May 2015 Record Setting May Rainfall Totals For Region

[jasons2k]

Interesting that Eric Berger's post circled the coastal areas for a potential severe weather threat. The latest MCD from the SPC has the north central area circled instead...

[jasons2k]

Looks like the cells are continuing to build more and more out ahead of the main line as we get a bit of heating...quickly approaching the area now

[srainhoutx]

NWS Houston/Galveston will be extending Flood Watch until 1:00AM CDT Thursday morning.

[srainhoutx]

From Nesdis:

SATELLITE PRECIPITATION ESTIMATES..DATE/TIME 05/13/15 2006Z
SATELLITE ANALYSIS BRANCH/NESDIS---NPPU---TEL.301-683-1404
LATEST DATA USED: GOES-13 1945Z HANNA
.
LOCATION...TEXAS...
.
ATTN WFOS...LCH...SHV...HGX...FWD...
ATTN RFCS...LMRFC...WGRFC...
.
EVENT...SATELLITE FEATURES FOR LOCALIZED HEAVY RAIN EVENT
.
SATELLITE ANALYSIS AND TRENDS...OVER THE LAST FEW HOURS CONVECTION HAS
BEGUN TO DEVELOP WITHIN MODERATELY UNSTABLE ENVIRONMENT ON THE LEADING
EDGE OF MID LEVEL FORCING FROM LIFTING SHORTWAVE TROF EXTENDING FROM
PORTIONS OF E NM INTO N MEXICO. CONVECTION APPEARS TO BE DEVELOPING
WITHIN CONFLUENT LOW LEVEL WIND FIELD POSSIBLY AIDED BY DIFFERENTIAL
HEATING BOUNDARY ALONG THE LEADING EDGE OF DEEPER CLOUD FIELD ON VIS
IMAGERY. ALTHOUGH SHORTWAVE TROF WAS BECOMING MORE PROGRESSIVE, PROFILES
OVER THE REGION ARE MOSTLY UNIDIRECTIONAL WITH WEAK CORFIDI VECTORS,
WEAK THETA-E DIFFERENTIALS AND LOW LEVEL LAPSE RATES. THIS SHOULD TEND
TO PROMOTE AT A MINIMUM A PERIOD OF TRAINING CONVECTION POSSIBLE OVER
THE NEXT FEW HOURS FOR PORTIONS OF E AND SE TX. MOISTURE WAS QUITE
ANOMALOUS ON BLENDED PW ANALYSIS AND AREA GPS WITH VALUES RANGING FROM
1.70-1.90" OVER THE REGION AND THIS COMBINED WITH DEEP ABOVE 0C LAYER
AND MINIMAL CLOUD LAYER SHEAR SHOULD ALLOW FOR LOCALIZED RAINFALL RATES
OF 1.0-2.0"/HR IN ANY AREAS OF SUSTAINED TRAINING.

[srainhoutx]

MESOSCALE PRECIPITATION DISCUSSION 0083
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
314 PM EDT WED MAY 13 2015

AREAS AFFECTED...SOUTH TEXAS

CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY

VALID 131910Z - 140000Z

SUMMARY...ADDITIONAL CLUSTERS OF HEAVY SHOWERS AND THUNDERSTORMS
WILL PERSIST INTO THE EARLY EVENING HOURS.

DISCUSSION...THE LATEST WV/GOES-RGB IMAGERY INDICATES A
WELL-DEFINED AND SHARP UPPER TROUGH CROSSING THE RIO GRANDE VALLEY
EARLY THIS AFTERNOON AND THIS ENERGY WILL BE LIFTING NORTHEAST
THROUGH THE EVENING HOURS ACROSS THE SOUTHERN PLAINS. STRONG
FORCING/UPPER LEVEL DIVERGENCE COUPLED WITH A MOIST AND A
PERSISTENT S/SE LOW LEVEL JET SHOULD HELP TO GENERALLY SUSTAIN A
LARGE AREA OF SLOW-MOVING CONVECTION ALREADY IMPACTING PORTIONS OF
SOUTH TEXAS.

