Europe: Water deficits persist in Portugal; surpluses in Central, Eastern Europe

21 February

THE BIG PICTURE
The 12-month forecast ending October 2018 indicates exceptional water deficits in Finland, Estonia, Latvia, and along the Norwegian Sea coast and in central Sweden. Deficits are also forecast in Mediterranean Europe including the Iberian Peninsula, southern France, Italy, Corsica, Sardinia, Sicily, Malta, and Crete.

Surplus is forecast for Ireland, northern Germany, Poland, Lithuania, eastern Belarus, northern Ukraine, European Russia, and along many rivers. These conditions are expected to be exceptional in Ireland, northern Poland, and parts of European Russia, though both deficit and surplus conditions are forecast in Russia as transitions occur.

FORECAST BREAKDOWN
The 3-month composites (below) for the same 12-month time period show the evolving conditions.

Readily apparent in the map sequence below is the gradual transition in the region from predominantly surplus conditions to deficit. Note, however, that deficits have been and will continue to be the prevailing water condition on the Iberian Peninsula and in Finland.

From February through April exceptional water surplus will retreat except in Murmansk, Russia. However, widespread surpluses with a return period of 10 to 40 years will persist in European Russia and in parts of Central and Eastern Europe including Switzerland, Poland, eastern Belarus, and northern Ukraine. Surpluses will emerge in southern Norway and northern Sweden.

Intense deficits will shrink slightly but persist in Estonia, Latvia, central Finland, and central Sweden. Deficits in southern France and the Mediterranean are expected to moderate but severe deficits will continue in Portugal, Corsica, Sicily, and parts of Italy. Deficits will emerge in Albania and eastern Greece.

From May through July, much of Central and Eastern Europe will transition away from surplus to moderate deficit, joining southern Europe where deficits will be more intense, with severe conditions in Portugal, western Spain, southern France and along the Loire River, southern Italy, and Crete. Severe to exceptional deficits will continue to emerge in Estonia and Latvia and will spread in Finland. Moderate deficits will emerge in southern Sweden and Norway. Surpluses will shrink but continue in north-central Ukraine. Conditions of both deficit and surplus are forecast for European Russia as deficits emerge in areas of previous surplus.

The forecast for the remaining months – August through October 2018 – indicates moderate deficit throughout the region.

(It should be noted that forecast skill declines with longer lead times.)

IMPACTS
Heavy rains and melting snow have swelled rivers across Europe in recent weeks. After persistent rainfall during the wettest December through January period in 50 years, according to national meteorological service Meteo France, the River Seine peaked about four meters (13 feet) above its normal level, flooding the City of Lights in late January. Around 1500 people were evacuated from the greater Paris region, river tourism was halted, and commuter lines and expressways were closed, as was the lower level of the Louvre. Runoff from rainfall across northern France caused a second crest in early February.

Shortly after shipping had resumed on the Rhine River after flooding in January, traffic was briefly suspended following the collision of a ship with a rail bridge in the German city of Cologne. Later in the month, the medieval Swiss town of St-Ursanne flooded when the River Doubs broke its banks, and the Gotthard road tunnel in southern Switzerland was closed due to a mudslide. Heavy rains extended as far north as southwestern Finland, which experienced its worst winter flooding in over a decade, and flooding in Wales UK left motorists stranded and caused a landslide that deposited tons of debris on train tracks, halting rail traffic.

February rains extended eastward across Europe, causing flooding in Albania, Macedonia, and Kosovo.

According to one recent study, flood occurrence rate has increased by 44 percent in Europe since 1995.

In Moscow, record snowfall - the worst in 60 years - caused 850 flights to be canceled or rescheduled and downed 2,000 trees. The military was deployed to assist with snow removal.

More than half of Portugal, however, is experiencing “severe drought” as of late January, according to the country’s meteorological institute. January was the tenth consecutive month to experience below-normal precipitation, creating an uncertain outlook for this year’s maize harvest.

NOTE ON ADMINISTRATIVE BOUNDARIES
There are numerous regions around the world where country borders are contested. ISciences depicts country boundaries on these maps solely to provide some geographic context. The boundaries are nominal, not legal, descriptions of each entity. The use of these boundaries does not imply any judgement on the legal status of any territory, or any endorsement or acceptance of disputed boundaries on the part of ISciences or our data providers.