The Well of Tears by Cecilia Dart-Thornton

After Jewel and Eoin have fled from their native Slievmordhu to the kingdom of Narngalis, they tread a perilous path which ultimately leaves Eoin in the hands of the deadly unseelie wights. With nowhere else to go Jewel finds refuge amongst the plateau-dwellers at High Darioneth. Teeming with siofra, trows and other eldritch wights, their land is under the tight rule of the weathermasters and Storm Lord Avalloc, who have the power to tame and summon the winds... When Jewel learns that the legendary Dome of Strang is no longer guarded, she decides to continue her journey to Orielthir to unravel the mystery of the hidden stronghold and with it the truth about her father's legacy. Jewel's discoveries lead her on an unexpected quest, accompanied by a handsome young weathermaster who has secretly fallen in love with her. Together they encounter marvels and misfortunes and discover that the key to all their riddles ultimately lies with the extraordinary Well of Tears...