JULY 2015:Heat Advisory Expanded Across Metro Houston

[Katdaddy]

Getting a tropical shower in League City. .31" so far which I will gladly take.

[Paul Robison]

No threat of any tropical troubles for the Western Gulf at this time and only a very slim if any chance of rainfall for a very lucky few for the next week.

One thing does concern me about the split in the High pressure ridge on Aug.1, (if that happens). If we have a system brewing in the E Gulf next week and SE TX. lies between two ridges, won't that be a welcome mat for any building TC?

[srainhoutx]

No change in the sensible weather forecast into the weekend. Hot and dry weather continues as the upper ridge remains in control across Texas and Louisiana other than an isolated heat of the day seabreeze shower or storm for a lucky few. No tropical development will occur in the Gulf into next week. Saharan Dust and wind shear are not favorable for any tropical development across the Gulf of Mexico or the Western Caribbean Sea. The only area that may see potential tropical development is off the SE United States.

[wxman57]

I plotted the 12Z Euro 500mb heights. Euro says building ridge right over Texas through the weekend. Temperatures approaching or topping 100F locally. Time to get out and enjoy it! I'm taking Friday off to finish washing my house and planning along bike ride on Saturday.

[BlueJay]

I do like the heat but it can be dangerous. (Be safe wxman57!)
Stay cool everyone!

[srainhoutx]

HOT HOT HOT. That spells our sensible weather forecast for the Weekend. If we reach 100F, it will be the first time in 2 years that we have hit the Century Mark. Be careful this weekend for those with outdoor activities. Wear plenty of sunscreen, drink plenty of water, get in the shade during the heat of the day when possible and check on the elderly. There is a high chance that at least potions of Texas will be under a Heat Advisory this weekend including Metro Houston. Stay safe and keep cool!

[srainhoutx]

Briefing from Jeff regarding the Heat and Fire Weather:

Strong upper level high pressure dome remains anchored over TX with generally hot and dry conditions. A few afternoon showers and thunderstorms were able to develop yesterday afternoon over the coastal sections of the area, but general subsidence from the ridge overhead will continue to mitigate storm formation.

Grounds have continued to dry and vegetation is slowly turning from a deep green to more yellowish green with some fine fuels showing much more significant “lack of rainfall” stress. This is slowly allowing surface air temperatures during the afternoon hours to creep upward. Ridge aloft increases slightly this weekend and expect high temperatures in the 97-100 degree range across the area. Afternoon heat index values will be nearing 105-108 during peak heating this weekend and we may be very near heat advisory criteria Saturday and Sunday…heat index of 108 or greater over much of the region.

Greatest (10-20%) rain chances will be today with lower chances Thursday-Monday. Longer term pattern shows ridge remaining in place over the southern plains, but shifting slightly northward toward the end of next week. This might allow lowering heights aloft and a weak cool front to drift southward from off the SE US coast into the NE Gulf of Mexico. Locally lowering heights will help reduce temperatures and bring rain chances along the seabreeze back toward summer normals. Potential for the front to stall over the SE US coast and eastern Gulf of Mexico is leading to global forecast models suggesting that surface low pressure may attempt to develop in/near FL and this area should be a favorable breeding ground for tropical cyclone formation from the middle of next week onward.

Fire Weather:
KBDI values have increased into the 400-500 range over much of SE TX with a few areas over Houston and Walker Counties nearing 700. Fine fuels have certainly dried since late June with a significant lack of rainfall in the last 3 weeks and very warm afternoon temperatures. Afternoon mixing is resulting in fairly low afternoon RH especially north of I-10 prior to the onset of the seabreeze moist layer from the Gulf of Mexico. Potential for wildfire activity especially fine fuel grass fires in slowly increasing across the area especially north of HWY 105.

