May 2016: Shower/Storm Chances To End May

[Katdaddy]

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
211 PM CDT FRI MAY 13 2016

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
SOUTHWESTERN BRAZORIA COUNTY IN SOUTHEASTERN TEXAS...

* UNTIL 300 PM CDT

* AT 210 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR BRAZORIA...OR
7 MILES SOUTHEAST OF SWEENY...AND IS NEARLY STATIONARY.

HAZARD...60 MPH WIND GUSTS AND QUARTER SIZE HAIL.

SOURCE...RADAR INDICATED.

IMPACT...HAIL DAMAGE TO VEHICLES IS EXPECTED. EXPECT WIND DAMAGE
TO ROOFS...SIDING...AND TREES.

* LOCATIONS IMPACTED INCLUDE...
LAKE JACKSON...ANGLETON...NORTHWESTERN FREEPORT...CLUTE...WEST
COLUMBIA...SWEENY...RICHWOOD...BRAZORIA...JONES CREEK...OYSTER CREEK...
HOLIDAY LAKES...BAILEY`S PRAIRIE AND WILD PEACH VILLAGE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

PREPARE IMMEDIATELY FOR LARGE HAIL AND DEADLY CLOUD TO GROUND
LIGHTNING. SEEK SHELTER INSIDE A WELL-BUILT STRUCTURE. STAY AWAY FROM
WINDOWS.

LARGE HAIL AND DAMAGING WINDS AND CONTINUOUS CLOUD TO GROUND
LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS IMMEDIATELY.
LIGHTNING IS ONE OF NATURE`S LEADING KILLERS. REMEMBER...IF YOU CAN
HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY LIGHTNING.

[srainhoutx]

Quick 12Z Global guidance update regarding Sunday into late next week. QPF amounts continue to increase and the various models schemes suggest a pesky frontal boundary will linger over the area at least into next Friday. The very long range outlook via the various computer guidance suggest little if any change in the unsettled pattern extending way out to the Memorial Day Holiday period.

[Katdaddy]

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
307 PM CDT FRI MAY 13 2016

TXZ237-238-132045-
GALVESTON TX-BRAZORIA TX-
307 PM CDT FRI MAY 13 2016

...STRONG THUNDERSTORMS ACROSS WEST CENTRAL GALVESTON AND
NORTHEASTERN BRAZORIA COUNTIES THROUGH 345 PM CDT...

AT 307 PM CDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM OVER
DANBURY...OR 8 MILES NORTHEAST OF ANGLETON...MOVING EAST AT 15 MPH.

NICKEL SIZE HAIL AND WINDS IN EXCESS OF 30 MPH WILL BE POSSIBLE WITH
THIS STORM.

LOCATIONS IMPACTED INCLUDE...
SOUTHWESTERN LEAGUE CITY...SOUTHWESTERN FRIENDSWOOD...ALVIN...SANTA FE...
HITCHCOCK...DANBURY...HILLCREST...LIVERPOOL...BONNEY AND CHOCOLATE BAYOU.

[srainhoutx]

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
441 PM CDT FRI MAY 13 2016

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
NORTHWESTERN GALVESTON COUNTY IN SOUTHEASTERN TEXAS...
NORTH CENTRAL BRAZORIA COUNTY IN SOUTHEASTERN TEXAS...
SOUTH CENTRAL HARRIS COUNTY IN SOUTHEASTERN TEXAS...

* UNTIL 515 PM CDT

* AT 441 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED OVER EASTERN
PEARLAND...MOVING NORTHEAST AT 5 MPH.

HAZARD...QUARTER SIZE HAIL.

SOURCE...RADAR INDICATED.

IMPACT...DAMAGE TO VEHICLES IS EXPECTED.

* LOCATIONS IMPACTED INCLUDE...
PEARLAND...NORTHERN FRIENDSWOOD...GREATER HOBBY AREA...WESTERN SOUTH
BELT / ELLINGTON...BROOKSIDE VILLAGE...MINNETEX AND HOBBY AIRPORT

[srainhoutx]

FLOOD ADVISORY
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
440 PM CDT FRI MAY 13 2016

GALVESTON TX-BRAZORIA TX-HARRIS TX-FORT BEND TX-
440 PM CDT FRI MAY 13 2016

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* FLOOD ADVISORY FOR...
WESTERN GALVESTON COUNTY IN SOUTHEASTERN TEXAS...
NORTH CENTRAL BRAZORIA COUNTY IN SOUTHEASTERN TEXAS...
SOUTH CENTRAL HARRIS COUNTY IN SOUTHEASTERN TEXAS...
EAST CENTRAL FORT BEND COUNTY IN SOUTHEASTERN TEXAS...

