Enjoy the lull in the rainfall today. More is on the way tomorrow and into the weekend as storms rotate around the backside of the weakening upper level low. Flash Flood Watches may be re-issued tomorrow.
THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF GULF OF MEXICO
AND SOUTHEAST TEXAS.
.DAY ONE...TODAY AND TONIGHT
THE HAZARDOUS WEATHER THREAT WILL BE MINIMAL THROUGH TONIGHT.
THERE IS A CHANCE FOR REDEVELOPING RAIN AND SCATTERED THUNDERSTORM
CLUSTERS. RECENTLY HIGH RAINFALL ACCUMULATIONS HAVE SATURATED
GROUNDS...THUS HOURLY RAINFALL RATES EXCEEDING 2 INCHES COULD
INDUCE FLOODING ISSUES. THE SECONDARY THREATS WILL BE FREQUENT
CLOUD TO GROUND LIGHTNING STRIKES AND DAMAGING THUNDERSTORM
DOWNBURST WINDS.
.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY
RETURNING MODERATE TO HEAVY RAINFALL EPISODES...WITHIN MORE ORGANIZED
THUNDERSTORM CLUSTERS...WILL HAVE THE POTENTIAL TO PRODUCE MORE AREAWIDE
FLOODING THROUGH SUNDAY.
.SPOTTER INFORMATION STATEMENT...
TRAINED SPOTTERS NEED TO BE AWARE OF RAPIDLY CHANGING WEATHER CONDITIONS
THROUGH THE WEEKEND. SPOTTERS NEED BE PREPARED TO REPORT ANY SIGNIFICANT
WEATHER SITUATION...OR DAMAGE PRODUCED BY SUCH...TO LAW ENFORCEMENT
OR THEIR LOCAL WEATHER SERVICE OFFICE.
May: IAH Does Not Reach 90 During May. 1970 Mark Achieved
Thursday morning email from Jeff Lindner:
First morning in 48 hours that has not exhibited heavy rainfall across the region…but break appears short lived.
Well defined upper level low over northern Louisiana with a trough axis extending SSW into the Gulf of Mexico has helped to focus the heavy and excessive rainfall east of the area in the last 12-18 hours. This upper level system has nearly stalled and is forecast to begin to move WSW over the next 24 hours toward eastern TX which allows the trough axis offshore to move northwest toward the coast. A current drier air mass in place will be replaced by a surge of moisture off the Gulf of Mexico and as increasing lift approaches from the NE expect additional showers and thunderstorms to develop.
Today looks the driest with the main dynamics to our east and moisture profiles down from the previous days. SE TX will lie in the SW flank of the upper level system with the focal point for storm development over E and NE TX with storm motions to the SSW…expect any activity this afternoon to remain isolated to scattered.
As the core of the system moves closer on Friday the air mass will heat in the morning becoming unstable. Models are not in great agreement on when and where any southwestward moving vort lobe will initiate another thunderstorm complex, but best guess at the moment is somewhere over NE/E TX and then track slowly toward the SSW or SW in the afternoon and evening hours. Looks like storm motions will be slowing also and favorable upstream moisture inflow from the SSW/SW of an untapped humid air mass looks to drive potential cell training into the evening hours over portions of the area.
Area falls into even more favorable position of the low by early Saturday with the core located either near or NW of SE TX suggesting favorable low level moisture convergence on the SE flank of the system near the coast or just inland. Could see some “core” rainfall near the center of the feature early Saturday morning but not confident in the placement of that this far out. Depending on how much development there is Friday afternoon, Saturday morning could end up being the greatest potential for additional excessive rainfall mainly across the east and southeast parts of the region.
Upper system begins to break down and shear apart leaving a height weakness between a building mid level ridge out of MX and sub-tropical ridging building from the east allowing for a final day of scattered thunderstorms on Sunday before ridging takes hold ending rain chances.
Additional rainfall amounts Friday-Sunday could average 1-2 inches with isolated amounts upwards of 4-6 inches possible.
Hydro:
San Bernard River: minor to moderate flooding is in progress along the entire river from southern Austin County to the Gulf of Mexico. River should crest and begin to fall over the next 24 hour.
West Fork San Jacinto River: River has crested overnight and falling within banks currently
Cypress Creek: creek has crested and is falling on the middle and lower portion of the channel, but upper portion of the channel is still rising due to run-off from Waller County.
Additional rainfall over the next 48 hours could alter recessions and result in additional rises.
First morning in 48 hours that has not exhibited heavy rainfall across the region…but break appears short lived.
Well defined upper level low over northern Louisiana with a trough axis extending SSW into the Gulf of Mexico has helped to focus the heavy and excessive rainfall east of the area in the last 12-18 hours. This upper level system has nearly stalled and is forecast to begin to move WSW over the next 24 hours toward eastern TX which allows the trough axis offshore to move northwest toward the coast. A current drier air mass in place will be replaced by a surge of moisture off the Gulf of Mexico and as increasing lift approaches from the NE expect additional showers and thunderstorms to develop.
