000 AXNT20 KNHC 262353 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT AUG 26 2006 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR... AND METEOROLOGICAL ANALYSIS. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... TROPICAL STORM ERNESTO IS CENTERED NEAR 15.9N 71.6W AT 26/2100 UTC MOVING TOWARD THE WEST-NORTHWEST AT 11 KT. THE CENTER OF ERNESTO IS ALSO ABOUT 165 NM SOUTH SOUTH-EAST OF PORT AU PRINCE HAITI AND ABOUT 325 NM EAST SOUTH-EAST OF KINGSTON JAMAICA. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB. THE MAXIMUM SUSTAINED WINDS ARE 50 KT WITH GUSTS TO 60 KT. SEE THE LATEST NHC FORECAST/ADVISORY UNDER HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. RAINFALL AMOUNTS OF 4 TO 8 INCHES...WITH POSSIBLE ISOLATED MAXIMUM AMOUNTS OF 12 INCHES...ARE EXPECTED IN ASSOCIATION WITH ERNESTO ACROSS PORTIONS OF JAMAICA...HAITI... AND THE DOMINICAN REPUBLIC. THE OUTER BANDS OF ERNESTO MAY PRODUCE 1 TO 3 INCH RAINFALL AMOUNTS ACROSS PUERTO RICO AND THE VIRGIN ISLANDS. ERNESTO IS EXPECTED TO CONTINUE MOVING WNW OVER THE NEXT 24 HOURS AND COULD BE NEAR HURRICANE STRENGTH AS IT APPROACHES JAMAICA AND WESTERN HAITI ON SUNDAY. TROPICAL DEPRESSION DEBBY AT 26/2100 UTC IS CENTERED NEAR 27.0N 47.5W AT 26/2100 UTC MOVING NORTH-NORTHWEST AT 10 KT OVER THE OPEN WATERS OF THE CENTRAL ATLANTIC. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1009 MB. THE MAXIMUM SUSTAINED WINDS ARE 25 KT WITH GUSTS TO 35 KT. SEE THE LATEST NHC FORECAST/ADVISORY UNDER HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. THE DEEP CONVECTION ASSOCIATED WITH DEBBY CONTINUES TO BE DISPLACED NORTH OF THE CENTER DUE TO STRONG SOUTHERLY SHEAR OVER THE CYCLONE. ...TROPICAL WAVES... A TROPICAL WAVE IN THE ERN ATLC IS BEGINNING TO MOVE W OF THE CAPE VERDE ISLANDS ALONG 25W/26W S OF 22N...MOVING W 15 TO 20 KT. THIS WAVE IS ACCOMPANIED BY A 1008MB SURFACE LOW NEAR 17N26W. THE LOW HAS PREVIOUSLY BEEN ANALYZED ALONE...BUT THE WAVE HAS BEEN ADDED DUE TO THE BROAD CYCLONIC CURVATURE SEEN AND CLEAR WAVELIKE SIGNATURE IN GOES LOW LEVEL HIGH DENSITY WINDS S TO 5N. THE WAVE REMAINS NEARLY VOID OF DEEP CONVECTION OUTSIDE OF THE ITCZ REGION...EXCEPT FOR A VERY SMALL CELL OF MODERATE CONVECTION NEAR 18N29W. TROPICAL WAVE IS OVER THE FAR W CARIBBEAN AND CENTRAL AMERICA ALONG 87W/88W S OF 20N MOVING W NEAR 15 KT. WAVE IS BENEATH A STRONG UPPER LOW WHICH IS MASKING THE SATELLITE SIGNATURE. THE N PORTION OF THE WAVE...N OF 13N...IS EMBEDDED WITHIN DRY AIR LIMITING CONVECTION IN THE CARIBBEAN. THIS WAVE MAY NEED TO BE ATTACHED TO THE EPAC LOW W OF NICARAGUA IN THE 00Z MAP. ...THE ITCZ... ITCZ IS CENTERED ALONG 12N16W 8N23W 7N30W TO THE SOUTH AMERICAN COAST NEAR 8N60W...AND RE-EMERGING IN THE SRN CARIBBEAN NEAR 10N76W TO THE COSTA RICAN COAST NEAR 10N83W. A SMALL CLUSTER OF SCATTERED MODERATE CONVECTION IS FROM 7N-9N BETWEEN 27W-30W. MINIMAL SHOWER ACTIVITY IS NOTED W OF 30W THROUGH 47W. SCATTERED