AWUS01 KWNH 161303
FFGMPD
CAZ000-162100-
Mesoscale Precipitation Discussion 0020
NWS Weather Prediction Center College Park MD
802 AM EST Mon Feb 16 2026
Areas affected...Southern California...
Concerning...Heavy rainfall...Flash flooding possible
Valid 161300Z - 162100Z
SUMMARY...Strong dynamics/ascent will support strengthening
moisture flux across Southern California and the Transverse Ranges
this morning with pivoting cold front allowing for slightly
increased duration of moderate rainfall with hourly rates of
.5-.75"/hr with isolated potential to 1" locally. Totals of 1-2"
along the coast and 3-5" in the terrain may result in increased
runoff for possible flash flooding and or mudslides, especially
near recent burn scars.
DISCUSSION...GOES-W depicts a compact inner core of the deep upper
low/trof continuing to dig southward near 36N129.5W with a broad
diffluent region in the northeast quadrant where the exit of a
130kt 250mb jet speed max is providing solid diffluence/divergence
aloft for expansive upper-level cirrus shield with enhancing
perpendicular transverse banding. A subtle but important embedded
shortwave along the left exit of the jet shows a the developing
baroclinic leaf just northeast of the 35N125W benchmark. This
approaching wave coupled with the digging upper-level core is
supporting surface cyclogenesis along the cold front in the
vicinity of the SLO/Monterey county offshore waters, allowing for
backing and strengthening low level flow off the California Bight
through Santa Barbara county. VWP has seen an increase of
925-850mb winds over 35kts while veering from SSE to SSW to over
50kts at 700mb. This solid WAA profile has a bit of low level
lapse rates as well to support 500-650 J/kg of MUCAPE in proximity
to the cold front toward Point Conception.=20
The overall interplay of the upper-level low and shortwave will
allow for solid negative tilting of the upper-trof providing
strong 75-90 degrees of low level directional convergence along
the front while the confluence of 850 and 700mb moisture streams
will align for enhanced moisture flux convergence bringing the
slightly below average moisture values up toward something more
average or slightly above average around 1" in total PWAT, with
CIRA LPW animations denoting this trend is on track mostly in the
surface to 850mb layer.
So with the combination of increasing flux convergence and minor
instability, pre-frontal showered and possible weak/narrow shallow thunderstorms convective cores of .75" to possible 1"/hr rates may
occur over the next few hours as the front rounds the Cape and
gets that extra bump due to steepening orographic ascent as well,
though coastal showers will still be intense capable of a quick
.5"+ rainfall total too, making urban style flooding problematic.=20
The cold front will begin to press eastward, but in the short-term
as surface low deepens, the pivot/fulcrum of rotation may allow
for overrunning showers to persist across SBA into the TROWAL
across SLO and Monterey counties for the next few hours keeping
localized totals of 2-4" possible, with some continued higher
runoff and possible localized flooding risk.
Flash flooding risk will increase, as IVT values steadily increase
from the 400 range toward 600 kg/m/s, likely peaking as the cold
front and warm conveyor belt moisture stream flow orthogonally
intersects the Transverse Range of Ventura county with HREF
probably of 1"/hr near 30% between 18-20z, with 3-5" totals
expected through 00z. As such, flash flooding is considered
possible through the remainder of the morning and into the
afternoon as it reaches the Los Angles Metro proper after 18z.=20
Gallina
...Please see
https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!95dfXy5F6loNRbNt-tcBUWF77z-5_cLiTGcwDMX-mJQ-THiN2tqReSdy2vY1Q0yF6ruy= SwLb9Vo1twaJhU1n4a2w99Y$ for graphic product...
ATTN...WFO...LOX...MTR...SGX...
ATTN...RFC...RSA...NWC...
LAT...LON 36482138 36142073 35402021 34891962 34551875=20
34521780 34001755 33261777 33361890 33732006=20
34142075 34802105 35642182 36142185=20
=3D =3D =3D
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