Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 5

[Srain]

 
MESOSCALE PRECIPITATION DISCUSSION 0277
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
410 PM EDT SUN OCT 13 2013

AREAS AFFECTED...RIO GRANDE VALLEY INTO CENTRAL TEXAS

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

VALID 132010Z - 140210Z

SUMMARY...HEAVY RAIN IS EXPECTED TO CONTINUE JUST NORTH OF AN
OUTFLOW BOUNDARY ACROSS SOUTHWESTERN TEXAS FOR THE NEXT FEW HOURS
ON TOP OF ALREADY SATURATED SOILS...WHICH WILL PROLONG THE FLASH
FLOOD THREAT INTO THE EVENING.

DISCUSSION...19Z SURFACE ANALYSIS SHOWED A WELL DEFINED OUTFLOW
BOUNDARY BETWEEN LRD AND COT...EXTENDING EAST TOWARD MATAGORDA
BAY...WITH LITTLE TO NO MOVEMENT SEEN OVER THE PAST COUPLE OF
HOURS. A CONVECTIVE CLUSTER HAS BEEN ONGOING SINCE THE EARLY
MORNING ACROSS THE REGION WITH REPORTS OF 6-10+ INCHES OF RAIN PER
RECENT LSR REPORTS NEAR CRYSTAL CITY. VERY EFFICIENT RAINFALL
RATES AVERAGING 1-2 IN/HR SINCE ABOUT 12Z HAVE OCCURRED...COURTESY
OF PRECIPITABLE WATER VALUES BETWEEN 2.00-2.25 IN PER RECENT
BLENDED TPW IMAGERY AND ADDED UPPER LEVEL MOISTURE DOWNWIND OF
T.S. OCTAVE LOCATED IN THE EASTERN PACIFIC...JUST SOUTHWEST OF THE
BAJA PENINSULA. 1000-3000 J/KG MIXED LAYER CAPE CONTINUES TO BE
PRESENT TO THE SOUTH OF THE OUTFLOW BOUNDARY OVER EXTREME SOUTH
TEXAS...AIDED BY DEWPOINTS IN THE LOW TO MID 70S AND MOSTLY SUNNY
SKIES.


WITH 850 MB FLOW FROM THE SOUTHEAST AT 20-30 KTS PER KDFX VAD WIND
PROFILE...AND THE RAP CONTINUING TO SHOW THIS AS BEING UNCHANGED
THROUGH 00Z...CONVECTION IS EXPECTED TO PERSIST WELL INTO THE
EVENING...AND PERHAPS SHIFTING EAST A BIT WITH THE MEAN FLOW.
ONGOING CONVECTION OVER THE THREAT AREA MAY IMPEDE BETTER MOISTURE
RETURN AND CONVECTIVE RAINS FARTHER NORTH AT LEAST IN THE SHORT
TERM...UNTIL THE APPROACH OF A LARGE SHORTWAVE TROUGH CURRENTLY
SLIDING EAST FROM THE GREAT BASIN WHICH SHOULD ALLOW LOW LEVEL
WINDS TO VEER TONIGHT. UNTIL THEN...EXPECT CONTINUED RAINFALL
RATES OF 2-3 IN/HR ON A LOCALIZED BASIS WITH CONTINUED RUNOFF
ISSUES.

OTTO

ATTN...WFO...CRP...EWX...SJT...
 

[Srain]

 
MESOSCALE PRECIPITATION DISCUSSION 0277
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
410 PM EDT SUN OCT 13 2013

AREAS AFFECTED...RIO GRANDE VALLEY INTO CENTRAL TEXAS

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

VALID 132010Z - 140210Z

SUMMARY...HEAVY RAIN IS EXPECTED TO CONTINUE JUST NORTH OF AN
OUTFLOW BOUNDARY ACROSS SOUTHWESTERN TEXAS FOR THE NEXT FEW HOURS
ON TOP OF ALREADY SATURATED SOILS...WHICH WILL PROLONG THE FLASH
FLOOD THREAT INTO THE EVENING.

