U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 170041 
Storm Prediction Center ac 170039 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0639 PM CST Sat Nov 16 2019 

Valid 170100z - 171200z 

..no severe thunderstorm areas forecast... 

the risk for severe thunderstorms appears negligible across the U.S. 

..01z outlook update... 
A cluster of thunderstorms approaching North Carolina coastal areas 
appears supported by an area of upper forcing for ascent, which has 
been spreading northeastward, east of coastal areas, to the north of 
the center of the mid-level cyclone. It appears that this activity 
could spread into the North Carolina outer and inner banks vicinity, 
where the surface frontal zone remains closest to coastal areas. 
Elevated instability to the immediate cool/northwest side of the 
frontal zone is generally weak due to poor mid-level lapse rates, 
and it is not clear that thermodynamic profiles evident in the 
17/00z raob from Morehead City NC will support lightning. It 
appears that the risk for lightning becomes increasingly negligible 
with inland extent from immediate coastal areas. 

.Kerr.. 11/17/2019 


Mesoscale Discussion

acus11 kwns 151935 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 151934 

Mesoscale discussion 2149 
National Weather Service Storm Prediction Center Norman OK 
0134 PM CST Fri Nov 15 2019 

Areas affected...northern and western ME to the Champlain Valley 

Concerning...heavy snow 

Valid 151934z - 152300z 

Summary...snow squalls should push east-southeast from the Saint 
Lawrence valley, most likely across portions of northern and western 
ME between 4 to 7 PM EST. A brief period of heavy snow with 0.5-1.0" 
in 30 min is likely. 

Discussion...19z surface analysis placed a cold front across the 
Saint Lawrence valley. Canadian radars in Montreal and Quebec city 
have sampled a snow squall along the front. Somewhat enhanced 
reflectivity was noted along the eastern portion of the squall near 
Quebec city, which is consistent with a recent increase of 
low-topped convective development/colder cloud tops in visible and 
infrared satellite imagery. Recent amdar data near Montreal sampled 
inversion heights to 750 mb and near Quebec city to 700 mb. Latest 
rap/NAM guidance both are consistent with inversion heights further 
deepening as the shortwave trough and attendant cooling aloft 
approaches from southwest Quebec. Lack of stronger convergence along 
the front, in addition to a modest surface rise/fall couplet 
behind/ahead of the front, does suggest that squalls which progress 
across the international border will probably subside within a 
couple hours after sunset. 

.Grams.. 11/15/2019 

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


Latitude...Lon 45347358 45757143 47606922 47386776 47036763 45686894 
44617101 44057257 43947341 44197411 44847428 45347358