East Pacific wave trying to become Tropical Depression Twenty-E

October 15, 2009

The National Hurricane Center has not upgraded the chances of development for Invest 93E, likely to be named Rick, as of 7AM CDT.  Those remain at 30%-50%.

I think it’s inevitable – and soon.  Mike Formosa of the Tropical Analysis and Forecast Branch writes in this morning’s tropical weather discussion:

THIS CONVECTION IS BECOMING BETTER ORGANIZED WITH BANDING FEATURES THAT WILL HAVE A HIGHER DVORAK RATING ON THE NEXT CLASSIFICATION. THE LOW IS IN AN AREA OF LOW SHEAR… ABUNDANT MOISTURE…AND WARMER THAN NORMAL SSTS.

He then breaks my heart by giving the system a medium chance of development within 48 hours.

Does this look like a system with a medium chance of development in 48 hours:

Invest 93E - Visible - Oct 15, 2009 15:15 UTC

Invest 93E - Visible - Oct 15, 2009 15:15 UTC

Since I”m limited on time I’ll show you the data and you can see why there should be some considerable excitement in this storm.

QuikSCAT

Invest 93E - QuikSCAT - Oct 15, 2009 11:47 UTC

Invest 93E - QuikSCAT - Oct 15, 2009 11:47 UTC

40kts (46mph or 74kph) wind vectors just to northeast of center of wave axis with 50kts (58mph or 93kph) further to northeast.  Dominant 30kts (35mph or 56kph) in northeastern quadrant.  Very sharp wave axis oriented east/west with strong convection in upper -60°C (-76°F), lower -70°C (-94°F) to north.  I wouldn’t be surprised if the center of the wave axis relocates beneath the convection.  However, due to the strong mid-level circulation I think the convection will develop further south.

Upper-level shear

Invest 93E - Shear - Oct 15, 2009 12:00 UTC

Invest 93E - Shear - Oct 15, 2009 12:00 UTC

anticyclone above with 5-10kt winds?  Nothing to rip apart cloud tops – only the anticyclone to pull away used energy.

Upper-level divergence

Invest 93E - upper-level divergence - Oct 15, 2009 12:00 UTC

Invest 93E - upper-level divergence - Oct 15, 2009 12:00 UTC

About as perfect as I think it can get to enhance outflow and convective development.

SST’s

Invest 93E - SSTs - Oct 14, 2009 22:52 UTC

Invest 93E - SSTs - Oct 14, 2009 22:52 UTC

The system will be over waters warmer than 29°C (84°F) for the first three days.  This will aid explosive development.  Unfortunately, I cannot find a good recent OHC map at this time.  Will keep my eyes open.

You can also notice in the QuikSCAT image above the total precipitable water values.  That’s plenty of moisture for the system to feed upon.

Given the circumstances, I think there’s an excellent chance of tropical development within the next 24 hours – 100%.  It’s already getting there.

Then, we ask, where does it go?

Forecast Models

As you would expect, there’s not much change though I did get my hands on the latest run of some guidance:

Invest 93E - Forecast guidance - Oct 15, 2009 12:00 UTC

Invest 93E - Forecast guidance - Oct 15, 2009 12:00 UTC

Besides the CLP5 the models take it more or less inline with what I saw from earlier runs off other model.

The CMC in 120 hours:

Invest 93E - CMC 120 hr forecast - Oct 15, 2009 12:00 UTC

Invest 93E - CMC 120 hr forecast - Oct 15, 2009 12:00 UTC

The GFS in 120 hours:

Invest 93E - GFS 120 hour forecast - Oct 15, 1200 UTC

Invest 93E - GFS 120 hour forecast - Oct 15, 1200 UTC

The NGP in 120 hours (a bit south):

Invest 93E - NGP - 120 hours - Oct 15, 2009 00:00 UTC

Invest 93E - NGP - 120 hours - Oct 15, 2009 00:00 UTC

The EMCWF in 120 hours (a bit south):

Invest 93E - EMCWF 120 hour forecast - Oct 15, 2009 00:00 UTC

Invest 93E - EMCWF 120 hour forecast - Oct 15, 2009 00:00 UTC

And the intensity guidance:

Invest 93E - intensity forecast guidance - Oct 15, 2009 12:00 UTC

Invest 93E - intensity forecast guidance - Oct 15, 2009 12:00 UTC

Clearly there is no reason whatsoever to think the system will become a hurricane.  I think the intensity guidance is an underestimate and I think Rick will be a category three hurricane in 72 hours.  The only concern I’d have is perhaps some mid-level dry air getting into the system going towards the end of the three-day period.  Other than that, I’d say conditions are ripe for rapid intensification or damn close to it.

