EPAC: AMANDA - Post-Tropical

[Yellow Evan]

I'd say 45 knts is a little generous. I think they will go with 40 knts as well

[cycloneye]

TROPICAL STORM AMANDA DISCUSSION NUMBER 26
NWS NATIONAL HURRICANE CENTER MIAMI FL EP012014
800 PM PDT WED MAY 28 2014

The cloud tops of Amanda have been warming during the past few
hours with almost no deep convection near the center. Although a
well-defined mid-level center is apparent on the latest satellite
imagery, this feature is well to the northeast of the low-level
circulation as indicated by ASCAT data and a recent SSMI/S pass.
Based on the current satellite trends, the initial intensity is
lowered to 40 kt, a bit below the recent Dvorak estimates.

The microwave data show that Amanda is moving to the northeast at a
little slower pace of about 5 kt. This motion should continue on
Thursday ahead of a mid-level trough. This trough is expected to
moving away from Amanda by Friday, which would leave the storm in
light steering currents. After that time, the weakened storm will
probably turn to the west and west-southwest as a low- to mid-level
ridge builds over the eastern Pacific. There have not been any
significant changes to the guidance, and the latest NHC forecast is
very close to the previous one.

Amanda should continue to weaken for the next couple of days due to
moderate shear, dry air aloft and marginal SSTs. While the shear is
forecast to weaken some in a day or so, the storm will likely have
entrained a significant amount of dry air by then, and it probably
won't be able to take advantage of the decreased shear. The cyclone
should become a remnant low in a couple of days due to these
marginal environment conditions. Most of the guidance shows steady
weakening and the official NHC prediction follows suit, at or below
the intensity consensus throughout the period.


FORECAST POSITIONS AND MAX WINDS

INIT 29/0300Z 16.3N 111.3W 40 KT 45 MPH
12H 29/1200Z 16.7N 110.7W 35 KT 40 MPH
24H 30/0000Z 17.2N 109.7W 30 KT 35 MPH
36H 30/1200Z 17.5N 109.0W 25 KT 30 MPH
48H 31/0000Z 17.6N 109.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 01/0000Z 17.3N 110.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 02/0000Z 16.5N 111.5W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 03/0000Z...DISSIPATED

$$
Forecaster Blake

[TropicalAnalystwx13]

Just as a review...

- On May 24, Amanda became a Category 1 hurricane, one of seven to occur in the East Pacific on or before that date
- In the 24 hour period between 8am PDT May 24 and May 25, maximum sustained winds increased from 75 mph to 155 mph and the pressure dropped from 989 millibars to 932 millibars. This is the 3rd fastest rate of rapid deepening observed in the Pacific
- At 2am PDT on May 25, Amanda attained Category 4 intensity, the earliest instance on record.
- At 8am PDT on May 25, Amanda attained its aforementioned peak of 155 mph and 932 millibars, surpassing 2001's Adolph as the strongest May tropical cyclone on record in the East Pacific.
- Between 8am PDT May 23 and 8pm PDT May 28, Amanda has accumulated 18.455 units of Accumulated Cyclone Energy (ACE), making it the highest ACE-producing cyclone ever observed in the East Pacific during the month of May. Amanda also pushes the ACE value to the highest ever observed overall in the month of May.
- If Amanda is upgraded to a Category 5 hurricane in post-season analysis (not particularly likely?), it would be the earliest Category 5 system ever observed in the basin.

Pretty successful storm I'd say.

[Yellow Evan]

On a sad note, Amanda has killed 3 people.

[hurricanes1234]

On a sad note, Amanda has killed 3 people.

But how? It didn't make landfall.

[cycloneye]

TROPICAL STORM AMANDA DISCUSSION NUMBER 27
NWS NATIONAL HURRICANE CENTER MIAMI FL EP012014
200 AM PDT THU MAY 29 2014

Amanda has come unglued during the past few hours, with the
remaining deep convection now located more than 2 degrees to the
northeast of the low-level center. This weakening appears to be due
to the usually potent combination of vertical wind shear and mid/
upper-level dry air advecting over the cyclone. The initial
intensity is decreased to 35 kt based on the degradation in the
satellite presentation and is a blend of the latest Dvorak Final-T
and CI numbers from TAFB and SAB.

While the SHIPS model shows the shear decreasing over Amanda during
the next day or two, the thermodynamic environment continues to
worsen. Therefore, it seems unlikely that Amanda will be able to
restrengthen. The NHC forecast continues to show a weakening trend
and is close to the intensity consensus. Remnant low status is
forecast in 36 hours, although this could occur sooner, with
dissipation expected in 4 or 5 days.

Recent microwave imagery and multi-channel IR imagery suggest that
the low-level center is exposed to the southwest of the remaining
convection and that the center may be elongating. The initial motion
estimate is a rather uncertain 045/05, but it does appear that
Amanda has been moving a little to the left of the previous forecast
track. The bulk of the dynamical guidance shows Amanda turning
toward the east-northeast and slowing down later today as an
upper-level trough passes by to the north. By Friday, the guidance
suggests a slow eastward motion, followed by a westward turn in 72
hours as Amanda becomes a shallow cyclone and is steered more by
the low-level flow. The new NHC track is a blend of the previous
forecast adjusted for the initial position and motion and the latest
guidance, and lies north of a blend of the GFS and ECMWF.

FORECAST POSITIONS AND MAX WINDS

INIT 29/0900Z 16.8N 110.9W 35 KT 40 MPH
12H 29/1800Z 17.1N 110.1W 30 KT 35 MPH
24H 30/0600Z 17.4N 109.5W 25 KT 30 MPH
36H 30/1800Z 17.5N 109.1W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 31/0600Z 17.5N 108.9W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 01/0600Z 17.3N 109.7W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 02/0600Z 17.0N 110.5W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 03/0600Z...DISSIPATED

$$
Forecaster Brennan

[Yellow Evan]

On a sad note, Amanda has killed 3 people.

