000
FXUS63 KDDC 181955
AFDDDC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DODGE CITY KS
255 PM CDT SAT MAY 18 2013

...UPDATED AVIATION SECTION...

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 253 PM CDT SAT MAY 18 2013

A STRONG UPPER LEVEL TROUGH CURRENTLY ACROSS THE ROCKIES WILL
CONTINUE TO MOVE TO THE EAST AND STRENGTHEN INTO AN UPPER LEVEL LOW
ACROSS THE NORTHERN PLAINS TOMORROW. AN UPPER LEVEL JET CURRENTLY
EXTENDS SOUTHEASTWARD ACROSS NEVADA INTO THE FOUR CORNERS REGION AND
IS EXPECTED TO ADVECT INTO THE CENTRAL PLAINS TOMORROW. STRONG
SOUTHWESTERLY WINDS ARE DEPICTED IN THE MID LEVELS OF THE ATMOSPHERE
WITH A STRONG WARM TONGUE AROUND 800 MB. TOWARDS THE SURFACE, AN
AREA OF LOW PRESSURE WILL INTENSIFY ACROSS THE KS/CO BORDER THIS
AFTERNOON WITH A DRYLINE EXTENDING FROM SCOTT CITY TO LIBERAL.
TEMPERATURES THIS AFTERNOON WILL SOAR INTO THE LOWER 90S BEHIND THIS
FRONT WITH UPPER 80S TO AROUND 90 DEGREES EAST OF THIS DRYLINE. VERY
MOIST AIR HAS ADVECTED INTO KANSAS AHEAD OF THIS DRYLINE WITH
DEWPOINTS IN THE 60S. WITH WARM TEMPERATURES AND AMPLE MOISTURE AT
THE SURFACE, CAPE VALUES OF OVER 4000 J/KG WILL BE FOUND ACROSS MUCH
OF THE FORECAST AREA. THIS WILL ALLOW STORMS TO FORM FIRST JUST
AHEAD OF THE DRYLINE LATE THIS AFTERNOON THEN SPREAD EAST ACROSS THE
REMAINDER OF THE FORECAST AREA THIS EVENING. STORMS THEN MOVE INTO
WICHITA`S FORECAST AREA OVERNIGHT. A FEW OF THESE STORMS WILL BECOME
SEVERE WITH LARGE HAIL UP TO BASEBALL SIZE AND WIND GUSTS ABOVE 60
MPH BEING THE MAIN CONCERN. AN ISOLATED TORNADO CAN NOT BE RULED
OUT, MAINLY LATER THIS EVENING ACROSS CENTRAL AND SOUTH CENTRAL
KANSAS WHEN THE LOW LEVEL JET KICKS IN. CLOUDY SKIES CONTINUE
THROUGHOUT THE NIGHT WITH A SURFACE COLD FRONT MOVING THROUGH A
MAJORITY OF WESTERN KANSAS BY SUNRISE. AS FOR TEMPERATURES, LOWS
TONIGHT ARE FORECASTED TO BE IN THE 60S.

THE COLD FRONT WILL MOVE THROUGH THE REMAINDER OF THE FORECAST AREA
TOMORROW MORNING SHIFTING WINDS TO THE NORTHWEST. CLOUDY SKIES WILL
BE OBSERVED ACROSS WESTERN KANSAS IN THE MORNING WITH SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS POSSIBLE DUE TO AMPLE MID LEVEL
MOISTURE AND STEEP LAPSE RATES. SKIES CLEAR FROM WEST TO EAST IN THE
AFTERNOON AS HIGH PRESSURE BUILDS INTO THE AREA. A FEW STRONG
THUNDERSTORMS WILL BE POSSIBLE ACROSS SOUTH CENTRAL KANSAS IN THE
MID AFTERNOON BUT MOST LIKELY MOST OF THE CONVECTION WILL BE ACROSS
WICHITA`S FORECAST AREA. COOLER TEMPERATURES WILL BE OBSERVED ACROSS
WESTERN KANSAS TOMORROW WITH HIGHS RANGING FROM THE MID 70S ACROSS
WEST CENTRAL KANSAS TO LOWER 80S ACROSS THE KS/OK BORDER AND SOUTH
CENTRAL KANSAS.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 400 AM CDT SAT MAY 18 2013

