Texas Spring 2016

[Ntxw]

Couple of storms popped up south of Waco surging north along with a warm front. They'll arrive at DFW 12-1am should they hold together. Currently lightning and small hail with them.

[jasons2k]

GFS and Euro are a little different, but the Euro is pretty concerning. A pretty wide band of 7"+ rains from NC/NE Harris County, up through Central Montgomery County, and then arcing NE into San Jacinto County and extreme SE Walker County.

I'm a bit surprised Liberty County isn't in the FF watch with the models still wobbling around a bit. They seem to always get dumped on, and the Trinity River is prone to flooding too.

[EnnisTx]

Is it just me or is that storm near Moody rotating??

[Annie Oakley]

USGS launches real-time flood monitoring website

"AUSTIN - Following the recent flooding across Central Texas, the U.S. Geological Survey launched a new web-based program to give users real-time information about water levels, forecasts and emergency situations across the state.

The idea for the program, called the "USGS Texas Water Dashboard," came when team member and USGS Data and Spacial Studies Chief Daniel Pearson lost power during the 2015 Memorial Day floods."

http://www.kvue.com/news/local/usgs-lau ... /158768523


http://txpub.usgs.gov/txwaterdashboard/index.html

[Annie Oakley]

https://twitter.com/USGS_TexasFlood

https://twitter.com/USGS_TexasRain


More info and help here:
https://www.usgs.gov/news/flood-prepare ... 80%99s-app

[Texas Snowman]

Larry Cosgrove this morning on Facebook: "Final call on developing severe weather + flooding rainfall threat for the south central U.S. during the next 48 hours.

Satellite view shows subtropical jet stream interacting with storm organizing over the southern/central High Plains. This is roughly the same set-up that caused the debacle in the Houston TX metro a week ago. What is different is that the current system is far more expansive, and organized.

I see two very critical threat zones for supercells with hail and tornadoes. One initiation point is the Interstate 35 corridor between San Antonio and Austin. The other is western and central Oklahoma. These two focal areas may tend to merge somewhat by this evening. So if you live in the DFW Metroplex, be assured that risks for severe weather are present until probably midnight.

Now could we achieve another blast-out MCS in Texas? As you can see, this disturbance has already cooked up a thunderstorm grouping in OK and AR. The near term model prediction really want to smack SE TX again, starting around 10PM and lasting until just after daybreak. After that the grouping of convection rips into AR and LA. Even as far north as the St. Louis MO metro, there will be a threat for severe weather.

So if you are out chasing the storms, head for Chickasha OK and Buna TX. Those should be the two best watch points for initiation for tornado threats within 20 miles of start-up. And if you live within a bracket from Bastrop TX....Waco TX....Livingston TX....Jasper TX....Baytown TX....Alvin TX, get set for some rough times before the storms exit around dawn.

And I should mention...more thunderstorms in Texas Sunday and Monday from the "hang back" energy in the Southwest. After that, the next serious threat for the south central states is around May 10.

Have a great weekend everyone "

[Texas Snowman]

Steve McCauley on Facebook: "Strong to severe thunderstorms will easily fire up across north Texas today with all severe weather modes possible: hail, high winds, and tornadoes. Since the cap is weak and our upper-air disturbance once again coming in negative tilt, storms will not have to wait until late in the day to fire, but they will be at their strongest in the afternoon and lingering into this evening.

Fridays are my L-O-N-G days at school, so make sure you follow the WFAA team for updates throughout the day regarding this event !"

[Texas Snowman]

@henrymargusity -- Using the subtropical jet rule, tornadic storms will occur in south Texas on the northern edge of the jet.

[cheezyWXguy]

With my amateur eyes, I see number of remnant outflow boundaries traversing the eastern part of the state on visible satellite. Will be very interesting to see what effect they have on tornado potential this afternoon...

[ATCcane]

"So if you are out chasing the storms, head for Chickasha OK and Buna TX. Those should be the two best watch points for initiation for tornado threats within 20 miles of start-up. And if you live within a bracket from Bastrop TX....Waco TX....Livingston TX....Jasper TX....Baytown TX....Alvin TX, get set for some rough times before the storms exit around dawn"

So did Larry really mean Buna or did he mean to type Buda ? There is a Buna, Tx but it's in extreme east Texas and it'd be hard to see anything in those tall pines....

