Area Forecast Discussion
Issued by NWS San Angelo, TX
FXUS64 KSJT 301044 CCA
Area Forecast Discussion
National Weather Service SAN ANGELO TX
543 AM CDT MON MAY 30 2016
(Today and Tonight)
A band of thunderstorms with moderate to heavy rainfall was over our
southern counties and was near the I-10 corridor early this morning.
This band of storms will slowly exit our southern counties by or
shortly after sunrise. The inherited Flash Flood Watch for the
southern part of our area is in effect until 10 AM this morning.
A very slow moving upper low will be over southwestern Arizona today
and tonight. With southwest flow aloft ahead of this system, the
models indicate another embedded disturbance entering our area
tonight. With a moist and unstable airmass, convection should
develop to our west and southwest during the late afternoon and
evening, and then track across our area tonight. We are carrying 30-
50 PoPs for this scenario tonight, with the highest rain chances
across the western part of our area. With weak low-level jet
development and precipitable water values of 1.2 to 1.5 inches,
locally heavy rainfall will be possible. The ground is becoming
saturated across an increasingly large part of our area, and
additional heavy rainfall could result in localized flooding. The
expected coverage and duration should be limited enough to preclude
the need for a Flash Flood Watch for now, but this is something we
are monitoring. A few strong storms will be possible late this
afternoon into tonight with hail and gusty winds. However, the
severe weather threat is expected to be lower than yesterday.
(Tuesday through Sunday)
The aforementioned upper low will move very slowly east along or
just south of the southwest U.S. and Mexico border Tuesday and
Wednesday, and into southeastern New Mexico Wednesday night. With
the gradual approach of this system, the chance for showers and
thunderstorms will continue Tuesday and Tuesday night, increasing
Wednesday and Wednesday night.
From early Thursday to Friday evening, the upper low is progged to
continue a very slow movement from southeastern New Mexico to
central or south-central Texas, and then drifting into Deep South
Texas or the lower Rio Grande Valley next weekend.
A weak cold front progged to enter our area Wednesday into early
Thursday could provide a focus for convective development. With
increased large scale ascent and precipitable water values remaining
generally in the range of 1.2 to 1.6 inches, anticipate more
widespread coverage of showers and thunderstorms, with additional
heavy rainfall Wednesday through Thursday. Given the model forecast
and recent rainfall trends across our area, a Flood or Flash Flood
Watch will need to be considered in the coming days.
Temperatures will be cooler following the cold frontal passage.
Unless the models trend faster with the forecast track of the
upper low across Texas, our rain chances will continue through the
end of this week and possibly linger into next weekend.
.PRELIMINARY POINT TEMPS/POPS...
Abilene 85 67 85 66 / 20 40 50 70
San Angelo 87 68 87 67 / 30 50 40 50
Junction 87 68 83 68 / 50 40 50 60
Flash Flood Watch until 10 AM CDT this morning for Kimble-Mason-