460
FXUS64 KLUB 221144
AFDLUB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
644 AM CDT WED MAY 22 2013
.AVIATION...
VFR EXPECTED WITH SLOWLY BUILDING RIDGE ALOFT...MODERATE SURFACE
LOW PRESSURE TROUGH...AND LOW LEVEL SOUTHERLY FLOW. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 453 AM CDT WED MAY 22 2013/
SHORT TERM...
UPPER LEVEL HEIGHTS WILL BUILD ACROSS THE AREA TODAY IN ADVANCE OF A
WEAK DISTURBANCE PULLING ACROSS THE CENTRAL ROCKIES. THIS WAVE WILL
ATTEMPT TO BREECH THE RIDGE ACROSS THE SOUTHERN PLAINS THIS EVENING
BUT SHOULD ENCOUNTER SUBSTANTIAL RESISTANCE TO THUNDERSTORM
DEVELOPMENT. THE MOST RECENT WRF/NAM SOLUTION HAS COME MUCH MORE
INTO LINE WITH THE GFS BUILDING A SUBSIDENCE CAPPING INVERSION
BETWEEN ABOUT 500 MB AND 600 MB LATE THIS AFTERNOON INTO THE
EVENING. AS THE WAVE PULLS THROUGH DURING THE EVENING WITH A 55KT
JET MAXIMUM AT H300 MB ACROSS THE AREA...A LOW LEVEL JET ALSO WILL
START TO DEVELOP ASSISTING IN PULLING MUCH BETTER MOISTURE AND
INSTABILITY NORTHWARD INTO EASTERN ZONES. HOWEVER GIVEN THE TREND
TOWARDS MORE CAPPING WE WILL RETAIN THE PREVIOUS DRY FORECAST
THROUGH TONIGHT. SIGNALS OF A POSSIBLE MCS DEVELOPING FROM NORTHWEST
OKLAHOMA SOUTHEASTWARD ARE STILL APPARENT VERY LATE TONIGHT...THOUGH
REMAIN JUST OUT OF OUR AREA. STILL...THIS MAY LEAD TO AN OUTFLOW
BOUNDARY OR AN INCREASE IN EAST OR SOUTHEAST WINDS FROM WESTERN
OKLAHOMA WESTWARD LATE TONIGHT OR EARLY THURSDAY. LITTLE
DISAGREEMENT WITH THE PREVIOUS TEMPERATURES AS WELL. RMCQUEEN
LONG TERM...
PROSPECTS CONTINUE TO BE LIKELY FOR SEVERE CONVECTION TO IMPACT
THE EXTREME SOUTHERN TEXAS PANHANDLE...SOUTH PLAINS...AND ROLLING
PLAINS THURSDAY AFTERNOON AND EVENING.
MID TO UPPER RIDGING WILL AMPLIFY OVER THE HEART OF THE
COUNTRY...EXTENDING FROM THE SOUTHERN PLAINS INTO CANADA. INCREASING
MOISTURE WILL BE IN PLACE OWING TO THE PREVIOUS NIGHT/S LOW LEVEL
JET USHERING RICHER GULF MOISTURE INTO THE AREA AS EVIDENCED BY
DEWPOINTS CLIMBING INTO THE UPPER 50S TO LOWER 60S AHEAD OF THE
DRYLINE...WHICH IS PROGGED TO MIX EAST SOMEWHERE IN VICINITY OF THE
EDGE OF THE CAPROCK DURING PEAK HEATING. A BACKDOOR FRONT WILL
APPROACH FROM THE CENTRAL/SOUTHERN GREAT PLAINS DURING THE
AFTERNOON...CREATING INCREASED LOW LEVEL CONVERGENCE AND HELICITY
ALONG THE DRYLINE/FRONT INTERFACE. INSTABILITY WILL BE PLENTIFUL
AHEAD OF THE DRYLINE AND LOOKS TO BE FURTHER ENHANCED BY A SHORTWAVE
TROUGH MOVING THROUGH THE RIDGE AND COOLING TEMPERATURES ALOFT. THE
TIMING OF THIS PERTURBATION WILL HAVE AN IMPACT ON SYNOPTIC FORCING
FOR ASCENT...PERHAPS COUPLING WITH THE RIGHT ENTRANCE REGION OF A
STRENGTHENING SUBTROPICAL JET. LOW LEVEL SPEED SHEAR WILL RECEIVE A
BOOST HEADING INTO THE EVENING AS A 30-40 KNOT LOW LEVEL JET
DEVELOPS AND LENGTHENS ALREADY CURVED HODOGRAPHS.
BELIEVE INITIATION WILL TAKE PLACE ACROSS THE EXTREME SOUTHERN
PANHANDLE INTO THE ADJACENT ROLLING PLAINS WHERE THE DRYLINE AND
BACKDOOR FRONT MEET BY MID AFTERNOON...BEFORE MOVING SOUTHWEST IN
CONJUNCTION WITH THE FRONT AND RETREATING DRYLINE INTO THE EVENING.
LARGE HAIL AND DAMAGING WIND GUSTS WILL BE THREATS AREAWIDE...WHILE
A CONDITIONAL TORNADO THREAT WILL EXIST BASED ON WHERE
HELICITY/DIRECTIONAL SHEAR ARE ENHANCED DUE TO BACKED WINDS ALONG
THE FRONT. PRECIPITABLE WATER VALUES IN THE INCH TO INCH AND A HALF
RANGE WILL ALSO PROMOTE LOCALLY HEAVY DOWNPOURS.
DRYLINE WILL CONTINUE RETREATING FRIDAY BY ENTERING NEW MEXICO
THANKS TO SOUTHEASTERLY LOW LEVEL FLOW ON THE BACKSIDE OF SURFACE
HIGH PRESSURE ACROSS THE EASTERN HALF OF THE COUNTRY AND LEE
TROUGHING NEAR THE FRONT RANGE. THIS WILL FAVOR WESTERN ZONES IN
TERMS OF THUNDERSTORM DEVELOPMENT FRIDAY INTO THE WEEKEND AS THE
DRYLINE PROVIDES THE FOCUS FOR INITIATION. AN UPPER LOW/TROUGH WILL
BEGIN TO MIGRATE OFF THE PACIFIC COAST INTO EARLY NEXT WEEK ALLOWING
THE DRYLINE TO BEGIN MIXING FARTHER EAST INTO THE SOUTH/ROLLING
PLAINS. WILL MAINTAIN A DRY FORECAST AFTER SUNDAY AS PROGRESSION OF
THIS SYSTEM AND DRYLINE PLACEMENT WILL DICTATE STORM CHANCES.
TEMPERATURES WILL HOLD NEAR NORMAL...GENERALLY RANGING IN THE MID
80S TO MID 90S FOR HIGHS WITH LOWS IN THE UPPER 50S TO MID 60S
UNDERNEATH A SOUTHWESTERLY FLOW REGIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 87 57 86 59 82 / 0 10 20 30 30
TULIA 88 59 86 62 83 / 0 10 40 40 20
PLAINVIEW 89 61 87 64 84 / 0 10 30 40 20
LEVELLAND 90 63 89 64 84 / 0 10 20 30 20
LUBBOCK 90 65 90 66 86 / 0 10 20 40 20
DENVER CITY 90 64 93 65 85 / 0 10 20 20 20
BROWNFIELD 92 65 90 65 86 / 0 10 20 30 20
CHILDRESS 91 63 88 65 85 / 10 10 60 60 20
SPUR 91 63 90 67 88 / 10 10 30 50 20
ASPERMONT 93 67 92 69 91 / 10 10 20 40 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/05