[Texas Snowman]

Buda I'm pretty sure. He mentioned the area between Austin and San Antonio.

[Tireman4]

Could get bumpy here in the holler late this afternoon into tonight....


389
FXUS64 KHGX 290939
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
439 AM CDT FRI APR 29 2016

.DISCUSSION...
TODAY:
FAIRLY UNEVENTFUL MORNING ANTICIPATED. AN AREA OF DEEP TROPICAL
MOISTURE (PW`S 2-2.2") SITUATED IN THE SW GULF WILL BE MAKING ITS
WAY UP THE COAST AND INTO SE TX DURING THE LATE MORNING AND
AFTERNOON HOURS. BY EARLY AFTERNOON...THERE`S PRETTY GOOD
AGREEMENT IN GUIDANCE SHOWING SHOWERS/STORMS BEING INITIATED ALONG
DRYLINE IN CNTL TEXAS AND MAKING THEIR WAY EASTWARD INTO SE TX
DURING THE LATE AFTERNOON AND EVENING HOURS. SHOULD BE ENOUGH
INSTABILITY & SHEAR BY THAT TIME FOR SOME SEVERE STORMS TO BE A
THREAT (HAIL, WIND, ISO TORNADOES ALL A POSSIBILITY). FLASH
FLOODING IS ALSO A CONCERN IN ASSOCIATION WITH CONVECTIVE CELLS.
THE MORE FAVORED LOCATION FOR THIS TO OCCUR APPEARS TO GENERALLY
BE NORTHWEST OF HIGHWAY 59.

THIS EVENING INTO SATURDAY MORNING:
THIS IS WHERE CONSIDERABLE UNCERTAINTY ENTERS THE PICTURE ON HOW
THINGS WILL EVOLVE. BEST CASE SCENARIO WILL BE FOR THE
LINE/COMPLEX OF STRONG TO SEVERE STORMS TO CONTINUE MOVING ESE
ACROSS THE REMAINDER OF THE REGION WITH A BREAK IN THE PRECIP IN
ITS WAKE. WORST CASE SCENARIO...WHICH CANNOT BE RULED OUT
EITHER...IS FOR THE THE NORTH-TO-SOUTH ORIENTED PORTION OF THE
LINE OF STORMS TO RACE EASTWARD LEAVING THE SOUTHERN PORTION OF
THE LINE BEHIND AS IT TRANSITIONS INTO A MORE WEST-TO-EAST
ORIENTATION SOMEWHERE ACROSS THE AREA. SHOULD THIS OCCUR...IT`LL
BECOME SITUATED ROUGHLY PARALLEL TO THE UPPER FLOW AND MOVEMENT
COULD SUBSTANTIALLY SLOW. FAVORABLE UPPER LEVEL DIVERGENCE
OVERHEAD INTO MIDDAY SATURDAY WITH SUSTAINED MODERATE INFLOW
FEEDING PERPENDICULAR TO SUCH A BOUNDARY COULD LEAD TO A
SIGNIFICANT FF THREAT WHEREVER SUCH A BOUNDARY ENDS UP.
AGAIN...THAT WOULD BE A WORST CASE SITUATION. ANYTHING IN BETWEEN
IS POSSIBLE. UNFORTUNATELY...MANY TIMES THESE EVENTS PLAY OUT ON
SMALLER SCALE DETAILS THAN WHAT MODELS DEPICT...SO OVERALL
CONFIDENCE IN ANY ONE SOLUTION ISN`T VERY HIGH AND WILL HAVE TO
KEEP AN EYE ON TRENDS. BOTTOM LINE IS GROUND IS NEARLY SATURATED
FROM RECENT RAINS. EVEN 35-50 MPH WINDS WILL BE A RISK OF DOWNING
TREES. STRONGER CELLS WILL ALSO PRODUCE EFFICIENT RAINFALL RATES.
QUICK RUNOFF WILL PRODUCE A FF THREAT. WILL LEAVE FF WATCH AS/IS.

