Remnants of Tropical Storm Odile

[LocoAko]

Just figured I'd get a main thread going for the potential impacts of the remnants of Tropical Storm Odile on the Southern Plains to organize the discussion. So far, the Euro has backed off of its prolific rainfall totals (up to 17" SW of OKC) that it showed yesterday, but forecasts keep bouncing around a bit as is to be expected, with the GFS now shifting the swath of heaviest rain into northern OK from southern KS and the 84-hr NAM doing the same.

 

 

WPC Discussion

 

 

 

DAY 1

SOUTHWEST INTO THE SOUTHERN PLAINS

WIDESPREAD HEAVY TO EXCESSIVE RAINFALL LIKELY DAY 1 ASSOCIATED
WITH THE CIRCULATION OF ODILE AND WELL TO THE EAST OF THIS
CIRCULATION IN THE MUCH ABOVE AVERAGE PW AXIS THAT WILL STRETCH
FROM SOUTHERN CA/SOUTHERN NV---EASTWARD INTO AZ---NM AND INTO THE
SOUTHERN PLAINS. OBSERVED PW VALUES ACROSS THESE AREAS ARE NEAR
OR ABOVE THE 99 PERCENTILE FOR SEPTEMBER---WITH NO SIGNIFICANT
CHANGES EXPECTED DURING THIS PERIOD TO THESE VALUES. THERE IS A
STRONG MODEL SIGNAL FOR HEAVY TO EXCESSIVE RAINFALL AMOUNTS ACROSS
SOUTHEASTERN AZ---SOUTHERN NM---LEADING TO HIGH CONFIDENCE ACROSS
THESE AREAS. FARTHER TO THE EAST FROM THESE AREAS--THERE IS MORE
MODEL SPREAD WITH HOW QUICKLY HEAVY PRECIPITATION BREAKS OUT INTO
THE SOUTHERN PLAINS. THE HI RES MODELS ARE MORE EMPHATIC ACROSS
THIS AREA---BUT STILL HAVE SOME SIGNIFICANT NORTH-SOUTH
DIFFERENCES WITH THEIR RESPECTIVE AXES. CONFIDENCE IS LOWER
HERE--BUT WITH THE ABOVE MENTIONED HIGH PW AXIS AND MODEL
FORECASTS OF UPPER DIFFLUENCE MAXIMUM IN THIS HIGH PW AXIS---FAVOR
THE HI RES IDEA OF SPREADING HEAVY TO LOCALLY EXCESSIVE RAINFALL
AMOUNTS EASTWARD QUICKER. WHILE MODELS DO NOT DEPICT MUCH
PRECIPITATION ON THE NORTHWESTERN PORTION OF THE ANOMALOUS PW AXIS
FROM SOUTHERN CA INTO SOUTHERN NV AND NW AZ---SCATTERED CONVECTION
LIKELY AGAIN ACROSS THESE AREAS--WITH LOCALLY HEAVY TO EXCESSIVE
RAINFALL AMOUNTS POSSIBLE.

 

 

 

 

 

Threw this together from the GFS forecast PWAT and the climatological PWAT graph from OUN to demonstrate their point:

 

 

Forecast Offices Graphics

 

Norman

 

 

Amarillo

 

 

 

 

Drought Monitor

 

 

And just for fun, a discussion from the Oklahoma State Climatologist of the heaviest rainfall events in Oklahoma history (all due to tropical remnants):

 

http://ticker.mesonet.org/select.php?mo=09&da=16&yr=2014

This post has been promoted to an article

[Srain]

EPZ reports Flash Flooding 1 mile WSW of Rock Hound State Park in Luna County, NM. One car washed away with water recue completed. No injuries reported.

 

[DoctorMu]

Flooding may be imminent in HOU area.  This event with Odile moisture pouring in and ex 92L wave onshore with persistent influx of Gulf moistures... could be prolonged through Thursday.

 

 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1107 AM CDT WED SEP 17 2014

.UPDATE...
AFTER MORNING COLLABORATION WITH WPC...THERE HAS BEEN AN ONGOING
ADJUSTMENT OF OUR POPS/WX/QPF GRIDS. THE MAIN THEME IS FOR THE
THREAT OF MORE AREA-WIDE HEAVY RAINFALL LEADING TO FLOODING. THE
CLUSTERS THAT HAVE PASSED ACROSS NORTH-NORTHWEST HARRIS COUNTY HAVE
DROPPED LARGE AMOUNTS OF RAIN IN A SHORT AMOUNT OF TIME...WITH AN
EXAMPLE OF AN INCH WITHIN 15 MINUTES AT THE CYPRESS CREEK AT FM
249 HCFCD RAIN GAUGE. CLUSTERS OF SLOW-MOVING SHOWERS AND STORMS
FORMING WITHIN A HIGHLY MOIST TROPICAL-IN-NATURE AIR MASS HAVE THE
POTENTIAL OF PUTTING DOWN HIGH RAINFALL AMOUNTS/RATES OVER THE
NEXT 24 TO 36 HOURS. FFG HAS HOURLY RATES OF TWO TO THREE INCHES
LEADING TO FLOODING CONCERNS...THREE TO FOUR INCH AMOUNTS OVER 3
TO 6 HOURS WILL SIGNIFICANTLY HEIGHTEN THE FLOOD THREAT...AS WELL.
IN GENERAL...RECENT HIGH RAINFALL RATES/HIGHER RELATIVE-VOLUMETRIC
SOIL CONTENT VALUES RESIDE OVER THOSE COUNTIES EAST AND SOUTHWEST
OF THE CITY SO...ALONG WITH HOUSTON METRO/SUBURBS...THESE WILL BE
THE AREAS THAT WILL MOST LIKELY EXPERIENCE FLOODING ISSUES. POINTS
SURROUNDING THESE LOCATIONS CAN HANDLE MORE RAINFALL...BUT WITH
THESE RECENTLY HIGH HOURLY RAINFALL RATES OF BETWEEN A HALF OF AN
INCH TO NEAR NEAR TWO INCHES...ANY COMMUNITY COULD BE IN THE HAT
IN DEALING WITH (FLASH) FLOODING. THE REST OF THE FORECAST WILL
REMAIN UNCHANGED...OVERCAST WITH AFTERNOON TEMPERATURE EXTREMA IN
THE MID TO UPPER 80S WITH MORNING READINGS FALLING INTO THE MIDDLE
70S. 31

