National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS64 KAMA 012316
AFDAMA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AMARILLO TX
516 PM CST SUN DEC 1 2013

.AVIATION...
00Z TAF CYCLE
A NORTHWEST TO WEST UPPER FLOW WILL ALLOW FOR SOME HIGH LEVEL CLOUDS
ACROSS THE THREE TAF SITES THROUGH 00Z TUESDAY...VFR CONDITIONS WILL
CONTINUE. A SURFACE TROUGH WILL MOVE INTO THE WESTERN PANHANDLES
MONDAY ALLOWING FOR LIGHT...5 TO 10 KNOT OR LESS...MAINLY WESTERLY
WINDS.

SCHNEIDER

&&

.PREV DISCUSSION... /ISSUED 324 PM CST SUN DEC 1 2013/

SHORT TERM...
THROUGH MONDAY: PLEASANT WEATHER WILL CONTINUE FOR ONE MORE DAY ON
MONDAY. A PRE FRONTAL TROUGH WILL DIG SOUTH ALONG THE EAST SIDE OF
THE ROCKIES. AS A RESULT...WINDS WILL SHIFT TO SOUTHWESTERLY BY
TOMORROW AFTERNOON. THIS DOWNSLOPING COMPONENT WILL BE ENOUGH TO
ALLOW TEMPERATURES TO BE ABOUT 5 TO 10 DEGREES HIGHER THAN TODAY.

LONG TERM...
TUESDAY-SUNDAY: AN ARCTIC AIR OUTBREAK THREATENS TO ENTRENCH UNSEASONABLY
COLD AIR OVER MUCH OF THE CENTRAL U.S. DURING SECOND HALF OF THIS WEEK.

A 1049 MB SURFACE HIGH WITH -35 DEGREE TEMPERATURES IS NOW CENTERED
OVER THE ALASKA/YUKON BORDER. AN ASSOCIATED BROAD UPPER AIR LOW WILL
DEEPEN OVER THE WESTERN STATES LATE MONDAY/EARLY TUESDAY IN THE WAKE
OF AN EJECTING SHORTWAVE TROUGH OVER THE NORTHERN PLAINS. THE INITIAL
WAVE WILL DISLODGE THE BITTERLY COLD AIRMASS OVER THE DIVIDE AND
SOUTHWARD ON THE PLAINS TUESDAY. QUESTIONS REMAIN AS TO HOW FAST THE
INITIAL SURGE WILL BE AND ITS TIMING LOCALLY...ESPECIALLY IN THE FACE
OF INCREASINGLY SOUTHWESTERLY MID LEVEL FLOW IN ADVANCE OF THE
DEEPENING U.S. TROUGH. HOWEVER...A NOTABLE COOLING TREND WAS SEEN IN
12Z MET MOS WHICH SIGNIFICANTLY COOLED EXPECTED DAYTIME HIGHS AT
GUYMON FROM 76 DEGREES ON THE PREVIOUS 00Z RUN...TO 47 DEGREES ON THE
CURRENT RUN. THIS TREND AS WELL AS BEHAVIOUR AND STEEPLY SLOPED
NATURE OF THE PREVIOUS ARCTIC AIRMASS WHICH PASSED 6-12 HOURS EARLIER
THAN PROGGED ON 21 NOVEMBER...LED US TO SIDE WITH FASTER SOLUTIONS.
CURRENTLY EXPECT FROPA OVER THE OKLAHOMA PANHANDLE AROUND 18Z TUE.
TUESDAY/S TEMPERATURE FORECASTS WILL BE PROBLEMATICALLY DICTATED BY
THE FRONT/S ADVANCE.

BEYOND TUESDAY...CONFIDENCE IS HIGH FOR A PROLONGED PERIOD OF COLD
WEATHER...INCLUDING PERSISTENTLY SUB-FREEZING TEMPERATURES THROUGH AT
LEAST SUNDAY. SHALLOW ISENTROPIC ASCENT OVER THE COLD FRONTAL LAYER
APPEARS WEAK AND INSUFFICIENT FOR MEANINGFUL PRECIPITATION UNTIL
WEDNESDAY NIGHT THROUGH THURSDAY. THAT/S WHEN DEEPER FORCING/ASCENT
SPILLS OVER THE PLAINS AS THE MEAN TROUGH AXIS TRANSLATES EAST TOWARD
THE FOUR CORNERS. PROGS INDICATE MAINLY WEAK ASCENT AND PRECIPITATION
RESULTING FROM ISENTROPIC PROCESSES...BUT ALSO DEPICT A 130 KT UPPER
AIR JET PROPAGATING OVER THE SOUTHERN PLAINS WHICH COULD ENHANCE LIFT
ENOUGH TO GENERATE AT LEAST LIGHT WINTRY ACCUMULATIONS. FORECAST PROFILES
FAVOR SNOW GIVEN THE DEEPLY COLD AIR IN PLACE BY THIS TIMEFRAME.

MEANINGFUL PRECIPITATION WILL LIKELY SUBSIDE AS THE PARENT TROUGH
EJECTS/MINORS OUT ON FRIDAY. MEDIUM RANGE SOLUTIONS...HOWEVER...HINT
THAT A SECOND ITERATION OF THE FOUR CORNERS TROUGH BECOMES RE-
ESTABLISHED ATOP THE ENTRENCHED COLD AIR DURING THE WEEKEND. THIS TOO
COULD RESULT IN LIGHT PRECIPITATION...POSSIBLY FAVORING FREEZING
DRIZZLE OR FLURRIES. THIS WILL BE MONITORED. OTHERWISE...THERE ARE
NO CLEAR SIGNALS THAT THE BITTERLY COLD AIMASS WILL BE DISLODGED FROM
THE HIGH PLAINS UNTIL AT LEAST SUNDAY.

FIRE WEATHER...
NO ELEVATED/CRITICAL FIRE WEATHER IS EXPECTED THROUGH MONDAY.
SOUTHWESTERLY WINDS MAY INCREASE TOWARDS 15 MPH BRIEFLY TUESDAY OVER
THE SOUTHWESTERN TEXAS PANHANDLE...AS HUMIDITY MINIMA FALL TO 15 TO
20 PERCENT. BELOW AVERAGE ERC VALUES REFLECT RECENT COOL/MOIST
CONDITIONS AND PRECLUDE ANY FIRE WEATHER CONCERNS. THEN...A PROLONGED
PERIOD OF COLD/MOIST CONDITIONS WILL CONTINUE TO MITIGATE FIRE
WEATHER MID WEEK THROUGH THE WEEKEND.

&&

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

&&

$$

11/08