E Pacific Tropical Action of 2014

[Yellow Evan]

The Gulf of Tehuantepec gale event should subside on Sunday. As we witnessed following the last gale event, TC genesis increased as dual areas of broad low pressure consolidated from the monsoonal trough and headed N to NE. This time the Euro is a bit more aggressive with genesis and is suggesting a formidable TC near the SW Coast of Mexico as a Western trough develops. 

 

Last run they brought it to 956 mbar. GFS shows a weak but long-lived TS in the 18z run.

[Yellow Evan]

Invest'd and up to 30%/50%.

[phil882]

The GFS has now come around to the ECMWF idea (not surprising) by failing to develop the further west disturbance due to dry air intrusion, instead focusing on the newer cluster of convection hanging back at 95W. The ECMWF meanwhile has dropped everything, and that's looking like an increasingly likely solution given the subsiding phase of the MJO (looking at velocity potential) is moving overhead in the EPAC. The GFS has thus far been too aggressive with genesis even in more favorable intraseasonal signals, so I'd be a little weary of the model now that we appear to be (temporarily) moving in a pattern more conducive to suppressed convection in the EPAC. 

 

http://www.atmos.albany.edu/student/ventrice/real_time/maps/mjo/global_analyses.html

[Yellow Evan]

The GFS has now come around to the ECMWF idea (not surprising) by failing to develop the further west disturbance due to dry air intrusion, instead focusing on the newer cluster of convection hanging back at 95W. The ECMWF meanwhile has dropped everything, and that's looking like an increasingly likely solution given the subsiding phase of the MJO (looking at velocity potential) is moving overhead in the EPAC. The GFS has thus far been too aggressive with genesis even in more favorable intraseasonal signals, so I'd be a little weary of the model now that we appear to be (temporarily) moving in a pattern more conducive to suppressed convection in the EPAC. 

 

http://www.atmos.albany.edu/student/ventrice/real_time/maps/mjo/global_analyses.html

 

Down to 40/50%. Could we have to wait even longer for Amanda?

[Ed Lizard]

It is only 2 days into the season...

[Yellow Evan]

It is only 2 days into the season...

 

Well, we already had a 50% bust and we could have a 60% bust from the first two invests.

[icebreaker5221]

The GFS has now come around to the ECMWF idea (not surprising) by failing to develop the further west disturbance due to dry air intrusion, instead focusing on the newer cluster of convection hanging back at 95W. The ECMWF meanwhile has dropped everything, and that's looking like an increasingly likely solution given the subsiding phase of the MJO (looking at velocity potential) is moving overhead in the EPAC. The GFS has thus far been too aggressive with genesis even in more favorable intraseasonal signals, so I'd be a little weary of the model now that we appear to be (temporarily) moving in a pattern more conducive to suppressed convection in the EPAC. 

 

http://www.atmos.albany.edu/student/ventrice/real_time/maps/mjo/global_analyses.html

 

Not surprising what the GFS has been doing in terms of genesis given that it's been too slow in propagating the MJO.  Early on, GFS kept the most favorable region too far west and the first wave developed.  Now GFS has the MJO is getting stuck a bit further east, keeping the upper-levels favorable to develop wave 2.  I wouldn't be surprised if tomorrow's GFS has the most favorable VP too far east to develop either.

[Yellow Evan]

Not surprising what the GFS has been doing in terms of genesis given that it's been too slow in propagating the MJO.  Early on, GFS kept the most favorable region too far west and the first wave developed.  Now GFS has the MJO is getting stuck a bit further east, keeping the upper-levels favorable to develop wave 2.  I wouldn't be surprised if tomorrow's GFS has the most favorable VP too far east to develop either.

 

Still has the phantom system behind 91E passing well out at sea, I guess you were right. 91E itself is 20%/20%. Yet the JTWC hast it at high prob and a TCFA. This is strange.

 

Edit: It's at 0/0 now.

[Yellow Evan]

Well, from that fantasy GFS system, we have 92E at 10%/30%.

[phil882]

Looks like 92E is a good candidate for the first storm of the year. Both the GFS and ECMWF are biting, and the track looks rather interesting, as the system will be stuck between a mid-level ridge and trough and probably not be going anywhere anytime soon for the next week as long as it survives. Interestingly the GFS has a more negative outlook over the next five days, suggesting vertical wind shear will take its toll beyond 48 hours and lead to 92E's demise as it slides under the mid-level trough further west. 

 

[Ground Scouring]

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
1100 AM PDT THU MAY 22 2014

For the eastern North Pacific...east of 140 degrees west longitude:

1. Visible satellite images indicate that showers and thunderstorms are
becoming better organized near an area of low pressure located
several hundred miles south-southwest of Manzanillo, Mexico.
Environmental conditions are conducive for additional development,
and a tropical depression could form during the next day or two
while the system moves northwestward to west-northwestward at 5 to
10 mph.
* Formation chance through 48 hours...high...60 percent
* Formation chance through 5 days...high...70 percent

[phil882]

Now TD-1E!

