000
FXUS64 KFWD 162349
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
649 PM CDT SUN JUN 16 2013

.AVIATION...
DIFFICULT CONVECTIVE FORECAST DURING THE NEXT 12 HOURS DUE TO
DIFFERING MODEL OUTPUT AND CONVECTION LARGELY DRIVEN BY MESOSCALE
PROCESSES. CONVECTION WILL BE MOVING TOWARD THE REGION IN NW FLOW
ALOFT...BUT WHETHER THERE IS THE SUPPORT FOR IT TO HOLD TOGETHER
LONG ENOUGH TO IMPACT THE TAF SITES IS A BIT MORE IN QUESTION.
AIRMASS OVER THE REGION IS NOT ESPECIALLY FAVORABLE
THERMODYNAMICALLY...NOR ARE THE LOW LEVEL WIND FIELDS VERY
IMPRESSIVE FOR A GOOD MCS PROPAGATION EVENT. NONETHELESS MODELS
ARE SHOWING TWO WINDOWS OF POSSIBLE CONVECTIVE ACTIVITY IN NORTH
TEXAS.

THE FIRST ONE WOULD BE LATE EVENING FROM 4Z-8Z AS ADVERTISED BY
THE RUC/4KMWRF/NAM AND PREVIOUS RUNS OF THE HRRR...WHICH TAKE
CURRENT CONVECTION IN OKLAHOMA AND GROW IT UPSCALE DURING THE
NEXT 2 HOURS AND PUSH IT INTO THE METROPLEX BEFORE MIDNIGHT LOCAL.
CURRENT RADAR TRENDS TO OUR NORTH DO NOT SEEM TO SUPPORT THIS IDEA
WITH CONVECTION REMAINING A BIT TOO ISOLATED FOR GOOD COLD POOL
DEVELOPMENT. THESE MODELS CAN HAVE ISSUES WITH OVER-ESTIMATING THE
INFLUENCE OF OUTFLOWS ENHANCING CONVECTION AND ITS PROPAGATION.
WILL NOT MENTION VCTS FOR THIS THREAT WINDOW BUT WILL CONTINUE TO
MONITOR TRENDS DURING THE NEXT COUPLE OF HOURS AND JUMP ON IT IF
ACTIVITY CAN INCREASE IN COVERAGE BETWEEN OKC-FDR.

THE SECOND WINDOW OF CONVECTIVE OPPORTUNITY WILL BE FROM 10Z TO
14Z FROM CONVECTION NOW FORMING IN COLORADO. THIS HAS A BETTER
SHOT TO MAKE IT INTO THE AREA...AS IT WILL BE SUPPORTED BY LIFT
FROM A SHORTWAVE TROUGH. THE LATEST RUN OF THE HRRR AND A HI-RES
WRF ARE HITTING ON THIS POTENTIAL WITH A DECAYING MCS ARRIVING
NEAR OR JUST BEFORE SUNRISE. AM ALMOST READY TO INCLUDE VCTS IN
TAFS FROM 10Z-13Z...BUT WILL WAIT TO SEE HOW CONVECTION EVOLVES IN
THE HIGH PLAINS AND WHETHER THE FIRST POSSIBLE ROUND OF CONVECTION
NOW OVER OKLAHOMA DOES IN FACT STEAL THE SHOW.

SO IN SUMMARY NO CHANGES WITH THE 00Z TAF ISSUANCE JUST YET...BUT
AMENDMENTS FOR A WINDOW OF VCTS LOOK LIKELY IN THE NEXT 2-3
HOURS.

TR.92

&&


.PREV DISCUSSION... /ISSUED 251 PM CDT SUN JUN 16 2013/
A LESS ACTIVE AFTERNOON TODAY VERSUS THIS TIME YESTERDAY WITH THE
OLD UPPER TROUGH NOW LONG GONE AND AN UPPER RIDGE THAT HAS EXPANDED
WESTWARD ACROSS SOUTH/CENTRAL TX. THOUGH A ROGUE ISOLATED STRONG
STORM IS POSSIBLE NORTH OF I-20 THIS AFTERNOON...BETTER CHANCES
WILL LIKELY COME LATER TONIGHT. A SHORTWAVE OVER THE OK/TX
PANHANDLES WILL MOVE ESE TOWARD THE RED RIVER VALLEY AFTER MIDNIGHT.
A FEW STORMS WERE ALREADY POPPING ACROSS CENTRAL AND NORTHERN OK.
HIGH RESOLUTION HRRR/ARW-EAST/TEXAS TECH WRF MODELS ALL SHOW
CURRENT ISOLATED STORMS OVER NW OK INCREASING IN COVERAGE IN A
WEST-EAST LINE THIS EVENING...THEN DIVING SOUTHEAST TOWARD THE RED
RIVER LATE TONIGHT. TIMING THE LINEAR MCS TONIGHT IS SOMEWHAT
PROBLEMATIC HOWEVER AS THE HRRR IS MUCH FASTER THAN THE OTHER TWO
MODELS IN BRINGING ACTIVITY INTO THE RED RIVER VALLEY. CONSIDERING
WHERE THIS ACTIVITY IS FORMING AT THE MOMENT...WILL GO WITH THE
SLOWER TIMING MOSTLY BETWEEN MIDNIGHT AND SUNRISE MONDAY MORNING.
POPS WILL VARY FROM 50 PERCENT ACROSS THE IMMEDIATE RED RIVER AREA
TO AROUND 20 PERCENT ACROSS THE I-20 CORRIDOR. THE LINEAR MCS
SHOULD WEAKEN WITH THE VEERING/WEAKENING OF A 30-35KT NOCTURNAL
LLJ NEAR SUNRISE MONDAY MORNING.

