Atlantic Discussion

  • NHC Atlantic Tropical Weather Discussion
    by (nhcwebmaster) on December 6, 2019 at 11:50 PM

    000 AXNT20 KNHC 062350 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 650 PM EST Fri Dec 6 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 1800 UTC surface analysis and satellite imagery through 2330 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal areas of Sierra Leone near 07N11W to 04N17W to 04N24W. The ITCZ continues from 04N24W to 02N34W to 03N44W. Scattered moderate convection is from 00N-05N between 16W-30W, and from 00N-07N between 05W-16W. GULF OF MEXICO... As of 06/2100 UTC, a weak cold front extends from the mid- Louisiana coast near 30N91W to Brownsville Texas to 26N101W. Winds are gentle ahead of the front and moderate behind the front. Isolated showers and tstorms are seen over the central Gulf, well ahead of the front, from 25N-29N between 86W-92W. Additional isolated showers and tstorms are north of 29N between 85W-88W. Scattered moderate showers are over the western Florida Panhandle between Pensacola and Tallahassee. The remainder of the Gulf of Mexico has light to gentle winds with little to no significant showers. Weak low pressure associated with the cold front is currently centered over SE Louisiana and SW Mississippi. The low will move SE to the far north-central Gulf to near the coast of southeastern Louisiana later this evening, with the cold front extending from it to near 24N95W. The low will reach to near 29N86W by early on Sat, with the cold front extending from it to near 25N90W to 23N95W. The low and front are expected to dissipate by late Sun night. A stronger cold front is forecast to move into the NW Gulf on Tue, and reach from the NE Gulf to the SW Gulf on Wed. Strong north to northeast winds and building seas will follow in the wake of this front. Gale conditions are possible over the far west- central Gulf Tue night and in the far SW Gulf near Veracruz Wed and Wed night. CARIBBEAN SEA... The tail end of a stationary front over the Atlantic Ocean extends as far SW as the Windward Passage, but it does not continue any farther into the Caribbean Sea. Scattered showers and tstorms are occurring over Hispaniola, due to the moisture enhancement provided by the front. The remainder of the Caribbean is relatively dry, with the exception of the far SW Caribbean. The east Pacific monsoon trough is enhancing scattered moderate convection south of 14N and west of 77W, including over Panama and the east coast of central Nicaragua. The most recent ASCAT pass from late Friday morning shows strong NE to E trades in the south-central Caribbean from 11N-13N between 73W-78W, with fresh NE-E winds elsewhere from 10N-17N between 70W-81W. Fresh northeast to east trades will remain across most of the region through Sun night, except for fresh to strong winds along and near the coast of Colombia. Strong high pressure building north of the area will allow for winds and seas to increase early next week over much of the central and eastern Caribbean. ATLANTIC OCEAN... A stationary front passes through 31N54W to 26N60W to the Windward Passage. Behind that front, a cold front extends from 32N55W to 28N63W, then continues as a stationary front 28N63W to 26N70W to 29N79W. Light showers are along the second front. An earlier ASCAT pass showed fresh NE winds to the N of the second front. Scattered moderate showers and isolated tstorms are within 90 nm of the first front between 60W-70W. Scattered moderate convection is along and within 120 nm ahead of the front east of 54W and north of 26N. Surface ridging covers the eastern Atlantic, anchored by a 1030 mb high centered over the Azores. The stationary front extending from near 31N54W to 26N60W to 24N65W to the Windward Passage will gradually weaken through Sat night. The front extending from near 32N55W to 28N63W to 26N70W to 29N79W will quickly move southeast and merge with the northern part of the stationary front by early Sat evening. The western part of the second front will be left behind as a trough over the northwest waters Sat night into early Sun. The trough will move back to the west-northwest from Sun afternoon through Mon as strong high pressure builds southward across the waters north and northeast of the Bahamas. The resultant tight gradient will bring increasing winds along with building seas over these same waters from Sun afternoon through at least Mon evening. These conditions are expected to begin to diminish thereafter into Wed as the next cold front moves into the far northwest waters late Tue night. This front will reach from near 31N72W to near west-central Cuba by late on Wed. Strong north to northeast winds will follow behind this front. $$ Hagen

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