000 AXNT20 KNHC 290004 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON AUG 28 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 FEATURE... THE CENTER OF TROPICAL STORM ERNESTO IS NEAR 21.4N 77.4W AT 29/0000 UTC. THIS POSITION IS JUST INLAND OVER EASTERN CUBA...ABOUT 30 MILES...45 KM...EAST OF CAMAGUEY. OVER THE PAST SEVERAL HOURS ERNESTO HAS BEEN MOVING TOWARD THE WEST-NORTHWEST NEAR 10 KT. HOWEVER...A NORTHWESTWARD MOTION IS EXPECTED TO RESUME LATER TONIGHT...WHICH WOULD TAKE THE CENTER OF CIRCULATION OFF THE NORTH COAST OF CUBA INTO THE ATLANTIC DURING THE NEXT 6 TO 12 HOURS. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1007 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 35 KT WITH GUSTS TO 45 KT. PLEASE REFER TO THE LATEST NHC FORECAST ADVISORY UNDER HEADERS MIATCMAT5/WTNT25 KNHC AND THE PUBLIC ADVISORY MIATCPAT5/WTNT35 KNHC FOR MORE DETAILS. ERNESTO BECAME QUITE DISORGANIZED TODAY AS IT INTERACTED WITH THE MOUNTAINOUS TERRAIN OF CUBA WITH MUCH OF THE CONVECTION REMAINING TO THE E OF THE CENTER OVER ERN CUBA...THE WINDWARD PASSAGE AND WRN HAITI. A SMALL UPPER LOW TO THE N-NW OF ERNESTO MAY HAVE ALSO PROVIDED SOME SHEAR AIDING IN THE DISORGANIZATION. HOWEVER OVER THE PAST SEVERAL HOURS NEW BURSTS OF CONVECTION HAVE FORMED TO THE N AND W OF THE CENTER. RADAR IMAGERY FROM CUBA SHOWS SOME OF THESE SPIRAL BANDS AND CELLS BECOMING BETTER DEFINED. THIS MAY BE AN INDICATION OF THE START OF AN ORGANIZING/STRENGTHENING TREND. STRENGTHENING TO A STRONG TROPICAL STORM IS FORECAST AS ERNESTO MOVES BACK OVER WATER TOWARDS S FLORIDA. ...TROPICAL WAVES... A HIGH AMPLITUDE TROPICAL WAVE IS ALONG 39W S OF 24N MOVING W 15 KT. A 1010 MB LOW IS ALONG THE WAVE NEAR 17.5N. THE SFC LOW IS RATHER LARGE AND WELL-DEFINED ON SATELLITE IMAGERY BUT IS DEVOID OF CONVECTION AS IT IS EMBEDDED IN A DRY STABLE ENVIRONMENT. A TROPICAL WAVE WILL LIKELY BE ADDED TO THE 00 UTC SURFACE ANALYSIS ALONG 23W/24W. THIS WAVE IS NOT VERY HIGH AMPLITUDE AND IS DIFFICULT TO LOCATE AS A MONSOON TROF COVERS MUCH OF THE E TROPICAL ATLC. HOWEVER BASED UPON HOVMOLLER DIAGRAMS AND CURRENT SATELLITE IMAGERY LOW-MID LEVEL CYCLONIC TURNING IS NOTED BETWEEN 21W-25W. IN ADDITION THE GFS MODEL DOES SHOW A WAVE LIKE FEATURE IN A SIMILAR LOCATION. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 12N15W 11N23W 14N37W 9N41W 8N63W. NUMEROUS MODERATE CONVECTION IS MOSTLY INLAND OVER AFRICA E OF 16W FROM 10N-16N LIKELY AHEAD OF A TROPICAL WAVE. SCATTERED MODERATE CONVECTION IS FROM 8N-13N BETWEEN 25W-35W. THE WRN HALF OF THE AXIS IS FAIRLY QUIET BUT NUMEROUS SHOWERS AND TSTMS ARE OVER THE NRN PORTION OF S AMERICA LIKELY ENHANCED BY THE ITCZ. ...DISCUSSION... THE GULF OF MEXICO... ALL EYES ARE ON TROPICAL STORM ERNESTO AS THIS SYSTEM WILL HAVE AN IMPACT ON THE WEATHER IN