Oklahoma - Forecast discussions IWIN products will be migrated to newer systems soon. Please see additional information here FXUS64 KOUN 190355 AFDOKC AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 1055 PM CDT FRI APR 18 2003 HAVE UPPED OVERNIGHT POPS TO CATEGORICAL IN A CORRIDOR THRU CENTRAL OK. CONVECTION NOW DEVELOPING OVER W AND CENTRAL TX EXPECTED TO CONTINUE DEVELOPING/INCREASING/SPREADING NE AS LLJ ENHANCES LL CONVERGENCE AND LIFT BENEATH AND AHEAD OF MID-LEVEL SHORTWAVE TROF AND POTENT UPPER JET. EXPECT CONVECTION TO EVOLVE INTO 1 OR MORE MCS CLUSTERS AND ROLL NE ACROSS AREA LATE TONIGHT. PRELIM ASSESSMENT OF SAT SEVERE POTENTIAL AFTER CONSULTING W/SPC IS MDT RISK FOR MUCH OF OK E OF RUFLY END-OKC-ADM. POTENTIAL FOR STRONG TORNADOES EXPECTED TO BE OVER RELATIVELY SMALL AREA...EXACT LOCATION UNCERTAIN DUE TO QUESTIONS ON OVERNIGHT CONVECTIVE EVOLUTION AND SUBSEQUENT MESOSCALE FEATURES. PART OF MDT AREA COULD BE UPGRADED IN A LATER UPDATE. FCSTID = 24 OKC 62 76 50 68 / 80 70 60 0 HBR 57 77 49 70 / 70 50 20 0 SPS 61 81 52 73 / 60 50 20 0 GAG 52 64 43 66 / 40 70 80 0 PNC 61 69 48 65 / 60 80 80 0 DUA 63 81 55 72 / 50 70 70 0 .OUN... OK...NONE. TX...NONE.  FXUS64 KTSA 190225 AFDTUL EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE TULSA OKLAHOMA 925 PM CDT FRI APR 18 2003 UPDATED GRIDS AND WILL BE SENDING UPDATED ZONES SHORTLY. RAISED POPS SLIGHTLY IN THE WEST TONIGHT AND HAVE HIGHEST TO LOWEST POPS FROM WEST TO EAST ACROSS THE AREA. DEW POINTS HAVE RISEN INTO THE 60S ACROSS THE WESTERN PART OF THE AREA AND SEE NO REASON WHY THEY WOULD FALL UNTIL LATER ON TOMORROW WHEN THE DRY LINE APPROACHES. THUS...UPDATED THESE GRIDS AND FRESHENED UP LOW TEMPS TO MATCH THEM. ALSO WORKED OVER THE QPF GRIDS. THE LAST FEW DAYS THE MODELS HAVE BEEN CONSISTENT ABOUT AN MCS FORMING OVER OKLAHOMA AND MOVING NORTHEAST INTO EASTERN KANSAS AND MISSOURI. THINK THIS SCENARIO IS GOOD AND THAT PERHAPS THE HEAVY RAIN THREAT MAY BE MORE THAN THE SEVERE THREAT. ...HAZARDOUS WEATHER OUTLOOK DISCUSSION... SURFACE DRYLINE THAT WAS OVER CENTRAL OK DURING THE LATE AFTERNOON HOURS HAS CONTINUED TO PULL BACK TO THE WEST DURING THE EVENING. AT 02Z DRYLINE WAS LOCATED FROM WEST OF ENID INTO FAR SOUTHWEST CORNER OF THE STATE. ONE LONE STORM DEVELOP AROUND SPS THIS EVENING...BUT HAS SINCE DISSIPATED AS IT DRIFTED AWAY FROM THE DRYLINE INTO CAPPED AMS. HOWEVER...LIFT ASSOCIATED WITH UPPER WAVE BEGINNING TO BECOME EVIDENT WITH LIGHTNING DATA SHOWING DEVELOPMENT WAY DOWN TOWARD BIG BEND AREA AT 02Z...AND ALSO TOWARD MAF/LBB. EXPECT TO SEE ADDITIONAL DEVELOPMENT FURTHER NORTH OVER THE REMAINDER OF THE EVENING INTO NORTHWEST TX