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742
FXUS64 KLUB 221147
AFDLUB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
647 AM CDT FRI MAY 22 2015

.AVIATION...
BAND OF SHOWERS WITH EMBEDDED THUNDER CONTINUES TO IMPACT KLBB AND
KPVW AND WILL SOON BE TO KCDS. ALTHOUGH PRECIPITATION WILL COME TO
AN END THIS MORNING...IFR CEILINGS WILL LIKELY PERSIST THROUGH
MUCH OF THE DAY FOR ALL SITES AS MOISTURE STREAMS INTO WEST TEXAS
ON SOUTHEAST WINDS. THUNDERSTORMS WILL GENERATE AGAIN THIS EVENING
ACROSS EASTERN NEW MEXICO AND MOVE TOWARD KLBB AND KPVW AFTER
MIDNIGHT. HAVE INSERTED -TSRA MENTION AND LIFR CEILINGS FROM
07-12Z FOR BOTH SITES AS CONFIDENCE IS FAIRLY HIGH IN WIDESPREAD
COVERAGE. KCDS SHOULD REMAIN EAST OF THE BRUNT OF ANY STORMS UNTIL
LIKELY AFTER 12Z SATURDAY.

&&

.PREV DISCUSSION... /ISSUED 448 AM CDT FRI MAY 22 2015/

SHORT TERM...
A CLUSTER OF SCATTERED TO NUMEROUS SHOWERS AND EMBEDDED
THUNDERSTORMS CONTINUES THIS MORNING ACROSS THE REGION AHEAD OF A
LEAD IMPULSE DOWNSTREAM OF AN UPPER LOW NEAR SOUTHERN CALIFORNIA.
STRONG MOIST ISENTROPIC ASCENT WAS ALSO PRESENT...HELPING TO PRODUCE
HOURLY RAINFALL RATES OF NEAR A QUARTER OF AN INCH. WILL SEE THE
BRUNT OF THIS ACTIVITY COME TO AN END THIS MORNING FROM WEST TO EAST
AS THE UPPER SUPPORT MOVES INTO THE CENTRAL PLAINS...BUT A STEADY
DOSE OF WARM AIR ADVECTION ATOP A RECOVERING BOUNDARY LAYER WILL
SPELL A LAYER OF LOW STRATUS LIKELY HOLDING STRONG MUCH OF THE DAY
WITH PERHAPS A PEAK OR TWO OF SUNSHINE IN THE SOUTH PLAINS. COULD
SEE AN ELEVATED STORM OR TWO POP THIS AFTERNOON GIVEN THE MOIST
AIRMASS IN PLACE AND PRESENCE OF A NORTHWARD LIFTING WARM
FRONT...BUT HEIGHT RISES ALOFT AND ASSOCIATED POOR MID-LEVEL LAPSE
RATES ABOVE STUBBORN STRATUS SHOULD MUTE ANY WIDESPREAD SIGNIFICANT
CONVECTION. TEMPERATURES SHOULD REBOUND FROM 20-30 DEGREE BELOW
NORMAL READINGS THE PAST TWO DAYS...BUT STILL TOP OUT WELL BELOW
AVERAGE MAINLY IN THE 60S WITH A FEW LOCATIONS IN THE EXTREME
SOUTHERN SOUTH PLAINS AND SOUTHERN ROLLING PLAINS CRACKING 70
DEGREES.