DISCUSSION...19Z SURFACE ANALYSIS SHOWED A WELL DEFINED OUTFLOW
BOUNDARY BETWEEN LRD AND COT...EXTENDING EAST TOWARD MATAGORDA
BAY...WITH LITTLE TO NO MOVEMENT SEEN OVER THE PAST COUPLE OF
HOURS. A CONVECTIVE CLUSTER HAS BEEN ONGOING SINCE THE EARLY
MORNING ACROSS THE REGION WITH REPORTS OF 6-10+ INCHES OF RAIN PER
RECENT LSR REPORTS NEAR CRYSTAL CITY. VERY EFFICIENT RAINFALL
RATES AVERAGING 1-2 IN/HR SINCE ABOUT 12Z HAVE OCCURRED...COURTESY
OF PRECIPITABLE WATER VALUES BETWEEN 2.00-2.25 IN PER RECENT
BLENDED TPW IMAGERY AND ADDED UPPER LEVEL MOISTURE DOWNWIND OF
T.S. OCTAVE LOCATED IN THE EASTERN PACIFIC...JUST SOUTHWEST OF THE
BAJA PENINSULA. 1000-3000 J/KG MIXED LAYER CAPE CONTINUES TO BE
PRESENT TO THE SOUTH OF THE OUTFLOW BOUNDARY OVER EXTREME SOUTH
TEXAS...AIDED BY DEWPOINTS IN THE LOW TO MID 70S AND MOSTLY SUNNY
SKIES.


WITH 850 MB FLOW FROM THE SOUTHEAST AT 20-30 KTS PER KDFX VAD WIND
PROFILE...AND THE RAP CONTINUING TO SHOW THIS AS BEING UNCHANGED
THROUGH 00Z...CONVECTION IS EXPECTED TO PERSIST WELL INTO THE
EVENING...AND PERHAPS SHIFTING EAST A BIT WITH THE MEAN FLOW.
ONGOING CONVECTION OVER THE THREAT AREA MAY IMPEDE BETTER MOISTURE
RETURN AND CONVECTIVE RAINS FARTHER NORTH AT LEAST IN THE SHORT
TERM...UNTIL THE APPROACH OF A LARGE SHORTWAVE TROUGH CURRENTLY
SLIDING EAST FROM THE GREAT BASIN WHICH SHOULD ALLOW LOW LEVEL
WINDS TO VEER TONIGHT. UNTIL THEN...EXPECT CONTINUED RAINFALL
RATES OF 2-3 IN/HR ON A LOCALIZED BASIS WITH CONTINUED RUNOFF
ISSUES.

OTTO

ATTN...WFO...CRP...EWX...SJT...
 

[Srain]

All the ingredients for a classic October Flood event are developing across a large portion of the Lone Star State later today. Rich tropical moisture is streaming inland off the Gulf with PW's near or above 2 inches which is 2 Standard Deviations above normal, mid/high level EPAC tropical moisture from Octave and a slow moving frontal boundary are all combining from the Edwards Plateau, Hill Country and on NE toward the Arklatex that may generate efficient rainfall rates of 1-2 inch per hour with isolated 3-5 inch per hour rates across areas that saw in excess of 12 inches of rainfall last Saturday night/early Sunday near the Austin Area.

[Srain]

From Nesdis:

 

