Texas Spring-2015

[Ntxw]

And there you have it. I guess I will be turning my sprinklers on. My life story.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1106 PM CDT SUN APR 12 2015

.UPDATE...
GRIDS AND ZONES HAVE BEEN UPDATED TO CANCEL SEVERE THUNDERSTORM
WATCH #57. CAPPING EVIDENT ON 00Z DRT SOUNDING AT 4-5 KFT AND SPC
MESOANALYSES LIKELY PREVENTED SEVERE WINDS FROM MIXING DOWN TO THE
SURFACE EARLIER THIS EVENING...AND THIS CONVECTIVE INHIBITION
CONTINUES TO SPREAD OUT IN FRONT OF THE ONGOING LINE OF STORMS.
STRONGER SHEAR VALUES HAVE ALSO REMAINED SOUTH OF OUR CWA. ALTHOUGH
A FEW SPOTS OF LOCALLY HEAVY RAINFALL WILL BE POSSIBLE WHERE
CONVECTIVE ELEMENTS BRIEFLY TRAIN IN FRONT OF THE MAIN CONVECTIVE
LINE...HIRES MODELS SUGGEST THIS LINE WILL GRADUALLY WEAKEN AND
COVERAGE WILL BECOME LESS WIDESPREAD AS IT MOVES NORTHEAST. GRIDS
HAVE BEEN UPDATED TO REFLECT THESE TRENDS AS THE ATMOSPHERE SHOULD
STABILIZE FOR THE REST OF THE EVENING BEHIND THIS LINE.

Kinda a sad joke isn't it?! Austin has been stiffed multiple times in the last few weeks. I've lost track of how many ghost shortwaves were predicted along with attendant rain and they never happened. And then last night's "mighty" squall line which amounted to a tenth of an inch of rain. ha ha. Bring on the drought.

There there Portastorm lets not overreact! I know its tough watching areas around you get rain but you must remember last fall central Texas were the winners and Austin for the year so far is above normal. Lakes need help though, stay calm. At least the chance for rain every few days is there.

[gboudx]

Deluge going on in northern Tarrant and Dallas counties, watch out for flash flooding

We're going to fill up Lavon today!!

It'll be interesting to watch over the next day or 2 how much it rises. It's just under 4' from conservation pool elevation with lots of runoff in progress. Folks may not know this but Hwy 78 is being widened from Wylie to at least the town of Lavon. This stretch includes passing over the spillway from Lake Lavon to Ray Hubbard. Currently, construction crews have filled in a part of the East Trinity so they can traverse it while a new bridge and road construction is in progress. The new bridge is complete but they still use the temporary dirt road. If Lavon rises too high, prompting downstream flow release, it'll be interesting to see how it impacts the construction. There's currently a stretch where they are building dirt to elevate the road; and this area usually floods when the water is released. IIRC, the last time flow release was initiated was when Lavon hit 4-5' above pool.

[Portastorm]

What's that you say Ntxw ... don't overreact?! Why that's my specialty!

[weatherdude1108]

:uarrow:

What's that you say Ntxw ... don't overreact?! Why that's my specialty!

Haha! I tend to also feel the frustration when rain doesn't go my way. But I always like seeing Ntxw's calming/reasoning influence.

[weatherdude1108]

And there you have it. I guess I will be turning my sprinklers on. My life story.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1106 PM CDT SUN APR 12 2015

.UPDATE...
GRIDS AND ZONES HAVE BEEN UPDATED TO CANCEL SEVERE THUNDERSTORM
WATCH #57. CAPPING EVIDENT ON 00Z DRT SOUNDING AT 4-5 KFT AND SPC
MESOANALYSES LIKELY PREVENTED SEVERE WINDS FROM MIXING DOWN TO THE
SURFACE EARLIER THIS EVENING...AND THIS CONVECTIVE INHIBITION
CONTINUES TO SPREAD OUT IN FRONT OF THE ONGOING LINE OF STORMS.
STRONGER SHEAR VALUES HAVE ALSO REMAINED SOUTH OF OUR CWA. ALTHOUGH
A FEW SPOTS OF LOCALLY HEAVY RAINFALL WILL BE POSSIBLE WHERE
CONVECTIVE ELEMENTS BRIEFLY TRAIN IN FRONT OF THE MAIN CONVECTIVE
LINE...HIRES MODELS SUGGEST THIS LINE WILL GRADUALLY WEAKEN AND
COVERAGE WILL BECOME LESS WIDESPREAD AS IT MOVES NORTHEAST. GRIDS
HAVE BEEN UPDATED TO REFLECT THESE TRENDS AS THE ATMOSPHERE SHOULD
STABILIZE FOR THE REST OF THE EVENING BEHIND THIS LINE.

