Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/16/14
AREA FORECAST DISCUSSION
NWS PUEBLO CO
306 PM MST SUN DEC 14 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 306 PM MST SUN DEC 14 2014
THE UPR LOW IS MOVING INTO THE FAR SWRN CORNER OF KS THIS
AFTERNOON...WITH SOME THUNDERSTORMS CONTINUING OVER PORTIONS OF THE
SERN CO PLAINS. SATELLITE IMAGES SHOW THAT DRY AIR HAS WRAPPED INTO
THE ERN CO BORDER AREA...WITH THE TSTMS BEING ON THE WRN
EDGE...MAINLY OVR BENT COUNTY. TEMPS OVR THE SERN PLAINS ARE MOSTLY
IN THE 40S...WITH LOWER 50S NR THE KS BORDER. ALONG THE I-25
CORRIDOR TEMPS ARE IN THE 30S WITH PERIODS OF RAIN...SOMETIMES MIXED
WITH SNOW...EXCEPT OVR NRN PORTIONS OF EL PASO COUNTY WHERE TEMPS
ARE A LITTLE COLDER AND THE PCPN IS IN THE FORM OF SNOW. THOUGH WEB
CAMS SHOW ONLY LIGHT ACCUMULATIONS ON GRASSY AREAS OVR NRN EL PASO
COUNTY.
THE CURRENT POSITION OF THE UPR LOW IS WRAPPING THE BEST MSTR INTO
NERN CO. THE LOW IS FORECAST TO TRACK ENE TONIGHT...WITH MSTR
CONTINUING TO WRAP AROUND INTO ERN CO INTO THE LATE NIGHT HOURS.
THE NAM AND RUC ALSO CONTINUE TO SHOW HEAVY SNOW ACCUMULATIONS THIS
EVENING OVR PORTIONS OF THE FAR SERN CO PLAINS...WHICH IS WORRISOME
BUT AM SURE THIS IS OVERDONE. AS THE TEMPS COOL THIS EVENING OVR THE
FAR SERN PLAINS PCPN SHOULD CHANGE OVR TO SNOW...BUT IT WL TAKE
AWHILE FOR THE TEMPS TO COOL NR THE ERN BORDER. HAVE DECIDED TO PUT
A COUPLE INCHES OF SNOW IN THE FORECAST FOR SOME PORTIONS OF THE
SERN PLAINS THIS EVENING...BUT THERE IS A LOT OF UNCERTAINTY.
ELSEWHERE...WEB CAMS ARE NOT SHOWING MUCH IN MOST AREAS IN THE WAY
OF SNOWFALL AND ACCUMULATIONS. LIGHT SNOW IS STILL EXPECTED OVR THE
SANGRES THIS EVENING...BUT IT LOOKS LIKE SIGNIFICANT ACCUMS WL NOT
LONGER OCCUR AND WL THEREFORE CANCEL THE ADVISORY FOR THAT AREA WITH
THE AFTERNOON FORECAST ISSUANCE. WL ALSO CANCEL THE ADVISORY FOR
THE LEADVILLE AREA...BUT WL KEEP THE ADVISORY FOR THE SAWATCH AND
MOSQUITO RANGES GOING TO 01Z.
FOR LATE TONIGHT...AS THE UPR LOWS CONTINUES MOVING AWAY FROM THE
AREA...PCPN OVR THE SERN PLAINS WL BE ON THE DECREASE AND SHOULD
MOSTLY BE OVR BY MON MORNING. THE NW FLOW ALOFT WL KEEP SOME ISOLD
TO SCT SNOW SHOWERS GOING THRU THE NIGHT AND INTO MON MORNING OVR
THE CENTRAL CO MTNS...BUT ONLY LIGHT ADDITIONAL ACCUMULATIONS ARE
EXPECTED. WITH DECREASING CLOUDS TONIGHT IN THE SAN LUIS
VALLEY...SOME LOW CLOUDS AND FOG MAY DEVELOP.
MONDAY WL GENERALLY BE A DRY DAY WITH HIGHS BEING CLOSE TO AVERAGE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 306 PM MST SUN DEC 14 2014
.TUESDAY AND WEDNESDAY...DISTURBANCE MOVES ONSHORE TUESDAY AND
INTO COLORADO ON WEDNESDAY. SYSTEM WEAKENS AS IT APPROACHES
COLORADO AND IT IS MOVING RELATIVELY FAST. GRIDS HAVE INCREASING
POPS OVER THE MOUNTAINS ON WEDNESDAY...ESPECIALLY THE CONTINENTAL
DIVIDE REGION. AT THIS TIME...IT APPEARS AMOUNTS WILL LIKELY
REMAIN BELOW ADVISORY CRITERIA. WEAK UPSLOPE ONE THE PLAINS WILL
TEND TO KEEP TEMPERATURES NEAR SEASONAL VALUES DESPITE SOME
WARMING ALOFT.
.THURSDAY AND FRIDAY...SECOND...STRONGER TROUGH IS FORECAST TO
MOVE ONSHORE WEDNESDAY NEAR NORTHERN CALIFORNIA AND MOVE
SOUTHEAST. MOST OF THE MODELS AND ENSEMBLE MEMBERS HAVE THE TROUGH
MOVING ACROSS SOUTHERN NEW MEXICO ON THURSDAY. THIS TRACK KEEP
MUCH OF THE HEAVIER PRECIPITATION SOUTH OF THE STATE. GFS AND EC
SUGGEST A MUCH WEAKER DISTURBANCE MAY MOVE ACROSS NORTHERN
COLORADO. GFS AND EC PRINT SOME LIGHT QPF ON THE PLAINS
THURSDAY...ASSOCIATED WITH SOME WEAK UPSLOPE FLOW. DECIDED TO ADD
SOME ISOLATED POPS ON THE PLAINS...WHICH MATCHES SURROUNDING
OFFICES BETTER. IF THE CURRENT PATH OF THE STRONGER DISTURBANCE
REMAINS WELL SOUTH OF COLORADO...ANTICIPATE ANY PRECIPITATION ON
THE PLAINS AND EASTERN MOUNTAINS WILL BE LIGHT.
.SATURDAY AND SUNDAY...NEXT DISTURBANCE MOVES ONSHORE LATE FRIDAY
AND SLOWLY MOVES SOUTHEAST. THE 12Z GFS HAS AN INTERESTING
SOLUTION WITH THE CUTOFF PASSING OVER THE FOUR CORNERS REGION.
THIS PATH COULD BRING SNOW TO MUCH OF THE CWA. EC AND A FAIR
NUMBER OF ENSEMBLES MEMBERS HAVE THE CUTOFF MOVING FURTHER SOUTH
AND WEST...REMAINING WELL SOUTH OF COLORADO. THIS SOLUTION WOULD
LIMIT SNOWFALL AMOUNTS IN THE CWA. --PGW--
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 306 PM MST SUN DEC 14 2014
KALS SHOULD HAVE VFR CONDITIONS TONIGHT AND MONDAY...HOWEVER THERE
IS THE POTENTIAL FOR SOME LOW STRATUS AND FOG TO DEVELOP LATE
TONIGHT INTO EARLY MONDAY...BUT NOT CONFIDENT ENOUGH TO PUT IN THE
TERMINAL FORECAST.
KCOS WL STILL HAVE SOME SNOW SHOWERS IN THE VCNTY THIS EVENING AND
COULD HAVE PERIODS OF MVFR CONDITIONS IN SHOWERS...OTHERWISE VFR
CONDITIONS ARE EXPECTED TONIGHT AND MONDAY.
KPUB WL HAVE VFR CONDITIONS TONIGHT AND MONDAY...ALTHOUGH THERE WILL
STILL BE SOME SHOWERS IN THE VCNTY THIS EVENING AND THERE IS THE
POTENTIAL FOR SOME BRIEF MVFR CONDITIONS IN SHOWERS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ058-
060.
&&
$$
SHORT TERM...28
LONG TERM...PGW
AVIATION...28
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
913 PM EST MON DEC 15 2014
...AREAS OF DENSE FOG LIKELY ACROSS INTERIOR NORTHEAST FLORIDA
TONIGHT...
.UPDATE...
HIGH PRESSURE CENTERED OVER THE NORTH CENTRAL FLORIDA GULF COAST
WILL SLOWLY DRIFT SOUTHEAST TONIGHT. MOIST SOUTHWEST FLOW ON THE
NORTH SIDE OF THIS HIGH HAS ALREADY RESULTED IN A DENSE SEA FOG
BANK ALONG THE BIG BEND COAST OF FLORIDA. THIS FOG IS EXPECTED TO
SLOWLY SPREAD INLAND TO THE I-75 CORRIDOR THROUGH MIDNIGHT. A
DENSE FOG ADVISORY IS LOOKING MORE AND MORE LIKELY FOR AT LEAST
OUR INTERIOR NORTHEAST FLORIDA COUNTIES LATER TONIGHT. THE NAM12
AND HRRR ARE MOST ROBUST WITH THE FOG WHEREAS THE GFS GUIDANCE NOT
SO MUCH. THE LATEST LAMP GUIDANCE HAS YET TO LATCH ON TO THIS
IDEA...BUT THE NAM AND HRRR ARE DEFINITELY MORE TRUSTWORTHY WHEN
IT COMES TO ADVECTION FOG FROM THE GULF OF MEXICO.
WILL CONTINUE TO MONITOR THE FOG CHANNEL SATELLITE IMAGERY TO
TRACK THE INLAND PROGRESSION OF THE FOG BANK THIS EVENING AND WE
MAY NEED TO GO AHEAD AND HOIST A DENSE FOG ADVISORY FOR AT LEAST
OUR NORTHEAST FLORIDA COUNTIES ALONG AND WEST OF THE I-75
CORRIDOR. THERE IS ALSO SOME SUGGESTION THAT THE DENSE FOG BANK
COULD MOVE EVEN FARTHER INLAND...SPREADING EAST OF THE I-75
CORRIDOR LATE TONIGHT...AND POSSIBLY MOVING INTO THE JACKSONVILLE
AREA AROUND THE TIME OF SUNRISE TUESDAY MORNING. NOT AS CONFIDENT
WITH THIS SCENARIO BUT IT IS CERTAINLY POSSIBLE.
OTHERWISE...CHILLY TEMPS WILL PREVAIL OVERNIGHT WITH LOWS
GENERALLY RANGING FROM THE UPPER 30S TO LOWER 40S.
&&
.AVIATION...EXPECT LOW CLOUDS AND FOG NOW OVER THE BIG BEND TO
AFFECT GNV WITH IFR/LIFR CONDITIONS BETWEEN 06Z-14Z. FOG AND CLOUDS
MAY REACH THE EAST COAST LATE TONIGHT WITH IFR CONDITIONS POSSIBLE
09Z-14Z. HAVE KEPT VFR CONDITIONS AT SSI AS MODEL GUIDANCE DOES NOT
EXPECT LOW CIGS/VSBYS THERE. VFR CONDITIONS AFTER 14Z AT ALL TAF
SITES.
&&
.MARINE...
SOUTHWEST WINDS WILL GRADUALLY INCREASE TO 10 KNOTS OVERNIGHT AS
HIGH PRESSURE OVER NORTH CENTRAL FLORIDA DRIFTS SOUTHEAST IN
ADVANCE OF AN APPROACHING COLD FRONT. SOUTHWEST WINDS WILL
CONTINUE TO INCREASE ON TUESDAY...REACHING 10 TO 15 KNOTS BY
TUESDAY AFTERNOON.
RIP CURRENTS: LOW RISK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 39 71 43 63 / 0 20 10 0
SSI 47 69 46 62 / 0 20 20 0
JAX 39 73 46 65 / 0 10 10 10
SGJ 43 72 50 64 / 0 0 10 10
GNV 39 73 48 68 / 0 10 10 10
OCF 37 72 50 70 / 0 10 10 10
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
SHULER/ZIBURA/
AREA FORECAST DISCUSSION
NWS BOISE ID
815 PM MST MON DEC 15 2014
.DISCUSSION...SNOW AMOUNTS HAVE INDEED BEEN LIGHT WITH BURNS
REPORTING 0.01 LIQUID THIS EVENING. SNOTEL IN THE STEENS MTN AREA
OVER LAST 24 HRS PICKED UP LESS THAN 0.2 OF SNOW. RADAR FILLED IN
ACROSS MUCH OF FAR SW IDAHO BUT CLOUD BASES /BOISE AND NAMPA/
REMAINED RATHER HIGH /6-8K FT AGL/ COULD SEE A FEW FLURRIES ACROSS
THE TREASURE VALLEY BEFORE MIDNIGHT AS THIS AREA LIFTS TOWARDS THE
BOISE MOUNTAINS AND CAMAS PRAIRIE OVER NIGHT. ONLY HRRR AND NOW
01Z RAP13 AMONG 18ZNAM/GFS 12ZEC CAPTURED LOW QPF ACROSS THE
OWYHEES AND BOISE MTNS SO DID A QUICK UPDATE FOR HIGHER POPS AND
UP TO HALF INCH OF SNOW /OWYHEE PEAKS/ WITH THIS FEATURE. STILL
EXPECT MAIN AREA OF VERY LOW QPF AND LIGHT SNOW OVERNIGHT ACROSS
SE OREGON AS MODERATE SSW FLOW ALOFT BRINGS A PRECIP SHADOW TO
THE IDAHO TREASURE VALLEY AND WEST MAGIC VALLEY. CENTRAL IDAHO
MOUNTAINS SHOULD ALSO GET LIGHT SNOW BUT LITTLE IF ANY
ACCUMULATION. AS THIS FEATURE EXITS EARLY TUESDAY THERE SHOULD BE
SOME PATCHY FOG WHERE WINDS DIE OFF. ANOTHER UPDATE TO ADD FOG FOR
THOSE LOCATIONS...INCLUDES MCCALL.
&&
.AVIATION...AREAS OF -SN ACROSS EASTERN OREGON OVERNIGHT WITH
OCCASIONAL MVFR/IFR...INCLUDING KBNO AND POSSIBLY KBKE VICINITY.
LESS COVERAGE ON THE IDAHO SIDE BUT DO EXPECT OCCASIONAL MVFR-IFR IN
-SN OVER MOUNTAINS. IFR IN FOG LIKELY AT KMYL AFTER 06Z...LIFTING
BY 20Z. CHANCE OF -SN OVER THE TREASURE AND MAGIC VALLEYS OVERNIGHT
BUT VFR SHOULD PREVAIL. SURFACE WINDS GENERALLY 10 KNOTS OR LESS...
EXCEPT IN THE SNAKE RIVER VALLEY FROM KBOI EAST TO KTWF/KJER WITH
EASTERLY WINDS OF 15-25 KNOTS. WINDS ALOFT...SOUTHERLY 15-25 KNOTS
UP THROUGH 10K FEET MSL. CHANCE OF MVFR IN -SN TUESDAY...ESPECIALLY
OVER THE MOUNTAINS.
&&
.PREV DISCUSSION...
SHORT TERM...TONIGHT THROUGH WEDNESDAY...CLOUD COVER IS
MOVING INTO THE AREA AHEAD OF AN UPPER LEVEL TROUGH WITH ITS AXIS
ALONG THE CALIFORNIA COAST. AS IT MOVES IN...THE PRESSURE GRADIENT
WILL TIGHTEN UP WITH HIGHER PRESSURE TO THE EAST...WHICH WILL
BRING SOME GUSTY EAST/SOUTHEAST WINDS TO THE WESTERN MAGIC VALLEY
AND TREASURE VALLEY THROUGH TUESDAY. PRECIP CHANCES WILL BEGIN
THIS EVENING IN SE OREGON AND SPREAD THROUGH SW IDAHO THROUGH THE
NIGHT. QPF AMOUNTS LOOK TO BE VERY LOW...WITH MOST AREAS EXPECTED
TO RECEIVE LESS THAN ONE TENTH OF AN INCH. SNOW LEVELS WILL BE AT
VALLEY FLOORS TONIGHT AND SLOWLY RISE TO AROUND 3500-4000 FEET BY
WEDNESDAY MID-DAY. SNOW ACCUMULATIONS OVER THE NEXT 36 HOURS IN
THE MOUNTAINS ARE EXPECTED TO BE UNDER AN INCH. HOWEVER...PRECIP
CHANCES TAPER OFF EARLY WEDNESDAY AS THE TROUGH AXIS WILL BE NEAR
THE CA/NV BORDER AND THE UPPER LOW BEGINS TO DIGS SOUTH.
LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...SPLITTING TROUGH WILL
CONTINUE TO SLOWLY MIGRATE EASTWARD ACROSS THE WEST WEDNESDAY NIGHT-
THURSDAY. THE NORTHERN PORTION OF THE TROUGH WILL MOVE ACROSS
OREGON/IDAHO FOR A CHANCE OF MOUNTAIN SNOW/SLIGHT CHANCE OF VALLEY
RAIN AND SNOW. MODELS AGREE THAT THE QPF WILL BE LOW. A SHORT-LIVED
UPPER RIDGE AND ACCOMPANYING DRIER CONDITIONS WILL SLIDE INTO THE
AREA THURSDAY NIGHT. ANOTHER UPPER TROUGH ARRIVES ON FRIDAY FOR A
CHANCE OF VALLEY RAIN/SNOW AND MOUNTAIN SNOW THROUGH FRIDAY NIGHT.
THE PATTERN CHANGES OVER THE WEEKEND THROUGH EARLY NEXT WEEK AS AN
UPPER RIDGE STRENGTHENS OFF THE CALIFORNIA COAST AND A MOIST PACIFIC
FLOW RIDES OVER THE TOP OF THE RIDGE AND PUSHES INTO THE PACIFIC
NORTHWEST. THIS WILL BRING A BETTER CHANCE OF PRECIP AND POTENTIALLY
HIGHER QPF TO THE MOUNTAINS. TEMPERATURES WILL REMAIN SLIGHTLY ABOVE
NORMAL.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...VM
AVIATION.....TL
PREV SHORT TERM...EP
PREV LONG TERM....BW/DD
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
304 PM CST SUN DEC 14 2014
.SHORT TERM...
302 PM CST
TONIGHT THROUGH MONDAY...
CLOUDY AND OVERALL DREARY WEATHER CONTINUES ACROSS THE REGION
TODAY...HOWEVER WARMER TEMPERATURES ARE IN PLACE AND WILL CONTINUE
THROUGH TOMORROW AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM.
LOW PRESSURE IS TAKING SHAPE OVER THE OK/TX PANHANDLE REGION TODAY
AS A CLOSED UPPER LOW AND AMPLIFIED LONGWAVE TROUGH EMERGE OVER THE
PLAINS STATES. MUCH OF THE SAME IS IN STORE AHEAD OF THIS SYSTEM REST
OF TODAY AND TONIGHT WITH OVERCAST CONDITIONS...SOME FOG...AND
OCCASIONAL DRIZZLE. TEMPERATURES WONT FALL OFF TONIGHT WITH WARM
ADVECTION AND DEWPOINTS IN THE MID 40S. RAIN CHANCES WILL RAMP UP
MID TO LATE MORNING MONDAY ACROSS THE WEST/SOUTHWEST COUNTIES...THEN
BY EARLY/MID AFTERNOON FOR THE CHICAGO AREA AS LEAD UPPER SHORTWAVE
EJECTS AHEAD OF THE UPPER LOW COINCIDING WITHIN A CORRIDOR OF
MODERATE WARM AIR ADVECTION THAT WILL LIFT NORTHEAST ACROSS THE
FORECAST AREA. FORECAST SOUNDINGS DO HINT AS SOME VERY MODEST
INSTABILITY AT TIMES WITH THIS LEAD WAVE WITH LAPSE RATES ABOVE
AROUND H6 OR SO NEAR MOIST ADIABATIC. PROBABILITY OF TAPPING INTO
THIS SEEMS REALLY LOW SO WONT INTRODUCE ANYTHING INTO GRIDS AT THIS
TIME...BUT WOULDNT BE SURPRISED IF THERE WERE ANY ISOLATED
EMBEDDED HEAVIER SHOWERS OR THUNDERSTORMS.
DEUBELBEISS
&&
.LONG TERM...
302 PM CST
MONDAY NIGHT THROUGH SUNDAY...
VERTICALLY STACKED OCCLUDED LOW LIFTS SLOWLY NORTHEAST ACROSS THE
AREA MONDAY NIGHT THROUGH TUESDAY. INITIAL BAND OF RAIN WHICH
SPREADS ACROSS THE AREA DURING THE DAY MONDAY WILL BE LIFTING
NORTHEAST AND WEAKENING DURING THE EVENING...AS STRONGEST LOW LEVEL
MOISTURE TRANSPORT BECOMES FOCUSED ACROSS THE OHIO VALLEY NEAR THE
TRIPLE POINT OF THE SURFACE OCCLUSION. GUIDANCE IN GENERAL AGREEMENT
THAT A SECONDARY COLD FRONT INITIALLY OVER THE UPPER MISSISSIPPI
VALLEY WILL BECOME A SECONDARY FOCUS FOR PRECIPITATION...BENEATH
UPPER LOW CENTER AND ALONG WARM SIDE OF LOW LEVEL FRONTOGENESIS
MAXIMA WITH SECONDARY FRONT. THUS HAVE GENERALLY FOLLOWED HIGHER
MODEL POPS FOR MONDAY NIGHT. STACKED CIRCULATION PASSES ACROSS
NORTHEAST ILLINOIS AND SOUTHERN LAKE MICHIGAN EARLY TUESDAY MORNING
AND TAKING THE STEADIEST PRECIPITATION ALONG WITH IT. LOW LEVEL COLD
AIR THEN SPREADS IN SMARTLY IN ITS WAKE...WITH ANY LINGERING LIGHT
RAIN MIXING WITH OR CHANGING TO SOME LIGHT SNOW FROM THE WEST FROM
MID-MORNING THROUGH THE AFTERNOON. LITTLE IN THE WAY OF QPF BY THIS
TIME AND FORECAST SOUNDING PROFILES APPEAR SOMEWHAT MARGINAL FOR ANY
SIGNIFICANT SNOW...EITHER DUE TO MOIST LOW LEVEL THERMAL PROFILES
NEAR FREEZING OR EROSION OF MID-LEVEL MOISTURE PREVENTING EFFECTIVE
ICE NUCLEATION ESPECIALLY DURING THE AFTERNOON. IN EITHER CASE...
LIGHT SNOW/RAIN MIX WITH NO ACCUMULATION APPEARS SUITABLE AT THIS
TIME. PERHAPS OF MORE IMPACT WILL BE A FALLING TEMPERATURE TREND...
AS THE WARMEST LOW LEVEL AIR AHEAD OF THE SURFACE LOW WILL HAVE
PRE-DAWN TEMPS IN THE LOW-MID 40S...THEN FALLING INTO THE 30S DURING
THE MORNING AND MID-DAY HOURS AS THE LOW AND SECONDARY COLD FRONT
MOVE EAST. TO ADD TO THE CHILL...WINDS WILL QUICKLY BECOME BLUSTERY
FROM THE WEST-NORTHWEST NEAR 30 MPH...SENDING WIND CHILL READINGS
INTO THE LOW-MID 20S BY LATE AFTERNOON. THE COLDER AND MUCH DRIER
AIR DOES LOOK TO QUICKLY BRING AN END TO ANY LINGERING LIGHT SNOW BY
EVENING...EXCEPT FOR A FEW LIGHT LAKE EFFECT SNOW SHOWERS WHICH
COULD CLIP NORTHEAST PORTER COUNTY TUESDAY NIGHT. SHALLOW
EQUILIBRIUM HEIGHTS...BELOW 5000 FT...SHOULD PRECLUDE ANY
SIGNIFICANT ACCUMULATION THERE.
THE SECOND HALF OF THE WEEK FROM WEDNESDAY THROUGH FRIDAY LOOK TO BE
SEASONABLY COOL AND SOMEWHAT BLUSTERY...AS A SECOND CLOSED MID-LEVEL
LOW DEVELOPS WITHIN ELONGATED WEST-EAST TROUGH FROM MINNESOTA AND
WISCONSIN EAST ACROSS THE LAKES. MEDIUM-RANGE OF GFS/ECMWF RUNS BOTH
INDICATE A LITTLE SHORT WAVE PIVOTING SOUTHEAST ACROSS THE AREA
WEDNESDAY AFTERNOON OR EVENING...THOUGH SOUNDINGS AND TIME/HEIGHT
PLOTS SHOW VERY DRY MID-LEVEL AIR AND NO QPF IS PRODUCED. OTHERWISE
HIGH PRESSURE SLOWLY BUILDS INTO THE AREA BY FRIDAY WITH DAYTIME
HIGHS NEAR FREEZING AND OVERNIGHT MINS IN THE TEENS AND LOWER 20S
ARE EXPECTED...AT OR JUST A BIT BELOW AVERAGE.
BY THE WEEKEND...ATTENTION TURNS TO AN UPPER LEVEL TROUGH PROJECTED
TO BE MOVING ACROSS THE DESERT SOUTHWEST AND SOUTHERN PLAINS...WITH
DEEP SURFACE LOW DEVELOPMENT DEPICTED ACROSS EAST TEXAS OR THE GULF
COAST FRIDAY. UPPER TROUGH THEN LIFTS NORTHEAST FRIDAY NIGHT AND
SATURDAY AND TAKES ON A SOMEWHAT NEGATIVE-TILT...WITH THE SURFACE
LOW DEEPENING AND ALSO MOVING EAST-NORTHEAST. CONSIDERABLE SPREAD IS
NOTED IN THE GUIDANCE LOW TRACKS BY THIS TIME...WITH THE ECMWF
FAVORING A MORE SOUTHERN ROUTE ACROSS THE SOUTHEAST AND TO THE
MID-ATLANTIC COAST BY SATURDAY NIGHT. THE 12Z PARALLEL 13 KM GFS
ALSO TAKES THE LOW SIMILARLY TO THE CAROLINA COAST...WHILE THE
CURRENT OPERATIONAL GFS AND A FEW GEFS ENSEMBLE TAKE THE LOW
NORTHEAST ACROSS LAKE ERIE AND LAKE ONTARIO BY SUNDAY MORNING. THIS
WOULD OBVIOUSLY HAVE IMPLICATIONS ON THE NORTHERN EXTENT OF THE
SYSTEM PRECIP SHIELD...WITH THE SOUTHERN TRACK LIKELY NOT BRINGING
PRECIP INTO THE AREA AT ALL...WHILE THE CURRENT OUTLYING NORTHERN
TRACKS COULD BRING MEASURABLE SNOW TO OUR SOUTHERN CWA. FOR DAY 7 AT
THIS GREAT DISTANCE WILL MAINTAIN SLIGHT CHANCE POPS FOR SNOW ACROSS
MAINLY THE SOUTHERN 2/3 OF CWA...BUT EVOLUTION OF NEXT WEEKENDS
SYSTEM WILL UNDOUBTEDLY DIFFER AND WILL HAVE TO BE CONTINUALLY
EVALUATED.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* IFR CIGS AT ORD AND MVFR AT MDW. MVFR VSBY. EXPECT STEADY STATE
THIS AFTERNOON...POSSIBLY SOME DECAY THROUGH THE EARLY
AFTERNOON.
* CIGS/VSBYS POTENTIALLY DROPPING AGAIN TONIGHT.
* SOUTHEAST WINDS TOPPING 10 KT LATER MONDAY MORNING.
KMD
//DISCUSSION...UPDATED 20Z...
UPSTREAM OBS SHOWING VERY LITTLE IMPROVEMTN IN THE COMING
HOURS...THEREFORE EXPECT CIGS AND VSBYS IN THE NEXT FEW HOURS TO
REMAIN THE SAME OR POSSIBLY GET WORSE. THERE COULD BE SOME SLIGHT
IMPROVEMENT LATE AFTERNOON BEFORE THINGS PROGRESS DOWNWARD AGAIN
OVERNIGHT...BUT CONFIDENCE BEYOND THE NEAR TERM ON SPECIFICS IS LOW.
PREVIOUS DISCUSSION...FROM 18Z...
MINIMAL TO VERY SLOW IMPROVEMENT HAS BEEN OCCURRING IN RECENT
HOURS...BUT CONTINUED MOIST ADVECTION INTO THE AREA HAS MAINTAINED
THE STATUS QUO WITH LIFR CEILINGS AND IFR/LIFR VSBYS ...WITH IFR
CIGS CLOSER TO CHICAGO...THEN IN THE IMMEDIATE CHICAGO
AREA...INCLUDING KMDW...DEWPOINT DEPRESSIONS REMAINED HIGHER
THROUGH THE MORNING KEEPING A POCKET OF MIXED MVFR/VFR CIGS CLOSE
TO THE LAKE...THOUGH THERE IS LIKELY SOME HAZE AND BR MIXED IN
BASED ON DOWNTOWN WEBCAMS.
DO STILL SHOW SOME GRADUAL IMPROVEMENT LATER THIS AFTERNOON AS WE
MIX A TOUCH MORE TODAY...BUT LITTLE MORE THAN IFR HAS OCCURRED
UPSTREAM UNTIL YOU GET TO THE CLEARING LINE DRAPING THE IL/MO
BORDER AND ADVANCING NORTHEAST. THEREFORE HAVE TRENDED TOWARD
KEEPING IFR IN MANY SPOTS THIS AFTERNOON WITH THE BEST CHANCE FOR
MVFR CLOSER TO CHICAGO. RUC/HRRR WHICH DO NOT HAVE A SUPERB HANDLE
ON THE CLEARING LINE DO STILL KEEP IT OUT OF THE TERMINALS
TODAY....MAYBE BRINING IT AGAIN INTO THE WESTERN TERMINALS LATE
TONIGHT AS WAS SEEN THIS MORNING AND POSSIBLY CLOSER INTO CHICAGO.
TIMING OF THIS CHALLENGING AND IF IT OCCURS WHAT IMPACTS THAT WILL
HAVE...SO FOR NOW HAVE KEPT THE SAME TRENDS.
OF CONCERN FOR TOMORROW...CIGS MAY LIFT SOME AS MIXING INCREASES
IN THE MORNING...BUT THEN HOLD AT MVFR OR WORSE FOR THE AFTERNOON AS RAIN
MOVES THROUGH. AT THIS TIME WINDS WILL BE OUT OF THE SE AND 10 KT
OR HIGHER.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH IN IFR CIGS FOR ORD...HIGH FOR MVFR AND MEDIUM ON TRENDING
TOWARD IFR THIS AFTERNOON.
* LOW IN CIG/VISBYS TONIGHT.
* MEDIUM-HIGH IN SE WINDS AT OR ABOVE 10 KT TOMORROW LATE MORNING-
AFTERNOON.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...IFR AND RAIN. SOUTH-SOUTHEAST WINDS.
TUESDAY...MVFR WITH IFR POSSIBLE. CHANCE OF RAIN IN THE MORNING
AND CHANCE OF RAIN/SNOW IN THE AFTERNOON. NORTHWEST
WINDS.
WEDNESDAY-THURSDAY...VFR LIKELY. NORTHWEST WINDS.
FRIDAY...MVFR POSSIBLE. NORTHEAST WINDS.
FRIDAY NIGHT-SATURDAY...MVFR POSSIBLE. SLGT CHANCE OF SNOW. NORTHEAST
WINDS.
MTF
&&
.MARINE...
207 PM CST
FEW CONCERNS IN THE IMMEDIATE NEAR TERM...AS WINDS ACROSS LAKE
MICHIGAN ARE GENERALLY SOUTH LESS THAN 20 KT THIS AFTERNOON. THIS
WILL CHANGE OVER THE NEXT 24-36 HOURS...AS AN AREA OF LOW PRESSURE
OVER THE OKLAHOMA PANHANDLE LIFTS SLOWLY NORTHEAST INTO MISSOURI ON
MONDAY...AND ACROSS THE FAR SOUTH END OF LAKE MICHIGAN LATE MONDAY
NIGHT INTO EARLY TUESDAY MORNING. AS THE LOW APPROACHES MONDAY...
SOUTH WINDS WILL INCREASE INTO THE 20-25 KT RANGE PARTICULARLY ON
THE SOUTHERN HALF OR SO OF THE LAKE...BEFORE TURNING NORTH-NORTHWEST
AND INCREASING TO 30 KT ON TUESDAY AS THE LOW PULLS AWAY TO THE EAST
AND COLDER AIR SPREADS INTO THE REGION. WHILE THE LOW MOVES AWAY AND
WINDS BEGIN TO DECREASE SLIGHTLY...A SURFACE TROUGH WILL LINGER
ACROSS THE WESTERN LAKES AND UPPER MIDWEST WHICH WILL MAINTAIN A
FAIRLY TIGHT NORTHWESTERLY GRADIENT AND WILL HELP KEEP WINDS GUSTY
ABOVE 20 KTS THROUGH WEDNESDAY. NORTHWEST WINDS WILL THEN DIMINISH
MORE NOTICEABLY DURING THE LATER PART OF THE WEEK...WITH HIGH
PRESSURE EVENTUALLY BUILDING INTO THE AREA FRIDAY. LONGER RANGE
MODEL FORECASTS INDICATE ANOTHER DEEP LOW PRESSURE SYSTEM MAY PASS
SOUTH OF THE LAKES NEXT WEEKEND.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
242 PM CST Sun Dec 14 2014
.SHORT TERM...(Tonight)
ISSUED AT 225 PM CST SUN DEC 14 2014
20z/2pm visible satellite imagery continues to show low clouds
blanketing much of central Illinois, with the exception being the
far southwest KILX CWA around Winchester. Large area of clearing
that developed over central/eastern Missouri earlier in the day has
worked its way northeastward and now extends along/southwest of a
Winchester to Mount Vernon line. Clearing has behaved much like the
HRRR has predicted, generally reaching the far SW CWA then coming to
a halt. Will continue to carefully monitor satellite trends to see
if clearing can make it any further northeast, but with the sun
going down soon, this does not seem likely. As a result, will
feature mostly clear skies across the far SW into the early evening
followed by a return to overcast conditions across the board.
Visibilities will be a big concern tonight, as current obs show some
sites already dropping into the 1-2 mile range. HRRR has
consistently shown visbys dropping below 1 mile by 00z, with patchy
dense fog possible after dark. Confidence is not great enough for
another Dense Fog Advisory at this time, but the potential certainly
exists as low-level moisture continues to increase and surface
dewpoints approach the 50 degree mark. Due to the clouds/fog,
overnight low temperatures will be several degrees above numeric
guidance in the middle to upper 40s. Vigorous upper-level low noted
on latest water vapor imagery over the Texas panhandle will begin to
lift northeastward tonight, with model consensus spreading showers
into the SW CWA after 3am, then to the I-55 corridor by 6am. Further
northeast, dry conditions will prevail across the E/NE CWA until
after dawn Monday morning.
&&
.LONG TERM...(Monday through Sunday)
ISSUED AT 225 PM CST SUN DEC 14 2014
Models in good agreement with the upper low pushing northeast into
Iowa by Monday afternoon with strong 850 mb theta-e advection/convergence
pointed right into west central Illinois in the 09z-12z time frame.
Highest POPs will be over west central Illinois during that time period
with a progressive shift east with the categorical POPs as the morning
wears on. May have some thunder in the precip band associated with
the warm conveyor belt in the morning, but mid level lapse rates really
don`t ramp up until the afternoon hours as the closed system at 500
mb approaches. Then it appears the better threat for thunder will be
over west central Illinois tomorrow afternoon which will be closest
to the closed 500 mb low. High resolution reflectivity simulations
suggest a band of showers sweeping across the area in the morning,
with a break late morning into the early afternoon hours, before
more showers push across the area as the upper low and deeper forcing
approaches. Will keep likely POPs going across the northern third
of the forecast area tomorrow evening, close to the track of the upper
wave, with POPs starting to decrease late Monday night into Tuesday
from southwest to northeast. The system should continue to push away
from our area on Tuesday with lingering POPs only in the far north
and east during the morning with colder air filtering into our area
as the surface low pushes into lower Michigan by late Tuesday afternoon.
The upper wave will merge with a northern stream shortwave with the
system slowly pulling off to our east thru the end of the week. High
pressure at the surface will shift slowly southeast across the northern
Plains while another piece of energy translates east across the
southern Plains late Wednesday into Thursday with its precipitation
shield possibly affecting southern Illinois during the day Thursday
into Thursday night. Still seeing varying solutions with the initial
wave coming out of the southwest and into the lower Mississippi
Valley late Wed thru late Thursday with the higher POPs continuing
over our far southern counties. Having a hard time seeing precip shift
too far north into a more confluent flow over the southern Great Lakes
with surface high pressure holding firm over the upper Midwest.
A second and stronger wave is then forecast to eject east and then
northeast across Texas on Friday with a large area of rain to its north.
The latest ECMWF, GEM global and UK models were more suppressed with
the low level baroclinic zone/frontal boundary, and as a result, are
more suppressed with the track of the surface low than the current
operational GFS. However, the high resolution GFS (not yet ready for
prime time model) suggests a more suppressed track as well with the
system late in the week. So will go with the consensus for the late
week system and keep any likely or higher POPs to our south late
Friday thru Saturday. The threat for precip will shift well off to
our east on Sunday as the storm system skirts around our area and
then heads up the East Coast later Saturday into Sunday while high
pressure settles into our area for Sunday.
After the unseasonably mild temperatures on Monday, colder temperatures
will filter back into the region starting on Tuesday and remain with
us through the rest of the period. We should see temperatures gradually
return closer to seasonal levels for the middle of December Tuesday
night and hold over the region thru the period.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 1139 AM CST SUN DEC 14 2014
IFR conditions will prevail through the entire 18z TAF period. Low
clouds/fog currently blanket central Illinois, although visbys are
slowly improving. Will continue to monitor a large break in the
overcast across eastern Missouri that is lifting northeastward and
may reach the SW KILX CWA early this afternoon. Latest run of the
HRRR, as well as the 12z NAM keep the clearing well southwest of
the TAF sites, so have gone with a persistence forecast of
continued IFR ceilings. Visbys will improve to between 3 and 5sm
for a period this afternoon: however, all signs are pointing to
re-development of the fog tonight. Have dropped visbys back down
to around 1sm after 00z accordingly. Next storm system is still
slated to arrive later tonight into Monday morning. Based on
NAM/GFS, have introduced rain and an improvement in visbys by 11z
at KSPI, then further east to KCMI after 14z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Smith
AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1206 PM CST SUN DEC 14 2014
.SHORT TERM...
TODAY THROUGH MONDAY NIGHT...
333 AM...FORECAST CONCERNS INCLUDE FOG THIS MORNING AND TONIGHT...
HIGH TEMPS TODAY AND MONDAY AND THEN RAIN MONDAY ALONG WITH THE
CHANCE OF THUNDER.
A BREAK IN THE CLOUDS THAT MOVED INTO WESTERN AND NORTHWEST IL A
FEW HOURS AGO IS QUICKLY SHRINKING AS IS ANOTHER BREAK ACROSS MO.
THUS...NOT MUCH CONFIDENCE TO STRAY FROM CLOUDY MENTION OVER THE
NEXT 48 HOURS WITH ANY BREAKS LIKELY BEING TOO SHORT-LIVED TO TRY
TO INCLUDE IN THE FORECAST. THIS BREAK DID ALLOW SOME RADIATIONAL
COOLING WITH TEMPS DIPPING INTO THE MID/UPPER 30S ACROSS THE FAR
WESTERN CWA WHICH AIDED SOME LOCALLY DENSE FOG. WITH CLOUDS
FILLING BACK IN AND TEMPS IN THESE AREAS SLOWLY WARMING...NOT
EXPECTING ANY WIDESPREAD DENSE FOG THIS MORNING BUT AREAS ALONG
THE WI BORDER BACK INTO FAR NORTHWEST IL WILL LIKELY SEE REDUCED
VISIBILITIES THROUGH MIDDAY.
HAD BEEN CARRYING DRIZZLE IN THE FORECAST THROUGH THIS MORNING
BUT LITTLE IN THE WAY OF OBSERVATIONS OF DRIZZLE AND CONFIDENCE
REGARDING ANY WIDESPREAD DRIZZLE DEVELOPING IS LOW ENOUGH TO
REMOVE IT.
WHERE CLOUDS HAVE REMAINED OVC...TEMPS HAVE REMAINED GENERALLY IN
THE MID 40S...THOUGH MAY DIP INTO THE LOWER 40S BY MORNING. EVEN
WITH THESE LOWS...HIGHS TODAY SHOULD BE ABLE TO REACH THE LOWER TO
MID 50S MOST AREAS AND DIDN/T MAKE ANY CHANGES TO THE GOING HIGHS
FOR TODAY.
CONFIDENCE FOR BOTH FOG AND DRIZZLE TONIGHT IS SOMEWHAT LOW.
GUIDANCE CONTINUES TO SUGGEST FOG MAY BECOME DENSE IN SOME AREAS
AND SOME AREAS/PATCHY FOG STILL EXTENDS WILL SOUTH INTO CENTRAL
IL/NORTHERN MO. IF FOG WERE TO BECOME DENSE...THEN THAT WOULD
LIKELY LEAD TO THE POTENTIAL FOR DRIZZLE. FOR NOW HAVE TRENDED A
BIT MORE OPTIMISTIC WITH JUST PATCHY FOG MENTION. LOWS TONIGHT MAY
ALSO BE FOG DEPENDENT...POSSIBLY DROPPING LOWER THAN ADVERTISED
MID 40S IF DENSE FOG DEVELOPS.
BULK OF ANY RAIN SHOULD HOLD OFF UNTIL AFTER DAYBREAK MONDAY
MORNING WITH A LINE/BAND OF SHOWERS MOVING NORTHEAST ACROSS THE
AREA WITH GOOD AGREEMENT FROM THE MODELS. ENOUGH INSTABILITY WITH
THIS THAT A RUMBLE OR TWO OF THUNDER IS POSSIBLE BUT AS IT MAY BE
IN A DECAYING STAGE AS IT ARRIVES...NOT CONFIDENT ENOUGH TO
INCLUDE ANY THUNDER MENTION. COULD BE SEVERAL DRY HOURS AHEAD AND
BEHIND THIS BAND UNTIL MORE WIDESPREAD LIGHT RAIN ARRIVES MONDAY
EVENING AS THE SURFACE LOW SLOWLY MOVES ACROSS THE AREA. HIGHS ON
MONDAY IN THE LOWER 50S LOOK REASONABLE AND AGAIN MADE NO CHANGES
HERE. TEMPS THEN SLOWLY FALL THROUGH THE 40S MONDAY NIGHT. CMS
&&
.LONG TERM...
TUESDAY THROUGH SATURDAY...
333 AM...AS THE SURFACE LOW MOVES ACROSS SOUTHERN LOWER MICHIGAN
TUESDAY MORNING...WINDS WILL SHIFT TO THE NORTHWEST AND BECOME
RATHER GUSTY...PERHAPS TO 30 MPH. COLDER AIR WILL SPREAD ACROSS
THE AREA. THIS WILL ALLOW LIGHT RAIN TO MIX WITH AND CHANGE TO
LIGHT SNOW FROM WEST TO EAST DURING THE MORNING INTO THE EARLY
AFTERNOON. FAIRLY LOW CONFIDENCE REGARDING TIMING BUT THE BULK OF
THE QPF SHOULD BE EXITING AS THE TRANSITION OCCURS...SO NOT
EXPECTING ANY ACCUMULATION OF SNOW.
HIGH PRESSURE WILL BUILD ACROSS THE NORTHERN PLAINS TUESDAY AND
WEDNESDAY AND THEN SPREAD INTO THE WESTERN LAKES THURSDAY. THIS
SHOULD PUSH THE THREAT OF ANY PRECIP WITH THE NEXT SYSTEM SOUTH
OF THE CWA THROUGH THURSDAY NIGHT AND LIKELY FRIDAY. BUT AS THIS
LOW LIFTS NORTHEAST ACROSS THE OHIO VALLEY...THE GFS SPREADS THE
PRECIP SHIELD AS FAR NORTH AS NORTHERN IL. IF THIS WERE TO
OCCUR...IT SHOULD BE COLD ENOUGH FOR MAINLY SNOW. BUT ECMWF...
WHICH HAS BEEN MORE CONSISTENT WITH KEEPING THIS TIME PERIOD DRY
ALSO KEEPS THIS PRECIP TO THE SOUTH. MAINTAINED LOW CHANCE POPS
FOR FRIDAY NIGHT BUT THIS WILL LIKELY SEE CHANGES WITH LATER
FORECASTS. OTHERWISE...TEMPS RETURN TO MORE TYPICAL VALUES FOR
MID DECEMBER WITH HIGHS IN THE UPPER 20S/LOWER 30S WEDNESDAY AND
THURSDAY. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* IFR CIGS AT ORD AND MVFR AT MDW. MVFR VSBY. EXPECT STEADY STATE
THIS AFTERNOON...POSSIBLY SOME IMPROVEMENT THROUGH THE EARLY
AFTERNOON.
* CIGS/VSBYS POTENTIALLY DROPPING AGAIN TONIGHT.
* SOUTHEAST WINDS TOPPING 10 KT LATER MONDAY MORNING.
KMD
//DISCUSSION...UPDATED 18Z...
MINIMAL TO VERY SLOW IMPROVEMENT HAS BEEN OCCURRING IN RECENT
HOURS...BUT CONTINUED MOIST ADVECTION INTO THE AREA HAS MAINTAINED
THE STATUS QUO WITH LIFR CEILINGS AND IFR/LIFR VSBYS ...WITH IFR
CIGS CLOSER TO CHICAGO...THEN IN THE IMMEDIATE CHICAGO
AREA...INCLUDING KMDW...DEWPOINT DEPRESSIONS REMAINED HIGHER
THROUGH THE MORNING KEEPING A POCKET OF MIXED MVFR/VFR CIGS CLOSE
TO THE LAKE...THOUGH THERE IS LIKELY SOME HAZE AND BR MIXED IN
BASED ON DOWNTOWN WEBCAMS.
DO STILL SHOW SOME GRADUAL IMPROVEMENT LATER THIS AFTERNOON AS WE
MIX A TOUCH MORE TODAY...BUT LITTLE MORE THAN IFR HAS OCCURRED
UPSTREAM UNTIL YOU GET TO THE CLEARING LINE DRAPING THE IL/MO
BORDER AND ADVANCING NORTHEAST. THEREFORE HAVE TRENDED TOWARD
KEEPING IFR IN MANY SPOTS THIS AFTERNOON WITH THE BEST CHANCE FOR
MVFR CLOSER TO CHICAGO. RUC/HRRR WHICH DO NOT HAVE A SUPERB HANDLE
ON THE CLEARING LINE DO STILL KEEP IT OUT OF THE TERMINALS
TODAY....MAYBE BRINING IT AGAIN INTO THE WESTERN TERMINALS LATE
TONIGHT AS WAS SEEN THIS MORNING AND POSSIBLY CLOSER INTO CHICAGO.
TIMING OF THIS CHALLENGING AND IF IT OCCURS WHAT IMPACTS THAT WILL
HAVE...SO FOR NOW HAVE KEPT THE SAME TRENDS.
OF CONCERN FOR TOMORROW...CIGS MAY LIFT SOME AS MIXING INCREASES
IN THE MORNING...BUT THEN HOLD AT MVFR OR WORSE FOR THE AFTERNOON AS RAIN
MOVES THROUGH. AT THIS TIME WINDS WILL BE OUT OF THE SE AND 10 KT
OR HIGHER.
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH IN IFR CIGS FOR ORD...HIGH FOR MVFR FOR MDW THOUGH LOW ON
IF IFR RETURNS THIS AFTERNOON. MEDIUM- HIGH IN HOLDING STEADY
STATE FOR THE AFTERNOON THEN DROPPING SOME TONIGHT.
* LOW IN CIG/VISBYS TONIGHT AND IF ANY CLEARING WILL OCCUR.
* MEDIUM-HIGH IN SE WINDS AT OR ABOVE 10 KT TOMORROW LATE MORNING-
AFTERNOON.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...IFR AND RAIN. SOUTH-SOUTHEAST WINDS.
TUESDAY...MVFR WITH IFR POSSIBLE. CHANCE OF RAIN IN THE MORNING
AND CHANCE OF RAIN/SNOW IN THE AFTERNOON. NORTHWEST
WINDS.
WEDNESDAY-THURSDAY...VFR LIKELY. NORTHWEST WINDS.
FRIDAY...MVFR POSSIBLE. NORTHEAST WINDS.
FRIDAY NIGHT-SATURDAY...MVFR POSSIBLE. SLGT CHANCE OF SNOW. NORTHEAST
WINDS.
MTF
&&
.MARINE...
159 AM CST
FAIRLY STAGNANT CONDITIONS OVER THE LAKE WILL CONTINUE TODAY AND
TONIGHT BEFORE APPROACHING LOW PRESSURE WILL BRING A CHANGE. IN
ADVANCE OF THIS LOW...MOISTURE WILL EASE NORTHWARD OVER THE LAKE
TODAY. THIS IS EXPECTED TO MAKE FOG BOTH MORE WIDESPREAD AND THICK
AND IT IS POSSIBLE A MARINE FOG ADVISORY WILL BE NEEDED. WINDS WILL
ALSO TURN MORE SOUTHERLY BY TONIGHT AND INCREASE IN SPEED MONDAY IN
ADVANCE OF THE LOW. STABLE CONDITIONS IMMEDIATELY ALOFT WILL KEEP
GUSTINESS TEMPERED WITH THESE SOUTHERLY WINDS. HOWEVER ONCE THE LOW
PASSES OVER THE SOUTHERN PART OF THE LAKE...THE COLD AIR ADVECTION
SHOULD DRIVE FAIRLY STOUT WINDS...WITH NORTHWEST WINDS OF 30 KT
CONTINUING TO BE LIKELY BY LATE TUESDAY MORNING THROUGH TUESDAY
NIGHT. NOT PARTICULARLY COLD AIR AT ALL FOR MID-DECEMBER WILL MOVE
IN ON THOSE WINDS...SO NOT EXPECTING ANY FREEZING SPRAY.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1139 AM CST Sun Dec 14 2014
.UPDATE...
ISSUED AT 1045 AM CST SUN DEC 14 2014
16z/10am observations show visibilities gradually improving across
much of central and southeast Illinois, with dense fog now confined
to locations along/south of I-70 and from Peoria eastward to
Bloomington. Trends suggest visbys will improve enough across the
board to allow the Dense Fog Advisory to expire at 11am. Areas of
fog will likely persist into the afternoon as low-level moisture
continues to increase and surface dewpoints rise through the 40s.
Latest visible satellite imagery shows a large area of clearing
upstream across central/eastern Missouri that is slowly working
its way eastward toward the Mississippi River. Timing tools show
clearing reaching the far SW KILX CWA around Winchester by midday.
Big question will be how much further north and east the clearing
can reach, as the HRRR insists it will grind to a halt near
Jacksonville. Updated sky grids to feature partial clearing across
the far SW CWA by early afternoon, but have kept overcast
conditions in place across the remainder of the area. Made a few
minor adjustments to afternoon highs as well, with readings
ranging from the lower 50s near the Indiana border to the upper
50s west of Jacksonville where a little sunshine is likely.
&&
.SHORT TERM...(Today)
ISSUED AT 300 AM CST SUN DEC 14 2014
The deep low pressure trough currently over the Southwest will
approach Illinois today promoting enhanced southerly return flow as
the persistent high pressure ridge over the Midwest shifts eastward.
Observations and satellite imagery upstream of Illinois in this
pattern indicate pervasive cloud cover with just a few breaks
possible, but for the most part another cloudy day is in store.
Model soundings are consistent with this idea, keeping low levels
very saturated. An increase in southerly winds to around 10 mph is
on track as well. Temperatures will rise several degrees, with highs
reaching well into the 50s across central IL. Any lift remains weak
today, so precip chances are negligible, with only a little drizzle
possible in patchy of fog through noon.
&&
.LONG TERM...(Tonight through Saturday)
ISSUED AT 300 AM CST SUN DEC 14 2014
Deep upper trough across the Rockies starting to show signs of a
circulation in the south end across New Mexico. Evening model suite
continues to swing this upper low up into the central Plains by
Monday morning, and eastward into northern Illinois by evening. Have
made some adjustments to the timing of the rain overnight, with the
higher resolution model guidance bringing it into the western third
of the CWA after 3 am. General model consensus showing high PoP`s
Monday morning but only in about a 3-4 hour time frame at any
given location, with a relatively narrow band of showers advancing
east to near the Indiana border by midday. Would not rule out a
rumble or two of thunder with this band. Bit of a dry slot tries
to work its way in behind this line, but will have increasing
PoP`s again across the northwest during the afternoon with the
proximity of the surface low, which should be in southeast Iowa by
late afternoon. Have kept some 60% PoP`s going north of I-74 into
Monday night as the low moves northeast.
Core of the cooler air will begin moving in on Tuesday, and surface
temperatures look to move little during the day. This marks the
start of a period of temperatures near or slightly below normal,
which will persist into the weekend.
Still some challenges in the longer range in regards to the
potential late week storm system. Some broad scale agreement is
found amongst the GFS and ECMWF models through Friday, with
development of a storm system across the southern Plains as an upper
trough advances east out the Desert Southwest. A fair amount of dry
northeast flow will be persisting around a high over the northwest
Great Lakes. Forecast soundings showing only a brief period of ice
crystals aloft before being lost by the time the lower levels
finally saturate. The GFS is now largely keeping the precipitation
to our south until Friday, with the track of the surface low over
the Tennessee Valley supportive of some accumulating deformation
zone snow. The ECMWF tries to bring a bit in of precipitation on
Thursday and keeps the late week system still across the lower
Mississippi Valley, with mainly areas south of I-70 threatened on
Saturday. The forecast grids start with a blend of the two and limit
the PoP`s on Friday to the southwest CWA, becoming more widespread
Friday night and then leaning toward the ECMWF solution for
Saturday. Confidence is not very high yet, as ensembles are showing
a fair amount of spread at that range.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 1139 AM CST SUN DEC 14 2014
IFR conditions will prevail through the entire 18z TAF period. Low
clouds/fog currently blanket central Illinois, although visbys are
slowly improving. Will continue to monitor a large break in the
overcast across eastern Missouri that is lifting northeastward and
may reach the SW KILX CWA early this afternoon. Latest run of the
HRRR, as well as the 12z NAM keep the clearing well southwest of
the TAF sites, so have gone with a persistence forecast of
continued IFR ceilings. Visbys will improve to between 3 and 5sm
for a period this afternoon: however, all signs are pointing to
re-development of the fog tonight. Have dropped visbys back down
to around 1sm after 00z accordingly. Next storm system is still
slated to arrive later tonight into Monday morning. Based on
NAM/GFS, have introduced rain and an improvement in visbys by 11z
at KSPI, then further east to KCMI after 14z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Barnes
SHORT TERM...Onton
LONG TERM...Geelhart
AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS TOPEKA KS
523 PM CST Mon Dec 15 2014
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Tuesday)
Issued at 314 PM CST MON DEC 15 2014
Stacked system was centered in northern Missouri early this
afternoon with west to northwest winds bringing cold air in behind
and surface temps 5 to 15F below those of the pre- dawn hours.
Area of precipitation in deformation band on immediate west to
north flank of the system has weakened and exited, but water vapor
imagery supports RAP analysis of a minor wave rotating south into
south central Nebraska with narrow band of cloud top cooling and
light snow reported at CNK.
Recent HRRR and RAP output shows a steady decline in precip this
evening as the system enter the Ohio Valley overnight and this seems
very reasonable with heights rising and steady drying aloft. The
latter brings at least minor difficulty in precip type, but in this
band expect RH deep enough into the ice crystal formation layer for
rain and snow to dominate. Any accumulations should be quite light
and localized. Low cloud looks to be rather persistent tonight into
early Tuesday however with temps in this layer approaching -10C for
flurry possibilities but moisture depth shouldn`t support more than
brief bouts at best. Continued drying should bring some sunshine to
much of Tuesday, but high cloud entering the Rockies just upstream
of the upper ridge axis should increase toward sunset. Went a bit
above MOS averages on low temps tonight with the cloud in place.
