Severe Thunderstorm Warning 374, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
230 PM CDT MON JUN 19 2000

LOOKS LIKE THE MUCH NEEDED RAINS WILL BE TAPERING OFF FOR AWHILE.
FIRST...LET/S TAKE A LOOK AT WHAT IS. MORNING UPPER AIR RUNS...ALONG
WITH WATER VAPOR LOOP...SHOWS UPPER RIDGE HAS SHIFTED A BIT FARTHER
NORTH...RUNNING FROM THE DEEP SOUTH INTO MEXICO AND POINTS WEST.
THIS SHIFT IS IN RESPONSE TO A BROAD TROUGH CROSSING EASTERN
CN/NORTHEASTERN US AND SHARP TROUGH HEADING INTO THE NORTHERN US/CN
ROCKIES REGION. SHARP RIDGE WAS ANALYZED OVER THE CENTRAL AND
NORTHERN US PLAINS AND CN PLAINS. WEAK LOW OVER THE SOUTHERN GULF
AND EASTERN CARIBBEAN SEA IN EVIDENCE ALONG WITH SEVERAL OTHER
SHORTWAVES MEANDERING AROUND OVER THE SOUTHERN US. IN THE LOWER
LEVELS...AS EASTERN TROUGH MOVES EAST...SOUTHERLY FLOW OVER CENTRAL
PLAINS TAKING OVER...PUSHING THE TAIL END OF BOUNDARY(STRETCHING
FROM THE CENTRAL PLAINS INTO NEW ENGLAND) NORTH AND MIXING IT OUT.
STILL HAVE GOOD LOW LEVEL SOUTHERLY FLOW INTO THE CENTRAL
PLAINS...BUT LOW LEVEL FLOW OVER THE LOWER MISSISSIPPI RIVER VALLEY
HAS WEAKENED...AS EVIDENCED BY LOW LEVEL WINDS  15KTS OR LESS ON
MORNING KJAN SOUNDING AND NOONTIME VAD WINDS OF 10KTS OR LESS. STILL
HAVE GOOD...DEEP MOISTURE(PRECIP H20 AMOUNTS 1.75-2.00"+ OVER
SOUTHERN MISS RIVER VALLEY) OVER THE FA...WITH VERY UNSTABLE
CONDITIONS(FIRST STORMS FIRED UP WITH INITIATION OF GULF BREEZE
ALONG COAST).

MODELS ADVERTISING A BIT OF A BATTLE BETWEEN SOUTHERN US RIDGE AND
SHORTWAVE(DEEPENING INTO CLOSED LOW OVER SOUTHERN MANITOBA BY
F36/TUES EVENING). FROM THERE...NGM TAKES LOW ON A SOUTHEASTERLY
PATH WHILE ETA/AVN MEANDER IT SLOWLY EASTWARD. DIFFERENCES ALSO
ARISE IN NEXT PUSH OF COOLER AIR INTO THE PLAINS...WITH NGM/AVN
PUSHING FRONT INTO NORTHWESTERN AR BY F48/WED MORN. ETA SLOW WITH
FRONT...KEEPING IT ABOUT 100 MILES BEHIND OTHER TWO. ETA BY F60/WED
EVENING HAS FRONT BECOMING STATIONARY OVER NORTHERN AR/TN WITH AVN
DIPPING THE BOUNDARY FARTHER SOUTH. MODELS ALSO DIFFER WITH DRY AIR
PUSH IN THE MID/UPPER LEVELS WITH ETA MOST AGGRESSIVE WITH DRY
PUSH...AVN LEAST. PUSH LOOKS TO BECOME SIGNIFICANT BEGINNING
F24/TUES MORN. AFTER TAKING A LOOK AT THE WATER VAPOR LOOP...BELIEVE
THERE WILL BE SOME DRYING. QUESTION WILL BE.. HOW MUCH MOISTURE WILL
THE SYSTEM OVER THE EASTERN CARIBBEAN PUMP INTO THE GULF. AVN
HINTING AT NEXT ROUND OF PRECIP THURSDAY.

WELL...GOING TO CUT BACK THE POPS A BIT MORE. HESITANT TO TAKE THEM
OUT ENTIRELY...WITH DECENT LOW LEVEL MOISTURE STILL HANGING AROUND.
WILL PUT IN BEST POPS SOUTH...WHERE GULF BREEZE ACTION LOOKS TO BE
THE INITIATOR OF ACTIVITY OVER THE NEXT SEVERAL DAYS.

QPF DISCUSSION:WITH AFTERNOON HEATING AND PW'S ~ 2.0 INCHES...
SCATTERED SHOWERS AND THUNDERSTORMS WILL PRODUCED ISOLATED HEAVY
RAINFALL. THEREFORE BASIN AVERAGES WILL BE LESS THAN A QUARTER INCH
FOR THE 24 HR PERIOD. WILL HAVE THE GREATEST AMOUNTS ALONG AND SOUTH
OF I-20. ELSEWHERE...AMOUNTS WILL BE EQUAL ARE LESS THAN ONE TENTH
OF AN INCH.

IN THE EXTENDED...USUAL CHAOS RULES WITH THE MEDIUM RANGE MODELS.
OVER THE FA...ALL HAVE NEXT TROUGH SWINGING THROUGH SOUTHERN
CN...PUTTING A DENT INTO RIDGE OVER GULF. MRF PUSHES FRONT INTO
SOUTHERN SECTIONS OF THE FA BEFORE STALLING IT FRIDAY. NOGAPS
FOLLOWS MRF. UKMO AND ECMWF LEAVE BOUNDARY OVER TN. WITH BETTER
MOISTURE LOOKING TO BE BACK...WILL CONTIVNUE WIDELY SCATTERED TO
SCATTERED AFTERNOON/EVENING SHRA/TSRA WITH TEMP NEAR NORM.

PRELIM NUMBERS...
JAN 071/090 071/091 070 2323
MEI 070/091 070/091 069 3323

.JAN...
MS...NONE.
AR...NONE.
LA...NONE.

16/05

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
200400-

AREA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
950 AM CDT MON JUN 19 2000

A MOIST AIR MASS REMAINS IN PLACE ACROSS THE REGION TODAY. AS
DAYTIME HEATING OCCURS...SCATTERED SHOWERS AND THUNDERSTORMS WILL
DEVELOP WITH THE POTENTIAL FOR LOCALLY HEAVY RAINFALL.
HOWEVER...SEVERE WEATHER IS NOT EXPECTED.

ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS...AND EMERGENCY
MANAGEMENT PERSONNEL SHOULD NOT BE NEEDED THROUGH TONIGHT.

FOR MORE INFORMATION...PLEASE VISIT OUR INTERNET WEB SITE AT
HTTP://WWW.SRH.NOAA.GOV/JAN WHICH INCLUDES AN EXPERIMENTAL GRAPHICAL
HAZARDOUS WEATHER OUTLOOK.