|Thursday, April 29, 2010 - 7:49AM CDT
4/29 forecast update IV
Posted 7:49AM CDT Thursday: The moisture situation has sealed the deal for today's Kansas/Nebraskan expedition being a no-go. Will post a forecast for the next 3 Midwestern expedition days later this afternoon after 12z model runs are out.
|2010 Storm Expeditions - Probabilities as of April 29|
|April 28-May 4||0%|
Posted 4:11AM CDT Thursday: Moisture return is not happening to the degree necessary for an appreciable tornado threat today in KS/NE. 60F dewpoints are still down along the Gulf coast - the low-level jet is cranking, but its influence drops off down where the deeper moisture is. It has only 15 hours until 'go time', therefore I'm very skeptical of the rapid accelleration of 60F dews northward into Kansas. Today is a no-go at this point for observing, unless something major happens with moisture return trends within the next 6 hours.
Posted 12:21AM CDT Thursday: Just a quick update on the situation per tonight's 00z model runs. For the Kansas target, initiation still looks like it will happen after sunset per the 4KM WRF and GFS, with the NAM deviating and firing storms along the KS/NE border before sunset. Flow aloft is great, but the low levels again are not quite up to par. Surface winds are shown due north, with 850mb winds veered. The dewpoint situation will have to be monitored closely, but it's a toss-up if better-than-forecast moisture will make it that far north. A supercell or two up in northern Kansas/southern Nebraska looks like a good bet for a few hours, but they may be high-based and quickly line out. At this stage, I'm still on the fence. If I wake up in the morning and see that the surface observations have defied the models, I'll still have more than enough time to make it to the target - the beauty of living closer to the Plains!
Friday and Saturday in the lower Midwest feature good winds aloft and better moisture, but are both a toss-up as far as low level wind configuration and storm mode. They are not setups I'd drive very far for, but since they both will be within my 'home' chase areas, I'll likely go out to simply see what happens. After this trough exits, the GFS and Euro keep indicating a significant quiet period for at least the next week - so I've lowered the expedition probabilities for that period once again.