000
FXUS64 KLUB 030550
AFDLUB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
1150 PM CST MON MAR 2 2015

.UPDATE...
ISSUED A DENSE FOG ADVISORY FOR AREAS ON THE CAPROCK THROUGH 14Z
TUESDAY. MOST SHORT RANGE SOLUTIONS ARE NOW MAINTAINING SHALLOW
MOIST AIRMASS WITH WIDESPREAD VISIBILITY RESTRICTIONS ON THE
CAPROCK THROUGH ABOUT 14Z. WITH VEERING LOW LEVEL FLOW...AND
PERHAPS A BIT OF MIXING OVERNIGHT WITH PASSING SHOWERS ALOFT
MAINLY NEAR NEW MEXICO BORDER...POSSIBLE THAT ADVISORY MAY BE
TRIMMED EARLIER. AT LEAST TEMPERATURES HAVE BARELY CLIMBED ABOVE
FREEZING MOST AREAS ON THE CAPROCK...ALTHOUGH REMAINS A CLOSE
CALL INTO EARLY TUESDAY MORNING FOR ADDITIONAL RIME ICE
POTENTIAL. RMCQUEEN

&&

.AVIATION...
LOW IFR CONDITIONS HAVE PERSISTED AT BOTH KLBB AND KPVW THROUGH
THE EVENING...AND NOW MOST SOLUTIONS MAINTAIN NEAR OR BELOW IFR
UNTIL 12Z-14Z TIME-FRAME. KCDS REMAINS MORE MIXED WITH LOW CEILING
RISK BUT CHOSE TO MORE OR LESS MAINTAIN CURRENT CONDITIONS THERE
UNTIL THESE CHANGE...MOST LIKELY NEAR IF NOT A LITTLE BEFORE
DAYBREAK TUESDAY. IFR EXPECTED AFTERWARDS AT ALL SITES WITH VEERED
WEST TO SOUTHWEST LOW LEVEL FLOW. PASSING SHOWERS MAY YET BE AN
ISSUE TUESDAY BUT NOT POSSIBLE YET TO NAIL DOWN ANY MEANINGFUL
BEST CHANCE TIMES. RMCQUEEN

&&

.PREV DISCUSSION... /ISSUED 602 PM CST MON MAR 2 2015/

AVIATION...
HIGHLY COMPLEX ISSUES CONTINUE INVOLVING MAINTENANCE OF THE VERY
SHALLOW BUT COLD AND MOIST SURFACE CONDITIONS THIS EVENING. LOW
LEVEL SOUTHERLY FLOW HAS DEVELOPED BUT SERVING MAINLY TO RETAIN
HIGH MOISTURE FLOW FROM THE SOUTH. RADAR THIS EVENING ALSO IS
GIVING CLUES TO A CHANGING AIRMASS WITH A MASS OF VERY LOW
INTENSITY SHALLOW REFLECTIVITY NOT MORE THAN ABOUT -10 DBZ EDGING
INTO KLBB OVER THE NEXT COUPLE HOURS. SUSPECT A LAYER OF MORE
CONCENTRATED NEAR SURFACE SATURATION...PERHAPS DENSE FOG...BUT
SURFACE REPORTS SO FAR TO THE CONTRARY. MEANWHILE ALOFT...AN
UPPER IMPULSE WILL SPREAD LIFT IN FROM THE SOUTHWEST EARLY THIS
EVENING BUT MID LEVEL APPEARS VERY DRY. RADAR SHOWER ACTIVITY HAS
DEVELOPED JUST TO OUR SOUTH AND SOUTHWEST WHILE MAJORITY OF
SOLUTIONS SIDE WITH INABILITY OF THE PRECIPITATION TO SURVIVE
DECENT THROUGH THE VERY DRY LAYER BETWEEN 700 MB AND ABOUT 825 MB.
SHORT TERM SOLUTIONS WHICH HAVE NOT CUED INTO THIS ACTIVITY MUCH
PREVIOUSLY NOW ARE A BIT MORE SUPPORTIVE MOVING SHOWERS MAINLY
JUST NORTH AND WEST OF KLBB AND PERHAPS BRUSHING KPVW LATER
TONIGHT. WE WILL LEAVE SHOWERS OUT FOR NOW. VERY SHALLOW BUT QUITE
STRONG THERMAL INVERSION NEAR THE SURFACE APPEARS WILL CONTINUE TO
ERODE AT THE FACE OF THIS PERSISTENT LOW LEVEL SOUTHERLY VEERING
TO SOUTHWEST FLOW OVERNIGHT...BUT EVEN BY EARLY TUESDAY MORNING
SOLUTIONS SHOW MAINTENANCE OF A SHARP INVERSION. AND WITH SURFACE
TEMPERATURES REMAINING RIGHT NEAR FREEZING...THIS COULD FACTOR YET
INTO A MIXED PRECIPITATION TYPE SHOULD ANY EVENTUALLY THREATEN A
TAF SITE. CONFIDENCE IN FULL EROSION TIME THEREFORE REMAINS LOW
BUT WE WILL TIME TAFS FOR IMPROVEMENT IN THE LIFR CONDITIONS AT
KPVW AND KLBB BY MID TO LATE THIS EVENING WITH UNDERSTANDING THAT
SOLUTIONS ARE HAVING CONSIDERABLE DIFFICULTY WITH THIS EVENT. KCDS
APPEARS MORE LIKELY TO REMAIN MVFR CEILINGS MEANWHILE. MORE LIFT
WILL PASS BY TUESDAY IN SOUTHWEST FLOW ALOFT...WILL ATTEMPT TO
ADDRESS THAT MORE WITH THE 06Z TAF. WATCH FOR AMENDMENTS
THROUGHOUT THE NIGHT. RMCQUEEN

