000
FXUS63 KDDC 252322
AFDDDC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DODGE CITY KS
622 PM CDT SAT MAY 25 2013

...UPDATED AVIATION SECTION FOR 00Z TAFS...

.SYNOPSIS...
ISSUED AT 217 PM CDT SAT MAY 25 2013

PAST MORNING UPPER AIR DATA ALONG WITH RECENT WATER VAPOR IMAGERY
REVEALS AN OMEGA BLOCK PATTERN ACROSS NORTH AMERICA THIS
AFTERNOON. A RIDGE EXTENDS FROM THE SOUTHERN GREAT PLAINS INTO THE
NORTHWEST TERRITORIES OF CANADA WHILE BROAD CYCLONIC FLOW EXISTS
OVER THE NORTHEAST AND PACIFIC NORTHWEST REGIONS OF THE COUNTRY.
THIS IS LEAVING SOUTHWEST KANSAS AT THE TAIL END OF THE WESTERLIES
AS A VERY WARM AND DRY SOUTHWEST FLOW REGIME IS DOMINATING OVER
THE SOUTHERN HIGH PLAINS. TEMPERATURES OF +10 TO +14C AT 700 HPA
AND A RESULTANT STRONG ELEVATED MIXED LAYER IS SPREADING OVER THE
CENTRAL HIGH PLAINS. CLOSER TO THE GROUND...THE LEE TROUGH
CONTINUES TO DEEPEN OVER EASTERN COLORADO INTO WYOMING WITH A WEAK
DRYLINE STRUCTURE IN PLACE NEAR THE COLORADO BORDER THIS AFTERNOON
VIA DEWPOINTS IN THE 50S ON THE EAST SIDE WHILE 30S TO 40S EXIST
ON THE WEST SIDE. TEMPERATURES IN THE 80S TO NEAR 90 ALONG WITH
THE AFOREMENTIONED DEWPOINTS IN THE 50S...IS PRODUCING MLCAPE
VALUES NEAR 2000 J/KG WEST OF HIGHWAY 83 BUT WITH DECENT INHIBITION
REMAINING...EVEN SHALLOW CUMULUS IS MOSTLY ABSENT THIS EARLY
AFTERNOON.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 348 PM CDT SAT MAY 25 2013

AS THE REGION HEADS INTO LATE THIS AFTERNOON TO EVENING...A SMALL
SHORTWAVE CURRENTLY MOVING OVER THE CENTRAL/SOUTHERN ROCKIES...WILL
RIDE OVER THE AFOREMENTIONED DRYLINE.  ALTHOUGH A WARM ELEVATED
MIXED LAYER WILL INHIBIT MOST CONVECTION...CAN/T RULE OUT THIS WAVE
WEAKENING THE CAP ENOUGH TO TRIGGER AN ISOLATED STORM OR TWO MAINLY
NEAR THE COLORADO BORDER.  ALTHOUGH INSTABILITY WILL BE DECENT VIA
MLCAPE VALUES OF 1500-2000 J/KG, WEAK 0-6 KM AGL BULK SHEAR OF 20-30
KNOTS WILL LIMIT STORMS TO MOSTLY A MULTICELL MODE WITH MARGINAL
SEVERE HAIL THE PRIMARY THREAT. OTHERWISE, ANTICIPATE ANY
CONVECTION THAT DOES DEVELOP NEAR THE COLORADO BORDER...WILL FADE
QUICKLY AFTER SUNSET AS INHIBITION INCREASES AND THE NOSE OF A 40
KNOT LOW LEVEL JET FOCUSES MORE INTO NEBRASKA FOR ELEVATED
NOCTURNAL CONVECTION. THIS WILL LEAVE A QUIET OVERNIGHT WITH ONLY
SOME PATCHY LOWER STRATUS BACKING INTO THE HAYS TO PRATT AREAS
WHILE TEMPERATURES FALL INTO THE 60S FOR LOWS.

SUNDAY WILL SEE THE UPPER PATTERN CHANGE LITTLE IF ANY AS A RIDGE
REMAINS OVER THE GREAT PLAINS WHILE ONE WAVE SITS OVER THE NORTHEAST
AND ANOTHER OVER NORTHWEST PORTIONS OF THE COUNTRY. NONETHELESS...A
60-70 KNOT SUBTROPICAL JET ON THE BASE OF THE TROUGH WILL NOSE
INTO THE CENTRAL HIGH PLAINS BY LATE AFTERNOON. IN RESPONSE TO
ASCENT ASSOCIATED WITH THIS JET STREAK...THE LEE TROUGH WILL PUSH
EASTWARD INTO WESTERN KANSAS AND FORM A DRYLINE ROUGHLY ALONG THE
HIGHWAY 83 CORRIDOR BY LATE AFTERNOON. AHEAD OF THE
DRYLINE...TEMPERATURES CLIMBING INTO THE MID TO UPPER 90S ALONG
WITH DEWPOINTS IN THE MID 50S TO NEAR 60 WILL RESULT IN HIGH
INSTABILITY VIA MLCAPE OF 2000-2500 J/KG BY LATE AFTERNOON.
ALTHOUGH INHIBITION WILL REMAIN STRONG...LARGER SCALE ASCENT FROM
THE JET STREAK MAY ALLOW ONE OR TWO STORMS TO BREAK THE CAP.
UNLIKE TODAY...DEEP LAYER SHEAR WILL BE STRONGER AND SHOULD
SUPPORT ROTATING UPDRAFTS WITH HAIL UP TO TENNIS BALL SIZE
POSSIBLE. THE OTHER ISSUE FOR THE DAY WILL BE POTENTIAL FOR
CRITICAL FIRE WEATHER CONDITIONS WEST OF THE DRYLINE. SEE FIRE
WEATHER SECTION BELOW FOR ADDITIONAL DETAILS.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 400 PM CDT SAT MAY 25 2013

