WXMAP
This section is simply describing what the various lines, coloured areas are, what interval/units the contours, isobars, colour-filled areas use etc. The use, or meteorological significance of the fields are dealt with in a separate section ... HERE.
The WXMAP site is here.
IMPORTANT: I am not going to attempt a description of the full range of products, just the ones that might be most useful to those who want to 'dip-in' without much knowledge. Also, the fields presented below are not necessarily from the same situation, run-time etc. They are there simply to aid a quick identification for each product.
NOGAPS products (US Navy model)
| Example: | Brief description of parameters (etc.) on charts shown. |
MSLP, thickness & 12hr precipitation![]() | Gold lines: MSLP isobars. (units = hPa / interval = 4 hPa) Alternate blue & purple lines: thickness (500-1000 hPa) blue 528 & 552, purple 540 & 564 dekametres [dam]) Colour-fill regions: 12 hour precipitation rate (units=mm/12hr / interval=variable, see colour quadrant top/right of diagram) [ It's not entirely clear if this is the accumulated rainfall in the previous 12hr, or the instantaneous rate at some point in the last 12hr - my thoughts would be the former. ] |
300 hPa height & isotachs![]() | Green lines: 300 hPa contours. (units = metres / interval = 120 m) Black (thin) lines: isotachs of the 300 hPa wind. (units = knots [kn]/ interval = 10 kn) Wind arrows: conventional plots of wind-barbs at 300 hPa (units = kn) Colour-fill: strongest winds at this level (>= 50kn), according to scale at top/right of diagram. (Use to pick out approximate alignment of jet core). |
500 hPa height & relative vorticity![]() | White lines: 500 hPa contours. (units = metres / interval = 60 m). Colour-fill: Relative Vorticity (at 500 hPa .. roughly the level of non-divergence) (units=10-5s -1/ interval=2 : see colour quadrant at top-right of diagram - blue implies negative (non-developmental) values & red, orange positive (or developmental) values. |
850 hPa temperature, relative humidity & wind![]() | Purple/solid lines: 850 hPa temperatures above 0degC. (units=degC / interval=3 degC) Blue line: the Zero degree C isotherm at 850 hPa (labelled 'FR') Indigo/dash lines: 850 hPa temperatures below 0degC. (units=degC / interval=3 degC) Wind arrows: conventional plot for wind barbs at 850 hPa. Grey-fill: 850 hPa relative humidity. (units = % / interval = 20%: see grey-scale quadrant at top/right of diagram). |
Wave height & surface wind![]() | Wind arrows: conventional plots of the 'over-sea' wind-barbs (units = knots [kn]). Colour-fill: Wave height. (units=feet / interval = 3 ft: see colour chart at top/right of diagram - blue - low values, orange-to-red high values.) [ This would appear to be the 'total' wave height, i.e. wind + swell wave. ] |
AVN/MRF products (NCEP models)
(These output are in fact in identical format to that above for the NOGAPS model, which makes comparison easy. Only the wave / sea-surface wind field is not included in this set.)
| Example: | Brief description of parameters (etc.) on charts shown. |
MSLP, thickness & 12hr precipitation![]() | Gold lines: MSLP isobars. (units = hPa / interval = 4 hPa) Alternate blue & purple lines: thickness (500-1000 hPa) blue 528 & 552, purple 540 & 564 dekametres [dam]) Colour-fill regions: 12 hour precipitation rate (units=mm/12hr / interval=variable, see colour quadrant top/right of diagram) [ It's not entirely clear if this is the accumulated rainfall in the previous 12hr, or the instantaneous rate at some point in the last 12hr - my thoughts would be the former. ] |
300 hPa height & isotachs![]() | Green lines: 300 hPa contours. (units = metres / interval = 120 m) Black (thin) lines: isotachs of the 300 hPa wind. (units = knots [kn]/ interval=10 kn) Wind arrows: conventional plots of wind-barbs at 300 hPa (units = kn) Colour-fill: strongest winds at this level (>= 50kn), according to scale at top/right of diagram. (Use to pick out approximate alignment of jet core). |
500 hPa height & relative vorticity![]() | White lines: 500 hPa contours. (units = metres / interval = 60 m). Colour-fill: Relative Vorticity (at 500 hPa .. roughly the level of non-divergence) (units=10-5s -1 / interval=2 : see colour quadrant at top-right of diagram - blue implies negative (non-developmental) values & red, orange positive (or developmental) values. |
850 hPa temperature, relative humidity & wind![]() | Purple/solid lines: 850 hPa temperatures above 0degC. (units = degC / interval = 3 degC) Blue line: the Zero degree C isotherm at 850 hPa (labelled 'FR') Indigo/dash lines: 850 hPa temperatures below 0degC. (units = degC / interval = 3 degC) Wind arrows: conventional plot of wind-barbs at 850 hPa. Grey-fill: 850 hPa relative humidity. (units=% / interval=20%: see grey-scale quadrant at top/right of diagram). |





