000 AXNT20 KNHC 242327 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU MAY 24 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 9N13W 5N22W 4N37W 3N52W. SMALL CLUSTERS OF SCATTERED MODERATE CONVECTION IS WITHIN 120 NM EITHER SIDE OF THE AXIS BETWEEN 33W-44W. SIMILAR ACTIVITY IS WITHIN 60 NM EITHER SIDE E OF 24W AND FROM 1N-4N BETWEEN 6W-9W. SCATTERED MODERATE TO STRONG IS LOCATED E OF THE PRIME MERIDIAN N OF 4N. THE GULF OF MEXICO... LARGE HEALTHY SFC HIGH PRES RIDGE CENTERED OFF THE MID-ATLANTIC COASTLINE IS PRODUCING STRONG ELY WINDS ACROSS THE GULF. LATEST SFC OBS SHOW THE STRONGEST WINDS IN THE E GULF...GENERALLY IN THE 20-25 KT RANGE EXCEPT FOR A COUPLE 30 KT SHIP OBS IN THE FLORIDA STRAITS. THE PRES GRAD RELAXES A BIT IN THE W GULF BUT STILL EASTERLIES ARE 15-20 KT. THIS STIFF FLOW IS ADVECTING LOW TO MID LEVEL CLOUD STREAMERS FROM THE ATLC WATERS ACROSS THE FL PENINSULA AND THEN THINNING AS THEY MOVE WWD IN THE GULF. MOSAIC DOPPLER RADAR DEPICTS SCATTERED SHOWERS ASSOCIATED WITH THESE STREAMERS ON THE E COAST OF FLA...BUT MOST APPEAR TO BE DRYING OUT BEFORE REACHING THE W COAST OF THE STATE. IN THE MID AND UPPER LEVELS...TROUGHING COVERS THE ERN HALF WHILE MODEST RIDGING COVERS THE WRN HALF. A 70-90 KT JET BRANCH PICKS UP MOISTURE IN A DIFFLUENT ZONE BETWEEN THESE FEATURES...S OF 25N E OF 86W...AND EXTENDS FROM 24N88W ACROSS THE BAHAMAS AND MUCH FURTHER NE INTO THE ATLC. ELSEWHERE...STABLE AIR IS AIDING IN THE MOSTLY FAIR WEATHER. LOOKING AHEAD...STRONG ELY WINDS ARE EXPECTED TO REMAIN THAT WAY THRU FRI NIGHT AND THEN SLOWLY RELAX THEREAFTER AS HIGH PRES SINKS SWD AND WEAKENS. THE CARIBBEAN SEA... UNLIKE THE TIGHT PRES GRAD IN THE GULF...BROAD SFC TROUGHING IS THE GENERAL THEME ACROSS THE CARIB. THIS TROUGHING IS ASSOCIATED WITH A LARGE TROUGH OF LOW PRES IN THE EPAC OFF THE COAST OF COSTA RICA/NICARAGUA AND A FRONTAL BOUNDARY N OF THE AREA IN THE ATLC. THESE FEATURES HAVE ALLOWED WINDS TO BE LIGHTER THAN NORMAL ROUGHLY BETWEEN 10-20 KT. THE COMBINATION OF UPPER DIFFLUENCE S OF A JET BRANCH EXTENDING ACROSS CUBA AND THE BAHAMAS AND SOME DEBRIS LOW-LEVEL FRONTAL MOISTURE BLOWN WSW BY THE STRONG SFC FLOW IS PRODUCING SCATTERED SHOWERS AND ISOLATED TSTMS N OF 18N ACROSS THE ENTIRE REGION. SCATTERED MODERATE CONVECTION LIES FURTHER S ALONG THE ITCZ...PARTICULARLY FLARED UP OVER LAND COLOMBIA/PANAMA/COSTA RICA...WHERE INSTABILITY IS GREATER. THERE IS SOME SCATTERED SHOWER ACTIVITY IN THE SW CARIB S OF 13W W OF 73W...BUT NOTHING IMPRESSIVE. LOOKING AHEAD A COUPLE DAYS...MODELS SHOW THE ATLC FRONT LIFTING NWD A BIT WHICH COULD DECREASE THE SHOWERS/TSTMS ACROSS THE NRN CARIB WHILE MOISTURE MAY INCREASE IN THE S/CENTRAL PORTION. THE ATLANTIC OCEAN... A 1032 MB HIGH PRES SYSTEM IS CENTERED OFF THE U.S. MID-ATLANTIC COAST NEAR 37N74W. FARTHER E...A STALLED FRONT ENTERS THE AREA NEAR 32N53W AND EXTENDS SW ALONG 24N62W THEN DISSIPATING TO THE SE BAHAMAS. A TIGHT PRES GRAD HAS SET UP BETWEEN THESE FEATURES PRODUCING 20-30 KT NE TO E WINDS ACROSS THE SW ATLC. LOW-LEVEL LIFT NEAR THE FRONT ALONG WITH GOOD DIFFLUENCE ALOFT JUST E OF AN UPPER JET AXIS IS GENERATING SCATTERED SHOWERS AND TSTMS WITHIN 180 NM EITHER SIDE OF THE FRONT. DRY AIR ALOFT COVERS THE REGION N OF 25N W OF 65W KEEPING THE ATMOSPHERE RATHER STABLE WITH ONLY A LOW-LEVEL STRATOCUMULUS DECK. THE SFC PATTERN IN THE CENTRAL AND EASTERN ATLC IS DOMINATED BY A 1032 MB HIGH CENTERED ABOUT 150-200 NM NW OF THE WRN AZORES. THIS HIGH IS PRODUCING MODERATE TRADES ACROSS THE TROPICAL/SUBTROPICAL ATLC AS THE GRADIENT IS MUCH MORE RELAXED THAN THE W ATLC. IN THE UPPER LEVELS...A MASSIVE UPPER LOW IS LOCATED OFF THE IBERIAN PENINSULA WITH ITS ASSOCIATED TROUGHING COVERING THE AREA N OF 20N. A BROAD FLAT UPPER RIDGE IS CENTERED IN THE DEEP TROPICS NEAR 7N23W WITH RIDGING POKING NWD TOWARD THE TROUGH. A STRONG 110-130 KT UPPER JET HAS SET UP BETWEEN THESE FEATURES EXTENDING FROM 20N36W TO THE AFRICAN COAST NEAR 22N16W. HOWEVER...LITTLE SIGNIFICANT MOISTURE IS ASSOCIATED WITH ANY OF THESE UPPER FEATURES. IN FACT...OUTSIDE OF THE ITCZ...WIDESPREAD FAIR WEATHER IS THE RULE. $$ CANGIALOSI