MODERATE CONVECTION IS FROM 7N-12N BETWEEN 47W-53W. SCATTERED SHOWERS AND TSTMS ALSO NOTED OVER THE SW CARIBBEAN WITHIN 150NM OF THE AXIS. ...DISCUSSION... GULF OF MEXICO... FAIRLY BROAD MID TO UPPER LEVEL EASTERLY FLOW DOMINATES MUCH OF THE GULF THIS EVENING...SOUTH OF AN UPPER HIGH SEEN SPINNING NEAR TUSCALOOSA ALABAMA. THE EXCEPTION IS A SMALL AREA OF MID TO UPPER CYCLONIC MOTION OFF THE COAST OF NE MEXICO/S TEXAS ASSOCIATED WITH A LINGERING UPPER TROUGH THAT HAS BEEN TRACKED W ACROSS THE GULF THE LAST FEW DAYS. SCATTERED SHOWERS AND TSTMS ARE SEEN IN THE FAR NW CARIBBEAN OFF THE N TEXAS COAST...AND ALSO IN THE NE GULF FROM 24N-30N BETWEEN THE W COAST OF FLORIDA AND 87W. THIS IS ASSOCIATED WITH LOW LEVEL CONFLUENCE BETWEEN NE FLOW AROUND THE WEAK LOW OFF THE ATLC SIDE OF N FLORIDA...AND THE SE FLOW AROUND THE ATLC HIGH EXTENDING INTO THE REGION. A SURFACE TROUGH WAS ADDED TO THE 2100 UTC MAP DUE TO THIS. THESE SHOWERS WILL MOVE W/WSW AROUND THE UPPER HIGH OVER THE NEXT 24 HRS. CARIBBEAN SEA... TROPICAL STORM ERNESTO IS THE MAIN WEATHER MAKER IN THE CARIBBEAN THIS EVENING AS DESCRIBED ABOVE. IN THE WRN CARIBBEAN...ISOLATED SHOWERS AND TSTMS ARE SEEN MOVING CYCLONICALLY AROUND THE UPPER LOW S OF CUBA. THE DIURNAL BUILD UPS OVER WRN CUBA ARE STREAMING TO THE WSW AROUND THIS UPPER LOW. THERE ARE SIGNS OF MID TO UPPER LEVEL ANTICYCLONIC FLOW SEEN OVER THE CENTRAL AND ERN CARIBBEAN...THOUGH SW TO W SHEAR STILL APPEARS TO BE AFFECTING THE E AND N PORTIONS OF ERNESTO. THE LARGE-SCALE MODELS CONTINUE TO FORECAST THE DEVELOPMENT OF A LARGE UPPER-LEVEL ANTICYCLONE ALONG THE FORECAST TRACK OF ERNESTO...ALTHOUGH SO FAR THEY HAVE BEEN TOO FAST IN DOING SO. IF THE MODELS ARE CORRECT...THE CURRENT 15-20 KT OF WESTERLY SHEAR SHOULD DIMINISH DURING THE NEXT 12-24 HR AND ALLOW ERNESTO TO STRENGTHEN. ATLANTIC OCEAN... A SMALL SURFACE LOW AS VERIFIED BY LOW CLOUD FIELDS AND SURFACE OBSERVATIONS IS SEEN JUST OFFSHORE NORTH FLORIDA NEAR 30N80W. A SURFACE TROUGH EXTENDS ENE FROM THIS INTO THE ATLC WATERS THROUGH 34N60W. SCATTERED SHOWERS AND TSTMS MAINLY WITHIN 200NM S OF THIS TROUGH/OLD FRONTAL BOUNDARY ARE STARTING TO BECOME MORE ISOLATED WITH TIME. THIS REGION OF THE WRN ATLC IS ALSO DOMINATED BY A MID TO UPPER LEVEL RIDGE AXIS. AN UPPER LOW IS SEEN SPINNING NEAR 24N71W. UPPER SW FLOW ON THE W SIDE OF THIS LOW IS PULLING MOISTURE FROM ERNESTO NORTH-NORTHEASTWARD. A DISTINCT UPPER LOW NEAR 26N53W CONTINUES TO PRODUCE STRONG SOUTHERLY SHEAR OVER T.D. DEBBY. ISOLATED SHOWERS/TSTMS ARE SEEN WRAPPING AROUND THIS UPPER LOW FROM 21N-30N BETWEEN 50W-60W. MUCH OF THE ERN AND CENTRAL ATLC WATERS FROM 10N-30N BETWEEN THE COAST OF AFRICA AND 45W IS DOMINATED BY BROAD UPPER ANTICYCLONIC FLOW WITH MULTIPLE HIGH CENTERS...DRY AIR...FAIR WEATHER...AND THE S/SW PORTION OF A 1029MB AZORES SURFACE HIGH NEAR 26N45W. THE EXCEPTION IS THE BROAD TROPICAL WAVE MOVING W FROM THE CAPE VERDE ISLANDS. $$ WILLIS