FINAL UPDATE: Thu 27 May 2010 / 3:20p.m.
Very little has changed; slightly drier air on an east to northeast wind flow will make for pleasant conditions during the evening and morning hours. An upper ridge should provide stable skies through Sunday afternoon.
It will be quite hot each day with highs in the 90-94 degree range. A chance of thunderstorms shows up by Sunday night as a trough pushes a front our way. (see new map just below).
Upper trough (dashed black line) and a deeper low to north (blue "L" along Canadian border) may push a front near us by Sunday night.
UPDATE: Wed 26 May / 10pm
The forecast remains the same: hot and humid with no rain expected Fri-Sat, and still a question for Sun-Mon as a front heads our way.
UPDATE: Tue 25 May 2010 / 3:35p.m.
A weakness developed in the mid-level flow since Monday's blog. This will contribute to a chance of rain. A weak front moving in Thursday will continue a rain prospect in the 20% range. I have nice weather for Friday and Saturday under the ridge shown on the map below.
The models weaken the ridge by Sunday so the threat of rain may slowly increase for the second half of he Holiday weekend.
UPDATE: Mon 24 May 2010 / 3:35p.m.
Little change to my blog from last Thursday; a weak front should stall to our west mid-week, which keeps the rain chances over western OK/TX. A second one Friday has a chance to reach Texoma. However, an upper ridge aloft (map) suggests the frontal lifting will fight against the sinking under the ridge, so I'm only putting a 20% chance for showers Friday.
Disclaimer: Tn unforeseen weakness in the ridge would allow for isolated showers this week. Since the odds of any one point getting rain are extremely low, I have not put it in the forecast.