Areal Flood Warning 15, NWS Mobile, AL

Area Forecast Discussion
National Weather Service Mobile AL
233 PM CDT Sun Sep 19 2021

.NEAR TERM UPDATE /Now Through Monday/...A weak upper level low
centered over the ARLATEX region will lift north-northeastward
through this evening, becoming centered over western Illinois by
midnight. However, the base of the upper shortwave that housed the
departing low will remain as far south as the northwest Gulf of
Mexico. This shortwave will eventually become broader and weaker
through the remainder of the near term as it moves very slowly
eastward over the lower Mississippi River region, and a longwave
trough digs southeast over the Northern Plains. PWATs will remain
from 1.9 to 2.2" through Sunday evening, and then gradually lower
from west to east to between 1.7 to 1.9" late Sunday night through
Monday afternoon.

Generally can expect a diurnally driven convective pattern with
offshore showers and thunderstorms during the overnight hours
gradually propagating onshore during the day, increasing in
coverage inland through the afternoon hours. We have already seen
an increase in convective coverage this morning along the coast,
and will continue to see this gradually spread inland as we head
into the afternoon hours. Showers and thunderstorms will be very
slow moving, to nearly stationary at times, and will continue to
pose a heavy rainfall threat. Given the antecedent saturated soil
moisture, heavy rainfall rates will result in excessive runoff and
potential for flash flooding. Given the overall limitation in
coverage of deep/intense convection, the flash flooding threat
should remain generally isolated. Convective coverage will
gradually decrease by the evening hours and continue to shift
inland to our far inland counties of southeastern MS and
southwestern AL. Highs today will generally be in the lower to
middle 80's.

Overnight tonight, at best isolated convective coverage is
expected with loss of daytime heating, and better coverage
diurnally shifts to the gulf marine waters and immediate coast.
Temperatures will generally fall into the lower to middle 70's.

Heading into the day Monday, convective coverage will be slightly
less and more focused inland as better forcing shifts north and
northeast. A scattered to at times numerous coverage of showers
and thunderstorms is expected, particularly over inland areas of
southeastern MS and inland southwestern AL. A low end threat for
flash flooding will continue as storms will continue to be slow
moving, heavy rain producers. High temperatures will reach the
middle 80's for most locations. MM/25

&&

.SHORT TERM /Monday night Through Wednesday night/...A weakening
shortwave trof located just east of the lower/mid Mississippi
River valley Monday evening shifts slowly eastward then lifts off
to the north through Tuesday while an amplifying upper trof
advances across the Plains. A surface low associated with the
upper trof brings a cold front from the Plains to across the
lower/mid Mississippi River valley on Tuesday, which then moves
through the forecast area Tuesday night into Wednesday morning
while the upper trof continues into the eastern states. Ahead of
the approaching front, a rather weak surface trof develops over
the forecast area on Tuesday which will aid in convective
development, along with daytime heating and some modest support
from the passing shortwave trof. Have continued with mainly slight
chance pops Monday night for lingering convection, then good
chance to likely pops follow for Tuesday. As the front approaches
and then moves through the area, will have slight chance to chance
pops Tuesday night and Wednesday, with the higher pops west of
I-65 Tuesday night, then mainly along and east of I-65 on
Wednesday. Highs on Tuesday will be in the mid to upper 80s, then
highs on Wednesday will be cooler and range from 75 to 80 well
inland to the mid 80s near the coast. Lows Monday night range from
around 70 well inland to the lower/mid 70s at the coast then trend
much cooler by Wednesday night in the wake of the front when lows
range from the mid 50s well inland to the lower 60s at the coast.
A low risk of rip currents is expected through the period. /29

&&

.EXTENDED TERM /Thursday Through Sunday/...After an extensive
period with rainy/wet weather, dry conditions finally come to the
area for the extended term. A surface ridge builds into the region
in the wake of the cold frontal passage Tuesday night/Wednesday,
and a deep layer dry northerly flow prevails through the period.
Highs on Thursday range from the mid 70s well inland to around 80
at the coast then gradually moderate to highs in the lower to mid
80s by Sunday. Lows Thursday night range from the lower 50s well
inland to around 60 at the coast, then trend a bit warmer by
Saturday night when lows range from the upper 50s well inland to
the mid 60s at the coast. Thursday night looks to be the coolest
night so far since mid May by the way. /29

&&

.MARINE...A small craft advisory may be required Wednesday
afternoon through Thursday morning due to a strong offshore flow
that follows in the wake of a cold frontal passage. No other
impacts are sen other than seas and winds higher near storms. /29

&&

.MOB WATCHES/WARNINGS/ADVISORIES...
AL...None.
FL...None.
MS...None.
GM...None.
&&

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

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOBILE AL
410 PM CDT SUN SEP 19 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0845 AM     MARINE TSTM WIND 5 W JOHNSONS BEACH      30.29N 87.50W
09/15/2021  E40 MPH          ESCAMBIA           FL   MESONET

            MESONET BAYOU CT -> 35.5KT GUST.

&&

JEH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOBILE AL
413 PM CDT SUN SEP 19 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1155 PM     MARINE TSTM WIND 5 W JOHNSONS BEACH      30.29N 87.50W
09/15/2021  E40 MPH          ESCAMBIA           FL   MESONET

            MESONET BAYOU CT -> 34.8KT GUST.

&&

JEH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOBILE AL
414 PM CDT SUN SEP 19 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1215 AM     MARINE TSTM WIND 5 W JOHNSONS BEACH      30.29N 87.50W
09/15/2021  E40 MPH          ESCAMBIA           FL   MESONET

            MESONET BAYOU CT -> 35.1KT GUST.

&&

JEH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOBILE AL
417 PM CDT SUN SEP 19 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1130 AM     MARINE TSTM WIND 4 W JOHNSONS BEACH      30.30N 87.48W
09/15/2021  E39 MPH          ESCAMBIA           FL   MESONET

            MESONET TURTLE KEY -> 34KT GUST.

&&

JEH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOBILE AL
423 PM CDT SUN SEP 19 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0115 PM     MARINE TSTM WIND 4 W JOHNSONS BEACH      30.30N 87.48W
09/15/2021  E40 MPH          ESCAMBIA           FL   MESONET

            MESONET TURTLE KEY 34.8KT GUST.

&&

JEH

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE MOBILE AL
430 PM CDT SUN SEP 19 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1155 AM     MARINE TSTM WIND 5 W JOHNSONS BEACH      30.29N 87.50W
09/15/2021  E40 MPH          ESCAMBIA           FL   MESONET

            CORRECTS PREVIOUS MARINE TSTM WIND REPORT
            FROM 5 W JOHNSONS BEACH. MESONET BAYOU CT ->
            34.8KT GUST.

&&

JEH