Jump to content
  • Member Statistics

    17,502
    Total Members
    7,904
    Most Online
    Weathernoob335
    Newest Member
    Weathernoob335
    Joined

Weather References and Newbie Information


burgertime
 Share

Recommended Posts

Since winter is coming up I figured it might be good to have a little database for new SE posters. I know someone did this before but I couldn't find it. This is very basic so if I make any mistakes please let me know. Also feel free to add links you would like me to add to this or other information that can come in handy. If I screwed anything up don't feel bad about hurting my feelings, just tell me what is wrong and I'll change it.


Maps:

There are a few things to know about maps in general if you are new to weather watching. One of the most important things to realize is how weather models create the maps hobbyist and professionals use to forecast the weather. Weather models which create the maps are super computers. Before a map is made, this super computer takes information from the atmosphere (via airplanes, weather balloons, etc..) and use math to create thousands of different scenarios. It then takes the scenario that comes up the most and creates the map. So it's a statistical output based on math using the information it has about our atmosphere at that given time. For that reason a storm that is on a weather map may not happen since there is no way to 100% predict something as unstable as our atmosphere. Of course no true professional takes a map totally at face value, they use their education and experience in tandem with weather models to make a prediction they feel will be the most accurate.

GFS - Global Forecast System (weather map) AKA GooFuS (joke phrase for GFS) (Long Range)

The GFS runs at the following times: 6z - 5 A.M. 12z - 10:30 A.M. 18z - 4:30 P.M. 00z 10:30 P.M. these times typically represent when you can go on the board and will see analysis as the maps roll out. The GFS goes out to 384 hours at which point it is typically not very accurate.

LINK TO FREE GFS MAPS

(GFS 850mb map)
IF9nF.png



Euro - European Centre for Medium-Range Weather Forecasts (ECMWF) AKA Euro AKA European Model AKA Dr. No (medium range) AKA Eurotrash

12z - 12:30 P.M. 00z - 12:30 A.M. The Euro only runs twice per day. Wunderground now has a great free Euro map that runs to 180 hours out! It even shows snow totals. It can be found HERE use the panel on the right hand side of the screen to control maps.

LINK TO FREE EURO MAPS

(Euro map)

4BLAJ.gif


NAM - North American Model (short range)

6z - 4 A.M. 12z - 9:00 A.M. 18z - 2:30 P.M. 00z 9:00 P.M.

the NAM has the same layout as the GFS

LINK TO FREE NAM MAPS

GGEM - This is the Canadian Model AKA Canadian (medium range)

LINK TO FREE GGEM MAPS

EC_GGEM_QPF_48HR_12z_FEB_6.jpg


These are the four main maps used on the board. Additionally here are links to more resources

 

AmericanWX Maps - Now AmericanWx has models! These are awesome and inexpensive. Not only that but you support the board by using these maps. I strongly suggest you subscribe to this service!

Instant Weather Maps (best source for GFS/NAM maps)

NCEP MODEL GUIDENCE

RALEIGHWX WEATHER DATA PAGE

PSU E-WALL MAPS PAGE

WEATHERONLINE.CO.UK

MeteoBlue

RUC MAPS

HRRR MAPS

Wunderground Model Maps (best source for free Euro maps)

Meteocentre Maps

 

850mb zero degree isotherm/line - This refers to the 850mb line which typically is used to determine where snow will fall. You want to be above this line and not below it (when looking at a map). Often this is what we first look for when trying to get snow. This line typically works like a rain snow line, again you want to be north of this line when looking at a map for snow. The 850 temp is at around 5000 ft, so the surface temps can often be above freezing when the 850 temps would normally indicate snow. Also, a warm layer during sleet events often develops above 850mb. So the point is, in order get snow a lot has to go right then just having the blue line in your favor. (thanks to members schlontz and usedtobe for additional info)

(GFS 850mb map)
74JLn.png


Cold Air Damming (CAD)

(from weatherprediction.com)

Cold Air Damming occurs when a low-level cold air mass is topographically trapped on the east side of a mountain range. An area of high pressure at the surface will be positioned to the north of the region and the clockwise flow around the high means the low-level winds coming into the region will have an easterly component. These easterly winds will push up against the east side of the mountain range. Air moving up the mountain range ends up cooling at a greater rate than the dry-adiabatic lapse rate and this causes the upslope flow to slow down allowing the cold air to build up on the eastern slopes. When looking at a surface chart, a CAD setup will often be noted by a distinct “wedging” pattern of cool temperatures trying to push their way down the mountain range spine which can clearly be seen on the East Coast in the image below.