Today looks the driest with the main dynamics to our east and moisture profiles down from the previous days. SE TX will lie in the SW flank of the upper level system with the focal point for storm development over E and NE TX with storm motions to the SSW…expect any activity this afternoon to remain isolated to scattered.
As the core of the system moves closer on Friday the air mass will heat in the morning becoming unstable. Models are not in great agreement on when and where any southwestward moving vort lobe will initiate another thunderstorm complex, but best guess at the moment is somewhere over NE/E TX and then track slowly toward the SSW or SW in the afternoon and evening hours. Looks like storm motions will be slowing also and favorable upstream moisture inflow from the SSW/SW of an untapped humid air mass looks to drive potential cell training into the evening hours over portions of the area.
Area falls into even more favorable position of the low by early Saturday with the core located either near or NW of SE TX suggesting favorable low level moisture convergence on the SE flank of the system near the coast or just inland. Could see some “core” rainfall near the center of the feature early Saturday morning but not confident in the placement of that this far out. Depending on how much development there is Friday afternoon, Saturday morning could end up being the greatest potential for additional excessive rainfall mainly across the east and southeast parts of the region.
Upper system begins to break down and shear apart leaving a height weakness between a building mid level ridge out of MX and sub-tropical ridging building from the east allowing for a final day of scattered thunderstorms on Sunday before ridging takes hold ending rain chances.
Additional rainfall amounts Friday-Sunday could average 1-2 inches with isolated amounts upwards of 4-6 inches possible.
Hydro:
San Bernard River: minor to moderate flooding is in progress along the entire river from southern Austin County to the Gulf of Mexico. River should crest and begin to fall over the next 24 hour.
West Fork San Jacinto River: River has crested overnight and falling within banks currently
Cypress Creek: creek has crested and is falling on the middle and lower portion of the channel, but upper portion of the channel is still rising due to run-off from Waller County.
Additional rainfall over the next 48 hours could alter recessions and result in additional rises.
-
srainhoutx
- Site Admin
- Posts: 19622
- Joined: Tue Feb 02, 2010 2:32 pm
- Location: Maggie Valley, NC
- Contact:
Morning Update from Jeff:
First morning in 48 hours that has not exhibited heavy rainfall across the region…but break appears short lived.
Well defined upper level low over northern Louisiana with a trough axis extending SSW into the Gulf of Mexico has helped to focus the heavy and excessive rainfall east of the area in the last 12-18 hours. This upper level system has nearly stalled and is forecast to begin to move WSW over the next 24 hours toward eastern TX which allows the trough axis offshore to move northwest toward the coast. A current drier air mass in place will be replaced by a surge of moisture off the Gulf of Mexico and as increasing lift approaches from the NE expect additional showers and thunderstorms to develop.
Today looks the driest with the main dynamics to our east and moisture profiles down from the previous days. SE TX will lie in the SW flank of the upper level system with the focal point for storm development over E and NE TX with storm motions to the SSW…expect any activity this afternoon to remain isolated to scattered.
As the core of the system moves closer on Friday the air mass will heat in the morning becoming unstable. Models are not in great agreement on when and where any southwestward moving vort lobe will initiate another thunderstorm complex, but best guess at the moment is somewhere over NE/E TX and then track slowly toward the SSW or SW in the afternoon and evening hours. Looks like storm motions will be slowing also and favorable upstream moisture inflow from the SSW/SW of an untapped humid air mass looks to drive potential cell training into the evening hours over portions of the area.
Area falls into even more favorable position of the low by early Saturday with the core located either near or NW of SE TX suggesting favorable low level moisture convergence on the SE flank of the system near the coast or just inland. Could see some “core” rainfall near the center of the feature early Saturday morning but not confident in the placement of that this far out. Depending on how much development there is Friday afternoon, Saturday morning could end up being the greatest potential for additional excessive rainfall mainly across the east and southeast parts of the region.
Upper system begins to break down and shear apart leaving a height weakness between a building mid level ridge out of MX and sub-tropical ridging building from the east allowing for a final day of scattered thunderstorms on Sunday before ridging takes hold ending rain chances.
Additional rainfall amounts Friday-Sunday could average 1-2 inches with isolated amounts upwards of 4-6 inches possible.
Hydro:
San Bernard River: minor to moderate flooding is in progress along the entire river from southern Austin County to the Gulf of Mexico. River should crest and begin to fall over the next 24 hour.
West Fork San Jacinto River: River has crested overnight and falling within banks currently
Cypress Creek: creek has crested and is falling on the middle and lower portion of the channel, but upper portion of the channel is still rising due to run-off from Waller County.
