River Flood Warning 54, NWS Mobile, AL

Area Forecast Discussion
National Weather Service Mobile AL
606 AM CST Sat Dec 21 2019

.DISCUSSION...See updated information for land areas and aviation
discussion below.

&&

.UPDATE...In conjunction with a high risk of rip currents, surf
heights are expected to reach between 4 and 6 feet later today
and persist through Sunday night. Therefore, a High Surf Advisory
was issued and is in effect from 4PM this afternoon through Sunday
night. /26

&&

.AVIATION...
12Z issuance...VFR conditions were observed at all TAF sites at
issuance, along with light rain showers. Showers will increase in
intensity area-wide through the day today, with the heaviest
showers expected overnight tonight into tomorrow morning as a
surface low pressure system progresses over the northern Gulf.
With this, expect lowering VIS and IFR CIGs, especially overnight
during the heavier showers. Furthermore, sustained northeast winds
will generally be between 10 and 15 knots, with gusts around 20
knots expected at BFM and PNS later today through tonight. /26

&&

.PREV DISCUSSION... /issued 504 AM CST Sat Dec 21 2019/

NEAR/SHORT TERM /Now Through Sunday/...Little change from the
previous forecast package is expected this morning with main upper
low approaching from the west deepening over the lower MS River
Valley and north central Gulf states later today through early Sun
afternoon, merging with a rapidly developing surface low located
over the north central gulf tracking north northeast towards the
FL Panhandle through Sunday. The GFS and ECMWF still showing
subtle differences with the track of this system with the Euro
guidance favoring a better track further to the west resulting in
slightly better precip and wind impacts to the forecast area later
today through Sunday afternoon. As the system to the south begins
to intensify rapidly later this morning widespread isentropic
lift or overrunning will become much better organized on the
northern side of the low leading to widespread light to moderate
rain spreading northward towards the coast later this morning
quickly spreading inland and becoming heavy at times due to better
dynamically forcing approaching from the west, covering most of
the forecast area late this afternoon and tonight. Similar to
earlier runs current model guidance continues to show moderate to
occasional rainfalls rates with this pattern later today through
Sunday morning then slowly shifting eastward by Sun afternoon.
Rainfall totals from 2 to 4 inches area wide can be expected with
locally higher amounts possible especially over eastern and
coastal sections of the forecast area late tonight through Sun
morning. As result some minor flooding will be possible overnight
and Sun morning especially in areas with poor drainage. At this
time we are not anticipating widespread flash flooding with this
system due to current antecedent conditions across the region and
the forward progression with the main upper system over the
weekend.

With the surface low remaining mostly to the south of most land
areas in the forecast area through Sun conditions will remain on
the cool side over the weekend. Highs today and Sun will range
from the lower to middle 50s for most inland areas and the middle
to upper 50s along the immediate coast. Lows tonight will range
from the middle to upper 40s for most inland areas generally
north of the I-10 corridor and the upper 40s to lower 50s to the
south. 32/ee

LONG TERM /Sunday night Through Friday/...The long term period
will begin with an upper level cutoff low centered over eastern
Louisiana, southeast Mississippi, and southwest Alabama. The
models are in fair agreement with this upper level pattern as a
whole; however, the ECMWF does show the center of the low tracking
a bit further north whereas the GFS more eastward in relation to
Mobile, Alabama. This low will continue to progress to the east
until it moves off into the Atlantic by Tuesday evening. By this
time, a ridge will build over the southeastern CONUS from the west
through late week. A deep trough will then develop over the
southwestern CONUS by Friday and begin to advance eastward towards
the eastern CONUS.

At the surface, a low pressure system will begin to occlude over the
panhandle of Florida. This low will move northeast over Florida
through Monday before it quickly moves off over the Atlantic by
early Tuesday. Most of the shower activity is expected to occur over
the weekend. Thus, the majority of the shower activity will decrease
through the day Monday, with most of the showers coming to an end by
Monday evening. As high pressure builds in from the west, dry
conditions will then return to the area through midweek. By late
week, a cold front, associated with a low pressure system over the
Ohio Valley, will move southeast towards the region and bring the
potential for another chance at showers Friday afternoon and into
next weekend. The models are coming into better alignment with this
late week/weekend system. However, as this is at the tail-end of the
forecast, future model runs will continue to be monitored as the
event gets closer.

High temperatures will generally increase through the week, with
highs beginning in the lower 60s Monday. By Christmas Day highs will
warm to be in the upper 60s to around 70 degrees. This trend will
continue into Thursday as highs reach the lower 70s for most areas.
However, by Friday afternoon, a slight cool down is expected from
west to east as a cold front approaches the region. Temperatures in
the west will be in the upper 60s, with temperatures in the east
around 70 degrees. Low temperatures will also follow a warming
trend, starting out in the lower to upper 40s and increasing to
generally be in the lower 50s by Friday morning.

Lastly, there is Moderate Risk of Rip currents along the Gulf
beaches of Alabama and Northwest Florida Monday through Tuesday.
/26

MARINE...Gale conditions area expected over the open Gulf waters
of Alabama and Northwest Florida late today through early Sunday
morning in response to a strong upper level disturbance merging with
a developing surface low pressure system moving northward towards
the Northwest Florida coast. Seas up to 12 feet well offshore can
be expected tonight through Sunday. Widespread moderate to heavy
rain will cover much of the marine area late today through Sunday
morning. Winds and seas will begin slowly to subside late Sunday
into Monday as the main upper system shifts east to the northeast
Gulf. 32/ee

&&

.MOB WATCHES/WARNINGS/ADVISORIES...
AL...High Rip Current Risk through late Sunday night for ALZ265-266.

