Archive for the 'Analysis' Category
Monster hail reported from N TX yesterday
Activity yesterday has been slightly more isolated than it was expected from the model runs before, strong cap did hold most of the airmass well capped below EML. SPC had downgraded the outlook to SLGT risk at 20z yesterday, as widespread initiation was not expected anymore. But environment still showed a classic loaded gun sounding as can be seen on the DFW sounding below and it was just about a matter of stronger SFC convergence to initiate storms:
During the late afternoon into the evening hours, warm front stoped moving north as evident OFB was coming from the MCS on going in ECNTRL OK mentioned in the forecast yesterday, and became Q-stationary in N TX near I-20. Dryline was mixing from west TX as SFC low was deepening over NM/W TX state border as well as increasing LLJ jet was ahead of it, nosing LL thermal ridge towards north TX. As can be seen on the 00z SFC analysis below, triple point was located just west of Abilene in that time, while warm front was extending Ewards just north of I-20 into northern LA.
At around 23z, on VIS satellite imagery rapidly growing cumulus clouds were evident along the warm frontal boundary just NE of Abilene, in the line Albany-Breckenridge-Weatherford and initiation was just about to start as cap weakened. First storm fired up just east of Albany, but quickly dissapeared as it appears cap was still too strong and did not allow it to organize.
However, it did not last long before another cell exploded practically over the same area, likely slightly improved SFC convergence played a role fo its initiation, probably also from the previous cell. This one then extremely rapidly became organized and took supercell caracteristics. Given the above DFW loaded gun sounding and having in mind upper 60s to low 70s SFC dewpoints in place with overlaping 60kts+ of 0-6km bulk shear, such rapid development was expected. Storm quickly became severe and soon made a right moving mode which turned to start hailing with large monster hail.
Zoom-in into this cell, a strong hailcore well visible, as well asclassic hook feature:
Several chasers and spotter in the area of it were reporting extremely large hail up to baseballs and softballs (4-5″ = 10-13cm in diameter!) and many of them got caught in the main hailcore, damage their vehicles and windshields. On this supercells, large wall clouds were observed, but no tornadoes spotted. This radar image is pretty ineteresting, showing many chasers/spotters extending along road US180 just east of Breckenridge.
Below are several hail reports on SPC website of giant hail from this supercell, as well as a video of a storm chaser Connor McCrorey who got caught by this monster hail:
0100 200 3 NW STRAWN PALO PINTO TX 3258 9853 SPOTTER NETWORK REPORT OF 2 INCH HAIL 3 MILES NW OF STRAWN (FWD)
0101 400 5 W STRAWN STEPHENS TX 3255 9858 STORM CHASER HAD CAR DAMAGED BY 4 TO 5 INCH HAIL ON HWY 207 WEST OF STRAWN. (FWD)
0128 275 6 N HUCKABAY ERATH TX 3243 9830 SPOTTER NETWORK REPORT OF BASEBALL HAIL 2 MIELS ENE OF THURBER (FWD)
Giant hail – courtesy of Connor McCrorey.
Later on, when LLJ increased, an elevated storms began to fire on its nose over ECNTRL OK into NE TX and an overnight MCS was racing Ewards towards S AR/N LA with hail and damaging winds as the main threat.
10th anniversary of May 3rd 1999 tornado outbreak in central OK
On May 3rd, 1999 a major historical tornado outbreak hit central OK, parts of TX and KS. Numerous large and violent tornadoes causes extensive damage with 40 deaths and more than 600 injured in OK where the most memorable event was F5 tornado which hit Moore and southern Oklahoma City metro area. Additionally, few deaths and injured people were also reported from Wichita, KS metro area.
Below is likely the most known radar image of a classic hook echo feature which is usually a sign of a tornado-producing supercell thounderstorm. In addition, there is also another radar image where tornado was passing I35 from Oklahoma City – Moore. On the right side, SR velocity image is attached.
This image shows approximate locations and paths of the most damaging tornadoes occured in central Oklahoma state:
Please, refer to these additional links to read some more interesting information about this historic event:
Southwards racing cold front across NE/IA
A deepening trough is underway over western US Conus and will affect the Plains from today forwards for the next couple of days. On the surface, a strong cold front is currently racing southwards across Northern Plains and is the focus for today’s storm initiation in extreme SE NE into central IA and NEwards along this frontal boundary.
This cold frontal boundary was easily recognized on radar and satellite imagery earlier, here are radar and satellite image between 2130z and 22z…
And images later around 00z with storms firing up along the boundary… mainly with threat for large hail:
Here is the surface analysis around 00z with cold front extending from central WI through central IA and SE NE into NWRN KS.
This strong southwards surging cold front will be the main focus also for tomorrow’s weather over south-central Plains where severe storms with very large hail, strong winds and tornadoes are possible from TX Panhandle into west-central OK. More about this setup will be added later.
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