Basement-dwelling pseudo-otaku with a thrill for forecasting on the side.
By: KoritheMan, 4:07 AM GMT on February 20, 2014
Important notice: The information contained herein, unless otherwise specified, was written entirely by me. The parts that were assimilated via external sources were cited and given full credit. This report is not meant to supersede the official one from the National Hurricane Center. It is meant merely to reflect my own opinion on the meteorological events contained therein.
Tropical Cyclone Report
Tropical Storm Karen
October-6 October 2013
Karen was a tropical storm that reached its peak immediately after formation. It then moved toward the northern Gulf Coast while gradually weakening, ultimately dissipating not far off the coast of southern Louisiana.
a. Synoptic History
The tropical wave that triggered the formation of Karen moved off the coast of Africa on 16 September. There was little convection accompanying the passage of this wave across the Atlantic Ocean, making the specifics of its passage rather difficult to observe. Based primarily on extrapolation, the wave is estimated to have approached the Lesser Antilles on 25 September. Shower activity began to increase on 28 September as the wave moved across the central Caribbean Sea; this relative amplification appeared to be more related to a highly diffluent synoptic upper flow than to any large-scale evidence of tropical cyclogenesis within the tropical wave circulation, however, and the upper-tropospheric westerly shear was too strong for development at that time. Nonetheless, scatterometer ambiguities suggest that a sharp wind shift developed at the surface that day in association with the tropical wave axis while it was centered a couple hundred miles off the coast of western Colombia, with the associated mid-level circulation displaced about 25 to 35 nautical miles east of the sharpening low-level wave axis due to westerly shear. The wave turned northwestward and moved toward the northwestern Caribbean Sea in between a building low- to mid-level ridge over the western Atlantic and an upstream upper-level trough that was developing over the western United States. The system slowed down a little over the next couple of days as it moved steadily toward the Yucatan Channel along the southwestern periphery of the subtropical ridge.
The vertical shear slowly decreased as a small upper low over the northern portion of the Yucatan Peninsula moved westward into the Bay of Campeche and deamplified. The first evidence of convective banding was noted around 0600 UTC 2 October. Dvorak classifications increased later that day as more prominent banding developed amidst intensifying central convection, and it is estimated that the system become a tropical cyclone at approximately 0000 UTC 3 October while centered about 75 miles southeast of Cancun, Mexico; since sustained tropical storm force winds were already present east of the low, the transition to a tropical cyclone was one that resulted in the immediate manifestation of a tropical storm. The “best track” chart of the tropical cyclone’s path is given in Fig. 1, with the wind and pressure histories shown in Figs. 2 and 3, respectively. The best track positions and intensities are listed in Table 1. There was only slight additional strengthening subsequent to Karen's formation, and the brief reduction in westerly shear the system found while over the northwestern Caribbean Sea soon gave way to even stronger shear as Karen moved across the southern and central Gulf of Mexico. Karen reached its peak intensity of 55 kt near 1200 UTC that day, when it was centered just north of the northern coast of the Yucatan Peninsula.
Satellite pictures showed that the low-level circulation started to become exposed well to the west of an area of persistent deep convection that pulsated for a couple of days in a strongly sheared but highly diffluent upper environment to the east of a highly amplified upper-level trough that was moving slowly across the central United States; this disorganized structure was confirmed by aerial reconnaissance soon after Karen's formation. Continued southwesterly to westerly shear and dry air entrainment contributed to a steady degradation in Karen's cloud structure and maximum winds after formation, along with a gradual decay of the circulation from the lower troposphere upward as the system approached the northern Gulf Coast. Karen decelerated significantly as it approached the coast of Louisiana around midday 4 October, with microwave data showing an eastward tilt of the lower- and mid-tropospheric vortex centers; an ASCAT pass around 1550 UTC that same day (not shown) also indicated that the surface circulation was becoming less well-defined.
