Area Forecast Discussion
Issued by NWS Goodland, KS

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000
FXUS63 KGLD 291952
AFDGLD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GOODLAND KS
152 PM MDT MON SEP 29 2014

.UPDATE...
ISSUED AT 1137 AM MDT MON SEP 29 2014

UPDATE TO ZONES HAS BEEN ISSUED TO ADJUST SKY COVER FOR WESTERN
ZONES AND TO BUMP UP DAYTIME HIGHS BASED ON LATEST HOURLY OBS.
MANY SPOTS ACROSS THE AREA FOR TEMPERATURES ARE RUNNING CLOSE TO
FORECASTED HIGHS...SO HAVE INCREASED BY A COUPLE DEGREES. HAVE
INTRODUCED PSUNNY CONDITIONS TO WESTERN ZONES AS LINGERING CLOUDS
FROM THIS MORNING REMAIN. WIND ADVISORY UPDATE...CONDITIONS REMAIN
INTACT FOR STRONG WINDS ACROSS THE AREA. NO CHANGE TO GOING
PRECIPITATION FORECAST. HAVE CONTINUED SL CHANCE FOR WESTERN ZONES
THIS AFTERNOON AS LINGERING RW REMAIN OVER EASTERN COLORADO.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 426 AM MDT MON SEP 29 2014

MAIN FORECAST CONCERN WILL BE ACTIVE WEATHER THROUGH TONIGHT
WITH SECONDARY CONCERN WITH THE NEXT CHANCE OF PRECIPITATION
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. SATELLITE IS SHOWING AN
AMPLIFIED PATTERN FROM THE CENTRAL PACIFIC INTO EASTERN NORTH
AMERICA. STRONG AND SLOW MOVING UPPER SYSTEM OVER THE GREAT BASIN
WILL BE THE MAIN PLAYER FOR OUR WEATHER THROUGH TONIGHT.

NEXT UPPER SYSTEM IS DIGGING TOWARD SOUTHWEST CANADA. SUBTROPICAL
MOISTURE AHEAD OF GREAT BASIN SYSTEM HAS SURGED NORTH FROM
YESTERDAY. LOW LEVEL MOISTURE JUST TO OUR SOUTH IS SHOWING AN
INCREASE FROM YESTERDAY. AT JET LEVEL THE MODELS INITIALIZED WELL
AND CLOSE WITH THE CANADIAN...ECMWF...NAM AND GFS DOING THE BEST.

AT MID LEVELS...THE GFS...CANADIAN...UKMET AND ECMWF WERE DOING A
LITTLE BETTER THAN THE NAM. THE NAM WAS DOING A LITTLE BETTER THAN
THE ECMWF AND SREF ON THE LOW LEVEL SURFACE WIND AND PRESSURE
FIELD. THE MODELS INITIALIZE WELL AND CLOSE ON THE LOW LEVEL
THERMAL FIELD.

TODAY/TONIGHT...FIRST THE WIND. LAPSE RATES...PRESSURE
GRADIENT...3 HOUR PRESSURE FALLS...AND 850 TO 700 MB WINDS WOULD
SUPPORT HAVING A WIND ADVISORY FOR LOCATIONS ALONG AND WEST OF THE
COLORADO BORDER. AS A RESULT...DECIDED TO ISSUE A WIND ADVISORY
FOR THE AFTERNOON THE COUNTIES ALONG THE COLORADO BORDER.

HEIGHT FALLS WOULD INDICATE THE MAIN CORE OF THE CENTER WILL BE
GOING TOWARD WYOMING. MODEL OUTPUT CONTINUES TO GRADUALLY SLOW
THIS SYSTEM DOWN. BY LATE IN THE AFTERNOON THE MAIN UPPER JET/LIFT
IS OVER EXTREME EASTERN COLORADO. MAIN SURFACE CONVERGENCE IS ALSO
JUST WEST OF THE FORECAST AREA BY LATE IN THE DAY. MODELS HAVE
SLOWED THE ONSET OF THUNDERSTORM DEVELOPMENT SO LOWERED THE
AFTERNOON POPS. HOWEVER...ONCE THE STORMS DEVELOP THEY SHOULD GO
SEVERE DUE TO THE AMOUNT SHEAR...INSTABILITY AND STRONG LIFT.