* UNTIL 645 PM CDT

* AT 438 PM CDT...DOPPLER RADAR INDICATED A SLOW MOVING CLUSTER OF
STRONG THUNDERSTORMS IN THE AREA. RAINFALL RATES UP TO NEAR 3
INCHES PER HOUR ARE BEING REPORTED. RAINFALL THIS HEAVY CAN RUNOFF
TO PRODUCE STREET FLOODING.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
PEARLAND...LEAGUE CITY...SOUTHEASTERN MISSOURI CITY...FRIENDSWOOD...
ALVIN...MANVEL...GREATER HOBBY AREA...FRESNO...WESTERN SOUTH BELT /
ELLINGTON...ARCOLA...BROOKSIDE VILLAGE...IOWA COLONY...MINNETEX...HOBBY
AIRPORT...SIENNA PLANTATION...SOUTH ACRES / CRESTMONT PARK AND
JULIFF.

[srainhoutx]

FLOOD ADVISORY
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
541 PM CDT FRI MAY 13 2016

HARRIS TX-
541 PM CDT FRI MAY 13 2016

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* FLOOD ADVISORY FOR...
HARRIS COUNTY IN SOUTHEASTERN TEXAS...

* UNTIL 745 PM CDT

* AT 540 PM CDT...DOPPLER RADAR INDICATED A CLUSTER OF THUNDERSTORMS
ACROSS THE REGION. RAIN RATES IN SOME THE THESE CELLS ARE
APPROACHING 3 INCHES PER HOUR. RAINFALL THIS HEAVY WILL QUICKLY
RUNOFF TO CAUSE SOME MINOR STREET FLOODING IN THE ADVISORY AREA.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
PASADENA...NORTHWESTERN BAYTOWN...DEER PARK...SOUTH HOUSTON...GALENA
PARK...JACINTO CITY...GREATER FIFTH WARD...FOURTH WARD...SECOND WARD...
GREATER EASTWOOD...GREATER GREENSPOINT...DOWNTOWN HOUSTON...GREATER
HEIGHTS...NEAR NORTHSIDE HOUSTON...CHANNELVIEW...NORTHSIDE /
NORTHLINE...ALDINE...HIGHLANDS...MIDTOWN HOUSTON AND CLOVERLEAF.

[srainhoutx]

Cluster of strong to severe thunderstorms have developed along and behind the seabreeze this afternoon. Lots of reports of pea to marble size hail and 1 inch per hour rainfall rates with heavier storms. To the West, a convective complex has developed over the Sierra Madre Mountains and storms are firing further North along an advancing cold front across the Panhandle and Oklahoma.

[unome]

sure got busy fast - no rain here, but the breeze felt good !

https://weather.im/iembot/

[srainhoutx]

Slow moving frontal boundary continues to drop South across Texas early this morning and is expected to become stationary somewhere across the SE Texas area tonight. Thunderstorm development is to organize with daytime heating along the seabreeze and outflow boundaries collide with the slow moving frontal boundary this afternoon.

It appears a couple of upper air disturbance will approach from the West beginning Sunday night into Monday with another stronger shortwave nearing the area Wednesday into Thursday. The stalled boundary appears to linger throughout the coming work week with multiple rounds of heavier showers and thunderstorms as moisture levels increase further mid next week to around 2+ inches. The Weather Prediction Center has outlined a Slight Risk for Excessive Rainfall for today for portions of Central and SE Texas and for SE Texas into Louisiana for Monday. Will need to monitor for the potential of Flash Flood Watches being hoisted in the days ahead as the quantitative precipitation forecast continue to advertise a potential for heavy rainfall. Still at lol of uncertainty exactly where and when the heaviest rainfall will occur, so continue to monitor the future updates throughout the weekend into early next week.

05142016 Day 1 ER slight 94ewbg_sm.jpg (49.08 KiB) Viewed 3281 times

[srainhoutx]

Saturday morning briefing from Jeff:

***Active weather pattern next several days***

***Severe Thunderstorms and flooding rainfall possible***

Discussion:
Upper air pattern remains a stormy one for TX…looking very similar to May 2015 with large scale troughing over the SE US and a moist unstable air mass over TX which results in round after round of thunderstorms. This is a very dangerous pattern with respect to flash flooding potential especially given the saturated conditions and full rivers/lakes. Upper level trough over the SW US will help supply numerous disturbances across TX while short waves passing in the northern jet along the Canadian border bring weak fronts to stall over the region. Air mass is generally uncapped with little to no upper level ridging aloft (another similar feature to 2015).

