July 2018: Heat Advisories Possible/Rain Returns Next Week

General Weather Discussions and Analysis

Re: July 2018: Unsettled Weather Pattern Continues

Postby srainhoutx » Sat Jul 07, 2018 1:45 pm

07072018 mcd0416.gif


MESOSCALE PRECIPITATION DISCUSSION 0416
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
231 PM EDT SAT JUL 07 2018

AREAS AFFECTED...SERN TX...SRN LA...SRN MS...FAR SW AL

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

VALID 071830Z - 080030Z

SUMMARY...NUMEROUS THUNDERSTORMS WILL DEVELOP THIS AFTERNOON ALONG
THE WEST-CENTRAL GULF COAST AND MOVE SLOWLY ACROSS THE REGION.
RAIN RATES OF UP TO 2-3 IN/HR WILL BE POSSIBLE WHICH COULD LEAD TO
FLASH FLOODING.

DISCUSSION...GOES-16 DAY CONVECTION RGB IS SHOWING A BLOSSOMING OF
INCREASINGLY VIGOROUS CONVECTION IN THE VICINITY OF A DISSIPATING
STALLED FRONT ALONG THE GULF COAST. ADDITIONAL CONVECTION WAS
DEVELOPING ALONG SOME SEA BREEZE BOUNDARIES THAT WERE SLOWLY
ADVANCING INLAND. GOES-16 IR SATELLITE CHANNELS ALSO SHOW A
GENERAL COOLING OF THE CLOUD TOPS...AND REGIONAL RADARS HAVE SHOWN
A SIGNIFICANT EXPANSION IN THE COVERAGE OF CONVECTION OVER THE
PAST COUPLE HOURS (16-18Z). THIS TREND IS EXPECTED TO CONTINUE FOR
THE NEXT HOUR OR TWO WITH AN INCREASING TREND FOR CONSOLIDATION OF
CONVECTION INTO LARGER CLUSTERS...PARTICULARLY NEAR COLLISIONS IN
OUTFLOW BOUNDARIES...SEA BREEZES...AND THE STALLED FRONT. THIS
SHOULD LEAD TO A RELATIVELY HIGH COVERAGE OF RAIN IN THE NEXT SIX
HOURS...WITH POCKETS OF HEAVY RAINFALL IN EXCESS OF 2-3 INCHES.

THE ENVIRONMENT IN THE OUTLINED AREA IS VERY MOIST...WITH NUMEROUS
GPS-PW OBSERVATIONS IN THE 1.9 TO 2.1 INCH RANGE SUPPORTIVE OF
HEAVY RAIN RATES AND EFFICIENT RAINFALL PRODUCTION. THE DEEP LAYER
(0-6KM) MEAN WINDS WERE ONLY AROUND 5-10 KNOTS...INDICATING THE
POTENTIAL FOR VERY SLOW STORM MOTIONS. COLLIDING BOUNDARIES MAY
FURTHER INCREASE RESIDENCE TIME OF HEAVY RAIN IN CERTAIN
LOCATIONS. THESE TWO FACTORS SHOULD BE AMONG THE MOST FAVORABLE
FOR FLASH FLOOD POTENTIAL THIS AFTERNOON AND EARLY THIS EVENING
ACROSS THE REGION.

FLASH FLOOD GUIDANCE IS NOT ESPECIALLY LOW IN THE REGION...WITH
3-HR FFG AROUND 3-4 INCHES. RAINFALL APPROXIMATELY THAT HIGH IS
POSSIBLE GIVEN THE ENVIRONMENT AND STORM MOTIONS...BUT GIVEN THE
LACK OF STRONG LOW-LEVEL FOCUSING MECHANISMS...THE COVERAGE OF
SUCH RAINFALL MAY BE LIMITED IN AREAL EXTENT. THEREFORE...WHILE
FLASH FLOODING IS POSSIBLE IT SHOULD BE LOCALIZED. THE 12Z HREF
SHOWS THE HIGHEST MEAN QPF AND GREATEST PROBABILITIES OF FFG
EXCEEDANCE IN SOUTHWEST AND SOUTH-CENTRAL LOUISIANA. A DECREASING
TREND IN CONVECTIVE COVERAGE AND THE FLASH FLOOD THREAT IS
EXPECTED AROUND SUNSET.

