Severe Thunderstorm Warning 83, NWS Little Rock, AR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LITTLE ROCK AR
339 AM CST SUN MAR 26 2000

LATEST SURFACE ANALYSIS HAS A COLD FRONT MOVING ACROSS THE EASTERN
TN VALLEY AND THEN STALLING OUT ACROSS CENTRAL MS. THE FRONT IS THEN
QUASI-STATIONARY FROM CENTRAL MS THROUGH SOUTHWESTERN AR AND TO A
WEAK SURFACE LOW IN SOUTHWEST OK. A WEAK BUBBLE HIGH WAS LOCATED
ACROSS SOUTHEASTERN MO WITH DEWPOINTS BETWEEN 35 AND 45 DEGREES.
LATEST SATELLITE IMAGERY INDICATES TWO LARGE AREAS OF SHOWERS AND
THUNDERSTORMS ACROSS LA AND NORTH CENTRAL TX. THESE THUNDERSTORMS
ARE CURRENTLY MOVING SOUTHEASTWARD AND AWAY FROM MY AREA.

IN THE UPPER LEVELS...QUASI-ZONAL FLOW REMAINED OVER AR WITH SEVERAL
WEAK SHORT WAVES BETWEEN MS...TN AND THEN INTO LA AND TX. THERE IS A
DEEP CLOSED LOW TO THE NORTH OF LAKE SUPERIOR WITH A TROUGH DROPPING
THROUGH THE GREAT LAKES...THE OHIO VALLEY AND INTO THE NORTHEASTERN
PART OF THE STATE. THE QUASI-ZONAL FLOW OVER AR SPREADS WESTWARD
ACROSS MUCH OF THE WESTERN HALF OF THE STATE AND A DEEP CLOSED LOW
IS LOCATED WELL OFF INTO THE PACIFIC.

THE MODELS ARE IN OVERALL AGREEMENT WITH THE GENERAL SYNOPTIC
FEATURES AND HAVE INITIALIZED WELL. THE AVN WAS TO QUICK WITH THE
THROUGH OVER THE EASTERN PACIFIC AND IT HAS BEEN DISCOUNTED IN
PARTICULAR AFTER 24 HOURS. BY 24 HOURS...THE FIRST CLOSED LOW HAS
PUSHED TO THE NORTH OF NEW ENGLAND WITH THE TROUGH WELL OFF TO THE
EAST. A SECOND CLOSED LOW WILL BE MOVING SOUTHEASTWARD OUT OF
CENTRAL CANADA. IT WILL HAVE A TROUGH EXTENDING DOWN THROUGH THE
CENTRAL PLAINS. THE CLOSED LOW OUT OVER THE PACIFIC REMAINS NEARLY
STATIONARY.

THE TROUGH OVER THE CENTRAL PLAINS WILL MOVE THROUGH THE STATE AND
INTO THE OH AND TN VALLEYS CREATING STRONG NORTHWEST FLOW OVER THE
STATE BY 48 HOURS. THE CLOSED LOW ASSOCIATED WITH THIS TROUGH WILL
CONTINUE TO DEEPEN AND MOVE SOUTHEASTWARD INTO THE GREAT LAKES.
RIDGING WILL BUILD ACROSS THE FRONT RANGE OF THE ROCKIES AHEAD OF
THE EASTERN PACIFIC TROUGH. THE CLOSED LOW WEAKENS INTO A TROUGH AND
HEAD TOWARD THE BAJA PENINSULA.

THE SHORT WAVE...WHICH IS LOCATED OVER WEST TX SATURDAY EVENING...WILL
MOVE EASTWARD AND WILL BE WELL TO OUR EAST BY THIS MORNING. IT WILL
SPREAD SOME MOISTURE BACK INTO THE AREA...BUT LATEST SATELLITE
TRENDS INDICATE THAT THE THUNDERSTORMS ACTIVITY WITH IT WILL STAY
WELL TO THE SOUTH OF MY CWFA FOR THE MORNING. A SECOND SHORT WAVE
WILL DROP OUT OF THE PLAINS STATES THIS AFTERNOON AND SPREAD MORE
MOISTURE BACK INTO THE STATE. THE MODELS QUICKLY DRY US OUT...BEHIND
THE SHORT WAVE ON MONDAY.

AT THE SURFACE...ALL OF THE MODELS MOVE THE BUBBLE HIGH EASTWARD
FROM SOUTHEASTERN MO INTO THE OH VALLEY TODAY. THIS WILL ALLOW THE
QUASI-STATIONARY FRONT...OVER SOUTHWESTERN AR TO MOVE NORTHEASTWARD
...AS A WARM FRONT TODAY. THE WARM FRONT WILL PROBABLY MAKE THROUGH
MOST OF THE STATE TODAY. A COLD FRONT WILL THEN APPROACH THE STATE
THIS EVENING AND MOVE THROUGH THE STATE TONIGHT. ANOTHER BUBBLE HIGH
PRESSURE WILL BUILD INTO THE AREA QUICKLY FOR MONDAY.

