Severe Thunderstorm Warning 324, NWS Little Rock, AR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LITTLE ROCK AR
617 PM CDT WED SEP 28 2005

.MESOSCALE UPDATE...
UPDATED ALL FORECAST PRODUCTS TO FRESHEN UP HOURLY GRIDDED
DATA...AND TO ADD SEVERE THUNDERSTORM WATCH NUMBER 823.
ALSO...ADDED WIND GUST POTENTIAL TO THE WEST AS THE FRONT MOVES
THROUGH LATER THIS EVENING.

TWO LINES OF SHOWERS AND THUNDERSTORMS STRETCH ACROSS NORTHERN AND
WESTERN ARKANSAS FROM FULTON COUNTY TO NEWTON COUNTY...AND FROM
LOGAN/YELL COUNTY THROUGH SOUTHERN SCOTT COUNTY. THESE HAVE FORMED
ALONG PRE-FRONTAL TROUGH AXIS ORIENTED SW-NE OVER WESTERN AND
NORTHERN ARKANSAS. WHILE ISOLATED HAILERS ARE POSSIBLE...STORMS
HAVE BEEN AND WILL CONTINUE TO BE MOSTLY WIND PRODUCERS...AS HOT
SURFACE TEMPS AND APPROACHING COLD AIR INTERACT. FAIRLY IMPRESSIVE
BOWING HAS BEEN NOTED...WITH LARGELY OUTFLOW-DOMINANT STORMS.
EXPECT THIS THREAT TO CONTINUE FOR SEVERAL MORE HOURS...GRADUALLY
DECREASING AS THE LINE ENCOUNTERS SLIGHTLY MORE STABLE AIR TOWARD
THE MS RIVER.
&&

.PREV DISCUSSION.../ISSUED 215 PM CDT WED SEP 28 2005/

SHORT  TERM...TONIGHT THROUGH SUNDAY
MODELS IN TWO CAMPS THIS AFTERNOON WITH THE GEM AND NAM LEANING
TOWARDS A WEAKER MORE PROGRESSIVE SOLUTION WHILE GFS/GEM/ECMWF
SOLUTIONS ARE MORE AMPLIFIED AND SUBSEQUENTLY SLOWER. DECIDED TO GO
WITH THE GFS SOLUTION FOR POSITIONING AND TIMING OF THE MAJOR
PLAYERS AS IT HAS BEEN THE MOST CONSISTENT OF LATE AND IS IN BETTER
AGREEMENT. MODEL DOES SEEM TO BE HAVING ITS USUAL FEED BACK CONCERNS
SO WILL NOT GO QUITE AS HEAVY ON THE PRECIPITATION AMOUNTS AND LEAN
TOWARDS THE MORE REALISTIC NAM FOR ACTUAL RAINFALL.

NORTHERN STREAM CONTINUES TO BE VERY ACTIVE THIS PERIOD. THE SEMI
PERMANENT UPPER RIDGE THAT HAS BEEN OVER THE SOUTHERN TIER OF THE
COUNTRY CONTINUES TO BE FLATTENED OUT BY VIGOROUS SHORT WAVE TROF
MOVING THROUGH THE NATIONS MIDSECTION. TROF EXPECTED TO DEEPEN AND
TAKE ON MORE A NEGATIVE TILT AS IT RACES OFF TO THE EAST.

SURFACE COLD FRONT ASSOCIATED WITH THIS FEATURE CURRENTLY LOCATED
IN SOUTHEAST KANSAS AND IS PRECEDED BY A PREFRONTAL TROF THAT WILL
EVENTUALLY BE TAKEN OVER BY THE ADVANCING FRONT. ATMOSPHERE THAT WAS
STRONGLY CAPPED THIS MORNING WILL BE ERODED BY STRONG INSOLATION
WITH CONVECTION LIKELY BREAKING OUT LATE THIS AFTERNOON AND EVENING
ALONG AND BEHIND THE BOUNDARY WHERE BEST MOISTURE POOLS. THERE IS A
SLIGHT CHANCE OF SEVERE WEATHER EARLY THIS EVENING AS ATMOSPHERE
WILL RAPIDLY DESTABILIZE WITH SB CAPES NEAR 2000 J/KG.

FRONT ITSELF WILL SWEEP THROUGH THE STATE QUICKLY WITH BEST
PRECIPITATION CHANCES OCCURRING DURING THE OVERNIGHT HOURS. BEST
DYNAMICS WITH THIS SYSTEM WILL BE LOCATED WELL TO THE NORTHEAST BUT
SCATTERED POPS ARE STILL WARRANTED AREA WIDE WITH MODELS SHOWING
DECENT SURFACE CONVERGENCE AND ENHANCED LIFT AND SOME JET DYNAMICS
TYAT DO COME INTO PLAY.

BY THE TIME THURSDAY MORNING ROLLS AROUND...THE FRONT WILL BE
LOCATED OVER THE EXTREME SOUTH WITH A LINGERING CHANCE OF SHOWERS
THERE. THE REMAINDER OF THE CWA WILL BE DRY.

ONCE THE FRONT PASSES...HIGH PRESSURE WILL BUILD INTO THE REGION TO
BRING SOME OF THE COOLEST AIR WE HAVE SEEN IN QUITE A WHILE. IN FACT
TEMPERATURES ACROSS THE BOARD WILL ONLY TOP OUT IN THE UPPER 60S TO
MID 70S. AFTER A COOL START TO THE DAY ON FRIDAY....TEMPERATURES
WILL BEGIN A SLOW MODERATION AS THE HIGH SLIPS OFF TO THE EAST AND
WINDS VEER TO THE SOUTHEAST. FWC/MAV IN GENERAL AGREEMENT AND WILL
GO WITH A BLEND OF NUMBERS.

