Heat in Arkansas, August 13, 2010

AREA FORECAST DISCUSSION...CORRECTED TYPO
NATIONAL WEATHER SERVICE TULSA OK
620 AM CDT FRI AUG 13 2010

.DISCUSSION...

SEE THE 12Z AVIATION DISCUSSION BELOW.

&&

.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KMLC/KXNA/KFYV/KFSM.
VFR CONDITIONS WILL PREVAIL FOR THE NEXT 24 HOURS AT ALL TAF
SITES OUTSIDE OF TSRA ACTIVITY. ISOLD TO WDLY SCT TSRA CHANCES
ARE BETTER FOR THE ARKANSAS TAFS...SO I CONTINUED THE CB REMARK IN
THEIR TAFS FROM THE PREVIOUS FORECAST. SRLY SFC WNDS WILL PREVAIL AT
AROUND 10KTS OR LESS...WITH SOME HIGHER GUSTS AT KTUL AFT 18Z.

LACY

&&

.PREV DISCUSSION... /ISSUED 327 AM CDT FRI AUG 13 2010/

DISCUSSION...
A RIDGE OF HIGH PRESSURE REMAINS FIRMLY ENTRENCHED ACROSS THE
SOUTHERN PLAINS. AS SUCH... THE CURRENT HEAT WAVE WILL CONTINUE
THROUGH SATURDAY. HAVE HIGH CONFIDENCE IN MOSTLY A PERSISTENCE
FORECAST THROUGH THAT TIME. THIS WILL PRODUCE AFTERNOON HEAT INDEX
VALUES OVER 110 ACROSS A WIDE AREA... WHICH REMAINS IN AN EXCESSIVE
HEAT WARNING. ISOLATED AFTERNOON THUNDERSTORMS HAVE DEVELOPED ACROSS
FAR SOUTHEAST OKLAHOMA AND WESTERN ARKANSAS THE PAST COUPLE OF
DAYS... AND THIS OCCURRENCE IS EXPECTED THE NEXT COUPLE OF
AFTERNOONS AS WELL.

AS PREVIOUSLY ADVERTISED... CHANGES ARE ON THE WAY. MODELS ARE IN
GOOD AGREEMENT WITH AN UPPER TROUGH TRAVERSING THE CENTRAL PLAINS
OVER THE WEEKEND... WEAKENING THE HIGH PRESSURE RIDGE. A COLD FRONT
IS EXPECTED TO ENTER THE AREA EARLY SUNDAY MORNING... INCREASING
THUNDERSTORM CHANCES. HAVE ADDED POPS IN THE NORTHEAST ON SATURDAY
AS WELL... SINCE FRONTAL CONVECTION TO THE NORTH MAY PRODUCE OUTFLOW
BOUNDARIES THAT COULD INITIATE CONVECTION SOUTH OF THE FRONT.

SUNDAY WILL BE COOLER FOR THE NORTHEAST HALF OF THE AREA... WITH
THE ENTIRE REGION EXPERIENCING A COOL DOWN AFTER THAT.
TEMPERATURES THROUGH THE WORK WEEK ARE EXPECTED TO BE MUCH CLOSER
TO SEASONAL NORMALS THAN THEY HAVE BEEN RECENTLY.

MODELS AGREE ON AN AREA OF UPPER LOW PRESSURE FORMING IN THE
NORTHEASTERN GULF OF MEXICO BY SUNDAY. THIS WILL SERVE TO PUSH THE
PERSISTENT UPPER HIGH TO OUR WEST... ALLOWING NORTHWEST FLOW ALOFT
ACROSS THE AREA DURING THE FIRST PART OF NEXT WEEK. THIS SCENARIO
WOULD BE CONDUCIVE FOR NOCTURNAL MCS ACTIVITY AFFECTING PORTIONS OF
THE REGION DURING THE UPCOMING WEEK. THIS HAS BEEN REFLECTED IN THE
POPS FOR MONDAY INTO WEDNESDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
TUL  103  80 103  78 /  10  10  10  30
FSM  104  78 103  79 /  20  10  20  20
MLC  104  77 104  78 /   0  10   0  10
BVO  104  72 104  73 /  10  10  10  40
FYV   99  73  99  72 /  20  10  20  30
BYV  101  73 100  73 /  20  10  30  40
MKO  103  74 103  74 /  10  10  10  20
MIO  102  76 102  76 /  10  10  30  40
F10  103  76 103  76 /   0  10   0  20
HHW  104  77 105  77 /   0  10  20  10

&&

.TSA WATCHES/WARNINGS/ADVISORIES...
OK...EXCESSIVE HEAT WARNING UNTIL 11 PM SATURDAY FOR OKZ054-OKZ055-
     OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-OKZ061-OKZ062-OKZ064-
     OKZ065-OKZ066-OKZ067-OKZ070-OKZ071-OKZ072-OKZ073-OKZ074-
     OKZ075-OKZ076.

