EPAC: CRISTINA - Post-Tropical

[Kingarabian]

.CRISTINA STRENGTHENS INTO A HURRICANE...

[Kingarabian]

HURRICANE CRISTINA DISCUSSION NUMBER 7
NWS NATIONAL HURRICANE CENTER MIAMI FL EP032014
200 AM PDT WED JUN 11 2014

Cristina continues to intensify. The cyclone consists of a small
central dense overcast in geostationary satellite imagery with
cold-topped convection to -80C in the northern semicircle. There
have been faint hints of eye or warm spot during the past several
hours, and a 0329 UTC TRMM overpass showed a closed low- to mid-
level ring of convection surrounding the center. Satellite
classifications from TAFB and SAB supported an intensity of 60 kt at
synoptic time. However, the initial intensity estimate is increased
to 65 kt, based on UW-CIMSS ADT values now to 4.5/77 kt and the
persistence of an eye feature that has warmed slightly and become
better defined.

The cyclone has been moving south of due west in response to a
strong mid-level ridge over northwestern Mexico, but the heading
appears to have recently become more westerly. The ridge is
forecast to either remain in place or shift slightly eastward during
the next few days, which should cause the track of Cristina to
gradually bend west-northwestward. The track guidance is in
generally good agreement on this scenario, but small differences
in the location of the ridge over Mexico lead to slightly different
motion headings. The ECMWF maintains the center of the ridge a bit
to the west of the GFS and other models, resulting in a solution on
the southern side of the guidance envelope. The NHC track forecast
is adjusted a hair to the left of the previous one in the direction
of the ECMWF, which has continued to correctly forecast a more
southern track.

The environment in which Cristina is embedded remains ideal for
intensification. The cyclone is located underneath a mid- to upper-
level ridge axis and over very warm waters. The inner core
structure has also become better defined, with the closed ring
seen in microwave imagery signaling that rapid intensification is
a possibility. The NHC forecast is adjusted upward in the short
term based on current trends, and thee is some potential for
Cristina to become stronger than forecast. In about 60 hours,
Cristina should encounter increasing southwesterly shear associated
with an upper-level trough extending southwestward from California
coast and should reach markedly cooler waters in about 4 days. This
should result in a pronounced weakening trend at the end of the
forecast period and perhaps a quick demise. The NHC intensity
forecast is close to the multi-model consensus through 72 hours and
near the LGEM after that time.


FORECAST POSITIONS AND MAX WINDS

INIT 11/0900Z 15.2N 104.1W 65 KT 75 MPH
12H 11/1800Z 15.3N 105.2W 75 KT 85 MPH
24H 12/0600Z 15.7N 106.6W 80 KT 90 MPH
36H 12/1800Z 16.4N 108.0W 85 KT 100 MPH
48H 13/0600Z 17.2N 109.4W 85 KT 100 MPH
72H 14/0600Z 18.6N 111.8W 70 KT 80 MPH
96H 15/0600Z 19.2N 113.5W 55 KT 65 MPH
120H 16/0600Z 19.6N 114.7W 35 KT 40 MPH

$$
Forecaster Kimberlain

Forecasted to be a category 2 hurricane now.

[hurricanes1234]

Aww, it looks so cute on satellite imagery. A very tiny little hurricane indeed!

[Kingarabian]

One of the ugliest Hurricanes I've seen in quite some time. Right up there with all the ugly Atlantic storms.

Hopefully she goes annular. Now those things are a beauty.

[Yellow Evan]

Appears to still be deepening. ATCF should be out soon.

[cycloneye]

HURRICANE CRISTINA DISCUSSION NUMBER 8
NWS NATIONAL HURRICANE CENTER MIAMI FL EP032014
800 AM PDT WED JUN 11 2014

After an overnight period of strengthening, conventional and
microwave satellite imagery suggest that Cristina's intensity has
leveled off. Recent SSMI/S and TRMM overpasses indicated a low-
level eye feature, but the mid-level eye is no longer evident. The
cyclone again appears to have ingested dry mid-level air, which has
eroded the convection in the western semicircle. The initial
intensity of 65 kt is based on consensus Dvorak satellite intensity
estimates of T4.0/65 kt from TAFB and SAB.

