Colorado Monthly meterology 1995- 1997

These is a group of R data sets for monthly min/max temperatures and precipitation over the period 1895-1997. It is created from the more extensive US data record described in Observed monthly precipitation, min and max temperatures for the coterminous US 1895-1997

Data domain:

A rectagular lon/lat region [-109.5,-101]x [36.5,41.5] larger than the boundary of Colorado comprises approximately 400 stations. Although there are additional stations reported in this domain stations that only report preicipitation or only report temperatures have been excluded. In addition stations that have mismatches between locations and elevations from the two meta data files have also been excluded. The net result is 367 stations that have colocated temperatures an precipitation.

Processing script:

The complete details of how the orignal tar files were processed to obtain the R data sets is in CO.process.R . Much of this R code is an elabortion of the examples in the full US data homepage.

R data object

Grab the binary R data object RData.COmonthly.met

In R:

This workspace will contain the objects:
 "CO.elev"     ""       "CO.loc"      "CO.ppt"      
"CO.tmax" "CO.tmin"     "get.station" are alphanumeric station id codes. CO.elev are station elevations in meters. CO.loc are station locations as a 2 column matrix of longitude /latitude.

The following data matrices have dimension 1236X367 where the columns index stations and the rows index time.
CO.ppt monthly total precipitation in millimeters. CO.tmin monthly average of the daily minimum temperature in tenths of a degree C. CO.tmax monthly average of the daily maxmium temperature in tenths of a degree C.

Quick example using the fields library

library( fields)
ppt.season <- tmax.season <- tmin.season <- matrix( NA, ncol=ncol(CO.tmin), nrow=12)

M <- ncol(CO.tmin)
months <- rep( 1:12,103)

for( kk in 1:M){
# loop over stations find means and note conversion to English 
# units!
tmin.season[,kk]<-stats(CO.tmin[,kk], by=months)[2,]*.1*(9/5) +32
tmax.season[,kk]<-stats(CO.tmax[,kk], by=months)[2,]*.1*(9/5) +32
ppt.season[,kk]<-stats(CO.ppt[,kk], by=months)[2,]/10*2.54 
cat( kk, " ")
Now plot up monthly averages for July and December coding values at station locations using a color bar.
set.panel( 2,3)

image.plot(as.image( c(tmin.season[7,]) , x= CO.loc)) 
title("July mean Tmin (F)")
image.plot(as.image( c(tmax.season[7,]), x= CO.loc)) 
title("July mean Tmax (F)")
image.plot(as.image( c(ppt.season[7,]), x= CO.loc)) 
title("July mean precip (inches)")

image.plot(as.image( c(tmin.season[12,]) , x= CO.loc)) 
title("Dec mean Tmin (F)")
image.plot(as.image( c(tmax.season[12,]), x= CO.loc)) 
title("Dec mean Tmax (F)")
image.plot(as.image( c(ppt.season[12,]), x= CO.loc)) 
title("Dec mean precip (inches)")