Hail and Damaging Winds in Kansas, August 19, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DODGE CITY KS
400 AM CDT FRI AUG 19 2011

.DISCUSSION...

DAYS 1-2...

A STRONG SHORTWAVE TROUGH WAS PROGRESSING ACROSS SASKATCHEWAN AND MANITOBA
EARLY THIS MORNING. FURTHER SOUTH, AN UPPER-LEVEL RIDGE WAS ANCHORED
ACROSS THE SOUTHERN ROCKIES AND SOUTHERN PLAINS. IN THE CONFLUENT
REGION BETWEEN THESE TWO FEATURES, A HIGH-LEVEL JET STREAK WILL
GRADUALLY PROGRESS ACROSS THE CENTRAL PLAINS TODAY AND INTO THE MIDWEST
BY SATURDAY. THIS WILL PLACE SOUTHWEST KANSAS IN THE ENTRANCE REGION
BY FRIDAY EVENING. IN ADDITION, A LARGE CLUSTER OF STORMS MOVING
SOUTHEASTWARD ACROSS EASTERN KANSAS AND WESTERN MISSOURI EARLY THIS
MORNING WILL LEAVE AN OUTFLOW BOUNDARY SOMEWHERE ACROSS CENTRAL
AND SOUTHERN KANSAS TODAY. A WEAK SURFACE FRONT ALSO EXTENDED FROM
NORTHEASTERN COLORADO INTO NORTHWEST KANSAS. THE POSITION OF THESE
SURFACE FEATURES BY LATE THIS AFTERNOON WILL DETERMINE WHERE
STORMS INITIATE. HIGH DEWPOINTS NEAR 70F IN THE WAKE OF THE MCS
WILL ADVECT WESTWARD ON THE COOL SIDE OF THE BOUNDARIES. SURFACE
BASED CAPE VALUES WILL BE ABOVE 3000 J/KG AS STRONG SURFACE
HEATING DEVELOPS NORTH OF THE FRONT. SURFACE BASED STORMS SHOULD
INITIATE BY LATE AFTERNOON. THESE WILL BE SLOW MOVERS GIVEN THE
WEAK 700-50MB WINDS. HOWEVER, WITH 45-55KT WINDS AT 250MB, HIGH-
LEVEL STORM RELATIVE FLOW OF 45-55KTS (GIVEN NEARLY STATIONARY STORMS)
WILL LEAD TO LONGER LIVED UPDRAFTS THAT COULD PRODUCE HAIL AS LARGE AS
QUARTERS OR GOLFBALLS AND HEAVY RAIN. BY THIS EVENING, A 25-35KT
LOW- LEVEL JET WILL DEVELOP IN THE ENTRANCE REGION OF THE UPPER-
LEVEL JET AND THIS SHOULD AID IN STORM ORGANIZATION. WE ALREADY HAVE
50-60% STORM CHANCES IN THE GRIDS ALONG THE INTERSTATE 70
CORRIDOR, SO ONLY SMALL TWEAKS WERE NEEDED. TEMPERATURES TODAY
WILL OF COURSE DEPEND ON THE EXACT LOCATION OF THE FRONT/OUTFLOW
BOUNDARY. GIVEN THE DOWNSLOPE FLOW ON THE WARM SIDE OF THE
BOUNDARY, TEMPERATURES WILL LIKELY REACH TO BETWEEN 102 TO 107F.
HOWEVER, GIVEN THE RICH MOISTURE AND UPSLOPE FLOW NORTH OF THE
FRONT, TEMPERATURES COULD STAY IN THE 90S AT HAYS AND WAKEENEY.
KEEP IN MIND THAT IF THE OUTFLOW BOUNDARY IS FURTHER SOUTH THAN
EXPECTED, THEN THE HIGH TEMPERATURE IN DODGE CITY COULD BE LESS
THAN 100F.