After a brief jog to the west-southwest, Cristina appears to have
resumed a westerly motion of 275/05 kt. Other than to make just a
tad right-of-track adjustment due to the initial position, the NHC
official forecast track is just an update of the previous advisory
track. Cristina is expected to move westward today, followed by a
west-northwestward motion around the southwestern periphery of a
deep-layer ridge in the 24- to 72-hour period, a scenario which
most of the reliable models strongly agree on. After that, however,
the models diverge significantly with the GFS, GFS Ensemble, NAVGEM,
HWRF, and GFDL models taking a stronger Cristina more northward,
whereas the ECMWF and UKMET weaken the cyclone fairly quickly and
move it more westward. Given that the official intensity forecast is
calling for a weaker and smaller tropical cyclone by 96 and 120
hours, the official forecast at those times is roughly an average of
the ECMWF and GFS models, which shows a weaker and more vertically
shallow cyclone moving west-northward to westward.

Cristina has consistently been intensifying at night during the
convective maximum period, which seems likely to continue for
another 24-48 hours. However, the cyclone will still be battling
occasional intrusions of dry mid-level air for the remainder of the
forecast period, especially after 72 hours, so only gradual
intensification is expected. After day 3, increasing southwesterly
vertical wind shear and SSTs cooler than 26C are expected to induce
steady weakening. The NHC intensity forecast is similar to the
previous advisory, and closely follows the consensus intensity
model ICON.

FORECAST POSITIONS AND MAX WINDS

INIT 11/1500Z 15.4N 104.8W 65 KT 75 MPH
12H 12/0000Z 15.7N 105.9W 70 KT 80 MPH
24H 12/1200Z 16.2N 107.3W 75 KT 85 MPH
36H 13/0000Z 16.9N 108.6W 80 KT 90 MPH
48H 13/1200Z 17.7N 110.0W 75 KT 85 MPH
72H 14/1200Z 19.0N 112.3W 60 KT 70 MPH
96H 15/1200Z 19.5N 113.8W 45 KT 50 MPH
120H 16/1200Z 19.9N 115.1W 30 KT 35 MPH

$$
Forecaster Stewart

[TropicalAnalystwx13]

Latest microwave pass.

[hurricanes1234]

It's still having issues with dry air. If it does not fend off that dry air soon enough, it probably will not attain Category 2 status, which is what I see happening, and what the forecast calls for. I'd estimate a peak around 75 knots. Also, it does not look that good on IR imagery either. I wouldn't be surprised if it is still 65 knots by the next advisory, as long as it continues to ingest dry air, it will not strengthen properly.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[TropicalAnalystwx13]

Saved loop

Cristina seems to have gotten into the habit of intensifying during the afternoon hours, which is actually interesting considering that diurnal maximum (when instability is at its greatest) occurs in the pre-dawn hours. While its infrared appearance has some catching up to do, Cristina's visible appearance is improving again, with a distinct eye and improvement in spiral banding in all four quadrants.

Dry air hasn't been hampering development of the system, it's just been slowing it (halting rapid intensification). That said, RI is still a possibility if it can mix the current dry air out of its core. Cristina still has about 36 hours to intensify.

[cycloneye]

EP, 03, 2014061118, , BEST, 0, 155N, 1050W, 70, 986, HU

[Yellow Evan]

Looks much better now.

[hurricanes1234]

Looks much better now.

Agreed, convection is firing around the center. It's really strange this only strengthens during diurnal minimum.

[Yellow Evan]

Looks much better now.

Agreed, convection is firing around the center. It's really strange this only strengthens when the Sun is not up.

The sun is up now and it's deepening. These kinds storms that are near dry air can be fickle. Not that a storm can't RI despite dry air (thought it's not exactly likely). Look at Adrian 11, which inherited a dry slot right before bombing out.