Today:
Air mass is already moist and unstable and will only require modest heating into the mid 80’s to get things going. Seabreeze will advance inland while a weak front drifts southward. Hi-res models show the tow features colliding during peak heating over SE TX…and boom. Expect fairly extensive development of thunderstorms…some severe. Generally in these situations the storms develop along the boundary collision and then drift toward the S or SW across the region. Air mass become very unstable and expect a severe threat this afternoon and evening with large hail being the primary threat although damaging winds can’t be ruled out.

Storms should have more organization than the last few days which raises the concern for heavy rainfall as motions will remain slow. Easily could see 1-2 inches per hour with PWS of 1.5-1.8 inches over the region. Main concern is larger areas seeing higher rainfall rates compared to the isolated nature the last few days.

Could easily see 1-2 inches of rainfall with isolated amounts of 3-4 inches

Late Sunday-Monday:

***Very active period with heavy rainfall***

Strong short wave approaches from the west and with the frontal boundary still stalled over the region expect widespread thunderstorms. Severe threat may not be as high with this event as this afternoon given the time of day (overnight into Monday when instability is at a minimum). Heavy rainfall appears to be the main threat with cell training in a very moist air mass. Still not sure how this will play out, but the drier GFS has trended toward the wet CMC and ECMWF leading to more confidence in higher rainfall totals.

Will hit the entire area with a solid 1-2 inches with isolated totals of 3-5 inches possible. May need to go higher if confidence increases that any well organized thunderstorm complex slows over the region.

Tuesday-Friday:

Unsettled pattern remains with another strong short wave approaching in the Wednesday/Thursday period. Frontal boundary remains stalled on top of the region and expect additional widespread thunderstorms with both severe and heavy rainfall potential.

Hydro:

TX is not in a good position to accept additional heavy rainfall with rivers high, lakes full, and grounds saturated. Widespread high QPF over the next 5-7 days is deeply concerning given the conditions in place. Trend has also been to increase rainfall amounts and the expected upper air pattern and moisture levels point toward the potential for some significant or even extreme rainfall events across the state. This is certainly the type of pattern that can produce a foot of rainfall in a short period of time resulting in devastating flash flooding and much of the state is at risk over the next 7 days.

7_day Forecasted Rainfall Amounts:

[srainhoutx]

MESOSCALE PRECIPITATION DISCUSSION 0207
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
151 PM EDT SAT MAY 14 2016

AREAS AFFECTED...CENTRAL/SOUTH TEXAS

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 141751Z - 142151Z

SUMMARY...ISOLATED FLASH FLOOD THREAT WITH STRONG STATIONARY CELLS
WITH RATES.

DISCUSSION...A WEAK COLD FRONT MOVING SOUTH BISECTS CENTRAL TX
FROM S OF JSO TO HLR OUT TO NEAR FST. AN EARLY MORNING CONVECTIVE
COMPLEX ORIGINATING OUT OF REAL/EDWARDS COUNTY PROVIDES ADDITIONAL
BOUNDARIES TO FOCUS LOCALIZED MST CONVERGENCE. GOES-14 SRSO AND
RADAR MOSAIC INDICATE THE ACTIVATION OF THE CONVECTION
ALONG/BETWEEN THE BOUNDARIES ALONG THE THETA-E AXIS WHICH IS
GENERALLY COINCIDENT WITH A ZONE OF TPW THAT IS AT 1.5" OR GREATER
(POOLED BEST ALONG THE RIO GRANDE WITH VALUES UP TO 2.0").
MLCAPES OF 1500-2000 J/KG IS AVAILABLE FOR ENERGETIC UPDRAFTS. A
POTENTIAL LIMITING FACTOR IS FLOW IS GENERALLY WEAK IN THE LOW
LEVELS BUT THIS ALSO SUPPORTS STATIONARY CELL MOTION TO ALLOW FOR
CELLS TO RAPIDLY PRODUCE RATES UP TO 2.0"/HR. ABOVE THE STEERING
LAYER...UPPER LEVEL FLOW IS FAIRLY GOOD WITH 40-50 KTS OBSERVED TO
PROVIDE GOOD EVACUATION FOR THE UPDRAFTS. THIS SETUP HAS THE
POTENTIAL TO SETUP ENOUGH INFLOW FROM THE UPDRAFTS TO KEEP
UPDRAFT/DOWNDRAFTS SEPARATED ENOUGH FOR SOME ISOLATED AREAS TO
LEAD TO TOTALS IN EXCESS OF 3"...NEARING FF VALUES...AS WAS THE
CASE THIS MORNING IN REAL/EDWARDS COUNTY. MORE LIKELY CELLS WILL
PROPAGATE SLOWLY SOUTH PARTICULARLY FURTHER EAST ALONG THE COLD
FRONT WHERE COLD POOLS REINFORCED BY THE FRONT WILL BE SUFFICE TO
ACTIVATE NEW CELLS.