[Paul Robison]

Briefing from Jeff regarding the Heat and Fire Weather:

Strong upper level high pressure dome remains anchored over TX with generally hot and dry conditions. A few afternoon showers and thunderstorms were able to develop yesterday afternoon over the coastal sections of the area, but general subsidence from the ridge overhead will continue to mitigate storm formation.

Grounds have continued to dry and vegetation is slowly turning from a deep green to more yellowish green with some fine fuels showing much more significant “lack of rainfall” stress. This is slowly allowing surface air temperatures during the afternoon hours to creep upward. Ridge aloft increases slightly this weekend and expect high temperatures in the 97-100 degree range across the area. Afternoon heat index values will be nearing 105-108 during peak heating this weekend and we may be very near heat advisory criteria Saturday and Sunday…heat index of 108 or greater over much of the region.

Greatest (10-20%) rain chances will be today with lower chances Thursday-Monday. Longer term pattern shows ridge remaining in place over the southern plains, but shifting slightly northward toward the end of next week. This might allow lowering heights aloft and a weak cool front to drift southward from off the SE US coast into the NE Gulf of Mexico. Locally lowering heights will help reduce temperatures and bring rain chances along the seabreeze back toward summer normals. Potential for the front to stall over the SE US coast and eastern Gulf of Mexico is leading to global forecast models suggesting that surface low pressure may attempt to develop in/near FL and this area should be a favorable breeding ground for tropical cyclone formation from the middle of next week onward.

Fire Weather:
KBDI values have increased into the 400-500 range over much of SE TX with a few areas over Houston and Walker Counties nearing 700. Fine fuels have certainly dried since late June with a significant lack of rainfall in the last 3 weeks and very warm afternoon temperatures. Afternoon mixing is resulting in fairly low afternoon RH especially north of I-10 prior to the onset of the seabreeze moist layer from the Gulf of Mexico. Potential for wildfire activity especially fine fuel grass fires in slowly increasing across the area especially north of HWY 105.

Another Claudette in the Atlantic, Srainhoutex?

[srainhoutx]

No change during the weekend regarding the sensible weather forecast across our Region, but changes may be lurking as we end July. The 00Z Global Ensembles are beginning to suggest the pesky upper ridge that has been stationary over Texas will finally shift West mid next week and become anchored across the Great Basin/Desert SW as a trough digs South into the Mississippi Valley all the way to the Northern Gulf. Such a pattern change would increase our rain chances once again and shift the subsidence of the upper ridge into California, Nevada, Utah and Arizona. It also would allow for storm chances to increase as a rather strong shortwave (upper air disturbance) tracks inland in the Pacific NW and dive SE in a NW flow aloft. The ensembles are indicating that pressure will lower across the Eastern half of Texas into Louisiana and perhaps an Easterly wave traversing West along the Northern Gulf Coast in the Medium to Longer Range. Tropical development outside of a potential disturbance off the SE Coast of the United States moving NE and safely out to sea looks unlikely as Saharan Dust once again moves across the Caribbean Sea into the Western Gulf prohibiting tropical develop in our back yard. There are some indications that the Eastern and Central Pacific will see the potential for tropical development possibly nearing the Hawaiian Islands in the longer range which raises an eye because I will be traveling to Honolulu around mid August for a long anticipated 'bucket list' vacation on Waikiki Beach. I am chuckling because Dr. Rick Knabb and Bill Read were giving me a hard time back at the Houston/Galveston Hurricane Workshop regarding the active Central Pacific Hurricane Season and that I may have a 'front row seat' for a Pacific Hurricane during my vacation. I told them I would just invite Hurricane Josh to join me since I will have an Ocean Front Room with an excellent view... Perhaps someone would like to start an August Topic since it appears the 'Dog Days' of July will be ending on a potential pattern changing note and that likely will carry into the start of the Month of August.

[txflagwaver]

Got up and out early this morning to water the plants...it was still in the 70's...even had the first cup of coffee outside on the swing.

[tireman4]

Stay safe out there folks. This will be a hot weekend. Monitor your fluid intake and take it easy.

