000 AXNT20 KNHC 131732 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 132 PM EDT Tue Jun 13 2017 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 1715 UTC. ...TROPICAL WAVES... A new tropical wave has entered the Atlantic Ocean. Its axis extends from 12N16W to 05N17W. A large area of moderate and isolated strong convection is related to this wave extending from 05N to 10N between 15W and 22W. The wave shows up very well in the TPW animation, where abundant moisture is observed. A wind surge follows the wave. A tropical wave extends from 13N31W to 05N32W moving westward at 15-20 kt. The wave remains embedded within an area of deep-layer moisture as depicted on the TPW product. The wave also coincides with an inverted trough at 700 mb. Visible satellite imagery indicates some inverted-V pattern in association with this feature. Scattered showers are near the wave axis. Another tropical wave extends from 15N54W to 08N55W. The wave is well depicted in the moisture product. A small swirl of low clouds is along the wave axis near 12N. Scattered moderate convection is mainly on the east side of the wave axis, covering the waters from 10N-13N between 50W-54W. A weak tropical wave is over the central Caribbean with axis from 16N72W to 08N72W moving westward at 15-20 kt. This wave is associated with 700 mb troughing. TPW imagery shows a modest surge of moistened air in association with this wave. Scattered showers are within about 75 nm E of the axis over W Venezuela and N Colombia. Another tropical wave is over the Caribbean Sea and extends from 16N82W to a 1008 mb low pressure near 11N82W to the coast of Panama near 09N82W. The wave shows up well in the moisture product and 700 mb streamlines analysis. Satellite imagery and lightning data indicate scattered showers and thunderstorms near the low pressure area. ...MONSOON TROUGH/ITCZ... The Monsoon Trough extends from the coast of west Africa near 09N13W to 07N20W to 09N26W to 06N40W. The ITCZ continues from 06N40W to 08N50W to 09N53W to 08N60W. Three tropical waves are embedded within the Monsoon trough/ITCZ. Most of the convective activity is associated with the above mentioned tropical waves. ...DISCUSSION... GULF OF MEXICO... High pressure of 1021 mb located over the SE CONUS extends a ridge across much of Gulf region producing a moist and humid SE flow over the western half of the Gulf, and mainly and easterly flow across the eastern half of the Gulf, including the Straits of Florida. Fresh to strong southeast winds are noted in scatterometer data over the Bay of Campeche, likely associated with the thermal trough, that moves across this area during the morning hours. A weak low pressure of 1008 mb has developed near Veracruz, and it is forecast to move NW toward the Tuxpan area in about 24 hours. A strong cluster of moderate to strong convection was previously noted in association with this low. Currently, some shower activity is only observed near the low center. Veracruz has reported around three inches of rain (76 mm) over the past 24 hours ending this morning. Abundant cloudiness, with some convective activity, covers the majority of the Gulf. Mosaic Doppler radar from the SE U.S. shows showers with embedded thunderstorms across the north Gulf states, including also much of the Florida Peninsula. Looking ahead, a broad area of low pressure is expected to form over the western Caribbean Sea or Central America late this week or this weekend. Some gradual development of this system is possible thereafter while it moves slowly northwestward into the Gulf region. Computer model indicates that southeast winds will increase over the southwest Gulf by late Saturday ahead of the aforementioned low pressure area expected to approach the region through northern Central America. CARIBBEAN SEA... Two tropical waves are moving across the Caribbean Sea. Please see the tropical waves section for more details. Scatterometer data show moderate to fresh trades across the east and central Caribbean, particularly south of 18N. Gentle to moderate winds are seen over the NW Caribbean. This wind pattern will persit on Wednesday. Winds will diminish into Thursday as the high pressure north of the area lifts farther to the north. Some convective activity is south of central Cuba due to a diffluent pattern aloft. A patch of moisture is generating some shower activity across the Windward Islands. Moisture associated with the tropical wave, currently located near 55W, will bring more showers to those islands on Wednesday. Shallow moisture embedded in the trade wind flow is noted elsewhere. Looking ahead, a broad low pressure area is forecast to develop across central America and the NW Caribbean by the end of the week. ...HISPANIOLA... An upper-level trough extending southward over Puerto Rico into the Caribbean is inhibiting convection somewhat. Expect scattered showers and isolated thunderstorms in association with the local effects, mainly during the afternoon and early evening hours. ATLANTIC OCEAN... Three tropical waves are moving westward between the coast of Africa and the Lesser Antilles. Please refer to the Tropical Waves section above for details. A weak surface trough remains off NE Florida and stretches from 31N80W to 28N81W. This trough is supporting some shower and thunderstorm activity. This trough is expected to dissipate in about 12-24 hours as the Atlantic ridge builds farther west across the western Atlantic. Another surface trough extends from 28N60W to 21N62W. This trough is likely a reflection of an upper-level trough extending from 31N66W to the Turks and Caicos Islands. Some shower activity is near the northern end of the trough. Farther east, another surface trough extends from a very weak 1020 mb low near 28N38W to 24N39W. A swirl of clouds is associated with the low. Otherwise, broad high pressure covers the Atlantic from the Azores to the Carolinas. Moderate to locally fresh trades are around the southern periphery of the ridge between the Windward Islands and 30W. A surge of African dust is reaching 30W as noted in the Saharan Air Layer Tracking Product from CIMSS. For additional information please visit http://www.hurricanes.gov/marine $$ GR