[Srain]

From Nesdis:

 

SATELLITE PRECIPITATION ESTIMATES..DATE/TIME 09/17/14 1649Z
SATELLITE ANALYSIS BRANCH/NESDIS---NPPU---TEL.301-683-1404
LATEST DATA USED: GOES-15 1600Z  RUMINSKI
.
LOCATION...TEXAS...NEW MEXICO...ARIZONA...
.
ATTN WFOS...LUB...AMA...MAF...ABQ...EPZ...TWC...FGZ...PSR...
ATTN RFCS...ABRFC...WGRFC...CBRFC...
.
EVENT...UPDATE TO PREVIOUS MESSAGE FOR HEAVY RAIN FROM ODILE
.
SATELLITE ANALYSIS AND TRENDS...NUMEROUS FEATURES ASCD WITH THIS
BROAD SYSTEM TO SUPPORT HEAVY RAIN. LATEST IMAGERY SHOWS REMAINING
CORE CNVTN ASCD W/ODILE IS NEAR 30N111W AND HAS BN TRACKING ENE PAST
FEW HRS. CLD TOP TEMPS HAVE BN SLOWLY WARMING AND THIS SUGGESTS LOWER
RAIN RATES. MOST RECENT QMORPH PRODUCT (COMBINES MICROWAVE DERIVED RAIN
RATES WITH SUBSEQUENT GOES IR IMAGERY) SHOWS A CONTD DOWNWARD TREND FROM
OVERNIGHT. 6 HR ESTIMATES THRU 12Z SHOW MAX OF 1.5" TO 2"..ALTHO THIS DOES
NOT ACCOUNT FOR OROGRAPHICS. BINOVC FROM NRN CHIHUAHUA INTO SRN NM THEN
WRAPPING INTO SE AZ WILL ALLOW FOR SOME SOLAR HEATING/DESTABILITZATION
THIS AFTN ARND PERIPHERY OF CORE. SOME SEMBLANCE OF OUTER BAND IS N/S
ORIENTED RUNNING THRU FAR W TX INTO CENTRAL NM  WHERE IT FEEDS INTO
LARGER CLOUD/PRECIP MASS ASCD WITH WELL DEFINED VORT LOBE.
.
SHORT TERM OUTLOOK VALID 1630-2230Z...MEDIUM TO HIGH CONFIDENCE FACTOR
IN SHORT TERM OUTLOOK...CENTRAL CORE EXPECTED TO TRACK ACRS FAR SE AZ
(ERN PIMA..SANTA CRUZ..COCHISE) INTO SW NM (HIDALGO) THIS PD WITH 1-2"
GENERAL AMNTS AND LOCALIZED AMNTS UP TO 3" MAINLY IN OROGRAPHICALLY
FAVORED LOCATIONS (S AND SE FACING SLOPES). ANY CNVTN THAT DEVELOPS
IN BINOVC E AND N OF CENTRAL CORE HAS POTENTIAL FOR SOMEWHAT HIGHER
RAIN RATES BUT LESS DURATION. ORGANIZED AREA ASCD WITH VORT IN CENTRAL
NM EXPECT TO GRADUALLY SHIFT EWRD WITH SWATH OF HEAVY RAIN INTO SW TX
PANHANDLE..MAINLY ARND 1" WITH SPOTTY 2" AMNTS PSBL.

 

 

[aslkahuna]

So far the heaviest valley rain in AZ is in SW Cochise and SE Santa Cruz Counties around the Fort Huachuca area with rain fall amounts around 1 in. Would expect the heaviest mountain rains will be in the Santa Ritas, Huachuca, Chiricahua, Pinalenos and Santa Catalina mountains.

Steve

[LocoAko]

Still some pretty different solutions on the 12Z models. At a quick glance, the GFS brings the corridor of heavy rain in a strip from Santa Fe, NM --> Dalhart, TX --> Liberal, KS and eastward along the OK/KS border from there. This represents a further south solution than last night's runs (which had the bulk of the QPF in SE KS) but a slight shift north from the 06Z run. Heavy rains also fall in the Lubbock--Abilene corridor.

 

 

The 12Z Euro still has a much slower system with the bulk of the rain occurring in the Texas Panhandle, where everywhere from Amarillo to Midland receives 3"+ of rain and there is a wide area of 6-8" totals around Lubbock. Most of Oklahoma receives 1-3", with rains lasting into the middle of next week. 

[Srain]

