August 2015 - Isolated Rain Chances to End August

[txflagwaver]

Literally dark as night here in Clear Lake at 8:10am...crazy!

[mckinne63]

Literally dark as night here in Clear Lake at 8:10am...crazy!

Same over here in the Galleria area

[Heat Miser]

Literally dark as night here in Clear Lake at 8:10am...crazy!

Same in Friendswood. And the rumble grows closer. Round two this morning.

[ticka1]

Thursday morning email from Jeff Lindner:

Increasing showers and thunderstorms producing heavy rainfall along and south of US 59 at current time.

Radar shows bands of slow moving thunderstorms extending from Chambers County to Fort Bend County with storm motions to the ENE over Galveston Bay and northward over Fort Bend County. Rainfall rates under these storms have been impressive with radar showing 1-2 hour totals of 2-4 inches in some areas.

Such tropical air masses like to focus their excessive rainfall close to the coast and this appears to be the case this morning. Expect development across Harris County in the short term as outflow boundaries push northward from the south….especially southern Harris County. Air mass should become worked over by early afternoon with gradual weakening activity.

Short term rainfall totals this morning and yesterday have been upwards of 2-3 inches with isolated amounts of 4-4.5 inches. While grounds are dry and can handle several inches of rainfall, the short term intensities will be enough to cause street flooding and that will be the main threat with storms this morning.

Jeff Lindner

[ticka1]

Downtown on the 19th floor - it is black as night outside and continuous thunder and lightning for the last hour. Wonder what the rainfall amounts are?

[Katdaddy]

Yep. Dark as night in downtown Houston. Flash Flood Warning issued for Galveston County.

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
826 AM CDT THU AUG 20 2015

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
GALVESTON COUNTY IN SOUTHEASTERN TEXAS...

* UNTIL 1030 AM CDT

* AT 822 AM CDT...DOPPLER RADAR INDICATED THUNDERSTORMS STRETCHING
FROM FRIENDSWOOD TO TIKI ISLAND...GENERALLY ALONG THE INTERSTATE
45 CORRIDOR. UP TO 6 INCHES OF RAIN HAS FALLEN SO FAR NEAR TIKI
ISLAND...AND WITH RAINFALL RATES CONTINUING BETWEEN 3 AND 4 INCHES
PER HOUR...FLASH FLOODING IS EXPECTED TO BEGIN SHORTLY IF IT HAS
NOT ALREADY. DO NOT DRIVE ACROSS FLOODED ROADS.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
EASTERN LEAGUE CITY...TEXAS CITY...DICKINSON...LA MARQUE...SANTA
FE...HITCHCOCK...KEMAH...BAYOU VISTA...CLEAR LAKE SHORES...TIKI
ISLAND...BACLIFF AND SAN LEON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO HIGHER GROUND NOW. ACT QUICKLY TO PROTECT YOUR LIFE.

[ticka1]

From the experts - how long are these storms going to last today?

[srainhoutx]

MESOSCALE PRECIPITATION DISCUSSION 0458
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
712 AM EDT THU AUG 20 2015

AREAS AFFECTED...SOUTHEAST TX & VICINITY

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

VALID 201110Z - 201510Z

SUMMARY...STORMS ACROSS THE UPPER TX COAST SHOULD HAVE HOURLY RAIN
RATES UP TO 2.5", WHICH COULD LEAD TO FLASH FLOODING.

DISCUSSION...THUNDERSTORMS WITH HEAVY RAINFALL ARE DEVELOPING
BETWEEN GALVESTON AND PORT ARTHUR. THESE ARE ELEVATED NORTH OF AN
OUTFLOW BOUNDARY, WHICH HAS A WAVE SOUTH OF GALVESTON. INFLOW AT
850 HPA IS ABOUT 20 KTS OUT OF THE SOUTH-SOUTHWEST, SLIGHTLY
EXCEEDING THE MEAN 850-400 HPA WIND. MUCAPES UPSTREAM NEAR THE
MIDDLE TX COAST ARE IMPRESSIVE, WITH VALUES OF 3000-6000 J/KG.
PRECIPITABLE WATER VALUES OF 2.1-2.2" ARE REPORTED VIA GPS.

THE 06Z SSEO NEIGHBORHOOD PROBABILITIES SUGGEST THE PEAK OF THE
HEAVY RAIN EVENT WILL BE IN THE 12-15Z TIME FRAME. SINCE THIS IS
EARLY MORNING ACTIVITY, BELIEVE THE THREAT WILL BE CONSTRAINED TO
THE COASTAL TWO TIERS OF COUNTIES/PARISHES OF SOUTHEAST TX AND FAR
SOUTHWEST LA, AND CONFINED THE THREAT TO PLACES TO THE NORTHEAST
OF THE DIVERGENCE FORECAST AT 850 HPA NEAR THE MIDDLE TX COAST.
AFTER 15Z, INFLOW AT 850 HPA INTO THE REGION WEAKENS, WHICH SHOULD
REDUCE THE BROADER FLASH FLOOD THREAT. OUTSIDE OF THE 09Z HRRR,
THE CAM GUIDANCE APPEARS TO HAVE A HANDLE ON THIS ACTIVITY.
MESOSCALE QPF GUIDANCE ADVERTISES LOCAL AMOUNTS OF 4-7" IN AND
NEAR THIS AREA, WHICH WOULD EXCEED FLASH FLOOD GUIDANCE, EVEN
OUTSIDE OF THE HOUSTON METROPOLITAN AREA. HOURLY RAIN RATES UP TO
2.5" ARE POSSIBLE, WHICH SHOULD ALLOW THE RAIN TO FALL QUICKLY.
USED THE POSSIBLE CATEGORY HERE, SINCE SOME OF THE AREA INCLUDED
IS SWAMPLAND.

