Monday, July 15, 2013

Retrograding Low

A bizarre meteorological event took place over the weekend in that an area of low pressure to develop over the upper Ohio valley would make a unusual journey from east to west. Showers and storms forming on the western side of this system and propagating to the WNW as the parent circulation traveled across Southern Illinois was advertised on the 4KM WRF for Saturday. Though convection would end up not being as robust as the particular model suggested, I still headed down to the I-70 corridor. Anything to potentially fire would not only be moving opposite of the normal flow but also front lit from the waning daylight.

The low center showed up nicely on satellite.

c/o COD Meteorology

Convection was of the pulse variety in that cells would not sustain for long however, a distant one over Olney took off surprisingly well at peak heating. Using the 300mm so to not miss the wall cloud before it dissipated, a look at velocity confirmed that there was some rotation with this storm. Despite trying to get much closer, the complex would lose its vigor soon after.

c/o RadarScope





Separate cluster to the south.


Note the purplish front lit arcus cloud associated with outflow ejecting towards the west vs. east.


The now dissipating initial cell cluster with 'downstream' anvil.






Heading home, I stopped just north of Effingham along I-57 to try for lightning on a new cell to the NE near Casey. Despite seeing a few flashes while approaching, I would be too late and only observe the dissipating downstream remnant rain core. Melinda Swinford was shooting directly opposite and captured the best side of this storm at its peak. Her image SEEN HERE is nothing short of a career shot due to the rare movement interacting with available sun as well as moon light!

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