761  
FXUS64 KLUB 262321 AAA  
AFDLUB  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE LUBBOCK TX  
521 PM CST SUN FEB 26 2017  
   
AVIATION
 
 
VFR CONDITIONS THROUGH THE NEXT 24 HOURS. JORDAN  
 

 
   
PREV DISCUSSION
 
/ISSUED 335 PM CST SUN FEB 26 2017/  
 
SHORT TERM...  
MID AND UPPER LEVEL CLOUD COVERAGE HAS STEADILY INCREASED FROM THE  
WEST THROUGHOUT THE DAY WHILE SURFACE WINDS GRADUALLY BACKED FROM  
NORTHWEST TO SOUTHWEST ON THE CAPROCK AND HAVE REMAINED MOSTLY LIGHT  
AND VARIABLE OFF THE CAPROCK IN THE ROLLING PLAINS. OVERNIGHT LOWS  
TONIGHT WILL BE SIMILAR OR A TAD WARMER THAN LAST NIGHT WITH  
INCREASED CLOUD COVER AND SLIGHTLY HIGHER SURFACE DEW POINTS. COULD  
SEE SOME PATCHY FOG IN THE ROLLING PLAINS IN THE FEW HOURS  
SURROUNDING SUNRISE, WHERE THE WESTERN EDGE OF THE MUCH DEEPER GULF  
MOISTURE ADVECTING NORTH INTO CENTRAL PLAINS ENCROACHES OUR AREA. BY  
MIDDAY MONDAY TEMPERATURES WILL BE BACK ON THE RISE AS MODERATE  
SOUTHWEST SURFACE FLOW SPREADS ACROSS OUR CWA HELPING LIFT HIGHS  
INTO THE 70S FOR MOST OF US WITH OUR NORTHWEST ZONES IN UPPER 60S.  
 
LONG TERM...  
THE FULL-LATITUDE UPPER LEVEL TROUGH SWINGING ACROSS THE INTER-  
MOUNTAIN WEST MONDAY WILL EMERGE OVER THE HIGH PLAINS TUESDAY,  
PASSING EAST TUESDAY NIGHT. HEIGHT FIELDS AND SURFACE PRESSURE  
GRADIENTS WILL TIGHTEN TUESDAY, ESPECIALLY ACROSS THE SOUTHERN HIGH  
PLAINS. SOLUTIONS IN AGREEMENT AGAIN OF 90+ KNOTS OF FLOW AT THE 500  
MILLIBAR LEVEL TUESDAY AFTERNOON, WITH 50 TO 55 KNOTS OF FLOW MIXED  
OUT WITHIN THE 850 TO 700 MILLIBAR LAYER. STRONGEST WIND CORE SEEMS  
TO SHOW BEST FROM OUR SOUTHWEST ZONES THROUGH CENTRAL AND TOWARDS  
OUR NORTHEAST ZONES. GUIDANCE WINDS ALSO ARE HIGHER, NOW FROM 32 TO  
38 KNOTS AT LUBBOCK TUESDAY AFTERNOON. WE STILL ARE EXPECTING  
POSSIBLY A SIGNIFICANT PLUME OF HIGH CLOUDS TO SPREAD OVERHEAD, THAT  
MAY DELAY DEEPER MIXING SOMEWHAT, ALTHOUGH FORECAST SOUNDINGS ARE  
NOT INDICATING ANY SUCH PROBLEM WITH DEEP MIXING BY LATE MORNING OR  
MIDDAY ON TUESDAY.  
 
A SMALL AMOUNT OF CONVECTIVE POTENTIAL ENERGY WILL EXPAND EASTWARD  
LATE TUESDAY AND INTO THE EVENING FAVORING NORTHWEST ZONES. MID  
LEVELS MAY SATURATE WITH THE WAVE PASSAGE AND POSSIBLY GENERATE  
SHALLOW HIGH-BASED SHOWERS. WE HAVE ADDED SPRINKLES FOR OUR  
NORTHWEST COUNTIES. AND ELEVATED SHOWERS MAY ASSIST AS WELL IN  
DOWNWARD MOMENTUM TRANSFER OF THE STRONG WINDS ALOFT, THOUGH ALSO  
COULD INCREASE RELATIVE HUMIDITY A BIT ABOVE OUR CURRENT FORECAST.  
 
WE ARE ISSUING A HIGH WIND WATCH FOR TUESDAY, AND A CORRESPONDING  
FIRE WEATHER WATCH (SEE THE DISCUSSION ON THIS BELOW.)  
 
