National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS64 KOHX 181820
AFDOHX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
120 PM CDT TUE JUN 18 2013

.MESOSCALE UPDATE...
SCATTERED SHOWER ACTIVITY PULLING OFF SOUTH END OF PLATEAU AND
EXPECT THIS TREND TO CONTINUE. A MIX OF CLOUDS AND SUN EVIDENT IN
LATEST VISIBLE LOOP OVER THE NORTHWEST HALF OF THE MID STATE.

HAVE TRIM AFTERNOON HIGHS BACK A TAD BUT WHERE SUN GETS OUT
SHOULD GET INTO THE LOWER 80S.

THERE IS ANOTHER FRONT TO OUR NORTH ACROSS ILLINOIS AND INDIANA
THAT WILL BE DROPPING SOUTHWARD THIS EVENING. WILL PROBABLY RUN
ISOLATED THUNDER THROUGH THE EVENING HOURS BUT NOT EXPECTING MUCH
FROM THIS FRONT AS IT IS UNDERGOING FRONTOLYSIS BY THE TIME IT GETS
DOWN THIS WAY.

BOYD

&&

.PREV DISCUSSION... /ISSUED 102 PM CDT TUE JUN 18 2013/

UPDATE...FOR 18Z AVIATION DISCUSSION.

AVIATION...18Z AVIATION DISCUSSION.
UNCERTAINTIES...MVFR CEILING EROSIONS PROGRESSION TIMING AND CSV/FOG
POTENTIAL 19/06Z-19/14Z. OVERALL ATM DRYING TREND TO CONTINUE THRU 19/00Z...
ERROSION CEILING TIMING 19/22Z CSV EXPECTED. NWLY UPPER LEVEL FLOW WILL
POSSIBLY BRING A WEAK DISTURBANCE ACROSS TAF SITES 19/06Z-19/14Z...SO
DO EXPECT PER CALM WINDS/LOW LEVEL MOISTURE POOLING THE POTENTIAL FOR
MVFR FOG...POSSIBLE IFR FOG CSV. HOWEVER...NOT A MAX RADITIONAL POTENTIAL
EVENT SO WILL NOT GO LIFR/VLIFR...BUT COULD BE LOCALLY POSSIBLE THOUGH WITH
BREAKS. EXPECT DRIER NWLY UPPER LEVEL FLOW ALONG WITH BUILDING SFC RIDGING
INFLUENCES TO PROVIDE FOR VFR CONDITIONS BY 19/14Z-19/15Z...WITH WEAK SFC
FRONTAL BOUNDARY MOVING IN FROM N AIDING IN CU DEVELOPMENT BY 19/16Z.

PREV DISCUSSION.../ISSUED 1019 AM CDT TUE JUN 18 2013/

UPDATE...
HAVE UPDATED THE GRIDS/ZONES TO BETTER REFLECT CURRENT RADAR AND
SATELLITE TRENDS THROUGH THE MORNING. 850 MBAR WINDS HAVE TURNED
NORTHERLY OVER THE WEST HALF OF TENNESSEE WITH DRIER AIR WORKING
INTO THE MID STATE DURING THE DAY. SHOULD SEE CLOUDS DECREASE FROM
THE NORTHWEST DURING THE DAY. LATEST NAM KEEPS SHOWERS AND
ISOLATED THUNDER OVER SOUTHEAST MID STATE THIS AFTERNOON BUT DRY
OVER A GOOD PART OF THE MID STATE. THERE IS CURRENTLY A COOL FRONT
TO OUR NORTH ACROSS THE MID WEST FROM WESTERN ILLINOIS EASTWARD
ACROSS CENTRAL INDIANA INTO CENTRAL OHIO. THIS FRONT WILL DROP
SOUTHWARD DURING THE AFTERNOON AND BE ALONG THE OHIO RIVER BY LATE
AFTERNOON. THE FRONT WILL CONTINUE SOUTH BOUND TONIGHT BUT APPEARS
TO UNDERGO FRONTOLYSIS AT IT GETS DOWN INTO MY CWA. WILL TAKE A
CLOSER LOOK AT TONIGHTS FORECAST A LITTLE LATER.

