Area Forecast Discussion
Issued by NWS Memphis, TN

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FXUS64 KMEG 011458
AFDMEG

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
958 AM CDT WED JUL 1 2015

.UPDATE...

AS OF 945 AM ACROSS THE REGION...A COMPLEX OF SHOWERS AND
THUNDERSTORMS CONTINUES TO MOVE INTO THE REGION FROM THE NORTHWEST.
MODELS DEPICT THE COMPLEX MAINTAINING THROUGH THE AFTERNOON...ESPECIALLY
IN THOSE AREAS OF WEST TN NEAREST THE TN RIVER...AND THUS HAVE
INCREASED POPS FOR THE REST OF THE MORNING AND AFTERNOON
PRIMARILY ACROSS NORTHEAST PORTIONS OF THE CWA. CLOUD COVER WILL
BE A HINDRANCE TO DECENT DAYTIME HEATING TODAY ACROSS MUCH OF WEST
TN AND EAST AR...WITH THE CURRENT TEMPERATURE FORECAST BEING ON
TRACK WITH THE WARMEST TEMPERATURES ACROSS THE DELTA WHERE THE
LOWEST CLOUD COVER WILL RESIDE. OTHER THAN THE SLIGHT ADJUSTMENT
TO POPS THE FORECAST IS ON TRACK...WITH THE POSSIBILITY OF A FEW
STRONG TO SEVERE STORMS THIS AFTERNOON AND EVENING.


ZDM

&&

.PREV DISCUSSION... /ISSUED 459 AM CDT WED JUL 1 2015/

DISCUSSION...SURFACE ANALYSIS EARLY THIS MORNING PLACES A QUASI-
STATIONARY BOUNDARY ALONG I-70 IN MISSOURI. WATER VAPOR
SATELLITE/REGIONAL WSR-88D VAD WIND PROFILES INDICATE A MESOSCALE
CONVECTIVE SYSTEM /MCS/ HAS DEVELOPED IN THE PAST 2-3 HOURS ACROSS
WEST CENTRAL MISSOURI NEAR KANSAS CITY AND BEING FED BY A 35 KT
850 MB LOW LEVEL JET. MEANWHILE...AS OF 4 AM CDT THE MID SOUTH IS
RAIN FREE WITH TEMPERATURES RANGING FROM THE LOWER TO MIDDLE 70S
WITH THE WARMEST READINGS OCCURRING MAINLY ALONG AND WEST OF THE
MISSISSIPPI RIVER. SEVERE THUNDERSTORM POTENTIAL TODAY AND AGAIN
ON THURSDAY...AND THE POTENTIAL FOR HEAVY RAINFALL INTO THE FOURTH
OF JULY WEEKEND ARE THE PREDOMINANT CONCERNS IN THIS MORNING/S
FORECAST.

SHORT TERM MODELS INDICATE THE MESOSCALE CONVECTIVE SYSTEM /MCS/
NORTH OF I-44 IN MISSOURI WILL CONTINUE TO PROPAGATE SOUTH/SOUTH
SOUTHEAST TO THE LOWER MISSISSIPPI VALLEY THIS MORNING...PERHAPS
REACHING PORTIONS OF NORTHEAST ARKANSAS AND THE MISSOURI BOOTHEEL
THIS MORNING AFTER DAYBREAK. THIS MCS MAY WEAKEN AS IT COMES INTO
THE MID SOUTH. HOWEVER...A COMBINATION OF OUTFLOW BOUNDARIES FROM
THIS OVERNIGHT SYSTEM COMBINED WITH SURFACE BASED CAPE VALUES
RISING TO 3000-4000 J/KG...0-6 KM BULK SHEAR BETWEEN 35-40
KTS...FAVORABLE UPPER LEVEL WINDS ALOFT SUGGEST A POTENTIAL FOR
SEVERE THUNDERSTORMS ACROSS THE MID SOUTH TODAY. DAMAGING WINDS
WILL BE THE PREDOMINANT SEVERE WEATHER THREAT WITH A SECONDARY
THREAT OF LARGE HAIL. LOCALIZED FLASH FLOODING FROM HEAVY RAINFALL
WILL ALSO BE POSSIBLE AS PRECIPITABLE WATER VALUES WILL INCREASE
TO AROUND 2 INCHES. HIGH TEMPERATURES TODAY WILL RANGE FROM THE
LOWER 80S NEAR THE TENNESSEE RIVER AND MIDDLE TO UPPER 80S
ELSEWHERE.

