000 AXNT20 KNHC 151118 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST SAT DEC 15 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 1045 UTC ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 6N8W 5N27W 6N38W 3N51W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 150 NM S OF THE ITCZ AXIS FROM 30W-46W...WITHIN 90 NM N OF THE ITCZ AXIS FROM 30W-35W...AND WITHIN 150 NM N OF THE ITCZ AXIS 35W-44W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 90 NM OF THE ITCZ AXIS FROM 17W-30W. DISCUSSION... GULF OF MEXICO... A DISSIPATING STATIONARY FRONT IS ALONG THE N GULF COAST EXTENDING ACROSS SE GEORGIA INTO THE GULF JUST E OF PANAMA CITY FLORIDA S OF LOUISIANA COAST INTO E TEXAS NEAR HOUSTON AS A WARM FRONT. THIS FRONT REMAINS EMBEDDED WITHIN SOME RATHER DRY AIR SO NO SHOWER ACTIVITY IN THE GULF. HOWEVER...A FRONTAL BOUNDARY INLAND OVER S TEXAS IS APPROACHING THE TEXAS COAST WITH SOME ISOLATED SHOWERS WITHIN 60 NM OF THE TEXAS COAST AND NE MEXICO N OF 25N. THE REMNANTS OF OLGA ARE IN THE W CARIBBEAN ALONG THE COAST OF THE YUCATAN EXTENDING A SURFACE TROUGH NNE THROUGH THE YUCATAN CHANNEL NEAR 22N86W OVER FLORIDA NEAR TAMPA GENERATING A BROAD AREA OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 29N E OF 90W ACROSS FLORIDA. A BROAD UPPER RIDGE EXTENDS FROM THE W CARIBBEAN THROUGH THE YUCATAN CHANNEL AND ACROSS FLORIDA INTO THE W ATLC COVERING THE ENTIRE GULF ENHANCING THE ACTIVITY ASSOCIATED WITH THE SURFACE TROUGH ABOVE. CARIBBEAN SEA... THE REMNANTS OF OLGA...A 1006 MB LOW...IS IN THE W CARIBBEAN ALONG THE COAST OF THE YUCATAN NEAR 20.5N86.5W EXTENDING A SURFACE TROUGH NNE INTO THE GULF OF MEXICO THROUGH THE YUCATAN CHANNEL NEAR 22N86W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 19N W OF 84W. THIS LOW IS EXPECTED TO CONTINUE TO MOVE NW AND IS CURRENTLY MOVING INTO THE GULF OF MEXICO AND WILL MERGE WITH AN APPROACHING FRONTAL BOUNDARY LATE TODAY INTO TONIGHT. AN UPPER HIGH IS INLAND OVER CENTRAL AMERICA EXTENDING AN UPPER RIDGE THROUGH THE YUCATAN CHANNEL INTO THE GULF OF MEXICO COVERING THE W CARIBBEAN W OF 78W. AN UPPER TROUGH EXTENDS FROM PUERTO RICO SW TO AN UPPER LOW ALONG THE N COAST OF COLOMBIA COVERING THE REMAINDER OF THE CARIBBEAN. THE UPPER AIR OVER MOST OF THE CARIBBEAN IS MAINLY DRY WITH SOME WEAK UPPER DIVERGENCE GENERATING SCATTERED SHOWERS WITHIN 75 NM OF LINE FROM 12N81W TO 20N85W AND SOME SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS S OF 11N FROM COLOMBIA TO COSTA RICA. ATLANTIC OCEAN... AN UPPER RIDGE ANCHORED OVER CENTRAL AMERICA EXTENDS ACROSS FLORIDA INTO THE W ATLC TO NEAR 28N74W COUPLED WITH A FRONTAL BOUNDARY JUST N OF THE REGION IS GENERATING SCATTERED SHOWERS N OF 27N W OF 71W TO THE COAST OF FLORIDA/GEORGIA. THE UPPER TROUGH THAT EXTENDS FROM PUERTO RICO COVERS THE REMAINDER OF THE W ATLC WITH DRY STABLE AIR. BROAD UPPER TROUGH COVERS THE CENTRAL AND E ATLC E OF 45W WITH THE SURFACE TROUGH EXTENDING INTO THE E ATLC THROUGH 32N29W SW TO 23N45W. A 1015 MB SURFACE LOW IS EMBEDDED WITHIN THIS UPPER TROUGH W OF THE CANARY ISLANDS NEAR 27N21W WITH A SURFACE TROUGH EXTENDING SW TO 21N31W AND E ACROSS THE CANARY ISLANDS TO OVER S MOROCCO AFRICA BUT DUE TO THE DRY STABLE AIR ONLY WIDELY ISOLATED LOW LEVEL SHOWERS ARE WITHIN 120 NM SE OF THE SURFACE LOW. UPPER WESTERLY ZONAL FLOW COVERS THE TROPICS AND A JET STREAM WITH ESTIMATED WINDS OF 80 TO 100 KT EXTENDING ALONG 15N45W TO THE CAPE VERDE ISLANDS THEN NE TO OVER AFRICA NEAR 21N16W. OTHERWISE THE ATLC REMAINS RATHER TRANQUIL TONIGHT WITH SURFACE RIDGE DOMINATING THE AREA FROM 40W-75W ANCHORED BY A 1026 MB HIGH NEAR 29N56W. $$ WALLACE