000 AXNT20 KNHC 062322 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST SUN JAN 06 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 7N12W 1N30W 1N40W 1S48W. SCATTERED MODERATE CONVECTION IS WITHIN 60-90 NM OF THE AXIS BETWEEN 19W-23W...AND BETWEEN 28W-35W. ...DISCUSSION... GULF OF MEXICO... BROAD EAST-SOUTHEASTERLY RETURN FLOW CONTINUES OVER THE GULF OF MEXICO WITH WINDS AVERAGING 10 TO 15 KT OVER THE EASTERN GULF AND 20 KT OVER THE NORTHWEST GULF. CLUSTERS OF STRATOCUMULUS CLOUDS WERE NOTED MAINLY OVER THE GULF W OF 90W STREAMING NORTHWARD IN THE LOW LEVEL FLOW. ISOLATED AREAS OF RAIN WERE OCCURRING ALONG THE LOUISIANA COAST AND IN THE FLORIDA STRAITS. IN THE UPPER LEVELS...BROAD ANTICYCLONIC FLOW DOMINATED THE GULF WITH A RIDGE AXIS ALONG 87W AND EXTENDING NORTHWARD INTO THE TENNESSEE RIVER VALLEY. A WEAK MAINLY MID LEVEL SHORTWAVE TROUGH WAS MOVING ACROSS THE UPPER TEXAS AND LOUISIANA COASTS ON THE BACKSIDE OF THE UPPER RIDGE NOTED ABOVE WITH AN EMBEDDED VORTEX NEAR LAKE CHARLES. MODERATE TO STRONG SUBSIDENCE IS NOTED OVER VIRTUALLY THE ENTIRE GULF. THE SURFACE RETURN FLOW IS FORECAST TO REMAIN IN PLACE OVER MOST OF THE GULF OVER THE NEXT 24 TO 36 HOURS WITH INCREASING CHANCES FOR SHOWER ACTIVITY OVER THE NW GULF ON MONDAY. CARIBBEAN SEA... THE TRADEWINDS OVER THE CARIBBEAN HAVE WEAKENED SLIGHTLY COMPARED TO 24 HOURS AGO. WINDS WERE GENERALLY ON THE ORDER OF 15 TO OCCASIONALLY 20 KT MOST AREAS WITH WINDS OF 25 KT OR GREATER ALONG THE COAST OF COLOMBIA. PATCHES OF BROKEN LOW CLOUDS AND SCATTERED SHOWERS WERE CONFINED TO FAVORED UPSLOPE AREAS OF HONDURAS...NICARAGUA AND BELIZE. FURTHER EAST... ADDITIONAL SHOWER AND ISOLATED THUNDERSTORM ACTIVITY WAS CONCENTRATED OVER PUERTO RICO...THE VIRGIN ISLANDS AND THE ADJACENT ATLANTIC WATERS AND EXTENDING WESTWARD OVER PORTIONS OF THE DOMINICAN REPUBLIC AND WERE ASSOCIATED WITH THE TRAILING END OF A WEAKENING FRONTAL TROUGH. IN THE UPPER LEVELS...BROAD MID TO UPPER LEVEL WEST-SOUTHWESTERLY ANTICYCLONIC FLOW COVERS THE ENTIRE CARIBBEAN SEA WITH MODERATE TO STRONG SUBSIDENCE NOTED OVER THE FAR N CARIBBEAN NEAR CUBA AND HAITI. AN UPPER LEVEL WIND MAXIMA WAS CURVING ACROSS THE CENTRAL CARIBBEAN FROM NICARAGUA EASTWARD JUST SOUTH OF HISPANIOLA TO THE CENTRAL WINDWARD ISLANDS. LITTLE CHANGE IN THE OVERALL PATTERN IS EXPECTED OVER THE NEXT 24 TO 36 HOURS. ATLANTIC OCEAN... A 1033 MB HIGH IS OVER THE WESTERN ATLANTIC NEAR 34N59W AND DOMINATES THE ATLANTIC NORTH AND WEST OF A FRONTAL TROUGH EXTENDING THROUGH 32N37W 23N50W TO JUST NORTHEAST OF PUERTO RICO NEAR 19N64W. A VAST AREA OF BROKEN STRATOCUMULUS CLOUDS ARE NOTED NORTHWEST OF THE FRONT WITH NE SURFACE WINDS OF 15-25 KT. A MID TO UPPER LEVEL TROUGH IS MOVING ACROSS THE NORTHWESTERN ATLANTIC OCEAN...FROM A CYCLONIC CIRCULATION NEAR 33N71W THROUGH 31N73W TO THE NORTHERN BAHAMAS NEAR 27N76W. ANOTHER MID TO UPPER LEVEL TROUGH EXTENDS FROM 31N54W SOUTHWARD TO 19N58W. THIS FEATURE WAS PRODUCING AN AREA OF BROKEN TO OVERCAST MULTILAYERED CLOUDS AND SHOWERS ALONG THE FRONTAL TROUGH GENERALLY FROM 21N TO 25N BETWEEN 50W AND 58W. FURTHER EAST... SURFACE TROUGH EXTENDS FROM 30N38W SOUTHWARD TO 22N41W WITH A 1018 MB LOW PRESSURE CENTER NEAR 24N40W. THE LOW WAS MARKED BY AN AREA OF LOW CLOUDS ARE SPINNING AROUND THE CENTER. ISOLATED SHOWERS ARE POSSIBLE IN THIS AREA. AT THE UPPER LEVELS IN THIS REGION...A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM A CYCLONIC CIRCULATION CENTER NEAR 28N29W TO 21N30W AND 12N34W. STRONGLY DIFLUENT FLOW WAS OCCURRING EAST OF THE TROUGH AXIS MAINLY IN THE AREA FROM 10N THROUGH 35N BETWEEN 18W AND 30W. A HIGH AMPLITUDE RIDGE WITH AXIS THROUGH 32N15W SOUTHWARD ALONG THE WEST COAST OF AFRICA WAS NEARLY STATIONARY WITH A BAND OF STRONG SUBSIDENCE NOTED OVER THE SUB SAHARAN REGION OF AFRICA. $$ COBB