Area Forecast Discussion
Issued by NWS Jackson, MS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
000
FXUS64 KJAN 290220 AAA
AFDJAN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
920 PM CDT THU APR 28 2016

.UPDATE...
THE BOUNDARY NOW HANGS ACROSS THE AREA KIND OF ALONG THE NATCHEZ
TRACE CORRIDOR. THE MAJORITY OF THE CLOUDS HAVE DIMINISHED AND TEMPS
ARE IN THE LOW/MID 70S. AFTER PERUSING THE HI-RES MODELS, HAVE BACKED
OFF ON RAIN CHANCES TIL AFTER 12Z. ONLY ADJUSTED THE POPS FOR THIS
UPDATE. TEMPS LOOK GOOD. /10/

&&

.AVIATION...
SATELLITE IMAGERY ONLY SHOWED A FEW CLOUDS ALONG THE HWY 84 CORRIDOR
AT 02Z. VFR CONDITIONS WL CONTINUE UNTIL AFTER 09Z. AFTER 09Z MVFR
CIGS WL DEVELOP AND LOWER TO IFR CNTRL AND SOUTH. LIFR CONDS ARE PSBL
AT HBG. CONDITIONS WL IMPROVE BY 15Z BUT TSRA/SHRA ACTIVITY WL COME
IN VCTY OF GLH AND GWO THEN. /22/

&&

.PREV DISCUSSION... /ISSUED 346 PM CDT THU APR 28 2016/

DISCUSSION...TONIGHT THROUGH FRIDAY NIGHT...AN ISOLATED SHOWER
OR STORM CAN`T BE RULED OUT LATE THIS AFTERNOON...BUT THIS ACTIVITY
WILL DISSIPATE AROUND SUNSET.  FOR TONIGHT...QUIET CONDITIONS ARE
EXPECTED THROUGH THE MAJORITY OF THE PERIOD AS A BOUNDARY IS
EXPECTED TO BEGIN LIFTING NORTH THROUGH THE REGION. THIS WILL ALLOW
MOISTURE TO AGAIN BEGIN INCREASING ACROSS THE REGION OVERNIGHT.  LOW
CLOUDS WILL ALSO INCREASE OVERNIGHT FROM SOUTH TO NORTH IN THE WAKE
OF THIS NORTHWARD LIFTING BOUNDARY...WITH AT LEAST SOME PATCHY FOG
POSSIBLE ACROSS MAINLY SOUTHEAST MISSISSIPPI EARLY FRIDAY MORNING.
LOWS TONIGHT WILL BE MILD AS THEY SLIP INTO THE LOW AND MIDDLE 60S.

AFTER THE TONIGHT PERIOD...CONFIDENCE IN HOW THE FORECAST WILL
EXACTLY PAN OUT FOR FRIDAY IS RUNNING A BIT ON THE LOW SIDE THIS
AFTERNOON.  CURRENTLY...IT APPEARS THE AFOREMENTIONED BOUNDARY WILL
HANG UP ACROSS TO JUST NORTH OF THE CWA ON FRIDAY. BY FRIDAY
MORNING...A DISTURBANCE ALOFT IS PROGGED TO SEND A COMPLEX OF STORMS
EAST NORTHEAST ALONG THIS BOUNDARY...OUT OF THE ARKLATEX AND TOWARDS
THE MID-SOUTH REGION...POSSIBLE CLIPPING THE NORTHWEST HALF OF THE
ARKLAMISS IN THE PROCESS.  AS THIS OCCURS...SOME MODELS INDICATE
THIS COMPLEX COULD LAYOUT AN OUTFLOW BOUNDARY THAT HANGS UP NEAR THE
HIGHWAY 82 CORRIDOR.

