000 AXNT20 KNHC 281719 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1219 PM EST Sat Dec 28 2019 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 1700 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through 03N/04N along the Prime Meridian, and it continues to 04N18W. The ITCZ continues from 04N18W 04N30W, and to 03N39W. Precipitation: isolated moderate to locally strong is within 90 nm to the north of the monsoon trough/ ITCZ, and within 180 nm to the south of the monsoon trough/ITCZ, and from 04N to 06N between 40W and 45W. GULF OF MEXICO... A cold front still is well inland, moving through the area of the Texas Big Bend. Surface S to SE wind flow spans the Gulf of Mexico. The front is forecast to reach the far NW Gulf of Mexico in about 24 hours or so. An upper level ridge is along 90W. High level moisture is moving from Mexico northeastward, to the west of 90W. Moist southerly wind flow will increase slightly in the northwest Gulf today, between high pressure in the western Atlantic Ocean and a cold front moving across the southern Plains toward the Texas coast. The front will move into the far northwest Gulf of Mexico by Sunday afternoon. The front will reach from the Florida Big Bend to Veracruz Mexico by early Monday. The front will stall from the Straits of Florida to the Bay of Campeche, into Tuesday. It is possible that a low pressure center may form along the front in the western Gulf of Mexico by late Tuesday, but the low pressure center should dissipate through Wednesday. CARIBBEAN SEA... Water vapor satellite imagery, and the GFS model for 250 mb, show a trough that extends from the Windward Passage to the border of Costa Rica and Panama. Comparatively drier air in subsidence is on the W/NW side of the upper level trough. Precipitation: isolated moderate to locally strong is from 13N southward from 80W westward. Precipitation: Scattered strong is in the Gulf of Uraba, near the border of Colombia and Panama. The monsoon trough is along 10N75W in Colombia, beyond 06N78W, into the eastern Pacific Ocean. High pressure to the north of the area will allow for fresh to strong northeast to east winds in most of the central Caribbean Sea through Sunday night. These winds will diminish slightly early next week, as the high pressure shifts southeastward and weakens. Long-period north swell will propagate through the Atlantic Ocean passages, and the tropical Atlantic Ocean off the Leeward and Windward Islands, through early next week. ATLANTIC OCEAN... A cold front passes through 32N30W to 26N34W, 20N40W, 19N50W, and to 19N57W. A shear line continues from 19N55W to 21N66W and 22N73W. Precipitation: Scattered moderate to isolated strong is within 150 nm to the ESE of the cold front from 23N northward. Isolated moderate is within 100 nm to the SE of the cold front from 18N to 23N. Rainshowers are possible elsewhere within 180 nm to the north of the cold front, and within 60 nm to the south of the cold front. Scatterometer wind data from 28/1200 UTC and 28N/1300 UTC were showing 20 knot to 25 knot winds on the northern side of the shear line, and 10 knot to 15 knot winds on the southern side of the shear line. A surface ridge from Bermuda to the Carolinas will shift toward the southeast through early next week. The ridge will be in advance of a cold front, that will move off the northeast Florida coast on Monday night. The front will continue to move southeastward through Tuesday. The front will stretch from Bermuda to the Straits of Florida by early Wednesday. $$ MT