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Area forecast discussion 
National Weather Service New Orleans la
841 am CDT Tuesday may 26 2015

..sounding discussion...
The sounding this morning represents an atmosphere that has been
worked over by storms just a couple hours prior. The profile is
nearly saturated throughout with precipitable water at 1.88 inches. Winds were
shown to be westerly behind the mesoscale convective system from the surface to 750 mb then
become southwesterly above except for a wind shift to the east
from 240 to 170 mb. The moist conditions remain and airmass
recovery could take place with daytime heating and a return to
southerly flow later today.



Previous discussion... /issued 354 am CDT Tuesday may 26 2015/ has been an interesting overnight period so far.
Things picked up quick as a Tornado Watch was issued for the area as
strong squalline was approaching and isolated to scattered convection
developed well ahead of it. One very interesting storm moved through
north.O. And possibly developed a tornado. The office did a 6z sndg
and this showed decent rotation in the ll with 0-1km srh of 189
m2/s2. This explains why these shallow storms have interesting looks
to the them.

Overall mainly focusing on the first 12 hours of the forecast with only
minor adjustments made to the extended portion. First the severe aspect
today or more so early this morning and then we will focus on flash
flooding potential. Abundant strong ll shear and decent instability
will continue to lead to a small threat of severe weather. Tornadoes
will be possible especially with any storm ahead of the line this
morning. This should be the shortest aspect of hazardous weather as
the squalline continues to be rather progressive and once it moves
through the severe threat will end. We have already begun dropping
parishes and counties out of the tornados watch.

As for heavy rain. There is still the potential for this line to
hang up somewhere over the region and if/where this occurs it could
lead to rather heavy rainfall later. Precipitable waters on the 6z sndg were at 1.9
and these storms have been rather efficient. Btr had almost 1.5
inches in about 45 mins. The airmass will not lose any moisture and
this could set the stage for later today/tonight. There should be a
break with mainly just light to moderate rain showers with embedded thunderstorms and rain
later this morning but as the next impulse(already moving into southern
Texas from mexico) pushes into the region num storms should redevelop
this afternoon. Again big concern will be where this line finally
lays up as it could act as a focus. Convection could be heaviest
late this afternoon and this evening and then finally push east and
north of the region overnight. We could initially be under the rrq
of the jet which could aid in efficiency of storms. Will not make
any adjustments to the current Flash Flood Watch at this moment but
will need to assess again later this morning.

Rain chances remain high through the week. Tomorrow we will remain
under SW flow aloft and this should allow for another impulse to
move across. As we move into Thursday we will move under short wave ridging but
hghts will actually not change and moisture will still be abundant
with precipitable waters above 1.75 and this should allow for convection to develop
after some decent heating. Heading into the end of the week and
weekend we will move under a weak trough aloft and scattered convection
should actually pop rather early Fri/Sat/sun. /Cab/

Marine...persistent onshore flow will continue to linger through
much of the work week but should start to weaken some by Thursday.
Onshore flow will become more easterly by this weekend as the
pressure field becomes less defined with a weak cold front dropping
into the lower MS River Valley and a surface low sitting over the Ohio
River valley. /Cab/


A potent line of showers and will sweep eastward
across the County Warning Area bringing IFR to all terminals during the 8z to 12z
timeframe with conditions improving to mostly VFR outside of
scattered thunderstorms. Southeast winds of around 10 to 15 knots
will persist throughout the daytime hours today. Broken to overcast ceilings
will persist throughout the day on Tuesday.

Decision support...
dss code...yellow
Activities...Tornado Watch
Flash Flood Watch

Decision support services (dss) code legend
green = no weather impacts that require action
blue = long fused watch/warning/advisory in effect or high
visibility event
yellow = heightened impacts with short fused
watch/warning/advisory issuances; radar support
Orange = high impacts - slight to moderate risk severe; nearby
tropical events; hazmat or other large episodes
red = full engagement for moderate risk severe and/or direct
tropical threats; events of National significance


Preliminary point temps/pops...
mcb 83 70 86 68 / 70 60 60 50
btr 85 72 87 70 / 70 60 60 50
asd 85 72 85 71 / 80 60 60 60
msy 86 73 86 73 / 70 50 60 50
gpt 84 74 84 73 / 100 60 60 50
pql 84 72 84 70 / 100 60 60 50


Lix watches/warnings/advisories...


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