THE SOUTHERN EDGE OF THE WESTERLIES WILL REMAIN ACROSS KANSAS BY
SATURDAY. OVERNIGHT CONVECTION FRIDAY NIGHT WILL RESULT IN AN
OUTFLOW BOUNDARY SOMEWHERE ACROSS SOUTHERN KANSAS OR NORTHERN
OKLAHOMA. THUNDERSTORMS ARE POSSIBLE AGAIN WHERE THE FRONT STALLS
OUT. TEMPERATURES SHOULD BE COOLER, BUT PROBABLY WARMER THAN THE
LOWER 80S THE NAM SHOWS. ALL THE OTHER MODELS SHOW UPPER 80S NEAR
INTERSTATE 70 AND LOWER 90S NEAR THE OKLAHOMA BORDER.

DAYS 3-7...

IN THE MEDIUM RANGE, MODELS ARE STILL MAINTAINING THE STRONG UPPER
HIGH PRESSURE OVER TEXAS ON SUNDAY, WITH AN AFTERNOON LEE TROUGH
FORMING AT THE SURFACE IN WESTERN KANSAS.  THE SMALL 20 POPS WILL
CONTINUE IN OUR WESTERN ZONES AS AFTERNOON HEATING IN THE TO MID 9OS
WILL MEET THE UPSLOPE CONVERGENCE NEAR THE TROUGH DURING THE LATE
DAY PERIOD SUNDAY.  ALSO THERE IS SIGN OF A SMALL SHORT WAVE TROUGH
CROSSING THE CENTRAL PLAINS OVER THE TOP OF THE UPPER LEVEL HIGH
PRESSURE TO OUR SOUTH SUNDAY.  KEPT THE SMALL 16 PERCENT POPS INTO
THE OVERNIGHT HOURS SUNDAY NIGHT, UNTIL ABOUT 09Z WHEN BOTH THE
LOWER LEVEL AND UPPER LEVEL SUPPORTS WEAKENS.  THEN, POPS WILL BE TO
A MINIMUM UNTIL ABOUT THURSDAY, WHEN A COLD FRONT WILL COME INTO
PLAY.  INTRODUCED 20 POPS IN OUR NORTHERN COUNTIES THURSDAY
AFTERNOON.  RIGHT NOW, AN UPPER WAVE IS NOT EVIDENT IN THE MODELS AT
THAT TIME, BUT THE PRESENCE OF A COLD FRONT IS ENOUGH IN THIS HEAT
REGIME TO KICK OFF A FEW THUNDERSTORMS.  OTHER THAN SUNDAY
EVENING/NIGHT AND THURSDAY AFTERNOON, NO OTHER POPS WILL BE
MENTIONED.  BOTH THESE TIME FRAMES ARE ALSO TARGETED WITH LOW POPS
IN SURROUNDING WFO GRIDS.

AS FOR TEMPERATURES, DID ONLY MINOR TWEAKS TO THE EXISTING GRIDS.
MONDAY WILL BE A WARMING DAY WITH MAX TEMPS RISING TO THE MID 90S IN
THE NORTH AND THE UPPER 90S ALONG THE OKLAHOMA BORDER.  ON TUESDAY,
THE UPPER HIGH PRESSURE WILL SUPPLY BRIGHT SUNSHINE, AND SOUTHWEST
LOW LEVEL WINDS  WILL ADVECT IN PLENTY OF WARM AIR AT THE SURFACE.
THE 100+ MAX TEMPS COULD BE AS FAR NORTH AS DDC TUESDAY.  WEDNESDAY
AND THURSDAY WILL SEE INCREASING CLOUDS WITH THE APPROACH OF COLD
FRONT ON THURSDAY.  TEMPS WILL BE ON A SLIGHT DOWNWARD TREND WED AND
THUR, TOPPING OUT IN THE 93 (N) TO 99 (S) RANGE.  DID KNOCK DOWN
FRIDAY'S MAX TEMP CONSIDERABLY, EVEN THOUGH THAT IS DAY 8, SINCE IT
LOOKS LIKE A COLD FRONT WILL BE MOVING SOUTH THROUGH OUR AREA.  MIN
TEMPS DURING THE EXTENDED PERIOD WILL BE SLIGHTLY ABOVE THE
CLIMATOLOGICAL NORMS, RANGING FROM THE MID 60S IN THE NORTHWEST AND
THE LOWER 70S IN THE SOUTHEAST.

