EPAC : TROPICAL DEPRESSION CARLOS (04E)

[Ed Mahmoud]

Carlos appearence is not so good as a few hours ago, cloud tops have warmed, the eye is "closed" again and it seems like a little dry air could be affecting it. Conditions still look good and I think that it will overcome those little problems.

WV imagery may not show a thin dry layer, but overall, it doens't look like dry air is a problem. See also Derek's Master's thesis on dry air and how it affects developed storms in a low shear environment.

[Ed Mahmoud]

Moving just South of due West (265º) at the end, slight weakening late. 2 days from the longitude of Hawai'i.




Should enhance the trades even if it misses...

[Macrocane]

Where can I read Derek'r thesis? By the way, Carlos seems to be shrinking, do you think that it could become an annular hurricane? if that's the case it will be less affected by hostile conditions isn't it?

[Ed Mahmoud]

Where can I read Derek'r thesis? By the way, Carlos seems to be shrinking, do you think that it could become an annular hurricane? if that's the case it will be less affected by hostile conditions isn't it?

I know no more than what Wikipedia can tell me about annular canes.


Looks around the U Miami web site.

He has linked it before. Maybe Google Fu will pay dividends...

[Ed Mahmoud]

Where can I read Derek'r thesis? By the way, Carlos seems to be shrinking, do you think that it could become an annular hurricane? if that's the case it will be less affected by hostile conditions isn't it?

I know no more than what Wikipedia can tell me about annular canes.


Looks around the U Miami web site.

He has linked it before. Maybe Google Fu will pay dividends...

Google - first result

http://orca.rsmas.miami.edu/~derek/thesis/dec_07_final/DOrttF07.pdf

[Cyclenall]

How can you get data over the open ocean? What observing stations are there? Maybe when this gets near Hawaii, the G-IV will fly. But until then... little to no data

The GFS model is using some initialization data isn't it? That's what I'm talking about, why is it garbage right now compared to usual because I don't remember this happening before. About getting data over the open ocean, that should improve soon I hope.

How can you get data over the open ocean? What observing stations are there? Maybe when this gets near Hawaii, the G-IV will fly. But until then... little to no data

Satellite data... buoy observations.

Long time no see.

Where can I read Derek'r thesis? By the way, Carlos seems to be shrinking, do you think that it could become an annular hurricane? if that's the case it will be less affected by hostile conditions isn't it?

Annular talk! Not again! You can check to see if it's becoming annular when the certiera (sp?) have been met on that index that I forgot the name of. I asked once if it was possible for a TC to shrink and there wasn't any evidence that it has ever happened (mature hurricanes).

Hurricane Carlos does look horrid, but I can tell it's in a re-structuring phase and it will look a bit smaller. Just looking at the IR, you would never know that was a hurricane but just a blob of convection.

[senorpepr]

How can you get data over the open ocean? What observing stations are there? Maybe when this gets near Hawaii, the G-IV will fly. But until then... little to no data

The GFS model is using some initialization data isn't it? That's what I'm talking about, why is it garbage right now compared to usual because I don't remember this happening before. About getting data over the open ocean, that should improve soon I hope.

That's the point, Cyclenall: there's really no data for the models to work with. There's no land observations between Mexico and Hawaii so you're left with ship reports (which can be suspect) and a few buoys (which are around the equator). So how can you initialize the model when you have nothing to initialize it with? Satellite data won't do much good. (I'm not a modeler, but IIRC, satellite data has very limited application to GFS... if at all.)

To stress my point about the lack of data... below is a surface plot from 00Z. The map is centered directly over Carlos and is expanded out 5,000 n mi. You can obviously see the data available in N America as well as in Hawaii. You can see several ship reports N of 25°N (too far N to help out with Carlos). There are a handful of buoys along the equator... but all S of 9°N. (Not much help either. It only provides wind, air temperature, and sea temperature data. No pressure initialization from these.)

Basically... the closest pressure report to Carlos is from the ships SE-S of Baja California...some 930 n mi downstream from Carlos.

Looking upstream (which will help the forecast) is much bleaker. A few reports to the N are some 1000 n mi away. To the S you're looking at about 1500 n mi. Directly upstream is Hawaii, which is around 2000 n mi away. None of this observations will really help paint what is going on.



Of course, surface data is just one small piece of the puzzle. Soundings will give a better, 3-D look at the atmosphere and will help direct where the cyclone is headed. Here are the 200 hPa plots from 00Z. Same map settings as before. You'll see it's pretty much nothing.



