SEVERE WEATHER OUTLOOK
A line of strong to severe storms will gather strength and move east during the overnight hours out of Illinois. Late afternoon heating in Central Indiana with a break in the clouds has allowed the air mass to “recover” or begin to destabilize and prime for a new round of storms. The atmosphere is recovering from the cooling effect of the early day rainfall. With afternoon heating underway, the more unstable the air, the better chance of severe storms to develop.
Several hours of dry time will support severe storms late Friday as a night-time jet stream aids in thunderstorm development in Illinois. The timing of theses storms looks to reach the Illinois and Indiana state lines around 2 a.m. It is possible that a severe watch box could be issued while you sleep. We are timing the leading edge of these storm into the city around 3 a.m. but this will be monitored.
Damaging wind gusts and very heavy rain are likely with the storms through Saturday morning.
HEAVY RAIN AFTER THE STRONGER STORMS
The storms will race east through 5 to 6 a.m. Saturday but moderate to heavy rainfall is likely to continue into mid-morning Saturday. There is concern that localized flooding will occur as storms use the very moist air to produce heavy downpours for several hours. Be prepared for flooding/standing and pounding water early Saturday. Rainfall estimated off six machines places 2.02″ of rain down for the city. This is an average and with thunderstorms rolling through, the very moist air locally higher amounts of 4″ plus are possible.
From the National Weather Service’s GFS model – more than 5″ of rain possible next two weeks – that’s 250 percent the normal rainfall – stay tuned.
SPRING 2013 ENDS COOLER AND WETTER THAN NORMAL
Meteorological Spring ends Friday (the months of March – April and May are the Spring months) and it was a wet one. With 14.05″ of rain since March 1, this spring ranks as the 22nd wettest on record.
Temperatures did recover after a very cold March. By March 31, 87 percent of the days were below normal, though, May has been warmer and offset the cold start to our Spring. Spring 2013 ends with 55 percent of the days below normal.
The start of meteorological Summer starts June 1 with an average high of 78° and warming to a normal high temperatures to 85°. June warming ranks 5th with the average high rising 7°. June rainfall averages 4.25″ (third wettest month on average). We gain 11 minutes of daylight peaking on June 21, the astronomical start of Summer – which comes at 1:04 a.m.