U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 220602 
Storm Prediction Center ac 220600 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0100 am CDT Wednesday Oct 22 2014 

Valid 221200z - 231200z 

..no severe thunderstorm areas forecast... 

isolated thunderstorms are expected today particularly across parts 
of the upper Midwest and the central and Southern Plains. Other 
thunderstorms are possible across the coastal northeast...Pacific 
northwest...and South Florida. 

A progressive belt of westerlies will exist over much of the Continental U.S. 
To the west of a closed cyclone centered near the 
mid-Atlantic/northeast Seaboard. The main corridor of thunderstorm 
potential across the plains/upper Midwest will be influenced by an 
eastward-moving shortwave trough over the northern plains/central 
Canadian provinces and an associated cold front. Isolated 
thunderstorms will also be possible in areas including South 
Florida...the coastal Pacific northwest...and the coastal northeast 
states where a modestly unstable warm sector will graze coastal New 

..central/Southern Plains to upper Midwest... 
DPVA/warm advection preceding the aforementioned shortwave trough 
will contribute to thunderstorm potential as far northeast as the 
upper Midwest today. A few strong storms may be possible across 
parts of Central Plains this afternoon/evening in association with a 
modestly buoyant warm sector adjacent to the advancing front...or 
possibly across eastern Colorado in association with weak low-level 
upslope. However...relatively weak vertical shear/limited middle-level 
lapse rates suggest that severe probabilities are not currently 

.Guyer/corfidi.. 10/22/2014 

Mesoscale Discussion

acus11 kwns 151721 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 151720 

Mesoscale discussion 1899 
National Weather Service Storm Prediction Center Norman OK 
1220 PM CDT Wednesday Oct 15 2014 

Areas affected...central Maryland into southeastern PA 

Concerning...severe potential...watch unlikely 

Valid 151720z - 151945z 

Probability of watch issuance...20 percent 

Summary...an isolated strong wind gust or brief/weak tornado cannot 
be ruled out with storms as they develop northward from Maryland into southeastern PA. 

Discussion...an isolated strong cell with substantial vertical 
development continues to propagate northward along a north-S oriented boundary 
which extends into PA and links with an existing front across eastern PA 
which currently separates the more moist/unstable air to the southeast. 

This particular storm has had a persistent and broad circulation 
with it...but nothing particularly strong or tight probably due to 
weak low-level buoyancy/acceleration. While deep-layer flow is 
strong above the ground...most of the shear is relegated to the 
near-surface layer and other cells away from the outflow boundary 
have shown little if any shear. Therefore...any wind/tornados threat is 
expected to be brief...short-lived and isolated...and a watch is not 

.Jewell/corfidi.. 10/15/2014 

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


Latitude...Lon 39157664 39007677 38987688 39067699 39267696 39617690 
40007679 40347640 40457615 40407593 40137594 39617620