SATELLITE PRECIPITATION ESTIMATES..DATE/TIME 10/15/13 1206Z
SATELLITE ANALYSIS BRANCH/NESDIS---NPPU---TEL.301-683-1404
LATEST DATA USED: GOES-13 1145Z GOES-15 1141Z WARREN
.
LOCATION...ARKANSAS...TEXAS...OKLAHOMA...
.
ATTN WFOS...LZK...SHV...TSA...FWD...OUN...EWX...SJT...LUB...MAF...
ATTN RFCS...LMRFC...ABRFC...WGRFC...
.
EVENT...HEAVY RAINS
.
SATELLITE ANALYSIS AND TRENDS...EARLY STAGES OF ANTICIPATED NEXT ROUND
OF HEAVY RAINS DEVELOPING ACROSS PORTIONS OF SOUTHWEST AND CENTRAL TX
THIS MORNING. LATEST WATER VAPOR LOOP SHOWS TWO SHORTWAVE IMPULSES
RIDING ALONG RATHER MOIST BAROCLINIC ZONE...ONE CROSSING THE SRN TX
PANHANDLE...WHILE THE SECOND...FARTHER S IS JUST EMERGING FROM MEXICO
ACROSS SW TX. SHOWERS AND TSTMS BREAKING OUT ALONG SFC FRONTAL BOUNDARY
ACROSS N-CENTRAL TX HAVE SHOWN LITTLE EWD PROGRESSION OVER THE PAST HR.
SFC MOISTURE CONVERGENCE AHEAD OF FRONT IS RATHER IMPRESSIVE WITH SWRLY
25 KT FLOW AT 85H PER VWPS. BLENDED TPW PRODUCT SUGGESTS MAX VALUES
STRETCHING ACROSS CENTRAL TX AROUND 1.7". HIGH CLOUDS STREAMING ACROSS
NRN TX ARE OBSCURING ANY GOOD CLOUD SIGNATURES IN IR IMAGERY...HOWEVER
FARTHER S AHEAD OF THAT SECOND SHORTWAVE TEXTURED AND COOLING CLOUD
TOPS ARE NOTED OVER TERRELL/CROCKETT/IRION COUNTIES. BOTH AREAS
OF SHOWERS/TSTMS ARE BECOMING MORE ELONGATED WITH TIME FROM SW TO
NE...INCREASING THE THREAT OF TRAINING.
.
AN ANNOTATED SATELLITE GRAPHIC SHOWING THE HEAVY PRECIPITATION
THREAT AREA SHOULD BE AVAILABLE ON THE INTERNET ADDRESS LISTED
BELOW IN APPROXIMATELY 10-15 MINUTES.
.
SHORT TERM OUTLOOK VALID 1200-1800Z...MEDIUM-HIGH CONFIDENCE FACTOR
IN SHORT TERM OUTLOOK...UL DIFFLUENCE AND VERTICAL ASCENT IS EXPECTED TO
STRENGTHEN THROUGHOUT THE MORNING INTO THE AFTERNOON ACROSS CENTRAL TX
AHEAD OF MID TO UL LOW CROSSING NRN MEXICO...OF WHICH ARE THE REMNANTS
OF OCTAVE. MULTIPLE SHORTWAVES OUT AHEAD OF MID TO UL LOW SHOULD CONTINUE
TO PROVIDE SUPPORT TO DEVELOPING AREAS OF SHOWERS/TSTMS ACROSS CENTRAL TX
THIS MORNING. GREATEST CONCERN IS TRAINING OF HEAVY RAINS IN RELATIVELY
UNIFORM SW TO NE FLOW MID TO UL REGIME. THE SRN CLUSTER OF SHOWERS/TSTMS
APPEARS TO BE THE BEST ORGANIZED ATTM AND IS LIKELY PRODUCING RAINFALL
RATES NEARING 1.75-2.0"/HR. LLVL MOISTURE FROM OCTAVE DOES NOT APPEAR TO
HAVE MADE IT ACROSS THE MOUNTAINS OF NRN MEXICO...BUT THIS IS EXPECTED
LATER IN THE DAY...LIKELY COINCIDING WITH MID TO UL LOW RIDING ALONG
FRONTAL BOUNDARY ACROSS CENTRAL TX...LEADING TO POSSIBLE WIDESPREAD
MODERATE TO HEAVY RAINS FROM CENTRAL TX THROUGH SE OK/SW AR.

 

 

 

[Srain]

Morning update from Jeff (Harris County Flood Control District):

 

Factors coming together to produce another heavy to excessive rainfall event from late this afternoon into tonight across central and N TX and possibly into the northern counties of SE TX.

 

Cold front surging southward this morning extending from near Lubbock to Norman will continue southward today reaching N and C TX this afternoon. TD Octave is making landfall along the Baja of Mexico and spreading mid and upper level moisture NE across TX ahead of the frontal boundary. Upper level ridging is nosing into the coastal areas from the Gulf of Mexico along with a slightly drier air mass.

 

Expect a significant increase in thunderstorm activity this afternoon along the frontal boundary from SW TX to the Dallas area where slow moving excessive rainfall will be possible. PWS at or above 2.0 inches support an excessive rainfall threat and slow storm motions may result in several inches. Flash Flood watches are in effect for central TX where flooding rainfall occurred on Sunday and river flood waves are still working downstream.

