Texas Spring-2014

[Portastorm]

Much obliged to aggiecutter and dhweather for the images posted today. Good discussion too! Thanks everyone. Let's hope this rain event comes through for us.

[Portastorm]

Encouraging little tidbit from the afternoon area forecast discussion (AFD) out of NWSFO Dallas/Fort Worth (FWD):

UNLIKE MANY SPRING SYSTEMS...A NOTABLE COLD FRONT WILL NOT FOLLOW
ON THE HEELS OF THE UPPER TROUGH. THEREFORE...LOW LEVEL MOISTURE
WILL REMAIN HIGH ACROSS NORTH TEXAS THROUGH THE WEEKEND.
ALSO...NEARLY ZONAL FLOW ALOFT WILL BECOME ESTABLISHED ACROSS THE
SOUTHERN HALF OF THE CONUS LATE IN THE WEEKEND THROUGH EARLY NEXT
WEEK. WEAK DISTURBANCES EMBEDDED IN WESTERLY FLOW ALOFT WILL BRING
ADDITIONAL RAIN AND THUNDERSTORM CHANCES TO ALL OF NORTH TEXAS.
FOR NOW WE WILL KEEP POPS ON THE LOW SIDE. HOWEVER...A LATE SPRING
PATTERN SUCH AS THIS OFTEN RESULTS SCATTERED TO NUMEROUS
THUNDERSTORMS OVER MULTIPLE DAYS.

[dhweather]

oh please please please please please happen. I doubt one person here would turn down a drop of rain. But that's been the problem, a drop here, a drop there. We need lots of drops.

[Ntxw]

Breaking news from EnSo. For the first time this nino has all four regions of the equatorial Pacific are above the 0.5C threshold in the daily's.

[weatherdude1108]

I'll take the RAIN without the severe threat, please.

[gboudx]

:uarrow: oh please please please please please happen. I doubt one person here would turn down a drop of rain. But that's been the problem, a drop here, a drop there. We need lots of drops.

Today, from where the Ray Hubbard shoreline used to be on my end of the lake, I road my mountain bike to the edge of the water. It was 0.6 miles. I passed a dead tree along the way and the obvious water line was about 5' up. Yeah millions of raindrops please.

[aggiecutter]

Question for anyone concerning the SPC's SREF Ensemble Model. Under the precipitation tab there is a field called MAX. There are several of them associated with different time frames ie 6-12-24hrs. I am wrong in thinking this is the MAX potential rainfall that could fall during that time frame, rather than an average or median that could fall within a given area. I'm thinking the former when comparing it to the model's probability of an amount of precipitation falling during a given time frame.

the link:
http://www.spc.noaa.gov/exper/sref/

[South Texas Storms]

I think it's the maximum precipitation total that one of the ensemble members of the SREF is forecasting.

[aggiecutter]

:uarrow:
I think it's the maximum precipitation total that one of the ensemble members of the SREF is forecasting.

Are you saying that is the highest precipitation amount"MAX" that a particular SREF member forecasted. ie the highest of all the members.

[aggiecutter]

Portastorm having his favorite beverage before going on the chase:

[South Texas Storms]

:uarrow:
I think it's the maximum precipitation total that one of the ensemble members of the SREF is forecasting.

Are you saying that is the highest precipitation amount"MAX" that a particular SREF member forecasted. ie the highest of all the members.

Yeah that's what I think. I'm not totally sure though.

[gboudx]

Here's an update from jeff. It's mostly focused for you folks in Central/SE Tx.

Powerful upper level storm system to affect TX Thursday-Saturday.

Current upper level trough over the western US will slowly progress into the plains today into Thursday. Southerly winds will begin rich moisture advection today with dewpoints and PWS increasing. Eastern Pacific tropical system (90E) located south of the Mexican coast this morning is already starting to spread mid and high level moisture northward into MX and as far north as southern TX.

Factors appear to be attempting to come together for a period of active weather from Thursday afternoon/evening into early Saturday. Trough position on Thursday will be close enough to SE TX to support enough cooling in the mid level to help erode the capping inversion. Dryline feature across central TX should help to develop isolated to scattered strong thunderstorms by the late afternoon hours which will then move eastward toward the area. Unfavorable jet structure will likely limit the amount of development and the eastward movement of any storms. This thinking place our western counties with the greatest rain chances on Thursday.

Friday appears to be setting up to be the day when ingredients peak for thunderstorms and possibly heavy rainfall. A potent short wave rotates through the base of the large scale trough early Friday and will likely develop a band or cluster of thunderstorms over SW TX into WC TX. Downstream air mass over C and SE TX will heat throughout the day and moisten with forecasted PWS values of 1.75 to 2.0 inches and instability of 2500 to 3000 J/kg. Upper level sub-tropical jet begins to split over the area by the afternoon hours yielding greater lift and mid level capping should be a non-factor for the first time in months. Incoming short wave and potential convective cluster/MCS (Mesoscale Convective System) should be able to maintain convection into the area Friday afternoon/evening. Global models have not been handling the placement of the highest QPF (rainfall) with this event well at all and continue to be all over the place. The GFS is drier than the ECMWF mainly due to its placement of the greatest lift and failure to develop a surface trough over the area. While I would like to side with the wetter ECMWF, we are in a drought, and thus far this year the drier model has verified the best. With that said, the potential is certainly there for some heavy rainfall Friday afternoon and evening, but with the mesoscale features taking over it is nearly impossible to predict where the greatest rains will fall. A severe threat will be possible also with the storms that develop on Friday.