Additional rainfall over the next 48 hours could alter recessions and result in additional rises.
First morning in 48 hours that has not exhibited heavy rainfall across the region…but break appears short lived.
Well defined upper level low over northern Louisiana with a trough axis extending SSW into the Gulf of Mexico has helped to focus the heavy and excessive rainfall east of the area in the last 12-18 hours. This upper level system has nearly stalled and is forecast to begin to move WSW over the next 24 hours toward eastern TX which allows the trough axis offshore to move northwest toward the coast. A current drier air mass in place will be replaced by a surge of moisture off the Gulf of Mexico and as increasing lift approaches from the NE expect additional showers and thunderstorms to develop.
Today looks the driest with the main dynamics to our east and moisture profiles down from the previous days. SE TX will lie in the SW flank of the upper level system with the focal point for storm development over E and NE TX with storm motions to the SSW…expect any activity this afternoon to remain isolated to scattered.
As the core of the system moves closer on Friday the air mass will heat in the morning becoming unstable. Models are not in great agreement on when and where any southwestward moving vort lobe will initiate another thunderstorm complex, but best guess at the moment is somewhere over NE/E TX and then track slowly toward the SSW or SW in the afternoon and evening hours. Looks like storm motions will be slowing also and favorable upstream moisture inflow from the SSW/SW of an untapped humid air mass looks to drive potential cell training into the evening hours over portions of the area.
Area falls into even more favorable position of the low by early Saturday with the core located either near or NW of SE TX suggesting favorable low level moisture convergence on the SE flank of the system near the coast or just inland. Could see some “core” rainfall near the center of the feature early Saturday morning but not confident in the placement of that this far out. Depending on how much development there is Friday afternoon, Saturday morning could end up being the greatest potential for additional excessive rainfall mainly across the east and southeast parts of the region.
Upper system begins to break down and shear apart leaving a height weakness between a building mid level ridge out of MX and sub-tropical ridging building from the east allowing for a final day of scattered thunderstorms on Sunday before ridging takes hold ending rain chances.
Additional rainfall amounts Friday-Sunday could average 1-2 inches with isolated amounts upwards of 4-6 inches possible.
Hydro:
San Bernard River: minor to moderate flooding is in progress along the entire river from southern Austin County to the Gulf of Mexico. River should crest and begin to fall over the next 24 hour.
West Fork San Jacinto River: River has crested overnight and falling within banks currently
Cypress Creek: creek has crested and is falling on the middle and lower portion of the channel, but upper portion of the channel is still rising due to run-off from Waller County.
Additional rainfall over the next 48 hours could alter recessions and result in additional rises.
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey
Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
loops on a grander scale, from: http://www.atmos.washington.edu/~ovens/loops/
http://www.atmos.washington.edu/~ovens/ ... nced+/48h/
http://www.atmos.washington.edu/~ovens/ ... anced+/8d/
speed it up, slow it down, increase or decrease # of days in loop, makes it easier to see patterns affecting this low
WPC's 7-day QPF loop: http://www.wpc.ncep.noaa.gov/qpf/qpfloop_6hr_d17.html
from WPC's QPF Discussion: http://www.wpc.ncep.noaa.gov/discussion ... isc=qpfpfd
DAY 1
CENTRAL GULF COAST
THE HEAVY TO EXCESSIVE RAINFALL THREAT WILL CONTINUE DAY 1 TO THE
EAST AND SOUTHEAST OF THE LOWER MS VALLEY CLOSED LOW. LITTLE
MOVEMENT EXPECTED THIS PERIOD TO THIS CLOSED LOW WITH PERSISTENT
MOIST SOUTHERLY LOW LEVEL FLOW CONTINUING OFF THE GULF OF MEXICO.
PW VALUES IN THIS INFLOW REGION TO THE SOUTHEAST OF THE STATIONARY
MID TO UPPER LEVEL LOW WILL REMAIN 1.5-2+ STANDARD DEVIATIONS
ABOVE THE MEAN---SUPPORTING THE HEAVY TO EXCESSIVE THREAT.
