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000
FXUS63 KGLD 181153
AFDGLD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GOODLAND KS
553 AM MDT SAT MAY 18 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 216 AM MDT SAT MAY 18 2013

03Z WATER VAPOR IMAGERY/RUC ANALYSIS INDICATED A WELL DEFINED SHORT
WAVE TROUGH MOVING INTO THE FOUR CORNERS AREA. 00Z SOUNDINGS
INDICATED DEEPENING MOISTURE TO THE SOUTH WITH DDC INDICATING MIXING
RATIOS GREATER THAN OR EQUAL TO 10.5 UP TO 825 MB. FURTHER
WEST...STRONG DRYING WAS NOTED BELOW H6 WITH VERY DRY AIR NOTED AT
H7.  AT THE SFC...TROUGH WAS LOCATED BETWEEN KDNR AND KAKO WITH
DEWPOINTS GREATER THAN 60S IN PLACE ACROSS MUCH OF THE AREA BY 4Z.

MAIN FORECAST CONCERN WILL BE SEVERE WEATHER CHANCES
TODAY...FOLLOWED BY VARIOUS PRECIP CHANCES THROUGH MID WEEK.

TODAY-SUNDAY...WITH OBSERVED SOUNDINGS INDICATING DEEP/GOOD QUALITY
MOISTURE IN PLACE ACROSS THE AREA ALREADY...CONFIDENCE IN POTENTIAL
FOR SEVERE WEATHER THIS AFTERNOON AND EVENING REMAINS FAIRLY HIGH.
WHILE THERE IS A GENERAL CONSENSUS IN THE LARGE SCALE PICTURE WITH
LARGE SCALE FORCING FOR ASCENT INCREASING IN THE AFTERNOON AND
REACHING ITS STRONGEST BTWN 00 AND 06Z. IN THE SMALLER SCALE
THOUGH...NUMEROUS DIFFERENCES BETWEEN VARIOUS OPERATIONAL AND CU
RESOLVING MODELS WITH RESPECT TO POSITION OF DRYLINE/OTHER AREAS OF
NEAR SFC CONVERGENCE. NAM AND HIGH RES CORES HOLD DRYLINE FARTHER
WEST THAN OTHER MODELS...SUGGESTING INITIATION ALONG THE KS/CO
BORDER. OTHER MODELS...MOST NOTABLY THE GFS...PLACE DRYLINE MUCH
FURTHER EAST WITH CONVECTIVE INITIATION ALONG A TRENTON TO RUSSEL
SPRINGS LINE. ALTHOUGH NAM SEEMS TO BE THE MOST EXTREME WITH ITS
POSITION...WITH EXPECTED POSITION OF LARGE SCALE TROUGH TO THE SOUTH
AND WEST OF AREA EXPECT PRESSURE FALLS TO REMAIN TO THE WEST OF THE
AREA THROUGH THE DAY WHICH WOULD TEND TO HOLD DRYLINE TO THE WEST
UNLESS AFTERNOON MIXING CAN OVERWHELM IT. CINH SHOULD BE STRONG
THROUGH MUCH OF THE DAY WITH STRONG INVERSION EXPECTED AROUND H75
SO THINK DELAYING POPS SLIGHTLY UNTIL PEAK HEATING IS IN ORDER.

WITH STORMS INITIATING BTWN 21 AND 00Z IN ENVIRONMENT OF STRONG
INSTABILITY (ML CAPES >3000 J/KG) DEEP LAYER AROUND 40 KTS AND LOW
LEVEL WINDS/HODOGRAPHS INCREASING SEE NO REASON WHY ORGANIZED SEVERE
WEATHER/A FEW SUPERCELLS WILL NOT DEVELOP WITH A SIZABLE THREAT FOR
VERY LARGE HAIL AND POSSIBLY A STRONG TORNADO THROUGH THE EVENING
HOURS. ALTHOUGH STRONG CAP SHOULD TEND TO KEEP STORMS ISOLATED BOTH
DEEP AND 0-3 KM SHEAR CLOSER TO PARALLEL TO THE EXPECTED FORCING AS
OPPOSED TO PERPENDICULAR WHICH MAY FAVOR STORMS BECOMING LINEAR IN
THE EVENING. AFTER INITIAL ROUND OF STRONG THUNDERSTORMS...LARGE
SCALE FORCING COMBINED WITH STRONG FRONTOGENESIS AND LOW STATIC
STABILITY WILL RESULT IN A FEW STORMS THROUGH THE NIGHT ACROSS THE
NORTHERN CWA THROUGH 12Z/

