U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 161924 
Storm Prediction Center ac 161922 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0122 PM CST Tue Jan 16 2018 

Valid 162000z - 171200z 

..no thunderstorm areas forecast... 

thunderstorms are not forecast over the contiguous U.S. Today or 

No change is needed to the previous forecast. 

.Smith.. 01/16/2018 

Previous discussion... /issued 0940 am CST Tue Jan 16 2018/ 

A stable pattern will persist across most of the Continental U.S. With an 
amplified upper trough over the east and a large area of high 
pressure centered over the plains. This will result in increasing 
offshore flow across the Gulf Coast and southeast. 

To the west, a progressive shortwave trough will continue to move 
northeast across WA, with a large surface low well to the northwest. 
The cool temperatures aloft associated with this feature combined 
with low-level warm advection is currently resulting in a few 
showers with sporadic lightning across coastal Washington. However, this 
wave will rapidly leave the region, with no further thunderstorms 


Mesoscale Discussion

acus11 kwns 161309 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 161309 

Mesoscale discussion 0028 
National Weather Service Storm Prediction Center Norman OK 
0709 am CST Tue Jan 16 2018 

Areas affected...south central into a portion of southeast Texas 

Concerning...freezing rain 

Valid 161309z - 161615z 

Summary...light freezing rain with rates up to .02 inches per hour 
mixed with some sleet at times will likely persist next few hours 
from south central into a portion of southeast Texas. The corridor 
of freezing rain should slowly shift southeast with time. 

Discussion...early this morning an Arctic front has pushed into deep 
south Texas with temperatures falling into the upper 20s f farther 
north across south-central Texas. RUC sounding and vwp data indicate 
this front is less than 1 km deep with a pronounced warm nose around 
850 mb. A shallow convective layer is also evident between 850 and 
700 mb. Frontogenetic forcing in the 900-700 mb layer with weak 
isentropic ascent will continue to promote the development of patchy 
showers this morning with freezing rain being the primary concern. 
Some of the freezing rain may mix with sleet and change to snow 
before ending from the west as the deeper cold air spreads southward 
with time. 

.Dial.. 01/16/2018 

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


Latitude...Lon 30079786 30039684 30189552 29689506 28899667 28649875 
29120047 30119995 30079786