Hi, everyone, and welcome to
the Texas Water Development Board's latest Water and Weather report.
I'm Dr. Mark Wentzel,
a hydrologist in the Surface Water Division here at the agency.
And today, we’ll
be taking a look at conditions for our state at the end of March 2023.
Let's take a look at some of the big water and weather headlines.
La Niña conditions, cooler-than-average sea surface temperatures
in the eastern equatorial Pacific, dissipated during the month of March.
La Niña is at least partially responsible
for drought conditions in Texas over the past two and a half years.
That switch to neutral conditions came too late in the month
to make a difference just yet.
Temperature was above average for about half the state
and precipitation remained below average for most of the state in March.
Drought conditions expanded from covering 62 percent of the state
at the end of February to 67 percent at the end of March.
Statewide, storage in our water supply reservoirs is 74.6 percent of capacity,
down about half a percentage point from the end of last month
and 10 percentage points below normal for this time of year.
Let's take a closer look at drought conditions at the end of March.
The drought map for conditions as of March 28 shows 67
percent of the state impacted
by drought, up five percentage points since the end of February.
East Texas remains relatively drought free,
but most of the central part of the state from deep south Texas to the Panhandle,
is experiencing moderate or worse drought.
Some of the worst hit counties are in the northern
tip of the Panhandle and north and west of San Antonio.
Let's take a closer look at what the switch from La Niña
to neutral conditions could mean for south central Texas.
But first, a quick recap on what we mean by
La Niña, neutral, or El Niño conditions.
This graphic shows how sea surface temperatures in the equatorial Pacific
Ocean differ from their long-term average values.
When the sea surface is cooler than normal in the boxed area
shown in blue, La Niña conditions are present.
When the sea surface
is warmer than normal, shown in orange and red, El Niño conditions are present.
When temperatures are near normal, conditions are described as neutral.
Why are La Niña, neutral, and El Niño conditions important to Texas?
Each of these conditions sets up different atmospheric circulation patterns
that impact weather around the world, including Texas.
This graph shows how precipitation for south central Texas
is influenced by these conditions for the month of April, May, and June.
Rainfall totals
for these three months vary even for years with the same conditions,
but El Niño years tend to be wetter than neutral years,
which tend to be wetter than La Niña years.
The switch from La Niña to neutral conditions in the last month
means this part of the state can expect
to receive 1 to 2 more inches of rainfall in the next three months.
That's not enough to remove
drought conditions in hard hit areas, but it's a move in the right direction.
Statewide, what can we expect over the next few months?
The latest seasonal drought outlook from the National Weather
Service is optimistic for the eastern half of the state.
Through the end of June,
they expect drought to contract and dissipate on that side of the state.
On the western side of the state, drought is expected
to continue to expand, covering all of West Texas by the end of June.
Looking a little farther out, El Niño conditions are expected
this fall and should bring improved drought conditions to the entire state.
That concludes our report.
Until next time, I hope you all stay healthy and safe.