Persistent dry conditions across the Rio Grande Valley/Deep South Texas region led to further degradation of drought conditions. A large spot of Exceptional (D4) Drought developed in a local rain desert mainly in Northern Hidalgo and Brooks County, and D4 expanded across all of the Rio Grande Plains to western Jim Hogg and Starr Counties.
Every event with a place to put it; 9 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS BRO wrote it up.
Persistent dry conditions across the Rio Grande Valley/Deep South Texas region led to further degradation of drought conditions. A large spot of Exceptional (D4) Drought developed in a local rain desert mainly in Northern Hidalgo and Brooks County, and D4 expanded across all of the Rio Grande Plains to western Jim Hogg and Starr Counties. Impacts began to be felt on livestock and dryland crops as temperatures warmed and evaporation rates increased with with the rising sun angle.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Brownsville, TX wrote its last area forecast discussion before the first event at Mar 22, 11:30 PM CST, 30 minutes earlier.
Area Forecast Discussion...UPDATED National Weather Service Brownsville TX 1230 AM CDT Tue Mar 23 2021 .DISCUSSION...Updated for latest aviation discussion below. && .AVIATION...MVFR ceilings are expected tonight as a weak frontal boundary approaches and low level moisture increases. Patchy fog is possible near daybreak, but not expected to become dense across the RGV at this time. Expect a northerly wind shift this morning with the front, turning more easterly with VFR ceilings this afternoon, and eventually southeast again late Tuesday. Patchy fog is more likely Tuesday night, just beyond this TAF period. && .PREV DISCUSSION... /issued 745 PM CDT Mon Mar 22 2021/ DISCUSSION...Updated for latest aviation discussion below. AVIATION...The 00z BRO sounding shows a shallow moist layer from around 850-900 mb with plenty of drier air in place aloft. As the low level flow decreases later tonight, expect general MVFR ceilings to persist throughout the overnight hours. Some brief reductions to IFR levels will be possible later tonight into early Tues morning. A weak cold front moving through the RGV tomorrow morning will allow drier air to move into the region improving ceilings back up to VFR levels later in the current TAF package. PREV DISCUSSION... /issued 251 PM CDT Mon Mar 22 2021/ SHORT TERM (Now through Tuesday Night): Winds have increased across much of the CWA this afternoon due to a tightening pressure gradient, with strong low pressure developing in the Plains. Anticipate southeast wind gusts between 35 and 40 mph, mainly across the mid and lower Rio Grande Valley/Willacy County, through the remainder of the afternoon. A Wind Advisory remains in effect for Cameron and Willacy counties until 8 PM CDT. Winds will gradually decrease this evening as a very weak frontal boundary approaches from the northwest. The front is still forecast to push through Tuesday morning, although latest deterministic and hi-res models show the front slowing down and even washing out as it pushes through the area. This has made the afternoon forecast package somewhat challenging with regards to Tuesday temperatures and dewpoint temperatures/relative humidity values. There is a slight chance of some light showers and perhaps a rumble of thunder or two along the front, especially near the coast, but best chances will occur over the coastal waters. Even with the weak front, high temperatures will still reach the mid- upper 80s and lower 90s (west) on Tuesday afternoon. Slightly cooler temperatures will be felt Tuesday night, when lows drop into the low-mid 60s. Patchy to areas of fog may be possible late tonight as winds drop to near calm across the area, as well as on Tuesday night as the front lifts back north as a warm front. LONG TERM (Wednesday through Monday): Enhanced wildfire growth and spread threat will be a big concern early in the long term. Drier air will filter into western sections on Wednesday as a dry cool front approaches. The GFS even manages to bring north winds into the Upper Valley on Wednesday afternoon, but this may be more a reflection of lower pressure over North Central Mexico. 