REST OF SATURDAY & SUNDAY:
WILL BE HIGHLY DEPENDENT WHERE POTENTIAL BOUNDARIES ARE SITUATED & WILL
HAVE TO SEE WHAT EVOLVES TONIGHT. A COOL FRONT IS FORECAST TO BEGIN
PUSHING INTO SE TX LATE SATURDAY. SUSPECT EVEN IF THERE IS A BREAK
IN THE ACTION DURING THE DAY IT`LL RECOVER ENOUGH FOR AT LEAST
SCT PRECIP TO REDEVELOP ALONG AND SOUTH OF THE FRONT SATURDAY
NIGHT & SUNDAY.

MONDAY THRU TUESDAY MORNING:
ANOTHER SERIES OF UPPER IMPULSES MOVES INTO THE REGION FROM THE
WESTERN TROF. EXPECT PRECIP TO BECOME WIDESPREAD ONCE AGAIN.
FRONTAL BOUNDARY WILL BE LINGERING NEARBY AND PROBABLY SERVE AS A
CONTINUED FOCUS FOR PRECIPITATION. POTENTIAL FOR SOME MORE
UNNEEDED HEAVY RAINS WILL CONTINUE TO BE MONITORED.

WEDNESDAY THRU FRIDAY:
THINGS SHOULD BEGIN TO DRY OUT AS UPPER RIDGE GRADUALLY BUILDS
OVERHEAD. 47

&&

.MARINE...
GENERALLY MODERATE ONSHORE WINDS EXPECTED TODAY IN RESPONSE TO THE
STORM SYSTEM DEVELOPING OVER THE SRN PLAINS. WINDS SET TO INCREASE
BY TONIGHT AS THE SYSTEM BEGINS MOVING EAST AND HELPS TO DRAW DIS-
TURBANCES OVER THE AREA FROM THE WSW. HAVE KEPT CAUTION FLAGS POS-
TED IN PLACE THROUGH THIS AFTN...AND SHOULD BE UPGRADED TO A SMALL
CRAFT ADVISORY (ESPECIALLY FOR THE COASTAL WATERS) BY THIS EVENING.
WINDS/SEAS COULD BE FURTHER ELEVATED IN/NEAR SCT STORMS TODAY INTO
TONIGHT.

HAVE ALSO HOISTED A COASTAL FLOOD ADVISORY FOR TODAY FOR BEACHES/
INTERCOASTAL WATERWAY DOWN THE BRAZORIA COUNTY COASTLINE. ONSHORE
WINDS HAVE HELP TO PILE UP WATER ONTO ROADWAYS/LOW-LYING AREAS IN
THESE AREAS DURING HIGH TIDE...ESPECIALLY CLOSE TO THE HIGHWAY 87
AND 124 CONNECTION NEAR THE BOLIVAR PENINSULA. 41

&&

.AVIATION...
STRONG WAA HAS PRODUCED SOME WIDELY SCT -DZ/-RA OVER SE TX OVERNIGHT
ALONG WITH IFR TO MVFR CONDITIONS. WE SHOULD SEE CIGS LIFT SOME THRU
THE LATE MORNING/EARLY AFTN HOURS AS THE DEEP ONSHORE WINDS PERSIST.
WE COULD SEE VFR CONDITIONS DURING THE AFTN WITH VCSH...BUT INCREAS-
ED PCPN CHCS TONIGHT SHOULD HELP TO LOWER CIGS. TIMING OF THE STORMS
TONIGHT WILL BE THE MAIN ISSUE SO WILL LIKELY KEEP WITH VCTS WORDING
FOR NOW. 41

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 85 72 83 69 83 / 70 80 60 30 30
HOUSTON (IAH) 84 73 82 70 84 / 50 70 70 50 50
GALVESTON (GLS) 80 76 80 74 80 / 30 50 60 60 40

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH FROM 1 PM CDT THIS AFTERNOON THROUGH SUNDAY
MORNING FOR THE FOLLOWING ZONES: AUSTIN...BRAZOS...
BURLESON...COLORADO...FORT BEND...GRIMES...HARRIS...
HOUSTON...MADISON...MONTGOMERY...POLK...SAN JACINTO...
TRINITY...WALKER...WALLER...WASHINGTON...WHARTON.