.LONG TERM...(Tuesday Night through Monday)
Issued at 314 PM CST MON DEC 15 2014
Shortwave ridging and a dry airmass is expected to keep the
weather quiet for Tuesday night through Wednesday morning. With
some weak cold air advection as high pressure builds in, lows
Wednesday morning are expected to be around 20. Moisture appears
to begin returning north Wednesday. However models show the
shallow cold air holding in place Wednesday, keeping an easterly
surface winds and not mixing the boundary layer very deeply.
Therefore highs are forecast to remain in the middle 30s because
of this as well as increasing cloud cover.
Wednesday night and Thursday continue to look a little tricky with
regard to precip type. Models continue to show a perturbation
moving across the area Wednesday evening and a second one Thursday
morning. The better Q vector convergence and vorticity advection
may pass over southeast KS and the NAM and GFS forecast soundings
suggest there may not be enough saturation in the mid levels for
precip to be all snow. The one solution that continues to produce
a fair amount of QPF (around 2 tenths) Wednesday night is the
ECMWF, but it is difficult to know if there is as much dry air at
mid levels in its solution due to less vertical resolution. In all
it appears there is the potential for a weak progressive wave with
modest vertical motion to affect parts of the area with light
precipitation and have maintained POPs in the 30 to 40 percent
range. Best chances for measurable precip would be across east
central KS where the forcing is likely to be a little stronger.
Given the uncertainty provided by the NAM and GFS forecast
soundings, have introduced some freezing drizzle to the forecast
thinking mid levels may not be saturated and there would be no ice
in the cloud. Right now I would expect a light precip event
possibly affecting motorists late Wednesday night and Thursday
morning.
For Thursday night through Friday night, models seem to be
converging on a southern solution with the upper level jet
remaining over the southern U.S. and a developing surface low
tracking along the gulf coast. Even the 12Z GFS has trended
further south. Because of this, have trended POPS down a little
more for the period. Considered removing them all together but the
GFS still tries to bring energy down from the northwest and kicks
out some light QPF. Therefore held onto some slight chances for
precip.
Temps do not appear to be trending warmer until maybe Monday as
models hang onto the shallow cold airmass through much of the
weekend. By Monday there are signs that some low level return flow
could develop helping to bring some warm air back north. As for
the weather, the models continue to try and figure out this
pattern with split flow and energy coming off the Pacific. With
no obvious forcing progged to affect the forecast area through
Monday, have continued with a dry forecast for the weekend and
into next week.
&&
.AVIATION...(For the 00Z TAFs through 00Z Tuesday Evening)
Issued at 519 PM CST MON DEC 15 2014
The current light rain and snow will continue to move eastward and
should exit the taf sites around 00Z. There is a slight chance
very light rain or snow lingers for a brief period beyond 00Z.
Ceilings are forecast to stay mainly MVFR through the overnight
hours.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...65
LONG TERM...Wolters
AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS GOODLAND KS
246 PM MST SUN DEC 14 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 131 PM MST SUN DEC 14 2014
LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW A STRONG UPPER
LOW CENTERED OVER THE OK PANHANDLE. A DRY SLOT THAT DEVELOPED OVER
THE SOUTHERN PLAINS IS BEGINNING TO TRANSLATE NORTH AND WRAP INTO
THE UPPER LOW CENTER WITH A MOIST PLUME THAT HAS BEEN FEEDING
MODERATE TO HEAVY RAIN OVER OUR CWA. AT THE SURFACE A SLOW MOVING
COLD FRONT CURRENTLY EXTENDS FROM NORTH CENTRAL NEBRASKA TO NEAR
GOODLAND AND INTO SOUTHEAST COLORADO. BEHIND THIS FRONT
PRECIPITATION IS TRANSITIONING OVER TO SNOW.
A CONCERN WITH THIS UPDATE CYCLE WILL BE THE IMPACT OF THE DRY
SLOT ON PRECIPITATION AS THIS APPEARED TO BE MUCH MORE EXTENDING
AND ON TRACK TO OVERSPREAD THE EASTERN 2/3 OF THE FORECAST AREA.
GUIDANCE IS STILL SHOWING A DEFORMATION BAND FORMING ALONG AN
ELEVATED FRONTAL ZONE JUST NORTHWEST OF THE H7 LOW...HOWEVER THIS
MAY BE CUTOFF FROM THE BEST MOISTURE ADVECTION. RAP APPEARS TO
HAVE A SLIGHTLY BETTER HANDLE ON THIS AND SHOWS A THE SNOW BAND THIS
EVENING OVER EASTERN COLORADO BARELY PROGRESSING INTO NW KANSAS
AND OUR SW NEBRASKA COUNTIES. SNOW WILL QUICKLY TRANSITION
NORTHWARD AFTER MIDNIGHT...WITH LIGHT SNOW POSSIBLY LINGERING OVER
SW NEBRASKA INTO MONDAY AFTERNOON. RESULT OF THESE CHANGES IS
MUCH LESS SNOW ACROSS THE EASTERN 2/3 OF THE CWA THAN PREVIOUSLY
ANTICIPATED. IT DOES STILL APPEAR THAT THE HEAVIER SNOW PREVIOUSLY
ADVERTISED IN YUMA COLORADO COULD STILL MATERIALIZE...BUT OVERALL
I TRENDED OUR SNOW FORECAST BACK.
I DO NOT PLAN ON CHANGING OR REMOVING ANY HIGHLIGHTS...AS I AM
STILL CONCERNED ABOUT POSSIBLE BLOWING SNOW WITH THIS BAND AS IT
MOVES EAST AND WINDS GUST TO 45 MPH TONIGHT AND MONDAY. IF WE SEE
HEAVIER RATES (ESPECIALLY IN DUNDY...YUMA...AND POSSIBLY KIT
CARSON COUNTIES) WE COULD STILL SEE NEAR BLIZZARD OR EVEN
BLIZZARD CONDITIONS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 246 PM MST SUN DEC 14 2014
THE MAIN STORIES IN THIS EXTENDED FORECAST PERIOD ARE CHANCES FOR
LIGHT SNOW WEDNESDAY EVENING THROUGH FRIDAY AND BELOW TO NEAR NORMAL
TEMPERATURES. NO MAJOR DEVIATIONS FROM PREVIOUS FORECAST WERE MADE
AS ATTENTION WAS FOCUSED ON TODAYS SYSTEM IMPACTING THE REGION.
FOR TOMORROW NIGHT THROUGH WEDNESDAY...PRECIPITATION-FREE WEATHER IS
FORECAST AS SURFACE HIGH PRESSURE SETTLES OVER THE HIGH PLAINS.
PERIODS OF UPPER LEVEL CLOUD COVER ARE ANTICIPATED AS A WEAK UPPER
LEVEL DISTURBANCE PASSES THROUGH. TEMPERATURES WILL BE A FEW DEGREES
BELOW NORMAL DURING THIS PERIOD. SOUTH WINDS RETURN TUESDAY BEHIND
THE HIGH PRESSURE CENTER...ALLOWING SOME SLIGHTLY WARMER AIR TO MOVE
IN FOR WEDNESDAY.
AN UPPER LEVEL DISTURBANCE DIGS INTO THE SOUTHWESTERN UNITED STATES
WEDNESDAY AND EJECTS OVER THE SOUTHERN PLAINS THURSDAY INTO FRIDAY.
A LEAD SHORTWAVE MOVES THROUGH WEDNESDAY NIGHT. THIS SHORTWAVE...IN
CONJUNCTION WITH WEAK ISENTROPIC LIFT...SHOULD PROVIDE ENOUGH LIFT
FOR LIGHT PRECIPITATION TO DEVELOP. DID NOT DEVIATE FROM SUPERBLEND
POPS AS FORECAST GUIDANCE IS NOT IN STRONG AGREEMENT WITH RESPECT TO
THIS LEAD SHORTWAVE. LIGHT SNOW AMOUNTS ARE FORECAST BUT WIDESPREAD
SIGNIFICANT IMPACTS ARE ADVERTISED.
LIGHT SNOW CHANCES CONTINUE THROUGH FRIDAY AS THE MAIN DISTURBANCE
PASSES TO THE SOUTH. THERE REMAIN LARGE DIFFERENCES BETWEEN MODELS
AND THEIR PREVIOUS RUNS ON THE EVOLUTION OF THIS SYSTEM. MAINTAINED
SUPERBLEND POPS BUT CONFIDENCE IS QUITE LOW WITH REGARDS TO THIS
TIME FRAME. IF THIS SYSTEM GOES FURTHER SOUTH AS THE EUROPEAN AND
CANADIAN MODELS DISPLAY...THE REGION MAY MISS THE PRECIPITATION ALL
TOGETHER. THE GFS MODEL IS THE ONLY SOLUTION THAT CURRENTLY BRINGS
THIS DISTURBANCE FURTHER NORTH...ALLOWING PRECIPITATION DEVELOPMENT
OVER MAINLY NORTHWEST KANSAS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1032 AM MST SUN DEC 14 2014
COMPLICATED TAFS AS STRONG UPPER LOW WILL CONTINUE TO IMPACT
FLIGHT CONDITIONS OVER BOTH KGLD AND KMCK. MODERATE TO HEAVY RAIN
AND ISOLATED THUNDERSTORMS WILL IMPACT BOTH TERMINALS THIS
AFTERNOON WITH A TRANSITION TO SNOW AND BLOWING SNOW THIS EVENING.
IFR/MVFR FLIGHT CONDITIONS WILL TRANSITION TO LIFR/VLIFR THIS
EVENING AND OVERNIGHT...WITH SNOW AND BLOWING SNOW IMPACTING KGLD
FIRST (AROUND 00Z) AND KMCK LATER (AFTER 06Z). WINDS GUSTING
30-35KT ARE EXPECTED TONIGHT THROUGH MIDDAY MONDAY. WHILE
CONDITIONS WILL IMPROVE 10-13Z TIME FRAME...I AM MOST CONFIDENT
IN PREVAILING VFR AT KGLD AFTER 12Z. SNOW AND BLOWING SNOW MAY
LINGER AT KMCK THROUGH MIDDAY MONDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY UNTIL 8 AM MST /9 AM CST/ MONDAY FOR
KSZ001-002-013.
CO...WINTER WEATHER ADVISORY UNTIL 8 AM MST MONDAY FOR COZ091.
WINTER STORM WARNING UNTIL 8 AM MST MONDAY FOR COZ090.
NE...WINTER WEATHER ADVISORY UNTIL 9 AM CST MONDAY FOR NEZ080-081.
WINTER STORM WARNING UNTIL 8 AM MST MONDAY FOR NEZ079.
&&
$$
SHORT TERM...DR
LONG TERM...RRH
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
132 PM MST SUN DEC 14 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 131 PM MST SUN DEC 14 2014
LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW A STRONG UPPER
LOW CENTERED OVER THE OK PANHANDLE. A DRY SLOT THAT DEVELOPED OVER
THE SOUTHERN PLAINS IS BEGINNING TO TRANSLATE NORTH AND WRAP INTO
THE UPPER LOW CENTER WITH A MOIST PLUME THAT HAS BEEN FEEDING
MODERATE TO HEAVY RAIN OVER OUR CWA. AT THE SURFACE A SLOW MOVING
COLD FRONT CURRENTLY EXTENDS FROM NORTH CENTRAL NEBRASKA TO NEAR
GOODLAND AND INTO SOUTHEAST COLORADO. BEHIND THIS FRONT
PRECIPITATION IS TRANSITIONING OVER TO SNOW.
A CONCERN WITH THIS UPDATE CYCLE WILL BE THE IMPACT OF THE DRY
SLOT ON PRECIPITATION AS THIS APPEARED TO BE MUCH MORE EXTENDING
AND ON TRACK TO OVERSPREAD THE EASTERN 2/3 OF THE FORECAST AREA.
GUIDANCE IS STILL SHOWING A DEFORMATION BAND FORMING ALONG AN
ELEVATED FRONTAL ZONE JUST NORTHWEST OF THE H7 LOW...HOWEVER THIS
MAY BE CUTOFF FROM THE BEST MOISTURE ADVECTION. RAP APPEARS TO
HAVE A SLIGHTLY BETTER HANDLE ON THIS AND SHOWS A THE SNOW BAND THIS
EVENING OVER EASTERN COLORADO BARELY PROGRESSING INTO NW KANSAS
AND OUR SW NEBRASKA COUNTIES. SNOW WILL QUICKLY TRANSITION
NORTHWARD AFTER MIDNIGHT...WITH LIGHT SNOW POSSIBLY LINGERING OVER
SW NEBRASKA INTO MONDAY AFTERNOON. RESULT OF THESE CHANGES IS
MUCH LESS SNOW ACROSS THE EASTERN 2/3 OF THE CWA THAN PREVIOUSLY
ANTICIPATED. IT DOES STILL APPEAR THAT THE HEAVIER SNOW PREVIOUSLY
ADVERTISED IN YUMA COLORADO COULD STILL MATERIALIZE...BUT OVERALL
I TRENDED OUR SNOW FORECAST BACK.
I DO NOT PLAN ON CHANGING OR REMOVING ANY HIGHLIGHTS...AS I AM
STILL CONCERNED ABOUT POSSIBLE BLOWING SNOW WITH THIS BAND AS IT
MOVES EAST AND WINDS GUST TO 45 MPH TONIGHT AND MONDAY. IF WE SEE
HEAVIER RATES (ESPECIALLY IN DUNDY...YUMA...AND POSSIBLY KIT
CARSON COUNTIES) WE COULD STILL SEE NEAR BLIZZARD OR EVEN
BLIZZARD CONDITIONS.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 500 AM MST SUN DEC 14 2014
THE WEDNESDAY THROUGH FRIDAY PERIOD WILL BE NEAR NORMAL
TEMPERATURES AS THE JET STREAM REMAINS SOUTH OF THE AREA. MODELS
HAVE ALMOST DISSOLVED THE PRESENCE OF THE SHORT WAVE TROUGH ON
WEDNESDAY THAT WAS AHEAD OF THE STRONGER TROUGH DEEPENING OVER THE
WEST COAST...SO WILL NOT HAVE ANY SNOWFALL CHANCES FOR WEDNESDAY.
SNOWFALL CHANCES RETURN TO THE FORECAST WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT AS THE UPPER LEVEL LONG WAVE TROUGH OVER THE WEST
COAST MOVES EAST OVER THE DESERT SOUTHWEST TOWARD THE AREA. WITH
THE MAJORITY OF THE UPPER LEVEL DYNAMICS SOUTH OF THE
AREA...SNOWFALL AMOUNTS WILL BE UNDER 3 INCHES AT THIS TIME...WITH
THE HIGHER SNOWFALL AMOUNTS TRENDING FROM WEST TO EAST. HAVE
NOTICED OVER THE LAST COUPLE OF NIGHTS THE MODELS HAVE BEGUN NUDGING
THE LONG WAVE TROUGH NORTHWARD AS IT LIFTS NORTHEAST OVER THE
PLAINS...BRINGING THE UPPER LEVEL DYNAMICS CLOSER TO THE AREA AND
INCREASING THE POTENTIAL FOR MORE SNOWFALL. BY FRIDAY THE SNOWFALL
WILL COME TO AN END AS THE LONG WAVE TROUGH MOVES EAST OF THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1032 AM MST SUN DEC 14 2014
COMPLICATED TAFS AS STRONG UPPER LOW WILL CONTINUE TO IMPACT
FLIGHT CONDITIONS OVER BOTH KGLD AND KMCK. MODERATE TO HEAVY RAIN
AND ISOLATED THUNDERSTORMS WILL IMPACT BOTH TERMINALS THIS
AFTERNOON WITH A TRANSITION TO SNOW AND BLOWING SNOW THIS EVENING.
IFR/MVFR FLIGHT CONDITIONS WILL TRANSITION TO LIFR/VLIFR THIS
EVENING AND OVERNIGHT...WITH SNOW AND BLOWING SNOW IMPACTING KGLD
FIRST (AROUND 00Z) AND KMCK LATER (AFTER 06Z). WINDS GUSTING
30-35KT ARE EXPECTED TONIGHT THROUGH MIDDAY MONDAY. WHILE
CONDITIONS WILL IMPROVE 10-13Z TIME FRAME...I AM MOST CONFIDENT
IN PREVAILING VFR AT KGLD AFTER 12Z. SNOW AND BLOWING SNOW MAY
LINGER AT KMCK THROUGH MIDDAY MONDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY UNTIL 8 AM MST /9 AM CST/ MONDAY FOR
KSZ001-002-013.
CO...WINTER WEATHER ADVISORY UNTIL 8 AM MST MONDAY FOR COZ091.
WINTER STORM WARNING UNTIL 8 AM MST MONDAY FOR COZ090.
NE...WINTER WEATHER ADVISORY UNTIL 9 AM CST MONDAY FOR NEZ080-081.
WINTER STORM WARNING UNTIL 8 AM MST MONDAY FOR NEZ079.
&&
$$
SHORT TERM...DR
LONG TERM...99
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1033 AM MST SUN DEC 14 2014
.UPDATE...
ISSUED AT 946 AM MST SUN DEC 14 2014
MADE ADJUSTMENTS TO POP/WX/QPF/SNOW TO ACCOUNT FOR CURRENT
COVERAGE AND TIMING OF PRECIP. NEAR FREEZING TO SUB FREEZING
TEMPS WERE REPORTED ACROSS NW PARTS OF THE CWA AS MODERATE RAIN
WAS MOVING NORTH. MELTING LAYER APPEARS TO BE AROUND 3500FT BASED
ON DUAL POL FIELDS...AND RAP GENERALLY KEEPS WARM LAYER ALOFT IN
PLACE INTO THIS AFTERNOON. I WAS CONCERNED THAT AS LONG AS
SURFACE TEMPS WERE BELOW FREEZING WE COULD SEE FREEZING RAIN
ACCUMULATION...BUT SURFACES HAVE BEEN SLOWER TO RESPOND AND AIR
TEMPS ARE NOW MODERATING. I INCLUDED FREEZING RAIN MENTION THIS
MORNING AND ISSUED SPS EARLIER...HOWEVER AT THIS POINT THOUGHT IS
ANY ICING WOULD BE LOCALIZED THIS MORNING...WITH A STRAIGHT RAIN
TO SNOW TRANSITION.
IMPACT OF DRY SLOT MOVING NORTH (APPARENT ON WV IMAGERY) IS A
CONCERN. RAP SEEMS TO HAVE A DECENT HANDLE ON THIS...AND SHOWS
LESS PESSIMISTIC QPF VALUES IN OUR KS COUNTIES AND A SLOWER TIMING
ON SNOW DEVELOPMENT. I MADE SOME ADJUSTMENTS TO TIMING AND
AMOUNTS...BUT HELD OFF MAJOR OVERHAUL AS AREAS IN ADVISORY STILL
APPEAR TO SEE FAVORABLE RATES THIS EVENING OVERNIGHT. NOT
PLANNING ON CHANGING HAZARDS THIS MORNING...BUT WILL NEED TO
MONITOR.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 500 AM MST SUN DEC 14 2014
TODAY-TONIGHT...POTENT CLOSED LOW JUST STARTING TO DEVELOP OVER
NEW MEXICO AT THE BASE OF UPPER TROUGH THIS MORNING. THUNDERSTORMS
HAVE BROKEN OUT AHEAD OF THIS FEATURE AND ARE PUSHING INTO
SOUTHEAST COLORADO RIGHT NOW. BY 18Z THE LOW IS FORECAST TO REACH
SOUTHEAST COLORADO/SOUTHWEST KANSAS BORDER THEN OVER GARDEN CITY
BY DARK. AROUND MIDNIGHT THE LOW IS EXPECTED TO BE NEAR PRATT/HAYS
AREA THEN INTO THE TOPEKA AREA BY SUNRISE MONDAY MORNING.
A PLETHORA OF WEATHER POSSIBILITIES EXIST TODAY. RAIN WILL BE THE
INITIAL PRECIP TYPE WITH THUNDERSTORMS POSSIBLE AHEAD OF THE COLD
FRONT/WIND SHIFT. DURING THE LATE AFTERNOON HOURS COLDER AIR MOVES
IN WITH THE FRONT BRINGING A SMALL WINDOW OF SLEET AND MOST LIKELY
SNOW FROM WEST TO EAST. THUNDERSTORMS REMAIN POSSIBLE IN THE
NORTON AND HILL CITY AREAS TIL NEARLY MIDNIGHT.
WITH THE SNOW WILL COME NORTH TO NORTHWEST WINDS GUSTING TO 45
MPH. THIS WILL CREATE REDUCED VISIBILITIES IN SNOW AND BLOWING
SNOW. TOYED WITH A BLIZZARD WARNING FOR YUMA AND DUNDY COUNTIES
WHERE SNOWFALL WILL BE THE HEAVIEST AND GIVEN THE WINDS PRODUCE
VISIBILITIES AROUND 1/2 MILE. HAVE SETTLED ON A WINTER STORM
WARNING FOR YUMA AND DUNDY WHERE UP TO 7 INCHES OF SNOW EXPECTED
ALONG WITH VIS 1/2 MILE OR POSSIBLY LESS. THE ADVISORY AREA ISSUED
YESTERDAY WILL SEE NO CHANGES THIS SHIFT. SNOW WILL GRADUALLY
DECREASE IN COVERAGE AND INTENSITY EARLY MONDAY MORNING AND
CONTINUE TO DECREASE THROUGH THE DAY.
HIGHS TODAY IN THE 30S FOR FAR EASTERN COLORADO WITH 40S AND 50S
GENERALLY EAST OF THE STATE LINE. LOWS TONIGHT MID 20S TO LOW 30S.
MONDAY-MONDAY NIGHT...STORM SYSTEM CONTINUES NORTHEAST INTO IOWA BY
THE END OF THE DAY WITH SOME UPPER RIDGING MOVING TOWARD THE FRONT
RANGE AHEAD OF LARGE SCALE UPPER TROUGH MOVING ASHORE ACROSS THE
PACIFIC NORTHWEST BY 12Z TUESDAY. WILL HAVE QUITE A BIT OF
WRAPAROUND CLOUDINESS DURING THE MORNING WITH A DECREASE ACROSS THE
SOUTHWEST 1/2 OF THE AREA BY MID TO LATE AFTERNOON. FOR THE
OVERNIGHT HOURS CLOUDS CONTINUE TO MOVE OUT OF THE AREA THROUGH
MIDNIGHT BUT CIRRUS INCREASES ACROSS THE SOUTHWEST 1/2 OF THE AREA
TOWARD 12Z TUESDAY. HIGHS IN THE 30S TO NEAR 40 WITH LOWS IN THE
LOW TEENS TO AROUND 20.
TUESDAY-TUESDAY NIGHT...UPPER RIDGE AXIS MOVES ACROSS THE AREA LATE
IN THE DAY AND REMAINS OVER THE AREA THROUGH THE NIGHT. BATCH OF MID
AND HIGH CLOUDS STREAM ACROSS THE AREA DURING THE DAY DECREASING
FROM SOUTHWEST TO NORTHEAST BY SUNSET. FOR THE OVERNIGHT HOURS SOME
HIGH CLOUDS MOVE IN FROM THE WEST/SOUTHWEST. HIGHS IN THE UPPER
20S FOR YUMA COUNTY TO AROUND 40 IN TRIBUNE/LEOTI. LOWS IN THE MID
TEENS TO AROUND 20.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 500 AM MST SUN DEC 14 2014
THE WEDNESDAY THROUGH FRIDAY PERIOD WILL BE NEAR NORMAL
TEMPERATURES AS THE JET STREAM REMAINS SOUTH OF THE AREA. MODELS
HAVE ALMOST DISSOLVED THE PRESENCE OF THE SHORT WAVE TROUGH ON
WEDNESDAY THAT WAS AHEAD OF THE STRONGER TROUGH DEEPENING OVER THE
WEST COAST...SO WILL NOT HAVE ANY SNOWFALL CHANCES FOR WEDNESDAY.
SNOWFALL CHANCES RETURN TO THE FORECAST WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT AS THE UPPER LEVEL LONG WAVE TROUGH OVER THE WEST
COAST MOVES EAST OVER THE DESERT SOUTHWEST TOWARD THE AREA. WITH
THE MAJORITY OF THE UPPER LEVEL DYNAMICS SOUTH OF THE
AREA...SNOWFALL AMOUNTS WILL BE UNDER 3 INCHES AT THIS TIME...WITH
THE HIGHER SNOWFALL AMOUNTS TRENDING FROM WEST TO EAST. HAVE
NOTICED OVER THE LAST COUPLE OF NIGHTS THE MODELS HAVE BEGUN NUDGING
THE LONG WAVE TROUGH NORTHWARD AS IT LIFTS NORTHEAST OVER THE
PLAINS...BRINGING THE UPPER LEVEL DYNAMICS CLOSER TO THE AREA AND
INCREASING THE POTENTIAL FOR MORE SNOWFALL. BY FRIDAY THE SNOWFALL
WILL COME TO AN END AS THE LONG WAVE TROUGH MOVES EAST OF THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1032 AM MST SUN DEC 14 2014
COMPLICATED TAFS AS STRONG UPPER LOW WILL CONTINUE TO IMPACT
FLIGHT CONDITIONS OVER BOTH KGLD AND KMCK. MODERATE TO HEAVY RAIN
AND ISOLATED THUNDERSTORMS WILL IMPACT BOTH TERMINALS THIS
AFTERNOON WITH A TRANSITION TO SNOW AND BLOWING SNOW THIS EVENING.
IFR/MVFR FLIGHT CONDITIONS WILL TRANSITION TO LIFR/VLIFR THIS
EVENING AND OVERNIGHT...WITH SNOW AND BLOWING SNOW IMPACTING KGLD
FIRST (AROUND 00Z) AND KMCK LATER (AFTER 06Z). WINDS GUSTING
30-35KT ARE EXPECTED TONIGHT THROUGH MIDDAY MONDAY. WHILE
CONDITIONS WILL IMPROVE 10-13Z TIME FRAME...I AM MOST CONFIDENT
IN PREVAILING VFR AT KGLD AFTER 12Z. SNOW AND BLOWING SNOW MAY
LINGER AT KMCK THROUGH MIDDAY MONDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY FROM 2 PM MST /3 PM CST/ THIS AFTERNOON
TO 8 AM MST /9 AM CST/ MONDAY FOR KSZ001-002-013.
CO...WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO 8 AM MST
MONDAY FOR COZ091.
WINTER STORM WARNING FROM 2 PM THIS AFTERNOON TO 8 AM MST MONDAY
FOR COZ090.
NE...WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 9 AM CST
MONDAY FOR NEZ080-081.
WINTER STORM WARNING FROM 2 PM THIS AFTERNOON TO 8 AM MST MONDAY
FOR NEZ079.
&&
$$
UPDATE...DR
SHORT TERM...99
LONG TERM...99
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
946 AM MST SUN DEC 14 2014
.UPDATE...
ISSUED AT 946 AM MST SUN DEC 14 2014
MADE ADJUSTMENTS TO POP/WX/QPF/SNOW TO ACCOUNT FOR CURRENT
COVERAGE AND TIMING OF PRECIP. NEAR FREEZING TO SUB FREEZING
TEMPS WERE REPORTED ACROSS NW PARTS OF THE CWA AS MODERATE RAIN
WAS MOVING NORTH. MELTING LAYER APPEARS TO BE AROUND 3500FT BASED
ON DUAL POL FIELDS...AND RAP GENERALLY KEEPS WARM LAYER ALOFT IN
PLACE INTO THIS AFTERNOON. I WAS CONCERNED THAT AS LONG AS
SURFACE TEMPS WERE BELOW FREEZING WE COULD SEE FREEZING RAIN
ACCUMULATION...BUT SURFACES HAVE BEEN SLOWER TO RESPOND AND AIR
TEMPS ARE NOW MODERATING. I INCLUDED FREEZING RAIN MENTION THIS
MORNING AND ISSUED SPS EARLIER...HOWEVER AT THIS POINT THOUGHT IS
ANY ICING WOULD BE LOCALIZED THIS MORNING...WITH A STRAIGHT RAIN
TO SNOW TRANSITION.
IMPACT OF DRY SLOT MOVING NORTH (APPARENT ON WV IMAGERY) IS A
CONCERN. RAP SEEMS TO HAVE A DECENT HANDLE ON THIS...AND SHOWS
LESS PESSIMISTIC QPF VALUES IN OUR KS COUNTIES AND A SLOWER TIMING
ON SNOW DEVELOPMENT. I MADE SOME ADJUSTMENTS TO TIMING AND
AMOUNTS...BUT HELD OFF MAJOR OVERHAUL AS AREAS IN ADVISORY STILL
APPEAR TO SEE FAVORABLE RATES THIS EVENING OVERNIGHT. NOT
PLANNING ON CHANGING HAZARDS THIS MORNING...BUT WILL NEED TO
MONITOR.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 500 AM MST SUN DEC 14 2014
TODAY-TONIGHT...POTENT CLOSED LOW JUST STARTING TO DEVELOP OVER
NEW MEXICO AT THE BASE OF UPPER TROUGH THIS MORNING. THUNDERSTORMS
HAVE BROKEN OUT AHEAD OF THIS FEATURE AND ARE PUSHING INTO
SOUTHEAST COLORADO RIGHT NOW. BY 18Z THE LOW IS FORECAST TO REACH
SOUTHEAST COLORADO/SOUTHWEST KANSAS BORDER THEN OVER GARDEN CITY
BY DARK. AROUND MIDNIGHT THE LOW IS EXPECTED TO BE NEAR PRATT/HAYS
AREA THEN INTO THE TOPEKA AREA BY SUNRISE MONDAY MORNING.
A PLETHORA OF WEATHER POSSIBILITIES EXIST TODAY. RAIN WILL BE THE
INITIAL PRECIP TYPE WITH THUNDERSTORMS POSSIBLE AHEAD OF THE COLD
FRONT/WIND SHIFT. DURING THE LATE AFTERNOON HOURS COLDER AIR MOVES
IN WITH THE FRONT BRINGING A SMALL WINDOW OF SLEET AND MOST LIKELY
SNOW FROM WEST TO EAST. THUNDERSTORMS REMAIN POSSIBLE IN THE
NORTON AND HILL CITY AREAS TIL NEARLY MIDNIGHT.
WITH THE SNOW WILL COME NORTH TO NORTHWEST WINDS GUSTING TO 45
MPH. THIS WILL CREATE REDUCED VISIBILITIES IN SNOW AND BLOWING
SNOW. TOYED WITH A BLIZZARD WARNING FOR YUMA AND DUNDY COUNTIES
WHERE SNOWFALL WILL BE THE HEAVIEST AND GIVEN THE WINDS PRODUCE
VISIBILITIES AROUND 1/2 MILE. HAVE SETTLED ON A WINTER STORM
WARNING FOR YUMA AND DUNDY WHERE UP TO 7 INCHES OF SNOW EXPECTED
ALONG WITH VIS 1/2 MILE OR POSSIBLY LESS. THE ADVISORY AREA ISSUED
YESTERDAY WILL SEE NO CHANGES THIS SHIFT. SNOW WILL GRADUALLY
DECREASE IN COVERAGE AND INTENSITY EARLY MONDAY MORNING AND
CONTINUE TO DECREASE THROUGH THE DAY.
HIGHS TODAY IN THE 30S FOR FAR EASTERN COLORADO WITH 40S AND 50S
GENERALLY EAST OF THE STATE LINE. LOWS TONIGHT MID 20S TO LOW 30S.
MONDAY-MONDAY NIGHT...STORM SYSTEM CONTINUES NORTHEAST INTO IOWA BY
THE END OF THE DAY WITH SOME UPPER RIDGING MOVING TOWARD THE FRONT
RANGE AHEAD OF LARGE SCALE UPPER TROUGH MOVING ASHORE ACROSS THE
PACIFIC NORTHWEST BY 12Z TUESDAY. WILL HAVE QUITE A BIT OF
WRAPAROUND CLOUDINESS DURING THE MORNING WITH A DECREASE ACROSS THE
SOUTHWEST 1/2 OF THE AREA BY MID TO LATE AFTERNOON. FOR THE
OVERNIGHT HOURS CLOUDS CONTINUE TO MOVE OUT OF THE AREA THROUGH
MIDNIGHT BUT CIRRUS INCREASES ACROSS THE SOUTHWEST 1/2 OF THE AREA
TOWARD 12Z TUESDAY. HIGHS IN THE 30S TO NEAR 40 WITH LOWS IN THE
LOW TEENS TO AROUND 20.
TUESDAY-TUESDAY NIGHT...UPPER RIDGE AXIS MOVES ACROSS THE AREA LATE
IN THE DAY AND REMAINS OVER THE AREA THROUGH THE NIGHT. BATCH OF MID
AND HIGH CLOUDS STREAM ACROSS THE AREA DURING THE DAY DECREASING
FROM SOUTHWEST TO NORTHEAST BY SUNSET. FOR THE OVERNIGHT HOURS SOME
HIGH CLOUDS MOVE IN FROM THE WEST/SOUTHWEST. HIGHS IN THE UPPER
20S FOR YUMA COUNTY TO AROUND 40 IN TRIBUNE/LEOTI. LOWS IN THE MID
TEENS TO AROUND 20.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 500 AM MST SUN DEC 14 2014
THE WEDNESDAY THROUGH FRIDAY PERIOD WILL BE NEAR NORMAL
TEMPERATURES AS THE JET STREAM REMAINS SOUTH OF THE AREA. MODELS
HAVE ALMOST DISSOLVED THE PRESENCE OF THE SHORT WAVE TROUGH ON
WEDNESDAY THAT WAS AHEAD OF THE STRONGER TROUGH DEEPENING OVER THE
WEST COAST...SO WILL NOT HAVE ANY SNOWFALL CHANCES FOR WEDNESDAY.
SNOWFALL CHANCES RETURN TO THE FORECAST WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT AS THE UPPER LEVEL LONG WAVE TROUGH OVER THE WEST
COAST MOVES EAST OVER THE DESERT SOUTHWEST TOWARD THE AREA. WITH
THE MAJORITY OF THE UPPER LEVEL DYNAMICS SOUTH OF THE
AREA...SNOWFALL AMOUNTS WILL BE UNDER 3 INCHES AT THIS TIME...WITH
THE HIGHER SNOWFALL AMOUNTS TRENDING FROM WEST TO EAST. HAVE
NOTICED OVER THE LAST COUPLE OF NIGHTS THE MODELS HAVE BEGUN NUDGING
THE LONG WAVE TROUGH NORTHWARD AS IT LIFTS NORTHEAST OVER THE
PLAINS...BRINGING THE UPPER LEVEL DYNAMICS CLOSER TO THE AREA AND
INCREASING THE POTENTIAL FOR MORE SNOWFALL. BY FRIDAY THE SNOWFALL
WILL COME TO AN END AS THE LONG WAVE TROUGH MOVES EAST OF THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 500 AM MST SUN DEC 14 2014
KGLD...MVFR/IFR CONDITIONS THROUGH THE PERIOD. LIGHT FOG FROM TAF
ISSUANCE THROUGH 17Z. RAIN AND POSSIBLY SOME THUNDER FROM 18Z-20Z
WITH LIGHT SHOWERS 20Z-22Z. AFTER 22Z WINDS START TO GUST OVER
30KTS AS COLD FRONT MOVES IN. MAY SEE A SMALL WINDOW FROM 22Z-00Z
FOR RAIN...SLEET AND SNOW BEFORE CHANGING OVER TO SNOW WITH
BLOWING SNOW FROM 00Z THROUGH THE REST OF THE TAF PERIOD.
KMCK...MVFR/IFR CONDITIONS THROUGH THE PERIOD. LIGHT FOG FROM TAF
ISSUANCE THROUGH 15Z. LIGHT/MODERATE RAIN WITH THUNDER FROM 16Z
THROUGH 03Z. FROM 04Z TO 06Z A MIX OF RAIN AND SNOW AS NORTH WINDS
GUST TO 30KTS ANNOUNCING THE COLD FRONTS ARRIVAL. AFTER 06Z NORTH
WINDS GUSTING 30KTS WITH LIGHT SNOW AND BLOWING SNOW.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY FROM 2 PM MST /3 PM CST/ THIS AFTERNOON
TO 8 AM MST /9 AM CST/ MONDAY FOR KSZ001-002-013.
CO...WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO 8 AM MST
MONDAY FOR COZ091.
WINTER STORM WARNING FROM 2 PM THIS AFTERNOON TO 8 AM MST MONDAY
FOR COZ090.
NE...WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 9 AM CST
MONDAY FOR NEZ080-081.
WINTER STORM WARNING FROM 2 PM THIS AFTERNOON TO 8 AM MST MONDAY
FOR NEZ079.
&&
$$
UPDATE...DR
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1145 PM CST Sat Dec 13 2014
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Sunday)
Issued at 311 PM CST SAT DEC 13 2014
20Z water vapor imagery shows the upper level trough out west
continuing to progress east into the Rockies. Meanwhile the upper
ridge overhead is slowly weakening as height falls spread east. At
the surface, southerly low level flow persists between a ridge over
the southeast and troughing in the lee of the Rockies. Dewpoints in
the lower and middle 50s continue to move north into the central
plains.
Tonight there remains little large scale forcing, but the general
subsidence from the upper ridge should go away as it weakens.
Because of the lack of forcing, think chances for measurable precip
are relatively small given the moisture will be capped by the pesky
inversion and no real lift to force the moisture above the
inversion. However the continued advection of higher dewpoints north
along with some modest isentropic lift could lead to areas of
drizzle overnight. The RAP and NAM suggest isentropic lift will not
be any better organized than what is occurring this afternoon. So
thinking is the drizzle overnight will only amount to a trace. Temps
are expected to remain fairly steady with overcast skies and south
winds preventing any cooling. Min temps are forecast to be in the
lower to mid 50s
Sunday will see increasing large scale forcing in the form of
vorticity advection as the upper trough propagates east and a
negatively tilted shortwave lifts out from the southern Rockies. The
combination of the forcing with mid level cooling is expected to
create some modest convective instability (surface based CAPE around
500 J/KG). With this in mind, showers and thunderstorms should
develop over the southern high plains and spread into central KS by
the afternoon. Any strong to severe thunderstorms seem to be
dependent on the degree of surface heating and resultant
destabilization. At this point, heating is forecast to be modest due
to overcast skies. Although it is not out of the question there
could be a strong storm or two with some hail and wind. Highs Sunday
should be around 60 as southerly flow and warm air advection
persists.
.LONG TERM...(Sunday Night through Saturday)
Issued at 307 PM CST SAT DEC 13 2014
Initial band of precip with likely embedded convection should be
moving through Sunday evening. Kept PoPs above guidance but could
see a few places miss some precip in possible gaps in the band.
Minor instability still anticipated with this band, with somewhat
greater concern for severe weather arises in the evening to early
overnight hours with south low level winds persisting and wind
fields increasing as models are in good agreement with another area
of precip developing NE of the of the upper low. The NAM seems a bit
overdone with CAPE, mostly via cooling around 925mb on SW winds,
which seems unlikely. Still, with low tops the CAPE that is there is
a more impressive and minor wind and hail concerns remain. Monday
into Monday brings steady drying conditions but decreased PoPs
somewhat Monday night with NE KS well on the back side of this
system. Still have a hard time seeing much more than rain fall with
this event, with ice crystals aloft becoming hard to come by as the
lower levels cool. Falling temps on track for the daytime hours
Monday as NW winds increase.
Tuesday into at least Tuesday night still looking dry, but models
continue to struggle with upper troughing splitting NE into Canada
and SE into the southern tier states as well as how energy will
interact with an upper high pushing east across the southern
Canadian provinces. This puts much of the Northern and Central Plains
in weak flow and seasonable temperature fields, with any waves
passing near enough from the south to bring light precip
potential, with the later work week periods again looking the most
likely for this to occur. Low chance PoPs at best are in order
with somewhat cooler lower levels supporting less mixed precip
potential.
&&
.AVIATION...(For the 06Z TAFs through 06Z Sunday Night)
Issued at 1136 PM CST SAT DEC 13 2014
Previous thoughts were that IFR conditions were prevail through
mid day tomorrow. Although conditions have currently improved to
MVFR. Since the model guidance does not imply this happening have
added a tempo for this variance. Towards the end of the period a
strong system will bring rain and thunderstorms. Decided not to
focus on thunderstorm possibilities and timing at this point.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...65
AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS GAYLORD MI
600 PM EST SUN DEC 14 2014
.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 412 PM EST SUN DEC 14 2014
...FOG AND STRATUS WITH STEADY TEMPS TONIGHT...
IMPACTS: DENSE FOG.
PER LATEST RAP ANALYSIS...DEEP LAYER N-S RIDGE AXIS NOW BISECTING
LAKE MICHIGAN...570 DM LINE UP ACROSS NRN LOWER MICHIGAN...WITH DEEP
CLOSED LOWS OVER THE WESTERN CONUS AND JUST OFFSHORE INTO THE
ATLANTIC. BUT OF COURSE...EXTENSIVE STRATUS AND FOG REMAINS DRAPED
ACROSS ALL THE GREAT LAKES AND MUCH OF THE MIDWEST...ALTHOUGH
THERE HAVE BEEN SOME RANDOM THINNING TO THE CLOUDS IN SPOTS AND
EVEN A FEW PEEKS OF SUN.
AS A SIDE NOTE...A RECORD 500 MB HEIGHT FOR THIS DATE OF 571 DM
WAS OBSERVED ON THIS MORNINGS 12Z APX SOUNDING...AND CLOSE TO THE
RECORD 500 MB HEIGHT FOR THE ENTIRE MONTH OF DECEMBER (5730 M).
BUT...A 850 MB TEMP OF 11.35C OBSERVED ON LAST EVENINGS APX
SOUNDING IS THE WARMEST 850 MB TEMP OBSERVED IN DECEMBER FOR NRN
MICHIGAN (PER SPC SOUNDING CLIMO STATS FROM ALL APX AND SSM UPPER
AIR SOUNDINGS GOING BACK TO 1948).
TONIGHT...STATUS QUO. STRATUS/FOG WILL ONCE AGAIN BE THE NAME OF
THE GAME. IN FACT...GUIDANCE REVEALS A BIGGER SURGE OF LOW LEVEL
MOISTURE BETWEEN 900 MB AND 800 MB (THICKER CLOUD COVER IS
EVIDENT ON SATELLITE IMAGERY ABOUT TO STREAM INTO THE REGION AND
IT IS ALSO EVIDENT ON GRB/S VAD WIND PROFILE). THIS RESULTS IN A
DEEPENING SFC BASED SATURATED LAYER AS WE GO THROUGH THE NIGHT AND
SUPPORTS THE IDEA OF WIDESPREAD DRIZZLE DEVELOPMENT. SO LITTLE OR
NO CHANGES MADE TO THE GOING FORECAST.
&&
.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 412 PM EST SUN DEC 14 2014
...RAIN LOOKING LIKELY LATE MONDAY INTO TUESDAY...TURNING COOLER
MID-WEEK SOME SNOW EXPECTED...
HIGH IMPACT WEATHER POTENTIAL: LOCALLY DENSE FOG THROUGH MONDAY
MORNING. POTENTIAL FOR MOSTLY LIGHT SNOW ACCUMULATIONS TUESDAY NIGHT
INTO WEDNESDAY.
PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: CURRENT VERY ANOMALOUSLY
AMPLIFIED PATTERN EXPECTED TO GO THROUGH SOME CHANGES HEADING
THROUGH THE UPCOMING WEEK. DRIVER BEHIND SUCH IS A RATHER AGGRESSIVE
SPLIT FLOW PATTERN TO OUR WEST...THE LIKES OF WHICH WILL DRIVE A
PAIR OF RATHER SUBSTANTIAL SHORTWAVES THROUGH OUR AREA TO START THE
WORK WEEK. LEAD SOUTHERN STREAM ENERGY WILL BRING A ROUND OF WET
WEATHER MONDAY NIGHT INTO TUESDAY...WITH A DEEPENING NORTHERN STREAM
WAVE EXPECTED TO BRING A RETURN TO MORE TYPICAL DECEMBER WEATHER (AT
LEAST BRIEFLY) INTO MID WEEK.
PRIMARY FORECAST CHALLENGES/CONCERNS: ADDRESSING RAIN CONCERNS
THROUGH EARLY TUESDAY. TEMPERATURE TRENDS AND TRANSITION TO SNOW
THEREAFTER...ALONG WITH AT LEAST SOME POTENTIAL FOR A LITTLE
ACCUMULATION.
DETAILS: SIMPLY MORE OF THE SAME MUCH OF MONDAY WITH A SLOWLY
DEEPENING MOIST LAYER THROUGH THE DAY. DESPITE THIS...STILL APPEARS
A RATHER SUBSTANTIAL DISCONNECT WILL EXIST BETWEEN UPPER LEVEL AND
LOW LEVEL MOISTURE...SUPPORTING MORE OF A DRIZZLE/LOW CLOUD SCENARIO
THAN BONA FIDE MEASURABLE RAIN. THAT ALL CHANGES HEADING INTO MONDAY
NIGHT WITH APPROACH OF RATHER VIGOROUS SOUTHERN STREAM...WITH FORCED
ASCENT COMPLETING THE SATURATION PROCESS AS PWAT VALUES SURGE TO
NEAR THREE QUARTERS OF AN INCH. LIGHT RAIN WILL BECOME RATHER
WIDESPREAD OVERNIGHT...LASTING INTO THE START OF TUESDAY. WHILE
SOUTHERN STREAM INFLUENCES BEGIN TO DEPART LATER TUESDAY...NORTHERN
STREAM DYNAMICS BEGIN TO RAMP UP VIA STRONG SHORTWAVE DIVING INTO
THE NORTHWEST LAKES. DEEPENING COLD AIR ADVECTION EXPECTED TO FORCE
A CHANGEOVER TO SNOW FROM WEST TO EAST LATER TUESDAY...WITH ALL
AREAS COLD ENOUGH TO SUPPORT SNOW BY LATER TUESDAY EVENING. STARTING
TO LOOK LIKE MID LEVEL DRY SLOTTING WILL PUSH INTO MUCH OF NORTHERN
LOWER OVERNIGHT TUESDAY...WITH DEEPER MOISTURE TIED TO INCREASING
DEFORMATION FORCING LAYING OUT FOR AREAS IN THE STRAITS AND UPPER
MICHIGAN. LAKE SUPERIOR WILL ONLY HELP THE CAUSE AS INSTABILITY
RAMPS UP VIA STEADILY COOLING LOW LEVELS. NOT LOOKING LIKE A
PARTICULAR BIG SNOW EVENT...BUT COULD EASILY SEE A COUPLE INCHES FOR
PARTS OF EASTERN UPPER BY WEDNESDAY MORNING. LESS AMOUNTS FOR
NORTHERN LOWER...WITH SOME LIGHT ACCUMULATIONS TARGETING THE
TRADITIONAL SNOW BELTS. WNW-NW FLOW LAKE SNOWS EXPECTED TO CONTINUE
WEDNESDAY AS H8 TEMPERATURES DROP INTO THE NEGATIVE TEENS AND
NORTHERN STREAM WAVE SHEARS ACROSS THE AREA. SYNOPTIC/LAKE AUGMENTED
SURFACE TROUGHING SHOULD HELP WITH LOW LEVEL CONVERGENCE...
ESPECIALLY ACROSS EASTERN UPPER. LAKE INDUCED CLOUDS WILL BE WELL
PLACED WITHIN THE DGZ...ALTHOUGH LIMITED INVERSION LEVELS SHOULD
KEEP AMOUNTS FROM GETTING TOO OUT OF HAND. ALL TOLD...COULD SEE
ANOTHER COUPLE INCHES IN FAVORED AREAS. WILL KICK AROUND THE IDEA OF
AT LEAST INTRODUCING THIS SNOW POTENTIAL IN OUR LATEST HAZARDOUS
WEATHER PRODUCTS.
&&
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 412 PM EST SUN DEC 14 2014
BUILDING HIGH PRESSURE WILL CLEAR OUT ANY LINGERING SNOW SHOWERS BY
THURSDAY EVENING. LOW PRESSURE WILL BE PASSING SOUTH OF THE REGION
ON SATURDAY NIGHT...WITH SOME UNCERTAINTY IN THE TRACK. A MORE
NORTHERN SOLUTION COULD BRING SOME MINOR SNOWFALL WITH MOISTURE A
BIT LACKING. A SOUTHERN SOLUTION WILL LEAVE US DRY FOR ANOTHER DAY.
WILL KEEP THINGS DRY FOR NOW...KEEPING AN EYE ON THE DEVELOPMENT OF
THIS LOW PRESSURE. TEMPERATURES WILL BE NEAR NORMAL FOR THE PERIOD
WITH HIGHS IN THE UPPER 20S AND LOW 30S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 600 PM EST SUN DEC 14 2014
LOW STRATUS...FOG AND AREAS OF DRIZZLE RESULTING IN IFR
CONDITIONS WILL CONTINUE TO IMPACT ALL NRN LWR MICHIGAN TAF SITES
THRU MONDAY NIGHT AS AMPLE LOW LEVEL MOISTURE REMAINS TRAPPED
BELOW THE STRONG SUBSIDENCE INVERSION. CALM WINDS TONIGHT INTO
EARLY MONDAY WILL BECOME SOUTH BELOW 10 KTS ON MONDAY.
&&
.MARINE...
ISSUED AT 412 PM EST SUN DEC 14 2014
LIGHT WINDS THROUGH TONIGHT. A BIT STRONGER SOUTHERLY WIND WILL
DEVELOP ACROSS THE REGION MONDAY WITH SOME GUSTS GETTING UP CLOSE
TO SMALL CRAFT ADVISORY CRITERIA. BUT NO HEADLINES ARE ANTICIPATED
AT THIS POINT. WINDS TURN BACK INTO THE N/NW ON TUESDAY WITH
GUSTIER WINDS. MARINE HEADLINES MAY BE NEEDED AT THAT POINT...BUT
GALE FORCE GUSTS ARE NOT ANTICIPATED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
SHORT TERM...MSB
SHORT TERM...MSB
LONG TERM...ALM
AVIATION...MLR
MARINE...ADAM
AREA FORECAST DISCUSSION
NWS GAYLORD MI
412 PM EST SUN DEC 14 2014
.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 412 PM EST SUN DEC 14 2014
...FOG AND STRATUS WITH STEADY TEMPS TONIGHT...
IMPACTS: DENSE FOG.
PER LATEST RAP ANALYSIS...DEEP LAYER N-S RIDGE AXIS NOW BISECTING
LAKE MICHIGAN...570 DM LINE UP ACROSS NRN LOWER MICHIGAN...WITH DEEP
CLOSED LOWS OVER THE WESTERN CONUS AND JUST OFFSHORE INTO THE
ATLANTIC. BUT OF COURSE...EXTENSIVE STRATUS AND FOG REMAINS DRAPED
ACROSS ALL THE GREAT LAKES AND MUCH OF THE MIDWEST...ALTHOUGH
THERE HAVE BEEN SOME RANDOM THINNING TO THE CLOUDS IN SPOTS AND
EVEN A FEW PEEKS OF SUN.
AS A SIDE NOTE...A RECORD 500 MB HEIGHT FOR THIS DATE OF 571 DM
WAS OBSERVED ON THIS MORNINGS 12Z APX SOUNDING...AND CLOSE TO THE
RECORD 500 MB HEIGHT FOR THE ENTIRE MONTH OF DECEMBER (5730 M).
BUT...A 850 MB TEMP OF 11.35C OBSERVED ON LAST EVENINGS APX
SOUNDING IS THE WARMEST 850 MB TEMP OBSERVED IN DECEMBER FOR NRN
MICHIGAN (PER SPC SOUNDING CLIMO STATS FROM ALL APX AND SSM UPPER
AIR SOUNDINGS GOING BACK TO 1948).
TONIGHT...STATUS QUO. STRATUS/FOG WILL ONCE AGAIN BE THE NAME OF
THE GAME. IN FACT...GUIDANCE REVEALS A BIGGER SURGE OF LOW LEVEL
MOISTURE BETWEEN 900 MB AND 800 MB (THICKER CLOUD COVER IS
EVIDENT ON SATELLITE IMAGERY ABOUT TO STREAM INTO THE REGION AND
IT IS ALSO EVIDENT ON GRB/S VAD WIND PROFILE). THIS RESULTS IN A
DEEPENING SFC BASED SATURATED LAYER AS WE GO THROUGH THE NIGHT AND
SUPPORTS THE IDEA OF WIDESPREAD DRIZZLE DEVELOPMENT. SO LITTLE OR
NO CHANGES MADE TO THE GOING FORECAST.
&&
.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 412 PM EST SUN DEC 14 2014
...RAIN LOOKING LIKELY LATE MONDAY INTO TUESDAY...TURNING COOLER
MID-WEEK SOME SNOW EXPECTED...
HIGH IMPACT WEATHER POTENTIAL: LOCALLY DENSE FOG THROUGH MONDAY
MORNING. POTENTIAL FOR MOSTLY LIGHT SNOW ACCUMULATIONS TUESDAY NIGHT
INTO WEDNESDAY.
PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: CURRENT VERY ANOMALOUSLY
AMPLIFIED PATTERN EXPECTED TO GO THROUGH SOME CHANGES HEADING
THROUGH THE UPCOMING WEEK. DRIVER BEHIND SUCH IS A RATHER AGGRESSIVE
SPLIT FLOW PATTERN TO OUR WEST...THE LIKES OF WHICH WILL DRIVE A
PAIR OF RATHER SUBSTANTIAL SHORTWAVES THROUGH OUR AREA TO START THE
WORK WEEK. LEAD SOUTHERN STREAM ENERGY WILL BRING A ROUND OF WET
WEATHER MONDAY NIGHT INTO TUESDAY...WITH A DEEPENING NORTHERN STREAM
WAVE EXPECTED TO BRING A RETURN TO MORE TYPICAL DECEMBER WEATHER (AT
LEAST BRIEFLY) INTO MID WEEK.
PRIMARY FORECAST CHALLENGES/CONCERNS: ADDRESSING RAIN CONCERNS
THROUGH EARLY TUESDAY. TEMPERATURE TRENDS AND TRANSITION TO SNOW
THEREAFTER...ALONG WITH AT LEAST SOME POTENTIAL FOR A LITTLE
ACCUMULATION.
