2023 Year In Review

NOAA\NWS West Gulf River Forecast Center

A view of Abiquiu Lake surrounded by rocky slopes and with flowers in the foreground.

2023 Hydrologic Review

Looking back at 2023, precipitation would appear largely below normal for the year for the West Gulf River Forecast Center area. When looking at the annual rainfall amounts, Texas largely received around 75 to 90% of its climatologically normal rainfall amounts. The driest regions resided in far West Texas and southeast New Mexico with amounts of about 10-25% of normal rainfall. Similarly, much of New Mexico witnessed below normal precipitation and above average temperatures resulting from a weak summertime monsoon pattern this year. On the flip side, areas in West Texas and the Panhandle received above average rainfall this year as compared to below average rainfall from 2022.

2023 Percent of Normal Rainfall | 2022 Percent of Normal Rainfall (Swipe to switch between maps)

By The Numbers...

2023 was generally not considered a "wet" year, especially in comparison to most years since Hurricane Harvey in 2017. However, WGRFC did issue 684 minor and 74 moderate flood forecasts, which is about twice as many for those categories than in 2022. The number of major flood forecasts was only 18, the same as in 2022.

Bar graph showing numbers of flood forecasts issued by WGRFC and their categories between 2017 and 2023. — *Number of forecasts counting one forecast per location, per day.

The following chart shows the number of flood fatalities in the United States since 2017, as well as those only in the state of Texas. In 2017, more than half of all flood fatalities in the country were in Texas as a result of Hurricane Harvey. Since then, a much smaller percentage of flood fatalities across the country have occurred in Texas.

Bar graph showing the number of flood fatalities in the U.S. and Texas between 2017 and 2023. — Preliminary US flood fatalities based on media sources and Storm Data / NWS input.

These numbers are a constant reminder of the importance making timely and accurate forecasts, so that NWS partners and the public are informed and prepared to take precautionary actions. Remember, most flood fatalities occur in vehicles...when you come across a flooded road, Turn Around - Don't Drown!

Water Supply and Snowmelt Season

2023 Water Supply and Snow Season

What is Snow Water Equivalent (SWE)? If you were to melt snow, SWE is the amount of liquid water in that snow. Generally in drier winter months, 10 inches of snow equals about 1 inch of SWE.

Comparing 2023 to the last 10 years

When comparing the 2023 snowfall season over the last 10 years, it was the third highest for snow water equivalent, behind 2019 and 2017. Many of the other years have witnessed near to below normal snowfall, which has been reflective of this long term decrease of snowfall for southern Colorado.

Chart of snow water equivalent for the Upper Rio Grande basin compared to median and past years dating back to 2013.

Snowmelt Causes Rare Flooding on Jemez River near Jemez Springs

Hydrograph of the Jemez River reaching minor flood stage during 2023. — Hydrograph of streamflow observations from March 1st through April 30th, 2023.

River flowing out of its bank near Hwy 4 in New Mexico. — Out of bank flow along Highway 4

Upstream view of Jemez River in Jemez Springs, NM — Upstream view of Jemez River in Jemez Springs

Description of historic flooding on the Jemez River with a photo of the river and its hydrograph over 2023.

Image of overbank flooding of agricultural field north of Jemez Pueblo

Notable Flood Events

May 10-15:

Moderate/Major Flooding along Guadalupe and Nueces

image of park bench and green space with floodwater inundation up to the seat

In the midnight hours of May 9, heavy rains began in the Oso Creek basin slowly moving through the area over the next 12 hours. Early the next morning, the system entered the upper Victoria basin and produced significant rainfall in the following 24 hours.

a gif progression of the radar storm intensity as it moved across affected areas just south of Houston in the early morning of May 10

Over the next few days, the flood wave made it's way down stream with the gage site at Victoria on the Guadalupe River (VICT2) cresting a little over 18-ft on May 17th.

Significant impacts to the area included closures at Riverside Park, boat ramps, several major and secondary roads, and an RV park.

A hydrograph is shown of the observed river rise and forecast comparison between the RFC and National Water Model

Aug 22-24:

Major Flooding along Rio Grande

a satellite image of Tropical Storm Harold advancing into Texas from the Gulf of Mexico with state boundaries displayed in white

Forecasters monitored Tropical Storm Harold as it developed off the coast of Texas in the Gulf of Mexico before making landfall on August 19. Over the next several days, the system moved inland over the Southern tip of Texas and across the Mexican-American border.

