July Weather Discussion

[wxdata]

Report- possible funnel cloud 7700 North Freeway

[Mr. T]

Quite the rapid change of weather for folks Downtown this evening... That area of storms decided to pulse right overhead and drag its feet through the heart of Houston.

This is a very good sign that the subsident ridge overhead has lost much of its grip over the area, and we should see a good coverage of rainfall the next few days.

[wxdata]

Vicious lightning in the Galleria area!!

[spadilly]

Pouring down rain here in spring valley.
No strong winds or anything, but a good heavy rain.

[wxdata]

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
812 PM CDT SAT JUL 17 2010

TXC157-201-180200-
/O.CON.KHGX.FF.W.0019.000000T0000Z-100718T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HARRIS TX-FORT BEND TX-
812 PM CDT SAT JUL 17 2010

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 900 PM CDT FOR...
EASTERN FORT BEND COUNTY IN SOUTHEAST TEXAS...
CENTRAL HARRIS COUNTY IN SOUTHEAST TEXAS...

* AT 805 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A THUNDERSTORM PRODUCING FLASH FLOODING NEAR RELIANT PARK.
HARRIS COUNTY OFFICE OF EMERGENCY REPORTED 1.56 INCHES OF RAIN
FELL IN ONLY 15 MINUTES WITH THE STORM NEAR RELIANT. WIDESPREAD
STREET FLOODING IS EXPECTED FROM THE MUSEUM DISTRICT SOUTHWESTWARD
TO SOUTHWEST CORNER OF THE BELTWAY 8 LOOP. THESE STORMS WILL
CONTINUE TO DRIFT WEST SOUTHWEST BUT SHOULD SLOWLY WEAKEN OVER THE
NEXT HOUR.

* LOCATIONS IN THE FLOOD WARNING INCLUDE BUT ARE NOT LIMITED TO THE
MEDICAL CENTER...MINUTE MAID PARK...HERMAN PARK...THE GALLERIA...
WEST UNIVERSITY PLACE...SPRING VALLEY...SOUTHSIDE PLACE...PINEY
POINT VILLAGE...HUNTERS CREEK VILLAGE...HOUSTON...HEDWIG VILLAGE
AND BELLAIRE.

[kayci]

Winds are picking up quite nicely here in Texas City... Complete cloud cover but no rain (ok, I did feel two drops). Rain welcome any time now please!

[Mr. T]

1.56" of rain in 15 minutes! Man, I would have loved to be under that thing as it crossed Downtown

[Mr. T]

It just matters where you put the rain bucket

Through 8 pm, IAH has recieved 2.02" of rain (the final total will be a bit higher as more rain has fallen at the airport after 8 pm). This puts the monthly total at IAH to 11.25". This has rocketed July 2010 to 4th wettest on record.

Also, today's record rainfall for the date is 0.97 in 1999. This was the lowest rainfall record for this month and has obviously been easily smashed by today's rain of over 2" at IAH.

[srainhoutx]

Makes you wonder what the next 96 hours has in store as HGX stated earlier.

Code: Select all

NWUS54 KHGX 180037
LSRHGX

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
737 PM CDT SAT JUL 17 2010

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0729 PM     TSTM WND GST     4 NNE ALDINE            29.97N 95.35W
07/17/2010  M0 MPH           HARRIS             TX   NWS EMPLOYEE

            60 MPH WIND GUST REPORTED AT INTERCONTINENTAL AIRPORT.

[wxdata]

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
856 PM CDT SAT JUL 17 2010


...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 900 PM CDT FOR...
EASTERN FORT BEND COUNTY IN SOUTHEAST TEXAS...
CENTRAL HARRIS COUNTY IN SOUTHEAST TEXAS...

* AT 849 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THE THUNDERSTORMS RESPONSIBLE FOR THE TORRENTIAL DOWNPOURS HAD
MOVED OUT OF THE FLASH FLOOD WARNING AREA TO THE SOUTHWEST.
HARRIS COUNTY OFFICE OF EMERGENCY REPORTED MORE THAN 2 INCHES AND
AS MUCH AS 3.3 INCHES OF RAIN FELL IN AN HOUR ALONG THE FANNIN
CORRIDOR FROM NEAR THE MUSEUM DISTRICT SOUTHWEST TO AROUND THE
SOUTHWEST CORNER OF THE 610 LOOP. STREET FLOODING IN THE AREA MAY
LINGER FOR SOME TIME YET.