5idHRWwl.png


Blocking

(from weatherprediction.com)

Atmospheric blocking leads to a stagnation of weather patterns. As you are well aware, atmospheric patterns tend to repeat themselves. In the case of blocking, the same pattern repeats for several days to even weeks. This can lead to flooding, drought, above normal temperatures, below normal temperatures and other weather extremes. It is important to recognize a blocking pattern in its initial development. With this awareness, you will be able to forecast out to several days in advance with a high degree of accuracy.

Atmospheric blocking is best seen on upper air analysis and forecast charts. Blocking over large regions is most common with high-pressure since high pressure covers a large spatial area and tends to move slower than low pressure. In some instances, low pressure can also cause an atmospheric block. The five types of blocks that will be represented in this section are the Omega block, the Rex block, the Ring of Fire, Split flow and the Cut-off low. Each is detailed separately.


For more information on blocking see:


http://www.theweathe...n.com/blocking/

Phasing

This happens when branches of the jet stream combine or "phase" to create one large storm. The best example of a system phasing is the superstorm of 93. Here is a look of what the superstorm looked like on a weather model http://www.meteo.psu.edu/~fxg1/NARR/1993/us0313.php

 

 

Miller A - This is a track most in the SE favor for snow. A low forms in the gulf and goes along the FL pan handle and heads north just off the coasts of NC/SC. Often this allows cold air in and the spread of moisture across the SE.

JnKokNq.gif

 

Miller B -  This is a storm that generally favors those along and west of the Apps. A low will form in the gulf coast and track along the apps many times spawning another low going up the coast. Generally this keeps temps too warm for those south and east of the Apps. These also typically favor the north east section of the US.

WK0opYY.gif

 

 

Upper Level Low (ULL) - These type of storms can be tricky. As energy from the west moves east it essentially becomes stronger and tighter and begins to rotate. Think of it as a very tiny hurricane going across the SE. When an ULL is coming you want to be on the north west side of the low as this often has the best lift and dynamics for snow. ULLs can drop large amounts of snow in a short period of time as they can create their own cold core.

9CT2fCQ.gif

Soundings
(thanks to Queencitywx for this)


if you're new, you're going to hear alot about soundings from the models. I've found a snow sounding from an airport in Michigan to use as an example:

Date: 48 hour Eta valid 18Z THU 17 NOV 11
Station: KMBS
Latitude: 43.53
Longitude: -84.08
-------------------------------------------------------------------------------
LEV PRES HGHT TEMP DEWP RH DD WETB DIR SPD THETA THE-V THE-W THE-E W
	mb 	m 	C 	C	% C 	C deg knt K 	K 	K 	K	g/kg
-------------------------------------------------------------------------------
0 1000 144					 											
SFC 995 187 0.9 -7.2 55 8.1 -1.9 270 16 274.5 274.8 271.5 280.7 2.23
2 950 551 -3.8 -8.6 69 4.8 -5.4 272 21 273.3 273.6 270.6 279.1 2.09
3 900 975 -8.1 -9.5 89 1.4 -8.5 273 22 273.2 273.5 270.5 278.9 2.06
4 850 1415 -12.2 -13.2 92 1.0 -12.4 282 23 273.4 273.7 269.9 278.0 1.63
5 800 1875 -15.7 -19.1 75 3.4 -16.4 283 24 274.4 274.5 269.5 277.4 1.05
6 750 2358 -18.8 -25.1 57 6.3 -19.8 290 27 276.2 276.3 270.0 278.2 0.66
7 700 2871 -20.0 -30.1 40 10.1 -21.4 281 34 280.3 280.4 272.2 281.7 0.45
8 650 3416 -23.9 -34.6 37 10.7 -25.1 280 36 281.9 282.0 272.8 282.9 0.31
9 600 3995 -27.7 -37.1 40 9.4 -28.6 281 36 284.0 284.1 273.9 284.9 0.26
10 550 4615 -31.8 -43.0 32 11.2 -32.6 282 38 286.3 286.3 275.0 286.8 0.16
11 500 5282 -35.7 -47.9 28 12.2 -36.4 282 41 289.5 289.5 276.6 289.8 0.10
12 450 6009 -38.5 -57.9 11 19.5 -39.1 282 44 294.9 294.9 279.1 295.0 0.03
13 400 6813 -41.4 -69.3 3 27.9 -42.0 283 48 301.2 301.2 281.8 301.2 0.01
14 350 7712 -44.7 -71.3 4 26.5 -45.2 285 54 308.4 308.4 284.7 308.4 0.01
15 300 8737 -46.8 -69.5 6 22.6 -47.3 284 58 319.3 319.3 288.5 319.4 0.01
16 250 9942 -47.4					 276 60 335.6						
17 200 11414 -48.1					 268 66 356.6						
18 150 13301 -49.3					 265 52 385.1						
19 100 15940 -50.7					 255 44 429.8						
TRP 											0

