September Weather Discussion

[tireman4]

I just wanted to make folks feel a little better. Here are the normals for September.

September Temperature and Precipitation Normals (1971-2000)
and Extremes for Houston (through 2007)
(last updated 7/11/08)

---------------TEMPERATURE ------------------- ----- PRECIPITATION -----
NORMAL RECORD LOW RECORD HIGH RECORD CUMULATIVE PCPN
MAX MIN MAX YEAR MAX MIN YEAR MIN PCPN DAILY YEARLY
---------------------------------------------- -------------------------
1 92 72 107 2000 78 1970 63 1915 80 1962 2.22 1892 0.14 31.27
2 92 71 104 2000 79 1984 60 1893 79 1964 1.81 1969 0.28 31.41
3 92 71 105 2000 73 1974 60 1987 80 1985 3.20 1957 0.42 31.55
4 92 71 109 2000 76 1974 59 1974* 80 1962 2.75 1973 0.56 31.69
5 92 71 108 2000 75 1967 55 1891 80 1963 2.07 1973 0.70 31.83

6 92 71 99 1909 76 1918 56 1974 80 1963 2.90 1896 0.84 31.97
7 91 71 98 1963 76 1921 59 1891 78 1926 4.55 1913 0.98 32.11
8 90 71 100 1907 78 1957 58 1988* 79 1949 0.87 1962 1.12 32.25
9 90 71 100 1909 75 1974 59 1988 80 1962 4.22 1900 1.26 32.39
10 90 71 99 1993 73 1948 59 1988 78 1964 1.82 1998 1.40 32.53

11 90 71 99 1893 74 1894 56 1907 78 1965 4.81 1998 1.54 32.67
12 90 70 101 1909 77 1892 56 1907 79 1982 2.25 2003 1.68 32.81
13 89 69 98 1912 76 1894 56 1907 80 1993 2.29 1963 1.82 32.95
14 89 69 97 1918 67 1913 55 1902 81 1962 3.74 1919 1.96 33.09
15 89 69 98 1980 76 1993 55 1892 79 1962 3.23 1919 2.10 33.23

16 89 69 98 1995 75 1922 53 1979 79 1992 1.72 1941 2.24 33.37
17 89 68 100 1995 69 1943 55 2000 79 2006 1.85 1968 2.38 33.51
18 89 67 99 1927 71 1943 54 2000* 79 1988 2.53 1908 2.53 33.66
19 89 67 97 1995 70 1971 51 1981 78 1965 6.92 1979 2.68 33.81
20 89 67 99 1999 68 1971 54 1901 79 1924 7.66 1976 2.83 33.96

21 88 67 100 2005 70 1983 53 1983 79 1964 3.07 1958 2.98 34.11
22 88 66 100 2005 67 1995 49 1983 81 2006 3.14 1965 3.13 34.26
23 88 66 96 1993* 72 1928 49 1999 79 2000 2.37 1941 3.28 34.41
24 88 66 95 2000* 72 2001 48 1975 78 1945 2.22 1933 3.43 34.56
25 87 66 99 2005 71 1957 50 1994* 78 1958 3.05 1906 3.58 34.71

26 87 65 99 2005 64 1889 49 2000 79 2005 2.86 1896 3.73 34.86
27 87 65 100 2005 71 1942 45 1942 78 2005 3.46 1944 3.88 35.01
28 87 65 98 1998 68 1936 48 1909 79 1959 1.25 1902 4.03 35.16
29 87 65 95 1998 67 1984 47 1908 78 1955 2.51 1958 4.18 35.31
30 86 64 95 1998 67 1985 47 1890 78 1986 2.55 1913 4.33 35.46

* indicates a record that has been tied in a previous year

September Normals
high: 89.3
low: 68.4
mean temperature: 78.9
rainfall: 4.33"
heating DD: 0
cooling DD: 396



http://www.srh.noaa.gov/hgx/?n=climate_iah_normals_sep










http://www.srh.noaa.gov/hgx/?n=climate_iah_normals_sep

[ticka1]

It can't get here fast enough. Looking forward to the heat ridge breaking in September (hopefully - keeping fingers crossed).

[tireman4]

Any fronts coming in the distant future?

