October 2015 - Severe Storms/Moderate Risk Excessive Rainfal

[houstonia]

If Houston can't get a hurricane from the GOM, we will take one from the Pacific!! LOL

[tireman4]

Be alert and aware folks...this weekend will prove to be challenging to the mets here and at the NWS.....

753
FXUS64 KHGX 221218
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
718 AM CDT THU OCT 22 2015

.AVIATION...
A FEW SPOTTY SHOWERS CONTINUE TO PUSH INLAND THIS MORNING... WITH
ADDITIONAL DEVELOPMENT EXPECTED THROUGH THE MORNING HOURS FROM
HEATING. PREVAILING VCSH FOR THE MAJORITY OF THE DAY DUE TO
UNCERTAINTY WITH TIMING AND WILL HANDLE DEVELOPMENT NEAR THE
TERMINALS WITH TEMPO AMENDMENTS. COULD SEE AN EMBEDDED
THUNDERSTORM OR TWO BUT HOLDING OFF ON MENTION NOW DUE TO
ANTICIPATED LOW COVERAGE. LOW CLOUDS WILL PERSIST FOR MUCH OF THE
DAY... BUT ARE EXPECTED TO LIFT TO HIGH END MVFR THROUGH THE
MORNING HOURS. CIGS AND VISIBILITIES MAY BE LOWER IN HEAVIER
SHOWERS. LOW CIGS ARE EXPECTED TO RETURN AGAIN OVERNIGHT... WITH
IFR TO MVFR RESTRICTIONS FOR MOST TERMINALS AFTER 08Z.

OTHERWISE... ELEVATED EASTERLY TO SOUTHEASTERLY WINDS 10 TO 15
KNOTS EXPECTED TO PERSIST THROUGH THE DAY... WITH STRONGER GUSTS
APPROACHING 20 TO 25 KNOTS POSSIBLE.

HUFFMAN

&&

.PREV DISCUSSION... /ISSUED 435 AM CDT THU OCT 22 2015/

DISCUSSION...
A WIDESPREAD RAIN EVENT IS SHAPING UP FOR THE LATTER HALF OF THE
WEEKEND. EVEN WITH DROUGHT CONDITIONS OVER THE NORTHWESTERN HALF
OF THE FORECAST AREA...A FLASH FLOOD WATCH MAY BE ISSUED FOR
SATURDAY AND SUNDAY LATER THIS WEEK FOR SOME OR ALL OF SE TEXAS.

EARLY THIS MORNING SE TEXAS WAS BETWEEN AN UPPER LOW OVER AZ AND
AN UPPER HIGH PRESSURE AREA CENTERED OVER THE EAST-CENTRAL GULF OF
MEXICO. THE MOST ACTIVE AREAS AT 330 AM INCLUDED A LONG- LIVED MCS
OVER THE WESTERN GULF OF MEXICO AND STORMS ALONG A FRONTAL
BOUNDARY IN THE PANHANDLE. THE WIDESPREAD RAINFALL WILL BE TIED TO
THE ACTIVE SUBTROPICAL JET OVER THE CENTRAL AND WESTERN PARTS OF
THE STATE THAT WILL SLOWLY MOVE EASTWARD AS THE UPPER LOW OVER AZ
SHEARS OUT OVER THE PLAINS.

EVEN THOUGH THE OFFSHORE MCS WILL LIKELY STAY OVER THE GULF...THE
MODELS DO BRING DECENT RAIN CHANCES TO MOST OF SE TEXAS WEST OF
INTERSTATE 45 TODAY AS PW/S REACH TO AROUND 2 INCHES AND SHORTWAVE
TROUGHS IN THE UPPER FLOW MOVE OVERHEAD. PW/S THEN FALL AS SURFACE
RIDGING FROM THE EAST OCCURS...AND A MODEL CONSENSUS SHOWS RAIN
CHANCES DECREASING TONIGHT AND EARLY FRIDAY. DURING THE DAY ON
FRIDAY THE BEST CHANCES WILL BE OVER THE SOUTHWEST AND WEST AS THE
FRONTAL BOUNDARY APPROACHES FROM NORTH TEXAS.

