Area Forecast Discussion
Issued by NWS Mobile, AL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

000
FXUS64 KMOB 161126
AFDMOB

Area Forecast Discussion
National Weather Service Mobile AL
526 AM CST Tue Jan 16 2018

.DISCUSSION...Updated for latest aviation discussion below.

&&

.AVIATION...
12Z issuance...MVFR ceilings gradually move in this morning ahead
of a cold front. The frontal passage occurs from northwest to
southeast late this morning through this afternoon, with winds in
its wake increasing to around 15 knots with higher gusts. Some
light showers, transitioning to a wintry mix, will be possible
along and behind the front this afternoon and evening. Skies then
gradually clear late tonight, with VFR conditions returning
across much of the area towards the end of this forecast period.

/49

&&

.PREV DISCUSSION... /issued 511 AM CST Tue Jan 16 2018/

NEAR TERM /Now Through Tuesday night/...An amplifying upper level
trough over the Great Lakes rotates across the eastern CONUS
through the near term period. This pushes a strong cold front
southeast into the Deep South and through the local area late this
morning and afternoon. Expect today`s highs to be reached ahead
of this frontal passage, as temperatures in its wake will quickly
plummet with the onset of strong cold air advection. A broad area
of large-scale forcing associated with the upper trough will
support a band of precipitation following the frontal passage.
Model guidance continues to indicate these showers beginning as a
wintry mix of rain and snow, then quickly transitioning to all
light snow as temperatures fall below freezing. This band is
progged to reach our interior SE MS/SW AL counties early this
afternoon, the I-65 corridor between 6pm and midnight CST, and
eventually exit our area to the southeast late tonight. Only minor
snow accumulations are expected, with most only seeing up to half
an inch, though some inland areas could see isolated amounts up
to or just over an inch. A Winter Weather Advisory remains in
effect for all areas along and north of the I-10 corridor from
noon today until 6am CST Wednesday. Given the generally light
accumulations, not anticipating any significant travel impacts
from this system. That said, any localized heavier snow bands will
be capable of producing slick spots on roads, especially on
bridges and overpasses.

A bitter cold night is in store for areas that see skies clear in
the wake of the front. A Hard Freeze Warning is in effect starting
at midnight tonight, generally along and west of I-65 where low
temps will range from the mid teens to around 20 degrees. Elsewhere,
lingering cloud cover will mean lows in the low to mid 20`s. One
concern regarding these bitter temperatures is the potential for
black ice early Wednesday morning, as any residual moisture left on
roads will freeze and cause slick spots. Also, the combination of
these temperatures and north winds around 10 to 15 mph will result
in single digit wind chill values for much of the area. Thus, a Wind
Chill Advisory is in effect from midnight tonight until 11am CST
Wednesday. /49

SHORT TERM /Wednesday Through Thursday night/...A brisk northerly
wind will continue Wednesday into Wednesday night as a strong 1040
mb surface high pressure area settles across the lower Mississippi
River region. This high will then shift east across the southeast
states Thursday and Thursday night, bringing light and variable
winds to the area. A prolonged very cold air mass will persist
across the region through the short term. As a result, the Hard
Freeze Warning has been extended to include all zones Wednesday
night into Thursday morning. A Wind Chill Advisory will also
likely be required Wednesday night into Thursday morning.

The upper shortwave will move quickly east of the area Wednesday
and Wednesday evening, with a dry very cold air mass filtering
into the region from the north. This air mass will remain in place
through the remainder of the short term as upper flow becomes
zonal, keeping the area precipitation free.

High temperatures on Wednesday will struggle to reach just above
freezing by mid afternoon despite the sunny skies, ranging from
33 to 38 degrees. Again, these bitter temperatures may result in
the potential for black ice through early afternoon Wednesday, as
any residual moisture left on roads will freeze and cause slick
spots. Low temperatures Wednesday night will range from 13 to 18
degrees, and around 20 degrees at the beaches. Temperatures on
Thursday will reach the mid 40s, falling into the upper teens to
mid 20s overnight. /22

LONG TERM /Friday Through Monday/...The surface high pressure
will continue to move east across the western Atlantic late in the
week, but a trailing surface ridge will remain across the
southeast states. An upper level shortwave shortwave will exit the
Rockies on Saturday, and move east over the Great Plains on
Sunday. An associated surface low pressure area developing across
the Western High Plains late in the week will deepen and lift
northeast toward the western Great Lakes through Monday, while a
cold front approaches the region from the northwest. These
features will bring widespread rain back to the region early next
week, along with possible embedded isolated thunderstorms. /22

MARINE...A strong cold front pushes through the marine area this
afternoon, bringing increasing offshore flow and building seas late
today through Wednesday night. A Small Craft Advisory is in effect
from 3pm CST this afternoon until 6am CST Thursday. Winds and seas
then gradually diminish Thursday, with light east to southeast flow
developing by the weekend as high pressure builds over the eastern
Gulf. Onshore flow then strengthens late this weekend into early
next week as showers and thunderstorms return ahead of the next
approaching weather system. /49

&&

.MOB WATCHES/WARNINGS/ADVISORIES...
AL...Hard Freeze Warning from midnight tonight to 9 AM CST Thursday
     for ALZ051>059-261>264.

     Winter Weather Advisory from noon today to 6 AM CST Wednesday
     for ALZ051>060-261>264.

     Wind Chill Advisory from midnight tonight to 11 AM CST Wednesday
     for ALZ051>060-261>264.

     Hard Freeze Warning from 11 AM Wednesday to 9 AM CST Thursday
     for ALZ060-265-266.

FL...Hard Freeze Warning from midnight tonight to 9 AM CST Thursday
     for FLZ201.

     Winter Weather Advisory from noon today to 6 AM CST Wednesday
     for FLZ201-203-205.

     Wind Chill Advisory from midnight tonight to 11 AM CST Wednesday
     for FLZ201-203-205.

     Hard Freeze Warning from 11 AM Wednesday to 9 AM CST Thursday
     for FLZ202>206.

MS...Hard Freeze Warning from midnight tonight to 9 AM CST Thursday
     for MSZ067-075-076-078-079.

     Winter Weather Advisory from noon today to 6 AM CST Wednesday
     for MSZ067-075-076-078-079.

     Wind Chill Advisory from midnight tonight to 11 AM CST Wednesday
     for MSZ067-075-076-078-079.

GM...Small Craft Advisory from 3 PM this afternoon to 6 AM CST
     Thursday for GMZ630>636-650-655-670-675.

&&

$$

This product is also available on the web at:
http://weather.gov/mob



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.