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Area forecast discussion 
National Weather Service Memphis Tennessee
1216 PM CDT Tuesday Aug 4 2015


Updated aviation discussion for 18z tafs...


Previous discussion... /issued 1018 am CDT Tuesday Aug 4 2015/

temperatures have warmed quickly today...adjusted afternoon highs
up a degree or too area wide. Convective temperatures appear to be
in the low to middle 90s on surrounding area soundings...only a
couple degrees warmer than we are currently at most locations.
Short range high resolution guidance shows some development over
the next couple of hours. Will go ahead and all isolated
thunderstorms to the forecast...but not yet convinced we will see
enough coverage to justify much higher probability of precipitation.

Previous discussion... /issued 633 am CDT Tuesday Aug 4 2015/

updated for 12z aviation discussion below.

Previous discussion... /issued 434 am CDT Tuesday Aug 4 2015/

Discussion...09z surface analysis places a quasi-stationary
boundary across portions of Kansas...southeast Missouri...southern
Illinois and into Kentucky. Water vapor satellite trends this
morning indicates an upper level ridge axis centered over the
southwest United States and Southern Plains. The middle south still
remains under the influence of the upper level ridge axis this
morning but on the eastern periphery of the ridge. As of 4 am
CDT...high clouds are producing partly cloudy skies across the middle
south with temperatures in the 70s at most locations.

Short term...(today through thursday)...the aforementioned upper
level ridge axis is expected to remain in place across the middle
south during the day keeping the middle south mainly rain free. High
temperatures this afternoon will rise into the upper 90s at most
locations with lows tonight in the 70s. Short term model trends
indicate the ridge will begin to weaken and retrograde tonight
into Wednesday...resulting in northwest flow aloft developing
across the lower Mississippi Valley. A middle level shortwave trough
is expected to move across portions of the middle/lower
Mississippi valleys tonight resulting in the development of
showers and thunderstorms...especially late tonight west of the
Mississippi River. Showers and thunderstorm chances are expected
to spread across the remainder of the middle south on Wednesday with
the best chances occuring Wednesday night into Thursday as the
quasi-stationary boundary over Missouri drifts south into the middle
south. A few strong to perhaps isolated severe thunderstorms are
possible Wednesday afternoon into Wednesday night...especially
north of I-40. Convective activity and increased cloud cover
should result in highs being slightly cooler on Wednesday and

Long term...(friday through monday)...long term models indicate
the quasi-stationary boundary will move north of the area next
weekend as the upper level ridge gradually builds back east into
the lower Mississippi Valley. As a result...chances for showers
and thunderstorms will become increasingly isolated especially
towards the latter half of the weekend into early next week.


Aviation...18z tafs

VFR conditions and light winds will continue through the period at
all taf sites. Some fog down to 4sm is possible at mkl and tup
overnight with clearing expected by 14z on Wednesday. Chances for
showers and thunderstorms will increase through the day on
Wednesday as well...first at jbr then spreading east-southeast
after 18z.



Meg watches/warnings/advisories...


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