Flooding Possible TXLAMS
From
Mike Powell@618:250/10 to
All on Fri May 8 08:09:36 2026
AWUS01 KWNH 081146
FFGMPD
MSZ000-LAZ000-TXZ000-081700-
Mesoscale Precipitation Discussion 0163
NWS Weather Prediction Center College Park MD
745 AM EDT Fri May 08 2026
Areas affected...Southeast Texas...Southern Louisiana...Southwest Mississippi...
Concerning...Heavy rainfall...Flash flooding possible
Valid 081145Z - 081700Z
SUMMARY...Early morning elevated thunderstorms with potential to
train this morning pose narrow axis of 2-4" totals and isolated
flash flooding concerns near urban and areas of recent heavy rainfall.
DISCUSSION...GOES-E WV suite depicts a broad positive tilt closed
low across the southwest with a nicely shaped anti-cyclonic
downstream shortwave ridge across central TX into confluent flow
regime across the Lower Mississippi Valley into the Tennessee
Valley. This places the surface front stalled along south and
parallel of the Texas Gulf Coast before angling northward to a
weak surface wave south of Houma, LA. CIRA LPW denotes the
anomalously high sfc to 850mb moisture pooled along and north of
the front generating a very tight gradient across southeast TX and
across central LA. The 850-700 and 700-500mb layers are also
complimentary to total PW values aligned across the area of
concern that values of 1.75-2" exist between the surface front and
the surface coastal pressure trof that goes from KNOG to KTME
before crossing that tight PW gradient near KJAS to KAQV in western LA.
Surface to boundary layer onshore flow is providing weak but
sufficient WAA before veering to the southwest through the 850mb
layer to provide sufficient convergence and isentropic ascent
across the boundary to access the larger well of conditionally
unstable air with MUCAPES of 1000-1500 J/kg...which extends
eastward along and south of the PW gradient along and north of
I-10 through E LA into S MS. As such, RADAR and GOES-E 10.3um
depicts solid convective initiation along and south of the tight
gradient which further helps to steepen vertical ascent plane.
The overall depth of moisture is already supporting isolated to
scattered .5-1"/hr rates but this will continue to increase with
coverage and moistening of the mid-level profiles. Additionally,
with some surface heating, a few nearer surface based cells with
higher rate potentials to 1.75-2"/hr may develop over the next 3-4
hours along or even south of the I-10 corridor.
As mentioned, the deeper layer flow flattens west to east into the
confluence downstream generally parallel to the boundary/ascent
plane to support a favorable opportunity for repeating/training
(especially further east into LA). This may allow for narrow
streaks of 2-3+", with an isolated 4" total not out of the realm
of possibility. Generally sandy soils and naturally high FFG in
the region from overall drought should help to mitigate most of
the heavy rainfall. However, there are is a axis of reduced FFG
values especially from Vernon to Rapides to Concordia parish in LA
and portions of SW MS that are recovering from heavy rainfall
36-48rs ago as well as a number of prone urban centers along the
area of concern that would be more susceptible to possible
incident or two of localized flash flooding this morning.
Gallina
ATTN...WFO...FWD...HGX...JAN...LCH...LIX...SHV...
ATTN...RFC...FWR...ORN...NWC...
LAT...LON 31669219 31519034 31208953 30788938 30308968
30129069 30159225 30159283 30059469 30149581
30449631 30959639 31329594 31559489 31629321
$$
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* Origin: Capitol City Online (618:250/10)