Weather2 on Twitter Weather2 on Facebook Weather2 on YouTube Weather2 blog

Local Weather

Knarie Burn 14 Day Long Range Forecast

14 Day weather providing an extended long range forecast outlook for Knarie Burn

Dumfries and Galloway, United Kingdom

Long range weather outlook for Knarie Burn includes 14 day forecast summary:

Reviewing the forecast for Knarie Burn Over the next 14 days and the average daytime maximum temperature will be around 17°C, with a high for the two weeks of 21°C expected on the afternoon of Wednesday 22nd. The average minimum temperature will be 9°C, dipping to its lowest on the morning of Tuesday 21st at 6°C. Expect the coming 14 days to have some days seeing a little precipitation and some days with rain. It looks like Monday 13th will have the most precipitation with an accumulation of around 7.0mm. On the whole winds are likely to be moderate.

DayLocal TimeDirSpeed/
Gust
Temp/
Feels Like
HumidityPressureCloud AmountPrecip AmountWeather
Mon 13
Jul
18:00

WNW
WNW

12 / 15 mph 62 / 61°F 83% 1016 mb
Low level cloud: 39%
Mid level cloud: 23%
High level cloud: 18%
Most Significant Cloud Type: low
49%
Expect 0.02 In of precipitation over the past 3 hours.
0.02 In
21:00

WNW
WNW

8 / 17 mph 50 / 46°F 88% 1017 mb
Low level cloud: 0%
Mid level cloud: 0%
High level cloud: 94%
Most Significant Cloud Type: high
93%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
Tue 14
Jul
00:00

WNW
WNW

6 / 12 mph 47 / 44°F 92% 1018 mb
Low level cloud: 4%
Mid level cloud: 4%
High level cloud: 92%
Most Significant Cloud Type: medium
18%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
03:00

W
W

5 / 10 mph 46 / 43°F 93% 1017 mb
Low level cloud: 10%
Mid level cloud: 6%
High level cloud: 36%
Most Significant Cloud Type: low
16%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
06:00

W
W

7 / 11 mph 52 / 48°F 91% 1017 mb
Low level cloud: 27%
Mid level cloud: 16%
High level cloud: 35%
Most Significant Cloud Type: low
37%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
09:00

WNW
WNW

12 / 14 mph 61 / 59°F 77% 1016 mb
Low level cloud: 57%
Mid level cloud: 20%
High level cloud: 48%
Most Significant Cloud Type: low
70%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
12:00

WNW
WNW

11 / 13 mph 64 / 62°F 73% 1016 mb
Low level cloud: 31%
Mid level cloud: 21%
High level cloud: 32%
Most Significant Cloud Type: low
42%
Expect 0.01 In of precipitation over the past 3 hours.
0.01 In
15:00

W
W

13 / 16 mph 61 / 60°F 81% 1015 mb
Low level cloud: 82%
Mid level cloud: 43%
High level cloud: 85%
Most Significant Cloud Type: low
100%
Expect 0.01 In of precipitation over the past 3 hours.
0.01 In
18:00

W
W

9 / 11 mph 59 / 57°F 85% 1015 mb
Low level cloud: 67%
Mid level cloud: 87%
High level cloud: 32%
Most Significant Cloud Type: low
100%
Expect 0.01 In of precipitation over the past 3 hours.
0.01 In
21:00

WSW
WSW

6 / 9 mph 55 / 53°F 91% 1015 mb
Low level cloud: 62%
Mid level cloud: 48%
High level cloud: 1%
Most Significant Cloud Type: low
78%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
Wed 15
Jul
00:00

WSW
WSW

4 / 6 mph 53 / 53°F 94% 1015 mb
Low level cloud: 45%
Mid level cloud: 70%
High level cloud: 28%
Most Significant Cloud Type: low
72%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
03:00

WSW
WSW

2 / 4 mph 53 / 53°F 95% 1014 mb
Low level cloud: 62%
Mid level cloud: 95%
High level cloud: 15%
Most Significant Cloud Type: low
96%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
06:00

