000 AXNT20 KNHC 172339 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU JUL 17 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 FEATURES... TROPICAL STORM BERTHA IS CENTERED NEAR 34.0N 57.2W AT 17/2100 UTC MOVING E AT 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. PLEASE SEE 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 MAINTAINING TROPICAL STORM STRENGTH AND MAINTAINING ITS STRUCTURE AS A TROPICAL STORM WITH DEFINED BANDING FEATURES AND OUTFLOW ALOFT. CLUSTERS SCATTERED MODERATE CONVECTION ARE WITHIN 120 NM OF THE CENTER IN THE E SEMICIRCLE. TROPICAL WAVE IS ALONG 66W S OF 18N WITH A 1009 MB LOW ALONG THE WAVE AXIS NEAR 13N. MOVING W NEAR 20 KT. WHILE CONDITIONS CURRENTLY DO NOT APPEAR TO BE FAVORABLE FOR DEVELOPMENT... THUNDERSTORM ACTIVITY ASSOCIATED WITH THE LOW HAS INCREASED DURING THE DAY AND AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT INVESTIGATED THIS SYSTEM EARLIER TODAY AND DID NOT FIND ANY SIGNIFICANT DEVELOPMENT. HOWEVER...HEAVY RAINS AND GUSTY WINDS ARE POSSIBLE IN NORTHERN VENEZUELA AND ADJACENT ISLANDS TONIGHT AND TOMORROW. SCATTERED SHOWERS/THUNDERSTORMS ARE S OF 15N TO OVER THE ABC ISLANDS W OF THE WAVE AXIS TO 71W WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS COVERING THE REMAINDER OF THE AREA S OF 17N BETWEEN 60W-69W. TROPICAL WAVE IS ALONG 82W/83W S OF 21N WITH A 1011 MB LOW ALONG THE WAVE NEAR 14N. THIS SYSTEM HAS SLOWED TO NEAR 10 KT OVER THE PAST 12 HOURS. ALTHOUGH THIS SYSTEM IS NOT EXPECTED TO BECOME A TROPICAL DEPRESSION BEFORE MOVING INLAND TONIGHT...SHOWERS AND GUSTY WINDS ARE SPREADING OVER PORTIONS OF HONDURAS AND NICARAGUA. THIS ACTIVITY COULD CAUSE LIFE-THREATENING FLASH FLOODS AND MUDSLIDES. SCATTERED SHOWERS/THUNDERSTORMS ARE S OF 20N TO INLAND OVER HONDURAS BETWEEN THE WAVE AXIS AND THE COAST OF THE YUCATAN PENINSULA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 11N-20N E OF THE WAVE AXIS TO 75W. A 1014 MB LOW IS JUST OFF THE COAST OF JACKSONVILLE FLORIDA NEAR 30.5N80.5W WITH A SURFACE TROUGH EXTENDING SW ACROSS CENTRAL FLORIDA. ENVIRONMENTAL CONDITIONS COULD ALLOW FOR SOME SLOW DEVELOPMENT OF THIS SYSTEM DURING THE NEXT COUPLE OF DAYS AS THE LOW DRIFTS TO THE NORTH OR NORTH-NORTHEAST. SCATTERED SHOWERS/THUNDERSTORMS FROM INLAND OVER THE FLORIDA PENINSULA AND IN THE W ATLC FROM 27N-29N W OF 80W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 28N-33N W OF 75W TO INLAND OVER FLORIDA AND GEORGIA. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 45W/46W S OF 17N MOVING W NEAR 20 KT. HIGH AMPLITUDE INVERTED-V CURVATURE IS OBSERVED ON SATELLITE IMAGERY WITH NO ASSOCIATED SHOWERS OR DEEP CONVECTION. THE ITCZ... ITCZ AXIS IS CENTERED ALONG 11N15W 5N28W 8N43W 8N53W 12N62W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 75 NM OF THE ITCZ FROM 21W-24W AND FROM 12N-14N E OF 18W TO INLAND OVER W AFRICA. DISCUSSION... GULF OF MEXICO... MOST THE ADVERSE WEATHER IS OVER THE FLORIDA PENINSULA AND INTO THE W ATLC DUE TO THE 1014 MB LOW OFF THE COAST OF JACKSONVILLE FLORIDA. HOWEVER SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 60 NM ALONG THE COAST OF FLORIDA N OF 29N. AN UPPER LOW IS OVER THE NW GULF NEAR 27N94W. AN UPPER RIDGE COVERS THE E GULF PROVIDING DIFFLUENCE ALOFT TO GENERATE A SMALL AREA OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS IN THE CENTRAL GULF N OF 25N TO INLAND OVER LOUISIANA BETWEEN 89W-93W. OTHERWISE THE REMAINDER OF THE GULF REMAINS TRANQUIL THIS EVENING. CARIBBEAN SEA... THE FOCUS THIS EVENING FOR THE W CARIBBEAN IS TWO FOLD...THE TROPICAL WAVE ALONG 82W/83W AND THE E CARIBBEAN TROPICAL WAVE ALONG 66W. SEE SPECIAL FEATURES ABOVE. THESE TWO SYSTEMS ENCOMPASS MOST OF THE CARIBBEAN. AFTERNOON HEAVY SHOWERS/ SCATTERED THUNDERSTORMS HAVE DEVELOPED OVER CUBA AND ARE SPREADING S INTO THE ADJACENT COASTAL WATERS. MOST NOTICEABLY IS THE LACK OF SHOWERS OVER THE LEEWARD/VIRGIN ISLANDS AND PUERTO RICO AS WELL AS THE YUCATAN CHANNEL. ATLANTIC OCEAN... THE MAIN FOCUS FOR THE W ATLC IS THE 1014 MB LOW OFF COAST NEAR JACKSONVILLE FLORIDA. SEE SPECIAL FEATURES ABOVE AND TROPICAL STORM BERTHA N OF THE REGION. A SMALL BUBBLE OF HIGH PRESSURE IS LOCATED S OF T.S. BERTHA CENTERED BY A 1021 MB HIGH NEAR 27N67W. UPPER HIGHS ARE BOTH SE AND SW OF BERTHA AND KEEPING MOST OF THE REGION DRY TONIGHT. A SMALL AREA OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS IS S OF BERMUDA FROM 28N-30N BETWEEN 62W-67W DUE TO DIFFLUENCE ALOFT. A SURFACE RIDGE COVERS THE E ATLC E OF 50W ANCHORED BY 1036 MB HIGH N OF THE AZORES. $$ WALLACE