Area Forecast Discussion
Issued by NWS Goodland, KS

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000
FXUS63 KGLD 262346
AFDGLD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GOODLAND KS
546 PM MDT SAT JUL 26 2014

.UPDATE...
ISSUED AT 454 PM MDT SAT JUL 26 2014

INCREASED RAINFALL CHANCES OVER MAINLY EAST CENTRAL COLORADO AHEAD
OF THE STORMS MOVING OFF THE HIGHER TERRAIN FURTHER WEST. GENERAL
TREND WITH MODEL DATA HAS BEEN TO SLOW DOWN THE PROGRESSION OF THE
500MB SHORT WAVE TROUGH FOLLOWING THE STORMS. SOUNDINGS DO SHOW
ELEVATED CAPE...WITH THE MOST CAPE/LEAST CINH WHEN LIFTED FROM
700MB OR SO THIS EVENING. HOWEVER TREND IN DATA IS TO PLACE THE
BEST INSTABILITY JUST SOUTH OF THE AREA THEN BRING IT BACK NORTH
OVERNIGHT.

CURRENTLY AM THINKING THE BEST CHANCE FOR STORMS WILL BE OVER THE
SOUTHWEST QUADRANT OF THE AREA WHERE MODELS ALL AGREE THE 500MB
SHORT WAVE TROUGH WILL MOVE TONIGHT. FURTHER EAST AND NORTH THERE
IS LESS CONFIDENCE WHERE ELEVATED INSTABILITY IS HIGHER DUE TO A LACK OF
UPPER LEVEL FORCING TO GENERATE CONVECTION. HOWEVER BASED ON STORM
BEHAVIOR LAST NIGHT...ANY OUTFLOW BOUNDARIES MAY GENERATE FURTHER
CONVECTION DUE TO SOME ELEVATED CAPE PRESENT. DUE TO UNCERTAINTY
IN HOW CONVECTION WILL EVOLVE PAST MID EVENING...WILL LEAVE THE
CURRENT FORECAST AFTER THIS POINT AS IS AND UPDATE AS NEEDED.

&&

.SHORT TERM...(THIS AFTERNOON THROUGH SUNDAY)
ISSUED AT 131 PM MDT SAT JUL 26 2014

LATEST WV IMAGE AND RAP UPPER LEVEL ANALYSIS SHOW BROAD RIDGE STILL
IN PLACE FROM THE DESERT SOUTHWEST ACROSS THE SOUTHERN PLAINS AND
INTO THE SOUTHERN MISSISSIPPI VALLEY. A PLUME OF MONSOONAL MOISTURE
CONTINUES TO ROUND THE WESTERN AND NORTHERN PERIPHERY OF THIS RIDGE
INTO THE CENTRAL ROCKIES AND HIGH PLAINS. A CLOSED LOW IS CENTERED
OVER SOUTHERN MANITOBA CANADA WITH A SHORTWAVE TROUGH OUT AHEAD OF
THIS ENTERING THE NORTHERN MISSISSIPPI VALLEY. AT THE SURFACE LOW
PRESSURE IS IN PLACE OVER OUR CWA WITH SEVERAL WEAK CONVERGENT AREAS
ACROSS OUR SOUTH...AND A COLD FRONT ENTERING NORTHWEST KANSAS FROM
COLORADO AND SOUTHWEST NEBRASKA.

RAP ANALYSIS INDICATES MODERATE SB/MIXED LAYER CAPE VALUES AHEAD OF
MEAN SURFACE TROUGH AXIS ACROSS MOST OF OUR CWA. SHEER IS NOT
PARTICULARLY IMPRESSIVE...HOWEVER WITH SOUNDINGS SHOWING INVERTED V
TYPE SOUNDINGS AND DCAPE 1000 J/KG OR HIGHER MICROBURST POTENTIAL IS
THERE FOR ANY THUNDERSTORM ACTIVITY. GUIDANCE CONTINUES TO FAVOR THE
SOUTHERN PART OF OUR CWA FOR THUNDERSTORM COVERAGE...MAINLY ALONG
AND AHEAD OF COLD FRONT. WEAK FORCING ROTATING FROM THE NORTH
LATER THIS EVENING MAY ALSO SUPPORT ADDITIONAL POST FRONTAL
THUNDERSTORM DEVELOPMENT. POP ADJUSTMENTS WERE MADE TO REFLECT
THESE TRENDS THROUGH TONIGHT. SUBSIDENT AIR MASS APPEARS TO BE IN
PLACE OVER MOST OF THE CWA SUNDAY...THOUGH BY SUNDAY AFTERNOON
UPSLOPE COMBINED WITH OVERRUNNING ALONG STALLED FRONTAL ZONE IN
COLORADO MAY ALLOW FOR SHOWER/THUNDERSTORM DEVELOPMENT INTO THE SW
PART OF THE CWA IN THE AFTERNOON.

