RGV Event total rainfall, December 10th through 12th, 2011 (click to enlarge)
Observed rainfall, from 12 AM (Midnight) December 10th through 11 AM December 12th, 2011.
Worth the Wait!
Steady Rains Drench the Valley December 10–11


First Areawide Rain since January 2011; First Valleywide Rain since Late June

Summary
An upper level disturbance traveling the southern branch of a split jet stream induced significant lifting of moisture into the Rio Grande Valley to the west of a trough of low pressure hovering near the Lower Texas coast. Rainfall between 2 and 3 inches soaked McAllen, Mission, Pharr, and points west into Starr County along the Rio Grande mainly on December 10th, followed by additional light rain and drizzle on the 11th. For the Mid and Upper Valley, the weekend was rainy and chilly, as temperatures struggled to get into the 50s along with an occasionally stiff north wind. For the Lower Valley, slightly warmer temperatures and less lift kept rain totals closer to an inch or less, with periods of gusty winds in excess of 30 mph from the east. Other impacts included tidal overwash from the blustery east winds along the coast at high tide on the 11th, high surf above head height into early December 11th, and seas over 11 feet in the open Gulf waters.

Though more rains are needed to significantly alleviate the drought, the combination of a slow, soaking rain followed by two days of persistent clouds, cool temperatures, high humidity, and light winds allowed for much of the water to soak into the soil rather than evaporate quickly. Warm, humid conditions that followed help bring at least temporary green back to a number of locations, a nice change from the tan and dusty landscape since mid summer.

The following summary lists observed rainfall from airport stations, cooperative observers, and weather enthusiasts. Thanks to everyone who provided detailed measurements to help fill in gaps that were not readily apparent on radar, which underestimated storm total rainfall significantly in areas where totals were greatest.


PUBLIC INFORMATION STATEMENT...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1047 AM CST MON DEC 12 2011

...FIRST WIDESPREAD RAINS IN NEARLY A YEAR SOAK THE VALLEY...

***FINAL REPORT***

A SERIES OF MID AND UPPER LEVEL DISTURBANCES COMBINED WITH A LOW
PRESSURE TROUGH ALONG THE LOWER TEXAS COAST TO LIFT MOISTURE INTO
SIGNIFICANT RAINS FROM THE RIO GRANDE VALLEY TO THE RANCHLANDS OF
ZAPATA...JIM HOGG...BROOKS...AND KENEDY COUNTY. EVENT TOTALS AS OF
11 AM DECEMBER 12TH RANGED FROM AROUND ONE HALF INCH NEAR THE CAMERON
COUNTY COAST TO BEWTEEN 2 AND 3 INCHES FROM HIDALGO TO SOUTHERN ZAPATA
COUNTY.

FOR LOCATIONS IN WESTERN HIDALGO AND EASTERN STARR COUNTY...THE
TWO DAY RAINFALL DECEMBER 10TH AND 11TH WAS NEARLY 50 PERCENT OF THE TOTAL
RAINFALL OBSERVED DURING THE PRIOR FOURTEEN MONTHS!

THE FOLLOWING IS A PRELIMINARY SUMMARY OF RAINFALL AS OF 11 AM CST
DECEMBER 12TH.


