Northerly flow on the back side of a departing upper level disturbance, combined with hot, humid, unstable air along the Rio Grande to promote several areas of strong to severe thunderstorms. More than an hour of heavy rainfall produced urban flooding in La Joya between 330 and 4 pm, with high water continuing through 430 pm.  The large storm cell surged from northeast Cameron County through Bayview, then on into Brownsville between 4 and 445 pm. Additional cells formed on outflows and continued the heavy rains west of Harlingen through around 6 pm, with between 3.25 and 4.7 inches having fallen. Scattered reports of large hail, urban flooding, frequent cloud to ground lightning strikes, and pockets of wind damage to tree limbs and power lines was common.
The last surge of intense storms occurred just before sunset, as remnant boundaries fired in a small area of southern Starr County, around and just north of Rio Grande City. An intense but brief updraft surged into the storm and resulted in reports of quarter sized hail or larger.

Thunderstorm Wind in CAMERON, TEXAS
From 28-MAY-14 15:10:00 to 28-MAY-14 15:10:00 (CST-6)
Location: PORT ISABEL ARPT
Magnitude: 58.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The ASOS at the Port Isabel Airport in Bayview reported a 58 knot wind gust.

Heavy Rain in STARR, TEXAS
From 28-MAY-14 17:20:00 to 28-MAY-14 19:15:00 (CST-6)
Location: OLNOS
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Heavy rain fell for almost two hours across Rio Grande City during the early evening hours of May 28th. The Rio Grande City Fire Department reported one foot of water on the road near FM 755 and Embassy Street. Official rainfall reports from the COOP observer in Rio Grande City showed 2.6 inches of rain fall, with an unofficial report of 3.74 inches near FM 755.

Hail in CAMERON, TEXAS
From 28-MAY-14 15:08:00 to 28-MAY-14 15:08:00 (CST-6)
Location: PORT ISABEL
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported penny sized hail in Port Isabel.

Thunderstorm Wind in CAMERON, TEXAS
From 28-MAY-14 15:35:00 to 28-MAY-14 15:37:00 (CST-6)
Location: BROWNSVILLE
Magnitude: 52.00 EG
Crop damage: 0.00K
Reported by: NWS Employee

NWS employee reported several one to two foot diameter trees snapped with estimated 60 mph wind gusts.

Hail in STARR, TEXAS
From 28-MAY-14 18:25:00 to 28-MAY-14 18:30:00 (CST-6)
Location: RIO GRANDE CITY
Magnitude: 1.75 
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported quarter size hail and provided a video that suggested hail up to half dollar size fell.

Thunderstorm Wind in STARR, TEXAS
From 28-MAY-14 18:25:00 to 28-MAY-14 18:30:00 (CST-6)
Location: RIO GRANDE CITY
Magnitude: 52.00 EG
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported wind gusts of 50 to 60 mph in Rio Grande City.

Heavy Rain in HIDALGO, TEXAS
From 28-MAY-14 14:00:00 to 28-MAY-14 15:00:00 (CST-6)
Location: LA JOYA
Crop damage: 0.00K
Reported by: Public

Approximately an hour of heavy rainfall, with rainfall totals approaching 3 inches, produced urban flooding in La Joya between 330 and 4 pm CDT.  Reports of one to two feet of standing water in roadways were received.

Lightning in CAMERON, TEXAS
From 28-MAY-14 15:15:00 to 28-MAY-14 15:21:00 (CST-6)
Location: LAGUNA VISTA
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Local law enforcement officials reported two house fires started by lightning strikes in the town of Laguna Vista.

Heavy Rain in CAMERON, TEXAS
From 28-MAY-14 15:35:00 to 28-MAY-14 16:15:00 (CST-6)
Location: BROWNSVILLE
Crop damage: 0.00K
Reported by: Emergency Manager

Almost an hour of heavy rain fell across Brownsville during the late afternoon hours of May 28th. CoCoRaHS observers reported between 2 and a little over 2.5 inches of rain across western Brownsville.  The downpours resulted in streets in downtown Brownsville being covered in as much 18 inches of water, especially near Palm Boulevard, where trash cans were reported floating along the roadway.