TULSA, Oklahoma - The mid-level ridge will continue to slowly expand northwest out of the Mexican Plateau region and overspread at least part of the state through the next 5 days before slowly retrograding southwest and allowing a weak boundary to drop southward into part of northern Oklahoma early next week.  The only question will be the strength of the ridge and if decaying convection can survive into the northern third of the state from any upstream MCS activity.   The various model data offer different solutions regarding the northern extent of the strongest portion of the ridge and therefore different solutions.  The EURO and 12kNAM seems to be the most north and slightly stronger with the ridge while the GFS and to some extent the 3K continues to allow for some sneaky intrusion of leftovers into our part of the state.  There may also be some slight thermal differences in the data aloft.  Regardless... I see no reason to change from our current thinking and forecast which keeps these low-end rain chances for Thursday pre-dawn and possibly Friday early morning for the northern sections of the state.

Temps will slowly rise and then level off around 93 to 95 for the rest of the 7-day period for max highs with morning lows slowing expanding from the upper 60s into the lower 70s.  Dews in the GFS seem to be too high too quickly, while the EURO plots seem too low for too long.  The nice green vegetation across eastern Oklahoma will also pump moisture into the boundary layer through daily evapo-transpiration.  You’ll start to feel this process as the heat index continues to climb closer to the upper 90s today.  A blend model dews and some fuzzy math will be used to equate the temp heat index values which will bring us to near 99 through Thursday and then from 100 to 103 Friday into the weekend.  While these values will become quite noticeable, they’ll stay short of any official heat advisories from the NWS unless the GFS is correct.

Monday into Tuesday the H5 ridge slides southwest over New Mexico and allows a northern stream wave (well north) to shove a surface boundary southward.  This front clears northern Oklahoma in the EURO for Tuesday while hanging north in the GFS.  This is the time of year the fronts tend to stall, but it’s hard to bet against the EURO at this point.  We’ll plan on some north winds Tuesday afternoon into Wednesday with a few storms and a minor reduction in heat for a day or so next week.  

Thanks for reading the Wednesday morning weather discussion and blog.