Winter Weather in Arkansas, January 6, 2017

Area Forecast Discussion...UPDATED
National Weather Service Little Rock AR
946 PM CST Thu Jan 5 2017

.UPDATE...
Surface front is well south of the region at this time. However,
ascent will continue north of the 850 millibar front, with
precipitation developing into Oklahoma and Arkansas later tonight
as an upper level system interacts with it.

On the whole, the forecast still looks pretty good. Axis of
heaviest snowfall should still be across the central third of
Arkansas, with one to two inches likely. Some totals around three
inches or more could occur in the higher terrain of the Ozarks and
Ouachitas.

Have made some minor adjustments upward (generally a few tenths of
an inch) in the higher elevations, and also across southeast
Arkansas, as a 700 mb wave pushes into that area during the
afternoon Friday.

Have also added two counties to the Winter Weather Advisory, and
will let the mid shift decide if any others should be added.
&&

.PREV DISCUSSION...(ISSUED 516 PM CST Thu Jan 5 2017)

AVIATION...
Prevailing conditions will gradually deteriorate to MVFR later
this evening, as light snow develops. This should persist through
the remainder of the period, though it will fluctuate back to vfr
every now and then. winds will be north/northeasterly around 7 to
8 knots or less, except a little higher in the southeast during
the day Friday. TAFS already out.

PREV DISCUSSION...(ISSUED 219 PM CST Thu Jan 5 2017)

SHORT TERM...Tonight Through Sunday

Cold and cloudy conditions are ongoing across the CWA this Thu
afternoon...with only some very light precip noted this morning as
far south as Little Rock in the form of snow flurries. This
afternoon...most areas are dry...though far NRN AR will continue to
see some potential for light snow or flurries this afternoon. Temps
have remained in the 20s and 30 so far this afternoon...with only
some slightly warmer temps expected for highs today.

This evening...dry conditions should remain across a good portion of
the state...with only some isolated flurries possible this evening.
That will change late in the evening and especially by around
sunrise Fri morning. Cold and dry air will continue to filter into
the state from the north...but after midnight...an upper level
disturbance will approach from the west. This disturbance will be
strong enough to see some snowfall across portions of the CWA during
the morning hrs Fri. The disturbance remains fairly weak...but there
will be enough gradual isentropic upglide in the dendritic growth
zone to generate an area of snow.

The latest timing shows snow starting to fall across WRN AR by
around midnight...then spreading into central sections of AR by
before sunrise Fri morning. Will then see snow taper off by mid
morning to early afternoon from NW to SE...then east of the entire
CWA by around sunset. The heaviest snow looks to fall between 3 am
and 3 pm.

Temps through the entire column will be sub-freezing...so that there
will be little chance for a mix precip event. In fact...temps at the
onset of precip will likely be in the mid to upper 20s...with dry
enough air near the SFC to see temps drop further shortly after snow
begins due to evaporative cooling. As a result...temps will likely
remain in the low to mid 20s during the snowfall. Given such cold
temps...should see the snow/liquid ratios higher than usual...on the
order of 12 to 18/1 snow/liquid. With these high snow/liquid
ratios...and well below freezing SFC temps...snow will likely take
little effort to stick on roadways across the area...with hazardous
travel conditions expected. As a result of this...and with being the
first accumulating snowfall this season...will post a Winter Wx Adv
for the areas roughly along the I-40 corridor across the entire
CWA...from 9Z-21Z.

Will point out however...uncertainty remains on the location of
heaviest snowfall...and the overall storm totals. Most near term
model guidance has shifted the axis of heaviest snowfall further
north today...with a few near term models holding steady with the
further south solutions. As a result...have trended a bit further
north with the heavier snowfall axis...but not as far north as some
solutions suggest at this time. Have also seen an increase in
overall QPF in the latest model guidance. With the higher QPF and
with snow/liquid ratios expected to be higher...have bumped the
forecast snowfall amounts higher than earlier forecasts. Have gone
with a swath of 1 to 2 inches of snow from WRN AR through central
AR...then just south of the I-40 corridor east of LIT. Some locally
higher amounts could be seen...especially in the higher terrain in
WRN AR. Given the continued uncertainty...the axis of heaviest
snowfall could still change...shifting moving a bit further north or
south. As a result...residents are urged to refer to the latest
forecast this evening and into the early morning hrs.

