Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus64 kmob 231722 aab 
afdmob

Area forecast discussion...updated
National Weather Service Mobile Alabama
1222 PM CDT Fri Jun 23 2017

Discussion...updated for latest aviation discussion below.

&&

Aviation...
18z issuance...expect scattered to numerous rain showers/few thunderstorms and rain to
develop over southeast MS and interior southwest Alabama thru
the afternoon with localized gusty winds and MVFR to IFR
cigs/vsbys with the stronger storms. South winds breezy at 15 to
20 knots with some gusts over 20 knots likely thru the afternoon,
before gradually diminishing to around 10 knots by this evening.
/10

&&

Previous discussion... /issued 1137 am CDT Fri Jun 23 2017/

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

Update...remnant circulation of Cindy over western Kentucky and western
Tennessee was shearing out to the northeast. South and west of the circulation,
a resurgence in cold cloud tops => showers/storms were developing
in a northeast to southwest band over central MS. Convection was
occurring within a zone of high deep layer tropical moisture where
total pwat was in excess of 2.00 inches. To the east, a well
defined deep layer ridge was positioned from the southwest
Atlantic into the eastern Gulf causing a net lowering in deep
layer moisture along and east of the I-65 corridor. Considering
the placement of the deep layer moisture and daily instability
with MUCAPE values increasing to around 3000 j/kg, the higher
precipitation chances remain advertised over the northwest zones.
Lower chances east of the Interstate. Due to soil moisture levels
being at capacity, there remains concerns that developing showers
and storms, repeatedly moving over the same areas, will likely
result in runoff and flooding. Flash flood watches continue from
Clarke co. Alabama to George co. MS and points west. Many area rivers
remain in minor to moderate flood.

Coastal hazards remain high. Despite a lowering in onshore flow,
long period swell and breakers of 5 to 8 feet look to linger into
the surf zone. This results in high surf, minor beach erosion, and
dangerous to potentially deadly rip currents today. /10

Marine...small craft advisories expired mid morning and will be
replaced with small craft exercise caution headlines. Seas
lowering. /10

Previous discussion... /issued 657 am CDT Fri Jun 23 2017/

Discussion...updated for latest aviation discussion below.

Aviation...
12z issuance...areas of MVFR to IFR cigs early this morning may
improve to VFR over portions of the forecast area later today, but
generally expecting MVFR to impact the coastal taf sites today.
Expect scattered to numerous rain showers and a few thunderstorms and rain to develop over
southeast MS and interior southwest Alabama later this morning and
especially into the afternoon with localized gusty winds and MVFR
to IFR conditions with the stronger storms. South winds increase
to around 15 knots with some gusts over 20 knots possible later
this morning into the afternoon before gradually diminishing to
around 10 knots by this evening. /21

Previous discussion... /issued 535 am CDT Fri Jun 23 2017/

Near term /now through Friday night/...area radars detecting the
far eastern outer rain band associated with the remnants of Cindy
just northwest of our forecast area. This band is expected to
shift back eastward throughout the day today, but remain northwest
of the I-65 corridor. By late this afternoon we expect scattered
to numerous rain showers along with embedded scattered
thunderstorms northwest of I-65, with some of the showers and
storms again capable of producing periods of heavy rainfall.
Scattered to numerous showers and a few thunderstorms will persist
overnight north of a line from Mobile to Andalusia, Alabama.

The heavy rainfall will mainly occur this afternoon and tonight
across our northwest zones, with additional rainfall amounts up to 3
inches possible, especially where the more persistent rain band set
up.

A moderate southerly wind flow will persist through today,
especially along the coastal sections. As a result, a coastal Flood
Warning is back in effect for southwest Alabama through 6 PM today,
and a coastal flood advisory will remain in effect for the western
Florida Panhandle. A high surf advisory and a high rip current risk
also remains in effect along the beaches of Alabama and the western
Florida Panhandle.

High temperatures today will range from 85 to 90 degrees. Low
temperatures tonight will be in the mid 70s inland areas, and upper
70s along the coast. /22

Short term /Saturday through Sunday night/...mid level zonal flow
will sink southward into the forecast area Saturday on the base of
a large scale trough spanning much of the north central states. An
associated cold front will also push southward toward far northern
portions of our forecast area through the day Saturday. Embedded
shortwave impulses within the moist zonal flow will allow for the
development of numerous showers and thunderstorms along the
frontal zone Saturday, and will maintain high pops over inland
portions of the cwa, with high end chance pops near the immediate
coast. Precipitable water values may become enhanced to between 2"
and 2.25" across the region Saturday, which may once again lead
to potential for locally heavy rainfall. Additional rainfall
amounts of 1 to 2 inches with locally higher amounts will be
possible with showers and storms during the day Saturday, and
given the saturated grounds from recent heavy rains, we will have
to closely monitor for localized flash flooding potential. A
chance of showers and thunderstorms will continue into Saturday
night along the southward moving frontal boundary, and will have
the higher pops focused over central and southern portions of the
region. Highs Saturday are forecast to range in the mid to upper
80s, with lows Saturday night in the lower 70s inland to the mid
to upper 70s near the immediate coast and beaches.

The front is forecast to remain near or just south of the
immediate coast Sunday, before gradually pushing southward over
the northern Gulf of Mexico Sunday night. The axis of deep layer
moisture shifts southward along the boundary, and will maintain a
chance of showers and thunderstorms across all areas during the
day Sunday, with convection becoming focused farther south near
the coast and offshore by Sunday night. Highs Sunday should mostly
range in the mid 80s, with lows Sunday night trending a little
cooler in the mid to upper 60s inland behind the front, with lower
to mid 70s near the immediate coast. /21

Long term /Monday through Thursday/...a drier northwest to zonal
flow will prevail across interior portions of the forecast area
Monday and Tuesday as our region remains on the base of a longwave
trough that will continue to extend across much of the eastern
Continental U.S.. an axis of deeper moisture may still remain in the vicinity
of coastal portions of the region per the latest ECMWF, so will
maintain a 20-30% chance of showers and storms, with the better
probabilities near the coast both Monday and Tuesday. Medium range
models are generally agreement with building an upper level ridge
across the eastern Seaboard and and adjacent western Atlantic
Wednesday and Thursday, allowing the axis of deeper moisture to
advect back northward over our County Warning Area late in the extended period.
This pattern should result in increased convective coverage over
the area mid to late next week. Early morning lows remain several
degrees below normal Monday through Wednesday mornings with the
drier airmass in place, with readings in the mid to upper 60s
inland, and in the lower to mid 70s near the coast. Highs each day
through the extended should generally range in the mid to upper
80s. /21

Marine...southerly winds and seas will continue to slowly diminish
through this evening as the remnants of Cindy track well inland over
the Mississippi and Tennessee River valleys. Rain chances will
increase over the weekend into early next week as a surface boundary
approaching from the north moves offshore. Tidal levels are also
expected to slowly recede through this evening. /22

&&

Mob watches/warnings/advisories...
Alabama...high rip current risk until 6 PM CDT this evening for alz265-266.

High surf advisory until 6 PM CDT this evening for alz265-266.

Flash Flood Watch until 10 PM CDT this evening for alz051>053.

Coastal Flood Warning until 6 PM CDT this evening for alz261>266.

Florida...high rip current risk until 6 PM CDT this evening for flz202-204-
206.

High surf advisory until 6 PM CDT this evening for flz202-204-
206.

Coastal flood advisory until 6 PM CDT this evening for flz202-
204-206.

MS...Flash Flood Watch until 10 PM CDT this evening for msz067-075-
076-078-079.

GM...none.
&&

National Weather Service Glossary of Abbreviations