* LOCATIONS IN THE FLOOD WARNING INCLUDE BUT ARE NOT LIMITED TO THE
MEDICAL CENTER...RELIANT PARK...MINUTE MAID PARK...HERMAN PARK...
THE GALLERIA...WEST UNIVERSITY PLACE...SPRING VALLEY...SOUTHSIDE
PLACE...PINEY POINT VILLAGE...HUNTERS CREEK VILLAGE...HOUSTON AND
HEDWIG VILLAGE.

[Ptarmigan]

It just matters where you put the rain bucket

Through 8 pm, IAH has recieved 2.02" of rain (the final total will be a bit higher as more rain has fallen at the airport after 8 pm). This puts the monthly total at IAH to 11.25". This has rocketed July 2010 to 4th wettest on record.

Also, today's record rainfall for the date is 0.97 in 1999. This was the lowest rainfall record for this month and has obviously been easily smashed by today's rain of over 2" at IAH.

The 2.02" of rain at IAH fell in 1 hour I think.
http://www.weather.gov/data/obhistory/KIAH.html

This wet July is more concerning to me. Most major hurricanes that make landfall happen from August to September and one in October, which was 1949. I found there is a correlation that wetter July's are more likely to see major hurricanes making landfall from August to October. Does wet July mean we are going to see a major hurricane make landfall? Only time can tell.

[TexasMetBlake]

Yeah, Alicia hit a week after very heavy rainfall across the area which contributed to the high number of trees that fell across the area.

BTW, we had an AWESOME double rainbow appear over the house. Amazing..

[txflagwaver]

We got zip here....zero, nada, nuttin....

[TexasMetBlake]

We got zip here....zero, nada, nuttin....

We got about 11 fat drops. That was it.

[Poltracker]

We got zip here....zero, nada, nuttin....

Same here

[Mr. T]

The 2.02" of rain at IAH fell in 1 hour I think.
http://www.weather.gov/data/obhistory/KIAH.html

This wet July is more concerning to me. Most major hurricanes that make landfall happen from August to September and one in October, which was 1949. I found there is a correlation that wetter July's are more likely to see major hurricanes making landfall from August to October. Does wet July mean we are going to see a major hurricane make landfall? Only time can tell.

Yup, I saw your post. It definitely makes sense to me.

To have a wet July like we have seen around here requires a constant flow off of the Gulf and upper level ridging to remain minimal and off to our north or east. For most of this month, we've seen high heights and ridging dominate the pattern across the SE. This has really heated up locations around the TN Valley and has driven record breaking heat into the big cities of the Northeast. This flow pattern has also helped keep a strong southerly fetch off of the Gulf with continued bouts of deep tropical moisture thanks to a weakness that has remained across Texas between two areas of upper highs to our east and west (though heights and subsidence did increase a bit last week, this appears to have been a quick breather between another active wet period for SE TX this week).

Because of this directional pattern, we have seen two tropical systems develop in the Gulf and head westward into Mexico. Ridging was felt overhead just enough to push these systems south of Texas, but not enough of a cap to keep abundant moisture from both Alex and TD #2 from heading into our area.

I don't see any reason why this upper level pattern will not continue for the next few weeks (dominate weather features in the summer tend to stick for a while, remember last year's dreadful heat and drought?), with upper highs dominating the pattern to our east and west and a weakness remaining across our area from time to time. So, if any tropical systems were to develop towards the end of this month, the relaxation of the upper level ridging to our north and east will need to be watched closely to see if any potential systems could possibly move further north into Texas.


BTW, it looks like today's rainfall total at IAH will stand at 2.23". IAH's rain bucket was the lucky ticket tonight, as this event was very isolated with mainly locations running along the Hwy 59 corridor seeing the heavy rain today, while residents outside these areas saw nothing (as some of you have reported ) except for isolated coastal areas that had help along the seabreeze

For now, another wet week looks to be in the books for SE TX (though perhaps a brief break in coverage on tuesday between two surges of tropical moisture).

