000 AXNT20 KNHC 171755 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST MON NOV 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... A LOW AMPLITUDE TROPICAL WAVE IS OVER THE EASTERN CARIBBEAN ALONG 65W/66W SOUTH OF 17N MOVING SLOWLY WWD. WE HAVE BEEN FOLLOWING THIS WAVE/TROUGH FOR THE LAST SEVERAL DAYS. AT LEAST SINCE NOVEMBER THE 13TH...THE HOVMOLLER DIAGRAM HAS BEEN SHOWING THIS FEATURE TO BE PROPAGATING WWD. THIS WAVE IS ALSO WELL DEPICTED IN THE MOISTURE PRODUCT AND SFC OBSERVATIONS. THIS SYSTEM IS GENERATING SCATTERED MODERATE CONVECTION OVER THE SE CARIBBEAN PARTICULARLY SOUTH OF 15N AND EAST OF 67W. THE SHOWER ACTIVITY EXTENDS EWD ACROSS THE WINDWARD ISLANDS AND INTO THE TROPICAL N ATLC. BARBADOS REPORTED A TOTAL OF 2.10 INCHES OF RAIN FOR THE PAST 24 HOURS. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 7N13W 6N30W 7N40W 7N50W INTO THE GUYANAS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-9N BETWEEN 20W-29W. ...DISCUSSION... GULF OF MEXICO... SURFACE HIGH PRES WITH A COUPLE OF 1029 MB CENTERS OVER THE UPPER TEXAS COAST AND NE MEXICO DOMINATES THE ENTIRE REGION AND THE NORTHERN GULF STATES. THIS FEATURE IS PRODUCING A SUNNY AND DRY DAY OVER THE SE CONUS INCLUDING THE STATE OF FLORIDA. NORTHERLY WINDS OF 15 TO 20 KT ARE BLOWING ACROSS THE GULF WITH THE STRONGEST WINDS OVER THE BAY OF CAMPECHE AND THE SE GULF INCLUDING THE STRAITS OF FLORIDA. ADDITIONALLY...STRONG N SFC WINDS ARE ALSO BLOWING THROUGH THE ISTHMUS OF TEHUANTEPEC RESULTING IN STORM FORCE WINDS IN THE E PACIFIC REGION. BROKEN TO OVERCAST COLD AIR STRATOCUMULUS CLOUDS ARE NOTED OVER THE GULF SOUTH OF 27N. THESE CLOUDS ARE MOVING SOUTH REACHING THE YUCATAN PENINSULA. LOW-LEVEL CLOUDS POOLED AGAINST THE SIERRA MADRE MOUNTAINS COVER SE MEXICO MAINLY THE STATES OF VERACRUZ AND TABASCO. SURFACE COLD AIR ADVECTION WILL CONTINUE TO AFFECT THE AREA AS A REINFORCING COLD FRONT MOVES INTO THE N GULF WATERS TONIGHT AND TUE FOLLOWED BY AN AREA OF STRONG HIGH PRES. AS A RESULT...WIND SPEEDS ARE EXPECTED TO INCREASE ACROSS THE GULF REGION ON TUE BUT MAINLY ACROSS THE EASTERN HALF DUE TO A TIGHT PRES GRADIENT BETWEEN THIS SFC HIGH PRES AND EXTRATROPICAL LOW OVER THE W ATLC. CARIBBEAN SEA... A STATIONARY FRONT IS OVER THE CARIBBEAN SEA EXTENDING FROM EASTERN CUBA TO NEAR CABO GRACIAS A DIOS NICARAGUA. THE FRONT IS GENERATING SCATTERED MODERATE CONVECTION JUST SOUTH OF THE CAYMAN ISLANDS. THIS SYSTEM IS FORECAST TO REMAIN IN PLACE THROUGH TUE NIGHT. LOOKING AHEAD...A FAST