000 AXNT20 KNHC 142349 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST FRI DEC 14 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 7N12W 6N20W 3N30W 1N40W 1S52W. SCATTERED MODERATE CONVECTION IS WITHIN 180-200 NM EITHER SIDE OF THE AXIS BETWEEN 30W-40W. SIMILAR CONVECTION IS WITHIN 60 NM OF N OF AXIS BETWEEN 18W-23W. DISCUSSION... GULF OF MEXICO... A FRONTAL BOUNDARY EXTENDS ACROSS THE FLORIDA PANHANDLE AND THE NORTHERN GULF WATERS ENTERING THE STATE OF TEXAS AS A WARM FRONT THEN CONTINUES OVER NE MEXICO AS A STATIONARY FRONT. THIS FRONT EVENTUALLY CONNECTS TO A DEVELOPING LOW PRESSURE CENTER THAT IS EXPECTED TO PUSH THROUGH THE U.S. GULF COAST STATES AND THE GULF OF MEXICO DURING THE UPCOMING WEEKEND...BRINGING A NOTICEABLE INCREASE IN WINDS AND ROUGH SEAS. A GALE WARNING HAS BEEN POSTED FOR THE W GULF BEHIND THE FRONT FOR NLY WINDS IN THE 25-35 KT RANGE. A MUCH COOLER AND DRIER AIRMASS WILL BE ADVECTED INTO THE REGION WITH THIS FLOW. THIS EVENING...DOPPLER RADAR IS ONLY DETECTING A FEW LIGHT SHOWERS OVER THE UPPER TEXAS COAST AND THE FAR NW CORNER OF THE GULF. MUCH MORE ORGANIZED SHOWER AND TSTM ACTIVITY IS OVER SOUTH-CENTRAL FLORIDA...INCLUDING THE AREA OF LAKE OKEECHOBEE. THIS MOISTURE IS PRIMARILY TRIGGERED BY AN ELONGATED SFC TROUGH THAT EXTENDS NE FROM THE REMNANTS OLGA IN THE NW CARIBBEAN TO CENTRAL FLORIDA. CLOUDINESS WITH EMBEDDED SHOWERS AND ISOLATED TSTMS IS ASSOCIATED WITH THESE FEATURES COVERING MOST THE EASTERN HALF OF THE GULF AND THE YUCATAN PENINSULA. ALOFT...A RIDGE CONTINUES TO DOMINATE THE GULF ANCHORED ON A HIGH OVER NORTHERN CENTRAL AMERICA. CARIBBEAN SEA... OLGA'S REMNANTS IS STILL SPINNING IN THE NW CARIBBEAN NEAR 19.6N85.6W. BUOY 42056 HAS BEEN VERY HELPFUL IN ESTIMATING THE MINIMUM PRESSURE OF THIS LOW THAT IS CURRENTLY 1006 MB. THIS LOW IS EXPECTED TO MOVE NW INTO THE YUCATAN PENINSULA BY SAT...THEN WILL BE ABSORBED BY AN APPROACHING COLD FRONT ENTERING THE NW CARIBBEAN EARLY SUN. THE LOW-LEVEL CIRCULATION IS VERY WELL DEFINED ON SATELLITE PHOTOS WITH A SMALL CLUSTER OF MODERATE CONVECTION JUST EAST OF THE CENTER. A DIFFLUENT PATTERN ALOFT IS PROBABLY ENHANCING THIS CONVECTIVE ACTIVITY. FAIRLY DENSE CLOUD BANDS WITH SCATTERED SHOWERS AND A FEW TSTMS ASSOCIATED WITH THE OVERALL CIRCULATION OF THE REMNANTS OF OLGA ARE AFFECTING WESTERN CUBA...THE YUCATAN PENINSULA...THE NW CARIBBEAN INCLUDING ALSO THE GULF OF HONDURAS AND NORTHERN HONDURAS. THE UPPER LEVEL PATTERN CONSISTS OF A RIDGE ACROSS THE WRN CARIBBEAN ANCHORED ON A HIGH OVER CENTRAL AMERICA AND A TROUGH OVER THE EAST AND CENTRAL PORTIONS OF THE BASIN ENTERING THE AREA FROM THE ATLC. A FAIR AMOUNT OF CLOUDS WITH SCATTERED SHOWERS ARE FOUND SOUTH OF THE TROUGH AXIS AFFECTING BETWEEN THE WINDWARD ISLANDS AND THE ABC ISLANDS. TYPICAL PATCHES OF LOW LEVEL CLOUDS WITH MAINLY LIGHT SHOWERS ARE SEEN OVER THE REMAINDER OF THE BASIN. FRESH TO STRONG EASTERLY TRADE WINDS WILL PERSIST INTO THE WEEKEND. ATLANTIC OCEAN... MOST OF AREA IS FAIRLY TRANQUIL UNDER THE INFLUENCE OF A RIDGE ANCHORED ON A 1026 MB HIGH LOCATED NEAR 29N59W. RATHER TIGHT GRADIENT TO THE S OF THE HIGH IS PRODUCING STRONG ELY TRADES S OF 20N W OF 40W. A SFC TROUGH...PREVIOUSLY MENTIONED IS GENERATING SCATTERED SHOWERS AND TSTMS OVER SOUTH-CENTRAL FLORIDA AND THE FAR NW PORTION OF THE FORECAST REGION. ANOTHER SFC TROUGH ENTERS THE AREA NEAR 31N31W THEN CONTINUES SW TO NEAR 24N42W. A WEAK SFC LOW HAS DEVELOPED WEST OF THE CANARY ISLANDS ALONG THE SFC TROUGH THAT HAS BEEN OUT THERE DURING THE LAST FEW DAYS. NO DEEP CONVECTION IS ASSOCIATED WITH THESES FEATURES. A LONGWAVE MID TO UPPER RIDGE/TROUGH PATTERN CONTINUES TO DOMINATE THE DISCUSSION AREA. THE RIDGE EXTENDS FROM THE CARIBBEAN ENE TO BEYOND 32N36W. THE UPPER-LEVEL TROUGH CONTROLS THE PATTERN MAINLY E OF 5OW AND EXTENDS FROM THE EASTERN ATLANTIC TO THE CENTRAL AND TROPICAL ATLANTIC ALONG 20N...INTO THE EASTERN CARIBBEAN. THE INTERACTION OF THIS TROUGH WITH THE ITCZ IS PRODUCING POCKETS OF MODERATE CONVECTION SOUTH OF 12N AND WEST OF 50W...INCLUDING THE GUYANAS AND PARTS OF VENEZUELA. A JETSTREAM BRANCH WITH CORE WINDS OF 90-110 KT ORIGINATES NEAR THE SE BASE OF THE TROUGH AXIS AND EXTENDS NE CROSSING BETWEEN THE CANARY/CAPE VERDE ISLANDS. WIDESPREAD CLOUDINESS WITH EMBEDDED SCATTERED SHOWERS AND TSTMS ARE SOUTH OF THE JET AXIS. $$ GR