810 FXUS63 KDDC 260759 AFDDDC *AREA FORECAST DISCUSSION* *NATIONAL WEATHER SERVICE DODGE CITY KS* *259 AM CDT THU OCT 26 2006* * DISCUSSION* DAYS 1-2... A VERY DYNAMIC AND POWERFUL STORM SYSTEM WILL AFFECT THE FIRST TWO PERIODS OF THE FORECAST WITH WIDESPREAD RAIN, THUNDERSTORMS, STRONG NORTH WINDS, AND A MIX OF SNOW PERHAPS NEAR COLORADO...ENOUGH TO KEEP THIS FCSTR QUITE BUSY THIS MORNING! PER 26/00Z UA ANALYSIS..H5 CENTER WAS WAS JUST EAST OF KSLC...AND WAS STILL DIGGING PER WV LOOP. BY 06Z...THE CENTER APPEARED TO BE JUST SW OF KGJT. THE COMPACTNESS OF THE STORM IS RATHER IMPRESSIVE PER SATELLITE...WHICH IS ALLOWING FOR INTENSE AGEOSTROPHIC MOTIONS AT ALL LEVELS OF THE TROPOSPHERE. PV FORECAST CHARTS FROM THE NAM ARE REALLY IMPRESSIVE AS WELL WITH 4 PVU CONTOUR DOWN TO 600MB PER PLAN VIEW AND CROSS SECTIONS. THIS SUGGESTS A SIGNIFICANT INTRUSION OF STRATOSPHERIC AIR...A GOOD INDICATION OF THE VIGOROUS VERTICAL MOTIONS ON TAP FOR TODAY. TRACK OF H4-6 PVU CENTERS FROM NORTHEAST NEW MEXICO THROUGH CENTRAL/NORTHERN TX PANHANDLE INTO WESTERN OK...PUTS A LARGE CHUNK OF SOUTHWEST KS IN THE "CROSSHAIRS" FOR INTENSE LIFT. 15 UB/S OF H6-7 OMEGA FROM LOW RES 80KM NAM CERTAINLY IS IMPRESSIVE. AS FAR AS THE FCST IS CONCERNED...FIRST CONCERN IS DENSE FOG THIS MORNING. DENSE FOG ADVISORY WAS ISSUED EARLIER THIS MORNING AS MOIST ADVECTION WAS WORKING WEST INTO FAR WESTERN KANSAS IN RESPONSE TO THE APPROACHING STORM. IFR/LIFR OVERCAST WILL CONTINUE PRETTY MUCH ALL DAY UNTIL RAIN GETS GOING. RAIN WILL SPREAD EAST FROM COLORADO BY LATE MORNING. NEAR H6/7 CENTER...AT NOSE OF MID LEVEL DRY INTRUSION...POTENTIAL INSTABILITY WILL BE MAXIMIZED IN THE H8-6 LAYER AND WILL TRACK ACROSS OKLA BORDER COUNTIES. BY EARLY AFTN I FORESEE THUNDERSTORM DEVELOPMENT FROM ROUGHLY LIBERAL AREA AND POINTS EAST. ELEVATED CAPE JUST NORTH OF THE SFC FRONT AROUND 400-600 J/KG (AND HIGHER NEAR KP28) WILL BE ENOUGH TO SUPPORT SMALL HAIL (PERHAPS MARGINAL SVR HAIL) GIVEN THE IMMENSE AMBIENT UPWARD MOTION. SPC SLIGHT RISK FOR SOUTHEAST CWA LOOKS GOOD FOR THIS SCENARIO. A MORE STRATIFORM RAIN IS EXPECTED OVER THE REST OF THE CWA...AND AS THE SURFACE LOW DEVELOPS OVER NORTHERN OKLAHOMA BY AFTERNOON...STRONG NORTH WINDS WILL DEVELOP OVER WESTERN CWA BY LATE AFTERNOON. 30-35 KNOT SURFACE WINDS WILL BE POSSIBLE AFTER 21Z NEAR COLORADO LINE. WILL UPDATE THE HIGH WIND WATCH WITH A "BEEFED UP" WIND ADVISORY MENTIONING GUSTS AS HIGH AS 55 MPH. THE DIURNAL TIMING DOESNT REALLY SUPPORT VERY STRONG WINDS...HOWEVER WITH PCPN ONGOING MOST OF THE NIGHT...VERTICAL MIX DOWN OF 40 TO 45 KNOT GUSTS WILL BE LIKELY. A ROGUE 50 KNOT GUST IS ALSO POSSIBLE MAINLY OUT WEST...BUT CONFIDENCE FOR HIGH WIND WARNING IS NOT HIGH ENOUGH...CERTAINLY A MUCH EASIER DECISION FOR MY WESTERN