897  
FXUS64 KFWD 271540 AAA  
AFDFWD  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE FORT WORTH TX  
1040 AM CDT WED JUL 27 2016  
   
UPDATE
 
 
MAIN UPDATE THIS MORNING WAS TO ADJUST POPS/WX BASED ON CURRENT  
OBSERVATIONS AND RECENT ANALYSIS/MODEL OUTPUT.  
 
UPPER AIR ANALYSIS IN CONJUNCTION WITH WATER VAPOR IMAGERY  
REVEALED A MID-LEVEL DEFORMATION ZONE EXTENDED FROM THE CONCHO  
VALLEY BACK UP TOWARDS THE ARK-LA-TEX. SIMILAR TO YESTERDAY, THIS  
FEATURE IN COMBINATION WITH DAYTIME HEATING SHOULD BE ENOUGH TO  
ENCOURAGE SCATTERED CONVECTION LATE THIS MORNING AND INTO THE  
AFTERNOON HOURS. THE BETTER THREAT FOR RAIN AND THUS HIGHEST POPS  
ARE CONFINED TO AN AREA ALONG THE AFORMENTIONED DEFORMATION AXIS.  
I HAVE NUDGED POPS UPWARDS INTO THE LIKELY CATEGORY FOR MOST  
AREAS ALONG THE RED RIVER WITH LOWER RAIN CHANCES FURTHER SOUTH  
TOWARDS CENTRAL TX WHERE WV IMAGERY INDICATES DRIER MID-LEVEL  
AIR. DESPITE THIS MID-LEVEL DRY AIR, DIURNAL SEA-BREEZE ACTIVITY  
AND SUBSEQUENT CONVECTIVE OUTFLOWS MAY STILL SUPPORT SOME  
SCATTERED CONVECTION AND I WILL KEEP A MENTION OF SHOWERS AND  
STORMS HERE. WITH REGARDS TO HAZARDS...THE 12 UTC FWD RAOB SAMPLED  
AN ENVIRONMENT CHARACTERIZED BY 2" PW VALUES. THIS COMBINED WITH  
THE WEAK DEEP LAYER SHEAR AND THUS MINIMAL DRY AIR ENTRAINMENT AND  
GIVEN EXPECTED SLOW STORM MOTIONS---A HEAVY RAIN AND A MINOR  
FLOOD THREAT WILL LIKELY DEVELOP. GIVEN THE MOIST ENVIRONMENT,  
THERE DOES REMAIN SOME POTENTIAL FOR A STRONG DOWNBURST OR TWO DUE  
MAINLY TO PRECIPITATION LOADING. IF STORMS CAN SURVIVE THE HOSTILE  
ENVIRONMENT ACROSS THE SOUTHEASTERN ZONES, A SLIGHTLY HIGHER RISK  
FOR DOWNBURSTS WILL EXIST HERE. OTHERWISE, HEAVY RAIN WILL BE THE  
MAIN HEADLINE FOR TODAY.  
 
I HAVE CAUTIOUSLY LOWERED TEMPERATURES ALONG THE RED RIVER WHERE  
CLOUD COVER AND RAIN SHOULD KEEP TEMPERATURES IN THE LOW TO MID  
90S HERE. GIVEN THE TIME OF YEAR, HOWEVER, IT WILL ONLY TAKE A FEW  
HOURS OF SUNSHINE TO SEND TEMPERATURES SOARING INTO THE MID 90S.  
 
THE REMAINDER OF THE FORECAST APPEARS TO BE IN GREAT SHAPE AND  
UPDATED PRODUCTS HAVE BEEN SENT.  
 
24-BAIN  
 

 
   
AVIATION
 
 
/ISSUED 646 AM CDT WED JUL 27 2016/  
MAIN CONCERN FOR THE TAFS TODAY WILL BE THE THUNDER POTENTIAL  
BEGINNING MIDDAY LASTING THROUGH THE EVENING, WITH ANOTHER CHANCE  
FOR STORMS EARLY THURSDAY MORNING.  
 