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
230 PM EDT WED SEP 17 2014


PRELIM DAY 1 QPF DISCUSSION
VALID SEP 18/0000 UTC THRU SEP 19/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1
~~~~~

SOUTHWEST INTO THE SOUTHERN PLAINS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
WIDESPREAD HEAVY TO EXCESSIVE RAINFALL IS LIKELY THIS PERIOD,
ASSOCIATED WITH THE CIRCULATION OF ODILE AND POSSIBLY A SMALL
VORTICITY MAXIMUM ON ITS EASTERN SIDE WHICH APPEARS TO BE LINKED
TO THE REMAINS OF TROPICAL DEPRESSION 16-E.  A MUCH ABOVE AVERAGE
PRECIPITABLE WATER (PW) AXIS WILL STRETCH FROM SOUTHERN
CA/SOUTHERN NV---EASTWARD INTO AZ---NM AND THROUGH TX.  OBSERVED
PW VALUES ACROSS THESE AREAS ARE NEAR THE 99TH PERCENTILE (NEAR
RECORD VALUES) FOR MID-SEPTEMBER AND THE ANOMALOUS MOISTURE SHOULD
REMAIN IN PLACE INTO THURSDAY.  INSTABILITY SHOULD BE LESS OF AN
ISSUE TODAY AS AREAS OF NORTHERNMOST MEXICO, WESTERN TX, AND
SOUTHEAST NM HAVE BEEN SUBJECT TO DAYTIME HEATING, WHICH HAS
INCREASED MIXED LAYER CAPE VALUES TO ROUGHLY 1000 J/KG PER THE
MOST RECENT SPC MESOANALYSIS.

CONSIDERING THE AVAILABLE MOISTURE, HOURLY RAIN RATES UP TO 3" ARE
POSSIBLE ANYWHERE WITH THIS REGION.  THE HOUSTON/GALVESTON TX
FORECAST OFFICE (HGX) REPORTED RAINFALL OF 1.28" IN 30 MINUTES
WITHIN THE INITIAL THUNDERSTORMS THAT FORMED LATE THIS MORNING.
THERE IS A STRONG MODEL SIGNAL FOR HEAVY TO EXCESSIVE RAINFALL
AMOUNTS ACROSS SOUTHEASTERN AZ AND SOUTHERN NM, LEADING TO HIGH
CONFIDENCE ACROSS THESE AREAS.  THE MOST RECENT MESOSCALE GUIDANCE
INDICATES LOCAL AMOUNTS OF 5-8" IN THIS REGION FROM THIS AFTERNOON
INTO THURSDAY.

MODEL SPREAD CONTINUES CONCERNING EXACTLY WHERE HEAVY RAIN
DEVELOPS ACROSS TEXAS.  THE MESOSCALE MODELS ARE QUITE EMPHATIC
ACROSS THIS AREA, WITH LOCAL MAXIMA OF 6-12" NOTED WITHIN THEIR
OUTPUT.  WITH THE ABOVE MENTIONED HIGH PW AXIS AND MODEL FORECASTS
OF UPPER DIFFLUENCE MAXIMUM UNDER AN UPPER-LEVEL HIGH IN THIS HIGH
PW AXIS---FAVOR THE IDEA OF SPREADING HEAVY TO LOCALLY EXCESSIVE
RAINFALL AMOUNTS EASTWARD QUICKER.  WHILE MODELS DO NOT DEPICT
MUCH PRECIPITATION ON THE NORTHWESTERN PORTION OF THE ANOMALOUS PW
AXIS FROM SOUTHERN CA INTO SOUTHERN NV AND NW AZ, SCATTERED
CONVECTION IS LIKELY AGAIN ACROSS THESE AREAS WITH LOCALLY HEAVY
TO EXCESSIVE RAINFALL AMOUNTS POSSIBLE.  THE 12Z WPC QPF
CONTINUITY ACROSS EASTERN NM AND NORTHWEST TX WAS SHIFTED
NORTHWARD PER THE 12Z GUIDANCE AND RECENT RADAR TRENDS AND ADDED
MORE TO THE QPF NEAR LA'S VEGAS AND NORTHWEST AZ TO ACCOUNT FOR
EXPECTATIONS ACROSS THE DESERT SOUTHWEST.



ROTH

 

[Srain]

 

MESOSCALE PRECIPITATION DISCUSSION 0380
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
342 PM EDT WED SEP 17 2014

AREAS AFFECTED...CENTRAL AND SOUTHEAST AZ...SOUTHWEST NM

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 171930Z - 180130Z

SUMMARY...DEEP MOISTURE AND ENERGY ASSOCIATED WITH WEAKENING
TROPICAL DEPRESSION ODILE WILL FOCUS INCREASINGLY HEAVY RAIN
THROUGH THIS EVENING. FLASH FLOODING IS LIKELY.

DISCUSSION...TROPICAL DEPRESSION ODILE IS RAPIDLY WEAKENING OVER
NWRN MEXICO ATTM...HOWEVER THE REMNANT CORE OF CONVECTION AND
HEAVIER RAINFALL IS BEGINNING TO OVERSPREAD SERN AZ. CLOUD TOP
TEMPERATURES HAVE BEEN COOLING ACTUALLY SOMEWHAT OVER THE LAST
COUPLE OF HOURS WITH THE APPROACHING MID LVL VORT
CENTER/CIRCULATION OF ODILE...AND THERE ARE TRENDS FOR HEAVIER
RAINS AND SOME LOCALLY STRONGER CONVECTIVE ELEMENTS ASSOC WITH THE
GRADUAL INCREASE IN DIURNAL HEATING.

RADAR TRENDS INDICATE AN UPTICK IN CONVECTION AHEAD OF THE REMNANT
CNTRL CORE AND ALSO FARTHER NORTH IN AZ JUST SOUTH OF THE MOGOLLON
RIM WHERE OROGRAPHICS APPEAR TO BE AIDING IN LARGER SCALE FORCING
GIVEN THE BROAD CYCLONIC ENVELOPE OF ODILE.

THE 12Z NAM-CONEST APPEARS TOO SLOW WITH THE EVOLUTION OF
ODILE...BUT THE 12Z ARW AND 12Z NMMB HAVE A BETTER REPRESENTATION
OF THE CURRENT PCPN SHIELD AND ORGANIZATION OF ODILE...AND BOTH OF
THESE MODELS DEPICT HEAVY RAINFALL THROUGH THE LATE AFTERNOON AND
EVENING HOURS ACROSS SERN AZ...AND GRADUALLY MOVING BACK INTO SWRN
NM...ESP AFTER 00Z. ADDITIONAL RAINFALL AMOUNTS OF 2 TO 4
INCHES...WITH ISOLD HEAVIER AMTS OVER MOUNTAINOUS TERRAIN ARE