ALTHOUGH THERE IS SOME UNCERTAINTY BETWEEN THE MODELS...A
CONSENSUS HAS THE BEST CHANCES FOR HEAVY RAINFALL BEGINNING
SATURDAY MORNING OVER THE FAR WESTERN COUNTIES OF THE FORECAST
AREA AS A COMBINATION OF EVENTS OCCUR. MOISTURE FROM HURRICANE
PATRICIA IN THE PACIFIC WILL ARRIVE AS LOW PRESSURE FORMS OVER
SOUTH TEXAS AND MOVES NORTHEASTWARD. ALSO...THE UPPER TROUGH LEFT
OVER THE FROM TODAY/S UPPER LOW WILL MOVE ACROSS THE STATE. AN
ABUNDANCE OF MOISTURE IS EXPECTED AS SEEN BY FORECAST PW/S IN
EXCESS OF 2 INCHES APPROACHING THE 99TH PERCENTILE FOR THIS TIME
OF YEAR. AGREE WITH A MODEL CONSENSUS THAT THE HIGHEST CHANCES FOR
HEAVY RAINFALL WILL BE FROM SATURDAY MORNING IN THE WEST...TO AREA
WIDE BY SATURDAY EVENING...AND OVER THE CENTRAL AND COASTAL
COUNTIES SUNDAY MORNING.

THERE ARE SOME DIFFERENCES IN THE MODELS REGARDING MONDAY...WITH
THE GFS MOVING A SURFACE LOW ACROSS THE FORECAST AREA AND THE
ECMWF KEEPING THE LOW OFFSHORE. IF THE GFS SOLUTION PANS OUT...
WIDESPREAD RAINFALL MAY LINGER INTO MONDAY. ACTUALLY LIKE THE
ECMWF SOLUTION BUT WENT WITH A CONSENSUS IN DIMINISHING RAIN
CHANCES MONDAY THROUGH WEDNESDAY.

40

MARINE...
UNSETTLED WEATHER IS EXPECTED TO CONTINUE OVER THE COASTAL WATERS
THROUGH THE UPCOMING WEEKEND. MOISTURE PULLING NORTHWARD FROM A
COMPLEX OF SHOWERS AND THUNDERSTORMS OVER THE CENTRAL GULF EARLY
THIS MORNING WILL RESULT IN PERIODS OF SHOWERS AND THUNDERSTORMS
FOR THE COASTAL WATERS TODAY. HAVE LOW CONFIDENCE ON WHETHER OR
NOT THIS FEATURE WILL MAKE ANY NORTHWARD PROGRESS WITH LITTLE
AGREEMENT AMONGST HIGH RESOLUTION GUIDANCE. ANTICIPATE THE MAIN
THUNDERSTORM COMPLEX TO REMAIN BEYOND 60 NM THROUGH THE DAY... BUT
WILL NEED TO CONTINUE TO MONITOR FOR ANY NORTHWARD DRIFT AS
SEVERAL PLATFORMS OVER THE CENTRAL GULF HAVE REPORTED GALE FORCE
WINDS WITH THESE STORMS.

