Adrian Linares @Adriansweather 22 minHace 22 minutos(https://pbs.twimg.com/media/DN8__VoUIAEQkk7.jpg)
#TD19 forms over the open Atlantic. Expected to briefly intensify into TS #Rina later today.
Levi Cowan @TropicalTidbits 47 minHace 47 minutos(https://pbs.twimg.com/media/DN86hMJVQAALbiG.jpg)
Tropical Depression Nineteen has formed in the middle of the north Atlantic, and may strengthen a bit, but is no threat to land.
000
WTNT44 KNHC 061433
TCDAT4
Tropical Depression Nineteen Discussion Number 2
NWS National Hurricane Center Miami FL AL192017
1100 AM AST Mon Nov 06 2017
The depression has a sheared appearance with the low-level center
exposed to the west of the mid-level center and the convective
bands. A very recent ASCAT-B overpass indicated that maximum winds
are near 30 kt, which is also in agreement with a Dvorak
classification from TAFB. Based on these data, the initial wind
speed is held at 30 kt.
The depression has slowed down and turned to the left, with the
initial motion estimated to be 015/3 kt. A faster north to
north-northeast motion is expected during the next couple of days
while the system moves in the flow on the west side of a mid-level
ridge. Thereafter, an even faster motion toward the northeast is
forecast when the cyclone becomes embedded in the mid-latitude
westerlies. The model guidance is in good agreement, and the NHC
track forecast is nudged to the west of the previous one to come
into agreement with the latest consensus models.
Although the environment ahead of the depression is not expected to
be particularly conducive for strengthening as a tropical system,
baroclinic enhancements and the expected faster forward speed
should cause the cyclone to gain some strength during the next
couple of days. The global models agree that the cyclone should
merge with a cold front by Wednesday evening, causing extratropical
transition. The extratropical cyclone is expected to gradually
weaken and dissipate in 4 to 5 days. The guidance has trended a
little higher this cycle, and the NHC intensity forecast follows
that trend and lies near the IVCN and HCCA consensus models.
FORECAST POSITIONS AND MAX WINDS
INIT 06/1500Z 29.5N 50.4W 30 KT 35 MPH
12H 07/0000Z 30.8N 50.2W 35 KT 40 MPH
24H 07/1200Z 33.6N 49.8W 40 KT 45 MPH
36H 08/0000Z 37.3N 49.0W 45 KT 50 MPH
48H 08/1200Z 41.4N 46.6W 50 KT 60 MPH
72H 09/1200Z 51.0N 33.5W 45 KT 50 MPH...POST-TROP/EXTRATROP
96H 10/1200Z 57.0N 14.0W 35 KT 40 MPH...POST-TROP/EXTRATROP
120H 11/1200Z...DISSIPATED
$$
Forecaster Cangialosi
Tropical Storm Rina Discussion Number 4
NWS National Hurricane Center Miami FL AL192017
1100 PM AST Mon Nov 06 2017
Despite the low-level center being exposed to the west of the deep
convection, a pair of ASCAT-A and ASCAT-B passes between 00Z and
01Z showed an area of 30-35 kt winds east of the cyclone's center.
Based on the ASCAT data, the depression is upgraded to a tropical
storm with the initial intensity set at 35 kt. The rather
disorganized cloud pattern is consistent with the approximately 20
kt of westerly shear analyzed by UW-CIMSS and the SHIPS model. The
environment is only expected to be marginally conducive for
intensification via diabatic processes, with the shear expected to
remain near 20 kt and the SSTs cooling along the forecast track.
After 24 to 36 hours, cooling upper-tropospheric temperatures and
increasing upper-level divergence suggest that Rina will maintain
its intensity as it begins extratropical transition, which should be
complete between by 72 hours. The new NHC intensity forecast is
similar to the previous one and is close to the HWRF and HCCA aids.
The official forecast shows Rina dissipating by 96 hours in
agreement with global model fields.
The exposed low-level center and ASCAT passes result in high
confidence in the initial position, and Rina has begun to move
more steadily, with an initial motion estimate of 010/06. Rina
should continue to accelerate northward and north-northeastward
during the next 36 to 48 hours between a mid-level ridge to the east
and an upper-level trough to the west. After 48 hours, Rina is
forecast to accelerate further as it enters the mid-latitude
westerlies. The track model guidance has shifted left this cycle,
and the along-track spread is quite large by 72 hours, with the GFS
more than 500 n mi northeast of the ECMWF at that time. The new NHC
track forecast has been adjusted westward and a bit slower, and lies
close to a blend of the GFS and ECMWF solutions to the east of the
TVCA multi-model consensus. Confidence in the details of the track
forecast is lower than usual given the large model spread.
