Mother Nature is bringing active weather to central Indiana to end 2018. A weather system is moving up out of the Gulf of Mexico and will pass over central Indiana bringing with it rain, wind and warm air.
Central Indiana is already seeing the affects of the weather system late Sunday afternoon in the way of high-level clouds. Clouds will continue to increase overnight and stay around through much of Monday.
Rain will start to arrive in central Indiana early Monday morning. Rain will arrive in the Indianapolis metro, from the southwest, after 2 a.m.
The probability of rain increases to near 100% through the morning and early afternoon. There may be a brief lull in rain prior to a line of of heavy rain, and embedded thunderstorms, moves across central Indiana. At this time, I am not expecting much in the way of severe thunderstorms, however an isolated strong thunderstorm – capable of producing strong winds – is possible with the narrow line.
Rain will quickly come to an end Monday evening. I do think rain will be out of central Indiana by 10 p.m. Monday, so things should be dry as we enter 2019.
HEAVY RAIN POSSIBLE
All computer models suggest rainfall totals will be hefty through Monday night. I do think higher rain totals will be possible in southern Indiana, mainly along and south of State Road 46. However, all of the area has the potential of receiving 1″+ of rain.
Specifically in Indianapolis… A 29-computer model average suggests 1.15″ of rain falling through 8 p.m. Monday with a range from 0.86″ to 1.42″.
Flash Flood Guidance suggests flash flooding is possible if locales pick-up anywhere from 1.80″ to 2.40″ in a three hour period. For a 12-hour period, guidance suggests flash flooding possible if locales pick-up 2.30″ to 3.40″.
While flash flooding isn’t expected, streets prone to flooding may have periods of high water Monday afternoon/evening and river levels will likely rise. It is something we will keep an eye on throughout the day.
HANG ON TO YOUR HAT
Winds will start to increase mid-morning as winds shift from the southeast to the south. Sustained winds will be 12-28 mph while winds may gust 40+ mph at times during the afternoon and evening.
WIDE RANGE OF TEMPERATURES
Temperatures will remain in the lower to middle 30°s overnight. Temperatures should remain above freezing as rain moves in. There is a small chance along the leading edge of the rain, over northern portions of the viewing area (north of a line from Lafayette to Muncie), temperatures will be near freezing. If that is the case, there could be a brief (I stress brief) period of freezing rain/drizzle. That should not be an issue because temperatures will quickly rise and the precipitation will remain as rain.
We will be rising in to the middle 30°s to lower 40°s by 7 a.m. Monday.
Temperatures will be slowly rise until winds shift to the south. Once that happens, temperature will quickly jump in to the 50°s and lower 60°s. The greatest chance for 60° temperatures will be over the southern and southeastern part of the CBS4 viewing area.
There will likely be a sharp gradient between temperatures in the middle 50°s and middle/upper 40°s. I think that gradient will setup northeast to southwest somewhere between Indianapolis and Lafayette.