 

Expect a band of convection with heavy rainfall to move into SE TX overnight and gradually weaken as the best upper level support remains north of I-10 and greatest moisture is found in roughly the same area. Moisture will decrease toward the coast and expect a fairly strong rainfall gradient of 2-3 inches over our northwest counties to possibly less than .25 of an inch along the coast. Soils are fairly wet over the NW counties where heavy rains fell on Saturday and Sunday and additional rainfall will run-off possibly causing some localized flooding concerns. At this time it appears most of the excessive rainfall will remain north and west of the metro areas.

 

Cold front pushes off the coast on Wednesday with much cooler conditions. Main upper level trough lags well behind the boundary over the SW US keeps a moist Pacific flow in place in the upper levels. Expect only a gradual tapering of light rain on Wednesday into early Thursday. It will be much cooler with cloudy skies and north winds and expect some areas will remain in the 60’s on Wednesday. Dry period Thursday-Friday will be short lived as the main trough over the SW US ejects a strong short wave trough across TX on Friday into Saturday. Coastal trough will be forced off the lower TX coast which will encourage moisture to flow up and over the surface cool dome. Expect showers and thunderstorms to develop from the coastal bend NE into SE TX Friday afternoon into Saturday morning. Could see a few strong storms given some elevated instability.

 

Still does not look to really clear out even behind this short wave as the main upper trough remains anchored to our west continuing a moist flow over the top of the cool dome at the surface keeping mostly cloudy and cool conditions in place. A much stronger front at some point next week may finally push the clouds and moisture south of the area.   

 

[Srain]

From MAF via facebook re: frontal roll cloud...

[Quixotic1]

From MAF via facebook re: frontal roll cloud...

nice shot.

[WishingForWarmWeather]

Just saying "Hi" from San Antonio, and thanking y'all for the great information!

We are under a flash flood warning since 45 minutes ago, although not a drop of rain has fallen all day.  Supposedly supposed to start later this evening.

 

Thanks again, and stay dry y'all!

[WishingForWarmWeather]

From MAF via facebook re: frontal roll cloud...

 

Wow.  That is gorgeous.

 

Forgive my ignorance, but, what is MAF?

[Ed Lizard]

Midland.

[DoctorMu]

With ENSO allegedly stuck in neutral and AO+ possible and ice/snow cover tracking hard south, I really like Roger Smith's amplified model and not so much TWC and NOAA guesses. The Midwest seems like it's going to be slammed.    

 

We could have wide variability with a few robust northers.  Some cut off lows like late winter 2012.  Thoughts?

 

 

[Quixotic1]

With ENSO allegedly stuck in neutral and AO+ possible and ice/snow cover tracking hard south, I really like Roger Smith's amplified model and not so much TWC and NOAA guesses. The Midwest seems like it's going to be slammed.    

 

We could have wide variability with a few robust northers.  cut off lows like late winter 2012.  Thoughts?

 

 

Well, if you look at the 00z GFS, Roger may be on to something.  I know it's fantasy land but holy moly.  October 22? Snow for Red River Valley?

[bubba hotep]

It was a long bore of a summer but do I smell some fantasy snows out in model land?

[Srain]

It was a long bore of a summer but do I smell some fantasy snows out in model land?

More likely for ABQ/AMA/LUB depending on just how the cut off low actually develops across the 4 Corners. The GFS solution does bring a surge of cold Canadian air very far S while the Euro holds back the 5H low spreading moisture over a shallow cold layer near the surface with potential EPAC Raymond moisture streaming ENE. That said it does appear there may be a Winter Storm potential brewing for the Southern Rockies and a strong squall line developing ahead of the sharp cold front typical of a true `Blue Norther' for the Region. 

[DoctorMu]

SW dumped 2.07 in of rain in the backyard.  That's 8.85 in total in a drought busting Oct...following a very welcom 7.03 in in Sept.

 

The tropics came through, but by the backdoor as EPAC storms Manuel and Octave moisture accounted for 8.9 in of the 2 month total.

