NWS Discussion

000
FXUS64 KOHX 180152
AFDOHX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
852 PM CDT THU MAY 17 2012

.UPDATE...

ISOLATED SHOWERS AND THUNDERSTORMS HAVE MOSTLY DISSIPATED ACROSS
THE CWA BUT SOME RENEWED DEVELOPMENT CONTINUES ACROSS WESTERN AND
SOUTHERN MIDDLE TENNESSEE. WILL LEAVE IN A SLIGHT CHANCE POP
THROUGH 06Z FOR THESE AREAS. ALSO ADDED MENTION OF PATCHY FOG ON
THE PLATEAU AFTER 06Z AS LOW TEMP/DEWPOINT SPREADS AND CLEARING
SKIES SHOULD ALLOW FOR FOG FORMATION LATER TONIGHT. REST OF
FORECAST IS UNCHANGED.


&&

.PREV DISCUSSION... /ISSUED 718 PM CDT THU MAY 17 2012/

UPDATE...AVIATION.

AVIATION...00Z TAFS.
ISO RW-/TRW- SOUTH OF TERMINALS SOON TO DISSIPATE. THERE WAS A
WEAKNESS ALOFT THAT HELPED GENERATE THE ACTIVITY THIS AFTN. VFR
CONDITIONS EXPECTED TNGT...WITH MVFR VIS FM FOG KCSV 09-14Z. H5
RIDGE REBUILDS OVR THE OHVLY FRI...WITH SCT STRATO-CU IN THE AFTN.
RIDGE LOOKS TO SUPPRESS PCPN CHANCES AND WL NOT INCLUDE PCPN IN
THE TAFS FOR NOW.

PREV DISCUSSION... /ISSUED 339 PM CDT THU MAY 17 2012/

DISCUSSION...
ISOLATED SHOWERS AND TSTMS OCCURRING ACROSS THE MID STATE THIS
AFTERNOON. THE ACTIVITY IS MOVING SLOWLY TO THE SOUTHWEST...ALONG
THE MEAN 700-500 FLOW. E-W SHORTWAVE EXTENDS NW FROM AN UPPER LOW
OVER GA. AIRMASS AS A WHOLE IS ON THE DRY SIDE. THUS...THE ACTIVITY
SHOULD DIE OFF THIS EVENING.

UPPER LEVEL AXIS SHOULD SHIFT A LITTLE FURTHER SOUTH ON FRIDAY AND
SATURDAY. ADDITIONALLY MRH VALUES WILL BE SLIGHTLY LESS. EXCEPT
FOR THE PLATEAU AREA...COVERAGE OF AFT TSTMS OVER THE NEXT 2 AFTERNOONS
APPEARS TO BE CLOSER TO 10 PERCENT...AS OPPOSED TO 20 PERCENT
COVERAGE. THUS...WILL OPT TO LEAVE TSTMS OUT OF THE FCST FOR FRI
AND SAT. HOWEVER...I WILL LIKELY INCLUDE ISOLATED EVENING
THUNDERSTORMS FOR THIS EVENING...DEPENDING ON THE LATEST RADAR
TRENDS.

OTW...HEIGHTS TO REMAIN ELEVATED WITH 850 MB TEMPS IN THE 14C-16C
RANGE. THIS EQUATES TO ABOVE NORMAL TEMPS WITH MAX DAILY VALUES WELL
INTO THE 80S. WILL GO ABOVE THE MAV GUIDANCE FOR THE SHORT TERM.

IN THE EXT FCST...NW FLOW AND AN UPPER LEVEL SHORTWAVE TO SET UP FOR
MON AND TUE. WITH THE EURO MATCHING UP FAIRLY WELL WITH THE
GFS...WILL OPT TO GO WITH 40 POPS FOR MON AND MON NT...20-30 ON
TUESDAY. QPF AMOUNTS LOOKING UNIMPRESSIVE WITH .25-.50 STORM TOTAL.
UPPER RIDGING TO BUILD IN FOR WED AND THU.

FOR THE LONG TERM TEMPS...ABOVE NORMAL VALUES TO CONTINUE. WILL OPT
TO GO ABOVE THE MEX GUIDANCE GIVEN THE 18Z GRAPHICAL TEMP PROGS.

&&

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

$$

SHAMBURGER

NWS OHX Office Area Forecast Discussion