SW
SW

2 / 3 mph 54 / 55°F 94% 1015 mb
Low level cloud: 91%
Mid level cloud: 86%
High level cloud: 29%
Most Significant Cloud Type: low
100%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
09:00

SW
SW

3 / 4 mph 54 / 55°F 97% 1015 mb
Low level cloud: 89%
Mid level cloud: 96%
High level cloud: 16%
Most Significant Cloud Type: low
100%
Expect 0.04 In of precipitation over the past 3 hours.
0.04 In
12:00

WSW
WSW

5 / 6 mph 58 / 57°F 95% 1016 mb
Low level cloud: 91%
Mid level cloud: 73%
High level cloud: 17%
Most Significant Cloud Type: low
100%
Expect 0.01 In of precipitation over the past 3 hours.
0.01 In
15:00

W
W

9 / 10 mph 62 / 61°F 89% 1016 mb
Low level cloud: 98%
Mid level cloud: 91%
High level cloud: 63%
Most Significant Cloud Type: low
100%
Expect 0.01 In of precipitation over the past 3 hours.
0.01 In
18:00

SW
SW

5 / 6 mph 56 / 55°F 97% 1017 mb
Low level cloud: 93%
Mid level cloud: 100%
High level cloud: 33%
Most Significant Cloud Type: low
100%
Expect 0.05 In of precipitation over the past 3 hours.
0.05 In
21:00

WSW
WSW

4 / 6 mph 57 / 55°F 96% 1018 mb
Low level cloud: 46%
Mid level cloud: 46%
High level cloud: 6%
Most Significant Cloud Type: low
62%
Expect 0.01 In of precipitation over the past 3 hours.
0.01 In
Thu 16
Jul
00:00

W
W

5 / 8 mph 54 / 53°F 94% 1018 mb
Low level cloud: 63%
Mid level cloud: 12%
High level cloud: 61%
Most Significant Cloud Type: low
74%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
03:00

WSW
WSW

5 / 10 mph 50 / 48°F 95% 1018 mb
Low level cloud: 80%
Mid level cloud: 8%
High level cloud: 96%
Most Significant Cloud Type: low
93%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
06:00

WSW
WSW

4 / 5 mph 56 / 56°F 95% 1019 mb
Low level cloud: 80%
Mid level cloud: 9%
High level cloud: 100%
Most Significant Cloud Type: low
95%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
09:00

SW
SW

5 / 6 mph 61 / 60°F 92% 1020 mb
Low level cloud: 89%
Mid level cloud: 7%
High level cloud: 98%
Most Significant Cloud Type: low
100%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
12:00

WSW
WSW

6 / 7 mph 68 / 67°F 78% 1020 mb
Low level cloud: 85%
Mid level cloud: 42%
High level cloud: 32%
Most Significant Cloud Type: low
100%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
15:00

WSW
WSW

8 / 10 mph 64 / 64°F 90% 1020 mb
Low level cloud: 74%
Mid level cloud: 80%
High level cloud: 16%
Most Significant Cloud Type: low
100%
Expect 0.01 In of precipitation over the past 3 hours.
0.01 In
18:00

SW
SW

8 / 10 mph 68 / 66°F 89% 1020 mb
Low level cloud: 55%
Mid level cloud: 46%
High level cloud: 4%
Most Significant Cloud Type: low
71%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
21:00

SSW
SSW

4 / 9 mph 57 / 56°F 97% 1020 mb
Low level cloud: 71%
Mid level cloud: 22%
High level cloud: 1%
Most Significant Cloud Type: low
78%
Expect 0.01 In of precipitation over the past 3 hours.
0.01 In
Fri 17
Jul
00:00

S
S

4 / 6 mph 58 / 58°F 98% 1020 mb
Low level cloud: 84%
Mid level cloud: 17%
High level cloud: 10%
Most Significant Cloud Type: low
100%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
03:00