FLORIDA AND THE ERN GULF OVER THE NEXT COUPLE OF DAYS. FOR MORE INFORMATION REFER TO THE SPECIAL FEATURE SECTION ABOVE. CURRENTLY...THE WEATHER IS QUIET ACROSS A GOOD PORTION OF THE GULF WITH A MID-UPPER LEVEL HIGH CENTERED OVER GEORGIA PRODUCING MODERATE SUBSIDENCE ABOVE MOST OF THE REGION E OF 88W. AN UPPER TROUGH IS DIGGING IN THE SOUTH CENTRAL U.S. BUT CURRENTLY REMAINS N OF THE AREA. THESE FEATURES WILL PROVIDE THE STEERING FOR ERNESTO. A WEAK SFC TROF HAS DEVELOPED IN THE NE GULF FROM THE BIG BEND AREA OF FLORIDA TO 28N87W. ISOLATED SHOWERS HAVE FLARED UP WITHIN 60 NM OF THE BOUNDARY. AN UPPER LEVEL LOW IS IN THE BAY OF CAMPECHE NEAR 22N92W MOVING QUICKLY W. ISOLATED TO SCATTERED SHOWERS ARE WITHIN 300 NM OF THE LOW CENTER. SFC WINDS ARE LIGHT AND VARIABLE ACROSS MOST OF THE AREA. THE CARIBBEAN SEA... THE CENTER OF TROPICAL STORM ERNESTO IS OVER ERN CUBA PRODUCING HEAVY RAINFALL OVER PORTIONS OF WRN HAITI...ERN AND CNTRL CUBA AND THE CNTRL BAHAMAS. ADDITIONAL RAINFALL AMOUNTS OF 2 TO 5 INCHES ARE POSSIBLE OVER WRN HAITI AND 3 TO 6 INCHES OVER E CUBA WITH ISOLATED AMOUNTS UP TO 10 INCHES. DEBRIS MOISTURE HAS SPREAD WELL E OF THE STORM TO ABOUT 66W MOSTLY N OF 16N. FOR MORE DETAILS REFER TO THE SPECIAL FEATURE SECTION ABOVE. THE REMAINDER OF THE CARIBBEAN HAS BROKEN CLOUDINESS AND ISOLATED SHOWERS. VERY DRY STABLE UPPER LEVEL AIR FROM THE TROPICAL ATLC IS BEGINNING TO SPREAD W INTO THE ERN CARIBBEAN ON THE W PERIPHERY OF AN UPPER RIDGE. TRADE WINDS ARE A FAIRLY LIGHT 10-15 KT ACROSS MUCH OF THE AREA...EXCEPT FOR CONSIDERABLY STRONGER WINDS NEAR ERNESTO. THE ATLANTIC OCEAN... A MID-UPPER LEVEL RIDGE CENTERED OVER GEORGIA HAS RIDGING THAT STRETCHES E TO 65W ALONG 32N. AN UPPER TROUGH LIES TO THE E OF THE RIDGE WITH THE UPPER AXIS ALONG 32N51W 27N55W 21N61W. AN ASSOCIATED VERY WEAK FRONTAL BOUNDARY ENTERS THE AREA ALONG 32N51W TO A 1013 MB LOW NEAR 30N57W THEN AS A DISSIPATING FRONT ALONG 26N64W 32N72W. SCATTERED SHOWERS EXIST FROM 27N-32N BETWEEN 54W-58W. CONSIDERABLE CLOUDINESS AND ISOLATED SHOWERS ARE N OF 21N BETWEEN 46W-63W. THE REMAINDER OF THE ATLC IS DOMINATED BY A BROAD UPPER RIDGE EXTENDING FROM AFRICA TO NEAR 50W WITH MULTIPLE HIGH CENTERS. A COUPLE OF WEAK BENIGN UPPER LOWS ARE ON THE W PERIPHERY OF THE RIDGE PRODUCING LITTLE...IF ANY...WEATHER. A MORE NOTICEABLE UPPER LOW IS NEAR 17N40W. UPPER DIFFLUENCE ON THE SW SIDE OF THE CIRCULATION IS LIKELY ENHANCING CONVECTION IN THE ITCZ BETWEEN 25W-35W. ANOTHER UPPER LOW CLIPS THE AREA CENTERED JUST OFF THE COAST OF MOROCCO NEAR 31N13W. AT THE SURFACE...A WEAK PRES GRAD EXISTS W OF 50W DUE TO THE WEAK FRONT DRAPED ACROSS THE NRN PORTION OF THE AREA. STRONGER GRAD IN THE E ATLC AS A 1028 MB HIGH IS CENTERED N OF THE AZORES AND A 1010 MB LOW ALONG A TROPICAL WAVE NEAR 17N39W. $$ CANGIALOSI