Area Forecast Discussion
Issued by NWS Austin/San Antonio, TX

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS64 KEWX 151147 AAA
AFDEWX

Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
647 AM CDT Sun Sep 15 2019

.AVIATION...
/12Z TAFS/
VFR conditions are forecast for the area terminals for this cycle.
Light and variable winds are forecast for the next several hours
before picking up to average 6 to 10 knots through this evening. An
east to southeast wind flow is forecast for most of today and evening
and returning to a light and variable flow late tonight into Monday
morning. A surface low pressure system could be forming over the
northwest Gulf of Mexico on Monday morning to bring chances of rain
across the Coastal Plains. For now, there no impact associated with
this possible disturbance over area sites, however, we could be
introducing in future packages showers and storms as the system comes
closer to the Texas Coast sometime between Monday evening and early
Tuesday morning.

&&

.PREV DISCUSSION... /ISSUED 312 AM CDT Sun Sep 15 2019/

SHORT TERM (Today through Monday)...
Another mostly clear and relatively mild night is ongoing across
South-Central Texas at the present time. Drier air for the western
half of the area remains in place and this has allowed temperatures
to fall into the upper 60s to lower 70s for these locations. Middle
to upper 70s prevail for the eastern counties. A weak low-pressure
system remains in the western Gulf of Mexico and therefore all
rainfall activity for today will remain to our southeast. Otherwise,
highs today should be a degree or two cooler than yesterday as upper
heights continue to slowly fall over our area. For Monday, the
system should be nearing the coastline and will show 20-40 PoPs for
most of the region as some mainly afternoon showers and storms will
be possible. Highs on Monday should be another degree or two cooler
compared to today.

LONG TERM (Monday Night through Saturday)...
The focus of the long-term forecast will continue to be on the system
in the Gulf of Mexico. The latest tropical weather outlook from the
National Hurricane Center shows only a 20 percent chance of
development into a tropical cyclone before the system moves onshore
Monday night and into Tuesday. Regardless if this system has a well-
defined low-level center, the moisture associated with this low
should bring us prolonged rain chances to our region. The main
question of today is how much rain will be possible next week?

The GFS and ECMWF have much different solutions regarding the
handling of the mid-upper level low centers once the system moves
onshore. The GFS wants to weaken and eventually dissipate this
feature as it moves onshore while the ECMWF maintains the low and
slowly moves it through the CWA Tuesday through Thursday. While the
GFS does show elevated PoPs through the week with the increase in
moisture, the rainfall amounts would not be nearly as high as what
the ECMWF is progging. The Canadian model does develop the system
into a cyclone which then limits the precip on the backside of the
system, but for this forecast package will not give much weight to
this outcome due to more of a consensus of the most reliable global
models for tropical weather not showing development. Through Friday
the GFS is showing 1 to 2 inches of QPF across portions of the CWA
while the ECMWF shows 3-4 inch rains along and east of I35. Taking a
look at the GFS ensembles offers no consensus as most members have
even less amounts of QPF than the operational runs. In fact, the
operational run of the GFS is by far the most wet of the ensemble
group. Until confidence increases on the possible ECMWF solution
verifying, will keep PoPs at 60 percent or less for most days next
week. These PoPs could be increased if confidence increases of the
upper low maintaining itself over land. Regardless of which solution
verifies, we will welcome the cooler temperatures that comes with the
increase in cloud cover and elevated rain chances after the brutal
August and first part of September that we have had. Highs in the
extended are forecast to be in the upper 80s to middle 90s with lows
in the lower 70s.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              99  76  96  75  94 /   0   0  20  10  40
Austin Bergstrom Intl Airport  99  73  95  73  93 /   0   0  20  10  40
New Braunfels Muni Airport     97  73  95  73  93 /  -    0  30  10  40
Burnet Muni Airport            95  72  94  72  92 /   0   0  10  10  30
Del Rio Intl Airport           98  73  97  74  97 /   0   0  10  -    0
Georgetown Muni Airport        98  73  96  73  94 /   0   0  20  10  40
Hondo Muni Airport             98  72  95  73  95 /  -    0  20  10  30
San Marcos Muni Airport        98  72  95  72  93 /  -    0  30  10  50
La Grange - Fayette Regional   99  74  95  74  95 /  -   -   30  10  50
San Antonio Intl Airport       97  75  95  75  93 /  -    0  20  10  40
Stinson Muni Airport           97  75  94  75  93 /  -    0  30  20  40

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

Aviation...17
Short-Term/Long-Term...Hampshire


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.