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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
645 AM CDT TUE APR 21 2015

.DISCUSSION...
AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW.

&&

.AVIATION...
THINK VFR CONDITIONS WILL MAINLY PREVAIL.

ISO-SCT -SHRA WILL BE EAST OF KPNC-KOKC-KDUC BY 15Z.

ISO-SCT TSRA WILL LIKELY DEVELOP OVER WESTERN OKLAHOMA AFTER
06Z...THUS ADDED VCTS AT TAF SITES IN THESE AREAS. BRIEF VARIABLE
GUSTY WINDS...GS...AND MVFR OR LOWER CONDITIONS MAY BE POSSIBLE
WITH TSRA.

FAIRLY LIGHT SURFACE WINDS WILL SHIFT TO THE NORTH TO NORTHEAST
AT MANY SITES AFTER 06Z.

MVFR/IFR CONDITIONS MAY FORM SOUTH OF KWWR-KOUN AFTER 06Z. DID NOT
MENTION THINKING THESE LOWER CONDITIONS WILL NOT FORM IN THESE
LOCATIONS BEFORE 12Z WEDNESDAY.

MBS

&&

.PREV DISCUSSION... /ISSUED 358 AM CDT TUE APR 21 2015/ 

DISCUSSION...
THE FORECAST CHALLENGE OF THE DAY IS SEVERE WEATHER POTENTIAL
THROUGH FRIDAY.

THIS MORNING...ISOLATED TO SCATTERED SHOWERS FROM WEAK MID LEVEL
MOISTURE CONVERGENCE/ISENTROPIC LIFT WILL CONTINUE MAINLY ACROSS
SOUTHERN OKLAHOMA. CANNOT RULE OUT A RUMBLE OF THUNDER...BUT NO
SEVERE WEATHER WILL OCCUR. ANY RAINFALL WILL BE LIGHT AND UNDER
0.10 INCH.

THIS AFTERNOON...SKIES WILL CLEAR AND ALLOW FOR GOOD DAYTIME
HEATING. THINK CAPPING WILL BE TOO STRONG FOR STORM
DEVELOPMENT...EXCEPT PERHAPS NEAR A WEAK SURFACE BOUNDARY OVER
SOUTHERN KANSAS ACCORDING TO THE LATEST HRRR RUN. KEPT 20 PERCENT
CHANCE FOR STORMS NEAR THE KANSAS AND OKLAHOMA STATE LINE EAST OF
ALVA AFTER 4 PM. IF THESE STORMS FORM...THEY COULD BE SEVERE WITH
SOME LARGE HAIL UP TO GOLF BALLS AND DAMAGING WINDS UP TO 60 MPH
AS STRONG 0-6 KM SHEAR AND MUCAPE AROUND 1000 J/KG SUPPORT SOME
SEVERE POTENTIAL.

TONIGHT...WILL MONITOR FOR ADDITIONAL STORM FORMATION...MAINLY
AFTER MIDNIGHT ACROSS WESTERN OKLAHOMA ON THE NOSE OF THE LOW
LEVEL JET. LATEST MODELS HAVE BEEN TRENDING SLOWER WITH STORM
DEVELOPMENT. WITH INCREASING ELEVATED INSTABILITY AND STRONG 0-6
KM SHEAR...STORMS WILL BEGIN WITH LARGE HAIL UP TO GOLF BALLS AS
THE MAIN HAZARD...BUT MAY TRANSITION TO SOME WIND AND HAIL AS
STORMS MAY FORM INTO A CLUSTER OR LINE THEN MOVE EAST OR SOUTHEAST
TOWARDS DAYBREAK...MAINLY AFFECTING WESTERN OKLAHOMA. A FEW
ADDITIONAL SEVERE STORMS MAY BE NEAR A DEVELOPING COLD FRONT IN
NORTHERN OKLAHOMA. WIDESPREAD SEVERE SEEMS UNLIKELY TONIGHT.

WEDNESDAY...AN ACTIVE DAY OF SEVERE WEATHER MAY OCCUR...
ESPECIALLY ACROSS THE SOUTHERN HALF OF OKLAHOMA AND NORTH TEXAS. A
COMPLEX OF STORMS MAY OCCUR DURING THE MORNING HOURS AND MOVE EAST
OR SOUTHEAST BRINGING SOME WIND AND HAIL REPORTS AS WELL AS
LOCALLY HEAVY RAINFALL. REDEVELOPMENT MAY OCCUR DURING THE
AFTERNOON AND EVENING NEAR THE OUTFLOW BOUNDARY WHICH MAY BE NEAR
THE RED RIVER. THERE IS SOME POTENTIAL FOR SIGNFICANT SEVERE
INCLUDING GIANT HAIL GREATER THAN GOLF BALLS...DAMAGING WINDS OVER
70 MPH...AND PERHAPS TORNADOES IF LOW LEVEL SHEAR IS STRONG
ENOUGH...BUT CONFIDENCE OF THIS OCCURRING REMAINS LOW AS NOT SURE
HOW THE CONVECTION DURING THE MORNING AFFECTS THE ENVIRONMENT
DURING THE AFTERNOON AND EVENING HOURS. IT APPEARS NORTHERN
OKLAHOMA MAY NOT RECEIVE MANY STORMS OR SEVERE WEATHER WHERE THE
AIR WILL BE COOLER AND MORE STABLE.

WEDNESDAY NIGHT INTO THURSDAY...A FEW SEVERE STORMS MAY LINGER
OVER FAR SOUTHERN OKLAHOMA AND NORTH TEXAS WITH LARGE HAIL...
DAMAGING WINDS...AND HEAVY RAINFALL. HOWEVER...MOST STORMS MAY BE
SOUTH OF THE RED RIVER...LEAVING BEHIND COOL AND STABLE CONDITIONS
ACROSS OKLAHOMA. CONFIDENCE OF SEVERE STORMS DURING THIS TIME
FRAME REMAINS LOW AS NOT SURE HOW WEDNESDAY/S CONVECTION CHANGES
THE AIRMASS ACROSS THE REGION. WENT BELOW MODEL GUIDANCE
TEMPERATURES.

FRIDAY...ANOTHER ROUND OF SEVERE THUNDERSTORMS...POSSIBLY WITH
SIGNIFICANT SEVERE...MAY RETURN TO THE AREA. VERY STRONG
SHEAR/WINDS WOULD SUPPORT FAST MOVING SUPERCELLS. HOWEVER...
MOISTURE AND INSTABILITY REMAIN QUESTIONABLE...ESPECIALLY AS
CONVECTION OVER TEXAS MAY LIMIT THE NORTHWARD PROGRESS OF RICHEST
MOISTURE AND HIGHEST INSTABILITY. REGARDLESS...WILL CLOSELY
MONITOR. ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS ALONG WITH
WINDY AND HOT WEATHER MAY FORM BEHIND A DRYLINE.

SATURDAY THROUGH MONDAY...A QUIETER WEATHER PATTERN IS FORECAST
WITH NEAR AVERAGE TEMPERATURES.

MBS

&&

.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK  77  54  69  54 /  20  20  50  40 
HOBART OK         77  54  73  54 /  10  40  70  40 
WICHITA FALLS TX  78  57  76  57 /  10  20  40  40 
GAGE OK           79  49  66  46 /  10  40  40  30 
PONCA CITY OK     78  49  64  47 /  20  30  30  30 
DURANT OK         76  57  75  60 /  30  10  60  40 

&&

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

$$

25/17/17

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