U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 221941 
Storm Prediction Center ac 221940 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0240 PM CDT Wed Mar 22 2017 

Valid 222000z - 231200z 

..there is a marginal risk of severe thunderstorms ... 

thunderstorms capable of isolated damaging wind gusts and small to 
marginally severe hail remain possible over a portion of the Great 
Basin this afternoon and evening. 

..Great Basin area... 

No significant changes to current forecast, and will maintain a 
marginal risk for a few strong to severe storms this evening, but 
overall threat will remain limited by limited moisture and 

.Dial.. 03/22/2017 

Previous discussion... /issued 1042 am CDT Wed Mar 22 2017/ 

..Great Basin... 
Morning water vapor loop shows a well-defined shortwave trough over 
NV, with a mid/upper-level jet nosing into UT/AZ. Lift associated 
with this shortwave and jet structure will overspread northern Arizona 
and much of Utah this afternoon, providing the forcing mechanisms for 
scattered showers and thunderstorms. Low-level moisture is limited 
across this region (dewpoints only in the 30s), limiting the overall 
cape potential. However, breaks in the clouds and steep mid-level 
lapse rates will result in at least marginal instability throughout 
the area. Forecast soundings suggest the potential for small of 
possibly severe hail this afternoon and evening. Also, strong 
deep-layer southwesterly flow coupled with steep low-level lapse 
rates should promote gusty/damaging winds in the strongest cells. 


Mesoscale Discussion

acus11 kwns 222031 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 222030 

Mesoscale discussion 0308 
National Weather Service Storm Prediction Center Norman OK 
0330 PM CDT Wed Mar 22 2017 

Areas affected...northern Utah...northeast Nevada...southeast 
Idaho...southwest Wyoming 

Concerning...severe potential...watch unlikely 

Valid 222030z - 222230z 

Probability of watch issuance...5 percent 

Summary...an increase in thunderstorm coverage and intensity is 
expected through about 00z, with small to marginally severe hail 

Discussion...sporadic weak thunderstorm activity has been noted 
ahead of a cold front over central Nevada and within a surface trough 
from southern Nevada across Utah. Strong heating along with cooling 
temperatures aloft have resulted in a steep lapse rate environment, 
which is helping to create several hundred j/kg of MUCAPE despite 
dewpoints only in the 30s in most areas. Shear profiles are 
favorable for cellular activity, with increasing mid to high level 
flow elongating hodographs. This should help aid in hail production, 
mostly small. However, a cell or two could produce marginally severe 
hail and gusty winds over the next few hours as heating persists 
especially across northern Utah into southeast Idaho and southwest Wyoming. 

.Jewell/Hart.. 03/22/2017 

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


Latitude...Lon 41450875 40191207 39891371 40001477 40521580 40981554 
41241449 42091358 42831240 42811128 42600981 42230909