193  
FXUS64 KAMA 141101  
AFDAMA  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE AMARILLO TX  
601 AM CDT FRI MAY 14 2021  
   
AVIATION
 
 
FOR THE 12Z TAFS:  
 
VFR CONDITIONS ARE EXPECTED AT THE TERMINALS THROUGHOUT THE VALID  
TAF PERIOD. THE MAIN CONCERN TODAY WILL BE THE THUNDERSTORM  
POTENTIAL LATE THIS AFTERNOON AND EVENING WHICH MAY END UP  
IMPACTING ALL THREE TERMINALS. IF THUNDERSTORMS IMPACT THE  
TERMINALS, THERE COULD BE A CHANGE TO MVFR AT THAT POINT WITH ANY  
INTENSE RAINFALL IMPACTING VISIBILITIES. OTHERWISE, STORMS SHOULD  
RACE THROUGH PRETTY QUICK, SO IF THE TERMINALS ARE IMPACTED, IT  
WILL ONLY BE FOR A COUPLE HOURS MORE THAN LIKELY.  
 
GUERRERO  
 

 
   
PREV DISCUSSION
 
/ISSUED 347 AM CDT FRI MAY 14 2021/  
 
SHORT TERM (TODAY THROUGH TOMORROW NIGHT)...  
 
WE BEGIN OUR ACTIVE WEATHER PATTERN ACROSS THE PANHANDLES TODAY.  
BOTH TODAY AND TOMORROW WILL HAVE THE POTENTIAL FOR SEVERE  
THUNDERSTORMS ACROSS THE AREA. WE HAVE SOME LIMITING FACTORS WHICH  
WE WILL DISCUSS, BUT OVERALL CONFIDENCE IS MODERATE (SCALE OF  
LOW, MODERATE, AND HIGH) FOR SEVERE WEATHER TO DEVELOP OVER  
PORTIONS OF THE FORECAST AREA. THE MAIN THREATS WILL BE WIND AND  
HAIL.  
 
AT A GLANCE SEVERE WEATHER TIMING/THREATS:  
 
* TODAY/FRIDAY: 4PM TO MIDNIGHT  
- ENTERING THE WESTERN PANHANDLES AND QUICKLY PUSHING EAST  
- HAIL: AROUND QUARTER SIZE  
- WIND: 60 - 70 MPH  
- TORNADO: UNLIKELY  
 
* TOMORROW/SATURDAY: 3PM THROUGH THE OVERNIGHT PERIOD  
- ANOTHER WEST TO EAST PROGRESSION  
- HAIL: UP TO GOLF BALL SIZE  
- WIND: 60 - 75 MPH  
- TORNADO: UNLIKELY  
 
FURTHER DETAILS:  
 
LATER TODAY, AN H5 LOW WILL BEGIN TO MAKES IT TREK SOUTHWARD  
ACROSS CALIFORNIA, AND IT SHOULD EVENTUALLY BECOME A CLOSED LOW  
BY LATE THIS EVENING. DOWNSTREAM, AHEAD OF THE MAIN DISTURBANCE, A  
SHORTWAVE WILL KICK OUT OVER THE PANHANDLES LATE THIS  
AFTERNOON/EVENING. TO OUR WEST, OVER THE HIGHER TERRAIN,  
CONVECTIVE TEMPERATURES MAY ALLOW FOR THUNDERSTORMS TO INITIATE  
OVER EASTERN NEW MEXICO BY MID AFTERNOON, AND THESE STORMS SHOULD  
GET GOING EASTWARD AS THAT SHORTWAVE MAKES ITS WAY TOWARDS THE  
SOUTHERN PLAINS. WE ARE LACKING RETURN FLOW TODAY, AND FORECAST  
SOUNDINGS DEPICT AN INVERTED-V PROFILE TODAY WITH SUFFICIENT HIGH  
BASED INSTABILITY. LOW/MID LEVEL FLOW IS RATHER WEAK, SO  
SHEAR/HELICITY PARAMETERS ARE ALSO WEAK. WE DO HAVE A VEERING WIND  
PROFILE IN THE LOW/MID LEVELS, BUT THE SPEED PARAMETER HERE IS  
RATHER WEAK. IN OTHER WORDS, THE LOW LEVEL WIND PATTERN IS SO  
WEAK, AND THE LCL HEIGHTS ARE GOING TO BE SO HIGH, IT'S GOING TO  
BE DIFFICULT TO SUPPORT A THREAT FOR TORNADOES WITHOUT SOME  
SERIOUS MESOSCALE MODIFICATIONS TO THE ATMOSPHERE. MLCAPE AROUND  
500-1500 J/KG WILL BE PRESENT TODAY ALONG WITH DOWNDRAFT CAPE  
AROUND 500-1200 J/KG. THIS COULD VERY WELL LEAD TO DAMAGING WIND  
GUSTS AND SEVER HAIL. HODOGRAPHS ARE SMALL AND RESEMBLE A  
MULTICELL/SPLIT/PULSE TYPE OF STORM MODE TODAY. THIS COULD LEAD  
TO SOME NUISANCE ON THE WARNING DESK FOR THE RADAR OPERATOR AS  
STORMS PULSE AND STRUGGLE TO MAINTAIN AN UPDRAFT AND/OR COLLAPSE.  
HOWEVER, IT SHOULD GET EASIER FOR WARNINGS AS STORMS MAY BECOME  
MORE COLD POOL DOMINANT AND LINEAR IN NATURE AS THEY PROGRESS EAST  
ACROSS THE PANHANDLES IN THE EVENING HOURS. TODAY, LEANING MORE  
ON THE WIND THREAT GIVEN HOW QUICKLY STORMS COULD BECOME LINEAR  
AND THE AMOUNT OF DOWNDRAFT CAPE WITH THE INVERTED-V PROFILES.  
 
