Area Forecast Discussion
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FXUS64 KLUB 290440
AFDLUB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
1140 PM CDT THU APR 28 2016

.AVIATION...
AVIATION CONCERNS WILL BE THE DEVELOPMENT OF LOW STRATUS
OVERNIGHT...WHICH IS MORE LIKELY AT KCDS BUT MAY BRING IFR TO
MVFR CEILINGS AT ANY OF THE TERMINALS. ALSO...A LINE OF T-STORMS
WILL MOVE ACROSS THE AREA DURING THE EARLY MORNING HOURS AND WILL
LIKELY IMPACT ALL THE TERMINALS. THEN DURING THE DAY
FRIDAY...GUSTY SOUTHWESTERLY WINDS WILL SPREAD ACROSS THE AREA.

&&

.PREV DISCUSSION... /ISSUED 1020 PM CDT THU APR 28 2016/

UPDATE...
WE FINALLY HAVE A LULL IN CONVECTION AFTER A FAIRLY
AFTERNOON/EVENING. THE DRYLINE IS CURRENTLY RETREATING WESTWARD
AT AN UNEVEN PACE. THERE IS NO LINE OF REFERENCE TO DESCRIBE ITS
CURRENT POSITION. THE BEST DESCRIPTION IS THE DRY SECTOR IS ALL
OF EASTERN NM AS WELL AS A BULGE ACROSS THE SOUTHERN HALF OF
BAILEY COUNTY...ALL OF COCHRAN AND YOAKUM COUNTIES...AND ALL BUT
EASTERN LAMB COUNTY. THERE IS A VERY SHARP MOISTURE GRADIENT WHERE
DEWPOINTS AHEAD OF THE DRYLINE ARE IN THE MID 40S TO UPPER 50S
WHILE DEWPOINTS BEHIND THE DRYLINE ARE LUCKY IF THEY ARE IN THE
20S. THE MAIN UPPER LEVEL FORCING FROM THE APPROACHING LOW IS
STILL WELL TO OUR WEST AND WILL NOT BE HERE TILL SOME TIME AROUND
OR AFTER MIDNIGHT...MOST LIKELY THE LATER. HI RES MODELS SUCH AS
THE HRRR AND THE 00Z NAM CONTINUE TO SHOW CONVECTIVE INITIATION
MUCH FARTHER WEST THAN PREVIOUSLY ANTICIPATED. GIVEN THE CURRENT
SPEED OF THE RETREATING DRYLINE I WOULD HAVE TO AGREE WITH THE
MODELS. THE CURRENT THOUGHT IS THAT THE FIRST CONVECTION TO
GO...AS WELL AS BE THE HEAVIEST/STRONGEST...WILL BE OVER
COCHRAN/LAMB COUNTIES WHERE THERE IS A BULGE IN THE DRYLINE. THIS
BULGE APPEARS TO HAVE CREATED A MESO SURFACE LOW CENTERED OVER
ROOSEVELT COUNTY, NM SHOULD SHOULD PROVIDE AMPLE SURFACE BASED
LIFT. THE MAIN STORM MODE APPEARS TO BE LINEAR AS THE DRYLINE
PROGRESSES EASTWARD THROUGH THE LATE OVERNIGHT/EARLY MORNING
HOURS. WHILE HAIL WILL CONTINUE TO BE THE MAIN THREAT A FEW
TORNADOES CANNOT BE RULED OUT ESPECIALLY ACROSS THE EASTERN HALF
OF THE FA. FORECAST HODOGRAPHS ARE CURVED IN NATURE STARTING JUST
WEST OF THE I27 CORRIDOR AND INCREASE THE FARTHER EAST YOU GO.

THE FORECAST WILL BE UPDATED TO REFLECT CURRENT CONDITIONS
FAVORING CONVECTIVE DEVELOPMENT FURTHER WEST. A MENTION OF SEVERE
STORMS WILL CONTINUE IN THE UPDATED FORECAST. ALDRICH

