000
FXUS65 KBOU 242103
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
303 PM MDT FRI APR 24 2015

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 302 PM MDT FRI APR 24 2015

UPPER SHORT WAVE TROUGH CURRENTLY OVER THE STATE HELPING SPARK
CONVECTION THIS AFTERNOON. LESS WIND ALOFT COMPARED TO YESTERDAY
WILL KEEP STORMS WEAKER. COULD STILL SEE SOME SMALL HAIL OVER THE
EASTERN CO PLAINS WHERE THE JET OVER KANSAS COULD STILL HAVE AN
INFLUENCE. THE UPPER TROUGH AXIS IS PROGGED TO SHIFT EAST INTO
KANSAS LATE THIS AFTERNOON INTO EARLY EVENING...WHICH SHOULD
DECREASE ACTIVITY DURING THE SAME TIME. AS THE SURFACE TROUGH AND
UPPER SYSTEM PUSH FURTHER INTO THE GREAT PLAINS AND HIGH SURFACE
PRESSURE BUILDS IN SOUTHWESTERN COLORADO AS RIDGING ALOFT MOVES
OVERHEAD...EXPECT SOME GUSTY DOWNSLOPE WINDS ALONG AND OVER THE
FRONT RANGE FOOTHILLS. GUSTY WEST WINDS OF 35 TO 50 MPH WILL BLOW
OVERNIGHT THOUGH THE NORMAL WINDY CHANNELED AREAS.

UPPER RIDGE WILL HOLD OVER THE AREA SATURDAY MORNING BEFORE FLOW
ALOFT TURNS MORE SOUTHWESTERLY AS A SYSTEM DIGS INTO THE GREAT
BASIN. MOISTURE ADVECTING INTO THE STATE WILL ALLOW FOR ISOLATED
SHOWERS OVER THE MOUNTAINS IN THE MORNING. A SURFACE LOW OVER THE
NORTHEAST PLAINS WILL PUSH SOUTH WITH A WEAK COOL FRONT FOLLOWING
BEHIND FOR LOW LEVEL MOISTURE ADVECTING IN FROM THE GREAT PLAINS.
SHOWERS WILL INCREASE IN COVERAGE IN THE AFTERNOON WITH
THUNDERSTORMS EMBEDDED ACROSS THE ENTIRE AREA. AN AREA OF HIGHER
CAPES TO MOVE IN FROM THE EAST FOR A SLIGHT CHANCE FOR STRONGER
STORMS MAINLY OVER THE FAR NORTHEASTERN CORNER OF THE STATE.
TEMPERATURES WILL BE SIMILAR TO TODAY.

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 302 PM MDT FRI APR 24 2015

SHOWERS AND THUNDERSTORMS WILL EXPAND IN COVERAGE SATURDAY EVENING
AS THE STRONG SHORT WAVE TROUGH DIGS ACROSS THE GREAT BASIN. Q-G
LIFT WILL INCREASE AHEAD OF THIS FEATURE WHILE AT THE SAME TIME A
SURFACE CONVERGENCE BOUNDARY OVER THE PLAINS COULD ACT TO SERVE AS
A FOCUSING MECHANISM. STORM INTENSITY MAY INCREASE AS WELL BUT
RIGHT NOW INSTABILITY IS EXPECTED TO BE LIMITED TO JUST A FEW
HUNDRED J/KG.

THE LOW LEVEL BOUNDARY IS EXPECTED TO GRADUALLY PUSH BACK TOWARD
THE FRONT RANGE LATER SATURDAY NIGHT INTO SUNDAY MORNING. AS THIS
FEATURE CONTINUE TO BACK INTO THE FRONT RANGE...A HOST OF
PARAMETERS WILL COME TOGETHER TO PRODUCE MORE WIDESPREAD RAIN FOR
SUNDAY. UPSLOPE FLOW WILL DEEPEN AND STRENGTHEN AS THE LOW LEVEL
BOUNDARY PUSHES INTO THE FRONT RANGE AND THE UPPER LOW CUTS OFF IN
NORTHEAST ARIZONA. THE AIRMASS IS QUITE MOIST THROUGH THE COLUMN
WITH HIGH 700-500 MB SPECIFIC HUMIDITY AROUND 3 G/KG...AND
PRECIPITABLE WATER VALUES NEAR 0.60 INCH ON THE PLAINS. AS A
RESULT...ANY UPSLOPE COMPONENT SHOULD BE AN EFFICIENT
PRECIPITATION PRODUCER IN A NEARLY NEUTRAL/SLIGHTLY UNSTABLE
THERMODYNAMIC PROFILE. CANT EVEN RULE OUT SOME THUNDER IN THE MORE
WIDESPREAD RAIN EXPECTED ALONG THE FRONT RANGE THROUGH SUNDAY
AFTERNOON. SNOW LEVELS WILL START OFF QUITE HIGH SUNDAY...NEAR
9000-9500 FEET...AND WILL ONLY LOWER MODESTLY TO AROUND 7000 FEET
BY LATE SUNDAY NIGHT INTO MONDAY MORNING PER LATEST WET BULB ZERO
LEVELS. THE UPPER LOW IS EXPECTED TO SINK FAR ENOUGH SOUTH BY
MONDAY FOR THE MORE SIGNIFICANT PRECIPITATION TO SHIFT SOUTHWARD
INTO SOUTHEAST COLORADO OR NORTHERN NEW MEXICO. AT THIS
TIME...THERE IS STILL POTENTIAL FOR WINTER HIGHLIGHTS IN THE
MOUNTAINS AND HIGHEST FOOTHILLS MAINLY ABOVE 8000-8500 FEET LATE
SUNDAY INTO LATE SUNDAY NIGHT OR MONDAY MORNING.

