River Flood Warning 46, NWS Fort Worth, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
132 AM CDT THU APR 10 2008

.UPDATE...
HAVE MADE A QUICK UPDATE AS WINDS ACROSS THE ENTIRE AREA HAVE
REACHED OR ARE APPROACHING ADVISORY CRITERIA. GUIDANCE CONTINUES
TO SHOW VERY STRONG WINDS THIS AFTERNOON...SO NEWLY ISSUED WIND
ADVISORY WILL BE IN EFFECT UNTIL TONIGHT.  SH/13

&&

.PREV DISCUSSION... /ISSUED 1143 PM CDT WED APR 9 2008/

AVIATION...
/06Z TAFS/
BEST EXTRAPOLATION OF SQUALL LINE APPROACHING THE METRO IS BETWEEN
08Z AND 11Z. SOME UNCERTAINTY IN HOW QUICK SKIES WILL CLEAR BEHIND
THE SQUALL LINE...WHICH PLAYS INTO DEVELOPMENT OF FOG. FOR
NOW...WILL KEEP STRATUS IN THROUGH 15Z WITH JUST MVFR VSBYS DUE TO
WIND AND CLOUDS. HOWEVER...IF SKIES CLEAR IMMEDIATELY BEHIND THE
PRECIP...EXPECT SOME GROUND FOG TO DEVELOP...WHICH COULD BE DENSE
IN SOME AREAS.

EXPECT VFR CONDITIONS AFTER 15Z.

SCHULTZ

PREV DISCUSSION... /ISSUED 1046 PM CDT WED APR 9 2008/

UPDATE...
QUICK UPDATE TO THE ZONES TO ACCOUNT FOR NEW TORNADO WATCH. TOR
BOX 184 IS VALID THROUGH 6 AM AND WILL COVER AREAS ALONG AND WEST
OF A PARIS TO TERRELL TO LAMPASAS LINE. THIS BOX WILL REPLACE TOR
BOX 179.

AN ADDITIONAL WATCH BOX MAY BE REQUIRED FOR SOUTHEASTERN PORTIONS
OF THE FORECAST AREA AFTER MIDNIGHT.

OTHERWISE...CONVECTION IS LINING UP TO OUR WEST AS EXPECTED. WE
ANTICIPATE STORMS APPROACHING OUR WESTERN ZONES AROUND 2
AM...PROGRESSING TO THE I-35 CORRIDOR BY 4 AM OR AFTER.

SCHULTZ

PREV DISCUSSION... /ISSUED 919 PM CDT WED APR 9 2008/

UPDATE...
MINOR UPDATE TO DECREASE POPS FURTHER FOR AREAS ALONG/SOUTH OF
INTERSTATE 20 CORRIDOR AND TO ALSO CANCEL TOR WATCH #179 FOR THOSE
SAME AREAS...AS CAP HAS REMAINED STRONG ENOUGH THAT THESE AREAS
WILL HAVE TO WAIT FOR BETTER LARGE-SCALE ASCENT AFTER MIDNIGHT
WITH DRY-LINE APPROACHING FROM THE WEST AND DISTURBANCE ALOFT
CURRENTLY OVER TX BIG BEND COUNTRY EJECTING ENE TOWARD N TX.
ONLY NRN TWO TIERS OF COUNTIES NEAR THE RED RIVER...CLOSER TO THE
SFC WARM FRONT WILL REMAIN IN THE CURRENT TOR WATCH UNTIL 11 P.M
CDT. EXPECT A SQUALL LINE TO PUSH FROM WEST TO EAST INTO WRN
SECTION OF N TX SOMETIME BY 1-3 A.M...THEN LINGER OVER AREAS
ALONG/E OF I-35 DURING THE MORNING HRS THURSDAY.

UPDATES AND WATCH(WCN) UPDATES ALREADY SENT. WEB IMAGE TO BE
UPDATED SHORTLY...AS WILL HAZARDOUS WX OUTLOOK.  /05

PREV DISCUSSION... /ISSUED 815 PM CDT WED APR 9 2008/

UPDATE...
TOR WATCH #178 FOR THE WRN 1/3 OF N TX WAS ALLOWED TO EXPIRE AT 8
PM CDT...PER LULL EXPECTED UNTIL DISTURBANCE NEGATIVELY TILTING
ACROSS FAR W TX PUSHES DRY-LINE TOWARD N TX LIKELY AFTER MIDNIGHT
AND THROUGH THE MORNING HOURS THURSDAY. HOWEVER...WITH SUPERCELL
TORNADIC STORM BETWEEN DENTON AND BOWIE...AND WITH OTHER ACTIVITY
NEAR YOUNG/JACK COUNTIES...HAVE ADDED JACK/YOUNG/WISE/AND MONTAGUE
TO TOR WATCH #179 FURTHER TO THE EAST...TO EXTEND THE WATCH FOR
THOSE COUNTIES THROUGH 11 P.M CDT. WITH ALL THIS IN MIND WITH THE
BRIEF RESPITE THROUGH THE LATE EVENING AND STRONGER CAP OVER S/SE
COUNTIES...HAVE ADJUSTED HIGHEST POPS TO MAINLY ALONG/N OF I-20
FOR THIS EVENING...BEFORE SQUALL LINE RACES IN FROM THE WEST
BEFORE DAYBREAK THURS A.M. HAVE TONED POPS DOWN S OF I-20 TO LOW
CHANCE AND SLIGHT CHANCE WORDING...AS LIFT COULD STILL INITIATE A
FEW DISCRETE STORMS THROUGH THE CAP.

