Back-to-back powerful Pacific storm systems to impact the Pacific Northwest and northern California through the end of this week with heavy rain, flooding, strong winds, and higher elevation mountain snow. A strong, long-duration atmospheric river will accompany the Pacific storms, bringing excessive rainfall and flash flooding to southwest Oregon and northwest California through the week. Read More >
A bi-modal storm system impacted Oklahoma and north Texas from Tuesday April 9th through Wednesday April 10th. Several days of moist southerly flow combined with mainly clear skies lead to ample instability, but a strong capping inversion kept storms from developing much of the day. By mid to late afternoon, an unusually strong, but shallow cold front had moved into central Oklahoma. Temperatures across the front ranged from below freezing over northern and western Oklahoma, to the low 80s over southern and eastern portions of Oklahoma. Despite lift along the front, the capping inversion kept storms from forming. It wasn't until late afternoon and early evening that storms finally developed behind the front in the cold post-frontal air mass. A few isolated storms also formed near the cold front/dryline intersection where convergence was enhanced. With cold temperatures aloft, and very steep lapse rates, large hail was abundant, and several reports of hail exceeding two inches in diameter were received, mainly over portions of western north Texas. A lightning strike from one of the supercells over Archer county Texas near Olney, TX resulted in a tank explosion. Fortunately no injuries were reported.
As the front continued to surge southward, freezing to near freezing temperatures overspread much of western Oklahoma and western north Texas. A potent upper level wave allowed for widespread moderate to heavy rain showers and thunderstorms where surface temperatures were below freezing, generating freezing rain. While not unheard of, freezing rain during April is exceedingly rare in Oklahoma and north Texas. Freezing rain continued into the early afternoon as precipitation finally ended from west to east. Much of western Oklahoma and far western north Texas saw ice accumulations. Fortunately, ground temperatures were relatively warm thanks to several days of temperatures in the 70s and 80s, preventing ice from sticking to roadways. However, ice accumulations of a quarter to a half inch occurred on trees and power lines, resulting in sporadic power outages. this was particularly the case over west central and central Oklahoma. Substantial tree damage also occurred, especially to soft wood trees with increasing leaf canopies due to the recent warmer temperatures.
Freezing rain events are not all that uncommon across Oklahoma and north Texas, especially during the late Winter and early Spring months. However, the late nature of this event does make it stand out. Looking at past events, the latest such freezing rain event that resulted in ice accumulation in Oklahoma City occurred back on April 17-18 of 1953. Northwest Oklahoma, which tends to have a greater frequency of winter weather events, had it's latest freezing rain event in late April 1994 at Gage. While cold fronts of this magnitude certainly bring below average temperatures for a brief time, they cannot accurately foretell what the summer may be like. For instance, the summer of 1953, the year in which Oklahoma City's latest icing occurred, was one of the hottest summers across the Central and Southern Plains on record. What we can say for sure, is that this is an unusually late freezing rain occurrence, and that it likely won't happen again this year. Heading into late April and early May, we are sure to warm up,