By the way, of the models I’ve listed only the GFS and EMCWF go far enough to forecast a landfall next weekend.  The other models just don’t do forecasts much beyond five days in advance.

{ 16 comments… read them below or add one }

wrong-forecast October 15, 2009 at 12:48 PM

I’m going to laugh so hard if this thing fizzles before it even becomes a depression!!! BWAH HA HA HA HA

Reply

AggieMan October 15, 2009 at 1:10 PM

Dude, you’re a freaking dork…

Reply

TanquerayMan October 15, 2009 at 4:21 PM

You laughing, yet???

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stormfan October 15, 2009 at 12:53 PM

Think you just beat the NHC!!! they’ve just upgraded the chances to 50%.

000
ABPZ20 KNHC 151731
TWOEP
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1100 AM PDT THU OCT 15 2009

FOR THE EASTERN NORTH PACIFIC…EAST OF 140 DEGREES WEST LONGITUDE..

A LOW PRESSURE AREA LOCATED ABOUT 350 MILES SOUTH-SOUTHWEST OF THE
GULF OF TEHUANTEPEC HAS BECOME BETTER ORGANIZED OVER THE PAST FEW
HOURS. IF CURRENT TRENDS CONTINUE…A TROPICAL DEPRESSION COULD
FORM LATER THIS AFTERNOON OR TONIGHT AS THE SYSTEM MOVES
WEST-NORTHWESTWARD AT 10 TO 15 MPH. THERE IS A HIGH CHANCE…
GREATER THAN 50 PERCENT…OF THIS SYSTEM BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS.

ELSEWHERE…TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER CANGIALOSI/BEVEN

Reply

Tim Trice October 15, 2009 at 1:20 PM

Yea, and looking at the most recent loop (which I hadn’t done before writing the post), it’s clear this thing is getting its act together very quickly. Notice convection spreading to the south now. I wouldn’t be the least bit surprised if the NHC issues a special advisory and/or this thing goes immediately to being named Tropical Storm Rick

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MJ October 15, 2009 at 1:50 PM

Lupit looks equally impressive – one band on E side

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stormfan October 15, 2009 at 2:45 PM

The NHC is calling it 20E on the satellite page

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MJ October 15, 2009 at 3:11 PM

It’s being upgraded at 5PM AST. The NHC issued a renum statement

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stormfan October 15, 2009 at 3:21 PM

what’s a renum statement?

so are they going to name it a depression or a storm?

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MJ October 15, 2009 at 3:29 PM

i don’t know what header it’s issued under but it’s a reassignment of numbers. They dropped the 93E classification and reassigned 20W. Doesn’t say if it’ll be a depression or a storm. Patience, my young one…

Reply

stormfan October 15, 2009 at 3:42 PM

000
WTPZ45 KNHC 152039
TCDEP5
TROPICAL DEPRESSION TWENTY-E DISCUSSION NUMBER 1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP202009
200 PM PDT THU OCT 15 2009

CONVENTIONAL SATELLITE IMAGERY…DATA FROM THE ASCAT
SCATTEROMETER…AND SHIP REPORTS INDICATE THAT THE LOW PRESSURE
AREA CENTERED SOUTH OF MEXICO HAS ACQUIRED SUFFICIENT ORGANIZED
CONVECTION AND CIRCULATION TO BE DESIGNATED A TROPICAL DEPRESSION.
THE ASCAT DATA SHOWED MAXIMUM WINDS NEAR 30 KT ABOUT 60 N MI
NORTH-NORTHEAST OF THE CENTER…WHICH IS IN GOOD AGREEMENT WITH
SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB. THE CIRRUS
OUTFLOW IS CURRENTLY GOOD IN ALL DIRECTIONS.

THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 305/11. THE DEPRESSION
IS ON THE SOUTH SIDE OF A LOW/MID-LEVEL RIDGE EXTENDING FROM MEXICO
WESTWARD OVER THE PACIFIC. THE LARGE-SCALE MODELS FORECAST THIS
FEATURE TO PERSIST FOR THE NEXT 48-72 HR…AND THIS SHOULD STEER
THE DEPRESSION WEST-NORTHWESTWARD AT A SLIGHTLY SLOWER FORWARD
SPEED. AFTER THAT TIME…THE RIDGE IS FORECAST TO WEAKEN AS A
MID/UPPER-LEVEL TROUGH DEVELOPS OVER THE WESTERN UNITED STATES.
THE TRACK GUIDANCE DIVERGES DURING THIS TIME. THE HWRF AND GFDL…
WHICH ARE ON THE RIGHT SIDE OF THE GUIDANCE ENVELOPE…TURN THE
CYCLONE TO THE NORTH OR NORTHEAST BY 120 HR…WITH THE GFDL
FORECASTING THE CENTER TO BE NEAR SOUTHERN BAJA CALIFORNIA. THE
NOGAPS…CANADIAN…AND UKMET ARE ON THE OTHER SIDE OF THE
ENVELOPE…AND SHOW A SLOW WEST-NORTHWESTWARD MOTION AFTER 72 HR.
THE GFS AND ECMWF ARE IN BETWEEN THESE EXTREMES…WITH 120 HR
POSITIONS JUST SOUTH OR SOUTHWEST OF SOCORRO ISLAND. THE FORECAST
TRACK COMPROMISES BETWEEN THESE EXTREMES…WITH THE TRACK IN BEST
AGREEMENT WITH THE TVCN CONSENSUS MODEL FOR THE FIRST 72 HR AND
WITH THE GFS/ECMWF THEREAFTER.

THE DEPRESSION IS EMBEDDED IN A LIGHT VERTICAL WIND SHEAR
ENVIRONMENT OVER VERY WARM WATER…AND THE LARGE-SCALE MODELS
FORECAST THIS TO CONTINUE THROUGH AT LEAST 72 HR. ALL GUIDANCE IS
FORECASTING SIGNIFICANT AND RAPID STRENGTHENING DURING THE NEXT
72-96 HR…WITH THE HWRF FORECASTING THE CENTRAL PRESSURE TO FALL
BELOW 900 MB. THE RAPID INTENSIFICATION INDEX OF THE SHIPS MODEL
INDICATES A 60 PERCENT CHANCE OF 30 KT OR MORE INTENSIFICATION
DURING THE NEXT 24 HR. THE INTENSITY FORECAST THUS CALLS FOR FAST
STRENGTHENING…WITH THE DEPRESSION BECOMING A TROPICAL STORM BY
12 HR…A HURRICANE IN ABOUT 36 HR…AND A MAJOR HURRICANE IN ABOUT
72 HR. THE INTENSITY FORECAST IS SIMILAR TO THE SHIPS AND
INTENSITY CONSENSUS MODELS. THERE IS A CHANCE THAT THE CYCLONE
COULD STRENGTHEN FASTER THAN CURRENTLY FORECAST.

THE INITIAL RADII OF 12 FT SEAS ARE BASED ON TWO SHIP REPORTS
130 AND 170 N MI FROM THE CENTER IN THE EASTERN SEMICIRCLE.

FORECAST POSITIONS AND MAX WINDS

INITIAL 15/2100Z 12.1N 97.0W 30 KT
12HR VT 16/0600Z 12.6N 98.2W 40 KT
24HR VT 16/1800Z 13.0N 99.7W 55 KT
36HR VT 17/0600Z 13.4N 101.3W 65 KT
48HR VT 17/1800Z 13.9N 103.3W 80 KT
72HR VT 18/1800Z 15.0N 108.0W 100 KT
96HR VT 19/1800Z 17.0N 111.5W 110 KT
120HR VT 20/1800Z 19.0N 112.5W 115 KT

$$
FORECASTER BEVEN

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stormfan October 15, 2009 at 3:45 PM

excellent job with the forecast tim, nhc must’ve read your post!!!

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AggieMan October 15, 2009 at 3:49 PM

I honestly thought he was being too agressive or excited. That was a good call though, Tim. Congrats. Hopefully, the storm will follow suit…

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Tim Trice October 15, 2009 at 4:06 PM

Thanks but this one is easy – for now. Track-wise, models in good agreement with an anchored high. pretty simple. intensity is the tough part. i wouldn’t be a bit surprised if the forecast is under actuality. We’ll see. Obviously, I agree with the NHC’s forecast.

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wrong-forecast October 15, 2009 at 3:58 PM

oh please! you guys are ready to kiss his butt over what? a measely depression. so what if the nhc said the same thing he did. you fools treat it like the storms done. wait and see if it hits a 3 and baja like he says. I bet you a million dollars it doesn’t come close to either. like the rest of the season it’ll fade

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TanquerayMan October 15, 2009 at 4:19 PM

However, due to the strong mid-level circulation I think the convection will develop further south.

Good call on that one, too, Tim!

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