATED BY UPPER ANTICYCLONIC FLOW...ANCHORED BY TWO ANTICYCLONES...ONE OVER THE RIO GRANDE VALLEY NEAR THE TEXAS AND MEXICO BORDER NEAR 29N103W AND THE OTHER JUST S OF THE SOUTHERN TIP OF THE BAJA CALIFORNIA PENINSULA NEAR 20N110W. AN ASSOCIATED UPPER RIDGE EXTENDS SW TO 11N140W. SATELLITE WATER VAPOR IMAGERY SHOWS EXTENSIVE MODERATE TO STRONG SUBSIDENCE OVER THE AREA NW OF THE RIDGE AXIS AS DEPICTED BY THE FIELD OF BROKEN STRATOCUMULUS CLOUDS MOVING SOUTHWESTWARD OVER THE SW PERIPHERY OF THE ANTICYCLONIC FLOW. AN ELONGATED UPPER LEVEL LOW NEAR THE NW PORTION OF THE DISCUSSION AREA POSITIONED OVER 31N143W EXTENDS A TROUGH SE AND S ALONG 140W. THIS FEATURE WILL RETREAT WESTWARD OVER THE NEXT 24 TO 48 HOURS AS A VIGOROUS UPPER LEVEL LOW DIVES SOUTHEASTWARD TOWARDS NORTHERN CALIFORNIA. MODEL GUIDANCE NOW CARRIES AN ASSOCIATED UPPER TROUGH THROUGH THE FAR NORTHERN PORTION OF THE AREA AS THE UPCOMING UPPER LOW TRANSLATES TOWARD CALIFORNIA...WITH AN ATTENDANT SURFACE TROUGH ALSO SKIRTING THROUGH THE NORTHERN WATERS. OTHER THAN A WIND SHIFT...DO NOT EXPECT SIGNIFICANT WINDS OR SEAS BEHIND THIS SURFACE TROUGH. UPPER LEVEL EASTERLY FLOW ALONG THE SOUTHERN PERIPHERY OF THE ANTICYCLONE CONTINUES TO TRANSPORT UPPER LEVEL MOISTURE AND DEBRIS CLOUDS FROM CONVECTION THAT HAD DEVELOPED OVER INTERIOR CENTRAL MEXICO YESTERDAY AFTERNOON AND EVENING...WITH ADDITIONAL STRONGER CONVECTION RELATED TO THE MONSOON TROUGH AS DESCRIBED ABOVE ALSO MOVING WESTWARD. NEWER CONVECTION IS CURRENTLY DEVELOPING OVER THE INTERIOR PORTIONS OF MUCH OF CENTRAL AMERICA AS IT IS BEING ENHANCED BY UPPER DIVERGENCE IN THE AREA...ALONG WITH ENHANCED ATMOSPHERIC INSTABILITY FROM THE SOUTHERN SEGMENT OF A TROPICAL WAVE MOVING ACROSS THE YUCATAN PENINSULA TOWARD THE SW GULF OF MEXICO. THIS WAVE IS HELPING TO ENHANCE ABUNDANT DEEP LEVEL MOISTURE WHICH IS ALSO HELPING TO SUSTAIN THE CONVECTION. EXPECT VERY HEAVY RAINFALL AND GUSTY WINDS WITH THIS PERSISTENT CONVECTION DURING THE NEXT COUPLE OF DAYS. A WEAK 1009 MB SURFACE LOW ALONG THE MONSOON TROUGH IS NEAR 13N91W MOVING SLOWLY NW...BUT WITH MOST OF THE LOW LEVEL VORTICITY EXPECTED TO STAY TO THE N AND NE OF THE AREA OVER CENTRAL AMERICA AND THE SW GULF OF MEXICO...ALONG WITH INCREASING UPPER LEVEL NE WINDS DURING THE NEXT 24 TO 48 HOURS ...NO SIGNIFICANT DEVELOPMENT OF THIS LOW IS EXPECTED PRIOR TO ITS DISSIPATION. ELSEWHERE AT THE SURFACE...A BROAD RIDGE COVERS THE AREA GENERALLY TO THE N OF 13N AND W OF 117W. RECENT WINDSAT AND ASCAT SCATTEROMETER DATA CAPTURED A SMALL AREA OF NW TO N 20 KT WINDS N OF 29N BETWEEN 119W AND 122W... ALONG WITH 8 FT SEAS IN MIXED SW AND NW SWELL ACROSS THE REMAINDER OF THE AREA N OF 28N BETWEEN 118W AND 126W. THESE WINDS AND SEAS ARE FORECAST TO DIMINISH AND SUBSIDE WITHIN THE NEXT 24 HOURS. PERSISTENT SOUTHERLY FLOW FEEDING IN TO THE MONSOON TROUGH CONSISTS OF 20 KT S TO SW WINDS AND SEAS TO 9 FT WITHIN 240 NM S OF A LINE FROM 12N89W TO 08N104W...ALONG WITH AN AREA OF 8 TO 9 FT CROSS-EQUATORIAL SW SWELL SURROUNDING THIS AREA. THESE WINDS ARE FORECAST TO DIMINISH WITHIN THE NEXT 24 TO 36 HOURS WHILE SEAS WILL GRADUALLY DECAY TO BARELY 8 FT BY 48 HOURS. $$ LEWITSKY