723
acus01 kwns 050540
swody1
Storm Prediction Center ac 050538
Day 1 convective outlook
National Weather Service Storm Prediction Center Norman OK
1138 PM CST Sat Feb 04 2012
Valid 051200z - 061200z
..no severe thunderstorm areas forecast...
...
in the middle and upper levels...a closed cyclone is forecast to remain
nearly stationary over the central Great Basin and central rockies.
Meanwhile...a closed low will move eastward from MO toward the central
Appalachians within the southern fringes of broad cyclonic flow covering
the northestern states. A low-amplitude...moderate flow regime will be
found south of these features over the southern states...while a surface
front moves across parts of the southeastern Continental U.S..
..sern states...
Reduction in the areal coverage of the warm sector will continue as
a cold front moves eastward across parts of al/GA/FL...and a segment of
the front moves southward over portions of the Carolinas. Surface dewpoints in
the upper 50s to the lower 60s and diurnal heating should promote
predominantly weak destabilization throughout the warm sector.
And...with sufficient frontal convergence...isolated to widely
scattered thunderstorms are anticipated. As surface winds veer across
portions of North Florida toward central/eastern SC...unidirectional westerly wind
profiles featuring moderate middle-level flow strength could briefly
support some convective organization along with a risk for gusty
winds. However...it currently appears that weak middle-level lapse
rates...the lack of deep-layer forcing for ascent...and the
potential for middle/high-level clouds to limit insolation and buoyancy
will keep the severe threat sufficiently low such that severe
probabilities are not included.
Farther south across the central/southern Florida Peninsula and the Florida
Keys...comparatively Richer low-level moisture will be present. A
denser middle/high-level cloud deck owing to debris cloudiness from
convection over the southeastern Gulf of Mexico and northwestern Caribbean may
inhibit insolation and the degree to which low-level lapse rates
steepen. Regardless...buoyancy should be sufficient to support a few
thunderstorms. However...weaker low/mid-level flow with southward
displacement across the warm sector should limit the intensity and
organization of convection across the central/southern Florida Peninsula and Florida
Keys.
..cntrl/southern Texas...
Minor impulses embedded within broad cyclonic flow south of the
aforementioned closed cyclone will continue to offer weak middle-level
ascent through the period. The influx of middle/high-level moisture
originating from the subtropical east Pacific...coupled with modest
instability rooted atop a layer of cool air extending from the surface
to around 700-750 mb...may support isolated elevated convection and
lightning strikes through the period. However...MUCAPE values below
500 j/kg and only modest middle-level flow strength should largely
minimize the threat for hail.
.Cohen/Goss.. 02/05/2012
Mesoscale Discussion
704
acus11 kwns 042246
sels mesoscale discussion
Storm Prediction Center mesoscale discussion 042246
alz000-msz000-laz000-050015-
Mesoscale discussion 0113
National Weather Service Storm Prediction Center Norman OK
0446 PM CST Sat Feb 04 2012
Areas affected...far southeastern la...far southeastern MS...far southwestern Alabama
Concerning...severe potential...watch unlikely
Valid 042246z - 050015z
A few storms may produce strong wind gusts into early evening across
far southeastern la...far southeastern MS...and far southwestern Alabama...with a weakening trend
expected after 01z. A ww is not needed.
A prefrontal squall line continues moving eastward around 20 knots...
currently extending from east of the Hattiesburg MS area southward toward
the east end of Lake Pontchartrain to near Grand Isle la. Low-level
ascent at the leading edge of convective outflow amidst a weakly
buoyant -- MLCAPE of 500 to 1000 j per kg -- and anomalously moist
troposphere -- precipitable water values of 180 to 190 percent of normal per blended
AMSU/SSMI data -- should allow storms to continue moving eastward along
the central Gulf Coast. Only modest amounts of deep-layer shear per
area vwp data will contribute to maintaining some convective
organization...with locally gusty winds owing to water loading
processes and weak/broad...line-embedded mesoscale circulations.
However...weak low-level flow per Mobile vwp data...the lack of
deep-layer forcing for ascent...the absence of greater
buoyancy...and the absence of a more organized cold pool will
greatly minimize any threat for severe wind gusts. After
01z...nocturnal stabilization will be associated with a reduction in
the threat for strong storms.
.Cohen.. 02/04/2012
..please see www.Spc.NOAA.Gov for graphic product...
Attention...WFO...mob...lix...
Latitude...Lon 30418780 30158816 29668875 29068918 29298980 30028962
30708926 31208880 31318826 31148779 30758771 30418780