This is why recon is a key part in tropical cyclone forecasting. Of course, right now there's not a great need to run recon. What is Carlos going to affect in the next five days? Nothing really. Not even shipping interests, except for an odd boat or two.

[senorpepr]

WTPZ34 KNHC 120831
TCPEP4
BULLETIN
HURRICANE CARLOS ADVISORY NUMBER 9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP042009
200 AM PDT SUN JUL 12 2009

...CARLOS MOVING WESTWARD OVER THE OPEN WATERS OF THE EASTERN NORTH PACIFIC...

AT 200 AM PDT...0900 UTC...THE CENTER OF HURRICANE CARLOS WAS LOCATED NEAR LATITUDE 10.5 NORTH...LONGITUDE 120.0 WEST OR ABOUT
1085 MILES...1745 KM...SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA.

CARLOS IS MOVING TOWARD THE WEST NEAR 13 MPH...20 KM/HR...AND A MOTION JUST NORTH OF DUE WEST IS EXPECTED DURING THE NEXT COUPLE OF DAYS.

MAXIMUM SUSTAINED WINDS ARE NEAR 85 MPH...140 KM/HR...WITH HIGHER GUSTS. ADDITIONAL STRENGTHENING IS FORECAST AND CARLOS COULD BECOME A MAJOR HURRICANE DURING THE NEXT DAY OR TWO.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 25 MILES...35 KM...FROM THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 85 MILES...140 KM.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 980 MB...28.94 INCHES.

...SUMMARY OF 200 AM PDT INFORMATION...
LOCATION...10.5N 120.0W
MAXIMUM SUSTAINED WINDS...85 MPH
PRESENT MOVEMENT...WEST OR 270 DEGREES AT 13 MPH MINIMUM CENTRAL PRESSURE...980 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT 800 AM PDT.

$$
FORECASTER KIMBERLAIN/PASCH

[senorpepr]

WTPZ44 KNHC 120838
TCDEP4
HURRICANE CARLOS DISCUSSION NUMBER 9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP042009
200 AM PDT SUN JUL 12 2009

SATELLITE IMAGERY SUGGESTS THAT CARLOS MAY HAVE ENTERED A PERIOD OF
ARRESTED DEVELOPMENT DURING THE PAST FEW HOURS...AS THE
INTERMITTENT EYE FEATURE HAS DISAPPEARED AND AN ASYMMETRY IS NOTED
WITHIN THE CENTRAL CONVECTION. AS A RESULT...DVORAK T-NUMBERS HAVE
LEVELED OFF...WITH ESTIMATES OF 4.0 AND 4.5 FROM SAB AND TAFB...
RESPECTIVELY. GIVEN CURRENT TRENDS AND SATELLITE ESTIMATES...THE
INTENSITY IS MAINTAINED AT 75 KT.

CARLOS SHOULD ENCOUNTER WEAK ENVIRONMENTAL SHEAR AND WARM SEA
SURFACE TEMPERATURES ALONG THE FORECAST TRACK DURING THE NEXT 2 TO
3 DAYS...WHICH SHOULD FAVOR ADDITIONAL STRENGTHENING. HOWEVER...
THE SHIPS MODEL GUIDANCE NO LONGER INDICATES THAT CARLOS WILL BECOME
A MAJOR HURRICANE AS A CONSEQUENCE OF MORE MARGINAL THERMODYNAMIC
PARAMETERS. IN ADDITION...THE SHIPS RAPID INTENSIFICATION INDEX IS
NOT AS EMPHATIC AS IT WAS PREVIOUSLY. THE OFFICIAL FORECAST IS ONLY
A LITTLE LESS BULLISH THAN THE PREVIOUS ONE AND STILL BRINGS CARLOS
TO MAJOR HURRICANE STATUS IN 36 TO 48 HR. THIS IS ALSO A
COMPROMISE BETWEEN THE LATEST HWRF AND GFDL HURRICANE MODEL WIND
SPEED FORECASTS...WITH THE FORMER MODEL BEING SIGNIFICANTLY MORE
AGGRESSIVE. THEREAFTER...THE COMBINATION OF INCREASING WESTERLY
FLOW ALOFT AND COOLER WATERS SHOULD RESULT IN GRADUAL WEAKENING.

