Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/20/14
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
400 AM MST THU DEC 18 2014
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 400 AM MST THU DEC 18 2014
A VERY WEAK LOW AMPLITUDE UPPER TROUGH WILL BE MOVING OVER THE
STATE TODAY WITH WEAK WESTERLY WINDS ALOFT AND VERY LITTLE FORCING
FOR ASCENT. MOISTURE LEVELS OVER THE MOUNTAINS WILL BE SUFFICIENT
FOR THE WEAK WEST WINDS TO PRODUCE PERIODS OF LIGHT OROGRAPHIC
SNOWFALL. DO NOT EXPECT TO SEE ANY ACCUMULATIONS GREATER THAN ONE
OF TWO INCHES. AREAS OF FOR AND LOW CLOUDS HAVE BEEN DRIFITNG OVER
THE NORTHEAST CORNER OF THE STATE EARLIER THIS MORNING...BUT
VISIBILITIES AT METAR STATIONS HAVE RECENTLY BEEN IMPROVING. WILL
HANG ON TO THE MENTION OF AREAS OF FOG THROUGH ABOUT MID MORNING.
WILL ALSO HANG ON TO PARTLY AND MOSTLY CLOUDY SKY COVER ACROSS
THE FORECAST AREA DUE TO THE MID-LEVEL MOISTURE THAT WILL BE
ADVECTING ACROSS THE REGION. TEMPERATURES SHOULD BE AROUND NORMAL
FOR THIS TIME OF YEAR IN THE ABSENCE OF ANY STRONG DOWNSLOPING
WARMING OR STRONG SUNSHINE. THE UPPER TROUGH WILL REMAIN OVER THE
FORECAST AREA THROUGH MIDNIGHT TONIGHT...SO THERE IS LITTLE NEED
TO REDUCE POPS OVER THE MOUNTAINS UNTIL THEN.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 400 AM MST THU DEC 18 2014
A WK UPPER LEVEL TROUGH WILL MOVE EAST OF THE AREA EARLY ON FRI AS A
FLAT UPPER LVL RIDGE DEVELOPS BY AFTN. OVERALL CROSS-SECTIONS ONLY
SHOW SOME MOISTURE NR MTN TOP SO WILL ONLY MENTION A SLIGHT CHC OF
SHSN OVER THE HIGHER PEAKS WITH DRY CONDITIONS ELSEWHERE. 850-700
MB TEMPS DO NOT CHANGE MUCH ON FRI SO WILL KEEP HIGHS IN THE LOWER
TO MID 40S OVER THE URBAN CORRIDOR BUT KEEP HIGHS IN THE 30S OVER
THE PLAINS WHERE SNOW COVER WILL STILL EXIST.
ON SAT ANOTHER WK UPPER LEVEL TROUGH MAY AFFECT THE AREA BRINGING A
CHC OF -SHSN TO THE MTNS WITH DRY CONDITIONS ELSEWHERE. 850-700 MB
TEMPS RISE A FEW DEGREES SO WILL HAVE HIGHS IN THE LOWER TO MID 40S
OVER NERN CO ALTHOUGH READINGS AROUND DENVER COULD REACH THE UPPER
40S.
BY SUN THE FLOW ALOFT WILL BECOME MORE NWLY AND INTENSIFY. MOISTURE
WILL GRADUALLY INCREASE IN THE MTNS THRU THE DAY SO SHOULD A BETTER
CHC OF SNOW ESPECIALLY BY AFTN. OVER NERN CO IT WILL REMAIN DRY
ALTHOUGH MAY SEE AN INCREASE IN MID AND HIGH LVL CLOUD COVER. 850-
700 MB TEMPS RISE ANOTHER 3 DEGREES OR SO WHICH MAY ALLOW FOR HIGHS
TO REACH THE LOWER 50S AROUND DENVER WITH 40S ACROSS THE PLAINS.
FOR SUN NIGHT INTO MON STG MOIST NWLY FLOW ALOFT WILL BE OVER THE
AREA WITH INCREASING INSTABILITY ACROSS THE AREA AS LAPSE RATES RISE
INTO THE 7-8 C/KM RANGE. WITH FAVORABLE OROGRAPHICS IN PLACE ALONG
WITH PLACEMENT OF UPPER LVL JET MAY SEE A HEAVY SNOW EVENT IN THE
MTNS AND PORTIONS OF HIGHER VALLEYS. OVER NERN CO APPEARS A BORA
TYPE FNT WILL MOVE ACROSS THE AREA LATE SUN NIGHT INTO MON MORNING.
DESPITE NWLY FLOW IN THE LOWER LEVELS PLACEMENT OF UPPER LEVEL JET
AND DECENT LAPSE RATES COULD LEAD TO SOME SHOWER ACTIVITY OVER NERN
CO. THE ECMWF HAS THE BEST CHC OF PCPN LATE SUN NIGHT INTO MON
MORNING WHILE THE GFS HAS THE BEST CHC MON AFTN INTO MON EVENING.
IN ADDITION THE GFS ATTEMPTS TO TURN THE WINDS MORE NNE MON AFTN
INTO MON EVENING WHICH WOULD INCREASE THE CHC OF PCPN FM DENVER
SOUTH ACROSS THE PALMER DIVIDE. MEANWHILE TEMP PROFILES FM THE
ECMWF WOULD FAVOR PCPN MOSTLY AS SNOW WHILE THE GFS KEEPS READINGS
WARMER WITH PCPN FALLING AS RAIN MON AFTN BEFORE CHANGING TO SNOW
MON EVENING. THIS FAR OUT HARD TO SAY HOW THINGS WILL EVOLVE SO
WILL KEEP POPS IN THE 20-30 PERCENT RANGE FOR NOW SINCE TIMING OF
PCPN IS STILL UNCERTAIN.
FOR TUE STG NWLY FLOW ALOFT WILL CONTINUE OVER THE AREA. CROSS-
SECTIONS SHOW SOME DECREASE IN MOISTURE DEPTH IN THE MTNS HOWEVER
LAPSE RATES REMAIN IN THE 7-8 C/KM RANGE. THUS WILL STILL SEE
PERIODS OF OROGRAPHIC DRIVEN SNOW. OVER NERN CO THE ECMWF SHOWS A
WK SURGE OF COOLER AIR MON NIGHT INTO TUE MORNING ALONG THE FRONT
RANGE WHICH COMBINES WITH DECENT LAPSE RATES TO PRODUCE SNOW ALONG
THE URBAN CORRIDOR WHICH IS ENHANCED BY PLACEMENT OF UPPER LEVEL
JET. THE GFS SORT OF SHOWS A SIMILAR SET UP BUT DOES NOT HAVE AS
MUCH PCPN. FOR NOW WILL JUST MENTION A SLIGHT CHC OF SNOW FOR THE
LATE MON NIGHT INTO TUE MORNING TIME PERIOD. AS FOR HIGHS WILL KEEP
HIGHS IN THE 35 TO 40 DEGREE RANGE OVER THE PLAINS.
FOR TUE NIGHT INTO WED THE FLOW ALOFT WILL CONTINUE MAINLY NWLY.
CROSS-SECTIONS SHOW MOISTURE DEPTH INCREASING IN THE MTNS WITH
FAVORABLE LAPSE RATES SO SHOULD CONTINUE TO SEE PERIODS OF
OROGRAPHIC SNOW WHICH MAY BE ENHANCED BY PLACEMENT OF UPPER LEVEL
JET. OVER NERN CO BOTH THE ECMWF AND GFS SHOW ANOTHER SURE OF
COOLER AIR MOVING INTO THE AREA TUE NIGHT INTO EARLY WED. ONCE
AGAIN WITH PLACEMENT OF UPPER LEVEL JET AND FAVORABLE LAPSE RATES
COULD SEE ANOTHER CHC OF SNOW DURING THIS TIME PERIOD. THUS WILL
INCLUDE SOME LOW POPS. HIGHS ON WED SHOULD STAY IN THE 30S OVER
NERN CO BASED ON LATEST 850-700 MB TEMPS.
LOOKING AHEAD TOWARDS CHRISTMAS EVE INTO CHRISTMAS DAY LATEST ECMWF
AND GFS INDICATE A GOOD CHC OF SNOW AS AN UPPER LEVEL TROUGH MOVES
SE INTO THE RGN ALONG WITH ANOTHER SHOT OF COLDER AIR. OF COURSE
THIS IS STILL A WEEK AWAY SO WE SHALL SEE HOW THINGS PLAY OUT.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 400 AM MST THU DEC 18 2014
SURFACE PRESSURE GRADIENTS WILL BE QUITE WEAK ACROSS NORTHEAST
COLORADO THROUGH TODAY AND TONIGHT...SO LIGHT WINDS ARE EXPECTED
TO CONTINUE. THE RAP INDICATES SOME LIGHT EASTERLY WINDS IN THE
AFTERNOON AND EVENING...BUT SPEEDS SHOULD REMAIN IN THE 5-10 KNOT
RANGE. NOTHING MORE THAN MID AND HIGH LEVEL CLOUDS ARE EXPECTED
THROUGH THE NEXT 24 HOURS AS THE WEAK UPPER LEVEL DISTURBANCE
MEANDERS OVERHEAD. IMPACTS TO AVIATION OPERATIONS SHOULD BE
MINIMAL.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DANKERS
LONG TERM...RPK
AVIATION...DANKERS
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
924 PM EST FRI DEC 19 2014
.UPDATE...
EVENING SURFACE ANALYSIS DEPICTS LOW PRESSURE (1013 MILLIBARS)
POSITIONED ALONG THE LOUISIANA COAST....WITH A DEVELOPING WARM
FRONT POSITIONED EAST OF THIS FEATURE ALONG THE NORTHERN GULF
COAST. HIGH PRESSURE (1026 MILLIBARS) WAS CENTERED OVER THE OHIO
VALLEY AND GREAT LAKES STATES. ALOFT...A SHORTWAVE TROUGH
POSITIONED OVER THE ARKLATEX WAS PROGRESSING EAST-NORTHEASTWARD
TOWARDS THE TENNESSEE VALLEY. THIS FEATURE WAS INCREASING
ISENTROPIC ASCENT OVER WESTERN PORTIONS OF OUR REGION...WITH A
SHIELD OF MOSTLY LIGHT RAINFALL PROGRESSING EASTWARD INTO THE
WESTERN SUWANNEE VALLEY AND TOWARDS THE OCMULGEE RIVER. THE
EVENING SOUNDING AT JACKSONVILLE DISPLAYED A VERY DRY LAYER
BETWEEN 825-700 MILLIBARS (6000-10000 FT)...AND THUS IT WILL TAKE
TIME TO MOISTEN THE LOW LEVELS AS THE RAIN SHIELD MOVES INTO OUR
REGION. WE CONFINED POPS TO LOCATIONS MOSTLY ALONG AND NORTH OF
INTERSTATE 10...WITH A PERIOD OF LIKELY POPS EXPECTED AFTER
MIDNIGHT FOR LOCATIONS ALONG THE OCMULGEE/ALTAMAHA RIVERS. DUE TO
THE PERSISTENT DRY AIR MASS...RAINFALL AMOUNTS THROUGH THE MORNING
HOURS WILL BE LIGHT. THE HI-RES HRRR MODEL DEPICTS FOG FORMATION
OVER PORTIONS OF NORTHEAST FL OVERNIGHT...BUT WE ARE DISCOUNTING
THIS DUE TO THICK MID AND HIGH ALTITUDE CLOUD COVER THAT HAS
OVERSPREAD OUR REGION. THESE CLOUDS WILL KEEP LOWS IN THE MID 40S
INLAND...RANGING TO THE LOWER 50S AT THE COAST. SCATTERED RAIN
CHANCES WILL CONTINUE FOR OUR NORTHERN COUNTIES THROUGH THE
MORNING HOURS ON SATURDAY...WITH DRY CONDITIONS EXPECTED
THROUGHOUT NORTHEAST AND NORTH CENTRAL FL DESPITE EXTENSIVE MID
AND HIGH CLOUD COVER.
&&
.AVIATION...
VFR CONDITIONS TO PREVAIL THROUGH THE NEXT 24 HOURS. THICKENING
MID CLOUD DECK OVERNIGHT WILL INHIBIT FOG DEVELOPMENT. WILL
MAINTAIN VCSH AT SSI FOR POSSIBILITY OF A FEW LIGHT SPRINKLES
MOVING THROUGH THAT AREA LATE TONIGHT.
&&
.MARINE...
BENIGN CONDITIONS TO CONTINUE OVERNIGHT WITH WINDS LESS THAN 10
KNOTS AND SEAS AVERAGING AROUND 2 FEET OR LESS. NO CHANGES NEEDED
FOR THE ROUTINE EVENING FORECAST ISSUANCE.
RIP CURRENTS: POSSIBLE MODERATE RISK EXPECTED OVER THE WEEKEND IN
STRENGTHENING ONSHORE FLOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 45 61 48 61 / 50 40 20 40
SSI 51 62 51 63 / 30 20 20 30
JAX 48 68 53 68 / 20 10 10 30
SGJ 51 68 57 69 / 10 10 10 30
GNV 46 71 55 71 / 10 0 10 50
OCF 46 72 56 73 / 0 0 10 40
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
NELSON/SHULER/
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
410 AM EST THU DEC 18 2014
.SYNOPSIS...STRONG MID AND UPPER LEVEL TROUGH IS LOCATED OVER THE
WRN U.S. WITH DOWNSTREAM UPPER LEVEL JET LOCATED ACROSS TX TO THE TN
VALLEY. WEAK MID TO UPPER LEVEL RIDGE ACROSS OUR FORECAST AREA WITH
UPPER LEVEL DISTURBANCES AND JET HELPING TO SPREADING AN OCNL
BROKEN-OVERCAST CIRRUS CLOUDS OVERHEAD. SFC HIGH PRES CENTRAL PLAINS
TO CENTRAL GULF COAST WITH LIGHT W TO NW FLOW OVER OUR AREA. TEMPS
ARE IN THE 40S MOST LOCATIONS WITH A FEW UPPER 30S OVER INLAND SE
GA. PATCHY FOG NOTED OVER THE SUWANNEE VALLEY PER SFC OBS AS PASSING
HIGH CLOUDS ARE MASKING ANY LOW CLOUD OR FOG DETECTION. FOG IS ALSO
INDICATED IN LATEST HRRR AND NARRE FCST GUIDANCE FROM AROUND LIVE
OAK TO OCALA. WILL CONTINUE MENTION OF FOG INTO THE EARLY MORNING
FCST...AND VSBY MAY BE BELOW 1 MI AT TIMES.
.SHORT TERM...FOR TODAY...ONE MID AND UPPER LEVEL SHORTWAVE TROUGH
WILL SHIFT EWD FROM CENTRAL PLAINS TO THE OHIO VALLEY WHILE
DE-AMPLIFYING. WE ANTICIPATE HIGH CLOUDS TO CONTINUE TO AFFECT THE
REGION THROUGH FIRST OF THE HALF OF THE DAY...WITH THINNING OF
CLOUDS IN THE AFTN FROM THE NW TO SE. SFC HIGH PRES NW OF THE AREA
WILL ALLOW FOR PREVAILING LIGHT NW TO N WINDS. MAX TEMPS TODAY
EXPECTED TO BE IN THE 60S AREA-WIDE BUT PERHAPS A TOUCH BELOW
CLIMATOLOGY. TONIGHT...A MORE SIGNIFICANT MID AND UPPER LEVEL SHORTWAVE
LOCATED ACROSS THE FOUR CORNERS WILL TRANSLATE TO LOWER CONUS
GENERATING SFC CYCLOGENESIS OVER THE WRN GULF. THIS DIGGING
SHORTWAVE TROUGH WILL ENHANCE MOISTURE OVER THE AREA LATER TONIGHT
THROUGH FRIDAY WITH PWATS INCREASING FROM ABOUT HALF AN INCH TO 3/4
OF AN INCH. GUIDANCE TEMPS ARE IN GOOD AGREEMENT WITH SIMILAR
READINGS TO THIS MORNING...MAINLY IN UPPER 30S TO LOWER 40S. COOLEST
READINGS WELL INTERIOR LOCATIONS. LOCAL TOOLS AND MODEL SOUNDINGS
DON`T SUPPORT MENTION OF FOG ATTM.
FRIDAY...STRONG MID AND UPPER SHORTWAVE TROUGH WILL MOVE INTO THE MS
RIVER VALLEY AND ASSOCD SFC LOW PRES WILL MOVE TOWARD THE LA COAST.
SFC HIGH PRES DUE N OF THE AREA WILL OOZE EWD ALLOWING WINDS TO
SLOWLY TURN TO THE NELY BUT LIGHT WIND SPEEDS. THE TAIL END OF A
WEAK FRONT WILL MOVE THROUGH PARTS OF SE GA BUT LITTLE SENSIBLE WX
NOTED BESIDES THE WIND SHIFT WITH SLIGHT BUMP IN SPEEDS AND
INCREASED DEWPOINTS. EXPECT PARTLY CLOUDY SKIES INCREASING DURING
THE DAY AS ISENTROPIC LIFT INCREASES FROM THE W AND NW. A SLIGHT
CHANCE AROUND 20 PRCT IS INDICATED OVER OUR FAR NW ZONES AS LIFT
INCREASES IN ASSOCD WITH MID LEVEL SHORTWAVE ENERGY. MAX TEMPS AGAIN
NEAR CLIMATOLOGY IN THE 60S MOST LOCATIONS.
FRIDAY NIGHT THROUGH SATURDAY NIGHT...THE EXTENDED DRY WEATHER
PERIOD COMES TO A CLOSE AS SFC LOW CONTINUES TO DEVELOP OVER THE
NORTHERN GULF OF MEX AND TRAVEL EASTWARD TOWARDS THE FL PENINSULA.
LOW LEVEL MOISTURE WILL PUSH INTO THE AREA AHEAD OF THIS SYSTEM
INCREASING PRECIP CHANCES FRIDAY NIGHT INTO SATURDAY WITH THE
HIGHEST CHANCES...AROUND 40 TO 50 PERCENT...DURING THE AFTERNOON
SATURDAY ACROSS SE GA CLOSEST TO THE MID LEVEL IMPULSE PASSING TO
THE NORTH OVER CENTRAL GA. LOWER PRECIP CHANCES EXPECTED OVER NE
FL WITH LESS UPPER LEVEL SUPPORT. MINIMUM TEMPS WILL MODERATE
FRIDAY AND SATURDAY NIGHTS INTO THE UPPER 40S AND 50S WITH
INCREASED CLOUD COVER. MAX TEMPS SATURDAY WILL REMAIN NEAR NORMAL
ACROSS SE GA IN THE LOW/MID 60S WITH NE FL WARMING INTO THE UPPER
60S TO LOW 70S WITH A FEW MORE BREAKS IN THE CLOUDS.
.LONG TERM...
SUNDAY THROUGH WEDNESDAY....LONG TERM MODELS IN DECENT AGREEMENT
ON THE TIMING OF FOLLOWING SHORTWAVE AS IT RUNS UP OVER A FRONTAL
BOUNDARY WHICH HAS BECOME MOSTLY STATIONARY OVER THE AREA SUNDAY INTO
MONDAY. RAIN CHANCES WILL INCREASE FROM SUNDAY NIGHT INTO MONDAY
WITH LIKELY CHANCES ON MONDAY AS DEEP SOUTHWESTERLY FLOW LIFTS
RELATIVELY WARM AIRMASS OVER COOLER AIR. COVERAGE OF PRECIP SHOULD
DECREASE MONDAY NIGHT AS SFC LOW MOVES OFF TO THE NORTHEAST UP THE
ATLANTIC COAST BUT WILL INCREASE ONCE AGAIN ON TUESDAY AS UPPER
TROUGH DEEPENS OVER THE GREAT LAKES REGION WITH SFC LOW AND
ASSOCIATED COLD FRONT PULLING MOISTURE UP OVER THE AREA AS THE
BOUNDARY APPROACHES THE REGION. THUNDERSTORMS WILL BE POSSIBLE TUESDAY
INTO EARLY WEDNESDAY WITH UPPER TROUGH CONTINUING TO DEEPEN AND
BECOME NEGATIVELY TILTED AND SFC COLD FRONT PASSES THROUGH. CURRENT WPC
QPF FORECASTS SHOWING RAINFALL TOTALS SUNDAY THROUGH WEDNESDAY UP
TO 3 INCHES WITH HIGH LEVELS OF AVAILABLE MOISTURE AND PERSISTENT FORCING
MECHANISMS. CONDITIONS WILL BEGIN TO IMPROVE ON WEDNESDAY AS COLD
FRONT PUSHES THROUGH AND DRIER AIRMASS FILTERS IN BEHIND. MILD
TEMPERATURES EXPECTED EACH AFTERNOON SUNDAY THROUGH TUESDAY IN THE
60S AND LOW 70S BEFORE COLD AIR ADVECTION INITIATES ON WEDNESDAY
AND TEMPS BEGIN TO DECREASE. MIN TEMPS WILL FOLLOW SUIT IN THE
UPPER 40S AND 50S ACROSS MUCH OF THE AREA EACH NIGHT UNTIL
WEDNESDAY NIGHT WHEN COLDER TEMPS ARE EXPECTED.
&&
.AVIATION...VFR BUT BRIEF VSBY REDUCTIONS POSSIBLE AT VQQ.
OCNL CIGS AOA 20 KFT THROUGH 06Z FRI. LIGHT NW TO W WINDS...THOUGH A
WEAK SEA BREEZE WILL BE POSSIBLE AT SSI AFTER 20Z.
&&
.MARINE...BENIGN CONDITIONS CONTINUE THROUGH FRIDAY WITH FAIRLY
LIGHT NLY WINDS AND LOW SEA HEIGHTS. NELY FLOW LIGHT ON FRIDAY AND
SHIFTS TO MORE SLY ON SAT. A WEAK AREA OF LOW PRESSURE AND
ASSOCIATED COLD FRONT WILL MOVE EASTWARD AND STALL ACROSS THE WATERS
SUNDAY AND MONDAY MAKING FOR UNSETTLED WEATHER WITH A GOOD CHANCE OF
RAIN. ANOTHER STRONGER COLD FRONT WILL APPROACH FROM THE W BY
TUESDAY. STILL CAN`T TOTALLY DISCOUNT A CHANCE OF SEA FOG EARLY SAT
MORNING AND/OR SAT EVENING AS DEWPOINTS INCREASE AS FLOW TURNS TO NE
AND SE BUT POTENTIAL SEEMS TOO LOW TO INCLUDE ATTM.
RIP CURRENTS: LOW RISK EXPECTED THROUGH FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 63 38 64 49 / 0 0 10 30
SSI 61 44 62 52 / 0 0 10 20
JAX 64 41 66 51 / 0 0 10 10
SGJ 64 46 65 55 / 0 0 10 10
GNV 66 40 68 51 / 0 0 10 10
OCF 67 40 70 52 / 0 0 10 10
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
GUILLET/SHASHY/
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
909 PM CST Fri Dec 19 2014
.UPDATE...
ISSUED AT 905 PM CST FRI DEC 19 2014
The surface ridge axis is finally making some progress to the east
of Illinois, allowing winds west of I-55 to start a trend out of
the southeast. A weak shortwave passing across southern IL could
trigger some light snow showers or flurries southeast of I-70.
Radar returns toward Lawrenceville are mostly virga, with no snow
reaching the ground yet. Cloud heights are lowering with time
under that wave, so some flurries were added to the forecast for
the far southeast counties toward midnight.
The next area of concern is NW of the IL river, where low clouds
and fog may develop into some freezing drizzle toward sunrise. The
precip could fall as flurries, but a lack of ice crystals to feed
into the low cloud layer will limit the ability for snowflakes to
develop. Thus, the concern for FZDZ to occur. Any icing would
cause slippery travel conditions. Have added a mention of FZDZ
between 12z-15z Sat morn, but may need a mention even earlier
depending on speed of saturation and progression of shortwave from
Nebraska across Iowa/N MO.
Low temps will not drop off appreciably from current temps due to
increasing clouds. Updates this evening were to the weather and
sky grids to match expected trends.
&&
.SHORT TERM...(Tonight)
ISSUED AT 328 PM CST FRI DEC 19 2014
20z/2pm visible satellite imagery continues to show a large break in
the overcast extending from southeast Iowa across much of central
Illinois into Kentucky. With high pressure directly overhead and
only very light low-level winds, partly to mostly clear conditions
will persist through the evening hours. As the high begins to shift
eastward, a southerly return flow will gradually develop late
tonight into Saturday, allowing the low clouds currently across
Iowa/Missouri to spill back into the area. End result will be a
mostly clear start to the night, with overcast conditions expected
across the board by dawn Saturday. May also see some patchy fog
west of the I-55 corridor late tonight as low-level moisture
increases, but am not expecting any major restrictions to
visibility. Due to the initially mostly clear skies and light
winds, another cold night is expected with low temperatures
bottoming out in the lower to middle 20s.
&&
.LONG TERM...(Saturday through Friday)
ISSUED AT 328 PM CST FRI DEC 19 2014
A rather quiet weekend is on tap across central and southeast
Illinois, but weather activity will be on the upswing heading into
the Holiday work week.
Model agreement is good through the weekend with mostly neutral
upper-level flow and high pressure expected to be the dominant
player at the surface. A week wave, currently pushing east across
the central Plains, will cross the area early Saturday. However, the
forcing appears too weak, and moisture depth too shallow, to warrant
a mention of any precipitation.
A strong, slow moving system will impact the area from Monday into
Christmas Eve. We will remain on the warm side of the system through
Tuesday, with all precipitation initially expected to fall in the
form of rain. Temperatures ahead of the system will also average
nearly 10 degrees above normal for late December.
The colder air on the back side of the deepening storm system will
arrive for Tuesday night into Christmas Eve. This would support any
remaining precipitation changing over to snow. At this point, the
threat for significant snowfall on the back side of the system seems
low, but some light snow accumulation is likely. The model
agreement/run-to-run consistency is still a little shaky heading
into midweek, so future model trends will need to be monitored very
closely.
Another system is progged to arrive by late in the week, generally
Friday into Saturday. However, model consistency with this system is
poorer than the first, so confidence in the ultimate outcome is not
very high.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
ISSUED AT 544 PM CST FRI DEC 19 2014
Latest satellite imagery indicated a thin layer of high clouds has
streamed across much of central Illinois early this evening, with
no cloud ceiling showing up in the observations at any TAF site at
23z. Further west, MVFR/IFR ceilings blanket Iowa/Missouri, as
well as just to the NE across NE IL and Indiana. The HRRR is
indicating that mid level clouds 5-6k FT could advance over our
terminal sites later tonight. Eventually cloud heights are
projected to drop to MVFR Saturday morning, with light fog at 4SM
BR restrictions. Can not rule out some flurries or possibly even
patchy freezing drizzle around PIA and BMI tomorrow morning. For
now, did not include any mention of precip, but any FZDZ could
cause slippery travel surfaces. Will monitor upstream and
forecast soundings for possible FZDZ occurring toward sunrise and
through the morning.
With high pressure directly overhead this evening, low-level winds
continue to remain light. Expect no change in that area tonight. Southeast
winds will develop tomorrow morning as the high shifts off to the
east, which will drag MVFR clouds back into central IL the
remainder of the day, with spotty precip possible.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...Barnes
LONG TERM...Bak
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
601 PM CST FRI DEC 19 2014
.SHORT TERM...
237 PM CST
THROUGH SATURDAY...
UNFORTUNATELY IT LOOKS LIKE WE WILL REMAIN LOCKED IN THE CLOUDS YET
AGAIN TONIGHT...DESPITE A CLEARING WEDGE THAT EXTENDS FROM
WESTCENTRAL IL TO SOUTHERN IN. WITH HIGH PRESSURE OVERHEAD THE
ABILITY TO MIX TO THE SFC DRIER AIR HAS BEEN NONEXISTENT. WITH THE
CONSIDERABLE SOLAR SHIELDING THIS AFTERNOON...SFC TEMPS HAVE BEEN
UNABLE TO WARM MUCH. TEMPS IN MOST LOCATIONS HAVE REMAINED ARND 30
TO A FEW LOW 30S ACROSS THE FAR SOUTHERN CWFA. OVERNIGHT THE SFC
RIDGE WILL DRIFT EAST...ALLOWING LGT/VRB WINDS TO SLOWLY TURN
SOUTHWESTERLY BY DAYBREAK SAT. OVERNIGHT LOWS WILL GENERALLY BE IN
THE LOW/MID 20S...BUT IF CLOUDS REMAIN THICK ENOUGH IT IS PLAUSIBLE
THAT TEMPS COULD HOLD IN THE MID/UPR 20S. GUIDANCE HAS INDICATED A
WEAK LOBE OF VORTICITY ALONG THE NORTHERN STREAM PUSHING EAST ACROSS
THE NORTHERN PLAINS OVERNIGHT...ARRIVING ACROSS THE GREAT LAKES
REGION AROUND SAT MORNING. WHILE IT APPEARS MOST OF THE NEAR SFC
WILL REMAIN DRY...THERE IS SOME WEAK FORCING IN THE MID-LVLS ALONG
WITH MARGINAL SATURATION THAT SOME FLURRIES COULD OCCUR DURING THE
MORNING HOURS. WITH YET ANOTHER DAY OF CONTINUED CLOUDINESS SAT...IT
APPEARS LESS FAVORABLE FOR ANY BUMP TO THE TEMPS. SO HAVE NUDGED
TEMPS DOWN A DEGREE TO THE MID 30S ACROSS THE CWFA.
SATURDAY NIGHT WILL GENERALLY REMAIN DRY...HOWEVER THERE IS ANOTHER
WEAK VORT TRYING TO LIFT NORTHEAST ACROSS IOWA LATE SAT NGT/EARLY
SUN. WITH A SLIGHT WARM LAYER TRYING TO LIFT ACROSS THE
REGION...HOWEVER HAVE HELD ONTO MAINLY LGT SNOW. THERE IS SOME
CONCERN THAT TEMPS ALOFT COULD BE WARM ENOUGH TO FULLY MELT ANY
DENDRITES. THE OTHER CONCERN WORTH MENTIONING IS THAT THE LIFT/OMEGA
IS LACKING LATE SAT NGT...SO DROPLET SIZE COULD BE SMALL AND INSTEAD
OF ANY DENDRITES THERE COULD END UP BEING PATCHY FREEZING
DRIZZLE...MAINLY AFTER MIDNIGHT.
BEACHLER
&&
.LONG TERM...
237 PM CST
SUNDAY THROUGH SATURDAY...
500MB TROUGH WILL BEGIN TO DIG SOUTH ACROSS THE CENTRAL CONUS SUN
INTO MON...WITH A SERIES OF MID-LVL VORTS PROGGED TO SLIDE SOUTHEAST
ACROSS THE CANADIAN ROCKIES INTO THE NORTHERN PLAINS. THE MAIN FOCUS
WILL BE ON A STRONGER SHORTWAVE DEVELOPING SUN NGT/EARLY MON ACROSS
THE DAKOTAS...EXPECTED TO SLIDE SOUTHEAST ACROSS NORTHERN IL.
ALTHOUGH CONFIDENCE IN THE TIMING/PLACEMENT OF THIS PATH IS LOW
GIVEN CONTINUED CORRECTIONS BASED ON THE LATEST GUIDANCE CYCLES.
MOISTURE WILL BE ADVECTING NORTH OF THIS LOW MON...WITH PRECIP
ARRIVING MON MORNING LIKELY AS MAINLY RAIN OR PERHAPS A RAIN/SNOW
MIX ACROSS THE NORTHERN CWFA. THEN A QUICK PUSH OF MUCH WARMER AIR
WILL BRING TEMPS INTO THE UPR 30S/NEAR 40 MON AFTN AND SHOULD TURN
ANY PRECIP TO PLAIN RAIN. AS MON NGT PROGRESSES...THE LOW IS PROGGED
TO STEADILY DEEPEN AND LIFT NORTHEAST ACROSS NORTHERN IL EARLY TUE.
FROPA CURRENTLY PROGGED FOR TUE EVE...BRINGING COLDER AIR BACK INTO
THE FORECAST AREA AND TURNING RAIN OVER TO LGT SNOW.
MON NGT WITH THE WARM AIR STEADILY ADVECTING NORTH...TEMPS WILL
REMAIN IN THE MID/UPR 30S. TUE TEMPS COULD PUSH EVEN
WARMER...DEPENDING ON THE PLACEMENT/TIMING OF FROPA. CURRENT
INDICATIONS ARE THAT TEMPS WILL PUSH INTO THE LOW/MID 40S TUE AFTN.
CHRISTMAS EVE THROUGH CHRISTMAS DAY...
ENSEMBLES ALONG WITH OPERATIONAL SOLUTIONS HAVE BEEN TARGETING THE
SYSTEM BECOMING WRAPPED UP OVER THE GREAT LAKES REGION AND POSSIBLY
TRANSITIONING INTO ANOTHER LOW OVER SOUTHERN ONTARIO/SOUTHWEST
QUEBEC CHRISTMAS DAY. A TIGHT GRADIENT WILL REMAIN OVER THE REGION
BOTH CHRISTMAS EVE/CHRISTMAS DAY...WITH TEMPS RETURNING TO MORE
SEASONAL CONDITIONS IN THE LOW/MID 30S.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* MVFR CIGS.
ED F
//DISCUSSION...UPDATED 00Z...
PERSISTENT LOW CLOUDS AND LIGHT WINDS TO CONTINUE OVERNIGHT AND
INTO SATURDAY. LOW STRATO CUMULUS CLOUDS REMAIN TRAPPED UNDER
TEMPERATURE INVERSION AND LITTLE TO NO FORCING PRESENT OR EXPECTED
THROUGH MIDDAY SATURDAY TO HELP MOVE THEM OUT. MAY SEE A FEW
BREAKS SATURDAY AFTERNOON BUT LOW LEVEL MOISTURE REMAINS ABUNDANT
PER MODEL FORECAST SOUNDINGS HENCE EXPECT ANY HOLES TO BE
BRIEF/SMALL. WINDS BECOME LIGHT SOUTHERLY SATURDAY AS HIGH
PRESSURE RIDGE SLOWLY MOVES OFF TO OUR EAST.
ED F
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM TO HIGH FOR CIGS.
* HIGH FOR ALL OTHER FORECAST ELEMENTS.
ED F
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...MVFR CIGS. SOUTH WINDS.
MONDAY...MVFR CIGS. BRIEF PERIOD OF RAIN OR MIXED RAIN AND SNOW.
TUESDAY...MVFR CIGS. CHANCE OF RAIN.
WEDNESDAY...MVFR CIGS. BLUSTERY - GUSTY WEST WINDS. CHANCE OF
SNOW.
THURSDAY...VFR.
ED F
&&
.MARINE...
200 PM CST
HIGH PRESSURE IS OVER THE REGION AND IT WILL SLOWLY SHIFT EAST
THROUGH SUNDAY NIGHT. LIGHT WINDS BECOME SOUTHWEST OVERNIGHT. THE
NEXT LOW MOVES OVER THE DAKOTAS SUNDAY NIGHT WITH SOUTH WINDS
INCREASING TO 30 KT. MODELS DISAGREE WITH EXACT PATH OF THIS LOW.
ONE HAS THE LOW DEEPENING OVER LAKE SUPERIOR WEDNESDAY WHILE ANOTHER
HAS THE LOW DEEPENING OVER LAKE ERIE. SOUTHEAST WINDS AROUND 25 KT
ARE EXPECTED THROUGH MONDAY NIGHT AHEAD OF THE LOW...THEN WINDS
BECOME WEST BEHIND IT. FOR SPEEDS WENT MIDDLE OF THE ROAD GIVEN THE
VARIABILITY. COULD DEFINITELY SEE HIGHER GUSTS IF THE LOW DEEPENS
CLOSER TO THE LAKE.
MODELS AGREE ON VERY STRONG WINDS BEHIND THE LOW WEDNESDAY NIGHT
THROUGH THURSDAY. HAVE HIGH END GALES IN THE FORECAST AND SOME
GUIDANCE MEMBERS SUGGEST LOW END STORM FORCE GUSTS MAY BE POSSIBLE.
DO NOT HAVE THE CONFIDENCE TO GO THAT HIGH JUST YET...BUT HAVE HIGH
CONFIDENCE IN AT LEAST GALES. THE LOW SHIFTS NORTHEAST WITH WINDS
DIMINISHING THURSDAY NIGHT. THE NEXT LOW HOWEVER MOVES OVER THE
SOUTHERN PLAINS THURSDAY EVENING.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
544 PM CST Fri Dec 19 2014
.SHORT TERM...(Tonight)
ISSUED AT 328 PM CST FRI DEC 19 2014
20z/2pm visible satellite imagery continues to show a large break in
the overcast extending from southeast Iowa across much of central
Illinois into Kentucky. With high pressure directly overhead and
only very light low-level winds, partly to mostly clear conditions
will persist through the evening hours. As the high begins to shift
eastward, a southerly return flow will gradually develop late
tonight into Saturday, allowing the low clouds currently across
Iowa/Missouri to spill back into the area. End result will be a
mostly clear start to the night, with overcast conditions expected
across the board by dawn Saturday. May also see some patchy fog
west of the I-55 corridor late tonight as low-level moisture
increases, but am not expecting any major restrictions to
visibility. Due to the initially mostly clear skies and light
winds, another cold night is expected with low temperatures
bottoming out in the lower to middle 20s.
&&
.LONG TERM...(Saturday through Friday)
ISSUED AT 328 PM CST FRI DEC 19 2014
A rather quiet weekend is on tap across central and southeast
Illinois, but weather activity will be on the upswing heading into
the Holiday work week.
Model agreement is good through the weekend with mostly neutral
upper-level flow and high pressure expected to be the dominant
player at the surface. A week wave, currently pushing east across
the central Plains, will cross the area early Saturday. However, the
forcing appears too weak, and moisture depth too shallow, to warrant
a mention of any precipitation.
A strong, slow moving system will impact the area from Monday into
Christmas Eve. We will remain on the warm side of the system through
Tuesday, with all precipitation initially expected to fall in the
form of rain. Temperatures ahead of the system will also average
nearly 10 degrees above normal for late December.
The colder air on the back side of the deepening storm system will
arrive for Tuesday night into Christmas Eve. This would support any
remaining precipitation changing over to snow. At this point, the
threat for significant snowfall on the back side of the system seems
low, but some light snow accumulation is likely. The model
agreement/run-to-run consistency is still a little shaky heading
into midweek, so future model trends will need to be monitored very
closely.
Another system is progged to arrive by late in the week, generally
Friday into Saturday. However, model consistency with this system is
poorer than the first, so confidence in the ultimate outcome is not
very high.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
ISSUED AT 544 PM CST FRI DEC 19 2014
Latest satellite imagery indicated a thin layer of high clouds has
streamed across much of central Illinois early this evening, with
no cloud ceiling showing up in the observations at any TAF site at
23z. Further west, MVFR/IFR ceilings blanket Iowa/Missouri, as
well as just to the NE across NE IL and Indiana. The HRRR is
indicating that mid level clouds 5-6k FT could advance over our
terminal sites later tonight. Eventually cloud heights are
projected to drop to MVFR Saturday morning, with light fog at 4SM
BR restrictions. Can not rule out some flurries or possibly even
patchy freezing drizzle around PIA and BMI tomorrow morning. For
now, did not include any mention of precip, but any FZDZ could
cause slippery travel surfaces. Will monitor upstream and
forecast soundings for possible FZDZ occurring toward sunrise and
through the morning.
With high pressure directly overhead this evening, low-level winds
continue to remain light. Expect no change in that area tonight. Southeast
winds will develop tomorrow morning as the high shifts off to the
east, which will drag MVFR clouds back into central IL the
remainder of the day, with spotty precip possible.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Bak
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1205 AM CST THU DEC 18 2014
.SHORT TERM...
230 PM CST
THROUGH FRIDAY...
RELATIVELY BENIGN WEATHER ON TAP IN THE NEAR TERM UNDER THE
INFLUENCE OF HIGH PRESSURE WHICH WILL REMAIN OVER THE REGION INTO
THE WEEKEND. SURFACE RIDGE EXTENDS FROM MANITOBA INTO THE LOWER
MISSISSIPPI VALLEY THIS AFTERNOON WHILE ALOFT A SHEARED VORT MAX IS
DIGGING SOUTHEAST ACROSS FAR NORTHERN ILLINOIS. SOUNDINGS INDICATE
STEEP LOW LEVEL LAPSE RATES UP TO AROUND 900MB THIS AFTERNOON AND
RADAR IMAGERY DOES SHOW SIGNS OF SOME CONVECTIVE ROLLS WITH VERY
WEAK WIND PARALLEL RETURNS. WITH THESE INGREDIENTS IN PLACE...A FEW
FLURRIES HAVE BEEN NOTED ACROSS THE AREA...BUT NOTHING OF
CONSEQUENCE. ANY FLURRIES SHOULD TAPER BY MID-LATE AFTERNOON AS
INVERSION HEIGHTS BEGIN TO COME DOWN IN RESPONSE TO MODERATE TO
STRONG MID LEVEL HEIGHT RISES BEHIND DEPARTING SHORTWAVE. STRATUS
DECK REMAINS IN PLACE TODAY BUT HAS BEGUN TO THIN AND ERODE NEAR
THE WESTERN COUNTIES. ANY PEAKS OF SUNSHINE TODAY THOUGH ARE
EXPECTED TO BE BRIEF AS MID LEVEL CLOUD COVER INCREASES FROM THE
NORTH AS A WEAK TROUGH EMBEDDED ON THE EASTERN PERIPHERY OF THE
HIGH SAGS SOUTH ACROSS LAKE MICHIGAN...AND FROM THE SOUTHWEST AS
ANOTHER SHORTWAVE TROUGH CURRENTLY LIFTING ACROSS THE PANHANDLES
OF TX/OK PUSHES ACROSS CENTRAL ILLINOIS MIDDAY THURSDAY. PRECIP
WITH THIS SYSTEM IS EXPECTED TO STAY SOUTH OF THE CWA...TAPERING
AS IT OVERRIDES THE SURFACE RIDGE. CLOUD COVER MAY CONTINUE TO
REMAIN LOCKED IN UNDER THE INVERSION FRIDAY...BUT OTHERWISE EXPECT
VERY LIGHT WINDS AND DRY CONDITIONS ON SQUARELY UNDER THE SURFACE
HIGH.
DEUBELBEISS
&&
.LONG TERM...
230 PM CST
FRIDAY NIGHT THROUGH THURSDAY...
HIGH PRESSURE WILL CONTINUE TO SLOWLY SHIFT EAST ACROSS THE REGION
OVER THE WEEKEND WITH RETURN FLOW BRINGING WARMER TEMPERATURES
ESPECIALLY BY SUNDAY. MEANWHILE...THE PATTERN IS PROGGED TO BEGIN
AMPLIFYING BY LATE IN THE WEEKEND AS LONGWAVE TROUGH DEEPENS ACROSS
THE MID SECTION OF THE COUNTRY DOWNSTREAM OF A BUILDING RIDGE ALONG
THE WEST COAST. THE JET STREAM WILL DIVE TOWARDS THE GULF STATES BY
TUESDAY WITH SURFACE LOW DEEPENING IN RESPONSE EARLY NEXT WEEK.
THERE REMAIN SIGNIFICANT DIFFERENCES AS WELL AS RUN-TO-RUN
VARIABILITY IN THE TIMING AND TRACK OF THE LOW AS IT LIFTS ACROSS
THE MIDWEST MIDWEEK...WITH COMPLICATIONS AS THE MODELS DEAL WITH
PHASING THE SOUTHERN LOW WITH A CLIPPER LIKE SYSTEM. WILL
CERTAINLY HAVE TO KEEP AN EYE ON THE POTENTIAL FOR ACCUMULATING
SNOW TUESDAY INTO WEDNESDAY OVER THE NEXT SEVERAL DAYS AS MODELS
HOPEFULLY BEGIN TO HONE IN ON A SOLUTION. A RETURN TO BELOW NORMAL
CONDITIONS SEEMS LIKELY FOR THE LATTER HALF OF THE WEEK.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* MVFR CIGS THIS MORNING. CMS
//DISCUSSION...UPDATED 06Z...
MVFR CIGS CONTINUE TO SLOWLY ERODE FROM THE NORTH WHILE REMAINING
STEADY TO THE SOUTHWEST...RPJ/C09/IKK. CONFIDENCE REGARDING TRENDS
IS LOW BUT IF THEY CONTINUE...WILL LIKELY SEE SOME SCATTERING OF
LOW CLOUDS FROM THE NORTH OVERNIGHT...WITH CLEARING AT GYY/MDW
LIKELY TO BE LATER THIS MORNING. NORTHWEST WINDS 4-8KTS WILL
LIKELY BECOME LIGHT AND VRB WHERE CLOUDS CLEAR...WITH LIGHT
NORTHWEST WINDS THRU THE DAY AND BECOMING LIGHT AND VRB TONIGHT.
CMS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM FOR CIGS THRU THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
FRIDAY AND SATURDAY...DRY WITH VFR LIKELY...THOUGH MVFR POSSIBLE.
LIGHT AND VARIABLE WINDS.
SUNDAY...DRY. MVFR POSSIBLE. SOUTH WINDS.
MONDAY...CHANCE OF RAIN. MVFR LIKELY. GUSTY SOUTH WINDS...POSSIBLY
TURNING SOUTHEAST.
TUESDAY...CHANCE OF RAIN MIXED WITH SNOW. IFR POSSIBLE. SOUTHWEST
WINDS.
KMD
&&
.MARINE...
210 PM CST
THE LOW PRESSURE THAT PASSED THROUGH THE GREAT LAKES REGION OVER THE
PAST COUPLE DAYS IS IN THE PROCESS OF MERGING WITH ANOTHER LOW OVER
THE NEW ENGLAND COAST. THIS LOW WILL GRADUALLY DEEPEN AND SLOWLY
MOVE NORTH ALONG THE NEW ENGLAND COAST AS HIGH PRESSURE SPREADS FROM
THE NORTHERN PLAINS AND ACROSS THE WESTERN GREAT LAKES BY THURSDAY
MORNING. WINDS ARE SLOWLY SUBSIDING OVER THE LAKE...BUT A SECONDARY
TROUGH AND SURGE OF COOLER AIR MOVING DOWN THE LAKE THIS AFTERNOON
AND EVENING WILL KEEP RELATIVELY BRISK NLY-NLWY WINDS OVER THE LAKE
THROUGH THE NIGHT TONIGHT. WINDS SHOULD WEAKEN TO THE 10-15KT RANGE
THURSDAY NIGHT AND FRIDAY AS THE HIGH GRADUALLY SPREADS EAST...WHILE
MAINTAINING A NLY DIRECTION. THE HIGH WILL SPREAD ACROSS LAKE
MICHIGAN THURSDAY NIGHT AND FRIDAY...LEADING TO MORE LGT/VRBL WINDS
OVER THE LAKE. HIGH PRESSURE WILL VERY SLOWLY SPREAD EWD...BUT
STILL CONTROLLING FLOW OVER THE LAKE...KEEPING WINDS GENERALLY LIGHT
AND VARIABLE INTO THE WEEKEND. BY SUNDAY...THE HIGH WILL FINALLY
PUSH EAST OF LAKE MICHIGAN AS A TROUGH OF LOW PRESSURE DEVELOPS OVER
THE NORTHERN PLAINS. THIS WILL SET UP INCREASING SLY FLOW OVER THE
LAKE BY SUNDAY. A DEVELOPING LOW IS EXPECTED TO TRACK ACROSS THE
NRN PLAINS SUNDAY NIGHT AND MONDAY...REACHING THE MIDDLE MISSISSIPPI
VALLEY BY TUESDAY. THIS WILL KEEP GENERALLY SOUTHERLY WINDS OVER
THE LAKE THROUGH EARLY NEXT WEEK.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL
10 AM THURSDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1134 PM CST Wed Dec 17 2014
.UPDATE...
ISSUED AT 909 PM CST WED DEC 17 2014
Have already made one adjustment to cloud cover since it is not
clearing as fast as originally expected. Will be making another
adjustment for the same thing with high clouds advecting in from
the southwest. Pcpn is moving across MO and still expected to
arrive in western IL in the morning. Forecast still has good
handle on this. Most of forecast looks fine, but will be updating
to reflect current cloud trends. Update coming shortly.
&&
.SHORT TERM...(Tonight)
ISSUED AT 245 PM CST WED DEC 17 2014
19z/1pm satellite imagery continues to show overcast conditions
across much of central Illinois: however, the clouds are beginning
to erode northwest of the Illinois River. While HRRR guidance has
not been particularly useful in the short-term, satellite trends
suggest skies will partially clear across all but the far E/NE KILX
CWA by early evening. After a period of mostly clear skies early
tonight, clouds will once again begin increasing in advance of the
next storm system, which is currently evident on water vapor imagery
over west Texas. Quite a bit of precip and even some thunder is
occurring ahead of this wave over Oklahoma/Texas: however, it is
expected to weaken as it lifts northeastward into the region on
Thursday. It will also be coming into a dry airmass beneath a
prevailing surface ridge axis. Forecast soundings show gradual
moistening from the top-down later tonight, but the lowest levels
below 850mb will remain quite dry through 12z. As a result, have
maintained a dry forecast through the overnight hours. Due to the
initially clear skies and low dewpoints, have gone a couple of
degrees below MAV guidance for lows tonight, with readings dropping
into the teens and lower 20s.
&&
.LONG TERM...(Thursday through Wednesday)
ISSUED AT 245 PM CST WED DEC 17 2014
Upper flow will be zonal for next few days, with weak waves moving
east through flow. Moisture channel data and upper air shows initial
wave to affect region over NM this morning. This system to
continue tracking to the northeast, pushing some overrunning pcpn
into MO and southern 1/2 of IL for late tonight into Thursday. Weak
vort lobe and isentropic lift to be enough to move the light snow
into southern 1/2 of CWA in the morning, but wave moving fast enough
to only affect the morning. Mainly less than half inch.
Next wave to move into region for Friday night and Saturday morning
and the area of lift with this one is farther south, mainly over
southeast cwa. Again, some light snow possible.
Upper flow starts to change on late in weekend and by Monday, flow
is northwest. Digging upper trough over Great Lakes with upper low
closing off by Monday night. This will bring some initial pcpn into
the region ahead of cold front that moves through Tuesday.
Temperatures however, are only cold enough for possible mixture
until post frontal on Tuesday night and Wednesday. Therefore no snow
accumulation. However by Tues night to Wed, only minor vort lobes
rotating around the closed upper low in the cold air, so chance of
light snow accumulations only.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1134 PM CST WED DEC 17 2014
Clouds are still slowly exiting the area to the east. BMI, DEC,
and CMI still have broken to overcast clouds at MVFR levels. These
will eventually head east but broken cirrus has overspread all TAF
sites. As the next system advances closer to the area, clouds will
lower into the mid range to around 8kft at all sites sometime
during the morning, with SPI lower first. Models continue to show
very light snow getting to SPI only. So this is the only site
where I have cigs dropping to MVFR and having light snow/flurries
in the TAFs. All other sites will see slightly lower clouds to
around 5kft. Could be some MVFR cigs that slide over the other
sites, so will have TEMPO groups of 3-4 hrs for the others to
account for possible cigs around 3kft. During the late afternoon all
sites should see lower clouds scatter/dissipate with cirrus left
the rest of the evening. Winds will remain light and variable due
to the high pressure ridge sitting right over the area.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Auten
SHORT TERM...Barnes
LONG TERM...Goetsch
AVIATION...Auten
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1228 PM EST THU DEC 18 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 252 AM EST THU DEC 18 2014
HIGH PRESSURE IS EXPECTED ACROSS THE AREA THROUGH THE END OF THE
WEEK. THE NORTHERN FRINGES OF A LOW PRESSURE SYSTEM PASSING THROUGH
THE GULF COAST STATES MAY AFFECT PARTS OF THE AREA BY THE END OF
WEEK. A SIGNIFICANT LOW PRESSURE SYSTEM MAY MOVE INTO THE AREA BY
THE EARLY TO MIDDLE PARTS OF NEXT WEEK.
&&
.NEAR TERM /THIS AFTERNOON/...
ISSUED AT 956 AM EST THU DEC 18 2014
SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS HIGH PRESSURE IN PLACE
OVER THE UPPER MIDWEST AND THE OHIO VALLEY. RADAR RETURNS SHOW
ECHO ALOFT OVE MUCH OF CENTRAL ILLINOUIS...HOWEVER SURFACE OBS
ONLY REPORT SN FALLING ACROSS WEST CENTRAL ILLINOIS. HRRR TENDS TO
KEEP THE ONGOING PRECIP SOUTH OF CENTRAL INDIANA AND WANES THE
ONGOING PRECIP OVER WESTERN ILLINOIS. ATTM...THE HRRR DOESN/T
APPEAR HANDLE THE ONGOING SITUTAION WELL. GFS 285K ISENTROPIC
SURFACE SHOWS GOOD UPGLIDE ACROSS MISSOURI...HELPING THE ONGOING
SNOW THERE. THIS FEAUTRE HOWEVER DOES NOT TRANSLATE WELL TO
CENTRAL INDIANA AS MODELS SUGGEST THE ISENTROPIC LIFT FAILS TO
REACH INDIANA. TIME HEIGHT SECTIONS CONTINUE TO SUGGEST GOOD MID
AND LOWER LEVEL MOISTURE AVAILABLE BETWEEN 18Z AND 00Z. CONFIDNECE
REMAINS LOW IN THIS EVENT...BUT WILL MONITOR CLOSELY. FOR NOW HAVE
ADDED SLIGHT CHC POPS TO MAINLY THE SOUTHERN PARTS OF THE FORECAST
AREA...WITH FLURRIES ELSEWHERE. WILL BE QUICK TO UPDATE SHOULD
ECHOS OVER ILLINOIS HOLD TOGETHER AND PRECIP BEGINS TO REACH THE
GROUND.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 252 AM EST THU DEC 18 2014
MODEL DATA SUGGEST THERE MAY STILL SOME REMNANT ENERGY MOVING
THROUGH THE AREA THIS EVENING ASSOCIATED WITH TODAY/S
DISTURBANCE...SO WILL EXTEND THE FLURRY MENTION INTO THE EVENING
HOURS TONIGHT.
OTHERWISE...A SPLIT FLOW IS EXPECTED TO DEVELOP BY THE END OF THE
WEEK AS THE UPPER BLOCK OVER SOUTHERN CANADA BREAKS DOWN. A SOUTHERN
STREAM DISTURBANCE IS EXPECTED TO SCOOT ALONG THE GULF COAST
STATES...WHILE A DRIER NORTHERN STREAM SYSTEM DIGS INTO THE GREAT
LAKES BY SATURDAY. OPERATIONAL GUIDANCE IS IN PRETTY GOOD AGREEMENT
IN KEEPING THE MAIN PRECIPITATION THREAT TIED UP IN THE SOUTHERN
STREAM AND WELL SOUTH OF THE LOCAL AREA. THERE ARE SOME ENSEMBLES
THAT DRAW ENOUGH MOISTURE NORTH FOR A THREAT FOR LIGHT SNOW AND
MINOR ACCUMULATIONS OVER THE SOUTHERN/SOUTHEASTERN ZONES LATE FRIDAY
NIGHT INTO SATURDAY. TO COVER THIS POSSIBILITY...WILL KEEP SOME
CHANCE POPS GOING FOR LIGHT SNOW DURING THOSE PERIODS OVER ABOUT THE
SOUTHEAST HALF OF THE FORECAST AREA.
GIVEN THE DEGREE OF CLOUD COVER EXPECTED OVER THE NEXT COUPLE OF
DAYS...WILL CONTINUE TO NARROW THE DIURNAL RANGE OF THE GFS MOS
TEMPERATURE GUIDANCE THROUGH THE PERIOD.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 340 AM EST THU DEC 18 2014
EXTENDED MODELS AND ENSEMBLES AGREE THAT STRONG PACIFIC JET...ARCING
OVER A HIGH AMPLITUDE WEST COAST UPPER RIDGE...WILL DIVE SOUTHEAST
OVER THE CENTRAL UNITED STATES DURING THE EARLY AND MIDDLE PART OF
NEXT WEEK RESULTING IN AN UPPER TROUGH CLOSING INTO AN UPPER LOW AND
INTENSIFYING INTO A VERY STRONG SYSTEM BEFORE IT MOVES INTO
SOUTHEASTERN CANADA ON CHRISTMAS. MODELS WERE NOT TOO FAR OFF
REGARDING STRENGTH AND TIMING OF THIS SYSTEM...SO A BLEND OF THE
FURTHER NORTH 00Z GFS AND FURTHER SOUTH 12Z ECMWF LOOKS GOOD.
00Z MODELS ARE SHOWING AN UPPER TROUGH OVER SOUTHEASTERN SOUTH
DAKOTA OR NORTHWESTERN IOWA AT 00Z TUESDAY WITH BROAD AREA OF UPPER
DIFFLUENT FLOW ALOFT OVER THE OHIO VALLEY AND GREAT LAKES.
MEANWHILE...LOW LEVEL FLOW WILL BE SOUTHERLY BY MONDAY AND OPEN THE
OHIO VALLEY AND GREAT LAKES TO THE GULF RESULTING IN DEEPENING
MOISTURE TO GO ALONG WITH THE UPPER FORCING. THIS WILL BRING RAIN TO
THE AREA BY MONDAY AS WELL AS ABOVE NORMAL TEMPERATURES. THE WARMER
TEMPERATURES AND RAIN WILL BE SHORT-LIVED...HOWEVER AS COLDER AIR
RUSHES IN FROM THE NORTHWEST ON THE BACK END OF THE SYSTEM LATE
TUESDAY OR TUESDAY NIGHT. ALONG WITH THE COLDER AIR...UPPER IMPULSES
WILL MOVE ACROSS THE AREA IN THE CYCLONIC FLOW IN THE WAKE OF THE
DEPARTING STACKED LOW THAT SHOULD MOVE INTO QUEBEC EARLY CHRISTMAS.
THIS SHOULD GENERATE SOME SNOW WITH LIGHT ACCUMULATION POSSIBLE BY
CHRISTMAS EVE.
00Z GFS ENSEMBLE MOS TEMPERATURES LOOK TOO WARM THIS WEEKEND.
STRONGLY PREFER THE COOLER 00Z DECEMBER 17 EUROPEAN ENSEMBLE MEAN
TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 18/1800Z TAF ISSUANCE/...
ISSUED AT 1208 PM EST THU DEC 18 2014
FLIGHT CONDITIONS WILL HOVER RIGHT AROUND THE MVFR/VFR MARK INTO
THE NIGHT. HOWEVER...TIME CROSS SECTIONS ARE LEANING TOWARD DRIER
CONDITIONS AT ALL LEVELS EARLY TOMORROW MORNING. SO...ANTICIPATE
SCATTERING SOME TIME BETWEEN FRI 09-15Z...WHICH IS REFLECTED IN
TAFS. AT THAT POINT...VFR SHOULD BE THE PREVAILING FLIGHT CATEGORY
THROUGH THE REMAINDER OF TAF PERIOD. NORTHWEST WINDS WILL VEER
SLIGHTLY TO THE NORTHEAST LATE TONIGHT...BUT WILL REMAIN LIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...PUMA
SHORT TERM...JAS
LONG TERM...MK
AVIATION...TDUD
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
957 AM EST THU DEC 18 2014
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 252 AM EST THU DEC 18 2014
HIGH PRESSURE IS EXPECTED ACROSS THE AREA THROUGH THE END OF THE
WEEK. THE NORTHERN FRINGES OF A LOW PRESSURE SYSTEM PASSING THROUGH
THE GULF COAST STATES MAY AFFECT PARTS OF THE AREA BY THE END OF
WEEK. A SIGNIFICANT LOW PRESSURE SYSTEM MAY MOVE INTO THE AREA BY
THE EARLY TO MIDDLE PARTS OF NEXT WEEK.
&&
.NEAR TERM /THIS AFTERNOON/...
ISSUED AT 956 AM EST THU DEC 18 2014
SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS HIGH PRESSURE IN PLACE
OVER THE UPPER MIDWEST AND THE OHIO VALLEY. RADAR RETURNS SHOW
ECHO ALOFT OVE MUCH OF CENTRAL ILLINOUIS...HOWEVER SURFACE OBS
ONLY REPORT SN FALLING ACROSS WEST CENTRAL ILLINOIS. HRRR TENDS TO
KEEP THE ONGOING PRECIP SOUTH OF CENTRAL INDIANA AND WANES THE
ONGOING PRECIP OVER WESTERN ILLINOIS. ATTM...THE HRRR DOESN/T
APPEAR HANDLE THE ONGOING SITUTAION WELL. GFS 285K ISENTROPIC
SURFACE SHOWS GOOD UPGLIDE ACROSS MISSOURI...HELPING THE ONGOING
SNOW THERE. THIS FEAUTRE HOWEVER DOES NOT TRANSLATE WELL TO
CENTRAL INDIANA AS MODELS SUGGEST THE ISENTROPIC LIFT FAILS TO
REACH INDIANA. TIME HEIGHT SECTIONS CONTINUE TO SUGGEST GOOD MID
AND LOWER LEVEL MOISTURE AVAILABLE BETWEEN 18Z AND 00Z. CONFIDNECE
REMAINS LOW IN THIS EVENT...BUT WILL MONITOR CLOSELY. FOR NOW HAVE
ADDED SLIGHT CHC POPS TO MAINLY THE SOUTHERN PARTS OF THE FORECAST
AREA...WITH FLURRIES ELSEWHERE. WILL BE QUICK TO UPDATE SHOULD
ECHOS OVER ILLINOIS HOLD TOGETHER AND PRECIP BEGINS TO REACH THE
GROUND.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 252 AM EST THU DEC 18 2014
MODEL DATA SUGGEST THERE MAY STILL SOME REMNANT ENERGY MOVING
THROUGH THE AREA THIS EVENING ASSOCIATED WITH TODAY/S
DISTURBANCE...SO WILL EXTEND THE FLURRY MENTION INTO THE EVENING
HOURS TONIGHT.
OTHERWISE...A SPLIT FLOW IS EXPECTED TO DEVELOP BY THE END OF THE
WEEK AS THE UPPER BLOCK OVER SOUTHERN CANADA BREAKS DOWN. A SOUTHERN
STREAM DISTURBANCE IS EXPECTED TO SCOOT ALONG THE GULF COAST
STATES...WHILE A DRIER NORTHERN STREAM SYSTEM DIGS INTO THE GREAT
LAKES BY SATURDAY. OPERATIONAL GUIDANCE IS IN PRETTY GOOD AGREEMENT
IN KEEPING THE MAIN PRECIPITATION THREAT TIED UP IN THE SOUTHERN
STREAM AND WELL SOUTH OF THE LOCAL AREA. THERE ARE SOME ENSEMBLES
THAT DRAW ENOUGH MOISTURE NORTH FOR A THREAT FOR LIGHT SNOW AND
MINOR ACCUMULATIONS OVER THE SOUTHERN/SOUTHEASTERN ZONES LATE FRIDAY
NIGHT INTO SATURDAY. TO COVER THIS POSSIBILITY...WILL KEEP SOME
CHANCE POPS GOING FOR LIGHT SNOW DURING THOSE PERIODS OVER ABOUT THE
SOUTHEAST HALF OF THE FORECAST AREA.
GIVEN THE DEGREE OF CLOUD COVER EXPECTED OVER THE NEXT COUPLE OF
DAYS...WILL CONTINUE TO NARROW THE DIURNAL RANGE OF THE GFS MOS
TEMPERATURE GUIDANCE THROUGH THE PERIOD.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 340 AM EST THU DEC 18 2014
EXTENDED MODELS AND ENSEMBLES AGREE THAT STRONG PACIFIC JET...ARCING
OVER A HIGH AMPLITUDE WEST COAST UPPER RIDGE...WILL DIVE SOUTHEAST
OVER THE CENTRAL UNITED STATES DURING THE EARLY AND MIDDLE PART OF
NEXT WEEK RESULTING IN AN UPPER TROUGH CLOSING INTO AN UPPER LOW AND
INTENSIFYING INTO A VERY STRONG SYSTEM BEFORE IT MOVES INTO
SOUTHEASTERN CANADA ON CHRISTMAS. MODELS WERE NOT TOO FAR OFF
REGARDING STRENGTH AND TIMING OF THIS SYSTEM...SO A BLEND OF THE
FURTHER NORTH 00Z GFS AND FURTHER SOUTH 12Z ECMWF LOOKS GOOD.
00Z MODELS ARE SHOWING AN UPPER TROUGH OVER SOUTHEASTERN SOUTH
DAKOTA OR NORTHWESTERN IOWA AT 00Z TUESDAY WITH BROAD AREA OF UPPER
DIFFLUENT FLOW ALOFT OVER THE OHIO VALLEY AND GREAT LAKES.
MEANWHILE...LOW LEVEL FLOW WILL BE SOUTHERLY BY MONDAY AND OPEN THE
OHIO VALLEY AND GREAT LAKES TO THE GULF RESULTING IN DEEPENING
MOISTURE TO GO ALONG WITH THE UPPER FORCING. THIS WILL BRING RAIN TO
THE AREA BY MONDAY AS WELL AS ABOVE NORMAL TEMPERATURES. THE WARMER
TEMPERATURES AND RAIN WILL BE SHORT-LIVED...HOWEVER AS COLDER AIR
RUSHES IN FROM THE NORTHWEST ON THE BACK END OF THE SYSTEM LATE
TUESDAY OR TUESDAY NIGHT. ALONG WITH THE COLDER AIR...UPPER IMPULSES
WILL MOVE ACROSS THE AREA IN THE CYCLONIC FLOW IN THE WAKE OF THE
DEPARTING STACKED LOW THAT SHOULD MOVE INTO QUEBEC EARLY CHRISTMAS.
THIS SHOULD GENERATE SOME SNOW WITH LIGHT ACCUMULATION POSSIBLE BY
CHRISTMAS EVE.
00Z GFS ENSEMBLE MOS TEMPERATURES LOOK TOO WARM THIS WEEKEND.
STRONGLY PREFER THE COOLER 00Z DECEMBER 17 EUROPEAN ENSEMBLE MEAN
TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 18/1500Z TAF UPDATE/...
ISSUED AT 907 AM EST THU DEC 18 2014
UPDATE...
NO FLIGHT CATEGORY CHANGES.
PREVIOUS DISCUSSION...
GOOD CONFIDENCE THAT CLOUDS WILL CONTINUE TO BLANKET THE
TERMINALS THROUGH THE TAF PERIOD. THINK CONDITIONS WILL MOSTLY BE
VFR...ALTHOUGH WOULD NOT RULE OUT SOME MVFR AT TIMES.
WINDS WILL BE 5 KNOTS OR LESS THROUGHOUT UNDER SURFACE HIGH
PRESSURE.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...PUMA
SHORT TERM...JAS
LONG TERM...MK
AVIATION...MK/TDUD
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
332 PM CST THU DEC 18 2014
.SHORT TERM /TONIGHT/...
ISSUED AT 324 PM CST THU DEC 18 2014
SNOW HAS ENDED OVER THE SOUTHEASTERN CWA AS THE CULPRIT UPPER LEVEL
WAVE HAS RAPIDLY WEAKENED AND DGZ FORCING HAS WANED. BASED ON WEBCAM
IMAGES AND A FEW SPOTTER/COOP REPORTS...MOST AREAS IN THE SOUTHERN
THREE TIERS OF COUNTIES SAW LESS THAN AN INCH OF SNOW. ATTENTION NOW
TURNS UPSTREAM TO A LARGE STRATUS PLUME STRETCHING FROM NORTHWEST
MONTANA TO THE TEXAS PANHANDLE...WITH THE EASTERN FRONT NOW JUST
ABOUT TO ENTER THE WESTERN CWA. LIGHT WEST TO SOUTHWEST FLOW IN THE
LOWEST 1 KM OF THE ATMOSPHERE BEHIND A DEPARTING SURFACE RIDGE
SHOULD ADVECT THIS CLOUD MASS OVER CENTRAL IOWA TONIGHT AND KEEP
SKIES OVERCAST ALL NIGHT AND INTO TOMORROW MORNING. THE CLOUDS
SHOULD ALSO BOLSTER LOW TEMPS TONIGHT COMPARED TO PREVIOUS NIGHTS
AND DIDN`T DEVIATE MUCH FROM GUIDANCE IN THIS RESPECT.
THE BIGGEST UNCERTAINTY FOR TONIGHT IS THE POSSIBILITY OF FLURRIES
OR FREEZING DRIZZLE WEST OF I-35. SHORT-RANGE MODEL SOUNDINGS (RUC
AND HRRR IN PARTICULAR) SATURATE THE LOWEST 5 KFT OF THE ATMOSPHERE
IN THIS REGION TONIGHT WITH NEARLY ISOTHERMAL PROFILES IN THIS LAYER
HOVERING BETWEEN -4 AND -7C. WITH THIS CONDITIONAL ICE PROBABILITY
...WENT WITH A MIX OF OCCASIONAL FLURRIES AND PATCHY FZDZ. FORCING
SHOULD BE MARGINAL AT BEST AND NO ACCUMULATION OF SNOW OR ICE IS
ANTICIPATED. ANY LIFT WITH AN UPPER LEVEL TROUGH ON WATER VAPOR
IMAGERY NW OF THE CWA SHOULD STAY NORTH AND EAST OF THE AREA.
ISENTROPIC UPGLIDE IN THE LOWEST 100MB OF THE ATMOSPHERE IS
PRESENT...BUT AGAIN VERY WEAK.
.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 324 PM CST THU DEC 18 2014
THE WEATHER IN THE LONG TERM WILL IN GENERAL BE MORE ACTIVE THEN
WHAT WE HAVE SEEN IN A WHILE. FRIDAY THROUGH SUNDAY THERE WILL BE
NUMEROUS RELATIVELY WEAK SHORT WAVES MOVE ACROSS IOWA IN A GENERALLY
ZONAL FLOW. THROUGH SATURDAY MOISTURE WILL EITHER BE SPARSE OR
SHALLOW SO I AM NOT EXPECTING MUCH WITH THESE SHORTWAVES IN TERMS OF
SENSIBLE WEATHER EXCEPT FOR CLOUD COVER. TEMPS SHOULD BE RATHER
MILD FOR MID TO LATE DECEMBER.
SATURDAY NIGHT THROUGH SUNDAY A LITTLE STRONGER SHORT WAVE MOVES IN
AND MOISTURE DEPTH INCREASES SLIGHTLY ALTHOUGH IT IS STILL VERY
SHALLOW. SOUNDINGS DO NOT INDICATE ICE INTRODUCTION AND WHILE THERE
ARE MODEL DIFFERENCES AS TO WHERE ANY WEAK FORCING MIGHT OCCUR...IT
DOES APPEAR THAT THE NORTHERN HALF OF IOWA IS MORE LIKELY TO SEE
THIS THAN SOUTHERN IOWA. AS A RESULT I KEPT THE MENTION OF FREEZING
DRIZZLE CONFINED TO THE NORTH. THE SOUNDING DOES SATURATE
OR BEGIN TO SATURATE SUFFICIENTLY LATE SATURDAY NIGHT THROUGH
SUNDAY MORNING THROUGH THE DENDRITIC ZONE THAT WE COULD TRANSITION
TO SOME LIGHT SNOW UP NORTH...ESPECIALLY SUNDAY MORNING. THAT
SHORTWAVE EXITS DURING THE EARLY AFTERNOON AND TEMPS WARM
SUFFICIENTLY FOR A WINTERY MIX CHANGING TO RAIN ACROSS AT LEAST
SOME OF THE AREA.
SUNDAY NIGHT THROUGH MONDAY A MORE POTENT SHORTWAVE MOVES INTO
IOWA...AFFECTING THE WEST SUNDAY NIGHT AND THE REST OF THE AREA
THROUGH TUESDAY. HERE MODELS DIVERGE ON HOW TO HANDLE THIS SYSTEM.
THE GFS KEEP THE UPPER LEVEL WAVE OPEN AND DEVELOPS A CLOSED SURFACE
LOW OVER CENTRAL TO NORTHEAST IOWA. THE EURO DRASTICALLY DEPEND
THE UPPER WAVE TO OUR WEST THEN CONTINUES TO DEVELOP IT INTO A
CLOSED LOW MONDAY NIGHT AND TUESDAY ACROSS EASTERN IOWA. THE
RESULTANT CLOSED SURFACE LOW IS OVER EASTERN IOWA AS WELL AND
FURTHER SOUTHWEST THAN THE GFS HAS. THE GFS REALLY DEVELOPS THE QG
FORCING ACROSS CENTRAL IOWA SUNDAY NIGHT THEN IS SIGNIFICANTLY
WEAKER THROUGH TUESDAY. SOUNDINGS SHOW A PROFILE THAT IS PRETTY
WARM THROUGH MONDAY AFTERNOON WHEN THE PROFILE COOLS TO BELOW
FREEZING. PRECIP THROUGH EARLY MONDAY AFTERNOON SHOULD BE RAIN WITH
AN OCCASIONAL WINTERY MIX ESPECIALLY UP NORTH. DURING THE AFTERNOON
WE WILL BE TRANSITIONING TO A RAIN/SNOW MIX BEFORE GOING TO ALL SNOW
MONDAY NIGHT. IT IS TOO FAR OUT TO CONSIDER SNOWFALL AMOUNTS YET
AND GIVEN THE MODEL DISCREPANCIES IT WOULD BE HARD TO DO AT THIS
POINT.
THAT SYSTEM PULLS OUT BY CHRISTMAS EVE LEAVING US WITH SEASONAL
TEMPS AND MAINLY DRY. ANOTHER SYSTEM PUSHES IN FOR THURSDAY NIGHT
AND FRIDAY AND GIVEN THE STRENGTH OF THE TROUGH OVER US THAT FAR OUT
WE WILL GET SOME PRECIP OUT OF THE SYSTEM BUT MODEL DISCREPANCIES
ARE TOO BIG TO GIVE MUCH IN THE WAY OF TIMING AND AMOUNT DETAILS.
&&
.AVIATION...18/18Z
ISSUED AT 1141 AM CST THU DEC 18 2014
SNOW IS WINDING DOWN ACROSS SOUTHERN IOWA THIS AFTERNOON WITH IFR
TO LOW MVFR CEILINGS LINGERING OVER THE AREA. IFR/LOW MVFR STRATUS
IS ALSO HANGING ON ACROSS PORTIONS OF NE IOWA. EXPECT LITTLE
IMPROVEMENT THROUGHOUT THE DAY WITH A LARGE SHIELD OF MVFR TO IFR
STRATUS OVER NEBRASKA AND WESTERN IOWA ADVECTING OVER CENTRAL IOWA
TONIGHT AND LINGERING THROUGH THE END OF THE TAF PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SKOW
LONG TERM...FAB
AVIATION...SKOW
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1141 PM CST WED DEC 17 2014
.SHORT TERM /TONIGHT/...
ISSUED AT 245 PM CST WED DEC 17 2014
A QUIET AFTERNOON IS IN STORE FOR THE CWA WITH SURFACE HIGH PRESSURE
ANCHORED ALONG THE MISSOURI RIVER VALLEY. A SHARP 300 MB SHORTWAVE
TROUGH CURRENTLY EJECTING FROM THE FOUR CORNERS REGION WILL ENTER
SOUTHWEST IOWA BY 12Z THURSDAY. NAM/GFS ARE TOO SLOW WITH RETURNING
MID-LEVEL MOISTURE (MANIFESTING ITSELF AS AN ALTOSTRATUS DECK) NOW
WELL INTO SW IOWA AS WELL AS WITH PRECIP COVERAGE WITH THIS SYSTEM
IN OKLAHOMA. THE HRRR BEST REFLECTS REALITY IN TERMS OF PRECIP
COVERAGE BUT IS ABOUT 3 HOURS BEHIND THE CURVE WITH CLOUD PLACEMENT.
HAVE SUBSEQUENTLY MANUALLY INCREASED CLOUD COVER OVER THE SW HALF OF
THE CWA AND USED THE HRRR FOR TIMING THE ONSET OF SNOW IN THE
SOUTHWESTERN CWA. LOW TEMPERATURES TONIGHT...ESPECIALLY OVER THE
NORTH...WILL BE DEPENDENT ON HOW QUICKLY CLOUDS CAN ADVECT OVERHEAD.
THESE WILL NEED TO BE MONITORED THIS EVENING AND ADJUSTED UPWARD
SHOULD THE CLOUDS ADVANCE FASTER THAN CURRENTLY FORECAST.
THE FASTER MOISTURE RETURN THROWS JUST ANOTHER WRENCH IN TIMING AND
AMOUNTS OF SNOWFALL IN SOUTHERN IOWA LATE TONIGHT. 12/18Z MODEL BUFR
SOUNDINGS DEPICT A STOUT 925-850MB DRY WEDGE ATTENDANT WITH THE
SURFACE RIDGE...BUT THIS MIDLEVEL MOISTURE MAY SATURATE THE COLUMN
FASTER THAN PROGGED AND LEAD TO HIGHER SNOWFALL TOTALS. OVERALL MADE
LITTLE CHANGES TO THE FORECAST IN THIS RESPECT...BUT DID TIGHTEN THE
POP GRADIENT AS IT ADVANCES NORTHEAST FROM 09 TO 12Z THINKING THAT
THE LOW LEVEL DRY AIR WILL RESULT IN A SHARP CUTOFF IN ACCUMULATING
SNOW.
.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 245 PM CST WED DEC 17 2014
A FEW CHALLENGES OVER THE EXTENDED PERIOD...WITH A NUMBER OF WEAK
SYSTEMS TO AFFECT PORTIONS OF THE AREA THROUGH THE PERIOD. SPLIT
FLOW CONTINUES TO BE THE MAIN DRIVING FORCE BEHIND THE RATHER
QUIESCENT WEATHER FOR MID DECEMBER. RATHER HIGH AMPLITUDE RIDGE OF
HIGH PRESSURE STILL ANCHORED FROM THE NORTHERN PLAINS TO THE GULF
COAST NEXT FEW DAYS. FIRST WAVE CURRENTLY OVER THE SOUTHERN
PLAINS TODAY AND SHOULD MOVE NORTHEAST THROUGH THU MORNING. AHEAD
OF THE WEAK SYSTEM WARM AIR ADVECTION AND LIMITED MOISTURE WILL BE
FORCED UPWARD IN AN AREA OF ISENTROPIC LIFT OVER SOUTHERN IOWA
THURSDAY. THE LIFT AND MOISTURE WILL BE ATTEMPTING TO OVERCOME THE
DRY AIRMASS CURRENTLY IN PLACE...LIMITING OVERALL AMOUNTS. THIS
WILL RESULT IN SOME RATHER LIGHT SNOW DURING THE MORNING HOURS
WITH MINOR ACCUMULATIONS GENERALLY LESS THAN AN INCH. DURING THE
EARLY AFTERNOON HOURS...BUFR SOUNDINGS SHOW THAT WE LOSE ICE
INTRODUCTION ACROSS THE SOUTHWEST AND SOUTH. HAVE INTRODUCED SOME
PATCHY FREEZING DRIZZLE ALONG WITH VERY LIGHT SNOW DURING THE
AFTERNOON HOURS...THOUGH EXPECTATIONS ARE THAT ANY PRECIPITATION
BY THAT TIME WILL BE VERY LIGHT AND LITTLE IF ANY ICE ACCUMULATION
IS EXPECTED. NEXT SYSTEM ARRIVES BY SUNDAY AND MONDAY AND EXTENDS
INTO TUESDAY. LOWER CONFIDENCE MOVING FORWARD WITH A CONSENSUS
SOLUTION AS THE GFS IS QUITE MILD WHILE THE EURO IS NOW SUGGESTING
A SOLUTION WITH MORE SIGNIFICANT DYNAMIC COOLING AS THE PRECIP
ARRIVES INTO MONDAY. THE EURO SUGGESTS MORE SNOW THAN RAIN/SNOW
MIX. GIVEN THE EVENT IS STILL 5 DAYS AWAY...WILL HOLD ONTO CURRENT
MIX TRENDS FOR NOW...AND MONITOR DURING SUBSEQUENT MODEL PACKAGES.
THE ONE TREND THAT IS BEGINNING TO EMERGE IS COLDER AIR AS NEXT
WEEK PROGRESSES. AS A STRONG PACNW STREAM WAVE ADVANCES EAST INTO
THE WESTERN STATES...MIDWEST RIDGE FINALLY BEGINS TO BREAK DOWN
AND BECOME DISPLACED BY A LONG WAVE TROUGH. THIS SHOULD SPELL A
TRANSITION TO A MORE ACTIVE AND COLDER PATTERN TOWARD THE END OF
THE EXTENDED. AS THE WAVE TUESDAY DEEPENS...A RATHER STRONG SFC
WAVE WILL EJECT NORTH NORTHEAST OUT OF EASTERN TEXAS TO EASTERN
MICHIGAN WEDNESDAY. GIVEN THE CURRENT GFS/EURO PACKAGES...THE MAIN
H850 MOISTURE PLUME...BETTER FORCING...AND HIGHER PRECIPITATION
AMOUNTS WILL PROBABLY END UP EAST OF THE REGION. WILL MONITOR FOR
GENERAL WESTWARD DRIFT NEXT SEVERAL PACKAGES...THIS SOMETIMES
OCCURS WITH WINTER STORM EVOLUTION IN MODEL PACKAGES...FIRST
PROJECTING THE EVENT TOO FAR EAST THEN PULLING IT BACK AS THE
EVENT NEARS.
&&
.AVIATION...18/06Z
ISSUED AT 1140 PM CST WED DEC 17 2014
SYSTEM ACROSS PLAINS WILL CONTINUE TO LIFT NORTHEAST THROUGH
THURSDAY. CLOUDS WILL MOVE INTO IOWA WITH PRIMARILY MID AND HIGH
CLOUDINESS OVERNIGHT AND VFR CONDITIONS. AS DEEPER SATURATION
APPROACHES FROM THE SOUTH TOWARD DAYBREAK...MVFR TO IFR CONDITIONS
NEAR THE MISSOURI BORDER ARE EXPECTED ALTHOUGH DRIER LOW LEVEL AIR
WILL KEEP LOCATIONS FARTHER NORTH VFR. THERE WILL BE SOME LOW
LEVEL CLOUDS NEAR KMCW OVERNIGHT NEAR RIDGE AXIS AND THIS MAY
LINGER INTO THURSDAY MORNING AS FLOW REMAINS QUITE LIGHT. WITH
PASSAGE OF SYSTEM ON THURSDAY...THREAT OF PRECIPITATION IN THE
SOUTH WILL END AFTER MIDDAY. HOWEVER...LOW TO MID LEVEL MOISTURE
WILL REMAIN WITH WIDESPREAD STATUS EXPECTED TO PERSIST THROUGH THE
END OF THE FORECAST.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SKOW
LONG TERM...REV
AVIATION...COGIL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1045 AM MST THU DEC 18 2014
.UPDATE...
ISSUED AT 902 AM MST THU DEC 18 2014
UPDATE WAS JUST COMPLETED FOR THE RECENT EXPIRATION OF THE DENSE
FOG ADVISORY. SOME FOG WILL CONTINUE FOR THE NEXT HOUR OR SO.
UPDATE ISSUED AT 554 AM MST THU DEC 18 2014
EARLIER UPDATE WAS TO ISSUE DENSE FOG ADVISORY FOR OUR CWA. DENSE
FOG DEVELOPED FROM OAKLEY TO TRIBUNE TO BURLINGTON...BUT HAS BEEN
A BIT MORE VARIABLE ALONG THE KS/CO BORDER. SHORT RANGE GUIDANCE
GENERALLY FAVORS THE WESTERN PART OF THE CWA...THOUGH RAP DOES
SHOW THE PATCH OF FOG NEAR OAKLEY SPREADING A LITTLE BIT MORE TO
THE NORTH AND EAST TOWARD GRAHAM COUNTY. I AM NOT AS SURE ABOUT
HRRR WHICH ACTUALLY SHOWED FOG EXPANDING FROM THE COLORADO BORDER
TO THE EAST AND LINGERING THROUGH THE AFTERNOON. HIGHER SURFACE TD
VALUES ARE IN OUR EAST AND LIGHT FOG IS IN PLACE. I WOULD NOT BE
SURPRISED IF DENSE FOG COVERAGE INCREASED AND SPREAD EAST AROUND
OR AFTER SUNRISE...SO I DECIDED TO COVER THE ENTIRE AREA FOR THE
ADVISORY.
WHILE CURRENT DENSE FOG COVERAGE IS SOMEWHAT PATCHY...ROAD
CONDITIONS AFTER YESTERDAYS FREEZING DRIZZLE AND LAST NIGHTS LIGHT
SNOW ARE IN POOR CONDITION ACROSS MANY LOCATIONS. EVEN PATCHY
DENSE FOG WITH THESE ROAD CONDITIONS WOULD MAKE TRAVEL DANGEROUS.
I FELT MORE COMFORTABLE WITH A DENSE FOG ADVISORY THAN SPS DESPITE
THE VARIABLE NATURE OF THE CONDITIONS SO FAR THIS MORNING.
UPDATE ISSUED AT 412 AM MST THU DEC 18 2014
UPDATE TO CANCEL WINTER WEATHER ADVISORY. SNOW BAND HAS FALLEN
APART AND FREEZING DRIZZLE HAS COME TO AN END. UPPER LOW IS NOW
OVER NORTHEAST KS/SOUTHEAST NE. WHILE GOOD LOW LEVEL MOISTURE IS
SUPPORTING DENSE FOG REDEVELOPMENT...BETTER MOISTURE ADVECTION
WILL REMAIN EAST OF THE CWA THROUGH THE REST OF THE MORNING...SO
FREEZING DRIZZLE THREAT IS MINIMAL. I CANT JUSTIFY A WINTER
WEATHER ADVISORY JUST FOR FREEZING FOG...BUT FELT THE NEED TO KEEP
A SPS OUT TO COVER FREEZING FOG POTENTIAL. WILL MONITOR OVER THE
NEXT HOUR AND IF FOG CONTINUES TO INCREASE IN COVERAGE I MAY NEED
TO ISSUE DENSE FOG ADVISORY FOR THE MORNING HOURS.
&&
.SHORT TERM...(THIS MORNING THROUGH SATURDAY NIGHT)
ISSUED AT 244 AM MST THU DEC 18 2014
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW SHORTWAVE
TROUGH OVER NORTHCENTRAL KANSAS WITH AREA OF SUBSIDENCE ALONG
SHORTWAVE RIDGE AXIS BUILDING INTO THE NEBRASKA PANHANDLE. AT THE
SURFACE A STATIONARY FRONT REMAINS IN PLACE OVER EASTERN COLORADO
WITH SOUTH TO SOUTHEAST FLOW IN PLACE ACROSS OUR CWA.
REGARDING WINTER WEATHER ADVISORY EARLY THIS MORNING....
RADAR AND SURROUNDING OBS SHOW A BAND OF LIGHT SNOW THAT FORMED ON
BACK SIDE OF H7 LOW MOVING EAST OVER OUR EASTERN CWA. THIS SNOW HAS
HELPED MIX OUT THE LOW LEVELS OF THE ATMOSPHERE WITH SHIFT IN LOW
LEVEL FLOW TO THE NORTHWEST AIDING IMPROVEMENT IN CONDITIONS
ACROSS THE WESTERN FORECAST AREA. BASED ON SHORT RANGE MODELS...I
AM STILL CONCERNED THAT LIGHT WINDS AND SHALLOW LOW LEVEL MOISTURE
COULD LEAD TO FREEZING FOG REDEVELOPMENT BEHIND THIS SNOW BAND.
FREEZING FOG/DRIZZLE WILL REMAIN POSSIBLE AHEAD OF IT WITH BETTER
MOISTURE ADVECTION/POOLING. OVERALL TREND THROUGH THE MORNING
SHOULD BE IMPROVEMENT IN CONDITIONS AROUND 12-15Z...WITH ANY FOG
CLEARING BY MIDDAY. AFTER 12Z I AM SKEPTICAL THAT FLOW WOULD ALLOW
FOR ENOUGH ADDITIONAL MOISTURE ADVECTION TO SUPPORT CONTINUED
FREEZING DRIZZLE...THOUGH FOG COULD BE POSSIBLE THROUGH MOST OF
THE MORNING ESPECIALLY IN THE EAST WHERE SOUTHERLY FLOW MAY LINGER
A LITTLE LONGER. WITH THIS IN MIND I PLAN ON HOLDING ONTO CURRENT
WINTER WEATHER ADVISORY THROUGH EXPIRATION IN CASE I NEED TO
EXTEND IT IN TIME FOR EASTERN LOCATIONS THROUGH 15Z.
REST OF TODAY...SHORTWAVE RIDGING WILL CONTINUE TO BUILD EAST
TODAY AND AIR MASS WILL BEING MODERATING AND DRYING AS SURFACE
TROUGH SHIFTS EAST. THERE MAYBE DECENT CLEARING WHICH COULD
SUPPORT TEMPS IN THE LOWER 40S (FOR LOCATIONS WITHOUT SNOW PACK).
IT IS TOUGH TO SAY HOW MUCH CLEARING AS MODELS HOLD ONTO STRATUS
OVER PARTS OF THE AREA INTO THE AFTERNOON. NOT A LOT OF
CONFIDENCE IN TEMPS...SO MADE MINOR ADJUSTMENT TO TODAYS HIGHS.
TONIGHT-SATURDAY NIGHT...A SHORTWAVE TROUGH WILL PASS THROUGH THE
SOUTHERN PLAINS THROUGH FRIDAY MORNING...WITH MINIMAL IMPACT ON
SENSIBLE WEATHER OVER OUR CWA. NAM AND SREF BL RH CONTINUE TO RUN
HIGH...LIKELY AS A RESULT OF SNOW PACK...AND SUPPORT FOG/STRATUS
DURING THE OVERNIGHT PERIODS. I ADDED PATCHY FOG TO TONIGHT AS
WINDS WILL BE LIGHT AND THERE COULD BE SOME LINGERING BL MOISTURE
POOLING ALONG AND EAST OF SURFACE TROUGH...THOUGH CONFIDENCE IS
PRETTY LOW AS TROUGH MAY BE EAST OF OUR CWA. THOUGH TEMPS WILL BE
SUBFREEZING...CONFIDENCE IS TOO LOW THAT ANY FOG WOULD BE DENSE
ENOUGH TO WORRY ABOUT ICE ACCUMULATION (FREEZING FOG). I AM
LEAVING FOG OUT OF FRIDAY NIGHT AND SATURDAY NIGHT TO SEE HOW
THINGS EVOLVE TONIGHT FIRST. SHORTWAVE RIDGE SHOULD BUILD BACK
OVER THE PLAINS FRIDAY THROUGH SATURDAY...WITH CONTINUED
MODERATION OF THE AIR MASS ALOFT. COMPLICATION TO TEMP FORECAST
WILL CONTINUE TO BE IMPACT OF DEEPER SNOW PACK IN OUR NORTHWEST
CWA.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 244 AM MST THU DEC 18 2014
THE LONG TERM PERIOD WILL START OUT WITH SLIGHTLY ABOVE AVERAGE
TEMPERATURES ON SUNDAY WITH WARM SOUTHERLY WINDS KEEPING
TEMPERATURES IN THE MID TO UPPER 40S. THE NEXT WEATHER MAKING
SYSTEM WILL APPROACH THE HIGH PLAINS REGION AS AN UPPER LEVEL TROUGH
AND SURFACE LOW PRESSURE SYSTEM MOVE ACROSS THE NORTHERN PLAINS.
THIS SYSTEM WILL BRING IN COLDER AIR TO THE PLAINS WITH CHANCES FOR
PRECIPITATION STARTING EARLY MONDAY MORNING...MOSTLY FOR EASTERN
COLORADO LOCATIONS.
PRECIPITATION MONDAY WILL BEGIN AS SNOW IN THE MORNING WITH COOLER
TEMPERATURES AT THE LOWER LEVELS...BUT WILL BECOME RAIN IN THE
AFTERNOON WITH HIGH TEMPERATURES REACHING THE MID 40S TO LOWER 50S.
AFTER SUNSET...PRECIPITATION WILL TRANSITION BACK TO SNOW THROUGH
THE OVERNIGHT HOURS. UNDER AN INCH OF SNOW IS POSSIBLE WITH THIS
SYSTEM.
THE UPPER LEVEL LOW IS DEPICTED IN GUIDANCE AS STALLING OVER THE
UPPER MIDWEST STATES...BUT THE TRI STATE AREA WILL BE UNDER THE
INFLUENCE OF STRONG NORTHWEST FLOW TUESDAY AS AN UPPER LEVEL RIDGE
BUILDS IN THE WEST. THE HIGHER AMPLITUDE RIDGE WILL BREAK DOWN AND
MOVE WESTWARD TO BRING A SHORTWAVE RIDGE OF HIGH PRESSURE OVER THE
CENTRAL PLAINS TO BRING DRY CONDITIONS AND NEAR AVERAGE TEMPERATURES
FOR TUESDAY AND WEDNESDAY. HIGH TEMPERATURES WILL RANGE FROM THE
UPPER 30S TO MID 40S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1041 AM MST THU DEC 18 2014
FOR KGLD...IFR NEAR LIFR CONDITIONS WILL END WITHIN THE NEXT HOUR.
AFTER THAT VFR CONDITIONS ARE EXPECTED THROUGH THE REST OF THE
PERIOD. SOME FOG COULD BE NEAR KGLD DURING THE NIGHT/EARLY MORNING
HOURS. HOWEVER...AM THINKING BECAUSE OF INCREASED MID/UPPER LEVEL
SKY COVER AND DOWNSLOPE WINDS...FOG WILL NOT AFFECT THE SITE.
FOR KMCK...IFR CEILINGS ARE EXPECTED FOR THE NEXT TWO TO THREE
HOURS BEFORE CLEARING. FROM 06Z TO 15Z...MVFR VISIBILITIES WILL
OCCUR.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...DR
LONG TERM...MK
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
907 AM MST THU DEC 18 2014
.UPDATE...
ISSUED AT 902 AM MST THU DEC 18 2014
UPDATE WAS JUST COMPLETED FOR THE RECENT EXPIRATION OF THE DENSE
FOG ADVISORY. SOME FOG WILL CONTINUE FOR THE NEXT HOUR OR SO.
UPDATE ISSUED AT 554 AM MST THU DEC 18 2014
EARLIER UPDATE WAS TO ISSUE DENSE FOG ADVISORY FOR OUR CWA. DENSE
FOG DEVELOPED FROM OAKLEY TO TRIBUNE TO BURLINGTON...BUT HAS BEEN
A BIT MORE VARIABLE ALONG THE KS/CO BORDER. SHORT RANGE GUIDANCE
GENERALLY FAVORS THE WESTERN PART OF THE CWA...THOUGH RAP DOES
SHOW THE PATCH OF FOG NEAR OAKLEY SPREADING A LITTLE BIT MORE TO
THE NORTH AND EAST TOWARD GRAHAM COUNTY. I AM NOT AS SURE ABOUT
HRRR WHICH ACTUALLY SHOWED FOG EXPANDING FROM THE COLORADO BORDER
TO THE EAST AND LINGERING THROUGH THE AFTERNOON. HIGHER SURFACE TD
VALUES ARE IN OUR EAST AND LIGHT FOG IS IN PLACE. I WOULD NOT BE
SURPRISED IF DENSE FOG COVERAGE INCREASED AND SPREAD EAST AROUND
OR AFTER SUNRISE...SO I DECIDED TO COVER THE ENTIRE AREA FOR THE
ADVISORY.
WHILE CURRENT DENSE FOG COVERAGE IS SOMEWHAT PATCHY...ROAD
CONDITIONS AFTER YESTERDAYS FREEZING DRIZZLE AND LAST NIGHTS LIGHT
SNOW ARE IN POOR CONDITION ACROSS MANY LOCATIONS. EVEN PATCHY
DENSE FOG WITH THESE ROAD CONDITIONS WOULD MAKE TRAVEL DANGEROUS.
I FELT MORE COMFORTABLE WITH A DENSE FOG ADVISORY THAN SPS DESPITE
THE VARIABLE NATURE OF THE CONDITIONS SO FAR THIS MORNING.
UPDATE ISSUED AT 412 AM MST THU DEC 18 2014
UPDATE TO CANCEL WINTER WEATHER ADVISORY. SNOW BAND HAS FALLEN
APART AND FREEZING DRIZZLE HAS COME TO AN END. UPPER LOW IS NOW
OVER NORTHEAST KS/SOUTHEAST NE. WHILE GOOD LOW LEVEL MOISTURE IS
SUPPORTING DENSE FOG REDEVELOPMENT...BETTER MOISTURE ADVECTION
WILL REMAIN EAST OF THE CWA THROUGH THE REST OF THE MORNING...SO
FREEZING DRIZZLE THREAT IS MINIMAL. I CANT JUSTIFY A WINTER
WEATHER ADVISORY JUST FOR FREEZING FOG...BUT FELT THE NEED TO KEEP
A SPS OUT TO COVER FREEZING FOG POTENTIAL. WILL MONITOR OVER THE
NEXT HOUR AND IF FOG CONTINUES TO INCREASE IN COVERAGE I MAY NEED
TO ISSUE DENSE FOG ADVISORY FOR THE MORNING HOURS.
&&
.SHORT TERM...(THIS MORNING THROUGH SATURDAY NIGHT)
ISSUED AT 244 AM MST THU DEC 18 2014
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW SHORTWAVE
TROUGH OVER NORTHCENTRAL KANSAS WITH AREA OF SUBSIDENCE ALONG
SHORTWAVE RIDGE AXIS BUILDING INTO THE NEBRASKA PANHANDLE. AT THE
SURFACE A STATIONARY FRONT REMAINS IN PLACE OVER EASTERN COLORADO
WITH SOUTH TO SOUTHEAST FLOW IN PLACE ACROSS OUR CWA.
REGARDING WINTER WEATHER ADVISORY EARLY THIS MORNING....
RADAR AND SURROUNDING OBS SHOW A BAND OF LIGHT SNOW THAT FORMED ON
BACK SIDE OF H7 LOW MOVING EAST OVER OUR EASTERN CWA. THIS SNOW HAS
HELPED MIX OUT THE LOW LEVELS OF THE ATMOSPHERE WITH SHIFT IN LOW
LEVEL FLOW TO THE NORTHWEST AIDING IMPROVEMENT IN CONDITIONS
ACROSS THE WESTERN FORECAST AREA. BASED ON SHORT RANGE MODELS...I
AM STILL CONCERNED THAT LIGHT WINDS AND SHALLOW LOW LEVEL MOISTURE
COULD LEAD TO FREEZING FOG REDEVELOPMENT BEHIND THIS SNOW BAND.
FREEZING FOG/DRIZZLE WILL REMAIN POSSIBLE AHEAD OF IT WITH BETTER
MOISTURE ADVECTION/POOLING. OVERALL TREND THROUGH THE MORNING
SHOULD BE IMPROVEMENT IN CONDITIONS AROUND 12-15Z...WITH ANY FOG
CLEARING BY MIDDAY. AFTER 12Z I AM SKEPTICAL THAT FLOW WOULD ALLOW
FOR ENOUGH ADDITIONAL MOISTURE ADVECTION TO SUPPORT CONTINUED
FREEZING DRIZZLE...THOUGH FOG COULD BE POSSIBLE THROUGH MOST OF
THE MORNING ESPECIALLY IN THE EAST WHERE SOUTHERLY FLOW MAY LINGER
A LITTLE LONGER. WITH THIS IN MIND I PLAN ON HOLDING ONTO CURRENT
WINTER WEATHER ADVISORY THROUGH EXPIRATION IN CASE I NEED TO
EXTEND IT IN TIME FOR EASTERN LOCATIONS THROUGH 15Z.
REST OF TODAY...SHORTWAVE RIDGING WILL CONTINUE TO BUILD EAST
TODAY AND AIR MASS WILL BEING MODERATING AND DRYING AS SURFACE
TROUGH SHIFTS EAST. THERE MAYBE DECENT CLEARING WHICH COULD
SUPPORT TEMPS IN THE LOWER 40S (FOR LOCATIONS WITHOUT SNOW PACK).
IT IS TOUGH TO SAY HOW MUCH CLEARING AS MODELS HOLD ONTO STRATUS
OVER PARTS OF THE AREA INTO THE AFTERNOON. NOT A LOT OF
CONFIDENCE IN TEMPS...SO MADE MINOR ADJUSTMENT TO TODAYS HIGHS.
TONIGHT-SATURDAY NIGHT...A SHORTWAVE TROUGH WILL PASS THROUGH THE
SOUTHERN PLAINS THROUGH FRIDAY MORNING...WITH MINIMAL IMPACT ON
SENSIBLE WEATHER OVER OUR CWA. NAM AND SREF BL RH CONTINUE TO RUN
HIGH...LIKELY AS A RESULT OF SNOW PACK...AND SUPPORT FOG/STRATUS
DURING THE OVERNIGHT PERIODS. I ADDED PATCHY FOG TO TONIGHT AS
WINDS WILL BE LIGHT AND THERE COULD BE SOME LINGERING BL MOISTURE
POOLING ALONG AND EAST OF SURFACE TROUGH...THOUGH CONFIDENCE IS
PRETTY LOW AS TROUGH MAY BE EAST OF OUR CWA. THOUGH TEMPS WILL BE
SUBFREEZING...CONFIDENCE IS TOO LOW THAT ANY FOG WOULD BE DENSE
ENOUGH TO WORRY ABOUT ICE ACCUMULATION (FREEZING FOG). I AM
LEAVING FOG OUT OF FRIDAY NIGHT AND SATURDAY NIGHT TO SEE HOW
THINGS EVOLVE TONIGHT FIRST. SHORTWAVE RIDGE SHOULD BUILD BACK
OVER THE PLAINS FRIDAY THROUGH SATURDAY...WITH CONTINUED
MODERATION OF THE AIR MASS ALOFT. COMPLICATION TO TEMP FORECAST
WILL CONTINUE TO BE IMPACT OF DEEPER SNOW PACK IN OUR NORTHWEST
CWA.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 244 AM MST THU DEC 18 2014
THE LONG TERM PERIOD WILL START OUT WITH SLIGHTLY ABOVE AVERAGE
TEMPERATURES ON SUNDAY WITH WARM SOUTHERLY WINDS KEEPING
TEMPERATURES IN THE MID TO UPPER 40S. THE NEXT WEATHER MAKING
SYSTEM WILL APPROACH THE HIGH PLAINS REGION AS AN UPPER LEVEL TROUGH
AND SURFACE LOW PRESSURE SYSTEM MOVE ACROSS THE NORTHERN PLAINS.
THIS SYSTEM WILL BRING IN COLDER AIR TO THE PLAINS WITH CHANCES FOR
PRECIPITATION STARTING EARLY MONDAY MORNING...MOSTLY FOR EASTERN
COLORADO LOCATIONS.
PRECIPITATION MONDAY WILL BEGIN AS SNOW IN THE MORNING WITH COOLER
TEMPERATURES AT THE LOWER LEVELS...BUT WILL BECOME RAIN IN THE
AFTERNOON WITH HIGH TEMPERATURES REACHING THE MID 40S TO LOWER 50S.
AFTER SUNSET...PRECIPITATION WILL TRANSITION BACK TO SNOW THROUGH
THE OVERNIGHT HOURS. UNDER AN INCH OF SNOW IS POSSIBLE WITH THIS
SYSTEM.
THE UPPER LEVEL LOW IS DEPICTED IN GUIDANCE AS STALLING OVER THE
UPPER MIDWEST STATES...BUT THE TRI STATE AREA WILL BE UNDER THE
INFLUENCE OF STRONG NORTHWEST FLOW TUESDAY AS AN UPPER LEVEL RIDGE
BUILDS IN THE WEST. THE HIGHER AMPLITUDE RIDGE WILL BREAK DOWN AND
MOVE WESTWARD TO BRING A SHORTWAVE RIDGE OF HIGH PRESSURE OVER THE
CENTRAL PLAINS TO BRING DRY CONDITIONS AND NEAR AVERAGE TEMPERATURES
FOR TUESDAY AND WEDNESDAY. HIGH TEMPERATURES WILL RANGE FROM THE
UPPER 30S TO MID 40S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 439 AM MST THU DEC 18 2014
LINGER LOW LEVEL MOISTURE HAS SUPPORTED FREEZING FOG REDEVELOPMENT
ACROSS NW KANSAS WHICH IS SPREADING INTO EASTERN COLORADO AND
SOUTHWEST NEBRASKA. VLIFR CONDITIONS ARE ALREADY IN PLACE AT
KGLD...AND CONDITIONS SHOULD DETERIORATE AT KMCK OVER THE NEXT
HOUR. VLIFR CONDITIONS SHOULD EVENTUALLY TRANSITION TO MVFR AND
THEN VFR BY LATE MORNING AS MAIN MOISTURE AXIS SHIFTS EAST. THERE
IS A POSSIBILITY THAT LOW STRATUS MAY LINGER THROUGH THE AFTERNOON
AND FOG/STRATUS POSSIBLY REDEVELOP LATER TONIGHT. HOWEVER...MODEL
DATA MAY BE OVERLY INFLUENCED BY LINGERING SNOW PACK...SO I KEPT
CONDITIONS VFR AFTER MIDDAY FOR BOTH TAFS. WINDS SHOULD REMAIN
LIGHT AROUND 5KT OR LESS THROUGH THE TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...DR
LONG TERM...MK
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
555 AM MST THU DEC 18 2014
.UPDATE...
ISSUED AT 554 AM MST THU DEC 18 2014
EARLIER UPDATE WAS TO ISSUE DENSE FOG ADVISORY FOR OUR CWA. DENSE
FOG DEVELOPED FROM OAKLEY TO TRIBUNE TO BURLINGTON...BUT HAS BEEN
A BIT MORE VARIABLE ALONG THE KS/CO BORDER. SHORT RANGE GUIDANCE
GENERALLY FAVORS THE WESTERN PART OF THE CWA...THOUGH RAP DOES
SHOW THE PATCH OF FOG NEAR OAKLEY SPREADING A LITTLE BIT MORE TO
THE NORTH AND EAST TOWARD GRAHAM COUNTY. I AM NOT AS SURE ABOUT
HRRR WHICH ACTUALLY SHOWED FOG EXPANDING FROM THE COLORADO BORDER
TO THE EAST AND LINGERING THROUGH THE AFTERNOON. HIGHER SURFACE TD
VALUES ARE IN OUR EAST AND LIGHT FOG IS IN PLACE. I WOULD NOT BE
SURPRISED IF DENSE FOG COVERAGE INCREASED AND SPREAD EAST AROUND
OR AFTER SUNRISE...SO I DECIDED TO COVER THE ENTIRE AREA FOR THE
ADVISORY.
WHILE CURRENT DENSE FOG COVERAGE IS SOMEWHAT PATCHY...ROAD
CONDITIONS AFTER YESTERDAYS FREEZING DRIZZLE AND LAST NIGHTS LIGHT
SNOW ARE IN POOR CONDITION ACROSS MANY LOCATIONS. EVEN PATCHY
DENSE FOG WITH THESE ROAD CONDITIONS WOULD MAKE TRAVEL DANGEROUS.
I FELT MORE COMFORTABLE WITH A DENSE FOG ADVISORY THAN SPS DESPITE
THE VARIABLE NATURE OF THE CONDITIONS SO FAR THIS MORNING.
