EPAC: BLAS - Post-Tropical

[dexterlabio]

So which storm do you think will be the first Cat3 of the NHem this 2016? Will it be Blas, or Nepartak? Would be fun to turn this to a betting game.

[cycloneye]

Up to 70kts.

EP, 03, 2016070500, , BEST, 0, 139N, 1162W, 70, 989, HU

[Yellow Evan]

CDO looks better organized compared to 24 hours but cold cloud tops need to start wrapping around the center better.

[cycloneye]

HURRICANE BLAS DISCUSSION NUMBER 9
NWS NATIONAL HURRICANE CENTER MIAMI FL EP032016
800 PM PDT MON JUL 04 2016

Blas is gradually gaining strength. A ragged eye has been
occasionally evident in geostationary satellite images and the
inner core of the hurricane appears a little better organized than
it was earlier today. In fact, a recent SSMIS microwave overpass
showed an eye feature within the symmetric CDO. The latest
Dvorak classifications and ADT values from CIMSS at the University
of Wisconsin support raising the initial intensity to 75 kt.

The hurricane is expected to remain in conducive environmental
conditions for strengthening for another 36 hours as the wind shear
is expected to be less than 10 kt with sufficiently warm water and a
considerable amount of moisture. The official NHC intensity forecast
remains at the upper end of the guidance during that time and calls
for Blas to reach major hurricane status. In about two days,
however, the system is forecast to move over sea surface
temperatures of around 26 C and into a more stable air mass, which
should end the strengthening phase and promote a steady weakening
trend. Blas is expected to become a post-tropical cyclone by the
end of the period when it is forecast to be over sea surface
temperatures near 24 C.

Blas continues to move west-northwestward at about 12 kt on the
south side of a sprawling mid-level ridge over Mexico and the
eastern Pacific Ocean. The models are in very good agreement
in showing a continued west-northwestward motion during the next 3
to 4 days while the ridge remains the primary steering mechanism.
There is some divergence in the model solutions by the end of the
forecast period, with the GFS, GFDL, and UKMET models showing a more
northern track while the ECMWF and HWRF models have a track farther
south. This spread is associated with differences in how much Blas
interacts with a cut off low north of the Hawaiian Islands. The NHC
track forecast remains near the middle of the guidance envelope and
is very close to the multi-model consensus TVCE.

FORECAST POSITIONS AND MAX WINDS

INIT 05/0300Z 14.0N 116.8W 75 KT 85 MPH
12H 05/1200Z 14.4N 118.7W 85 KT 100 MPH
24H 06/0000Z 14.9N 121.1W 100 KT 115 MPH
36H 06/1200Z 15.3N 123.4W 105 KT 120 MPH
48H 07/0000Z 15.8N 125.4W 100 KT 115 MPH
72H 08/0000Z 17.1N 129.0W 80 KT 90 MPH
96H 09/0000Z 18.9N 132.2W 60 KT 70 MPH
120H 10/0000Z 20.7N 135.9W 40 KT 45 MPH...POST-TROPICAL

$$
Forecaster Cangialosi

[Yellow Evan]

Eye closed but the CDO looks ugly still.

[stormwise]

Better times ahead says the GFS18zCV @ a reasonable time frame 0-90hrs, This storm roars.

[cycloneye]

HURRICANE BLAS DISCUSSION NUMBER 10
NWS NATIONAL HURRICANE CENTER MIAMI FL EP032016
200 AM PDT TUE JUL 05 2016

Blas has continued to strengthen since the previous advisory. The
CDO has improved and the overall convective cloud pattern has
become more symmetrical. A ragged eye feature has been evident in
infrared imagery and is now completely surrounded by cloud tops
colder than -75C. Recent AMSU and ASCAT overpasses have helped
to place the center a little to the northeast of the positions noted
in conventional infrared imagery. The initial intensity has been
increased to 85 kt based on a blend of satellite intensity
estimates of T4.5/77 kt from TAFB and NHC objective intensities
ranging from T4.7-T5.0, and the continued improvement in the eye
pattern depicted in conventional and microwave satellite imagery.

Based primarily on microwave satellite fixes, Blas continues to move
west-northwestward or 285/12 kt. The hurricane is forecast to move
in a general west-northward direction throughout the forecast period
due to a strong deep-layer subtropical ridge remaining nearly
stationary to the north of Blas. The latest NHC global and regional
model guidance remains in excellent agreement on this stable
steering pattern, and the models are tightly packed around the
previous advisory track. Therefore, only minor tweaks were made, and
the new forecast track lies close to the consensus track model TVCE.

Blas has been rapidly strengthening over the past 24 hours, and an
additional 12 hours or so of significant strengthening is supported
by an expanding upper-level outflow pattern, low vertical wind shear
values decreasing to less than 5 kt by 12-24 hours, and a smaller
radius of maximum winds of about 15 nmi noted in recent ASCAT data.
Although vertical shear values are expected to remain low, by 36-48
hours Blas will be moving over SSTs near 26C and ocean heat content
values near zero, which should result in cooling of the ocean
beneath the hurricane and begin a slow weakening trend. By 72 hours
and beyond, Blas will be moving over even cooler water and into a
drier and more stable air mass, negative factors which should
combine to induce more significant weakening. The official intensity
forecast remains well above he consensus model IVCN and closely
follows the GFS-based LGEM statistical-dynamical intensity model,
which has thus far handled Blas' intensification trend the best.

