unanticipated, unexpected, unforeseeable, unpredicted, unplanned, foreseeable, catastrophic, unavoidable, untoward, adverse, unpredictable, anticipated, unpreventable, cataclysmic, unbudgeted, unintended, untimely, inexplicable, inevitable, extraordinary, exogenous, technological, serendipitous, impending, geopolitical, fortuitous, insurmountable, unrelated, unimagined, remediable, unlooked, unexplainable, imponderable, sudden, unfortunate, extenuating, evitable, logistical, warrantable, unusual, explainable, surmountable, unfathomable, calamitous, unimaginable, avoidable, unscheduled, extenuating circumstances, abrupt, inadvertent, related, unfavorable, inherent, uncontrollable, undesired, unsuspected, irresolvable, freakish, due, improbable, undesirable, such, insolvable, myriad, unknowable, atypical, imminent, force majeure, subsequent, technical, unexplained, unspecified, contractual, monumental, miraculous, rh incompatibility, unlikely, unprepared, indeterminable, determinable, unprecedented, unknown, aforementioned, budgetary, certain, predictable, climatic, future, actual, significant, unpropitious, precipitious, delayed, accidental, immanent, unseen, governmental, additional, epochal, uncertain, extraneous, conceivable, unforseen, dire, expectable, likely, consequential, preventable

bad luck, booby trap, emergency, exigency, hang-up, hitch, misfortune, pinch, pitfall, ramification, repercussion, rub, snag, spur-of-the-moment, turn, turn of events, twist

out of the blue, unlooked-for