THUNDERSTORM THREAT TODAY, WEDNESDAY AND THURSDAY!

Chances for some severe thunderstorms next few days.  Below I have posted the latest Day1, Day2 and Day3 severe weather risk maps from the Storms Prediction Center in Norman, Oklahoma.  Here's the link to the Storms Prediction Center.

Day1, that's today, has a broad area of slight risk over central and southern OK and northern TX. Weak surface boundary stalled over southern and southeastern OK this afternoon with decent flow aloft but not any where close to a classic set up.  However, instability is high and most short term forecast computer models initiate scattered thunderstorms in the slight risk area with the main threat large hail, damaging winds, lightning and locally heavy rainfall.  Thunderstorm intensity and coverage should decrease with loss of daytime heating.

Day2 has a large slight risk area mainly to the north of Oklahoma!  The upper level westerly flow gets stronger and better organized and more focused over the central plains.  This causes a lee side surface trough to develop east of the rockies which in turn increases southerly surface flow bringing warm and moist air north into the plains.  A cold front will move slowly southeast into the central plains and with the strong jet stream aloft and increasing warm moist inflow ahead of front I expect strong to severe thunderstorms to develop in the central plains southward through Kansas by late afternoon / evening.  Main threat appears to be large hail and damaging winds, lightning and heavy rainfall but I can't totally rule out tornadoes.

By very late on Day2 Wednesday a dry line will mix out east across the TX and OK Panhandles into far western OK.  Look for isolated to scattered thunderstorms to form near the dry line moving into western OK Wednesday evening with the main threat large hail and damaging winds.  These t'storms will weaken after sunset but as low level jet increases overnight Wednesday night it's not out of the question that thunderstorms could persist into central OK during the wee hours on Day3 or Thursday morning.

Day3 shows a slight risk for severe thunderstorms jumping over into eastern and southeastern Oklahoma and points east from there on Thursday.  The strongest jet stream winds, in other words the core of the upper level wind flow, is shifting south into the southern plains but at the same time the surface boundaries are being shoved east as well.  There is some uncertainty regarding the exact position of the surface cold front / trough / dry line in Oklahoma on Thursday.  How far east will boundaries end up?  This will determine exactly where thunderstorms form. Most computer guidance indicates these boundaries as far east as eastern Oklahoma by Thursday afternoon so that's where we have the slight risk right now.  However, again there is some uncertainty as to where these surface features set up this far out in time.  Depending on how the upper level jet set up these surface boundaries could be more west into central Oklahoma or continue the trend east into eastern Oklahoma.  I don't know yet!  At any rate, strong to severe thunderstorms could develop along and ahead of these boundaries Thursday and Thursday night with the main threat large hail, damaging winds, lighting and heavy rainfall.  I can't rule out tornadoes in this situation but too far out in forecast time for details.  The further out in time we go the less accurate the details will be so obviously a Day3 forecast is just to highlight an area of possible concern.  Later data will shed more light on exactly how this sets up and where exactly these surface boundaries will be by Thursday evening.  At this point the best forecast is where you see the slight risk area. Stay tuned on this one.