000 AXNT20 KNHC 241755 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sun Jan 24 2021 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 1745 UTC. ...SPECIAL FEATURES... Caribbean Gale Warning: The combination of high pressure located north of the Caribbean Sea and low pressure over Colombia and Panama will continue to lead to northeast to east winds to pulse to gale force within about 90 nm of the coast of Colombia during the overnight and early morning hours through at least Wed. Wave heights generated by these winds are forecast to be in the range of 8-12 ft, mainly around daybreak each day. Please read the latest NWS High Seas Forecast issued by the National Hurricane Center at the website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from the coast of Liberia near 05N09W to 05N15W, where latest scatterometer data indicates that it transitions to the ITCZ to 04N25W to 03N36W and to near 01N46W. Scattered moderate to isolated strong convection is seen within 120 nm north of the ITCZ between 34W-39W. Scattered moderate convection is within 180 nm south of the monsoon trough between 07W-13Wm, within 120 nm north of the ITCZ between 29W-34W and within 60 nm north of the ITCZ between 21W-27W. GULF OF MEXICO... As of 15Z, a stationary front extends from near Fort Myers, Florida northwestward to 27N84W, where it becomes a warm front continuing northwestward to inland far southwestern Mississippi. Satellite imagery shows patches of low stratus type clouds and sea fog over the NE Gulf and over the southeastern Gulf from 25N- 28N between 82W-87W. Smaller patches of similar type clouds and fog are advecting northward over the most of the western Gulf. Small isolated showers moving northward are over some sections of the central and western Gulf. Sky conditions are mostly clear over the far southeastern Gulf south of 25N and over sections of the south-central Gulf. As for the forecast: the stationary front will gradually weaken through this evening as the warm front continues to lift northward. The area of fog over the NE Gulf will remain through tonight, while the fog over the southeastern Gulf slowly erodes. Building high pressure over the southeastern U.S. will bring increasing southerly return flow and building seas over the western Gulf during today and through Mon. The ridge will weaken late Mon as a weak cold front moves into the western Gulf and becomes stationary by early Tue. The front will then get reinforced on Wed and progress eastward across the basin into Thu night. In the wake of this front, gale force north winds are expected Wed afternoon through Thu over sections of the western Gulf. CARIBBEAN SEA... Pulsing winds to gale force are expected during the overnight and early morning hours near the coast of Colombia through the next few days. Please, refer to the Special Features section above for details. Elsewhere, latest ASCAT and buoy data indicate that mainly moderate to fresh trades are present, with the exceptions of fresh to strong trades over the southern part of the central Caribbean near the gale wind area and gentle to moderate trades over the eastern and northwestern Caribbean. Moderate to fresh northeast winds are over the Windward Passage. Very stable atmospheric conditions present throughout, both aloft and at the low-levels, is allowing for only small patches of rather shallow moisture in the form of scattered to broken low clouds to exist across the basin. These clouds are quickly moving westward and some may be attendant by brief passing isolated showers. Small patches of low-level clouds with isolated showers that are also moving quickly westward are near Puerto Rico and the Lesser Antilles. As for the forecast: High pressure north of the Caribbean Sea will continue to allow for the fresh to strong trades over the south- central Caribbean through at least Wed night. Winds elsewhere will change little in speeds through Tue night, except winds will pulse to fresh to strong speeds over the Gulf of Honduras during that time. North swell will propagate through the Tropical North Atlantic waters late Mon night through Thu night. A cold front will approach the Atlantic waters of Puerto Rico and Hispaniola Mon night. Another cold front will reach the Yucatan Channel late Thu followed by fresh to strong northerly winds into the weekend. ATLANTIC OCEAN... A central Atlantic cold front is analyzed from near 32N46W to 25N59W and to 24N69W, where it transitions to a stationary front to the NW Bahamas and to South Florida. Broken to overcast low and mid-level clouds, with patches of rain and possible scattered showers are along and within 90-120 nm north of the front. A pre- frontal trough extends from 33N44W to 25N54W. Scattered moderate to isolated strong convection is within 180 nm east of the trough north of 28N, while scattered moderate convection is within about 120 nm east of the trough from 25N-28N. This activity is being enhanced by upper divergence occurring east of a broad upper trough that reaches from well north of the area southward to near 21N and between 47W-65W. Latest ASCAT data shows fresh to strong southwest winds east of the pre-frontal to near 42W. Another cold front is along a position from near 32N54W to 29N61W, where it begins to weaken to 28N70W. Scattered to broken low clouds, with possible isolated showers are along and within 60 nm north of the front east of 61W, while scattered low clouds mark the front west of 61W. Satellite imagery, quite impressively, shows cold-air stratocumulus covering the waters north of the second front between 54W-73W. Latest ASCAT data passes depict strong northwest to north winds within the area of stratocumulus clouds. A weak trough extends from 21N52W to 15N54W. Isolated showers are possible near the trough. Remnants of old frontal boundaries are presently identified as weak convergence lines: one extends from 25N50W to the northern Leeward Islands, and the other one extends from near 24N56W to 21N61W to 20N64W and to the northern part of the Mona Passage and to inland the east coast of the Dominican Republic. Mostly scattered low clouds, with possible isolated showers are along and near these convergence lines. The remainder of the Atlantic forecast area is under the influence of a ridge anchored by a high pressure of 1024 mb located just south of the Madeira Islands near 31N16W. Moderate to fresh winds are along the southern periphery of the ridge. As for the forecast: The stationary front will gradually weaken through this evening, while the cold front that extends from near 32N46W to 25N59W and to 24N69W is overtaken by a reinforcing surge of high pressure. This will tend to push the front south to along 21N by Sun night and into the Greater Antilles Mon night. Southerly flow will increase across the waters east of north-central Florida Mon into Tue. Low pressure near Bermuda will bring strong west winds to the northeast waters Tue night into Wed. A stronger cold front will move off the southeastern U.S coast Wed night, while the associated low pressure rapidly intensifies north of the area through the end of the week. Gale force winds and very large seas are expected with this system, mainly to the north of 27N. This could lead to hazardous marine conditions over those waters. $$ Aguirre