FORECAST POSITIONS AND MAX WINDS

INIT 05/0900Z 14.2N 118.1W 85 KT 100 MPH
12H 05/1800Z 14.5N 119.9W 100 KT 115 MPH
24H 06/0600Z 15.0N 122.2W 110 KT 125 MPH
36H 06/1800Z 15.4N 124.2W 105 KT 120 MPH
48H 07/0600Z 16.0N 126.1W 95 KT 110 MPH
72H 08/0600Z 17.2N 129.8W 80 KT 90 MPH
96H 09/0600Z 19.1N 133.0W 60 KT 70 MPH
120H 10/0600Z 20.7N 136.4W 40 KT 45 MPH...POST-TROPICAL

$$
Forecaster Stewart

[Darvince]

Saved loop:

[Kingarabian]

5.0 from SAB.

[1900hurricane]

Looks to be trying to develop a larger eye. The transition between eyewall and outer bands is somewhat messy, which is likely holding Blas back.

[cycloneye]

New high peak is 120kts.

HURRICANE BLAS DISCUSSION NUMBER 11
NWS NATIONAL HURRICANE CENTER MIAMI FL EP032016
800 AM PDT TUE JUL 05 2016

Blas has been intensifying rapidly this morning. Satellite imagery
shows a ragged eye that has been warming and becoming better defined
in the middle of a large-sized central dense overcast (CDO). A
special Dvorak satellite classification from TAFB suggests that the
cyclone is close to major hurricane status, so the initial intensity
is boosted to 95 kt, and this could be conservative.

Blas has been moving nearly due westward since the last advisory,
with a longer-term initial motion estimate of 280/13. For about
the next 72 hours, the track model output is in good agreement that
Blas should be steered westward and then west-northwestward around
the southern and western periphery of a deep-layer ridge over the
subtropical eastern Pacific. After that time, there is a rather
significant divergence in the track guidance. The bulk of the model
solutions indicate a northwestward track when Blas interacts with
a cut-off low well northwest of it and encounters weaker ridging.
The ECMWF and its ensemble mean, however, predict a much more
southerly track in response to a stronger subtropical ridge. The
NHC forecast track is adjusted to the south of the previous one,
owing mostly to the more westerly initial motion. The track
forecast is closer to the ECMWF solution beyond day 3, based on the
premise that Blas should weaken significantly and become a shallow
cyclone during that time.

Given that Blas is undergoing rapid intensification, the short-term
forecast shows a significant increase in intensity within the next
12 to 24 hours and is above all of the numerical guidance. Later in
the period the hurricane should be moving over cooler waters, so a
gradual weakening trend is expected to commence in about 48 hours.
If Blas follows a more southern route than anticipated, however, it
could weaken more slowly than shown here.


FORECAST POSITIONS AND MAX WINDS

INIT 05/1500Z 14.1N 119.5W 95 KT 110 MPH
12H 06/0000Z 14.4N 121.5W 110 KT 125 MPH
24H 06/1200Z 14.8N 123.7W 120 KT 140 MPH
36H 07/0000Z 15.4N 125.5W 110 KT 125 MPH
48H 07/1200Z 16.0N 127.4W 95 KT 110 MPH
72H 08/1200Z 17.4N 130.9W 75 KT 85 MPH
96H 09/1200Z 19.1N 134.3W 45 KT 50 MPH
120H 10/1200Z 20.6N 137.7W 30 KT 35 MPH...POST-TROP/REMNT LOW

$$
Forecaster Kimberlain

[cycloneye]

 https://twitter.com/MJVentrice/status/750344399272443905

[Yellow Evan]

COD finally smoothing out. ADT numbers skyrocket and once the W becomes fully embedded on the western semicricle, this will be a Cat 4.

[Ntxw]

Yep raw adt shooting up. Major now probs, cat 4 likely to come at least.

[Yellow Evan]

2016JUL05 123000 4.6 980.3 79.6 4.6 4.6 6.4 MW ON OFF OFF -22.96 -72.28 EYE 9 IR 48.4 14.06 119.14 SPRL GOES15 24.6
2016JUL05 130000 4.6 980.3 79.6 4.6 4.6 6.5 MW ON OFF OFF -15.66 -72.41 EYE -99 IR 48.4 14.09 119.20 SPRL GOES15 24.6
2016JUL05 133000 4.7 978.3 82.2 4.7 5.8 6.3 MW AdjEnd OFF OFF -38.46 -72.45 EYE -99 IR 48.4 14.20 119.28 SPRL GOES15 24.6
2016JUL05 140000 4.9 974.4 87.4 4.9 5.8 6.7 1.3T/6hr OFF OFF -12.86 -72.90 EYE -99 IR 48.4 14.14 119.37 COMBO GOES15 24.5
2016JUL05 143000 5.2 968.7 94.8 5.2 5.8 6.7 1.3T/6hr OFF OFF -0.66 -72.52 EYE 17 IR 62.9 14.14 119.47 COMBO GOES15 24.4

[cycloneye]

I thought at least when Blas was a bonifide cane,this thread would be fairly active,but I understand is not the Atlantic.

 https://twitter.com/philklotzbach/status/750350694046011394

[Ntxw]

You can see the tail coming from that loop. Very good channel, as I mentioned it reminds me of Jimena last year and Marie the year before. Going to be a beautiful looking cane when fully mature.

[Darvince]

Plus, Blas isn't threatening any land as it is right now.

[Yellow Evan]

Code: Select all

             ----- Current Analysis -----
     Date :  05 JUL 2016    Time :   153000 UTC
      Lat :   14:15:27 N     Lon :  119:44:36 W

     
                CI# /Pressure/ Vmax
                5.4 / 964.9mb/ 99.6kt

     
             Final T#  Adj T#  Raw T#
                5.4     5.8     6.5

 Estimated radius of max. wind based on IR : 17 km

 Center Temp :  +7.3C    Cloud Region Temp : -70.4C

 Scene Type : EYE 

[JaxGator]

Pressure is getting lower.