CURRENT RADAR TRENDS ARE SHOWING CONVECTION CONCENTRATING ON THE
EASTERN SIDE OF THIS CLOSED LOW--WITH THE 1200 UTC MAY 28 VERSIONS
OF THE HI RES ARW AND NMM SEEMING TO HAVE THE BEST HANDLE ON THE
CURRENT SITUATION. THESE MODELS MAINTAIN THE MAX PRECIPITATION IN
THE VICINITY OF FAR EASTERN LA---FAR SOUTHERN MS---FAR SOUTHERN AL
INTO THE WESTERN FL PANHANDLE--WHILE THE NEW HI RES MODELS REFORM
MAX PRECIP FARTHER TO THE WEST CLOSER TO THE LONGITUDE OF THE
CLOSED LOW---ALBEIT STILL TO ITS SOUTHEAST. THE 0000 UTC HI RES
GUIDANCE DOES NOT HAVE A HANDLE ON THE ONGOING CONVECTION---A
COMMON BIAS OF THE HI RES RUNS---BUT INSTEAD CONCENTRATES HEAVY
PRECIP POTENTIAL ON ADDITIONAL CONVECTION DEVELOPING AHEAD OF THE
STATIONARY CLOSED LOW. VERY HEAVY RAINFALL AMOUNTS LIKELY ALONG
THE CENTRAL GULF COAST WHERE INFLOW INTO THE ESTABLISHED OUTFLOW
BOUNDARY WILL SUPPORT REGENERATION OF CELLS AND VERY SLOW
MOVEMENT/TRAINING OF CONVECTION AS PER THE 1200 UTC MAY 28 HI RES
ARW/NMM SOLUTIONS. IN AREAS OF TRAINING 1-2"+ RAINFALL AMOUNTS IN
AN HOUR AND TOTALS OF 5"+ POSSIBLE.
DAY 2/3
...LOWER AND MID MS VALLEY/CENTRAL GULF COAST...
THE UPPER-LEVEL LOW OVER THE LOWER MISSISSIPPI VALLEY WILL NOT
MOVE APPRECIABLY FOR THE REST OF THE WEEK AS IT CONTINUES TO
WEAKEN. BY SATURDAY AFTERNOON THE LOW MAY SLOWLY RETROGRADE AS
UPPER-LEVEL RIDGING EXPANDS ACROSS THE SOUTHEASTERN STATES. THE
INCREASING HEIGHTS ACROSS THE SOUTHEAST/GULF COAST BY THIS TIME
WILL SERVE TO REDUCE THE COVERAGE OF PRECIPITATION SOMEWHAT. FOR
DAY 2...THE PLUME OF MOISTURE FROM THE GULF OF MEXICO WILL
CONTINUE ACROSS THE CENTRAL GULF COAST STATES....WITH AREAL
AVERAGED 1-2" OF RAIN FORECAST...AND LOCALLY HIGHER AMOUNTS. ON
DAY 3 THE AXIS OF BEST MOISTURE SHIFTS SLIGHTLY WESTWARD AS THE
UPPER-LEVEL LOW RETROGRADES...WITH SOMEWHAT LIGHTER QPF AMOUNTS
ALSO EXPECTED. GIVEN THE ALREADY LOWERED FLASH FLOOD GUIDANCE OVER
PORTIONS OF THE CENTRAL GULF COAST...AND RAINFALL EXPECTED DURING
THE DAY 1 PERIOD...HAVE OUTLINED THE CENTRAL GULF COAST FOR SLIGHT
RISK OF EXCESSIVE RAINFALL ON DAY 2. GENERALLY FOLLOWED A BLEND OF
THE ECMWF...GFS AND SREF FOR THIS AREA.
to clarify the geographic region language:
http://www.wpc.ncep.noaa.gov/bndrys1.gif
http://www.wpc.ncep.noaa.gov/bndrys2.gif
http://www.atmos.washington.edu/~ovens/ ... nced+/48h/
http://www.atmos.washington.edu/~ovens/ ... anced+/8d/
speed it up, slow it down, increase or decrease # of days in loop, makes it easier to see patterns affecting this low
WPC's 7-day QPF loop: http://www.wpc.ncep.noaa.gov/qpf/qpfloop_6hr_d17.html
from WPC's QPF Discussion: http://www.wpc.ncep.noaa.gov/discussion ... isc=qpfpfd
DAY 1
CENTRAL GULF COAST
THE HEAVY TO EXCESSIVE RAINFALL THREAT WILL CONTINUE DAY 1 TO THE
EAST AND SOUTHEAST OF THE LOWER MS VALLEY CLOSED LOW. LITTLE
MOVEMENT EXPECTED THIS PERIOD TO THIS CLOSED LOW WITH PERSISTENT
MOIST SOUTHERLY LOW LEVEL FLOW CONTINUING OFF THE GULF OF MEXICO.
PW VALUES IN THIS INFLOW REGION TO THE SOUTHEAST OF THE STATIONARY
MID TO UPPER LEVEL LOW WILL REMAIN 1.5-2+ STANDARD DEVIATIONS
ABOVE THE MEAN---SUPPORTING THE HEAVY TO EXCESSIVE THREAT.