If your sounding looks like that, I can almost guarantee what falls from the sky will be snow. Of course, there are nuances to reading this sounding like noticing if the column is significantly saturated that you'll learn with time. Text soundings can be found at this address: http://vortex.plymouth.edu/make.html

Please, no matter whatever you've learned elsewhere, believe this(http://68.226.77.253...FC/NAM_KCUB.txt) is a sounding. That is what's called model extraction data. While it can give you some of the specifics you get in a sounding, it is NOT a sounding.






Freezing Line - This refers to the 850mb line on a weather map.

AO - Arctic Oscillation http://nsidc.org/arc...scillation.html

NAO - North Atlantic Oscillation http://www.cpc.ncep....ledoc/nao.shtml

PNA - Pacif/North American Patter http://www.cpc.ncep....ledoc/pna.shtml


PDO - Pacific Decadal Oscillation

http://www.wrh.noaa....science/pdo.php


MJO - Madden Julian Oscillation http://en.wikipedia....ian_oscillation

The combination you want for the NAO, AO and PNA in the southeast during winter is:

- AO
+ PNA
- NAO




Board Slang

RN - Rain

SN - Snow

SN+ - Heavy Snow

IP -Ice Pellets AKA Sleet

ZR - Freezing Rain

QPF - Quantitative Precipitation Forecast. This basically means how much liquid should fall typically in a total for the storm but will also be broken down per hour increments.

SFC - Surface, usually in relation to surface temps. So someone might say, "sfc temps are too warm for snow accumulation".

Storm Mode: This happens when a large storm is approaching and the board is under heavy load from users. Remember in storm mode that the moderators are much stricter and non weather posts belong in the correct (banter) thread. If you're new and aren't sure of what you're posting your best option is to ask politely or simply do not post and attempt to learn.

MET - Meteorologist

MOD - Moderator who maintains no user gets out of hand

Admin - Generally handles any technical issues arising on the board, which usually happens during big storms

Bust - This refers to when a system underperforms. For instance the maps and professionals are calling for 5 inches and you get a dusting to one inch. This would be a bust

Jackpot - This typically refers to an area that receives the most snow during weather or a zone that a map has getting the most snow.

Weenie - This refers to someone prone to wild swings in emotion because of a lack of knowledge when it comes to weather. Weenies also often create totally baseless pseudo scientific reasons to back up their claims about future and present weather events.

Red Tagger - Meteorologist who posts on AmWx. You will know a poster is a verified MET when their username is red and they have "Meteorologist" in red under their name. See an example by clicking here

PBP - This stands for play-by-play which happens during the build up to big storms. Typically a few members of the board will monitor weather maps and give a description for those who do not understand the maps or do not have access to them.

Cliff Diving - (AKA jumping off the cliff AKA Lookout's cliff) Cliff diving is almost always referred to when a model or series of model runs downgrade a storm or make it non existent. Many times posters will "abandon ship" for the storm and become very negative about it.

Model Madness - This is usually used when the Euro/GFS/Canadian and other models are all at odds or swing wildly from one run to another with totally opposite scenarios.

