000
FXUS65 KBOU 110028
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
528 PM MST TUE DEC 10 2013

.UPDATE...


&&

.SHORT TERM...CRAZY WINDS JUST WON`T GO AWAY AS STRONGER WINDS
HAVE AGAIN INCREASED AGAIN ACROSS BOULDER AND NORTHERN JEFFERSON
COUNTIES. STRONG MOUNTAIN TOP STABILITY AND ENHANCED SUBSIDENCE
COMING DOWN FROM WYOMING SEEM TO BE THE CULPRIT FOR THE INCREASED
WINDS. DON`T EXPECT THE HIGH WINDS TO LAST PAST LATER THIS
EVENING DUE TO A FRONT MOVING INTO THE AREA WHICH WILL CONTINUEDDECREASE
THE SURFACE GRADIENT ACROSS THE STATE AND STRONGEST SUBSIDENCE
MOVE SOUTH OF THE WARNING AREA LATER THIS EVENING. HAVE ISSUED A
SHORT FUSED HIGH WIND WARNING FOR FOOTHILLS AND ADJ PLAINS UNTIL
10 PM THIS EVENING.

.AVIATION...SURFACE WINDS HAVE SHIFTED NORTHEAST AT DENVER AND NOW
JUST SHIFTING NORTHEAST INTO BJC AS THE FRONT MOVES IN. BOULDER
AIRPORT WILL SEE STRONG WINDS IN EXCESS OF 60 MPH UNTIL 8 PM THEN
DECREASING.

&&

.PREV DISCUSSION... /ISSUED 454 PM MST TUE DEC 10 2013/

UPDATE...ONE LAST BIG PUSH OF WIND OCCURRING ALONG THE FOOTHILLS
BEFORE THE WAVE DEPARTS UP TO HIGHER ELEVATIONS AS A COLD FRONTAL
PUSH MOVES IN FROM THE NORTHEAST. THE WINDS SHOULD BE DECREASING
WITHIN THE NEXT COUPLE OF HOURS AS THIS FRONT PUSHES IN. AREAS OF
BLOWING SNOW FROM THE GUSTY WINDS ARE DECREASING VISIBILITIES
ALONG THE FOOTHILLS AND TOWARD THE WYOMING BORDER...CAUSING
HAZARDOUS DRIVING CONDITIONS. THIS WILL BE SUBSIDING DURING THE
EVENING.

AVIATION...THE COLD FRONTAL PUSH OUT ON THE EASTERN PLAINS IS
EXPECTED TO PUSH INTO THE DEN AND APA AIRPORTS TO TURN THE NORTH-
NORTHWESTERLY WINDS AROUND TO THE EAST THEN SOUTH LATER TONIGHT.
BJC WILL CONTINUE BLOWING OUT OF THE WEST WITH GUSTS UP TO 40 MPH
FOR THE NEXT COUPLE HOURS BEFORE DIMINISHING...LIKELY TO LIGHT AND
VARIABLE FOR A SHORT TIME. WINDS STAYING SOUTH-SOUTHWEST THROUGH
18Z WITH LIGHT SPEEDS THEN BECOME SLIGHTLY WESTERLY AGAIN...SPEEDS
TO STAY BELOW 8 KTS. VFR TO CONTINUE WITH UNLIMITED CEILINGS.
LOWER AIRMASS WILL BE DRY SO NOT EXPECTING LOW CLOUDS OR FOG
OVERNIGHT.

PREV DISCUSSION... /ISSUED 341 PM MST TUE DEC 10 2013/

SHORT TERM...WINDS STILL QUITE GUSTY IN AND NEAR FOOTHILLS...
BEGINNING TO SHOW SOME DECREASE AS PRESSURE GRADIENT FROM GJT TO
DEN DECREASES AND WEAK LIFT FROM APPROACHING WAVE BEGINS TO OFFSET
THE DOWNWARD MOTION. CROSS MOUNTAIN FLOW AVERAGED AROUND 50 KTS
ACROSS THE NORTHERN FOOTHILLS FOR MUCH OF THE AFTERNOON...BASED ON
THE RAP ALONG WITH THE PERSISTENT MOUNTAIN WAVE. THE PRESSURE
GRADIENT FROM GJT TO DEN DID PEAK AT 15.16 MB AT 17Z. DID RECEIVE
A GUST TO 83 MPH AT LYONS AT 115 PM...APPEARS THIS STRONG WIND
GUST WAS CHANNELED ACROSS THIS AREA AND RATHER LOCALIZED. OTHER
GUSTS ALONG THE FOOTHILLS NOT NEARLY THAT STRONG...GENERALLY
AROUND 60 MPH. THE GUSTY DOWNSLOPE WINDS DID INCREASE TEMPERATURES
ACROSS THE URBAN CORRIDOR. STILL THINKING THE WINDS WILL BE ON
THE DECREASE BY THE EVENING ONCE THE AIRMASS STABILIZES AND
MOUNTAIN WAVE WEAKENS. SHORT TERM MODELS SHOW THE GJT TO DEN
PRESSURE GRADIENT DECREASING THROUGH THE EVENING... WITH THE CROSS
MOUNTAIN FLOW DECREASING TO AROUND 40 KTS NEAR MOUNTAIN TOP. MAY
STILL BE A BIT GUSTY IN AND NEAR THE FOOTHILLS. MOISTURE NOW
SPREADING INTO NORTHERN MOUNTAINS AS THE MID LEVEL DISTURBANCE
MOVES ACROSS WYOMING. WEAK MID LEVEL ASCENT AND OROGRAPHICS WITH
NORTHWEST FLOW ALOFT ENOUGH TO KEEP A CHANCE OF LIGHT SNOW FOR THE
NORTHERN MOUNTAINS. SNOW CHANCES DECREASE ACROSS CENTRAL
MOUNTAINS. LATEST MODEL QPF HAD DECREASED THE AMOUNT OF PRECIP AND
THUS SNOW AMOUNTS. SO ANY ACCUMULATIONS TO BE AROUND AN INCH OR
LESS... MAINLY ACROSS ZONE 31. ACROSS THE PLAINS...WEAK SURGE
STILL EXPECTED TO MOVE INTO THE AREA AROUND MIDNIGHT...DROPPING
TEMPERATURES BACK INTO THE SINGLE DIGITS DESPITE THE NICE WARMUP
THIS AFTERNOON. WINDS WILL BE WEAKENING DURING THE EVENING...AND
MAY BECOME EASTERLY FOR A SHORT TIME BEFORE GOING TO DRAINAGE
AROUND MIDNIGHT. CROSS SECTIONS DO NOT SHOW ANY LOW LEVEL MOISTURE
SO DO NOT THINK FOG OR LOW STRATUS WILL DEVELOP. MAY BE SOME MID
LEVEL CLOUD DURING THE EVENING. ON WEDNESDAY...THE NORTHWEST FLOW
ALOFT WILL CONTINUE THOUGH NOT AS STRONG AS TODAY. NAM CROSS
SECTIONS SHOWING CROSS MOUNTAIN FLOW AROUND 25-30 KTS. MAY SEE
SOME GUSTS AROUND 40 MPH OVER THE MOUNTAINS AND HIGHER FOOTHILLS.
ACROSS PLAINS...COOLER AIRMASS WILL BE IN PLACE...WITH HIGHS ONLY
IN THE LOWER 30S. ACTUALLY ABOUT 10 TO 15 DEGREES COOLER ALONG THE
URBAN CORRIDOR. AIRMASS WILL BE DRY WITH NO PRECIPITATION
EXPECTED. JUST SOME HIGH LEVEL MOISTURE DURING THE AFTERNOON.

