000 AXNT20 KNHC 271747 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN JUL 27 2008 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND 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. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 32W/33W S OF 20N MOVING W 15-20 KT. THIS LARGE WAVE ENCOMPASSES A BROAD AREA OF LOW-LEVEL CYCLONIC TURNING THAT COVERS WELL OVER A 10 DEGREE AREA OF LONGITUDE WITH A MID-LEVEL FOCUSED VORTICITY MAXIMUM ALONG THE AXIS NEAR 14N. EVEN WITH THE MODEST AMPLIFICATION...DEEP CONVECTION IS ABSENT. TROPICAL WAVE IS ALONG 50W S OF 25N MOVING W 10-15 KT. AN EARLIER QUIKSCAT PASS CONFIRMS POSITION OF THE WAVE AND THAT DESPITE HIGH AMPLITUDE WAVE EXHIBITS NO ORGANIZED AREAS OF CONVECTION AS IT MOVES UNDER AN AREA OF STRONG SUBSIDENCE ALOFT. NORTHERN BRANCH OF WAVE HAS BROKEN OFF AND IS ANALYZED AS A SURFACE TROUGH WHICH IS BEING STEERED NORTHWARD DUE TO WRN ATLC UPPER LEVEL TROUGHING. TROPICAL WAVE IS ALONG 79W/80W S OF 20N MOVING W NEAR 15-20 KT. LITTLE SIGNATURE IS OBSERVED ON SATELLITE IMAGERY AND AN EARLIER QUIKSCAT PASS SUGGESTS SLIGHT WEAK CYCLONIC TURNING WEST OF JAMAICA. THE MIMIC TPW PRODUCT FROM CIMSS SHOWS A WEAK AND QUICK MOVING MOISTURE SURGE ASSOCIATED WITH THIS FEATURE. SCATTERED MODERATE CONVECTION IS ACROSS PANAMA...COSTA RICA AND THE SW CARIBBEAN SEA S OF 11N BUT IS MOST LIKELY DUE TO AN UPPER DIFFLUENT PATTERN AND CLOSE PROXIMITY TO THE ITCZ. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 12N13W 15N25W 13N31W 10N35W 5N44W 6N49W 11N 54W AND INTO ERN VENEZUELA NEAR 9N61W. CLUSTER OF WIDELY SCATTERED MODERATE CONVECTION IS ALONG THE W AFRICAN COAST AND EXTENDS FROM 4N-11N BETWEEN 10W-19W. SCATTERED MODERATE CONVECTION IS FROM 6N-11N BETWEEN 38W-40W. SIMILAR CONVECTION IS FROM 9N-12N BETWEEN 56W-62W. ...DISCUSSION... GULF OF MEXICO... STRONG NE TO E MID TO UPPER LEVEL FLOW RESIDES ON THE SRN PERIPHERY OF AN UPPER RIDGE CENTERED OVER W TEXAS AND SRN NEW MEXICO. THIS UPPER FLOW LIES N OF 21N AND IS ADVECTING A FAIR AMOUNT OF HIGH CLOUDINESS ACROSS THE NE AND NORTH CENTRAL GULF. AT THE SURFACE A WEAK TROUGH EXTENDS FROM NORTH OF TALLAHASSEE FLORIDA SW INTO THE NE GULF NEAR 28N87W. THIS FORCING MECHANISM COUPLED WITH A DIFFLUENT PATTERN ALOFT IS GENERATING SCATTERED SHOWERS AND TSTMS ACROSS THE GULF N OF 27N BETWEEN THE BIG BEND OF FLORIDA TO 92W. ALSO SCATTERED SHOWERS AND ISOLATED TSTMS ARE OVER THE FLORIDA KEYS EXTENDING SW INTO WRN PORTIONS OF THE FLORIDA STRAITS. ELSEWHERE...A PAIR OF SURFACE HIGHS COVER THE REMAINDER OF THE GULF W OF 92W WITH A 1016 MB HIGH CENTERED NEAR 27N91W AND A 1019 MB HIGH CENTERED NEAR VERACRUZ MEXICO. THESE TWO ANTICYCLONIC CIRCULATIONS ARE ALLOWING WINDS TO BE LIGHT VARIABLE ACROSS MUCH OF THE AREA. CARIBBEAN SEA... UPPER LEVEL TROUGHING EXTENDS FROM THE W ATLC ACROSS CUBA... JAMAICA AND HISPANIOLA WHILE AN UPPER LEVEL HIGH IS LOCATED OVER NRN NICARAGUA AND HONDURAS. THESE TWO FEATURES ARE PRODUCING N-NW FLOW OVER THE WRN CARIBBEAN W OF 76W. AMPLE MIDDLE TO UPPER LEVEL MOISTURE IS ACROSS THE GREATER ANTILLES N OF 17N AND IS GENERATING SCATTERED SHOWERS/ISOLATED TSTMS ACROSS CUBA HISPANIOLA AND THE WINDWARD PASSAGE. A SMALL UPPER LOW IS LOCATED NEAR THE SRN WINDWARD ISLANDS DRAWING MID-HIGH LEVEL CLOUDINESS ACROSS THE ANTILLES S OF 13N AND SCATTERED MODERATE CONVECTION ACROSS TRINIDAD AND TOBAGO. ELSEWHERE...WATER VAPOR IMAGERY SHOWS WIDESPREAD STRONG TO MODERATE DRY AIR WHICH IS SUPPRESSING THE DEVELOPMENT OF ANY DEEP CONVECTIVE ACTIVITY... WITH EXCEPTION TO THE ITCZ CONVECTION WHICH SKIRTS THE SW WATERS S OF 11N. TRADE WINDS REMAIN STRONG OVER THE S CENTRAL WATERS BUT OTHERWISE REMAIN LIGHT TO MODERATE ACROSS THE REMAINDER OF THE REGION. ATLANTIC OCEAN... A LARGE UPPER LOW CENTERED NEAR 27N66W WITH ASSOCIATED TROUGHING EXTENDS SW ACROSS CUBA AND THE WINDWARD PASSAGE PRODUCING DISORGANIZED WIDELY SCATTERED SHOWERS AND TSTMS W OF 63W. MID-UPPER RIDGING CONTROLS THE REMAINDER OF THE ATLC DISCUSSION AREA WITH AN UPPER HIGH CENTERED NEAR 21N29W. S TO SE UPPER FLOW ON THE WRN PERIPHERY OF THIS RIDGE IS PRODUCING UNFAVORABLE CONDITIONS N OF THE TROPICAL WAVE ALONG 50W. A SURFACE TROUGH IS ANALYZED FROM 31N43W TO 26N48W GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED EMBEDDED TSTMS FROM 26N-31N BETWEEN 43W-49W. BESIDES FOR THAT AREA OF CONVECTION ASSOCIATED WITH THE TROUGH...MUCH OF THE CENTRAL AND ERN ATLC IS VOID OF DEEP CLOUDINESS. AT THE SURFACE STRONGER AREAS OF WIND ARE OBSERVED NEAR THE TROPICAL WAVES...DUE TO THE TIGHTENED PRESSURE PATTERN BETWEEN THOSE LOW PRESSURE FEATURES AND A QUASI-STATIONARY 1027 MB BERMUDA-AZORES HIGH CENTERED NEAR 38N43W. $$ HUFFMAN