EPAC: GENEVIEVE - Post-Tropical

[EquusStorm]

A day too late to catch its impressive peak but always nice to get EPac recon nevertheless

[1900hurricane]

Thinking about 90 kt/960 mb for Genevieve when recon gets there.

[CrazyC83]

Much weaker than thought. 70 kt and 969 mb based on this pass.

[1900hurricane]

Thinking about 90 kt/960 mb for Genevieve when recon gets there.

Is it too late to add 10 mb and subtract 10 kt?

[Kingarabian]

ADT not too far off from recon. So that's good news in regards to Dvorak accuracy.

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 9.0
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 19 AUG 2020 Time : 192032 UTC
Lat : 21:19:47 N Lon : 109:46:47 W


CI# /Pressure/ Vmax
4.7 / 969.9mb/ 82.2kt


Final T# Adj T# Raw T#
4.7 5.3 5.3

Estimated radius of max. wind based on IR : 22 km

Center Temp : +8.3C Cloud Region Temp : -54.8C

Scene Type : EYE

[Yellow Evan]

This is more or less what Blanca 15 was like when it intercepted Recon so I'm not too surprised here.

[wx98]

Down to Cat 1 per recon:

3:00 PM MDT Wed Aug 19
Location: 21.4°N 110.1°W
Moving: NNW at 8 mph
Min pressure: 974 mb
Max sustained: 90 mph

[EquusStorm]

Way closer to Baja than I figured, good thing it's a lot weaker.

[ClarCari]

Idk how to post pics yet, but the 9PM MDT NHC forecast track has Genevieve curving back a little north toward maybe California as a TD or lower. Either way this could maybe bring some much needed rain to the Cali fires!

[Astromanía]

Well two confirmed deaths in Los Cabos due to Genevieve

[Yellow Evan]

ZCZC MIATCDEP2 ALL
TTAA00 KNHC DDHHMM

Hurricane Genevieve Discussion Number 15
NWS National Hurricane Center Miami FL EP122020
900 PM MDT Wed Aug 19 2020

Genevieve's infrared satellite presentation has continued to become
less defined since the previous advisory, with microwave imagery
indicating that the eyewall has completely eroded in the southern
semicircle. Satellite intensity estimates have decreased as a
result, with TAFB and SAB now assessing intensity estimates of
T4.5/77 kt. Therefore, the initial intensity has been lowered to 75
kt.

Genevieve has made a slight right-of-track jog, and the initial
motion estimate is now 345/06 kt. The recent north-northwestward
motion is expected to be temporary and is likely due to the outer
circulation interacting with the mountainous terrain of Baja
California Sur. However, the global and regional models remain in
good agreement that the deep-layer subtropical ridge to the north of
the hurricane is expected to turn Genevieve back toward the
northwest by early Thursday. That motion is then forecast to
continue through the end of the 5-day forecast period. On this
track, the center of Genevieve will pass just to the southwest or
west of the southern portion of the Baja California peninsula
overnight and on Thursday. The new NHC track forecast is a little to
the right or east of the previous advisory track through 24 hours to
account for the recent northward jog. Thereafter, the new forecast
track is similar to the previous advisory and lies near the eastern
edge of the model guidance suite.

Genevieve will continue to move over gradually decreasing sea
surface temperatures (SSTs) and shallower warm waters over the next
day or so, which will produce cold upwelling, resulting in slow
weakening during the next 24-36 hours. Thereafter, the cyclone will
be moving over sub-25 deg C SSTs, which will induce a faster rate
of weakening, with Genevieve forest to degenerate into a
post-tropical remnant low by 72 hours. The official intensity
forecast is similar to the IVCN simple consensus aid, due to the low
vertical shear conditions that are expected to persist through 36-48
hours, and is above the NOAA-HCCA corrected-consensus model.

Key Messages:

1. The center of Genevieve is forecast to pass just west of the Baja
California peninsula tonight and Thursday. Tropical storm
conditions are expected to spread across southern Baja California
Sur through Thursday. Hurricane conditions are expected within the
Hurricane Warning area tonight and continuing into Thursday.

