AXNT20 KNHC 211711
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
111 PM EDT Sat Sep 21 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
Tropical Storm Jerry is centered near 22.0N 65.0W at 21/1500 UTC
or about 615 nm S of Bermuda, moving NW at 12 kt. Estimated
minimum central pressure is 999 mb. Maximum sustained wind speed
is 55 kt with gusts to 65 kt. Numerous strong convection is within
150 nm of the center NE quad, 180 nm SE quad, 90 nm SW quad and
nothing in the NW quad. Scattered moderate showers are elsewhere
from 19N-25N between 61W-67W. Jerry will pass well north of
Puerto Rico today. Jerry is forecast to turn northward on Sunday,
passing well east of the SE Bahamas before accelerating toward the
northeast early next week. Little change in strength is forecast
during the next several days. See the latest NHC forecast/advisory
under AWIPS/WMO headers MIATCMAT5/WTNT25 KNHC or
www.hurricanes.gov for more details.
An Atlantic tropical wave with axis along 56W S of 16N is moving
W at 15-20 kt. Model guidance and satellite imagery depict this
wave well. Clusters of scattered moderate convection are from 07N-
15N between 47W-58W and also near Trinidad. The latest ASCAT pass
shows that the wave contains strong to near gale force winds on
both sides of the wave axis from 11N-16N. The wave is forecast to
cross the Windward Islands on Sunday. Environmental conditions
appear to be conducive for some development, and a tropical
depression could form later this weekend or early next week.
Regardless of development, heavy rainfall is possible over much of
the Lesser Antilles this weekend along with gusty winds, and
interests on those islands and Puerto Rico should monitor the
progress of this disturbance.
A tropical wave over west Africa with axis along 12/13W S of 19N
is moving W at 10-15 kt. Scattered moderate to isolated strong
convection is seen from 04N-14N between 07W-18W. The tropical
wave is forecast to move off the west coast of Africa by Sunday
morning. Environmental conditions are expected to be conducive for
development, and a tropical depression or tropical storm is
likely to form early next week while the wave moves westward
across the eastern tropical Atlantic.
An Atlantic tropical wave with axis along 29W S of 19N is moving
W at 15-20 kt. Model guidance and satellite imagery depict this
wave well. Scattered moderate to isolated strong convection is
seen from 05N-16N between 21W-38W.
The tropical wave that was previously along 82W has been removed
from the analysis.
The monsoon trough extends from the coast of Guinea-Bissau near
12N16W to 09N25W to 07N37W. The ITCZ extends from 07N37W to 08N48W
to 09N54W. Aside from the convection mentioned in the sections
above, no other significant convection is noted.
GULF OF MEXICO...
Surface ridging prevails across the basin, anchored by a 1026 mb
high centered over North Carolina near 35N81W. The high is keeping
an east to southeast flow across much of the basin. Latest
scatterometer data depicts fresh to strong E winds over the
eastern Gulf north of 24N and east of 90W, with gentle to moderate
winds farther south and west. An upper-level trough axis extends
from just offshore North Carolina to Daytona Beach Florida to the
east-central Gulf of Mexico. Upper-level diffluence just to the
southeast of this trough axis is enhancing scattered showers and
tstorms over the SE Gulf of Mexico, Florida Straits and Florida
Keys from 23N-26N between 81W-89W.
High pressure centered along the eastern seaboard of the U.S.
will dominate the Gulf waters through Sunday, causing a
continuation of fresh to strong E winds over the eastern Gulf and
building seas. New high pressure will develop over the northern
Gulf by early next week with the pressure gradient slackening, and
wind and sea conditions improving through the middle of the week.
A broad 1011 mb surface low just east of the eastern tip of
Jamaica has been weakening over the last 12 hours. A weak surface
trough extends from the E tip of Cuba to the low to 15N76W.
Scattered showers and tstorms are over portions of E Cuba,
Jamaica, western Haiti, and nearby waters. Farther west, a surface
trough is over the NW Caribbean extending from 21N86W to 14N82W.
Scattered showers and tstorms are from 20N-22N between 81W-87W. In
the far SW Caribbean, the East Pacific monsoon trough is
enhancing scattered moderate to isolated strong convection from
08.5N-12.5N between 68W-81W, including over NW Venezuela and N
Colombia. Latest scatterometer data depicts gentle winds across
much of the basin.
Large northerly swell will continue to pass through the NE
Caribbean passages through Sunday. A strong tropical wave along
56W will cross the Windward Islands on Sunday, bringing squally
weather. This system has a medium chance of developing into a
tropical cyclone during the next 48 hours. See the Special
Features section above for details.
Refer to the sections above for details on the tropical waves and
Tropical Storm Jerry.
A cold front extends across the central and western Atlantic from
32N56W to 29N60W. A stationary front continues from 29N60W to the
Central Bahamas near 24N76W. Scattered moderate to isolated strong
convection is within 180 nm SE of the front between 53W-63W and
north of 25N. Similar moderate to strong convection is over
portions of the Central and SE Bahamas. Cloudiness and scattered
light to moderate showers extend to 180 nm NW of the stationary
front, including over portions of the NW Bahamas. Partly cloudy
skies and better weather are found to the NW of a line from
Bermuda to West Palm Beach Florida, due to the influence of the
1026 mb surface high over North Carolina. Due to the pressure
gradient across the western Atlantic, strong NE winds around 20-25
kt cover the entire area north of the front from 25N-30N between
61W and the east coast of Florida, as shown by the latest ASCAT
A 1024 mb surface high is centered near 32N40W. A large upper-
level low near 17N47W covers the area from 15N-24N between 38W-
53W. The upper-low is inducing scattered moderate convection from
20N-26N between 43W-49W. A cold front over the NE Atlantic enters
the area near 32N19W and extends SW to 27N33W. No significant
convection is with the front. However, a distinct wind shift is
seen across the front, with moderate to locally fresh N to NE
winds extending to 150 nm N of the front.
Tropical Storm Jerry is near 22.0N 65.0W, 999 mb, at 11 AM EDT
moving NW at 12 kt. Maximum sustained winds are 55 kt with gusts
to 65 kt. Jerry will move to near 25N67W Sun morning, near 28N67W
Mon morning, and near 31N66W Tue morning, with little change in
intensity expected. Meanwhile, large remnant northerly swell will
continue to impact the Atlantic forecast waters N and E of the
Bahamas through the weekend.