[unome]

http://www.hpc.ncep.noaa.gov/basicwx/day0-7loop.html

[srainhoutx]

Looks like we have a boundary setting up to our N and W. Storm motion appears very slow so heavy rainfall rate may well occur under those storms.

[srainhoutx]

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
504 PM CDT THU SEP 2 2010

TXZ210-211-022300-
AUSTIN-COLORADO-
504 PM CDT THU SEP 2 2010

...STRONG THUNDERSTORM IN EASTERN COLORADO AND CENTRAL AUSTIN
COUNTIES...

AT 458 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR EAGLE LAKE...MOVING NORTH AT 20 MPH.

FREQUENT CLOUD TO GROUND LIGHTNING AND BRIEF MODERATE DOWNPOURS ARE
POSSIBLE WITH THIS STORM.

LOCATIONS IN THE PATH OF THIS STORM INCLUDE...NEW ULM...CAT SPRING...
EAGLE LAKE...AND BELLVILLE.

[srainhoutx]

FLOOD ADVISORY
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
540 PM CDT THU SEP 2 2010

TXC015-089-022345-
/O.NEW.KHGX.FA.Y.0075.100902T2240Z-100902T2345Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
AUSTIN TX-COLORADO TX-
540 PM CDT THU SEP 2 2010

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED AN

* URBAN AND SMALL STREAM FLOOD ADVISORY FOR...
CENTRAL AUSTIN COUNTY IN SOUTHEAST TEXAS...
EXTREME NORTHEASTERN COLORADO COUNTY IN SOUTHEAST TEXAS...

* UNTIL 645 PM CDT

* AT 539 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
VERY HEAVY RAIN WAS FALLING NEAR CAT SPRING. 3 INCHES OF RAIN HAS
FALLEN IN THE LAST 90 MINUTES OVER THE ADVISORY AREA. THE STORM IS
NEARLY STATIONARY AND WILL LIKELY RAIN ITSELF OUT AND DISSIPATE BY 6
PM...HOWEVER ANOTHER HALF TO ONE INCH OF RAIN COULD FALL BEFORE THE
STORM ENDS.

[sleetstorm]

How much longer will daytime highs in the ninties and nighttime lows in the mid to upper seventies continue? What do all of the computer models show?

[tireman4]

Climo suggests September 13. Actuality maybe different.

[srainhoutx]

FLOOD ADVISORY
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
351 PM CDT SAT SEP 4 2010

TXC157-042245-
/O.NEW.KHGX.FA.Y.0076.100904T2051Z-100904T2245Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
FORT BEND TX-
351 PM CDT SAT SEP 4 2010

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED AN

* URBAN AND SMALL STREAM FLOOD ADVISORY FOR...
NORTHERN FORT BEND COUNTY IN SOUTHEAST TEXAS...

* UNTIL 545 PM CDT

* AT 347 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
VERY HEAVY RAIN WAS FALLING NEAR FULSHEAR.

HEAVY RAIN IS EXPECTED TO CONTINUE OVER NORTHERN FORT BEND COUNTY IN
THE FULSHEAR AREA AND AREAS BETWEEN FULSHEAR AND PECAN GROVE AND
RICHMOND.

[kayci]

ok, so now I'm jealous.

[djjordan]

not getting much here at my house.... a sprinkle or two that's about it .... looks like these storms are merging over western Ft. Bend County ....

[srainhoutx]

Enjoy the wonderful weather today. Tomorrow and into Wednesday look rather wet for some areas...we are following the Gulf disturbance in Hurricane Central for those that are interested...

FXUS64 KHGX 051608
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1108 AM CDT SUN SEP 5 2010

.UPDATE...
MORNING FORECAST UPDATE.

&&

.DISCUSSION...
15Z SFC ANALYSIS SHOWS SFC RIDGE OVER OHIO RIVER VALLEY AND ITS
AXIS STRETCHING BACK TO THE ARKLATEX. LEE TROUGHING CONTINUES TO
DEEPEN ALONG THE HIGH PLAINS AND W TX. STALLED FRONTAL BOUNDARY
JUST INLAND AND ALONG THE UPPER TX COAST SHOULD CONTINUE TO
DISSIPATE TODAY. SOUTH OF THE BOUNDARY DEEP MOISTURE REMAINS
ALTHOUGH PRECIP WATER HAS DROPPED TO AROUND 1.6 INCHES. SATELLITE
IMAGERY STILL SHOWS CLUSTER OF THUNDERSTORMS IN THE SW GULF/BAY
OF CAMPECHE WHICH WILL BEAR WATCHING.