MOVING AHEAD TO TOMORROW, A VERY SIMILAR SETUP REGARDING THE UPPER  
LEVELS AS ANOTHER SHORTWAVE KICKS OUT AHEAD OF THE MAIN H5 LOW  
(NOW ENTERING SOCAL). OVERALL, A LOT OF THE PARAMETERS ARE SIMILAR  
TO FRIDAY, BUT WE WILL SEE HIGHER MLCAPE VALUES. THEREFORE, THE  
THOUGHT IS WE WILL SEE HIGHER THREAT LEVELS OF HAIL, BUT AGAIN THE  
SHEAR PARAMETERS ARE NOT THE MOST IDEAL FOR UPDRAFT MAINTENANCE.  
MLCAPE AROUND 2000 J/KG WILL BE PRESENT WITH DOWNDRAFT CAPE  
SIMILAR TO FRIDAY. THAT AMOUNT OF CAPE MAY BE ENOUGH TO OVERCOME  
SOME OF THE FEEBLE SHEAR PARAMETERS, SO HAIL UP TO GOLF BALL SIZE  
MAY BECOME EVIDENT. 700MB THETA-E VALUES ARE HIGHER TOMORROW THAN  
FRIDAY, SO THUNDERSTORM COVERAGE MAY BE GREATER ACROSS THE  
PANHANDLES, BUT AGAIN IT LOOKS LIKE UNORGANIZED  
MULTICELL/SPLIT/PULSE TYPE STORM MODE BASED ON HODOGRAPHS. MEAN  
FLOW AROUND 500MB IS VERY WEAK, SO STORMS ARE LIKELY GOING TO BE  
SLOW MOVERS, AND THIS COULD LEAD TO A HIGHER CHANCE FOR DOWNBURST  
AS UPDRAFTS COLLAPSE. WIND THREAT LOOKS TO BE HIGHER TODAY AS  
WELL COMPARED TO FRIDAY. WITH THAT SAID, IT MAY BE ANOTHER  
DIFFICULT WARNING DAY AS THE PULSE NATURE OF THE STORMS MAY BECOME  
A NUISANCE. IN FACT, ITS LIKELY GOING TO BE MORE OF A NUISANCE  
THAN FRIDAY.  
 
GUERRERO  
 
LONG TERM...SUNDAY THROUGH THURSDAY...  
 
SYNOPSIS: ACTIVE WEATHER WITH POTENTIAL FOR SEVERE STORMS WILL  
CONTINUE THROUGH AT LEAST MONDAY, WITH STORM CHANCES CONTINUING  
THROUGH THURSDAY. DETAILS COULD CHANGE IN TERMS OF STORM SEVERITY,  
COVERAGE, AND TIMING BASED ON SEVERAL FACTORS (EXPLAINED MORE  
BELOW). OTHERWISE, EXPECT TEMPERATURES NEAR AVERAGE ON SUNDAY TO  
SLIGHTLY BELOW AVERAGE FOR MOST OF NEXT WEEK DEPENDING ON  
PLACEMENT OF A COLD FRONT AND EXTENT OF LOW CLOUDS.  
 
DETAILS: AN UPPER LEVEL CLOSED LOW IS EXPECTED TO TREK ACROSS THE  
SOUTHERN TIP OF NV ON SUNDAY, ENDING UP OVER NORTHERN AZ BY MONDAY  
AFTERNOON. THE LATEST DETERMINISTIC MODELS AND ENSEMBLES ARE IN  
DECENT AGREEMENT WITH THE UPPER SYSTEM THROUGH THIS TIME, BUT  
START TO DIVERGE FROM ONE ANOTHER GOING INTO TUESDAY AND  
WEDNESDAY. MODELS HAVE TRENDED A BIT SLOWER, WITH THE SYSTEM  
BECOMING MORE ELONGATED AND NEGATIVE TILT AS IT MOVES OUT OVER  
THE SOUTHERN GREAT PLAINS TUESDAY INTO WEDNESDAY. GIVEN THIS, THE  
PANHANDLES LOOK TO REMAIN IN RETURN FLOW WITH AT LEAST SOME FORM  
OF DIFFUSE DRYLINE / SFC TROUGH MIXING EAST EACH AFTERNOON UNTIL  
THIS SYSTEM FINALLY TRANSLATES ACROSS THE AREA BY MID WEEK. A COLD  
FRONT WILL ALSO BE IN PLAY - MORE SO ON MONDAY AND TUESDAY AS A  
MORE PRONOUNCED SURFACE LOW ATTEMPTS TO DEVELOP IN EASTERN NM.  
 
