000 AXNT20 KNHC 131100 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST SAT JAN 13 2007 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG THE 1N1W 3N27W 2N44W 3N53W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM N OF THE ITCZ AXIS FROM 25W-29W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGE DOMINATES THE GULF AND THE E US ANCHORED BY AN UPPER HIGH JUST N OF THE YUCATAN CHANNEL NEAR 23N85W. TROPICAL MOISTURE FROM THE E PACIFIC REGION CROSSES MEXICO INTO THE CENTRAL PLAIN STATES WITH THE DEEP LAYERED TROUGH OVER THE DESERT SW AND THE NEXT FRONTAL SYSTEM EXPECTED IN THE GULF ON MON CURRENTLY OVER CENTRAL TEXAS. A BROAD SURFACE RIDGE EXTENDS FROM THE W ATLC ACROSS THE SE US AND THE GULF OF MEXICO E OF 94W WITH MODERATE/STRONG EASTERLY SURFACE WINDS AND RETURN FLOW BANKING LOW LEVEL CLOUDS WITH ISOLATED SHOWERS FROM THE W BAY OF CAMPECHE TO ALONG THE TEXAS COAST. WIDELY ISOLATED SHOWERS ARE OBSERVED IN THE STRAITS OF FLORIDA AND THE SE GULF ATTRIBUTED TO THE SAME EASTERLY FLOW AROUND THE SURFACE RIDGE. CARIBBEAN SEA... UPPER RIDGE ANCHORED IN THE GULF OF MEXICO COVERS THE W CARIBBEAN W OF 75W. DEEP LAYERED TROUGH OVER THE W AND CENTRAL ATLC DIPS OVER THE NE CARIBBEAN EXTENDING FROM THE MONA PASSAGE SW TO 16N74W. THE STATIONARY FRONT ASSOCIATED WITH THIS DEEP LAYERED TROUGH EXTENDS FROM THE W/CENTRAL ATLC TO THE WINDWARD PASSAGE. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE N OF 18N FROM 65W-70W INCLUDING THE VIRGIN ISLANDS...PUERTO RICO...AND PORTIONS OF HISPANIOLA. AN UPPER RIDGE OVER SOUTH AMERICA EXTENDS OVER THE SE CARIBBEAN INTO THE W TROPICAL ATLC. STRONG SUBSIDENCE AND DRY AIR DOMINATE THE W CARIBBEAN W OF 70W WITH POSSIBLE ISOLATED SHOWERS OVER THE SE CARIBBEAN. STRONG TRADE WINDS CONTINUE ACROSS THE REGION AS HIGH SURFACE PRESSURE REMAINS IN CONTROL OF THE W ATLC. ATLANTIC OCEAN... BROAD UPPER RIDGE OVER THE GULF OF MEXICO EXTENDS ACROSS FLORIDA INTO THE FAR W ATLC W OF 75W. DEEP LAYERED TROUGH COVERS THE THE REMAINDER OF THE W ATLC INTO THE CENTRAL ATLC WITH THE ASSOCIATED STATIONARY FRONT EXTENDING THROUGH 32N46W ALONG 24N57W TO THE WINDWARD PASSAGE. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 90 NM OF A LINE FROM 22N57W TO THE N CARIBBEAN ISLANDS NEAR THE MONA PASSAGE. A STRONG SURFACE RIDGE REMAINS ANCHORED OVER THE W ATLC BY A 1034 MB HIGH NE OF BERMUDA NEAR 35N60W EXTENDING OVER THE SE US AND THE GULF OF MEXICO. NARROW UPPER RIDGE EXTENDS FROM 22N51W NE TO BEYOND 32N33W. A DEEP LAYERED TROUGH IS OVER THE E ATLC CENTERED FROM A N/S ELONGATED UPPER LOW NEAR 32N22W COVERS THE REMAINDER OF THE ATLC WITH A SURFACE TROUGH EXTENDING FROM 23N26W THROUGH A 1019 MB LOW NEAR 28N27W TO 34N25W. AFRICAN DUST IS OBSERVED ON THE FIRST VISIBLE SATELLITE IMAGES S OF 20N E OF 32W AND BEING DRAWN NORTHWARD BY THE UPPER TROUGH BETWEEN THE CANARY ISLANDS AND THE SURFACE TROUGH/LOW. $$ WALLACE