EXPECTED THROUGH THIS EVENING. AREAS OF LESS ORGANIZED BUT INTENSE
CONVECTION ARE ALSO EXPECTED FARTHER NORTH THROUGH THE EVENING
OVER CNTRL AZ AND INCLUDING THE MOGOLLON RIM.

GIVEN WET CONDITIONS LOCALLY FROM EARLIER RAINS...AND WITH
INCREASING RAINFALL RATES/COVERAGE ASSOC WITH ODILE EXPECTED
THROUGH THE EVENING...THE POTENTIAL EXISTS FOR LIFE-THREATENING
FLASH FLOODS AND MUDSLIDES. WILL CONTINUE TO MONITOR.

ORRISON

ATTN...WFO...ABQ...EPZ...FGZ...PSR...TWC...
 

[Srain]

From Nesdis:

 

SATELLITE PRECIPITATION ESTIMATES..DATE/TIME 09/17/14 2020Z
SATELLITE ANALYSIS BRANCH/NESDIS---NPPU---TEL.301-683-1404
LATEST DATA USED: GOES-EAST:2000Z  JS
.
LOCATION...SE TEXAS...
.
ATTN WFOS...LCH...HGX...
ATTN RFCS...WGRFC...
.
EVENT...POSSIBLE GREATER ORGANIZATION SETTING UP WITH CONVECTIVE ACTIVITY
OVER SE TX.
.
SATELLITE ANALYSIS AND TRENDS...SATELLITE VISIBLE AND WATER VAPOR
ANIMATION SHOWS SCATTERED CELLS HAVE FORMED IN FAVORABLE REGION
OF WEAK LOW LEVEL CONVERGENCE AND DECENT UPPER LEVEL DIFFLUENCE.
PROFILES/OBSERVATIONAL DATA ARE INDICATING VERY DEEP MOISTURE WITH SFC
DEWPOINTS RUNNING FROM THE MID TO HIGH 70'S AND PRECIPITABLE WATER VALUES
FROM RECENT MICROWAVE AND GPS DATA NEAR 2.3" WITH SATELLITE IMAGERY ALSO
POINTING TOWARD AN INDIRECT CONNECTION TO THE MID/HIGH LEVEL MOISTURE
FROM ODILE. THIS IS RESULTING IN VERY EFFICIENT RAINFALL PRODUCTION WITH
THE MATURE CELLS LIKELY PRODUCING 2-3"/HR AND EVEN BRIEFLY HIGHER THAN
3"/HR ISOLATED RATES.
.
AN ANNOTATED SATELLITE GRAPHIC SHOWING THE HEAVY PRECIPITATION
THREAT AREA SHOULD BE AVAILABLE ON THE INTERNET ADDRESS LISTED
BELOW IN APPROXIMATELY 10 MINUTES.
.
SHORT TERM OUTLOOK VALID 2015-0215Z...MEDIUM TO HIGH CONFIDENCE FACTOR
IN SHORT TERM OUTLOOK...VISIBLE ANIMATION HAS SHOWN CONVERGENCE IN THE CU
FIELD INTO GROWING AREA OF CONVECTION FROM THE SW AND FROM THE NE. THIS IS
LEADING TO MORE CELL/OUTFLOW MERGERS AND GREATER UPSCALE CONVECTIVE GROWTH
WITH SOME INDICATION OF A POSSIBLE WEDGE SIGNATURE FORMING OVER THE NEXT
HOUR OR 2 NEAR AND NW OF HOUSTON. WITH HIGH ESTIMATED/OBSERVED RAIN RATES
OF 2-3"/HR, CERTAINLY BELIEVE THERE IS SOME THREAT FOR LOCALIZED 2-4"
TOTALS IN A 1-2 HOUR TIME FRAME. THERE IS SOME THREAT FOR THIS ACTIVITY
TO CONTINUE TO SLOWLY BACK BUILD INLAND TO THE NW TOWARD THE GREATER
INSTABILITY AND ALIGN ITSELF PARALLEL TO THE MEAN FLOW. AT THIS TIME,
WITH THE LACK OF FOCUSED INFLOW, BELIEVE THE THREAT FROM THIS PARTICULAR
ROUND WILL REMAIN SOMEWHAT LOCALIZED AND LIKELY LAST FOR ONLY THE NEXT
SEVERAL HOURS THOUGH IT WILL HAVE TO BE WATCHED CAREFULLY GIVEN THE
OVERALL DIFFLUENT PATTERN SEEN IN THE WATER VAPOR ANIMATION AND THE
PRESENCE OF VERY DEEP TROPICAL MOISTURE WITH INDIRECT CONNECTION TO ODILE.
.
 

[aslkahuna]

Heaviest rainfalll will track along with the mid level center which has decoupled to the east of the surface center. Because of the elevations in Santa Cruz and Cochise Counties (about 4500 ft MSL) Gusty winds are and will occur as H7 winds mix down during convective showers. So far FHU has reported 25mph gusts with 32 mph at Canelo.

Steve

[Srain]

Update from Meteorologist Jeff L (Harris County Flood Control District)

 

Flash Flood Watch issued through 700pm Thursday.

 

Ingredients coming together to produce multiple rounds of excessive rainfall this afternoon through Thursday afternoon. Moisture levels have increased to between 150%-200% of normal for this time of year as moisture from the remains of 92L in the Gulf of Mexico and TS Odile over NW MX pour into the region. A favorable trough axis oriented NW to SE across the area has become established while aloft disturbances eject out of Odile and cross MX into and across TX.

 

Rainfall over the past two days has been excessive in isolated spots (upwards of 3 inches per hour) over NW Harris County yesterday and today over SE Harris County and northern Brazoria County. Grounds are gradually saturating and with global and meso scale models show strong support for additional excessive rainfall tonight-Thursday flooding is becoming a more serious threat.

 

Rainfall Amounts:

Hard to be too accurate on the amounts at this point given the scattered nature of the rainfall thus far. Appears more concentrated and organized excessive rainfall is possible on Thursday. Additional average amounts of 1-3 inches will be possible with isolated amounts of 5-7 inches. Air mass is very capable of 3-5 inch per hour rainfall rates which will lead to rapid urban flash flooding and significant rises on area watersheds. I do not see any reason to favor one region over another at this time as there is no well defined surface boundary in place to focus storms along. Storms may end up generating their own surface outflow boundary and focus along that at some point, but when and if that happens is impossible to predict at the moment.

 

Rainfall Last 24 hours:

 

[usedtobe]

I'm not going to talk much about the Southwest since Steve probably is probably familiar with more storms than I am.  Most of the big ones I remember had decent jet streaks associated with them but this one has a pretty good mid level circulation so it might not matter.   Storms coming into the southwest have produced significant rainfall over Texas and Oklahoma.  Both Tico and Norma come to mind but both of those had frontal boundaries and/or jet streaks to help focus convection on the Oklahoma Texas region.  Below I've attached a link that shows the upper level charts for each.  Note the differences in the pattern from what the models are forecasting with this remnant storm.

 

http://www.hpc.ncep.noaa.gov/research/mcs_web_test_test_files/Page1918.htm

 

They had dynamics, this has a vort max that lifts northeastward into western OK and then Kansas.  That doesn't preclude heavy rain but suggests that if there is heavy rain the scale of it would probably be pretty small.  Jake,  posted forecasts of really anomalous moisture forecast across OK but even with such high moisture levels you still need some focus for lifting to keep convection going.   Convection could always focus on outflow from any cells that initiate sort of like a maddox mesohigh event but the scale of the heavy rain on those type events is really small.  Right now that would be my guess, that any heavy rainfall event that forms would have a small scale. 

[Srain]

High Risk for Excessive Rainfall has been issued and embedded upper air disturbances in the NW flow aloft is generating heavy tropical rains across Texas this evening.

[usedtobe]

Steve, the question I have is whether the radar imagery will look similar tomorrow across TX or whether the convection will be more focused. I don't know the answer but worry when there is no surface boundary to speak of.  Maybe the  super saturated airmass will make it a moot point but if I was forecasting, that would be my concern. 

[Srain]

MESOSCALE PRECIPITATION DISCUSSION 0382

NWS WEATHER PREDICTION CENTER COLLEGE PARK MD

930 PM EDT WED SEP 17 2014

AREAS AFFECTED......SOUTHEAST AZ/SOUTHERN NM/EXTREME WEST TX...

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

VALID 180129Z - 180729Z

SUMMARY...DEEP MOISTURE AND ENERGY FROM TROPICAL DEPRESSION ODILE

WILL CONTINUE TO FOCUS THE POTENTIAL FOR HEAVY RAIN THROUGH THE

EARLY MORNING HOURS. FLASH FLOODING IS LIKELY.

DISCUSSION...TROPICAL DEPRESSION ODILE CONTINUES TO WEAKEN...BUT

THE MOISTURE ASSOCIATED WITH IT IS OVERSPREADING SOUTHEAST AZ AND

SOUTHWEST NM. NEW CONVECTION DEVELOPING OVER NORTHEAST

MEXICO...COMPLETE WITH COOLING TOPS...IS EXPECTED TO AFFECT

PORTIONS OF SOUTHEAST AZ/SOUTHERN NM AND THE PANHANDLE OF WEST TX

DURING THE EVENING.

THE BEST INSTABILITY IS EXPECTED TO REMAIN ON THE EAST SIDE OF THE

LOW LEVEL CIRCULATION...AS EVIDENCED BY RADAR TRENDS OVER AND

SOUTH OF SOUTHERN NM. THE CONSENSUS OF THE LATEST HIGH RESOLUTION

MODELS SUGGEST THAT THE MAIN THRUST OF MOISTURE WILL CONTINUE

THROUGH THE EARLY MORNING HOURS. BOTH THE 12Z ARW AND CONEST

SHOWED RAINFALL AMOUNTS BETWEEN 2 AND 4 INCHES...WITH LOCALLY

HIGHER AMOUNTS IN THE HIGHER TERRAIN.

GIVEN THE WET CONDITIONS FROM EARLIER HEAVY RAIN...AND THE DEEP

MOISTURE WITH ODILE MOVING INTO THE REGION...FLASH FLOODING IS

LIKELY. THE POTENTIAL STILL EXISTS FOR LIFE THREATENING FLASH

FLOODS AND MUDSLIDES.

HAYES

[LocoAko]

Thanks for your input, Wes. Greatly appreciated.

[Srain]

