000 AXPZ20 KNHC 280952 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SUN JUL 28 2013 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. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS E TO W ACROSS THE CARIBBEAN FROM THE NW COAST OF COLOMBIA AT 10N75W TO EXTREME NORTHERN PANAMA TO ACROSS COSTA RICA TO THE PACIFIC COAST AT 10N85W...THEN WSW TO AN EMBEDDED 1010 MB LOW PRES AT 08N93W...THEN WESTWARD TO 08N106W THEN NW TO 10N120W AND W TO 10N124W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN INTERTROPICAL CONVERGENCE ZONE WHICH CONTINUES WESTWARD TO 11N138W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED ALONG THE COLOMBIAN COAST WITHIN 30 NM OF 07N78W...WITHIN 90 NM EITHER SIDE OF A LINE FROM 06N87W TO THE LOW PRESSURE AT 09N93W TO 09N117W TO 12N121W TO 14N135W...AND ALSO WITHIN 30 NM EITHER SIDE OF A LINE FROM 10N123W TO 08N130W. ...DISCUSSION... TROPICAL STORM FLOSSIE IS W OF AREA WITH E TO SE WINDS 20 TO 30 KT...SEAS 8 TO 14 FT...CONTINUING ACROSS THE DISCUSSION AREA WATERS FROM 12-25N BETWEEN 136-140W. OVERCAST MULTILAYERED CLOUDS WITH HEAVY SHOWERS ARE ALSO OBSERVED WITHIN ROUGHLY THE SAME AREA. THESE CONDITIONS WILL SHIFT W OF AREA THIS AFTERNOON. REFER TO AWIPS/WMO HEADERS HFOTCMCP1/WTPA21 PHFO FOR ADDITIONAL DETAILS ON TROPICAL CYCLONE FLOSSIE. AN UPPER TROUGH EXTENDS S INTO THE DISCUSSION AREA FROM 32N122W THROUGH AN UPPER CYCLONE AT 18N121W...WITH THE TROUGH CONTINUING S LOSING IDENTITY OVER THE DEEP TROPICS NEAR 09N121W. THIS UPPER TROUGH EFFECTIVELY DIVIDES THE UPPER LEVELS OF THE DISCUSSION AREA. TO THE W OF THIS TROUGH...AN UPPER ANTICYCLONE IS CENTERED AT 21N133W WITH AN UPPER RIDGE EXTENDING W TO A CREST JUST N OF TROPICAL CYCLONE FLOSSIE NEAR 23N142W. UPPER DEBRIS MOISTURE FROM FLOSSIE IS ADVECTED N AND DEFINES THE N PERIPHERY OF THE RIDGE TO ALONG 27N140W TO 28N128W...WITH ADDITIONAL MOISTURE TRAPPED WITH THE ANTICYCLONIC ENVELOPE FROM 15-24N BETWEEN 125- 140W. WEAK UPPER DIFFLUENCE S OF THE RIDGE IS SUPPORTING THE CONVECTION PREVIOUSLY DESCRIBED ALONG THE WESTERN PORTION OF THE MONSOON TROUGH AND ITCZ. A LARGE UPPER ANTICYCLONE IS OVER THE NORTHERN OLD MEXICO WITH ITS ENVELOPE OF ANTICYCLONIC FLOW EXTENDING S OVER THE DISCUSSION AREA TO THE N OF 18N BETWEEN 101-117W. DENSE DEBRIS MOISTURE... FROM PREVIOUS CONVECTION ALONG THE SIERRA MADRE OCCIDENTAL...IS ADVECTED W OFF THE PACIFIC COAST OF MEXICO FROM 18-29N TO ALONG 110W. SOME OF THIS UPPER MOISTURE MAY SPREAD N AND ACROSS THE CONUS DESERT SW ON MON. AN UPPER CYCLONE IS OVER THE ISTHMUS OF TEHUANTEPEC WITH ITS CYCLONIC CIRCULATION TAPPING MONSOON TROUGH DEBRIS MOISTURE AND ADVECTING IT N ACROSS THE PACIFIC TO THE N OF 11N BETWEEN 94-102W...AND ALSO OVER EXTREME SE MEXICO AND GUATEMALA. THIS MOISTURE MAY ENHANCE INLAND CONVECTION LATER TODAY AS IT APPARENTLY CONTRIBUTED TO CONVECTION ON SAT AFTERNOON. BROAD ANTICYCLONIC UPPER FLOW IS NOTED OVER THE DEEP TROPICS TO THE E OF 90W...AND IS SUPPORTING INTENSE CONVECTION...ACCOMPANIED BY FREQUENT LIGHTNING...ALONG THE PACIFIC COAST OF COLOMBIA NEAR 07N77W... AND OVER THE SW CARIBBEAN...WITH THESE STRONG CLUSTERS NOW MOVING OVER NORTHERN COSTA RICA AND SE NICARAGUA. CROSS EQUATORIAL SE AND SW SWELL RESULTING IN COMBINED SEAS OF OF 8 FT CONTINUE ACROSS THE DEEP TROPICS TO THE S OF 07N BETWEEN 98-135W. THE AFFECTED AREA IS FORECAST TO SHIFT N COVERING THE WATERS S OF 12N BETWEEN 80-118W TONIGHT...THEN SUBSIDE BELOW 8 FT BY TUE. LOOKING AHEAD...GUIDANCE IS SUGGESTING A SERIES OF CYCLONIC SWIRLS WILL FORM ALONG THE MONSOON TROUGH OVER THE NEXT FEW DAYS. TWO OF THESE CYCLONIC SWIRLS HAVE BEEN INTRODUCED IN THE TEXT AND GRAPHICS BEGINNING LATE MON. ONE LOW PRESSURE IS FORECAST NEAR 11N103W 1009 MB...AND THE SECOND 1009 MB LOW PRESSURE JUST TO THE W NEAR 11N108W. EXPECT THE GRADIENT TO SUPPORT WINDS OF 20-25 KT...SEAS 7-9 FT...WITHIN 180 NM OF BOTH LOWS...EXCEPT OVER THEIR W QUADRANTS WHERE WINDS WILL BE LIGHT. BY LATE WED THE WESTERN LOW WILL BEGIN TO FILL NEAR 11N119W WHILE THE EASTERN LOW IS STRENGTHENING NEAR 12.5N112.5W...AND FORECAST TO CONTINUE MOVING WNW THROUGH FRI. $$ NELSON