THE COLD UPPER LEVEL TROUGH EXTENDING FROM WESTERN UTAH TO
ARIZONA WILL PROGRESS EASTWARD TOWARD THE CENTRAL PLAINS SUNDAY,
AND THE NUMERICAL MODELS ARE IN GOOD AGREEMENT WITH EVOLUTION OF A
CLOSED CYCLONE IN NEBRASKA BY SUNDAY AFTERNOON. A STRONG JET
SEGMENT WITH A VORTICITY MAXIMUM EVIDENT ON SATELLITE IMAGERY NEAR
127W WILL DIG INTO THE SOUTHWESTERN PART OF THE COUNTRY MONDAY AND
WILL APPROACH WESTERN KANSAS MONDAY NIGHT. A VERY BLOCKY FLOW
REGIME WILL PREVAIL THROUGH MUCH OF NEXT WEEK AS UPPER LEVEL
ANTICYCLOGENESIS OCCURS IN SOUTHERN SASKATCHEWAN AND MANITOBA
MONDAY AND TUESDAY, AND UNSEASONABLY COLD MID LEVEL TEMPERATURES
WITH BROAD CYCLONIC UPPER LEVEL FLOW WILL PERSIST ACROSS KANSAS
THROUGH MID WEEK. UPPER LEVEL RIDGING WILL BUILD IN THE CENTRAL
UNITED STATES AS THE UPPER LEVEL CYCLONE FINALLY PROGRESSES EAST
THURSDAY AND FRIDAY. A COOL SURFACE ANTICYCLONE WILL BUILD EAST OF
THE CANADIAN UPPER LEVEL ANTICYCLONE, AND A RIDGE OF HIGH PRESSURE
WILL BUILD INTO THE CENTRAL PART OF THE COUNTRY THURSDAY AND
FRIDAY. MOIST UPSLOPE FLOW WILL FAVOR CONSIDERABLE CLOUDINESS AND
ENHANCED CHANCES FOR RAINFALL THURSDAY THROUGH SATURDAY.

TROPICAL THUNDERSTORMS HAVE BEEN ACTIVE FOR THE LAST WEEK NEAR THE
MARITIME CONTINENT AND ACROSS THE INDIAN OCEAN. THE GFS SUGGESTS
THAT A COHERENT CLUSTER PROJECTING ONTO A MADDEN-JULIAN OSCILLATION
WILL MOVE INTO THE WESTERN HEMISPHERE NEXT WEEK, BUT THE ECMWF IS
MUCH LESS AGGRESSIVE WITH AN EASTWARD PROPAGATING SIGNAL. THE GFS
MAY BE PICKING UP ON A FASTER PROPAGATING MODE OF CONVECTION, AND
THE MORE CONSERVATIVE ECMWF SEEMS MORE REASONABLE. RELATIVE
ATMOSPHERIC ANGULAR MOMENTUM STILL IS ABOVE CLIMATOLOGY, BUT THE
TENDENCY IS NEGATIVE. THE GENERAL FLOW IS TRENDING WEAKLY TOWARD
PHASE 8 OF THE BERRY-WEICKMANN PHASE-SPACE DIAGRAM, AND THIS PATTERN
FAVORS CYCLONIC FLOW IN THE WESTERN UNITED STATES. THE DETERMINISTIC
MODELS ARE IN GOOD AGREEMENT WITH DEVELOPING AN UPPER LEVEL LOW IN
THE PACIFIC NORTHWEST TUESDAY, AND THIS SEEMS REASONABLE.

A PACIFIC COLD FRONT WILL PROGRESS INTO CENTRAL KANSAS BY EARLY
SUNDAY AFTERNOON, AND SEVERE THUNDERSTORMS LIKELY WILL DEVELOP FROM
OKLAHOMA INTO EASTERN KANSAS NEAR THE FRONT. MUCH COOLER AIR IN THE
MID LEVELS OF THE ATMOSPHERE WILL INVADE WESTERN KANSAS SUNDAY, AND
MID LEVEL INSTABILITY AND UPWARD VERTICAL MOTION IN ADVANCE OF THE
VIGOROUS UPPER LEVEL TROUGH WILL FAVOR DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS SUNDAY MORNING IN FAR WESTERN KANSAS. WITH SURFACE
HEATING DURING THE DAY, SHOWERS AND THUNDERSTORMS WILL BECOME MORE
WIDESPREAD. WITH H5 TEMPERATURES AROUND -15C SUNDAY AFTERNOON AND
MORE THAN 1000 J/KG OF CAPE, THERE PROBABLY WILL BE HAIL WITH A FEW
OF THE THUNDERSTORMS. TEMPERATURES WILL WARM INTO THE MID 80S IN
SOUTH CENTRAL KANSAS WHERE LITTLE COLD AIR ADVECTION WILL OCCUR
UNTIL LATE AFTERNOON, WHILE HIGHS WILL REACH ONLY THE LOWER 70S NEAR
THE COLORADO BORDER. THUNDERSTORM ACTIVITY WILL WEAKEN WITH LOSS OF
HEATING SUNDAY EVENING.