TEMPERATURES SATURDAY SHOULD BE COOLER...HOWEVER THERE IS QUITE A
BIT OF SPREAD DUE TO NAM/SREF LINGERING PRECIP MOST OF THE DAY
ACROSS MUCH OF THE CWA. I AM NOT FAVORING THIS SOLUTION AS BETTER
SUPPORT FOR SHOWER/THUNDERSTORM (AND ANY LOW CLOUD COVER) WOULD BE
FURTHER WEST AND SOUTHWEST. IF THE NAM/SREF WERE CORRECT THEN HIGHS
IN THE LOW 80S FOR WESTERN PARTS OF THE CWA. BASED ON THE FAVORED
WARMER SOLUTION WE SHOULD SEE HIGHS WARM TO NEAR NORMAL VALUES IN
THE UPPER 80S FOR A LOT OF THE CWA SUNDAY.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 232 PM MDT SAT JUL 26 2014

SUNDAY NIGHT THROUGH TUESDAY...FORECAST CONCERNS FOR THE PERIOD
INCLUDE COOLING TEMPERATURES AND PRECIPITATION CHANCES...MAINLY IN
THE SOUTHWESTERN PORTION OF THE CWA. NEAR TERM MODELS IN GENERAL
AGREEMENT WITH LARGE SCALE PATTERN AND ALL SUGGEST A MUCH COOLER
START TO THE WEEK THAN THE PAST WEEK.

CWA WILL FIND ITSELF ON THE NORTHEAST FRINGE OF PERSISTENT H5 RIDGE
OVER THE ROCKIES. DESPITE THE RIDGE POSITION...PERIODS OF ASCENT
ACROSS WILL PERIODICALLY DEVELOP AS NUMEROUS SMALL SCALE
DISTURBANCES AND PERSISTENT WEAK WAA REMAIN ACROSS WESTERN HALF OF
THE CWA. ALTHOUGH FORCING IS WEAK...DO NOT SEE ANY REASON WHY MID
LEVELS WILL DRY OUT DURING THE PERIOD AND WITH ELEVATED CAPE PRESENT
THROUGHOUT THINK WE WILL SEE SEVERAL PERIODS OF SHOWERS AND WEAK
THUNDERSTORMS. TRIED TO ADD SOME DIURNAL COMPONENT TO WX TIMING AS
THINK BEST CHANCES WILL BE GENERALLY IN THE OVERNIGHT HOURS AS
MODEST LOW LEVEL JET DEVELOPS TO AID IN MOISTURE ADVECTION/FORCED
ASCENT. GIVEN THE POSITION OF GREATER INSTABILITY AND OVERALL
PATTERN AM NOT EXPECTING LARGE PRECIPITATION AMOUNTS FOR THE PERIOD.
COLD FRONTAL PASSAGE COMBINED WITH PERSISTENT CLOUD COVER WILL
LIKELY LEAD TO MUCH COOLER TEMPERATURES FOR THE PERIOD...ABOUT 10 TO
20 DEGREES COOLER THAN PAST FEW DAYS.

IN THE EXTENDED(TUESDAY NIGHT-SATURDAY)...SIMILAR PATTERN TO
CONTINUE ACROSS TRI STATE AREA THROUGH THE END OF THE WEEK AS H5
RIDGE GRADUALLY AMPLIFIES IN RESPONSE TO TROUGHING DEVELOPING ACROSS
THE SOUTHEAST AND MIDWEST. GEFS AND OPERATIONAL MODELS CONTINUE TO
SUPPORT A HIGH PRECIP POTENTIAL ON TUESDAY NIGHT AND WEDNESDAY AS
MORE SIGNIFICANT SHORT WAVE TROUGH MOVES ACROSS THE AREA. MOISTURE
AND INSTABILITY SHOULD ALREADY BE IN PLACE WITH MAIN CONCERN BEING
HOW FAR NORTH/EAST PRECIP SHIELD WILL GO. STILL THINK BEST CHANCE
FOR RAIN WILL BE ACROSS SOUTHWESTERN CWA SO MADE ONLY MINOR CHANGES
HERE. OTHERWISE...COOLER TEMPERATURES AS A FEW CHANCES FOR LIGHT
PRECIPITATION ARE ANTICIPATED FOR THE PERIOD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 540 PM MDT SAT JUL 26 2014

VFR CONDITIONS FORECAST FOR THE 0Z TAFS. THIS EVENING STORMS MAY
MOVE NEAR THE KGLD SITE. AM NOT TOO OPTIMISTIC SINCE STORMS SHOULD
REMAIN SOUTH OF THE SITE BUT DID KEEP THE MENTION IN SINCE IT WAS
IN THE PREVIOUS TAF. IN ADDITION ANY OUTFLOW BOUNDARIES MAY
GENERATE FURTHER CONVECTION WHICH IS VERY DIFFICULT TO PREDICT
BEFORE HAND SO A MENTION OF VCTS SEEMS FINE. OTHERWISE AS THE COLD
FRONT MOVES THROUGH OVERNIGHT CEILINGS WILL FALL TO NEAR MVFR FOR
A FEW HOURS AT KGLD.

FOR KMCK LIGHT NORTHERLY WINDS WILL PERSIST THROUGH THE PERIOD.
ANY STORMS THAT DEVELOP TONIGHT WILL REMAIN SOUTH OF THE SITE.

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KSZ004-016.

CO...NONE.
NE...NONE.
&&

$$

UPDATE...JTL
SHORT TERM...DR
LONG TERM...JRM
AVIATION...JTL





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