 

000
WTPZ41 KNHC 222047
TCDEP1
ZCZC MIATCDEP1 ALL
TTAA00 KNHC DDHHMM

TROPICAL DEPRESSION ONE-E DISCUSSION NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL EP012014
200 PM PDT THU MAY 22 2014

Deep convection associated with an area of low pressure well to the
southwest of Mexico has gradually become better organized during the
past 12 to 24 hours, and a 1708 UTC ASCAT-B pass indicated that the
system has a sufficiently well-defined center. Therefore,
advisories are being initiated on the first tropical depression of
the eastern North Pacific season. The initial intensity is set at
25 kt based on the ASCAT data and satellite estimates of T1.5 from
both TAFB and SAB.

The depression has been moving slowly toward the west-northwest
while located on the edge of a mid-level ridge extending west from
Mexico, and the initial motion estimate is 285/3 kt. The depression
is expected to remain just to the west of the ridge and to the south
of a deep-layer cyclone centered over California, which will likely
keep it in a weak steering environment for the next 3 to 4 days. In
fact, the ECMWF model even shows the depression becoming nearly
stationary or meandering for a few days due to the weak steering.
The official forecast shows a relatively slow track toward the
west-northwest during the next 5 days and is close to the model
consensus TVCE.

The depression is embedded in an environment of light vertical
shear, which will likely support at least gradual intensification
during the next few days. There is some disagreement among the
intensity models as to how much strengthening will occur, however.
For example, the statistical LGEM keeps the depression below
tropical storm strength for about 48 hours. On the other hand, the
SHIPS RI index indicates a 42e of a 25-kt increase in winds
within the next 24 hours. With the RI index relatively high, the
official forecast is higher than the LGEM for the first few days.
By days 4 and 5, vertical shear is expected to strengthen, and the
intensity is forecast to level off or decrease by the end of the
forecast period.

FORECAST POSITIONS AND MAX WINDS

INIT 22/2100Z 10.3N 107.4W 25 KT 30 MPH
12H 23/0600Z 10.5N 108.0W 35 KT 40 MPH
24H 23/1800Z 10.8N 108.6W 40 KT 45 MPH
36H 24/0600Z 11.1N 109.2W 45 KT 50 MPH
48H 24/1800Z 11.4N 109.7W 50 KT 60 MPH
72H 25/1800Z 11.7N 110.3W 55 KT 65 MPH
96H 26/1800Z 12.0N 111.0W 55 KT 65 MPH
120H 27/1800Z 12.0N 113.0W 50 KT 60 MPH

$
Forecaster Berg

[Yellow Evan]

Let the games begin.

[icebreaker5221]

Now TD-1E!

 

000

WTPZ41 KNHC 222047

TCDEP1

ZCZC MIATCDEP1 ALL

TTAA00 KNHC DDHHMM

TROPICAL DEPRESSION ONE-E DISCUSSION NUMBER 1

NWS NATIONAL HURRICANE CENTER MIAMI FL EP012014

200 PM PDT THU MAY 22 2014

Deep convection associated with an area of low pressure well to the

southwest of Mexico has gradually become better organized during the

past 12 to 24 hours, and a 1708 UTC ASCAT-B pass indicated that the

system has a sufficiently well-defined center. Therefore,

advisories are being initiated on the first tropical depression of

the eastern North Pacific season. The initial intensity is set at

25 kt based on the ASCAT data and satellite estimates of T1.5 from

both TAFB and SAB.

The depression has been moving slowly toward the west-northwest

while located on the edge of a mid-level ridge extending west from

Mexico, and the initial motion estimate is 285/3 kt. The depression

is expected to remain just to the west of the ridge and to the south

of a deep-layer cyclone centered over California, which will likely

keep it in a weak steering environment for the next 3 to 4 days. In

fact, the ECMWF model even shows the depression becoming nearly

stationary or meandering for a few days due to the weak steering.

The official forecast shows a relatively slow track toward the

west-northwest during the next 5 days and is close to the model

consensus TVCE.

The depression is embedded in an environment of light vertical

shear, which will likely support at least gradual intensification

during the next few days. There is some disagreement among the

intensity models as to how much strengthening will occur, however.

For example, the statistical LGEM keeps the depression below

tropical storm strength for about 48 hours. On the other hand, the

SHIPS RI index indicates a 42e of a 25-kt increase in winds

within the next 24 hours. With the RI index relatively high, the

official forecast is higher than the LGEM for the first few days.

By days 4 and 5, vertical shear is expected to strengthen, and the

intensity is forecast to level off or decrease by the end of the

forecast period.

FORECAST POSITIONS AND MAX WINDS

INIT 22/2100Z 10.3N 107.4W 25 KT 30 MPH

12H 23/0600Z 10.5N 108.0W 35 KT 40 MPH

24H 23/1800Z 10.8N 108.6W 40 KT 45 MPH

36H 24/0600Z 11.1N 109.2W 45 KT 50 MPH

48H 24/1800Z 11.4N 109.7W 50 KT 60 MPH

72H 25/1800Z 11.7N 110.3W 55 KT 65 MPH

96H 26/1800Z 12.0N 111.0W 55 KT 65 MPH

120H 27/1800Z 12.0N 113.0W 50 KT 60 MPH

$

Forecaster Berg

 

Believe it or not, this thing actually has a decent shot at making hurricane status.

