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000
FXUS64 KAMA 151719
AFDAMA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AMARILLO TX
1219 PM CDT SAT JUN 15 2013

.AVIATION...
MORNING MVFR CEILINGS HAVE CONTINUED TO CLEAR OUT OF THE TERMINALS.
MAIN AVIATION CONCERNS FOR THIS TAF ISSUANCE WILL BE THE POSSIBILITY
OF THUNDERSTORMS NEAR THE TERMINALS AND THE REDEVELOPMENT OF LOW
CLOUDS TOMORROW MORNING.

MODELS STILL DEPICT THE CHANCE FOR CONVECTION TO DEVELOP OVER THE NEW
MEXICO MOUNTAINS THIS AFTERNOON/EVENING THEN MOVING INTO THE
PANHANDLES. SHOULD CONVECTION DEVELOP IT WILL BE AFTER 20Z AND COULD
LAST UNTIL 7-8Z. SHOULD ONE OF THESE STORMS MOVE OVER A TERMINAL
EXPECT CEILINGS AND/OR VISIBILITIES TO DROP TO MVFR/IFR FOR BRIEF
PERIODS. HOWEVER...CONFIDENCE ON OCCURRENCE AND TIMING REMAINS TOO LOW TO
PLACE THUNDER IN THE PREVAILING CONDITIONS SO WILL ISSUE UPDATES
SHOULD STORM APPROACH THE TERMINALS.

THE NEXT CONCERN IS THE POSSIBILITY OF LOW CLOUDS TOMORROW MORNING.
A COUPLE MODELS HINT AT ANOTHER STRATUS DECK DEVELOPING AROUND 9Z
FOR EACH TERMINAL. HAVE KEPT TERMINALS VFR FOR NOW...BUT LOWERED SCT
DECK TO HINT AT LOWER CEILINGS.

&&

.PREV DISCUSSION... /ISSUED 1015 AM CDT SAT JUN 15 2013/

UPDATE...
MADE MINOR UPDATES TO POPS AND HOURLY WEATHER GRIDS TO REFLECT
CURRENT TRENDS. SUBSIDENCE IS PROVING SUFFICIENT TO PREVENT
NORTHWESTWARD EXPANSION OF THE SHOWERS ACROSS WESTERN OKLAHOMA AND
NORTH CENTRAL TEXAS. FORECAST FOR THIS AFTERNOON REMAINS UNCHANGED.

PREV DISCUSSION... /ISSUED 649 AM CDT SAT JUN 15 2013/

AVIATION...
FOR THE 12Z TAFS...A BRIEF BOUT OF LOW CLOUDS IS OCCURRING AT
KGUY...WITH MORE SPOTTY COVERAGE AT KDHT AND KAMA. EXPECT ANY LOW
CLOUDS TO ERODE BY AROUND 15Z. TSTM DEVELOPMENT THIS AFTERNOON AND
TONIGHT IS NOT ALL THAT CLEAR CUT. SHORT RANGE AND MESOSCALE MODELS
ARE NOT IN AGREEMENT ON WHERE OR IF TSTMS WILL DEVELOP LATER THIS
AFTERNOON AND TONIGHT. IT DOES APPEAR THAT THE OK PNHDL AROUND KGUY
MAY HAVE THE GREATEST THREAT...FOLLOWED BY KDHT AND THEN KAMA LEAST
LIKELY IF AT ALL...BASED ON OVERALL UPPER LEVEL FLOW. HAVE OPTED NOT
TO MENTION TSTMS AT ANY TAF SITE FOR THIS FCST CYCLE DUE TO LOW
CONFIDENCE AT THIS TIME.

ANDRADE

PREV DISCUSSION... /ISSUED 349 AM CDT SAT JUN 15 2013/

DISCUSSION...
AN ACTIVE WEATHER PATTERN CONTINUES FOR THE NEXT FEW DAYS AS THE
RIDGE STRUGGLES TO BUILD BACK AS TROUGHS CONTINUE TO RIDE THE RIDGE.

