Area forecast discussion...updated
National Weather Service Mobile Alabama
1159 PM CDT Wednesday may 22 2013
Aviation (06z issuance)...VFR conditions and light winds begin the
taf period then have continued with MVFR conditions in light fog
beginning at 09z. Although current dewpoints are running slightly
lower than 24 hours ago...WRF cores and rap hrrr/NAM visibilities
support a tempo group from 09-13z for LIFR/IFR conditions. VFR
condition return by 14z and continue for the remainder of the taf
period. /29
&&
Previous discussion... /issued 325 PM CDT Wednesday may 22 2013/
Short term [tonight through Thursday night]...weakening frontal
boundary lingers across the region through tonight. A series of weak
upper level disturbances will round the base of broad upper trough
moving off to the east...but dynamics are very weak with these
features and only isolated convection expected through Thursday...but
some scattered convection along the southern zones this evening where
lingering outflow boundaries from previous convection are present.
Much drier deep layer air expected Thursday as middle/upper flow becomes
northwesterly. Quantitative precipitation forecast values generally one quarter inch or less this
evening. Overnight min temperatures expected to be near climatology or a little
above climatology...lower/mid 60s inland and upper 60s lower 70s coastal.
Daytime highs Thursday above climatology most locations...upper 80s and
lower 90s. 12/ds
Axis of middle level trough to advance east across the Appalachians
Thursday night while a weakening cold front sinks southward across
the central Gulf Coast. Out of respect for hard to resolve middle level
impulses in the evolving northwest flow aloft...any surface focus
from frontal boundary and precipitable waters from 1.3 to 1.5
inches...could see a few nocturnal showers and storms coming
southeastward out of southeast Mississippi to across southern
Alabama...generally south of Highway 84. Given the weakened or
weakening state of front...layer lift also looks weak so will keep
chances of storms mostly 10%. Little change expected in nighttime
lows. /10
Long term [friday through wednesday]...a much drier northwest flow
pattern aloft will develop across the region Friday on the eastern
fringe of an upper level ridge of high pressure that will build from
the western Gulf of Mexico to the arklatex region and northward into
the upper midwestern states. Surface high pressure will meanwhile
continue to build from the Tennessee Valley southward to the Gulf
Coast region. Northerly surface flow and near normal temperatures are
expected Friday. The surface ridge should continue to build
southward Friday night...and looks to bring a drier airmass southward
into the forecast area along with it. Mostly clear skies and lower
dewpoints should result in cooler overnight lows across the region.
Will maintain lows into the 50s generally north of the immediate
coast for Saturday morning.
Dry weather should persist across the central Gulf Coast through the
weekend as a west to northwest flow pattern aloft continues. Little
change in daytime temperatures are anticipated Saturday and Sunday...
with most locations expected to range in the middle to upper 80s both
days. No changes were made to the remainder of the extended forecast.
Upper level ridging looks to expand at least across much of the Gulf
of Mexico through early next week...so no rain is in the forecast
through Wednesday. Temperature forecast unchanged with daily highs
well into the 80s and lows moderating well into the 60s by Tuesday
and Wednesday morning. Closer to 70 along the beaches. 10/21
Marine...surface high pressure will continue over the eastern Gulf and
western Atlantic through Thursday night then weaken slightly Friday
into the early part of the weekend in response to a weak cold front
approaching from the north and moving into the marine area while
dissipating. A light to moderate onshore flow is expected to continue
through late Thursday...with highest winds and largest seas during
the afternoon and evening hours due to a developing seabreeze each
afternoon. A moderate to strong offshore flow will develop into the
early part of the weekend...becoming more easterly late in the
weekend and then southeasterly by early next week as high pressure
shifts off the southeast Atlantic coast. 12/ds
Fire weather...deep mixed layers the next couple days result in high
dispersion indices => numerical ratings at or above 75 for many areas
Thursday and Friday. /10
&&
Preliminary point temps/pops...
Mobile 67 90 66 88 57 / 20 00 10 05 00
Pensacola 70 88 70 88 61 / 20 00 10 05 00
Destin 72 81 71 86 64 / 20 00 05 05 00
Evergreen 64 93 63 86 53 / 20 05 10 05 00
Waynesboro 64 93 62 85 52 / 10 05 10 05 00
Camden 64 92 62 83 52 / 20 05 10 05 00
Crestview 63 94 64 89 53 / 20 00 05 05 00
&&
Mob watches/warnings/advisories...
Alabama...none.
Florida...none.
MS...none.
GM...none.
&&
$$
