000 AXNT20 KNHC 240003 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST SAT DEC 23 2006 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA... CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA... NORTHEASTERN 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... 7N11W 4N24W 1N32W EQ53W. SCATTERED MODERATE SHOWERS AND ISOLATED STRONG THUNDERSTORMS WITHIN 180 NM OF AXIS BETWEEN 18W AND 27W. ...DISCUSSION... THE GULF OF MEXICO... DEEPENING UPPER TROUGH IS DIGGING THROUGH WEST TEXAS AND N CENTRAL MEXICO THIS EVENING...PROVIDING SUPPORT TO A 1010 MB SURFACE IN NE MEXICO NEAR MMMY. SWLY FLOW IN THE MID AND UPPER LEVELS AHEAD OF THE ADVANCING TROUGH IS FLOW ACROSS WARM FRONT BOUNDARY EXTENDING FROM LOW CENTER THROUGH S TEXAS AND INTO THE CENTRAL GULF NEAR 26N88W AS A STATIONARY FRONT. WHILE DEEP LAYER MOISTURE IS NOT ESPECIALLY MOIST...WITH PRECIPITABLE WATER VALUES LESS THAN AN INCH OVER S TEXAS...THE OVERRUNNING SW FLOW IS PROVIDING STRONG ISENTROPIC LIFT AND PROMOTING SHOWER GROWTH OVER MUCH OF TEXAS AND IN THE W CENTRAL GULF. SMALL CLUSTER OF SHOWERS AND THUNDERSTORMS NEAR 24N94W ALONG THE BOUNDARY...AIDED BY RIGHT REAR QUADRANT OF EXITING 90 KT JET AXIS. OVER THE EASTERN GULF...COLD FRONT IS EXTENDS FROM CENTRAL FLORIDA NORTH OF TAMPA TO 26N88W WHERE IT BECOMES STATIONARY. FOR TONIGHT AND SUN...UPPER TROUGH WILL SHIFT FROM NRN MEXICO AND INTO THE N CENTRAL GULF...PUSHING ASSOCIATED SURFACE LOW TOWARD THE FLORIDA PANHANDLE. WINDS WILL INCREASE TO GALE FORCE BEHIND THE TRAILING COLD FRONT. WET PATTERN WILL SET UP OVER THE CENTRAL AND EASTERN GULF REGIONS AS WARM FRONT PUSHES N AHEAD OF THE SURFACE LOW. STRONG NLY WINDS WILL PERSIST OVER THE ENTIRE GULF THROUGH EARLY NEXT WEEK AS HIGH PRES BUILDS BEHIND THE FRONT. THE CARIBBEAN SEA... STRONG SURFACE HIGH PRES OVER THE WESTERN ATLC IS MAINTAINING STRONG E TO SE WINDS ACROSS THE CARIBBEAN BASIN. ANIMATED VISIBLE IMAGERY SHOWS ONLY STREAKS OF CUMULUS IN THE ELY FLOW...WITH NO MAJOR CONVECTION NOTED EXCEPT N OF WESTERN PANAMA WHERE WEAK CONVERGENCE IS SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS. ALOFT...MID AND UPPER LEVELS REMAIN FAIRLY DRY. UPPER RIDGE EXTENDS FROM HONDURAS TO CENTRAL CUBA. UPPER TROUGH EXTENDS E-W ALONG 15N OVER THE EASTERN AND CENTRAL CARIBBEAN. 70 TO 90 KT WLY WINDS ARE BRINGING BROKEN CIRRUS DECKS OVER NRN S AMERICA...BETWEEN UPPER TROUGH TO THE N...AND WEAKENING UPPER RIDGE ALONG 5N. NO MAJOR CHANGES ARE EXPECTED THROUGH THE MIDDLE OF NEXT WEEK...AS HIGH PRES TO THE N CONTINUES TO PROMOTE FRESH TO STRONG ELY WINDS ACROSS THE CARIBBEAN. THE EXCEPTION WILL BE A COLD FRONT PUSHING INTO THE EXTREME NW CARIBBEAN NEAR THE YUCATAN MON...FOLLOWED BY STRONG NLY WINDS THROUGH MID WEEK. THE ATLANTIC OCEAN... UPPER RIDGE AXIS EXTENDS FROM 32N61W THROUGH CENTRAL CUBA. 1030 MB SURFACE HIGH CENTERED N OF THE AREA NEAR 37N54W MAINTAINING FRESH TO STRONG ELY WINDS OVER SUBTROPICAL ATLC W OF 50W. STALLING COLD FRONT IS SLOWLY EMERGING OFF THE NE COAST OF FLORIDA. THIS FEATURE WILL STALL OVERNIGHT AND RETREAT NWD AS A WARM FRONT...AHEAD OF STRONG BAROCLINIC SYSTEM PUSHING THROUGH THE GULF OF MEXICO. FURTHER E...ORIENTED UPPER TROUGH EXTENDS N-S ALONG 36W. FROM THE BASE OF THIS TROUGH...ANOTHER UPPER TROUGH EXTENDS MORE E-W INTO THE CARIBBEAN BASIN. AFTERNOON QUIKSCAT IMAGERY OUTLINES A COLD FRONT IS PUSHING THROUGH THE N CENTRAL ATLC ASSOCIATED WITH THE UPPER TROUGH...WHICH WILL QUICKLY ABSORB A COUPLE OF WEAK BOUNDARIES AHEAD OF IT...INCLUDING A WEAK TROUGH NEAR 34W. TO THE E...LARGE FIELD OF STRATO CUMULUS CLOUDS OFF IBERIAN AND MOROCCAN COASTLINES...ASSOCIATED WITH STABLE AIRMASS UNDER UPPER RIDGE AXIS ALONG 18W. OVER THE TROPICAL ATLC S OF 20N...UPPER LEVEL ANTICYCLONIC DIFFLUENCE ALONG 5N IS ENHANCING SCATTERED CONVECTION ALONG THE ITCZ AS NOTED ABOVE. QUIKSCAT IMAGERY SHOWS MAINLY LIGHT TO MODERATE NELY FLOW ACROSS THE REGION. $$ CHRISTENSEN