800  
FXUS64 KOUN 300515  
AFDOUN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORMAN OK  
1215 AM CDT THU MAR 30 2017  
   
DISCUSSION
 
 
THE MARCH 30-31, 2017 06 UTC TAF DISCUSSION FOLLOWS:  
 

 
   
AVIATION
 
 
CEILING RESTRICTIONS WITH MVFR STRATUS WILL CONTINUE TO PERSIST  
NORTH AND EAST OF A LINE FROM NEAR KGAG/KWWR TO KCSM TO KOKC/KOUN.  
SOME CEILING RESTRICTIONS MAY MAKE IT AS FAR SOUTH OF A LINE FROM  
KHBR TO KLAW, BUT CONFIDENCE IS TOO LOW TO INCLUDE IN TAFS. A FEW  
SHOWERS WILL BE POSSIBLE ACROSS NORTH CENTRAL OKLAHOMA UNTIL  
APPROXIMATELY 09Z.  
 
FLIGHT CONDITIONS ARE EXPECTED TO TRANSITION TOWARD VFR BY  
TOMORROW AFTERNOON EXCEPT ACROSS NORTHERN OKLAHOMA WHERE WRAP-  
AROUND CLOUDS ARE EXPECTED TO PERSIST UNTIL TOMORROW EVENING.  
 
OTHERWISE, WEST-NORTHWEST WINDS WILL SHIFT TO THE NORTH, THEN THE  
NORTHEAST AND THEN EAST TOWARD THE END OF THE TAF PERIOD.  
 
MAHALE  
 

 
   
PREV DISCUSSION
 
/ISSUED 936 PM CDT WED MAR 29 2017/  
 
UPDATE...  
MODIFICATION TO POPS, WINDS, TEMPS FOR 1ST PERIOD.  
 
DISCUSSION...  
LOWERED POPS MOST OF THE REGION WITH LOW POPS CONTINUING ACROSS  
FAR NORTHERN OKLAHOMA TONIGHT INTO TOMORROW FOR POSSIBILITY OF  
LIGHT WRAP AROUND PRECIP. WILL KEEP THE STRONGER NORTHWESTERLY  
WINDS GOING FOR LONGER TONIGHT GIVEN LATEST OBSERVATION TRENDS  
AND SHORT TERM MODEL OUTPUT. TEMPS WERE ONLY MODIFIED SLIGHTLY TO  
ALIGN WITH OBSERVATIONAL TRENDS.  
 
PREV DISCUSSION... /ISSUED 650 PM CDT WED MAR 29 2017/  
 
DISCUSSION...  
THE MARCH 30-31, 2017 00 UTC TAF DISCUSSION FOLLOWS:  
 
AVIATION...  
CEILING RESTRICTIONS WITH MVFR STRATUS WILL CONTINUE TO PERSIST  
ACROSS THE NORTHERN HALF OF OKLAHOMA AS WRAP-AROUND CLOUDS ROTATE  
AROUND A CYCLONE. THESE LOWERED CEILINGS MAY MAKE IT AS FAR SOUTH  
AS KOKC/KOUN AND KHBR LATER TONIGHT; HOWEVER, CURRENTLY EXPECT VFR  
CONDITIONS FARTHER SOUTH. IN ADDITION, SOME SHOWERS MAY IMPACT  
KPNC THIS EVENING; HOWEVER, CONFIDENCE IS TOO LOW TO INCLUDE IN  
TAFS.  
 
OTHERWISE, WEST-NORTHWEST WINDS ARE EXPECTED WEAKEN AFTER SUNSET  
BEFORE INCREASING BY TOMORROW MORNING. FLIGHT CONDITIONS ARE  
EXPECTED TO TRANSITION TOWARD VFR BY TOMORROW AFTERNOON EXCEPT  
ACROSS NORTHERN OKLAHOMA WHERE WRAP-AROUND CLOUDS ARE EXPECTED TO  
PERSIST THROUGH THE END OF THE TAF PERIOD  
 
MAHALE  
 
PREV DISCUSSION... /ISSUED 323 PM CDT WED MAR 29 2017/  
 
DISCUSSION...  
PRIMARY FORECAST FOCUS IS ON CONTINUED RAIN CHANCES TODAY AND A  
RETURN CHANCE FOR THUNDERSTORMS, POSSIBLY SEVERE, ON SATURDAY.  
 
JUST A NOTE, QUITE A SIGNIFICANT AND FASCINATING HEAVY RAIN AND  
FLOODING EVENT LAST NIGHT FOR WESTERN NORTH TEXAS INTO  
SOUTHWESTERN OKLAHOMA AND CENTRAL OKLAHOMA. THE HEAVIEST SWATH OF  
RAIN FELL, GENERALLY, ALONG AND NEAR THE I- 44 CORRIDOR. I  
HAVEN'T SEEN A STALLED/BACKBUILDING MCS QUITE LIKE THAT SINCE  
PERHAPS MAY 31, 2013 OVER THE OKC METRO. LOOKING BACK AT THE  
INGREDIENTS, BRIEFLY THIS MORNING, HOW THE EVENT UNFOLDED FITS  
QUITE WELL WITH CORFIDI'S WORK WITH MCS MAINTENANCE AND MOTION,  
1996, 1998, AND 2003. AS THE LOW LEVELS BEGAN TO SATURATE, IT  
FOSTERED AN UNFAVORABLE ENVIRONMENT FOR THE DEVELOPMENT OF  
CONVECTIVE DOWNDRAFTS, OVERALL. THIS WOULD SUGGEST A LACK OF A  
DECENT MESOHIGH FORMATION, RESULTING IN LOW FORWARD PROPAGATION  
AS NEW DEVELOPMENT WOULD NEARLY OFFSET ANY PROPAGATION. THIS WAS A  
FASCINATING CASE, AND WILL BE LOOKED AT MUCH CLOSER, AS THERE ARE  
SEVERAL DETAILS I'M SURE I GLOSSED OVER HERE.  
 
