616  
FXUS64 KEWX 291522  
AFDEWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX  
1022 AM CDT WED MAR 29 2017  
   
UPDATE
 
 
THE LINE OF SHOWERS AND THUNDERSTORMS HAS EXITED THE REGION, WITH A  
WEAK FRONTAL BOUNDARY SLOWLY PUSHING EAST OF INTERSTATE 35 BEHIND IT.  
SUBSIDENCE INVERSIONS EVIDENT ON AIRCRAFT SOUNDINGS AT SAT AND AUS  
COUPLED WITH DRY AIR AND NEGATIVE VORTICITY ADVECTION AT MIDLEVELS  
BEHIND THE LINE OF STORMS SHOULD PREVENT ANY CONVECTION FROM  
OCCURRING THIS AFTERNOON ALONG THIS SLOW MOVING FRONT. THEREFORE, WE  
HAVE REMOVED ALL MENTION OF POPS FOR THE REST OF TODAY. PATCHY FOG  
HAS HELD ON A BIT LONGER THAN EXPECTED THIS MORNING OVER PARTS OF THE  
HILL COUNTRY AND BEXAR COUNTY, BUT THIS SHOULD CONTINUE TO LIFT AS  
W-NW WINDS MIX DOWN TO THE SURFACE.  
 
DRY WESTERLY WINDS WITH THE ASSISTANCE OF SOME DOWNSLOPING EFFECTS  
SHOULD STILL HELP HIGHS WARM UP INTO THE LOWER 80S IN THE HILL  
COUNTRY, MID 80S IN THE I-35 CORRIDOR, AND UPPER 80S IN THE RIO  
GRANDE PLAINS. HOWEVER, WE HAVE LOWERED HIGH TEMPERATURES A FEW  
DEGREES BASED ON MODEL TRENDS, WHICH IS LIKELY PICKING UP ON SOME  
MORE SATURATED SOILS WITH THE RAINFALL THAT FELL OVERNIGHT. THE ONE  
AREA WHERE FORECAST HIGHS HAVE NOT REALLY DECREASED TODAY IS OVER  
DIMMIT AND SOUTHERN MAVERICK AND ZAVALA COUNTIES WHICH RECEIVED  
LITTLE OR NO RAINFALL. THESE AREAS MAY STILL WARM UP INTO THE LOWER  
90S TODAY TO ALLOW FOR RELATIVE HUMIDITY VALUES TO DROP INTO THE  
TEENS. FORTUNATELY, WINDS OVER THESE COUNTIES SHOULD REMAIN BELOW  
10-15 MPH TO KEEP FIRE WEATHER CONCERNS MORE IN THE ELEVATED CATEGORY.  
WINDS FURTHER NORTH OVER VAL VERDE COUNTY AND PARTS OF THE EDWARDS  
PLATEAU ARE STILL EXPECTED TO INCREASE TO AROUND 20 MPH WITH GUSTS TO  
30-35 MPH WITH MIN RH VALUES IN THE TEENS AND 20S, BUT LAST NIGHT'S  
WETTING RAINS OF AT LEAST HALF AN INCH IN MOST SPOTS SHOULD KEEP  
FIRE WEATHER CONCERNS MORE IN THE ELEVATED TO NEAR CRITICAL CATEGORY.  
 

 
   
PREV DISCUSSION
 
/ISSUED 626 AM CDT WED MAR 29 2017/  
 
UPDATE...  
12Z AVIATION UPDATE BELOW.  
 
AVIATION...  
A LINE OF TSTMS WILL CONTINUE TO EXIT THE REGION THIS MORNING AND  
NOT IMPACT THE TAF SITES. SOME PATCHY FOG AND LOW CEILINGS ARE  
POSSIBLE THROUGH 13-14Z AT SAT/SSF/AUS RESULTING IN MVFR TO IFR  
CONDITIONS. OTHERWISE VFR CONDITIONS THROUGH THE DAY AND TONIGHT.  
W WINDS DEVELOPING BY AFTERNOON AROUND 10 KTS AT SAT/AUS, BUT  
STRONGER AT DRT WITH SOME GUSTS 20-25 KTS. A SECONDARY COLD FRONT  
THIS EVENING WILL RESULT IN A WIND SHIFT TO THE NW.  
 
PREV DISCUSSION... /ISSUED 355 AM CDT WED MAR 29 2017/  
 
SHORT TERM (TODAY THROUGH THURSDAY)...  
 
AS OF 3 AM, RADAR LOOPS SHOWING THE SOUTHERN PORTION OF THE SQUALL  
LINE TO BE LOSING ITS NEAR SEVERE AND MOSTLY ELEVATED VELOCITY  
SIGNATURES, BUT WILL LEAVE UP THE WATCH ALONG THE FRONT EDGE OVER  
I-35 FOR ANOTHER HOUR. FOLLOWING THE TRENDS OF THE HRRR/RAP, WILL  
SHOW A MORE PROGRESSIVE CLEARING TREND FOR THE MORNING POPS AND PLAN  
ON USING CONSERVATIVE HWO WORDING REGARDING THE LATE MORNING STRONG  
STORM POTENTIAL OVER SOUTHEAST COUNTIES.  
 