AND EVENTUALLY SOUTHWEST OK AS WAVE LIFTS TOWARD THE PLAINS AND LOW LEVEL JET ALSO INTENSIFIES. WILL LIKELY SEE AN MCS DEVELOP TO OUR SOUTHWEST THAT WILL LIFT TO THE NORTHEAST ACROSS OK INTO KS DURING THE NIGHT. POTENTIAL FOR SEVERE STORMS STILL LOOKS BEST OVER THE WESTERN PART OF THE AREA AFTER MIDNIGHT. LARGE HAIL AND STRONG WINDS ARE POSSIBLE...BUT THE POTENTIAL FOR HEAVY RAIN SEEMS TO BE THE BIGGEST THREAT. .TSA... AR...NONE. OK...NONE. ABBAS  FXUS64 KOUN 182052 AFDOKC AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 352 PM CDT FRI APR 18 2003 DRYLINE IS SHARPENING UP ACROSS THE AREA CURRENTLY. THERE IS A CHANCE TO SEE CONVECTION DEVELOP ALONG THE DRYLINE LATE THIS AFTERNOON OR EARLY THIS EVENING WITH CONVERGENCE ALONG THE DRYLINE. A BETTER CHANCE OF PRECIP DEVELOPS AS A STRONGER UPPER TROF MOVES TOWARD THE AREA. LOW LEVEL MOISTURE WILL LIKELY SLOSH BACK WESTWARD AND STORMS ARE LIKELY ESPECIALLY FROM SOUTHWEST THROUGH CENTRAL AND NORTH CENTRAL SECTIONS. LINGERING SHOWERS/STORMS IN THE MORNING WILL MOVE OUT BEFORE THE NEXT WAVE APPROACHES AND REDEVELOPMENT IS LIKELY AGAIN TOMORROW ALONG VARIOUS SURFACE BOUNDARIES THAT WILL BE AROUND. THESE STORMS WILL CONTINUE INTO THE EVENING BEFORE EXITING. EASTER SUNDAY LOOKS TO BE DRY AND MILD. NO SIGNIFICANT CHANGES IN THE EXTENDED. FCSTID = 26 OKC 62 76 50 68 / 80 70 60 0 HBR 57 77 49 70 / 70 50 20 0 SPS 61 81 52 73 / 60 50 20 0 GAG 52 64 43 66 / 40 70 80 0 PNC 61 69 48 65 / 60 80 80 0 DUA 63 81 55 72 / 50 70 70 0 .OUN... OK...NONE. TX...NONE.  FXUS64 KTSA 182035 AFDTUL EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE TULSA OKLAHOMA 330 PM CDT FRI APR 18 2003 DISC... ATMOSPHERE WILL FEATURE ACTION PACKED MOTION NEXT 30 HOURS FOR CWA. PARAMETERS STARTING TO TAKE SHAPE. MAIN QUESTION IS HOW WELL ALL THE VARIABLES WILL PHASE. CURRENTLY BRISK SOUTH SFC WIND PUSHING MID 60S DEWPOINT INTO FORECAST AREA. AS UPPER LOW ARCS THROUGH SW ENERGY ROTATING THROUGH PRODUCES PRODIGIOUS UPPER VERTICAL MOTION FIELD EVIDENT 12Z SAT. UPPER LEVEL JET AND LOWER LEVEL JET CLOSE TO IN-SYNC. HIGHEST RISK TONIGHT AS DEPICTED ON LOCAL SVR GRID GRAPHIC MAINLY WEST I-44. SAT ACTION TO BE HIGHLY INFLUENCED AND DEPENDANT ON BOUNDARIES GENERATED BY THUNDER OVERNIGHT. CLOUD MAY INHIBIT DEVELOPMENT BUT ONLY FOR A TIME. HIGHEST THREAT SEVERE SAT LOOKS MORE SOUTHEAST HALF CWA. STAY TUNED. ALL SEVERE ACTION OVER BY 03Z SUN (ACCORDING TO STAR FORECASTER). PRECIP ENDS BY SUN RISE SUNDAY. NEXT H500 FEATURE PLUNGES INTO FOUR CORNERS AREA ONCE AGAIN MID WEEK FOR POSSIBLE REPEAT OF NEXT 30 HOURS. GW -------------------------------------------- TUL 62 73 51 67 / 70 70 60 10 FSM 61 75 55 71 / 50 70 60 10 MLC 63 77 54 70 / 60 60 40 10 BVO 61 72 48 65 / 70 80 60 10 FYV 60 73 53 67 / 60 70 60 10 BYV 61 71 55 66 / 50 70 60 10 MKO 62 73 52 68 / 70 70 60 10 MIO 61 67 51 64 / 70 90 70 10 F10 62 75 52 69 / 60 60 60 10 HHW 62 81 58 73 / 50 70 40 10 FORECAST ID= 21 .TSA... AR...NONE. OK...NONE.  