March 30, 2012 Chase Recap
- Published on Friday, 30 March 2012 23:50
- David Reimer
Sadly, days that end up busting are usually the easiest logs to write since they’re short and to the point. Jenny and I left her house just southeast of Denton around 12:45 PM. We took the brief jog northbound on Interstate 35E before turning west onto Highway 380. We debated about continuing west or going more to the north on Highway 287. We ended up choosing Highway 287. It took us just over an hour to reach Wichita Falls, where we ended up staying for 30 minutes before deciding we needed to move back south. After an hour drive south on Highway 281, we arrived in Jacksboro where we met up with several other chasers. We sat around at a local gas station for about two hours until it became obvious that the cap was going to win and that no thunderstorms would be able to develop. We called the chase at 6:30 PM and headed back to town for dinner.
[caption id="attachment_6990" align="aligncenter" width="600" caption="March 30, 2012 7 PM Fort Worth Sounding"][/caption]
A weather balloon launched from the National Weather Service in Fort Worth clearly shows why we did not have any thunderstorms this afternoon. While instability amounts were quite high and wind shear sufficient to support severe storms, a strong cap remained in place. You can see the inversion layer encased by a black line on the Skew-T while I’ve highlighted the convective temperature below. According to the data measured by the weather balloon, the surface temperature needed to reach 89°F for the cap to break and to support thunderstorms. We generally saw high temperatures of around 82°F to 84°F. We were close to having a few severe storms, but no cigar today.
Severe Thunderstorm Watch being considered for Hill Country/Western N. TX
- Published on Friday, 30 March 2012 17:08
- David Reimer
The Storm Prediction Center has indicated that they are considering a severe thunderstorm watch for parts of the Texas Hill County and the western portions of North Texas. The primary uncertainty is if thunderstorms will be able to break through a strong cap and develop. If the cap remains in place, no storms will develop. However, there is a chance a few storms could form. Any storm that forms this afternoon will have the potential to rapidly become severe weather very large, destructive hail. Depending on the trends over the coming hours, a severe thunderstorm watch may be issued.
Here is the full mesoscale discussion from SPC. Warning, this contains a bunch of nerdy words.
MESOSCALE DISCUSSION 0391
NWS STORM PREDICTION CENTER NORMAN OK
0459 PM CDT FRI MAR 30 2012
AREAS AFFECTED...CNTRL/NW TX
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 302159Z - 302300Z
A THREAT FOR LARGE HAIL AND ISOLATED DMGG WIND GUSTS MAY DEVELOP
WITHIN THE NEXT 1-2 HRS OVER PORTIONS OF CNTRL TX. TSTM COVERAGE
REMAINS SOMEWHAT UNCERTAIN...BUT CONVECTIVE TRENDS ARE BEING
MONITORED FOR A POSSIBLE WW.
TOWERING CU FIELD HAS BECOME MORE AGITATED IN RECENT VISIBLE
SATELLITE IMAGES E OF JCT...FORMING ALONG/NEAR A WEAKLY
CONFLUENT/DIFFUSE DRYLINE. STRONG DAYTIME HEATING HAS LIKELY
RESULTED IN EROSION OF MOST CINH...AND AS WEAK FORCED ASCENT
ACCOMPANYING AN UPPER IMPULSE /NOTED IN WATER VAPOR IMAGERY OVER NW
TX/ OVERSPREADS THE AREA...DEVELOPMENT OF A FEW TSTMS SHOULD BECOME
MORE PROBABLE PRIOR TO SUNSET. WITH MODEST MIDLEVEL WLY FLOW /E.G.
15-20 KTS AT 6 KM AGL PER LDB PROFILER/...STORMS SHOULD SLOWLY
PROGRESS E-SEWD INTO A MORE MOIST/UNSTABLE ENVIRONMENT...WITH
MODIFIED FORECAST SOUNDINGS SHOWING MLCAPE VALUES EXCEEDING 3000
J/KG. PRIMARY THREAT WITH THESE TSTMS APPEARS TO BE HAIL /SOME VERY
LARGE/...AS WELL AS ISOLATED DMGG WIND GUSTS GIVEN A HOT/WELL-MIXED
BOUNDARY LAYER. ONE FACTOR PRECLUDING A MORE SIGNIFICANT/WIDESPREAD
THREAT WILL BE WEAK DEEP-LAYER SHEAR LIMITING STORM
ORGANIZATION...FAVORING PULSE TO MULTICELL CONVECTIVE MODES.
THIS...COMBINED WITH EXPECTED SPARSE COVERAGE OF CONVECTION...WILL
LEAD TO UNCERTAINTY WHETHER A WW WILL BE REQUIRED...BUT TRENDS WILL
CONTINUE TO BE MONITORED OVER THE NEXT 1-2 HRS.
Isolated Severe Weather Threat across North Texas Today
- Published on Friday, 30 March 2012 10:11
- David Reimer
[<strong class='StrictlyAutoTagBold'>captionstrong> id="attachment_6979" align="aligncenter" width="600" <strong class='StrictlyAutoTagBold'>captionstrong>="Friday's Severe Weather Outlook"][/<strong class='StrictlyAutoTagBold'>captionstrong>]
The Storm Prediction Center has issued a standard risk of <strong class=’StrictlyAutoTagBold’>severestrong> weather for a small portion of Southwest <strong class=’StrictlyAutoTagBold’>Texasstrong> northward to the Red River Valley into Oklahoma. Due to a strong cap in place today, <strong class=’StrictlyAutoTagBold’>thunderstormstrong> develop is expected to remain quite isolated. In fact, it’s certainly possible that no storms at all are able to form today. I’ve highlighted two zones I believe are most likely to see a <strong class=’StrictlyAutoTagBold’>thunderstormstrong> develop in <strong class=’StrictlyAutoTagBold’>this afternoonstrong>. Any <strong class=’StrictlyAutoTagBold’>thunderstormstrong> that develops <strong class=’StrictlyAutoTagBold’>this afternoonstrong> will have the potential to produce giant, destructive hail and strong outflow winds. While only one or two storms may develop <strong class=’StrictlyAutoTagBold’>this afternoonstrong>, they will likely be very <strong class=’StrictlyAutoTagBold’>severestrong>. We’ll be chasing <strong class=’StrictlyAutoTagBold’>this afternoonstrong> and will provide updates as the day rolls on.