NOT ONLY DOES DRYLINE POSITION PLAY A LARGE ROLE IN SEVERE WEATHER
TODAY...BUT GIVEN AIR MASS JUST TO THE WEST THINK DEWPOINTS WILL
FALL GREATLY WITH AFTERNOON HEATING WITH A FEW DATA SETS INDICATING
MIXED LAYER DEWPOINTS FALLING INTO THE TEENS RESULTING IN NEARLY A
40F DIFFERENCE ACROSS DRYLINE. THIS AREA WILL ALSO BE THE WARMEST
WHICH BRINGS CONCERNS ABOUT CRITICAL FIRE WEATHER. FOR NOW...MOST
LIKELY AREA WOULD BE THE SOUTHWEST LATE IN THE AFTERNOON...BUT
LATEST FUEL DATA IN EASTERN COLORADO INDICATES FUELS ARE NOT
CRITICAL AND AM DOUBTFUL CONDITIONS WILL LAST 3 HOURS IN ADJACENT
AREAS.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 216 AM MDT SAT MAY 18 2013

SUNDAY-MONDAY NIGHT...PATTERN EXPECTED ACROSS THE AREA THROUGH THIS
PERIOD CAN BEST BE DESCRIBED AS UNSETTLED AS SHORT WAVE TROUGH
CONTINUES TO MOVE OVER THE AREA ON SUNDAY...WITH TROUGH BECOMING
ESTABLISHED OVER THE ENTIRE AREA THROUGH THE PERIOD WITH NUMEROUS
SMALL SCALE DISTURBANCES MOVING OVERHEAD. WHILE THERE ARE SOME
DIFFERENCES BETWEEN MODELS WITH RESPECT TO HOW THIS DEVELOPS...AN
OVERALL COOLER PATTERN IS LIKELY. SOUNDINGS SUGGEST LITTLE HEATING
NEEDED ON SUNDAY TO DESTABILIZE ATMOSPHERE WHICH SHOULD RESULT IN
SCATTERED SHOWERS AND THUNDERSTORMS THROUGH MUCH OF THE DAY. GIVEN
NO CLEAR NEAR SFC FORCING MECHANISM...AM HESITANT TO INCREASE POPS
OUTSIDE OF 30-50 RANGE AND HAVE NUDGED GRIDS TO BETTER REFLECT A
MORE DIURNALLY DRIVEN EVENT. NEXT SYSTEM WILL ROUND THE BASE OF LARGE
SCALE TROUGH AND MOVE INTO AREA ON MONDAY. CURRENT FORECAST LOOKS
REASONABLE HERE AND MADE ONLY MINOR CHANGES MAINLY TO COOL TEMPS A
BIT.

UPPER LEVEL CUT OFF LOW WILL BE PRESENT AT 500 MB FOR TUESDAY AND
WEDNESDAY MORNING ACROSS MUCH OF THE UPPER PLAINS REGION. HIGHER
500MB JET MAXES SHOULD REMAIN TO THE SOUTH AND EAST OF THE TRI STATE
AREA.  700MB SHOWS STRONGER JET MAXES OF 35 TO 40 KNOTS AND 850MB
HAS SPEEDS OF 30 TO 35 KNOTS...POSSIBLY ALLOWING FOR SOME SCATTERED
RAIN SHOWERS ACROSS THE REGION.  HIGHER JET SPEEDS WILL MOVE INTO
THE REGION AS THE STAGNANT LOW PRESSURE SYSTEM SPINS OVER THE
NORTHERN PLAINS...WHICH SHOULD PROVIDE SOME UPLIFT FOR SOME RAIN
SHOWERS AND POSSIBLE THUNDERSTORMS TUESDAY. A RIDGE WILL BEGIN TO
BUILD INTO THE AREA AS THE LOW PRESSURE SYSTEM MOVES OUT WEDNESDAY
AFTERNOON.  UPPER RIDGE QUICKLY BECOMES ELONGATED AS THE UPPER FLOW
PATTERN OVER THE COUNTRY DEVELOPS INTO A HIGH AMPLITUDE MERIDIONAL
FLOW.  THE ENSUING TROUGH WILL BUILD TO THE WEST OF THE AREA
THURSDAY AND FRIDAY...WITH MOST OF THE HIGHER JET SPEEDS STAYING TO
THE NORTH AND WEST OF THE HIGH PLAINS AS UPPER LEVEL RIDGE DEFLECTS
THE JET STREAM AROUND THE AREA.  850MB THETA E VALUES REMAIN
MODERATE BETWEEN 310 AND 315 K AND PRECIPITABLE WATER BETWEEN 0.5
AND 0.8 SHOULD BE MOIST ENOUGH FOR SOME SCATTERED RAIN SHOWERS WITH
THE LOW PRESSURE SYSTEM ON TUESDAY AND WEDNESDAY MORNING.  850MB
SHOULD MOISTEN WITH SOUTHEASTERLY FLOW BRINGING GULF MOISTURE INTO
THE AREA.

