Special Weather Statement, NWS Jackson, MS

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
1032 AM CDT WED MAY 1 2013

.DISCUSSION...SATELLITE REVEALS A VERY PRONOUNCED UPPER LEVEL LOW
CENTERED OVER CENTRAL LOUISIANA THIS MORNING.  THIS UPPER LOW WILL
CONTINUE TO CHURN AND SLOWLY MEANDER EAST SOUTHEAST ABOUT THE REGION
TODAY.  THIS WILL RESULT IN WIDESPREAD SHOWERS AND SCATTERED
THUNDERSTORMS LIFTING NORTHWEST ACROSS THE FORECAST AREA DURING THE
COURSE OF THE DAY.

WITH PRECIPITABLE H2O VALUES CLIMBING ABOVE 1.50 INCHES...VIA THE
12Z KJAN RAOB...SOME OF THE RAINFALL COULD BE HEAVY TODAY.  ACTIVITY
CURRENTLY OVER MY CWA NORTH OF INTERSTATE 20...HAS ALREADY YIELDED A
SWATH OF 1-2 INCH RAINFALL...WITH SOME LOCALIZED HIGHER AMOUNTS AS
ACTIVITY HAS TRAINED ACROSS THE SAME AREA.  THIS COULD LEAD TO SOME
LOCALIZED FLASH FLOODING AS WELL AS RISES ON SOME AREA RIVERS...
CREEKS...AND STREAMS.

NO REPORTS OF FLASH FLOODING HAVE CURRENTLY BEEN SUBMITTED.
HOWEVER...GIVEN RAINFALL FROM YESTERDAY...COMBINED WITH THE
CURRENT/ONGOING RAINFALL TOTALS FROM THIS MORNING...AND THE OVERALL
SCENARIO THAT'S EXPECTED TO PLAY OUT THROUGH THE COURSE OF THE
DAY...WE'LL GO AHEAD ON THIS UPDATE AND HIGHLIGHT THE POTENTIAL FOR
HEAVY RAIN LEADING TO LOCALIZED FLASH FLOODING IN THE HWO FOR TODAY
INTO TONIGHT.  THIS POTENTIAL WILL EXIST AREAWIDE...BUT CERTAINLY
ALONG AND NORTH OF INTERSTATE 20 WHERE RAINFALL HAS BEEN MORE
PREVALENT OVER AT LEAST THE PAST WEEK AND SOILS ARE A BIT MORE
SATURATED COMPARED TO THE REMAINDER OF THE CWA.

RAIN AND CLOUDS WILL ALSO HELP TO KEEP HIGHS DOWN A BIT TODAY
COMPARED TO RECENT DAYS.  WHILE A FEW BREAKS IN CLOUD COVER ARE
POSSIBLE THIS AFTERNOON...THEY'LL BE FEW AND FAR BETWEEN.  LOOK FOR
HIGHS THIS AFTERNOON TO ONLY WARM INTO THE MIDDLE AND UPPER 70S.

OVERALL ELEMENTS OF THE FORECAST LOOK GOOD FOR TODAY.  OTHER THAN
SOME MINOR ADJUSTMENTS TO THE HOURLY GRIDS AS A RESULT OF CURRENT
TRENDS...AND TO THE HWO ADDING THE MENTION OF LOCALLY HEAVY RAIN FOR
TODAY...NO OTHER CHANGES WILL BE MADE TO THE FORECAST ON THIS
UPDATE. /19/

&&

.AVIATION...MOST TAF SITES ARE VFR THIS MORNING WITH THE EXCEPTION
OF HBG WERE MVFR CEILINGS AROUND 700 FT WERE OCCURRING. SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ARE MOVING ACROSS THE AREA AND
THIS WILL CONTINUE THROUGH TONIGHT AS A SLOW MOVING UPPER LOW TRACKS
ACROSS SOUTHEAST LOUISIANA. EXPECT VFR OCCASIONAL MVFR CONDITIONS AT
ALL TAF SITES TODAY AS SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE
THROUGH THE DAY. SHOWERS ARE EXPECTED TO CONTINUE THROUGH THE NIGHT
INTO EARLY THURSDAY WITH IFR/MVFR CEILINGS AND VISIBILITIES. /17/

&&

.PREV DISCUSSION... /ISSUED 346 AM CDT WED MAY 1 2013/

SHORT TERM...TODAY THROUGH THURSDAY NIGHT...SLOW MOVING UPPER LOW
IS CENTERED OVER SOUTHWEST LOUISIANA THIS MORNING AS MOIST SOUTHEAST
FLOW CONTINUES. SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE ACROSS
MUCH OF THE AREA WITH THE MAIN FOCUS OF THE PRECIP ALONG A
CONVERGENT BOUNDARY THAT EXTENDS FROM NORTHEAST LOUISIANA TO
SOUTHEAST MISSISSIPPI. THE SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE MORNING AND EXPECT THIS CONVERGENT BOUNDARY TO SLOWLY
SHIFT NORTHWARD THROUGH THE MORNING HOURS INTO THE AFTERNOON.