[tireman4]

FXUS64 KHGX 250858
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
358 AM CDT SAT JUL 25 2015

.DISCUSSION...
LATEST GUIDANCE STILL POINTS TO HOT & DRY WX PERSISTING OVER THE
WEEKEND. AREAS GENERALLY ALONG/SOUTH OF I-10 WILL PROBABLY
CONTINUE TO SEE SOME HEAT INDICES BETWEEN 105-108 FOR A BRIEF
PERIOD OF TIME COINCIDING W/ SEABREEZE & PEAK HEATING. REST OF
THE REGION HAS SEEN DEWPOINTS MIX OUT DURING THE AFTN AND SEE NO
REASON THAT WON`T CONTINUE.

GOOD NEWS IS THAT LARGE UPPER RIDGE CURRENTLY CENTERED OVER THE
PANHANDLE WILL SLOWLY TRACK NE EARLY NEXT WEEK. AS IT DOES
SO...FLOW OVER SE TX WILL GRADUALLY FLATTEN & TRANSITION TO THE
EAST. THIS SHOULD ALLOW AT LEAST SLIGHT CHANCES OF SEABREEZE
ACTIVITY AND/OR DISTURBANCES TO TRIGGER A FEW SHRA/TSRA. CHANCES
DON`T LOOK PARTICULARLY HIGH BUT AT LEAST IT`S NOT ZERO. SLIGHTLY
INCREASED MOISTURE/CLOUDS & MORE OF A SE WIND SHOULD AT LEAST KNOCK
A DEGREE OR THREE OFF HIGHS THOUGH.

RIDGE MEANDERS INTO THE SW STATES DURING THE SECOND HALF OF THE
WEEK AND THEN EXPANDS NORTHWARD. SUBSEQUENT DIGGING EASTERN TROF
LOOKS TO PROVIDE A FAVORABLE PATTERN FOR A WEAK FRONTAL BOUNDARY
TO SLIDE INTO THE STATE & QUITE POSSIBLY INTO PORTIONS OF SE TX
FRI/SAT. BOTH GFS & ECMWF MOSTLY AGREE ON THIS SCENARIO.
HOPEFULLY IF AVAILABLE MOISTURE COOPERATES WE`LL SEE BETTER SHOTS
OF RAIN WITH BOTH SEABREEZE AND FRONTAL BOUNDARY BEING IN PLAY. 47

&&

[ticka1]

This heat is horrible - cant do ANYTHING outdoors. Prayers for all thos that have to work out in the heat -stay cool and hydrated. If you dont have to be outside stay indoors. Please check on the elderly and make sure your outdoor pets have plenty of water and somewhere shady to try to keep ccol.

[tireman4]

Relief in sight for next weekend?

00
FXUS64 KHGX 252052
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
352 PM CDT SAT JUL 25 2015

.DISCUSSION...
HOT AND DRY CONDITIONS PERSIST ACROSS THE REGION THIS
AFTERNOON... WITH HEAT INDICES ALONG THE COAST IN THE 102 TO 107
RANGE AS OF 3 PM CDT. THE UPPER LEVEL RIDGE CONTINUES TO MAINTAIN
CONTROL OVER THE SOUTHERN PLAINS WITH 12Z RAOBS SHOWING IT
CENTERED OVER THE TEXAS/OKLAHOMA PANHANDLES. WITH LITTLE CHANGE IN
THE OVERALL PATTERN BETWEEN YESTERDAY AND TODAY... SIDED WITH A
PERSISTENCE FORECAST FOR TONIGHT. EXPECT CLEARING SKIES THIS
EVENING GIVING WAY TO PATCHY FOG/LOW STRATUS AGAIN WEST OF
INTERSTATE 45 EARLY SUNDAY MORNING WITH LOW TEMPERATURES RANGING
FROM THE MID 70S INLAND TO LOW 70S ALONG THE COAST.

