Vol. 12, Issue 3 (2023)

Author(s):
M Ratnam, D Sowmya, S Rajamani, A Subbarami Reddy and G Subbarao

Abstract:
In this article an attempt has been made to validate the month and season wise rainfall forecast issued to the 12 blocks of the Guntur district of South Coastal Andhra Pradesh for 2021-2022 by using skill score analysis. The skill score of the different blocks during south west monsoon (June-September) period indicated that the highest skill was observed with Krosuru block (86.9%) followed by Guntur block (86.2%) but lowest was noticed with Tenali (78.7%) followed by Macharla (81.2%) respectively. Percent skill of North East monsoon (October-December) indicated that the Macharla, Krosuru and Narsaraopet (95.6%) recorded highest skill score followed by Vinukonda and Piduguralla (93.4%) while lowest was observed in Tenali (83.4%) followed by Ponnuru block (83.6%) respectively. During entire monsoon period Krosuru (91.3%) followed by Narsaraopet (89.7%) and Vinukonda (88.9%) recorded highest skill score while lowest was noticed with Tenali block (81.1%) followed by Ponnuru block & Repalle block (84.4%) respectively and the percent deviation of forecasted rainfall from actual during south west monsoon was highest in Vinukoda block (192%), during north east monsoon was highest in Tenali block (-49%) and entre period was highest in Vinukonda block (109%). The skill score of entire district of Guntur during south west monsoon, north east monsoon and entire monsoon period indicated that 73.9%, 72.6% and 73.2 % respectively and that the percent departure of forecasted rain from actual of entire Guntur district indicated that -56%, -73% and -62% respectively.