NEIGHBORS IN COLORADO WHERE 30MB AGL WINDS OFF THE NAM ARE 50-60 KNOTS. PRECIP TYPE IS EVEN A CHALLENGE NEAR COLORADO. INTERROGATION OF POINT SOUNDING FOR ELKHART SUGGEST SFC TEMPS DROPPING TO 37 OR 38F BY EARLY EVENING. IF PRECIP INTENSITY IS STRONG ENOUGH...THINK AGGREGATE SNOW CRYSTALS COULD PENETRATE THROUGH A 1500 FT AGL WARM LAYER, DROPPING SNOW LEVELS TO PERHAPS 3500-4000 FT...WILL GO WITH A RAIN/SNOW MIX IN THE GRIDS FOR THE SOUTHWESTERN MOST TWO COUNTIES. AS PRECIP INTENSITY DECREASES...THEN SNOW LEVEL WILL RISE AND ANY MIX OR ALL SNOW OUT WEST WILL CHANGE BACK TO RAIN BEFORE ENDING AROUND MIDNIGHT. WHEN ALL IS SAID AND DONE...WIDESPREAD THREE QUARTERS INCH TO ONE INCH RAIN IS LIKELY OVER DDC CWA. IT IS TOUGH TO PINPOINT WHICH PORTION OF CWA WILL SEE THE MOST RAIN...BUT MY GUT TELLS ME THE SOUTHEAST CWA MAY SEE THE MOST RAIN WITH A CONVECTIVE ROUND EARLY (THIS AFTN) FOLLOWED BY THE STRATIFORM RAINFALL TONIGHT. 1.50"+ IS POSSIBLE. FORECAST FOR FRIDAY/FRI NIGHT WAS ESSENTIALLY UNCHANGED. -UMSCHEID DAYS 3-7... OTHER THAN A FEW MINOR CHANGES, PRETTY MUCH LEFT THE EXTENDED GRIDS ALONE. ON SUNDAY, THE CENTRAL PLAINS WILL BE UNDER ZONAL FLOW ALOFT WITH SHORTWAVE FORECAST TO BE OVER THE GREAT BASIN. LEE SIDE TROUGHING AND WARM AIR ADVECTION WILL BE IN PROGRESS. THE ECMWF IS THE MOST AGGRESSIVE WITH THE WARMER AIR WHILE THE GFS IS A LITTLE MORE CONSERVATIVE. THE EC MAY BE A LITTLE OVERDONE AS IT SEEMS TO HIT THE 850 TEMPS A LITTLE HARD AT TIMES. WITH THAT IN MIND, WILL BACK OFF A FEW DEGREES INTO THE MID 70S FOR HIGHS ACROSS MUCH OF THE CWA. ------------------------------------------------------------------------ * PRELIMINARY POINT TEMPS/POPS* DDC 53 40 63 37 / 90 100 10 0 GCK 50 36 63 36 / 90 100 0 0 EHA 51 36 62 38 / 90 100 0 0 LBL 52 38 64 38 / 90 100 0 0 HYS 51 40 63 37 / 90 100 10 0 P28 61 45 65 39 / 60 100 20 0 ------------------------------------------------------------------------ * DDC WATCHES/WARNINGS/ADVISORIES* WIND ADVISORY FROM 10 PM THIS EVENING TO 1 PM CDT FRIDAY FOR KSZ030-KSZ031-KSZ045-KSZ046-KSZ064-KSZ065-KSZ066-KSZ078-KSZ079- KSZ080-KSZ081-KSZ088-KSZ089-KSZ090. DENSE FOG ADVISORY UNTIL 9 AM CDT /8 AM MDT/ THIS MORNING FOR KSZ043-KSZ061-KSZ062-KSZ063-KSZ074-KSZ075-KSZ076-KSZ077-KSZ084- KSZ085-KSZ086-KSZ087-KSZ088. WIND ADVISORY FROM 7 PM CDT /6 PM MDT/ THIS EVENING TO 7 AM CDT /6 AM MDT/ FRIDAY FOR KSZ043-KSZ044-KSZ061-KSZ062-KSZ063-KSZ074- KSZ075-KSZ076-KSZ077-KSZ084-KSZ085-KSZ086-KSZ087. ------------------------------------------------------------------------ ------------------------------------------------------------------------ FN25/02 ** *CLICK HERE TO GO TO PREVIOUS BULLETINS. * ------------------------------------------------------------------------ The Nexlab KS Page Main Text Page