A 34-year-old primigravida at 30 weeks' gestation presents with blood pressures persistently 150/98 mmHg on two occasions 4 hours apart. She has 2+ protein on dipstick, and a 24-hour urine collection shows 0.5 g protein. She has no severe features and normal blood tests. According to SOGC hypertensive disorders of pregnancy guideline, what is the most appropriate diagnosis?