The cyclone's deceleration was likely due to the lower- and mid-level circulations shearing apart, since the synoptic steering flow around the storm still appeared to be reasonably well-defined. Karen weakened to a tropical depression around 1800 UTC 5 October as the shear increased further. Located about 100 miles south of Morgan City, Louisiana, Karen turned eastward ahead of an approaching cold front later that day, roughly paralleling the coast of southern Louisiana. Karen decayed further into a convectiveless remnant area of low pressure shortly after its movement toward the east, and the best track of the cyclone is terminated after 0600 UTC 6 October. The remnants enhanced shower activity over sections of northwest Florida before emerging into the western Atlantic and becoming entangled with a frontal zone.
b. Meteorological Statistics
Observations in Tropical Storm Karen (Figs 2 and 3) include satellite-based intensity estimates from the Tropical Analysis and Forecast Branch (TAFB) and Satellite Analysis Branch (SAB) using the Dvorak satellite interpretation technique. Objective Dvorak techniques assimilated by the University of Wisconsin CIMSS group were also useful in depicting the intensity and potential center locations of Karen. In addition, there were a total of 12 reconnaissance missions conducted into the tropical cyclone, which were of course incorporated into the final "best track" data of the tropical cyclone.
Operationally, Karen was assessed to have become a tropical storm around 1200 UTC 3 October; in this post-season analysis of the cyclone, however, it is presumed that the system actually reached tropical storm strength much earlier, nearer to 0000 UTC 3 October. This is based on unofficial but believable observations of westerly winds in Cancun, located along the northeastern tip of the Yucatan Peninsula just east of Karen's formative center first being reported at 0148 UTC local time and continuing until 0544 UTC, at which time Karen had already moved into the southern Gulf of Mexico; winds shifted to a general southwesterly direction after that as the center moved by to the north. An extrapolated 0236 UTC ASCAT pass that same day, in tandem with the surface observations, suggests that the surface circulation, though present, was still somewhat elongated southwest to northeast at the time of formation. Although an Air Force Reserve Hurricane Hunter aircraft flight into the system just a couple hours earlier did not find a closed surface circulation, it should be noted that much of the western half of Karen's circulation was over the Yucatan Peninsula during that time, outside the authorized airspace for the launching of dropsondes. Finally, the satellite presentation continued to improve for several hours subsequent to the recon flight, before Karen encountered more hostile upper-level conditions over the Gulf proper; the expansion of the rather vigorous convection lends additional credibility that the already strong circulation did not take long to work down to the surface after the aircraft departed. All of this data together implies that a 0000 UTC 3 October timeframe more or less seems to be the most accurate window in which to assess Karen as a tropical storm in the final "best track" of the storm.
Karen's peak intensity of 55 kt is estimated to have occurred about twelve hours after the time of formation. This is based on several bias-corrected SFMR observations of 50 to 55 kt as measured by a reconnaissance aircraft around and just after 1500 UTC 3 October. It should be noted that satellite, recon, and microwave data collectively suggests that Karen's center was located to the west of the deepest convection even at the time of peak intensity, attesting to the unfavorable 200 mb wind environment in which the cyclone traversed over the Gulf of Mexico. Similar strengthening episodes with sheared tropical cyclones has been observed in the past, most recently with Hurricane Lili in 2002. Perhaps this is because in such cases the vertical shear has not actually permeated the core.
There were no reports of tropical storm force winds over either the Yucatan Peninsula or the northern Gulf Coast. However, several offshore oil rigs reported sustained tropical storm force winds while Karen moved across the Gulf of Mexico, and those observations are listed in Table 2.
Karen is one of only seven named tropical cyclones to develop or move into the Gulf of Mexico since 1950 and dissipate before making landfall. The others were: Inga (1961), Henri (1979), Jeanne (1980), Alberto (1982), Edouard (1984), and Bonnie (2010). While Hurricane Ida of 2009 was also not a tropical cyclone at landfall, that cyclone was extratropical rather than full on dissipated, so Ida was not included in the above list for this report.
c. Casualty and Damage Statistics
Karen is not known to have caused any fatalities, and no significant damage has been reported from either Yucatan or the United States Gulf Coast.
d. Forecast and Warning Critique
The formation of Karen was very well predicted, except just before genesis. It was first mentioned in Tropical Weather Outlooks (TWOs) at 0600 UTC 29 September, which was nearly four days prior to genesis; at the time, the system was assessed to have a "low" (less than 30%) chance to become a tropical cyclone in the enusing 48 hours. Probabilities were increased to the "medium" (30 to 50%) category at 0600 UTC 1 October, even after a temporary reduction in genesis predictions was noted on 30 September. Finally, probabilities were increased to the "high" category (greater than 50%) at 1800 UTC 2 October, about six hours before the time of genesis.
Intensity forecasts with Karen were exceptionally good, averaging about 5 to 10 kt in terms of predictive error. It was correctly predicted that the upper-level winds over the Gulf would remain too strong to enable much additional development, despite global model forecasts to the contrary.