ONLY FORECAST CHANGES THIS MORNING WILL BE TO KEEP 2O POPS ALONG
THE COAST FOR ANY SEA BREEZE ACTIVITY WHERE THERE IS HIGHER
MOISTURE. DRIER AIR HAS PUSHED A LITTLE FARTHER SW OVERNIGHT BUT
NOT ENOUGH TO KEEP POPS OUT OF THE FORECAST. TROPICAL MOISTURE
SHOULD BEGIN TO RETURN LATER TONIGHT AS LLJ INCREASES IN RESPONSE
TO SFC LOW FORMING IN THE PLAINS. FORECAST REMAINS ON TRACK WITH
INCREASING THUNDERSTORM CHANCES THROUGH THE DAY MONDAY.

[srainhoutx]

Looks like a rather active period ahead. Those that would like to follow the progress of TS Hermine can join us in Hurricane Central.

000
FXUS64 KHGX 060901
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
401 AM CDT MON SEP 6 2010

.DISCUSSION...
NOT MUCH CHANGE TO THE ONGOING FCST PACKAGE. MOISTURE WILL RAPIDLY
INCREASE TODAY....GOING FROM THE CURRENT 1" WELL INLAND TO 2" AT
THE IMMEDIATE COAST ALL THE WAY TO 2-2.6" RESPECTIVELY. LOOKING
FOR INCREASING PRECIP COVERAGE THRU THE DAY...BECOMING SCT WELL
INLAND TO WIDESPREAD JUST OFF THE COAST. NEWLY FORMED TS HERMINE
FCST TO MAKE LANDFALL SOMEWHERE ALONG THE S TX/N MEXICO COASTLINE
IN AROUND 24 HOURS THEN TREK NWD THRU W TX. MAIN IMPACT FOR SE TX
WILL BE RAINFALL AND TIDE/MARINE ISSUES. LATE MON NIGHT AND TUES
LOOKING TO BE A WASHOUT WITH DEEP TROPICAL MOISTURE FLOWING IN ON
THE ERN SIDE OF THE TS. DECIDED TO ISSUE A FF WATCH GENERALLY WEST
OF A FREEPORT TO COLUMBUS LINE FOR TONIGHT AS A DISTINCT AREA OF
SFC CONVERGENCE SETS UP IN THE REGION BETWEEN I-10 AND THE COAST
WHICH COULD SERVE AS A FOCUS FOR INTENSE RAINFALL. SUSPECT THIS
AREA MIGHT NEED TO BE EXTENDED NORTH AND EAST ON TUES...MAYBE TO A
COLLEGE STATION TO LIBERTY LINE BUT WILL LET THE DAYSHIFT MAKE
THAT CALL AS MORE DATA BECOMES AVAILABLE. WILL MENTION LOCALLY HEAVY
RAINFALL FOR NOW.

STILL HAVE PLENTY OF GULF MOISTURE STREAMING INTO SE TX THRU THURS
SO ANTICIPATE HIGHER END SCT PRECIP TO PERSIST EACH DAY. AREAL
COVERAGE SHOULD GRADUALLY DIMINISH GOING INTO THE WEEKEND AS PW`S
DROP A BIT AND UPPER RIDGE GRADUALLY FILLS BACK IN FROM THE EAST. 47

[srainhoutx]

FLOOD WATCH
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
448 AM CDT MON SEP 6 2010

TXZ210-211-226-227-235>237-070100-
/O.NEW.KHGX.FF.A.0005.100907T0000Z-100908T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
AUSTIN-BRAZORIA-COLORADO-FORT BEND-JACKSON-MATAGORDA-WHARTON-
INCLUDING THE CITIES OF...ALVIN...ANGLETON...BAY CITY...
BELLVILLE...COLUMBUS...EAGLE LAKE...EDNA...EL CAMPO...FREEPORT...
LAKE JACKSON...MISSOURI CITY...PALACIOS...PEARLAND...PIERCE...
RICHMOND...ROSENBERG...SEALY...SUGAR LAND...WEIMAR...WHARTON
448 AM CDT MON SEP 6 2010

...FLASH FLOOD WATCH IN EFFECT FROM THIS EVENING THROUGH TUESDAY
EVENING...