SOUTHEASTERLY WINDS IN THE 15 TO 25 KNOT RANGE ARE EXPECTED TO
CONTINUE THROUGH THE DAY... WITH THIS PERSISTENT FETCH PROMOTING
WAVES IN THE 6 TO 9 FEET RANGE EARLY THIS MORNING PER BUOY
OBSERVATIONS. HAVE CONTINUED THE SMALL CRAFT ADVISORY THROUGH 00Z
FRIDAY IN RESPONSE...BUT AN ADDITIONAL ADVISORY WILL LIKELY BE
NEEDED FOR THE OFFSHORE WATERS LATER TONIGHT. A BRIEF LULL IN
ELEVATED WINDS AND WAVES WILL BE POSSIBLE ON FRIDAY AS THE SURFACE
PRESSURE GRADIENT RELAXES SOMEWHAT... BUT CONDITIONS ARE EXPECTED
TO DETERIORATE AGAIN THIS WEEKEND AS A COASTAL LOW DEVELOPS OFF
THE LOWER TEXAS COAST. STILL SEEING DISAGREEMENT AMONGST MEDIUM
RANGE GUIDANCE REGARDING THE EVOLUTION OF THIS FEATURE /THE GFS
PULLS THE LOW INLAND TUESDAY... WHILE THE EUROPEAN KEEPS IT OVER
THE NORTHWEST GULF/. THIS DISAGREEMENT LENDS ITSELF TO LOWER
CONFIDENCE FOR THIS PORTION OF THE MARINE FORECAST... BUT EXPECT
INCREASING SHOWER AND THUNDERSTORM CHANCES OVER THE COASTAL WATERS
LATE SATURDAY INTO SUNDAY AS THIS COASTAL LOW MOVES TOWARDS THE
UPPER TEXAS COAST. EXPECT SEAS TO BUILD AGAIN AS WELL IN RESPONSE
TO THIS FEATURE... WITH 8 TO 10 FOOT SEAS POSSIBLE OVER THE
OFFSHORE WATERS SUNDAY INTO MONDAY.

COASTAL FLOODING WILL ALSO REMAIN A PROBLEM TODAY DURING TIMES OF
HIGH TIDE ALONG THE UPPER TEXAS COAST AS ELEVATED ONSHORE WINDS
PROMOTE TIDES ANYWHERE FROM 1.5 TO 2.5 FEET ABOVE NORMAL.
DEPENDING ON THE EVOLUTION OF THE COASTAL LOW OVER THE WEEKEND...
COASTAL FLOODING MAY RESUME AND COASTAL FLOOD ADVISORIES MAY AGAIN
BE NEEDED.

SELECTED TIMES FOR HIGH AND LOW TIDES FOR TODAY AND TOMORROW ARE
LISTED BELOW. FOR MORE INFORMATION... PLEASE SEE THE TIDE FORECAST
PRODUCT.

GALVESTON CHANNEL /PIER 21/
LOW TIDE AT 6:35 AM.
HIGH TIDE AT 10:32 AM.
LOW TIDE AT 6:04 PM.

FREEPORT USCG
LOW TIDE AT 7:48 AM.
HIGH TIDE AT 10:27 AM.
LOW TIDE AT 5:26 PM.

[davidiowx]

If Houston can't get a hurricane from the GOM, we will take one from the Pacific!! LOL

Lolol. I wonder if we will experience TS maybe low end Cat 1 conditions...

[ticka1]

If Houston can't get a hurricane from the GOM, we will take one from the Pacific!! LOL

Named Patricia (wink wink) LOL

[sambucol]

If Houston can't get a hurricane from the GOM, we will take one from the Pacific!! LOL

Named Patricia (wink wink) LOL

Lol !! It fits, Ticka!!!

[srainhoutx]

Getting a bit concerned that the mid level (at 700 /500and 850 mb) vorticity associated with Patricia could move into S Texas between Brownsville and Corpus developing a stronger Coastal low.

The attachment 11222015 12Z GFS f72.gif is no longer available

12Z GFS Total Precipitation through hour 96. Some of those totals in the brighter bands of orange are nearing 12 to 15 inches. The GFS suggest this low will finally move inland near Surfside Monday afternoon.

[stormlover]

I have a bad feeling rain totals might keep increasing i hope though

[srainhoutx]

I have a bad feeling rain totals might keep increasing i hope though

GFS totals through hour 126. Some of these higher ends totals exceed 15 inches.

[tireman4]

Morning AFD from HGX:
32
FXUS64 KHGX 221556
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1056 AM CDT THU OCT 22 2015

.DISCUSSION...
SUNSHINE ACROSS PARTS OF SOUTHEAST TEXAS THIS MORNING HAVE ALLOWED
TEMPERATURES TO ALREADY RISE INTO THE LOWER 80S ACROSS PARTS OF OUR
SOUTHWEST COUNTIES. THE LATEST HIGH RESOLUTION MODELS ARE CURRENTLY
NOT HANDLING THE LARGE MCS OFF THE LOWER TEXAS COAST VERY WELL. SO
FOR NOW...WILL MAKE ONLY VERY MINOR CHANGES TO THE CURRENT FORECAST
THAT HAS LOWER POPS ACROSS OUR EASTERN COUNTIES AND THE HIGHER NUMBERS
ACROSS OUR WESTERN COUNTIES.