DETAILS: SIMPLY MORE OF THE SAME MUCH OF MONDAY WITH A SLOWLY
DEEPENING MOIST LAYER THROUGH THE DAY. DESPITE THIS...STILL APPEARS
A RATHER SUBSTANTIAL DISCONNECT WILL EXIST BETWEEN UPPER LEVEL AND
LOW LEVEL MOISTURE...SUPPORTING MORE OF A DRIZZLE/LOW CLOUD SCENARIO
THAN BONA FIDE MEASURABLE RAIN. THAT ALL CHANGES HEADING INTO MONDAY
NIGHT WITH APPROACH OF RATHER VIGOROUS SOUTHERN STREAM...WITH FORCED
ASCENT COMPLETING THE SATURATION PROCESS AS PWAT VALUES SURGE TO
NEAR THREE QUARTERS OF AN INCH. LIGHT RAIN WILL BECOME RATHER
WIDESPREAD OVERNIGHT...LASTING INTO THE START OF TUESDAY. WHILE
SOUTHERN STREAM INFLUENCES BEGIN TO DEPART LATER TUESDAY...NORTHERN
STREAM DYNAMICS BEGIN TO RAMP UP VIA STRONG SHORTWAVE DIVING INTO
THE NORTHWEST LAKES. DEEPENING COLD AIR ADVECTION EXPECTED TO FORCE
A CHANGEOVER TO SNOW FROM WEST TO EAST LATER TUESDAY...WITH ALL
AREAS COLD ENOUGH TO SUPPORT SNOW BY LATER TUESDAY EVENING. STARTING
TO LOOK LIKE MID LEVEL DRY SLOTTING WILL PUSH INTO MUCH OF NORTHERN
LOWER OVERNIGHT TUESDAY...WITH DEEPER MOISTURE TIED TO INCREASING
DEFORMATION FORCING LAYING OUT FOR AREAS IN THE STRAITS AND UPPER
MICHIGAN. LAKE SUPERIOR WILL ONLY HELP THE CAUSE AS INSTABILITY
RAMPS UP VIA STEADILY COOLING LOW LEVELS. NOT LOOKING LIKE A
PARTICULAR BIG SNOW EVENT...BUT COULD EASILY SEE A COUPLE INCHES FOR
PARTS OF EASTERN UPPER BY WEDNESDAY MORNING. LESS AMOUNTS FOR
NORTHERN LOWER...WITH SOME LIGHT ACCUMULATIONS TARGETING THE
TRADITIONAL SNOW BELTS. WNW-NW FLOW LAKE SNOWS EXPECTED TO CONTINUE
WEDNESDAY AS H8 TEMPERATURES DROP INTO THE NEGATIVE TEENS AND
NORTHERN STREAM WAVE SHEARS ACROSS THE AREA. SYNOPTIC/LAKE AUGMENTED
SURFACE TROUGHING SHOULD HELP WITH LOW LEVEL CONVERGENCE...
ESPECIALLY ACROSS EASTERN UPPER. LAKE INDUCED CLOUDS WILL BE WELL
PLACED WITHIN THE DGZ...ALTHOUGH LIMITED INVERSION LEVELS SHOULD
KEEP AMOUNTS FROM GETTING TOO OUT OF HAND. ALL TOLD...COULD SEE
ANOTHER COUPLE INCHES IN FAVORED AREAS. WILL KICK AROUND THE IDEA OF
AT LEAST INTRODUCING THIS SNOW POTENTIAL IN OUR LATEST HAZARDOUS
WEATHER PRODUCTS.
&&
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 412 PM EST SUN DEC 14 2014
BUILDING HIGH PRESSURE WILL CLEAR OUT ANY LINGERING SNOW SHOWERS BY
THURSDAY EVENING. LOW PRESSURE WILL BE PASSING SOUTH OF THE REGION
ON SATURDAY NIGHT...WITH SOME UNCERTAINTY IN THE TRACK. A MORE
NORTHERN SOLUTION COULD BRING SOME MINOR SNOWFALL WITH MOISTURE A
BIT LACKING. A SOUTHERN SOLUTION WILL LEAVE US DRY FOR ANOTHER DAY.
WILL KEEP THINGS DRY FOR NOW...KEEPING AN EYE ON THE DEVELOPMENT OF
THIS LOW PRESSURE. TEMPERATURES WILL BE NEAR NORMAL FOR THE PERIOD
WITH HIGHS IN THE UPPER 20S AND LOW 30S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1250 PM EST SUN DEC 14 2014
IFR-LIFR CONDITIONS CONTINUE TO DOMINATE NRN LOWER MICHIGAN AND
MUCH OF THE GREAT LAKES REGION TODAY...AND WILL CONTINUE TO DO SO
TONIGHT THROUGH MONDAY MIDDAY. PER SATELLITE DATA...THERE ARE A
FEW HOLES/BREAKS IN THE CLOUDS OUT THERE THAT MAY BRING SOME
TEMPORARY IMPROVEMENT TO CIGS/BRIEF MVFR CONDITIONS. BUT TIMING
THOSE RANDOM IMPROVEMENTS IS A TALL ORDER. OVERALL...ANTICIPATE
IFR CONDITIONS THROUGH MIDDAY MONDAY.
WINDS...LIGHT (5 KNOTS OR LESS) AND SOMEWHAT VARIABLE THROUGH
MONDAY...ALTHOUGH A PREVAILING LIGHT SOUTHERLY FLOW WILL BE IN
PLACE TODAY THROUGH MONDAY.
&&
.MARINE...
ISSUED AT 412 PM EST SUN DEC 14 2014
LIGHT WINDS THROUGH TONIGHT. A BIT STRONGER SOUTHERLY WIND WILL
DEVELOP ACROSS THE REGION MONDAY WITH SOME GUSTS GETTING UP CLOSE
TO SMALL CRAFT ADVISORY CRITERIA. BUT NO HEADLINES ARE ANTICIPATED
AT THIS POINT. WINDS TURN BACK INTO THE N/NW ON TUESDAY WITH
GUSTIER WINDS. MARINE HEADLINES MAY BE NEEDED AT THAT POINT...BUT
GALE FORCE GUSTS ARE NOT ANTICIPATED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
NEAR TERM...ADAM
SHORT TERM...MSB
LONG TERM...ALM
AVIATION...ADAM
MARINE...ADAM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
323 PM EST SUN DEC 14 2014
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE
.SYNOPSIS...
ISSUED AT 323 PM EST SUN DEC 14 2014
FOG WITH AREAS OF DRIZZLE WILL CONTINUE INTO MONDAY WITH
UNSEASONABLY MILD TEMPERATURES... MOSTLY IN THE 40S.
MEANWHILE A DEVELOPING STORM SYSTEM OVER THE SOUTHERN PLAINS WILL
HEAD NORTHEAST TOWARD THE WESTERN GREAT LAKES BY MONDAY NIGHT.
THAT WILL SPREAD RAIN INTO THE AREA MONDAY NIGHT WHICH WILL
CONTINUE INTO TUESDAY AFTERNOON BEFORE THE COLD AIR COMES IN. ONCE
THE COLD AIR SURGES IN LATER IN THE DAY TUESDAY THE RAIN WILL
CHANGE TO SNOW SHOWERS AND TEMPERATURES WILL FALL INTO THE 20S.
THE SNOW SHOWERS WILL CONTINUE INTO WEDNESDAY NIGHT WITH SOME
ACCUMULATIONS NEAR AND WEST OF US-131.
A LARGE CANADIAN HIGH PRESSURE SYSTEM SHOULD INFLUENCE SOUTHWEST
MICHIGAN WEATHER THURSDAY THROUGH NEXT WEEKEND. THAT HIGH SHOULD
BLOCK THE NEXT STORM SYSTEM FROM THE WESTERN GULF FROM REACHING
MICHIGAN ON SATURDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 323 PM
EST SUN DEC 14 2014
WE HAVE SEVERAL ISSUES WITH THIS FORECAST PACKAGE. THE FIRST IS
THE FOG AND DRIZZLE TONIGHT INTO MONDAY. THEN WE HAVE THE RAIN
FROM THE SYSTEM THAT COMES THROUGH MONDAY NIGHT INTO TUESDAY.
FINALLY LAKE ENHANCED SNOW FOLLOWS FOR TUESDAY NIGHT THROUGH
WEDNESDAY.
LIKE THE PAST 2 DAYS THE FOG IS THICKEST DURING THE DAY AND THINS
OUT AFTER SUNSET. THE AREA OF DENSE FOG IS NOT NEARLY AS EXTENSIVE
TODAY AS IT WAS YESTERDAY AFTERNOON AT THIS TIME SO I DO NOT SEE ANY
ISSUE WITH HAVING TO PUT OUT A DENSE FOG ADVISORY. UNLIKE THE PAST
FEW DAYS THROUGH THE UPPER RIDGE IS NOW EAST OF SOUTHWEST MICHIGAN
WHICH MEANS THE WINDS TURN TO THE SOUTH THROUGH A DEEP LAYER. THAT
SHOULD BRING UP THE WARMER AIR JUST TO OUR SOUTH. MEANWHILE ALL OF
THE SHORT TERM... HIGH RESOLUTION... MODELS SUGGEST THE FOG AND LOW
CLOUDS WILL PERSIST INTO MONDAY. THE HRRR AND RAP13 SHOW INCREASED
LIFT IN THE LAYER BELOW THE INVERSION...SUGGESTING THE COVERAGE OF
DRIZZLE SHOULD INCREASE WITHIN THE NEXT FEW HOURS. SO I CONTINUED
THE FOG AND DRIZZLE FORECAST INTO MONDAY.
NEXT UP IS THE SYSTEM NOW DEVELOPING OVER SOUTHWEST KANSAS AND NORTHERN
TEXAS LATE THIS AFTERNOON. THIS SYSTEM IS UNDER A NEGATIVE TILT UPPER
WAVE THAT IS ALREADY CLOSED OFF AT UPPER LEVELS AND LOOKS RATHER
IMPRESSIVE ON THE WATER VAPOR LOOPS. IF IT WERE JUST THAT SYSTEM
IT WOULD DEEPEN AND TRACK WELL WEST OF MICHIGAN HOWEVER AT THE
SAME TIME WE HAVE A DIGGING NORTHERN STREAM WAVE. SO INSTEAD OF
GOING WEST OF MICHIGAN...THE NORTHERN STREAM WAVE FORCES IT TO
ROTATE AROUND A REORGANIZED UPPER LOW OVER THE GREAT LAKES TUESDAY
INTO WEDNESDAY. THE RESULT OF THAT IS THE BEST MOISTURE INFLOW
GETS CUT OFF BEFORE THE SYSTEM REACHES THIS AREA. EVEN SO WE STILL
GET SOME DEEP MOISTURE AS THE PRECIPITABLE WATER RISES FROM AROUND
A 1/2 INCH NOW TO NEARLY 3/4 OF AN INCH MONDAY EVENING. THERE IS
GOOD BUT BRIEF DEEP LIFT TUESDAY NIGHT AS THE SYSTEM MOVES INTO
THE AREA. SO I WILL RAIN MONDAY NIGHT BUT IT WILL MOSTLY BE LIGHT
RAIN...UNDER A 1/2 INCH.
FINALLY THE COLD AIR COMES IN TUESDAY AFTERNOON WHILE THE MOISTURE
IS STILL FAIRLY DEEP...SO RAIN SHOWS WILL PERSIST THROUGH THE
DAY. IT BECOMES COLD ENOUGH FOR SNOW BY MID EVENING TUESDAY SO THE
RAIN SHOWERS WILL CHANGE TO SNOW SHOWERS. THE COLDEST AIR COMES
OVERHEAD WEDNESDAY EVENING. SO WITH 850 TEMPS BELOW -10C... AND
THE LAKE NEAR 4C.... I WOULD EXPECT LAKE ENHANCED SNOWFALL INTO
WEDNESDAY. WHILE THE INVERSION HEIGHT IS LIMITED... MOSTLY UNDER
6000 FT... THERE IS LIFT AND A WEST WIND... SO THERE WILL BE SNOW
SHOWERS. TUESDAY NIGHT INTO WEDNESDAY. AT THIS POINT I AM THINKING
1 TO 3 INCHES WILL FALL FROM THIS EVENT.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 323 PM EST SUN DEC 14 2014
LAKE EFFECT SNOW SHOWERS WILL LINGER WEDNESDAY NIGHT WITH H8 TEMPS
DOWN TO AROUND -13 TO -15 C WEDNESDAY EVENING ALONG WITH DECENT
LINGERING LOW TO MID LEVEL MOISTURE. A FEW LIGHT SNOW SHOWERS AND
FLURRIES MAY LINGER INTO THURSDAY BEFORE HIGH PRESSURE BUILDS IN TO
PRODUCE FAIR WEATHER WITH SEASONABLE TEMPERATURES LATE IN THE WEEK
INTO NEXT WEEKEND.
THE TRACK OF THE GULF COAST SYSTEM LATE IN THE WEEK WILL HAVE TO BE
MONITORED AS 12Z GFS GUIDANCE SUGGESTS THAT PCPN WITH THAT SYSTEM
COULD CLIP OUR AREA ON SATURDAY. HOWEVER ALL OTHER MEDIUM RANGE
GUIDANCE HAS BEEN PERSISTENT IN SHOWING THIS SYSTEM SHOULD STAY SE
OF OUR AREA.
TEMPS THROUGH THE LONG RANGE FORECAST PERIOD WILL AVERAGE QUITE
CLOSE TO NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY)
ISSUED AT 1130 AM EST SUN DEC 14 2014
PRIMARILY IFR TO LIFR CONDITIONS ARE ANTICIPATED THIS AFTERNOON DUE
TO LOW CLOUDS AND PATCHY FOG AND DRIZZLE. IFR/LIFR CONDITIONS WILL
CONTINUE OVERNIGHT DUE TO LOW CIGS AND LOW VISBYS IN FOG AND PATCHY
DRIZZLE. CONDITIONS ARE LIKELY TO STAY MAINLY IFR THROUGH 18Z MONDAY
DUE TO LOW CIGS AND LOW VISBYS IN FOG. WINDS WILL GRADUALLY SHIFT
FROM THE SOUTHWEST THIS AFTERNOON TO THE SOUTH TONIGHT AND MONDAY
AND REMAIN AOB 10 KTS.
&&
.MARINE...
ISSUED AT 323 PM EST SUN DEC 14 2014
WINDS AND WAVES WILL STAY BELOW SMALL CRAFT ADVISORY CRITERIA
UNTIL THE COLD FRONT COMES THROUGH TUESDAY. WE WILL THEN NEED TO
ISSUE ANOTHER SMALL CRAFT ADVISORY.
&&
.HYDROLOGY...
ISSUED AT 1233 PM EST SUN DEC 14 2014
PRECIPITATION IN THE FORM OF DRIZZLE AND LIGHT RAIN WILL SPAN THE
THE PERIOD BETWEEN NOW AND TUESDAY. ANOTHER DRY PATTERN WILL SET UP
LATER IN THE WEEK. NO IMPACTS ARE EXPECTED ON AREA STREAMS AND
RIVERS THROUGH THE WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...LAURENS
HYDROLOGY...JAM
MARINE...WDM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
306 PM EST SUN DEC 14 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 458 AM EST SUN DEC 14 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SPLIT FLOW PATTERN ACROSS
NORTH AMERICA WITH AN UNSEASONABLY STRONG RIDGE FROM THE MS
VALLEY INTO THE WRN GREAT LAKES DOWNSTREAM FROM A TROUGH ACROSS THE
ROCKIES. AT THE SFC..SRLY WINDS WERE INCREASING FROM THE CENTRAL
PLAINS TOWARD THE UPPER MS VALLEY AHEAD OF A TROUGH FROM CENTRAL
SOUTH DAKOTA INTO WRN NEBRASKA. THE SRLY FLOW AND LOW LEVEL MOISTURE
ADVECTION HAS PUSHED DEWPOINTS TO NEAR 40F FROM CENTRAL MN AND NW WI
TO WRN UPPER MI AND INTO THE MID 30S THROUGH CNTRL UPPER MI. A
PERSISTENT LOW STRATUS DECK HAS HELPED KEEP FOG FROM BECOMING AS
DENSE OVER UPPER MI COMPARED TO LOCATIONS OVER WI.
THERE REMAINS ONLY WEAK IF ANY FORCING FOR UPWARD MOTION OVER UPPER
MI TODAY AS THE AREA REMAINS NEAR THE MID/UPPER LEVEL RIDGE AXIS.
NEVERTHELESS...THE POTENTIAL FOR DRIZZLE SPREADING ACROSS THE AREA
REMAINS AS SOME WEAK UPWARD MOTION IS EXPECTED ABOVE THE THICKENING
LOW LEVEL MOISTURE AHEAD OF THE TROUGH SLIDING INTO THE UPPER MS
VALLEY. DRIZZLE CHANCES WILL INCREASE TOWARD EVENING AS AN AREA OF
290K ISENTROPIC ASCENT IS FORECAST TO MOVE THROUGH UPPER MI...PER
NAM/GFS. IN ADDITION...MELTING SNOW WILL ADD ADDITIONAL MOISTURE TO
SUPPORT DEVELOPMENT OF AREAS OF DENSE FOG. HOWEVER...DIURNAL WARMING
SHOULD BE JUST ENOUGH TO REDUCE THE RISK FOR MORE WIDESPREAD DENSE
FOG. TONIGHT...DENSE FOG WILL BE A BETTER POSSIBILITY WITH DIURNAL
COOING AS DEWPOINTS INTO THE UPPER 30S PREVAIL ACROSS THE AREA. THE
THE POTENTIAL FOR ACCUMULATING PCPN WILL INCREASE LATE TONIGHT OVER
THE WEST WITH DEEPER MOISTURE ARRIVING AHEAD OF THE SFC TROUGH.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 305 PM EST SUN DEC 14 2014
STARTING THE LONG TERM AT 00Z TUE RESULTS IN A SHORTWAVE THAT IS
NEARLY VERTICALLY STACKED OVER A 1001MB SFC LOW IN SERN IA. A SFC
TROUGH EXTENDS NE FROM THE SFC LOW ACROSS LAKE SUPERIOR AND TOWARD
JAMES BAY...WHICH IS AHEAD OF ANOTHER SHORTWAVE OVER NWRN ONTARIO.
RAIN WILL BE ONGOING ACROSS MUCH OF THE AREA AT 00Z TUE AS 850MB AND
SFC TEMPS WILL BE ABOVE FREEZING. COLDER AIR WILL MOVE INTO THE AREA
FROM W TO E MON NIGHT INTO TUE...TRANSITIONING PRECIP TO ALL SNOW
FROM IRONWOOD TO COPPER HARBOR 03Z-09Z TUE...MARQUETTE TO IRON
MOUNTAIN 09Z-12Z...AND OVER THE ERN CWA AROUND 18Z. TRICKY FORECAST
FOR SNOWFALL AMOUNTS AS MODELS DEPICT GREATEST PRECIP OVER/NEAR WRN
LAKE SUPERIOR MON NIGHT ASSOCIATED WITH FGEN AS THE TWO SHORTWAVES
BEGIN TO INTERACT...SO FORECASTING THE EXACT LOCATION OF THE BEST
PRECIP ALONG WITH TIMING OF CHANGE OVER THE SNOW IS DIFFICULT.
THANKFULLY...MODELS ARE IN DECENT AGREEMENT WITH THE SYSTEMS. THE
SRN STREAM SHORTWAVE/SFC LOW SHIFTS E TO SRN LAKE HURON DURING THE
DAY TUE AS THE NRN SHORTWAVE MOVES INTO NRN MN. SYNOPTIC FORCING
WILL TRANSITION TO BEING PRIMARILY FROM THE NRN SHORTWAVE THROUGH
THE DAY TUE AND WITH 850MB TEMPS DROPPING TO AROUND -15C OVER WRN
LAKE SUPERIOR BY 00Z WED...LAKE ENHANCED/EFFECT SNOW WILL DEVELOP
FROM W TO E. 850MB TEMPS CONTINUE TO BE COLD THROUGH WED AS THE
SHORTWAVE MOVES JUST S OF THE CWA /ALTHOUGH THE 12Z/14 NAM SHIFT THE
SHORTWAVE ACROSS THE CWA AND THE 12Z/14 GFS IS SLOWER WITH MOVING
THE SHORTWAVE OUT OF THE REGION...THE 00Z/14 ECMWF IS ABOUT 12 HOURS
FASTER/...BUT THE AREA WILL BECOME INCREASINGLY UNDER THE INFLUENCE
OF A 1030MB OR GREATER SFC HIGH MOVING IN FROM THE NW. WITH A SFC
TROUGH HANGING BACK ACROSS LAKE SUPERIOR FROM THE EARLIER SFC
LOW...N-NW WINDS SNOWBELTS WILL BE FAVORED FOR THE LES. THINK THAT
LES WILL END BY THU MORNING IF ECMWF VERIFIES OR BE THU EVENING IF
THE GFS PANS OUT.
FOR SNOWFALL AMOUNTS...HAVE ACCUMULATIONS MON NIGHT THROUGH TUE OF
3-5 INCHES FROM IRONWOOD TO COPPER HARBOR AND OVER NERN BARAGA
COUNTY. ELSEWHERE THROUGH TUE...HAVE 0.5-1.0 INCHES NEAR LAKE
MICHIGAN AND 1-3 INCHES OVER THE NCENTRAL
/IRON...DICKINSON...MARQUETTE COUNTIES PRIMARILY/. THEN FOR
LES TUE NIGHT AND WED...HAVE AMOUNTS RANGING FROM 3-6 INCHES NEAR
LAKE SUPERIOR TO JUST A TRACE SCENTRAL. WILL CONTINUE TO DISCUSS
AMOUNTS IN THE HWO.
WITH HIGH PRESSURE IN CONTROL THROUGH AT LEAST FRI...WARMER /HIGHS
IN THE UPPER 20S TO AROUND 30/ AND DRY CONDITIONS ARE EXPECTED. FOR
THE WEEKEND...SAT SHOULD CONTINUE TO BE DRY WITH SIMILAR TEMPS TO
SAT...BUT MODELS REALLY DIVERGE ON SOLUTIONS FOR THE WEEKEND. THE
LATEST GFS CONTINUES TO SHOW A STRONG SHORTWAVE TROUGH MOVING
THROUGH THE REGION SAT NIGHT AND SUN WHILE THE ECMWF CONTINUES TO
KEEP UPPER LEVEL ENERGY SPLIT BETWEEN A STRONGER SYSTEM MOVING
ACROSS THE SRN CONUS AND A SHORTWAVE MOVING ACROSS NRN CANADA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 153 PM EST SUN DEC 14 2014
IFR TO VLIFR CEILINGS AND VIS REMAIN UNDER A STRONG INVERSION ACROSS
MUCH OF N MN/WI/AND UPPER MI. THERE ARE SOME EXCEPTIONS AS DOWNSLOPE
WINDS AT IWD HAS HELPED THEM STAY MAINLY MVFR THROUGH MUCH OF THE
DAY. IF ANY MIXING DOES OCCUR IT WILL BE PRIOR TO 22Z. AFTER THAT
ALL SITES WILL LIKELY COME IN AS VLIFR TO LIFR AS INCREASED MOISTURE
PUSHES IN FROM MN/WI...WITH IWD BEING THE SLOWEST TO RESPOND. A
BETTER CHANCE OF LIGHT RAIN/DRIZZLE WILL SLIDE INTO IWD AND CMX BY
LATE MORNING...BEFORE PUSHING E TO SAW LATE IN THE DAY AS LOW
PRESSURE MOVES ACROSS W LAKE SUPERIOR DURING THE AFTERNOON HOURS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 304 PM EST SUN DEC 14 2014
PATCHY FOG HAS BEEN REPORTED BY SEVERAL BOATS OPERATING ACROSS LAKE
SUPERIOR TODAY. THIS WILL CONTINUE TO BE THE CASE THROUGH THE DAY
MONDAY. A LOW ACROSS MINNESOTA WILL PUSH OVER W LAKE SUPERIOR MONDAY
AFTERNOON...AND THEN E LAKE SUPERIOR MONDAY EVENING /WITH FOG
DIMINISHING/. THIS WILL BE WHILE THE S END OF THE TROUGH SHIFTS FROM
KANSAS TO IOWA MONDAY...AND LOWER MICHIGAN AND THE LOWER GREAT LAKES
TUESDAY INTO TUESDAY NIGHT. EXPECT N-NW WINDS OF 20-30KTS LATE
MONDAY EVENING INTO EARLY TUESDAY EVENING. A FEW GALES TO 35KTS WILL
BE POSSIBLE.
A WEAKENING TROUGH WILL LINGER ACROSS LAKE SUPERIOR THROUGH
WEDNESDAY. LARGE HIGH PRESSURE STRETCHING FROM MANITOBA THROUGH THE
N PLAINS WILL REMAIN NEARLY STATIONARY MONDAY NIGHT THROUGH
WEDNESDAY...BEFORE SLOWLY DRIFTING ACROSS MINNESOTA AND ONTARIO
WEDNESDAY NIGHT AND THURSDAY...AND THE ENTIRE UPPER GREAT LAKES
REGION THURSDAY NIGHT INTO FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR LMZ221-248-
250.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...KF
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
304 PM EST SUN DEC 14 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 458 AM EST SUN DEC 14 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SPLIT FLOW PATTERN ACROSS
NORTH AMERICA WITH AN UNSEASONABLY STRONG RIDGE FROM THE MS
VALLEY INTO THE WRN GREAT LAKES DOWNSTREAM FROM A TROUGH ACROSS THE
ROCKIES. AT THE SFC..SRLY WINDS WERE INCREASING FROM THE CENTRAL
PLAINS TOWARD THE UPPER MS VALLEY AHEAD OF A TROUGH FROM CENTRAL
SOUTH DAKOTA INTO WRN NEBRASKA. THE SRLY FLOW AND LOW LEVEL MOISTURE
ADVECTION HAS PUSHED DEWPOINTS TO NEAR 40F FROM CENTRAL MN AND NW WI
TO WRN UPPER MI AND INTO THE MID 30S THROUGH CNTRL UPPER MI. A
PERSISTENT LOW STRATUS DECK HAS HELPED KEEP FOG FROM BECOMING AS
DENSE OVER UPPER MI COMPARED TO LOCATIONS OVER WI.
THERE REMAINS ONLY WEAK IF ANY FORCING FOR UPWARD MOTION OVER UPPER
MI TODAY AS THE AREA REMAINS NEAR THE MID/UPPER LEVEL RIDGE AXIS.
NEVERTHELESS...THE POTENTIAL FOR DRIZZLE SPREADING ACROSS THE AREA
REMAINS AS SOME WEAK UPWARD MOTION IS EXPECTED ABOVE THE THICKENING
LOW LEVEL MOISTURE AHEAD OF THE TROUGH SLIDING INTO THE UPPER MS
VALLEY. DRIZZLE CHANCES WILL INCREASE TOWARD EVENING AS AN AREA OF
290K ISENTROPIC ASCENT IS FORECAST TO MOVE THROUGH UPPER MI...PER
NAM/GFS. IN ADDITION...MELTING SNOW WILL ADD ADDITIONAL MOISTURE TO
SUPPORT DEVELOPMENT OF AREAS OF DENSE FOG. HOWEVER...DIURNAL WARMING
SHOULD BE JUST ENOUGH TO REDUCE THE RISK FOR MORE WIDESPREAD DENSE
FOG. TONIGHT...DENSE FOG WILL BE A BETTER POSSIBILITY WITH DIURNAL
COOING AS DEWPOINTS INTO THE UPPER 30S PREVAIL ACROSS THE AREA. THE
THE POTENTIAL FOR ACCUMULATING PCPN WILL INCREASE LATE TONIGHT OVER
THE WEST WITH DEEPER MOISTURE ARRIVING AHEAD OF THE SFC TROUGH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 257 AM EST SUN DEC 14 2014
AFTER A WARM START TO THE LONG TERM PERIOD...A RETURN TO MORE
NORMAL MID DECEMBER TEMPERATURES IS IN STORE FOR TUESDAY AND
CONTINUING THROUGH MUCH OF THE REST OF THE WORK WEEK. ON MONDAY
MORNING...THE ANOMALOUS UPPER RIDGE WILL BE LOCATED OVER THE LOWER
GREAT LAKES REGION AND QUICKLY SHIFTING EAST INTO THE NEW ENGLAND
STATES. MEANWHILE...TWO SHORTWAVES WILL BE NEARING THE AREA AND
WILL BE THE FOCUS FOR THE FIRST HALF OF THE WORK WEEK. FIRST...THE
SOUTHERN STREAM SHORTWAVE WILL BE LOCATED IN EASTERN KANSAS AT 12Z
MONDAY AND WILL BE DRIVING THE 1001MB SURFACE LOW LOCATED IN NEARLY
THE SAME LOCATION. FROM THAT SURFACE LOW...A 1006MB TROUGH WILL
EXTEND NORTHEAST THROUGH EASTERN MINNESOTA AND INTO WESTERN LAKE
SUPERIOR. AT THAT SAME TIME...A SECONDARY SHORTWAVE WILL BE DIVING
SOUTHEAST THROUGH MANITOBA. AS THE SHORTWAVE AND SURFACE LOW LIFT
NORTHEAST TOWARDS CHICAGO BY MONDAY EVENING...THE ELONGATED TROUGH
WILL SLOWLY SHIFT EAST OUT OF WESTERN LAKE SUPERIOR AND INTO THE
WESTERN U.P. AHEAD OF THE TROUGH...THE WARM/MOIST LOW LEVEL AIR
WILL CONTINUE TO PRODUCE LOW CLOUDS...DRIZZLE...AND FOG (ALTHOUGH
THERE COULD BE PERIODS OF LIGHT RAIN SHOWERS UNDER THE WEAK WARM AIR
ADVECTION AND DEEPER MOISTURE NEAR THE TROUGH AXIS). SURFACE
TEMPERATURES ON MONDAY WILL LIKELY BE FAIRLY STEADY IN THE UPPER
30S AND LOWER 40S.
HEADING INTO MONDAY NIGHT...THE SURFACE LOW AND SOUTHERN STREAM
SHORTWAVE WILL BE SLIDING INTO LOWER MICHIGAN...WHILE THE NORTHERN
STREAM SHORTWAVE BECOMES CLOSE ENOUGH TO START INTERACTING WITH
SOUTHERN SHORTWAVE. THIS WILL HELP SHIFT THE SURFACE AND LOW LEVEL
TROUGH EAST ACROSS UPPER MICHIGAN THROUGH THE NIGHT...AND BRING
COLDER LOW LEVEL AIR INTO THE AREA. OVERALL...MODELS ARE FAIRLY
CONSISTENT IN THE IDEA OF THAT COLD AIR SWITCHING THE RAIN TO SNOW
FROM NORTHWEST TO SOUTHEAST MONDAY NIGHT INTO TUESDAY MORNING.
FIRST...HAPPENING IN THE KIWD/KCMX AREA BETWEEN 02-06Z TUESDAY AND
THEN KSAW/KIMT AROUND 09Z AND AREAS OVER THE SOUTHEAST BY 18Z
TUESDAY. WITH THOSE SHORTWAVE STARTING TO INTERACT MONDAY
NIGHT...AIDING THE TIGHTENING LOW-MID LEVEL FGEN...WOULD EXPECT A
PERIOD OF MODERATE PRECIPITATION OVER WESTERN LAKE SUPERIOR AND
WESTERN UPPER MICHIGAN ON MONDAY NIGHT. SNOWFALL AMOUNTS FOR THAT
PERIOD WILL LIKELY DEPEND ON THE TIMING OF THE CHANGE OVER...BUT
WITH THE GOING TIMING WOULD EXPECT TO SEE 1-3IN FROM HERMAN TO
WATERSMEET AND WEST BY DAYBREAK TUESDAY. FARTHER EAST...THAT
DELAYED ARRIVAL OF THE COLDER AIR WILL KEEP MORE OF THE
PRECIPITATION AS RAIN BEFORE SWITCHING TO SNOW. WHEN FACTORING IN
ADDITIONAL SNOW FOR TUESDAY...MAY NEED AN ADVISORY FOR THOSE AREAS
OVER THE WEST AND WILL CONTINUE TO INCLUDE MODERATE SNOWFALL MENTION
IN THE HWO.
HEADING INTO TUESDAY...THE SURFACE LOW AND SHORTWAVE WILL SHIFT EAST
THROUGH THE LOWER GREAT LAKES AND REDUCE THE DIRECT INTERACTION OF
IT WITH THE SECONDARY SHORTWAVE NOW SLIDING SOUTH THROUGH WESTERN
LAKE SUPERIOR AND THE MINNESOTA ARROWHEAD. WHILE THIS WILL LIKELY
WEAKEN THE SYNOPTICLY FORCED PRECIPITATION...THE COLDER AIR SURGING
OVER LAKE SUPERIOR ON TUESDAY (850MB TEMPS FALLING TO AROUND -14C
OVER THE WESTERN LAKE) SHOULD LEAD TO A TRANSITION TO LAKE
ENHANCED/EFFECT SNOW OVER THE WEST INITIALLY AND THEN SHIFTING EAST
ACROSS THE REST OF THE AREA BY EVENING. CONFIDENCE DOES BEGIN TO
WAVER SOME ON TUESDAY AND CONTINUE INTO WEDNESDAY AS THE TWO
SHORTWAVE INTERACT WITH EACH OTHER OVER THE GREAT LAKES REGION.
THIS LEADS TO DIFFERENCES IN THE EXACT MODEL SOLUTIONS...BUT THE
GENERAL IDEA IS FOR THE SURFACE LOW TO CONTINUE EAST...LEAVING A
TROUGH STRETCHED WEST-NORTHWEST ACROSS LAKE SUPERIOR ON TUESDAY
AFTERNOON/EVENING UNTIL THE TRAILING SHORTWAVE CAN SLIDE IT SOUTH
WEDNESDAY. THE 00Z GFS DOES DIFFER FROM THIS IDEA AND LINGERS THE
TROUGH OVER THE UPPER GREAT LAKES UNTIL THURSDAY MORNING...WHILE THE
00Z ECMWF CAME IN A LITTLE SLOWER BUT NOT AS DELAYED AS THE GFS.
WILL FOLLOW THE GENERAL CONSENSUS AT THIS POINT AND HAVE IT MOVING
SOUTH ON TUESDAY NIGHT INTO WEDNESDAY. THEREFORE...SHOULD SEE A
PERIOD OF NORTHERLY FLOW LAKE EFFECT SPREADING ACROSS THE AREA ON
TUESDAY INTO TUESDAY NIGHT FROM WEST TO EAST AND CONTINUING INTO
WEDNESDAY. UNTIL THE COLDER AIR CAN MOVE INTO THE AREA LATER
TUESDAY AFTERNOON AND NIGHT...EXPECT THE LAKE ENHANCED PRECIPITATION
INTENSITY TO BE LIMITED TO THE WEST HALF AND WHERE IT SNOWS THE
RATIOS WILL BE ON THE LOW END (AROUND 12-1). AS THAT COLDER AIR
MOVES IN...THE CLOUD LAYER WILL NOSE INTO THE DGZ AND INCREASE THE
RATIOS...BUT THE AREA WILL ALSO START TO SEE THE AFFECT OF THE HIGH
BUILDING SOUTH INTO SOUTHERN CANADA AND THE NORTHERN PLAINS. THAT
WILL STRENGTHEN THE INVERSION AROUND 5KFT AND HELP LIMIT THE
STRENGTH OF THE LAKE EFFECT PRECIPITATION. WHILE MUCH OF THE
FORECAST DEPENDS ON THE TIMING OF THAT SURFACE TROUGH DROPPING
ACROSS THE AREA...STILL WOULD EXPECT MANY LOCATIONS IN THE NORTHERLY
WIND SNOW BELTS TO SEE A COUPLE TO SEVERAL INCHES OF LAKE
ENHANCED/EFFECT SNOW TUESDAY AFTERNOON INTO WEDNESDAY. WILL
ALSO HIGHLIGHT THIS POTENTIAL IN THE HWO AS SOME AREAS MAY SEE
ADVISORY SNOWFALL.
BEHIND THE SURFACE TROUGH...EXPECT THE LAKE EFFECT TO DIMINISH
WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING AS THE AREA OF HIGH
PRESSURE BEGINS TO SLIDE SOUTHEAST INTO THE UPPER GREAT LAKES
REGION. WARMING TEMPERATURES ALOFT WILL ARRIVE WITH UPPER RIDGE AND
LEAD TO A QUIET END TO THE WORK WEEK AND LIKELY INTO NEXT WEEKEND.
MODELS ARE FAIRLY CONSISTENT ON THE HIGH REMAINING OVER THE UPPER
GREAT LAKES REGION THROUGH THIS PERIOD. AS FOR TEMPERATURES...EXPECT
HIGHS IN THE MID-UPPER 20S FOR THE END OF THE WORK WEEK THAT MAY TRY
TO NOSE INTO THE LOWER 30S FOR NEXT WEEKEND (WHICH WOULD BE AROUND 5
DEGREES ABOVE NORMAL FOR THAT TIME OF DECEMBER).
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 153 PM EST SUN DEC 14 2014
IFR TO VLIFR CEILINGS AND VIS REMAIN UNDER A STRONG INVERSION ACROSS
MUCH OF N MN/WI/AND UPPER MI. THERE ARE SOME EXCEPTIONS AS DOWNSLOPE
WINDS AT IWD HAS HELPED THEM STAY MAINLY MVFR THROUGH MUCH OF THE
DAY. IF ANY MIXING DOES OCCUR IT WILL BE PRIOR TO 22Z. AFTER THAT
ALL SITES WILL LIKELY COME IN AS VLIFR TO LIFR AS INCREASED MOISTURE
PUSHES IN FROM MN/WI...WITH IWD BEING THE SLOWEST TO RESPOND. A
BETTER CHANCE OF LIGHT RAIN/DRIZZLE WILL SLIDE INTO IWD AND CMX BY
LATE MORNING...BEFORE PUSHING E TO SAW LATE IN THE DAY AS LOW
PRESSURE MOVES ACROSS W LAKE SUPERIOR DURING THE AFTERNOON HOURS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 304 PM EST SUN DEC 14 2014
PATCHY FOG HAS BEEN REPORTED BY SEVERAL BOATS OPERATING ACROSS LAKE
SUPERIOR TODAY. THIS WILL CONTINUE TO BE THE CASE THROUGH THE DAY
MONDAY. A LOW ACROSS MINNESOTA WILL PUSH OVER W LAKE SUPERIOR MONDAY
AFTERNOON...AND THEN E LAKE SUPERIOR MONDAY EVENING /WITH FOG
DIMINISHING/. THIS WILL BE WHILE THE S END OF THE TROUGH SHIFTS FROM
KANSAS TO IOWA MONDAY...AND LOWER MICHIGAN AND THE LOWER GREAT LAKES
TUESDAY INTO TUESDAY NIGHT. EXPECT N-NW WINDS OF 20-30KTS LATE
MONDAY EVENING INTO EARLY TUESDAY EVENING. A FEW GALES TO 35KTS WILL
BE POSSIBLE.
A WEAKENING TROUGH WILL LINGER ACROSS LAKE SUPERIOR THROUGH
WEDNESDAY. LARGE HIGH PRESSURE STRETCHING FROM MANITOBA THROUGH THE
N PLAINS WILL REMAIN NEARLY STATIONARY MONDAY NIGHT THROUGH
WEDNESDAY...BEFORE SLOWLY DRIFTING ACROSS MINNESOTA AND ONTARIO
WEDNESDAY NIGHT AND THURSDAY...AND THE ENTIRE UPPER GREAT LAKES
REGION THURSDAY NIGHT INTO FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR LMZ221-248-
250.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...KF
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
154 PM EST SUN DEC 14 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 458 AM EST SUN DEC 14 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SPLIT FLOW PATTERN ACROSS
NORTH AMERICA WITH AN UNSEASONABLY STRONG RIDGE FROM THE MS
VALLEY INTO THE WRN GREAT LAKES DOWNSTREAM FROM A TROUGH ACROSS THE
ROCKIES. AT THE SFC..SRLY WINDS WERE INCREASING FROM THE CENTRAL
PLAINS TOWARD THE UPPER MS VALLEY AHEAD OF A TROUGH FROM CENTRAL
SOUTH DAKOTA INTO WRN NEBRASKA. THE SRLY FLOW AND LOW LEVEL MOISTURE
ADVECTION HAS PUSHED DEWPOINTS TO NEAR 40F FROM CENTRAL MN AND NW WI
TO WRN UPPER MI AND INTO THE MID 30S THROUGH CNTRL UPPER MI. A
PERSISTENT LOW STRATUS DECK HAS HELPED KEEP FOG FROM BECOMING AS
DENSE OVER UPPER MI COMPARED TO LOCATIONS OVER WI.
THERE REMAINS ONLY WEAK IF ANY FORCING FOR UPWARD MOTION OVER UPPER
MI TODAY AS THE AREA REMAINS NEAR THE MID/UPPER LEVEL RIDGE AXIS.
NEVERTHELESS...THE POTENTIAL FOR DRIZZLE SPREADING ACROSS THE AREA
REMAINS AS SOME WEAK UPWARD MOTION IS EXPECTED ABOVE THE THICKENING
LOW LEVEL MOISTURE AHEAD OF THE TROUGH SLIDING INTO THE UPPER MS
VALLEY. DRIZZLE CHANCES WILL INCREASE TOWARD EVENING AS AN AREA OF
290K ISENTROPIC ASCENT IS FORECAST TO MOVE THROUGH UPPER MI...PER
NAM/GFS. IN ADDITION...MELTING SNOW WILL ADD ADDITIONAL MOISTURE TO
SUPPORT DEVELOPMENT OF AREAS OF DENSE FOG. HOWEVER...DIURNAL WARMING
SHOULD BE JUST ENOUGH TO REDUCE THE RISK FOR MORE WIDESPREAD DENSE
FOG. TONIGHT...DENSE FOG WILL BE A BETTER POSSIBILITY WITH DIURNAL
COOING AS DEWPOINTS INTO THE UPPER 30S PREVAIL ACROSS THE AREA. THE
THE POTENTIAL FOR ACCUMULATING PCPN WILL INCREASE LATE TONIGHT OVER
THE WEST WITH DEEPER MOISTURE ARRIVING AHEAD OF THE SFC TROUGH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 257 AM EST SUN DEC 14 2014
AFTER A WARM START TO THE LONG TERM PERIOD...A RETURN TO MORE
NORMAL MID DECEMBER TEMPERATURES IS IN STORE FOR TUESDAY AND
CONTINUING THROUGH MUCH OF THE REST OF THE WORK WEEK. ON MONDAY
MORNING...THE ANOMALOUS UPPER RIDGE WILL BE LOCATED OVER THE LOWER
GREAT LAKES REGION AND QUICKLY SHIFTING EAST INTO THE NEW ENGLAND
STATES. MEANWHILE...TWO SHORTWAVES WILL BE NEARING THE AREA AND
WILL BE THE FOCUS FOR THE FIRST HALF OF THE WORK WEEK. FIRST...THE
SOUTHERN STREAM SHORTWAVE WILL BE LOCATED IN EASTERN KANSAS AT 12Z
MONDAY AND WILL BE DRIVING THE 1001MB SURFACE LOW LOCATED IN NEARLY
THE SAME LOCATION. FROM THAT SURFACE LOW...A 1006MB TROUGH WILL
EXTEND NORTHEAST THROUGH EASTERN MINNESOTA AND INTO WESTERN LAKE
SUPERIOR. AT THAT SAME TIME...A SECONDARY SHORTWAVE WILL BE DIVING
SOUTHEAST THROUGH MANITOBA. AS THE SHORTWAVE AND SURFACE LOW LIFT
NORTHEAST TOWARDS CHICAGO BY MONDAY EVENING...THE ELONGATED TROUGH
WILL SLOWLY SHIFT EAST OUT OF WESTERN LAKE SUPERIOR AND INTO THE
WESTERN U.P. AHEAD OF THE TROUGH...THE WARM/MOIST LOW LEVEL AIR
WILL CONTINUE TO PRODUCE LOW CLOUDS...DRIZZLE...AND FOG (ALTHOUGH
THERE COULD BE PERIODS OF LIGHT RAIN SHOWERS UNDER THE WEAK WARM AIR
ADVECTION AND DEEPER MOISTURE NEAR THE TROUGH AXIS). SURFACE
TEMPERATURES ON MONDAY WILL LIKELY BE FAIRLY STEADY IN THE UPPER
30S AND LOWER 40S.
HEADING INTO MONDAY NIGHT...THE SURFACE LOW AND SOUTHERN STREAM
SHORTWAVE WILL BE SLIDING INTO LOWER MICHIGAN...WHILE THE NORTHERN
STREAM SHORTWAVE BECOMES CLOSE ENOUGH TO START INTERACTING WITH
SOUTHERN SHORTWAVE. THIS WILL HELP SHIFT THE SURFACE AND LOW LEVEL
TROUGH EAST ACROSS UPPER MICHIGAN THROUGH THE NIGHT...AND BRING
COLDER LOW LEVEL AIR INTO THE AREA. OVERALL...MODELS ARE FAIRLY
CONSISTENT IN THE IDEA OF THAT COLD AIR SWITCHING THE RAIN TO SNOW
FROM NORTHWEST TO SOUTHEAST MONDAY NIGHT INTO TUESDAY MORNING.
FIRST...HAPPENING IN THE KIWD/KCMX AREA BETWEEN 02-06Z TUESDAY AND
THEN KSAW/KIMT AROUND 09Z AND AREAS OVER THE SOUTHEAST BY 18Z
TUESDAY. WITH THOSE SHORTWAVE STARTING TO INTERACT MONDAY
NIGHT...AIDING THE TIGHTENING LOW-MID LEVEL FGEN...WOULD EXPECT A
PERIOD OF MODERATE PRECIPITATION OVER WESTERN LAKE SUPERIOR AND
WESTERN UPPER MICHIGAN ON MONDAY NIGHT. SNOWFALL AMOUNTS FOR THAT
PERIOD WILL LIKELY DEPEND ON THE TIMING OF THE CHANGE OVER...BUT
WITH THE GOING TIMING WOULD EXPECT TO SEE 1-3IN FROM HERMAN TO
WATERSMEET AND WEST BY DAYBREAK TUESDAY. FARTHER EAST...THAT
DELAYED ARRIVAL OF THE COLDER AIR WILL KEEP MORE OF THE
PRECIPITATION AS RAIN BEFORE SWITCHING TO SNOW. WHEN FACTORING IN
ADDITIONAL SNOW FOR TUESDAY...MAY NEED AN ADVISORY FOR THOSE AREAS
OVER THE WEST AND WILL CONTINUE TO INCLUDE MODERATE SNOWFALL MENTION
IN THE HWO.
HEADING INTO TUESDAY...THE SURFACE LOW AND SHORTWAVE WILL SHIFT EAST
THROUGH THE LOWER GREAT LAKES AND REDUCE THE DIRECT INTERACTION OF
IT WITH THE SECONDARY SHORTWAVE NOW SLIDING SOUTH THROUGH WESTERN
LAKE SUPERIOR AND THE MINNESOTA ARROWHEAD. WHILE THIS WILL LIKELY
WEAKEN THE SYNOPTICLY FORCED PRECIPITATION...THE COLDER AIR SURGING
OVER LAKE SUPERIOR ON TUESDAY (850MB TEMPS FALLING TO AROUND -14C
OVER THE WESTERN LAKE) SHOULD LEAD TO A TRANSITION TO LAKE
ENHANCED/EFFECT SNOW OVER THE WEST INITIALLY AND THEN SHIFTING EAST
ACROSS THE REST OF THE AREA BY EVENING. CONFIDENCE DOES BEGIN TO
WAVER SOME ON TUESDAY AND CONTINUE INTO WEDNESDAY AS THE TWO
SHORTWAVE INTERACT WITH EACH OTHER OVER THE GREAT LAKES REGION.
THIS LEADS TO DIFFERENCES IN THE EXACT MODEL SOLUTIONS...BUT THE
GENERAL IDEA IS FOR THE SURFACE LOW TO CONTINUE EAST...LEAVING A
TROUGH STRETCHED WEST-NORTHWEST ACROSS LAKE SUPERIOR ON TUESDAY
AFTERNOON/EVENING UNTIL THE TRAILING SHORTWAVE CAN SLIDE IT SOUTH
WEDNESDAY. THE 00Z GFS DOES DIFFER FROM THIS IDEA AND LINGERS THE
TROUGH OVER THE UPPER GREAT LAKES UNTIL THURSDAY MORNING...WHILE THE
00Z ECMWF CAME IN A LITTLE SLOWER BUT NOT AS DELAYED AS THE GFS.
WILL FOLLOW THE GENERAL CONSENSUS AT THIS POINT AND HAVE IT MOVING
SOUTH ON TUESDAY NIGHT INTO WEDNESDAY. THEREFORE...SHOULD SEE A
PERIOD OF NORTHERLY FLOW LAKE EFFECT SPREADING ACROSS THE AREA ON
TUESDAY INTO TUESDAY NIGHT FROM WEST TO EAST AND CONTINUING INTO
WEDNESDAY. UNTIL THE COLDER AIR CAN MOVE INTO THE AREA LATER
TUESDAY AFTERNOON AND NIGHT...EXPECT THE LAKE ENHANCED PRECIPITATION
INTENSITY TO BE LIMITED TO THE WEST HALF AND WHERE IT SNOWS THE
RATIOS WILL BE ON THE LOW END (AROUND 12-1). AS THAT COLDER AIR
MOVES IN...THE CLOUD LAYER WILL NOSE INTO THE DGZ AND INCREASE THE
RATIOS...BUT THE AREA WILL ALSO START TO SEE THE AFFECT OF THE HIGH
BUILDING SOUTH INTO SOUTHERN CANADA AND THE NORTHERN PLAINS. THAT
WILL STRENGTHEN THE INVERSION AROUND 5KFT AND HELP LIMIT THE
STRENGTH OF THE LAKE EFFECT PRECIPITATION. WHILE MUCH OF THE
FORECAST DEPENDS ON THE TIMING OF THAT SURFACE TROUGH DROPPING
ACROSS THE AREA...STILL WOULD EXPECT MANY LOCATIONS IN THE NORTHERLY
WIND SNOW BELTS TO SEE A COUPLE TO SEVERAL INCHES OF LAKE
ENHANCED/EFFECT SNOW TUESDAY AFTERNOON INTO WEDNESDAY. WILL
ALSO HIGHLIGHT THIS POTENTIAL IN THE HWO AS SOME AREAS MAY SEE
ADVISORY SNOWFALL.
BEHIND THE SURFACE TROUGH...EXPECT THE LAKE EFFECT TO DIMINISH
WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING AS THE AREA OF HIGH
PRESSURE BEGINS TO SLIDE SOUTHEAST INTO THE UPPER GREAT LAKES
REGION. WARMING TEMPERATURES ALOFT WILL ARRIVE WITH UPPER RIDGE AND
LEAD TO A QUIET END TO THE WORK WEEK AND LIKELY INTO NEXT WEEKEND.
MODELS ARE FAIRLY CONSISTENT ON THE HIGH REMAINING OVER THE UPPER
GREAT LAKES REGION THROUGH THIS PERIOD. AS FOR TEMPERATURES...EXPECT
HIGHS IN THE MID-UPPER 20S FOR THE END OF THE WORK WEEK THAT MAY TRY
TO NOSE INTO THE LOWER 30S FOR NEXT WEEKEND (WHICH WOULD BE AROUND 5
DEGREES ABOVE NORMAL FOR THAT TIME OF DECEMBER).
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 153 PM EST SUN DEC 14 2014
IFR TO VLIFR CEILINGS AND VIS REMAIN UNDER A STRONG INVERSION ACROSS
MUCH OF N MN/WI/AND UPPER MI. THERE ARE SOME EXCEPTIONS AS DOWNSLOPE
WINDS AT IWD HAS HELPED THEM STAY MAINLY MVFR THROUGH MUCH OF THE
DAY. IF ANY MIXING DOES OCCUR IT WILL BE PRIOR TO 22Z. AFTER THAT
ALL SITES WILL LIKELY COME IN AS VLIFR TO LIFR AS INCREASED MOISTURE
PUSHES IN FROM MN/WI...WITH IWD BEING THE SLOWEST TO RESPOND. A
BETTER CHANCE OF LIGHT RAIN/DRIZZLE WILL SLIDE INTO IWD AND CMX BY
LATE MORNING...BEFORE PUSHING E TO SAW LATE IN THE DAY AS LOW
PRESSURE MOVES ACROSS W LAKE SUPERIOR DURING THE AFTERNOON HOURS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 511 AM EST SUN DEC 14 2014
A RIDGE ACROSS THE UPPER GREAT LAKES WILL SLOWLY SHIFT TO THE LOWER
GREAT LAKES SUNDAY INTO MONDAY. LOOK FOR AN ELONGATED AREA OF LOW
PRESSURE ACROSS THE PLAINS STATES SUNDAY MORNING TO PUSH ACROSS LAKE
SUPERIOR LATE SUNDAY NIGHT INTO MONDAY...AS THE S END OF THE TROUGH
DEEPENS ACROSS IOWA ON MONDAY. THE LOW WILL PUSH ACROSS LOWER
MICHIGAN ON TUESDAY...AND EXIT ACROSS THE LOWER GREAT LAKES TUESDAY
NIGHT. A TIGHTENING GRADIENT BEHIND THE LOW PRES SYSTEM LATE MONDAY
NIGHT INTO TUESDAY IS EXPECTED TO BRING NORTH WINDS GUSTING TO 30
KNOTS WITH A FEW GALE FORCE GUSTS TO 35 KNOTS.
WINDS WILL DIMINISH FROM WED INTO WED NIGHT AS THE LOW MOVES AWAY
AND HIGH PRESSURE HIGH PRESSURE BUILDS TOWARD THE WRN LAKES FROM THE
PLAINS. WINDS WILL THEN REMAIN AT OR BELOW 20 KNOTS THU AS THE HIGH
SETTLES OVER THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR LMZ221-248-
250.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...KF
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
657 AM EST SUN DEC 14 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 458 AM EST SUN DEC 14 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SPLIT FLOW PATTERN ACROSS
NORTH AMERICA WITH AN UNSEASONABLY STRONG RIDGE FROM THE MS
VALLEY INTO THE WRN GREAT LAKES DOWNSTREAM FROM A TROUGH ACROSS THE
ROCKIES. AT THE SFC..SRLY WINDS WERE INCREASING FROM THE CENTRAL
PLAINS TOWARD THE UPPER MS VALLEY AHEAD OF A TROUGH FROM CENTRAL
SOUTH DAKOTA INTO WRN NEBRASKA. THE SRLY FLOW AND LOW LEVEL MOISTURE
ADVECTION HAS PUSHED DEWPOINTS TO NEAR 40F FROM CENTRAL MN AND NW WI
TO WRN UPPER MI AND INTO THE MID 30S THROUGH CNTRL UPPER MI. A
PERSISTENT LOW STRATUS DECK HAS HELPED KEEP FOG FROM BECOMING AS
DENSE OVER UPPER MI COMPARED TO LOCATIONS OVER WI.
THERE REMAINS ONLY WEAK IF ANY FORCING FOR UPWARD MOTION OVER UPPER
MI TODAY AS THE AREA REMAINS NEAR THE MID/UPPER LEVEL RIDGE AXIS.
