000 AXNT20 KNHC 251749 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE 25 MAY 2004 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N INCLUDING NORTHERN SECTIONS OF SOUTH AMERICA. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. THE FORMAT FOR THE ATLANTIC TROPICAL WEATHER DISCUSSION WILL CHANGE ON JULY 6 2004 BEGINNING WITH THE 205 PM ISSUANCE. INFORMATION ABOUT THE CHANGES IS AVAILABLE AT THE FOLLOWING WEB ADDRESS: WWW.WEATHER.GOV/OM/NOTIFICATION/SCN04-26ATL.TXT (ALL LOWERCASE). BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. SPECIAL FEATURE... AS OF 1500 UTC 1011 MB LOW WAS E OF THE BAHAMAS NEAR 25N72W WITH TROUGH EXTENDING NE TO 28N64W AND S FROM THE LOW INTO THE WINDWARD PASSAGE. THE LOW IS WELL-DEFINED IN THE LOW CLOUDS BUT HAS NO SIGNIFICANT DEEP CONVECTION NEAR THE CENTER. THE SYSTEM HAS VERY STRONG VERTICAL WIND SHEAR BUT THIS COULD DIMINISH AS IT ACCELERATES SOME MOVING TOWARD THE NE NEAR THE CREST OF THE UPPER RIDGE TO THE E. THIS AREA IS BEING MONITORED FOR SIGNS OF DEVELOPMENT AND COULD BECOME A TROPICAL CYCLONE IN THE NEXT DAY OR TWO. SCATTERED TO NUMEROUS MODERATE FROM 27N-31N BETWEEN 63W-70W. TROPICAL WAVES/ITCZ... TROPICAL WAVE INTRODUCED ALONG 28W S OF 12N MOVING W 15 KT. LONG-TERM SATELLITE LOOPS SHOW GOOD CONTINUITY AND VISIBLE SATELLITE DISPLAYS A MODEST AMOUNT OF LOW-LEVEL TURNING. ISOLATED MODERATE FROM 3N-5N BETWEEN 27W-30W. TROPICAL WAVE ALONG 43W S OF 14N MOVING W 15 KT. THE MORNING QUIKSCAT PASS OVER THE AREA DEPICTED THE WAVE'S POSITION REASONABLY WELL WITH WEAK CYCLONIC TURNING IN WIND FIELD. ISOLATED WEAK/MODERATE WITHIN 90 NM OF 6N45W. TROPICAL WAVE ALONG 65W S OF 12N MOVING W 15 KT. BEST EVIDENCE FOR THIS WAVE IS WITH CONVECTION OVER VENEZUELA THOUGH THE FEATURE IS NOT PARTICULARLY WELL-DEFINED. NO SIGNIFICANT CONVECTION OVER WATER. TROPICAL WAVE ALONG 74W/75W S OF 17N MOVING W 15 KT. SATELLITE SHOWS A NARROW LINE OF DISSIPATING CONVECTION OVER THE CENTRAL CARIBBEAN WITH EVIDENCE OF TURNING ESPECIALLY NEAR THE NW COAST OF COLOMBIA. IN ADDITION THE NCEP GFS MODEL SEEMS TO PICK UP ON THE WEAK TROPICAL WAVE IN ITS 700 MB INITIALIZATION. ISOLATED MODERATE WITHIN 60 NM OF TROUGH AXIS. AXIS OF ITCZ-RELATED CLOUDS/CONVECTION 5N1W 7N15W 5N30W 7N70W 10N62W. ISOLATED MODERATE N OF 3N E OF 7W AND S OF 6N BETWEEN 31W-38W. WIDELY SCATTERED MODERATE WITHIN 30/45 NM OF AXIS BETWEEN 29W-33W. ISOLATED WEAK/MODERATE WITHIN 45/60 NM OF AXIS BETWEEN 47W-54W WITH SHOWERS WITHIN A SIMILAR DISTANCE OF AXIS BETWEEN 54W-60W. MIDDLE/UPPER LEVEL SYNOPTIC