U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 300433 
Storm Prediction Center ac 300431 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
1131 PM CDT sun Mar 29 2015 

Valid 301200z - 311200z 

..there is a marginal risk of severe thunderstorms from southeast MS to southwest 
Georgia and the Florida Panhandle... 

Isolated thunderstorms are likely across the Gulf Coast states into 
the evening hours. A few storms could produce hail and gusty winds 
from southeast Mississippi to southwest Georgia and the Florida 
Panhandle. Additional thunderstorms are possible during the 
afternoon across southern Colorado...New Mexico and eastern Arizona. 
Overnight...isolated thunderstorms may also develop along the 
Washington and Oregon coasts as well as from southeast Oklahoma and 
northeast Texas into southern Arkansas. 


An upper trough over the eastern third of the U.S. Will shift east 
over the Atlantic today. Across the west...a ridge will exist from 
the northern rockies through the Great Basin. Low-level trajectories 
over the Gulf of Mexico will lead to modest moisture return across 
the Southern Plains...and to the south of a surface cold front from 
southern MS...Alabama and Georgia. 

..southeast MS...Southern Alabama...southwest Georgia and portions of the Florida 

Surface dewpoints will climb into the low 60s by afternoon as 
temperatures warm into the 70s to low 80s. This will aid in modest 
destabilization to the south of a weakening southeastward-advancing 
cold front. Convergence along the front will be weak...as will 
forcing for ascent. Deterministic and hi-res guidance suggest a few 
storms could develop near the cold front during the afternoon/early 
evening from southeast MS to SW Georgia and the Florida Panhandle in the vicinity of 
a weak surface trough...and on the fringes of stronger midlevel 
northwesterly upper-level flow. Given neutral height tendencies and 
weak forcing mechanisms...storm development will depend mainly on 
diurnal processes. However...steep midlevel lapse rates and 500 mb 
temperatures near -16 to -18 degrees c will pose a conditional hail 
threat. Gusty winds may accompany these storms as well. Given the 
conditional...and isolated...nature of the threat...a marginal area 
will be maintained from the previous day 2 outlook. 

.Leitman/Peters.. 03/30/2015 

Mesoscale Discussion

acus11 kwns 300358 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 300357 

Mesoscale discussion 0158 
National Weather Service Storm Prediction Center Norman OK 
1057 PM CDT sun Mar 29 2015 

Areas affected...southern Arkansas through northern MS and southwestern Tennessee 

Concerning...severe potential...watch unlikely 

Valid 300357z - 300600z 

Probability of watch issuance...5 percent 

Summary...storms will undergo an increase in coverage into the early 
morning from southern Arkansas through northern MS and southwestern Tennessee. A few storms might 
become capable of producing small to marginally severe hail and 
gusty winds. Threat appears marginal...and a ww is not anticipated. 

Discussion...late this evening thunderstorms have been on the 
increase from eastern Arkansas into northern MS and southwestern Tennessee along and just ahead of 
a cold front. The storms are developing within zone of modest 
moisture transport associated with a southwesterly low level jet and where deeper 
forcing accompanying a progressive shortwave trough has eroded the 
capping inversion. The storms are elevated and decoupled from 
boundary layer...but latest rap soundings indicate 500-1000 j/kg 
MUCAPE where steeper /7-7.5 c/km/ middle-level lapse rates overlap northestern 
extent of moist axis. The storms might become capable of producing 
small to marginally severe hail given cold temperatures aloft and 
steep lapse rates. Activity is also embedded in 45-55 knots flow 
through the convective layer so gusty surface winds cannot be ruled out. 
However...overall severe threat will remain limited by the 
stabilizing surface layer and marginal instability. 

.Dial/Edwards.. 03/30/2015 

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


Latitude...Lon 34579053 35158951 35418874 35278822 34558825 33748984 
33159242 33619297 34049169 34579053