May 10-11 Chases

I had a couple of off days on Monday and Tuesday, so I took the opportunity to take a mini chase vacation with my buddies Michael Carter, Greg Nordstrom, and Tim Wallace. Fortunately, the weather pattern was very cooperative from a chasing standpoint, and we all felt confident about a powerful western U.S. trough impacting the southern Plains more than a week and a half before the event. Unfortunately, damage, injuries, and fatalities occurred as a result of the May 10 tornadoes across Central Oklahoma. As part of a quick recap, I've compiled some video, links, and damage surveys from the wedge tornado we came within at least 200 yards of near Cromwell, OK.

VIDEOS

Video by Greg Nordstrom

Video by Michael Carter

May 10, 2010 Tornado Outbreak -- WFO Norman

May 10, 2010 Severe Storms and Tornadoes -- WFO Tulsa

CIMSS Satellite Perspective

Michael Carter's Chase Summary

STORM SURVEYS

-From WFO Norman-
...TECUMSEH TO CROMWELL AND POINTS EAST TORNADO...

RATING: EF-3
MAX WIDTH: 3/4 TO 1 MILE
PATH LENGTH: AT LEAST 30 MILES ONLY COUNTING NWS NORMAN PORTION
BEGIN POINT: ABOUT 2.8 WSW TECUMSEH
END POINT: CONTINUED INTO NWS TULSA AREA ABOUT 0.8 E CROMWELL

THIS LONG TRACK TORNADO MOVED FROM POTTAWATOMIE COUNTY INTO SEMINOLE COUNTY...AND THEN CROSSED INTO OKFUSKEE COUNTY WHICH IS IN THE NWS TULSA COUNTY WARNING AREA. THE TORNADO CAUSED SIGNIFICANT DAMAGE ALONG THE ENTIRE TRACK...WITH NO NOTABLE GAPS IN DAMAGE ALONG THE LENGTH OF THE PATH SURVEYED. AT TIMES...THE DAMAGE FIELD WIDENED TO ABOUT 3/4 OF A MILE WIDE...POSSIBLY UP TO 1 MILE WIDE. THE MOST INTENSE DAMAGE SEEMED TO BE JUST NORTH AND NORTHEAST OF EARLSBORO NEAR THE POTTAWATOMIE-SEMINOLE COUNTY BORDER. IT WAS IN THIS LOCATION THAT A 5 BEDROOM...2 STORY FOUNDATION HOUSE WAS DESTROYED EXCEPT FOR SEVERAL INTERIOR WALLS NEAR THE BATHROOM. IN THIS SAME VICINITY...A PICKUP TRUCK APPEARED TO HAVE BEEN LOFTED FOR ABOUT 1/4 MILE...AND A SEMI TRAILER WAS ROLLED OR LOFTED FOR A FEW HUNDRED YARDS. BOTH OF THESE LARGE MISSILES WERE DRAWN FROM THE NORTHERN HALF OF THE DAMAGE PATH TOWARDS THE CENTER. A LITTLE FURTHER EAST...7 HIGH TENSION TOWERS WERE DOWNED. ALONG THE ENTIRE PATH...TREE DAMAGE WAS NOTED...AND A FEW TREES WERE DEBARKED AND STRIPPED OF ALL THEIR BRANCHES.


-From WFO Tulsa-
A TORNADO THAT MOVED ACROSS PORTIONS OF NORTHERN HUGHES COUNTY...INCLUDING THE TOWN OF CROMWELL...CROSSED INTO SOUTHWESTERN OKFUSKEE COUNTY 3 MILES WEST OF BEARDEN AT ABOUT 635 PM CDT. THE TORNADO MOVED NORTHEAST AND DISSIPATED JUST SOUTH OF I-40 ABOUT 3 MILES NORTH OF BEARDEN AT ABOUT 647 PM CDT. MANY TREES WERE DAMAGED IN THE PATH...WHICH WAS ABOUT 5 MILES LONG AND HAD A MAXIMUM WIDTH OF 400 YARDS. BASED ON THE TREE DAMAGE...THE TORNADO WAS RATED EF-1 ON THE ENHANCED FUJITA SCALE WITH MAXIMUM WIND OF UP TO 95 MPH.

MAY 11
This day proved to be a lot quieter than May 10, but one dominant supercell did develop ahead of the triple point across Northwest Oklahoma. After a couple of rounds of deep moist convection failed to sustain itself, likely due to a capping inversion, one LP supercell developed near Crawford, OK just after 6:30 p.m. The supercell slowly moved to the northeast, produced significant hail southwest of Woodward, and eventually dissipated near Freedom, OK. The laminar nature of the storm's base prevented this from being a tornado threat, but hordes of chasers were treated to a beautiful spectacle at sunset.