 

 

Deep Gulf moisture and a cold front set up for more precip around Halloween.

[1900hurricane]

As if this incoming airmass isn't saturated enough, it looks like we will be getting mid/upper level moisture streaming off of Raymond as well. Looks like areas in Texas roughly east of I-35 and north of I-10 have a good shot at a multi-inch rain event, and with some spots in NETX getting walloped by some local 5+" rainfall totals.

[somethingfunny]

When did MAF and SJT start using complete sentences with a full range of punctuation AND LOWERCASE LETTERS?  I'm actually so accustomed to reading ALL CAPS SHORTHAND that I'm having trouble reading these AFDs.

 

 

 

.PREV DISCUSSION... /ISSUED 334 PM CDT TUE OCT 29 2013/

SHORT TERM...(Tonight and Wednesday)

Rain chances for West Central Texas look promising for the next 24
hours. The GFS is more aggressive than the NAM in generating QPF;
the NAM QPF continues to be especially spotty for tonight. However,
mass divergence aloft does look somewhat better on both models this
run. So, I`m going to continue the best rain chances for the Big
Country and for mainly after midnight. For tomorrow, a surface
trough just to our west, across the Trans-Pecos Region and Permian
Basin, will help with low-level convergence. Plus, the GFS and NAM
forecast soundings indicate precipitable water values around 1.4
inches from 06z tonight into tomorrow morning. Although the severe
threat is low, I think we might have a few severe thunderstorms,
mainly after midnight tonight and tomorrow. If so, large hail and
damaging winds will be the main threats. Also, some thunderstorms
may produce heavy rainfall.

Huber

LONG TERM...(Wednesday night through Tuesday)

An unsettled pattern will continue through the extended forecast.
Precipitation chances will continue across much of the area on
Wednesday night before a Pacific front moves through, resulting in
an intrusion of drier air. Scattered showers and thunderstorms will
be possible ahead of the front, with a better chance as the front
moves through the area. The 3km Texas Tech WRF is developing
convection along the front, mainly along and east of Sweetwater, to
San Angelo, to Sonora line. I have indicated the best PoPs along and
east of here, with slight chance across the western counties. Modest
instability and 0-6 KM bulk shear values of 40 to 55 knots could
yield a few strong to severe thunderstorms. Although a few severe
storms will be possible, I think the bigger threat will be locally
heavy rainfall.

[Srain]

Evening update from Jeff L (Harris County Flood Control District)

Heavy Rainfall and flooding possible Wednesday/Thursday.

Factors coming together to produce a period of excessive rainfall across much of eastern TX over the next 36 hours. A powerful upper level storm system over the SW US will be moving into the southern plains on Wednesday and this will send a slow moving frontal boundary southward into TX. Tremendous tropical moisture advection from the NW Caribbean to the TX coast along with moisture streaming NE from EPAC tropical cyclone Raymond will push PWS into the maximum category for this time of year. PWS are forecasted to exceed 2.0 inches and may reach 2.3 inches which put in other words will be August like “tropical moisture” being worked on by strong winter like dynamics. A strong low level jet of 40-50kts will develop on Wednesday and help feed a continuous supply of tropical moisture northward into developing convection. Upper level winds will become increasingly divergent favoring sustained lift and the approaching frontal boundary/any meso scale outflow boundaries will aid in strong low level lift. Everything appears in place for a classic high rainfall/flash flood event over NE TX into SE TX.

Expect disturbances riding up in the SW flow aloft to begin to develop showers and thunderstorms Wednesday morning with rain chances increasing during the day. Expect fairly fast storm motions to limit rainfall amounts on Wednesday, but this will only help wet an already wet ground over the area. Main event looks to be late Wednesday night into much of Halloween. Slow motion frontal boundary will focus deep and near continuous convection with excessive rainfall rates. Upper flow nearly parallel to the boundary supports prolonged cell training of excessive rainfall. Saturated forecast profiles and deep warm layer will support little evaporation and maximum rainfall production from storm cores. Hourly rates of 2-3 inches are likely under the heavy rain cores.