UPDATE ISSUED AT 412 AM MST THU DEC 18 2014
UPDATE TO CANCEL WINTER WEATHER ADVISORY. SNOW BAND HAS FALLEN
APART AND FREEZING DRIZZLE HAS COME TO AN END. UPPER LOW IS NOW
OVER NORTHEAST KS/SOUTHEAST NE. WHILE GOOD LOW LEVEL MOISTURE IS
SUPPORTING DENSE FOG REDEVELOPMENT...BETTER MOISTURE ADVECTION
WILL REMAIN EAST OF THE CWA THROUGH THE REST OF THE MORNING...SO
FREEZING DRIZZLE THREAT IS MINIMAL. I CANT JUSTIFY A WINTER
WEATHER ADVISORY JUST FOR FREEZING FOG...BUT FELT THE NEED TO KEEP
A SPS OUT TO COVER FREEZING FOG POTENTIAL. WILL MONITOR OVER THE
NEXT HOUR AND IF FOG CONTINUES TO INCREASE IN COVERAGE I MAY NEED
TO ISSUE DENSE FOG ADVISORY FOR THE MORNING HOURS.
&&
.SHORT TERM...(THIS MORNING THROUGH SATURDAY NIGHT)
ISSUED AT 244 AM MST THU DEC 18 2014
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW SHORTWAVE
TROUGH OVER NORTHCENTRAL KANSAS WITH AREA OF SUBSIDENCE ALONG
SHORTWAVE RIDGE AXIS BUILDING INTO THE NEBRASKA PANHANDLE. AT THE
SURFACE A STATIONARY FRONT REMAINS IN PLACE OVER EASTERN COLORADO
WITH SOUTH TO SOUTHEAST FLOW IN PLACE ACROSS OUR CWA.
REGARDING WINTER WEATHER ADVISORY EARLY THIS MORNING....
RADAR AND SURROUNDING OBS SHOW A BAND OF LIGHT SNOW THAT FORMED ON
BACK SIDE OF H7 LOW MOVING EAST OVER OUR EASTERN CWA. THIS SNOW HAS
HELPED MIX OUT THE LOW LEVELS OF THE ATMOSPHERE WITH SHIFT IN LOW
LEVEL FLOW TO THE NORTHWEST AIDING IMPROVEMENT IN CONDITIONS
ACROSS THE WESTERN FORECAST AREA. BASED ON SHORT RANGE MODELS...I
AM STILL CONCERNED THAT LIGHT WINDS AND SHALLOW LOW LEVEL MOISTURE
COULD LEAD TO FREEZING FOG REDEVELOPMENT BEHIND THIS SNOW BAND.
FREEZING FOG/DRIZZLE WILL REMAIN POSSIBLE AHEAD OF IT WITH BETTER
MOISTURE ADVECTION/POOLING. OVERALL TREND THROUGH THE MORNING
SHOULD BE IMPROVEMENT IN CONDITIONS AROUND 12-15Z...WITH ANY FOG
CLEARING BY MIDDAY. AFTER 12Z I AM SKEPTICAL THAT FLOW WOULD ALLOW
FOR ENOUGH ADDITIONAL MOISTURE ADVECTION TO SUPPORT CONTINUED
FREEZING DRIZZLE...THOUGH FOG COULD BE POSSIBLE THROUGH MOST OF
THE MORNING ESPECIALLY IN THE EAST WHERE SOUTHERLY FLOW MAY LINGER
A LITTLE LONGER. WITH THIS IN MIND I PLAN ON HOLDING ONTO CURRENT
WINTER WEATHER ADVISORY THROUGH EXPIRATION IN CASE I NEED TO
EXTEND IT IN TIME FOR EASTERN LOCATIONS THROUGH 15Z.
REST OF TODAY...SHORTWAVE RIDGING WILL CONTINUE TO BUILD EAST
TODAY AND AIR MASS WILL BEING MODERATING AND DRYING AS SURFACE
TROUGH SHIFTS EAST. THERE MAYBE DECENT CLEARING WHICH COULD
SUPPORT TEMPS IN THE LOWER 40S (FOR LOCATIONS WITHOUT SNOW PACK).
IT IS TOUGH TO SAY HOW MUCH CLEARING AS MODELS HOLD ONTO STRATUS
OVER PARTS OF THE AREA INTO THE AFTERNOON. NOT A LOT OF
CONFIDENCE IN TEMPS...SO MADE MINOR ADJUSTMENT TO TODAYS HIGHS.
TONIGHT-SATURDAY NIGHT...A SHORTWAVE TROUGH WILL PASS THROUGH THE
SOUTHERN PLAINS THROUGH FRIDAY MORNING...WITH MINIMAL IMPACT ON
SENSIBLE WEATHER OVER OUR CWA. NAM AND SREF BL RH CONTINUE TO RUN
HIGH...LIKELY AS A RESULT OF SNOW PACK...AND SUPPORT FOG/STRATUS
DURING THE OVERNIGHT PERIODS. I ADDED PATCHY FOG TO TONIGHT AS
WINDS WILL BE LIGHT AND THERE COULD BE SOME LINGERING BL MOISTURE
POOLING ALONG AND EAST OF SURFACE TROUGH...THOUGH CONFIDENCE IS
PRETTY LOW AS TROUGH MAY BE EAST OF OUR CWA. THOUGH TEMPS WILL BE
SUBFREEZING...CONFIDENCE IS TOO LOW THAT ANY FOG WOULD BE DENSE
ENOUGH TO WORRY ABOUT ICE ACCUMULATION (FREEZING FOG). I AM
LEAVING FOG OUT OF FRIDAY NIGHT AND SATURDAY NIGHT TO SEE HOW
THINGS EVOLVE TONIGHT FIRST. SHORTWAVE RIDGE SHOULD BUILD BACK
OVER THE PLAINS FRIDAY THROUGH SATURDAY...WITH CONTINUED
MODERATION OF THE AIR MASS ALOFT. COMPLICATION TO TEMP FORECAST
WILL CONTINUE TO BE IMPACT OF DEEPER SNOW PACK IN OUR NORTHWEST
CWA.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 244 AM MST THU DEC 18 2014
THE LONG TERM PERIOD WILL START OUT WITH SLIGHTLY ABOVE AVERAGE
TEMPERATURES ON SUNDAY WITH WARM SOUTHERLY WINDS KEEPING
TEMPERATURES IN THE MID TO UPPER 40S. THE NEXT WEATHER MAKING
SYSTEM WILL APPROACH THE HIGH PLAINS REGION AS AN UPPER LEVEL TROUGH
AND SURFACE LOW PRESSURE SYSTEM MOVE ACROSS THE NORTHERN PLAINS.
THIS SYSTEM WILL BRING IN COLDER AIR TO THE PLAINS WITH CHANCES FOR
PRECIPITATION STARTING EARLY MONDAY MORNING...MOSTLY FOR EASTERN
COLORADO LOCATIONS.
PRECIPITATION MONDAY WILL BEGIN AS SNOW IN THE MORNING WITH COOLER
TEMPERATURES AT THE LOWER LEVELS...BUT WILL BECOME RAIN IN THE
AFTERNOON WITH HIGH TEMPERATURES REACHING THE MID 40S TO LOWER 50S.
AFTER SUNSET...PRECIPITATION WILL TRANSITION BACK TO SNOW THROUGH
THE OVERNIGHT HOURS. UNDER AN INCH OF SNOW IS POSSIBLE WITH THIS
SYSTEM.
THE UPPER LEVEL LOW IS DEPICTED IN GUIDANCE AS STALLING OVER THE
UPPER MIDWEST STATES...BUT THE TRI STATE AREA WILL BE UNDER THE
INFLUENCE OF STRONG NORTHWEST FLOW TUESDAY AS AN UPPER LEVEL RIDGE
BUILDS IN THE WEST. THE HIGHER AMPLITUDE RIDGE WILL BREAK DOWN AND
MOVE WESTWARD TO BRING A SHORTWAVE RIDGE OF HIGH PRESSURE OVER THE
CENTRAL PLAINS TO BRING DRY CONDITIONS AND NEAR AVERAGE TEMPERATURES
FOR TUESDAY AND WEDNESDAY. HIGH TEMPERATURES WILL RANGE FROM THE
UPPER 30S TO MID 40S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 439 AM MST THU DEC 18 2014
LINGER LOW LEVEL MOISTURE HAS SUPPORTED FREEZING FOG REDEVELOPMENT
ACROSS NW KANSAS WHICH IS SPREADING INTO EASTERN COLORADO AND
SOUTHWEST NEBRASKA. VLIFR CONDITIONS ARE ALREADY IN PLACE AT
KGLD...AND CONDITIONS SHOULD DETERIORATE AT KMCK OVER THE NEXT
HOUR. VLIFR CONDITIONS SHOULD EVENTUALLY TRANSITION TO MVFR AND
THEN VFR BY LATE MORNING AS MAIN MOISTURE AXIS SHIFTS EAST. THERE
IS A POSSIBILITY THAT LOW STRATUS MAY LINGER THROUGH THE AFTERNOON
AND FOG/STRATUS POSSIBLY REDEVELOP LATER TONIGHT. HOWEVER...MODEL
DATA MAY BE OVERLY INFLUENCED BY LINGERING SNOW PACK...SO I KEPT
CONDITIONS VFR AFTER MIDDAY FOR BOTH TAFS. WINDS SHOULD REMAIN
LIGHT AROUND 5KT OR LESS THROUGH THE TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...DENSE FOG ADVISORY UNTIL 9 AM MST /10 AM CST/ THIS MORNING FOR
KSZ001>004-013>016-027>029-041-042.
CO...DENSE FOG ADVISORY UNTIL 9 AM MST THIS MORNING FOR COZ090>092.
NE...DENSE FOG ADVISORY UNTIL 9 AM MST /10 AM CST/ THIS MORNING FOR
NEZ079>081.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...MK
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
439 AM MST THU DEC 18 2014
.UPDATE...
ISSUED AT 412 AM MST THU DEC 18 2014
UPDATE TO CANCEL WINTER WEATHER ADVISORY. SNOW BAND HAS FALLEN
APART AND FREEZING DRIZZLE HAS COME TO AN END. UPPER LOW IS NOW
OVER NORTHEAST KS/SOUTHEAST NE. WHILE GOOD LOW LEVEL MOISTURE IS
SUPPORTING DENSE FOG REDEVELOPMENT...BETTER MOISTURE ADVECTION
WILL REMAIN EAST OF THE CWA THROUGH THE REST OF THE MORNING...SO
FREEZING DRIZZLE THREAT IS MINIMAL. I CANT JUSTIFY A WINTER
WEATHER ADVISORY JUST FOR FREEZING FOG...BUT FELT THE NEED TO KEEP
A SPS OUT TO COVER FREEZING FOG POTENTIAL. WILL MONITOR OVER THE
NEXT HOUR AND IF FOG CONTINUES TO INCREASE IN COVERAGE I MAY NEED
TO ISSUE DENSE FOG ADVISORY FOR THE MORNING HOURS.
&&
.SHORT TERM...(THIS MORNING THROUGH SATURDAY NIGHT)
ISSUED AT 244 AM MST THU DEC 18 2014
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW SHORTWAVE
TROUGH OVER NORTHCENTRAL KANSAS WITH AREA OF SUBSIDENCE ALONG
SHORTWAVE RIDGE AXIS BUILDING INTO THE NEBRASKA PANHANDLE. AT THE
SURFACE A STATIONARY FRONT REMAINS IN PLACE OVER EASTERN COLORADO
WITH SOUTH TO SOUTHEAST FLOW IN PLACE ACROSS OUR CWA.
REGARDING WINTER WEATHER ADVISORY EARLY THIS MORNING....
RADAR AND SURROUNDING OBS SHOW A BAND OF LIGHT SNOW THAT FORMED ON
BACK SIDE OF H7 LOW MOVING EAST OVER OUR EASTERN CWA. THIS SNOW HAS
HELPED MIX OUT THE LOW LEVELS OF THE ATMOSPHERE WITH SHIFT IN LOW
LEVEL FLOW TO THE NORTHWEST AIDING IMPROVEMENT IN CONDITIONS
ACROSS THE WESTERN FORECAST AREA. BASED ON SHORT RANGE MODELS...I
AM STILL CONCERNED THAT LIGHT WINDS AND SHALLOW LOW LEVEL MOISTURE
COULD LEAD TO FREEZING FOG REDEVELOPMENT BEHIND THIS SNOW BAND.
FREEZING FOG/DRIZZLE WILL REMAIN POSSIBLE AHEAD OF IT WITH BETTER
MOISTURE ADVECTION/POOLING. OVERALL TREND THROUGH THE MORNING
SHOULD BE IMPROVEMENT IN CONDITIONS AROUND 12-15Z...WITH ANY FOG
CLEARING BY MIDDAY. AFTER 12Z I AM SKEPTICAL THAT FLOW WOULD ALLOW
FOR ENOUGH ADDITIONAL MOISTURE ADVECTION TO SUPPORT CONTINUED
FREEZING DRIZZLE...THOUGH FOG COULD BE POSSIBLE THROUGH MOST OF
THE MORNING ESPECIALLY IN THE EAST WHERE SOUTHERLY FLOW MAY LINGER
A LITTLE LONGER. WITH THIS IN MIND I PLAN ON HOLDING ONTO CURRENT
WINTER WEATHER ADVISORY THROUGH EXPIRATION IN CASE I NEED TO
EXTEND IT IN TIME FOR EASTERN LOCATIONS THROUGH 15Z.
REST OF TODAY...SHORTWAVE RIDGING WILL CONTINUE TO BUILD EAST
TODAY AND AIR MASS WILL BEING MODERATING AND DRYING AS SURFACE
TROUGH SHIFTS EAST. THERE MAYBE DECENT CLEARING WHICH COULD
SUPPORT TEMPS IN THE LOWER 40S (FOR LOCATIONS WITHOUT SNOW PACK).
IT IS TOUGH TO SAY HOW MUCH CLEARING AS MODELS HOLD ONTO STRATUS
OVER PARTS OF THE AREA INTO THE AFTERNOON. NOT A LOT OF
CONFIDENCE IN TEMPS...SO MADE MINOR ADJUSTMENT TO TODAYS HIGHS.
TONIGHT-SATURDAY NIGHT...A SHORTWAVE TROUGH WILL PASS THROUGH THE
SOUTHERN PLAINS THROUGH FRIDAY MORNING...WITH MINIMAL IMPACT ON
SENSIBLE WEATHER OVER OUR CWA. NAM AND SREF BL RH CONTINUE TO RUN
HIGH...LIKELY AS A RESULT OF SNOW PACK...AND SUPPORT FOG/STRATUS
DURING THE OVERNIGHT PERIODS. I ADDED PATCHY FOG TO TONIGHT AS
WINDS WILL BE LIGHT AND THERE COULD BE SOME LINGERING BL MOISTURE
POOLING ALONG AND EAST OF SURFACE TROUGH...THOUGH CONFIDENCE IS
PRETTY LOW AS TROUGH MAY BE EAST OF OUR CWA. THOUGH TEMPS WILL BE
SUBFREEZING...CONFIDENCE IS TOO LOW THAT ANY FOG WOULD BE DENSE
ENOUGH TO WORRY ABOUT ICE ACCUMULATION (FREEZING FOG). I AM
LEAVING FOG OUT OF FRIDAY NIGHT AND SATURDAY NIGHT TO SEE HOW
THINGS EVOLVE TONIGHT FIRST. SHORTWAVE RIDGE SHOULD BUILD BACK
OVER THE PLAINS FRIDAY THROUGH SATURDAY...WITH CONTINUED
MODERATION OF THE AIR MASS ALOFT. COMPLICATION TO TEMP FORECAST
WILL CONTINUE TO BE IMPACT OF DEEPER SNOW PACK IN OUR NORTHWEST
CWA.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 244 AM MST THU DEC 18 2014
THE LONG TERM PERIOD WILL START OUT WITH SLIGHTLY ABOVE AVERAGE
TEMPERATURES ON SUNDAY WITH WARM SOUTHERLY WINDS KEEPING
TEMPERATURES IN THE MID TO UPPER 40S. THE NEXT WEATHER MAKING
SYSTEM WILL APPROACH THE HIGH PLAINS REGION AS AN UPPER LEVEL TROUGH
AND SURFACE LOW PRESSURE SYSTEM MOVE ACROSS THE NORTHERN PLAINS.
THIS SYSTEM WILL BRING IN COLDER AIR TO THE PLAINS WITH CHANCES FOR
PRECIPITATION STARTING EARLY MONDAY MORNING...MOSTLY FOR EASTERN
COLORADO LOCATIONS.
PRECIPITATION MONDAY WILL BEGIN AS SNOW IN THE MORNING WITH COOLER
TEMPERATURES AT THE LOWER LEVELS...BUT WILL BECOME RAIN IN THE
AFTERNOON WITH HIGH TEMPERATURES REACHING THE MID 40S TO LOWER 50S.
AFTER SUNSET...PRECIPITATION WILL TRANSITION BACK TO SNOW THROUGH
THE OVERNIGHT HOURS. UNDER AN INCH OF SNOW IS POSSIBLE WITH THIS
SYSTEM.
THE UPPER LEVEL LOW IS DEPICTED IN GUIDANCE AS STALLING OVER THE
UPPER MIDWEST STATES...BUT THE TRI STATE AREA WILL BE UNDER THE
INFLUENCE OF STRONG NORTHWEST FLOW TUESDAY AS AN UPPER LEVEL RIDGE
BUILDS IN THE WEST. THE HIGHER AMPLITUDE RIDGE WILL BREAK DOWN AND
MOVE WESTWARD TO BRING A SHORTWAVE RIDGE OF HIGH PRESSURE OVER THE
CENTRAL PLAINS TO BRING DRY CONDITIONS AND NEAR AVERAGE TEMPERATURES
FOR TUESDAY AND WEDNESDAY. HIGH TEMPERATURES WILL RANGE FROM THE
UPPER 30S TO MID 40S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 439 AM MST THU DEC 18 2014
LINGER LOW LEVEL MOISTURE HAS SUPPORTED FREEZING FOG REDEVELOPMENT
ACROSS NW KANSAS WHICH IS SPREADING INTO EASTERN COLORADO AND
SOUTHWEST NEBRASKA. VLIFR CONDITIONS ARE ALREADY IN PLACE AT
KGLD...AND CONDITIONS SHOULD DETERIORATE AT KMCK OVER THE NEXT
HOUR. VLIFR CONDITIONS SHOULD EVENTUALLY TRANSITION TO MVFR AND
THEN VFR BY LATE MORNING AS MAIN MOISTURE AXIS SHIFTS EAST. THERE
IS A POSSIBILITY THAT LOW STRATUS MAY LINGER THROUGH THE AFTERNOON
AND FOG/STRATUS POSSIBLY REDEVELOP LATER TONIGHT. HOWEVER...MODEL
DATA MAY BE OVERLY INFLUENCED BY LINGERING SNOW PACK...SO I KEPT
CONDITIONS VFR AFTER MIDDAY FOR BOTH TAFS. WINDS SHOULD REMAIN
LIGHT AROUND 5KT OR LESS THROUGH THE TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...MK
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
413 AM MST THU DEC 18 2014
.UPDATE...
ISSUED AT 412 AM MST THU DEC 18 2014
UPDATE TO CANCEL WINTER WEATHER ADVISORY. SNOW BAND HAS FALLEN
APART AND FREEZING DRIZZLE HAS COME TO AN END. UPPER LOW IS NOW
OVER NORTHEAST KS/SOUTHEAST NE. WHILE GOOD LOW LEVEL MOISTURE IS
SUPPORTING DENSE FOG REDEVELOPMENT...BETTER MOISTURE ADVECTION
WILL REMAIN EAST OF THE CWA THROUGH THE REST OF THE MORNING...SO
FREEZING DRIZZLE THREAT IS MINIMAL. I CANT JUSTIFY A WINTER
WEATHER ADVISORY JUST FOR FREEZING FOG...BUT FELT THE NEED TO KEEP
A SPS OUT TO COVER FREEZING FOG POTENTIAL. WILL MONITOR OVER THE
NEXT HOUR AND IF FOG CONTINUES TO INCREASE IN COVERAGE I MAY NEED
TO ISSUE DENSE FOG ADVISORY FOR THE MORNING HOURS.
&&
.SHORT TERM...(THIS MORNING THROUGH SATURDAY NIGHT)
ISSUED AT 244 AM MST THU DEC 18 2014
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW SHORTWAVE
TROUGH OVER NORTHCENTRAL KANSAS WITH AREA OF SUBSIDENCE ALONG
SHORTWAVE RIDGE AXIS BUILDING INTO THE NEBRASKA PANHANDLE. AT THE
SURFACE A STATIONARY FRONT REMAINS IN PLACE OVER EASTERN COLORADO
WITH SOUTH TO SOUTHEAST FLOW IN PLACE ACROSS OUR CWA.
REGARDING WINTER WEATHER ADVISORY EARLY THIS MORNING....
RADAR AND SURROUNDING OBS SHOW A BAND OF LIGHT SNOW THAT FORMED ON
BACK SIDE OF H7 LOW MOVING EAST OVER OUR EASTERN CWA. THIS SNOW HAS
HELPED MIX OUT THE LOW LEVELS OF THE ATMOSPHERE WITH SHIFT IN LOW
LEVEL FLOW TO THE NORTHWEST AIDING IMPROVEMENT IN CONDITIONS
ACROSS THE WESTERN FORECAST AREA. BASED ON SHORT RANGE MODELS...I
AM STILL CONCERNED THAT LIGHT WINDS AND SHALLOW LOW LEVEL MOISTURE
COULD LEAD TO FREEZING FOG REDEVELOPMENT BEHIND THIS SNOW BAND.
FREEZING FOG/DRIZZLE WILL REMAIN POSSIBLE AHEAD OF IT WITH BETTER
MOISTURE ADVECTION/POOLING. OVERALL TREND THROUGH THE MORNING
SHOULD BE IMPROVEMENT IN CONDITIONS AROUND 12-15Z...WITH ANY FOG
CLEARING BY MIDDAY. AFTER 12Z I AM SKEPTICAL THAT FLOW WOULD ALLOW
FOR ENOUGH ADDITIONAL MOISTURE ADVECTION TO SUPPORT CONTINUED
FREEZING DRIZZLE...THOUGH FOG COULD BE POSSIBLE THROUGH MOST OF
THE MORNING ESPECIALLY IN THE EAST WHERE SOUTHERLY FLOW MAY LINGER
A LITTLE LONGER. WITH THIS IN MIND I PLAN ON HOLDING ONTO CURRENT
WINTER WEATHER ADVISORY THROUGH EXPIRATION IN CASE I NEED TO
EXTEND IT IN TIME FOR EASTERN LOCATIONS THROUGH 15Z.
REST OF TODAY...SHORTWAVE RIDGING WILL CONTINUE TO BUILD EAST
TODAY AND AIR MASS WILL BEING MODERATING AND DRYING AS SURFACE
TROUGH SHIFTS EAST. THERE MAYBE DECENT CLEARING WHICH COULD
SUPPORT TEMPS IN THE LOWER 40S (FOR LOCATIONS WITHOUT SNOW PACK).
IT IS TOUGH TO SAY HOW MUCH CLEARING AS MODELS HOLD ONTO STRATUS
OVER PARTS OF THE AREA INTO THE AFTERNOON. NOT A LOT OF
CONFIDENCE IN TEMPS...SO MADE MINOR ADJUSTMENT TO TODAYS HIGHS.
TONIGHT-SATURDAY NIGHT...A SHORTWAVE TROUGH WILL PASS THROUGH THE
SOUTHERN PLAINS THROUGH FRIDAY MORNING...WITH MINIMAL IMPACT ON
SENSIBLE WEATHER OVER OUR CWA. NAM AND SREF BL RH CONTINUE TO RUN
HIGH...LIKELY AS A RESULT OF SNOW PACK...AND SUPPORT FOG/STRATUS
DURING THE OVERNIGHT PERIODS. I ADDED PATCHY FOG TO TONIGHT AS
WINDS WILL BE LIGHT AND THERE COULD BE SOME LINGERING BL MOISTURE
POOLING ALONG AND EAST OF SURFACE TROUGH...THOUGH CONFIDENCE IS
PRETTY LOW AS TROUGH MAY BE EAST OF OUR CWA. THOUGH TEMPS WILL BE
SUBFREEZING...CONFIDENCE IS TOO LOW THAT ANY FOG WOULD BE DENSE
ENOUGH TO WORRY ABOUT ICE ACCUMULATION (FREEZING FOG). I AM
LEAVING FOG OUT OF FRIDAY NIGHT AND SATURDAY NIGHT TO SEE HOW
THINGS EVOLVE TONIGHT FIRST. SHORTWAVE RIDGE SHOULD BUILD BACK
OVER THE PLAINS FRIDAY THROUGH SATURDAY...WITH CONTINUED
MODERATION OF THE AIR MASS ALOFT. COMPLICATION TO TEMP FORECAST
WILL CONTINUE TO BE IMPACT OF DEEPER SNOW PACK IN OUR NORTHWEST
CWA.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 244 AM MST THU DEC 18 2014
THE LONG TERM PERIOD WILL START OUT WITH SLIGHTLY ABOVE AVERAGE
TEMPERATURES ON SUNDAY WITH WARM SOUTHERLY WINDS KEEPING
TEMPERATURES IN THE MID TO UPPER 40S. THE NEXT WEATHER MAKING
SYSTEM WILL APPROACH THE HIGH PLAINS REGION AS AN UPPER LEVEL TROUGH
AND SURFACE LOW PRESSURE SYSTEM MOVE ACROSS THE NORTHERN PLAINS.
THIS SYSTEM WILL BRING IN COLDER AIR TO THE PLAINS WITH CHANCES FOR
PRECIPITATION STARTING EARLY MONDAY MORNING...MOSTLY FOR EASTERN
COLORADO LOCATIONS.
PRECIPITATION MONDAY WILL BEGIN AS SNOW IN THE MORNING WITH COOLER
TEMPERATURES AT THE LOWER LEVELS...BUT WILL BECOME RAIN IN THE
AFTERNOON WITH HIGH TEMPERATURES REACHING THE MID 40S TO LOWER 50S.
AFTER SUNSET...PRECIPITATION WILL TRANSITION BACK TO SNOW THROUGH
THE OVERNIGHT HOURS. UNDER AN INCH OF SNOW IS POSSIBLE WITH THIS
SYSTEM.
THE UPPER LEVEL LOW IS DEPICTED IN GUIDANCE AS STALLING OVER THE
UPPER MIDWEST STATES...BUT THE TRI STATE AREA WILL BE UNDER THE
INFLUENCE OF STRONG NORTHWEST FLOW TUESDAY AS AN UPPER LEVEL RIDGE
BUILDS IN THE WEST. THE HIGHER AMPLITUDE RIDGE WILL BREAK DOWN AND
MOVE WESTWARD TO BRING A SHORTWAVE RIDGE OF HIGH PRESSURE OVER THE
CENTRAL PLAINS TO BRING DRY CONDITIONS AND NEAR AVERAGE TEMPERATURES
FOR TUESDAY AND WEDNESDAY. HIGH TEMPERATURES WILL RANGE FROM THE
UPPER 30S TO MID 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1033 PM MST WED DEC 17 2014
FOR BOTH TAF SITES FROM 06Z-15Z THURSDAY...MAINLY LIFR/VLIFR
CONDITIONS WITH BRIEF IFR/MVFR MIX THRU 09Z. CEILINGS MAINLY 1/4SM
TO 1/2SM IN A SNOW/FREEZING FOG MIX...WITH PERIODS 1-3SM THRU 09Z.
FROM 15Z ONWARD...IFR CONDITIONS TREND TO VFR BY 00Z FRIDAY.
CEILINGS WILL RANGE FROM BKN-OVC006-010 UP TO BKN100 BY 00Z
FRIDAY. 3-6SM IN FOG DURING THIS TIME...ESPECIALLY BEFORE 00Z
FRIDAY. WINDS MAINLY VARIABLE THRU 15Z...THEN WSW 5-10KTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...MK
AVIATION...JN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
245 AM MST THU DEC 18 2014
.SHORT TERM...(THIS MORNING THROUGH SATURDAY NIGHT)
ISSUED AT 244 AM MST THU DEC 18 2014
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW SHORTWAVE
TROUGH OVER NORTHCENTRAL KANSAS WITH AREA OF SUBSIDENCE ALONG
SHORTWAVE RIDGE AXIS BUILDING INTO THE NEBRASKA PANHANDLE. AT THE
SURFACE A STATIONARY FRONT REMAINS IN PLACE OVER EASTERN COLORADO
WITH SOUTH TO SOUTHEAST FLOW IN PLACE ACROSS OUR CWA.
REGARDING WINTER WEATHER ADVISORY EARLY THIS MORNING....
RADAR AND SURROUNDING OBS SHOW A BAND OF LIGHT SNOW THAT FORMED ON
BACK SIDE OF H7 LOW MOVING EAST OVER OUR EASTERN CWA. THIS SNOW HAS
HELPED MIX OUT THE LOW LEVELS OF THE ATMOSPHERE WITH SHIFT IN LOW
LEVEL FLOW TO THE NORTHWEST AIDING IMPROVEMENT IN CONDITIONS
ACROSS THE WESTERN FORECAST AREA. BASED ON SHORT RANGE MODELS...I
AM STILL CONCERNED THAT LIGHT WINDS AND SHALLOW LOW LEVEL MOISTURE
COULD LEAD TO FREEZING FOG REDEVELOPMENT BEHIND THIS SNOW BAND.
FREEZING FOG/DRIZZLE WILL REMAIN POSSIBLE AHEAD OF IT WITH BETTER
MOISTURE ADVECTION/POOLING. OVERALL TREND THROUGH THE MORNING
SHOULD BE IMPROVEMENT IN CONDITIONS AROUND 12-15Z...WITH ANY FOG
CLEARING BY MIDDAY. AFTER 12Z I AM SKEPTICAL THAT FLOW WOULD ALLOW
FOR ENOUGH ADDITIONAL MOISTURE ADVECTION TO SUPPORT CONTINUED
FREEZING DRIZZLE...THOUGH FOG COULD BE POSSIBLE THROUGH MOST OF
THE MORNING ESPECIALLY IN THE EAST WHERE SOUTHERLY FLOW MAY LINGER
A LITTLE LONGER. WITH THIS IN MIND I PLAN ON HOLDING ONTO CURRENT
WINTER WEATHER ADVISORY THROUGH EXPIRATION IN CASE I NEED TO
EXTEND IT IN TIME FOR EASTERN LOCATIONS THROUGH 15Z.
REST OF TODAY...SHORTWAVE RIDGING WILL CONTINUE TO BUILD EAST
TODAY AND AIR MASS WILL BEING MODERATING AND DRYING AS SURFACE
TROUGH SHIFTS EAST. THERE MAYBE DECENT CLEARING WHICH COULD
SUPPORT TEMPS IN THE LOWER 40S (FOR LOCATIONS WITHOUT SNOW PACK).
IT IS TOUGH TO SAY HOW MUCH CLEARING AS MODELS HOLD ONTO STRATUS
OVER PARTS OF THE AREA INTO THE AFTERNOON. NOT A LOT OF
CONFIDENCE IN TEMPS...SO MADE MINOR ADJUSTMENT TO TODAYS HIGHS.
TONIGHT-SATURDAY NIGHT...A SHORTWAVE TROUGH WILL PASS THROUGH THE
SOUTHERN PLAINS THROUGH FRIDAY MORNING...WITH MINIMAL IMPACT ON
SENSIBLE WEATHER OVER OUR CWA. NAM AND SREF BL RH CONTINUE TO RUN
HIGH...LIKELY AS A RESULT OF SNOW PACK...AND SUPPORT FOG/STRATUS
DURING THE OVERNIGHT PERIODS. I ADDED PATCHY FOG TO TONIGHT AS
WINDS WILL BE LIGHT AND THERE COULD BE SOME LINGERING BL MOISTURE
POOLING ALONG AND EAST OF SURFACE TROUGH...THOUGH CONFIDENCE IS
PRETTY LOW AS TROUGH MAY BE EAST OF OUR CWA. THOUGH TEMPS WILL BE
SUBFREEZING...CONFIDENCE IS TOO LOW THAT ANY FOG WOULD BE DENSE
ENOUGH TO WORRY ABOUT ICE ACCUMULATION (FREEZING FOG). I AM
LEAVING FOG OUT OF FRIDAY NIGHT AND SATURDAY NIGHT TO SEE HOW
THINGS EVOLVE TONIGHT FIRST. SHORTWAVE RIDGE SHOULD BUILD BACK
OVER THE PLAINS FRIDAY THROUGH SATURDAY...WITH CONTINUED
MODERATION OF THE AIR MASS ALOFT. COMPLICATION TO TEMP FORECAST
WILL CONTINUE TO BE IMPACT OF DEEPER SNOW PACK IN OUR NORTHWEST
CWA.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 244 AM MST THU DEC 18 2014
THE LONG TERM PERIOD WILL START OUT WITH SLIGHTLY ABOVE AVERAGE
TEMPERATURES ON SUNDAY WITH WARM SOUTHERLY WINDS KEEPING
TEMPERATURES IN THE MID TO UPPER 40S. THE NEXT WEATHER MAKING
SYSTEM WILL APPROACH THE HIGH PLAINS REGION AS AN UPPER LEVEL TROUGH
AND SURFACE LOW PRESSURE SYSTEM MOVE ACROSS THE NORTHERN PLAINS.
THIS SYSTEM WILL BRING IN COLDER AIR TO THE PLAINS WITH CHANCES FOR
PRECIPITATION STARTING EARLY MONDAY MORNING...MOSTLY FOR EASTERN
COLORADO LOCATIONS.
PRECIPITATION MONDAY WILL BEGIN AS SNOW IN THE MORNING WITH COOLER
TEMPERATURES AT THE LOWER LEVELS...BUT WILL BECOME RAIN IN THE
AFTERNOON WITH HIGH TEMPERATURES REACHING THE MID 40S TO LOWER 50S.
AFTER SUNSET...PRECIPITATION WILL TRANSITION BACK TO SNOW THROUGH
THE OVERNIGHT HOURS. UNDER AN INCH OF SNOW IS POSSIBLE WITH THIS
SYSTEM.
THE UPPER LEVEL LOW IS DEPICTED IN GUIDANCE AS STALLING OVER THE
UPPER MIDWEST STATES...BUT THE TRI STATE AREA WILL BE UNDER THE
INFLUENCE OF STRONG NORTHWEST FLOW TUESDAY AS AN UPPER LEVEL RIDGE
BUILDS IN THE WEST. THE HIGHER AMPLITUDE RIDGE WILL BREAK DOWN AND
MOVE WESTWARD TO BRING A SHORTWAVE RIDGE OF HIGH PRESSURE OVER THE
CENTRAL PLAINS TO BRING DRY CONDITIONS AND NEAR AVERAGE TEMPERATURES
FOR TUESDAY AND WEDNESDAY. HIGH TEMPERATURES WILL RANGE FROM THE
UPPER 30S TO MID 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1033 PM MST WED DEC 17 2014
FOR BOTH TAF SITES FROM 06Z-15Z THURSDAY...MAINLY LIFR/VLIFR
CONDITIONS WITH BRIEF IFR/MVFR MIX THRU 09Z. CEILINGS MAINLY 1/4SM
TO 1/2SM IN A SNOW/FREEZING FOG MIX...WITH PERIODS 1-3SM THRU 09Z.
FROM 15Z ONWARD...IFR CONDITIONS TREND TO VFR BY 00Z FRIDAY.
CEILINGS WILL RANGE FROM BKN-OVC006-010 UP TO BKN100 BY 00Z
FRIDAY. 3-6SM IN FOG DURING THIS TIME...ESPECIALLY BEFORE 00Z
FRIDAY. WINDS MAINLY VARIABLE THRU 15Z...THEN WSW 5-10KTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY UNTIL 5 AM MST /6 AM CST/ EARLY THIS
MORNING FOR KSZ001>004-013>016-027>029-041-042.
CO...WINTER WEATHER ADVISORY UNTIL 5 AM MST EARLY THIS MORNING FOR
COZ090>092.
NE...WINTER WEATHER ADVISORY UNTIL 5 AM MST /6 AM CST/ EARLY THIS
MORNING FOR NEZ079>081.
&&
$$
SHORT TERM...DR
LONG TERM...MK
AVIATION...JN
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
145 PM EST THU DEC 18 2014
.UPDATE...
ISSUED AT 145 PM EST THU DEC 18 2014
DID A QUICK UPDATE TO THE GRIDS TO REMOVE ALL BUT THE SPRINKLE AND
FLURRY CHANCES INTO THE EVENING. ALSO FINE TUNED THE HOURLY T AND TD
GRIDS PER THE LATEST OBS AND TRENDS...ALONG WITH THE MAXT GRID. THESE
HAVE BEEN SENT TO THE NDFD AND WEB SERVERS ALONG WITH FRESH ISSUANCES
OF THE HWO AND ZFP.
UPDATE ISSUED AT 1025 AM EST THU DEC 18 2014
14Z SFC ANALYSIS SHOWS A VERY WEAK AREA OF LOW PRESSURE SLIDING BY TO
THE SOUTH OF EASTERN KENTUCKY. THE PRECIPITATION WITH THIS...MAINLY
FLURRIES...IS FADING FAST WITH MOSTLY VIRGA LEFT. TEMPERATURES ARE
GENERALLY IN IN THE UPPER 20S AND LOWER 30S THROUGH THE AREA WITH
DEWPOINTS IN THE MID AND UPPER 20S...WHILE WINDS ARE LIGHT. SATELLITE
SHOWS A FEW BREAKS OUT THERE BUT CIGS ARE MAINLY IN THE LOW MVFR
RANGE NORTH AND VFR SOUTH. HAVE UPDATED THE FORECAST TO DIMINISH THE
POPS QUICKLY THROUGH MIDDAY IN CONJUNCTION WITH THE 12Z NAM12 AND
LATEST HRRR. ALSO FINE TUNED HIGH TEMPERATURES AND THE HOURLY T/TD
GRIDS PER THE LATEST OBS...TRENDS...AND CONSSHORT GUIDANCE. THESE
HAVE BEEN SENT TO THE NDFD AND WEB SERVERS ALONG WITH AN UPDATE TO
THE HWO AND ZONES.
UPDATE ISSUED AT 552 AM EST THU DEC 18 2014
THERE IS A FAIR AMOUNT OF RADAR RETURNS MAKING IT INTO SOUTHEAST
KY...UNLIKE WHAT MANY OF THE HI RES MODELS WERE SHOWING EARLIER.
DESPITE THE DRY AIR IN PLACE AT THE SURFACE...DEW POINT DEPRESSIONS
HAVE LESSENED TO 0 IN SOME OF OUR SOUTHWESTERN COUNTIES. AND WITH
SNOW AND SLEET BEING REPORTED ONLY A FEW COUNTIES OVER...DECIDED IT
WAS TIME TO GO AHEAD AND EXPAND THE CHANCES FOR PRECIP THIS MORNING.
AS IT IS NOW...IT LOOKS LIKE ALL OF THE COUNTIES ALONG THE TENNESSEE
BORDER...AS WELL AS THE NEXT TIER OF COUNTIES NORTHWARD WILL LIKELY
BE AFFECTED BY LIGHT SNOW AND POTENTIAL SLEET THIS MORNING. LATEST HI
RES MODELS...INCLUDING THE HRRR AND NAM 12 ARE SHOWING THE SYSTEM
LOSING INTENSITY VERY QUICKLY THIS MORNING...AND CUTTING OFF PRECIP
CHANCES ACROSS OUR CWA WITHIN THE NEXT FEW HOURS. HOWEVER...GIVEN THE
LEVEL OF UNCERTAINTY...AND THE ONGOING STRONG REFLECTIVITIES...ERRED
ON THE PESSIMISTIC SIDE AND KEPT MENTION OF SNOW AND ICE IN UNTIL MID
MORNING. ALSO...WENT AHEAD AND ISSUED A SPECIAL WEATHER STATEMENT
THROUGH 15Z FOR THE AFFECTED COUNTIES SINCE ANY PRECIP WILL LIKELY
ACCUMULATE ON SURFACES DURING THE MORNING COMMUTE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 358 AM EST THU DEC 18 2014
SURFACE HIGH PRESSURE CONTINUES TO BE IN CHARGE FOR THE OHIO RIVER
VALLEY AND MANY POINTS TO OUR NORTH AND SOUTH. STRONG SUBSIDENCE
TRAPPING LOW LEVEL MOISTURE ACROSS THE NE PORTION OF THE CWA HAS LED
TO CONTINUED MVFR CLOUDS...WHICH ACCORDING TO THE LATEST FORECAST
SOUNDINGS...SHOULDN/T BE BUDGING UNTIL SOMETIME EARLY THIS
AFTERNOON. MEANWHILE...ALOFT...A SHORTWAVE IS CONTINUING TO DAMPEN
AS IT TRACKS EASTWARD...AND SHOULD BE POISED TO REACH THE
MISSISSIPPI RIVER VALLEY BETWEEN 12 AND 18Z TODAY. SO FAR...THIS
SYSTEM HAS BROUGHT LIGHT PRECIP ACROSS FAR SW KY...AS IT CONTINUES
TO SHIFT EASTWARD TOWARDS OUR SW CWA DURING THE EARLY MORNING HOURS.
THE AMOUNT OF LOW LEVEL DRY AIR IS STILL A CONCERN IN THIS AREA OF
THE CWA...AND WHETHER OR NOT THE PRECIP CAN OVERCOME IT. EXPECTING
BEST CHANCES FOR WEATHER ACROSS WAYNE AND MCCREARY COUNTIES GIVEN
THE LATEST HI RES MODEL DATA...INCLUDING THE HRRR AND ECMWF.
FORECAST SOUNDINGS ARE SHOWING BELOW FREEZING SURFACE TEMPS AT THESE
LOCATIONS...BUT WITH THE POTENTIAL FOR A SLIGHT WARM NOSE TEETERING
ALONG THE FREEZING LINE SEVERAL THOUSAND FEET ABOVE GROUND THROUGH
18Z. AS SUCH...WENT AHEAD AND MENTIONED SOME ICE PELLETS ALONG WITH
A CHANCE OF SNOW IN THESE TWO COUNTIES...WITH A SLIGHT CHANCE OF
LIGHT SNOW EVENTUALLY MIXING WITH RAIN AFTERWARDS ELSEWHERE IN THE
SW CWA.
THE SHORTWAVE WILL EVENTUALLY FLATTEN AND SHIFT EAST OF KY BY 06Z
FRIDAY ELIMINATING ANY FURTHER PRECIP CONCERNS FOR THE SHORT TERM.
THE ONE CAVEAT WILL BE THE EXISTENCE OF THE MID LEVEL CLOUDS WITH
MUCH OF THE TEMPERATURE PROFILE /INCLUDING SURFACE TEMPS/ DROPPING
BELOW FREEZING BY THIS EVENING AND THROUGHOUT THE OVERNIGHT. A FEW
FLURRIES MAY GET SQUEEZED OUT ACROSS THE CWA DURING THE EVENING. IN
FACT...MAY NOT HAVE EXTENDED THE FLURRY POTENTIAL FAR ENOUGH ACROSS
THE CWA. BUT THE CONFIDENCE IS STILL QUITE LOW ON THIS SUBJECT.
CONTINUED TO GO ABOVE GUIDANCE FOR CLOUD COVER OVER THE NEXT 36
HOURS AS MID/LOW LEVEL CLOUDS LOOK TO STICK AROUND THROUGH
FRIDAY...BEFORE ANOTHER ROUND OF HIGH CLOUDS WORKS INTO THE CWA.
THIS MAY INHIBIT SOME OF THE BEST RIDGE VALLEY SPLIT POTENTIAL
TONIGHT. OVERALL...TEMPERATURES SHOULD/T DEVIATE MUCH FROM WHAT WAS
SEEN IN THE PREVIOUS 24 HOURS. HIGHS TODAY WILL GENERALLY BE IN THE
UPPER 30S AND LOW 40S...WITH OVERNIGHT LOWS TONIGHT DROPPING DOWN
INTO THE UPPER 20S. WINDS AT THE SURFACE WILL REMAIN QUITE LIGHT AND
VARIABLE THROUGH THE SHORT TERM...WHILE ABOVE THE CONTINUED MID
LEVEL SUBSIDENCE INVERSION...THEY WILL INCREASE RAPIDLY THANKS TO A
WEST TO EAST ORIENTED JET STREAK WHICH IS CURRENTLY PUSHING ALONG
AND SOUTH OF KY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 358 AM EST THU DEC 18 2014
A FAIRLY ACTIVE PATTERN IN STORE FOR THE EXTENDED PORTION OF THE
FORECAST. THE MODELS AREA IN PRETTY GOOD AGREEMENT WITH THE LARGE
SCALE UPPER LEVEL FLOW PATTERN THROUGH MID WEEK. THREE SYSTEMS ARE
FORECAST TO AFFECT EASTERN KENTUCKY...THE FIRST BEING A WEAK AREA OF
LOW PRESSURE THAT IS FORECAST TO FORM OVER THE SOUTHERN PLAINS AND
THEN PROGRESS EASTWARD ACROSS THE GULF COAST FRIDAY NIGHT THROUGH
SATURDAY NIGHT. THE SECOND AND THIRD WEATHER SYSTEMS TO AFFECT THE
REGION...SHOULD THE MODELS PAN OUT...WOULD COME MONDAY THROUGH
WEDNESDAY OF NEXT WEEK. THE FIRST OF THESE LATE PERIOD SYSTEMS IS
PROGGED TO ORIGINATE OVER THE GULF OF MEXICO AND MOVE UP THE EASTERN
SLOPES OF THE APPALACHIAN MOUNTAINS MONDAY AND MONDAY NIGHT. THE
SECOND WEATHER SYSTEM IN THIS SCENARIO IS FORECAST TO TAKE SHAPE
OVER THE NORTHERN PLAINS TO BEGIN THE NEW WORK WEEK. THIS SECOND
SYSTEM WOULD COME IN THE FORM OF A LARGE SCALE AND MUCH DEEPER
TROUGH THAN EITHER OF THE SOUTHERN STREAM SYSTEMS. THIS AREA OF LOW
PRESSURE WOULD PROVIDE THE SOURCE OF COLD AIR THAT COULD BRING SUB
FREEZING TEMPERATURES AND SNOW NEXT WEDNESDAY NIGHT.
THE UNCERTAINTY WITH THIS WEEKENDS WEATHER WILL REVOLVE AROUND HOW
MUCH COLD AIR WILL BE ABLE TO FILTER INTO THE AREA AS THE SOUTHERN
PLAINS LOW MAKES ITS NORTHEASTERN TURN FRIDAY NIGHT. BASED ON THE
LATEST MODEL SOUNDINGS AND TIME HEIGHTS...THERE IS SOME UNCERTAINTY
AS TO HOW FAR SOUTH THE COLD AIR WILL PENETRATE FRIDAY NIGHT INTO
SATURDAY MORNING. BASED ON THIS...DECIDED TO CONFINE ANY
ACCUMULATING SNOW TO THE AREA NORTH OF THE MOUNTAIN PARKWAY BETWEEN
6 AND 12Z FRIDAY NIGHT. THE SNOW SHOULD THEN TRANSITION TO A RAIN
SNOW MIX EARLY SATURDAY MORNING...AND THEN TO ALL RAIN BY EARLY
SATURDAY AFTERNOON. ANY SNOW ACCUMULATIONS THAT DO OCCUR WOULD
LIKELY BE CONFINED TO GRASSY AREAS AND ELEVATED SURFACES. OUR FAR
EASTERN COUNTIES COULD SEE ANOTHER SHOT OF RAIN SNOW MIX OR ALL SNOW
FOR A BRIEF PERIOD SATURDAY NIGHT AS THE LOW EXITS THE AREA AND
WINDS SHIFT TO THE NORTH NORTHEAST. A WEAK RIDGE OF HIGH PRESSURE
ALOFT SHOULD PROVIDE A BRIEF RESPITE FROM THE WINTRY WEATHER LATE
SATURDAY NIGHT THROUGH MID MORNING ON SUNDAY. THE MODELS ONCE AGAIN
OFFER UP SOME UNCERTAINTY AS TO EXACTLY WHEN PRECIPITATION ONSET
WILL BE ON SUNDAY...WITH THE GFS MODEL HOLDING OFF A LOT LONGER THAN
THE ECMWF. BASED ON THIS...WENT WITH A BLEND BETWEEN THE TWO MODELS
FOR PRECIP ONSET ON SUNDAY ACROSS OUR EASTERN COUNTIES...WITH LIGHT
RAIN AFFECTING THE SOUTHEASTERN TWO THIRDS OF THE AREA AS MOISTURE
FROM THE GULF LOW BEGINS TO MOVE NORTHWARD INTO THE AREA. THE BETTER
SHOT OF PRECIPITATION WILL COME FROM MONDAY NIGHT THROUGH WEDNESDAY
EVENING...AS A MUCH STRONGER AND WETTER WEATHER SYSTEM DIVES OUT OF
THE NORTHERN PLAINS AND PHASES WITH WHAT EVER ENERGY IS LEFT OVER
FROM THE GULF OF MEXICO WEATHER SYSTEM. MOST OF THE PRECIPITATION
WITH THIS THIRD WEATHER SYSTEM LOOKS TO BE IN THE FORM OF RAIN BASED
ON THE TEMPERATURE PROFILES SEEN IN THE LATEST MODEL DATA. COULD SEE
SOME MORE SNOW WITH THIS FINAL WEATHER SYSTEM AS WINDS SHIFT TO THE
WEST AND NORTHWEST BEHIND THE LOW AS IT MOVES INTO NEW ENGLAND AND
COLDER AIR SPILLS INTO THE REGION.
THE OTHER WEATHER CONCERN OF NOTE FOR THE END OF THE EXTENDED PERIOD
WILL BE WINDS...PARTICULARLY FROM WEDNESDAY ONWARD. THE MODELS ALL
AGREE THAT A WELL DEVELOPED PRESSURE GRADIENT WILL ACCOMPANY THE
GREAT PLAINS WEATHER SYSTEM AS IT MOVES EAST. SUSTAINED WEST TO
NORTHWEST WINDS OF 10 TO 15 MPH...WITH GUSTS OF 20 TO 25 MPH...WILL
NOT BE OUT OF THE QUESTION. TEMPERATURES THROUGHOUT THE EXTENDED
PERIOD LOOK TO BE AT OR SLIGHTLY ABOVE NORMAL FROM SUNDAY THROUGH
WEDNESDAY. THE WARMEST STRETCH DURING THAT TIME WOULD BE MONDAY AND
TUESDAY...AS WINDS SHIFT TO THE SOUTH AHEAD OF THE MID WEEK WEATHER
SYSTEM. HIGHS ON EACH OF THOSE DAYS ARE EXPECTED TO TOP OUT IN THE
UPPER 40S AND LOWER 50S RESPECTIVELY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 125 PM EST THU DEC 18 2014
SURFACE HIGH PRESSURE HAS BASICALLY WON OUT OVER THE AREA...
EVAPORATING ALL THE LIGHT RADAR RETURNS BEFORE THEY REACH THE GROUND.
THE LOWER CLOUDS ACROSS THE NORTH ARE EXPECTED TO BREAK UP DURING THE
AFTERNOON WHILE HIGH AND MID ONES REMAIN. CANNOT RULE OUT AN ODD
FLURRY OR SPRINKLE THROUGH THE EVENING...BUT MOST LOCATIONS WILL
REMAIN PCPN FREE. THE VFR CIGS WILL LOWER TONIGHT INTO FRIDAY MORNING
BUT THERE SHOULDN/T BE ANY RESTRICTIONS. EVEN THESE CLOUDS WILL
LIKELY BREAK UP DURING THE DAY FRIDAY KEEPING CONDITIONS VFR. WINDS
THROUGH THE PERIOD WILL BE LIGHT AND MAINLY FROM THE NORTHWEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...JMW
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1025 AM EST THU DEC 18 2014
.UPDATE...
ISSUED AT 1025 AM EST THU DEC 18 2014
14Z SFC ANALYSIS SHOWS A VERY WEAK AREA OF LOW PRESSURE SLIDING BY TO
THE SOUTH OF EASTERN KENTUCKY. THE PRECIPITATION WITH THIS...MAINLY
FLURRIES...IS FADING FAST WITH MOSTLY VIRGA LEFT. TEMPERATURES ARE
GENERALLY IN IN THE UPPER 20S AND LOWER 30S THROUGH THE AREA WITH
DEWPOINTS IN THE MID AND UPPER 20S...WHILE WINDS ARE LIGHT. SATELLITE
SHOWS A FEW BREAKS OUT THERE BUT CIGS ARE MAINLY IN THE LOW MVFR
RANGE NORTH AND VFR SOUTH. HAVE UPDATED THE FORECAST TO DIMINISH THE
POPS QUICKLY THROUGH MIDDAY IN CONJUNCTION WITH THE 12Z NAM12 AND
LATEST HRRR. ALSO FINE TUNED HIGH TEMPERATURES AND THE HOURLY T/TD
GRIDS PER THE LATEST OBS...TRENDS...AND CONSSHORT GUIDANCE. THESE
HAVE BEEN SENT TO THE NDFD AND WEB SERVERS ALONG WITH AN UPDATE TO
THE HWO AND ZONES.
UPDATE ISSUED AT 552 AM EST THU DEC 18 2014
THERE IS A FAIR AMOUNT OF RADAR RETURNS MAKING IT INTO SOUTHEAST
KY...UNLIKE WHAT MANY OF THE HI RES MODELS WERE SHOWING EARLIER.
DESPITE THE DRY AIR IN PLACE AT THE SURFACE...DEW POINT DEPRESSIONS
HAVE LESSENED TO 0 IN SOME OF OUR SOUTHWESTERN COUNTIES. AND WITH
SNOW AND SLEET BEING REPORTED ONLY A FEW COUNTIES OVER...DECIDED IT
WAS TIME TO GO AHEAD AND EXPAND THE CHANCES FOR PRECIP THIS MORNING.
AS IT IS NOW...IT LOOKS LIKE ALL OF THE COUNTIES ALONG THE TENNESSEE
BORDER...AS WELL AS THE NEXT TIER OF COUNTIES NORTHWARD WILL LIKELY
BE AFFECTED BY LIGHT SNOW AND POTENTIAL SLEET THIS MORNING. LATEST HI
RES MODELS...INCLUDING THE HRRR AND NAM 12 ARE SHOWING THE SYSTEM
LOSING INTENSITY VERY QUICKLY THIS MORNING...AND CUTTING OFF PRECIP
CHANCES ACROSS OUR CWA WITHIN THE NEXT FEW HOURS. HOWEVER...GIVEN THE
LEVEL OF UNCERTAINTY...AND THE ONGOING STRONG REFLECTIVITIES...ERRED
ON THE PESSIMISTIC SIDE AND KEPT MENTION OF SNOW AND ICE IN UNTIL MID
MORNING. ALSO...WENT AHEAD AND ISSUED A SPECIAL WEATHER STATEMENT
THROUGH 15Z FOR THE AFFECTED COUNTIES SINCE ANY PRECIP WILL LIKELY
ACCUMULATE ON SURFACES DURING THE MORNING COMMUTE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 358 AM EST THU DEC 18 2014
SURFACE HIGH PRESSURE CONTINUES TO BE IN CHARGE FOR THE OHIO RIVER
VALLEY AND MANY POINTS TO OUR NORTH AND SOUTH. STRONG SUBSIDENCE
TRAPPING LOW LEVEL MOISTURE ACROSS THE NE PORTION OF THE CWA HAS LED
TO CONTINUED MVFR CLOUDS...WHICH ACCORDING TO THE LATEST FORECAST
SOUNDINGS...SHOULDN/T BE BUDGING UNTIL SOMETIME EARLY THIS
AFTERNOON. MEANWHILE...ALOFT...A SHORTWAVE IS CONTINUING TO DAMPEN
AS IT TRACKS EASTWARD...AND SHOULD BE POISED TO REACH THE
MISSISSIPPI RIVER VALLEY BETWEEN 12 AND 18Z TODAY. SO FAR...THIS
SYSTEM HAS BROUGHT LIGHT PRECIP ACROSS FAR SW KY...AS IT CONTINUES
TO SHIFT EASTWARD TOWARDS OUR SW CWA DURING THE EARLY MORNING HOURS.
THE AMOUNT OF LOW LEVEL DRY AIR IS STILL A CONCERN IN THIS AREA OF
THE CWA...AND WHETHER OR NOT THE PRECIP CAN OVERCOME IT. EXPECTING
BEST CHANCES FOR WEATHER ACROSS WAYNE AND MCCREARY COUNTIES GIVEN
THE LATEST HI RES MODEL DATA...INCLUDING THE HRRR AND ECMWF.
FORECAST SOUNDINGS ARE SHOWING BELOW FREEZING SURFACE TEMPS AT THESE
LOCATIONS...BUT WITH THE POTENTIAL FOR A SLIGHT WARM NOSE TEETERING
ALONG THE FREEZING LINE SEVERAL THOUSAND FEET ABOVE GROUND THROUGH
18Z. AS SUCH...WENT AHEAD AND MENTIONED SOME ICE PELLETS ALONG WITH
A CHANCE OF SNOW IN THESE TWO COUNTIES...WITH A SLIGHT CHANCE OF
LIGHT SNOW EVENTUALLY MIXING WITH RAIN AFTERWARDS ELSEWHERE IN THE
SW CWA.
THE SHORTWAVE WILL EVENTUALLY FLATTEN AND SHIFT EAST OF KY BY 06Z
FRIDAY ELIMINATING ANY FURTHER PRECIP CONCERNS FOR THE SHORT TERM.
THE ONE CAVEAT WILL BE THE EXISTENCE OF THE MID LEVEL CLOUDS WITH
MUCH OF THE TEMPERATURE PROFILE /INCLUDING SURFACE TEMPS/ DROPPING
BELOW FREEZING BY THIS EVENING AND THROUGHOUT THE OVERNIGHT. A FEW
FLURRIES MAY GET SQUEEZED OUT ACROSS THE CWA DURING THE EVENING. IN
FACT...MAY NOT HAVE EXTENDED THE FLURRY POTENTIAL FAR ENOUGH ACROSS
THE CWA. BUT THE CONFIDENCE IS STILL QUITE LOW ON THIS SUBJECT.
CONTINUED TO GO ABOVE GUIDANCE FOR CLOUD COVER OVER THE NEXT 36
HOURS AS MID/LOW LEVEL CLOUDS LOOK TO STICK AROUND THROUGH
FRIDAY...BEFORE ANOTHER ROUND OF HIGH CLOUDS WORKS INTO THE CWA.
THIS MAY INHIBIT SOME OF THE BEST RIDGE VALLEY SPLIT POTENTIAL
TONIGHT. OVERALL...TEMPERATURES SHOULD/T DEVIATE MUCH FROM WHAT WAS
SEEN IN THE PREVIOUS 24 HOURS. HIGHS TODAY WILL GENERALLY BE IN THE
UPPER 30S AND LOW 40S...WITH OVERNIGHT LOWS TONIGHT DROPPING DOWN
INTO THE UPPER 20S. WINDS AT THE SURFACE WILL REMAIN QUITE LIGHT AND
VARIABLE THROUGH THE SHORT TERM...WHILE ABOVE THE CONTINUED MID
LEVEL SUBSIDENCE INVERSION...THEY WILL INCREASE RAPIDLY THANKS TO A
WEST TO EAST ORIENTED JET STREAK WHICH IS CURRENTLY PUSHING ALONG
AND SOUTH OF KY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 358 AM EST THU DEC 18 2014
A FAIRLY ACTIVE PATTERN IN STORE FOR THE EXTENDED PORTION OF THE
FORECAST. THE MODELS AREA IN PRETTY GOOD AGREEMENT WITH THE LARGE
SCALE UPPER LEVEL FLOW PATTERN THROUGH MID WEEK. THREE SYSTEMS ARE
FORECAST TO AFFECT EASTERN KENTUCKY...THE FIRST BEING A WEAK AREA OF
LOW PRESSURE THAT IS FORECAST TO FORM OVER THE SOUTHERN PLAINS AND
THEN PROGRESS EASTWARD ACROSS THE GULF COAST FRIDAY NIGHT THROUGH
SATURDAY NIGHT. THE SECOND AND THIRD WEATHER SYSTEMS TO AFFECT THE
REGION...SHOULD THE MODELS PAN OUT...WOULD COME MONDAY THROUGH
WEDNESDAY OF NEXT WEEK. THE FIRST OF THESE LATE PERIOD SYSTEMS IS
PROGGED TO ORIGINATE OVER THE GULF OF MEXICO AND MOVE UP THE EASTERN
SLOPES OF THE APPALACHIAN MOUNTAINS MONDAY AND MONDAY NIGHT. THE
SECOND WEATHER SYSTEM IN THIS SCENARIO IS FORECAST TO TAKE SHAPE
OVER THE NORTHERN PLAINS TO BEGIN THE NEW WORK WEEK. THIS SECOND
SYSTEM WOULD COME IN THE FORM OF A LARGE SCALE AND MUCH DEEPER
TROUGH THAN EITHER OF THE SOUTHERN STREAM SYSTEMS. THIS AREA OF LOW
PRESSURE WOULD PROVIDE THE SOURCE OF COLD AIR THAT COULD BRING SUB
FREEZING TEMPERATURES AND SNOW NEXT WEDNESDAY NIGHT.
THE UNCERTAINTY WITH THIS WEEKENDS WEATHER WILL REVOLVE AROUND HOW
MUCH COLD AIR WILL BE ABLE TO FILTER INTO THE AREA AS THE SOUTHERN
PLAINS LOW MAKES ITS NORTHEASTERN TURN FRIDAY NIGHT. BASED ON THE
LATEST MODEL SOUNDINGS AND TIME HEIGHTS...THERE IS SOME UNCERTAINTY
AS TO HOW FAR SOUTH THE COLD AIR WILL PENETRATE FRIDAY NIGHT INTO
SATURDAY MORNING. BASED ON THIS...DECIDED TO CONFINE ANY
ACCUMULATING SNOW TO THE AREA NORTH OF THE MOUNTAIN PARKWAY BETWEEN
6 AND 12Z FRIDAY NIGHT. THE SNOW SHOULD THEN TRANSITION TO A RAIN
SNOW MIX EARLY SATURDAY MORNING...AND THEN TO ALL RAIN BY EARLY
SATURDAY AFTERNOON. ANY SNOW ACCUMULATIONS THAT DO OCCUR WOULD
LIKELY BE CONFINED TO GRASSY AREAS AND ELEVATED SURFACES. OUR FAR
EASTERN COUNTIES COULD SEE ANOTHER SHOT OF RAIN SNOW MIX OR ALL SNOW
FOR A BRIEF PERIOD SATURDAY NIGHT AS THE LOW EXITS THE AREA AND
WINDS SHIFT TO THE NORTH NORTHEAST. A WEAK RIDGE OF HIGH PRESSURE
ALOFT SHOULD PROVIDE A BRIEF RESPITE FROM THE WINTRY WEATHER LATE
SATURDAY NIGHT THROUGH MID MORNING ON SUNDAY. THE MODELS ONCE AGAIN
OFFER UP SOME UNCERTAINTY AS TO EXACTLY WHEN PRECIPITATION ONSET
WILL BE ON SUNDAY...WITH THE GFS MODEL HOLDING OFF A LOT LONGER THAN
THE ECMWF. BASED ON THIS...WENT WITH A BLEND BETWEEN THE TWO MODELS
FOR PRECIP ONSET ON SUNDAY ACROSS OUR EASTERN COUNTIES...WITH LIGHT
RAIN AFFECTING THE SOUTHEASTERN TWO THIRDS OF THE AREA AS MOISTURE
FROM THE GULF LOW BEGINS TO MOVE NORTHWARD INTO THE AREA. THE BETTER
SHOT OF PRECIPITATION WILL COME FROM MONDAY NIGHT THROUGH WEDNESDAY
EVENING...AS A MUCH STRONGER AND WETTER WEATHER SYSTEM DIVES OUT OF
THE NORTHERN PLAINS AND PHASES WITH WHAT EVER ENERGY IS LEFT OVER
FROM THE GULF OF MEXICO WEATHER SYSTEM. MOST OF THE PRECIPITATION
WITH THIS THIRD WEATHER SYSTEM LOOKS TO BE IN THE FORM OF RAIN BASED
ON THE TEMPERATURE PROFILES SEEN IN THE LATEST MODEL DATA. COULD SEE
SOME MORE SNOW WITH THIS FINAL WEATHER SYSTEM AS WINDS SHIFT TO THE
WEST AND NORTHWEST BEHIND THE LOW AS IT MOVES INTO NEW ENGLAND AND
COLDER AIR SPILLS INTO THE REGION.
THE OTHER WEATHER CONCERN OF NOTE FOR THE END OF THE EXTENDED PERIOD
WILL BE WINDS...PARTICULARLY FROM WEDNESDAY ONWARD. THE MODELS ALL
AGREE THAT A WELL DEVELOPED PRESSURE GRADIENT WILL ACCOMPANY THE
GREAT PLAINS WEATHER SYSTEM AS IT MOVES EAST. SUSTAINED WEST TO
NORTHWEST WINDS OF 10 TO 15 MPH...WITH GUSTS OF 20 TO 25 MPH...WILL
NOT BE OUT OF THE QUESTION. TEMPERATURES THROUGHOUT THE EXTENDED
PERIOD LOOK TO BE AT OR SLIGHTLY ABOVE NORMAL FROM SUNDAY THROUGH
WEDNESDAY. THE WARMEST STRETCH DURING THAT TIME WOULD BE MONDAY AND
TUESDAY...AS WINDS SHIFT TO THE SOUTH AHEAD OF THE MID WEEK WEATHER
SYSTEM. HIGHS ON EACH OF THOSE DAYS ARE EXPECTED TO TOP OUT IN THE
UPPER 40S AND LOWER 50S RESPECTIVELY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 656 AM EST THU DEC 18 2014
AN UPPER LEVEL DISTURBANCE IS BRINGING MOISTURE ACROSS SOUTHERN
KENTUCKY THIS MORNING. SURFACE HIGH PRESSURE...HOWEVER...IS MAKING
IT HARD FOR THE MAJORITY OF THIS MOISTURE TO MAKE IT THROUGH THE
LAYER OF DRY AIR AT THE SURFACE. IT IS POSSIBLE FOR KSME AND KLOZ TO
SEE A FEW SPURTS OF SNOW AND POSSIBLY SLEET AS WE HEAD INTO THE MID
MORNING. HOWEVER...THE LIGHT AND ISOLTED NATURE OF THIS PRECIP IS
NOT LIKELY TO CAUSE VIS RESTRICTIONS...SO CONTINUED TO KEEP MENTION
OF PRECIP OUT OF THE TAF. FOR THE REMAINING TAF SITES...LESS
INFLUENCE FROM THIS UPPER LEVEL DISTURBANCE HAS LEFT HIGH PRESSURE TO
RULE THE SKIES. THIS HAS RESULTED IN A STRONG SUBSIDENCE
INVERSION...TRAPPING LOW LEVEL MOISTURE AND CREATING A MVFR CIG DECK.
EXPECT BOTH THE LLVL CLOUD DECK...AND ANY REMAINING PRECIP
CHANCES...TO DISSIPATE AS WE HEAD INTO THE LATE MORNING/EARLY
AFTERNOON. WHILE WINDS WILL REMAIN LIGHT NEAR THE SURFACE...A WEST TO
EAST ORIENTED UPPER LEVEL JET STREAK WILL KEEP STRONG WESTERLY WIND
FLOW ABOVE THE HIGH PRESSURE INVERSION /AROUND 6K FT AGL/ FOR THE
NEXT 24 HOURS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...JMW
LONG TERM...AR
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
657 AM EST THU DEC 18 2014
.UPDATE...
ISSUED AT 552 AM EST THU DEC 18 2014
THERE IS A FAIR AMOUNT OF RADAR RETURNS MAKING IT INTO SOUTHEAST
KY...UNLIKE WHAT MANY OF THE HI RES MODELS WERE SHOWING EARLIER.
DESPITE THE DRY AIR IN PLACE AT THE SURFACE...DEW POINT DEPRESSIONS
HAVE LESSENED TO 0 IN SOME OF OUR SOUTHWESTERN COUNTIES. AND WITH
SNOW AND SLEET BEING REPORTED ONLY A FEW COUNTIES OVER...DECIDED IT
WAS TIME TO GO AHEAD AND EXPAND THE CHANCES FOR PRECIP THIS MORNING.
AS IT IS NOW...IT LOOKS LIKE ALL OF THE COUNTIES ALONG THE TENNESSEE
BORDER...AS WELL AS THE NEXT TIER OF COUNTIES NORTHWARD WILL LIKELY
BE AFFECTED BY LIGHT SNOW AND POTENTIAL SLEET THIS MORNING. LATEST HI
RES MODELS...INCLUDING THE HRRR AND NAM 12 ARE SHOWING THE SYSTEM
LOSING INTENSITY VERY QUICKLY THIS MORNING...AND CUTTING OFF PRECIP
CHANCES ACROSS OUR CWA WITHIN THE NEXT FEW HOURS. HOWEVER...GIVEN THE
LEVEL OF UNCERTAINTY...AND THE ONGOING STRONG REFLECTIVITIES...ERRED
ON THE PESSIMISTIC SIDE AND KEPT MENTION OF SNOW AND ICE IN UNTIL MID
MORNING. ALSO...WENT AHEAD AND ISSUED A SPECIAL WEATHER STATEMENT
THROUGH 15Z FOR THE AFFECTED COUNTIES SINCE ANY PRECIP WILL LIKELY
ACCUMULATE ON SURFACES DURING THE MORNING COMMUTE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 358 AM EST THU DEC 18 2014
SURFACE HIGH PRESSURE CONTINUES TO BE IN CHARGE FOR THE OHIO RIVER
VALLEY AND MANY POINTS TO OUR NORTH AND SOUTH. STRONG SUBSIDENCE
TRAPPING LOW LEVEL MOISTURE ACROSS THE NE PORTION OF THE CWA HAS LED
TO CONTINUED MVFR CLOUDS...WHICH ACCORDING TO THE LATEST FORECAST
SOUNDINGS...SHOULDN/T BE BUDGING UNTIL SOMETIME EARLY THIS
AFTERNOON. MEANWHILE...ALOFT...A SHORTWAVE IS CONTINUING TO DAMPEN
AS IT TRACKS EASTWARD...AND SHOULD BE POISED TO REACH THE
MISSISSIPPI RIVER VALLEY BETWEEN 12 AND 18Z TODAY. SO FAR...THIS
SYSTEM HAS BROUGHT LIGHT PRECIP ACROSS FAR SW KY...AS IT CONTINUES
TO SHIFT EASTWARD TOWARDS OUR SW CWA DURING THE EARLY MORNING HOURS.
THE AMOUNT OF LOW LEVEL DRY AIR IS STILL A CONCERN IN THIS AREA OF
THE CWA...AND WHETHER OR NOT THE PRECIP CAN OVERCOME IT. EXPECTING
BEST CHANCES FOR WEATHER ACROSS WAYNE AND MCCREARY COUNTIES GIVEN
THE LATEST HI RES MODEL DATA...INCLUDING THE HRRR AND ECMWF.
FORECAST SOUNDINGS ARE SHOWING BELOW FREEZING SURFACE TEMPS AT THESE
LOCATIONS...BUT WITH THE POTENTIAL FOR A SLIGHT WARM NOSE TEETERING
ALONG THE FREEZING LINE SEVERAL THOUSAND FEET ABOVE GROUND THROUGH
18Z. AS SUCH...WENT AHEAD AND MENTIONED SOME ICE PELLETS ALONG WITH
A CHANCE OF SNOW IN THESE TWO COUNTIES...WITH A SLIGHT CHANCE OF
LIGHT SNOW EVENTUALLY MIXING WITH RAIN AFTERWARDS ELSEWHERE IN THE
SW CWA.
THE SHORTWAVE WILL EVENTUALLY FLATTEN AND SHIFT EAST OF KY BY 06Z
FRIDAY ELIMINATING ANY FURTHER PRECIP CONCERNS FOR THE SHORT TERM.
THE ONE CAVEAT WILL BE THE EXISTENCE OF THE MID LEVEL CLOUDS WITH
MUCH OF THE TEMPERATURE PROFILE /INCLUDING SURFACE TEMPS/ DROPPING
BELOW FREEZING BY THIS EVENING AND THROUGHOUT THE OVERNIGHT. A FEW
FLURRIES MAY GET SQUEEZED OUT ACROSS THE CWA DURING THE EVENING. IN
FACT...MAY NOT HAVE EXTENDED THE FLURRY POTENTIAL FAR ENOUGH ACROSS
THE CWA. BUT THE CONFIDENCE IS STILL QUITE LOW ON THIS SUBJECT.
CONTINUED TO GO ABOVE GUIDANCE FOR CLOUD COVER OVER THE NEXT 36
HOURS AS MID/LOW LEVEL CLOUDS LOOK TO STICK AROUND THROUGH
FRIDAY...BEFORE ANOTHER ROUND OF HIGH CLOUDS WORKS INTO THE CWA.
THIS MAY INHIBIT SOME OF THE BEST RIDGE VALLEY SPLIT POTENTIAL
TONIGHT. OVERALL...TEMPERATURES SHOULD/T DEVIATE MUCH FROM WHAT WAS
SEEN IN THE PREVIOUS 24 HOURS. HIGHS TODAY WILL GENERALLY BE IN THE
UPPER 30S AND LOW 40S...WITH OVERNIGHT LOWS TONIGHT DROPPING DOWN
INTO THE UPPER 20S. WINDS AT THE SURFACE WILL REMAIN QUITE LIGHT AND
VARIABLE THROUGH THE SHORT TERM...WHILE ABOVE THE CONTINUED MID
LEVEL SUBSIDENCE INVERSION...THEY WILL INCREASE RAPIDLY THANKS TO A
WEST TO EAST ORIENTED JET STREAK WHICH IS CURRENTLY PUSHING ALONG
AND SOUTH OF KY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 358 AM EST THU DEC 18 2014
A FAIRLY ACTIVE PATTERN IN STORE FOR THE EXTENDED PORTION OF THE
FORECAST. THE MODELS AREA IN PRETTY GOOD AGREEMENT WITH THE LARGE
SCALE UPPER LEVEL FLOW PATTERN THROUGH MID WEEK. THREE SYSTEMS ARE
FORECAST TO AFFECT EASTERN KENTUCKY...THE FIRST BEING A WEAK AREA OF
LOW PRESSURE THAT IS FORECAST TO FORM OVER THE SOUTHERN PLAINS AND
THEN PROGRESS EASTWARD ACROSS THE GULF COAST FRIDAY NIGHT THROUGH
SATURDAY NIGHT. THE SECOND AND THIRD WEATHER SYSTEMS TO AFFECT THE
REGION...SHOULD THE MODELS PAN OUT...WOULD COME MONDAY THROUGH
WEDNESDAY OF NEXT WEEK. THE FIRST OF THESE LATE PERIOD SYSTEMS IS
PROGGED TO ORIGINATE OVER THE GULF OF MEXICO AND MOVE UP THE EASTERN
SLOPES OF THE APPALACHIAN MOUNTAINS MONDAY AND MONDAY NIGHT. THE
SECOND WEATHER SYSTEM IN THIS SCENARIO IS FORECAST TO TAKE SHAPE
OVER THE NORTHERN PLAINS TO BEGIN THE NEW WORK WEEK. THIS SECOND
SYSTEM WOULD COME IN THE FORM OF A LARGE SCALE AND MUCH DEEPER
TROUGH THAN EITHER OF THE SOUTHERN STREAM SYSTEMS. THIS AREA OF LOW
PRESSURE WOULD PROVIDE THE SOURCE OF COLD AIR THAT COULD BRING SUB
FREEZING TEMPERATURES AND SNOW NEXT WEDNESDAY NIGHT.
THE UNCERTAINTY WITH THIS WEEKENDS WEATHER WILL REVOLVE AROUND HOW
MUCH COLD AIR WILL BE ABLE TO FILTER INTO THE AREA AS THE SOUTHERN
PLAINS LOW MAKES ITS NORTHEASTERN TURN FRIDAY NIGHT. BASED ON THE
LATEST MODEL SOUNDINGS AND TIME HEIGHTS...THERE IS SOME UNCERTAINTY
AS TO HOW FAR SOUTH THE COLD AIR WILL PENETRATE FRIDAY NIGHT INTO
SATURDAY MORNING. BASED ON THIS...DECIDED TO CONFINE ANY
ACCUMULATING SNOW TO THE AREA NORTH OF THE MOUNTAIN PARKWAY BETWEEN
6 AND 12Z FRIDAY NIGHT. THE SNOW SHOULD THEN TRANSITION TO A RAIN
SNOW MIX EARLY SATURDAY MORNING...AND THEN TO ALL RAIN BY EARLY
SATURDAY AFTERNOON. ANY SNOW ACCUMULATIONS THAT DO OCCUR WOULD
LIKELY BE CONFINED TO GRASSY AREAS AND ELEVATED SURFACES. OUR FAR
EASTERN COUNTIES COULD SEE ANOTHER SHOT OF RAIN SNOW MIX OR ALL SNOW
FOR A BRIEF PERIOD SATURDAY NIGHT AS THE LOW EXITS THE AREA AND
WINDS SHIFT TO THE NORTH NORTHEAST. A WEAK RIDGE OF HIGH PRESSURE
ALOFT SHOULD PROVIDE A BRIEF RESPITE FROM THE WINTRY WEATHER LATE
SATURDAY NIGHT THROUGH MID MORNING ON SUNDAY. THE MODELS ONCE AGAIN
OFFER UP SOME UNCERTAINTY AS TO EXACTLY WHEN PRECIPITATION ONSET
WILL BE ON SUNDAY...WITH THE GFS MODEL HOLDING OFF A LOT LONGER THAN
THE ECMWF. BASED ON THIS...WENT WITH A BLEND BETWEEN THE TWO MODELS
FOR PRECIP ONSET ON SUNDAY ACROSS OUR EASTERN COUNTIES...WITH LIGHT
RAIN AFFECTING THE SOUTHEASTERN TWO THIRDS OF THE AREA AS MOISTURE
FROM THE GULF LOW BEGINS TO MOVE NORTHWARD INTO THE AREA. THE BETTER
SHOT OF PRECIPITATION WILL COME FROM MONDAY NIGHT THROUGH WEDNESDAY
EVENING...AS A MUCH STRONGER AND WETTER WEATHER SYSTEM DIVES OUT OF
THE NORTHERN PLAINS AND PHASES WITH WHAT EVER ENERGY IS LEFT OVER
FROM THE GULF OF MEXICO WEATHER SYSTEM. MOST OF THE PRECIPITATION
WITH THIS THIRD WEATHER SYSTEM LOOKS TO BE IN THE FORM OF RAIN BASED
ON THE TEMPERATURE PROFILES SEEN IN THE LATEST MODEL DATA. COULD SEE
SOME MORE SNOW WITH THIS FINAL WEATHER SYSTEM AS WINDS SHIFT TO THE
WEST AND NORTHWEST BEHIND THE LOW AS IT MOVES INTO NEW ENGLAND AND
COLDER AIR SPILLS INTO THE REGION.
THE OTHER WEATHER CONCERN OF NOTE FOR THE END OF THE EXTENDED PERIOD
WILL BE WINDS...PARTICULARLY FROM WEDNESDAY ONWARD. THE MODELS ALL
AGREE THAT A WELL DEVELOPED PRESSURE GRADIENT WILL ACCOMPANY THE
GREAT PLAINS WEATHER SYSTEM AS IT MOVES EAST. SUSTAINED WEST TO
NORTHWEST WINDS OF 10 TO 15 MPH...WITH GUSTS OF 20 TO 25 MPH...WILL
NOT BE OUT OF THE QUESTION. TEMPERATURES THROUGHOUT THE EXTENDED
PERIOD LOOK TO BE AT OR SLIGHTLY ABOVE NORMAL FROM SUNDAY THROUGH
WEDNESDAY. THE WARMEST STRETCH DURING THAT TIME WOULD BE MONDAY AND
TUESDAY...AS WINDS SHIFT TO THE SOUTH AHEAD OF THE MID WEEK WEATHER
SYSTEM. HIGHS ON EACH OF THOSE DAYS ARE EXPECTED TO TOP OUT IN THE
UPPER 40S AND LOWER 50S RESPECTIVELY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 656 AM EST THU DEC 18 2014
AN UPPER LEVEL DISTURBANCE IS BRINGING MOISTURE ACROSS SOUTHERN
KENTUCKY THIS MORNING. SURFACE HIGH PRESSURE...HOWEVER...IS MAKING
IT HARD FOR THE MAJORITY OF THIS MOISTURE TO MAKE IT THROUGH THE
LAYER OF DRY AIR AT THE SURFACE. IT IS POSSIBLE FOR KSME AND KLOZ TO
SEE A FEW SPURTS OF SNOW AND POSSIBLY SLEET AS WE HEAD INTO THE MID
MORNING. HOWEVER...THE LIGHT AND ISOLTED NATURE OF THIS PRECIP IS
NOT LIKELY TO CAUSE VIS RESTRICTIONS...SO CONTINUED TO KEEP MENTION
OF PRECIP OUT OF THE TAF. FOR THE REMAINING TAF SITES...LESS
INFLUENCE FROM THIS UPPER LEVEL DISTURBANCE HAS LEFT HIGH PRESSURE TO
RULE THE SKIES. THIS HAS RESULTED IN A STRONG SUBSIDENCE
INVERSION...TRAPPING LOW LEVEL MOISTURE AND CREATING A MVFR CIG DECK.
EXPECT BOTH THE LLVL CLOUD DECK...AND ANY REMAINING PRECIP
CHANCES...TO DISSIPATE AS WE HEAD INTO THE LATE MORNING/EARLY
AFTERNOON. WHILE WINDS WILL REMAIN LIGHT NEAR THE SURFACE...A WEST TO
EAST ORIENTED UPPER LEVEL JET STREAK WILL KEEP STRONG WESTERLY WIND
FLOW ABOVE THE HIGH PRESSURE INVERSION /AROUND 6K FT AGL/ FOR THE
NEXT 24 HOURS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...JMW
LONG TERM...AR
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
553 AM EST THU DEC 18 2014
.UPDATE...
ISSUED AT 552 AM EST THU DEC 18 2014
THERE IS A FAIR AMOUNT OF RADAR RETURNS MAKING IT INTO SOUTHEAST
KY...UNLIKE WHAT MANY OF THE HI RES MODELS WERE SHOWING EARLIER.
DESPITE THE DRY AIR IN PLACE AT THE SURFACE...DEW POINT DEPRESSIONS
HAVE LESSENED TO 0 IN SOME OF OUR SOUTHWESTERN COUNTIES. AND WITH
SNOW AND SLEET BEING REPORTED ONLY A FEW COUNTIES OVER...DECIDED IT
WAS TIME TO GO AHEAD AND EXPAND THE CHANCES FOR PRECIP THIS MORNING.
AS IT IS NOW...IT LOOKS LIKE ALL OF THE COUNTIES ALONG THE TENNESSEE
BORDER...AS WELL AS THE NEXT TIER OF COUNTIES NORTHWARD WILL LIKELY
BE AFFECTED BY LIGHT SNOW AND POTENTIAL SLEET THIS MORNING. LATEST HI
RES MODELS...INCLUDING THE HRRR AND NAM 12 ARE SHOWING THE SYSTEM
LOSING INTENSITY VERY QUICKLY THIS MORNING...AND CUTTING OFF PRECIP
CHANCES ACROSS OUR CWA WITHIN THE NEXT FEW HOURS. HOWEVER...GIVEN THE
LEVEL OF UNCERTAINTY...AND THE ONGOING STRONG REFLECTIVITIES...ERRED
ON THE PESSIMISTIC SIDE AND KEPT MENTION OF SNOW AND ICE IN UNTIL MID
MORNING. ALSO...WENT AHEAD AND ISSUED A SPECIAL WEATHER STATEMENT
THROUGH 15Z FOR THE AFFECTED COUNTIES SINCE ANY PRECIP WILL LIKELY
ACCUMULATE ON SURFACES DURING THE MORNING COMMUTE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 358 AM EST THU DEC 18 2014
SURFACE HIGH PRESSURE CONTINUES TO BE IN CHARGE FOR THE OHIO RIVER
VALLEY AND MANY POINTS TO OUR NORTH AND SOUTH. STRONG SUBSIDENCE
TRAPPING LOW LEVEL MOISTURE ACROSS THE NE PORTION OF THE CWA HAS LED
TO CONTINUED MVFR CLOUDS...WHICH ACCORDING TO THE LATEST FORECAST
SOUNDINGS...SHOULDN/T BE BUDGING UNTIL SOMETIME EARLY THIS
AFTERNOON. MEANWHILE...ALOFT...A SHORTWAVE IS CONTINUING TO DAMPEN
AS IT TRACKS EASTWARD...AND SHOULD BE POISED TO REACH THE
MISSISSIPPI RIVER VALLEY BETWEEN 12 AND 18Z TODAY. SO FAR...THIS
SYSTEM HAS BROUGHT LIGHT PRECIP ACROSS FAR SW KY...AS IT CONTINUES
TO SHIFT EASTWARD TOWARDS OUR SW CWA DURING THE EARLY MORNING HOURS.
THE AMOUNT OF LOW LEVEL DRY AIR IS STILL A CONCERN IN THIS AREA OF
THE CWA...AND WHETHER OR NOT THE PRECIP CAN OVERCOME IT. EXPECTING
BEST CHANCES FOR WEATHER ACROSS WAYNE AND MCCREARY COUNTIES GIVEN
THE LATEST HI RES MODEL DATA...INCLUDING THE HRRR AND ECMWF.
FORECAST SOUNDINGS ARE SHOWING BELOW FREEZING SURFACE TEMPS AT THESE
LOCATIONS...BUT WITH THE POTENTIAL FOR A SLIGHT WARM NOSE TEETERING
ALONG THE FREEZING LINE SEVERAL THOUSAND FEET ABOVE GROUND THROUGH
18Z. AS SUCH...WENT AHEAD AND MENTIONED SOME ICE PELLETS ALONG WITH
A CHANCE OF SNOW IN THESE TWO COUNTIES...WITH A SLIGHT CHANCE OF
LIGHT SNOW EVENTUALLY MIXING WITH RAIN AFTERWARDS ELSEWHERE IN THE
SW CWA.
THE SHORTWAVE WILL EVENTUALLY FLATTEN AND SHIFT EAST OF KY BY 06Z
FRIDAY ELIMINATING ANY FURTHER PRECIP CONCERNS FOR THE SHORT TERM.
THE ONE CAVEAT WILL BE THE EXISTENCE OF THE MID LEVEL CLOUDS WITH
MUCH OF THE TEMPERATURE PROFILE /INCLUDING SURFACE TEMPS/ DROPPING
BELOW FREEZING BY THIS EVENING AND THROUGHOUT THE OVERNIGHT. A FEW
FLURRIES MAY GET SQUEEZED OUT ACROSS THE CWA DURING THE EVENING. IN
FACT...MAY NOT HAVE EXTENDED THE FLURRY POTENTIAL FAR ENOUGH ACROSS
THE CWA. BUT THE CONFIDENCE IS STILL QUITE LOW ON THIS SUBJECT.
CONTINUED TO GO ABOVE GUIDANCE FOR CLOUD COVER OVER THE NEXT 36
HOURS AS MID/LOW LEVEL CLOUDS LOOK TO STICK AROUND THROUGH
FRIDAY...BEFORE ANOTHER ROUND OF HIGH CLOUDS WORKS INTO THE CWA.
THIS MAY INHIBIT SOME OF THE BEST RIDGE VALLEY SPLIT POTENTIAL
TONIGHT. OVERALL...TEMPERATURES SHOULD/T DEVIATE MUCH FROM WHAT WAS
SEEN IN THE PREVIOUS 24 HOURS. HIGHS TODAY WILL GENERALLY BE IN THE
UPPER 30S AND LOW 40S...WITH OVERNIGHT LOWS TONIGHT DROPPING DOWN
INTO THE UPPER 20S. WINDS AT THE SURFACE WILL REMAIN QUITE LIGHT AND
VARIABLE THROUGH THE SHORT TERM...WHILE ABOVE THE CONTINUED MID
LEVEL SUBSIDENCE INVERSION...THEY WILL INCREASE RAPIDLY THANKS TO A
WEST TO EAST ORIENTED JET STREAK WHICH IS CURRENTLY PUSHING ALONG
AND SOUTH OF KY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 358 AM EST THU DEC 18 2014
A FAIRLY ACTIVE PATTERN IN STORE FOR THE EXTENDED PORTION OF THE
FORECAST. THE MODELS AREA IN PRETTY GOOD AGREEMENT WITH THE LARGE
SCALE UPPER LEVEL FLOW PATTERN THROUGH MID WEEK. THREE SYSTEMS ARE
FORECAST TO AFFECT EASTERN KENTUCKY...THE FIRST BEING A WEAK AREA OF
LOW PRESSURE THAT IS FORECAST TO FORM OVER THE SOUTHERN PLAINS AND
THEN PROGRESS EASTWARD ACROSS THE GULF COAST FRIDAY NIGHT THROUGH
SATURDAY NIGHT. THE SECOND AND THIRD WEATHER SYSTEMS TO AFFECT THE
REGION...SHOULD THE MODELS PAN OUT...WOULD COME MONDAY THROUGH
WEDNESDAY OF NEXT WEEK. THE FIRST OF THESE LATE PERIOD SYSTEMS IS
PROGGED TO ORIGINATE OVER THE GULF OF MEXICO AND MOVE UP THE EASTERN
SLOPES OF THE APPALACHIAN MOUNTAINS MONDAY AND MONDAY NIGHT. THE
SECOND WEATHER SYSTEM IN THIS SCENARIO IS FORECAST TO TAKE SHAPE
OVER THE NORTHERN PLAINS TO BEGIN THE NEW WORK WEEK. THIS SECOND
SYSTEM WOULD COME IN THE FORM OF A LARGE SCALE AND MUCH DEEPER
TROUGH THAN EITHER OF THE SOUTHERN STREAM SYSTEMS. THIS AREA OF LOW
PRESSURE WOULD PROVIDE THE SOURCE OF COLD AIR THAT COULD BRING SUB
FREEZING TEMPERATURES AND SNOW NEXT WEDNESDAY NIGHT.
THE UNCERTAINTY WITH THIS WEEKENDS WEATHER WILL REVOLVE AROUND HOW
MUCH COLD AIR WILL BE ABLE TO FILTER INTO THE AREA AS THE SOUTHERN
PLAINS LOW MAKES ITS NORTHEASTERN TURN FRIDAY NIGHT. BASED ON THE
LATEST MODEL SOUNDINGS AND TIME HEIGHTS...THERE IS SOME UNCERTAINTY
AS TO HOW FAR SOUTH THE COLD AIR WILL PENETRATE FRIDAY NIGHT INTO
SATURDAY MORNING. BASED ON THIS...DECIDED TO CONFINE ANY
ACCUMULATING SNOW TO THE AREA NORTH OF THE MOUNTAIN PARKWAY BETWEEN
6 AND 12Z FRIDAY NIGHT. THE SNOW SHOULD THEN TRANSITION TO A RAIN
SNOW MIX EARLY SATURDAY MORNING...AND THEN TO ALL RAIN BY EARLY
SATURDAY AFTERNOON. ANY SNOW ACCUMULATIONS THAT DO OCCUR WOULD
LIKELY BE CONFINED TO GRASSY AREAS AND ELEVATED SURFACES. OUR FAR
EASTERN COUNTIES COULD SEE ANOTHER SHOT OF RAIN SNOW MIX OR ALL SNOW
FOR A BRIEF PERIOD SATURDAY NIGHT AS THE LOW EXITS THE AREA AND
WINDS SHIFT TO THE NORTH NORTHEAST. A WEAK RIDGE OF HIGH PRESSURE
ALOFT SHOULD PROVIDE A BRIEF RESPITE FROM THE WINTRY WEATHER LATE
SATURDAY NIGHT THROUGH MID MORNING ON SUNDAY. THE MODELS ONCE AGAIN
OFFER UP SOME UNCERTAINTY AS TO EXACTLY WHEN PRECIPITATION ONSET
WILL BE ON SUNDAY...WITH THE GFS MODEL HOLDING OFF A LOT LONGER THAN
THE ECMWF. BASED ON THIS...WENT WITH A BLEND BETWEEN THE TWO MODELS
FOR PRECIP ONSET ON SUNDAY ACROSS OUR EASTERN COUNTIES...WITH LIGHT
RAIN AFFECTING THE SOUTHEASTERN TWO THIRDS OF THE AREA AS MOISTURE
FROM THE GULF LOW BEGINS TO MOVE NORTHWARD INTO THE AREA. THE BETTER
SHOT OF PRECIPITATION WILL COME FROM MONDAY NIGHT THROUGH WEDNESDAY
EVENING...AS A MUCH STRONGER AND WETTER WEATHER SYSTEM DIVES OUT OF
THE NORTHERN PLAINS AND PHASES WITH WHAT EVER ENERGY IS LEFT OVER
FROM THE GULF OF MEXICO WEATHER SYSTEM. MOST OF THE PRECIPITATION
WITH THIS THIRD WEATHER SYSTEM LOOKS TO BE IN THE FORM OF RAIN BASED
ON THE TEMPERATURE PROFILES SEEN IN THE LATEST MODEL DATA. COULD SEE
SOME MORE SNOW WITH THIS FINAL WEATHER SYSTEM AS WINDS SHIFT TO THE
WEST AND NORTHWEST BEHIND THE LOW AS IT MOVES INTO NEW ENGLAND AND
COLDER AIR SPILLS INTO THE REGION.
THE OTHER WEATHER CONCERN OF NOTE FOR THE END OF THE EXTENDED PERIOD
WILL BE WINDS...PARTICULARLY FROM WEDNESDAY ONWARD. THE MODELS ALL
AGREE THAT A WELL DEVELOPED PRESSURE GRADIENT WILL ACCOMPANY THE
GREAT PLAINS WEATHER SYSTEM AS IT MOVES EAST. SUSTAINED WEST TO
NORTHWEST WINDS OF 10 TO 15 MPH...WITH GUSTS OF 20 TO 25 MPH...WILL
NOT BE OUT OF THE QUESTION. TEMPERATURES THROUGHOUT THE EXTENDED
PERIOD LOOK TO BE AT OR SLIGHTLY ABOVE NORMAL FROM SUNDAY THROUGH
WEDNESDAY. THE WARMEST STRETCH DURING THAT TIME WOULD BE MONDAY AND
TUESDAY...AS WINDS SHIFT TO THE SOUTH AHEAD OF THE MID WEEK WEATHER
SYSTEM. HIGHS ON EACH OF THOSE DAYS ARE EXPECTED TO TOP OUT IN THE
UPPER 40S AND LOWER 50S RESPECTIVELY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1245 AM EST THU DEC 18 2014
HIGH PRESSURE OVERHEAD IS KEEPING A STRONG SUBSIDENCE INVERSION IN
PLACE ACROSS MUCH OF THE NORTHERN HALF OF THE CWA...TRAPPING LOW LEVEL
MOISTURE AND RESULTING IN OVC MVFR CIGS...INCLUDING AT KSJS AND KSYM
/AND IMPOSING ON KJKL FAIRLY QUICKLY/. MEANWHILE...A WEAK UPPER LEVEL
DISTURBANCE IS MOVING INTO THE MISSISSIPPI RIVER VALLEY...SPREADING
AN AREA OF HIGH CLOUDS OUT AHEAD OF IT. EXPECT THE SOUTHWARD
PROGRESSION OF THE LOW CLOUDS TO BE STOPPED BY THE INCOMING
DISTURBANCE...AND MVFR CIGS TO SIT IN PLACE OVER THE AFFECTED TAF
SITES THROUGH THE REMAINDER OF THE NIGHT. MODELS ARE STILL SHOWING
THIS DISTURBANCE BRINGING A CHANCE OF LIGHT PRECIP TO KSYM AND KLOZ.
HOWEVER...GIVEN THE STRONG SURGE OF LOW LEVEL DRY AIR IN THIS AREA /WHERE
LOW LEVEL CLOUD COVER HAS NOT BEEN A FACTOR/...IT WILL BE HARD FOR
ANY PRECIP TO REACH THE GROUND. MAY NOT RULE OUT SOME SPRINKLES OR
FLURRIES AS CIGS LOWER TO AROUND 5 TO 7K FT BETWEEN 10 AND 14Z THIS
MORNING...BUT GIVEN LOW CONFIDENCE AND MINIMAL IMPACTS...DID NOT
INCLUDE IN TAFS AT THIS TIME. ANY LINGERING LOW LEVEL CLOUDS LOOK TO
BREAK BETWEEN 15 AND 18Z TODAY. OTHERWISE...WHILE WESTERLY WINDS
ALOFT CONTINUE TO BE VERY STRONG...EXPECT LIGHT AND VARIABLE WINDS
WITHIN THE FIRST FEW THOUSAND FEET AGL.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...JMW
LONG TERM...AR
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
359 AM EST THU DEC 18 2014
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 358 AM EST THU DEC 18 2014
SURFACE HIGH PRESSURE CONTINUES TO BE IN CHARGE FOR THE OHIO RIVER
VALLEY AND MANY POINTS TO OUR NORTH AND SOUTH. STRONG SUBSIDENCE
TRAPPING LOW LEVEL MOISTURE ACROSS THE NE PORTION OF THE CWA HAS LED
TO CONTINUED MVFR CLOUDS...WHICH ACCORDING TO THE LATEST FORECAST
SOUNDINGS...SHOULDN/T BE BUDGING UNTIL SOMETIME EARLY THIS
AFTERNOON. MEANWHILE...ALOFT...A SHORTWAVE IS CONTINUING TO DAMPEN
AS IT TRACKS EASTWARD...AND SHOULD BE POISED TO REACH THE
MISSISSIPPI RIVER VALLEY BETWEEN 12 AND 18Z TODAY. SO FAR...THIS
SYSTEM HAS BROUGHT LIGHT PRECIP ACROSS FAR SW KY...AS IT CONTINUES
TO SHIFT EASTWARD TOWARDS OUR SW CWA DURING THE EARLY MORNING HOURS.
THE AMOUNT OF LOW LEVEL DRY AIR IS STILL A CONCERN IN THIS AREA OF
THE CWA...AND WHETHER OR NOT THE PRECIP CAN OVERCOME IT. EXPECTING
BEST CHANCES FOR WEATHER ACROSS WAYNE AND MCCREARY COUNTIES GIVEN
THE LATEST HI RES MODEL DATA...INCLUDING THE HRRR AND ECMWF.
FORECAST SOUNDINGS ARE SHOWING BELOW FREEZING SURFACE TEMPS AT THESE
LOCATIONS...BUT WITH THE POTENTIAL FOR A SLIGHT WARM NOSE TEETERING
ALONG THE FREEZING LINE SEVERAL THOUSAND FEET ABOVE GROUND THROUGH
18Z. AS SUCH...WENT AHEAD AND MENTIONED SOME ICE PELLETS ALONG WITH
A CHANCE OF SNOW IN THESE TWO COUNTIES...WITH A SLIGHT CHANCE OF
LIGHT SNOW EVENTUALLY MIXING WITH RAIN AFTERWARDS ELSEWHERE IN THE
SW CWA.
THE SHORTWAVE WILL EVENTUALLY FLATTEN AND SHIFT EAST OF KY BY 06Z
FRIDAY ELIMINATING ANY FURTHER PRECIP CONCERNS FOR THE SHORT TERM.
THE ONE CAVEAT WILL BE THE EXISTENCE OF THE MID LEVEL CLOUDS WITH
MUCH OF THE TEMPERATURE PROFILE /INCLUDING SURFACE TEMPS/ DROPPING
BELOW FREEZING BY THIS EVENING AND THROUGHOUT THE OVERNIGHT. A FEW
FLURRIES MAY GET SQUEEZED OUT ACROSS THE CWA DURING THE EVENING. IN
FACT...MAY NOT HAVE EXTENDED THE FLURRY POTENTIAL FAR ENOUGH ACROSS
THE CWA. BUT THE CONFIDENCE IS STILL QUITE LOW ON THIS SUBJECT.
CONTINUED TO GO ABOVE GUIDANCE FOR CLOUD COVER OVER THE NEXT 36
HOURS AS MID/LOW LEVEL CLOUDS LOOK TO STICK AROUND THROUGH
FRIDAY...BEFORE ANOTHER ROUND OF HIGH CLOUDS WORKS INTO THE CWA.
THIS MAY INHIBIT SOME OF THE BEST RIDGE VALLEY SPLIT POTENTIAL
TONIGHT. OVERALL...TEMPERATURES SHOULD/T DEVIATE MUCH FROM WHAT WAS
SEEN IN THE PREVIOUS 24 HOURS. HIGHS TODAY WILL GENERALLY BE IN THE
UPPER 30S AND LOW 40S...WITH OVERNIGHT LOWS TONIGHT DROPPING DOWN
INTO THE UPPER 20S. WINDS AT THE SURFACE WILL REMAIN QUITE LIGHT AND
VARIABLE THROUGH THE SHORT TERM...WHILE ABOVE THE CONTINUED MID
LEVEL SUBSIDENCE INVERSION...THEY WILL INCREASE RAPIDLY THANKS TO A
WEST TO EAST ORIENTED JET STREAK WHICH IS CURRENTLY PUSHING ALONG
AND SOUTH OF KY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 358 AM EST THU DEC 18 2014
A FAIRLY ACTIVE PATTERN IN STORE FOR THE EXTENDED PORTION OF THE
FORECAST. THE MODELS AREA IN PRETTY GOOD AGREEMENT WITH THE LARGE
SCALE UPPER LEVEL FLOW PATTERN THROUGH MID WEEK. THREE SYSTEMS ARE
FORECAST TO AFFECT EASTERN KENTUCKY...THE FIRST BEING A WEAK AREA OF
LOW PRESSURE THAT IS FORECAST TO FORM OVER THE SOUTHERN PLAINS AND
THEN PROGRESS EASTWARD ACROSS THE GULF COAST FRIDAY NIGHT THROUGH
SATURDAY NIGHT. THE SECOND AND THIRD WEATHER SYSTEMS TO AFFECT THE
REGION...SHOULD THE MODELS PAN OUT...WOULD COME MONDAY THROUGH
WEDNESDAY OF NEXT WEEK. THE FIRST OF THESE LATE PERIOD SYSTEMS IS
PROGGED TO ORIGINATE OVER THE GULF OF MEXICO AND MOVE UP THE EASTERN
SLOPES OF THE APPALACHIAN MOUNTAINS MONDAY AND MONDAY NIGHT. THE
SECOND WEATHER SYSTEM IN THIS SCENARIO IS FORECAST TO TAKE SHAPE
OVER THE NORTHERN PLAINS TO BEGIN THE NEW WORK WEEK. THIS SECOND
SYSTEM WOULD COME IN THE FORM OF A LARGE SCALE AND MUCH DEEPER
TROUGH THAN EITHER OF THE SOUTHERN STREAM SYSTEMS. THIS AREA OF LOW
PRESSURE WOULD PROVIDE THE SOURCE OF COLD AIR THAT COULD BRING SUB
FREEZING TEMPERATURES AND SNOW NEXT WEDNESDAY NIGHT.
THE UNCERTAINTY WITH THIS WEEKENDS WEATHER WILL REVOLVE AROUND HOW
MUCH COLD AIR WILL BE ABLE TO FILTER INTO THE AREA AS THE SOUTHERN
PLAINS LOW MAKES ITS NORTHEASTERN TURN FRIDAY NIGHT. BASED ON THE
LATEST MODEL SOUNDINGS AND TIME HEIGHTS...THERE IS SOME UNCERTAINTY
AS TO HOW FAR SOUTH THE COLD AIR WILL PENETRATE FRIDAY NIGHT INTO
SATURDAY MORNING. BASED ON THIS...DECIDED TO CONFINE ANY
ACCUMULATING SNOW TO THE AREA NORTH OF THE MOUNTAIN PARKWAY BETWEEN
6 AND 12Z FRIDAY NIGHT. THE SNOW SHOULD THEN TRANSITION TO A RAIN
SNOW MIX EARLY SATURDAY MORNING...AND THEN TO ALL RAIN BY EARLY
SATURDAY AFTERNOON. ANY SNOW ACCUMULATIONS THAT DO OCCUR WOULD
LIKELY BE CONFINED TO GRASSY AREAS AND ELEVATED SURFACES. OUR FAR
EASTERN COUNTIES COULD SEE ANOTHER SHOT OF RAIN SNOW MIX OR ALL SNOW
FOR A BRIEF PERIOD SATURDAY NIGHT AS THE LOW EXITS THE AREA AND
WINDS SHIFT TO THE NORTH NORTHEAST. A WEAK RIDGE OF HIGH PRESSURE
ALOFT SHOULD PROVIDE A BRIEF RESPITE FROM THE WINTRY WEATHER LATE
SATURDAY NIGHT THROUGH MID MORNING ON SUNDAY. THE MODELS ONCE AGAIN
OFFER UP SOME UNCERTAINTY AS TO EXACTLY WHEN PRECIPITATION ONSET
WILL BE ON SUNDAY...WITH THE GFS MODEL HOLDING OFF A LOT LONGER THAN
THE ECMWF. BASED ON THIS...WENT WITH A BLEND BETWEEN THE TWO MODELS
FOR PRECIP ONSET ON SUNDAY ACROSS OUR EASTERN COUNTIES...WITH LIGHT
RAIN AFFECTING THE SOUTHEASTERN TWO THIRDS OF THE AREA AS MOISTURE
FROM THE GULF LOW BEGINS TO MOVE NORTHWARD INTO THE AREA. THE BETTER
SHOT OF PRECIPITATION WILL COME FROM MONDAY NIGHT THROUGH WEDNESDAY
EVENING...AS A MUCH STRONGER AND WETTER WEATHER SYSTEM DIVES OUT OF
THE NORTHERN PLAINS AND PHASES WITH WHAT EVER ENERGY IS LEFT OVER
FROM THE GULF OF MEXICO WEATHER SYSTEM. MOST OF THE PRECIPITATION
WITH THIS THIRD WEATHER SYSTEM LOOKS TO BE IN THE FORM OF RAIN BASED
ON THE TEMPERATURE PROFILES SEEN IN THE LATEST MODEL DATA. COULD SEE
SOME MORE SNOW WITH THIS FINAL WEATHER SYSTEM AS WINDS SHIFT TO THE
WEST AND NORTHWEST BEHIND THE LOW AS IT MOVES INTO NEW ENGLAND AND
COLDER AIR SPILLS INTO THE REGION.