LAMERS

ATTN...WFO...EWX...FWD...HGX...JAN...LCH...LIX...MOB...SHV...
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

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Re: July 2018: Unsettled Weather Pattern Continues

Postby srainhoutx » Sat Jul 07, 2018 2:59 pm

Looks like training along and just S of the frontal boundary across our Northern CWA is producing some 2 to 3 inch rainfall amounts. HGX is monitoring in case Flood Advisories become necessary.

Image
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

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Re: July 2018: Unsettled Weather Pattern Continues

Postby jasons » Sat Jul 07, 2018 4:32 pm

Storms all day missed me to the north and spit out an outflow. Now all the new storms are forming along the outflow / sea breeze collision to my south. I’m stuck in the middle, not a drop.
Last Measurable Rainfall: July 9th
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Re: July 2018: Unsettled Weather Pattern Continues

Postby srainhoutx » Sat Jul 07, 2018 5:08 pm

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
507 PM CDT SAT JUL 7 2018

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
WESTERN HARRIS COUNTY IN SOUTHEASTERN TEXAS...

* UNTIL 600 PM CDT.

* AT 505 PM CDT, DOPPLER RADAR AND AUTOMATED RAIN GAUGES INDICATED
THUNDERSTORMS PRODUCING HEAVY RAIN ACROSS THE WARNED AREA. COUNTY
GAUGES HAVE REPORTED TWO TO THREE INCHES OF RAIN HAVE FALLEN IN
THE PAST HOUR. FLASH FLOODING IS EXPECTED TO BEGIN SHORTLY.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
JERSEY VILLAGE AND NORTHERN ADDICKS PARK TEN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TURN AROUND, DON'T DROWN WHEN ENCOUNTERING FLOODED ROADS. MOST FLOOD
DEATHS OCCUR IN VEHICLES.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS, URBAN AREAS, HIGHWAYS, STREETS AND UNDERPASSES AS
WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

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Re: July 2018: Unsettled Weather Pattern Continues

Postby Texaspirate11 » Sat Jul 07, 2018 5:15 pm

SOME waterspouts reported today off the bay

Threatening clouds and some rumble, but no rain though in my area
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Re: July 2018: Unsettled Weather Pattern Continues

Postby DoctorMu » Sat Jul 07, 2018 5:18 pm

jasons wrote:Storms all day missed me to the north and spit out an outflow. Now all the new storms are forming along the outflow / sea breeze collision to my south. I’m stuck in the middle, not a drop.



There's a fairly large cell on its way toward you from the ENE. Maybe 20-25 min out.
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Re: July 2018: Unsettled Weather Pattern Continues

Postby jasons » Sat Jul 07, 2018 5:44 pm

DoctorMu wrote:
jasons wrote:Storms all day missed me to the north and spit out an outflow. Now all the new storms are forming along the outflow / sea breeze collision to my south. I’m stuck in the middle, not a drop.

here's a fairly large cell on its way toward you from the ENE. Maybe 20-25 min out.


Well, that one is quickly falling apart, but I am watching what is going on Liberty County with interest though. But it's 5:45 already - I might be grasping at straws.
Last Measurable Rainfall: July 9th
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Re: July 2018: Unsettled Weather Pattern Continues

Postby srainhoutx » Sun Jul 08, 2018 8:27 am

Looks like we will see a bit more areal coverage earlier in the day. Reports recently of tropical funnels and a water spout or two near East Beach/Galveston Bay.

07082018 mcd0419.gif


MESOSCALE PRECIPITATION DISCUSSION 0419
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
716 AM EDT SUN JUL 08 2018

AREAS AFFECTED...UPPER TX AND LA COASTAL PLAIN

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

VALID 081116Z - 081616Z

SUMMARY...SHOWERS AND THUNDERSTORMS ARE SLOWLY INCREASING IN
COVERAGE. HOURLY RAIN TOTALS TO 2.5" WITH LOCAL AMOUNTS TO 4" ARE
POSSIBLE WITHIN THE PULSE CONVECTION.

