Severe Thunderstorm Warning 340, NWS Little Rock, AR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LITTLE ROCK AR
330 AM CDT THU JUL 20 2000

INTERESTING WEATHER PATTERN SETTING UP FOR THE NEXT FEW DAYS.
THE LATEST SURFACE MAP HAS A QUASI-STATIONARY FRONT FROM JUST NORTH
OF KFSM THROUGH TO JUST NORTH OF KLIT TO NEAR KGWO. POOLING
DEWPOINTS OF NEAR 75 DEGREES ARE ACROSS MUCH MY CWFA. LATEST LOW
CLOUD/FOG SATELLITE LOOP SHOWS SOME CLOUDS COMING INTO NORTH CENTRAL
ARKANSAS. IR LOOP SHOWS AN MCS OVER KS...MOVING SOUTHEAST.IN THE
UPPER LEVELS...THERE IS THE PESKY UPPER LEVEL RIDGE OVER THE SOUTH
CENTRAL US WITH A TROUGH ACROSS THE EAST.

THE MID AND UPPER LEVEL PATTERN ACROSS THE CONUS BECOMES MORE
AMPLIFIED THROUGH TIME WITH THE UPPER LEVEL HIGH BUILDING INTO THE
ROCKIES AND A CLOSED LOW MOVING ACROSS NEW ENGLAND. THIS PATTERN
WILL KEEP AR IN DANGEROUS NORTHWEST FLOW OVER THE NEXT FEW DAYS. I
USED A COMPOSITE OF THE ALL THREE SHORT RANGE MODELS FOR THE OVERALL
SYNOPTIC FEATURES. I REALLY DIDN/T FOLLOW THE TIMING ON THE MCS
CLOSELY WITH ANY MODELS...SINCE THEY DON/T HANDLE THEM WELL.
OVERALL...JUST A WET PATTERN.

AT THE SURFACE...THE FRONT SHOULD SINK A BIT FURTHER TO THE SOUTH
INTO SOUTHERN AR OR NORTHERN LA THE WEEKEND AND WILL CONTINUE TO BE
THE FOCUSING MECHANISM FOR SHOWERS AND THUNDERSTORMS. SEVERE WEATHER
PARAMETERS ARE COMING TOGETHER FOR TODAY...REF MKCSWODY1. I WILL
THEREFORE MENTION A FEW POSSIBLY SEVERE FOR TODAY AND TONIGHT.

IN TERMS OF PRECIPITATION...I WENT WITH HIGHER POPS FOR TODAY COMPARED
TO THE FWC/FAN AND THEN WENT PRETTY CLOSE TO THEM FORM THE REMAINDER
OF THE SHORT TERM PERIOD ACROSS THE NORTH. I CONTINUED THE TRENDS OF
GOING SLIGHTLY ABOVE THE FWC/FAN MOS NUMBERS ACROSS THE CENTRAL AND
THE SOUTH. OVERALL...HIGH CHANCE TO LIKELY FOR THE FIRST THREE
PERIODS ACROSS THE NORTH WITH LOWER CHANCES ACROSS THE SOUTH.

IN TERMS OF TEMPERATURES...I WENT AT OR SLIGHTLY ABOVE THE FWC/FAN
NUMBERS THROUGH THE PERIOD.

WITH THE WARMING OF THE LAST FWC MOS GUIDANCE AND EVEN THINKING THAT
AS MAYBE SLIGHTLY TOO COOL...I WILL EXPAND THE HEAT ADVISORY BACK
INTO MUCH OF THE CENTRAL THIRD OF ARKANSAS FOR TODAY. I WILL ALSO
EXTEND THE HEAT ADVISORY ACROSS THE SOUTH INTO FRIDAY. HEAT INDEX
VALUES SHOULD GENERALLY BE BETWEEN 105 AND 115 THIS AFTERNOON AND
BETWEEN 105 AND 110.

...EXTENDED...
NO CHANGES TO THE EXTENDED.