AS OF 1130Z, SHOWERS AND ISOLATED THUNDERSTORMS HAVE BEGUN TO  
DEVELOP ALONG AN AXIS OF HIGHER MOISTURE DRAPED FROM DFW INTO  
SOUTHWEST MISSOURI. ACTIVITY SHOULD CONTINUE TO EXPAND SOUTHWARD  
LATE THIS MORNING AND EARLY AFTERNOON AS DAYTIME HEATING  
COMMENCES. CONFIDENCE IS HIGH THAT THUNDERSTORMS WILL BE PRESENT  
THIS AFTERNOON AND WILL LIKELY IMPACT TAF SITES INTERMITTENTLY  
THROUGHOUT THE AFTERNOON AND EARLY EVENING, OR POSSIBLY EVEN BY  
LATE MORNING. HOWEVER, DUE TO THE EXPECTED SCATTERED NATURE OF  
THUNDERSTORM ACTIVITY, IT IS MUCH TOO DIFFICULT TO PIN DOWN ONE TIME  
FRAME THAT IS MORE LIKELY THAN ANOTHER, THUS HAVE CHOSEN NOT TO  
INCLUDE AN EXPLICIT TSRA MENTION BUT RATHER SEVERAL HOURS OF VCTS  
AT DFW METROPLEX AIRPORTS. COVERAGE OF CONVECTION SHOULD BE LESS  
ACROSS CENTRAL TEXAS AND HAVE INCLUDED A NARROWED TIME FRAME OF  
21-00Z FOR THE WACO SITE. OTHERWISE, VFR CONDITIONS WITH LIGHT  
SOUTH WINDS WILL PREVAIL OUTSIDE OF THUNDERSTORMS.  
 
THE NEXT FORECAST CHALLENGE IS ADDITIONAL THUNDERSTORM POTENTIAL  
EARLY THURSDAY MORNING AROUND 12Z. THERE ARE SOME INDICATIONS THAT  
EITHER A COMPLEX OF STORMS MAY MOVE SOUTHWARD FROM OKLAHOMA INTO  
NORTH TEXAS OR AT LEAST A BOUNDARY FROM EARLIER CONVECTION MAY BE  
SENT SOUTHWARD WHICH COULD INITIATE NEW CONVECTION IN NORTH  
TEXAS. HAVE INCLUDED ANOTHER VCTS MENTION IN THE EXTENDED DFW TAF  
TO ACCOUNT FOR THIS POTENTIAL. ADDITIONAL AFTERNOON THUNDERSTORMS  
ON THURSDAY ALSO APPEAR LIKELY WHICH WILL BE ADDRESSED IN  
SUBSEQUENT TAFS.  
 
-STALLEY  
 

 
 
   
PREV DISCUSSION
 
/ISSUED 347 AM CDT WED JUL 27 2016/  
 
HOT AND HUMID CONDITIONS ALONG WITH SCATTERED SHOWERS AND  
THUNDERSTORMS WILL CONTINUE FOR A COUPLE MORE DAYS ACROSS NORTH  
TEXAS BEFORE UPPER RIDGING BUILDS BACK IN ACROSS THE SOUTHERN  
PLAINS.  
 
WATER VAPOR IMAGERY SHOWS A WEAK UPPER TROUGH CENTERED OVER  
LOUISIANA THIS MORNING. THIS FEATURE IS EXPECTED TO CONTINUE TO  
SLOWLY MOVE NORTH TODAY. TO THE NORTHWEST OF THE UPPER  
TROUGH...THERE IS A BAND OF MOISTURE ASSOCIATED WITH A MID LEVEL  
DEFORMATION AXIS WHICH EXTENDS FROM SOUTHWEST MISSOURI INTO  
CENTRAL OKLAHOMA AND INTO NORTH TEXAS. 00Z UPPER AIR ANALYSIS AT  
700MB INDICATED THE PRESENCE OF RICH MOISTURE FROM NEAR MIDLAND  
INTO NORTH TEXAS AND EXTENDING INTO THE OZARKS. LATEST RAP  
ANALYSIS INDICATES PW VALUES IN EXCESS OF 2 INCHES ALONG THIS AXIS  
AND ACROSS A GOOD CHUNK OF NORTH TEXAS. AT THE SURFACE...THERE IS  
SOME WEAK TROUGHING NOTED FROM SOUTH OF LUBBOCK TO NEAR WICHITA  
FALLS AND INTO SOUTHERN OKLAHOMA. GIVEN THESE FEATURES...THINK A  
GOOD PORTION OF NORTH TEXAS...ESPECIALLY ACROSS THE NORTHERN HALF  
OF THE CWA...WILL SEE CONVECTION DEVELOP LATER THIS MORNING INTO  
THE AFTERNOON HOURS...SO WE HAVE RAISED POPS TO 40-50%. SOUTH OF  
THE I-20 CORRIDOR THERE MAY BE A RELATIVE MINIMUM IN CONVECTIVE  
COVERAGE WITH THE EXCEPTION OF OUR FAR SOUTHERN COUNTIES. THIS  
AREA MAY SEE SOME ACTIVITY SPREAD NORTH FROM SOUTHEAST TEXAS. ALL  
OF THIS ACTIVITY SHOULD AGAIN BE DIURNALLY DRIVEN WITH A PEAK IN  
COVERAGE LATE THIS AFTERNOON AND DIMINISHING AFTER SUNSET.  
CONDITIONS WILL BE FAVORABLE FOR ISOLATED STRONG DOWNBURST WINDS  
AND LOCALLY HEAVY RAINFALL.  
 
