000 AXNT20 KNHC 201722 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST SAT JAN 20 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...THE ITCZ... AXIS CENTERED ALONG 8N13W 5N20W 3N30W 2N40W CROSSING THE EQUATOR AT 46W. ISOLATED SHOWERS/TSTMS NOTED WITHIN 60 NM OF THE AXIS BETWEEN 27W-31W. OVERALL THOUGH...VERY LITTLE IN THE WAY OF DEEP CONVECTION EXISTS WITHIN SEVERAL HUNDRED NM OF THE AXIS. ...DISCUSSION... THE GULF OF MEXICO... SUBTROPICAL JET CONTINUES TO SPREAD MID TO UPPER MOISTURE FROM THE NE PAC THROUGH THE DEEP SOUTH...CLIPPING THE NRN GULF WATERS. EXTREMELY DRY MID TO UPPER AIR IS SEEN IN WV IMAGERY SE OF A LINE FROM VERACRUZ MEXICO TO TAMPA BAY FLORIDA. OVERALL THE MID TO UPPER PATTERN REMAINS DOMINATED BY RIDGING...THOUGH A WEAK UPPER TROUGH IS EMBEDDED IN THE ANTICYCLONIC FLOW WITH THE AXIS EXTENDING NNE FROM THE ISTHMUS OF TEHUANTEPEC TO NEAR 25N90W. SFC FRONTAL PATTERN REMAINS A LITTLE DIFFICULT TO ANALYZE. AS OF 1500 UTC...A WEAK 1017 MB LOW IS LOCATED OFF OF SE TEXAS THAT HAS A WARM FRONT EXTENDING E TO NEAR 27N87W. A DYING STATIONARY FRONT THEN EXTENDS FROM THIS POINT TO NEAR NAPLES FLORIDA. A LINGERING STATIONARY FRONT ALSO EXISTS S OF THE SFC LOW TO THE CENTRAL BAY OF CAMPECHE. THE WRN GULF PORTION OF THE FRONT IS MUCH EASIER TO ANALYZE...IN ADDITION TO THE WIND SHIFT THERE IS A 26F DEG TEMP/22F DEG DEWPOINT GRADIENT BETWEEN BROWNSVILLE TX AND BUOY 42002. THERE IS ALSO QUITE A DEWPOINT GRADIENT ACROSS THE FLORIDA PENINSULA BUT A WEAK SFC RIDGE AXIS IS EVIDENT WHICH HAS MADE THE FRONTAL PLACEMENT DIFFICULT. BROKEN TO OVERCAST LOW CLOUD/LIGHT RAIN STILL EXISTS BEHIND THE FRONT W OF 85W. FEW TO SCATTERED LOW CLOUDS NOTED AHEAD OF THE FRONT. A CONVERGENT LINE WITH SHOWERS IS SEEN OFF SE FLORIDA AND IN THE STRAITS OF FLORIDA. SFC LOW OFF SE TX EXPECTED TO MOVE NE TOWARDS NW MISSISSIPPI BY TOMORROW MORNING. SFC HIGH PRESSURE N/NE OF THE AREA EXPECTED TO TAKE OVER THE PATTERN ON SUN EXCEPT FAR NW PORTION WHERE A QUASI STATIONARY FRONTAL BOUNDARY LINGERS. WINDS WILL VEER SE 10-20 KT AHEAD OF THIS BOUNDARY WITH LIGHTER NE WINDS BEHIND THE FRONT. THE CARIBBEAN SEA... DRY MID TO UPPER AIR IS ROTATING AROUND AN UPPER RIDGE OVER THE CARIBBEAN THIS AFTERNOON. THIS CONTINUES TO SUPPRESS CONVECTION ACROSS THE AREA. AT THE SFC...15-20 KT TRADES CONTINUE S OF HIGH PRES...EXCEPT 25-30KT NEAR THE COLOMBIAN COAST. THIS FETCH CONTINUES TO PRODUCE MODERATE TO STRONG SURF ALONG THE CARIBBEAN COAST OF COSTA RICA AND PANAMA. THE TRADES ARE ADVECTING TYPICAL PATCHES OF LOW LEVEL MOISTURE WITH EMBEDDED SHOWERS WWD. THE MOST SIGNIFICANT AREA OF MOISTURE/SHOWERS IS JUST OFFSHORE THE NICARAGUAN COAST AT THE MOMENT. GFS LOW TO MID LEVEL MOISTURE FIELDS ARE PICKING UP ON THIS AND SUGGEST THE AREA WILL GAIN SOME STEAM AS IT PUSHES INTO NICARAGUA TONIGHT. MODERATE TO FRESH TRADES CONTINUE THROUGH MON. THE ATLANTIC OCEAN... UPPER RIDGING OVER THE SW N ATLC CONTINUES TO ADVECT A BAND OF MOISTURE/HIGH CLOUDS EWD OFF THE SE U.S. COAST INTO THE W AND CENTRAL ATLC. VERY DRY UPPER AIR...HOWEVER...IS SW OF A LINE FROM THE NW BAHAMAS TO LEEWARD ISLANDS. QUASI STATIONARY SFC FRONT ENTERS THE AREA AT 32N58W AND CONTINUES WSW TO SE FLORIDA. THERE IS A RAGGED LOW CLOUD LINE ASSOCIATED WITH THIS FRONT...IN ADDITION TO NOTABLE SPEED CONFLUENCE AS SHOWN IN THIS MORNINGS QUIKSCAT PASS. A WEAK 1019 MB SFC HIGH IS SE OF THE FRONT NEAR 25N58W. THIS HIGH EXPECTED TO GET TAKEN OVER BY STRONGER HIGH PRES RIDGING SE OFF THE MID ATLC COAST BEHIND THE FRONT THROUGH SUN. AN UPPER TROUGH EXTENDS S THROUGH THE CENTRAL ATLC WATERS ALONG 40W...WITH A 1012 MB SFC REFLECTION NEAR 27N44W. THERE ARE ACTUALLY 4 LOW LEVEL SWIRLS NOTED FROM 20N-29N BETWEEN 40W-57W...BUT FOR THE SAKE OF CONTINUITY AND THE FACT THIS IS A SYNOPTIC MAP...HAVE OPTED TO CONTINUE TRACKING THE MOST SIGNIFICANT OF THESE. REGARDLESS...THE PARENT BROAD LOW IS EXPECTED TO GET ABSORBED INTO THE MUCH STRONGER STORM TO DEVELOP SE OF THE CANADIAN MARITIMES LATE TONIGHT NEAR 40N52W. UPPER RIDGING IS TAKING OVER THE E ATLC...AS THE UPPER LOW WE'VE BEEN TRACKING JUST N OF THE CANARY ISLANDS MOVES OUT OF THE AREA. UPPER WLY FLOW WITH THE RIDGE IS ADVECTING A PLUME OF MOISTURE WITH POSSIBLE SHOWERS EWARD FROM 7N-22N BETWEEN 40W AND AFRICA. LIGHT TO MODERATE E TO NE SFC WINDS ARE BEING FELT IN THE E ATLC AS WELL...S OF HIGH PRESSURE RIDGING FROM SW EUROPE. $$ WILLIS