UPDATES SENT. HAZARDOUS WX OUTLOOK AND WEB GRAPHICS TO BE UPDATED
SHORTLY. /05

PREV DISCUSSION... /ISSUED 613 PM CDT WED APR 9 2008/

AVIATION...
/00Z TAFS/
DIFFICULT FORECAST IN REGARDS TO TIMING OF STORMS OVER TERMINALS.
LIGHT SHOWERS SHOULD CONTINUE ACROSS ALL SITES DURING THE NEXT
SEVERAL HOURS...WITH A FEW EMBEDDED THUNDERSTORMS.

STILL EXPECT A ROUND OF SEVERE THUNDERSTORMS TO IMPACT
AIRPORTS...ESPECIALLY METRO SITES AFTER 01Z. WILL LIKELY NEED
AMENDMENTS TO BETTER TIME APPROACH OF STRONGEST STORMS THROUGHOUT
THE EVENING.

EXPECT PERIODS OF STORMS DURING THE NIGHT. STORMS WILL FINALLY
CLEAR OUR SITES BETWEEN 13 AND 16Z THURSDAY.

MVFR CIGS WILL PREVAIL...THOUGH POCKETS OF IFR WILL BE POSSIBLE.

SCHULTZ

PREV DISCUSSION... /ISSUED 400 PM CDT WED APR 9 2008/

DISCUSSION...
400 PM CDT

STRONG SW WINDS AHEAD OF APPROACHING SYSTEM (700-600MB) HAVE
CREATED SIGNIFICANT CAP AT 700MB (10C)...EVIDENT ON 18Z FWD
SOUNDING. ACARS SOUNDINGS SHOWING CAP OF AT LEAST 8C NEAR 700MB AS
RECENT AS 2 PM. THIS HAS KEPT THE SFC LAYER UNTAPPED...THOUGH
SOME ELEVATED CONVECTION HAS DEVELOPED NORTH OF DFW...AIDED BY THE
ENHANCED MID-LEVEL LAPSE RATES (7-8C/KM) OWING TO WARM/DRY
ADVECTION WITHIN ELEVATED INVERSION. ACARS GIVING EVIDENCE OF
LARGE SCALE LIFT RAISING/COOLING INVERSION AT A RATE OF 25MB/HR.
AT THIS RATE...EROSION MAY OCCUR AS EARLY AS 6 PM...WITH SUDDEN
INITIATION OF SFC-BASED CONVECTION THEREAFTER.

AS ANTICIPATED...BEST TORNADIC PARAMETERS ARE TO THE WEST. 0-1KM
SHEAR IS NEAR 50KTS AT INTERSECTION OF LUB/OUN/SJT COUNTY WARNING
AREAS...SEVERAL HUNDRED 0-1KM SRH. 100MB MLCAPE VALUES IN EXCESS
OF 2000J/KG WHERE SFC TEMPS ARE WELL INTO THE 80S (SAN ANGELO...
PAINT ROCK...IVIE RESERVOIR). CERTAINLY FAVORABLE ENVIRONMENT
FURTHER EAST WITHIN FWD PORTION OF TOR WATCH 178...LCL AOB 2KFT
WEST OF I-35 CORRIDOR. SUPERCELL NEAR ABILENE ROOTED IN THE
BOUNDARY LAYER WILL CONTINUE TO FIND ABUNDANT UNTAPPED FUEL AS IT
APPROACHES FWD CWA. AT THIS TIME...CIN SHOULD BE MORE EFFECTIVELY
ERODING IN WESTERN REACHES OF CWA.

CONVECTION SHOULD CONTINUE THROUGHOUT THE EVENING HOURS. A BREAK
IS LIKELY TO OCCUR OVERNIGHT BEFORE DRYLINE SURGE AND ASSOCIATED
SQUALL LINE BLOWS THROUGH CWA. LINE SHOULD BE NEAR I-35 CORRIDOR
NEAR OR AFTER DAYBREAK...INTO EASTERN ZONES MIDDAY INTO THE
AFTERNOON. TRANSITION FROM SIGNIFICANT POPS TO MINIMAL CLOUDCOVER
WILL BE RAPID IN REALITY...BUT MORE CONSERVATIVE IN GRIDS DUE TO
SOME UNCERTAINTY IN TIMING. THURSDAY WORDING IN ZFP MAY BE
MISLEADING.