NEVERTHELESS...THE POTENTIAL FOR DRIZZLE SPREADING ACROSS THE AREA
REMAINS AS SOME WEAK UPWARD MOTION IS EXPECTED ABOVE THE THICKENING
LOW LEVEL MOISTURE AHEAD OF THE TROUGH SLIDING INTO THE UPPER MS
VALLEY. DRIZZLE CHANCES WILL INCREASE TOWARD EVENING AS AN AREA OF
290K ISENTROPIC ASCENT IS FORECAST TO MOVE THROUGH UPPER MI...PER
NAM/GFS. IN ADDITION...MELTING SNOW WILL ADD ADDITIONAL MOISTURE TO
SUPPORT DEVELOPMENT OF AREAS OF DENSE FOG. HOWEVER...DIURNAL WARMING
SHOULD BE JUST ENOUGH TO REDUCE THE RISK FOR MORE WIDESPREAD DENSE
FOG. TONIGHT...DENSE FOG WILL BE A BETTER POSSIBILITY WITH DIURNAL
COOING AS DEWPOINTS INTO THE UPPER 30S PREVAIL ACROSS THE AREA. THE
THE POTENTIAL FOR ACCUMULATING PCPN WILL INCREASE LATE TONIGHT OVER
THE WEST WITH DEEPER MOISTURE ARRIVING AHEAD OF THE SFC TROUGH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 257 AM EST SUN DEC 14 2014
AFTER A WARM START TO THE LONG TERM PERIOD...A RETURN TO MORE
NORMAL MID DECEMBER TEMPERATURES IS IN STORE FOR TUESDAY AND
CONTINUING THROUGH MUCH OF THE REST OF THE WORK WEEK. ON MONDAY
MORNING...THE ANOMALOUS UPPER RIDGE WILL BE LOCATED OVER THE LOWER
GREAT LAKES REGION AND QUICKLY SHIFTING EAST INTO THE NEW ENGLAND
STATES. MEANWHILE...TWO SHORTWAVES WILL BE NEARING THE AREA AND
WILL BE THE FOCUS FOR THE FIRST HALF OF THE WORK WEEK. FIRST...THE
SOUTHERN STREAM SHORTWAVE WILL BE LOCATED IN EASTERN KANSAS AT 12Z
MONDAY AND WILL BE DRIVING THE 1001MB SURFACE LOW LOCATED IN NEARLY
THE SAME LOCATION. FROM THAT SURFACE LOW...A 1006MB TROUGH WILL
EXTEND NORTHEAST THROUGH EASTERN MINNESOTA AND INTO WESTERN LAKE
SUPERIOR. AT THAT SAME TIME...A SECONDARY SHORTWAVE WILL BE DIVING
SOUTHEAST THROUGH MANITOBA. AS THE SHORTWAVE AND SURFACE LOW LIFT
NORTHEAST TOWARDS CHICAGO BY MONDAY EVENING...THE ELONGATED TROUGH
WILL SLOWLY SHIFT EAST OUT OF WESTERN LAKE SUPERIOR AND INTO THE
WESTERN U.P. AHEAD OF THE TROUGH...THE WARM/MOIST LOW LEVEL AIR
WILL CONTINUE TO PRODUCE LOW CLOUDS...DRIZZLE...AND FOG (ALTHOUGH
THERE COULD BE PERIODS OF LIGHT RAIN SHOWERS UNDER THE WEAK WARM AIR
ADVECTION AND DEEPER MOISTURE NEAR THE TROUGH AXIS). SURFACE
TEMPERATURES ON MONDAY WILL LIKELY BE FAIRLY STEADY IN THE UPPER
30S AND LOWER 40S.
HEADING INTO MONDAY NIGHT...THE SURFACE LOW AND SOUTHERN STREAM
SHORTWAVE WILL BE SLIDING INTO LOWER MICHIGAN...WHILE THE NORTHERN
STREAM SHORTWAVE BECOMES CLOSE ENOUGH TO START INTERACTING WITH
SOUTHERN SHORTWAVE. THIS WILL HELP SHIFT THE SURFACE AND LOW LEVEL
TROUGH EAST ACROSS UPPER MICHIGAN THROUGH THE NIGHT...AND BRING
COLDER LOW LEVEL AIR INTO THE AREA. OVERALL...MODELS ARE FAIRLY
CONSISTENT IN THE IDEA OF THAT COLD AIR SWITCHING THE RAIN TO SNOW
FROM NORTHWEST TO SOUTHEAST MONDAY NIGHT INTO TUESDAY MORNING.
FIRST...HAPPENING IN THE KIWD/KCMX AREA BETWEEN 02-06Z TUESDAY AND
THEN KSAW/KIMT AROUND 09Z AND AREAS OVER THE SOUTHEAST BY 18Z
TUESDAY. WITH THOSE SHORTWAVE STARTING TO INTERACT MONDAY
NIGHT...AIDING THE TIGHTENING LOW-MID LEVEL FGEN...WOULD EXPECT A
PERIOD OF MODERATE PRECIPITATION OVER WESTERN LAKE SUPERIOR AND
WESTERN UPPER MICHIGAN ON MONDAY NIGHT. SNOWFALL AMOUNTS FOR THAT
PERIOD WILL LIKELY DEPEND ON THE TIMING OF THE CHANGE OVER...BUT
WITH THE GOING TIMING WOULD EXPECT TO SEE 1-3IN FROM HERMAN TO
WATERSMEET AND WEST BY DAYBREAK TUESDAY. FARTHER EAST...THAT
DELAYED ARRIVAL OF THE COLDER AIR WILL KEEP MORE OF THE
PRECIPITATION AS RAIN BEFORE SWITCHING TO SNOW. WHEN FACTORING IN
ADDITIONAL SNOW FOR TUESDAY...MAY NEED AN ADVISORY FOR THOSE AREAS
OVER THE WEST AND WILL CONTINUE TO INCLUDE MODERATE SNOWFALL MENTION
IN THE HWO.
HEADING INTO TUESDAY...THE SURFACE LOW AND SHORTWAVE WILL SHIFT EAST
THROUGH THE LOWER GREAT LAKES AND REDUCE THE DIRECT INTERACTION OF
IT WITH THE SECONDARY SHORTWAVE NOW SLIDING SOUTH THROUGH WESTERN
LAKE SUPERIOR AND THE MINNESOTA ARROWHEAD. WHILE THIS WILL LIKELY
WEAKEN THE SYNOPTICLY FORCED PRECIPITATION...THE COLDER AIR SURGING
OVER LAKE SUPERIOR ON TUESDAY (850MB TEMPS FALLING TO AROUND -14C
OVER THE WESTERN LAKE) SHOULD LEAD TO A TRANSITION TO LAKE
ENHANCED/EFFECT SNOW OVER THE WEST INITIALLY AND THEN SHIFTING EAST
ACROSS THE REST OF THE AREA BY EVENING. CONFIDENCE DOES BEGIN TO
WAVER SOME ON TUESDAY AND CONTINUE INTO WEDNESDAY AS THE TWO
SHORTWAVE INTERACT WITH EACH OTHER OVER THE GREAT LAKES REGION.
THIS LEADS TO DIFFERENCES IN THE EXACT MODEL SOLUTIONS...BUT THE
GENERAL IDEA IS FOR THE SURFACE LOW TO CONTINUE EAST...LEAVING A
TROUGH STRETCHED WEST-NORTHWEST ACROSS LAKE SUPERIOR ON TUESDAY
AFTERNOON/EVENING UNTIL THE TRAILING SHORTWAVE CAN SLIDE IT SOUTH
WEDNESDAY. THE 00Z GFS DOES DIFFER FROM THIS IDEA AND LINGERS THE
TROUGH OVER THE UPPER GREAT LAKES UNTIL THURSDAY MORNING...WHILE THE
00Z ECMWF CAME IN A LITTLE SLOWER BUT NOT AS DELAYED AS THE GFS.
WILL FOLLOW THE GENERAL CONSENSUS AT THIS POINT AND HAVE IT MOVING
SOUTH ON TUESDAY NIGHT INTO WEDNESDAY. THEREFORE...SHOULD SEE A
PERIOD OF NORTHERLY FLOW LAKE EFFECT SPREADING ACROSS THE AREA ON
TUESDAY INTO TUESDAY NIGHT FROM WEST TO EAST AND CONTINUING INTO
WEDNESDAY. UNTIL THE COLDER AIR CAN MOVE INTO THE AREA LATER
TUESDAY AFTERNOON AND NIGHT...EXPECT THE LAKE ENHANCED PRECIPITATION
INTENSITY TO BE LIMITED TO THE WEST HALF AND WHERE IT SNOWS THE
RATIOS WILL BE ON THE LOW END (AROUND 12-1). AS THAT COLDER AIR
MOVES IN...THE CLOUD LAYER WILL NOSE INTO THE DGZ AND INCREASE THE
RATIOS...BUT THE AREA WILL ALSO START TO SEE THE AFFECT OF THE HIGH
BUILDING SOUTH INTO SOUTHERN CANADA AND THE NORTHERN PLAINS. THAT
WILL STRENGTHEN THE INVERSION AROUND 5KFT AND HELP LIMIT THE
STRENGTH OF THE LAKE EFFECT PRECIPITATION. WHILE MUCH OF THE
FORECAST DEPENDS ON THE TIMING OF THAT SURFACE TROUGH DROPPING
ACROSS THE AREA...STILL WOULD EXPECT MANY LOCATIONS IN THE NORTHERLY
WIND SNOW BELTS TO SEE A COUPLE TO SEVERAL INCHES OF LAKE
ENHANCED/EFFECT SNOW TUESDAY AFTERNOON INTO WEDNESDAY. WILL
ALSO HIGHLIGHT THIS POTENTIAL IN THE HWO AS SOME AREAS MAY SEE
ADVISORY SNOWFALL.
BEHIND THE SURFACE TROUGH...EXPECT THE LAKE EFFECT TO DIMINISH
WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING AS THE AREA OF HIGH
PRESSURE BEGINS TO SLIDE SOUTHEAST INTO THE UPPER GREAT LAKES
REGION. WARMING TEMPERATURES ALOFT WILL ARRIVE WITH UPPER RIDGE AND
LEAD TO A QUIET END TO THE WORK WEEK AND LIKELY INTO NEXT WEEKEND.
MODELS ARE FAIRLY CONSISTENT ON THE HIGH REMAINING OVER THE UPPER
GREAT LAKES REGION THROUGH THIS PERIOD. AS FOR TEMPERATURES...EXPECT
HIGHS IN THE MID-UPPER 20S FOR THE END OF THE WORK WEEK THAT MAY TRY
TO NOSE INTO THE LOWER 30S FOR NEXT WEEKEND (WHICH WOULD BE AROUND 5
DEGREES ABOVE NORMAL FOR THAT TIME OF DECEMBER).
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 656 AM EST SUN DEC 14 2014
WITH THE ARRIVAL OF MOISTER LOW LEVEL AIR OVER MELTING SNOW...EXPECT
CONDITIONS AT SAW/CMX TO REMAIN IN THE LIFR RANGE MUCH OF THE TIME.
THE BEST CHANCE FOR SOME VLIFR CONDITIONS WILL BE AT CMX AND SAW WITH
A MORE FAVORABLE WIND DIRECTION. DOWNSLOPE WIND COMPONENT AT IWD THAT
HAS BROUGHT CIGS UP TO MVFR SHOULD GIVE WAY TO IFR CIGS BY THIS
AFTERNOON WITH THE INFLUX OF ADDITIONAL MOISTURE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 511 AM EST SUN DEC 14 2014
A RIDGE ACROSS THE UPPER GREAT LAKES WILL SLOWLY SHIFT TO THE LOWER
GREAT LAKES SUNDAY INTO MONDAY. LOOK FOR AN ELONGATED AREA OF LOW
PRESSURE ACROSS THE PLAINS STATES SUNDAY MORNING TO PUSH ACROSS LAKE
SUPERIOR LATE SUNDAY NIGHT INTO MONDAY...AS THE S END OF THE TROUGH
DEEPENS ACROSS IOWA ON MONDAY. THE LOW WILL PUSH ACROSS LOWER
MICHIGAN ON TUESDAY...AND EXIT ACROSS THE LOWER GREAT LAKES TUESDAY
NIGHT. A TIGHTENING GRADIENT BEHIND THE LOW PRES SYSTEM LATE MONDAY
NIGHT INTO TUESDAY IS EXPECTED TO BRING NORTH WINDS GUSTING TO 30
KNOTS WITH A FEW GALE FORCE GUSTS TO 35 KNOTS.
WINDS WILL DIMINISH FROM WED INTO WED NIGHT AS THE LOW MOVES AWAY
AND HIGH PRESSURE HIGH PRESSURE BUILDS TOWARD THE WRN LAKES FROM THE
PLAINS. WINDS WILL THEN REMAIN AT OR BELOW 20 KNOTS THU AS THE HIGH
SETTLES OVER THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
513 AM EST SUN DEC 14 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 458 AM EST SUN DEC 14 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SPLIT FLOW PATTERN ACROSS
NORTH AMERICA WITH AN UNSEASONABLY STRONG RIDGE FROM THE MS
VALLEY INTO THE WRN GREAT LAKES DOWNSTREAM FROM A TROUGH ACROSS THE
ROCKIES. AT THE SFC..SRLY WINDS WERE INCREASING FROM THE CENTRAL
PLAINS TOWARD THE UPPER MS VALLEY AHEAD OF A TROUGH FROM CENTRAL
SOUTH DAKOTA INTO WRN NEBRASKA. THE SRLY FLOW AND LOW LEVEL MOISTURE
ADVECTION HAS PUSHED DEWPOINTS TO NEAR 40F FROM CENTRAL MN AND NW WI
TO WRN UPPER MI AND INTO THE MID 30S THROUGH CNTRL UPPER MI. A
PERSISTENT LOW STRATUS DECK HAS HELPED KEEP FOG FROM BECOMING AS
DENSE OVER UPPER MI COMPARED TO LOCATIONS OVER WI.
THERE REMAINS ONLY WEAK IF ANY FORCING FOR UPWARD MOTION OVER UPPER
MI TODAY AS THE AREA REMAINS NEAR THE MID/UPPER LEVEL RIDGE AXIS.
NEVERTHELESS...THE POTENTIAL FOR DRIZZLE SPREADING ACROSS THE AREA
REMAINS AS SOME WEAK UPWARD MOTION IS EXPECTED ABOVE THE THICKENING
LOW LEVEL MOISTURE AHEAD OF THE TROUGH SLIDING INTO THE UPPER MS
VALLEY. DRIZZLE CHANCES WILL INCREASE TOWARD EVENING AS AN AREA OF
290K ISENTROPIC ASCENT IS FORECAST TO MOVE THROUGH UPPER MI...PER
NAM/GFS. IN ADDITION...MELTING SNOW WILL ADD ADDITIONAL MOISTURE TO
SUPPORT DEVELOPMENT OF AREAS OF DENSE FOG. HOWEVER...DIURNAL WARMING
SHOULD BE JUST ENOUGH TO REDUCE THE RISK FOR MORE WIDESPREAD DENSE
FOG. TONIGHT...DENSE FOG WILL BE A BETTER POSSIBILITY WITH DIURNAL
COOING AS DEWPOINTS INTO THE UPPER 30S PREVAIL ACROSS THE AREA. THE
THE POTENTIAL FOR ACCUMULATING PCPN WILL INCREASE LATE TONIGHT OVER
THE WEST WITH DEEPER MOISTURE ARRIVING AHEAD OF THE SFC TROUGH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 257 AM EST SUN DEC 14 2014
AFTER A WARM START TO THE LONG TERM PERIOD...A RETURN TO MORE
NORMAL MID DECEMBER TEMPERATURES IS IN STORE FOR TUESDAY AND
CONTINUING THROUGH MUCH OF THE REST OF THE WORK WEEK. ON MONDAY
MORNING...THE ANOMALOUS UPPER RIDGE WILL BE LOCATED OVER THE LOWER
GREAT LAKES REGION AND QUICKLY SHIFTING EAST INTO THE NEW ENGLAND
STATES. MEANWHILE...TWO SHORTWAVES WILL BE NEARING THE AREA AND
WILL BE THE FOCUS FOR THE FIRST HALF OF THE WORK WEEK. FIRST...THE
SOUTHERN STREAM SHORTWAVE WILL BE LOCATED IN EASTERN KANSAS AT 12Z
MONDAY AND WILL BE DRIVING THE 1001MB SURFACE LOW LOCATED IN NEARLY
THE SAME LOCATION. FROM THAT SURFACE LOW...A 1006MB TROUGH WILL
EXTEND NORTHEAST THROUGH EASTERN MINNESOTA AND INTO WESTERN LAKE
SUPERIOR. AT THAT SAME TIME...A SECONDARY SHORTWAVE WILL BE DIVING
SOUTHEAST THROUGH MANITOBA. AS THE SHORTWAVE AND SURFACE LOW LIFT
NORTHEAST TOWARDS CHICAGO BY MONDAY EVENING...THE ELONGATED TROUGH
WILL SLOWLY SHIFT EAST OUT OF WESTERN LAKE SUPERIOR AND INTO THE
WESTERN U.P. AHEAD OF THE TROUGH...THE WARM/MOIST LOW LEVEL AIR
WILL CONTINUE TO PRODUCE LOW CLOUDS...DRIZZLE...AND FOG (ALTHOUGH
THERE COULD BE PERIODS OF LIGHT RAIN SHOWERS UNDER THE WEAK WARM AIR
ADVECTION AND DEEPER MOISTURE NEAR THE TROUGH AXIS). SURFACE
TEMPERATURES ON MONDAY WILL LIKELY BE FAIRLY STEADY IN THE UPPER
30S AND LOWER 40S.
HEADING INTO MONDAY NIGHT...THE SURFACE LOW AND SOUTHERN STREAM
SHORTWAVE WILL BE SLIDING INTO LOWER MICHIGAN...WHILE THE NORTHERN
STREAM SHORTWAVE BECOMES CLOSE ENOUGH TO START INTERACTING WITH
SOUTHERN SHORTWAVE. THIS WILL HELP SHIFT THE SURFACE AND LOW LEVEL
TROUGH EAST ACROSS UPPER MICHIGAN THROUGH THE NIGHT...AND BRING
COLDER LOW LEVEL AIR INTO THE AREA. OVERALL...MODELS ARE FAIRLY
CONSISTENT IN THE IDEA OF THAT COLD AIR SWITCHING THE RAIN TO SNOW
FROM NORTHWEST TO SOUTHEAST MONDAY NIGHT INTO TUESDAY MORNING.
FIRST...HAPPENING IN THE KIWD/KCMX AREA BETWEEN 02-06Z TUESDAY AND
THEN KSAW/KIMT AROUND 09Z AND AREAS OVER THE SOUTHEAST BY 18Z
TUESDAY. WITH THOSE SHORTWAVE STARTING TO INTERACT MONDAY
NIGHT...AIDING THE TIGHTENING LOW-MID LEVEL FGEN...WOULD EXPECT A
PERIOD OF MODERATE PRECIPITATION OVER WESTERN LAKE SUPERIOR AND
WESTERN UPPER MICHIGAN ON MONDAY NIGHT. SNOWFALL AMOUNTS FOR THAT
PERIOD WILL LIKELY DEPEND ON THE TIMING OF THE CHANGE OVER...BUT
WITH THE GOING TIMING WOULD EXPECT TO SEE 1-3IN FROM HERMAN TO
WATERSMEET AND WEST BY DAYBREAK TUESDAY. FARTHER EAST...THAT
DELAYED ARRIVAL OF THE COLDER AIR WILL KEEP MORE OF THE
PRECIPITATION AS RAIN BEFORE SWITCHING TO SNOW. WHEN FACTORING IN
ADDITIONAL SNOW FOR TUESDAY...MAY NEED AN ADVISORY FOR THOSE AREAS
OVER THE WEST AND WILL CONTINUE TO INCLUDE MODERATE SNOWFALL MENTION
IN THE HWO.
HEADING INTO TUESDAY...THE SURFACE LOW AND SHORTWAVE WILL SHIFT EAST
THROUGH THE LOWER GREAT LAKES AND REDUCE THE DIRECT INTERACTION OF
IT WITH THE SECONDARY SHORTWAVE NOW SLIDING SOUTH THROUGH WESTERN
LAKE SUPERIOR AND THE MINNESOTA ARROWHEAD. WHILE THIS WILL LIKELY
WEAKEN THE SYNOPTICLY FORCED PRECIPITATION...THE COLDER AIR SURGING
OVER LAKE SUPERIOR ON TUESDAY (850MB TEMPS FALLING TO AROUND -14C
OVER THE WESTERN LAKE) SHOULD LEAD TO A TRANSITION TO LAKE
ENHANCED/EFFECT SNOW OVER THE WEST INITIALLY AND THEN SHIFTING EAST
ACROSS THE REST OF THE AREA BY EVENING. CONFIDENCE DOES BEGIN TO
WAVER SOME ON TUESDAY AND CONTINUE INTO WEDNESDAY AS THE TWO
SHORTWAVE INTERACT WITH EACH OTHER OVER THE GREAT LAKES REGION.
THIS LEADS TO DIFFERENCES IN THE EXACT MODEL SOLUTIONS...BUT THE
GENERAL IDEA IS FOR THE SURFACE LOW TO CONTINUE EAST...LEAVING A
TROUGH STRETCHED WEST-NORTHWEST ACROSS LAKE SUPERIOR ON TUESDAY
AFTERNOON/EVENING UNTIL THE TRAILING SHORTWAVE CAN SLIDE IT SOUTH
WEDNESDAY. THE 00Z GFS DOES DIFFER FROM THIS IDEA AND LINGERS THE
TROUGH OVER THE UPPER GREAT LAKES UNTIL THURSDAY MORNING...WHILE THE
00Z ECMWF CAME IN A LITTLE SLOWER BUT NOT AS DELAYED AS THE GFS.
WILL FOLLOW THE GENERAL CONSENSUS AT THIS POINT AND HAVE IT MOVING
SOUTH ON TUESDAY NIGHT INTO WEDNESDAY. THEREFORE...SHOULD SEE A
PERIOD OF NORTHERLY FLOW LAKE EFFECT SPREADING ACROSS THE AREA ON
TUESDAY INTO TUESDAY NIGHT FROM WEST TO EAST AND CONTINUING INTO
WEDNESDAY. UNTIL THE COLDER AIR CAN MOVE INTO THE AREA LATER
TUESDAY AFTERNOON AND NIGHT...EXPECT THE LAKE ENHANCED PRECIPITATION
INTENSITY TO BE LIMITED TO THE WEST HALF AND WHERE IT SNOWS THE
RATIOS WILL BE ON THE LOW END (AROUND 12-1). AS THAT COLDER AIR
MOVES IN...THE CLOUD LAYER WILL NOSE INTO THE DGZ AND INCREASE THE
RATIOS...BUT THE AREA WILL ALSO START TO SEE THE AFFECT OF THE HIGH
BUILDING SOUTH INTO SOUTHERN CANADA AND THE NORTHERN PLAINS. THAT
WILL STRENGTHEN THE INVERSION AROUND 5KFT AND HELP LIMIT THE
STRENGTH OF THE LAKE EFFECT PRECIPITATION. WHILE MUCH OF THE
FORECAST DEPENDS ON THE TIMING OF THAT SURFACE TROUGH DROPPING
ACROSS THE AREA...STILL WOULD EXPECT MANY LOCATIONS IN THE NORTHERLY
WIND SNOW BELTS TO SEE A COUPLE TO SEVERAL INCHES OF LAKE
ENHANCED/EFFECT SNOW TUESDAY AFTERNOON INTO WEDNESDAY. WILL
ALSO HIGHLIGHT THIS POTENTIAL IN THE HWO AS SOME AREAS MAY SEE
ADVISORY SNOWFALL.
BEHIND THE SURFACE TROUGH...EXPECT THE LAKE EFFECT TO DIMINISH
WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING AS THE AREA OF HIGH
PRESSURE BEGINS TO SLIDE SOUTHEAST INTO THE UPPER GREAT LAKES
REGION. WARMING TEMPERATURES ALOFT WILL ARRIVE WITH UPPER RIDGE AND
LEAD TO A QUIET END TO THE WORK WEEK AND LIKELY INTO NEXT WEEKEND.
MODELS ARE FAIRLY CONSISTENT ON THE HIGH REMAINING OVER THE UPPER
GREAT LAKES REGION THROUGH THIS PERIOD. AS FOR TEMPERATURES...EXPECT
HIGHS IN THE MID-UPPER 20S FOR THE END OF THE WORK WEEK THAT MAY TRY
TO NOSE INTO THE LOWER 30S FOR NEXT WEEKEND (WHICH WOULD BE AROUND 5
DEGREES ABOVE NORMAL FOR THAT TIME OF DECEMBER).
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY MORNING) ISSUED AT
513 AM EST SUN DEC 14 2014
IN THE PRESENCE OF DIURNAL COOLING...SLOWLY DIMINISHING SSW WINDS
AND THE ARRIVAL OF MOISTER LLVL AIR OVER MELTING SN PACK...EXPECT
CONDITIONS AT ALL 3 SITES TO FALL INTO THE LIFR RANGE MUCH OF THE
TIME THRU THIS MRNG. THE BEST CHANCE FOR SOME VLIFR CONDITIONS WL BE
AT CMX AND SAW LATER THIS MRNG WITH A MORE FAVORABLE WIND DIRECTION.
DOWNSLOPE WIND COMPONENT AT IWD WL LIMIT THE POTENTIAL FOR THIS
CONDITION AT THAT SITE. THERE WL BE ONLY A SLOW RECOVERY TO IFR
CONDITIONS WITH CONTINUED INFLUX OF MORE LLVL MSTR AND LO SUN ANGLE
HINDERING A MORE SGNFT IMPROVEMENT. NOT OUT OF THE QUESTION A
STRENGTHENING DOWNSLOPE SW FLOW IN ADVANCE OF AN APRCHG LO PRES
COULD BRING SOME MVFR WX TO IWD LATE IN THE TAF PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 511 AM EST SUN DEC 14 2014
A RIDGE ACROSS THE UPPER GREAT LAKES WILL SLOWLY SHIFT TO THE LOWER
GREAT LAKES SUNDAY INTO MONDAY. LOOK FOR AN ELONGATED AREA OF LOW
PRESSURE ACROSS THE PLAINS STATES SUNDAY MORNING TO PUSH ACROSS LAKE
SUPERIOR LATE SUNDAY NIGHT INTO MONDAY...AS THE S END OF THE TROUGH
DEEPENS ACROSS IOWA ON MONDAY. THE LOW WILL PUSH ACROSS LOWER
MICHIGAN ON TUESDAY...AND EXIT ACROSS THE LOWER GREAT LAKES TUESDAY
NIGHT. A TIGHTENING GRADIENT BEHIND THE LOW PRES SYSTEM LATE MONDAY
NIGHT INTO TUESDAY IS EXPECTED TO BRING NORTH WINDS GUSTING TO 30
KNOTS WITH A FEW GALE FORCE GUSTS TO 35 KNOTS.
WINDS WILL DIMINISH FROM WED INTO WED NIGHT AS THE LOW MOVES AWAY
AND HIGH PRESSURE HIGH PRESSURE BUILDS TOWARD THE WRN LAKES FROM THE
PLAINS. WINDS WILL THEN REMAIN AT OR BELOW 20 KNOTS THU AS THE HIGH
SETTLES OVER THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
512 AM EST SUN DEC 14 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 458 AM EST SUN DEC 14 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SPLIT FLOW PATTERN ACROSS
NORTH AMERICA WITH AN UNSEASONABLY STRONG RIDGE FROM THE MS
VALLEY INTO THE WRN GREAT LAKES DOWNSTREAM FROM A TROUGH ACROSS THE
ROCKIES. AT THE SFC..SRLY WINDS WERE INCREASING FROM THE CENTRAL
PLAINS TOWARD THE UPPER MS VALLEY AHEAD OF A TROUGH FROM CENTRAL
SOUTH DAKOTA INTO WRN NEBRASKA. THE SRLY FLOW AND LOW LEVEL MOISTURE
ADVECTION HAS PUSHED DEWPOINTS TO NEAR 40F FROM CENTRAL MN AND NW WI
TO WRN UPPER MI AND INTO THE MID 30S THROUGH CNTRL UPPER MI. A
PERSISTENT LOW STRATUS DECK HAS HELPED KEEP FOG FROM BECOMING AS
DENSE OVER UPPER MI COMPARED TO LOCATIONS OVER WI.
THERE REMAINS ONLY WEAK IF ANY FORCING FOR UPWARD MOTION OVER UPPER
MI TODAY AS THE AREA REMAINS NEAR THE MID/UPPER LEVEL RIDGE AXIS.
NEVERTHELESS...THE POTENTIAL FOR DRIZZLE SPREADING ACROSS THE AREA
REMAINS AS SOME WEAK UPWARD MOTION IS EXPECTED ABOVE THE THICKENING
LOW LEVEL MOISTURE AHEAD OF THE TROUGH SLIDING INTO THE UPPER MS
VALLEY. DRIZZLE CHANCES WILL INCREASE TOWARD EVENING AS AN AREA OF
290K ISENTROPIC ASCENT IS FORECAST TO MOVE THROUGH UPPER MI...PER
NAM/GFS. IN ADDITION...MELTING SNOW WILL ADD ADDITIONAL MOISTURE TO
SUPPORT DEVELOPMENT OF AREAS OF DENSE FOG. HOWEVER...DIURNAL WARMING
SHOULD BE JUST ENOUGH TO REDUCE THE RISK FOR MORE WIDESPREAD DENSE
FOG. TONIGHT...DENSE FOG WILL BE A BETTER POSSIBILITY WITH DIURNAL
COOING AS DEWPOINTS INTO THE UPPER 30S PREVAIL ACROSS THE AREA. THE
THE POTENTIAL FOR ACCUMULATING PCPN WILL INCREASE LATE TONIGHT OVER
THE WEST WITH DEEPER MOISTURE ARRIVING AHEAD OF THE SFC TROUGH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 257 AM EST SUN DEC 14 2014
AFTER A WARM START TO THE LONG TERM PERIOD...A RETURN TO MORE
NORMAL MID DECEMBER TEMPERATURES IS IN STORE FOR TUESDAY AND
CONTINUING THROUGH MUCH OF THE REST OF THE WORK WEEK. ON MONDAY
MORNING...THE ANOMALOUS UPPER RIDGE WILL BE LOCATED OVER THE LOWER
GREAT LAKES REGION AND QUICKLY SHIFTING EAST INTO THE NEW ENGLAND
STATES. MEANWHILE...TWO SHORTWAVES WILL BE NEARING THE AREA AND
WILL BE THE FOCUS FOR THE FIRST HALF OF THE WORK WEEK. FIRST...THE
SOUTHERN STREAM SHORTWAVE WILL BE LOCATED IN EASTERN KANSAS AT 12Z
MONDAY AND WILL BE DRIVING THE 1001MB SURFACE LOW LOCATED IN NEARLY
THE SAME LOCATION. FROM THAT SURFACE LOW...A 1006MB TROUGH WILL
EXTEND NORTHEAST THROUGH EASTERN MINNESOTA AND INTO WESTERN LAKE
SUPERIOR. AT THAT SAME TIME...A SECONDARY SHORTWAVE WILL BE DIVING
SOUTHEAST THROUGH MANITOBA. AS THE SHORTWAVE AND SURFACE LOW LIFT
NORTHEAST TOWARDS CHICAGO BY MONDAY EVENING...THE ELONGATED TROUGH
WILL SLOWLY SHIFT EAST OUT OF WESTERN LAKE SUPERIOR AND INTO THE
WESTERN U.P. AHEAD OF THE TROUGH...THE WARM/MOIST LOW LEVEL AIR
WILL CONTINUE TO PRODUCE LOW CLOUDS...DRIZZLE...AND FOG (ALTHOUGH
THERE COULD BE PERIODS OF LIGHT RAIN SHOWERS UNDER THE WEAK WARM AIR
ADVECTION AND DEEPER MOISTURE NEAR THE TROUGH AXIS). SURFACE
TEMPERATURES ON MONDAY WILL LIKELY BE FAIRLY STEADY IN THE UPPER
30S AND LOWER 40S.
HEADING INTO MONDAY NIGHT...THE SURFACE LOW AND SOUTHERN STREAM
SHORTWAVE WILL BE SLIDING INTO LOWER MICHIGAN...WHILE THE NORTHERN
STREAM SHORTWAVE BECOMES CLOSE ENOUGH TO START INTERACTING WITH
SOUTHERN SHORTWAVE. THIS WILL HELP SHIFT THE SURFACE AND LOW LEVEL
TROUGH EAST ACROSS UPPER MICHIGAN THROUGH THE NIGHT...AND BRING
COLDER LOW LEVEL AIR INTO THE AREA. OVERALL...MODELS ARE FAIRLY
CONSISTENT IN THE IDEA OF THAT COLD AIR SWITCHING THE RAIN TO SNOW
FROM NORTHWEST TO SOUTHEAST MONDAY NIGHT INTO TUESDAY MORNING.
FIRST...HAPPENING IN THE KIWD/KCMX AREA BETWEEN 02-06Z TUESDAY AND
THEN KSAW/KIMT AROUND 09Z AND AREAS OVER THE SOUTHEAST BY 18Z
TUESDAY. WITH THOSE SHORTWAVE STARTING TO INTERACT MONDAY
NIGHT...AIDING THE TIGHTENING LOW-MID LEVEL FGEN...WOULD EXPECT A
PERIOD OF MODERATE PRECIPITATION OVER WESTERN LAKE SUPERIOR AND
WESTERN UPPER MICHIGAN ON MONDAY NIGHT. SNOWFALL AMOUNTS FOR THAT
PERIOD WILL LIKELY DEPEND ON THE TIMING OF THE CHANGE OVER...BUT
WITH THE GOING TIMING WOULD EXPECT TO SEE 1-3IN FROM HERMAN TO
WATERSMEET AND WEST BY DAYBREAK TUESDAY. FARTHER EAST...THAT
DELAYED ARRIVAL OF THE COLDER AIR WILL KEEP MORE OF THE
PRECIPITATION AS RAIN BEFORE SWITCHING TO SNOW. WHEN FACTORING IN
ADDITIONAL SNOW FOR TUESDAY...MAY NEED AN ADVISORY FOR THOSE AREAS
OVER THE WEST AND WILL CONTINUE TO INCLUDE MODERATE SNOWFALL MENTION
IN THE HWO.
HEADING INTO TUESDAY...THE SURFACE LOW AND SHORTWAVE WILL SHIFT EAST
THROUGH THE LOWER GREAT LAKES AND REDUCE THE DIRECT INTERACTION OF
IT WITH THE SECONDARY SHORTWAVE NOW SLIDING SOUTH THROUGH WESTERN
LAKE SUPERIOR AND THE MINNESOTA ARROWHEAD. WHILE THIS WILL LIKELY
WEAKEN THE SYNOPTICLY FORCED PRECIPITATION...THE COLDER AIR SURGING
OVER LAKE SUPERIOR ON TUESDAY (850MB TEMPS FALLING TO AROUND -14C
OVER THE WESTERN LAKE) SHOULD LEAD TO A TRANSITION TO LAKE
ENHANCED/EFFECT SNOW OVER THE WEST INITIALLY AND THEN SHIFTING EAST
ACROSS THE REST OF THE AREA BY EVENING. CONFIDENCE DOES BEGIN TO
WAVER SOME ON TUESDAY AND CONTINUE INTO WEDNESDAY AS THE TWO
SHORTWAVE INTERACT WITH EACH OTHER OVER THE GREAT LAKES REGION.
THIS LEADS TO DIFFERENCES IN THE EXACT MODEL SOLUTIONS...BUT THE
GENERAL IDEA IS FOR THE SURFACE LOW TO CONTINUE EAST...LEAVING A
TROUGH STRETCHED WEST-NORTHWEST ACROSS LAKE SUPERIOR ON TUESDAY
AFTERNOON/EVENING UNTIL THE TRAILING SHORTWAVE CAN SLIDE IT SOUTH
WEDNESDAY. THE 00Z GFS DOES DIFFER FROM THIS IDEA AND LINGERS THE
TROUGH OVER THE UPPER GREAT LAKES UNTIL THURSDAY MORNING...WHILE THE
00Z ECMWF CAME IN A LITTLE SLOWER BUT NOT AS DELAYED AS THE GFS.
WILL FOLLOW THE GENERAL CONSENSUS AT THIS POINT AND HAVE IT MOVING
SOUTH ON TUESDAY NIGHT INTO WEDNESDAY. THEREFORE...SHOULD SEE A
PERIOD OF NORTHERLY FLOW LAKE EFFECT SPREADING ACROSS THE AREA ON
TUESDAY INTO TUESDAY NIGHT FROM WEST TO EAST AND CONTINUING INTO
WEDNESDAY. UNTIL THE COLDER AIR CAN MOVE INTO THE AREA LATER
TUESDAY AFTERNOON AND NIGHT...EXPECT THE LAKE ENHANCED PRECIPITATION
INTENSITY TO BE LIMITED TO THE WEST HALF AND WHERE IT SNOWS THE
RATIOS WILL BE ON THE LOW END (AROUND 12-1). AS THAT COLDER AIR
MOVES IN...THE CLOUD LAYER WILL NOSE INTO THE DGZ AND INCREASE THE
RATIOS...BUT THE AREA WILL ALSO START TO SEE THE AFFECT OF THE HIGH
BUILDING SOUTH INTO SOUTHERN CANADA AND THE NORTHERN PLAINS. THAT
WILL STRENGTHEN THE INVERSION AROUND 5KFT AND HELP LIMIT THE
STRENGTH OF THE LAKE EFFECT PRECIPITATION. WHILE MUCH OF THE
FORECAST DEPENDS ON THE TIMING OF THAT SURFACE TROUGH DROPPING
ACROSS THE AREA...STILL WOULD EXPECT MANY LOCATIONS IN THE NORTHERLY
WIND SNOW BELTS TO SEE A COUPLE TO SEVERAL INCHES OF LAKE
ENHANCED/EFFECT SNOW TUESDAY AFTERNOON INTO WEDNESDAY. WILL
ALSO HIGHLIGHT THIS POTENTIAL IN THE HWO AS SOME AREAS MAY SEE
ADVISORY SNOWFALL.
BEHIND THE SURFACE TROUGH...EXPECT THE LAKE EFFECT TO DIMINISH
WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING AS THE AREA OF HIGH
PRESSURE BEGINS TO SLIDE SOUTHEAST INTO THE UPPER GREAT LAKES
REGION. WARMING TEMPERATURES ALOFT WILL ARRIVE WITH UPPER RIDGE AND
LEAD TO A QUIET END TO THE WORK WEEK AND LIKELY INTO NEXT WEEKEND.
MODELS ARE FAIRLY CONSISTENT ON THE HIGH REMAINING OVER THE UPPER
GREAT LAKES REGION THROUGH THIS PERIOD. AS FOR TEMPERATURES...EXPECT
HIGHS IN THE MID-UPPER 20S FOR THE END OF THE WORK WEEK THAT MAY TRY
TO NOSE INTO THE LOWER 30S FOR NEXT WEEKEND (WHICH WOULD BE AROUND 5
DEGREES ABOVE NORMAL FOR THAT TIME OF DECEMBER).
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 842 PM EST SAT DEC 13 2014
IN THE PRESENCE OF DIURNAL COOLING...SLOWLY DIMINISHING SW WINDS AND
THE ARRIVAL OF MOISTER LLVL AIR OVER MELTING SN PACK...EXPECT
CONDITIONS AT CMX AND SAW TO DETERIORATE TO LIFR AND THEN VLIFR
OVERNGT. DOWNSLOPE WIND COMPONENT AT IWD WL LIKELY WL LIKELY LIMIT
THE WORST CONDITIONS TO LIFR THERE. THERE WL BE ONLY A SLOW RECOVERY
TO IFR CONDITIONS ON SUN AFTN WITH CONTINUED INFLUX OF MORE LLVL
MSTR AND LO SUN ANGLE HINDERING A MORE SGNFT IMPROVEMENT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 511 AM EST SUN DEC 14 2014
A RIDGE ACROSS THE UPPER GREAT LAKES WILL SLOWLY SHIFT TO THE LOWER
GREAT LAKES SUNDAY INTO MONDAY. LOOK FOR AN ELONGATED AREA OF LOW
PRESSURE ACROSS THE PLAINS STATES SUNDAY MORNING TO PUSH ACROSS LAKE
SUPERIOR LATE SUNDAY NIGHT INTO MONDAY...AS THE S END OF THE TROUGH
DEEPENS ACROSS IOWA ON MONDAY. THE LOW WILL PUSH ACROSS LOWER
MICHIGAN ON TUESDAY...AND EXIT ACROSS THE LOWER GREAT LAKES TUESDAY
NIGHT. A TIGHTENING GRADIENT BEHIND THE LOW PRES SYSTEM LATE MONDAY
NIGHT INTO TUESDAY IS EXPECTED TO BRING NORTH WINDS GUSTING TO 30
KNOTS WITH A FEW GALE FORCE GUSTS TO 35 KNOTS.
WINDS WILL DIMINISH FROM WED INTO WED NIGHT AS THE LOW MOVES AWAY
AND HIGH PRESSURE HIGH PRESSURE BUILDS TOWARD THE WRN LAKES FROM THE
PLAINS. WINDS WILL THEN REMAIN AT OR BELOW 20 KNOTS THU AS THE HIGH
SETTLES OVER THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
501 AM EST SUN DEC 14 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 458 AM EST SUN DEC 14 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SPLIT FLOW PATTERN ACROSS
NORTH AMERICA WITH AN UNSESONABLY STRONG RIDGE FROM THE MS
VALLEY INTHE WRN GREAT LAKES DOWNSTREAM FROM A TROUIGH ACROSS THE
ROCKIES. AT THE SFC..SRLY WINDS WERE INCREASING FROM THE CENTRAL
PLAINS TOWARD THE UPPER MS VALLEY AHEAD OF A TROUGH FROM CENTRAL
SOUTH DAKOTA INTO WRN NEBRASKA. THE SRLY FLOW AND LOW LEVEL MOISTURE
ADVECTION HAS PUSHED DEWPOINTS TO NEAR 40F FROM CENTRAL MN AND NW WI
TO WRN UPPER MI AND INTO THE MID 30S THROUGH CNTRL UPPER MI. A
PERSISTENT LOW STRATUS DECK HAS HELPED KEEP FOG FROM BECOMING AS
DENSE OVER UPPER MI COMPARED TO LOCATIONS OVER WI.
THERE REMAINS ONLY WEAK IF ANY FORCING FOR UPWARD MOTION OVER UPPER
MI TODAY AS THE AREA REMAINS NEAR THE MID/UPPER LEVEL RIDGE AXIS.
NEVERTHELESS...THE POTENTIAL FOR DRIZZLE SPREADING ACROSS THE AREA
REMAINS AS SOME WEAK UPWARD MOTION IS EXPECTED ABOVE THE THICKENING
LOW LEVEL MOISTURE AHEAD OF THE TROUGH SLIDING INTO THE UPPER MS
VALLEY. DRIZZLE CHANCES WILL INCREASE TOWARD EVENING AS AN AREA OF
290K ISENTROPIC ASCENT IS FORECAST TO MOVE THROUGH UPPER MI...PER
NAM/GFS. IN ADDITION...MELTING SNOW WILL ADD ADDITIONAL MOISTURE TO
SUPPORT DEVELOPMENT OF AREAS OF DENSE FOG. HOWEVER...DIURNAL WARMING
SHOULD BE JUST ENOUGH TO REDUCE THE RISK FOR MORE WIDESPREAD DENSE
FOG. TONIGHT...DENSE FOG WILL BE A BETTER POSSIBILITY WITH DIURNAL
COOING AS DEWPOINTS INTO THE UPPER 30S PREVAIL ACROSS THE AREA. THE
THE POTENTIAL FOR ACCUMULATING PCPN WILL INCREASE LATE TONIGHT OVER
THE WEST WITH DEEPER MOISTURE ARRIVING AHEAD OF THE SFC TROUGH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 257 AM EST SUN DEC 14 2014
AFTER A WARM START TO THE LONG TERM PERIOD...A RETURN TO MORE
NORMAL MID DECEMBER TEMPERATURES IS IN STORE FOR TUESDAY AND
CONTINUING THROUGH MUCH OF THE REST OF THE WORK WEEK. ON MONDAY
MORNING...THE ANOMALOUS UPPER RIDGE WILL BE LOCATED OVER THE LOWER
GREAT LAKES REGION AND QUICKLY SHIFTING EAST INTO THE NEW ENGLAND
STATES. MEANWHILE...TWO SHORTWAVES WILL BE NEARING THE AREA AND
WILL BE THE FOCUS FOR THE FIRST HALF OF THE WORK WEEK. FIRST...THE
SOUTHERN STREAM SHORTWAVE WILL BE LOCATED IN EASTERN KANSAS AT 12Z
MONDAY AND WILL BE DRIVING THE 1001MB SURFACE LOW LOCATED IN NEARLY
THE SAME LOCATION. FROM THAT SURFACE LOW...A 1006MB TROUGH WILL
EXTEND NORTHEAST THROUGH EASTERN MINNESOTA AND INTO WESTERN LAKE
SUPERIOR. AT THAT SAME TIME...A SECONDARY SHORTWAVE WILL BE DIVING
SOUTHEAST THROUGH MANITOBA. AS THE SHORTWAVE AND SURFACE LOW LIFT
NORTHEAST TOWARDS CHICAGO BY MONDAY EVENING...THE ELONGATED TROUGH
WILL SLOWLY SHIFT EAST OUT OF WESTERN LAKE SUPERIOR AND INTO THE
WESTERN U.P. AHEAD OF THE TROUGH...THE WARM/MOIST LOW LEVEL AIR
WILL CONTINUE TO PRODUCE LOW CLOUDS...DRIZZLE...AND FOG (ALTHOUGH
THERE COULD BE PERIODS OF LIGHT RAIN SHOWERS UNDER THE WEAK WARM AIR
ADVECTION AND DEEPER MOISTURE NEAR THE TROUGH AXIS). SURFACE
TEMPERATURES ON MONDAY WILL LIKELY BE FAIRLY STEADY IN THE UPPER
30S AND LOWER 40S.
HEADING INTO MONDAY NIGHT...THE SURFACE LOW AND SOUTHERN STREAM
SHORTWAVE WILL BE SLIDING INTO LOWER MICHIGAN...WHILE THE NORTHERN
STREAM SHORTWAVE BECOMES CLOSE ENOUGH TO START INTERACTING WITH
SOUTHERN SHORTWAVE. THIS WILL HELP SHIFT THE SURFACE AND LOW LEVEL
TROUGH EAST ACROSS UPPER MICHIGAN THROUGH THE NIGHT...AND BRING
COLDER LOW LEVEL AIR INTO THE AREA. OVERALL...MODELS ARE FAIRLY
CONSISTENT IN THE IDEA OF THAT COLD AIR SWITCHING THE RAIN TO SNOW
FROM NORTHWEST TO SOUTHEAST MONDAY NIGHT INTO TUESDAY MORNING.
FIRST...HAPPENING IN THE KIWD/KCMX AREA BETWEEN 02-06Z TUESDAY AND
THEN KSAW/KIMT AROUND 09Z AND AREAS OVER THE SOUTHEAST BY 18Z
TUESDAY. WITH THOSE SHORTWAVE STARTING TO INTERACT MONDAY
NIGHT...AIDING THE TIGHTENING LOW-MID LEVEL FGEN...WOULD EXPECT A
PERIOD OF MODERATE PRECIPITATION OVER WESTERN LAKE SUPERIOR AND
WESTERN UPPER MICHIGAN ON MONDAY NIGHT. SNOWFALL AMOUNTS FOR THAT
PERIOD WILL LIKELY DEPEND ON THE TIMING OF THE CHANGE OVER...BUT
WITH THE GOING TIMING WOULD EXPECT TO SEE 1-3IN FROM HERMAN TO
WATERSMEET AND WEST BY DAYBREAK TUESDAY. FARTHER EAST...THAT
DELAYED ARRIVAL OF THE COLDER AIR WILL KEEP MORE OF THE
PRECIPITATION AS RAIN BEFORE SWITCHING TO SNOW. WHEN FACTORING IN
ADDITIONAL SNOW FOR TUESDAY...MAY NEED AN ADVISORY FOR THOSE AREAS
OVER THE WEST AND WILL CONTINUE TO INCLUDE MODERATE SNOWFALL MENTION
IN THE HWO.
HEADING INTO TUESDAY...THE SURFACE LOW AND SHORTWAVE WILL SHIFT EAST
THROUGH THE LOWER GREAT LAKES AND REDUCE THE DIRECT INTERACTION OF
IT WITH THE SECONDARY SHORTWAVE NOW SLIDING SOUTH THROUGH WESTERN
LAKE SUPERIOR AND THE MINNESOTA ARROWHEAD. WHILE THIS WILL LIKELY
WEAKEN THE SYNOPTICLY FORCED PRECIPITATION...THE COLDER AIR SURGING
OVER LAKE SUPERIOR ON TUESDAY (850MB TEMPS FALLING TO AROUND -14C
OVER THE WESTERN LAKE) SHOULD LEAD TO A TRANSITION TO LAKE
ENHANCED/EFFECT SNOW OVER THE WEST INITIALLY AND THEN SHIFTING EAST
ACROSS THE REST OF THE AREA BY EVENING. CONFIDENCE DOES BEGIN TO
WAVER SOME ON TUESDAY AND CONTINUE INTO WEDNESDAY AS THE TWO
SHORTWAVE INTERACT WITH EACH OTHER OVER THE GREAT LAKES REGION.
THIS LEADS TO DIFFERENCES IN THE EXACT MODEL SOLUTIONS...BUT THE
GENERAL IDEA IS FOR THE SURFACE LOW TO CONTINUE EAST...LEAVING A
TROUGH STRETCHED WEST-NORTHWEST ACROSS LAKE SUPERIOR ON TUESDAY
AFTERNOON/EVENING UNTIL THE TRAILING SHORTWAVE CAN SLIDE IT SOUTH
WEDNESDAY. THE 00Z GFS DOES DIFFER FROM THIS IDEA AND LINGERS THE
TROUGH OVER THE UPPER GREAT LAKES UNTIL THURSDAY MORNING...WHILE THE
00Z ECMWF CAME IN A LITTLE SLOWER BUT NOT AS DELAYED AS THE GFS.
WILL FOLLOW THE GENERAL CONSENSUS AT THIS POINT AND HAVE IT MOVING
SOUTH ON TUESDAY NIGHT INTO WEDNESDAY. THEREFORE...SHOULD SEE A
PERIOD OF NORTHERLY FLOW LAKE EFFECT SPREADING ACROSS THE AREA ON
TUESDAY INTO TUESDAY NIGHT FROM WEST TO EAST AND CONTINUING INTO
WEDNESDAY. UNTIL THE COLDER AIR CAN MOVE INTO THE AREA LATER
TUESDAY AFTERNOON AND NIGHT...EXPECT THE LAKE ENHANCED PRECIPITATION
INTENSITY TO BE LIMITED TO THE WEST HALF AND WHERE IT SNOWS THE
RATIOS WILL BE ON THE LOW END (AROUND 12-1). AS THAT COLDER AIR
MOVES IN...THE CLOUD LAYER WILL NOSE INTO THE DGZ AND INCREASE THE
RATIOS...BUT THE AREA WILL ALSO START TO SEE THE AFFECT OF THE HIGH
BUILDING SOUTH INTO SOUTHERN CANADA AND THE NORTHERN PLAINS. THAT
WILL STRENGTHEN THE INVERSION AROUND 5KFT AND HELP LIMIT THE
STRENGTH OF THE LAKE EFFECT PRECIPITATION. WHILE MUCH OF THE
FORECAST DEPENDS ON THE TIMING OF THAT SURFACE TROUGH DROPPING
ACROSS THE AREA...STILL WOULD EXPECT MANY LOCATIONS IN THE NORTHERLY
WIND SNOW BELTS TO SEE A COUPLE TO SEVERAL INCHES OF LAKE
ENHANCED/EFFECT SNOW TUESDAY AFTERNOON INTO WEDNESDAY. WILL
ALSO HIGHLIGHT THIS POTENTIAL IN THE HWO AS SOME AREAS MAY SEE
ADVISORY SNOWFALL.
BEHIND THE SURFACE TROUGH...EXPECT THE LAKE EFFECT TO DIMINISH
WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING AS THE AREA OF HIGH
PRESSURE BEGINS TO SLIDE SOUTHEAST INTO THE UPPER GREAT LAKES
REGION. WARMING TEMPERATURES ALOFT WILL ARRIVE WITH UPPER RIDGE AND
LEAD TO A QUIET END TO THE WORK WEEK AND LIKELY INTO NEXT WEEKEND.
MODELS ARE FAIRLY CONSISTENT ON THE HIGH REMAINING OVER THE UPPER
GREAT LAKES REGION THROUGH THIS PERIOD. AS FOR TEMPERATURES...EXPECT
HIGHS IN THE MID-UPPER 20S FOR THE END OF THE WORK WEEK THAT MAY TRY
TO NOSE INTO THE LOWER 30S FOR NEXT WEEKEND (WHICH WOULD BE AROUND 5
DEGREES ABOVE NORMAL FOR THAT TIME OF DECEMBER).
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 842 PM EST SAT DEC 13 2014
IN THE PRESENCE OF DIURNAL COOLING...SLOWLY DIMINISHING SW WINDS AND
THE ARRIVAL OF MOISTER LLVL AIR OVER MELTING SN PACK...EXPECT
CONDITIONS AT CMX AND SAW TO DETERIORATE TO LIFR AND THEN VLIFR
OVERNGT. DOWNSLOPE WIND COMPONENT AT IWD WL LIKELY WL LIKELY LIMIT
THE WORST CONDITIONS TO LIFR THERE. THERE WL BE ONLY A SLOW RECOVERY
TO IFR CONDITIONS ON SUN AFTN WITH CONTINUED INFLUX OF MORE LLVL
MSTR AND LO SUN ANGLE HINDERING A MORE SGNFT IMPROVEMENT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 341 PM EST SAT DEC 13 2014
WARMER AIR WILL KEEP THE MENTION OF FREEZING SPRAY OUT OF THE FCST
FOR THE TIME BEING. THE CONCERN IN THE NEAR TERM WILL BE OFF AND ON
FOG TONIGHT THROUGH TUESDAY OVER MAINLY S PORTIONS OF LAKE
SUPERIOR.
A RIDGE ACROSS THE UPPER GREAT LAKES WILL SLOWLY SHIFT TO
THE LOWER GREAT LAKES SUNDAY INTO MONDAY. LOOK FOR AN ELONGATED AREA
OF LOW PRESSURE ACROSS THE PLAINS STATES SUNDAY MORNING TO PUSH
ACROSS LAKE SUPERIOR LATE SUNDAY NIGHT INTO MONDAY...AS THE S END OF
THE TROUGH DEEPENS ACROSS IOWA ON MONDAY. THE LOW WILL PUSH ACROSS
LOWER MICHIGAN ON TUESDAY...AND EXIT ACROSS THE LOWER GREAT LAKES
TUESDAY NIGHT. MONDAY NIGHT INTO TUESDAY NIGHT COULD BRING N WIND
GUSTING TO NEAR 30KTS OVER N AND E LAKE SUPERIOR.
HIGH PRESSURE STRETCHING FROM S CENTRAL CANADA THROUGH THE CENTRAL
PLAINS TUESDAY NIGHT WILL CROSS THE UPPER GREAT LAKES WEDNESDAY
NIGHT THROUGH THURSDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
903 PM CST MON DEC 15 2014
.SYNOPSIS...
ISSUED AT 315 PM CST MON DEC 15 2014
H5 ANALYSIS FROM EARLIER THIS MORNING HAD AN UPPER LEVEL
LOW OVER CENTRAL KS IN THE VICINITY OF SALINA WITH A TROUGH
EXTENDING SWD INTO THE ARKLATEX. DOWNSTREAM RIDGING WAS PRESENT
ACROSS THE EASTERN GREAT LAKES AND MID ATLANTIC STATES. NORTHWEST OF
THE CLOSED LOW...HIGH PRESSURE WAS PRESENT OVER NWRN ALBERTA...WHILE
A TROUGH OF LOW PRESSURE EXTENDED FROM THE GULF OF ALASKA SOUTH TO
JUST OFF THE COAST OF NRN CALIFORNIA. AS OF 2 PM CST...THE UPPER
LEVEL LOW HAD TRACKED FROM CENTRAL KS TO JUST NORTH OF CHILLICOTHE
MO. AT THE SURFACE...LOW PRESSURE WAS IN THE VICINITY OF LAMONI IOWA
WITH A COLD FRONT EXTENDING SSE INTO SOUTH CENTRAL MO. HIGH PRESSURE
WAS NOTED OVER EASTERN MT. ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA...STRONG NORTHERLY WINDS WERE PRESENT...ALONG WITH LIGHT
SNOW...WHICH AS REDUCED VISIBILITIES DOWN TO 1/2SM TO 2SM AS OF 2 PM
CST. UNDER CLOUDY SKIES...TEMPERATURES AS OF 2 PM CST RANGED
FROM...25 AT VALENTINE...TO 29 AT NORTH PLATTE...BROKEN BOW AND
OGALLALA.
&&
.UPDATE...