The most significant flooding occurred at Rio Grande near Foster Ranch (LYNT2) which received the heaviest rainfall over the lower part of the basin. This site eventually crested just below 24-ft on August 23rd.

a gif progression of the radar storm intensity as Tropical Storm Harold moved across affected areas along the Rio Grande on August 22

Oct 25-30:

Moderate/Major Flooding along Trinity and Brazos Rivers

Image shows rapid and deep floodwaters moving through the Bosque River channel barely underneath a bridge with vehicular traffic, pushing large trees with the current

As the Pacific system, Hurricane Otis, made landfall and dissipated across Texas, an additional frontal system streamed into the area from the Northwest creating the perfect conditions for isolated pockets of extreme precipitation.

Significant rainfall began on October 25th continuing through the 28th with multiday totals reaching 10-15 inches in isolated areas.

a gif progression of the radar storm intensity as it moved across affected areas in central Texas in the early hours of October 26

River responses began overnight with the basins receiving heaviest rainfall totals quickly reaching moderate or major flood stage.

Along the Brazos at the North Bosque River near Clifton (CTNT2), two waves of rain caused separate rises over the course of the event with a final crest of 32.92-ft on October 28th.

The Trinity River near Rosser (RSRT2) maintained a consistent rise in spite of rolling storms of heavy precipitation. This location's crest maxed out at 35.37-ft on October 29th.

Impact-based Decision Support Services (IDSS)

Daily Graphics

In addition to our official river forecasts throughout the year, WGRFC continued to create images with the most important message of each day for distribution on our website, social media, and during briefings with our partners. Click around the images below, which highlight some of the year's most significant events, from river flooding to drought and water supply.

A map of rainfall amounts and river locations forecast to flood. — WGRFC 2023 decision support image highlights

A chart showing snow water equivalent values for the Rio Grande headwaters. — WGRFC 2023 decision support image highlights

New(!) NWS Flood Inundation Mapping Services

In an exciting new development for the communication of flood impacts, NWS has implemented public experimental Flood Inundation Mapping (FIM) services for 10% of the nation (including much of Texas) this past October. These services will be implemented for the entire nation by October 2026.

A map of the United States colored by regions that will have flood inundation map services available by different dates.

All of these new FIM services, listed below, are based on the National Water Model (NWM):

NWM Latest Analysis Inundation Extent
- "Snapshot" of current modeled inundation extent
RFC 5-Day Maximum Inundation Extent Forecast
- Available at stream reaches with official RFC forecast hydrographs
NWM 5-Day Maximum Inundation Extent Forecast
- Available at all NWM stream reaches

Image of a flood inundation map near Junction, Texas.

These new FIM Services are viewable via the NWS GIS Viewer embedded here. Zoom in, edit the layers, and click around the map; or click the map's title in the upper right to open in a new tab.

For more information:

Storymap: NWS FIM Services

The NWS FIM services are also available to view in the Interagency Flood Risk Management (InFRM) Flood Decision Support Toolbox (FDST).

This tool combines a large library of high-quality, static FIM products in Texas with the new dynamic NWS FIM services.

WGRFC forecasters are at the ready to help our partners interpret the various available FIM products when heavy rainfall approaches and the rivers are forecast to rise!

Flood Decision Support Toolbox

Drought and El Nino

With La Niña in place the year prior, ongoing drought conditions made their way into the start of 2023. La Niña, typical of warmer and drier weather especially during the winter months, gave 2023 an unfair advantage despite El Niño conditions ramping up during the spring months. Not only did El Niño affect the drought, but it also had impacts on our tropical and monsoon seasons.

2023 Drought

The lack of rain and persistent ridge of high pressure maintained warm and dry conditions through the summer of 2023, which led to worsening drought conditions across the West Gulf River Forecast Center.

By September 2023, the Drought Severity and Coverage Index (DSCI) peaked at nearly 328 out of a possible 500. However, relief did come as the late fall and winter months approached due to several bouts of rainfall across the region. Those areas that received rain also saw improvements to the drought.

A revolving gif of the 2023 monthly updates to the drought monitor across the West Gulf River Forecast Center region. Images used were from the first-Thursday of every month. Drought continues from 2022, worsening during the late summer-early fall months, initially across Texas then across New Mexico and Colorado, due to lack of rain and oppressive heat.

Despite the bouts of rain through 2023, overall, there remained areas where departure from normal rainfall was several inches below normal.

