Area Forecast Discussion
Issued by NWS San Angelo, TX
FXUS64 KSJT 181131
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
631 AM CDT Sat Apr 18 2015
Two upper level disturbance will bring a round of storms to most
TAF sites this morning and again this afternoon. Latest radar data
is showing an area of storms moving east and northeast towards
KSOA and KJCT and could reach those sites between 12Z and 15Z.
Main impacts will be gusty winds, brief heavy rain, lightning and
low visibilities. The IFR Cigs should gradually improve to VFR shortly
after 15Z. The next round of storms may form along the dryline
after 18Z at KSOA, KBBD and KJCT. A few of these may become severe
and produce large hail, damaging winds and very heavy rainfall.
.PREV DISCUSSION... /ISSUED 420 AM CDT Sat Apr 18 2015/
(Today and Tonight)
There is a threat for severe thunderstorms across the eastern half
of West Central Texas today as an upper level trough associated with
the upper low near the Four Corners moves across the region. The
main threats will be large hail and damaging winds. SPC has placed
much of the area east of the dryline in a slight risk for severe
Latest radar is showing showers developing across the mountains in
northern Mexico, south of Sanderson, in association with the next
approaching shortwave as can be seen on water vapor satellite
imagery. This could bring a round of showers and thunderstorms to
West Central Texas this morning before the main upper trough moves
across later this afternoon.
The dryline is forecast to move east today as the RUC model progs
this front from Haskell to just east of San Angelo to Sonora by
early evening. This dryline should trigger scattered thunderstorms
this afternoon as the following ingredients come together: dewpoints
ranging from the upper 50s to the lower 60s, moderate 0-6km shear,
MU CAPE Values 1500-2000 J/KG, a weak capping inversion, approaching
upper trough and a right rear entrance region of the southern stream
upper level jet flowing across the area. These parameters should
set the stage for the development of a few supercells today,
resulting in large hail and damaging winds. These storms may
continue into the early evening hours before dissipating.
Highest Pops were placed across the Northwest Hill Country extending
north to Brownwood. Went closer to the warmer MAV MOS for
temps as the dry warm air invades the western part of the region
(Sunday through Friday)
Cold front will move through Sunday. Dry southwest to west winds
ahead of the front will not only preclude rain chances, but also
give a boost to temperatures, being downslope compression. Still,
cold advection will bring cooler temperatures Sunday, with highs
in the 70s.
Isolated dryline thunderstorms possible mid and late week. West
Central Texas will be under a broad upper ridge, so widespread
showers or thunderstorms not expected. Could see a few highs
approach 90s, especially Wednesday and Thursday.
.PRELIMINARY POINT TEMPS/POPS...
Abilene 82 55 79 49 72 / 30 20 5 5 5
San Angelo 84 54 82 50 75 / 30 10 5 5 5
Junction 82 56 85 52 75 / 50 30 5 5 5