Expect dry and cold conditions for Fri night into Sat morning...with
lows in the teens and 20s. Temps may dip even further where the
heaviest snow falls. High pressure will move over the state on Sat
into Sat night...with another cold nigh expected. SRLY flow will
return by Sun...with a warming trend expected into the long term
period.

LONG TERM...Sunday Night Through Thursday

The extended forecast will start with a deep upper low pressure
trough over the eastern US, with a northwest upper flow into the
region. Surface high pressure was off to the east of AR and a south
wind flow was coming back to AR.

Dry weather conditions with moderating temperatures are forecast on
Monday. Monday night to Tuesday, a better south flow sets up into
AR with increasing moisture, as the upper pattern becomes more zonal
to southwest. A warm front lifts across AR and chances of rain
develop over the state. Gradually a cold front moves through the
state late Tuesday to early Wednesday which will clear the rain out
of AR. Generally dry for Thursday with temperatures above normal
with an upper ridge over the region.

Temperatures in the extended will start below normal, then warm to
at of above normal through Thursday.

&&

.LZK Watches/Warnings/Advisories...
Winter Weather Advisory until 3 PM CST Friday FOR Clark-Conway-
Faulkner-Garland-Hot Spring-Johnson-Logan-Montgomery-Newton-
Perry-Pike-Polk-Pope-Pulaski-Saline-Scott-Searcy-Van Buren-Yell.

Winter Weather Advisory from 6 AM to 3 PM CST Friday FOR
Arkansas-Cleburne-Cleveland-Dallas-Grant-Jefferson-Lincoln-
Lonoke-Monroe-Prairie-White-Woodruff.

&&

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HAZARDOUS WEATHER OUTLOOK...UPDATE
NATIONAL WEATHER SERVICE LITTLE ROCK AR
955 PM CST THU JAN 5 2017

ARZ003>007-012>016-021>025-030>034-037>047-052>057-062>069-061100-
BOONE-MARION-BAXTER-FULTON-SHARP-NEWTON-SEARCY-STONE-IZARD-
INDEPENDENCE-JOHNSON-POPE-VAN BUREN-CLEBURNE-JACKSON-LOGAN-CONWAY-
FAULKNER-WHITE-WOODRUFF-SCOTT-YELL-PERRY-POLK-MONTGOMERY-GARLAND-
SALINE-PULASKI-LONOKE-PRAIRIE-MONROE-PIKE-CLARK-HOT SPRING-GRANT-
JEFFERSON-ARKANSAS-DALLAS-CLEVELAND-LINCOLN-DESHA-OUACHITA-CALHOUN-
BRADLEY-DREW-
955 PM CST THU JAN 5 2017

THIS HAZARDOUS WEATHER OUTLOOK IS FOR A LARGE PART OF ARKANSAS.

.DAY ONE...TONIGHT

A STRONG UPPER LEVEL DISTURBANCE WILL MOVE INTO THE STATE TONIGHT
WITH WIDESPREAD SNOW EXPECTED. THE SNOW WILL BEGIN OVER WESTERN
ARKANSAS AFTER MIDNIGHT AND SPREAD INTO CENTRAL AND EASTERN SECTIONS
THROUGH THE MORNING WITH SOME ACCUMULATION LIKELY. WINTER WEATHER
ADVISORIES REMAIN IN EFFECT.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

LIGHT SNOW WILL BE ONGOING AFTER DAYBREAK FRIDAY AND WILL CONTINUE
THROUGH THE MORNING BEFORE STARTING TO TAPER OFF FROM WEST TO EAST
DURING THE LATE MORNING TO EARLY AFTERNOON HOURS. WHEN THE SNOW DOES
FINALLY END...WE ARE EXPECTING A SWATH OF 1 TO 2 INCHES ACROSS
CENTRAL SECTIONS OF THE STATE WITH LESSER AMOUNTS BOTH TO THE NORTH
AND SOUTH. THERE COULD BE SOME LOCALLY HIGHER AMOUNTS IN THE
OUACHITA AND OZARK MOUNTAINS.

IT WILL REMAIN ON THE COLD SIDE AFTER THE SYSTEM MOVES THROUGH SO
THE SNOW WILL LIKELY BE STICKING AROUND FOR AT LEAST 24 HOURS. WITH
THIS BEING THE FIRST ACCUMULATING SNOW OF THE SEASON...EXERCISE
EXTREME CAUTION IF OUT AND ABOUT TONIGHT AND FRIDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

&&

VISIT NWS LITTLE ROCK ON THE WEB. GO TO HTTP://WEATHER.GOV/LZK.

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