SSW
SSW

3 / 6 mph 57 / 58°F 98% 1019 mb
Low level cloud: 49%
Mid level cloud: 9%
High level cloud: 32%
Most Significant Cloud Type: low
100%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
06:00

SW
SW

6 / 11 mph 57 / 54°F 95% 1019 mb
Low level cloud: 51%
Mid level cloud: 46%
High level cloud: 13%
Most Significant Cloud Type: low
68%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
09:00

SSW
SSW

6 / 8 mph 59 / 58°F 94% 1020 mb
Low level cloud: 87%
Mid level cloud: 48%
High level cloud: 84%
Most Significant Cloud Type: low
100%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
12:00

SW
SW

9 / 10 mph 62 / 62°F 93% 1020 mb
Low level cloud: 93%
Mid level cloud: 66%
High level cloud: 100%
Most Significant Cloud Type: low
100%
Expect 0.01 In of precipitation over the past 3 hours.
0.01 In
15:00

SSW
SSW

8 / 9 mph 64 / 64°F 93% 1019 mb
Low level cloud: 90%
Mid level cloud: 77%
High level cloud: 100%
Most Significant Cloud Type: low
100%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
18:00

SSW
SSW

6 / 7 mph 63 / 62°F 97% 1019 mb
Low level cloud: 96%
Mid level cloud: 75%
High level cloud: 100%
Most Significant Cloud Type: low
100%
Expect 0.02 In of precipitation over the past 3 hours.
0.02 In
21:00

SSW
SSW

9 / 12 mph 60 / 60°F 98% 1018 mb
Low level cloud: 98%
Mid level cloud: 97%
High level cloud: 88%
Most Significant Cloud Type: low
100%
Expect 0.02 In of precipitation over the past 3 hours.
0.02 In
Sat 18
Jul
00:00

SSW
SSW

10 / 15 mph 59 / 57°F 98% 1017 mb
Low level cloud: 83%
Mid level cloud: 98%
High level cloud: 3%
Most Significant Cloud Type: low
100%
Expect 0.02 In of precipitation over the past 3 hours.
0.02 In
03:00

SSW
SSW

10 / 15 mph 58 / 56°F 98% 1015 mb
Low level cloud: 93%
Mid level cloud: 73%
High level cloud: 14%
Most Significant Cloud Type: low
100%
Expect 0.02 In of precipitation over the past 3 hours.
0.02 In
06:00

SSW
SSW

14 / 21 mph 58 / 55°F 97% 1014 mb
Low level cloud: 85%
Mid level cloud: 74%
High level cloud: 0%
Most Significant Cloud Type: low
100%
Expect 0.03 In of precipitation over the past 3 hours.
0.03 In
09:00

SW
SW

14 / 19 mph 57 / 54°F 98% 1014 mb
Low level cloud: 100%
Mid level cloud: 88%
High level cloud: 0%
Most Significant Cloud Type: low
100%
Expect 0.16 In of precipitation over the past 3 hours.
0.16 In
12:00

W
W

8 / 9 mph 60 / 59°F 89% 1015 mb
Low level cloud: 62%
Mid level cloud: 71%
High level cloud: 0%
Most Significant Cloud Type: low
87%
Expect 0.02 In of precipitation over the past 3 hours.
0.02 In
15:00

WNW
WNW

13 / 15 mph 64 / 62°F 66% 1015 mb
Low level cloud: 61%
Mid level cloud: 4%
High level cloud: 0%
Most Significant Cloud Type: low
62%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
18:00

W
W

8 / 12 mph 58 / 55°F 76% 1016 mb
Low level cloud: 32%
Mid level cloud: 16%
High level cloud: 0%
Most Significant Cloud Type: low
37%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
21:00

W
W

7 / 14 mph 48 / 44°F 83% 1018 mb
Low level cloud: 8%
Mid level cloud: 12%
High level cloud: 0%
Most Significant Cloud Type: low
12%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
Sun 19
Jul
00:00

