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fxus64 kmob 220010 aaa 

Area forecast discussion...updated
National Weather Service Mobile Alabama
610 PM CST sun Jan 21 2018

Discussion...updated for latest aviation discussion below.


00z issuance...VFR conditions through about 22.04z followed by
IFR to LIFR cigs and visibilities through 22.15z then improving
to mostly MVFR cigs and visibilities through 23.00z. Lower cigs
and visibilities mainly in fog and low stratus tonight and early
Mon followed by low clouds along with showers and thunderstorms
late Mon morning through Mon afternoon. Winds will be mostly
southeast at 6 to 12 knots through the forecast period with
higher gusts mostly in and around showers and thunderstorms
during the day on Mon. 32/ee


Previous discussion... /issued 357 PM CST sun Jan 21 2018/

Near term /now through Monday/ upper level low pressure
area deepening over northern Kansas will lift slowly northeast
over southern Iowa through the near term. Meanwhile, a surface
high pressure ridge across the southeast states and northeast Gulf
of Mexico will shift eastward and weaken in response to a surface
low pressure area forming across northern Oklahoma. This surface
low pressure area will also deepening as it lifts slowly
northeast, reaching eastern Iowa by late Monday afternoon. A light
southerly to southeasterly wind flow will persist across the
forecast area between these two features through Monday afternoon
as a cold front approaches from the west.

A strengthening upper level jet Max south of the upper low will
reach a maximum speed of 130 knots north of the forecast area by
late Monday afternoon. A strengthening low level jet is expected to
develop over the forecast area after midnight, ranging from 30 to 40
knots. Mixed layer cape values Monday afternoon ahead of the front
are forecast to range from 300 to 600 j/kg, with upper level lapse
rates reaching near 6.8 c/km. With a drier air mass remaining in the
mid levels along with the above mentioned parameters, still expect a
few strong thunderstorms during the day Monday after 9 am. Strong
thunderstorm wind gusts between 35 to 45 mph and small hail are
possible with the strongest storms mid afternoon.

Patchy fog will develop tonight into Monday morning across the
southern and western portions of the forecast area as low level
moisture moves in from the Gulf. Total rainfall amounts between two-
tenth to three-tenths of an inch is expected on Monday, with higher
amounts near one inch possible in areas affected by a strong
thunderstorm. /22

Short term /Monday night through Wednesday night/...showers and
isolated thunderstorms will move east of the area Monday evening
as a cold front moves through the area. A cooler and drier airmass
moves into the area in the wake of the front through Wednesday.
However, no extreme cold is expected as the upper flow becomes
semi-zonal in the wake of this upper trough. Temps will actually
be very near seasonal norms. /13

Long term /Thursday through Sunday/...upper ridging will build
late in the work week in advance of the next developing trough
over the western states. This will allow temps to warm back above
normal levels. Conditions remain dry through early Friday before
chances for rain increase Friday afternoon as moisture levels
begin increasing ahead of an approaching cold front. The highest
rain chances are expected during the day on Saturday into Saturday
night as the front moves through. /13

Marine...moderate southeast winds will become south to southwest on
Monday in response to the cold front approaching from the west.
Patchy fog will develop tonight into Monday morning across the bays,
sounds and near shore Gulf waters, followed by showers and a few
thunderstorms developing throughout the day Monday. The front is
expected to move east across the marine area Monday night, followed
by a moderate to strong offshore flow Tuesday through Thursday.


Mob watches/warnings/advisories...

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