A thunderstorm, forming along boundaries from earlier activity during the afternoon on May 9th and aided by proximity to a stationary surface front and another wave of energy ahead of an upper level disturbance, quickly became severe northeast of Edinburg. Between 9 and 945 PM, winds increased, rain poured down, and hail developed as the storm formed and began moving east.
At approximately 930 PM, a microburst and large hail struck a colonia in Doolittle, damaging nearly every home (most were of poor construction) and rolling two unanchored trailers. The storm would continue east-southeast through eastern Hidalgo county and on into western Willacy County, generally along and north of state highway 107 in Hidalgo County, and along and north of the Cameron/Willacy County line. Additional small to medium sized hail fell from Edcouch/Elsa (Hidalgo County) eastward through Sebastian to just south of Raymondville (Willacy County) before the storm weakened just before 11 PM CDT.
Additional cells forming along boundaries from the initial storm north of Edinburg pushed northeast into the King Ranch, eventually dropping large hail along U.S. Highway 77.

Hail in HIDALGO, TEXAS
From 09-MAY-12 20:55:00 to 09-MAY-12 20:57:00 (CST-6)
Location: LA BLANCA
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported penny size hail 10 mile NE of Edinburg near Elsa at the intersection of FM2812 and Val Verde Road.

Hail in KENEDY, TEXAS
From 09-MAY-12 21:30:00 to 09-MAY-12 21:33:00 (CST-6)
Location: TURCOTTE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Other Federal Agency

Border patrol checkpoint 15 miles south of Sarita reported predominantly nickel size hail with embedded quarter size hail.

Hail in WILLACY, TEXAS
From 09-MAY-12 21:25:00 to 09-MAY-12 21:35:00 (CST-6)
Location: SEBASTIAN
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

After an initial report of baseball to softball sized hail in Sebastian, visual evidence from an NWS storm survey indicated no discernible hail impact in Sebastian. Estimated size was penny sized based on conversations with affected residents. the hail lasted up to 10 minutes.

Hail in WILLACY, TEXAS
From 09-MAY-12 21:40:00 to 09-MAY-12 21:45:00 (CST-6)
Location: LYFORD
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Willacy County emergency manager reported golfball size hail 2 miles south of Raymondville.

Hail in HIDALGO, TEXAS
From 09-MAY-12 20:25:00 to 09-MAY-12 20:30:00 (CST-6)
Location: FAYSVILLE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Several residents of a colonia in Doolittle reported at least five minutes of hail, up to the size of quarters, with a severe thunderstorm that also produced a damaging microburst in the area.

Thunderstorm Wind in HIDALGO, TEXAS
From 09-MAY-12 20:25:00 to 09-MAY-12 20:30:00 (CST-6)
Location: FAYSVILLE
Magnitude: 56.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Between 9 and 945 PM, winds increased, rain poured down, and hail developed as the storm formed and began moving east. At approximately 930 PM, a microburst and large hail struck a colonia in Doolittle, damaging nearly every home (most were of poor construction) and rolling two unanchored trailers. One resident���s ceiling caved in from the combination of hail, estimated to be quarter sized, torrential rains, and driving 60 to 65 mph winds. Another tin roof was completely blown from a mobile home. A man was inside one of the trailers when it rolled; fortunately, he was not injured. Nearby, several large limbs were broken from mesquite trees, and one tree was partially uprooted. Shed damage was also noted at the Diamond B Ranch, just north of the colonia, which occurred moments before the downburst wrecked the colonia.