000 AXNT20 KNHC 221035 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE MAY 22 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 6N10W 2N24W 4N37W 5N44W 5N53W. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 1N-8N BETWEEN 10W-18W. SIMILAR ACTIVITY IS LOCATED S OF 7N E OF 3E. CLUSTERS OF SCATTERED MODERATE ARE WITHIN 240 NM N OF THE AXIS BETWEEN 25W-30W AND W OF 48W. ...DISCUSSION... GULF OF MEXICO... WIDESPREAD FAIR WEATHER IS THE THEME ACROSS THE GULF THIS EARLY MORNING THANKS TO SFC HIGH PRES LOCATED TO THE E OF THE AREA IN THE SW ATLC AND UPPER RIDGING CENTERED OVERHEAD ALONG 90W. SFC WINDS ARE MAINLY OUT OF THE E TO SE ACROSS THE REGION... STRONGEST BETWEEN 24N-28N AS DEPICTED BY SFC OBS AND A 00Z QSCAT PASS WHICH SHOWED WINDS IN THE 15-20 KT RANGE. THIS BRISK BREEZE IS PICKING UP SOME MOISTURE FROM AN AREA OF UNSETTLED WEATHER IN THE BAHAMAS AND CARRYING IT ACROSS THE FL KEYS AND STRAITS INTO THE EXTREME SE GULF WHERE DOPPLER RADAR IS DETECTING LINES OF SHOWER ACTIVITY. MODERATE DRY AIR ALOFT IS KEEPING THE REMAINDER OF THE GULF STABLE SUPPRESSING ANY DEEP CLOUD FORMATION. GLOBAL MODELS FORECAST A REINFORCEMENT OF THE W ATLC RIDGE OVER THE NEXT DAY OR TWO WHICH WILL INCREASE THE ELY WINDS...ESPECIALLY ACROSS THE E GULF. CARIBBEAN SEA... SHIP...BUOY...AND LAND OBSERVATIONS INDICATE THAT THE TROUGH OF LOW PRES IN THE WRN CARIB CONTINUES TO DRIFT SLOWLY TO THE W. AS OF 09Z...THE TROUGH AXIS WAS ANALYZED FROM CENTRAL CUBA TO PANAMA ALONG 22N80W 15N83W 9N81W WITH A HINT OF A WEAK SFC LOW AT THE BASE OF THE TROUGH. MODERATE ELY TRADES LIE E OF THE TROUGH AXIS WITH LIGHT NELY FLOW TO THE W. SCATTERED SHOWERS ARE WITHIN 180 NM E OF THE BOUNDARY. MORE IMPRESSIVE ACTIVITY... SCATTERED MODERATE CONVECTION...IS ALONG THE BASE OF THE TROUGH AND ITCZ GENERALLY S OF 12N W OF 77W. MANY OF THE NWP MODELS SHOW THIS TROUGH AND A DVLPG AREA OF LOW PRES CONTINUING ITS SLOW WWD PROGRESSION MOVING INLAND OVER SRN COUNTRIES OF CENTRAL AMERICA OVER THE NEXT DAY OR TWO AND EVENTUALLY INTO THE EPAC LATER THIS WEEK. ALOFT...THE UPPER FLOW IS GENERALLY ZONAL W OF 75W TURNING MORE TO THE NW E OF THERE AROUND A BROAD FLAT RIDGE CENTERED OVER GUATEMALA. UPPER DIFFLUENCE BETWEEN THIS FLOW AND TROUGHING N OF THE AREA IS PRODUCING AN AREA OF CLOUDINESS N OF 19N BETWEEN HISPANIOLA AND CENTRAL CUBA...HOWEVER MUCH OF THE ASSOCIATED PRECIP IS N OF THE REGION. ATLANTIC OCEAN... BROAD UPPER TROUGHING COVERS MUCH OF THE W ATLC WITH THE LARGE UPPER CYCLONE NOW WELL N IN THE N ATLC. THIS UPPER TROUGH CONTINUES TO SUPPORT A SFC BOUNDARY WHICH ENTERS THE AREA NEAR 32N58W AND EXTENDS SW ALONG 25N66W TO HAITI. LOW-LEVEL LIFT NEAR THE SFC TROUGH ALONG WITH UPPER DIFFLUENCE BETWEEN THE TROUGH AND RIDGE TO THE E IS PRODUCING SCATTERED SHOWERS WITHIN 300 NM E OF THE FRONTAL TROUGH AXIS N OF 25N. AN INTENSIFYING AREA OF ACTIVITY IS IN THE BAHAMAS FROM 22N-25N BETWEEN 71W-76W WHERE LOW-LEVEL CONVERGENCE APPEARS MORE PRONOUNCED. THE SFC FLOW IS BRISK W OF THE TROUGH AXIS WHERE A TIGHTENED PRES GRADIENT EXISTS BETWEEN THE TROUGH AND HIGH PRES TO THE W. THIS FLOW IS EXPECTED TO STRENGTHEN TO 25 KT WITHIN THE NEXT 24 HOURS AS THE PRES GRAD TIGHTENS FURTHER IN RESPONSE TO REINFORCING HIGH PRES N OF THE AREA AND A DVLPG AREA OF LOW PRES ALONG THE SFC TROUGH. VERY HEALTHY NEARLY STATIONARY 1038 MB HIGH PRES CENTERED NEAR 38N36W DOMINATES THE PATTERN ACROSS THE CENTRAL AND E ATLC. THIS HIGH IS PRODUCING A LARGE AREA OF MODERATE TRADES AND A SCATTERED STRATOCUMULUS DECK ACROSS THE REGION. ALOFT...AN UPPER LOW HAS BEEN MEANDERING IN THE CENTRAL ATLC NEAR 27N44W WITH ITS ASSOCIATED TROUGHING STRETCHING SWD TO 9N47W. THIS UPPER LOW HAS BEEN VOID OF ANY SIGNIFICANT CLOUD COVER OVER THE PAST FEW DAYS BUT NOW APPEARS TO GAINING SOME MOISTURE POSSIBLY GENERATING ISOLATED SHOWERS WITHIN 120 NM E OF THE CENTER. THE E ATLC IS AN AREA OF UPPER CONVERGENCE BETWEEN A TROUGH WHICH DIGS SWD ACROSS THE CANARY ISLANDS TO 25N AND UPPER RIDING POKING NWD FROM ITCZ TOWARD THE TROUGH. A STRONG SW-WLY JET LIES BETWEEN THESE UPPER FEATURES EXTENDING FROM 15N40W TO W AFRICA NEAR 24N16W. CORE WINDS ALONG THIS UPPER JET AXIS ARE BETWEEN 100-120 KT BASED ON SATELLITE DERIVED WINDS. PATCHES OF MID-HIGH LEVEL CLOUDS AND ISOLATED SHOWERS ARE DRAWN NEWD FROM THE ITCZ TO THE JET AXIS...WHILE ABUNDANT SINKING AIR ALOFT IS STABILIZING THE ATMOSPHERE N OF THE JET. $$ CANGIALOSI