329  
FXUS64 KAMA 261128 AAA  
AFDAMA  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE AMARILLO TX  
628 AM CDT SUN JUN 26 2016  
   
AVIATION
 
 
THE FOG AT DHT WITH MVFR CONDITIONS SHOULD BE SHORT LIVED, SO HAVE  
NOT INSERTED IT INTO THIS FORECAST. OTHERWISE, VFR CONDITIONS SHOULD  
PREVAIL OUTSIDE OF THUNDERSTORMS AT ALL SITES THROUGH THIS FORECAST.  
THE BEST CHANCE OF THUNDERSTORMS WILL BE THIS EVENING, SO HAVE  
INSERTED A PROB30 AT ALL SITES DURING THIS TIMEFRAME. WINDS WILL BE  
LIGHT AND VARIABLE FOR THE FIRST PART OF THE FORECAST, THEN THEY  
SHOULD BECOME SOUTHEAST, BUT THEY SHOULD REMAIN AROUND 10 KNOTS OR  
LESS.  
 

 
   
PREV DISCUSSION
 
/ISSUED 347 AM CDT SUN JUN 26 2016/  
 
DISCUSSION...  
THUNDERSTORMS FORMED LAST EVENING IN A FAIRLY NARROW CORRIDOR NEAR  
ASURFACE TROUGH THAT EXTENDED FROM NORTHEAST NEW MEXICO INTO  
KANSAS. THIS BOUNDARY PROBABLY HAD SOME TIE TO NORTHERN PLAINS  
SHORTWAVE BUTBAROCLINICITY ALONG THE BOUNDARY WAS WEAK OR NON-  
EXISTENT IN ANALYSIS EARLIER IN THE DAY PRIOR TO CONVECTIVE  
DEVELOPMENT. THUNDERSTORMS BECAME FAIRLY NUMEROUS DURING THE EVENING  
BEFORE DIMINISHING LATER IN THE NIGHT. COLD POOL/MESOHIGH AND  
OUTFLOW HAS MASKED THIS BOUNDARY MAKING IT DIFFUSE AND RECOVERY FROM  
THIS TOMORROW IS IN QUESTION. MODELS VARY IN SURFACE PRESSURE  
PATTERN DEPICTION TOMORROW WITH MOST NOT SHOWING A SYNOPTIC SCALE  
BOUNDARY AND SEVERAL SHOWING AN INCREASINGLY DIFLUENT SURFACE WIND  
FIELD DURING THE AFTERNOON. FOR THIS REASON, HAVE LIMITED  
PRECIPITATION PROBABILITIES TO THE HIGH END OF CHANCE CATEGORY  
DURING THE AFTERNOON AND EVENING. DESPITE LACK OF A NOTEABLE LOW  
LEVEL CONVERGENT SIGNAL IN SHORT TERM GUIDANCE, THERMODYNAMICS  
SUPPORT CONVECTIVE DEVELOPMENT WITH MOIST LOW-LEVELS IN AN  
UNCAPPED ENVIRONMENT THAT WILL BECOME INCREASINGLY UNSTABLE AS  
HEATING COMMENCES. WEAK FORCING FOR ASCENT MAY BE PRESENT ON THE  
NORTHERN EDGE OF AN UPPER LOW THAT WILL DRIFT SLOWLY EAST-NORTHEAST  
INTO CENTRAL TEXAS TOMORROW AFTERNOON. HIGHEST PRECIPITATION  
PROBABILITIES WERE ALIGNED WITH MODEL PLACEMENT OF STRONGEST PRESSURE  
GRADIENT ON 1.5 PVU SURFACE, BUT TRENDS WILL BE MONITORED AND  
ADJUSTMENTS TO THIS WILL BE MADE BASED ON OBSERVATIONAL DATA THROUGH  
THE DAY.  
 