THIS BOUNDARY...IN ADDITION TO ADEQUATE WIND SHEAR OVER THE AREA...
AND DAYTIME HEATING RESULTING IN AMPLE INSTABILITY WITH SOME DECENT
MID-LEVEL LAPSE RATES...COULD RESULT IN THE POTENTIAL FOR SOME
SEVERE STORMS ACROSS PORTIONS OF THE DELTA REGION AND NORTH CENTRAL
MISSISSIPPI.  THE MOST INTENSE STORMS WILL BE CAPABLE OF PRODUCING
SOME DAMAGING WIND GUSTS AND HAIL.  IN ADDITION...THE WEST TO EAST
ORIENTATION OF THE BOUNDARY AND EXPECTED STORM MOTION...COUPLED WITH
DEEP AND INCREASING MOISTURE OVER THE AREA...COULD RESULT IN
CONVECTION PRODUCING HEAVY RAINFALL AND TRAINING ACROSS THE SAME
LOCALES OVER PORTIONS OF THE DELTA REGION AND NORTH CENTRAL
MISSISSIPPI.  THIS COULD LEAD TO SOME LOCALIZED FLASH FLOODING OVER
THESE AREAS. THEREFORE...IN ADDITION TO THE ONGOING "LIMITED THREAT"
FOR SEVERE STORMS IN THE HWO OVER MY NORTHWEST FRIDAY...A "LIMITED
THREAT" FOR FLOODING WAS ADDED TO THE HWO THIS AFTERNOON.  FURTHER
ACROSS THE CENTRAL AND SOUTH PORTIONS OF THE CWA...WHILE SOME RAIN
CHANCES EXISTS...THAT`LL BE MORE OF THE ISOLATED TO SCATTERED
VARIETY AS A CAPPING INVERSION CURRENTLY LOOKS MORE PROMINENT ACROSS
THESE AREAS.

THERE ARE A COUPLE OF FAIL-SAFES THAT COULD LESSEN THE CHANCES OF
THE ABOVE SCENARIOS OCCURRING.  ONE COULD BE A CAPPING INVERSION
THAT`S PROGGED TO BE OVER THE CWA LIMITING OVERALL DEVELOPMENT OF
CONVECTION.  THE OTHER BEING DEBRIS OFF THE PREVIOUS MENTIONED
EXPECTED COMPLEX LIMITING BOTH HEATING AND INSTABILITY OVER THE
AREA...AND/OR THE OUTFLOW OFF THIS SAME COMPLEX TRAVERSING THE
REGION ENTIRELY AND EARLY ENOUGH THAT IT STABILIZES OUR AIRMASS IN
TIME FOR THE AFTERNOON.

HOW THINGS DEVELOP UPSTREAM OF THE FORECAST AREA OVERNIGHT...WILL
ESSENTIALLY MAKE OR BREAK THE FORECAST FOR FRIDAY.  THE LATEST
SATELLITE AND RADAR DATA TO OUR WEST WILL BE MONITORED VERY CLOSELY
OVERNIGHT TO SEE HOW THINGS DEVELOP.

A LULL IN ACTIVITY COULD EXIST FOR AT LEAST THE FIRST HALF OF FRIDAY
EVENING...BUT RAIN CHANCES LOOK TO INCREASE ONCE AGAIN HEADING INTO
SATURDAY MORNING WHEN YET ANOTHER DISTURBANCE BEGINS IMPEDING UPON
THE WESTERN HALF OF THE FORECAST AREA. /19/

SATURDAY THROUGH WEDNESDAY...THE EXTENDED PORTION OF FORECAST WILL
FEATURE OFF AND ON RAIN/STORM CHANCES THROUGH THE WEEKEND, WITH
DRYING CONDITIONS BY THE MIDDLE OF NEXT WEEK.

