000 AXNT20 KNHC 180548 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE SEP 18 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 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...METEOROLOGICAL ANALYSIS... WEATHER OBSERVATIONS...AND RADAR. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 20W S OF 16N MOVING W NEAR 10 KT. THIS FEATURE SHOWS UP WELL AS A LOW AMPLITUDE MOISTURE SURGE ON THE UW-CIMSS TPW PRODUCT. AT 850 MB...THERE IS A BROAD CYCLONIC CIRCULATION AND A VORTICITY MAXIMUM SE OF THE CAPE VERDE ISLANDS NEAR 10N21W. A CLUSTER OF MODERATE TO ISOLATED STRONG CONVECTION IS BEHIND THE WAVE AXIS MOVING OFF THE AFRICAN COAST FROM 11N-15N. TROPICAL WAVE IS TILTED 19N42W 5N44W. A WEAK 1012 MB LOW IS ALONG THE WAVE AXIS NEAR 13N. THE WAVE IS ASSOCIATED WITH A LARGE BUT DI ARE OF SHOWERS AND SCATTERED TSTMS...AND ANY DEVELOPMENT OF THIS SYSTEM IS EXPECTED TO BE SLOW TO OCCUR AS IT CONTINUES WESTWARD AT 10 TO 15 MPH. TROPICAL WAVE IS IN THE CENTRAL CARIBBEAN ALONG 77W/78W S OF 20W MOVING W 10-15 KT. SHOWER ACTIVITY IS LIMITED IN ASSOCIATION WITH THIS WAVE. UPPER LEVEL WINDS ARE UNFAVORABLE FOR DEVELOPMENT IN THIS AREA. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 11N16W 7N21W 11N42W 12N46W 7N60W. OUTSIDE OF THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVES... SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 5N-11N BETWEEN 22W-28W. DISCUSSION... GULF OF MEXICO... AN UPPER LOW IS INLAND OVER MEXICO NEAR TAMPICO AND COVERS THE THE FAR WEST GULF. AN UPPER RIDGE EXTENDS FROM THE YUCATAN PENINSULA NW TO THE LOUISIANA/TEXAS BORDER. A DEEP LAYERED UPPER TROUGH IS OVER THE E US INTO THE W ATLC DIPPING S OVER THE NE QUADRANT OF THE GULF WITH A POSSIBLE LOW CLOSING OFF THE COAST OF FLORIDA. DIFFLUENT BETWEEN THESE UPPER FEATURES IS SUPPORTING SOME SHOWER ACTIVITY OVER THE GULF AND SOUTH-CENTRAL FLORIDA. SCATTERED SHOWERS ARE ALSO SEEN OVER THE WESTERN GULF SOUTH OF 27N. AT THE SURFACE...HIGH PRES DOMINATES THE E US AND THE GULF PRODUCING LIGHT TO MODERATE NELY WINDS N OF 25N. SOME OF THE COMPUTER MODELS ARE SUGGESTING A SFC LOW WILL DEVELOP IN THE ERN GULF WED NIGHT AND THU...BUT THE EXACT TIMING...LOCATION...AND INTENSITY OF THIS FEATURE ARE HIGHLY UNCERTAIN AT THIS POINT. CARIBBEAN SEA... AN UPPER HIGH OVER THE YUCATAN PENINSULA EXTENDS A RIDGE OVER COVERS THE NW CARIBBEAN AND NORTHERN CENTRAL AMERICA. AN UPPER CENTERED IN THE WINDWARD PASSAGE EXTENDING AN UPPER TROUGH SW TO CENTRAL AMERICA NEAR THE PANAMA/COAST RICA BORDER. ANOTHER RIDGE ANCHORED ON A HIGH OVER NORTHERN VENEZUELA DOMINATES THE REMAINDER OF THE BASIN. ABUNDANT MID/UPPER LEVEL MOISTURE IS BEING ADVECTED EAST OF THE UPPER TROUGH FROM N SOUTH AMERICA ACROSS THE CENTRAL CARIBBEAN INTO THE ATLC THROUGH HISPANIOLA AND PUERTO RICO. A TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN INTERACTING WITH THIS UPPER LOW/TROUGH. LATEST SATELLITE IMAGERY ONLY SHOWS WIDELY SCATTERED SHOWERS OVER THE AREA. THE REMNANTS OF TROPICAL DEPRESSION INGRID ARE LOCATED JUST EAST OF THE NORTHERNMOST LEEWARD ISLANDS. A 1011 MB SFC LOW IS ANALYZED NEAR 18N61W. A CLUSTER OF SCATTERED MODERATE CONVECTION IS JUST SOUTH OF THIS LOW AFFECTING GUADELOUPE AND DOMINICA WITH SHOWERS AND TSTMS. REDEVELOPMENT IS NOT EXPECTED DURING THE NEXT COUPLE OF DAYS AS THIS SYSTEM MOVES SLOWLY NORTHWESTWARD. LIGHT TO MODERATE TRADE WINDS ARE IN PLACE. ATLANTIC OCEAN... THE DEEP LAYERED TROUGH ALONG THE EASTERN SEABOARD DIGGING INTO THE NE PORTION OF THE GULF SUPPORTS A STATIONARY FRONT THAT ENTERS THE REGION NEAR 32N72W...THEN CONTINUES SW TO 28N79W. A SFC TROUGH IS AHEAD OF THE FRONT AND RUNS FROM 29N75W TO 24N77W. SCATTERED SHOWERS AND TSTMS ARE ASSOCIATED WITH THE FRONT/TROUGH COVERING THE W ATLC W OF 70W...INCLUDING ALSO THE BAHAMAS. AN UPPER RIDGE EXTENDS FROM THE SE BAHAMA NE TO BEYOND 32N67W. AN UPPER LOW REMAINS OVER THE CENTRAL ATLC NEAR 34N52W. AN UPPER TROUGH EXTENDS SW TO NEAR 24N67W. A SURFACE TROUGH ASSOCIATED WITH THIS UPPER TROUGH EXTENDS FROM 30N48W ALONG 27N56W TO NEAR 24N62W. A CLUSTER OF SCATTERED MODERATE CONVECTION COVERS AN AREA SE OF THE SURFACE TROUGH FROM 21N025N BETWEEN 51W-55W. ANOTHER UPPER LOW IS NEAR 32N34W. A SURFACE TROUGH...REFLECTION OF THIS LOW EXTENDS FROM A 1017 MB LOW ALONG 27N37W TO 27N42W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ON THE WESTERN END OF THE TROUGH. WLY ZONAL FLOW IS IN CONTROL OF THE REMAINDER OF THE ATLC FROM 20N-32N. UPPER RIDGING IS OVER THE TROPICAL ATLC. AT THE SFC...TYPICAL SFC RIDGING IS OVER THE REMAINDER OF THE E ATLC PRODUCING MODERATE NE TRADES E OF 30W...STRONGEST ALONG THE NW COAST OF AFRICA. $$ GR