SURFACE LOW PRESSURE SYSTEM ASSOCIATED WITH THE UPPER LEVEL LOW WILL
SITUATE OVER IOWA WEDNESDAY...BUT WRAP AROUND PRECIPITATION COULD
AFFECT THE AREA FOR TUESDAY AND WEDNESDAY MORNING.  LACK OF
CAPE...UNSTABLE LIFTED INDEX TEMPERATURES...AND LOW TT INDEX
DEMONSTRATES LACK OF SEVERE WEATHER POTENTIAL FOR TUESDAY AND
WEDNESDAY. TEMPERATURES WILL REMAIN COOLER AND SLIGHTLY BELOW
AVERAGE FOR TUESDAY WITH HIGH TEMPERATURES REACHING THE MID 60S.
TEMPERATURES WILL BEGIN TO REBOUND ON WEDNESDAY AS AREA OF HIGH
PRESSURE MOVES INTO THE TRI STATE AREA...WITH HIGH TEMPERATURES
REACHING THE LOW TO MID 70S.  WEDNESDAY LOOKS TO BE DRY...WITH
INCREASING PROBABILITIES OF PRECIPITATION FOR LATE THURSDAY MORNING
AND AFTERNOON AS A WARM FRONT MOVES INTO THE AREA. SOUTHERLY WINDS
WILL ADVECT MORE WARM TEMPERATURES TO THE AREA FOR LATER IN THE WEEK
AS WELL AS  MOISTURE...WITH DEW POINTS REACHING THE LOW TO MID 50S
FOR THURSDAY AND FRIDAY.  INCREASED MOISTURE IN THE AREA COULD
PROVIDE CHANCES FOR SCATTERED RAIN SHOWERS FRIDAY INTO SATURDAY.

SCATTERED RAIN SHOWERS WILL EXIST FOR TUESDAY WITH COOLER
TEMPERATURES IN THE MID 60S.  HIGH PRESSURE WILL MOVE IN WEDNESDAY
FOR SUNNY WEATHER AND LOW PRECIPITATION CHANCES.  A WARM FRONT MOVES
INTO THE REGION FOR THURSDAY AND FRIDAY...PROVIDING CHANCES FOR RAIN
SHOWERS LATE IN THE WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 547 AM MDT SAT MAY 18 2013

IFR TO MVFR CIGS WILL GRADUALLY LIFT FROM WEST TO EAST THIS
MORNING AS SFC TROUGH BEGINS TO DEVELOP ACROSS EASTERN COLORADO.
WARM TEMPS ALOFT SHOULD LIMIT THUNDERSTORM DEVELOPMENT THROUGH 19Z
BEFORE STORMS BEGIN TO DEVELOP ALONG SLOWLY ADVANCING DRY LINE.
CONFIDENCE IS LOW IN EXACT PLACEMENT OF THIS FEATURE WITH SO WILL
CONTINUE A GENERAL VCTS UNTIL POSITION BECOMES BETTER ESTABLISHED.
OTHERWISE...THERE IS A SMALL THREAT FOR LOW CIGS TONIGHT AFTER
COLD FRONT MOVES ACROSS AREA BUT WITH THUNDERSTORMS PLAYING A
LARGE ROLE IN FORECAST CONFIDENCE TOO LOW TO INCLUDE AT THIS POINT.

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&

$$

SHORT TERM...JRM
LONG TERM...JRM/MCK
AVIATION...JRM