Area Forecast Discussion
Issued by NWS Amarillo, TX

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS64 KAMA 162155
AFDAMA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AMARILLO TX
355 PM CST TUE DEC 16 2014

.DISCUSSION...

PRIMARY FORECAST CHALLENGE IS TIMING OF INTERMITTENT LOW END
PRECIPITATION CHANCES THROUGH THE END OF THE WEEK AND OCCASIONAL
PERIODS OF FROZEN PRECIPITATION POTENTIAL.

ISENTROPIC ASCENT WILL STRENGTHEN OVERNIGHT AHEAD OF AN APPROACHING
SHORTWAVE PRIMARILY ACROSS THE SOUTHEASTERN PORTION OF THE TEXAS
PANHANDLE. PRIMARY IMPACT OVERNIGHT WILL BE INCREASING/LOWERING OF
CLOUDS AS SATURATION ON 290-300K ISENTROPIC SURFACES OCCURS BY
AROUND DAYBREAK AND CONTINUING THROUGH THE EARLY AFTERNOON HOURS.
OVERALL DEPTH OF SATURATED LAYER IS GREATER TO THE SOUTHEAST ACROSS
CENTRAL TEXAS INTO OKLAHOMA AND THIS WILL BE WHERE THE BEST
PRECIPITATION CHANCES WILL RESIDE. ONCE THE RELATIVELY DRY LOW LEVELS
SATURATE BY AROUND MID MORNING...RAIN SHOWERS WILL BECOME POSSIBLE
ACROSS MAINLY THE SOUTHEASTERN THIRD OF THE FORECAST AREA. THIS WILL
PERSIST INTO THE AFTERNOON AND GRADUALLY END FROM WEST TO EAST BY
EVENING. CONSISTENT WITH PREVIOUS FORECAST MAINTAINED A RELATIVELY
TIGHT TEMPERATURE GRADIENT FROM NORTHWEST TO SOUTHEAST DUE MAINLY TO
EVAPOARTIVE COOLING WITH PRECIPITATION IN THE SOUTHEAST. THE
PRECIPITATION FREE FAR WESTERN SECTIONS COULD POTENTIALLY WARM WELL
INTO THE 50S TOMORROW AFTERNOON.

LATE TOMORROW EVENING AND THROUGH THE NIGHT MOISTURE SEEMS TO BE
SHALLOW ENOUGH IN THE EAST FOR MOSTLY DRIZZLE IF ANY MEASURABLE
PRECIPITATION OCCURS AT ALL. KEPT POPS LOW AND LIMITED TO MAINLY THE
OKLAHOMA PANHANDLE AND THE FAR NORTHEAST TEXAS PANHANDLE. THE
EXCEPTION IS THE FAR WESTERN PORTION OF THE OKLAHOMA PANHANDLE NEAR
BOISE CITY WHERE ENOUGH MOISTURE DEPTH AND SATURATION IN THE
DENDRITIC GROWTH ZONE IS SHOWN IN GUIDANCE TO SUPPORT THE
POSSIBILITY OF SNOW BEFORE DEEPER MOISTURE SHIFTS NORTHEAST OF THE
AREA AS SHORTWAVE DEPARTS. TEMPERATURES SHOULD FALL TO AT OR BELOW
FREEZING FOR AT LEAST A PORTION OF THE AREA WHERE A SHALLOW MOIST
LAYER REMAINS LATER IN THE NIGHT AND THIS RAISES SOME CONCERN FOR
FREEZING DRIZZLE. THIS IS DEFINITELY THE MOST CHALLENGING PORTION OF
THE FORECAST. NOT REAL CONFIDENT IN THIS SCENARIO BUT HAVE INCLUDED
MENTION IN THE GRIDS FOR NOW. THIS WOULD BE LIMITED TO THE FAR
NORTHERN TEXAS PANHANDLE AND THE OKLAHOMA PANHANDLE IF IT OCCURRED.
ALTHOUGH CURRENT GUIDANCE SUGGESTS ENOUGH MOISTURE DEPTH FOR THE
POTENTIAL OF MEASURABLE PRECIPITATION...THIS MAY MANIFEST ITSELF AS
MORE OF A LOW CLOUD/FOG SCENARIO. ADJUSTMENTS MAY BE MADE PENDING
MODEL TRENDS WITH MOISTURE/LIFT IN SUBSEQUENT FORECASTS.

