Scientific Forecaster Discussion

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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
846 PM MDT THU APR 24 2014

.UPDATE...
ISSUED AT 846 PM MDT THU APR 24 2014

NO SIGNIFICANT ADJUSTMENTS AT THIS TIME...CURRENT FORECAST LOOKS
GOOD.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 347 PM MDT THU APR 24 2014

UPPER LEVEL RIDGE CURRENTLY OVER THE GREAT BASIN WITH NORTHWEST
FLOW ALOFT ACROSS COLORADO. WEST TO NORTHWEST WINDS CONTINUING
ACROSS MUCH OF THE AREA...WITH SOME GUSTS TO 35 MPH ALONG THE
HIGHER MOUNTAINS AND FOOTHILLS. WINDS WEAKER IN DENVER AREA WITH
PRESENCE OF AN ANTICYCLONE....WITH DIRECTION MAINLY SOUTHEAST.
HIGH LEVEL MOISTURE CURRENTLY MOVING ACROSS THE AREA. RIDGE
EXPECTED TO MOVE ACROSS THE STATE TONIGHT. FLOW ALOFT WILL
DECREASE...LEADING TO A DECREASE IN SURFACE WINDS. SATELLITE
SHOWING NEXT BATCH OF MAINLY HIGH LEVEL MOISTURE OVER UTAH...WILL
BE MOVING OVER THE AREA TONIGHT. AFTER A BRIEF BREAK SHOULD SEE
HIGH LEVEL CLOUDS INCREASE AGAIN. LATEST CIRRA SYNTHETIC SATELLITE
IMAGERY SUGGESTING A FAIRLY EXTENSIVE WAVE CLOUD ALONG THE
FOOTHILLS AND URBAN CORRIDOR TOWARDS MORNING. DID ADJUST SKY GRIDS
A BIT. ON FRIDAY...FLOW ALOFT TO BECOME SOUTHWEST AS UPPER TROUGH
BEGINS TO MOVE INTO THE GREAT BASIN. SURFACE LEE TROUGH DEVELOPS
ACROSS THE EASTERN PLAINS DURING THE AFTERNOON. COMBINATION OF
WARM AIR ADVECTION AND SOUTHERLY WINDS WILL HELP BOOST
TEMPERATURES INTO THE 70S ACROSS THE PLAINS. GUSTY SOUTHERLY WINDS
WILL ALSO HELP LOWER HUMIDITY READINGS ACROSS THE
AREA...ESPECIALLY ALONG THE PALMER DIVIDE INTO LINCOLN COUNTY.
THIS WILL INCREASE THE FIRE DANGER A BIT BUT RECENT PRECIPITATION
AIDING IN CONTINUED GREENUP. SOUTHERN LINCOLN COUNTY ONLY AREA AT
THIS TIME WHERE FIRE WEATHER CONDITIONS COULD GET CRITICAL...BUT
LOOKS MARGINAL AT BEST. 

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 224 PM MDT THU APR 24 2014

FRIDAY NIGHT WILL BE ANOTHER MILD NIGHT...ESPECIALLY ALONG THE
FOOTHILLS AND ADJACENT PLAINS...AS SOUTHWEST FLOW ALOFT AND A
DEEPENING SURFACE LEESIDE LOW WILL DEEPEN OVER THE FAR EASTERN
PLAINS.

SOUTHWEST FLOW ALOFT WILL TURN MORE SOUTHERLY AS AN UPPER LOW OVER
THE SOUTHERN GREAT BASIN MOVES TO NEAR THE FOUR CORNERS REGION BY
EVENING. WARM ADVECTION WILL INCREASE HIGH TEMPERATURES SATURDAY
WITH UPPER 70S TO LOWER 80S. DRY SOUTHERLY WINDS WILL BE
INCREASING OVER THE PLAINS AS WELL...INCREASING FIRE DANGER TO
POSSIBLE CRITICAL LEVELS. THEREFORE A FIRE WEATHER WATCH WILL BE
ISSUED FOR LINCOLN COUNTY AND EASTERN ELBERT COUNTY. THIS WATCH
MAY NEED TO BE EXTENDED INTO WASHINGTON COUNTY.

MOISTURE WILL BEGIN TO MOVE INTO WESTERN COLORADO AND THE
MOUNTAINS LATE SATURDAY MORNING WITH ISOLATED SHOWERS HAVING SNOW
LEVELS NEAR 10000 FT. MODERATE QG LIFT AHEAD OF THE STORM WILL
THEN MOVE OVERHEAD TO INCREASE SHOWERS IN COVERAGE WITH A SLIGHT
CHANCE OF SHOWERS OVER THE PLAINS AS WELL...MAINLY NORTH OF I76.
MODELS SHOWING CAPE SPREADING OVER THE AREA FOR A SLIGHT CHANCE OF
THUNDERSTORMS AS WELL...BUT LIKELY WILL HOLD OFF UNTIL LATER IN
THE AFTERNOON. THE RECENT MODEL RUNS HAVE SHOWN GOOD RUN TO RUN
CONSISTENCY IN THE GFS AND THE NAM AND ECMWF HAS NOW COME MORE IN
LINE WITH THE GFS. THIS SOLUTION WILL TAKE THE FOUR CORNERS LOW
AROUND 00Z EAST ACROSS SOUTHERN COLORADO AND NEAR THE KANSAS
BORDER BY 12Z SUNDAY MORNING. THE COLD FRONT WILL SPREAD EAST
ACROSS THE STATE SATURDAY EVENING WITH SNOW LEVELS LOWERING TO
ABOUT 6-7 THOUSAND FEET BY SUNDAY MORNING. THE MOUNTAINS WILL
LIKELY RECEIVE GOOD SNOW STARTING SATURDAY EVENING AND IN THROUGH
SUNDAY AFTERNOON AS FLOW TURNS NORTHWESTERLY BEHIND THE TROUGH.
WITH THE INITIAL WARM TEMPERATURES AND EXPECTED MELTING BEFORE THE
MAIN FRONT...OVERALL SEE ONLY ADVISORY SNOWFALL AMOUNTS (6-12
INCHES IN 24 HOURS) FOR THE HIGH TERRAIN. NO WINTER STORM WATCH
WILL BE ISSUED FOR NOW DUE TO LOWER THAN WARNING CRITERIA
AMOUNTS...HOWEVER WILL NEED TO KEEP AN EYE ON DEVELOPING STORM AND
POSSIBLE HIGHER AMOUNTS FROM CONVECTION. 

