First significant heavy rain and
 flooding event of 2010: January 14-15
Alex Tardy NWS Corpus Christi

                     

Storm Total January 13-15 2010	Oso Creek and Staples at 19.95 feet	Oso Creek and Staples

Radar Loops	Ranifall Reports	6 am to Noon
Satellite Loops	6 pm to Midnight	Noon to 6 pm
Upper Air	Midnight to 6 am	Model Guidance

Local Storm Report

Introduction

A series of short wave troughs affected South Texas during November and December 2009 resulting in above normal precipitation and notably alleviating residual severe drought conditions. Most of these events consisted of stratiform precipitation over a low-level cold air mass. The coldest air mass of the season previously brought arctic temperatures to the region between January 8 to 10th, not felt since the years of 1989 and 1998. However, this cold dome of air was completely mixed out prior to the onset a narrow area of rain on January 13th which allowed surface dew points to rise into the 60s F and layer precipitable water to reach 1.40 inches. The event on 14-15 January 2010 was the strongest in the series of troughs that occurred in an El Nino influenced jet stream pattern and resulted in heavy localized rainfall and significant cloud-to-ground lightning strikes. Widespread 2 to 4 inches of rain occurred across South Texas and 3 to 5 inches across the Coastal Bend. Local amounts up to 6 inches fell along the immediate coast. Soils were nearly saturated from the December rainfall and significant runoff caused sharp rises to creeks and eventually minor flooding to several rivers. In addition, localized rainfall rates of 1 inch per hour produced urban and small stream flooding. (see Local Storm Report below)

Medium range numerical weather prediction (NWP) advertised the potential for a significant rainfall event several days prior to January 15^th. NWP quantitative precipitation forecasts (QPF) generally placed the axis of heavy rain from the waters of the Northwest Gulf to across the entire Coastal Bend. The 1200 and 1800 UTC 13 January NAM runs began to focus the axis of heaviest QPF across the interior coastal plains, eastern portions of the Brush Country and the northern Coastal Bend. GFS model QPF also began a trend of placing the axis across the northern half of the Coastal Bend and northwestward towards San Antonio. Corresponding predictions from the Hydrometeorological Prediction Center (HPC)kept the maximum across Corpus Christi but expanded the area north and westward. The ECMWF model was last to depict the heaviest axis inland from the immediate coast but this model, along with the GFS, was superior for the Coastal Bend. The NAM verified the inland axis of heavy rain better than the other models but had poor run-to-run consistency along the coast where the strong moist convection occurred.The short range ensemble forecast (SREF) runs were similar to the HPC forecasts but depicted lighter amounts.

Radar Loops

KCRP base reflectivity loop starting 2132 UTC 14 January 2010	KCRP base reflectivity loop starting 1206 UTC 15 January 2010

Satellite Loops

GOES water vapor and wind loop starting 1715 UTC January 14 2010	GOES water vapor and wind loop starting 1415 UTC January 15 2010

GOES infrared and NLDN loop starting 2201 UTC 14 January 2010

Upper Air

0000 UTC 15 January	1200 UTC 15 January	0000 UTC 16 January

Rainfall Reports (most of the rain occurred from 0000 UTC 15 to 0000 UTC 16 January)

0000-0600 UTC (6 pm to Midnight CST)

Showers and thunderstorms rapidly developed during Thursday evening of 15 January (UTC) from deep South
Texas and across the Northwest Gulf of America. The heavy rain elements and significant lightning slowly lifted
northward along the southern Coastal Bend producing rainfall rates of 0.50 to 1.50–in per hour. The precipitation
developed in a rapidly destabilizing air mass that responded to strong low to mid-level moisture advection, 
increasing upper-level divergence ahead of a closing off upper-low in Mexico and a vorticity lobe rotating into the
region.  Surface-based instability was marginal (200 J/kg or less) Thursday evening with the greatest values
over the Gulf of America and further south in the warm sector.  However, instability slightly elevated above the
surface was considerable (see Bufkit sounding) across the Coastal Bend and within an area of strong 850-mb
moisture convergence.  Rainfall rates dissipated across the far northern Coastal Bend as thunderstorms
were carried away from the strong dynamic lift and considerable elevated instability.
 

RFC 24 hour QPF January 15	0300 UTC surface plot	KCRP composite at 0336 UTC
0000 UTC 15 January BUFKIT NAM sounding - ECAPE (around 4000 J/kg)	Time series at CRP for Total Precipitation Forecast from Tuesday January 12, 2010.  Note the NWS forecast.	KCRP stotal total precipitation at 0507 UTC 14 January 2010.

