XRT HOWTO --- Read the La Palma One-Week Weather Forecast

T.Berger; 2008-Sep-25

Overview

Sometimes XRT is the lead Hinode instrument for collaborations with the La Palma (ground-based) Observatory. La Palma is heavily influenced by weather patterns, and this website gives a graphical one-week weather forecast, which may be useful to XRT-COs. However, the website is in German, so Tom Berger has provided the following explanation.

Tom Berger's explanation

From: Thomas Berger 
Date: September 24, 2008 7:09:35 PM EDT
To: "Davis, John M. (MSFC-VP62)" 
Subject: Weather condition page for La Palma

Here is the website showing weather conditions at La Palma for one
week from the current date:

http://91.121.93.17/pics/MU_La_Palma_avn.png

The maps are notated in German and require some explanation. Here's
an example from today:

In the top panel is a plot showing cloud cover for low, middle, and
high altitudes. If there is a white patch, then clouds are expected
at that altitude. Since the observatory is on the top of the mountain,
there can be low clouds and still be good observing conditions, but
middle or high cloud cover mean that observations will not be good.
Here, the 27th of September is the only day that looks promising
from a cloud cover standpoint; conversely, the 30th looks very bad.

In the middle panel, the colored contours show relative humidity
as a function of pressure altitude. Overlain on this plot are the
wind direction and strength arrows. For good observing conditions
at La Palma the upper level winds need to be from the North/North-East
and the humidity has to be very low. Wind from the West or the South
means the seeing will be poor. In this example the wind for the
entire week looks poor.

I don't know what the lower three panels show. Two of them are
labelled "schichtdicke" which means "layer thickness" - but I don't
know what layers they're referring to.

Here is a weather conditions page with satellite images for the
Canaries: 
http://www.iac.es/weather/tiempo.html 

Cheers,
Tom