Verbatim -This term is often used when explaining what the model/map literally shows. Many Meteorologist use their knowledge, experience, and past storms to make an educated guess as to what will actually happen sometimes going against what a model may show. Many however just read the maps "verbatim".

Analog- Often certain years are used to draw comparisons to the current winter season. For instance if 1878 was an El Nino (I didn't look this up) and this year is an El Nino and both had similar Summer/Fall seasons this can be used as an analog to help make a seasonal forecast.




For a list of links to help you learn more about weather see the following threads and posts 

 

http://www.americanwx.com/bb/index.php/topic/29651-weather-references-and-newbie-information/?p=2505699

http://www.americanw...ng-to-learn-wx/
OU Weather Roundup
UNISYS
Additional Links

 

 

CR's Handy List O' Links: 
 

Model Guidance:

 

PSU eWall (GFS, NAM, EURO, CMC, UKMET, DGEX, SREF): http://www.meteo.psu...fxg1/ewall.html

Earl Barker's Model Page (JMA):  http://wxcaster.com/models_main.htm

Instant Weather Maps:  http://www.instantweathermaps.com/

Canadian Model Center:  http://weather.gc.ca...st/index_e.html

European Model Center (Euro and Euro Ensemble Mean):  http://www.ecmwf.int/

NCEP (American Model Center):  http://mag.ncep.noaa.../appcontroller/

Rap Model: http://weather.rap.u...x.php?model=gfs

CFSv2:  http://origin.cpc.nc...wang/cfsv2fcst/

Unisys Weather:  http://weather.unisys.com/

HRRR Model:  http://rapidrefresh.noaa.gov/HRRR/
Twister Data:  http://www.twisterdata.com/

College of DuPage Weather Lab:  http://weather.cod.edu/forecast/

Weather Underground (Forecast maps and Obs):  http://www.wunderground.com/

 

CPC Data (Indexes and Outlooks)

 

Index Data (AO, NAO, PNA, MJO):  http://www.cpc.ncep....ndex_ensm.shtml

CPC Outlooks:  http://www.cpc.ncep....ts/predictions/

 

Other NWS Sites:

 

Weather Prediction Center:  http://www.hpc.ncep.noaa.gov/

Storm Prediction Center:  http://www.spc.noaa.gov/

National Hurricane Center:  http://www.nhc.noaa.gov/

NWS Home Page (find your WFO here):  http://www.weather.gov/

Hydrologic Prediction Service (Rainfall info):  http://www.water.weather.gov/precip/

Aviation Weather Center (Satellite Imagry):  http://aviationweath...adds/satellite/

 

Other Obs and Data Sites:

 

Cool Weather:  http://coolwx.com/

The Burkfit Warehouse (Meteogram Generator and GFS and NAM text output):  http://www.meteor.ia...en/bufkit/data/

MeteoStar:  http://wxweb.meteostar.com/

Wind Data:  http://hint.fm/wind/

 

Blogs/Commentary:

 

Hurricane Track:  http://hurricanetrack.com/

Matthew East (Charlotte area):  http://mattheweast.blogspot.com/

WxSouth (Robert Gamble):  www.wxsouth.com

WxRisk (DT):  www.wxrisk.com

Kirk Mellish (Atlatna area):  http://www.wsbradio....her-commentary/

Weather Bell (Joe Bastardi Saturday Summary -- free):  http://www.weatherbell.com/

WxJordan:  www.wxjordan.com

 

Miscellaneous Sites:

 

Solar Data:  http://www.solarham.net/

Airport Codes:  http://www.world-airport-codes.com/

Bear Paws (Tropical Weather page):  http://www.bearpawsw...ical/index.html

Weather Pick-up Lines:  http://www.weather.f...ckup_lines.html

Weather Learning Tools:  http://www.theweatherprediction.com/

  • Like 1
Link to comment
Share on other sites

Weenie - This refers to someone prone to wild swings in emotion because of no lack of knowledge when it comes to weather. Weenies also often create totally baseless pseudo scientific reasons to back up their claims about future and present weather events. :weenie:

I think you meant "...lack of knowledge..."

"No lack of knowledge" would be a double negative implying they do have this weather knowledge you speak of, upon which they base their opinions.