Kinda a sad joke isn't it?! Austin has been stiffed multiple times in the last few weeks. I've lost track of how many ghost shortwaves were predicted along with attendant rain and they never happened. And then last night's "mighty" squall line which amounted to a tenth of an inch of rain. ha ha. Bring on the drought.

There there Portastorm lets not overreact! I know its tough watching areas around you get rain but you must remember last fall central Texas were the winners and Austin for the year so far is above normal. Lakes need help though, stay calm. At least the chance for rain every few days is there.

I know! We had so much rain in the Fall and parts of Winter. My yard was a pond, like Brent's photo he posted earlier. Meanwhile, the lakes respond an inch to a foot, if that.

Now in just the last literally couple weeks, soil cracks have begun to form on those formerly ponded areas. Frustrating. I top dressed my yard a month ago when it was wet and had rained substantially a few days before. Soil cracks still formed eventually with the persistent 25 mph wind gusts with no rain. I suppose the compost prolonged the moisture in the soil, and the compost will be ingested by the cracks the next time we get a good rain, and not washing away in heavy rain event, which should improve the porosity over time. Trying to delay turning the sprinkler's on as long as possible. Deeper roots.

[weatherdude1108]

Just had to share Hampshire's discussion. I'm rooting for the ECMWF/CANADIAN in the long-term (Friday/Saturday)! Prolonged rain chances without severe weather.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
230 PM CDT MON APR 13 2015

.SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...
SKIES HAVE BECOME MOSTLY CLEAR ACROSS THE AREA AHEAD OF A SLOWLY
APPROACHING COLD FRONT. TEMPERATURES HAVE WARMED INTO THE UPPER
70S TO THE LOWER 80S. AT 2 PM...THE FRONT WAS ALONG A LINE FROM
NEAR SAN ANGELO TO HILLSBORO TO PARIS. HI-RES GUIDANCE IS SHOWING
THE FRONT NEARING OUR NORTHERN HILL COUNTRY COUNTIES LATER THIS
EVENING. THE OVERALL CHANCES FOR CONVECTION STILL APPEAR TO BE
MINIMAL AS DRIER AIR FILTERS INTO SOUTH-CENTRAL TEXAS WITHIN A
DRY-SLOT SOUTH OF THE MAIN UPPER LOW. THE BEST LIFT ASSOCIATED
WITH THE UPPER LEVEL LOW IS MOVING INTO NORTH TEXAS AND THE BEST
CHANCES FOR CONVECTION SHOULD COINCIDE WHERE THE FRONTAL BOUNDARY
COINCIDES WITH THE BEST LIFT AND MOISTURE. THE LATEST DAY 1
OUTLOOK FROM SPC HAS THE SLIGHT RISK NORTH OF OUR AREA AND OUR
CURRENT THINKING MATCHES WITH THIS FORECAST. CANT RULE OUT A
STRONG STORM ACROSS OUR FAR NORTHERN COUNTIES LATE THIS
EVENING...BUT THE OVERALL CHANCES OF THIS IS FAIRLY LOW. MOST
GUIDANCE IS SHOWING THE FRONT MOVING THROUGH THE CWA WITH NORTH
WINDS CONTINUING THROUGH THE SHORT TERM. GUIDANCE IS SUGGESTING A
CHANCE OF SHOWERS OR THUNDERSTORMS TOMORROW...MAINLY IN THE
SOUTHEASTERN COUNTIES BEHIND THE FRONTAL BOUNDARY. WEAK LIFT WILL
CONTINUE AS THE UPPER LOW REMAINS TO OUR NORTH AND SOUTHWEST FLOW
PREVAILS ALOFT. HIGHS TOMORROW WILL BE IN THE UPPER 70S/80S ACROSS
THE REGION WITH LOWS IN THE 50S/60S.

