Severe Thunderstorm Warning 397, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
255 PM CDT SAT JUL 15 2000

SYNOPTIC SCALE PATTERN STILL ABOUT THE SAME AS IT HAS BEEN FOR MANY
DAYS...AND AS IT WILL CONTINUE TO BE FOR MANY DAYS...WITH OUR CWFA
IN NORTHERLY FLOW ALOFT ON THE EAST SIDE OF BIG HOT RIDGE.

TEMPERATURES REMAIN THE MAIN ISSUE. HIGHS FRIDAY RANGED FROM 95 TO
102...AND WILL LIKELY REACH EVEN HIGHER THIS AFTERNOON AS DRIER AIR
IN THE UPPER PARTS OF THE MIXED LAYER HAS BEEN BROUGHT DOWN TO THE
SURFACE BY CONVECTION CURRENTS. DEWPOINTS ARE DOWN 4-7F OVER MOST OF
THE CWFA FROM 18Z FRIDAY TO 18Z TODAY...EXCEPT OVER THE DELTA
REGION. THEREFORE...HEAT INDICES ARE NOT AS BRUTAL TODAY...WITH
105-110F OVER THE DELTA AS OF 18Z AND 100-105F ELSEWHERE.

FOR THE TEMPERATURE TRENDS OF THE NEXT COUPLE OF DAYS...SEE MIXED
SIGNALS. HEIGHTS AND THICKNESSES RISE A LITTLE MORE...BUT MEAN LAYER
MOISTURE ALSO INCREASES. BELIEVE THESE WILL OFFSET EACH OTHER AND
RESULT IN A NEAR-PERSISTENCE FORECAST. WILL WEIGHT TEMP FORECASTS
HEAVILY TOWARD PLOT OF OBSERVED HIGHS FROM THU AND FRI PLUS BEST
ESTIMATE OF HIGHS TODAY BEFORE ZONE RELEASE.

PRECIP MAY ACTUALLY HAVE TO BE CONSIDERED FOR THE EASTERN THIRD OR
SO OF THE CWFA AS WELL. REMNANTS OF DAKOTAS MCS FROM LAST NIGHT
TRACKING THROUGH NRN MO EARLY THIS AFTERNOON...WITH WEAK CONVECTION
TRYING TO GET GOING ON THE LEADING EDGE OF THE OUTFLOW OVER NERN AR
AND WRN TN. THESE FEATURES SHOULD CONTINUE SOUTHEASTWARD AROUND THE
PERIPHERY OF THE RIDGE...WITH MODELS INDICATING SOME PRECIP OVER
EASTERN CWFA OVERNIGHT. BELIEVE MOST OF THIS WILL BE CLOUD
DEBRIS...BUT WILL INCLUDE SLIGHT CHANCE POPS OUT OF RESPECT FOR THE
VORT LOBE WHICH IS FORECAST TO BE CRUISING SOUTH OVER WRN AL AT THE
SAME TIME. ANTICIPATE THAT ANY LEFTOVER OUTFLOW BOUNDARIES AND/OR
DIFFERENTIAL HEATING BOUNDARIES AT EDGES OF CLOUDY AREAS WILL HELP
FOCUS ANY CONVECTION OVER THE SOUTHEAST CWFA ON SUNDAY AFTERNOON.
ALSO EXPECT CONVECTION...IF ANY...TO BE CONFINED TO THE SOUTHEAST ON
MONDAY. SLIGHT CHANCE OR LOW END CHANCE POPS SHOULD COVER IT BOTH
DAYS.

QPF DISCUSSION: WIDELY SCATTERED SHOWERS AND THUNDERSTORMS DROPPING
SEWD FROM MO RIDING ALONG A NICE LOW LEVEL THETA-E RIDGE AXIS AND
SHOULD CLIP AT LEAST NERN THIRD OF MS THIS EVENING BEFORE
DISSIPATING. PRECIPITABLE WATER VALUES BEGIN REBOUNDING SLIGHTLY
OVERNIGHT AND PUSH BACK ABOVE 1.5" ALONG A NW-SE AXIS FROM ABOUT
CLARKSDALE TO MERIDIAN ON SUNDAY. LIMITED COVERAGE OF RAINFALL
SHOULD DO VERY LITTLE TO IMPACT RIVER BASIN AVERAGES WHICH WILL BE
KEPT AT LESS THAN ONE TENTH INCH FOR THE NEXT 24 HOURS...MAINLY
FIRST AND LAST 6-HOUR PERIODS.

EXTENDED...MORE OF THE SAME THROUGH AT LEAST WEDNESDAY AS PATTERN
REMAINS ENTRENCHED. NOGAPS SHOWS SOME PROMISE OF MORE WIDESPREAD
RAIN ON THURSDAY AS ANOTHER BOUNDARY IS PUSHED OUR WAY IN THE
NORTHERLY FLOW AND HELPS TO FOCUS THINGS. AM NOT WILLING TO JUMP ON
THIS SCENARIO SO FAR OUT IN TIME...BUT DO BELIEVE THAT ISOLATED
AFTERNOON/EVENING STORMS SHOULD BE MENTIONED ALL THREE DAYS IN THE
EXTENDED. WITH SUCH EXTREME HEAT AND NORTHERLY FLOW...WHICH HAS BEEN
KNOWN TO HOLD SURFPRISES...AM NOT COMFORTABLE WITH A COMPLETELY DRY
FORECAST.

JAN 069/100 070/100 000
MEI 068/102 069/102 121

.JAN...
AR...NONE.
LA...NONE.
MS...NONE.
06/40