THE RIDGE/S PROXIMITY TO THE REGION WILL HELP PROMOTE A HOT AND
MOSTLY DRY PATTERN THROUGH MID-WEEK. HOWEVER... WITH THE CENTER OF
THE UPPER LEVEL RIDGE WELL NORTH OF THE REGION... WEAKNESSES
ROTATING AROUND THE RIDGE MAY BE ENOUGH TO PROVIDE AT LEAST AN
ISOLATED AFTERNOON RAIN CHANCE ON SUNDAY AND MONDAY. SOME OF THE
HIGHER RESOLUTION GUIDANCE... NAMELY THE TTU-WRF/ARW/NMM... SHOWS
ISOLATED SHOWERS AND STORMS PUSHING INTO THE FAR EASTERN ZONES
SUNDAY AFTERNOON AND EVENING AS ONE OF THESE DISTURBANCES REACHES
THE AREA. HOWEVER... CARRYING POPS JUST BELOW MENTIONABLE LEVELS
FOR NOW GIVEN UNCERTAINTY ON THE ACTUAL EVOLUTION OF THIS FEATURE.
OTHERWISE... TEMPERATURES ON SUNDAY WILL BE HOT AGAIN WITH HEAT
INDICES AT ISOLATED LOCATIONS ALONG THE UPPER TEXAS COAST PEAKING
IN THE 105 TO 108 DEGREE RANGE.

A LESSENED INFLUENCE OF THE UPPER RIDGE COMBINED WITH
PRECIPITABLE WATER VALUES APPROACHING 1.8 TO 2 INCHES MONDAY
AFTERNOON WILL PROVIDE SOME OF HIGHEST RAIN CHANCES FORECAST IN
SEVERAL DAYS FOR SOUTHEAST TEXAS... WITH 20 POPS ALONG THE SEA
BREEZE. ADDITIONALLY... WE COULD SEE HIGH TEMPERATURES RUN A FEW
DEGREES LOWER THAN WHAT/S BEEN OBSERVED THIS WEEKEND IN THE
MONDAY/TUESDAY TIMEFRAME GIVEN INCREASING MOISTURE AND SLIGHTLY
LOWER HEIGHTS ALOFT.

A PASSING NORTHERN PLAINS UPPER LOW IS EXPECTED TO SHIFT THE
RIDGE TOWARDS THE ARKLATEX BY THE MIDDLE OF THE WEEK AND THEN BACK
TOWARDS THE DESERT SOUTHWEST BY THE END OF THE WEEK. AS THIS LOW
SWINGS ACROSS THE EASTERN CONUS... MEDIUM RANGE GUIDANCE SHOWS A
WEAK COLD FRONT APPROACHING THE REGION WITH INCREASED RAIN CHANCES
BY THE END OF THE WEEK AS THIS FRONT APPROACHES SOUTHEAST TEXAS.

[tireman4]

00
FXUS64 KHGX 261544
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1044 AM CDT SUN JUL 26 2015

.UPDATE...
MORNING SURFACE ANALYSIS REVEALED TWO BOUNDARIES NEAR THE
REGION... WITH THE FIRST LOCATED NEAR GALVESTON ESE TOWARDS
PLATFORM KGHB /ABOUT 160 MILES SE OF CAMERON...LA/. THE SECOND WAS
LOCATED STRETCHING FROM NORTHEAST TEXAS TOWARDS THE LOUISIANA
COAST. ONGOING SHOWERS AND THUNDERSTORMS ALONG THE FIRST BOUNDARY
CONTINUE TO PUSH OUT INTO THE CENTRAL GULF OF MEXICO... WITH AN
ISOLATED STORM OR TWO DEVELOPING ALONG IT AND POSSIBLY CLIPPING
THE COASTAL WATERS THROUGH THE REMAINDER OF THE MORNING HOURS.