The 00Z short term meso guidance are suggesting some worrisome rainfall rates across portions of Central and SE Texas over the next 24 to 48 hours. If they are correct, some locations could see an additional 5 to 10 inches of rain which certainly would lead to Flash Flooding issues.

[1900hurricane]

Similar statements are out for areas to the west, but this one affects me directly so I figured I'd post this one. It'll be interesting to see how convection holds together into the night, as that could really result in totals higher than expected if things last well into the nocturnal hours.

 

 

MESOSCALE PRECIPITATION DISCUSSION 0383
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1037 PM EDT WED SEP 17 2014

AREAS AFFECTED......CENTRAL AND SOUTHEAST TX...

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 180235Z - 180735Z

SUMMARY...A DEVELOPING LOW LEVEL INFLOW WILL FEED HIGH MOISTURE
CONTENT AIR TO CONVECTION ACROSS CENTRAL AND SOUTHEAST TX. AS THE
LOW LEVEL INFLOW OPPOSES A SLOW SOUTHEAST CELL MOVEMENT...FLASH
FLOODING IS POSSIBLE.

DISCUSSION...SCATTERED CONVECTION HAS DEVELOPED ACROSS PORTIONS OF
CENTRAL AND SOUTHEAST TX...AS A DEVELOPING LOW LEVEL FLOW FEEDS
PRECIPITABLE WATER VALUES AS HIGH AS 2.30 INCHES (WHICH IS ABOUT
TWO STANDARD DEVIATIONS ABOVE NORMAL) INTO THE REGION.
THE INCREASING LOW LEVEL FLOW WILL OPPOSE WEAK CORFIDI VECTOR
(WHICH WILL AVERAGE LESS THAN 10 KNOTS)...LEADING TO THE POTENTIAL
FOR SLOW MOVING OR EVEN BACK BUILDING CELLS.

THE HIGH PRECIPITABLE WATER VALUES COULD LEAD TO RAINFALL RATES AS
HIGH AS 2 INCHES AN HOUR (WHICH HAS ALREADY BEEN ESTIMATED BY THE
KHGX RADAR). THE LATEST HIGH RESOLUTION MODEL OUTPUT (INCLUDING
THE 23Z HRRR AND 18Z NAM CONEST) SUGGEST THAT LOCAL 2 TO 4 INCH
RAINFALL AMOUNTS ARE POSSIBLE. THREE HOUR FLASH FLOOD GUIDANCE
VALUES ARE FAIRLY HIGH...BUT THE HIGH RAINFALL RATES AND SLOW CELL
MOVEMENT COULD RESULT IN FLASH FLOODING.

THE HIGHEST CONFIDENCE FOR FLASH FLOODING IS THROUGH ABOUT 05Z.
AFTER THAT TIME...THE INSTABILITY WANES...AND THE SSEO
NEIGHBORHOOD PROBABILITIES DROP OFF SIGNIFICANTLY.

HAYES

ATTN...WFO...CRP...EWX...FWD...HGX...SJT...

ATTN...RFC...WGRFC...

LAT...LON 31609849 31599830 31559812 31489784 31409767
31309746 31269741 31069690 30889646 30799624
30769608 30679594 30459566 30209543 30029535
29849537 29649541 29529544 29239557 29079588
28959621 28929642 28949647 28949705 29119743
29519793 29929841 30449882 30739892 31049903
31259904 31399900 31519881 31579865 

[Srain]

High Water rescues underway in the Austin Area with multiple building fires reported from lightning strikes. Over 4+ inches of heavy rain have fallen in the past 90 minutes across portions of Central Texas.

[Srain]

Updated Excessive Rainfall Outlook will place portions of Central Texas in a Moderate Risk with a Slight Risk continuing for SE Texas and SW Louisiana. The High Risk will remain across Southern New Mexico.

 

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
749 AM EDT THU SEP 18 2014

...VALID 12Z THU SEP 18 2014 - 12Z FRI SEP 19 2014...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...

AZ/NM/CENTRAL TX
~~~~~~~~~~~~~~~~
A LARGE EXCESSIVE RAINFALL AREA REMAINS FROM SOUTHEAST AZ THROUGH
SOUTHERN NM AND A BELT OF CENTRAL TX IN ASSOCIATION WITH THE
REMAINS OF ODILE, WITH A HIGH RISK OF EXCESSIVE RAINFALL
CONTINUING FOR SOUTHERN NM.  THE 1/3/6 HR FLASH FLOOD GUIDANCE
CONTINUES TO LOWER OVER THIS REGION WITH THE CONTINUED WIDESPREAD
RAINFALL.  WHILE THE POTENTIAL FOR AREAS OF LONG DURATION FLOODING
REMAINS A CONCERN...THE HIGHLY ANOMALOUS PW AVAILABILITY (3-3.5
STANDARD DEVIATIONS ABOVE NORMAL) AND WIDESPREAD RAINFALL/HIGH
AREAL-AVERAGE AMOUNTS (1-3.5 INCHES) WILL CONTINUE TO LOWER THE
FFG AND ELEVATE THE FLASH FLOODING RISK.  THE EXPECTATION IS THAT
INSTABILITY SHOULD BUILD ACROSS PORTIONS OF CENTRAL AND WESTERN TX
ALONG WITH ADJACENT PORTIONS OF NORTHERN MEXICO DUE TO DAYTIME
HEATING WITHIN A PARTLY CLOUDY REGION -- RECENT RAP RUNS INDICATE
CAPE VALUES RISE INTO THE 1000-2000 J/KG RANGE ACROSS TX AND
SOUTHEAST NM BY THIS AFTERNOON.  PER COORDINATION WITH THE SJT/SAN
ANGELO TX FORECAST OFFICE, CONSTRICTED THE MODERATE RISK A BIT
ACROSS CENTRAL TX.

