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000
FXUS64 KTSA 172324
AFDTSA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
624 PM CDT FRI MAY 17 2013

.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FLYING CONDITIONS WILL AGAIN DETERIORATE OVERNIGHT AS LOW
CLOUDS AND FOG DEVELOP. MAY NOT BE AS BAD AS LAST NIGHT AND
EARLY THIS MORNING THOUGH. CONDITIONS WILL IMPROVE BY LATE
SATURDAY MORNING.


&&

.PREV DISCUSSION... /ISSUED 319 PM CDT FRI MAY 17 2013/

DISCUSSION...
WARM FRONTAL ZONE EVIDENT IN SFC DEW POINTS AND MARKED BY SWATH OF
PERSISTENT LOW CLOUDS ESSENTIALLY BISECTING OK FROM SE-NW. LEAD
SHORTWAVE TROUGH MOVING INTO THE SW U.S. WILL CAUSE THE BOUNDARY
TO LIFT NORTH TONIGHT AND SAT MORNING. WITH WARM AIR AND MOISTURE
ADVECTION IN 850-700MB LAYER THE CHANCE OF AN ELEVATED THUNDERSTORM
OR TWO EARLY SAT MORNING ARE NON-ZERO...HOWEVER STRONGER CAP ABOVE
THIS LAYER MAKES CONFIDENCE TOO LOW TO INCLUDE IN THE FORECAST AT
THIS TIME. VERY WARM AND STRONGLY CAPPED WARM SECTOR WILL SPREAD
NORTH OF THE AREA BY SATURDAY AFTERNOON WITH TEMPS WELL INTO THE
80S AND PERHAPS LOWER 90S WEST OF TULSA. DRY LINE WILL BE PRESENT
NEAR OK/TX BORDER SAT AFTERNOON AND WHILE MORE WIDESPREAD
THUNDERSTORM DEVELOPMENT WILL BE TO TH NORTHWEST ASSOCIATED WITH
BETTER SYNOPTIC FORCING...AT LEAST ISOLATED STORMS POSSIBLE
FARTHER SOUTH COULD EVENTUALLY MAKE A RUN TOWARD EASTERN OK SAT
NIGHT.

FOR THE FIRST TIME IN WEEKS...A STRONG CROSS-PACIFIC JET WILL SET
UP AS A NEGATIVELY TILTED UPPER TROUGH MOVES INLAND. THIS SET UP
SHOULD FAVOR AN OUTBREAK OF SEVERE WEATHER IN THE SOUTHERN AND
CENTRAL PLAINS SUNDAY. AGAIN...STRONG CAPPING WILL LIMIT ANY
DEVELOPMENT MOST OF THE DAY...BUT MORE FAVORABLE DYNAMICS WILL BE
PRESENT FARTHER SOUTH WITH DRY LINE PUSHING CLOSER TO I-35
CORRIDOR LATE IN THE DAY. DEEP LAYER SHEAR WILL BE MORE THAN
SUFFICIENT FOR SUPERCELLS AND ALL MODES OF SEVERE POSSIBLE. STORMS
SHOULD BEGIN TO IMPACT EASTERN OK BY EVENING...AND MOST GUIDANCE
SHOWS A SIGNAL OF STORMS GROWING INTO AN MCS SUNDAY NIGHT WHICH
WILL MOVE ACROSS NORTHERN AREAS.

SYNOPTIC BOUNDARY POSITIONS DO NOT CHANGE SIGNIFICANTLY BY MONDAY
AND ANOTHER STRONG UPPER WAVE EXPECTED TO ROTATE AROUND BASE OF
UPPER TROUGH OVER THE CENTRAL PLAINS. COMPLICATING FACTOR OF
COURSE WILL BE WHAT IMPACT SUNDAY NIGHT STORMS HAVE...BUT THERE
SHOULD ALSO BE AN OUTFLOW BOUNDARY SOMEWHERE OVER EASTERN OK.
PARAMETERS AGAIN IN PLACE FOR SEVERE WEATHER WITH LATE AFTERNOON
AND EVENING THE FAVORED TIME. ANOTHER COMPLEX OF STORMS POSSIBLE
MONDAY NIGHT INTO TUESDAY WITH HEAVY RAINFALL POSSIBLY A CONCERN
BY THIS TIME.

SYNOPTIC BOUNDARY SLOW TO MOVE EAST OF THE AREA AND WILL MAINTAIN
HIGH CHANCE OF THUNDERSTORMS FOR TUESDAY. WIND PROFILES STILL
INDICATE SOME SEVERE WEATHER POTENTIAL...HOWEVER INSTABILITY MAY
BE IN QUESTION BY THIS TIME...DEPENDING ON HOW THINGS PLAY OUT
SUNDAY AND MONDAY. FRONT WILL FINALLY CLEAR THE AREA BY WEDNESDAY
BUT RETURN NORTH LATER IN THE WEEK. UPPER RIDGING BUILDS IN BY
THIS TIME AND WOULD EXPECT THUNDERSTORM COVERAGE TO BE ISOLATED AT
BEST.

&&

.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&

$$

AVIATION...10