Area Forecast Discussion
Issued by NWS Springfield, MO
FXUS63 KSGF 131738
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1238 PM CDT Sun Apr 13 2014
Issued at 1025 AM CDT SUN APR 13 2014
Forecast evolving much as expected this morning. 12z NAM is
suggesting arrival into the SGF CWA to be 1-3 hours
slower...with development of strong to severe storms east of I35 over
eastern Kansas and Oklahoma toward 21z...reaching southeast Kansas
and western Missouri in the 23-01z time frame.
Convection currently most prevalent over northeast Oklahoma into
western Missouri ahead of approaching lead 700 MB shortwave
depicted over central Oklahoma at 12z but weakening as it moves
into eastern Oklahoma per water vapor at 14z. Obviously enough
jet support to lead to elevated convection though suspect this
activity to further weaken by late morning as low level jet
AC deck in behind 700 MB shortwave westward into western OK has
filled in a bit which may have a bearing on afternoon
instability...though RUC and 12z NAM lower RH satisfactory to lead
to 2000+ MLCAPE ahead of main 500 MB wave.
Lastly...wavy surface front extending from near STJ to SLN to TX
Panhandle with slug of low to mid 60 dew points surging northward
through central OK. Dew points though east of I-35 drop
considerable into the lower 50s over eastern OK. Lower dew points
wont help CAP evident ab 12z SGF RAOB...though MDCRS aircraft soundings
showing CAP weakening ahead of main shortwave.
.SHORT TERM...(Today through Monday)
Issued at 252 AM CDT SUN APR 13 2014
It is a very mild and breezy morning across southeast Kansas and
the Missouri Ozarks. Temperatures this morning are where our
normal highs would be for this time of year. Some convection is
already developing across portions of southeast Kansas this
morning. This will continue to further develop and move northward.
The 00z 4KM WFR model shows this development well and think that
the model has a good handle of the evolution of storms today and
this evening for the area.
All the 00z suite of models show convection developing by 18z
across southwestern Missouri into central Missouri in the warm
sector. Bulk shear will be up to 50 knots. Instability will
between 1000-1200 J/KG. 0-3KM Storm Relative Helicities will be
up to 500 M2/S2. This convection may be strong to severe with the
primary threats large hail and damaging wind gusts. There will be
a low potential for an isolated tornado or two mainly late this
afternoon into the early evening hours with the better potential
over southeast Kansas into extreme southwestern Missouri.
A strong to severe line of storms will be developing along the
advancing cold front by 00z across southeast Kansas into western
Missouri. The main threat again will be large hail and damaging
wind gusts. The front will slowly undercut the line of storms
through the evening hours as it advances southeastward. The front
will be through Springfield before Midnight and through the
eastern Ozarks before 6 am. Storm total rainfall will be around 1
inch with isolated amounts up to 2 inches.
.LONG TERM...(Monday through Saturday)
Issued at 252 AM CDT SUN APR 13 2014
Much colder air will be moving in on gusty northerly winds by
Monday morning. The main trough will be moving through the area by
the midday and early afternoon hours. Monday will be a shock
compared to the nice warm weather this weekend. Cloudy and dreary
conditions with north winds gusting up to 35 mph...off and on rain
showers with temperatures falling most of the day into the middle
and upper 30s...Wind chills will be in the 20s.
There is still indications from the models and forecast soundings
that enough cold air aloft will be available for either some wet
snow mixing in or changing over by late morning to midday on
Monday. The better potential for seeing wet snow falling will be
along and north of the I-44 corridor and the higher elevations of
the Ozark Plateau. No accumulations are expected with the warm
ground temperatures and the air temperatures will be in the middle
to upper 30s.
Skies will clear from west to east Monday evening and temperatures
will continue to drop as the Canadian high pressure moves in.
There is high confidence that most of the area will see
temperatures in the middle to upper 20s Monday night into Tuesday
morning. Some patchy to areas of frost may occur if the wind relax
enough and in sheltered areas. Will go ahead and issue a Freeze
Watch area wide for Monday night.
Temperatures will slowly moderate through the middle of the week.
May see another round of frost and near freezing temperatures
Tuesday night into Wednesday morning. Temperatures will be near
seasonable averages by Thursday before another trough and cold
front moves through and briefly cools temperatures back down for
the end of the week. A good chance of showers will accompanying
the cold front late Thursday into Friday.
.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 1225 PM CDT SUN APR 13 2014
We will continue to see scattered showers and storms over the
southwest Missouri airports through the afternoon...however we
expect ceilings to remain VFR ahead of the dry line and cold front
which extended across south central Kansas through central
Oklahoma at 17Z. A tight pressure gradient ahead of the front
should keep winds gusting above 20 mph through the afternoon.
Strong to severe thunderstorms could affect the airports roughly
from 23Z to 3Z...as the cold front moves across the area. These storms
could produce wind gusts in excess of 50 knots and hail to 1.75
inches in diameter.
Winds will shift to the west and southwest around midnight with
ceilings expected to drop to IFR through the night and into
tomorrow. We could see the ceilings break before 18Z Monday with
the passage of the 700 mb trough. Expect Springfield and Branson
to remain IFR with periods of light rain through 18Z.
MO...FREEZE WATCH from Monday evening through Tuesday morning FOR
KS...FREEZE WATCH from Monday evening through Tuesday morning FOR