IN TERMS OF PRECIPITATION...ALTHOUGH LATEST SATELLITE IMAGERY SHOWS
MUCH OF THE THUNDERSTORM ACTIVITY WILL STAY SOUTH OF THE STATE THIS
MORNING. I WILL NOT USE TIMING PHRASEOLOGY WITH THE FRONT MOVING
BACK NORTHWARD...AS A WARM FRONT AND WITH THE MOISTURE AND
INSTABILITY AROUND. I WENT CLOSE TO THE FWC MOS NUMBERS FOR CHANCES
THROUGHOUT THE PERIOD. THIS GIVES MAINLY HIGH CHANCE POPS (50%)
TODAY. THE HIGH CHANCE POPS WILL CONTINUE FOR TONIGHT ACROSS THE
WESTERN THIRD OF MY CWFA WITH LIKELY POPS (60%) ACROSS THE EASTERN
TWO THIRDS. AS MENTIONED ABOVE...BOTH THE MEAN RH AND ETA AND NGM
CROSS SECTIONS INDICATE VERY LITTLE MOISTURE FOR MONDAY INTO MONDAY
NIGHT. EVEN THOUGHT ABOUT MENTIONING JUST EVENING WORDING FOR
TONIGHT...BUT I DECIDED AGAINST IT IN CASE THE TIMING OF THE FROPA
IS OFF.

IN TERMS OF TEMPERATURES...I WENT VERY CLOSE TO THE FWC MOS. SLIGHT
COOLER AND DRIER AIR WILL WORK IN FOR MONDAY AND TUESDAY.

...EXTENDED...
NEW MRF HAS A SIMILAR TIMING TO THE NGM AND ETA IN TERMS OF THE
EASTERN PACIFIC CUT OFF LOW. IT WILL MOVE INTO THE CENTRAL PLAINS BY
MID-WEEK BRINGING US WET WEATHER. CURRENT EXTENDED LOOKS GOOD AND I
WILL NOT MAKE ANY CHANGES TO THE DAY 4 AND 5 PERIODS.

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.LIT...NONE.

ARZ003>007-012>016-021>025-030>034-037>047-052>057-062>069-271200-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LITTLE ROCK AR
1240 PM CST SUN MAR 26 2000

...MODERATE RISK OF SEVERE WEATHER LATER THIS AFTERNOON AND TONIGHT...

THERE IS A MODERATE RISK OF SEVERE WEATHER ACROSS MOST OF ARKANSAS
LATER THIS AFTERNOON AND TONIGHT.

A STATIONARY FRONT LYING ACROSS SOUTHERN ARKANSAS WILL MOVE NORTH AS
A WARM FRONT THIS AFTERNOON...ALLOWING WARM...MOIST AND UNSTABLE AIR
TO SPREAD ACROSS THE STATE FROM THE GULF COAST REGION. MEANWHILE...A
FAST MOVING COLD FRONT IN THE CENTRAL PLAINS WILL APPROACH THE
NORTHWEST CORNER OF ARKANSAS BY LATE AFTERNOON...AND WILL PUSH
ACROSS THE STATE TONIGHT. THE FRONT WILL MOVE INTO AN UNSTABLE
ENVIRONMENT...WITH STRONG TO SEVERE THUNDERSTORMS EXPECTED TO
DEVELOP.

AT THIS TIME...A LINE OF STORMS IS ANTICIPATED ALONG AND AHEAD OF
THE FRONT. THE FRONT WILL ARRIVE IN NORTHWEST SECTIONS OF THE STATE
BY 6 PM OR SO...IN CENTRAL ARKANSAS BY MIDNIGHT...AND WILL EXIT
SOUTHEAST ARKANSAS BY 6 AM ON MONDAY. SHOULD THE LINE OF STORMS
DEVELOP...IT WILL HAVE THE POTENTIAL TO AFFECT A LARGE AREA.

THE MAIN SEVERE WEATHER THREATS WILL BE WIDESPREAD WIND DAMAGE...
DIME SIZE HAIL OR LARGER...AND ISOLATED TORNADOES.

BEFORE THE FRONT ARRIVES...AND THE POTENTIAL FOR SEVERE WEATHER
INCREASES...SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS
AFTERNOON AS WARM...MOIST AND UNSTABLE AIR BECOMES ESTABLISHED. A
FEW STORMS MAY BECOME SEVERE...PARTICULARLY IN NORTHERN ARKANSAS.

AS THE POTENTIAL FOR SEVERE WEATHER INCREASES...STORM
SPOTTERS...AMATEUR RADIO OPERATORS...AND EMERGENCY MANAGERS WILL
LIKELY BE ACTIVATED LATER THIS AFTERNOON AND TONIGHT.

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