WARM AIR/MOISTURE ADVECTION WILL INCREASE IN EARNEST THIS
EVENING/TONIGHT AS THE AFOREMENTIONED SOUTHERN CALIFORNIA LOW MOVES
TOWARD THE FOUR CORNERS REGION. PWATS INCREASING TO 1.25-1.5 INCHES
WITH DEWPOINTS SURGING INTO THE 60S WILL HELP TO INCREASE CAPES INTO
THE 1-2 KJ/KG RANGE AS MID LEVEL LAPSE RATES STEEPEN COURTESY OF
COOLING TEMPERATURES ALOFT. A 30-40 KNOT LOW LEVEL JET WILL
CONTRIBUTE TO 30-40 KNOTS OF 0-6 KM BULK SHEAR THUS PROVIDING FOR
UPDRAFT ORGANIZATION ALTHOUGH STILL IN ALL LIKELIHOOD REMAINING
ELEVATED. STORM CHANCES WILL BE BEST TONIGHT FROM THE FAR SOUTHWEST
PANHANDLE INTO THE ADJACENT SOUTH PLAINS NEARER THE BRUNT OF THE
FORCING ALOFT. WHILE ALL SEVERE MODES WILL BE POSSIBLE...LARGE HAIL
WILL BE THE PRIMARY HAZARD AS A NARROW WINDOW WILL EXIST FOR
TORNADOES NEAR THE WARM FRONT AND WIND GUSTS DUE TO THE ELEVATED
NATURE OF THESE STORMS. MAY HAVE TO MORE CLOSELY MONITOR THE THREAT
FOR FLOODING INTO THE DAY ON SATURDAY. HAVE OPTED TO REFRAIN FROM
ISSUANCE OF ANY HEADLINES AT THIS TIME GIVEN THE STRENGTHENING DEEP
LAYER SYNOPTIC WIND FIELDS HELPING TO MOVE STORMS ALONG. FLOODING
WILL BE DRIVEN BY MESOSCALE PROCESSES...OWING TO THE DEVELOPMENT OF
ANY ORGANIZED COMPLEX OR MULTIPLE ROUNDS OF STORMS TRAINING OVER THE
SAME AREA. THE UPPER LOW IS ALSO EXPECTED TO WEAKEN AS IT LIFTS
OUT...PLACING THE SOUTH PLAINS AND ROLLING PLAINS REGION IN A
FAVORABLE POSITION TO BE DRY-SLOTTED. THEREFORE...WOULD LIKE TO SEE
HOW SMALLER SCALE PROCESSES PLAY OUT MOVING FORWARD BEFORE ISSUING A
FLOOD WATCH MORE THAN A DAY OUT. ADDITIONALLY...ANALOGS ARE ALSO
SILENT IN TERMS OF ANY FLOOD EVENTS WITH A PATTERN SIMILAR TO THIS.
NONETHELESS...THE MOISTURE AND LIFT WILL INITIALLY BE IN PLACE SUCH
THAT CLOSE MONITORING WILL BE NEEDED.

LONG TERM...
SATURDAY MORNING WILL SEE AN UPPER LOW CENTERED ACROSS NRN AZ/SRN UT
WITH SOUTHWESTERLY FLOW ENTRENCHED ACROSS WEST TEXAS. THIS LOW
WILL SLOWLY LIFT NEWRD INTO NRN CO BY SUNDAY MORNING BEFORE
FILLING ON MONDAY. AS SUCH A COUPLE OF RIBBONS OF VORTICITY WILL
AFFECT THE REGION AS EMBEDDED SHORTWAVES ROTATE ABOUT THE LOW
CENTER. YET STILL...ADDITIONAL SHORTWAVE DISTURBANCES IN THE SRN
BRANCH OF THE JET WILL CONTINUE TO ENHANCE LIFT PERIODICALLY IN
THE EXTENDED AS ACTIVE PATTERN CONTINUES. SATURDAY APPEARS TO BE
CHARACTERIZED BY A RATHER WET MORNING WITH CONVECTION PUSHING OFF
TO THE EAST BY THE AFTERNOON. THIS WILL LIKELY SERVE TO STABILIZE
THE ATMOSPHERE AND LIMIT THE POTENTIAL OF SEVERE CONVECTION TO
SOME EXTENT. STORM ACTIVITY SHOULD CONTINUE INTO SUNDAY FOCUSING
MORE ON THE ROLLING PLAINS BEFORE CONDITIONS DRY OUT FOR MONDAY.
YET...MONDAY NIGHT LOOKS TO SEE A RETURN OF THE ACTIVITY AS
MOISTURE ATTEMPTS TO GAIN A STRONGHOLD. THE GFS LOOKS TO REALLY
OVER-DO THE MOISTURE ADVECTION AND PREFER THE SOLUTION ADVERTISED
BY THE ECMWF AS THIS IS A KNOWN HISTORICAL BIAS OF THE GFS. ALL
IN ALL THE WET PATTERN CONTINUES IN THE LATTER EXTENDED. WILL NOT
TRY TO GET TOO CUTE WITH POPS AS SO MUCH OF THE RAIN WILL BE
DRIVEN BY MESOSCALE PROCESSES SUCH THAT A BLEND OF MODELS IS ABOUT
THE BEST CHOICE.

&&

.PRELIMINARY POINT TEMPS/POPS...
FRIONA        65  55  75  51 /  30  80  50  20
TULIA         62  57  71  53 /  50  70  60  30
PLAINVIEW     64  59  72  55 /  50  70  70  40
LEVELLAND     66  60  76  55 /  40  70  50  40
LUBBOCK       66  61  74  56 /  40  70  50  40
DENVER CITY   69  60  78  55 /  30  70  40  40
BROWNFIELD    68  60  75  55 /  40  70  50  40
CHILDRESS     65  61  72  59 /  80  60  80  50
SPUR          68  60  73  57 /  60  60  70  50
ASPERMONT     72  63  77  60 /  70  50  70  60

&&

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

$$

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