314
FXUS64 KMOB 120214
AFDMOB

Area Forecast Discussion
National Weather Service Mobile AL
914 PM CDT Sat May 11 2024

...New UPDATE...

.UPDATE...

Issued at 913 PM CDT Sat May 11 2024

Forecast guidance has trended toward showing a band of mainly
light precip developing and impacting the southern half of the
forecast area overnight tonight into early Sunday morning. This is
due to increasing moisture and mid level frontogenesis ahead of a
shortwave over east TX (where you can see numerous thunderstorms
developing). In addition, there will be modest upper level
divergence across the area due to a NW-SE oriented upper jet
streak from the TN Valley to off the southeast Atlantic coast.
Forecast soundings show this precip falling from mainly a mid
level deck of clouds, so expect overall totals to be fairly light.
Forecast has been updated to include a chance of rain for after
midnight through Sunday morning to account for this.

For northern lights watchers, clouds will quickly increase late
tonight from west to east. This means our viewing window will be
quickly closing over the next few hours. 34/JFB

&&

.PREV DISCUSSION... /issued 639 PM CDT Sat May 11 2024/

..New AVIATION...

AVIATION...
(00Z TAFS)
Issued at 636 PM CDT Sat May 11 2024

VFR conditions are expected through the TAF period. Mid and high
level clouds will increase by Sunday morning and some very light
and patch rain cannot be ruled out. A generally light northeast
wind tonight becomes southeast by Sunday afternoon, increasing to
around 10 kt near the coast and across SE MS. 34/JFB

PREV DISCUSSION... /issued 429 PM CDT Sat May 11 2024/

.New NEAR TERM, SHORT TERM, LONG TERM, MARINE...

NEAR TERM...
(Now through Sunday)
Issued at 424 PM CDT Sat May 11 2024

Slight ridging aloft is expected tonight through Sunday, as surface
high pressure also generally persists over the region. A weak front
will drop south across the forecast area late tonight into early
Sunday, reinforcing the slightly cooler and much drier airmass that
is currently in place (at least through Sunday morning). We will
likely be seeing an increase in mid and high levels clouds in the
near term period, however. The initial front that moved through on
Friday that is now stationary well to our south out over the Gulf of
Mexico will slowly begin to lift back north as a warm front by late
Sunday. This could bring some late afternoon showers to the southern
(mainly coastal) sections of our forecast area by late Sunday
afternoon, but rain chances will be very low (less than 20 percent).
Temperatures will be around or just below normal for this time of
the year. Lows tonight should range from the upper 50s up along the
Highway 84 corridor to the low or mid 60s south toward and along the
coast. Highs on Sunday will generally be in the lower 80s across the
entire area. Along with the slightly lower temperatures we will also
be looking at dewpoints in the 50s through the near term, so
humidity levels will feel somewhat tolerable for this time of the
year, both tonight and Sunday. DS/12

SHORT TERM...
(Sunday night through Tuesday night)
Issued at 424 PM CDT Sat May 11 2024

Through the Short Term, a closed upper low over the Plains pushes
east against an upper ridge over the eastern Conus, with both moving
to either side of the East Coast by Wednesday morning. Two rounds of
shortwave energy move over the Southeast with the upper low. The
first round passes Sunday night into Monday. A surface low develops
over southern Tx with the first round of shortwave energy, then
heads northeast over the Plains under the influence of the upper
low. A surface warm front moves inland with the surface low, and
with that, good surface based instability. Guidance has been
inconsistent with the placement of the instability, but has shown a
westward shift the last several days. With this issuance, the best
instability moves inland over the Southern Plains and Lower
Mississippi River Valley. A second round crosses the Southeast
Monday night into Tuesday, with a trailing cold front moving across
the forecast area Tuesday, ushering in mainly a drier airmass for
mid week.

For the KMOB piece of the Conus, guidance varies mainly with the
magnitude of the ingredients, but also somewhat with placement.
Have went with a blended approach as a result. Guidance is
advertising average SBCapes between 2500 and 3000 J/kg along and
south of the warm front, mainly over areas west of a Waynesboro to
Pensacola line. Add in EBWD wind shear values around 50kts, and
strong to severe storms are possible. 0-1km helicities between 100
and 200 m^2/s^2 are advertised, with supercells becoming possible,
mainly west over our Mississippi zones. In the upper support
department, guidance varies on placement and strength. Most are
advertising a modest 850mb jet of 30-40kts Monday afternoon, along
with modest upper divergence Monday through Monday night.
Guidance is consistent in less coincidence of the the upper
ingredients with the lower levels. SPC has at this time placed
areas west of the Alabama/Mississippi state line in Slight Risk of
severe weather for Monday/Monday night, and can not disagree at
this time. There is also a possiblity of water issues, especially
with possible training cells. Helping to temper the water issues
is the growing season in effect, and the ground able to handle
more water.

Looking at temperatures, temperatures rise to around seasonal norms.
High temperatures in the upper 70s to low 80s Monday rise into the
low to mid 80s for Tuesday. Low temperatures in the low to mid 60s
Sunday night (upper 60s along the coast) rise into the mid 60s to
around 70 for Monday and Tuesday nights.

With a more organized onshore flow the beginning of the coming
week, The Rip Risk is expected to rise to High by Tuesday and
remain there through most of the rest of the week.
/16

LONG TERM...
(Wednesday through Saturday)
Issued at 424 PM CDT Sat May 11 2024

Another shortwave trough approaches the Southeast Friday. Onshore
flow returns late Wednesday, bringing Gulf moisture back inland and
a return of showers and thunderstorms mainly for Thursday and
Friday. Temperatures around to a bit above seasonal norms are
expected, with high temperatures in the mid to upper 80s. Low
temperatures Wednesday night are expected to range from around 60
well inland to upper 60s close to the coast, with mid 60s along and
north of Highway 84 to low 70s along the coast expected for Thursday
and Friday nights.
/16

MARINE...
Issued at 424 PM CDT Sat May 11 2024

A light to moderate offshore flow will continue through tonight.
A light to moderate onshore flow returns to the marine area on
Sunday and persists into the early part of the coming week as a
system approaches the area from the west. Increasing onshore flow
and building seas are expected during the mid to late part of next
week, and hazardous conditions for small craft may be possible by
mid to late week, especially over the offshore Gulf marine zones.
Showers and thunderstorms will impact the marine area at time
over the next week as well, primarily Monday night into Tuesday
and again during the Thursday-Friday timeframe, and locally higher
winds and seas near those storms could also pose a threat to
small craft at times next week. DS/12

&&

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

$$

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