WHILE ALL THIS IS GOING ON...A CLOSED OFF UPPER LOW IN THE SOUTHERN
STREAM WILL SLOWLY ADVANCE TOWARDS THE AREA. FEATURES DOES WEAKEN
WITH TIME AS IT APPROACHES THE MID SOUTH OVER THE WEEKEND. BY THE
TIME IT ARRIVES....UPPER LEVEL HIGH PRESSURE WILL BE EXPANDING OVER
THE SOUTHEAST CONUS AND WILL EFFECTIVELY PUSH THE SYSTEM TO NORTH.
ONLY AN INCREASE IN CLOUDS IS EXPECTED FROM THIS SYSTEM.

LONG TERM...SUNDAY NIGHT THROUGH WEDNESDAY
BY EARLY SUNDAY NIGHT...MOISTURE WILL BE LIMITED. HIGH PRESSURE WILL
PREVAIL. AND TEMPERATURES WILL BE A FEW DEGREES ABOVE NORMAL
THROUGHOUT THE PERIOD.

&&

.LZK WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

57

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE LITTLE ROCK AR
415 PM CDT WED SEP 28 2005

ARZ016-031>034-013-037-052-039-056-057-054-055-015-012-062-063-
038-067-066-065-064-069-068-025-005-004-007-042-003-041-040-043-
024-045-044-047-046-014-021-023-030-053-006-022-291000-
INDEPENDENCE-CONWAY-FAULKNER-WHITE-WOODRUFF-SEARCY-SCOTT-PIKE-
PERRY-JEFFERSON-ARKANSAS-HOT SPRING-GRANT-IZARD-NEWTON-DALLAS-
CLEVELAND-YELL-CALHOUN-OUACHITA-DESHA-LINCOLN-DREW-BRADLEY-
JACKSON-BAXTER-MARION-SHARP-GARLAND-BOONE-MONTGOMERY-POLK-SALINE-
CLEBURNE-LONOKE-PULASKI-MONROE-PRAIRIE-STONE-JOHNSON-VAN
BUREN-LOGAN-CLARK-FULTON-POPE
415 PM CDT WED SEP 28 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR A LARGE PART OF ARKANSAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT

A STRONG COLD WILL CONTINUE TO MOVE ACROSS THE REGION LATE THIS
AFTERNOON AND TONIGHT...BRINGING A CHANCE OF SHOWERS AND
THUNDERSTORMS WITH IT.

THE FRONT WILL ENTER THE NORTHWEST CORNER OF THE STATE EARLY THIS
EVENING AND MOVE SOUTHEAST QUITE QUICKLY...REACHING THE SOUTHERN
BORDER BY MORNING. THE FRONT WILL BE PLOWING INTO A VERY WARM AND
UNSTABLE AIR MASS WITH SHOWERS AND THUNDERSTORMS DEVELOPING ALONG
IT.

SOME OF THE THUNDERSTORMS COULD BE STRONG TO POSSIBLY SEVERE THIS
EVENING. THE BEST CHANCES OF SEVERE WEATHER WILL BE OVER THE WESTERN
AND CENTRAL PARTS OF THE STATE. A SEVERE THUNDERSTORM WATCH REMAINS
IN EFFECT UNTIL 11 PM THIS EVENING FOR A LARGE PORTION OF WESTERN
ARKANSAS. STRONG GUSTY WINDS AND LARGE HAIL WILL BE THE PRIMARY
CONCERN. THE TORNADO THREAT APPEARS TO BE MINIMAL AT THIS TIME BUT
CAN NOT BE RULED OUT. THE FRONT WILL BE MOVING FAST ENOUGH THAT
HEAVY RAIN DOES NOT APPEAR LIKELY.

THE LINE OF THUNDERSTORMS ASSOCIATED WITH THE FRONT WILL BE RATHER
NARROW BUT STILL SWEEP THROUGH THE STATE DURING THE OVERNIGHT
HOURS. SHOWERS AND THUNDERSTORMS WILL MOVE FROM NORTHWEST TO
SOUTHEAST DURING THE NIGHT WITH THE PRECIPITATION ENDING BY MID
EVENING OVER THE NORTHWEST AND OVER THE SOUTHEAST AROUND SUNRISE.

.DAY TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

HIGH PRESSURE WILL MOVE ACROSS THE STATE IN THE WAKE OF THE COLD
FRONT. COOLER AND DRIER AIR SHOULD KEEP TEMPERATURES CLOSE TO NORMAL.

.SPOTTER ACTIVATION STATEMENT...

SPOTTERS MIGHT BE ACTIVATED AS THE COLD FRONT MOVES THROUGH THE
STATE.

&&

FOR THE LATEST GRAPHICAL AND TEXT FORECASTS AND OUTLOOKS...PLEASE
VISIT OUR WEBSITE AT HTTP://WWW.SRH.WEATHER.GOV/LZK

56

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LITTLE ROCK AR
629 PM CDT WED SEP 28 2005

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

0540 PM     TSTM WND DMG     5 N PARIS               35.36N 93.72W
09/28/2005                   LOGAN              AR   EMERGENCY MNGR

            TREES DOWN.

0609 PM     TSTM WND DMG     WALDRON                 34.90N 94.09W
09/28/2005                   SCOTT              AR   LAW ENFORCEMENT

            TREES AND POWER LINES DOWN ALL OVER THE CITY.

&&

57