FXUS64 KTSA 181803 AFDTUL EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE TULSA OKLAHOMA 100 PM CDT FRI APR 18 2003 ...HAZARDOUS WEATHER OUTLOOK DISCUSSION... ACTIVE WEATHER PATTERN DURING THE NEXT 24-36 HOURS WITH THE THREAT FOR SEVERE WEATHER LATE TONIGHT AND AGAIN SATURDAY EVENING. ELEVATED THUNDERSTORMS EXPECTED TO DEVELOP OVER SOUTH-CENTRAL OKLAHOMA BY LATE EVENING ON THE NOSE OF 60 KT LOW LEVEL JET. THIS ACTIVITY WILL SPREAD INTO NORTHEAST OKLAHOMA AFTER MIDNIGHT AS THE JET AXIS SETS UP OVER TH AREA. BEST CHANCE FOR SEVERE WEATHER WILL BE OVER NORTHEAST OKLAHOMA ALONG INSTABILITY AXIS WHERE COMPUTED LI'S AT 925/850 MB LEVELS ARE FORECAST TO RANGE FROM -4 TO -6 DEG/C. ALTHOUGH LARGE HAIL APPEARS TO BE THE PRIMARY THREAT...DAMAGING DOWNBURST WINDS WILL ALSO BE POSSIBLE IN THE STRONGER CELLS GIVEN STRONG SPEED SHEAR THAT WILL BE IN PLACE. WITH PW'S APPROACHING 2 INCHES BY 12Z SATURDAY...HEAVY RAINFALL/FLASH FLOODING MAY BECOME A CONCERN IN AREAS WHERE THUNDERSTORM TRAINING OCCURS. SIGNIFICANT SEVERE WEATHER EVENT APPEARS LIKELY ON SATURDAY AS STRONG UPPER VORT/SPEED MAX MOVES INTO THE CENTRAL PLAINS. CLOUD COVER WILL LIKELY DIMINISH ACROSS CENTRAL OKLAHOMA BY AFTERNOON AS ELEVATED CONVECTION SHIFTS EAST. ATMOSPHERE IS FORECAST TO QUICKLY DESTABILIZE BY LATE AFTERNOON WITH SURFACE BASED CAPES 1500-2500 J/KG. STORMS WILL LIKELY INITIATE ALONG DRY LINE BY LATE AFTERNOON ...MOVING INTO EASTERN OKLAHOMA SATURDAY EVENING. FORECASTED THERMODYNAMIC / SHEAR PROFILES SUPPORT SUPERCELL THUNDERSTORMS ...WITH HIGHEST CHANCES FOR VERY LARGE HAIL AND TORNADOES ACROSS NORTHEAST OKLAHOMA LATE SATURDAY AFTERNOON AND EVENING. FORECAST ID= 23 .TSA... AR...NONE. OK...NONE.  FXUS64 KOUN 181557 AAA AFDOKC AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 1057 AM CDT FRI APR 18 2003 ELEVATED CONVECTION HAS MOVED OUT OF AREA INTO KANSAS AND WEAKENED. MID LEVEL CLOUDS HAVE ALSO MOVED OUT OF THE AREA...WITH SOME LOW LEVEL CLOUDS PUSHING NORTH ACROSS NORTH TEXAS. EXPECT MOST OF THE AREA TO REMAIN MOSTLY SUNNY...EXCEPT ACROSS SOUTHERN AREAS WHERE HIGH CLOUDS WILL EVENTUALLY MOVE IN LATER THIS AFTERNOON. HAVE UPDATED SKY COVER TO SHOW THIS. WITH TEMPS ALREADY IN THE 70S IN MANY LOCATIONS AND MOST AREAS RECEIVING FULL SUN HAVE INCREASED HIGH TEMPS FOR THIS AFTERNOON. MADE JUST MINOR ADJUSTMENTS TO THE HOURLY GRIDS. WILL