ROTH

ATTN...WFO...HGX...LCH...

[srainhoutx]

A bit worrisome to see a stalled boundary draped across Texas with storms firing along the frontal boundary to the N as well as additional moisture streaming in from the Eastern Pacific across Mexico. That typically spells trouble regarding the Flash Flood potential across SE Texas. Looks like an active day or two with deep rich tropical moisture streaming N off the Gulf. PW's are very high above 2+ inches suggesting very heavy rainfall rates are possible and could continue into Friday.

MESOSCALE PRECIPITATION DISCUSSION 0459
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
746 AM EDT THU AUG 20 2015

AREAS AFFECTED......SOUTH TEXAS...

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

VALID 201145Z - 201545Z

SUMMARY...HIGHLY EFFICIENT WARM RAIN PROCESSES WILL LEAD TO
CONTINUED INTENSE SHORT TERM RAINFALL RATES ACROSS THE RIO GRAND
VALLEY THIS MORNING.

DISCUSSION...THE MCS EARLIER THIS MORNING IS CURRENTLY RECYCLING
ACROSS THE RIO GRAND VALLEY...WITH THE NEW ORGANIZED CONVECTION
AIDED BY CONTINUED LOW LEVEL INFLOW AROUND 30 KTS WITH MUCAPES OF
2000 J/KG. DEEP WARM RAIN PROCESSES ARE IN PLAY WITH OBSERVED
PRECIPITABLE WATER VALUES AROUND 2.25 INCHES PER THE GPS...ALONG
WITH VERY HIGH WET BULB ZERO HEIGHTS (OVER 14,000 KFT) AND WARM
CLOUD DEPTHS OVER 10,000 FEET.

THE MESOSCALE-ENHANCED VORT CENTER CURRENTLY OVER SOUTH TEXAS PER
THE LATEST WV LOOPS WILL MOVE VERY LITTLE THIS MORNING PER THE
LATEST MODEL GUIDANCE. THIS ALONG WITH THE CONTINUED SUFFICIENT
LOW LEVEL INFLOW ABOVE THE SURFACE LAYER WILL MAINTAIN ORGANIZED
MULTICELLULAR CONVECTION...AT LEAST THROUGH LATE MORNING BEFORE
DIURNAL/DIFFERENTIAL HEATING WILL BEGIN TO DISRUPT THE CURRENT
ORGANIZED LOW LEVEL MOIST INFLOW.

ADDITIONAL BACK-BUILDING AND THUS CELL TRAINING ARE EXPECTED WITH
THE STATIONARY MCV AND STRONG LOW LEVEL INFLOW RELATIVE TO THE
MEAN 850-300 LAYER FLOW. BASED ON THIS ALONG WITH THE DEGREE/
DEPTH OF MOISTURE AND INSTABILITY...HOURLY RAINFALL RATES OF 2-2.5
INCHES ARE ANTICIPATED UNDER THE HEAVIER CORES... WITH SOME OF THE
LATEST CAM GUIDANCE (INCLUDING THE EXPERIMENTAL
HRRR...WRF-ARW...AND WRF-NMMB) INDICATING POCKETS OF 3-6" THROUGH
15Z.

HURLEY

[ticka1]

Srainhoutx - GO and ENJOY the island!

[srainhoutx]

Srainhoutx - GO and ENJOY the island!

Having my morning coffee. Remember it's 4:15AM here and it's showery/breezy right now. I will enjoy my helicopter tour of Oahu early this afternoon and then dinner with the Hurricane Hunter crew that just left California for Pearl Harbor that will be investigating the tropical system to my SSE beginning tomorrow.

[Katdaddy]

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
856 AM CDT THU AUG 20 2015

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
NORTHEASTERN BRAZORIA COUNTY IN SOUTHEASTERN TEXAS...
NORTHWESTERN GALVESTON COUNTY IN SOUTHEASTERN TEXAS...
SOUTHEASTERN HARRIS COUNTY IN SOUTHEASTERN TEXAS...