THE CONVECTION IS HELPING TO GENERATE A WELL-DEFINED COLD POOL
OVER PORTIONS OF THE TEXAS HILL COUNTRY...BUT WITH A LARGE POOL OF
MODERATE INSTABILITY CONTINUING TO FEED IN OFF THE WESTERN GULF OF
MEXICO AND UP THE LOWER RIO GRANDE VALLEY...CONVECTION NEAR THE
COLD POOL AND UP ALONG A STATIONARY FRONT IS EXPECTED TO CONTINUE
TO REGENERATE. THE STRONGER DYNAMICS ALOFT ASSOCIATED WITH THE
TROUGH ALOFT SHOULD BEGIN TO LIFT AWAY BY 00Z...AND SO THE
CONVECTION MAY TEND TO WANE IN ORGANIZATION BY THAT TIME.

THE 12Z ARW AND LATEST HRRR SUPPORT ADDITIONAL RAINFALL AMOUNTS OF
2 TO 4 INCHES WITH LOCALLY HEAVIER AMOUNTS THROUGH 00Z. GIVEN VERY
HEAVY RAINS OF LATE...SOIL CONDITIONS ARE EXPECTED TO BE SATURATED
AND SO ANY ADDITIONAL HEAVY RAINS SHOULD RESULT IN ADDITIONAL
FLASH FLOODING CONCERNS. WILL CONTINUE TO MONITOR.

ORRISON

ATTN...WFO...CRP...EWX...FWD...HGX...

[srainhoutx]

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
324 PM CDT WED MAY 13 2015

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
SOUTHEASTERN BURLESON COUNTY IN SOUTHEASTERN TEXAS...
EASTERN WASHINGTON COUNTY IN SOUTHEASTERN TEXAS...
SOUTHWESTERN WALKER COUNTY IN SOUTHEASTERN TEXAS...
SOUTHEASTERN BRAZOS COUNTY IN SOUTHEASTERN TEXAS...
NORTHERN WALLER COUNTY IN SOUTHEASTERN TEXAS...
NORTHWESTERN MONTGOMERY COUNTY IN SOUTHEASTERN TEXAS...
GRIMES COUNTY IN SOUTHEASTERN TEXAS...

* UNTIL 515 PM CDT

* AT 322 PM CDT...DOPPLER RADAR INDICATED A THUNDERSTORM PRODUCING
HEAVY RAIN ACROSS THE WARNED AREA MAINLY OVER GRIMES COUNTY. FLASH
FLOODING IS EXPECTED TO BEGIN SHORTLY. THUNDERSTORMS ARE PRODUCING
1 TO 2 INCHES OF RAINFALL AN HOUR.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
COLLEGE STATION...BRENHAM...NAVASOTA...PINEHURST...WASHINGTON...
MAGNOLIA...MONTGOMERY...MILLICAN...ANDERSON...TODD MISSION...
WELLBORN...DOBBIN...RICHARDS...DACUS...PLANTERSVILLE...CARLOS...
ROANS PRAIRIE AND INDEPENDENCE.

[srainhoutx]

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
335 PM CDT WED MAY 13 2015

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* TORNADO WARNING FOR...
SOUTHWESTERN WHARTON COUNTY IN SOUTHEASTERN TEXAS...
NORTHEASTERN JACKSON COUNTY IN SOUTH CENTRAL TEXAS...

* UNTIL 400 PM CDT

* AT 333 PM CDT...THE PUBLIC AND TRAINED WEATHER SPOTTERS REPORTED A
FUNNEL CLOUD OVER LAKE TEXANA NEAR GANADO...OR 7 MILES NORTHEAST
OF EDNA. A TORNADO MAY DEVELOP AT ANY TIME. DOPPLER RADAR SHOWED
THIS DANGEROUS STORM MOVING NORTH AT 20 MPH.

* LOCATIONS IMPACTED INCLUDE...
EDNA...GANADO AND CORDELE.

[jasons2k]

Another update from Jeff @ 3:40 PM

Flash Flood Watch has been extended until 100am Thursday.

Band of heavy rainfall continues to slowly approach from the west with rainfall now falling across the areas hit hard on Monday over Grimes, Waller, Montgomery, and Walker Counties. Numerous cells have begun to develop ahead of the main line with some cell training noted. Some concern with the very slow cell motions being noted over NW Wharton County…we do not want to get back into these slow moving stationary cell again…but the radar suggest this may be starting to happen which greatly increases the potential for small scale yet extreme rainfall totals. Thus far the storms do not appear overly organized..but this could change quickly.

