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Area forecast discussion...updated 
National Weather Service Mobile Alabama
755 am CST Friday Dec 19 2014

Marine...updated current marine forecast mostly to reflect current
conditions across the marine area. Expect a moderate northeast to
easterly flow to continue over the marine area through Sunday. With
choppy conditions expected over most bays and sounds and seas building
to 3 to 4 feet well offshore will mention small craft should exercise
caution for most marine zones for today. 32/ee


Previous discussion... /issued 554 am CST Friday Dec 19 2014/

Update...a few isolated thunderstorms were occurring over coastal MS
this morning moving east. As a result have added slight chance for
thunderstorms in the current forecast for today. Widespread
thunderstorm development is still not likely. Any convection that
does occur will be elevated. 32/ee

Previous discussion... /issued 445 am CST Friday Dec 19 2014/

Short term (today through Sunday night)...for today and
tonight...a dampening short wave moving quickly eastward over
interior sections of the lower MS River Valley and central Gulf
states later today and tonight combined with a broad surface low
reflecting over the western Gulf will continue to give way to
widespread rain with embedded showers over much of the forecast area
later this morning continuing through tonight and early Sat morning.
As the surface low continues to approach from the west today increased
isentropic/layer lift over the adjacent Gulf waters of MS ... and
Alabama will shift east and north leading to better coverage of of precipitation
over coastal areas of the County warning forecast area early today then shifting further
inland this afternoon and tonight. As mentioned earlier with the low
center remaining mostly offshore through tonight the entire forecast
area still looks to remain on the cool side keeping daytime temperatures
below seasonal averages along with little to no thunderstorm activity
for both inland and offshore through early Sat morning. With the
cooler more stable air continuing near the surface any convection that
does occur will be elevated occurring mostly south of the immediate
coast. In the upper levels better divergence aloft is still noted
occurring mostly late this afternoon and this evening possibly
leading to some heavier rainfall totals over some interior sections
of the County warning forecast area later this afternoon and this evening. As mentioned above
will lean towards the cooler met guidance for highs today
undercutting these values by 1 to 3 degrees for all areas. The lowest
temperatures will be over the western half of the County warning forecast area today stretching
south to the immediate coast. Todays highs will be lower to middle
50s for most areas with the upper 50s only occurring over coastal
areas of the western Florida Panhandle generally east of the Pensacola Florida.
Tonights lows will in the lower to middle 40s for most inland areas
and the upper 40s to near 50 along the immediate coast. /32

For Saturday through Sunday night...a shortwave trough over the
interior southeast states exits to the east early Saturday followed
by an upper trough which advances into the plains through Sunday night
and amplifies to a longwave trough in the process. A surface low
located south of the Mississippi River Delta early Saturday morning
weakens with the departure of the interior southeast states upper
trough but leaves an inverted trough over the north central Gulf. A
shortwave ejected from the strengthening plains upper trough moves
across the region Sunday night and leads to a poorly defined surface
low reforming over the north central Gulf which moves off to the
east late Sunday night. Will have chance to good chance probability of precipitation
Saturday morning which taper to slight chance for Saturday afternoon
with the departure of the shortwave trough. As can be the case with
these southwest flow aloft patterns...have had to make a fairly
significant change to the forecast with much higher probability of precipitation for Sunday
and Sunday night as an ejected shortwave moves across the region
with the development of a poorly defined surface low passing south
of the area. Will have probability of precipitation increasing to likely over coastal
portions of the area on Sunday tapering to slight chance well inland
then for Sunday night will have likely probability of precipitation over the eastern portion
with chance to good chance probability of precipitation over the remaining area. The area
remains stable and have kept the mention of thunder out of the
forecast. Highs on Saturday will range from the upper 50s inland to
near 60 closer to the coast with slightly warmer temperatures on
Sunday over the coastal counties. Lows Saturday night will range
from the middle 40s inland to lower 50s closer to the coast...then
slightly warmer Sunday night. /29

Long term (monday through thursday)...the plains longwave trough
continues to deepen through Tuesday then takes on a negative tilt
while advancing into the eastern states through Wednesday. A
surface low deepens over the northern plains and moves off to the
Great Lakes region through Tuesday...likely occluding with the upper
trough in the process and bringing a cold front across the Gulf Coast
states which moves across the forecast area Tuesday afternoon into
Tuesday evening. A secondary surface low may develop on the
frontal boundary over Texas on Monday and advance eastward across
the Gulf Coast states with the advancing front. The best deep layer
lift looks to occur in advance of the front on Tuesday over the
forecast area...and in a region of 0-1 km helicity values of 100-150
m2/s2 and 0-3 km MUCAPES near 500 j/kg. This is somewhat more
favorable for strong storm development but for now will maintain
wording of some strong storms possible for Tuesday in the hazardous
weather outlook. Will have slight chance to chance probability of precipitation on Monday
increasing to good chance probability of precipitation across the area on Tuesday with
embedded thunderstorms developing. Chance probability of precipitation follow for Tuesday
night then dry conditions are in place for the remainder of the
period. /29

Marine...a weakening surface low will move continue to move east
across the northern Gulf today and Sat leading to a light to
moderate northeast to easterly flow over the marine area through
Sat...then building slightly Sat through Sunday afternoon. Winds and
seas will then diminish late sun into early next week as the surface
low to the south continues to shift east. A better southerly flow
develops Monday night into Tuesday ahead of another approaching cold front.
The cold front moves through the marine area on Tuesday leading to a
strong offshore flow late Tuesday through Wednesday. Widespread rain with
embedded showers will occur today and tonight tapering off somewhat
on Sat then redeveloping sun and Sun night. A better chance for
thunderstorms will also occur ahead and along the second cold front
Tuesday and Tuesday night. 32/ee

12z issuance...MVFR to IFR ceilings mostly in light to moderate rain
through 20.12z. Better rain chances can be expected this afternoon
and tonight tapering off slowly from west to east on Sat. Winds will
be mostly northeast at 7 to 10 knots through 19.12z. 32/ee


Preliminary point temps/pops...
Mobile 53 48 60 51 62 / 80 80 50 20 60
Pensacola 57 50 60 52 63 / 60 70 50 20 70
Destin 59 52 61 54 63 / 60 50 50 20 70
Evergreen 54 44 58 47 59 / 70 80 50 20 30
Waynesboro 51 42 58 46 58 / 90 80 40 10 20
Camden 55 43 58 45 56 / 80 90 50 10 20
Crestview 58 46 61 49 62 / 60 60 50 20 70


Mob watches/warnings/advisories...


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