Rainfall image showing 2023 rainfall totals ranging from near 40-60 inches of rainfall across much eastern Texas to less than 15 inches across much of western Texas, New Mexico, and Colorado.n

Image of the rainfall departure from normal across WGRFC. Anywhere from 2-16+ inches deficit for the majority of the WGRFC area, especially across SE Texas.

El Niño

Effects from El Niño are typically felt during the late fall and winter months, when the increased rainfall activity across the equatorial Pacific Ocean help influence the Pacific jet stream to sink farther south in latitude bringing cooler and wetter weather to the southern CONUS.

With the year transitioning from La Niña early in the year to El Niño by the summer, rainfall opportunities picked up during the late Fall to Winter months.

El Nino Winter: Map of the U.S. depicting Low pressure across the eastern Pacific Ocean. North of the area of low pressure is warm air moving across Alaska, western Canada, and into the northern CONUS, with drier conditions south of the Great Lakes region, as the Polar Jet Stream is shifted north. Meanwhile, the Pacific jet stream flows south of the area of low pressure across the southern CONUS, bringing cooler and wetter weather.

Tropical Season

2023 Atlantic Hurricane Season

Despite the ongoing El Niño during the middle of summer, the 2023 Atlantic Hurricane Season was rather active with 20 storms (19 named, 1 unnamed). Out of those 19 named storms, 7 storms became hurricanes, with 3 of those hurricanes reaching major hurricane status (Category 3 or higher).

Map of tracks of tropical systems across the North Atlantic Ocean. The majority of the tracks remained across the Atlantic, with 5 systems impacting the US and US territories.

Typically in an El Niño year, increased vertical wind shear and trade winds in the mid-upper atmospheric levels lead to suppressed tropical activity. This was seen over the Caribbean and Gulf of Mexico in summer 2023. During a La Niña year, weaker wind shear tends to lead to increased hurricane development.

Image of Typical El Nino Influence across the USA. Yellow highlighted area across Mexico and Baja California indicating area of more hurricanes due to less wind shear. Blue area across the Caribbean Sea indicating fewer hurricanes due to stronger wind shear. Brown/Teal area across the equator west of South America indicating warm and wet conditions.

Image of typical La Nina influence for USA. Blue area across Mexico to Baja California indicating fewer hurricanes due to stronger wind shear. Yellow area across the Caribbean Sea indicating more hurricane development due to less wind shear. Blue and brown area across the equatorial region west of South American indicating cool and dry conditions.

However, another natural occurring phenomena known as the Atlantic Meridional Oscillation (AMO) was also ongoing across the eastern Atlantic. This oscillation aided in tropical development, especially in the warm waters across the eastern mid-Atlantic.

During the warm phase of the AMO, hurricane activity increases.

Comparison of hurricane tracks during cool and warm phases of Atlantic Meridional Oscillation (AMO). During cool phases, there are less hurricane tracks, and during warm phases there are more hurricane tracks.

The AMO has currently been in a warm phase since 1995. This has led to the increased activity across the Atlantic, but due to the increased wind shear periods due to El Niño, there was slightly less activity across the Caribbean and Gulf of Mexico.

Non-soon Monsoon

Monsoon Season

The monsoon season across New Mexico was very slow to start and not a typically observed season. The saying goes, "Drought begets drought", and with ongoing drought and strong high pressure settled over the region, it was going to be a tough time to see those typical rain storms that New Mexico really needed.

The image to the right shows that from June to September 2023 the composite mean of the 500 millibar geopotential heights. For the most part, upper level ridging was a big player in the drought and drier conditions for New Mexico. Some weakening was observed during the months of July and August with a gradual uptick in observed rainfall across southern and southwestern New Mexico.

Image of the 500 mb Geopotential Height (m) Composite Mean across North America for the 2023 months of June, July, August, September. The images reflect upper level high pressure dominated much of the southern CONUS during the summer period.

As a result, the warmest monsoon season was recorded for Albuquerque for 2023, with 2023 also being the 10th driest monsoon season for Albuquerque.

For more information on the 2023 Monsoon Season, check out NWS Albuquerque's presentation at: https://www.weather.gov/media/abq/Briefings/Monsoon2023.pdf

Top 18 Warmest Monsoon seasons for Albuquerque with a record of period of 1891-2023. The year 2023 was the warmest monsoon season on record at 79.4°F.

Top 18 Driest Monsoon seasons for Albuquerque with a record of period of 1891-2023. The year 2023 was the 10th driest monsoon season on record with 1.92 inches of rain..

Thank you for reading!

Wide photo of a river with rocky terrain on either side. — Brazos River below Possum Kingdom Lake, Texas