EPAC: CRISTINA - Post-Tropical

[aspen]

Starting to doubt it’s dry air ingestion, because new hot towers are firing off near the center and around that possible eye. Cristina will likely be upgraded to a hurricane tonight.

[Kingarabian]

There's a new big burst of convection just south of what I presume to be the eye. It is pushing out the dry air.

[al78]

There's a new big burst of convection just south of what I presume to be the eye. It is pushing out the dry air.
https://i.imgur.com/5DgxSZv.jpg

That looks like a hurricane.

[Kingarabian]

There's a new big burst of convection just south of what I presume to be the eye. It is pushing out the dry air.
https://i.imgur.com/5DgxSZv.jpg

That looks like a hurricane.

Yeah it definitely is.

[Yellow Evan]

Eye is finally clearing out. Worthy of a T4.0 now (embedded in DG with OW eye). This might have a round of RI up its sleeve though time is running out.

[Kingarabian]

CI# /Pressure/ Vmax
2.9 / 999.8mb/ 43.0kt


Final T# Adj T# Raw T#
2.9 3.3 5.3

[StruThiO]

It's about time

[aspen]

Convection is a little shallow despite a clear organizational trend in the right direction. Hopefully diurnal max gets things going.

[Kingarabian]

Convection is a little shallow despite a clear organizational trend in the right direction. Hopefully diurnal max gets things going.

Yeah the issue is just that dry air keeps getting in.

[Kingarabian]

She's for sure not a looker.

[Yellow Evan]

09/2330 UTC 18.2N 111.3W T4.5/4.5 CRISTINA -- East Pacific

[aspen]

Just get to hurricane status and we’ll all be happy.

[1900hurricane]

Still 60 kt for 00Z for now.

EP, 05, 2020071000, , BEST, 0, 181N, 1114W, 60, 993, TS, 34, NEQ, 70, 60, 60, 60, 1010, 150, 25, 0, 0, E, 0, , 0, 0, CRISTINA, D, 0, , 0, 0, 0, 0, genesis-num, 010,
EP, 05, 2020071000, , BEST, 0, 181N, 1114W, 60, 993, TS, 50, NEQ, 30, 30, 0, 0, 1010, 150, 25, 0, 0, E, 0, , 0, 0, CRISTINA, D, 0, , 0, 0, 0, 0, genesis-num, 010,

[Yellow Evan]

Still 60 kt for 00Z for now.

EP, 05, 2020071000, , BEST, 0, 181N, 1114W, 60, 993, TS, 34, NEQ, 70, 60, 60, 60, 1010, 150, 25, 0, 0, E, 0, , 0, 0, CRISTINA, D, 0, , 0, 0, 0, 0, genesis-num, 010,
EP, 05, 2020071000, , BEST, 0, 181N, 1114W, 60, 993, TS, 50, NEQ, 30, 30, 0, 0, 1010, 150, 25, 0, 0, E, 0, , 0, 0, CRISTINA, D, 0, , 0, 0, 0, 0, genesis-num, 010,

NHC has been rather bullish with this storm and now this?

[1900hurricane]

TAFB was 3.0/3.5 apparently.

EP, 05, 202007100000, 10, DVTS, CI, , 1810N, 11140W, , 3, 55, 2, 994, 2, DVRK, , , , , , , , , , , , , , E, TAFB, SK, VI, 5, 3035 /////, , , GOES17, CSC, T,

[cycloneye]

Tropical Storm Cristina Discussion Number 14
NWS National Hurricane Center Miami FL EP052020
900 PM MDT Thu Jul 09 2020

Cristina's satellite presentation has degraded somewhat during the
past several hours, with deep convection on the wane and some
evidence of dry air near the center. Still, microwave data does
show a large banding pattern with a mid-level core present,
suggesting there might be more than meets the eye than just
conventional satellite imagery. The current intensity of the storm
is difficult to ascertain, as estimates from generally credible
techniques range from 45 kt to 77 kt on this package. It is
probably best to keep the initial wind speed 60 kt for now, and we
will see if the intensity becomes more clear overnight.

The storm has about a day over marginally warm waters in light
shear conditions before SSTs begin to cool, and eventually
more significant dry air is entrained into the inner core. Thus
some strengthening is anticipated on Friday, and Cristina should
start a gradual weakening over the weekend through early next week.
The cyclone should have a challenging time producing convection over
sub-23C waters, which happens in about 72 hours, so that is the
time chosen for post-tropical transition. This is earlier than the
previous forecast and best matches a GFS/ECMWF blend. No
significant changes were made to the intensity forecast with
guidance in good agreement at this time.

Christina continues moving west-northwestward at about 10 kt.
A mid-level ridge centered over the southwestern U.S. is expected
to strengthen over the next day or so, which should force
the storm in a similar direction but with a slight increase in
forward speed. Over the weekend, as the cyclone weakens, a gradual
turn to the west is expected. The forecast track is a little slower
than the previous one at long range, otherwise the track is
basically an update of the earlier track prediction.


