News - Blogs - How does low pressure and high pressure impact weather

How does low pressure and high pressure impact weather?
Published: 9/21/2011 7:00 AM
Last Modified: 9/20/2011 5:06 PM

In addition to confusion over the "H" and "L" symbols, there is another in this map that might draw some blanks: The purple line connected to the blue cold front and red warm front lines is an occluded front, indicating that the low pressure is in the process of weakening. An alternating red and blue line is a stationary front, indicating that the front is stretched across the area but is not moving. This NOAA map was released at about 4:30 p.m. Tuesday.

A local weather station once donated a floppy disc with weather games to our classroom (our classroom computer then was an Apple II).

I'd decorate weather maps with the rain clouds, the cloudsout with the rain, tons of sun and snow... and then, try to decide what to do with the "H" and "L" symbols.

What do those have to do with anything weather-related?

If you are still trying to find a clear answer on this question too, Tulsa National Weather Service meteorologist Karen Hatfield has the answers!

First, low pressure:

"Basically, if low pressure is approaching, it usually means unsettled weather or a change in the weather pattern," Hatfield said. "Low pressure systems typically bring fronts through the area, which can lead to rain, thunderstorms, winter precipitation.

"Low pressure systems can also often lead to windy days, which can increase the fire danger during drought conditions like the area is having now."

In extreme low pressure situations, Hatfield said a hurricane can happen, along with the severe weather that accompanies it.

Second, high pressure:

"Surface high pressure is associated with quiet and cool weather," Hatfield said. "Surface high pressure normally settles over a region after a cold frontal passage.

"When the center of the high is over the area, winds are very light, skies are usually clear, and therefore, the coolest nighttime temperatures will happen in this case."

In a nutshell, Hatfield said low pressure approaching means weather is unsettled. High pressure approaching means the unsettled weather is behind... for a couple days.

Yes, my classmates and I ended making smiley faces out of the weather symbols eventually, not weather reports, but I'd like think we learned something about meteorology along the way.

--Althea Peterson

Reader Comments

Show: Newest First

Learn About Our Comment Policy

To post comments on tulsaworld.com, you must be an active Tulsa World print or digital subscriber and signed into your account.

To sign in to your account, go to tulsaworld.com/signin.
To activate your print subscription for unlimited digital access and to post comments, go to tulsaworld.com/activate.
To purchase a subscription, go to tulsaworld.com/subscribe.

Almanac

Jan	Feb	Mar	Apr	May	Jun
Jul	Aug	Sep	Oct	Nov	Dec

	Temperature		Precipitation
Date	High Temp	Low Temp	Total	Month to date	Historical average
1	44°	16°	0	0.00	0.05
2	59°	24°	0	0.00	0.11
3	57°	33°	0	0.00	0.16
4	68°	37°	Trace	0.00	0.21
5	69°	29°	0	0.00	0.26
6	66°	33°	0	0.00	0.32
7	59°	38°	0.05	0.05	0.38
8	51°	34°	0	0.05	0.44
9	44°	36°	0.01	0.06	0.51
10	62°	37°	0.07	0.13	0.57
11	54°	28°	0	0.13	0.64
12	44°	30°	0.25	0.38	0.70
13	55°	40°	0.01	0.39	0.76
14	°	°			0.83
15	°	°			0.89
16	°	°			0.95
17	°	°			1.02
18	°	°			1.09
19	°	°			1.16
20	°	°			1.23
21	°	°			1.31
22	°	°			1.38
23	°	°			1.46
24	°	°			1.53
25	°	°			1.61
26	°	°			1.69
27	°	°			1.77
28	°	°			1.85

TEMPERATURE

RAINFALL

SNOWFALL

Weather World

Follow Jerry Wofford on Twitter for updates during severe weather conditions.

Tulsa weather milestones of 2013 (as of Feb. 12)

Highest temperature: 70 on Jan. 11 (Record: 115 on Aug. 15, 1936)
Lowest temperature: 15 on Jan. 16 (Record: Minus-16 on Jan. 22, 1930)
Hottest month (average): 40.5 degrees in January (Record: 91.7 degrees on July 1980)
Coldest month (average): 40. 5 degrees in January (Record: 21.7 in January 1918)
Most snowfall (day): 0.1 of an inch on Feb. 12(Record: 13.2 inches on Feb. 1, 2011)
Most snowfall (month): 0.1 of an inch in February(Record: 22.5 inches in February 2011)
Most rainfall (day): 0.91 of an inch on Jan. 29 (Record: 9.27 inches on May 26-27, 1984)
Most rainfall (month): 1.54 of an inch in January (Record: 18.18 inches on September 1971)
Highest wind speed: 30 mph on Jan. 30
Previous day with any rain: Feb. 12
Previous day with 1 inch or more of rain: Oct. 17, 2012
Previous day with any snow: Feb. 12
Previous day with freezing temperatures: Feb. 12
Read regular updates on Oklahoma's unpredictable weather and learn more about meteorology from the Tulsa office of the National Weather Service.

>> Visit the main weather page
>> Send us your weather photos
>> Meet the forecasters

Contributors
Staff Writer Althea Peterson started writing for the Tulsa World in March 2007 after previous stops at the Norman Transcript in 2006 and the Oklahoma Gazette in 2005. She followed her older brother from rural Wisconsin (with a public school that never seemed to call snow days) to the University of Oklahoma, but did not follow his pursuit to study meteorology. However, she tries to find as many opportunities to report on the weather as possible.

Staff Writer Jerry Wofford came to the Tulsa World in 2010 from The Manhattan Mercury in Manhattan, Kan. Originally from western Arkansas and a graduate of the University of Oklahoma, Jerry has lived in Tornado Alley his entire life and is one of those people who goes outside when the sirens go off.

Subscribe to this blog

Temperature
High Temp:	(Example: 45)
Low Temp:	(Example: 45)
Temperature Date:	(Example: 1/1/2011)

Precipitation
Total:	(Example: '.01)
Month to date:	(Example: '.01)
Normal month to date:	(Example: '.01)

2/2013	1/2013	12/2012	11/2012	10/2012	9/2012
8/2012	7/2012	6/2012	5/2012	4/2012	3/2012
2/2012	1/2012	12/2011	11/2011	10/2011	9/2011
8/2011	7/2011	6/2011

Your bookmark will appear on your Profile page. Please give it a title, and short description so that visitors to your page will understand where the bookmark leads.
Bookmark Title :

Bookmark Text :