AT THIS TIME...FEEL THERE MAY BE A DECREASE IN CONVECTIVE ACTIVITY
THIS EVENING AS THE ATMOSPHERE MAY BE A BIT WORKED OVER INITIALLY.
HOWEVER...MODELS SUGGEST A 40 KT 850 MB LOW LEVEL JET WILL DEVELOP
OVER PORTIONS OF SOUTHERN MISSOURI/ARKANSAS LATE TONIGHT WITH THE
POTENTIAL FOR ANOTHER MCS TO DEVELOP AND SPREAD INTO THE MID SOUTH
ON THURSDAY. FAVORABLE WINDS ALOFT COMBINED WITH 0-6 KM BULK SHEAR
BETWEEN 35-40 KTS...MODERATELY STEEP 700-500 MB LAYER MID LEVEL
LAPSE RATES AROUND 6.5 C/KM AND MODERATE INSTABILITY SUGGEST A
POTENTIAL FOR SEVERE THUNDERSTORMS ACROSS MUCH OF THE MID SOUTH
AGAIN ON THURSDAY. PRECIPITABLE WATER VALUES AROUND 2 INCHES WILL
POSE A POTENTIAL FOR HEAVY RAINFALL ACROSS PORTIONS OF THE MID
SOUTH.

LONG TERM MODEL TRENDS INDICATE AN UPPER LEVEL TROUGH WILL REMAIN
ACROSS THE EASTERN UNITED STATES FRIDAY THROUGH THE FOURTH OF
JULY WEEKEND. CONSEQUENTLY...SEVERAL SHORTWAVES EMBEDDED WITHIN
NORTHWEST FLOW ALOFT ARE EXPECTED TO MOVE THROUGH THE REGION
PRODUCING A POTENTIAL FOR SHOWERS AND THUNDERSTORMS EACH DAY.
STRONG TO SEVERE THUNDERSTORM POTENTIAL ALONG WITH HEAVY RAINFALL
MAY BE POSSIBLE AT TIMES DURING THIS PERIOD.

AT THIS TIME...HAVE DECIDED TO HOLD OFF ON ISSUING A FLASH FLOOD
WATCH FOR PORTIONS OF THE MID SOUTH THURSDAY/THURSDAY NIGHT WITH
THIS FORECAST ISSUANCE DUE TO SOME LINGERING TIMING/COVERAGE
CONCERNS. THIS MAY NEED TO BE CONSIDERED IN SUBSEQUENT FORECASTS
ESPECIALLY WITH THE POTENTIAL FOR HEAVY RAINFALL TO POSE A THREAT
INTO THE UPCOMING HOLIDAY WEEKEND. STAY TUNED...

CJC

&&

.AVIATON...
12Z TAFS

A GRADUALLY TSRA COMPLEX OVER SOUTHERN MO WAS MOVING SE AT
1145Z. A MESOSCALE CIRCULATION /MCV/ FROM THIS FEATURE WILL
LIKELY DROP INTO NORTHEAST AR/WEST TN LATER THIS MORNING...HELPING
TO INITIATE ADDITIONAL TSRA TOWARD MIDDAY. HRRR TAKES THIS
ACTIVITY SOUTH INTO MS DURING THE MID/LATE AFTERNOON...WHICH
APPEARS REASONABLE GIVEN CURRENT MOVEMENT OF THE MCV ON KSGF
RADAR.

TIMING OF NORTHWEST FLOW TSRA COMPLEXES CAN BE CHALLENGING. WITH
THAT SAID...06Z NAM SUGGEST ANOTHER TSRA COMPLEX MAY MAKE IT INTO
THE MIDSOUTH PRIOR TO SUNRISE THURSDAY...AFFECTING JBR AND POSSIBLY
THE OUTBOUND MEM CARGO PUSH.

PWB

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&

$$


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