NEWER MODEL DATA SUPPORTS THE PREVIOUS FORECAST. THROUGH THE
EVENING EITHER A LEFT FRONT QUADRANT OR COUPLED JET IS AFFECTING
THE NORTHWEST HALF. AFTER MIDNIGHT...RIGHT REAR QUADRANT OF THE
JET IS AFFECTING THE SOUTHEAST HALF. VERY STRONG MID LEVEL FORCING
WILL ALSO MOVE ACROSS THE AREA. JUST MADE MINOR ADJUSTMENTS TO THE
POPS BASED ON THE LATEST TRENDS. SEVERE THUNDERSTORMS WILL BE
CONTINUING THROUGH THE EVENING. HIGH PRECIPITABLE WATER VALUES
WILL BE IN PLACE. DESPITE THE STRONG STEERING FLOW...THUNDERSTORMS
LOOK TO TRAIN WITH SLOW EASTWARD MOVEMENT EXPECTED. AS A RESULT
MODERATE TO HEAVY RAINFALL COULD OCCUR.

TUESDAY/TUESDAY NIGHT...RIGHT REAR QUADRANT OF THE JET IS
CONTINUES TO AFFECT THE SOUTHEAST HALF THIRD TO HALF THROUGH THE
MORNING. THAT AND LINGERING MID LEVEL LIFT COULD KEEP
PRECIPITATION THROUGH THE MORNING IN THAT AREA. PREVIOUS FORECAST
HAD THAT HANDLED WELL AND DID NOT CHANGE.

AFTER MIDNIGHT A RATHER STRONG LEFT FRONT QUADRANT OF THE UPPER
JET BEGINS TO AFFECT MOST OF THE AREA...ESPECIALLY THE NORTH HALF
TO TWO THIRDS. THERE LOOKS TO ALSO TO BE DECENT FORCING AS
EVIDENCED BY A RATHER STRONG PV ANOMALY. THETA-E LAPSE RATES ARE
LOW ENOUGH THAT THE AIR MASS SHOULD RESPOND WELL TO THE LIFT. IF
CURRENT LIFT AND INSTABILITY TRENDS CONTINUE...POPS MAY NEED TO BE
RAISED MORE.

WEDNESDAY/WEDNESDAY NIGHT...ABOVE MENTIONED JET GRADUALLY MOVES NORTH
AND EAST AND BY LATE IN THE AFTERNOON DIVIDES THE FORECAST AREA IN
HALF FROM SOUTHWEST TO NORTHEAST. A SHORTWAVE TROUGH MOVES
SOUTHWEST TO NORTHEAST ACROSS THE AREA. DUE TO GOOD LIFT DECIDED
TO RAISE POPS INTO A HIGHER CHANCE CATEGORY OVER MOST OF THE AREA.
AGAIN IT IS POSSIBLE THAT POPS MAY NEED TO BE RAISED MORE. IT MAY
NOT WARM UP MUCH DUE TO CLOUD COVER...PRECIPITATION...AND AN
UNFAVORABLE WIND FIELD. MAXES MAY NEED TO BE LOWERED.

THERE LOOKS TO BE BRIEF BREAK IN THE PRECIPITATION AFTER THE ABOVE
MENTIONED SHORTWAVE TROUGH MOVES THROUGH. BY LATE EVENING UPPER
JET MOVES TO THE EAST OF THE AREA AND LOOKS TO AFFECT THE
SOUTHEAST HALF BEFORE IT LEAVES. INCOMING TROUGH IS LOOKING A
LITTLE STRONGER. THETA-E LAPSE RATES ARE LOW AND SHOULD RESPOND
VERY WELL TO THE LIFT GENERATED BY THIS INCOMING POSITIVELY TILTED
TROUGH. STRONG FRONTOGENETIC FORCING AND PV ANOMALY SHOULD BRING A
VERY CHANCE FOR MEASURABLE PRECIPITATION TO THE AREA AND DID MAKE
ANY MAJOR CHANGES TO THE HIGH POPS ALREADY IN THERE.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 121 PM MDT MON SEP 29 2014

