Drought, Busted! Early rains, late July 2008 break precipitation records in the Lower RGV

July 2008: Early Soaking, Dolly Kill Drought

Immense amounts of rain bookended the month of July, with torrential bursts from Hurricane Dolly not only ending the drought, but shattering some all time monthly records by several inches across much of the Lower Rio Grande Valley. The highest totals were found in extreme eastern Hidalgo, southwestern Willacy, and northern and central Cameron County. Unfortunately, a number of surface reporting stations, including airports, cooperative observers, and Community Collaborative Rain, Hail, and Snow (CoCoRaHS) network observers either did not report, or were unable to report, rainfall due to power outages in the path of Dolly's strongest winds across northern Cameron into southern Willacy County.

A prolonged period of clouds and rain during the first full week of the month, followed by Dolly, and later, resulting slow evaporation of surface moisture which followed the storm, held monthly temperatures substantially below average for the middle of summer. Across the Lower Rio Grande Valley, temperatures were generally 1 to 2 degrees below the 30 year average, placing Brownsville, Harlingen, and McAllen within the top 20 coolest July's since records began (1878 in Brownsville, 1911 in Harlingen, and 1941 in McAllen). Harlingen (8th coolest) and McAllen (15th coolest) data are incomplete due to power loss after Dolly.

Here are a couple of more interesting facts from Dolly's rains (6.68 inches) in Brownsville on July 23^rd:

Was the greatest single day total of any July;
Was the 11^th highest 24 hour total of any calendar day since 1878;
Was greater than the total rainfall for any July except in 1978 and 1919!

Below is a table of rain totals for July. Many locations, both official and unofficial, reported no data, insufficient data, or incomplete data. Locations such as Port Isabel/Cameron County Airport were knocked off line just as the heaviest rains were arriving during Dolly; available data was deemed too unrepresentative to include in this report. The table will be updated if and when additional representative rainfall information trickle in.

**Rainfall Data, July 2008, from Airports, Cooperative Observers, and CoCoRAHS.**
Many sites missing data or incomplete due to power outages or wind from Dolly.
CITY/TOWN	COUNTY	RAINFALL (INCHES)	CITY/TOWN	COUNTY	RAINFALL (INCHES)
5 SSE San Benito	Cameron	17.64	3.5 N Brownsville	Cameron	12.64
Laguna Atascosa	Cameron	17.13	11.1 N La Joya	Hidalgo	12.61
Harlingen	Cameron	15.32i	4.5 NNW Brownsville	Cameron	12.48
Rancho Viejo	Cameron	14.80	Brownsville 6.4 SE	Cameron	12.31
1.5 NNE Alamo	Hidalgo	14.77	Cameron Park 3.9 W	Cameron	12.12
2.6 NE McAllen	Hidalgo	14.48	Weslaco/Mid Valley	Hidalgo	11.95i
2.6 NW McAllen	Hidalgo	14.41	Mercedes	Hidalgo	11.73
2.2 NW Palm Valley	Cameron	14.21i	McCook	Hidalgo	10.11i
2.6 SE Harlingen	Cameron	14.17	Falcon Dam	Zapata	9.82i
Los Fresnos	Cameron	13.84	Escobas	Zapata	9.75
San Manuel	Hidalgo	13.35	Hebbronville	Jim Hogg	9.57
4.1 E Brownsville	Cameron	13.32	Falcon Lake	Starr/Zapata	8.78
Brownsville Intl Arpt	Cameron	13.24	Armstrong	Kenedy	8.34
Harlingen Valley Arpt	Cameron	13.22i	McAllen	Hidalgo	8.06i
Linn San Manuel	Hidalgo	13.11	7 E Sarita	Kenedy	7.83
Santa Ana NWR	Hidalgo	13.10	Falfurrias/Brooks Apt	Brooks	6.13i
1.9 NE Mission	Hidalgo	12.75	Rio Grande City	Starr	5.46i

*Data Estimated.
i = Data Incomplete.
.