2. Heavy rainfall from Genevieve may lead to life-threatening flash
flooding and mudslides across portions of far southern Baja
California Sur through Thursday.

3. Large swells generated by Genevieve will affect portions of
the west-central coast Mexico and the coast of the southern Baja
California peninsula through Friday.

FORECAST POSITIONS AND MAX WINDS

INIT 20/0300Z 22.0N 110.1W 75 KT 85 MPH
12H 20/1200Z 22.8N 110.8W 70 KT 80 MPH
24H 21/0000Z 23.6N 112.1W 65 KT 75 MPH
36H 21/1200Z 24.5N 113.5W 60 KT 70 MPH
48H 22/0000Z 25.7N 115.3W 50 KT 60 MPH
60H 22/1200Z 26.8N 117.1W 40 KT 45 MPH
72H 23/0000Z 28.0N 119.0W 30 KT 35 MPH...POST-TROP/REMNT LOW
96H 24/0000Z 29.5N 121.1W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 25/0000Z 31.1N 121.9W 20 KT 25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Stewart

NNNN

[Yellow Evan]

ZCZC MIATCDEP2 ALL
TTAA00 KNHC DDHHMM

Hurricane Genevieve Discussion Number 16
NWS National Hurricane Center Miami FL EP122020
300 AM MDT Thu Aug 20 2020

Recent microwave overpasses and conventional enhanced infrared
satellite imagery indicate that just a fragment of Genevieve's
eyewall remains in the northeast quadrant. Subjective satellite
intensity estimates have once again decreased as well as an earlier
SATCON analysis from UW-CIMSS. Consequently, the initial intensity
has been lowered to 70 kt based on a blend of these data.

Genevieve will continue traversing gradually cooler oceanic
temperatures today and Friday which will aid in additional spin
down of the cyclone. Afterward, Genevieve is forecast to move
over much cooler SSTs, less than 25 degrees Celsius, which should
induce a swifter weakening trend, and ultimately, cause the cyclone
to degenerate into a remnant low in 60 hours. The new NHC
intensity forecast is based primarily on the HFIP Corrected
Consensus Intensity model through 48 hours, then is adjusted
to agree more with the global model guidance.

The initial motion is estimated to be north-northwestward, or
330/6 kt, but a turn toward the northwest is forecast today. This
general motion should continue through the remainder of the
forecast period. On this track, the center of Genevieve will pass
just to the southwest or west of the southern portion of the Baja
California peninsula later today. The updated forecast is near the
middle of the large-scale and regional model envelope, and just to
the right of the previous advisory track.

Genevieve's wind radii were adjusted based on a 0422 UTC METOP-A/B
ASCAT overpass.

Key Messages:

1. The center of Genevieve is forecast to pass just west of the Baja
California peninsula today. Tropical storm conditions are
occurring over southern Baja California Sur and should continue
today. Hurricane conditions will continue for the next several
hours within the Hurricane Warning area.

2. Heavy rainfall from Genevieve may lead to life-threatening flash
flooding and mudslides across portions of far southern Baja
California Sur through today.

3. Large swells generated by Genevieve will affect portions of
the west-central coast Mexico and the coast of the southern Baja
California peninsula through Friday.


FORECAST POSITIONS AND MAX WINDS

INIT 20/0900Z 22.5N 110.4W 70 KT 80 MPH
12H 20/1800Z 23.3N 111.4W 65 KT 75 MPH
24H 21/0600Z 24.4N 112.9W 55 KT 65 MPH
36H 21/1800Z 25.5N 114.5W 45 KT 50 MPH
48H 22/0600Z 26.7N 116.3W 35 KT 40 MPH
60H 22/1800Z 27.9N 118.3W 30 KT 35 MPH...POST-TROP/REMNT LOW
72H 23/0600Z 28.8N 120.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 24/0600Z 30.4N 121.6W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 25/0600Z...DISSIPATED

$$
Forecaster Roberts

NNNN

[Yellow Evan]

ZCZC MIATCDEP2 ALL
TTAA00 KNHC DDHHMM

Hurricane Genevieve Discussion Number 17
NWS National Hurricane Center Miami FL EP122020
900 AM MDT Thu Aug 20 2020

Genevieve's overall satellite appearance continues to slowly
degrade, with a shrinking central dense overcast and dry, stable air
being drawn into the eastern portion of the circulation. The Dvorak
data-T numbers from TAFB, SAB, and the UW-CIMSS ADT have decreased
to 3.5. However, since the CI numbers from these respective analyses
are 4.5, the initial intensity of 65 kt will be based off a blend of
those two values.