Main emphasis this afternoon and evening will be heavy rainfall across the Houston urban areas during rush hour resulting in potential life safety concerns with vehicles and high water.

[srainhoutx]

The afternoon Update from the Weather Prediction Center expands the Slight Risk for Excessive Rainfall east for all of SE Texas and introduces a Moderate Risk across portions of SE Texas into the evening and overnight hours.

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
500 PM EDT WED MAY 13 2015

...VALID 21Z WED MAY 13 2015 - 12Z THU MAY 14 2015...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
20 SSW MMNL 20 SSW MMPG 20 N DRT 40 N JCT BWD 20 NW 05F TPL
25 NNW LHB 25 SSW CRS AFW 10 NW ADM 30 SSE OKM DEQ 10 ESE BAD
15 W POE 15 WSW BPT 10 W PSX 10 SSW CRP 20 S HBV 20 SSW MMNL.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
10 ENE 11R 40 NW UTS 15 E PSN 20 N OCH 30 E LFK 45 E CXO
10 NNE IAH 10 WSW DWH 10 ENE 11R.


...SRN AND ERN TX INTO ADJACENT SE OK AND THE ARKLATEX...

LOCAL UPGRADE TO MODERATE RISK IN SE TX. GREATEST SHORT TERM
CONCERN WILL BE SE TX IN THE AREA ROUGHLY BETWEEN COLLEGE
STATION...NACOGDOCHES...JASPER...AND HOUSTON. THIS IS WHERE A
NARROW WEDGE OF MODERATELY UNSTABLE AIR AND ROUGHLY 25 KNOT 850 MB
INFLOW REMAINED SANDWICHED BETWEEN THE SHARP LEAD SHORTWAVE TO THE
WEST AND REMNANT COLD POOL TO THE EAST. WITH INDIVIDUAL CELLS
TRACKING SLOWLY NNW AND THE ONGOING LOOSELY ORGANIZED MCS TRACKING
EAST AT ONLY 10 KNOTS...ONE HOUR RAINFALL WILL CONTINUE TO TOP 1.5
INCHES LOCALLY. MODELS ARE FAIRLY UNIFORM IN SUGGESTING THE EVENT
WILL DISSIPATE DURING THE EVENING AS THE SHORTWAVE LIFTS TOWARD
THE NORTHEAST AND WINDS IN THE 700-500 MB LAYER VEER. CONTINUED
SOUTHERLY INFLOW AT LOWER LEVELS...HOWEVER...MAY SUSTAIN SCATTERED
CELLS AT LEAST UNTIL A SHORT TIME AFTER DARK.

...EXTREME SCNTRL KS SWD THRU CNTRL OK..CNTRL AND SRN TX...

SYNOPTIC ASCENT WILL FOCUS OVER EASTERN AND ESPECIALLY
SOUTHEASTERN KS IN THE 00-09Z TIME FRAME. SOME OF THE HI-RES
MODELS...SUCH AS THE 12Z WRF-ARW AND NSSL WRF DO INDICATE AN AXIS
OF HEAVY RAINFALL ON THE ORDER OF 1.25 INCHES WITH EMBEDDED TOTALS
ABOVE 1.5 INCHES IN A NARROW SWATH. PLAN VIEW CAPE FORECASTS FROM
MULTIPLE SOURCES...HOWEVER...INDICATE LITTLE OR NO APPRECIABLE
INSTABILITY UNTIL AFTER THE BETTER FORCING SUBSIDES AND WINDS GAIN
A MORE WESTERLY COMPONENT ALOFT. GIVEN THE NEAR COMPLETE ABSENCE
OF INSTABILITY AND ANTECEDENT CONDITIONS NOT BEING ESPECIALLY WET
ACROSS KANSAS...WHERE THE MODEL SIGNAL EXISTS FOR SOME HEAVY
RAINFALL...THE ODDS OF EXCEEDING FLASH FLOOD GUIDANCE APPEAR TO BE
LESS THAN 5 PERCENT.