(49)

.LIT...HEAT ADVISORY TODAY FOR THE SOUTHERN TWO-THIRDS OF FA
       ZONES 21>22-30>32-37>47-52>57-62>69
       HEAT ADVISORY FRIDAY EXTREME SOUTH PART OF FA
       ZONES 052-053-062>069



ARZ003>007-012>016-021>025-030>034-037>047-052>057-062>069-201830-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LITTLE ROCK AR
449 AM CDT THU JUL 20 2000

...SLIGHT RISK OF SEVERE WEATHER LATER TODAY...

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

A COLD FRONT WHICH MOVED INTO THE STATE LAST NIGHT HAS BECOME NEARLY
STATIONARY FROM NORTHWEST TO SOUTHEAST ACROSS ARKANSAS. EARLY THIS
MORNING...THE FRONT WAS LOCATED FROM NEAR FAYETTEVILLE...TO
LITTLE ROCK TO NEAR MONTICELLO. AN AREA OF LOW PRESSURE ALOFT OVER
KANSAS THIS MORNING WILL DROP SOUTHEAST INTO THE REGION AND INTERACT
WITH THE FRONT LATER TODAY AND TONIGHT. VERY UNSTABLE AIR WILL ALSO
BE IN PLACE ALONG THE STATIONARY FRONT...WHICH WILL AID IN
THUNDERSTORM DEVELOPMENT.

THE PRIMARY THREAT FROM THESE THUNDERSTORMS WILL BE DAMAGING WINDS...
HAIL AND LOCALLY HEAVY RAINFALL. IN ADDITION...WIND FIELDS ALOFT
SUGGEST THE POSSIBILITY OF ISOLATED TORNADOES.

STORM SPOTTERS...AMATEUR RADIO OPERATORS AND EMERGENCY MANAGEMENT
PERSONNEL MAY BE NEEDED FOR ACTIVATION LATER TODAY AND TONIGHT.

FOR ADDITIONAL WEATHER INFORMATION FROM THE NATIONAL WEATHER SERVICE
IN LITTLE ROCK...CHECK OUT OUR WEB SITE AT
HTTP://WWW.SRH.NOAA.GOV/LZK

45

ARZ003>007-012>016-021>025-030>034-037>047-052>057-062>069-201830-

SEVERE WEATHER OUTLOOK...CORRECTED PRODUCT NAME
NATIONAL WEATHER SERVICE LITTLE ROCK AR
449 AM CDT THU JUL 20 2000

...SLIGHT RISK OF SEVERE WEATHER LATER TODAY...

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

A COLD FRONT WHICH MOVED INTO THE STATE LAST NIGHT HAS BECOME NEARLY
STATIONARY FROM NORTHWEST TO SOUTHEAST ACROSS ARKANSAS. EARLY THIS
MORNING...THE FRONT WAS LOCATED FROM NEAR FAYETTEVILLE...TO
LITTLE ROCK TO NEAR MONTICELLO. AN AREA OF LOW PRESSURE ALOFT OVER
KANSAS THIS MORNING WILL DROP SOUTHEAST INTO THE REGION AND INTERACT
WITH THE FRONT LATER TODAY AND TONIGHT. VERY UNSTABLE AIR WILL ALSO
BE IN PLACE ALONG THE STATIONARY FRONT...WHICH WILL AID IN
THUNDERSTORM DEVELOPMENT.

THE PRIMARY THREAT FROM THESE THUNDERSTORMS WILL BE DAMAGING WINDS...
HAIL AND LOCALLY HEAVY RAINFALL. IN ADDITION...WIND FIELDS ALOFT
SUGGEST THE POSSIBILITY OF ISOLATED TORNADOES.

STORM SPOTTERS...AMATEUR RADIO OPERATORS AND EMERGENCY MANAGEMENT
PERSONNEL MAY BE NEEDED FOR ACTIVATION LATER TODAY AND TONIGHT.

FOR ADDITIONAL WEATHER INFORMATIO,N FROM THE NATIONAL WEATHER SERVICE
IN LITTLE ROCK...CHECK OUT OUR WEB SITE AT
HTTP://WWW.SRH.NOAA.GOV/LZK

45