THE NATIONAL WEATHER SERVICE IN HOUSTON/GALVESTON HAS ISSUED A

* FLASH FLOOD WATCH FOR A PORTION OF SOUTHEAST TEXAS...INCLUDING
THE FOLLOWING COUNTIES...AUSTIN...BRAZORIA...COLORADO...FORT
BEND...JACKSON...MATAGORDA AND WHARTON.

* FROM THIS EVENING THROUGH TUESDAY EVENING

* TROPICAL STORM HERMINE IS FORECAST TO MOVE INLAND ALONG THE
COASTLINE OF SOUTH TEXAS OR NORTHERN MEXICO LATE TONIGHT AND
TRACK NORTH NORTHWEST INTO THE RIO GRANDE VALLEY TUESDAY...THEN
INTO WEST TEXAS ON WEDNESDAY. RAIN CHANCES WILL INCREASE THROUGH
THE DAY TODAY AND EXPECT PRECIPITATION TO BECOME WIDESPREAD
OVERNIGHT AND TUESDAY. LOCALLY HEAVY RAIN AND TRAINING CELLS ARE
LIKELY. EXPECT WIDESPREAD 1 TO 3 INCH RAINFALL AMOUNTS THROUGH
TUESDAY WITH THE POTENTIAL FOR SIGNIFICANTLY HIGHER AMOUNTS
WHERE TRAINING PRECIPITATION OCCURS. SOME FORECAST MODELS ARE
DEPICTING A DISTINCT SURFACE BOUNDARY DEVELOPING BETWEEN THE
COAST AND INTERSTATE 10 LATER TONIGHT. SHOULD THIS BOUNDARY
ACTUALLY DEVELOP...IT COULD BECOME A FOCUSING MECHANISM FOR
INTENSE RAINFALL LEADING TO MUCH HIGHER RAINFALL TOTALS. WE WILL
CONTINUE TO MONITOR THIS SITUATION.

[srainhoutx]

FLOOD WATCH
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
209 PM CDT MON SEP 6 2010

TXZ212-213-238-071100-
/O.EXA.KHGX.FF.A.0005.100907T0000Z-100908T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GALVESTON-HARRIS-WALLER-
INCLUDING THE CITIES OF...BROOKSHIRE...FRIENDSWOOD...GALVESTON...
HEMPSTEAD...HOUSTON...HUMBLE...KATY...LEAGUE CITY...PASADENA...
PRAIRIE VIEW...TEXAS CITY...TOMBALL
209 PM CDT MON SEP 6 2010

...FLASH FLOOD WATCH IN EFFECT FROM 7 PM CDT THIS EVENING THROUGH
TUESDAY EVENING...

THE NATIONAL WEATHER SERVICE IN HOUSTON/GALVESTON HAS EXPANDED
THE

* FLASH FLOOD WATCH TO INCLUDE A PORTION OF SOUTHEAST TEXAS...
INCLUDING THE FOLLOWING COUNTIES...GALVESTON...HARRIS AND
WALLER.

* FROM 7 PM CDT THIS EVENING THROUGH TUESDAY EVENING

* TROPICAL STORM HERMINE IS FORECAST TO MOVE INLAND ALONG THE
COASTLINE OF EXTREME NORTHERN MEXICO THIS EVENING AND TRACK
NORTH NORTHWEST INTO THE RIO GRANDE VALLEY LATE TONIGHT AND
TUESDAY...THEN INTO WEST CENTRAL TEXAS EARLY WEDNESDAY.
PRECIPITATION IS EXPECTED TO BECOME WIDESPREAD OVERNIGHT AND
CONTINUE THROUGH TUESDAY ACROSS SOUTHEAST TEXAS. LOCALLY HEAVY
RAIN AND TRAINING CELLS ARE LIKELY. EXPECT WIDESPREAD 1 TO 3
INCH RAINFALL AMOUNTS THROUGH TUESDAY WITH THE POTENTIAL FOR
SOME AREAS TO EXPERIENCE 4 TO 8 INCHES WHERE TRAINING
PRECIPITATION OCCURS.