* UNTIL 1100 AM CDT

* AT 853 AM CDT...DOPPLER RADAR INDICATED A PERSISTENT AREA OF
THUNDERSTORMS IN THE WARNED AREA WITH RATES AS HIGH AS 3 TO 4
INCHES PER HOUR AT SOME LOCATIONS. PORTIONS OF SOUTHEAST HARRIS
COUNTY HAVE ALREADY RECEIVED OVER 3 INCHES OF RAIN AND ADDITIONAL
HEAVY RAIN OF THIS MAGNITUDE WILL CREATE FLASH FLOODING. DO NOT
DRIVE ACROSS WATER COVERED ROADS.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
PASADENA...PEARLAND...LEAGUE CITY...FRIENDSWOOD...LA PORTE...DEER
PARK...ALVIN...SOUTH HOUSTON...SEABROOK...WEBSTER...MANVEL...CLEAR
LAKE...SOUTH BELT / ELLINGTON...GREATER HOBBY AREA...NASSAU BAY...
TAYLOR LAKE VILLAGE...EL LAGO...BROOKSIDE VILLAGE...SHOREACRES AND
CLEAR LAKE SHORES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO HIGHER GROUND NOW. ACT QUICKLY TO PROTECT YOUR LIFE.

[jasons2k]

FLOOD WATCH
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
921 AM CDT THU AUG 20 2015

TXZ178-179-199-200-210>214-226-227-235>238-202100-
/O.NEW.KHGX.FF.A.0015.150820T1421Z-150820T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
AUSTIN-BRAZORIA-CHAMBERS-COLORADO-FORT BEND-GALVESTON-HARRIS-
JACKSON-LIBERTY-MATAGORDA-MONTGOMERY-POLK-SAN JACINTO-WALLER-
WHARTON-
INCLUDING THE CITIES OF...ALVIN...ANAHUAC...ANGLETON...BAY CITY...
BELLVILLE...BROOKSHIRE...CLEVELAND...COLDSPRING...COLUMBUS...
CONROE...CORRIGAN...DAYTON...EAGLE LAKE...EDNA...EL CAMPO...
FREEPORT...FRIENDSWOOD...GALVESTON...HEMPSTEAD...HOUSTON...
HUMBLE...KATY...LAKE JACKSON...LEAGUE CITY...LIBERTY...
LIVINGSTON...MISSOURI CITY...MONT BELVIEU...ONALASKA...PALACIOS...
PASADENA...PEARLAND...PIERCE...PRAIRIE VIEW...RICHMOND...
ROSENBERG...SEALY...SHEPHERD...SUGAR LAND...TEXAS CITY...
THE WOODLANDS...TOMBALL...WEIMAR...WHARTON...WILLIS...WINNIE
921 AM CDT THU AUG 20 2015

...FLASH FLOOD WATCH IN EFFECT UNTIL 4 PM CDT THIS AFTERNOON...

THE NATIONAL WEATHER SERVICE IN HOUSTON/GALVESTON HAS ISSUED A

* FLASH FLOOD WATCH FOR A PORTION OF SOUTHEAST TEXAS...INCLUDING
THE FOLLOWING AUSTIN...BRAZORIA...CHAMBERS...COLORADO...
FORT ...BEND...GALVESTON...HARRIS...JACKSON...LIBERTY...
MATAGORDA...MONTGOMERY...POLK...SAN JACINTO...WALLER AND
WHARTON.

* UNTIL 4 PM CDT THIS AFTERNOON

* A COMBINATION OF DEEP GULF MOISTURE...A WEAK FRONTAL BOUNDARY
AND AN UPPER LEVEL DISTURBANCE WILL ALLOW SHOWERS AND
THUNDERSTORMS TO PERSIST INTO THE AFTERNOON HOURS. DUE TO
CLUSTERING AND MERGING CELLS...LOCALIZED EXCESSIVE RAINFALL
AMOUNTS ARE EXPECTED. SO FAR THIS MORNING SOME SPOTS HAVE SEEN 4
TO 7 INCHES OF RAIN. AS CELLS TRAIN OVER THESE SAME LOCATIONS
AND PRODUCE RAINFALL RATES BETWEEN 2 AND 4 INCHES PER
HOUR...FLASH FLOODING WILL BE LIKELY. NOT EVERYONE WILL IN THE
WATCH AREA SEE THESE EXCESSIVE AMOUNTS...HOWEVER THE THREAT
WILL BE IN PLACE THROUGH THE AFTERNOON HOURS...ESPECIALLY CLOSER
TO THE COAST.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.

[ronyan]

4.57" of rain this morning in Lake Jackson, getting deluged. This is easily the most rain in a day that we've seen all year. Now coming down at 4 in/hr rate.

[unome]

busy morning for Texas

http://origin.wpc.ncep.noaa.gov/archive ... e=20150820

[Texaspirate11]

7 inches of rain in my rain gauge by the bay!

[BlueJay]

Our rain gauge says 1.14 inches so far today.
Excellent.

[Cromagnum]

My rain gauge only measured just shy of 0.6 inches for the whole rain event today. Combined with the 0.25 inch I got 2-3 days ago, that gives me less than 1 inch of rain at my house since late June. What do I have to do to get it to rain in Rosharon ?

[BlueJay]

Do a rain dance, Cromagnum?
Hopefully, y'all will get some real rain soon.

[Cromagnum]

Hopefully we get our share today. You can clearly see the anti-rain halo in my area yesterday.