000 AXNT20 KNHC 011744 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT JUN 01 2013 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1645 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS MOVING THROUGH THE MONSOON TROUGH OFF THE COAST OF AFRICA ALONG 18N20W TO 7N22W MOVING WEST AT 15-20 KT. THE WAVE LIES ON THE WEST SIDE OF A SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. THERE IS ALSO A CLEARING IN THE AREA OF AFRICAN DUST THAT IS NORTH AND WEST OF THE WAVE. FINALLY...THE WAVE COINCIDES WITH AN AREA OF POTENTIAL VORTICITY AT THE 315 KELVIN LEVEL ALONG WITH A 700 MB TROUGH AXIS. SCATTERED MODERATE CONVECTION IS NEAR THE SOUTHERN EXTENT OF THE WAVE AXIS FROM 4N-8N BETWEEN 18W-24W. TROPICAL WAVE IS ALONG 13N46W TO 6N47W MOVING WEST AT 15 KT. THE WAVE IS ON THE LEADING EDGE OF A SURGE OF DEEP LAYER MOISTURE PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. IT ALSO IS AHEAD OF A LARGE AREA OF DUST THAT EXTENDS AROUND THE EASTERN WAVE AND CONTINUES TO ABOUT 45W. MODEL POTENTIAL VORTICITY FIELDS AT THE 315 KELVIN LEVEL ALSO INDICATE A SMALL AREA OF POTENTIAL VORTICITY IN THE AREA OF THE WAVE...WHICH COINCIDES WITH A 700 MB TROUGH AXIS. SCATTERED MODERATE CONVECTION IS FROM 5N-9N BETWEEN 43W-49W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF MAURITANIA NEAR 18N16W AND CONTINUES THROUGH A TROPICAL WAVE ALONG 13N22W 7N27W 6N31W. THE ITCZ BEGINS NEAR 6N31W AND CONTINUES ALONG 7N45W 6N60W. BESIDES ACTIVITY NEAR THE TROPICAL WAVES...SCATTERED MODERATE CONVECTION IS FROM 5N-7N BETWEEN 27W-32W. SIMILAR ACTIVITY IS FROM 6N-9N BETWEEN 37W-44W...AND FROM 4N-10N BETWEEN 50W-60W. ...DISCUSSION... GULF OF MEXICO... BROAD SURFACE RIDGING CONTINUES TO DOMINATE THE SURFACE IN THE GULF OF MEXICO. HOWEVER...DEEP LAYER MOISTURE SPREADS THROUGHOUT THE SOUTHERN GULF SUPPORTING SEVERAL AREAS OF SHOWERS/THUNDERSTORMS. ISOLATED SHOWERS ARE IN THE SW GULF FROM 18N-22N BETWEEN 90W-96W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE IN THE SE GULF FROM 23N-25N BETWEEN 85W-90W WITH SIMILAR ACTIVITY MOVING THROUGH THE YUCATAN CHANNEL. ISOLATED SHOWERS/THUNDERSTORMS ARE ALSO MOVING THROUGH THE FLORIDA KEYS AND SOUTH FLORIDA. THE NORTHERN GULF IS UNDER MUCH CLEARER SKIES INFLUENCED BY DRIER AIR ALOFT NORTH OF 26N. THE SOUTHERN GULF IS UNDER THE INFLUENCE OF BROAD UPPER RIDGING WHICH IS DRAWING MOISTURE ACROSS THIS AREA. EAST TO SOUTHEAST WINDS OF 10-15 KT ARE THROUGHOUT THE BASIN. BROAD LOW PRESSURE IS EXPECTED TO FORM IN THE SW GULF OVER THE NEXT COUPLE OF DAYS. ABUNDANT MOISTURE IS EXPECTED TO STAY OVER THE SOUTHERN GULF. CARIBBEAN SEA... ABUNDANT DEEP LAYER MOISTURE IS THROUGHOUT THE WESTERN CARIBBEAN EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. A LARGE BURST OF HEAVY SHOWERS AND ISOLATED THUNDERSTORMS IS FROM 19N-23N BETWEEN 79W-86W COVERING THE YUCATAN CHANNEL AND WESTERN CUBA. SCATTERED SHOWERS/POSSIBLE THUNDERSTORMS ARE ALSO IN THE SW CARIBBEAN FROM 11N-13N BETWEEN 74W-80W. THIS ACTIVITY IS LOCATED NEAR THE MONSOON TROUGH AXIS THAT EXTENDS THROUGH THE NORTHERN CENTRAL AMERICAN COUNTRIES TO NEAR 10N WHERE IT CONTINUES ALONG 10N TOWARDS NORTHERN COLOMBIA. THE REMAINDER OF THE CENTRAL AND EASTERN CARIBBEAN ARE UNDER MOSTLY FAIR CONDITIONS DUE TO DRIER AIR ALOFT AROUND AN UPPER LEVEL TROUGH ALONG 63W. BROAD UPPER RIDGING COVERS THE WESTERN CARIBBEAN CENTERED NEAR 17N81W. TRADEWIND FLOW OF 15-20 KT IS PRESENT THROUGHOUT MUCH OF THE BASIN TURNING SOUTHEASTERLY ACROSS THE WESTERN PORTION WHERE THE ABUNDANT MOISTURE IS BEING DRAWN INTO THE SOUTHERN GULF. LITTLE CHANGE IS EXPECTED OVER THE NEXT 24 HOURS WITH SIGNIFICANT MOISTURE EXPECTED TO REMAIN OVER THE WESTERN CARIBBEAN. BY 48 HOURS...A TROPICAL WAVE IN THE TROPICAL ATLC WILL HAVE REACHED THE LESSER ANTILLES BRINGING A MOIST AIRMASS WITH IT. HISPANIOLA... MOIST AIR REMAINS OVER AND NEAR HISPANIOLA TO BOTH THE WEST AND NORTH OF THE ISLAND WITH DRIER AIR TO THE EAST. AN UPPER TROUGH IS ALSO EAST OF THE AREA DRAWING MOIST AIR ALOFT FROM THE DEEP LAYER MOISTURE OVER THE WESTERN CARIBBEAN AND WEST ATLC. CURRENTLY...ONLY A FEW ISOLATED SHOWERS AND THUNDERSTORMS ARE OVER THE ISLAND MAINLY IN THE INTERIOR. SHOWER/THUNDERSTORM ACTIVITY WILL LIKELY BUILD AS THE DAY GOES ON. A SIMILAR PATTERN WILL BE PRESENT FOR THE NEXT COUPLE OF DAYS. ATLANTIC OCEAN... SURFACE RIDGING IS THE DOMINATE SURFACE FEATURE ACROSS THE WEST ATLC EXTENDING FROM A 1025 MB HIGH NEAR 32N60W. HOWEVER...DEEP LAYER MOISTURE COVERS THE AREA NEAR THE BAHAMAS. HEAVY SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 23N-28N BETWEEN 68W-75W. ISOLATED SHOWERS/THUNDERSTORMS ARE ALSO FROM 21N-27N BETWEEN 75W- 80W...AND FROM 25N-29N BETWEEN 64W-69W. ABUNDANT MOISTURE IS EXPECTED TO REMAIN OVER THIS AREA FOR THE NEXT COUPLE OF DAYS. ALOFT...AN UPPER LEVEL LOW IS NORTH OF THE AREA WITH AXIS EXTENDING INTO THE WEST ATLC AND CONTINUES INTO THE EASTERN CARIBBEAN NEAR 65W. AN UPPER LEVEL RIDGE IS SANDWICHED BETWEEN THIS UPPER TROUGH AND A SECOND UPPER TROUGH TO THE EAST ALONG 33N38W 17N48W. BROAD UPPER RIDGING COVERS THE REMAINDER OF THE BASIN CENTERED NEAR 17N17W. THE UPPER RIDGE SUPPORTS A SURFACE RIDGE ANCHORED BY A 1035 MB HIGH NEAR 44N20W. VISIBLE SATELLITE IMAGERY INDICATES AN AREA OF AFRICAN DUST EXTENDS AROUND THE TROPICAL WAVE IN THE EAST ATLC AND CONTINUES TO NEAR 45W. 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