     HEAT ADVISORY UNTIL 11 PM SATURDAY FOR OKZ049-OKZ053-OKZ063-
     OKZ068-OKZ069.

AR...HEAT ADVISORY UNTIL 11 PM SATURDAY FOR ARZ001-ARZ002-ARZ010-
     ARZ011.

     EXCESSIVE HEAT WARNING UNTIL 11 PM SATURDAY FOR ARZ019-ARZ020-
     ARZ029.

&&

AVIATION...30

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
503 AM CDT FRI AUG 13 2010

ARZ001-002-010-011-019-020-029-OKZ049-053>076-132215-
ADAIR OK-BENTON AR-CARROLL AR-CHEROKEE OK-CHOCTAW OK-CRAIG OK-
CRAWFORD AR-CREEK OK-DELAWARE OK-FRANKLIN AR-HASKELL OK-LATIMER OK-
LE FLORE OK-MADISON AR-MAYES OK-MCINTOSH OK-MUSKOGEE OK-NOWATA OK-
OKFUSKEE OK-OKMULGEE OK-OSAGE OK-OTTAWA OK-PAWNEE OK-PITTSBURG OK-
PUSHMATAHA OK-ROGERS OK-SEBASTIAN AR-SEQUOYAH OK-TULSA OK-WAGONER OK-
WASHINGTON OK-WASHINGTON AR-
503 AM CDT FRI AUG 13 2010

...EXCESSIVE HEAT TO CONTINUE THROUGH SATURDAY...

THIS OUTLOOK IS FOR NORTHWEST AND WEST CENTRAL ARKANSAS AS WELL AS
MUCH OF EASTERN OKLAHOMA.

.DAY ONE...TODAY AND TONIGHT.

SEVERE THUNDERSTORM.
	RISK...LIMITED.
	AREA...EXTREME EASTERN OKLAHOMA...WEST CENTRAL AND NORTHWEST ARKANSAS.
	ONSET...THIS AFTERNOON.

DANGEROUS HEAT.
	RISK...SIGNIFICANT.
	AREA...MUCH OF EASTERN OKLAHOMA AND WEST CENTRAL ARKANSAS.
 	ONSET...MIDDAY AND AFTERNOON.

 AREA AT GREATEST RISK...THE ARKANSAS RIVER VALLEY FROM TULSA TO
 	FORT SMITH...WHERE HEAT INDICES WILL CLIMB INTO THE 110 TO 115
	DEGREE RANGE THIS AFTERNOON.

FIRE WEATHER DANGER.
	RISK...ELEVATED...SPREADINDEX=49.
	AREA...EASTERN OKLAHOMA.
	ONSET...THIS AFTERNOON.

DISCUSSION...

THE HEAT AND HUMIDITY WILL COMBINE TO PRODUCE EXCESSIVE HEAT
INDICES IN THE 110 TO 115 DEGREE RANGE THIS AFTERNOON. AN ISOLATED
THUNDERSTORM IS ALSO POSSIBLE OVER EXTREME EASTERN OKLAHOMA...WEST
CENTRAL AND NORTHWEST ARKANSAS. LIGHTNING AND ISOLATED SEVERE WIND
GUSTS WILL BE THE PRIMARY HAZARDS FROM ANY STORMS THAT DEVELOP.

FUELS HAVE CURED ACROSS EASTERN OKLAHOMA DUE TO THE EXTENDED HOT
AND DRY PERIOD OF LATE. THE FIRE DANGER HAS INCREASED INTO THE
ELEVATED RANGE AS A RESULT.

SPOTTER AND EMERGENCY MANAGEMENT ACTION STATEMENT...
LOCAL SPOTTER ACTIVATION MAY BE NEEDED.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.
SATURDAY THRU MONDAY...THUNDERSTORM AND DANGEROUS HEAT POTENTIAL.
TUESDAY...THUNDERSTORM POTENTIAL.
WEDNESDAY...THUNDERSTORM AND DANGEROUS HEAT POTENTIAL.
THURSDAY...DANGEROUS HEAT POTENTIAL.

EXTENDED DISCUSSION...

THE EXCESSIVELY HOT WEATHER WILL CONTINUE THROUGH AT LEAST
SATURDAY...BEFORE A COLD FRONT MOVES INTO THE REGION SUNDAY. THIS
FRONT WILL BRING COOLER TEMPERATURES AND A CHANCE OF THUNDERSTORMS
THROUGH THE MIDDLE OF NEXT WEEK. THE HEAT MAY RETURN TOWARD THE
LATTER PART OF THE WEEK AS AN UPPER RIDGE REBUILDS OVER THE REGION.

WWW.SRH.NOAA.GOV/TULSA CONTAINS ADDITIONAL INFORMATION.