Video by Greg Nordstrom

Satellite Perspective of April 24 Tornado Outbreak

CIMSS has put together a very good satellite analysis of the April 24, 2010 tornado outbreak across the Deep South. A few MODIS images are included at the bottom of the recap, which show the tornado scar left in the wake of the Yazoo City tornado.

CIMSS - Deadly tornado outbreak across the Deep South

Yazoo City Tornado Chase Accounts

I've linked a couple of worthwhile storm chase accounts about the preliminarily rated EF3 tornado in Yazoo City, MS on April 24, 2010. Two of my good buddies, Greg Nordstrom and Michael Carter, provide some insight into the synoptic and mesoscale setup for yesterday's tornado outbreak and discuss issues related to storm chasing in the Deep South.

Greg Nordstrom's Chase Recap

Michael Carter's Chase Recap

Snow Overnight, Near Blizzard Conditions Possible

Big changes are in store today as a strong trough approaches from the Four Corners region. At the surface, a cold front currently stretches from the Lower Peninsula of Michigan to Central Kansas to Morton, TX along with a weak surface low near Plainview. Due to the anafrontal nature of the front, almost all of the precipitation is well behind the front across Colorado, Nebraska, and Northwest Kansas. There are a few patches of drizzle across the Panhandle, but the main brunt of the precipitation will arrive overnight. In the meantime, skies will become increasingly cloudy as the day progresses. The warmest temperatures of the day occurred at midnight, but temperatures this afternoon will warm slightly to around 44. With a tightening pressure gradient at the surface, winds could gust as high as 35 mph, especially after 5 p.m.

By this evening, the frontal boundary should be well south of the area with an a surface low just north of Midland. This system will deepen and move eastward as strong dynamics eject eastward. As DPVA impinges of the Panhandle, deep layer ascent will support a band of snow that will be moving into the area from the northwest and New Mexico. Once the snow begins after 10 p.m., it should last through Saturday afternoon. The snow will increase in intensity between midnight and 4 a.m. as impressive omega lifts abundant moisture into the snow growth region. Snow ratios will range from 12:1 at the onset of the event to 25:1 at the end of the event. This will support a wide range of totals across the area, but Amarillo will likely end up with around 6" of snow after accounting for above freezing ground temperatures that will initially reduce accumulations. NNE winds will become very strong tonight with gusts possibly up to 50 mph, particularly after midnight. This will cause considerable blowing and drifting of snow and present significant travel problems. Lows tomorrow morning will be near 23, but strong winds will likely result in wind chills near 0 at times.

Mostly Sunny, Mild

In advance of a potent trough moving through the Pacific Northwest, an upper level ridge will become established across the entire region today. At the surface, weak low pressure in eastern Colorado and high pressure across the Texas Gulf Coast will produce a breezy southerly flow with some gusts up to 25 mph this afternoon. This will result in a beautiful day with mostly sunny skies and mild temperatures. A few high clouds could pass across the area at times today, but these should stay mostly north of Amarillo. Highs this afternoon will top out around 69. Clouds will be thickening and lowering this evening as the trough digs into the Southwest U.S. Ahead of a cold front approaching the Panhandles, the combination of increasing clouds and southerly winds will result in warmer temperatures tomorrow morning with lows around 40.

Mostly Sunny, Pleasant

The strong shortwave trough and associated rain shield that affected the region yesterday is slowly rotating eastward across the Permian Basin. The Panhandle region will experience deep layer subsidence today in the wake of this system and as high pressure builds in from the north. As a result, clouds should dissipate shortly and allow for an abundant supply of sunshine after 9 a.m. Highs will top out around 58. North northwest winds will be breezy today with some gusts up to 20 mph possible. Another disturbance will approach the area from the north tonight, but there will be no moisture to work with. Therefore, skies will be mostly clear with light winds and dry air, which should allow lows to dip down to 32 tomorrow morning.

Rain This Morning, Mixing With Snow This Afternoon

Upper air analysis shows a shortwave trough centered over Southwest New Mexico. The main forcing associated with the shortwave will move through the Trans-Pecos region, but some weak disturbances will rotate around the trough. These disturbances have resulted in some areas of moderate to heavy rain and thunderstorms this morning across the region, but mainly light rain has fallen so far in Amarillo. Rain will continue this morning and will likely increase in intensity. Rain and clouds will keep temperatures on the chilly side today with temperatures slowly dropping into the mid 30s by this afternoon. Forecast soundings suggest that wet snow will begin to mix with the rain around noon and then transition to all snow this afternoon as wet bulb zero heights drop under 1,200 feet. It's possible that there could be some minor accumulations (i.e. a dusting or less) of snow on grassy and elevated surfaces, but the recent warm temperatures have allowed soil temperatures to increase. Another forecast consideration today will be the strong northeast winds, which could gust as high as 30 mph. The snow should by 10 p.m., but clouds will hang tough overnight. Lows tomorrow morning will be near 32.