000
FXUS65 KBOU 061019
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
319 AM MST FRI DEC 6 2013

.SHORT TERM...SEVERAL AREAS OVER THE PLAINS CONTINUE TO SEE LIGHT
FLURRIES EARLY THIS MORNING WITH LITTLE TO PUSH IT OUT. WILL
CONTINUE THIS THROUGH MID MORNING THEN EXPECT CLEARING.

AN UPPER TROUGH OVERHEAD WILL MOVE EAST WITH SLIGHT RIDGING TO
MOVE IN. 700 MB TEMPERATURES WILL CHANGE LITTLE FROM YESTERDAY
DURING THE DAY HOWEVER EXPECT MORE CLOUD COVER...SO EXPECT SIMILAR OR
SLIGHTLY COOLER MAXIMUM TEMPERATURES. ONLY A FEW LIGHT SNOW
SHOWERS ARE EXPECTED OVER THE MOUNTAINS TODAY...MAINLY NORTH OF
I70...WITH LESS THAN AN INCH OF ACCUMULATION.

TONIGHT...SURFACE PRESSURE GRADIENTS WILL BE INCREASING AS STRONG
HIGH PRESSURE MOVES SOUTH FROM MONTANA AND A SURFACE LOW MOVES
INTO THE GREAT BASIN WITH THE NEXT APPROACHING SYSTEM. SOUTHERLY
SURFACE WINDS WILL INCREASE OVER THE EASTERN PLAINS TONIGHT WHICH
MAY COMBINE WITH TEMPERATURES TO BRING DANGEROUS WIND CHILLS.
CONFIDENCE IS LOW HOWEVER WITH MODEL TRENDS NOW OF LOWER WINDS AND
UNCERTAIN HOW COLD IT WILL GET WITH INCREASING HIGH CLOUDS TONIGHT
AHEAD OF THE NEXT SYSTEM. MAY NEED A WIND CHILL ADVISORY ISSUED
LATER.

.LONG TERM...MAIN CONCERNS WILL BE VERY COLD TEMPERATURES THROUGH
THE WEEKEND AND THEN A GRADUAL EROSION OF THE ARCTIC COLD NEXT
WEEK...AS WELL AS CHANCE OF SNOW WITH INCOMING SYSTEM.

SATURDAY WILL START OFF QUITE COLD AGAIN WITH POSSIBLE WIND CHILL
HIGHLIGHTS ADDRESSED ABOVE ON THE EASTERN PLAINS. OTHERWISE...
THERE SHOULD BE A SLIGHT MODERATION OF TEMPERATURES...ALBEIT STILL
VERY COLD...WITH WARM ADVECTION OCCURRING AHEAD OF NEXT SHORT
WAVE DROPPING ACROSS THE GREAT BASIN. Q-G VERTICAL MOTIONS
INCREASE THROUGH THE DAY AHEAD OF THIS FEATURE...AND FAVORABLE JET
LOCATIONS SHOULD LEAD TO GOOD UPPER LEVEL DIVERGENCE. HOWEVER...AT
THE SAME TIME SYSTEM APPEARS A BIT MOISTURE STARVED AS THE DESERT
SOUTHWEST IS VERY DRY AT THE PRESENT TIME. IN ANY CASE...WE COULD
START OFF WITH A COUPLE WEAK CYCLONE/LOW LEVEL CONVERGENCE
FLURRIES ON THE PLAINS SIMILAR TO THIS MORNING...WITH SNOW
GRADUALLY DEVELOPING OVER THE MOUNTAINS AND PERHAPS SPREADING OFF
THE FRONT RANGE BY LATE IN THE AFTERNOON. THE BEST CHANCE OF SNOW
WOULD LIKELY HOLD OFF UNTIL SATURDAY NIGHT WHEN A LOBE OF MODERATE
Q-G VERTICAL MOTION IS EXPECTED TO MOVE NEARLY SQUARELY ACROSS THE
FORECAST AREA. HOWEVER...THERE IS CONSIDERABLE WESTERLY FLOW JUST
OFF THE DECK WHICH WILL LIKELY LIMIT PRECIP CHANCES ALONG THE
FRONT RANGE. AT THIS TIME THE BETTER SNOW CHANCES WILL BE IN THE
MOUNTAINS WHERE SNOW WILL BE LIKELY...AND ACROSS THE EASTERN
PLAINS WHERE DOWNSLOPE COMPONENT IS LESS PRONOUNCED. THE SAME
GENERAL PATTERN IS EXPECTED TO HOLD INTO SUNDAY MORNING BEFORE
DRYING AND SUBSIDENCE MOVE IN DURING THE AFTERNOON. TEMPERATURES
WILL REMAIN QUITE COLD THROUGH SUNDAY WITH EXPECTED REINFORCEMENT
OF ARCTIC AIR BEHIND THE SHORT WAVE SUNDAY AFTERNOON AND EVENING.
THERE SHOULD BE SOME MODERATION IN THE HIGH MOUNTAIN VALLEYS DUE
TO INCREASED CLOUD COVER AND MIXING.