20 ft. winds will likely be below criteria for fire weather products at this point. Nonetheless, it will be warmer than normal, with highs in the 80s along the coast and mid to upper 90s far west. The GFS and ECMWF are in better agreement today with the timing of a front, and both bring increasing northwest winds to the coast around mid-Thursday morning. Most of the energy with this Thursday front will be north of the area, and drier air will get pulled in from the west once again. It is now looking like the CWA will get by with very low pop chances. Thursday will be the best chance of meeting critical fire weather conditions, however. Relative humidity values in the teens will push well east, and 20 ft. winds will be moderate from late Thursday morning into the afternoon, meaning breezy to windy ASOS readings, more so with the GFS. Forecast parameters support a few hours of critical fire weather conditions on Thursday, with enhanced to potentially explosive wildfire growth and spread threat. High temperatures will rise well into the 80s on Thursday, well above normal, but the new air mass will keep more extreme values out of the picture. As high pressure moves quickly east, winds will shift back to southeast with some moisture return on Friday. This will help coastal regions, but elevated fire weather conditions will likely still pose a threat inland. The arrival of reinforcing high pressure from the Southern plains on Saturday will bring another front into South Texas Saturday night into Sunday. Model guidance is advertising a chance of showers along a southward scooting front, but more so along the coast, and a non-negligible chance of thunder. The front will race through mid day Sunday with high pressure settling in Sunday night. Overrunning will keep more moisture locked in over the area, with winds returning to southeast, along with return moisture, on Monday. The weather will remain quiet Monday and Tuesday, but a positively tilted mid level trough will set up over the Southwest United States, sending energy over the Mexican mountains as another Plains surface front surges into East and Southeast Texas. MARINE: Now through Tuesday Night: Deepening low pressure across the Plains today will keep the pressure gradient tight along the lower Texas coast through this afternoon and into the early evening hours. A Small Craft Advisory is in effect for the Laguna Madre and all of the Gulf of Mexico waters through 10 PM CDT. Seas on the Gulf will remain moderate to moderately-high, generally 5 to 7 feet through tonight. A very weak frontal boundary will arrives across Deep South Texas into Tuesday morning, weakening the pressure gradient and allowing seas to subside beginning mid- Tuesday morning. Weak northerly winds Tuesday afternoon will quickly become onshore (easterly) again by Tuesday evening, but remain generally light and favorable. Wednesday through Saturday Night...Moderate southeast winds will prevail Tuesday through early Thursday. A cold front will push offshore on Thursday, with a period of moderate to strong north winds building seas. Moderate winds and moderate to high seas will persist Thursday night through Friday in the wake of the front. Small craft advisory conditions will be possible on Thursday and Thursday night or Friday in the wake of the front, especially offshore. Conditions will improve slightly on Saturday, with light to moderate onshore winds and low to moderate wave heights. FIRE WEATHER: Tuesday...A very weak cold front will push through the region on Tuesday morning. Relative humidity values are expected to drop below 30 percent along and west of I-69E and below 15 percent across Zapata, Jim Hogg, and Starr counties during the afternoon on Tuesday. Wind speeds behind the front will remain light out of the north through the day and should help mitigate the spread of fires, if they occur. However, due to the ongoing drought and nearly explosive fuel setup, there remains elevated fire weather concerns, and outdoor burning should be banned or strongly discouraged. Thursday...Thursday will have the best chance of meeting critical fire weather conditions, however. Relative humidity values in the teens will push well east, and northwest 20 ft. winds will be moderate from late Thursday morning into the afternoon, meaning breezy to windy ASOS readings, more so with the GFS. Forecast parameters support a few hours of critical fire weather conditions on Thursday, with enhanced to potentially explosive wildfire growth and spread threat. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 65 83 66 85 / 0 0 0 0 BROWNSVILLE 66 87 68 88 / 0 0 0 0 HARLINGEN 64 90 67 89 / 0 0 0 0 MCALLEN 66 94 67 89 / 0 0 0 0 RIO GRANDE CITY 64 97 65 89 / 0 0 0 0 SOUTH PADRE ISLAND 65 73 67 76 / 0 0 0 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && This product is also available on the web at: HTTP://WEATHER.GOV/RGV 56-Hallman...Aviation