PREV DISCUSSION... /ISSUED 341 PM CST MON MAR 2 2015/

SHORT TERM...
MOST OF THE FORECAST AREA HAS REMAINED SHROUDED IN LOW CLOUDS AND
FOG TODAY...WITH TEMPERATURES STRUGGLING TO RISE INTO THE LOWER 30S.
THERE HAS BEEN SOME PARTIAL THINNING OF THE CLOUD COVER ACROSS THE
SE TX PANHANDLE AND NRN ROLLING PLAINS...AND TEMPERATURES IN THOSE
AREAS HAVE RISEN INTO THE UPPER 30S.

FOR TONIGHT...WE EXPECT TEMPS TO STAY FAIRLY FLAT AS THE WARM AIR
ADVECTION PATTERN CONTINUES...IN FACT WE MAY SEE TEMPS RISE A FEW
DEGREES IN SOME AREAS...WHICH WILL MAKE FIGURING OUT THE DAILY HIGH
AND LOW TEMPERATURE CHART COMPLICATED. THE MAJORITY OF GUIDANCE IS
NOT PARTICULARLY BULLISH TONIGHT REGARDING PRECIP CHANCES OR THE
POTENTIAL FOR DENSE FOG. THE DENSE FOG POTENTIAL WILL BE MITIGATED
BY VEERING SURFACE WINDS THAT ARE EXPECTED TO REMAIN IN THE 10 TO 15
MPH RANGE TONIGHT. WE HAVE INDICATED AREAS OF FOG IN THE GRIDS...AND
WILL MONITOR THE TRENDS THIS EVENING. AS FOR PRECIP CHANCES...WATER
VAPOR IMAGERY SHOWS THE UPPER LOW OFF THE SOCAL COAST SLOWLY MOVING
EASTWARD...WHILE A PLUME OF SUB-TROPICAL MOISTURE ALOFT STREAMS
ACROSS NRN MX NEWD INTO THE SRN HIGH PLAINS. OVERNIGHT...A NARROW
MID-LVL JET MAX WILL ADVANCE ACROSS THE REGION...AND ENHANCE THE
ONGOING WEAK ISENTROPIC LIFT. HOWEVER...FORECAST MOISTURE PROFILES
SHOW A PRONOUNCED MID-LVL DRY LAYER. THIS SHOULD LIMIT HOW MUCH
MOISTURE REACHES THE GROUND...BUT WE THINK THERE MAY BE SOME LIGHT
SHOWERS OF RAIN...PERHAPS MIXED WITH SNOW...OVERNIGHT...MAINLY
ACROSS FAR SRN TX PANHANDLE AND WRN SPLNS. ONLY TRACE ACCUMULATIONS
ARE EXPECTED.

AFTER A CLOUDY AND POSSIBLY FOGGY START TUESDAY MORNING A SURFACE
TROUGH WITH DRY WEST WINDS WILL SPREAD ACROSS THE AREA. THE TTU-WRF
SUGGESTS WE COULD STILL SEE SOME RAIN SHOWERS ACROSS THE NORTH AND
EAST AS THE MID-LVL VORT RIBBON SHIFTS NEWD...BUT WITH LOW-LVLS
CONTINUING TO DRY OUT WE THINK VIRGA IS MORE LIKELY. ALTHOUGH THERE
WILL STILL BE CONSIDERABLE MID AND HIGH-LEVEL CLOUD COVER THE
DOWNSLOPING BREEZES AND EROSION OF THE LOW CLOUDS SHOULD ALLOW
TEMPERATURES TO CLIMB INTO THE 50S AND 60S. WE HAVE UNDERCUT THE
GUIDANCE TEMP FORECAST BY 5-10 DEGREES PARTLY BECAUSE IT APPEARS
MUCH OF THE ENERGY WILL GO INTO MELTING THE REMAINING SNOWPACK.

