The Transportation Security Administration says this week could be one of the busiest holiday travel periods in its history. Travelers are already filling LaGuardia Airport before sunrise as the Thanksgiving travel rush gets underway. WHAT'S NEW: Mild with rain on Wednesday changes to colder, windy and dry for Thanksgiving. WHAT'S NEXT: Be prepare for rain towards the evening rush. Today: A cloudy sky with showers developing between 3 p.m. - 6 p.m. High near 57. South wind 10 to 20 mph. Sunset: 4:27pm

Tonight: STORM WATCH. Cloudy with periods of rain. Some moderate to heavy rain from 7 p.m. to 1 a.m. Chance of thunderstorms. Lows around 52.

Wednesday: Chance of a morning thunderstorm with a quick period of heavy rain possible. Cloudy sky with on and off rain. Highs near 60 Southwest wind 10 to 20 mph.

Wednesday Night: A cloudy sky with a few scattered showers through midnight. Clearing skies overnight with gusty winds developing. Low around 39. West wind 10 to 20 mph.

Thanksgiving Day: Mostly sunny with a high near 48. Windy, west-northwest winds 10 to 20 mph gusting to 35 mph. Wind chills in the 30s.

Thursday Night: Mostly clear with a low around 31. Cold. Winds Chills in the low- to mid-20s. Friday: Mostly sunny with a high near 46. Breezy and cold. Wind chills in the 20s. Friday Night: Mostly clear with a low around 31. Saturday: Sunny with a high near 44. Saturday Night: Mostly cloudy with a low around 32. Sunday: Mostly cloudy, chance of late day showers. High near 51.