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Area forecast discussion...updated 
National Weather Service Little Rock Arkansas
616 am CDT Friday Aug 22 2014

Aviation...
this morning...there is some fog at adf...and lower clouds near
bodies of water. Other than a tempo group at adf...VFR conditions
will prevail. Southwest winds will be gusty this
afternoon...before decreasing after sunset. With light winds this
morning...some low level wind shear across the north and west through 14z.
&&

Previous discussion... /issued 301 am CDT Friday Aug 22 2014/

Discussion...

Main concerns this forecast cycle continue to be the hot and humid
weather conditions...and corresponding heat index values. A
Special Weather Statement has been issued last two days...and one
will be issued today. Over the weekend...a possible heat advisory
may be needed. Finally overall chances of convection will remain
low as the upper high pressure ridge holds over the region.

Surface high pressure is centered to the south of Arkansas and the south
wind flow has kept moisture levels up. Dew point temperatures were mainly
in the lower to middle 70s. Precipitation water values around the
region were from 1.25 inches to near 1.50 inches. Sounding data
does continue to show dry air through the atmosphere and have seen
the last two days good mixing in the afternoon...lowering surface
dew point temperatures into the 60s. This has kept heat index values in
the 90s to less than 105 degrees the last two days...and expecting
the same today. A few locations will see heat index values of 100
to around 105 degrees...hence a special statement will be issued
and highlighted in the severe weather potential statement. Otherwise...aloft the upper ridge
was holding over Arkansas...keeping any significant short wave energy
well north of the state. On Thursday...did see a few isolated
storms over far southern Arkansas...but not expecting any today.

Short term...today through Monday night

Again a mostly sunny...dry and hot day is expected. Highs temperatures
held at a similar level Thursday and Wednesday...while today
expect just a degree or two higher due to the building upper ridge
and higher morning low temperatures. Due to the available ground and
vegetation moisture...due to Summer time rains over Arkansas this year...
temperatures have not warmed as quickly as expected and guidance trends.
It will take another day or two...to reach the middle and upper 90s
over Arkansas...while heat index values rise a few more degrees closer
to the 105 and above degree mark. Today will see heat index
values a few degrees higher than Thursday...but still keep levels
below advisory criteria. Hence will issue statement highlighting
heat and humidity.

Little change in the forecast over the weekend. The upper ridge
holds over the region...centered just to the south of Arkansas to over
Arkansas...keeping short wave energy away from Arkansas...and keeping the
forecast hot and dry. The south winds will also hold today and
over the weekend...keeping moisture levels up and dew point temperatures
in the 70s. The south winds will be elevated a bit in the
afternoon and give some relief in the heat. High temperatures will nudge
up to the middle and upper 90s over the weekend with a few locations
near 100 degrees...while keeping heat index values from the upper
90s to around 105 degrees. Some areas at some point will see heat
index values over 105 degrees...and a heat advisory may be needed
over the weekend. Also an isolated shower or storm may form during
the heat of the day...but chance will be quite low and not
included in the forecast.

Long term...Tuesday through Thursday

Guidance is coming into better agreement with ridge slowly
breaking down...although there are timing differences between the
models. The GFS brings upper trough into the region much quicker
than the European. Guidance is usually too quick with pattern
changes...and have trended more with the Euro.

Models are also showing Gulf moisture moving north...and have kept
small rain chances in the forecast. With the increased cloud cover
and ridge breaking down...temperatures will be a couple of degrees
cooler...with heat index values falling a little as well.
&&

Lzk watches/warnings/advisories...none.
&&

$$

Aviation...58

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