But how? It didn't make landfall.

Via outer rianbands and waves.

[cycloneye]

For the record.


TROPICAL DEPRESSION AMANDA DISCUSSION NUMBER 28
NWS NATIONAL HURRICANE CENTER MIAMI FL EP012014
800 AM PDT THU MAY 29 2014

The satellite presentation of Amanda has been deteriorating during
the last several hours. The remaining deep convection is confined
to a band that is about 150 n mi from the center, and even that
feature lacks curvature. Dvorak classifications continue to
decrease, and on that basis, Amanda is downgraded to a tropical
depression with an initial intensity of 30 kt. Continued weakening
is forecast, and Amanda will likely become a remnant low in about a
day or sooner. Dissipation is predicted to occur in about 4 days,
following the GFS and ECMWF models.

The low-level center of Amanda had been difficult to find
overnight, but recent microwave and visible images indicate that it
is located to the south of the previous estimate. In addition, the
center itself has become increasingly elongated and diffuse. The
depression, or its remnant low, is expected to move eastward or
east-northeastward at a decreasing pace for the next 24 to 36 hours.
Beyond that time, whatever is left of Amanda should turn
southwestward when it is steered by a building low- to mid-level
ridge to its north. The NHC track forecast has been adjusted
southward mainly to account for the adjusted initial position.

FORECAST POSITIONS AND MAX WINDS

INIT 29/1500Z 16.3N 110.0W 30 KT 35 MPH
12H 30/0000Z 16.5N 109.2W 25 KT 30 MPH
24H 30/1200Z 16.6N 108.7W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 31/0000Z 16.6N 108.5W 20 KT 25 MPH...POST-TROP/REMNT LOW
48H 31/1200Z 16.7N 108.6W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 01/1200Z 16.1N 109.5W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 02/1200Z...DISSIPATED

$$
Forecaster Cangialosi

[RL3AO]

Couldn't quite get to 20 ACE which would have been very impressive.

[cycloneye]

Is over but made new records and got plenty of ACE units.

POST-TROPICAL CYCLONE AMANDA DISCUSSION NUMBER 29
NWS NATIONAL HURRICANE CENTER MIAMI FL EP012014
200 PM PDT THU MAY 29 2014

Satellite images indicate that the low-level center of Amanda has
become diffuse and could be opening up into a trough. In addition,
organized deep convection has been absent near the center of
circulation for most of the day. Therefore, Amanda is now declared
a remnant low, and this is the last advisory on this system issued
by the National Hurricane Center.

The remnant low is moving eastward at about 7 kt. The weak cyclone
is expected to slow down and become nearly stationary on Thursday,
before turning southwestward on Friday. Dissipation is expected to
occur in 3 to 4 days, following the guidance of the GFS and ECMWF
models.

For additional information on the remnant low please see High
Seas Forecasts issued by the National Weather Service, under
AWIPS header NFDHSFEPI and WMO header FZPN01 KWBC.



FORECAST POSITIONS AND MAX WINDS

INIT 29/2100Z 16.2N 109.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
12H 30/0600Z 16.5N 108.3W 25 KT 30 MPH...POST-TROP/REMNT LOW
24H 30/1800Z 16.8N 108.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
36H 31/0600Z 16.8N 108.3W 20 KT 25 MPH...POST-TROP/REMNT LOW
48H 31/1800Z 16.7N 108.6W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 01/1800Z 16.0N 109.9W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 02/1800Z...DISSIPATED

$$
Forecaster Cangialosi

[Cyclenall]

On a sad note, Amanda has killed 3 people.

Are they sure those deaths are directly from the hurricane? Seems pretty far away for that.

[hurricanes1234]

Au revoir, Amanda!

[Yellow Evan]

On a sad note, Amanda has killed 3 people.

Are they sure those deaths are directly from the hurricane? Seems pretty far away for that.

AFAIK yes. Also worth noting that Cosme 13 did kill 3 remaining a similar distance away form MX.

[SeGaBob]

Well this was a fun system to watch for sure. I would think that there will be more storms like this with the El Nino this year.

Edit: I became a category 1 with this post.

[galaxy401]

Interesting storm she was. Could be an impending sign of what this season may bring.

[xtyphooncyclonex]

It was a very impressive, powerful, interesting storm, which made the ACE of the EPac over 800%. This is also record-breaking and historic. This formed also unusually early and it rapidly intensified. We all never expected this, as we all thought it was nearly impossible but it happened!

[hurricanes1234]

Really looking forward to the post-tropical analysis of Amanda. Does anyone think, even if it's ever so slightly, that it could be upgraded to a Category 5 after being analyzed?

[xtyphooncyclonex]

Really looking forward to the post-tropical analysis of Amanda. Does anyone think, even if it's ever so slightly, that it could be upgraded to a Category 5 after being analyzed?

Yes, it is highly possible. Amanda is tied for having the 3rd fastest intensification, tied with Elida 2002. Elida 2002 first had a peak intensity slightly below the category 4 threshold. Due to Dvorak analysis, Elida 2002 was upgraded to a category 5 hurricane. Amanda should be upgraded, due to Dvorak estimates at 7.0, which means a category 5 hurricane could be supported. If it gets upgraded, it would still be the strongest May hurricane on record, and it would become the first CATEGORY FIVE EVER TO FORM IN MAY IN THE EPAC and the EARLIEST CATEGORY FIVE to form in the basin.

[CrazyC83]

I'm on the fence for an upgrade. There were some 7.0's but they didn't seem unanimous. I'd keep it at 135 kt personally, but that is just me.