 0600-1200 UTC (Midnight to 6 am CST)

During this period strong convective precipitation transitioned slowly to stratiform rainfall as instability decreased
with time and synoptic lift waned slightly.  Initial rainfall rates up to 1 inch per hour occurred between 0600 and 0900
UTC but tapered to below one half inch toward 1200 UTC.  Cloud-to-ground lightning was considerable between
0600 and 0800 UTC across the Northwest Gulf of America, but diminished to isolated strikes after 0900 UTC.  
Moderate surface winds produced frequent wind gusts to 35 mph across the near-shore waters and Coastal
Bend where a strong MSL pressure gradient had developed north of a surface low in deep South Texas. The initial
vort lobe sheared apart in the divergent flow aloft with part of the energy moving into the Gulf of America and another
portion that rotated into south central Texas.  Additional short wave vorticity lobes tracked across the Northwest Gulf
during the 0600-1200 UTC period and strong 850-mb convergence shifted northward over the northern Coastal
Bend.  The axis of heavy rain (rates of half inch per hour) followed this convergence, but also increased across
the Brush Country and Rio Grande Valley from Laredo to Cotulla along I-35.  Satellite imagery depicted a comma
shaped structure to the cold cloud tops (see satellite loops above).
 

850 mb moisture transport at 1200 UTC	Deep moisture convergence at 1200 UTC	Storm Total Precipitation at 1244 UTC

1200-1800 UTC (6 am to Noon CST)

Dry air and subsidence entered the southern Coastal Bend as a main vorticity center moved directly over this
region and consolidated with prior energy.  This produced a dry slot as depicted in radar reflectivity loops which
slowly expanded northward into the northern Coastal Bend towards 1800 UTC.  The axis of 850-mb convergence
pivoted and organized heavier rainfall persisted across the Brush Country and Interior Coastal Plain, and expanded
within moderate surface convergence from Baffin Bay to Alice by 1800 UTC.  Rainfall rates of a half inch per hour
over the northern Coastal Bend tapered off during this period but continued across the Brush Country.  Rainfall
rates of around 1 inch per hour caused flooding near Kingsville.  Rainfall persisted in the Rio Grande Valley but rates
tapered off in an area of lighter wrap-around precipitation.
 

HPC 1200 UTC 14 January total QPF	HPC day 1 QPF January 15

1200 UTC 15 January analysis

SBCAPE and CIN	925 mb height, temperature and wind	700 mb height, temperature and wind
500 mb height, temperature, and wind	300 mb wind and divergence	Surface moisture convergence

KCRP 2-day storm total at 1244 UTC 15 January	0600 UTC NCEP-ARW model reflectivity

1800-0000 UTC (Noon to 6 pm CST)

The axis of heavy rain over the Brush Country persisted, intensified and further expanded southward towards Kingsville
and Baffin Bay, while rainfall also continued over the Victoria Crossroads but mostly ended along the Coastal Bend
in the dry slot and subsidence over the northern Coastal Bend (see loop).  Upper-level divergence also depicted
its axis inland and northward.  The increased rainfall rates along a northwest to southeast oriented axis west of
I-37 were similar to NAM model run placement, and increased to a narrow region of one half to 1 inch per hour
(see radar loop).  Rainfall rapidly dissipated at 0000 UTC 16 January as much drier and colder air filtered across
the region and the low to mid-level low shifted over the Gulf of America.

1900 UTC 15 January

850 and 250 mb cross-over wind	SBCAPE and CIN	Surface plot over South Texas
850 mb height, wind and temperature	500 mb height, wind and temperature	300 mb wind and divergence

 0000 UTC 16 January

NAM 0000 UTC 16 January 4-panel analysis

MODEL guidance

1200 UTC 11 January ECMWF and GFS	1200 ECMWF, 1500 SREF, 1800 UTC GFS/NAM 13 January model runs
0000 UTC 14 January GFS total QPF	0000 UTC 14 January NAM total QPF	1200 UTC 14 January GFS total QPF
1200 UTC 14 January NAM total QPF	2100 SREF and 1200 UTC 14 January ECMWF	0000 UTC 15 January model runs

LSR (Local Storm Report)

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
315 PM CST FRI JAN 15 2010

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0249 PM     FLOOD            4 ESE ORANGE GROVE      27.93N 97.88W
01/15/2010                   NUECES             TX   DEPT OF HIGHWAYS

            FM 70 IS CLOSED AT FM 624 DUE TO FLOODING.

0245 PM     FLOOD            8 SSW PORT LAVACA       28.50N 96.65W
01/15/2010                   CALHOUN            TX   EMERGENCY MNGR

            HWY 238 CLOSED DUE TO HIGH WATER OVER A BRIDGE CROSSING.

0215 PM     FLOOD            5 SSW SKIDMORE          28.16N 97.72W
01/15/2010                   BEE                TX   DEPT OF HIGHWAYS

            FM 796 CLOSED AT CR533 DUE TO FLOODING.

0208 PM     FLOOD            7 ESE MATHIS            28.06N 97.72W
01/15/2010                   SAN PATRICIO       TX   DEPT OF HIGHWAYS

            SH 188 CLOSED FROM IH 37 TO FM 796 DUE TO LOW WATER
            CROSSINGS FLOODED.

1254 PM     FLOOD            1 SE ROBSTOWN           27.79N 97.65W
01/15/2010                   NUECES             TX   DEPT OF HIGHWAYS

            NORTH AND SOUTHBOUND FEEDER ROADS ON U.S. 77 CLOSED
            BETWEEN CR44 AND TERRY SHEMISE BLVD DUE TO HIGH WATER.