...SD...
MODELS DVLP AN AREA OF WEAK INSTABILITY ALONG SLOW NWD MOVING WARM
FRONT EXTENDING NEWD FROM WRN SD INTO ERN ND THIS PD AS WARM SLY
FLOW AND INCREASING MSTR FROM THE SOUTH FEED INTO THE BNDRY. UPR
JET LIFTING NWD ACRS THE FRONTAL ZONE IS EXPECTED TO PROVIDE
IMPROVING BROAD SCALE LIFT BY LATE WED INTO WED NIGHT. GLOBAL
MODELS WERE REASONABLY CLOSE WITH RAINFALL AMOUNTS HERE WITH THE
EXCEPTION OF THE 12Z CANADIAN WHICH WAS MUCH FARTHER N AND
HEAVIER...BUT IT TOO HAS COME INTO BETTER AGREEMENT FOR .25 TO .50
INCH PLUS AMOUNTS FROM WRN SD NEWD INTO NW MN. WHILE THESE
AMOUNTS WOULD NOT NORMALLY SUPPORT ORGANIZED FLASH FLOODING...WITH
NEAR SATURATED SOIL CONDS EXISTING ACRS MUCH OF WRN SD CAN NOT
RULE OUT ISOLD RUNOFF ISSUES FROM LOCALIZED HEAVIER CONVECTIVE
STORMS WHICH COULD PRODUCE SOME HOURLY RAINFALL AMOUNTS AROUND AN
INCH OR SO.

BURKE/TERRY

[srainhoutx]

Update from Jeff:

West Fork of the San Jacinto River:

The river is currently at 48.88ft (Bankfull 49.30 ft). This river has risen slightly faster than expected today and will likely rise overbanks this evening. Residents along the river should be prepared for overbanks conditions and potential flooding of roadways along the river and in low areas near the river. Some areas could become cut-off before sunrise on Thursday morning. The river is expected to crest near 50.3 ft Friday, but additional rainfall this evening may alter this forecast.

[srainhoutx]

FLOOD ADVISORY
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
539 PM CDT WED MAY 13 2015

LIBERTY TX-POLK TX-HARRIS TX-SAN JACINTO TX-MONTGOMERY TX-
539 PM CDT WED MAY 13 2015

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* FLOOD ADVISORY FOR...
WESTERN LIBERTY COUNTY IN SOUTHEASTERN TEXAS...
POLK COUNTY IN SOUTHEASTERN TEXAS...
NORTHEASTERN HARRIS COUNTY IN SOUTHEASTERN TEXAS...
SOUTHEASTERN SAN JACINTO COUNTY IN SOUTHEASTERN TEXAS...
SOUTHEASTERN MONTGOMERY COUNTY IN SOUTHEASTERN TEXAS...

* UNTIL 745 PM CDT

* AT 538 PM CDT...DOPPLER RADAR INDICATED HEAVY RAIN DUE TO
THUNDERSTORMS. THIS WILL CAUSE MINOR FLOODING IN THE ADVISORY
AREA. STORMS ARE CAUSING A HALF INCH TO AT MOST 1 INCH AN HOUR
RAIN RATES.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
CLEVELAND...DAYTON...LIVINGSTON...KINGWOOD...SHEPHERD...
SPLENDORA...CORRIGAN...PATTON VILLAGE...ROMAN FOREST...
WOODBRANCH...COLDSPRING...PLUM GROVE...KENEFICK...GOODRICH...NORTH
CLEVELAND...SEVEN OAKS...ALABAMA-COUSHATTA RESERVATION...WEST
LIVINGSTON...PORTER HEIGHTS AND LAKE LIVINGSTON STATE PARK.

ADDITIONAL RAINFALL OF 1 TO 2 INCHES IS EXPECTED OVER THE AREA. THIS
ADDITIONAL RAIN WILL MAKE MINOR FLOODING.

[jasons2k]

Sure is quiet in here. Meanwhile, the San Jacinto watershed is getting pounded, especially closer to Galveston Bay.

Only .12" here all day.

[Kbaldo84]

Its nice and quiet here in Seabrook as well. Only .55 inches of rain this evening. Last night at the plant I work at we had dumpsters floating around in the plant cause of how flooded it was. I don't think I have ever seen it rain that much down here without it being caused by a hurricane.

[srainhoutx]

The overnight guidance continues to advertise the same basic synoptic pattern of a Ridge over Florida and a Western upper trough throughout the weekend into early next week. The airmass remains somewhat unstable, but no real upper shortwave disturbances upstream suggest heat of the day thunderstorm chances with high precipitation rates are possible again today.