LONG TERM...THE FLOW ALOFT WILL REMAIN NORTHWESTERLY WEDNESDAY NIGHT
WITH AN UPPER RIDGE TO THE NORTHWEST AND A WEAK TROUGH OFF THE SRN
CA/BAJA COAST.  THURSDAY INTO THURSDAY NIGHT...WEAK UPWARD ASCENT
WILL DEVELOP...AS THE CLOSED UPPER LOW SHIFT TO THE NORTH AND EAST.
THE MDLS EVENTUALLY MOVE THIS SYSTEM ACROSS SRN CO/NRN NEW MX LATE
THURSDAY NIGHT INTO FRIDAY...WITH A WEAK SECONDARY SYSTEM DROPPING
FM THE PAC NORTHWEST AND PASSING ACROSS WRN AND SRN CO LATE FRIDAY
INTO FRIDAY NIGHT.  SINCE BOTH OF THESE SYSTEMS ARE WEAK AND
GENERALLY PASSING TO THE WEST AND SOUTH OF THE CWFA...WL GO WITH
NO MORE THAN A CHANCE OF SNOW IN THE HIGH COUNTRY. THE BEST CHANCE
OF SNOW IN THE NRN MOUNTAINS APPEARS TO BE FRIDAY NIGHT...WITH THE
PASSAGE OF THE SECOND SYSTEM. ACROSS THE PLAINS...IT WILL REMAIN
DRY THROUGH THE PERIOD. IT WILL WARM INTO THURSDAY...WITH SLIGHTLY
COOLER TEMPERATURES (BUT STILL NEAR NORMAL) ON FRIDAY AND
SATURDAY...WITH TEMPERATURES EXPECTED WARM UP AGAIN SUNDAY AND
MONDAY. A LEE SIDE SURFACE TROUGH WILL DEVELOP OVER EASTERN CO
THURSDAY AFTN...WITH A WEAK FROPA FRIDAY AFTN. SUNDAY INTO
MONDAY...A BROAD UPPER RIDGE OVER THE WEST COAST WILL PRODUCE AND
DRY AND SUBSIDENT NORTHWESTERLY FLOW ALOFT OVER CO.

AVIATION...WINDS TRENDING MORE NORTHWEST...WITH SOME DECREASE IN
SPEEDS. GUSTS STILL AROUND 30 KTS AT KBJC WITH A FEW GUSTS AROUND
20 KTS AT KDEN. GRADIENT EXPECTED TO WEAKEN THIS EVENING...
SHOULD SEE WINDS DECREASE AS A RESULT. A WEAK SURGE WILL BE MOVING
IN FROM THE NORTH AROUND MIDNIGHT. WINDS MAY GO NORTHEAST AROUND
03Z AND EAST TO SOUTHEAST BY 06Z AS SHOWN BY THE LATEST MODELS.
BUT WILL BE FIGHTING THE WEAKENING WEST TO EAST GRADIENT. CURRENT
THINKING IS THAT THE SOUTHERLY DRAINAGE FLOW WILL PREVAIL BY 03Z
AND CONTINUE THROUGH THE MORNING HOURS WEDNESDAY. BY 18Z WINDS TO
BECOME SHIFT TO THE SOUTHEAST...SPEEDS TO STAY BELOW 8 KTS. VFR TO
CONTINUE WITH UNLIMITED CEILINGS. LOWER AIRMASS WILL BE DRY SO NOT
EXPECTING LOW CLOUDS OR FOG OVERNIGHT.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 10 PM MST THIS EVENING FOR COZ035-036-
039.

&&

$$

SHORT TERM...ENTREKIN
LONG TERM....COOPER
AVIATION...ENTREKIN