1150 AM     FLOOD            BISHOP                  27.58N 97.80W
01/15/2010                   NUECES             TX   EMERGENCY MNGR

            SEVERAL ROADS IN THE CITY WERE BEING CLOSED DUE TO HIGH
            WATER.

1134 AM     FLOOD            4 S ALICE               27.70N 98.06W
01/15/2010                   JIM WELLS          TX   DEPT OF HIGHWAYS

            WATER REPORTED OVER FM 1930 BETWEEN U.S. 281 AND FM 1352.
            ROADWAY IS STILL PASSABLE.

1049 AM     FLOOD            3 SSE WOODSBORO         28.19N 97.31W
01/15/2010                   REFUGIO            TX   DEPT OF HIGHWAYS

            FM 629 IS CLOSED FROM FM 3037 AND FM 136 DUE TO WATER
            OVER THE ROAD.

1017 AM     FLOOD            8 WNW SKIDMORE          28.29N 97.81W
01/15/2010                   BEE                TX   DEPT OF HIGHWAYS

            WATER OVER FM 1349 FROM US 59 TO FM 797.

1013 AM     FLOOD            3 NW TYNAN              28.18N 97.77W
01/15/2010                   BEE                TX   DEPT OF HIGHWAYS

            WATER OVER ROAD ON FM 796 BETWEEN FM 888 AND SH 359.

0930 AM     FLOOD            5 NNE ARANSAS PASS      27.97N 97.12W
01/15/2010                   ARANSAS            TX   DEPT OF HIGHWAYS

            WATER OVER FM 1069 AT VARIOUS LOCATIONS BETWEEN 1069 AND
            SH 188.

0755 AM     FLOOD            2 W CORPUS CHRISTI      27.77N 97.53W
01/15/2010                   NUECES             TX   DEPT OF HIGHWAYS

            WATER OVER ROAD ON FM 2292 BETWEEN MCGLOIN ST. AND FM
            665.

0753 AM     FLOOD            5 NNW DRISCOLL          27.74N 97.79W
01/15/2010                   NUECES             TX   DEPT OF HIGHWAYS

            WATER OF ROAD ON FM 2826 BETWEEN CR85 AND CR87.

0750 AM     FLOOD            4 S CORPUS CHRISTI      27.71N 97.50W
01/15/2010                   NUECES             TX   DEPT OF HIGHWAYS

            WATER OVER ROADWAY ON FM 763 BETWEEN FM 665 AND FM 0043.

1245 AM     FLOOD            4 SE CORPUS CHRISTI     27.72N 97.46W
01/15/2010                   NUECES             TX   DEPT OF HIGHWAYS

            WATER OVER SH 357 JUST WEST OF THE LA JOLLA CREEK BRIDGE.


1241 AM     FLOOD            PORT ARANSAS            27.83N 97.08W
01/15/2010                   NUECES             TX   DEPT OF HIGHWAYS

            WATER REPORTED OVER SH 361 AT VARIOUS LOCATIONS INSIDE
            PORT ARANSAS CITY LIMITS.

1237 AM     FLOOD            4 W ROBSTOWN            27.80N 97.72W
01/15/2010                   NUECES             TX   DEPT OF HIGHWAYS

            WATER OVER ROAD ON SH 44 FROM BUSINESS 44 TO FM 1889.

1236 AM     FLOOD            ROCKPORT                28.04N 97.05W
01/15/2010                   ARANSAS            TX   DEPT OF HIGHWAYS

            WATER OVER FM 1781 NEAR FM 1069.

1235 AM     FLOOD            5 NW CORPUS CHRISTI     27.83N 97.55W
01/15/2010                   NUECES             TX   DEPT OF HIGHWAYS

            WATER OVER FM 2292 AND LEOPARD ST. INTERSECTION.

1226 AM     FLOOD            2 NNE ARANSAS PASS      27.92N 97.14W
01/15/2010                   ARANSAS            TX   DEPT OF HIGHWAYS

            WATER OVER ROAD SOUTHBOUND LANE OF BUSINESS 35L NEAR
            STAPP ST.

1210 AM     FLOOD            1 N CHAPMAN RANCH       27.59N 97.45W
01/15/2010                   NUECES             TX   DEPT OF HIGHWAYS

            SH 286 CLOSED BETWEEN FM 2444 AND FM 70 DUE TO WATER OVER
            THE ROAD...PARTICULARLY BETWEEN CR12 AND CR14. FM 70 FM
            US 77 AND SH 286 IS ALSO CLOSED DUE TO THIS FLOODING

1209 AM     FLOOD            1 S WOODSBORO           28.22N 97.32W
01/15/2010                   REFUGIO            TX   DEPT OF HIGHWAYS

            LOW WATER CROSSINGS ARE FLOODED WITH WATER OVER THE
            ROADWAY ON FM 1360


Alex Tardy WFO Corpus Christi