ISSUED AT 903 PM CST MON DEC 15 2014
RADAR IS QUIET BUT THERE IS LIGHT SNOW AT KONL WITH VISIBILITY
2 TO 3 MILES AND WIND SPEEDS NEVER CAME UP IN THIS AREA SO IT IS
NOT BLOWING SNOW. GIVEN THE RADAR TRENDS AT KLNX AND KFSD...THIS
SNOW SHOULD BE ENDING BY 11 PM SO THE WINTER WEATHER HIGHLIGHTS
HAVE BEEN ALLOWED TO EXPIRE AT 9 PM CST.
UPDATE ISSUED AT 612 PM CST MON DEC 15 2014
SOME WEATHER HIGHLIGHTS HAVE BEEN ALLOWED EXPIRE AT 6 PM. JUST
FLURRIES ARE INDICATED ALONG HIGHWAY 61 AND INTERSTATE 80. CLOUD
CEILINGS ARE RISING IN THIS AREA SUPPORTING LIGHTER WINDS.
THE HRRR...RAP AND NAM SHOW FOG ACROSS WRN NEB BY MORNING AS THE
MONTANA SFC HIGH PRESSURE SYSTEM BUILDS ACROSS THIS AREA BY 12Z
TUESDAY. ALSO...LOWERED OVERNIGHT TEMPERATURES IN THIS AREA.
THESE MODELS SHOW WINDS OF 5 KT OR LESS WITH CLEARING SKIES AND
RADIATIVE COOLING TAKING HOLD. SOME DRY AIR WILL BE MOVING IN
ALOFT SUPPORTING LOWS NEAR ZERO BUT NOT SO DRY AS TO SUPPORT
WIDESPREAD SUBZERO LOWS. FOG WILL LIKELY FORM BEFORE THIS HAPPENS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 315 PM CST MON DEC 15 2014
FOR THE NEXT 36 HOURS...MAIN FORECAST CONCERNS REVOLVE
AROUND THE EXIT OF THE UPPER LEVEL SYSTEM THAT IS BRINGING
WIDESPREAD ACCUMULATING SNOW TO THE REGION. TEMPERATURE FORECAST
TONIGHT AND TOMORROW ALSO DESERVES CONSIDERATION.
FORECAST GUIDANCE INDICATES THE UPPER LOW WILL CONTINUE TO THE EAST
OVER THE UPPER MISSISSIPPI VALLEY...AND GET CAUGHT UP IN A NORTHERN
STREAM SHORTWAVE/UPPER LOW OVER THE NEXT 24 HOURS. LOW AMPLITUDE
TRANSITORY RIDGING WILL THEN TAKE HOLD ACROSS THE CENTRAL PLAINS AS
THE NEXT UPPER LEVEL TROUGH DEEPENS OVER THE WESTERN COAST. AT THE
SURFACE...CANADIAN HIGH PRESSURE WILL FILL SOUTH BEHIND THE
DEPARTING SURFACE LOW PROVIDING FOR DRIER CONDITIONS AND COOLER
TEMPERATURES. WITH CAA FILTERING SOUTH ACROSS THE
PLAINS...OVERNIGHT LOWS WILL BE CHILLY...GENERALLY IN THE SINGLE
DIGITS AND LOWER TEENS FROM WEST TO EAST ACROSS THE FORECAST AREA.
THE OVERNIGHT TEMPERATURE FORECAST IS A PRODUCT OF NUMERICAL
GUIDANCE WITH THE PREVIOUS FORECAST...WHICH ASSUMES SOME CLEARING.
IF SUBSTANTIAL CLEARING WERE TO OCCUR...TEMPERATURES MAY PLUMMET
ACROSS OUR WESTERN ZONES AS A FRESH SNOWPACK COMBINES WITH LIGHT
WINDS. HIGHS REBOUND SOME TUESDAY...BUT WITH CANADIAN HIGH PRESSURE
OVERHEAD...AND WEAK COLD AIR ADVECTION CONTINUING...HIGHS SHOULD
ONLY TOP OUT IN THE 20S FOR LOCATIONS ALONG AND NORTH OF
I80...POSSIBLY A FEW LOWER 30S COULD BE ACHIEVED ACROSS OUR SOUTH AS
THE WINDS BEGIN TO VEER TO THE SOUTH LATE IN THE DAY BEHIND THE HIGH.
CONCERNING PRECIPITATION...NEAR TERM GUIDANCE HAS ACCUMULATING
SNOWFALL OUT OF THE CWA...SAVE FOR THE NORTHEASTERN SANDHILLS AND
NORTH CENTRAL NEBRASKA BY 00Z THIS EVENING...WITH SNOW ENDING
GENERALLY AT 03Z FOR OUR FAR NORTHEAST. THE FORECAST USED A BLEND
OF THE 15.12Z NAM12 WITH THE LATEST RAP WHICH SEEMS TO PROVIDE A
PLAUSIBLE NORTHWEST TO EAST DEMISE OF THE SNOWFALL. IR
SATELLITE/RADAR TRENDS OVER THE PAST FEW HOURS EARLY AFTERNOON
SUPPORT THE IDEA AS CLOUD TOPS ARE WARMING AND REFLECTIVITY IS
BECOMING LESS DEFINED. SUPPOSE ANOTHER INCH OR TWO OF SNOW IS STILL
POSSIBLE ACROSS OUR NORTHERN ZONES LATE THIS AFTERNOON AS THE MODELS
SUGGEST QPF RATES OF UP TO FIVE HUNDREDTHS OF AN INCH PER HOUR
CONTINUING UNTIL 03Z. IMPACTS FROM ANY ADDITIONAL SNOW HOWEVER WILL
CONTINUE TO COMPOUND VISIBILITY ISSUES WITH BLOWING SNOW FROM THE
30-40 MPH GUSTS OCCURRING...WINDS WILL WEAKEN THOUGH AS THE PRESSURE
GRADIENT RELAXES THIS EVENING.
THE CURRENT WINTER STORM WARNING AND WINTER WEATHER ADVISORY WILL
EXPIRE AT 00Z THIS EVENING...BUT A FEW SMALL CHANGES MAYBE/ARE
NEEDED. ACROSS NORTH CENTRAL NEBRASKA...A EXTENSION OF THE
ADVISORY/WARNING IS NEEDED THROUGH 03Z TO ACCOUNT FOR THE LATER
ENDING TIME OF SNOW AND GUSTY NORTHWEST WIND. COUNTIES MAY BE
DROPPED ACROSS OUR FAR SOUTH EARLY..BUT THE RECENT OB FROM KMCK
SUGGEST LIGHT TO OCCASIONAL MODERATE SNOW...WILL RE-EVALUATE IN THE
NEXT COUPLE HORUS. ELSEWHERE THE HEADLINES ARE ANTICIPATED TO BE
ALLOWED TO EXPIRE ON TIME.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 315 PM CST MON DEC 15 2014
MID RANGE...TUESDAY NIGHT THROUGH THURSDAY...IN THE MID
RANGE PERIODS...TEMPERATURES AND PRECIPITATION CHANCES ON WEDNESDAY
NIGHT ARE THE MAIN FORECASTING CHALLENGES IN THE MID RANGE PERIODS.
FOR TUESDAY NIGHT...A TROUGH OF LOW PRESSURE ALOFT WILL PUSH INTO
SRN CALIFORNIA RESULTING IN ANOTHER SOAKER FOR THE SWRN CONUS.
DOWNSTREAM OF THE TROUGH...LOW AMPLITUDE RIDGING WILL EXTEND ACROSS
THE SRN PLAINS INTO NEBRASKA. SURFACE HIGH PRESSURE WILL DOMINATE
THE PLAINS STATES AND OZARKS TUESDAY NIGHT. WITH FRESH
SNOWCOVER...LIGHT WINDS AND PARTLY CLOUDY SKIES...LOWS WILL BE COLD
IN THE SINGLE DIGITS AND LOWS WERE TRENDED DOWNWARD FROM THE
INHERITED FORECAST. FOR WEDNESDAY AND WEDNESDAY NIGHT...THE UPPER
LEVEL TROUGH WILL MIGRATE EAST INTO THE DESERT SOUTHWEST. SOME MODEL
DIFFERENCES WERE NOTED WITH THE FORWARD SPEED AND TRACK OF THIS
SYSTEM MIDWEEK. THE LATEST NAM AND ECMWF SOLNS FROM 12Z THIS MORNING
ACTUALLY DEVELOP A CLOSED LOW ALONG THE AZ/NM AND MEXICAN BORDER AT
00Z FRIDAY. THE GFS IS FASTER AND OPEN WITH THIS SYSTEM...MIGRATING
IT INTO NM AND WEST TX BY 00Z FRIDAY. WHAT ALL THREE MODELS DO
INDICATE IS A LEAD DISTURBANCE WHICH CROSSES THE SRN PLAINS INTO THE
OZARKS WEDNESDAY NIGHT. BOTH THE GFS AND ECMWF SOLNS LIFT INCREASED
LOW LEVEL MOISTURE INTO SRN NEBRASKA WEDNESDAY NIGHT IN ASSOCIATION
WITH THE LEAD DISTURBANCE. LIFT HOWEVER REMAINS WEAK PER CROSS
SECTIONS...AND WITH A FAIRLY DRY LAYER AROUND H7...AM NOT TOO
EXCITED ABOUT PCPN IN OUR AREA WEDS NIGHT. INHERITED FCST HAD A
SLIGHT CHANCE MENTION IN THE SOUTH AND SERN CWA DURING THE PERIOD
AND GIVEN THE LOW LEVEL MOISTURE AND SOME MODEL AGREEMENT BETWEEN
THE GFS AND ECMWF SOLNS...WILL LEAVE POP MENTION UNCHANGED FOR NOW.
AS FOR PTYPE WEDNESDAY NIGHT...LOOKING AT FCST SOUNDINGS...WAS
INITIALLY A LITTLE CONCERNED ABOUT THE THREAT FOR FREEZING DRIZZLE
IN THE SERN CWA. LOOKING AT BUFKIT SOUNDINGS...THE THREAT FOR FZDZ
SHOULD BE OFF TO THE SOUTHEAST OF THE FORECAST AREA AND WILL LEAVE
PRECIP MENTION AS ALL SNOW.
THURSDAY NIGHT THROUGH MONDAY...A TANDEM OF SRN STREAM WAVES WILL
TRACK ACROSS THE SRN TIER OF STATES FRIDAY...AND THEN AGAIN SUNDAY
NIGHT INTO MONDAY. ATTM...FAVORABLE FORCING FOR PRECIPITATION SHOULD
REMAIN SOUTH OF THE FORECAST AREA SO WILL FORECAST DRY CONDS ATTM.
HOWEVER...THE LATEST GFS SOLN BEGINS TO DIVERGE TOWARD A MORE ACTIVE
NRN STREAM NEXT WEEK...FORCING A CLIPPER SYSTEM THROUGH THE NRN
PLAINS EARLY NEXT WEEK...FOLLOWED BY SECOND...MUCH STRONGER NRN
STREAM SYSTEM AROUND CHRISTMAS EVE. IF THIS WOULD VERIFY...WE COULD
SEE COLD TEMPERATURES AND A POSSIBLE THREAT FOR SNOW. IN THE
MEANTIME...DECIDED TO KEEP CONDS DRY THROUGH THE WEEKEND AND INTO
NEXT WEEK...GIVEN THE ACTIVE SRN STREAM...WITH PCPN EXPECTED WELL
SOUTH OF THE FCST AREA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 528 PM CST MON DEC 15 2014
THE SNOW AND BLOWING SNOW ACROSS NCNTL NEB SHOULD EXIT THE FCST
AREA 03Z-06Z THIS EVENING. FROM 06Z-15Z...FOG IS EXPECTED TO
DEVELOP...MAINLY ALONG AND WEST OF HIGHWAY 61 WITH POTENTIAL FOR
LIFR. MVFR CIGS ARE EXPECTED DURING THE SAME TIME ALONG AND EAST
OF HIGHWAY 183. VFR IS EXPECTED ALL AREAS FROM 15Z TUESDAY ONWARD.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CDC
SYNOPSIS...CLB
SHORT TERM...JACOBS
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
612 PM CST MON DEC 15 2014
.SYNOPSIS...
ISSUED AT 315 PM CST MON DEC 15 2014
H5 ANALYSIS FROM EARLIER THIS MORNING HAD AN UPPER LEVEL
LOW OVER CENTRAL KS IN THE VICINITY OF SALINA WITH A TROUGH
EXTENDING SWD INTO THE ARKLATEX. DOWNSTREAM RIDGING WAS PRESENT
ACROSS THE EASTERN GREAT LAKES AND MID ATLANTIC STATES. NORTHWEST OF
THE CLOSED LOW...HIGH PRESSURE WAS PRESENT OVER NWRN ALBERTA...WHILE
A TROUGH OF LOW PRESSURE EXTENDED FROM THE GULF OF ALASKA SOUTH TO
JUST OFF THE COAST OF NRN CALIFORNIA. AS OF 2 PM CST...THE UPPER
LEVEL LOW HAD TRACKED FROM CENTRAL KS TO JUST NORTH OF CHILLICOTHE
MO. AT THE SURFACE...LOW PRESSURE WAS IN THE VICINITY OF LAMONI IOWA
WITH A COLD FRONT EXTENDING SSE INTO SOUTH CENTRAL MO. HIGH PRESSURE
WAS NOTED OVER EASTERN MT. ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA...STRONG NORTHERLY WINDS WERE PRESENT...ALONG WITH LIGHT
SNOW...WHICH AS REDUCED VISIBILITIES DOWN TO 1/2SM TO 2SM AS OF 2 PM
CST. UNDER CLOUDY SKIES...TEMPERATURES AS OF 2 PM CST RANGED
FROM...25 AT VALENTINE...TO 29 AT NORTH PLATTE...BROKEN BOW AND
OGALLALA.
&&
.UPDATE...
ISSUED AT 612 PM CST MON DEC 15 2014
SOME WEATHER HIGHLIGHTS HAVE BEEN ALLOWED EXPIRE AT 6 PM. JUST
FLURRIES ARE INDICATED ALONG HIGHWAY 61 AND INTERSTATE 80. CLOUD
CEILINGS ARE RISING IN THIS AREA SUPPORTING LIGHTER WINDS.
THE HRRR...RAP AND NAM SHOW FOG ACROSS WRN NEB BY MORNING AS THE
MONTANA SFC HIGH PRESSURE SYSTEM BUILDS ACROSS THIS AREA BY 12Z
TUESDAY. ALSO...LOWERED OVERNIGHT TEMPERATURES IN THIS AREA.
THESE MODELS SHOW WINDS OF 5 KT OR LESS WITH CLEARING SKIES AND
RADIATIVE COOLING TAKING HOLD. SOME DRY AIR WILL BE MOVING IN
ALOFT SUPPORTING LOWS NEAR ZERO BUT NOT SO DRY AS TO SUPPORT
WIDESPREAD SUBZERO LOWS. FOG WILL LIKELY FORM BEFORE THIS HAPPENS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 315 PM CST MON DEC 15 2014
FOR THE NEXT 36 HOURS...MAIN FORECAST CONCERNS REVOLVE
AROUND THE EXIT OF THE UPPER LEVEL SYSTEM THAT IS BRINGING
WIDESPREAD ACCUMULATING SNOW TO THE REGION. TEMPERATURE FORECAST
TONIGHT AND TOMORROW ALSO DESERVES CONSIDERATION.
FORECAST GUIDANCE INDICATES THE UPPER LOW WILL CONTINUE TO THE EAST
OVER THE UPPER MISSISSIPPI VALLEY...AND GET CAUGHT UP IN A NORTHERN
STREAM SHORTWAVE/UPPER LOW OVER THE NEXT 24 HOURS. LOW AMPLITUDE
TRANSITORY RIDGING WILL THEN TAKE HOLD ACROSS THE CENTRAL PLAINS AS
THE NEXT UPPER LEVEL TROUGH DEEPENS OVER THE WESTERN COAST. AT THE
SURFACE...CANADIAN HIGH PRESSURE WILL FILL SOUTH BEHIND THE
DEPARTING SURFACE LOW PROVIDING FOR DRIER CONDITIONS AND COOLER
TEMPERATURES. WITH CAA FILTERING SOUTH ACROSS THE
PLAINS...OVERNIGHT LOWS WILL BE CHILLY...GENERALLY IN THE SINGLE
DIGITS AND LOWER TEENS FROM WEST TO EAST ACROSS THE FORECAST AREA.
THE OVERNIGHT TEMPERATURE FORECAST IS A PRODUCT OF NUMERICAL
GUIDANCE WITH THE PREVIOUS FORECAST...WHICH ASSUMES SOME CLEARING.
IF SUBSTANTIAL CLEARING WERE TO OCCUR...TEMPERATURES MAY PLUMMET
ACROSS OUR WESTERN ZONES AS A FRESH SNOWPACK COMBINES WITH LIGHT
WINDS. HIGHS REBOUND SOME TUESDAY...BUT WITH CANADIAN HIGH PRESSURE
OVERHEAD...AND WEAK COLD AIR ADVECTION CONTINUING...HIGHS SHOULD
ONLY TOP OUT IN THE 20S FOR LOCATIONS ALONG AND NORTH OF
I80...POSSIBLY A FEW LOWER 30S COULD BE ACHIEVED ACROSS OUR SOUTH AS
THE WINDS BEGIN TO VEER TO THE SOUTH LATE IN THE DAY BEHIND THE HIGH.
CONCERNING PRECIPITATION...NEAR TERM GUIDANCE HAS ACCUMULATING
SNOWFALL OUT OF THE CWA...SAVE FOR THE NORTHEASTERN SANDHILLS AND
NORTH CENTRAL NEBRASKA BY 00Z THIS EVENING...WITH SNOW ENDING
GENERALLY AT 03Z FOR OUR FAR NORTHEAST. THE FORECAST USED A BLEND
OF THE 15.12Z NAM12 WITH THE LATEST RAP WHICH SEEMS TO PROVIDE A
PLAUSIBLE NORTHWEST TO EAST DEMISE OF THE SNOWFALL. IR
SATELLITE/RADAR TRENDS OVER THE PAST FEW HOURS EARLY AFTERNOON
SUPPORT THE IDEA AS CLOUD TOPS ARE WARMING AND REFLECTIVITY IS
BECOMING LESS DEFINED. SUPPOSE ANOTHER INCH OR TWO OF SNOW IS STILL
POSSIBLE ACROSS OUR NORTHERN ZONES LATE THIS AFTERNOON AS THE MODELS
SUGGEST QPF RATES OF UP TO FIVE HUNDREDTHS OF AN INCH PER HOUR
CONTINUING UNTIL 03Z. IMPACTS FROM ANY ADDITIONAL SNOW HOWEVER WILL
CONTINUE TO COMPOUND VISIBILITY ISSUES WITH BLOWING SNOW FROM THE
30-40 MPH GUSTS OCCURRING...WINDS WILL WEAKEN THOUGH AS THE PRESSURE
GRADIENT RELAXES THIS EVENING.
THE CURRENT WINTER STORM WARNING AND WINTER WEATHER ADVISORY WILL
EXPIRE AT 00Z THIS EVENING...BUT A FEW SMALL CHANGES MAYBE/ARE
NEEDED. ACROSS NORTH CENTRAL NEBRASKA...A EXTENSION OF THE
ADVISORY/WARNING IS NEEDED THROUGH 03Z TO ACCOUNT FOR THE LATER
ENDING TIME OF SNOW AND GUSTY NORTHWEST WIND. COUNTIES MAY BE
DROPPED ACROSS OUR FAR SOUTH EARLY..BUT THE RECENT OB FROM KMCK
SUGGEST LIGHT TO OCCASIONAL MODERATE SNOW...WILL RE-EVALUATE IN THE
NEXT COUPLE HORUS. ELSEWHERE THE HEADLINES ARE ANTICIPATED TO BE
ALLOWED TO EXPIRE ON TIME.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 315 PM CST MON DEC 15 2014
MID RANGE...TUESDAY NIGHT THROUGH THURSDAY...IN THE MID
RANGE PERIODS...TEMPERATURES AND PRECIPITATION CHANCES ON WEDNESDAY
NIGHT ARE THE MAIN FORECASTING CHALLENGES IN THE MID RANGE PERIODS.
FOR TUESDAY NIGHT...A TROUGH OF LOW PRESSURE ALOFT WILL PUSH INTO
SRN CALIFORNIA RESULTING IN ANOTHER SOAKER FOR THE SWRN CONUS.
DOWNSTREAM OF THE TROUGH...LOW AMPLITUDE RIDGING WILL EXTEND ACROSS
THE SRN PLAINS INTO NEBRASKA. SURFACE HIGH PRESSURE WILL DOMINATE
THE PLAINS STATES AND OZARKS TUESDAY NIGHT. WITH FRESH
SNOWCOVER...LIGHT WINDS AND PARTLY CLOUDY SKIES...LOWS WILL BE COLD
IN THE SINGLE DIGITS AND LOWS WERE TRENDED DOWNWARD FROM THE
INHERITED FORECAST. FOR WEDNESDAY AND WEDNESDAY NIGHT...THE UPPER
LEVEL TROUGH WILL MIGRATE EAST INTO THE DESERT SOUTHWEST. SOME MODEL
DIFFERENCES WERE NOTED WITH THE FORWARD SPEED AND TRACK OF THIS
SYSTEM MIDWEEK. THE LATEST NAM AND ECMWF SOLNS FROM 12Z THIS MORNING
ACTUALLY DEVELOP A CLOSED LOW ALONG THE AZ/NM AND MEXICAN BORDER AT
00Z FRIDAY. THE GFS IS FASTER AND OPEN WITH THIS SYSTEM...MIGRATING
IT INTO NM AND WEST TX BY 00Z FRIDAY. WHAT ALL THREE MODELS DO
INDICATE IS A LEAD DISTURBANCE WHICH CROSSES THE SRN PLAINS INTO THE
OZARKS WEDNESDAY NIGHT. BOTH THE GFS AND ECMWF SOLNS LIFT INCREASED
LOW LEVEL MOISTURE INTO SRN NEBRASKA WEDNESDAY NIGHT IN ASSOCIATION
WITH THE LEAD DISTURBANCE. LIFT HOWEVER REMAINS WEAK PER CROSS
SECTIONS...AND WITH A FAIRLY DRY LAYER AROUND H7...AM NOT TOO
EXCITED ABOUT PCPN IN OUR AREA WEDS NIGHT. INHERITED FCST HAD A
SLIGHT CHANCE MENTION IN THE SOUTH AND SERN CWA DURING THE PERIOD
AND GIVEN THE LOW LEVEL MOISTURE AND SOME MODEL AGREEMENT BETWEEN
THE GFS AND ECMWF SOLNS...WILL LEAVE POP MENTION UNCHANGED FOR NOW.
AS FOR PTYPE WEDNESDAY NIGHT...LOOKING AT FCST SOUNDINGS...WAS
INITIALLY A LITTLE CONCERNED ABOUT THE THREAT FOR FREEZING DRIZZLE
IN THE SERN CWA. LOOKING AT BUFKIT SOUNDINGS...THE THREAT FOR FZDZ
SHOULD BE OFF TO THE SOUTHEAST OF THE FORECAST AREA AND WILL LEAVE
PRECIP MENTION AS ALL SNOW.
THURSDAY NIGHT THROUGH MONDAY...A TANDEM OF SRN STREAM WAVES WILL
TRACK ACROSS THE SRN TIER OF STATES FRIDAY...AND THEN AGAIN SUNDAY
NIGHT INTO MONDAY. ATTM...FAVORABLE FORCING FOR PRECIPITATION SHOULD
REMAIN SOUTH OF THE FORECAST AREA SO WILL FORECAST DRY CONDS ATTM.
HOWEVER...THE LATEST GFS SOLN BEGINS TO DIVERGE TOWARD A MORE ACTIVE
NRN STREAM NEXT WEEK...FORCING A CLIPPER SYSTEM THROUGH THE NRN
PLAINS EARLY NEXT WEEK...FOLLOWED BY SECOND...MUCH STRONGER NRN
STREAM SYSTEM AROUND CHRISTMAS EVE. IF THIS WOULD VERIFY...WE COULD
SEE COLD TEMPERATURES AND A POSSIBLE THREAT FOR SNOW. IN THE
MEANTIME...DECIDED TO KEEP CONDS DRY THROUGH THE WEEKEND AND INTO
NEXT WEEK...GIVEN THE ACTIVE SRN STREAM...WITH PCPN EXPECTED WELL
SOUTH OF THE FCST AREA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 528 PM CST MON DEC 15 2014
THE SNOW AND BLOWING SNOW ACROSS NCNTL NEB SHOULD EXIT THE FCST
AREA 03Z-06Z THIS EVENING. FROM 06Z-15Z...FOG IS EXPECTED TO
DEVELOP...MAINLY ALONG AND WEST OF HIGHWAY 61 WITH POTENTIAL FOR
LIFR. MVFR CIGS ARE EXPECTED DURING THE SAME TIME ALONG AND EAST
OF HIGHWAY 183. VFR IS EXPECTED ALL AREAS FROM 15Z TUESDAY ONWARD.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR
NEZ027>029.
WINTER STORM WARNING UNTIL 9 PM CST THIS EVENING FOR NEZ005>010-
025-026.
&&
$$
UPDATE...CDC
SYNOPSIS...CLB
SHORT TERM...JACOBS
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
529 PM CST MON DEC 15 2014
.SYNOPSIS...
ISSUED AT 315 PM CST MON DEC 15 2014
H5 ANALYSIS FROM EARLIER THIS MORNING HAD AN UPPER LEVEL
LOW OVER CENTRAL KS IN THE VICINITY OF SALINA WITH A TROUGH
EXTENDING SWD INTO THE ARKLATEX. DOWNSTREAM RIDGING WAS PRESENT
ACROSS THE EASTERN GREAT LAKES AND MID ATLANTIC STATES. NORTHWEST OF
THE CLOSED LOW...HIGH PRESSURE WAS PRESENT OVER NWRN ALBERTA...WHILE
A TROUGH OF LOW PRESSURE EXTENDED FROM THE GULF OF ALASKA SOUTH TO
JUST OFF THE COAST OF NRN CALIFORNIA. AS OF 2 PM CST...THE UPPER
LEVEL LOW HAD TRACKED FROM CENTRAL KS TO JUST NORTH OF CHILLICOTHE
MO. AT THE SURFACE...LOW PRESSURE WAS IN THE VICINITY OF LAMONI IOWA
WITH A COLD FRONT EXTENDING SSE INTO SOUTH CENTRAL MO. HIGH PRESSURE
WAS NOTED OVER EASTERN MT. ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA...STRONG NORTHERLY WINDS WERE PRESENT...ALONG WITH LIGHT
SNOW...WHICH AS REDUCED VISIBILITIES DOWN TO 1/2SM TO 2SM AS OF 2 PM
CST. UNDER CLOUDY SKIES...TEMPERATURES AS OF 2 PM CST RANGED
FROM...25 AT VALENTINE...TO 29 AT NORTH PLATTE...BROKEN BOW AND
OGALLALA.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 315 PM CST MON DEC 15 2014
FOR THE NEXT 36 HOURS...MAIN FORECAST CONCERNS REVOLVE
AROUND THE EXIT OF THE UPPER LEVEL SYSTEM THAT IS BRINGING
WIDESPREAD ACCUMULATING SNOW TO THE REGION. TEMPERATURE FORECAST
TONIGHT AND TOMORROW ALSO DESERVES CONSIDERATION.
FORECAST GUIDANCE INDICATES THE UPPER LOW WILL CONTINUE TO THE EAST
OVER THE UPPER MISSISSIPPI VALLEY...AND GET CAUGHT UP IN A NORTHERN
STREAM SHORTWAVE/UPPER LOW OVER THE NEXT 24 HOURS. LOW AMPLITUDE
TRANSITORY RIDGING WILL THEN TAKE HOLD ACROSS THE CENTRAL PLAINS AS
THE NEXT UPPER LEVEL TROUGH DEEPENS OVER THE WESTERN COAST. AT THE
SURFACE...CANADIAN HIGH PRESSURE WILL FILL SOUTH BEHIND THE
DEPARTING SURFACE LOW PROVIDING FOR DRIER CONDITIONS AND COOLER
TEMPERATURES. WITH CAA FILTERING SOUTH ACROSS THE
PLAINS...OVERNIGHT LOWS WILL BE CHILLY...GENERALLY IN THE SINGLE
DIGITS AND LOWER TEENS FROM WEST TO EAST ACROSS THE FORECAST AREA.
THE OVERNIGHT TEMPERATURE FORECAST IS A PRODUCT OF NUMERICAL
GUIDANCE WITH THE PREVIOUS FORECAST...WHICH ASSUMES SOME CLEARING.
IF SUBSTANTIAL CLEARING WERE TO OCCUR...TEMPERATURES MAY PLUMMET
ACROSS OUR WESTERN ZONES AS A FRESH SNOWPACK COMBINES WITH LIGHT
WINDS. HIGHS REBOUND SOME TUESDAY...BUT WITH CANADIAN HIGH PRESSURE
OVERHEAD...AND WEAK COLD AIR ADVECTION CONTINUING...HIGHS SHOULD
ONLY TOP OUT IN THE 20S FOR LOCATIONS ALONG AND NORTH OF
I80...POSSIBLY A FEW LOWER 30S COULD BE ACHIEVED ACROSS OUR SOUTH AS
THE WINDS BEGIN TO VEER TO THE SOUTH LATE IN THE DAY BEHIND THE HIGH.
CONCERNING PRECIPITATION...NEAR TERM GUIDANCE HAS ACCUMULATING
SNOWFALL OUT OF THE CWA...SAVE FOR THE NORTHEASTERN SANDHILLS AND
NORTH CENTRAL NEBRASKA BY 00Z THIS EVENING...WITH SNOW ENDING
GENERALLY AT 03Z FOR OUR FAR NORTHEAST. THE FORECAST USED A BLEND
OF THE 15.12Z NAM12 WITH THE LATEST RAP WHICH SEEMS TO PROVIDE A
PLAUSIBLE NORTHWEST TO EAST DEMISE OF THE SNOWFALL. IR
SATELLITE/RADAR TRENDS OVER THE PAST FEW HOURS EARLY AFTERNOON
SUPPORT THE IDEA AS CLOUD TOPS ARE WARMING AND REFLECTIVITY IS
BECOMING LESS DEFINED. SUPPOSE ANOTHER INCH OR TWO OF SNOW IS STILL
POSSIBLE ACROSS OUR NORTHERN ZONES LATE THIS AFTERNOON AS THE MODELS
SUGGEST QPF RATES OF UP TO FIVE HUNDREDTHS OF AN INCH PER HOUR
CONTINUING UNTIL 03Z. IMPACTS FROM ANY ADDITIONAL SNOW HOWEVER WILL
CONTINUE TO COMPOUND VISIBILITY ISSUES WITH BLOWING SNOW FROM THE
30-40 MPH GUSTS OCCURRING...WINDS WILL WEAKEN THOUGH AS THE PRESSURE
GRADIENT RELAXES THIS EVENING.
THE CURRENT WINTER STORM WARNING AND WINTER WEATHER ADVISORY WILL
EXPIRE AT 00Z THIS EVENING...BUT A FEW SMALL CHANGES MAYBE/ARE
NEEDED. ACROSS NORTH CENTRAL NEBRASKA...A EXTENSION OF THE
ADVISORY/WARNING IS NEEDED THROUGH 03Z TO ACCOUNT FOR THE LATER
ENDING TIME OF SNOW AND GUSTY NORTHWEST WIND. COUNTIES MAY BE
DROPPED ACROSS OUR FAR SOUTH EARLY..BUT THE RECENT OB FROM KMCK
SUGGEST LIGHT TO OCCASIONAL MODERATE SNOW...WILL RE-EVALUATE IN THE
NEXT COUPLE HORUS. ELSEWHERE THE HEADLINES ARE ANTICIPATED TO BE
ALLOWED TO EXPIRE ON TIME.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 315 PM CST MON DEC 15 2014
MID RANGE...TUESDAY NIGHT THROUGH THURSDAY...IN THE MID
RANGE PERIODS...TEMPERATURES AND PRECIPITATION CHANCES ON WEDNESDAY
NIGHT ARE THE MAIN FORECASTING CHALLENGES IN THE MID RANGE PERIODS.
FOR TUESDAY NIGHT...A TROUGH OF LOW PRESSURE ALOFT WILL PUSH INTO
SRN CALIFORNIA RESULTING IN ANOTHER SOAKER FOR THE SWRN CONUS.
DOWNSTREAM OF THE TROUGH...LOW AMPLITUDE RIDGING WILL EXTEND ACROSS
THE SRN PLAINS INTO NEBRASKA. SURFACE HIGH PRESSURE WILL DOMINATE
THE PLAINS STATES AND OZARKS TUESDAY NIGHT. WITH FRESH
SNOWCOVER...LIGHT WINDS AND PARTLY CLOUDY SKIES...LOWS WILL BE COLD
IN THE SINGLE DIGITS AND LOWS WERE TRENDED DOWNWARD FROM THE
INHERITED FORECAST. FOR WEDNESDAY AND WEDNESDAY NIGHT...THE UPPER
LEVEL TROUGH WILL MIGRATE EAST INTO THE DESERT SOUTHWEST. SOME MODEL
DIFFERENCES WERE NOTED WITH THE FORWARD SPEED AND TRACK OF THIS
SYSTEM MIDWEEK. THE LATEST NAM AND ECMWF SOLNS FROM 12Z THIS MORNING
ACTUALLY DEVELOP A CLOSED LOW ALONG THE AZ/NM AND MEXICAN BORDER AT
00Z FRIDAY. THE GFS IS FASTER AND OPEN WITH THIS SYSTEM...MIGRATING
IT INTO NM AND WEST TX BY 00Z FRIDAY. WHAT ALL THREE MODELS DO
INDICATE IS A LEAD DISTURBANCE WHICH CROSSES THE SRN PLAINS INTO THE
OZARKS WEDNESDAY NIGHT. BOTH THE GFS AND ECMWF SOLNS LIFT INCREASED
LOW LEVEL MOISTURE INTO SRN NEBRASKA WEDNESDAY NIGHT IN ASSOCIATION
WITH THE LEAD DISTURBANCE. LIFT HOWEVER REMAINS WEAK PER CROSS
SECTIONS...AND WITH A FAIRLY DRY LAYER AROUND H7...AM NOT TOO
EXCITED ABOUT PCPN IN OUR AREA WEDS NIGHT. INHERITED FCST HAD A
SLIGHT CHANCE MENTION IN THE SOUTH AND SERN CWA DURING THE PERIOD
AND GIVEN THE LOW LEVEL MOISTURE AND SOME MODEL AGREEMENT BETWEEN
THE GFS AND ECMWF SOLNS...WILL LEAVE POP MENTION UNCHANGED FOR NOW.
AS FOR PTYPE WEDNESDAY NIGHT...LOOKING AT FCST SOUNDINGS...WAS
INITIALLY A LITTLE CONCERNED ABOUT THE THREAT FOR FREEZING DRIZZLE
IN THE SERN CWA. LOOKING AT BUFKIT SOUNDINGS...THE THREAT FOR FZDZ
SHOULD BE OFF TO THE SOUTHEAST OF THE FORECAST AREA AND WILL LEAVE
PRECIP MENTION AS ALL SNOW.
THURSDAY NIGHT THROUGH MONDAY...A TANDEM OF SRN STREAM WAVES WILL
TRACK ACROSS THE SRN TIER OF STATES FRIDAY...AND THEN AGAIN SUNDAY
NIGHT INTO MONDAY. ATTM...FAVORABLE FORCING FOR PRECIPITATION SHOULD
REMAIN SOUTH OF THE FORECAST AREA SO WILL FORECAST DRY CONDS ATTM.
HOWEVER...THE LATEST GFS SOLN BEGINS TO DIVERGE TOWARD A MORE ACTIVE
NRN STREAM NEXT WEEK...FORCING A CLIPPER SYSTEM THROUGH THE NRN
PLAINS EARLY NEXT WEEK...FOLLOWED BY SECOND...MUCH STRONGER NRN
STREAM SYSTEM AROUND CHRISTMAS EVE. IF THIS WOULD VERIFY...WE COULD
SEE COLD TEMPERATURES AND A POSSIBLE THREAT FOR SNOW. IN THE
MEANTIME...DECIDED TO KEEP CONDS DRY THROUGH THE WEEKEND AND INTO
NEXT WEEK...GIVEN THE ACTIVE SRN STREAM...WITH PCPN EXPECTED WELL
SOUTH OF THE FCST AREA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 528 PM CST MON DEC 15 2014
THE SNOW AND BLOWING SNOW ACROSS NCNTL NEB SHOULD EXIT THE FCST
AREA 03Z-06Z THIS EVENING. FROM 06Z-15Z...FOG IS EXPECTED TO
DEVELOP...MAINLY ALONG AND WEST OF HIGHWAY 61 WITH POTENTIAL FOR
LIFR. MVFR CIGS ARE EXPECTED DURING THE SAME TIME ALONG AND EAST
OF HIGHWAY 183. VFR IS EXPECTED ALL AREAS FROM 15Z TUESDAY ONWARD.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR
NEZ004-022>024-035-036-056>058-069-094.
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ037-
038-059-070-071.
WINTER STORM WARNING UNTIL 9 PM CST THIS EVENING FOR NEZ005>010-
025-026.
WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR
NEZ027>029.
&&
$$
SYNOPSIS...CLB
SHORT TERM...JACOBS
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
450 PM MST MON DEC 15 2014
.AVIATION...
00Z TAF CYCLE
A RIDGE OF HIGH PRESSURE WILL CROSS ALOFT TONIGHT. THE CEILING
WILL GRADUALLY LOWER AS AN UPPER LEVEL TROUGH APPROACHES FROM THE
WEST TUESDAY AND TUESDAY NIGHT. WINTRY PRECIPITATION SHOULD
DEVELOP ALONG AND WEST OF THE CONTDVD LATE TUESDAY NIGHT WITH
FLIGHT CATEGORY RESTRICTIONS AND MT OBSCURATIONS.
44
&&
.PREV DISCUSSION...346 PM MST MON DEC 15 2014...
.SYNOPSIS...
HIGH CLOUDS WILL ONCE AGAIN STREAM IN FROM THE WEST THIS EVENING
THROUGH THE DAY TUESDAY. ANOTHER PACIFIC STORM SYSTEM AND THE
ASSOCIATED MOISTURE OUT AHEAD OF IT WILL BRING A FEW LIGHT SHOWERS
TO THE NORTHWEST THIRD OF THE STATE TUESDAY NIGHT. AS THE MAIN
STORM SYSTEM MOVES INTO ARIZONA WEDNESDAY EVENING...SCATTERED SHOWERS
AND SNOW SHOWERS ABOVE ABOUT 6000 FEET WILL SPREAD INTO WESTERN NEW
MEXICO. THE SHOWERS WILL SPREAD INTO CENTRAL NEW MEXICO THURSDAY.
SIGNIFICANT SNOW IS POSSIBLE OVER ALL MOUNTAIN AREAS. HIGH PRESSURE
RETURNS FOR FRIDAY AND SATURDAY WITH THE NEXT STORM SYSTEM
EXPECTED SUNDAY AND MONDAY.
&&
.DISCUSSION...
RIBBON OF STRONG NORTHWEST WINDS CONTINUE FROM THE SANDIA AND MANZANO
MOUNTAINS EAST TO CLINES CORNERS. RUC AND NAM BOTH INDICATING THESE
STRONG NW WINDS WILL DIMINISH RAPIDLY AROUND SUNSET. LEFT OUT MENTION
OF OVERNIGHT FOG OUTSIDE THE MORENO VALLEY GIVEN THAT NAMBUFR DATA
SUGGESTING THAT SCATTERED TO BROKEN MID CLOUDS WILL SPREAD FROM
SOUTHWEST TO NORTHEAST ACROSS WESTERN AND CENTRAL NEW MEXICO
TONIGHT...LIMITING RADIATIONAL COOLING. WEAK BACKDOOR COLD FRONT
EXPECTED TO SLIDE SWD INTO NE NM THIS EVENING. LOWERED OVERNIGHT
LOW TEMPERATURES A FEW DEGREES BELOW GUIDANCE FOR THE NE PLAINS AS
A RESULT. A BRIEF SPURT OF LIGHT EAST WINDS IS POSSIBLE INTO THE
MIDDLE RIO GRANDE VALLEY TUESDAY MORNING.
NAM AND GFS IN GOOD AGREEMENT THAT THE OVERHEAD RIDGE AXIS WILL SHIFT
EAST OF NM LATE TONIGHT/TUESDAY MORNING. INCREASING SOUTHWEST FLOW
ALOFT WILL RESULT IN SLIGHT WARMING FOR TUESDAY BUT PLENTIFUL HIGH
CLOUDS WILL KEEP THE WARMING IN CHECK.
MODELS IN FAIRLY GOOD AGREEMENT REGARDING THE NEXT UPPER LEVEL
TROUGH/CLOSED LOW FOR WEDNESDAY AND THURSDAY. SUB-TROPICAL JET
STREAM SPEED MAXIMA MOVE UP FROM THE SOUTHWEST TUESDAY NIGHT AND
WEDNESDAY MORNING...BRINGING CHANCES FOR SHOWERS AND SNOW SHOWERS
ABOVE ABOUT 6500FT OVER THE NORTHWEST THIRD OR SO OF THE STATE.
GFS AND NAM STILL AT ODDS WITH ONE ANOTHER AS TO WHEN TO BRING
THE MAIN TROUGH./CLOSED LOW THROUGH THE STATE AND WHEN BEST
CHANCES FOR PRECIP WILL BE WEDNESDAY OR THURSDAY. SIGNIFICANT SNOW
IS POSSIBLE OVER ALL MOUNTAIN AREAS WEDNESDAY NIGHT OR THURSDAY
GIVEN THE PWAT AMOUNT AVAILABLE. FUTURE MODEL RUNS SHOULD COME TO BETTER
AGREEMENT WITH REGARD TO TIMING BUT FOR NOW HAVE ADVISORY SNOW
AMOUNTS ABOVE ABOUT 7000FT WEDNESDAY NIGHT AND THURSDAY IN THE
GRIDS.
GFS STARTED WITH 06Z RUN LAST NIGHT BUT NOW ALL GLOBAL MODELS
TRENDING AWAY FROM A SLOW MOVING CLOSED LOW FOR THE WEEKEND. BOTH GFS
AND ECMWF TRENDING TOWARD A MUCH MORE PROGRESSIVE TROUGH. SLIGHT
VARIATIONS IN THE EXCEPTIONALLY FAST (185-190KT) PACIFIC JET
STREAM OVER THE CENTRAL PACIFIC ARE LEADING TO LARGE RUN TO RUN
MODEL DIFFERENCES. LOW CONFIDENCE IN THE FORECAST BEYOND FRIDAY
CONTINUES WITH SUCH BIG RUN TO RUN SWINGS. OVERALL PATTERN REMAINS
ACTIVE BUT STRENGTH OF SYSTEMS REMAINS IN QUESTION AT THIS TIME.
33
&&
.FIRE WEATHER...
POOR VENTILATION TODAY...BUT SOME IMPROVEMENT FORECAST TUESDAY INTO
WEDNESDAY AS AN UPPER LEVEL RIDGE AXIS SHIFTS EAST OF THE AREA AND
WINDS THROUGHOUT THE COLUMN RESPOND TO A TROUGH PROGRESSING EASTWARD
INTO THE DESERT SW AND GREAT BASIN. ALTHOUGH VENT RATES WILL TREND
UP TO FAIR/GOOD MOST AREAS BY WEDNESDAY...POCKETS OF POOR WILL STILL
REMAIN IN SOME VALLEYS.
ANOTHER WETTING EVENT LOOKS ON TRACK FOR WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT...ESPECIALLY ACROSS WESTERN AND NORTH CENTRAL
PORTIONS OF THE AREA. THE 12Z MODEL SOLUTIONS ARE SHOWING A MESSY
TROUGH PASSAGE SCENARIO WITH SEVERAL SHORTWAVE TROUGHS IMPACTING THE
PASSAGE OF AN UPPER LEVEL LOW...WHICH IS DIFFERENT FROM YESTERDAY`S
12Z RUNS. THE 18Z NAM SHOWS A WETTER SCENARIO WITH A MORE COHERENT
UPPER LEVEL LOW MOVING EAST ACROSS THE FORECAST AREA THURSDAY NIGHT.
POTENTIAL FOR A WIDESPREAD WETTING EVENT IS THERE...BUT FORECASTER
CONFIDENCE IS ONLY MODERATE AT THIS POINT GIVEN THE MODEL RUN-TO-RUN
INCONSISTENCY. VENT RATES WILL TAKE A HIT BEHIND THE DEPARTING
TROUGH THROUGH SATURDAY BEFORE IMPROVING AGAIN.
FORECAST UNCERTAINTY FOR A LATE WEEKEND AND EARLY NEXT WEEK WETTING
EVENT HAS INCREASED GIVEN THE 12Z MEDIUM RANGE MODEL SOLUTIONS...
WHICH LOOK MUCH DIFFERENT THAN THE 00Z RUNS...ESPECIALLY THE GFS
WHICH IS NOW SHOWING A PROGRESSIVE OPEN WAVE. REGARDLESS...MODERATE
TO HIGH FORECASTER CONFIDENCE ON THE UNSETTLED AND POTENTIALLY WET
PATTERN PERSISTING THROUGH EARLY NEXT WEEK.
11
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1105 PM MST SAT DEC 13 2014
.AVIATION...
06Z TAF CYCLE
A DEEPENING UPPER LEVEL TROUGH WILL CONTINUE TO FORM A CLOSED LOW
OVER CENTRAL NM TONIGHT...BEFORE GRADUALLY EJECTING NEWD ACROSS
THE TX/OK PANHANDLES ON SUNDAY. THE SYSTEM WILL CONTINUE TO PUSH A
WAVE OF PCPN WITH A PACIFIC COLD FRONT AND MVFR/IFR CONDITIONS IN
RAIN/SNOW AND MT OBSCURATIONS NEWD FROM THE CENTRAL MT CHAIN
ACROSS THE E PLAINS TONIGHT. WRAP AROUND SNOW SHOWERS AND MT
OBSCURATIONS SHOULD ALSO IMPACT WESTERN AND CENTRAL AREAS AT TIMES FOR
THE REMAINDER OF TONIGHT. IN ADDITION POCKETS OF MVFR/IFR
CONDITIONS SHOULD PERSIST INTO EARLY SUNDAY MORNING IN MANY
LOCATIONS W OF THE CENTRAL MT CHAIN DUE TO FOG AND LOW
CLOUDS...ESPECIALLY IN LOCATIONS THAT ACCUMULATED PCPN EARLIER IN
THE EVENING AND/OR OVERNIGHT. ON SUNDAY...WRAP AROUND SNOW AND RAIN SHOWERS
WILL FAVOR LOCATIONS N OF I-40 AND ALONG/E OF THE CONTDVD. SOME
OF THIS WRAP AROUND PCPN COULD BRIEFLY IMPACT KABQ...KSAF...KLVS
AND KTCC. ANOTHER SIGNIFICANT WEATHER CONCERN ON SUNDAY WILL BE
STRONG TO SEVERE NW WINDS IN THE WAKE OF THE EXITING UPPER LOW.
THE STRONGEST WINDS SHOULD BE FOUND E OF THE SANDIA AND MANZANO
MOUNTAINS TO THE TX BORDER WHERE OCCASIONAL GUSTS TO 50 KT ARE
EXPECTED. BLOWING SNOW COULD CREATE MVFR/IFR CONDITIONS IN THE
N MTS SUNDAY...EVEN DURING PERIODS OF NO PCPN.
44
&&
.PREV DISCUSSION...912 PM MST SAT DEC 13 2014...
.UPDATE...
LATEST MET MOS CAME IN WITH EVEN STRONGER WINDS FOR SUNDAY AS A
POWERFUL 60 KNOTS 700-50MB JET SLAMS EAST WITHIN THE BASE OF THE
DEEPENING UPPER LOW. MAIN AREA OF SNOW WILL BE OVER FOR AREAS ON
THE SOUTH SIDE FROM SANDIAS EAST TO CLINES CORNERS SO WILL END
WINTER HIGHLIGHT AT 12Z...THEN BEGIN HIGH WIND WARNING AFTER 14Z.
MAIN CONCERN WILL CERTAINLY BE THE WIND SUNDAY...WITH SOME BLSN
A POSSIBILITY. UPDATES AND NEW PRODUCT HIGHLIGHTS OUT SHORTLY.
GUYER
&&
.PREV DISCUSSION...547 PM MST SAT DEC 13 2014...
.UPDATE...
FOCUSED GREATEST POPS AND RAIN/SNOW CHANGEOVER WITH CURRENT TIMING
OF COLD FRONTAL BOUNDARY THROUGH TONIGHT. 12Z/18Z MODEL SUITE AND
LATEST SPC HRRR AND LOCAL 5KM WRF INDICATE A DYNAMIC EVENING ON
TAP FOR THE REGION. MAIN CHANGES WERE TO CONVERT SHOWER WORDING TO
STRATIFORM WORDING AND INCREASE INTENSITY FOR MTN AREAS. CURRENT
WINTER HIGHLIGHTS LOOK GOOD...ALTHOUGH CONCERNED TAOS AREA MAY GET
CLOSE TO WARNING IMPACTS. OTHERWISE...THE SANGRES LOOK TO BE IN
THE CROSS HAIRS THRU NOON SUNDAY WITH 8 TO 12 INCHES AND LOCALLY
UP TO 16...PARTICULARLY ON WEST AND NW FACING ASPECTS. OVERNIGHT
SHIFT WILL LIKELY ADD SOME WIND HIGHLIGHTS FOR TOMORROW AS STRONG
NW FLOW RACES OVER THE REGION BEHIND THE DEPARTING UPPER LOW.
GUYER
&&
.PREV DISCUSSION...233 PM MST SAT DEC 13 2014...
.SYNOPSIS...
A ROUND OF WEEKEND WINTER WEATHER FOR NEW MEXICO WILL CLEAR IN
TIME FOR THE WORK WEEK NEXT WEEK...WITH THE NEXT ROUND OF WINTER
WEATHER DUE IN BY MIDWEEK. A SERIES OF NORTH PACIFIC DISTURBANCES
WILL EXTEND THIS WINTER VISIT...WITH SKIES CLEARING ON FRIDAY.
ANOTHER SIZABLE WINTER STORM IS HEADED FOR NEW MEXICO LATE NEXT
WEEKEND.
&&
.DISCUSSION...
CURRENTLY...HIGH AMPLITUDE SHARP TROUGH EXTENDING FROM WESTERN
CANADA ACROSS ARIZONA TO NORTHERN MEXICO WITH ACCOMPANYING SURFACE
COLD FRONT ALONG THE WESTERN BORDER OF NEW MEXICO WILL BE THE
WEATHER PLAYER FOR THE REMAINDER OF THE WEEKEND...AS NEW MEXICO
BRACES FOR A ROUND OF RAIN AND SNOW.
MODELS...IN REASONABLE AGREEMENT ON BASIC STORY THROUGH THE
UPCOMING WORK WEEK AND INTO THE PRE HOLIDAY WEEKEND. TROUGH FROM
WESTERN CANADA TO NORTHERN MEXICO WILL SPREAD INTO WESTERN NEW
MEXICO THIS EVENING...DEEPEN AROUND A CLOSED LOW OVER NORTHERN NEW
MEXICO OVERNIGHT TONIGHT...AND SHEAR RAPIDLY INTO THE CENTRAL
PLAINS STATES THROUGH SUNDAY AFTERNOON. NORTHWEST FLOW ON
DOWNSTREAM LIMB OF HIGH AMPLITUDE RIDGE WILL PROVIDE A COUPLE OF
DAYS BREATHER IN ADVANCE OF LARGE SCALE PACIFIC TROUGH SYSTEM
DRIFTING INTO WESTERN NEW MEXICO BY WEDNESDAY. A QUICK WEDNESDAY
SHORTWAVE WILL BE FOLLOWED BY A MORE SUBSTANTIAL SYSTEM MOVING
INTO WESTERN NEW MEXICO ON THURSDAY...BUT MODELS ARE INTERESTING A
NEW WRINKLE ON PROJECTED SYSTEM PATH. BOTH HAVE SLOWED EASTWARD
PROGRESS OF THIS STRONGER SYSTEM...AND INSTEAD ARE NOW DIGGING IT
WELL SOUTH INTO CENTRAL CHIHUAHUA AS RIDGE BUILDS WITH AUTHORITY
FROM THE SOUTHERN CALIFORNIA COAST TO THE CANADIAN ROCKIES. THIS
RIDGE WILL MOVE ACROSS NEW MEXICO FOR AT LEAST THE FIRST HALF OF
NEXT WEEKEND...AS THE NEXT STORM SYSTEM OUT OF THE NORTHERN
PACIFIC RAMS INTO SOUTHERN CALIFORNIA AND MAKES VERY SLOW PROGRESS
INTO NORTHERN MEXICO NEAR THE NEW MEXICO BOOT HEEL BY MONDAY
MORNING...LEAVING THE BULK OF NEW MEXICO UNDER THE LESS ACTIVE
NORTHERN LIMBS OF THE TROUGH HEADING INTO THE HOLIDAY WEEK. THIS
IS A CHANGE...AND FUTURE RUNS WILL BE WATCHED CLOSELY TO VERIFY
THAT THE MECHANICS OF THIS PATTERN CAN BE MAINTAINED WITH SOME
DEGREE OF RUN TO RUN CONTINUITY.
OVERNIGHT...COOLER AIR MOVING IN FROM THE WEST...WITH TEMPERATURES
5 TO 10 DEGREES BELOW THOSE OBSERVED SATURDAY MORNING. WESTERN
SHOWERS WILL CHANGE OVER TO SNOW AND EXPAND COVERAGE RAPIDLY TO
THE EAST BY SUNDAY MORNING. HEAVIEST SNOW WILL FOCUS ON THE SAN
JUAN...TUSAS...AND JEMEZ MOUNTAINS EARLY IN THE OVERNIGHT...WITH
SNOW COVERAGE PICKING UP OVER THE SANGRE DE CRISTO RANGE BY SUNDAY
MORNING...WITH THESE SPOTS CONTINUING UNDER A WINTER WEATHER
WARNING. AWAY FROM THE HIGH COUNTRY...MUCH OF THE WEST AND CENTRAL
WILL PICK UP SOME OVERNIGHT SNOWFALL...WITH REDUCED SNOWFALL OVER
THE RIO GRANDE VALLEY. DEEPENING SURFACE LOW OVER NORTHEAST NEW
MEXICO AND EASTERN COLORADO WILL PROVIDE SUPPORTING FORCING FOR
INCREASING WIND SPEEDS OVERNIGHT...WITH BREEZY TO WINDY CONDITIONS
OVER THE EAST SLOPES AND ADJACENT PLAINS OF THE CENTRAL MOUNTAIN
CHAIN...AND OVER THE CONTINENTAL DIVIDE BY SUNRISE ON SUNDAY.
SOUTHERN PORTIONS OF THE SANGRE DE CRISTO RANGE AND ADJACENT
PLAINS ALONG INTERSTATE 40 COULD SEE SOME BLOWING SNOW WITH POOR
VISIBILITIES.