WSW
WSW

4 / 8 mph 45 / 43°F 89% 1018 mb
Low level cloud: 11%
Mid level cloud: 9%
High level cloud: 0%
Most Significant Cloud Type: low
13%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
03:00

WSW
WSW

5 / 11 mph 43 / 40°F 94% 1018 mb
Low level cloud: 10%
Mid level cloud: 7%
High level cloud: 0%
Most Significant Cloud Type: low
12%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
06:00

WSW
WSW

7 / 9 mph 50 / 46°F 90% 1018 mb
Low level cloud: 19%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: low
34%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
09:00

W
W

12 / 14 mph 58 / 55°F 76% 1019 mb
Low level cloud: 37%
Mid level cloud: 26%
High level cloud: 0%
Most Significant Cloud Type: low
45%
Expect 0.01 In of precipitation over the past 3 hours.
0.01 In
12:00

W
W

14 / 18 mph 59 / 56°F 75% 1019 mb
Low level cloud: 21%
Mid level cloud: 24%
High level cloud: 0%
Most Significant Cloud Type: low
29%
Expect 0.03 In of precipitation over the past 3 hours.
0.03 In
15:00

W
W

15 / 18 mph 62 / 60°F 67% 1019 mb
Low level cloud: 24%
Mid level cloud: 44%
High level cloud: 32%
Most Significant Cloud Type: low
43%
Expect 0.02 In of precipitation over the past 3 hours.
0.02 In
18:00

WNW
WNW

13 / 18 mph 58 / 54°F 74% 1020 mb
Low level cloud: 5%
Mid level cloud: 7%
High level cloud: 8%
Most Significant Cloud Type: low
8%
Expect 0.01 In of precipitation over the past 3 hours.
0.01 In
21:00

W
W

10 / 20 mph 49 / 44°F 77% 1022 mb
Low level cloud: 0%
Mid level cloud: 3%
High level cloud: 0%
Most Significant Cloud Type: medium
3%
Expect 0.00 In of precipitation over the past 3 hours.
0.00 In
DayLocal TimeDirSpeed/
Gust
Temp/
Feels Like
HumidityPressureCloud AmountPrecip AmountWeather
Mon 20
Jul
00:00

SW
SW

3 / 6 mph 57 / 57°F 95% 1022 mb
Low level cloud: 52%
Mid level cloud: 46%
High level cloud: 3%
Most Significant Cloud Type: low
68%
0.01 In
06:00

S
S

3 / 4 mph 60 / 60°F 95% 1018 mb
Low level cloud: 51%
Mid level cloud: 10%
High level cloud: 20%
Most Significant Cloud Type: low
56%
0.00 In
12:00

W
W

6 / 8 mph 60 / 60°F 74% 1017 mb
Low level cloud: 51%
Mid level cloud: 32%
High level cloud: 6%
Most Significant Cloud Type: low
62%
0.02 In
18:00

NW
NW

11 / 13 mph 61 / 61°F 71% 1023 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 15%
Most Significant Cloud Type: medium
4%
0.00 In
Tue 21
Jul
00:00

NW
NW

6 / 13 mph 45 / 42°F 90% 1022 mb
Low level cloud: 9%
Mid level cloud: 3%
High level cloud: 8%
Most Significant Cloud Type: low
11%
0.00 In
06:00

W
W

3 / 4 mph 51 / 51°F 90% 1026 mb
Low level cloud: 30%
Mid level cloud: 17%
High level cloud: 98%
Most Significant Cloud Type: low
47%
0.00 In
12:00

NNW
NNW

6 / 6 mph 63 / 63°F 58% 1028 mb
Low level cloud: 33%
Mid level cloud: 0%
High level cloud: 21%
Most Significant Cloud Type: low
36%
0.00 In
18:00

WNW
WNW

9 / 11 mph 60 / 60°F 73% 1023 mb
Low level cloud: 53%
Mid level cloud: 5%
High level cloud: 45%
Most Significant Cloud Type: low
60%
0.01 In
Wed 22
Jul
00:00

