000 AXNT20 KNHC 190547 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST WED DEC 19 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 ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 7N11W 5N20W 1N40W AND INTO SOUTH AMERICA NEAR THE EQUATOR AT 49W. A CLUSTER OF MODERATE CONVECTION IS WITHIN 150 NM N OF THE AXIS BETWEEN 21W-23W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 90 NM N OF AXIS BETWEEN 25W-31W AND BETWEEN 34W-38W. DISCUSSION... GULF OF MEXICO... A RIDGE...ANCHORED ON A 1030 MB HIGH LOCATED OVER THE CAROLINAS DOMINATES THE ENTIRE GULF. LIGHT TO MODERATE E TO SE WINDS ARE BLOWING ACROSS THE GULF WITH THE RETURN FLOW BRING INCREASED MOISTURE TO THE W GULF. ALOFT...STRONG ZONAL FLOW DOMINATES THE REGION. A SUBTROPICAL JETSTREAM WITH CORE WINDS NEAR 120 KT CROSSES THE N GULF WATERS TRANSPORTING ABUNDANT UPPER-LEVEL MOISTURE ACROSS THE AREA...PARTICULARLY N OF 26N. EXPECT THE HIGH PRESSURE TO CONTINUE SHIFTING E OVER THE CAROLINAS WITH THE NEXT COLD FRONT FORECAST TO ENTER THE REGION BY THE WEEKEND. STRONG WINDS AND HIGH SEAS WILL BUILD IN THE GULF FOLLOWING THE FRONTAL PASSAGE. CARIBBEAN SEA... A DISSIPATING SURFACE TROUGH REMAINS OVER THE CARIBBEAN FROM CENTRAL CUBA NEAR 21N77W TO HONDURAS NEAR 15N86W. THIS TROUGH WILL CONTINUE TO WEAKEN AS IT MOVES WESTWARD ACROSS BELIZE AND THE YUCATAN PENINSULA. MOSTLY LOW CLOUDS WITH A FEW LIGHT SHOWERS/DRIZZLE COVER THE CARIBBEAN WEST OF THE TROUGH WITH A CLUSTER OF ENHANCED CONVECTION FROM 17N-19N BETWEEN 83W-84W. SCATTERED MODERATE CONVECTION SUPPORTED BY UPPER LEVEL DIFFLUENCE IS OVER THE WINDWARD ISLANDS E OF 63W. AN UPPER HIGH CENTERED NEAR 14N77W IS CREATING STRONG SUBSIDENCE AND DRY STABLE AIR BETWEEN 63W AND 82W. FRESH ELY TRADES WILL PERSIST THROUGH THURSDAY. ATLANTIC OCEAN... FLOW AROUND THE SFC HIGH OVER THE CAROLINAS IS ADVECTING STRATOCUMULUS CLOUDS OVER THE W ATLC. THE STRONG JET OVER THE NORTHERN PORTION OF THE GULF OF MEXICO EXTENDS ACROSS NORTHERN FLORIDA AND INTO THE W ATLC TRANSPORTING UPPER LEVEL MOISTURE TO THE AREA N OF 26N. FARTHER EAST... A COLD FRONT ENTERS THE REGION NEAR 32N54W AND STRETCHES SW TO 24N69W THEN CONTINUES AS A SFC TROUGH ACROSS THE BAHAMAS AND CENTRAL CUBA INTO THE CARIBBEAN. A 120 NM WIDE BAND OF LOW LEVEL MOISTURE SURROUNDS THE FRONT. A STRONGER BAND OF CONVECTION WITH EMBEDDED ISOLATED SHOWERS/ THUNDERSTORMS EXTENDS UP TO 200 NM AHEAD OF THE FRONT N OF 25N. A DEEP LAYERED TROUGH OVER THE W AND CENTRAL ATLC SUPPORTS THIS FRONT. THE EXTENT OF THIS CONVECTION IS LIMITED DUE TO STRONG SUBSIDENCE AROUND AN UPPER HIGH CENTERED NEAR 26N40W. A CUTOFF 992 MB SFC LOW IS OVER THE E ATLC WITH AN ASSOCIATED COLD FRONT EXTENDING ACROSS THE CANARY ISLANDS TO 21N29W THEN CONTINUES MAINLY WESTWARD AS A DISSIPATING FRONT TO 23N47W WHERE IT BECOMES STATIONARY TO 28N50W. A BAND OF BROKEN LOW CLOUDS DEFINES THE FRONTAL BOUNDARY ON SATELLITE PHOTOS WITH STRATOCUMULUS CLOUDS MOVING IN BEHIND THE FRONT. A WEAKENING 1026 MB HIGH IS BETWEEN THE ABOVE MENTIONED FRONTS NEAR 31N41W DOMINATING THE CENTRAL ATLC. UPPER WESTERLY ZONAL FLOW COVERS THE TROPICS WITH A WEAK JETSTREAM BRANCH EXTENDING WEST TO EAST ALONG 15N-16N. $$ GR/RJW