Weak cold front & upper trough passed last night, dumping anywhere from just 0.05″ to 4.20″ of rainfall in the area. About 75% of the viewing area picked up at least 1″ of rainfall. The remaining 25% (our southern areas) picked up much less with some places getting just 0.05″. The delination between the heavy rainfall & very little was sharp.
Where the heavier rain occurred, significant chunk was taken out of the rainfall deficit for 2012.
Who needs Isaac when we get this kind of rain over a good chunk of the area with just a weak cold front & upper trough? What’s behind this kind of rainfall? Well, it wasn’t incredibly unstable, there was not impressive dynamic support. There was instability for some thunder & lightning, but little else. The rainfall was intense, though, where it set up with a large area of ascent or lift, producing a large area of rainfall.
Origins of this moisture was in the subtropical/tropical Pacific with its first end roads in the Desert Southwest with widespread flooding. This moisture plume brought up to 2″ of rainfall to drought-plagued Kansas. Our dew points reached low to mid 70s last night, something rare for this summer. The atmosphere was loaded with water like a soaked sponge, resulting in high precipitable water values. Also, the rainfall was slow-moving resulting in impressive accumulations over a chunk of the area.
The heaviest band ran from Benton & northern Warren to northwestern & northern Tippecanoe counties where totals were 3-4.20″. At WLFI, the 2.98″ was the heaviest rainfall total in a day since June 2011 when 2.93″ fell.
Across Lafayette/West Lafayette Metro, the south half of this area received 1.25-2″ of rainfall, but the north & west half received up to 4″! In fact if you drive from near the Purdue Airport to the northeast side near I-65 & 25, your total will go from 2.49″ to 3.41″. Drive from there to WLFI & it goes from 3.41″ to 2.98″ & from there, drive to around the Agronomy Farm & then Montmorenci & it will go from 2.98″ to 3.60″ to 3.93″. Drive from Montmorenci to Route 26 southwest of Klondyke to Pine Village & the totals from from 3.93″ to 4.13″ to 4.20″. Take a drive to Crawfordsville & the rainfall drops to 0.27″!
At Indianapolis, Indy Executive Airport received just 0.07″ (eastern Boone County near Route 32), but Indianapolis International picked up 1.42″.
1.8 Miles Northwest of Pine Village (CoCoRHas observer) 4.20″
Halfway Between West Lafayette & Otterbein – Station at Route 26 & Indian Creek 4.13″
Pine Village 4.03″
Lafayette Far Northeast Side at Route 25 & & Near E 300 N 3.41″
Purdue Airport 2.49″
Indianapolis International Airport 1.42″
Lafayette Southeast Side 1.37″
Grissom Air Reserve Base 0.97″
Indianapolis Executive Airport 0.07″