Rain chances increase tomorrow as a potent upper cold core low organizes to our West near California and begins its trek eastward. It appears another severe weather episode is ahead for the weekend across the Great Plains with storms developing across West Central Texas along the dryline and marching east. Showers and thunderstorms may increase Monday as a frontal boundary nears the Region, but some uncertainty remains in the timing. Any storms that do develop over the next 72 hours or so are capable of producing 2 inch per hour rainfall rates, so the flooding potential is still present across the Lone Star State.

[unome]

nice improvement for north TX: http://droughtmonitor.unl.edu/

http://droughtmonitor.unl.edu/MapsAndDa ... eMaps.aspx

[srainhoutx]

The short range meso guidance is beginning to latch on to the next upper shortwave disturbance crossing Mexico tomorrow suggesting an increase in showers and thunderstorm activity across portions of Central and SE Texas. Expect instability and lift to increase as this feature nears the area and possibly some stronger storms across N Texas as well. As always, the computer models have and will likely to struggle with this pesky pattern, so expect day to day changes as we move toward a more active weekend weather wise across our Region.

[srainhoutx]

Morning briefing from Jeff:

A little drier today as weak ridging aloft attempts to build over the region…but the break looks short.

Air mass remains very moist and unstable across the region and surface heating will result in this air mass becoming more unstable by mid to late morning into the early afternoon hours. No real focus for thunderstorms to develop on today with lack of any surface boundary or approaching short wave impulse out of MX…thus surface heating will be the main driver of storms. Meso scale models are not really showing much today, but would not be surprised if scattered thunderstorms developed once the temperatures rise into the lower 80’s. Storm motions do look to be on the slower side again and with PWS still 1.7 inches or greater…heavy rainfall is certainly possible. Feel the general disorganization today of activity should preclude much of a flash flood threat.

Friday:
Weak ridging weakens on Friday and an impulse heads toward the region during the afternoon hours. High resolution models are showing scattered thunderstorms Friday afternoon mainly NW of US 59. Moisture levels will remain high and the potential for excessive hourly rainfall rates will be possible, but activity should once again remain scattered and generally disorganized.

Saturday:
Upper level ridging does gain a bit more ground and the global models show lowering rain chances however the TX TECH WRF model shows a large thunderstorm complex moving out of WC TX toward SE TX so this potential will have to be watched for raising of rain chances on Saturday.

Sunday-Early Next Week:
Rain chances will increase yet again as this wet pattern continues. A weak frontal boundary will move into the area from the NNE and help to focus and add organization to thunderstorms. Pattern will support a heavy/excessive rainfall threat again with high moisture levels, slow storm motions, and a surface boundary.

Hopefully rainfall over the next few days will remain scattered enough to allow grounds to dry and area watersheds to recede some prior to the onset of potential more significant rainfall next week.

Hydro:
West Fork of the San Jacinto River:
I-45:
The river has crested and is falling this morning. Flow remains very high along the river, but will be receding today.

[Andrew]

nice improvement for north TX: http://droughtmonitor.unl.edu/

http://droughtmonitor.unl.edu/MapsAndDa ... eMaps.aspx

http://droughtmonitor.unl.edu/data/pngs ... h_date.png
http://droughtmonitor.unl.edu/data/pngs ... h_date.png

Also impressive, it doesn't include Wednesday's rain totals so expect further improvement next week. Especially with any additional rain developing.

[Electric Lizard]

nice improvement for north TX: http://droughtmonitor.unl.edu/

http://droughtmonitor.unl.edu/MapsAndDa ... eMaps.aspx

http://droughtmonitor.unl.edu/data/pngs ... h_date.png
http://droughtmonitor.unl.edu/data/pngs ... h_date.png

Also impressive, it doesn't include Wednesday's rain totals so expect further improvement next week. Especially with any additional rain developing.

When was the last time that Texas, Oklahoma, Louisiana and Arkansas were all free of D4 drought?

[djjordan]

Short Lived but plenty for today..... We just got dumped on here in Sugar Land!!! About .50" in a 20 minute period. Wouldn't be anything to us if the ground could take it, but my backyard was still flooded from previous events.
I see all of this is aiming right towards Montgomery County which is not good news at all.