[srainhoutx]

COASTAL HAZARD MESSAGE
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
142 PM CDT MON SEP 6 2010

...COASTAL FLOOD WARNING FOR THE UPPER TEXAS COAST TODAY THROUGH
TUESDAY...

...RIP CURRENTS AND ELEVATED TIDES WILL BE AN ISSUE ON THE GULF
FACING BEACHES TODAY AND TUESDAY...

.TROPICAL STORM HERMINE IN THE WESTERN GULF OF MEXICO IS EXPECTED
TO MAKE LANDFALL OVER NORTHERN MEXICO OR DEEP SOUTH TEXAS LATE
TONIGHT AND EARLY TUESDAY MORNING. SWELLS AND STRONG WINDS
ASSOCIATED WITH THE SYSTEM WILL RESULT IN ELEVATED TIDES ALONG
THE UPPER TEXAS COAST TODAY THROUGH TUESDAY.

TXZ214-236>238-070245-
/O.UPG.KHGX.CF.A.0004.000000T0000Z-100908T0000Z/
/O.NEW.KHGX.CF.W.0004.100906T1842Z-100908T0000Z/
BRAZORIA-CHAMBERS-GALVESTON-MATAGORDA-
142 PM CDT MON SEP 6 2010

...COASTAL FLOOD WARNING IN EFFECT UNTIL 7 PM CDT TUESDAY...

THE NATIONAL WEATHER SERVICE IN HOUSTON/GALVESTON HAS ISSUED A
COASTAL FLOOD WARNING...WHICH IS IN EFFECT UNTIL 7 PM CDT
TUESDAY. THE COASTAL FLOOD WATCH IS NO LONGER IN EFFECT.

TIDE LEVELS ARE EXPECTED TO PEAK BETWEEN 2 TO 2.5 FEET ABOVE
NORMAL. ACTUAL TIDE LEVELS ARE EXPECTED TO PEAK AT 4 TO
4.6 FEET ALONG THE GULF FACING BEACHES...AND 3.2 TO 3.7 FEET
ALONG THE SHORES OF GALVESTON AND MATAGORDA BAYS AT THE TIME OF
HIGH TIDE BOTH TODAY AND TUESDAY. RAIN BANDS PUSHING INLAND MAY
SUPPORT HIGHER WIND GUSTS WHICH COULD BRIEFING DRIVE TIDE LEVELS
HIGHER THAN PREDICTED LEVELS.

IN BRAZORIA AND GALVESTON COUNTIES...MINOR FLOODING IS POSSIBLE
ALONG THE BOLIVAR PENINSULA...WESTERN GALVESTON ISLAND...AND
SURFSIDE. MINOR FLOODING IS POSSIBLE ALONG HIGHWAY 87 ON THE
BOLIVAR PENINSULA...COUNTY ROAD 257...THE BLUE WATER HIGHWAY...
AND ON FM HIGHWAY 3005 ON THE WEST END OF GALVESTON ISLAND. THE
TIDAL FLOODING ON TOP OF WAVE ACTION COULD RESULT IN WATER
PUSHING UP ABOVE THE SAND DUNES.

IN MATAGORDA COUNTY...MINOR FLOODING WILL BE POSSIBLE ON FM
HIGHWAY 457 SOUTH OF SARGENT AND FM HIGHWAY 2031 SOUTH OF
MATAGORDA GOING TO MATAGORDA ISLAND.

IN ADDITION TO HIGH WATER LEVELS...HIGH SURF WILL CREATE STRONG
RIP CURRENTS SO SWIMMING IS DISCOURAGED.

PERSONS SHOULD CONTINUE TO MONITOR THE LATEST FORECASTS ON
TROPICAL STORM HERMINE. ANY NORTHWARD DEVIATION IN THE FORECAST
TRACK OF THE SYSTEM COULD RESULT IN HIGHER TIDE LEVELS THAN WHAT
IS CURRENTLY FORECAST.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A COASTAL FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR
IMMINENT. COASTAL RESIDENTS IN THE WARNED AREA SHOULD BE ALERT
FOR RISING WATER...AND TAKE APPROPRIATE ACTION TO PROTECT LIFE
AND PROPERTY.

