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Area Forecast Discussion (AFD)

Issued by Little Rock, AR (LZK)

                            
000
FXUS64 KLZK 160542 AAA
AFDLZK

Area Forecast Discussion...UPDATED
National Weather Service Little Rock AR
1242 AM CDT Mon Sep 16 2019

.DISCUSSION...

Updated to include the 06Z aviation discussion below...

&&

.AVIATION...

Light and variable winds and high pressure should keep VFR
conditions dominant through this TAF period. 

&&

PREV DISCUSSION...(ISSUED 253 PM CDT Sun Sep 15 2019)

SHORT TERM...Tonight Through Tuesday

An upper level ridge continues over Arkansas stretching north into 
the Plains. Humberto is well off the Florida coast and is expected
to move east, away from land. The ridge will strengthen over the 
central U.S. through Tuesday. 

Surface high pressure will continue across the state Monday and much 
of Tuesday. A cold front may edge into northeast Arkansas Tuesday 
but no rain is anticipated at this time. Temperatures will remain 
above normal. Highs in the 90s are expected Monday and Tuesday.

LONG TERM...Tuesday Night Through Sunday

No major changes with this forecast update, shocking revelation I 
know. The story remains unchanged, the period begins with H500 high 
centered over Arkansas resulting in large scale subsidence promoting 
above average temperatures and next to no precipitation chances 
through much of the upcoming week. Upper level changes do appear on 
the horizon as early as Friday as a large trough traverses the 
Rockies. With the approach of this trough, model consensus suggest 
the upper level ridge will begin to shift eastward towards the 
Carolinas. 

The GFS is a little more amplified, progressive, and stronger with 
this pattern and brings a shortwave closer to AR, however the ECMWF 
and Canadian are more subtle in its wave pattern characterized as a 
flattening trough extending from the Rockies towards the Great 
Lakes. How this eventually plays out is the GFS brings a stronger 
surface cold front towards the state a little quicker whereas the 
ECMWF brings a weaker front towards the state several days later. 
Lastly, the Canadian stalls the front out completely before ever 
entering northwestern AR. The last two aforementioned models 
maintains some H500 troughing just south of AR keeping the front at 
bay. With either of these three cases, the frontal boundary 
approaches/nears/enters northwestern AR just beyond the forecast 
period. 

At this time will trend towards the ECMWF's warmer drier solution as 
it has better captured high/low temperature pattern of late. In 
either of these cases, precipitation chances will be on the increase 
across the northwestern portion of the state in response to an 
approaching front and the ingestion of tropical moisture from the 
southern TX interacting with the front. Chances will remain low 
attm as confidence in any given scenario is inherently low.  

At the surface, winds will remain southerly on the western periphery 
of high pressure displaced just to our east. This will help to 
ensure above average temperatures continue through the long term. 
Temperatures will remain well above average with readings in the 90s 
for highs and 60s and 70s for lows. Afternoon heat indices will be 
in the upper 90s to lower 100s.

&&

.LZK Watches/Warnings/Advisories...NONE.
&&

$$

Aviation...62