Area forecast discussion
National Weather Service Springfield MO
641 PM CDT Monday may 20 2013
..mesoscale discussion update on severe weather this evening...
Mesoscale discussion...
issued at 640 PM CDT Monday may 20 2013
Severe storms are occurring across the region this evening. Storms
have developed from central Missouri to the southwest across
western Missouri into northeastern Oklahoma. These storms are
are developing into line segments.
Low level shear has increased over the area as a low level jet has
increased across the region. Despite the cloud cover today...the
very moist airmass is still resulting in an unstable airmass as ml-
cape values are generally in the 2000 to 3000 j/kg range ahead of
the storms. 0-1km bulk shear values have increased into the 25 to 30kt
range ahead of the line. The instability supports a strong
damaging wind risk with winds in excess of 70 to 80 miles per hour with any
bowing segments that develop with the line segments this evening.
In addition to The Straight line wind risk 0-3km bulk shear values
are 35 to 45kt. Any line segments that Bow to the east to
northeast would support balance and mesovortices development and
tornadoes developing within the line surges this evening across
the entire area.
&&
Short term...(this afternoon through Tuesday night)
issued at 310 PM CDT Monday may 20 2013
The active weather pattern will continue this afternoon into
Tuesday as a strong storm system interacts with a very moist and
unstable airmass. A cold front extends across eastern Kansas into
central Missouri this afternoon. Storms are developing along the
front from west central Missouri down to central Missouri this
afternoon. Instability and deep layer shear are resulting in these
storms being supercellaur in nature.
Cloud cover has remained over the area all afternoon and
temperatures have remained in the 70s. The clearing line is
surging across northeastern Oklahoma and temperatures are quickly
jumping into the 80s once behind the clearing line. The clearing line
will surge into extreme southeastern Kansas and southwestern
Missouri in the next couple hours and will see temperatures
quickly warm into the 80s. Expect the storms across Oklahoma to
track northeast. Hail to the size of hen eggs and tornadoes will
be possible with any supercells and there is the potential for a
strong tornado again if the clouds can clear and temperatures warm
into the 80 late this afternoon into early this
evening. This potential seems to generally be along and south of
Interstate 44 and west of Highway 65.
A line of storms should develop and sweep across the region this
evening into the overnight hours. Winds to 70 miles per hour will be
possible. Given the low level shear in place there will also be
the potential for mesovortices tornadoes within any Bow sections
in any line of storms that develop.
Models show a boundary setting up over southern Missouri tonight...and
with the low level jet tonight could see round of storms track
over the same locations into the overnight hours with very heavy rain
and flash flooding possible.
Storms may linger into Tuesday morning. Additional storms may
develop across the Eastern Ozarks Tuesday afternoon and evening as
the cold front moves through the area. The area will be worked
over from today and tonights storms and shear will not be as
strong. Depending on how much instability that can develop there
could be a severe hail risk this Tuesday afternoon.
Long term...(wednesday through monday) issued at 310 PM CDT Monday
may 20 2013
The upper level low that has brought the active weather to the
region through Tuesday will finally kick off to the east on
Wednesday and upper level ridging will build over the central US
through the weekend. This will bring more seasonable temperatures
to the region through the long term period. A few weak disturbance
may ride through the ridge and bring scattered showers and
thunderstorms to the region this weekend.
&&
Aviation...(for the 18z tafs through 18z Tuesday afternoon)
issued at 1255 PM CDT Monday may 20 2013
A MVFR cloud deck is currently over the area early this afternoon.
The clouds should cover and expect VFR ceilings to develop later
this afternoon into the overnight hours. A few shower or storms
may develop early this afternoon but the better potential is late
this afternoon into this evening. There could be multiple rounds
into of storms persisting into the overnight hours. IFR
visibilities will be possible within any thunderstorms. These
storms will also have the potential to become strong to severe
with heavy rainfall overnight.
&&
Sgf watches/warnings/advisories...
MO...Flash Flood Watch through Tuesday morning for moz055>058-066>071-
077>083-088>098-101>106.
Kansas...Flash Flood Watch through Tuesday morning for ksz073-097-101.
&&
$$
Mesoscale...wise
short term...wise
long term...wise
aviation...wise