[Mr. T]

This day 4 upper level map from the 0z GFS is a great example of the pattern I described in the post above. An upper high dominates the pattern across the SE and East Coast with 594 dm+ heights being felt across the SE leading to baking heat for those areas. This ridge to our east and the flow around it is helping to create a deep southeasterly fetch of tropical moisture into the Gulf of Mexico. Because we reside right on the western edge of this ridge, our temperatures stay in our typical July 90s but with an enhanced chance of heavy tropical rains as continued surges of tropical moisture arrive into our area.

Why was last year so hot and dry? Well, look at where the upper level ridging decided to plant itself:
http://www.meteo.psu.edu/~gadomski/NARR/2009/us0625.php

That is the upper level analysis for June 25th of last year. Notice how high heights are focused across Texas and just to the west, while lower heights reside across Florida and the East Coast. Because of this, the flow around the ridge was rather stagnant but mainly out of the north, shutting off the flow from the Gulf and allowing big time heat to overspread the area from the west. Meanwhile, locations to our north and east witnessed quite a cool, wet pattern thanks to an active storm track and northwesterly flow out of Canada which invaded the Eastern States for pretty much the entire summer of 2009.

Fast foward about 15 days and we saw the same depressing pattern continue:
http://www.meteo.psu.edu/~gadomski/NARR/2009/us0710.php

Big upper high over Texas, lower heights and much cooler, wetter weather just to our east. Those low heights over the SE and especially Florida are a big no no. No flow from the Gulf in the summer = no rain


If you are in Houston in the heart of summer and you want rain, you do NOT want to see big ridging overhead or just to our west. A big SE ridge is a much more happy pattern, as we will see throughout the week. Unfortunately, this means many folks have to deal with heat they are not used to across the East and especially Northeast, but it's either feast or famine if you're talking about the weather. Last summer, everywhere outside of Texas feasted on a cool, wet summer while we baked in a hot drought. We've flipped the tides a bit this year (though the dry June was a bit of a scare), with a much more wet pattern focused around our region (though still hot)

[srainhoutx]

HGX certainly believes that heavy rainfall chances will be the main concern the next couple of days. Convective temps in the low to mid 80's and PW's in the 2.3-2.5 range would certainly suggest a potential for some heavy rainfall. Hopefully a bit more wide spread than last evening.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
924 AM CDT SUN JUL 18 2010

.DISCUSSION...
WEAK SURFACE HIGH PRESSURE WAS LOCATED JUST WEST OF THE FORECAST
AREA THIS MORNING. THE 12Z UPPER AIR SOUNDINGS AT BOTH KLCH AND
KCRP SHOWED PW/S OF 2.3 TO 2.5 ACROSS SE TX. SURFACE BOUNDARIES
CONSISTED OF OUTFLOWS THIS MORNING FROM SHOWERS AND THUNDERSTORMS
MOVING ACROSS THE CWA BETWEEN CROCKETT AND CONROE. THERE WAS ALSO
AN MCV NEAR CLL. HOWEVER...IT WILL LIKELY BE TO THE WEST DURING
THE AFTERNOON. THE DEEP LAYER MOISTURE WAS MOVING INTO THE AREA
FROM THE EAST.

TWEAKED THE POPS UP FOR THE NORTHERN COUNTIES FOR THE REMAINDER OF
THE MORNING. FOR THIS AFTERNOON...KEPT THE RAIN CHANCES THE SAME
BUT WENT WITH LOCALLY HEAVY RAINFALL FOR MOST OF THE FORECAST AREA
GIVEN THE AIRMASS MOISTURE CONTENT. ALSO UPPED THE RAIN CHANCES
FOR THE EVENING...MAINLY SOUTH OF THE INTERSTATE 10 CORRIDOR...AND
INCLUDED LOCALLY HEAVY RAINFALL FOR THOSE LOCATIONS.

[srainhoutx]

At least 2 inches of rainfall over the past 30-40 minutes at my location. Street flooding is becoming a real problem up here in NW Harris County.

[srainhoutx]

Flood Advisory will probably be needed shortly for Western Harris County.