Discussion

The week of our trip is now in range of the outer edge of the synoptic-scale model (NAM) and in the “believable” range of the medium range models, like the GFS.  The GFS and NAM both develop southwesterly flow at 500 mb by Friday 26 May, with surface moisture “return” from the Gulf of Mexico beginning in the south on Thursday 25 May, and then entering Oklahoma on the 26th.

The evolution of the pattern after that depends upon how the models handle the amplitude of the major trough in the West.   If the amplitude grows at the expense of progression, then southwesterly flow will linger over the area, with the NAM beginning to suggest that.

Both models leave a branch of the westerlies over Texas for the Sunday-Tuesday period.  Bulk shear in the 0-6 km layer of 35 knots phased with buoyancy shifts from Oklahoma on Saturday to central Texas on Sunday.  The GFS has a couple of short wave troughs embedded in the southern branch that probably will be players, if they verify.

Then, as the ridge in the middle and upper troposphere shifts eastward further north, two areas of favorable deep layer shear emerge, one in upslope in west Texas and New Mexico’s eastern Plains and another over north-central Oklahoma and Kansas with northwesterly flow aloft.

The net effect of all of this is that initially the pattern on Saturday focuses on central Oklahoma, with some impressive looking soundings and hodographs around Tulsa south to Ardmore.  Some of the hodographs have a midlevel weakness, though that kind of detail is not trustable this far out.

This is the forecast sounding and hodograph for somewhere along the I35 corridor south of Oklahoma City on Saturday afternoon 27 May.

And this is the forecast sounding and hodograph for someplace near Wichita KS on Wednesday evening 30 May.  What struck me about that pattern is how the wind profile evolves in the next hours, to one that looks extremely tornadic.  Of course, by this time surface temperatures will have cooled, but if a thunderstorm is existent and moves into that shear environment, there will be some interesting rotational developments near the surface, so to speak

.

So, we have changed our outbound reservations to arrival at Oklahoma City Friday evening around 10PM.