Genevieve is forecast to move over gradually cooler waters during
the next 24 h, so a slow weakening trend is expected to continue
through that time. Beyond 24 h, the cyclone will cross the 26C SST
isotherm and reach temperatures below 24C after 48 h. This should
result in a faster rate of weakening, and the cyclone is expected to
degenerate into a remnant low by 60 h. The latest NHC intensity
forecast is essentially an update of the previous one, and is near
the HFIP corrected consensus HCCA.

Genevieve has made its anticipated turn toward the northwest and has
accelerated slightly to 10 kt. This general motion is expected to
continue until the cyclone dissipates later in the forecast
period. On this track, Genevieve will move parallel to the coast of
the southern Baja California peninsula today and then begin to move
away from the peninsula late tonight. The NHC forecast track is
very little changed from the previous one, with the only notable
difference being a slightly faster forward speed. This forecast is
very near the tightly clustered track guidance.

Key Messages:

1. The center of Genevieve is forecast to pass just west of the Baja
California peninsula today. Tropical storm conditions will continue
over southern Baja California Sur through today, and possibly linger
into tonight.

2. Continued heavy rainfall from Genevieve may lead to life-
threatening flash flooding and mudslides across portions of far
southern Baja California Sur through today.

3. Large swells generated by Genevieve will affect portions of
the west-central coast of Mexico and the coast of the southern Baja
California peninsula through Friday.

FORECAST POSITIONS AND MAX WINDS

INIT 20/1500Z 23.3N 111.4W 65 KT 75 MPH
12H 21/0000Z 24.1N 112.5W 60 KT 70 MPH
24H 21/1200Z 25.3N 114.1W 50 KT 60 MPH
36H 22/0000Z 26.6N 115.8W 40 KT 45 MPH
48H 22/1200Z 27.8N 117.8W 30 KT 35 MPH
60H 23/0000Z 28.8N 119.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 23/1200Z 29.7N 121.4W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 24/1200Z 31.1N 122.5W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 25/1200Z...DISSIPATED

$$
Forecaster Latto

NNNN

[CrazyC83]

Pressure is much lower than thought - about 982 mb - yet the winds do only support about 50-55 kt right now.

[cycloneye]

Tropical Storm Genevieve Discussion Number 18
NWS National Hurricane Center Miami FL EP122020
300 PM MDT Thu Aug 20 2020

Dry and stable air continues to be drawn into Genevieve's
circulation. This is noted by a slow erosion of convection over
the southwestern semicircle, and warming cloud tops over
the past several hours, indicating weakening. An Air Force Reserve
Hurricane Hunter aircraft investigating the system this afternoon
measured peak 700 mb flight-level winds of 71 kt, which reduce to
64 kt at the surface, with peak SFMR winds of 57 kt. A blend of
these values supports lowering the initial intensity to 60 kt.

Genevieve should continue to gradually weaken as it moves over
progressively lower oceanic temperatures. By Friday, the cyclone is
expected to cross the 26 C SST isotherm, and it will reach waters
cooler than 24 C by early Saturday. These much cooler waters should
cause the cyclone to degenerate to a remnant low by late Saturday.
The latest NHC intensity forecast is little changed from the
previous one, and is near the HFIP corrected consensus HCCA.

Genevieve continues to move northwestward at 10 kt, paralleling the
coast of the southern Baja California Peninsula. This general motion
is expected to continue until the cyclone dissipates later in the
forecast period. On this track, Genevieve will begin to move away
from the peninsula tonight. The NHC forecast track is very little
changed from the previous one and is in the middle of the tightly
clustered track guidance.