FORECAST POSITIONS AND MAX WINDS

INIT 10/0300Z 18.4N 111.9W 60 KT 70 MPH
12H 10/1200Z 19.1N 113.5W 65 KT 75 MPH
24H 11/0000Z 20.1N 116.1W 65 KT 75 MPH
36H 11/1200Z 20.8N 118.9W 55 KT 65 MPH
48H 12/0000Z 21.3N 121.7W 45 KT 50 MPH
60H 12/1200Z 21.6N 124.4W 40 KT 45 MPH
72H 13/0000Z 21.8N 127.0W 35 KT 40 MPH...POST-TROPICAL
96H 14/0000Z 22.2N 132.3W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 15/0000Z 22.5N 138.0W 25 KT 30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Blake

[Kingarabian]

I don't normally say this in regards to the NHC but wtf...? This is clearly a hurricane. A bunch of head scratchers by the best RSMC in the world so far in this young season.

[cycloneye]

Tropical Storm Cristina Discussion Number 15
NWS National Hurricane Center Miami FL EP052020
300 AM MDT Fri Jul 10 2020

Cristina has become better organized during the past several hours.
A curved band wraps almost completely around the center, and a
ragged eye has occasionally been apparent in satellite
images. The cyclone is beginning to look like a hurricane, but
there is still a large spread in the latest satellite intensity
estimates, ranging from 45 to 77 kt. In addition, a recent ASCAT
pass showed maximum winds of only 45 kt. Based on a compromise of
all of this data, the initial intensity remains 60 kt for this
advisory.

Cristina could still become a hurricane today while it remains over
waters warmer than 26 C and in low vertical wind shear conditions.
However, by tonight the storm will likely be moving over
progressively cooler waters and into a drier and more stable air
mass. The combination of these negative factors for the storm
should promote a steady weakening trend beginning tonight, and
ultimately Cristina is expected to become a post-tropical cyclone
in about 3 days. The NHC intensity forecast is largely an update
of the previous one, and in line with the consensus models IVCN and
HCCA.

The storm is moving west-northwestward at about 10 kt. There has
been no change to the track forecast reasoning. A mid-level ridge
centered over the southwestern U.S. should continue to steer
Cristina to the west-northwest during the next couple of days.
Beyond that time, when Cristina becomes a weak and shallow system, a
turn to the west is expected in the low-level flow. The track
models remain tightly clustered, and only minor changes were made
to the previous NHC forecast.


FORECAST POSITIONS AND MAX WINDS

INIT 10/0900Z 18.8N 113.0W 60 KT 70 MPH
12H 10/1800Z 19.7N 114.8W 65 KT 75 MPH
24H 11/0600Z 20.4N 117.5W 55 KT 65 MPH
36H 11/1800Z 20.9N 120.2W 50 KT 60 MPH
48H 12/0600Z 21.3N 122.8W 45 KT 50 MPH
60H 12/1800Z 21.6N 125.2W 40 KT 45 MPH
72H 13/0600Z 22.0N 127.7W 35 KT 40 MPH...POST-TROPICAL
96H 14/0600Z 22.5N 133.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 15/0600Z 23.0N 138.3W 25 KT 30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Cangialosi

[1900hurricane]

I actually don't hate the 60 kt intensity. Microwave estimates have been way down, and SATCON has been even below the NHC estimates. Convection is way shallower than it should be due to dry air, and eye patterns have been transient on IR. Even scatterometer data is less than I would expect of a 65 kt system at this point, although that may not mean too much.

[cycloneye]

Total dissapointment it did not reached hurricane status.

Tropical Storm Cristina Discussion Number 16
NWS National Hurricane Center Miami FL EP052020
900 AM MDT Fri Jul 10 2020

Cristina's appearance on satellite has not improved over the past
several hours. In fact, cloud tops are beginning to warm and some of
the convection has begun to erode over the northern portion of the
circulation. A blend of the satellite intensity estimates from TAFB
and SAB support keeping the initial intensity at 60 kt. However,
this may be a little generous due to the lower values suggested by
the objective satellite intensity estimates as well as an earlier
ASCAT pass showing maximum winds of only 45 kt.

It is becoming less likely that Cristina will become a hurricane as
the storm is forecast to cross the 26 C SST isotherm later today
and move into a drier and more stable air mass. Once the cyclone
enters this unfavorable environment a weakening trend should begin.
By 72 h, Cristina is expected to become a remnant low. The NHC
intensity forecast was adjusted slightly downward in the near term,
and no longer shows Cristina reaching hurricane strength. The
remainder of the intensity forecast is similar to the previous
official forecast.

The storm is moving west-northwestward at about 12 kt. A mid-level
ridge centered over the southwestern U.S. should continue to steer
Cristina to the west-northwest through tonight. As Cristina weakens
and becomes a shallow system, a gradual turn toward the west is
expected in the low-level flow. The track models remain tightly
clustered, and only minor changes were made to the previous NHC
forecast.

FORECAST POSITIONS AND MAX WINDS

INIT 10/1500Z 19.1N 114.2W 60 KT 70 MPH
12H 11/0000Z 19.8N 116.2W 60 KT 70 MPH
24H 11/1200Z 20.3N 118.9W 55 KT 65 MPH
36H 12/0000Z 20.6N 121.5W 50 KT 60 MPH
48H 12/1200Z 20.9N 124.0W 45 KT 50 MPH
60H 13/0000Z 21.2N 126.5W 40 KT 45 MPH
72H 13/1200Z 21.6N 128.9W 30 KT 35 MPH...POST-TROP/REMNT LOW
96H 14/1200Z 22.5N 134.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 15/1200Z 22.8N 139.1W 25 KT 30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Latto