IT SHOULD BE NOTED THERE IS RATHER GOOD AGREEMENT AMONGST THE
MEDIUM RANGE MODELS CONCERNING THE LOW POSITION. HOWEVER...CONSIDERING
THE MAIN STORM ENERGY IS STILL OFFSHORE WE WILL HAVE TO WATCH FOR
FURTHER TRACK ADJUSTMENTS. AS LONG AS THE STORM TRACK STAYS TO OUR
SOUTH AS GENERALLY AGREED UPON THEN THE HEAVIEST PRECIP WILL ALSO
STAY IN SOUTHEAST COLORADO/NORTHEAST NEW MEXICO. AT THIS POINT
GIVEN THE CURRENT EXPECTED TRACK...WE SHOULD SEE HEALTHY PRECIP
AMOUNTS...GENERALLY AVERAGING AROUND 0.75 TO 1 INCH ACROSS THE
PLAINS WITH LOCAL AMOUNTS UP TO 1.5 INCHES LIQUID EQUIVALENT IN
THE FOOTHILLS/FRONT RANGE MOUNTAINS.

BY TUESDAY...THERE SHOULD BE A WEAK WAVE DROPPING IN THE BACK SIDE
OF THE STORM WHICH WOULD KEEP A FEW SHOWERS IN THE FORECAST.

DRY WEATHER IS THEN EXPECTED WEDNESDAY OVER THE FORECAST AREA AS
UPPER RIDGE BUILDS INTO THE REGION. ENOUGH MOISTURE MAY BUBBLE UP
UNDER THE RIDGE FOR THURSDAY AND FRIDAY FOR A FEW SHOWERS AND
STORMS...MAINLY IN THE MOUNTAINS. TEMPERATURES WILL CERTAINLY
MODERATE THROUGH THIS PERIOD WITH READINGS ABOVE NORMAL AGAIN FOR
WEDNESDAY THROUGH FRIDAY.

&&

.AVIATION...(FOR THE TAFS THROUGH 00Z SATURDAY LATE AFTERNOON)
ISSUED AT 302 PM MDT FRI APR 24 2015

VFR CONDITIONS OVER THE NEXT 24 HOURS. NORTHERLY WINDS ACROSS THE
TERMINALS SHOULD TRANSITION TO NORTHWEST/WESTERLY THIS EVENING.
A FEW SHOWERS AND THUNDERSTORMS OVER THE FOOTHILLS WILL MOVE EAST
SOUTHEAST OVER THE PLAINS WITH THE BEST CHANCE TO AFFECT KBDU AND
NORTH...AS WELL AS THE SOUTH METRO AREA INCLUDING KAPA. ANOTHER
MAY SKIRT JUST TO THE SOUTH OF KBJC. KDEN MAY JUST ESCAPE THE
ACTIVITY. WILL CONTINUE TO KEEP TSTMS OUT OF THE TAFS...BUT MAY
NEED TO ADD THEM IN FOR KAPA LATER...POSSIBLY FOR KBJC EARLIER.
THESE STORMS WILL BE SHORT LIVED AND MAINLY PRODUCE LIGHT RAIN
AND WESTERLY WINDS TO THE TERMINALS. DOWNSLOPING PATTERN OFF THE
HIGH TERRAIN IS EXPECTED TONIGHT...WHICH COULD PRODUCE GUSTY
WESTERLY WINDS TO 35 KTS NEAR KBJC AFTER MIDNIGHT AS WELL AS SOME
HIGH MOUNTAIN WAVE CLOUDS.

LIGHT WINDS SATURDAY MORNING WILL BECOME NORTHERLY IN THE
AFTERNOON AS A WEAK FRONT PUSHES SOUTH. INCREASING MOISTURE WILL
SLOWLY LOWER CEILINGS WITH SHOWERS INCREASING LATE AFTERNOON.

&&

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

$$

SHORT TERM...KRIEDERMAN
LONG TERM...BARJENBRUCH
AVIATION...KRIEDERMAN

NWS BOU Office Area Forecast Discussion