[cycloneye]

HURRICANE CRISTINA DISCUSSION NUMBER 9
NWS NATIONAL HURRICANE CENTER MIAMI FL EP032014
200 PM PDT WED JUN 11 2014

An intermittent eye feature has been noted in both conventional and
microwave satellite imagery today, and Dvorak intensity estimates
have steadily increased as a result. However, a 1653 UTC AMSU pass
indicated that the 15-20 nmi diameter eyewall was open to the east
and that it was completely detached from any convective bands,
suggesting that the hurricane is probably not quite as strong as the
T4.5 satellite intensity estimates from TAFB and SAB are indicating.
Therefore, the initial intensity estimate is set to 70 kt.

Cristina is now moving at a fairly steady motion of 280/05 kt. The
model guidance remains consistent on the hurricane moving westward
through tonight, followed by a west-northwestward motion beginning
on Thursday and continuing through 72 hours. After that, a
weakening Cristina is forecast to turn more westward as the cyclone
gradually becomes more vertically shallow as it encounters
unfavorable atmospheric and oceanic conditions, and gets steered
by the low-level easterly flow on the south side of broad ridge of
high pressure. Although the new model tracks still diverge
significantly at Days 4 and 5, the GFS and GFS-Ensemble models have
nudged their tracks a little farther west and closer to the
previous NHC forecast. As a result, the official forecast track is
similar to the previous one, and remains a little to the left of the
consensus model TCVE due to the right-bias of the GFDL-member.

Intermittent intrusions of dry mid-level air should continue to
interrupt the development of persistent eyewall convection for the
next 36 hours or so. However, given that Cristina will still be over
near 29C SSTs and in an extremely low shear environment, those
conditions should allow for at least gradual strengthening during
that time. Around 72 hours or so, environmental and oceanic
conditions are expected to become increasingly unfavorable, which
should combine to produce steady weakening, especially by 96 hours
and beyond.

FORECAST POSITIONS AND MAX WINDS

INIT 11/2100Z 15.6N 105.2W 70 KT 80 MPH
12H 12/0600Z 16.0N 106.4W 75 KT 85 MPH
24H 12/1800Z 16.6N 107.8W 80 KT 90 MPH
36H 13/0600Z 17.3N 109.2W 85 KT 100 MPH
48H 13/1800Z 18.1N 110.5W 75 KT 85 MPH
72H 14/1800Z 19.1N 112.4W 60 KT 70 MPH
96H 15/1800Z 19.5N 113.9W 45 KT 50 MPH
120H 16/1800Z 19.9N 115.3W 30 KT 35 MPH

$$
Forecaster Stewart

[hurricanes1234]

Unfortunately for Cristina, it likely won't be able to make full use of the warm water and extremely low shear environment due to persistent dry air. Is there any chance at all that the dry air will let up or moisten a little?

[hurricaneCW]

She's looking really good now, there's less dry air mixing in now and the core is becoming better established. I think there's an outside chance for her to become a 120 mph Category 3 before she fully weakens. It's a small and pretty looking storm too.

[Yellow Evan]

[Kingarabian]

http://www.nrlmry.navy.mil/htdocs_dyn_pregen_sat/PUBLIC/tc_pages/thumbs/medium/tc14/EPAC/03E.CRISTINA/amsr2/89h/1degreeticks/20140611.1841.GCOMW1.x.89h_1deg.03ECRISTINA.70kts-986mb-155N-1050W.69pc.jpgg]

Looking great!

[TropicalAnalystwx13]

Now that the dry air has been mixed out of Cristina's circulation, and assuming no more is entrained, the storm will need to be monitored for rapid intensification over the next 24 hours. The fact that Cristina is very compact and has an organized core increases its chances of exceeding current predictions.

I'd assess the current intensity at 80kt based on T4.6/79.6kt from UW-CIMSS ADT and the fact that Cristina has continued to organize since SAB/TAFB assigned T4.5/77kt.

[hurricanes1234]

It's getting there for sure. Could this finally be the last push needed for rapid intensification? We shall see over the coming advisories.