000 AXNT20 KNHC 011746 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST MON DEC 01 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. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED ALONG 8N8W 5N30W 2N51W. SCATTERED MODERATE CONVECTION IS FROM 4N-8N BETWEEN 18W-28W. ISOLATED MODERATE CONVECTION IS FROM 4N-9N BETWEEN 43W-50W. ...DISCUSSION... GULF OF MEXICO... A VIGOROUS DEEP LAYER TROUGH IS OVER THE ERN CONUS DIPPING INTO THE CENTRAL AND WRN GULF. THIS TROUGH SUPPORTS TWO COLD FRONTS. ONE EXTENDS ACROSS THE W ATLC WATERS INTO THE STRAITS OF FLORIDA ACROSS FAR WRN CUBA INTO THE NW CARIBBEAN SEA. SCATTERED SHOWERS ARE ACROSS SRN FLORIDA...THE SE GULF AND YUCATAN CHANNEL. A REINFORCING SURFACE COLD FRONT EXTENDS FROM THE FLORIDA BIG BEND NEAR 29N83W SW TO 27N85W AND 24N91W. AS COOLER AIR BEHIND THE FRONT IS ADVECTED OVER RELATIVELY WARMER GULF WATERS...LOW LEVEL INSTABILITY IS GENERATING SCATTERED STRATOCUMULUS CLOUDS IN THE WAKE OF THE FRONT N OF 24N. THE PRESENCE OF DEEP LAYER DRY AIR AND STABLE CONDITIONS ARE PREVENTING THE DEVELOPMENT OF ANY DEEP CONVECTION ACROSS THE GULF REGION. A SURFACE RIDGE EXTENDS SE FROM A 1026 MB SURFACE HIGH CENTERED OVER N/CENTRAL MEXICO NEAR 28N103W. N-NE SURFACE FLOW AROUND THIS RIDGE IS GENERATING BROKEN TO OVERCAST CLOUDS INTO THE BAY OF CAMPECHE WITH POSSIBLE ISOLATED SHOWERS S OF 22N. CARIBBEAN SEA... THE AFOREMENTIONED COLD FRONT ASSOCIATED WITH THE DEEP LAYER TROUGH ACROSS THE GULF REGION EXTENDS ACROSS WRN CUBA AND INTO THE NW CARIBBEAN AS A STATIONARY BOUNDARY TO NEAR 16N86W. LOW LEVEL CONVERGENCE WITH THIS FRONT AND INSTABILITY ALONG AND AHEAD OF THE FRONT ARE SUPPORTING SCATTERED SHOWERS AND TSTMS FROM 20N ACROSS CUBA AND INTO THE W ATLC BETWEEN 80W-83W. THIS ACTIVITY IS BEING ENHANCED BY UPPER LEVEL DIVERGENCE AS AN UPPER RIDGE IS ANCHORED IN THE CENTRAL AND ERN CARIBBEAN CENTERED OVER HISPANIOLA. A 1012 MB SURFACE LOW IS CENTERED E OF NICARAGUA NEAR 14N82W. LOW LEVEL CONVERGENCE NEAR THIS LOW IS SUPPORTING SCATTERED SHOWERS/ISOLATED TSTMS FROM 10N-16N BETWEEN 80W-83W. THIS ACTIVITY IS ALSO BEING ENHANCED BY THE UPPER DIFFLUENT PATTERN IN PLACE OVER THE SW CARIBBEAN WITH MOIST SOUTHWESTERLY FLOW ALOFT. ELSEWHERE...LOW-LEVEL CYCLONIC CURVATURE IS OBSERVED IN THE WIND FIELD AND IS INDUCING SCATTERED SHOWERS FROM 12N-16N BETWEEN 60W-66W ACROSS THE ERN CARIBBEAN USHERED IN ON FRESH EASTERLY TRADES. ATLANTIC OCEAN... A VIGOROUS DEEP LAYER TROUGH IS OVER THE ERN CONUS WITH STRONG UPPER LEVEL DIVERGENCE E OF THE TROUGH ACROSS THE W ATLC WATERS. THIS THOUGH SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N74W AND EXTENDS SW TO GRAND BAHAMA ISLAND AND ACROSS THE FLORIDA STRAITS TO WRN CUBA. SCATTERED SHOWERS AND TSTMS ARE WITHIN 150 NM E OF THE FRONT...INCLUDING THE NW BAHAMAS AND CENTRAL CUBA. TO THE E...A 1028 MB SURFACE HIGH IS CENTERED NEAR 30N56W WITH SUPPORT FROM AN AMPLIFIED UPPER RIDGE CENTERED OVER HISPANIOLA WHICH EXTENDS NE BEYOND 32N63W. ACROSS THE E ATLC...A SURFACE LOW IS CENTERED NEAR 27N34W WITH A SURFACE TROUGH EXTENDING SW FROM THE LOW ALONG 24N34W 15N40W TO 12N46W. THIS SURFACE FEATURE IS SUPPORTED BY SHARP UPPER LEVEL TROUGHING THAT EXTENDS FROM AN UPPER LOW NORTH OF THE REGION NEAR 37N37W. THE UPPER TROUGH AXIS IS ALONG 30N39W 20N45W TO 13N56W. LOW LEVEL CONVERGENCE NEAR THE SURFACE TROUGH IS GENERATING SCATTERED SHOWERS WITHIN 90 NM E OF THE FEATURE S OF 22N WHILE AN AREA OF SCATTERED SHOWERS IS FROM 22N-32N BETWEEN 26W-33W. ELSEWHERE...AN UPPER RIDGE IS S OF 20N BETWEEN THE AFRICAN COAST AND 33W...WITH AN UPPER HIGH NEAR 8N13W. UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THESE UPPER FEATURES ARE ENHANCING CONVECTION IN THE VICINITY OF THE ITCZ E OF 33W. $$ HUFFMAN