FOR SUNDAY...MUCH COOLER BUT TEMPERATURES WITHIN A FEW DEGREES OF
MID DECEMBER NORMALS. STORM COVERAGE WILL CONTINUE OVER THE
STATE...WITH SOMEWHAT REDUCED INTENSITY SOUTH OF INTERSTATE
40...AND STORM FOCUS SHIFTING TO THE SANGRE DE CRISTO
RANGE...RATON RIDGE...AND ON INTO SOUTHEAST COLORADO. GUSTY WINDS
WILL SHIFT NORTHWEST AS THE STORM SYSTEM DEPARTS...WITH STRONG
WINDS CONTINUING OVER THE CONTINENTAL DIVIDE...AND OUT OVER THE
CENTRAL MOUNTAIN CHAIN EAST SLOPES AND ADJACENT SLOPES THROUGH
SUNDAY AFTERNOON. WITH THE LAST OF THE SNOW OVER NORTHERN AND
WESTERN NEW MEXICO...NORTHEAST NEW MEXICO WILL BE IN FOR THE MIXED
BAG OF MOUNTAIN SNOW...AND THUNDERSTORMS OVER THE PLAINS GENERALLY
FROM INTERSTATE 40 NORTH AND INTERSTATE 25 EAST. SNOWFALL RATES
WILL DROP OFF THROUGH THE DAY...WITH GREATEST SNOWFALL
ACCUMULATION OVER THE SANGRE DE CRISTO RANGE AND OUT OVER RATON
RIDGE. HAVE ADDED RATON RIDGE AND JOHNSON MESA AREA TO SUITE OF
SNOW ADVISORIES FOR THE DAY ON SUNDAY TO COVER SNOW ISSUES ON
INTERSTATE 25 CROSSING THE COLORADO LINE.
FOR MONDAY...LAST OF THE SNOW WILL BE OUT OF NORTHEAST NEW MEXICO
BY MONDAY DAYBREAK...LEAVING CLEARING SKIES AND NORTHWEST FLOW
OVER THE STATE. WARMING IN THE WEST AND STEADY TEMPERATURES IN THE
EAST WILL KEEP THE STATE NEAR MID DECEMBER NORMALS FOR THE DAY.
WEAKENING SURFACE PRESSURE GRADIENT WILL ALSO DROP WIND
SPEEDS THROUGH THE DAY.
FOR TUESDAY...RIDGE SHEARING ACROSS NEW MEXICO TO LEAVE STATE IN
BROAD SOUTHWEST FLOW INTO TUESDAY AFTERNOON. NEXT INBOUND TROUGH
TAKING SHAPE ON THE WEST COAST WILL MOVE TO THE WESTERN NEW MEXICO
BORDER TUESDAY NIGHT...AND KICK OFF THE NEXT ROUND OF UNSETTLED
WEATHER THROUGH THE NEXT SEVERAL DAYS. SOME TUESDAY AFTERNOON
SOUTHWEST BREEZES OVER THE NORTHEAST CORNER OF THE STATE...BUT
WIND SPEEDS GENERALLY MODEST ELSEWHERE DURING THE DAY...AND SPEEDS
GENERALLY SUBDUED GOING INTO TUESDAY NIGHT.
OUTLOOK...WEDNESDAY THROUGH FRIDAY...FIRST SHORTWAVE BURST OUT OF
ARIZONA WILL PUSH ACROSS NEW MEXICO ON WEDNESDAY WITH MORE
SUBSTANTIAL SYSTEM ARRIVING OVER THE STATE ON THURSDAY. SYSTEM
WILL CLEAR OFF TO THE EAST ON FRIDAY WITH SHOWER COVERAGE TAPERING
OFF. WITH MORE SOUTHERLY EXCURSION...SNOW COVERAGE THURSDAY MAY
SHOW SOME PREFERENCE FOR AREAS SOUTH OF INTERSTATE 40...WITH
REDUCED AMOUNTS OVER THE HIGH COUNTRY TO THE NORTH...AND THIS
TREND WILL BE WATCHED CAREFULLY IN THE DAYS TO COME.
OTHERWISE...VERY MODEST COOLING TREND WILL PUSH MOST SPOTS 3 TO 8
DEGREES BELOW MID DECEMBER NORMALS BY FRIDAY. WITH A LACK OF
STRONG SURFACE PRESSURE GRADIENTS...WIND SPEEDS WILL BE RUNNING ON
THE MODEST SIDE ALL THREE DAYS.
SHY
&&
.FIRE WEATHER...
A VERY ACTIVE WEATHER PATTERN WILL COMMENCE TODAY AND CONTINUE
THROUGH THE NEXT SEVEN DAYS. A VIGOROUS STORM SYSTEM AND STRONG
FRONTAL BAND OF PRECIPITATION WILL STRENGTHEN OVER WRN NM LATE THIS
AFTERNOON AND CONTINUE THROUGH SUNDAY MORNING. WETTING PRECIPITATION
IS EXPECTED OVER MUCH OF THE WESTERN HALF OF NEW MEXICO WITH
SIGNIFICANT SNOWFALL OVER THE NORTHERN MOUNTAINS AND PERHAPS THE
SANDIAS AND MANZANOS. PRECIPITATION WILL INCREASE IN COVERAGE AND
INTENSITY LATE THIS AFTERNOON INTO THIS EVENING OVER WESTERN
AREAS...SPREADING INTO CENTRAL NEW MEXICO AROUND MID-EVENING. SNOW
LEVELS WILL DROP RAPIDLY BEHIND THE ASSOCIATED SURFACE COLD FRONT.
DEEPENING SURFACE LOW OVER FAR NE NM WILL COMBINE WITH STRONG NW
WINDS NEAR MOUNTAIN TOP LEVEL TO CREATE WINDY CONDITIONS SUNDAY.
MAIN AREAS AFFECTED BY THE STRONGEST WINDS (LOCALLY AS HIGH AS 55
MPH) WILL BE THE SANDIA AND MANZANO MOUNTAINS EAST TO THE CENTRAL
HIGHLANDS FROM SUNDAY MORNING THROUGH SUNDAY EVENING. AREAS OF SNOW
AND BLOWING SNOW WILL DEVELOP SUNDAY MORNING IN THESE SAME AREAS.
TEMPERATURES SUNDAY WILL BE MUCH COLDER...WITH HIGHS BELOW AVERAGE
FOR THE FIRST TIME THIS MONTH.
A TRANQUIL WEATHER PATTERN UNDER A HIGH PRESSURE RIDGE/SW FLOW ALOFT
WILL MOVE IN FOR MONDAY AND TUESDAY. VENTILATION RATES WILL DROP TO
POOR ALL AREAS MONDAY AS THE LOW LEVEL COLD AIR WILL BE SLOW TO
MODIFY AND WARMER AIR ALOFT MOVES OVERHEAD. VENT RATES IMPROVE
TUESDAY AS SOUTHWEST WINDS INCREASE SOMEWHAT.
THE NEXT PACIFIC TROUGH APPROACHES FROM THE WEST TUESDAY NIGHT. GFS
AND ECMWF IN GOOD AGREEMENT THROUGH WEDNESDAY...BRINGING SCATTERED
SNOW SHOWERS TO MUCH OF WESTERN AND NWRN NM DURING THE DAY WEDNESDAY
INTO WEDNESDAY NIGHT. VENTILATION RATES CONTINUE TO IMPROVE
WEDNESDAY AS COLDER AIR ALOFT ASSOCIATED WITH THE TROUGH MOVES OVER.
MODELS BEGIN TO DIVERGE LATE IN THE WEEK WITH REGARD TO HOW FAR
SOUTH A TRAILING SYSTEM WILL TRACK FOR THE LATTER HALF OF THE WORK
WEEK.
33
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 AM MST SUNDAY FOR THE FOLLOWING
ZONES...NMZ502>506-521>523.
HIGH WIND WARNING FROM 7 AM TO 8 PM MST SUNDAY FOR THE FOLLOWING
ZONES...NMZ521>523-533>537.
WINTER WEATHER ADVISORY UNTIL 5 PM MST SUNDAY FOR THE FOLLOWING
ZONES...NMZ516>518.
WINTER STORM WARNING UNTIL 5 PM MST SUNDAY FOR THE FOLLOWING
ZONES...NMZ510>515.
WINTER WEATHER ADVISORY FROM 5 AM TO 5 PM MST SUNDAY FOR THE
FOLLOWING ZONES...NMZ527.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
912 PM MST SAT DEC 13 2014
.UPDATE...
LATEST MET MOS CAME IN WITH EVEN STRONGER WINDS FOR SUNDAY AS A
POWERFUL 60 KNOTS 700-50MB JET SLAMS EAST WITHIN THE BASE OF THE
DEEPENING UPPER LOW. MAIN AREA OF SNOW WILL BE OVER FOR AREAS ON
THE SOUTH SIDE FROM SANDIAS EAST TO CLINES CORNERS SO WILL END
WINTER HIGHLIGHT AT 12Z...THEN BEGIN HIGH WIND WARNING AFTER 14Z.
MAIN CONCERN WILL CERTAINLY BE THE WIND SUNDAY...WITH SOME BLSN
A POSSIBILITY. UPDATES AND NEW PRODUCT HIGHLIGHTS OUT SHORTLY.
GUYER
&&
.PREV DISCUSSION...547 PM MST SAT DEC 13 2014...
.UPDATE...
FOCUSED GREATEST POPS AND RAIN/SNOW CHANGEOVER WITH CURRENT TIMING
OF COLD FRONTAL BOUNDARY THROUGH TONIGHT. 12Z/18Z MODEL SUITE AND
LATEST SPC HRRR AND LOCAL 5KM WRF INDICATE A DYNAMIC EVENING ON
TAP FOR THE REGION. MAIN CHANGES WERE TO CONVERT SHOWER WORDING TO
STRATIFORM WORDING AND INCREASE INTENSITY FOR MTN AREAS. CURRENT
WINTER HIGHLIGHTS LOOK GOOD...ALTHOUGH CONCERNED TAOS AREA MAY GET
CLOSE TO WARNING IMPACTS. OTHERWISE...THE SANGRES LOOK TO BE IN
THE CROSS HAIRS THRU NOON SUNDAY WITH 8 TO 12 INCHES AND LOCALLY
UP TO 16...PARTICULARLY ON WEST AND NW FACING ASPECTS. OVERNIGHT
SHIFT WILL LIKELY ADD SOME WIND HIGHLIGHTS FOR TOMORROW AS STRONG
NW FLOW RACES OVER THE REGION BEHIND THE DEPARTING UPPER LOW.
GUYER
&&
.PREV DISCUSSION...508 PM MST SAT DEC 13 2014...
.AVIATION...
00Z TAF CYCLE
A DEEPENING UPPER LEVEL TROUGH WILL FORM A CLOSED LOW OVER CENTRAL
NM TONIGHT...BEFORE GRADUALLY EJECTING NEWD ACROSS THE TX/OK
PANHANDLES ON SUNDAY. THE SYSTEM WILL CONTINUE TO PUSH A WAVE OF
PCPN WITH A PACIFIC COLD FRONT AND MVFR/IFR CONDITIONS IN
RAIN/SNOW AND MT OBSCURATIONS EASTWARD ACROSS THE FORECAST AREA
TONIGHT. MESOSCALE MODELS DEPICT THE PCPN TAPERING OFF AT KGUP AND
KFMN AFT 04 OR 05Z...THEN AT KAEG/KABQ AROUND 09Z. HOWEVER...FLIGHT
CATEGORY RESTRICTIONS SHOULD PERSIST INTO EARLY SUNDAY MORNING DUE
TO FOG AND LOW CLOUDS. ON SUNDAY...WRAP AROUND MOISTURE WILL FAVOR
LOCATIONS N OF I-40 AND ALONG/E OF THE CONTDVD FOR PERSISTENT
LINGERING RAIN/SNOW. SOME OF THIS WRAP AROUND PCPN COULD IMPACT
KSAF...KLVS AND KTCC SUNDAY AFTN.
44
&&
.PREV DISCUSSION...233 PM MST SAT DEC 13 2014...
.SYNOPSIS...
A ROUND OF WEEKEND WINTER WEATHER FOR NEW MEXICO WILL CLEAR IN
TIME FOR THE WORK WEEK NEXT WEEK...WITH THE NEXT ROUND OF WINTER
WEATHER DUE IN BY MIDWEEK. A SERIES OF NORTH PACIFIC DISTURBANCES
WILL EXTEND THIS WINTER VISIT...WITH SKIES CLEARING ON FRIDAY.
ANOTHER SIZABLE WINTER STORM IS HEADED FOR NEW MEXICO LATE NEXT
WEEKEND.
&&
.DISCUSSION...
CURRENTLY...HIGH AMPLITUDE SHARP TROUGH EXTENDING FROM WESTERN
CANADA ACROSS ARIZONA TO NORTHERN MEXICO WITH ACCOMPANYING SURFACE
COLD FRONT ALONG THE WESTERN BORDER OF NEW MEXICO WILL BE THE
WEATHER PLAYER FOR THE REMAINDER OF THE WEEKEND...AS NEW MEXICO
BRACES FOR A ROUND OF RAIN AND SNOW.
MODELS...IN REASONABLE AGREEMENT ON BASIC STORY THROUGH THE
UPCOMING WORK WEEK AND INTO THE PRE HOLIDAY WEEKEND. TROUGH FROM
WESTERN CANADA TO NORTHERN MEXICO WILL SPREAD INTO WESTERN NEW
MEXICO THIS EVENING...DEEPEN AROUND A CLOSED LOW OVER NORTHERN NEW
MEXICO OVERNIGHT TONIGHT...AND SHEAR RAPIDLY INTO THE CENTRAL
PLAINS STATES THROUGH SUNDAY AFTERNOON. NORTHWEST FLOW ON
DOWNSTREAM LIMB OF HIGH AMPLITUDE RIDGE WILL PROVIDE A COUPLE OF
DAYS BREATHER IN ADVANCE OF LARGE SCALE PACIFIC TROUGH SYSTEM
DRIFTING INTO WESTERN NEW MEXICO BY WEDNESDAY. A QUICK WEDNESDAY
SHORTWAVE WILL BE FOLLOWED BY A MORE SUBSTANTIAL SYSTEM MOVING
INTO WESTERN NEW MEXICO ON THURSDAY...BUT MODELS ARE INTERESTING A
NEW WRINKLE ON PROJECTED SYSTEM PATH. BOTH HAVE SLOWED EASTWARD
PROGRESS OF THIS STRONGER SYSTEM...AND INSTEAD ARE NOW DIGGING IT
WELL SOUTH INTO CENTRAL CHIHUAHUA AS RIDGE BUILDS WITH AUTHORITY
FROM THE SOUTHERN CALIFORNIA COAST TO THE CANADIAN ROCKIES. THIS
RIDGE WILL MOVE ACROSS NEW MEXICO FOR AT LEAST THE FIRST HALF OF
NEXT WEEKEND...AS THE NEXT STORM SYSTEM OUT OF THE NORTHERN
PACIFIC RAMS INTO SOUTHERN CALIFORNIA AND MAKES VERY SLOW PROGRESS
INTO NORTHERN MEXICO NEAR THE NEW MEXICO BOOT HEEL BY MONDAY
MORNING...LEAVING THE BULK OF NEW MEXICO UNDER THE LESS ACTIVE
NORTHERN LIMBS OF THE TROUGH HEADING INTO THE HOLIDAY WEEK. THIS
IS A CHANGE...AND FUTURE RUNS WILL BE WATCHED CLOSELY TO VERIFY
THAT THE MECHANICS OF THIS PATTERN CAN BE MAINTAINED WITH SOME
DEGREE OF RUN TO RUN CONTINUITY.
OVERNIGHT...COOLER AIR MOVING IN FROM THE WEST...WITH TEMPERATURES
5 TO 10 DEGREES BELOW THOSE OBSERVED SATURDAY MORNING. WESTERN
SHOWERS WILL CHANGE OVER TO SNOW AND EXPAND COVERAGE RAPIDLY TO
THE EAST BY SUNDAY MORNING. HEAVIEST SNOW WILL FOCUS ON THE SAN
JUAN...TUSAS...AND JEMEZ MOUNTAINS EARLY IN THE OVERNIGHT...WITH
SNOW COVERAGE PICKING UP OVER THE SANGRE DE CRISTO RANGE BY SUNDAY
MORNING...WITH THESE SPOTS CONTINUING UNDER A WINTER WEATHER
WARNING. AWAY FROM THE HIGH COUNTRY...MUCH OF THE WEST AND CENTRAL
WILL PICK UP SOME OVERNIGHT SNOWFALL...WITH REDUCED SNOWFALL OVER
THE RIO GRANDE VALLEY. DEEPENING SURFACE LOW OVER NORTHEAST NEW
MEXICO AND EASTERN COLORADO WILL PROVIDE SUPPORTING FORCING FOR
INCREASING WIND SPEEDS OVERNIGHT...WITH BREEZY TO WINDY CONDITIONS
OVER THE EAST SLOPES AND ADJACENT PLAINS OF THE CENTRAL MOUNTAIN
CHAIN...AND OVER THE CONTINENTAL DIVIDE BY SUNRISE ON SUNDAY.
SOUTHERN PORTIONS OF THE SANGRE DE CRISTO RANGE AND ADJACENT
PLAINS ALONG INTERSTATE 40 COULD SEE SOME BLOWING SNOW WITH POOR
VISIBILITIES.
FOR SUNDAY...MUCH COOLER BUT TEMPERATURES WITHIN A FEW DEGREES OF
MID DECEMBER NORMALS. STORM COVERAGE WILL CONTINUE OVER THE
STATE...WITH SOMEWHAT REDUCED INTENSITY SOUTH OF INTERSTATE
40...AND STORM FOCUS SHIFTING TO THE SANGRE DE CRISTO
RANGE...RATON RIDGE...AND ON INTO SOUTHEAST COLORADO. GUSTY WINDS
WILL SHIFT NORTHWEST AS THE STORM SYSTEM DEPARTS...WITH STRONG
WINDS CONTINUING OVER THE CONTINENTAL DIVIDE...AND OUT OVER THE
CENTRAL MOUNTAIN CHAIN EAST SLOPES AND ADJACENT SLOPES THROUGH
SUNDAY AFTERNOON. WITH THE LAST OF THE SNOW OVER NORTHERN AND
WESTERN NEW MEXICO...NORTHEAST NEW MEXICO WILL BE IN FOR THE MIXED
BAG OF MOUNTAIN SNOW...AND THUNDERSTORMS OVER THE PLAINS GENERALLY
FROM INTERSTATE 40 NORTH AND INTERSTATE 25 EAST. SNOWFALL RATES
WILL DROP OFF THROUGH THE DAY...WITH GREATEST SNOWFALL
ACCUMULATION OVER THE SANGRE DE CRISTO RANGE AND OUT OVER RATON
RIDGE. HAVE ADDED RATON RIDGE AND JOHNSON MESA AREA TO SUITE OF
SNOW ADVISORIES FOR THE DAY ON SUNDAY TO COVER SNOW ISSUES ON
INTERSTATE 25 CROSSING THE COLORADO LINE.
FOR MONDAY...LAST OF THE SNOW WILL BE OUT OF NORTHEAST NEW MEXICO
BY MONDAY DAYBREAK...LEAVING CLEARING SKIES AND NORTHWEST FLOW
OVER THE STATE. WARMING IN THE WEST AND STEADY TEMPERATURES IN THE
EAST WILL KEEP THE STATE NEAR MID DECEMBER NORMALS FOR THE DAY.
WEAKENING SURFACE PRESSURE GRADIENT WILL ALSO DROP WIND
SPEEDS THROUGH THE DAY.
FOR TUESDAY...RIDGE SHEARING ACROSS NEW MEXICO TO LEAVE STATE IN
BROAD SOUTHWEST FLOW INTO TUESDAY AFTERNOON. NEXT INBOUND TROUGH
TAKING SHAPE ON THE WEST COAST WILL MOVE TO THE WESTERN NEW MEXICO
BORDER TUESDAY NIGHT...AND KICK OFF THE NEXT ROUND OF UNSETTLED
WEATHER THROUGH THE NEXT SEVERAL DAYS. SOME TUESDAY AFTERNOON
SOUTHWEST BREEZES OVER THE NORTHEAST CORNER OF THE STATE...BUT
WIND SPEEDS GENERALLY MODEST ELSEWHERE DURING THE DAY...AND SPEEDS
GENERALLY SUBDUED GOING INTO TUESDAY NIGHT.
OUTLOOK...WEDNESDAY THROUGH FRIDAY...FIRST SHORTWAVE BURST OUT OF
ARIZONA WILL PUSH ACROSS NEW MEXICO ON WEDNESDAY WITH MORE
SUBSTANTIAL SYSTEM ARRIVING OVER THE STATE ON THURSDAY. SYSTEM
WILL CLEAR OFF TO THE EAST ON FRIDAY WITH SHOWER COVERAGE TAPERING
OFF. WITH MORE SOUTHERLY EXCURSION...SNOW COVERAGE THURSDAY MAY
SHOW SOME PREFERENCE FOR AREAS SOUTH OF INTERSTATE 40...WITH
REDUCED AMOUNTS OVER THE HIGH COUNTRY TO THE NORTH...AND THIS
TREND WILL BE WATCHED CAREFULLY IN THE DAYS TO COME.
OTHERWISE...VERY MODEST COOLING TREND WILL PUSH MOST SPOTS 3 TO 8
DEGREES BELOW MID DECEMBER NORMALS BY FRIDAY. WITH A LACK OF
STRONG SURFACE PRESSURE GRADIENTS...WIND SPEEDS WILL BE RUNNING ON
THE MODEST SIDE ALL THREE DAYS.
SHY
&&
.FIRE WEATHER...
A VERY ACTIVE WEATHER PATTERN WILL COMMENCE TODAY AND CONTINUE
THROUGH THE NEXT SEVEN DAYS. A VIGOROUS STORM SYSTEM AND STRONG
FRONTAL BAND OF PRECIPITATION WILL STRENGTHEN OVER WRN NM LATE THIS
AFTERNOON AND CONTINUE THROUGH SUNDAY MORNING. WETTING PRECIPITATION
IS EXPECTED OVER MUCH OF THE WESTERN HALF OF NEW MEXICO WITH
SIGNIFICANT SNOWFALL OVER THE NORTHERN MOUNTAINS AND PERHAPS THE
SANDIAS AND MANZANOS. PRECIPITATION WILL INCREASE IN COVERAGE AND
INTENSITY LATE THIS AFTERNOON INTO THIS EVENING OVER WESTERN
AREAS...SPREADING INTO CENTRAL NEW MEXICO AROUND MID-EVENING. SNOW
LEVELS WILL DROP RAPIDLY BEHIND THE ASSOCIATED SURFACE COLD FRONT.
DEEPENING SURFACE LOW OVER FAR NE NM WILL COMBINE WITH STRONG NW
WINDS NEAR MOUNTAIN TOP LEVEL TO CREATE WINDY CONDITIONS SUNDAY.
MAIN AREAS AFFECTED BY THE STRONGEST WINDS (LOCALLY AS HIGH AS 55
MPH) WILL BE THE SANDIA AND MANZANO MOUNTAINS EAST TO THE CENTRAL
HIGHLANDS FROM SUNDAY MORNING THROUGH SUNDAY EVENING. AREAS OF SNOW
AND BLOWING SNOW WILL DEVELOP SUNDAY MORNING IN THESE SAME AREAS.
TEMPERATURES SUNDAY WILL BE MUCH COLDER...WITH HIGHS BELOW AVERAGE
FOR THE FIRST TIME THIS MONTH.
A TRANQUIL WEATHER PATTERN UNDER A HIGH PRESSURE RIDGE/SW FLOW ALOFT
WILL MOVE IN FOR MONDAY AND TUESDAY. VENTILATION RATES WILL DROP TO
POOR ALL AREAS MONDAY AS THE LOW LEVEL COLD AIR WILL BE SLOW TO
MODIFY AND WARMER AIR ALOFT MOVES OVERHEAD. VENT RATES IMPROVE
TUESDAY AS SOUTHWEST WINDS INCREASE SOMEWHAT.
THE NEXT PACIFIC TROUGH APPROACHES FROM THE WEST TUESDAY NIGHT. GFS
AND ECMWF IN GOOD AGREEMENT THROUGH WEDNESDAY...BRINGING SCATTERED
SNOW SHOWERS TO MUCH OF WESTERN AND NWRN NM DURING THE DAY WEDNESDAY
INTO WEDNESDAY NIGHT. VENTILATION RATES CONTINUE TO IMPROVE
WEDNESDAY AS COLDER AIR ALOFT ASSOCIATED WITH THE TROUGH MOVES OVER.
MODELS BEGIN TO DIVERGE LATE IN THE WEEK WITH REGARD TO HOW FAR
SOUTH A TRAILING SYSTEM WILL TRACK FOR THE LATTER HALF OF THE WORK
WEEK.
33
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 AM MST SUNDAY FOR THE FOLLOWING
ZONES...NMZ502>506-521>523.
HIGH WIND WARNING FROM 7 AM TO 8 PM MST SUNDAY FOR THE FOLLOWING
ZONES...NMZ521>523-533>537.
WINTER WEATHER ADVISORY UNTIL 5 PM MST SUNDAY FOR THE FOLLOWING
ZONES...NMZ516>518.
WINTER STORM WARNING UNTIL 5 PM MST SUNDAY FOR THE FOLLOWING
ZONES...NMZ510>515.
WINTER WEATHER ADVISORY FROM 5 AM TO 5 PM MST SUNDAY FOR THE
FOLLOWING ZONES...NMZ527.
&&
$$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1013 AM EST SUN DEC 14 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE AREA TO START THE WEEK RESULTING
IN SLOWLY RISING TEMPERATURES TODAY THROUGH TUESDAY. HIGH
TEMPERATURES WILL BE IN THE MID 30S TODAY AND THE MID 40S BY
TUESDAY. DESPITE THE HIGH PRESSURE...MOSTLY CLOUDY SKIES WILL REMAIN
IN PLACE THANKS TO SOME TRAPPED LOW-LEVEL MOISTURE. A LOW PRESSURE
SYSTEM WILL BRING RAIN ACROSS THE AREA ON TUESDAY...WITH A
TRANSITION TO SNOW BY WEDNESDAY INTO THURSDAY AS COLDER AIR ARRIVES
FOR THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE 12Z BUF SOUNDING SHOWS A VERY STRONG INVERSION IN PLACE...AND
IT WOULD BE A PRETTY NICE DAY WITH TEMPERATURES IN THE UPPER 40S
IF YOU CAN MANAGE TO GET UP TO 7000FT (ABOUT 775MB). HOWEVER...BENEATH
THIS IS LOTS OF MOISTURE...ESPECIALLY BENEATH 900 MB. THIS WILL
RESULT IN ANOTHER CLOUDY DAY ACROSS THE REGION...WITH NEAR STEADY
TEMPERATURES IN THE MID TO UPPER 30S. A 20 KT WNW FLOW AT 925MB IS
FORECAST TO DIMINISH THIS AFTERNOON AND FURTHER THIS EVENING WHICH
SHOULD CAUSE DRIZZLE TO EVENTUALLY TAPER OFF.
MESONET SHOWS A FEW SPOTS ACROSS HIGHER TERRAIN IN JEFFERSON/LEWIS
COUNTIES THAT IS BELOW FREEZING...WITH SOME PATCHY FREEZING
DRIZZLE POSSIBLE IN THESE AREAS FOR THE REMAINDER OF THE MORNING
HOURS. THERE IS ALSO SOME PRETTY DENSE FOG IN PLACE WITH A SURFACE
WIND SHIFT TO THE NORTHWEST LEADING TO MOISTURE CONVERGENCE IN THE
BOUNDARY LAYER.
GIVEN THAT THE INVERSION IS FORECAST TO REMAIN IN PLACE...SEE
LITTLE OPPORTUNITY FOR ANY CLEARING TODAY...WITH ANOTHER CLOUDY
DAY EXPECTED REGION-WIDE.
BY TONIGHT...EXPECT STRATUS DECK TO LARGELY REMAIN IN PLACE. MODELS
HINT AT THE POSSIBILITY FOR SOME BREAKS IN THE CLOUDS ACROSS THE
NORTH COUNTRY...WHICH IF THEY OCCUR WOULD RESULT IN MUCH COOLER
OVERNIGHT LOW TEMPERATURES INLAND FROM LAKE ONTARIO.
HOWEVER...CONFIDENCE IN THESE CLOUDS BREAKING UP REMAINS VERY LOW.
THUS HAVE KEPT OVERNIGHT LOWS UP AROUND FREEZING FOR MOST
LOCATIONS...WITH SOME 20S POSSIBLE IN THE NORTH COUNTRY. NOT
EXPECTING TO SEE MUCH DRIZZLE AGAIN TONIGHT FOR TWO REASONS...1/
LIGHTER WINDS TURNING SOUTHERLY BY MORNING WILL ELIMINATE THE
UPSLOPE ASPECT AND COULD PROMOTE A LITTLE DOWNSLOPE DRYING AND 2/
FORECAST SOUNDINGS INDICATE A SLIGHTLY WARMER LOW-LEVEL LAYER
GETTING TEMPERATURES ABOVE THE IDEAL RANGE FOR DRIZZLE FORMATION. WE
COULD SEE SOME PATCHY FOG DEVELOP ACROSS THE HIGHER TERRAIN OF THE
WESTERN SOUTHERN TIER...BUT CONFIDENCE IN A DENSE FOG REPEAT
PERFORMANCE IS LOW DUE TO THE LACK OF AN UPSLOPE COMPONENT TO THE
WIND.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
ON MONDAY A STRONG MID LEVEL RIDGE WILL CREST OVER THE LOWER LAKES
REGION. NORMALLY THIS WOULD BRING UNSEASONABLE WARMTH TO OUR REGION
GIVEN 850MB TEMPS OF NEAR +8C IN THE MORNING...HOWEVER WE WILL STILL
HAVE A VERY PERSISTENT AND STRONG LOW LEVEL INVERSION IN PLACE. THIS
WILL PREVENT WARMER TEMPERATURES FROM BEING REALIZED...AND WILL ALSO
HELP TO KEEP EXTENSIVE LOW LEVEL MOISTURE TRAPPED. THIS WILL LIKELY
KEEP THE SEMI-PERMANENT STRATUS DECK IN PLACE FOR MUCH OF THE
REGION. EXPECT HIGHS IN THE UPPER 30S ACROSS WESTERN NY WITH SOME
LOWER 40S POSSIBLE ALONG THE LAKE ERIE SHORE. THE NORTH COUNTRY WILL
REMAIN IN THE LOW TO MID 30S.
MONDAY NIGHT SOUTHERLY RETURN FLOW WILL INCREASE AS HIGH PRESSURE
DRIFTS TO THE EASTERN SEABOARD IN RESPONSE TO A STRONG TROUGH
SWINGING THROUGH THE MIDWEST. THIS WILL FINALLY BEGIN TO DISLODGE
THE STRATUS DECK...BUT JUST IN TIME FOR INCREASING MID LEVEL CLOUDS
AHEAD OF THE NEXT SYSTEM. A LEAD MID LEVEL SHORTWAVE AND 700MB JET
WILL BRING INCREASING ASCENT LATE ACROSS WESTERN NY...WITH SHOWERS
ARRIVING BEFORE DAYBREAK. TEMPERATURES WILL BEGIN TO RISE LATER
MONDAY NIGHT IN RESPONSE TO BETTER MIXING...SO EXPECT EVERYTHING TO
BE LIQUID WHEN IT ARRIVES.
TUESDAY AND TUESDAY NIGHT A STRONG MID LEVEL TROUGH WILL SWING
THROUGH THE GREAT LAKES AND BRING A PERIOD OF ORGANIZED LARGE SCALE
ASCENT AND DEEPER MOISTURE. A SURFACE LOW WILL TRACK ACROSS LOWER
MICHIGAN TUESDAY BEFORE REACHING SOUTHERN ONTARIO BY WEDNESDAY
MORNING. THE MID LEVEL TROUGH AND ASSOCIATED UPPER LEVEL DIVERGENCE
WILL BRING A FEW PERIODS OF RAIN SHOWERS MOVING FROM SOUTHWEST TO
NORTHEAST ACROSS THE AREA TUESDAY AND TUESDAY NIGHT. THE SURFACE
COLD FRONT WILL NOT ARRIVE UNTIL WEDNESDAY MORNING...AND FORECAST
PROFILES SUPPORT ALL RAIN AS PTYPE THROUGH THAT TIME. OVERALL QPF
APPEARS TO BE ON THE LIGHT SIDE...WITH A QUARTER TO THIRD OF INCH IN
MOST PLACES. THE WARMER TEMPERATURES...HIGHER DEWPOINTS...WIND AND
RAIN WILL MELT MOST IF NOT ALL OF THE SNOW THAT REMAINS ON THE
GROUND...BUT THERE IS NOT ENOUGH WATER IN THE SNOW PACK FOR ANY
FLOOD CONCERNS.
ON WEDNESDAY STEADY COLD ADVECTION BEHIND THE COLD FRONT WILL BRING
A SLOW DROP IN TEMPERATURES THOUGH THE DAY. MOST OF THE STEADIER
SHOWERS WILL FOCUS ON THE NORTH COUNTRY WHERE DEEPER MOISTURE AND
ASCENT REMAIN. RAIN SHOWERS WILL GRADUALLY MIX WITH WET SNOW...AND
MAY CHANGE TO MAINLY SNOW ACROSS HIGHER TERRAIN IN THE AFTERNOON.
FARTHER WEST EXPECT JUST A FEW SCATTERED RAIN AND SNOW SHOWERS FROM
THE FINGER LAKES WESTWARD. IT WILL BECOME BREEZY TO ALMOST WINDY IN
THE COLD ADVECTION REGIME BEHIND THE COLD FRONT...WITH GUSTS OF
30-35 KNOTS POSSIBLE ESPECIALLY EAST AND NORTHEAST OF THE LAKES.
WEDNESDAY NIGHT 850MB TEMPS CONTINUE TO DROP TO AROUND -8C TO -10C.
THIS WILL CHANGE ANY REMAINING PRECIP OVER TO ALL SNOW. IT WILL
BECOME COLD ENOUGH FOR SOME LIMITED LAKE RESPONSE EAST OF THE
LAKES...BUT THE SHALLOW NATURE OF THE COLD AIRMASS WILL KEEP LAKE
INSTABILITY RELATIVELY WEAK.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
ON THURSDAY THE LOW LEVEL FLOW WILL BECOME MORE NORTHWEST...WITH
TEMPS ALOFT JUST COLD ENOUGH TO CONTINUE TO SUPPORT SOME WEAK LAKE
EFFECT AND UPSLOPE SNOW SHOWERS. GIVEN THE WEAK INSTABILITY AND
SHORT FETCH ANY ACCUMULATIONS SHOULD BE VERY MINOR. THIS WILL SLOWLY
COME TO AN END THURSDAY NIGHT AS THE AIRMASS MODERATES AND BECOMES
TOO MILD TO SUPPORT A LAKE RESPONSE.
FRIDAY SHOULD BE MAINLY DRY AS A WEAK RIDGE OF HIGH PRESSURE EXTENDS
FROM NORTHWEST ONTARIO INTO THE LOWER LAKES. TEMPERATURES WILL
REMAIN IN THE COOL SIDE THURSDAY AND FRIDAY...JUST A LITTLE BELOW
AVERAGE FOR MID DECEMBER.
MODEL GUIDANCE BEGINS TO DIVERGE BY SATURDAY WITH THE GFS FASTER AND
FARTHER NORTHWEST WITH A SOUTHERN STREAM TROUGH MOVING THROUGH THE
OHIO VALLEY. THE ECMWF REMAINS SLOWER AND FARTHER SOUTH WITH THIS
FEATURE...AND THIS IS MORE IN LINE WITH THE PREVIOUS 12Z/13 GEFS
ENSEMBLE MEAN. FOR NOW WILL STICK WITH A DRY FORECAST ON SATURDAY IN
FAVOR OF A SLOWER SOLUTION. THIS SYSTEM WILL BEAR WATCHING HOWEVER
FOR NEXT WEEKEND AS THE PATTERN REMAINS SOMEWHAT FAVORABLE FOR THIS
SOUTHERN STREAM SYSTEM TO SUPPORT ANOTHER NORTHEAST COASTAL STORM.
THE CURRENT RUN OF THE ECMWF KEEPS ANY IMPACTS JUST SOUTH AND EAST
OF OUR REGION...BUT THIS IS STILL A WEEK AWAY AND EXPECT PLENTY OF
MODEL VARIATION OVER THE NEXT FEW DAYS.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
AT 15Z...CONDITIONS VARIED ACROSS THE REGION...BUT MOST TAF SITES
WERE IFR OR LOWER. ROC WAS A NOTABLE EXCEPTION...BUT GIVEN
SATELLITE TRENDS EXPECT THAT THIS BRIEF POCKET OF VFR CONDITIONS IS
VERY SMALL AND IT SOON WILL COME IN LINE WITH OTHER LOCATIONS.
FOR THIS MORNING...EXPECT BUF/IAG/ROC/JHW TO GENERALLY REMAIN
STEADY STATE...PERHAPS BOUNCING SLIGHTLY...BUT GENERALLY AVERAGING
NEAR THEIR 15Z OBS POINT. EXPECT A LOWERING TREND AT ART...WHERE
WINDS SHIFTING TO THE NW WILL ENHANCE BOUNDARY LAYER MOISTURE
CONVERGENCE AND LOWER CIGS/VSBY.
LATE THIS AFTERNOON/EVENING...EXPECT CIGS TO LOWER WITH THE WIND
SHIFT TO THE NORTHWEST. TRENDS OF THE HRRR AVIATION GUIDANCE
APPEAR TO CAPTURE THIS TREND WELL.
THE FORECAST IS MORE DIFFICULT TONIGHT...WITH WINDS DIMINISHING
AND EVENTUALLY GOING NEARLY CALM UP TO 850MB. THE LACK OF FLOW
WILL PROBABLY RESULT IN NO DRIZZLE...BUT ITS UNCERTAIN IF THIS
WILL ALLOW GROUND FOG TO DEVELOP...OR IF CONDITIONS WILL
ESSENTIALLY REMAIN STEADY STATE WITH PERSISTENT IFR CIGS. EITHER
WAY...EXPECT IFR OR LOWER CONDITIONS FOR MOST OF THE AREA...WITH
LOWER VSBY POSSIBLE. NAM/GFS/LAMP MOS GUIDANCE CONTINUES TO BE TOO
OPTIMISTIC WITH CONDITIONS...WITH THE LOWEST CIGS LIKELY TO BE AT
JHW DUE TO THE HIGHER TERRAIN. LOWEST FORECAST CONFIDENCE IS AT
BUF/ROC/IAG...WHERE THE HRRR HINTS AT THE POSSIBLE DEVELOPMENT OF
LIFR CIGS AND GROUND FOG.
OUTLOOK...
MONDAY...MVFR/IFR IMPROVING TO VFR.
TUESDAY...AREAS OF MVFR IN RAIN SHOWERS.
WEDNESDAY AND THURSDAY...VFR/MVFR WITH A CHANCE OF SNOW SHOWERS.
&&
.MARINE...
WINDS AND WAVES WILL DROP JUST BELOW SMALL CRAFT CONDITIONS LATER
THIS MORNING AS THE PRESSURE GRADIENT RELAXES ACROSS THE LOWER
LAKES. HIGH PRESSURE WILL MOVE ACROSS THE LOWER LAKES TO START THE
WEEK...WITH QUIET CONDITIONS EXPECTED. THE NEXT CHANCE FOR HIGHER
WINDS AND WAVES ACROSS THE LAKES WILL BE WEDNESDAY AS A LOW PRESSURE
SYSTEM MOVES ACROSS THE GREAT LAKES.
&&
.CLIMATE...
A RELATIVELY MILD PATTERN WILL CONTINUE THROUGH THE NEXT 10 DAYS OR
SO WITH ONLY RELATIVELY BRIEF INTRUSIONS OF COLDER AIR MOST NOTABLY
LATER THIS WEEK. ONE MORE SOUTHERN STREAM SYSTEM WILL BEAR WATCHING
FOR A POSSIBLE NORTHEAST STORM NEXT WEEKEND.
THERE ARE GROWING SIGNS THAT THIS RELATIVELY MILD PATTERN WILL COME
TO AN END TOWARDS THE END OF THE MONTH. GEFS AND NAEFS ENSEMBLES
OVER THE PAST SEVERAL DAYS CONTINUE TO SUPPORT A TREND OF LOWERING
NAO INDEX AND THE DEVELOPMENT OF A STRONGER POSITIVE PNA TYPE
PATTERN WITH A BUILDING WEST COAST RIDGE FORCING DOWNSTREAM TROUGH
AMPLIFICATION ACROSS THE CENTRAL AND EASTERN CONUS. IT APPEARS THIS
PATTERN WILL HAVE SOME STAYING POWER...SO EXPECT A TREND TOWARDS
MORE PERSISTENT MID WINTER COLD BY THE END OF THE MONTH. IT APPEARS
THIS PATTERN CHANGE WILL BEGIN IN EARNEST SOMETIME AROUND CHRISTMAS
DAY...PLUS OR MINUS A FEW DAYS. THERE ARE SOME SIGNS IN GEFS
ENSEMBLE MEMBERS THAT THE START OF THE PATTERN CHANGE MAY BE USHERED
IN WITH A SIGNIFICANT SYSTEM SOMEWHERE IN THE EASTERN CONUS. STAY
TUNED.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CHURCH
NEAR TERM...APFFEL/CHURCH
SHORT TERM...HITCHCOCK
LONG TERM...HITCHCOCK
AVIATION...APFFEL/CHURCH
MARINE...CHURCH
CLIMATE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
941 PM CST MON DEC 15 2014
.UPDATE...
ISSUED AT 940 PM CST MON DEC 15 2014
THERE IS SOME CLEARING WORKING INTO THE REGION FROM THE
NORTH...BUT ANOTHER AREA OF CLOUDS MOVING INTO THE REGION FROM THE
NORTHEAST. DID DECREASE SKY A BIT...BUT WILL CONTINUE THE MOSTLY
CLOUDY THINKING. WINDS WILL REMAIN ELEVATED...WHICH WILL KEEP
TEMPERATURES FROM BOTTOMING OUT WHETHER THERE ARE CLOUDS OR NO
CLOUDS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 330 PM CST MON DEC 15 2014
FORECAST CHALLENGE CONCERNS LINGERING PCPN CHANCES ACROSS THE SE
AND TEMPERATURES. MODELS OVERALL IN GOOD AGREEMENT AND WILL USE
BLEND FOR FORECAST.
DEFORMATION BAND OF PCPN FROM EXTREME SE ND INTO WEST CENTRAL MN
HAS SHOWN WEAKENING TREND AND HAS TRANSITION OVER TO ALL SNOW
WHICH LINES UP WELL WITH RUC SOUNDINGS. FORTUNATELY WEB CAMS
WITHIN HEAVIEST BAND INDICTED ONLY MINOR ACCUMULATIONS AND GOOD
VISIBILITY. AS SURFACE LOW PROPAGATES EAST THIS EVENING
DEFORMATION ZONE PCPN SHOULD FOLLOW WITH CONTINUED WEAKENING. WITH
EXPECTED TRENDS WILL EXPIRE CURRENT HEADLINES WITH FORECAST
ISSUANCE. GUSTY NORTH WINDS WHICH AT TIMES HAVE FLIRTED WITH
ADVISORY CRITERIA WILL CONTINUE TO DIMINISH THROUGH THE EVENING.
SOME BREAKS IN THE CLOUDS OCCURRING OVER MB LAKES REGION COULD WORK
INTO THE NORTHERN FA TONIGHT HOWEVER FOR THE MOST PART CLOUDS
SHOULD HOLD. CLOUDS AND WIND SHOULD OFF SET COLD ADVECTION WHICH
LEVELS OFF AFTER MIDNIGHT SO EXPECTING MINIMUMS A BIT ABOVE
SEASONAL AVERAGES.
HIGH PRESSURE PUSHES INTO THE REGION TUESDAY. COLUMN GRADUALLY
DRIES OUT HOWEVER W-NW FA MAY BE THE ONLY AREAS WITH ANY POTENTIAL
FOR SOLAR. THIS WILL LIMIT TEMPERATURE RECOVERY KEEPING MAXIMUM
TEMPERATURES BLO AVERAGE.
AS HIGH CONTINUES TO BUILD IN TOMORROW NIGHT DIMINISHING WINDS AND
CLEARING SHOULD ALLOW TEMPERATURES TO DROP INTO THE SINGLE DIGITS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 330 PM CST MON DEC 15 2014
HIGH PRESSURE WILL COVER FA WEDNESDAY AND DEGREE OF SOLAR WILL
IMPACT TEMPERATURES HOWEVER WITH COLD START TEMPERATURES WILL
STRUGGLE OUT OF THE TEENS.
COLUMN BEGINS TO RECOVER THURSDAY AND WITH SOLAR AND LACK OF SNOW
COVER TEMPERATURES SHOULD BE ABLE TO CLIMB BACK TO AVERAGE.
FOR THU NIGHT THROUGH MONDAY...KIND OF A MUDDLED MID LEVEL FLOW
PATTERN OVER THE NORTHERN PLAINS FOR FRI THRU SUNDAY. NOT MUCH UPPER
LEVEL ENERGY TO WORK WITH. AT THE SFC...BROAD HIGH PRESSURE REMAINS
ANCHORED OVER THE GREAT LAKES BUT STILL KEEPING SOME INFLUENCE OVER
THIS FA. THEREFORE ALTHOUGH MODELS KICK OUT SOME MINIMAL PCPN AT
TIMES WILL KEEP THIS PERIOD DRY. BY SUNDAY NIGHT INTO MONDAY WEST
COAST RIDGE STARTS TO BUILD UP A LITTLE RESULTING IN NORTHWEST FLOW
IN THIS AREA. SFC PATTERN STILL UNCERTAIN AND THEREFORE PCPN FIELDS
DIFFER QUITE A BIT BETWEEN MODELS. DESPITE THESE DIFFERENCES WILL
KEEP SOME CHANCES FOR LIGHT SNOW ON MONDAY WITH LOW PRESSURE IN THE
AREA. TEMPS LOOK TO STAY ABOVE NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 642 PM CST MON DEC 15 2014
STILL NOT TOO CONFIDENT WITH CLOUD TRENDS TONIGHT. HRRR/RAP
INDICATE THAT THE CLEARING WORKING DOWN FROM CANADA WILL CONTINUE
TO INFILTRATE THE REGION BRINGING CLEARING SKY OVERNIGHT. NOT SO
SURE ABOUT THIS CONSIDERING MODEL SOUNDINGS INDICATE HIGH LOW
LEVEL MOISTURE WITHIN COLD AIR ADVECTION (USUALLY LEADS TO
CONTINUED CLOUDS). WILL WATCH TRENDS...BUT WILL CONTINUE WITH
OVERALL STORY OF MVFR CIGS (BUT COULD BE BRIEF BREAKS).
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...VOELKER
LONG TERM...GODON/VOELKER
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
642 PM CST MON DEC 15 2014
.UPDATE...
ISSUED AT 642 PM CST MON DEC 15 2014
SNOWFALL IS WEAKENING ACROSS WEST CENTRAL MINNESOTA...AND GUIDANCE
INDICATES IT WILL END SHORTLY (AS FORCING PROPAGATES SOUTHEAST AND
DRIER AIR ADVECTS INTO THIS AREA). TRAVEL LIKELY HAZARDOUS ACROSS
THIS AREA INTO THE OVERNIGHT HOURS WITH A COUPLE INCHES OF SNOW ON
TOP OF ICE COVERED ROADS.
MAIN CHALLENGE TONIGHT WILL BE CLOUDS...AND WHETHER OR NOT THE
CLEARING IN CANADA WILL ADVECT INTO THIS REGION. THE HRRR/RAP SAY
YES (CLEARING WILL OCCUR). MODEL SOUNDINGS INDICATE LOW LEVEL
MOISTURE REMAINING HIGH...AND WITHIN COLD AIR ADVECTION REGIME
WOULD THINK CLOUDS REMAIN. WILL CONTINUE WITH THE IDEA OF CLOUDS
OVERNIGHT (ALBEIT WITH SOME POSSIBLE BREAKS). DID LOWER MIN TEMPS
A FEW DEGREES WITH CURRENT VALUES BELOW THE EXPECTED DIURNAL
CURVE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 330 PM CST MON DEC 15 2014
FORECAST CHALLENGE CONCERNS LINGERING PCPN CHANCES ACROSS THE SE
AND TEMPERATURES. MODELS OVERALL IN GOOD AGREEMENT AND WILL USE
BLEND FOR FORECAST.
DEFORMATION BAND OF PCPN FROM EXTREME SE ND INTO WEST CENTRAL MN
HAS SHOWN WEAKENING TREND AND HAS TRANSITION OVER TO ALL SNOW
WHICH LINES UP WELL WITH RUC SOUNDINGS. FORTUNATELY WEB CAMS
WITHIN HEAVIEST BAND INDICTED ONLY MINOR ACCUMULATIONS AND GOOD
VISIBILITY. AS SURFACE LOW PROPAGATES EAST THIS EVENING
DEFORMATION ZONE PCPN SHOULD FOLLOW WITH CONTINUED WEAKENING. WITH
EXPECTED TRENDS WILL EXPIRE CURRENT HEADLINES WITH FORECAST
ISSUANCE. GUSTY NORTH WINDS WHICH AT TIMES HAVE FLIRTED WITH
ADVISORY CRITERIA WILL CONTINUE TO DIMINISH THROUGH THE EVENING.
SOME BREAKS IN THE CLOUDS OCCURRING OVER MB LAKES REGION COULD WORK
INTO THE NORTHERN FA TONIGHT HOWEVER FOR THE MOST PART CLOUDS
SHOULD HOLD. CLOUDS AND WIND SHOULD OFF SET COLD ADVECTION WHICH
LEVELS OFF AFTER MIDNIGHT SO EXPECTING MINIMUMS A BIT ABOVE
SEASONAL AVERAGES.
HIGH PRESSURE PUSHES INTO THE REGION TUESDAY. COLUMN GRADUALLY
DRIES OUT HOWEVER W-NW FA MAY BE THE ONLY AREAS WITH ANY POTENTIAL
FOR SOLAR. THIS WILL LIMIT TEMPERATURE RECOVERY KEEPING MAXIMUM
TEMPERATURES BLO AVERAGE.
AS HIGH CONTINUES TO BUILD IN TOMORROW NIGHT DIMINISHING WINDS AND
CLEARING SHOULD ALLOW TEMPERATURES TO DROP INTO THE SINGLE DIGITS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 330 PM CST MON DEC 15 2014
HIGH PRESSURE WILL COVER FA WEDNESDAY AND DEGREE OF SOLAR WILL
IMPACT TEMPERATURES HOWEVER WITH COLD START TEMPERATURES WILL
STRUGGLE OUT OF THE TEENS.
COLUMN BEGINS TO RECOVER THURSDAY AND WITH SOLAR AND LACK OF SNOW
COVER TEMPERATURES SHOULD BE ABLE TO CLIMB BACK TO AVERAGE.
FOR THU NIGHT THROUGH MONDAY...KIND OF A MUDDLED MID LEVEL FLOW
PATTERN OVER THE NORTHERN PLAINS FOR FRI THRU SUNDAY. NOT MUCH UPPER
LEVEL ENERGY TO WORK WITH. AT THE SFC...BROAD HIGH PRESSURE REMAINS
ANCHORED OVER THE GREAT LAKES BUT STILL KEEPING SOME INFLUENCE OVER
THIS FA. THEREFORE ALTHOUGH MODELS KICK OUT SOME MINIMAL PCPN AT
TIMES WILL KEEP THIS PERIOD DRY. BY SUNDAY NIGHT INTO MONDAY WEST
COAST RIDGE STARTS TO BUILD UP A LITTLE RESULTING IN NORTHWEST FLOW
IN THIS AREA. SFC PATTERN STILL UNCERTAIN AND THEREFORE PCPN FIELDS
DIFFER QUITE A BIT BETWEEN MODELS. DESPITE THESE DIFFERENCES WILL
KEEP SOME CHANCES FOR LIGHT SNOW ON MONDAY WITH LOW PRESSURE IN THE
AREA. TEMPS LOOK TO STAY ABOVE NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 642 PM CST MON DEC 15 2014
STILL NOT TOO CONFIDENT WITH CLOUD TRENDS TONIGHT. HRRR/RAP
INDICATE THAT THE CLEARING WORKING DOWN FROM CANADA WILL CONTINUE
TO INFILTRATE THE REGION BRINGING CLEARING SKY OVERNIGHT. NOT SO
SURE ABOUT THIS CONSIDERING MODEL SOUNDINGS INDICATE HIGH LOW
LEVEL MOISTURE WITHIN COLD AIR ADVECTION (USUALLY LEADS TO
CONTINUED CLOUDS). WILL WATCH TRENDS...BUT WILL CONTINUE WITH
OVERALL STORY OF MVFR CIGS (BUT COULD BE BRIEF BREAKS).
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...VOELKER
LONG TERM...GODON/VOELKER
AVIATION...TG
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
922 PM EST MON DEC 15 2014
.SYNOPSIS...
OCCLUDED LOW PRESSURE WILL TRAVEL FROM THE MISSISSIPPI VALLEY TO
THE GREAT LAKES TONIGHT THROUGH TUESDAY. SHOWERS WILL DEVELOP
IN THE MOIST FLOW CIRCULATING AROUND THE LOW. PRECIPITATION WILL
END BY WEDNESDAY AS THE LOW TRAVELS EAST...WITH COLDER
TEMPERATURES ARRIVING ON A BRISK WESTERLY FLOW BEHIND THE LOW.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
SHOWERS HAVE FINALLY DEVELOPED INTO A BAND AS THEY ENTERED THE
FORECAST AREA. EXPECT THIS TO CONTINUE TO SWEEP EAST NORTHEAST
OVERNIGHT. RECENT HRRR AND RAP RUNS HAVE BEEN SUGGESTING THAT
ANOTHER AREA OF SHOWERS WILL DEVELOP AFTER 06Z AND MOVE NORTHEAST.
HAVE ADJUSTED POPS ACCORDINGLY. RAINFALL AMOUNTS WILL MOSTLY
REMAIN ON THE LIGHT SIDE. CLOUDS AND AND LACK OF TEMPERATURE
ADVECTION WILL RESULT IN LITTLE MOVEMENT TO TEMPERATURES THROUGH
THE NIGHT.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
LOW PRESSURE WILL BE PUSHING THROUGH THE GREAT LAKES ON TUESDAY. A
CHANCE OF SHOWERS WILL PERSIST IN THE RELATIVELY MOIST CYCLONIC
FLOW BEHIND THE LOW.
AS THE BRISK WESTERLY FLOW CONTINUES IN THE WAKE OF THE LOW NOW
OVER SOUTHEAST CANADA...DRIER AIR AT THE LEADING EDGE OF HIGH
PRESSURE WILL FILTER IN BY WEDNESDAY...BRINGING AN END TO
PRECIPITATION.
HIGH TEMPERATURES WILL STAY CLOSE TO 50 TUESDAY IN THE MILD REGIME
SURROUNDING THE DEPARTING LOW. COLDER HIGHS AROUND 40 ARE IN STORE
FOR WEDNESDAY AS COLD ADVECTION RESULTS IN A RETURN TO NEAR NORMAL
TEMPERATURES.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
FORECAST PERIOD BEGINS WITH THE MODELS IN AGREEMENT IN PLACING A
STRUNG OUT HIGH PRESSURE SYSTEM FROM THE NORTHERN PLAINS DOWN INTO
THE UPPER OHIO VALLEY. THE HIGH WILL DRIFT SLOWLY EASTWARD PROVIDING
DRY CONDITIONS THROUGH FRIDAY.
THE GFS CONTINUES WITH ITS STRUGGLES IN DEALING WITH ENERGY SWINGING
OUT OF THE LOWER MS VALLEY FRIDAY. AFTER WINDING UP A LOW AND
LIFTING IT N INTO THE REGION WITH YESTERDAYS RUN...THE GFS NOW TAKES
A QUICK MOVING SHEARED OUT H5 VORT INTO THE TN VALLEY AND SPREADS
PCPN INTO SOUTHERN PORTIONS OF THE REGION MUCH QUICKER THAN THE
OTHER MODELS FRIDAY NIGHT. THE ECMWF HAS BEEN CONSISTENT WITH ITS
SOLUTION OF A TAKING A SLOWER A MORE DEFINED SFC LOW INTO THE
CAROLINAS FRIDAY NIGHT INTO SATURDAY. WILL CONTINUE TO FOLLOW THE
ECMWF SOLUTION AS IT IS BACKED BY THE CONSENSUS OF THE MODELS.