THE INITIAL MOTION IS ESTIMATED AT 270/11. A DOMINANT MID- TO
UPPER-LEVEL SUBTROPICAL RIDGE NORTH OF THE CYCLONE SHOULD KEEP
CARLOS ON A GENERAL WESTWARD COURSE OVER THE NEXT FEW DAYS...WITH
SOME SUBTLE INCREASE IN LATITUDE TOWARD THE END OF THE FORECAST
PERIOD. MODELS CONTINUE TO DISAGREE...HOWEVER...ON THE PREDICTED
FORWARD SPEED OF CARLOS BEYOND 96 HR...WITH THE GFDL AND HWRF
NOTABLY FASTER THAN THE UKMET AND ECMWF. THE OFFICIAL TRACK IS
CLOSE TO THE PREVIOUS NHC TRACK AND ALSO TO THE TO THE DYNAMICAL
MODEL CONSENSUS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 12/0900Z 10.5N 120.0W 75 KT
12HR VT 12/1800Z 10.6N 121.8W 85 KT
24HR VT 13/0600Z 10.8N 124.1W 95 KT
36HR VT 13/1800Z 11.1N 126.6W 100 KT
48HR VT 14/0600Z 11.4N 128.8W 100 KT
72HR VT 15/0600Z 12.2N 133.4W 95 KT
96HR VT 16/0600Z 13.0N 138.0W 85 KT
120HR VT 17/0600Z 14.0N 142.5W 75 KT

$$
FORECASTER KIMBERLAIN/PASCH

[Iceman56]

Wanted to chime in here to dispel the rumor that seems to be going around about how data void the oceans are. It is true that there is not a lot of conventional data such as METARs, Synoptic Obs, and RAOBs, there are several other data rich sources which help to make up for it.

The two most important sources of model data over the water are satellite data, and scatterometer data. Scatterometer data is huge at filling the void as tropical weather is very dependent on subtle low level convergence/divergence patterns, with little or no dependency on baroclinic influences. Although much less frequent, when you get a Quikscat pass, you get many, MANY more wind vectors than the METAR network will give you.

As far as satellite data goes, everything from brightness temperatures, to satellite sounder data (much improved over the past several years), to sophisticated cloud tracking algorithms used at various wavelengths help to create the 3D picture over the oceans.

There is also research ongoing which is studying the effects of including long-range oceanic lightning data into the model initializations.

I would not think of claiming that this makes up for the loss of other datasets, or RECON, but it's not nearly as data void as some of you may think.

[senorpepr]

Wanted to chime in here to dispel the rumor that seems to be going around about how data void the oceans are. It is true that there is not a lot of conventional data such as METARs, Synoptic Obs, and RAOBs, there are several other data rich sources which help to make up for it.

The two most important sources of model data over the water are satellite data, and scatterometer data. Scatterometer data is huge at filling the void as tropical weather is very dependent on subtle low level convergence/divergence patterns, with little or no dependency on baroclinic influences. Although much less frequent, when you get a Quikscat pass, you get many, MANY more wind vectors than the METAR network will give you.

As far as satellite data goes, everything from brightness temperatures, to satellite sounder data (much improved over the past several years), to sophisticated cloud tracking algorithms used at various wavelengths help to create the 3D picture over the oceans.

There is also research ongoing which is studying the effects of including long-range oceanic lightning data into the model initializations.

I would not think of claiming that this makes up for the loss of other datasets, or RECON, but it's not nearly as data void as some of you may think.

Thanks for sharing this. I wasn't sure how or if forms of satellite data were ingested into the models.

[HURAKAN]

Interesting Carlos.

[Derek Ortt]

from what I understand and may be wrong, satellite data is weighted heavier by NOGAPS than by GFS

[cycloneye]

Is a very small system (Iris,Charley type) with a small eye and the track has not nudged to the north,only a strait line westward.

[tolakram]

The SST Display on the floater indicates Carlos is moving into a small area of lower SST. Are these correct?

http://www.ssd.noaa.gov/goes/flt/t7/flash-avn.html

[HURAKAN]

intensity of convection is decreasing

[cycloneye]

12/1200 UTC 10.4N 120.2W T4.0/4.5 CARLOS -- East Pacific

http://www.ssd.noaa.gov/PS/TROP/tdpositions.html

[cycloneye]

12 UTC Best Track mantains intensity at 75kts

EP, 04, 2009071212, , BEST, 0, 104N, 1204W, 75, 980, HU,

ftp://ftp.tpc.ncep.noaa.gov/atcf/tcweb/ ... 009.invest

[Derek Ortt]

the upper level divergence is better to the west. This is likely why we have seen weakening this morning

[Macrocane]

I was expecting this morning a beatiful hurricane and I found a hurricane that looks like a tropical storm. Wind shear is still low and is diminishing, there is no dry air entering, SST are warm enough so I think it has the chance of strengthen again, but I'm not sure if it will reach cat 3.