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Area forecast discussion...updated 
National Weather Service Springfield MO
1155 PM CDT Mon Apr 20 2015

..updated aviation discussion...

Short term...(this evening through Tuesday night)
issued at 250 PM CDT Monday Apr 20 2015

Surface low pressure is located across the Great Lakes region this
afternoon as high pressure builds across the plains. As a result
gusty winds have occurred today as the pressure gradient was tight
between the low and high.

This evening and tonight the pressure gradient will relax as the
low pushes off to the east and surface low pressure moves into
central Arkansas. Lows will drop well into the 40s tonight and a
few locations may dip into the upper 30s. Winds will weaken
tonight but will not go claim as the high remains south of the
area. Winds should also remain high enough to limit frost from
developing tonight.

An upper level low located across northern Minnesota this
afternoon will push east into the Great Lakes region on Tuesday.
Energy from the low will spread southeast into the region Tuesday
afternoon and evening, sparking off scattered thunderstorms.
Instability will increase some with the heating of the day but
will still remain on the limited side. Given colder temperatures
aloft, a few strong to marginally severe storms with hail to the
size of quarters will be possible. Wind shear will be strong
enough to support a wind risk if any line of storms can develop.
However, Theta-east differences will be weak and may be tough to get
any cold pools to congeal into a line, and if they do they may be
shear dominant. Instability will decrease overnight Tuesday with
thunderstorm coverage decreasing.

Long term...(wednesday through monday)
issued at 250 PM CDT Monday Apr 20 2015

The area will remain in northwest flow during the middle of this
week with below normal temperatures, and highs in the upper 50s
to lower 60s, and lows in the 40s occurring both Wednesday and
Thursday. A cold front will move south through the area on
Wednesday and generate a few showers across the area as it moves
through the region. The front may try to move back to the north on
Thursday with showers again possible across southern Missouri, but
the better chances will remain south of the area on Thursday.

Shortwave upper level ridging will build over the region and will
likely result in the warmest day of the week on Friday as highs
warm into the middle to upper 60s. An upper level trough and
associated surface low will then track through the region Friday
afternoon into early Saturday and will bring better chances for
showers and a few thunderstorms to the area. No severe weather is
expected at this time.

Another upper level disturbance will track through the region
Sunday into Monday and will bring additional chances for showers
and thunderstorms to the area.


Aviation...(for the 06z tafs through 06z Tuesday night)
issued at 1154 PM CDT Monday Apr 20 2015

Quiet weather conditions are expected for the next 6 to 12 hours.
A clear sky will give way to an increase in mid/high level clouds
from west to east. Southwest winds will gradually increase through
the overnight hours. Heading into the daylight hours of Tuesday
morning, mixing will promote another day of gusty westerly winds.
A quick moving disturbance should spark scattered showers and
thunderstorms Tuesday afternoon. Previous forecast handled this
with prob30 groups. At this time, confidence has not increased and
have left the prob30 groups in tact for now. Future forecasts will
help hone the risk for showers/storms. If this activity can
develop, it should decrease in coverage Tuesday evening. At this
point low level wind shear will become an increasing concern.


Sgf watches/warnings/advisories...


Short term...wise
long term...wise

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