CONTINUING THE TREND ON TEMPERATURES, EARLIER CLEARING SHOULD  
TRANSLATE TO WARMER THAN BLENDED GUIDANCE MAX TEMPS FOR TODAY. GOOD  
MIDDAY PACKING OF ISOBARS OVER THE EDWARDS PLATEAU SHOULD ENHANCE  
MIXING AND DROP RH VALUES IN THE LOW TEENS ALONG THE RIO GRANDE,  
WHILE PICKING SURFACE WINDS TO AROUND 20 MPH WITH GUST OVER 35 MPH NW  
OF DRT. RADAR PRECIP ESTIMATES SUGGEST ALL OF VAL VERDE COUNTY HAD  
RECEIVE OVER 0.2 INCHES OF RAIN WITH THE DRIER 10-HOUR FUEL MOISTURE  
AREAS AROUND DRT HAVING A LITTLE MORE. THUS WILL EXPECT THIS MOISTURE  
TO OFFSET THE CRITICAL FIRE WEATHER CONDITIONS FORECAST FOR WESTERN  
VAL VERDE COUNTY AND SETTLE ON A NEAR CRITICAL WORDING. FARTHER EAST  
AND SOUTH, WINDS AND ESPECIALLY GUSTS SHOULD DROP OFF TO LOWER  
VALUES. NW BOUNDARY LAYER TO 850 MB WINDS AT 20 TO 35 MPH SHOULD  
ENHANCE COOLING AND DRYING ACROSS THE REGION, LEAVING A SEASONAL  
MORNING LOW IN THE UPPER 40S NORTH TO MID 50S SOUTHEAST. WESTERLY  
TRANSPORT WINDS RESUMING FOR WEDNESDAY WILL BE MUCH LIGHTER BUT  
SHOULD STILL BRING AFTERNOON TEMPS BACK TO ABOVE NORMALS.  
 
LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...  
 
LIGHT WINDS SHOULD CONTINUE THURSDAY NIGHT, AND THERE MAY ENOUGH  
GROUND MOISTURE FOR SOME PATCHY GROUND FOG GIVEN THE RAINS. WILL KEEP  
WITH THE MODEL DATA AND LEAVE OUT FOR NOW. RETURNING SOUTH WINDS  
FRIDAY WILL ACCELERATE LATE IN THE DAY AS ANOTHER LARGE UPPER LOW  
DROPS SOUTHEAST ACROSS THE GREAT BASIN TOWARDS TX. INITIALLY, THE  
MID LEVELS OF THE ATMOSPHERE WILL BE VERY DRY, SO THERE SHOULD STILL  
BE ABUNDANT SUNSHINE AND WARM TEMPS FOR FRIDAY. CONTINUED DEEPENING  
OF THE LOW LEVEL MOIST LAYER AND CLOSER APPROACH OF THE UPPER LOW  
WILL LIKELY BRING A MOSTLY CLOUDY AND NOT AS WARM DAY SATURDAY, WITH  
A DRYLINE FEATURE SUGGESTED TO SET UP OVER CENTRAL TX IN THE AFTERNOON  
BY DETERMINISTIC MODELS. AS SUGGESTED IN THE SPC EXTENDED OUTLOOKS,  
INSTABILITY AND WIND SHEAR WOULD LIKELY BE SUFFICIENT FOR A FEW  
SEVERE STORMS. CONTINUED SEWD DIGGING OF THE UPPER LOW IS THEN  
EXPECTED TO BRING ADDITIONAL ROUNDS OF STORMS FROM THE SW SATURDAY  
NIGHT WITH RAIN STILL LIKELY OVER THE EASTERN TWO-THIRDS OF THE AREA  
SUNDAY. THE REPEATED ROUNDS OF RAIN COULD MEAN SOME LOCALLY HEAVY  
DOWNPOURS OVER 2 INCHES WILL BE POSSIBLE THIS WEEKEND. GFS/ECM  
SOLUTIONS SHOW GOOD AGREEMENT ON THE NORTHEASTWARD EJECTION OF THE  
UPPER LOW SUNDAY EVENING WITH MOSTLY STABLE AND WARM WEATHER TO  
FOLLOW FOR EARLY NEXT WEEK.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
AUSTIN CAMP MABRY 85 54 81 56 87 / 10 - 0 0 0  
AUSTIN BERGSTROM INTL AIRPORT 84 54 80 50 87 / 10 - 0 0 0  
NEW BRAUNFELS MUNI AIRPORT 84 53 81 53 87 / - - 0 0 0  
BURNET MUNI AIRPORT 82 51 77 54 85 / - - 0 0 0  
DEL RIO INTL AIRPORT 86 53 83 57 93 / - 0 0 0 0  
GEORGETOWN MUNI AIRPORT 84 53 79 53 85 / 10 - 0 0 0  
HONDO MUNI AIRPORT 86 52 83 53 89 / 0 0 0 0 0  
SAN MARCOS MUNI AIRPORT 85 53 80 53 87 / 10 - 0 0 0  
LA GRANGE - FAYETTE REGIONAL 84 56 78 54 86 / 50 10 0 0 0  
SAN ANTONIO INTL AIRPORT 87 54 82 55 88 / - - 0 0 0  
STINSON MUNI AIRPORT 86 54 81 55 89 / - - 0 0 0  
 

 
   
EWX WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
MESOSCALE/AVIATION...HAMPSHIRE  
SYNOPTIC/GRIDS...LH  
PUBLIC SERVICE/DATA COLLECTION...YB  
 
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