PREV DISCUSSION... /ISSUED 242 PM CDT THU APR 28 2016/

SHORT TERM...
MOISTURE RETURN HAS BEEN FAIRLY ROBUST WITH THETA-E AXIS
EXTENDING JUST WEST OF THE US-87 I-27 CORRIDOR THENCE CURVING BACK
A BIT NORTHWEST TOWARD DIMMITT. CUMULUS HAS DEVELOPED ALONG THE
WESTERN EDGE OF THE AXIS AND THIS IS AN AREA WHICH IS HINTED AT
FOR INITIATION BY MANY OF THE HIGHER RESOLUTION NWP SOLUTIONS.
OVER THE PAST SEVERAL HOURS...THE THETA-E RIDGE HAS BECOME A BIT
MORE N/S ORIENTED AND WHILE THE ORIENTATION OF THE MID LEVEL FLOW
IS NOT NEARLY AS NORMAL TO THE SURFACE BOUNDARY...IT SHOULD REMAIN
FAVORABLE FOR DISCRETE CONVECTION. WINDS CONTINUE TO BACK
ESPECIALLY ACROSS THE NORTHEASTERN SOUTH PLAINS AND NORTHERN
ROLLING PLAINS GIVEN PRESSURE FALLS TO OUR WEST IN RESPONSE TO
APPROACHING UPPER LEVEL LOW. THIS WILL HELP TO INCREASE LOW LEVEL
HELICITY AND ENHANCE RISK OF LOW LEVEL ROTATION. 0-1KM SHEAR IS
NOT TERRIBLY IMPRESSIVE THIS AFTERNOON BUT DOES RAMP UP SHARPLY
FOR THE SECOND ROUND OF SEVERE CONVECTION TONIGHT. HAVE INCREASED
POPS FOR THIS AFTERNOON ACROSS THE EASTERN PART OF THE CWFA ALONG
WITH ATTENDANT MENTION OF SEVERE. THREAT OF
BASEBALLS/70MPH/TORNADOES CONTINUES TO LOOK REASONABLE. OVERALL A
GUARDED VIGILANCE OF WEATHER CONDITIONS REMAINS WARRANTED THIS
AFTERNOON AND OVERNIGHT.

LONG TERM...
AN UNSETTLED PATTERN OF WEATHER WILL CONTINUE IN THE LONG TERM
FORECAST. A COLD FRONT WILL SWEEP THROUGH THE REGION FRIDAY NIGHT
RELIEVING THE AREA OF DRY CONDITIONS WEST OF THE DRYLINE. THIS
FRONT COMBINED WITH A WEAK SHORT WAVE ALOFT MAY BE ABLE TO
INITIATE SOME CONVECTIVE ACTIVITY IN EASTERN NEW MEXICO TOWARDS
THE TEXAS/NEW MEXICO BORDER. HOWEVER...STORMS WOULD LIKELY HAVE A
DIFFICULT TIME MAINTAINING THEMSELVES GIVEN AN AREA OF UPPER LEVEL
CONVERGENCE ASSOCIATED WITH THE UPPER LEVEL JET STREAK OVERHEAD.

ADDITIONAL SHORT WAVES WILL CONTINUE TO ROTATE AROUND A NEARLY
STATIONARY UPPER LEVEL LOW IN EASTERN COLORADO THIS WEEKEND. THE
NEXT WEAK SHORT WAVE WILL ARRIVE SATURDAY NIGHT COUPLED AGAIN WITH
ANOTHER COLD FRONT WHICH MAY AGAIN BRING IN SOME CONVECTION FROM
THE WEST. RIDGING ALOFT WILL QUICKLY FOLLOW THIS SHORT WAVE SO
PROSPECTS FOR CONVECTIVE DEVELOPMENT ARE LOW.

THE NEXT UPPER LEVEL SYSTEM WILL DROP DOWN THE CASCADES AND SIERRA
NEVADA RANGES INTO SOUTHERN ARIZONA ON SATURDAY AND SUNDAY. THIS
WILL CAUSE UPPER FLOW LOCALLY TO BACK TO THE SOUTHWEST AHEAD OF
THIS SYSTEM. THIS SYSTEM WILL WEAKEN AS IT MOVES OUT OF THE
SOUTHWESTERN US NEXT WEEK BUT BEST CHANCES FOR CONVECTION LOOK TO
BE SUNDAY AND MONDAY. LIFT WILL BE DRIVEN BY SHORT WAVES OUT AHEAD
OF THIS TROUGH AND MOIST ISENTROPIC ASCENT. WE WILL GENERALLY BE
UNDER COOL EASTERLY FLOW TO START OFF NEXT WEEK IN THE WAKE OF THE
COLD FRONT ON SATURDAY. THIS WILL ALSO KEEP TEMPERATURES
UNSEASONABLY COOL KEEPING PROSPECTS OF SEVERE STORMS LOW. AFTER
THIS SYSTEM EXITS...WE WILL BE UNDER UPPER LEVEL RIDGING FOR THE
MIDDLE PART OF NEXT WEEK. ALTHOUGH MODELS HAVE INDICATED THE
POTENTIAL FOR NORTHWEST FLOW STORMS IN THIS PATTERN.

&&

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

$$

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