WE ARE STILL FOCUSING THE CHANCE FOR HEAVIEST RAINS ACROSS PARTS OF
SOUTHEAST TEXAS OVER THE WEEKEND...POSSIBLY FOCUSING SOME TIME ON
SATURDAY NIGHT AND SUNDAY. 42
&&

[Andrew]

I'm concerned that models are still having trouble properly displaying the amount of moisture that is associated with Patricia. This will be key as water vapor and other satellite imagery shows a system that is both strong and larger than normal. The track also raises an eye. While models currently indicate that the system will remain extra-tropical, a strong coastal low might not be out of the picture. That would only increase the flooding chances.

[Electric Lizard]

With the Formula 1 race taking place this weekend at Austin's Circuit of the Americas, there will be tens of thousands of folks coming from all over the world for a three day, outdoor event in an area with low water crossings that's prone to flash flooding. This could be a real mess.

[srainhoutx]

The GFS suggest we wash, rinse and repeat the same synoptic pattern next weekend.

[ticka1]

Is this the start of our El nino pattern?

[srainhoutx]

Most likely ticka. EWX issues Flash Flood Watch beginning Friday for all of S Central Texas. Likely more to follow from other NWS offices later this afternoon.

[srainhoutx]

MESOSCALE PRECIPITATION DISCUSSION 0598
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1211 PM EDT THU OCT 22 2015

AREAS AFFECTED...WEST TEXAS...NORTH CENTRAL TX

CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY

VALID 221611Z - 222011Z

SUMMARY...EXPECT CONVECTION TO CONTINUE TO TRAIN SOUTHWEST TO
NORTHEAST ALONG A QUASI-STATIONARY SURFACE BOUNDARY...WITH
ADDITIONAL REDEVELOPMENT FORECAST ALONG THE SOUTHERN FLANK OF THE
BOUNDARY. LOCAL RAINFALL RATES OF 1-2 INCHES/HR ARE LIKELY TO
PRODUCE ADDITIONAL FLASH FLOODING ACROSS PORTIONS OF THE REGION.

DISCUSSION...NOT MUCH CHANGE FROM THE PREVIOUS ISSUANCE. A
QUASI-STATIONARY SURFACE BOUNDARY REMAINS IN PLACE FROM THE
WESTERN RED RIVER BACK INTO THE BIG BEND COUNTRY. THE LATEST
MESOANALYSIS SHOWS THAT 30-40 KT SOUTHEASTERLY TO SOUTHERLY FLOW
CONTINUES TO SUPPORT 1.5+ INCH PWS ALONG AND AHEAD OF MUCH OF THE
BOUNDARY WHILE 1000+ J/KG MUCAPE VALUES CONTINUE TO EXTEND
NORTHEAST FROM THE BIG BEND COUNTRY INTO CENTRAL TX. A
SOUTHWEST-NORTHEAST ORIENTED UPPER JET STREAK POSITIONED TO THE
EAST OF AN UPPER LOW CENTERED OVER THE FOUR-CORNERS REGION
CONTINUES TO ENHANCE THE UPPER DIVERGENCE ACROSS THE REGION.
SPLITTING FLOW UPSTREAM IS EXPECTED TO ALLOW THIS LOW TO REMAIN IN
PLACE...WITH NO SIGNIFICANT CHANGE IN THE UPPER LEVEL PATTERN
ANTICIPATED ACROSS THE REGION FOR AT LEAST THE NEXT FEW HOURS.
BELIEVE THE GREATEST POTENTIAL FOR HEAVY RAINFALL RATES REMAINS
COINCIDENT WITH THE GREATER INSTABILITY ALONG THE SOUTHERN FLANK
OF THE BOUNDARY. HOWEVER...CONVECTION TRAINING TO THE NORTH MAY
EXTEND THE FLASH FLOOD THREAT FURTHER TO NORTHEAST ACROSS
NORTH-CENTRAL TX INTO THE RED RIVER REGION.