COLD FRONT THURSDAY NIGHT...REINFORCING COOL AIR THROUGHOUT THE
WEEKEND...BUT PLEASANT AFTERNOON TEMPS NONETHELESS. DEBATE AMONG
MODELS AND BETWEEN MODEL RUNS ABOUT FROPA MIDDLE OF NEXT WEEK.
FOR NOW...HAVE CHOSEN TO KEEP NORTH TEXAS IN SOUTHERLY FLOW DAYS
5-7 (MON-WED). 25

&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  76  52  70  46 /  20   0   0   0
WACO, TX              82  53  74  47 /  20  10   0   0
PARIS, TX             75  48  69  43 /  60  10   0   0
DENTON, TX            80  47  69  43 /  20   0   0   0
MCKINNEY, TX          79  50  70  45 /  30   0   0   0
DALLAS, TX            78  54  71  47 /  20   0   0   0
TERRELL, TX           79  53  72  45 /  40  10   0   0
CORSICANA, TX         81  55  75  46 /  30  10   0   0
TEMPLE, TX            81  54  75  46 /  20  10   0   0

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR TXZ091>095-100>107-
115>123-129>135-141>148-156>162-174-175.

FLASH FLOOD WATCH UNTIL NOON CDT TODAY FOR TXZ091>095-100>107-
115>120-129.

&&

13

HAZARDOUS WEATHER OUTLOOK FOR NORTH TEXAS...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
925 PM CDT WED APR 9 2008

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-101100-
ANDERSON-BELL-BOSQUE-COLLIN-COMANCHE-COOKE-CORYELL-DALLAS-DELTA-
DENTON-EASTLAND-ELLIS-ERATH-FALLS-FANNIN-FREESTONE-GRAYSON-HAMILTON-
HENDERSON-HILL-HOOD-HOPKINS-HUNT-JACK-JOHNSON-KAUFMAN-LAMAR-LAMPASAS-
LEON-LIMESTONE-MCLENNAN-MILAM-MILLS-MONTAGUE-NAVARRO-PALO PINTO-
PARKER-RAINS-ROBERTSON-ROCKWALL-SOMERVELL-STEPHENS-TARRANT-VAN ZANDT-
WISE-YOUNG-
925 PM CDT WED APR 9 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH TEXAS.

.DAY ONE...TODAY AND TONIGHT.
THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS NAMELY THOSE
AREAS OF NORTH TEXAS CLOSE TO A SURFACE WARM FRONT NORTH OF
INTERSTATE 20 AND NEAR THE RED RIVER. MAIN HAZARDS THROUGH TONIGHT
WILL BE VERY LARGE HAIL...DAMAGING WINDS...LOCALLY HEAVY RAINFALL
AND A FEW ISOLATED TORNADOES WILL BE POSSIBLE NEAR THESE AREAS.

ELSEWHERE...THUNDERSTORMS WILL CONTINUE TO DEVELOP INTO A SQUALL LINE
OVER WEST TEXAS THROUGH MIDNIGHT...THEN SPREAD EAST INTO NORTH TEXAS
AFTER MIDNIGHT AND THROUGH DAYBREAK THURSDAY MORNING. LARGE HAIL...
HEAVY RAINFALL...FREQUENT LIGHTNING AND WINDS IN EXCESS OF 60 MPH
ARE ALL POSSIBLE WITH THIS ACTIVITY LATE TONIGHT.

A FLASH FLOOD WATCH IS IN EFFECT FOR AREAS ALONG AND NORTH OF
INTERSTATE 20 THROUGH THURSDAY MORNING. ADDITIONAL RAINFALL AMOUNTS
OF 1 TO 3 INCHES WILL BE LIKELY...WITH ISOLATED AMOUNTS UP TO 4
INCHES POSSIBLE.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH MONDAY.
A LINE OF STRONG TO SEVERE THUNDERSTORMS IS EXPECTED EARLY THURSDAY
MORNING ALONG AND AHEAD OF AN EASTWARD MOVING COLD FRONT. THE SEVERE
WEATHER THREAT INCLUDES FREQUENT LIGHTNING...DAMAGING WINDS...
AND LARGE HAIL.

THE SEVERE WEATHER THREAT WILL END FROM WEST TO EAST BY THURSDAY
AFTERNOON.

BEHIND THE COLD FRONT...STRONG WESTERLY WINDS OF 25 TO 30 MPH...WITH
GUSTS TO 40 MPH ARE EXPECTED THURSDAY AFTERNOON.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION WILL LIKELY BE NEEDED ACROSS MUCH OF NORTH TEXAS
THROUGH THE OVERNIGHT.

05/

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FORT WORTH TX
938 PM CDT WED APR 09 2008

..TIME..    ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE..    ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0930 PM     FLASH FLOOD      GAINESVILLE             33.64N  97.15W
04/09/2008                   COOKE              TX   EMERGENCY MNGR

            WATER RESCUE IN GAINESVILLE. MINOR CITY STREETS FLOODED,
            SOME CLOSED ACROSS THE COUNTY.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FORT WORTH TX
1000 PM CDT WED APR 09 2008

..TIME..    ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE..    ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0957 PM     FLASH FLOOD      1 S ERA                 33.48N  97.29W
04/09/2008                   COOKE              TX   EMERGENCY MNGR

            FM 51 CLOSED 1 MILE SOUTH OF ERA. NUMEROUS INTERSECTIONS
            CLOSED IN GAINESVILLE