THE OTHER WEATHER CONCERN OF NOTE FOR THE END OF THE EXTENDED PERIOD
WILL BE WINDS...PARTICULARLY FROM WEDNESDAY ONWARD. THE MODELS ALL
AGREE THAT A WELL DEVELOPED PRESSURE GRADIENT WILL ACCOMPANY THE
GREAT PLAINS WEATHER SYSTEM AS IT MOVES EAST. SUSTAINED WEST TO
NORTHWEST WINDS OF 10 TO 15 MPH...WITH GUSTS OF 20 TO 25 MPH...WILL
NOT BE OUT OF THE QUESTION. TEMPERATURES THROUGHOUT THE EXTENDED
PERIOD LOOK TO BE AT OR SLIGHTLY ABOVE NORMAL FROM SUNDAY THROUGH
WEDNESDAY. THE WARMEST STRETCH DURING THAT TIME WOULD BE MONDAY AND
TUESDAY...AS WINDS SHIFT TO THE SOUTH AHEAD OF THE MID WEEK WEATHER
SYSTEM. HIGHS ON EACH OF THOSE DAYS ARE EXPECTED TO TOP OUT IN THE
UPPER 40S AND LOWER 50S RESPECTIVELY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1245 AM EST THU DEC 18 2014
HIGH PRESSURE OVERHEAD IS KEEPING A STRONG SUBSIDENCE INVERSION IN
PLACE ACROSS MUCH OF THE NORTHERN HALF OF THE CWA...TRAPPING LOW LEVEL
MOISTURE AND RESULTING IN OVC MVFR CIGS...INCLUDING AT KSJS AND KSYM
/AND IMPOSING ON KJKL FAIRLY QUICKLY/. MEANWHILE...A WEAK UPPER LEVEL
DISTURBANCE IS MOVING INTO THE MISSISSIPPI RIVER VALLEY...SPREADING
AN AREA OF HIGH CLOUDS OUT AHEAD OF IT. EXPECT THE SOUTHWARD
PROGRESSION OF THE LOW CLOUDS TO BE STOPPED BY THE INCOMING
DISTURBANCE...AND MVFR CIGS TO SIT IN PLACE OVER THE AFFECTED TAF
SITES THROUGH THE REMAINDER OF THE NIGHT. MODELS ARE STILL SHOWING
THIS DISTURBANCE BRINGING A CHANCE OF LIGHT PRECIP TO KSYM AND KLOZ.
HOWEVER...GIVEN THE STRONG SURGE OF LOW LEVEL DRY AIR IN THIS AREA /WHERE
LOW LEVEL CLOUD COVER HAS NOT BEEN A FACTOR/...IT WILL BE HARD FOR
ANY PRECIP TO REACH THE GROUND. MAY NOT RULE OUT SOME SPRINKLES OR
FLURRIES AS CIGS LOWER TO AROUND 5 TO 7K FT BETWEEN 10 AND 14Z THIS
MORNING...BUT GIVEN LOW CONFIDENCE AND MINIMAL IMPACTS...DID NOT
INCLUDE IN TAFS AT THIS TIME. ANY LINGERING LOW LEVEL CLOUDS LOOK TO
BREAK BETWEEN 15 AND 18Z TODAY. OTHERWISE...WHILE WESTERLY WINDS
ALOFT CONTINUE TO BE VERY STRONG...EXPECT LIGHT AND VARIABLE WINDS
WITHIN THE FIRST FEW THOUSAND FEET AGL.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JMW
LONG TERM...AR
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
1245 AM EST THU DEC 18 2014
.UPDATE...
ISSUED AT 1050 PM EST WED DEC 17 2014
HOURLY GRIDS HAVE BEEN UPDATED BASED ON RECENT TRENDS IN OBSERVATIONS
AND SATELLITE IMAGERY. STRATOCU HAS REDEVELOPED OVER THE SOUTHEASTERN
COUNTIES AND IS SPREADING BACK SOUTH ACROSS NORTHEASTERN KY AS WELL.
AS THE MID AND HIGH CLOUDS GRADUALLY ADVANCE IN FROM THE SOUTHWEST
CONFIDENCE IN THIS LOW DECK IS NOT EXTREMELY HIGH...BUT CLOUDS WILL
GRADUALLY INCREASE. WITH THE CLOUD FORECAST BEING LOW CONFIDENCE...IT
ALSO LEADS TO A TRICKY HOURLY TEMPERATURE FORECAST. MANY VALLEY
LOCATIONS THAT ARE CLOUD FREE ARE IN THE MID AND UPPER 20S AND MAY
DROP A COUPLE MORE DEGREES DURING BREAKS IN THE CLOUDS AND WHERE
CLOUDS DO NOT INCREASE FOR A FEW MORE HOURS. RECENT HRRR RUNS SUPPORT
A SLIGHTLY HIGHER CHANCE FOR LIGHT PRECIPITATION IN THE SOUTHWEST
REACHING THE GROUND NEAR DAWN AND OVERCOMING DRY AIR CENTERED NEAR
850 MB. THIS WOULD PROBABLY FALL AS ALL SNOW DUE TO WETBULBING. THIS
WOULD MAINLY BE FOR THE LAKE CUMBERLAND REGION COUNTIES OF WAYNE AND
MCCREARY AND POSSIBLY EXTENDING INTO ADJACENT PARTS OF SOUTHERN
PULASKI... SOUTHWEST LAUREL AND WESTERN WHITLEY COUNTIES.
OTHERWISE...THE LOW LEVELS SHOULD REMAIN TOO DRY FOR ANYTHING MORE
THAN VIRGA OR SOME STRAY FLURRIES OR SPRINKLES ON THU...BUT THERE
WILL BE PLENTY OF CLOUDS.
UPDATE ISSUED AT 815 PM EST WED DEC 17 2014
HOURLY GRIDS HAVE BEEN ADJUSTED TO ACCOUNT FOR THE CLEARING SOUTH OF
THE INTERSTATE 64 CORRIDOR AND HOURLY TEMPERATURE TRENDS. SOME
LOCATIONS SUCH AS JKL AND SME AS WELL AS VALLEY LOCATIONS ARE RUNNING
BELOW THE PREVIOUS FORECAST SO THE FIRST FEW HOURS WERE TRENDED
ACCORDINGLY ALTHOUGH MIN T FOR THE REST OF THE NIGHT WAS UNCHANGED FOR
MOST LOCATIONS. LIGHT PRECIP OR VIRGA WILL APPROACH THE SW PART OF THE
CWA TOWARD DAWN...BUT WILL BE STRUGGLING TO OVERCOME SIGNIFICANT LOW
LEVEL DRY AIR.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 310 PM EST WED DEC 17 2014
19Z SFC ANALYSIS SHOWS HIGH PRESSURE STARTING TO MORE EFFECTIVELY
MOVE INTO THE AREA. THIS IS BEGINNING TO BREAK UP THE LOW LEVEL CLOUD
COVER ACROSS AT LEAST THE SOUTHERN HALF OF THE CWA. THESE CLOUDS HAVE
KEPT TEMPERATURES IN CHECK SO FAR TODAY WITH READINGS GENERALLY IN
THE MID TO UPPER 30S NORTH AND IN THE LOWER 40S IN THE SOUTHEAST
WHERE SOME EARLY SUNSHINE IS MAKING ITS PRESENCE FELT. DEWPOINTS HAVE
DRIED OUT THROUGH THE DAY AND ARE NOW IN THE UPPER 20S TO LOWER 30S.
WINDS HAVE BEEN RELATIVELY LIGHT GENERALLY FROM THE WEST AT 5 TO 10
KTS TODAY.
THE MODELS ARE NOW IN PRETTY GOOD AGREEMENT ALOFT THROUGH THE SHORT
TERM PORTION OF THE FORECAST. THEY ALL DEPICT THE CLOSED...BUT
PROGRESSIVE...UPPER LOW THAT WILL SKIRT EAST THROUGH THE LOWER GREAT
LAKES THIS EVENING AND OVERNIGHT. A BRIEF PERIOD OF RIDGING WILL
FOLLOW INTO THURSDAY MORNING FOR EASTERN KENTUCKY BEFORE A RATHER
DAMPENED WAVE MOVES THROUGH LATER IN THE DAY AND THAT NIGHT WITH
SOME WEAK MID-LEVEL ENERGY FLOWING INTO THE CONFLUENCE ZONE EAST OF
THE AREA. WITH THE GENERAL MODEL AGREEMENT HAVE FOLLOWED THE HIGH
RESOLUTION NAM12 AND HRRR MOST CLOSELY FOR WEATHER DETAILS.
SENSIBLE WEATHER WILL FEATURE A BRIEF TIME OF CLEARING THIS EVENING
AND INTO TONIGHT THAT SHOULD ALLOW FOR SOME DECENT RADIATIONAL
COOLING AND RIDGE TO VALLEY TEMPERATURE DIFFERENCES THROUGH MIDNIGHT.
THEREAFTER...HIGH AND MID LEVEL CLOUDS WILL RETURN TO THE AREA FROM
WEST TO EAST AND PUT A CAP ON THE COOLING...LIMITING FURTHER TERRAIN
DIFFERENCES FOR THE REST OF THE NIGHT. THESE CLOUDS WILL ATTEMPT TO
BRING SNOW TO THE SOUTHWESTERN PARTS OF THE AREA BEFORE DAWN...BUT IT
WILL HAVE TO OVERCOME THE DRYING TAKING PLACE ATTM. ACCORDINGLY...
HAVE UNDERCUT QPF AND POPS FROM THE NAM/MET FOR LATE TONIGHT INTO
THURSDAY MORNING. THE AREA OF LOW PRESSURE RESPONSIBLE FOR THE PCPN
THREAT WILL DAMPEN THROUGH THE MORNING AND FADE OUT BY AFTERNOON. FOR
THIS...HAVE LIMITED THE PCPN THREAT TO JUST FLURRIES AND SPRINKLES
FOR THE SECOND HALF OF THE DAY. ADDITIONAL MOISTURE WILL PASS BY TO
THE NORTH LATER THAT EVENING AND A FEW FLURRIES WILL BE POSSIBLE FROM
THIS ALONG WITH ANOTHER COOL NIGHT.
AGAIN USED THE BCCONSSHORT AS A STARTING POINT FOR THE T/TD/WIND
GRIDS FOR THE FIRST 20 HOURS OR SO BEFORE POPULATING WITH THE
SUPERBLEND THEREAFTER. MINOR ADJUSTMENTS WERE MADE FOR TERRAIN
EFFECTS BOTH TONIGHT AND THURSDAY NIGHT. AS FOR POPS...ENDED UP A BIT
UNDER THE MET NUMBERS AND CLOSER TO THE DRIER MAV ONES FOR TONIGHT
AND THURSDAY GIVEN THE DRY AIR THAT WILL BE IN PLACE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 340 PM EST WED DEC 17 2014
FORECAST MODELS ARE IN GOOD AGREEMENT ON AN ACTIVE WEATHER PATTERN
WITH AT LEAST TWO SYSTEMS TO AFFECT US THROUGH THE PERIOD.
THE FIRST STORM OVER THE WEEKEND CONTINUES TO LOOK RATHER WEAK. A
LIGHT RAIN/SNOW MIX WILL MOVE INTO THE AREA OVERNIGHT FRIDAY NIGHT.
THIS WILL CHANGE TO ALL RAIN DURING THE DAY ON SATURDAY...FOLLOWED
BY PERHAPS BY A LITTLE MORE SNOW AS THE PRECIPITATION ENDS SATURDAY
NIGHT. THERE IS JUST NOT A LOT OF COLD AIR IN PLACE AND
PRECIPITATION LOOKS LIGHT SO ANY SNOW ACCUMULATIONS WILL BE VERY
LIGHT WITH THIS SYSTEM...IF ANY OCCUR AT ALL.
A MUCH MORE IMPRESSIVE STORM SYSTEM IS SHOWING UP IN THE COMPUTER
MODELS FOR THE MIDDLE OF NEXT WEEK...WITH DECENT AGREEMENT ON AN
IMPACTFUL SYSTEM JUST IN TIME FOR PEAK HOLIDAY TRAVEL. AN UPPER
LEVEL TROUGH WILL DIG IN OVER THE PLAINS EARLY IN THE WEEK AND
BECOME NEGATIVELY TILTED OVER THE OHIO VALLEY MID WEEK. THIS CAUSES
EXPLOSIVE DEEPENING OF A SURFACE LOW PRESSURE WHICH IS PROGGED TO
DEVELOP AND TRACK OVER US OR VERY CLOSE TO US ON ITS WAY NORTH TO
THE GREAT LAKES. THIS SYSTEM IS STILL WAY TOO FAR OUT IN THE FUTURE
TO PINPOINT EXACTLY WHAT TYPE OF WEATHER WE WILL BE DEALING
WITH...BUT RAIN...WIND AND SNOW ARE ALL ON THE TABLE FROM TUESDAY
THROUGH WEDNESDAY...AND POTENTIALLY BEYOND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1245 AM EST THU DEC 18 2014
HIGH PRESSURE OVERHEAD IS KEEPING A STRONG SUBSIDENCE INVERSION IN
PLACE ACROSS MUCH OF THE NORTHERN HALF OF THE CWA...TRAPPING LOW LEVEL
MOISTURE AND RESULTING IN OVC MVFR CIGS...INCLUDING AT KSJS AND KSYM
/AND IMPOSING ON KJKL FAIRLY QUICKLY/. MEANWHILE...A WEAK UPPER LEVEL
DISTURBANCE IS MOVING INTO THE MISSISSIPPI RIVER VALLEY...SPREADING
AN AREA OF HIGH CLOUDS OUT AHEAD OF IT. EXPECT THE SOUTHWARD
PROGRESSION OF THE LOW CLOUDS TO BE STOPPED BY THE INCOMING
DISTURBANCE...AND MVFR CIGS TO SIT IN PLACE OVER THE AFFECTED TAF
SITES THROUGH THE REMAINDER OF THE NIGHT. MODELS ARE STILL SHOWING
THIS DISTURBANCE BRINGING A CHANCE OF LIGHT PRECIP TO KSYM AND KLOZ.
HOWEVER...GIVEN THE STRONG SURGE OF LOW LEVEL DRY AIR IN THIS AREA /WHERE
LOW LEVEL CLOUD COVER HAS NOT BEEN A FACTOR/...IT WILL BE HARD FOR
ANY PRECIP TO REACH THE GROUND. MAY NOT RULE OUT SOME SPRINKLES OR
FLURRIES AS CIGS LOWER TO AROUND 5 TO 7K FT BETWEEN 10 AND 14Z THIS
MORNING...BUT GIVEN LOW CONFIDENCE AND MINIMAL IMPACTS...DID NOT
INCLUDE IN TAFS AT THIS TIME. ANY LINGERING LOW LEVEL CLOUDS LOOK TO
BREAK BETWEEN 15 AND 18Z TODAY. OTHERWISE...WHILE WESTERLY WINDS
ALOFT CONTINUE TO BE VERY STRONG...EXPECT LIGHT AND VARIABLE WINDS
WITHIN THE FIRST FEW THOUSAND FEET AGL.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...ABE
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1201 PM CST THU DEC 18 2014
.DISCUSSION...
FOR 18Z TAF ISSUANCE.
&&
.AVIATION...
GENERALLY CARRIED THE PREVIOUS THINKING FOR THE DEVELOPMENT OF OUR
EXPECTED RAINFALL EVENT OVER THE NEXT 24 HOURS. MSAS SFC ANALYSIS
SHOWS A BIT OF A TROF EXTENDING SW-NE KINDA BISECTING THE FORECAST
AREA...AND THIS FEATURE APPEARS TO BE THE DEMARCATION LINE
BETWEEN LOW CEILINGS (<1K FEET) AND VFR CIGS. EXPECT ALL SITES TO
BE MVFR OR LOWER BY LATE AFTERNOON BEFORE GOING IFR OR WORSE FOR
THE REMAINDER OF THE PERIOD TONIGHT. LOCAL 88DS SHOW RAINS
LINGERING OVER MAINLY CNTL LA BUT THIS AREA OF PRECIP HAS ALREADY
PASSED KAEX. AS FAR AS THE SRN SITES...WILL CONTINUE TO HAVE TO
WATCH AN AREA OF RAIN OVER THE GULF WHICH COULD IMPACT THE SERN
SITES ALTHOUGH FOR NOW HAVE JUST RETAINED A VCSH MENTION THERE AS
TRAJECTORIES APPEAR TO CARRY THIS PRECIP S OF THE AREA. EXPECT
PREVAILING RAINS TO DEVELOP LATE TONIGHT AS THE WARM FRONT OVER
THE COASTAL WATERS BEGINS PUSHING NWD...AND ADDITIONAL ENERGY FROM
A SHORTWAVE ALOFT ALSO WORKS INTO THE MIX.
25
&&
.PREV DISCUSSION... /ISSUED 957 AM CST THU DEC 18 2014/
UPDATE...
WARM FRONTAL BOUNDARY SITTING OFF THE COAST MAKING FOR A MESSY
WEATHER PICTURE TODAY THROUGH FRIDAY. LOOKING AT THE CURRENT RADAR...
AN AREA OF RAIN AND SHOWERS ORIENTED SOUTHWEST TO NORTHEAST WILL
CONTINUE TO SLIDE EAST AND FILL IN SOUTHWARD CLOSE TO THE WARM FRONT.
UPDATED RAIN CHANCES REST OF THIS MORNING INTO THIS AFTERNOON TO COME
INTO AGREEMENT WITH THE LOCAL WRF MODEL AS WELL AS THE HIGH
RESOLUTION HRRR WHICH ARE BOTH SIGNALING RAIN COVERAGE INCREASING
THROUGHOUT THE DAY. TEMPERATURES LOOK REASONABLE...ONLY ADJUSTED DOWN
ONE TINY NOTCH. INCREASED CLOUD COVER TODAY AS WELL...IT IS GOING
TO BE MOSTLY CLOUDY FOR THE REMAINDER OF THE DAY.
PREV DISCUSSION... /ISSUED 545 AM CST THU DEC 18 2014/
AVIATION UPDATE...REGARDING 12Z TAF ISSUANCE. MVFR CEILINGS NOW
OVER OUR TERMINALS OF AEX AND BPT WILL OVERSPREAD THE REMAINDER OF
THE AREA AS THE MORNING PROGRESSES. THIS NORTH OF A WARM FRONT NOW
OVER THE NEAR COASTAL WATERS THAT IS EXPECTED TO RETREAT INTO THE
INLAND AREA THROUGH THE DAY. SCATTERED SHOWERS ARE ON TAP ALONG AND
AHEAD OF THE BOUNDARY. CARRYING VCSH AND TEMPO GROUPS AT VARIOUS
TIMES AT ALL TERMINALS. RAIN CHANCES THEN DIMINISH BY EARLY
EVENING...RAMPING UP AGAIN LATE TONIGHT WITH THE APPROACH OF A
SHORTWAVE TROF ADVANCING EAST ACROSS TEXAS.
MARCOTTE
PREV DISCUSSION... /ISSUED 501 AM CST THU DEC 18 2014/
DISCUSSION...
TEMPERATURES AROUND THE NATION RANGED FROM SINGLE DIGITS ACROSS
THE UPPER PLAINS STATES TO THE LOWER 70S AT BROWNSVILLE IN DEEP
SOUTH TEXAS.
THE WEATHER TODAY LOOKS TO BE A MESS AS WE BEGIN ANOTHER TRANSITION
TO A COLD FRONTAL PASSAGE LATE FRIDAY TIME FRAME. UNTIL THEN A
SURFACE LOW IS DEVELOPING OVER DEEP SOUTH TEXAS AND WILL LIFT
NORTHEAST TODAY DRAGGING WITH IT A WARM FRONT. RAINS TODAY ARE
GOING TO RIDE UP AND OVER THE WARM FRONT THAT IS LOCATED TO OUR
SOUTHWEST THIS MORNING. ISOLATED THUNDERSTORMS THIS AFTERNOON INTO
TONIGHT. TEMPS WILL RANGE FROM NEAR 70 BEHIND THE WARM FRONT IN
BEAUMONT TO 60 FOR THE LAKES REGION IN SOUTHEAST TEXAS AND CENTRAL
LOUISIANA UNDER CLOUDY SKIES. WINDS WILL REMAIN FROM THE NORTHEAST
INLAND TO EAST ALONG THE COAST TO SOUTHEAST IN THE COASTAL WATERS.
TONIGHT WILL SEE SHOWERS AND ISOLATED THUNDERSTORMS... TEMPERATURES
NOT AS COOL AS THIS MORNING AS THE WARM FRONT WILL LAY ALONG THE
I-10 CORRIDOR. THIS BOUNDARY WILL MORE OR LESS REMAIN STATIONARY
INTO FRIDAY MORNING TIME FRAME. SOUTH OF THE WARM FRONT THERE WILL
BE IS A CHANCE THAT SEVERAL STORMS MAY BECOME SEVERE WITH WINDS
THE MAIN THREAT. HEAVY RAINS ARE ALSO EXPECTED FOR THE LAKES
REGION IN SOUTHEAST TEXAS AND ACROSS CENTRAL LOUISIANA NORTH OF
THE WARM FRONT. AS THE LOW MOVES INTO SOUTHERN LOUISIANA ON FRIDAY
THIS WILL DRAG COOLER AND DRIER AIR DOWN INTO TEXAS WITH A COLD
FRONT PUSHING INTO SOUTHEAST TEXAS LATE IN THE DAY. THIS LATEST
FRONT IS EXPECTED TO EXIT SOUTH CENTRAL LOUISIANA FRIDAY EVENING
WITH RAINS ENDING EARLY SATURDAY MORNING. THE WEEKEND LOOKS TO BE
COOLER AND DRIER ALTHOUGH IT WILL TAKE AWHILE TO DRY OUT.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 65 55 64 46 57 / 60 60 90 30 10
KBPT 69 57 66 47 58 / 50 70 90 20 10
KAEX 56 50 53 42 54 / 50 70 90 50 10
KLFT 66 56 65 48 58 / 50 40 90 40 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSLAKECHARLES
WWW.TWITTER.COM/NWSLAKECHARLES
WWW.YOUTUBE.COM/NWSLAKECHARLES
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
957 AM CST THU DEC 18 2014
.UPDATE...
WARM FRONTAL BOUNDARY SITTING OFF THE COAST MAKING FOR A MESSY
WEATHER PICTURE TODAY THROUGH FRIDAY. LOOKING AT THE CURRENT RADAR...
AN AREA OF RAIN AND SHOWERS ORIENTED SOUTHWEST TO NORTHEAST WILL
CONTINUE TO SLIDE EAST AND FILL IN SOUTHWARD CLOSE TO THE WARM FRONT.
UPDATED RAIN CHANCES REST OF THIS MORNING INTO THIS AFTERNOON TO COME
INTO AGREEMENT WITH THE LOCAL WRF MODEL AS WELL AS THE HIGH
RESOLUTION HRRR WHICH ARE BOTH SIGNALING RAIN COVERAGE INCREASING
THROUGHOUT THE DAY. TEMPERATURES LOOK REASONABLE...ONLY ADJUSTED DOWN
ONE TINY NOTCH. INCREASED CLOUD COVER TODAY AS WELL...IT IS GOING
TO BE MOSTLY CLOUDY FOR THE REMAINDER OF THE DAY.
&&
.PREV DISCUSSION... /ISSUED 545 AM CST THU DEC 18 2014/
AVIATION UPDATE...REGARDING 12Z TAF ISSUANCE. MVFR CEILINGS NOW
OVER OUR TERMINALS OF AEX AND BPT WILL OVERSPREAD THE REMAINDER OF
THE AREA AS THE MORNING PROGRESSES. THIS NORTH OF A WARM FRONT NOW
OVER THE NEAR COASTAL WATERS THAT IS EXPECTED TO RETREAT INTO THE
INLAND AREA THROUGH THE DAY. SCATTERED SHOWERS ARE ON TAP ALONG AND
AHEAD OF THE BOUNDARY. CARRYING VCSH AND TEMPO GROUPS AT VARIOUS
TIMES AT ALL TERMINALS. RAIN CHANCES THEN DIMINISH BY EARLY
EVENING...RAMPING UP AGAIN LATE TONIGHT WITH THE APPROACH OF A
SHORTWAVE TROF ADVANCING EAST ACROSS TEXAS.
MARCOTTE
PREV DISCUSSION... /ISSUED 501 AM CST THU DEC 18 2014/
DISCUSSION...
TEMPERATURES AROUND THE NATION RANGED FROM SINGLE DIGITS ACROSS
THE UPPER PLAINS STATES TO THE LOWER 70S AT BROWNSVILLE IN DEEP
SOUTH TEXAS.
THE WEATHER TODAY LOOKS TO BE A MESS AS WE BEGIN ANOTHER TRANSITION
TO A COLD FRONTAL PASSAGE LATE FRIDAY TIME FRAME. UNTIL THEN A
SURFACE LOW IS DEVELOPING OVER DEEP SOUTH TEXAS AND WILL LIFT
NORTHEAST TODAY DRAGGING WITH IT A WARM FRONT. RAINS TODAY ARE
GOING TO RIDE UP AND OVER THE WARM FRONT THAT IS LOCATED TO OUR
SOUTHWEST THIS MORNING. ISOLATED THUNDERSTORMS THIS AFTERNOON INTO
TONIGHT. TEMPS WILL RANGE FROM NEAR 70 BEHIND THE WARM FRONT IN
BEAUMONT TO 60 FOR THE LAKES REGION IN SOUTHEAST TEXAS AND CENTRAL
LOUISIANA UNDER CLOUDY SKIES. WINDS WILL REMAIN FROM THE NORTHEAST
INLAND TO EAST ALONG THE COAST TO SOUTHEAST IN THE COASTAL WATERS.
TONIGHT WILL SEE SHOWERS AND ISOLATED THUNDERSTORMS... TEMPERATURES
NOT AS COOL AS THIS MORNING AS THE WARM FRONT WILL LAY ALONG THE
I-10 CORRIDOR. THIS BOUNDARY WILL MORE OR LESS REMAIN STATIONARY
INTO FRIDAY MORNING TIME FRAME. SOUTH OF THE WARM FRONT THERE WILL
BE IS A CHANCE THAT SEVERAL STORMS MAY BECOME SEVERE WITH WINDS
THE MAIN THREAT. HEAVY RAINS ARE ALSO EXPECTED FOR THE LAKES
REGION IN SOUTHEAST TEXAS AND ACROSS CENTRAL LOUISIANA NORTH OF
THE WARM FRONT. AS THE LOW MOVES INTO SOUTHERN LOUISIANA ON FRIDAY
THIS WILL DRAG COOLER AND DRIER AIR DOWN INTO TEXAS WITH A COLD
FRONT PUSHING INTO SOUTHEAST TEXAS LATE IN THE DAY. THIS LATEST
FRONT IS EXPECTED TO EXIT SOUTH CENTRAL LOUISIANA FRIDAY EVENING
WITH RAINS ENDING EARLY SATURDAY MORNING. THE WEEKEND LOOKS TO BE
COOLER AND DRIER ALTHOUGH IT WILL TAKE AWHILE TO DRY OUT.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 65 55 64 46 / 60 60 90 30
KBPT 69 57 66 47 / 50 70 90 20
KAEX 56 50 53 42 / 50 70 90 50
KLFT 66 56 65 48 / 50 40 90 40
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE...06
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
332 PM EST THU DEC 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM EST THU DEC 18 2014
AN UPPER RIDGE STRETCHING FROM MINNESOTA THROUGH NORTHWEST ONTARIO
WILL BE THE MAIN FEATURE CONTROLLING THE WEATHER OVER THE UPPER
GREAT LAKES REGION OVER THE NEXT 24 HOURS. BENEATH THIS UPPER
RIDGE...A 1029MB SURFACE HIGH SITS JUST TO THE NORTH OF THE
MINNESOTA WHILE THE SURFACE TROUGH THAT LED TO THE SNOW YESTERDAY
IS OVER NORTHERN LAKE MICHIGAN AND NORTHERN LOWER MICHIGAN AND
WEAKENING. NORTH-NORTHEASTERLY FLOW AROUND THIS HIGH HAS PULLED
DRIER AIR INTO THE UPPER GREAT LAKES REGION...LEADING TO CLEARING
SKIES THIS PAST EVENING OVER MUCH OF LAKE SUPERIOR. BUT MOISTURE
TRAPPED BELOW THE SUBSIDENCE INVERSION...AND COMBINED WITH UPSLOPE
FLOW...HAS LED TO LOW CLOUDS PERSISTING OVER A GOOD PORTION OF
UPPER MICHIGAN EARLY THIS MORNING. THERE ARE A COUPLE SPOTS WHERE
THE CLOUDS DID CLEAR OUT...GENERALLY OVER THE KEWEENAW PENINSULA
AND ALSO IT/S STARTING TO OVER THE EAST. WHERE SKIES CLEARED
OUT...3AM TEMPERATURES ARE IN THE SINGLE DIGITS ABOVE ZERO (6
DEGREES AT KCMX)...WHILE THE CLOUDS HAVE KEPT THE TEMPERATURES IN
THE UPPER TEENS AND LOWER 20S ELSEWHERE. STILL SEEING LIGHT
FLURRIES HERE AT OUR OFFICE AT 330AM...SO WILL CONTINUE TO MENTION
ISOLATED FLURRIES IN THE FORECAST FOR THE UPSLOPE LOCATIONS THROUGH
DAYBREAK.
WITH THE UPPER RIDGE AND SURFACE HIGH MOVING OVER THE AREA
TODAY...EXPECT CONTINUED QUIET CONDITIONS FOR THE SHORT TERM
PERIOD. THERE ARE TWO AREAS OF FOCUS IN THE SHORT TERM
PERIOD...FIRST THE LOW CLOUDS AND THEIR DIMINISHMENT AND THEN THE
POTENTIAL FOR SOME FREEZING FOG OVERNIGHT TONIGHT. FOR THE LOW
CLOUDS...KMQT VWP INDICATES CLOUD TOPS AROUND 2.5KFT...WHICH
MATCHES UP WELL WITH THE INVERSION INDICATED ON THE MODELS AT
900MB. THE BIG QUESTION IS WHEN WILL THEY DISSIPATE TODAY. AT
THIS TIME OF THE YEAR WITH THE LOW SUN ANGLE AND LIMITED
MIXING...THERE IS LITTLE DAY TIME HELP AND WILL NEED TO RELY ON THE
ADVECTION OF DRIER AIR INTO THE AREA. UNFORTUNATELY...THIS IS WHERE
THE MODELS TEND TO DIFFER. THE 00Z NAM HOLDS ONTO THE CLOUDS FOR
MUCH OF THE DAY AND EVEN THROUGH THE NIGHT TONIGHT...BUT THINK THAT
IS LARGELY TIED TO IT TRADITIONALLY OVER DOING LOW LEVEL MOISTURE.
THAT APPEARS TO THE CASE EARLY THIS MORNING...WHERE IT HAS THE LOW
CLOUDS JUST TO THE WEST OF JAMES BAY BEING MUCH FARTHER TO THE
SOUTH AND SUPPOSEDLY ENTERING NORTHERN LAKE SUPERIOR AT THIS TIME.
THE RECENT RAP (ALONG WITH THE HRRR) RUNS ALSO HOLD ONTO THE CLOUDS
FOR MUCH OF THE DAY BEFORE CLEARING THEM OUT THIS AFTERNOON...BUT IT
APPEARS TO HAVE THE LOW LEVEL MOISTURE FARTHER NORTH OVER LAKE
SUPERIOR THAN WHAT IS ACTUALLY OCCURRING. THE MORE OPTIMISTIC
RUNS...WHICH SEEM TO HAVE A BETTER HANDLE ON THE LOCATION OF THE
LOW CLOUDS ARE THE 00Z GFS/ECMWF. THEY HOLD ONTO THE LOW CLOUDS
OVER THE NORTH CENTRAL AND WEST FOR THE FIRST PART OF THE MORNING
AND THEN SCATTER THEM OUT THROUGH THE LATER PART OF THE MORNING AND
EARLY AFTERNOON. WILL FOLLOW THAT IDEA AT THIS POINT FOR THE CLOUD
COVER FORECAST FOR TODAY. MEANWHILE OVER THE EAST...THE ADVECTION
OF THE DRIER AIR AND LITTLE UPSLOPE HELP SHOULD ALLOW THE LOW
CLOUDS TO DISSIPATE DURING THE FIRST PART OF THE MORNING. THAT DRY
AIR HAS ALREADY SCATTERED THE CLOUDS OUT OVER LUCE COUNTY AND
STARTING TO SEE IT WORK INTO ALGER/SCHOOLCRAFT COUNTIES. AS FOR
HIGHS TODAY...EXPECT THEM TO BE IN THE MID-UPPER 20S OVER MUCH OF
THE AREA.
FOLLOWING THE IDEA OF THE CLOUDS DIMINISHING TODAY...WOULD EXPECT A
VERY GOOD RADIATIONAL COOLING NIGHT TONIGHT UNDER THE CENTER OF THE
HIGH. THUS...WILL CONTINUE THE IDEA OF GOING AT OR BELOW THE
COLDEST GUIDANCE. THE GEM MODELS USUALLY PERFORM WELL IN
RADIATIONAL COOLING NIGHTS AND THEY HAVE LOWS IN THE LOWER SINGLE
DIGITS WHERE THEY ARE NOT INDICATING CLOUDS (ALTHOUGH THE REGIONAL
GEM REDEVELOPS LOW CLOUDS OVER THE HIGHER TERRAIN OF THE NORTH
CENTRAL TONIGHT). THUS...HAVE LOWS IN THE SINGLE DIGITS ABOVE ZERO
TO AROUND ZERO OVER THE INTERIOR LOCATIONS. WITH KCMX DROPPING TO 6
DEGREES AT 3AM THIS MORNING...THAT SUPPORTS TO EXPECTATIONS FOR
TONIGHT. THIS EXPECTED DROP IN TEMPS WILL LEAD TO THE POTENTIAL FOR
PATCHY FREEZING FOG OR AT LEAST SOME SOLID FROST. WITH DEWPOINTS IN
THE MID-UPPER TEENS TODAY...TEMPS SHOULD EASILY DROP THROUGH THOSE
VALUES THIS EVENING. DEWPOINTS THIS PAST EVENING AT KCMX WERE
SIMILAR TO WHAT IS EXPECTED ACROSS THE REST OF THE AREA THIS
AFTERNOON. WITH THEIR QUICK TEMP DROP AND LIGHT WINDS...THEY HAVEN/T
EXPERIENCED ANY FOG AT THIS POINT...BUT THE ICE ACCRETION ALGORITHM
DID INDICATE SOME ICE ACCUMULATION. THIS IS LIKELY DUE TO THAT QUICK
DROP AND IN TURN SOME QUICK/HARD FROST ON THE SENSOR. IT WILL BE
INTERESTING TO SEE IF ANY VERY SHALLOW FOG DEVELOPS AT KCMX OVER
THE NEXT COUPLE HOURS...AS IT WILL FORESHADOW WHAT WILL OCCUR
TONIGHT.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 332 PM EST THU DEC 18 2014
NAM SHOWS A 500 MB RIDGE OVER THE LOWER GREAT LAKES 00Z SAT WITH A
CLOSED LOW OVER WESTERN ONTARIO. THE LOW DOES NOT MOVE MUCH ON
SATURDAY...BUT THE UPPER LEVEL TROUGH ASSOCIATED WITH THIS LOW MOVES
INTO THE UPPER GREAT LAKES AND THIS TROUGH REMAINS OVER THE UPPER
GREAT LAKES ON SUNDAY. LOOKS LIKE THE TROUGH REMAINS TO THE WEST AND
THE SYSTEM SNOW REMAINS TO THE WEST OF THE AREA AND WILL KEEP THE
FORECAST DRY FOR NOW. DID NOT MAKE TOO MANY CHANGES TO THE GOING
FORECAST.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE PLAINS
12Z MON AND THE TROUGH MOVES INTO THE UPPER GREAT LAKES 12Z TUE. THE
TROUGH AND LOW MOVES OVER THE UPPER GREAT LAKES 12Z WED AND THE
TROUGH MOVES INTO EASTERN CANADA ON THU. TEMPERATURES LOOK TO BE
NEAR NORMAL THIS FORECAST PERIOD AND LOOKS LIKE THE SURFACE LOW GOES
FAR ENOUGH SOUTH FOR THE MAJORITY OF THE PCPN WITH LAKE ENHANCED
SNOW FOR MOST OF THIS FORECAST PERIOD. WILL GO WITH CHANCE POPS
THROUGH THIS FORECAST AND KEEP THE PCPN AS SNOW EXCEPT NEAR THE
GREAT LAKES SHORELINES. WILL HAVE TO WATCH THIS SYSTEM FOR MON INTO
WED AS THE TRACK IS STILL UNCERTAIN AND THE TRACK WILL DETERMINE THE
PCPN TYPE. SIGNALS ARE THERE FOR A WINTER STORM SOMEWHERE IN THE
GREAT LAKES REGION AND WILL MENTION THIS IN THE HWO.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1251 PM EST THU DEC 18 2014
ONLY SCATTERED CLOUDS TODAY...BUT THERE IS POTENTIAL FOR VERY
SHALLOW FOG TONIGHT. BEST CHANCES FOR FOG IS AT KCMX...SO SHOWED A
DROP OF VIS. HOWEVER...WAS NOT CONFIDENT ENOUGH TO DROP CIGS AT THIS
TIME. IF FOG DOES DEVELOP...CONDITIONS WILL IMPROVE FRIDAY MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 403 AM EST THU DEC 18 2014
HIGH PRESSURE BUILDING INTO THE UPPER GREAT LAKES REGION TODAY AND
TONIGHT WILL DIMINISH THE NORTHERLY WINDS BELOW 15KTS. THE HIGH
WILL BEGIN TO SHIFT TO THE EAST OF THE REGION ON FRIDAY AND ALLOW
WINDS TO GRADUALLY TURN TO THE SOUTH THROUGH FRIDAY NIGHT. A NEARLY
STATIONARY TROUGH IN THE LEE OF THE NORTHERN ROCKIES THIS WEEKEND
WILL KEEP THE SOUTH TO SOUTHWESTERLY WINDS IN PLACE AND GENERALLY
UNDER 20KTS. THIS TROUGH WILL GIVE WAY TO A DEVELOPING LOW THAT
WILL MOVE INTO THE NORTHERN PLAINS SUNDAY NIGHT AND THE UPPER
MISSISSIPPI VALLEY ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...07
AVIATION...TITUS
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1255 PM EST THU DEC 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM EST THU DEC 18 2014
AN UPPER RIDGE STRETCHING FROM MINNESOTA THROUGH NORTHWEST ONTARIO
WILL BE THE MAIN FEATURE CONTROLLING THE WEATHER OVER THE UPPER
GREAT LAKES REGION OVER THE NEXT 24 HOURS. BENEATH THIS UPPER
RIDGE...A 1029MB SURFACE HIGH SITS JUST TO THE NORTH OF THE
MINNESOTA WHILE THE SURFACE TROUGH THAT LED TO THE SNOW YESTERDAY
IS OVER NORTHERN LAKE MICHIGAN AND NORTHERN LOWER MICHIGAN AND
WEAKENING. NORTH-NORTHEASTERLY FLOW AROUND THIS HIGH HAS PULLED
DRIER AIR INTO THE UPPER GREAT LAKES REGION...LEADING TO CLEARING
SKIES THIS PAST EVENING OVER MUCH OF LAKE SUPERIOR. BUT MOISTURE
TRAPPED BELOW THE SUBSIDENCE INVERSION...AND COMBINED WITH UPSLOPE
FLOW...HAS LED TO LOW CLOUDS PERSISTING OVER A GOOD PORTION OF
UPPER MICHIGAN EARLY THIS MORNING. THERE ARE A COUPLE SPOTS WHERE
THE CLOUDS DID CLEAR OUT...GENERALLY OVER THE KEWEENAW PENINSULA
AND ALSO IT/S STARTING TO OVER THE EAST. WHERE SKIES CLEARED
OUT...3AM TEMPERATURES ARE IN THE SINGLE DIGITS ABOVE ZERO (6
DEGREES AT KCMX)...WHILE THE CLOUDS HAVE KEPT THE TEMPERATURES IN
THE UPPER TEENS AND LOWER 20S ELSEWHERE. STILL SEEING LIGHT
FLURRIES HERE AT OUR OFFICE AT 330AM...SO WILL CONTINUE TO MENTION
ISOLATED FLURRIES IN THE FORECAST FOR THE UPSLOPE LOCATIONS THROUGH
DAYBREAK.
WITH THE UPPER RIDGE AND SURFACE HIGH MOVING OVER THE AREA
TODAY...EXPECT CONTINUED QUIET CONDITIONS FOR THE SHORT TERM
PERIOD. THERE ARE TWO AREAS OF FOCUS IN THE SHORT TERM
PERIOD...FIRST THE LOW CLOUDS AND THEIR DIMINISHMENT AND THEN THE
POTENTIAL FOR SOME FREEZING FOG OVERNIGHT TONIGHT. FOR THE LOW
CLOUDS...KMQT VWP INDICATES CLOUD TOPS AROUND 2.5KFT...WHICH
MATCHES UP WELL WITH THE INVERSION INDICATED ON THE MODELS AT
900MB. THE BIG QUESTION IS WHEN WILL THEY DISSIPATE TODAY. AT
THIS TIME OF THE YEAR WITH THE LOW SUN ANGLE AND LIMITED
MIXING...THERE IS LITTLE DAY TIME HELP AND WILL NEED TO RELY ON THE
ADVECTION OF DRIER AIR INTO THE AREA. UNFORTUNATELY...THIS IS WHERE
THE MODELS TEND TO DIFFER. THE 00Z NAM HOLDS ONTO THE CLOUDS FOR
MUCH OF THE DAY AND EVEN THROUGH THE NIGHT TONIGHT...BUT THINK THAT
IS LARGELY TIED TO IT TRADITIONALLY OVER DOING LOW LEVEL MOISTURE.
THAT APPEARS TO THE CASE EARLY THIS MORNING...WHERE IT HAS THE LOW
CLOUDS JUST TO THE WEST OF JAMES BAY BEING MUCH FARTHER TO THE
SOUTH AND SUPPOSEDLY ENTERING NORTHERN LAKE SUPERIOR AT THIS TIME.
THE RECENT RAP (ALONG WITH THE HRRR) RUNS ALSO HOLD ONTO THE CLOUDS
FOR MUCH OF THE DAY BEFORE CLEARING THEM OUT THIS AFTERNOON...BUT IT
APPEARS TO HAVE THE LOW LEVEL MOISTURE FARTHER NORTH OVER LAKE
SUPERIOR THAN WHAT IS ACTUALLY OCCURRING. THE MORE OPTIMISTIC
RUNS...WHICH SEEM TO HAVE A BETTER HANDLE ON THE LOCATION OF THE
LOW CLOUDS ARE THE 00Z GFS/ECMWF. THEY HOLD ONTO THE LOW CLOUDS
OVER THE NORTH CENTRAL AND WEST FOR THE FIRST PART OF THE MORNING
AND THEN SCATTER THEM OUT THROUGH THE LATER PART OF THE MORNING AND
EARLY AFTERNOON. WILL FOLLOW THAT IDEA AT THIS POINT FOR THE CLOUD
COVER FORECAST FOR TODAY. MEANWHILE OVER THE EAST...THE ADVECTION
OF THE DRIER AIR AND LITTLE UPSLOPE HELP SHOULD ALLOW THE LOW
CLOUDS TO DISSIPATE DURING THE FIRST PART OF THE MORNING. THAT DRY
AIR HAS ALREADY SCATTERED THE CLOUDS OUT OVER LUCE COUNTY AND
STARTING TO SEE IT WORK INTO ALGER/SCHOOLCRAFT COUNTIES. AS FOR
HIGHS TODAY...EXPECT THEM TO BE IN THE MID-UPPER 20S OVER MUCH OF
THE AREA.
FOLLOWING THE IDEA OF THE CLOUDS DIMINISHING TODAY...WOULD EXPECT A
VERY GOOD RADIATIONAL COOLING NIGHT TONIGHT UNDER THE CENTER OF THE
HIGH. THUS...WILL CONTINUE THE IDEA OF GOING AT OR BELOW THE
COLDEST GUIDANCE. THE GEM MODELS USUALLY PERFORM WELL IN
RADIATIONAL COOLING NIGHTS AND THEY HAVE LOWS IN THE LOWER SINGLE
DIGITS WHERE THEY ARE NOT INDICATING CLOUDS (ALTHOUGH THE REGIONAL
GEM REDEVELOPS LOW CLOUDS OVER THE HIGHER TERRAIN OF THE NORTH
CENTRAL TONIGHT). THUS...HAVE LOWS IN THE SINGLE DIGITS ABOVE ZERO
TO AROUND ZERO OVER THE INTERIOR LOCATIONS. WITH KCMX DROPPING TO 6
DEGREES AT 3AM THIS MORNING...THAT SUPPORTS TO EXPECTATIONS FOR
TONIGHT. THIS EXPECTED DROP IN TEMPS WILL LEAD TO THE POTENTIAL FOR
PATCHY FREEZING FOG OR AT LEAST SOME SOLID FROST. WITH DEWPOINTS IN
THE MID-UPPER TEENS TODAY...TEMPS SHOULD EASILY DROP THROUGH THOSE
VALUES THIS EVENING. DEWPOINTS THIS PAST EVENING AT KCMX WERE
SIMILAR TO WHAT IS EXPECTED ACROSS THE REST OF THE AREA THIS
AFTERNOON. WITH THEIR QUICK TEMP DROP AND LIGHT WINDS...THEY HAVEN/T
EXPERIENCED ANY FOG AT THIS POINT...BUT THE ICE ACCRETION ALGORITHM
DID INDICATE SOME ICE ACCUMULATION. THIS IS LIKELY DUE TO THAT QUICK
DROP AND IN TURN SOME QUICK/HARD FROST ON THE SENSOR. IT WILL BE
INTERESTING TO SEE IF ANY VERY SHALLOW FOG DEVELOPS AT KCMX OVER
THE NEXT COUPLE HOURS...AS IT WILL FORESHADOW WHAT WILL OCCUR
TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 514 AM EST THU DEC 18 2014
FRIDAY...A DRY AIRMASS ASSOCIATED WITH THE DEPARTING AREA OF
HIGH PRESSURE WILL LEAVE PARTLY TO MOSTLY SUNNY SKIES ACROSS UPPER
MICHIGAN. HOWEVER...THERE IS SOME UNCERTAINTY WHETHER MOISTURE
BENEATH THE PROMINENT 925 MB INVERSION WILL LINGER ENOUGH FOR MOSTLY
CLOUDY SKIES...ESPECIALLY OVER THE WEST. EVEN WITH SOME
CLOUDS...TEMPS ARE EXPECTED TO CLIMB INTO THE UPPER 20S.
FRI NIGHT...TEMPS SHOULD DROP OFF QUICKLY IN THE EVENING BUT MAY
REBOUND LATE AS CLOUDS INCREASE WITH STRENGTHENING 850 MB WAA AND
ASSOCIATED 280K ISENTROPIC ASCENT. WITH THE MID LEVEL REMAINING
DRY...NO PCPN IS EXPECTED.
SAT...AS THE SFC HIGH SLOWLY BUILDS INTO THE ERN LAKES...SRLY WINDS
WILL BRING WARMER AIR INTO THE REGION WITH TEMPS CLIMBING SLIGHTLY
ABOVE NORMAL WITH MAX READINGS CLIMB TO AROUND 30 DESPITE THE
THICKENING CLOUDS.
SUN...AS A MID LEVEL TROUGH DEVELOPS ACROSS THE CENTRAL CONUS...THE
MODELS SUGGEST POTENTIAL FOR A WEAK SHORTWAVE AND AREA OF MORE
SUBSTANTIAL 290K ISENTROPIC LIFT THAT COULD PRODUCE SOME LIGHT SNOW.
THE DYNAMICS REMAIN WEAK ENOUGH TO SUPPORT ONLY SLIGHT CHANCE POPS.
CONTINUED WAA WILL NUDGE MAX TEMPS INTO THE LOWER 30S.
MON-WED...ALTHOUGH THERE IS GENERAL MODEL AGREEMENT THAT A MID LEVEL
TROUGH WILL DEEPEN OVER THE NORTHERN GREAT LAKES...THERE ARE
CONSIDERABLE DIFFERENCES IN THE DETAILS OF HOW THE SHORTWAVES DIVING
INTO THE TROUGH WILL INTERACT AND HOW THAT WILL INFLUENCE
THE POSITION/STRENGTH OF THE SFC FEATURES. SNOW CHANCES INCREASE
FROM MON INTO MON NIGHT AS THE INITIAL LOW MOVES THROUGH THE UPPER MS
VALLEY. ENOUGH WARM AIR MAY BE DRAWN NORTHWARD TO BRING POTENTIAL FOR
SOME RAIN INTO THE EAST HALF. THE PREFERRED/MORE CONSISTENT 00Z/12Z
ECMWF KEEP THE LOW AND WARMER AIR SLIGHTLY FARTHER TO THE
SOUTH...MINIMIZING CHANCES FOR RAIN. THE LARGER DISPARITIES DEVELOP
BY WED WITH THE HANDLING OF A STRONGER SHRTWV THAT WOULD SUPPORT
RAPID DEEPENING OF THE SFC LOW. THE 18Z/00Z GFS AND 00Z ECMWF HAVE
BACKED OFF FROM THE VERY STRONG LOW MOVING INTO THE CNTRL LAKE AND
THEN NORTHWARD TOWARD JAMES BAY AND HAVE SHIFTED THE STRONGER LOW
THROUGH THE NORTHEAST CONUS. HOWEVER...IT WOULD NOT BE SURPRISING TO
SEE THE MODELS REVERT BACK TO THE STRONGER LOW THROUGH LOWER MI. WITH
SO MUCH UNCERTAINTY AND HIGH ENSEMBLE/MODEL SPREAD...THE FCST
MAINTAINS HIGHER END SNOW CHANCES BUT WITH LESS EMPHASIS FOR NOW ON
THE POTENTIAL FOR HEAVY SNOW AND HIGH WINDS UNTIL FCST CONFIDENCE IS
HIGHER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1251 PM EST THU DEC 18 2014
ONLY SCATTERED CLOUDS TODAY...BUT THERE IS POTENTIAL FOR VERY
SHALLOW FOG TONIGHT. BEST CHANCES FOR FOG IS AT KCMX...SO SHOWED A
DROP OF VIS. HOWEVER...WAS NOT CONFIDENT ENOUGH TO DROP CIGS AT THIS
TIME. IF FOG DOES DEVELOP...CONDITIONS WILL IMPROVE FRIDAY MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 403 AM EST THU DEC 18 2014
HIGH PRESSURE BUILDING INTO THE UPPER GREAT LAKES REGION TODAY AND
TONIGHT WILL DIMINISH THE NORTHERLY WINDS BELOW 15KTS. THE HIGH
WILL BEGIN TO SHIFT TO THE EAST OF THE REGION ON FRIDAY AND ALLOW
WINDS TO GRADUALLY TURN TO THE SOUTH THROUGH FRIDAY NIGHT. A NEARLY
STATIONARY TROUGH IN THE LEE OF THE NORTHERN ROCKIES THIS WEEKEND
WILL KEEP THE SOUTH TO SOUTHWESTERLY WINDS IN PLACE AND GENERALLY
UNDER 20KTS. THIS TROUGH WILL GIVE WAY TO A DEVELOPING LOW THAT
WILL MOVE INTO THE NORTHERN PLAINS SUNDAY NIGHT AND THE UPPER
MISSISSIPPI VALLEY ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...JLB
AVIATION...TITUS
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
637 AM EST THU DEC 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM EST THU DEC 18 2014
AN UPPER RIDGE STRETCHING FROM MINNESOTA THROUGH NORTHWEST ONTARIO
WILL BE THE MAIN FEATURE CONTROLLING THE WEATHER OVER THE UPPER
GREAT LAKES REGION OVER THE NEXT 24 HOURS. BENEATH THIS UPPER
RIDGE...A 1029MB SURFACE HIGH SITS JUST TO THE NORTH OF THE
MINNESOTA WHILE THE SURFACE TROUGH THAT LED TO THE SNOW YESTERDAY
IS OVER NORTHERN LAKE MICHIGAN AND NORTHERN LOWER MICHIGAN AND
WEAKENING. NORTH-NORTHEASTERLY FLOW AROUND THIS HIGH HAS PULLED
DRIER AIR INTO THE UPPER GREAT LAKES REGION...LEADING TO CLEARING
SKIES THIS PAST EVENING OVER MUCH OF LAKE SUPERIOR. BUT MOISTURE
TRAPPED BELOW THE SUBSIDENCE INVERSION...AND COMBINED WITH UPSLOPE
FLOW...HAS LED TO LOW CLOUDS PERSISTING OVER A GOOD PORTION OF
UPPER MICHIGAN EARLY THIS MORNING. THERE ARE A COUPLE SPOTS WHERE
THE CLOUDS DID CLEAR OUT...GENERALLY OVER THE KEWEENAW PENINSULA
AND ALSO IT/S STARTING TO OVER THE EAST. WHERE SKIES CLEARED
OUT...3AM TEMPERATURES ARE IN THE SINGLE DIGITS ABOVE ZERO (6
DEGREES AT KCMX)...WHILE THE CLOUDS HAVE KEPT THE TEMPERATURES IN
THE UPPER TEENS AND LOWER 20S ELSEWHERE. STILL SEEING LIGHT
FLURRIES HERE AT OUR OFFICE AT 330AM...SO WILL CONTINUE TO MENTION
ISOLATED FLURRIES IN THE FORECAST FOR THE UPSLOPE LOCATIONS THROUGH
DAYBREAK.
WITH THE UPPER RIDGE AND SURFACE HIGH MOVING OVER THE AREA
TODAY...EXPECT CONTINUED QUIET CONDITIONS FOR THE SHORT TERM
PERIOD. THERE ARE TWO AREAS OF FOCUS IN THE SHORT TERM
PERIOD...FIRST THE LOW CLOUDS AND THEIR DIMINISHMENT AND THEN THE
POTENTIAL FOR SOME FREEZING FOG OVERNIGHT TONIGHT. FOR THE LOW
CLOUDS...KMQT VWP INDICATES CLOUD TOPS AROUND 2.5KFT...WHICH
MATCHES UP WELL WITH THE INVERSION INDICATED ON THE MODELS AT
900MB. THE BIG QUESTION IS WHEN WILL THEY DISSIPATE TODAY. AT
THIS TIME OF THE YEAR WITH THE LOW SUN ANGLE AND LIMITED
MIXING...THERE IS LITTLE DAY TIME HELP AND WILL NEED TO RELY ON THE
ADVECTION OF DRIER AIR INTO THE AREA. UNFORTUNATELY...THIS IS WHERE
THE MODELS TEND TO DIFFER. THE 00Z NAM HOLDS ONTO THE CLOUDS FOR
MUCH OF THE DAY AND EVEN THROUGH THE NIGHT TONIGHT...BUT THINK THAT
IS LARGELY TIED TO IT TRADITIONALLY OVER DOING LOW LEVEL MOISTURE.
THAT APPEARS TO THE CASE EARLY THIS MORNING...WHERE IT HAS THE LOW
CLOUDS JUST TO THE WEST OF JAMES BAY BEING MUCH FARTHER TO THE
SOUTH AND SUPPOSEDLY ENTERING NORTHERN LAKE SUPERIOR AT THIS TIME.
THE RECENT RAP (ALONG WITH THE HRRR) RUNS ALSO HOLD ONTO THE CLOUDS
FOR MUCH OF THE DAY BEFORE CLEARING THEM OUT THIS AFTERNOON...BUT IT
APPEARS TO HAVE THE LOW LEVEL MOISTURE FARTHER NORTH OVER LAKE
SUPERIOR THAN WHAT IS ACTUALLY OCCURRING. THE MORE OPTIMISTIC
RUNS...WHICH SEEM TO HAVE A BETTER HANDLE ON THE LOCATION OF THE
LOW CLOUDS ARE THE 00Z GFS/ECMWF. THEY HOLD ONTO THE LOW CLOUDS
OVER THE NORTH CENTRAL AND WEST FOR THE FIRST PART OF THE MORNING
AND THEN SCATTER THEM OUT THROUGH THE LATER PART OF THE MORNING AND
EARLY AFTERNOON. WILL FOLLOW THAT IDEA AT THIS POINT FOR THE CLOUD
COVER FORECAST FOR TODAY. MEANWHILE OVER THE EAST...THE ADVECTION
OF THE DRIER AIR AND LITTLE UPSLOPE HELP SHOULD ALLOW THE LOW
CLOUDS TO DISSIPATE DURING THE FIRST PART OF THE MORNING. THAT DRY
AIR HAS ALREADY SCATTERED THE CLOUDS OUT OVER LUCE COUNTY AND
STARTING TO SEE IT WORK INTO ALGER/SCHOOLCRAFT COUNTIES. AS FOR
HIGHS TODAY...EXPECT THEM TO BE IN THE MID-UPPER 20S OVER MUCH OF
THE AREA.
FOLLOWING THE IDEA OF THE CLOUDS DIMINISHING TODAY...WOULD EXPECT A
VERY GOOD RADIATIONAL COOLING NIGHT TONIGHT UNDER THE CENTER OF THE
HIGH. THUS...WILL CONTINUE THE IDEA OF GOING AT OR BELOW THE
COLDEST GUIDANCE. THE GEM MODELS USUALLY PERFORM WELL IN
RADIATIONAL COOLING NIGHTS AND THEY HAVE LOWS IN THE LOWER SINGLE
DIGITS WHERE THEY ARE NOT INDICATING CLOUDS (ALTHOUGH THE REGIONAL
GEM REDEVELOPS LOW CLOUDS OVER THE HIGHER TERRAIN OF THE NORTH
CENTRAL TONIGHT). THUS...HAVE LOWS IN THE SINGLE DIGITS ABOVE ZERO
TO AROUND ZERO OVER THE INTERIOR LOCATIONS. WITH KCMX DROPPING TO 6
DEGREES AT 3AM THIS MORNING...THAT SUPPORTS TO EXPECTATIONS FOR
TONIGHT. THIS EXPECTED DROP IN TEMPS WILL LEAD TO THE POTENTIAL FOR
PATCHY FREEZING FOG OR AT LEAST SOME SOLID FROST. WITH DEWPOINTS IN
THE MID-UPPER TEENS TODAY...TEMPS SHOULD EASILY DROP THROUGH THOSE
VALUES THIS EVENING. DEWPOINTS THIS PAST EVENING AT KCMX WERE
SIMILAR TO WHAT IS EXPECTED ACROSS THE REST OF THE AREA THIS
AFTERNOON. WITH THEIR QUICK TEMP DROP AND LIGHT WINDS...THEY HAVEN/T
EXPERIENCED ANY FOG AT THIS POINT...BUT THE ICE ACCRETION ALGORITHM
DID INDICATE SOME ICE ACCUMULATION. THIS IS LIKELY DUE TO THAT QUICK
DROP AND IN TURN SOME QUICK/HARD FROST ON THE SENSOR. IT WILL BE
INTERESTING TO SEE IF ANY VERY SHALLOW FOG DEVELOPS AT KCMX OVER
THE NEXT COUPLE HOURS...AS IT WILL FORESHADOW WHAT WILL OCCUR
TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 514 AM EST THU DEC 18 2014
FRIDAY...A DRY AIRMASS ASSOCIATED WITH THE DEPARTING AREA OF
HIGH PRESSURE WILL LEAVE PARTLY TO MOSTLY SUNNY SKIES ACROSS UPPER
MICHIGAN. HOWEVER...THERE IS SOME UNCERTAINTY WHETHER MOISTURE
BENEATH THE PROMINENT 925 MB INVERSION WILL LINGER ENOUGH FOR MOSTLY
CLOUDY SKIES...ESPECIALLY OVER THE WEST. EVEN WITH SOME
CLOUDS...TEMPS ARE EXPECTED TO CLIMB INTO THE UPPER 20S.
FRI NIGHT...TEMPS SHOULD DROP OFF QUICKLY IN THE EVENING BUT MAY
REBOUND LATE AS CLOUDS INCREASE WITH STRENGTHENING 850 MB WAA AND
ASSOCIATED 280K ISENTROPIC ASCENT. WITH THE MID LEVEL REMAINING
DRY...NO PCPN IS EXPECTED.
SAT...AS THE SFC HIGH SLOWLY BUILDS INTO THE ERN LAKES...SRLY WINDS
WILL BRING WARMER AIR INTO THE REGION WITH TEMPS CLIMBING SLIGHTLY
ABOVE NORMAL WITH MAX READINGS CLIMB TO AROUND 30 DESPITE THE
THICKENING CLOUDS.
SUN...AS A MID LEVEL TROUGH DEVELOPS ACROSS THE CENTRAL CONUS...THE
MODELS SUGGEST POTENTIAL FOR A WEAK SHORTWAVE AND AREA OF MORE
SUBSTANTIAL 290K ISENTROPIC LIFT THAT COULD PRODUCE SOME LIGHT SNOW.
THE DYNAMICS REMAIN WEAK ENOUGH TO SUPPORT ONLY SLIGHT CHANCE POPS.
CONTINUED WAA WILL NUDGE MAX TEMPS INTO THE LOWER 30S.
MON-WED...ALTHOUGH THERE IS GENERAL MODEL AGREEMENT THAT A MID LEVEL
TROUGH WILL DEEPEN OVER THE NORTHERN GREAT LAKES...THERE ARE
CONSIDERABLE DIFFERENCES IN THE DETAILS OF HOW THE SHORTWAVES DIVING
INTO THE TROUGH WILL INTERACT AND HOW THAT WILL INFLUENCE
THE POSITION/STRENGTH OF THE SFC FEATURES. SNOW CHANCES INCREASE
FROM MON INTO MON NIGHT AS THE INITIAL LOW MOVES THROUGH THE UPPER MS
VALLEY. ENOUGH WARM AIR MAY BE DRAWN NORTHWARD TO BRING POTENTIAL FOR
SOME RAIN INTO THE EAST HALF. THE PREFERRED/MORE CONSISTENT 00Z/12Z
ECMWF KEEP THE LOW AND WARMER AIR SLIGHTLY FARTHER TO THE
SOUTH...MINIMIZING CHANCES FOR RAIN. THE LARGER DISPARITIES DEVELOP
BY WED WITH THE HANDLING OF A STRONGER SHRTWV THAT WOULD SUPPORT
RAPID DEEPENING OF THE SFC LOW. THE 18Z/00Z GFS AND 00Z ECMWF HAVE
BACKED OFF FROM THE VERY STRONG LOW MOVING INTO THE CNTRL LAKE AND
THEN NORTHWARD TOWARD JAMES BAY AND HAVE SHIFTED THE STRONGER LOW
THROUGH THE NORTHEAST CONUS. HOWEVER...IT WOULD NOT BE SURPRISING TO
SEE THE MODELS REVERT BACK TO THE STRONGER LOW THROUGH LOWER MI. WITH
SO MUCH UNCERTAINTY AND HIGH ENSEMBLE/MODEL SPREAD...THE FCST
MAINTAINS HIGHER END SNOW CHANCES BUT WITH LESS EMPHASIS FOR NOW ON
THE POTENTIAL FOR HEAVY SNOW AND HIGH WINDS UNTIL FCST CONFIDENCE IS
HIGHER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 637 AM EST THU DEC 18 2014
HIGH PRESSURE JUST TO THE NORTH OF THE MINNESOTA ARROWHEAD WILL
CONTINUE TO ROTATE DRIER AIR SOUTH OVER THE AREA TODAY. SKIES
CLEARED YESTERDAY EVENING OVER THE KEWEENAW PENINSULA AND THEY WILL
STAY CLEAR THROUGHOUT THE DAY TODAY WITH LIGHT WINDS. AT
KIWD/KSAW...THE MVFR CLOUDS CONTINUE TO BE TRAPPED BELOW THE
INVERSION...BUT THE DRIER AIR HAS BEEN SEEN MAKING A DENT OVER THE
CLOUD COVER...ESPECIALLY TOWARDS KSAW. WHILE CONFIDENCE IS LOW ON
THE EXACT TIMING OF THE SCATTERING OUT OF THE CLOUDS...IT SHOULD BE
BY MID TO LATE MORNING. VFR CONDITIONS AND MAINLY LIGHT WINDS WILL
REMAIN FOR THE REST OF THE DAY AND MUCH OF THE NIGHT. THERE IS THE
POTENTIAL FOR SOME VERY SHALLOW FOG TO DEVELOP OVERNIGHT TONIGHT AT
THE TAF SITES...BUT THE CONFIDENCE IS TOO LOW TO SHOW A CATEGORY
DROP.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 403 AM EST THU DEC 18 2014
HIGH PRESSURE BUILDING INTO THE UPPER GREAT LAKES REGION TODAY AND
TONIGHT WILL DIMINISH THE NORTHERLY WINDS BELOW 15KTS. THE HIGH
WILL BEGIN TO SHIFT TO THE EAST OF THE REGION ON FRIDAY AND ALLOW
WINDS TO GRADUALLY TURN TO THE SOUTH THROUGH FRIDAY NIGHT. A NEARLY
STATIONARY TROUGH IN THE LEE OF THE NORTHERN ROCKIES THIS WEEKEND
WILL KEEP THE SOUTH TO SOUTHWESTERLY WINDS IN PLACE AND GENERALLY
UNDER 20KTS. THIS TROUGH WILL GIVE WAY TO A DEVELOPING LOW THAT
WILL MOVE INTO THE NORTHERN PLAINS SUNDAY NIGHT AND THE UPPER
MISSISSIPPI VALLEY ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...JLB
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
517 AM EST THU DEC 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM EST THU DEC 18 2014
AN UPPER RIDGE STRETCHING FROM MINNESOTA THROUGH NORTHWEST ONTARIO
WILL BE THE MAIN FEATURE CONTROLLING THE WEATHER OVER THE UPPER
GREAT LAKES REGION OVER THE NEXT 24 HOURS. BENEATH THIS UPPER
RIDGE...A 1029MB SURFACE HIGH SITS JUST TO THE NORTH OF THE
MINNESOTA WHILE THE SURFACE TROUGH THAT LED TO THE SNOW YESTERDAY
IS OVER NORTHERN LAKE MICHIGAN AND NORTHERN LOWER MICHIGAN AND
WEAKENING. NORTH-NORTHEASTERLY FLOW AROUND THIS HIGH HAS PULLED
DRIER AIR INTO THE UPPER GREAT LAKES REGION...LEADING TO CLEARING
SKIES THIS PAST EVENING OVER MUCH OF LAKE SUPERIOR. BUT MOISTURE
TRAPPED BELOW THE SUBSIDENCE INVERSION...AND COMBINED WITH UPSLOPE
FLOW...HAS LED TO LOW CLOUDS PERSISTING OVER A GOOD PORTION OF
UPPER MICHIGAN EARLY THIS MORNING. THERE ARE A COUPLE SPOTS WHERE
THE CLOUDS DID CLEAR OUT...GENERALLY OVER THE KEWEENAW PENINSULA
AND ALSO IT/S STARTING TO OVER THE EAST. WHERE SKIES CLEARED
OUT...3AM TEMPERATURES ARE IN THE SINGLE DIGITS ABOVE ZERO (6
DEGREES AT KCMX)...WHILE THE CLOUDS HAVE KEPT THE TEMPERATURES IN
THE UPPER TEENS AND LOWER 20S ELSEWHERE. STILL SEEING LIGHT
FLURRIES HERE AT OUR OFFICE AT 330AM...SO WILL CONTINUE TO MENTION
ISOLATED FLURRIES IN THE FORECAST FOR THE UPSLOPE LOCATIONS THROUGH
DAYBREAK.
WITH THE UPPER RIDGE AND SURFACE HIGH MOVING OVER THE AREA
TODAY...EXPECT CONTINUED QUIET CONDITIONS FOR THE SHORT TERM
PERIOD. THERE ARE TWO AREAS OF FOCUS IN THE SHORT TERM
PERIOD...FIRST THE LOW CLOUDS AND THEIR DIMINISHMENT AND THEN THE
POTENTIAL FOR SOME FREEZING FOG OVERNIGHT TONIGHT. FOR THE LOW
CLOUDS...KMQT VWP INDICATES CLOUD TOPS AROUND 2.5KFT...WHICH
MATCHES UP WELL WITH THE INVERSION INDICATED ON THE MODELS AT
900MB. THE BIG QUESTION IS WHEN WILL THEY DISSIPATE TODAY. AT
THIS TIME OF THE YEAR WITH THE LOW SUN ANGLE AND LIMITED
MIXING...THERE IS LITTLE DAY TIME HELP AND WILL NEED TO RELY ON THE
ADVECTION OF DRIER AIR INTO THE AREA. UNFORTUNATELY...THIS IS WHERE
THE MODELS TEND TO DIFFER. THE 00Z NAM HOLDS ONTO THE CLOUDS FOR
MUCH OF THE DAY AND EVEN THROUGH THE NIGHT TONIGHT...BUT THINK THAT
IS LARGELY TIED TO IT TRADITIONALLY OVER DOING LOW LEVEL MOISTURE.
THAT APPEARS TO THE CASE EARLY THIS MORNING...WHERE IT HAS THE LOW
CLOUDS JUST TO THE WEST OF JAMES BAY BEING MUCH FARTHER TO THE
SOUTH AND SUPPOSEDLY ENTERING NORTHERN LAKE SUPERIOR AT THIS TIME.
THE RECENT RAP (ALONG WITH THE HRRR) RUNS ALSO HOLD ONTO THE CLOUDS
FOR MUCH OF THE DAY BEFORE CLEARING THEM OUT THIS AFTERNOON...BUT IT
APPEARS TO HAVE THE LOW LEVEL MOISTURE FARTHER NORTH OVER LAKE
SUPERIOR THAN WHAT IS ACTUALLY OCCURRING. THE MORE OPTIMISTIC
RUNS...WHICH SEEM TO HAVE A BETTER HANDLE ON THE LOCATION OF THE
LOW CLOUDS ARE THE 00Z GFS/ECMWF. THEY HOLD ONTO THE LOW CLOUDS
OVER THE NORTH CENTRAL AND WEST FOR THE FIRST PART OF THE MORNING
AND THEN SCATTER THEM OUT THROUGH THE LATER PART OF THE MORNING AND
EARLY AFTERNOON. WILL FOLLOW THAT IDEA AT THIS POINT FOR THE CLOUD
COVER FORECAST FOR TODAY. MEANWHILE OVER THE EAST...THE ADVECTION
OF THE DRIER AIR AND LITTLE UPSLOPE HELP SHOULD ALLOW THE LOW
CLOUDS TO DISSIPATE DURING THE FIRST PART OF THE MORNING. THAT DRY
AIR HAS ALREADY SCATTERED THE CLOUDS OUT OVER LUCE COUNTY AND
STARTING TO SEE IT WORK INTO ALGER/SCHOOLCRAFT COUNTIES. AS FOR
HIGHS TODAY...EXPECT THEM TO BE IN THE MID-UPPER 20S OVER MUCH OF
THE AREA.
FOLLOWING THE IDEA OF THE CLOUDS DIMINISHING TODAY...WOULD EXPECT A
VERY GOOD RADIATIONAL COOLING NIGHT TONIGHT UNDER THE CENTER OF THE
HIGH. THUS...WILL CONTINUE THE IDEA OF GOING AT OR BELOW THE
COLDEST GUIDANCE. THE GEM MODELS USUALLY PERFORM WELL IN
RADIATIONAL COOLING NIGHTS AND THEY HAVE LOWS IN THE LOWER SINGLE
DIGITS WHERE THEY ARE NOT INDICATING CLOUDS (ALTHOUGH THE REGIONAL
GEM REDEVELOPS LOW CLOUDS OVER THE HIGHER TERRAIN OF THE NORTH
CENTRAL TONIGHT). THUS...HAVE LOWS IN THE SINGLE DIGITS ABOVE ZERO
TO AROUND ZERO OVER THE INTERIOR LOCATIONS. WITH KCMX DROPPING TO 6
DEGREES AT 3AM THIS MORNING...THAT SUPPORTS TO EXPECTATIONS FOR
TONIGHT. THIS EXPECTED DROP IN TEMPS WILL LEAD TO THE POTENTIAL FOR
PATCHY FREEZING FOG OR AT LEAST SOME SOLID FROST. WITH DEWPOINTS IN
THE MID-UPPER TEENS TODAY...TEMPS SHOULD EASILY DROP THROUGH THOSE
VALUES THIS EVENING. DEWPOINTS THIS PAST EVENING AT KCMX WERE
SIMILAR TO WHAT IS EXPECTED ACROSS THE REST OF THE AREA THIS
AFTERNOON. WITH THEIR QUICK TEMP DROP AND LIGHT WINDS...THEY HAVEN/T
EXPERIENCED ANY FOG AT THIS POINT...BUT THE ICE ACCRETION ALGORITHM
DID INDICATE SOME ICE ACCUMULATION. THIS IS LIKELY DUE TO THAT QUICK
DROP AND IN TURN SOME QUICK/HARD FROST ON THE SENSOR. IT WILL BE
INTERESTING TO SEE IF ANY VERY SHALLOW FOG DEVELOPS AT KCMX OVER
THE NEXT COUPLE HOURS...AS IT WILL FORESHADOW WHAT WILL OCCUR
TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 514 AM EST THU DEC 18 2014
FRIDAY...A DRY AIRMASS ASSOCIATED WITH THE DEPARTING AREA OF
HIGH PRESSURE WILL LEAVE PARTLY TO MOSTLY SUNNY SKIES ACROSS UPPER
MICHIGAN. HOWEVER...THERE IS SOME UNCERTAINTY WHETHER MOISTURE
BENEATH THE PROMINENT 925 MB INVERSION WILL LINGER ENOUGH FOR MOSTLY
CLOUDY SKIES...ESPECIALLY OVER THE WEST. EVEN WITH SOME
CLOUDS...TEMPS ARE EXPECTED TO CLIMB INTO THE UPPER 20S.
FRI NIGHT...TEMPS SHOULD DROP OFF QUICKLY IN THE EVENING BUT MAY
REBOUND LATE AS CLOUDS INCREASE WITH STRENGTHENING 850 MB WAA AND
ASSOCIATED 280K ISENTROPIC ASCENT. WITH THE MID LEVEL REMAINING
DRY...NO PCPN IS EXPECTED.
SAT...AS THE SFC HIGH SLOWLY BUILDS INTO THE ERN LAKES...SRLY WINDS
WILL BRING WARMER AIR INTO THE REGION WITH TEMPS CLIMBING SLIGHTLY
ABOVE NORMAL WITH MAX READINGS CLIMB TO AROUND 30 DESPITE THE
THICKENING CLOUDS.
SUN...AS A MID LEVEL TROUGH DEVELOPS ACROSS THE CENTRAL CONUS...THE
MODELS SUGGEST POTENTIAL FOR A WEAK SHORTWAVE AND AREA OF MORE
SUBSTANTIAL 290K ISENTROPIC LIFT THAT COULD PRODUCE SOME LIGHT SNOW.
THE DYNAMICS REMAIN WEAK ENOUGH TO SUPPORT ONLY SLIGHT CHANCE POPS.
CONTINUED WAA WILL NUDGE MAX TEMPS INTO THE LOWER 30S.
MON-WED...ALTHOUGH THERE IS GENERAL MODEL AGREEMENT THAT A MID LEVEL
TROUGH WILL DEEPEN OVER THE NORTHERN GREAT LAKES...THERE ARE
CONSIDERABLE DIFFERENCES IN THE DETAILS OF HOW THE SHORTWAVES DIVING
INTO THE TROUGH WILL INTERACT AND HOW THAT WILL INFLUENCE
THE POSITION/STRENGTH OF THE SFC FEATURES. SNOW CHANCES INCREASE
FROM MON INTO MON NIGHT AS THE INITIAL LOW MOVES THROUGH THE UPPER MS
VALLEY. ENOUGH WARM AIR MAY BE DRAWN NORTHWARD TO BRING POTENTIAL FOR
SOME RAIN INTO THE EAST HALF. THE PREFERRED/MORE CONSISTENT 00Z/12Z
ECMWF KEEP THE LOW AND WARMER AIR SLIGHTLY FARTHER TO THE
SOUTH...MINIMIZING CHANCES FOR RAIN. THE LARGER DISPARITIES DEVELOP
BY WED WITH THE HANDLING OF A STRONGER SHRTWV THAT WOULD SUPPORT
RAPID DEEPENING OF THE SFC LOW. THE 18Z/00Z GFS AND 00Z ECMWF HAVE
BACKED OFF FROM THE VERY STRONG LOW MOVING INTO THE CNTRL LAKE AND
THEN NORTHWARD TOWARD JAMES BAY AND HAVE SHIFTED THE STRONGER LOW
THROUGH THE NORTHEAST CONUS. HOWEVER...IT WOULD NOT BE SURPRISING TO
SEE THE MODELS REVERT BACK TO THE STRONGER LOW THROUGH LOWER MI. WITH
SO MUCH UNCERTAINTY AND HIGH ENSEMBLE/MODEL SPREAD...THE FCST
MAINTAINS HIGHER END SNOW CHANCES BUT WITH LESS EMPHASIS FOR NOW ON
THE POTENTIAL FOR HEAVY SNOW AND HIGH WINDS UNTIL FCST CONFIDENCE IS
HIGHER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1224 AM EST THU DEC 18 2014
SKIES HAVE ALREADY CLEARED OUT AT KCMX AS DRY AIR ARRIVES FROM THE
NORTH. LINGERING FLURRIES WILL END EARLY THIS MORNING AT KIWD AND
KSAW...BUT LOW MVFR CIGS SHOULD REMAIN AS MOISTURE IS TRAPPED BELOW
STRENGTHENING INVERSION. EXPECT SKIES TO GRADUALLY CLEAR AT BOTH
SITES BY THIS AFTERNOON DUE TO MIXING OUT OF THE SHALLOW MOIST
LAYER. RISK OF FREEZING FOG TONIGHT AT MAINLY KSAW AND POSSIBLY
KCMX. DID LEAVE OUT OF TAFS ATTM THOUGH AS GREATEST CHANCE OF VSBY
REDUCTION AND ICE DEPOSITION SHOULD NOT OCCUR UNTIL AFTER END OF TAF
PERIOD LATER ON THURSDAY NIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 403 AM EST THU DEC 18 2014
HIGH PRESSURE BUILDING INTO THE UPPER GREAT LAKES REGION TODAY AND
TONIGHT WILL DIMINISH THE NORTHERLY WINDS BELOW 15KTS. THE HIGH
WILL BEGIN TO SHIFT TO THE EAST OF THE REGION ON FRIDAY AND ALLOW
WINDS TO GRADUALLY TURN TO THE SOUTH THROUGH FRIDAY NIGHT. A NEARLY
STATIONARY TROUGH IN THE LEE OF THE NORTHERN ROCKIES THIS WEEKEND
WILL KEEP THE SOUTH TO SOUTHWESTERLY WINDS IN PLACE AND GENERALLY
UNDER 20KTS. THIS TROUGH WILL GIVE WAY TO A DEVELOPING LOW THAT
WILL MOVE INTO THE NORTHERN PLAINS SUNDAY NIGHT AND THE UPPER
MISSISSIPPI VALLEY ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...JLB
AVIATION...JLA
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
403 AM EST THU DEC 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM EST THU DEC 18 2014
AN UPPER RIDGE STRETCHING FROM MINNESOTA THROUGH NORTHWEST ONTARIO
WILL BE THE MAIN FEATURE CONTROLLING THE WEATHER OVER THE UPPER
GREAT LAKES REGION OVER THE NEXT 24 HOURS. BENEATH THIS UPPER
RIDGE...A 1029MB SURFACE HIGH SITS JUST TO THE NORTH OF THE
MINNESOTA WHILE THE SURFACE TROUGH THAT LED TO THE SNOW YESTERDAY
IS OVER NORTHERN LAKE MICHIGAN AND NORTHERN LOWER MICHIGAN AND
WEAKENING. NORTH-NORTHEASTERLY FLOW AROUND THIS HIGH HAS PULLED
DRIER AIR INTO THE UPPER GREAT LAKES REGION...LEADING TO CLEARING
SKIES THIS PAST EVENING OVER MUCH OF LAKE SUPERIOR. BUT MOISTURE
TRAPPED BELOW THE SUBSIDENCE INVERSION...AND COMBINED WITH UPSLOPE
FLOW...HAS LED TO LOW CLOUDS PERSISTING OVER A GOOD PORTION OF
UPPER MICHIGAN EARLY THIS MORNING. THERE ARE A COUPLE SPOTS WHERE
THE CLOUDS DID CLEAR OUT...GENERALLY OVER THE KEWEENAW PENINSULA
AND ALSO IT/S STARTING TO OVER THE EAST. WHERE SKIES CLEARED
OUT...3AM TEMPERATURES ARE IN THE SINGLE DIGITS ABOVE ZERO (6
DEGREES AT KCMX)...WHILE THE CLOUDS HAVE KEPT THE TEMPERATURES IN
THE UPPER TEENS AND LOWER 20S ELSEWHERE. STILL SEEING LIGHT
FLURRIES HERE AT OUR OFFICE AT 330AM...SO WILL CONTINUE TO MENTION
ISOLATED FLURRIES IN THE FORECAST FOR THE UPSLOPE LOCATIONS THROUGH
DAYBREAK.
WITH THE UPPER RIDGE AND SURFACE HIGH MOVING OVER THE AREA
TODAY...EXPECT CONTINUED QUIET CONDITIONS FOR THE SHORT TERM
PERIOD. THERE ARE TWO AREAS OF FOCUS IN THE SHORT TERM
PERIOD...FIRST THE LOW CLOUDS AND THEIR DIMINISHMENT AND THEN THE
POTENTIAL FOR SOME FREEZING FOG OVERNIGHT TONIGHT. FOR THE LOW
CLOUDS...KMQT VWP INDICATES CLOUD TOPS AROUND 2.5KFT...WHICH
MATCHES UP WELL WITH THE INVERSION INDICATED ON THE MODELS AT
900MB. THE BIG QUESTION IS WHEN WILL THEY DISSIPATE TODAY. AT
THIS TIME OF THE YEAR WITH THE LOW SUN ANGLE AND LIMITED
MIXING...THERE IS LITTLE DAY TIME HELP AND WILL NEED TO RELY ON THE
ADVECTION OF DRIER AIR INTO THE AREA. UNFORTUNATELY...THIS IS WHERE
THE MODELS TEND TO DIFFER. THE 00Z NAM HOLDS ONTO THE CLOUDS FOR
MUCH OF THE DAY AND EVEN THROUGH THE NIGHT TONIGHT...BUT THINK THAT
IS LARGELY TIED TO IT TRADITIONALLY OVER DOING LOW LEVEL MOISTURE.
THAT APPEARS TO THE CASE EARLY THIS MORNING...WHERE IT HAS THE LOW
CLOUDS JUST TO THE WEST OF JAMES BAY BEING MUCH FARTHER TO THE
SOUTH AND SUPPOSEDLY ENTERING NORTHERN LAKE SUPERIOR AT THIS TIME.
THE RECENT RAP (ALONG WITH THE HRRR) RUNS ALSO HOLD ONTO THE CLOUDS
FOR MUCH OF THE DAY BEFORE CLEARING THEM OUT THIS AFTERNOON...BUT IT
APPEARS TO HAVE THE LOW LEVEL MOISTURE FARTHER NORTH OVER LAKE
SUPERIOR THAN WHAT IS ACTUALLY OCCURRING. THE MORE OPTIMISTIC
RUNS...WHICH SEEM TO HAVE A BETTER HANDLE ON THE LOCATION OF THE
LOW CLOUDS ARE THE 00Z GFS/ECMWF. THEY HOLD ONTO THE LOW CLOUDS
OVER THE NORTH CENTRAL AND WEST FOR THE FIRST PART OF THE MORNING
AND THEN SCATTER THEM OUT THROUGH THE LATER PART OF THE MORNING AND
EARLY AFTERNOON. WILL FOLLOW THAT IDEA AT THIS POINT FOR THE CLOUD
COVER FORECAST FOR TODAY. MEANWHILE OVER THE EAST...THE ADVECTION
OF THE DRIER AIR AND LITTLE UPSLOPE HELP SHOULD ALLOW THE LOW
CLOUDS TO DISSIPATE DURING THE FIRST PART OF THE MORNING. THAT DRY
AIR HAS ALREADY SCATTERED THE CLOUDS OUT OVER LUCE COUNTY AND
STARTING TO SEE IT WORK INTO ALGER/SCHOOLCRAFT COUNTIES. AS FOR
HIGHS TODAY...EXPECT THEM TO BE IN THE MID-UPPER 20S OVER MUCH OF
THE AREA.
FOLLOWING THE IDEA OF THE CLOUDS DIMINISHING TODAY...WOULD EXPECT A
VERY GOOD RADIATIONAL COOLING NIGHT TONIGHT UNDER THE CENTER OF THE
HIGH. THUS...WILL CONTINUE THE IDEA OF GOING AT OR BELOW THE
COLDEST GUIDANCE. THE GEM MODELS USUALLY PERFORM WELL IN
RADIATIONAL COOLING NIGHTS AND THEY HAVE LOWS IN THE LOWER SINGLE
DIGITS WHERE THEY ARE NOT INDICATING CLOUDS (ALTHOUGH THE REGIONAL
GEM REDEVELOPS LOW CLOUDS OVER THE HIGHER TERRAIN OF THE NORTH
CENTRAL TONIGHT). THUS...HAVE LOWS IN THE SINGLE DIGITS ABOVE ZERO
TO AROUND ZERO OVER THE INTERIOR LOCATIONS. WITH KCMX DROPPING TO 6
DEGREES AT 3AM THIS MORNING...THAT SUPPORTS TO EXPECTATIONS FOR
TONIGHT. THIS EXPECTED DROP IN TEMPS WILL LEAD TO THE POTENTIAL FOR
PATCHY FREEZING FOG OR AT LEAST SOME SOLID FROST. WITH DEWPOINTS IN
THE MID-UPPER TEENS TODAY...TEMPS SHOULD EASILY DROP THROUGH THOSE
VALUES THIS EVENING. DEWPOINTS THIS PAST EVENING AT KCMX WERE
SIMILAR TO WHAT IS EXPECTED ACROSS THE REST OF THE AREA THIS
AFTERNOON. WITH THEIR QUICK TEMP DROP AND LIGHT WINDS...THEY HAVEN/T
EXPERIENCED ANY FOG AT THIS POINT...BUT THE ICE ACCRETION ALGORITHM
DID INDICATE SOME ICE ACCUMULATION. THIS IS LIKELY DUE TO THAT QUICK
DROP AND IN TURN SOME QUICK/HARD FROST ON THE SENSOR. IT WILL BE
INTERESTING TO SEE IF ANY VERY SHALLOW FOG DEVELOPS AT KCMX OVER
THE NEXT COUPLE HOURS...AS IT WILL FORESHADOW WHAT WILL OCCUR
TONIGHT.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 354 PM EST WED DEC 17 2014
QUIET WEATHER IS EXPECTED THROUGH THE WEEKEND BEFORE AN ACTIVE
PATTERN DEVELOPS ACROSS THE GREAT LAKES REGION NEXT WEEK. THIS
INCLUDES THE POTENTIAL FOR A DISRUPTIVE SYSTEM LATE TUESDAY INTO
CHRISTMAS DAY.
THURSDAY NIGHT THROUGH SUNDAY...MID-LEVEL RIDGING STRETCHING FROM
THE NORTHERN PLAINS INTO NORTH-CENTRAL CANADA TODAY WILL BE DRIFTING
EASTWARD ACROSS THE UPPER GREAT LAKES AT THE BEGINNING OF THE
PERIOD. THE ASSOCIATED SFC RIDGE AXIS IS FORECAST TO BE OVER UPPER
MI THURSDAY NIGHT...SETTING THE STAGE FOR A RATHER CHILLY NIGHT.
DRIER AIR FILTERING IN FROM THE NORTH ON THURSDAY WILL SLOWLY ERODE
CLOUDS TRAPPED UNDER A 1-2KFT INVERSION. VEERING SFC WINDS MAY BRING
LOW CLOUDS BACK INTO THE AREA...BUT NOT UNTIL LATER THURSDAY NIGHT.
WITH A RELATIVELY FRESH SNOW PACK AND LIGHT WINDS...TEMPS LOOK TO
FALL TO NEAR ZERO FOR INTERIOR LOCATIONS TO THE MID TEENS FOR
SHORELINE LOCATIONS. WENT BELOW NEARLY ALL GUIDANCE. FREEZING FOG
WILL BE A POSSIBILITY FOR THE WEST AND CENTRAL INTERIOR FROM THE
GOOD RADIATIONAL COOLING AND RESIDUAL SFC MOISTURE UNDER THE
SHALLOW INVERSION.
AFTER A MOSTLY SUNNY DAY FOR AT LEAST THE EAST HALF ON
FRIDAY...CLOUDS WILL GRADUALLY INCREASE FROM THE WEST AS A WEAK
SHORTWAVE TROUGH ALONG THE U.S./CANADIAN BORDER MOVES TOWARD THE
UPPER GREAT LAKES. WITH LITTLE FORCING AND ONLY MODEST
MOISTURE...ONLY CLOUDS ARE EXPECTED FOR SATURDAY AND SUNDAY.
SUNDAY NIGHT THROUGH WEDNESDAY...A RATHER EXTENDED PERIOD OF
UNSETTLED WEATHER IS EXPECTED TO BEGIN BY THIS POINT. A SECONDARY
TROUGH DIGGING INTO THE NORTHERN HIGH PLAINS ON SATURDAY WILL
REINFORCE THE DECAYING LEAD TROUGH OVER THE UPPER MS VALLEY BY
SUNDAY AFTERNOON. LOW-LEVEL WAA AND FGEN COMBINED WITH DEEPER
MOISTURE AND MID-LEVEL FORCING WILL BE ENOUGH TO INDUCE SOME LIGHT
PRECIP ACROSS THE CWA LATE SUNDAY AFTERNOON INTO MONDAY. THERE IS
SOME DIFFERENCE ON HOW THE MODELS HANDLE THE PHASING OF THE TROUGHS
AT THIS POINT...WITH THE 12Z GFS SHOWING A SOMEWHAT STRONGER
SOLUTION. EITHER WAY...DEEPER MOISTURE WILL BE ADVECTING INTO THE
REGION...BUT WILL BE LESS THAN IDEAL FOR WIDESPREAD PRECIP. WILL
KEEP THE CONSENSUS BLEND OF CHANCE POPS FOR MUCH OF THE CWA LATE
SUNDAY AFTERNOON THROUGH MONDAY.
A LOT OF UNCERTAINTY GETS INFUSED INTO THE FORECAST BEGINNING MONDAY
NIGHT AS A THIRD...QUICK-MOVING...SHORTWAVE TRACKS ESE OUT OF THE
PACIFIC NW. HOW THIS TROUGH INTERACTS WITH THE EXISTING TROUGHS OVER
THE UPPER GREAT LAKES IS RATHER UNCLEAR AT THIS TIME. HOWEVER...THE
CONGLOMERATION OF THE TROUGHS WILL INDUCE A STRONG SFC LOW OVER THE
REGION BY CHRISTMAS EVE. BOTH THE ECMWF AND GFS ARE ADVERTISING A
LOW AS DEEP AS 960MB OVER LAKE HURON WEDNESDAY EVENING.
WHILE WIDESPREAD SNOW LOOKS FAIRLY CERTAIN MONDAY NIGHT INTO
CHRISTMAS...THE INTENSITY WILL REMAIN IN QUESTION FOR SOME TIME AS
GUIDANCE IS MIXED ON HOW THE SYNOPTIC PRECIP PATTERNS EVOLVE. ALL
THE LONG RANGE MODELS BRING ENERGY FROM THE FIRST TWO SHORTWAVES
NORTHEASTWARD ACROSS THE REGION LATE MONDAY NIGHT INTO TUESDAY. THIS
WOULD RESULT IN A QUICK ROUND OF MODERATE WET SNOW DURING THAT TIME
PERIOD.
TUESDAY NIGHT INTO WEDNESDAY MORNING MAY HAVE A BRIEF LULL IN PRECIP
BEFORE THE RAPIDLY DEEPENING LOW QUICKLY MOVES NORTHWARD OUT OF THE
OHIO VALLEY. THIS WOULD BRING INCREASING CHANCES OF MODERATE TO
HEAVY SNOW BY WEDNESDAY NIGHT. HOWEVER...LOW-LEVEL CAA WILL LAG THE
MAIN SYNOPTIC MOISTURE...REDUCING LAKE-ENHANCEMENT. EITHER WAY...A
1030MB HIGH PUSHING IN ON THE BACKSIDE OF THE LOW WILL RESULT IN
STRONG N/NNW WINDS BEGINNING WEDNESDAY AFTERNOON. WITH LAKE
EFFECT KICKING IN AS COLDER AIR FINALLY ARRIVES...CONDITIONS COULD
BE QUITE POOR FOR TRAVEL CHRISTMAS DAY.
SIMPLY PUT...THE SYSTEM LOOKS LIKE A DRAWN-OUT MESS FOR THE UPPER
GREAT LAKES TUESDAY INTO CHRISTMAS. STAYED TUNED...AS PLENTY OF
FORECAST CHANGES WILL LIKELY OCCUR OVER THE NEXT SEVERAL DAYS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1224 AM EST THU DEC 18 2014
SKIES HAVE ALREADY CLEARED OUT AT KCMX AS DRY AIR ARRIVES FROM THE
NORTH. LINGERING FLURRIES WILL END EARLY THIS MORNING AT KIWD AND
KSAW...BUT LOW MVFR CIGS SHOULD REMAIN AS MOISTURE IS TRAPPED BELOW
STRENGTHENING INVERSION. EXPECT SKIES TO GRADUALLY CLEAR AT BOTH
SITES BY THIS AFTERNOON DUE TO MIXING OUT OF THE SHALLOW MOIST
LAYER. RISK OF FREEZING FOG TONIGHT AT MAINLY KSAW AND POSSIBLY
KCMX. DID LEAVE OUT OF TAFS ATTM THOUGH AS GREATEST CHANCE OF VSBY
REDUCTION AND ICE DEPOSITION SHOULD NOT OCCUR UNTIL AFTER END OF TAF
PERIOD LATER ON THURSDAY NIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 403 AM EST THU DEC 18 2014
HIGH PRESSURE BUILDING INTO THE UPPER GREAT LAKES REGION TODAY AND
TONIGHT WILL DIMINISH THE NORTHERLY WINDS BELOW 15KTS. THE HIGH
WILL BEGIN TO SHIFT TO THE EAST OF THE REGION ON FRIDAY AND ALLOW
WINDS TO GRADUALLY TURN TO THE SOUTH THROUGH FRIDAY NIGHT. A NEARLY
STATIONARY TROUGH IN THE LEE OF THE NORTHERN ROCKIES THIS WEEKEND
WILL KEEP THE SOUTH TO SOUTHWESTERLY WINDS IN PLACE AND GENERALLY
UNDER 20KTS. THIS TROUGH WILL GIVE WAY TO A DEVELOPING LOW THAT
WILL MOVE INTO THE NORTHERN PLAINS SUNDAY NIGHT AND THE UPPER
MISSISSIPPI VALLEY ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KLUBER
AVIATION...JLA
MARINE...SRF
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1120 PM CST WED DEC 17 2014
.SYNOPSIS...
ISSUED AT 325 PM CST WED DEC 17 2014
AN ACTIVE H5 PATTERN CONTINUES ACROSS THE LOWER 48 TDY
WITH NUMEROUS DISTURBANCES AND A CLOSED LOW NOTED OVER THE CONUS.
CLOSED LOW PRESSURE WAS NOTED OVER LAKE HURON AND EXTENDED WWD INTO
NRN WISCONSIN. HIGH PRESSURE WAS NOTED OVER NRN MANITOBA. ACROSS THE
WESTERN HALF OF THE CONUS...SHORTWAVES WERE NOTED OVER SERN
MT....SWRN NEW MEXICO...AND THE CALIFORNIA DESERT. HT FALLS OF 50 TO
70 METERS EXTENDED FROM EASTERN ARIZONA INTO SWRN KS. IN ASSOCIATION
WITH THE CLOSED LOW OVER THE GREAT LAKES...A NICE 50 TO 90 KT JET
STREAK EXTENDED FROM THE MID MISSOURI RIVER...EAST TO VIRGINIA AND
NORTH CAROLINA. HT FALLS IN ASSOCIATION WITH THE CLOSED LOW WERE
MOST PRONOUNCED OVER NEW ENGLAND...WHERE 50 TO 120 METER FALLS WERE
NOTED. AT THE SURFACE...ARCTIC HIGH PRESSURE WAS ANCHORED ACROSS THE
EASTERN DAKOTAS...SSE INTO MISSOURI. WEST OF THIS FEATURE...WEAK
SERLY WINDS WERE NOTED ALONG WITH PESKY LOW LEVEL CLOUDINESS AND
PATCHY FOG. TEMPERATURES THIS AFTERNOON WERE COLD WITH READINGS IN
THE LOWER 20S ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 325 PM CST WED DEC 17 2014
DESPITE THE MAIN UPPER PV ANOMALY AND ASSOCIATED LARGE SCALE FORCING
IS SOUTH OF THE AREA AND MOVING EASTWARD...SEVERAL FORECASTING
ISSUES REMAIN. THE STRATUS LAYER IS WARM ENOUGH TO CONTAIN
SUPERCOOLED LIQUID AND HENCE FALL TO THE GROUND IN WEAK UPSLOPE FLOW
AS FREEZING DRIZZLE IN SOME AREAS OF SOUTHWEST NEBRASKA THIS
AFTERNOON. RAP BUFR SOUNDINGS SUGGEST MINIMAL LIFT THROUGH THE
REMAINING AFTERNOON HOURS...BUT INCREASING SLIGHTLY THIS EVENING AND
OVERNIGHT. IR SAT PICS SHOW MID LEVEL CLOUDS TRYING TO MOVE OVER THE
TOP OF THE EXISTING LOW LEVEL STRATUS BUT HAVING A HARD TIME AS MID
LEVELS ARE QUITE DRY INITIALLY. BELIEVE THE INCREASING UPWARD
VERTICAL MOTION AS A RESULT OF WEAK MID LEVEL FRONTOGENESIS WILL
EVENTUALLY HELP TO MOISTEN THE MID LEVELS...BUT SOUNDINGS STILL SHOW
TOO MUCH DRY AIR TO CONNECT A SATURATED SNOW PRODUCING LAYER WITH
THE MOIST LOW LEVELS BELOW. THE END RESULT...BASED ON FORECAST
SOUNDINGS...WILL BE FREEZING DRIZZLE ESPECIALLY ACROSS THE SOUTHWEST
PORTION OF NEBRASKA THIS EVENING AND DURING THE OVERNIGHT. NEAR TERM
ENSEMBLES SUGGEST THE POSSIBILITY OF A SMALL BAND OF LIGHT SNOW FROM
SOUTHEAST FRONTIER COUNTY NORTHEASTWARD INTO CUSTER...BUT CONFIDENCE
IN SUCH A SMALL SCALE FEATURE BEING ABLE TO FULLY SATURATE THE
ATMOSPHERIC COLUMN TO SUPPORT LIGHT SNOW IS NOT HIGH...SO HAVE LEFT
PRECIPITATION MENTION AS FREEZING DRIZZLE FOR NOW.
FURTHER NORTH AND WEST...SOUTHERLY AND SOUTHEASTERLY WINDS WILL
CONTINUE TO SUSTAIN MOIST LOW LEVELS IN THE EASTERN PANHANDLE...BUT
MID AND UPPER LEVEL DRYING WILL BE GREATER HERE WHICH LEAVES A
BETTER SCENARIO FOR FOG AND HAVE THEREFORE INCLUDED THAT MENTION
THERE INTO THE MORNING HOURS. FOG WILL BE OCCURRING IN SNOW COVERED
AREAS WHICH WILL MEAN SOME DEPOSITION ON ROADS WILL BE POSSIBLE SO
THE MENTION OF FREEZING FOG WAS INCLUDED.
TOMORROW AFTERNOON CLOUDS WILL THIN ALTHOUGH STILL HAVE MUCH OF THE
AREA WITH A SNOW PACK. THIS WILL LIMIT THE ABILITY TO WARM...WITH
TEMPS STRUGGLING TO REACH FREEZING. SOME PARTIAL SUN IS EXPECTED
ACROSS WESTERN NEBRASKA THANKS TO SOME WESTERLY DOWNSLOPING WINDS
WHICH IS WHERE FORECAST HIGHS ARE THE WARMEST.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 325 PM CST WED DEC 17 2014
MID RANGE...THURSDAY NIGHT THROUGH SATURDAY...THE MAIN
FORECAST CHALLENGES IN THE MID RANGE ARE THE THREAT FOR FREEZING
DRIZZLE THURSDAY NIGHT INTO FRIDAY MORNING...AS WELL AS CLOUD COVER
AND TEMPERATURES. FOR THURSDAY NIGHT...WITH THE EXCEPTION OF THE FAR
NORTHWESTERN CWA...LOW CLOUDS AND AN ARCTIC DRAPE WILL REMAIN
ENTRENCHED ACROSS THE BULK OF THE FORECAST AREA. BOTH THE NAM AND
GFS SOLNS THIS MORNING PER FCST SOUNDINGS ARE INDICATING A NICE
LAYER OF NEAR 100 PERCENT RH FROM THE SURFACE TO 1000 TO 1500FT AGL.
WITHIN THIS LAYER...WEAK VEERING OF THE WINDS ARE PRESENT ALONG WITH
SOME WEAK OMEGA AND TEMPERATURES RANGING FROM ZERO TO -5C IN THIS
MOIST LAYER. IN ADDITION...WARMING AND DRYING IS INDICATED PER
FORECAST SOUNDINGS ABOVE THE MOIST LAYER DURING THE PERIOD. ALL
TOLD...THIS IS A DECENT SETUP FOR FREEZING DRIZZLE AND HAVE
INTRODUCED IT IN THE GRIDS. DURING THE EVENING HOURS...WITH THE
EXCEPTION OF THE PANHANDLE COUNTIES AND FAR NORTHWEST...CONDS WILL
BE FAVORABLE FOR FZDZ. THIS AREA WILL SHRINK EAST INTO THE OVERNIGHT
HOURS AND MORNING PERIOD FOR FRIDAY. BY FRIDAY AFTERNOON...MOSTLY
CLEAR SKIES IN THE CENTRAL AND WEST...AND PARTLY CLOUDY SKIES IN THE
EAST ARE EXPECTED. THIS WILL ALLOW TEMPS TO REACH THE LOWER TO
MIDDLE 30S FRIDAY...EFFECTIVELY ENDING THE FREEZING DRIZZLE THREAT.
ON FRIDAY NIGHT AND SATURDAY...FORECAST SOUNDINGS OVER THE EASTERN
THIRD OF THE FORECAST AREA ARE INDICATIVE OF ANOTHER EPISODE OF
FREEZING DRIZZLE LATE FRIDAY NIGHT INTO SATURDAY MORNING. ATTM...THE
THREAT FOR FREEZING DRIZZLE IS INDICATED ONLY IN THE NAM SOLN AS THE
GFS IS MORE AGGRESSIVE IN PUSHING THE ARCTIC AIRMASS EAST FRIDAY
NIGHT. GIVEN THE MODEL DIFFERENCES...WILL HOLD OFF ON MENTION OF
FREEZING DRIZZLE ATTM. ON SATURDAY...AN UPPER LEVEL DISTURBANCE
ACROSS THE NRN TIER OF STATES...WILL FORCE WARMER AIR INTO THE
FORECAST AREA...FOLLOWED BY A WEAK COOL FRONT SATURDAY NIGHT. LIGHT
WESTERLY WINDS SATURDAY WILL PUSH HIGHS INTO THE LOWER 40S.
SUNDAY THROUGH WEDNESDAY...AS THE UPPER LEVEL SYSTEM PUSHES EAST
MONDAY AND MONDAY NIGHT...THERE WILL BE AN INCREASED THREAT FOR LIGHT
PRECIPITATION IN THE FAR NORTHEAST...ALONG WITH A THREAT FOR
PRECIPITATION ACROSS THE CENTRAL AND NORTHERN ROCKIES...WHICH WILL
BE ENHANCED BY A STRONG UPPER LEVEL JET STREAK. BEYOND MONDAY
NIGHT...A DRY AND COLDER FORECAST IS EXPECTED ACROSS WESTERN AND
NORTH CENTRAL NEBRASKA AS ARCTIC AIR PUSHES SOUTH TUESDAY INTO
WEDNESDAY. ATTM...THE BEST THREAT FOR SNOW WILL BE OFF TO THE WEST
OF THE FORECAST AREA...HOWEVER...WE WILL NEED TO MONITOR NEXT
THURSDAY INTO NEXT WEEKEND AS THE LATEST ECMWF SOLN DIGS A DEEP
TROUGH INTO THE INTERMOUNTAIN WEST BY DAY 10.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1120 PM CST WED DEC 17 2014
A CLEARING LINE SHOULD BECOME ESTABLISHED ALONG OR NEAR HIGHWAY 83
THURSDAY.
LIFR/IFR CIGS AND VSBY CONTINUE OVERNIGHT AND IMPROVE TO VFR 18Z-
21Z ALONG AND WEST OF HIGHWAY 61. LIFR/IFR/MVFR CIGS CONTINUE ALONG
AND EAST OF HIGHWAY 83 THROUGH THURSDAY EVENING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...MASEK/JWS
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
853 PM PST WED DEC 17 2014
.SYNOPSIS...SCATTERED LIGHT RAIN SHOWERS AND MOUNTAIN SNOW SHOWERS
WILL DIMINISH OVERNIGHT AS A WEATHER SYSTEM SLOWLY MOVES ACROSS THE
DESERT SOUTHWEST. IMPROVING CONDITIONS ARE EXPECTED THURSDAY AND
FRIDAY. A FEW SHOWERS WILL BE POSSIBLE ACROSS THE GREAT BASIN OVER
THE WEEKEND FOLLOWED BY DRY AND WARMER WEATHER NEXT WEEK.
&&
.UPDATE...NOT A VERY WET STORM FOR OUR AREA, HOWEVER, THIS IS ONE OF
THE RARE MONTHS IN THE LAST FEW YEARS WITH ABOVE NORMAL
PRECIPITATION AND SO WE`LL TAKE WHATEVER WE CAN GET. MOST AREAS SAW
UNDER A QUARTER OF AN INCH OF PRECIPITATION WITH THIS EVENT AND THE
REALITY WAS ONLY A FEW HUNDREDTHS OF AN INCH AT MOST SPOTS. THE
EVENING SOUNDING SHOWED A SMALL MOIST LAYER BETWEEN 825 AND 725 MB
WHICH STILL SUPPORTS THE POTENTIAL FOR SOME PRECIPITATION TO REACH
THE GROUND THROUGH THE REST OF TONIGHT. OVERALL THE POP GRIDS LOOKED
OK, HOWEVER, THERE IS A SECOND PIECE OF ENERGY EXPECTED TO PUSH INTO
SOUTHEAST CALIFORNIA AND SOUTHERN NEVADA LATER TONIGHT THAT MAY SET
OFF SOME ADDITIONAL SHOWER ACTIVITY IN THE WESTERN CWFA. BOTH THE
WRF AND HRRR MODELS SUGGEST SOME SHOWER ACTIVITY WITH THIS FEATURE
ACROSS INYO, ESMERALDA AS WELL AS CENTRAL AND SOUTHERN NYE COUNTIES
AND POPS WERE ADJUSTED IN THESE AREAS FOR THE REST OF TONIGHT.
OTHERWISE THE FORECAST LOOKED IN GOOD SHAPE AND I WILL LEAVE IT BE.
&&
.AVIATION...FOR MCCARRAN...CEILINGS WILL HOVER AROUND 6 KFT BEFORE
PARTIALLY CLEARING AND LIFTING TO AROUND 10 KFT THURSDAY MORNING.
GENERALLY LIGHT WINDS WILL CONTINUE TONIGHT.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...CIGS OF 3K-6K FT AND MOUNTAIN OBSCURATIONS WILL
CONTINUE ACROSS MUCH OF THE REGION THROUGH THURSDAY MORNING
FOLLOWED BY PARTIAL CLEARING AS A WEAK WEATHER SYSTEM GRADUALLY
MOVES TO THE EAST.
