South Texas Weather Forecast
Weather forecast for May 18, 2018
May 1821, 2018
Daily Weather Forecast
South Texas Weather Modification Association

Upper air analysis shows a trough of low pressure across the southwest along the Great Basin
with a ridge of high pressure across the deep south and a trough over the southeast. At the
surface, low pressure continues to be centered across the Rockies with high pressure over the
Gulf of Mexico.  The flow at upper levels is generally from the northwest with it being mainly calm
at the surface.  The current dew point temperature is in the mid 60’s with patchy fog in the
vicinity.  For today, high pressure ridge will continue to dominate our weather bringing dry and
hot conditions throughout the day.  Expect similar conditions as yesterday with mainly sunny
skies and the temperatures way above average.  High pressure aloft will shift slight to the east
allowing for southwesterly flow.  At low levels, the flow becomes southeasterly that will cause the
high temperature to drop a degree of two from yesterday.  The upper level ridge will block any
convection that forms across the high terrains of northeastern Mexico and west of Edwards
Plateau to enter the target areas today. The ridge will continue to dominate our weather on
Saturday bringing again warm and hot conditions except for the high temperature being a few
degrees lower than today’s high. Come Sunday, a cold front drops in across the central Texas
that will bring a low chance for precipitation all the way into Monday as the front stalls.  Better
showers and thunderstorms chances will be north of the target areas, but a few isolated storms
are possible across our region.  

STWMA:                                

Daily Normal (Pleasanton): High 87, Low 66                
               
Pilots (STWMA): No ops are expected today.
                                                               
Forecast (Pleasanton):         
                                               
Today: Mostly sunny skies with winds light and variable becoming southeast between 5 and
15mph. Areas of patchy fog before 9 a.m. High temperature of 98°F.
                               
Tonight: Partly cloudy skies with winds between 5 and 10mph.  Low temperature of 72°F.
                                                       
Saturday: Partly sunny skies with winds from the southeast between 10 and 15mph with possible
gust up to 20mph.  High temperature of 94°F. Overnight, mostly cloudy skies with winds from the
southeast between 10 and 15mph with possible gust up to 20mph. Overnight low temperature of
75°F.
                                                               
Sunday: Partly skies with winds from the east southeast between 5 and 15mph with possible
gust up to 20mph.  Slight to low chance for showers and thunderstorms. High temperature of 91°
F. Overnight, mostly cloudy skies with winds from the southeast between 10 and 20mph. Slight
to low chance for showers and thunderstorms. Overnight low of 73°F.

Monday: Mostly cloudy skies with winds from the southeast between 5 and 10mph. High
temperature of 89°F. Slight to low chance for showers and thunderstorms. Overnight, mostly
cloudy skies with winds from the east southeast between 5 and 10mph. Slight to low chance for
showers and thunderstorms.  Overnight low of 71°F.
               
Extended: There will be a slight chance for showers on Tuesday as the cold front diminishes.
For the rest of the week quiet conditions are expected as the subtropical ridge of high pressure
rebuilds across the southern plains.

Forecast Notes:
Temperatures are in Fahrenheit (F)
Wind speeds are in miles per hour (mph)
Rainfall amounts in inches (in.)
Convective Available Potential Energy (CAPE)
Convective Inhibition (CIN)
South Texas Weather Modification Association