COASTAL FLOOD ADVISORY FROM 9 AM THIS MORNING TO 4 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: BRAZORIA...CHAMBERS...
GALVESTON.

GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 6 AM CDT EARLY THIS
MORNING FOR THE FOLLOWING ZONES: GALVESTON BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.

&&

$$

DISCUSSION...99

[Tireman4]

From Jeff:

Friday morning briefing from Jeff:


***Significant rainfall and flash flood event possible over SE TX this afternoon-early Saturday***

Discussion

An upper level storm system over the SW US is currently spreading lift across W TX. A very impressive pool of moisture over the western Gulf of Mexico (PWS 2.0-2.2 inches…record levels) is heading NNW toward the TX coast and will arrive later this morning. Upper level winds will gradually become divergent this afternoon and weak disturbances will approach from the SW. With a little heating the local air mass will be primed.

Expect a line of strong to severe storms to develop along the dry line over C TX early this afternoon and move eastward into SE TX by mid afternoon. Additionally, some of the meso scale models show development in a S to N or SSW to NNE line from Brazoria County into Harris County…not sure what the focus of this development is, but since a couple of the models show this activity…it certainly could happen.

Big concern is late this afternoon into the overnight hours as central TX line arrives into the region. Looks like the northern end of the line will move across our northern set of counties, but southern tail end slows and unfortunately becomes parallel to the upper level flow. Expect the outflow boundary to become oriented WSW to ENE over some part of the region and the flash flood threat will really go up with good potential for training convection. Tremendous Gulf inflow will be maintained into this boundary all night which will allow storms to be maintained. This is a highly classis overnight flash flood setup for SE TX.

Moisture levels near mid summer and at tropical like levels is very concerning. Expect intense rainfall rates in any stronger storms of 2-4 inches per hour. These kind of rainfall rates are very damaging for this area and will get areas into trouble very quickly….especially with the saturated grounds in place. Such rainfall rates over urban areas will cause rapid run-off and flooding.

Widespread rainfall amounts of 2-4 inches look likely with isolated amounts of 5-8 inches. Could see even higher totals if the storms train for an extended period of time. Will favor areas along and NW of US 59 (or areas so hard hit two weeks ago) for the highest rainfall totals…but there is still plenty of uncertainty as to where these maximum amounts will fall.

Severe:

There will certainly be a severe threat with all the instability and shear in place. Main threats will be wind damage…especially in any bowing segments and large hail. With extremely wet grounds…it will not take much wind to blow down trees…so even non-severe thunderstorms may produce damage. Think the highest severe threat will be from Huntsville SSW to near Victoria this afternoon with the overall threat lessening eastward tonight as the event transitions toward a heavy rainfall event.

Saturday-Tuesday:

Weak front will stall somewhere over the area with continued chances for additional rounds of thunderstorms. May get a break on Saturday if the air mass becomes worked over enough tonight…if not…thunderstorms will just continue to develop.

Next period of interest will be late Sunday-early Tuesday when the next strong disturbance comes out of Mexico and across TX. Looks like another heavy rainfall threat especially along the coast during this period.

Hydro:

Watersheds across the area are well above base flow and many rivers, while below flood stage, remain swollen. With saturated grounds and full lakes and rivers…there is just no place for the water to go. Expect rises on all watersheds and some will likely go into flood due to the rainfall over the next 24-48 hours. Residents along rivers, creeks, and bayous should remain alert to the threat for rapidly rising water and be prepared to act.

As a reminder…never drive into high water…of the 8 fatalities associated with the Tax Day Flood…all 8 were vehicle related. Remember…Turn Around Don’t Drown”

[Brent]

Latest from FWD, raised the tornado threat:

[1900hurricane]

I'm actually somewhat surprised to see FWD go as bullish as they are with the tornado threat. It has me somewhat interested in what the next SPC Convective Outlook is going to look like, since they often coordinate that stuff with the local offices.