&&

NOTE...THE FOLLOWING HIGH TIDE LEVELS ARE REFERENCED FROM MEAN
LOWER LOW WATER.

LOCATION HIGH TIDES EXPECTED
TIMES WATER LEVEL

MORGANS POINT...


TUE 10:09 AM 3.4 FEET
TUE 7:10 PM 3.4 FEET

WED 9:53 AM 2.8 FEET
WED 8:59 PM 2.9 FEET

MANCHESTER...

MON 7:06 PM 3.5 FEET

TUE 10:15 AM 3.4 FEET
TUE 8:31 PM 3.6 FEET

WED 10:21 AM 2.8 FEET
WED 9:50 PM 3.2 FEET

ROLLOVER PASS...

MON 5:02 PM 2.7 FEET

TUE 8:09 AM 3.2 FEET
TUE 6:30 PM 3.3 FEET

WED 7:58 AM 2.6 FEET
WED 7:51 PM 2.8 FEET

EAGLE POINT...


TUE 9:11 AM 3.5 FEET
TUE 5:19 PM 3.3 FEET

WED 8:29 AM 2.7 FEET
WED 7:39 PM 2.7 FEET

GALVESTON CHANNEL (PIER 21)...

MON 1:53 PM 3.3 FEET

TUE 4:46 AM 3.5 FEET
TUE 3:20 PM 3.7 FEET

WED 5:02 AM 3.0 FEET
WED 4:42 PM 3.2 FEET

GALVESTON PLEASURE PIER...



TUE 3:46 AM 4.6 FEET
TUE 2:46 PM 4.4 FEET

WED 4:12 AM 4.0 FEET
WED 3:59 PM 4.1 FEET

FREEPORT USCG...



TUE 4:00 AM 4.1 FEET
TUE 2:29 PM 4.0 FEET

WED 4:14 AM 3.4 FEET
WED 3:46 PM 3.6 FEET

PORT OCONNOR...


TUE 2:11 PM 3.2 FEET

WED 8:16 AM 2.6 FEET
WED 5:28 PM 2.7 FEET

$$

[srainhoutx]

Just picked up another 1.7 inches bringing the unofficial total in my backyard to near 4 inches since this morning.

[srainhoutx]

Latest thinking from HGX concerning rainfall/flood issues and the possibilities of some tornadic activity...very near 4 inches of rain already in NW parts of Harris County...


FXUS64 KHGX 062021
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
321 PM CDT MON SEP 6 2010

.DISCUSSION...
TS HERMINE IS APPROACHING THE EXT N MEX COASTLINE THIS AFTERNOON
AND WILL MAKE LANDFALL LATER THIS EVENING. HERE LOCALLY WE ARE
SEEING QUITE A BIT OF SHWR/TSTM ACTIVITY MOVING NW OFF OF THE
GULF AS THE NORTHERN FRINGE OF DEEP TROPICAL MOISTURE ADVECTS INTO
AND ACROSS SE TX. PW VALUES ARE EXPECTED TO CONTINUE TO RISE
TONIGHT WITH VALUES IN THE 2.2 TO 2.6 RANGE AREAWIDE LATE TONIGHT
AND TOMORROW. THIS WILL SET THE STAGE FOR PERIODIC SHWR/TSTM
DEVELOPMENT ACROSS THE AREA THROUGH TUESDAY. ALTHOUGH STORM
MOVEMENT WILL BE AROUND 30 MPH...WE EXPECT TO SEE SOME TRAINING OF
CELLS ACROSS PORTIONS OF THE AREA...PARTICULARLY THE SW HALF OF SE
TX. IT IS FOR THIS REASON WE HAVE A FLOOD WATCH IN EFFECT
GENERALLY SW OF A GALVESTON TO HOUSTON TO BELLVILLE LINE. IN A FEW
SMALL AREAS THERE WILL BE THE POSSIBILITY FOR RAINFALL AMOUNTS TO
EXCEED 4 INCHES THROUGH TUESDAY IN THE WATCH AREA.

THERE IS A SMALL CHANCE OF SEEING ISOLATED TORNADOES TONIGHT AND
TOMORROW AS RAINBANDS COME ONSHORE ACROSS COASTAL SW AREAS. THIS
THREAT IS GENERALLY SW OF A FREEPORT TO WHARTON TO COLUMBUS LINE.

