Area Forecast Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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 KLUB 311151
AFDLUB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
651 AM CDT FRI JUL 31 2015

.AVIATION...
IFR/LIFR CEILINGS CURRENTLY PLAGUING KPVW AS LOW CLOUDS FILTER
SOUTH FROM TSRA TO THE NORTH ACROSS PARMER COUNTY AND FARTHER
NORTH INTO THE TEXAS PANHANDLE. COULD SEE SOME DEGRADATION AT
KLBB...BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE AT THIS TIME.
ISOLATED TO SCATTERED TSRA WILL DEVELOP THIS AFTERNOON INTO
TONIGHT...BUT AGAIN NOT ENOUGH CONFIDENCE IN PLACEMENT OF STORMS
TO INCLUDE IN ANY TAF. WILL ALSO HAVE TO WATCH LOW STRATUS/PATCHY
FOG POSSIBILITY LATE THIS EVENING AND TONIGHT DEPENDING ON
RAINFALL AND PLACEMENT OF ANY BOUNDARIES RESULTING FROM STORMS.

&&

.PREV DISCUSSION... /ISSUED 339 AM CDT FRI JUL 31 2015/

SHORT TERM...
UPPER RIDGE ACROSS WEST TEXAS WILL MOVE WESTWARD TODAY AS MOIST
UPSLOPE FLOW REMAINS IN PLACE LOCALLY. HOWEVER...DEEPER MOISTURE
PLUME ALOFT WILL FINALLY BE ABLE TO SINK SOUTH INTO THE SOUTH PLAINS
AND ROLLING PLAINS ALONG A DIFFUSE FRONTAL/REINFORCED OUTFLOW
BOUNDARY. THETA-E VALUES AND INSTABILITY WILL BE GREATEST WHERE THIS
RICHER MOISTURE...EVIDENCED BY PWATS OF UP TO 1.5 TIMES OF
NORMAL...RESIDES ACROSS THE FAR SOUTHEASTERN TEXAS PANHANDLE INTO
THE NORTHERN/CENTRAL ROLLING PLAINS. DESPITE THE PRESENCE OF
SCATTERED THUNDERSTORM ACTIVITY INCREASING WITH DAYTIME HEATING THIS
AFTERNOON...ANEMIC WIND FIELDS AND A STOUT SUBSIDENCE INVERSION
BELOW H50 WILL LIMIT UPDRAFT STRENGTH/ORGANIZATION AND ECHO TOP
HEIGHT. NONETHELESS...STEEP LOW LEVEL LAPSE RATES AND AN APPRECIABLE
AMOUNT OF SUB-CLOUD LAYER DRY AIR WILL PROMOTE ISOLATED DOWNBURST
WIND GUSTS. TEMPERATURES SHOULD ONCE AGAIN TOP OUT IN THE UPPER 80S
TO MID 90S FROM NORTH TO SOUTH ON THE CAPROCK AS LOCALES EAST OF THE
ESCARPMENT MAINLY HOLD IN THE MID-UPPER 90S AS INCREASED CLOUD
COVER/EVAPORATIVE COOLING PROCESSES KEEP READINGS JUST SHY OF THE
CENTURY MARK.

STORMS WILL CONTINUE INTO THIS EVENING AS MOISTURE CONTINUES TO
INCREASE THUS PROMOTING A BETTER POTENTIAL FOR LOCALIZED HEAVY
RAINFALL...MORE LIKELY IN THE ROLLING PLAINS IN CONJUNCTION WITH THE
GREATEST MOISTURE. BEST RAIN CHANCES AND WIDESPREAD FLOODING THREAT
WILL REMAIN NORTH OF THE FAR SOUTHERN PANHANDLE FARTHER FROM THE
INFLUENCE OF THE UPPER RIDGE AND NEARER THE RESIDUAL LOW-MID LEVEL
MOISTURE PLUME. SEASONABLE LOWS WILL BE IN THE OFFING RANGING FROM
THE MID 60S NORTHWEST TO LOW-MID 70S SOUTHEAST.

LONG TERM...
A WETTER FORECAST IS STILL EXPECTED INTO EARLY NEXT WEEK...HOWEVER
IT WILL ALL DEPEND ON THE PLACEMENT OF THE RIDGE. EACH MODEL HAS ITS
DIFFERENCES ON HOW THE RIDGE WILL MOVE WHICH IN TURN CREATES
DIFFERENCES WITH THE RAIN FORECAST. THE WETTEST MODELS IN THE NEAR
APPEAR THE BE THE NAM/GFS ESPECIALLY WITH SATURDAY
AFTERNOON/EVENING. QPF AMOUNTS NEAR AND OVER AN INCH ARE FORECASTED
BY THE TWO ACROSS THE ROLLING PLAINS WITH THE NAM HAVING THE HIGHER
AMOUNTS. SOME OF THIS APPEARS TO BE CONVECTIVE FEEDBACK IN THE
MODELS BUT IT ALSO SEEMS THAT THEY ARE PICKING UP ON AN OUTFLOW
BOUNDARY FROM CONVECTION EARLIER SATURDAY MORNING AND USE THAT TO
SUSTAIN AND DEVELOP CONVECTION INTO THE AFTERNOON AND EVENING.
SUSTAINABILITY IS AIDED WITH THE RIDGE BEING PLACED TO OUR WEST
WITH SEVERAL WEAKNESSES ROTATING AROUND THE RIDGE. WHILE IT IS HARD
TO DETERMINE IF THE OUTFLOW WILL HAPPEN IN A WAY DEPICTED BY THE NAM
AND GFS HIGH END CHANCE POPS WILL BE KEPT ACROSS THE ROLLING PLAINS
AS THE ECMWF HAS BEEN SHOWING HINTS OF CONVECTION DEVELOPING IN THAT
REGION LATER SATURDAY AND SEEMS PLAUSIBLE GIVEN UPSLOPE FLOW AT THE
SURFACE AND NORTHWESTERLY FLOW ALOFT.

THE GFS/ECMWF SOMEWHAT DISAGREE WITH THE HANDLING OF THE RIDGE EARLY
TO MID NEXT WEEK. THE ECMWF WANTS TO KEEP THE RIDGE JUST TO OUR WEST
WHICH WOULD FAVOR A WETTER PATTERN. THE GFS WANTS TO BUILD THE RIDGE
BACK EAST AND CENTER IT OVER TEXAS THUS FAVORING A DRIER FORECAST.
WITH BOTH MODELS BUILDING A TROF OF THE WEST COAST GIVES WAY TO
THINK THAT THE RIDGE WILL BE PUSHED A BIT FURTHER EAST THAN
FORECASTED BY THE ECMWF. TEMPERATURES WILL WARM SLIGHTLY IN RESPONSE
TO THE MOVING RIDGE BY MID WEEK TO THE LOW/MID 90S ON THE CAPROCK
AND UPPER 90S/100 ACROSS THE ROLLING PLAINS.

&&

.PRELIMINARY POINT TEMPS/POPS...
FRIONA        87  65  86  64 /  40  40  30  20
TULIA         88  66  83  65 /  40  40  40  30
PLAINVIEW     89  67  85  66 /  30  30  40  30
LEVELLAND     92  68  90  69 /  20  20  30  20
LUBBOCK       91  70  90  69 /  20  30  30  20
DENVER CITY   94  67  92  68 /  10  10  20  20
BROWNFIELD    93  69  92  70 /  10  10  30  20
CHILDRESS     94  72  86  70 /  30  30  50  40
SPUR          95  70  90  70 /  20  30  40  30
ASPERMONT     99  73  93  72 /  20  30  40  40

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

31



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