U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 250506 
Storm Prediction Center ac 250504 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
1104 PM CST Tuesday Nov 24 2015 

Valid 251200z - 261200z 

..no severe thunderstorm areas forecast... 

severe storms are not expected through early Thursday. 

A shortwave impulse will dampen as it slowly tracks east across the 
northern Great Basin. This feature will remain embedded within a broad 
positive-tilt trough from S-central Canada to the California coast. Persistent 
southerly low-level flow over the southern Great Plains will yield gradual 
poleward moisture advection through the period. In conjunction with 
moistening on 700-mb swlys from northwest Mexico into the High 
Plains...meager elevated buoyancy should develop tonight into early 
Thursday. This may support sporadic thunderstorms late in the period within 
isolated to scattered showers...as more prominent thunderstorm potential 
awaits d2. 

.Grams.. 11/25/2015 


Mesoscale Discussion

acus11 kwns 211627 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 211626 

Mesoscale discussion 1992 
National Weather Service Storm Prediction Center Norman OK 
1026 am CST Sat Nov 21 2015 

Areas affected...portions of central Indiana 

Concerning...heavy snow 

Valid 211626z - 211830z 

Summary...observational trends suggest that the southern extent of a 
heavy snow band becoming established from northern Illinois to Southern Lower 
Michigan...is also extending into parts of central Indiana. Snowfall rates 
around 1 inch per hour will be possible with this activity into the 
afternoon hours. 

Discussion...the risk for heavy snow addressed in recently issued 
mesoscale discussion 1991 is extending southward into parts of central 
Indiana. Wet-bulb cooling within the boundary layer is encouraging 
the recent phase-change to...and maintenance of...snow. This is in 
association with a shield of precipitation advancing east-northeastward across 
the lower Great Lakes region. Surface observations at the 
Lafayette/purdue University ASOS indicate heavy snow...with a recent 
amdar sounding near Indianapolis suggesting deep near-/sub-freezing 
temperatures favoring efficient snow aggregation. These factors 
suggest that the heavy snow risk...with rates of 1 inch per 
hour...is extending southward into central Indiana. Present indications are 
that heavy snow will last into the afternoon hours....enhanced by 
ample 700-mb frontogenesis...and eventually maintained by 
deformation-zone related ascent. 

.Cohen.. 11/21/2015 

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


Latitude...Lon 40738724 41038614 41168508 41028478 40698507 40258604 
39728670 39638729 39928749 40338749 40738724