U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 250049 
Storm Prediction Center ac 250048 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0748 PM CDT Thursday Apr 24 2014 

Valid 250100z - 251200z 

..there is a slight risk of severe thunderstorms across portions of the lower 
Mississippi and Tennessee valleys... 

Scattered strong to severe thunderstorms are expected across the 
lower Mississippi Valley this evening...with the activity spreading 
east into parts of the lower Ohio and lower Tennessee valleys 
through early Friday morning. Damaging winds and isolated large 
hail will be the primary threats. 

The slight risk area has been trimmed on the western and northern 
edges based on latest position of surface cold front and the 
juxtaposition of better low level moisture/lapse rates and effective 
shear over the lower MS valley. A cluster of storms currently moving 
into southeast Arkansas as well as another cluster further east 
moving into northern and central Mississippi will pose the greatest 
threat for strong winds...isolated large hail and possibly a tornado 
in the short term. As these storm clusters track eastward 
overnight...a threat for locally damaging winds and hail will 
continue into the Tennessee Valley. 

.Leitman/Hart.. 04/25/2014 

Mesoscale Discussion

acus11 kwns 250144 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 250144 

Mesoscale discussion 0400 
National Weather Service Storm Prediction Center Norman OK 
0844 PM CDT Thursday Apr 24 2014 

Areas affected...southeastern Arkansas...north central-northestern la...and northern/central 

Concerning...Severe Thunderstorm Watch 90... 

Valid 250144z - 250245z 

The severe weather threat for Severe Thunderstorm Watch 90 

Summary...additional MS counties have been included in ww 90 as two 
strong-severe storms move eastward across central MS. Trends will be 
monitored eastward into Alabama for a new ww. 

Meanwhile...a threat for damaging winds and some hail persists with 
a line of storms moving into southeastern Arkansas toward west central MS. 

Discussion...at 0130z...mosaic radar imagery showed two 
strong-severe storms in central MS /one an hp supercell in eastern 
Holmes and Attala counties/. These storms appear to be located 
along the southern extent of a convective outflow boundary which was 
attendant to the leading edge of a band of convection moving eastward 
through western Tennessee into northestern to west central MS. The southern extent of the 
outflow boundary was interacting with a corridor of moderate 
instability extending from la into southern/central MS per objective 
analyses. This combined with height falls and stronger forcing for 
ascent attendant to the compact shortwave trough tracking east 
toward the lower Tennessee Valley should sustain the ongoing storms and 
support new development as activity spreads eastward. A strengthening 
south-southwesterly low level jet at 35-40 knots per WSR-88D vads at Jan and lix extending into 
central MS has resulted in an increase of low level hodograph 
curvature such that storms across central MS could pose a tornado 

The severe weather threat should persist eastward across central 
MS...with the recent hrrr runs suggesting these storms could remain 
strong-severe as they move into western Alabama. While a few rows of Alabama 
counties would be affected...potential also exists for the overall 
severe weather threat to diminish with eastward extent into central Alabama as 
the aforementioned outflow boundary and leading edge of convection 
outruns the greater instability in the lower MS valley. 
Meanwhile...the storms moving into southeastern Arkansas may weaken once they 
reach west central MS where the air mass has been convectively 
overturned from storms currently in that area. 

.Peters.. 04/25/2014 

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


Latitude...Lon 33729274 34109144 34229047 34559000 34998969 34908933 
33998978 33878941 33878875 33828846 34248810 34118722 
33658723 32848755 32548807 32558969 32529077 32189198 
32129244 32199337 33729274