There’s not a lot of change from the briefing yesterday. The main change is in the 15% probability area being split north and south, leaving a 5% risk area in most of western Kansas.
NWS Dodge City Discussion:
Short range models continue to show an upper level shortwave trough lifting northeast across the Central Rockies today resulting in an increasingly difluent southwest flow aloft across the Western High Plains. Meanwhile, a prevailing southerly flow will continue to draw moisture up into central and much of western Kansas ahead of an approaching dryline pushing surface dewpoints well up into the 50s(F). Increased instability with SBCAPE values upward of 1500 to 2000 J/kg and a modest +60kt upper level jet will set the stage for possible thunderstorms ahead of the dryline late this afternoon into early evening as H5 vort maxima eject out of the Southern Rockies into the Western High Plains. Although capping could be a hindering factor to storm development initially, steepening low/mid level lapse rates, sufficient instability, and moderately favorable shear may be enough to support strong to marginally severe thunderstorms in an axis of increased convergence associated with the dryline.
NWS Goodland Discussion:
Today the dry line will advance east as south-southwest winds bring in lower dew points. The dry line will stall between Highway 27 and Highway 25 by noon. Meanwhile an upper level short wave trough will deepen over the dry line. During the latter half of the afternoon CINH will weaken and allow isolated to scattered storms to develop near the dry line. During the late afternoon the CINH will be at its lowest and lift will be strongest, so am expecting the storm coverage to be highest. Mixed layer CAPE will be 1500-2000j/kg during the afternoon. Effective shear will be 40-50 kts, 0-1km shear increases to 20 kts by early evening, and helicity also increases as the low level jet strengthens late this afternoon.
With this in mind, severe thunderstorm development is favored, especially east of Highway 83 where the nose of the low level jet will add to the lift. The window for severe thunderstorms may last an hour or two into the evening before the environment becomes too stable and before the storms move east of Norton/Graham counties. The severe thunderstorms will be capable of producing hail up to hen egg size, 60-70 MPH wind gusts, and a tornado.
The risk for a tornado will be from 6-8 PM CT east of Highway 83. Looking at the tornado parameter from SPC, the data is suggesting EF1 tornado intensity should one form. Confidence for tornadic development and damaging winds is moderate while confidence for large hail is high.