Severe Weather event East Texas / LA / Miss / Ala / GA - April 2 -3
Posted: Sat Apr 01, 2017 6:16 am
Valid 021200Z - 031200Z
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS SUNDAY ACROSS
MUCH OF SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA...
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS
SURROUNDING AREAS OF EASTERN TEXAS INTO WESTERN AND CENTRAL
LOUISIANA...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SURROUNDING
AREAS OF CENTRAL AND EASTERN TEXAS INTO THE LOWER MISSISSIPPI
VALLEY...
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS
SURROUNDING AREAS OF THE LOWER RIO GRANDE VALLEY...SOUTHEASTERN
PLAINS AND LOWER MISSISSIPPI VALLEY...
...SUMMARY...
Organized severe thunderstorm development is expected across parts
of eastern Texas into western and central Louisiana Sunday through
Sunday night. This includes a risk for tornadic supercells, a few
of which could be strong, along with considerable potential for
damaging wind gusts with an evolving squall line.
...Synopsis...
There remains little change to the general large-scale pattern with
a series of significant short wave perturbations emanating from a
strong mid/upper jet over the mid-latitude Pacific, before migrating
inland, and digging into/through the Southwest. One now is in the
process of advancing toward the British Columbia/Pacific Northwest
coast, and is forecast to progress inland, before digging through
parts of the northern intermountain region and California Sunday
through Sunday night. As this occurs, one or two vigorous
perturbations (digging into the base of elongating troughing near
the southern Rockies today) appear likely to accelerate east
northeast of the Rio Grande Valley.
Various model output, including the latest ECENS,NCEP MREF and SREF
mean fields appear to be coming into at least somewhat better
consensus concerning the evolution and progression of this latter
system. Confidence is increasing that the negatively tilted axis of
larger-scale troughing will reach the southeastern Plains/Sabine
Valley by 12Z Monday, supporting the development and northeastward
migration of a deepening surface low from portions of
central/northeast Texas into the Ozark Plateau.
All indications continue to suggest that this will be favorably
timed with an increasingly substantive return flow of moisture off
the Gulf of Mexico, including surface dew point increases through
the 60s to around 70f across the mid/upper Texas and southwest
Louisiana coastal plain. In the presence of steep mid-level lapse
rates, sizable mixed layer CAPE may exceed 2000 J/kg across this
region by Sunday morning. Destabilization is expected to coincide
with strengthening of lower/mid tropospheric wind fields, including
30-50 kt (southerly) at 850 mb and 50-70 kt (west southwesterly) at
500 mb, across central and eastern Texas into the lower Mississippi
Valley.
...Southeastern Plains into northwestern Gulf coast region...
Aforementioned warm sector environment conditions appear more than
favorable for organized severe storm development, in the presence of
increasing large-scale forcing for ascent. Timing of initiation of
intense boundary layer based storm development remains somewhat
unclear, but it appears possible as early as Sunday morning in the
presence of low-level warm advection across southeast Texas. This
activity may be mostly discrete in nature, in the presence of
moderately large CAPE, strong deep layer shear and sizable
clockwise-curved low-level hodographs. Evolving supercells are
expected to be accompanied by the risk for tornadoes, a few of which
may be strong.
Discrete supercell development may persist through the afternoon
hours, and perhaps the remainder of the period, spreading toward the
lower Mississippi Valley, ahead of an evolving convective system
which may be accompanied by a considerable risk for potentially
damaging wind gusts. Portions of central and eastern Texas into
Louisiana still appear the mostly likely areas that could be
impacted by an evolving convective system, but northeastward
development into portions of the Ozark Plateau and adjacent
Mississippi Valley may not be out of the question by late Sunday
night.
..Kerr.. 04/01/2017
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS SUNDAY ACROSS
MUCH OF SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA...
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS
SURROUNDING AREAS OF EASTERN TEXAS INTO WESTERN AND CENTRAL
LOUISIANA...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SURROUNDING
AREAS OF CENTRAL AND EASTERN TEXAS INTO THE LOWER MISSISSIPPI
VALLEY...
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS
SURROUNDING AREAS OF THE LOWER RIO GRANDE VALLEY...SOUTHEASTERN
PLAINS AND LOWER MISSISSIPPI VALLEY...
...SUMMARY...
Organized severe thunderstorm development is expected across parts
of eastern Texas into western and central Louisiana Sunday through
Sunday night. This includes a risk for tornadic supercells, a few
of which could be strong, along with considerable potential for
damaging wind gusts with an evolving squall line.
...Synopsis...
There remains little change to the general large-scale pattern with
a series of significant short wave perturbations emanating from a
strong mid/upper jet over the mid-latitude Pacific, before migrating
inland, and digging into/through the Southwest. One now is in the
process of advancing toward the British Columbia/Pacific Northwest
coast, and is forecast to progress inland, before digging through
parts of the northern intermountain region and California Sunday
through Sunday night. As this occurs, one or two vigorous
perturbations (digging into the base of elongating troughing near
the southern Rockies today) appear likely to accelerate east
northeast of the Rio Grande Valley.
Various model output, including the latest ECENS,NCEP MREF and SREF
mean fields appear to be coming into at least somewhat better
consensus concerning the evolution and progression of this latter
system. Confidence is increasing that the negatively tilted axis of
larger-scale troughing will reach the southeastern Plains/Sabine
Valley by 12Z Monday, supporting the development and northeastward
migration of a deepening surface low from portions of
central/northeast Texas into the Ozark Plateau.
All indications continue to suggest that this will be favorably
timed with an increasingly substantive return flow of moisture off
the Gulf of Mexico, including surface dew point increases through
the 60s to around 70f across the mid/upper Texas and southwest
Louisiana coastal plain. In the presence of steep mid-level lapse
rates, sizable mixed layer CAPE may exceed 2000 J/kg across this
region by Sunday morning. Destabilization is expected to coincide
with strengthening of lower/mid tropospheric wind fields, including
30-50 kt (southerly) at 850 mb and 50-70 kt (west southwesterly) at
500 mb, across central and eastern Texas into the lower Mississippi
Valley.
...Southeastern Plains into northwestern Gulf coast region...
Aforementioned warm sector environment conditions appear more than
favorable for organized severe storm development, in the presence of
increasing large-scale forcing for ascent. Timing of initiation of
intense boundary layer based storm development remains somewhat
unclear, but it appears possible as early as Sunday morning in the
presence of low-level warm advection across southeast Texas. This
activity may be mostly discrete in nature, in the presence of
moderately large CAPE, strong deep layer shear and sizable
clockwise-curved low-level hodographs. Evolving supercells are
expected to be accompanied by the risk for tornadoes, a few of which
may be strong.
Discrete supercell development may persist through the afternoon
hours, and perhaps the remainder of the period, spreading toward the
lower Mississippi Valley, ahead of an evolving convective system
which may be accompanied by a considerable risk for potentially
damaging wind gusts. Portions of central and eastern Texas into
Louisiana still appear the mostly likely areas that could be
impacted by an evolving convective system, but northeastward
development into portions of the Ozark Plateau and adjacent
Mississippi Valley may not be out of the question by late Sunday
night.
..Kerr.. 04/01/2017