NW
NW

4 / 9 mph 46 / 44°F 88% 1028 mb
Low level cloud: 0%
Mid level cloud: 4%
High level cloud: 21%
Most Significant Cloud Type: medium
5%
0.00 In
06:00

WSW
WSW

1 / 1 mph 52 / 52°F 84% 1023 mb
Low level cloud: 0%
Mid level cloud: 58%
High level cloud: 100%
Most Significant Cloud Type: medium
63%
0.00 In
12:00

WSW
WSW

4 / 5 mph 66 / 66°F 60% 1026 mb
Low level cloud: 2%
Mid level cloud: 32%
High level cloud: 8%
Most Significant Cloud Type: medium
37%
0.00 In
18:00

SSW
SSW

8 / 14 mph 56 / 55°F 92% 1017 mb
Low level cloud: 76%
Mid level cloud: 87%
High level cloud: 20%
Most Significant Cloud Type: low
100%
0.01 In
Thu 23
Jul
00:00

NNW
NNW

4 / 8 mph 51 / 50°F 90% 1024 mb
Low level cloud: 0%
Mid level cloud: 32%
High level cloud: 73%
Most Significant Cloud Type: medium
35%
0.00 In
06:00

SW
SW

9 / 16 mph 55 / 52°F 98% 1013 mb
Low level cloud: 90%
Mid level cloud: 73%
High level cloud: 82%
Most Significant Cloud Type: low
100%
0.07 In
12:00

SSW
SSW

4 / 5 mph 68 / 68°F 63% 1023 mb
Low level cloud: 0%
Mid level cloud: 44%
High level cloud: 32%
Most Significant Cloud Type: medium
45%
0.00 In
18:00

SW
SW

16 / 22 mph 58 / 55°F 97% 1009 mb
Low level cloud: 100%
Mid level cloud: 44%
High level cloud: 4%
Most Significant Cloud Type: low
100%
0.05 In
Fri 24
Jul
00:00

W
W

1 / 1 mph 52 / 52°F 89% 1021 mb
Low level cloud: 0%
Mid level cloud: 46%
High level cloud: 10%
Most Significant Cloud Type: medium
46%
0.00 In
06:00

WSW
WSW

11 / 17 mph 54 / 51°F 95% 1007 mb
Low level cloud: 92%
Mid level cloud: 43%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.01 In
12:00

SSW
SSW

6 / 8 mph 65 / 65°F 63% 1019 mb
Low level cloud: 0%
Mid level cloud: 45%
High level cloud: 100%
Most Significant Cloud Type: medium
48%
0.00 In
18:00

SSW
SSW

11 / 15 mph 57 / 55°F 98% 1003 mb
Low level cloud: 100%
Mid level cloud: 91%
High level cloud: 100%
Most Significant Cloud Type: low
100%
0.14 In
Sat 25
Jul
00:00

ENE
ENE

2 / 4 mph 53 / 54°F 82% 1016 mb
Low level cloud: 3%
Mid level cloud: 21%
High level cloud: 60%
Most Significant Cloud Type: medium
30%
0.00 In
06:00

W
W

3 / 4 mph 56 / 57°F 93% 1002 mb
Low level cloud: 13%
Mid level cloud: 98%
High level cloud: 10%
Most Significant Cloud Type: medium
100%
0.01 In
12:00

S
S

8 / 9 mph 67 / 67°F 78% 1013 mb
Low level cloud: 36%
Mid level cloud: 100%
High level cloud: 82%
Most Significant Cloud Type: low
81%
0.02 In
18:00

WNW
WNW

9 / 11 mph 60 / 60°F 72% 1004 mb
Low level cloud: 0%
Mid level cloud: 7%
High level cloud: 4%
Most Significant Cloud Type: medium
7%
0.01 In
Sun 26
Jul
00:00

N
N

1 / 1 mph 54 / 54°F 91% 1013 mb
Low level cloud: 0%
Mid level cloud: 37%
High level cloud: 0%
Most Significant Cloud Type: medium
36%
0.00 In
06:00