THE UPPER LOW WILL BE CENTERED OVER SOUTHEAST LOUISIANA BY THIS
EVENING AND AS IT DOES THE SURFACE FLOW WILL BECOME MORE EASTERLY
TONIGHT INTO THURSDAY. THE SHOWERS WILL CONTINUE ACROSS MUCH OF THE
AREA OVERNIGHT...BUT HEAVIER PRECIPITATION IS POSSIBLE CLOSER TO THE
UPPER LOW IN THE SOUTH. SHOWERS AND ISOLATED THUNDERSTORMS WILL
CONTINUE TO BE POSSIBLE ACROSS THE AREA ON THURSDAY...ALTHOUGH
EXPECT THE COVERAGE TO BE LESS THAN TODAY. AS THE LOW SHIFTS
SOUTHEAST THE FLOW WILL BECOME MORE EAST-NORTHEAST AND THIS WILL
ALLOW FOR SOME DRIER AIR TO WORK ITS WAY ACROSS THE AREA THURSDAY
EVENING INTO THE OVERNIGHT HOURS...BUT SHOWERS WILL CONTINUE TO BE
POSSIBLE. ANOTHER CUT-OFF LOW WILL DROP INTO THE SOUTHERN PLAINS
WITH AN ASSOCIATED SURFACE LOW/COLD FRONT THAT WILL EXTEND JUST TO
THE WEST OF THE AREA FRIDAY MORNING WITH INCREASING CHANCES OF
SHOWERS ON FRIDAY./15/

LONG TERM...THE SURFACE TROUGH WILL MOVE ACROSS MUCH OF THE AREA
FRIDAY...EXITING ERN ZONES FRIDAY NIGHT. A DEEP UPPER LOW THAT IS
FORECAST TO DROP INTO THE CNTRL/SRN PLAINS WILL PROVIDE SYNOPTIC
UPPER FORCING ACROSS DEEP MOISTURE THAT WILL PERSIST ACROSS THE
AREA. SYNOPTIC FORCING...ALTHOUGH WEAKENING...CONTINUES AS THE UPPER
LOW STALLS OVER ARKANSAS. DEEPER MOISTURE ERODES FROM THE WEST
SATURDAY WITH THE BETTER RAIN CHANCES PAINTED OVER ERN ZONES AS THE
850 MB TROUGH EDGES EWD OUT OF THE AREA. THE GFS AND EURO HAVE
DIFFERED OVER THE PAST FEW RUNS...THE GFS PUSHING THE UPPER LOW MUCH
FARTHER SWD INTO THE MID/LWR MS VALLEY THIS WEEKEND WHILE THE EURO
KEPT THE LOW CENTER FARTHER NWD AND RAPIDLY PIVOTED THE SYSTEM OUT
TO THE NE. THE LATEST EURO RUN IS NOW SPLITTING THE SYSTEM INTO TWO
CENTERS...ONE LIFTING RAPIDLY OUT TO THE N AND THE SECOND DIGGING
INTO MS BY SUNDAY...EVEN FARTHER SWD THAN THE GFS HAS BEEN
ADVERTISING. THE FORECAST WILL FOLLOW THE MORE CONSISTENT GFS RUNS
FOR NOW...TRACKING THE UPPER LOW INTO THE MID SOUTH REGION AND
MOVING IT TO OUR NE FOR MONDAY.

AS THE MODELS COME TO A BETTER CONSENSUS ON THE SWD PROGRESSION OF
THE UPPER LOW THEY ARE ALSO COMING INTO BETTER AGREEMENT THAT A
COOLER AIR MASS WILL BE ON TAP FOR THE ARKLAMISS THIS WEEKEND.
TEMPERATURES WILL REMAIN DIFFICULT TO PIN DOWN IN THE EXTENDED
PERIOD AND WILL DEPEND GREATLY ON THE EVENTUAL EVOLUTION OF THE
UPPER LOW TRACK. MEX MOS GUIDANCE HAS BEEN FOLLOWED FOR THIS
PACKAGE...SWINGING A LITTLE COOLER THAN LAST NIGHTS RUN FOR THE
WEEKEND WITH A WARM UP FOR EARLY NEXT WEEK. /03/

&&

.PRELIMINARY POINT TEMPS/POPS...
JACKSON       77  63  74  61 / 100  66  73  39
MERIDIAN      74  61  73  61 / 100  53  66  38
VICKSBURG     78  65  74  61 / 100  74  77  44
HATTIESBURG   77  64  75  63 / 100  69  61  35
NATCHEZ       79  63  75  58 / 100  74  53  35
GREENVILLE    77  64  74  59 / 100  63  79  51
GREENWOOD     76  62  74  61 / 100  52  70  44