SO BROUGHT SOME SLIGHT CHANCE/CHANCE POPS INTO SOUTHERN SECTIONS
LATE FRIDAY NIGHT. SINCE WE ARE ON THE EXTREME NRN EDGE..MOST OF THE
PCPN SHOULD FALL AS SNOW...BUT CANT RULE OUT SOME SLEET OR RAIN
MIXING IN. AS THE SFC PATTERN TRANSITIONS TO THE EAST COAST ON
SATURDAY...A H5 S/W SWINGING THRU WILL PROVIDE LIFT AND WILL PULL
PCPN ACROSS THE AREA. A CHANCE OF LIGHT SNOW WILL TRANSITION TO A
RAIN/SNOW MIX DURING THE DAY ON SATURDAY. A CHANCE OF SNOW WILL
LINGER INTO SATURDAY NIGHT AND EARLY SUNDAY.
HIGH PRESSURE WILL BUILD IN FOR THE LAST FEW DAYS OF THE FORECAST
PERIOD.
HIGHS THRU THE PERIOD WILL BE NEAR TO SLIGHTLY BELOW NORMAL. THEY
SHOULD RANGE IN THE 30S FOR THURSDAY. SOUTHERN LOCATIONS MIGHT MAKE
IT INTO THE 40S FRIDAY WHILE THE NORTH REMAINS IN THE 30S. COOLER
AIR WILL WORK BACK IN SATURDAY THRU MONDAY KEEPING HIGHS IN THE 30S.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
AN OCCLUDED FRONT WILL PUSH ACROSS THE REGION OVERNIGHT. THERE
WILL BE SCATTERED LIGHT SHOWERS BOTH AHEAD AND ALONG THIS
BOUNDARY. DO NOT EXPECT ANY PRECIPITATION TO CAUSE VISIBILITY
RESTRICTIONS. HOWEVER CEILINGS WILL LOWER TO MVFR AND EVENTUALLY
DROP BELOW 2000 FT. WINDS WILL SHIFT TO SOUTH WITH THE FRONTAL
PASSAGE. THE WINDS WILL VEER TO SOUTHWEST AND STRENGTHEN SOME
AFTER 12Z. MVFR CEILINGS WILL CONTINUE TO PREVAIL. SOME SHOWERS
WILL REMAIN POSSIBLE.
OUTLOOK...MVFR CEILINGS WILL CONTINUE TUESDAY NIGHT AND LIKELY
INTO WEDNESDAY MORNING. MVFR CEILINGS AND VISIBILITIES POSSIBLE
FRIDAY NIGHT INTO SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...CONIGLIO
NEAR TERM...
SHORT TERM...CONIGLIO
LONG TERM...SITES
AVIATION...
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
653 PM EST MON DEC 15 2014
.SYNOPSIS...
LOW PRESSURE IN THE CENTRAL PLAINS WILL MOVE ACROSS THE CENTRAL
GREAT LAKES REGION TUESDAY DRAGGING A FRONTAL SYSTEM ACROSS THE
REGION. HIGH PRESSURE WILL BUILD IN LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
NO SIGNIFICANT CHANGES FOR 630 UPDATE. TWEAKED CLOUD COVER AND
OVERNIGHT TEMPS SLIGHTLY.
ORIGINAL DISCUSSION...
MODELS SHOW LOW PRESSURE ACROSS IOWA AND NRN MO LATE THIS
AFTERNOON WITH THE AXIS OF AN UPPER RIDGE JUST TO OUR EAST.
SUBSIDENCE AHEAD OF THE APPROACHING LOW HAS ALLOWED THE CLOUDS TO
BREAK THROUGH THE AFTERNOON ACROSS MUCH OF THE AREA. THE PROGRESS
OF THE LOW HOWEVER WILL TAKE IT TO SRN LAKE MI OVERNIGHT WITH A
COLD FRONT/OCCLUDED FRONT SOUTHEAST INTO WESTERN OHIO BY 12Z.
PRECIP TO OUR WEST AHEAD OF THE SYSTEM SO FAR IS NOT TOO
IMPRESSIVE HOWEVER FOLLOWING THE HRRR NAM AND SREF...MODELS BRING
IN A SWATH OF RAIN THROUGH THE EVENING EXPANDING IT THROUGH THE
EVENING AND OVERNIGHT AS THE UPPER SYSTEM AND ASSOCIATED DYNAMICS
OVERSPREAD THE REGION. WILL HAVE CAT POPS FOR MOST...MOVING FROM
WEST TO EAST THROUGH THE NIGHT. LOWS GENERALLY UPPER 30S TO LOWER
40S.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/...
TUESDAY BEGINS WITH LOW PRESSURE OVER SRN LAKE MI WITH A
COLD/OCCLUDED FRONT NEAR A KTOL-KFDY-KCMH. EXPECTING RAIN TO BE
OCCURRING ACROSS NWRN PA FROM THE INITIAL SURGE FINALLY REACHING
THE AREA JUST BEFORE DAWN. CENTRAL COUNTIES...PRECIP COULD BEGIN
SPOTTY WITH A MARGINAL DRY SLOT ACROSS MUCH OF THE AREA. MOISTURE
WITH THE UPPER SYSTEM WILL BE MOVING INTO THE WEST. THE UPPER LOW
WILL MOVE ENE ACROSS THE CENTRAL LAKES DURING THE DAY WITH DEEP
MOISTURE AND WEAK COLD ADVECTION SPREADING ACROSS THE CWA. WILL
HAVE LIKELY POPS ACROSS THE AREA DURING THE DAY FOR RAIN. THE
UPPER TROUGH AXIS SHIFTS EAST THROUGH THE EVENING. AM THINKING
WESTERN COUNTIES COULD POSSIBLY SEE A FEW SHOWERS THROUGH THE
EVENING BUT WITH FORCING GONE TAPERED POPS WEST THROUGH THE
OVERNIGHT TO SLIGHT CHANCE. WINDS TURN OFF THE LAKE FOR THE SNOW
BELT TUESDAY NIGHT BUT 850MB TEMPS NOT LOW ENOUGH FOR LAKE
INSTABILITY. WILL HOLD ONTO CHANCE POPS GIVEN MOISTURE SOURCE BUT
NOT EXPECTING A LOT GIVEN FORCING EAST OF THE AREA. WEDNESDAY
HOWEVER...850MB TEMPS BEGIN TO DROP TO -6 TO -8C DURING THE DAY.
STILL...LES NOT INDICATED HOWEVER STILL THINK SNOW SHOWERS WILL
DEVELOP. WILL HAVE CHANCE POPS GOING TO LIKELY IN THE AFTERNOON.
WEDNESDAY NIGHT 850MB TEMPS DROP FURTHER TO -12C WITH ANOTHER
UPPER TROF CROSSING THE LAKE GIVEN THE ADDED DYNAMICS AM MORE
CONFIDENT IN SNOW SHOWERS ACROSS THE EAST LAKESHORE/SNOW
BELT...LASTING INTO EARLY THURSDAY.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH PRESSURE IS EXPECTED TO BE SHIFTING INTO THE EASTERN LAKES FRI
WHICH SHOULD BRING THE LAKE EFFECT SHSN TO AN END BY FRI NIGHT.
LITTLE ADDITIONAL ACCUMULATION IS LIKELY ON FRI.
THE MODELS START TO DIFFER INTO SAT ON WHERE AN UPPER LOW TRACKS
THUS AFFECTING THE TRACK OF A SURFACE LOW. THE GFS IS NOW SHOWING A
MUCH WEAKER SURFACE LOW WITH A BROAD AREA OF MOISTURE WORKING UP
THROUGH THE OH VALLEY MOSTLY FORCED BY THE UPPER TROUGH. THE ECMWF
HAS A MUCH STRONGER SOUTHERN STREAM UPPER LOW AND ASSOCIATED SURFACE
LOW. IN EITHER CASE THERE SHOULD BE PRECIP SPREADING NE ACROSS THE
CWA LATE SAT OR SAT NIGHT AND SHIFTING INTO MAINLY THE EAST SUN.
TEMPS ON THE EDGE FOR EITHER RAIN OR SNOW ON SAT BUT A LITTLE COLDER
AIR MOVING IN FOR SAT NIGHT AND SUN SHOULD LEAD TO MOSTLY SNOW THEN.
TEMPS DON`T LOOK TO GET COLD ENOUGH FOR LAKE EFFECT OF ANY
SIGNIFICANCE LATER SUN THEN HIGH PRESSURE IS EXPECTED TO MOVE OVER
THE AREA SUN NIGHT TO PROVIDE DRY CONDITIONS. ANOTHER UPPER TROUGH
IS PROGGED TO BE MOVING EAST INTO THE LAKE ERIE AREA BY LATE MON SO
THE DRY CONDITIONS MAY NOT LAST THRU THE DAY.
TEMPS DON`T APPEAR TO SHOW A LOT OF CHANGE SUN THRU MON.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
THE MVFR CEILINGS OVER NW PA AND NE OH EXPANDED BACK WEST TO CLE
AND WILL BEGIN TO DECREASE FROM THE WEST BY 03Z AS THE FLOW INCREASES.
AS THE RAIN MOVES INTO THE TOL AND FDY AREAS BY 05Z AND THEN
SPREADS EAST. THE CEILINGS WILL LOWER TO IFR WITH VISIBILITIES
NEAR 3SM AND THEN THE CEILINGS MAY IMPROVE TO AROUND 1500 FEET IN
THE AFTERNOON. SOME QUESTION ON THAT.
.OUTLOOK...NON VFR INTO TUE NIGHT IN RAIN SHOWERS AND ACROSS FAR NE
OH/NW PA ON WED AND THU IN LAKE EFFECT SNOW SHOWERS.
&&
.MARINE...
SE WINDS WILL START INCREASING TONIGHT AND VEER TO SW ON TUE THEN TO
WEST TUE NIGHT WHILE INCREASING TO 20 TO 30 KNOTS AS COLD AIR BEHIND
A SERIES OF COLD FRONTS SPREADS ACROSS THE AREA. THUS A SCA WILL BE
NEEDED STARTING TUE NIGHT. WEST TO NW WINDS WILL SLOWLY DECREASE
LATER WED THRU EARLY FRI SO THE SCA MAY HAVE TO BE UP UNTIL SOMETIME
THU NIGHT. HIGH PRESSURE OVER THE UPPER LAKES EARLY FRI WILL SETTLE
OVER THE NORTHERN PART OF THE LAKES FOR SAT WHILE A LOW TRACKS NE
ACROSS THE SE STATES TO THE DELMARVA AREA BY EARLY SUN. THIS SHOULD
LEAD TO AN INCREASING NE FLOW ON SAT...HOWEVER MODEL DIFFERENCES
MAKE IT UNCERTAIN WHETHER THE WINDS WILL GET INTO SCA CRITERIA.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...DJB/TK
SHORT TERM...TK
LONG TERM...ADAMS
AVIATION...KIELTYKA
MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
636 PM EST MON DEC 15 2014
.SYNOPSIS...
LOW PRESSURE IN THE CENTRAL PLAINS WILL MOVE ACROSS THE CENTRAL
GREAT LAKES REGION TUESDAY DRAGGING A FRONTAL SYSTEM ACROSS THE
REGION. HIGH PRESSURE WILL BUILD IN LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
NO SIGNIFICANT CHANGES FOR 630 UPDATE. TWEAKED CLOUD COVER AND
OVERNIGHT TEMPS SLIGHTLY.
ORIGINAL DISCUSSION...
MODELS SHOW LOW PRESSURE ACROSS IOWA AND NRN MO LATE THIS
AFTERNOON WITH THE AXIS OF AN UPPER RIDGE JUST TO OUR EAST.
SUBSIDENCE AHEAD OF THE APPROACHING LOW HAS ALLOWED THE CLOUDS TO
BREAK THROUGH THE AFTERNOON ACROSS MUCH OF THE AREA. THE PROGRESS
OF THE LOW HOWEVER WILL TAKE IT TO SRN LAKE MI OVERNIGHT WITH A
COLD FRONT/OCCLUDED FRONT SOUTHEAST INTO WESTERN OHIO BY 12Z.
PRECIP TO OUR WEST AHEAD OF THE SYSTEM SO FAR IS NOT TOO
IMPRESSIVE HOWEVER FOLLOWING THE HRRR NAM AND SREF...MODELS BRING
IN A SWATH OF RAIN THROUGH THE EVENING EXPANDING IT THROUGH THE
EVENING AND OVERNIGHT AS THE UPPER SYSTEM AND ASSOCIATED DYNAMICS
OVERSPREAD THE REGION. WILL HAVE CAT POPS FOR MOST...MOVING FROM
WEST TO EAST THROUGH THE NIGHT. LOWS GENERALLY UPPER 30S TO LOWER
40S.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
TUESDAY BEGINS WITH LOW PRESSURE OVER SRN LAKE MI WITH A
COLD/OCCLUDED FRONT NEAR A KTOL-KFDY-LCMH. EXPECTING RAIN TO BE
OCCURRING ACROSS NWRN PA FROM THE INITIAL SURGE FINALLY REACHING
THE AREA JUST BEFORE DAWN. CENTRAL COUNTIES...PRECIP COULD BEGIN
SPOTTY WITH A MARGINAL DRY SLOT ACROSS MUCH OF THE AREA. MOISTURE
WITH THE UPPER SYSTEM WILL BE MOVING INTO THE WEST. THE UPPER LOW
WILL MOVE ENE ACROSS THE CENTRAL LAKES DURING THE DAY WITH DEEP
MOISTURE AND WEAK COLD ADVECTION SPREADING ACROSS THE CWA. WILL
HAVE LIKELY POPS ACROSS THE AREA DURING THE DAY FOR RAIN. THE
UPPER TROUGH AXIS SHIFTS EAST THROUGH THE EVENING. AM THINKING
WESTERN COUNTIES COULD POSSIBLY SEE A FEW SHOWERS THROUGH THE
EVENING BUT WITH FORCING GONE TAPERED POPS WEST THROUGH THE
OVERNIGHT TO SLIGHT CHANCE. WINDS TURN OFF THE LAKE FOR THE SNOW
BELT TUESDAY NIGHT BUT 850MB TEMPS NOT LOW ENOUGH FOR LAKE
INSTABILITY. WILL HOLD ONTO CHANCE POPS GIVEN MOISTURE SOURCE BUT
NOT EXPECTING A LOT GIVEN FORCING EAST OF THE AREA. WEDNESDAY
HOWEVER...850MB TEMPS BEGIN TO DROP TO -6 TO -8C DURING THE DAY.
STILL...LES NOT INDICATED HOWEVER STILL THINK SNOW SHOWERS WILL
DEVELOP. WILL HAVE CHANCE POPS GOING TO LIKELY IN THE AFTERNOON.
WEDNESDAY NIGHT 850MB TEMPS DROP FURTHER TO -12C WITH ANOTHER
UPPER TROF CROSSING THE LAKE GIVEN THE ADDED DYNAMICS AM MORE
CONFIDENT IN SNOW SHOWERS ACROSS THE EAST LAKESHORE/SNOW
BELT...LASTING INTO EARLY THURSDAY.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH PRESSURE IS EXPECTED TO BE SHIFTING INTO THE EASTERN LAKES FRI
WHICH SHOULD BRING THE LAKE EFFECT SHSN TO AN END BY FRI NIGHT.
LITTLE ADDITIONAL ACCUMULATION IS LIKELY ON FRI.
THE MODELS START TO DIFFER INTO SAT ON WHERE AN UPPER LOW TRACKS
THUS AFFECTING THE TRACK OF A SURFACE LOW. THE GFS IS NOW SHOWING A
MUCH WEAKER SURFACE LOW WITH A BROAD AREA OF MOISTURE WORKING UP
THROUGH THE OH VALLEY MOSTLY FORCED BY THE UPPER TROUGH. THE ECMWF
HAS A MUCH STRONGER SOUTHERN STREAM UPPER LOW AND ASSOCIATED SURFACE
LOW. IN EITHER CASE THERE SHOULD BE PRECIP SPREADING NE ACROSS THE
CWA LATE SAT OR SAT NIGHT AND SHIFTING INTO MAINLY THE EAST SUN.
TEMPS ON THE EDGE FOR EITHER RAIN OR SNOW ON SAT BUT A LITTLE COLDER
AIR MOVING IN FOR SAT NIGHT AND SUN SHOULD LEAD TO MOSTLY SNOW THEN.
TEMPS DON`T LOOK TO GET COLD ENOUGH FOR LAKE EFFECT OF ANY
SIGNIFICANCE LATER SUN THEN HIGH PRESSURE IS EXPECTED TO MOVE OVER
THE AREA SUN NIGHT TO PROVIDE DRY CONDITIONS. ANOTHER UPPER TROUGH
IS PROGGED TO BE MOVING EAST INTO THE LAKE ERIE AREA BY LATE MON SO
THE DRY CONDITIONS MAY NOT LAST THRU THE DAY.
TEMPS DON`T APPEAR TO SHOW A LOT OF CHANGE SUN THRU MON.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
MIX OF CIGS RANGING FROM IFR TO VFR SHOULD CONTINUE TO TRY AND
IMPROVE INTO THE EVENING THEN CIGS AND VSBYS WILL DROP BACK INTO IFR
FROM WEST TO EAST AS RAIN SPREADS ACROSS THE AREA. THE RAIN IS
EXPECTED TO ARRIVE IN THE TOL AND FDY AREA BY LATE
EVENING...SPREADING ACROSS MFD...CLE AND CAK AROUND 05 TO 08Z AND
FINALLY INTO YNG AND ERI AROUND 08Z TO 11Z. WINDS SHOULD STAY 10
KNOTS OR LESS MOST OF THE TIME THRU 18Z TUE WHILE VEERING FROM SE TO
S OR SW THIS EVENING THRU MIDDAY TUE.
.OUTLOOK...NON VFR INTO TUE NIGHT IN RAIN SHOWERS AND ACROSS FAR NE
OH/NW PA ON WED AND THU IN LAKE EFFECT SNOW SHOWERS.
&&
.MARINE...
SE WINDS WILL START INCREASING TONIGHT AND VEER TO SW ON TUE THEN TO
WEST TUE NIGHT WHILE INCREASING TO 20 TO 30 KNOTS AS COLD AIR BEHIND
A SERIES OF COLD FRONTS SPREADS ACROSS THE AREA. THUS A SCA WILL BE
NEEDED STARTING TUE NIGHT. WEST TO NW WINDS WILL SLOWLY DECREASE
LATER WED THRU EARLY FRI SO THE SCA MAY HAVE TO BE UP UNTIL SOMETIME
THU NIGHT. HIGH PRESSURE OVER THE UPPER LAKES EARLY FRI WILL SETTLE
OVER THE NORTHERN PART OF THE LAKES FOR SAT WHILE A LOW TRACKS NE
ACROSS THE SE STATES TO THE DELMARVA AREA BY EARLY SUN. THIS SHOULD
LEAD TO AN INCREASING NE FLOW ON SAT...HOWEVER MODEL DIFFERENCES
MAKE IT UNCERTAIN WHETHER THE WINDS WILL GET INTO SCA CRITERIA.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...DJB/TK
SHORT TERM...TK
LONG TERM...ADAMS
AVIATION...ADAMS
MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1159 AM EST SUN DEC 14 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD SLOWLY EAST TODAY AND BE EAST OF THE AREA
BY THIS AFTERNOON. LOW PRESSURE WILL APPROACH FROM THE WEST AND BE
OVER LAKE ERIE BY TUESDAY EVENING. THE LOW WILL FORCE A COLD FRONT
EAST ACROSS THE AREA TUESDAY AFTERNOON AND EVENING. HIGH PRESSURE
WILL REMAIN NEARLY STATIONARY OVER MINNESOTA AND EXPAND EAST OVER
THE REGION BY FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WILL BE IN CONTROL OF THE LOCAL AREA THROUGH THE DAY
TODAY. HOWEVER...STRONG INVERSION WILL REMAIN PRESENT AS WARM AIR
ADVECTION TAKES PLACE MORE SO ALOFT THAN AT THE SURFACE. THIS WILL
KEEP THE LOW LEVEL MOISTURE TRAPPED UNDER THE INVERSION. LATEST
SOUNDINGS AND MODEL SOUNDINGS INDICATE DEEP LOW LEVEL MOISTURE
PRODUCING STRATUS DECK WILL REMAIN PERSISTENT THROUGH THE DAY TODAY.
DRIZZLE HAS REDEVELOPED AROUND THE CLE METRO AREA SO WILL ADD
MENTION BACK INTO THE FORECAST. HRRR SEEMS TO CONTINUE WITH PATCHY
DRIZZLE THRUT THE DAY FROM THE WEAK WARM ADVECTION LIFT SO WILL
FOLLOW SUIT IN THE FORECAST.
BUMPED UP TEMPERATURES ACROSS THE AREA...ESPECIALLY IN THE WEST
WHERE A BRIEF PEEK AT THE SUN COULD OCCUR THIS AFTERNOON AND HELP
BOOST TEMPERATURES. OTHERWISE...GENERALLY 40S FOR HIGHS TODAY AND
NEAR 50 IN THE WEST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
UPPER LEVEL RIDGE AND SURFACE HIGH PRESSURE WILL KEEP THE THREAT FOR
STRATUS DECK IN PLACE OVERNIGHT. WILL ALSO MENTION THE POTENTIAL FOR
PATCHY DRIZZLE AND PATCHY FOG DURING THE EVENING IN THE WEST AND
OVERNIGHT ELSEWHERE. SOME DRIER AIR WILL BEGIN TO PUSH INTO THE
WESTERN PORTIONS OVERNIGHT AND THIS SHOULD HELP TO LIFT SOME OF THE
STRATUS IN THAT AREA. NO GO FOR THE EASTERN TWO THIRDS OF THE AREA
THOUGH. TEMPERATURES STILL REMAIN ABOVE FREEZING AND THERE IS NO
RISK OF FREEZING PRECIPITATION.
MATTER OF FACT...IT LOOKS LIKE EVEN THOUGH WE START TO SEE SOME
DRIER AIR ON MONDAY...ELEVATED LOW LEVEL MOISTURE HOLDS STRONG TO
PREVENT ANY SUN SO WILL KEEP THE CLOUDY SKIES. NEXT SYSTEM BEGINS TO
APPROACH THE FORECAST AREA BY MONDAY EVENING AS LOW PRESSURE MOVES
NORTHEAST TO LAKE ERIE. THIS WILL FORCE A COLD FRONT ACROSS THE AREA
TUESDAY INTO TUESDAY EVENING. SHOWERS WITH THE COLD FRONT ARE
EXPECTED AS MOISTURE IN ASSOCIATION WITH THE STORM SYSTEM TRACKS
NORTHEAST INTO THE AREA.
ONCE COLD FRONT SLIDES EAST...IT WILL TAKE SOME TIME FOR THE COLDER
AIR TO ARRIVE. THIS SHOULD HOLD OFF UNTIL WEDNESDAY MORNING. LAKE
TEMPERATURE AND 850 MB TEMPERATURE DIFFERENCE IS MINIMAL BUT STILL
EXPECTING SOME LAKE EFFECT SNOW SHOWERS TO DEVELOP WITH SOME LIGHT
SNOW ACCUMULATIONS IN THE NORTHEAST WEDNESDAY INTO WEDNESDAY NIGHT.
MILD TEMPERATURES IN THE 40S FOR HIGHS EACH DAY WILL SETTLE BACK
INTO THE 30S ON WEDNESDAY. OVERNIGHT LOWS RETURN BACK TO THE 20S BY
WEDNESDAY NIGHT IN THE COLD AIR ADVECTION FLOW IN THE WAKE OF THE
LOW AND ADVANCE OF THE SURFACE HIGH PRESSURE.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
LOW PRESSURE WILL BE NEAR THE NEW ENGLAND COAST ON THURSDAY WITH
TEMPERATURES COLD ENOUGH TO PRODUCE SOME LAKE EFFECT SNOW SHOWERS
INTO THURSDAY NIGHT. HIGH PRESSURE SHOULD RIDGE INTO THE AREA FROM
CENTRAL ONTARIO KEEPING THE AREA DRY ON FRIDAY. MODELS THEN BEGIN
TO DIFFER ON THE HANDLING OF THE SOUTHERN JET STREAM LOW THAT
DEVELOPS OVER TEXAS ON FRIDAY. THE ECMWF TYPICALLY HANDLES STORM
SYSTEMS FROM THIS AREA OF THE COUNTRY BETTER THAN THE GFS. SO HAVE
LEANED TOWARD THE SLOWER ARRIVAL OF THE PRECIPITATION ON SATURDAY.
STILL WOULD NOT BE SURPRISED TO SEE THIS STORM SYSTEM EJECT
NORTHEASTWARD SLOWER THAN CURRENT THINKING.
TEMPERATURES FOR LONG TERM WE GENERALLY BE IN THE 20S FOR LOWS AND
30S FOR HIGHS.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
A HOLE IN THE STRATUS DECK ACROSS NRN INDIANA MAY AFFECT KTOL AND
KFDY AT SOME POINT THROUGH THE AFTERNOON BUT OTHERWISE EXPECT
MVFR/IFR STRATUS FOG AND HAZE TO FILL BACK IN THIS EVENING AND
OVERNIGHT. ELSEWHERE EXPECT WIDESPREAD LOW MVFR AND IFR TO PERSIST
THROUGH THE PERIOD.
.OUTLOOK...NON VFR LIKELY MONDAY. AREAS OF NON VFR TUESDAY IN
RAIN SHOWERS AND ACROSS FAR NE OH/NW PA ON WEDNESDAY IN LAKE
EFFECT SNOW SHOWERS.
&&
.MARINE...
SMALL CRAFT ADVISORY WILL CONTINUE THROUGH MID MORNING. WINDS AND
WAVES SHOULD AS HIGH PRESSURE WEAKENS AND BEGINS TO SLIDE EAST. LOW
PRESSURE WILL THEN BEGIN TO MOVE INTO THE CENTRAL GREAT LAKES ON
MONDAY WITH SOUTHERLY WINDS ANTICIPATED. THE SOUTHERLY WINDS WILL
INCREASE MONDAY NIGHT BUT WILL SHIFT TO THE WEST AND NORTHWEST IN
THE WAKE OF A COLD FRONT THAT SHOULD CROSS THE LAKE TUESDAY EVENING.
WINDS WILL INCREASE WITH THE COLD ADVECTION IN THE WAKE OF THE
FRONT. AT THIS POINT IT APPEARS WINDS WILL REMAIN IN THE 15 TO 25
KNOT RANGE SO A SMALL CRAFT ADVISORY WILL BE NEED TUESDAY NIGHT INTO
AT LEAST WEDNESDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...MULLEN
AVIATION...TK
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
923 AM EST SUN DEC 14 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD SLOWLY EAST TODAY AND BE EAST OF THE AREA
BY THIS AFTERNOON. LOW PRESSURE WILL APPROACH FROM THE WEST AND BE
OVER LAKE ERIE BY TUESDAY EVENING. THE LOW WILL FORCE A COLD FRONT
EAST ACROSS THE AREA TUESDAY AFTERNOON AND EVENING. HIGH PRESSURE
WILL REMAIN NEARLY STATIONARY OVER MINNESOTA AND EXPAND EAST OVER
THE REGION BY FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WILL BE IN CONTROL OF THE LOCAL AREA THROUGH THE DAY
TODAY. HOWEVER...STRONG INVERSION WILL REMAIN PRESENT AS WARM AIR
ADVECTION TAKES PLACE MORE SO ALOFT THAN AT THE SURFACE. THIS WILL
KEEP THE LOW LEVEL MOISTURE TRAPPED UNDER THE INVERSION. LATEST
SOUNDINGS AND MODEL SOUNDINGS INDICATE DEEP LOW LEVEL MOISTURE
PRODUCING STRATUS DECK WILL REMAIN PERSISTENT THROUGH THE DAY TODAY.
DRIZZLE HAS REDEVELOPED AROUND THE CLE METRO AREA SO WILL ADD
MENTION BACK INTO THE FORECAST. HRRR SEEMS TO CONTINUE WITH PATCHY
DRIZZLE THRUT THE DAY FROM THE WEAK WARM ADVECTIVE LIFT SO WILL
FOLLOW SUIT IN THE FORECAST.
BUMPED UP TEMPERATURES ACROSS THE AREA...ESPECIALLY IN THE WEST
WHERE A BRIEF PEEK AT THE SUN COULD OCCUR THIS AFTERNOON AND HELP
BOOST TEMPERATURES. OTHERWISE...GENERALLY 40S FOR HIGHS TODAY AND
NEAR 50 IN THE WEST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
UPPER LEVEL RIDGE AND SURFACE HIGH PRESSURE WILL KEEP THE THREAT FOR
STRATUS DECK IN PLACE OVERNIGHT. WILL ALSO MENTION THE POTENTIAL FOR
PATCHY DRIZZLE AND PATCHY FOG DURING THE EVENING IN THE WEST AND
OVERNIGHT ELSEWHERE. SOME DRIER AIR WILL BEGIN TO PUSH INTO THE
WESTERN PORTIONS OVERNIGHT AND THIS SHOULD HELP TO LIFT SOME OF THE
STRATUS IN THAT AREA. NO GO FOR THE EASTERN TWO THIRDS OF THE AREA
THOUGH. TEMPERATURES STILL REMAIN ABOVE FREEZING AND THERE IS NO
RISK OF FREEZING PRECIPITATION.
MATTER OF FACT...IT LOOKS LIKE EVEN THOUGH WE START TO SEE SOME
DRIER AIR ON MONDAY...ELEVATED LOW LEVEL MOISTURE HOLDS STRONG TO
PREVENT ANY SUN SO WILL KEEP THE CLOUDY SKIES. NEXT SYSTEM BEGINS TO
APPROACH THE FORECAST AREA BY MONDAY EVENING AS LOW PRESSURE MOVES
NORTHEAST TO LAKE ERIE. THIS WILL FORCE A COLD FRONT ACROSS THE AREA
TUESDAY INTO TUESDAY EVENING. SHOWERS WITH THE COLD FRONT ARE
EXPECTED AS MOISTURE IN ASSOCIATION WITH THE STORM SYSTEM TRACKS
NORTHEAST INTO THE AREA.
ONCE COLD FRONT SLIDES EAST...IT WILL TAKE SOME TIME FOR THE COLDER
AIR TO ARRIVE. THIS SHOULD HOLD OFF UNTIL WEDNESDAY MORNING. LAKE
TEMPERATURE AND 850 MB TEMPERATURE DIFFERENCE IS MINIMAL BUT STILL
EXPECTING SOME LAKE EFFECT SNOW SHOWERS TO DEVELOP WITH SOME LIGHT
SNOW ACCUMULATIONS IN THE NORTHEAST WEDNESDAY INTO WEDNESDAY NIGHT.
MILD TEMPERATURES IN THE 40S FOR HIGHS EACH DAY WILL SETTLE BACK
INTO THE 30S ON WEDNESDAY. OVERNIGHT LOWS RETURN BACK TO THE 20S BY
WEDNESDAY NIGHT IN THE COLD AIR ADVECTION FLOW IN THE WAKE OF THE
LOW AND ADVANCE OF THE SURFACE HIGH PRESSURE.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
LOW PRESSURE WILL BE NEAR THE NEW ENGLAND COAST ON THURSDAY WITH
TEMPERATURES COLD ENOUGH TO PRODUCE SOME LAKE EFFECT SNOW SHOWERS
INTO THURSDAY NIGHT. HIGH PRESSURE SHOULD RIDGE INTO THE AREA FROM
CENTRAL ONTARIO KEEPING THE AREA DRY ON FRIDAY. MODELS THEN BEGIN
TO DIFFER ON THE HANDLING OF THE SOUTHERN JET STREAM LOW THAT
DEVELOPS OVER TEXAS ON FRIDAY. THE ECMWF TYPICALLY HANDLES STORM
SYSTEMS FROM THIS AREA OF THE COUNTRY BETTER THAN THE GFS. SO HAVE
LEANED TOWARD THE SLOWER ARRIVAL OF THE PRECIPITATION ON SATURDAY.
STILL WOULD NOT BE SURPRISED TO SEE THIS STORM SYSTEM EJECT
NORTHEASTWARD SLOWER THAN CURRENT THINKING.
TEMPERATURES FOR LONG TERM WE GENERALLY BE IN THE 20S FOR LOWS AND
30S FOR HIGHS.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
LOW END MVFR CEILINGS HAVE DEVELOPED OVER THE THE WESTERN 2/3RDS
OF NORTHERN OHIO EARLY THIS MORNING. EXPECT THESE MVFR CONDITIONS
TO GRADUALLY SPREAD ACROSS THE REMAINDER OF NE OHIO INTO NW PA
THROUGH LATE MORNING. ALL LOCATIONS SHOULD THEN REMAIN MVFR
THROUGH THE AFTERNOON WITH SEVERAL LOCATIONS IMPROVING ABOVE 2000
FEET. HOWEVER THE BEST CHANCES OF THIS OCCURRING WILL BE NEAR AND
WEST OF A LINE FROM KCLE TO KCAK.
WESTERLY WINDS WILL GRADUALLY BECOME SOUTHWEST AND DECREASE
THROUGH THE AFTERNOON. OVERNIGHT WINDS WILL BE LIGHT AND VARIABLE
BECOMING LIGHT SOUTHERLY. THE LIGHT WINDS SHOULD ALLOW FOR AREAS
OF FOG AND LOWERING CEILINGS. BELIEVE ALL LOCATIONS SHOULD DIP
BACK TO IFR AFTER THE 03Z TO 05Z TIME FRAME.
.OUTLOOK...NON VFR LIKELY MONDAY. AREAS OF NON VFR TUESDAY IN
RAIN SHOWERS AND ACROSS FAR NE OH/NW PA ON WEDNESDAY IN LAKE
EFFECT SNOW SHOWERS.
&&
.MARINE...
SMALL CRAFT ADVISORY WILL CONTINUE THROUGH MID MORNING. WINDS AND
WAVES SHOULD AS HIGH PRESSURE WEAKENS AND BEGINS TO SLIDE EAST. LOW
PRESSURE WILL THEN BEGIN TO MOVE INTO THE CENTRAL GREAT LAKES ON
MONDAY WITH SOUTHERLY WINDS ANTICIPATED. THE SOUTHERLY WINDS WILL
INCREASE MONDAY NIGHT BUT WILL SHIFT TO THE WEST AND NORTHWEST IN
THE WAKE OF A COLD FRONT THAT SHOULD CROSS THE LAKE TUESDAY EVENING.
WINDS WILL INCREASE WITH THE COLD ADVECTION IN THE WAKE OF THE
FRONT. AT THIS POINT IT APPEARS WINDS WILL REMAIN IN THE 15 TO 25
KNOT RANGE SO A SMALL CRAFT ADVISORY WILL BE NEED TUESDAY NIGHT INTO
AT LEAST WEDNESDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING FOR
LEZ146>149.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY/ADAMS
SHORT TERM...LOMBARDY
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1054 PM EST MON DEC 15 2014
.SYNOPSIS...
SEASONAL TEMPERATURES WILL RETURN BEHIND A COLD FRONT WHICH WILL
PASS THROUGH ON TUESDAY EVENING. SCATTERED MOUNTAIN SNOW SHOWERS
ARE THEN EXPECTED FOR MID AND LATE WEEK. CONFIDENCE IS LOW
CONCERNING ALL DETAILS AND POTENTIAL IMPACTS ASSOCIATED WITH A LOW
PRESSURE SYSTEM EXPECTED TO TRACK NORTHEAST FROM THE GULF COAST
STATES OFF THE EAST COAST THIS WEEKEND.
&&
.NEAR TERM /UNTIL 7 AM TUESDAY MORNING/...
10 PM UPDATE...
TWEAKINGS OF SKY BASED ON RECENT OBS DEPICTING A RELUCTANTLY RECEDING
REGION OF RELATIVELY HIGH RELATIVE HUMIDITY ALOFT. BUT HIGH CLOUDS
ALREADY RIDING OVER THE AREAS WHICH DID CLEAR OUT IN THE LOW
LEVELS. TEMPS DROPPED QUICKLY IN THE CLEAR AND CALM AREAS IN THE
SOUTH...SO SOME TWEAKS TO TEMPS HAVE BEEN MADE AS WELL. MOST MESO
MODELS MEANDER THE MUCH-ANTICIPATED MOISTURE/SHOWERS. SO...A
SLIGHT TWEAK LATER IN TIMING HAS ALSO BEEN MADE.
PREV...
A RIDGE OF HIGH PRESSURE WILL DRIFT OFF THE EAST COAST TONIGHT.
INCREASING SOUTH TO SOUTHWESTERLY FLOW OVER PENN /AT 925 MB AND
850 MB RESPECTIVELY/ WAS HELPING TO ERODE THE SOUTHERN EDGE OF
THE EXTENSIVE STRATUS/STRATOCU ACROSS SCENT PENN AND THE LOWER
SUSQ VALLEY REGION.
LIGHTER WINDS AND BROAD DIFFLUENCE AT BOTH LEVELS ACROSS THE
NORTHERN THIRD TO HALF OF THE STATE WILL HELP TO MAINTAIN THE
LOWER CLOUD DECK THERE THROUGH THE OVERNIGHT HOURS BENEATH CIRRUS
OF VARYING THICKNESS STREAMING NE FROM THE OHIO RIVER VALLEY.
COOLEST TEMPS TONIGHT MAY BE FOUND ACROSS THE SCENT ZONES AND
PORTIONS OF THE LOWER SUSQ VALLEY WHERE MAINLY CLEAR SKIES AND
SLIGHTLY COOLER SFC DEWPOINTS AROUND 32F WILL YIELD LATE EVENING
LOWS IN THE LOWER 30S. TEMPS WILL BE SIMILAR IF NOT A DEG OR 2
HIGHER ACRS THE NRN MTNS...WHERE CLOUDS...SLIGHTLY HIGHER
DEWPOINTS WILL BE FOUND.
THE CENTRAL MTNS AND LAURELS WILL HAVE LOWS 2-4 DEG F HIGHER THAN
ELSEWHERE ACROSS THE NORTH...AND SOUTH.
PRECIP IN THE FORM OF SHOWERS DOESN/T KNOCK ON OUR WESTERN
DOORSTEP UNTIL 10-12Z TUESDAY.
&&
.SHORT TERM /7 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
SHORT RANGE GUIDANCE REMAINS IN VERY GOOD AGREEMENT WITH BRINGING
A WEAKENING LOW PRESSURE AREA AND OCCLUSION/COLD FRONT THROUGH
THE AREA TUESDAY. MODELS DISAGREE A BIT ON PRECIP TOTALS...BUT
WITH IT ALL BEING RAIN IT WON/T MATTER TOO MUCH. AMOUNTS LOOK TO
RANGE FROM A TENTH OR TWO ACROSS THE SE TO A MAX OF MAYBE HALF AN
INCH IN THE NORTH. THOUGH IT WILL BE MILD FOR MID DECEMBER...CLOUDS
AND SHOWERS SHOULD HOLD TEMPS IN THE 40S.
MAIN PRECIP LIFTS NE TUE EVE AS MAIN TROUGH LIFTS OUT. ANOTHER
SHORTWAVE ROTATES IN FROM THE GREAT LAKES QUICKLY BEHIND...TURNING
FLOW W/NW AND PUSHING AN AREA OF SOMEWHAT COLDER AIR BACK INTO PA.
FLOW LOOKS TO ALIGN ENOUGH WITH THE LAKES TO GENERATE SOME SNOW
SHOWERS IN THE NW MTNS...WHICH WILL BRING MAINLY LIGHT
ACCUMS...THOUGH BANDS OF A COUPLE INCHES OF ACCUM IS POSS IN
PORTIONS OF MAINLY NW WARREN COUNTY. OROGRAPHIC FLOW OVER WESTERN
AND NORTHERN HIGHER TERRAIN WILL BRING LIGHT SCT SNOW SHOWERS DOWN
TO A KAOO-KUNV-KIPT LINE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
A RATHER POTENT SHORTWAVE TROUGH WILL PIVOT EASTWARD FROM THE
GREAT LAKES AND CROSS THE AREA WED NGT BEHIND THE DEPARTING
SURFACE LOW LIFTING SLOWLY NORTH FROM MAINE INTO NEW BRUNSWICK
CANADA. A REINFORCING SHOT OF COLD AIR ALOFT SHOULD ACCOMPANY THE
TRAILING SHORTWAVE WHICH MAY ACT TO BRIEFLY ENHANCE POST FRONTAL
LAKE EFFECT AND UPSLOPE SNOW SHOWERS OVER THE WESTERN HIGHLANDS.
ITS NOT OUT OF THE QUESTION THAT THE STRONG VORTMAX COULD INDUCE
SNOW SHOWERS EAST OF THE ALLEGHENY FRONT WED NGT HOWEVER THE
GLOBAL MODEL QPFS ARE NOT IN FAVOR OF THIS OUTCOME. DESPITE A
WELL ALIGNED WNW FLOW AND FAIRLY STRONG LOW LEVEL COLD AIR
ADVECTION...MODEL SOUNDINGS SHOW RATHER SHALLOW MOISTURE/LOW
INVERSION HGTS ALONG WITH DRY AIR WHICH SHOULD LIMIT MAX SNOW
ACCUM POTENTIAL (POTENTIAL FOR THIS MUCH OR WORST CASE) OVER THE
NW MTNS TO 2-3 INCHES BY THU MORNING...WITH AROUND 1 INCH ACCUM
THE MOST LIKELY OUTCOME. OVERALL THE GENERAL WEATHER TREND IN
CENTRAL PA WILL BE TOWARD A BRISK AND COLDER PATTERN WED THRU FRI.
LARGE SCALE SUBSIDENCE ASSOCIATED WITH SURFACE HIGH EXTENDING
FROM THE GREAT LAKES INTO EASTERN CANADA SHOULD BRING AN END TO
NUISANCE SNOW SHOWER ACTIVITY BY FRI NGT.
CONCERNING THE POTENTIAL WEEKEND STORM...
THERE IS BROAD MODEL CONSENSUS IN A SURFACE LOW DEVELOPING OVER
THE GULF COAST REGION AND TRACKING NORTHEAST OFF THE EAST COAST
THIS WEEKEND. HOWEVER...THERE CONTINUES TO BE A WIDE RANGE OF
POSSIBLE SOLUTIONS WITH ABOVE AVERAGE SPREAD IN THE LOW TRACK.
IN ADDITION TO THE LARGE SPREAD...THERE HAVE BEEN RUN-TO-RUN
[IN]CONSISTENCY ISSUES THAT CONTINUE TO PLAGUE THE MODEL FCSTS
IN PARTICULAR TODAYS 15/12Z RUN OF THE DETERMINISTIC ECMWF WHICH
HAS BACKED OFF ON ITS BULLISH WINTER STORM SCENARIO THAT IT HAS
BEEN ADVERTISING FOR THE PREVIOUS 4 CYCLES. CURIOUSLY BOTH THE
GEFS AND ECENS SEEM TO BE LEANING MORE IN FAVOR OF A LOW TRACK
CLOSER TO THE COAST - WITH A MEAN POSITION WEST OF THEIR
RESPSECTIVE DETERMINISTIC MODEL CORES. WITH THE STORM STILL 5-6
DAYS OUT THERE IS A LOT OF TIME FOR THE FORECAST TO CHANGE.
CONFIDENCE IS LOW REGARDING ANY POTENTIAL DETAILS OR IMPACTS WITH
THIS SYSTEM. HIGH PRESSURE SHOULD BUILD INTO THE AREA EARLY NEXT
WEEK.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
SATL IMAGERY SHOWS LOW CLOUDS HAVE CLEARED ACROSS SOUTHERN PA
EARLY THIS EVENING. THIS CLEARING TREND IS EXPECTED TO WORK SLOWLY
NORTHWARD OVERNIGHT...AS INVERSION HGT FALLS. HOWEVER...THE
CLEARING SKY...COMBINED WITH A NEARLY CALM WIND AND LOW DWPT
DEPRESSIONS...WILL LEAD TO AREAS OF FOG OVER THE EASTERN HALF OF
THE STATE. LATEST HRRR OUTPUT SUGGESTS KIPT SOUTH THRU KMDT AND
KLNS STAND THE BEST CHC OF IFR VSBYS LATE TONIGHT. INCREASING
HIGH CLOUDS AND SERLY BREEZE SHOULD LIMIT THE FOG FORMATION AT
KJST. ACROSS THE NW MTNS...MDL SOUNDINGS/SREF OUTPUT SUPPORT
LINGERING IFR CONDS AT KBFD THRU THE NIGHT.
A LOW PRESSURE SYSTEM TRACKING WEST OF PENNSYLVANIA WILL BRING A
PERIOD OF RAIN SHOWERS TUESDAY. SIGNIFICANT REDUCTIONS REMAIN
LIKELY...ESP AT KBFD WHERE MOIST SOUTHERLY FLOW ASCENDING THE MTNS
WILL LIKELY PRODUCE IFR CONDS THRU THE DAY. MAIN PRECIP WILL MOVE
OUT TUE EVE...BUT LIGHT WIND AND LINGERING LOW LVL MOISTURE COULD
RESULT IN REDUCED VSBYS FROM FOG THRU TUE EVENING.
OUTLOOK...
WED...LOW CIGS/SHSNRA LIKELY W MTNS...MAINLY AM.
THU-FRI...NO SIG WX EXPECTED.
SAT...SNOW/REDUCED VSBY POSS SOUTHERN PA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT/RXR
NEAR TERM...DANGELO/LAMBERT/RXR
SHORT TERM...
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1019 PM EST MON DEC 15 2014
.SYNOPSIS...
SEASONAL TEMPERATURES WILL RETURN BEHIND A COLD FRONT WHICH WILL
PASS THROUGH ON TUESDAY EVENING. SCATTERED MOUNTAIN SNOW SHOWERS
ARE THEN EXPECTED FOR MID AND LATE WEEK. CONFIDENCE IS LOW
CONCERNING ALL DETAILS AND POTENTIAL IMPACTS ASSOCIATED WITH A LOW
PRESSURE SYSTEM EXPECTED TO TRACK NORTHEAST FROM THE GULF COAST
STATES OFF THE EAST COAST THIS WEEKEND.
&&
.NEAR TERM /UNTIL 7 AM TUESDAY MORNING/...
10 PM UPDATE...
TWEAKINGS OF SKY BASED ON RECENT OBS DEPICTING A RELUCTANTLY RECEDING
REGION OF RELATIVELY HIGH RELATIVE HUMIDITY ALOFT. BUT HIGH CLOUDS
ALREADY RIDING OVER THE AREAS WHICH DID CLEAR OUT IN THE LOW
LEVELS. TEMPS DROPPED QUICKLY IN THE CLEAR AND CALM AREAS IN THE
SOUTH...SO SOME TWEAKS TO TEMPS HAVE BEEN MADE AS WELL. MOST MESO
MODELS MEANDER THE MUCH-ANTICIPATED MOISTURE/SHOWERS. SO...A
SLIGHT TWEAK LATER IN TIMING HAS ALSO BEEN MADE.
PREV...
A RIDGE OF HIGH PRESSURE WILL DRIFT OFF THE EAST COAST TONIGHT.
INCREASING SOUTH TO SOUTHWESTERLY FLOW OVER PENN /AT 925 MB AND
850 MB RESPECTIVELY/ WAS HELPING TO ERODE THE SOUTHERN EDGE OF
THE EXTENSIVE STRATUS/STRATOCU ACROSS SCENT PENN AND THE LOWER
SUSQ VALLEY REGION.
LIGHTER WINDS AND BROAD DIFFLUENCE AT BOTH LEVELS ACROSS THE
NORTHERN THIRD TO HALF OF THE STATE WILL HELP TO MAINTAIN THE
LOWER CLOUD DECK THERE THROUGH THE OVERNIGHT HOURS BENEATH CIRRUS
OF VARYING THICKNESS STREAMING NE FROM THE OHIO RIVER VALLEY.
COOLEST TEMPS TONIGHT MAY BE FOUND ACROSS THE SCENT ZONES AND
PORTIONS OF THE LOWER SUSQ VALLEY WHERE MAINLY CLEAR SKIES AND
SLIGHTLY COOLER SFC DEWPOINTS AROUND 32F WILL YIELD LATE EVENING
LOWS IN THE LOWER 30S. TEMPS WILL BE SIMILAR IF NOT A DEG OR 2
HIGHER ACRS THE NRN MTNS...WHERE CLOUDS...SLIGHTLY HIGHER
DEWPOINTS WILL BE FOUND.
THE CENTRAL MTNS AND LAURELS WILL HAVE LOWS 2-4 DEG F HIGHER THAN
ELSEWHERE ACROSS THE NORTH...AND SOUTH.
PRECIP IN THE FORM OF SHOWERS DOESN/T KNOCK ON OUR WESTERN
DOORSTEP UNTIL 10-12Z TUESDAY.
&&
.SHORT TERM /7 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
SHORT RANGE GUIDANCE REMAINS IN VERY GOOD AGREEMENT WITH BRINGING
A WEAKENING LOW PRESSURE AREA AND OCCLUSION/COLD FRONT THROUGH
THE AREA TUESDAY. MODELS DISAGREE A BIT ON PRECIP TOTALS...BUT
WITH IT ALL BEING RAIN IT WON/T MATTER TOO MUCH. AMOUNTS LOOK TO
RANGE FROM A TENTH OR TWO ACROSS THE SE TO A MAX OF MAYBE HALF AN
INCH IN THE NORTH. THOUGH IT WILL BE MILD FOR MID DECEMBER...CLOUDS
AND SHOWERS SHOULD HOLD TEMPS IN THE 40S.
MAIN PRECIP LIFTS NE TUE EVE AS MAIN TROUGH LIFTS OUT. ANOTHER
SHORTWAVE ROTATES IN FROM THE GREAT LAKES QUICKLY BEHIND...TURNING
FLOW W/NW AND PUSHING AN AREA OF SOMEWHAT COLDER AIR BACK INTO PA.
FLOW LOOKS TO ALIGN ENOUGH WITH THE LAKES TO GENERATE SOME SNOW
SHOWERS IN THE NW MTNS...WHICH WILL BRING MAINLY LIGHT
ACCUMS...THOUGH BANDS OF A COUPLE INCHES OF ACCUM IS POSS IN
PORTIONS OF MAINLY NW WARREN COUNTY. OROGRAPHIC FLOW OVER WESTERN
AND NORTHERN HIGHER TERRAIN WILL BRING LIGHT SCT SNOW SHOWERS DOWN
TO A KAOO-KUNV-KIPT LINE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
A RATHER POTENT SHORTWAVE TROUGH WILL PIVOT EASTWARD FROM THE
GREAT LAKES AND CROSS THE AREA WED NGT BEHIND THE DEPARTING
SURFACE LOW LIFTING SLOWLY NORTH FROM MAINE INTO NEW BRUNSWICK
CANADA. A REINFORCING SHOT OF COLD AIR ALOFT SHOULD ACCOMPANY THE
TRAILING SHORTWAVE WHICH MAY ACT TO BRIEFLY ENHANCE POST FRONTAL
LAKE EFFECT AND UPSLOPE SNOW SHOWERS OVER THE WESTERN HIGHLANDS.
ITS NOT OUT OF THE QUESTION THAT THE STRONG VORTMAX COULD INDUCE
SNOW SHOWERS EAST OF THE ALLEGHENY FRONT WED NGT HOWEVER THE
GLOBAL MODEL QPFS ARE NOT IN FAVOR OF THIS OUTCOME. DESPITE A
WELL ALIGNED WNW FLOW AND FAIRLY STRONG LOW LEVEL COLD AIR
ADVECTION...MODEL SOUNDINGS SHOW RATHER SHALLOW MOISTURE/LOW
INVERSION HGTS ALONG WITH DRY AIR WHICH SHOULD LIMIT MAX SNOW
ACCUM POTENTIAL (POTENTIAL FOR THIS MUCH OR WORST CASE) OVER THE
NW MTNS TO 2-3 INCHES BY THU MORNING...WITH AROUND 1 INCH ACCUM
THE MOST LIKELY OUTCOME. OVERALL THE GENERAL WEATHER TREND IN
CENTRAL PA WILL BE TOWARD A BRISK AND COLDER PATTERN WED THRU FRI.
LARGE SCALE SUBSIDENCE ASSOCIATED WITH SURFACE HIGH EXTENDING
FROM THE GREAT LAKES INTO EASTERN CANADA SHOULD BRING AN END TO
NUISANCE SNOW SHOWER ACTIVITY BY FRI NGT.
CONCERNING THE POTENTIAL WEEKEND STORM...
THERE IS BROAD MODEL CONSENSUS IN A SURFACE LOW DEVELOPING OVER
THE GULF COAST REGION AND TRACKING NORTHEAST OFF THE EAST COAST
THIS WEEKEND. HOWEVER...THERE CONTINUES TO BE A WIDE RANGE OF
POSSIBLE SOLUTIONS WITH ABOVE AVERAGE SPREAD IN THE LOW TRACK.
IN ADDITION TO THE LARGE SPREAD...THERE HAVE BEEN RUN-TO-RUN
[IN]CONSISTENCY ISSUES THAT CONTINUE TO PLAGUE THE MODEL FCSTS
IN PARTICULAR TODAYS 15/12Z RUN OF THE DETERMINISTIC ECMWF WHICH
HAS BACKED OFF ON ITS BULLISH WINTER STORM SCENARIO THAT IT HAS
BEEN ADVERTISING FOR THE PREVIOUS 4 CYCLES. CURIOUSLY BOTH THE
GEFS AND ECENS SEEM TO BE LEANING MORE IN FAVOR OF A LOW TRACK
CLOSER TO THE COAST - WITH A MEAN POSITION WEST OF THEIR
RESPSECTIVE DETERMINISTIC MODEL CORES. WITH THE STORM STILL 5-6
DAYS OUT THERE IS A LOT OF TIME FOR THE FORECAST TO CHANGE.
CONFIDENCE IS LOW REGARDING ANY POTENTIAL DETAILS OR IMPACTS WITH
THIS SYSTEM. HIGH PRESSURE SHOULD BUILD INTO THE AREA EARLY NEXT
WEEK.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
SATL IMAGERY SHOWS LOW CLOUDS HAVE CLEARED ACROSS SOUTHERN PA
EARLY THIS EVENING. THIS CLEARING TREND IS EXPECTED TO WORK SLOWLY
NORTHWARD OVERNIGHT...AS INVERSION HGT FALLS. HOWEVER...THE
CLEARING SKY...COMBINED WITH A NEARLY CALM WIND AND LOW DWPT
DEPRESSIONS...WILL LEAD TO AREAS OF FOG OVER THE EASTERN HALF OF
THE STATE. LATEST HRRR OUTPUT SUGGESTS KIPT SOUTH THRU KMDT AND
KLNS STAND THE BEST CHC OF IFR VSBYS LATE TONIGHT. INCREASING
HIGH CLOUDS AND SERLY BREEZE SHOULD LIMIT THE FOG FORMATION AT
KJST. ACROSS THE NW MTNS...MDL SOUNDINGS/SREF OUTPUT SUPPORT
LINGERING IFR CIGS AT KBFD THRU THE NIGHT.