Widespread rainfall of 2-3 inches is becoming likely with isolated totals up to 6 inches. Focused cell training will determine where these maximum amounts fall, but best estimations at the moment are north of I-10 where dynamics will be the strongest. Exact location of any flooding rainfall will not be known until the event is well underway and training bands establish. Given the recent rainfall and wet grounds, run-off generation will be greater than the previous events in October. Additionally, the widespread nature of this event will likely impact river conditions with rises likely on most mainstem points. Urban flooding will also be possible given the high hourly rainfall rates.

A marginal severe weather threat will also reside across mainly the eastern and northeastern parts of the area…roughly from College Station to Conroe to Galveston. Low level shear does become fairly strong Thursday morning, but instability is lacking. Such dynamic systems in very moist air masses can produce low topped supercells that produce brief weak tornadoes. Not looking at widespread severe weather, but a weak tornado or two/or a damaging wind gust is possible.

Halloween Evening

Larger scale models are a little faster at pushing the large rainfall axis toward the coast by sunset on Thursday. Some of the shorter range models are slower and keep widespread activity going into the evening hours. With meso scale processes likely guiding some of the activity on Thursday, I would not put much faith in any particular model solution nor attempt to time the exact rainfall ending time. Do think the NW counties will likely be drying out by 5-6pm, metro Houston is much more debatable, and the coast looks fairly wet. Will not have much better timing until likely Thursday morning to see how the activity evolves during the day.

 

[DoctorMu]

EPAC Tropics + STJ strike again.  a remarkable Fall

 

[wall_cloud]

When did MAF and SJT start using complete sentences with a full range of punctuation AND LOWERCASE LETTERS?  I'm actually so accustomed to reading ALL CAPS SHORTHAND that I'm having trouble reading these AFDs.

 

Actually, we (along with a handful of other offices spread throughout the country) are part of a "mixed case" test.  I have to admit that writing in mixed case took a bit of adjusting even though we do it in everyday life all the time.  So many acronyms and abbreviations were automatically capitalized and it added a new thought process when typing them as mixed case.  We've been writing them this way since the beginning of August.

[Srain]

The radar trends this morning are a bit worrisome. It appears that PW's of 2.5 Inches has arrived earlier than expected and the storm system near the 4 Corners and associated cold front to our W is still about 36 hours away. I would not be surprised to see Flash Flood Watches extended E and hoisted for a large potion of SE Texas and Louisiana later today. Keep an eye on the weather as we near the evening drive time and tonight when convective activity will likely ramp up and more widespread heavy training rainfall begins in earnest as the remnants of EPAC cyclone Raymond and a strong vort max at the base of the deep Western trough with its addtional lifting mechanism combine to allow a classic October Texas flood event to unfold. We have seen a lot of rainfall across much of Texas the last 30 days and the drought that had been present across much of the Region has been eliminated.

[Ed Lizard]

http://abclocal.go.com/ktrk/story?section=news/local&id=8496325

 

I remember that day.  I was interested on the KHOU-TV 11 forum for several days,  Meager instability, but lots of helicity and very low cloud bases, several EF-0s and EF-1s.

 

 

And I shake the hand of an atmosphere that can pull off an August 2.2 PW last day of October.

 

Prefer all caps AFDs, easier to read...

[Ed Lizard]

The radar trends this morning are a bit worrisome. It appears that PW's of 2.5 Inches has arrived earlier than expected and the storm system near the 4 Corners and associated cold front to our W is still about 36 hours away. I would not be surprised to see Flash Flood Watches extended E and hoisted for a large potion of SE Texas and Louisiana later today. Keep an eye on the weather as we near the evening drive time and tonight when convective activity will likely ramp up and more widespread heavy training rainfall begins in earnest as the remnants of EPAC cyclone Raymond and a strong vort max at the base of the deep Western trough with its addtional lifting mechanism combine to allow a classic October Texas flood event to unfold. We have seen a lot of rainfall across much of Texas the last 30 days and the drought that had been present across much of the Region has been eliminated.

 

 

As of last evening, 2 inch PWs were already about to CRP and advectng North.  I just wish this image updated more frequently,  But 12Z BRO, LCH and CRP soundings should be fun to look at...

