810
FXUS64 KMRX 071741
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
141 PM EDT SUN AUG 7 2022
UPDATE
FOR 18Z AVIATION.
SHORT TERM (TODAY AND TONIGHT)
KEY MESSAGES:
1. SCATTERED TO NUMEROUS SHOWERS AND STORMS ARE EXPECTED, ESPECIALLY
IN THE AFTERNOON AND EARLY EVENING HOURS.
2. LOCALIZED FLOODING REMAINS OF CONCERN DUE TO SATURATED SOILS
AND POTENTIAL FOR HEAVY DOWNPOURS. ISOLATED DAMAGING WINDS ARE
ALSO POSSIBLE WITHIN THE STRONGEST STORMS.
TODAY
CURRENTLY, EARLY THIS MORNING, AN UPPER LOW IS LOCATED OVER WEST
TENNESSEE WITH A SURFACE FRONTAL BOUNDARY IN THE UPPER MIDWEST. THE
BERMUDA HIGH ALSO CONTINUES TO BE NOTABLY STRONG, KEEPING THE REGION
IN A SOUTHWESTERLY LOW-LEVEL FLOW PATTERN. HEADING INTO THE DAYTIME,
THE UPPER LOW IS FORECAST TO MOVE WESTWARD WITH EMBEDDED UPPER-LEVEL
SHORTWAVE ENERGY BEING THE MAIN LARGER SCALE FEATURE OF INTEREST. AS
SUCH, DIURNAL HEATING AND CONTINUED ABOVE NORMAL MOISTURE WILL ALL
BE SUFFICIENT FOR SCATTERED TO NUMEROUS CONVECTION, INITIALLY
FORMING OVER THE HIGHER TERRAIN. IN COMPARISON TO YESTERDAY, THE
CONVECTIVE ENVIRONMENT LOOKS AT LEAST SLIGHTLY LESS FAVORABLE
OVERALL. MID-LEVEL LAPSE RATES LOOK TO BE CLOSER TO 5.5 C/KM, RATHER
THAN 6 C/KM WITH MLCAPE STILL FORECAST TO REACH AT OR ABOVE 2,000
J/KG IN SOME PLACES. NEVERTHELESS, LOCALIZED DCAPE VALUES OF NEAR
800 J/KG POINT TOWARDS THE CONTINUED POTENTIAL FOR AT LEAST A FEW
STRONGER STORMS. REGARDING THE FLOODING CONCERNS, SOIL CONDITIONS IN
THE NORTHEASTERN HALF OF THE REGION ARE SLIGHTLY MORE SATURATED
EARLY THIS MORNING THAN YESTERDAY MORNING. HOWEVER, THE CURRENT
HREF/CAM RUN SHOWS AT LEAST SLIGHTLY LESSENED COVERAGE OF CONVECTION
THAN WHAT WAS SHOWN IN THE PREVIOUS 00Z RUN. WITH ALL OF THESE
FACTORS IN MIND, LOCALIZED FLOODING WILL STILL CONTINUE TO BE
MESSAGED, BUT THE COVERAGE CURRENTLY DOES NOT LOOK WIDESPREAD ENOUGH
FOR THE ISSUANCE OF A FLOOD WATCH. THIS COULD CERTAINLY CHANGE WITH
A LATER UPDATE, BUT CONFIDENCE IS TOO LOW FOR ISSUANCE OF ONE ACROSS
ALL OF THE AREAS WHERE THE GROUND IS SATURATED ENOUGH FOR CONCERN,
IF GIVEN ENOUGH COVERAGE.
TONIGHT
BY TONIGHT, THE GENERAL LOSS OF INSTABILITY WILL LEAD TO DIMINISHING
COVERAGE IN THE HOURS AFTER SUNSET. SOME CAMS ARE SHOWING POTENTIAL
RE-DEVELOPMENT OF ISOLATED CONVECTION IN THE OVERNIGHT HOURS, BUT
ANY IMPACTS WOULD LIKELY BE MINIMAL. IN ANY CASE, THESE INDICATIONS
WERE INCORPORATED IN POPS. FOG DEVELOPMENT IS ALSO LIKELY IN SEVERAL
PLACES AGAIN DUE TO THE ASSUMPTION OF RECENT RAINFALL.
BW
LONG TERM (MONDAY THROUGH SATURDAY)
KEY MESSAGES:
1. THREAT FOR STRONG STORMS AND LOCALIZED FLOODING CONTINUES INTO
WEDNESDAY AND POSSIBLY THURSDAY.
2. COLD FRONT EXPECTED TO PUSH THROUGH THE AREA AROUND THURSDAY,
WITH DRIER CONDITIONS FRIDAY AND SATURDAY.
DISCUSSION:
AT THE BEGINNING OF THIS PERIOD ON MONDAY MORNING, A MASSIVE UPPER
RIDGING IS DOMINATING THE SOUTHERN 2/3 OF THE CONUS, WITH A WEAK
NORTH-TO-SOUTH UPPER TROUGH LOOSELY PARALLELING THE MISSISSIPPI
RIVER. AT THE SURFACE, THERE IS A SURFACE LOW CENTERED NEAR LAKE
MICHIGAN, WITH A WEAK COLD FRONT EXTENDING TO THE SOUTHWESTWARD
ACROSS THE PLAINS, INTO THE TEXAS PANHANDLE. A MOIST SOUTHERLY FLOW
CONTINUES INTO OUR REGION WITH DEWPOINTS IN THE LOWER 70S UP AND
DOWN THE VALLEY IN THE CWA.
DURING THE FIRST HALF OF THE WEEK, OUR AREA STAYS KIND OF STATUS QUO
WITH DIURNAL CONVECTION IN THIS SAME AIRMASS, AS THE SURFACE LOW
MOVES EAST AND THE COLD FRONT SLIDES SLOWLY SOUTHEASTWARD TOWARD US.
BY WEDNESDAY OR THURSDAY THE FRONT SHOULD HAVE SAGGED INTO THE AREA,
GIVING MORE OF A FOCUS FOR CONVECTION.
LATER IN THE PERIOD, EVENTUALLY THE FRONT IS EXPECTED TO MOVE ON
THROUGH, WITH SLIGHTLY COOLER, DRIER AIR FILTERING INTO THE REGION
FOR FRIDAY AND SATURDAY, AS WELL AS THE RAIN CHANCES LOOKING TO SHUT
DOWN TEMPORARILY.
FOR SEVERE AND FLOODING THREAT, LOOKING LIKE A SLIGHTLY LESS TREND
MONDAY AND TUESDAY, THEN CLIMBING AGAIN TOWARD WEDNESDAY AS THE
FRONT GETS CLOSER. THE SEVERE/FLOODING THREAT IS EXPECTED TO
TEMPORARILY END NORTH TO SOUTH AS THE DRIER AIRMASS MOVES INTO THE
REGION BEHIND THE COLD FRONT.
GM
AVIATION
18Z TAF DISCUSSION.
ANOTHER DAY OF DIURNAL CONVECTION ORIGINATING OVER THE HIGHER
TERRAIN AND THEN PROPAGATING INTO THE VALLEY. MOSTLY VFR
CONDITIONS EXCEPT IN STORMS, AND THEN POTENTIAL FOR MVFR/IFR
CONDITIONS AROUND 08/1200Z AT TRI AND TYS.
GC
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page