Discussion scientifique du spécialiste des prévisions météorologiques

NWS Discussion
			
				
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DODGE CITY KS
359 PM CDT THU MAY 23 2013

...UPDATED FOR LONG TERM DISCUSSION...

.SYNOPSIS...
ISSUED AT 355 PM CDT THU MAY 23 2013

THIS MORNING'S UPPER AIR ANALYSIS SHOWED WEAK RIDGING ALOFT OVER THE 
CENTRAL PLAINS BETWEEN AN EXITING UPPER LEVEL TROUGH OVER THE GREAT 
LAKES AND MID MISSISSIPPI VALLEY AND A STRONG UPPER LEVEL LOW 
PRESSURE SYSTEM SPINNING OVER THE PACIFIC NORTHWEST. SOUTHWESTERLY 
FLOW ALOFT WAS OVER THE DESERT SOUTHWEST INTO THE CENTRAL ROCKIES. 
WEAK DISTURBANCES WERE MOVING THROUGH THIS FLOW INTO THE CENTRAL 
HIGH PLAINS AND RESULTED IN SOME ELEVATED SHOWERS AND THUNDERSTORMS 
ACROSS WESTERN AND CENTRAL KANSAS EARLIER THIS MORNING. AT THE 
SURFACE, A FRONTAL BOUNDARY EXTENDED ALONG THE RED RIVER VALLEY INTO 
NORTHWEST TEXAS BEFORE ANGLING BACK TO THE NORTHWEST ALONG THE 
COLORADO FRONT RANGE. MODEST LOW LEVEL MOISTURE RETURN HAS BEEN 
OCCURRING OVERNIGHT AND TODAY ACROSS THE SOUTHERN AND CENTRAL HIGH 
PLAINS.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 355 PM CDT THU MAY 23 2013

WITH A FAIRLY COOL AIRMASS INVADING THE CENTRAL HIGH PLAINS, THE 
LOWER LEVELS HAVE BECOME FAIRLY STABLE ACROSS CENTRAL AND WESTERN 
KANSAS. SOME ELEVATED SHOWERS AND ISOLATED THUNDERSTORMS HAVE 
REDEVELOPED OVER SOUTH CENTRAL KANSAS THIS AFTERNOON AHEAD OF A WEAK 
UPPER DISTURBANCE. EXPECT THIS ACTIVITY TO GRADUALLY SHIFT EAST OF 
THE PRATT/MEDICINE LODGE AREA BY EARLY THIS EVENING BUT CHANCES FOR 
SHOWERS AND THUNDERSTORMS WILL GRADUALLY SPREAD NORTH ACROSS WESTERN 
KANSAS OVERNIGHT AS ANOTHER WEAK WAVE MOVES INTO WESTERN KANSAS FROM 
THE SOUTHWEST TONIGHT. WILL CARRY A CHANCE FOR SHOWERS AND ISOLATED 
THUNDER IN THE FORECAST FOR TONIGHT. MODEL SOUNDINGS SHOW THE 
BOUNDARY LAYER MOISTENING UP OVERNIGHT. WHILE THERE COULD BE SOME 
REDUCTIONS IN VISIBILITY WITH MIST, THERE SHOULD BE ENOUGH TURBULENT 
MIXING OVERNIGHT TO KEEP WIDESPREAD FOG FROM BECOMING AN ISSUE. WITH 
WIDESPREAD CLOUD COVER, EXPECT LOW TEMPERATURES TO RANGE FROM THE 
LOWER 50S AROUND HAYS TO NEAR 60 AT LIBERAL.

BY FRIDAY MORNING, SCATTERED SHOWERS AND A FEW THUNDERSTORMS SHOULD 
BE ONGOING GENERALLY EAST OF HIGHWAY 283 AND SHOULD CONTINUE TO 
GRADUALLY MOVE EAST OUT OF CENTRAL KANSAS BY AFTERNOON. AN UPPER 
DISTURBANCE IS PROGGED TO SWING THROUGH THE SOUTHERN QUADRANT OF THE 
PACIFIC NORTHWEST LOW AND OUT TOWARD THE NORTHERN HIGH PLAINS DURING 
THE AFTERNOON. THE NAM SHOWS THE WARM FRONT LIFTING BACK NORTHWARD 
THROUGH WESTERN KANSAS WITH A DRYLINE FORMING JUST WEST OF THE 
KANSAS/COLORADO BORDER. EXPECT TO SEE SOME WIDELY SCATTERED 
THUNDERSTORMS DEVELOPING ALONG THE DRYLINE IN THE AFTERNOON AND
POSSIBLY MOVING INTO FAR WESTERN KANSAS. THE NAM IS SHOWING AROUND
2000 J/KG OF CAPE WITH 40 KNOTS OF 0-6KM SHEAR WHICH WOULD SUPPORT
A FEW SUPERCELLS WITH WITH LARGE HAIL.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 357 PM CDT THU MAY 23 2013

