Mesoscale Precipitation Discussion 1045
NWS Weather Prediction Center College Park MD
731 PM EST Fri Dec 07 2018

Areas affected...Central Coastal Plain of Texas

Concerning...Heavy rainfall...Flash flooding possible

Valid 080030Z - 080545Z

SUMMARY...Warm sector enhanced convection with potential for
repeat tracks, may lead to isolated flooding/flash flooding
through the evening and into the early overnight hours.

DISCUSSION...GOES-16 WV suite depicted  leading edge of greatest
height-falls  approaching across South Texas late this afternoon. 
This has led to a favorable eastward shift of the ridge axis and
placement of the warm sector across the coastal plain of Texas to
be within the right entrance to the 90kt 3H jet streak enhancing
vertical ascent and strengthening of low level inflow fairly
orthogonal to the frontal zone draped from N of ALI to VCT.  This
jet was also helping to deepen a surface wave along the front
northwest of the Houston Metro area.  Sfc inflow of 15-20kts near
CRP is advecting high Theta-E air (70F Tds) off the Western Gulf,
with 00Z radiosondes showing precipitable water values ranging
from 1.62 inches at LCH to 2.1 inches at CRP. While cloud cover
limited solar insolation during the afternoon, temperatures in the
mid 70s supporting 750-1250 J/kg of SBCAPEs with consistent
replenishing flow, though slowly veering with time. 

Limiting factor is clearly dry antecedent conditions across the
region, though reduced soil infiltration due to transition to
winter ground conditions may support more runoff than FFG values
would suggest, still flash flooding will continue to be possible,
although limited in scale and coverage.   Even the most aggressive
Hi-Res CAMs such as the GEM-Regional, HRRR and HRRR-Experimental
have been indicating another 2 to 3 inches in areas close to the
coast through 06Z.

Bann

ATTN...WFO...CRP...EWX...HGX...LCH...

ATTN...RFC...WGRFC...

LAT...LON   30879424 29959362 29449460 28819556 28539622
            28519711 29379726 30159647