000 AXNT20 KNHC 080004 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON APR 07 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 3N10W 4N20W 1N28W 1N38W TO S OF THE EQUATOR AT 42W AND CONTINUES TO NE BRAZIL SCATTERED STRONG CONVECTION IS WITHIN 180 NM S OF THE AXIS E OF 20W...AND WITHIN 120 NM N OF THE AXIS E OF 20W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM N OF THE AXIS BETWEEN 38W-41W. ...DISCUSSION... GULF OF MEXICO... A SHORT WAVE TROUGH MOVING INTO THE EASTERN GULF EXTENDS FROM THE FAR NW FLORIDA PANHANDLE SW TO 26N88W AND TO THE NW YUCATAN PENINSULA. THE ASSOCIATED SURFACE TROUGH EXTENDS FROM 29N87W SW TO 25N91W TO THE ERN BAY OF CAMPECHE. SCATTERED SHOWERS AND TSTMS ARE WEAKENING WITHIN 150 NM SE OF THE TROUGH FROM 22N-27N...BUT ARE EXPECTED TO REDEVELOP AGAIN DURING THE OVERNIGHT AS THE TROUGH NEARS THE FLORIDA PENINSULA AND PUSHES PAST FLORIDA LATE TUE AFTERNOON AND EARLY EVENING. A WEAK RIDGE EXTENDS FROM THE SE UNITED STATES SW INTO THE NW GULF...WHILE A WEAK 1012 MB HIGH CENTER IS ANALYZED JUST E OF TAMPICO MEXICO. THIS PATTERN IS RESULTING IN RATHER LIGHT ELY ACROSS THE GULF OUTSIDE THE SHOWER AND TSTM ACTIVITY. RETURN SLY FLOW IS FORECAST TO INCREASE THU AHEAD OF THE NEXT COLD FRONT WHICH WILL MOVE OFF THE TEXAS AND LOUISIANA COASTS FRIDAY...THEN MOVE INTO THE E GULF BY SAT AND TO SE OF THE GULF SUN. NEW HIGH PRES THEN BUILDS SE INTO THE WRN GULF OVER THE WEEKEND WITH INCREASING NLY WINDS. CARIBBEAN SEA... THE SRN PORTION OF THE GULF OF MEXICO EXTENDS SSE INTO THE NW CARIBBEAN REACHING INTO GULF OF HONDURAS. TO THE SE OF THE TROUGH BROAD MID/UPPER LEVEL RIDGING COVERS THE ERN AND CENTRAL CARIBBEAN SEA. THE COMBINATION OF THESE TWO FEATURES IS CREATING A ZONAL FLOW OVER MUCH OF THE SEA TO THE SE OF A LINE FROM HAITI TO NE NICARAGUA. MODERATE TO STRONG SUBSIDENCE AND DRY STABLE AIR IS PRESENT N OF THIS LINE. THE RIDGE IS DRAWING UPPER LEVEL MOISTURE NNE FROM COL0MBIA AND THE SRN PORTION OF CENTRAL AMERICA INTO THE SW CARIBBEAN...AND SPREADING EWD TO NEAR 65W BUT QUICKLY ERODES IN THE SUBSIDENCE AREA. PATCHES OF BROKEN LOW CLOUDS WITH ISOLATED SHOWERS ARE MOVING WWD FROM 12N-17N E OF 71W. SCATTERED SHOWERS ARE ALONG THE COAST OF COSTA RICA AND PANAMA...BUT ARE EXPECTED TO DISSIPATE SHORTLY. HIGH PRES N OF THE AREA WILL MAINTAIN LIGHT TO MODERATE E WINDS ACROSS THE EASTERN AND CENTRAL PART OF THE SEA THROUGH THE NEXT FEW DAYS...EXCEPT FOR THE FAR WRN PORTION WHERE SE WINDS OF 20-25 KT WILL CONTINUE THROUGH TUE NIGHT...THEN DIMINISH TO 15-20 KT AS THE HIGH N OF THE AREA SHIFTS E AND WEAKENS. ATLANTIC OCEAN... WEAKENING SHORT WAVE TROUGH EXTENDS INTO THE AREA FROM 32N72W SSE TO NEAR 25N69W. THE UPPER LEVEL FLOW BECOMES SW BEHIND THIS TROUGH IN RESPONSE TO THE GULF OF MEXICO TROUGH. A MID/UPPER LEVEL RIDGE EXTENDS FROM 23N68W NE THROUGH 27N66W TO OUT OF THE AREA AT 32N64W. AT THE SURFACE...A 1010 MB LOW IS ANALYZED NEAR 29N78W AT 2100 UTC WITH A WEAKENING COLD FRONT TO WEST PALM BEACH FLORIDA. THIS LOW IS FORECAST TO QUICKLY MOVE NE OF THE AREA REACHING A POSITION NEAR 31N72W IN ABOUT 24 HOURS...WHILE THE FRONT CONTINUES TO WEAKEN AS MOVES FURTHER S ACROSS S FLORIDA TONIGHT INTO TUE MORNING. BROKEN LOW CLOUDS WITH ISOLATED SHOWERS AND A FEW WEAK TSTMS ARE NOTED N OF 27N AND W OF 71W WITH CLOUD MOTION BEING CYCLONIC. A 1023 MB HIGH CENTER IS ANALYZED NEAR 27N61W WITH A RIDGE SE TO ABOUT 20N51W. HIGH PRES IS PRESENT N OF 17N BETWEEN 54W AND 74W. BROAD CYCLONIC FLOW...BOTH AT THE SURFACE AND ALOFT...DOMINATES THE REMAINDER OF THE REGION TO THE E OF THE HIGH AND N OF 20N. THE SUPPORTIVE UPPER LEVEL TROUGH EXTENDS FROM 32N37W SW THROUGH 26N47W TO 24N57W TO 22N64W. FRAGMENTS OF BROKEN TO OVERCAST LOW AND MID CLOUDS WITH WIDELY SCATTERED SHOWERS ARE NOTED WITHIN THE AREA OF BROAD CYCLONIC FLOW. BROAD E/W UPPER RIDGE COVERS THE TROPICAL BELT WITH AN UPPER LEVEL ANTICYCLONE NEAR 9N19W. A WEAK 105 MB HIGH NEAR 19N23W IS FORECAST TO DISSIPATE IN 24 HRS. $$ AGUIRRE