000 AXPZ20 KNHC 130956 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC FRI JUL 13 2007 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0845 UTC. ...TROPICAL WAVES... TROPICAL WAVE ALONG 85W N OF 3N IS MOVING W 12 KT. SCATTERED MODERATE CONVECTION ALONG THE WAVE AXIS BUT MAINLY OVER LAND. NO ORGANIZATION. TROPICAL WAVE IS ALONG 96W N OF 5N MOVING W AT 10 KT. SCATTERED MODERATE CONVECTION E OF WAVE AXIS BUT NO ORGANIZATION. TROPICAL WAVE IS ALONG 110W N OF 6N MOVING W 10 KT. SCATTERED MODERATE TO STRONG CONVECTION WITHIN 120 NM OF AN APPARENT CENTER OF ROTATION NEAR 12N110W. THE CONVECTION HAS BECOME LESS ORGANIZED DURING THE PAST FEW HRS. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 7N78W 9N84W 7N91W 12N109W 9N140W. CLUSTER OF STRONG CONVECTION WITHIN 75 NM OF 7N79W. SCATTERED MODERATE WITHIN 20 NM OF A LINE FROM 9N85W TO 7N90W TO 8N100W TO 11N105W. SCATTERED MODERATE AND ISOLATED STRONG FROM 8N TO 15N BETWEEN 109W AND 113W AND WITHIN 60 NM OF A LINE FROM 12N116W TO 10N135W. .SCATTERED MODERATE CONVECTION WITHIN 60 NM OF 13N93W AND FROM 23N107W TO 19N110W. ...DISCUSSION... A LARGE UPPER TROUGH DOMINATES THE REGION N OF 25N W OF 125W TONIGHT. A JET IS EVIDENT IN THE WATER VAPOR IMAGERY DIGGING SE INTO THE BASE OF THE TROUGH AND THE TROUGH CONTINUES TO MAKE SLOW MOVEMENT TO THE SE. A PERSISTENT RIDGE IN THE MID LEVELS CONTINUES OVER NRN MEXICO AND THE SW CONUS. AN INVERTED TROUGH WAS ALONG 112W EMBEDDED IN THE RIDGE AND MOVING SLOWLY W. THIS SYSTEM IS PRODUCING SCATTERED CONVECTION ALONG THE WRN MEXICAN COAST. MID LEVEL EASTERLIES WERE EVIDENT S OF 15N AND A WEAK DISTURBANCE WAS LOCATED ALONG 132W MOVING SLOWLY WWD. ON THE SURFACE TONIGHT MOST TRPL WAVES WERE ALONG THE ITCZ. ONE HAS SPAWNED A WEAK LOW CENTER NEAR 12N110W MOVING WWD ABOUT 10 KT. THE PACIFIC RIDGE HAS BECOME QUITE WEAK UNDER THE UPPER TROUGH AND THUS NE TRADES ARE ALSO WEAK..10 TO 15 KT. WINDS ALONG THE BAJA COAST ARE MOSTLY 10 TO 15 KT N OF 24N ACCORDING TO SSMI AND QUIKSCAT IMAGERY AND IN GOOD AGREEMENT WITH THE GFS MODEL. GAP WINDS W OF NICARAGUA CONTINUE TO BLOW. MICROWAVE IMAGERY SHOWS A SMALL AREA OF 20 KT WINDS. CROSS EQUATORIAL SLY WINDS ARE CONFINED TO AREAS S OF CONVECTIVE ACTIVITY. MICROWAVE IMAGERY SHOWS WINDS TO 20 KT. LATER DAY 1 LITTLE CHANGE WITH THE MAIN PLAYERS IN THE MID LEVELS. THE INVERTED TROUGH EMBEDDED IN THE RIDGE DRIFTS WWD TO 116W WHILE THE WEAKER ONE IN THE EASTERLY FLOW MOVES TO 136W. ON THE SURFACE LATER DAY 1 WEAKENING COLD FRONTS ROTATING ABOUT THE UPPER TROUGH OVER THE NW PORTION OF THE AREA WILL CONTINUE TO PUSH INTO THE REGION THEN DISSIPATE. THE FRONTS MOVE INTO WHATS LEFT OF THE PACIFIC RIDGE. THE RIDGE CENTER IS A 1020 MB HIGH NEAR 30N124W. THE GFS MODEL DOESN'T DO MUCH WITH THE LOW CENTER ASSOCIATED WITH A TRPL WAVE BUT IT STILL HOLDS ON TO IT. SOME DECREASE IN GAP WINDS W OF NICARAGUA..LITTLE CHANGE ELSEWHERE. FOR DAY 2 THE UPPER TROUGH OVER THE NW CORNER OF THE REGION WEAKENS WITH DIMINISHING AFFECT ON THE AREA. THE MID LEVEL RIDGE OVER THE SW CONUS STRENGTHENS AND REMAINS STATIONARY OVER NW MEXICO AND THE SW. THE EMBEDDED INVERTED TROUGH WORKS IT'S WAY W AND NW TO 120W WHILE WEAK MID LEVEL TROUGHS MOVE WWD IN THE TRPL EASTERLY FLOW S OF 15N. ON THE SURFACE DAY 2 WHILE THE PACIFIC RIDGE REMAINS WEAK THE GFS MODEL SHOWS A DUAL CENTERED RIDGE ACROSS 130W AT NEAR 1020 MB. LOW PRES ALONG THE ITCZ WORKS NWD TO 12 TO 13N W OF 110W AND THE GRADIENT TIGHTENS BETWEEN THE TWO SYSTEMS..THUS NE TRADES INCREASE TO 20 KT BETWEEN 10N AND 20N W OF 120W. THE GFS MODEL WANTS TO DEVELOP A LOW ON THE ITCZ NEAR 10N97W BUT WE'LL SEE IF IT ISN'T JUST CONVECTIVE FEEDBACK. CROSS EQUATORIAL SLY WINDS INCREASE S OF 10N W OF 90W TO 20 KT. GAP WINDS DECREASE ACCORDING TO THE GFS MODEL BUT ANY STRENGTHENING OF LOW PRES ON THE ITCZ LIKE THE MODEL FORECASTS COULD ENHANCE ELY WINDS BETWEEN 10N TO 12N W OF NICARAGUA. WINDS ALONG THE BAJA COAST SHOULD REMAIN LIGHT NWLY. $$ RRG