Looks like a break in the rainfall potential for the weekend, although could still see some lingering activity Saturday morning. There is some potential for some additional development late in the weekend or early next week, but this is fairly uncertain.

[dhweather]

From: National Weather Service, Fort Worth
Date: Wednesday, 7 May 2014 13:54 CDT

Good afternoon,

Isolated thunderstorms are in the forecast for most of north and central Texas through this afternoon. However, the potential for severe thunderstorms late this afternoon and this evening is confined to a small western portion of the area. There is a somewhat greater potential for severe weather beginning late tonight and into the day Thursday. A short pdf has been included to depict timing, impacts and areas likely to be affected through Thursday.

BOTTOM LINE: Areas to the west of a line from Jacksboro to Granbury to Goldthwaite should be prepared for the possibility of isolated severe thunderstorms from 5 pm to 9 pm today. Emergency Managers, public safety and elected officials, and storm spotters should be prepared for thunderstorms and a severe weather potential late tonight through Thursday.

IMPACTS: The primary threats for this afternoon and evening are damaging winds and large hail. The primary threats for late tonight into Thursday evening will be large hail, damaging winds, and a low potential for flash flooding. The potential for tornadoes across north and central Texas on Thursday afternoon is very low, but not zero.

AREA OF GREATEST CONCERN: This afternoon and evening: western sections of north Texas including Graham, Mineral Wells, Stephenville and Comanche. For late tonight into Thursday: all areas of north and central Texas. The severe weather potential will gradually diminish from west to east during the afternoon and evening hours on Thursday.

TIMING: The severe weather threat in the western areas this afternoon and evening will be from 5 PM to 9 PM. For tonight into Thursday, strong to severe thunderstorms will begin spreading into western sections of north Texas after midnight tonight, and will gradually spread into eastern sections of the area during the rest of the morning and afternoon hours on Thursday.

FORECAST CONFIDENCE: There is low confidence in the forecast for this afternoon and evening and overall moderate confidence in the forecast for late tonight into Thursday.

ALTERNATE SCENARIOS: All of these scenarios are possible late tonight into Thursday, in general order of likelihood:

Thunderstorms become widespread, but not severe, Thursday morning and a few severe storms develop east of I-35 on Thursday afternoon and evening.
Rain and thunderstorms become widespread late tonight and Thursday, and keep the atmosphere too stable for severe thunderstorm development in any area of north Texas through Thursday evening.
Rain and thunderstorm activity late tonight and Thursday morning is very limited, and sunshine allows the atmosphere to become extremely unstable in some areas by Thursday afternoon. Scattered severe thunderstorms, with very large hail and a tornado threat, develop across some part of north or central Texas on Thursday afternoon.

[aggiecutter]

WPC's, formerly the HPC, 7 day accumulated rainfall projections:

[Ntxw]

GFS coming around to other models for tomorrow. Nice swath of water a good area of Texas. Should be a wet day tomorrow for the I-35 corridor

[gpsnowman]

I have an off day tomorrow. Can not wait to see the storms as I sit at home. Bring it.

[dhweather]

It's not looking too promising on radar thus far, I hope things pick up quickly.

[Ntxw]

HRRR while overdoing it probably, trains an intense band later this evening over I-35 quickly dumping 2-4 inches of rain. I'd trim it down a little bit due to it being a high res model, but other guidance follows suit (except the GFS which has been flopping back and forth between wet and dry) for a possible training event. 90E is coming up from Mexico, lets see how much much moisture feeds trains.



Next 7 days continue to look active

[Rgv20]

NWS Brownsville Morning Discussion....For early next week.

THE MAIN CONCERN IN THE LONG TERM PORTION OF THE FORECAST CENTERS
ON MONDAY NIGHT THROUGH TUESDAY...AS BOTH THE GFS AND EUROPEAN
INDICATE THAT A COLD FRONT...ASSOCIATED WITH A DEEPER 500 MB
TROUGH MOVING THROUGH THE CENTRAL PLAINS...WILL PRODUCE WIDESPREAD
SHOWERS AND THUNDERSTORMS WITHIN THE BRO CWFA. HAVE KEPT LOW-END
SCATTERED CONVECTION IN THE FORECAST FOR THE MONDAY NIGHT THROUGH
TUESDAY TIME FRAME...WITH THE FUTURE POTENTIAL THAT THE CONVECTION
MAY NEED TO BE UPGRADED TO HIGH-END SCATTERED OR EVEN NUMEROUS IN
COVERAGE. STILL TOO EARLY TO KNOW IF ANY OF THE THUNDERSTORMS WILL
BE STRONG OR SEVERE IN NATURE...AND THIS IS SOMETHING THAT WILL
NEED TO BE MONITORED BY SUCCESSIVE SHIFTS THROUGH THE WEEKEND.

[gpsnowman]

Heavy rain at the house. What a wonderful sight and sound.