&&

.AVIATION...

VFR CONDITIONS WILL PREVAIL FOR THE MOST PART...WITH A CHANCE FOR
THUNDERSTORMS IN THE KHYS TAF SITE AFTER 20/00Z, AND IN THE KDDC AND
KGCK TAF SITES AFTER 03Z.  A WARM FRONT WILL MOVE NORTH TO NEAR THE
I-70 CORRIDOR LATE THIS AFTERNOON.  IF ANY TAF SITE GOES DOWN IN A
FLIGHT CATEGORY DUE TO EVENING CONVECTION, CIGS WILL BE IN THE MVFR
CATEGORY AROUND BKN040CB AND VSBYS WILL MOST LIKELY REMAIN VFR, WITH
TEMPO VSBY CONDITIONS DOWN TO 3SM POSSIBLE IN THE STRONGER STORMS,
ESPECIALLY IN THE KHYS AREA.

&&

.PRELIMINARY POINT TEMPS/POPS...
DDC 104  70  92  68 /  10  30  20  20
GCK 102  68  90  67 /  10  30  20  20
EHA 102  69  93  67 /  10  30  20  20
LBL 104  70  94  68 /  10  30  20  20
HYS  94  68  87  67 /  20  60  30  20
P28 107  74  92  71 /  10  30  20  20

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING
FOR KSZ081-089-090.

&&

FN24/12/12

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE DODGE CITY KS
825 AM CDT FRI AUG 19 2011

KSZ030-031-043>046-061>066-074>081-084>090-201330-
TREGO-ELLIS-SCOTT-LANE-NESS-RUSH-HAMILTON-KEARNY-FINNEY-HODGEMAN-
PAWNEE-STAFFORD-STANTON-GRANT-HASKELL-GRAY-FORD-EDWARDS-KIOWA-
PRATT-MORTON-STEVENS-SEWARD-MEADE-CLARK-COMANCHE-BARBER-
825 AM CDT FRI AUG 19 2011 /725 AM MDT FRI AUG 19 2011/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL...SOUTH
CENTRAL...SOUTHWEST AND WEST CENTRAL KANSAS.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON ALONG
THE INTERSTATE 70 CORRIDOR AND BECOME MORE NUMEROUS TONIGHT. LOCALLY
HEAVY RAIN IS POSSIBLE WITH THE STRONGEST STORMS, ALONG WITH HAIL
AS LARGE AS QUARTERS AND WIND GUSTS AS HIGH AS 60 MPH. THUNDERSTORMS
MAY ALSO DEVELOP FURTHER SOUTH TONIGHT INCLUDING LOCATIONS SUCH AS
DODGE CITY, LARNED AND ULYSSES, BUT THESE STORMS ARE NOT EXPECTED
TO BE SEVERE.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THERE IS A SLIGHT CHANCE OF THUNDERSTORMS SATURDAY THROUGH SUNDAY
NIGHT ALTHOUGH THESE STORMS ARE NOT EXPECTED TO BE SEVERE. IN
ADDITION...A SLIGHT CHANCE FOR THUNDERSTORMS WILL EXIST NEXT
THURSDAY.

.SPOTTER INFORMATION STATEMENT...

A FEW STORM SPOTTERS WILL PROBABLY BE NEEDED LATE THIS AFTERNOON
AND EVENING ALONG THE INTERSTATE 70 CORRIDOR FROM WAKEENEY TO HAYS.

&&

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