EASTERN TX/SOUTHWEST LA
~~~~~~~~~~~~~~~~~~~~~~~
AT PRESENT, THE INSTABILITY LINGERS ACROSS EASTERN TX, WITH
LOW-LEVEL INFLOW SLOWLY FADING.  THE EXPECTATION IS THAT
INSTABILITY SHOULD BUILD ACROSS PORTIONS OF TX ALONG WITH ADJACENT
PORTIONS OF NORTHERN MEXICO DUE TO DAYTIME HEATING WITHIN A PARTLY
CLOUDY REGION -- RECENT RAP RUNS INDICATE CAPE VALUES RISE INTO
THE 1000-2000 J/KG RANGE ACROSS TX AND SOUTHEAST NM BY THIS
AFTERNOON.  PER COORDINATION WITH THE SJT/SAN ANGELO TX FORECAST
OFFICE, CONSTRICTED THE MODERATE RISK A BIT ACROSS CENTRAL TX.
THE MESOSCALE GUIDANCE CONTINUES TO INDICATE LOCALLY HEAVY
RAINFALL SCATTER-SHOT WITHIN A TRIANGLE BOUNDED BY EXTREME
SOUTHWEST LA, THE MIDDLE TX COAST, AND THE EASTERN EDGE OF THE TX
HILL COUNTRY DURING THE DAY TODAY WITHIN AN AREA OF >2"
PRECIPITABLE WATER VALUES AND UPPER-LEVEL DIFFLUENCE.  LOCAL
AMOUNTS OF 4-8" ARE ADVERTISED IN THIS REGION, SO KEPT SOUTHEAST
TX AND EXTREME SOUTHWEST LA WITHIN THE SLIGHT RISK.

 

ROTH/HURLEY

 

[Srain]

Morning Update from Meteorologist Jeff L (Harris County Flood Control District):

 

Several ingredients in place to produce a rather wet day across SE TX.

 

Flash Flood Watch remains in effect until 700pm this evening.

 

Current radar is showing a cluster of slow moving/near stationary heavy rainfall WSW of Austin with a large light rain shield having expanded ESE into SE TX from this cluster. Recently showers have begun to develop from College Station to Houston. These showers appear to being forced by weak lift from a NW to SE laying trough axis along/near US 290 and incoming lift from short waves over NC TX and W TX.

 

Yesterday evening sounding at CRP came in with PW of 2.38 inches which is 200% of mid-September values while LCH was at 2.16. Soundings were saturated from the surface up to about 400mb suggesting little room for evaporation. Freezing level was around 16,000ft yielding a large layer of warm rainfall production. All these ingredients point toward excessive rainfall rates from slow moving and training convection.

 

The main factor that still appears missing is any well defined surface boundary. The weak trough axis laying along US 290 could help to act as a focus for development as well as any left over outflow boundaries. For a significant flood threat I would like to see a well defined boundary to help force and then anchor convection. It is certainly possible to have flooding rainfall without such a boundary, but it tends to be more scattered and not concentrated.

 

Expect a gradual increase in convection this morning as lift increases from the approaching short waves and very modest heating creates even more instability. Nearly the entire area is at risk for development. Storm motions will be slow toward the E or SE which is a favorable setup up for cell training with good SE Gulf inflow. Backbuilding of convection will be toward the WNW or NW.

See no reason at this point to change the expected rainfall amounts from 1-3 inches widespread to isolated amounts of 5-7 inches. Hourly rainfall rates of 2-3 inches are likely which will lead to quick flash flooding of roadways, underpasses, and areas of poor drainage. Current thinking is that most watersheds will be able to handle the rainfall.

 

Drying begins to take place starting Friday, although still expect decent coverage of activity. May be a little harder to dry things out over the weekend as well with moisture from Odile still moving across the area. PWS remain near 2.0 inches and the area will be in a weakness in the sub-tropical ridge so additional scattered storms seem at least possible. Early next week frontal passage is becoming less certain as models have been gradually backing away from the idea of pushing the front through the area.   

 

[Srain]

 

MESOSCALE PRECIPITATION DISCUSSION 0387
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
954 AM EDT THU SEP 18 2014

AREAS AFFECTED...SE NM...W TX

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 181353Z - 181853Z

SUMMARY...A NARROW AXIS OF FOCUSED RAINFALL IS EXPECTED THROUGH
EARLY AFTERNOON. A GENERAL SOAKING RAIN IS EXPECTED...BUT HIGH
RATES IN THE HEAVIER CORES...COMBINED WITH SLOW MOVEMENT...MAY
PRODUCE FLASH FLOODING.

DISCUSSION...ONGOING CONVECTION IN WEST TEXAS HAD THE RADAR
CHARACTER OF A SOAKING...RATHER THAN EXCESSIVE EVENT. THE
ENVIRONMENT MAY BE DECEIVING...HOWEVER... WITH SOME EVIDENCE TO
SUGGEST A FLASH FLOOD THREAT. PRECIPITABLE WATER WAS NEAR 1.7
INCHES AND ABOVE...WHICH IS HIGH FOR ANY TIME OF YEAR IN THIS
REGION. THE FREEZING LEVEL WAS UNUSUALLY HIGH AT AROUND 16000 FT
ABOVE GROUND FOR A LOW LEVEL PARCEL PER THE 12Z MAF RAOB. DUAL POL
DATA FROM LUBBOCK ESTIMATED POCKETS OF 1.5 INCHES IN AN HOUR AND
ISOLATED HIGHER AMOUNTS.

AN MCV APPRAOCHING FROM THE WEST AND A WEAK BUT WELL ESTABLISHED
COLD POOL TO THE NORTH...WILL PUSH NEW CONVECTIVE DEVELOPMENT TO
THE SOUTH AND EAST. CAPE INCREASES IN THIS DIRECTION...AND DEEP
LAYER STEERING WINDS BECOME PARTICULARLY LIGHT THIS
MORNING...WHILE INFLOW AT 850 MB AND ESPECIALLY 700 MB REMAIN
STRONG ENOUGH TO SUPPORT ORGANIZED CONVECTION. THE 10Z AND 11Z
HRRR SHOW A PARTICULARLY STRONG SIGNAL...WITH WIDESPREAD 1 TO 2
INCH RAINFALL AND ISOLATED 4 INCH AMOUNTS THROUGH 19Z.
INTENSIFICATION OF THE PRE-EXISTING MCV...AND/OR DEVELOPMENT OF A