Key Messages:

1. The center of Genevieve is forecast to pass just west of the Baja
California peninsula through this evening, with tropical storm
conditions expected to continue over portions of this area during
this time.

2. Rainfall from Genevieve will continue to decrease in intensity
over southern Baja California Sur, although some instances of flash
flooding and mudslides remain possible through this evening.

3. Large swells generated by Genevieve will affect portions of
the west-central coast of Mexico and the coast of the southern Baja
California peninsula through Friday.


FORECAST POSITIONS AND MAX WINDS

INIT 20/2100Z 23.9N 112.4W 60 KT 70 MPH
12H 21/0600Z 24.8N 113.7W 50 KT 60 MPH
24H 21/1800Z 26.1N 115.3W 40 KT 45 MPH
36H 22/0600Z 27.4N 117.2W 30 KT 35 MPH
48H 22/1800Z 28.6N 119.3W 25 KT 30 MPH...POST-TROP/REMNT LOW
60H 23/0600Z 29.4N 120.9W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 23/1800Z 30.3N 122.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 24/1800Z...DISSIPATED

$$
Forecaster Latto

[wxman57]

Hey! Recon found a circulation in at least 1/3 of the named systems!

[zeehag]

according to mexican info, 6 dead in this one, in south baja...didnt see true damages but there is a lotta flooding. first two deaths were a swimmer and a lifeguard. the other 4 i donot know situations.

[galaxy401]

In Arizona, we got a crazy monsoon storm last night. That might be the first significant rainfall we had all summer. We have been stuck in a miserable heat wave for weeks now. I wonder if the increased moisture the last several days has to do with Genevieve. If so, thanks Genevieve for some showers.

[EquusStorm]

I wonder if there will be some enhanced moisture in southern CA as this wanders off the coast. Could certainly use some assistance there

[Yellow Evan]

789
WTPZ42 KNHC 211436
TCDEP2

Tropical Storm Genevieve Discussion Number 21
NWS National Hurricane Center Miami FL EP122020
900 AM MDT Fri Aug 21 2020

Genevieve continues to gradually weaken while it encounters cooler
waters and light to moderate southerly shear. Deep convection
associated with the system dissipated around the time of the
previous advisory, and the cyclone is now comprised of a swirl of
low- to mid-level clouds. The initial intensity has been reduced to
40 kt, which is a blend of the latest TAFB Dvorak T- and CI-numbers.
Genevieve is expected to continue to gradually weaken today as it
moves over SSTs of 24-25 degrees Celsius. It is unlikely that
organized deep convection will return, and Genevieve is expected to
become a post-tropical cyclone later today. The cyclone's winds are
forecast to drop below tropical storm strength within 12 hours, and
the remnant low should continue to spin down over cooler waters west
of the Baja California peninsula during the next couple of days.
The global models indicate that the remnant low will dissipate in
about 72 hours.

Genevieve is moving northwestward at about 9 kt. The cyclone should
continue on this general heading over the next couple of days as it
moves around the southwestern side of a mid-level ridge over
northern Mexico. The remnant low is forecast to decelerate by Sunday
as it becomes vertically shallow and is steered by the weaker
low-level flow.

Large swells from Genevieve that are spreading northward along
portions of the west coast of the Baja California peninsula will
gradually subside on Saturday.


FORECAST POSITIONS AND MAX WINDS

INIT 21/1500Z 25.0N 114.8W 40 KT 45 MPH
12H 22/0000Z 26.1N 116.2W 30 KT 35 MPH...POST-TROP/REMNT LOW
24H 22/1200Z 27.6N 118.3W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 23/0000Z 28.7N 120.2W 20 KT 25 MPH...POST-TROP/REMNT LOW
48H 23/1200Z 29.5N 121.6W 20 KT 25 MPH...POST-TROP/REMNT LOW
60H 24/0000Z 30.3N 122.3W 15 KT 15 MPH...POST-TROP/REMNT LOW
72H 24/1200Z...DISSIPATED

$$
Forecaster Brown