PRELIMINARY LOCAL STORM REPORT...SUMMARY NATIONAL WEATHER SERVICE NORMAN OK 245 PM CDT WED APR 10 2013 ..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON... ..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE.... ..REMARKS.. 0630 AM FREEZING RAIN OMEGA 35.87N 98.20W 04/10/2013 E0.50 INCH KINGFISHER OK TRAINED SPOTTER DOWNED TREES AND SPORADIC POWER OUTAGES ALSO REPORTED. 0630 AM FREEZING RAIN VANCE AIR FORCE BASE 36.34N 97.90W 04/10/2013 E0.25 INCH GARFIELD OK OTHER FEDERAL 0700 AM FREEZING RAIN CORDELL 35.30N 98.98W 04/10/2013 E0.50 INCH WASHITA OK LAW ENFORCEMENT 1/4 TO 1/2 INCH OF ICE ON TREES, POWER LINES, AND VEHICLES. 0845 AM FREEZING RAIN BINGER 35.31N 98.34W 04/10/2013 E0.30 INCH CADDO OK LAW ENFORCEMENT 1/4 TO 1/3 INCH OF ICE ON TREES, POWER LINES, AND VEHICLES. 0845 AM FREEZING RAIN HINTON 35.47N 98.36W 04/10/2013 E0.25 INCH CADDO OK LAW ENFORCEMENT GLAZE TO A QUARTER INCH REPORTED ON ELEVATED SURFACES. 0848 AM FREEZING RAIN EL RENO 35.53N 97.96W 04/10/2013 E0.12 INCH CANADIAN OK LAW ENFORCEMENT 0848 AM FREEZING RAIN YUKON 35.50N 97.74W 04/10/2013 E0.25 INCH CANADIAN OK UTILITY COMPANY 1/8 TO 1/4 INCH OF ICE ON TREES, SPORADIC POWER OUTAGES. 0920 AM FREEZING RAIN LAWTON 34.60N 98.42W 04/10/2013 E0.25 INCH COMANCHE OK FIRE DEPT/RESCUE 1/4 INCH OR LESS OF ICE ON TREES AND CARS. 0920 AM SNOW FREEDOM 36.77N 99.11W 04/10/2013 E0.5 INCH WOODS OK CO-OP OBSERVER MIXED PRECIPITATION REPORTED INCLUDING SLEET, HAIL, AND SNOW. 0920 AM FREEZING RAIN WAYNOKA 36.58N 98.88W 04/10/2013 E0.25 INCH WOODS OK CO-OP OBSERVER 0930 AM FREEZING RAIN CHEROKEE 36.75N 98.35W 04/10/2013 E0.25 INCH ALFALFA OK LAW ENFORCEMENT 0932 AM FREEZING RAIN FREDERICK 34.39N 99.01W 04/10/2013 E0.25 INCH TILLMAN OK FIRE DEPT/RESCUE SPORADIC POWER OUTAGES FROM DOWNED TREES. 0933 AM FREEZING RAIN 1 SSE HELENA 36.53N 98.26W 04/10/2013 E0.25 INCH ALFALFA OK CO-OP OBSERVER 0935 AM FREEZING RAIN JEFFERSON 36.72N 97.79W 04/10/2013 E0.15 INCH GRANT OK CO-OP OBSERVER 0935 AM FREEZING RAIN GREAT SALT PLAINS LAKE 36.74N 98.20W 04/10/2013 E0.15 INCH ALFALFA OK CO-OP OBSERVER 0942 AM FREEZING RAIN ALTUS 34.64N 99.33W 04/10/2013 E0.25 INCH JACKSON OK LAW ENFORCEMENT 0945 AM FREEZING RAIN WATONGA 35.85N 98.41W 04/10/2013 E0.25 INCH BLAINE OK CO-OP OBSERVER 0945 AM FREEZING RAIN LAMONT 36.69N 97.56W 04/10/2013 E0.15 INCH GRANT OK CO-OP OBSERVER 1/8 TO 1/16 OF ICE ACCUMULATION REPORTED. 0945 AM FREEZING RAIN 5 NE NEWKIRK 36.93N 96.99W 04/10/2013 E0.05 INCH KAY OK CO-OP OBSERVER GLAZE OF ICE ON TREES AND CARS. 0948 AM FREEZING RAIN ELDORADO 34.47N 99.65W 04/10/2013 E0.25 INCH JACKSON OK FIRE DEPT/RESCUE 0951 AM FREEZING RAIN ANADARKO 35.07N 98.24W 04/10/2013 E0.05 INCH CADDO OK CO-OP OBSERVER GLAZE OF ICE ON TREES AND CARS. 0951 AM FREEZING RAIN FAIRVIEW 36.27N 98.48W 04/10/2013 E0.25 INCH MAJOR OK LAW ENFORCEMENT 0951 AM FREEZING RAIN MANGUM 34.88N 99.50W 04/10/2013 E0.12 INCH GREER OK FIRE DEPT/RESCUE 0951 AM FREEZING RAIN ERICK 35.21N 99.87W 04/10/2013 E0.25 INCH BECKHAM OK CO-OP OBSERVER 0955 AM FREEZING RAIN 1 SW WALTERS 34.35N 98.32W 04/10/2013 E0.10 INCH COTTON OK PUBLIC 0958 AM FREEZING RAIN HOLLIS 34.69N 99.92W 04/10/2013 E0.10 INCH HARMON OK EMERGENCY MNGR 1000 AM FREEZING RAIN TALOGA 36.04N 98.96W 04/10/2013 E0.25 INCH DEWEY OK CO-OP OBSERVER 1000 AM FREEZING RAIN WEATHERFORD 35.53N 98.70W 04/10/2013 E0.25 INCH CUSTER OK CO-OP OBSERVER 1002 AM FREEZING RAIN PERRY 36.29N 97.29W 04/10/2013 E0.05 INCH NOBLE OK CO-OP OBSERVER GLAZE OF ICE ON ELEVATED SURFACES. 1020 AM FREEZING RAIN CHILLICOTHE 34.26N 99.51W 04/10/2013 E0.25 INCH HARDEMAN TX PUBLIC 1022 AM FREEZING RAIN VERNON 34.15N 99.29W 04/10/2013 E0.25 INCH WILBARGER TX FIRE DEPT/RESCUE 1030 AM FREEZING RAIN CROWELL 33.98N 99.72W 04/10/2013 E0.25 INCH FOARD TX PUBLIC 1030 AM FREEZING RAIN CYRIL 34.90N 98.20W 04/10/2013 E0.25 INCH CADDO OK CO-OP OBSERVER 0134 PM FREEZING RAIN 3 SSE NORMAN 35.18N 97.42W 04/10/2013 E0.10 INCH CLEVELAND OK NWS EMPLOYEE GLAZE OF ICE ON TREES AND CARS AT THE NWS OFFICE.
