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Learning Wx Lingo

  • Thread starter Thread starter Karla Dorman
  • Start date Start date

Karla Dorman

I've been reading the NOW forecasts, and can pretty much comprehend it, but a few things have me puzzled.

What are Tds (as in, ' ... soundings show that the Tds of this magnitude ....')? Touchdowns? Tropical disturbance?!? Can't figure out.

CIN? Convective ... something. And is that a good or bad thing?

CAPE as opposed to CAP? (Know a CAP is a lid, but is CAPE the opposite?)

Discrete?!? What is that?!?

Feel like an idiot, trying to understand wx lingo. Any and all answers will be greatly appreciated; thanks in advance.
 
Karla, I can help with a couple of these.

Td (more properly written with the d as a subscript) stands for dew point temperature.

CIN is convective inhibition.

CAPE stands for Convective Available Potential Energy.

Definitions for those last two are available at the links given.

Discrete, as a word, is used as opposing continuous. For example, temperature is continuous (you don't instantly jump from 82 to 83 degrees), but the number of tornadoes you've seen is discrete (you instantly jump from 0 to 1, or 2 to 3, or whatever.) I don't know what it means in specific regard to weather.
 
Travis Darling said:
Karla, I can help with a couple of these.

Td (more properly written with the d as a subscript) stands for dew point temperature.

CIN is convective inhibition.

CAPE stands for Convective Available Potential Energy.

Definitions for those last two are available at the links given.

Discrete, as a word, is used as opposing continuous. For example, temperature is continuous (you don't instantly jump from 82 to 83 degrees), but the number of tornadoes you've seen is discrete (you instantly jump from 0 to 1, or 2 to 3, or whatever.) I don't know what it means in specific regard to weather.
Click to expand...

As in discrete supercells. Discrete in this sense pretty much means isolated in nature.
 
Karla, on some web pages, I'm thinking the NWS forecast discussion is one, if the abbreviation is in blue script you can hold your pointer over or click on it and a pop-up will tell you what it means.
 
You are getting ready to see a lot more of those confusing acronyms now that we're getting into storm season, so I'll go ahead and explain the ones you are sure to see over the next few months.

LCL - that's lifted condensation level. You can basically think of it as the cloud base height. You want low LCL's for a good tornado threat. One of the biggest contributing factors to LCL's is the spread between the temperature and the dewpoint. The lower the spread the lower the LCL's are.

LFC - level of free convection. This is just the area where a surface parcel becomes warmer than the surrounding air and can rise freely.

SRH - storm relative helicity. You will see people say 0-1 SRH and 0-3 SRH. The numbers refer to which layer of the atmosphere you are measuring the helicity in. So 0-1km is the surface up to one kilometer. I don't want to give a full fledged explanation, but this plays a major role in tornado potential.

SR - storm relative

SHR - shear

EHI - energy helicity index. it's a composite indice that combines several things to give an overall threat of severe weather and tornadoes.

CU field - this is refering to a cumulus field. You usually get cumulus clouds forming along the boundary before a storm fires.

SPC - storm prediction center

NAM, GFS, RUC and European are all weather models.
 
Weather terms was going to be one of my first things to search for or ask about once I became a member, thanks for asking for me Karla! And thanks to everyone who has answered too :)
 
I just wanted to say thanks to everyone for sharing the lingo info!! ;)
 
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