000 AXNT20 KNHC 101743 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST SUN FEB 10 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... THE ITCZ AXIS IS CENTERED ALONG 7N10W 2N20W 1N30W EQUATOR AT 45W INTO NE BRAZIL. WIDELY SCATTERED MODERATE CONVECTION IS WITHIN 100 NM NORTH OF BETWEEN 27W-32W. SIMILAR CONVECTION IS WITHIN 120 NM S OF AXIS BETWEEN 16W-19W. ...DISCUSSION... GULF OF MEXICO... A SHORTWAVE TROUGH EXTENDS FROM A VORT MAX CENTERED ABOUT 180 NM OF CAPE HATTERAS NEAR 35N72W SW TO A BASE OVER N FLORIDA AND THE ADJACENT NE GULF. MODERATE TO STRONG UPPER LEVEL SUBSIDENCE IS SWEEPING OFF THE SE COAST AND EXTENDS WWD ACROSS MUCH OF THE NORTH GULF STATES/WATERS. THE TROUGH IS PROVIDING SUPPORT FOR A RAPIDLY MOVING COLD FRONT THAT LIES OVER THE W ATLC ALONG 32N71W 28N75W 27N78W. THIS FRONT IS EXPECTED TO OVERTAKE A WEAKENING QUASI-STATIONARY FRONTAL TROUGH CURRENTLY EXTENDING ACROSS THE NW BAHAMAS...THE STRAITS OF FLORIDA AND THE SE PORTION OF THE GULF...VERY CLOSE TO WESTERN CUBA. DOPPLER RADAR SHOWS SCATTERED SHOWERS AND ISOLATED TSTMS ALONG THE FRONTAL TROUGH BETWEEN SOUTH FLORIDA AND WESTERN CUBA. PART OF THIS ACTIVITY IS AFFECTING THE N COAST OF PINAR DEL RIO AND THE CITY OF HAVANA. STRONG HIGH PRES OVER THE CENTRAL CONUS EXTENDS A RIDGE OVER THE NORTHERN GULF WATERS AND N-CENTRAL FLORIDA WITH A COLD AIRMASS. AS THIS HIGH CONTINUES TO GRIP THE REMAINDER OF THE GULF/STATE OF FLORIDA EXPECT AN INCREASE IN WINDS AND SEAS THIS AFTERNOON THROUGH MONDAY. BRISK NE TO E WINDS WILL BLOW...PARTICULARLY ACROSS THE STRAITS OF FLORIDA AND THE SE GULF...WITH WINDY CONDITIONS OVER SOUTH FLORIDA FOR THE REST OF TODAY. A SFC TROUGH IS OVER THE WESTERN GULF AND THE BAY OF CAMPECHE GENERATING SCATTERED SHOWERS AND TSTMS. UPPER DIFFLUENCE BETWEEN A SHORTWAVE TROUGH OVER NW MEXICO AND A RIDGE OVER THE CARIBBEAN SEA IS ENHANCING THIS ACTIVITY. CARIBBEAN SEA... AN UPPER RIDGE EXTENDS ACROSS THE W-CENTRAL CARIBBEAN FROM PANAMA TO HISPANIOLA AND CONTINUES NEWD INTO THE SUBTROPICAL ATLC. AN UPPER LEVEL TROUGH/SHEAR AXIS IS UNDERCUTTING THE RIDGE AND EXTENDS ACROSS THE NE WINDWARD ISLANDS NEAR GUADELOUPE WWD JUST TO THE S OF PUERTO RICO AND HISPANIOLA. MODERATE TO STRONG SUBSIDENCE DOMINATES MOST OF THE BASIN WITH SOME UPPER LEVEL MOISTURE OVER THE YUCATAN PENINSULA AND THE NW CARIBBEAN DUE TO STRONG SWLY FLOW ALOFT. THIS SUBSIDENCE IS LIMITING ANY THUNDERSTORMS ACROSS THE AREA WITH THE EXCEPTION OF A SMALL CLUSTER OF ACTIVITY IN THE GULF OF HONDURAS NEAR ROATAN ISLAND. SURFACE RIDGE N OF AREA COUPLED WITH THE COLOMBIAN LOW IS PRODUCING A RATHER TIGHT PRESSURE GRADIENT OVER THE SW CARIBBEAN RESULTING IN MODERATE/STRONG EASTERLY TRADE WINDS ACROSS THE AREA. A 1048 UTC QUIKSCAT PASS INDICATED 25-30 KT WINDS ALONG THE COAST OF COLOMBIA. THE TRADE WINDS ARE USHERING IN SOME LOW LEVEL CLOUDS AND WIDELY SCATTERED LOW TOPPED SHOWERS. DOPPLER RADAR REVEALS SOME OF THIS SHOWERS MOVING ACROSS THE UK/US VIRGIN ISLANDS INTO NE PUERTO RICO...INCLUDING THE SAN JUAN METROPOLITAN AREA. ATLANTIC OCEAN... AS PREVIOUSLY MENTIONED...THE UPPER LEVEL SHORTWAVE TROUGH MOVING OFF THE MID-ATLANTIC COAST IS PROVIDING SOME SUPPORT FOR A COLD FRONT THAT ENTERS THE AREA NEAR 32N71W THEN CONTINUES SW TO 27N78W. THIS FRONT IS FORECAST TO OVERTAKE THE FRONTAL TROUGH THAT IS CURRENTLY WITHIN AROUND 80 NM AHEAD OF IT. MOST OF THE W-CENTRAL ATLC IS DOMINATED BY AN EXPANSIVE DEEP LAYERED RIDGE AND EMBEDDED ANTICYCLONE NEAR 25N46W AT 500 MB. THE SURFACE RIDGE IS ANCHORED BY A 1025 MB HIGH NEAR 28N50W. AN UPPER LEVEL TROUGH OVER THE FAR E ATLC SUPPORTS A 1012 MB LOW LOCATED JUST N OF THE CANARY ISLANDS NEAR 29N16W. A TROUGH...REMNANTS OF A FRONTAL BOUNDARY EXTENDS FROM THE LOW ALONG THE COAST OF WESTERN SAHARA TO 21N19W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE AROUND THE LOW. AN E/W UPPER RIDGE EXTENDS ACROSS THE TROPICAL ATLC ALONG 4N/5N TO 40W AND A WEAKENING JETSTREAM WITH WINDS OF 90 TO 110 KT IS ALONG THE N PERIPHERY OF THE RIDGE FROM 15N30W TO INLAND OVER W AFRICA ACROSS MAURITANIA. SATELLITE IMAGERY SHOWS A BAND OF TRANSVERSE HIGH CLOUDS ASSOCIATED WITH THIS JET. $$ GR/HC