000 AXNT20 KNHC 091801 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST THU NOV 09 2006 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...WEATHER OBSERVATIONS...RADAR... AND METEOROLOGICAL ANALYSIS. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1745 UTC. ...TROPICAL WAVES... A BROAD ATLANTIC OCEAN TROPICAL WAVE IS ALONG 45W S OF 15N MOVING W NEAR 15 KT. THE WAVE IS S OF AN ELONGATED UPPER TROUGH WHICH IS SHEARING THE HIGH CLOUDS ALONG THE NORTHERN PORTION OF THE WAVE TO THE NE. HOWEVER...CYCLONIC TURNING IS STILL EVIDENT IN THE LOWER TO MID CLOUD FIELD UNDERNEATH THESE HIGHER CLOUDS. A FAIRLY SIGNIFICANT AMOUNT OF SHOWERS/TSTMS SURROUNDS THIS WAVE WITH NUMEROUS MODERATE/ISOLATED STRONG CONVECTION IS FROM 3N-12N BETWEEN 40W-50W. THE TROPICAL WAVE THAT WAS PREVIOUSLY ALONG 56W/57W S OF 14N HAS BEEN REMOVED...AS THERE HAVE BEEN NO IDENTIFIABLE TROPICAL WAVE CHARACTERISTICS IN SOME TIME...WITH ITS RECENT PLACEMENT BASED SOLELY ON CONTINUITY. THE ITCZ HAS ALSO BEEN ADJUSTED FURTHER S TO THE COAST OF FRENCH GUIANA WITH NE FLOW OBSERVED OFF MUCH OF NE SOUTH AMERICA. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 10N14W 7N30W 8N43W 8N48W TO THE FRENCH GUIANA COAST NEAR 5N53W. SCATTERED MODERATE CONVECTION IS FROM 3N-10N BETWEEN 31W-40W...AND OVER COASTAL NE SOUTH AMERICA AND THE ADJACENT ATLC WATERS FROM 1N-7N BETWEEN 50W-53W. ...DISCUSSION... GULF OF MEXICO... MOSTLY FAIR/DRY WEATHER DOMINATES THE GULF THIS AFTERNOON...WITH VERTICALLY STACKED HIGH PRESSURE RIDGING AND EXTENSIVE DRY/STABLE AIR DOMINATING. THE ONLY MOISTURE SEEN IN THE GULF IS OVER THE FAR W/SW PORTION...WHERE DEBRIS MOISTURE FROM RECENTLY UPGRADED T.S. ROSA IN THE EPAC SPREADING E/NE WITH UPPER W/SW FLOW. RETURN SFC FLOW ALSO IN THE W GULF...W OF THE WEAK 1013 MB SFC HIGH OVER THE NORTH CENTRAL GULF NEAR 27N88W. THE HIGH WILL CONTINUE SLIDING ENE TOWARDS THE APALACHEE BAY THROUGH TOMORROW...WITH THE NEXT COLD FRONT ENTERING THE NW PORTION BY SATURDAY MORNING. SEE MIAOFFNT4 FOR DETAILS. CARIBBEAN SEA... A LINGERING COLD FRONT BOUNDARY EXTENDS THROUGH THE NW CARIBBEAN FROM ERN CUBA TO THE GULF OF HONDURAS. NO DEEP CONVECTION IS NOTED NEAR THIS BOUNDARY...AND INSTEAD IS MARKED BY A LINE OF LOWER CLOUDS WITH CONFLUENT LOW LEVEL FLOW. THE ASSOCIATED UPPER TROUGH JUST OFF THE EASTERN SEABOARD CLIPS THE NRN CARIBBEAN WATERS NEAR CUBA AND HISPANIOLA. A PAIR OF MID TO UPPER RIDGES DOMINATES MUCH OF THE REMAINDER OF THE CARIBBEAN. THE FIRST IS EXTENDING E FROM THE EPAC...THROUGH CENTRAL AMERICA OUT TO 75W WITH THE AXIS ALONG 15N. THE OTHER MID TO UPPER HIGH IS LOCATED JUST S OF THE VIRGIN ISLANDS. ASSOCIATED DRY/STABLE AIR IS SUPPRESSING CONVECTION OVER MUCH OF THE CARIBBEAN N OF 13N. A WEAK 1009 MB SURFACE LOW IS ANALYZED IN THE SW CARIBBEAN N OF PANAMA NEAR 11N78W. A COUPLE SMALL CLUSTERS OF SCATTERED MODERATE CONVECTION NOTED TO THE E/NE OF THIS LOW FROM 10N-13N BETWEEN 76W-78W. 10-20 KT TRADES DOMINATE MUCH OF THE CARIBBEAN E OF 80W...AND WILL TAKE OVER MUCH OF THE CARIBBEAN INTO THE WEEKEND AS THE FRONT IN THE NW PORTION DISSIPATES. ATLANTIC OCEAN... AN AMPLIFIED TROUGH/RIDGE/TROUGH/RIDGE PATTERN DOMINATES THE ATLC BASIN. THE FIRST IN THIS PATTERN IS THE PRONOUNCED UPPER LOW/TROUGH OFF THE MID ATLC EAST COAST THAT EXTENDS S THROUGH THE SW NORTH ATLC. THE ASSOCIATED COLD FRONT THAT HAS USHERED VERY DRY/PLEASANT FALL WEATHER TO THE AREA IS NOW ALONG 31N68W TO THE SE BAHAMAS NEAR 23N74W. SCATTERED MODERATE CONVECTION IN THE UNSTABLE ENVIRONMENT AHEAD OF THE FRONT IS FROM 22N-29N BETWEEN 64W-70W. THIS ACTIVITY ALSO SUPPORTED BY UPPER DIFFLUENT AIR BETWEEN THE TROUGHING OFF THE EAST COAST AND THE RIDGING EXTENDING NE FROM THE LEEWARD ISLANDS. THE PREFRONTAL GALE IN THIS AREA HAS BEEN ALLOWED TO EXPIRE WITH THE STRONGER GRADIENT NOW N OF THE AREA. AN UPPER LOW IS NEAR 31N38W THAT HAS AN ASSOCIATED COLD FRONT ALONG 32N33W 23N40W 22N56W. SCATTERED MODERATE CONVECTION IS ALONG THE NE PORTION OF THIS BOUNDARY FROM 27N-30N BETWEEN 30W-34W. MINIMAL DEEP CONVECTION NOTED ELSEWHERE ALONG THE FRONT. N OF THIS OLD FRONT LIES A 1029 MB SFC HIGH SE OF NEWFOUNDLAND NEAR 43N48W. AHEAD OF THE FRONT IS A SFC TROUGH ALONG 32N28W 17N39W. ASSOCIATED MODERATE CONVECTION FROM 26N-32N BETWEEN 26W-30W. THE REMAINDER OF THE E ATLC DOMINATED BY STACKED RIDGING OFF THE COAST OF AFRICA THROUGH SW EUROPE. $$ WILLIS