CURRENT RADAR TRENDS ARE SHOWING CONVECTION CONCENTRATING ON THE
EASTERN SIDE OF THIS CLOSED LOW--WITH THE 1200 UTC MAY 28 VERSIONS
OF THE HI RES ARW AND NMM SEEMING TO HAVE THE BEST HANDLE ON THE
CURRENT SITUATION. THESE MODELS MAINTAIN THE MAX PRECIPITATION IN
THE VICINITY OF FAR EASTERN LA---FAR SOUTHERN MS---FAR SOUTHERN AL
INTO THE WESTERN FL PANHANDLE--WHILE THE NEW HI RES MODELS REFORM
MAX PRECIP FARTHER TO THE WEST CLOSER TO THE LONGITUDE OF THE
CLOSED LOW---ALBEIT STILL TO ITS SOUTHEAST. THE 0000 UTC HI RES
GUIDANCE DOES NOT HAVE A HANDLE ON THE ONGOING CONVECTION---A
COMMON BIAS OF THE HI RES RUNS---BUT INSTEAD CONCENTRATES HEAVY
PRECIP POTENTIAL ON ADDITIONAL CONVECTION DEVELOPING AHEAD OF THE
STATIONARY CLOSED LOW. VERY HEAVY RAINFALL AMOUNTS LIKELY ALONG
THE CENTRAL GULF COAST WHERE INFLOW INTO THE ESTABLISHED OUTFLOW
BOUNDARY WILL SUPPORT REGENERATION OF CELLS AND VERY SLOW
MOVEMENT/TRAINING OF CONVECTION AS PER THE 1200 UTC MAY 28 HI RES
ARW/NMM SOLUTIONS. IN AREAS OF TRAINING 1-2"+ RAINFALL AMOUNTS IN
AN HOUR AND TOTALS OF 5"+ POSSIBLE.
DAY 2/3
...LOWER AND MID MS VALLEY/CENTRAL GULF COAST...
THE UPPER-LEVEL LOW OVER THE LOWER MISSISSIPPI VALLEY WILL NOT
MOVE APPRECIABLY FOR THE REST OF THE WEEK AS IT CONTINUES TO
WEAKEN. BY SATURDAY AFTERNOON THE LOW MAY SLOWLY RETROGRADE AS
UPPER-LEVEL RIDGING EXPANDS ACROSS THE SOUTHEASTERN STATES. THE
INCREASING HEIGHTS ACROSS THE SOUTHEAST/GULF COAST BY THIS TIME
WILL SERVE TO REDUCE THE COVERAGE OF PRECIPITATION SOMEWHAT. FOR
DAY 2...THE PLUME OF MOISTURE FROM THE GULF OF MEXICO WILL
CONTINUE ACROSS THE CENTRAL GULF COAST STATES....WITH AREAL
AVERAGED 1-2" OF RAIN FORECAST...AND LOCALLY HIGHER AMOUNTS. ON
DAY 3 THE AXIS OF BEST MOISTURE SHIFTS SLIGHTLY WESTWARD AS THE
UPPER-LEVEL LOW RETROGRADES...WITH SOMEWHAT LIGHTER QPF AMOUNTS
ALSO EXPECTED. GIVEN THE ALREADY LOWERED FLASH FLOOD GUIDANCE OVER
PORTIONS OF THE CENTRAL GULF COAST...AND RAINFALL EXPECTED DURING
THE DAY 1 PERIOD...HAVE OUTLINED THE CENTRAL GULF COAST FOR SLIGHT
RISK OF EXCESSIVE RAINFALL ON DAY 2. GENERALLY FOLLOWED A BLEND OF
THE ECMWF...GFS AND SREF FOR THIS AREA.
to clarify the geographic region language:
http://www.wpc.ncep.noaa.gov/bndrys1.gif
http://www.wpc.ncep.noaa.gov/bndrys2.gif
Last edited by unome on Thu May 29, 2014 12:01 pm, edited 1 time in total.
a mesoscale discussion for our neighbors in Louisianna
http://www.wpc.ncep.noaa.gov/metwatch/m ... 81&yr=2014
MESOSCALE PRECIPITATION DISCUSSION 0081...CORRECTION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1109 AM EDT THU MAY 29 2014
CORRECTED FOR TYPOS IN BOTH PARAGRAPHS
AREAS AFFECTED...SOUTH-CENTRAL LA AND SOUTHWEST MS
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 291433Z - 291733Z
SUMMARY...A NARROW BAND OF THUNDERSTORMS IS DEVELOPING ACROSS
SOUTH-CENTRAL LA AND SHOWING NO MOVEMENT. REGIONAL FLASH FLOODING
IS POSSIBLE OVER THE NEXT FEW HOURS.