RELATIVELY WEAK MID LEVEL LAPSE RATES SHOULD LIMIT MLCAPE TO  
AROUND 1,000-1,500 J/KG THIS AFTERNOON. WINDS ALOFT CONTINUE TO BE  
WEAK WITH 0-6 KM SHEAR AROUND OR UNDER 10 KNOTS AND CLOUD LAYER  
SHEAR AROUND 15 KNOTS AT BEST. THIS IS INSUFFICIENT  
FOR SUSTAINED/ORGANIZED UPDRAFTS AND WILL LIMIT THE SEVERE POTENTIAL  
TO ISOLATED BRIEF MARGINALLY SEVERE GUSTS. SLOW STORM MOVEMENT AND  
DEEP MOISTURE (MODEL PROJECTED PWAT AROUND OR SLIGHTLY OVER 1.5")  
WILL SUPPORT LOCALLY HEAVY RAINFALL AMOUNTS. WE SAW THIS TODAY WITH  
1.68 INCHES MEASURED AT THE EVA MESOSNET.  
 
SIMILAR THERMODYNAMICS MONDAY ALONG WITH SUBTLE HEIGHT FALLS BY  
EVENING FROM DEEPENING GREAT LAKES TROUGH SHOULD BE ENOUGH TO JUSTIFY  
HIGH CHANCE PROBABILITIES ONCE AGAIN. THERE IS SOME QUESTIONON  
PLACEMENT AND DEGREE OF AMPLICATION OF WESTERN OF SOUTHWESTERN CONUS  
TROUGH THOUGH AND THIS COULD ULTIMATELY BE FURTHER EAST/STRONGER  
LEADING TO REDUCED CHANCES. THE RIDGE SHOULD BUILD IN SUBSTANTIALLY  
ENOUGH TUESDAY TO LIMIT CHANCES TO SLIGHT/LOW ACROSS MOST OF THE  
AREA.  
 
MID-UPPER LEVEL FLOW WILL INCREASE AND VEER TO NORTHWESTERLY BY  
LATE TUESDAY. THIS PERSISTS THROUGH AT LEAST THE END OF THE WEEK  
WITH PERIODIC SHORTWAVES EMBEDDED WITHIN THE FLOW AFFECTING THE  
AREA. WHEN AND EXACTLY WHERE THESE ENHANCE CONVECTIVE DEVELOPMENT  
IS UNCERTAIN, ALTHOUGH MODELS ARE IN AGREEMENT ON A FAIRLY  
PRONOUNCED SHORTWAVE PASSING BY WEDNESDAY, POSSIBLY RESULTING IN AN  
MCS THAT MAY AFFECT THE NORTHEASTERN PORTION OF THE FORECAST AREA  
WEDNESDAY EVENING. WE HAVE CONFINED HIGHEST PROBABILITIES THEN TO  
THOSE AREAS.  
 
LATE THURSDAY THROUGH FRIDAY EVENING MAY BE WHEN THE HIGHEST  
CHANCES FOR PRECIPITATION EXIST. MODELS SHIFT OR REORIENT THE UPPER  
RIDGE FURTHER SOUTH WHICH RESULTS IN WEST-NORTHWESTERLY FLOW OVER  
OUR AREA AND A SERIES OF PERTURBATIONS PASS THROUGH. THESE ALONG  
WITH MOUNTAIN DIURNAL CONVECTION AND OVERALL FASTER MID LEVEL  
FLOW SUGGEST AN ORGANIZED THUNDERSTORM COMPLEX OR TWO MAY PASS  
THROUGH DURING THAT PERIOD, ESPECIALLY ACROSS THE NORTHERN HALF OF  
THE AREA. A WEAK COLD FRONT MAY MOVE SOUTHWARD INTO THE AREA THEN  
TOO BRINGING SLIGHTLY COOLER TEMPERATURES LATE IN THE WEEK AND INTO  
THE WEEKEND.  
 
BRB  
 

 
   
AMA WATCHES/WARNINGS/ADVISORIES
 
 
TX...NONE.  
OK...NONE.  
 

 
 

 
 
15/17  
 
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