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Area forecast discussion 
National Weather Service New Orleans la
840 am CDT sun may 24 2015

Sounding discussion...

Morning sounding indicating precipitable water at 1.40in with moist layers at the
surface to 6kt and from 20 to 30kt. Wind profile shows deep southerly
flow from the surface to 45kt. Convective temperature of 81 already
exceeded at 8am so cumulus field developing rapidly. Not much in the
way of any inhibiting factors in the sounding when it comes to
lifting a parcel with a cape of 723j/kg and Li around minus 5.
Surface to 1km shear calculation was 31kt with a brn shear at 11m2/s2.
Plenty of support for thunderstorms today however widespread severe
weather not expected. Plenty of support for very heavy rain
associated with thunderstorms...frequent lightning and gusty
outflow winds. Balloon burst at 111995ft above burgetown Road just
west of Highway 11 in Carriere MS. /Keg/


Previous discussion... /issued 441 am CDT sun may 24 2015/


Surface map revealed a deep 1005mb low over northeast New Mexico. Southeast
flow was present from Texas to Missouri and over middle and lower
Mississippi Valley. Dewpoint readings of 70 degrees was from the
Gulf Coast to the arklatex region. 00z precipitable water values
showed moisture axis from Texas and Louisiana coast to eastern
Oklahoma 1.75 to 2 inches. Upper air charts showed a cyclonic
circulation just north of The Four Corners region and anti-
cyclonic circulation over North Florida. Associated ridge axis
extended north to the Great Lakes region. Southwest flow was
present from Texas to middle Mississippi Valley with an embedded
short wave over south Texas. 18


Short wave over south Texas will track northeast today bringing
a squall line across west half of forecast area this afternoon.
The main trough will move to the plains late tonight. Moisture
axis of 1.75 inches will likely shift east from Arkansas/Louisiana
and northwest Gulf. Middle layer instability is expected along with
the moisture axis. Surface heating will create ll instability.
Ergo...looking for convection to track across Louisiana and
southern Mississippi this afternoon and tonight. Ergo...will carry
elevated rain chances this afternoon and overnight. Moisture axis
will remain in play Monday so will keep likely probability of precipitation for Monday.
Another wave embedded in the southwest flow is expected to track
across northwest Louisiana and bring a marginal threat of strong
storms across the west half of forecast area on Tuesday. Trough
will lift as another deepens over the West Coast and rockies
Wednesday through Friday. Some model differences for next weekend
as GFS show some relatively dry air tracking to the area from
Florida and Euro shows another short wave approaching the next
Sunday. Will show a slight increase in rain chances latter part of
next weekend. 18


Most terminals are in VFR with a few observing MVFR due to either
few/scattered lower cloud decks or light fog. Could see slightly more fog
as sunrise approaches. Radar shows a few showers SW of khum at this
time but the bulk of convection will begin developing late morning
and into the afternoon hours. Models also indicate a line of
moderate to heavy rain with thunderstorms will move in from the west
late afternoon. IFR to LIFR conditions possible then with low visible
from heavy rain.



Surface ridge that was draped across the Appalachian
Mountains and into the Gulf of Mexico is shifting east into the
Atlantic. It will remain fairly close to the coast through midweek.
Surface trough generally remaining west of the area over western
Texas will keep the local pressure gradient fairly tight. The result
of these surface features will be southeast winds in the 15 to 20
knot range. So expect to see exercise caution headlines for much of
the week. Upper level ridge will try to build in over the western
half of the Gulf of Mexico late this week and into the weekend. This
will weaken the gradient over the coastal waters and cause
winds/seas to relax a bit.


Decision support...

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 86 71 84 71 / 50 60 70 50
btr 87 72 84 72 / 60 60 70 50
asd 87 72 83 73 / 30 60 70 40
msy 87 75 85 75 / 50 60 70 50
gpt 85 74 82 75 / 30 60 70 40
pql 85 72 83 73 / 30 50 70 40


Lix watches/warnings/advisories...


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