DISCUSSION...AN UPPER LOW WITH A TRAILING UPPER TROUGH/SHORTWAVE
EXTEND FROM EASTERN AR SOUTHWEST THROUGH NORTHERN LA INTO EASTERN
TX PER GOES-16 WATER VAPOR IMAGERY. SINCE 08Z, ML CAPE IN THE
REGION HAS BEEN COMING UP UNDER ITS BASE NEAR AND SOUTH OF I-10
PER SPC MESOANALYSES NEAR AND SOUTH OF A SURFACE
TROUGH/CONVERGENCE ZONE, WITH AN UPTICK IN EFFECTIVE BULK SHEAR
OFFSHORE. PRECIPITABLE WATER VALUES OF 2.1-2.3" EXIST HERE PER
GPS DATA. INFLOW IS WEAK BUT CONVERGENT OUT OF THE SOUTHWEST AT
5-10 KTS PER VAD WIND PROFILES.

WHILE CONVECTION IN SOUTHEAST LA SHOULD PEAK WITHIN THE NEXT
COUPLE HOURS, BOTH THE 06Z GFS-BASED GALVEZ-DAVISON INDEX AND 06Z
HREF PROBABILITIES OF 1"+ IN AN HOUR IMPLY/ADVERTISE A FURTHER
INCREASE IN CELL COVERAGE THROUGH ROUGHLY 16Z FOR SOUTHWEST LA AND
SOUTHEAST TX. AFTER THAT TIME, SEA BREEZE CIRCULATIONS ARE
EXPECTED TO TAKE OVER WHICH WOULD SPREAD THE THUNDERSTORM ACTIVITY
MORE INLAND. BELIEVE THE 06Z CANADIAN REGIONAL MODEL, 00Z NMMB,
00Z NSSL WRF, AND 06Z NAM CONEST HAVE A BETTER GRASP OF WHAT IS
EXPECTED OVER THE NEXT SEVERAL HOURS. TWO WEEK PRECIPITATION
ANOMALIES ARE POSITIVE IN PATCHES NEAR THE LA COAST, WITH AREAS OF
SOUTHEAST TX 200-400% OF NORMAL. WITHIN THIS ENVIRONMENT, MOSTLY
PULSE CONVECTION SHOULD LEAD TO HOURLY PRECIPITATION TOTALS TO
2.5" WITH LOCAL AMOUNTS TO 4". THIS RAINFALL WOULD BE MOST
PROBLEMATIC IN URBAN AREAS.

ROTH

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

Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

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Re: July 2018: Unsettled Weather Pattern Continues

Postby srainhoutx » Sun Jul 08, 2018 11:08 am

07082018 mcd0420.gif


MESOSCALE PRECIPITATION DISCUSSION 0420
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1203 PM EDT SUN JUL 08 2018

AREAS AFFECTED...SC AND SE TEXAS...SW LOUISIANA

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

VALID 081602Z - 082200Z

SUMMARY...VERY SLOW-MOVING STORMS ARE EXPECTED TODAY. THEY WILL
BECOME MORE NUMEROUS AROUND MIDDAY AND MEANDER AROUND THE REGION
THROUGH THE AFTERNOON. RAIN RATES MAY REACH 2-3 IN/HR WHICH COULD
PRODUCE LOCALIZED FLASH FLOODING... ESPECIALLY IN URBANIZED AREAS.

DISCUSSION...CIRA BLENDED TOTAL PW PRODUCT SHOWS PW VALUES AROUND
1.9 TO 2.3 INCHES OVER MOST OF THE OUTLINED REGION FROM
SOUTH-CENTRAL TEXAS INTO SOUTHWEST LOUISIANA. THIS CLOSELY MATCHES
BOTH 12Z SOUNDINGS FROM THE AREA...AND NUMEROUS GPS-PW
OBSERVATIONS WITH THE HIGHEST OBSERVATIONS FROM HOUSTON METRO TO
NEAR LAKE CHARLES LOUISIANA (AROUND 2.2 INCHES). DESPITE THE
TYPICAL HUMID CLIMATE ALONG THE GULF COAST IN THE SUMMER
MONTHS...2.2 INCH PW VALUES WOULD BE AROUND OR JUST ABOVE THE 90TH
PERCENTILE FOR MID JULY ON THE LAKE CHARLES SOUNDING CLIMATOLOGY.
THUS ANOMALOUSLY HIGH LEVELS OF ATMOSPHERIC MOISTURE ARE IN
PLACE...AND SHOULD PROMOTE EFFICIENT RAINFALL PRODUCTION IN
STORMS.