THE SECOND BOUNDARY... PER HIGH RESOLUTION GUIDANCE...
APPEARS TO BE A FOCUSING MECHANISM FOR ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS LATER TODAY GENERALLY EAST OF INTERSTATE
45. GIVEN THE AMPLE MOISTURE PRESENT /LAKE CHARLES REPORTING 2.3
INCH PWAT AND GOES SOUNDER IMAGERY SHOWING THIS MORE MOIST AIRMASS
PUSHING SOUTHWEST/ AND MORNING SOUNDINGS SHOWING CONVECTIVE
TEMPERATURES AROUND 95 DEGREES THIS AFTERNOON... THIS SOLUTION
SEEMS REASONABLE. THE MAIN QUESTION WILL BE HOW FAR WEST INTO THE
FORECAST AREA THIS ACTIVITY WILL BE ABLE TO MOVE WITH INCREASING
SUBSIDENCE FROM THE UPPER RIDGE. ORGANIZED STORMS ARE NOT
ANTICIPATED GIVEN LOW SHEAR BUT FORECAST SOUNDINGS SHOW A VERY DRY
SUBCLOUD LAYER... CREATING AN ISOLATED GUSTY WIND THREAT MAINLY
OVER THE FAR EASTERN ZONES.

HEAT WILL ALSO BE A CONCERN THIS AFTERNOON AS HEAT INDEX VALUES
TOP OUT IN THE 101 TO 107 RANGE AND HAVE REISSUED AREA-WIDE
SPECIAL WEATHER STATEMENT COVERING THIS HAZARD. CURRENT FORECAST
IS ON TRACK AND NO UPDATES ARE PLANNED.

HUFFMAN

&&

.PREV DISCUSSION... /ISSUED 347 AM CDT SUN JUL 26 2015/

DISCUSSION...
GOES SOUNDER IMAGERY SHOWS AN AXIS OF HIGHER PW AIR MOVING WWD
FROM LOUISIANA AND OFFSHORE TOWARD SE TX. THIS AREA HAS BEEN
ASSOCIATED W/ SOME CONVECTION WELL TO OUR EAST THE PAST COUPLE
DAYS...MAKING IT INTO CNTL LA YESTERDAY. GIVEN THAT WE HAD A FEW
ISOLATED CELLS YDAY...SUSPECT WE COULD SEE SOME MORE TODAY ESP IN
THE SE HALF OF THE CWA WITH THE ARRIVAL OF DEEPER MOISTURE. WILL
STILL NEED TO OVERCOME QUITE A BIT OF SUBSIDENCE BUT FELT LIKE
ADDING MENTIONABLE POPS IN THE FCST IS PROBABLY WARRANTED. HRRR &
TX TECH WRF BOTH SHOWING THIS POSSIBILITY AS WELL.

OTHERWISE...CONTINUED HOT & MUGGY THIS WEEK. HIGHS WILL PROBABLY
MODERATE A FEW DEGREES AS UPPER RIDGE SLIGHTLY WEAKENS/FLATTENS
OVER THE UPPER TX COAST AS ITS CENTER MIGRATES A BIT FURTHER NE
INTO THE MIDWEEK PERIOD. MAY SEE A PASSING IMPULSE OR TWO MOVE
OVERHEAD UNDERNEATH THE RIDGE THAT MAY HELP GENERATE A FEW CELLS
FROM TIME TO TIME...BUT OVERALL COVERAGE SHOULD REMAIN MOSTLY
ISOLATED THRU THURS.

RAIN CHANCES SHOULD INCREASE FRI-SUN AS THE RIDGE REPOSITIONS
ITSELF OVER THE WESTERN STATES...DEEP GULF MOISTURE MOVES BACK
IN...AND POSSIBLY A DIFFUSE FRONT AND/OR SEABREEZE PROVIDES A
FOCUS FOR HOPEFULLY BETTER AREAL PRECIP CHANCES THAN WE`VE SEEN IN
A WHILE. ADVERTISED POPS IN OUR FCST FOR THAT TIME PERIOD COULD BE
TOO LOW...BUT PREFER TO NUDGE THEM UP W/ TIME AS CONFIDENCE
IMPROVES - VERSUS THE OPPOSITE. 47

[Rip76]

I was just to ask about that little area of weather south of Louisiana.
Wondering if it would/could make it this far, or fire off something ahead of it.

