Area Forecast Discussion
Issued by NWS Mobile, AL

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FXUS64 KMOB 200322

Area Forecast Discussion
National Weather Service Mobile AL
1022 PM CDT Mon Mar 19 2018

.DISCUSSION...See updated information below.


.UPDATE...Have updated and sent package to slow down
cooling/drying as front approaches the area. Front as of this
writing is moving over the Mississippi Delta and expected to
reach northwestern portions of the forecast area around 06z/1am
and past most of the forecast area by 12z/7am. Have added fog over
coastal zones east of Mobile bay, with hires guidance advertising
some fog moving inland ahead of the front and its drier air.
Also, have pared back on the thunder mention, and rain in general.
At this point, upstream radars are dry. Didn`t remove shra
entirely over eastern portions of the area, though, with this area
the last to clear out. Package has been transmitted.


.PREV DISCUSSION... /issued 631 PM CDT Mon Mar 19 2018/

DISCUSSION...Updated for latest aviation discussion below.

00Z issuance...Skies have cleared out nicely for KMOB and KBFM
this evening. Low stratus has held on at KPNS but should begin to
break shortly. Chance for IFR and LIFR ceilings into the late
evening for KBFM and especially KPNS before the cold front swings
through overnight and winds become westerly and northwesterly.
Winds will become gusty out of the northwest tomorrow morning and
into the afternoon hours. 05/RR

PREV DISCUSSION... /issued 401 PM CDT Mon Mar 19 2018/

NEAR TERM /Now Through Tuesday/...Main concern for the next 24
hours will be the threat for a few isolated strong to possibly
severe thunderstorms this afternoon and this evening ahead and
along an approaching cold front from the northwest, followed by
strong gusty northwesterly winds in the wake of the cold front
beginning early Tue morning, continuing through Tue afternoon. For
the threat of severe weather surface based instability has
climbed with mixed layered capes generally from 1500 to 3000 j/kg
combined with better mid level forcing approaching from the west
ahead of the cold front, along with surface dewpts ranging from
the upper 60s to lower 70s. With this pattern a few strong
thunderstorms still can`t be ruled out especially late this
afternoon through early this evening. The main limiting factor
continues to be a strong cap around 6kft mostly from warm air
advection generally from the southwest. Gusty straight line winds
and hail will continue to be the main threat with the tornado
threat continuing to cease as surface to 3k winds continue to veer
to the southwest and west. For late tonight into Tue a strong
pres gradient begins to set up between a departing surface low
well to the northeast and a strong surface ridge approaching from
the northwest and north. As a result frequent wind gusts from 25
to 35 knots will be possible by early Tue, continuing through
early Tue evening. As a result we will monitor this situation
closely for possible wind advisories early Tue through Tue

Temps will continue to be 3 to 7 degrees above seasonal norms
tonight, ranging from lower 50s behind the front and the lower 60s
to the east ahead of the front. Highs Tue will be 3 to 6 degrees
below seasonal norms ranging from the lower 60s well to the
northwest and the upper 60s to near 70 to the southeast.

SHORT TERM /Tuesday night Through Thursday night/...A highly
amplified pattern develops aloft, with longwave troughing over
the eastern seaboard and ridging building over the Great Plains to
our west. Between these features, and over the local area, a dry
northwest deep-layer flow sets up, keeping our skies mostly clear
and weather dry through the short term. Temperatures will be cool,
with daytime highs in the mid to upper 60s and nighttime lows in
the upper 30s and low 40s. /49

LONG TERM /Friday Through Monday/...Heading into the long term,
high pressure at the surface pushes to the east of our area,
shifting local winds from northerly back to southerly. This
onshore flow continues into the weekend, transporting Gulf warmth
and moisture back into the area Saturday. During this time, weak
and broad upper-level ridging pushes over the eastern CONUS, with
subsidence beneath this ridge helping to keep the otherwise
warming and moistening boundary layer rain-free. This upper ridge
pushes off to the east Sunday, with the departing subsidence
allowing for slight rain chances to creep back into our area.
Better chances for showers and thunderstorms then look to return
Monday into early next week as a weak southern stream shortwave
ejects over the Great Plains and a surface low develops to our
west. /49

MARINE...A moderate to strong southwest to westerly flow will
continue tonight ahead of a cold front approaching from the
northwest. Areas of fog, likely dense at times, will continue
through midnight then begin to lift as winds shift more to the west
late tonight and early Tue morning. Showers and thunderstorms are
expected ahead and along the front with a few strong storms still
possible through this evening. A strong northwest flow is expected
in the wake of the front on Tue and will continue through Wed late
morning, then gradually diminish through Thu. Frequent gusts to gale
force will also be likely in the wake of the front, occurring mostly
over the open gulf waters out to 60 nm from Tue afternoon through
Tuesday night. Seas from 9 to 11 feet will be likely late Tue into
Tue night. 32/ee


AL...High Rip Current Risk through Wednesday morning for ALZ265-266.

FL...High Rip Current Risk through Wednesday morning for FLZ202-204-

GM...Dense Fog Advisory until 1 AM CDT Tuesday for GMZ630>636-650-655.

     Small Craft Advisory from 7 AM Tuesday to 7 PM CDT Wednesday for

     Small Craft Advisory from 7 AM to 1 PM CDT Tuesday for GMZ650-

     Small Craft Advisory from 5 AM to 7 PM CDT Wednesday for GMZ650-

     Gale Warning from 1 PM Tuesday to 5 AM CDT Wednesday for GMZ650-



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