CITY/TOWN COUNTY RAIN OBS TYPE UPDATED

FALCON LAKE STARR 3.20 RAWS 8 AM DEC 12
RIO GRANDE CITY** STARR 2.86 COOP 7 AM DEC 12
MISSION 1.9 ENE HIDALGO 2.36 COCORAHS 9 AM DEC 12
MCALLEN 2.4 NE HIDALGO 2.52 COCORAHS 8 AM DEC 12
SANTA ANA/LOWER RGV NWR HIDALGO 2.34 RAWS 8 AM DEC 12
LA JOYA HIDALGO 2.25 COOP 6 AM DEC 12
PHARR 5.1 N HIDALGO 2.01 COCORAHS 10 AM DEC 12
LAREDO/INTL ARPT WEBB 1.99 ASOS 8 AM DEC 12
MCALLEN/MILLER INTL ARPT HIDALGO 1.94 ASOS 8 AM DEC 12
MCALLEN 3 SW* HIDALGO 1.93 CWOP
MISSION 1.5 E* HIDALGO 1.92 CWOP
MCALLEN 3 N* HIDALGO 1.90 CWOP
ZAPATA/ZAPATA CO ARPT ZAPATA 1.83 AWOS 8 AM DEC 12
ALAMO 1.5 NNE HIDALGO 1.87 COCORAHS 8 AM DEC 12
EDINBURG 1.1 WSW HIDALGO 1.83 COCORAHS 8 AM DEC 12
FALCON DAM STARR 1.73 COOP 7 AM DEC 12
MISSION 2 E* HIDALGO 1.73 CWOP
EDINBURG HIDALGO 1.60 COOP 7 AM DEC 12
RINCON STARR 1.60 COOP 11 AM DEC 12
ESCOBAS ZAPATA 1.58 COOP 7 AM DEC 12
HEBBRONVILLE JIM HOGG 1.39 COOP
LINN/SAN MANUEL NWR HIDALGO 1.26 RAWS 8 AM DEC 12
RAYMONDVILLE WILLACY 1.22 COOP
PORT ISABEL CAMERON 1.20 COOP ADDED 8 AM DEC 12
HEBBRONVILLE/JIM HOGG CO JIM HOGG 1.13 AWOS 8 AM DEC 12
WESLACO 3.5 N* HIDALGO 1.12 CWOP
ARMSTRONG KENEDY 1.11 COOP 7 AM DEC 12
MC COOK HIDALGO 1.05 COOP ADDED 8 AM DEC 12
WESLACO/MID VALLEY ARPT HIDALGO 1.02 AWOS 8 AM DEC 12
SAN MANUEL 5 E HIDALGO 1.02 CRN
MERCEDES 6 SSE HIDALGO 1.01 COOP 7 AM DEC 12
LOS FRESNOS 0.3 NE CAMERON 1.00 COCORAHS 8 AM DEC 12
RANCHO VIEJO CAMERON 0.98 COCORAHS 1115 AM DEC 11
HARLINGEN CAMERON 0.98 COOP 7 AM DEC 12
RANCHO VIEJO 3 SE CAMERON 0.98 COCORAHS ADDED 8 AM DEC 12
RAYMONDVILLE 5.8 E WILLACY 0.96 COCORAHS ADDED 9 AM DEC 12
BROWNSVILLE 5.0 NW CAMERON 0.90 COCORAHS 8 AM DEC 12
HARLINGEN 4.7 WSW CAMERON 0.88 COCORAHS 1115 AM DEC 11
HARLINGEN 4.3 WSW CAMERON 0.84 COCORAHS ADDED 8 AM DEC 12
FALFURRIAS BROOKS 0.82 COOP 7 AM DEC 12
KINGSVILLE/NAS KLEBERG 0.81 ASOS 8 AM DEC 12
LOS FRESNOS 1 S CAMERON 0.80 NWS EMP ADDED 8 AM DEC 12
EDINBURG/INTL ARPT*** HIDALGO 0.79 AWOS 8 AM DEC 12
FALFURRIAS 0.5 WNW BROOKS 0.79 COCORAHS 8 AM DEC 12
BROWNSVILLE 4.1 E CAMERON 0.78 COCORAHS 1115 AM DEC 11
BROWNSVILLE 6.4 SSE CAMERON 0.77 COCORAHS 8 AM DEC 12
PORT MANSFIELD WILLACY 0.76 COOP
HARLINGEN/VALLEY INTL ARPT CAMERON 0.73 ASOS
BROWNSVILLE 4.4 NE CAMERON 0.73 COCORAHS 1115 AM DEC 11
HARLINGEN 2.6 ESE CAMERON 0.72 COCORAHS 8 AM DEC 12
BROWNSVILLE 2.2 W CAMERON 0.71 COCORAHS 8 AM DEC 12
FALFURRIAS 8.9 SSW BROOKS 0.71 COCORAHS 8 AM DEC 12
SAN BENITO 5 SSE CAMERON 0.69 COCORAHS ADDED 8 AM DEC 12
SARITA KENEDY 0.64 COOP
BROWNSVILLE/SPI ARPT CAMERON 0.60 ASOS 1115 AM DEC 11
BROWNSVILLE 0.1 SSE CAMERON 0.59 COCORAHS 8 AM DEC 12
FALFURRIAS/BROOKS CO ARPT BROOKS 0.56 AWOS 8 AM DEC 12
SOUTH PADRE ISLAND CAMERON 0.48 COOP
BAYVIEW/CAMERON CO ARPT CAMERON 0.27 ASOS
LAGUNA ATASCOSA NWR CAMERON 0.20 RAWS


OBS TYPE LEGEND:
ASOS - AUTOMATED SURFACE OBSERVING SYSTEM (NWS/DOD)
AWOS - AUTOMATED WEATHER OBSERVING SYSTEM (FAA/OTHERS)
COOP - COOPERATIVE OBSERVER (NWS)
CWOP - CITIZENS WEATHER OBSERVING PROGRAM
RAWS - REMOTE AUTOMATED WEATHER SYSTEM
CRN - CLIMATE REFERENCE NETWORK
COCORAHS - COMMUNITY COLLABORATIVE RAIN HAIL AND SNOW NETWORK

*ESTIMATED BASED ON 24 HOUR LISTED TOTALS
**NO INFORMATION FOR EARLY MORNING DECEMBER 10TH.
***MEASUREMENT MAY NOT BE REPRESENTATIVE OF NEARBY LOCATIONS

 


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