LATER TONIGHT...A SECOND SHORTWAVE TROUGH WILL SWING THROUGH THE  
CENTRAL PLAINS AND INTO NORTHERN OKLAHOMA WITH NORTHERLY FLOW AT  
500 AND 700MB INCREASING. THERE IS SOME POTENTIAL FOR A COMPLEX OF  
THUNDERSTORMS TO DEVELOP AND MOVE SOUTH LATE OVERNIGHT ALTHOUGH  
THE LATEST HIGH RESOLUTION GUIDANCE IS LESS BULLISH ON THIS  
SCENARIO. NONETHELESS...WILL HAVE SOME 20% POPS LATE TONIGHT  
MAINLY ALONG AND NORTH OF I-20.  
 
THE MORE LIKELY SCENARIO IS THAT THIS PASSING SHORTWAVE SENDS A  
WEAK BOUNDARY DOWN INTO NORTH TEXAS FOR THURSDAY. WITH RICH  
MOISTURE STILL IN THE REGION...SCATTERED SHOWERS AND THUNDERSTORMS  
WOULD LIKELY DEVELOP ALONG THIS BOUNDARY DURING THE DAY THURSDAY.  
WILL CONTINUE WITH 30-40% POPS DURING THIS TIME ACROSS MUCH OF  
NORTH TEXAS.  
 
BEYOND THURSDAY...UPPER RIDGING BEGINS TO NUDGE BACK EASTWARD INTO  
THE AREA. THIS WILL CONFINE POPS ON FRIDAY MAINLY TO THE EASTERN  
HALF OF THE CWA AND ONLY ACROSS THE FAR NORTHEAST BY SATURDAY.  
TEMPERATURES WILL SLOWLY NUDGE UPWARDS BACK TO NEAR 100 DEGREES  
DURING THIS TIME WITH RAIN CHANCES DIMINISHING TO NEAR ZERO BY THE  
LATTER HALF OF THE WEEKEND. A PAIR OF STRONG SHORTWAVE TROUGHS  
WILL MOVE THROUGH THE NORTHWEST U.S. SUNDAY AND MONDAY WHICH  
SHOULD HELP DEEPEN A SURFACE LOW EAST OF THE ROCKIES. THIS WILL  
KEEP WIND SPEEDS UP A BIT ACROSS NORTH TEXAS SO IT WON'T FEEL TOO  
OPPRESSIVE ACROSS THE REGION.  
 
DUNN  
 

 
 
   
PRELIMINARY POINT TEMPS/POPS
 
 
DALLAS-FT. WORTH 96 77 96 77 97 / 50 50 30 10 20  
WACO 96 77 97 75 99 / 20 20 30 10 20  
PARIS 96 74 93 73 94 / 50 50 40 20 30  
DENTON 93 73 94 74 96 / 60 60 30 10 20  
MCKINNEY 93 75 94 75 95 / 60 60 30 20 20  
DALLAS 96 78 96 76 98 / 50 50 30 10 20  
TERRELL 95 75 94 75 96 / 40 40 40 20 20  
CORSICANA 95 76 96 76 96 / 20 20 40 20 20  
TEMPLE 94 75 96 75 97 / 20 20 30 10 20  
MINERAL WELLS 95 72 95 72 97 / 50 50 30 5 10  
 

 
   
FWD WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
05/24  
 
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