Tropical Weather Discussion

000 
axnt20 knhc 231207
twdat 

Tropical weather discussion
NWS National Hurricane Center Miami FL
807 am EDT sun Sep 23 2018

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 
1115 UTC.

...Special features...

Tropical Storm Kirk centered near 9.1n 28.0w at 23/0900 UTC or
400 nm SSW of the southernmost Cabo Verde islands moving W at 16
kt. Estimated minimum central pressure is 1006 mb. Maximum
sustained wind speed is 35 kt with gusts to 45 kt. Some 
strengthening is forecast during the next day or two.
Weakening is likely during the middle to latter part of the week.
Scattered moderate to strong convection is from 08n-12n between 
25w-32w. See the latest NHC forecast/advisory under AWIPS/WMO 
headers miatcpat2/wtnt32 knhc for more details.

Tropical Depression Eleven centered near 14.5n 55.0w at 23/0900
UTC or 360 nm ENE of the Windward Islands moving NW at 5 kt.
Estimated minimum central pressure is 1009 mb. Maximum sustained
wind speed is 25 kt with gusts to 35 kt. A slow west-northwest to
northwest motion is expected until the system dissipates in a day
or so. Scattered moderate convection is noted from 12n-15n 
between 52w-55w. See the latest NHC forecast/advisory under 
AWIPS/WMO headers miatcpat1/wtnt31 knhc for more details.

Satellite imagery indicates that a non-tropical low pressure 
system currently located about 1000 miles west-southwest of the 
Azores is producing gale-force winds with some associated showers 
and thunderstorms. Conditions appear conducive for this system to 
acquire some subtropical or tropical characteristics during the 
next day or so while meandering over the central Atlantic Ocean, 
and the low could become a subtropical or tropical cyclone before 
it is overtaken and absorbed by a cold front late Tuesday or 
Wednesday. The system has a high chance of tropical cyclone 
formation within the next 48 hours. Please refer to the latest 
tropical weather outlook under AWIPS/WMO headers miatwoat/abnt20 
knhc for more information.

A cold front extends from a 1004 mb low pressure located N of the
area near 34n46w to 31n40w to 24n50w to 27n60w. The most recent 
scatterometer data provide observations of minimal gale-force 
winds N of 30n within 60 nm E of front with seas 11-13 ft. These 
conditions are expected to decrease below gale shortly at 23/1200
UTC.

...Tropical waves...

A tropical wave has its axis along 46w from 03n-16n and is moving
west at 10-15 kt. The wave corresponds nicely with a maximum in 
tpw imagery. Model analyses depict an associated 700 mb trough 
along 44w. Isolated moderate convection is located from 03n-14n 
between 40w-50w. 

A Central American tropical wave has its axis along 89w from 08n-
20n, moving west around 10 kt. The 700 mb trough associated with 
this wave is well depicted in model guidance, and tpw imagery 
shows abundant moisture in its environment. Widely scattered 
moderate convection is south of 20n between 85w-92w. 

...Monsoon trough/ITCZ...

The monsoon trough extends from the African coast near 13n17w to 
10n20w. It continues west of T.S. Kirk near 06n30w to 05n34w. The
ITCZ begins near 05n34w to 04n40w to 05n44w, then resumes near 
05n48w to the South American coast near 04n51w. Aside from the 
convection associated with the tropical wave and cyclones across 
the area, widely scattered moderate convection is located S of 75
the monsoon from 04n-11n between 10w-18w.

...Discussion...

Gulf of Mexico...

An upper-level cyclonic circulation is centered near 25n87w. This
feature is enhancing convection across the eastern Gulf waters 
mainly along 84w. To the west, a surface trough is analyzed along 
91w from 24n-29n. Scattered showers are noted along the trough. A 
cold front is entering the northwest Gulf enhancing convection 
north of 25n and west of 95w. This front is likely to stall and 
dissipate today. Gentle to moderate E to se winds and seas 3 ft or
less will prevail across most of the Gulf of Mexico through the 
middle of next week. A surface trough will develop over the 
Yucatan Peninsula each evening, shift W over the SW Gulf each 
night, then dissipate by morning. Moderate to fresh winds will 
accompany this trough. 

Caribbean Sea...

A tropical wave is moving across Central America, and a portion 
of the wave's convection is over the W Caribbean. Please see the 
tropical waves section for more details.

The eastern Pacific monsoon trough combined with diffluence aloft
continues to enhance convection over portions of Panama and the
waters of the southwest Caribbean from the coasts of Panama and
Costa Rica northward to 13n and eastward to 78w. Plenty of 
moisture will persist over the extreme southwest Caribbean, Panama
and Costa Rica through the weekend. Elsewhere, fresh to strong 
winds prevail over the central Caribbean. These winds will 
diminish across most of the basin by tonight. 

Atlantic Ocean...

Currently, there are two tropical cyclones and a tropical wave
between the West Coast of Africa and the Lesser Antilles. Please 
see the special features and tropical waves sections for more 
details.

A broad 1010 mb low is centered near 28n67w. A surface trough 
runs through the low from 30n64w to the low center to 26n72w. 
Scattered showers are noted along the trough and near the low. 
Unfavorable upper-level winds and dry air are expected to limit 
development today, but conditions could become more conducive for
some development of this system on Monday or Tuesday while it 
moves westward and west-northwestward over the southwestern 
Atlantic Ocean. By the middle of next week, strong upper-level 
winds are likely to limit additional development as the system 
turns northward and moves closer to the southeastern coast of the 
United States. This feature has a low chance of tropical cyclone 
formation during the next 48 hours.

The remainder of the basin is under the influence of a surface 
ridge, anchored by a 1028 mb high centered near 40n21w. 

For additional information please visit 
http://www.Hurricanes.Gov/marine

$$
Formosa


		
		

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