- Day Three
acus02 kwns 141718
Storm Prediction Center ac 141717
Day 2 convective outlook
National Weather Service Storm Prediction Center Norman OK
1217 PM CDT Mon Oct 14 2019
Valid 151200z - 161200z
..there is a marginal risk of severe thunderstorms across portions
of southeastern Oklahoma...western Arkansas...northern
Texas...east-central Louisiana...southern Mississippi...southern
Alabama...southern Georgia...and the Florida Panhandle...
A couple of strong to severe thunderstorms are possible Tuesday
afternoon across parts of southeast Oklahoma, western Arkansas and
northeast Texas. Isolated strong to severe storms are also possible
across the deep south.
Modest mid-level height falls are expected across the southern tier
of the Continental U.S. Through the forecast period as a vigorous trough
amplifies over the upper Midwest. Westerly mid/upper flow will also
strengthen across the region as a result. In the low-levels, a
strong front will migrate southeastward across the plains, reaching
the OK/Texas Red River valley by evening. Low-level flow will also
strengthen across Alabama and Georgia in concert with an organizing
surface low in that area during the afternoon. A warm, moist
airmass (characterized by 70s f dewpoints) will reside from Texas
eastward to the South Carolina coast.
Models indicate the presence of an axis of mid-level clouds and
showers/isolated thunderstorms from North Texas eastward through
central Alabama through the afternoon. The extent of this activity
will modulate afternoon destabilization, casting some doubt on the
eventual evolution of convection along and ahead of the approaching
cold front. Nevertheless, where sufficient insolation can
destabilize the low-levels, unidirectional shear profiles orthogonal
to the initiating cold front and long hodographs (due to strong flow
aloft) will favor loosely organized convection and perhaps a couple
of supercells. Mid-level lapse rates are sufficient for hail in a
few storms, and an isolated severe-wind risk will exist with any
organized convection that can evolve during the afternoon across the
marginal risk area - especially with any upscale growth. This
threat should be primarily diurnally driven and lessen after sunset.
..east-central Louisiana eastward to southern Georgia...
An initial band of showers/isolated thunderstorms should reside on
the northern periphery of the marginal risk area much of the day.
South of this convection, surface heating will result in development
of weak, but sufficient instability for an increase in coverage and
intensity of storms during the afternoon in tandem with a gradually
deepening surface low over Alabama and Georgia. Low-level flow will
undergo modest strengthening and backing in response to the
cyclogenesis, which may Foster updraft rotation in more sustained
convection. Isolated damaging wind gusts and perhaps a brief
tornado may occur with this activity, though weak mid-level lapse
rates should limit the extent of the threat. Any severe risk should
be primarily diurnally driven and lessen after dark due to a
combination of convective overturning and nocturnal boundary layer
..maximum risk by hazard...
Tornado: 2% - marginal
wind: 5% - marginal
hail: 5% - marginal