THERE WILL BE PLENTY OF DEEP MOISTURE STILL IN PLACE ON WED...SO
KEPT HIGH CHC POPS IN THE FORECAST THRU AROUND MID-WEEK THEN
BRING THEM DOWN FRI AND NEXT WEEKEND AS THE AREA BECOMES UNDER THE
INFLUENCE OF A BROAD E-W ORIENTED MID-UPPER RIDGE. THIS WILL
RESULT IN ONLY A SLIGHT CHC OF RAIN AND ABOVE NORMAL TEMPERATURES.
33

[srainhoutx]

MESOSCALE DISCUSSION 1791
NWS STORM PREDICTION CENTER NORMAN OK
0501 PM CDT MON SEP 06 2010

AREAS AFFECTED...PORTIONS LOWER-MIDDLE TX COASTAL PLAIN

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 062201Z - 062300Z

THREAT FOR TORNADOES PRODUCED BY TS HERMINE IS MRGL NOW BUT FCST TO
INCREASE GRADUALLY FROM S-N ACROSS THIS AREA THROUGH REMAINDER
AFTERNOON AND INTO EVENING.

TIME SERIES OF LOW-LEVEL VWP HODOGRAPHS AT BRO SHOW STEADY TENDENCY
FOR ENLARGEMENT...WITH 0-1 KM SRH NOW IN 100-200 J/KG RANGE
DEPENDING ON INPUT CELL MOTION USED. THIS TENDENCY SHOULD CONTINUE
FOR A FEW MORE HOURS UNTIL CENTER GETS CLOSER TO ANY GIVEN
POINT...WHEREUPON INCREASING TREND IN BOUNDARY LAYER SHEAR VECTOR
SHOULD BEGIN TO LEVEL OFF. MEANWHILE SIMILAR TREND IN HODOGRAPHS
SHOULD OCCUR FARTHER N TOWARD TX COASTAL BEND...BUT DELAYED BY
SEVERAL HOURS IN STEP WITH RELATIVE PROXIMITY TO HERMINE. MOST
FAVORABLE JUXTAPOSITION OF BUOYANCY AND SHEAR SHOULD OCCUR OVER
MIDDLE-OUTER SECTOR FROM NNW-SE OF CENTER. MLCAPE CURRENTLY IN
1000-1500 J/KG RANGE AWAY FROM THICK CLOUDS/HEAVY PRECIP WILL
DIMINISH SOMEWHAT WITH LOSS OF SFC DIABATIC HEATING INLAND...HOWEVER
WEAK CINH AND VERY RICH LOW-LEVEL THETAE SHOULD KEEP EFFECTIVE
INFLOW PARCELS SFC-BASED EXCEPT IN CLOSE PROXIMITY TO LARGE PRECIP
CORES. MAIN LIMITING FACTOR WILL BE SMALL AREA COVERED BY BEST
OVERLAP OF SHEAR AND AT LEAST MRGL INSTABILITY. GIVEN NHC FCST
TRACK OF CENTER AND STRENGTH/RADII OF WIND FIELDS...FAVORABLE NNW-SE
SECTOR WILL SPREAD NNWWD/INLAND WITH SOME EXPANSION ALSO POSSIBLE IN
EVENT OF ANY INTENSIFICATION. RADAR SRM TRENDS ALREADY INDICATE
BRIEF/SPORADIC AND MAINLY WEAK SHEAR COUPLETS WITH CELLS OFFSHORE
AND OVER MEX...BUT WITHOUT SUSTAINED/WELL-ORGANIZED SUPERCELL
STRUCTURES UP TO THIS POINT. STG-SVR TSTM GUSTS ALSO ARE POSSIBLE
FROM MOST INTENSE OUTER CELLS AND BANDS...OUTSIDE RADIUS OF DAMAGING
AMBIENT/GRADIENT WINDS.

REF NHC ADVISORIES FOR LATEST TRACK/INTENSITY FCST GUIDANCE ON TS
HERMINE.

..EDWARDS.. 09/06/2010


ATTN...WFO...HGX...CRP...EWX...BRO...