Track forecasts with Karen were also well-founded, although they in general exhibited a slight eastward bias while the system was well offshore, and then exhibited a net westward bias while Karen was closer to the southeastern tip of Louisiana.
Table 1. Watch and warning history for Tropical Storm Karen 3-6 October, 2013.
Image credit: National Hurricane Center (NHC).
Date/Time (UTC), Latitude (N), Longitude (W), Pressure (mb), Wind speed (kt)
03 / 0000 20.5 86.3 1004 40
03 / 0600 21.4 86.7 1002 45
03 / 1200 22.0 87.4 1000 50
03 / 1800 22.7 87.8 999 55
03 / 2100 23.2 88.2 998 55
04 / 0000 23.7 88.7 999 50
04 / 0600 24.6 89.7 1000 45
04 / 1200 25.1 90.0 1001 45
04 / 1800 25.6 90.3 1001 45
05 / 0000 26.0 90.5 1003 35
05 / 0600 26.5 91.1 1005 35
05 / 1200 27.1 91.4 1006 35
05 / 1800 27.6 91.6 1007 30
06 / 0000 28.1 91.8 1007 30
06 / 0600 28.1 91.6 1008 25
03 / 2100 23.2 88.2 998 55 - minimum pressure
Table 2. Best track statistics for Tropical Storm Karen, 3-6 October 2013. The statistics are plotted at six-hourly intervals, except for minimum pressure/maximum wind estimates, which can occur at differing intervals.
Figure 1. Best track positions for Tropical Storm Karen, 3-6 October 2013.
Figure 2. Selected wind observations and best track maximum sustained surface wind speed curve for Tropical Storm Karen, 3-6 October 2013. Aircraft observations have been adjusted for elevation using 90%, 80%, and 80% adjustment factors for observations from 700 mb, 850 mb, and 1500 ft, respectively. AMSU intensity estimates are from the Cooperative Institute for Meteorological Satellite Studies technique. Dashed vertical lines correspond to 0000 UTC.
Image credit: National Hurricane Center (NHC).
Figure 3. Selected pressure observations and best track minimum central pressure curve for Tropical Storm Karen, 3-6 October 2013. AMSU intensity estimates are from the Cooperative Institute for Meteorological Satellite Studies technique. KZC P-W refers to pressure estimates derived using the Knaff-Zehr-Courtney pressure-wind relationship. Dashed vertical lines correspond to 0000 UTC.
Image credit: National Hurricane Center (NHC).
e. References and Credits
While this report -- including the interpetation of data -- was authored entirely by me, I do not claim ownership of any of the data contained herein, nor is this report meant to supesede the one from the National Hurricane Center, which functions as a government weather agency. The Dvorak intensity and watch/warning tables were taken directly from the agency's official report on Karen, which is linked to below for reference.
The data used in this report were unearthed from a variety of sources, including:
CIMSS synoptic data archive
NHC Karen TCR
RAMMB CIRA Tropical Cyclone Archive
The Navy Research Lab's microwave image archive
US Air Force and hurricane hunter flight data archive
By: KoritheMan, 5:16 AM GMT on February 17, 2014
In my previous entry pertaining to this topic, I highlighted one of the more overt social norms that I don't sympathize with as someone who knows he's socially awkward and doesn't care: being direct and upfront with your questions, thoughts, and intentions being seen as "bad" somehow. Before I move on to the point of this entry, I feel it would be in the best interest of all my readers for me to come out and say two things: a) I don't care if I'm socially inept; I know I am and I consider it an integral part of my overall personality. And b)... I just... if I can't properly rationalize something, I can't attempt to establish and follow it as a standard paradigm. Luckily I have an in situ example of what I'm talking about: read my previous blog (particularly the comments) about religion. As some of you guys have perhaps extrapolated from even that little snippet, what I'm getting at is that if I can't understand or see a viewpoint (in this case, a social norm) as logical or rational, I literally can't follow it and assimilate it to myself. If it lacks a solid foundation, I'm just going to ignore it on grounds of it being ridiculous. This is why I consider myself an iconoclast, and why I see no utility in changing in order to meet conventional standards I don't agree with.
But that particular part of the aforementioned article made me come to a stunning while not so stunning (it was an epiphany to me, darnit!) realization: that people are uncomfortable by abnormalities (people that don't adhere to social norms/etiquette, is what I'm getting at for this blog). Social awkwardness is looked down upon because people fear anomalies. They fear change. They look down on people who are different from themselves (which is ironic considering we're taught at an early age to overlook said differences), because (and this is the main point, the epiphany I had) they feel threatened! If someone else is comfortable with themselves in certain situations, the person that isn't thinks that the person that's comfortable shouldn't be comfortable; they're "weird" for being comfortable with something the majority of people (again, due to societal upbringing) are not. I'm still trying to figure out why everyone is so easily weirded out by the most random of things.