[1900hurricane]

Both members of the 00Z NMM/ARW comparison did a fair job picking up the east Texas storm cluster (better than the 4 km NAM and the Globals at least), although it was perhaps a little slow. Here is what it showed at 14Z:

 

[Srain]

The HPC has just updated their Excessive Rainfall Outlook for Day 1 and have shifted the Slight Risk further S and W to include the NW portion of SE Texas as well as all of Central Texas.

[Srain]

From Nesdis:

 

SATELLITE PRECIPITATION ESTIMATES..DATE/TIME 10/30/13 1428Z
SATELLITE ANALYSIS BRANCH/NESDIS---NPPU---TEL.301-683-1404
LATEST DATA USED: GOES-E 1415Z LP
.
LOCATION...LOUISIANA...MISSOURI...ARKANSAS...TEXAS...
LOCATION...OKLAHOMA...KANSAS...
.
ATTN WFOS...LZK...SGF...LCH...SHV...EAX...TSA...HGX...TOP...ICT...
ATTN WFOS...FWD...OUN...EWX...
ATTN RFCS...LMRFC...MBRFC...ABRFC...WGRFC...
.
EVENT... HIGH MOISTURE AND HEAVY RAINS
.
SATELLITE ANALYSIS AND TRENDS... UL LOW CURRENTLY CENTERED OVER EXTREME
SOUTHERN NEVADA SWINGING INTO WESTERN ARIZONA CLEARLY SEEN IN RGB AIRMASS
PRODUCT. MID-UL MOISTURE PLUME VISIBLE IN WV IMAGERY IS DRAWING FROM
TROPICAL DEPRESSION RAYMOND AND  SPREADING ACROSS TEXAS AND THE SOUTHERN
PLAINS. ADDITIONALLY A STRONG SOUTHWESTERLY LLJ IS FEEDING TROPICAL
MOISTURE INTO THE SAME REGION WITH THE AXIS OF HIGHEST
MOISTURE CURRENTLY NOSING INTO SOUTHEASTERN OKLAHOMA/WESTERN
ARKANSAS. SATELLITE BLENDED TPW SHOWING WIDESPREAD VALUES OF 1.5" ACROSS
EAST TEXAS AND SOUTHERN OKLAHOMA AND IS EXPECTED TO CONTINUE INCREASING
TODAY. LATEST IR IMAGERY SHOWING CLOUD TOP COOLING OCCURRING ALONG THE
LL MOISTURE AXIS MOST NOTABLY IN SOUTHEAST TEXAS AND CENTRAL OKLAHOMA.
.
AN ANNOTATED SATELLITE GRAPHIC SHOWING THE HEAVY PRECIPITATION
THREAT AREA SHOULD BE AVAILABLE ON THE INTERNET ADDRESS LISTED
BELOW IN APPROXIMATELY 10-15 MINUTES.
.
SHORT TERM OUTLOOK VALID 1430-1830Z...MEDIUM CONFIDENCE FACTOR
IN SHORT TERM OUTLOOK... RAPID CLOUD TOP COOLING IN LAST FEW HOURS IN
SOUTHEAST TEXAS INCREASING IN SCALE AND STEADILY MOVING NORTHWARD INTO
NORTHEAST TEXAS/SOUTHEAST OKLAHOMA/SOUTHWEST ARKANSAS. ADDITIONAL COLD
TOP COOLING NOW OCCURRING JUST TO WEST OF COLDEST TOPS. EXPECT RAINS
TO BE PERSISTENT GIVEN LARGE COVERAGE WITH RATES OF 1.0-1.5"/HR IN
HEAVIER BURSTS. ALSO CONCERN FOR ACTIVE CONVECTION DEVELOPING ACROSS
CENTRAL/NORTHEAST OKLAHOMA. IT IS ORIENTED SOUTHWEST-NORTHEAST AND
IS TRAINING AS IT MOVES TOWARD THE NORTHEAST INTO AREAS OF LOWER
FFG IN SOUTHEAST KANSAS AND SOUTHWEST MISSOURI (WHICH RECEIVED HEAVY
RAINS YESTERDAY MORNING). EXPECT RATES ASSOCIATED WITH STRONG CELLS
TO BE 1.0-1.25"/HR. WITH ANOMALOUS MOISTURE INCREASING THROUGHOUT THE
DAY... HEAVY RAIN THREAT WILL CONTINUE AS UL LOW BEGINS TO AFFECT REGION
LATER TODAY AND TONIGHT.

