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fxus64 kmob 240448 aac 

Area forecast discussion...updated
National Weather Service Mobile Alabama
1148 PM CDT Sat Sep 23 2017

Discussion...updated for latest aviation discussion below.


06z issuance...general VFR cigs/visbys expected through the
overnight hours. Local drops in visbys to MVFR levels possible
with fog development, but am expecting this to be isolated.
Another round of rain showers/thunderstorms and rain are expected to form Sunday afternoon
bringing drops to MVFR levels, along with locally strong winds.
Best coverage is expected to be along and west of the Tombigbee



Previous discussion... /issued 906 PM CDT Sat Sep 23 2017/

Discussion...see updated information for land areas below.

Update...another round of isolated to scattered strong storms
developed across the region today, producing localized
occurrences of strong gusty winds, frequent lightning, heavy rain
and small hail. Convection has since dissipated with loss of
daytime heating. Pops have been removed for the late evening
hours, but left a slight chance of showers and storms near the
coast during the 06-12z time frame, where isolated convection
could re-develop as an upper level low moves westward overnight.
We also made some minor adjustments to hourly temperatures. /21

Previous discussion... /issued 626 PM CDT Sat Sep 23 2017/

Discussion...updated for latest aviation discussion below.

00z issuance...isolated shra/tsra continue to move east over the
area, with greatest coverage and strength being west of the Alabama/Florida
state line. Am expecting coverage and intensity to decrease
through the evening, with minimal to no activity by 03z. Localized
patchy overnight fog development possible after midnight, but do
not feel coverage/intensity will impact any Airport operations
across the area. Another round of shra/tsra is possible Sunday
afternoon as an upper system moves west along the northern Gulf
Coast, but at this point, best coverage is expected to be along
and west of the Tombigbee/Mobile rivers.


Previous discussion... /issued 353 PM CDT Sat Sep 23 2017/

Near term /now through Sunday/...thunderstorms are ongoing roughly
along and west of the Interstate 65 corridor this afternoon, and
will continue to drift southwest before dissipating after sunset
late this evening. Stronger cells will remain capable of producing
gusty winds, small hail, and frequent lightning.

Tonight into Sunday, the upper low currently positioned over the
Florida Panhandle continues to move west, ultimately settling over
the lower Mississippi River valley by Sunday evening. With this
shift, a plume of deeper moisture (pwats around 1.8 to 2.0 inches)
moves into the local area from the south. Aided by dynamic support
from the upper low, showers and thunderstorms should become more
numerous on Sunday than they've been the past few days, with
activity starting offshore late tonight and gradually spreading
inland throughout the day Sunday. Some very patchy fog will remain
possible as well late tonight, ahead of any showers moving onshore
around daybreak. While the more saturated mid levels will limit
downburst potential, the lightning and locally heavy rainfall
threats will continue through the near term, particularly in any
stronger storms that form Sunday afternoon and evening.

Low temperatures tonight range from upper 60's inland to mid 70's
along the immediate coast. Highs on Sunday remain a bit cooler than
recent days given the greater coverage in clouds and rain, with mid
80's expected near the coast and upper 80's well inland. /49

Short term /Sunday night through Tuesday night/ upper low
over the area will slowly drift west and weaken. As the low moves
west of the area on Monday, the Gulf Coast will be on eastern
side of the low. This along with better deep layer moisture will
allow for the development of scattered to locally numerous showers
and thunderstorms on Monday, becoming most numerous during the
afternoon hours. As the upper low moves west and weakens on
Tuesday, a drier airmass will move in from the north and east on
the western fringes of the circulation around Hurricane Maria off
the East Coast. Highs on Monday will be slightly cooler due to
additional clouds and rain, before returning to near normal on
Tuesday. Lows remain in the upper 60s inland to low 70s along the

Long term /Wednesday through Saturday/...upper ridging will build
over the area Wednesday into Thursday, maintaining dry and warm
conditions. Late in the week an upper trough is expected to dig
over the eastern states. This will send a cold front southward
into the area late in the work week, with a cooler and drier
airmass moving in for the weekend. /13

Marine...a surface ridge of high pressure remains in place over the
eastern Continental U.S. And northern Gulf through most of the forecast period,
with light to occasionally moderate easterly flow continuing into
early next week over our marine area. Still expecting some diurnal
influence near the coast, with winds being more northeasterly during
late night and early morning hours and southeasterly during
afternoon and evening hours. Conditions could reach exercise caution
levels Sunday, around 15 knots with gusts to around 20 knots, along
with seas building to around 3 to 4 feet. On top of this, could see
locally higher winds and seas in and around scattered showers and
thunderstorms Sunday and Monday. Winds and seas relax through the
early part of next week as Hurricane Maria moves north into the
western mid-Atlantic and the pressure gradient relaxes over our
area. A weak frontal passage is then expected around midweek, with
light offshore flow developing in its wake. /49


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