&&
PREVIOUS DISCUSSION...
ISSUED 250 PM PST WED DEC 17 2014
.SHORT TERM...EXTENSIVE LOW TO MID LEVEL CLOUDS WERE APPARENT FROM
SATELLITE LOOPS AND SURFACE OBSERVATIONS ACROSS THE FORECAST AREA
AND THESE WILL BE SLOW TO CLEAR OUT TONIGHT THROUGH THURSDAY. RECENT
RADAR LOOPS SHOWED A SLIGHT UPWARD TREND IN SCATTERED SHOWERS ACROSS
SOUTHERN CLARK AND CENTRAL MOHAVE COUNTIES EARLY THIS AFTERNOON AND
THE HRRR MODEL INDICATES THIS WILL BE THE PRIMARY AREA FOR
PRECIPITATION THROUGH EARLY THIS EVENING. ANY ADDITIONAL SNOW
AMOUNTS IN THE MOUNTAINS OF SOUTHERN NEVADA AND NORTHWEST ARIZONA
ARE EXPECTED TO BE VERY LIGHT AND THE WINTER WEATHER ADVISORY HAS
BEEN CANCELLED. THE MEAN TROUGH OVER THE REGION WILL DIG A
LITTLE TONIGHT AS A SHORTWAVE WEST OF POINT CONCEPTION DIVES TOWARD
NORTHERN BAJA. AN ADDITIONAL BAND OF MOISTURE ASSOCIATED WITH THIS
SHORTWAVE WILL MOVE INTO THE SOUTHERN SIERRA OVERNIGHT AND WILL
PRODUCE A CHANCE OF VERY LIGHT SNOW OVER THE EASTERN SLOPES...SO
POPS WERE INCREASED ACCORDINGLY.
THE TROUGH AXIS WILL SHIFT EASTWARD THURSDAY WITH GRADUAL CLEARING
THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. LITTLE CHANGE IN
TEMPERATURES CAN BE EXPECTED.
&&
.LONG TERM...FRIDAY THROUGH TUESDAY.
MEDIUM RANGE MODELS SIMILAR TO 24 HOURS AGO INDICATING MOST OF THE
ENERGY ASSOCIATED WITH NEXT SHORTWAVE TROUGH WILL AFFECT CENTRAL
NEVADA NORTHWARD FRIDAY NIGHT INTO SATURDAY. WITH THAT SAID, LEFT IN
SLIGHT CHANCE POPS FROM NORTHERN INYO COUNTY EASTWARD TO NORTHERN
LINCOLN COUNTY TO ACCOUNT FOR ANY POTENTIAL SOUTHWARD SHIFT.
SUNDAY THROUGH TUESDAY THE LONGWAVE PATTERN WILL BE DOMINATED BY A
STRONG RIDGE ALONG THE WEST COAST WITH A TROUGH EAST OF THE ROCKIES.
SOUTHERN GREAT BASIN/MOJAVE DESERT WILL LIE UNDER A DRY NORTHWEST
FLOW. SURFACE HIGH DEVELOPING OVER THE NORTHERN GREAT BASIN WILL
LEAD TO AN INCREASE IN NORTH BREEZES DOWN THE COLORADO RIVER VALLEY
SOUTH OF HOOVER DAM SUNDAY-TUESDAY.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS TODAY THROUGH THURSDAY ACCORDING
TO STANDARD OPERATING PROCEDURES.
&&
$$
UPDATE/AVIATION...STACHELSKI
SHORT TERM...ADAIR
LONG TERM...PIERCE
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
102 AM EST THU DEC 18 2014
.SYNOPSIS...
AN UPPER LEVEL STORM SYSTEM MOVING FROM THE GREAT LAKES TO NEW
ENGLAND WILL RESULT IN SCATTERED SNOW SHOWERS CONTINUING INTO
THURSDAY. FARTHER SOUTH A FEW SPRINKLES AND FLURRIES CAN BE
EXPECTED IN NORTHEAST PENNSYLVANIA. CLOUDS AND SEASONABLY COLD
TEMPERATURES WILL PERSIST FRIDAY INTO THE WEEKEND WITH SCATTERED
SNOW SHOWERS GRADUALLY DIMINISHING.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
740 PM UPDATE...
AREA OF PCPN HAS WEAKENED ACRS CWA THIS EVNG. UPR LVL S/WV IS NOW
ROTATING INTO WRN NY AND BRINGING STEEPENING MID-LVL LR TO THE
REGION. THIS ADDED LIFT COMBINED WITH LK MOISTURE WL SERVE TO
INCRS CVRG OF SNOW SHOWERS FOR PORTION OF OVRNGT IN 290-300 FLOW
ON EITHER SIDE OF MIDNIGHT.
EXPECT THAT OVRNGT SNOW ACCUMS ARND 1.5 INCHES IN FAVORED
LOCATIONS WITH HIGHEST AMNTS IN THE HIGHER TERRAIN OF UPR
SUSQUEHANNA REGION. ONLY MINOR CHGS MADE TO POPS WITH NO OTHER
CHGS NEEDED AT THIS TIME. EXPECT THAT NEPA WL STAY CLDY BUT VRY
LITTLE PCPN EXPECTED TO SNEAK INTO ZONES TONIGHT.
PREV DISCUSSION BLO...
A BAND OF STEADY LIGHT RAIN IS MOVING EAST ACROSS CENTRAL NY THIS
AFTERNOON WITH A CHANGE-OVER TO LIGHT SNOW ALREADY OCCURRING OVER
THE HIGHER ELEVATIONS AS OF 3 PM. THIS BAND WILL LIFT EAST-
NORTHEAST TOWARD THE CATSKILLS AND MOHAWK VALLEY THROUGH LATE THIS
AFTERNOON WITH LOWER ELEVATIONS GRADUALLY MIXING WITH OR CHANGING
TO LIGHT SNOW AS COLDER AIR FILTERS IN FROM THE WEST. MEANWHILE...
MAINLY DRY WEATHER CAN BE EXPECTED TO CONTINUE IN THE WILKES-BARRE
AND SCRANTON AREAS AND POINTS SOUTH WITH PRECIPITATION REMAINING
TO THE NORTH.
PRECIPITATION SHOULD BECOME SPOTTIER AND LIGHTER EARLY THIS
EVENING IN MANY AREAS... THEN UPPER LEVEL LOW PRESSURE CURRENTLY
OVER WESTERN MICHIGAN WILL TRACK RAPIDLY EAST ACROSS THE AREA
LATER TONIGHT. THIS COULD RESULT IN A PERIOD OF ENHANCED SNOW
SHOWERS AGAIN LATE TONIGHT INTO EARLY THURSDAY MORNING. A BIT OF
LAKE ENHANCEMENT COULD ALSO OCCUR SOUTHEAST OF LAKE ONTARIO LATE
TONIGHT AS 850 MB TEMPERATURES FALL TO AROUND -8 C. LATEST HIGH
RESOLUTION NAM AND HRRR BOTH SUPPORT THE IDEA THAT SNOW SHOWERS
MAY INCREASE IN COVERAGE LATE TONIGHT WITH THE PASSAGE OF THIS
SYSTEM. BASED ON THIS HAVE UPPED POPS INTO THE LIKELY CATEGORY
LATER TONIGHT AND HAVE UP TO AN INCH OF SNOW POSSIBLE ESPECIALLY
AT HIGHER ELEVATIONS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
UPPER LEVEL AND SURFACE LOW PRESSURE WILL TRACK SLOWLY EAST ACROSS
THE SOUTHERN CANADIAN MARITIMES THURSDAY THROUGH FRIDAY. FLOW
ACROSS OUR AREA IN THE WAKE OF THIS SYSTEM WILL BE NORTHWESTERLY WITH
PLENTY OF LOW-LEVEL MOISTURE AND 850 MB TEMPERATURES HOLDING
AROUND -8 TO -10 C... WHICH WILL BE JUST COLD ENOUGH FOR A MINOR
LAKE RESPONSE IN THE NORTHWEST FLOW. HOWEVER MOISTURE WILL BECOME
INCREASINGLY SHALLOW WITH CONSIDERABLE DRYING IN THE -10 TO -20
DEGREE SNOW GROWTH ZONE BY THURSDAY AFTERNOON. BASED ON THIS
EXPECT JUST SCATTERED LIGHT SNOW SHOWERS THURSDAY AFTERNOON INTO
FRIDAY WITH ONLY MINIMAL ACCUMULATIONS. SOME FREEZING DRIZZLE
MIGHT EVEN OCCUR THURSDAY NIGHT ALTHOUGH AT THIS POINT I THINK
THAT IS A LOW PROBABILITY SCENARIO AND I HAVE NOT INCLUDED ZL IN
THE GRIDDED FORECAST. AT THIS POINT IT APPEARS THAT CLOUDS WILL
PERSIST THROUGH FRIDAY. WITH PLENTY OF CLOUDS WE ARE NOT EXPECTING
MUCH DIURNAL VARIATION IN TEMPERATURES THROUGH FRIDAY WITH HIGHS
MAINLY 30 TO 35 AND LOWS 20 TO 25 IN MOST PLACES.
BEST CHANCE TO SEE ANY SUNSHINE MIGHT BE EARLY SATURDAY BEFORE
CLOUDS AHEAD OF THE NEXT SYSTEM STREAM NORTHEAST ACROSS THE AREA
DURING THE AFTERNOON. SATURDAY SHOULD BE DRY WITH TEMPERATURES
AGAIN MAINLY IN THE 30S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
1 PM UPDATE..
FOLLOWED WPC GUIDANCE FOR THE MOST PART. SAT NGT AND SUN SOME
LIGHT SNOW WITH AN INVERTED TROF FROM A COASTAL STORM WELL OUT TO
SEA. SNOW ACCUMULATIONS WILL BE MOSTLY 2 INCHES OR LESS.
DRY SUN NGT AND MON WITH A MILD SFC HIGH. MON NGT AND TUE MODELS
NOW TRYING TO BRING A WEAK COASTAL STORM NE INTO THE AREA WITH
MIXED PRECIP. ADDED SOME LOW CHC POPS.
WED A STRONG OCCLUDED FRONT LIFTS NE AHEAD OF A LARGE BOMBING
STACKED LOW IN THE MIDWEST. WARM AIR SO PRECIP MOSTLY RAIN. THIS
WILL NEED TO BE WATCHED FIRST FOR RAIN AMOUNTS AND POSSIBLY
FLOODING AND SECOND FOR STRONG GUSTY WINDS.
ON THE TAIL END OF THE STEADY RAIN IT WILL CHANGE OVER TO SNOW WED
NGT AND STAY COLD THE REST OF THE WEEK WITH WRAP AROUND SNOW.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
06Z UPDATE...
UPPER WAVE IS NOW MOVING THROUGH DURING THE PREDAWN HOURS...WHICH
ALONG WITH LAKE MOISTURE WILL CAUSE A QUICK BURST OF -SHSN FOR THE
TERMINALS INCLUDING TEMPO IFR VIS FOR SEVERAL. BEYOND 10Z...WAVE
WILL BE ALREADY ZIPPING AWAY...WITH WNW FLOW AND STUBBORN MVFR DECK
IN ITS WAKE THROUGH THE REMAINDER OF TAF PERIOD /EXCEPT KAVP
PROBABLY LOSING IT TOWARDS 00Z/. IN MOST CASES...FUEL ALT MVFR
CIG. AS FOR -SHSN...WITH WAVE GONE IT BECOMES SIMPLY A QUESTION OF
LAKE EFFECT PLACEMENT...AND KSYR WILL BE MOST FAVORED. ALSO...KITH
FOR A TIME LATE AFTERNOON-EARLY EVENING WILL HAVE FAVORABLE WIND
FLOW DOWN CAYUGA LAKE TO GENERATE -SHSN WITH IFR VIS. OTHER
TERMINALS EXCEPT KAVP COULD GET A FLURRY PRETTY MUCH ANYTIME
TODAY...BUT WITH CLOUD LAYER SHALLOW ENOUGH TO PREVENT THE
FLUFFIER DENDRITE FLAKES...AND THUS PROBABLY NOT REDUCING VIS VERY
MUCH.
OUTLOOK...
FRI...MVFR CIG AND PERHAPS LINGERING -SN EARLY ESPECIALLY NY
TERMINALS. CIGS GRADUALLY LIFTING TO VFR.
FRI NGT TO SAT...VFR.
SAT NGT THROUGH MON...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE
NEAR TERM...MSE/PVF
SHORT TERM...MSE
LONG TERM...TAC
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BISMARCK ND
924 PM CST FRI DEC 19 2014
.UPDATE...
ISSUED AT 924 PM CST FRI DEC 19 2014
BASED ON LATEST SATELLITE LOOP...SURFACE OBS AND REPORTS...HAVE
DECIDED TO EXTEND THE DENSE FOG ADVISORY FARTHER TO THE SOUTH AND
EAST. REPORTS AND OBSERVATIONS OF VISIBILITIES DURING THE PAST
HOUR SHOW QUARTER MILE OR LESS VSBYS FROM THE HAZEN AREA EAST
ACROSS NORTHERN BURLEIGH COUNTY AND INTO KIDDER AND STUTSMAN
COUNTIES. FARTHER NORTH AND EAST...VISIBILITIES ARE NOT AS LOW
OVER THE TURTLE MOUNTAINS DOWN INTO FOSTER COUNTY NORTH OF
JAMESTOWN. HOWEVER...LATEST HRRR DOES INDICATE LOWER VISIBILITIES
WORKING THIS WAY LATE TONIGHT INTO SATURDAY MORNING. THERE HAS
BEEN LOW STRATUS AND FOG...ESPECIALLY IN THE TURTLE MOUNTAINS AREA
ALL DAY AND ROADS MAY BE SLIPPERY. ALTHOUGH THERE HAVE BEEN NO
REPORTS AS OF YET...THERE HAS BEEN REPORTS OF FREEZING DRIZZLE
JUST TO THE NORTH IN CANADA AND INTO NORTHEAST NORTH DAKOTA.
UPDATE ISSUED AT 549 PM CST FRI DEC 19 2014
MAIN UPDATE THIS AFTERNOON IS TO EXPAND THE DENSE FOG ADVISORY TO
INCLUDE DIVIDE AND WILLIAMS COUNTIES IN NORTHWEST NORTH
DAKOTA...AND MCLEAN...SHERIDAN AND WELLS COUNTIES IN CENTRAL NORTH
DAKOTA. LATEST SURFACE OBSERVATIONS AND WEATHER CAMERAS INDICATE
THE LOWEST VISIBILITIES ARE ALONG THE PERIPHERY OF THE STRATUS
LAYER FROM DIVIDE AND WILLIAMS COUNTIES SOUTHEAST TO AROUND
GARRISON IN MCLEAN COUNTY AND THEN EAST TOWARD HARVEY IN WELLS
COUNTY. LATEST HRRR MODEL ITERATION SHOWS THE STRATUS EXPANDING
SOUTH AND WEST THIS EVENING...WHICH LOOKS TO VERIFY FROM LAST FEW
SATELLITE IMAGES. OTHERWISE ONLY MINOR UPDATES FOR SKY COVER AND
POPULATED LATEST SENSIBLE WEATHER ELEMENTS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 303 PM CST FRI DEC 19 2014
.SHORT TERM...TONIGHT THROUGH SATURDAY...
PERSISTENT FOG ACROSS THE NORTH WITH CURRENT SATELLITE LOOPS SHOWING
THE STRATUS IS EXPANDING SOUTH INTO THE JAMES NORTHERN JAMES RIVER
VALLEY. NAM BUFKIT SOUNDINGS HAVE A SOLID STRATUS AND FOG LOW LEVEL
SOUNDING FROM WILLISTON THROUGH MINOT WHILE THE GFS MIXES IT OUT
THIS EVENING. WILL LEAN TO THE NAM AND KEEP FOG AND LOW CLOUDS
THOUGH THE NORTH AND EAST CENTRAL TONIGHT. FURTHER ISSUES INVOLVE
VSBYS AS LOW AS ONE QUARTER MILE NEAR TIOGA TO STANLEY. DO NOT
SEE MUCH IMPROVEMENT THERE AND SHOULD SEE LOWER VSBYS IN MINOT
LATER TONIGHT AFTER SUNSET. WILL GO WITH A DENSE FOG ADVISORY FROM
TIOGA TO STANLEY THROUGH 9 PM THEN EXPAND IT EAST THROUGH MINOT
AND TO BOTTINEAU AND MCHENRY COUNTIES THROUGH SATURDAY MORNING.
THE FOG WILL ALSO INSULATE A BIT SO HAVE RAISED TEMPERATURES FOR
OVERNIGHT NIGHT LOWS.
ON SATURDAY...WEAK SHORTWAVE WILL BRING LIGHT AND SPOTTY
PRECIPITATION. EXPECT A WINTRY MIX OF FREEZING RAIN...SOME SLEET AND
SNOW BUT LITTLE ACCUMULATIONS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 303 PM CST FRI DEC 19 2014
FOCUS IN THE LONG TERM IS ON THE LARGE SCALE UPPER LEVEL TROUGH THAT
DEVELOPS OVER THE NORTHERN PLAINS SUNDAY AND DEEPENS SIGNIFICANTLY
OVER THE CENTRAL UNITED STATES INTO EARLY NEXT WEEK.
PAST RUNS OF THE ECMWF AND GFS HAVE CONSISTENTLY SHOWN A DEEPENING
TROUGH OVER THE CENTRAL UNITED STATES SUNDAY INTO EARLY NEXT WEEK.
THE LATEST 12 UTC RUNS OF THE ECMWF AND GFS HAVE BACKED THE SYSTEM
UP A BIT...DEVELOPING A CUT OFF UPPER LEVEL LOW OVER SOUTH DAKOTA
MONDAY WHICH SLOWLY PROPAGATES EAST INTO TUESDAY. THESE SOLUTIONS
BOTH SHOW MORE QPF OVER CENTRAL AND WESTERN NORTH DAKOTA THAN
PREVIOUS MODEL RUNS.
VERTICAL PROFILES ALSO LOOK TO BE BETTER MIXED AFTER THE WEAK
SURFACE COLD FRONT MOVES THROUGH SUNDAY NIGHT. BEFORE THE FRONT
PASSES A LIGHT WINTRY MIX OF FREEZING RAIN...SLEET...RAIN...AND SNOW
WILL BE POSSIBLE ACROSS THE WEST SUNDAY MORNING AND AFTERNOON. ANY
ACCUMULATIONS WILL BE MINOR. STARTING SUNDAY NIGHT THE SOUTHWEST MAY
SEE A BRIEF PERIOD OF RAIN MIXED WITH SNOW...HOWEVER FOR THE REST OF
THE STATE ALL SNOW IS ANTICIPATED. MONDAY AND TUESDAY PRECIPITATION
IS FORECAST AS ALL SNOW AS WELL FOR ALL OF CENTRAL AND WESTERN NORTH
DAKOTA. WITH THAT SAID IF MODEL SOLUTIONS PROGRESS THE TROUGH ALONG
QUICKER SUNDAY NIGHT AND MONDAY...PROFILES ALOFT COULD BE TO DRY FOR
ICE CRYSTALS AND WESTERN AND CENTRAL NORTH DAKOTA COULD ONCE AGAIN
SEE SOME FREEZING RAIN OR DRIZZLE.
EARLY ESTIMATES ON SNOW ACCUMULATIONS FOR MONDAY INTO TUESDAY RANGE
FROM AROUND 2 INCHES WEST TO AN INCH ELSEWHERE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 924 PM CST FRI DEC 19 2014
IFR CEILINGS/VISIBILITIES CONTINUE AT KISN AND KMOT AND HAVE
MOVED INTO JAMESTOWN AND NORTHERN BURLEIGH COUNTY. MESOSCALE
MODELS CONTINUE TO SHOW THE LOW STRATUS/FOG EXPANDING SOUTH AND
WEST TONIGHT TO INCLUDE BISMARCK AND POSSIBLY DICKINSON. HOWEVER
THE WESTERN EXTENT IS NOT AS FAR WEST AS PREVIOUS RUNS SO KDIK
COULD BE SPARED WITH STRATUS/FOG TONIGHT WITH A MORE SOUTHWEST
FLOW. STRATUS WILL LIKELY REMAIN THROUGH THE NIGHT AND INTO
SATURDAY MORNING. THEN DISSIPATE FROM WEST TO EAST LATE SATURDAY
MORNING AND SATURDAY AFTERNOON AS A DRIER SOUTHWEST FLOW TRIES TO
TAKE HOLD ACROSS THE FORECAST AREA.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 6 AM CST SATURDAY FOR NDZ001>005-
009>013-019>023-025-035>037.
&&
$$
UPDATE...TWH
SHORT TERM...WAA
LONG TERM...MM
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
549 PM CST FRI DEC 19 2014
.UPDATE...
ISSUED AT 549 PM CST FRI DEC 19 2014
MAIN UPDATE THIS AFTERNOON IS TO EXPAND THE DENSE FOG ADVISORY TO
INCLUDE DIVIDE AND WILLIAMS COUNTIES IN NORTHWEST NORTH
DAKOTA...AND MCLEAN...SHERIDAN AND WELLS COUNTIES IN CENTRAL NORTH
DAKOTA. LATEST SURFACE OBSERVATIONS AND WEATHER CAMERAS INDICATE
THE LOWEST VISIBILITIES ARE ALONG THE PERIPHERY OF THE STRATUS
LAYER FROM DIVIDE AND WILLIAMS COUNTIES SOUTHEAST TO AROUND
GARRISON IN MCLEAN COUNTY AND THEN EAST TOWARD HARVEY IN WELLS
COUNTY. LATEST HRRR MODEL ITERATION SHOWS THE STRATUS EXPANDING
SOUTH AND WEST THIS EVENING...WHICH LOOKS TO VERIFY FROM LAST FEW
SATELLITE IMAGES. OTHERWISE ONLY MINOR UPDATES FOR SKY COVER AND
POPULATED LATEST SENSIBLE WEATHER ELEMENTS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 303 PM CST FRI DEC 19 2014
.SHORT TERM...TONIGHT THROUGH SATURDAY...
PERSISTENT FOG ACROSS THE NORTH WITH CURRENT SATELLITE LOOPS SHOWING
THE STRATUS IS EXPANDING SOUTH INTO THE JAMES NORTHERN JAMES RIVER
VALLEY. NAM BUFKIT SOUNDINGS HAVE A SOLID STRATUS AND FOG LOW LEVEL
SOUNDING FROM WILLISTON THROUGH MINOT WHILE THE GFS MIXES IT OUT
THIS EVENING. WILL LEAN TO THE NAM AND KEEP FOG AND LOW CLOUDS
THOUGH THE NORTH AND EAST CENTRAL TONIGHT. FURTHER ISSUES INVOLVE
VSBYS AS LOW AS ONE QUARTER MILE NEAR TIOGA TO STANLEY. DO NOT
SEE MUCH IMPROVEMENT THERE AND SHOULD SEE LOWER VSBYS IN MINOT
LATER TONIGHT AFTER SUNSET. WILL GO WITH A DENSE FOG ADVISORY FROM
TIOGA TO STANLEY THROUGH 9 PM THEN EXPAND IT EAST THROUGH MINOT
AND TO BOTTINEAU AND MCHENRY COUNTIES THROUGH SATURDAY MORNING.
THE FOG WILL ALSO INSULATE A BIT SO HAVE RAISED TEMPERATURES FOR
OVERNIGHT NIGHT LOWS.
ON SATURDAY...WEAK SHORTWAVE WILL BRING LIGHT AND SPOTTY
PRECIPITATION. EXPECT A WINTRY MIX OF FREEZING RAIN...SOME SLEET AND
SNOW BUT LITTLE ACCUMULATIONS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 303 PM CST FRI DEC 19 2014
FOCUS IN THE LONG TERM IS ON THE LARGE SCALE UPPER LEVEL TROUGH THAT
DEVELOPS OVER THE NORTHERN PLAINS SUNDAY AND DEEPENS SIGNIFICANTLY
OVER THE CENTRAL UNITED STATES INTO EARLY NEXT WEEK.
PAST RUNS OF THE ECMWF AND GFS HAVE CONSISTENTLY SHOWN A DEEPENING
TROUGH OVER THE CENTRAL UNITED STATES SUNDAY INTO EARLY NEXT WEEK.
THE LATEST 12 UTC RUNS OF THE ECMWF AND GFS HAVE BACKED THE SYSTEM
UP A BIT...DEVELOPING A CUT OFF UPPER LEVEL LOW OVER SOUTH DAKOTA
MONDAY WHICH SLOWLY PROPAGATES EAST INTO TUESDAY. THESE SOLUTIONS
BOTH SHOW MORE QPF OVER CENTRAL AND WESTERN NORTH DAKOTA THAN
PREVIOUS MODEL RUNS.
VERTICAL PROFILES ALSO LOOK TO BE BETTER MIXED AFTER THE WEAK
SURFACE COLD FRONT MOVES THROUGH SUNDAY NIGHT. BEFORE THE FRONT
PASSES A LIGHT WINTRY MIX OF FREEZING RAIN...SLEET...RAIN...AND SNOW
WILL BE POSSIBLE ACROSS THE WEST SUNDAY MORNING AND AFTERNOON. ANY
ACCUMULATIONS WILL BE MINOR. STARTING SUNDAY NIGHT THE SOUTHWEST MAY
SEE A BRIEF PERIOD OF RAIN MIXED WITH SNOW...HOWEVER FOR THE REST OF
THE STATE ALL SNOW IS ANTICIPATED. MONDAY AND TUESDAY PRECIPITATION
IS FORECAST AS ALL SNOW AS WELL FOR ALL OF CENTRAL AND WESTERN NORTH
DAKOTA. WITH THAT SAID IF MODEL SOLUTIONS PROGRESS THE TROUGH ALONG
QUICKER SUNDAY NIGHT AND MONDAY...PROFILES ALOFT COULD BE TO DRY FOR
ICE CRYSTALS AND WESTERN AND CENTRAL NORTH DAKOTA COULD ONCE AGAIN
SEE SOME FREEZING RAIN OR DRIZZLE.
EARLY ESTIMATES ON SNOW ACCUMULATIONS FOR MONDAY INTO TUESDAY RANGE
FROM AROUND 2 INCHES WEST TO AN INCH ELSEWHERE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 549 PM CST FRI DEC 19 2014
IFR CEILINGS AT KISN AND KMOT TO BEGIN THE TAF PERIOD IN
PERSISTENT LOW STRATUS. MESOSCALE MODELS SHOW THE STRATUS LAYER
EXPANDING SOUTH AND WEST TONIGHT TO LIKELY INCLUDE BISMARCK AND
JAMESTOWN BETWEEN 00 AND 03 UTC...AND POSSIBLY KDIK AROUND 06 UTC.
STRATUS WILL LIKELY REMAIN THROUGH THE NIGHT AND INTO SATURDAY
MORNING. THEN DISSIPATE FROM WEST TO EAST LATE SATURDAY MORNING
AND SATURDAY AFTERNOON AS A DRIER SOUTHWEST FLOW TRIES TO TAKE
HOLD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 6 AM CST SATURDAY FOR NDZ001-002-009-
010-021>023.
DENSE FOG ADVISORY FROM 9 PM THIS EVENING TO 6 AM CST SATURDAY
FOR NDZ003-004-011-012.
&&
$$
UPDATE...TWH
SHORT TERM...WAA
LONG TERM...MM
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1132 AM CST THU DEC 18 2014
.UPDATE...
ISSUED AT 959 AM CST THU DEC 18 2014
CLOUD TRENDS THE MAIN ISSUE TODAY. AREA OF MID CLOUDS AND THEN
LOWER MVFR CLOUDS ADVANCING NORTHEAST EAST OF THE UPPER TROUGH
OVER WRN ND. THIS WILL CONTINUE TO SPREAD EAST INTO THIS AFTN.
ALSO GOT A FAST MOVING AREA OF LOWER STRATOCU MOVING NORTH-
NORTHWEST FROM WISCONSIN INTO NE-ECNTRL MN AND ITS HEADED TOWARD
OUR EASTERN COUNTIES SO INCREASED CLOUD COVER THERE. ALSO QUITE A
BIT OF FLURRIES IN THIS CLOUD AREA...SO MATCHED UP WITH WFO DLH
AND INCLUDED FLURRIES THIS AFTN IN THE FAR EASTERN FCST AREA. KEPT
FLURRIES IN FAR WEST BUT HAVENT SEEN ANY SIGNS OF PRECIP IN CNTRL
ND.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 314 AM CST THU DEC 18 2014
MAIN ISSUE TODAY WILL BE CLOUDS MOVING INTO THE WEST AND IF WE GET
ANY SNOW OF MENTION OR JUST FLURRIES.
A WEAK UPPER SHORTWAVE TROUGH IS SEEN ON WV LOOP ROTATING OVER THE
MT/ND BORDER...AND THAT FEATURE WILL MOVE INTO THE EASTERN DAKOTAS
TODAY. THIS WILL HELP BRING SOME FAIRLY WEAK SYNOPTIC LIFT INTO THE
REGION. THE SFC HIGH WILL MOVE OFF TO THE EAST...ALLOWING SOUTH
WINDS AND MORE MOISTURE TO MOVE BACK INTO THE AREA. THERE HAS BEEN
A DECENT BAND OF SNOW OVER CENTRAL ND...WHICH MATCHES PRETTY WELL
WHERE THE RAP HAS SOME Q VECTOR CONVERGENCE COINCIDING WITH
FRONTOGENESIS. THE RAP HAS THIS FEATURE WEAKENING SIGNIFICANTLY AS
IT MOVES EAST INTO OUR CWA LATER THIS MORNING...SO THINK A WELL
DEFINED BAND OF SNOW IS NOT TOO LIKELY. HOWEVER...SOME VERY LIGHT
SNOW IS NOT OUT OF THE QUESTION. INCLUDED SOME LOW POPS IN THE FAR
WEST WITH SOME FLURRIES GRADUALLY MOVING TOWARDS THE RED RIVER AS
CLOUDS CONTINUE TO INCREASE THROUGHOUT THE DAY IN THE WESTERN
COUNTIES. TEMPS TODAY SHOULD BE A BIT WARMER EVEN WITH CLOUDS AS
TEMPS UNDER THE CLOUDS ARE ALREADY CLOSE TO 20 DEGREES OUT WEST.
WILL CONTINUE TO KEEP HIGHS IN THE UPPER TEENS TO 20S.
TONIGHT...THE WEAK UPPER TROUGH CONTINUES OVER THE NORTHERN
PLAINS...WITH WARM AIR ADVECTION CONTINUING THROUGHOUT THE NIGHT.
CLOUDS WILL CONTINUE TO MOVE INTO THE AREA AND THAT ALONG WITH THE
SOUTH WINDS WILL PREVENT TEMPS FROM BOTTOMING OUT TONIGHT. TEMPS
SHOULD STAY MAINLY IN THE TEENS. THE WARM AIR ADVECTION WILL
CONTINUE INTO FRIDAY...ALLOWING TEMPS TO GET WELL INTO THE 20S TO
NEAR 30 IN THE SOUTH. MODELS CONTINUE TO SHOW SOME VERY LIGHT
PRECIP AS ISENTROPIC LIFT CONTINUES AND CONDENSATION PRESSURE
DEFICITS BECOME MORE FAVORABLE...MAINLY IN THE NORTHEASTERN
COUNTIES. WILL CONTINUE TO KEEP 20 POPS GOING FOR LIGHT SNOW...BUT
THINK THAT ANY ACCUMULATION WILL BE VERY LIGHT.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 314 AM CST THU DEC 18 2014
FRIDAY NIGHT THROUGH SATURDAY NIGHT...THE WEAK UPPER TROUGH
LINGERS OVER NORTHERN MN...AND THE NEXT SHORTWAVE TROUGH BEGINS TO
APPROACH FROM THE WEST. SOUTH WINDS WILL CONTINUE AND MOISTURE
SHOULD BE INCREASING. THERE CONTINUE TO BE SOME SIGNS OF PRECIP
MOVING IN WITH THAT SECOND SHORTWAVE LATE SATURDAY INTO SATURDAY
NIGHT. THERE IS A LOT OF VARIATION FROM THE NAM SHOWING UP TO A
TENTH OF AN INCH TO THE ECMWF HAVING HARDLY ANYTHING...SO KEPT
POPS LOW FOR NOW. THE SREF SHOWS SOME FZRA PROBABILITIES FOR
SATURDAY NIGHT...BUT THE TOP DOWN METHOD GIVES MOSTLY SNOW IN THE
NORTH WHERE POPS ARE LOCATED WITH THE WARM LAYER ALOFT STAYING
MOSTLY IN OUR SOUTH WHERE CURRENTLY WE ARE GOING DRY. WILL KEEP A
CLOSE EYE ON THE SITUATION. TEMPS WILL BE ABOVE AVERAGE WITH HIGHS
PUSHING 30 DEGREES AND LOWS STAYING IN THE TEENS TO EVEN LOW 20S.
FOR SUNDAY THROUGH WEDNESDAY...UPPER PATTERN SHIFTS A BIT BECOMING
MORE OF A NW FLOW REGIME WITH THE RIDGE AXIS OVER THE INTERMOUNTAIN
WEST. HOWEVER...THE MAIN JET ENERGY IS EXPECTED TO REMAIN WEST AND
SOUTH OF THE AREA. A FEW WAVES PUSHING ACROSS THE AREA WILL BRING
CHANCES FOR LIGHT PCPN...WHILE TEMPERATURES CONTINUE TO REMAIN NEAR
OR SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1112 AM CST THU DEC 18 2014
AS HIGH PRESSURE DRIFTS EAST...THE AREA WILL SEE LIGHT S TO SE
WINDS CONTINUE THROUGH THE NEXT 24 HRS. BASED ON THE LATEST
TRENDS AND MODEL DATA...LOWER MVFR TO IFR CIGS WILL BE INCREASING
OVER MUCH OF THE AREA OVER THE NEXT 6-12 HRS. THE NAM MOS DATA
SUPPORT CIGS BELOW 1000 FT...WITH NAM BUFR SOUNDINGS SATURATED IN
THE LOW LEVES AS WELL. SOME CIGS MAY DIP BELOW 500 FT BY LATE
TOMORROW MORNING ACCORDING TO THE NAM MOS. HAVE NOT INCLUDED CIGS
THIS LOW YET...BUT WILL NEED TO MONITOR TRENDS AND MODEL DATA TO
SEE IF THE LIKELIHOOD INCREASES.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...KNUTSVIG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1001 AM CST THU DEC 18 2014
.UPDATE...
ISSUED AT 959 AM CST THU DEC 18 2014
CLOUD TRENDS THE MAIN ISSUE TODAY. AREA OF MID CLOUDS AND THEN
LOWER MVFR CLOUDS ADVANCING NORTHEAST EAST OF THE UPPER TROUGH
OVER WRN ND. THIS WILL CONTINUE TO SPREAD EAST INTO THIS AFTN.
ALSO GOT A FAST MOVING AREA OF LOWER STRATOCU MOVING NORTH-
NORTHWEST FROM WISCONSIN INTO NE-ECNTRL MN AND ITS HEADED TOWARD
OUR EASTERN COUNTIES SO INCREASED CLOUD COVER THERE. ALSO QUITE A
BIT OF FLURRIES IN THIS CLOUD AREA...SO MATCHED UP WITH WFO DLH
AND INCLUDED FLURRIES THIS AFTN IN THE FAR EASTERN FCST AREA. KEPT
FLURRIES IN FAR WEST BUT HAVENT SEEN ANY SIGNS OF PRECIP IN CNTRL
ND.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 314 AM CST THU DEC 18 2014
MAIN ISSUE TODAY WILL BE CLOUDS MOVING INTO THE WEST AND IF WE GET
ANY SNOW OF MENTION OR JUST FLURRIES.
A WEAK UPPER SHORTWAVE TROUGH IS SEEN ON WV LOOP ROTATING OVER THE
MT/ND BORDER...AND THAT FEATURE WILL MOVE INTO THE EASTERN DAKOTAS
TODAY. THIS WILL HELP BRING SOME FAIRLY WEAK SYNOPTIC LIFT INTO THE
REGION. THE SFC HIGH WILL MOVE OFF TO THE EAST...ALLOWING SOUTH
WINDS AND MORE MOISTURE TO MOVE BACK INTO THE AREA. THERE HAS BEEN
A DECENT BAND OF SNOW OVER CENTRAL ND...WHICH MATCHES PRETTY WELL
WHERE THE RAP HAS SOME Q VECTOR CONVERGENCE COINCIDING WITH
FRONTOGENESIS. THE RAP HAS THIS FEATURE WEAKENING SIGNIFICANTLY AS
IT MOVES EAST INTO OUR CWA LATER THIS MORNING...SO THINK A WELL
DEFINED BAND OF SNOW IS NOT TOO LIKELY. HOWEVER...SOME VERY LIGHT
SNOW IS NOT OUT OF THE QUESTION. INCLUDED SOME LOW POPS IN THE FAR
WEST WITH SOME FLURRIES GRADUALLY MOVING TOWARDS THE RED RIVER AS
CLOUDS CONTINUE TO INCREASE THROUGHOUT THE DAY IN THE WESTERN
COUNTIES. TEMPS TODAY SHOULD BE A BIT WARMER EVEN WITH CLOUDS AS
TEMPS UNDER THE CLOUDS ARE ALREADY CLOSE TO 20 DEGREES OUT WEST.
WILL CONTINUE TO KEEP HIGHS IN THE UPPER TEENS TO 20S.
TONIGHT...THE WEAK UPPER TROUGH CONTINUES OVER THE NORTHERN
PLAINS...WITH WARM AIR ADVECTION CONTINUING THROUGHOUT THE NIGHT.
CLOUDS WILL CONTINUE TO MOVE INTO THE AREA AND THAT ALONG WITH THE
SOUTH WINDS WILL PREVENT TEMPS FROM BOTTOMING OUT TONIGHT. TEMPS
SHOULD STAY MAINLY IN THE TEENS. THE WARM AIR ADVECTION WILL
CONTINUE INTO FRIDAY...ALLOWING TEMPS TO GET WELL INTO THE 20S TO
NEAR 30 IN THE SOUTH. MODELS CONTINUE TO SHOW SOME VERY LIGHT
PRECIP AS ISENTROPIC LIFT CONTINUES AND CONDENSATION PRESSURE
DEFICITS BECOME MORE FAVORABLE...MAINLY IN THE NORTHEASTERN
COUNTIES. WILL CONTINUE TO KEEP 20 POPS GOING FOR LIGHT SNOW...BUT
THINK THAT ANY ACCUMULATION WILL BE VERY LIGHT.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 314 AM CST THU DEC 18 2014
FRIDAY NIGHT THROUGH SATURDAY NIGHT...THE WEAK UPPER TROUGH
LINGERS OVER NORTHERN MN...AND THE NEXT SHORTWAVE TROUGH BEGINS TO
APPROACH FROM THE WEST. SOUTH WINDS WILL CONTINUE AND MOISTURE
SHOULD BE INCREASING. THERE CONTINUE TO BE SOME SIGNS OF PRECIP
MOVING IN WITH THAT SECOND SHORTWAVE LATE SATURDAY INTO SATURDAY
NIGHT. THERE IS A LOT OF VARIATION FROM THE NAM SHOWING UP TO A
TENTH OF AN INCH TO THE ECMWF HAVING HARDLY ANYTHING...SO KEPT
POPS LOW FOR NOW. THE SREF SHOWS SOME FZRA PROBABILITIES FOR
SATURDAY NIGHT...BUT THE TOP DOWN METHOD GIVES MOSTLY SNOW IN THE
NORTH WHERE POPS ARE LOCATED WITH THE WARM LAYER ALOFT STAYING
MOSTLY IN OUR SOUTH WHERE CURRENTLY WE ARE GOING DRY. WILL KEEP A
CLOSE EYE ON THE SITUATION. TEMPS WILL BE ABOVE AVERAGE WITH HIGHS
PUSHING 30 DEGREES AND LOWS STAYING IN THE TEENS TO EVEN LOW 20S.
FOR SUNDAY THROUGH WEDNESDAY...UPPER PATTERN SHIFTS A BIT BECOMING
MORE OF A NW FLOW REGIME WITH THE RIDGE AXIS OVER THE INTERMOUNTAIN
WEST. HOWEVER...THE MAIN JET ENERGY IS EXPECTED TO REMAIN WEST AND
SOUTH OF THE AREA. A FEW WAVES PUSHING ACROSS THE AREA WILL BRING
CHANCES FOR LIGHT PCPN...WHILE TEMPERATURES CONTINUE TO REMAIN NEAR
OR SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 658 AM CST THU DEC 18 2014
ALL SITES ARE VFR FOR THE TIME BEING BUT CLOUDS ARE MAKING A RUN
FOR THE FORECAST AREA BOTH FROM THE WEST AND FROM THE EAST. CLOUDS
ENTERING THE KDVL AREA ARE MID LEVEL...SO VFR WILL REMAIN FOR A
BIT LONGER. THINK THAT THERE WILL BE SOME INCREASING MID CLOUDS
THROUGHOUT THE DAY AND THEN SOME MVFR CIGS MOVING IN LATE THIS
AFTERNOON AND EVENING. THE MODELS ARE NOT HANDLING THE STRATUS
MOVING NORTHWESTWARD THROUGH EASTERN MN...WHICH MAY IMPACT KBJI
LATER ON. BASED ON THE SPEED OF THE CLOUD DECK SOME MVFR CIGS
COULD ENTER KBJI AS SOON AS EARLY AFTERNOON. ALL TAF SITES SHOULD
BE MVFR OR EVEN IFR BY THE END OF THE PERIOD. SOME FLURRIES ARE
POSSIBLE BUT NOT WIDESPREAD OR EXPECTED TO BRING VIS DOWN FOR AN
EXTENDED PERIOD. LIGHT AND VARIABLE WINDS WILL STEADY OUT OF THE
SOUTHEAST AT UNDER 10 KTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
658 AM CST THU DEC 18 2014
.UPDATE...
ISSUED AT 658 AM CST THU DEC 18 2014
ADJUSTED CLOUDS A BIT AS THERE SEEMS TO BE A BIT FASTER CLOUDING
UP OF THE WESTERN CWA. A BAND OF RADAR RETURNS HAS ENTERED THE
WESTERN CWA BUT NOT MUCH AT THIS POINT HAS BEEN SEEN REACHING THE
GROUND. INCLUDED JUST A FLURRY MENTION BUT THINK THAT ACCUMULATING
SNOW CHANCES WILL BE MINIMAL.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 314 AM CST THU DEC 18 2014
MAIN ISSUE TODAY WILL BE CLOUDS MOVING INTO THE WEST AND IF WE GET
ANY SNOW OF MENTION OR JUST FLURRIES.
A WEAK UPPER SHORTWAVE TROUGH IS SEEN ON WV LOOP ROTATING OVER THE
MT/ND BORDER...AND THAT FEATURE WILL MOVE INTO THE EASTERN DAKOTAS
TODAY. THIS WILL HELP BRING SOME FAIRLY WEAK SYNOPTIC LIFT INTO THE
REGION. THE SFC HIGH WILL MOVE OFF TO THE EAST...ALLOWING SOUTH
WINDS AND MORE MOISTURE TO MOVE BACK INTO THE AREA. THERE HAS BEEN
A DECENT BAND OF SNOW OVER CENTRAL ND...WHICH MATCHES PRETTY WELL
WHERE THE RAP HAS SOME Q VECTOR CONVERGENCE COINCIDING WITH
FRONTOGENESIS. THE RAP HAS THIS FEATURE WEAKENING SIGNIFICANTLY AS
IT MOVES EAST INTO OUR CWA LATER THIS MORNING...SO THINK A WELL
DEFINED BAND OF SNOW IS NOT TOO LIKELY. HOWEVER...SOME VERY LIGHT
SNOW IS NOT OUT OF THE QUESTION. INCLUDED SOME LOW POPS IN THE FAR
WEST WITH SOME FLURRIES GRADUALLY MOVING TOWARDS THE RED RIVER AS
CLOUDS CONTINUE TO INCREASE THROUGHOUT THE DAY IN THE WESTERN
COUNTIES. TEMPS TODAY SHOULD BE A BIT WARMER EVEN WITH CLOUDS AS
TEMPS UNDER THE CLOUDS ARE ALREADY CLOSE TO 20 DEGREES OUT WEST.
WILL CONTINUE TO KEEP HIGHS IN THE UPPER TEENS TO 20S.
TONIGHT...THE WEAK UPPER TROUGH CONTINUES OVER THE NORTHERN
PLAINS...WITH WARM AIR ADVECTION CONTINUING THROUGHOUT THE NIGHT.
CLOUDS WILL CONTINUE TO MOVE INTO THE AREA AND THAT ALONG WITH THE
SOUTH WINDS WILL PREVENT TEMPS FROM BOTTOMING OUT TONIGHT. TEMPS
SHOULD STAY MAINLY IN THE TEENS. THE WARM AIR ADVECTION WILL
CONTINUE INTO FRIDAY...ALLOWING TEMPS TO GET WELL INTO THE 20S TO
NEAR 30 IN THE SOUTH. MODELS CONTINUE TO SHOW SOME VERY LIGHT
PRECIP AS ISENTROPIC LIFT CONTINUES AND CONDENSATION PRESSURE
DEFICITS BECOME MORE FAVORABLE...MAINLY IN THE NORTHEASTERN
COUNTIES. WILL CONTINUE TO KEEP 20 POPS GOING FOR LIGHT SNOW...BUT
THINK THAT ANY ACCUMULATION WILL BE VERY LIGHT.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 314 AM CST THU DEC 18 2014
FRIDAY NIGHT THROUGH SATURDAY NIGHT...THE WEAK UPPER TROUGH
LINGERS OVER NORTHERN MN...AND THE NEXT SHORTWAVE TROUGH BEGINS TO
APPROACH FROM THE WEST. SOUTH WINDS WILL CONTINUE AND MOISTURE
SHOULD BE INCREASING. THERE CONTINUE TO BE SOME SIGNS OF PRECIP
MOVING IN WITH THAT SECOND SHORTWAVE LATE SATURDAY INTO SATURDAY
NIGHT. THERE IS A LOT OF VARIATION FROM THE NAM SHOWING UP TO A
TENTH OF AN INCH TO THE ECMWF HAVING HARDLY ANYTHING...SO KEPT
POPS LOW FOR NOW. THE SREF SHOWS SOME FZRA PROBABILITIES FOR
SATURDAY NIGHT...BUT THE TOP DOWN METHOD GIVES MOSTLY SNOW IN THE
NORTH WHERE POPS ARE LOCATED WITH THE WARM LAYER ALOFT STAYING
MOSTLY IN OUR SOUTH WHERE CURRENTLY WE ARE GOING DRY. WILL KEEP A
CLOSE EYE ON THE SITUATION. TEMPS WILL BE ABOVE AVERAGE WITH HIGHS
PUSHING 30 DEGREES AND LOWS STAYING IN THE TEENS TO EVEN LOW 20S.
FOR SUNDAY THROUGH WEDNESDAY...UPPER PATTERN SHIFTS A BIT BECOMING
MORE OF A NW FLOW REGIME WITH THE RIDGE AXIS OVER THE INTERMOUNTAIN
WEST. HOWEVER...THE MAIN JET ENERGY IS EXPECTED TO REMAIN WEST AND
SOUTH OF THE AREA. A FEW WAVES PUSHING ACROSS THE AREA WILL BRING
CHANCES FOR LIGHT PCPN...WHILE TEMPERATURES CONTINUE TO REMAIN NEAR
OR SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 658 AM CST THU DEC 18 2014
ALL SITES ARE VFR FOR THE TIME BEING BUT CLOUDS ARE MAKING A RUN
FOR THE FORECAST AREA BOTH FROM THE WEST AND FROM THE EAST. CLOUDS
ENTERING THE KDVL AREA ARE MID LEVEL...SO VFR WILL REMAIN FOR A
BIT LONGER. THINK THAT THERE WILL BE SOME INCREASING MID CLOUDS
THROUGHOUT THE DAY AND THEN SOME MVFR CIGS MOVING IN LATE THIS
AFTERNOON AND EVENING. THE MODELS ARE NOT HANDLING THE STRATUS
MOVING NORTHWESTWARD THROUGH EASTERN MN...WHICH MAY IMPACT KBJI
LATER ON. BASED ON THE SPEED OF THE CLOUD DECK SOME MVFR CIGS
COULD ENTER KBJI AS SOON AS EARLY AFTERNOON. ALL TAF SITES SHOULD
BE MVFR OR EVEN IFR BY THE END OF THE PERIOD. SOME FLURRIES ARE
POSSIBLE BUT NOT WIDESPREAD OR EXPECTED TO BRING VIS DOWN FOR AN
EXTENDED PERIOD. LIGHT AND VARIABLE WINDS WILL STEADY OUT OF THE
SOUTHEAST AT UNDER 10 KTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
314 AM CST THU DEC 18 2014
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 314 AM CST THU DEC 18 2014
MAIN ISSUE TODAY WILL BE CLOUDS MOVING INTO THE WEST AND IF WE GET
ANY SNOW OF MENTION OR JUST FLURRIES.
A WEAK UPPER SHORTWAVE TROUGH IS SEEN ON WV LOOP ROTATING OVER THE
MT/ND BORDER...AND THAT FEATURE WILL MOVE INTO THE EASTERN DAKOTAS
TODAY. THIS WILL HELP BRING SOME FAIRLY WEAK SYNOPTIC LIFT INTO THE
REGION. THE SFC HIGH WILL MOVE OFF TO THE EAST...ALLOWING SOUTH
WINDS AND MORE MOISTURE TO MOVE BACK INTO THE AREA. THERE HAS BEEN
A DECENT BAND OF SNOW OVER CENTRAL ND...WHICH MATCHES PRETTY WELL
WHERE THE RAP HAS SOME Q VECTOR CONVERGENCE COINCIDING WITH
FRONTOGENESIS. THE RAP HAS THIS FEATURE WEAKENING SIGNIFICANTLY AS
IT MOVES EAST INTO OUR CWA LATER THIS MORNING...SO THINK A WELL
DEFINED BAND OF SNOW IS NOT TOO LIKELY. HOWEVER...SOME VERY LIGHT
SNOW IS NOT OUT OF THE QUESTION. INCLUDED SOME LOW POPS IN THE FAR
WEST WITH SOME FLURRIES GRADUALLY MOVING TOWARDS THE RED RIVER AS
CLOUDS CONTINUE TO INCREASE THROUGHOUT THE DAY IN THE WESTERN
COUNTIES. TEMPS TODAY SHOULD BE A BIT WARMER EVEN WITH CLOUDS AS
TEMPS UNDER THE CLOUDS ARE ALREADY CLOSE TO 20 DEGREES OUT WEST.
WILL CONTINUE TO KEEP HIGHS IN THE UPPER TEENS TO 20S.
TONIGHT...THE WEAK UPPER TROUGH CONTINUES OVER THE NORTHERN
PLAINS...WITH WARM AIR ADVECTION CONTINUING THROUGHOUT THE NIGHT.
CLOUDS WILL CONTINUE TO MOVE INTO THE AREA AND THAT ALONG WITH THE
SOUTH WINDS WILL PREVENT TEMPS FROM BOTTOMING OUT TONIGHT. TEMPS
SHOULD STAY MAINLY IN THE TEENS. THE WARM AIR ADVECTION WILL
CONTINUE INTO FRIDAY...ALLOWING TEMPS TO GET WELL INTO THE 20S TO
NEAR 30 IN THE SOUTH. MODELS CONTINUE TO SHOW SOME VERY LIGHT
PRECIP AS ISENTROPIC LIFT CONTINUES AND CONDENSATION PRESSURE
DEFICITS BECOME MORE FAVORABLE...MAINLY IN THE NORTHEASTERN
COUNTIES. WILL CONTINUE TO KEEP 20 POPS GOING FOR LIGHT SNOW...BUT
THINK THAT ANY ACCUMULATION WILL BE VERY LIGHT.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 314 AM CST THU DEC 18 2014
FRIDAY NIGHT THROUGH SATURDAY NIGHT...THE WEAK UPPER TROUGH
LINGERS OVER NORTHERN MN...AND THE NEXT SHORTWAVE TROUGH BEGINS TO
APPROACH FROM THE WEST. SOUTH WINDS WILL CONTINUE AND MOISTURE
SHOULD BE INCREASING. THERE CONTINUE TO BE SOME SIGNS OF PRECIP
MOVING IN WITH THAT SECOND SHORTWAVE LATE SATURDAY INTO SATURDAY
NIGHT. THERE IS A LOT OF VARIATION FROM THE NAM SHOWING UP TO A
TENTH OF AN INCH TO THE ECMWF HAVING HARDLY ANYTHING...SO KEPT
POPS LOW FOR NOW. THE SREF SHOWS SOME FZRA PROBABILITIES FOR
SATURDAY NIGHT...BUT THE TOP DOWN METHOD GIVES MOSTLY SNOW IN THE
NORTH WHERE POPS ARE LOCATED WITH THE WARM LAYER ALOFT STAYING
MOSTLY IN OUR SOUTH WHERE CURRENTLY WE ARE GOING DRY. WILL KEEP A
CLOSE EYE ON THE SITUATION. TEMPS WILL BE ABOVE AVERAGE WITH HIGHS
PUSHING 30 DEGREES AND LOWS STAYING IN THE TEENS TO EVEN LOW 20S.
FOR SUNDAY THROUGH WEDNESDAY...UPPER PATTERN SHIFTS A BIT BECOMING
MORE OF A NW FLOW REGIME WITH THE RIDGE AXIS OVER THE INTERMOUNTAIN
WEST. HOWEVER...THE MAIN JET ENERGY IS EXPECTED TO REMAIN WEST AND
SOUTH OF THE AREA. A FEW WAVES PUSHING ACROSS THE AREA WILL BRING
CHANCES FOR LIGHT PCPN...WHILE TEMPERATURES CONTINUE TO REMAIN NEAR
OR SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1130 PM CST WED DEC 17 2014
CLOUDS WILL CONTINUE APPROACHING THE REGION FROM THE WEST...BUT
WILL TAKE THEIR TIME GETTING HERE. THE MVFR CIGS WILL LIKELY MOVE
INTO KDVL BY MID-LATE AFTERNOON...VALLEY SITES CLOSER TO MIDNIGHT.
LIGHT WINDS WILL GRADUALLY BECOME SOUTHERLY...BUT REMAIN AOB 10
KNOTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...TG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
216 AM CST THU DEC 18 2014
.UPDATE...
ISSUED AT 215 AM CST THU DEC 18 2014
QUICK UPDATE AS A NARROW BAND OF MODERATE TO HEAVY SNOW PER LATEST
RADAR...AND CONFIRMATION FROM LOCAL LAW ENFORCEMENT ACROSS WEST
CENTRAL NORTH DAKOTA. THE GFS 1.5 PVU 850-700MB AXIS ATOP AN AREA
OF 850MB FRONTOGENESIS IS RESULTING IN A NARROW BAND OF HEAVY
SNOWFALL. TIGHT CIRCULATION CAN BE SEEN ON THE 0.5 DEGREE RADAR
SLICE. THE BAND OF SNOW BEGINS FROM HIGHWAY 8...JUST WEST OF
HALLIDAY WHERE LAW ENFORCEMENT REPORTED VISIBILITY OF AROUND
FIFTEEN 15 FEET WITH ABOUT A HALF INCH OF SNOW. WEBCAMS AT
COLEHARBOR AND WHITE SHIELD CONFIRM BRIEF BUT INTENSE SNOW. HAVE
UPDATED THE GRIDDED FORECAST AND FOLLOWED THIS AXIS THROUGH THE
MORNING AS IT SLIDES NORTH. THE BAND EXTENDS SOUTHEAST INTO
GARRISON...WILTON...REGAN AND WING. A NOWCAST WAS SENT EARLIER
REFLECT CURRENT CONDITIONS. UPDATES TO THE TEXT PRODUCTS
FORTHCOMING.
UPDATE ISSUED AT 1212 AM CST THU DEC 18 2014
LATEST WATER VAPOR IMAGERY LOOP PLACES AN UPPER LOW CIRCULATING JUST
SOUTH OF WILLISTON WITH A SHORTWAVE MOVING INTO THE BASE OF THE
TROUGH...LOCATED ACROSS SOUTHEAST MONTANA. THIS SHORTWAVE IS
FORECAST TO PROPAGATE SLOWLY EAST OVERNIGHT/THURSDAY...BEING LOCATED
BETWEEN DICKINSON AND BISMARCK BY 12Z...AND BETWEEN BISMARCK AND
JAMESTOWN BY 18Z THURSDAY. THE LATEST RAP13 BUFKIT SOUNDINGS FOR
KDIK/KBIS/KJMS INDICATE ENOUGH OMEGA/LIFT IN THE LOW LEVEL SATURATED
LAYER WITH RESPECT TO ICE. AS THE FROST POINT EXCEEDS THE
TEMPERATURE...SNOW PRODUCTION WILL RESULT IN THE SUPERSATURATED
ENVIRONMENT FOR A MENTION OF ISOLATED TO SCATTERED SNOW
SHOWERS/MEASURABLE AMOUNTS OVERNIGHT INTO THURSDAY AFTERNOON AS IT
SLOWLY MOVES EAST. HAVE UPDATED THE GRIDS FOR THIS FEATURE AND WILL
MONITOR AS IT EVOLVES THROUGH THE EARLY MORNING. THINKING IS ONE TO
TWO TENTHS OF AN INCH OF SNOW POSSIBLE ACROSS PORTIONS SOUTHERN
NORTH DAKOTA. SCATTERED FLURRIES STILL A GOOD BET WITH THE ACTUAL
UPPER LOW IN THE NORTHWEST AND NORTH CENTRAL OVERNIGHT AND WILL
CONTINUE WITH THIS IDEA.
UPDATE ISSUED AT 949 PM CST WED DEC 17 2014
MAIN ISSUE LATE THIS EVENING WILL BE LIGHT SNOW/FLURRY CHANCES.
TEMPERATURES WILL BE A HASSLE AGAIN ALONG THE BORDER BETWEEN THE
LOW CLOUDS AND CLEAR SKIES OVER CENTRAL ND...BUT TREND SEEMS
REASONABLE SO NO BIG CHANGES HERE.
LATEST 00 UTC NAM AND 02 UTC RAP SHOW A COUPLE SHORTWAVE IMPULSES
ROTATING AROUND AN UPPER LOW OVER EASTERN MONTANA. THE LEAD WAVE
IS AIDING IN THE DEVELOPMENT OF A SMALL BAND OF SNOW SHOWERS
LIFTING NORTHWARD THROUGH SOUTHWEST INTO CENTRAL NORTH DAKOTA.
GROUND REPORTS ARE INDICATING A BRIEF PERIOD OF SNOW SHOWERS WITH
NO SIGNIFICANT ACCUMULATIONS. WITH THE SMALL BAND LIFTING QUICKLY
NORTH...OPTED TO KEEP THIS AS A CONTINUED MENTION OF FLURRIES AS
GETTING A HUNDREDTH OF AN INCH IS NOT LIKELY.
LATER TONIGHT AND INTO THURSDAY MORNING A STRONGER SHORTWAVE MOVES
WEST ALONG THE NORTH DAKOTA/SOUTH DAKOTA BORDER. ALTHOUGH RAP/NAM
QPF IS CURRENTLY NIL...THE RAP/HRRR ARE SHOWING SOME LIGHT RADAR
REFLECTIVITIES DEVELOPING OVER SOUTHWEST NORTH DAKOTA IN THE 07-12
UTC TIMEFRAME. THINKING AS WE GO THROUGH A FEW MORE ITERATIONS OF
THE RAP/HRRR...THIS MAY CONTINUE TO PROGRESS INTO THE SOUTH
CENTRAL DURING THE MORNING HOURS...AND POSSIBLY INCREASE GIVEN THE
STRENGTH OF THE SHORTWAVE. WITH A MOIST BOUNDARY LAYER AND
INCREASING SEEDER-FEEDER MECHANISM WITH INCREASING MID LEVEL
CLOUDS...HAVE EXTENDED FLURRIES THROUGH THURSDAY MORNING ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. THINK MID SHIFT WILL HAVE THE
TIME TO RE-EVALUATE AND ADD A MENTION OF LIGHT SNOW FOR THE
MORNING HOURS IF NEEDED. ACCUMULATIONS WILL REMAIN LIGHT BUT THIS
SECOND WAVE LOOKS STRONG ENOUGH TO GIVE SOME OF US A LITTLE MORE
THAN JUST FLURRIES.
UPDATE ISSUED AT 551 PM CST WED DEC 17 2014
LOW STRATUS REMAINS ACROSS MUCH OF WESTERN AND CENTRAL NORTH
DAKOTA...AND WILL ONCE AGAIN BE A CONCERN FOR OVERNIGHT LOW
TEMPERATURES. DO EXPECT THE STRATUS TO BEGIN TO PROGRESS EASTWARD
LATER THIS EVENING AND OVERNIGHT...COVERING MOST IF NOT ALL OF THE
FORECAST AREA BY THURSDAY MORNING. SHORTWAVE LOCATED OVER EASTERN
MONTANA WILL PROVIDE ENOUGH LIFT FOR SOME LIGHT SNOW SHOWERS
MAINLY OVER THE SOUTHWEST. HOWEVER...WHEREVER WE HAVE THE STRATUS
WE CAN EXPECT A FEW FLURRIES. THIS IS CURRENTLY HANDLED WELL BY
PREVIOUS FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 352 PM CST WED DEC 17 2014
CURRENT SURFACE ANALYSIS PLACES HIGH OVER THE MIDWEST WITH TROUGH
MOVING TOWARDS THE SOUTHERN PLAINS. UPPER LEVEL ANALYSIS PLACES
RIDGE WORKING TOWARDS THE MIDWEST WITH COMPACT LOW LIFTING THROUGH
EASTERN MONTANA. BROAD LOW CLOUD COVER REMAINS OVER WESTERN NORTH
DAKOTA...THOUGH SOME HIGHER CLOUDS ARE ALSO MOVING THROUGH WITH
APPROACHING UPPER LOW.
FOR TONIGHT...CLOUD COVER OVER THE WEST WILL SPREAD TOWARDS THE
EAST THROUGH THE NIGHT. SOME LIGHT SNOW IS POSSIBLE WITH
APPROACHING UPPER LOW...MAINLY OVER THE SOUTHWEST...BUT WITH
LIMITED MOISTURE AVAILABLE ANY ACCUMULATIONS WILL BE QUITE LIGHT.
ELSEWHERE...FLURRIES REMAIN POSSIBLE.
ON THURSDAY...UPPER LOW CONTINUES TO SLOWLY WORK ITS WAY TO THE
EAST WHILE MILDER AIRMASS SLOWLY STARTS TO WORK ITS WAY INTO THE
AREA...BRINGING TEMPERATURES CLOSER TO AVERAGE. MODELS CONTINUE TO
KEEP MOISTURE IN PLACE OVER THE REGION KEEPING CLOUDY SKIES OVER
MOST LOCATIONS...WITH SOME CLEARING DEVELOPING OVER THE FAR WEST
IN THE AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 352 PM CST WED DEC 17 2014
QUIET THROUGH SATURDAY...ACTIVE END TO THE WEEKEND AND EARLY
HOLIDAY WEEK.
A WEAK SHORTWAVE TROUGH IS PROGGED TO SWING ACROSS SOUTHERN CANADA
SATURDAY/SUNDAY. THIS COULD SPARK SOME LIGHT SNOW SHOWERS ACROSS
NORTHERN NORTH DAKOTA. HOWEVER...IF ANY PRECIPITATION DOES DEVELOP
ONLY VERY LIGHT AMOUNTS SEEM POSSIBLE WITH THIS WAVE AS IT SHOULD BE
DISCONNECTED FROM THE MAIN PACIFIC MOISTURE FLOW THAT WILL ARRIVE
LATER SUNDAY INTO MONDAY.
SPEAKING OF SUNDAY INTO MONDAY...BROAD NORTHWEST FLOW AND A
LONGWAVE TROUGH IS EXPECTED TO DEVELOP ACROSS THE NORTHERN
PLAINS. THIS WILL LEAD TO A MUCH MORE ACTIVE WEATHER PERIOD. AT
THIS TIME IT APPEARS THE MOST SIGNIFICANT IMPACTS WITH THIS SYSTEM
WILL REMAIN JUST SOUTH AND EAST. HOWEVER...THE LATEST MODELS (12
UTC ECMWF/GFS) VARY GREATLY IN THE EVOLUTION OF THIS WAVE AND
PRECIPITATION PLACEMENT. THEREFORE...CLOSE ATTENTION WILL BE GIVEN
TO FOLLOWING MODEL RUNS AND THE EVOLUTION OF THIS SIGNIFICANT WAVE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1212 AM CST THU DEC 18 2014
IFR STRATUS CONTINUES AT KDIK WITH MVFR STRATUS AT KDIK. LOW STRATUS
IS EXPECTED TO MOVE INTO CENTRAL NORTH DAKOTA (KBIS-KMOT) 07-10 UTC
AND INTO KJMS 13-16 UTC. THE LOW STRATUS IS EXPECTED TO LINGER AT
ALL AERODROMES THROUGH THE FORECAST PERIOD. COULD SEE SOME LIFTING
AT KDIK LATE IN THE PERIOD BUT FOR NOW WILL KEEP THE LOW CLOUDS AT
KDIK THROUGH 06 UTC.
A COUPLE SHORTWAVES ROTATING AROUND AN UPPER LOW...WHICH TRACKS EAST
ACROSS THE FORECAST AREA THROUGH THURSDAY WILL PROVIDE PERIOD OF
LIGHT SNOW. THE FIRST IS EXPECTED TO BRING SOME POSSIBLE LIGHT SNOW
TO KISN AND KMOT LATE TONIGHT. THE SECOND WAVE WILL PROVIDE A CHANCE
OF LIGHT SNOW ACROSS THE SOUTHERN TAF SITES...KDIK AROUND 10-16
UTC...KBIS AROUND 14-20 UTC AND KJMS AROUND 18-24 UTC. DID ADD A
TEMPO AT KDIK AND KBIS FOR SOME LOWER CEILINGS/VSBYS IN SNOW
SHOWERS. WILL HOLD OFF ON LOWER CIGS/VSBYS FOR KJMS AT THIS TIME AS
IT`S PRETTY FAR OUT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...JJS
LONG TERM...AJ
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1212 AM CST THU DEC 18 2014
.UPDATE...
ISSUED AT 1212 AM CST THU DEC 18 2014
LATEST WATER VAPOR IMAGERY LOOP PLACES AN UPPER LOW CIRCULATING JUST
SOUTH OF WILLISTON WITH A SHORTWAVE MOVING INTO THE BASE OF THE
TROUGH...LOCATED ACROSS SOUTHEAST MONTANA. THIS SHORTWAVE IS
FORECAST TO PROPAGATE SLOWLY EAST OVERNIGHT/THURSDAY...BEING LOCATED
BETWEEN DICKINSON AND BISMARCK BY 12Z...AND BETWEEN BISMARCK AND
JAMESTOWN BY 18Z THURSDAY. THE LATEST RAP13 BUFKIT SOUNDINGS FOR
KDIK/KBIS/KJMS INDICATE ENOUGH OMEGA/LIFT IN THE LOW LEVEL SATURATED
LAYER WITH RESPECT TO ICE. AS THE FROST POINT EXCEEDS THE
TEMPERATURE...SNOW PRODUCTION WILL RESULT IN THE SUPERSATURATED
ENVIRONMENT FOR A MENTION OF ISOLATED TO SCATTERED SNOW
SHOWERS/MEASURABLE AMOUNTS OVERNIGHT INTO THURSDAY AFTERNOON AS IT
SLOWLY MOVES EAST. HAVE UPDATED THE GRIDS FOR THIS FEATURE AND WILL
MONITOR AS IT EVOLVES THROUGH THE EARLY MORNING. THINKING IS ONE TO
TWO TENTHS OF AN INCH OF SNOW POSSIBLE ACROSS PORTIONS SOUTHERN
NORTH DAKOTA. SCATTERED FLURRIES STILL A GOOD BET WITH THE ACTUAL
UPPER LOW IN THE NORTHWEST AND NORTH CENTRAL OVERNIGHT AND WILL
CONTINUE WITH THIS IDEA.
UPDATE ISSUED AT 949 PM CST WED DEC 17 2014
MAIN ISSUE LATE THIS EVENING WILL BE LIGHT SNOW/FLURRY CHANCES.
TEMPERATURES WILL BE A HASSLE AGAIN ALONG THE BORDER BETWEEN THE
LOW CLOUDS AND CLEAR SKIES OVER CENTRAL ND...BUT TREND SEEMS
REASONABLE SO NO BIG CHANGES HERE.
LATEST 00 UTC NAM AND 02 UTC RAP SHOW A COUPLE SHORTWAVE IMPULSES
ROTATING AROUND AN UPPER LOW OVER EASTERN MONTANA. THE LEAD WAVE
IS AIDING IN THE DEVELOPMENT OF A SMALL BAND OF SNOW SHOWERS
LIFTING NORTHWARD THROUGH SOUTHWEST INTO CENTRAL NORTH DAKOTA.
GROUND REPORTS ARE INDICATING A BRIEF PERIOD OF SNOW SHOWERS WITH
NO SIGNIFICANT ACCUMULATIONS. WITH THE SMALL BAND LIFTING QUICKLY
NORTH...OPTED TO KEEP THIS AS A CONTINUED MENTION OF FLURRIES AS
GETTING A HUNDREDTH OF AN INCH IS NOT LIKELY.
LATER TONIGHT AND INTO THURSDAY MORNING A STRONGER SHORTWAVE MOVES
WEST ALONG THE NORTH DAKOTA/SOUTH DAKOTA BORDER. ALTHOUGH RAP/NAM
QPF IS CURRENTLY NIL...THE RAP/HRRR ARE SHOWING SOME LIGHT RADAR
REFLECTIVITIES DEVELOPING OVER SOUTHWEST NORTH DAKOTA IN THE 07-12
UTC TIMEFRAME. THINKING AS WE GO THROUGH A FEW MORE ITERATIONS OF
THE RAP/HRRR...THIS MAY CONTINUE TO PROGRESS INTO THE SOUTH
CENTRAL DURING THE MORNING HOURS...AND POSSIBLY INCREASE GIVEN THE
STRENGTH OF THE SHORTWAVE. WITH A MOIST BOUNDARY LAYER AND
INCREASING SEEDER-FEEDER MECHANISM WITH INCREASING MID LEVEL
CLOUDS...HAVE EXTENDED FLURRIES THROUGH THURSDAY MORNING ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. THINK MID SHIFT WILL HAVE THE
TIME TO RE-EVALUATE AND ADD A MENTION OF LIGHT SNOW FOR THE
MORNING HOURS IF NEEDED. ACCUMULATIONS WILL REMAIN LIGHT BUT THIS
SECOND WAVE LOOKS STRONG ENOUGH TO GIVE SOME OF US A LITTLE MORE
THAN JUST FLURRIES.
UPDATE ISSUED AT 551 PM CST WED DEC 17 2014
LOW STRATUS REMAINS ACROSS MUCH OF WESTERN AND CENTRAL NORTH
DAKOTA...AND WILL ONCE AGAIN BE A CONCERN FOR OVERNIGHT LOW
TEMPERATURES. DO EXPECT THE STRATUS TO BEGIN TO PROGRESS EASTWARD
LATER THIS EVENING AND OVERNIGHT...COVERING MOST IF NOT ALL OF THE
FORECAST AREA BY THURSDAY MORNING. SHORTWAVE LOCATED OVER EASTERN
MONTANA WILL PROVIDE ENOUGH LIFT FOR SOME LIGHT SNOW SHOWERS
MAINLY OVER THE SOUTHWEST. HOWEVER...WHEREVER WE HAVE THE STRATUS
WE CAN EXPECT A FEW FLURRIES. THIS IS CURRENTLY HANDLED WELL BY
PREVIOUS FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 352 PM CST WED DEC 17 2014
CURRENT SURFACE ANALYSIS PLACES HIGH OVER THE MIDWEST WITH TROUGH
MOVING TOWARDS THE SOUTHERN PLAINS. UPPER LEVEL ANALYSIS PLACES
RIDGE WORKING TOWARDS THE MIDWEST WITH COMPACT LOW LIFTING THROUGH
EASTERN MONTANA. BROAD LOW CLOUD COVER REMAINS OVER WESTERN NORTH
DAKOTA...THOUGH SOME HIGHER CLOUDS ARE ALSO MOVING THROUGH WITH
APPROACHING UPPER LOW.
FOR TONIGHT...CLOUD COVER OVER THE WEST WILL SPREAD TOWARDS THE
EAST THROUGH THE NIGHT. SOME LIGHT SNOW IS POSSIBLE WITH
APPROACHING UPPER LOW...MAINLY OVER THE SOUTHWEST...BUT WITH
LIMITED MOISTURE AVAILABLE ANY ACCUMULATIONS WILL BE QUITE LIGHT.
ELSEWHERE...FLURRIES REMAIN POSSIBLE.
ON THURSDAY...UPPER LOW CONTINUES TO SLOWLY WORK ITS WAY TO THE
EAST WHILE MILDER AIRMASS SLOWLY STARTS TO WORK ITS WAY INTO THE
AREA...BRINGING TEMPERATURES CLOSER TO AVERAGE. MODELS CONTINUE TO
KEEP MOISTURE IN PLACE OVER THE REGION KEEPING CLOUDY SKIES OVER
MOST LOCATIONS...WITH SOME CLEARING DEVELOPING OVER THE FAR WEST
IN THE AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 352 PM CST WED DEC 17 2014
QUIET THROUGH SATURDAY...ACTIVE END TO THE WEEKEND AND EARLY
HOLIDAY WEEK.
A WEAK SHORTWAVE TROUGH IS PROGGED TO SWING ACROSS SOUTHERN CANADA
SATURDAY/SUNDAY. THIS COULD SPARK SOME LIGHT SNOW SHOWERS ACROSS
NORTHERN NORTH DAKOTA. HOWEVER...IF ANY PRECIPITATION DOES DEVELOP
ONLY VERY LIGHT AMOUNTS SEEM POSSIBLE WITH THIS WAVE AS IT SHOULD BE
DISCONNECTED FROM THE MAIN PACIFIC MOISTURE FLOW THAT WILL ARRIVE
LATER SUNDAY INTO MONDAY.
SPEAKING OF SUNDAY INTO MONDAY...BROAD NORTHWEST FLOW AND A
LONGWAVE TROUGH IS EXPECTED TO DEVELOP ACROSS THE NORTHERN
PLAINS. THIS WILL LEAD TO A MUCH MORE ACTIVE WEATHER PERIOD. AT
THIS TIME IT APPEARS THE MOST SIGNIFICANT IMPACTS WITH THIS SYSTEM
WILL REMAIN JUST SOUTH AND EAST. HOWEVER...THE LATEST MODELS (12
UTC ECMWF/GFS) VARY GREATLY IN THE EVOLUTION OF THIS WAVE AND
PRECIPITATION PLACEMENT. THEREFORE...CLOSE ATTENTION WILL BE GIVEN
TO FOLLOWING MODEL RUNS AND THE EVOLUTION OF THIS SIGNIFICANT WAVE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1212 AM CST THU DEC 18 2014
IFR STRATUS CONTINUES AT KDIK WITH MVFR STRATUS AT KDIK. LOW STRATUS
IS EXPECTED TO MOVE INTO CENTRAL NORTH DAKOTA (KBIS-KMOT) 07-10 UTC
AND INTO KJMS 13-16 UTC. THE LOW STRATUS IS EXPECTED TO LINGER AT
ALL AERODROMES THROUGH THE FORECAST PERIOD. COULD SEE SOME LIFTING
AT KDIK LATE IN THE PERIOD BUT FOR NOW WILL KEEP THE LOW CLOUDS AT
KDIK THROUGH 06 UTC.
A COUPLE SHORTWAVES ROTATING AROUND AN UPPER LOW...WHICH TRACKS EAST
ACROSS THE FORECAST AREA THROUGH THURSDAY WILL PROVIDE PERIOD OF
LIGHT SNOW. THE FIRST IS EXPECTED TO BRING SOME POSSIBLE LIGHT SNOW
TO KISN AND KMOT LATE TONIGHT. THE SECOND WAVE WILL PROVIDE A CHANCE
OF LIGHT SNOW ACROSS THE SOUTHERN TAF SITES...KDIK AROUND 10-16
UTC...KBIS AROUND 14-20 UTC AND KJMS AROUND 18-24 UTC. DID ADD A
TEMPO AT KDIK AND KBIS FOR SOME LOWER CEILINGS/VSBYS IN SNOW
SHOWERS. WILL HOLD OFF ON LOWER CIGS/VSBYS FOR KJMS AT THIS TIME AS
IT`S PRETTY FAR OUT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...JJS
LONG TERM...AJ
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
345 PM EST THU DEC 18 2014
.SYNOPSIS...
A WEAKENING UPPER LEVEL DISTURBANCE MOVING THROUGH THE OHIO VALLEY
WILL RESULT IN A FEW SNOW FLURRIES OR SNOW SHOWERS THIS EVENING.
WEAK SURFACE HIGH PRESSURE WILL THEN PUSH SLOWLY EAST ACROSS THE
REGION THROUGH THE WEEKEND...LEADING TO PRIMARILY DRY CONDITIONS
AND NEAR NORMAL TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
UPR LVL S/WV WILL PASS EAST ACRS OUR REGION THROUGH THIS EVENING.
FORCING IS WEAK WITH MOST AREAS JUST SEEING A FEW FLURRIES. THERE
COULD BE A FEW SNOW SHOWERS WITH JUST A LIGHT DUSTING ALONG THE
I-70 CORRIDOR WHERE DEEPEST MOISTURE WILL INTERSECT WEAK FORCING.
LOW LEVEL CLOUDS WILL CONTINUE TO BE AN ISSUE AS THE RAP MODEL
SHOWS REGION STAYING PRETTY MUCH OVERCAST OVERNIGHT. LOWS WILL
DROP INTO THE LOWER AND MID 20S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
WEAK SFC HIGH PRESSURE WILL SLOWLY BUILD INTO THE AREA ON FRIDAY.
DESPITE THIS FEATURE...IT LOOKS LIKE LOW LEVEL MOISTURE WILL HANG
AROUND AS IT BECOMES TRAPPED UNDERNEATH THE HIGH. WILL CONTINUE
WITH MAINLY CLOUDY SKIES. HIGHS WILL RANGE FROM THE LOWER TO MID
30S.
FOR FRIDAY NIGHT INTO SATURDAY...LATEST MODEL FORECASTS KEEP THE
AFFECTS OF AN UPR LVL S/WV TO OUR SOUTH WHILE SFC RIDGING REMAINS
IN PLACE. IT IS DIFFICULT TO KNOW IF THE LOW LEVEL CLOUDS WILL
ERODE DURING THIS TIME FRAME. HOWEVER...WITH AN INCREASE IN MID
AND HIGH LEVEL MOISTURE...IT WILL LIKELY REMAIN MOSTLY CLOUDY. IT
WILL BE A LITTLE WARMER ON SATURDAY WITH HIGHS IN THE MID AND
UPPER 30S.
BY SATURDAY NIGHT...HIGH PRESSURE WILL CONTINUE TO EXTEND ACROSS
THE GREAT LAKES AND OHIO VALLEY WHILE A WEAK UPR LVL S/WV PASSES
ACRS THE SOUTHERN GREAT LAKES. PARTLY CLOUDY SKIES ARE EXPECTED.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE CENTERED TO THE NORTHEAST WILL BRING DRY WEATHER ON
SUNDAY. INCREASING MOISTURE AND LIFT WELL AHEAD OF DEVELOPING LOW
PRESSURE MAY PRODUCE LIGHT RAIN AND SNOW ON MONDAY. AS THE LOW MOVES
TO LAKE MICHIGAN ON TUESDAY...RAIN WILL BE LIKELY IN A CONCENTRATED
BAND OF ISENTROPIC LIFT EXTENDING SOUTHEAST FROM THE LOW CENTER.
ENERGY WILL TRANSFER TO A COASTAL LOW ON WEDNESDAY...LEAVING THE
AREA IN A BRISK AND COLDER NORTHWEST FLOW OF DECREASING MOISTURE AND
FORCING. THIS WILL BRING AN END TO STEADY RAIN AND SNOW...WITH
SCATTERED SNOW SHOWERS THEN LINGERING INTO THURSDAY. NORTHERN
LOCATIONS SEEM TO HAVE THE BEST CHANCE FOR LIGHT SNOW ACCUMULATIONS.
AFTER NEAR NORMAL HIGHS AROUND 40 ON SUNDAY...WARM ADVECTION AHEAD
OF THE LOW WILL ALLOW ABOVE NORMAL HIGHS IN THE 40S ON MONDAY AND
TUESDAY. EXPECT EARLY HIGHS NEAR 40 ON WEDNESDAY...DROPPING TO
BELOW NORMAL 30S UNDER COLD ADVECTION ON THURSDAY.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
PERSISTENT MVFR CLOUD DECK CONTINUES TO REMAIN IN PLACE ACRS THE
TAFS EARLY THIS AFTN. WEAKENING MID LEVEL S/W TRACKING THRU THE
OHIO VALLEY WILL RESULT IN SNOW SHOWERS AND FLURRIES WITH THE BEST
COVERAGE ACRS KDAY/KCMH/KLCK. MVFR VSBYS POSSIBLE AT THESE TAF
SITES BUT SINCE PROBABILITY AND DURATION WILL BE LIMITED HAVE JUST
MENTIONED -SN. THERE MAY BE SOME IMPROVEMENT TO CIGS ESPECIALLY AT
KCVG/KLUK AFTER THE PASSAGE OF THIS S/W FOR A BRIEF PERIOD. HAVE
FOLLOWED SOLN CLOSER TO LATEST RAP BRINGING MVFR CIGS BACK OR A LTL
LOWER THIS EVENING. HAVE SHOWN IMPROVEMENT TO VFR AT KCVG/KLUK
FRIDAY AFTN WITH MVFR CIGS HOLDING AT THE REMAINDER OF THE TAF SITES.
NW TO W WINDS OF UNDER 10 KNOTS ARE EXPECTED THROUGH THE FCST
PERIOD.
OUTLOOK...MVFR CEILINGS MAY CONTINUE INTO FRIDAY. MVFR CEILINGS
AND VISIBILITIES ARE POSSIBLE ON SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...CONIGLIO
AVIATION...AR
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1247 PM EST THU DEC 18 2014
.SYNOPSIS...
A WEAKENING UPPER LEVEL DISTURBANCE MOVING THROUGH THE OHIO VALLEY
WILL LEAD TO A FEW SNOW FLURRIES THIS AFTERNOON INTO THIS EVENING.
WEAK SURFACE HIGH PRESSURE WILL THEN PUSH SLOWLY EAST ACROSS THE
REGION THROUGH THE WEEKEND...LEADING TO PRIMARILY DRY CONDITIONS
AND NEAR NORMAL TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MID LEVEL SHORTWAVE TO TRACK FROM THE CENTRAL PLAINS EAST ACROSS
THE OHIO VALLEY TODAY. GOOD DEAL OF LOW CLOUDS REMAIN IN PLACE
THIS MORNING. 12Z ILN SOUNDING SHOWS THIS SHALLOW MOISTURE TRAPPED
BELOW AN INVERSION AROUND 880 MB. EVEN WITH SOME EROSION OF THESE
LOW CLOUDS...MID LEVEL CLOUDS ASSOCIATED WITH THE AFOREMENTIONED
S/W WILL OVERSPREAD THE REGION. THIS S/W WILL DAMPEN AND WEAKEN
AS IT PASSES THRU THE OHIO VALLEY. NUMERICAL MODELS SUGGEST
WEAK LIFT IN THE MID LEVELS DEVELOPING EARLY AFTERNOON.
EXPECT THIS TO RESULT IN SOME FLURRIES OR EVEN SOME ISOLD SNOW
SHOWER ACTIVITY. HAVE CONTINUED WITH JUST A CHANCE OF FLURRIES
THIS AFTERNOON. GIVEN THE COMBINATION OF THE CLOUDS AND MAINLY
NEUTRAL LOW LEVEL TEMPERATURE ADVECTION THROUGH THE DAY...
EXPECT A SMALL DIURNAL RISE TO READINGS TODAY. HAVE HIGHS FROM THE
LOWER 30S NORTH TO THE MID 30S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
WE COULD SEE A FEW FLURRIES LINGER INTO THIS EVENING...BUT FOR THE
MOST PART EXPECT DRY CONDITIONS TONIGHT THROUGH FRIDAY AS A WEAK
AREA OF HIGH PRESSURE BUILDS ACROSS THE GREAT LAKES REGION. THE
MODELS CONTINUE TO TREND FARTHER SOUTH WITH THE LOW PRESSURE
SYSTEM MOVING THROUGH THE SOUTHEASTERN UNITED STATES FRIDAY NIGHT
INTO SATURDAY. WITH THE BETTER FORCING GENERALLY REMAINING TO OUR
SOUTHEAST...WILL TRIM BACK POPS AND JUST ALLOW FOR A TOKEN SLIGHT
CHANCE INTO OUR FAR SOUTHEAST THROUGH THE DAY ON SATURDAY. WITH
THIS FARTHER SOUTH SOLUTION...WE WOULD BE COLD ENOUGH FOR ANY PCPN
TO BE ALL SNOW. FAIRLY SEASONABLE TEMPERATURES ARE EXPECTED THROUGH THE
END OF THE WEEK...WITH HIGHS BOTH FRIDAY AND SATURDAY IN THE MID TO
UPPER 30S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE AND A COOL AIRMASS SHOULD ALLOW DRY WEATHER ON
SUNDAY. LIGHT PRECIP WILL BE POSSIBLE MONDAY EXTENDING FROM A
TROUGH ALONG THE EAST COAST.
WE MAY BEGIN TO FEEL THE EFFECTS OF A POWERFUL LOW PRESSURE SYSTEM
ON TUESDAY. HAVE LESS THAN AVERAGE AMOUNT OF CONFIDENCE DUE TO MODEL
DIFFERENCES FROM RUN TO RUN. AT THIS POINT IT APPEARS THE LOW WILL
DEVELOP OVER THE SOUTHERN PLAINS ON TUESDAY...BEFORE LIFTING THROUGH
OHIO TO THE GREAT LAKES ON WEDNESDAY. THE LOW MAY FEATURE A VERY
TIGHT PRESSURE GRADIENT SURROUNDING ITS DEEP CENTER...PRODUCING
STRONG WINDS. COPIOUS MOISTURE FEEDING FROM THE TROPICS AND FROM THE
ATLANTIC OCEAN COULD ADVECT AROUND THE LOW. CURRENT TEMPERATURE
FORECAST ALLOWS RAIN TUESDAY INTO WEDNESDAY...CHANGING TO SNOW LATER
WEDNESDAY AS COLDER AIR WRAPS IN BEHIND THE LOW.
TEMPERATURES WILL BE RELATIVELY CLOSE TO NORMAL FOR THE MOST PART.
HIGHS WILL BE A COUPLE DEGREES WARMER FOR SUNDAY AND MONDAY UNDER
NEUTRAL TO WEAK WARM ADVECTION. READINGS ON TUESDAY AND WEDNESDAY
WILL BE DEPENDENT ON THE POSITION OF THE ANTICIPATED STRONG LOW.
WARM ADVECTION AHEAD OF THE LOW COULD BRING HIGHS UP INTO THE MID
40S ON TUESDAY...OR EVEN HIGHER IF THE WARMER MEX GUIDANCE
VERIFIES. HIGHS COULD SLIP TO AROUND 40 ON WEDNESDAY IN COLD
ADVECTION BEHIND THE LOW.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
PERSISTENT MVFR CLOUD DECK CONTINUES TO REMAIN IN PLACE ACRS THE
TAFS EARLY THIS AFTN. WEAKENING MID LEVEL S/W TRACKING THRU THE
OHIO VALLEY WILL RESULT IN SNOW SHOWERS AND FLURRIES WITH THE BEST
COVERAGE ACRS KDAY/KCMH/KLCK. MVFR VSBYS POSSIBLE AT THESE TAF
SITES BUT SINCE PROBABILITY AND DURATION WILL BE LIMITED HAVE JUST
MENTIONED -SN. THERE MAY BE SOME IMPROVEMENT TO CIGS ESPECIALLY AT
KCVG/KLUK AFTER THE PASSAGE OF THIS S/W FOR A BRIEF PERIOD. HAVE
FOLLOWED SOLN CLOSER TO LATEST RAP BRINGING MVFR CIGS BACK OR A LTL
LOWER THIS EVENING. HAVE SHOWN IMPROVEMENT TO VFR AT KCVG/KLUK
FRIDAY AFTN WITH MVFR CIGS HOLDING AT THE REMAINDER OF THE TAF SITES.
NW TO W WINDS OF UNDER 10 KNOTS ARE EXPECTED THROUGH THE FCST
PERIOD.
OUTLOOK...MVFR CEILINGS MAY CONTINUE INTO FRIDAY. MVFR CEILINGS
AND VISIBILITIES ARE POSSIBLE ON SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JGL
NEAR TERM...JGL/AR
SHORT TERM...JGL
LONG TERM...CONIGLIO
AVIATION...AR
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1021 AM EST THU DEC 18 2014
.SYNOPSIS...
A WEAKENING UPPER LEVEL DISTURBANCE MOVING THROUGH THE OHIO VALLEY
WILL LEAD TO A FEW SNOW FLURRIES THIS AFTERNOON INTO THIS EVENING.
WEAK SURFACE HIGH PRESSURE WILL THEN PUSH SLOWLY EAST ACROSS THE
REGION THROUGH THE WEEKEND...LEADING TO PRIMARILY DRY CONDITIONS
AND NEAR NORMAL TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MID LEVEL SHORTWAVE TO TRACK FROM THE CENTRAL PLAINS EAST ACROSS
THE OHIO VALLEY TODAY. GOOD DEAL OF LOW CLOUDS REMAIN IN PLACE
THIS MORNING. 12Z ILN SOUNDING SHOWS THIS SHALLOW MOISTURE TRAPPED
BELOW AN INVERSION AROUND 880 MB. EVEN WITH SOME EROSION OF THESE
LOW CLOUDS...MID LEVEL CLOUDS ASSOCIATED WITH THE AFOREMENTIONED
S/W WILL OVERSPREAD THE REGION. THIS S/W WILL DAMPEN AND WEAKEN
AS IT PASSES THRU THE OHIO VALLEY. NUMERICAL MODELS SUGGEST
WEAK LIFT IN THE MID LEVELS DEVELOPING EARLY AFTERNOON.
EXPECT THIS TO RESULT IN SOME FLURRIES OR EVEN SOME ISOLD SNOW
SHOWER ACTIVITY. HAVE CONTINUED WITH JUST A CHANCE OF FLURRIES
THIS AFTERNOON. GIVEN THE COMBINATION OF THE CLOUDS AND MAINLY
NEUTRAL LOW LEVEL TEMPERATURE ADVECTION THROUGH THE DAY...
EXPECT A SMALL DIURNAL RISE TO READINGS TODAY. HAVE HIGHS FROM THE
LOWER 30S NORTH TO THE MID 30S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
WE COULD SEE A FEW FLURRIES LINGER INTO THIS EVENING...BUT FOR THE
MOST PART EXPECT DRY CONDITIONS TONIGHT THROUGH FRIDAY AS A WEAK
AREA OF HIGH PRESSURE BUILDS ACROSS THE GREAT LAKES REGION. THE
MODELS CONTINUE TO TREND FARTHER SOUTH WITH THE LOW PRESSURE
SYSTEM MOVING THROUGH THE SOUTHEASTERN UNITED STATES FRIDAY NIGHT
INTO SATURDAY. WITH THE BETTER FORCING GENERALLY REMAINING TO OUR
SOUTHEAST...WILL TRIM BACK POPS AND JUST ALLOW FOR A TOKEN SLIGHT
CHANCE INTO OUR FAR SOUTHEAST THROUGH THE DAY ON SATURDAY. WITH
THIS FARTHER SOUTH SOLUTION...WE WOULD BE COLD ENOUGH FOR ANY PCPN
TO BE ALL SNOW. FAIRLY SEASONABLE TEMPERATURES ARE EXPECTED THROUGH THE
END OF THE WEEK...WITH HIGHS BOTH FRIDAY AND SATURDAY IN THE MID TO
UPPER 30S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE AND A COOL AIRMASS SHOULD ALLOW DRY WEATHER ON
SUNDAY. LIGHT PRECIP WILL BE POSSIBLE MONDAY EXTENDING FROM A
TROUGH ALONG THE EAST COAST.
WE MAY BEGIN TO FEEL THE EFFECTS OF A POWERFUL LOW PRESSURE SYSTEM
ON TUESDAY. HAVE LESS THAN AVERAGE AMOUNT OF CONFIDENCE DUE TO MODEL
DIFFERENCES FROM RUN TO RUN. AT THIS POINT IT APPEARS THE LOW WILL
DEVELOP OVER THE SOUTHERN PLAINS ON TUESDAY...BEFORE LIFTING THROUGH
OHIO TO THE GREAT LAKES ON WEDNESDAY. THE LOW MAY FEATURE A VERY
TIGHT PRESSURE GRADIENT SURROUNDING ITS DEEP CENTER...PRODUCING
STRONG WINDS. COPIOUS MOISTURE FEEDING FROM THE TROPICS AND FROM THE
ATLANTIC OCEAN COULD ADVECT AROUND THE LOW. CURRENT TEMPERATURE
FORECAST ALLOWS RAIN TUESDAY INTO WEDNESDAY...CHANGING TO SNOW LATER
WEDNESDAY AS COLDER AIR WRAPS IN BEHIND THE LOW.
TEMPERATURES WILL BE RELATIVELY CLOSE TO NORMAL FOR THE MOST PART.
HIGHS WILL BE A COUPLE DEGREES WARMER FOR SUNDAY AND MONDAY UNDER
NEUTRAL TO WEAK WARM ADVECTION. READINGS ON TUESDAY AND WEDNESDAY
WILL BE DEPENDENT ON THE POSITION OF THE ANTICIPATED STRONG LOW.
WARM ADVECTION AHEAD OF THE LOW COULD BRING HIGHS UP INTO THE MID
40S ON TUESDAY...OR EVEN HIGHER IF THE WARMER MEX GUIDANCE
VERIFIES. HIGHS COULD SLIP TO AROUND 40 ON WEDNESDAY IN COLD
ADVECTION BEHIND THE LOW.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
A PERSISTENT MVFR CLOUD DECK IS LIKELY TO REMAIN IN PLACE ACROSS
THE TAF SITES INTO THE AFTERNOON. AT THAT TIME THE DECK SHOULD
BREAK...BECOMING VFR....AS A WEAK UPPER LEVEL SYSTEM APPROACHES
THE AREA WITH ITS ASSOCIATED MID AND HIGH CLOUDS. AFTER THIS THERE
CONTINUES TO BE MAJOR DISAGREEMENT IN THE NUMERICAL GUIDANCE. SVRL
MODELS BRING MVFR CIGS BACK INTO THE AREA THIS EVENING WHILE
OTHERS CONTINUE WITH A DECK OF VFR CIGS BTWN FL050 AND 070. HAVE
CHOSEN TO GO WITH THE RAP SOLUTION WHICH SEEMS TO HAVE
SOMEWHAT...ALTHOUGH NOT PERFECT HANDLE ON THE SITUATION. WHILE
MOISTURE WITH THIS NEXT SYSTEM WILL BE LACKING IN TERMS OF
PCPN...FLURRIES ARE EXPECTED THIS AFTERNOON AND EVENING. SINCE NO
VSBY RESTRICTIONS ARE EXPECTED AND THE TIMING DURING THIS PERIOD
WILL BE VARIABLE HAVE NOT INCLUDED THIS MENTION IN THE FCST.
W WINDS OF UNDER 10 KNOTS ARE EXPECTED THROUGH THE FCST PERIOD.
OUTLOOK...MVFR CEILINGS MAY CONTINUE INTO FRIDAY. MVFR CEILINGS
AND VISIBILITIES ARE POSSIBLE ON SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JGL
NEAR TERM...JGL/AR
SHORT TERM...JGL
LONG TERM...CONIGLIO
AVIATION...HAYDU
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
659 AM EST THU DEC 18 2014
.SYNOPSIS...
A WEAKENING UPPER LEVEL DISTURBANCE MOVING THROUGH THE OHIO VALLEY
WILL LEAD TO A FEW SNOW FLURRIES THIS AFTERNOON INTO THIS EVENING.
WEAK SURFACE HIGH PRESSURE WILL THEN PUSH SLOWLY EAST ACROSS THE
REGION THROUGH THE WEEKEND...LEADING TO PRIMARILY DRY CONDITIONS
AND NEAR NORMAL TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PLENTY OF LOW CLOUDS REMAIN IN PLACE ACROSS THE AREA EARLY THIS
MORNING...ALTHOUGH WE ARE SEEING PERHAPS A BIT OF EROSION IN THESE JUST
OFF TO OUR SOUTHWEST. THIS IS IN THE AREA OF SOME ADVANCING MID
LEVEL MOISTURE THAT WILL WORK EAST ACROSS OUR AREA LATER THIS
MORNING AND INTO THIS AFTERNOON IN ASSOCIATION WITH A WEAKENING
MID LEVEL SHORT WAVE. AS A RESULT...WOULD EXPECT ANY DISSIPATION
IN THE LOWER LEVEL CLOUDS TO BE OVERCOME BY THE MID LEVEL
CLOUDS...RESULTING IN CLOUDY SKIES THROUGH THE DAY. MODELS ARE
SUGGESTING SOME WEAK LIFT AT AND ABOVE 700 MB DEVELOPING THROUGH
EARLY AFTERNOON AND EXPECT THIS TO RESULT IN SOME FLURRY OR
POSSIBLY EVEN SOME SNOW SHOWER ACTIVITY THIS AFTERNOON. THERE IS
ACTUALLY A PERIOD FROM ABOUT 18Z TO 21Z THIS AFTERNOON WHERE THE
DENDRITIC GROWTH ZONE IS MAXIMIZED IN THE AREA OF BEST LIFT
ACROSS PARTS OF OUR SOUTHERN FA. HOWEVER...GIVEN THAT THE MOISTURE
IS PRETTY LIMITED AND RATHER DRY BETWEEN ABOUT 950 MB AND 700
MB...WILL CONTINUE WITH JUST A CHANCE OF FLURRIES THIS AFTERNOON.
GIVEN THE COMBINATION OF THE CLOUDS AND MAINLY NEUTRAL LOW LEVEL
TEMPERATURE ADVECTION THROUGH THE DAY...ONLY EXPECT A FEW DEGREE
BUMP UP IN TEMPERATURES THROUGH THIS AFTERNOON WITH HIGHS
GENERALLY IN THE LOW TO POSSIBLY MID 30S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
WE COULD SEE A FEW FLURRIES LINGER INTO THIS EVENING...BUT FOR THE
MOST PART EXPECT DRY CONDITIONS TONIGHT THROUGH FRIDAY AS A WEAK
AREA OF HIGH PRESSURE BUILDS ACROSS THE GREAT LAKES REGION. THE
MODELS CONTINUE TO TREND FARTHER SOUTH WITH THE LOW PRESSURE
SYSTEM MOVING THROUGH THE SOUTHEASTERN UNITED STATES FRIDAY NIGHT
INTO SATURDAY. WITH THE BETTER FORCING GENERALLY REMAINING TO OUR
SOUTHEAST...WILL TRIM BACK POPS AND JUST ALLOW FOR A TOKEN SLIGHT
CHANCE INTO OUR FAR SOUTHEAST THROUGH THE DAY ON SATURDAY. WITH
THIS FARTHER SOUTH SOLUTION...WE WOULD BE COLD ENOUGH FOR ANY PCPN
TO BE ALL SNOW. FAIRLY SEASONABLE TEMPERATURES ARE EXPECTED THROUGH THE
END OF THE WEEK...WITH HIGHS BOTH FRIDAY AND SATURDAY IN THE MID TO
UPPER 30S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE AND A COOL AIRMASS SHOULD ALLOW DRY WEATHER ON
SUNDAY. LIGHT PRECIP WILL BE POSSIBLE MONDAY EXTENDING FROM A
TROUGH ALONG THE EAST COAST.
WE MAY BEGIN TO FEEL THE EFFECTS OF A POWERFUL LOW PRESSURE SYSTEM
ON TUESDAY. HAVE LESS THAN AVERAGE AMOUNT OF CONFIDENCE DUE TO MODEL
DIFFERENCES FROM RUN TO RUN. AT THIS POINT IT APPEARS THE LOW WILL
DEVELOP OVER THE SOUTHERN PLAINS ON TUESDAY...BEFORE LIFTING THROUGH
OHIO TO THE GREAT LAKES ON WEDNESDAY. THE LOW MAY FEATURE A VERY
TIGHT PRESSURE GRADIENT SURROUNDING ITS DEEP CENTER...PRODUCING
STRONG WINDS. COPIOUS MOISTURE FEEDING FROM THE TROPICS AND FROM THE
ATLANTIC OCEAN COULD ADVECT AROUND THE LOW. CURRENT TEMPERATURE
FORECAST ALLOWS RAIN TUESDAY INTO WEDNESDAY...CHANGING TO SNOW LATER
WEDNESDAY AS COLDER AIR WRAPS IN BEHIND THE LOW.
TEMPERATURES WILL BE RELATIVELY CLOSE TO NORMAL FOR THE MOST PART.
HIGHS WILL BE A COUPLE DEGREES WARMER FOR SUNDAY AND MONDAY UNDER
NEUTRAL TO WEAK WARM ADVECTION. READINGS ON TUESDAY AND WEDNESDAY
WILL BE DEPENDENT ON THE POSITION OF THE ANTICIPATED STRONG LOW.
WARM ADVECTION AHEAD OF THE LOW COULD BRING HIGHS UP INTO THE MID
40S ON TUESDAY...OR EVEN HIGHER IF THE WARMER MEX GUIDANCE
VERIFIES. HIGHS COULD SLIP TO AROUND 40 ON WEDNESDAY IN COLD
ADVECTION BEHIND THE LOW.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
A PERSISTENT MVFR CLOUD DECK IS LIKELY TO REMAIN IN PLACE ACROSS
THE TAF SITES INTO THE AFTERNOON. AT THAT TIME THE DECK SHOULD
BREAK...BECOMING VFR....AS A WEAK UPPER LEVEL SYSTEM APPROACHES
THE AREA WITH ITS ASSOCIATED MID AND HIGH CLOUDS. AFTER THIS THERE
CONTINUES TO BE MAJOR DISAGREEMENT IN THE NUMERICAL GUIDANCE. SVRL
MODELS BRING MVFR CIGS BACK INTO THE AREA THIS EVENING WHILE
OTHERS CONTINUE WITH A DECK OF VFR CIGS BTWN FL050 AND 070. HAVE
CHOSEN TO GO WITH THE RAP SOLUTION WHICH SEEMS TO HAVE
SOMEWHAT...ALTHOUGH NOT PERFECT HANDLE ON THE SITUATION. WHILE
MOISTURE WITH THIS NEXT SYSTEM WILL BE LACKING IN TERMS OF
PCPN...FLURRIES ARE EXPECTED THIS AFTERNOON AND EVENING. SINCE NO
VSBY RESTRICTIONS ARE EXPECTED AND THE TIMING DURING THIS PERIOD
WILL BE VARIABLE HAVE NOT INCLUDED THIS MENTION IN THE FCST.
W WINDS OF UNDER 10 KNOTS ARE EXPECTED THROUGH THE FCST PERIOD.
OUTLOOK...MVFR CEILINGS MAY CONTINUE INTO FRIDAY. MVFR CEILINGS
AND VISIBILITIES ARE POSSIBLE ON SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JGL
NEAR TERM...JGL
SHORT TERM...JGL
LONG TERM...CONIGLIO
AVIATION...HAYDU
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1259 AM EST THU DEC 18 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL NOSE INTO THE REGION TONIGHT. HOWEVER
ABUNDANT LOW LEVEL MOISTURE WILL RESULT IN A CONTINUATION OF MAINLY
CLOUDY SKIES. A WEAK UPPER LEVEL DISTURBANCE COULD LEAD TO A FEW
FLURRIES THURSDAY AFTERNOON INTO THURSDAY NIGHT. HIGH PRESSURE WILL
BUILD BACK IN OFFERING DRY CONDITIONS AND NEAR SEASONABLE
TEMPERATURES FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AN ELONGATED AREA OF HIGH PRESSURE IS CURRENTLY CENTERED WEST OF
THE OHIO VALLEY. THIS HIGH WILL NUDGE INTO THE AREA BY
MORNING...WITH COOL WNW FLOW ON ITS NORTH SIDE ALLOWING FOR A
RELATIVE MIN IN SURFACE/925MB TEMPS THAT WILL STRETCH FROM CENTRAL
OHIO TO MINNESOTA. TEMPERATURES HAVE BEEN COOLING OFF A LITTLE
FASTER THAN THE PREVIOUS FORECAST INDICATED...SO A SLIGHT DOWNWARD
ADJUSTMENT WAS MADE TO THE MIN TEMPERATURE GRID.
AS THE PRESSURE GRADIENT WEAKENS...WINDS WILL BECOME LIGHTER AS
THE OVERNIGHT HOURS PROGRESS. HOWEVER...THE DIRECTION OF FLOW WILL
NOT BE FAVORABLE FOR THE ADVECTION OF THE MOISTURE CURRENTLY OVER
THE MIDDLE AND UPPER OHIO VALLEY. THE 00Z KILN SOUNDING INDICATED
SATURATION BETWEEN 925MB AND 875MB...CAPTURED WELL ON THE NAM12
AND RAP13...BUT VERY POORLY ON THE GFS AND ECMWF. THE EROSION OF
THE SOUTHERN/WESTERN EDGE OF THESE CLOUDS HAS SLOWED OR
STOPPED...AND THE FORECAST FOR THE OVERNIGHT WILL REMAIN VERY
CLOUDY. HOWEVER...SOME SLIGHT WARMING IS EXPECTED TO BEGIN AT
900MB AFTER 06Z...WHICH MAY BE ENOUGH TO LEAD TO SOME BREAKS IN
THE CLOUDS CLOSER TO MORNING.
PREVIOUS FORECAST >
ELONGATED MID LEVEL LOW OVER THE GREAT LAKES TO SHIFT OFF INTO NEW
ENGLAND. A FEW ISOLD LINGERING FLURRIES IN THE LOW LEVEL CAA WILL
COME TO AN END EARLY. MID LEVEL FLOW BECOMES BRIEFLY NW AHEAD OF AN
UPSTREAM S/W RIDGE. SFC HIGH PRESSURE TO NOSE INTO THE OHIO VALLEY
OVERNIGHT IN REGION OF H5 CONFLUENCE. 12Z ILN SOUNDING SHOWS LOW
LEVEL MOISTURE TRAPPED BELOW AN INVERSION AROUND 850 MB. GFS IS
AGGRESSIVE WITH CLEARING LOW LEVEL MOISTURE. NAM AND RAP SOLNS KEEP
CLOUDS OVERNIGHT. WILL ALLOW A FEW BREAKS OVER THE SOUTH/SOUTHWEST
BUT LEAN TOWARD THE NAM/RAP SOLN. TEMPERATURES WILL BE CLOSE TO
NORMAL WITH LOWS FROM THE MID 20S NORTH TO THE UPPER 20S SOUTH.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
MID LEVEL S/W TO RIPPLE QUICKLY EAST FROM THE CENTRAL PLAINS
THROUGH THE OHIO VALLEY THURSDAY. THIS WEAK SHORTWAVE IS DAMPENING
AND CROSSING OVER THE SFC RIDGE. FORCING IS VERY WEAK AND IN THE
MID LEVELS. A FLURRY OR SPRINKLE IS NOT OUT OF THE QUESTION FROM A
MID DECK. FLURRIES/SPRINKLES ALREADY IN THE FORECAST...SO WILL
CONTINUE. TEMPERATURES WILL BE BELOW NORMAL WITH HIGHS FROM THE
LOWER 30S NORTH TO THE MID/UPR 30S SOUTH.
