000 AXPZ20 KNHC 282230 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SAT JUN 28 2008 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2215 UTC. ...SPECIAL FEATURES... TROPICAL STORM BORIS IS CENTERED NEAR 14.8N 113.9W...OR ABOUT 620 NM SSW OF THE SRN TIP OF BAJA CALIFORNIA MANZANILLO MEXICO...OR ABOUT 645 NM S OF THE SRN TIP OF BAJA CALIFORNIA AT 28/2100 UTC MOVING WNW AT 10 KT. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS. OVERALL STRUCTURE OF THE CYCLONE HAS CHANGED LITTLE DURING THE PAST 6 HOURS. VERY COLD TOP DEEP CONVECTION CONSISTS OF THE SCATTERED STRONG TYPE WITHIN 90 NM NE QUADRANT...150 NM E QUADRANT AND 180 NM SE QUADRANT OF THE CENTER. UPPER LEVEL VERTICAL SHEAR IS AFFECTING THE CYCLONE SOME CAUSING FOR THE LOW-LEVEL CENTER TO BE PARTIALLY EXPOSED ON THE N SIDE AS NOTED IN LOW CLOUD LINES SPIRALING INWARD TOWARDS THE CENTER IN THE N PORTION OF THE CYCLONE. OUTFLOW IS MOST EVIDENT OVER THE WRN SEMICIRCLE. BORIS IS FORECAST TO SLOWLY WEAKEN THROUGH THE 48 HOURS REACHING DEPRESSION SHORTLY THEREAFTER AS IT MOVES OVER COOLER SEA SURFACE TEMPERATURES. TROPICAL STORM CHRISTINA IS CENTERED NEAR 14.6N 125.4W...OR ABOUT 1165 NM WSW OF THE SRN TIP OF BAJA CALIFORNIA AT 28/1800 UTC MOVING W AT 7 KT. MAXIMUM WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. ESTIMATED MINIMUM PRESSURE IS 1003 MB. LATEST SATELLITE IMAGERY SHOWS THAT THIS SYSTEM HAS ACQUIRED WELL DEFINED BANDING FEATURES PRIMARILY OVER THE NW AND SE SECTORS OF THE CYCLONE. LOW-LEVEL CLOUD LINES ARE NOW CLEARLY EXPOSED WITHIN 90 NM NE THROUGH S OF THE CENTER. SCATTERED STRONG CONVECTION IS WITHIN 150 NM OF THE CENTER OVER THE SW QUADRANT. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 30 NM OF A LINE FROM 17N123W TO 16N126W. THE CYCLONE IS FORECAST TO WEAKEN TO A DEPRESSION IN ABOUT 48 HOURS AS IT MOVES INTO A MORE STABLE ENVIRONMENT MADE UP COOLER WATER TEMPERATURES ...AND MARKED BY SCATTERED TO BROKEN STRATOCUMULUS CLOUDS JUST TO ITS NW. ...TROPICAL WAVE... TROPICAL WAVE IS ALONG 96W N OF 8N WITH A LOW CENTER OF 1010 MB NEAR 8N96W. THIS SYSTEM IS MOVING W 10-15 KT. LATEST SATELLITE IMAGERY SHOWS THAT CYCLONIC TURNING OF THE LOW LEVEL CLOUD FIELD IS NOT AS EVIDENT AS 18-24 HOURS AGO...AND THE SYSTEM IS PRESENTLY POORLY ORGANIZED. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM EITHER SIDE OF THE WAVE FROM 10N-14N. OTHER ASSOCIATED CONVECTION IS TIED IN WITH THE ITCZ AS DESCRIBED BELOW. GLOBAL MODELS STILL LATCH ON TO THIS WAVE AND LOW...AND DEVELOP IT OVER THE NEXT FEW DAYS AS THEY IT TRACK IT IN A WNW DIRECTION. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 7N78W TO 8N85WW TO 6N94W TO 6N100W TO 11N112W TO 13N122W TO 7N132W TO 7N140W. SCATTERED STRONG CONVECTION IS 180 NM N OF THE AXIS BETWEEN 91W-93W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 180 NM N OF THE AXIS BETWEEN 95W-101W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM OF THE AXIS W OF 132W...AND ALSO S OF THE AXIS WITHIN 30 NM OF A LINE FROM 7N112W TO 7N114W. ...DISCUSSION... E OF 130W... THIS AREA IS PRIMARILY DOMINATED BY A NEARLY STATIONARY UPPER LEVEL ANTICYCLONE LOCATED TO THE NE OF TROPICAL STORM CHRISTINA NEAR 17N121W. A RIDGE EXTENDS NEWD FROM THE ANTICYCLONE TO CENTRAL BAJA CALIFORNIA. A CUT-OFF UPPER LOW IS WELL N OF THE AREA NEAR 25N130W. A TROUGH EXTENDS FROM THE LOW ESE TO OVER SRN CALIFORNIA. THE FLOW BETWEEN THESE TWO FEATURES IS RATHER CONFLUENT RESULTING IN MODERATE TO STRONG SUBSIDENCE N OF 20N. THE FLOW THEN BECOMES DIFFLUENT OVER THE FAR NE PART OF THE AREA...E TO ACROSS BAJA CALIFORNIA AND THE SW UNITED STATES. THE UPPER LEVEL FLOW IS ANTICYCLONIC S OF ABOUT 25N BETWEEN 108W AND 130W. ABUNDANT DEEP-LAYERED MOISTURE EXISTS TO THE SE OF THE RIDGE WHERE STRONG NE UPPER LEVEL WINDS WITH SPEEDS IN THE 20-25 KT ARE OBSERVED. THESE WINDS ARE CREATING NE SHEAR ABOVE TROPICAL STORM BORIS. A DEEP LAYERED TROUGH IS FORECAST TO SWEEP THROUGH THE NW PORTION OF THE AREA OVER THE NEXT 48-72 HOURS. W OF 130W... AN UPPER LEVEL ANTICYCLONE IS NEAR 12N139W WITH A RIDGE NE TO 16N135W. MODERATE SUBSIDENCE PRODUCING A STABLE ENVIRONMENT IS NOTED OVER MUCH OF THIS AREA...EXCEPT NW OF A LINE FROM 20N140W TO 26N130W WHERE UPPER LEVEL MOISTURES IS STREAMING EWD INTO THE AREA. UPPER LEVEL OUTFLOW RELATED MOISTURE FROM TROPICAL STORM CHRISTINA IS SLOWLY SPREADING INTO THE FAR SE PORTION OF THE AREA TO THE S OF 20N AND E OF 131W. MODERATE TO STRONG UPPER LEVEL ELY WINDS ARE NOTED IN SATELLITE-DERIVED WIND DATA TO BE CONFINED TO THE S OF 9N. A DEEP LAYERED TROUGH IS JUST MOVING INTO THE FAR NW CORNER OF THE AREA. THIS TROUGH IS FORECAST TO SWEEP THROUGH THE NRN PORTION OF THE AREA DURING THE NEXT 48 HOURS WITH ITS ASSOCIATED WEAKENING COLD FRONT PROBABLY ENTERING THE FAR NW WATERS EARLY TUE MORNING. EXPECT INCREASING SLY FLOW AHEAD OF THE FRONT. SEAS MAY ALSO BUILD AHEAD AND BEHIND THE FRONT ACCORDING TO THE LATEST WAVEWATCH MODEL GUIDANCE. $$ AGUIRRE