Area Forecast Discussion
Issued by NWS Shreveport, LA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 KSHV 131135
AFDSHV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
635 AM CDT SUN APR 13 2014

.AVIATION...
MOSTLY MVFR CEILINGS DOMINATE THE AREAS TERMINAL EARLY THIS
MORNING. LOOK FOR THESE CONDITIONS TO CONTINUE THROUGH AT LEAST
THE MID MORNING HOURS WITH CEILINGS EXPECTED TO CLIMB TO NEAR
35HDFT-4KFT THROUGH THE AFTERNOON. THE EXCEPTION TO THIS SHOULD BE
ACROSS OUR NE TX TERMINALS INTO THE TX TERMINAL WHERE HRRR-3KM
REFLECTIVITY DATA IS IN GOOD AGREEMENT THAT CONVECTION SHOULD
BEGIN DEVELOPING BETWEEN 16Z AND 21Z. WOULD OBVIOUSLY EXPECT LOWER
CEILINGS WITH ANY CONVECTION THAT DEVELOPS LATER TODAY. KEPT THE
MENTION OF VCTS GOING FOR THESE TERMINALS WITH A TEMPO GROUP FOR
LOWER CEILINGS/VSBYS FOR LATE AFTERNOON INTO EARLY EVENING. FOR THE
MLU/ELD TERMINALS...THE ARRIVAL OF CONVECTION WILL BE MUCH LATER
TODAY...MORE LIKELY INTO THE EVENING/LATE OVERNIGHT HOURS. ALL
THIS CONVECTION WILL DEVELOP WELL AHEAD OF THE FRONTAL BOUNDARY
WHICH WILL LIKELY NOT BE MOVING INTO THE TXK/TYR TERMINALS UNTIL
NEAR OR SHORTLY AFTER 12Z MON.

UNTIL THAT TIME...EXPECT STRONG SOUTHERLY WINDS TODAY WITH A VERY
TIGHT PRESSURE GRADIENT IN PLACE. SUSTAINED WINDS WILL BE IN THE
13-16KT RANGE WITH GUSTS LIKELY APPROACHING 22-25KTS ACROSS MOST
TERMINAL LOCATIONS. GUSTS WILL LIKELY APPROACH 30KTS BY AFTERNOON
AT THE TYR/GGG/TXK TERMINALS.

OVERNIGHT...KEPT THE MENTION OF VCTS GOING AS NEW CONVECTION WILL
LIKELY DEVELOP ACROSS N TX/S OK IN VICINITY OF THE DRYLINE/COLD
FRONT MERGER AND THAT CONVECTION WOULD BE MOVING INTO OUR REGION
FROM THE WEST NEAR OR SHORTLY BEFORE SUNRISE MONDAY MORNING.

13

&&

.PREV DISCUSSION... /ISSUED 523 AM CDT SUN APR 13 2014/

DISCUSSION...
WATER VAPOR IMAGERY INDICATING THE LEAD UPPER LEVEL SHORT WAVE
EJECTING OUT OF THE FOUR CORNERS REGION INTO THE SRN PLAINS THIS
MORNING. MEANWHILE AT THE SFC...A COLD FRONT EXTENDS FROM EXTREME
SE NE BACK ACROSS KS WITH A LOW JUST SOUTH OF DDC VERY NEAR THE
BORDER WITH OK WHERE THE DRY LINE EXTENDS SOUTH ACROSS WRN OK/TX.
FARTHER SOUTH OVER OUR REGION...A FAIR AMOUNT OF STRATOCU IS SEEN
ON SATELLITE UNDER A THICK BLANKET OF CIRRUS STREAMING IN FROM
THE SW AHEAD OF THE AFOREMENTIONED SHORT WAVE. THIS IS SETTING THE
STAGE FOR OUR ANTICIPATED SEVERE WEATHER EVENT LATER TODAY...MORE
SPECIFICALLY LATE THIS AFTERNOON THROUGH THE OVERNIGHT HOURS INTO
MONDAY MORNING.