IN WESTERLY MID LEVEL FLOW REGIME...SFC HIGH PRESSURE TO BUILD
ACRS THE GREAT LAKES/OHIO VALLEY THURSDAY NIGHT/FRIDAY. A FEW
FLURRIES WILL REMAIN POSSIBLE THURSDAY EVENING BUT WILL COME TO AN
END WITH THE PASSAGE OF THE S/W. AS THE HIGH BUILD NOSES IN
EXPECT SOME PARTIAL CLEARING THURSDAY NIGHT. LOWS EXPECTED TO
RANGE FROM THE MID 20S NORTH TO THE UPPER 20S SOUTH.
EXPECT TO SEE MORE SUNSHINE FRIDAY WITH AN INCREASE IN HIGH LEVEL
MOISTURE LATE IN THE DAY. FRIDAYS HIGHS FROM THE MID 30S NORTH TO
NEAR 40 SOUTH.
CLOUDS WILL THICKEN AND INCREASE FRIDAY NIGHT AS SYSTEM APPROACHES
FROM THE SOUTHWEST. WILL KEEP FCST DRY FRIDAY NIGHT AS CONSENSUS
DOES NOT BRING MOISTURE IN UNTIL SATURDAY. LOWS FRIDAY NIGHT TO
RANGE FROM THE UPPER 20S NORTH TO THE LOWER 30S FAR SOUTH.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
FOR SATURDAY...LOOKS LIKE WE COULD SEE SNOW CHANGING TO RAIN AS LOW
PRESSURE TRAVELS NEAR THE GULF COAST. THE LOW HAS TRENDED FARTHER TO
THE SOUTH SO CUT BACK ON POPS AND PRECIP AMOUNTS. HIGH PRESSURE AND
A COOL AIRMASS SHOULD ALLOW DRY WEATHER ON SUNDAY. LIGHT PRECIP WILL
BE POSSIBLE MONDAY EXTENDING FROM A TROUGH ALONG THE EAST COAST.
WE MAY BEGIN TO FEEL THE EFFECTS OF A POWERFUL LOW PRESSURE SYSTEM
ON TUESDAY. HAVE LESS THAN AVERAGE AMOUNT OF CONFIDENCE DUE TO MODEL
DIFFERENCES FROM RUN TO RUN. AT THIS POINT IT APPEARS THE LOW WILL
DEVELOP OVER THE SOUTHERN PLAINS ON TUESDAY...BEFORE LIFTING THROUGH
OHIO TO THE GREAT LAKES ON WEDNESDAY. THE LOW MAY FEATURE A VERY
TIGHT PRESSURE GRADIENT SURROUNDING ITS DEEP CENTER...PRODUCING
STRONG WINDS. COPIOUS MOISTURE FEEDING FROM THE TROPICS AND FROM THE
ATLANTIC OCEAN COULD ADVECT AROUND THE LOW. CURRENT TEMPERATURE
FORECAST ALLOWS RAIN TUESDAY INTO WEDNESDAY...CHANGING TO SNOW LATER
WEDNESDAY AS COLDER AIR WRAPS IN BEHIND THE LOW.
TEMPERATURES WILL BE RELATIVELY CLOSE TO NORMAL FOR THE MOST PART.
HIGHS ARE FORECAST TO BE IN THE MID AND UPPER 30S SATURDAY...THEN A
COUPLE DEGREES WARMER FOR SUNDAY AND MONDAY UNDER NEUTRAL TO WEAK
WARM ADVECTION. READINGS ON TUESDAY AND WEDNESDAY WILL BE DEPENDENT
ON THE POSITION OF THE ANTICIPATED STRONG LOW. WARM ADVECTION AHEAD
OF THE LOW COULD BRING HIGHS UP INTO THE MID 40S ON TUESDAY...OR
EVEN HIGHER IF THE WARMER MEX GUIDANCE VERIFIES. HIGHS COULD SLIP TO
AROUND 40 ON WEDNESDAY IN COLD ADVECTION BEHIND THE LOW.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
A PERSISTENT MVFR CLOUD DECK IS LIKELY TO REMAIN IN PLACE ACROSS
THE TAF SITES INTO THE AFTERNOON. AT THAT TIME THE DECK SHOULD
BREAK AS A WEAK UPPER LEVEL SYSTEM APPROACHES THE AREA. HOWEVER
THE REPRIEVE WILL BE SHORT LIVE AS THE MVFR CIGS SHOULD RETURN
DURING THE EVENING. DURING THIS BREAK IN THE MVFR CIGS THERE WILL
BE MULTIPLE LAYERS OF CLOUDS AOB FL050 IN ASSOCIATION WITH THE
NEXT SYSTEM. WHILE MOISTURE WITH THIS NEXT SYSTEM WILL BE LACKING
IN TERMS OF PCPN...FLURRIES ARE EXPECTED THIS AFTERNOON AND
EVENING. SINCE NO VSBY RESTRICTIONS ARE EXPECTED AND THE TIMING
DURING THIS PERIOD WILL BE VARIABLE HAVE NOT INCLUDED THIS MENTION
IN THE FCST.
W WINDS OF UNDER 10 KNOTS ARE EXPECTED THROUGH THE FCST PERIOD.
OUTLOOK...MVFR CEILINGS MAY CONTINUE INTO FRIDAY. MVFR CEILINGS
AND VISIBILITIES ARE POSSIBLE ON SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...AR
NEAR TERM...HATZOS/AR
SHORT TERM...AR
LONG TERM...CONIGLIO
AVIATION...HAYDU
AREA FORECAST DISCUSSION
NWS MEDFORD OR
918 PM PST WED DEC 17 2014
.DISCUSSION...THE REMNANTS OF AN OCCLUDED FRONT ARE MOVING EAST
THIS EVENING WITH A SLOW MOVING BAND OF LIGHT PRECIPITATION
ROUGHLY NOW JUST EAST OF THE I-5 CORRIDOR THROUGH SOUTHERN OREGON
AND SISKIYOU COUNTY. PRECIPITATION HAS BEEN WIDESPREAD ON THE WEST
SIDE WITH AMOUNTS IN THE LAST 3 HOURS LARGELY BELOW 0.10 INCHES.
MEANTIME...SHOWERS IN KLAMATH AND EASTERN SISKIYOU COUNTY HAVE
BEEN ISOLATED TO SCATTERED AND WILL BE GREATEST IN NUMBER DURING
THE NEXT 3 HOURS. THE SNOW LEVEL IS AROUND 4500 FEET AND SNOW
AMOUNTS OVER THE CASCADES AND EAST SIDE ARE EXPECTED TO BE NOT
MUCH MORE THAN A DUSTING...UP TO A HALF OF AN INCH. SHOWERS AND
SNOW SHOWERS WILL TAPER OFF OVERNIGHT INTO THURSDAY MORNING.
THE 00Z GFS HAS ARRIVED AND INDICATES LIGHT RAIN TO ARRIVE AT THE
COOS COUNTY COAST DURING THURSDAY AFTERNOON...IN ADVANCE OF THE
NEXT FRONT. OTHERWISE, THERE WILL BE A MIX OF CLOUDS ACROSS THE
AREA INCLUDING MORNING VALLEY LOW CLOUDS AND PATCHY FOG. FRONTAL
PRECIPITATION WILL BE FOCUSED ON THE THURSDAY NIGHT PERIOD WITH
MODERATE TO HEAVY PRECIPITATION FOR THE CURRY COUNTY AND NORTHERN
CALIFORNIA COAST INTO JOSEPHINE AND SISKIYOU COUNTIES. THE SNOW
LEVEL IS FORECAST TO BEGIN THE EVENING AT AROUND 6000 TO 6500 FEET
THEN FALL TO AROUND 4000 TO 5000 FEET AS PRECIPITATION AMOUNTS
DIMINISH AND PRECIPITATION TRANSITIONS TO SHOWERS ON FRIDAY
MORNING...DIMINISHING DURING THE DAY. THUS, THE SNOW LEVEL WILL BE
ABOVE THE MAJOR PASSES DURING THE MAJORITY OF THE EVENT.
A STRONG WARM FRONT IS STILL INDICATED TO ARRIVE SATURDAY WITH
WIDESPREAD PRECIPITATION AT LEAST THROUGH SATURDAY EVENING BUT
ALSO RISING SNOW LEVELS THAT WILL BE WELL ABOVE THE PASSES.
THIS FRONT WILL LINGER THROUGH THE WEEKEND WITH MODERATE TO HEAVY
PRECIPITATION LATE SATURDAY NIGHT INTO MONDAY MAINLY FROM ROSEBURG
NORTHWARD.
&&
.AVIATION...BASED ON THE 18/00Z TAF CYCLE...VFR CONDITIONS WILL
PREVAIL INITIALLY WITH AREAS OF HIGHER TERRAIN OBSCURED...EXCEPT FOR
WESTERN AND SOUTH CENTRAL SISKIYOU COUNTY...WHERE AREAS OF MVFR CIGS
WILL PREVAIL THROUGH THURSDAY MORNING. WIDESPREAD MVFR CIGS WILL
RETURN TO THE WEST SIDE VALLEYS OVERNIGHT...AND WITH INCREASING
WINDS AND THE MVFR DECKS FOG FORMATION SHOULD BE LIMITED. ALL AREAS
WILL CLEAR TO VFR BY THURSDAY AFTERNOON. /SVEN
&&
.MARINE...UPDATED 645 PM PST WED DEC 17 2014...WEAK LOW PRESSURE
SYSTEMS WILL MOVE THROUGH THE AREA TONIGHT. SOUTHWEST SWELL
DOMINATED SEAS WILL REMAIN MOSTLY AT OR ABOVE 10 FEET TODAY.
THURSDAY INTO THURSDAY NIGHT A STRONGER FRONTAL SYSTEM WILL LIKELY
BRING GALE FORCE WINDS AND VERY STEEP SOUTHWEST SEAS. LONG PERIOD
WEST SWELL WILL BEGIN TO ARRIVE IN THE PREDAWN HOURS FRIDAY MORNING.
IT WILL PEAK FRIDAY NIGHT AT AROUND 20 FEET AT 20 SECONDS. SERIES OF
LARGE LONG PERIOD SWELL CONTINUE TO MOVE INTO THE REGION THROUGH
EARLY NEXT WEEK. A WARM FRONT WILL MOVE THROUGH FRIDAY
NIGHT...FOLLOWED BY A COLD FRONT SATURDAY. OFFSHORE HIGH PRESSURE
WILL BUILD SATURDAY NIGHT INTO SUNDAY. /SVEN
&&
.PREV DISCUSSION... /ISSUED 206 PM PST WED DEC 17 2014/
DISCUSSION...ANOTHER WEAK UPPER TROUGH IS NEAR THE COAST AND THIS
WILL MOVE INLAND THIS EVENING. CURRENT RADAR SHOWS TWO AREAS OF
SCATTERED SHOWERS. THE FIRST IS IN NORTHEAST SISKIYOU AND KLAMATH
COUNTY AND THE SECOND IS MOVING TOWARDS THE COAST. THIS SECOND
FEATURE WILL MOVE INLAND THIS EVENING AND BRING SCATTERED SHOWERS
OVER NORTHERN CAL AND SOUTHWEST OREGON. THE LATEST RAP MODELS
DEPICTS THE PLACEMENT OF THE PRECIPITATION WELL AND WILL FOLLOW THIS
FOR THIS EVENING. THE UPPER TROUGH WILL WEAKEN AS IT MOVES EAST AND
SHORTWAVE RIDGING BEGINS TO BUILD IN OVERNIGHT. THIS SHOULD SHUT OFF
THE SHOWER ACTIVITY OVER MOST OF THE AREA, ALTHOUGH SOME RESIDUAL
SHOWERS COULD LINGER IN SOUTHEAST SISKIYOU AND MODOC COUNTIES.
WE`LL CATCH A DRY BREAK ON THURSDAY WITH THE RIDGE AXIS OVER THE
AREA, BUT THIS WILL BE SHORT LIVED. THE MODELS SHOW A STRONGER FRONT
APPROACHING THE AREA THURSDAY AFTERNOON BRINGING INCREASING SOUTH
WINDS OVER THE MARINE WATERS WHICH ARE EXPECTED TO GET CLOSE TO
GALES. PRECIPITATION COULD ALSO REACH THE COAST AS EARLY AS THURSDAY
AFTERNOON. THE FRONT WILL MOVE INLAND THURSDAY NIGHT BRINGING
MODERATE TO HEAVY PRECIPITATION OVER THE USUAL SUSPECTS...THE COAST
RANGE...COASTAL MOUNTAINS AND CASCADES. HOWEVER THE MODELS ARE IN
GOOD AGREEMENT THE FRONT WILL BE A QUICK MOVER AND SO WE WON`T GET
SIGNIFICANT PRECIPITATION AMOUNTS. SNOW LEVELS WILL START OUT HIGH
THURSDAY NIGHT, BUT WILL DROP TO AROUND 4500 FEET EARLY FRIDAY
MORNING. SO IT`S A GOOD BET THE MOUNTAIN PASSES WILL GET
ACCUMULATING SNOW STARTING LATE THURSDAY NIGHT THROUGH FRIDAY
MORNING. CURRENT THINKING IS CRATER LAKE COULD PICK UP AT LEAST 6
INCHES OR MORE AND A FEW INCHES ARE POSSIBLE OVER SISKIYOU SUMMIT
AND HIGHWAY 140. KEEP IN MIND THE DETAILS ON THIS WILL CHANGE, SO
STAY TUNED FOR THE LATEST UPDATES.
THE ABOVE MENTIONED FRONT WILL QUICKLY MOVE THROUGH FRIDAY AND WE`LL
CATCH A RELATIVE BREAK IN PRECIPITATION FRIDAY AFTERNOON AND EVENING.
BUT AGAIN THIS WILL BE SHORT LIVED. THE MODELS ARE IN PRETTY GOOD
AGREEMENT SHOWING A STRONG WARM FRONT ARRIVING AT THE COAST LATE
FRIDAY NIGHT AND MOVING OVER THE AREA SATURDAY. THIS FRONT HAS A LOT
OF JUICE WITH IT AND HEAVY PRECIPITATION WILL LIKELY IMPACT THE
COAST...COAST RANGE...COASTAL MOUNTAINS AND CASCADES. MODERATE TO
HEAVY PRECIPITATION WILL ALSO IMPACT MUCH OF THE WESTSIDE VALLEYS. OF
NOTE THE IVT TRANSPORT (WHICH IS GFS BASED) PUTS THE HIGHEST VALUES
IN CENTRAL AND NORTHWEST OREGON. EVEN THE GEFS ENSEMBLE MEAN IS
SIMILAR TO THE OPERATIONAL GFS. ADDITIONALY, THE UPPER FLOW IS
ALMOST DUE WEST WHICH WILL SQUEEZE OUT EVEN MORE MOISTURE ALONG THE
COAST RANGE. ALSO WINDS WILL INCREASE AHEAD OF THE FRONT AND THERE
IS A CHANCE FOR GALE FORCE WINDS OVER THE MARINE WATERS AND MODERATE
TO STRONG WINDS OVER THE COAST AND HEADLANDS. IF THAT WEREN`T ENOUGH
THERE IS CONCERN FOR SNOW EAST OF THE CASCADES AS THE WARM FRONT
ARRIVES. MODEL SOUNDINGS SUPPORT THE IDEA THAT ENOUGH COLD AIR WILL
BE PRESENT NEAR THE SURFACE AND THIS IN COMBINATION WITH OVERRUNNING
PRECIPITATION COULD BRING A PERIOD OF SNOW SATURDAY MORNING.
STRONG WESTERLY FLOW CONTINUES SATURDAY NIGHT WITH THE HEAVIEST
PRECIPITATION WEST OF THE CASCADES, BUT SNOW LEVELS WILL JUMP UP TO
AROUND 7000 FEET SATURDAY AFTERNOON AND REMAIN HIGH SATURDAY NIGHT.
-PETRUCELLI
LONG-TERM FORECAST...SUNDAY THROUGH WEDNESDAY. A BROAD LONG WAVE
RIDGE WILL BE IN PLACE AT THE BEGINNING OF THE EXTENDED PERIOD WITH
WITH GENERALLY NORTHWEST FLOW ALOFT. SHORT WAVES RIDING OVER THE TOP
OF THE RIDGE WILL WEAKEN IT FROM SUNDAY NIGHT ON...BUT IT WILL
REMAIN IN PLACE THROUGH TUESDAY. THE FLOW ALOFT WILL BECOME MORE
ZONAL TUESDAY.
THIS PATTERN WILL FORCE THE MAIN STORM TRACK TO THE NORTH OF THE
MEDFORD CWA...BUT THE AREA WILL STILL CATCH THE SOUTHERN END OF
SEVERAL SYSTEMS WHICH WILL MOVE ONSHORE DURING THIS INTERVAL. THE
STRONGEST OF THESE SYSTEMS WILL MOVE ONSHORE SATURDAY AFTERNOON AND
EVENING...AND WILL BE OVER THE CWA SUNDAY. REINFORCING SHORT WAVES
WILL KEEP THE PRECIPITATION GOING THROUGH MOST OF MONDAY. THE BULK
OF THE ASSOCIATED PRECIPITATION WILL FALL ALONG THE COAST...COAST
RANGE...AND UMPQUA BASIN. AMOUNTS WILL BE SIGNIFICANT BUT NOT
EXCESSIVE...NO FLOODING PROBLEMS ARE ANTICIPATED. SNOW LEVELS WILL
BE ABOVE 7000 FEET.
MONDAY NIGHT INTO TUESDAY LOOK TO BE MOSTLY DRY WITH NEARLY ALL THE
ACTION TO THE NORTH OF THE AREA.
THE RIDGE WILL BREAK DOWN WEDNESDAY AND A LONG WAVE TROUGH WILL
BEGIN TO DIG OFFSHORE. THIS CHANGE IN PATTERN WILL SUPPORT A FRONT
MOVING ONSHORE WEDNESDAY. THIS WILL BE THE WETTEST SYSTEM OF THE
EXTENDED PERIOD IF THE CURRENT EC/GFS MODEL SOLUTIONS PAN OUT. SNOW
LEVELS MAY ALSO FALL AS LOW AS 4000 FEET BEHIND THE FRONT WEDNESDAY
NIGHT...SO SNOW MAY RETURN TO THE PASSES AROUND THAT TIME. -JRS
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS FROM 4 AM
TO 10 PM PST THURSDAY FOR PZZ350-356-370-376.
HAZARDOUS SEAS WARNING FROM 11 AM THURSDAY TO 4 AM PST
FRIDAY FOR PZZ350-356-370-376.
GALE WARNING FROM 10 AM TO 10 PM PST THURSDAY FOR
PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 4 AM TO
10 AM PST THURSDAY FOR PZZ350-356-370-376.
$$
DW/DW/SBN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1158 PM EST WED DEC 17 2014
.SYNOPSIS...
BRISK WESTERLY WINDS WILL USHER IN COLDER AIR ALONG WITH SCATTERED
MAINLY MOUNTAIN SNOW SHOWERS THROUGH THE END OF THE WEEK. A WEAK
LOW PRESSURE AREA IS EXPECTED TO MOVE WELL SOUTH OF THE REGION
THIS WEEKEND. THERE ARE INDICATIONS THAT THE WEATHER PATTERN COULD
TURN MORE UNSETTLED FOR NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
NO REAL CHANGES MADE WITH THIS UPDATE OTHER THAN SOME MINOR
TEMPERATURE TWEAKS.
BEST CHANCE OF SOW SHOWERS WILL BE OVER THE MORE TRADITIONAL HIGH
TERRAIN AREAS OF THE WEST AND NORTH AS WE ESTABLISH A COLD WNW
FLOW OVER THE REGION. HRRR SHOWS PRECIP REMAINING CONFINED TO
MAINLY NWRN PA THROUGH THE OVERNIGHT AND LATEST OPERATIONAL
GUIDANCE SUPPORTS THIS.
WEST TO NW WINDS WILL AVERAGE 10-15 KTS WITH GUSTS IN THE 20S
LATE TODAY THROUGH TONIGHT.
LOW TEMPS AT DAYBREAK THURS WILL BE NEAR 20F ACROSS THE HIGHER
TERRAIN OF THE NORTH AND WEST...AND IN THE MID TO UPPER 20S
THROUGHOUT THE SUSQ VALLEY.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
COLD AIR WILL STAY IN PLACE ACROSS THE FCST AREA THURSDAY INTO
FRIDAY.
THURSDAY...WINDS AT THE SFC AND ALOFT WILL VEER JUST SLIGHTLY TO
THE NORTHWEST. SPEEDS OF 10-15 MPH AND GUSTS INTO THE L20S ARE
POSSIBLE OVER THE MOUNTAINS. LITTLE OF NO CHANGE IN THE BLANKET OF
STRATUS AND STRATOCU CLOUDS IS EXPECTED THURSDAY AND THU
NIGHT...AND THE RELATIVELY SHALLOW COLD AIR BLOWING OVER THE LOWER
GLAKES WILL CREATE MORE SHSN ACROSS THE NRN AND WRN MTNS.
ACCUMULATIONS WILL BE MINOR...AND CONFINED TO THE FAR NW AND VERY
HIGHEST ELEVATIONS. AS STATED BY PREVIOUS SHIFTS NO MORE THAN 2
INCHES IS EXPECTED THROUGHOUT THE SNOWBELT OF NW WARREN COUNTY ON
THE HIGH END...SO NO LES ADVISORIES PLANNED ATTM. GLIMPSES OF
SUN MAY DEVELOP AGAIN ACROSS THE LOWER SUSQ...NUDGING TEMPS INTO
THE LOWER 40S /NEAR NORMAL FOR MID DEC/. MAX TEMPS ACROSS THE NRN
AND WRN MTNS WILL BE IN THE U20S TO L30S.
SIMILAR TEMPS AND SKY COVER EXPECTED AGAIN FOR THU NIGHT WITH
ISOLATED TO SCTD MTN SNOW SHOWERS. LITTLE IN THE WAY OF
ADDITIONAL SNOW ACCUM IS EXPECTED THOUGH AS MOISTURE WILL
CONTINUE TO BE QUITE SHALLOW WITH THE SUBSIDENCE INVERSION BASE
AOB 5 KFT AGL. A FEW HIGHLY LOCALIZED AMOUNTS IN THE 2-3 INCH
RANGE ARE POSSIBLE ACROSS THE FAVORED PERENNIAL SNOWBELT OF WARREN
COUNTY DURING THE 24 HOUR PERIOD ENDING 12Z FRI.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE PATTERN WILL REMAIN SEASONABLY COLD AND BRISK THROUGH THE END
OF THE WEEK. LARGE SCALE SUBSIDENCE ASSOCIATED WITH SURFACE HIGH
MIGRATING EASTWARD FROM THE UPPER MIDWEST ACROSS ONTARIO/QUEBEC
SHOULD BRING AN END TO NUISANCE/MINOR SNOW SHOWER ACTIVITY AND
LINGERING FLURRIES OVER THE NW ALLEGHENIES BY FRI NGT. CLEAR SKIES
AND CALM/LIGHT WINDS SHOULD ALLOW MIN TEMPS TO DIP INTO THE TEENS
IN THE NORTHERN MTNS SATURDAY MORNING.
CONCERNING THE WEEKEND SYSTEM...
HOPES FOR A SIGNIFICANT STORM THIS WEEKEND CONTINUE TO FADE WITH
THE LATEST MODELS CONTINUING TO SHOW A MUCH WEAKER/SUPPRESSED AND
DISJOINTED SYSTEM AS THE CONSENSUS SOLUTION. IN ADDITION..THE
RISK FOR ACCUMULATING LIGHT SNOW HAS ALSO NOTABLY DECREASED...BUT
NOT TOTALLY EVAPORATED. THAT SAID THERE IS STILL A NON-TRIVIAL
CHANCE THAT MOST PRECIP REMAINS SOUTH OF PA AND THE WEEKEND TURNS
OUT DRY FOR MOST LOCATIONS. EARLY WEEK MODEL SIMULATIONS FOR A
MAJOR STORM HAVE ALL BUT TRENDED TO A VIRTUAL NON EVENT FOR OUR
AREA.
THE PROGRESSIVE SPLIT STREAM ENERGY ALOFT MOVING EAST FROM THE
MID MS VLY NEVER REALLY ORGANIZES AS IT ATTEMPTS TO OVERRUN A
RETREATING AREA OF MODESTLY STRONG HP/RIDGING OVER THE NORTHEAST
AND EASTERN CANADA. AS SUCH DOWNPLAYED PCPN POTENTIAL AND TRIMMED
POPS BACK BY 10-20 PCT. THE NEW WRINKLE IN THIS FORECAST CYCLE IS
FOR A SECOND PIECE OF ENERGY /WHAT APPEARS TO BE THE MAIN SFC LOW/
LIFTING NORTH FROM NEAR THE FL/GA COAST AND TRACKING UP/OFFSHORE
THE EAST COAST SUN THRU TUE.
THE SPLIT FLOW PATTERN OVER THE CONUS IS EXPECTED TO BECOME HIGHLY
AMPLIFIED WITH A VERY DEEP NEGATIVELY TILTED TROUGH EVOLVING EAST
OF THE ROCKIES...LIKELY SPAWNING AN INTENSE SFC LOW OVER THE
GREAT LAKES/MID ATLANTIC/NORTHEAST REGIONS AROUND THE CHRISTMAS
EVE TIME FRAME. FOR WHAT ITS WORTH...BOTH THE 17/12Z GFS AND EC
ARE FORECASTING A RECORD LOW MSLP SUB 970MB CYCLONE INVOF LAKE
HURON AT 00Z ON 25 DEC. THIS SYSTEM WILL LIKELY GATHER MORE AND
MORE ATTENTION AS WE MOVE CLOSER TO THE HOLIDAY. THE GOOD NEWS FOR
TRAVELERS/BAD NEWS FOR SNOW CROWS IS THAT CURRENT PROJECTIONS
WOULD PLACE CENTRAL PA INITIALLY IN THE "WARM" SIDE OF THE DEEP
STORM FAVORING RAIN VS. SNOW. IT ALSO LOOKS QUITE WINDY ASSUMING
THE DEEP LOW VERIFIES.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
WIDESPREAD STRATO CU AND PERSISTENT MVFR TO IFR CIGS WITH
ISOLATED-SCATTERED AND GENERALLY BRIEF MVFR TO IFR VSBYS IN SNOW
SHOWERS WILL OCCUR ACROSS THE NW MTNS AND LAUREL HIGHLANDS /INVOF
KBFD AND KJST/ TONIGHT INTO THE MORNING HOURS. CONDITIONS ACROSS
THE CENTRAL MTNS WILL VARY BETWEEN LOW END VFR...AND MVFR CIGS.
GUSTY WEST TO WNW WINDS /UP AROUND 25 KTS AT TIMES/ WILL ADD SOME
MECHANICAL TURBULENCE DURING TAKEOFF AND FAP TO REGIONAL AIRFIELDS
THIS EVENING THROUGH THURSDAY. VFR CIGS AND VSBYS SHOULD CONTINUE
OVERNIGHT THROUGH THE EASTERN TAF SITES.
OUTLOOK...
THU-FRI...MVFR CIGS POSS NW. OTHERWISE NO SIG WX EXPECTED.
SAT-SUN...LIGHT SNOW/REDUCED VSBY POSSIBLE ...MAINLY ALONG THE MD
BORDER.
MONDAY...MAINLY VFR. HOWEVER...AREAS OF MVFR STRATO CU ARE
POSSIBLE IN DEVELOPING SERLY LOW LEVEL FLOW.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LAMBERT
LONG TERM...STEINBUGL
AVIATION...LAMBERT/CERU
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
312 PM EST THU DEC 18 2014
.SHORT TERM...RADAR SHOWS SOME PATCHY LIGHT RAIN OR DRIZZLE WILL
BE MOVING ACROSS THE AREA FOR THE NEXT FEW HOURS...BUT THIS SHOULD
EXIT BY 00Z AND WILL CARRY NO POPS AFTER THAT TIME. THE QUESTION
OVERNIGHT WILL BE WHETHER CLOUDS ARE ABLE TO ERODE AS MUCH AS THE
GFS SAYS THEY WILL...OR IF THEY WILL HANG IN THROUGH MOST OF THE
NIGHT AS SHOWN BY THE NAM. WILL LEAN TOWARD THE NAM AS UPSTREAM
SATELLITE DOES NOT LOOK PROMISING FOR CLEARING ANY TIME SOON...AND
THE RAP LOOKS CLOSER TO THE NAM. WILL ALSO LEAN TEMPS ON THE WARM
SIDE OF MOS TONIGHT. THERE SHOULD BE SOME SUN ACROSS MOST OF THE
AREA BY MORNING...THEN HIGH CLOUDS BEGIN TO INCREASE FROM THE SW
AHEAD OF SOUTHERN STREAM VORT MAX AND JET STREAK. HIGH TEMPS SHOULD
REACH A CATEGORY OR TWO HIGHER THAN TODAY. ANY PRECIP WITH THIS
SYSTEM SHOULD HOLD OFF UNTIL AFTER THE END OF THE SHORT TERM
PERIOD.
.LONG TERM (FRIDAY NIGHT THROUGH THURSDAY)...A FAST MOVING SYSTEM
THAT IS FORECAST TO FORM ALONG THE GULF COAST FRIDAY WILL MOVE FROM
THE LOWER MS VALLEY INTO THE EASTERN TENNESSEE VALLEY OVERNIGHT
FRIDAY NIGHT INTO SATURDAY MORNING. THE BULK OF THE SYSTEM WILL BE
SOUTH OF TN AND AFFECT THE SOUTHEASTERN STATES INTO THE CAROLINAS.
TEMPERATURES WILL DROP INTO THE 30S FRIDAY EVENING AND AREAS TO THE
NORTH OF INTERSTATE 40...ESPECIALLY IN THE HIGHER ELEVATIONS COULD
SEE SOME SNOW LATE FRIDAY NIGHT AND EARLY SATURDAY. LOWS WILL ONLY
DROP TO NEAR FREEZING SO AMOUNTS ARE EXPECTED TO BE LIGHT...LESS
THAN ONE INCH. TEMPERATURES SATURDAY WILL WARM ABOVE FREEZING TO
THE 40S TO NEAR 50. WEAK HIGH PRESSURE BUILDS BACK IN SATURDAY
NIGHT AND SUNDAY WITH SKIES BECOMING PARTLY SUNNY.
SUNDAY NIGHT THROUGH LATE TUESDAY PATTERN CONTINUES TO BE UNSETTLED.
UPPER TROUGH OVER THE CENTRAL STATES WILL HELP ANOTHER SYSTEM
DEVELOP OVER THE NORTHERN PLAINS AND A NEW SYSTEM ALSO DEVELOPS
ALONG THE GULF COAST. THE SOUTHERN SYSTEM WILL AFFECT THE FORECAST
AREA FIRST WITH A CHANCE OF RAIN SUNDAY NIGHT AND MONDAY. THIS
SYSTEM PULLS OUT AND THEN THE STRONGER SECOND SYSTEM WILL MOVE
INTO THE OHIO AND TN VALLEYS MONDAY NIGHT AND TUESDAY. THIS SYSTEM
IS EXPECTED TO FORM AN UPPER LOW OVER THE MID MS VALLEY TUESDAY AND
THEN SLOWLY MOVE EAST INTO THE EASTERN GREAT LAKE STATES THROUGH
WEDNESDAY. COLDER AIR ON THE BACK SIDE OF THE SYSTEM WILL LOWER
TEMPERATURES WEDNESDAY AND THURSDAY. ALSO THE SYSTEM IS EXPECTED TO
DEEPEN MORE. SNOW SHOWERS WILL LIKELY AFFECT THE NORTHERN PARTS OF
THE AREA WEDNESDAY AND WEDNESDAY NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 33 49 37 50 / 0 10 70 70
KNOXVILLE MCGHEE TYSON AIRPORT, TN 29 47 34 46 / 10 0 50 50
OAK RIDGE, TN 30 47 34 46 / 0 0 50 40
TRI CITIES AIRPORT, TN 28 46 30 43 / 10 0 30 50
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS/TD
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
815 PM CST FRI DEC 19 2014
.UPDATE...
LIGHT NORTHEAST WINDS WILL OCCASIONALLY BECOME LIGHT AND VARIABLE
AS NORTH TEXAS REMAINS SITUATED ON THE SOUTHWEST FLANK OF A
SURFACE RIDGE AXIS. WE ARE BEGINNING TO SEE A FEW LOWERING
VISIBILITIES ACROSS THE REGION THIS EVENING...SO WE WILL ADD SOME
PATCHY FOG TO THE GRIDS FOR THE OVERNIGHT AND EARLY SATURDAY
TIME FRAME. OTHERWISE CLOUDY AND COOL CONDITIONS ARE EXPECTED WITH
LOWS IN THE UPPER 30S ACROSS THE NORTHWESTERN THIRD OF THE
REGION...AND LOWER TO MIDDLE 40S ELSEWHERE.
30
&&
.AVIATION...
/ISSUED 623 PM CST FRI DEC 19 2014/
/00Z TAFS/
A SHORTWAVE DISTURBANCE ALOFT WILL CONTINUE EXITING THE REGION
THIS EVENING. MEANWHILE AT THE SURFACE...NORTH AND CENTRAL TEXAS
REMAINED ENTRENCHED WITHIN A BROAD SURFACE RIDGE WITH NORTH WINDS
5-10 KTS. IFR AND MVFR REMAIN SOCKED INTO THE AREA WITH PATCHY
LIGHT FOG AND DRIZZLE. CHALLENGES THIS FORECAST WILL BE TRENDS
WITH CIGS AND VSBYS. MODEL BUFR SOUNDINGS AND MOS GUIDANCE ARE ALL
SHOWING DIFFERENT SCENARIOS...WITH THE THE NAM AND RUC THE MOST
PESSIMISTIC.
DUE TO OUR CURRENT SYNOPTIC SET UP WITHIN THE LOW LEVELS...THE
PESSIMISTIC APPROACH APPEARS TO BE THE MOST LIKELY SCENARIO. DFW
AREA AIRPORTS WILL START OFF MVFR THIS EVENING THEN BECOME IFR
OVERNIGHT WITH MVFR VSBYS. IF WINDS GO CALM WE COULD SEE VSBYS
DROP INTO THE IFR CATEGORY AS WELL. WACO WILL LIKELY SEE IFR CIGS
THIS EVENING WITH THE POTENTIAL TO BECOME LIFR OVERNIGHT AS WINDS
DROP OFF.
IMPROVEMENT ON SATURDAY WILL BE SLOW AS WE APPROACH THE SHORTEST
DAY OF THE YEAR. IFR CONDITIONS SATURDAY MORNING WILL SLOWLY IMPROVE
TO MVFR BY SATURDAY AFTERNOON WITH VISIBILITY IMPROVING TO VFR.
ESE FLOW LIKELY TO RETURN SATURDAY AFTERNOON AS WELL.
05/
&&
.PREV DISCUSSION... /ISSUED 305 PM CST FRI DEC 19 2014/
JUST A FEW SPRINKLES THIS AFTERNOON ALONG THE RED RIVER AS THE
UPPER TROF CONTINUES TO PUSH EASTWARD ACROSS THE STATE. LOW CLOUDS
BLANKET NORTH TEXAS AND WITH LIGHT NORTHEAST WINDS AND A STRONG
LOW-LEVEL INVERSION...EXPECT CLOUDS TO REMAIN IN PLACE OVERNIGHT
AND THROUGH MOST OF THE DAY TOMORROW THOUGH A BIT OF SUNSHINE WILL
BE POSSIBLE BY AFTERNOON ESPECIALLY OVER THE WESTERN ZONES.
TEMPERATURES TONIGHT WILL NOT DROP MUCH FROM WHERE WE ARE RIGHT
NOW DUE TO THE CLOUD COVER AND WILL BE SLOW TO REBOUND ON
SATURDAY. ANOTHER SHORTWAVE WILL APPROACH THE AREA SATURDAY NIGHT AND
SUNDAY BUT WILL NOT HAVE ANY SENSIBLE IMPACTS ON THE WEATHER
ACROSS NORTH TEXAS. SUNDAY WILL BE A BIT WARMER THAN SATURDAY AS
SOUTHERLY WINDS RETURN ACROSS THE AREA.
NEXT FRONT WILL PUSH THROUGH NORTH TEXAS LATE MONDAY INTO TUESDAY
MORNING. MOISTURE RETURN WILL BE QUITE LIMITED WITH THIS SYSTEM
AND AS A RESULT JUST HAVE SLIGHT CHANCE OF POPS OVER THE EASTERN
ZONES. ANY RAINFALL THAT OCCURS WILL BE QUITE LIGHT.
COOLER WEATHER IN STORE FOR TUESDAY AND WEDNESDAY BEHIND THE FRONT
BUT THE BRUNT OF THE COLDEST AIR WILL STAY WELL TO OUR EAST AND A
RESULT...TEMPS WILL BE CLOSE TO CLIMO. A VERY MILD CHRISTMAS IS IN
STORE AS LOW-LEVEL WINDS BECOME SOUTHWESTERLY ON CHRISTMAS DAY
USHERING IN WARMER AIR.
WILEY
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 40 52 41 55 45 / 5 5 5 10 10
WACO, TX 42 53 40 56 44 / 5 5 5 10 5
PARIS, TX 39 49 38 52 42 / 10 5 5 10 10
DENTON, TX 39 51 39 54 43 / 5 5 5 10 10
MCKINNEY, TX 40 50 38 53 43 / 10 5 5 10 10
DALLAS, TX 40 52 41 55 45 / 5 5 5 10 10
TERRELL, TX 41 51 40 54 44 / 10 5 5 10 10
CORSICANA, TX 43 54 41 55 45 / 10 5 5 10 10
TEMPLE, TX 43 54 41 56 44 / 5 5 5 10 10
MINERAL WELLS, TX 39 51 38 55 42 / 5 5 5 10 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/30
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
623 PM CST FRI DEC 19 2014
.AVIATION...
/00Z TAFS/
A SHORTWAVE DISTURBANCE ALOFT WILL CONTINUE EXITING THE REGION
THIS EVENING. MEANWHILE AT THE SURFACE...NORTH AND CENTRAL TEXAS
REMAINED ENTRENCHED WITHIN A BROAD SURFACE RIDGE WITH NORTH WINDS
5-10 KTS. IFR AND MVFR REMAIN SOCKED INTO THE AREA WITH PATCHY
LIGHT FOG AND DRIZZLE. CHALLENGES THIS FORECAST WILL BE TRENDS
WITH CIGS AND VSBYS. MODEL BUFR SOUNDINGS AND MOS GUIDANCE ARE ALL
SHOWING DIFFERENT SCENARIOS...WITH THE THE NAM AND RUC THE MOST
PESSIMISTIC.
DUE TO OUR CURRENT SYNOPTIC SET UP WITHIN THE LOW LEVELS...THE
PESSIMISTIC APPROACH APPEARS TO BE THE MOST LIKELY SCENARIO. DFW
AREA AIRPORTS WILL START OFF MVFR THIS EVENING THEN BECOME IFR
OVERNIGHT WITH MVFR VSBYS. IF WINDS GO CALM WE COULD SEE VSBYS
DROP INTO THE IFR CATEGORY AS WELL. WACO WILL LIKELY SEE IFR CIGS
THIS EVENING WITH THE POTENTIAL TO BECOME LIFR OVERNIGHT AS WINDS
DROP OFF.
IMPROVEMENT ON SATURDAY WILL BE SLOW AS WE APPROACH THE SHORTEST
DAY OF THE YEAR. IFR CONDITIONS SATURDAY MORNING WILL SLOWLY IMPROVE
TO MVFR BY SATURDAY AFTERNOON WITH VISIBILITY IMPROVING TO VFR.
ESE FLOW LIKELY TO RETURN SATURDAY AFTERNOON AS WELL.
05/
&&
.PREV DISCUSSION... /ISSUED 305 PM CST FRI DEC 19 2014/
JUST A FEW SPRINKLES THIS AFTERNOON ALONG THE RED RIVER AS THE
UPPER TROF CONTINUES TO PUSH EASTWARD ACROSS THE STATE. LOW CLOUDS
BLANKET NORTH TEXAS AND WITH LIGHT NORTHEAST WINDS AND A STRONG
LOW-LEVEL INVERSION...EXPECT CLOUDS TO REMAIN IN PLACE OVERNIGHT
AND THROUGH MOST OF THE DAY TOMORROW THOUGH A BIT OF SUNSHINE WILL
BE POSSIBLE BY AFTERNOON ESPECIALLY OVER THE WESTERN ZONES.
TEMPERATURES TONIGHT WILL NOT DROP MUCH FROM WHERE WE ARE RIGHT
NOW DUE TO THE CLOUD COVER AND WILL BE SLOW TO REBOUND ON
SATURDAY. ANOTHER SHORTWAVE WILL APPROACH THE AREA SATURDAY NIGHT AND
SUNDAY BUT WILL NOT HAVE ANY SENSIBLE IMPACTS ON THE WEATHER
ACROSS NORTH TEXAS. SUNDAY WILL BE A BIT WARMER THAN SATURDAY AS
SOUTHERLY WINDS RETURN ACROSS THE AREA.
NEXT FRONT WILL PUSH THROUGH NORTH TEXAS LATE MONDAY INTO TUESDAY
MORNING. MOISTURE RETURN WILL BE QUITE LIMITED WITH THIS SYSTEM
AND AS A RESULT JUST HAVE SLIGHT CHANCE OF POPS OVER THE EASTERN
ZONES. ANY RAINFALL THAT OCCURS WILL BE QUITE LIGHT.
COOLER WEATHER IN STORE FOR TUESDAY AND WEDNESDAY BEHIND THE FRONT
BUT THE BRUNT OF THE COLDEST AIR WILL STAY WELL TO OUR EAST AND A
RESULT...TEMPS WILL BE CLOSE TO CLIMO. A VERY MILD CHRISTMAS IS IN
STORE AS LOW-LEVEL WINDS BECOME SOUTHWESTERLY ON CHRISTMAS DAY
USHERING IN WARMER AIR.
WILEY
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 40 52 41 55 45 / 5 5 5 10 10
WACO, TX 42 53 40 56 44 / 5 5 5 10 5
PARIS, TX 39 49 38 52 42 / 10 5 5 10 10
DENTON, TX 39 51 39 54 43 / 5 5 5 10 10
MCKINNEY, TX 40 50 38 53 43 / 10 5 5 10 10
DALLAS, TX 40 52 41 55 45 / 5 5 5 10 10
TERRELL, TX 41 51 40 54 44 / 10 5 5 10 10
CORSICANA, TX 43 54 41 55 45 / 10 5 5 10 10
TEMPLE, TX 43 54 41 56 44 / 5 5 5 10 10
MINERAL WELLS, TX 39 51 38 55 42 / 5 5 5 10 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/81
AREA FORECAST DISCUSSION
NWS AMARILLO TX
248 PM CST THU DEC 18 2014
.DISCUSSION...
PRIMARY WEATHER IMPACTS DURING THE NEXT SEVEN DAYS WILL BE IN THE
SHORT TERM WITH PRECIPITATION CHANCES TONIGHT AND POTENTIAL FOR FOG
ONCE AGAIN. MAIN ADJUSTMENT TO THE FORECAST WAS TO TRY AND BE MORE
DETERMINISTIC WITH PRECIPITATION TYPE OVERNIGHT ALTHOUGH THAT
REMAINS A CHALLENGE GIVEN MARGINAL THERMAL PROFILES FOR FROZEN
PRECIPITATION IN MODEL FORECAST SOUNDINGS. INITIAL CONCERNS ARE FOG
POTENTIAL LATER TONIGHT AS LOW LEVEL FLOW BECOMES MORE EASTERLY AND
STRENGTHENS. MOISTURE OVER SOUTHWEST OKLAHOMA AND WESTERN NORTH
TEXAS WILL ADVECT WESTWARD AND UPSLOPE. HAVE INCLUDED AREAS OF FOG
IN THE GRIDS. LOCALLY DENSE FOG WILL AGAIN BE POSSIBLE.
WV LOOP AND 500 MB RAP ANALYSIS CLEARLY SHOWED A SHORTWAVE TROUGH
OVER EASTERN ARIZONA MOVING EASTWARD. SHORT TERM MODELS ARE IN GOOD
AGREEMENT ON THE TIMING AND STRENGTH OF THIS WAVE AS IT MOVES TOWARD
WEST TEXAS TONIGHT AND CROSSES THE REGION TOMORROW MORNING. THE
PERIOD OF BEST OMEGA/SATURATION IN THE DEDRITIC GROWTH ZONE WILL BE
AFTER ABOUT 03Z IN THE WEST SPREADING EASTWARD OVERNIGHT AND LASTING
THROUGH ABOUT 15Z IN THE EAST. JUST BELOW THE DGZ IS A LAYER OF DRY
AIR THAT WILL TAKE SOME TIME TO SATURATE THUS DELAYING THE ONSET OF
PRECIPITATION UNTIL CLOSER TO MIDNIGHT IN THE WEST/CENTRAL AND AFTER
MIDNIGHT IN THE EAST. THE BIGGEST CHALLENGE FOR CONVEYING SENSIBLE
WEATHER IN THIS FORECAST WILL BE THE TEMPERATURE PROFILE. AT LEAST
SHORT RANGE MODELS AGREES FAIRLY WELL. THE DEPTH OF THE ABOVE
FREEZING WET BULB TEMPERATURES IS SUFFICIENT FOR ALL RAIN ACROSS
MOST OF THE AREA...ESPECIALLY THE FAR SOUTHEAST. HAVE TRENDED
PRECIPITATION TYPE TO MORE RAIN AS A RESULT. INCREASED QPF SLIGHTLY
IN THE FAR SOUTHEAST.
QUITE A BIT OF UNCERTAINTY DEVELOPS BY EARLY NEXT WEEK AND CONTINUES
THROUGHOUT THE EXTENDED PERIOD. VERY POWERFUL PACIFIC JET NOSES INTO
THE CENTRAL ROCKIES BY MONDAY EAST OF A SIGNIFICANT MEAN RIDGE OVER
THE EASTERN PACIFIC. A VERY STRONG TROUGH HAS BEEN SHOWN TO DEVELOP
OVER THE EASTERN UNITED STATES. THIS SHOULD HAPPEN BY AROUND
CHRISTMAS EVE OR CHRISTMAS DAY BUT MEDIUM RANGE MODELS STRUGGLE WITH
HOW IT EVOLVES EARLY/MID WEEK ONCE PACIFIC JET MOVES INTO THE
CENTRAL CONUS. NEW 12Z EMCWF IS QUICKER WITH DEVELOPING A CLOSED LOW
WHILE THE GFS IS MORE PRONOUNCED WITH INDIVIDUAL SHORTWAVES
TRAVERSING THE DEEPENING UPPER TROUGH. THE GFS BECOMES DEEPER BY
WEDNESDAY WITH MORE SUBSTANTIAL HEIGHT RISES ON ITS WEST SIDE OVER
THE PLAINS. EXACT IMPLICATIONS FOR US ARE UNCLEAR. WILL NEED TO
WATCH THE POTENTIAL FOR A DOWNSLOPING WARMING/WIND EVENT ON MONDAY.
GFS/MEX DEPICT THIS NOW. ECMWF IS MORE EXPANSIVE WITH HEIGHT FALLS
OVER THE CENTRAL CONUS GIVEN ITS MORE CONSOLIDATED/SPRAWLING
SOLUTION WITH LESS DISTINCT SHORTWAVES EMBEDDED WITHIN. GFS
SOUNDINGS SHOW DEEP MIXING INTO AN AREA OF STRONG FLOW ALOFT WHICH
RAISES SOME CONCERN OF NEAR ADVISORY CRITERIA WINDS IF THIS SOLUTION
VERIFIES. OTHERWISE DID NOT DEVIATE FROM MEDIUM RANGE CONSENSUS. ANY
PRECIPITATION IN THE EXTENDED SHOULD BE INSIGNIFICANT...AND
DIFFICULT TO TIME GIVEN MODEL DIFFERENCES.
BRB
.PREV DISCUSSION... /ISSUED 1142 AM CST THU DEC 18 2014/
.AVIATION...
FOR THE 18Z TAFS...THE MAIN WEATHER ELEMENTS FOR THIS FCST CYCLE WILL
BE LOW CLOUDS AND EPISODES OF FOG. FOG IS SLOWLY ERODING AT THE TAF
SITES AND SHOULD CONTINUE TO DO SO EARLY THIS AFTERNOON. IFR CIGS
WILL GRADUALY AND TEMPORARILY LIFT INTO THE MVFR CATEGORY AS WELL.
EXPECT THE RETURN OF IFR CIGS AND AREAS OF FOG AGAIN LATE TONIGHT
INTO FRIDAY MORNING. A FAST MOVING UPPER LEVEL STORM SYSTEM WILL
GRAZE THE REGION TONIGHT AND EARLY FRIDAY...AND MAY BRING SOME
SPRINKLES...LIGHT RAIN SHOWERS...FLURRIES...OR VERY LIGHT SNOW.
HOWEVER...THE CHANCE OF PRECIPITATION IS NOT VERY HIGH...SO HAVE
OPTED TO OMIT FROM THE TERMINAL FCSTS AT THIS TIME.
ANDRADE
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 33 43 29 55 28 / 20 20 5 0 5
BEAVER OK 29 45 28 52 30 / 10 20 5 0 5
BOISE CITY OK 26 49 24 53 22 / 10 5 5 0 0
BORGER TX 33 44 31 53 30 / 20 20 5 0 5
BOYS RANCH TX 31 49 27 56 25 / 20 10 5 0 0
CANYON TX 33 45 29 57 27 / 30 20 5 0 5
CLARENDON TX 35 41 33 54 34 / 30 30 5 0 5
DALHART TX 27 49 23 53 21 / 20 10 0 0 0
GUYMON OK 29 48 26 54 26 / 10 10 5 0 5
HEREFORD TX 32 51 27 58 26 / 30 20 5 0 5
LIPSCOMB TX 32 43 30 51 35 / 10 20 5 0 5
PAMPA TX 32 41 32 50 32 / 20 30 5 0 5
SHAMROCK TX 35 41 35 49 36 / 20 30 5 0 10
WELLINGTON TX 37 42 35 49 38 / 20 40 5 5 10
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
02/17
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
506 AM CST THU DEC 18 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 311 AM CST THU DEC 18 2014
PESKY UPPER TROUGH STILL LINGERS OVER THE GREAT LAKES WITH THE
LAST LOBE OF SHORT WAVE ENERGY HANGING BACK ACROSS LAKE SUPERIOR.
LOW CLOUDS ASSOCIATED WITH IT STILL COVER THE BULK OF WI...BUT ARE
STARTING TO SHOW SOME SIGNS OF BREAKING UP. MEANWHILE...SATELLITE
WATER VAPOR IMAGERY SHOWS A NICE CIRCULATION ENTERING THE WESTERN
DAKOTAS. VERY LITTLE MOISTURE WITH IT SO PRIMARILY RESULTING IN
CLOUD GENERATION. FINALLY...ANOTHER WEAK SHORT WAVE TROUGH WAS
TRAVERSING THE LOWER MISSISSIPPI RIVER VALLEY AND HEADING TOWARD
TENNESSEE. SOME PEEKS AT THE SUN ANTICIPATED TODAY WITH THE AREA
BETWEEN SYSTEMS...BUT WITH THE LOW ADVANCING ACROSS THE DAKOTAS
EXPECT MORE CLOUD TO INVADE. WITH ALL THE CLOUDS...KEPT DIURNAL
TEMPERATURE SWING SMALL.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 311 AM CST THU DEC 18 2014
MEDIUM RANGE FORECAST MODELS BEGINNING TO COME INTO BETTER
AGREEMENT WITH THE EXPECTED PATTERN FOR THE UPCOMING HOLIDAY WEEK.
BLOCKED PATTERN WILL EVOLVE BRIEFLY INTO ZONAL FOR THE WEEKEND
BEFORE CONTINUING ON TO FAVOR A DEEP LONG WAVE TROUGH OVER THE
CENTRAL CONUS BY EARLY NEXT WEEK...WITH A LARGE RIDGE SETTING UP
JUST OFF THE CALIFORNIA COAST. ENERGY DROPPING INTO THE BACK SIDE
OF THE TROUGH RESULTS IN THE DEVELOPMENT OF A CLOSED LOW OVER
MN/IA AREA BY MONDAY...WHICH THEN STALLS AND DEEPENS OVER THE
GREAT LAKES THROUGH MID WEEK. THIS WAS HINTED AT IN PREVIOUS
RUNS...BUT IS NOW LOOKING MORE AND MORE LIKELY WITH THE MODELS
GENERALLY SETTLING IN ON A VERY SIMILAR SOLUTION.
AS THE TROUGH BEGINS TO DEVELOP ON SATURDAY...INCREASING ADVECTION
OF WARM AND MOIST AIR BEGINS. FORECAST SOUNDINGS SUGGEST BROAD
WEAK LIFT WITH THE BOUNDARY LAYER BECOMING SATURATED OR NEARLY SO
LATE SATURDAY INTO SUNDAY. MODELS TRENDING TOWARD BETTER CHANCES
FOR PRECIPITATION...AND WITH THE TEMPERATURE REGIME STILL ON THE
COOL SIDE OF THE FREEZING MARK...FREEZING DRIZZLE APPEARS TO BE A
POSSIBILITY. ADDED THIS SATURDAY NIGHT...TRENDING TOWARD A
RAIN/SNOW MIX AS WE MOVE INTO THE DAY SUNDAY. PERSONS WITH TRAVEL
PLANS WILL WANT TO BE COGNIZANT OF THIS. BY MONDAY...SURFACE LOW
DEVELOPS AND MAIN FORCING OF THE DEVELOPING CLOSED LOW BEGINS TO
IMPACT THE FORECAST AREA. BOOSTED RAIN/SNOW CHANCES INTO THE
LIKELY CATEGORY FOR MONDAY AS A RESULT. THE AREA GETS ON THE COLD
SIDE OF THE SYSTEM BY TUESDAY WITH NORTHWEST WINDS USHERING COLD
AIR BACK INTO THE REGION. EXPECT PERIODS OF LIGHT SNOW OFF AND ON
THROUGH WEDNESDAY. WHILE IT DOES NOT APPEAR THAT LARGE QUANTITIES
OF SNOW WILL FALL...IT IS LOOKING MORE AND MORE LIKELY THAT WE
WILL SEE AT LEAST SOME LIGHT SNOW COVER BY CHRISTMAS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 506 AM CST THU DEC 18 2014
EXPANSIVE AREA OF MVFR CEILINGS REMAINS OVER MUCH OF WISCONSIN
EARLY THIS MORNING. SATELLITE INDICATES THIS HAS NOT BEEN MOVING
MUCH IF AT ALL AND DOUBTFUL THAT IT WILL EXPAND WESTWARD INTO
KRST THIS MORNING GIVEN THE LIGHT FLOW FROM THE LOW LEVEL RIDGE
AXIS OVER THE AREA. LOOKING AT THE 18.09Z RAP AND 18.06Z NAM...NOT
REALLY EXPECTING MUCH MOVEMENT OF THIS CLOUD DECK THROUGH THE
ENTIRE PERIOD SO WILL KEEP THE MVFR CEILING IN PLACE FOR KLSE. AT
KRST...THERE SHOULD BE A MID LEVEL VFR CEILING IN PLACE TO START
THE PERIOD WITH CLOUDS FROM THE STORM SYSTEM WELL SOUTH OF THE
AREA. ONCE THESE MOVE OUT...BOTH THE RAP AND NAM SUGGEST THE MVFR
CEILINGS WILL REDEVELOP AND WILL SHOW THIS HAPPENING AROUND 18Z
AND THEN PERSISTING THROUGH THE NIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...MW
LONG TERM...MW
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1039 PM MST WED DEC 17 2014
.UPDATE...
ISSUED AT 907 PM MST WED DEC 17 2014
DECIDED TO ISSUE A DENSE FOG ADVISORY FOR THE PLATTE RIVER VALLEY
BETWEEN TORRINGTON AND BRIDGEPORT. SFC OBSERVATIONS AND AREA WEB
CAMS CONFIRM VISIBILITIES OF ONE QUARTER OF A MILE OR LESS AT TOR
AND BFF AS OF 03Z THIS EVE. BIGGEST QUESTION IS JUST HOW LONG THIS
WILL LAST AS DRIER AIR IS TRYING TO WORK IN. RECENT HIGHRES MODEL
RUNS ARE TOO QUICK TO SHIFT WINDS AROUND TO THE WEST IN THIS LOW
GRADIENT PATTERN...SO AM CONFIDENT THE PLATTE RIVER VALLEY WILL
HANG ON TO A MOIST UPVALLEY FLOW OVERNIGHT. WITH SIGNIFICANT SNOW
COVER IN SCOTTS BLUFF COUNTY...THESE AREAS SHOULD HAVE NO PROBLEM
STAYING IN THE SOUP FOR SEVERAL HOURS. THE 01Z HRRR RUN SHOWS VSBY
LESS THAN ONE HALF MILE PERSISTING THROUGH AT LEAST 12Z AND FCST
SOUNDINGS SHOW EXCELLENT LLVL MOISTURE DURING THIS TIME. FREEZING
FOG HAS ALSO HAD A TENDENCY TO CREATE LIGHT ICING THE PAST FEW
NIGHTS...SO FELT AN ADVISORY WAS WARRANTED WITH THE ADDED RISK TO
TRAVEL. ALL OTHER ASPECTS OF THE FORECAST LOOK GOOD. UPDATES AND
NPW HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 351 PM MST WED DEC 17 2014
FOG AND LOW STRATUS LOOKS TO RETURN TONIGHT ACROSS THE PANHANDLE
AND ALSO CENTRAL AND WESTERN PORTIONS OF CARBON COUNTY AS
FORECAST SOUNDINGS SHOW NEARLY SATURATED LLVLS WITH LIGHT SSW
SURFACE WINDS IN PLACE FOR THESE AREAS. UPPER LEVEL WINDS WILL
REMAIN LIGHT AS WELL WITH LITTLE IN THE MEANS OF ANY DISTURBANCES
ALOFT DISRUPTING THE LOWER LEVELS...SO PERSISTENCE FORECAST SEEMS
REASONABLE. LIGHT SNOW WILL CONTINUE OVER THE MOUNTAINS IN THIS
PATTERN AS WELL...WITH GENERALLY LESS THAN AN INCH OF ACCUMULATION
EXPECTED. THINKING THAT THE FOG AND LOW STRATUS WILL NOT STICK
AROUND AS LONG TOMORROW AS TODAY/YESTERDAY AS A SHORTWAVE TROUGH
APPROACHES FROM THE PAC NW AND DEEPENS THE LEESIDE SFC PRESSURE
TROUGH...THUS INCREASING WEST WINDS ACROSS THE CWA AND NUDGING THE
LLVL MOISTURE EASTWARD. THE EXCEPTION COULD BE OUT WEST IN THE
LOWER ELEVATIONS OF CARBON COUNTY WHERE THE WESTERLY WINDS COULD
MAINTAIN INFLUX OF LLVL MOISTURE TO THIS AREA. LIKELY TO SEE WIND
GUSTS OF 30 TO 35 MPH IN THE WIND PRONE AREAS ALONG AND WEST OF
THE LARAMIE RANGE THROUGH THE DAY AS THE PRESSURE GRADIENT
STRENGTHENS IN ADVANCE OF THE UPPER TROUGH...WITH WARMING TEMPS
ACROSS THE EASTERN PLAINS WITH THESE DOWNSLOPE WINDS IN PLACE.
WINDS WILL INCREASE SLIGHTLY FOR THE WIND PRONE AREAS FOR TOMORROW
NIGHT AND FRIDAY AS THE UPPER LEVEL TROUGH MOVES OVERHEAD WITH
GUSTS OF 40 TO 50 MPH POSSIBLE THROUGH EARLY FRIDAY AFTERNOON.
EXPECTING LIGHT SNOW SHOWERS TO CONTINUE THROUGH THIS TIME ALONG
WITH SLIGHTLY WARMER TEMPS ACROSS THE PLAINS.
OTHERWISE...CONDITIONS WILL REMAIN DRY AND BREEZY THROUGH FRIDAY
NIGHT.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 351 PM MST WED DEC 17 2014
RATHER ZONAL FLOW SATURDAY WILL BECOME NWLY SATURDAY NIGHT AND
SUNDAY AS RIDGING AMPLIFIES ALONG THE WEST COAST. MAINLY DRY
OUTSIDE OF THE MTNS WHERE OROGRAPHICS SHOULD ALLOW FOR SOME SNOW
SHOWERS BOTH DAYS. LOOKING RATHER WINDY SAT NIGHT AND SUNDAY AS AN
UPPER JET MOVES INTO THE PACIFIC NW INTO THE NRN ROCKYS AND SFC
PRESSURE FALLS OCCUR OVER THE HIGH PLAINS AHEAD OF SHORTWAVE
ENERGY OVER THE PACIFIC NW. A COOL FRONT SHOULD THEN PASS ACROSS
LATE SUNDAY WITH A DECENT SURGE OF MOISTURE INCREASING SNOW SHOWER
ACTIVITY ESPECIALLY OVER THE SW PART OF THE CWA SUNDAY NIGHT AND
MONDAY. COOL AND SOMEWHAT BREEZY CONDITIONS EXPECTED FOR TUESDAY
AND WEDS AS THE CWA REMAINS UNDER NWLY FLOW ALOFT WITH SNOW
SHOWERS CONTINUING OVER THE HIGHER MTNS AS MOISTURE RIDES UP
FACING SLOPES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1031 PM MST WED DEC 17 2014
IFR/LIFR CONDITIONS WILL CONTINUE THROUGH ABOUT 15Z FOR THE NEB
PANHANDLE TERMINALS. VSBYS IN THE PLATTE RIVER VALLEY MAY BE LESS
THAN ONE QUARTER OF A MILE...ESPECIALLY AT KBFF/KTOR. CIGS WILL BE
AT OR NEAR AIRPORT MINIMUMS AROUND 200-300 FT AGL. CONDITIONS WILL
QUICKLY IMPROVE BY LATE THU MORNING OR EARLY AFTERNOON. WEST WINDS
WILL KEEP WIDESPREAD FOG AT BAY OVER SOUTHEAST WYO. HOWEVER PATCHY
DENSE FOG CANNOT BE RULED OUT OVER WESTERN CARBON COUNTY/KRWL OVER
THE NEXT FEW HOURS.
&&
.FIRE WEATHER...
ISSUED AT 351 PM MST WED DEC 17 2014
NO FIRE WEATHER CONCERNS THROUGH FRIDAY. COLD TEMPERATURES
WILL KEEP SNOW COVER ON THE GROUND ACROSS MUCH OF THE REGION.
AFTERNOON HUMIDITY VALUES WILL GENERALLY BE ABOVE 45 PERCENT AND
WINDS WILL BE WEAK THROUGH THURSDAY. BY THURSDAY NIGHT AND
FRIDAY...WEST WINDS WILL BECOME BREEZY FOR AREAS ALONG AND WEST
OF THE LARAMIE RANGE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...DENSE FOG ADVISORY UNTIL 8 AM MST THURSDAY FOR WYZ108.
NE...DENSE FOG ADVISORY UNTIL 8 AM MST THURSDAY FOR NEZ003-019-021-
096.
&&
$$
UPDATE...CLH
SHORT TERM...RJM
LONG TERM...RE
AVIATION...CLH
FIRE WEATHER...RJM
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
919 PM MST WED DEC 17 2014
.UPDATE...
ISSUED AT 907 PM MST WED DEC 17 2014
DECIDED TO ISSUE A DENSE FOG ADVISORY FOR THE PLATTE RIVER VALLEY
BETWEEN TORRINGTON AND BRIDGEPORT. SFC OBSERVATIONS AND AREA WEB
CAMS CONFIRM VISIBILITIES OF ONE QUARTER OF A MILE OR LESS AT TOR
AND BFF AS OF 03Z THIS EVE. BIGGEST QUESTION IS JUST HOW LONG THIS
WILL LAST AS DRIER AIR IS TRYING TO WORK IN. RECENT HIGHRES MODEL
RUNS ARE TOO QUICK TO SHIFT WINDS AROUND TO THE WEST IN THIS LOW
GRADIENT PATTERN...SO AM CONFIDENT THE PLATTE RIVER VALLEY WILL
HANG ON TO A MOIST UPVALLEY FLOW OVERNIGHT. WITH SIGNIFICANT SNOW
COVER IN SCOTTS BLUFF COUNTY...THESE AREAS SHOULD HAVE NO PROBLEM
STAYING IN THE SOUP FOR SEVERAL HOURS. THE 01Z HRRR RUN SHOWS VSBY
LESS THAN ONE HALF MILE PERSISTING THROUGH AT LEAST 12Z AND FCST
SOUNDINGS SHOW EXCELLENT LLVL MOISTURE DURING THIS TIME. FREEZING
FOG HAS ALSO HAD A TENDENCY TO CREATE LIGHT ICING THE PAST FEW
NIGHTS...SO FELT AN ADVISORY WAS WARRANTED WITH THE ADDED RISK TO
TRAVEL. ALL OTHER ASPECTS OF THE FORECAST LOOK GOOD. UPDATES AND
NPW HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 351 PM MST WED DEC 17 2014
FOG AND LOW STRATUS LOOKS TO RETURN TONIGHT ACROSS THE PANHANDLE
AND ALSO CENTRAL AND WESTERN PORTIONS OF CARBON COUNTY AS
FORECAST SOUNDINGS SHOW NEARLY SATURATED LLVLS WITH LIGHT SSW
SURFACE WINDS IN PLACE FOR THESE AREAS. UPPER LEVEL WINDS WILL
REMAIN LIGHT AS WELL WITH LITTLE IN THE MEANS OF ANY DISTURBANCES
ALOFT DISRUPTING THE LOWER LEVELS...SO PERSISTENCE FORECAST SEEMS
REASONABLE. LIGHT SNOW WILL CONTINUE OVER THE MOUNTAINS IN THIS
PATTERN AS WELL...WITH GENERALLY LESS THAN AN INCH OF ACCUMULATION
EXPECTED. THINKING THAT THE FOG AND LOW STRATUS WILL NOT STICK
AROUND AS LONG TOMORROW AS TODAY/YESTERDAY AS A SHORTWAVE TROUGH
APPROACHES FROM THE PAC NW AND DEEPENS THE LEESIDE SFC PRESSURE
TROUGH...THUS INCREASING WEST WINDS ACROSS THE CWA AND NUDGING THE
LLVL MOISTURE EASTWARD. THE EXCEPTION COULD BE OUT WEST IN THE
LOWER ELEVATIONS OF CARBON COUNTY WHERE THE WESTERLY WINDS COULD
MAINTAIN INFLUX OF LLVL MOISTURE TO THIS AREA. LIKELY TO SEE WIND
GUSTS OF 30 TO 35 MPH IN THE WIND PRONE AREAS ALONG AND WEST OF
THE LARAMIE RANGE THROUGH THE DAY AS THE PRESSURE GRADIENT
STRENGTHENS IN ADVANCE OF THE UPPER TROUGH...WITH WARMING TEMPS
ACROSS THE EASTERN PLAINS WITH THESE DOWNSLOPE WINDS IN PLACE.
WINDS WILL INCREASE SLIGHTLY FOR THE WIND PRONE AREAS FOR TOMORROW
NIGHT AND FRIDAY AS THE UPPER LEVEL TROUGH MOVES OVERHEAD WITH
GUSTS OF 40 TO 50 MPH POSSIBLE THROUGH EARLY FRIDAY AFTERNOON.
EXPECTING LIGHT SNOW SHOWERS TO CONTINUE THROUGH THIS TIME ALONG
WITH SLIGHTLY WARMER TEMPS ACROSS THE PLAINS.
OTHERWISE...CONDITIONS WILL REMAIN DRY AND BREEZY THROUGH FRIDAY
NIGHT.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 351 PM MST WED DEC 17 2014
RATHER ZONAL FLOW SATURDAY WILL BECOME NWLY SATURDAY NIGHT AND
SUNDAY AS RIDGING AMPLIFIES ALONG THE WEST COAST. MAINLY DRY
OUTSIDE OF THE MTNS WHERE OROGRAPHICS SHOULD ALLOW FOR SOME SNOW
SHOWERS BOTH DAYS. LOOKING RATHER WINDY SAT NIGHT AND SUNDAY AS AN
UPPER JET MOVES INTO THE PACIFIC NW INTO THE NRN ROCKYS AND SFC
PRESSURE FALLS OCCUR OVER THE HIGH PLAINS AHEAD OF SHORTWAVE
ENERGY OVER THE PACIFIC NW. A COOL FRONT SHOULD THEN PASS ACROSS
LATE SUNDAY WITH A DECENT SURGE OF MOISTURE INCREASING SNOW SHOWER
ACTIVITY ESPECIALLY OVER THE SW PART OF THE CWA SUNDAY NIGHT AND
MONDAY. COOL AND SOMEWHAT BREEZY CONDITIONS EXPECTED FOR TUESDAY
AND WEDS AS THE CWA REMAINS UNDER NWLY FLOW ALOFT WITH SNOW
SHOWERS CONTINUING OVER THE HIGHER MTNS AS MOISTURE RIDES UP
FACING SLOPES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 351 PM MST WED DEC 17 2014
VFR EXPECTED OVER SE WY TERMINALS THROUGH THE PERIOD. IFR TO MVFR
CIGS/VSBYS LIKELY TO SPREAD BACK ACROSS MUCH OF NEB PANHANDLE THIS
EVENING DUE TO SNOW COVER AND WEAK UPSLOPE FLOW.
&&
.FIRE WEATHER...
ISSUED AT 351 PM MST WED DEC 17 2014
NO FIRE WEATHER CONCERNS THROUGH FRIDAY. COLD TEMPERATURES
WILL KEEP SNOW COVER ON THE GROUND ACROSS MUCH OF THE REGION.
AFTERNOON HUMIDITY VALUES WILL GENERALLY BE ABOVE 45 PERCENT AND
WINDS WILL BE WEAK THROUGH THURSDAY. BY THURSDAY NIGHT AND
FRIDAY...WEST WINDS WILL BECOME BREEZY FOR AREAS ALONG AND WEST
OF THE LARAMIE RANGE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...DENSE FOG ADVISORY UNTIL 8 AM MST THURSDAY FOR WYZ108.
NE...DENSE FOG ADVISORY UNTIL 8 AM MST THURSDAY FOR NEZ003-019-021-
096.
&&
$$
UPDATE...CLH
SHORT TERM...RJM
LONG TERM...RE
AVIATION...RE
FIRE WEATHER...RJM
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
903 PM PST FRI DEC 19 2014
.UPDATE...
IR SATELLITE SHOWED ABUNDANT MOISTURE STREAMING INTO NORTHERN CA
AND OREGON THIS EVENING WITH RAIN AND HIGHER ELEVATION SNOW MOVING
INLAND. BOTH THE 00Z GFS/NAM HAVE COME IN STRONGER WITH ASSOCIATED
WARM ADVECTION LATE TONIGHT INTO SAT MORNING WITH QPF SIGNATURE
FURTHER SOUTH OVER WESTERN NV. WE HAVE BUMPED UP POPS AND BROUGHT
THEM FURTHER SOUTH. STEADY PRECIPITATION WILL BRING UP TO 1/10 TO
1/4 INCH OF QPF NORTH OF HIGHWAY 50 06Z-18Z SAT WITH LOCALLY
HIGHER TOTALS NORTH OF SUSANVILLE AND GERLACH AND ALONG THE CREST
NORTH OF LAKE TAHOE. THIS WILL RESULT IN 2-4 INCHES OF SNOW FOR
ELEVATIONS ABOVE MOST VALLEY FLOORS (ABOVE 5000 FEET NORTH OF
SUSANVILLE AND GERLACH AND ABOVE 6500 FEET FURTHER SOUTH NEAR THE
I-80 CORRIDOR) WITH ONLY LIGHT ACCUMULATIONS SLIGHTLY BELOW THESE
LEVELS INCLUDING LAKE LEVEL IN THE TAHOE BASIN. AS THE WARM
ADVECTION WANES SAT AFTERNOON, PRECIPITATION WILL BECOME MORE
SHOWERY. HOHMANN
&&
.PREVIOUS DISCUSSION... /ISSUED 250 PM PST FRI DEC 19 2014/
SYNOPSIS...
CHANCES FOR RAIN AND SNOW WILL GRADUALLY DIMINISH FROM SOUTH TO
NORTH THROUGH SATURDAY. ANY AMOUNTS WILL REMAIN LIGHT. HIGH
PRESSURE WILL BUILD IN FOR EARLY NEXT WEEK WITH MILD TEMPERATURES.
A STRONG COLD FRONT IS POSSIBLE LATE WEDNESDAY INTO THURSDAY WITH
SOME GUSTY WINDS, RAIN AND SNOW.
SHORT TERM...
MAIN BAND OF RAIN/SNOW IS NOW ALONG A SOUTH LAKE TO BATTLE MTN.
LINE AND IS PUSHING SOUTH AND EAST. THIS BAND WILL WEAKEN OVER THE
NEXT FEW HOURS WITH LIGHT AMOUNTS UP TO A TENTH OF AN INCH.
OTHERWISE ONLY EXPECT ISOLD SHOWERS WITH ONE EXCEPTION. BOTH THE
NAM AND HRRR SHOW ANOTHER BAND OF PRECIP DEVELOPING OVER CENTRAL
CA AND MOVING NORTHEAST INTO THE TAHOE BASIN THIS EVENING. A WEAK
WAVE IS PRESENT IN SATELLITE IMAGERY NEAR 127W AND THIS LOOKS LIKE
IT WOULD BE THE TRIGGER. KEPT SCT SNOW SHOWERS GOING IN THE SIERRA
FROM CARSON TO YUBA PASSES FOR THIS WAVE ALTHOUGH IT MAY BE MORE
WIDESPREAD THAN THIS. ANOTHER COUPLE INCHES OF SNOW REMAIN
POSSIBLE IN THIS BAND IF IT DEVELOPS.
A MILD NIGHT TONIGHT WITH CONTINUED CLOUD COVER AS ANOTHER STORM
MOVES INTO OREGON FOR SATURDAY. WE WILL CONTINUE TO SEE ABUNDANT
CLOUD COVER, BUT THE FORCING WITH THIS NEXT STORM WILL REMAIN WILL
NORTH WITH THE UPPER JET INTO THE COLUMBIA RIVER. THE EXCEPTION
WILL BE NORTH OF A SUSANVILLE TO GERLACH LINE WHERE SOME GOOD
ISENTROPIC LIFT IS SHOWING UP SATURDAY MORNING. INCREASED THE
THREAT OF RAIN/SNOW THERE WHILE KEEPING IT LOW CHANCE TO SLIGHT
CHANCE FURTHER SOUTH. IT APPEARS THERE WILL BE ABOUT A TENTH TO
QUARTER INCH OF PRECIP WITH IT.
THE GREATEST UNCERTAINTY THERE WILL BE THE SNOW LEVEL AND PRECIP
TYPE ON VALLEY FLOORS. NORMALLY IN A GOOD WARM AIR ADVECTION EVENT
LIKE THIS IT WOULD START AS SNOW WITH SOME ISOTHERMAL TEMP
PROFILES. HOWEVER, SURFACE TEMPS AND DEWPOINTS ARE 35-40 AND SEE
NO SIGNIFICANT DRYING OR COOLING TONIGHT AS MOISTURE AND CLOUDS
CONTINUE TO ARRIVE. RIGHT NOW, PUT SNOW LEVELS 4500-5000 FEET WITH A
RAIN/SNOW MIX IN THE SURPRISE VALLEY. IF IT IS ALL SNOW 1-2 INCHES
OF SNOW IS POSSIBLE BUT MY GUESS IS IT WILL BE IN THE FORM OF
RAIN.
BEHIND THE WARM FRONT, MID/HIGH CLOUDS WILL DIMINISH SATURDAY
NIGHT INTO SUNDAY. SOME SCATTERED LOW CLOUDS WILL CONTINUE AS
ABUNDANT LOW LEVEL MOISTURE GETS TRAPPED UNDER A SUBSIDENCE
INVERSION WITH THE STRONG RIDGE BUILDING IN. TEMPERATURES WILL
REMAIN MILD AND ABOVE NORMAL INTO EARLY NEXT WEEK WITH 50S DURING
THE DAY AND 20S AND 30S OVERNIGHT, COLDEST IN SIERRA VALLEYS.
WALLMANN
LONG TERM...TUESDAY THROUGH FRIDAY...
HIGH PRESSURE OVER THE WEST WILL GIVE WAY AROUND MID WEEK AS A
FAST-MOVING LOW PRESSURE SYSTEM MOVES INTO THE WEST COAST ON
CHRISTMAS EVE. THE GFS KEEPS THE SYSTEM FLAT AS IT MOVES THROUGH
THE REGION WHILE THE ECMWF/UKMET ARE BRINGING A STRONGER, DIGGING
SYSTEM INTO THE REGION. THE NWS WEATHER PREDICTION CENTER CONCURS
WITH A DIGGING SYSTEM AND THIS SOUNDS APPROPRIATE AS STRONG
SHORTWAVE ENERGY MOVING OFF OF JAPAN SATURDAY ARRIVES AT THE WEST
COAST ON WEDNESDAY (WHICH WOULD ENHANCE THE SYSTEM).
AS FAR AS THE DETAILS, THE DEVIL REMAINS AS THE 12Z ECMWF AND GEM
ARE NOW IMPLYING SOME SPLITTING AS THE SYSTEM MOVES INTO THE SIERRA
AND WESTERN NEVADA. I WOULD STILL EXPECT PRECIPITATION (AT LEAST IN
THE SIERRA AND IN THE BASIN NORTH OF HIGHWAY 50) WHETHER THE SYSTEM
BEGINS TO SPLIT OR NOT, ESPECIALLY AS THE GFS/EC SHOW A MODERATE
MOISTURE FEED (PWATS APPROACHING ONE INCH) BEING PULLED OFF OF A
SUBTROPICAL LOW NEAR HAWAII. HOWEVER, THE SPLIT WOULD LOWER
PRECIPITATION TOTALS AS THE SYSTEM`S COLD FRONT WEAKENS/FRACTURES.
ALSO, IT WOULD DELAY THE PUNCH OF COLD AIR ENOUGH THAT PRECIPITATION
WOULD START AS RAIN INITIALLY BELOW 5000-5500 FEET RATHER THAN BE A
MAINLY SNOW EVENT PER THE UNSPLIT/CONSOLIDATED SOLUTIONS.
AS FAR AS IMPACTS FOR EASTERN CALIFORNIA AND WESTERN NEVADA FOR THE
CHRISTMAS HOLIDAY, WIND GUSTS TO 35-45 MPH IN THE LOWER ELEVATIONS
ARE POSSIBLE WEDNESDAY WHICH WOULD CLEAR OUT ANY HAZE/POLLUTANTS IN
THE VALLEYS AND WARM HIGHS INTO THE 50S TO NEAR 60. PRECIPITATION
WISE, SNOW OR RAIN AND SNOW MAY START TO MOVE INTO AREAS NORTH OF
INTERSTATE 80 BY LATE WEDNESDAY AFTERNOON, THEN ACROSS THE
RENO-TAHOE AREA DURING CHRISTMAS EVE. THOSE TRAVELING CHRISTMAS EVE
AND CHRISTMAS MORNING SHOULD KEEP AN EYE ON THE FORECAST WITH
POTENTIAL IMPACTS DUE TO SNOW IN THE SIERRA AND ON THE LOWER VALLEY
FLOORS.
AFTER THE SYSTEM PASSES, A COLD NORTH SURFACE FLOW IS EXPECTED TO
KEEP AFTERNOON HIGHS FOR VALLEYS ON THURSDAY/CHRISTMAS DAY AND
FRIDAY IN THE 30S. THE CAVEAT IS THAT IF AT LEAST A FEW INCHES OF
SNOW FALLS ON CHRISTMAS EVE HIGHS ARE LIKELY TO REMAIN IN THE 20S
ALL DAY FOR LATE NEXT WEEK. FOR LOWS, SNOWFALL WOULD PUSH LOWS FROM
THE SINGLE DIGITS AND TEENS TO BELOW ZERO FOR MANY VALLEY LOCATIONS.
SNYDER
AVIATION...
A FRONT MOVING THROUGH THE AREA IS PRODUCING -SN/SN AND IFR
CONDITIONS IN THE SIERRA WITH ISOLD/SCATTERED SHOWERS AND HIGHER
TERRAIN OBSCURATION IN WESTERN NEVADA, MAINLY NORTH OF HIGHWAY 50.
THE FRONT IS ALSO KICKING UP WINDS GUSTS TO 20-25 KTS IN WESTERN
NEVADA NEAR/SOUTH OF I-80 AND DOWN INTO EASTERN MONO COUNTY.
FINALLY, TURBULENCE AND LIGHT RIMING ARE ALSO A GOOD BET OVER THE
SIERRA AND INTO WESTERN NEVADA WITH A RECENT PIREP INDICATING THIS
BETWEEN 090-190 MSL NEAR RENO.
FOR THIS EVENING, ANOTHER UPPER DISTURBANCE APPROACHING THE NORTHERN
CALIFORNIA COAST IS EXPECTED TO ENHANCE NORTHERN SIERRA SNOWFALL.
GIVEN THAT THE NEXT ROUND OF SIERRA SNOW WILL ARRIVE AFTER SUNSET
THERE COULD BE AN INCH OR TWO OF ACCUMULATION ON UNTREATED TARMACS
AND RUNWAYS AT KTRK AND KTVL. PLENTY OF MOISTURE AND A FEW LEFTOVER
-SHSN SHOULD ALLOW AREAS OF LOW CIGS AND TERRAIN OBSCURATION TO
PERSIST OVERNIGHT FOR THE SIERRA AND PORTIONS OF NORTHEAST
CALIFORNIA.
SATURDAY, ONE MORE ROUND OF LIGHT LOWER VALLEY RAIN AND MOUNTAIN
SNOW WILL AFFECT NORTHEAST CALIFORNIA AND NORTHERN NEVADA. THIS WILL
MEAN HIGHER TERRAIN OBSCURATION AND PERIODS OF MVFR CIGS FOR
NORTHERN SIERRA (KTVL/KTRK) TERMINALS, AS WELL AS THE POSSIBILITY
FOR BRIEF MVFR CIGS OUT INTO WESTERN NEVADA NORTH OF INTERSTATE 80.
SNYDER
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
353 AM EST SAT DEC 20 2014
.DISCUSSION...
CURRENTLY...
...INCREASING CHANCE FOR SHOWERS/STORMS LATE SUNDAY INTO WED...
BROAD HI PRES RIDGE BLANKETING THE SW ATLC WITH A WEAK COLD FRONT
OVER THE GOMEX. EVENING SOUNDINGS SHOW INCREASING MOISTURE ACRS THE
PANHANDLE ASSOCD WITH THE FRONT WITH PWAT VALUES CREEPING ABV 1.0".
OVER CENTRAL FL...KTBW SOUNDING MEASURED PWATS ARND 0.8"...THOUGH
MOST OF THIS IS IN THE FORM OF A MID/UPR LVL DECK AS AVG DEWPOINT
DEPRESSIONS THRU THE H100-H70 LYR REMAIN BTWN 10-15C. TO THE S...
KMFL SHOWS SUBSTANTIAL DRY AIR THRU THE H85-H50 LYR. RUC ANALYSIS
INDICATES UPSTREAM H100-H70 MEAN RH VALUES INCREASING FROM 40PCT
OVER S FL TO AOA 80PCT OVER THE YUCATAN CHANNEL...AND H85-H50 VALUES
INCREASING FROM ARND 40PCT OVER CENTRAL FL TO AOA 60PCT OVER THE
CENTRAL GOMEX.
ALOFT...A 90-110KT JET STREAK EXTENDING FROM THE BAJA PENINSULA TO
BERMUDA HAS A STRONG ZONAL ORIENTATION THAT IS GENERATING A DEEP
W/SW FLOW THRU THE H85-H30 LYR. MODERATELY COOL AIR AIR IN PLACE
WITH H50 TEMPS ARND -10C. SIG VORT MAXES ARE ALMOST NONEXISTENT THRU
THE H85-H30 LYR...WHILE THE OMEGA FIELDS THRU THE SAME LYR ARE
BASICALLY NEUTRAL. H70-H50 LAPSE RATES ARND 6.0C/KM ARE NOT
ESPECIALLY IMPRESSIVE...ESPECIALLY GIVEN THE H85-H70 LAPSE RATES ARE
BLO 5.0C/KM.
TODAY-TONIGHT...
THE RIDGE AXIS WILL BE THE PRIMARY WX FEATURE FOR CENTRAL FL AS THE
JET OVER THE SRN TIER STATES DRAGS THE WEAK COLD FRONT INTO THE FL
PANHANDLE. HOWEVER...THE ZONAL ORIENTATION OF THE JET WILL PREVENT
THE FRONT FROM PUSHING MUCH FURTHER S THAN THE NECK OF THE PENINSULA
BY DAYBREAK SUN.
RUC40 ANALYSIS SHOWS A TIGHT ISENTROPIC GRADIENT THRU THE 300K-315K
LYR THAT WILL EVENTUALLY SET THE STAGE FOR THE NEXT RAIN EVENT ACRS
CENTRAL FL AS THE MID LVL WINDS REMAIN OUT OF THE W/SW. HOWEVER...
THE DRY AIR OVER THE CENTRAL/SRN PENINSULA WILL NEED TO MODIFY
BEFORE ANY MEASURABLE PRECIP OCCURS...ESPECIALLY GIVEN THE LACK OF
ANY SIG DYNAMIC/THERMODYNAMIC SUPPORT.
FORECAST WILL REMAIN DRY. TEMPS WILL BE A FEW DEG WARMER THAN FRI
DUE TO WARM AIR ADVECTION THAT WILL ACCOMPANY THE S/SW FLOW THAT HAS
DVLPD THRU THE H100-H85 LYR. AFTN MAXES IN THE M/U70S WILL BE 3-7F
DEG ABV AVG. OVERNIGHT MINS IN THE M/U50S EXCEPT L60S ALONG THE
IMMEDIATE COAST...5-10F ABV AVG.
SUN-WED...MODELS CONTINUE TO SHOW A QUITE CLOUDY PERIOD WITH
DAILY RAIN CHANCES.
SUN-MON...A TROUGH WITH FAIRLY DECENT SOUTHERN EXTENT INTO THE
WESTERN GULF ON SUNDAY WILL DAMPEN OUT AS IT MOVES ACROSS THE
SOUTHEAST STATES SUNDAY NIGHT/MON. THERE WILL INITIALLY BE A MID
LEVEL DRY LAYER SUNDAY BUT INCREASING SOUTH/SOUTHWEST FLOW IN THE
LOW/MID LEVELS WILL MOISTEN UP THE ATMOSPHERE CONSIDERABLY BY LATE
DAY AND SUNDAY NIGHT. GFS/ECMWF DIFFER A BIT WITH HIGHEST PRECIP
COVERAGE. THE GFS SHOWS HIGH POPS AREAWIDE SUNDAY NIGHT INTO MON.
THE ECMWF CONCENTRATES THE HIGHEST COVERAGE ACROSS NORTHERN
SECTIONS...WHICH IS MORE TYPICAL FOR THIS TIME OF THE YEAR AND
WHERE THE GREATEST ISENTROPIC LIFT IS SHOWN. THEREFORE HAVE NOT
GONE WITH THE 60-70 POPS INDICATED BY THE GFS...EXCEPT ACROSS THE
FAR NORTH. THINK THAT PRECIP WILL MAINLY BE SHOWERY BUT CANNOT
RULE OUT SOME ELEVATED INSTABILITY AND ISOLATED THUNDER.
TUE-WED...THE MODELS ONLY SHOW SLIGHT CHANGES WITH THE NEXT
TROUGH WHICH WILL BE HIGHLY AMPLIFIED AND DIG WELL INTO THE GULF
OF MEXICO. A PRE FRONTAL BAND OF SHOWERS/STORMS IS EXPECTED TO
PUSH INTO NORTHERN SECTIONS TUE NIGHT AND SOUTHERN SECTIONS WED.
THIS IS SLIGHTLY SLOWER THAN PREVIOUS THINKING. THE DEEPENING
SURFACE LOW ASSOCIATED WITH THIS SYSTEM WILL BE LIFTING INTO THE
OHIO VALLEY AS THE BAND OF CONVECTION REACHES THE LOCAL AREA.
STILL THE LOW LEVEL WIND FIELDS ARE PROGGED TO BE 40-45 KNOTS. SO
FAST MOVING STORMS ARE EXPECTED WHICH MAY BRING A CHANCE FOR
DAMAGING WIND GUSTS.
HAVE GONE WITH CHANCE POPS ON TUE DUE TO THE MOIST SOUTHERLY FLOW
AND KEPT MENTION OF THUNDER DUE TO A POTENTIAL FOR SOME
DIVERGENCE ALOFT IN THE PRESENCE OF MODEST SURFACE HEATING.
GREATEST DYNAMICS ARE INDICATED TUE NIGHT INTO WED SO HAVE GONE
WITH A PERIOD OF LIKELY POPS FOR THE ENTIRE AREA THEN.
CHRISTMAS THRU NEXT SAT...
COOL/DRY AIR ADVECTION INDICATED ON CHRISTMAS DAY. MORNING LOWS IN
THE UPPER 40S TO LOWER 50S EXPECTED WITH DAYTIME HIGHS IN THE
LOWER TO MID 60S. HIGH PRESSURE RIDGE OVER THE AREA ON FRI WILL
CONTINUE THE DRY WEATHER AND AFTER A COOL MORNING IN THE MID 40S
TO LOWER 50S...A SLOW MODERATION OF TEMPERATURES TO THE UPPER 60S
AND LOWER 70S IS EXPECTED. THE NEXT APPROACHING FRONT SHOULD
WEAKEN AS IT RUNS INTO WEAKENING SURFACE RIDGE...SO WILL KEEP THE
FORECAST DRY ON SAT AS TEMPERATURES MODIFY TO NORMAL OR A LITTLE
ABOVE.
&&
.AVIATION...
SFC WINDS: THRU 20/15Z...VRBL AOB 3KTS. BTWN 20/15Z-20/18Z...S BTWN
4-7KTS. WNDSHFT TO E/SE 5-8KTS AFT 20/18Z...BTWN 20/18Z-20/20Z CSTL
SITES...BTWN 20/21Z-20/23Z INTERIOR SITES. AFT 21/00Z...VRBL AOB
3KTS.
VSBYS: THRU 20/13Z...LCL MVFR/BRIEF IFR IN BR. AFT 20/13Z VFR ALL
SITES.
CIGS: THRU 20/13Z...AREAS AOA FL120 N OF KTIX-KISM...LCL MVFR CIGS
BTWN FL020-030 CSTL SITES S OF KMLB. AFT 20/13Z...VFR ALL SITES...
PREVAILING CIGS AOA FL120 N OF KMLB-KISM...BCMG FL100-120 AFT 20/18Z.
&&
.MARINE...
TODAY-TONIGHT...A WEAK AND BROAD HI PRES RIDGE BLANKETING THE REGION
FROM THE CAROLINA COAST TO THE BAHAMA BANK WILL GENERATE A LIGHT TO
GENTLE SRLY BREEZE ACRS THE LCL ATLC THRU EARLY AFTN. WINDS WILL
SHIFT TO THE E/SE BY MID AFTN AS THE SEABREEZE FORMS...BUT THE WEAK
PGRAD WILL NOT SUPPORT ANYTHING GREATER THAN 10KTS. WINDS WILL
CONTINUE E/NE OVERNIGHT AS A WEAK FRONTAL BOUNDARY DRIFTS INTO THE
FL PANHANDLE. SEAS AOB 2FT.
SUNDAY...SOUTHEAST FLOW STILL INDICATED AT 10 KNOTS OR LESS. THE
DAY LOOKS QUITE CLOUDY WITH A CHANCE OF SHOWERS LATE IN THE DAY
ESPECIALLY CANAVERAL NORTHWARD.
MON-WED...WINDS WILL BECOME SOUTH/SOUTHWEST AND INCREASE AHEAD OF
A COLD FRONT ESPECIALLY TUE-WED. EXPECT A CHANCE FOR SHOWERS AND
SLIGHT CHANCE FOR STORMS IN A MOIST AIR MASS MON/TUE...BUT A
PERIOD OF STRONG STORMS IS EXPECTED LATE TUE NIGHT AND INTO WED.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 73 59 74 64 / 10 10 30 70
MCO 76 59 77 64 / 0 10 20 50
MLB 77 62 77 66 / 0 10 20 50
VRB 77 61 77 64 / 0 10 10 40
LEE 75 58 76 63 / 0 10 30 70
SFB 76 59 76 64 / 0 10 30 60
ORL 76 60 76 64 / 0 10 30 60
FPR 77 60 77 65 / 0 10 10 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...BRAGAW
LONG TERM....LASCODY
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
303 AM CST SAT DEC 20 2014
...SHORT TERM...TODAY THROUGH SUNDAY...
302 AM CST
THE MAIN CONCERNS DURING THE SHORT TERM WILL BE WILL BE CENTERED
AROUND THE POTENTIAL FOR SOME FREEZING DRIZZLE ACROSS PORTIONS OF
NORTHERN ILLINOIS LATE TONIGHT INTO EARLY SUNDAY MORNING.
SURFACE HIGH PRESSURE CONTINUES TO BE IN PLACE ACROSS THE GREAT
LAKES REGION EARLY THIS MORNING. HOWEVER...ATTENTION FOR TODAY IS
FOCUSED ON A MID LEVEL DISTURBANCE...CURRENTLY NOTED IN THE WATER
VAPOR IMAGERY ACROSS SOUTHWESTERN IOWA. THIS DISTURBANCE WILL SHIFT
EASTWARD ACROSS CENTRAL AND NORTHERN ILLINOIS THROUGH EARLY THIS
AFTERNOON. OVERALL...MODEL SOUNDINGS DO NOT APPEAR ALL THAT
FAVORABLE FOR ANY LIGHT SNOW. HOWEVER...THERE HAVE BEEN SOME REPORTS
OF LIGHT FLURRIES ACROSS IOWA EARLY THIS MORNING...SO I HAVE OPTED
TO KEEP THE MENTION OF SOME FLURRIES GOING ACROSS THE AREA THROUGH
EARLY AFTERNOON.
WARM AIR ADVECTION/ISENTROPIC ASCENT WILL INCREASE
ACROSS MUCH OF THE MIDWEST AND GREAT LAKES REGION LATER TONIGHT INTO
SUNDAY MORNING IN RESPONSE TO AN INCREASING SOUTHERLY WIND FIELD
AHEAD OF A DEVELOPING STORM SYSTEM ACROSS THE NORTHERN HIGH PLAINS.
IT APPEARS THAT THIS WARM AIR ADVECTION WILL BE ENOUGH TO RESULT IN
THE DEVELOPMENT OF SOME FREEZING DRIZZLE OR LIGHT SNOW. MODEL
SOUNDINGS...ESPECIALLY FROM THE NAM SUGGEST CLOUD HEIGHTS WILL ONLY
REACH TO AROUND -7 DEGREES CELSIUS...SUGGESTING THE POSSIBILITY OF A
DEARTH OF ICE CRYSTALS IN THE CLOUDS. AS SUCH...THIS INCREASES THE
THREAT FOR FREEZING DRIZZLE VERSES LIGHT SNOW. OVERALL...THIS WILL
BE A VERY LIGHT EVENT...AND APPEARS TO MAINLY BE CONFINED ACROSS
NORTH CENTRAL ILLINOIS...THOUGH PORTIONS OF THE CHICAGO AREA COULD
ALSO EXPERIENCE SOME. THE PRIMARY TIMING FOR THIS ACTIVE LOOKS TO
BE AFTER MIDNIGHT TONIGHT THROUGH AROUND MID MORNING ON SUNDAY.
THEREAFTER...SURFACE TEMPERATURES SHOULD WARM ABOVE FREEZING ENDING
THE THREAT OF FREEZING PRECIP.
KJB
&&
LONG TERM...MONDAY THROUGH FRIDAY...
NOT MUCH HAS CHANGED IN THE EXPECTATION OF A TRANSITIONING WEATHER
PATTERN ACROSS THE CONUS SUPPORTIVE OF SEVERAL PERIODS OF INCLEMENT
WEATHER THROUGH MUCH OF THE UPCOMING HOLIDAY WEEK. THEREFORE...THE
MAIN CONCERNS DURING THE LONG TERM PERIOD WILL FOCUS AROUND THE
CHANCES AND TIMING OF RAINFALL MONDAY INTO TUESDAY...THEN THE
POTENTIAL FOR A SIGNIFICANT WINTER STORM SOMEWHERE ACROSS THE GREAT
LAKES REGION INTO CHRISTMAS EVE.
A VERY IMPRESSIVE NORTHERN PACIFIC JET STREAK IS EXPECTED TO DEVELOP
EASTWARD ONSHORE ACROSS THE PACIFIC NORTHWEST BY EARLY SUNDAY...THEN
BEGIN TO DIG A SIGNIFICANT UPPER LEVEL TROUGH ACROSS THE CENTRAL
CONS BY MID WEEK. MODEL GUIDANCE CONTINUES IN GOOD AGREEMENT IN
TRACKING AN INITIAL AREA OF LOW PRESSURE EASTWARD FROM THE NORTHERN
HIGH PLAINS TO THE UPPER MISSISSIPPI VALLEY BY TUESDAY. THIS WOULD
KEEP ALL OF NORTHERN ILLINOIS/NORTHWESTERN INDIANA IN THE WARM
SECTOR THROUGH EARLY TUESDAY...THUS ASIDE FROM A SMALL POSSIBILITY OF
THE PRECIP BEGINNING AS A MIX OF SLEET AND RAIN AT ONSET EARLY
MONDAY...IT APPEARS THAT WE WILL BE IN FOR A RAIN EVENT ACROSS THE
ENTIRE AREA MONDAY AFTERNOON INTO MONDAY NIGHT.
THINGS BEGIN TO GET REALLY TRICKY LATE TUESDAY AND INTO CHRISTMAS
EVE...AS MODEL GUIDANCE IS INSTANT IN SECONDARY VORT MAX DIGGING
SOUTH AND ACROSS THE LOWER MISSISSIPPI VALLEY BY TUESDAY
NIGHT...LEADING TO A VERY AMPLIFIED AND INCREASING NEGATIVELY TILTED
UPPER TROUGH ACROSS THE CENTRAL CONUS. THIS IS A CLASSIC UPPER LEVEL
PATTERN SUPPORTIVE OF TREMENDOUS ATMOSPHERIC DYNAMICS AND HENCE
RAPID AND DEEP CYCLOGENESIS...SOMEWHERE ACROSS THE GREAT LAKES
REGION. IN FACT...THIS COULD RESULT IN "BOMB CYCLOGENESIS"...WHICH IS
DEFINED AS A DEEPENING RATE OF THE LOWS CENTRAL PRESSURE OF 24 MB IN
AS MANY HOURS. MODEL GUIDANCE CONTINUES TO BE IN SOME DISAGREEMENT IN
WHERE EXACTLY THIS STORM SYSTEM WILL TRACK INTO CHRISTMAS EVE.
HOWEVER...SUPPORT IS IN PLACE TO SUGGEST A GOOD POTENTIAL OF A
STRONG STORM SYSTEM ACROSS THE REGION DURING THIS PERIOD.
UNFORTUNATELY...THE ACTUAL TRACK OF THE STORM WILL BE THE DIFFERENCE
IN IF WE END UP WITH LITTLE OR NO SNOW...OR A SIGNIFICANT WINTER
STORM ACROSS THE AREA. THE LIKELIHOOD OF VERY STRONG WINDS WITH SUCH A
DEEP LOW COULD ALSO RESULT IN SIGNIFICANT BLOWING SNOW...IF IT DOES
OF COURSE SNOW THIS FAR WEST. THEREFORE...THIS STORM BEARS
SIGNIFICANT ATTENTION IN THE COMING DAYS.
FOLLOWING THIS SYSTEM...YET ANOTHER STORM SYSTEM COULD TAKE AIM ON
THE AREA BY FRIDAY. HOWEVER...UNCERTAINTY WITH THIS STORM IS
EXTREMELY HIGH...GIVEN THAT THE ACTUAL EVOLUTION OF THE FIRST STORM
SYSTEM WILL NEED TO BE IRONED OUT. OVERALL THOUGH IT LOOKS LIKE WE
ARE ENTERING INTO AN ACTIVE WEATHER PERIOD THROUGH THE REST OF THE
FORECAST PERIOD.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* MVFR CEILINGS LIKELY BECOMING VFR BEFORE SUNRISE. EXPECTED TO
LOWER TO MVFR AGAIN THIS EVENING.
* LIGHT/VARIABLE WINDS BECOMING LIGHT SOUTH-SOUTHWEST BY MIDDAY.
RATZER
//DISCUSSION...UPDATED 06Z...
WEAK SURFACE HIGH PRESSURE RIDGE MOVING SLOWLY EAST ACROSS THE
AREA THIS MORNING. CALM OR LIGHT/VARIABLE WINDS AND MVFR CLOUDS
TRAPPED BENEATH SHALLOW INVERSION PERSISTING. SURFACE OBS INDICATE
MVFR CEILINGS ERODING FROM THE SOUTHWEST HOWEVER...WITH THE
POTENTIAL FOR CONDITIONS TO BECOME VFR AT TAF SITES DURING THE
PRE-DAWN HOURS. QUESTION IS HOW LONG VFR LASTS...AS EXTENSIVE AREA
OF MVFR/IFR CEILINGS WEST OF THE MISSISSIPPI RIVER WILL EVENTUALLY
SPREAD INTO THE AREA TONIGHT. KRFD BEING FARTHER WEST LOOKS TO BE
BACK INTO MVFR CONDITIONS PERHAPS AS EARLY AS MID-LATE MORNING.
CEILINGS WILL LIKELY LOWER INTO IFR RANGE LATE THIS EVENING INTO
EARLY SUNDAY...WITH THE POTENTIAL FOR SOME FLURRIES OR FREEZING
DRIZZLE DEVELOPING SUNDAY MORNING.
CALM OR LIGHT/VARIABLE WINDS LESS THAN 5 KT WILL BECOME SOUTH-
SOUTHWEST AT 5 KT BY EARLY AFTERNOON AND REMAIN LIGHT SOUTH
THROUGH TONIGHT.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM IN CEILING TRENDS AND VFR DURATION TODAY.
* HIGH IN WIND TRENDS.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...MVFR CIGS. SOUTH WINDS.
MONDAY...MVFR CIGS. BRIEF PERIOD OF RAIN OR MIXED RAIN AND SNOW.
TUESDAY...MVFR CIGS. CHANCE OF RAIN.
WEDNESDAY...MVFR CIGS. BLUSTERY - GUSTY WEST WINDS. CHANCE OF
SNOW.
THURSDAY...VFR.
ED F
&&
.MARINE...
137 AM CST
THE MAIN MARINE FORECAST CONCERNS THIS MORNING FOCUS ON A COUPLE OF
PERIODS OF STRONG WINDS OVER THE NEXT SEVERAL DAYS...SOUTH AND
SOUTHEAST WINDS 25-30 KT DEVELOPING SUNDAY AND CONTINUING THROUGH
MONDAY EVENING...THEN THE POTENTIAL FOR WEST HIGH GALES LATE
WEDNESDAY THROUGH THURSDAY...CHRISTMAS EVE AND CHRISTMAS DAY.
IN THE NEAR TERM...WEATHER IS QUITE TRANQUIL ACROSS LAKE MICHIGAN
THIS MORNING AS DIFFUSE HIGH PRESSURE WAS DRIFTING SLOWLY EAST
ACROSS THE REGION. THE RIDGE AXIS WILL SHIFT EAST OF THE LAKE THIS
AFTERNOON ALLOWING CURRENT VARIABLE WINDS TO BECOME SOUTHERLY. SOUTH
WINDS WILL GRADUALLY INCREASE LATE TONIGHT AND SUNDAY AS AN AREA OF
LOW PRESSURE DEVELOPS SOUTHEAST IN THE LEE OF THE NORTHERN ROCKIES
WITH A CORRESPONDING TIGHTENING OF THE SURFACE PRESSURE GRADIENT
BETWEEN THE LOW AND THE HIGH TO EAST OF THE LAKES. MODEL FORECAST
SOUNDINGS SUPPORT WINDS 20-25 KT SUNDAY AFTERNOON INCREASING TO 30
KT SUNDAY NIGHT/MONDAY...BECOMING A BIT MORE SOUTHEAST LATE MONDAY
AS THE SURFACE LOW MOVES INTO THE UPPER MIDWEST.
THE SURFACE LOW IS EXPECTED TO FILL A BIT ACROSS THE REGION TUESDAY
AS IT OCCLUDES. MODEL FORECASTS CONTINUE TO DEPICT A COMPLEX
EVOLUTION BY MID-WEEK HOWEVER...WITH A SECOND AREA OF LOW PRESSURE
FARTHER SOUTH ALONG THE COLD FRONT DEEPENING AND WRAPPING NORTHWARD
INTO THE GREAT LAKES WEDNESDAY AND THURSDAY. SPREAD REMAINS AMONGST
MODEL FORECASTS OF THE EXACT TRACK AND DEPTH OF THIS LOW...BUT IT
DOES APPEAR THAT A DEEPENING SUB-980 MB LOW WILL TRACK NORTH ACROSS
THE GREAT LAKES REGION CHRISTMAS EVE INTO CHRISTMAS DAY. SUCH A LOW
PASSING EAST OF LAKE MICHIGAN SUPPORTS THE POTENTIAL FOR THE
DEVELOPMENT OF WESTERLY GALES ON THE LAKE...PERHAPS HIGH GALES ABOVE
40 KT...FROM WEDNESDAY AFTERNOON OR EVENING THROUGH THE DAY
THURSDAY.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
330 AM CST Sat Dec 20 2014
.SHORT TERM...(Today)
ISSUED AT 329 AM CST SAT DEC 20 2014
Latest satellite data indicating a shortwave trof near Omaha which
is expected to push across our area later this morning. Upstream
surface observations across central and east central Iowa have had
some reports of some very light freezing drizzle and flurries to the
east of the main area of lift, with even some very light flurries
reported this past hour in St. Louis. A secondary shortwave was
noted over parts of southern Missouri into the lower Ohio Valley
that has produced a band of light snow which extended along and
south of the I-70 corridor early this morning. That system will
shift off to our east over the next few hours taking the light snow
out of southeast Illinois by dawn.