AS FOR THE PLAINS...DRY AIR AHEAD OF THE SYSTEM AND POTENTIAL
POSITION OF THE SURFACE LOW WILL KEEP MOST OF THE PLAINS DRY UNTIL
LATE EVENING WHEN THE 700 MB LOW MOVES EAST ALONG THE FRONT RANGE
AND QG VERTICAL VELOCITIES ARE PROGGED TO INCREASE TO NEAR 40
MB/HR OF UPWARD MOTION. EVEN THOUGH THE SURFACE LOW CURRENTLY
PROGGED WITH TEND TO DOWNSLOPE US OUT...ITS HARD TO IGNORE THE QG
PARAMETERS. WILL INCREASE POPS TO CHANCES AND LIKELYS ACROSS THE
PLAINS SATURDAY NIGHT WITH ALMOST ALL RAIN EXPECTED...EXCEPT SOME
SNOW POSSIBLE OVER THE PALMER DIVIDE. IT DOES NOT LOOK LIKE THE
INGREDIENTS WILL BE OVER OUR AREA FOR ANY SEVERE STORMS - FURTHER
EAST INTO KANSAS. HOWEVER EARLY SUNDAY MORNING COULD BE A
POTENTIAL TIME FRAME FOR THUNDERSTORMS OVER THE FAR NORTHEAST
CORNER. THIS IS SHOWN BY WRAPAROUND MOISTURE...A Theta-e RIDGE AND
FORECAST SOUNDINGS SHOWING GOOD ELEVATED INSTABILITY. 

THE ALMOST STACKED LOW IS PROGGED TO MOVE NORTH-NORTHEAST INTO
NEBRASKA AND SOUTH DAKOTA SUNDAY NIGHT INTO MONDAY...DECREASING
PRECIPITATION CHANCES. STRONG WINDS ON THE BACKSIDE OF THE LOW
WILL KEEP TEMPERATURES FROM DIPPING TOO LOW SUNDAY NIGHT WITH ONLY
A FEW LOCATIONS MAYBE SEEING FREEZING OVER THE PLAINS. 

MODELS NOW EXTENDING THE NORTHWESTERLY FLOW ON THE BACKSIDE OF
THE LOW UNTIL WEDNESDAY NOW. THIS WILL BRING COOLER THAN NORMAL
TEMPERATURES ALONG WITH SOME LIGHT SNOW AND RAIN SHOWERS OVER THE
AREA. 

&&

.AVIATION...(FOR THE TAFS THROUGH 06Z FRIDAY EVENING)
ISSUED AT 846 PM MDT THU APR 24 2014

NO SIGNIFICANT ADJUSTMENTS PLANNED IN THE ONGOING TAFS. VFR
CONDITIONS OVER THE NEXT 24 HRS. DIURNAL WINDS EXPECTED THROUGH
18Z...THEN SWLY WINDS EXPECTED IN SATURDAY AFTN.

&&

.FIRE WEATHER...
ISSUED AT 224 PM MDT THU APR 24 2014

A FIRE WEATHER WATCH WILL BE ISSUED FOR EASTERN ELBERT AND LINCOLN
COUNTIES FOR SATURDAY AFTERNOON DUE TO POSSIBLE CRITICAL FIRE
WEATHER CONDITIONS. HUMIDITIES WILL BE IN THE 10-15% RANGE AND
WINDS ARE EXPECTED TO GUST BETWEEN 25 AND 35 MPH...MAINLY EAST OF
A LINE FROM KIOWA ON THE PALMER DIVIDE TO AKRON. RECENT
PRECIPITATION LAST NIGHT OVER DOUGLAS...WESTERN ELBERT...EASTERN
ADAMS AND ARAPAHOE AND WESTERN WASHINGTON COUNTIES HAVE KEPT THESE
AREAS OUT OF THE WATCH FOR NOW...EVEN THOUGH CONDITIONS WILL BE
NEAR THE SAME. WILL HAVE TO REVISIT TOMORROW TO SEE IF FUELS HAVE
BECOME DRY ENOUGH TO EXPAND THE WATCH TO THESE AREAS. 

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY 
EVENING FOR COZ246-247.

&&

$$

UPDATE...COOPER
SHORT TERM...D-L
LONG TERM...KRIEDERMAN
AVIATION...COOPER
FIRE WEATHER...D-L/KRIEDERMAN