Area Forecast Discussion
Issued by NWS Mobile, AL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS64 KMOB 230531 AAB

Area Forecast Discussion...UPDATED
National Weather Service Mobile AL
1231 AM CDT Thu Mar 23 2017

.DISCUSSION...Updated for latest aviation discussion below.


06Z issuance...VFR conditions overnight will become MVFR during
the day on Thursday. Light northerly winds tonight shift
to southeasterly and increase to around 10 to 15 knots Thursday
morning and afternoon. /13


.PREV DISCUSSION... /issued 632 PM CDT Wed Mar 22 2017/

DISCUSSION...Updated for latest aviation discussion below.

00Z issuance...Only few to scattered high clouds and VFR
conditions expected overnight before increased cloud cover with
VFR to potentially MVFR ceilings overspreads the area from the
east, generally after sunrise. Light northerly winds tonight shift
to southeasterly and increase to around 10 to 15 knots Thursday
morning and afternoon. /49

PREV DISCUSSION... /issued 425 PM CDT Wed Mar 22 2017/

NEAR TERM /Now Through Thursday/...With an upper trough over
the northeast swinging away to the east and another moving onshore
over the Southwest, an upper ridge over the Plains gets moved east
to over the Mississippi River by Thursday evening. Surface high
pressure centered over the Great Lakes gets pushed southeast, to
off the DelMarVa/Carolina coast by Thursday evening. With increasing
subsidence from the approaching upper ridge, temps above seasonal
expected to continue, but Thursday not quite as warm as today.
The problems lies in a weak front getting pushed over eastern
portions of the forecast area today into tonight, stalling, then
beginning to wash out Thursday. For tonight, the northerly flow
brings in a bit cooler air and overnight lows ranging from low 50s
north to around 60 along the immediate coast. Tomorrow sees the
greatest affect from lingering clouds over eastern portions of the
forecast no rain is expected, but the increase cloudiness into
Thursday will help to limit daytime heating, leaving an west-east
gradient across the forecast area for high temps, even with the
approaching upper ridge. Highs ranging from mid 70s east to low
80s west. 16/SAM

SHORT TERM /Thursday night Through Saturday night/...Ridging
surface and aloft continues over forecast area Thursday night
through Friday. With the surface high centered off to our north
and east, a low level southeasterly flow will be bringing
increased moisture into the area through the period. Upper ridge
axis moves east of the forecast area by Friday afternoon, with mid
level flow also becoming southeast to south by late Friday and the
early part of the weekend. A well defined mid/upper low pressure
area develops over the plains states by Friday afternoon and moves
slowly east-northeast toward the Great Lakes region by the end of
the period, with associated upper trof becoming slightly
negatively tilted as it moves east across our area Saturday
afternoon and evening. Model data shows some 500mb shortwave
energy moving across our area late Saturday afternoon and evening,
and will likely have a line of showers or storms moving east
across the region during that timeframe, and we have maintained
the good chance to likely PoPs for Saturday. The 12Z operational
GFS and ECMWF still remain in general agreement that we will have
sufficient instability (800-900 J/KG MLCAPE) with shear (25-35
knots of 850 mb flow and 100-200 m2/s2 storm relative helicity,
0-3km). Potential for some strong to marginally severe storms
over the forecast area Saturday, but still rather minimal looking
for our area at this time. SPC Day 4 outlook at 15% severe
potential for our CWA on Saturday, and we believe if that
potential will be there it will likely be over our western and
northern counties on Saturday afternoon. We will continue to
monitor and mention the possibility of a few strong to severe
storms in the Hazardous Weather Outlook. With cloud cover,
increasing precipitation chances and higher dewpoints, look for
temps to moderate somewhat though still remain slightly above
normal. Highs in the 70s each day, lows generally around 60 each
night. 12/DS

LONG TERM /Sunday Through Wednesday/...Brief high pressure
rebuilds over the region Sunday and Monday, but another fast
moving frontal system likely to move east across the area Monday
night and Tuesday. Somewhat unsettled pattern through the long
term period with isolated to scattered mainly afternoon showers
and possibly a few thunderstorms. Warmer again especially in the
daytime, with highs in the upper 70s and lower 80s. Nighttime
lows in the upper 50s and lower 60s. 12/DS

MARINE...A weak front will move south to near the coast tonight
and stall, bringing northeasterly flow. As a surface high moves
from the Great Lakes to off the East Coast, flow over local coastal
waters shifts to southeast and with a tightening gradient becomes
moderate to strong. A Small Craft Advisory will be in effect for
much of the marine area from 4pm Thursday to 1am Saturday. The
onshore flow remains a moderate to strong through late weekend
and into the coming week. 16/SAM


GM...Small Craft Advisory from 4 PM this afternoon to 1 AM CDT
     Saturday for GMZ631-632-650-655-670-675.



This product is also available on the web at: is the U.S. government's official web portal to all federal, state and local government web resources and services.