000 AXNT20 KNHC 181035 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 21W S OF 16N MOVING W NEAR 10 KT. AT 850 MB...THERE IS A BROAD CYCLONIC CIRCULATION AND A VORTICITY MAXIMUM SE OF THE CAPE VERDE ISLANDS NEAR 10N21W. CONVECTION HAS INCREASED AHEAD OF THE WAVE AXIS. CLUSTERS OF SCATTRED MODERATE TO ISOLATED STRONG CONVECTION ARE FROM 7N-12N BETWEEN 25W-28W. SCATTERED MODERATE CONVECTION IS ALSO WITHIN THE ITCZ. TROPICAL WAVE IS ALONG 47W S OF 19N MOVING WEST NEAR 10-15 KT. AN INVERTED-V LOW LEVEL SIGNATURE IS WELL DEFINED IN THE NIGHT CHANNEL SAT IMAGERY. A WEAK 1011 MB LOW IS ALONG THE WAVE AXIS NEAR 13N. THE WAVE IS ASSOCIATED WITH A LARGE BUT DISORGANIZED AREA OF SHOWERS AND SCATTERED TSTMS...AND ANY DEVELOPMENT OF THIS SYSTEM IS EXPECTED TO BE SLOW TO OCCUR AS IT CONTINUES WESTWARD. TROPICAL WAVE IS IN THE CENTRAL CARIBBEAN ALONG 79W S OF 20W MOVING W 10-15 KT. SHOWER ACTIVITY IS LIMITED IN ASSOCIATION WITH THIS WAVE. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 9N16W 6N30W 13N46W 11N50W 9N62W. OUTSIDE OF THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVES... SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 5N-7N BETWEEN 21W-29W. 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 EASTERN SEABOARD DIGGING INTO THE E GULF AND THE STATE OF FLORIDA WITH A POSSIBLE LOW CLOSING OFF THE COAST OF FLORIDA PENINSULA. LATEST WV IMAGERY IS ALREADY SHOWING THE UPPER LOW FORMING OFF THE CENTRAL FLA COAST. THERE IS SOME SHOWERS NEAR THE BASE OF THE TROUGH OVER THE SE GULF. WIDELY SCATTERED SHOWERS ARE ALSO SEEN OVER THE WESTERN GULF. AT THE SURFACE...HIGH PRES DOMINATES THE EASTERN 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. THE PRECURSOR OF THIS LOW COULD BE THE SFC TROUGH THAT IS CURRENTLY E OF FLORIDA. THE GFS MODEL MOVES THIS TROUGH WWD INTO THE GULF DURING THIS TIME FRAME. CARIBBEAN SEA... A RIDGE/TROUGH/RIDGE PATTERN IS OBSERVED ACROSS THE CARIBBEAN SEA. AN UPPER HIGH OVER THE YUCATAN PENINSULA EXTENDS A RIDGE OVER THE NW CARIBBEAN AND NORTHERN CENTRAL AMERICA. AN UPPER TROUGH EXTENDS THROUGH THE WINDWARD PASSAGE INTO THE BASIN TO CENTRAL AMERICA NEAR THE PANAMA/COAST RICA BORDER. ANOTHER RIDGE ANCHORED ON A HIGH OVER NORTHERN VENEZUELA DOMINATES THE REMAINDER OF THE REGION. 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 NORTHEAST OF THE NORTHERNMOST LEEWARD ISLANDS. A 1010 MB SFC LOW IS ANALYZED NEAR 18.5N62W. A CLUSTER OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION HAS DEVELOPED NE OF THE LOW THANKS TO A DIFFLUENT PATTERN ALOFT AND THE PRESENCE OF A SFC TROUGH. THIS SHOWER/TSTM ACTIVITY COVERS AN AREA FROM 19N-22N BETWEEN 58W-61W. THE CONVECTIVE ACTIVITY THAT WAS AFFECTING GUADALOUPE AND DOMINICA HAS DIMINISHED. 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 PORTION OF THE GULF AND FLORIDA SUPPORTS A STATIONARY FRONT THAT ENTERS THE REGION NEAR 32N72W...THEN CONTINUES SW TO 28N80W. A SFC TROUGH IS AHEAD OF THE FRONT AND RUNS FROM 28N75W TO 24N79W. A LARGE AREA OF DISORGANIZED CLOUDINESS AND THUNDERSTORMS IS ASSOCIATED WITH THESE FEATURES AND EXTENDS FROM THE EAST COAST OF FLORIDA EASTWARD FOR A FEW HUNDRED MILES OVER THE WESTERN ATLANTIC AND THE BAHAMAS. CONDITIONS ARE CURRENTLY UNFAVORABLE FOR DEVELOPMENT IN THIS AREA...BUT SLOW DEVELOPMENT IS POSSIBLE IN A COUPLE OF DAYS WHEN THE SYSTEM MOVES WESTWARD OVER FLORIDA AND INTO THE EASTERN GULF OF MEXICO. LOCALLY HEAVY RAINFALL IS POSSIBLE OVER PORTIONS OF THE FLORIDA PENINSULA AND THE BAHAMAS DURING THE NEXT DAY OR TWO. AN UPPER RIDGE EXTENDS FROM THE SE BAHAMA NE TO BEYOND 32N67W. AN UPPER LOW REMAINS OVER THE CENTRAL ATLC NEAR 34N53W. AN UPPER TROUGH EXTENDS SW FROM THIS LOW TO NEAR 24N64W. A SURFACE TROUGH ASSOCIATED WITH THIS UPPER TROUGH EXTENDS FROM 30N46W ALONG 25N55W TO NEAR THE SFC LOW...REMNANTS OF INGRID. CLOUDINESS WITH EMBEDDED SHOWERS ARE WITHIN 180 NM EITHER SIDE OF TROUGH. ANOTHER UPPER LOW IS NEAR 32N34W. A SURFACE TROUGH...REFLECTION OF THIS UPPER LOW EXTENDS FROM A 1016 MB SFC LOW LOCATED NEAR 32N39W TO 25N43W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ON THE SOUTHERN 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 WHERE THE PRES GRADIENT TIGHTENS BETWEEN THE AZORES HIGH AND LOWER PRES OVER AFRICA. $$ GR