&&

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

19/17

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
118 PM CDT WED MAY 1 2013

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
021830-
ASHLEY-CHICOT-MOREHOUSE-WEST CARROLL-EAST CARROLL-RICHLAND-
MADISON LA-FRANKLIN LA-CATAHOULA-TENSAS-CONCORDIA-BOLIVAR-
SUNFLOWER-LEFLORE-GRENADA-CARROLL-MONTGOMERY-WEBSTER-CLAY-LOWNDES-
CHOCTAW-OKTIBBEHA-WASHINGTON-HUMPHREYS-HOLMES-ATTALA-WINSTON-
NOXUBEE-ISSAQUENA-SHARKEY-YAZOO-MADISON MS-LEAKE-NESHOBA-KEMPER-
WARREN-HINDS-RANKIN-SCOTT-NEWTON-LAUDERDALE-CLAIBORNE-COPIAH-
SIMPSON-SMITH-JASPER-CLARKE-JEFFERSON-ADAMS-FRANKLIN MS-LINCOLN-
LAWRENCE-JEFFERSON DAVIS-COVINGTON-JONES-MARION-LAMAR-FORREST-
118 PM CDT WED MAY 1 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL MISSISSIPPI...
NORTHEAST LOUISIANA...AND EXTREME SOUTHEAST ARKANSAS.

.DAY ONE...TONIGHT AND THURSDAY

A SLOW MOVING AREA OF LOW PRESSURE WILL MOVE ACROSS SOUTHEAST
LOUISIANA TO THE MISSISSIPPI GULF COAST BY EARLY THURSDAY.
PERIODS OF SHOWERS AND ISOLATED THUNDERSTORMS WILL MOVE ACROSS
THE REGION THIS AFTERNOON INTO TONIGHT. AREA RADARS HAVE SHOWED THAT RAINFALL
AMOUNTS OF AROUND A HALF INCH TO LOCALLY TWO TO FOUR INCHES HAVE FALLEN
OVER THE ARKLAMISS AS OF THIS AFTERNOON. EXPECT LOCALLY HEAVY RAINFALL
THROUGH TONIGHT AS AN ADDITIONAL TWO TO LOCALLY THREE INCHES CAN BE
EXPECTED. THIS MAY PRODUCE SOME ISOLATED FLASH FLOODING ISSUES AS
WELL AS SOME LIMITED RISES IN SMALL CREEKS...STREAMS AND LOW LYING
AREAS IN WATER LEVELS.

.DAYS TWO THROUGH SEVEN...THURSDAY NIGHT THROUGH TUESDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER CALL TO ACTION STATEMENT...
THE ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS...AND
EMERGENCY MANAGEMENT PERSONNEL IN SUPPORT OF SEVERE WEATHER
OPERATIONS WILL NOT BE NEEDED THROUGH TUESDAY.

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE AT
WWW.SRH.NOAA.GOV/JAN.

17

MSZ063-064-072-073-011930-
MARION MS-LAWRENCE MS-LAMAR MS-JEFFERSON DAVIS MS-
159 PM CDT WED MAY 1 2013

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSON MS
159 PM CDT WED MAY 1 2013

...STRONG THUNDERSTORM OVER EASTERN MARION COUNTY...
A STRONG THUNDERSTORM CAPABLE OF PRODUCING PEA TO DIME SIZE HAIL AND
40 TO 50 MPH WINDS WAS LOCATED 5 MILES NORTHWEST OF PINEBUR AT 159 PM
CDT...MOVING NORTHWEST AT 15 MPH.

PEOPLE IN SOUTHWESTERN JEFFERSON DAVIS...WEST CENTRAL LAMAR...EXTREME
SOUTHEASTERN LAWRENCE AND MARION COUNTIES SHOULD MONITOR THIS STORM
CLOSELY.

LAT...LON 3136 9004 3149 8979 3117 8961 3108 8979
TIME...MOT...LOC 1859Z 148DEG 11KT 3120 8975

MSZ061-012040-
FRANKLIN MS-
311 PM CDT WED MAY 1 2013

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSON MS
311 PM CDT WED MAY 1 2013

A STRONG THUNDERSTORM CAPABLE OF PRODUCING PENNY TO NICKEL SIZE HAIL
AND 40 TO 50 MPH WINDS WAS LOCATED 3 MILES EAST OF KIRBY AT 311 PM
CDT...MOVING NORTH AT 15 MPH.

VERY HEAVY RAIN IS ALSO POSSIBLE WITH THIS STORM.

PEOPLE IN WESTERN FRANKLIN COUNTY SHOULD MONITOR THIS STORM CLOSELY.

LAT...LON 3140 9099 3161 9110 3161 9086 3146 9080
TIME...MOT...LOC 2011Z 159DEG 11KT 3152 9093

BK