A COLD FRONT WILL FOLLOW LATE TUESDAY NIGHT AND SHOULD BE CLEARING  
MOST OF THE AREA BEFORE DAYBREAK WEDNESDAY. NORTHERLY BREEZES WILL  
BE STRONGEST WEDNESDAY ACROSS THE ROLLING PLAINS. TEMPERATURES  
WEDNESDAY WILL FALL A LITTLE BELOW NORMAL, AND WITH LIGHTER WINDS  
WEDNESDAY NIGHT SHOULD LEAD TO WIDESPREAD SUB- FREEZING READINGS  
AGAIN.  
 
THE NEXT ENERGY FROM THE EASTERN PACIFIC APPEARS WEAK AND WILL SPLIT  
AND DIP SOUTH INTO A WEAK SLOW-MOVING UPPER TROUGH CROSSING NORTHERN  
MEXICO OVER THE WEEKEND. WE WILL SEE DRY AND A GRADUAL WARMUP  
THURSDAY INTO SATURDAY WITH MODEST WINDSPEEDS. A STRONGER PACIFIC  
WAVE PASSING TO THE NORTH MAY INCREASE WIND AGAIN SUNDAY BEFORE A  
COLD FRONT EARLY MONDAY, BUT SOLUTIONS ARE INCONCLUSIVE ON HOW  
STRONG THE WAVE WILL BE AND WHETHER MAIN ENERGY WILL CROSS IN THE  
NORTHERN PLAINS OR THE CENTRAL PLAINS. MORE ON THIS LATER.  
RMCQUEEN  
 
FIRE WEATHER...  
FIRE WEATHER CONCERNS MAY BECOME ELEVATED ACROSS THE SOUTHERN SOUTH  
PLAINS BY MID-AFTERNOON TOMORROW. THE AIRMASS WILL BE DRY WITH MOST  
OF OUR AREA LOOKING AT RH VALUES IN THE TEENS FROM MID-AFTERNOON TO  
EARLY EVENING WITH MODERATE SOUTHWEST WINDS. HAVE DECIDED TO LET  
OVERNIGHT SHIFT REASSESS BEFORE ISSUING ANY PRODUCTS.  
 
FOR TUESDAY, A VERY STRONG DEEP LAYER OF WIND AND TIGHTENED  
HEIGHT GRADIENTS WILL SPREAD ACROSS THE AREA IN ADVANCE OF AN  
UPPER TROUGH EXPECTED TO PASS TUESDAY NIGHT. THIS SHOULD LEAD TO A  
VERY WINDY DAY, AND POSSIBLY WIND GUSTS APPROACHING 60 MPH FOR  
SOME AREAS. SOLUTIONS ALSO ARE INDICATING HIGH CLOUDS EARLY  
TUESDAY, AND THEN AN INCREASE IN MID LEVEL MOISTENING. WITH DEEP  
MIXING, THIS MAY LIMIT THE RELATIVE HUMIDITY DROP AND MAKE IT  
DIFFICULT TO REACH THE REQUIRED 15 PERCENT LEVEL FOR RED FLAG  
CONDITIONS. HOWEVER, RELATIVE HUMIDITY REMAINS THE TRICKIEST PART  
OF THIS FORECAST, DOWNSLOPE WINDS OFTEN LEAD TO LOWER HUMIDITY  
THAN EXPECTED, WHILE THE VERY STRONG WIND SPEEDS SEEM MORE  
CERTAIN. BASED MAINLY ON CONFIDENCE IN THE WINDS, WE ARE ISSUING A  
FIRE WEATHER WATCH TUESDAY FOR NEARLY THE ENTIRE AREA.  
 
ON WEDNESDAY, A COLD FRONT WILL PASS EARLY IN THE DAY WITH BREEZY  
NORTHERLY WINDS ACROSS THE ROLLING PLAINS. WITH VERY DRY FOLLOWING  
THE FRONT, IT'S NOT IMPOSSIBLE THAT WE WILL HAVE ELEVATED FIRE  
DANGER ON WEDNESDAY. RMCQUEEN  
 

 
   
LUB WATCHES/WARNINGS/ADVISORIES
 
 
FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING  
FOR TXZ021>043.  
 
HIGH WIND WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR  
TXZ021>025-027>031-033>036-039>042.  
 

 
 

 
 
14/93/14  
 
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