Dense Fog in Texas, December 10, 2014

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE AMARILLO TX
1151 PM CST TUE DEC 9 2014

.AVIATION...
FOR THE 06Z TAFS...LOW CLOUDS CONTINUE TO BUILD NORTHWARD INTO THE
SOUTHERN TEXAS PANHANDLE...WHILE LOW CLOUDS AND FOG ARE DEVELOPING
ACROSS THE FAR EASTERN PANHANDLES. FEEL CONFIDENT THAT THESE SHOULD
EVENTUALLY OVERSPREAD THE TAF SITES OVER THE NEXT FEW HOURS...LEADING
TO IFR CEILINGS. VISIBILITY COULD BE REDUCED DUE TO BR...BUT DO NOT
THINK DENSE FOG WILL AFFECT THE TERMINALS BEFORE WEDNESDAY MORNING.
AT KAMA...EXPECT MVFR CEILINGS TO PERSIST AT LEAST THROUGH 18Z...BUT
COULD LINGER INTO THE AFTERNOON. AT KDHT AND KGUY...LOW CLOUDS ARE
LIKELY TO GIVE WAY TO VFR CONDITIONS BY LATE MORNING.

NF

&&

.PREV DISCUSSION... /ISSUED 550 PM CST TUE DEC 9 2014/

AVIATION...
00Z TAFS...VFR CONDITIONS THIS EVENING WILL GIVE WAY TO DETERIORATING
CONDITIONS OVERNIGHT AS WEAK BUT MOIST LOW-LEVEL SOUTHERLY FLOW IS
EXPECTED TO LEAD TO STRATUS AND FOG DEVELOPMENT. CIGS/VSBYS WILL
LIKELY DROP TO IFR/LIFR LEVELS AFTER 06Z...AND PERSIST INTO WEDNESDAY
MORNING. A WEAK WIND SHIFT TO THE NORTHWEST USHERING IN DRIER
AIR...ALONG WITH DAYTIME MIXING...WILL BRING IMPROVING CONDITIONS
FROM NORTHWEST TO SOUTHEAST MID TO LATE WEDNESDAY MORNING. KAMA WILL
LIKELY BE THE LAST TO SEE A RETURN TO VFR CONDITIONS...WHICH SHOULD
OCCUR AROUND 18Z.

KB

PREV DISCUSSION... /ISSUED 310 PM CST TUE DEC 9 2014/

DISCUSSION...

WATER VAPOR/RAP ANALYSIS SHOWS SHORTWAVE RIDGING OVER THE AREA THIS
AFTERNOON WITH THE NEXT SYSTEM TO AFFECT THE AREA LOCATED OVER
ARIZONA. THIS RELATIVELY WEAK SOUTHERN STREAM SHORTWAVE WILL RESULT
IN STRENGTHENING LEE TROUGH AND INCREASING SOUTHERLY MOIST LOW LEVEL
FLOW. LOW STRATUS AND FOG WILL LIKELY FORM AFTER MIDNIGHT AND PERSIST
THROUGH AT LEAST EARLY MORNING. BY AFTERNOON AT LEAST THE WESTERN
HALF OF THE OKLAHOMA AND TEXAS PANHANDLES SHOULD SEE PARTIAL
CLEARING. DRY MID LEVELS SHOULD PRECLUDE PRECIPITATION CHANCES
ALTHOUGH DEPTH OF THE MOIST LAYER MAY BE SUFFICIENT IN THE FAR
SOUTHEAST FOR SOME DRIZZLE. MEASURABLE PRECIPITATION APPEARS
UNLIKELY.

UPPER LEVEL RIDGING BUILDS IN BY LATE THURSDAY THROUGH AT LEAST EARLY
SATURDAY BEFORE HEIGHTS BEGIN TO FALL AHEAD OF APPROACHING UPPER
LEVEL TROUGH. PRECEDING THIS SYSTEM ON FRIDAY AND SATURDAY
TEMPERATURES SHOULD WARM TO THE UPPER 60S TO LOWER 70S WHICH IS ABOUT
20 DEGREES ABOVE NORMAL FOR DECEMBER.

MODELS HAVE NOT BEEN VERY CONSISTENT WITH HANDLING THE SYSTEM THAT
WILL IMPACT THE REGION BY THE LATTER PART OF THE WEEKEND INTO EARLY
NEXT WEEK. INITIAL CONCERNS ARE POTENTIAL FOR STRONG SOUTHERLY WINDS
AHEAD OF THE SYSTEM AS LEE TROUGH STRENGTHENS AND SURFACE PRESSURE
GRADIENT TIGHTENS SIGNIFICANTLY. 00Z RUNS SEEMED TO BE FURTHER NORTH
COMPARED TO THE 12Z RUNS WHICH HAVE SHIFTED THE TRACK OF THE CLOSED
LOW FURTHER SOUTH AGAIN. TRENDS YESTERDAY SUGGESTED A MORE
PROGRESSIVE/OPEN SYSTEM WITH PERHAPS A DRIER FORECAST. OPERATIONAL
GFS...ITS ENSEMBLES...AND ECMWF ARE ALL CLUSTERED FAIRLY CLOSE
TOGETHER NOW. GIVEN THE INHERENT NATURE OF THESE SOUTHERN STREAM
SYSTEMS...UNCERTAINTY REMAINS RATHER HIGH ON PRECIPITATION AMOUNTS
AND TYPE. THE 12Z GFS AND ECMWF HAVE INCREASED QPF CONSIDERABLY OVER
THE EASTERN PORTION OF THE AREA. WITH THE CURRENT INDICATED
TRACK...TEMPERATURES WOULD BE WARM ENOUGH FOR ALL RAIN EXCEPT IN THE
NORTHWEST HALF WHERE A CHANGE OVER TO SNOW WOULD BE POSSIBLE SUNDAY
NIGHT. PRECIPITATION MAY LINGER INTO EARLY MONDAY FOR AT LEAST THE
NORTHERN HALF. POST FRONTAL WINDS LATE SUNDAY INTO MONDAY MAY NEED TO
BE ADJUSTED UPWARD IN LATER FORECASTS.

BRB

&&

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

&&

06/11

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE AMARILLO TX
239 PM CST TUE DEC 9 2014

OKZ001>003-TXZ001>020-100845-
CIMARRON-TEXAS-BEAVER-DALLAM-SHERMAN-HANSFORD-OCHILTREE-LIPSCOMB-
HARTLEY-MOORE-HUTCHINSON-ROBERTS-HEMPHILL-OLDHAM-POTTER-CARSON-
GRAY-WHEELER-DEAF SMITH-RANDALL-ARMSTRONG-DONLEY-COLLINGSWORTH-
239 PM CST TUE DEC 9 2014

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE TEXAS AND OKLAHOMA
PANHANDLES.

.DAY ONE...TONIGHT.

AREAS OF FOG WILL DEVELOP AFTER MIDNIGHT AND MAY REDUCE VISIBILITIES
AT TIMES TO BELOW ONE MILE.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME.