158 

AWUS01 KWNH 060411

FFGMPD

TXZ000-061000-



Mesoscale Precipitation Discussion 0332

NWS Weather Prediction Center College Park MD

1209 AM EDT Sat Jun 06 2026



Areas affected...Central Texas/Hill Country



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



Valid 060409Z - 061000Z



SUMMARY...Very efficient showers and thunderstorms will persist

and regenerate across central Texas into the overnight hours.

Extreme rainfall rates of 2 to 3 in/hr are possible which may

result in localized additional rainfall amounts of 3 to 4+ inches.

Flash flooding is possible.



DISCUSSION...Recent regional radar imagery and GOES-E Proxy

Visible satellite trends show an active, but broken area of

slow-moving showers and thunderstorms impacting portions of

central Texas and the Hill Country. This activity is being

sustained by a highly anomalous and deep tropical moisture axis

and subtle deep layer ascent. Recent 00Z RAOBs and OSPO/CIRA ALPW

data indicate a dual-feed moisture tap with modest low-level

moisture transport originating from the Gulf which is being

superimposed by a deep mid to upper-level moisture contribution

from the eastern Pacific given deeper layer southerly flow.



The synoptic and mesoscale forcing mechanisms, while subtle in the

lower levels, are highly supportive of sustained ascent. A subtle

surface trough is currently draped across the region, providing

the necessary low-level convergence. Aloft, the upper-level flow

is becoming increasingly divergent ahead of a deep-layer trough

over the southern High Plains. When combined with a moderately

unstable thermodynamic profile characterized by 1000 to 2000 J/kg

of MUCAPE, robust and persistent updrafts will continue to blossom.



The primary hazard tonight is the extreme rainfall efficiency of

these updrafts. With PWATs analyzed between 2.0 and 2.25 inches

and a very deep warm cloud layer in place, warm-rain

collision-coalescence processes will dominate. This will easily

support torrential rainfall rates of 2 to 3 in/hr.



While the 00Z REFS guidance appears considerably underdone and out

of touch with ongoing observational trends, the latest

high-resolution HRRR and the 00Z HREF suite are in much better

agreement with the current radar presentation. Relying on the

HREF/HRRR consensus, the expectation is for these highly efficient

storms to produce localized additional rainfall totals of 3 to 4+

inches overnight. Given the intensity of the hourly rates,

isolated to scattered instances of flash flooding will remain a

threat through the early morning hours.



Orrison



...Please see www.wpc.ncep.noaa.gov for graphic product...



ATTN...WFO...EWX...FWD...HGX...SJT...



ATTN...RFC...FWR...NWC...



LAT...LON   32279745 32189668 31659620 30879615 30149649 

            29599735 29539817 29999867 30789860 31619820