DISCUSSION...THE INTERSECTION OF A SURFACE TROUGH/BAROCLINIC
TROUGH AND AN OUTFLOW BOUNDARY IS HELPING TO FOCUS A NEW LINE OF
THUNDERSTORMS NEAR THE ATCHAFALAYA RIVER BASIN. THE THUNDERSTORMS
HAVE SHOWN LITTLE SIGN OF MOVEMENT AS THEY TRAIN ALONG A NARROW
BAND. THE MOST RECENT MESOSCALE GUIDANCE SHOWS A MODERATE SIGNAL
FOR HEAVY RAINFALL IN THIS AREA. THE 0-3 KM WIND SHEAR IS NEAR 25
KTS AND CAPE VALUES ARE CLOSE TO 1000 J/KG, NEAR THE LOWER
THRESHOLD FOR THE WET MULTI-CELL ENVIRONMENT. PRECIPITABLE WATER
VALUES ARE SUFFICIENT FOR POTENTIALLY HEAVY RAINFALL, SITTING NEAR
1.75", WHICH IS ABOVE THE 90TH PERCENTILE FOR LATE MAY.
OVER THE NEXT FEW HOURS, A SURFACE COLD POOL IS EXPECTED TO
DEVELOP NEAR THE NARROW BAND WHICH SHOULD MOVE THE THUNDERSTORMS
SLOWLY EAST AND SOUTHEASTWARD PER 06Z GFS CORFIDI VECTORS. THE
00Z ARW FORECASTS THE MAXIMUM CAPE VALUES TO SHIFT NORTHEAST WITH
TIME, WHICH SHOULD ALLOW THE THUNDERSTORM BAND TO EXTEND NORTHEAST
AND WOULD OCCUR AS THE WESTERN PORTION OF AN OUTFLOW BOUNDARY
ACROSS SOUTHERN LA RETURNS NORTHEAST (AS THERE IS NO CONVECTION IN
SOUTHEAST LA TO MAINTAIN THE BOUNDARY'S CURRENT LOCATION).
RAINFALL RATES NEAR 2" AN HOUR IN STRONGER CELLS COULD CAUSE
REGIONAL FLASH FLOODING.
ROTH
ATTN...WFO...JAN...LIX...LCH...
ATTN...RFC...LMRFC...
LAT...LON 29679266 30389241 31619168 31769122 31459113 30839136
29999174 29519218 29519254 29679266
Last Updated: 1109 AM EDT THU MAY 29 2014
http://www.wpc.ncep.noaa.gov/metwatch/m ... 81&yr=2014
MESOSCALE PRECIPITATION DISCUSSION 0081...CORRECTION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1109 AM EDT THU MAY 29 2014
CORRECTED FOR TYPOS IN BOTH PARAGRAPHS
AREAS AFFECTED...SOUTH-CENTRAL LA AND SOUTHWEST MS
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 291433Z - 291733Z
SUMMARY...A NARROW BAND OF THUNDERSTORMS IS DEVELOPING ACROSS
SOUTH-CENTRAL LA AND SHOWING NO MOVEMENT. REGIONAL FLASH FLOODING
IS POSSIBLE OVER THE NEXT FEW HOURS.
DISCUSSION...THE INTERSECTION OF A SURFACE TROUGH/BAROCLINIC
TROUGH AND AN OUTFLOW BOUNDARY IS HELPING TO FOCUS A NEW LINE OF
THUNDERSTORMS NEAR THE ATCHAFALAYA RIVER BASIN. THE THUNDERSTORMS
HAVE SHOWN LITTLE SIGN OF MOVEMENT AS THEY TRAIN ALONG A NARROW
BAND. THE MOST RECENT MESOSCALE GUIDANCE SHOWS A MODERATE SIGNAL
FOR HEAVY RAINFALL IN THIS AREA. THE 0-3 KM WIND SHEAR IS NEAR 25
KTS AND CAPE VALUES ARE CLOSE TO 1000 J/KG, NEAR THE LOWER
THRESHOLD FOR THE WET MULTI-CELL ENVIRONMENT. PRECIPITABLE WATER
VALUES ARE SUFFICIENT FOR POTENTIALLY HEAVY RAINFALL, SITTING NEAR
1.75", WHICH IS ABOVE THE 90TH PERCENTILE FOR LATE MAY.
OVER THE NEXT FEW HOURS, A SURFACE COLD POOL IS EXPECTED TO
DEVELOP NEAR THE NARROW BAND WHICH SHOULD MOVE THE THUNDERSTORMS
SLOWLY EAST AND SOUTHEASTWARD PER 06Z GFS CORFIDI VECTORS. THE
00Z ARW FORECASTS THE MAXIMUM CAPE VALUES TO SHIFT NORTHEAST WITH
TIME, WHICH SHOULD ALLOW THE THUNDERSTORM BAND TO EXTEND NORTHEAST
AND WOULD OCCUR AS THE WESTERN PORTION OF AN OUTFLOW BOUNDARY
ACROSS SOUTHERN LA RETURNS NORTHEAST (AS THERE IS NO CONVECTION IN
SOUTHEAST LA TO MAINTAIN THE BOUNDARY'S CURRENT LOCATION).
