Extended forecast from Greg/Fox Weather

** More Record warmth at OKC **
** Severe Weather Possible Across far NW OK Wednesday Evening **
** Widespread Significant Severe Weather Possible Thursday Evening **
** Isolated Severe Weather Possible Friday **

A record warm morning low was experienced in OKC this morning. This morning we saw 78 degrees. The old record of 75 was set in 1913. The record high for this date is 95 set in 1911. This record may be in jeopardy too.

0Z GFS, 0Z and 12Z NAM were used for this update. A severe storm or two producing very large hail and high winds looks possible across far northwest OK, probably near Buffalo again, after 6 pm. The storms will likely track east-northeast into Kansas before reaching Medford. A triple point low-dryline-warm front intersection should be around that area around 6 p.m., hence the reasoning behind the outlook. NAM suggests CAPE of around 3,000 j/kg across that area.

A low level jet stream sets up tonight, out of the south instead of the southwest. The upper wind fields remain quite strong through Thursday, and I am somewhat concerned about storms being sheered so highly they lean over and fall down. NAM suggests 600 m/s2 helicity across far western Oklahoma tomorrow evening. Given strong upper level support and some negative tilt to the approaching shortwave, this might not be such a big problem.

Storms are expected to initiate sometime after 4 p.m. along a dryline/weak cold front near a line from Alva to Altus. SPC Day 2 already has a moderate risk out for areas north of I-40. CAPE looks to be around 2,500 j/kg with perhaps 3,000 j/kg across southwestern Oklahoma. NAM suggests cap strength may be slightly weaker across southwest OK earlier in the event so I suspect initiation might occur in this area first but it is difficult to know for sure. 700 mb winds are unusually strong and I would suspect faster-than usual storm motion for June. Storms that become rooted in the boundary layer of course may slow down and turn right. I am guessing storms would move northeast at 35-40 mph, given QPF spread and vertical wind profiles.

Model QPF from the past several runs indicates these storms may eventually form a squall line. Historically speaking, events of this nature this time of year should start out supercellular, especially given strong sheer. QPF suggests the line staying west of OKC through 1 am but this timing might be a little generous. Needless to say, an overnight tornadic event is possible across central and eastern Oklahoma.

On Friday, once the main upper level system passes, models suggest another area of high cape in the neighborhood of 2500 j/kg could form along the dying boundary, which according to both the GFS and NAM runs, never makes it through OKC. At this time, it appears the boundary may line up from around Frederick to Ponca City, putting areas south and east of that in another risk for severe weather during the late afternoon and evening. Upper level winds appear to be considerably weaker and not as favorable for tornadic weather, however large hail looks to be a good bet.

I just looked at SPC day 2 for Thursday after reading this and noticed north-central and central OK are in the moderate risk. However, I think this may have been done to take into account the widespread nature of severe weather expected after dark when there's a better chance of more linear activity. It appears SPC is in good agreement with my thoughts. I think they need to expand Day 3 back into much of central Oklahoma though.

Beyond this, the winds stay howling out of the south the next many days. Low pressure continues to redevelop over and over from Denver cyclones developing off the junction of the Palmer Divide and the Rocky Mountains. The Denver cyclones then generally move east to east-northeast back into western Colorado with drooping fronts and attendant risks of severe weather, mainly in Kansas. Over the next week, it appears widespread almost monsoonal typical south Texas heavy rain events will set up with Oklahoma high and dry in the middle. We'll probably see some cloudiness from this going on as we get into early next week. The next front of any significance, if it actually materializes, may actually be on day 12. Daily highs will be a function of wind direction (southwest or not) and morning lows will be a function of cloud cover and wind speeds, combined with dew points. Models indicate the upper level ridge will generally stay parked over the southeast US until about mid-week next week when it may start to heat up again. However, 850/700 mb temps do not support going above the low 90s at this time. Record morning lows are all 75 degrees or above the next 12 days. Some of these may be in jeopardy but it is difficult to tell.

The dry line will generally remain in the Texas panhandle through next week, and if this pans out, may allow enough humidity back into western Oklahoma to reduce the fire danger some, despite the high winds continuing. Mesonet data indicates very dry soils across southwest Oklahoma despite reports of green vegetation. Areas that do not see significant training of storms on Thursday will likely have high fire danger soon, especially the western counties bordering Texas.

OKC 95 74/94 70/88 70/990 71/92 73/91 72/90 72/91 73/91 74/93 75/93 68/88
pops..60% thursday night, 40% friday. 20% a week from Sunday (day 12)
Windy to breezy practically every day. Windiest today and Thursday.
Lightest on Friday.

State forecast graphics and more at www.okcfox.com

Greg