THE UNFORTUNATE TRUTH IS THAT THE MODELS ARE GOING TO STRUGGLE  
WITH THE PLACEMENT OF SURFACE FEATURES AND RESULTING CONVECTION  
SUNDAY AND MONDAY, ESPECIALLY CONSIDERING HOW SLOW THE UPPER  
SYSTEM IS ADVANCING EAST. EXCEPT FOR SOME LIMITED DYNAMIC LIFT  
ASSOCIATED WITH MINOR LEAD SHORTWAVES SUNDAY AND MONDAY, LARGE  
SCALE LIFT WILL MAINLY STAY WEST OF THE PANHANDLES UNTIL AT LEAST  
MONDAY NIGHT IF NOT TUESDAY. 500MB HEIGHTS ACTUALLY INCREASE SOME  
ON SUNDAY IN PRESENCE OF WEAK RIDGING PRIOR TO THE ARRIVAL OF A  
LEAD SHORTWAVE. CONVECTIVE INITIATION IS LIKELY TO OCCUR SUNDAY  
AFTERNOON AND MONDAY AFTERNOON ALONG THE DRYLINE AS CONVECTIVE  
TEMPERATURES ARE REACHED. A COLD FRONT MAY ALSO HELP TRIGGER  
STORMS, BUT MODELS DIFFER ON HOW FAR SOUTH THE FRONT WILL BE  
SUNDAY AND ALSO WHERE THE BEST DRYLINE CONVERGENCE WILL BE (OLD  
OUTFLOW BOUNDARIES AND RECOVERY ISSUES MAY ALSO PLAY HAVOC WITH  
THE FORECAST - AS MODELS DON'T RESOLVE THESE THINGS WELL). ANY  
STORMS THAT DO FORM WILL BE IN ENVIRONMENT WITH UPPER 50S TO LOW  
60S SFC DEW POINTS, MLCAPE AROUND 1000 TO 2000 J/KG, AND STEEP  
LAPSE RATES. EFFECTIVE SHEAR REMAINS PRETTY LOW (20 TO 30 KNOTS)  
AS THE BETTER WIND FIELDS STAY WEST OF THE PANHANDLES UNTIL LATE  
MONDAY. OVERALL, THE MAIN THREAT WILL BE LARGE HAIL (GOLF BALL OR  
EVEN SLIGHTLY LARGER GIVEN COOL TEMPS ALOFT) AND DAMAGING WINDS  
GIVEN HIGH BASES AND LARGE DCAPE VALUES. THE TORNADO THREAT WILL  
REMAIN LOW GIVEN HIGH LCLS AND LACKING LOW LEVEL SHEAR, BUT CAN'T  
COMPLETELY BE RULED OUT GIVEN BOUNDARIES IN PLAY.  
 
RIGHT NOW, DETERMINISTIC MODELS DO SHIFT THE FRONT THROUGH THE  
PANHANDLES BY MONDAY AFTERNOON, WHICH SUGGEST LIFT WILL BE MORE  
IN THE FORM OF UPSLOPE FLOW OVER THE HIGHER TERRAIN. THIS IS ALSO  
WHEN BETTER LARGE SCALE LIFT APPROACHES WITH PVA AND HEIGHT FALLS  
OCCURRING LATE MONDAY THROUGH TUESDAY. SO EVEN IF THE PANHANDLES  
IS BEHIND THE COLD FRONT MONDAY INTO TUESDAY, SHOWERS AND ELEVATED  
STORM CHANCES LOOK REALLY GOOD, AND SEVERE STORMS MAY BE MORE  
LIMITED TO HAIL IF ENOUGH ELEVATED INSTABILITY CAN MATERIALIZE IN  
A BETTER SHEAR ENVIRONMENT. IF FOR SOME REASON THE COLD FRONT  
HANGS UP TO THE NORTH, THEN BETTER ORGANIZED SURFACE BASED STORMS  
WOULD BE POSSIBLE GIVEN INCREASED DEEP LAYER SHEAR. EITHER WAY,  
ANY STORMS THAT FORM DURING THIS TIME FRAME MAY POSE A FLASH  
FLOOD THREAT OVER AREAS THAT RECEIVE HEAVY RAIN ON DAYS PRIOR.  
 
WARD  
 

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

 
 

 
 
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