THE FORECAST FOR LATER MONDAY AND THROUGH EARLY WEDNESDAY BECOMES A
BIT MORE DIFFICULT DUE TO THE UPPER RIDGE ANCHORED OVER SOUTH AND
CENTRAL TX AND WHERE ANY OUTFLOW BOUNDARIES SET UP ACROSS THE
NORTH. HAVE LINGERED BEST CHANCES AFTER SUNRISE MONDAY ACROSS THE
NORTHEAST COUNTIES WITH THE WEAKENING COMPLEX AND A SHORTWAVE
PASSING SOUTHEAST OVER ARKANSAS. LOW CHANCES LOOK PRUDENT FOR THE
AFTERNOON HOURS NEAR ANY OUTFLOWS ACROSS THE NORTHERN HALF OF THE
CWA. BY MONDAY NIGHT...ANOTHER SHORTWAVE DISTURBANCE MOVES EAST
FROM WEST TX AND WILL CARRY HIGHER CHANCES ACROSS THE WESTERN
COUNTIES BY MONDAY EVENING. THIS SYSTEM SHOULD WEAKEN AS IT HITS
THE RIDGE OVERNIGHT AND INTO TUESDAY MORNING. ON MORE SHORTWAVE
WILL TRANSITION SOUTHEAST OVER THE TOP OF THE UPPER RIDGE AND
TOWARD OUR OLD OUTFLOW BOUNDARY OVER THE NORTHERN COUNTIES WITH
ISOLATED TO SCATTERED STORMS FOR THE PM HOURS ONCE AGAIN. FEEL THE
UPPER RIDGE WILL KEEP AREAS FROM WACO AND ATHENS SOUTHWARD MAINLY
CAPPED AND DRY...THOUGH A ROGUE SHOWER CANNOT BE COMPLETELY RULED
OUT OVER OUR CENTRAL TX COUNTIES.

THE UPPER RIDGE EXPANDS NORTHWARD OVER NORTH TEXAS WEDNESDAY AS AN
UPPER LOW AND ASSOCIATED LONGWAVE TROUGH DEEPEN ACROSS THE WESTERN
U.S. HAVE LINGERED LOW RAIN CHANCES ACROSS THE FAR NORTHEAST CWA
WHERE SOME WEAKNESS ALOFT WILL REMAIN...BUT CONFIDENCE WILL BE
WANING BY THEN ON RAIN CHANCES. SUBSIDENCE AND DRY/HOT WEATHER
TAKE HOLD THE LATTER HALF OF THE WEEK INTO NEXT WEEKEND WITH RAIN
CHANCES NEAR ZERO. HIGHS WILL RISE INTO THE UPPER 90S AND 100 BY
FRIDAY AND SATURDAY...ESPECIALLY ACROSS THE WESTERN COUNTIES BY
NEXT WEEKEND.

05/

&&



.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  77  93  75  89  75 /  20  20  30  30  20
WACO, TX              75  95  75  92  75 /   5   0  20  10  10
PARIS, TX             74  90  72  87  71 /  50  50  20  40  40
DENTON, TX            76  91  73  88  73 /  30  30  30  40  30
MCKINNEY, TX          75  92  72  88  72 /  30  30  20  40  30
DALLAS, TX            77  94  75  89  76 /  20  20  20  30  20
TERRELL, TX           75  93  74  89  73 /  20  20  20  30  20
CORSICANA, TX         75  95  74  91  74 /   5   5  20  10  10
TEMPLE, TX            75  96  73  93  73 /   5   0  10  10  10
MINERAL WELLS, TX     75  93  73  89  71 /  30  20  40  30  20

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

 /