February 24 2007 chase

 

 

Targeted the northwestward nose of the moisture/instability axis east of the surface low in what was a fairly classic cold core scenario... though the highly occluded nature

of the system contributed to weak low-level shear.  Maintenance of low 50s dewpoints was forecast beneath very cold temps aloft, which would result in seasonably

impressive instability and decent 3km CAPE.  Unfortunately, much of this moisture mixed out rapidly from the southwest and low-level instability was quite limited. 

Thus storms had an extremely  narrow window of opportunity as they approached the retreating bank of stratus and backed surface flow ahead of the occluded front.  Had the

dewpoint axis wrapping into the system been anywhere near as broad/rich as was forecast by the RUC and NAM, I'd bet that some brief tornadoes would have occurred.

 

 

 

Images

 

1006am - agitated high-based cumulus, looking southwest from Newton KS.  The low-based tower in the far lower left portion of the image (kind of tough to make out) was rapidly developing into an incredibly beefy CB over eastern Harvey county, but I didn't take any more photos of it as I was already falling behind where I wanted to be.
1050am - got ahead of that CB... looking south from Peabody KS
1108am - shot of the dry slot
1119am - another storm northwest of the original one... looking west from near Marion Lake
1120am
1142am - did some waffling along Highway 56, but opted to let that storm go
1211pm - I believe this was the original CB from over eastern Harvey county, which was now crossing Marion Lake.  There was a tornado warning supposedly for a storm farther southeast, which I couldn't even see - or maybe I was just confused
1212pm - The patchy stratocu cleared and I noted explosive development of the CB while heading north to Lincolnville
1219pm - storm appeared to be quickly anviling out
1220pm - storm had a well-developed rain core and a very low base by this time.  Headed west of Lost Springs to stay close.
1228pm radar image; my storm earned tornado warning at this time
1230pm - nice structure and a distinct wall cloud south of Ramona
1253pm - storm became more disorganized and appeared multicellular northeast of Ramona
108pm - headed northwest for a stronger storm south of Abilene.  Structure on this one initially was quite nice (albeit high-based).
109pm
117pm - the storm looked more elongated as I reached it along Highway 15 (a characteristic not uncommon to mini-supercells in their early stages), and vertical growth had ceased.  It was likely entraining too much bone-dry air from the south.
156pm - waffled back and forth along I-70, then decided to stick with the original northwesternmost storm.... north of Solomon KS at this time.
200pm radar image; Solomon storm is over southeastern quadrant of Ottowa county
202pm - I was literally about to abandon it for a new cell south of Manhattan when the storm went bonkers on its hind flank.  Dynamic large scale rising motions occurred, including this nub funnel feature which was rotating decently.  View looking northeast.
A crop of the previous photo.  I was kind of surprised this didn't become a tornado.  Meanwhile, the explosive updraft was towering above me to the west of the highway.
206pm - I was in poor position and couldn't see the ground beneath the funnel, so I headed north and looked back south at the feature as it crossed the highway.  I kept heading north to stay ahead of it.  The lowering diminished, but strong stormscale motion continued for a while with inflow condensing and wrapping in from the north.

215pm - two distinct CBs, looking west down Highway 18 in eastern Ottwa county  I think the one that produced the strong cloud base motions was the one on the left (southern)

 
218pm
233pm - hind flank of weakening storm, looking back east
235pm - winds were out of the northeast here, with the bank of fog and stratus 5-10 miles to the north.  Headed home shortly after this.