U.S. Severe Weather Forecast (Convective Outlook)

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acus01 kwns 260539 
swody1 
Storm Prediction Center ac 260538 


Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
1238 am CDT Mon Jun 26 2017 


Valid 261200z - 271200z 


..there is a marginal risk of severe thunderstorms across parts of 
the southern and central rockies eastward into the southern and 
Central High plains... 


..there is a marginal risk of severe thunderstorms across parts of 
the Pacific northwest... 


... 
Thunderstorms with marginally severe hail and strong wind gusts are 
possible late this afternoon into early evening across parts of the 
Pacific northwest and from the southern and central rockies eastward 
into the High Plains. 


..southern and Central High plains/southern and central rockies... 
An upper-level ridge will be in place from The Four Corners region 
into the northern rockies with northwest mid-level flow over the 
High Plains. At the surface, southeasterly flow will help maintain a 
moist airmass across the southern and Central High plains. Models 
again forecast moderate instability to develop this afternoon from 
the foothills of the southern and central rockies eastward into the 
High Plains. As surface temperatures warm, isolated to scattered 
thunderstorms should initiate in the higher terrain of central and 
northern New Mexico and in the lower elevations of eastern New 
Mexico, southeastern Colorado and western Kansas. In addition to the 
instability, forecast soundings show substantial directional shear 
and steep lapse rates in the low to mid levels. This will likely be 
enough for a few marginally severe storms accompanied with hail and 
strong wind gusts. The threat should be concentrated in the late 
afternoon and early evening. 


..Pacific northwest... 
An upper-level trough will move to the West Coast today as a cold 
front advances eastward into the Pacific northwest. Ahead of the 
front, a narrow corridor of maximized low-level moisture is forecast 
to set up from southwestern Oregon northeastward into southeastern 
Washington and northern Idaho. As surface temperatures warm during 
the day, moderate instability is forecast to develop in this zone 
with isolated to scattered convection initiating in the late 
afternoon. In addition to low-level instability, mid-level lapse 
rates are forecast to be steep. This combined with substantial speed 
shear in the low to mid levels may be enough for a few marginally 
severe storms with hail and strong wind gusts. 


.Broyles/Mosier.. 06/26/2017 


$$ 

Mesoscale Discussion


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sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 260454 
txz000-nmz000-260530- 


Mesoscale discussion 1151 
National Weather Service Storm Prediction Center Norman OK 
1154 PM CDT sun Jun 25 2017 


Areas affected...the Texas South Plains into parts of the Permian 
Basin 


Concerning...severe potential...watch unlikely 


Valid 260454z - 260530z 


Probability of watch issuance...20 percent 


Summary...the corridor for 50-60 kt gusts will likely remain 
confined to areas northwest/west of Lubbock and North/East of 
Plainview during the next hour with a southward-migrating squall 
line. 


Discussion...radar mosaic shows a mature squall line from the Texas 
South Plains southwestward into southeastern nm. Measured severe 
gusts at multiple West Texas mesonet stations have observed gusts 
ranging from 50-71 kt during the past hour ---peak gust of 71-kt at 
Muleshoe. Despite nocturnal cooling of the boundary layer and a 
low-level stable inversion, a mesoscale convective vortex and associated rear-inflow jet 
will likely aid at least a risk for isolated severe gusts for the 
next hour and perhaps longer. Yet, the additional need for a severe 
watch due to a severe risk persisting for 3 or more hours south of 
the ongoing squall line/severe watch 370 is in doubt. 


.Smith/Hart.. 06/26/2017 


..please see www.Spc.NOAA.Gov for graphic product... 


Attention...WFO...lub...Ama...maf...abq... 


Latitude...Lon 32380408 34360252 34870099 34370089 33090171 32090317 
32060380 32380408