&&

.LONG TERM (WEDNESDAY THROUGH MONDAY)...
THE FORECAST FOR THE LONG TERM REMAINS PROBLEMATIC WITH LITTLE
CONFIDENCE AS MODELS CONTINUE TO HAVE VARYING SOLUTIONS. SOUTHERLY
FLOW IS EXPECTED TO RETURN ON WEDNESDAY AS THE UPPER LOW DEPARTS
TO THE NORTHEAST AND THE NEXT UPPER LOW APPROACHES THE SOUTHERN
PLAINS FROM THE WEST. AS THIS SYSTEM SLOWLY MOVES CLOSER TO THE
REGION THURSDAY....MODELS ARE SHOWING A LARGE AREA OF DECENT QPF
VALUES THURSDAY AFTERNOON. AM A LITTLE RELUCTANT TO BITE OFF ON A
WIDESPREAD RAINFALL EVENT AT THIS TIME. THERE IS LITTLE FOCUS AT
THE SURFACE FOR ACTIVITY AND LOW LEVEL WINDS REMAIN WEAK WHICH
WILL ONLY SUPPORT SMALL AMOUNTS OF LIFT ASSOCIATED WITH WARM AIR
ADVECTION. WILL ONLY GO 50 POPS FOR NOW FOR MUCH OF THE
AREA...EXCEPT FOR THE WESTERN COUNTIES WHERE 30/40 POPS ARE
FORECASTED.

BY FRIDAY...MODELS DIVERGE ON THE ULTIMATE PATH THE UPPER LOW WILL
TAKE. THE GFS KEEPS THE TRACK FAIRLY PROGRESSIVE WITH THE LOW
MOVING INTO TEXAS BY FRIDAY AFTERNOON. THE GFS THEN SENDS A DECENT
PACIFIC FRONT INTO THE AREA FRIDAY WITH A DECENT COVERAGE OF
SHOWERS AND THUNDERSTORMS ALONG AND JUST BEHIND THE FRONT BEFORE
DRIER AIR MOVES INTO THE AREA. IF THIS SOLUTION VERIFIES...THE
WEEKEND WOULD BE DRY. THE ECMWF/CANADIAN ARE SLOWER WITH THE PROGRESSION OF THE UPPER LOW BUT DO SEND IN A WEAK FRONT FRIDAY.
WITH THE UPPER LOW HANGING BACK...LIFT WOULD REMAIN IN PLACE
BEHIND THE FRONT LEADING TO CONTINUED CHANCES OF RAIN FRIDAY
THROUGH THE WEEKEND. WILL SHOW THE HIGHEST POPS ON FRIDAY AND
LINGER CHANCE POPS INTO SATURDAY WITH THE REST OF THE FORECAST
PERIOD DRY FOR NOW. IT IS STILL A BIT EARLY TO GET INTO THE
SPECIFICS REGARDING SEVERE CHANCES...BUT IF THE GFS VERIFIES
SEVERE WEATHER WOULD BE POSSIBLE.

HAMPSHIRE

[aggiecutter]

This interesting tidbit from the Tornado just east of Longview last week:

[Brent]

During the 2011 killer tornadoes in Alabama stuff like that from Tuscaloosa was found 150-200 miles away in Georgia. It was pretty ridiculous. Sadly not the same human result.

[Ntxw]

Low is spinning in W Texas still, maybe it will fill in tomorrow for all of us

Meanwhile rain is moving in to DFW

[Rgv20]

Flood Watch for tomorrow...interesting day coming up!

FLOOD WATCH
NATIONAL WEATHER SERVICE BROWNSVILLE TX
933 PM CDT MON APR 13 2015

...FLOODING THREAT RETURNS TO DEEP SOUTH TEXAS...

.A COLD FRONT NOW LOCATED OVER CENTRAL AND EASTERN TEXAS WILL
MOVE SOUTHEAST TOWARDS DEEP SOUTH TEXAS THROUGHOUT THE NIGHT AND
INTO TUESDAY. THIS COLD FRONT WILL INTERACT WITH MOIST AND
UNSTABLE AIR OVER THE REGION TO GENERATE SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS ACROSS MUCH OF DEEP SOUTH TEXAS ON
TUESDAY. ANY ADDITIONAL HEAVY RAINFALL THAT OCCURS ACROSS THE AREA
ON TUESDAY WILL LIKELY FALL OVER GROUND THAT HAS ALREADY BEEN
SATURATED FROM RECENT RAINS. THIS COULD QUICKLY RESULT IN
ADDITIONAL FLASH FLOODING TOMORROW.

