000 AXNT20 KNHC 091743 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST WED JAN 09 2008 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 3N10E EQ5W 3N22W 2N40W EQ50W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF THE AXIS BETWEEN 1W-5W AND FROM 3N-7N BETWEEN 33W-42W. SCATTERED MODERATE BUT WEAKENING CONVECTION IS WITHIN 90 NM OF THE AXIS BETWEEN 14W-25W. ...DISCUSSION... GULF OF MEXICO... A COLD FRONT CONTINUES SLOW PROGRESS FROM THE THE WRN FLORIDA PANHANDLE TO 27N94W THEN STATIONARY SWD INTO THE W BAY OF CAMPECHE ENDING NEAR 18N95W. LOW TO MID LEVEL CLOUDINESS AND EMBEDDED SCATTERED SHOWERS ARE WITHIN 150 NM BEHIND THE FRONT. THE UPPER TROUGH SUPPORTING THE FRONT REACHES A BASE OVER THE LOWER MISSISSIPPI VALLEY. NUMERICAL MODELS SHOW THIS UPPER SHORTWAVE MOVING QUICKLY E AND FLATTENING CAUSING THE FRONT TO WEAKEN AND STALL LATER TODAY. AHEAD OF THE FRONT...WEAK SFC HIGH PRES CENTERED OVER OR JUST E OF CENTRAL FLORIDA IS PRODUCING LIGHT TO MODERATE E TO SE WINDS ACROSS THE SE GULF VEERING S NEAR THE FRONT. A FEW PATCHES OF SHOWER ACTIVITY LIE OVER THE MID-GULF FROM 24N-28N BETWEEN 87W-91W. SHIP/BUOY DATA SHOW SOME EVIDENCE OF A WEAK E-W SFC TROUGH ALONG 88W WHICH MAY BE THE CULPRIT FOR THIS PATCHY ACTIVITY. CARIBBEAN SEA... BROAD ELONGATED MID TO UPPER RIDGING ENTRENCHED IN MODERATE TO STRONG SUBSIDENCE DOMINATES THE PATTERN ACROSS THE CARIBBEAN. THE DRIEST AIR ALOFT IS N OF 17N E OF 76W WHERE THE UPPER FLOW IS MOST CONFLUENT TO THE S OF AN UPPER LOW IN THE CENTRAL ATLC. THIS STABLE ENVIRONMENT IS PREVENTING THE TYPICAL LOW-LEVEL CLOUD PATCHES ACQUIRE SIGNIFICANT VERTICAL DEPTH. THE ONLY ORGANIZED CLOUDINESS/SCATTERED SHOWERS IS OVER THE FAR SE CORNER S OF 14N E OF 65W...INCLUDING THE WINDWARD ISLANDS. TRADE WINDS HAVE DECREASED SOME SINCE YESTERDAY BUT REMAIN ON THE STRONG SIDE NEAR THE COAST OF COLOMBIA. THESE WINDS ARE EXPECTED TO SUBSIDE FURTHER OVER THE NEXT DAY OR TWO AS SFC TROUGHING SHIFTS N OF THE AREA. ATLANTIC OCEAN... MAIN FEATURE IN THE ATLC DISCUSSION AREA IS A FAIRLY LARGE UPPER CUT OFF LOW CENTERED NEAR 29N58W. AN ASSOCIATED WWD MOVING SFC TROUGH IS ANALYZED FROM 28N50W TO 20N54W...CAPTURED FAIRLY WELL BY A RECENT ASCAT PASS. COMBINATION OF UPPER DIFFLUENCE TO THE E OF THE UPPER LOW AND LOW-LEVEL CONVERGENCE NEAR THE SFC BOUNDARY IS PRODUCING SCATTERED SHOWERS AND ISOLATED TSTMS FROM 24N-30N BETWEEN 40W-57W. SIMILARLY...DIFFLUENCE ALOFT TO THE E OF THE INDUCED TROUGH BASE IS PRODUCING A SWATH OF MID-HIGH LEVEL CLOUDINESS AND EMBEDDED SHOWERS FROM 12N-22N BETWEEN 38W-53W. THE W ATLC IS VERY TRANQUIL THIS AFTERNOON SUPPORTING BY A SUBSIDENT MID-UPPER RIDGE CENTERED OVERHEAD. THE E ATLC IS ALSO TRANQUIL UNDER PREDOMINATELY ZONAL FLOW ALOFT. VISIBLE IMAGERY SHOWS A PLUME OF CLOUD FREE AIR LIKELY ASSOCIATED WITH SAHARAN DUST...AS NOTED IN THE CIMSS SAL PRODUCT...MOVING W THRU THE CAPE VERDE ISLANDS TO ABOUT 28W. SFC ANALYSIS SHOWS A STRONG BERMUDA-AZORES RIDGE IN CONTROL ENHANCING STRONG NE WINDS TO THE NW OF THE AFOREMENTIONED SFC TROUGH IN THE CENTRAL ATLC. ELY TRADES ARE MODERATE ELSEWHERE. $$ CANGIALOSI