Link to comment
Share on other sites

This may be a little nit-picky, but instead of calling it the 850mb line, I would call it the 850mb zero degree isotherm/line. For someone that is truly new to weather map reading that may make a bit more sense since there is more than one isotherm on an 850mb temperature map.:snowman:

Link to comment
Share on other sites

I'd also add this:

if you're new, you're going to hear alot about soundings from the models. I've found a snow sounding from an airport in Michigan to use as an example:

Date: 48 hour Eta valid 18Z THU 17 NOV 11
Station: KMBS
Latitude:   43.53
Longitude: -84.08
-------------------------------------------------------------------------------
LEV PRES  HGHT  TEMP  DEWP  RH  DD   WETB DIR SPD THETA THE-V THE-W THE-E   W
    mb     m     C     C    %   C     C  deg knt   K     K     K     K    g/kg
-------------------------------------------------------------------------------
 0 1000   144                                                                 
SFC  995   187   0.9  -7.2  55  8.1  -1.9 270  16 274.5 274.8 271.5 280.7  2.23
 2  950   551  -3.8  -8.6  69  4.8  -5.4 272  21 273.3 273.6 270.6 279.1  2.09
 3  900   975  -8.1  -9.5  89  1.4  -8.5 273  22 273.2 273.5 270.5 278.9  2.06
 4  850  1415 -12.2 -13.2  92  1.0 -12.4 282  23 273.4 273.7 269.9 278.0  1.63
 5  800  1875 -15.7 -19.1  75  3.4 -16.4 283  24 274.4 274.5 269.5 277.4  1.05
 6  750  2358 -18.8 -25.1  57  6.3 -19.8 290  27 276.2 276.3 270.0 278.2  0.66
 7  700  2871 -20.0 -30.1  40 10.1 -21.4 281  34 280.3 280.4 272.2 281.7  0.45
 8  650  3416 -23.9 -34.6  37 10.7 -25.1 280  36 281.9 282.0 272.8 282.9  0.31
 9  600  3995 -27.7 -37.1  40  9.4 -28.6 281  36 284.0 284.1 273.9 284.9  0.26
10  550  4615 -31.8 -43.0  32 11.2 -32.6 282  38 286.3 286.3 275.0 286.8  0.16
11  500  5282 -35.7 -47.9  28 12.2 -36.4 282  41 289.5 289.5 276.6 289.8  0.10
12  450  6009 -38.5 -57.9  11 19.5 -39.1 282  44 294.9 294.9 279.1 295.0  0.03
13  400  6813 -41.4 -69.3   3 27.9 -42.0 283  48 301.2 301.2 281.8 301.2  0.01
14  350  7712 -44.7 -71.3   4 26.5 -45.2 285  54 308.4 308.4 284.7 308.4  0.01
15  300  8737 -46.8 -69.5   6 22.6 -47.3 284  58 319.3 319.3 288.5 319.4  0.01
16  250  9942 -47.4                      276  60 335.6                        
17  200 11414 -48.1                      268  66 356.6                        
18  150 13301 -49.3                      265  52 385.1                        
19  100 15940 -50.7                      255  44 429.8                        
TRP                                             0                         

If your sounding looks like that, I can almost guarantee what falls from the sky will be snow. Of course, there are nuances to reading this sounding like noticing if the column is significantly saturated that you'll learn with time. Text soundings can be found at this address: http://vortex.plymouth.edu/make.html

Please, no matter whatever you've learned elsewhere, believe this(http://68.226.77.253/text/NAMSFC/NAM_KCUB.txt) is a sounding. That is what's called model extraction data. While it can give you some of the specifics you get in a sounding, it is NOT a sounding.

Link to comment
Share on other sites

I think you meant "...lack of knowledge..."

"No lack of knowledge" would be a double negative implying they do have this weather knowledge you speak of, upon which they base their opinions.

Good catch, I was hoping no one would notice since I'm a weenie whistle.gif

Great link in the bottom of your post, Burger. Going a bit more into teleconnections which all the newcomers are seeing in the current discussions... This is what you want for snow and cold in the SE.

-AO

-NAO

+PNA

Its rare we get all 3 at one time...

Added including links to what they are

Other than Euro````` AKA Dr. No.

It looks great :)

Dang, I was racking my brain at work trying to remember it's nickname! Thanks! Those summers make me forget.