LONG TERM...
OVERNIGHT TUESDAY INTO WEDNESDAY BRINGS ANOTHER COLD FRONT AND
UNSEASONABLY COLD TEMPS THROUGH THE TEXAS PANHANDLE AND
SOUTHERN/ROLLING PLAINS. YET ANOTHER UNUSUALLY COLD AIRMASS FILLS IN
BEHIND THE FRONT FOR WEDNESDAY AND THURSDAY BEFORE MODERATING
SOMEWHAT FRIDAY AND GRADUALLY WARMING THROUGH THE WEEKEND BACK
TOWARD MORE NORMAL TEMPERATURES FOR THIS TIME OF YEAR. HIGH TEMPS ON
WEDNESDAY WILL BE 25-35 DEGREES COOLER THEN NORMAL ACROSS THE REGION
WITH THE OVERNIGHT LOWS BOTTOMING OUT IN THE TEENS THURSDAY MORNING.

ALONG WITH THE COLD TEMPERATURES WE WILL ALSO BE DEALING WITH MORE
WINTRY PRECIPITATION LATE TUESDAY NIGHT THROUGH EARLY THURSDAY
MORNING. WITH THE BRIEF WARMUP TUESDAY ANY PRECIPITATION THAT DOES
DEVELOP WILL BEGIN IN THE FORM OF RAIN OUT AHEAD OF THE ADVANCING
COLD FRONT TO THE NORTH. WEAK ISENTROPIC LIFT OVER PERSISTENT LOW
LEVEL MOISTURE LATE TUESDAY NIGHT WILL RESULT IN RAIN AT FIRST THEN
CHANGING OVER TO A LIGHT WINTRY MIX BY SUNRISE WEDNESDAY...FURTHER
COMPLICATING THE FORECAST BEYOND JUST PRECIP PHASE IS THE SHORT TERM
GUIDANCE DRIES THE AREA OUT LATE TUESDAY INTO WEDNESDAY HOLDING BACK
BEST CHANCES FOR PRECIP WITH AND BEHIND THE FRONT ARRIVING WEDNESDAY
AFTERNOON...AS A COMPROMISE SCALED BACK SUPERBLEND POPS TO MOSTLY
SLIGHT CHANCE EARLY WEDNESDAY AND THEN FOLLOWED SUPERBLEND GUIDANCE
WITH CHANCE POPS LATER WEDNESDAY AS THE COLD FRONT ARRIVES.

OVERALL THE SYSTEMS BEST CHANCE FOR ANY ACCUMULATING SNOW WOULD BE
LATE WEDNESDAY NIGHT WITH NOT MUCH MORE THAN AN INCH OF ACCUMULATED
SNOW EXPECTED MAYBE SOME ISOLATED SPOTS WITH TWO INCHES IN OUR
NORTHERN ZONES WHERE TEMPERATURES DROP SOONER. IMPACTS WILL BE
MINIMAL WITH THE EXCEPTION OF FEELING LIKE THE HEART OF WINTER YET
AGAIN FOR A COUPLE OF DAYS DESPITE US ENTERING THE FIRST WEEK OF
METEOROLOGICAL SPRING.

BY FRIDAY THE SURFACE WINDS BECOME WESTERLY AS THE UPPER LEVEL
TROUGH MOVES EAST AND WE SEE TEMPERATURES GRADUALLY WARM THROUGH THE
WEEKEND AND REMAIN DRY THROUGH THE REST OF THE EXTENDED PERIOD.

&&

.PRELIMINARY POINT TEMPS/POPS...
FRIONA        33  59  27  28 /  10  10  10  40
TULIA         34  59  26  28 /  10  10  20  40
PLAINVIEW     34  60  29  30 /  10  10  20  40
LEVELLAND     33  60  34  34 /  10  10  20  40
LUBBOCK       34  61  33  33 /  10  10  20  40
DENVER CITY   34  61  39  43 /  10  10  10  40
BROWNFIELD    33  61  38  38 /  10  10  20  40
CHILDRESS     36  64  29  30 /  10  10  30  40
SPUR          35  63  33  33 /  10  10  30  40
ASPERMONT     36  67  37  37 /  10  10  30  50

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 8 AM CST TUESDAY FOR TXZ021>024-027>030-
033>036-039>042.

&&

$$

05/99/05