RAINFALL RATES NEAR 2" AN HOUR IN STRONGER CELLS COULD CAUSE
REGIONAL FLASH FLOODING.
ROTH
ATTN...WFO...JAN...LIX...LCH...
ATTN...RFC...LMRFC...
LAT...LON 29679266 30389241 31619168 31769122 31459113 30839136
29999174 29519218 29519254 29679266
Last Updated: 1109 AM EDT THU MAY 29 2014
-
srainhoutx
- Site Admin
- Posts: 19622
- Joined: Tue Feb 02, 2010 2:32 pm
- Location: Maggie Valley, NC
- Contact:
The entire 12Z suite of global and shorter term meso guidance is in agreement that the upper low will retrograde to the W into tomorrow and Saturday. While it is still uncertain as to where and who may see the highest rainfall chances, it is clear that a building Ridge across the Eastern US will likely push this feature back closer to our Region and provide a chance of potentially heavy rainfall once again particularly across the Eastern half of Texas into Western/Central Louisiana. It is also noteworthy that if we do not reach a high of 90 on Saturday, a very long streak that dates back to May 1970 will be achieved where 90 degrees was not measured in Houston (officially) for the month of May.
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey
Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
Thanks Srain.
That is pretty wild about that going back to '70.
That is pretty wild about that going back to '70.
-
srainhoutx
- Site Admin
- Posts: 19622
- Joined: Tue Feb 02, 2010 2:32 pm
- Location: Maggie Valley, NC
- Contact:
The Day 1 and Day 2 QPF is Updated and does suggest we could see a general 1-2 inches of additional rain with isolated higher amounts possible. As always, we cannot know or accurately forecast any mesoscale features beyond a few hours.
- Attachments
-
-
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey
Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
-
srainhoutx
- Site Admin
- Posts: 19622
- Joined: Tue Feb 02, 2010 2:32 pm
- Location: Maggie Valley, NC
- Contact:
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
420 PM CDT THU MAY 29 2014
TXZ227-237-292145-
BRAZORIA TX-FORT BEND TX-
420 PM CDT THU MAY 29 2014
AT 414 PM CDT...THE BRAZORIA COUNTY SHERIFF AND EMERGENCY MANAGEMENT
OFFICE REPORTED A FUNNEL CLOUD 5 MILES NORTH OF ANGLETON. FUNNEL
CLOUDS OCCASIONALLY EXTEND TO THE GROUND AND CAN BECOME A BRIEF
TORNADO.
SHOWERS WERE BEGINNING TO DEVELOP ALONG THE SEA BREEZE AND COLLIDING
BOUNDARIES COULD PROVIDE ENOUGH IMPETUS TO PRODUCE ADDITIONAL FUNNEL
CLOUDS OR A BRIEF TORNADO...VERY SIMILAR TO YESTERDAY AFTERNOON.
THIS SHOWER MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
420 PM CDT THU MAY 29 2014
TXZ227-237-292145-
BRAZORIA TX-FORT BEND TX-
420 PM CDT THU MAY 29 2014
AT 414 PM CDT...THE BRAZORIA COUNTY SHERIFF AND EMERGENCY MANAGEMENT
OFFICE REPORTED A FUNNEL CLOUD 5 MILES NORTH OF ANGLETON. FUNNEL
CLOUDS OCCASIONALLY EXTEND TO THE GROUND AND CAN BECOME A BRIEF
TORNADO.
SHOWERS WERE BEGINNING TO DEVELOP ALONG THE SEA BREEZE AND COLLIDING
BOUNDARIES COULD PROVIDE ENOUGH IMPETUS TO PRODUCE ADDITIONAL FUNNEL
CLOUDS OR A BRIEF TORNADO...VERY SIMILAR TO YESTERDAY AFTERNOON.
THIS SHOWER MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey
Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
here we go again.....days 1-3 QPF currently shows 1.4 as the max in a small area, of course, it wasn't exactly great at giving us the 8+ inches we got before, so grain of salt there, could be higher or lower in any place
of course, as always... listen to your local weather service and emergency professionals for facts, and that would not be me ;) https://www.facebook.com/photo.php?fbid ... =1&theater
http://www.wpc.ncep.noaa.gov/qpf/d13_fill.gif
of course, as always... listen to your local weather service and emergency professionals for facts, and that would not be me ;) https://www.facebook.com/photo.php?fbid ... =1&theater
http://www.wpc.ncep.noaa.gov/qpf/d13_fill.gif
Looks like the ULL is coming back. (Radar)
Sure looks like it Rip76
-
Paul Robison
What do the prospects look like for strong to damaging thunderstorms friday and saturday? (Remember what happened on Monday when that lady was killed?)
Wut?Paul Robison wrote:What do the prospects look like for strong to damaging thunderstorms friday and saturday? (Remember what happened on Monday when that lady was killed?)
