Home


000
AXNT20 KNHC 201020
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
620 AM EDT Fri Oct 20 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 0600 UTC surface analysis and satellite imagery through 0915 UTC.


...TROPICAL WAVES... A tropical wave extends from 08N43W to 18N40W moving W at 10-15 kt. The wave coincides with 700 mb troughing between 34W-45W and a maximum in 850 mb relative vorticity along the wave axis near 16N. Scattered moderate convection is from 10N-23N between 28W- 41W. This convection is being enhanced by an upper level low centered N of the wave axis near 23N41W.

A tropical wave extends from 10N70W to 20N72W moving W at 10-15 kt. The wave coincides with shortwave 700 mb troughing between 68W-74W and a weak maximum in 850 mb relative vorticity along the wave axis near 16N. Scattered moderate convection is from 14N- 19N between 70W-77W.

A tropical wave extends from 09N79W to 20N80W moving W at 10-15 kt. The wave coincides with 700 mb troughing between 76W-83W and a weak maximum in 850 mb relative vorticity along the wave axis near 17N. Widely scattered moderate convection is from 09N-20N between 78W-84W.


...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 08N13W to 06N23W. The Intertropical Convergence Zone axis extends from 06N23W to 05N30W to 08N42W to 07N58W. Widely scattered moderate convection is within 90 nm either side of a line from 03N08W to 10N16W. Scattered moderate convection is from from 04N-09N between 21W-35W. Isolated moderate convection is from 08N-12N between 53W-61W.


...DISCUSSION...

GULF OF MEXICO... Middle to upper level ridging is noted on water vapor imagery over much of the Gulf while to the west...an upper level trough axis extends over the southern Plains to a base over the NW Gulf near 27N96W. The troughing aloft supports scattered showers and tstms occurring within 90 nm either side of a line from 23N90W to 30N94W...including inland portions of eastern Texas and far western Louisiana. Farther south...additional isolated showers and tstms are occurring S of 22N between 91W-95W in the vicinity of a surface trough boundary extending from 18N93W to 22N97W. Otherwise...much of the basin lies on the southern periphery of a surface ridge anchored across the SE CONUS by a 1025 mb high. Moderate to occasional fresh NE to E winds prevail E of 90W and gentle to moderate E to NE winds prevail in the vicinity of the surface troughing. By Saturday...moderate to fresh E-SE flow will re-establish itself across the Gulf as an area of low pressure develops across the central Plains.

CARIBBEAN SEA... An upper level anticyclone is centered over the western Caribbean near 17N82W providing an overall divergent environment W of 70W. The divergence along with two tropical waves moving across the basin are generating scattered showers and tstms from 14N-20N between 70W-78W...and from 09N-22N between 78W-89W...including inland portions of Central America. Plenty of atmospheric moisture in associated with the ridge and will likely continue to produce relatively active convection through the weekend. Otherwise... fresh to strong trades prevail E of 80W as the pressure gradient strengthens while strong high pressure moves off the Mid-Atlc coast and into the western North Atlc. The trades are expected to remain strong through Monday night.


...HISPANIOLA... A tropical wave will skirt across the island today bringing scattered showers and tstms to southern portions of the island and the adjacent southern coastal waters. Fresh to strong trades are expected through the weekend as high pressure builds in across the region.

ATLANTIC OCEAN... A warm front extends from 34N60W SW into a 1011 mb low centered near 32N65W. A cold front continues SW to 28N72W then becomes stationary to the central Bahamas near 25N78W. A pre-frontal surface trough extends from the cold front near 28N71W to eastern Cuba near 21N77W. The low and associated boundaries continue to provide focus for scattered showers and tstms N of 30N between 50W-65W...and scattered showers and isolated tstms from 24N-30N between 62W-75W generally E of the front. This system is supported aloft by an upper level trough extending from 34N66W to 26N74W and a reinforcing upper level trough swinging east- southeastward off the Carolina coast this morning. The remainder of the eastern Atlc is under the influence of a surface ridge anchored by a 1025 mb high centered near 31N33W.

For additional information please visit http://www.hurricanes.gov/marine

$$ HUFFMAN

Home