000 AXNT20 KNHC 031750 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON JUL 02 2007 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURE... A LOW PRES SYSTEM ASSOCIATED WITH A TROPICAL WAVE IS ANALYZED 1014 MB CENTERED NEAR 10N39W OR ABOUT 1350-1400 NM E OF THE LESSER ANTILLES. THIS SYSTEM HAS A WELL-DEFINED CIRCULATION WITH THE CENTER PARTIALLY EXPOSED TO THE NE OF THE MORE DENSE CLOUD COVER. SCATTERED MODERATE CONVECTION IS WITHIN 180 NM S AND W OF THE CENTER. ...TROPICAL WAVES... A TROPICAL WAVE IS TITLED ALONG 20N47W 4N50W MOVING W NEAR 15 KT. THIS WAVE MAINLY ACTS AS A SURGE IN LOW-LEVEL MOISTURE AND A SLIGHT INCREASE IN WINDS. SHOWER ACTIVITY IS AT BEST ISOLATED WITHIN 120 NM EITHER SIDE OF THE WAVE AXIS. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 11N15W 8N23W 10N34W 9N45W 9N62W. SCATTERED SHOWERS AND TSTMS ARE WITHIN 120 NM N AND 180 NM S OF THE AXIS E OF 28W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LOW HAS PUSHED SWD OVER THE PAST DAY OR SO NOW CENTERED IN THE EXTREME SE GULF NEAR 24N84W. INSTABILITY ASSOCIATED WITH THIS FEATURE IS PRODUCING HIGH LEVEL MOISTURE ACROSS THE E GULF. A FRONTAL BOUNDARY...SUPPORTED BY A LARGE UPPER TROUGH NE OF THE REGION....EXTENDS FROM A 1017 MB LOW OFF THE NE FLORIDA COASTLINE ACROSS THE PANHANDLE AND THEN WELL INLAND INTO THE SE STATES. A VAGUE PRE-FRONTAL TROUGH LIES AHEAD OF THE FRONT WITH THE TAIL END CUTTING ACROSS S FLA. THESE LOW-LEVEL BOUNDARIES ALONG WITH UPPER MOISTURE IN PLACE WILL LIKELY LEAD TO A INCREASE IN SHOWER AND TSTM ACTIVITY LATER THIS AFTERNOON... ESPECIALLY OVER LAND AREAS. CURRENTLY...DOPPLER RADAR IS SHOWING ISOLATED SHOWERS AND TSTMS ACROSS THE REGION E OF 88W. AN UPPER RIDGE STRETCHES NE FROM MEXICO TO LOUISIANA. DIFFLUENCE ALOFT BETWEEN THIS RIDGE AND ANOTHER UPPER LOW OVER TEXAS IS PRODUCING NUMEROUS SHOWERS AND TSTMS ACROSS THE NW GULF AND PORTIONS OF SE TEXAS AND SW LOUISIANA...N OF 27N BETWEEN 94W-97W. AT THE SFC...WEAK 1018 MB HIGH CENTER IS LOCATED NEAR 27N87W. THIS HIGH IS PRODUCING LIGHT AND VARIABLE WINDS ACROSS THE E GULF. HOWEVER...MODERATE SELY WINDS ARE EVIDENT IN THE W PORTION WHERE THE PRES GRADIENT TIGHTENS DUE TO A NEARBY TROPICAL WAVE. CARIBBEAN SEA... A PAIR OF UPPER LOWS ARE SPINNING ABOVE THE CARIB. THE LARGER MORE DEFINED UPPER SYSTEM IS MOVING SWD OVER NW CUBA WITH THE OTHER S OF HAITI NEAR 17N73W. THIS ENERGY IS PRODUCING BROKEN HIGH LEVEL CLOUDINESS ACROSS THE W CARIB AND SCATTERED MOISTURE ACROSS THE CENTRAL. THE ERN PORTION IS UNDER A VERY DRY SUBSIDENT ENVIRONMENT ADVECTED W FROM THE TROPICAL ATLC. THIS SURGE OF DRY AIR IS EXPECTED TO PERSIST AND SPREAD FURTHER W OVER THE NEXT DAY OR SO. THE ONLY AREA OF DEEP MOISTURE IS OVER PANAMA AND THE COASTAL WATERS ASSOCIATED WITH THE ITCZ. AT THE SFC...A 1010 Z QSCAT PASS SHOWED A LARGE AREA OF 20-30 KT ELY TRADES ACROSS THE CARIB W OF 67W. THESE STRONG WINDS ARE CARRYING TYPICAL LOW CLOUD STREAMERS WITH EMBEDDED ISOLATED SHOWERS ACROSS THE REGION. LITTLE CHANGE IS EXPECTED TOMORROW. ATLANTIC OCEAN... A FRONTAL SYSTEM CONTINUES TO PRESS SLOWLY SE ENTERING THE AREA NEAR 32N62W TO A FRONTAL WAVE NEAR 28N66W CONTINUING TO ANOTHER FRONTAL WAVE OFF THE N CENTRAL FLORIDA COASTLINE THEN INLAND ACROSS THE SE STATES. LOW-LEVEL CONVERGENCE NEAR THIS FRONT ALONG WITH MOIST UPPER SWLY FLOW AND DIFFLUENCE...BETWEEN A VERY LARGE POLAR LOW AND AN UPPER HIGH NEAR 27N58W...IS PRODUCING SCATTERED SHOWERS AND TSTMS WITHIN 150 NM EITHER SIDE OF THE FRONT. SHOWER ACTIVITY IS MOST ORGANIZED NEAR THE FRONTAL WAVES WITH DOPPLER RADAR SHOWING SOME SPIN IN THE PRECIP ECHOS OFF THE COAST OF ST AUGUSTINE FLORIDA. ISOLATED SHOWERS AND TSTMS LIE S OF 25N W OF 75W TRIGGERED BY AN ILL-DEFINED PRE-FRONTAL TROUGH. FARTHER E...RIDGING DOMINATES BOTH AT THE SFC AND ALOFT. THE SFC AZORES HIGH IS ANALYZED 1032 MB NEAR 36N29W. THIS HIGH IS PRODUCING A LARGE AREA OF MODERATE TRADES ACROSS THE ATLC. STRONG NLY WINDS ARE NEAR THE AFRICAN COAST DUE TO THE TIGHTENING PRES GRADIENT BETWEEN THE HIGH AND INVERTED TROUGHING OVER THE CONTINENT. THREE UPPER HIGHS ARE PROVIDING A VERY STABLE AIRMASS ACROSS THE CENTRAL AND E ATLC WITH ONLY LOW-LEVEL STABLE STRATOCUMULUS CLOUDS SEEN ACROSS THIS PART OF THE BASIN. $$ CANGIALOSI