-
Paul Robison
I apologize, Rip76. What I'm asking y'all is: do conditons favor the formation of storng to severe thunderstorms friday and saturday?Rip76 wrote:Wut?Paul Robison wrote:What do the prospects look like for strong to damaging thunderstorms friday and saturday? (Remember what happened on Monday when that lady was killed?)
-
Andrew
- Site Admin
- Posts: 3441
- Joined: Wed Feb 03, 2010 9:46 pm
- Location: North-West Houston
- Contact:
A little more worried about heavy rains as the GFS continues its westward trend with the deteriorating ULL. A lot of the leftover mid level PVA will be west of the area allowing for good mid level lift. Mid levels look saturated too as moisture from the low sticks around through the weekend due to building ridges east and west of the area. Whatever storms do develop today into tomorrow will have very little movement as guidance suggests that storm motion will be less than 10kts. Something that will have to monitored especially if a MCS/MCC forms.
For Your Infinite Source For All Things Weather Visit Our Facebook
-
Paul Robison
Andrew wrote:A little more worried about heavy rains as the GFS continues its westward trend with the deteriorating ULL. A lot of the leftover mid level PVA will be west of the area allowing for good mid level lift. Mid levels look saturated too as moisture from the low sticks around through the weekend due to building ridges east and west of the area. Whatever storms do develop today into tomorrow will have very little movement as guidance suggests that storm motion will be less than 10kts. Something that will have to monitored especially if a MCS/MCC forms.
Ah, but the latest run of the NAMHIRES doesn't quite agree with the GFS, though. It's trending a little drier, though I will admit it is showing some heavy rain to the w/sw of the area. Still, it is something to be monitored.
-
Andrew
- Site Admin
- Posts: 3441
- Joined: Wed Feb 03, 2010 9:46 pm
- Location: North-West Houston
- Contact:
Paul Robison wrote:Andrew wrote:A little more worried about heavy rains as the GFS continues its westward trend with the deteriorating ULL. A lot of the leftover mid level PVA will be west of the area allowing for good mid level lift. Mid levels look saturated too as moisture from the low sticks around through the weekend due to building ridges east and west of the area. Whatever storms do develop today into tomorrow will have very little movement as guidance suggests that storm motion will be less than 10kts. Something that will have to monitored especially if a MCS/MCC forms.
Ah, but the latest run of the NAMHIRES doesn't quite agree with the GFS, though. It's trending a little drier, though I will admit it is showing some heavy rain to the w/sw of the area. Still, it is something to be monitored.
Hi-res models had (and will continue) trouble with this ULL as it moved through the first time. With such a low wavenumber (slow moving system), a lot of the hi-res models have issues resolving precipitation correctly. This is especially true for the NAM and NAM-Hi-RES. We will see what happens tomorrow, but the key for higher totals really depends on meso development.
For Your Infinite Source For All Things Weather Visit Our Facebook
-
srainhoutx
- Site Admin
- Posts: 19622
- Joined: Tue Feb 02, 2010 2:32 pm
- Location: Maggie Valley, NC
- Contact:
Morning Update from Jeff:
Upper level storm system responsible for the wet weather this week return this afternoon-Sunday.
System is currently spinning over southern Arkansas and will move WSW over the next 24 hours returning deep moisture and favorable dynamics to SE TX resulting in additional rounds of heavy rainfall.
Think best chance for thunderstorms today will be along and NE of a line from Columbus to Sugar Land to Freeport and then across much of the area on Saturday. Storm motions are forecast to slow down compared to Tuesday and Wednesday and given the moist air mass in place heavy to excessive rainfall will be possible both this afternoon and Saturday. Best chances for slow moving heavy rainfall appears to be on Saturday, but meso scale driving of these events is nearly impossible to determine where, when and how much will fall at any given time.
Additional rainfall amounts of 1-2 inches appears likely with isolated amounts up to 4 inches especially under slow moving storms or cell training.
Upper level storm system responsible for the wet weather this week return this afternoon-Sunday.
System is currently spinning over southern Arkansas and will move WSW over the next 24 hours returning deep moisture and favorable dynamics to SE TX resulting in additional rounds of heavy rainfall.
Think best chance for thunderstorms today will be along and NE of a line from Columbus to Sugar Land to Freeport and then across much of the area on Saturday. Storm motions are forecast to slow down compared to Tuesday and Wednesday and given the moist air mass in place heavy to excessive rainfall will be possible both this afternoon and Saturday. Best chances for slow moving heavy rainfall appears to be on Saturday, but meso scale driving of these events is nearly impossible to determine where, when and how much will fall at any given time.
Additional rainfall amounts of 1-2 inches appears likely with isolated amounts up to 4 inches especially under slow moving storms or cell training.
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey
Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity