Extreme Max Min Temperatures


Corn Growth Stage

Fig. 9.1 Temperatures during the corn growing season in the Po Valley, Italy.

Fig. 9.2

Temperature extremes in the Po Valley, Italy.

Although Figure 9.3 indicated that by March 15 rainfall was slightly above normal, a closer look tells a much different story. Over 200 mm of rain fell in the later half of December, shifting the cumulative curve up. Because soils in Rio Grande do Sul are sandy and unable to hold moisture well, hence the timing of rainfall is critical. Two extended dry periods in early 2004 proved disastrous to yields. Additional meteorological analysis hinted at this outcome. Figures 9.4, 9.5, and 9.6 show monthly rainfall totals (low in 2004), days between rainfall (above normal in 2004), and a soil moisture analysis showing a precipitous decline beginning in January. All three indicators provided clear warning of a poor crop. (Clearly, the 2005 crop was also affected by drought).

Another recently employed analytical method, the CPC MORPHing technique (CMORPH), makes use of satellite data to provide an estimate of rainfall to enhance station data. CMORPH can be used to provide indications when station data are lacking or, in the case shown in the Figure 9.7, missing due to technical difficulties. It provides an additional source of information that can support or even replace other sources of information.

tte importance of using multiple sources of weather information to assist meteorologists and economists at the WAOB was exemplified by a unique weather event in South Asia. During March 2006, an unseasonably strong mid-latitude storm system moved northeastward from the Arabian Sea into central and northern India, impacting India's maturing winter grains. Not only was the timing and location of the storm rare, but the storm intensity was also noteworthy. Satellite imagery showed a cloud pattern indicative of very heavy precipitation along with severe

Rio Grande do Sul, Brazil

Cumulative Daily Precipitation (mm)



Fig. 9.3 Cumulative rainfall for Rio Grande do Sul in southern Brazil.

1 WorW Aertrultura] Outlook Board US OA

WCJ U Joint AjrifuJUiril WeItkrr F »rilifv ^^^m

1 WorW Aertrultura] Outlook Board US OA

WCJ U Joint AjrifuJUiril WeItkrr F »rilifv ^^^m

9.4 Total precipitation from February 1-28 in Rio Grande do Sul.

Fig. 9.5 Average days between rain from February 1-28 in Rio Grande do Sul.

Rio Grande do Sul, Brazil

Soil Moisture (Warm Season Crops)

V\ ti\ J


Ä ä ä Ä o o ¿S z° I I i s Ä n Î 4 ÎÎ Î Î i I I s Ï

m ii^ —-.1* World Agricultural Outlook Board US OA WC! U Joint Agricultural Weather Facility _ _ ---■

Week {by ending date) Fig. 9.6 Soil moisture in Rio Grande do Sul.

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