Scientific Forecaster Discussion
fxus64 klzk 281721
Area forecast discussion
National Weather Service Little Rock Arkansas
1221 PM CDT Fri Jul 28 2017
best chances for thunderstorms and rain appear across central sections through 00z.
Surface flow will become north-northeasterly at <= 7 kts across
all sites by 03z.
Previous discussion...(issued 424 am CDT Fri Jul 28 2017)
Short term...today through Saturday night
The main forecast concerns for the short term are the rain chances
and hot temperatures (in the south) today, and of course the long
awaited cool down.
First let's talk about the heat in the south. The front that will
eventually push well into/through the state, is still located up
around the Missouri border. Convection will focus on and ahead of
this boundary today, which should leave far southern and
southwestern Arkansas rain free for the day. I say should because
much like yesterday, outflow boundaries from overnight and
morning convection could manage to spark off some isolated showers
and thunderstorms even in the southern parts of the state.
Mena made it to almost 100 degrees yesterday, and expect that
many places in southern and southwestern Arkansas will once again
reach the upper 90s today for highs if they do not see extensive
cloud cover or much in the way of convection. Due to the
uncertainty of realized heat index values and potential presence
of storms and/or cloud cover, will hold off on issuing a heat
advisory for those areas.
As far as rainfall is concerned, the central and northern half of
the state will be the focus for convection for much of the day.
However this will shift south as the day GOES on and the
aforementioned frontal boundary begins to pick up some speed on
it's way south. This evening and into the overnight hours will see
the south become the favored place for rainfall, although by that
time convection should begin to weaken. Expected precip amounts
are not overly impressive, but should be enough in many locations
to give the yard a good soak and stay the chore of watering your
Finally, the cool down. While temperatures in the northern half of
the state will be cooler today, the cooler and drier air is still
well north of Arkansas. You have to go clear into northern
Missouri or therabouts to find dewpoints lower than 70 degrees.
Thus it will be Saturday, and more specifically Saturday evening,
before the significant relief to the heat and humidity arrives.
But it is coming. This weekend will be nice, despite a still warm
day on Saturday. Lows in the 60s, and even some 50s up north, are
still expected Saturday night.
Long term...Sunday through Thursday
Summer will take a break in the in the extended period. A blocking
pattern is expected, with a ridge of high pressure over the
southwest United States and a large trough of low pressure over the
eastern states. This will result in a northwest wind flow aloft
Given the scenario, the main story will be cooler temperatures.
Readings will be 5 to 10 degrees below average toward the beginning
of the period, and will be closer to seasonal by the end of next
No major weather systems will be forthcoming. Other than a mention
of very spotty precipitation by Thursday, this is a mostly dry