000 AXPZ20 KNHC 152206 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SAT SEP 15 2012 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2145 UTC. ...SPECIAL FEATURES... TROPICAL STORM KRISTY CENTERED NEAR 23.2N 115.6W AT 2100 UTC MOVING NW OR 315 DEG AT 8 KT. MAXIMUM SUSTAINED WINDS ARE 40 KT WITH GUSTS TO 50 KT AND MINIMUM PRESSURE OF 1002 MB. KRISTY HAS REGAINED IMPROVEMENT WITH ITS OVERALL CLOUD PATTERN BECOMING MORE SYMMETRICAL AS SEEN ON SATELLITE IMAGERY. BANDING FEATURES APPEAR MORE WRAPPED INTO THE CENTER THAN 24 HOURS AGO. SCATTERED MODERATE CONVECTION IS WITHIN 150 NM OF THE CENTER IN THE NE SEMICIRCLE...AND 45 NM FROM THE CENTER IN SW SEMICIRCLE. KRISTY IS FORECAST TO TRACK IN A GENERAL NW DIRECTION OVER COOLER SEA SURFACE TEMPERATURES AND IS EXPECTED TO WEAKEN TO A REMNANT LOW PRESSURE NEAR 25N118W ON SUN. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. TROPICAL STORM LANE CENTERED NEAR 12.9N 123.7W AT 2100 UTC MOVING WSW OR 245 DEG AT 4 KT. MAXIMUM SUSTAINED WINDS ARE 35 KT WITH GUSTS TO 45 KT AND A MINIMUM PRESSURE OF 1003 MB. LANE HAS CONTINUED TO BECOME BETTER ORGANIZED DURING THE DAY AS NOTED IN ITS IMPROVED BANDING FEATURES TIGHTLY WRAPPED AROUND THE CENTER...WHICH APPEARS TO UNDER A CENTRAL DENSE OVERCAST TYPE FEATURE. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM OF THE CENTER IN THE SE QUADRANT...WITHIN 240 NM OF THE CENTER IN THE SW AND WITHIN 150 NM NW OF THE CENTER IN THE NW QUADRANT. LANE IS FORECAST TO SLOWLY INTENSIFY AS IT TRACKS NW OVER THE NEXT 48 HRS. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS W FROM THE SOUTHERN COAST OF COSTA RICA TO 08N100W AND TO 12N117W WHERE IT ENDS. IT RESUMES AT LOW NEAR PRES NEAR 13N134W AND CONTINUES TO 11N140W WHERE IT TRANSITIONS TO THE ITCZ W OF THE AREA. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 30 NM OF THE MONSOON TROUGH BETWEEN 93W AND 105W. SCATTERED STRONG CONVECTION IS WITHIN 120 NM S OF THE MONSOON TROUGH BETWEEN 110W-114W. SCATTERED MODERATE CONVECTION EXISTS FROM 07N TO 10N BETWEEN 120W AND 127W. ...DISCUSSION... A LONGWAVE UPPER RIDGE DOMINATES THE EASTERN N PACIFIC EXTENDING FROM AN UPPER ANTICYCLONE CENTERED AT 26N124W AND RIDGING NE TO BEYOND 32N121W. AN UPPER RIDGE ALSO EXTENDS SW TO A CREST AT 12N145W. A DEEP LAYER TROUGH IS OVER THE NW PORTION OF THE AREA WITH AN EMBEDDED ELONGATED UPPER CYCLONE AT 31N140W. WEAK UPPER DIFFLUENCE OVER THE DEEP TROPICS IS ENHANCING CONVECTION ALONG THE MONSOON TROUGH BETWEEN 120W AND 140W...INCLUDING THE CONVECTION ASSOCIATED WITH LANE. SOME OF THE DEBRIS MOISTURE IS ADVECTED SW TO ALONG 04N BETWEEN 120W AND 130W...AND SOME OF THE DEBRIS MOISTURE IS ALSO ADVECTED N ACROSS THE UPPER RIDGE AXIS BETWEEN 130W AND 140W...THEN THE NARROW PLUME OF MOISTURE TURNS NE TO NEAR 22N131W WHERE IT EVAPORATES IN THE VERY DRY THAT IS INDICATED OVER THE DISCUSSION AREA N OF 17N BETWEEN 117W AND 140W. THE UPPER ANTICYCLONE IS EXPECTED TO SHIFT NE TO NEAR 28N120W LATE SUN AS THE UPPER CYCLONE ALSO SHIFTS N TO NEAR 35N140W DRAGGING AN UPPER TROUGH OVER THE EXTREME NW PORTION OF THE DISCUSSION AREA. IMMEDIATELY TO THE E OF THE LARGE UPPER RIDGE IS A DEEP LAYERED CYCLONE OVER NEW MEXICO WITH AN UPPER TROUGH EXTENDING SW ACROSS THE CENTRAL BAJA PENINSULA INTO AN UPPER CYCLONE NEAR TROPICAL CYCLONE KRISTY...WITH THE UPPER TROUGH CONTINUING S TO NEAR 08N119W. UPPER DIFFLUENCE ALONG AND E OF THIS TROUGH HAS ENHANCED CONVECTION OVER INTERIOR NORTHWESTERN OLD MEXICO... OVER TROPICAL CYCLONE KRISTY...AND ALSO SEEMS TO A CONTRIBUTOR TO CONVECTION IN THE DEEP TROPICS BETWEEN 110W-118W. THE RESULTANT DEBRIS MOISTURE TO THE N OF 25N IS SPREADING NE OVER THE NORTHWESTERN MEXICO AND THEN WELL INLAND THE SOUTHERN U.S. A BROAD INVERTED UPPER TROUGH IS NOTED OVER THE DEEP TROPICAL PACIFIC TO THE S OF 16N BETWEEN 98W AND 108W...AND IS SHIFTING WESTWARD WITH TIME. THIS TROUGH IS EXPECTED TO MERGE WITH HE SOUTHERN PORTION OF THE UPPER TROUGH CURRENTLY DESCRIBED ALONG 120W ON SUN. AN UPPER ANTICYCLONE IS OVER THE NW CARIBBEAN AT 17N85W WITH ITS ENVELOPE OF UPPER ANTICYCLONIC FLOW COVERING THE DISCUSSION AREA E OF 98W. THESE FEATURES COMBINE TO SET UP AN AREA OF UPPER DIFFLUENCE OVER CENTRAL AMERICA AND THE TROPICAL PACIFIC TO THE E OF 105W. UPPER DEBRIS MOISTURE IS NOTED TO THE N OF 05N E OF 105W. ELSEWHERE AT THE SURFACE...A BROAD RIDGE COVERS THE AREA N OF 15N W OF 122W. A TIGHT PRES GRADIENT INLAND CENTRAL AND SE MEXICO HAS RESULTED IN A NORTHERLY SURGE OF 20-25 KT WINDS THROUGH THE CHIVELA PASS IN ACROSS THE GULF OF TEHUANTEPEC. THESE WINDS ARE FORECAST TO DIMINISH ON SUN AS THE PRES GRADIENT THERE RELAXES. NE-E WINDS OF 15-20 KT ARE EXPECTED TO PULSATE THROUGH THE GULF OF PAPAGAYO THROUGH SUN MORNING OR EARLY SUN AFTERNOON BEFORE DIMINISHING. $$ AGUIRRE