FURTHER EXACERBATING THE THREAT OF LOCALLY HEAVY RAINFALL ARE THE
VERY WEAK WINDS THROUGH MUCH OF THE DEPTH OF THE TROPOSPHERE. A
LOW-LEVEL TROUGH (SFC-850MB) STRETCHED IN A BROAD ARC FROM NEAR
LAREDO TO NEAR BATON ROUGE...AND THIS WAS COINCIDENT WITH A
WEAKNESS IN THE MID-UPPER LEVEL FLOW. FORECAST MEAN WIND
(850-200MB) ACROSS THE REGION WAS GENERALLY AROUND OR LESS THAN 5
KNOTS. FLOW THIS WEAK SHOULD ALLOW STORMS TO BE NEARLY STATIONARY
UPON INITIAL DEVELOPMENT...WITH PERHAPS SOME SLOW PROPAGATION AS
CELL MERGERS FORCE DEVELOPMENT OF SMALL CLUSTERS AND LOCALIZED
COLD POOLS. THERE IS NOT A STRONG LOW-LEVEL BOUNDARY FOR
CONVECTION TO FOCUS ON...SO THE CONVECTION MAY NOT PERSIST IN THE
SAME AREA FOR MANY HOURS. HOWEVER...THE SLOW DRIFT AND POTENTIAL
FOR CELL MERGERS AND INTERACTIONS SUGGESTS THAT HEAVY RAIN CAN
PROBABLY BE SUSTAINED AT SOME LOCATIONS FOR A COUPLE HOURS...WHICH
MAY LEAD TO A FLASH FLOOD THREAT. RAIN RATES OF 2-3 IN/HR SEEM
ACHIEVABLE GIVEN THE DEEP SATURATED PROFILES...MODERATE TO STRONG
INSTABILITY...AND VERY SLOW STORM MOTIONS.

ONE MESOSCALE FEATURE OF INTEREST IS A NNE PROPAGATING OUTFLOW
BOUNDARY...EVIDENT ON GOES-16 VISIBLE SATELLITE LOOPS AND KHGX
RADAR. AT 16Z IT STRETCHED FROM ABOUT 40W OF VCT TO NEAR BYY TO
NEAR 25ESE OF SGNT2. EXTRAPOLATING CURRENT TRENDS WOULD PUSH THE
OUTFLOW BOUNDARY INTO THE VICINITY OF HARRIS COUNTY AND HOUSTON
METRO BETWEEN 19Z AND 21Z. THIS MAY PROVIDE ADDITIONAL FOCUS FOR
CONVECTIVE ORGANIZATION AND DEVELOPMENT JUST DOWNSTREAM FOR AN
HOUR OR TWO...AND THUS BRIEFLY ENHANCE RAIN RATES. SOME SCATTERED
CONVECTION WAS ALREADY DEVELOPING ACROSS HOUSTON METRO...BUT THIS
MAY ENHANCE RAIN RATES ALONG THE I-10 CORRIDOR EARLY THIS
AFTERNOON.

LAMERS

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

Image
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

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Re: July 2018: Unsettled Weather Pattern Continues

Postby srainhoutx » Sun Jul 08, 2018 11:13 am

FLOOD ADVISORY
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1107 AM CDT SUN JUL 8 2018

CHAMBERS TX-HARRIS TX-
1107 AM CDT SUN JUL 8 2018

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

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

* UNTIL 100 PM CDT.

* AT 1107 AM 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 IN THE PAST 30
MINUTES OVER BAYTOWN.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
EASTERN PASADENA, BAYTOWN, LA PORTE, DEER PARK, SEABROOK, BEACH
CITY, CLOVERLEAF, HIGHLANDS, CLEAR LAKE, CHANNELVIEW, BARRETT,
EASTERN SOUTH BELT / ELLINGTON, SOUTHWESTERN MONT BELVIEU, TAYLOR
LAKE VILLAGE, EL LAGO, SHOREACRES, COVE, MORGAN'S POINT, ELLINGTON
FIELD AND EASTERN HOUSTON SHIP CHANNEL.
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

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