BY MONDAY...ONLY SLIGHT MODERATION IS EXPECTED AS ARCTIC AIRMASS
MAY BEGIN TO LOOSEN ITS GRIP ON THE AREA. TUESDAY SHOULD FINALLY
FEATURE THE WARMER...ALTHOUGH STILL WELL BELOW NORMAL...
TEMPERATURES. THERE ARE SOME INDICATIONS THAT A BACKDOOR COLD
FRONT COULD CLIP THE PLAINS LATE TUESDAY INTO WEDNESDAY SLOWING
THE WARMING TREND. HOWEVER...BY THURSDAY MOST MEDIUM RANGE MODELS
ARE IN AGREEMENT OF NEAR TO ABOVE NORMAL TEMPERATURES RETURNING AT
THAT TIME. THE ONLY EXCEPTION TO THE WARMER WEATHER COULD VERY
WELL BE THE HIGH MOUNTAIN VALLEYS WHERE CLEARING SKIES AND FRESH
SNOW COVER WILL LIKELY ALLOW STRONG INVERSIONS TO REDEVELOP...SO
LOWERED MAX AND MIN TEMPS THERE.

THE MONDAY THROUGH THURSDAY TIME FRAME SHOULD FEATURE MAINLY DRY
CONDITIONS WITH MOST SHORT WAVES AND MOISTURE HOLDING NORTH OF
THE FORECAST AREA. STILL CANT TOTALLY RULE OUT A FEW OROGRAPHIC
SNOW SHOWERS IN THE NORTHERN MOUNTAINS MONDAY INTO TUESDAY GIVEN
WEST/NORTHWEST FLOW ALOFT.

&&

.AVIATION...PATCHY LOW CLOUDS AND LIGHT SNOW ARE EXPECTED TO
LINGER THROUGH MID MORNING. EXPECT CEILINGS OF 3000 FEET UNDER
THE CLOUDS AND LIGHT SNOW DECREASING VISIBILITY TO NEAR 2 MILES
DURING THIS TIME. A VERY WEAK DENVER CYCLONE HAS OCCURRED OVERNIGHT
HELPING KEEP THE CLOUDS AND SNOW IN. EXPECT SOME FORM OF THIS WEAK
CYCLONE ALL DAY PRODUCING SOUTHEAST WINDS AT KDEN...NORTHERLY AT
KBJC AND VERY LIGHT SOUTHERLY WINDS AT KAPA. RAISING AND
SCATTERING OF CEILINGS AFTER 15Z WITH VFR CONDITIONS EXPECTED.
LOWER CEILINGS THEN WILL MOVE IN FROM THE SOUTHEAST LATE TONIGHT
EARLY SATURDAY MORNING.

&&

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

$$

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