MOISTURE AND INSTABILITY WILL BEGIN TO RETURN NORTHWARD TUESDAY
NIGHT AHEAD OF NEXT SYSTEM ORGANIZING IN THE NORTHERN ROCKIES.
SURFACE BASED PARCELS WILL BE CAPPED. ALTHOUGH THERE WILL BE GOOD
MOISTURE ADVECTION FROM NORTH TO SOUTH...LLJ IS ABSENT. THERE ARE
HINTS OF A WEAK DISTURBANCE EJECTING AHEAD OF THE MAIN SYSTEM
AFTER MIDNIGHT IN THE QVECTOR CONVERGENCE FIELDS. HOWEVER...WITH
MODELS DRY HARD TO JUSTIFY MORE THAN SILENT 10 POPS FOR THE
SITUATION ESPECIALLY GIVEN ABSENCE OF LLJ.

BETTER CHANCES OF PRECIPITATION WILL ARRIVE WITH THE MAIN UPPER
TROUGH AXIS WEDNESDAY AFTERNOON AND ESPECIALLY WEDNESDAY NIGHT.
THE OLD FRONTAL BOUNDARY WILL STILL BE LINGERING ACROSS SOUTHERN
PORTIONS OF THE AREA AS CYCLOGENESIS OCCURS ALONG IT IN EASTERN
COLORADO ASSOCIATED WITH THE NEW SYSTEM. EASTERLY UPSLOPE SURFACE
WINDS WILL BE IN PLACE ACROSS A GOOD PART OF THE FORECAST AREA
NORTH OF THE FRONT RESULTING IN DEEP LAYER SHEAR OF UP TO 50KTS
BY WEDNESDAY AFTERNOON AND MODERATE INSTABILITY OF UP TO 2500
J/KG. SEVERE WEATHER WILL BE POSSIBLE ACROSS THE ENTIRE AREA...IN
ADDITION TO A TORNADO RISK ALONG AND JUST NORTH OF THE SURFACE
BOUNDARY FROM HILL CITY TO RUSSELL SPRINGS WHERE LOW LEVEL SHEAR
WILL BE ENHANCED. THE FRONT WILL BE PUSHED SOUTH AGAIN AFTER 06Z
WITH SEVERE THREAT WANING.

ANY LINGERING SHOWERS/ISOLATED THUNDERSTORMS IN THE EAST THURSDAY
MORNING WILL END AS NORTHWEST FLOW/SUBSIDENCE TAKES OVER BEHIND
THE DEPARTING SYSTEM. NORTHWEST FLOW WILL CONTINUE THROUGH THE
REMAINDER OF THE EXTENDED PERIOD. AT THIS POINT DO NOT SEE ANY
EMBEDDED DISTURBANCES SO AFTER THURSDAY MORNING FORECAST WILL BE
DRY.

TEMPERATURES WILL BE NEAR NORMAL ON WEDNESDAY...THEN BELOW NORMAL
THURSDAY AND FRIDAY...WARMING BACK TO SLIGHTLY ABOVE NORMAL
SATURDAY THROUGH MONDAY AS RIDGE TRIES TO BUILD FROM THE SOUTH AND
WEST.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1137 AM MDT MON SEP 29 2014

MAINLY VFR CONDITIONS EXPECTED FOR BOTH TAF SITES WITH SCT-BKN
LOW AND MID CLDS. FROM 23Z MONDAY THRU 12Z TUESDAY THOUGH...MVFR
CONDITIONS WILL ENSUE AS UPPER LOW TRAVERSES AREA. MENTION OF
TSRA AS SYSTEM PASSES WITH LINGERING VCSH AFTER 06Z-09Z TUESDAY.
WINDS SSE 15-25 KTS WITH GUSTS NEAR 40KTS...BECM SSW 10-15KTS BY
06Z FOR KGLD AND 14Z-15Z FOR KMCK.

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY UNTIL 6 PM MDT /7 PM CDT/ THIS EVENING FOR KSZ001-
     013-027-041.

CO...WIND ADVISORY UNTIL 6 PM MDT THIS EVENING FOR COZ090>092.

NE...WIND ADVISORY UNTIL 6 PM MDT THIS EVENING FOR NEZ079.

&&

$$

UPDATE...JN
SHORT TERM...BULLER
LONG TERM...024
AVIATION...JN



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