AN ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH THE END OF THE WEEK
AND INTO THE WEEKEND WITH A SERIES OF SHORTWAVES QUICKLY PROGRESSING
EAST ACROSS THE REGION. MEDIUM RANGE MODELS ARE IN REASONABLE
AGREEMENT WITH TIMING OF INDIVIDUAL WAVES IN THE PROGRESSIVE PATTERN
BUT DIFFER SOMEWHAT ON AMPLITUDE...PARTICULARLY WITH THE SHORTWAVE
THAT WILL MOVE THROUGH THIS WEEKEND. WEAK SHORTWAVE RIDGING IN THE
WAKE OF THE FIRST SHORTWAVE TROUGH WILL OCCUR THURSDAY. WILL NEED TO
MONITOR AMPLITUDE OF RIDGING AND POTENTIAL FOR WARMER TEMPERATURES
THURSDAY AFTERNOON. THE NEXT SHORTWAVE TROUGH AND PRECIPITATION
POTENTIAL WILL OCCUR LATE THURSDAY NIGHT THROUGH EARLY
FRIDAY...ALTHOUGH NEWEST ECMWF SUGGESTS PRECIPITATION CHANCES
LINGERING LATER ON FRIDAY. FOR NOW HAVE KEPT PRECIPITATION CHANCES IN
THE SLIGHT RANGE AND TRANSITIONED FROM RAIN TO RAIN/SNOW THROUGH
MORNING WITH NO PRECIPITATION MENTION BEYOND FRIDAY MORNING.

DESPITE UNCERTAINTIES WITH THE FINAL SHORTWAVE IN THIS FORECAST
PERIOD THAT WILL MOVE THROUGH THIS WEEKEND...DUE TO ITS POSITIVE TILT
AND CONFINEMENT OF DEEPEST MOISTURE JUST SOUTHEAST OF THE AREA...DID
NOT STRAY FROM THE CONSENSUS BLEND WHICH KEPT US DRY.

BRB

.PREV DISCUSSION... /ISSUED 1148 AM CST TUE DEC 16 2014/

AVIATION...
18Z TAF CYCLE
A SOUTHWESTERLY FLOW ALOFT WILL ALLOW FOR INCREASING MID AND HIGH
LEVEL CLOUDINESS THROUGH TONIGHT. AN APPROACHING UPPER LOW OVER THE
SOUTHWESTERN STATES TONIGHT AND WEDNESDAY WILL ALLOW FOR INCREASING
LOW CLOUDINESS BY 14Z TO 16Z WEDNESDAY. VFR CONDITIONS WILL PERSIST
THROUGH ABOUT 14Z TO 16Z WEDNESDAY...AND THEN MVFR CONDITIONS ARE
EXPECTED. SOUTHERLY WINDS 5 TO 15 KNOTS INCREASING TO 10 TO 20 KNOTS
AFTER 14Z TO 16Z WEDNESDAY.

SCHNEIDER

&&

.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX                33  45  33  47  30 /   5  20  10  10  20
BEAVER OK                  31  45  32  42  29 /   5  20  20  20  10
BOISE CITY OK              31  51  29  44  26 /   0  10  20  10  10
BORGER TX                  35  46  35  48  32 /   5  20  10  10  20
BOYS RANCH TX              31  53  31  49  29 /   5  10  10  10  20
CANYON TX                  34  48  33  49  30 /   5  20   5  10  20
CLARENDON TX               34  42  35  49  32 /  10  20  10  10  20
DALHART TX                 29  51  29  48  27 /   0  10  10  10  20
GUYMON OK                  33  50  31  44  29 /   5  10  20  20  10
HEREFORD TX                33  53  32  52  29 /   5  10   5  10  20
LIPSCOMB TX                33  41  34  43  31 /   5  20  20  20  20
PAMPA TX                   33  40  33  45  30 /   5  20  10  10  20
SHAMROCK TX                33  40  36  47  33 /  10  30  10  20  20
WELLINGTON TX              34  42  36  48  35 /  10  30  10  20  20

&&

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

&&

$$

17/11




USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.