000 AXNT20 KNHC 141759 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON JUL 14 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURE.... TROPICAL STORM BERTHA IS CENTERED NEAR 32.5N 64.1W AT 14/1500 UTC ABOUT 35 NM EAST-NORTHEAST OF BERMUDA. THE MINIMUM CENTRAL PRESSURE IS 996 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 IS EXPECTED TO CONTINUE ITS NORTHWARD MOTION OVER THE NEXT COUPLE OF DAYS. IR IMAGERY AND DOPPLER RADAR SHOWS CONVECTION INCREASING SLIGHTLY WITH SCATTERED MODERATE CONVECTION ORGANIZED IN A LARGE BAND WITHIN 180 NM N AND 120 NM S OF THE CENTER WITH THE HEAVIEST RAINFALL LOCATED IN THE NORTHWEST QUADRANT. SFC DATA FROM BERMUDA (TXKF) REPORTED HIGHEST SUSTAINED WINDS OF 32 KT WITH GUSTS TO 48 KT. STRONG TROPICAL WAVE IS ALONG 42W S OF 17N MOVING W 10-15 KT. A 1008 MB LOW IS ANALYZED ALONG THE AXIS NEAR 12N. SATELLITE IMAGERY SHOWS A LARGE WELL DEFINED ENVELOPE OF CYCLONIC TURNING...FOCUSED NEAR THE LOW CENTER. CONVECTION HAS DECREASED SLIGHTLY WITH SCATTERED MODERATE CONVECTION LIMITED TO 90 NM N AND 150 NM S OF THE CENTER. A LARGER AREA OF CONVECTION IS FARTHER S EMBEDDED IN THE ITCZ. THIS SYSTEM COULD BECOME A TROPICAL DEPRESSION LATER TODAY OR TOMORROW. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 63W/64W S OF 18N MOVING W 15-20 KT. THIS FEATURE HAS BEEN WELL DEFINED FOR THE PAST COUPLE OF DAYS. IR SATELLITE IMAGERY EXHIBITS INVERTED-V SIGNATURE WITH CYCLONIC CURVATURE ALONG THE AXIS NEAR 11N. SFC OBSERVATION AND QSCAT DATA REVEALS A NE-SE WIND SHIFT AND AN INCREASE IN SPEED E OF THE AXIS. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 10N-13N BETWEEN 61W-66W. TROPICAL WAVE PREVIOUSLY OVER THE BAY OF CAMPECHE HAS MOVED OUT OF THE AREA. REFER TO THE E PACIFIC...TWDEP...FOR MORE DETAILS. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 12N16W 9N24W 5N35W 8N46W 7N55W 11N62W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 150 NM N OF THE AXIS E OF 18W. SCATTERED MODERATE CONVECTION IS FROM 5N-10N BETWEEN 21W-28W...2N-6N BETWEEN 38W-44W AND WITHIN 150 NM EITHER SIDE OF THE AXIS BETWEEN 30W-37W. ...DISCUSSION... THE GULF OF MEXICO... A WEAK RIDGE OF HIGH PRESSURE EXTENDS FROM THE W ATLC TO THE WRN GULF OF MEXICO ALONG 24N. A WEAKENING SURFACE TROUGH IS OVER FLORIDA FROM JACKSONVILLE TO TAMPA. NUMEROUS SHOWERS AND TSTMS ARE OVER THE NE GULF N OF 25N BETWEEN 84W-90W. SCATTERED SHOWERS REMAIN OVER THE SE GULF...S FLORIDA AND THE STRAITS S OF 26N E OF 84W. IN THE UPPER LEVELS...A LARGE HIGH IS CENTERED OVER NORTH CENTRAL MEXICO NEAR 31N106W AND A LOW IS OVER THE W ATLC NEAR 31N77W. THIS IS PROVIDING MOST OF THE GULF WITH N TO NE FLOW. SIGNIFICANT UPPER LEVEL MOISTURE IS E OF 90W WITH DEEPER MOISTURE NEAR A WEAK SHORTWAVE OVER THE NE GULF. STRONG SUBSIDENCE IS W OF 90W. THE CARIBBEAN SEA... A TROPICAL WAVE IS OVER THE ERN CARIBBEAN ALONG 63W/64W. SCATTERED SHOWERS AND TSTMS REMAIN CONFINED TO THE SE CARIBBEAN AND ACROSS THE SRN WINDWARD ISLANDS. SEE ABOVE. MODERATE TO STRONG TRADEWINDS DOMINATE THE AREA. SCATTERED SHOWERS AND TSTMS IS OVER THE SW CARIBBEAN FROM 10N-14N W OF 78W. IN THE UPPER LEVELS...A FLAT RIDGE IS OVER NRN COLOMBIA AND THE SW CARIBBEAN AND A BROAD UPPER LEVEL TROUGH EXTENDS FROM AN UPPER LOW NEAR 18N75W. SIGNIFICANT MOISTURE ALOFT COVERS THE WRN CARIBBEAN AND CENTRAL AMERICA W OF 70W. STRONG SUBSIDENCE LIES ABOVE PUERTO RICO AND THE VIRGIN ISLANDS. EXPECT CONVECTION IS SPREAD W WITH THE ACTIVE TROPICAL WAVE IN THE E CARIB. THE ATLANTIC OCEAN... TROPICAL STORM BERTHA IS JUST N OF THE AREA...SEE ABOVE. A BENIGN SURFACE TROUGH EXTENDS INTO THE DISCUSSION AREA NEAR 32N41W 28N44W. SFC REPORTS FROM THE LESSER ANTILLES AND THE HAZY LOOK ON VISIBLE SATELLITE IMAGES TODAY ACROSS THE TROPICAL ATLC SUGGEST THE PRESENCE OF SAHARAN DUST S OF 25N E OF 63W. IN THE UPPER LEVELS...A LOW IS CENTERED OFF THE U.S. SE COAST NEAR 31N77W WITH TROUGHING EXTENDING S-SE TO THE WINDWARD PASSAGE AND HISPANIOLA. DIFFLUENCE ALOFT IS PRODUCING AN AREA OF SCATTERED SHOWERS AND TSTMS MAINLY S OF THE LOW FROM 24N-28N BETWEEN 77W-80W AS INDICATED ON LIGHTNING DATA. A BROAD UPPER LEVEL TROUGH IS OVER THE CENTRAL ATLANTIC N OF 20N BETWEEN 35W-55W. A LARGE UPPER LEVEL HIGH IS CENTERED OVER THE TROPICAL ATLANTIC NEAR 17N57W. ANOTHER UPPER LEVEL HIGH IS OFFSHORE OF THE WRN COAST OF AFRICA BETWEEN THE CANARY AND CAPE VERDE ISLANDS NEAR 25N20W. $$ WALTON/CANGIALOSI