EPAC: ANDRES - Post-Tropical

[Yellow Evan]

Credit to the NHC for making the vest out of a lose lose situation.

[cycloneye]

HURRICANE ANDRES DISCUSSION NUMBER 12
NWS NATIONAL HURRICANE CENTER MIAMI FL EP012015
800 PM PDT SAT MAY 30 2015

Andres has strengthened further today despite moderate northwesterly
shear. The cyclone had been maintaining a symmetric central dense
overcast (CDO), and the eye had slowly warmed until about 0000 UTC.
Over the past few hours though, the CDO has become more irregularly
shaped and the eye more indistinct. Dvorak T-numbers were 5.5/102 kt
at 0000 UTC from both agencies, and UW-CIMSS ADT values leveled off
at 5.7/107 kt. These data suggest that Andres may have been a major
hurricane at that time, but satellite data suggest that the cyclone
has since begun to weaken. The initial intensity is set at 95 kt,
slightly lower than 0000 UTC intensity estimates.

Andres is still moving generally northwestward in response to a
weakness in the subtropical ridge around 120w. Most of the track
guidance shows a high pressure ridge north of the cyclone
strengthening on Sunday which should cause the cyclone to turn
west-northwestward. Beyond 48 hours, the track models significantly
diverge, with the GFS-based guidance depicting a stronger cyclone
being steered northwestward over cool waters, followed by an
eastward turn. The ECMWF shows a weaker version of Andres eventually
turning westward, with its solution on the southern side of the
guidance envelope. The official NHC forecast is close to the multi-
model consensus (TVCE) through 36 hours. After that, the overly
strong GFS run is disregarded, resulting in a track forecast
relatively far left of TVCE.

The shear over Andres is forecast to decrease dramatically within
24 hours, but the cyclone will be moving over gradually cooler
waters and ingesting drier and more stable air during the next
couple of days. This competition between dynamic and thermodynamic
factors should result in a slow weakening through 48 hours. After
that time, even more unfavorable thermodynamic conditions could
result in a quicker rate of weakening, and Andres is expected to
become a remnant low by day 5. The NHC intensity forecast is
close to LGEM and somewhat lower than the multi-model consensus
ICON.

FORECAST POSITIONS AND MAX WINDS

INIT 31/0300Z 15.1N 116.8W 95 KT 110 MPH
12H 31/1200Z 15.6N 117.8W 95 KT 110 MPH
24H 01/0000Z 16.1N 119.1W 85 KT 100 MPH
36H 01/1200Z 16.5N 120.4W 75 KT 85 MPH
48H 02/0000Z 17.0N 122.0W 65 KT 75 MPH
72H 03/0000Z 18.4N 125.1W 50 KT 60 MPH
96H 04/0000Z 19.3N 128.2W 35 KT 40 MPH
120H 05/0000Z 19.3N 130.1W 25 KT 30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Kimberlain

[TropicalAnalystwx13]

Glad that NHC decided against upgrading.

[Yellow Evan]

Over the past few hours though, the CDO has become more irregularly
shaped and the eye more indistinct. Dvorak T-numbers were 5.5/102 kt
at 0000 UTC from both agencies, and UW-CIMSS ADT values leveled off
at 5.7/107 kt. These data suggest that Andres may have been a major
hurricane at that time, but satellite data suggest that the cyclone
has since begun to weaken. The initial intensity is set at 95 kt,
slightly lower than 0000 UTC intensity estimates.

Very interesting discussion.

[Yellow Evan]

Seems to really be getting chocked with it's horrible outflow to the NNW. Also is losing rainbands.

[Yellow Evan]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 31 MAY 2015 Time : 020000 UTC
Lat : 15:07:50 N Lon : 116:48:01 W


CI# /Pressure/ Vmax
5.7 / 954.8mb/107.2kt


Final T# Adj T# Raw T#
5.5 5.3 5.3

Center Temp : -55.3C Cloud Region Temp : -69.4C

Scene Type : EMBEDDED CENTER CLOUD REGION

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : EAST PACIFIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : ON
Rapid Dissipation Flag : OFF

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 107km
- Environmental MSLP : 1010mb

Satellite Name : GOES15
Satellite Viewing Angle : 27.5 degrees

[Yellow Evan]

Convection seems to be re-wrapping aorund the eye like it does every 3 hours.


UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 31 MAY 2015 Time : 023000 UTC
Lat : 14:25:44 N Lon : 116:30:00 W


CI# /Pressure/ Vmax
5.7 / 955.1mb/107.2kt


Final T# Adj T# Raw T#
5.5 5.5 5.5

Center Temp : -69.8C Cloud Region Temp : -70.8C

Scene Type : EMBEDDED CENTER CLOUD REGION

Positioning Method : SPIRAL ANALYSIS

Ocean Basin : EAST PACIFIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : ON
Rapid Dissipation Flag : OFF

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 107km
- Environmental MSLP : 1010mb

Satellite Name : GOES15
Satellite Viewing Angle : 27.2 degrees

[Yellow Evan]

CIMSS TROPICAL CYCLONE INTENSITY CONSENSUS FOR ANDRES (01E) 2015
CURRENT ESTIMATE
Date (mmddhhmm): 05310048
SATCON: MSLP = 953 hPa MSW = 108 knots
SATCON Member Consensus: 104.0 knots
Pressure -> Wind Using SATCON MSLP: 108 knots
Distance to Outer Closed Isobar Used is 200 nm
Eye Size Correction Used is 1.5 knots Source: MW

Member Estimates

ADT: 955 hPa 107 knots Scene: CDO Date: MAY310130
CIMSS AMSU: 951 hPa 102 knots Bias Corr: 0 (MW) Date: 05310048
SSMIS: 941 hPa 105 knots Date: 05301430
CIRA AMSU: NA hPa NA knots Tmax: NA


Bit of a spread but all agree on a triple digit intensity storm.

Based on this, I'd agree with an 100 knt intensity at 0z.

[CrazyC83]

I'm thinking if it was a major, 1800Z or 2100Z is more likely when it was. But I am still not too sure if it ever got there...

[Yellow Evan]

I'm thinking if it was a major, 1800Z or 2100Z is more likely when it was. But I am still not too sure if it ever got there...

Understandable, but the evidence clearly supports it was one at 0z.

[cycloneye]

I'm thinking if it was a major, 1800Z or 2100Z is more likely when it was. But I am still not too sure if it ever got there...

They may go back at post season analysis.

[Yellow Evan]

Cloud tops seem to be cooling again. Now the question is will it sustain itself so we can get another T5.5?

[Yellow Evan]

Center fix off



UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 31 MAY 2015 Time : 030000 UTC
Lat : 14:15:00 N Lon : 116:32:27 W


CI# /Pressure/ Vmax
5.7 / 955.2mb/107.2kt


Final T# Adj T# Raw T#
5.5 5.4 5.4

Center Temp : -66.8C Cloud Region Temp : -69.9C

Scene Type : EMBEDDED CENTER CLOUD REGION

Positioning Method : SPIRAL ANALYSIS

Ocean Basin : EAST PACIFIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : ON
Rapid Dissipation Flag : FLAG

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 107km
- Environmental MSLP : 1010mb

Satellite Name : GOES15
Satellite Viewing Angle : 27.1 degrees

[xtyphooncyclonex]

Oh NHC I just woke up and dissapointed to see 95 kts

[HurricaneTracker2031]

Andres is really on verge of cat 3 but won't be officially called today. NHC acknowledge that it may have been a major hurricane for a brief period before it started weakening prior to advisory. The area behind it, 93E, should be taking of NW and strengthening after Andres passes off.





Synopsis on Andres and other system: http://goo.gl/B0GqBw

Personal Forecast Disclaimer:
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.

[Yellow Evan]

Oh NHC I just woke up and dissapointed to see 95 kts

It doesn't look anything more than 75-90 knts. It def was 100 at some point.

