Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Little Rock Arkansas
356 am CDT Sat Jul 12 2014
Short term...today through Tuesday night
The stalled boundary that had been situated across the state for
the last couple of days is now well north of Arkansas and high
pressure has settled in across the region. Skies have remained
clear overnight and as such conditions are primed for a quick warm
up today after sunrise. However the air mass is still quite rich
in moisture content and expect there to be a typical summertime cumulus
field develop early on today. Highs should be several degrees
warmer than yesterday...except for maybe in the west where they
were pretty warm on Friday...but did knock highs down a degree or
so from previous forecast. Split the difference between the cooler
GFS lamp guidance...and the mav/met MOS guidance. Additionally
there seems to be little capping inversion to prohibit convection
this afternoon in the eastern parts of the state. The best chances
look to be in the northeast...though high resolution models do
show some isolated convection scattered about most areas of the
eastern half of Arkansas. That said...limited precipitation mention to
the northeast and will let the day shift monitor radar trends and
amend if necessary.
Rain chances will be negligible in western Arkansas today...and
across the entire forecast area on Sunday as high pressure really
builds overhead. This strengthening high pressure aloft will also
further increase afternoon temperatures. Most areas should fall
somewhere between 94-97 degrees for a high Sunday...not at all
uncommon for July in Arkansas. However despite lack of triple
digit highs on Sunday...it will definitely be an oppressive heat.
Dewpoints will likely not mix out below 70 degrees Sun
afternoon and as such heat index values on Sun afternoon will fall
in the 100-104 range. Will not be issuing any heat advisory
products at this time as criteria will not be reached.
The unseasonably strong cold front set to usher in a much
welcomed cool down this coming week will not swing through until
late Monday night. As such Monday will still be an oppressively
hot and muggy day...especially in the southern half of the state.
Introduced some slight chance probability of precipitation in the far north during the day
Monday...but model guidance is not in the best agreement with
exactly how quick the rain will move in ahead of the front. The
best rain chances will be Tuesday...with widespread showers and
thunderstorms expected from early Tuesday morning through Tuesday night.
The big story however will be the unseasonably cool temperatures
that will accompany the front. Cloud cover and rainfall will limit
highs on Tuesday to the upper 70s to middle 80s for areas north of Hot
Springs and Pine Bluff...and only the upper 80s in southern
Arkansas. Tuesday night will be quite comfortable...with lows in the
upper 50s to middle 60s...with dewpoints mostly in the 50s.
Long term...Wednesday through Friday
Models have trended wetter versus this time last night setting
the stage for another round of potentially heavy rain. While the
medium range models are in general agreement overall...there are
still some timing differences concerning the onset and duration of
the precipitation. It should be noted these timing differences has
decreased and the models are now in about 6 hours of each other.
That being said...a blend of model solutions is preferred with a
slight lean towards the more consistent European model (ecmwf).
Period initiates with the cold frontal boundary that moved through
in the short term sitting along the Arkansas and Louisiana border.
Unseasonably deep upper trough will over the eastern Continental U.S. With deep
northwest flow over the nations middle section. Models are consistent
in moving a fairly significant upper level impulse through this flow
and interacting with the front. The result will be showers and
thunderstorms over mainly the southern half of the state starting as
early as Wednesday afternoon.
The best chances of rain appear to be setting up for sometime
Thursday but precipitation chances will need to be carried through
the remainder of the period. It appears that the heaviest rain
amounts will be over the south where several inches if rain can not
be ruled out where precipitable waters in excess of two inches will be pooling
along the boundary.
Temperates will continue to run well below normal through the
period although a very slight warming tend is expected as the period
progresses. Overall the mav/mex numbers look reasonable and are
Preliminary point temps/pops...
Batesville Arkansas 93 73 97 74 / 10 10 10 20
Camden Arkansas 96 73 98 75 / 10 10 10 10
Harrison Arkansas 92 70 94 72 / 10 10 10 20
Hot Springs Arkansas 95 73 97 75 / 10 10 10 10
Little Rock Arkansas 94 74 97 76 / 10 10 10 10
Monticello Arkansas 93 74 97 76 / 10 10 10 10
Mount Ida Arkansas 95 71 96 74 / 10 10 10 10
Mountain Home Arkansas 94 71 96 72 / 10 10 10 20
Newport Arkansas 92 73 96 74 / 10 10 10 20
Pine Bluff Arkansas 94 74 96 75 / 10 10 10 10
Russellville Arkansas 96 72 97 74 / 10 10 10 20
Searcy Arkansas 92 73 96 74 / 10 10 10 20
Stuttgart Arkansas 93 74 95 75 / 10 10 10 10
Short term...64 / long term...56