U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 301300 
Storm Prediction Center ac 301259 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0759 am CDT Wednesday Jul 30 2014 

Valid 301300z - 311200z 

..no severe thunderstorm areas forecast... 

isolated severe storms are possible across portions of Oklahoma and 
North Texas this afternoon into evening. 

..srn plains this afternoon and evening... 
Guidance continues to suggest a convectively-enhanced midlevel 
shortwave trough...currently moving east-southeastward through southwestern Kansas...will 
track into central OK by this afternoon and reach the OK-Arkansas border 
by 31/12z. Early morning surface/streamline analyses showed an area 
of low pressure in far southwestern Kansas with a wind shift extending southeastward 
through northern to east-central OK. A second boundary extended 
generally west-east across North Texas to southeastern nm. Meanwhile...a cold front 
trailing southwestward from the Kansas low will advance across the Texas Panhandle 
with thunderstorm development possible in vicinity of this boundary across the eastern Texas 
Panhandle and adjacent parts of western-southwestern OK and western North Texas during 
the middle to late afternoon. 

Trends in radar imagery showed a large area of rain/embedded 
convection extending from southwestern Kansas through the eastern OK/Texas panhandles 
through much of OK to far North Texas. The greatest concentration of 
thunderstorms was located over the eastern Texas Panhandle into western OK...closer to 
the midlevel impulse. Given the track of the shortwave trough and 
the southerly low level jet shifting eastward to North Texas and OK...DPVA with the trough 
and low-level warm air advection suggest the large area of convective rain showers 
and embedded thunderstorms will continue to spread eastward. Differential 
heating along the southwestern-southern periphery of this large convective system 
should become the primary effective surface boundary...with the southwestern 
Kansas surface low tracking along this feature into the southeastern Texas 
Panhandle by 31/00z and then into north central Texas by 31/12z. 

A moist environment is present this morning across the Southern Plains 
with precipitable water values ranging from 1.4-1.9 inches per 12z soundings. 
Visible satellite imagery indicated breaks in the cloudiness across 
the western Texas Panhandle. As the Southern Plains convective system shifts 
eastward...additional breaks in the clouds/surface heating should develop 
ahead of the cold front. However...relatively weak midlevel lapse 
rates per 12z soundings within the monsoonal moisture plume remain a 
limiting factor for stronger destabilization today and higher severe 
probabilities. MLCAPE should approach 1000 j/kg. This combined with 
effective bulk shear of 35-45 knots and DPVA attendant to the trough 
will support some organized storms from later this afternoon into 
the early evening. Locations with stronger mixing/steeper low-level 
lapse rates could enhance a threat for stronger wind gust. 
Vertically-veering winds...especially in vicinity of the differential heating 
boundary...could prove more favorable for a brief tornado threat. 
Meanwhile...the weak midlevel lapse rates may tend to limit the size 
of any hail production. 

If later data suggests the development of stronger instability than 
that currently forecast...an upgrade to a categorical slight risk 
may become necessary in subsequent outlooks. 

.Peters/Bothwell.. 07/30/2014 

Mesoscale Discussion

acus11 kwns 292036 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 292036 

Mesoscale discussion 1501 
National Weather Service Storm Prediction Center Norman OK 
0336 PM CDT Tuesday Jul 29 2014 

Areas affected...NE Minnesota into WI 

Concerning...severe potential...watch unlikely 

Valid 292036z - 292130z 

Probability of watch issuance...5 percent 

Summary...scattered thunderstorms will continue to track southeast 
from NE Minnesota across much of WI this afternoon. A few storms may 
briefly produce hail approaching 1 inch. A watch is not expected. 

Discussion...low-topped convection will continue to track S/southeast from 
the Minnesota arrowhead across much of WI this afternoon. Weak 
instability...bulk shear values less than 30 knots and poor midlevel 
lapse rates will limit thunderstorm organization and updraft 
intensity. A few storms may briefly produce marginally severe hail 
but the threat is expected to remain low. As such...a watch is not 

.Leitman/Goss.. 07/29/2014 

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


Latitude...Lon 48449250 46989007 45258775 44608738 43848758 43488800 
43188895 43338995 43689083 44339152 44969217 45949273 
46859297 47789325 48309307 48449250