     High Surf Advisory from 4 PM this afternoon to 6 AM CST Monday
     for ALZ265-266.

FL...High Rip Current Risk through late Sunday night for FLZ202-204-
     206.

     High Surf Advisory from 4 PM this afternoon to 6 AM CST Monday
     for FLZ202-204-206.

MS...None.
GM...Small Craft Advisory from 4 PM this afternoon to 9 AM CST Sunday
     for GMZ630-633>636.

     Small Craft Advisory until midnight CST Monday night for GMZ631-
     632-650.

     Small Craft Advisory until 4 PM CST this afternoon for GMZ655-
     670-675.

     Small Craft Advisory from 9 AM Sunday to midnight CST Monday
     night for GMZ655-670-675.

     Gale Warning from 4 PM this afternoon to 9 AM CST Sunday for
     GMZ655-670-675.

&&

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

Hazardous Weather Outlook...UPDATED
National Weather Service Mobile AL
643 AM CST Sat Dec 21 2019

ALZ051>060-261>266-FLZ201>206-MSZ067-075-076-078-079-221245-
Choctaw-Washington-Clarke-Wilcox-Monroe-Conecuh-Butler-Crenshaw-
Escambia-Covington-Mobile Inland-Baldwin Inland-Mobile Central-
Baldwin Central-Mobile Coastal-Baldwin Coastal-Escambia Inland-
Escambia Coastal-Santa Rosa Inland-Santa Rosa Coastal-
Okaloosa Inland-Okaloosa Coastal-Wayne-Perry-Greene-Stone-George-
643 AM CST Sat Dec 21 2019

This Hazardous Weather Outlook is for portions of south central
Alabama...southwest Alabama...northwest Florida and southeast
Mississippi.

.DAY ONE...Today and Tonight

A High Rip Current Risk is in effect for coastal portions of
Alabama and the western Florida panhandle beginning 6:00 AM CST
Today.

A High Surf Advisory is in effect for coastal portions of Alabama
and the western Florida panhandle beginning 4:00 PM CST Today.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

A High Rip Current Risk is in effect for coastal portions of
Alabama and the western Florida panhandle until 6:00 AM CST
Monday.

A High Surf Advisory is in effect for coastal portions of Alabama
and the western Florida panhandle until 6:00 AM CST Monday.

.SPOTTER INFORMATION STATEMENT...

Please go to weather.gov/mob for additional information.

Activation of SkyWarn severe spotter networks is not expected
through Friday.

GMZ630>636-650-655-670-675-221245-
Northern Mobile Bay-Southern Mobile Bay-Mississippi Sound-
Perdido Bay-Pensacola Bay System-Western Choctawhatchee Bay-
Eastern Choctawhatchee Bay-
Coastal waters from Pensacola FL to Pascagoula MS out 20 NM-
Coastal waters from Okaloosa Walton County Line FL to Pensacola
FL out 20 NM-
Waters from Pensacola FL to Pascagoula MS from 20 to 60 NM-
Waters from Okaloosa Walton County Line FL to Pensacola FL from
20 to 60 NM-
643 AM CST Sat Dec 21 2019

This Hazardous Weather Outlook is for portions of the coastal
waters of Alabama and northwest Florida.

.DAY ONE...Today and Tonight

A Small Craft Advisory is in effect for northern Mobile Bay,
western Choctawhatchee Bay, eastern Choctawhatchee Bay, Perdido
Bay, Pensacola Bay System beginning 4:00 PM CST Today.

A Small Craft Advisory is in effect for the coastal waters from
Pensacola FL to Pascagoula MS out 20 NM, southern Mobile Bay,
Mississippi Sound beginning 6:00 AM CST Today.

A Small Craft Advisory is in effect for the waters from Pensacola
FL to Pascagoula MS from 20 to 60 NM, the western Florida waters
out 60 nm beginning 6:00 AM CST Today.

A Gale Warning is in effect for the waters from Pensacola FL to
Pascagoula MS from 20 to 60 NM, the western Florida waters out
60 nm beginning 4:00 PM CST Today.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

A Small Craft Advisory is in effect for northern Mobile Bay,
western Choctawhatchee Bay, eastern Choctawhatchee Bay, Perdido
Bay, Pensacola Bay System until 9:00 AM CST Sunday.

A Small Craft Advisory is in effect for the coastal waters from
Pensacola FL to Pascagoula MS out 20 NM, southern Mobile Bay,
Mississippi Sound until 12:00 AM CST Tuesday.

A Small Craft Advisory is in effect for the waters from Pensacola
FL to Pascagoula MS from 20 to 60 NM, the western Florida waters
out 60 nm until 4:00 PM CST Saturday.

A Gale Warning is in effect for the waters from Pensacola FL to
Pascagoula MS from 20 to 60 NM, the western Florida waters out
60 nm until 9:00 AM CST Sunday.

A Small Craft Advisory is in effect for the waters from Pensacola
FL to Pascagoula MS from 20 to 60 NM, the western Florida waters
out 60 nm beginning 9:00 AM CST Sunday until 12:00 AM CST
Tuesday.