TXZ248>257-141045-
/O.NEW.KBRO.FF.A.0004.150414T1200Z-150415T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ZAPATA-JIM HOGG-BROOKS-KENEDY-STARR-HIDALGO-INLAND WILLACY-
INLAND CAMERON-COASTAL WILLACY-COASTAL CAMERON-
INCLUDING THE CITIES OF...ZAPATA...HEBBRONVILLE...FALFURRIAS...
SARITA...RIO GRANDE CITY...ROMA...MCALLEN...EDINBURG...PHARR...
MISSION...WESLACO...RAYMONDVILLE...BROWNSVILLE...HARLINGEN...
PORT MANSFIELD...PORT ISABEL...SOUTH PADRE ISLAND...
LAGUNA HEIGHTS...LAGUNA VISTA
933 PM CDT MON APR 13 2015

...FLASH FLOOD WATCH IN EFFECT FROM 7 AM CDT TUESDAY THROUGH
TUESDAY EVENING...

THE NATIONAL WEATHER SERVICE IN BROWNSVILLE HAS ISSUED A

* FLASH FLOOD WATCH FOR A PORTION OF DEEP SOUTH TEXAS...
INCLUDING THE FOLLOWING AREAS...BROOKS...COASTAL CAMERON...
COASTAL WILLACY...HIDALGO...INLAND CAMERON...INLAND WILLACY...
JIM HOGG...KENEDY...STARR AND ZAPATA.

* FROM 7 AM CDT TUESDAY THROUGH TUESDAY EVENING

* AN ADDITIONAL 1 TO 2 INCHES OF RAINFALL WILL BE POSSIBLE ACROSS
MUCH OF DEEP SOUTH TEXAS ON TUESDAY WITH LOCALLY HIGHER AMOUNTS
POSSIBLY REACHING THE 2 TO 4 INCH RANGE.

* RAPID RUNOFF FROM ADDITIONAL HEAVY RAINFALL MAY RESULT IN FLASH
FLOODING ACROSS LOW LYING AREAS...CREEKS AND STREAMS...LOW WATER
CROSSINGS...AS WELL AS URBAN AREAS WITH POOR DRAINAGE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT FLASH FLOODING IS POSSIBLE DURING
THE NEXT 24 TO 36 HOURS. RESIDENTS LIVING IN FLOOD PRONE AREAS
SHOULD TAKE ACTION TO PROTECT PROPERTY.

&&

$$

SPEECE

[weatherdude1108]

Nice to see our friends to the north and friends to the south are getting beneficial rains (almost too much of a good thing at times it looks like). Meanwhile right in the middle where I am, a few sprinkles and mist, with some fog here and there. Logically you'd think the gaps in the rain would be filled from north to south. Are the activation boundary locations that precise?

I'm at a loss for words. I sympathize with dhweather's broken record and think I know how he feels.

But, he may be getting in on some of those nice rains up there now. Just waiting patiently for our turn. Ho hum.

[TeamPlayersBlue]

That rain just off the texas coast looks mean. Not even sure if i want that coming onshore. Looks like some of it will.

[Tireman4]

Well the HGX NWS spoke on that very thing....

DID A QUICK UPDATE TO RAISE POPS AT/ALONG THE COAST DUE TO CURRENT LINE
OF STORMS. NOT SURE HOW FAR INLAND THIS ACTIVITY WILL GO (A MAJORITY
OF IT COULD REMAIN OFFSHORE)...SO KEPT POPS IN A 50%-60% RANGE FOR
THOSE AREAS.

LOCALLY HEAVY RAINFALL (POTENTIAL FOR 3 TO 4 INCHES IN A SHORT PERIOD
OF TIME) COULD LEAD TO SOME FLOODING NEAR THE COAST. ALSO COULD SEE
SOME MARINE WIND GUSTS >34 KNOTS. 42

[gboudx]

Here's an update from jeff:

Next upstream impulse in the SW flow aloft resulting in strong/severe MCS over the coastal bend this morning producing torrential rainfall rates.

