Verification

Verification by Blake Cotcamp (bcotcamp@purdue.edu)

The forecast for Northern Indiana on Thursday called for clear skies during the day with high temperatures in the range of 25-30 degrees and the potential for some light snow late at night. Observed highs ended up being slightly warmer than forecast, as KLAF reported a high temperature of 34 degrees, while generally clear skies were indeed seen. The forecasted snow for the late night hours did not materialize, and although the radar during those hours did show a band of precipitation moving through Northern Indiana, it only resulted in lightmist/fog at the surface.

Friday's forecast for Northern Indiana called for a chance of a dusting of snow in the morning hours, with a chance for more light snow in the later afternoon hours. It turns out that this forecast severely underestimated the amount of precipitation that occurred/is ongoing, as heavy snow bands entered the region around 11 am resulting in at least 2 inches of accumulation. This forecast error was due to an unforeseen zone of frontogenesis setting up over Central Illinois and Indiana which resulted in large amounts of lift over the area. It should be noted, however, that the GFS on Thursday actually picked up on this frontogenesis occurring on Friday, but at the time was seen as an outlier.

Radar image at 1912z on Thursday showing the precipitation that was supposedly occurring over Northern IN.

Radar image at 1745z on Friday showing the heavy band of snow that developed over North-Central Illinois and Indiana,

Current Indiana:

The lower 2/3 of the state are seeing light to heavy snow. Lafayette saw a heavy band of precipitation that wasn't forecasted by models. Indianapolis and further south are seeing heavy snow with low visibilities as were expected. Lafayette has seen approximately 0.5” of new snow which the potential for more on the way as radar shows a short break before another moderate band looks to move through in the next few hours. Additional accumulations look be possibly half an inch with locally slightly higher totals. Indianapolis and south looks to be on par with seeing 2-4” as heavier snow moves through this area. Most of the precipitation looks to move out of Indiana by midnight.

Temperatures are holding in the mid teens in Lafayette and warming into the 20s and low 30s from north to south. They will remain relatively constant through the rest of the day before a cold blast enters on Saturday. Winds are currently variable and light, but will shift to northwesterly tomorrow accompanying the colder air.

Current around the country:

The noreaster is moving out of the New England area, but some snow is still falling in Maine and scattered throughout the east coast. The west coast continues to be bombarded by rain from disturbances coming out of the Pacific. Flooding is definitely a concern for those in Oregon and Northern California.