U.S. Severe Weather Forecast (Конвекција-преглед)


acus01 kwns 241239 
Storm Prediction Center ac 241237 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0737 am CDT Sat Mar 24 2018 

Valid 241300z - 251200z 

..no severe thunderstorm areas forecast... 

thunderstorms are possible today from the lower Ohio Valley and mid 
south to the southeast Atlantic coast early Sunday. Isolated 
thunderstorms will also be possible along parts of the Pacific 
coast, and the Red River valley of Texas/Oklahoma. 

Clusters of elevated thunderstorms are ongoing over IL, in advance 
of a midlevel shortwave trough moving east-southeastward, in the 
zone of strongest low-level warm advection on the nose of a 40-50 kt 
southwesterly low-level jet. Though the midlevel trough will weaken 
slowly through the period, some form of this convection should 
persist through the day while spreading east-southeastward toward 
the southern Appalachians this evening and the southeast Atlantic 
coast early Sunday. Weak ascent along and just in advance of the 
trailing cold front could support isolated thunderstorm development 
this evening across the Tennessee Valley and mid south. 

There will be some low-end potential for elevated thunderstorm 
development near the end of the period in the strengthening warm 
advection regime to the north of front that will stall across north 
TX, and in advance of a low-amplitude speed Max ejecting 
northeastward from baja. A few thunderstorms will remain possible 
along the or and northern California coasts, as well as the Sacramento 
Valley, as a deep midlevel trough moves inland this afternoon. Very 
isolated lightning flashes may occur across western Montana in 
association with an ejecting/deamplifying trough today, and tonight 
with elevated convection across NE/South Dakota in a strengthening warm 
advection regime. In the latter two areas, however, the threat for 
lightning appears to be too marginal/sparse to warrant outlook 

.Thompson.. 03/24/2018 


Mesoscale Discussion

acus11 kwns 240103 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 240102 

Mesoscale discussion 0169 
National Weather Service Storm Prediction Center Norman OK 
0802 PM CDT Fri Mar 23 2018 

Areas affected...portions of eastern South Dakota...southwestern Minnesota...and 
northern Iowa 

Concerning...heavy snow 

Valid 240102z - 240700z 

Summary...a band of heavy snow will develop through the evening, 
with snowfall rates around 1 inch per hour likely. 

Discussion...a band of rain/thunderstorms across southeastern South Dakota 
into northwestern Iowa as of 01z is being supported by lift associated 
with a shortwave trough ejecting northeastward over the 
northern/Central Plains. A strengthening southeasterly low-level jet 
will increase in the thermal gradient around 850 mb. Although some 
sleet may occur initially, forecast soundings from the NAM/hrrr 
suggest mid-level cooling with the approach of the shortwave trough 
will encourage a fast transition from rain to snow across eastern South Dakota 
into southern Minnesota and northern Iowa as ongoing precipitation shifts 
into this area through 03-05z. 

A band of heavy snow will develop across this region later this 
evening into the early overnight hours, with strong low-level 
frontogenetic forcing and deep ascent occurring through the 
dendritic growth zone likely supporting snowfall rates around 1 inch 
per hour. Some localized higher rates to around 2 inches per hour 
may be possible within convective elements of the band, and an 
isolated lightning strike or two cannot be ruled out. Of note, there 
will likely be a sharp northern gradient to the heavy snow due to a 
residual dry low-level airmass being reinforced by strong 
east-northeasterly surface winds across parts of central/eastern Minnesota. 

.Gleason.. 03/24/2018 

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


Latitude...Lon 44179713 44569745 45219736 45639677 45579617 45379555 
45039488 44619427 44229364 43929318 43529272 43089247 
42759242 42569291 42969378 43329480 43449561 43709648