PRELIMINARY LOCAL STORM REPORT...SUMMARY NATIONAL WEATHER SERVICE NORMAN OK 737 AM CDT WED APR 10 2013 ..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON... ..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE.... ..REMARKS.. 0540 PM HAIL 3 N RED SPRINGS 33.66N 99.42W 04/09/2013 E1.00 INCH BAYLOR TX CO-OP OBSERVER 0700 PM NON-TSTM WND GST 3 W MEDICINE PARK 34.73N 98.55W 04/09/2013 M58.00 MPH COMANCHE OK MESONET 0733 PM HAIL 14 SSW ARCHER CITY 33.41N 98.72W 04/09/2013 E2.75 INCH ARCHER TX TRAINED SPOTTER 0807 PM HAIL 4 S WINDTHORST 33.52N 98.44W 04/09/2013 M1.75 INCH ARCHER TX TRAINED SPOTTER 0809 PM HAIL WINDTHORST 33.58N 98.44W 04/09/2013 E1.00 INCH ARCHER TX TRAINED SPOTTER 0820 PM HAIL 1 W DEER CREEK 33.63N 98.29W 04/09/2013 E1.00 INCH CLAY TX AMATEUR RADIO 0821 PM HAIL VICI 36.15N 99.30W 04/09/2013 E1.75 INCH DEWEY OK PUBLIC 0821 PM HAIL 3 E WINDTHORST 33.58N 98.38W 04/09/2013 M2.00 INCH CLAY TX TRAINED SPOTTER 0823 PM HAIL VICI 36.15N 99.30W 04/09/2013 E1.00 INCH DEWEY OK TRAINED SPOTTER ALSO FREEZING RAIN. 0829 PM HAIL BLUEGROVE 33.67N 98.23W 04/09/2013 E1.00 INCH CLAY TX PUBLIC 0910 PM NON-TSTM WND GST 3 W MEDICINE PARK 34.73N 98.55W 04/09/2013 M60.00 MPH COMANCHE OK MESONET 0929 PM HAIL 5 SW DEER CREEK 33.58N 98.34W 04/09/2013 E1.00 INCH CLAY TX TRAINED SPOTTER 0935 PM HAIL KAMAY 33.85N 98.82W 04/09/2013 E1.00 INCH WICHITA TX TRAINED SPOTTER 0952 PM HAIL 6 SW GRANDFIELD 34.17N 98.76W 04/09/2013 E1.75 INCH TILLMAN OK PUBLIC 1001 PM HAIL GRANDFIELD 34.23N 98.69W 04/09/2013 E1.00 INCH TILLMAN OK AMATEUR RADIO 1005 PM HAIL GRANDFIELD 34.23N 98.69W 04/09/2013 E1.25 INCH TILLMAN OK AMATEUR RADIO 1005 PM HAIL HENRIETTA 33.82N 98.19W 04/09/2013 E0.75 INCH CLAY TX AMATEUR RADIO 1046 PM HAIL 5 N ALTUS 34.71N 99.33W 04/09/2013 E0.88 INCH JACKSON OK AMATEUR RADIO HAIL COVERAGE WAS REPORTED TO BE 1.5 INCHES DEEP. 1100 PM HAIL ALTUS AIR FORCE BASE 34.66N 99.29W 04/09/2013 E0.75 INCH JACKSON OK TRAINED SPOTTER 1125 PM HAIL HYDRO 35.55N 98.58W 04/09/2013 E0.25 INCH CADDO OK LAW ENFORCEMENT 1125 PM NON-TSTM WND GST 3 W MEDICINE PARK 34.73N 98.55W 04/09/2013 E62.00 MPH COMANCHE OK MESONET 1155 PM HAIL BENJAMIN 33.58N 99.79W 04/09/2013 E1.00 INCH KNOX TX COUNTY OFFICIAL 1230 AM NON-TSTM WND GST 3 W MEDICINE PARK 34.73N 98.55W 04/10/2013 M59.00 MPH COMANCHE OK MESONET 1245 AM HAIL 1 SW VERNON 34.14N 99.30W 04/10/2013 E0.50 INCH WILBARGER TX AMATEUR RADIO 1256 AM HAIL 5 N MEDICINE PARK 34.80N 98.50W 04/10/2013 E1.00 INCH COMANCHE OK BROADCAST MEDIA
The above animation shows radar reflectivity from 3 pm CDT on the 9th to 2 pm CDT on the 10th. Initially, isolated severe storms can be noted, with a transition to more widespread showers and storms as the loop progresses.
The animated GIF above shows the evolution of the cold front across Oklahoma from 6:00 AM CDT on the 9th, to 6:00 AM CDT on the 10th.