Well defined thunderstorm complex extends from CRP to near VCT and moving E to ESE with the main thrust of the weather along the coast from CRP to Rockport. Hourly rainfall rates nearing 3.5-4.0 inches per hour just north of CRP where cell mergers have occurred….flash flooding is ongoing. Recent radar trends over the upper TX coastal waters show an increase in convective development over the Gulf waters as lift from this impulse arrives into SE TX. Think the majority of the heavy rains will be along the coast and offshore with a larger area of light to moderate rainfall affecting inland areas south of I-10. North of I-10, low level inflow of moisture will be cut off by storms over the Gulf and not expecting much activity today.

Should be between disturbances on Wednesday before things turn very wet Thursday into Friday. A slow moving frontal boundary will slowly move into the area while another nearly stationary upper level low cuts off over the SW US leading to multiple disturbances moving across the region. Moisture levels will remain very high for mid April and storm motions will be gradually slowing suggesting the overall threat for sustained excessive rainfall will be increased Thursday and Friday. Hard to time which day or time period will be the most active as we have seen over the past few days mesoscale influences can wreak havoc with the forecast.

While the overall pattern will be favorable for heavy rainfall and even a few severe storms the details in the mesoscale environment will dictate when and where such events may occur on Thursday and Friday. Models are still not in good agreement on if the area with dry out over the weekend or remain wet.

[weatherdude1108]

Hampshire's afternoon discussion:

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
249 PM CDT TUE APR 14 2015

.SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...
SKIES REMAIN MOSTLY CLEAR TO MOSTLY CLOUDY ACROSS THE REGION WITH
THE CLEARING OCCURRING MAINLY OCCURRING ACROSS THE EDWARDS
PLATEAU AND RIO GRANDE PLAINS. TEMPERATURES TODAY HAVE REMAINED IN
THE 60S AND LOWER 70S WITH PERSISTENT WEAK COLD AIR ADVECTION WITH
THE CONTINUED NORTHERLY FLOW AND THE AFTERNOON CLOUD COVER. THE
FORECAST TONIGHT SHOULD REMAIN MOSTLY DRY. MODELS DO SHOW SOME
THETA-E ADVECTION ACROSS THE SOUTHERN AND WESTERN COUNTIES LATE
TONIGHT AS MOISTURE BEGINS TO SURGE NORTHWARD. MOISTURE AHEAD OF
THE LIFT IS NOT THE BEST AS WELL AS INSTABILITY LEVELS...HOWEVER
THE STRONG LIFT SHOULD WARRANT THE MENTION OF A 20 POP TONIGHT.
SOUTHERLY FLOW CONTINUES WEDNESDAY WITH CONTINUED LIFT ASSOCIATED
WITH WARM-AIR ADVECTION. STABILITY PROFILES WILL CONTINUE TO BE
THE CONCERN AS WEAK INHIBITION AND CAPE VALUES LESS THAN 1000 J/KG
SHOULD CONTINUE TO ONLY SUPPORT LOW POPS. HIGH TEMPERATURES
TOMORROW SHOULD BE BACK INTO THE 80S FOR MOST OF THE AREA WITH THE
CONTINUED WARM AIR ADVECTION.

FOR WEDNESDAY NIGHT...HIGH RES-MODELS SUCH AS THE TTU WRF CONTINUE
TO DEVELOP THUNDERSTORMS OFF OF THE SERRANIAS DEL BURRO MOUNTAINS
IN THE AFTERNOON HOURS BEFORE TRACKING THEM EAST OF THE RIO GRANDE
AFTER 00Z. DUE TO MODELS BEING FAIRLY CONSISTENT WITH THIS
OCCURRING WILL SHOW CHANCE POPS FOR THE RIO GRANDE COUNTIES AFTER
00Z. SHEAR AND INSTABILITY PROFILES WOULD SUPPORT THE CHANCE OF A
WEAKENING SEVERE THUNDERSTORM IN OUR CWA AND THIS THREAT IS
COVERED WELL BY THE DAY 2 MARGINAL RISK FROM SPC.