MOVING COLD FRONT WILL SWEEP THROUGH THE GULF OF MEXICO AND MERGE WITH THE STATIONARY FRONT REACHING FROM THE DOMINICAN REPUBLIC TO FAR SW CARIBBEAN BY WED MORNING. INCREASING NLY WINDS WILL FOLLOW THE REINFORCING COLD FRONT AS HIGH PRES BUILDS OVER THE NW CARIBBEAN. THE GFS MODEL SUGGESTS NLY WINDS OF 20 TO 30 KT TUE THROUGH WED. COLD AIR STRATOCUMULUS CLOUDS FROM THE GULF OF MEXICO ARE INVADING WESTERN CUBA AND THE NW CARIBBEAN UNDER A NLY WIND FLOW. THESE WINDS ARE ADVECTING LOW-LEVEL CLOUDS WITH EMBEDDED LIGHT SHOWERS ACROSS THE GULF OF HONDURAS INTO HONDURAS. A TROPICAL WAVE IS OVER THE EASTERN CARIBBEAN. SEE TROPICAL WAVE SECTION. A WEAK 1010 MB LOW HAS DEVELOPED OVER THE SW CARIBBEAN NEAR 10.5N80.5W. VIS SATELLITE IMAGERY REVEALS SOME CYCLONIC TURNING IN THE CLOUD PATTERN SINCE THIS MORNING. PATCHES OF MOISTURE WITH EMBEDDED LIGHT SHOWERS ARE MOVING ACROSS PUERTO RICO...THE VIRGIN ISLANDS AND REGIONAL WATERS. ALOFT...A RIDGE ANCHORED ON A HIGH JUST W OF JAMAICA IS HELPING TO INDUCE CONVECTION ALONG THE FRONTAL BOUNDARY AND OVER THE SW CARIBBEAN. AN UPPER-LEVEL TROUGH EXTENDS FROM HISPANIOLA TO JUST OFFSHORE THE COLOMBIAN COAST NEAR 12N76W. THE COMBINATION OF THIS TROUGH AND A RIDGE OVER N SOUTH AMERICA IS PRODUCING UPPER DIFFLUENCE OVER THE SE CARIBBEAN AND THE WINDWARD ISLANDS ENHANCING CONVECTION DOWN THERE. ATLANTIC OCEAN... A DEEP LAYERED TROUGH OVER THE EASTERN U.S. SUPPORTS A COLD FRONT THAT CROSSES JUST E OF BERMUDA ENTERING THE FORECAST AREA NEAR 31N64W. THE FRONT CONTINUES SW ACROSS THE SE BAHAMAS AND INTO EASTERN CUBA WHERE IT BECOMES STATIONARY. A BAND OF LOW TO MID CLOUDS WITH SCATTERED SHOWERS IS RELATED TO THE FRONT OVER THE ATLC OCEAN. A SURFACE RIDGE CENTERED ON A 1022 MB HIGH NEAR 34N54W COVERS THE CENTRAL ATLANTIC. FARTHER EAST...THERE IS A SFC TROUGH EXTENDING ALONG 31N30W 25N32W 19N40W. SCATTERED SHOWERS ARE WITHIN 90 NM EITHER SIDE OF THE TROUGH AXIS AND N OF 25N. THE REMAINDER OF THE AREA IS UNDER THE INFLUENCE OF A SFC RIDGE. IN THE UPPER LEVELS...A TROUGH/RIDGE/TROUGH/RIDGE PATTERN DOMINATES THE DISCUSSION AREA. A DEEP LAYERED TROUGH IS OVER THE EASTER U.S. AND THE W ATLC. A RIDGE IS OVER THE W-CENTRAL ATLANTIC BETWEEN 50W-65W. AN UPPER-LEVEL TROUGH EXTENDS FROM AN UPPER-LEVEL LOW LOCATED 32N40W TO 15N50W. A JET-STREAM BRANCH WITH CORE WINDS OF 110-130 KT IS ON THE WESTERN SIDE OF THE LOW. ANOTHER MAXIMUM WINDS OF 90 KT IS SE OF THE UPPER LOW PASSING NEAR 21N30W. A RIDGE DOMINATES THE E ATLC AND WEST AFRICA. $$ GR