UPDATE SOON. MAXWELL ______________________________________________ 430 AM CDT FRI APR 18 2003 CCF NUMBERS ADDED... SCATTERED SHOWERS AND STORMS OVER NORTHWEST PORTIONS OF FORECAST AREA EARLY THIS MORNING EXPECTED TO CONTINUE THEIR NORTHWARD TREK. BY THIS AFTERNOON...DRY LINE WILL MOVE INTO WESTERN/CENTRAL PORTIONS OF THE FORECAST...YIELDING THE POSSIBILITY STRONG-SEVERE THUNDERSTORMS. SHEAR PROFILES AND INSTABILITY WILL SUPPORT ELEVATED SUPERCELLS...AS BOUNDARY LAYER MOISTURE WILL BE LACKING A BIT. CONCERNED ABOUT SEVERE WEATHER SATURDAY. OVERALL SCENARIO POINTS TO THE POSSIBILITY OF A SIGNIFICANT SEVERE WEATHER EPISODE. WITH STRONG TO SEVERE CONVECTION EXPECTED TONIGHT AND DURING A TIME ON SATURDAY...OUTFLOW GENERATED BOUNDARY WILL BE LURKING LATE SATURDAY...WITH STRONG DRY LINE FORECAST TO PUNCH IN FROM THE SOUTHWEST. MESOSCALE DETAILS ON SATURDAY WILL DETERMINE EXACT AREA TO BE WATCHED MOST CLOSELY. REFER TO SPC OUTLOOKS AND OUR HAZARDOUS WEATHER OUTLOOK FOR PERTINENT DETAILS. POPS WILL BE BUMPED UP EVEN MORE FOR LATE TODAY THROUGH SATURDAY NIGHT MOST AREAS. HEAVY RAINFALL EVENT POSSIBLE LATE TONIGHT AND SATURDAY WITH HIGH PW VALUES EXPECTED. WILL LET DAY SHIFT DETERMINE IF/WHERE TO ADD HEAVY RAIN WORDING IN ZONES. MANY AREAS...ESPECIALLY OVER PORTIONS OF WESTERN NORTH TEXAS AND SOUTHWEST OKLAHOMA...COULD REALLY USE HIGHER RAINFALL TOTALS. EXTENDED... NO SIG CHANGES EXPECTED...BUT WILL TWEAK POPS TOWARD MID WEEK. GFS COMING MORE IN LINE WITH ECMWF TOWARD THE MIDDLE OF NEXT WEEK. ECMWF HAS DONE A BETTER JOB OVER SOUTHERN PLAINS IN THE OUT PERIODS...SO EXPECT THIS TREND TO CONTINUE. MIDDLE OF NEXT WEEK COULD BE FAIRLY ACTIVE. FCSTID = 11 OKC 81 61 77 50 / 20 80 80 60 HBR 81 57 77 49 / 10 70 60 20 SPS 84 60 80 52 / 30 80 70 20 GAG 79 51 64 43 / 10 40 80 80 PNC 79 60 69 48 / 30 60 80 80 DUA 82 63 81 55 / 30 60 70 70 .OUN... OK...NONE. TX...NONE.  FXUS64 KTSA 181549 AFDTUL EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE TULSA OKLAHOMA 1045 AM CDT FRI APR 18 2003 WARM DAY ON TAP ACROSS ALL OF THE FA. 12Z AREA SOUNDINGS INDICATE TEMPS WILL EXCEED ADVERTISED HIGH TEMPS...SO HAVE OPTED TO BUMP THEM AT LEAST ONE CATEGORY EVERYWHERE. ELEVATED CONVECTION ACROSS KANSAS HAS WEAKENED...AND SOUTHERN EXTENT OF MID LEVEL CLOUDS THAT ARE ACROSS OKLAHOMA ARE ERODING AS WELL. WILL GO AHEAD AND REMOVE POPS FOR THE AFTERNOON AND ADJUST SKY CONDITION TO YIELD A MOSTLY SUNNY WORDING. WILL HAVE TO KEEP AN EYE ON STORM CHANCES TONIGHT...BUT CURRENT FORECAST BEYOND FIRST PERIOD LOOKS REASONABLE. FORECAST ID= 23 .TSA... AR...NONE. OK...NONE.  This data is from the IWIN (Interactive Weather Information Network)