&&

.LONG TERM (THURSDAY THROUGH TUESDAY)...
THURSDAY BEGINS AN EVEN MORE ACTIVE PERIOD FOR SOUTH-CENTRAL TEXAS
WITH DECENT THUNDERSTORM CHANCES FOR THE AREA. BY THURSDAY...A
STRONG UPPER LEVEL LOW WILL BE SLOWLY APPROACHING THE AREA FROM
THE WEST. MODEL GUIDANCE CONTINUES TO HAVE A HARD TIME AGREEING ON
THE FORECASTED TRACK AND TIMING OF THIS SYSTEM. THEREFORE...THURSDAY
WILL BE THE HIGHEST CONFIDENCE DAY WITH CONFIDENCE DECREASING
EACH DAY THROUGH SUNDAY. AT THE SAME TIME THE UPPER LOW APPROACHES
ON THURSDAY...A SOUTHERN BRANCH JET STREAK WILL BE BEGINNING TO
ENTER SOUTH TEXAS. THIS PLACES OUR CWA IN THE LEFT EXIT REGION OF
THE UPPER JET FOR THURSDAY AFTERNOON. THIS WILL PROVIDE DYNAMICAL
LIFTING FOR CONVECTION IN COMBINATION WITH CONTINUED WEAK ASCENT
IN THE LOWER LEVELS ASSOCIATED WITH THE WARM AIR ADVECTION. WITH
THE DEEP LIFT IN PLACE...WE EXPECT A DECENT COVERAGE OF SHOWERS
AND THUNDERSTORMS. SEVERE CHANCES WILL DEPEND ON HOW MUCH WARMING
CAN OCCUR DURING THE DAY THURSDAY AS WE WILL BE DEALING WITH
WIDESPREAD CLOUD COVER. THE GFS WARMS US UP INTO THE UPPER 70S
WHICH WOULD EQUATE TO ABOUT 2500-3000 J/KG OF CAPE WHILE THE
NAM/ECMWF HAVE LOWER VALUES OF INSTABILITY. MID-LEVEL FLOW WILL
SUPPORT SHEAR VALUES AROUND 40 KNOTS AND ROTATING THUNDERSTORMS
WOULD BE POSSIBLE. WILL HAVE TO WATCH THIS CLOSELY BUT WOULDNT BE
SURPRISED TO SEE THE MARGINAL RISK ON DAY 3 BE UPGRADED TO SLIGHT
AT A LATER TIME IF THE INSTABILITY OF THE GFS COMES TO FRUITION.

MODELS THEN DIVERGE WITH THE HANDLING OF THE UPPER LEVEL LOW. THE
GFS REMAINS CONSISTENT WITH BEING MUCH MORE PROGRESSIVE WITH THE
PATTERN AND MOVES THE LOW EAST AND THEN SENDS A COLD FRONT INTO
THE REGION FRIDAY. THIS WOULD EQUATE TO CONTINUED RAIN CHANCES
FRIDAY BUT DRYING BEHIND THE FRONT FOR THE WEEKEND. ON THE OTHER
HAND...MODEL CONSENSUS FROM THE NAM/CANADIAN/ECMWF HANG UP THE
UPPER LOW AND HAVE CONTINUED RAIN CHANCES THROUGH SATURDAY NIGHT.
WILL CONTINUE TO SIDE WITH THE MODEL CONSENSUS AND HOLD RAIN
CHANCES THROUGH THE WEEKEND. IN ADDITION THE PATTERN AS OF LATE
WOULD SUPPORT A SLOWER SOLUTION. ALL GUIDANCE FINALLY MOVES THE
LOW AWAY FROM THE REGION BY SUNDAY LEAVING DRIER CONDITIONS IN
PLACE FOR THE REMAINDER OF THE FORECAST PERIOD.

HAMPSHIRE

[weatherdude1108]

Bob Rose speaks of the rain gaps. Please "pop the bubble."

Over the past few days, rain has been falling across most of Texas. Unfortunately, it hasn't been falling across the Hill Country and the Austin area. In a strange matter of chance, the recent storm systems have either moved too far to the north or too far to the south, leaving dry conditions in between.

http://www.lcra.org/water/river-and-wea ... ather.aspx

[Brent]

Has anyone looked at SVR potential Thu/Fri? A couple highly respected DFW mets have at least hinted at tornado potential

[gpsnowman]

Just watched a local TV weather report. Not totally backtracking on any severe weather for tomorrow but it seems to be shifting elsewhere. Man I smell a bust for good thunderstorms. Not a rain bust, but a disappearing chance for some powerful t-storms. I hope I am wrong. At least in my area, thunder and lightning have been heard and seen without rain whereas rain has been seen and heard without thunder and lightning. The three have never really made and appearance together for any length of time. Maybe once overnight but nothing to brag about. When does winter start?

