In October of 2017 Tropical Storm/Hurricane Nate provided a perfect example of how a cyclonic low pressure system in the Caribbean could cause massive rainfall and flooding in the central mountains and on Costa Rica’s Pacific side. (see road closures)
The Caribbean coast ends up in a “rain shadow” since most of the moisture has been driven out of the air by the time it flows down the eastern slope of the central mountains. The Caribbean side was not dry but escaped the brunt of the rainfall.
The Waze App has some live info on closures. However, there is no data for some large segments of the roads listed below because there are no cars on them transmitting data.
Although the update below includes the status of major roads impacted as of October 10th the list below is NOT comprehensive. There are many other minor closures. It may be several days to several weeks before some of the roads reopen as the structural damage is still being assessed but in many cases entire bridges or sections of road are completely gone.
UPDATE OCT 16, 2017
The PanAmerican Highway remains closed on three major sections
1) Hwy 1 closed west of San Ramon at Cambronero – between San Jose and the Pacific coast – alternate route is Hwy 27 to Orotina then north on 23 and 1 or south on 34
2) Hwy 2 closed south of Cartago all the way to San Isidro – alternate route is Hwy 27 to Orotina then south on 34
3) Hwy 2 closed from Neily to the Panama border – no reasonable alternative
Other closed routes that may impact tourists
909 – near Hatillo – this is located about 25 km east of Tamarindo but impacts local traffic only. It does not impact traffic between the beaches and Hwy 21 (the Nicoya road).
130 – between Alajuela and Poas – alternate route 126 via Carrizal
243 – between San Isidro El General and Dominical – alternate route southeast on Hwy 2 from San Isidro to Palmar (this section is open) then northwest on 34 to Domincal
145 – Tilaran to Monteverde – this is the normal route from Arenal Volcano to Monteverde. The alternate route is to head west from Tilaran to Canas then south on Hwy 1 (this section is open) to Sardinal then north on 145 to Santa Elena/Monteverde
Other updates on road conditions
PDF map with details of initially impacted roads from Costa Rican Highway Department (CONAVI) (many of these have been repaired and reopened – see below).
As mentioned previously the Waze App also has live road information
Upcoming Weather the Second Half of October
October is normally the rainiest month of the year in the central mountains and on the Pacific coast. That pattern will likely continue but may cause more landslides, road and bridge outages than normal because the ground is hyper saturated from Nate.
Upcoming weather is predicted to be milder with seasonal rainfall but no major storms. All of the data I’ve seen focus on Ophelia and LO-17 low pressure systems which are still far to the east but very far north of Costa Rica and predicted to stay up north.
The only new systems on the radar are in the neighborhood of the Bahamas.