Southeast Arizona Climate Summary
Fall 2002-Winter 2003
January 10, 2003 – Weak to moderate El Nino conditions in the equatorial Pacific region continue to
persist though early January. These conditions are considerably less intense than those associated with
the 1997-98 El Nino that produced above normal winter precipitation across the southwest United
States. Weak to moderate El Nino conditions produce highly variable winter precipitation amounts. Early
season winter storms in November and December appeared to have been associated with a strong
southern branch jet stream across the southwest possibly enhanced by the El Nino conditions. A strong
and persistent southern jet stream is an important feature associated with strong El Nino conditions. Our
current weak-moderate El Nino has failed to induce a strong and persistent jet stream and storm track
across Arizona. This jet stream track may still develop this winter, but has been highly variable over the
last two months. (More information at http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/)
Southeast Arizona Palmer Drought Severity Index and Precip. Anomaly: 2001-02
6
4
PDSI/Precip (in.)
2
0
-2
-4
-6
2
v-0
No
2
t-0
Oc
2
p-0
Se
2
g-0
Au
2
l-0
Ju
02
nJu
-02
ay
M
2
r-0
Ap
02
arM
2
b-0
Fe
02
nJa
1
c-0
De
1
v-0
No
1
t-0
Oc
1
p-0
Se
1
g-0
Au
1
l-0
Ju
01
nJu
1
y-0
Ma
1
r-0
Ap
01
arM
1
b-0
Fe
01
nJa
Month
PDSI
Precip. Anomaly (in)
Monthly precipitation for climate division #7 (SE AZ) has been consistently below normal
every month since July of 2001. This has caused Palmer Drought Severity Index values to
reach extreme drought levels (note line with diamond symbols on graph).
THE UNIVERSITY OF
ARIZONA®
Southeast Arizona Climate Summary - Fall 2002
SPI values show that
short-term precipitation
amounts are slightly
below normal for SE AZ.
12-24 month periods prior
to Nov 2002 are still close
to 2 standard deviations
below normal, indicating
persistent, longer term
drought conditions.
Most locations across southeast Arizona
experienced above normal temperatures
and below normal precipitation for Nov.
2002. The Western Regional Climate
Center estimates that most locations
across SE AZ are at less than 50% of
normal for the early winter season of
10/1/02 – 1/1/03.
Location
Nov. 2002
Avg. Temp
(F)
Nov. Longterm Avg.
Temp (F)
Nov. 2002
Total
Precip(in.)
Nov. Longterm Avg.
Precip (in)
Willcox
52.4 F
50.3
0.27”
0.73”
Safford
54.4
52.1
0.19”
0.56”
Chiricahua
N.M.
52.1
50.5
0.30”
1.31”
Douglas
53.5
52.5
0.10”
0.74”
Tucson
61.4
59.2
0.23”
0.67”
(data from http://www.wrh.noaa.gov/tucson and http://wrcc.dri.edu)
The spring forecast from the Climate
Prediction Center shows above normal
precipitation for Feb-Mar-Apr. This
forecast appears to be based on regional
precipitation patterns that accompany
typical El Nino conditions. The current
02-03 El Nino has few similarities to past
strong El Nino events and may not
produce these forecasted above normal
precipitation patterns. El Nino related jet
stream patterns will have to quickly
redevelop for the remainder of this winter
to provide above normal precipitation
amounts.
Above Normal
Precip Forecast
From: http://www.cpc.noaa.gov/products/predictions/90day/lead01/p02.gif
Southeast Arizona Drought Summary – University of Arizona Space Grant Project – Questions contact: crimmins@u.arizona.edu