As the compact shortwave over the Missouri Valley tracks across the
area, many of the forecast soundings are not showing much in the way
of support for widespread precip as high pressure at the surface is
still holding firm over east central Illinois this morning. We see
moisture in the 850-800 mb layer over most of the area with not a
great deal above that until later this morning when the main area of
lift associated with the vort max swings thru. Much of the stratus/low
level moisture will remain to our west thru the morning as well before
tracking slowing into west central Illinois this afternoon. Will carry
chances for flurries this morning, mainly over west central Illinois
ahead of the vort max, as we see some mid level moisture/lift track
just to the west of our forecast area. Most of the short term high
resolution models continue to suggest as the shortwave moves across
the remainder of the state, moisture profiles will not support much
in the way of precip further east this afternoon. Despite the more
widespread cloud cover over our area today, we should see afternoon
temperatures a few degrees warmer than yesterday with readings
ranging from the mid 30s north to around 40 south.
&&
.LONG TERM...(Tonight through Friday)
ISSUED AT 329 AM CST SAT DEC 20 2014
Fairly quiet weather expected tonight through Sunday night across
central and southeast IL as surface ridge shifts east into New
England and the mid Atlantic states Sunday. Temps to gradually
modify next few days with increasing southerly flow especially by
Monday. Added patchy drizzle/freezing drizzle to the IL river valley
overnight with the low clouds as surface temps are close to
freezing. Mostly cloudy skies expected Sunday with more low clouds
prevailing over northern counties. Highs in the lower 40s Sunday
which will be a bit above normal highs in the mid to upper 30s.
Added slight chance of light rain late Sunday night around Galesburg
with best rain chances arriving during the day Monday especially by
Monday afternoon NW areas and Monday night into Tue across area.
Strong low pressure near Pacific NW to track into MN Monday night
and increase chances of rain over IL ahead of approaching low
pressure and cold front. Milder highs in the 40s Monday and Tue with
Lawrenceville around 50F.
Forecast models then deepen another area of low pressure from the
southern plains into KY by dawn Wed and then into eastern lower MI
or just east of there by sunset Wed. Colder air to be drawn into IL
Tue night and Wed with rain changing to snow during Tue night and
continue good chances of light snow Wed. Could be some light snow
accumulations overnight Tue night into Wed especially over
eastcentral IL. Windy conditions expected Wed and Wed night as
deepening low pulls away with strong west winds gusting 25-35 mph.
Dry conditions expected on Christmas Day over the state as IL will
be inbetween strong low pressure exiting into eastern Canada and new
low pressure developing over Texas Panhandle by sunset Thu. This low
pressure ejects ne into the western Great Lakes by sunset Friday and
returns good chances of precipitation with southeast IL mainly rain
and a mix of rain/snow over central IL. Extended models show active
weather pattern looks to continue beyond day 7.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
ISSUED AT 1118 PM CST FRI DEC 19 2014
VFR conditions will begin the TAF period for most of the TAF
sites...with the exception being CMI where MVFR VIS is already in
place. Some of the issues with the TAFs tonight are the timing of
MVFR VIS and lowering CIGs. The surface high that was over
Illinois earlier is slowly pushing east with light to calm winds
remaining over much of central Illinois. Winds are also slowly
shifting to the east southeast allowing the low level moisture to
filter in both from the east and the west. Locations over Missouri
and Indiana have MVFR VIS and CIGs with locations in Missouri
under IFR CIGs. Given the complexity involved with timing of lower
VIS and CIGs...confidence is fairly low in the TAF forecast past
the first 6 hours. Currently have MVFR conditions over PIA
starting at 09Z...at 08Z for BMI and DEC...and at 12Z for SPI.
Mainly went with the HRRR since it seemed to have a pretty good
handle on the previous forecast. Also included a TEMPO group for
CMI as all guidance had IFR VIS over the site between 09Z and 13Z.
Only included a TEMPO for now since confidence in the timing is
lower. VFR conditions could resume around 16Z for the sites after
the next upper level wave moves through Illinois...but this could
change with the next TAF issuance.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Smith
LONG TERM...07
AVIATION...ALW
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1155 PM CST FRI DEC 19 2014
.SHORT TERM...
237 PM CST
THROUGH SATURDAY...
UNFORTUNATELY IT LOOKS LIKE WE WILL REMAIN LOCKED IN THE CLOUDS YET
AGAIN TONIGHT...DESPITE A CLEARING WEDGE THAT EXTENDS FROM
WESTCENTRAL IL TO SOUTHERN IN. WITH HIGH PRESSURE OVERHEAD THE
ABILITY TO MIX TO THE SFC DRIER AIR HAS BEEN NONEXISTENT. WITH THE
CONSIDERABLE SOLAR SHIELDING THIS AFTERNOON...SFC TEMPS HAVE BEEN
UNABLE TO WARM MUCH. TEMPS IN MOST LOCATIONS HAVE REMAINED ARND 30
TO A FEW LOW 30S ACROSS THE FAR SOUTHERN CWFA. OVERNIGHT THE SFC
RIDGE WILL DRIFT EAST...ALLOWING LGT/VRB WINDS TO SLOWLY TURN
SOUTHWESTERLY BY DAYBREAK SAT. OVERNIGHT LOWS WILL GENERALLY BE IN
THE LOW/MID 20S...BUT IF CLOUDS REMAIN THICK ENOUGH IT IS PLAUSIBLE
THAT TEMPS COULD HOLD IN THE MID/UPR 20S. GUIDANCE HAS INDICATED A
WEAK LOBE OF VORTICITY ALONG THE NORTHERN STREAM PUSHING EAST ACROSS
THE NORTHERN PLAINS OVERNIGHT...ARRIVING ACROSS THE GREAT LAKES
REGION AROUND SAT MORNING. WHILE IT APPEARS MOST OF THE NEAR SFC
WILL REMAIN DRY...THERE IS SOME WEAK FORCING IN THE MID-LVLS ALONG
WITH MARGINAL SATURATION THAT SOME FLURRIES COULD OCCUR DURING THE
MORNING HOURS. WITH YET ANOTHER DAY OF CONTINUED CLOUDINESS SAT...IT
APPEARS LESS FAVORABLE FOR ANY BUMP TO THE TEMPS. SO HAVE NUDGED
TEMPS DOWN A DEGREE TO THE MID 30S ACROSS THE CWFA.
SATURDAY NIGHT WILL GENERALLY REMAIN DRY...HOWEVER THERE IS ANOTHER
WEAK VORT TRYING TO LIFT NORTHEAST ACROSS IOWA LATE SAT NGT/EARLY
SUN. WITH A SLIGHT WARM LAYER TRYING TO LIFT ACROSS THE
REGION...HOWEVER HAVE HELD ONTO MAINLY LGT SNOW. THERE IS SOME
CONCERN THAT TEMPS ALOFT COULD BE WARM ENOUGH TO FULLY MELT ANY
DENDRITES. THE OTHER CONCERN WORTH MENTIONING IS THAT THE LIFT/OMEGA
IS LACKING LATE SAT NGT...SO DROPLET SIZE COULD BE SMALL AND INSTEAD
OF ANY DENDRITES THERE COULD END UP BEING PATCHY FREEZING
DRIZZLE...MAINLY AFTER MIDNIGHT.
BEACHLER
&&
.LONG TERM...
237 PM CST
SUNDAY THROUGH SATURDAY...
500MB TROUGH WILL BEGIN TO DIG SOUTH ACROSS THE CENTRAL CONUS SUN
INTO MON...WITH A SERIES OF MID-LVL VORTS PROGGED TO SLIDE SOUTHEAST
ACROSS THE CANADIAN ROCKIES INTO THE NORTHERN PLAINS. THE MAIN FOCUS
WILL BE ON A STRONGER SHORTWAVE DEVELOPING SUN NGT/EARLY MON ACROSS
THE DAKOTAS...EXPECTED TO SLIDE SOUTHEAST ACROSS NORTHERN IL.
ALTHOUGH CONFIDENCE IN THE TIMING/PLACEMENT OF THIS PATH IS LOW
GIVEN CONTINUED CORRECTIONS BASED ON THE LATEST GUIDANCE CYCLES.
MOISTURE WILL BE ADVECTING NORTH OF THIS LOW MON...WITH PRECIP
ARRIVING MON MORNING LIKELY AS MAINLY RAIN OR PERHAPS A RAIN/SNOW
MIX ACROSS THE NORTHERN CWFA. THEN A QUICK PUSH OF MUCH WARMER AIR
WILL BRING TEMPS INTO THE UPR 30S/NEAR 40 MON AFTN AND SHOULD TURN
ANY PRECIP TO PLAIN RAIN. AS MON NGT PROGRESSES...THE LOW IS PROGGED
TO STEADILY DEEPEN AND LIFT NORTHEAST ACROSS NORTHERN IL EARLY TUE.
FROPA CURRENTLY PROGGED FOR TUE EVE...BRINGING COLDER AIR BACK INTO
THE FORECAST AREA AND TURNING RAIN OVER TO LGT SNOW.
MON NGT WITH THE WARM AIR STEADILY ADVECTING NORTH...TEMPS WILL
REMAIN IN THE MID/UPR 30S. TUE TEMPS COULD PUSH EVEN
WARMER...DEPENDING ON THE PLACEMENT/TIMING OF FROPA. CURRENT
INDICATIONS ARE THAT TEMPS WILL PUSH INTO THE LOW/MID 40S TUE AFTN.
CHRISTMAS EVE THROUGH CHRISTMAS DAY...
ENSEMBLES ALONG WITH OPERATIONAL SOLUTIONS HAVE BEEN TARGETING THE
SYSTEM BECOMING WRAPPED UP OVER THE GREAT LAKES REGION AND POSSIBLY
TRANSITIONING INTO ANOTHER LOW OVER SOUTHERN ONTARIO/SOUTHWEST
QUEBEC CHRISTMAS DAY. A TIGHT GRADIENT WILL REMAIN OVER THE REGION
BOTH CHRISTMAS EVE/CHRISTMAS DAY...WITH TEMPS RETURNING TO MORE
SEASONAL CONDITIONS IN THE LOW/MID 30S.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* MVFR CEILINGS LIKELY BECOMING VFR BEFORE SUNRISE. EXPECTED TO
LOWER TO MVFR AGAIN THIS EVENING.
* LIGHT/VARIABLE WINDS BECOMING LIGHT SOUTH-SOUTHWEST BY MIDDAY.
RATZER
//DISCUSSION...UPDATED 06Z...
WEAK SURFACE HIGH PRESSURE RIDGE MOVING SLOWLY EAST ACROSS THE
AREA THIS MORNING. CALM OR LIGHT/VARIABLE WINDS AND MVFR CLOUDS
TRAPPED BENEATH SHALLOW INVERSION PERSISTING. SURFACE OBS INDICATE
MVFR CEILINGS ERODING FROM THE SOUTHWEST HOWEVER...WITH THE
POTENTIAL FOR CONDITIONS TO BECOME VFR AT TAF SITES DURING THE
PRE-DAWN HOURS. QUESTION IS HOW LONG VFR LASTS...AS EXTENSIVE AREA
OF MVFR/IFR CEILINGS WEST OF THE MISSISSIPPI RIVER WILL EVENTUALLY
SPREAD INTO THE AREA TONIGHT. KRFD BEING FARTHER WEST LOOKS TO BE
BACK INTO MVFR CONDITIONS PERHAPS AS EARLY AS MID-LATE MORNING.
CEILINGS WILL LIKELY LOWER INTO IFR RANGE LATE THIS EVENING INTO
EARLY SUNDAY...WITH THE POTENTIAL FOR SOME FLURRIES OR FREEZING
DRIZZLE DEVELOPING SUNDAY MORNING.
CALM OR LIGHT/VARIABLE WINDS LESS THAN 5 KT WILL BECOME SOUTH-
SOUTHWEST AT 5 KT BY EARLY AFTERNOON AND REMAIN LIGHT SOUTH
THROUGH TONIGHT.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM IN CEILING TRENDS AND VFR DURATION TODAY.
* HIGH IN WIND TRENDS.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...MVFR CIGS. SOUTH WINDS.
MONDAY...MVFR CIGS. BRIEF PERIOD OF RAIN OR MIXED RAIN AND SNOW.
TUESDAY...MVFR CIGS. CHANCE OF RAIN.
WEDNESDAY...MVFR CIGS. BLUSTERY - GUSTY WEST WINDS. CHANCE OF
SNOW.
THURSDAY...VFR.
ED F
&&
.MARINE...
200 PM CST
HIGH PRESSURE IS OVER THE REGION AND IT WILL SLOWLY SHIFT EAST
THROUGH SUNDAY NIGHT. LIGHT WINDS BECOME SOUTHWEST OVERNIGHT. THE
NEXT LOW MOVES OVER THE DAKOTAS SUNDAY NIGHT WITH SOUTH WINDS
INCREASING TO 30 KT. MODELS DISAGREE WITH EXACT PATH OF THIS LOW.
ONE HAS THE LOW DEEPENING OVER LAKE SUPERIOR WEDNESDAY WHILE ANOTHER
HAS THE LOW DEEPENING OVER LAKE ERIE. SOUTHEAST WINDS AROUND 25 KT
ARE EXPECTED THROUGH MONDAY NIGHT AHEAD OF THE LOW...THEN WINDS
BECOME WEST BEHIND IT. FOR SPEEDS WENT MIDDLE OF THE ROAD GIVEN THE
VARIABILITY. COULD DEFINITELY SEE HIGHER GUSTS IF THE LOW DEEPENS
CLOSER TO THE LAKE.
MODELS AGREE ON VERY STRONG WINDS BEHIND THE LOW WEDNESDAY NIGHT
THROUGH THURSDAY. HAVE HIGH END GALES IN THE FORECAST AND SOME
GUIDANCE MEMBERS SUGGEST LOW END STORM FORCE GUSTS MAY BE POSSIBLE.
DO NOT HAVE THE CONFIDENCE TO GO THAT HIGH JUST YET...BUT HAVE HIGH
CONFIDENCE IN AT LEAST GALES. THE LOW SHIFTS NORTHEAST WITH WINDS
DIMINISHING THURSDAY NIGHT. THE NEXT LOW HOWEVER MOVES OVER THE
SOUTHERN PLAINS THURSDAY EVENING.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1135 PM CST Fri Dec 19 2014
.UPDATE...
ISSUED AT 905 PM CST FRI DEC 19 2014
The surface ridge axis is finally making some progress to the east
of Illinois, allowing winds west of I-55 to start a trend out of
the southeast. A weak shortwave passing across southern IL could
trigger some light snow showers or flurries southeast of I-70.
Radar returns toward Lawrenceville are mostly virga, with no snow
reaching the ground yet. Cloud heights are lowering with time
under that wave, so some flurries were added to the forecast for
the far southeast counties toward midnight.
The next area of concern is NW of the IL river, where low clouds
and fog may develop into some freezing drizzle toward sunrise. The
precip could fall as flurries, but a lack of ice crystals to feed
into the low cloud layer will limit the ability for snowflakes to
develop. Thus, the concern for FZDZ to occur. Any icing would
cause slippery travel conditions. Have added a mention of FZDZ
between 12z-15z Sat morn, but may need a mention even earlier
depending on speed of saturation and progression of shortwave from
Nebraska across Iowa/N MO.
Low temps will not drop off appreciably from current temps due to
increasing clouds. Updates this evening were to the weather and
sky grids to match expected trends.
&&
.SHORT TERM...(Tonight)
ISSUED AT 328 PM CST FRI DEC 19 2014
20z/2pm visible satellite imagery continues to show a large break in
the overcast extending from southeast Iowa across much of central
Illinois into Kentucky. With high pressure directly overhead and
only very light low-level winds, partly to mostly clear conditions
will persist through the evening hours. As the high begins to shift
eastward, a southerly return flow will gradually develop late
tonight into Saturday, allowing the low clouds currently across
Iowa/Missouri to spill back into the area. End result will be a
mostly clear start to the night, with overcast conditions expected
across the board by dawn Saturday. May also see some patchy fog
west of the I-55 corridor late tonight as low-level moisture
increases, but am not expecting any major restrictions to
visibility. Due to the initially mostly clear skies and light
winds, another cold night is expected with low temperatures
bottoming out in the lower to middle 20s.
&&
.LONG TERM...(Saturday through Friday)
ISSUED AT 328 PM CST FRI DEC 19 2014
A rather quiet weekend is on tap across central and southeast
Illinois, but weather activity will be on the upswing heading into
the Holiday work week.
Model agreement is good through the weekend with mostly neutral
upper-level flow and high pressure expected to be the dominant
player at the surface. A week wave, currently pushing east across
the central Plains, will cross the area early Saturday. However, the
forcing appears too weak, and moisture depth too shallow, to warrant
a mention of any precipitation.
A strong, slow moving system will impact the area from Monday into
Christmas Eve. We will remain on the warm side of the system through
Tuesday, with all precipitation initially expected to fall in the
form of rain. Temperatures ahead of the system will also average
nearly 10 degrees above normal for late December.
The colder air on the back side of the deepening storm system will
arrive for Tuesday night into Christmas Eve. This would support any
remaining precipitation changing over to snow. At this point, the
threat for significant snowfall on the back side of the system seems
low, but some light snow accumulation is likely. The model
agreement/run-to-run consistency is still a little shaky heading
into midweek, so future model trends will need to be monitored very
closely.
Another system is progged to arrive by late in the week, generally
Friday into Saturday. However, model consistency with this system is
poorer than the first, so confidence in the ultimate outcome is not
very high.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
ISSUED AT 1118 PM CST FRI DEC 19 2014
VFR conditions will begin the TAF period for most of the TAF
sites...with the exception being CMI where MVFR VIS is already in
place. Some of the issues with the TAFs tonight are the timing of
MVFR VIS and lowering CIGs. The surface high that was over
Illinois earlier is slowly pushing east with light to calm winds
remaining over much of central Illinois. Winds are also slowly
shifting to the east southeast allowing the low level moisture to
filter in both from the east and the west. Locations over Missouri
and Indiana have MVFR VIS and CIGs with locations in Missouri
under IFR CIGs. Given the complexity involved with timing of lower
VIS and CIGs...confidence is fairly low in the TAF forecast past
the first 6 hours. Currently have MVFR conditions over PIA
starting at 09Z...at 08Z for BMI and DEC...and at 12Z for SPI.
Mainly went with the HRRR since it seemed to have a pretty good
handle on the previous forecast. Also included a TEMPO group for
CMI as all guidance had IFR VIS over the site between 09Z and 13Z.
Only included a TEMPO for now since confidence in the timing is
lower. VFR conditions could resume around 16Z for the sites after
the next upper level wave moves through Illinois...but this could
change with the next TAF issuance.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...Barnes
LONG TERM...Bak
AVIATION...ALW
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
359 AM CST SAT DEC 20 2014
...UPDATED FOR SHORT TERM DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM CST SAT DEC 20 2014
WEAK SHORTWAVE TROUGHS ARE PERIODICALLY PROGRESSING ACROSS THE
PLAINS FROM THE WEST. ONE SUCH MINOR WAVE WILL MOVE ACROSS THE
SOUTHERN PLAINS BY TONIGHT. HOWEVER, LEE TROUGHING IN RESPONSE TO
WESTERLY FLOW AT MID LEVELS SEEMS TO BE THE DOMINANT FEATURE THAT
IS AFFECTING THE LOW LEVEL WIND FIELD. EARLY MORNING SATELLITE AND
SURFACE OBSERVATIONS INDICATE LOW STRATUS ACROSS THE SOUTHERN
PLAINS AS FAR NORTH AS PERRYTON AND MEDICINE LODGE. AS SURFACE
TROUGHING ENCOURAGES SOUTHERLY WINDS TODAY, THIS LOW LEVEL
MOISTURE SHOULD PROGRESS NORTHWARD INTO LOCATIONS FROM DODGE CITY
SOUTH AND EAST TO THE OKLAHOMA BORDER. THE NAM HAS A CHARACTERISTIC
BIAS OF BEING TOO DRY AND WARM AT LOWER LEVELS IN CASES SUCH AS
THIS. THE HRRR AND RAP ARE COOLER AND INDICATE LOW CLOUD COVER
PROGRESSING AS FAR NORTH AS DODGE CITY BY EARLY AFTERNOON. CLOUD
COVER WILL TEND TO KEEP DIURNAL RANGES LOWER AND TEMPERATURES
COOLER IN THE AFTERNOON. AS AN EXAMPLE, THE TEMPERATURE AT GAGE,
OKLAHOMA STAYED 41F FROM FRIDAY AFTERNOON THROUGH EARLY THIS
MORNING AS A RESULT OF THE STRATUS. TEMPERATURES SHOULD BE WARMER
TODAY IN LOCATIONS SUCH AS SCOTT CITY AND WAKEENEY WHERE PLENTY OF
SUNSHINE IS EXPECTED. LOW STRATUS WILL PERSIST OR INCREASE IN
AREAL COVERAGE TONIGHT, AND FOG IS POSSIBLE ON THE WESTERN
PERIPHERY OF THE CLOULD SHIELD, SOME OF WHICH COULD BE LOCALLY
DENSE. THE CLOUD COVER AND HIGHER DEWPOINTS OUGHT TO KEEP
TEMPERATURES FROM FALLING A LOT TONIGHT, EXCEPT FOR WEST CENTRAL
KANSAS WHERE LESS CLOUD COVER IS EXPECTED.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 220 PM CST FRI DEC 19 2014
MEDIUM RANGE MODELS INDICATE AN OPEN UPPER LEVEL SHORTWAVE TROUGH
TRANSITIONING EASTWARD ACROSS THE CENTRAL PLAINS SUNDAY GIVING WAY
TO A NORTHWESTERLY FLOW ALOFT ACROSS THE WESTERN HIGH PLAINS BY
SUNDAY NIGHT. HOWEVER, WITH A WEAK FLOW ALOFT A LITTLE LOW/MID LEVEL
MOISTURE AVAILABLE, DRIER CONDITIONS WILL PREVAIL ACROSS WESTERN
KANSAS THROUGH SUNDAY EVENING. PRECIP CHANCES PICK UP A LITTLE EARLY
MONDAY AS A SERIES OF H5 VORT MAXIMA BEGIN TO DIG SOUTHEASTWARD OUT
OF THE NORTHERN ROCKIES INTO THE WESTERN HIGH PLAINS. MEANWHILE, AN
ASSOCIATED COLD FRONT IS PROJECTED TO PUSH INTO WESTERN KANSAS
MONDAY MORNING PROVIDING A POTENTIAL FOCUS FOR PRECIP INITIATION.
ALTHOUGH LIMITED MOISTURE AND A WEAKER FLOW ALOFT WILL LIMIT
SIGNIFICANT PRECIP CHANCES, A SLIGHT CHANCE FOR RAIN , ESPECIALLY
ACROSS EXTREME SOUTHWEST KANSAS WHERE SOME PROXIMITY TO A STRONG
UPPER LEVEL JET DIGGING ACROSS THE ROCKIES MAY BE FELT. DRY
CONDITIONS RETURN TUESDAY AS A DEVELOPING DOWNSLOPE FLOW ACROSS
WESTERN KANSAS DRAWS MUCH DRIER AIR INTO THE REGION.
ABOVE NORMAL TEMPERATURES ARE EXPECTED SUNDAY AS A LEE SIDE TROUGH
OF LOW PRESSURE DEVELOPS AND STRENGTHENS ACROSS EASTERN COLORADO.
THIS WILL SET UP A SOUTH TO SOUTHWESTERLY FLOW ACROSS WESTERN KANSAS
ENHANCING WARM AIR ADVECTION INTO THE AREA WITH H85 TEMPERATURES
CLIMBING TO A LITTLE ABOVE 5C ACROSS CENTRAL AND SOUTHWEST KANSAS.
ALONG WITH DECREASED CLOUD COVER, LOOK FOR HIGHS UP INTO THE 50S(F)
ACROSS MUCH OF THE AREA SUNDAY AFTERNOON. SIMILAR TEMPERATURES ARE
LIKELY MONDAY EVEN AS A WEAK COLD FRONT PUSHES THROUGH WESTERN
KANSAS BY MONDAY AFTERNOON. THE DELAYED ARRIVAL OF COLDER AIR BEHIND
THE FRONTAL PASSAGE WILL LOWER HIGHS BACK DOWN INTO THE 40S(F) ON
TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1155 PM CST FRI DEC 19 2014
WEAK SURFACE LEE TROUGHING WILL PERSIST THROUGH THE PERIOD ON THE
HIGH PLAINS. LIGHT SOUTHWESTERLY WINDS AT 5 TO 10 KTS WILL
CONTINUE THROUGH THE TAF PERIOD BEFORE BECOMING MORE SOUTHERLY
AFTER 18Z SATURDAY. MVFR TO VFR CONDITIONS WILL PERSIST THROUGH
12Z BEFORE BECOMING VFR WITH DAYTIME HEATING BY 14-15Z. THERE IS A
CHANCE THAT STRATUS OVER THE TEXAS PANHANDLE COULD PROGRESS INTO
KDDC BY 18-19Z, WITH CIGS IN THE LOW MVFR CATEGORY GIVEN THE
SOUTHERLY WINDS TODAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 52 33 52 34 / 0 0 0 10
GCK 52 27 55 32 / 0 0 0 10
EHA 51 27 57 34 / 0 0 0 20
LBL 52 31 56 33 / 0 0 0 10
HYS 52 31 50 34 / 0 0 0 10
P28 52 37 49 36 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...FINCH
LONG TERM...JJOHNSON
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
435 AM EST SAT DEC 20 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 434 AM EST SAT DEC 20 2014
WV LOOP AND 00Z RAOBS SHOW A LARGE SCALE ZONAL FLOW...BUT THERE IS
EMBEDDED AMPLIFICATION. TROUGHING WAS AS CLOSE BY AS NORTHERN PLAINS
AND MINNESOTA THIS MORNING. PRIMARY PV ANAMOLIES/SHORTWAVES WITHIN
TROUGH WERE OVER FAR NORTHWEST ONTARIO AND OVER WESTERN IOWA. WEAK
SFC TROUGH NOTED OVER WESTERN MINNESOTA TOO...WHILE SFC RIDGING
EXTENDING OUT OF QUEBEC WAS STILL MAIN FEATURE OVER GREAT LAKES. THE
ONTARIO WAVE AND WEAK WARM AIR ADVECTION AHEAD OF THE MINNESOTA
TROUGH AND UPSLOPE LOW-LEVEL FLOW IS SUPPORTING LGT WINTRY MIX OF
SNOW AND FREEZING DRIZZLE OVER NORTHERN MINNESOTA THIS MORNING. ONLY
AFFECT FM ONTARIO SHORTWAVE OVER UPR MICHIGAN IS BATCH OF MID CLOUDS
OVER WEST HALF OF CWA. NO PRECIP THROUGH. ONLY WEATHER OF NOTE IN
THE CWA THIS MORNING IS PATCHY DENSE FOG OVER CNTRL CWA...VCNTY OF
IMT TO SAW.
ONTARIO WAVE MOVES LITTLE EASTWARD TODAY AS ANOTHER SHORTWAVE
CURRENTLY OVER MT TRIES TO CATCH UP WITH IT. THUS...SFC TROUGH AND
WARM AIR ADVECTION STAY MAINLY OVER MN. RAP SHOWS WEAK LIFT TRYING
TO IMPACT KEWEENAW THIS MORNING INTO EARLY AFTN...BUT IT LOOKS MUCH
DRIER THAN IT IS UPSTREAM OVER MN WHERE PRECIP IN OCCURRING THIS
MORNING...SO NOT EXPECTING ANY PRECIP OUT OF THIS FOR OUR AREA. LOW
CLOUDS OVER NW WI AND WEST UPR MICHIGAN GRADUALLY EASE
EASTWARD...BUT A FEW SPOTS IN EAST HALF OF CWA MAY STAY CLEAR OF THE
LOW CLOUDS ALL DAY. TOUGH TO SAY EXACTLY WHERE THOUGH AS THERE ARE
DIFFERENT AREAS OF CLOUDS AFFECTING THE AREA AND MODELS FORECASTING
OF THEM IS ONLY FAIR. FOR TEMPS...WENT AT OR 1-2 DEGREES ABOVE
FRIDAY READINGS AS 925MB TEMPS WARM SLIGHTLY COMPARED TO FRIDAY.
WHERE SUNSHINE CAN PERSIST INTO THE AFTN...TEMPS COULD BUMP INTO THE
MID 30S. BEST SHOT AT THAT WOULD BE EAST CENTRAL CWA...VCTY OF
MUNISING AND GRAND MARAIS. FARTHER WEST...CLOUDS WILL HOLD TEMPS
DOWN OVER INTERIOR WEST TO UPR 20S. INTO THIS EVENING...EXPECT LOW
CLOUDS /HIGHER 925MB-850MB RH/ TO BE OVER WEST HALF OF CWA AND ALSO
THE FAR EAST CWA. EVENTUALLY THOUGH...CLOUDS SHOULD FILL IN OVER ALL
CWA. UNTIL THAT OCCURS...TEMPS FOR INTERIOR CNTRL CWA OR AT LEAST
PORTIONS OF THESE AREAS MAY DROP OFF QUICKLY. CLOSEST MODEL TO
INCICATE THAT WAS BIAS CORRECTED NAM MOS. TWEAKED DOWN EVEN FURTHER
THOUGH /LOW TEENS/ SEEING HOW MUCH TEMPS FELL EARLY THIS MORNING
WHERE SKIES WERE CLEAR. ALSO WILL ADD FOG TO THOSE AREAS SINCE THESE
TEMPS WILL BE WELL BELOW THE EXPECTED AFTN DWPNTS. WHERE CLOUDS STAY
IN ALL NIGHT...MIN TEMPS LIKELY STAY ABOVE 20 DEGREES.
SOUNDINGS FM NAM AND GFS INDICATE INCREASING SUB 950MB MOISTURE
LATE TONIGHT FM THE SOUTH AND WITH UPSLOPE SOUTH FLOW OVER CNTRL
CWA COULD SEE PATCHY FREEZING DRIZZLE IMT TO NEGAUNEE. NOT MUCH UVM
SHOWN ON THE SOUNDINGS THOUGH...SO LEFT IT OUT OF GRIDS ATTM.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 434 AM EST SAT DEC 20 2014
MAIN FOCUS FOR THE LONGER TERM REMAINS THE POTENTIAL FOR SOME SN OR
MIXED PCPN IN THE MON INTO XMAS PERIOD ASSOCIATED WITH A DEEPENING
UPR TROF IN THE CENTRAL CONUS AS A SERIES OF SHRTWVS RIDING OVER A
MEAN RDG ALONG THE W COAST DIG INTO THE PLAINS. THE STRONGEST OF
THESE DISTURBANCE IS NOW OVER THE NE PACIFIC OCEAN. ALTHOUGH THE
MODELS ARE COMING INTO BETTER AGREEMENT ON WARMER LLVL TEMPS IN THE
TUE/WED TIME AND ON THE DEVELOPMENT OF A LO PRES IN THE LO/MID MS
RIVER VALLEY THAT WL TRACK SOMEWHERE NEAR THE CENTRAL GREAT LKS ON
WED AND INTO CANADA ON XMAS DAY...THERE ARE STILL SOME SIGNIFICANT
DIFFERENCES ON THE DETAILS OF HOW THE INTERACTION/PHASING BTWN THESE
SEPARATE DISTURBANCES THAT ARE STILL OVER THE DATA POOR PACIFIC WL
IMPACT THE SFC LO TRACK AND UPR MI.
SUN/SUN NIGHT...AS LLVL S WIND BTWN DEPARTING HI PRES IN SE CANADA
AND FALLING MSLP TO THE W ADVECT MOISTER LLVL AIR INTO THE CWA...
OPTED TO INCLUCE SOME FREEZING DZ OVER THE SCENTRAL IN THE MRNG
WHERE LLVL WIND WL UPSLOPE OFF LK MI. THEN OPERATIONAL MODELS SHOW A
SHRTWV MOVING E FM THE NRN PLAINS ACROSS THE NW GREAT LKS AND INTO
NW ONTARIO BY 12Z MON... BRINGING A PERIOD OF DEEP LYR QVECTOR CNVGC
ASSOCIATED WITH SOME DPVA AND ISENTROPIC ASCENT BEST DEPICTED ON THE
285-290K SFCS /ABOUT H85-75/ IN THE STRONGER SSW FLOW BTWN HI PRES
OVER THE CNDN MARITIMES AND LO PRES IN THE NRN PLAINS. ARRIVAL OF
THE DEEPER MSTR SHOULD END THE FREEZING DZ. THE BULK OF THE GUIDANCE
INDICATES THE ACCOMPANYING SN WL BEGIN OVER THE SCENTRAL SUN AFTN
AND THEN OVERSPREAD THE REST OF THE FA THRU SUN NGT. THE NAM SHOWS
THE HIEST QPF UP TO 0.25-0.30 INCH OVER THE SCENTRAL...WHERE THE
NEAR SFC SSE FLOW WL UPSLOPE OFF LK MI AND H85 MSTR CNVGC IS A BIT
SHARPER. THE GFS ON THE OTHER HAND SHIFTS THE HIER QPF TO OVER THE
NW CWA LATE AT NGT. GIVEN THE GREATER CONSISTENCY OF THE NAM WITH
PREVIOUS FCST GUIDANCE...TENDED TOWARD THAT MODEL SCENARIO. WL BUMP
POPS UP TO LIKELY OVER THE SCENTRAL CENTERED ARND SUN EVNG WHEN THE
FORCING WL BE GREATEST. THERE COULD BE A FEW INCHES OF SN ACCUM IN
THIS AREA AS WELL. SSW FLOW UP THE LENGTH OF LK MI MAY SUPPORT SOME
HIER POPS OVER THE E...BUT MARGINAL CHILL OF THE AIRMASS FOR LK
ENHANCEMENT WITH H85 TEMPS RISING TO -5C BY 00Z MON SHOULD LIMIT THE
POTENTIAL FOR A SGNFT IMPACT. TEMPS WL REMAIN ABOVE NORMAL...
ESPECIALLY ON SUN NGT WITH CLD COVER AND A STEADY S WIND GREATLY
LIMITING THE DIURNAL TEMP FALL.
MON...FOLLOWING THE EXIT OF THE SHRTWV INTO NW ONTARIO ON MON AND
THE ARRIVAL OF SOME MID LVL DRYING ASSOCIATED WITH A SHRTWV RDG AXIS
ROTATING NEWD THRU THE NW GREAT LKS TO THE E OF THE DEEPENING UPR
TROF IN THE PLAINS...EXPECT DIMINISHED POPS. BUT PERSISTENT WAA IN
THE DEEP S FLOW BTWN LO PRES SLIDING SEWD THRU THE NRN PLAINS AND HI
PRES OVER THE CNDN MARITIMES WL CAUSE LOTS OF CLDS AND CONTINUED LO
CHC POPS. AS THE LLVLS WARM INTO THE 30S ESPECIALLY NEAR THE WARMING
INFLUENCE OF THE GREAT LKS...LIGHT PCPN MAY INCLUDE A MIX OF RA AND
SN.
MON NGT/TUE...THE 00Z GFS REMAINS CONSISTENT ON SHOWING A CLOSED H5
LO WITHIN THE DEEPENING CENTRAL CONUS TROF/DEEPER SFC LO PRES MOVING
INTO THE UPR LKS DURING THIS TIME ALONG WITH HIER H85 TEMPS UP TO
ARND 0C. THE 12Z/00Z ECMWF MODELS ON THE OTHER HAND HOLD THE CLOSED
H5 LO/SFC LO FARTHER TO THE SW...WITH A SLOWER ARRIVAL OF DEEPER
MSTR AND LOWER H85 TEMPS. BOTH MODELS SHOW DISTURBANCES DIGGING SEWD
TO THE E OF THE UPR RDG ACROSS THE W DEEPENING THE PLAINS TROF.
SINCE THIS GREATER FORCING INTO THE SRN PLAINS SHOULD TEND TO HOLD
THE CLOSED LO THE SW...WL TEND TOWARD THE 12Z ECMWF SCENARIO. THIS
MODEL SHOWS DEEPER MSTR ARRIVING LATE MON NGT AND PERSISTING THRU
TUE AS THE WEAKER SHRTWV LIFTS NEWD AWAY FM CLOSED LO TO THE SW.
ALTHOUGH THE 00Z ECMWF H85 TEMPS ARE LOWER THAN FCST BY THE GFS...
THE FCST H100-85 THKNS IS ONLY A BIT LOWER THAN THE GFS FCST. A LOOK
AT THE 00Z ECMWF FCST SDNGS SHOW A TREND TOWARD A WARMER NEAR SFC
LYR THAT WOULD SUPPORT MORE RA...AS SHOWN BY RECENT GFS RUNS. SO
TENDED TO RAISE FCST TEMPS AND INCLUDE A GREATER AREA OF AT LEAST A
MIX WITH RA. THE FCST SDNGS FM NEITHER MODEL SHOW AN ELEVATED WARM
LYR...SO THE PCPN SHOULD BE RA OR SN. ADDED A MENTION OF SOME FOG
DURING THE MON NIGHT/TUE TIME TO REFLECT THE RA/HIER TEMPS AND
DEWPTS OVER A MELTING SN PACK AT MANY LOCATIONS THAT UPSLOPE OFF LK
MI IN THE EXPECTED LLVL SE FLOW. THIS MIXED PCPN WL TEND TO DIMINISH
ON TUE NGT AS SOME UPR DRYING FOLLOWS THE SHRTWV EXITING NNEWD INTO
ONTARIO.
WED/THU...THE LONGER RANGE MODELS ARE BEGINNING TO COME INTO BETTER
AGREEMENT ON SHOWING A SECOND LO DVLPG IN THE LOWER TO MID MS RIVER
VALLEY ON TUE AT THE SRN END OF THE DEEPING CENTRAL CONUS TROF AND
THEN MOVING NNE INTO THE CENTRAL GREAT LKS ON WED AND THEN INTO ERN
ONTARIO ON XMAS DAY WHILE DEEPENING SIGNIFICANTLY AS THE UPR TROF
TAKES ON A MORE NEGATIVE TILT. NOT SURPRISINGLY...THE EXACT TRACK OF
THE SFC LO...WHICH WL MAKE A SGNFT DIFFERNCE ON PTYPE/PCPN TOTALS
OVER UPR MI...IS STILL UNCERTAIN. THE 00Z GFS INDICATES A FARTHER W
TRACK ACROSS THE ERN U.P. THAN THE 00Z ECMWF/UKMET RUNS...BUT THE
GFS INDICATES THE PCPN WOULD BE HEAVY SN OVER THE W HALF OF UPR MI.
THE FARTHER E ECMWF MODEL GENERATES MUCH LIGHT PCPN OVER THE E.
CONSIDERING THE SGNFT DIFFERNCES THAT REMAIN...RELIED ON THE MODEL
CONSENSUS FOR THE FCST DETAILS. THIS CONSENSUS SUPPORTS HIER POPS
OVER THE E WITH A CHANGE IN PTYPE FM MIXED RA/SN TO MAINLY SN AS THE
INCREASING N BACKING NW WINDS ADVECT COLDER AIR INTO THE CWA.
IN THE WAKE OF THE DEEPENING LO MOVING INTO ONTARIO ON XMAS DAY...
THE PRES GRADIENT IS PROGGED TO TIGTHEN SGNFTLY AND H925 WINDS
INCREASE TO NEAR 45 KTS. NW WIND GUSTS MAY AT LEAST APRCH ADVY
CRITERIA...ESPECIALLY AT EXPOSED LOCATIONS NEAR LK SUP.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1239 AM EST SAT DEC 20 2014
LOW CLOUD FCST MAY BE TRICKY TONIGHT AT KSAW AS LATEST SATELLITE
IMAGERY REVEALS AN AREA OF CLEARING OVER CNTRL UPPER MI. ALSO SEEING
FOG DEVELOP IN LAST HR THERE AS WELL...SO AS LONG AS SKIES STAY
CLEAR...WILL HAVE FOG ISSUES. DUE TO THE BKN MID CLOUDS LURKING
JUST TO THE WEST OF KSAW AND INCREASING HIGH CLOUDS...HAVE FEELING
THAT FOG WILL BE IN AND OUT AND NOT A PREVAILING CONDITION SO JUST
INCLUDED IN TEMPO. MODEL GUIDANCE SUGGESTS THAT KSAW COULD STAY CLR
OF BKN-OVC LOW CLOUDS THROUGH THE MORNING HRS BEFORE CLOUDING BACK
UP AGAIN WITH AN MVFR DECK BY THIS AFTN.
FOR THE WESTERN TAF SITES...EXPECT LOW CLOUDS TO PERSIST THROUGH
MUCH OF PD AS WARM AIR AND MOISTURE ADVECTION CONTINUES TO ADVECT
OVER AREA BETWEEN A HIGH PRESSURE SYSTEM TO THE EAST AND A TROUGH
OVER THE NORTHERN PLAINS. ONLY EXCEPTION WILL BE EARLY ON AT KCMX
WHERE ONLY MID CLOUDS ARE NOTED TO START THIS TAF PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 434 AM EST SAT DEC 20 2014
EXPECT S WINDS UNDER 20 KTS ASSOCIATED WITH HI PRES DRIFTING E THRU
SE CANADA TO PERSIST INTO SUN. THE S WINDS WILL INCREASE UP TO 25
KTS OVER AT LEAST THE E HALF OF THE LAKE ON SUN INTO MON AS A LO
PRES TRACKS E THRU THE NORTHERN PLAINS AND THE PRES GRADIENT
TIGHTENS OVER THE UPPER LAKES. AS ANOTHER LO PRES DEVELOPS TO THE S
ON TUE...THE FLOW WILL TEND TO BACK TOWARD THE NW. THE LATEST TRENDS
INDICATE THIS LO WILL DEEPEN SIGNFICANTLY AS IT MOVES TO THE NNE
THRU THE CENTRAL GREAT LAKES ON WED AND INTO SE ONTARIO ON XMAS DAY.
THE POTENTIAL FOR A N VEERING NW GALE EVENT FROM LATE ON WED THRU
XMAS DAY NOW LOOKS GREATER.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...KC
AVIATION...JLA
MARINE...KC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1209 AM CST SAT DEC 20 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 238 PM CST FRI DEC 19 2014
SATELLITE AND OBSERVATIONS SHOW THE EDGE OF THE LOW CLOUDS IN THE
FAR WESTERN PART OF THE FORECAST AREA. FOG HAS BEEN PERSISTENT NEAR
THE EDGE OF THE LOW CLOUDS. VISIBILITIES HAVE IMPROVED IN THE PAST
HOUR OR SO...BUT SOME LIGHT FOG PERSISTS.
WATCHING THE VERY SLOW PROGRESSION OF THE CLOUDS TO THE EAST HAVE
BEEN INCLINED TO KEEP THE CLOUDS LONGER THAN EARLIER THOUGHT. UNDER
THE CLOUDS THE WINDS ARE FROM THE SOUTH OR EVEN THE SOUTHEAST A BIT
AND THIS HAS MADE IT HARD FOR THE CLEARING LINE TO CONTINUE MOVING
TO THE EAST. ON THE OTHER HAND UNDER THE CLEAR SKIES THE WINDS ARE
FROM THE WEST AND SHOULD BE PUSHING DRIER AIR DOWN SLOPE WHICH
SHOULD HELP THE CLEARING. AT THIS TIME THE SOUTH WINDS SEEM TO BE
WINNING THAT BATTLE.
TWO MAIN QUESTIONS REMAIN FOR THE FORECAST. FIRST HOW FAR EAST WILL
THE CLOUDS MOVE AND SECOND WHETHER THERE WILL BE FOG NEAR THE EDGE
OF THE STRATUS. A BROAD SURFACE TROUGH JUST TO THE WEST OF THE
FORECAST AREA WILL MOVE TO THE EAST DURING THE NIGHT. THIS SHOULD
HELP WINDS TO TURN TO THE WEST EVEN THOUGH THEY SHOULD BE LIGHT.
EXPECT THAT THE WEST WINDS WILL HELP TO PUSH THE CLOUDS TO THE EAST
A LITTLE DURING THE NIGHT. CLOUDS SHOULD HOLD TOUGH IN THE
EAST...BUT THE WEST ESPECIALLY AND EVEN THE CENTRAL PART OF THE
FORECAST AREA COULD SEE SOME CLEARING DURING THE NIGHT. THAT BRINGS
WITH IT THE COOLING TEMPERATURES THAT HAVE BEEN EVIDENT IN THE WEST
DURING THE MORNING TODAY. COOLER TEMPERATURES AND LIGHT WINDS SHOULD
ALLOW FOR SOME FOG ACROSS THE AREA. HOW MUCH...WHERE AND HOW LOW
WILL BE VISIBILITY BE ARE ALL QUESTIONS THAT PROVIDE A CHALLENGE.
SINCE MANY LOCATIONS ACROSS THE FORECAST AREA HAVE YET VISIBILITY OF
MORE THAN 5 MILES...WILL MAKE THE ASSUMPTION THAT THE LIGHT FOG
SHOULD LIFT A LITTLE THIS AFTERNOON...BUT RETURN DURING THE NIGHT.
HAVE KEPT PATCHY FOG ACROSS THE FORECAST AREA LATE TONIGHT. THE
LOWEST VISIBILITIES WILL BE NEAR THE EDGE OF THE CLOUDS. CURRENTLY
THE NAM AND HRRR ARE THE ONLY MODELS THAT INDICATE THERE WOULD BE
SOME FOG AROUND THE AREA. THE NAM KEEPS IT FURTHER TO THE EAST AND
FAIRLY LIGHT WHILE THE HRRR GIVES SOME LOWER VISIBILITIES FURTHER
WEST. WITH THE CURRENT FORECAST FOR WHERE THE CLEARING LINE WILL BE
LATE TONIGHT EXPECT THE LOWEST VISIBILITIES TO BE IN THE CENTRAL
PART OF THE FORECAST AREA BUT NOT SURE HOW LOW THE VISIBILITY WILL
BE...ALTHOUGH WITH THE PAST FEW NIGHTS AS A MODEL EXPECT THERE COULD
BE SOME VISIBILITIES LESS THAN A MILE SOMEWHERE.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 238 PM CST FRI DEC 19 2014
A PROGRESSIVE WEST NORTHWESTERLY FLOW IS EXPECTED TO BE IN PLACE
ACROSS THE REGION TO START THE EXTENDED PERIODS...WITH AN UPPER
LEVEL SHORTWAVE ACROSS THE PACIFIC NORTHWEST FORECAST TO DIVE INTO
THE PLAINS SUNDAY NIGHT THROUGH MONDAY. AS THIS DISTURBANCE DEEPENS
ACROSS THE MISSISSIPPI RIVER VALLEY AND TRACKS INTO THE GREAT LAKES
REGION...NORTHWESTERLY FLOW WILL PERSIST ALOFT...AND COULD SEE
ANOTHER UPPER LEVEL WAVE DIVE ACROSS THE LOCAL AREA TUESDAY NIGHT OR
WEDNESDAY. WHILE MODELS DISAGREE ON THE TIMING OF THIS NEXT
WAVE...THEY DIVERGE EVEN MORE AS WE TRANSITION INTO CHRISTMAS DAY
AND BEYOND...WITH THE EC STILL MAINTAINING A MUCH BROADER TROUGH
ACROSS THE WESTERN STATES AND THE GFS KEEPS THIS NEXT DISTURBANCE
MUCH FURTHER NORTH. DUE TO THE DIVERGENCE OF THE GUIDANCE...BLENDED
FORECAST DROPPED POPS FOR CHRISTMAS NIGHT AND THE DAY AFTER...AND
GIVEN THE UNCERTAINTY...SAW NO REASON TO TINKER WITH THE CHANCE OF
SNOW FOR THE TIME BEING.
STARTING OFF SUNDAY...EXPECT THE LOW LEVEL STRATUS THAT HAS BEEN
PERSISTENT ACROSS THE LOCAL AREA FOR MUCH OF THE LAST 10 DAYS TO BE
EAST OF THE LOCAL AREA AND CLOSER TO THE MISSOURI RIVER IN RESPONSE
TO A SURFACE TROUGH SLOWLY PUSHING ACROSS THE CENTRAL PLAINS. WITH
THE FOCUS OF SOME FOG ON THE WESTERN EDGE OF THIS STRATUS THE PAST
FEW DAYS...THINK IT IS PROBABLE THAT WE MIGHT STILL SEE SOME FOG
FROM ROUGHLY HIGHWAY 281 EASTWARD TO START THE DAY SUNDAY...CLOSER
TO THE EDGE OF THE STRATUS. AS A RESULT OF THIS...OPTED TO INTRODUCE
PATCHY FOG TO THE FORECAST FOR THIS AREA SUNDAY MORNING.
THEREAFTER...THE SURFACE FLOW IS EXPECT TO SHIFT AND BECOME MORE
WESTERLY THROUGH THE DAY SUNDAY...AND THIS DOWNSLOPING COMPONENT OF
THE WIND COMBINED WITH AT LEAST PARTLY SUNNY SKIES...SHOULD MAKE FOR
A RELATIVELY NICE FINISH TO THE WEEKEND...WITH TEMPERATURES EXPECTED
TO CLIMB INTO THE 40S SUNDAY AFTERNOON.
BEHIND THE SURFACE TROUGH...EXPECT THE NEXT UPPER LEVEL DISTURBANCE
TO SLIDE ACROSS THE LOCAL AREA LATE SUNDAY NIGHT INTO
MONDAY...BRINGING MAINLY THE CHANCE FOR RAIN TO THE LOCAL AREA.
BRIEFLY CONTEMPLATED INTRODUCING A RAIN SNOW MIX FOR THE EARLY
MORNING HOURS MONDAY GIVEN SURFACE TEMPS NEAR FREEZING...BUT LOOKING
AT THE ATMOSPHERIC PROFILE AND WARM LAYER ALOFT...THIS THE IS LIKELY
TO BE MAINLY A LIGHT RAIN EVENT FOR THE MAJORITY OF THE AREA. AS THE
MAIN UPPER LEVEL LOW MOVES INTO THE MISSISSIPPI RIVER VALLEY MONDAY
AFTERNOON...EXPECT SOME WRAP AROUND MOISTURE TO POTENTIALLY CLIP THE
NORTHERN AND EASTERN PORTIONS OF THE FORECAST AREA MONDAY NIGHT INTO
TUESDAY...WITH A LIGHT DUSTING OF SNOW POSSIBLE OVER THIS PERIOD. AS
THE FLOW REMAINS NORTHWESTERLY ALOFT BEHIND THE DEPARTING SYSTEM...A
SECONDARY UPPER LEVEL WAVE IS PROGGED TO CROSS THE NORTHERN AND
CENTRAL PLAINS TUESDAY NIGHT OR WEDNESDAY. DUE TO DIFFERENCES IN
GUIDANCE...THE CONFIDENCE OF ANY PRECIP OVER THIS PERIOD IS LOW AND
KEPT TEMPERATURES SEASONAL AND FORECAST DRY TUESDAY NIGHT THROUGH
CHRISTMAS DAY AS A RESULT.
THEREAFTER...WHAT LOOKED LIKE A DECENT CHANCE FOR SNOW LATE IN THE
EXTENDED PERIODS APPEARS A BIT MORE IN QUESTION THIS AFTERNOON AS
SIGNIFICANT DIFFERENCES IN THE HANDLING OF THE NEXT SYSTEM ARE
APPARENT. AS A RESULT...AS PREVIOUSLY MENTIONED...SAW NO REASON TO
DIVERGE FROM BLENDED FORECAST AS CONFIDENCE IN ANY ONE PARTICULAR
SOLUTION IS LOW THIS FAR OUT.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1209 AM CST SAT DEC 20 2014
LIFR TO VLIFR CONDITIONS TO START THE TAF PERIOD...WITH IMPROVING
CONDITIONS THEN EXPECTED DURING THE DAY SATURDAY.
A PERSISTENT STRATUS DECK CONTINUES ACROSS THE REGION...ALTHOUGH
THE WESTERN PERIPHERY OF THIS CLOUD DECK IS CURRENTLY LOCATED VERY
NEAR KEAR AND MOVING EAST. UNFORTUNATELY...AND AXIS OF DENSE FOG
HAS DEVELOPED ALONG AND JUST AHEAD OF THIS CLEARING LINE AND AS A
RESULT...SIGNIFICANT VISIBILITY RESTRICTION CONTINUES AT BOTH KEAR
AND KGRI. RECENT SATELLITE TRENDS AND GUIDANCE SUGGEST THIS
STRATUS SHIELD WILL SLOWLY DRIFT EAST THIS MORNING AND INTO THE
DAY SATURDAY...THUS ALLOWING FOR IMPROVING CONDITIONS DURING THE
SATURDAY. IN FACT...VFR CONDITIONS ARE CURRENTLY FORECAST AT KEAR
BY 12Z...AND AT KGRI BY 14Z. UNTIL THAT POINT HOWEVER...EXPECT THE
LIFR TO VLIFR CONDITIONS TO CONTINUE. THE SURFACE WIND WILL REMAIN
LIGHT AND VARIABLE TO START THE TAF PERIOD...BUT BECOME MORE
ESTABLISHED FROM THE SOUTH/SOUTHWEST DURING THE DAY SATURDAY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR NEZ039>041-
046>048-061>063-074>076-084>086.
KS...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR KSZ006-007.
&&
$$
SHORT TERM...JCB
LONG TERM...ROSSI
AVIATION...BRYANT
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
955 PM PST FRI DEC 19 2014
.SYNOPSIS...A WEAK SYSTEM WILL MOVE ACROSS THE AREA THROUGH SATURDAY
WITH JUST A FEW SHOWERS POSSIBLE IN THE SIERRA AND THE HIGHER
ELEVATIONS OF THE SOUTHERN GREAT BASIN. THE REMAINDER OF THE AREA
WILL SEE AN INCREASE IN HIGH CLOUDS. HIGH PRESSURE IS EXPECTED TO
STRENGTHEN OFF THE COAST OF CALIFORNIA ON SUNDAY AND HOLD THROUGH
TUESDAY KEEPING THE AREA DRY AND MILD. ANOTHER SYSTEM MAY IMPACT THE
AREA CHRISTMAS EVE INTO CHRISTMAS DAY.
&&
.UPDATE...ONCE AGAIN WE HAVE SOME VERY CLOSE TEMP-DEWPOINT SPREADS
AT THE SURFACE THIS EVENING ACROSS MOHAVE COUNTY WITH COLORADO CITY
SHOWING SATURATED CONDITIONS. WINDS ARE LIGHT AND THE LOW-LEVEL
MOISTURE IN PLACE IS NOT GOING TO GO ANYWHERE OVERNIGHT. THE MAIN
FACTOR AGAINST ANY FOG TONIGHT WOULD BE THE CIRRUS PASSING OVERHEAD.
OBSERVATIONS AROUND DAYBREAK FRIDAY (TODAY) SHOWED MAINLY A LOW
STRATUS DECK DEVELOPED. BUFKIT SOUNDINGS FROM THE RAP ARE NOT TOO
FAVORABLE FOR MUCH IN THE WAY OF FOG TONIGHT AT KINGMAN, BUT I
SUSPECT THAT WE COULD SEE AT LEAST A FEW PATCHES OF FOG OR LOW
STRATUS CLOUDS DEVELOP ESPECIALLY IN THE AREA IN AND AROUND COLORADO
CITY OVERNIGHT OR AFTER DAYBREAK SATURDAY. I WENT AHEAD AND ADJUSTED
THE GRIDS FOR THIS AS WELL AS ADJUSTED UP DEWPOINTS FOR TONIGHT
BASED ON THE LATEST OBSERVATIONS. THE REST OF THE FORECAST LOOKS ON
TRACK FOR NOW, ALTHOUGH SOME ADJUSTMENTS TO POPS MAY BE NEEDED FOR
SATURDAY IN LINCOLN COUNTY AS THE LATEST MODELS SHOW A BIT MORE QPF
IN THE PANHANDLE.
&&
.AVIATION...FOR MCCARRAN...WINDS SHOULD BE 6 KTS OR LESS AND FAVOR
TYPICAL DIURNAL DIRECTIONAL TRENDS. MAINLY BKN CLOUDS AOA 20K FEET
WITH FEW-SCT CLOUDS AS LOW AS 15K FEET OVERNIGHT AND AS LOW AS 10K
FEET ON SATURDAY.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...WINDS WILL BE 6 KTS OR LESS AND TREND TOWARD TYPICAL
DIURNAL DIRECTIONS. A FEW SHOWERS WILL BE POSSIBLE ACROSS THE HIGHER
ELEVATIONS OF INYO, ESMERALDA, CENTRAL NYE AND NORTHERN LINCOLN
COUNTIES THROUGH SATURDAY. CIGS AS LOW AS 6K-8K FEET IN AND NEAR ANY
SHOWERS OTHERWISE EXPECT MAINLY BKN CLOUDS AOA 20K FEET WITH A FEW
CLOUDS AS LOW AS 10K-12K FEET.
&&
.PREVIOUS DISCUSSION...
ISSUED AT 300 PM PST FRI DEC 19 2014
DISCUSSION...
ANY SHOWERS THAT DO FALL ARE EXPECTED TO REMAIN LIGHT AND ANY UPPER
ELEVATIONS SNOWFALL /ABOVE 6500 FEET/ WILL REMAIN WELL BELOW
ADVISORY LEVELS. THIS SYSTEM WILL CONTINUE TO PUSH EAST TONIGHT
WITH ONLY A SLIGHT CHANCE OF SHOWERS FOR ESMERALDA...CENTRAL NYE AND
NORTHERN LINCOLN COUNTIES. HIGH PRESSURE WILL START TO STRENGTHEN
OVER THE EASTERN PACIFIC LATE SATURDAY AND SLOWLY DRIFT EAST BY
SUNDAY. A DRIER NORTHWEST FLOW WILL SET UP OVER THE AREA THROUGH
MONDAY...BUT SURFACE HIGH PRESSURE IS FORECAST TO BUILD OVER IDAHO
AND MOVE INTO WYOMING MONDAY EVENING AND TUESDAY. THIS WILL CAUSE
THE SURFACE GRADIENT TO INCREASE DOWN THE COLORADO RIVER VALLEY AND
BRING SOME GUSTY NORTH WINDS TO THE AREA...ESPECIALLY AROUND
LAUGHLIN/BULLHEAD CITY. BY TUESDAY AFTERNOON THE HIGH PRESSURE RIDGE
WILL MOVE OVER THE AREA BRINGING LIGHT WINDS AND ABOVE NORMAL
TEMPERATURES. READINGS BY MID WEEK MAY BE AS HIGH AS 10 DEGREES
ABOVE NORMAL. HOWEVER...SURFACE INVERSIONS MAY HELP KEEP THOSE
NUMBERS DOWN A LITTLE. BEYOND WEDNESDAY GETS A LITTLE TRICKY AS THE
GFS/ECMWF DIFFER ON A POTENTIAL TROUGH MOVING INTO THE AREA ON
CHRISTMAS DAY. IT DOES LOOK LIKE WINDS WILL START TO INCREASE
WEDNESDAY AFTERNOON...WHICH WILL LIKELY MAKE WEDNESDAY THE WARMEST
DAY OF NEXT WEEK AND THEN A COLD FRONT WILL MOVE THROUGH ON
THURSDAY. HOWEVER...THE STRENGTH OF THE FRONT AND HOW FAR SOUTH THIS
SYSTEM DIGS IN ALSO IN QUESTION. FOR NOW IT DOES LOOK LIKE WE WILL
SEE SOME WINDIER AND COOLER WEATHER ON CHRISTMAS WITH THE POTENTIAL
OF SHOWERS AT LEAST ACROSS NORTHERN AND CENTRAL NEVADA. &&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT EXPECTED.
&&
$$
UPDATE/AVIATION....STACHELSKI
PREVIOUS...GORELOW
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
353 AM CST SAT DEC 20 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CST SAT DEC 20 2014
MAIN CONCERNS IN THE SHORT TERM ARE THE PERSISTENT FOG IN THE NORTH
AND CENTRAL TODAY...AND PRECIPITATION CHANCES AND WEATHER TYPE FOR
TODAY AND TONIGHT.
CURRENTLY...WATER VAPOR SATELLITE LOOP INDICATES THE NEXT UPPER
LEVEL SHORTWAVE TO AFFECT THE STATE TODAY WAS OVER NORTH CENTRAL
MONTANA/SOUTHERN SASKATCHEWAN/ALBERTA. AT THE SURFACE...LOW PRESSURE
WAS CENTERED OVER THE SOUTHERN BORDER OF ALBERTA/SASKATCHEWAN WITH A
TROUGH EXTENDING SOUTHEAST ACROSS EASTERN MONTANA. WIDESPREAD FOG
WITH VISIBILITIES RANGING FROM 1/4 MILE TO 1 MILE EXTENDED ACROSS
NORTHWESTERN AND MUCH OF CENTRAL NORTH DAKOTA.
TODAY THE UPPER LEVEL LOW/TROUGH IS PROGGED TO ENTER WESTERN NORTH
DAKOTA THIS MORNING AND ENTER CENTRAL NORTH DAKOTA THIS
AFTERNOON...EXITING NORTH DAKOTA SUNDAY MORNING. AT THE
SURFACE...THE SURFACE LOW AND ATTENDANT WARM FRONT IS FORECAST TO
MOVE EAST TODAY. THE LOW SHOULD MOVE EAST ACROSS SOUTHERN
SASKATCHEWAN/MANITOBA...WITH THE WARM FRONT ENTERING WESTERN NORTH
DAKOTA THIS MORNING...AND CENTRAL NORTH DAKOTA THIS AFTERNOON.
REGARDING THE FOG...AS THE AFOREMENTIONED SYSTEM MOVES INTO WESTERN
NORTH DAKOTA VISIBILITIES SHOULD IMPROVE WITH SUFFICIENT LOW TO MID
LEVEL MIXING. THE HRRR VISIBILITY PROGS SUPPORT THIS AS WELL. AREAS
OF FOG SHOULD PERSIST IN CENTRAL NORTH DAKOTA INTO THE
AFTERNOON...IMPROVING VISIBILITIES WITH TIME FROM WEST TO EAST AS THE
LOW PRESSURE SYSTEM ADVANCES EASTWARD.
THE SHORTWAVE AND SURFACE WARM FRONT WILL ALSO BRING LIGHT SCATTERED
PRECIPITATION TODAY AND TONIGHT. LOOKING AT INCREASING CHANCES THIS
MORNING IN THE WEST...EXPANDING INTO CENTRAL NORTH DAKOTA THIS
AFTERNOON. WARM ADVECTION ALOFT WILL RESULT IN MIXED PRECIPITATION
OF FREEZING DRIZZLE OR DRIZZLE EARLY THIS MORNING WITH CHANCES OF
LIGHT RAIN/DRIZZLE THIS AFTERNOON IN THE WEST AS TEMPERATURES RISE
INTO THE 30S. FARTHER EAST FREEZING DRIZZLE OR LIGHT SNOW SHOULD BE
THE PREDOMINANT WEATHER TYPE.
TONIGHT THE MAIN ENERGY FROM THE UPPER LEVEL TROUGH SHOULD KEEP THE
CHANCE OF PRECIPITATION CONFINED TO THE NORTH CENTRAL AND JAMES
RIVER VALLEY AND EASTWARD. FREEZING DRIZZLE OR LIGHT SNOW WOULD BE
THE MAIN WEATHER TYPE THERE TONIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 330 AM CST SAT DEC 20 2014
A WINTRY MIX POSSIBLE SUNDAY EVENING INTO MONDAY NIGHT...FOLLOWED
BY SNOWFALL POTENTIAL EARLY NEXT WEEK IMPACTING CHRISTMAS TRAVEL
HIGHLIGHT THE EXTENDED FORECAST.
FOR THE 00 UTC GUIDANCE SUITE...WHILE IN AGREEMENT ON GENERAL
FEATURES THROUGH THE EXTENDED FORECAST...SPATIAL DIFFERENCES IN
THE MASS FIELDS AND TIMING RESULT IN NON-TRIVIAL IMPACTS TO
SENSIBLE WEATHER THROUGH THE PERIOD. OVERALL...WEIGHED HEAVILY ON
THE 00 UTC ECMWF AND 03 UTC SREF WHICH RESIDE IN THE MIDDLE OF THE
ENVELOPE OF SOLUTIONS. FOR SUNDAY...A LEAD SHORTWAVE EJECTING OUT
OF THE ROCKIES IS FORECAST TO RESULT IN A RAIN AND SNOW MIX
DEPENDING ON SURFACE TEMPERATURES ACROSS WESTERN NORTH DAKOTA IN
THE AFTERNOON.
THE CHALLENGE IS SUNDAY EVENING INTO MONDAY NIGHT IN REGARDS TO
PRECIPITATION TYPE ACROSS CENTRAL NORTH DAKOTA. A MELTING LAYER
ALOFT ABOVE SUB-FREEZING SURFACE TEMPERATURES IS FORECAST TO
EXIST. HOWEVER...DRY AIR IN THE 900-750 MB LAYER WILL HAVE TO BE
SATURATED FOR PRECIPITATION TO REACH THE GROUND. THUS ENTERS THE
UNCERTAINTY AS TO HOW MUCH OF THE MELTING LAYER WILL REMAIN POST-
SATURATION DUE TO THE WET-BULB EFFECT. THERE APPEARS TO BE A BRIEF
WINDOW...ESPECIALLY ACROSS SOUTH CENTRAL NORTH DAKOTA...FOR THE
WARM LAYER TO BE AROUND +2 TO +2.5 C AROUND 00-03 UTC FOR A WINTRY
MIX OF FREEZING RAIN...SLEET AND MELTED SNOW TO BE POSSIBLE.
OVERALL AMOUNTS WILL BE LIGHT WITH THE COLUMN QUICKLY COOLING TO
SUPPORT ALL SNOW BETWEEN 03-06 UTC. THEREAFTER...ATTENTION TURNS
TO CYCLOGENESIS ACROSS THE EASTERN DAKOTAS AND INTO THE UPPER
MISSISSIPPI VALLEY MONDAY. THE 00 UTC DETERMINISTIC AND ENSEMBLE
SOLUTIONS SHOW A VARIED UPPER LEVEL LOW POSITION FROM NORTH
DAKOTA ON THE NAM TO IOWA ON THE GFS...WITH THE SREF AND ECMWF IN
BETWEEN. THUS...WIDESPREAD LIGHT SNOW IS EXPECTED FOR THE AREA
MONDAY ON ALL SOLUTIONS...WITH HIGHER AMOUNTS IN BANDING POSSIBLE.
HOWEVER...UNCERTAINTY IN THESE BANDS IS RATHER HIGH UNTIL THE MASS
FIELDS COME INTO BETTER AGREEMENT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1223 AM CST SAT DEC 20 2014
IFR CEILINGS/VISIBILITIES CONTINUE AT KISN KMOT AND KJMS. LATEST
SATELLITE AND MESOSCALE HRRR INDICATE THE STRATUS/FOG SHOULD MOVE
INTO KBIS SHORTLY AFTER 06 UTC. WILL LEAVE KDIK OUT OF THE FOG
TONIGHT AS LATEST ITERATIONS OF THE HRRR BACK OFF ON THE WESTERN
EXTENT OF THE STRATUS. STRATUS WILL ERODE FROM WEST TO EAST ON
SATURDAY AS AN APPROACHING SYSTEM BRINGS A DRIER SOUTHWEST FLOW.
KISN AND KBIS SHOULD CLEAR DURING THE MORNING...KMOT AND KJMS
CLEARING SATURDAY AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
NDZ001>005-009>013-019>023-025-035>037.
&&
$$
SHORT TERM...JV
LONG TERM...AYD
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1223 AM CST SAT DEC 20 2014
.UPDATE...
ISSUED AT 1223 AM CST SAT DEC 20 2014
LATEST HRRR CONTINUES TO INDICATE LOWER VISIBILITIES IN FOG
REMAINING OVER NORTHERN AND CENTRAL/EASTERN NORTH DAKOTA...WITH THE
SOUTHWEST MAINLY STRATUS-FREE. THE HRRR ALSO INDICATES SOME ISOLATED
POCKETS OF FREEZING DRIZZLE/RAIN OVER NORTH CENTRAL INTO
NORTHEASTERN NORTH DAKOTA. HAVE ADDED MENTION OF PATCHY FREEZING
DRIZZLE TO MAINLY TIOGA/STANLEY TO MINOT/GARRISON...TO THE TURTLE
MOUNTAINS/JAMESTOWN AREAS THROUGH THE REST OF TONIGHT UNTIL AROUND 9
AM SATURDAY MORNING. THIS AREA THE HRRR IS TARGETING IS ALSO WHERE
AN UPPER LEVEL SHORTWAVE MOVES SOUTHEAST ACROSS THIS
REGION...EXITING INTO MINNESOTA LATER THIS MORNING. OTHERWISE
CURRENT FORECAST ON TRACK AND HAS A GOOD HANDLE ON FOG...WITH THE
DENSE FOG ADVISORY FROM CROSBY/WILLISTON TO MINOT/BISMARCK TO THE
TURTLE MOUNTAINS/JAMESTOWN. WILL RE-EVALUATE LATER THIS MORNING FOR
ANY CHANGES/EXTENSIONS OF THIS ADVISORY.
UPDATE ISSUED AT 924 PM CST FRI DEC 19 2014
BASED ON LATEST SATELLITE LOOP...SURFACE OBS AND REPORTS...HAVE
DECIDED TO EXTEND THE DENSE FOG ADVISORY FARTHER TO THE SOUTH AND
EAST. REPORTS AND OBSERVATIONS OF VISIBILITIES DURING THE PAST
HOUR SHOW QUARTER MILE OR LESS VSBYS FROM THE HAZEN AREA EAST
ACROSS NORTHERN BURLEIGH COUNTY AND INTO KIDDER AND STUTSMAN
COUNTIES. FARTHER NORTH AND EAST...VISIBILITIES ARE NOT AS LOW
OVER THE TURTLE MOUNTAINS DOWN INTO FOSTER COUNTY NORTH OF
JAMESTOWN. HOWEVER...LATEST HRRR DOES INDICATE LOWER VISIBILITIES
WORKING THIS WAY LATE TONIGHT INTO SATURDAY MORNING. THERE HAS
BEEN LOW STRATUS AND FOG...ESPECIALLY IN THE TURTLE MOUNTAINS AREA
ALL DAY AND ROADS MAY BE SLIPPERY. ALTHOUGH THERE HAVE BEEN NO
REPORTS AS OF YET...THERE HAS BEEN REPORTS OF FREEZING DRIZZLE
JUST TO THE NORTH IN CANADA AND INTO NORTHEAST NORTH DAKOTA.
UPDATE ISSUED AT 549 PM CST FRI DEC 19 2014
MAIN UPDATE THIS AFTERNOON IS TO EXPAND THE DENSE FOG ADVISORY TO
INCLUDE DIVIDE AND WILLIAMS COUNTIES IN NORTHWEST NORTH
DAKOTA...AND MCLEAN...SHERIDAN AND WELLS COUNTIES IN CENTRAL NORTH
DAKOTA. LATEST SURFACE OBSERVATIONS AND WEATHER CAMERAS INDICATE
THE LOWEST VISIBILITIES ARE ALONG THE PERIPHERY OF THE STRATUS
LAYER FROM DIVIDE AND WILLIAMS COUNTIES SOUTHEAST TO AROUND
GARRISON IN MCLEAN COUNTY AND THEN EAST TOWARD HARVEY IN WELLS
COUNTY. LATEST HRRR MODEL ITERATION SHOWS THE STRATUS EXPANDING
SOUTH AND WEST THIS EVENING...WHICH LOOKS TO VERIFY FROM LAST FEW
SATELLITE IMAGES. OTHERWISE ONLY MINOR UPDATES FOR SKY COVER AND
POPULATED LATEST SENSIBLE WEATHER ELEMENTS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 303 PM CST FRI DEC 19 2014
.SHORT TERM...TONIGHT THROUGH SATURDAY...
PERSISTENT FOG ACROSS THE NORTH WITH CURRENT SATELLITE LOOPS SHOWING
THE STRATUS IS EXPANDING SOUTH INTO THE JAMES NORTHERN JAMES RIVER
VALLEY. NAM BUFKIT SOUNDINGS HAVE A SOLID STRATUS AND FOG LOW LEVEL
SOUNDING FROM WILLISTON THROUGH MINOT WHILE THE GFS MIXES IT OUT
THIS EVENING. WILL LEAN TO THE NAM AND KEEP FOG AND LOW CLOUDS
THOUGH THE NORTH AND EAST CENTRAL TONIGHT. FURTHER ISSUES INVOLVE
VSBYS AS LOW AS ONE QUARTER MILE NEAR TIOGA TO STANLEY. DO NOT
SEE MUCH IMPROVEMENT THERE AND SHOULD SEE LOWER VSBYS IN MINOT
LATER TONIGHT AFTER SUNSET. WILL GO WITH A DENSE FOG ADVISORY FROM
TIOGA TO STANLEY THROUGH 9 PM THEN EXPAND IT EAST THROUGH MINOT
AND TO BOTTINEAU AND MCHENRY COUNTIES THROUGH SATURDAY MORNING.
THE FOG WILL ALSO INSULATE A BIT SO HAVE RAISED TEMPERATURES FOR
OVERNIGHT NIGHT LOWS.
ON SATURDAY...WEAK SHORTWAVE WILL BRING LIGHT AND SPOTTY
PRECIPITATION. EXPECT A WINTRY MIX OF FREEZING RAIN...SOME SLEET AND
SNOW BUT LITTLE ACCUMULATIONS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 303 PM CST FRI DEC 19 2014
FOCUS IN THE LONG TERM IS ON THE LARGE SCALE UPPER LEVEL TROUGH THAT
DEVELOPS OVER THE NORTHERN PLAINS SUNDAY AND DEEPENS SIGNIFICANTLY
OVER THE CENTRAL UNITED STATES INTO EARLY NEXT WEEK.
PAST RUNS OF THE ECMWF AND GFS HAVE CONSISTENTLY SHOWN A DEEPENING
TROUGH OVER THE CENTRAL UNITED STATES SUNDAY INTO EARLY NEXT WEEK.
THE LATEST 12 UTC RUNS OF THE ECMWF AND GFS HAVE BACKED THE SYSTEM
UP A BIT...DEVELOPING A CUT OFF UPPER LEVEL LOW OVER SOUTH DAKOTA
MONDAY WHICH SLOWLY PROPAGATES EAST INTO TUESDAY. THESE SOLUTIONS
BOTH SHOW MORE QPF OVER CENTRAL AND WESTERN NORTH DAKOTA THAN
PREVIOUS MODEL RUNS.
VERTICAL PROFILES ALSO LOOK TO BE BETTER MIXED AFTER THE WEAK
SURFACE COLD FRONT MOVES THROUGH SUNDAY NIGHT. BEFORE THE FRONT
PASSES A LIGHT WINTRY MIX OF FREEZING RAIN...SLEET...RAIN...AND SNOW
WILL BE POSSIBLE ACROSS THE WEST SUNDAY MORNING AND AFTERNOON. ANY
ACCUMULATIONS WILL BE MINOR. STARTING SUNDAY NIGHT THE SOUTHWEST MAY
SEE A BRIEF PERIOD OF RAIN MIXED WITH SNOW...HOWEVER FOR THE REST OF
THE STATE ALL SNOW IS ANTICIPATED. MONDAY AND TUESDAY PRECIPITATION
IS FORECAST AS ALL SNOW AS WELL FOR ALL OF CENTRAL AND WESTERN NORTH
DAKOTA. WITH THAT SAID IF MODEL SOLUTIONS PROGRESS THE TROUGH ALONG
QUICKER SUNDAY NIGHT AND MONDAY...PROFILES ALOFT COULD BE TO DRY FOR
ICE CRYSTALS AND WESTERN AND CENTRAL NORTH DAKOTA COULD ONCE AGAIN
SEE SOME FREEZING RAIN OR DRIZZLE.
EARLY ESTIMATES ON SNOW ACCUMULATIONS FOR MONDAY INTO TUESDAY RANGE
FROM AROUND 2 INCHES WEST TO AN INCH ELSEWHERE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1223 AM CST SAT DEC 20 2014
IFR CEILINGS/VISIBILITIES CONTINUE AT KISN KMOT AND KJMS. LATEST
SATELLITE AND MESOSCALE HRRR INDICATE THE STRATUS/FOG SHOULD MOVE
INTO KBIS SHORTLY AFTER 06 UTC. WILL LEAVE KDIK OUT OF THE FOG
TONIGHT AS LATEST ITERATIONS OF THE HRRR BACK OFF ON THE WESTERN
EXTENT OF THE STRATUS. STRATUS WILL ERODE FROM WEST TO EAST ON
SATURDAY AS AN APPROACHING SYSTEM BRINGS A DRIER SOUTHWEST FLOW.
KISN AND KBIS SHOULD CLEAR DURING THE MORNING...KMOT AND KJMS
CLEARING SATURDAY AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
NDZ001>005-009>013-019>023-025-035>037.
&&
$$
UPDATE...JV
SHORT TERM...WAA
LONG TERM...MM
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1117 PM CST FRI DEC 19 2014
.DISCUSSION...
SEE 06Z AVIATION DISCUSSION.
&&
.AVIATION...
NAM12 AND RAP SOUNDINGS CONTINUE TO ADVERTISE IFR CIGS OVERNIGHT
WITH GRADUAL IMPROVEMENT SATURDAY AFTN. VFR CONDS EVENTUALLY
EXPECTED BY 21/2100Z. WINDS WILL REMAIN LIGHT OVERNIGHT EXCEPT
NEAR THE COAST. SOME PATCHY FOG WILL ALSO BE POSSIBLE THROUGH THE
OVERNIGHT HOURS. 43
&&
.PREV DISCUSSION... /ISSUED 828 PM CST FRI DEC 19 2014/
UPDATE...
A STRATUS DECK REMAINS IN PLACE ACROSS SOUTHEAST TEXAS
TONIGHT...WITH AMDAR SOUNDINGS INDICATING THE DEPTH OF THESE
LOW CLOUDS AROUND 1000 FT. THIS CLOUD LAYER IS THIN ENOUGH TO
ALLOW FOR SUFFICIENT RADIATIONAL COOLING FOR FOG DEVELOPMENT AND
SEVERAL OBSERVATION SITES WERE ALREADY REPORTING MINOR REDUCTIONS
IN VISIBILITY AS OF 8 PM. HAVE ADDED PATCHY FOG INTO THE FORECAST
AND REMOVED RAIN MENTION OVER THE COASTAL WATERS AS ALL ACTIVITY
HAS MOVED EAST OF THE AREA. OTHERWISE... FORECAST REMAINS ON TRACK
FOR TONIGHT WITH GENERALLY LIGHT NORTHERLY WINDS IN PLACE AND LOWS
FALLING INTO THE MID TO UPPER 40S INLAND AND NEAR 50 ALONG THE
COAST.
HUFFMAN
PREV DISCUSSION... /ISSUED 545 PM CST FRI DEC 19 2014/
DISCUSSION...
SEE 00Z AVIATION DISCUSSION.
AVIATION...
RAP AND NAM12 FCST SOUNDINGS MAINTAIN IFR CIGS OVERNIGHT WITH SLOW
IMPROVEMENT TO MVFR ON SATURDAY. WET GROUNDS AND LIGHT WINDS WILL
ALSO LEAD TO AT LEAST SOME PATCHY FOG OVERNIGHT AS WELL. WINDS
WILL GRADUALLY RELAX THIS EVENT EXCEPT ALONG THE IMMEDIATE COAST.
43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 47 56 46 59 46 / 10 0 0 0 0
HOUSTON (IAH) 49 58 46 60 46 / 10 0 0 0 0
GALVESTON (GLS) 51 57 52 59 52 / 10 10 10 10 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 4 AM CST SATURDAY FOR
THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 6 AM CST SATURDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20
TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
436 AM PST SAT DEC 20 2014
.SYNOPSIS...SCATTERED SHOWERS WILL CONTINUE ACROSS OUR AREA TODAY
AND SLOWLY DIMINISH TONIGHT. THIS WILL BE FOLLOWED BY A RIDGE OF
HIGH PRESSURE BUILDING OVER THE WEST COAST RESULTING IN A DRYING
AND WARMING TREND THROUGH AT LEAST MOST OF NEXT WEEK.
&&
.DISCUSSION...AS OF 3:10 AM PST SATURDAY...SURPRISING NUMBER OF
SHOWERS OVERNIGHT WITH 12 HOUR RAINFALL TOTALS QUITE A BIT ABOVE
EXPECTATIONS. IN FACT...PORTIONS OF SANTA CRUZ COUNTY ARE WELL
OVER AN INCH AND ON THEIR WAY TO HITTING 1.5 INCHES. CURRENT RADAR
LOOP SHOWS BULK OF ACTIVITY STRETCHING IN A BAND FROM SANTA CRUZ
AND SAN MATEO COUNTIES NE THROUGH SANTA CLARA COUNTY. HRRR SEEMS
TO HAVE DONE A FAIRLY GOOD JOB WITH SHOWING THE EVOLUTION AND
TENDED TO FAVOR IT FOR THE SHORT TERM FORECAST. IT INDICATES THAT
SHOWERS WILL BE ON THE DECREASE THROUGH THE DAY ALTHOUGH ALL
LOCATIONS WILL HAVE AT LEAST A SHOT AT GETTING LIGHT RAINFALL.
POPS WERE PUSHED UP FOR VIRTUALLY ALL SPOTS AND MAY HAVE BE
INCREASED EVEN MORE IF THEY SHOWERS DO NOT START TO DISSIPATE
BEFORE SUNRISE. IN GENERAL RAINFALL AMOUNTS WILL BE LIGHT TODAY
HOWEVER WOULD NOT BE SURPRISED IF A FEW LOCATIONS GET AN
ADDITIONAL HALF AN INCH BY TONIGHT.
A RIDGE OF HIGH PRESSURE ALONG WITH WARMER 850 MB READINGS WILL
START TO NOSE INTO OUR CWA TOMORROW AND REMAIN IN CONTROL AT LEAST
INTO TUESDAY. THIS WILL ALLOW FOR DRYING PLUS WARMER READINGS IN
ALL LOCATIONS. TUESDAY IS EXPECTED TO BE THE WARMEST DAY OF THE
WEEK WITH HIGHS IN THE 60S TO LOWER 70S.
AN INSIDE SLIDER WILL DROP DOWN CHRISTMAS EVE (WEDNESDAY) MOSTLY
IMPACTING AREAS TO OUR NORTH AND EAST WITH RAIN ANS SNOW.
HOWEVER...GUIDANCE CONTINUES TO SHOW THE SOUTHERN EXTENT OF THE
MOISTURE MOVING THROUGH OUR AREA ESPECIALLY THE NORTH BAY. THE
BIGGER IMPACT WILL BE TO COOL OFF TEMPERATURES BACK TO NEAR NORMAL
LEVELS. COULD ALSO SEE A FEW INLAND SPOTS DROPPING BACK INTO THE
MID 30S.
LONGER RANGE OUTLOOK GOING INTO 2015 HAS DRIER THAN NORMAL WEATHER
FORECAST. RIGHT NOW TRAVEL CONDITIONS FROM CHRISTMAS TO NEW YEARS
LOOK TO BE GOOD AROUND OUR AREA.
&&
.AVIATION...AS OF 4:15 AM PST SATURDAY...ABUNDANT LOW LEVEL
MOISTURE LEFT OVER FROM THE PAST SYSTEM IS BRINGING LOW CIGS TO
THE SFO BAY AREA. A FEW SHOWERS LINGER FROM THE SOUTH BAY TO THE
MRY BAY AREA. IFR CIGS EXPECTED TO LIFT TO MVFR AFTER 17Z AND VFR
BY 20Z AS THE NEXT APPROACHING SYSTEM PROVIDES SOME MIXING. RAIN
CONFINED TO THE NORTH BAY THIS AFTERNOON AND EVENING. PRESSURES
REMAINING STABLE SO SOUTHEAST WINDS STAYING BELOW 5 KT THROUGH THE
DAY.
VICINITY OF KSFO...IFR CIGS LIFTING TO MVFR AFTER 17-18Z AND VFR
AFTER 20Z. LIGHT SOUTHEAST WINDS 5 KT OR LESS THROUGH THE DAY.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR CONDITIONS WITH CIGS 4000 FEET
OR ABOVE. ISOLATED LIGHT SHOWERS THROUGH 16Z.
&&
.MARINE...AS OF 4:15 AM PST SATURDAY...LARGE SWELLS HAVE ARRIVED
ALONG THE COAST. AS OF 4 AM...BUOYS REPORT SEAS RANGING FROM 21
FEET AT PT ARENA BUOY TO 13 FEET AT MONTEREY BAY BUOY. SWEL
PERIODS ARE 17-18 SECONDS. EXPECTING SEAS IN THE 17-20 FOOT RANGE
THIS MORNING DECREASING SLOWLY THIS AFTERNOON AND EVENING. HIGH
TIDE AROUND 8:30 AM COULD CAUSE MINOR COASTAL FLOODING NEAR THE
OCEAN. MAIN CONCERN WILL BE DURING KING TIDE SUNDAY MORNING AFTER
9 AM. ALTHOUGH SEAS WILL BE SLIGHTLY LOWER AND SWELL PERIOD WILL
BECOME 14-15 SEONDS...COASTAL FLOODING IS POSSIBLE IN THE SF BAY
AS WELL AS THE OCEAN.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...HIGH SURF ADVISORY AND COASTAL FLOOD
ADVISORY...ALL COASTAL LOCATIONS TODAY
SCA...PT ARENA TO PT REYES 0-10 NM UNTIL 3 PM
SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 3 PM
SCA...PIGEON PT TO PT PINOS 0-10 NM UNTIL 3 PM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 3 PM
SCA...PT ARENA TO PT REYES 10-60 NM UNTIL 3 PM
SCA...PT REYES TO PIGEON PT 10-60 NM UNTIL 3 PM
SCA...PIGEON PT TO PT PINOS 10-60 NM UNTIL 3 PM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 3 PM
SCA...ROUGH BAR ADVISORY FOR SF BAR
&&
$$
PUBLIC FORECAST: BELL
AVIATION/MARINE: W PI
VISIT US AT WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
313 AM PST SAT DEC 20 2014
.SYNOPSIS...SCATTERED SHOWERS WILL CONTINUE ACROSS OUR AREA TODAY
AND SLOWLY DIMINISH TONIGHT. THIS WILL BE FOLLOWED BY A RIDGE OF
HIGH PRESSURE BUILDING OVER THE WEST COAST RESULTING IN A DRYING
AND WARMING TREND THROUGH AT LEAST MOST OF NEXT WEEK.
&&
.DISCUSSION...AS OF 3:10 AM PST SATURDAY...SURPRISING NUMBER OF
SHOWERS OVERNIGHT WITH 12 HOUR RAINFALL TOTALS QUITE A BIT ABOVE
EXPECTATIONS. IN FACT...PORTIONS OF SANTA CRUZ COUNTY ARE WELL
OVER AN INCH AND ON THEIR WAY TO HITTING 1.5 INCHES. CURRENT RADAR
LOOP SHOWS BULK OF ACTIVITY STRETCHING IN A BAND FROM SANTA CRUZ
AND SAN MATEO COUNTIES NE THROUGH SANTA CLARA COUNTY. HRRR SEEMS
TO HAVE DONE A FAIRLY GOOD JOB WITH SHOWING THE EVOLUTION AND
TENDED TO FAVOR IT FOR THE SHORT TERM FORECAST. IT INDICATES THAT
SHOWERS WILL BE ON THE DECREASE THROUGH THE DAY ALTHOUGH ALL
LOCATIONS WILL HAVE AT LEAST A SHOT AT GETTING LIGHT RAINFALL.
POPS WERE PUSHED UP FOR VIRTUALLY ALL SPOTS AND MAY HAVE BE
INCREASED EVEN MORE IF THEY SHOWERS DO NOT START TO DISSIPATE
BEFORE SUNRISE. IN GENERAL RAINFALL AMOUNTS WILL BE LIGHT TODAY
HOWEVER WOULD NOT BE SURPRISED IF A FEW LOCATIONS GET AN
ADDITIONAL HALF AN INCH BY TONIGHT.
A RIDGE OF HIGH PRESSURE ALONG WITH WARMER 850 MB READINGS WILL
START TO NOSE INTO OUR CWA TOMORROW AND REMAIN IN CONTROL AT LEAST
INTO TUESDAY. THIS WILL ALLOW FOR DRYING PLUS WARMER READINGS IN
ALL LOCATIONS. TUESDAY IS EXPECTED TO BE THE WARMEST DAY OF THE
WEEK WITH HIGHS IN THE 60S TO LOWER 70S.
AN INSIDE SLIDER WILL DROP DOWN CHRISTMAS EVE (WEDNESDAY) MOSTLY
IMPACTING AREAS TO OUR NORTH AND EAST WITH RAIN ANS SNOW.
HOWEVER...GUIDANCE CONTINUES TO SHOW THE SOUTHERN EXTENT OF THE
MOISTURE MOVING THROUGH OUR AREA ESPECIALLY THE NORTH BAY. THE
BIGGER IMPACT WILL BE TO COOL OFF TEMPERATURES BACK TO NEAR NORMAL
LEVELS. COULD ALSO SEE A FEW INLAND SPOTS DROPPING BACK INTO THE
MID 30S.
LONGER RANGE OUTLOOK GOING INTO 2015 HAS DRIER THAN NORMAL WEATHER
FORECAST. RIGHT NOW TRAVEL CONDITIONS FROM CHRISTMAS TO NEW YEARS
LOOK TO BE GOOD AROUND OUR AREA.
&&
.AVIATION...AS OF 9:48 PM PST FRIDAY...A COLD FRONT CONTINUES TO
PASS OVER THE FORECAST AREA. PRECIPITATION IS NOW CONFINED TO SOUTH
OF THE SAN FRANCISCO BAY AREA. THE FRONT IS NO LONGER EXPECTED TO
BE STRONG ENOUGH TO MIX THE LOW CLOUDS OUT SO EXPECT MVFR CIGS AT
MOST TERMINALS OVERNIGHT. RAIN SHOULD END SHORTLY IN THE SAN JOSE
AREA BUT STICK AROUND UNTIL THE EARLY MORNING HOURS IN MONTEREY.
VICINITY OF KSFO...MVFR CIGS WILL PREVAIL THROUGH AROUND 1900Z
SATURDAY. ONCE THE CLOUDS LIFT ON SATURDAY VFR IS ANTICIPATED INTO
THE EVENING HOURS. WINDS ARE EXPECTED TO BE GENERALLY LIGHT
SOUTHERLY THROUGH THE FORECAST PERIOD.
CONFIDENCE IS MODERATE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MVFR CIGS AND LIGHT RAIN ARE
ANTICIPATED OVERNIGHT WITH RAIN ENDING BY SUN RISE. VFR IS
ANTICIPATED BY AROUND 1800Z SATURDAY.
CONFIDENCE IS MODERATE.
&&
.MARINE...AS OF 3:10 AM PST SATURDAY...A LARGE STORM IN THE GULF OF
ALASKA HAS GENERATED LARGE LONG- PERIOD SWELLS THAT WILL IMPACT
THE COASTAL WATERS THROUGH TONIGHT. SURFACE HIGH PRESSURE WILL
BUILD OFF THE CALIFORNIA COAST TONIGHT INTO EARLY NEXT WEEK
RESULTING IN INCREASING NORTHWEST WINDS OVER THE SOUTHERN WATERS
BEGINNING SUNDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...HIGH SURF ADVISORY AND COASTAL FLOOD
ADVISORY...ALL COASTAL LOCATIONS TODAY
SCA...PT ARENA TO PT REYES 0-10 NM UNTIL 3 PM
SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 3 PM
SCA...PIGEON PT TO PT PINOS 0-10 NM UNTIL 3 PM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 3 PM
SCA...PT ARENA TO PT REYES 10-60 NM UNTIL 3 PM
SCA...PT REYES TO PIGEON PT 10-60 NM UNTIL 3 PM
SCA...PIGEON PT TO PT PINOS 10-60 NM UNTIL 3 PM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 3 PM
SCA...ROUGH BAR ADVISORY FOR SF BAR
&&
$$
PUBLIC FORECAST: BELL
AVIATION: LARRY
MARINE: W PI
VISIT US AT WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS TAUNTON MA
958 AM EST SAT DEC 20 2014
.SYNOPSIS...
SCATTERED SNOW/RAIN SHOWERS WILL GRADUALLY OVERSPREAD THE REGION
FROM EAST TO WEST LATER TODAY INTO SUN. WEAK LOW PRESSURE WILL
PASS SOUTH OF NEW ENGLAND BRINGING ANOTHER PERIOD OF PRECIP MON
NIGHT AND TUE. A MUCH STRONGER STORM PASSING WEST OF NEW ENGLAND
WILL BRING HEAVY RAINFALL...GUSTY WINDS AND COASTAL FLOODING
CONCERNS TO THE REGION WED INTO WED EVENING. DRY BUT VERY WINDY
CONDITIONS FOLLOW FOR CHRISTMAS DAY INTO FRI.
&&
.NEAR TERM /UNTIL NOON TODAY/...
10 AM UPDATE...MADE MINOR UPDATES MAINLY TO THE WINDS AND POPS.
UPDATED WINDS USING THE RAP FOR ITS HIGHER DETAIL WITH THE COASTAL
FRONT THIS AFTERNOON. SNOW SHOWERS HAVE MOVED ASHORE IN PLYMOUTH
COUNTY AS WELL AS PORTIONS OF THE CAPE AND THE EASTERN END OF CAPE
ANN. EXPECT THESE TO CONTINUE OFF AND ON THROUGH THE REMAINDER OF
THE MORNING.
SATELLITE IMAGERY SHOWS AN INTERESTING PATTERN. LOW CLOUDS MOVING
WESTWARD OFF THE OCEAN HAVE CREPT IN ALONG THE EAST COAST. THEN
ANOTHER AREA OF LOW CLOUDS HAVE MOVED NORTHWARD TOO ABOUT THE MASS
PIKE. NORTHWESTERN MASS SHOULD REMAIN MOSTLY SUNNY THROUGH THE
MORNING AND INTO THE AFTERNOON WHILE CLOUDS CONTINUE TO MOVE
WESTWARD ACROSS EASTERN MASSACHUSETTS.
&&
.SHORT TERM /NOON TODAY THROUGH 6 PM SUNDAY/...
THIS AFTERNOON AND TONIGHT...
INTERESTING MESOSCALE SETUP AS AN INVERTED TROUGH COMBINES WITH SOME
OCEAN ENHANCEMENT. APPROACHING UPPER LEVEL SHORTWAVE WILL ALLOW FOR
EASTERLY FLOW JUST OFF THE GROUND. THIS COMBINED WITH NORTHEAST
SURFACE WINDS WILL ALLOW LOW LEVEL OF THE ATMOSPHERE TO MOISTEN.
SOUNDINGS ACROSS EASTERN NEW ENGLAND BECOME SATURATED ALL THE WAY UP
TO THE -9C LAYER JUST ABOVE 850 MB. THIS IS FAVORABLE FOR SOME
DECENT SNOW GROWTH...ITS JUST LOWER IN THE ATMOSPHERE THAN WE
TYPICALLY SEE WITH MORE SYNOPTIC SNOW EVENTS. WHILE THIS IS NOT A
TRUE OCEAN EFFECT EVENT...DELTA T VALUES FROM THE MIXED LAYER TO THE
OCEAN ARE AROUND 15C. THEREFORE...EXPECT SOME OCEAN ENHANCEMENT.
TIMING:
WHILE FLURRIES/LIGHT SNOW SHOWERS MAY OCCUR ACROSS FAR SOUTHEAST NEW
ENGLAND THIS MORNING. THE MORE SUBSTANTIAL PRECIPITATION SHOULD
OVERSPREAD PLYMOUTH COUNTY AS WELL AS THE CAPE AND ISLANDS THIS
AFTERNOON. GIVEN EASTERLY FLOW JUST OFF THE GROUND...EXPECT SNOW
SHOWERS TO OVERSPREAD MOST OF EASTERN NEW ENGLAND THIS EVENING AS
LOW LEVELS MOISTEN. IN FACT...SHOULD SEE AT LEAST SOME SCATTERED
SNOW SHOWERS AFFECT EVEN OUR FAR WESTERN ZONES.
PTYPE:
MAINLY SNOW FOR ALL BUT PORTIONS OF COASTAL PLYMOUTH COUNTY AND ONTO
THE CAPE/ISLANDS. A SUBTLE COASTAL FRONT LOOKS TO SETUP ACROSS
SOUTHEAST COASTAL PLYMOUTH COUNTY. PTYPE WILL BE SNOW TO THE
NORTHWEST OF THIS REGION...BUT ENOUGH MILD AIR SHOULD COME IN OFF
THE OCEAN FOR A CHANGE TO RAIN SHOWERS SOUTHEAST OF THIS REGION.
NOT EXPECTING THE POSITION OF THIS SUBTLE BOUNDARY TO CHANGE MUCH
THROUGH SUNDAY MORNING.
SNOW ACCUMULATIONS:
WE ARE GENERALLY LOOKING AT A COATING TO 2 INCHES OF SNOW ACROSS
MOST OF THE REGION. THE MAIN FOCUS FOR 1 TO 2 INCHES WILL BE ACROSS
PORTIONS OF SOUTHEAST MA...AWAY FROM THE SOUTHEAST PLYMOUTH COUNTY
COAST. ALSO...THE WORCESTER HILLS INTO NORTHWEST RHODE ISLAND MIGHT
BE ANOTHER AREA AS A RESULT OF THE SUBTLE UPSLOPE COMPONENT TO THE
WIND. YOU CAN ACTUALLY SEE THAT IN SOME OF THE HIGH RESOLUTION
MODEL GUIDANCE.
THERE IS ONE AREA TO WATCH IN PARTICULAR...FROM NORTHWEST PLYMOUTH
COUNTY AND INTO NORFOLK COUNTY BASED ON MESOSCALE MODELS AND PATTERN
RECOGNITION. WOULD NOT BE SURPRISED TO SEE VERY LOCALIZED 3 TO 4
INCH SNOW AMOUNTS...GIVEN SOME OCEAN ENHANCEMENT AND A LITTLE FOCUS
ON THE COASTAL FRONT. WILL TRY TO HIGHLIGHT THIS AREA IN OUR
SNOWFALL AND PROBABILISTIC GRAPHICS.
SUNDAY...
SCATTERED SNOW SHOWERS WILL CONTINUE DURING THE MORNING WITH MOIST
EASTERLY FLOW IN THE LOW LEVELS. AGAIN...PTYPE WILL BE SNOW EXCEPT
ACROSS SOUTHEAST PLYMOUTH COUNTY/CAPE AND ISLANDS WHERE BOUNDARY
LAYER WILL PROBABLY BE WARM ENOUGH FOR RAIN SHOWERS. WHILE SOME
LIGHT PRECIPITATION MAY LINGER INTO SUNDAY AFTERNOON...EXPECT A
DECREASE IN AREAL COVERAGE THROUGH THE AFTERNOON AS LOW LEVEL LIFT
WEAKENS. IT WILL REMAIN CLOUDY THOUGH WITH TEMPS IN THE 30S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...
* INVERTED TROUGH WILL BRING RAIN/SNOW SHOWERS TO THE MASS EAST
COASTLINE MONDAY INTO TUES MORNING.
* WEAK WAVE OF LOW PRESSURE MON NIGHT/TUESDAY COULD BRING WINTRY
MIX TO INTERIOR
* ANOMALOUS SYSTEM ACROSS THE GREAT LAKES WILL BRING HEAVY
RAIN...GUSTY WINDS AND COASTAL FLOODING CONCERNS AROUND CHRISTMAS
EVE
OVERVIEW...
OVERALL 00Z GUIDANCE IS IN AGREEMENT SYNOPTICALLY WITH ISSUES ON
TIMING AND SMALLER SCALE FEATURES. IT REMAINS EVIDENT THAT AN
AMPLIFIED MID-UPPER LEVEL TROUGH AND PCPN FOCUSING LEAD SURFACE
LOW/FRONTAL SYSTEM WILL STEADILY PROGRESS TO THE EAST-CENTRAL U.S.
TUE AS EMBEDDED IMPULSES DIG TO THE LEE OF AN AMPLIFIED ERN
PACIFIC/WEST COAST RIDGE ALOFT. THE SUPPORTING AND INCREASINGLY
NEGATIVE-TILT TROUGH ALOFT WORKS OVER THE ERN US AND OUT THROUGH THE
NERN STATES INTO DAYS 4/5 WED/THU. MODELS/ENSEMBLES HAVE BEEN
FAIRLY CONSISTENT ON THIS AMPLIFIED PATTERN AND THE MOST RECENT
GEFS/ECMWF ENSEMBLE GUIDANCE SHOW GOOD CORRELATION TO NEXT THURSDAY.
HIGH PRESSURE AND UPPER LEVEL RIDGE OVER THE REGION WILL BEGIN TO
EXIT BY MONDAY. AT THE SURFACE APPEARS ANOTHER INVERTED
TROUGH/ONSHORE FLOW WILL YIELD TO PRECIP ALONG THE MASS COASTLINE ON
MONDAY. ASIDE FROM THIS QUICK MESOSCALE EVENT THE MAIN FOCUS IS ON
THE LONGWAVE DIGGING TROUGH OVER THE CENTRAL CONUS WHICH WILL PUSH A
FEW SHORTWAVES THROUGH THE FLOW. FIRST ONE DEVELOPS A WEAK WAVE
MOVING TOWARDS THE REGION LATE MONDAY INTO TUESDAY. THERE IS STILL
SOME UNCERTAINTY WITH THE LOCATION/STRENGTH OF THIS SYSTEM BUT
APPEARS THAT THERE IS THE POSSIBILITY OF A SNOW/WINTRY MIX IN THE
INTERIOR. AS THIS SYSTEM DEPARTS AN ANOMALOUS LOW OVER THE GREAT
LAKES WILL DEVELOP A SECONDARY LOW JUST WEST OF SOUTHERN NEW ENGLAND
PER ENSEMBLE GUIDANCE. STILL A SOME SPREAD BUT IF THIS DOUBLE LOW
DOES DEVELOP THEN THE RAIN AND WIND ASPECT OF THE SYSTEM
INCREASES...DETAILS BELOW. STILL NEED TO WORK OUT MINOR DETAILS WITH
THIS PARTICULAR SYSTEM BUT WITH 3 TO 4 STANDARD DEVIATIONS AWAY AND
GENERAL MODEL AGREEMENT HAVE HIGH CONFIDENCE THIS SYSTEM WILL IMPACT
SOUTHERN NEW ENGLAND.
DETAILS...
SUNDAY NIGHT INTO TUESDAY...MODERATE CONFIDENCE.
HIGH PRESSURE AND UPPER LEVEL RIDGE WILL BEGIN TO MOVE OFFSHORE AS
DIGGING TROUGH BEGINS TO SET-UP OVER THE CENTRAL CONUS. APPEARS
ANOTHER MESO-SCALE INVERTED TROUGH WILL SET UP ON MONDAY AND LAST
INTO EARLY TUESDAY MORNING. GUIDANCE SHOWS THAT RAIN/SNOW SHOWERS
WILL DEVELOP ALONG THE MASS EAST COASTLINE THANKS TO ONSHORE
EASTERLY FLOW. APPEARS THE COLUMN WILL SATURATE PER BUFKIT SOUNDINGS
AND SOUTHERLY FLOW ALOFT. BOTH THE NAM AND GFS SHOW QPF MAKING IT
ONSHORE DURING THIS TIME FRAME. HOWEVER THE EC IS SLIGHTLY SLOWER
AND KEEP THE BULK OF THE PRECIP JUST OFFSHORE. ADD A CHANCE OF POPS
DUE TO THE NAM/GFS MODEL CONTINUITY.
BY LATE MONDAY NIGHT INTO TUESDAY A SOUTHERN BRANCH STORM SYSTEM
FORMS ALONG THE SE COAST AND TAKES A TRACK OFF THE MID ATLANTIC
COAST. THIS SYSTEM GETS CAUGHT UP WITH THE OVERALL LARGE SCALE
AMPLIFICATION OF THE UPPER AIR PATTERN. THERE IS DECENT WARM
ADVECTION WITH COLD AIR DAMMING ACROSS THE INTERIOR. BIGGEST
QUESTION WILL BE IS THERE ENOUGH MOISTURE FOR PRECIP DURING THIS
TIME FRAME. IF PRECIP OVERRUNS THEN COULD SEE FREEZING RAIN/DRIZZLE
ACROSS THE INTERIOR LATE MONDAY INTO TUESDAY MORNING. DURING THE DAY
ON TUESDAY...GOOD AMOUNT OF WARM AIR WILL PUSH SURFACE TEMPS ABOVE
FREEZING ALLOWING FOR ANY PRECIP TO BE MORE OF THE LIQUID VARIETY
AHEAD OF THE CHRISTMAS EVE STORM. HOWEVER GUIDANCE IS ALWAYS TOO
FAST IN SCOURING TEMPS OUT ESP ACROSS THE CT VALLEY SO WE WILL NEED
TO MONITOR THIS CLOSELY...ESP DUE TO LIGHT WINDS AND THE HIGH IN
EASTERN CANADA.
WE COULD ALSO SEE SOME MINOR COASTAL FLOODING CONCERNS ON TUESDAY. SEE
BELOW FOR MORE DETAILS.
WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE IN SYSTEM LOW CONFIDENCE
ON DETAILS.
STRONG ANOMALOUS SYSTEM WILL STRENGTHEN OVER THE GREAT
LAKES...DEVELOPING A POTENTIAL SECONDARY SURFACE LOW JUST WEST OF
SOUTHERN NEW ENGLAND. STILL A LOT OF DETAILS TO WORK OUT AS THIS
SYSTEM IS STILL 5 DAYS AWAY...HOWEVER ENSEMBLES CONTINUE TO SHOW
STRONG AGREEMENT SO HAVE INCREASING CONFIDENCE THAT A POTENT STORM
WILL OCCUR. LATEST 00Z GUIDANCE SHOWS THAT MOST PRECIP WILL BE
LIQUID WITH A DEEP SUBTROPICAL CONNECTION BACK ACROSS THE GULF OF
MEXICO...PW ANOMALIES FORECAST TO RISE BETWEEN +3 TO +4. CURRENT
PWATS ARE PROGGED ABOVE 1.6 INCHES SO HAVE CONTINUED THE CATEGORICAL
POPS. TEMPERATURES WILL BE WELL ABOVE AVERAGE...IN FACT WE MAY BE
CLOSE AT BREAKING RECORD HIGH TEMPS IF TEMPS WARM TO 60F OR ABOVE ON
CHRISTMAS EVE. AS THE SYSTEM WRAPS UP INTO CANADA...COLD AIR
ADVECTION SHOULD CIRCULATE AROUND AND BEGIN A TRANSITION FROM
SOUTHWEST TO NORTHEAST IN TURNING P-TYPE TO SNOW. HOWEVER LATEST
GUIDANCE DOES SHOW A QUICK MOVING DRY SLOT SO SNOWFALL WILL STRUGGLE
DUE TO LACK OF MOISTURE.