[Yellow Evan]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 31 MAY 2015 Time : 033000 UTC
Lat : 15:10:20 N Lon : 116:47:30 W


CI# /Pressure/ Vmax
5.7 / 954.8mb/107.2kt


Final T# Adj T# Raw T#
5.4 5.2 5.2

Center Temp : -62.8C Cloud Region Temp : -73.0C

Scene Type : UNIFORM CDO CLOUD REGION

Positioning Method : SPIRAL ANALYSIS

Ocean Basin : EAST PACIFIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : ON
Rapid Dissipation Flag : FLAG

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 107km
- Environmental MSLP : 1010mb

Satellite Name : GOES15
Satellite Viewing Angle : 27.5 degrees

[Yellow Evan]

Cloud tops cooling, but dry air killing it and eye is so cloudy.

Lol.

UW-CIMSS Automated Satellite-Based
Advanced Dvorak Technique (ADT)
Version 8.2.1
Tropical Cyclone Intensity Estimation Algorithm


Current Intensity Analysis




UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 31 MAY 2015 Time : 050000 UTC
Lat : 15:08:48 N Lon : 116:56:08 W


CI# /Pressure/ Vmax
5.7 / 954.8mb/107.2kt


Final T# Adj T# Raw T#
5.4 5.8 6.6

Estimated radius of max. wind based on IR :<10 km

Center Temp : -25.4C Cloud Region Temp : -73.1C

Scene Type : PINHOLE EYE

Positioning Method : SPIRAL ANALYSIS

Ocean Basin : EAST PACIFIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : 0.5T/hour
Weakening Flag : ON
Rapid Dissipation Flag : OFF

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 107km
- Environmental MSLP : 1010mb

Satellite Name : GOES15
Satellite Viewing Angle : 27.3 degrees

[cycloneye]

HURRICANE ANDRES DISCUSSION NUMBER 13
NWS NATIONAL HURRICANE CENTER MIAMI FL EP012015
200 AM PDT SUN MAY 31 2015

Andres appears to have peaked in intensity during the early evening
hours. Since that time, the eye has become obscured in infrared
satellite imagery and the cloud pattern has become somewhat less
symmetric. Dvorak data T-numbers from both SAB and TAFB have
decreased, and based on recent satellite trends the initial
intensity has been lowered to 90 kt.

The initial motion estimate is northwest or 305 degrees at 6 kt.
Andres is forecast to turn west-northwestward today as a mid-level
ridge to the north of the hurricane strengthens. A west-
northwestward motion should then continue during the next couple of
days. By 72 hours, a deepening mid-latitude trough is forecast to
approach the west coast of the United States. The dynamical models
that maintain a stronger tropical cyclone, turn Andres northward and
northeastward ahead of the trough. The GFDL and ECMWF which depict
a weaker Andres, show a continued west-northwestward track in the
low- to mid-level easterly flow. The NHC forecast continues to lean
toward the latter solution, but shows a slower forward motion at
days 4 and 5 than the previous advisory.

Although moderate west-northwesterly shear that is currently
over Andres is forecast to decrease during the next 24 hours, the
hurricane will be moving over cool water which should cause a
gradual reduction in intensity. A faster rate of weakening is
expected to begin in 36 to 48 hours after the cyclone moves over
waters less than 26C and into a drier and more stable environment.


FORECAST POSITIONS AND MAX WINDS

INIT 31/0900Z 15.4N 117.4W 90 KT 105 MPH
12H 31/1800Z 15.8N 118.3W 85 KT 100 MPH
24H 01/0600Z 16.3N 119.6W 75 KT 85 MPH
36H 01/1800Z 16.8N 120.9W 65 KT 75 MPH
48H 02/0600Z 17.5N 122.5W 55 KT 65 MPH
72H 03/0600Z 19.0N 125.6W 40 KT 45 MPH
96H 04/0600Z 19.5N 127.0W 30 KT 35 MPH
120H 05/0600Z 19.5N 128.0W 25 KT 30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Brown

[Kingarabian]