UPPER LEVEL TROUGHING WILL REMAIN BACK OVER THE WESTERN UNITED STATES
THROUGH MID NEXT WEEK. HOWEVER, THERE ARE SOME DIFFERENCES IN THE
MODELS, WITH THE ECMWF MORE CLOSED OFF AND FURTHER SOUTH AND THE 
GEM/GFS/UKMET MORE PROGRESSIVE. ISOLATED TO SCATTERED THUNDERSTORMS 
ARE POSSIBLE THROUGH MONDAY AND SOME OF THESE COULD BE SEVERE WITH 
LARGE HAIL GIVEN THE FAIRLY HIGH SURFACE BASED CAPE AND MARGINAL
SHEAR PROFILE. CHANCES FOR TORNADOES AND GIANT HAIL LOOK FAIRLY LOW 
DUE TO EXPECTED HIGH DEWPOINT DEPRESSIONS AND FAIRLY WEAK WINDS IN 
THE UPPER TROPOSPHERE. AFTER MONDAY, THE MORE PROGRESSIVE SOLUTION 
WOULD RESULT IN CONTINUED CHANCES FOR THUNDERSTORMS (SOME SEVERE), 
BUT ESPECIALLY FOR CENTRAL AND SOUTH CENTRAL KANSAS. THE ECMWF WOULD 
RESULT IN A MOIST AXIS THAT IS FURTHER WEST, WITH BETTER CHANCES FOR 
STORMS (POSSIBLY SEVERE) IN FAR WESTERN KANSAS. HIGH TEMPERATURES 
SHOULD BE IN THE UPPER 80S TO 90S, WITH THE WARMEST READINGS 
IMMEDIATELY WEST OF THE DRYLINE IN FAR WESTERN KANSAS WHERE 
DOWNSLOPE SOUTHWEST WINDS AND DRY CONDITIONS WILL BE PRESENT.
CRITICAL FIRE WEATHER CONDITIONS MAY EXIST SUNDAY AND MONDAY 
IN FAR WESTERN KANSAS BEHIND THE DRYLINE. LOW TEMPERATURES WILL BE 
HIGHEST IN CENTRAL AND SOUTH CENTRAL KANSAS (UPPER 60S) EACH MORNING 
THROUGH WEDNESDAY DUE TO HIGHER DEWPOINTS AND BREEZY SOUTH WINDS IN 
THAT AREA. HOWEVER, IF THE MOIST AXIS ENDS UP BEING FURTHER WEST, 
THEN VERY MILD OVERNIGHT LOWS WOULD EXTEND AS FAR WEST AS THE 
COLORADO BORDER.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1237 PM CDT THU MAY 23 2013

STRATUS WILL CONTINUE TO DEVELOP ACROSS SOUTHWEST INTO CENTRAL
KANSAS AND COULD MIX OUT INTO A BROKEN VF/MVFR CUMULUS DECK
THROUGH THE AFTERNOON HOURS. CIGS ARE EXPECTED TO DROP INTO LOWER
MVFR AND POSSIBLY IFR CATEGORIES AFTER 06Z TONIGHT ESPECIALLY AT
GARDEN CITY AND DODGE CITY. WIDELY SCATTERED SHOWERS AND POSSIBLY
SOME THUNDERSTORMS COULD ALSO DEVELOP LATER TONIGHT. FOR NOW WILL
MENTION VCTS IN THE TAFS TO ACCOUNT FOR THIS.


&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  56  77  63  90 /  40  30  30  20 
GCK  57  81  63  92 /  40  20  30  30 
EHA  58  85  61  92 /  30  30  30  30 
LBL  60  83  64  92 /  30  20  30  30 
HYS  54  73  62  91 /  40  40  30  20 
P28  55  75  65  87 /  40  40  30  20 

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...GERARD
SHORT TERM...GERARD
LONG TERM...FINCH
AVIATION...GERARD