THIS SYSTEM IS QUITE POTENT SO WE WILL NEED TO WATCH FOR POTENTIAL
HAZARDS. CURRENTLY THINK THAT WE COULD POSSIBLE URBAN FLOODING
ISSUES AS MODELS PROGGED WELL OVER 1.5 INCHES OF QPF. LATEST EC EVEN
SHOWS 2.5 INCHES OF QPF IS POSSIBLE. THE GEFS SHOW A MOISTURE FLUX
AT 850 MB BEING 4 TO 5 STANDARD DEVIATIONS AWAY...AND WITH THE
TROPICAL CONNECTION AND STRONG SOUTHERLY FLOW COULD SEE HIGHER
AMOUNTS DUE TO TOPOGRAPHY ENHANCEMENTS. RAIN FALL RECORDS MAY FALL
IF EVERYTHING FALLS INTO PLACE.
ALSO BELIEVE THAT WE MAY SEE SOME WIND ISSUES WITH THIS SYSTEM.
GUIDANCE RIGHT NOW IS SHOWING A 45 TO 55 KT JET AT 925 MB...HOWEVER
IT WILL BE HARD TO BREAK THE INVERSION WITH THE SOUTHERLY FLOW.
RIGHT NOW BELIEVE THAT WIND ADVISORIES MAY BE NEEDED BUT IF THIS
SYSTEM STRENGTHEN EVEN MORE SO A STRONGER JET IS POSSIBLE.
CONTINUED THE MENTIONED OF ISOLATED THUNDER IN THE FORECAST PER PREV
FORECASTER SUGGESTION. BELIEVE IT COULD BE POSSIBLE AS SOUTHERN NEW
ENGLAND WILL BE IN THE WARM SECTOR...WITH THE ANOMALOUS JET AND
SHOWALTERS CLOSE TO ZERO.
FRIDAY...LOW CONFIDENCE.
ONCE UPPER LEVEL LOW MOVES INTO SOUTHERN CANADA...EXPECT A RATHER
FAST UPPER W FLOW IN PLACE. MAY SEE LEFTOVER SNOW SHOWERS BUT TEMPS
WILL FALL BACK CLOSE TO SEASONAL NORMS.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SUNDAY/...
700 AM UPDATE...
TODAY...MODERATE CONFIDENCE. MVFR CIGS WILL CONTINUE TO OVERSPREAD
EASTERN NEW ENGLAND THIS MORNING AND EVENTUALLY INTO THE INTERIOR
THIS AFTERNOON. SCATTERED PRECIPITATION WILL OVERSPREAD
SOUTHEAST MA/CAPE/ISLANDS THIS AFTERNOON. PTYPE MAINLY SNOW SHOWERS
NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST AND RAIN SHOWERS
SOUTHEAST OF THAT REGION. LOCALIZED IFR CONDITIONS POSSIBLE JUST
INLAND FROM THE SOUTHEAST NEW ENGLAND COAST...WHERE PTYPE IS SNOW.
TONIGHT AND SUNDAY...MODERATE CONFIDENCE. MVFR CONDITIONS DOMINATE
IN LOWER CLOUDS AND SCATTERED PRECIPITATION. LOCALIZED IFR
CONDITIONS POSSIBLE WITH THE BEST CHANCE IN SNOW SHOWERS.
PRECIPITATION AFFECTS MAINLY EASTERN NEW ENGLAND BUT STILL SOME
SCATTERED ACTIVITY ACROSS WESTERN NEW ENGLAND. PTYPE MAINLY SNOW
SHOWERS NORTHWEST OF THE SOUTHEAST PLYMOUTH COUNTY COAST...WITH RAIN
SHOWERS SOUTHEAST OF THAT REGION.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. SNOW SHOWERS MAY ARRIVE
TOWARDS 00Z THIS EVENING.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
MONDAY INTO TUESDAY...MODERATE CONFIDENCE. EXPECT MOSTLY
VFR...ISOLATED MVFR ALONG THE MASS EAST COASTLINE IN RAIN/SNOW
SHOWERS.
TUESDAY NIGHT INTO WEDNESDAY...MODERATE CONFIDENCE. CONDITIONS WILL
BE DETERIORATING AS HEAVY DOWNPOURS...ISO THUNDER AND GUSTY SOUTHERLY
WINDS MOVE INTO THE REGION BY WEDNESDAY. COULD SEE MVFR TO IFR
CONDITIONS IN CIGS AND VSBYS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH SUNDAY/...HIGH CONFIDENCE.
HIGH PRESSURE ACROSS QUEBEC WILL RESULT IN PERSISTENT NORTHEAST
WINDS ACROSS THE WATERS THROUGH THE WEEKEND. WIND GUSTS UP TO 20
KNOTS WITH SEAS BETWEEN 2 AND 4 FEET ARE EXPECTED FOR MOST
WATERS...SO NO HEADLINES PLANNED. THERE IS A LOW PROBABILITY THAT A
BRIEF SURGE OF NORTHEAST WIND GUSTS NEAR 25 KNOTS WITH MARGINAL 5
FOOT SEAS COULD AFFECT OUR NORTHERN WATERS LATE TONIGHT INTO SUN
MORNING...BUT NOT CONFIDENT ENOUGH TO ISSUE ANY HEADLINES AT THIS
POINT.
OUTLOOK...SUNDAY NIGHT INTO WEDNESDAY...MODERATE TO HIGH
CONFIDENCE.
SUNDAY INTO MONDAY. CONTINUOUS NORTHEAST FLOW WILL KEEP SEAS CHOPPY.
LINGERING NORTHEAST SWELL MAY BUMP SEAS ABOVE 5FT ESP ACROSS THE
NORTHEASTERN WATERS. SCA MAY BE NEEDED...BUT LOWER CONFIDENCE.
TUESDAY INTO WEDNESDAY...NE WINDS WILL INCREASE...GUSTING TO 30 KT
TUE THEN SHIFT TO SE GUSTING TO 30-35 KT WED...HIGHEST ON THE OUTER
WATERS. SEAS BUILD UP TO 7-11 FT BY WED. GALES WILL BE NEEDED.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL OCCUR TUESDAY THROUGH THURSDAY. BREAKING
IT DOWN...ON TUESDAY HIGH TIDE AT BOSTON WILL BE 11.6 FT. THERE WILL
BE ONSHORE FLOW DURING THIS HIGH TIDE ALLOWING FOR MINOR SPLASHOVER.
IF WIND GUSTS INCREASE THEN COULD POSSIBLE SEE MINOR COASTAL
FLOODING.
ON WEDNESDAY...WINDS WILL SWITCH TO A MORE SOUTHEASTERLY FLOW DURING
THE DAY AND INCREASE QUICKLY FROM APPROACHING SYSTEM AND DESCENT
PRESSURE FALLS. WEDNESDAY AFTERNOON HIGH TIDE IN BOSTON IS 11.7 FT
AND WITH ANY STRENGTH ON THE EASTERLY WIND FLOW WILL PUSH THE TIDE
OVER. RIGHT NOW BELIEVE MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
EAST COASTLINE. HOWEVER WEDNESDAY EVENING...THE WIND GOES IN A MORE
SOUTHERLY DIRECTION AND HIGH TIDE IN PROVIDENCE WILL BE 5.2 FT. 925
MB LLJ STRENGTHENS TO 50-60 KTS WHICH COULD PUSH A DESCENT SURGE UP
ALONG THE SOUTH COAST DURING THE TIME OF HIGH TIDE. THINKING THAT
MINOR COASTAL FLOODING COULD OCCUR BUT CANNOT RULE OUT MODERATE
ALONG THE SOUTH COAST...ESP IF LLJ STRENGTHENS EVEN MORE.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK/DUNTEN/RLG
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
539 AM CST SAT DEC 20 2014
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM CST SAT DEC 20 2014
WEAK SHORTWAVE TROUGHS ARE PERIODICALLY PROGRESSING ACROSS THE
PLAINS FROM THE WEST. ONE SUCH MINOR WAVE WILL MOVE ACROSS THE
SOUTHERN PLAINS BY TONIGHT. HOWEVER, LEE TROUGHING IN RESPONSE TO
WESTERLY FLOW AT MID LEVELS SEEMS TO BE THE DOMINANT FEATURE THAT
IS AFFECTING THE LOW LEVEL WIND FIELD. EARLY MORNING SATELLITE AND
SURFACE OBSERVATIONS INDICATE LOW STRATUS ACROSS THE SOUTHERN
PLAINS AS FAR NORTH AS PERRYTON AND MEDICINE LODGE. AS SURFACE
TROUGHING ENCOURAGES SOUTHERLY WINDS TODAY, THIS LOW LEVEL
MOISTURE SHOULD PROGRESS NORTHWARD INTO LOCATIONS FROM DODGE CITY
SOUTH AND EAST TO THE OKLAHOMA BORDER. THE NAM HAS A CHARACTERISTIC
BIAS OF BEING TOO DRY AND WARM AT LOWER LEVELS IN CASES SUCH AS
THIS. THE HRRR AND RAP ARE COOLER AND INDICATE LOW CLOUD COVER
PROGRESSING AS FAR NORTH AS DODGE CITY BY EARLY AFTERNOON. CLOUD
COVER WILL TEND TO KEEP DIURNAL RANGES LOWER AND TEMPERATURES
COOLER IN THE AFTERNOON. AS AN EXAMPLE, THE TEMPERATURE AT GAGE,
OKLAHOMA STAYED 41F FROM FRIDAY AFTERNOON THROUGH EARLY THIS
MORNING AS A RESULT OF THE STRATUS. TEMPERATURES SHOULD BE WARMER
TODAY IN LOCATIONS SUCH AS SCOTT CITY AND WAKEENEY WHERE PLENTY OF
SUNSHINE IS EXPECTED. LOW STRATUS WILL PERSIST OR INCREASE IN
AREAL COVERAGE TONIGHT, AND FOG IS POSSIBLE ON THE WESTERN
PERIPHERY OF THE CLOUD SHIELD, SOME OF WHICH COULD BE LOCALLY
DENSE. THE CLOUD COVER AND HIGHER DEWPOINTS OUGHT TO KEEP
TEMPERATURES FROM FALLING A LOT TONIGHT, EXCEPT FOR WEST CENTRAL
KANSAS WHERE LESS CLOUD COVER IS EXPECTED.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 412 AM CST SAT DEC 20 2014
AT THE BEGINNING OF THE EXTENDED PERIOD ON SUNDAY, A SHORTWAVE
TROUGH WILL BE MOVING OUT OF THE WESTERN HIGH PLAINS ACROSS KANSAS.
A SURFACE TROUGH OVER EASTERN COLORADO COULD MOVE OUT INTO FAR
WESTERN KANSAS DURING THE DAY. LOW LEVEL WINDS WILL TAKE ON A MORE
SOUTHWESTERLY DOWNSLOPE FLOW COMPONENT DURING THE DAY IN THAT AREA
AND HELP BOOST TEMPERATURES INTO THE MID/UPPER 50S. FARTHER EAST
ACROSS SOUTHWEST INTO SOUTH CENTRAL KANSAS LOW STRATUS WILL LIKELY
BE IN PLACE DUE TO CONTINUED MOIST SOUTHERLY FLOW. WHILE THE STRATUS
WILL LIKELY ERODE SOMEWHAT DURING THE DAY, AREAS AROUND SOUTH
CENTRAL KANSAS WILL LIKELY STAY SOCKED IN WITH LOW CLOUDS.
BY MONDAY MORNING, A STRENGTHENING UPPER LEVEL SHORTWAVE TROUGH WILL
MOVE FROM SOUTHWEST CANADA AND DEVELOP INTO A CLOSED LOW OVER
SOUTHEAST SOUTH DAKOTA. AS THIS LOW CONTINUES INTO THE MIDWEST
STATES DURING THE DAY, A SHORTWAVE TROUGH WILL DIG SOUTH ACROSS THE
EASTERN ROCKIES AND ADJACENT HIGH PLAINS AND PUSH A COLD FRONT SOUTH
ACROSS WESTERN KANSAS. THE MODELS CONTINUE TO SHOW PRECIPITATION
DEVELOPING ALONG THE FRONT ALONG WITH SOME LINGERING UPSLOPE
PRECIPITATION OVER EASTERN COLORADO AND FAR WESTERN KANSAS DURING
THE DAY. TEMPERATURE PROFILES CONTINUE TO SUGGEST THAT PRECIPITATION
SHOULD MAINLY BE LIQUID. BY MONDAY NIGHT THE MAIN UPPER LEVEL ENERGY
WITH THE WAVE DROPS INTO NEW MEXICO AND WEST TEXAS. FARTHER NORTH
THE TROUGH SWINGS OUT ACROSS THE HIGH PLAINS. THIS COULD BRING A
FEW FLURRIES TO WEST CENTRAL KANSAS LATE MONDAY NIGHT. WILL CARRY
SOME SLIGHT CHANCE POPS FOR THIS.
THE MODELS CONTINUE TO SHOW UNIDIRECTIONAL NORTHERLY FLOW DEVELOPING
THROUGH THE LOWER TO MIDDLE LEVELS OVER THE HIGH PLAINS LATE MONDAY
NIGHT AND CONTINUING INTO TUESDAY. BLUSTERY CONDITIONS WILL DEVELOP
BY EARLY MORNING TUESDAY AND CONTINUE THROUGH THE DAY. SOME 40 TO 45
MPH GUSTS WILL BE POSSIBLE DURING THE DAY.
UPPER LEVEL RIDGING WILL DEVELOP OVER THE CENTRAL HIGH PLAINS
THROUGH THE MIDDLE PART OF THE WEEK AS THE EARLY WEEK SYSTEM MOVES
INTO THE EASTERN CONUS AND ANOTHER WAVE DROPS INTO THE NORTHERN
ROCKIES. THIS NEXT WAVE COULD BRING RAIN OR SNOW TO WESTERN KANSAS
BY AS EARLY AS CHRISTMAS DAY. THE GLOBAL MODELS CONTINUE TO SHOW
SIGNIFICANT RUN TO RUN VARIABILITY WITH THIS WAVE, HOWEVER. AFTER
COLLABORATING WITH SOME OF THE SURROUNDING OFFICES, HAVE INTRODUCED
SOME SMALL POPS FOR RAIN OR SNOW TO CENTRAL KANSAS NEXT THURSDAY
NIGHT AND FRIDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 539 AM CST SAT DEC 20 2014
MVFR VSBYS WILL IMPROVE TO VFR AT GCK, DDC, AD HYS BY 15Z AS
TEMPERATURES BEGIN TO WARM. MVFR CIGS OVER THE OKLAHOMA AND TEXAS
PANHANDLES COULD MOVE UP INTO SOUTH CENTRAL AND PARTS OF SOUTHWEST
KANSAS TODAY. IT IS NOT CERTAIN THAT THESE LOW CIGS WILL MOVE OVER
DODGE CITY SO WILL MAINTAIN A LOW LEVEL SCATTERED CLOUD DECK AT
THIS TIME. THERE IS SOME POTENTIAL FOR MVFR TO IFR CONDITIONS IN
LOW CLOUDS AND MIST TO REDEVELOP TOWARD THE END OF THE TAF PERIOD.
WILL LEAVE OUT OF THIS TAF UPDATE FOR NOW BUT LATER UPDATES MAY
INCLUDE IT IF IT APPEARS MORE LIKELY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 44 33 52 34 / 0 0 0 10
GCK 50 27 55 32 / 0 0 0 10
EHA 51 27 57 34 / 0 0 0 20
LBL 47 31 56 33 / 0 0 0 10
HYS 49 31 50 34 / 0 0 0 10
P28 46 37 49 36 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...FINCH
LONG TERM...GERARD
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
413 AM CST SAT DEC 20 2014
...UPDATED LONG TERM DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM CST SAT DEC 20 2014
WEAK SHORTWAVE TROUGHS ARE PERIODICALLY PROGRESSING ACROSS THE
PLAINS FROM THE WEST. ONE SUCH MINOR WAVE WILL MOVE ACROSS THE
SOUTHERN PLAINS BY TONIGHT. HOWEVER, LEE TROUGHING IN RESPONSE TO
WESTERLY FLOW AT MID LEVELS SEEMS TO BE THE DOMINANT FEATURE THAT
IS AFFECTING THE LOW LEVEL WIND FIELD. EARLY MORNING SATELLITE AND
SURFACE OBSERVATIONS INDICATE LOW STRATUS ACROSS THE SOUTHERN
PLAINS AS FAR NORTH AS PERRYTON AND MEDICINE LODGE. AS SURFACE
TROUGHING ENCOURAGES SOUTHERLY WINDS TODAY, THIS LOW LEVEL
MOISTURE SHOULD PROGRESS NORTHWARD INTO LOCATIONS FROM DODGE CITY
SOUTH AND EAST TO THE OKLAHOMA BORDER. THE NAM HAS A CHARACTERISTIC
BIAS OF BEING TOO DRY AND WARM AT LOWER LEVELS IN CASES SUCH AS
THIS. THE HRRR AND RAP ARE COOLER AND INDICATE LOW CLOUD COVER
PROGRESSING AS FAR NORTH AS DODGE CITY BY EARLY AFTERNOON. CLOUD
COVER WILL TEND TO KEEP DIURNAL RANGES LOWER AND TEMPERATURES
COOLER IN THE AFTERNOON. AS AN EXAMPLE, THE TEMPERATURE AT GAGE,
OKLAHOMA STAYED 41F FROM FRIDAY AFTERNOON THROUGH EARLY THIS
MORNING AS A RESULT OF THE STRATUS. TEMPERATURES SHOULD BE WARMER
TODAY IN LOCATIONS SUCH AS SCOTT CITY AND WAKEENEY WHERE PLENTY OF
SUNSHINE IS EXPECTED. LOW STRATUS WILL PERSIST OR INCREASE IN
AREAL COVERAGE TONIGHT, AND FOG IS POSSIBLE ON THE WESTERN
PERIPHERY OF THE CLOUD SHIELD, SOME OF WHICH COULD BE LOCALLY
DENSE. THE CLOUD COVER AND HIGHER DEWPOINTS OUGHT TO KEEP
TEMPERATURES FROM FALLING A LOT TONIGHT, EXCEPT FOR WEST CENTRAL
KANSAS WHERE LESS CLOUD COVER IS EXPECTED.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 412 AM CST SAT DEC 20 2014
AT THE BEGINNING OF THE EXTENDED PERIOD ON SUNDAY, A SHORTWAVE
TROUGH WILL BE MOVING OUT OF THE WESTERN HIGH PLAINS ACROSS KANSAS.
A SURFACE TROUGH OVER EASTERN COLORADO COULD MOVE OUT INTO FAR
WESTERN KANSAS DURING THE DAY. LOW LEVEL WINDS WILL TAKE ON A MORE
SOUTHWESTERLY DOWNSLOPE FLOW COMPONENT DURING THE DAY IN THAT AREA
AND HELP BOOST TEMPERATURES INTO THE MID/UPPER 50S. FARTHER EAST
ACROSS SOUTHWEST INTO SOUTH CENTRAL KANSAS LOW STRATUS WILL LIKELY
BE IN PLACE DUE TO CONTINUED MOIST SOUTHERLY FLOW. WHILE THE STRATUS
WILL LIKELY ERODE SOMEWHAT DURING THE DAY, AREAS AROUND SOUTH
CENTRAL KANSAS WILL LIKELY STAY SOCKED IN WITH LOW CLOUDS.
BY MONDAY MORNING, A STRENGTHENING UPPER LEVEL SHORTWAVE TROUGH WILL
MOVE FROM SOUTHWEST CANADA AND DEVELOP INTO A CLOSED LOW OVER
SOUTHEAST SOUTH DAKOTA. AS THIS LOW CONTINUES INTO THE MIDWEST
STATES DURING THE DAY, A SHORTWAVE TROUGH WILL DIG SOUTH ACROSS THE
EASTERN ROCKIES AND ADJACENT HIGH PLAINS AND PUSH A COLD FRONT SOUTH
ACROSS WESTERN KANSAS. THE MODELS CONTINUE TO SHOW PRECIPITATION
DEVELOPING ALONG THE FRONT ALONG WITH SOME LINGERING UPSLOPE
PRECIPITATION OVER EASTERN COLORADO AND FAR WESTERN KANSAS DURING
THE DAY. TEMPERATURE PROFILES CONTINUE TO SUGGEST THAT PRECIPITATION
SHOULD MAINLY BE LIQUID. BY MONDAY NIGHT THE MAIN UPPER LEVEL ENERGY
WITH THE WAVE DROPS INTO NEW MEXICO AND WEST TEXAS. FARTHER NORTH
THE TROUGH SWINGS OUT ACROSS THE HIGH PLAINS. THIS COULD BRING A
FEW FLURRIES TO WEST CENTRAL KANSAS LATE MONDAY NIGHT. WILL CARRY
SOME SLIGHT CHANCE POPS FOR THIS.
THE MODELS CONTINUE TO SHOW UNIDIRECTIONAL NORTHERLY FLOW DEVELOPING
THROUGH THE LOWER TO MIDDLE LEVELS OVER THE HIGH PLAINS LATE MONDAY
NIGHT AND CONTINUING INTO TUESDAY. BLUSTERY CONDITIONS WILL DEVELOP
BY EARLY MORNING TUESDAY AND CONTINUE THROUGH THE DAY. SOME 40 TO 45
MPH GUSTS WILL BE POSSIBLE DURING THE DAY.
UPPER LEVEL RIDGING WILL DEVELOP OVER THE CENTRAL HIGH PLAINS
THROUGH THE MIDDLE PART OF THE WEEK AS THE EARLY WEEK SYSTEM MOVES
INTO THE EASTERN CONUS AND ANOTHER WAVE DROPS INTO THE NORTHERN
ROCKIES. THIS NEXT WAVE COULD BRING RAIN OR SNOW TO WESTERN KANSAS
BY AS EARLY AS CHRISTMAS DAY. THE GLOBAL MODELS CONTINUE TO SHOW
SIGNIFICANT RUN TO RUN VARIABILITY WITH THIS WAVE, HOWEVER. AFTER
COLLABORATING WITH SOME OF THE SURROUNDING OFFICES, HAVE INTRODUCED
SOME SMALL POPS FOR RAIN OR SNOW TO CENTRAL KANSAS NEXT THURSDAY
NIGHT AND FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1155 PM CST FRI DEC 19 2014
WEAK SURFACE LEE TROUGHING WILL PERSIST THROUGH THE PERIOD ON THE
HIGH PLAINS. LIGHT SOUTHWESTERLY WINDS AT 5 TO 10 KTS WILL
CONTINUE THROUGH THE TAF PERIOD BEFORE BECOMING MORE SOUTHERLY
AFTER 18Z SATURDAY. MVFR TO VFR CONDITIONS WILL PERSIST THROUGH
12Z BEFORE BECOMING VFR WITH DAYTIME HEATING BY 14-15Z. THERE IS A
CHANCE THAT STRATUS OVER THE TEXAS PANHANDLE COULD PROGRESS INTO
KDDC BY 18-19Z, WITH CIGS IN THE LOW MVFR CATEGORY GIVEN THE
SOUTHERLY WINDS TODAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 52 33 52 34 / 0 0 0 10
GCK 52 27 55 32 / 0 0 0 10
EHA 51 27 57 34 / 0 0 0 20
LBL 52 31 56 33 / 0 0 0 10
HYS 52 31 50 34 / 0 0 0 10
P28 52 37 49 36 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...FINCH
LONG TERM...GERARD
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1028 AM EST Sat Dec 20 2014
...Forecast Update...
Issued at 1025 AM EST Sat Dec 20 2014
Main forcing that brought light snow to the area this morning has
moved off into Ohio, so the remainder of the day is expected to be
dry. The afternoon forecast is largely on track, though the
challenge is cloud cover. Models are not handling the low/mid level
moisture very well at all as there is a large, although thin, deck
of clouds upstream. The HRRR seems to have a somewhat decent handle
on the current situation, so trended the forecast in that direction,
but went more pessimistic given current satellite and low sun angle
this time of year. This gives more of an cloudy/overcast afternoon
to the area, though there could be some breaks along/south of the KY
parkways. As a result of the increased clouds, lowered high
temperatures a degree or two.
Issued at 815 AM EST Sat Dec 20 2014
Radar returns, automated observations and spotter reports confirm
that the light snow continues across the Louisville metro area and
points north and east. With temperatures remaining in the upper 20s
to around 30, slick spots on untreated roads, particularly bridges
and overpasses could develop. Adjusted forecast grids and continued
SPS for portions of the area.
The main forcing for this activity is an upper level shortwave and
this is rapidly moving out of the area, so I`m expecting this
activity to end west to east over the next few hours.
Issued at 542 AM EST Sat Dec 20 2014
Light snow continues across portions of southern IN and north
central KY this morning. Some light accumulations have been reported
on cars and area roadways this morning for this activity. Updated
the grids to reflect current radar trends and issued an SPS talking
about slick spots. Still think most of this activity should move out
of the area by around sunrise.
.SHORT TERM (Now through Sunday)...
Issued at 307 AM EST Sat Dec 20 2014
Some light radar returns continue to show up across southern Indiana
and portions of north central Kentucky this morning associated with
a weak PV anomaly. Some light snow may reach the ground under
the strongest echoes, as it did here at the office. However, the
most that is expected is a very light dusting on elevated surfaces.
This activity will continue to push off to the northeast over the
next few hours and should be out of the area by sunrise.
Clouds will stick around for much of the day but should begin to
clear by late afternoon into the evening. High pressure ridging in
from the northeast will keep the area dry through Sunday. Highs
today will range from the upper 30s in the north to the mid 40s in
the south. Tomorrow will be a bit warmer with highs ranging from the
mid 40s to around 50. Lows tonight will be in the mid to upper 20s.
.LONG TERM (Sunday night through Friday)...
Issued at 332 AM EST Sat Dec 20 2014
Sunday night through Tuesday Night...
Medium range deterministic guidance continues to be in good
agreement with the overall pattern as head into the late weekend and
into early next week. The upper pattern at the beginning of the
period will feature a broad trough over the inter-mountain west with
ridging along both coasts. This will place the Ohio Valley in a
broad southwesterly flow aloft early in the period. As we move into
Monday, the multi-model consensus continues to suggest that the
ridge over the eastern Pacific will build northward into western
Canada. As this occurs, the Pacific jet will pound it`s way into
Canada and then drop into the Plains. This will lead to the broad
trough over the inter-mountain west to deepen and close off by
Monday afternoon. The trough is expected to deepen further
resulting in cyclogenesis over Texas. This surface low will deepen
as well as it heads NE into the Ohio Valley by late Tuesday night.
We`ll see dry conditions initially in our region at the beginning of
the period, but rain chances will quickly ramp up on Monday as the
broad southwesterly flow pushes quite a bit of moisture up into our
region. Precipitable water amounts of nearly 1.25 inches look to
be in our vicinity by Tuesday afternoon which is +2 standard
deviations above normal. Thus, some of the rainfall could be heavy
at times from Monday afternoon through Tuesday night. With us
remaining in the southwest flow, temperatures will be rather mild
through this portion of the forecast period. Lows Sunday night will
drop into the lower-middle 30s with highs on Monday warming into the
lower 50s in the north with lower-middle 50s across the south.
Temps will cool off just a bit Monday night with lows mainly in the
lower-mid 40s. Tuesday look like to be the mildest day of the
period with highs pushing into the upper 50s. Given the deepening
system and broad southwesterly flow, these numbers for Tuesday are
probably too conservative, and we may see some lower 60 degree
readings down across southern KY. Some colder air will start to
wrap in late Tuesday night with lows crashing into the mid 30s in
the west with mid-upper 40s in the east.
Wednesday through Friday...
...Very Active Period of Weather Likely for Christmas Eve and into
early Christmas Day...
Latest long term model guidance has been trending westward with the
overall track of the surface low. The Canadian GEM has been leading
the pack on the westward shift, and the Euro and GFS solutions have
now trended more west with the low. By Wednesday morning, low
pressure should be in east-central Kentucky with a rather large
precipitation shield encompassing much of the region. The pressure
gradient will rapidly increase during the morning hours with
sustained winds ramping up to 10-20 MPH by the early afternoon
hours. The surface low is expected to rapidly intensify during the
afternoon as it races from east-central KY into western Ontario.
Based on the multi-model consensus, we could see the system deepen
by 20+ millibars within a 24 hour period. As the low pulls away
from the region, we will see winds shift to the northwest and remain
quite elevated with sustained winds of 10-20 MPH and gusts up to
35-40 MPH. Thermal profiles are slightly warmer during the day
suggestive that much of the precipitation behind the system will be
in the form of rain. Highs early in the day will be in the upper
30s in the west to the lower-mid 40s in the east and then fall
during the afternoon.
By Christmas Eve, we will see temperature profiles crash from west
to east resulting in a quick change over to snow showers. Very
blustery and cold conditions look increasingly likely for Christmas
eve with widespread snow shower activity in progress across the
region. Model soundings continue to show very steep low-level lapse
rates with plenty of moisture in the ice crystal producing layer.
Thus, some snow showers may capable of producing moderate snow at
times during the evening. While temperatures drop to near freezing,
there will be an opportunity for some minor accumulations. Given
the relatively warm ground and recent rainfall, any snowfall
accumulation will be dependent upon the intensity of the snow
showers.
The models continue to trend a little faster with the moisture pull
off to the northeast early Christmas morning. Current thinking is
that we`ll still have some snow shower activity past midnight, but
then rapidly diminish by sunrise. The flow aloft looks to quickly
revert back to zonal flow which will likely push some drier air into
the region resulting clearing skies during the day. Temperatures
will be challenging depending on how fast skies clear. The clear
trend in the models has been warmer, so we have adjusted
temperatures slightly upwards with highs in the upper 30s in the
north to the lower-mid 40s across the south.
Generally dry conditions are expected for Friday. However, another
quick moving system will be pushing into the region by the late part
of the period. Temps on Friday may be quite mild within the return
flow regime with upper 40s to lower 50s being possible. A period of
rain showers looks increasingly likely for Friday night with colder
conditions returning by Saturday.
&&
.AVIATION (12Z TAF Update)...
Issued at 550 AM EST Sat Dec 20 2014
Some very light snow or flurries may move through SDF and LEX over
the next couple of hours. Thereafter, dry conditions are expected
through the TAF period. Skies will be cloudy through most of the day
but ceilings should remain mainly VFR. Clouds may begin to scatter
out late this afternoon into this evening. Winds will be light and
out of the north today. They will become variable to calm overnight.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........ZBT
Short Term.....EER
Long Term......MJ
Aviation.......EER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
654 AM EST SAT DEC 20 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 434 AM EST SAT DEC 20 2014
WV LOOP AND 00Z RAOBS SHOW A LARGE SCALE ZONAL FLOW...BUT THERE IS
EMBEDDED AMPLIFICATION. TROUGHING WAS AS CLOSE BY AS NORTHERN PLAINS
AND MINNESOTA THIS MORNING. PRIMARY PV ANAMOLIES/SHORTWAVES WITHIN
TROUGH WERE OVER FAR NORTHWEST ONTARIO AND OVER WESTERN IOWA. WEAK
SFC TROUGH NOTED OVER WESTERN MINNESOTA TOO...WHILE SFC RIDGING
EXTENDING OUT OF QUEBEC WAS STILL MAIN FEATURE OVER GREAT LAKES. THE
ONTARIO WAVE AND WEAK WARM AIR ADVECTION AHEAD OF THE MINNESOTA
TROUGH AND UPSLOPE LOW-LEVEL FLOW IS SUPPORTING LGT WINTRY MIX OF
SNOW AND FREEZING DRIZZLE OVER NORTHERN MINNESOTA THIS MORNING. ONLY
AFFECT FM ONTARIO SHORTWAVE OVER UPR MICHIGAN IS BATCH OF MID CLOUDS
OVER WEST HALF OF CWA. NO PRECIP THROUGH. ONLY WEATHER OF NOTE IN
THE CWA THIS MORNING IS PATCHY DENSE FOG OVER CNTRL CWA...VCNTY OF
IMT TO SAW.
ONTARIO WAVE MOVES LITTLE EASTWARD TODAY AS ANOTHER SHORTWAVE
CURRENTLY OVER MT TRIES TO CATCH UP WITH IT. THUS...SFC TROUGH AND
WARM AIR ADVECTION STAY MAINLY OVER MN. RAP SHOWS WEAK LIFT TRYING
TO IMPACT KEWEENAW THIS MORNING INTO EARLY AFTN...BUT IT LOOKS MUCH
DRIER THAN IT IS UPSTREAM OVER MN WHERE PRECIP IN OCCURRING THIS
MORNING...SO NOT EXPECTING ANY PRECIP OUT OF THIS FOR OUR AREA. LOW
CLOUDS OVER NW WI AND WEST UPR MICHIGAN GRADUALLY EASE
EASTWARD...BUT A FEW SPOTS IN EAST HALF OF CWA MAY STAY CLEAR OF THE
LOW CLOUDS ALL DAY. TOUGH TO SAY EXACTLY WHERE THOUGH AS THERE ARE
DIFFERENT AREAS OF CLOUDS AFFECTING THE AREA AND MODELS FORECASTING
OF THEM IS ONLY FAIR. FOR TEMPS...WENT AT OR 1-2 DEGREES ABOVE
FRIDAY READINGS AS 925MB TEMPS WARM SLIGHTLY COMPARED TO FRIDAY.
WHERE SUNSHINE CAN PERSIST INTO THE AFTN...TEMPS COULD BUMP INTO THE
MID 30S. BEST SHOT AT THAT WOULD BE EAST CENTRAL CWA...VCTY OF
MUNISING AND GRAND MARAIS. FARTHER WEST...CLOUDS WILL HOLD TEMPS
DOWN OVER INTERIOR WEST TO UPR 20S. INTO THIS EVENING...EXPECT LOW
CLOUDS /HIGHER 925MB-850MB RH/ TO BE OVER WEST HALF OF CWA AND ALSO
THE FAR EAST CWA. EVENTUALLY THOUGH...CLOUDS SHOULD FILL IN OVER ALL
CWA. UNTIL THAT OCCURS...TEMPS FOR INTERIOR CNTRL CWA OR AT LEAST
PORTIONS OF THESE AREAS MAY DROP OFF QUICKLY. CLOSEST MODEL TO
INCICATE THAT WAS BIAS CORRECTED NAM MOS. TWEAKED DOWN EVEN FURTHER
THOUGH /LOW TEENS/ SEEING HOW MUCH TEMPS FELL EARLY THIS MORNING
WHERE SKIES WERE CLEAR. ALSO WILL ADD FOG TO THOSE AREAS SINCE THESE
TEMPS WILL BE WELL BELOW THE EXPECTED AFTN DWPNTS. WHERE CLOUDS STAY
IN ALL NIGHT...MIN TEMPS LIKELY STAY ABOVE 20 DEGREES.
SOUNDINGS FM NAM AND GFS INDICATE INCREASING SUB 950MB MOISTURE
LATE TONIGHT FM THE SOUTH AND WITH UPSLOPE SOUTH FLOW OVER CNTRL
CWA COULD SEE PATCHY FREEZING DRIZZLE IMT TO NEGAUNEE. NOT MUCH UVM
SHOWN ON THE SOUNDINGS THOUGH...SO LEFT IT OUT OF GRIDS ATTM.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 434 AM EST SAT DEC 20 2014
MAIN FOCUS FOR THE LONGER TERM REMAINS THE POTENTIAL FOR SOME SN OR
MIXED PCPN IN THE MON INTO XMAS PERIOD ASSOCIATED WITH A DEEPENING
UPR TROF IN THE CENTRAL CONUS AS A SERIES OF SHRTWVS RIDING OVER A
MEAN RDG ALONG THE W COAST DIG INTO THE PLAINS. THE STRONGEST OF
THESE DISTURBANCE IS NOW OVER THE NE PACIFIC OCEAN. ALTHOUGH THE
MODELS ARE COMING INTO BETTER AGREEMENT ON WARMER LLVL TEMPS IN THE
TUE/WED TIME AND ON THE DEVELOPMENT OF A LO PRES IN THE LO/MID MS
RIVER VALLEY THAT WL TRACK SOMEWHERE NEAR THE CENTRAL GREAT LKS ON
WED AND INTO CANADA ON XMAS DAY...THERE ARE STILL SOME SIGNIFICANT
DIFFERENCES ON THE DETAILS OF HOW THE INTERACTION/PHASING BTWN THESE
SEPARATE DISTURBANCES THAT ARE STILL OVER THE DATA POOR PACIFIC WL
IMPACT THE SFC LO TRACK AND UPR MI.
SUN/SUN NIGHT...AS LLVL S WIND BTWN DEPARTING HI PRES IN SE CANADA
AND FALLING MSLP TO THE W ADVECT MOISTER LLVL AIR INTO THE CWA...
OPTED TO INCLUCE SOME FREEZING DZ OVER THE SCENTRAL IN THE MRNG
WHERE LLVL WIND WL UPSLOPE OFF LK MI. THEN OPERATIONAL MODELS SHOW A
SHRTWV MOVING E FM THE NRN PLAINS ACROSS THE NW GREAT LKS AND INTO
NW ONTARIO BY 12Z MON... BRINGING A PERIOD OF DEEP LYR QVECTOR CNVGC
ASSOCIATED WITH SOME DPVA AND ISENTROPIC ASCENT BEST DEPICTED ON THE
285-290K SFCS /ABOUT H85-75/ IN THE STRONGER SSW FLOW BTWN HI PRES
OVER THE CNDN MARITIMES AND LO PRES IN THE NRN PLAINS. ARRIVAL OF
THE DEEPER MSTR SHOULD END THE FREEZING DZ. THE BULK OF THE GUIDANCE
INDICATES THE ACCOMPANYING SN WL BEGIN OVER THE SCENTRAL SUN AFTN
AND THEN OVERSPREAD THE REST OF THE FA THRU SUN NGT. THE NAM SHOWS
THE HIEST QPF UP TO 0.25-0.30 INCH OVER THE SCENTRAL...WHERE THE
NEAR SFC SSE FLOW WL UPSLOPE OFF LK MI AND H85 MSTR CNVGC IS A BIT
SHARPER. THE GFS ON THE OTHER HAND SHIFTS THE HIER QPF TO OVER THE
NW CWA LATE AT NGT. GIVEN THE GREATER CONSISTENCY OF THE NAM WITH
PREVIOUS FCST GUIDANCE...TENDED TOWARD THAT MODEL SCENARIO. WL BUMP
POPS UP TO LIKELY OVER THE SCENTRAL CENTERED ARND SUN EVNG WHEN THE
FORCING WL BE GREATEST. THERE COULD BE A FEW INCHES OF SN ACCUM IN
THIS AREA AS WELL. SSW FLOW UP THE LENGTH OF LK MI MAY SUPPORT SOME
HIER POPS OVER THE E...BUT MARGINAL CHILL OF THE AIRMASS FOR LK
ENHANCEMENT WITH H85 TEMPS RISING TO -5C BY 00Z MON SHOULD LIMIT THE
POTENTIAL FOR A SGNFT IMPACT. TEMPS WL REMAIN ABOVE NORMAL...
ESPECIALLY ON SUN NGT WITH CLD COVER AND A STEADY S WIND GREATLY
LIMITING THE DIURNAL TEMP FALL.
MON...FOLLOWING THE EXIT OF THE SHRTWV INTO NW ONTARIO ON MON AND
THE ARRIVAL OF SOME MID LVL DRYING ASSOCIATED WITH A SHRTWV RDG AXIS
ROTATING NEWD THRU THE NW GREAT LKS TO THE E OF THE DEEPENING UPR
TROF IN THE PLAINS...EXPECT DIMINISHED POPS. BUT PERSISTENT WAA IN
THE DEEP S FLOW BTWN LO PRES SLIDING SEWD THRU THE NRN PLAINS AND HI
PRES OVER THE CNDN MARITIMES WL CAUSE LOTS OF CLDS AND CONTINUED LO
CHC POPS. AS THE LLVLS WARM INTO THE 30S ESPECIALLY NEAR THE WARMING
INFLUENCE OF THE GREAT LKS...LIGHT PCPN MAY INCLUDE A MIX OF RA AND
SN.
MON NGT/TUE...THE 00Z GFS REMAINS CONSISTENT ON SHOWING A CLOSED H5
LO WITHIN THE DEEPENING CENTRAL CONUS TROF/DEEPER SFC LO PRES MOVING
INTO THE UPR LKS DURING THIS TIME ALONG WITH HIER H85 TEMPS UP TO
ARND 0C. THE 12Z/00Z ECMWF MODELS ON THE OTHER HAND HOLD THE CLOSED
H5 LO/SFC LO FARTHER TO THE SW...WITH A SLOWER ARRIVAL OF DEEPER
MSTR AND LOWER H85 TEMPS. BOTH MODELS SHOW DISTURBANCES DIGGING SEWD
TO THE E OF THE UPR RDG ACROSS THE W DEEPENING THE PLAINS TROF.
SINCE THIS GREATER FORCING INTO THE SRN PLAINS SHOULD TEND TO HOLD
THE CLOSED LO THE SW...WL TEND TOWARD THE 12Z ECMWF SCENARIO. THIS
MODEL SHOWS DEEPER MSTR ARRIVING LATE MON NGT AND PERSISTING THRU
TUE AS THE WEAKER SHRTWV LIFTS NEWD AWAY FM CLOSED LO TO THE SW.
ALTHOUGH THE 00Z ECMWF H85 TEMPS ARE LOWER THAN FCST BY THE GFS...
THE FCST H100-85 THKNS IS ONLY A BIT LOWER THAN THE GFS FCST. A LOOK
AT THE 00Z ECMWF FCST SDNGS SHOW A TREND TOWARD A WARMER NEAR SFC
LYR THAT WOULD SUPPORT MORE RA...AS SHOWN BY RECENT GFS RUNS. SO
TENDED TO RAISE FCST TEMPS AND INCLUDE A GREATER AREA OF AT LEAST A
MIX WITH RA. THE FCST SDNGS FM NEITHER MODEL SHOW AN ELEVATED WARM
LYR...SO THE PCPN SHOULD BE RA OR SN. ADDED A MENTION OF SOME FOG
DURING THE MON NIGHT/TUE TIME TO REFLECT THE RA/HIER TEMPS AND
DEWPTS OVER A MELTING SN PACK AT MANY LOCATIONS THAT UPSLOPE OFF LK
MI IN THE EXPECTED LLVL SE FLOW. THIS MIXED PCPN WL TEND TO DIMINISH
ON TUE NGT AS SOME UPR DRYING FOLLOWS THE SHRTWV EXITING NNEWD INTO
ONTARIO.
WED/THU...THE LONGER RANGE MODELS ARE BEGINNING TO COME INTO BETTER
AGREEMENT ON SHOWING A SECOND LO DVLPG IN THE LOWER TO MID MS RIVER
VALLEY ON TUE AT THE SRN END OF THE DEEPING CENTRAL CONUS TROF AND
THEN MOVING NNE INTO THE CENTRAL GREAT LKS ON WED AND THEN INTO ERN
ONTARIO ON XMAS DAY WHILE DEEPENING SIGNIFICANTLY AS THE UPR TROF
TAKES ON A MORE NEGATIVE TILT. NOT SURPRISINGLY...THE EXACT TRACK OF
THE SFC LO...WHICH WL MAKE A SGNFT DIFFERNCE ON PTYPE/PCPN TOTALS
OVER UPR MI...IS STILL UNCERTAIN. THE 00Z GFS INDICATES A FARTHER W
TRACK ACROSS THE ERN U.P. THAN THE 00Z ECMWF/UKMET RUNS...BUT THE
GFS INDICATES THE PCPN WOULD BE HEAVY SN OVER THE W HALF OF UPR MI.
THE FARTHER E ECMWF MODEL GENERATES MUCH LIGHT PCPN OVER THE E.
CONSIDERING THE SGNFT DIFFERNCES THAT REMAIN...RELIED ON THE MODEL
CONSENSUS FOR THE FCST DETAILS. THIS CONSENSUS SUPPORTS HIER POPS
OVER THE E WITH A CHANGE IN PTYPE FM MIXED RA/SN TO MAINLY SN AS THE
INCREASING N BACKING NW WINDS ADVECT COLDER AIR INTO THE CWA.
IN THE WAKE OF THE DEEPENING LO MOVING INTO ONTARIO ON XMAS DAY...
THE PRES GRADIENT IS PROGGED TO TIGTHEN SGNFTLY AND H925 WINDS
INCREASE TO NEAR 45 KTS. NW WIND GUSTS MAY AT LEAST APRCH ADVY
CRITERIA...ESPECIALLY AT EXPOSED LOCATIONS NEAR LK SUP.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 652 AM EST SAT DEC 20 2014
LOW CLOUD FCST THE MAIN ISSUE THROUGH TONIGHT. CURRENTLY MVFR CIGS
REMAIN OVER KIWD AND ARE JUST TO WEST OF KCMX. EXPECT BKN-OVC CIGS
TO PERSIST AT BOTH TAFS TODAY AND TONIGHT. PRIMARY ISSUE WILL BE
WHETHER CIGS STAY BLO 020 OR JUST ABOVE AS THIS AFFECTS ALTERNATE
FLIGHT PLANNING. MEANWHILE...AT KSAW...STILL SOME FOG ISSUES VERY
EARLY ON AS LOW CLOUDS ARE JUST TO THE WEST AND MID CLOUDS HAVE
THINNED SOME IN THE LAST COUPLE HOURS. FOG IS SHALLOW THOUGH AND NOT
WIDESPREAD...SO DO NOT IT EXPECT IT TO LAST TOO LONG. THIS WILL BE
ESPECIALLY TRUE AFTER BKN-OVC MVFR STRATUS DECK SPREADS OVER CNTRL
UPR MICHIGAN THIS MORNING. WILL COVER THE FOG WITH TEMPO WHICH WORKED
WELL EARLIER TONIGHT AT KSAW. MVFR CLOUDS SHOULD PERSIST INTO TONIGHT
THOUGH LIKE THE WESTERN TAF SITES...MAIN QUESTION WILL REVOLVE
AROUND WHETHER PREVAILING CIGS END UP ABOVE OR BELOW 020.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 434 AM EST SAT DEC 20 2014
EXPECT S WINDS UNDER 20 KTS ASSOCIATED WITH HI PRES DRIFTING E THRU
SE CANADA TO PERSIST INTO SUN. THE S WINDS WILL INCREASE UP TO 25
KTS OVER AT LEAST THE E HALF OF THE LAKE ON SUN INTO MON AS A LO
PRES TRACKS E THRU THE NORTHERN PLAINS AND THE PRES GRADIENT
TIGHTENS OVER THE UPPER LAKES. AS ANOTHER LO PRES DEVELOPS TO THE S
ON TUE...THE FLOW WILL TEND TO BACK TOWARD THE NW. THE LATEST TRENDS
INDICATE THIS LO WILL DEEPEN SIGNFICANTLY AS IT MOVES TO THE NNE
THRU THE CENTRAL GREAT LAKES ON WED AND INTO SE ONTARIO ON XMAS DAY.
THE POTENTIAL FOR A N VEERING NW GALE EVENT FROM LATE ON WED THRU
XMAS DAY NOW LOOKS GREATER.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...KC
AVIATION...JLA
MARINE...KC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
616 AM CST SAT DEC 20 2014
.UPDATE...
ISSUED AT 616 AM CST SAT DEC 20 2014
MID LEVEL CLOUD COVER ACROSS WESTERN NORTH DAKOTA HAS LEAD TO THE
SEEDING OF THE LOW LEVEL STRATUS ACROSS THE FAR NORTHWEST. THE
RESULT IS LIGHT FLURRIES AND GREATLY IMPROVED VISIBILITIES FROM
THE PREVIOUS DENSE FOG. THUS...LET THE DENSE FOG ADVISORY EXPIRE
ON TIME FOR DIVIDE AND WILLIAMS COUNTIES. ELSEWHERE...GIVEN
OBSERVED TRENDS AND THE 11 UTC HRRR VISIBILITY FORECAST...EXTENDED
THE REMAINDER OF THE ADVISORY THROUGH 16 UTC AND ADDED LAMOURE AND
DICKEY COUNTIES. GIVEN THE TRENDS IN THE HRRR...PORTIONS OF THE
ADVISORY ACROSS THE JAMES RIVER VALLEY MAY NEED TO BE EXTENDED
INTO THE AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CST SAT DEC 20 2014
MAIN CONCERNS IN THE SHORT TERM ARE THE PERSISTENT FOG IN THE NORTH
AND CENTRAL TODAY...AND PRECIPITATION CHANCES AND WEATHER TYPE FOR
TODAY AND TONIGHT.
CURRENTLY...WATER VAPOR SATELLITE LOOP INDICATES THE NEXT UPPER
LEVEL SHORTWAVE TO AFFECT THE STATE TODAY WAS OVER NORTH CENTRAL
MONTANA/SOUTHERN SASKATCHEWAN/ALBERTA. AT THE SURFACE...LOW PRESSURE
WAS CENTERED OVER THE SOUTHERN BORDER OF ALBERTA/SASKATCHEWAN WITH A
TROUGH EXTENDING SOUTHEAST ACROSS EASTERN MONTANA. WIDESPREAD FOG
WITH VISIBILITIES RANGING FROM 1/4 MILE TO 1 MILE EXTENDED ACROSS
NORTHWESTERN AND MUCH OF CENTRAL NORTH DAKOTA.
TODAY THE UPPER LEVEL LOW/TROUGH IS PROGGED TO ENTER WESTERN NORTH
DAKOTA THIS MORNING AND ENTER CENTRAL NORTH DAKOTA THIS
AFTERNOON...EXITING NORTH DAKOTA SUNDAY MORNING. AT THE
SURFACE...THE SURFACE LOW AND ATTENDANT WARM FRONT IS FORECAST TO
MOVE EAST TODAY. THE LOW SHOULD MOVE EAST ACROSS SOUTHERN
SASKATCHEWAN/MANITOBA...WITH THE WARM FRONT ENTERING WESTERN NORTH
DAKOTA THIS MORNING...AND CENTRAL NORTH DAKOTA THIS AFTERNOON.
REGARDING THE FOG...AS THE AFOREMENTIONED SYSTEM MOVES INTO WESTERN
NORTH DAKOTA VISIBILITIES SHOULD IMPROVE WITH SUFFICIENT LOW TO MID
LEVEL MIXING. THE HRRR VISIBILITY PROGS SUPPORT THIS AS WELL. AREAS
OF FOG SHOULD PERSIST IN CENTRAL NORTH DAKOTA INTO THE
AFTERNOON...IMPROVING VISIBILITIES WITH TIME FROM WEST TO EAST AS THE
LOW PRESSURE SYSTEM ADVANCES EASTWARD.
THE SHORTWAVE AND SURFACE WARM FRONT WILL ALSO BRING LIGHT SCATTERED
PRECIPITATION TODAY AND TONIGHT. LOOKING AT INCREASING CHANCES THIS
MORNING IN THE WEST...EXPANDING INTO CENTRAL NORTH DAKOTA THIS
AFTERNOON. WARM ADVECTION ALOFT WILL RESULT IN MIXED PRECIPITATION
OF FREEZING DRIZZLE OR DRIZZLE EARLY THIS MORNING WITH CHANCES OF
LIGHT RAIN/DRIZZLE THIS AFTERNOON IN THE WEST AS TEMPERATURES RISE
INTO THE 30S. FARTHER EAST FREEZING DRIZZLE OR LIGHT SNOW SHOULD BE
THE PREDOMINANT WEATHER TYPE.
TONIGHT THE MAIN ENERGY FROM THE UPPER LEVEL TROUGH SHOULD KEEP THE
CHANCE OF PRECIPITATION CONFINED TO THE NORTH CENTRAL AND JAMES
RIVER VALLEY AND EASTWARD. FREEZING DRIZZLE OR LIGHT SNOW WOULD BE
THE MAIN WEATHER TYPE THERE TONIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 330 AM CST SAT DEC 20 2014
A WINTRY MIX POSSIBLE SUNDAY EVENING INTO MONDAY NIGHT...FOLLOWED
BY SNOWFALL POTENTIAL EARLY NEXT WEEK IMPACTING CHRISTMAS TRAVEL
HIGHLIGHT THE EXTENDED FORECAST.
FOR THE 00 UTC GUIDANCE SUITE...WHILE IN AGREEMENT ON GENERAL
FEATURES THROUGH THE EXTENDED FORECAST...SPATIAL DIFFERENCES IN
THE MASS FIELDS AND TIMING RESULT IN NON-TRIVIAL IMPACTS TO
SENSIBLE WEATHER THROUGH THE PERIOD. OVERALL...WEIGHED HEAVILY ON
THE 00 UTC ECMWF AND 03 UTC SREF WHICH RESIDE IN THE MIDDLE OF THE
ENVELOPE OF SOLUTIONS. FOR SUNDAY...A LEAD SHORTWAVE EJECTING OUT
OF THE ROCKIES IS FORECAST TO RESULT IN A RAIN AND SNOW MIX
DEPENDING ON SURFACE TEMPERATURES ACROSS WESTERN NORTH DAKOTA IN
THE AFTERNOON.
THE CHALLENGE IS SUNDAY EVENING INTO MONDAY NIGHT IN REGARDS TO
PRECIPITATION TYPE ACROSS CENTRAL NORTH DAKOTA. A MELTING LAYER
ALOFT ABOVE SUB-FREEZING SURFACE TEMPERATURES IS FORECAST TO
EXIST. HOWEVER...DRY AIR IN THE 900-750 MB LAYER WILL HAVE TO BE
SATURATED FOR PRECIPITATION TO REACH THE GROUND. THUS ENTERS THE
UNCERTAINTY AS TO HOW MUCH OF THE MELTING LAYER WILL REMAIN POST-
SATURATION DUE TO THE WET-BULB EFFECT. THERE APPEARS TO BE A BRIEF
WINDOW...ESPECIALLY ACROSS SOUTH CENTRAL NORTH DAKOTA...FOR THE
WARM LAYER TO BE AROUND +2 TO +2.5 C AROUND 00-03 UTC FOR A WINTRY
MIX OF FREEZING RAIN...SLEET AND MELTED SNOW TO BE POSSIBLE.
OVERALL AMOUNTS WILL BE LIGHT WITH THE COLUMN QUICKLY COOLING TO
SUPPORT ALL SNOW BETWEEN 03-06 UTC. THEREAFTER...ATTENTION TURNS
TO CYCLOGENESIS ACROSS THE EASTERN DAKOTAS AND INTO THE UPPER
MISSISSIPPI VALLEY MONDAY. THE 00 UTC DETERMINISTIC AND ENSEMBLE
SOLUTIONS SHOW A VARIED UPPER LEVEL LOW POSITION FROM NORTH
DAKOTA ON THE NAM TO IOWA ON THE GFS...WITH THE SREF AND ECMWF IN
BETWEEN. THUS...WIDESPREAD LIGHT SNOW IS EXPECTED FOR THE AREA
MONDAY ON ALL SOLUTIONS...WITH HIGHER AMOUNTS IN BANDING POSSIBLE.
HOWEVER...UNCERTAINTY IN THESE BANDS IS RATHER HIGH UNTIL THE MASS
FIELDS COME INTO BETTER AGREEMENT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 616 AM CST SAT DEC 20 2014
LIFR CEILINGS/VISIBILITIES CONTINUE AT KMOT AND KJMS. KBIS WAS
VARYING FROM IFR TO LIFR. FARTHER WEST KISN HAD JUST IMPROVED TO
VFR. KDIK SHOULD REMAIN VFR. STRATUS AND FOG SHOULD ERODE FROM
WEST TO EAST AS AN APPROACHING SYSTEM BRINGS A DRIER SOUTHWEST
FLOW. KMOT AND KBIS SHOULD BECOME VFR BEFORE/BY 18Z. KJMS NOT
IMPROVING UNTIL AROUND MID TO LATE AFTERNOON. THERE IS A RISK OF
ISOLATED TO SCATTERED MIXED PRECIPITATION AT KDIK/KISN THIS
MORNING...AND TO ALL TAF SITES THIS AFTERNOON. DID NOT MENTION IN
TAFS AS LESS THAN 50 PERCENT CHANCE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR NDZ002>005-
010>013-019>023-025-035>037-048-051.
&&
$$
UPDATE...AYD
SHORT TERM...JV
LONG TERM...AYD
AVIATION...JV
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
559 AM CST SAT DEC 20 2014
.AVIATION... /12Z TAF CYCLE/
LOW END MVFR CIGS ONGOING THIS MORNING FOR KSAT/KAUS/KSSF WITH
KDRT BOUNCING BETWEEN LOW MVFR AND VFR AS BKN010 TO SCT010 KEEP
BEING OBSERVED. WILL GO ON PESSIMISTIC SIDE FOR KDRT THROUGH
17-20Z BEFORE EVENTUAL BREAK OUT TO VFR OCCURS THIS AFTERNOON. FOR
CENTRAL SITES HOWEVER, FEEL MVFR WILL RULE THROUGH THE AFTERNOON
PER RAP/NAM SOUNDINGS AND HRRR OUTPUT. TOP OF STRATUS CLOUD DECK
LOOKS TO BE AROUND 3.5-4 KFT, RESULTING IN A 1-1.5 KFT THICK
STRATUS CLOUD LAYER. OVERNIGHT, IFR IS LIKELY FOR ALL SITES WITH
ANOTHER SLOW IMPROVEMENT TO MVFR/VFR ON SUNDAY AFTN.
SURFACE WINDS WILL BE N/NNE AT 10 KTS THROUGH THE DAY AND THEN
BECOME LIGHT AND VARIABLE OVERNIGHT TONIGHT. /ALLEN/
&&
.PREV DISCUSSION... /ISSUED 357 AM CST SAT DEC 20 2014/
SHORT TERM (TODAY THROUGH SUNDAY)...
AN UPPER LEVEL TROUGH SLOWLY DEVELOPS OVER THE PLAINS STATES. A
SERIES OF WEAK UPPER LEVEL SHORT-WAVES TRAVERSE THE TROUGH TO
GENERATE WEAK ISENTROPIC LIFT. MOISTURE DEPTH ONLY SUFFICIENT FOR
MAINTENANCE OF STRATUS/STRATOCUMULUS DECK WITH NO RAIN EXPECTED.
BELOW AVERAGE DAYTIME AND ABOVE AVERAGE NIGHTTIME TEMPERATURES ARE
EXPECTED DUE TO THE CLOUD COVER. PATCHY FOG WILL PERSIST ACROSS
HIGHER ELEVATIONS OF THE HILL COUNTRY THROUGH AROUND 9 AM THIS
MORNING.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
THE UPPER LEVEL TROUGH SHIFTS EAST BY TUESDAY. SOUTHWESTERLY LOWER
LEVEL FLOW DEVELOPS ALLOWING SKIES TO MOSTLY CLEAR WITH WELL ABOVE
AVERAGE TEMPERATURES MONDAY. A MID LEVEL SHORT-WAVE MOVING THROUGH
THE TROUGH FORCES A COLD FRONT TO MOVE ACROSS SOUTH CENTRAL TEXAS
TUESDAY MORNING. THERE IS SUFFICIENT MOISTURE FOR ISOLATED SHOWERS
ALONG THE FRONT ACROSS FAR EASTERN AREAS AND HAVE INTRODUCED
MENTION. ZONAL FLOW ALOFT FOR MID TO LATE WEEK WITH AN UPPER LEVEL
TROUGH MOVING ACROSS THE PLAINS FORCING ANOTHER COLD FRONT ACROSS
SOUTH CENTRAL TEXAS FRIDAY. NO RAIN IS EXPECTED AS MOISTURE DEPTH
WILL BE MINIMAL. COOLER TEMPERATURES TUESDAY INTO WEDNESDAY...THEN
WARMER THURSDAY CHRISTMAS DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 56 44 60 48 70 / - - - - -
AUSTIN BERGSTROM INTL AIRPORT 56 42 59 46 70 / - - - - -
NEW BRAUNFELS MUNI AIRPORT 56 45 61 48 71 / - - - - -
BURNET MUNI AIRPORT 54 40 58 46 69 / - - - - -
DEL RIO INTL AIRPORT 60 45 62 46 73 / - - - - -
GEORGETOWN MUNI AIRPORT 54 40 58 47 69 / - - - - -
HONDO MUNI AIRPORT 59 45 62 46 72 / - - - - -
SAN MARCOS MUNI AIRPORT 57 43 61 46 70 / - - - - -
LA GRANGE - FAYETTE REGIONAL 57 45 61 48 71 / - - - - -
SAN ANTONIO INTL AIRPORT 57 45 61 49 72 / - - - - -
STINSON MUNI AIRPORT 58 46 62 49 72 / - - - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...15
SYNOPTIC/GRIDS...04
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
244 PM EST SAT DEC 20 2014
.SYNOPSIS...
A FRONTAL ZONE WILL REMAIN NEAR THE SOUTHEAST COAST
THROUGH TUESDAY. A SERIES OF LOW PRESSURE SYSTEMS WILL MOVE
NORTHEASTWARD ALONG THE FRONT. A STRONG COLD FRONT APPROACHING
FROM THE WEST WILL MOVE THROUGH THE FORECAST AREA WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
RAIN HAS ALMOST CLEARED THE FORECAST AREA WITH SOME LINGERING RAIN
OVER THE EASTERN MIDLANDS BUT THIS TOO SHOULD SHIFT OUT BY 2 PM.
TEMPERATURES HAVE NOT MOVED MUCH TODAY DUE TO EXTENSIVE CLOUDS AND
LIGHT RAIN BUT MAY RISE A DEGREE OR TWO BEFORE SUNSET NOW THAT THE
RAIN HAS CLEARED. LOW CLOUDS EXTEND WELL BACK INTO ALABAMA AND
WITH MODEL TIME HEIGHTS AND CROSS SECTIONS SHOWING SIGNIFICANT
MOISTURE IN THE LOWER LEVELS DO NOT THINK THE LOW CLOUDS WILL
BREAK OVERNIGHT. WITH THE FORECAST AREA IN THE WAKE OF THE
DEPARTING SHORTWAVE TROUGH AND THEREFORE LACK OF UPWARD VERTICAL
MOTION DO NOT THINK THERE WILL BE SIGNIFICANT DRIZZLE OVERNIGHT
BUT DO THINK THERE WILL BE AREAS OF FOG THAT DEVELOPS AND POSSIBLY
SOME DENSE FOG IN TYPICAL LOW LYING AREAS. OVERNIGHT LOWS TONIGHT
SHOULD FALL INTO THE MID 30S ACROSS THE FORECAST AREA.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
THE MID/UPPER FLOW WILL BECOME INCREASINGLY SOUTHWEST DURING THE
DAY ON SUNDAY INTO SUNDAY NIGHT AS A S/W TROUGH MOVES INTO THE MS
VALLEY. MODEL TIME SECTIONS SHOW INCREASING LOW LEVEL MOISTURE AND
ISENTROPIC LIFT THROUGH THE PERIOD AS WEAK LOW PRESSURE DEVELOPS
IN THE GULF AND MOVES NORTHEAST ACROSS FLORIDA AND OFF THE
SOUTHEAST COAST. DURING THE PERIOD...PRECIPIATION AMOUNTS LOOK TO
BE LESS THAN ONE QUARTER INCH AS THE LIGHT RAIN/DRIZZLE IS
EXPECTED. WILL CONTINUE WITH SOME PATCHY FOG SUNDAY MORNING WITH
POPS AROUND 10 PERCENT OR LESS. HOWEVER...THROUGH THE AFTERNOON
WITH INCREASING ISENTROPIC LIFT FROM S TO N EXPECT A GRADUAL
INCREASE IN POPS. POPS GO FROM SLIGHT CHANCE SUNDAY TO CATEGORICAL
BY LATER SUNDAY NIGHT. AS FOR TEMPERATURES...EXPECT LITTLE DIURNAL
RANGE GIVEN CLOUD COVER AND PRECIPITATION POTENTIAL. HAVE TRENDED
TOWARD JUST BELOW CONSENSUS FOR HIGHS AND JUST ABOVE FOR LOWS.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
A MORE VIGOROUS S/W WILL DIG A DEEP TROUGH ACROSS THE EASTERN HALF
OF THE COUNTRY BY MID WEEK AS MID LEVEL LOW CLOSES OFF ACROSS THE
UPPER PLAINS/UPPER MIDWEST. MOISTURE ACROSS THE REGION WILL REMAIN
RATHER HIGH THROUGH MIDWEEK WITH PW VALUES INCREASING TO OVER 1.5
INCHES BY LATE TUESDAY NIGHT/INTO WEDNESDAY. AHEAD OF THIS SYSTEM
A WEDGE WILL DEVELOP ACROSS THE AREA ON MONDAY AND MODELS INDICATE
THIS FEATURE HOLDING INTO TUESDAY. HAVE TRENDED WITH LOWER
TEMPERATURES THROUGH THE PERIOD AS ECMWF/GFS/NAM INDICATE NE LOW
LEVEL FLOW AND VERY STABLE AIRMASS IN PLACES OVER THE REGION.
HOWEVER...BY LATE TUESDAY AFTERNOON/TUESDAY NIGHT BOTH ECMWF AND
GFS LIFT THE WARM FRONT NORTHWARD ACROSS THE AREA. TEMPERATURES
WILL LIKELY RISE SLOWLY TUESDAY NIGHT AS LOW LEVEL FLOW SHIFTS
FROM NE AND E TO A MORE SOUTHERLY DIRECTION. THE GFS AND ECMWF
MODELS HAVE CONTINUED WITH THE TREND OF THE SLOWER COLD FRONTAL
PASSAGE ON WEDNESDAY. THE AREA WILL REMAIN UNDER ISENTROPIC LIFT
THROUGH MUCH OF THE PERIOD FROM MONDAY INTO EARLY WEDNESDAY WITH
AN INCREASING WIND FIELD TUESDAY NIGHT INTO WEDNESDAY. THE GFS
SHOWS A 50 TO 60 KT H8 JET ASSOCIATED WITH THE SYSTEM EARLY
WEDNESDAY. WITH THE DELAY OF THE FRONTAL PASSAGE AND AREA BECOMING
INCREASINGLY UNSTABLE BY WEDNESDAY HAVE CONTINUED THE MENTION OF
THUNDERSTORMS IN THE FORECAST. ALSO EXPECT INCREASING SURFACE
WINDS WITH TIGHT PRESSURE GRADIENT AND STRONG LOW LEVEL WINDS ON
WEDNESDAY.
THE INCREASING SHEAR AND POTENTIAL FOR SUFFICIENT INSTABILITY
INDICATES A POSSIBILITY OF STRONG/SEVERE THUNDERSTORMS.
EXPECT A DIMINISHED SHOWER CHANCE WEDNESDAY NIGHT BEHIND THE
FRONT WITH BREEZY CONDITIONS. THE MODELS HAVE BEEN CONSISTENT
SHOWING A DRY WEST FLOW BETWEEN HIGH PRESSURE NEAR THE GULF COAST
AND LOW PRESSURE LIFTING NORTH OF THE GREAT LAKE REGION FOR
CHRISTMAS DAY. BREEZY CONDITIONS MAY CONTINUE DURING THE DAY...BUT
THE MODEL TREND HAS BEEN TO SHOW THE RIDGE FARTHER NORTHWARD WITH
LESS OF A PRESSURE GRADIENT IN THE FORECAST AREA.
MOISTURE MAY INCREASE AHEAD OF ANOTHER COLD FRONT APPROACHING
FRIDAY NIGHT INTO SATURDAY. HAVE CONTINUED THE MENTION OF A SMALL
POP FRIDAY NIGHT AND SATURDAY. EXPECT TEMPERATURES TO BE COOLER
THAN NORMAL MONDAY AND TUESDAY...ABOVE NORMAL WEDNESDAY AND THEN
RETURNING TO MORE NORMAL TEMPERATURES FOR THE REMAINDER OF THE
PERIOD.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
MVFR/IFR CIG RESTRICTIONS EXPECTED THROUGH MUCH OF THE 24 HOUR
FORECAST PERIOD.
REGIONAL RADAR SHOWING THE RAIN ASSOCIATED WITH THE PASSING
SHORTWAVE TROUGH HAS SHIFTED EAST OF THE TERMINALS AND DO NOT
EXPECT ANY ADDITIONAL RAIN. SUBSIDENCE BEHIND THE SHORTWAVE HAS
STRENGTHENED THE INVERSION AND LOW LEVEL MOISTURE TRAPPED BELOW IT
SO AM EXPECTING THE MVFR/IFR CIGS TO CONTINUE THROUGH THE FORECAST
PERIOD. HRRR GUIDANCE HAS BEEN TO OPTIMISTIC WITH CIGS THUS FAR
TODAY AND MET GUIDANCE HAS BEEN DOING WELL WITH THE LOW CIGS SO
HAVE LEANED TOWARD THAT GUIDANCE AND THE LAV GUIDANCE LOWERING
CIGS TO IFR ALL TERMINALS AFTER 04Z WITH POSSIBLE LIFR CIGS
OGB/AGS/DNL. VSBYS ALSO LIKELY TO DROP INTO MVFR AND POSSIBLY IFR
04Z-12Z TIME FRAME. SOME IMPROVEMENT IS EXPECTED AFTER 13Z BUT LOW
CONFIDENCE THAT VFR CONDITIONS WILL RETURN.
EXTENDED AVIATION OUTLOOK...WIDESPREAD LOW CLOUDS AND
PRECIPITATION EXPECTED LATE SUNDAY NIGHT INTO MONDAY WITH ANOTHER
GULF COAST SYSTEM CROSSING THE REGION. YET ANOTHER SYSTEM WILL
AFFECT THE AREA TUESDAY NIGHT BRINGING POSSIBLE RESTRICTIONS WITH
WINDY CONDITIONS EXPECTED WEDNESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
77
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
137 PM EST SAT DEC 20 2014
.SYNOPSIS...
A FRONTAL ZONE WILL REMAIN NEAR THE SOUTHEAST COAST
THROUGH TUESDAY. A SERIES OF LOW PRESSURE SYSTEMS WILL MOVE
NORTHEASTWARD ALONG THE FRONT. A STRONG COLD FRONT APPROACHING
FROM THE WEST WILL MOVE THROUGH THE FORECAST AREA WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
RAIN HAS ALMOST CLEARED THE FORECAST AREA WITH SOME LINGERING RAIN
OVER THE EASTERN MIDLANDS BUT THIS TOO SHOULD SHIFT OUT BY 2 PM.
TEMPERATURES HAVE NOT MOVED MUCH TODAY DUE TO EXTENSIVE CLOUDS AND
LIGHT RAIN BUT MAY RISE A DEGREE OR TWO BEFORE SUNSET NOW THAT THE
RAIN HAS CLEARED. LOW CLOUDS EXTEND WELL BACK INTO ALABAMA AND
WITH MODEL TIME HEIGHTS AND CROSS SECTIONS SHOWING SIGNIFICANT
MOISTURE IN THE LOWER LEVELS DO NOT THINK THE LOW CLOUDS WILL
BREAK OVERNIGHT. WITH THE FORECAST AREA IN THE WAKE OF THE
DEPARTING SHORTWAVE TROUGH AND THEREFORE LACK OF UPWARD VERTICAL
MOTION DO NOT THINK THERE WILL BE SIGNIFICANT DRIZZLE OVERNIGHT
BUT DO THINK THERE WILL BE AREAS OF FOG THAT DEVELOPS AND POSSIBLY
SOME DENSE FOG IN TYPICAL LOW LYING AREAS. OVERNIGHT LOWS TONIGHT
SHOULD FALL INTO THE MID 30S ACROSS THE FORECAST AREA.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
HIGH LOW-LEVEL MOISTURE WILL CONTINUE THROUGH TONIGHT. THERE MAY
BE AREAS OF FOG AS INDICATED BY THE GFS MOS. LITTLE TEMPERATURE
RECOVERY SHOULD OCCUR TODAY BECAUSE OF CLOUDINESS. THE HIGH
TEMPERATURE GUIDANCE IS LIKELY TOO WARM. LEANED TOWARD THE MORE
CONSISTENT GFS MOS FOR THE TEMPERATURE TONIGHT.
WEAK ISENTROPIC LIFT SUPPORTS A RAIN CHANCE SUNDAY MAINLY LATE AS
MOISTURE BECOMES DEEPER AHEAD OF ANOTHER MID-LEVEL SHORTWAVE
TROUGH. THE GUIDANCE CONSENSUS SUPPORTS POPS OF 20 TO 30 PERCENT
FOR MAINLY LATE IN THE DAY. THE MODELS ARE CONSISTENT DISPLAYING
SIGNIFICANT MOISTURE AND ISENTROPIC LIFT SUNDAY NIGHT INTO MONDAY
ESPECIALLY IN THE SOUTHEAST PART OF THE FORECAST AREA. THE MODELS
INDICATE MOISTURE BECOMING SHALLOW LATE MONDAY BEHIND THE
ASSOCIATED MID-LEVEL SHORTWAVE TROUGH. USED THE GUIDANCE CONSENSUS
FOR THE POP FORECAST. THE GUIDANCE HIGH TEMPERATURES ARE LIKELY
TOO WARM BECAUSE OF CLOUDINESS AND A LOW-LEVEL NORTHEAST FLOW. THE
GUIDANCE LOW TEMPERATURE WERE CLOSE. THE MODELS HAVE BEEN
CONSISTENT INDICATING ALL-LIQUID PRECIPITATION.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
HIGH MOISTURE SHOULD CONTINUE MONDAY NIGHT THROUGH TUESDAY AHEAD
OF A WARM FRONT AND DEEPENING UPPER-LEVEL TROUGH. THE GFS AND
ECMWF MODELS HAVE TRENDED SLOWER WITH THE PASSAGE OF A STRONG
COLD FRONT AND NOW DISPLAY FRONTAL PASSAGE WEDNESDAY. THE WARM
FRONT MAY LIFT NORTHWARD AHEAD OF THE COLD FRONT.
IF THE FORECAST AREA GETS INTO THE WARM SECTOR THERE MAY BE
ENOUGH INSTABILITY FOR THUNDERSTORMS AHEAD OF THE COLD FRONT TUESDAY
NIGHT OR WEDNESDAY. THE GFS AND ECMWF DISPLAY H85 WINDS OF 40 TO
60 KNOTS. THE SHEAR AND POTENTIAL FOR SUFFICIENT INSTABILITY
INDICATES A POSSIBILITY OF SEVERE THUNDERSTORMS.
EXPECT A DIMINISHED SHOWER CHANCE WEDNESDAY NIGHT BEHIND THE
FRONT WITH BREEZY CONDITIONS. THE MODELS HAVE BEEN CONSISTENT
SHOWING A DRY WEST FLOW BETWEEN HIGH PRESSURE NEAR THE GULF COAST
AND LOW PRESSURE LIFTING NORTH OF THE GREAT LAKE REGION FOR
CHRISTMAS DAY. BREEZY CONDITIONS MAY CONTINUE DURING THE DAY...BUT
THE MODEL TREND HAS BEEN TO SHOW THE RIDGE FARTHER NORTHWARD WITH
LESS OF A PRESSURE GRADIENT IN THE FORECAST AREA.
MOISTURE MAY INCREASE AHEAD OF ANOTHER COLD FRONT APPROACHING
FRIDAY. THE GFS SHOWS LESS MOISTURE COMPARED TO THE ECMWF. THE
ECMWF KEEPS MUCH OF THE FORCING ASSOCIATED WITH THE FRONT WEST OF
THE FORECAST AREA THROUGH FRIDAY. THE GFS...ECMWF...AND EKD MOS
POPS ARE JUST 10 TO 20 PERCENT.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
MVFR/IFR CIG RESTRICTIONS EXPECTED THROUGH MUCH OF THE 24 HOUR
FORECAST PERIOD.
REGIONAL RADAR SHOWING THE RAIN ASSOCIATED WITH THE PASSING
SHORTWAVE TROUGH HAS SHIFTED EAST OF THE TERMINALS AND DO NOT
EXPECT ANY ADDITIONAL RAIN. SUBSIDENCE BEHIND THE SHORTWAVE HAS
STRENGTHENED THE INVERSION AND LOW LEVEL MOISTURE TRAPPED BELOW IT
SO AM EXPECTING THE MVFR/IFR CIGS TO CONTINUE THROUGH THE FORECAST
PERIOD. HRRR GUIDANCE HAS BEEN TO OPTIMISTIC WITH CIGS THUS FAR
TODAY AND MET GUIDANCE HAS BEEN DOING WELL WITH THE LOW CIGS SO
HAVE LEANED TOWARD THAT GUIDANCE AND THE LAV GUIDANCE LOWERING
CIGS TO IFR ALL TERMINALS AFTER 04Z WITH POSSIBLE LIFR CIGS
OGB/AGS/DNL. VSBYS ALSO LIKELY TO DROP INTO MVFR AND POSSIBLY IFR
04Z-12Z TIME FRAME. SOME IMPROVEMENT IS EXPECTED AFTER 13Z BUT LOW
CONFIDENCE THAT VFR CONDITIONS WILL RETURN.
EXTENDED AVIATION OUTLOOK...WIDESPREAD LOW CLOUDS AND
PRECIPITATION EXPECTED LATE SUNDAY NIGHT INTO MONDAY WITH ANOTHER
GULF COAST SYSTEM CROSSING THE REGION. YET ANOTHER SYSTEM WILL
AFFECT THE AREA TUESDAY NIGHT BRINGING POSSIBLE RESTRICTIONS WITH
WINDY CONDITIONS EXPECTED WEDNESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
NEAR TERM...HC
AVIATION...HC
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
401 PM CST SAT DEC 20 2014
.SHORT TERM...
247 PM CST
THROUGH SUNDAY NIGHT...
THE STREAK OF CLOUDY DAYS CONTINUES...WITH THE STUBBORN PATTERN TO
CONTINUE. AS A RESULT OF THE THICK CLOUD COVER...AND LACK OF
ORGANIZED ADVECTION OF ANY WARMER AIR AT THE SFC...TEMPS HAVE HELD
MAINLY ARND 30 TO 35 ACROSS THE BULK OF THE CWFA. SFC RIDGE
CONTINUES TO DRIFT EAST THIS AFTN...WITH A WEAK SOUTHERLY FLOW
DEVELOPING. THERE WAS A WEAK MID-LVL VORT LIFTING NORTHEAST ACROSS
SOUTHERN WISC/WESTERN LOWER MI...WHICH WAS ABLE TO PRODUCE A FEW
FLURRIES ACROSS THE FAR NORTHERN IL AREAS.
THIS AFTN/EARLY EVE LOOKS TO REMAIN QUIET/DRY...WITH A LIGHT
SOUTH/SOUTHEAST WIND. IR IMAGERY SHOWS THE NEXT WAVE ACROSS THE
CENTRAL PLAINS...WHICH IS PROGGED TO ARRIVE ACROSS NORTHWEST IL
AFTER MIDNIGHT. THERE APPEARS TO BE SOME WEAK ADVECTION OF MOISTURE
IN THE LOW-LEVELS OVERNIGHT. SOUNDINGS SUGGEST A NARROW WARM WEDGE
ALOFT WHICH COULD TRANSITION ANY PRECIP OVERNIGHT TO LIQUID. THE
FORCING/OMEGA IS RATHER WEAK...WHICH MAY LIMIT DROPLET SIZE AND
RESULT IN JUST PATCHY FREEZING DRIZZLE. TEMPS WILL LIKELY NOT MOVE
MUCH OVERNIGHT...SO HAVE HELD ONTO MID/UPR 20S OVERNIGHT.
LOCAL ARW8KM SOLUTION INDICATES THE MOISTURE TO BE RATHER MARGINAL
WITH THE SYSTEM ARRIVING OVERNIGHT/SUN MORNING...BUT PROGRESSIVE AND
LIFTING NORTH OF THE CWFA BY MIDDAY. WEAK THERMAL RIDGE AT 850MB
WOULD SUGGEST TEMPS MAY ACTUALLY WARM SUN AFTN...HOWEVER GIVEN THE
STUBBORN PATTERN WE HAVE BEEN IN WOULD LEAN TOWARDS NUDGING TEMPS
DOWN A DEGREE OR TWO. MOISTURE LAYER WILL REMAIN LOCKED IN ACROSS
THE REGION THRU SUN/SUN NGT. WITH A CONTINUED SOUTHERLY FLOW AT THE
SFC...TEMPS WILL LIKELY ONLY FALL TO ARND 30/LOW 30S.
BEACHLER
&&
.LONG TERM...
247 PM CST
MONDAY THROUGH SATURDAY...
500MB TROUGH BEGINS TO DIG INTO THE CENTRAL CONUS MON MORNING...WITH
WARM AIR STEADILY ADVECTING NORTH ACROSS THE FORECAST AREA. WHILE
THE THICK CLOUD COVER WILL PERSIST...THE PUSH OF WARM/MOIST AIR WILL
BRING TEMPS INTO THE 40S THE FAR SOUTHERN CWFA COULD SEE A FEW
LOCATIONS TOUCH THE UPR 40S MON AFTN. PRECIP WILL STEADILY PUSH EAST
AS THE UPPER LEVEL SYSTEM PROGRESSES TOWARDS THE REGION...BUT WITH
THE WARM AIR IN PLACE PRECIP SHUD FALL AS RAIN.
MON NGT THE 500MB VORT WILL SLIDE INTO THE UPPER MIDWEST...BUT THE
TROUGH WILL DIG SOUTH ACROSS THE SOUTHERN PLAINS. GUIDANCE HAS BEEN
INDICATING A SECONDARY SHORTWAVE EJECTING FROM THE TROUGH AXIS...AND
LIFTING IT NORTHEAST ACROSS THE TENN VALLEY CHRISTMAS EVE. THE
NORTHERN SFC LOW WILL BE WRAPPED UP ACROSS CENTRAL WISC TUE...WITH
THE MOIST CHANNEL FEEDING NORTH ACROSS THE FORECAST AREA THRU TUE
AFTN. THE SOUTHERN LOW WILL BE QUICKLY DEEPENING AS IT LIFTS NORTH
ACROSS THE OHIO VALLEY WED MORNING...ALLOWING WINDS TO BE ON THE
INCREASE AND HELPING TO STEADILY TRANSITION PRECIP OVER FROM RAIN TO
SNOW POST FROPA WED MORNING.
THE LAST SEVERAL CYCLES OF GUIDANCE HAVE DEMONSTRATED DIFFERENCES IN
PLACEMENT/TRACK OF THE SFC LOW WED AFTN/EVE. LATEST SOLUTION IS
PROGGED TO LIFT NORTH ACROSS NORTHERN IN AND THEN SLIGHTLY
RETROGRADE ACROSS THE SOUTHERN TIP OF LAKE MICHIGAN WED EVE. THEN BY
CHRISTMAS DAY THE TROUGH WILL BE PIVOTING EAST AND HELPING TO LIFT
THE SFC LOW NORTHEAST AWAY FROM THE REGION. SOME WRAP AROUND
MOISTURE/SNOW LOOKS FAVORABLE WED NGT/THUR MORNING...BEFORE COMING
TO AN END JUST AFTER DAYBREAK CHRISTMAS MORNING. THIS SYSTEM WILL
CONTINUE TO BE CLOSELY MONITORED.
TEMPS WILL BE RETURNING TO MORE SEASONAL CONDS...WITH HIGHS
CHRISTMAS DAY IN THE LOW/MID 30S. FLOW REMAINS RATHER PROGRESSIVE
WITH ANOTHER WEAK PUSH OF WARMER AIR RETURNING FRI AND TEMPS BACK TO
THE UPR 30S/LOW 40S. THEN FOR FRI ENSEMBLES ARE INDICATING YET
ANOTHER TROUGH BEGINNING TO DIG INTO THE CENTRAL CONUS...WITH A SFC
LOW LIFTING NORTHEAST ACROSS THE WESTERN GREAT LAKES.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* MVFR CIGS RETURNING THIS EVENING OR OVERNIGHT.
* PATCHY FREEZING DRIZZLE EARLY SUNDAY.
BMD/IZZI
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE REMAINS OVER THE REGION TODAY RESULTING IN LIGHT
FLOW...HOWEVER WINDS WILL TREND MORE SOUTHERLY THOUGH THE TAF PERIOD
AS THE HIGH DRIFTS EAST OF THE AREA. MVFR CIGS HAVE SCATTERED AND
DRIFTED EAST OF THE TERMINALS THIS MORNING...BUT EXPECT A RETURN OF
THE MVFR THIS EVENING OR OVERNIGHT...THOUGH SPECIFIC TIMING REMAINS
UNCERTAIN. OVERNIGHT...WARM AIR ADVECTION INCREASES JUST OFF THE
DECK AND MAY ALLOW FOR SOME LIGHT FREEZING DRIZZLE TO DEVELOP WITH
SURFACE TEMPS JUST BELOW FREEZING. FORCING IS BEST OVER NORTH
CENTRAL ILLINOIS SO WILL MAINTAIN PROB30 MENTION AT RFD ONLY FOR
NOW. WINDS WILL GRADUALLY INCREASE THROUGH THE DAY SUNDAY AS THE
GRADIENT TIGHTENS AHEAD OF LOW PRESSURE APPROACHING FROM THE
NORTHWEST.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM CONFIDENCE IN CIG TRENDS BUT LOW IN TIMING.
* LOW CONFIDENCE IN FREEZING DRIZZLE.
BMD/IZZI
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...DRY...MAINLY VFR.
MONDAY...RAIN AND MVFR LIKELY. BREEZY SOUTH-SOUTHEAST WINDS.
TUESDAY...CHANCE OF RAIN. MVFR POSSIBLE. SOUTH WINDS BECOMING WEST.
WEDNESDAY...CHANCE OF SNOW. MVFR/IFR POSSIBLE. NORTHWEST WINDS
BECOMING GUSTY FROM THE WEST.
THURSDAY...DRY. MAINLY VFR. GUSTY WEST WINDS DIMINISHING.
FRIDAY...CHANCE OF RAIN OR SNOW. MVFR POSSIBLE. LIGHT EAST WINDS
BECOMING WEST.
RATZER
&&
.MARINE...
203 PM CST
LIGHT SOUTHEAST TO EAST WINDS WILL INCREASE TO 10-25 KT TOMORROW
MORNING THEN TO 30 KT IN THE AFTERNOON AS THE GRADIENT TIGHTENS
BETWEEN THE DEPARTING HIGH AND THE NEXT LOW. THE LOW MOVES OVER THE
DAKOTAS SUNDAY NIGHT AND MODELS AGREE A BIT MORE IN THE PATTERN
EARLY NEXT WEEK. HAVE MEDIUM CONFIDENCE IN THE WIND FORECAST WITH
THIS NEXT LOW. THE LOW WEAKENS AS IT MOVES OVER WISCONSIN TUESDAY
AND A SECOND LOW FORMS OVER THE SOUTHERN MISSISSIPPI VALLEY TUESDAY
AFTERNOON. THE SECOND LOW WILL RACE NORTH AND DEEPEN REACHING
MICHIGAN WEDNESDAY. MODELS DIFFER ON HOW QUICKLY THE LOW WILL REACH
MICHIGAN. BOTH MODELS CONTINUE TO FEATURE WESTERLY HIGH END GALES
BEHIND THE LOW WEDNESDAY AFTERNOON INTO THURSDAY. WEST WINDS
DIMINISH THURSDAY AS THE LOW CONTINUES OFF TO THE NORTH. THE NEXT
LOW MOVES OVER THE SOUTHERN PLAINS THURSDAY AFTERNOON. GUIDANCE
DIFFERS ON THIS LOWS PATH BUT IT SHOULD IMPACT THE LAKE LATE NEXT
WEEK.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740...10 PM SUNDAY TO 3 AM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
300 PM CST Sat Dec 20 2014
.SHORT TERM...(Tonight)
ISSUED AT 259 PM CST SAT DEC 20 2014
Cloudy skies persist across much of central Illinois this afternoon:
however, 20z/2pm visible satellite imagery shows a large tear in the
overcast developing from near Decatur southeastward to Flora.
Although the HRRR has been a bit overdone with the clearing, it
continues to suggest at least thinning clouds across the E/SE KILX
CWA late this afternoon into the evening. In fact, with 925mb winds
remaining light/variable and not really picking up a strong S/SW
component until Sunday, portions of the SE may see partly cloudy
conditions persist through the night. Further north and west, low
clouds will be on the increase from the west. Forecast soundings
and model RH profiles indicate that the lowest clouds/fog will
remain just W/NW of central Illinois tonight. Due to cloud cover
and a light S/SE wind, low temperatures will be a couple of degrees
warmer than last night. Coolest readings in the middle 20s will
occur south of I-70 where skies will likely remain partly cloudy,
while lows stay in the upper 20s/lower 30s elsewhere.
&&
.LONG TERM...(Sunday through Saturday)
ISSUED AT 259 PM CST SAT DEC 20 2014
Still looking like only one major system to impact central and
southeast Illinois through the coming week. Unfortunately, the
potential exists for the biggest travel headaches with this system
to arrive later Tuesday night into Christmas Eve. However, it should
be noted that no model consensus exists with respect to this
system`s snow potential locally. In fact, at this point, more model
solutions keep the snowfall minimal than not. Nevertheless, it would
be prudent to keep an eye on the forecast heading into the Christmas
holiday as the ultimate outcome becomes more clear.
High pressure at the surface and mostly neutral upper flow aloft
will keep its grip on the local weather for one more day on Sunday.
Southerly return flow on the back side of the surface ridge will
push temperatures a few degrees warmer than today. Meanwhile, a
vigorous upper wave, currently crashing ashore along the Pacific
Northwest coast, will begin to dig a significant trof over the
Plains, also inducing surface cyclogenesis.
Strong WAA/isentropic ascent ahead of this slow moving system will
begin to spread rain into the area on Monday. The rain chances will
continue into Monday night and Tuesday. This initial part of the
forecast is fairly well agreed upon by the models.
The initial surface low beneath the mean Plains upper trof will not
move much across the northern Plains into the upper Midwest between
Monday and Tuesday. Attention then turns to another vigorous wave
that will round the base of the mean trof Tuesday into Wednesday.
This wave should induce a second surface low, one that will become
dominant, as it lifts northeast into Canada by the end of the week.
The model agreement with the timing/track/strength of this secondary
low by Tuesday night into Wednesday is not very good. The track of
this low is critical to how quickly our precipitation will change
over to snow Tuesday night into Wednesday, and if we will be
impacted by the heavier snowfall within this system`s deformation
zone. While the threat is certainly there, at this point only the
GFS has been impacting the forecast area very significantly.
Behind the midweek system, another wave will arrive by Friday.
However, the models have been trending weaker with this system
overall, as well as drier. So, have backed away from rain and/or
snow chances as this system arrives.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 1140 AM CST SAT DEC 20 2014
MVFR ceilings will gradually spread across central Illinois this
afternoon/evening. 17z/11am obs show MVFR conditions
along/southwest of a KGBG to KSPI line, with VFR ceilings further
east across the remainder of the area. As light S/SE flow
gradually becomes more S/SW, these lower clouds will return to all
terminals by evening. Based on the latest HRRR output, have
introduced MVFR at KPIA by 21z, then further east to KCMI by 03z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Bak
AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1153 AM CST SAT DEC 20 2014
.SHORT TERM...
302 AM CST
TODAY THROUGH SUNDAY...
THE MAIN CONCERNS DURING THE SHORT TERM WILL BE WILL BE CENTERED
AROUND THE POTENTIAL FOR SOME FREEZING DRIZZLE ACROSS PORTIONS OF
NORTHERN ILLINOIS LATE TONIGHT INTO EARLY SUNDAY MORNING.
SURFACE HIGH PRESSURE CONTINUES TO BE IN PLACE ACROSS THE GREAT
LAKES REGION EARLY THIS MORNING. HOWEVER...ATTENTION FOR TODAY IS
FOCUSED ON A MID LEVEL DISTURBANCE...CURRENTLY NOTED IN THE WATER
VAPOR IMAGERY ACROSS SOUTHWESTERN IOWA. THIS DISTURBANCE WILL SHIFT
EASTWARD ACROSS CENTRAL AND NORTHERN ILLINOIS THROUGH EARLY THIS
AFTERNOON. OVERALL...MODEL SOUNDINGS DO NOT APPEAR ALL THAT
FAVORABLE FOR ANY LIGHT SNOW. HOWEVER...THERE HAVE BEEN SOME REPORTS
OF LIGHT FLURRIES ACROSS IOWA EARLY THIS MORNING...SO I HAVE OPTED
TO KEEP THE MENTION OF SOME FLURRIES GOING ACROSS THE AREA THROUGH
EARLY AFTERNOON.
WARM AIR ADVECTION/ISENTROPIC ASCENT WILL INCREASE
ACROSS MUCH OF THE MIDWEST AND GREAT LAKES REGION LATER TONIGHT INTO
SUNDAY MORNING IN RESPONSE TO AN INCREASING SOUTHERLY WIND FIELD
AHEAD OF A DEVELOPING STORM SYSTEM ACROSS THE NORTHERN HIGH PLAINS.
IT APPEARS THAT THIS WARM AIR ADVECTION WILL BE ENOUGH TO RESULT IN
THE DEVELOPMENT OF SOME FREEZING DRIZZLE OR LIGHT SNOW. MODEL
SOUNDINGS...ESPECIALLY FROM THE NAM SUGGEST CLOUD HEIGHTS WILL ONLY
REACH TO AROUND -7 DEGREES CELSIUS...SUGGESTING THE POSSIBILITY OF A
DEARTH OF ICE CRYSTALS IN THE CLOUDS. AS SUCH...THIS INCREASES THE
THREAT FOR FREEZING DRIZZLE VERSES LIGHT SNOW. OVERALL...THIS WILL
BE A VERY LIGHT EVENT...AND APPEARS TO MAINLY BE CONFINED ACROSS
NORTH CENTRAL ILLINOIS...THOUGH PORTIONS OF THE CHICAGO AREA COULD
ALSO EXPERIENCE SOME. THE PRIMARY TIMING FOR THIS ACTIVE LOOKS TO
BE AFTER MIDNIGHT TONIGHT THROUGH AROUND MID MORNING ON SUNDAY.
THEREAFTER...SURFACE TEMPERATURES SHOULD WARM ABOVE FREEZING ENDING
THE THREAT OF FREEZING PRECIP.
KJB
&&
.LONG TERM...
347 AM CST
MONDAY THROUGH FRIDAY...
NOT MUCH HAS CHANGED IN THE EXPECTATION OF A TRANSITIONING WEATHER
PATTERN ACROSS THE CONUS SUPPORTIVE OF SEVERAL PERIODS OF INCLEMENT
WEATHER THROUGH MUCH OF THE UPCOMING HOLIDAY WEEK. THEREFORE...THE
MAIN CONCERNS DURING THE LONG TERM PERIOD WILL FOCUS AROUND THE
CHANCES AND TIMING OF RAINFALL MONDAY INTO TUESDAY...THEN THE
POTENTIAL FOR A SIGNIFICANT WINTER STORM SOMEWHERE ACROSS THE GREAT
LAKES REGION INTO CHRISTMAS EVE.
A VERY IMPRESSIVE NORTHERN PACIFIC JET STREAK IS EXPECTED TO DEVELOP
EASTWARD ONSHORE ACROSS THE PACIFIC NORTHWEST BY EARLY SUNDAY...THEN
BEGIN TO DIG A SIGNIFICANT UPPER LEVEL TROUGH ACROSS THE CENTRAL
CONS BY MID WEEK. MODEL GUIDANCE CONTINUES IN GOOD AGREEMENT IN
TRACKING AN INITIAL AREA OF LOW PRESSURE EASTWARD FROM THE NORTHERN
HIGH PLAINS TO THE UPPER MISSISSIPPI VALLEY BY TUESDAY. THIS WOULD
KEEP ALL OF NORTHERN ILLINOIS/NORTHWESTERN INDIANA IN THE WARM
SECTOR THROUGH EARLY TUESDAY...THUS ASIDE FROM A SMALL POSSIBILITY OF
THE PRECIP BEGINNING AS A MIX OF SLEET AND RAIN AT ONSET EARLY
MONDAY...IT APPEARS THAT WE WILL BE IN FOR A RAIN EVENT ACROSS THE
ENTIRE AREA MONDAY AFTERNOON INTO MONDAY NIGHT.
THINGS BEGIN TO GET REALLY TRICKY LATE TUESDAY AND INTO CHRISTMAS
EVE...AS MODEL GUIDANCE IS INSTANT IN SECONDARY VORT MAX DIGGING
SOUTH AND ACROSS THE LOWER MISSISSIPPI VALLEY BY TUESDAY
NIGHT...LEADING TO A VERY AMPLIFIED AND INCREASING NEGATIVELY TILTED
UPPER TROUGH ACROSS THE CENTRAL CONUS. THIS IS A CLASSIC UPPER LEVEL
PATTERN SUPPORTIVE OF TREMENDOUS ATMOSPHERIC DYNAMICS AND HENCE
RAPID AND DEEP CYCLOGENESIS...SOMEWHERE ACROSS THE GREAT LAKES
REGION. IN FACT...THIS COULD RESULT IN "BOMB CYCLOGENESIS"...WHICH IS
DEFINED AS A DEEPENING RATE OF THE LOWS CENTRAL PRESSURE OF 24 MB IN
AS MANY HOURS. MODEL GUIDANCE CONTINUES TO BE IN SOME DISAGREEMENT IN
WHERE EXACTLY THIS STORM SYSTEM WILL TRACK INTO CHRISTMAS EVE.
HOWEVER...SUPPORT IS IN PLACE TO SUGGEST A GOOD POTENTIAL OF A
STRONG STORM SYSTEM ACROSS THE REGION DURING THIS PERIOD.
UNFORTUNATELY...THE ACTUAL TRACK OF THE STORM WILL BE THE DIFFERENCE
IN IF WE END UP WITH LITTLE OR NO SNOW...OR A SIGNIFICANT WINTER
STORM ACROSS THE AREA. THE LIKELIHOOD OF VERY STRONG WINDS WITH SUCH A
DEEP LOW COULD ALSO RESULT IN SIGNIFICANT BLOWING SNOW...IF IT DOES
OF COURSE SNOW THIS FAR WEST. THEREFORE...THIS STORM BEARS
SIGNIFICANT ATTENTION IN THE COMING DAYS.
FOLLOWING THIS SYSTEM...YET ANOTHER STORM SYSTEM COULD TAKE AIM ON
THE AREA BY FRIDAY. HOWEVER...UNCERTAINTY WITH THIS STORM IS
EXTREMELY HIGH...GIVEN THAT THE ACTUAL EVOLUTION OF THE FIRST STORM
SYSTEM WILL NEED TO BE IRONED OUT. OVERALL THOUGH IT LOOKS LIKE WE
ARE ENTERING INTO AN ACTIVE WEATHER PERIOD THROUGH THE REST OF THE
FORECAST PERIOD.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* MVFR CIGS RETURNING THIS EVENING OR OVERNIGHT.
* PATCHY FREEZING DRIZZLE EARLY SUNDAY.
BMD
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE REMAINS OVER THE REGION TODAY RESULTING IN LIGHT
FLOW...HOWEVER WINDS WILL TREND MORE SOUTHERLY THOUGH THE TAF PERIOD
AS THE HIGH DRIFTS EAST OF THE AREA. MVFR CIGS HAVE SCATTERED AND
DRIFTED EAST OF THE TERMINALS THIS MORNING...BUT EXPECT A RETURN OF
THE MVFR THIS EVENING OR OVERNIGHT...THOUGH SPECIFIC TIMING REMAINS
UNCERTAIN. OVERNIGHT...WARM AIR ADVECTION INCREASES JUST OFF THE
DECK AND MAY ALLOW FOR SOME LIGHT FREEZING DRIZZLE TO DEVELOP WITH
SURFACE TEMPS JUST BELOW FREEZING. FORCING IS BEST OVER NORTH
CENTRAL ILLINOIS SO WILL MAINTAIN PROB30 MENTION AT RFD ONLY FOR
NOW. WINDS WILL GRADUALLY INCREASE THROUGH THE DAY SUNDAY AS THE
GRADIENT TIGHTENS AHEAD OF LOW PRESSURE APPROACHING FROM THE
NORTHWEST.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN CIG TRENDS BUT LOW IN TIMING.
* LOW CONFIDENCE IN FREEZING DRIZZLE.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...DRY...MAINLY VFR.
MONDAY...RAIN AND MVFR LIKELY. BREEZY SOUTH-SOUTHEAST WINDS.
TUESDAY...CHANCE OF RAIN. MVFR POSSIBLE. SOUTH WINDS BECOMING WEST.
WEDNESDAY...CHANCE OF SNOW. MVFR/IFR POSSIBLE. NORTHWEST WINDS
BECOMING GUSTY FROM THE WEST.
THURSDAY...DRY. MAINLY VFR. GUSTY WEST WINDS DIMINISHING.
FRIDAY...CHANCE OF RAIN OR SNOW. MVFR POSSIBLE. LIGHT EAST WINDS
BECOMING WEST.
RATZER
&&
.MARINE...
137 AM CST
THE MAIN MARINE FORECAST CONCERNS THIS MORNING FOCUS ON A COUPLE OF
PERIODS OF STRONG WINDS OVER THE NEXT SEVERAL DAYS...SOUTH AND
SOUTHEAST WINDS 25-30 KT DEVELOPING SUNDAY AND CONTINUING THROUGH
MONDAY EVENING...THEN THE POTENTIAL FOR WEST HIGH GALES LATE
WEDNESDAY THROUGH THURSDAY...CHRISTMAS EVE AND CHRISTMAS DAY.
IN THE NEAR TERM...WEATHER IS QUITE TRANQUIL ACROSS LAKE MICHIGAN
THIS MORNING AS DIFFUSE HIGH PRESSURE WAS DRIFTING SLOWLY EAST
ACROSS THE REGION. THE RIDGE AXIS WILL SHIFT EAST OF THE LAKE THIS
AFTERNOON ALLOWING CURRENT VARIABLE WINDS TO BECOME SOUTHERLY. SOUTH
WINDS WILL GRADUALLY INCREASE LATE TONIGHT AND SUNDAY AS AN AREA OF
LOW PRESSURE DEVELOPS SOUTHEAST IN THE LEE OF THE NORTHERN ROCKIES
WITH A CORRESPONDING TIGHTENING OF THE SURFACE PRESSURE GRADIENT
BETWEEN THE LOW AND THE HIGH TO EAST OF THE LAKES. MODEL FORECAST
SOUNDINGS SUPPORT WINDS 20-25 KT SUNDAY AFTERNOON INCREASING TO 30
KT SUNDAY NIGHT/MONDAY...BECOMING A BIT MORE SOUTHEAST LATE MONDAY
AS THE SURFACE LOW MOVES INTO THE UPPER MIDWEST.
THE SURFACE LOW IS EXPECTED TO FILL A BIT ACROSS THE REGION TUESDAY
AS IT OCCLUDES. MODEL FORECASTS CONTINUE TO DEPICT A COMPLEX
EVOLUTION BY MID-WEEK HOWEVER...WITH A SECOND AREA OF LOW PRESSURE
FARTHER SOUTH ALONG THE COLD FRONT DEEPENING AND WRAPPING NORTHWARD
INTO THE GREAT LAKES WEDNESDAY AND THURSDAY. SPREAD REMAINS AMONGST
MODEL FORECASTS OF THE EXACT TRACK AND DEPTH OF THIS LOW...BUT IT
DOES APPEAR THAT A DEEPENING SUB-980 MB LOW WILL TRACK NORTH ACROSS
THE GREAT LAKES REGION CHRISTMAS EVE INTO CHRISTMAS DAY. SUCH A LOW
PASSING EAST OF LAKE MICHIGAN SUPPORTS THE POTENTIAL FOR THE
DEVELOPMENT OF WESTERLY GALES ON THE LAKE...PERHAPS HIGH GALES ABOVE
40 KT...FROM WEDNESDAY AFTERNOON OR EVENING THROUGH THE DAY
THURSDAY.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1140 AM CST Sat Dec 20 2014
.UPDATE...
ISSUED AT 1045 AM CST SAT DEC 20 2014
Short-wave trough evident on latest water vapor imagery across
north-central Illinois will continue to track eastward out of the
area this afternoon. Despite weak synoptic lift associated with
this feature, little or no light precip has been observed. Clouds
blanket central Illinois, with lower clouds/fog remaining further
west across Iowa into northern/central Missouri. 16z LAPS soundings
show a dry layer below 900mb, which is not conducive for drizzle.
As a result, have removed the drizzle/flurry mention across the
far northern KILX CWA this morning. Will generally be a cloudy and
cold day across central Illinois: however, a few breaks in the
overcast will be possible from time to time. As low-level flow
gradually veers more southwesterly, lower clouds/drizzle/fog
currently west of the Mississippi River will spill eastward into
the Illinois River Valley tonight.
&&
.SHORT TERM...(Today)
ISSUED AT 507 AM CST SAT DEC 20 2014
Latest satellite data indicating a shortwave trof near Omaha which
is expected to push across our area later this morning. Upstream
surface observations across central and east central Iowa have had
some reports of some very light freezing drizzle and flurries to the
east of the main area of lift, with even some very light flurries
reported this past hour in St. Louis. A secondary shortwave was
noted over parts of southern Missouri into the lower Ohio Valley
that has produced a band of light snow which extended along and
south of the I-70 corridor early this morning. That system will
shift off to our east over the next few hours taking the light snow
out of southeast Illinois by dawn.
As the compact shortwave over the Missouri Valley tracks across the
area, many of the forecast soundings are not showing much in the way
of support for widespread precip as high pressure at the surface is
still holding firm over east central Illinois this morning. We see
moisture in the 850-800 mb layer over most of the area with not a
great deal above that until later this morning when the main area of
lift associated with the vort max swings thru. Much of the stratus/low
level moisture will remain to our west thru the morning as well before
tracking slowing into west central Illinois this afternoon. Will carry
chances for flurries this morning, mainly over west central Illinois
ahead of the vort max, as we see some mid level moisture/lift track
just to the west of our forecast area. Most of the short term high
resolution models continue to suggest as the shortwave moves across
the remainder of the state, moisture profiles will not support much
in the way of precip further east this afternoon. Despite the more
widespread cloud cover over our area today, we should see afternoon
temperatures a few degrees warmer than yesterday with readings
ranging from the mid 30s north to around 40 south.
&&
.LONG TERM...(Tonight through Friday)
ISSUED AT 507 AM CST SAT DEC 20 2014
Fairly quiet weather expected tonight through Sunday night across
central and southeast IL as surface ridge shifts east into New
England and the mid Atlantic states Sunday. Temps to gradually
modify next few days with increasing southerly flow especially by
Monday. Added patchy drizzle/freezing drizzle to the IL river valley
overnight with the low clouds as surface temps are close to
freezing. Mostly cloudy skies expected Sunday with more low clouds
prevailing over northern counties. Highs in the lower 40s Sunday
which will be a bit above normal highs in the mid to upper 30s.
Added slight chance of light rain late Sunday night around Galesburg
with best rain chances arriving during the day Monday especially by
Monday afternoon NW areas and Monday night into Tue across area.
Strong low pressure near Pacific NW to track into MN Monday night
and increase chances of rain over IL ahead of approaching low
pressure and cold front. Milder highs in the 40s Monday and Tue with
Lawrenceville around 50F.
Forecast models then deepen another area of low pressure from the
southern plains into KY by dawn Wed and then into eastern lower MI
or just east of there by sunset Wed. Colder air to be drawn into IL
Tue night and Wed with rain changing to snow during Tue night and
continue good chances of light snow Wed. Could be some light snow
accumulations overnight Tue night into Wed especially over
eastcentral IL. Windy conditions expected Wed and Wed night as
deepening low pulls away with strong west winds gusting 25-35 mph.