[aggiecutter]

2 things: The driver of the truck was lucky he wasn't killed, and I didn't know it was common for a tornado to move to the northwest when it occludes.

EF-2 Tornado Between Winfield & Mount Pleasant--April 13, 2015

Overview
A mini-supercell quickly developed over Northeast Texas during the afternoon of April 13, 2015. This supercell produced a very brief, but significant EF-2 tornado in Titus County between Winfield and Mount Pleasant. A damage survey team from the National Weather Service office in Shreveport, LA, investigated the damage on April 14.

The tornado struck the Mid America Pet Food Plant just north of Interstate 30. Cars were tossed by the tornado, and several vehicles were damaged or destroyed. This brief, yet intense, tornado also lofted two large metal trash dumpsters. One dumpster was tossed nearly 150 yards and 40 feet high and was deposited on the top of a warehouse. A second dumpster hit the edge of another building 75 yards away and landed on top of a pickup truck parked below. The truck had just arrived within seconds of the tornado. The dumpster crushed the passenger side of the truck, but the driver, who was in the vehicle, was uninjured. Part of a warehouse was completely destroyed when the tornado's winds entered the open doors and lifted the roof.

The mini-supercell was moving northeast. However, the damage survey indicated that the tornado was actually moving northwest. This often happens when a tornado occludes.

[gboudx]

Update from jeff:

Very active weather period on tap for the region.

Severe Thunderstorms and flooding rainfall possible today-Saturday.

Large slow moving upper level storm system has moved into the SW US with the upper level jet stream becoming aligned over SE TX from SW to NE. At the surface a weak warm front is found over the nearshore waters and will be pushing inland today. Morning soundings from BRO and CRP showed impressive PWS values of 1.99 (BRO) and 1.66 (CRP) and SPC mesoanalysis shows and extensive area of tropical moisture from S TX across the western Gulf of Mexico shifting northward. Skies are broken across SE TX allowing some marginal surface heating to occur while water vapor images show an upstream disturbance over MX approaching the Rio Grande River. Air mass over SC TX is already unstable with most unstable CAPE of 2338 J/kg and forecasted values of over 3000 J/kg at CRP this afternoon. 0-6km shear values are near 40kts which will lead to storm organization and potentially some supercell structures.

Inland moving warm front coupled with approaching disturbance will result in a rapid increase in strong to severe thunderstorms early this afternoon across the region. Extremely heavy rainfall of 2-3 inches per hour along with large hail and damaging winds will be possible. Cannot rule out an isolated tornado near the coastal counties where low level shear values are the highest and we may see some enhancement near the inland moving warm front.

Friday:
Much more significant weather day appears likely on Friday with the potential for round 2 to really impact the region.

Factors appear to be coming together for a fairly widespread severe weather threat on Friday as a very strong upper level disturbance ejects out of MX during peak heating forming a large forward propagating MCS/bow echo. Downstream air mass over SE TX becomes very unstable Friday afternoon with lift increasing. SPC forecasters are concerned that a large MCS with significant bowing/wind damage threat may develop in the late afternoon and evening hours from SC TX into SE TX. High resolution models are suggesting a severe MCS will affect the region with potential for widespread wind damage. While low level inflow looks marginal the unstable air mass and likely strong downdraft potential may result in wind damage along the leading gust front. A few very strong gusts (+70mph) will be possible.

Flood Threat:
Upstream air mass over S TX and the western Gulf is extremely moist with PWS approaching 2.0 inches which is near climo maximums for mid April. This will support excessive rainfall rates across the region under the strongest storms. Starting to get a little worried about the potential for HP supercell formation along the warm frontal boundary as these cells tend to move slower than the background shallower cells and can be prodigious short term rainfall producers. Grounds are already wet from well above normal rainfall of late and heavy rainfall will only generate additional run-off. Flash flooding within urban areas will certainly be possible under the heavy rainfall cores along with rises on area watersheds.

Weekend:
Additional storms will be possible Saturday and possibly Sunday. Main focus right now is today and especially Friday.