 

 

[Srain]

MESOSCALE DISCUSSION 1982
   NWS STORM PREDICTION CENTER NORMAN OK
   1245 PM CDT WED OCT 30 2013

   AREAS AFFECTED...SE...CNTRL AND NRN TX

   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

   VALID 301745Z - 301915Z

   PROBABILITY OF WATCH ISSUANCE...40 PERCENT

   SUMMARY...A SEVERE THREAT MAY DEVELOP THIS AFTERNOON FROM SE TX
   NNWWD INTO NCNTRL TX. WIND DAMAGE AND PERHAPS AN ISOLATED TORNADO
   THREAT WILL BECOME POSSIBLE AS CELLS INITIATE. WW ISSUANCE MAY BE
   NEEDED ESPECIALLY IF A CLUSTER OF STORMS CAN INTENSIFY AND BECOME
   ORGANIZED.

   DISCUSSION...THE LATEST SFC ANALYSIS SHOWS A CORRIDOR OF LOW-LEVEL
   MOISTURE EXTENDING WWD FROM THE HOUSTON AREA INTO THE TX HILL
   COUNTRY AND NWD TO NEAR THE RED RIVER. THE AIRMASS IS VERY MOIST
   WITH SFC DEWPOINTS RANGING FROM THE MID 70S F IN SE TX TO THE UPPER
   60S F ACROSS NCNTRL TX. IN ADDITION...VISIBLE SATELLITE SHOWS BREAKS
   IN THE CLOUD COVER ALONG THIS CORRIDOR WHICH HAS ENABLED SFC TEMPS
   TO WARM INTO THE MID TO UPPER 70S F. THIS HAS HELPED ENHANCE
   INSTABILITY WITH SBCAPE VALUES ESTIMATED IN THE 1000 TO 2000 J/KG
   RANGE. CONTINUED SFC HEATING MAY ALLOW FOR THE INITIATION OF
   SFC-BASED STORMS ACROSS THE MCD AREA DURING THE MID-AFTERNOON AS IS
   SUPPORTED BY THE LATEST HRRR RUN AND ECMWF. ALSO...SFC WINDS ARE
   BACKED TO THE SOUTHEAST ACROSS MOST OF THE MCD AREA. THIS IS HELPING
   TO ENHANCE LOW-LEVEL SHEAR WHICH ALONG WITH 0-6 KM SHEAR IN THE 45
   TO 50 KT RANGE....SHOULD BE ENOUGH FOR CELL ROTATION AND POSSIBLY AN
   ISOLATED TORNADO THREAT. THE MOIST BOUNDARY LAYER MAY ALSO RESULT IN
   A POTENTIAL FOR WET DAMAGING OUTFLOW GUSTS.

   ..BROYLES/CORFIDI.. 10/30/2013


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

[1900hurricane]

The NWS out of Fort Worth has made an interesting observation about some dry air coming out from the Del Rio area in their latest Forecast Discussion. They are currently hypothesizing that the heaviest rain may set up across central Texas near the edge of the dry air. The high resolution models such as the 12Z 4 km NAM and both the ARW and the NMM may be picking up on this, as they have placed the highest QPF further south than the globals have been showing over the past couple of days.

 

 

[Ed Lizard]

Stolen from Texas Storm Chasers...

 

 

 

My water oak has about 20% of its original green leaves left, and well, this is good.

[Srain]

The over night guidance continues to advertise a very unsettled pattern as we head into the first week of November. Yet another deep Western trough develops that taps into abundant tropical moisture from the Eastern Pacific suggesting another heavy rainfall threat next Tuesday into Thursday. While it is too soon to know with any certainty exactly how much additional rainfall we will see, the pattern suggests that we may be stuck in a regime where a somewhat blocking pattern evolves where the storm track dips SE into the Great Basin/Inter Mountain West and heads NE from the Southern Plains. We may be able to finally declare the long term Texas/Southern Plains drought over if such a pattern does in fact develop. We will see.