Dry conditions expected on Christmas Day over the state as IL will
be in between strong low pressure exiting into eastern Canada and new
low pressure developing over Texas Panhandle by sunset Thu. This low
pressure ejects ne into the western Great Lakes by sunset Friday and
returns good chances of precipitation with southeast IL mainly rain
and a mix of rain/snow over central IL. Extended models show active
weather pattern looks to continue beyond day 7.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 1140 AM CST SAT DEC 20 2014
MVFR ceilings will gradually spread across central Illinois this
afternoon/evening. 17z/11am obs show MVFR conditions
along/southwest of a KGBG to KSPI line, with VFR ceilings further
east across the remainder of the area. As light S/SE flow
gradually becomes more S/SW, these lower clouds will return to all
terminals by evening. Based on the latest HRRR output, have
introduced MVFR at KPIA by 21z, then further east to KCMI by 03z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Barnes
SHORT TERM...Smith
LONG TERM...07
AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1111 AM CST SAT DEC 20 2014
...UPDATE TO AVIATION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM CST SAT DEC 20 2014
WEAK SHORTWAVE TROUGHS ARE PERIODICALLY PROGRESSING ACROSS THE
PLAINS FROM THE WEST. ONE SUCH MINOR WAVE WILL MOVE ACROSS THE
SOUTHERN PLAINS BY TONIGHT. HOWEVER, LEE TROUGHING IN RESPONSE TO
WESTERLY FLOW AT MID LEVELS SEEMS TO BE THE DOMINANT FEATURE THAT
IS AFFECTING THE LOW LEVEL WIND FIELD. EARLY MORNING SATELLITE AND
SURFACE OBSERVATIONS INDICATE LOW STRATUS ACROSS THE SOUTHERN
PLAINS AS FAR NORTH AS PERRYTON AND MEDICINE LODGE. AS SURFACE
TROUGHING ENCOURAGES SOUTHERLY WINDS TODAY, THIS LOW LEVEL
MOISTURE SHOULD PROGRESS NORTHWARD INTO LOCATIONS FROM DODGE CITY
SOUTH AND EAST TO THE OKLAHOMA BORDER. THE NAM HAS A CHARACTERISTIC
BIAS OF BEING TOO DRY AND WARM AT LOWER LEVELS IN CASES SUCH AS
THIS. THE HRRR AND RAP ARE COOLER AND INDICATE LOW CLOUD COVER
PROGRESSING AS FAR NORTH AS DODGE CITY BY EARLY AFTERNOON. CLOUD
COVER WILL TEND TO KEEP DIURNAL RANGES LOWER AND TEMPERATURES
COOLER IN THE AFTERNOON. AS AN EXAMPLE, THE TEMPERATURE AT GAGE,
OKLAHOMA STAYED 41F FROM FRIDAY AFTERNOON THROUGH EARLY THIS
MORNING AS A RESULT OF THE STRATUS. TEMPERATURES SHOULD BE WARMER
TODAY IN LOCATIONS SUCH AS SCOTT CITY AND WAKEENEY WHERE PLENTY OF
SUNSHINE IS EXPECTED. LOW STRATUS WILL PERSIST OR INCREASE IN
AREAL COVERAGE TONIGHT, AND FOG IS POSSIBLE ON THE WESTERN
PERIPHERY OF THE CLOUD SHIELD, SOME OF WHICH COULD BE LOCALLY
DENSE. THE CLOUD COVER AND HIGHER DEWPOINTS OUGHT TO KEEP
TEMPERATURES FROM FALLING A LOT TONIGHT, EXCEPT FOR WEST CENTRAL
KANSAS WHERE LESS CLOUD COVER IS EXPECTED.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 412 AM CST SAT DEC 20 2014
AT THE BEGINNING OF THE EXTENDED PERIOD ON SUNDAY, A SHORTWAVE
TROUGH WILL BE MOVING OUT OF THE WESTERN HIGH PLAINS ACROSS KANSAS.
A SURFACE TROUGH OVER EASTERN COLORADO COULD MOVE OUT INTO FAR
WESTERN KANSAS DURING THE DAY. LOW LEVEL WINDS WILL TAKE ON A MORE
SOUTHWESTERLY DOWNSLOPE FLOW COMPONENT DURING THE DAY IN THAT AREA
AND HELP BOOST TEMPERATURES INTO THE MID/UPPER 50S. FARTHER EAST
ACROSS SOUTHWEST INTO SOUTH CENTRAL KANSAS LOW STRATUS WILL LIKELY
BE IN PLACE DUE TO CONTINUED MOIST SOUTHERLY FLOW. WHILE THE STRATUS
WILL LIKELY ERODE SOMEWHAT DURING THE DAY, AREAS AROUND SOUTH
CENTRAL KANSAS WILL LIKELY STAY SOCKED IN WITH LOW CLOUDS.
BY MONDAY MORNING, A STRENGTHENING UPPER LEVEL SHORTWAVE TROUGH WILL
MOVE FROM SOUTHWEST CANADA AND DEVELOP INTO A CLOSED LOW OVER
SOUTHEAST SOUTH DAKOTA. AS THIS LOW CONTINUES INTO THE MIDWEST
STATES DURING THE DAY, A SHORTWAVE TROUGH WILL DIG SOUTH ACROSS THE
EASTERN ROCKIES AND ADJACENT HIGH PLAINS AND PUSH A COLD FRONT SOUTH
ACROSS WESTERN KANSAS. THE MODELS CONTINUE TO SHOW PRECIPITATION
DEVELOPING ALONG THE FRONT ALONG WITH SOME LINGERING UPSLOPE
PRECIPITATION OVER EASTERN COLORADO AND FAR WESTERN KANSAS DURING
THE DAY. TEMPERATURE PROFILES CONTINUE TO SUGGEST THAT PRECIPITATION
SHOULD MAINLY BE LIQUID. BY MONDAY NIGHT THE MAIN UPPER LEVEL ENERGY
WITH THE WAVE DROPS INTO NEW MEXICO AND WEST TEXAS. FARTHER NORTH
THE TROUGH SWINGS OUT ACROSS THE HIGH PLAINS. THIS COULD BRING A
FEW FLURRIES TO WEST CENTRAL KANSAS LATE MONDAY NIGHT. WILL CARRY
SOME SLIGHT CHANCE POPS FOR THIS.
THE MODELS CONTINUE TO SHOW UNIDIRECTIONAL NORTHERLY FLOW DEVELOPING
THROUGH THE LOWER TO MIDDLE LEVELS OVER THE HIGH PLAINS LATE MONDAY
NIGHT AND CONTINUING INTO TUESDAY. BLUSTERY CONDITIONS WILL DEVELOP
BY EARLY MORNING TUESDAY AND CONTINUE THROUGH THE DAY. SOME 40 TO 45
MPH GUSTS WILL BE POSSIBLE DURING THE DAY.
UPPER LEVEL RIDGING WILL DEVELOP OVER THE CENTRAL HIGH PLAINS
THROUGH THE MIDDLE PART OF THE WEEK AS THE EARLY WEEK SYSTEM MOVES
INTO THE EASTERN CONUS AND ANOTHER WAVE DROPS INTO THE NORTHERN
ROCKIES. THIS NEXT WAVE COULD BRING RAIN OR SNOW TO WESTERN KANSAS
BY AS EARLY AS CHRISTMAS DAY. THE GLOBAL MODELS CONTINUE TO SHOW
SIGNIFICANT RUN TO RUN VARIABILITY WITH THIS WAVE, HOWEVER. AFTER
COLLABORATING WITH SOME OF THE SURROUNDING OFFICES, HAVE INTRODUCED
SOME SMALL POPS FOR RAIN OR SNOW TO CENTRAL KANSAS NEXT THURSDAY
NIGHT AND FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1111 AM CST SAT DEC 20 2014
FORECAST CONCERN IS THE PROBABILITY OF DENSE FOG. HAVE INSERTED 1/4SM
AND FG FOR KGCK/KDDC. CONFIDENCE IS LOWER FOR KHYS. THE LIFR CONDITIONS
SHOULD BEGIN TO IMPROVE BY 15Z TOMORROW. WINDS WILL BE SOUTHERLY
TO SOUTHWESTERLY 5-10 KT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 46 33 45 34 / 0 0 10 10
GCK 50 27 50 32 / 0 0 10 10
EHA 51 27 57 34 / 0 0 0 20
LBL 48 31 51 33 / 0 0 0 10
HYS 49 31 48 34 / 0 0 10 10
P28 47 37 47 36 / 0 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...FINCH
LONG TERM...GERARD
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1208 PM EST Sat Dec 20 2014
...Updated Aviation Discussion...
...Forecast Update...
Issued at 1025 AM EST Sat Dec 20 2014
Main forcing that brought light snow to the area this morning has
moved off into Ohio, so the remainder of the day is expected to be
dry. The afternoon forecast is largely on track, though the
challenge is cloud cover. Models are not handling the low/mid level
moisture very well at all as there is a large, although thin, deck
of clouds upstream. The HRRR seems to have a somewhat decent handle
on the current situation, so trended the forecast in that direction,
but went more pessimistic given current satellite and low sun angle
this time of year. This gives more of an cloudy/overcast afternoon
to the area, though there could be some breaks along/south of the KY
parkways. As a result of the increased clouds, lowered high
temperatures a degree or two.
Issued at 815 AM EST Sat Dec 20 2014
Radar returns, automated observations and spotter reports confirm
that the light snow continues across the Louisville metro area and
points north and east. With temperatures remaining in the upper 20s
to around 30, slick spots on untreated roads, particularly bridges
and overpasses could develop. Adjusted forecast grids and continued
SPS for portions of the area.
The main forcing for this activity is an upper level shortwave and
this is rapidly moving out of the area, so I`m expecting this
activity to end west to east over the next few hours.
Issued at 542 AM EST Sat Dec 20 2014
Light snow continues across portions of southern IN and north
central KY this morning. Some light accumulations have been reported
on cars and area roadways this morning for this activity. Updated
the grids to reflect current radar trends and issued an SPS talking
about slick spots. Still think most of this activity should move out
of the area by around sunrise.
.SHORT TERM (Now through Sunday)...
Issued at 307 AM EST Sat Dec 20 2014
Some light radar returns continue to show up across southern Indiana
and portions of north central Kentucky this morning associated with
a weak PV anomaly. Some light snow may reach the ground under
the strongest echoes, as it did here at the office. However, the
most that is expected is a very light dusting on elevated surfaces.
This activity will continue to push off to the northeast over the
next few hours and should be out of the area by sunrise.
Clouds will stick around for much of the day but should begin to
clear by late afternoon into the evening. High pressure ridging in
from the northeast will keep the area dry through Sunday. Highs
today will range from the upper 30s in the north to the mid 40s in
the south. Tomorrow will be a bit warmer with highs ranging from the
mid 40s to around 50. Lows tonight will be in the mid to upper 20s.
.LONG TERM (Sunday night through Friday)...
Issued at 332 AM EST Sat Dec 20 2014
Sunday night through Tuesday Night...
Medium range deterministic guidance continues to be in good
agreement with the overall pattern as head into the late weekend and
into early next week. The upper pattern at the beginning of the
period will feature a broad trough over the inter-mountain west with
ridging along both coasts. This will place the Ohio Valley in a
broad southwesterly flow aloft early in the period. As we move into
Monday, the multi-model consensus continues to suggest that the
ridge over the eastern Pacific will build northward into western
Canada. As this occurs, the Pacific jet will pound it`s way into
Canada and then drop into the Plains. This will lead to the broad
trough over the inter-mountain west to deepen and close off by
Monday afternoon. The trough is expected to deepen further
resulting in cyclogenesis over Texas. This surface low will deepen
as well as it heads NE into the Ohio Valley by late Tuesday night.
We`ll see dry conditions initially in our region at the beginning of
the period, but rain chances will quickly ramp up on Monday as the
broad southwesterly flow pushes quite a bit of moisture up into our
region. Precipitable water amounts of nearly 1.25 inches look to
be in our vicinity by Tuesday afternoon which is +2 standard
deviations above normal. Thus, some of the rainfall could be heavy
at times from Monday afternoon through Tuesday night. With us
remaining in the southwest flow, temperatures will be rather mild
through this portion of the forecast period. Lows Sunday night will
drop into the lower-middle 30s with highs on Monday warming into the
lower 50s in the north with lower-middle 50s across the south.
Temps will cool off just a bit Monday night with lows mainly in the
lower-mid 40s. Tuesday look like to be the mildest day of the
period with highs pushing into the upper 50s. Given the deepening
system and broad southwesterly flow, these numbers for Tuesday are
probably too conservative, and we may see some lower 60 degree
readings down across southern KY. Some colder air will start to
wrap in late Tuesday night with lows crashing into the mid 30s in
the west with mid-upper 40s in the east.
Wednesday through Friday...
...Very Active Period of Weather Likely for Christmas Eve and into
early Christmas Day...
Latest long term model guidance has been trending westward with the
overall track of the surface low. The Canadian GEM has been leading
the pack on the westward shift, and the Euro and GFS solutions have
now trended more west with the low. By Wednesday morning, low
pressure should be in east-central Kentucky with a rather large
precipitation shield encompassing much of the region. The pressure
gradient will rapidly increase during the morning hours with
sustained winds ramping up to 10-20 MPH by the early afternoon
hours. The surface low is expected to rapidly intensify during the
afternoon as it races from east-central KY into western Ontario.
Based on the multi-model consensus, we could see the system deepen
by 20+ millibars within a 24 hour period. As the low pulls away
from the region, we will see winds shift to the northwest and remain
quite elevated with sustained winds of 10-20 MPH and gusts up to
35-40 MPH. Thermal profiles are slightly warmer during the day
suggestive that much of the precipitation behind the system will be
in the form of rain. Highs early in the day will be in the upper
30s in the west to the lower-mid 40s in the east and then fall
during the afternoon.
By Christmas Eve, we will see temperature profiles crash from west
to east resulting in a quick change over to snow showers. Very
blustery and cold conditions look increasingly likely for Christmas
eve with widespread snow shower activity in progress across the
region. Model soundings continue to show very steep low-level lapse
rates with plenty of moisture in the ice crystal producing layer.
Thus, some snow showers may capable of producing moderate snow at
times during the evening. While temperatures drop to near freezing,
there will be an opportunity for some minor accumulations. Given
the relatively warm ground and recent rainfall, any snowfall
accumulation will be dependent upon the intensity of the snow
showers.
The models continue to trend a little faster with the moisture pull
off to the northeast early Christmas morning. Current thinking is
that we`ll still have some snow shower activity past midnight, but
then rapidly diminish by sunrise. The flow aloft looks to quickly
revert back to zonal flow which will likely push some drier air into
the region resulting clearing skies during the day. Temperatures
will be challenging depending on how fast skies clear. The clear
trend in the models has been warmer, so we have adjusted
temperatures slightly upwards with highs in the upper 30s in the
north to the lower-mid 40s across the south.
Generally dry conditions are expected for Friday. However, another
quick moving system will be pushing into the region by the late part
of the period. Temps on Friday may be quite mild within the return
flow regime with upper 40s to lower 50s being possible. A period of
rain showers looks increasingly likely for Friday night with colder
conditions returning by Saturday.
&&
.AVIATION (18Z TAF Update)...
Issued at 1204 PM EST Sat Dec 20 2014
Much of the area around SDF/LEX/BWG remains VFR at this hour with
2000-2500 ft MVFR ceilings across southern Indiana and southwest
Ohio. Expecting VFR clouds to persist through the period with
light/variable winds this evening becoming more northeasterly to
easterly overnight. There are some indications that clouds could
scatter out overnight into Sunday morning, especially at BWG. Less
confident at SDF/LEX. If clouds do scatter out, the baggy wind field
and residual low-level moisture could result in light fog.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........ZBT
Short Term.....EER
Long Term......MJ
Aviation.......ZBT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
129 PM EST SAT DEC 20 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 434 AM EST SAT DEC 20 2014
WV LOOP AND 00Z RAOBS SHOW A LARGE SCALE ZONAL FLOW...BUT THERE IS
EMBEDDED AMPLIFICATION. TROUGHING WAS AS CLOSE BY AS NORTHERN PLAINS
AND MINNESOTA THIS MORNING. PRIMARY PV ANAMOLIES/SHORTWAVES WITHIN
TROUGH WERE OVER FAR NORTHWEST ONTARIO AND OVER WESTERN IOWA. WEAK
SFC TROUGH NOTED OVER WESTERN MINNESOTA TOO...WHILE SFC RIDGING
EXTENDING OUT OF QUEBEC WAS STILL MAIN FEATURE OVER GREAT LAKES. THE
ONTARIO WAVE AND WEAK WARM AIR ADVECTION AHEAD OF THE MINNESOTA
TROUGH AND UPSLOPE LOW-LEVEL FLOW IS SUPPORTING LGT WINTRY MIX OF
SNOW AND FREEZING DRIZZLE OVER NORTHERN MINNESOTA THIS MORNING. ONLY
AFFECT FM ONTARIO SHORTWAVE OVER UPR MICHIGAN IS BATCH OF MID CLOUDS
OVER WEST HALF OF CWA. NO PRECIP THROUGH. ONLY WEATHER OF NOTE IN
THE CWA THIS MORNING IS PATCHY DENSE FOG OVER CNTRL CWA...VCNTY OF
IMT TO SAW.
ONTARIO WAVE MOVES LITTLE EASTWARD TODAY AS ANOTHER SHORTWAVE
CURRENTLY OVER MT TRIES TO CATCH UP WITH IT. THUS...SFC TROUGH AND
WARM AIR ADVECTION STAY MAINLY OVER MN. RAP SHOWS WEAK LIFT TRYING
TO IMPACT KEWEENAW THIS MORNING INTO EARLY AFTN...BUT IT LOOKS MUCH
DRIER THAN IT IS UPSTREAM OVER MN WHERE PRECIP IN OCCURRING THIS
MORNING...SO NOT EXPECTING ANY PRECIP OUT OF THIS FOR OUR AREA. LOW
CLOUDS OVER NW WI AND WEST UPR MICHIGAN GRADUALLY EASE
EASTWARD...BUT A FEW SPOTS IN EAST HALF OF CWA MAY STAY CLEAR OF THE
LOW CLOUDS ALL DAY. TOUGH TO SAY EXACTLY WHERE THOUGH AS THERE ARE
DIFFERENT AREAS OF CLOUDS AFFECTING THE AREA AND MODELS FORECASTING
OF THEM IS ONLY FAIR. FOR TEMPS...WENT AT OR 1-2 DEGREES ABOVE
FRIDAY READINGS AS 925MB TEMPS WARM SLIGHTLY COMPARED TO FRIDAY.
WHERE SUNSHINE CAN PERSIST INTO THE AFTN...TEMPS COULD BUMP INTO THE
MID 30S. BEST SHOT AT THAT WOULD BE EAST CENTRAL CWA...VCTY OF
MUNISING AND GRAND MARAIS. FARTHER WEST...CLOUDS WILL HOLD TEMPS
DOWN OVER INTERIOR WEST TO UPR 20S. INTO THIS EVENING...EXPECT LOW
CLOUDS /HIGHER 925MB-850MB RH/ TO BE OVER WEST HALF OF CWA AND ALSO
THE FAR EAST CWA. EVENTUALLY THOUGH...CLOUDS SHOULD FILL IN OVER ALL
CWA. UNTIL THAT OCCURS...TEMPS FOR INTERIOR CNTRL CWA OR AT LEAST
PORTIONS OF THESE AREAS MAY DROP OFF QUICKLY. CLOSEST MODEL TO
INCICATE THAT WAS BIAS CORRECTED NAM MOS. TWEAKED DOWN EVEN FURTHER
THOUGH /LOW TEENS/ SEEING HOW MUCH TEMPS FELL EARLY THIS MORNING
WHERE SKIES WERE CLEAR. ALSO WILL ADD FOG TO THOSE AREAS SINCE THESE
TEMPS WILL BE WELL BELOW THE EXPECTED AFTN DWPNTS. WHERE CLOUDS STAY
IN ALL NIGHT...MIN TEMPS LIKELY STAY ABOVE 20 DEGREES.
SOUNDINGS FM NAM AND GFS INDICATE INCREASING SUB 950MB MOISTURE
LATE TONIGHT FM THE SOUTH AND WITH UPSLOPE SOUTH FLOW OVER CNTRL
CWA COULD SEE PATCHY FREEZING DRIZZLE IMT TO NEGAUNEE. NOT MUCH UVM
SHOWN ON THE SOUNDINGS THOUGH...SO LEFT IT OUT OF GRIDS ATTM.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 434 AM EST SAT DEC 20 2014
MAIN FOCUS FOR THE LONGER TERM REMAINS THE POTENTIAL FOR SOME SN OR
MIXED PCPN IN THE MON INTO XMAS PERIOD ASSOCIATED WITH A DEEPENING
UPR TROF IN THE CENTRAL CONUS AS A SERIES OF SHRTWVS RIDING OVER A
MEAN RDG ALONG THE W COAST DIG INTO THE PLAINS. THE STRONGEST OF
THESE DISTURBANCE IS NOW OVER THE NE PACIFIC OCEAN. ALTHOUGH THE
MODELS ARE COMING INTO BETTER AGREEMENT ON WARMER LLVL TEMPS IN THE
TUE/WED TIME AND ON THE DEVELOPMENT OF A LO PRES IN THE LO/MID MS
RIVER VALLEY THAT WL TRACK SOMEWHERE NEAR THE CENTRAL GREAT LKS ON
WED AND INTO CANADA ON XMAS DAY...THERE ARE STILL SOME SIGNIFICANT
DIFFERENCES ON THE DETAILS OF HOW THE INTERACTION/PHASING BTWN THESE
SEPARATE DISTURBANCES THAT ARE STILL OVER THE DATA POOR PACIFIC WL
IMPACT THE SFC LO TRACK AND UPR MI.
SUN/SUN NIGHT...AS LLVL S WIND BTWN DEPARTING HI PRES IN SE CANADA
AND FALLING MSLP TO THE W ADVECT MOISTER LLVL AIR INTO THE CWA...
OPTED TO INCLUCE SOME FREEZING DZ OVER THE SCENTRAL IN THE MRNG
WHERE LLVL WIND WL UPSLOPE OFF LK MI. THEN OPERATIONAL MODELS SHOW A
SHRTWV MOVING E FM THE NRN PLAINS ACROSS THE NW GREAT LKS AND INTO
NW ONTARIO BY 12Z MON... BRINGING A PERIOD OF DEEP LYR QVECTOR CNVGC
ASSOCIATED WITH SOME DPVA AND ISENTROPIC ASCENT BEST DEPICTED ON THE
285-290K SFCS /ABOUT H85-75/ IN THE STRONGER SSW FLOW BTWN HI PRES
OVER THE CNDN MARITIMES AND LO PRES IN THE NRN PLAINS. ARRIVAL OF
THE DEEPER MSTR SHOULD END THE FREEZING DZ. THE BULK OF THE GUIDANCE
INDICATES THE ACCOMPANYING SN WL BEGIN OVER THE SCENTRAL SUN AFTN
AND THEN OVERSPREAD THE REST OF THE FA THRU SUN NGT. THE NAM SHOWS
THE HIEST QPF UP TO 0.25-0.30 INCH OVER THE SCENTRAL...WHERE THE
NEAR SFC SSE FLOW WL UPSLOPE OFF LK MI AND H85 MSTR CNVGC IS A BIT
SHARPER. THE GFS ON THE OTHER HAND SHIFTS THE HIER QPF TO OVER THE
NW CWA LATE AT NGT. GIVEN THE GREATER CONSISTENCY OF THE NAM WITH
PREVIOUS FCST GUIDANCE...TENDED TOWARD THAT MODEL SCENARIO. WL BUMP
POPS UP TO LIKELY OVER THE SCENTRAL CENTERED ARND SUN EVNG WHEN THE
FORCING WL BE GREATEST. THERE COULD BE A FEW INCHES OF SN ACCUM IN
THIS AREA AS WELL. SSW FLOW UP THE LENGTH OF LK MI MAY SUPPORT SOME
HIER POPS OVER THE E...BUT MARGINAL CHILL OF THE AIRMASS FOR LK
ENHANCEMENT WITH H85 TEMPS RISING TO -5C BY 00Z MON SHOULD LIMIT THE
POTENTIAL FOR A SGNFT IMPACT. TEMPS WL REMAIN ABOVE NORMAL...
ESPECIALLY ON SUN NGT WITH CLD COVER AND A STEADY S WIND GREATLY
LIMITING THE DIURNAL TEMP FALL.
MON...FOLLOWING THE EXIT OF THE SHRTWV INTO NW ONTARIO ON MON AND
THE ARRIVAL OF SOME MID LVL DRYING ASSOCIATED WITH A SHRTWV RDG AXIS
ROTATING NEWD THRU THE NW GREAT LKS TO THE E OF THE DEEPENING UPR
TROF IN THE PLAINS...EXPECT DIMINISHED POPS. BUT PERSISTENT WAA IN
THE DEEP S FLOW BTWN LO PRES SLIDING SEWD THRU THE NRN PLAINS AND HI
PRES OVER THE CNDN MARITIMES WL CAUSE LOTS OF CLDS AND CONTINUED LO
CHC POPS. AS THE LLVLS WARM INTO THE 30S ESPECIALLY NEAR THE WARMING
INFLUENCE OF THE GREAT LKS...LIGHT PCPN MAY INCLUDE A MIX OF RA AND
SN.
MON NGT/TUE...THE 00Z GFS REMAINS CONSISTENT ON SHOWING A CLOSED H5
LO WITHIN THE DEEPENING CENTRAL CONUS TROF/DEEPER SFC LO PRES MOVING
INTO THE UPR LKS DURING THIS TIME ALONG WITH HIER H85 TEMPS UP TO
ARND 0C. THE 12Z/00Z ECMWF MODELS ON THE OTHER HAND HOLD THE CLOSED
H5 LO/SFC LO FARTHER TO THE SW...WITH A SLOWER ARRIVAL OF DEEPER
MSTR AND LOWER H85 TEMPS. BOTH MODELS SHOW DISTURBANCES DIGGING SEWD
TO THE E OF THE UPR RDG ACROSS THE W DEEPENING THE PLAINS TROF.
SINCE THIS GREATER FORCING INTO THE SRN PLAINS SHOULD TEND TO HOLD
THE CLOSED LO THE SW...WL TEND TOWARD THE 12Z ECMWF SCENARIO. THIS
MODEL SHOWS DEEPER MSTR ARRIVING LATE MON NGT AND PERSISTING THRU
TUE AS THE WEAKER SHRTWV LIFTS NEWD AWAY FM CLOSED LO TO THE SW.
ALTHOUGH THE 00Z ECMWF H85 TEMPS ARE LOWER THAN FCST BY THE GFS...
THE FCST H100-85 THKNS IS ONLY A BIT LOWER THAN THE GFS FCST. A LOOK
AT THE 00Z ECMWF FCST SDNGS SHOW A TREND TOWARD A WARMER NEAR SFC
LYR THAT WOULD SUPPORT MORE RA...AS SHOWN BY RECENT GFS RUNS. SO
TENDED TO RAISE FCST TEMPS AND INCLUDE A GREATER AREA OF AT LEAST A
MIX WITH RA. THE FCST SDNGS FM NEITHER MODEL SHOW AN ELEVATED WARM
LYR...SO THE PCPN SHOULD BE RA OR SN. ADDED A MENTION OF SOME FOG
DURING THE MON NIGHT/TUE TIME TO REFLECT THE RA/HIER TEMPS AND
DEWPTS OVER A MELTING SN PACK AT MANY LOCATIONS THAT UPSLOPE OFF LK
MI IN THE EXPECTED LLVL SE FLOW. THIS MIXED PCPN WL TEND TO DIMINISH
ON TUE NGT AS SOME UPR DRYING FOLLOWS THE SHRTWV EXITING NNEWD INTO
ONTARIO.
WED/THU...THE LONGER RANGE MODELS ARE BEGINNING TO COME INTO BETTER
AGREEMENT ON SHOWING A SECOND LO DVLPG IN THE LOWER TO MID MS RIVER
VALLEY ON TUE AT THE SRN END OF THE DEEPING CENTRAL CONUS TROF AND
THEN MOVING NNE INTO THE CENTRAL GREAT LKS ON WED AND THEN INTO ERN
ONTARIO ON XMAS DAY WHILE DEEPENING SIGNIFICANTLY AS THE UPR TROF
TAKES ON A MORE NEGATIVE TILT. NOT SURPRISINGLY...THE EXACT TRACK OF
THE SFC LO...WHICH WL MAKE A SGNFT DIFFERNCE ON PTYPE/PCPN TOTALS
OVER UPR MI...IS STILL UNCERTAIN. THE 00Z GFS INDICATES A FARTHER W
TRACK ACROSS THE ERN U.P. THAN THE 00Z ECMWF/UKMET RUNS...BUT THE
GFS INDICATES THE PCPN WOULD BE HEAVY SN OVER THE W HALF OF UPR MI.
THE FARTHER E ECMWF MODEL GENERATES MUCH LIGHT PCPN OVER THE E.
CONSIDERING THE SGNFT DIFFERNCES THAT REMAIN...RELIED ON THE MODEL
CONSENSUS FOR THE FCST DETAILS. THIS CONSENSUS SUPPORTS HIER POPS
OVER THE E WITH A CHANGE IN PTYPE FM MIXED RA/SN TO MAINLY SN AS THE
INCREASING N BACKING NW WINDS ADVECT COLDER AIR INTO THE CWA.
IN THE WAKE OF THE DEEPENING LO MOVING INTO ONTARIO ON XMAS DAY...
THE PRES GRADIENT IS PROGGED TO TIGTHEN SGNFTLY AND H925 WINDS
INCREASE TO NEAR 45 KTS. NW WIND GUSTS MAY AT LEAST APRCH ADVY
CRITERIA...ESPECIALLY AT EXPOSED LOCATIONS NEAR LK SUP.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 129 PM EST SAT DEC 20 2014
MVFR CEILINGS AND VIS SHOULD BE THE RULE THROUGH THE PERIOD. LIGHT S
WINDS WILL BE ON THE INCREASE DURING THE DAY SUNDAY...BUT REMAIN
AROUND 10KTS OR LESS THROUGH 18Z. THIS WILL BE IN RESPONSE TO THE
LARGE AREA OF HIGH PRESSURE TO OUR E CONTINUING TO EXIT TO E QUEBEC
AND THE NEW ENGLAND STATES. ON SUNDAY THE NEXT LOW PRESSURE SYSTEM
WILL BE NEARING FROM ALBERTA/SASKATCHEWAN/MONTANA.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 434 AM EST SAT DEC 20 2014
EXPECT S WINDS UNDER 20 KTS ASSOCIATED WITH HI PRES DRIFTING E THRU
SE CANADA TO PERSIST INTO SUN. THE S WINDS WILL INCREASE UP TO 25
KTS OVER AT LEAST THE E HALF OF THE LAKE ON SUN INTO MON AS A LO
PRES TRACKS E THRU THE NORTHERN PLAINS AND THE PRES GRADIENT
TIGHTENS OVER THE UPPER LAKES. AS ANOTHER LO PRES DEVELOPS TO THE S
ON TUE...THE FLOW WILL TEND TO BACK TOWARD THE NW. THE LATEST TRENDS
INDICATE THIS LO WILL DEEPEN SIGNFICANTLY AS IT MOVES TO THE NNE
THRU THE CENTRAL GREAT LAKES ON WED AND INTO SE ONTARIO ON XMAS DAY.
THE POTENTIAL FOR A N VEERING NW GALE EVENT FROM LATE ON WED THRU
XMAS DAY NOW LOOKS GREATER.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...KC
AVIATION...KF
MARINE...KC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
339 PM CST SAT DEC 20 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 336 PM CST SAT DEC 20 2014
SATELLITE SHOWS THE AREA OF PERSISTENT STRATUS IN THE EASTERN PART
OF THE FORECAST AREA HAS MOVED LITTLE IN THE PAST COUPLE HOURS BUT
THE THE HIGH CLOUDS MOVING OVER FROM THE WEST THE STRATUS IS
BECOMING MORE DIFFICULT TO SEE. IN THE STRATUS TEMPERATURES CONTINUE
TO STRUGGLE IN THE 30S...BUT AREAS WITH SUNSHINE HAVE WARMED MORE
THIS AFTERNOON.
MAIN CONCERN WITH THIS PERIOD ONCE AGAIN IS THE FOG CHANCES FOR
TONIGHT. A WEAK UPPER LEVEL WAVE MOVES THROUGH THE FORECAST AREA
LATE TONIGHT INTO SUNDAY. WITH THIS EXPECT THERE TO BE SOME HIGHER
CLOUDS THAT MOVE INTO THE AREA...BUT DRY CONDITIONS ARE EXPECTED.
THE LOW LEVEL MOISTURE CONTINUES ACROSS MUCH OF THE AREA THROUGH THE
NIGHT AND INTO SUNDAY. THE STRATUS SEEMS TO BE THE MOST PERSISTENT
IN THE NORTHEAST PART OF THE FORECAST AREA. THE RAP RELATIVE
HUMIDITY AT 925MB HAS BEEN FOLLOWING THE STRATUS THE BEST THIS
AFTERNOON AND THROUGH MOST OF THE NIGHT THE NORTHEAST REMAINS WITH
CLOUDS. IN THE SOUTHEAST THE HIGHER RELATIVE HUMIDITY BUILDS BACK
INTO THE AREA LATE TONIGHT. EXPECT THERE COULD BE SOME FOG NEAR THE
EDGES OF THE STRATUS. WILL KEEP PATCHY FOG ACROSS ALL BUT THE FAR
WEST AND AREAS OF FOG IN THE EAST WHERE THERE IS THE BEST CHANCE FOR
FOG SINCE VISIBILITY AT KJYR STILL HAS LOW VISIBILITY. ONCE AGAIN
THERE IS A POTENTIAL FOR SOME LOWER VISIBILITIES LATE TONIGHT INTO
SUNDAY MORNING AND EXPECT THE EAST IS THE BEST CHANCE.
BY SUNDAY MORNING THE WINDS WILL INCREASE A LITTLE BIT FROM THE
SOUTH. THIS WILL HELP TO MIX THINGS UP A BIT AND THE FOG AND STRATUS
MAY FINALLY MOVE OUT OF THE AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 336 PM CST SAT DEC 20 2014
THE BIGGEST CHALLENGE WILL BE DETERMINING PRECIPITATION CHANCES.
WE KICK OFF THE LONG TERM SUNDAY NIGHT WITH A LONGWAVE TROUGH AXIS
OVER THE GREAT PLAINS...AS A STRONG JET HEADS IN ON THE BACKSIDE OF
THE TROUGH..FROM THE PACIFIC NORTHWEST INTO THE GREAT BASIN. MOST OF
THE ENERGY IS ASSOCIATED WITH THE CLOSED LOW IN THE NORTHERN
PLAINS...SO I AM NOT GOING ALL THAT HIGH WITH CHANCES HERE. A
SMALLER SHORTWAVE TROUGH WITHIN THE LONGWAVE TROUGH WILL HELP KICK
SOMETHING UP IN THE EVENING...THE WAY IT LOOKS NOW...BUT SMALL
FEATURES ARE DIFFICULT TO BE VERY EXACT WITH TIMING. KEEPING THIS
ALL RAIN AS TEMPERATURES DO NOT APPEAR TO BECOME COLD ENOUGH BEFORE
THE PRECIPITATION EXITS WITH THIS PERTURBATION. ANOTHER PERTURBATION
WORKS AROUND THE TROUGH BY MONDAY NIGHT/TUESDAY. TEMPERATURE
PROFILES APPEAR TO SUPPORT SOME LIGHT SNOW MONDAY NIGHT INTO
TUESDAY. PRECIPITATION/SNOW AMOUNTS ARE EXPECTED TO BE LIGHT...WITH
SNOW ACCUMULATION NO MORE THAN AN INCH ANTICIPATED WITH THIS NEXT
PIECE OF ENERGY. AGAIN...CONFIDENCE IS NOT THE HIGHEST WITH
EXACT TIMING.
FLOW IS QUITE PROGRESSIVE AND YET ANOTHER TROUGH MAKES ITS WAY INTO
THE ROCKIES. A PIECE OF ENERGY IS EXPECTED TO BREAK OFF AHEAD OF THE
MAIN WAVE...BUT LOOKS MORE FOCUSED JUST NORTH OF THE CWA. WE COULD
GET SOME SNOW OUT OF THIS...BUT AGAIN...DOES NOT LOOK LIKE WE WILL
GET A LOT OUT OF SNOW. WE SHOULD GET A NOTICEABLE COOL DOWN FRIDAY
BEHIND THE ASSOCIATED COLD FRONT. HIGHS WILL ONLY BE IN THE LOWER TO
MID 30S AND THE WIND COULD BE QUITE GUSTY FROM THE
NORTHWEST...MAKING THE DAY AFTER CHRISTMAS POTENTIALLY BRISK AND
UNCOMFORTABLE.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1127 AM CST SAT DEC 20 2014
FOG CONTINUES TO BE PERSISTENT IN THE KGRI TERMINAL AREA.
SATELLITE HAS NOT SHOWN ANY EASTWARD MOVEMENT OF THE CLOUDS AND
VISIBILITY HAS CONTINUED TO BE AT 1/4 MILE OR LESS. WILL KEEP WITH
PERSISTENCE FOR A COUPLE MORE HOURS THEN BELIEVE THAT THE
VISIBILITY WILL IMPROVE...BUT NOT ESCAPE THE LOW CLOUDS AND FOG.
IF IT DOES NOT MOVE OUT THIS AFTERNOON EXPECT THAT IT WILL RETURN
AS THE SUN GOES DOWN TONIGHT. KEAR TERMINAL HAS A LITTLE LIGHT FOG
THAT SHOULD IMPROVE THIS AFTERNOON AS WELL. THE HIGH CLOUDS MOVING
IN SHOULD KEEP THE FOG AND LOW CLOUDS OUT OF THE AREA.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...HEINLEIN
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS BISMARCK ND
201 PM CST SAT DEC 20 2014
.UPDATE...
ISSUED AT 201 PM CST SAT DEC 20 2014
QUICK UPDATE TO CANCEL THE DENSE FOG ADVISORY. MID LEVEL CLOUDS
AND A SOUTHWEST WIND HAVE LIFTED MOST AREAS OF FOG...WITH THE FAR
NORTHEAST EXPECTED TO IMPROVE OVER THE NEXT HOUR.
UPDATE
ISSUED AT 1239 PM CST SAT DEC 20 2014
TRIMMED OFF A FEW MORE COUNTIES FROM THE DENSE FOG ADVISORY AS THE
BAND OF MID LEVEL CLOUDS AND A TRANSITION TO A SOUTHWEST WIND SCOURS
OUT THE LOW LEVEL MOISTURE. WILL MAINTAIN MY EASTERN COUNTIES
THROUGH 20Z AND MONITOR IN CASE ANOTHER EXTENSION BECOMES NEEDED.
DO NOT ANTICIPATE DENSE FOG FOR TONIGHT. DID HAVE SOME VERY LIGHT
ZR HERE IN BISMARCK LESS THAN AN HOUR AGO...SO WILL MAINTAIN A
SLIGHT CHANCE POP WITH THE BAND OF RADAR RETURNS ORIENTATED ALONG
A NORTH TO SOUTH-SOUTHEAST FRONTAL BOUNDARY.
UPDATE
ISSUED AT 1044 AM CST SAT DEC 20 2014
REMOVED KIDDER COUNTY FROM THE DENSE FOG ADVISORY. REMAINDER OF
THE FORECAST REMAINS UNCHANGED.
UPDATE
ISSUED AT 1008 AM CST SAT DEC 20 2014
WILL EXTEND THE DENSE FOG ADVISORY FOR MY NORTH CENTRAL AND EAST
THROUGH 20Z. SEE NO SIGNS OF VISIBILITIES IMPROVING UNTIL THE MID
LEVEL CLOUD DECK PUSHES FARTHER EAST NOW THROUGH 20Z ALONG A
FRONTAL BOUNDARY. UNSURE IF ANYTHING IS REACHING THE GROUND WITH A
BAND OF THE RADAR ECHOS STRETCHING FROM CROSBY SOUTH-SOUTHEAST
THROUGH GRANT COUNTY. CALLED SEVERAL LOCATIONS AND THUS FAR NO
REPORTS. STILL WORTH A MENTION SINCE PRECIP TYPE WILL BE ZR/SLEET
UNTIL SURFACE TEMPERATURES WARM.
ALREADY CLEARING OVER MY WEST AND EXPECT THIS TREND TO CONTINUE
SOUTHWEST INTO SOUTH CENTRAL AS THE DAY PROGRESSES. CLOUDS
REDEVELOP NORTHWEST AS WRAP AROUND MOISTURE PIVOTS IN FROM
NORTHEASTERN MONTANA. MODIFIED SKY GRIDS FOR THIS...AND ALSO
TRENDED POPS DOWN LATER TODAY INTO TONIGHT.
UPDATE ISSUED AT 616 AM CST SAT DEC 20 2014
MID LEVEL CLOUD COVER ACROSS WESTERN NORTH DAKOTA HAS LEAD TO THE
SEEDING OF THE LOW LEVEL STRATUS ACROSS THE FAR NORTHWEST. THE
RESULT IS LIGHT FLURRIES AND GREATLY IMPROVED VISIBILITIES FROM
THE PREVIOUS DENSE FOG. THUS...LET THE DENSE FOG ADVISORY EXPIRE
ON TIME FOR DIVIDE AND WILLIAMS COUNTIES. ELSEWHERE...GIVEN
OBSERVED TRENDS AND THE 11 UTC HRRR VISIBILITY FORECAST...EXTENDED
THE REMAINDER OF THE ADVISORY THROUGH 16 UTC AND ADDED LAMOURE AND
DICKEY COUNTIES. GIVEN THE TRENDS IN THE HRRR...PORTIONS OF THE
ADVISORY ACROSS THE JAMES RIVER VALLEY MAY NEED TO BE EXTENDED
INTO THE AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CST SAT DEC 20 2014
MAIN CONCERNS IN THE SHORT TERM ARE THE PERSISTENT FOG IN THE NORTH
AND CENTRAL TODAY...AND PRECIPITATION CHANCES AND WEATHER TYPE FOR
TODAY AND TONIGHT.
CURRENTLY...WATER VAPOR SATELLITE LOOP INDICATES THE NEXT UPPER
LEVEL SHORTWAVE TO AFFECT THE STATE TODAY WAS OVER NORTH CENTRAL
MONTANA/SOUTHERN SASKATCHEWAN/ALBERTA. AT THE SURFACE...LOW PRESSURE
WAS CENTERED OVER THE SOUTHERN BORDER OF ALBERTA/SASKATCHEWAN WITH A
TROUGH EXTENDING SOUTHEAST ACROSS EASTERN MONTANA. WIDESPREAD FOG
WITH VISIBILITIES RANGING FROM 1/4 MILE TO 1 MILE EXTENDED ACROSS
NORTHWESTERN AND MUCH OF CENTRAL NORTH DAKOTA.
TODAY THE UPPER LEVEL LOW/TROUGH IS PROGGED TO ENTER WESTERN NORTH
DAKOTA THIS MORNING AND ENTER CENTRAL NORTH DAKOTA THIS
AFTERNOON...EXITING NORTH DAKOTA SUNDAY MORNING. AT THE
SURFACE...THE SURFACE LOW AND ATTENDANT WARM FRONT IS FORECAST TO
MOVE EAST TODAY. THE LOW SHOULD MOVE EAST ACROSS SOUTHERN
SASKATCHEWAN/MANITOBA...WITH THE WARM FRONT ENTERING WESTERN NORTH
DAKOTA THIS MORNING...AND CENTRAL NORTH DAKOTA THIS AFTERNOON.
REGARDING THE FOG...AS THE AFOREMENTIONED SYSTEM MOVES INTO WESTERN
NORTH DAKOTA VISIBILITIES SHOULD IMPROVE WITH SUFFICIENT LOW TO MID
LEVEL MIXING. THE HRRR VISIBILITY PROGS SUPPORT THIS AS WELL. AREAS
OF FOG SHOULD PERSIST IN CENTRAL NORTH DAKOTA INTO THE
AFTERNOON...IMPROVING VISIBILITIES WITH TIME FROM WEST TO EAST AS THE
LOW PRESSURE SYSTEM ADVANCES EASTWARD.
THE SHORTWAVE AND SURFACE WARM FRONT WILL ALSO BRING LIGHT SCATTERED
PRECIPITATION TODAY AND TONIGHT. LOOKING AT INCREASING CHANCES THIS
MORNING IN THE WEST...EXPANDING INTO CENTRAL NORTH DAKOTA THIS
AFTERNOON. WARM ADVECTION ALOFT WILL RESULT IN MIXED PRECIPITATION
OF FREEZING DRIZZLE OR DRIZZLE EARLY THIS MORNING WITH CHANCES OF
LIGHT RAIN/DRIZZLE THIS AFTERNOON IN THE WEST AS TEMPERATURES RISE
INTO THE 30S. FARTHER EAST FREEZING DRIZZLE OR LIGHT SNOW SHOULD BE
THE PREDOMINANT WEATHER TYPE.
TONIGHT THE MAIN ENERGY FROM THE UPPER LEVEL TROUGH SHOULD KEEP THE
CHANCE OF PRECIPITATION CONFINED TO THE NORTH CENTRAL AND JAMES
RIVER VALLEY AND EASTWARD. FREEZING DRIZZLE OR LIGHT SNOW WOULD BE
THE MAIN WEATHER TYPE THERE TONIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 330 AM CST SAT DEC 20 2014
A WINTRY MIX POSSIBLE SUNDAY EVENING INTO MONDAY NIGHT...FOLLOWED
BY SNOWFALL POTENTIAL EARLY NEXT WEEK IMPACTING CHRISTMAS TRAVEL
HIGHLIGHT THE EXTENDED FORECAST.
FOR THE 00 UTC GUIDANCE SUITE...WHILE IN AGREEMENT ON GENERAL
FEATURES THROUGH THE EXTENDED FORECAST...SPATIAL DIFFERENCES IN
THE MASS FIELDS AND TIMING RESULT IN NON-TRIVIAL IMPACTS TO
SENSIBLE WEATHER THROUGH THE PERIOD. OVERALL...WEIGHED HEAVILY ON
THE 00 UTC ECMWF AND 03 UTC SREF WHICH RESIDE IN THE MIDDLE OF THE
ENVELOPE OF SOLUTIONS. FOR SUNDAY...A LEAD SHORTWAVE EJECTING OUT
OF THE ROCKIES IS FORECAST TO RESULT IN A RAIN AND SNOW MIX
DEPENDING ON SURFACE TEMPERATURES ACROSS WESTERN NORTH DAKOTA IN
THE AFTERNOON.
THE CHALLENGE IS SUNDAY EVENING INTO MONDAY NIGHT IN REGARDS TO
PRECIPITATION TYPE ACROSS CENTRAL NORTH DAKOTA. A MELTING LAYER
ALOFT ABOVE SUB-FREEZING SURFACE TEMPERATURES IS FORECAST TO
EXIST. HOWEVER...DRY AIR IN THE 900-750 MB LAYER WILL HAVE TO BE
SATURATED FOR PRECIPITATION TO REACH THE GROUND. THUS ENTERS THE
UNCERTAINTY AS TO HOW MUCH OF THE MELTING LAYER WILL REMAIN POST-
SATURATION DUE TO THE WET-BULB EFFECT. THERE APPEARS TO BE A BRIEF
WINDOW...ESPECIALLY ACROSS SOUTH CENTRAL NORTH DAKOTA...FOR THE
WARM LAYER TO BE AROUND +2 TO +2.5 C AROUND 00-03 UTC FOR A WINTRY
MIX OF FREEZING RAIN...SLEET AND MELTED SNOW TO BE POSSIBLE.
OVERALL AMOUNTS WILL BE LIGHT WITH THE COLUMN QUICKLY COOLING TO
SUPPORT ALL SNOW BETWEEN 03-06 UTC. THEREAFTER...ATTENTION TURNS
TO CYCLOGENESIS ACROSS THE EASTERN DAKOTAS AND INTO THE UPPER
MISSISSIPPI VALLEY MONDAY. THE 00 UTC DETERMINISTIC AND ENSEMBLE
SOLUTIONS SHOW A VARIED UPPER LEVEL LOW POSITION FROM NORTH
DAKOTA ON THE NAM TO IOWA ON THE GFS...WITH THE SREF AND ECMWF IN
BETWEEN. THUS...WIDESPREAD LIGHT SNOW IS EXPECTED FOR THE AREA
MONDAY ON ALL SOLUTIONS...WITH HIGHER AMOUNTS IN BANDING POSSIBLE.
HOWEVER...UNCERTAINTY IN THESE BANDS IS RATHER HIGH UNTIL THE MASS
FIELDS COME INTO BETTER AGREEMENT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1239 PM CST SAT DEC 20 2014
LIFR CEILINGS/VISIBILITIES CONTINUE AT KJMS. KMOT HAS IMPROVED
FROM IFR TO NOW VFR. FARTHER WEST KBIS-KISN AND KDIK SHOULD
REMAIN VFR. STRATUS AND FOG SHOULD ERODE EAST AS AN APPROACHING
SYSTEM BRINGS A DRIER SOUTHWEST FLOW. KJMS NOT IMPROVING UNTIL
AROUND MID TO LATE AFTERNOON. THERE IS A RISK OF ISOLATED TO
SCATTERED MIXED PRECIPITATION AT CENTRAL AND EASTERN TAF SITES
THIS AFTERNOON. DID NOT MENTION IN TAFS AS LESS THAN 50 PERCENT
CHANCE AND ONLY TRACE LIQUID EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...JV
LONG TERM...AYD
AVIATION...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1239 PM CST SAT DEC 20 2014
.UPDATE...
ISSUED AT 1239 PM CST SAT DEC 20 2014
TRIMMED OFF A FEW MORE COUNTIES FROM THE DENSE FOG ADVISORY AS THE
BAND OF MID LEVEL CLOUDS AND A TRANSITION TO A SOUTHWEST WIND SCOURS
OUT THE LOW LEVEL MOISTURE. WILL MAINTAIN MY EASTERN COUNTIES
THROUGH 20Z AND MONITOR IN CASE ANOTHER EXTENSION BECOMES NEEDED.
DO NOT ANTICIPATE DENSE FOG FOR TONIGHT. DID HAVE SOME VERY LIGHT
ZR HERE IN BISMARCK LESS THAN AN HOUR AGO...SO WILL MAINTAIN A
SLIGHT CHANCE POP WITH THE BAND OF RADAR RETURNS ORIENTATED ALONG
A NORTH TO SOUTH-SOUTHEAST FRONTAL BOUNDARY.
UPDATE
ISSUED AT 1044 AM CST SAT DEC 20 2014
REMOVED KIDDER COUNTY FROM THE DENSE FOG ADVISORY. REMAINDER OF
THE FORECAST REMAINS UNCHANGED.
UPDATE
ISSUED AT 1008 AM CST SAT DEC 20 2014
WILL EXTEND THE DENSE FOG ADVISORY FOR MY NORTH CENTRAL AND EAST
THROUGH 20Z. SEE NO SIGNS OF VISIBILITIES IMPROVING UNTIL THE MID
LEVEL CLOUD DECK PUSHES FARTHER EAST NOW THROUGH 20Z ALONG A
FRONTAL BOUNDARY. UNSURE IF ANYTHING IS REACHING THE GROUND WITH A
BAND OF THE RADAR ECHOS STRETCHING FROM CROSBY SOUTH-SOUTHEAST
THROUGH GRANT COUNTY. CALLED SEVERAL LOCATIONS AND THUS FAR NO
REPORTS. STILL WORTH A MENTION SINCE PRECIP TYPE WILL BE ZR/SLEET
UNTIL SURFACE TEMPERATURES WARM.
ALREADY CLEARING OVER MY WEST AND EXPECT THIS TREND TO CONTINUE
SOUTHWEST INTO SOUTH CENTRAL AS THE DAY PROGRESSES. CLOUDS
REDEVELOP NORTHWEST AS WRAP AROUND MOISTURE PIVOTS IN FROM
NORTHEASTERN MONTANA. MODIFIED SKY GRIDS FOR THIS...AND ALSO
TRENDED POPS DOWN LATER TODAY INTO TONIGHT.
UPDATE ISSUED AT 616 AM CST SAT DEC 20 2014
MID LEVEL CLOUD COVER ACROSS WESTERN NORTH DAKOTA HAS LEAD TO THE
SEEDING OF THE LOW LEVEL STRATUS ACROSS THE FAR NORTHWEST. THE
RESULT IS LIGHT FLURRIES AND GREATLY IMPROVED VISIBILITIES FROM
THE PREVIOUS DENSE FOG. THUS...LET THE DENSE FOG ADVISORY EXPIRE
ON TIME FOR DIVIDE AND WILLIAMS COUNTIES. ELSEWHERE...GIVEN
OBSERVED TRENDS AND THE 11 UTC HRRR VISIBILITY FORECAST...EXTENDED
THE REMAINDER OF THE ADVISORY THROUGH 16 UTC AND ADDED LAMOURE AND
DICKEY COUNTIES. GIVEN THE TRENDS IN THE HRRR...PORTIONS OF THE
ADVISORY ACROSS THE JAMES RIVER VALLEY MAY NEED TO BE EXTENDED
INTO THE AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CST SAT DEC 20 2014
MAIN CONCERNS IN THE SHORT TERM ARE THE PERSISTENT FOG IN THE NORTH
AND CENTRAL TODAY...AND PRECIPITATION CHANCES AND WEATHER TYPE FOR
TODAY AND TONIGHT.
CURRENTLY...WATER VAPOR SATELLITE LOOP INDICATES THE NEXT UPPER
LEVEL SHORTWAVE TO AFFECT THE STATE TODAY WAS OVER NORTH CENTRAL
MONTANA/SOUTHERN SASKATCHEWAN/ALBERTA. AT THE SURFACE...LOW PRESSURE
WAS CENTERED OVER THE SOUTHERN BORDER OF ALBERTA/SASKATCHEWAN WITH A
TROUGH EXTENDING SOUTHEAST ACROSS EASTERN MONTANA. WIDESPREAD FOG
WITH VISIBILITIES RANGING FROM 1/4 MILE TO 1 MILE EXTENDED ACROSS
NORTHWESTERN AND MUCH OF CENTRAL NORTH DAKOTA.
TODAY THE UPPER LEVEL LOW/TROUGH IS PROGGED TO ENTER WESTERN NORTH
DAKOTA THIS MORNING AND ENTER CENTRAL NORTH DAKOTA THIS
AFTERNOON...EXITING NORTH DAKOTA SUNDAY MORNING. AT THE
SURFACE...THE SURFACE LOW AND ATTENDANT WARM FRONT IS FORECAST TO
MOVE EAST TODAY. THE LOW SHOULD MOVE EAST ACROSS SOUTHERN
SASKATCHEWAN/MANITOBA...WITH THE WARM FRONT ENTERING WESTERN NORTH
DAKOTA THIS MORNING...AND CENTRAL NORTH DAKOTA THIS AFTERNOON.
REGARDING THE FOG...AS THE AFOREMENTIONED SYSTEM MOVES INTO WESTERN
NORTH DAKOTA VISIBILITIES SHOULD IMPROVE WITH SUFFICIENT LOW TO MID
LEVEL MIXING. THE HRRR VISIBILITY PROGS SUPPORT THIS AS WELL. AREAS
OF FOG SHOULD PERSIST IN CENTRAL NORTH DAKOTA INTO THE
AFTERNOON...IMPROVING VISIBILITIES WITH TIME FROM WEST TO EAST AS THE
LOW PRESSURE SYSTEM ADVANCES EASTWARD.
THE SHORTWAVE AND SURFACE WARM FRONT WILL ALSO BRING LIGHT SCATTERED
PRECIPITATION TODAY AND TONIGHT. LOOKING AT INCREASING CHANCES THIS
MORNING IN THE WEST...EXPANDING INTO CENTRAL NORTH DAKOTA THIS
AFTERNOON. WARM ADVECTION ALOFT WILL RESULT IN MIXED PRECIPITATION
OF FREEZING DRIZZLE OR DRIZZLE EARLY THIS MORNING WITH CHANCES OF
LIGHT RAIN/DRIZZLE THIS AFTERNOON IN THE WEST AS TEMPERATURES RISE
INTO THE 30S. FARTHER EAST FREEZING DRIZZLE OR LIGHT SNOW SHOULD BE
THE PREDOMINANT WEATHER TYPE.
TONIGHT THE MAIN ENERGY FROM THE UPPER LEVEL TROUGH SHOULD KEEP THE
CHANCE OF PRECIPITATION CONFINED TO THE NORTH CENTRAL AND JAMES
RIVER VALLEY AND EASTWARD. FREEZING DRIZZLE OR LIGHT SNOW WOULD BE
THE MAIN WEATHER TYPE THERE TONIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 330 AM CST SAT DEC 20 2014
A WINTRY MIX POSSIBLE SUNDAY EVENING INTO MONDAY NIGHT...FOLLOWED
BY SNOWFALL POTENTIAL EARLY NEXT WEEK IMPACTING CHRISTMAS TRAVEL
HIGHLIGHT THE EXTENDED FORECAST.
FOR THE 00 UTC GUIDANCE SUITE...WHILE IN AGREEMENT ON GENERAL
FEATURES THROUGH THE EXTENDED FORECAST...SPATIAL DIFFERENCES IN
THE MASS FIELDS AND TIMING RESULT IN NON-TRIVIAL IMPACTS TO
SENSIBLE WEATHER THROUGH THE PERIOD. OVERALL...WEIGHED HEAVILY ON
THE 00 UTC ECMWF AND 03 UTC SREF WHICH RESIDE IN THE MIDDLE OF THE
ENVELOPE OF SOLUTIONS. FOR SUNDAY...A LEAD SHORTWAVE EJECTING OUT
OF THE ROCKIES IS FORECAST TO RESULT IN A RAIN AND SNOW MIX
DEPENDING ON SURFACE TEMPERATURES ACROSS WESTERN NORTH DAKOTA IN
THE AFTERNOON.
THE CHALLENGE IS SUNDAY EVENING INTO MONDAY NIGHT IN REGARDS TO
PRECIPITATION TYPE ACROSS CENTRAL NORTH DAKOTA. A MELTING LAYER
ALOFT ABOVE SUB-FREEZING SURFACE TEMPERATURES IS FORECAST TO
EXIST. HOWEVER...DRY AIR IN THE 900-750 MB LAYER WILL HAVE TO BE
SATURATED FOR PRECIPITATION TO REACH THE GROUND. THUS ENTERS THE
UNCERTAINTY AS TO HOW MUCH OF THE MELTING LAYER WILL REMAIN POST-
SATURATION DUE TO THE WET-BULB EFFECT. THERE APPEARS TO BE A BRIEF
WINDOW...ESPECIALLY ACROSS SOUTH CENTRAL NORTH DAKOTA...FOR THE
WARM LAYER TO BE AROUND +2 TO +2.5 C AROUND 00-03 UTC FOR A WINTRY
MIX OF FREEZING RAIN...SLEET AND MELTED SNOW TO BE POSSIBLE.
OVERALL AMOUNTS WILL BE LIGHT WITH THE COLUMN QUICKLY COOLING TO
SUPPORT ALL SNOW BETWEEN 03-06 UTC. THEREAFTER...ATTENTION TURNS
TO CYCLOGENESIS ACROSS THE EASTERN DAKOTAS AND INTO THE UPPER
MISSISSIPPI VALLEY MONDAY. THE 00 UTC DETERMINISTIC AND ENSEMBLE
SOLUTIONS SHOW A VARIED UPPER LEVEL LOW POSITION FROM NORTH
DAKOTA ON THE NAM TO IOWA ON THE GFS...WITH THE SREF AND ECMWF IN
BETWEEN. THUS...WIDESPREAD LIGHT SNOW IS EXPECTED FOR THE AREA
MONDAY ON ALL SOLUTIONS...WITH HIGHER AMOUNTS IN BANDING POSSIBLE.
HOWEVER...UNCERTAINTY IN THESE BANDS IS RATHER HIGH UNTIL THE MASS
FIELDS COME INTO BETTER AGREEMENT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1239 PM CST SAT DEC 20 2014
LIFR CEILINGS/VISIBILITIES CONTINUE AT KJMS. KMOT HAS IMPROVED
FROM IFR TO NOW VFR. FARTHER WEST KBIS-KISN AND KDIK SHOULD
REMAIN VFR. STRATUS AND FOG SHOULD ERODE EAST AS AN APPROACHING
SYSTEM BRINGS A DRIER SOUTHWEST FLOW. KJMS NOT IMPROVING UNTIL
AROUND MID TO LATE AFTERNOON. THERE IS A RISK OF ISOLATED TO
SCATTERED MIXED PRECIPITATION AT CENTRAL AND EASTERN TAF SITES
THIS AFTERNOON. DID NOT MENTION IN TAFS AS LESS THAN 50 PERCENT
CHANCE AND ONLY TRACE LIQUID EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR NDZ004-005-
012-013-023-025-037-048-051.
&&
$$
UPDATE...NH
SHORT TERM...JV
LONG TERM...AYD
AVIATION...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1044 AM CST SAT DEC 20 2014
.UPDATE...
ISSUED AT 1044 AM CST SAT DEC 20 2014
REMOVED KIDDER COUNTY FROM THE DENSE FOG ADVISORY. REMAINDER OF
THE FORECAST REMAINS UNCHANGED.
UPDATE
ISSUED AT 1008 AM CST SAT DEC 20 2014
WILL EXTEND THE DENSE FOG ADVISORY FOR MY NORTH CENTRAL AND EAST
THROUGH 20Z. SEE NO SIGNS OF VISIBILITIES IMPROVING UNTIL THE MID
LEVEL CLOUD DECK PUSHES FARTHER EAST NOW THROUGH 20Z ALONG A
FRONTAL BOUNDARY. UNSURE IF ANYTHING IS REACHING THE GROUND WITH A
BAND OF THE RADAR ECHOS STRETCHING FROM CROSBY SOUTH-SOUTHEAST
THROUGH GRANT COUNTY. CALLED SEVERAL LOCATIONS AND THUS FAR NO
REPORTS. STILL WORTH A MENTION SINCE PRECIP TYPE WILL BE ZR/SLEET
UNTIL SURFACE TEMPERATURES WARM.
ALREADY CLEARING OVER MY WEST AND EXPECT THIS TREND TO CONTINUE
SOUTHWEST INTO SOUTH CENTRAL AS THE DAY PROGRESSES. CLOUDS
REDEVELOP NORTHWEST AS WRAP AROUND MOISTURE PIVOTS IN FROM
NORTHEASTERN MONTANA. MODIFIED SKY GRIDS FOR THIS...AND ALSO
TRENDED POPS DOWN LATER TODAY INTO TONIGHT.
UPDATE ISSUED AT 616 AM CST SAT DEC 20 2014
MID LEVEL CLOUD COVER ACROSS WESTERN NORTH DAKOTA HAS LEAD TO THE
SEEDING OF THE LOW LEVEL STRATUS ACROSS THE FAR NORTHWEST. THE
RESULT IS LIGHT FLURRIES AND GREATLY IMPROVED VISIBILITIES FROM
THE PREVIOUS DENSE FOG. THUS...LET THE DENSE FOG ADVISORY EXPIRE
ON TIME FOR DIVIDE AND WILLIAMS COUNTIES. ELSEWHERE...GIVEN
OBSERVED TRENDS AND THE 11 UTC HRRR VISIBILITY FORECAST...EXTENDED
THE REMAINDER OF THE ADVISORY THROUGH 16 UTC AND ADDED LAMOURE AND
DICKEY COUNTIES. GIVEN THE TRENDS IN THE HRRR...PORTIONS OF THE
ADVISORY ACROSS THE JAMES RIVER VALLEY MAY NEED TO BE EXTENDED
INTO THE AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CST SAT DEC 20 2014
MAIN CONCERNS IN THE SHORT TERM ARE THE PERSISTENT FOG IN THE NORTH
AND CENTRAL TODAY...AND PRECIPITATION CHANCES AND WEATHER TYPE FOR
TODAY AND TONIGHT.
CURRENTLY...WATER VAPOR SATELLITE LOOP INDICATES THE NEXT UPPER
LEVEL SHORTWAVE TO AFFECT THE STATE TODAY WAS OVER NORTH CENTRAL
MONTANA/SOUTHERN SASKATCHEWAN/ALBERTA. AT THE SURFACE...LOW PRESSURE
WAS CENTERED OVER THE SOUTHERN BORDER OF ALBERTA/SASKATCHEWAN WITH A
TROUGH EXTENDING SOUTHEAST ACROSS EASTERN MONTANA. WIDESPREAD FOG
WITH VISIBILITIES RANGING FROM 1/4 MILE TO 1 MILE EXTENDED ACROSS
NORTHWESTERN AND MUCH OF CENTRAL NORTH DAKOTA.
TODAY THE UPPER LEVEL LOW/TROUGH IS PROGGED TO ENTER WESTERN NORTH
DAKOTA THIS MORNING AND ENTER CENTRAL NORTH DAKOTA THIS
AFTERNOON...EXITING NORTH DAKOTA SUNDAY MORNING. AT THE
SURFACE...THE SURFACE LOW AND ATTENDANT WARM FRONT IS FORECAST TO
MOVE EAST TODAY. THE LOW SHOULD MOVE EAST ACROSS SOUTHERN
SASKATCHEWAN/MANITOBA...WITH THE WARM FRONT ENTERING WESTERN NORTH
DAKOTA THIS MORNING...AND CENTRAL NORTH DAKOTA THIS AFTERNOON.
REGARDING THE FOG...AS THE AFOREMENTIONED SYSTEM MOVES INTO WESTERN
NORTH DAKOTA VISIBILITIES SHOULD IMPROVE WITH SUFFICIENT LOW TO MID
LEVEL MIXING. THE HRRR VISIBILITY PROGS SUPPORT THIS AS WELL. AREAS
OF FOG SHOULD PERSIST IN CENTRAL NORTH DAKOTA INTO THE
AFTERNOON...IMPROVING VISIBILITIES WITH TIME FROM WEST TO EAST AS THE
LOW PRESSURE SYSTEM ADVANCES EASTWARD.
THE SHORTWAVE AND SURFACE WARM FRONT WILL ALSO BRING LIGHT SCATTERED
PRECIPITATION TODAY AND TONIGHT. LOOKING AT INCREASING CHANCES THIS
MORNING IN THE WEST...EXPANDING INTO CENTRAL NORTH DAKOTA THIS
AFTERNOON. WARM ADVECTION ALOFT WILL RESULT IN MIXED PRECIPITATION
OF FREEZING DRIZZLE OR DRIZZLE EARLY THIS MORNING WITH CHANCES OF
LIGHT RAIN/DRIZZLE THIS AFTERNOON IN THE WEST AS TEMPERATURES RISE
INTO THE 30S. FARTHER EAST FREEZING DRIZZLE OR LIGHT SNOW SHOULD BE
THE PREDOMINANT WEATHER TYPE.
TONIGHT THE MAIN ENERGY FROM THE UPPER LEVEL TROUGH SHOULD KEEP THE
CHANCE OF PRECIPITATION CONFINED TO THE NORTH CENTRAL AND JAMES
RIVER VALLEY AND EASTWARD. FREEZING DRIZZLE OR LIGHT SNOW WOULD BE
THE MAIN WEATHER TYPE THERE TONIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 330 AM CST SAT DEC 20 2014
A WINTRY MIX POSSIBLE SUNDAY EVENING INTO MONDAY NIGHT...FOLLOWED
BY SNOWFALL POTENTIAL EARLY NEXT WEEK IMPACTING CHRISTMAS TRAVEL
HIGHLIGHT THE EXTENDED FORECAST.
FOR THE 00 UTC GUIDANCE SUITE...WHILE IN AGREEMENT ON GENERAL
FEATURES THROUGH THE EXTENDED FORECAST...SPATIAL DIFFERENCES IN
THE MASS FIELDS AND TIMING RESULT IN NON-TRIVIAL IMPACTS TO
SENSIBLE WEATHER THROUGH THE PERIOD. OVERALL...WEIGHED HEAVILY ON
THE 00 UTC ECMWF AND 03 UTC SREF WHICH RESIDE IN THE MIDDLE OF THE
ENVELOPE OF SOLUTIONS. FOR SUNDAY...A LEAD SHORTWAVE EJECTING OUT
OF THE ROCKIES IS FORECAST TO RESULT IN A RAIN AND SNOW MIX
DEPENDING ON SURFACE TEMPERATURES ACROSS WESTERN NORTH DAKOTA IN
THE AFTERNOON.
THE CHALLENGE IS SUNDAY EVENING INTO MONDAY NIGHT IN REGARDS TO
PRECIPITATION TYPE ACROSS CENTRAL NORTH DAKOTA. A MELTING LAYER
ALOFT ABOVE SUB-FREEZING SURFACE TEMPERATURES IS FORECAST TO
EXIST. HOWEVER...DRY AIR IN THE 900-750 MB LAYER WILL HAVE TO BE
SATURATED FOR PRECIPITATION TO REACH THE GROUND. THUS ENTERS THE
UNCERTAINTY AS TO HOW MUCH OF THE MELTING LAYER WILL REMAIN POST-
SATURATION DUE TO THE WET-BULB EFFECT. THERE APPEARS TO BE A BRIEF
WINDOW...ESPECIALLY ACROSS SOUTH CENTRAL NORTH DAKOTA...FOR THE
WARM LAYER TO BE AROUND +2 TO +2.5 C AROUND 00-03 UTC FOR A WINTRY
MIX OF FREEZING RAIN...SLEET AND MELTED SNOW TO BE POSSIBLE.
OVERALL AMOUNTS WILL BE LIGHT WITH THE COLUMN QUICKLY COOLING TO
SUPPORT ALL SNOW BETWEEN 03-06 UTC. THEREAFTER...ATTENTION TURNS
TO CYCLOGENESIS ACROSS THE EASTERN DAKOTAS AND INTO THE UPPER
MISSISSIPPI VALLEY MONDAY. THE 00 UTC DETERMINISTIC AND ENSEMBLE
SOLUTIONS SHOW A VARIED UPPER LEVEL LOW POSITION FROM NORTH
DAKOTA ON THE NAM TO IOWA ON THE GFS...WITH THE SREF AND ECMWF IN
BETWEEN. THUS...WIDESPREAD LIGHT SNOW IS EXPECTED FOR THE AREA
MONDAY ON ALL SOLUTIONS...WITH HIGHER AMOUNTS IN BANDING POSSIBLE.
HOWEVER...UNCERTAINTY IN THESE BANDS IS RATHER HIGH UNTIL THE MASS
FIELDS COME INTO BETTER AGREEMENT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 1008 AM CST SAT DEC 20 2014
LIFR CEILINGS/VISIBILITIES CONTINUE AT KMOT AND KJMS. KBIS HAS
IMPROVED FROM IFR TO NOW VFR. FARTHER WEST KISN AND KDIK SHOULD
REMAIN VFR. STRATUS AND FOG SHOULD ERODE FROM WEST TO EAST AS AN
APPROACHING SYSTEM BRINGS A DRIER SOUTHWEST FLOW. KMOT SHOULD
BECOME VFR BEFORE/BY 18-19Z. KJMS NOT IMPROVING UNTIL AROUND MID
TO LATE AFTERNOON. THERE IS A RISK OF ISOLATED TO SCATTERED MIXED
PRECIPITATION AT ALL TAF SITES THIS MORNING AND AFTERNOON. DID NOT
MENTION IN TAFS AS LESS THAN 50 PERCENT CHANCE AND ONLY TRACE
LIQUID EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR NDZ002>005-
011>013-022-023-025-037-048-051.
&&
$$
UPDATE...NH
SHORT TERM...JV
LONG TERM...AYD
AVIATION...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1008 AM CST SAT DEC 20 2014
.UPDATE...
ISSUED AT 1008 AM CST SAT DEC 20 2014
WILL EXTEND THE DENSE FOG ADVISORY FOR MY NORTH CENTRAL AND EAST
THROUGH 20Z. SEE NO SIGNS OF VISIBILITIES IMPROVING UNTIL THE MID
LEVEL CLOUD DECK PUSHES FARTHER EAST NOW THROUGH 20Z ALONG A
FRONTAL BOUNDARY. UNSURE IF ANYTHING IS REACHING THE GROUND WITH A
BAND OF THE RADAR ECHOS STRETCHING FROM CROSBY SOUTH-SOUTHEAST
THROUGH GRANT COUNTY. CALLED SEVERAL LOCATIONS AND THUS FAR NO
REPORTS. STILL WORTH A MENTION SINCE PRECIP TYPE WILL BE ZR/SLEET
UNTIL SURFACE TEMPERATURES WARM.
ALREADY CLEARING OVER MY WEST AND EXPECT THIS TREND TO CONTINUE
SOUTHWEST INTO SOUTH CENTRAL AS THE DAY PROGRESSES. CLOUDS
REDEVELOP NORTHWEST AS WRAP AROUND MOISTURE PIVOTS IN FROM
NORTHEASTERN MONTANA. MODIFIED SKY GRIDS FOR THIS...AND ALSO
TRENDED POPS DOWN LATER TODAY INTO TONIGHT.
UPDATE ISSUED AT 616 AM CST SAT DEC 20 2014
MID LEVEL CLOUD COVER ACROSS WESTERN NORTH DAKOTA HAS LEAD TO THE
SEEDING OF THE LOW LEVEL STRATUS ACROSS THE FAR NORTHWEST. THE
RESULT IS LIGHT FLURRIES AND GREATLY IMPROVED VISIBILITIES FROM
THE PREVIOUS DENSE FOG. THUS...LET THE DENSE FOG ADVISORY EXPIRE
ON TIME FOR DIVIDE AND WILLIAMS COUNTIES. ELSEWHERE...GIVEN
OBSERVED TRENDS AND THE 11 UTC HRRR VISIBILITY FORECAST...EXTENDED
THE REMAINDER OF THE ADVISORY THROUGH 16 UTC AND ADDED LAMOURE AND
DICKEY COUNTIES. GIVEN THE TRENDS IN THE HRRR...PORTIONS OF THE
ADVISORY ACROSS THE JAMES RIVER VALLEY MAY NEED TO BE EXTENDED
INTO THE AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CST SAT DEC 20 2014
MAIN CONCERNS IN THE SHORT TERM ARE THE PERSISTENT FOG IN THE NORTH
AND CENTRAL TODAY...AND PRECIPITATION CHANCES AND WEATHER TYPE FOR
TODAY AND TONIGHT.
CURRENTLY...WATER VAPOR SATELLITE LOOP INDICATES THE NEXT UPPER
LEVEL SHORTWAVE TO AFFECT THE STATE TODAY WAS OVER NORTH CENTRAL
MONTANA/SOUTHERN SASKATCHEWAN/ALBERTA. AT THE SURFACE...LOW PRESSURE
WAS CENTERED OVER THE SOUTHERN BORDER OF ALBERTA/SASKATCHEWAN WITH A
TROUGH EXTENDING SOUTHEAST ACROSS EASTERN MONTANA. WIDESPREAD FOG
WITH VISIBILITIES RANGING FROM 1/4 MILE TO 1 MILE EXTENDED ACROSS
NORTHWESTERN AND MUCH OF CENTRAL NORTH DAKOTA.
TODAY THE UPPER LEVEL LOW/TROUGH IS PROGGED TO ENTER WESTERN NORTH
DAKOTA THIS MORNING AND ENTER CENTRAL NORTH DAKOTA THIS
AFTERNOON...EXITING NORTH DAKOTA SUNDAY MORNING. AT THE
SURFACE...THE SURFACE LOW AND ATTENDANT WARM FRONT IS FORECAST TO
MOVE EAST TODAY. THE LOW SHOULD MOVE EAST ACROSS SOUTHERN
SASKATCHEWAN/MANITOBA...WITH THE WARM FRONT ENTERING WESTERN NORTH
DAKOTA THIS MORNING...AND CENTRAL NORTH DAKOTA THIS AFTERNOON.
REGARDING THE FOG...AS THE AFOREMENTIONED SYSTEM MOVES INTO WESTERN
NORTH DAKOTA VISIBILITIES SHOULD IMPROVE WITH SUFFICIENT LOW TO MID
LEVEL MIXING. THE HRRR VISIBILITY PROGS SUPPORT THIS AS WELL. AREAS
OF FOG SHOULD PERSIST IN CENTRAL NORTH DAKOTA INTO THE
AFTERNOON...IMPROVING VISIBILITIES WITH TIME FROM WEST TO EAST AS THE
LOW PRESSURE SYSTEM ADVANCES EASTWARD.
THE SHORTWAVE AND SURFACE WARM FRONT WILL ALSO BRING LIGHT SCATTERED
PRECIPITATION TODAY AND TONIGHT. LOOKING AT INCREASING CHANCES THIS
MORNING IN THE WEST...EXPANDING INTO CENTRAL NORTH DAKOTA THIS
AFTERNOON. WARM ADVECTION ALOFT WILL RESULT IN MIXED PRECIPITATION
OF FREEZING DRIZZLE OR DRIZZLE EARLY THIS MORNING WITH CHANCES OF
LIGHT RAIN/DRIZZLE THIS AFTERNOON IN THE WEST AS TEMPERATURES RISE
INTO THE 30S. FARTHER EAST FREEZING DRIZZLE OR LIGHT SNOW SHOULD BE
THE PREDOMINANT WEATHER TYPE.
TONIGHT THE MAIN ENERGY FROM THE UPPER LEVEL TROUGH SHOULD KEEP THE
CHANCE OF PRECIPITATION CONFINED TO THE NORTH CENTRAL AND JAMES
RIVER VALLEY AND EASTWARD. FREEZING DRIZZLE OR LIGHT SNOW WOULD BE
THE MAIN WEATHER TYPE THERE TONIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 330 AM CST SAT DEC 20 2014
A WINTRY MIX POSSIBLE SUNDAY EVENING INTO MONDAY NIGHT...FOLLOWED
BY SNOWFALL POTENTIAL EARLY NEXT WEEK IMPACTING CHRISTMAS TRAVEL
HIGHLIGHT THE EXTENDED FORECAST.
FOR THE 00 UTC GUIDANCE SUITE...WHILE IN AGREEMENT ON GENERAL
FEATURES THROUGH THE EXTENDED FORECAST...SPATIAL DIFFERENCES IN
THE MASS FIELDS AND TIMING RESULT IN NON-TRIVIAL IMPACTS TO
SENSIBLE WEATHER THROUGH THE PERIOD. OVERALL...WEIGHED HEAVILY ON
THE 00 UTC ECMWF AND 03 UTC SREF WHICH RESIDE IN THE MIDDLE OF THE
ENVELOPE OF SOLUTIONS. FOR SUNDAY...A LEAD SHORTWAVE EJECTING OUT
OF THE ROCKIES IS FORECAST TO RESULT IN A RAIN AND SNOW MIX
DEPENDING ON SURFACE TEMPERATURES ACROSS WESTERN NORTH DAKOTA IN
THE AFTERNOON.
THE CHALLENGE IS SUNDAY EVENING INTO MONDAY NIGHT IN REGARDS TO
PRECIPITATION TYPE ACROSS CENTRAL NORTH DAKOTA. A MELTING LAYER
ALOFT ABOVE SUB-FREEZING SURFACE TEMPERATURES IS FORECAST TO
EXIST. HOWEVER...DRY AIR IN THE 900-750 MB LAYER WILL HAVE TO BE
SATURATED FOR PRECIPITATION TO REACH THE GROUND. THUS ENTERS THE
UNCERTAINTY AS TO HOW MUCH OF THE MELTING LAYER WILL REMAIN POST-
SATURATION DUE TO THE WET-BULB EFFECT. THERE APPEARS TO BE A BRIEF
WINDOW...ESPECIALLY ACROSS SOUTH CENTRAL NORTH DAKOTA...FOR THE
WARM LAYER TO BE AROUND +2 TO +2.5 C AROUND 00-03 UTC FOR A WINTRY
MIX OF FREEZING RAIN...SLEET AND MELTED SNOW TO BE POSSIBLE.
OVERALL AMOUNTS WILL BE LIGHT WITH THE COLUMN QUICKLY COOLING TO
SUPPORT ALL SNOW BETWEEN 03-06 UTC. THEREAFTER...ATTENTION TURNS
TO CYCLOGENESIS ACROSS THE EASTERN DAKOTAS AND INTO THE UPPER
MISSISSIPPI VALLEY MONDAY. THE 00 UTC DETERMINISTIC AND ENSEMBLE
SOLUTIONS SHOW A VARIED UPPER LEVEL LOW POSITION FROM NORTH
DAKOTA ON THE NAM TO IOWA ON THE GFS...WITH THE SREF AND ECMWF IN
BETWEEN. THUS...WIDESPREAD LIGHT SNOW IS EXPECTED FOR THE AREA
MONDAY ON ALL SOLUTIONS...WITH HIGHER AMOUNTS IN BANDING POSSIBLE.
HOWEVER...UNCERTAINTY IN THESE BANDS IS RATHER HIGH UNTIL THE MASS
FIELDS COME INTO BETTER AGREEMENT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 1008 AM CST SAT DEC 20 2014
LIFR CEILINGS/VISIBILITIES CONTINUE AT KMOT AND KJMS. KBIS HAS
IMPROVED FROM IFR TO NOW VFR. FARTHER WEST KISN AND KDIK SHOULD
REMAIN VFR. STRATUS AND FOG SHOULD ERODE FROM WEST TO EAST AS AN
APPROACHING SYSTEM BRINGS A DRIER SOUTHWEST FLOW. KMOT SHOULD
BECOME VFR BEFORE/BY 18-19Z. KJMS NOT IMPROVING UNTIL AROUND MID
TO LATE AFTERNOON. THERE IS A RISK OF ISOLATED TO SCATTERED MIXED
PRECIPITATION AT ALL TAF SITES THIS MORNING AND AFTERNOON. DID NOT
MENTION IN TAFS AS LESS THAN 50 PERCENT CHANCE AND ONLY TRACE
LIQUID EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR NDZ002>005-
011>013-022-023-025-036-037-048-051.
&&
$$
UPDATE...NH
SHORT TERM...JV
LONG TERM...AYD
AVIATION...JV
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
324 PM CST SAT DEC 20 2014
.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
LOW CLOUDS AND FOG WILL ONCE AGAIN BE THE RULE OVERNIGHT AS A VERY
MOIST LOW LEVEL AIR MASS REMAINS IN PLACE. BEEN CLOSELY FOLLOWING
THE HRRR LOW-LEVEL CLOUD COVER PRODUCT WHICH HAS BEEN DOING AN
AMAZING JOB WITH HANDLING STRATUS DECKS THE PAST SEVERAL EVENTS.
IT BASICALLY SHOWS THE STRATUS CLOUDS REMAINING IN PLACE ALL NIGHT
WITH A SLIGHT WESTWARD PUSH ONCE AGAIN ON ITS WESTERN EDGE. WILL
GO WITH PERSISTENCE FORECAST CONCERNING THE FOG AS IT HAS BEEN
OCCURRING THE PAST FEW NIGHTS UNDERNEATH THE STRATUS...SO NO
REASON WHY IT WONT HAPPEN AGAIN...AND IN FACT WIDESPREAD LIGHT FOG
IS ALREADY IN PLACE...WITH LOCALLY THICKER FOG. SEEMS THE MOIST
LAYER IS TOO SHALLOW FOR ANY MEANINGFUL FREEZING DRIZZLE TO OCCUR
OVERNIGHT BUT SOMETHING TO KEEP AN EYE ON ANYWAY.
ON SUNDAY...EXPECTING LOW CLOUDS TO HANG IN TOUGH ACROSS THE EAST
ONCE AGAIN WITH NO REAL SIGNALS FROM ANYTHING TO CLEAR THEM OUT.
WILL ALSO BE WATCHING ARRIVAL OF THE LOW PRESSURE SYSTEM WHICH
WILL ENTER THE DAKOTAS BY SUNDAY EVENING...THEN MOVE INTO WESTERN
MINNESOTA AND IOWA REGION BY MONDAY NIGHT. MODELS STILL HAVING A
TOUGH TIME HANDLING THIS SYSTEM IN REGARDS TO STRENGTH MAINLY.
THEY REALLY DO NOT KNOW HOW TO HANDLE THE EVENTUAL CLOSING OFF AND
SUBSEQUENT MOVEMENT OF THE UPPER LOW...AND ITS ASSOCIATED MOISTURE
AVAILABILITY. THIS WILL BE KEY IN FIGURING OUT JUST HOW MUCH WRAP
AROUND PRECIPITATION WE RECEIVE. BASICALLY TOOK A BLENDED APPROACH
FOR RIGHT NOW WHICH STILL LEAVES THE AREA WITH A COUPLE INCHES OF
SNOW AND SOME MIXED PRECIP IN THE FORM OF FREEZING RAIN AND SLEET
TO START THINGS OFF SUNDAY EVENING. THERMAL PROFILES EVENTUALLY
GET COLD ENOUGH BY MONDAY TO CHANGE THINGS OVER TO SNOW. STILL
HAVE MANY DOUBTS AND LOW CONFIDENCE IN EXACTLY JUST HOW THIS
SYSTEM WILL EVOLVE AND HOW MUCH MOISTURE WILL REALLY BE ASSOCIATED
WITH IT. HAVE A FEELING MODELS MAY NOT LATCH ON TO A MORE
DEFINITIVE SOLUTION UNTIL SOMETIME SUNDAY.
.LONG TERM...TUESDAY THROUGH SATURDAY
LOW PRESSURE WILL BE EAST OF THE REGION WHEN THE PERIOD STARTS
WITH THE POTENTIAL FOR LINGERING SNOW SHOWERS...MAINLY ACROSS THE
EASTERN PART OF THE CWA THROUGH THE DAY TUESDAY. A DECENT PRESSURE
GRADIENT ACROSS THE AREA MAY RESULT IN BREEZY TO WINDY CONDITIONS
AS WELL. WEAK HIGH PRESSURE THEN MOVES IN WITH DRY CONDITIONS
EXPECTED WEDNESDAY. ANOTHER LOW PRESSURE SYSTEM LOOKS TO TRACK
ACROSS THE CENTRAL PLAINS ON THURSDAY...BUT THE MODELS ARE NOT IN
VERY GOOD AGREEMENT WITH STRENGTH OR TIMING. THE GFS AND ECMWF
AGREE SOMEWHAT ON THE TIMING WITH THE GEM BEING MUCH SLOWER.
HOWEVER...THE GFS BRINGS LITTLE IN THE WAY OF
PRECIPITATION...WHILE THE ECMWF PLASTERS MOST OF THE STATE, FOR
NOW...WILL STICK FAIRLY CLOSE TO THE SUPERBLEND KEEPING SCHC/CHC
POPS MAINLY ACROSS THE SOUTHERN CWA THURSDAY INTO THE DAY FRIDAY.
HIGH PRESSURE WILL MOVE BACK IN AFTER THAT WITH DRY CONDITIONS
FRIDAY NIGHT THROUGH THE DAY SATURDAY.
SLIGHTLY ABOVE NORMAL TEMPERATURES WILL BE THE RULE FOR THE FIRST
HALF OF THE PERIOD...WITH HIGHS MAINLY IN THE MID 20S TO LOWER 30S
TUESDAY...WEDNESDAY AND THURSDAY. COOLER AIR THEN MOVES IN BEHIND
THE STORM SYSTEM...WITH HIGHS IN THE TEENS AND 20S FRIDAY AND
SATURDAY.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
IFR CIGS WILL REMAIN FIRMLY IN PLACE ACROSS THE EASTERN HALF OF
THE CWA THROUGH THE TAF PERIOD. UNDER THE LOW CLOUDS...VSBYS WILL
GENERALLY BE MVFR IN FOG THIS AFTERNOON...BUT THERE WILL LIKELY BE
PERIODS OF IFR VSBYS AGAIN OVERNIGHT AND INTO EARLY SUNDAY
MORNING...AFFECTING KABR AND KATY. VFR CONDITIONS WILL PREVAIL
ACROSS THE WESTERN HALF OF THE CWA WITH JUST SOME HIGH CLOUDS
STREAMING OVERHEAD.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TMT
LONG TERM...PARKIN
AVIATION...PARKIN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
222 PM CST SAT DEC 20 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 221 PM CST SAT DEC 20 2014
MUCH OF THE SAME EXPECTED TONIGHT INTO TOMORROW WITH THE LOW
CLOUDS HANGING TOUGH OVER A MAJORITY OF THE AREA. DO NOT REALLY
EXPECT THE CLEARING LINE TO MOVE MUCH THROUGH TOMORROW...WITH ONLY
GREGORY...BRULE AND PORTIONS OF CHARLES MIX COUNTIES SEEING ANY
CLEARING AND SUN. SIGNAL THAT THE DENSER FOG MAY ENCOMPASS MORE OF
THE AREA TONIGHT...MAKING IT TO AROUND THE INTERSTATE 29 CORRIDOR.
SO WILL HAVE TO KEEP AN EYE ON THIS...FOR NOW INCREASED MENTION OF
FOG IN THE GRIDS. GFS AND RAP SUGGEST LOW LEVEL MOISTURE DEPTH WILL
INCREASE TONIGHT AHEAD OF A WEAK UPPER WAVE THAT CROSSES THE REGION.
THIS HAPPENS MAINLY ACROSS PORTIONS OF NORTHWEST IOWA FROM SIOUX
CITY TO SPENCER. SO COULD POTENTIALLY SEE SOME PATCHY DRIZZLE OR
FREEZING DRIZZLE IN THAT AREA...BUT ANYTHING SHOULD BE LIGHT.
GIVEN THE CLOUD COVER...DIURNAL RANGE OF TEMPERATURES WILL BE SMALL.
WILL NOT FALL MUCH TONIGHT...WITH UPPER 20S TO LOW 30S EXPECTED.
THEN ON SUNDAY WE WILL ONLY WARM UP SEVERAL DEGREES...WITH 30S
ACROSS MOST OF THE REGION. WILL START TO BECOME A BIT BREEZY OUT OF
THE SOUTH BY LATER SUNDAY...WITH GUSTS AROUND 25 MPH EAST OF THE
JAMES RIVER.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 221 PM CST SAT DEC 20 2014
PRECIPITATION LIKELY TO DEVELOP ON SUNDAY...WITH THE BETTER CHANCES
IN THE EASTERN CWA. WHILE THE MAIN WARM FRONT IS TO THE NORTH OF THE
AREA...THE PV ANOMOLY AND COLD FRONT ALOFT SWING THROUGH SUNDAY
NIGHT AND SHOULD ALLOW WHAT WILL BE MAINLY RAIN. THE NORTHERN AND
WESTERN CWA COULD SEE SOME MIXED PRECIPITATION BUT THE CHANCES FOR
PRECIPITATION A LITTLE LOWER IN THESE LOCATIONS SO HOPEFULLY LITTLE
OR NO ACCUMULATION. TEMPERATURES REMAIN PRETTY MILD THROUGH THE
NIGHT AS WELL WITH LOW PRESSURE WRAPPING UP TO THE NORTH AND WEST OF
THE AREA SO MAINLY SOUTHERLY OR WESTERLY FLOW. LOWS GENERALLY FROM
THE LOWER TO MIDDLE 30S.
LOOKS LIKE EVERYONE SHOULD WARM TO AT LEAST THE MID 30S ON MONDAY
WITH LOWER 40S LIKELY IN PARTS OF NORTHWEST IOWA. THE DAYTIME
CHANCES FOR PRECIPITATION SHOULD NOT BE REAL HIGH AND WILL KEEP MOST
LOCATIONS IN THE CHANCE CATEGORY AS THE AREA WAITS FOR THE WRAP
AROUND TO SET UP LATE MONDAY AFTERNOON INTO MONDAY NIGHT. RIGHT NOW
LOOKING LIKE MAINLY A RAIN TO SNOW TRANSITION WITH LITTLE CHANCE FOR
SLEET AND FREEZING RAIN MONDAY AND MONDAY NIGHT.
THE CHANCE FOR SNOW WILL LINGER INTO TUESDAY BUT AMOUNTS WILL REMAIN
FAIRLY MINIMAL. WHEN ALL IS SAID AND DONE LOOKING AT ABOUT A HALF AN
INCH TO AN INCH OVER NORTHWEST IOWA TO 2 TO 3 INCHES FROM HURON TO
MARSHALL. A WAVE TRACKS THROUGH TO THE NORTH OF THE AREA ON TUESDAY
WHICH WILL BRING SOME DRYING ALOFT AND BRING AN END TO THE THREAT
FOR PRECIPITATION TUESDAY NIGHT INTO WEDNESDAY.
THE UPPER LEVEL PATTERN REMAINS FAIRLY ACTIVE THROUGH THE EXTENDED
PERIOD WITH ONE WAVE EXITING ON WEDNESDAY AND ANOTHER MOVING INTO
THE AREA FRIDAY INTO SATURDAY. STILL SOME DECENT DIFFERENCES FOR THE
INCOMING SYSTEM SO NOT OVERLY CONFIDENT ON WHAT TO EXPECT BUT RIGHT
NOW LOOKS COLD ENOUGH FOR ALL SNOW...JUST A MATTER OF WHETHER OR NOT
THIS IS A SYSTEM THAT MOVES THROUGH RATHER QUICKLY OR ONE THAT TAKES
ON JUST A TOUCH OF NEGATIVE TILT LIKE THE ECMWF SUGGESTS AND BRINGS
IN A BETTER CHANCE FOR HEAVIER AMOUNTS. UNFORTUNATELY NO WAY TO
REALLY FIGURE THIS OUT RIGHT NOW SO WILL CONTINUE TO CARRY A CHANCE
OF SNOW THURSDAY NIGHT INTO SATURDAY. FOR NOW WEDNESDAY AND THURSDAY
LOOK MAINLY DRY WITH SLIGHTLY BELOW NORMAL HIGH TEMPERATURES THROUGH
THE PERIOD. OVERNIGHT LOWS WILL LIKELY BE AT OR ABOVE NORMAL DURING
THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1117 AM CST SAT DEC 20 2014
POOR AVIATION CONDITIONS WILL CONTINUE THROUGH THE PERIOD...WITH
IFR TO LIFR CIGS AND VIS LIKELY. NOT REALLY EXPECTING MUCH CHANGE
FROM THE CURRENT CONDITIONS...SO MAINLY WENT WITH A PERSISTENCE
FORECAST. SOME SIGNS THAT DENSER FOG AND LIFR CIGS WILL SPREAD A
BIT FURTHER EAST TONIGHT TOWARDS INTERSTATE 29 TONIGHT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...08
AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
322 PM EST SAT DEC 20 2014
.SHORT TERM...(TONIGHT THROUGH MONDAY)...CLOUDS ARE SLOWLY ERODING
FROM THE WEST THIS AFTERNOON...AND MOST OF THE TN VALLEY SHOULD BE
CLEAR BEFORE MIDNIGHT IF THE TREND CONTINUES AND IF THE HRRR IS
ACCURATE. WITH THE EXPECTED CLEARING AND CALM WINDS...CONDITIONS
APPEAR FAVORABLE FOR FOG TONIGHT. CROSSOVER TEMPERATURES ARE
ESPECIALLY FAVORABLE NORTH...SO WILL MENTION PATCHY/AREAS OF FOG
THERE AS WELL AS SW NC. FOG SHOULD BE SLOW TO DISSIPATE DUE TO THE
LOW SUN ANGLE AND WEAK MIXING TOMORROW MORNING. THE REST OF THE DAY
SHOULD BE MOSTLY SUNNY...WITH HIGH CLOUDS INCREASING LATE IN THE
DAY.
A WEAK SHORTWAVE TROUGH IN THE SOUTHERN STREAM NOW OVER TX WILL BE
LIFTING E-NE AND CROSSING OUR AREA SUNDAY NIGHT AND MONDAY. WITH THE
JET POSITIONED FROM SOUTHERN AL TO THE NC COAST...THE MAJORITY OF
LIFT AND DEEP MOISTURE APPEARS TO BE EAST OF OUR AREA. THE NAM
PULLS MORE MOISTURE INTO OUR AREA THAN THE GFS...BUT EVEN THE NAM
SHOWS THIS MOISTURE MAINLY BELOW THE -10C LEVEL...SUGGESTING THAT
DRIZZLE IS MORE LIKELY THAN MEASURABLE RAINFALL. AS A RESULT...WILL
CUT BACK POPS TO A CHANCE EAST TO NOTHING WEST...BUT MENTIONING
DRIZZLE EVERYWHERE. QPF WILL BE REDUCED AS WELL...TO NO MORE THAN A
TENTH IN THE MOUNTAINS. TEMPERATURE PROFILES IN ALL THE MODEL
SOUNDINGS INDICATE ALL LIQUID PRECIP. THE TROUGH PASSAGE SHOULD
BRING AN END TO ANY RAIN/DRIZZLE ON MONDAY AFTERNOON.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)...QUITE THE ACTIVE LONG
TERM PERIOD WITH A HIGHLY AMPLIFIED SYSTEM COMING IN FOR CHRISTMAS THAT
WILL BRING...RAIN...MAYBE A FEW STORMS...WIND...AND PERHAPS SNOW.
MONDAY NIGHT INTO TUESDAY HEIGHTS WILL BE QUICKLY BUILDING OUT AHEAD
OF A DEEP TROUGH MOVING ACROSS THE CENTRAL U.S. AND SOUTHERN PLAINS.
THIS WILL ALLOW FOR MONDAY NIGHT AND TUESDAY DAY TO BE UNSEASONABLE
WARM. LOWS MONDAY NIGHT WILL BE 10 TO 12 DEGREES ABOVE NORMAL. HIGHS
ON TUESDAY WILL BE IN THE MID TO UPPER 50S...5 TO 10 DEGREES ABOVE
NORMAL. RAIN CHANCES INCREASE ON TUESDAY AS THIS HIGHLY AMPLIFIED
AND DEEP TROUGH IS ON OUR DOORSTEP BY TUESDAY AFTERNOON. DID DECIDE
TO INTRODUCE SLIGHT CHANCE OF THUNDERSTORMS FROM KNOXVILLE SOUTH
TUESDAY AFTERNOON INTO TUESDAY NIGHT. CAPE IS VERY WEAK BUT SHEAR
AND HELICITY ARE ROBUST...IN LARGE PART DUE TO A STRONG 850MB JET OF
40 TO 50 KTS THAT WILL BE IN PLACE. BETTER INSTABILITY EXISTS
FURTHER TO OUR SOUTH AND SOUTHWEST BUT DID WANT TO MENTION A STORM
OR TWO POSSIBLE ACROSS OUR CENTRAL AND SOUTHERN AREAS. ABUNDANT
MOISTURE AND STRONG LIFT WILL LEAD TO SOME DECENT RAINFALL ACROSS
THE AREA FOR TUESDAY NIGHT INTO WEDNESDAY...MORE SO ACROSS THE
SOUTHERN AREAS. CURRENT GFS SOUNDINGS SHOW PW VALUES RANGING FROM
1.40 TO 1.20 INCHES FROM SOUTH TO NORTH. THIS PUTS US AT 2SD ABOVE
NORMAL FOR THIS TIME OF YEAR. I DON`T THINK FLOODING WILL BE A
CONCERN THOUGH BECAUSE OF HOW QUICKLY THIS SYSTEM IS MOVING. SO NOW
THAT WE HAVE TALKED ABOUT RAIN AND STORMS...LET`S TALK ABOUT SNOW.
CHRISTMAS EVE IS LOOKING TO BE RATHER NASTY WITH THE DEEP TROUGH AND
ASSOCIATED SURFACE LOW MOVING ACROSS. LIGHT TO MODERATE RAIN
CONTINUES WEDNESDAY MORNING WITH STRONG COLD FRONT MOVING THROUGH BY
LATE AFTERNOON INTO EARLY EVENING. AS THE FRONT MOVES THROUGH EXPECT
RAIN TO CHANGE TO SNOW ACROSS MUCH OF THE AREA ALONG WITH BREEZY
WINDS. THE MILLION DOLLAR QUESTION IS HOW MUCH MOISTURE WILL BE
LEFT. MODELS HAVE BEEN CONSISTENT IN SHOWING THE HIGHLY AMPLIFIED
SYSTEM FOR SEVERAL DAYS OUT BUT HAVE NOT BEEN WITH THE EXACT
PLACEMENT OF THE LOW. THE LATEST FEW MODEL RUNS OF THE ECMW AND THE
GFS ARE TRENDING THE LOW FURTHER TO OUR WEST. THIS MEANS THAT THE
BULK OF THE MOISTURE WILL HAVE PASSED OFF TO OUR EAST BEFORE IT GETS
COLD ENOUGH TO SNOW BACK BEHIND THE COLD FRONT. IT LOOKS LIKE OUR
SNOW WILL BE IN THE FORM OF WRAP AROUND MOISTURE. THE CHANGEOVER TO
SNOW LOOKS TO OCCUR SOMETIME ON WEDNESDAY EVENING WITH SNOW
LINGERING THROUGH EARLY CHRISTMAS MORNING. MOST OF THE PRECIP DURING
THIS TIME FRAME SHOULD BE IN THE FORM OF SCATTERED LIGHT SNOW
SHOWERS. LITTLE TO NO ACCUMULATION EXPECTED AT THIS TIME FOR LOWER
ELEVATIONS. HIGHER ELEVATIONS MAY GET AN INCH OR TWO. AGAIN...ALL OF
THE ABOVE DEPENDS ON THE TRACK OF THE LOW...BUT THIS IS HOW IT`S
LOOKING FOR NOW.
THIS SYSTEM QUICKLY EXITS ON THURSDAY...CHRISTMAS DAY...AS IT RACES
OFF TO THE NORTHEAST. ANOTHER QUICK MOVING WEAKER SYSTEM MOVES
THROUGH ON FRIDAY INTO SATURDAY THAT COULD BRING SOME LIGHT SHOWERS
TO THE AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 33 53 41 56 / 0 10 20 10
KNOXVILLE MCGHEE TYSON AIRPORT, TN 31 50 38 55 / 0 10 20 10
OAK RIDGE, TN 30 50 38 55 / 0 0 20 10
TRI CITIES AIRPORT, TN 30 48 35 51 / 0 10 30 40
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS/SR
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1144 AM CST SAT DEC 20 2014
.AVIATION.../18Z TAFS/
MVFR CIGS CONTINUE ACROSS THE REGION. MORNING SOUNDINGS AT
KCRP/KDRT INDICATE INVERSIONS SO EXPECT CLOUD COVER TO HANG STRONG
INTO THE AFTERNOON. COULD SEE A FEW BREAKS DURING THE
AFTERNOON...MAINLY ACROSS THE WEST. WILL MAINTAIN MVFR CONDITIONS
INTO THE OVERNIGHT HOURS. SHOULD SEE IFR CONDITIONS DEVELOP
10Z-12Z THEN LIFT BACK TO MVFR/VFR SUNDAY AFTERNOON. WINDS WILL
REMAIN N/NE NEAR 10 KNOTS TODAY...SE NEAR 10 KNOTS AT KDRT. WILL
SEE A SOUTHERLY FLOW DEVELOP ON SUNDAY.
&&
.PREV DISCUSSION... /ISSUED 559 AM CST SAT DEC 20 2014/
AVIATION... /12Z TAF CYCLE/
LOW END MVFR CIGS ONGOING THIS MORNING FOR KSAT/KAUS/KSSF WITH
KDRT BOUNCING BETWEEN LOW MVFR AND VFR AS BKN010 TO SCT010 KEEP
BEING OBSERVED. WILL GO ON PESSIMISTIC SIDE FOR KDRT THROUGH
17-20Z BEFORE EVENTUAL BREAK OUT TO VFR OCCURS THIS AFTERNOON. FOR
CENTRAL SITES HOWEVER, FEEL MVFR WILL RULE THROUGH THE AFTERNOON
PER RAP/NAM SOUNDINGS AND HRRR OUTPUT. TOP OF STRATUS CLOUD DECK
LOOKS TO BE AROUND 3.5-4 KFT, RESULTING IN A 1-1.5 KFT THICK
STRATUS CLOUD LAYER. OVERNIGHT, IFR IS LIKELY FOR ALL SITES WITH
ANOTHER SLOW IMPROVEMENT TO MVFR/VFR ON SUNDAY AFTN.
SURFACE WINDS WILL BE N/NNE AT 10 KTS THROUGH THE DAY AND THEN
BECOME LIGHT AND VARIABLE OVERNIGHT TONIGHT. /ALLEN/
PREV DISCUSSION... /ISSUED 357 AM CST SAT DEC 20 2014/
SHORT TERM (TODAY THROUGH SUNDAY)...
AN UPPER LEVEL TROUGH SLOWLY DEVELOPS OVER THE PLAINS STATES. A
SERIES OF WEAK UPPER LEVEL SHORT-WAVES TRAVERSE THE TROUGH TO
GENERATE WEAK ISENTROPIC LIFT. MOISTURE DEPTH ONLY SUFFICIENT FOR
MAINTENANCE OF STRATUS/STRATOCUMULUS DECK WITH NO RAIN EXPECTED.
BELOW AVERAGE DAYTIME AND ABOVE AVERAGE NIGHTTIME TEMPERATURES ARE
EXPECTED DUE TO THE CLOUD COVER. PATCHY FOG WILL PERSIST ACROSS
HIGHER ELEVATIONS OF THE HILL COUNTRY THROUGH AROUND 9 AM THIS
MORNING.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
THE UPPER LEVEL TROUGH SHIFTS EAST BY TUESDAY. SOUTHWESTERLY LOWER
LEVEL FLOW DEVELOPS ALLOWING SKIES TO MOSTLY CLEAR WITH WELL ABOVE
AVERAGE TEMPERATURES MONDAY. A MID LEVEL SHORT-WAVE MOVING THROUGH
THE TROUGH FORCES A COLD FRONT TO MOVE ACROSS SOUTH CENTRAL TEXAS
TUESDAY MORNING. THERE IS SUFFICIENT MOISTURE FOR ISOLATED SHOWERS
ALONG THE FRONT ACROSS FAR EASTERN AREAS AND HAVE INTRODUCED
MENTION. ZONAL FLOW ALOFT FOR MID TO LATE WEEK WITH AN UPPER LEVEL
TROUGH MOVING ACROSS THE PLAINS FORCING ANOTHER COLD FRONT ACROSS
SOUTH CENTRAL TEXAS FRIDAY. NO RAIN IS EXPECTED AS MOISTURE DEPTH
WILL BE MINIMAL. COOLER TEMPERATURES TUESDAY INTO WEDNESDAY...THEN
WARMER THURSDAY CHRISTMAS DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 56 44 60 48 70 / - - - - -
AUSTIN BERGSTROM INTL AIRPORT 56 42 59 46 70 / - - - - -
NEW BRAUNFELS MUNI AIRPORT 56 45 61 48 71 / - - - - -
BURNET MUNI AIRPORT 54 40 58 46 69 / - - - - -
DEL RIO INTL AIRPORT 60 45 62 46 73 / - - - - -
GEORGETOWN MUNI AIRPORT 54 40 58 47 69 / - - - - -
HONDO MUNI AIRPORT 59 45 62 46 72 / - - - - -
SAN MARCOS MUNI AIRPORT 57 43 61 46 70 / - - - - -
LA GRANGE - FAYETTE REGIONAL 57 45 61 48 71 / - - - - -
SAN ANTONIO INTL AIRPORT 57 45 61 49 72 / - - - - -
STINSON MUNI AIRPORT 58 46 62 49 72 / - - - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...10
SYNOPTIC/GRIDS...29
PUBLIC SERVICE/DATA COLLECTION...00
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