Low pressure will lead to soaking rainfall across Spain and Portugal early in the week. Despite drier-than-normal conditions during the past few months, flooding will threaten parts of the region.
In contrast to northern Spain and Portugal where rainfall has been in abundance over the winter, southern areas have been drier than normal from December to March, worsening the ongoing drought conditions in parts of the region.
While the rain early this week will be beneficial in increasing water levels, heavy rain in some areas will lead to the threat for flooding.
The greatest risk for flooding will begin across Portugal and southern Spain on Monday as downpours move eastward from the Atlantic. Rain will fall in Porto, Lisbon and Seville most of the day and will be heavy at times.
AccuWeather Meteorologist Tyler Roys said "Generally, 25-50 mm (1-2 inches) of rain is expected over a large portion of Spain and Portugal." This rain will generally be beneficial in reducing drought conditions.
Roys warns "In a few areas, upwards of 100 mm (4 inches) of rain can fall which may lead to flooding in low lying and poor drainage areas."
The greatest concern for flooding will be from southern Spain, including areas in and around Seville, northeastward to Zaragoza. Another area of flooding will target northern Portugal.
Rain will fall much of the time in Madrid on Monday and Monday night, but the heaviest rain will fall to the south of the city. Despite this, it is possible that there is minor flooding in low lying areas. Travel delays are expected through the air and on the roads as rain reduces visibility and causes ponding on some roads.
This area of steady and heavy rain will move into eastern Spain from Monday night into Tuesday. Meanwhile, rain will lessen across western areas. This will be when areas from Albacete to Teruel and Zaragoza will have the greater risk for flooding.
Barcelona will escape the risk of flooding, and football fans will be happy to hear that most of the rain will be done before Barcelona hosts Atlético Madrid on Tuesday evening.
In addition to the heavy rainfall, Roys adds "This storm will bring heavy snow across the mountains where upwards of a meter (about 3 feet) of snow is expected to fall, especially in the Sierra Nevada." Snow levels are expected to be 1,500-2,000 meters (5,000-6,000 feet) and could fall even lower on Monday night into Tuesday.
Additional snowpack in the mountains will bring beneficial water during the summer as temperatures warm and snow melts.
Generally dry conditions will return to much of Spain and Portugal during the middle of the week. However, showers will wet areas along the northern Spain coast. There is not expected to be additional widespread rain through the end of the week.