000 AXNT20 KNHC 151135 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST WED MAR 15 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 4N5W 2N10W 4N19W 2N24W 3N45W S OF THE EQUATOR ALONG THE COAST OF SOUTH AMERICA NEAR 50W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 7N TO THE EQUATOR E OF 16W TO THE PRIME MERIDIAN. CLUSTERS OF SCATTERED MODERATE CONVECTION FROM 5N TO THE EQUATOR BETWEEN 16W-40W AND S OF 5N W OF 50W TO INLAND OVER SOUTH AMERICA. ...DISCUSSION... GULF OF MEXICO... DEEP LAYERED TROUGH CONTINUES TO MOVE OVER THE W ATLC EXITING THE E US AND CLIPPING THE NW GULF WITH THE ASSOCIATED COLD FRONT EXTENDING INTO THE GULF ACROSS FLORIDA NEAR LAKE OKEECHOBEE W TO 23N92W WHERE IT DISSIPATES S TO OVER THE BAY OF CAMPECHE AND S MEXICO NEAR 18N94W. A STATIONARY FRONT REMAINS ALONG THE E SLOPES OF THE SIERRA MADRE MOUNTAINS. BROKEN/OVERCAST LOW CLOUDS WITH ISOLATED SHOWERS ARE WITHIN 60 NM OF THE FRONT. THE S GULF IS UNDER AN UPPER RIDGE EXTENDING FROM THE NW CARIBBEAN COVERING THE AREA WITH W TO NW UPPER FLOW. A SURFACE RIDGE CONTINUES TO BUILD S INTO THE N GULF WITH A 1028 MB HIGH OVER THE LOWER MISSISSIPPI VALLEY. THE WESTERN PORTION OF THE FRONTAL BOUNDARY IS BEGINNING TO WASH OUT AS RETURN FLOW ON THE BACK SIDE THE SURFACE RIDGE PUSHING DOWN FROM OVER THE SE US COVERING THE W GULF W OF 92W. CARIBBEAN SEA... AN UPPER HIGH IS IN THE YUCATAN CHANNEL NEAR 20N85W GIVING THE NW CARIBBEAN UPPER NE TO E FLOW. THE UPPER LOW THAT WAS JUST N OF THE DOMINICAN REPUBLIC HAS ELONGATED OVER THE PAST 6 HOURS AND NOW IS AN UPPER TROUGH THAT EXTENDS FROM THE W ATLC ACROSS HISPANIOLA INTO THE CENTRAL CARIBBEAN TO NEAR 15N76W. BROAD UPPER RIDGE OVER THE TROPICAL ATLC REMAINS GIVING THE E AND SW CARIBBEAN UPPER SW FLOW S OF A LINE FROM PUERTO RICO NEAR 18N66W TO COSTA RICA NEAR 10N82W. STRONG SUBSIDENCE AND DRY UPPER AIR DOMINATE MOST OF THE CARIBBEAN WITH THE EXCEPTION OF THE AREA SURROUNDING THE LESSER ANTILLES WHERE TROPICAL MOISTURE IS BEING ADVECTED FROM OVER SOUTH AMERICA AND FROM THE E WITH THE EASTERLY TRADES. THIS IS GENERATING SCATTERED SHOWERS S OF 17N BETWEEN 58W-65W. AFRICAN DUST IS MOVING INTO THE FAR E CARIBBEAN GIVING THE WINDWARD ISLANDS HAZY CONDITIONS. THE REMAINDER OF THE CARIBBEAN IS UNDER GENERALLY CLEAR SKIES WITH MODERATE/ STRONG EASTERLY TRADE WINDS. LITTLE CHANGE IS EXPECTED FOR MOST OF THE AREA WITH THE EXCEPTION OF THE AFRICAN DUST THAT WILL CONTINUE TO SPREAD WESTWARD. ATLANTIC OCEAN... DEEP LAYERED TROUGH OVER THE W ATLC AND FAR E US IS N OF 27N W OF 68W WITH THE ASSOCIATED COLD FRONT EXTENDING INTO THE AREA NEAR 32N73W ACROSS FLORIDA NEAR LAKE OKEECHOBEE CONTINUING INTO THE GULF. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 120 NM E OF THE FRONT N OF 29N WITH ISOLATED SHOWERS WITHIN 90 NM E OF THE FRONT TO OVER THE BAHAMA ISLANDS. WEAK...NARROW UPPER RIDGE EXTENDS FROM THE UPPER HIGH IN THE YUCATAN CHANNEL ACROSS CUBA NEAR 23N80W OVER THE BAHAMAS TO BEYOND 32N62W AIDING THE GENERATION OF THE SHOWERS/THUNDERSTORMS ASSOCIATED WITH THE FRONT. THE CUT-OFF UPPER LOW...NOW AN ELONGATED UPPER TROUGH EXTENDS FROM 24N62W ACROSS HISPANIOLA NEAR 19N70W. MODERATE/ STRONG SUBSIDENCE AND DRY UPPER AIR COVERS THE ATLC FROM 20N-30N BETWEEN 40W-70W. BROAD UPPER RIDGE COVERS THE CENTRAL ATLC BETWEEN 35W-60W. AT THE SURFACE...A 1023 MB HIGH IS LOCATED NEAR 26N53W WITH A RIDGE COVERING THE MOST OF THE ATLC E OF THE FRONT TO 30W. A VERY WELL DEFINED DEEP LAYERED LOW...AND THE ASSOCIATED STORM CENTER IS N OF THE REGION WITH THE UPPER TROUGH EXTEND THROUGH 32N19W TO NEAR THE CANARY ISLANDS. THE ASSOCIATED FRONTAL BOUNDARY REMAINS N OF THE REGION. THE MOST SIGNIFICANT WEATHER FEATURE FOR THE DAY IS THE DENSE AFRICAN DUST THAT COVERS THE E ATLC FROM 5N-18N E OF 42W SUPPRESSING THE ITCZ AXIS TO THE S...SEVERELY LIMITING CLOUD FORMATION AND VISIBILITY ESPECIALLY TO THE CAPE VERDE ISLANDS...ALTHOUGH SOME CLEARING IS OBSERVED JUST OFF THE COAST OF AFRICA N OF 10N ON THE FIRST VISIBLE SATELLITE IMAGES. BROAD UPPER HIGH REMAINS IN THE TROPICS NEAR 6N32W COVERING THE E ATLC S OF 20N...THE ENTIRE TROPICAL ATLC...AND A PORTION OF THE CARIBBEAN. OTHERWISE... GENERALLY TRANQUIL WEATHER PREVAILS OVER THE MOST OF THE ATLC. $$ WALLACE