Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Little Rock Arkansas
1255 PM CDT Tuesday Aug 30 2016
Aviation...30/18z taf cycle
VFR conds are expected thru much of the pd. Scattered-broken cumulus has formed
acrs the area since midday, with a few rain showers/thunderstorms and rain noted northern and western
Arkansas. Included thunderstorms in the vicinity in the fcst this aftn for these same areas, with
the activity diminishing arnd sunset. Expect patchy fog to again
form late tngt...with brief pds of MVFR vsby restrictions
Prev discussion.../ issued 315 am CDT Tuesday Aug 30 2016/
Main concerns in this forecast cycle chances of convection each
day and a temperature forecast.
Currently surface and upper high pressure ridging dominates the
weather pattern, while surface winds remain light and variable or
a light east flow, and surface dewpoint temperatures are from the
upper 60s to mid 70s. Convection on Monday occurred over parts of
southeast and west AR, and moved west through the afternoon to
evening, dissipating in the evening. Those areas that received
rain will be prone to fog formation this morning. The upper ridge
has centered itself more over the western Ohio to Tennessee valleys, and
will help temperatures warm to above normal values and hold
convection potential a bit lower today.
Short term...today through Wednesday night
Will see patchy fog this morning across AR, dissipating by mid-
morning. Partly to mostly sunny conditions will start the day,
then with the isolated convection mainly in the afternoon to
evening. Short range models are not showing a loft of lift moving
through the east flow today, but it also did not show much on
Monday and there was good scattered convection across the state.
So due to expected warm highs in the lower to mid 90s, while even
a few upper 90s, instability and moisture will be present for the
afternoon to early evening convection. Heat index values will
again be around 100 degrees, but below advisory levels. Will
mention in other public products. Tonight, dry with lows mostly in
the upper 60s to mid 70s. On Wednesday, convection chances will be
a bit higher over northern AR, as a prefrontal low pressure trough
sags into AR, ahead of the cold front that is expected late
Wednesday night to Thursday. Lows will again be from the upper 60s
to mid 70s.
Long term...Thursday through Monday
An upper level high pressure system will be over much of the U.S.
To begin the long term period with an upper low over the southeast
U.S.And over the Pacific northwest. An upper trough will dive into
the East Coast late Thursday and Friday as the the ridge
strengthens over Arkansas...which continues through Monday. The
West Coast trough will move to The Rockies by Sunday and Monday.
A cold front will enter north Arkansas Thursday and will move south
through the state. This will bring a chance of showers and
thunderstorms to mainly central and south sections of the state
Thursday. The front will work south and move out of the state
Thursday night. High pressure builds over the area behind the front
and will keep the forecast dry Friday through Monday. Tropical
depression 9 is expected to move northeast across North Florida
Thursday but should not affect the Arkansas weather.
Temperatures will be a bit cooler behind the front. Highs Thursday
through Saturday will be below normal...then back to near to above
normal Sunday and Monday.