000
FXUS64 KAMA 132009
AFDAMA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AMARILLO TX
309 PM CDT THU JUN 13 2013

.DISCUSSION...
THUNDERSTORM CHANCES FRIDAY THROUGH EARLY NEXT WEEK PRESENT THE MAIN
FORECAST CHALLENGE.

AN UPPER RIDGE REMAINS IN PLACE ACROSS THE CENTRAL CONUS THIS
AFTERNOON...FLANKED BY UPPER TROUGHS TO THE WEST AND EAST. A
SHORTWAVE THAT WILL BECOME A PLAYER FOR THE AREA FRIDAY AND SATURDAY
WAS SLOWLY MAKING ITS WAY NORTH INTO THE BIG BEND REGION. STILL
UNDER THE DOMINANCE OF THE UPPER RIDGE...WARM AND DRY CONDITIONS
PERSIST ACROSS THE PANHANDLES. SOUTH WINDS HAVE INCREASED TO 15-20
MPH WITH HIGHER GUSTS IN THE GRADIENT REGION BETWEEN A LEE TROUGH TO
THE WEST AND SURFACE RIDGE OVER THE EASTERN PLAINS/MS
VALLEY...HELPING TEMPERATURES RISE INTO THE 90S.

QUIET WEATHER WILL CONTINUE TONIGHT. ANTICYCLONIC FLOW AROUND THE
UPPER RIDGE WILL STEER CURRENT CONVECTION OVER THE HIGHER TERRAIN OF
CO AND NM TO THE NORTHEAST...KEEPING IT OUT OF THE PANHANDLES. LOWS
WILL FALL INTO THE MID 60S TO LOWER 70S TONIGHT.

THE UPPER RIDGE WILL SHIFT EAST ON FRIDAY AS AN UPPER TROUGH TRACKS
OUT OF THE NORTHERN ROCKIES INTO THE NORTHERN HIGH PLAINS...WHICH
WILL ALLOW THE BIG BEND SHORTWAVE TO DRIFT NORTH/NORTHEAST ACROSS
WEST TX. THERE IS STILL SOME UNCERTAINTY WITH THE SPEED AND TRACK OF
THIS WAVE /PARTICULARLY HOW FAR WEST OR EAST IT TRACKS/...WHICH
ISN/T SURPRISING GIVEN THE WEAK FLOW ALOFT. HOWEVER...THE GENERAL
CONSENSUS SUGGESTS IT WILL APPROACH THE SOUTHERN TX PANHANDLE FRIDAY
AFTERNOON...THEN DRIFT NORTHEAST ACROSS THE FORECAST AREA FRIDAY
NIGHT...MOVING INTO WESTERN OK SATURDAY AFTERNOON. COULD SEE SOME
ISOLATED SHOWERS AND THUNDERSTORMS FRIDAY AFTERNOON ACROSS THE
SOUTHERN TX PANHANDLE AS DAYTIME HEATING ACTS WITH LOWERING HEIGHTS
ALOFT AND INCREASING MOISTURE ACCOMPANYING THE WAVE TO DESTABILIZE
THINGS AND TRIGGER SOME ISOLATED CONVECTION. THESE SHOWER/THUNDERSTORM
CHANCES WILL CONTINUE INTO FRIDAY NIGHT AND EXPAND NORTHEAST AS THE
WAVE DRIFTS ACROSS. LOSS OF DAYTIME HEATING MAY BE OFFSET BY AT LEAST
A WEAK LLJ OVERNIGHT TO KEEP PRECIP CHANCES GOING. NOT EXPECTING ANY
SEVERE WEATHER DURING THIS TIMEFRAME AS CAPES LOOK TO MAX OUT AROUND
1000 J/KG...WHILE DEEP LAYER SHEAR REMAINS VERY WEAK AT 20 KTS OR
LESS. CAN/T RULE OUT A COUPLE STRONG STORMS WITH SMALL HAIL AND GUSTY
WINDS...BUT EVEN THIS THREAT LOOKS TO BE LIMITED BY WARM TEMPS ALOFT
WHICH WILL MINIMIZE THE HAIL THREAT...AND A MOISTENING AIRMASS WHICH
WILL PREVENT AN APPRECIABLE WIND GUST THREAT /FROM HIGH-BASED
STORMS/. PRECIPITABLE WATERS INCREASE TO 1 TO 1.5 INCHES FRIDAY AND
FRIDAY NIGHT AS THE SHORTWAVE MOVES IN...AND A LITTLE OVER 1.5 INCHES
ACROSS THE EASTERN PANHANDLES SATURDAY. THUS COULD SEE SOME LOCALLY
HEAVY RAIN AS STORM MOTIONS WILL BE FAIRLY SLOW...BUT OVERALL THINK
THE BETTER THREAT FOR HEAVY RAIN WILL REMAIN SOUTH/SOUTHEAST OF THE
PANHANDLES.

