DROUGHT INDICATORS - August 1998

AS of the end of July, the division 7 PDSI had been below -2.00 for two consecutive months. The division 3 PDSI had been below -2.0 for one month. Strictly going by the drought plan triggering mechanisms, this places division 7 in the Warning category, and division 3 in the Alert category. Divisions 1 and 2, which had been placed in the Advisory status, had returned to "normal", although on the dry side.

Weekly Trends of PDSI: The most recent weekly PDSI (August 8) showed a PDSI of -2.2 in division 3, and a PDSI of -3.3 in division 7. The only other division with an index of below zero was division 1, (-0.6).

Division 3 had been on a slight "improving" trend, although July precipitation totals suggest that most of the southern portion of division 3 remains extremely dry. Division 7 is not improving, and the weekly PDSI suggests the severe drought that has been over Texas now extends into southeast New Mexico.

Forecasts: The Climate Prediction Center 13-month forecasts continue to suggest the strong likelihood of below normal precipitation over New Mexico. Highest confidence is for the coming winter with much less confidence for the remainder of the summer and autumn. Discussions of the forecast have been centered around expectations related to La Nina, but with La Nina only in the development phase, and not well established, the forecast community may have jumped the gun on this, especially for the summer period. The lag between development of La Nina and "weather" is unclear and each case unique. A new 13-month forecast will be issued August 13.

Major reservoir capacities have decreased from last month. The decrease is largely due to the increased irrigation demands from the various basins and reservoirs.

The Weekly Ag. Update is reporting cattle and sheep in mostly fair condition. Soil moisture conditions for the state is 21% very short, 31% short, 45% adequate, 3% surplus. Most of the dry soil moisture is reported to be in the northeast and southeast parts of the state.