000 AXNT20 KNHC 071045 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT MON MAY 07 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1030 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 9N11W 4N20W 2N30W EQ40W 1S50W. ISOLATED MODERATE CONVECTION IS WITHIN 150NM N OF THE AXIS BETWEEN 24W-36W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS S OF THE AXIS FROM 3S-1N BETWEEN 17W-32W. NUMEROUS MODERATE/ISOLATED STRONG IS WITHIN 90NM EITHER SIDE OF THE AXIS W OF 37W. ...DISCUSSION... GULF OF MEXICO... A BACKDOOR COLD FRONT ASSOCIATED WITH THE STRONG LOW OFF THE NORTH CAROLINA COAST CONTINUES TO PUSH THROUGH THE NE GULF. SCATTERED SHOWERS AND TSTMS ARE JUST AHEAD OF THE FRONT WITH THE MOST PRONOUNCED ACTIVITY WITHIN 200NM OF THE MISSISSIPPI COAST. NE TO E WINDS 20-25 KT ARE BEHIND THE FRONT WHILE 10-20 KT E TO SE WINDS ARE OVER THE REST OF THE GULF. BROKEN LOW CLOUDS ARE AFFECTING THE NW GULF/TEXAS COAST AGAIN THIS MORNING WITH A FAIRLY SIGNIFICANT LOW LEVEL INVERSION IN PLACE. UPPER RIDGING IS OVER THE WRN GULF WHICH IS TRANSPORTING UPPER MOISTURE EWD...DOWNSTREAM FROM CONVECTION OVER TEXAS AND THE EPAC. TROUGHING ASSOCIATED WITH DEEP LAYER LOW OFF HATTERAS EXTENDS INTO THE THE NE GULF. MODERATE NE WINDS EXPECTED IN THE E AND CENTRAL GULF THROUGH TONIGHT...VEERING MORE SE IN THE WRN PORTION. CARIBBEAN SEA... THE SFC PRES PATTERN IN THE CARIBBEAN REMAINS WEAK DUE TO LOW PRES IN THE SW N ATLC. SHIPS AND BUOYS ARE MOSTLY REPORTING E TO NELY TRADES IN THE 10-15 KT RANGE...EXCEPT LIGHTER AND MORE VARIABLE N OF 16N WHERE THE WEAKEST GRADIENT EXISTS. LIGHTER THAN NORMAL TRADES WILL CONTINUE THROUGH MIDWEEK WITH A WEAKER THAN USUAL GRADIENT S OF THE STORM SYSTEM OFF THE SOUTHEAST U.S. ISOLATED CLUSTERS OF MODERATE TO STRONG ITCZ CONVECTION ARE AFFECTING CENTRAL AMERICA AND THE SW CARIB S OF 10N. UPPER SW FLOW BETWEEN TROUGHING OVER THE WRN CARIB AND RIDGING OVER THE ERN CARIB IS SPREADING UPPER MOISTURE NE THROUGH THE CENTRAL AND ERN PORTIONS. WESTERN ATLANTIC... ATTENTION REMAINS FOCUSED ON THE STRONG LOW PRES SYSTEM OFF THE CAROLINA COASTLINE....ANALYZED 998 MB NEAR 33N72W. A BACK DOOR COLD FRONT IS PROGRESSING SWD FROM THE LOW TO SOUTH FLORIDA. SCATTERED SHOWERS WITH ISOLATED TSTMS WITH THE FRONT ARE MOSTLY WITHIN 60NM EITHER SIDE OF THE FRONT...THOUGH MIAMI RADAR AND LIGHTNING DATA DEPICT TSTMS ARE MORE SCATTERED BETWEEN SFL AND THE SE BAHAMAS. THE MAIN IMPACT WITH THIS SYSTEM IS THE STRONG WINDS AND LARGE SEAS AS A VERY TIGHT PRES GRADIENT HAS SET UP BETWEEN THE LOW AND STRONG HIGH PRES OVER THE NORTHEAST STATES. A STORM WARNING HAS BEEN POSTED FOR THE FAR NW PORTION OF THE AREA AS DESCRIBED IN THE HIGH SEAS FORECAST. IN ADDITION TO THE ALREADY VERY IMPRESSIVE FETCH...AS THE STORM MOVES SSW IT WILL PROMOTE A CAPTURE FETCH TOWARDS THE BAHAMAS AND FLORIDA. THIS WILL FURTHER ADD TO THE VERY LARGE N/NE SWELL EVENT. HIGH SURF ADVISORIES HAVE THUS BEEN POSTED FOR MUCH OF THE SOUTHEAST COAST...SEE STATEMENTS FROM LOCAL FORECAST OFFICES FOR MORE DETAILS. FARTHER E...A 1008 MB LOW LOCATED NEAR 29N62W ATTACHED IS EXPECTED TO DISSIPATE OVER THE NEXT 24 HOURS. SCATTERED TSTMS ARE MAINLY E OF THE LOW N OF 26N BETWEEN 53W-61W. CENTRAL AND EASTERN ATLANTIC... STRONG AZORES HIGH IS IN CONTROL OF THE PATTERN ACROSS THE ATLC E OF 55W. THIS HIGH IS PRODUCING A LARGE AREA OF MODERATE TO FRESH TRADES...STRONGEST E OF 25W WHERE THE PRES GRADIENT IS TIGHTENED DUE TO LOWER PRES OVER AFRICA. SCATTERED STRATOCUMULUS COVER MUCH OF THE REGION...EXCEPT S OF 18N E OF 28W WHERE THIS LOW-LEVEL CLOUD DECK IS ERODED BY SAHARAN DUST. AN UPPER LOW IS W OF THE CANARY ISLANDS NEAR 30N24W BUT DOES NOT APPEAR TO BE GENERATING MUCH IN THE WAY OF SENSIBLE WEATHER. $$ WILLIS