FEATURES... THREE TROUGHS AND THREE HIGHS CONTROL THE REGION IN A VERY AMPLIFIED FLOW REGIME. AN UPPER HIGH OVER MEXICO IS THE MAIN INFLUENCE IN THE WESTERN GULF OF MEXICO W OF 92W. OTHERWISE THE NW CARIBBEAN...THE EASTERN GULF OF MEXICO AND THE NW ATLC HAVE A TROUGH RUNNING FROM 31N75W INTO A WEAK LOW NEAR NASSAU WITH TROUGH CONTINUING SW THE GULF OF HONDURAS. MODERATE/STRONG SUBSIDENCE IS PREVENTING ANY SIGNIFICANT CONVECTION W OF THE TROUGH AXIS TO ABOUT 91W. THE TROUGH IS ALSO PREVENTING ANY SIGNIFICANT DEVELOPMENT OF THE LOW CURRENTLY NE OF THE BAHAMAS WITH STRONG SW WINDS ALOFT. ANOMALOUSLY-STRONG ANTICYCLONE IS SITTING N OF PUERTO RICO NEAR 21N67W WITH ANTICYCLONIC FLOW BASICALLY CONTROLLING THE AREA E OF THE W ATLC/CARIBBEAN TROUGH AXIS TO 55W. ELY WINDS COVER THE CARIBBEAN AND NORTHERN S AMERICA E OF 75W... SOMEWHAT UNUSUAL FOR LATE MAY. DRIER AIR IN THE MID/UPPER LEVELS IS FILTERING IN FROM THE E... HELPING TO END THE PRECIPITATION OVER THE FLOOD RAVAGED AREAS OF HISPANIOLA. THE SYSTEM THAT CAUSED ALL OF THE RAIN OVER THE EASTERN GREATER ANTILLES HAS MOVED FARTHER TO THE N AND E... LEAVING ONLY ISOLATED SHOWERS BEHIND TODAY. THE REST OF THE SUBTROPICAL ATLC HAS AN ELONGATED TROUGH FROM THE CANARY ISLANDS WSW TO 24N36W IN THE CENTRAL ATLC CONTINUING SW TO 10N50W IN THE TROPICAL ATLC. REINFORCING SHORTWAVE TROUGH IS MOVING IN FROM THE W ALONG 48W N OF 23N. GENERAL DRY AIR IN THE MID/UPPER LEVELS NEAR THE TROUGH AXIS AND IN THE TROPICAL ATLC W OF 46W. THE E AND CENTRAL TROPICAL ATLC IS DOMINATED BY A LARGE HIGH OVER W AFRICA WITH AXIS WSW FROM SENEGAL TO 9N45W. HIGH IS SHIFTED MUCH FARTHER N THAN AVERAGE WITH MODESTLY DIFFLUENT ELY FLOW OVER THE ITCZ. SURFACE SYNOPTIC FEATURES... RIDGE IS ACROSS THE NORTHERN GULF COAST FROM A SMALL 1017 MB HIGH ABOUT 200 NM S OF PENSACOLA FLORIDA WITH RIDGE AXIS WNW INTO SE TEXAS. WEAK TROUGH REMAINS IN THE SW CARIBBEAN BETWEEN JAMAICA AND THE CAYMANS SSW TO JUST E OF SAN ANDRES ISLAND TO 10N81.5W. SEE SPECIAL FEATURES FOR DISCUSSION ON THE W ATLC LOW. OTHERWISE HIGH PRESSURE IS ANCHORED IN THE CENTRAL AND E ATLC WITH A FAIR OF 1026 MB HIGHS NEAR 28N51W AND 29N37W. SIGNIFICANT CLOUDS/CONVECTION... GULF OF MEXICO... NONE. CARIBBEAN SEA... ISOLATED MODERATE WITHIN 60 NM OF 11N83W...9.5N80W AND OVER HISPANIOLA. OTHER SHOWERS HAVE MOVED THRU TRINIDAD INTO NE VENEZUELA. TROPICAL ATLANTIC... NONE. SUBTROPICAL ATLANTIC... SEE SPECIAL FEATURES FOR DETAILS ON THE W ATLC LOW. OTHERWISE BROKEN/OVERCAST HIGH CLOUDS COVER THE AREA BETWEEN 50W-75W. $$ BLAKE