BOYD

PREV DISCUSSION... /ISSUED 646 AM CDT TUE JUN 18 2013/

UPDATE...FOR 12Z AVIATION.

AVIATION...12Z TAF DISCUSSION.

STILL SOME LIGHT RAIN AROUND MIDDLE TENNESSEE AT ISSUANCE ON THE
BACKSIDE OF THIS MORNING`S MCV THAT PUSHED THROUGH THE STATE. IFR
TO MVFR CIGS AND VIS WILL PERSIST THROUGH 14-15Z AT ALL SITES
BEFORE FLIGHT CATEGORIES BEGIN TO IMPROVE BEHIND THIS SYSTEM.
TYPICAL TRAILING STRATUS DECK IS LACKING...SO SKIES CAN BE
EXPECTED TO GO SKC AT ALL SITES BY 18Z. WINDS WILL BE LIGHT OUT OF
THE NORTH. WITH THE FRONTAL BOUNDARY LINGERING...CLEAR SKIES AND
SATURATED GROUNDS...OVERNIGHT FOG DEVELOPMENT IS POSSIBLE AT ALL
TERMINALS TUESDAY NIGHT...WITH SOME IFR POSSIBLE AT KCSV AS EARLY
AS 05Z/19 JUN.

27/UNGER

PREV DISCUSSION... /ISSUED 525 AM CDT TUE JUN 18 2013/

UPDATE...

HAVE GONE AHEAD AND CANCELED THE FFA WHICH WAS IN EFFECT FOR OUR
SOUTHERN COUNTIES. WIDESPREAD HEAVY RAIN HAS ENDED AND LATEST
SHORT RANGE GUIDANCE SUGGESTS JUST SCT ACTIVITY FOR THE REST OF
THE DAY.  REST OF FORECAST IS UNCHANGED.

PREV DISCUSSION... /ISSUED 327 AM CDT TUE JUN 18 2013/

DISCUSSION...

FAIRLY WELL DEFINED UPPER SYS MOVING ACRS WESTERN PORTION OF THE
CWFA THIS MORNING WITH WIDESPREAD RAIN. WARM RAIN PROCESS ONGOING
WITH IMPRESSIVE RAINFALL RATES IN SOME OF THE HEAVIER BANDS -
RANGING AROUND 0.5 IN/HR AT MANY SPOTS TO A MAX OF 1.3 INCH IN ONE
HOUR EARLIER AT MCEWEN. FORTUNATELY HVY RAINS HAVE NOT PERSISTED
OVER ANY ONE SPOT KEEPING OUR FLOOD RISK LOW. WILL HOLD ONTO THE
FFA FOR NOW FOR THE AREAS WHICH SAW THE HEAVIEST RAINS YDAY BUT
WILL CONSIDER CANCELING BASED ON TRENDS THRU SHIFT CHANGE.
OTHERWISE POPS ARE TRICKY TODAY AS CVRG WILL LIKELY DIMINISH
QUICKLY FROM NW TO SE AS UPPER LOW SHEARS EAST BUT SOME
REDEVELOPMENT STILL PSBL. WILL HANDLE WITH AN ERLY CATEGORICAL
PERIOD TAPERING FROM THE NW AS THE DAY GOES ON. MAV TEMPS LOOK
RSNBL AS WE SHOULD BE ABLE TO WARM UP AS PRECIP CVRG DECREASES AND
SOME SUNSHINE DVLPS.

EXPECT LINGERING PCPN OVER OUR SE TO END TNGT THEN WITH A VERY
MOIST ATMOS/LIGHT WINDS XPCT TO SEE SOME PATCHY FOG. AGAIN THE MAV
TEMPERATURES LOOK RSNBL.

NO SIGNIFICANT CHGS MADE TO THE EXTENDED AS WE ENTER WHAT LOOKS
LIKE A PRETTY TYPICAL SUMMERTIME REGIME. ATMOSPHERE LOOKS TO
MOISTEN ENUF BY THE END OF THE WEEK FOR SOME DIURNAL CONVECTION
AND THIS WILL CONTINUE INTO NEXT WEEKEND. LEANED TWRD THE WARMER
MEX TEMPS VS THE COOLER HPC VALUES.

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

01