NEW MCV...IS POSSIBLE JUDGING BY MID LEVEL LAPSE RATES IN THE MAF
RAOB...AND THE LIKELIHOOD OF WIDESPREAD LATENT HEAT RELEASE. THIS
COULD FURTHER ORGANIZE THE EVENT ON A SMALL SCALE...MAKING
ISOLATED 4-5 INCH TOTALS POSSIBLE...ESPECIALLY EAST OF LUBBOCK AND
NORTH OF I-20.

BURKE

ATTN...WFO...ABQ...LUB...MAF...OUN...SJT...

 

[usedtobe]

Thanks for your input, Wes. Greatly appreciated.

My concerns look like they were overblown as it a convective system did organize over Austin last night.  This morning's discussion from WPC/Burke that Steve just posted looks like a pretty well thought out one. 

[Srain]

My concerns look like they were overblown as it a convective system did organize over Austin last night.  This morning's discussion from WPC/Burke that Steve just posted looks like a pretty well thought out one. 

Wes, the one concern I have is the advancing outflow boundary across OK to the SW. There is a weak boundary across E Texas that prompted the development we've seen this morning in SE Texas. That complex dropped almost 4 inches in an hour at the house and the short term RAP/HRRR and NAM are suggesting another MCS developing this afternoon across the Hill Country. Time will tell, but the shorter range guidance did pick up on the Austin MCS last night in their 00Z runs. It will be interesting to see how events unfold as the day wears on into this evening.

 

 

[Srain]

 

MESOSCALE PRECIPITATION DISCUSSION 0388
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1114 AM EDT THU SEP 18 2014

AREAS AFFECTED...CENTRAL TX...SE TX...FAR SW LA

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

VALID 181513Z - 182013Z

SUMMARY...LARGE SCALE FORCING WILL OVERSPREAD A REGION
CHARACTERIZED BY UNUSUALLY MOIST AND MODERATELY UNSTABLE AIR. WHEN
COMBINED WITH WET SOILS FROM RECENT RAINS...INSTANCES OF FLASH
FLOODING APPEAR LIKELY THIS MORNING AND THIS AFTERNOON.

DISCUSSION...ONGOING CONVECTION HAD BECOME FAIRLY WIDESPREAD IN SE
TX...AND IS LIKELY TO PERSIST AS A NORTHERN STREAM SHORTWAVE
TROUGH BRUSHES ACROSS THIS REGION...ENHANCING DEEP LAYER ASCENT AS
WELL AS SOUTHWESTERLY INFLOW WINDS AT 850 TO 600 MB. HIGH
RESOLUTION MODELS ARE SIMILAR IN PREDICTING NEW CONVECTION UP INTO
THE TX HILL COUNTRY ALONG A SHARPENING MID LEVEL TROUGH AXIS. AN
UNUSUALLY MOIST ENVIRONMENT AND SUFFICIENT INSTABILITY WILL YIELD
VERY HEAVY RAIN. THE GREATEST CONCENTRATION OF RAIN AND
PERSISTENCE IS EXPECTED OVER SE TX AHEAD OF A DEVELOPING 700 MB
CIRCULATION SEEN IN THE RAP BY 20Z. THOUGH STRENGTHENING WIND
FIELDS MAY CARRY THE EVENT EAST TOWARD SW LOUISIANA...THE WESTERN
FLANK OF LINE SEGMENTS OR THE FLANK OF A SMALL MCS WILL MORE
STRONGLY INTERCEPT INFLOW...PLACING THE GREATEST THREAT OF
EXCESSIVE RAINS AND FLASH FLOODING IN THE VICINITY OF HOUSTON AND
EVENTUALLY POINTS TO THE EAST.

OF PARTICULAR CONCERN...BROAD MESOCYCLONES HAVE ALREADY BEEN
OBSERVED OWING TO VEERING WIND PROFILES AND ABOUT 25 KT OF DEEP
LAYER SHEAR. BOTH THE MEAN 0-6 KM WINDS AND BUNKERS MOTION FOR
RIGHT-MOVING CELLS ARE AROUND 10 KT...BUT THOSE CELLS THAT DEVELOP
MESOCYCLONES WILL TEND TO ANCHOR HEAVY RATES...ON A SPORADIC
BASIS. SUCH ACTIVITY WAS ALREADY OBSERVED WHERE FLASH FLOODING WAS
REPORTED JUST NORTHWEST OF HOUSTON AT 1430Z. WHEREVER CELLS BECOME
ANCHORED 4 INCHES OF RAIN COULD OCCUR IN UNDER 2 HOURS.

BURKE

ATTN...WFO...EWX...FWD...HGX...LCH...SHV...SJT...
 

[1900hurricane]

Looks like a little MCV has developed near Cleveland. That area is really getting slammed.

Sent from my iPhone using Tapatalk

[Srain]

Updated Excessive Rainfall Outlook includes a Moderate Risk across portion of the Hill Country in Texas.

 

[aslkahuna]

Two to five inches of rain in Santa Cruz and Cochise County valley locations fell through the overnight hours. Heavier amounts likely in the mountains and northern Sonora. Flooding along the San Pedro and Santa Cruz rivers with a stage of 18.64 ft in Palominas which is slightly higher than the crest in 2000 when the San Pedro hit 17-20000 cfs flow rate. A number of road closures in Cochise County including Hereford, Moson roads and highway 92 in Palominas which are major roads in the Sierra Vista area. Pioneer Airfield on the west range of Fort Huachuca recorded 3.53 in of rainfall Libby Airfield in the main Post area had 2.34 while Douglas had 2.94in. Cochise and Santa Cruz Counties average 8-10 inches of rain during the monsoon along with copious thunderstorm activity. this year Sierra Vista and Nogales are clossee to and a bit over 15 inches for the monsoon equal to their annual average rainfall. Last year's monsoon was also wet. For the record, since 1970 there have been 5 Tropical Storms in AZ with two of the 5 in Cochise/Santa Cruz Counties wihle there have been 9 significant remnants in the same area since 1986.

Steve

[Chinook]

Here is the KGRK radar Austin area rainfall from the last few days (STP is totalled for four days).  There are some small areas that have had 6" in the last few days. KEWX radar (also totaling for four days) shows some 7-9" amounts west of Austin.

 

 

 

 

 

[LocoAko]

Latest GFS and NAM have all but backed off entirely on significant rain for just about all of Oklahoma -- looks like some of our drought stricken areas will have to keep on waiting.