This may be a little nit-picky, but instead of calling it the 850mb line, I would call it the 850mb zero degree isotherm/line. For someone that is truly new to weather map reading that may make a bit more sense since there is more than one isotherm on an 850mb temperature map.:snowman:

Done, this is why you're the professional sir!

Link to comment
Share on other sites

Guess you are fired up for winter, Burger....great little tutorial you put together....now if they will only USE it.:thumbsup:

Mods...get this pinned....when things start to go in full swing, this will need to be seen by those new folks and not at the bottom of the list.

It will, great job Burger and QC, and everyone else who contributes! :thumbsup: We are going to have the winter forecasts up top for a couple more days, but I will tag this one, as well as the etiquette disco so we can pull them out as needed. Been a crazy day, and the night shaping up likewise. I will bust out the Mac tomorrow and do a couple write-ups for this, namely H5 maps (how to read, isohypses, vorticity, pos vs neg tilt troughs, etc) and another on how to use thickness plots to determine dominant precip type, that is unless someone beats me to it. ;)

Quick note: I like the idea of Burger putting all this in the first post, helps tremendously when new users click on the thread, it is right in front of them compared to the bottom of page 1, or a couple pages in. Again thank you!

Link to comment
Share on other sites

It will, great job Burger and QC, and everyone else who contributes! :thumbsup: We are going to have the winter forecasts up top for a couple more days, but I will tag this one, as well as the etiquette disco so we can pull them out as needed. Been a crazy day, and the night shaping up likewise. I will bust out the Mac tomorrow and do a couple write-ups for this, namely H5 maps (how to read, isohypses, vorticity, pos vs neg tilt troughs, etc) and another on how to use thickness plots to determine dominant precip type, that is unless someone beats me to it. ;)

Quick note: I like the idea of Burger putting all this in the first post, helps tremendously when new users click on the thread, it is right in front of them compared to the bottom of page 1, or a couple pages in. Again thank you!

Those write up's would be wonderful. I'm a little worried about it getting too long of a read for a newbie, but if you just want to put your posts down I'll link to them like I did with Jon's post.

Link to comment
Share on other sites

Guess you are fired up for winter, Burger....great little tutorial you put together....now if they will only USE it.:thumbsup:

Mods...get this pinned....when things start to go in full swing, this will need to be seen by those new folks and not at the bottom of the list.

Haha I guess I am. I'm taking the week off before Christmas and last year doing the same thing allowed me to do PBP at all hours of the night for the big Christmas Miracle of 2010. I got to thinking how so many new members showed up with tons of questions and since I was awaiting an email for work why not?

Link to comment
Share on other sites

Maybe I'm old school, but I still like Unisys Weather for a mix of layperson and met charts. Good jumping off point, especially in the Plains, but useful nationwide is the OU Met page som.ou.edu/wx and no I did not go to OU. ;)

If you do not have access to the European model www.meteoblue.com has an approximation I believe. It is a European weather site. Click on North America weather maps and go from there using the tabs at the top of the chart. This is anecdotal only, but I think the clouds/rain is loosely based on European output. Enjoy!

Link to comment
Share on other sites

Maybe I'm old school, but I still like Unisys Weather for a mix of layperson and met charts. Good jumping off point, especially in the Plains, but useful nationwide is the OU Met page som.ou.edu/wx and no I did not go to OU. ;)

If you do not have access to the European model www.meteoblue.com has an approximation I believe. It is a European weather site. Click on North America weather maps and go from there using the tabs at the top of the chart. This is anecdotal only, but I think the clouds/rain is loosely based on European output. Enjoy!

Added your links

Link to comment
Share on other sites

Maybe I'm old school, but I still like Unisys Weather for a mix of layperson and met charts. Good jumping off point, especially in the Plains, but useful nationwide is the OU Met page som.ou.edu/wx and no I did not go to OU. ;)

If you do not have access to the European model www.meteoblue.com has an approximation I believe. It is a European weather site. Click on North America weather maps and go from there using the tabs at the top of the chart. This is anecdotal only, but I think the clouds/rain is loosely based on European output. Enjoy!

Unisys is awesome...it's where I learned a lot from back in the day.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...