PRECIP CHANCES ON SATURDAY ASSOCIATED WITH THIS SHORTWAVE LOOK TO BE
FOCUSED ACROSS THE EASTERN PANHANDLES...AND WILL BE DEPENDENT ON HOW
FAST THE WAVE SHIFTS EASTWARD INTO OK. THESE STORM CHANCES MAY VERY WELL
SLIP EAST OF THE CWA BY EVENING...HOWEVER WE COULD SEE SOME
CONVECTION MOVE OUT OF THE HIGHER TERRAIN OF CO AND NM INTO THE
WESTERN PANHANDLES DURING THE EVENING. INSTABILITY AND SHEAR INCREASE
A LITTLE ON SATURDAY /MLCAPES 1000-1500 J/KG AND DEEP LAYER SHEAR
20-30 KTS/...SUPPORTING A LITTLE BETTER THREAT FOR STRONG CONVECTION
AND PERHAPS A COUPLE OF MARGINALLY SEVERE STORMS. EARLY DAY CLOUD
COVER/PRECIPITATION WILL KEEP INSTABILITY DOWN ACROSS THE EAST...SO
THE BETTER THREAT FOR ANY STRONGER STORMS WILL LIKELY COME WITH THE
LATE DAY CONVECTION MOVING IN FROM THE WEST.

THE UPPER RIDGE REMAINS SUPPRESSED ON SUNDAY AS AN UPPER LOW MOVES
ACROSS THE NORTHERN PLAINS/UPPER MIDWEST. AS THIS LOW CONTINUES TO
DROP SOUTHEAST ACROSS THE UPPER MIDWEST/GREAT LAKES SUNDAY
NIGHT...IT WILL PUSH A COLD FRONT SOUTH INTO THE PANHANDLES. THE
ARRIVAL OF THE FRONT...AND PERHAPS A WEAK SHORTWAVE ROUNDING THE
RIDGE...WILL BRING ANOTHER CHANCE FOR THUNDERSTORMS TO THE NORTHEAST
HALF OF THE AREA BY SUNDAY EVENING.

A LOW-LEVEL UPSLOPE REGIME WILL SET UP FOR MONDAY AND TUESDAY IN
WAKE OF THE FRONT...WHILE WEAK RIDGING/QUASI-ZONAL FLOW PREVAILS
ALOFT. GIVEN AN ABSENCE OF STRONGER RIDGING/CAPPING ALOFT...EXPECT
CONVECTION TO DEVELOP IN THE LOW-LEVEL UPSLOPE FLOW AND PROPAGATE
EASTWARD WITH TIME. EARLY INDICATIONS SUGGEST SOME DECENT RAIN
CHANCES FOR THE AREA. THE SEVERE WEATHER POTENTIAL WILL ALSO GO UP
DURING THIS TIME AS SHEAR AND INSTABILITY INCREASE.

THE UPPER RIDGE LOOKS TO AMPLIFY BY WEDNESDAY...THEN PERHAPS SHIFT A
LITTLE EASTWARD BY THURSDAY AS AN UPPER TROUGH WORKS ACROSS THE PAC
NW...LEADING TO A SOUTHWEST FLOW ALOFT. THIS WILL DECREASE
THUNDERSTORM CHANCES BY WEDNESDAY AND THURSDAY. CANNOT TOTALLY RULE
OUT SOME ISOLATED DIURNAL CONVECTION GIVEN A DIFFUSE DRYLINE
POTENTIALLY ACROSS EASTERN NM OR THE WESTERN PANHANDLES...ESPECIALLY
IF A WEAK DISTURBANCE RIDES THROUGH THE SOUTHWEST FLOW ALOFT.
HOWEVER...CAPPING WILL BE QUITE STRONG AS HEIGHTS/TEMPS RISE
ALOFT...SO WILL MAINTAIN A DRY FORECAST. TEMPERATURES WILL ALSO BE ON
THE RISE BY MID NEXT WEEK...FOLLOWING SOME COOLING /RELATIVELY
SPEAKING/ THIS WEEKEND AND EARLY NEXT WEEK...FIRST WITH THE
SHORTWAVE MOVING ACROSS AND THEN THE COLD FRONTAL PASSAGE.

KB

&&

.FIRE WEATHER...
NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED THROUGH
MID NEXT WEEK. MINIMUM RELATIVE HUMIDITIES MAY DIP JUST BELOW 20
PERCENT ACROSS PORTIONS OF THE WEST SOME AFTERNOONS...BUT MARGINAL
WINDS ALONG WITH RECENT RAINFALL...GREEN UP...AND A LACK OF FUEL
LOADING WILL MINIMIZE FIRE CONCERNS.

KB

&&

.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX                67  89  65  90  68 /   0   5  20  20  10
BEAVER OK                  69  97  68  93  69 /   0   5  10  30  20
BOISE CITY OK              66  93  62  91  67 /   5   5  10  20  20
BORGER TX                  72  93  70  93  72 /   0   5  20  20  10
BOYS RANCH TX              67  92  64  94  69 /   0   5  20  10  10
CANYON TX                  66  89  65  90  67 /   0  10  20  20  10
CLARENDON TX               68  92  69  87  71 /   0   5  20  30   5
DALHART TX                 64  91  62  93  65 /   0   5  10  10  20
GUYMON OK                  68  96  66  93  67 /   0   5  10  20  20
HEREFORD TX                64  89  64  89  65 /   0  20  20  10  10
LIPSCOMB TX                69  94  69  90  70 /   0   5  20  30  10
PAMPA TX                   68  92  68  90  69 /   0   5  20  30   5
SHAMROCK TX                70  94  70  89  71 /   0   5  20  40  10
WELLINGTON TX              70  95  71  91  72 /   0   5  20  40   5

&&

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

&&

$$

07/08