STORM2K

Mesoscale Precipitation Discussion 0633
NWS Weather Prediction Center College Park MD
211 PM EDT Sat Aug 11 2018

Areas affected...North Texas including DFW Metro Area

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

Valid 111809Z - 120000Z

Summary...Heavy rain bands and a few thunderstorms were beginning
to redevelop across North Texas, from Dallas-Fort Worth metro area
southwest to near Stephenville around 1 PM CDT. This storms should
persist through the afternoon, and could lead to locally heavy
rainfall. Given that some areas on the west and southwest side of
DFW metro area have received heavy rain in recent days, additional
heavy rainfall could produce flash flooding.

Discussion...GOES-16 satellite imagery clearly showed a relatively
strong MCV persisting over north Texas, centered at the moment
near KLUD (Decatur). This was sufficiently altering the wind field
to its west to produce an enhanced zone of convergence stretching
from near the MCV over the DFW metro area, southwest to near KSEP
and KMKN. This convergence zone should persist through the
afternoon hours and some recent clearing on visible satellite just
to the southeast suggests that the developing convective bands may
have access to increasingly unstable inflow. Overall, the ongoing
mesoscale setup favors increasingly organized convective bands
with potential for localized swaths of heavy rainfall in the
aforementioned area. The 12Z HREF and experimental HRRRE both
focus a small area of around 30 percent probability of exceeding
3hr FFG right in the DFW metro area. This is likely due to the
hi-res model agreement on a focused area of heavy rainfall, as
well as reduced FFG due to heavy rain in the same area in the past
couple days. The KFWS dual pol estimates show the highest rainfall
through this morning from Granbury to Fort Worth, and between
Cleburne and Hillsboro. Although heavy rainfall and localized
flash flooding will be possible over the entire outlined area,
flash flooding would tend to be favored in those two areas. GPS-PW
observations were just over 2 inches, as was the 12Z FWD sounding,
so the environment should support heavy rain rates and efficient
rainfall production.

RECORD EVENT REPORT
NATIONAL WEATHER SERVICE FORT WORTH TX
0152 AM CDT SUN AUG 12 2018

...RECORD LOW MAXIMUM TEMPERATURE SET AT DALLAS FORT WORTH...

A RECORD LOW MAXIMUM TEMPERATURE OF 78 DEGREES WAS SET AT DALLAS
FORT WORTH YESTERDAY. THIS BREAKS THE OLD RECORD OF 79 SET IN 1906.