FORECAST POSITIONS AND MAX WINDS
INIT 07/0300Z 30.4N 49.9W 35 KT 40 MPH
12H 07/1200Z 32.4N 49.6W 40 KT 45 MPH
24H 08/0000Z 35.4N 49.0W 45 KT 50 MPH
36H 08/1200Z 39.0N 48.0W 45 KT 50 MPH
48H 09/0000Z 42.3N 46.2W 45 KT 50 MPH
72H 10/0000Z 51.0N 36.0W 40 KT 45 MPH...POST-TROP/EXTRATROP
96H 11/0000Z...DISSIPATED
$$
Forecaster Brennan
Tropical Storm Rina Discussion Number 5
NWS National Hurricane Center Miami FL AL192017
500 AM AST Tue Nov 07 2017
Rina's overall convective cloud pattern has increased is areal
coverage in the eastern semicircle, along with a little more deep
convection having developed near the well-defined low-level center.
In addition, drifting buoy 41506, located about 40 nmi northwest of
the center, reported a pressure of 1011.5 mb at 0600 UTC, and that
datum was used to estimate the central pressure of 1009 mb.
Satellite classifications from TAFB and UW-CIMSS ADT remain at T2.5,
so the intensity is being held at 35 kt for this advisory, which
could be conservative given the lower central pressure.
The initial motion estimate is 005/10 kt. There is no significant
change to the previous forecast track or reasoning. As Rina moves
around the western periphery of a strong deep-layer ridge, the
cyclone should continue to accelerate toward the north today and
then toward the north-northeast on Wednesday. By 48 hours, Rina is
expected to get caught up in the mid-latitude westerlies and
accelerate even more toward the northeast over the cold waters
of the north Atlantic. The NHC track guidance has shifted a little
more to left, so the new official forecast track has also been
nudged in that direction, close to consensus models TVCN and HCCA.
Based on GOES-16 ice physics satellite imagery, the inner-core of
Rina's circulation appears to have tightened up some and has also
become better defined. Some modest strengthening is forecast for
the next 36 h or so due to some baroclinic forcing associated with
an approaching vigorous shortwave trough currently located about 400
nmi to the west. By 48 h, the cyclone will be situated over water
temperatures colder than 20 deg C and within an environment of
increasing deep-layer wind shear. The combination of those two
negative factors are expected is result in Rina becoming an
extratropical cyclone. The NHC intensity forecast is similar to the
HCCA intensity consensus model, and also includes input from the
NOAA Ocean Prediction Center.
FORECAST POSITIONS AND MAX WINDS
INIT 07/0900Z 31.4N 49.8W 35 KT 40 MPH
12H 07/1800Z 33.7N 49.4W 40 KT 45 MPH
24H 08/0600Z 37.0N 48.8W 45 KT 50 MPH
36H 08/1800Z 40.4N 47.8W 45 KT 50 MPH
48H 09/0600Z 44.4N 44.7W 45 KT 50 MPH...POST-TROP/EXTRATROP
72H 10/0600Z 53.0N 32.0W 40 KT 45 MPH...POST-TROP/EXTRATROP
96H 11/0600Z...DISSIPATED
$$
Forecaster Stewart
Tropical Storm Rina Discussion Number 8
NWS National Hurricane Center Miami FL AL192017
1100 PM AST Tue Nov 07 2017
Rina's satellite presentation has acquired some sub-tropical
characteristics this evening as it interacts with a mid- to
upper-level trough to its west and southwest. The center remains
exposed to the south of the primary mass of convection, but the
convection has loosely wrapped around the northwestern portion of
the circulation which has lead to an increase in overall banding.
Recent ASCAT data shows that there has been an overall increase in
the size of the wind field and that the maximum winds have increased
to around 45 kt. Rina is forecast to remain within an environment
of moderate shear and marginal instability during the next 24 hours,
however some additional strengthening is possible tonight and
Wednesday due to interaction with the aforementioned upper-level
trough. By early Thursday, Rina will be moving over much colder
waters and is forecast to become post-tropical. The cyclone should
become a fully extratropical low by late Thursday.
Rina continues to move northward or 010/16 kt. The track forecast
reasoning remains unchanged from the previous advisory. The cyclone
should turn north-northeastward around a large high pressure system
over the eastern Atlantic by late Wednesday, and then begin to
accelerate northeastward on Thursday when it becomes embedded within
strong mid-latitude flow. The track guidance remains in fairly good
agreement and the NHC forecast is again near the various consensus
aids to account for some differences in forward speed among the
global models. The cyclone is expected to dissipate along a frontal
zone over the far north Atlantic in about 72 hours or less.