SSW
SSW

1 / 2 mph 53 / 53°F 92% 1005 mb
Low level cloud: 46%
Mid level cloud: 29%
High level cloud: 42%
Most Significant Cloud Type: low
60%
0.03 In
12:00

SW
SW

9 / 10 mph 68 / 68°F 70% 1014 mb
Low level cloud: 48%
Mid level cloud: 18%
High level cloud: 36%
Most Significant Cloud Type: low
58%
0.00 In
18:00

WNW
WNW

4 / 6 mph 63 / 64°F 72% 1005 mb
Low level cloud: 1%
Mid level cloud: 10%
High level cloud: 7%
Most Significant Cloud Type: medium
12%
0.04 In
Mon 27
Jul
00:00

WNW
WNW

3 / 6 mph 53 / 53°F 90% 1016 mb
Low level cloud: 12%
Mid level cloud: 28%
High level cloud: 32%
Most Significant Cloud Type: low
25%
0.00 In
06:00

NNE
NNE

5 / 7 mph 49 / 48°F 86% 1002 mb
Low level cloud: 0%
Mid level cloud: 13%
High level cloud: 100%
Most Significant Cloud Type: medium
17%
0.00 In
12:00

SSW
SSW

9 / 10 mph 62 / 62°F 88% 1017 mb
Low level cloud: 87%
Mid level cloud: 46%
High level cloud: 8%
Most Significant Cloud Type: low
100%
0.02 In
18:00

E
E

5 / 6 mph 58 / 57°F 89% 999 mb
Low level cloud: 36%
Mid level cloud: 46%
High level cloud: 0%
Most Significant Cloud Type: low
51%
0.04 In
Tue 28
Jul
00:00

S
S

5 / 8 mph 59 / 59°F 99% 1016 mb
Low level cloud: 99%
Mid level cloud: 95%
High level cloud: 0%
Most Significant Cloud Type: low
100%
0.09 In
06:00

NW
NW

6 / 8 mph 51 / 49°F 92% 1000 mb
Low level cloud: 8%
Mid level cloud: 100%
High level cloud: 17%
Most Significant Cloud Type: medium
100%
0.00 In
12:00

SW
SW

8 / 10 mph 64 / 64°F 95% 1014 mb
Low level cloud: 81%
Mid level cloud: 31%
High level cloud: 0%
Most Significant Cloud Type: low
92%
0.19 In
18:00

W
W

12 / 15 mph 58 / 55°F 75% 1007 mb
Low level cloud: 8%
Mid level cloud: 11%
High level cloud: 32%
Most Significant Cloud Type: low
15%
0.01 In

The day label given represents the local day relative to the local time for the location you are looking at.
(More Info)

Day

This time is corrected for local time zones and where possible for daylight saving times.
(More Info)

Local Time

The wind direction we use on this page is the direction the wind is coming from, given in a 16 point compass format.
(More Info)

Dir

This refers to the sustained average wind speed, normally averaged over a period of 10 minutes for up to 3 hrs.
(More Info)

Speed/
Gust

Temperature from our forecast perspective are fairly well defined, they are what we would expect to measure in a standard meteorological screen (in other words, shaded and well ventilated) at 2 metres above ground level.
(More Info)

Temp/
Feels Like

The relative humidity is the percent of saturation humidity, generally calculated in relation to saturated vapour density.
(More Info)

Humidity

The value given is a total predicted for the previous 3 hrs and includes the time of the forecast being looked at.
(More Info)

Precip Amount

The total amount of cloud as a percentage is derived from looking at cloud cover throughout the atmosphere and estimating how these combine when looked at from the ground.
(More Info)

Cloud Amount

Here we try to capture the feel of the weather as an image � it will never be perfect but is useful for a quick overview.
(More Info)

Weather

When we measure for forecast air pressure we are normally doing this relative to a certain height and most commonly relative to Mean Sea Level.
(More Info)

Pressure