Also, geez, the HRRR looks like it's trying to seriously skunk someone in southeast Texas once again, although the exact spot keeps varying.

[TarrantWx]

FWD continues to hit tornado potential pretty hard. If it truly comes to fruition today I hope people are paying attention and not blowing it off because of Tuesday. If it doesn't come to fruition, I worry about how the public will perceive the NWS credibility. As weather enthusiasts, we understand how only a few small changes in the atmosphere can make a significant difference in the weather conditions, both when it comes to winter weather events and severe weather events. But the layperson doesn't understand that and only perceives the forecast as "crying wolf".

[Tireman4]

Rut Roh.........





AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1047 AM CDT FRI APR 29 2016

.DISCUSSION... QUICK UPDATE. CAP STILL HOLDING AS OF 10 AM BUT STORMS RAPIDLY DEVELOPING JUST TO THE NORTHEAST OF THE AREA. CU DEVELOPMENT INTO THE NORTHERN COUNTIES MAY BE THE PRECURSOR TO THIS AREA OF DEVELOPMENT EVENTUALLY WORKING BACK DOWN INTO THE CWA AS CAP ERODES THIS AFTERNOON. FORECAST CHANGES INCLUDE LOWERING OF POPS SOUTH WHERE STRONGLY CAPPED AND ADDED HAZY. ACROSS THE NORTH AND WEST FOR THIS AFTERNOON AM EXPECTING RAPID TO EXPLOSIVE DEVELOPMENT BY MID AFTERNOON AND WITH STRONG LOW LEVEL SHEAR AND ABUNDANT INSTABILITY (AWAY FROM THE CAP) WILL HAVE THREATS RANGING FROM TORNADO-WIND-HAIL THREAT IN THE WEST TO HAIL-WIND IN THE NORTHWEST. THIS EVENING THIS WILL SHIFT INTO THE AREA AND FOR WHAT IT IS WORTH THE 12Z NAM PAINTS A GRUESOME PICTURE OF A DANGEROUS SEVERE WEATHER THREAT ACROSS AREAS FROM COLUMBUS TO HUNTSVILLE NORTHWARD. VERY HIGH LOCALIZED HELICITY IN AN ENVIRONMENT OF HIGH INSTABILITY. HEAVY RAINFALL THREAT STILL HIGH AND LATEST HRRR/NAM INDICATING THE WESTERN CWA EARLY THIS EVENING THEN SHIFTING EASTWARD INTO THE REMAINDER OF THE CWA. RAISED POPS NORTH THIS AFTERNOON AND FOR THE HIGHWAY 59 CORRIDOR THIS EVENING AND OVERNIGHT.

[Ellsey]

Why would people think NWS cried wolf? There were tornadoes on Tuesday, and they did do damage to homes and businesses.

[gboudx]

I don't like being in that red shaded area.

This was under the pic that TarrantWx posted.

At 11:30 am we are seeing several ingredients come together that would result in rotating thunderstorms and possibly tornadoes. The two main ingredients are wind shear (which is often caused by surface winds that are more easterly) and instability (which is caused by sunshine and high humidity). These black lines which show the direction the surface winds are coming from, and you can see near the warm front they are more easterly. Meanwhile the whole area is very humid, but the satellite is showing the sun coming out in many locations. The greatest risk for storm rotation and tornadoes will be where there is the highest combination of instability and wind shear or where the red shaded area is. It is too soon to tell whether a storm will be able to form a tornado until after they develop, but the ingredients that storms need to produce tornadoes are there.

[TarrantWx]

Why would people think NWS cried wolf? There were tornadoes on Tuesday, and they did do damage to homes and businesses.

Yes, there was damage in Grayson county. But people tend to only be focused on their local area. For folks in DFW, Tuesday was most likely perceived as crying wolf. They don't understand, or care, about the complexities in forecasting weather. They only care what happens to them. I've seen many comments on Facebook about people questioning the NWS about "crying wolf again" which is what prompted me to start the discussion.