THE LATEST OUTLOOK AREA WAS AGAIN BASED LARGELY ON AMOUNTS
PRODUCED BY THE 00Z HRW-NMMB -- WHICH OF THE HI-RES
GUIDANCE...APPEARS TO THE HAVE ONE THE BETTER HANDLES ON THE
CURRENT CONDITIONS. THE 00Z HRW-ARW IS TOO PROGRESSIVE...WHILE
EVEN THE MOST RECENT RUNS OF THE HRRR ARE MUCH TOO DRY ACROSS
CENTRAL TX INTO THE BIG BEND COUNTRY.

PEREIRA

ATTN...WFO...FWD...LUB...MAF...OUN...SJT...

[srainhoutx]

From Nesdis:

SATELLITE PRECIPITATION ESTIMATES..DATE/TIME 10/22/15 1719Z
SATELLITE ANALYSIS BRANCH/NESDIS---NPPU---TEL.301-683-1404
LATEST DATA USED: GOES-EAST:1700Z JS
.
LOCATION...S AND SE TEXAS...
.
ATTN WFOS...HGX...CRP...BRO...
ATTN RFCS...WGRFC...
.
EVENT...GENERAL DISCUSSION OF SATELLITE FEATURES/MESO-ANALYSIS WITH
CURRENT SETUP OF MCS VERY CLOSE TO THE S TX COAST AND ITS IMPLICATIONS
INLAND OVER S AND SE TX.
.
SATELLITE ANALYSIS AND TRENDS...AN ANIMATION OF THE PAST 12 HOURS
OF SATELLITE IMAGERY SHOWS CLASSIC MCS DEVELOPMENT OVER THE W GULF OF
MEXICO WITHIN SUBTROPICAL STREAM IN VERY FAVORABLE ENVIRONMENT DIFFLUENT
ALOFT WITH SYSTEM LOCATED BETWEEN RIGHT ENTRANCE REGION OF JET MAX OVER
SE TX/LA/MS AND POSSIBLE MINOR LEFT EXIT REGION ON THE N PERIPHERY OF
OUTFLOW FROM HURRICANE PATRICIA JUST OFF THE S MEXICO COAST. TRENDS HAVE
ALSO SHOWN A CONSISTENT TENDENCY FOR THIS ACTIVITY TO BUILD FARTHER TO
THE W AND CLOSER TO THE S TX COAST. THE MORNING SOUNDING FROM BROWNSVILLE
TX SHOWED AN EXCEPTIONALLY MOIST ENVIRONMENT WITH PW VALUES ALMOST UP
TO 2.4" WHICH APPEARS TO BE A MAX FOR THE DATE AND NOT TOO FAR FROM
THE OCTOBER MAX. RECENT MICROWAVE DATA ALSO SHOWS THE SLUG OF ANOMALOUS
MOISTURE WITH PW VALUES UP TO 2.5" EXTENDING FARTHER OFF THE S TX COAST
INTO THE BAY OF CAMPECHE. TRENDS FROM THE GOES SOUNDER ARE INDICATING
THAT DESPITE THE MCS POTENTIALLY BLOCKING SOME OF THE INFLOW/MOISTURE
TRANSPORT THE MORE SIGNIFICANT MOISTURE IS MAKING ITS WAY FARTHER INLAND
ESPECIALLY OVER FAR S TX. AT THE MID/UPPER LEVELS, PRIMARILY ABOVE 700MB,
ALSO SEEING MOISTURE CONNECTION TIED TO HURRICANE PATRICIA PER ANIMATION
OF THE CIRA LAYERED TPW PRODUCT. AS FOR INSTABILITY, GOES SOUNDER AND
RAP ANALYSIS ARE SHOWING STILL FAIRLY MODEST BUT INCREASING INSTABILITY
OVER S AND SE TX WITH POCKETS OF SB CAPE VALUES OF NEAR 2000J/KG OVER
SE TX AND POSSIBLY NOW UP TO 3000J/KG OVER FAR S TX NEAR THE COAST. AT
THE SFC, NOT SEEING ANY SORT OF BOUNDARY PRESENT THOUGH OBSERVATIONAL
DATA INCLUDING SOME OF THE OFFSHORE PLATFORMS APPEAR TO INDICATE SOME
LOWER LEVEL CONFLUENCE AND SPEED CONVERGENCE NEAR COASTAL SE TX ROUGHLY
BETWEEN PALACIOS AND THE TX-LA COASTAL BORDER WITH SEVERAL OF THE OFFSHORE
PLATFORMS SHOWING 25-30KTS OF SUSTAINED SE INFLOW.
.