Hazardous Weather Outlook...Updated National Weather Service Brownsville TX 1012 PM CDT Mon Mar 22 2021 TXZ248>257-351-353-231130- Zapata-Jim Hogg-Brooks-Inland Kenedy-Starr- Southern Hidalgo-Inland Willacy-Inland Cameron-Coastal Willacy- Coastal Cameron-Coastal Kenedy-Northern Hidalgo- 1012 PM CDT Mon Mar 22 2021 This Hazardous Weather Outlook is for portions of Deep South Texas. .DAY ONE...Rest of Tonight There is a moderate risk of rip currents at the beaches of South Padre Island and at Boca Chica Beach .DAYS TWO THROUGH SEVEN...Tuesday through Sunday An elevated risk of rip currents is possible at the beaches of South Padre Island and at Boca Chica Beach through the entire period. Elevated to critical fire weather conditions are possible Wednesday and Thursday. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed. GMZ130-132-135-150-155-170-175-231130- Laguna Madre from the Port of Brownsville to the Arroyo Colorado-Laguna Madre from the Arroyo Colorado To 5 NM north of Port Mansfield TX-Laguna Madre from 5 nm north of Port Mansfield to Baffin Bay TX-Coastal waters from Port Mansfield to the Rio Grande out 20 nm-Coastal waters from Baffin Bay to Port Mansfield out 20 nm-Waters from Port Mansfield to the Rio Grande extending from 20 to 60 nm-Waters from Baffin Bay to Port Mansfield extending from 20 to 60 nm- 1012 PM CDT Mon Mar 22 2021 This Hazardous Weather Outlook is for portions of The Gulf of Mexico and The Laguna Madre. .DAY ONE...Rest of Tonight No hazardous weather is expected. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday Small Craft Advisories may be needed Thursday. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed.
The national radar mosaic for the moment the first event began.
9 drought. Local standard time, as filed.
Due to persistent lack of significant rainfall, Exceptional (D4) Drought developed and covered all of Zapata County beginning on March 23rd and continuing through the end of the month.
Due to persistent lack of significant rainfall and dry fronts, Exceptional (D4) Drought developed in extreme northeastern Starr County, continued in western portions. Extreme (D3) Drought continued elsewhere and finally overtook the southeastern portion of the county. Cattle ranchers reported the need for additional water hauling due to the lack of available water supplies.
Due to persistent lack of significant rainfall, Exceptional (D4) Drought developed in southern and eastern portions of Brooks county while Extreme (D3) Drought overtook the northeastern sliver of the county that had been in Severe (D2) conditions.
Due to persistent lack of significant rainfall, Exceptional (D4) Drought developed across the majority of Northern Hidalgo county, with the exception of southwestern portions of the area near McCook. Dryland crops were unable to be planted due to the dry soil, causing a delay in the start of certain crops' growing season, and water hauling increased for cattle ranchers in the area.
Due to persistent lack of significant rainfall, Exceptional (D4) Drought developed across northern portions of Southern Hidalgo County while Extreme (D3) Drought overtook the remainder of the county. The increased D4 area included the area north of Edinburg, including Faysville and Hargill. Dryland crops could not be planted at their usual time due to the lack of soil moisture.
Due to persistent lack of significant rainfall, Exceptional (D4) Drought developed across southwestern portions of Inland Kenedy County. Extreme (D3) Drought also pushed eastward across the remainder of Inland Kenedy.
Due to persistent lack of significant rainfall, Extreme (D3) Drought expanded eastward across the majority of Coastal Kenedy County, with the exception of far southern areas and the barrier island over the southeast portion.
Due to persistent lack of significant rainfall, Exceptional (D4) Drought developed across far western portions of Willacy County. Extreme (D3) Drought also expanded eastward across central and eastern Willacy with a sliver of Severe (D2) Drought across the southeast portion of Inland Willacy County.
Due to persistent lack of significant rainfall, Extreme (D3) Drought expanded eastward across more of western and central Cameron County, to include the Harlingen area and many of the crop field surrounding it. Severe (D2) Drought remained in place across central Cameron County.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Texas in 2021Every state in 2021This day in weather historyWarnings in Texas, March 2021
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 950199, 950200, 950201, 950202, 950203, 950204, 950205, 950206, 950209.