India Meteorological Department (IMD) had issued all necessary severe weather warnings through its office in Thiruvananthapuram. As per the regular practice, warnings are uploaded in the local website (www.imdtvm.gov.in) every day. District wise rainfall forecast along with warnings are also uploaded and updated thrice daily in the website. Nowcasts for next 3 hours are also issued through SMS to SDMA, SEOC, District collectors using Doppler Weather Radar Data. Weather Forecasts for 5 days and outlook for subsequent two days, which also include heavy rainfall warning and wind warning, are sent through e-mail to Chief Secretary, Addl. Chief Secretary (Revenue & Disaster Management), SDMA, Navy, Special Marine enforcement, Print and electronic media.
High level officials of Kerala Government were briefed in a meeting convened by Chief Minister on 9th August about the strong monsoon conditions with heavy rainfall activity. Also the Addl. Chief Secretary (Revenue & Disaster Management) was briefed orally over phone on all occasions. Member Secretary, SDMA was briefed on 10th August. District Collectors of Kollam and Thiruvananthapuram were briefed on 14th August. Briefings were sent to media also during this period.
Extended range forecasts (issued 2 weeks in advance) issued from Delhi
In a press release issued on 2nd August 2018, it was indicated that the rainfall over ‘extreme south peninsula’ shall be above normal during 9th – 15th August 2018. In the subsequent press release issued on 9th August also, the same statement was repeated, along with a date-wise indication of likely widespread rainfall with isolated heavy rainfall over Kerala re-starting from 13th August. The above press releases had been communicated to the Chief Secretaries of all the States via E-Mail and also posted on the IMD website.
Short & medium-range forecasts (5 days in advance) issued from IMD Thiruvananthapuram
Orange alerts (prepare for action) were issued w.e.f 6th applicable for 8th August onwards and Red alert (for action) were issued w.e.f 9th August. Further, for showing the severity of rainfall intensity expected, heavy (7-11 cm in 24 hrs) to very heavy (12-20 cm in 24 hrs) rainfall warning for Kerala state was issued w.e.f 10th August for 14th August with Orange Alert to
Idukki and Alappuzha, Red alert to Wayanad district. On 11th heavy to very heavy rainfall warning extended for 15th August also with an orange alert to Idukki and Wayanad districts.
On 12th August Red alert was issued for Idukki effective from 14th August. On 14th August, again heavy to very heavy rainfall warning was issued for 14th and 15th with red alert and orange alerts for most of the districts. On 15th, extremely heavy (>20 cm in 24 hrs) rainfall warning was issued for Kerala state with a red alert to all districts for 16th August and red for 7 districts and orange for the remaining 7 districts for 17th August. It may be noted that the Red alert is the highest alert for issuing heavy rainfall warning and no other alerting criteria than this is adopted by IMD.
The weather Bulletins issued from Delhi office also carried warnings for Kerala in ‘Orange’ and ‘Red’ colours about 2-3 days in advance of the event, advising the Disaster managers to be alert and initiate action respectively.