FURTHER SOUTHWEST...MATURE MCS/COLLIDING OUTFLOW BOUNDARIES WILL
PROVIDE SIMILAR SHORT-TERM HIGH RATE THREAT PARTICULARLY IN CELL
MERGERS...WITH RATES UP TO 3"/HR GIVEN THE HIGHER MOISTURE
AVAILABILITY.

GALLINA

ATTN...WFO...CRP...EWX...FWD...HGX...SHV...SJT...

[srainhoutx]

FLOOD ADVISORY
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
134 PM CDT SAT MAY 14 2016

TRAVIS TX-WILLIAMSON TX-
134 PM CDT SAT MAY 14 2016

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* FLOOD ADVISORY FOR...
NORTHERN TRAVIS COUNTY IN SOUTH CENTRAL TEXAS...
WILLIAMSON COUNTY IN SOUTH CENTRAL TEXAS...

* UNTIL 430 PM CDT

* AT 131 PM CDT...DOPPLER RADAR INDICATED HEAVY RAIN DUE TO
THUNDERSTORMS. THIS WILL CAUSE MINOR FLOODING IN THE ADVISORY AREA.
UP TO TWO INCHES OF RAIN HAVE ALREADY FALLEN WITH ANOTHER 1 TO 2
INCHES EXPECTED. WILLIAMSON COUNTY SHERIFFS OFFICE HAS REPORTED
SOME MINOR FLOODING ALONG I-35 IN THE JARRELL AREA.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
AUSTIN...ROUND ROCK...CEDAR PARK...GEORGETOWN...PFLUGERVILLE...TAYLOR...
GRANGER...SERENADA...WINDEMERE...ANDERSON MILL...LEANDER...HUTTO...LAGO
VISTA...BARTLETT...FLORENCE...JARRELL...LIBERTY HILL...WEIR...GEORGETOWN
DAM AND ANDICE.

[srainhoutx]

Will need to watch to our West for a potential developing meso low organizing just to the S and SW of San Antonio generally moving East. The weak cold frontal boundary is slooowy sagging South across the Austin Metro Area where 2 inch per half hour rainfall rates are being reported in Williamson County. The seabreeze boundary is slowly advancing North and any boundary collisions could lead to rapidly developing possibly severe thunderstorms capable of producing large hail, damaging winds and very heavy rainfall rates. The 12Z Global guidance ALL paint a very unsettled pattern next week with a pesky frontal boundary stalled near or just South of the I-10 Corridor and some suggestion of a Coastal trough/low attempting to develop mid to late next week into the weekend.

[unome]

pretty good cell in NW Harris Co, can hear some small hail also

[srainhoutx]

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
234 PM CDT SAT MAY 14 2016

TXZ195-197-142015-
BURLESON TX-WASHINGTON TX-
234 PM CDT SAT MAY 14 2016

...STRONG THUNDERSTORMS ACROSS SOUTHEASTERN BURLESON AND CENTRAL
WASHINGTON COUNTIES THROUGH 315 PM CDT...

AT 233 PM CDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM
NEAR BURTON...OR 16 MILES NORTHWEST OF BRENHAM NEAR LAKE SOMERVILLE.
THIS STORM WAS NEARLY STATIONARY.

HALF INCH HAIL AND WINDS IN EXCESS OF 30 MPH WILL BE POSSIBLE WITH
THIS STORM.

LOCATIONS IMPACTED INCLUDE...
BRENHAM...SOMERVILLE...BURTON...LAKE SOMERVILLE DAM...QUARRY...LYONS AND
INDEPENDENCE.

[Rip76]

Starting to fire up in the Sagemont/Pearland area.
(A little closer to 45.)

[srainhoutx]

Pea sized hailed reported with that NW Harris County cell off Huffmiester near Cypress.

[unome]

Pea sized hailed reported with that NW Harris County cell off Huffmiester near Cypress.

yup, pretty good lightning also http://www.met.tamu.edu/ciams/lma/index.html

[srainhoutx]

1/2 inch hail reported in Clear Lake

[Katdaddy]

Storms firing across SE TX currently.