000 AXNT20 KNHC 041752 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU JUN 04 2009 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... A WEAK TROPICAL WAVE IS ALONG 31W S OF 7N MOVING W NEAR 12 KT. THIS WAVE IS ASSOCIATED WITH A LOW AMPLITUDE MAXIMUM IN DEEP LAYER MOISTURE BASED ON THE TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS. SOUTH OF A MIDDLE LEVEL DRY SAHARAN AIR LAYER...THIS WAVE EMERGED OFF THE W AFRICAN COAST BACK ON 01/1200 UTC AND CURRENTLY EXHIBITS A VERY WEAK INVERTED-V CLOUD SIGNATURE WHILE REMAINING EMBEDDED WITHIN THE ITCZ AXIS. ISOLATED MODERATE CONVECTION IS FROM 4N-6N BETWEEN 30W-33W. A TROPICAL WAVE IS ALONG 44W S OF 18N MOVING W NEAR 15 KT. THIS WAVE EXHIBITS HIGH AMPLITUDE AS SEEN IN THE DEEP LAYER MOISTURE FIELD BASED ON THE TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS. SATELLITE IMAGERY INDICATES THAT THE WAVE CORRESPONDS WITH A LARGE INVERTED-V SIGNATURE IN THE LOW LEVEL CLOUD FIELD...WITH SATELLITE DERIVED WINDS INDICATING CYCLONIC CURVATURE IN THE LOW LEVEL FLOW NEAR THE WAVE. SCATTERED MODERATE CONVECTION IS FROM 5N-9N BETWEEN 40W-43W WITH SCATTERED SHOWERS OBSERVED WITHIN 200 NM EITHER SIDE OF THE WAVE AXIS N OF 9N. THE DEEP LAYER MOISTURE ASSOCIATED WITH THE WAVE APPEARS TO BE AT THE LEADING EDGE OF DRY LOW TO MIDDLE LEVEL SAHARAN AIR. A TROPICAL WAVE IS ALONG 83W S OF 17N MOVING W NEAR 12 KT. THE TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS INDICATES THAT THIS WAVE COINCIDES WITH A MAXIMUM IN DEEP LAYER MOISTURE AND IS INTERACTING WITH UPPER LEVEL DIVERGENCE ACROSS PANAMA AND NRN COLOMBIA GENERATING SCATTERED MODERATE CONVECTION S OF 12N W OF 80W. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 9N13W 5N21W 3N30W 2N32W 2N42W AND INTO NE BRAZIL ALONG THE EQUATOR NEAR 50W. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 2N-9N BETWEEN 7W-18W. SCATTERED MODERATE CONVECTION IS FROM 1N-3N BETWEEN 22W-26W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL TROUGH IS PRESENT ACROSS THE GULF REGION WITH AN AXIS EXTENDING FROM 23N87W TO 29N93W TO OVER LOUISIANA. THIS UPPER LEVEL TROUGH IS SUPPORTING A COLD FRONT THAT ENTERS THE GULF NEAR MORGAN CITY LOUISIANA AND EXTENDS ALONG 29N91W 27N95W TO INLAND OVER SRN TEXAS NEAR 27N97W. LOW-LEVEL CONVERGENCE AND ATMOSPHERIC INSTABILITY NEAR AND E OF THE FRONT ALONG WITH UPPER LEVEL DIFFLUENCE IN MOIST SWLY FLOW ALOFT E OF THE UPPER TROUGH AXIS...ARE SUPPORTING SCATTERED SHOWERS AND TSTMS WITHIN 90NM E OF THE FRONT