OUTLOOK...DO HAVE SOME CONCERN GIVEN THE CONSISTENT SATELLITE TRENDS WITH
THE CONTINUING WESTWARD SHIFT OF THE MCS TOWARD FAR S TX. HOWEVER, AFTER
SPEAKING WITH WPC MPD AND LEAD FORECASTERS, CERTAINLY DO NOT HAVE HIGH
CONFIDENCE IN A SUBSTANTIAL HEAVY RAIN THREAT MATERIALIZING THERE GIVEN
THE LACK OF ANY MODEL SIGNAL INCLUDING THE HI-RES SUITE WPC SURVEYS. IT
IS DEFINITELY A RATHER CLOSE CALL WITH EXTREMELY INTENSE RAINFALL NOT
TOO FAR OFFSHORE AND NEEDS TO BE MONITORED CLOSELY. FARTHER UP THE COAST,
ALSO NOT THAT CONFIDENT IN ANY WIDESPREAD HEAVY RAIN THREAT IN THE SHORTER
TERM DESPITE THE APPARENT LOW LEVEL CONFLUENCE/SPEED CONVERGENCE ALONG
THE SE TX COAST CENTERED ON THE AREA JUST S OF GALVESTON. GIVEN THAT
THE BETTER FORCING IS STILL WELL BACK TO THE W AND THE PRESENCE OF THE
SIGNIFICANT MCS OFFSHORE POTENTIALLY BLOCKING SOME OF THE INFLOW/MOISTURE
TRANSPORT, BELIEVE CONVECTIVE DEVELOPMENT AND SUBSEQUENT HEAVY RAIN
THREAT IN THE SHORTER TERM WOULD REMAIN LOCALIZED AND LIKELY NOT ALL THAT
ORGANIZED. HOWEVER, FOR CONCERNS FARTHER OUT IN TIME WHEN THE LARGER SCALE
LIFT BECOMES MORE ESTABLISHED AND THE LOWER LEVELS MORE FOCUSED, WILL
NEED TO WATCH THE SITUATION VERY CLOSELY GIVEN THE VERY ANOMALOUS MOISTURE
PRESENT WITH CONNECTION ALREADY ESTABLISHED TO HURRICANE PATRICIA.

[Portastorm]

With the Formula 1 race taking place this weekend at Austin's Circuit of the Americas, there will be tens of thousands of folks coming from all over the world for a three day, outdoor event in an area with low water crossings that's prone to flash flooding. This could be a real mess.

F1 will race in rain. If it's very heavy rainfall or lightning, they won't. We probably won't see the latter here in Austin until Saturday morning ... so there could be delays with the qualifying runs. As for persons driving through low water crossings ... most stay in hotels downtown or closer to the track. That probably isn't too much of a concern at this point. Race fans though will get wet from time to time and, in some instances, VERY wet. The Elton John concert Sunday night should be okay. I don't think the GFS verifies by bringing that coastal low inland. But if it does, the concert will also be a wet one!

[Cromagnum]

What are the chances of a strong tropical storm off the SE Texas coast looking like from Patricia after passing through the mountains of Mexico? The intensity forecast at 96 hours indicates that this could easily happen.

[Andrew]

WPC updated QPF

[cperk]

The GFS suggest we wash, rinse and repeat the same synoptic pattern next weekend.

Now that could be a flooding event with the ground saturated from this weekend's rain event.