THIS WEEKEND, BROAD UPPER TROUGHING OVER THE WESTERN 2/3RDS OF THE
COUNTRY WILL FINALLY BEGIN TO BREAK DOWN AS A MID LEVEL SHORTWAVE
OVER THE PLAINS EJECTS EASTWARD THROUGH THE MIDWEST AND OFF THE
ATLANTIC COAST BY MONDAY. OUR AREA WILL BEGIN THE PERIOD IN A
WARM/MOIST SOUTHERLY LOW LEVEL FLOW REGIME, WITH A COLD FRONT WELL
WEST OF THE AREA ACROSS THE GREAT PLAINS. ON SATURDAY MORNING A
CONVECTIVE COMPLEX (REMNANT FROM DEVELOPMENT WEST OF THE AREA ON
FRIDAY) IS EXPECTED TO APPROACH THE CWA AS A SHORTWAVE MOVES ACROSS
THE MIDSOUTH. THIS FEATURE COULD COMPLICATE THE FORECAST FOR THE
REMAINDER OF THE DAY (SIMILAR TO YESTERDAY`S SCENARIO). OUTSIDE OF
THE FEATURE, MOST GUIDANCE SHOWS LITTLE ACTIVITY ACROSS THE
REMAINDER OF THE CWA DURING THE DAYTIME HOURS, WITH MORE OF AN
INCREASE IN COVERAGE LATER IN THE EVENING AS STRENGTHENING UPPER
DIVERGENCE MOVES OVER THE REGION. THROUGH THE DAY, UPPER FORCING/LLJ
ARE EXPECTED TO DECREASE, WITH MID LEVEL HEIGHTS RISING IN MANY
AREAS. ANY STRONG STORMS WOULD BE DRIVEN LARGELY BY INSTABILITY,
THOUGH DEEP LAYER SHEAR SHOULD ALSO BE SUFFICIENT FOR SOME STRONG
STORMS. GIVEN SHAKY CONFIDENCE ON EVOLUTION OF ACTIVITY SATURDAY, NO
CHANGES WILL BE MADE TO THE CURRENT LIMITED THREAT AREA HIGHLIGHTED
IN THE HWO.

BY SUNDAY MORNING, THE COLD FRONT WILL BE SITUATED JUST NW OF THE
FORECAST AREA. FROM THAT POINT THROUGH TUESDAY, MODEL SOLUTIONS
NOTABLY DIVERGE WITH THE PLACEMENT OF THE FRONT. THE GFS/GEM SHOW
THE FRONT PASSING THROUGH SUNDAY INTO MONDAY, WITH RAIN CHANCES
ESSENTIALLY ENDING SUNDAY NIGHT. THE ECMWF SUGGESTS THE FRONT WILL
DAWDLE OVER THE CWA WITH RAIN CHANCES CONTINUING INTO TUESDAY. THERE
IS AT LEAST SOME AGREEMENT DURING THIS TIME FRAME THAT MOST
SHORTWAVE ENERGY WILL REMAIN NORTH OF THE REGION, SUGGESTING PRECIP
WOULD LIKELY BE MORE DIURNALLY DRIVEN AND LESS ORGANIZED. THERE WILL
ALSO BE BROADER-SCALE LIFT BETWEEN THE NORTHERN STREAM OF THE JET
SITUATED ACROSS THE MO/OH VALLEYS AND THE SOUTHERN STREAM NEAR/ALONG
THE COAST. IF THE ECMWF SOLUTION PANS OUT, IT COULD PORTEND A
POTENTIAL FLOOD THREAT ACROSS THE AREA INTO EARLY NEXT WEEK. FOR
NOW, WILL KEEP ISOLATED/SCATTERED POP IN THE FORECAST INTO TUESDAY
GIVEN THE CURRENT LEVEL OF UNCERTAINTY.

TUESDAY INTO THE MIDDLE OF THE WEEK, UPPER TROUGHING IS EXPECTED TO
DEEPEN OVER THE EASTERN CONUS, SHOVING THE FRONT SOUTHWARD AND
CUTTING OFF RAIN CHANCES OVER THE AREA BY WEDNESDAY. /DL/

&&

.PRELIMINARY POINT TEMPS/POPS...
JACKSON       67  87  68  82 /  13  41  23  37
MERIDIAN      65  87  67  83 /  12  40  15  28
VICKSBURG     68  86  70  82 /  14  44  33  49
HATTIESBURG   67  89  68  84 /  13  13  10  24
NATCHEZ       69  87  70  81 /  13  19  26  46
GREENVILLE    65  81  68  81 /  22  68  52  57
GREENWOOD     64  81  68  81 /  13  66  44  47

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&

$$



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.