000 AXNT20 KNHC 070545 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST WED 07 JAN 2004 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N INCLUDING NORTHERN SECTIONS OF SOUTH AMERICA. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. SPECIAL FEATURES... NONE. TROPICAL WAVES/ITCZ... AXIS OF ITCZ-RELATED CLOUDS/CONVECTION IS CENTERED ALONG 1N1W 5N15W 2N34W 5N53W. SCATTERED MODERATE WITHIN 30 NM OF AXIS BETWEEN 19W-28W. WIDELY SCATTERED MODERATE WITHIN 60 NM OF AXIS BETWEEN 31W-38W. ISOLATED MODERATE WITHIN 30 NM OF LINE 3N10W 1N18W AND 6N13W 5N19W. MIDDLE/UPPER LEVEL SYNOPTIC FEATURES... MID-LATITUDE TROUGH IS OVER THE EASTERN U.S. THRU THE OHIO VALLEY WITH ITS SOUTHERN EXTENSION STRETCHING INTO GEORGIA. WINDS S OF THE TROUGH OVER THE GULF OF MEXICO ARE RATHER ZONAL WITH PLENTY OF HIGH CLOUDS IN THE CENTRAL AND NORTHERN GULF. THE FRONT WILL LIKELY NOT MAKE TOO MUCH PROGRESS TO THE S AND ONLY DELIVER A GLANCING BLOW OF COOL AIR TO S FLORIDA. STRONG SUBSIDENCE IS OVER THE SE GULF THROUGH THE CARIBBEAN SEA UNDER THE INFLUENCE OVER RIDGING IN THE NW CARIBBEAN. A SECOND UPPER DISTURBANCE CURRENTLY IN W CANADA WILL REINFORCE THE EASTERN TROUGH IN THE NEXT 72 HOURS... SHARPENING THE TROUGH OVER THE GULF OF MEXICO. BASICALLY THE SUBTROPICAL ATLC N OF 20N W OF 40W IS CONTROLLED BY A HIGH NEAR 29N56W WITH ANTICYCLONIC FLOW AND MODERATE SUBSIDENCE IN THE SAME AREA. AN UPPER LOW OVER SOUTHERN HISPANIOLA IS THE ONLY SIGNIFICANT WEATHER FEATURE W OF 40W IN THE DEEP TROPICS WITH A BIT OF ENHANCED RISING MOTION PROVIDING LIFT FOR SHOWERS/TSTMS NEAR PUERTO RICO. OTHERWISE... ZONAL FLOW AND WEAK/MODERATE SUBSIDENCE IS W OF 40W BETWEEN 10N-20N. GENERALLY RIDGING WILL CONTINUE IN THE W-CENTRAL ATLC THOUGH IT SHOULD FLATTEN WITH TIME AS THE TROUGH OVER THE E USA MOVES INTO THE AREA. THE E ATLC HAS A DEEP TROUGH FROM 31N20N SW TO 13N34W WITH ENHANCED MID/HIGH CLOUDINESS E OF THE TROUGH AXIS TO W AFRICA. STRONG SUBSIDENCE IS NEAR THE BASE OF THE TROUGH FROM 15N-22N BETWEEN THE CAPE VERDES TO 40W. A CUT-OFF LOW IS FORECAST TO FORM BETWEEN THE CAPE VERDES AND THE CANARY ISLANDS. SURFACE SYNOPTIC FEATURES... 1041 MB HIGH IS CENTERED OVER NE OKLAHOMA WITH HIGH PRESSURE POURING COLD AIR INTO THE NORTHERN GULF OF MEXICO. AS OF 0300 UTC...COLD FRONT ENTERS THE W ATLC NEAR 32N71W SW ACROSS S FLORIDA CONTINUING TO 23N93W THEN S TO NEAR 19N94W. STATIONARY FRONT IS OVER CNTRL MEXICO ALONG 17N96W 21N100W 30N108W. FRONT IS BASICALLY DEFINED BY AN INCREASE IN LOW CLOUDS ISOLATED SHOWERS AND A COUPLE OF TSTMS OVER THE GULF STREAM. 1027 MB HIGH IS OVER THE CENTRAL ATLC NEAR 28N53W WITH RIDGE AXIS W TO 26N76W AND E TO 31N19W. WEAK TROUGH IS IN THE E ATLC FROM 20N20W TO 26N27W. ISOLATED WEAK/MODERATE WITHIN 90 NM OF 22N25W. SIGNIFICANT CLOUDS/CONVECTION... GULF OF MEXICO... BROKEN TO OCCASIONALLY OVERCAST MULTILAYER CLOUDS ARE N OF THE FRONT BASICALLY FROM KEY WEST TO THE NE TIP OF THE YUCATAN. CARIBBEAN SEA... ISOLATED WEAK/MODERATE IS FROM 17N-20N BETWEEN PUERTO RICO AND HAITI DUE TO A NEARBY UPPER LOW. TROPICAL ATLANTIC... NONE. SUBTROPICAL ATLANTIC... ISOLATED SHOWERS ALONG THE W ATLC COLD FRONT WITH BROKEN LOW CLOUDS BEHIND THE FRONT. $$ BLAKE