[Yellow Evan]

Believe it or not, this thing actually has a decent shot at making hurricane status.

 

I'm not quite sure yet. I agree it has a shot, but I could see it being one of these situations where shear unexpectedly kick in after it reaches like 50 knts (like Narda last year).

[phil882]

Believe it or not, this thing actually has a decent shot at making hurricane status.

 

As long as it doesn't track too far northwest. The upper-level westerlies are pretty far south right now, but aren't likely to dig any further south the next five days. Some of the forecast model tracks  suggest that TD1E could continue to move NW, so its hard to be too confident with the intensity forecast until an established track direction emerges. A more westerly track or even little motion as the GFS and ECMWF suggest, respectively, would allow for a stronger system.

 

It's worth noting that it appears there might have been a Atmospheric Kelvin Wave passage recently, as evidence of the negative 200 hPa VP Anomalies in the filtered Kelvin Wave band the last few days. This has counteracted the +VP signal in the MJO filtered band and has favored upper-level divergence over a large portion of the East Pacific the last few days (aiding convective growth with TD 1E).

 

http://www.atmos.albany.edu/student/ventrice/real_time/maps/waves/westHem_analyses.html

 

[Superstorm93]

Nice shot of TD1E just before sunset

 

[Yellow Evan]

Given it looks pretty good, I'm thinking the odds of becoming a hurricane are slowly increasing. Conditions should be good for a few days at least. I don't think it'll bomb out, conditions don't look that good, though it's already surprised us once.

[HurricaneJosh]

Hurricane-flavored fish!

[Yellow Evan]

Upped to 30 knts at 9z. Looks like we could see a TS very soon.

[Ground Scouring]

000
WTPZ31 KNHC 231445
TCPEP1

BULLETIN
TROPICAL STORM AMANDA ADVISORY NUMBER 4
NWS NATIONAL HURRICANE CENTER MIAMI FL EP012014
800 AM PDT FRI MAY 23 2014

...DEPRESSION STRENGTHENS TO TROPICAL STORM AMANDA...


SUMMARY OF 800 AM PDT...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...10.9N 108.4W
ABOUT 620 MI...1000 KM SSW OF MANZANILLO MEXICO
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 5 MPH...7 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES

 

It's forecast to become a 65-kt hurricane in three days.

[icebreaker5221]

Official forecast up to 70 kt now by 18Z on the 26th.  Intensification should commence once those circulation centers become better aligned. 

[Yellow Evan]

Amanda seems to be getting better organized. Could very well be up to 40 knts tonight IMO

[Ground Scouring]

I'm having a hard time believing that Amanda will get stronger than 65-70 kt at most. There is substantial mid-level dry air intrusion / low-level stratocumulus from the W and NW of the circulation, and the convective pattern is more of a bursting type, with no indication of a CDO forming. Also, the overall structure is still sheared (tilted) along an axis from SSW to NNE. None of this bodes well either for RI in the short term or for a much stronger TC over the next three days. The LLC and the MLC are still unaligned. Yes, more models have trended upward with the intensity, with the LGEM peaking at 80 kt in two and a half days, but I think those trends are overdone.

[Yellow Evan]

Well, ATCF has it up to 45 knts.

[phil882]

I'm having a hard time believing that Amanda will get stronger than 65-70 kt at most. There is substantial mid-level dry air intrusion / low-level stratocumulus from the W and NW of the circulation, and the convective pattern is more of a bursting type, with no indication of a CDO forming. Also, the overall structure is still sheared (tilted) along an axis from SSW to NNE. None of this bodes well either for RI in the short term or for a much stronger TC over the next three days. The LLC and the MLC are still unaligned. Yes, more models have trended upward with the intensity, with the LGEM peaking at 80 kt in two and a half days, but I think those trends are overdone.

 

Well if Amanda undergoes rapid intensification in the next 24 hours (something the SHIPS RI index has been indicating) then this forecast goes out the window. Shear the last day or so has been negligible (again the system is currently still south of the stronger westerlies which are located NW of the system). This will play a role later in the forecast, but for the next 24-36 hours things are favorable for intensification, and I think the NHC's forecast at 11pm is very much in line with this possibility. Given the small inner core developing, there is an outside chance we could see a major hurricane out of this (but has to be in the next 24-36 hours). 

[Yellow Evan]

Tropical Storm Amanda is up to 50 knts looking very impressive tonight. It's starting to get an eyewall, and we could very well have a hurricane tomorrow afternoon baring a collapse. I still would not rule out a major quiet yet.

[Srain]

CDO looks very impressive over night and an eye feature is forming. Jack Beven now forcasting rapid intensification during the next 48 hours to a respectable 95kts and states that may even may be conservative.

[Mike.Ventrice]

Looks like Amanda is starting to develop an eyewall at the last couple of frames... 

[Superstorm93]

Looks like some rapid intensification may is be occurring. 

 

Should be around 70 knots by 11am 

 

EP, 01, 2014052412, , BEST, 0, 113N, 1097W, 65, 989, HU