FORECAST POSITIONS AND MAX WINDS
INIT 08/0300Z 35.4N 48.5W 45 KT 50 MPH
12H 08/1200Z 37.8N 48.1W 50 KT 60 MPH
24H 09/0000Z 41.2N 47.1W 50 KT 60 MPH
36H 09/1200Z 45.7N 43.8W 50 KT 60 MPH...POST-TROPICAL
48H 10/0000Z 51.0N 37.0W 45 KT 50 MPH...POST-TROP/EXTRATROP
72H 11/0000Z...DISSIPATED
$$
Forecaster Brown
Tropical Storm Rina Discussion Number 10
NWS National Hurricane Center Miami FL AL192017
1100 AM AST Wed Nov 08 2017
Rina continues to have some subtropical characteristics with
satellite images showing an asymmetric, comma-cloud structure.
Still, AMSU and model analyses are showing the system as moderately
warm core, and there are no signs of fronts near the core. Thus,
Rina will stay as a tropical cyclone, and 50 kt is kept as the
initial wind speed based on the latest satellite estimates. Little
change in strength is expected before Rina loses all deep convection
within the next 24 hours over chilly waters. The system should
become embedded within a frontal zone over the far north Atlantic in
a day or two, and dissipate west of Ireland. No changes were made to
the previous intensity forecast.
The storm is moving northward a bit faster at 18 kt. A continued
acceleration and a turn to the north-northeast is expected overnight
as Rina moves ahead of a shortwave over the Canadian Maritimes. The
cyclone should move quite rapidly to the northeast by late Thursday
and east-northeast on Friday due to strong mid-latitude flow. The
westward guidance trend in the short-term part of the forecast
is still present, and the new NHC prediction is moved in that
direction in the first 24 hours, with little change thereafter.
FORECAST POSITIONS AND MAX WINDS
INIT 08/1500Z 39.4N 48.7W 50 KT 60 MPH
12H 09/0000Z 42.2N 47.8W 50 KT 60 MPH
24H 09/1200Z 47.1N 44.3W 50 KT 60 MPH...POST-TROPICAL
36H 10/0000Z 52.5N 36.0W 50 KT 60 MPH...POST-TROP/EXTRATROP
48H 10/1200Z 55.5N 22.5W 45 KT 50 MPH...POST-TROP/EXTRATROP
72H 11/1200Z...DISSIPATED
$$
Forecaster Blake
Tropical Storm Rina Discussion Number 12
NWS National Hurricane Center Miami FL AL192017
1100 PM AST Wed Nov 08 2017
A small area of deep convection persists near the center of Rina,
likely supported by very cold temperatures aloft and increasing
upper-level divergence overcoming SSTs less than 20C. The initial
intensity remains 45 kt based largely on continuity from the ASCAT
pass earlier today, as the latest ASCAT passes missed much of Rina's
circulation. Given the maintenance of deep convection, Rina remains
a tropical cyclone, but should not be one for long as vertical
shear is expected to increase above 30 kt and SSTs cool below 15C
along the forecast track in the next 12 hours. The cyclone should
become post-tropical by 12 hours and merge with a frontal zone by 24
hours. Post-tropical Rina should open up into a trough in 36 to 48
hours in the fast westerly flow over the north Atlantic. No change
in strength is forecast prior to dissipation, based on global model
guidance.
Satellite fixes indicate that Rina moved a little to the west of the
previous forecast track in the past few hours, but the cyclone now
appears to be moving north-northeastward or 020/20. The cyclone is
forecast to accelerate northeastward over the next 24 hours as it
becomes embedded in the mid-latitude flow, and an even faster east-
northeastward motion is expected on Friday prior to dissipation. The
new NHC track forecast has been adjusted to the left and is closer
to the ECMWF model in the short range, since that model has best
handled the recent motion of Rina. At 24 to 36 hours, the NHC
forecast lies to the left of the latest multi-model consensus aids.
The track, intensity and structure forecasts of Rina during its
post-tropical phase have been coordinated with the NOAA Ocean
Prediction Center.
FORECAST POSITIONS AND MAX WINDS
INIT 09/0300Z 42.5N 48.3W 45 KT 50 MPH
12H 09/1200Z 45.7N 46.5W 45 KT 50 MPH...POST-TROPICAL
24H 10/0000Z 51.0N 40.0W 45 KT 50 MPH...POST-TROP/EXTRATROP
36H 10/1200Z 55.0N 26.5W 45 KT 50 MPH...POST-TROP/EXTRATROP
48H 11/0000Z...DISSIPATED
$$
Forecaster Brennan