TODAY AND TONIGHT...A FEW DIFFERENT CHANCES FOR STORMS TODAY AS THE
TROUGH CONTINUES TO LIFT NE OVER THE REGION. FIRST...SOME HIGH
RESOLUTION MODELS SHOW THE TROPICAL LIKE CONVECTION IN THE EASTERN
PANHANDLES REDEVELOPING BY MID MORNING. HAVE SOME DOUBTS ON THIS
GIVEN THE DISSIPATING TREND. HOWEVER...THE GFS DOES SHOW THE TROUGH
EITHER STALLING OR BRIEFLY RETROGRADING THIS MORNING...WHICH COULD
CONTRIBUTE TO REDEVELOPMENT. THE SECOND CHANCE FOR STORMS COMES THIS
AFTERNOON AS STORMS THAT DEVELOP IN THE HIGHER TERRAIN OF NM/CO COULD
DRIFT INTO THE FAR NW TX AND W OK PANHANDLES. THIS IS A SMALL CHANCE
AT BEST GIVEN THE WEAK MEAN FLOW. SUSPECT IF THIS DOES HAPPEN...IT
WILL BE A VERY BRIEF WINDOW OF OPPORTUNITY...BETWEEN 6 AND 9 PM CDT.
HOWEVER...IF IT OCCURS IT COULD ALSO POSE THE HIGHEST RISK FOR SEVERE
HAIL AND WINDS. THE BEST CHANCES FOR STORMS LOOK TO BE TONIGHT...IN
THE FORM OF AN MCS AT THE NOSE OF THE SOUTHERLY LOW LEVEL JET THAT IS
EXPECTED TO DEVELOP. AS COMPARED TO PREVIOUS RUNS AND OTHER
MODELS...THE GFS IS SHOWING THIS LLJ DEVELOPING MUCH FURTHER SOUTH
WHICH COULD MEAN THE MCS WOULD PRIMARILY BE IN THE PANHANDLES AS
OPPOSED TO THE ECMWF WHICH SHOWS IT MOSTLY IN KS...JUST GRAZING THE
OK PANHANDLE. GIVEN THE STILL ABOVE NORMAL PWATS...SLOW STORM
MOTIONS...AND NOCTURNAL LLJ...EXPECT THE PRIMARY HAZARD TO BE HEAVY
RAIN LEADING TO LOCALIZED FLOODING. HOWEVER...WITH ELEVATED
INSTABILITY...SOME MARGINALLY SEVERE HAIL COULD BE POSSIBLE TONIGHT.

SUNDAY AND SUNDAY NIGHT...RIDGE TRIES TO BUILD BACK DURING THE DAY.
THERE IS SOME CHANCE FOR STORMS SUNDAY AFTERNOON WITH A WEAKLY CAPPED
ENVIRONMENT AND CAPE VALUES NEAR OR ABOVE 1000 J/KG. HOWEVER...THERE
LACKS ANY LARGE SCALE FOCUS FOR LOW LEVEL CONVERGENCE...AT LEAST
UNTIL THE FRONT ARRIVES LATE SUNDAY NIGHT...AND WITH THE RIDGE
BUILDING EXPECT WIDE SPREAD SUBSIDENCE. THUS...THINK THE ONLY CHANCE
FOR AFTERNOON CONVECTION WILL BE IF THERE ARE ANY REMNANT OUTFLOW
BOUNDARIES FROM CONVECTION TONIGHT. AS MENTIONED BEFORE...THE LATE
NIGHT COLD FRONT ARRIVAL BRINGS LOW LEVEL CONVERGENCE AND A BETTER
CHANCE FOR PRECIPITATION. MUCH LIKE TODAY...THE PRIMARY HAZARD
REMAINS LOCALLY HEAVY RAIN AND IT APPEARS THAT IF THERE IS ANY
AFTERNOON CONVECTION...THERE IS A SMALL THREAT FOR LARGE HAIL AND
STRONG WINDS.

MONDAY THROUGH WEDNESDAY...THROUGH THIS PERIOD THE BIGGEST QUESTIONS
WILL BE HOW QUICKLY WILL THE RIDGE BUILD BACK AND WILL THE SUBSIDENCE
FROM THAT BE ENOUGH TO QUASH ANY THUNDERSTORM CHANCES ASSOCIATED WITH
THE PASSAGE OF UPPER LEVEL SHORT WAVE TROUGHS. GFS SHOWS THE HIGH
AMPLITUDE RIDGE IN PLACE BY TUESDAY...HOWEVER THE ECMWF DOESN/T COME
CLOSE TO SHOWING THIS ESTABLISHED AT THIS POINT. THUS...HAVE KEPT
SLIGHT CHANCE OF STORMS THROUGH WEDNESDAY.

THURSDAY THROUGH SATURDAY...COULD SEE A FEW MORE CHANCES OF STORMS
WITH THE CONTINUED PARADE OF UPPER LEVEL SHORT WAVE TROUGHS...THOUGH
CONFIDENCE IN THE MODEL SOLUTIONS THROUGH THIS PERIOD IS NOT VERY
HIGH AS THERE ARE SOME BIG DIFFERENCES BETWEEN THE GFS AND ECMWF ON
THE EVOLUTION AND LOCATION OF THE UPPER LEVEL RIDGE AND LATE WEEK
PACIFIC NW LOW. HAVE KEPT THIS PERIOD DRY FOR NOW.

JOHNSON

FIRE WEATHER...
RECENT RAINS AND GREEN UP...COMBINED WITH RELATIVE HUMIDITY VALUES
NEAR OR ABOVE 20 PERCENT WILL PRECLUDE ANY ELEVATED OR CRITICAL FIRE
WEATHER CONDITIONS FOR THE NEXT SEVERAL DAYS.

JOHNSON

&&

.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.

&&

$$

14/08