SEVERAL CHALLENGES EXIST THIS PERIOD...RANGING FROM ELEVATED
WILDFIRE CONDITIONS TO A HEIGHTENED SEVERE WEATHER RISK. THE FIRST
OPPORTUNITY FOR AT LEAST SCATTERED THUNDERSTORMS WITH AT LEAST A
SMALL RISK OF SEVERE THUNDERSTORMS WILL BE SUNDAY EVENING. THE DRY
LINE WILL ADVANCE EAST INTO THE CENTRAL PART OF SOUTHWEST KANSAS
PROVIDING ENOUGH CONVERGENCE FOR STORMS. HOWEVER, THE ELEVATED
MIXED LAYER (EML) MAY BE JUST TOO WARM TO SUPPORT MUCH COVERAGE.
THE BEST OPPORTUNITY FOR SEVERE STORMS WILL BE ACROSS NORTHWEST
AND NORTH CENTRAL KANSAS AND NORTH. I WILL CARRY SMALL POPS FOR
NOW.

FOR MONDAY THE EML MAY STRENGTHEN AS SOUTHWEST FLOW ALOFT
STRENGTHENS AND THE DRY LINE SURGES FARTHER EAST. MONDAY MAY ALSO
BE THE HOTTEST DAY OF THE WEEK AS DEEP MIXING WILL PROMOTE VERY
WARM SURFACE TEMPERATURES. MONDAY WILL ALSO BE THE MOST LIKELY DAY
FOR AN ELEVATED WILDFIRE RISK, ESPECIALLY ACROSS THE FAR WEST
WHERE BOUNDARY LAYER MOISTURE WILL MIX TO VERY DRY READINGS. ALONG
THE DRYLINE THERE MAY BE JUST ENOUGH LIFT TO OVERCOME THE VERY
WARM MID-LEVEL TEMPERATURES AND ISOLATED CONVECTION MAY RESULT.

TUESDAY AND WEDNESDAY MAY THE "BIG" DAYS FOR THUNDERSTORMS AS THE
WESTERN U.S. TROUGH BEGINS TO EJECT OUT OF THE WEST. TIMING WILL
BE THE ISSUE WITH THE GFS BEING THE FASTER SOLUTION. AS OF NOW IT
APPEARS THAT THE THREAT OF SEVERE WEATHER WILL BE INCREASING AS
MID-LEVEL COOLING AND INCREASING FLOW ALOFT WOULD BE SUFFICIENT TO
PROVIDE AN ENVIRONMENT FAVORABLE FOR SEVERE WEATHER. THIS FAR OUT
DETAILS ARE UNCERTAIN.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 617 PM CDT SAT MAY 25 2013

PREVAILING SOUTH TO SOUTHEAST WIND WILL CONTINUE THIS EVENING
THROUGH SUNDAY AS THE LEE TROUGH REMAINS ANCHORED ACROSS FAR
EASTERN COLORADO. ISOLATED TO WIDELY SCATTERED THUNDERSTORMS THAT
FORMED ALONG THE DRYLINE/LEE TROUGH ALONG THE COLORADO BORDER ARE
NOT EXPECTED TO IMPACT THE GCK, DDC, OR HYS TERMINALS. TAF
AMENDMENTS WILL BE REQUIRED SHOULD ANY OF THESE STORMS THREATEN
THE TERMINALS THIS EVENING, HOWEVER. DURING THE 10-15Z TIME FRAME
EARLY SUNDAY...LOW STRATUS AND LIGHT FOG SHOULD DEVELOP AS MOIST
BOUNDARY LAYER AIR MOVES NORTH-NORTHWEST ON THE LOW LEVEL JET.
THERE IS EXPECTED TO BE A 3 TO 5 HOUR PERIOD OF IFR CATEGORY AND
WILL BE FORECAST FOR THE DDC, GCK, AND HYS TAF EARLY SUNDAY MORNING.

&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  63  96  66  97 /  20  10  10  10
GCK  63  98  65  97 /  20  10  10  10
EHA  61  98  63  98 /  20   0  10  10
LBL  63 100  65  99 /  20  10  10  10
HYS  64  92  67  93 /  10  20  20  20
P28  65  90  68  92 /  10  10  10  10

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...AJOHNSON
SHORT TERM...AJOHNSON
LONG TERM...HUTTON
AVIATION...UMSCHEID