[srainhoutx]

Afternoon briefing from Jeff:

Upper level ridge which has dominated TX weather since the first week of July is starting to give some ground and with that cooler temperatures and better chances for rainfall.

Upper level heat ridge which has been anchored over TX for weeks has shifted just enough to the NNE to allow for a weak disturbance and deeper moisture to arrive into SE TX from the east. Tail end of a weak boundary that has drifted into the northern Gulf and across central FL and then extends WNW toward the SW LA coast. LCH morning sounding came in with a respected 2.3 in PWS, but there is a strong moisture gradient over SE TX with CRP sounding showing 1.6 in. Deepest moisture is along and E of I-45, but spreading westward. Radar from Houston, Lake Charles, and Fort Polk all show at least a couple of westward moving boundaries from storms yesterday and overnight over SE LA which have migrated W to WSW. Visible images show these boundaries and their associated enhanced cumulus growth. HRRR and TX TECH models are in agreement on storms developing over W LA/Sabine River region and moving WSW to SW on the southern side of the upper level ridge now centered over NE OK. Expect storms to develop on old outflow boundaries once convective temperatures in the mid 90’s are reached. Sub cloud layer is somewhat dry and will support gusty downburst winds as is common with SW moving thunderstorms this time of year. Main question is how far SW will storms be able to penetrate into the area of drier air and subsidence which is clearly noted over C TX. Think areas east of I-45 have the greatest chances for afternoon and evening thunderstorms with chances quickly dropping west of I-45. Recently…within the last 15 minutes storms have begun to form over Newton, Co TX which gives support to the model guidance suggesting isolated to scattered late day activity.

As for the heat…BUSH IAH topped 99 on Saturday…the hottest of 2015. Afternoon heat index values continue to bump up against heat advisory criteria of 108, but are not widespread enough for an official advisory. Most areas are maxing out in the 103-106 range for a few hours between 3-6pm each day. While it is hot…it is late July…and high temperatures are only running a couple degrees above average.

Could see some additional activity on Monday with the upper ridge remaining just north of the region. Will not go any higher than 20% since subsidence will still need to be overcome and would like to see how this afternoon plays out and just how for storms are able to move into SE TX.

Upper ridge builds back SW into TX mid week and then on to the SW US by late week into next weekend as a strong northern stream short wave drives into the Midwest and helps carve out a deep eastern US trough. With the ridge building west this opens the door for a cool front to move down the plains and toward SE TX Friday-Sunday. Boundary will likely become diffuse as it nears the region, but will certainly be able to work with increasing moisture to produce the best chance of rain the area has seen in 3-4 weeks. Increased cloud cover and thunderstorms will help cool afternoon highs away from the upper 90’s and return heat index values to more manageable levels.

Suspect this boundary/trough axis will likely migrate off the Gulf coast and into the northern Gulf waters by this time next week. This may allow for a brief period of offshore winds and slightly lower dewpoints (less humid). Such a trough would need to be monitored for any sort of tropical system formation since it will be early August over the northern Gulf of Mexico.

[Rip76]

/\ - that's what I was trying to say.

Thanks Jeff.

[Katdaddy]

The SW LA outflow boundary is slowly pushing into SE TX but will weaken as the Summer heat begins to decrease. If you look E and NE of Houston this evening you will see the high cirrus clouds. Perhaps a 9PM gust front if you are lucky along and E of the I-45 Gulf Freeway corridor.

[Rip76]

Seems to happen a lot with storms coming in from the East.