It was either Saudi Arabia or Iran broadcasting on 999 kHz. Both are common on the Arctic SDR. Spain and Italy also heard. The MWLIST is a good resource on what is on each frequency. Here is their list of Europe/Africa and Middle East for 999 kHz:
http://www.mwlist.org/mwlist_quick_and_easy.php?area=1&kHz=999
Thanks CADXER. Last few times I've been listening it's already past sunrise in Europe, but I have caught one of those stations in the past interfering with KOMO when I listen earlier.