U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 210550 
Storm Prediction Center ac 210548 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
1248 am CDT Tuesday Oct 21 2014 

Valid 211200z - 221200z 

..no severe thunderstorm areas forecast... 

isolated thunderstorms are possible over parts of the interior 
west...western and southern Texas...southern portions of the Florida 
Peninsula...and parts of the northeast and middle-Atlantic region. 

An amplified flow field aloft is forecast to continue Tuesday...as a 
western U.S. Trough moves quickly east-northeastward across the intermountain region 
while a closed low evolves/shifts southeastward out of the lower Great Lakes 
toward the middle-Atlantic area. In between...a Sharp Ridge will 
prevail across central portions of the country. 

Aside from thunder potential across both southern Texas and southern Florida where a 
tropical airmass is prognosticated to linger through the period...deep 
convection this period is forecast to be associated with the two 
main/aforementioned upper troughs. In the west...showers and scattered 
storms are forecast to develop during the afternoon from the northern 
rockies southward to Arizona/nm/W Texas...gradually diminishing after sunset. In 
the east...showers and scattered thunderstorms are expected...from southern 
New England into the middle-Atlantic region. In all areas...severe 
weather is not expected. 

.Goss.. 10/21/2014 

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