AND ACROSS THE NE GULF N OF 27N IN ASSOCIATION WITH A PRE-FRONTAL TROUGH ANALYZED FROM FORT WALTON BEACH FLORIDA SW TO 28N88W. ALSO S OF 27N E OF 90W...SCATTERED SHOWERS AND TSTMS ARE OBSERVED ON SATELLITE AND MOSAIC DOPPLER RADAR IMAGERY...AS THE BASE OF THE MIDDLE TO UPPER LEVEL TROUGH SWINGS NEWD ACROSS THE E GULF AND FLORIDA PENINSULA THIS AFTERNOON AND EVENING. ACROSS THE SW GULF...DEEP LAYER DRY AIR AND SUBSIDENCE IN NWLY FLOW ALOFT ARE SUPPORTING GENERALLY FAIR WEATHER. CARIBBEAN SEA... DEEP LAYER DRY AIR IN W-NWLY FLOW AND WEAK RIDGING ALOFT IS RESULTING IN GENERALLY FAIR WEATHER ACROSS MUCH OF THE CENTRAL CARIBBEAN. HOWEVER...UPPER LEVEL MOISTURE AND HIGH LEVEL CLOUDS CONTINUE TO STREAM E-NEWD ACROSS THE NW CARIBBEAN. A SURFACE RIDGE N OF THE CARIBBEAN ACROSS THE W ATLC COMBINED WITH BROAD LOW PRESSURE OVER NWRN SOUTH AMERICA WILL CONTINUE TO PRODUCE FRESH TO STRONG TRADE WINDS ACROSS THE CARIBBEAN. THE STRONGEST OF THESE TRADE WINDS ARE FOUND NEAR THE COAST OF COLOMBIA... WHERE NE WINDS OF 25 TO 30 KT ARE OCCURRING. THE TRADE WINDS ARE ADVECTING POCKETS OF LOW LEVEL MOISTURE AND ISOLATED SHOWERS EWD ACROSS THE CARIBBEAN...WITH THE GREATEST CONCENTRATION OF THESE SHOWERS WITHIN 120 NM EITHER SIDE OF A SURFACE TROUGH IN THE NE CARIBBEAN EXTENDING FROM 15N62W TO E OF PUERTO RICO NEAR 18N64W AND INTO THE SW NORTH ATLC. ATLANTIC OCEAN... UPPER LEVEL DIVERGENCE AND DEEP LAYER MOISTURE NEAR AN UPPER LEVEL RIDGE OVER THE SW NORTH ATLC ARE RESULTING IN SCATTERED SHOWERS AND TSTMS FROM 23N-32N W OF 75W INCLUDING THE BAHAMAS... AND ADJACENT COASTAL WATER AREAS ALONG THE ERN US SEABOARD. ADDITIONALLY...LOW LEVEL CONVERGENCE IS RESULTING IN SCATTERED SHOWERS WITHIN 120 NM EITHER SIDE OF A SURFACE TROUGH EXTENDING FROM E OF PUERTO RICO NEAR 18N64W TO 21N67W. ALSO...ISOLATED SHOWERS ARE OCCURRING N OF 24N BETWEEN 59W-67W...WHERE ATMOSPHERIC INSTABILITY IS PRESENT NEAR AN UPPER LEVEL TROUGH. ACROSS MUCH OF THE CENTRAL AND E ATLC...A BROAD SURFACE RIDGE IS RESULTING IN GENERALLY FAIR WEATHER. HOWEVER...A SURFACE TROUGH EXTENDS FROM NE OF THE DISCUSSION AREA TO 32N27W TO 31N28W. LOW LEVEL CONVERGENCE IS SUPPORTING SCATTERED SHOWERS WITHIN 60 NM EITHER SIDE OF THIS SURFACE TROUGH. ACROSS THE TROPICAL ATLC... AN UPPER LEVEL RIDGE IS S OF 18N E OF 45W WITH AN UPPER LEVEL HIGH NEAR 9N33W. UPPER LEVEL DIVERGENCE NEAR THESE UPPER LEVEL FEATURES IS ENHANCING THE CONVECTION ASSOCIATED WITH THE ITCZ AND THE TROPICAL WAVES ALONG 31W AND 44W. $$ HUFFMAN