000 AXNT20 KNHC 132359 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN JUL 13 2008 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURE.... TROPICAL STORM BERTHA IS CENTERED NEAR 30.2N 63.1W AT 13/2100 UTC ABOUT 175 MILES...285 KM...SOUTHEAST OF BERMUDA. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 990 MB. THE MAXIMUM SUSTAINED WIND SPEED IS 55 KT WITH GUSTS TO 65 KT. A TROPICAL STORM WARNING IS IN EFFECT FOR BERMUDA. PLEASE READ THE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC AND THE PUBLIC ADVISORY UNDER MIATCPAT2/WTNT32 KNHC FOR MORE DETAILS. BERTHA HAS BEEN MEANDERING FOR SOME TIME AS IT HAS BEEN EMBEDDED IN WEAK STEERING CURRENTS...BUT A MOTION TO THE N-NW IS ANTICIPATED OVER THE NEXT COUPLE OF DAYS. IR IMAGERY SHOWS CONVECTION PERSISTING IN THE NE QUADRANT BETWEEN 60 NM AND 180 NM OF THE CENTER. THE W PERIPHERY OF THIS ACTIVITY IS BEING DETECTED ON DOPPLER RADAR FROM BERMUDA AND IS CURRENTLY ABOUT 80 NM SSE OF THE ISLAND. STRONG TROPICAL WAVE IS ALONG 38W/39W S OF 17N MOVING W 15 KT. A 1008 MB LOW IS ANALYZED ALONG THE AXIS NEAR 9N. VISIBLE SATELLITE IMAGES SHOWS A LARGE WELL DEFINED ENVELOPE OF CYCLONIC TURNING...FOCUSED NEAR THE LOW CENTER. A LARGE AREA OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION N OF THE LOW CENTER FROM 9N-13N BETWEEN 36W-41W. FURTHER S...WIDELY SCATTERED MODERATE CONVECTION IS FROM EQ-5N BETWEEN 34W-40W. THIS SYSTEM HAS THE POTENTIAL TO BECOMING A TROPICAL DEPRESSION DURING THE NEXT COUPLE OF DAYS. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 58W S OF 16N MOVING W 15 KT. SYNOPTIC OBSERVATIONS FROM TRINIDAD AND TOBAGO...BARBADOS...ST LUCIA AND OTHER ISLANDS ALL SHOW 24-H PRES FALLS OF ABOUT 3 MB DUE TO THE APPROACH OF THE WAVE. THIS FEATURE HAS BEEN WELL DEFINED FOR DAYS...HOWEVER ITS MOISTURE FIELD HAS FLATTENED SOME TODAY BASED ON THE MIMIC TPW ANIMATION. SCATTERED MODERATE CONVECTION IS OVER THE WINDWARD ISLANDS FROM 9N-13N BETWEEN 60W-63W. TROPICAL WAVE IS ALONG 87W/88W S OF 20N MOVING W 15 KT. 24-H SLP FALLS ARE ABOUT 2-3 MB OVER THE YUCATAN PENINSULA...HONDURAS AND OTHER PARTS OF CENTRAL AMERICA IN ASSOCIATION WITH THE WAVE. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS OVER THE W CARIBBEAN...HONDURAS...AND NICARAGUA FROM 10N-16N BETWEEN 82W-86W. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 9N14W 9N20W 11N32W 7N44W 10N53W 9N60W. BESIDES THE CONVECTION MENTIONED IN THE TROPICAL WAVE SECTION...SCATTERED MODERATE CONVECTION IS ALONG THE COAST OF W AFRICA FROM 11N-13N BETWEEN 15W-18W. SIMILAR CONVECTION IS FROM 8N-10N BETWEEN 19W-22W. ...DISCUSSION... THE GULF OF MEXICO... A 1018 MB HIGH IS CENTERED OVER THE NW GULF OF MEXICO NEAR 27N91W. 5-10 KT WINDS ARE NOTED OVER THE GULF. A SURFACE TROUGH IS OVER N FLORIDA ALONG 32N80W 30N81W 27N83W. ISOLATED MODERATE CONVECTION IS WITHIN 30 NM OF THE TROUGH. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS ALSO OVER THE FLORIDA PANHANDLE AND THE NE GULF FROM 29N-32N BETWEEN 84W-89W. SIMILAR CONVECTION IS OVER INLAND CUBA BETWEEN 78W-84W. ELSEWHERE...SCATTERED MODERATE TO STRONG CONVECTION IS OVER THE YUCATAN PENINSULA AND THE BAY OF CAMPECHE FROM 20N-22N BETWEEN 88W-91W. IN THE UPPER LEVELS...A LARGE UPPER LEVEL HIGH IS CENTERED OVER CENTRAL TEXAS NEAR 31N99W. MOST OF THE GULF OF MEXICO HAS NE TO E UPPER LEVEL FLOW. SIGNIFICANT UPPER LEVEL MOISTURE IS OVER THE E GULF E OF 90W. STRONG SUBSIDENCE IS W OF 90W. EXPECT...CONTINUED CONVECTION OVER THE E GULF OF MEXICO AND FLORIDA DURING THE NEXT 24 HOURS. ALSO EXPECT CONVECTION OVER THE BAY OF CAMPECHE AND THE YUCATAN PENINSULA. THE CARIBBEAN SEA... A TROPICAL WAVE IS OVER THE W CARIBBEAN AND ANOTHER IS ABOUT TO ENTER THE E CARIBBEAN. SEE ABOVE. MODERATE TO FRESH TRADEWINDS DOMINATE THE AREA. SCATTERED MODERATE CONVECTION IS OVER INLAND HISPANIOLA FROM 18N-20N BETWEEN 71W-73W. SIMILAR CONVECTION IS INLAND OVER JAMAICA. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS OVER THE SW CARIBBEAN...PANAMA...AND COSTA RICA FROM 7N-10N BETWEEN 77-84W. IN THE UPPER LEVELS...AN UPPER LEVEL HIGH IS OVER N COLOMBIA NEAR 11N73W. AN UPPER LEVEL LOW IS CENTERED OVER THE LEEWARD ISLANDS NEAR 19N64W. SIGNIFICANT UPPER LEVEL MOISTURE COVERS THE W CARIBBEAN AND CENTRAL AMERICA W OF 70W. STRONG SUBSIDENCE IS OVER THE E CARIBBEAN E OF 70W. EXPECT MORE CONVECTION OVER THE W CARIBBEAN AND CENTRAL AMERICA DURING THE NEXT 24 HOURS. ALSO EXPECT CONVECTION OVER THE E CARIBBEAN DUE TO THE NEW TROPICAL WAVE. THE ATLANTIC OCEAN... A 1020 MB HIGH IS OVER THE W ATLANTIC NEAR 27N70W. HURRICANE BERTHA IS FURTHER E. SEE ABOVE. A 1023 MB HIGH IS OVER THE CENTRAL ATLANTIC NEAR 32N52W. A WEAK SURFACE TROUGH IS OVER THE E ATLANTIC ALONG 31N29W 26N27W MOVING W . SCATTERED SHOWERS ARE WITHIN 90 NM E OF THE TROUGH. SFC REPORTS FROM THE LESSER ANTILLES AND THE HAZY LOOK ON VISIBLE IMAGES ACROSS THE TROPICAL ATLC...SUGGEST THE PRESENCE OF SAHARAN DUST S OF 25N E OF 62W. IN THE UPPER LEVELS...AN UPPER LEVEL LOW IS CENTERED OVER THE BAHAMAS NEAR 26N76W. GOOD UPPER LEVEL OUTFLOW IS NOTED OVER HURRICANE BERTHA. A BROAD UPPER LEVEL TROUGH IS OVER THE CENTRAL ATLANTIC N OF 20N BETWEEN 30W-50W. A LARGE UPPER LEVEL HIGH IS CENTERED OVER THE TROPICAL ATLANTIC NEAR 16N50W. ANOTHER UPPER LEVEL HIGH IS OVER THE COAST OF W AFRICA NEAR 20N20W. $$ FORMOSA