000
FXUS65 KBOU 111718
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1118 AM MDT SAT MAY 11 2013

.UPDATE...


&&

.SHORT TERM...WEAK CONVECTION CURRENTLY OVER THE NORTHEAST CORNER
AND LARIMER COUNTY. CELLS ARE MOVING SOUTHEASTWARD TODAY. 12Z
MORNING SOUNDING NOT AS MOIST AS YESTERDAY`S 12Z MODEL RUNS
ELUDED TO. NOT A LOT TO PICK UP ON ACCORDING TO THE WATER VAPOR
PICTURES CONCERNING HELP FOR CONVECTION LATER THIS AFTERNOON.
THERE IS SOME CAPE PROGGED THIS AFTERNOON AND EVENING ON ALL THE
MODELS...BUT NOTHING SUBSTANTIAL. WILL LEAVE POPS ALONG FOR NOW.
TEMPERATURES LOOK OK.

.AVIATION...WINDS AT DIA ARE LIGHT EAST TO SOUTHEAST AS EARLIER
ADVERTISED. MAY PUT A TEMPO GROUND IN FOR SHOWERS FOR THE 18Z
TAFS. THE TS HOWEVER...AT LEAST NOT YET. THE LOWER CEILINGS SHOULD
BE DONE BY 04Z THIS EVENING. LESS...TO NO...CONVECTION FOR SUNDAY
AFTERNOON.

&&

.PREV DISCUSSION... /ISSUED 349 AM MDT SAT MAY 11 2013/

SHORT TERM...NORTH/NORTHWEST FLOW ALOFT WILL REMAIN ACROSS THE
FORECAST AREA TODAY. A WEAK COLD FRONT HAD PUSHED SOUTHWARD EARLY
THIS MORNING...AND A FEW SPRINKLES HAD DEVELOPED BEHIND THE FRONT.
THESE SPRINKLES MAY CONTINUE EARLY THIS MORNING...WHILE THE
AIRMASS WILL THEN GRADUALLY DESTABILIZE WITH SCATTERED SHOWERS AND
THUNDERSTORMS DEVELOPING THIS AFTERNOON. COVERAGE SHOULD BE A
LITTLE HIGHER THAN YESTERDAY WITH A VERY SLIGHT INCREASE IN
MOISTURE AND JUST VERY WEAK Q-G LIFT OCCURRING TODAY. CAPES ONLY
200-400 J/KG...BUT CANT RULE OUT SMALL HAIL WITH RELATIVELY LOW
FREEZING LEVELS. STILL EXPECT A LITTLE SNOW ABOVE 11500-12000
FEET WITH SPOTTY ACCUMULATIONS.

FOR TONIGHT...SHOWERS AND STORMS WILL DECREASE AS THE AIRMASS
STABILIZES THIS EVENING. THERE IS STILL SOME WEAK Q-G LIFT
ADVERTISED OVER THE NORTHEAST CORNER OVERNIGHT SO WILL KEEP A LOW
THREAT OF SHOWERS LINGERING THERE.

LONG TERM...MODELS CONTINUE TO SHOW A STRONG AND WARM UPPER RIDGE
MOVING OVER THE STATE EARLY IN THE WEEK AND THEN MORE ZONAL FLOW
AND LESS RIDGING FOR THE REST OF THE WEEK. MONDAY AND TUESDAY WILL
BE THE WARMEST DAYS OF THE WEEK...BUT NOT QUITE AS WARM AS THE MOS
GUIDANCE FROM THE GFS HAS BEEN ADVERTISING. STILL TEMPERATURES IN
THE MID 80S WILL BE QUITE THE CONTRAST TO THE CHILLY TEMPERATURES
OF THE PAST SEVERAL TUESDAYS ACROSS NORTHEAST COLORADO. TUESDAY
NIGHT WILL SEE THE PASSAGE OF A SHORT WAVE WHICH USHERS IN SOME
COOLER AIR INTO THE FORECAST AREA. HIGH TEMPERATURES ON WEDNESDAY
SHOULD BE 10 TO 15 DEGREES COOLER THAN TUESDAY AFTERNOON. THE
LATTER HALF OF THE WEEK WILL SEE GRADUAL WARMING AGAIN...WITH
HIGHS ON THE PLAINS MAKING IT BACK TO THE LOWER 80S.

THE OTHER FEATURE OF THE FORECAST WILL BE A SLIGHT CHANCE OF
AFTERNOON AND EVENING SHOWERS OR THUNDERSTORMS...JUST ABOUT EVERY
AFTERNOON. MONDAY WILL SEE THE LEAST SHOWER ACTIVITY...SINCE THE
AIRMASS WILL BE AT ITS DRIEST. BY TUESDAY...MID-LEVEL MOISTURE
WILL BE RETURNING TO THE MOUNTAINS AHEAD OF THE UPPER TROUGH WHICH
WILL ALLOW SHOWER ACTIVITY TO BEGIN INCREASING AGAIN. FOR THE REST
OF THE WEEK...DAYTIME HEATING AND THE PRESENCE OF LOW AND MID-
LEVEL MOISTURE WILL FUEL AFTERNOON SHOWERS...PRIMARILY OVER THE
MOUNTAINS...BUT ALSO SPREADING OFF THE FOOTHILLS TO THE PLAINS AT
TIMES. DYNAMIC FORCING WITH THIS FLOW PATTERN SHOULD BE RELATIVELY
WEAK...SO THERE DOES NOT APPEAR TO BE ANY THREAT OF SEVERE
WEATHER.

AVIATION...MID LEVEL CLOUD DECK IS BECOMING MORE WIDESPREAD
ACROSS THE FRONT RANGE EARLY THIS MORNING. THERE WILL EVEN BE A
FEW SPRINKLES/VERY LIGHT SHOWERS POSSIBLE WITH NO RESTRICTION TO
VISIBILITY...BUT A CHANCE OF ILS LANDING DUE TO POTENTIAL CEILINGS
OF 4000-6000 FEET. VISUAL LANDING CONDITIONS WILL STILL PREVAIL
THROUGH THE PERIOD. CHANCE OF THUNDERSTORMS FROM 19Z-02Z BUT
CONFIDENCE OF THUNDER AND TIMING OF THUNDER IS NOT HIGH ENOUGH FOR
A TEMPO PERIOD AT THIS TIME. NORTHWESTERLY WINDS WILL LIKELY SHIFT
MORE EASTERLY BY 15Z-18Z WITH POSSIBLE VARIABLE GUSTS TO 25-30
KTS NEAR ANY SHOWERS/STORMS THIS AFTERNOON. SKIES WILL GRADUALLY
CLEAR OVERNIGHT WITH TYPICAL DRAINAGE WINDS DEVELOPING.

HYDROLOGY...STORMS WILL BE MOVING AROUND 20 MPH AND PRECIPITABLE
WATER VALUES WILL BE SIMILAR TO JUST A FEW HUNDREDTHS HIGHER THAN
YESTERDAY. STRONGER STORMS MAY PRODUCE A QUICK QUARTER INCH OF
RAIN BUT NOT ENOUGH TO CAUSE FLOODING CONCERNS AT THIS TIME. WE
WILL BE KEEPING AN EYE ON MOUNTAIN STREAM LEVELS THROUGH THE WEEK
AS SNOWMELT BEGINS IN EARNEST MONDAY.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...BARJENBRUCH
LONG TERM....DANKERS
AVIATION...BARJENBRUCH