000 AXPZ20 KNHC 030939 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC THU JUL 03 2008 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 0930 UTC. ...SPECIAL FEATURES... TROPICAL STORM BORIS IS CENTERED NEAR 17.3N 128.6W...OR 1100 NM ...2050 KM...WSW OF CABO SAN LUCAS MEXICO...AT 03/0900 UTC MOVING WNW AT 5 KT. MAXIMUM SUSTAINED WINDS ARE 45 KT WITH GUSTS TO 55 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 996 MB. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS. A HIGH RESOLUTION QUIKSCAT PASS INDICATED THAT THE CENTER OF BORIS WAS FURTHER SOUTH THAN PREVIOUSLY THOUGHT WITH THE DEEP CONVECTION IN THE PROCESS OF DECOUPLING FROM THE LOW LEVEL CENTER...WHICH IS NOW LOCATED ON THE SOUTHERN EDGE OF THE DEEP CONVECTION. NONETHELESS SCATTERED MODERATE ISOLATED STRONG CONVECTION REMAINS ORGANIZED WITHIN 60-75 NM OF A MID LEVEL CIRCULATION NEAR 18.3N128.7W BUT IS RAPIDLY SHRINKING IN AREAL COVERAGE WITH UPPER LEVEL OUTFLOW DIMINISHING AS WELL. BORIS IS OVER 24C WATER AND IS MOVING INTO A MORE STABLE ENVIRONMENT SO CONTINUED WEAKENING IS EXPECTED OVER THE NEXT 24-48 HOURS. TROPICAL STORM DOUGLAS IS CENTERED NEAR 19.6N 109.2W...OR 200 NM S OF CABO SAN LUCAS MEXICO AND 275 NM W OF MANZANILLO MEXICO...AT 03/0900 UTC MOVING WNW AT 8 KT. MAXIMUM SUSTAINED WINDS ARE 35 KT WITH GUSTS TO 45 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1003 MB. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. 20 KT OF EAST-NORTHEASTERLY SHEAR HAS BEGUN TO TAKE ITS TOLL ON DOUGLAS WITH THE LOW-LEVEL CENTER COMPLETELY EXPOSED IN NIGHTTIME INFRARED SATELLITE IMAGERY. A SHRINKING AREA OF SCATTERED MODERATE CONVECTION IS CENTERED 150 NM SW OF THE LOW LEVEL CENTER AND WEAKENING WITH TIME. DOUGLAS WILL LIKELY WEAKEN TO A TROPICAL DEPRESSION WITHIN THE NEXT 12 HOURS. A 1007 MB LOW IS LOCATED NEAR 11N94W...OR ABOUT 345 NM SSE OF PUERTO ANGEL MEXICO...MOVING NW AT 6 KT. THE LOW IS ASSOCIATED WITH A TROPICAL WAVE WHICH HAS BEEN MOVING W ACROSS CENTRAL AMERICA OVER THE PAST COUPLE OF DAYS. THE SYSTEM WAS VOID OF DEEP CONVECTION EARLIER...HOWEVER IS THE PAST FEW HOURS DEEP CONVECTION HAS REDEVELOPED WITHIN 120-150 NM OF THE CENTER IN THE NORTHERN SEMICIRCLE AND NEAR THE LOW LEVEL CENTER AS WELL. TROPICAL CYCLONE DEVELOPMENT IS STILL POSSIBLE WITHIN THE NEXT 48 HRS AS THE SYSTEM MOVES SLOWLY NW OFF THE SOUTHERN COAST OF MEXICO. ...TROPICAL WAVES... SEE SPECIAL FEATURES FOR TROPICAL WAVE AND ASSOCIATED LOW ALONG 95W. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 08N78W TO 11N94W TO 08N110W...THEN FROM 12N127W TO 07N140W. SCATTERED MODERATE ISOLATED STRONG N OF 03N BETWEEN 80W AND 90W...AND N OF 12N TO THE COAST OF CENTRAL AMERICA BETWEEN 88W AND 100W. SCATTERED MODERATE WITHIN 60-90 NM OF THE AXIS BETWEEN 122W AND 130W. ...DISCUSSION... SUBTROPICS... A SHARP UPPER LEVEL TROUGH IS LOCATED OFF THE W COAST OF THE UNITED STATES...WITH THE AXIS EXTENDING FROM AN UPPER LOW NEAR 44N132W TO 30N135W TO 20N139W. 30-40 KT UPPER LEVEL W/SW WINDS CURVE AROUND THE BASE OF THE TROUGH N OF 27N W OF 125W AND SOME UPPER LEVEL CIRRUS IS PLUNGING SE INTO THE AREA ON THE W SIDE OF THE TROUGH. THE TROUGH IS ALLOWING TROPICAL STORM BORIS TO TURN TOWARD THE NW DUE TO THE DEEP-LAYERED FLOW COMING OUT OF THE SE. FARTHER E...AN UPPER HIGH IS CENTERED W OF BAJA CALIFORNIA NEAR 27N119W WHILE A SMALL UPPER LOW IS EMBEDDED WITHIN ITS CIRCULATION NEAR 21N120W. MODERATE/STRONG SUBSIDENCE LIES N OF 20N BETWEEN 110W-125W WITH BROKEN STRATOCUMULUS COVERING THE AREA. THE RIDGE ASSOCIATED WITH THE HIGH COVERS MUCH OF WESTERN MEXICO BUT THEN THE FLOW OVER THE EASTERN HALF OF THE COUNTRY TURNS OUT OF THE NW INTO A DEEP TROUGH OVER THE GULF OF MEXICO. SCATTERED TSTMS ARE LOCATED OVER THE SIERRA MADRES AND THE MEXICAN PLATEAU. TROPICS... WATER VAPOR IMAGERY SHOWS THAT DEEP MOISTURE EXTENDS ACROSS THE ENTIRE TROPICAL REGIME E OF 120W AS WELL AS IN THE VICINITY OF T.S. BORIS NEAR 17N129W. UPPER LEVEL WINDS ARE PRIMARILY EASTERLY S OF 10N BUT ARE MORE VARIABLE FROM 10N-20N DUE TO THE OUTFLOW AROUND T.S. BORIS AND T.S. DOUGLAS. CIMSS WIND ANALYSES INDICATE THAT HIGH SHEAR VALUES ON THE ORDER OF 30-40 KT ARE MAINLY CONFINED BETWEEN 100W-125W...ESPECIALLY DUE TO AN OUTFLOW JET SW OF DOUGLAS. ELSEWHERE...BROAD UPPER LEVEL DIVERGENCE LIES E OF 100W AND WAS ENHANCING CONVECTION NEAR THE SURFACE LOW S OF THE GULF OF TEHUANTEPEC. A COL REGION LIES W OF 130W WHERE THE BASE OF THE MID-LATITUDE TROUGH MEETS THE DEEP-LAYERED TROPICAL EASTERLIES. THIS IS PRODUCING STRONG SUBSIDENCE W OF 133W IN ADVANCE OF T.S. BORIS. $$ COBB