THIS AFTERNOON, SCATTERED SHOWERS AND LIGHT RAIN CONTINUE TO DEVELOP  
ACROSS PORTIONS OF WESTERN OKLAHOMA INTO THE PANHANDLES AND WESTERN  
KANSAS. GOES-16 FIVE MINUTE WATER VAPOR IMAGERY PAINTS, QUITE  
LITERALLY, A BEAUTIFUL PICTURE OF THE EVOLVING PROGRESSION OF THE  
UPPER LOW. OF NOTE ON CHANNEL 10, LOW LEVEL WATER VAPOR, HAS BEEN  
THE ADVANCING DRY SLOT FROM EAST OF THE BIG BEND INTO EASTERN  
OKLAHOMA. OKLAHOMA MESONET SITES ARE PICKING UP ON THIS TREND, WITH  
RECENT DEW POINTS IN THE UPPER 40S CROPPING UP ALONG THE I-35  
CORRIDOR IN FAR SOUTHERN OKLAHOMA. WITH THIS IN MIND, CONFINED THE  
BEST CHANCES FOR RAIN TO WESTERN AND NORTHERN OKLAHOMA, WHERE THE  
BETTER ISENTROPIC ASCENT WILL RESIDE AS THE UPPER LOW LIFTS  
EAST/NORTHEAST THROUGH THE EVENING AND OVERNIGHT.  
 
INTO TOMORROW, THE 500MB TROUGH WILL CONTINUE TO EXIT TO THE EAST,  
FINALLY SLIDING ALONG THE OZARK PLATEAU BY MIDDAY. LOW RAIN CHANCES  
WILL LINGER ON THE BACKSIDE OF THE EXITING TROUGH, ACROSS NORTH  
CENTRAL OKLAHOMA, THROUGH MIDDAY. OVERALL, STILL EXPECT MOSTLY  
CLOUDY CONDITIONS FOR MUCH OF OKLAHOMA, AS LOW CLOUDS WILL TRAIL THE  
EXITING TROUGH. DRY CONDITIONS CAN BE EXPECT THROUGH THE REMAINDER  
OF THE DAY, WITH CLEARING IN THE AFTERNOON HELPING TEMPERATURES PUSH  
BACK INTO THE 70S ACROSS WESTERN NORTH TEXAS. UPPER LEVEL RIDGING  
WILL INCREASE INTO FRIDAY ACROSS THE SOUTHERN PLAINS. A WEAK SURFACE  
TROUGH WILL POSITION ITSELF WEST-EAST ACROSS THE REGION, WITH WARM  
SOUTHERLY FLOW RESULTING IN HIGHS IN THE UPPER 70S AND 80S ACROSS  
TEXOMA.  
 
FOR SATURDAY, CURRENT WATER VAPOR SHOWS A DEVELOPING, OFF SHORE,  
PACIFIC NORTHWEST LOW. MID-RANGE GUIDANCE REMAINS IN RATHER DECENT  
AGREEMENT INTO THE WEEKEND. EXPECT THE CURRENT PACIFIC LOW TO DIG  
ACROSS THE CASCADES, INTO THE INTERMOUNTAIN WEST BY FRIDAY MORNING.  
THE 500MB TROUGH AXIS WILL PIVOT OVER THE FOUR CORNERS OPENING UP  
THE SOUTHERN PLAINS TO SUFFICIENT RETURN FLOW FROM THE GULF THROUGH  
SATURDAY MORNING. BY DAYBREAK, EXPECT A DEFINED DRY LINE TO BE  
SHAPING UP ALONG THE LLANO ESTACADO, WITH A POTENTIAL FOR SOME  
MORNING CONVECTION ACROSS NORTHWESTERN OKLAHOMA, FOCUSED ALONG A  
PSEUDO WARM FRONT EARLY. THROUGH MIDDAY, THE DRY LINE WILL ADVANCE  
EASTWARD INTO WESTERN OKLAHOMA AND WESTERN NORTH TEXAS. MODEST  
INSTABILITY, 800 TO 1500 J/KG AND SHEAR WILL SUPPORT SCATTERED  
THUNDERSTORMS, CAPABLE OF SEVERE HAIL AND WIND. INITIALLY ISOLATED  
DEVELOPMENT, WILL MERGE INTO ONE OR MORE COMPLEXES THROUGH THE  
EVENING, AS STORMS MOVE ACROSS CENTRAL INTO EASTERN OKLAHOMA INTO  
EARLY SUNDAY.  
 
SCATTERED SHOWERS AND LINGERING THUNDER WILL HANG AROUND ON SUNDAY,  
AS THE PARENT, UPPER TROUGH BEGINS TO SWING AND DEEPEN TOWARDS THE  
RIO GRANDE VALLEY. THUNDERSTORMS WILL REMAIN POSSIBLE THROUGH MONDAY  
MORNING, ACROSS PRIMARILY SOUTHERN INTO EASTERN OKLAHOMA, AS THE  
UPPER TROUGH FINALLY LIFTS EAST BY MONDAY NIGHT.  
 
KURTZ  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
OKLAHOMA CITY OK 43 60 43 72 / 10 10 0 0  
HOBART OK 42 67 43 74 / 10 10 0 0  
WICHITA FALLS TX 46 71 47 83 / 30 10 0 0  
GAGE OK 38 63 39 66 / 20 10 0 0  
PONCA CITY OK 43 51 39 66 / 30 30 10 0  
DURANT OK 47 65 46 80 / 10 10 0 0  
 

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

 
 

 
 
11/10/10  
 
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