A large storm system is moving across the United States. Ahead of the system Blizzard Warnings, Winter Storm Warnings, Winter Weather Advisories have been hoisted by the National Weather Service for the northern side of the storm. On the southern side, Flash Flood Watches, a Tornado Watch and Severe Thunderstorm Watch is in effect Wednesday evening.
The system has already started to impact central Indiana by initially sending mid to high level clouds over the state late today.
I think the biggest impact from the storm over the next 48 hours will be winds. Winds will begin to increase early Thursday morning and continue ramping up through the evening. Sustained winds will be 20-30 mph and wind gusts could reach 45-50 mph in some locales. Winds will begin to subside mid-morning Friday.
Sorry snow lovers, we are only expecting rain from this weather system. Rain should begin to arrive in to central Indiana after 8am Thursday and continue throughout the day. I think rain arrives in the Indianapolis metro after 10am. Within the bands of rain, a few embedded thunderstorms will be possible. However, severe thunderstorms are not expected Thursday and Friday.
Rain may be heavy at times, especially Thursday. A 29-computer model average suggests 0.85″ of rain through 8pm Friday in Indianapolis.
Temperatures will be slow to warm through the day. Factor in the wind and wind chill values will be in the 20°s and low 30°s through early afternoon.
By late afternoon temperatures should begin to rise in to the 50°s as winds shift out of the south. The temperature should keep climbing through the evening.
Cold air will be slow to arrive behind a succession of cold fronts Friday. The first front will turn winds out of the west. The second will turn winds out of the northwest. That is when you will notice temperatures beginning to drop.
Right now the weekend looks cooler but temperatures will continue to remain above normal. We will likely end December on a streak of 20 consecutive days above normal. There are hints of colder air arriving for the beginning of 2019, but nothing like the start to 2018 when temperatures dropped as low as -12° on January 2.