Anyway, I hope you guys leave some comments in this blog; I tried to make it as clear and concise as possible. If you guys feel I've overlooked something important (in either direction -- for or against social norms), feel free to drop it in the comments, constructive or otherwise.
By: KoritheMan, 2:25 PM GMT on February 05, 2014
I know this is a weather community, that some people may be offended by this sort of thing, da da da. But with all the other non-weather related blogs I see frequently plastered on this site, I don't see why -- controversial or not -- this type of discussion should be stifled or immediately dismissed. Keep an open mind, and everything will be okay. I implore the WU admins not to delete this. If they do, whatever. Can't say I didn't try. Anyway, coming to the point of this now...
Finally coming to the point of this topic, I'm friends with this Christian dude on Facebook. Another friend of mine is also friends with the guy. The first guy is named Evan, while the second guy is called Chris. Anyway, Evan posted a status update about creationism vs evolution, and naturally there was some devolving into a couple of nihilistic comments. Chris posts a response arguing, essentially, that there should only be two logical possibilities: that god exists or that nihilism is absolutely true. If god does not exist, the only alternative is nihilism. And if we assume nihilism to be a valid maxim, we have to assume all of the implications and encumbrances that come with that. If nihilism is true, then we as individuals have no objective value. And if we have no objective value, we have no basis to make even a relative claim of self-fulfilled purpose, which effectively renders the common "create your own purpose" counter to the nihilistic paradigm vacuous. Because in order to even presume that we have actual purpose -- even relative purpose -- that relativity has to be compared to something. His actual post verbatim went like this:
What I think is the most intellectually accurate and honest response is that there are two "logical" viewpoints. Either God exists, or nihilism is actually true in practice.
What I mean to say is that there are a lot of people out there who find the usual nihilistic response "make your own meaning" to be satisfactory. Unfortunately, if there is no such thing as objective value *in reality*, then this is really just a giant lie. Things can only even have relative value if you yourself already have value, and if nihilism is true, then you do not have value. None at all. And neither does your own sense of value, or your feeling of something be "valuable" to you. And while it is perfectly fine to "feel" this way in the sense that you are fully capable of doing so, it does not actually mean it is correct any more than thinking you can walk through walls when you can't. It is not self consistent or intellectually honest and logical to believe in only "parts" of what is essentially nihilism. It has nothing to do with whether a person is capable of this or not, and everything to do with whether or not you are deceiving yourself / being deceived, which you are if you say that there is no such thing as objective value but still think / talk / live in consideration of a sense of relative value.
The only response to nihilism, or should I say, the only other self consistent possibility, is if God exists. All philosophical inquiry where the assumption of God's existence is absent ultimately leads to nihilism. And nihilism ultimately leads to the total break down of philosophical discourse and logical argument. People will try to deny it, but time and time against since the Ancient Greeks, this has proven to be the case. Ironically enough, Nietzsche, who is often credited with the modern justification for nihilism, also said that in his opinion nihilism MUST be overturned. In his view, modern philosophers would have to find a way to respond to and defeat nihilism, because nihilism was the "will to nothingness" and in the face of it nothing could actually be fundamentally logically proven. And of course there is only one response to that.
God is, or perhaps I should say should be, a "necessary assumption" in philosophy. It is a maxim. All philosophy breaks down without the assumption of the existence of God, JUST like all of math breaks down without the assumption of the existence of numbers or all of physics breaks down without the assumption of causality. Without the existence of God, there is no fundamental source of value, no fundamental source of truth or knowledge, and no fundamental source of being.
It will never be an issue of proof vs. lack of proof, because it is logistically impossibly to prove the existence of what is essentially an infinite. But there is good and perfectly valid reason to believe in the existence of God. That, in the face of the obvious impotence of nihilism, is all that is really required. Nihilism, true nihilism, is ultimately self defeating, and the only reason most people do not realize that is because they only "selectively" engage in it. The assumption of the existence of God however is not self defeating.
What's everyone's thoughts on this? I've been atheist since the 2007-2008 timeframe, and I can honestly say I've never come across something that made me question the very foundation of my worldview to this magnified degree.
The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.