A TROUGH ROTATING AROUND THE COLD UPPER LEVEL CYCLONE WILL CARRY A
REINFORCING SURGE OF COLD AIR INTO KANSAS MONDAY, AND CHANCES FOR
LARGELY DIURNAL SHOWERS AND THUNDERSTORMS UNDER THE UPPER LEVEL COLD
POOL WILL CONTINUE. ANOTHER UPPER LEVEL TROUGH WILL APPROACH THE
CENTRAL PLAINS TUESDAY, AND ANOTHER ROUND OF SHOWERS CAN BE EXPECTED
PRIMARILY FROM WEST CENTRAL INTO NORTH CENTRAL KANSAS. WEDNESDAY
SHOULD BE QUIET WITH UPPER LEVEL RIDGING AND LIMITED INSTABILITY. BY
THURSDAY, LOW LEVEL MOISTURE WILL BEGIN TO FLOW BACK INTO THE HIGH
PLAINS ON THE WEST SIDE OF THE EXTENSIVE SURFACE ANTICYCLONE, AND
THUNDERSTORMS ARE LIKELY TO DEVELOP IN EASTERN COLORADO AND
PROPAGATE INTO WESTERN KANSAS DURING THE EVENING AND NIGHTTIME
HOURS. THE ECMWF IS MORE AGGRESSIVE THAN THE GFS WITH WEAKENING THE
RIDGE IN THE CENTRAL PLAINS AND SPREADING WARM MID LEVEL
TEMPERATURES INTO WESTERN KANSAS, BUT THE SLOWER EVOLUTION OF THE
GFS SEEMS MORE REASONABLE GIVEN THE BLOCKY FLOW REGIME THAT HAS
PERSISTED THIS MONTH. TEMPERATURES WILL BE NEAR OR BELOW SEASONAL
AVERAGES WITH HIGHS GENERALLY IN THE 70S AND LOWER 80S.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1232 PM CDT SAT MAY 18 2013

VFR CONDITIONS WILL BE OBSERVED THIS AFTERNOON WITH THE EXCEPTION
OF THE HAYS AREA OVER THE NEXT HOUR DUE TO LEFT OVER CLOUDS AOA030 FROM
LAST NIGHT. THESE CLOUDS SHOULD MOVE OUT OF THE AREA BY 19Z
LEAVING VFR CONDITIONS. THUNDERSTORMS ARE POSSIBLE ACROSS THE TAF
SITES LATE THIS AFTERNOON INTO THIS EVENING AS A STRONG UPPER
LEVEL DISTURBANCE MOVES THROUGH THE AREA. THESE STORMS ARE
ANTICIPATED TO FORM ALONG A DRYLINE ACROSS WESTERN KANSAS FIRST
THEN SPREAD ACROSS THE REMAINDER OF WESTERN KANSAS AS THE EVENING
PROGRESSES. I HAVE KEPT A VCSH IN THE TAFS FOR NOW BUT MAY NEED TO
BE UPDATED LATER ON WHEN STORMS START TO DEVELOP. THESE STORMS
MOVE INTO CENTRAL AND SOUTH CENTRAL KANSAS BY MIDNIGHT WITH MOSTLY
CLEAR SKIES OBSERVED. WINDS WILL GENERALLY BE FROM THE SOUTH
SOUTHEAST AT 15 TO 20 KNOTS THIS AFTERNOON INTO TONIGHT GUSTING TO
AROUND 25 KNOTS AT TIMES. HIGHER GUSTS WILL BE POSSIBLE UNDER AND
AROUND THUNDERSTORMS.


&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  61  80  53  79 /  30  50  20  30
GCK  60  79  52  77 /  10  50  20  20
EHA  60  80  52  74 /  10  20  20  20
LBL  60  82  52  77 /  10  40  10  30
HYS  63  80  54  77 /  70  50  30  30
P28  65  85  58  82 /  70  30  20  30

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 9 PM CDT /8 PM MDT/ THIS EVENING FOR
KSZ061-062-074-075-084-085.

&&

$$


SHORT TERM...HOVORKA_42
LONG TERM...RUTHI
AVIATION...HOVORKA_42