AS WE HAVE BEEN DISCUSSING THE PAST FEW DAYS...THIS EVENT WILL
LIKELY COME IN STAGES WITH THE LEAD SHORT WAVE MOVING IN THIS
AFTERNOON AND ELIMINATING THE RELATIVELY STRONG CAP IN PLACE THIS
MORNING. THE NAM HAS REALLY BACKED OFF ON THE CAP HOLDING SOLID
THIS AFTERNOON...COMING MORE IN LINE WITH THE GFS AND ECMWF. THIS
ALSO MATCHES UP WELL WITH THE HIGH RESOLUTION HRRR SUGGESTING
AMPLE REFLECTIVITY ACROSS OUR NW ZONES LATER THIS AFTERNOON. GIVEN
THIS SCENARIO...THE PRIMARY THREATS WITH THIS INITIAL WAVE OF
CONVECTION APPEAR TO BE LARGE HAIL AND DAMAGING WINDS WITH THE DRY
LINE STILL WELL TO THE WEST OF OUR REGION. DEPENDING ON HOW WORKED
OVER THE ATMOSPHERE BECOMES IN THE WAKE OF THE CONVECTION WITH THE
LEAD SHORT WAVE...INSTABILITY LATER IN THE EVENING MAY NOT BE
QUITE AS STRONG AS INDICATED JUST AHEAD OF THE DRY LINE AND COLD
FRONT WHICH NAM GUIDANCE SUGGESTS COULD BE CAPE OF 2000-2500 J/KG.
THIS WILL INDEED BEAR WATCHING AS LOW LEVEL AND DEEP LAYER SHEAR
WILL BE MORE THAN SUFFICIENT TO SUPPORT DEVELOPING SUPERCELLS AND
THE POSSIBILITY OF A FEW ISOLATED TORNADOES. THIS THREAT APPEARS
GREATEST OVER SE OK/NE TX CLOSER TO THE TRACK OF THE SFC LOW WHICH
IS EXPECTED TO RIDE ALONG THE RED RIVER VALLEY. AS THE COLD FRONT
BEGINS TO OVERTAKE THE DRY LINE AROUND MIDNIGHT...THE EVENT SHOULD
TRANSITION PRIMARILY TO A DAMAGING WIND THREAT AS AN INTENSE
SQUALL LINE IS LIKELY TO DEVELOP ALONG THE LEADING EDGE OR JUST
AHEAD OF THE COLD FRONT. EXPECT THIS LINE OF CONVECTION TO
GRADUALLY TRANSITION ACROSS THE REGION THROUGHOUT THE MORNING
HOURS ON MONDAY...THEN POSSIBLY FOLLOWED BY ANOTHER ROUND OF
WEAKER CONVECTION WITH A SECOND SHORT WAVE QUICKLY MOVING IN
BEHIND THE FRONT DURING THE AFTERNOON. THE FRONT WILL CLEAR THE
REGION BY EARLY MONDAY EVENING WITH PRECIPITATION ENDING SHORTLY
THEREAFTER.

OUR ATTENTION THEN TURNS TO THE MUCH COOLER AIR IN THE WAKE OF THE
COLD FRONT WITH AREAS OF NEAR FREEZING AND POSSIBLY SUB-FREEZING
TEMPERATURES ACROSS THE NRN PARTS OF THE REGION ON TUESDAY MORNING
AS WELL AS WEDNESDAY MORNING. THIS WILL BE MONITORED VERY CLOSELY
AND FREEZE WARNINGS MAY BE NEEDED OVER PARTS OF NE TX/SE OK/SW AR
DURING THIS TIMEFRAME. THE REMAINDER OF THE EXTENDED PERIOD WILL
BRING NEAR NORMAL TEMPERATURES WITH ANOTHER COLD FRONT AND
INCREASING RAIN CHANCES BY LATE THURSDAY INTO FRIDAY. A BRIEF
PERIOD OF DRY WEATHER LOOKS LIKELY FOR SATURDAY WITH RAIN
RETURNING ONCE AGAIN ON SUNDAY WITH AN UPPER LEVEL DISTURBANCE.
/19/

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  80  64  66  36  62 /  30  60  40  20  10
MLU  80  66  70  36  60 /  20  60  50  40  10
DEQ  75  54  56  31  61 /  40  70  30  10  10
TXK  78  58  60  34  61 /  40  70  30  10  10
ELD  78  63  64  33  60 /  20  70  50  30  10
TYR  79  56  61  34  62 /  30  50  30  10  10
GGG  79  59  61  35  62 /  30  50  30  10  10
LFK  81  65  67  36  63 /  30  50  40  20  10

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...LAKE WIND ADVISORY FROM 10 AM THIS MORNING TO 8 PM CDT THIS
     EVENING FOR THE FOLLOWING ZONES: ARZ050-051-059>061-070>073.

LA...LAKE WIND ADVISORY FROM 10 AM THIS MORNING TO 8 PM CDT THIS
     EVENING FOR THE FOLLOWING ZONES: LAZ001>006-010>014-017>022.

OK...LAKE WIND ADVISORY FROM 10 AM THIS MORNING TO 8 PM CDT THIS
     EVENING FOR THE FOLLOWING ZONES: OKZ077.

TX...LAKE WIND ADVISORY FROM 10 AM THIS MORNING TO 8 PM CDT THIS
     EVENING FOR THE FOLLOWING ZONES:
     TXZ096-097-108>112-124>126-136>138-149>153-165>167.

&&

$$

13





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