Much colder temperatures will arrive later today. The first map below shows an exceptionally deep 500mb trough that is forecast across the Gulf Coast States this morning. The gray area over southern Louisiana reflects a forecast of 500mb heights which are 5 standard deviations below the mean! With such a deep trough in place, highs will struggle to reach 50 for today and Thursday.
This second map shows deep low pressure around 990mb that is forecast to move north across Ohio early Thursday. In fact...one of the models predicts low pressure to bottom out near 982mb over Detroit late Thursday! A strong pressure gradient around this low will produce breezy to windy conditions beginning late tonight through Thursday.