A LOW PRESSURE SYSTEM TRACKING WEST OF PENNSYLVANIA WILL BRING A
PERIOD OF RAIN SHOWERS TUESDAY. REDUCTIONS REMAIN LIKELY...ESP AT
KBFD WHERE MOIST SOUTHERLY FLOW ASCENDING THE MTNS WILL LIKELY
PRODUCE IFR CONDS THRU THE DAY. MAIN PRECIP WILL MOVE OUT TUE
EVE...BUT LIGHT WIND AND LINGERING LOW LVL MOISTURE COULD RESULT
IN REDUCED VSBYS FROM FOG THRU TUE EVENING.
OUTLOOK...
WED...LOW CIGS/SHSNRA LIKELY W MTNS...MAINLY AM.
THU-FRI...NO SIG WX EXPECTED.
SAT...SNOW/REDUCED VSBY POSS SOUTHERN PA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT/RXR
NEAR TERM...DANGELO/LAMBERT/RXR
SHORT TERM...
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
815 PM EST MON DEC 15 2014
.SYNOPSIS...
ABOVE NORMAL TEMPERATURES WILL CONTINUE INTO TUESDAY BEFORE MORE
SEASONAL TEMPERATURES RETURN BEHIND A COLD FRONT. A LOW PRESSURE
SYSTEM WILL BRING RAIN SHOWERS TO CENTRAL PENNSYLVANIA ON
TUESDAY...FOLLOWED BY A COLD FRONT TUESDAY EVENING BRINGING A
RETURN OF SCATTERED MOUNTAIN SNOW SHOWERS FOR MID AND LATE WEEK.
CONFIDENCE IS LOW CONCERNING ALL DETAILS AND POTENTIAL IMPACTS
ASSOCIATED WITH A LOW PRESSURE SYSTEM EXPECTED TO TRACK NORTHEAST
FROM THE GULF COAST STATES OFF THE EAST COAST THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
A RIDGE OF HIGH PRESSURE WILL DRIFT OFF THE EAST COAST TONIGHT.
INCREASING SOUTH TO SOUTHWESTERLY FLOW OVER PENN /AT 925 MB AND
850 MB RESPECTIVELY/ WAS HELPING TO ERODE THE SOUTHERN EDGE OF
THE EXTENSIVE STRATUS/STRATOCU ACROSS SCENT PENN AND THE LOWER
SUSQ VALLEY REGION.
LIGHTER WINDS AND BROAD DIFFLUENCE AT BOTH LEVELS ACROSS THE
NORTHERN THIRD TO HALF OF THE STATE WILL HELP TO MAINTAIN THE
LOWER CLOUD DECK THERE THROUGH THE OVERNIGHT HOURS BENEATH CIRRUS
OF VARYING THICKNESS STREAMING NE FROM THE OHIO RIVER VALLEY.
COOLEST TEMPS TONIGHT MAY BE FOUND ACROSS THE SCENT ZONES AND
PORTIONS OF THE LOWER SUSQ VALLEY WHERE MAINLY CLEAR SKIES AND
SLIGHTLY COOLER SFC DEWPOINTS AROUND 32F WILL YIELD LATE EVENING
LOWS IN THE LOWER 30S. TEMPS WILL BE SIMILAR IF NOT A DEG OR 2
HIGHER ACRS THE NRN MTNS...WHERE CLOUDS...SLIGHTLY HIGHER
DEWPOINTS WILL BE FOUND.
THE CENTRAL MTNS AND LAURELS WILL HAVE LOWS 2-4 DEG F HIGHER THAN
ELSEWHERE ACROSS THE NORTH...AND SOUTH.
PRECIP IN THE FORM OF SHOWERS DOESN/T KNOCK ON OUR WESTERN
DOORSTEP UNTIL 10-12Z TUESDAY.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
SHORT RANGE GUIDANCE REMAINS IN VERY GOOD AGREEMENT WITH BRINGING
A WEAKENING LOW PRESSURE AREA AND OCCLUSION/COLD FRONT THROUGH
THE AREA TUESDAY. MODELS DISAGREE A BIT ON PRECIP TOTALS...BUT
WITH IT ALL BEING RAIN IT WON/T MATTER TOO MUCH. AMOUNTS LOOK TO
RANGE FROM A TENTH OR TWO ACROSS THE SE TO A MAX OF MAYBE HALF AN
INCH IN THE NORTH. THOUGH IT WILL BE MILD FOR MID DECEMBER...CLOUDS
AND SHOWERS SHOULD HOLD TEMPS IN THE 40S.
MAIN PRECIP LIFTS NE TUE EVE AS MAIN TROUGH LIFTS OUT. ANOTHER
SHORTWAVE ROTATES IN FROM THE GREAT LAKES QUICKLY BEHIND...TURNING
FLOW W/NW AND PUSHING AN AREA OF SOMEWHAT COLDER AIR BACK INTO PA.
FLOW LOOKS TO ALIGN ENOUGH WITH THE LAKES TO GENERATE SOME SNOW
SHOWERS IN THE NW MTNS...WHICH WILL BRING MAINLY LIGHT
ACCUMS...THOUGH BANDS OF A COUPLE INCHES OF ACCUM IS POSS IN
PORTIONS OF MAINLY NW WARREN COUNTY. OROGRAPHIC FLOW OVER WESTERN
AND NORTHERN HIGHER TERRAIN WILL BRING LIGHT SCT SNOW SHOWERS DOWN
TO A KAOO-KUNV-KIPT LINE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
A RATHER POTENT SHORTWAVE TROUGH WILL PIVOT EASTWARD FROM THE
GREAT LAKES AND CROSS THE AREA WED NGT BEHIND THE DEPARTING
SURFACE LOW LIFTING SLOWLY NORTH FROM MAINE INTO NEW BRUNSWICK
CANADA. A REINFORCING SHOT OF COLD AIR ALOFT SHOULD ACCOMPANY THE
TRAILING SHORTWAVE WHICH MAY ACT TO BRIEFLY ENHANCE POST FRONTAL
LAKE EFFECT AND UPSLOPE SNOW SHOWERS OVER THE WESTERN HIGHLANDS.
ITS NOT OUT OF THE QUESTION THAT THE STRONG VORTMAX COULD INDUCE
SNOW SHOWERS EAST OF THE ALLEGHENY FRONT WED NGT HOWEVER THE
GLOBAL MODEL QPFS ARE NOT IN FAVOR OF THIS OUTCOME. DESPITE A
WELL ALIGNED WNW FLOW AND FAIRLY STRONG LOW LEVEL COLD AIR
ADVECTION...MODEL SOUNDINGS SHOW RATHER SHALLOW MOISTURE/LOW
INVERSION HGTS ALONG WITH DRY AIR WHICH SHOULD LIMIT MAX SNOW
ACCUM POTENTIAL (POTENTIAL FOR THIS MUCH OR WORST CASE) OVER THE
NW MTNS TO 2-3 INCHES BY THU MORNING...WITH AROUND 1 INCH ACCUM
THE MOST LIKELY OUTCOME. OVERALL THE GENERAL WEATHER TREND IN
CENTRAL PA WILL BE TOWARD A BRISK AND COLDER PATTERN WED THRU FRI.
LARGE SCALE SUBSIDENCE ASSOCIATED WITH SURFACE HIGH EXTENDING
FROM THE GREAT LAKES INTO EASTERN CANADA SHOULD BRING AN END TO
NUISANCE SNOW SHOWER ACTIVITY BY FRI NGT.
CONCERNING THE POTENTIAL WEEKEND STORM...
THERE IS BROAD MODEL CONSENSUS IN A SURFACE LOW DEVELOPING OVER
THE GULF COAST REGION AND TRACKING NORTHEAST OFF THE EAST COAST
THIS WEEKEND. HOWEVER...THERE CONTINUES TO BE A WIDE RANGE OF
POSSIBLE SOLUTIONS WITH ABOVE AVERAGE SPREAD IN THE LOW TRACK.
IN ADDITION TO THE LARGE SPREAD...THERE HAVE BEEN RUN-TO-RUN
[IN]CONSISTENCY ISSUES THAT CONTINUE TO PLAGUE THE MODEL FCSTS
IN PARTICULAR TODAYS 15/12Z RUN OF THE DETERMINISTIC ECMWF WHICH
HAS BACKED OFF ON ITS BULLISH WINTER STORM SCENARIO THAT IT HAS
BEEN ADVERTISING FOR THE PREVIOUS 4 CYCLES. CURIOUSLY BOTH THE
GEFS AND ECENS SEEM TO BE LEANING MORE IN FAVOR OF A LOW TRACK
CLOSER TO THE COAST - WITH A MEAN POSITION WEST OF THEIR
RESPSECTIVE DETERMINISTIC MODEL CORES. WITH THE STORM STILL 5-6
DAYS OUT THERE IS A LOT OF TIME FOR THE FORECAST TO CHANGE.
CONFIDENCE IS LOW REGARDING ANY POTENTIAL DETAILS OR IMPACTS WITH
THIS SYSTEM. HIGH PRESSURE SHOULD BUILD INTO THE AREA EARLY NEXT
WEEK.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
SATL IMAGERY SHOWS LOW CLOUDS HAVE CLEARED ACROSS SOUTHERN PA
EARLY THIS EVENING. THIS CLEARING TREND IS EXPECTED TO WORK SLOWLY
NORTHWARD OVERNIGHT...AS INVERSION HGT FALLS. HOWEVER...THE
CLEARING SKY...COMBINED WITH A NEARLY CALM WIND AND LOW DWPT
DEPRESSIONS...WILL LEAD TO AREAS OF FOG OVER THE EASTERN HALF OF
THE STATE. LATEST HRRR OUTPUT SUGGESTS KIPT SOUTH THRU KMDT AND
KLNS STAND THE BEST CHC OF IFR VSBYS LATE TONIGHT. INCREASING
HIGH CLOUDS AND SERLY BREEZE SHOULD LIMIT THE FOG FORMATION AT
KJST. ACROSS THE NW MTNS...MDL SOUNDINGS/SREF OUTPUT SUPPORT
LINGERING IFR CIGS AT KBFD THRU THE NIGHT.
A LOW PRESSURE SYSTEM TRACKING WEST OF PENNSYLVANIA WILL BRING A
PERIOD OF RAIN SHOWERS TUESDAY. REDUCTIONS REMAIN LIKELY...ESP AT
KBFD WHERE MOIST SOUTHERLY FLOW ASCENDING THE MTNS WILL LIKELY
PRODUCE IFR CONDS THRU THE DAY. MAIN PRECIP WILL MOVE OUT TUE
EVE...BUT LIGHT WIND AND LINGERING LOW LVL MOISTURE COULD RESULT
IN REDUCED VSBYS FROM FOG THRU TUE EVENING.
OUTLOOK...
WED...LOW CIGS/SHSNRA LIKELY W MTNS...MAINLY AM.
THU-FRI...NO SIG WX EXPECTED.
SAT...SNOW/REDUCED VSBY POSS SOUTHERN PA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT/RXR
NEAR TERM...LAMBERT/RXR
SHORT TERM...RXR
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
718 PM EST MON DEC 15 2014
.SYNOPSIS...
ABOVE NORMAL TEMPERATURES WILL CONTINUE INTO TUESDAY BEFORE MORE
SEASONAL TEMPERATURES RETURN BEHIND A COLD FRONT. A LOW PRESSURE
SYSTEM WILL BRING RAIN SHOWERS TO CENTRAL PENNSYLVANIA ON
TUESDAY...FOLLOWED BY A COLD FRONT TUESDAY EVENING BRINGING A
RETURN OF SCATTERED MOUNTAIN SNOW SHOWERS FOR MID AND LATE WEEK.
CONFIDENCE IS LOW CONCERNING ALL DETAILS AND POTENTIAL IMPACTS
ASSOCIATED WITH A LOW PRESSURE SYSTEM EXPECTED TO TRACK NORTHEAST
FROM THE GULF COAST STATES OFF THE EAST COAST THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
ERODING CLOUD COVER ACROSS THE SOUTHERN TIER AS DEVELOPING
SOUTHERLY FLOW HAS BROUGHT SOME SUNSHINE AND WARMER TEMPS THAT
HAVE CLIMBED SOLIDLY INTO THE UPPER 40S TO MID 50S ALONG THE MD
BORDER. THOUGH THE REMAINDER OF THE STRATUS SHIELD HAS
THINNED A BIT...IT REMAINS STUBBORN ENOUGH TO KEEP CLOUDS IN
PLACE HOLDING TEMPS IN THE UPPER 30S TO MID 40S.
HIGH PRESSURE WILL CEDE OVERNIGHT TO INCREASING SOUTHERLY FLOW
AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM. SHOULD SEE STRATOCU
MIX OUT DURING THE OVERNIGHT HOURS AS WINDS INCREASE...BUT THESE
WILL BE REPLACED BY MID/HIGH CLOUDS STREAKING IN AHEAD OF
APPROACHING SYSTEM. PRECIP WILL SLIP INTO THE OHIO VALLEY
THIS EVENING AND APPROACH MY WESTERN BORDER BY 10-14Z. TEMPS LOOK
TO REMAIN ABOVE FREEZING IN WAA SO PRECIP TYPE WILL BE RAIN.
NAM/GFS HINT AT A BIT OF DRIZZLE DEVELOPING OUT AHEAD OF THIS
SYSTEM THOUGH...AND IF THIS COMES TO FRUITION LATE THIS EVENING IT
COULD POTENTIALLY BRING VERY LIGHT AMOUNTS OF FREEZING PRECIP TO
PORTIONS OF NORTHERN MTNS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
SHORT RANGE GUIDANCE REMAINS IN VERY GOOD AGREEMENT WITH BRINGING
A WEAKENING LOW PRESSURE AREA AND OCCLUSION/COLD FRONT THROUGH
THE AREA TUESDAY. MODELS DISAGREE A BIT ON PRECIP TOTALS...BUT
WITH IT ALL BEING RAIN IT WON/T MATTER TOO MUCH. AMOUNTS LOOK TO
RANGE FROM A TENTH OR TWO ACROSS THE SE TO A MAX OF MAYBE HALF AN
INCH IN THE NORTH. THOUGH IT WILL BE MILD FOR MID DECEMBER...CLOUDS
AND SHOWERS SHOULD HOLD TEMPS IN THE 40S.
MAIN PRECIP LIFTS NE TUE EVE AS MAIN TROUGH LIFTS OUT. ANOTHER
SHORTWAVE ROTATES IN FROM THE GREAT LAKES QUICKLY BEHIND...TURNING
FLOW W/NW AND PUSHING AN AREA OF SOMEWHAT COLDER AIR BACK INTO PA.
FLOW LOOKS TO ALIGN ENOUGH WITH THE LAKES TO GENERATE SOME SNOW
SHOWERS IN THE NW MTNS...WHICH WILL BRING MAINLY LIGHT
ACCUMS...THOUGH BANDS OF A COUPLE INCHES OF ACCUM IS POSS IN
PORTIONS OF MAINLY NW WARREN COUNTY. OROGRAPHIC FLOW OVER WESTERN
AND NORTHERN HIGHER TERRAIN WILL BRING LIGHT SCT SNOW SHOWERS DOWN
TO A KAOO-KUNV-KIPT LINE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
A RATHER POTENT SHORTWAVE TROUGH WILL PIVOT EASTWARD FROM THE
GREAT LAKES AND CROSS THE AREA WED NGT BEHIND THE DEPARTING
SURFACE LOW LIFTING SLOWLY NORTH FROM MAINE INTO NEW BRUNSWICK
CANADA. A REINFORCING SHOT OF COLD AIR ALOFT SHOULD ACCOMPANY THE
TRAILING SHORTWAVE WHICH MAY ACT TO BRIEFLY ENHANCE POST FRONTAL
LAKE EFFECT AND UPSLOPE SNOW SHOWERS OVER THE WESTERN HIGHLANDS.
ITS NOT OUT OF THE QUESTION THAT THE STRONG VORTMAX COULD INDUCE
SNOW SHOWERS EAST OF THE ALLEGHENY FRONT WED NGT HOWEVER THE
GLOBAL MODEL QPFS ARE NOT IN FAVOR OF THIS OUTCOME. DESPITE A
WELL ALIGNED WNW FLOW AND FAIRLY STRONG LOW LEVEL COLD AIR
ADVECTION...MODEL SOUNDINGS SHOW RATHER SHALLOW MOISTURE/LOW
INVERSION HGTS ALONG WITH DRY AIR WHICH SHOULD LIMIT MAX SNOW
ACCUM POTENTIAL (POTENTIAL FOR THIS MUCH OR WORST CASE) OVER THE
NW MTNS TO 2-3 INCHES BY THU MORNING...WITH AROUND 1 INCH ACCUM
THE MOST LIKELY OUTCOME. OVERALL THE GENERAL WEATHER TREND IN
CENTRAL PA WILL BE TOWARD A BRISK AND COLDER PATTERN WED THRU FRI.
LARGE SCALE SUBSIDENCE ASSOCIATED WITH SURFACE HIGH EXTENDING
FROM THE GREAT LAKES INTO EASTERN CANADA SHOULD BRING AN END TO
NUISANCE SNOW SHOWER ACTIVITY BY FRI NGT.
CONCERNING THE POTENTIAL WEEKEND STORM...
THERE IS BROAD MODEL CONSENSUS IN A SURFACE LOW DEVELOPING OVER
THE GULF COAST REGION AND TRACKING NORTHEAST OFF THE EAST COAST
THIS WEEKEND. HOWEVER...THERE CONTINUES TO BE A WIDE RANGE OF
POSSIBLE SOLUTIONS WITH ABOVE AVERAGE SPREAD IN THE LOW TRACK.
IN ADDITION TO THE LARGE SPREAD...THERE HAVE BEEN RUN-TO-RUN
[IN]CONSISTENCY ISSUES THAT CONTINUE TO PLAGUE THE MODEL FCSTS
IN PARTICULAR TODAYS 15/12Z RUN OF THE DETERMINISTIC ECMWF WHICH
HAS BACKED OFF ON ITS BULLISH WINTER STORM SCENARIO THAT IT HAS
BEEN ADVERTISING FOR THE PREVIOUS 4 CYCLES. CURIOUSLY BOTH THE
GEFS AND ECENS SEEM TO BE LEANING MORE IN FAVOR OF A LOW TRACK
CLOSER TO THE COAST - WITH A MEAN POSITION WEST OF THEIR
RESPSECTIVE DETERMINISTIC MODEL CORES. WITH THE STORM STILL 5-6
DAYS OUT THERE IS A LOT OF TIME FOR THE FORECAST TO CHANGE.
CONFIDENCE IS LOW REGARDING ANY POTENTIAL DETAILS OR IMPACTS WITH
THIS SYSTEM. HIGH PRESSURE SHOULD BUILD INTO THE AREA EARLY NEXT
WEEK.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
SATL IMAGERY SHOWS LOW CLOUDS HAVE CLEARED ACROSS SOUTHERN PA
EARLY THIS EVENING. THIS CLEARING TREND IS EXPECTED TO WORK SLOWLY
NORTHWARD OVERNIGHT...AS INVERSION HGT FALLS. HOWEVER...THE
CLEARING SKY...COMBINED WITH A NEARLY CALM WIND AND LOW DWPT
DEPRESSIONS...WILL LEAD TO AREAS OF FOG OVER THE EASTERN HALF OF
THE STATE. LATEST HRRR OUTPUT SUGGESTS KIPT SOUTH THRU KMDT AND
KLNS STAND THE BEST CHC OF IFR VSBYS LATE TONIGHT. INCREASING
HIGH CLOUDS AND SERLY BREEZE SHOULD LIMIT THE FOG FORMATION AT
KJST. ACROSS THE NW MTNS...MDL SOUNDINGS/SREF OUTPUT SUPPORT
LINGERING IFR CIGS AT KBFD THRU THE NIGHT.
A LOW PRESSURE SYSTEM TRACKING WEST OF PENNSYLVANIA WILL BRING A
PERIOD OF RAIN SHOWERS TUESDAY. REDUCTIONS REMAIN LIKELY...ESP AT
KBFD WHERE MOIST SOUTHERLY FLOW ASCENDING THE MTNS WILL LIKELY
PRODUCE IFR CONDS THRU THE DAY. MAIN PRECIP WILL MOVE OUT TUE
EVE...BUT LIGHT WIND AND LINGERING LOW LVL MOISTURE COULD RESULT
IN REDUCED VSBYS FROM FOG THRU TUE EVENING.
OUTLOOK...
WED...LOW CIGS/SHSNRA LIKELY W MTNS...MAINLY AM.
THU-FRI...NO SIG WX EXPECTED.
SAT...SNOW/REDUCED VSBY POSS SOUTHERN PA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RXR
NEAR TERM...RXR
SHORT TERM...
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
435 PM MST MON DEC 15 2014
.SHORT TERM...THIS EVENING THROUGH TUESDAY NIGHT
ISSUED AT 213 PM MST MON DEC 15 2014
UPPER LEVEL ANALYSIS HAS LOW CENTER OVER IOWA SLIDING NORTHEAST.
UPPER RIDGE IS SLOWLY BUILDING ACROSS THE ROCKIES AS EAST PACIFIC
TROF APPROACHES THE WEST COAST. SKIES ACROSS THE NORTHERN PLAINS
RANGE FROM MOSTLY SUNNY OVER WESTERN AREAS...TO CLOUDY WITH LIGHT
SNOW FROM THE CENTRAL DAKOTAS EAST. AT THE SURFACE...CANADIAN
HIGH PRESSURE CONTINUES TO SLIDE SOUTH INTO THE AREA. NORTHWEST
WINDS CONTINUE TO BE QUITE BREEZY...WITH WINDS JUST BEGINNING TO
SLACKEN ACROSS NORTHEAST WYOMING. TEMPERATURES AT 2 PM ARE IN THE
20S.
TONIGHT...DRY AIR MOVES IN QUICKLY TONIGHT BEHIND THE EXITING
SYSTEM...AND PRECIP WILL END ACROSS SOUTH CENTRAL SOUTH DAKOTA BY
EARLY EVENING. HOWEVER...SOME AREAS OF CLOUDS AND SOME PATCHY FOG
WILL STICK AROUND THROUGH THE NIGHT. WITH MAINLY PARTLY CLOUDY
CONDITIONS OVERNIGHT...LOW TEMPERATURES WILL FALL INTO THE SINGLE
DIGITS AND TEENS.
TUESDAY...WESTERN UPPER RIDGE WILL CROSS THE NORTHERN PLAINS AS
THE CANADIAN SURFACE HIGH SHIFTS INTO THE EASTERN DAKOTAS. NORTH
WINDS WILL BE LIGHT...AND SLOWLY SHIFT AROUND OUT OF THE SOUTH BY
LATE AFTERNOON. HIGHS WILL BE IN THE 20S TO LOWER 30S...WITH LOWS
TUESDAY NIGHT AROUND 10 TO 20. SKIES WILL BECOME CLOUDIER
OVERNIGHT AHEAD OF AN APPROACHING UPPER TROUGH.
.LONG TERM...WEDNESDAY THROUGH MONDAY
ISSUED AT 213 PM MST MON DEC 15 2014
PROGRESSIVE SPLIT FLOW PATTERN TO PERSIST THROUGH THE LONG TERM
PERIOD. MAINLY DRY WX EXPECTED THROUGH THE PERIOD GIVEN TROUGH RE-
LOADING IN THE WESTERN CONUS. HOWEVER...ANOTHER STRONG SOUTHERN
PERIPHERY UPPER TROUGH WILL EJECT OUT OF THE SW CONUS IN THE THU-
FRI PERIOD. FORECAST MODELS ARE NOW LATCHING ONTO THE EJECTION OF
A PRIMARY FRONT SIDE IMPULSE. THIS SYSTEM WOULD BRING A SMALL
CHANCE FOR LIGHT SNOW ACROSS THE FAR NW FA WED AS IT INTERACTS
WITH THE LL BAROCLINIC ZONE IN PLACE. THIS SYSTEM IS PRESENT IN
ALL FORECAST MODELS ALTHOUGH THE TRACK IS STILL IN QUESTION.
INCLUDED A LOW POP ACROSS THE NW WED FOR THIS. THE MAIN SW CONUS
UPPER TROUGH CONTINUES TO BE ADVERTISED TO TRACK JUST SOUTH OF THE
FA TOWARD THE END OF THE WEEK. IF ANY NORTHERN STREAM IMPULSES
TEND TO PHASE WITH THIS SYSTEM...A TRACK FARTHER NW COULD STILL BE
POSSIBLE...WHICH COULD BRING SOME CHANCES FOR SNOW TO SCENTRAL
AREAS ONCE AGAIN TOWARD FRIDAY-SAT. TENDENCIES FOR ANOTHER STRONG
WESTERN NOAM RIDGE REMAIN PRESENT IN MEAN ENSEMBLES AND
DETERMINISTIC SOLUTIONS PER ANOTHER EXTENSION OF THE EAST ASIAN
UPPER JET. THIS COULD SPELL MUCH WARMER CONDITIONS FOR THE
FOLLOWING WEEK IF THE RIDGE BIASES EAST AS IT HAS IN THIS PATTERN.
HOWEVER...CURRENT LONG RANGE ECMWF/GFS RUNS STILL SUPPORT A CLOSED
LOW IN THE PACIFIC NEAR HAWAII WITH A DOMINATE NORTHERN
STREAM...UNCHARACTERISTIC OF THE CURRENT REGIME. THE 12Z ECMWF HAS
NOW SHIFTED THE RIDGE SLIGHTLY NE WITH THE BAROCLINIC ZONE RIGHT
ON TOP OF THE FA. THIS HEIGHT PATTERN LOOKS VERY SIMILAR TO THE
THANKSGIVING DAY PATTERN 7-10 DAYS OUT WITH A LARGE RANGE IN TEMPS
AMONG DETERMINISTIC SOLUTIONS MID NEXT WEEK.
GIVEN STRONGER PROGRESSIVE TENDENCIES...FORECAST MODELS SUPPORT
WARMER WESTERLY FLOW INTO THE REGION A LITTLE EARLIER THAN BEFORE.
HENCE...HAVE WARMED TEMPS SOME IN THE LATTER PORTION OF THE PERIOD.
OTHERWISE...NO OTHER SIG CHANGES TO THE FORECAST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 426 PM MST MON DEC 15 2014
UPPER LOW AND ASSOCIATED SNOWS WILL END ACROSS THE AREA THIS
EVENING. IFR CIGS ON THE SD PLAINS WILL TREND TO MVFR AND LIKELY
REMAIN THROUGH MUCH OF THE PERIOD. FURTHER WEST...CLEAR SKIES
WILL LIKELY REMAIN OVER THE BLACK HILLS AND ADJACENT PLAINS.
HOWEVER...MVFR CIGS ARE EXPECTED TO STRADDLE THE RAP
TERMINAL GIVEN MOIST NW FLOW...CONFIRMED IN HIRES GUIDANCE. THERE
IS THE POTENTIAL FOR CLEARING AT THE RAP TERMINAL.
HOWEVER...HIGHEST CONFIDENCE IS IN CONTINUED MVFR CIGS. LOW CIGS
OVER THE WY PLAINS MAY LINGER INTO LATE TUE MORNING UNTIL DRY LL
SW FLOW CAN BECOME ESTABLISHED. RAP MODEL INDICATES POTENTIAL
CLEARING EARLIER...HOWEVER CONFIDENCE IN THIS REMAINS LOW GIVEN
HIRES GUIDANCE. WILL KEEP WITH IFR CIGS ATTM MONITORING TRENDS FOR
POTENTIAL AMENDMENTS. CIGS WILL BE DIFFICULT LATE IN THE PERIOD
TUE AFTERNOON AS THE SFC RIDGE AXIS WILL BE OVER THE FA. THIS WILL
LIKELY HINDER STRATUS MIX OUT WITH MANY PLACES LIKELY SEEING MVFR
CIGS.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR SDZ046-
047-049.
WY...NONE.
&&
$$
SHORT TERM...15
LONG TERM...JC
AVIATION...JC
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
328 AM EST SUN DEC 14 2014
.SHORT TERM (TODAY AND TONIGHT)...MAIN CONCERNS ARE EXTENT OF LOW-
CLOUDS AND PATCHY FREEZING DENSE FOG FOR THIS MORNING. HRRR MODEL
SEEMS TO PERFORM THE BEST DURING THE PAST 24 HOURS AND WILL FOLLOW
CLOSELY FOR FORECASTING LOW-CLOUDS. CLOUD COVER WILL MAINLY BE
CONFINED ACROSS THE NORTHERN AND WESTERN COUNTIES THROUGH THE
FORECAST...EXCEPT FOR FOG DEVELOPMENT.
CLOSE DEWPOINT DEPRESSIONS...CLEAR SKY CALM WINDS HAVE ALLOWED
PATCHY DENSE FOG TO DEVELOP THIS MORNING. FOG AND TEMPERATURES
BELOW FREEZING WILL PRODUCE A GOOD DEAL OF FROST DEVELOPMENT.
FOG WILL DISSIPATE BY MID-MORNING...BUT LOW CLOUDS REMAIN...
MAINLY OVER SOUTHWEST VIRGINIA AND THE PLATEAU COUNTIES.
FOR TONIGHT...ANOTHER ROUND OF FOG DEVELOPMENT ANTICIPATED.
.LONG TERM /MONDAY THROUGH SATURDAY/... WINDS WILL VEER TO THE
SOUTHWEST AHEAD OF AN APPROACHING COLD FRONT. THESE WINDS...ALONG
WITH MOSTLY TO PARTLY SUNNY CONDITIONS WILL ALLOW FOR AN EVEN WARMER
DAY ONCE ANY LINGERING OVERNIGHT FOG/CLOUD COVER DISSIPATES...WITH
HIGHS IN THE 55 TO 60 DEGREE RANGE IN MOST LOCATIONS. AS THE FRONT
SLOWLY MOVES INTO THE AREA...CLOUDS WILL INCREASE AND SCATTERED
SHOWERS WILL OVERSPREAD THE REGION OVER THE COURSE OF THE NIGHT AND
INTO THE MORNING HOURS ON TUESDAY....BEFORE TAPERING OFF BY MIDDAY.
HOWEVER...SOME WRAP AROUND MOISTURE AND A PERSISTENT INVERSION MAY
KEEP LOW CLOUDS IN /PARTICULARLY ACROSS THE NORTHERN HALF OF THE
AREA/ THROUGH THE DAY ON TUESDAY AND EVEN INTO WEDNESDAY. AFTER A
BRIEF BOUT OF RIDGING ON THURSDAY...ANOTHER BROAD UPPER-TROUGH WILL
SWING FROM THE LOWER-MISSISSIPPI VALLEY INTO THE AREA LATE FRIDAY
INTO SATURDAY...BRINGING SOME DECENT CHANCES FOR PRECIPITATION AND
SOME COOLER TEMPERATURES HEADING INTO THIS WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 53 31 62 47 / 0 0 20 60
KNOXVILLE MCGHEE TYSON AIRPORT, TN 49 29 60 44 / 0 0 10 60
OAK RIDGE, TN 46 29 59 45 / 0 0 20 60
TRI CITIES AIRPORT, TN 48 24 59 40 / 0 0 10 50
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
337 PM CST SUN DEC 14 2014
.DISCUSSION...
WATER VAPOR...INFRARED AND VISIBLE SATELLITE IMAGERY THIS
AFTERNOON SHOW A CLASSIC UPPER LEVEL LOW OVER THE WESTERN
OKLAHOMA PANHANDLE THIS AFTERNOON. THIS SYSTEM WILL MOVE EAST
NORTHEAST ACROSS KANSAS TONIGHT. A LINE OF SHOWERS AND
THUNDERSTORMS EXTENDED ALONG A BOWIE TO BROWNWOOD LINE AT 3 PM
WHILE SCATTERED SHOWERS CONTINUED EAST OF THE MAIN LINE OF
STORMS. THE INDIVIDUAL STORMS WILL MOVE NORTHEAST AT 35 TO 40 MPH
WHILE THE LINE TREKS EAST THROUGH TONIGHT. A FEW STORMS BETWEEN
MINERAL WELLS AND BROWNWOOD HAVE INTENSIFIED SOME DURING THE LAST
HOUR. SOME STRONG TO SEVERE STORMS WILL BE POSSIBLE THROUGH THIS
EVENING...WITH DAMAGING WINDS AND MAYBE SOME MARGINAL HAIL
POSSIBLE.
THE RAIN CHANCES WILL END FROM WEST TO EAST THIS EVENING THROUGH
THE OVERNIGHT HOURS WITH JUST LOW CHANCES LINGERING IN THE
PALESTINE TO HEARNE AREAS AFTER DAYBREAK MONDAY. LOWS TONIGHT WILL
RANGE FROM THE LOWER 40S ACROSS THE WEST TO AROUND 60 DEGREES IN
THE SOUTHEAST. WITH SURFACE WINDS SHIFTING TO THE WEST TOMORROW
MORNING AND NORTHWEST TOMORROW AFTERNOON BEHIND A PACIFIC COLD FRONT
AND ABUNDANT SUNSHINE...HIGH TEMPERATURES WILL RANGE FROM AROUND
60 IN THE NORTHWEST TO AROUND 70 SOUTHEAST. THE COOLER AIR BEHIND
A COLD FRONT WILL BE MORE NOTICED MONDAY NIGHT AS WE SEE LOWS IN
THE LOWER 30S NORTHWEST TO THE LOWER 40S SOUTHEAST. HIGHS TUESDAY
WILL BE MOSTLY IN THE 50S.
AS ANOTHER UPPER LEVEL TROUGH MOVES INTO THE WEST COAST LATE
TUESDAY...WE WILL COME INTO SOUTHWESTERLY FLOW ALOFT. CLOUDS WILL
ROLL BACK INTO THE REGION FROM SOUTHWEST TO NORTHEAST TUESDAY
NIGHT WITH LOWS RANGING FROM THE MID 30S NORTHEAST TO THE LOWER
40S SOUTH. A SERIES OF UPPER LEVEL DISTURBANCES WILL MOVE ACROSS
THE REGION AHEAD OF THE UPPER LEVEL SYSTEM GIVING US CHANCES OF
SHOWERS WEDNESDAY THROUGH FRIDAY. THE MODELS ARE STILL IN
CONSIDERABLE DISAGREEMENT AMONG THE GFS...ECMWF...AND CANADIAN ON
HOW THEY HANDLE THE UPPER LEVEL TROUGH. THE GFS INDICATES THAT A
CUT OFF LOW WILL MOVE FROM SOUTHERN CALIFORNIA THURSDAY...ACROSS
THE PERMIAN BASIN BY FRIDAY MORNING...AND THEN MOVE NORTHEAST
INTO NORTHEASTERN OKLAHOMA BY FRIDAY NIGHT. THE ECMWF AND
CANADIAN INDICATE THAT A WEAKER UPPER LEVEL TROUGH WILL MOVE
ACROSS THE REGION THURSDAY NIGHT INTO FRIDAY. AT THIS TIME...HAVE
GONE WITH A BLEND OF THE MODEL SOLUTIONS.
DRY WEATHER WILL PREVAIL SATURDAY AND AS THE TROUGH MOVES FARTHER
TO THE EAST AND WE WAIT FOR THE NEXT SYSTEM TO APPROACH EARLY
NEXT WEEK.
58
&&
.AVIATION...
/ISSUED 1122 AM CST SUN DEC 14 2014/
...CONVECTION REMAINS POSSIBLE AT ALL TAF LOCATIONS THIS
AFTERNOON...
AN UPPER LEVEL LOW PRESSURE CENTER CONTINUES TO TREK ACROSS THE
TEXAS PANHANDLE...AND WILL CONTINUE ITS EASTWARD MOTION INTO THE
PLAINS THIS AFTERNOON. ASCENT ARRIVING IN ADVANCE OF THE SYSTEM
HAS LED TO THE DEVELOPMENT OF SHOWERS AND A FEW ISOLATED
THUNDERSTORMS WEST OF THE I-35 CORRIDOR THIS MORNING. THUNDERSTORM
DEVELOPMENT WILL BECOME MORE WIDESPREAD THIS AFTERNOON AS LIFT
CONTINUES TO INCREASE...AND MODEST SURFACE HEATING HELPS
DESTABILIZE THE ATMOSPHERE. AT THIS TIME...WE STILL EXPECT STORMS
TO BE SCATTERED IN NATURE IN THE METROPLEX...BUT EVENTUALLY
SOLIDIFY INTO A SQUALL LINE AS THE SYSTEM SHIFTS EAST OF TAF SITES
THIS EVENING. FOR THIS REASON WE HAVE SIMPLY MAINTAINED VCTS IN
THE TAFS...BUT WILL NEED TO AMEND WITH A TEMPO FOR AN HOUR OR SO
IF ACTIVITY BEGINS TO SHOW ORGANIZATION BEFORE MOVING EAST OF THE
METRO AREA. FOR THIS FORECAST WE HAVE LEANED TOWARDS THE RAP ON
TIMING OF THE ONSET /20Z IN THE METRO AREA AND 22Z AT KACT/ AND
CESSATION /01Z IN THE METROPLEX AND 03Z AT KACT/ OF CONVECTION.
MVFR CONDITIONS WILL LIKELY HANG AROUND AT ALL LOCATIONS MUCH OF
THE DAY. SURFACE WINDS WILL VEER THIS EVENING AS THE STORMS SYSTEM
WORKS ITS WAY EAST OF THE REGION...BRINGING IN DRIER AIR AND
IMPROVING CIGS. WINDS WILL BECOME WESTERLY OVERNIGHT AS A PACIFIC
FRONT PUSHES THROUGH THE AREA...WITH SPEEDS 10-15 KT. THERE COULD
BE SOME MINOR CROSS WIND ISSUES AT DFW TOMORROW DUE TO THE WEST
WINDS...WHICH MAY OCCASIONALLY GUST TO AROUND 20 KT MONDAY
AFTERNOON. A SECOND PUSH OF COLD AIR WILL CREATE NORTHWEST WINDS
MONDAY EVENING...OR JUST BEYOND THE EXTENDED DFW FORECAST.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 50 65 39 54 38 / 40 0 0 5 5
WACO, TX 52 68 38 57 40 / 40 5 0 5 10
PARIS, TX 53 63 36 51 34 / 80 5 5 0 10
DENTON, TX 47 63 35 52 36 / 40 0 0 5 5
MCKINNEY, TX 50 63 35 52 35 / 60 5 0 5 5
DALLAS, TX 51 65 40 54 39 / 50 0 0 5 5
TERRELL, TX 53 65 38 53 37 / 70 5 0 5 5
CORSICANA, TX 56 67 39 57 40 / 60 5 0 5 5
TEMPLE, TX 54 68 38 59 42 / 30 5 0 5 10
MINERAL WELLS, TX 45 63 34 54 38 / 20 0 0 5 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
30/58
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1217 PM CST SUN DEC 14 2014
.UPDATE...
THERE ARE NO CHANGES TO BEING MADE TO THE MORNING FORECAST. THE
UPPER LEVEL LOW NEAR THE INTERSECTIONS OF NORTHEAST NEW MEXICO...AND
THE TEXAS AND OKLAHOMA PANHANDLES...WILL CONTINUE TO MOVE NORTHEAST
WITH SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED ACROSS NORTH AND
CENTRAL TEXAS THIS AFTERNOON AND TONIGHT. THERE REMAINS THE
POTENTIAL FOR A FEW STRONG TO SEVERE STORMS MID AFTERNOON INTO
THIS EVENING MAINLY ALONG AND EAST OF A BOWIE TO HILLSBORO LINE.
58
&&
.AVIATION...
/ISSUED 1122 AM CST SUN DEC 14 2014/
...CONVECTION REMAINS POSSIBLE AT ALL TAF LOCATIONS THIS
AFTERNOON...
AN UPPER LEVEL LOW PRESSURE CENTER CONTINUES TO TREK ACROSS THE
TEXAS PANHANDLE...AND WILL CONTINUE ITS EASTWARD MOTION INTO THE
PLAINS THIS AFTERNOON. ASCENT ARRIVING IN ADVANCE OF THE SYSTEM
HAS LED TO THE DEVELOPMENT OF SHOWERS AND A FEW ISOLATED
THUNDERSTORMS WEST OF THE I-35 CORRIDOR THIS MORNING. THUNDERSTORM
DEVELOPMENT WILL BECOME MORE WIDESPREAD THIS AFTERNOON AS LIFT
CONTINUES TO INCREASE...AND MODEST SURFACE HEATING HELPS
DESTABILIZE THE ATMOSPHERE. AT THIS TIME...WE STILL EXPECT STORMS
TO BE SCATTERED IN NATURE IN THE METROPLEX...BUT EVENTUALLY
SOLIDIFY INTO A SQUALL LINE AS THE SYSTEM SHIFTS EAST OF TAF SITES
THIS EVENING. FOR THIS REASON WE HAVE SIMPLY MAINTAINED VCTS IN
THE TAFS...BUT WILL NEED TO AMEND WITH A TEMPO FOR AN HOUR OR SO
IF ACTIVITY BEGINS TO SHOW ORGANIZATION BEFORE MOVING EAST OF THE
METRO AREA. FOR THIS FORECAST WE HAVE LEANED TOWARDS THE RAP ON
TIMING OF THE ONSET /20Z IN THE METRO AREA AND 22Z AT KACT/ AND
CESSATION /01Z IN THE METROPLEX AND 03Z AT KACT/ OF CONVECTION.
MVFR CONDITIONS WILL LIKELY HANG AROUND AT ALL LOCATIONS MUCH OF
THE DAY. SURFACE WINDS WILL VEER THIS EVENING AS THE STORMS SYSTEM
WORKS ITS WAY EAST OF THE REGION...BRINGING IN DRIER AIR AND
IMPROVING CIGS. WINDS WILL BECOME WESTERLY OVERNIGHT AS A PACIFIC
FRONT PUSHES THROUGH THE AREA...WITH SPEEDS 10-15 KT. THERE COULD
BE SOME MINOR CROSS WIND ISSUES AT DFW TOMORROW DUE TO THE WEST
WINDS...WHICH MAY OCCASIONALLY GUST TO AROUND 20 KT MONDAY
AFTERNOON. A SECOND PUSH OF COLD AIR WILL CREATE NORTHWEST WINDS
MONDAY EVENING...OR JUST BEYOND THE EXTENDED DFW FORECAST.
30
&&
.PREV DISCUSSION... /ISSUED 327 AM CST SUN DEC 14 2014/
RAIN CHANCES INCREASE ACROSS MUCH OF THE REGION TODAY AND TONIGHT
AS THE UPPER LEVEL TROUGH CONTINUES TO MOVE TOWARD THE SOUTH
PLAINS. 00Z UPPER AIR ANALYSIS HAD THE BASE OF THE TROUGH LOCATED
ROUGHLY BETWEEN SALT LAKE CITY AND PHOENIX...AND THE 08Z SATELLITE
DATA SUGGESTS THE BASE QUICKLY MOVING INTO NEW MEXICO. SYNOPTIC
SCALE AND MESOSCALE MODELS HAVE BEEN SUGGESTING THE TRANSITION TO
A CLOSED LOW OVER NEW MEXICO BY 12Z...AND THE SATELLITE DATA
CONFIRMS THAT THIS IS INDEED TAKING PLACE AS CIRCULATION CAN BE
SEEN IN THE SATELLITE DATA TO THE WEST OF KABQ. THIS FEATURE IS
EXPECTED TO MOVE NORTHEAST SOUTHERN KANSAS BY THIS EVENING.
AS THE UPPER LOW MOVES NORTHEAST...THERE WILL BE SUFFICIENT SYNOPTIC
SCALE LIFT ACROSS MUCH OF NORTH AND CENTRAL TEXAS. WITH ABUNDANT
MOISTURE IN PLACE...AND INCREASING WITH A STRONG SOUTHERLY LOW
LEVEL JET...THERE WILL BE A DECENT SHOT AT SHOWERS AND
THUNDERSTORMS TODAY. HAVE LEANED STRONGLY ON HIGH RESOLUTION
MESOSCALE MODELS...ESPECIALLY THE HRRR...FOR THE FORECAST
TODAY...INCREASING POPS FROM WEST TO EAST THROUGHOUT THE DAY. IF
ALL GOES ACCORDING TO PLAN...SHOWERS AND THUNDERSTORMS SHOULD
INCREASE IN COVERAGE BETWEEN 9 AM AND NOON TO THE WEST OF
I35/I35W. BETWEEN NOON AND 3 PM...EXPECT THE SHOWERS AND
THUNDERSTORMS TO IMPACT THE I35 CORRIDOR...INCLUDING BOTH I35W AND
I35E. THE STORMS WILL MOVE EAST FROM THERE AND PUSH EAST OF THE
AREA AFTER MIDNIGHT.
SEVERE WEATHER CHANCES TODAY ARE LOW...BUT NOT COMPLETELY OUT OF
THE QUESTION. FORECAST CAPE VALUES...AGAIN LEANING HEAVILY ON THE
HRRR...SUGGEST SOMEWHERE BETWEEN 500 AND 1000 J/KG WHICH IS NOT
TOO SHABBY FOR MID DECEMBER. LAPSE RATES SHOULD INCREASE AS THE
UPPER STORM MOVES CLOSER TO US...AND WOULD ALSO ANTICIPATE ANY CIN
TO DECREASE AS THE ENTIRE COLUMN COOLS IN RESPONSE TO SYNOPTIC
SCALE LIFT. WOULD EXPECT THAT ANY SEVERE STORM IS ISOLATED IN
COVERAGE AND WOULD BE THE EXCEPTION RATHER THAN THE RULE.
EXPECTING A PROGRESSIVE PATTERN TO CONTINUE FOR MUCH OF THE WEEK
AS TODAYS SYSTEM WILL GIVE WAY TO QUIETER WEATHER FOR MONDAY AND
TUESDAY. RAIN CHANCES INCREASE AGAIN WEDNESDAY AS THE NEXT WAVE
APPROACHES. POTENTIAL FOR RAIN CONTINUES THROUGH FRIDAY BEFORE A
RETURN TO RELATIVE QUIET FOR NEXT WEEKEND.
FOX
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 71 51 67 40 53 / 70 40 5 5 5
WACO, TX 70 51 67 40 57 / 60 50 5 5 10
PARIS, TX 66 53 63 37 51 / 70 80 10 5 5
DENTON, TX 70 47 64 36 53 / 70 30 5 5 5
MCKINNEY, TX 69 50 63 37 53 / 80 50 5 5 5
DALLAS, TX 71 51 67 41 54 / 70 40 5 5 5
TERRELL, TX 69 54 65 39 54 / 70 60 5 5 10
CORSICANA, TX 71 56 66 40 56 / 70 60 10 5 10
TEMPLE, TX 72 53 68 40 57 / 50 50 5 5 10
MINERAL WELLS, TX 71 43 64 35 55 / 40 10 5 5 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
30/58
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1122 AM CST SUN DEC 14 2014
.AVIATION...
...CONVECTION REMAINS POSSIBLE AT ALL TAF LOCATIONS THIS
AFTERNOON...
AN UPPER LEVEL LOW PRESSURE CENTER CONTINUES TO TREK ACROSS THE
TEXAS PANHANDLE...AND WILL CONTINUE ITS EASTWARD MOTION INTO THE
PLAINS THIS AFTERNOON. ASCENT ARRIVING IN ADVANCE OF THE SYSTEM
HAS LED TO THE DEVELOPMENT OF SHOWERS AND A FEW ISOLATED
THUNDERSTORMS WEST OF THE I-35 CORRIDOR THIS MORNING. THUNDERSTORM
DEVELOPMENT WILL BECOME MORE WIDESPREAD THIS AFTERNOON AS LIFT
CONTINUES TO INCREASE...AND MODEST SURFACE HEATING HELPS
DESTABILIZE THE ATMOSPHERE. AT THIS TIME...WE STILL EXPECT STORMS
TO BE SCATTERED IN NATURE IN THE METROPLEX...BUT EVENTUALLY
SOLIDIFY INTO A SQUALL LINE AS THE SYSTEM SHIFTS EAST OF TAF SITES
THIS EVENING. FOR THIS REASON WE HAVE SIMPLY MAINTAINED VCTS IN
THE TAFS...BUT WILL NEED TO AMEND WITH A TEMPO FOR AN HOUR OR SO
IF ACTIVITY BEGINS TO SHOW ORGANIZATION BEFORE MOVING EAST OF THE
METRO AREA. FOR THIS FORECAST WE HAVE LEANED TOWARDS THE RAP ON
TIMING OF THE ONSET /20Z IN THE METRO AREA AND 22Z AT KACT/ AND
CESSATION /01Z IN THE METROPLEX AND 03Z AT KACT/ OF CONVECTION.
MVFR CONDITIONS WILL LIKELY HANG AROUND AT ALL LOCATIONS MUCH OF
THE DAY. SURFACE WINDS WILL VEER THIS EVENING AS THE STORMS SYSTEM
WORKS ITS WAY EAST OF THE REGION...BRINGING IN DRIER AIR AND
IMPROVING CIGS. WINDS WILL BECOME WESTERLY OVERNIGHT AS A PACIFIC
FRONT PUSHES THROUGH THE AREA...WITH SPEEDS 10-15 KT. THERE COULD
BE SOME MINOR CROSS WIND ISSUES AT DFW TOMORROW DUE TO THE WEST
WINDS...WHICH MAY OCCASIONALLY GUST TO AROUND 20 KT MONDAY
AFTERNOON. A SECOND PUSH OF COLD AIR WILL CREATE NORTHWEST WINDS
MONDAY EVENING...OR JUST BEYOND THE EXTENDED DFW FORECAST.
30
&&
.PREV DISCUSSION... /ISSUED 327 AM CST SUN DEC 14 2014/
RAIN CHANCES INCREASE ACROSS MUCH OF THE REGION TODAY AND TONIGHT
AS THE UPPER LEVEL TROUGH CONTINUES TO MOVE TOWARD THE SOUTH
PLAINS. 00Z UPPER AIR ANALYSIS HAD THE BASE OF THE TROUGH LOCATED
ROUGHLY BETWEEN SALT LAKE CITY AND PHOENIX...AND THE 08Z SATELLITE
DATA SUGGESTS THE BASE QUICKLY MOVING INTO NEW MEXICO. SYNOPTIC
SCALE AND MESOSCALE MODELS HAVE BEEN SUGGESTING THE TRANSITION TO
A CLOSED LOW OVER NEW MEXICO BY 12Z...AND THE SATELLITE DATA
CONFIRMS THAT THIS IS INDEED TAKING PLACE AS CIRCULATION CAN BE
SEEN IN THE SATELLITE DATA TO THE WEST OF KABQ. THIS FEATURE IS
EXPECTED TO MOVE NORTHEAST SOUTHERN KANSAS BY THIS EVENING.
AS THE UPPER LOW MOVES NORTHEAST...THERE WILL BE SUFFICIENT SYNOPTIC
SCALE LIFT ACROSS MUCH OF NORTH AND CENTRAL TEXAS. WITH ABUNDANT
MOISTURE IN PLACE...AND INCREASING WITH A STRONG SOUTHERLY LOW
LEVEL JET...THERE WILL BE A DECENT SHOT AT SHOWERS AND
THUNDERSTORMS TODAY. HAVE LEANED STRONGLY ON HIGH RESOLUTION
MESOSCALE MODELS...ESPECIALLY THE HRRR...FOR THE FORECAST
TODAY...INCREASING POPS FROM WEST TO EAST THROUGHOUT THE DAY. IF
ALL GOES ACCORDING TO PLAN...SHOWERS AND THUNDERSTORMS SHOULD
INCREASE IN COVERAGE BETWEEN 9 AM AND NOON TO THE WEST OF
I35/I35W. BETWEEN NOON AND 3 PM...EXPECT THE SHOWERS AND
THUNDERSTORMS TO IMPACT THE I35 CORRIDOR...INCLUDING BOTH I35W AND
I35E. THE STORMS WILL MOVE EAST FROM THERE AND PUSH EAST OF THE
AREA AFTER MIDNIGHT.
SEVERE WEATHER CHANCES TODAY ARE LOW...BUT NOT COMPLETELY OUT OF
THE QUESTION. FORECAST CAPE VALUES...AGAIN LEANING HEAVILY ON THE
HRRR...SUGGEST SOMEWHERE BETWEEN 500 AND 1000 J/KG WHICH IS NOT
TOO SHABBY FOR MID DECEMBER. LAPSE RATES SHOULD INCREASE AS THE
UPPER STORM MOVES CLOSER TO US...AND WOULD ALSO ANTICIPATE ANY CIN
TO DECREASE AS THE ENTIRE COLUMN COOLS IN RESPONSE TO SYNOPTIC
SCALE LIFT. WOULD EXPECT THAT ANY SEVERE STORM IS ISOLATED IN
COVERAGE AND WOULD BE THE EXCEPTION RATHER THAN THE RULE.
EXPECTING A PROGRESSIVE PATTERN TO CONTINUE FOR MUCH OF THE WEEK
AS TODAYS SYSTEM WILL GIVE WAY TO QUIETER WEATHER FOR MONDAY AND
TUESDAY. RAIN CHANCES INCREASE AGAIN WEDNESDAY AS THE NEXT WAVE
APPROACHES. POTENTIAL FOR RAIN CONTINUES THROUGH FRIDAY BEFORE A
RETURN TO RELATIVE QUIET FOR NEXT WEEKEND.
FOX
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 71 51 67 40 53 / 70 40 5 5 5
WACO, TX 70 51 67 40 57 / 60 50 5 5 10
PARIS, TX 66 53 63 37 51 / 70 80 10 5 5
DENTON, TX 70 47 64 36 53 / 70 30 5 5 5
MCKINNEY, TX 69 50 63 37 53 / 80 50 5 5 5
DALLAS, TX 71 51 67 41 54 / 70 40 5 5 5
TERRELL, TX 69 54 65 39 54 / 70 60 5 5 10
CORSICANA, TX 71 56 66 40 56 / 70 60 10 5 10
TEMPLE, TX 72 53 68 40 57 / 50 50 5 5 10
MINERAL WELLS, TX 71 43 64 35 55 / 40 10 5 5 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
30/58
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1119 AM CST SUN DEC 14 2014
.DISCUSSION...
SEE 18Z AVIATION DISCUSSION.
&&
.AVIATION...
MODELS NOT IN THE BEST AGREEMENT ONCE AGAIN WITH REGARD TO RAIN
CHANCES AND MVFR/IFR CIGS. LATEST RAP AND 4 KM WRF KEEPS MOST OF
THE RAINFALL TO THE NW OF THE AREA WITH ONLY WIDELY SCATTERED
SHOWERS OVER AREA TAF SITES. FCST SOUNDINGS SHOW ONLY A SMALL
SATURATED PROFILE WITH CONSIDERABLE DRY AIR ALOFT. PARED BACK RAIN
CHANCES FOR THIS AFTN AS COVERAGE SHOULD REMAIN SPOTTY. WILL
BRIEFLY CARRY LIFR CIGS OVERNIGHT BUT NOT MUCH CONFIDENCE IN THIS
ACTUALLY OCCURRING. WINDS WILL BE GUSTY THIS AFTN AND TRENDED
HIGHER WITH BOTH SUSTAINED WINDS AND GUSTS. 43
&&
.PREV DISCUSSION... /ISSUED 1013 AM CST SUN DEC 14 2014/
UPDATE...
NO SIGNIFICANT CHANGES TO THE SHORT TERM GRIDS. AFTERNOON LOW END
RAIN CHANCES FOR PRIMARILY SHOWERS UP ACROSS THE NORTHERN THIRD
OF THE CWA WILL HEIGHTEN TO HIGH CHANCE/LIKELY FOR SHOWERS WITH
ISOLATED STORMS THROUGH EARLY MONDAY MORNING. THE IMPETUS WILL BE
THE DEVELOPING ROCKY MOUNTAIN LEESIDE LOW OVER SE CO AND OK/TX
PANHANDLES THAT WILL EJECT NORTHEAST THROUGH EARLY MONDAY...ITS
ASSOCIATED COLD FRONT TO PASS OVER THE REGION LATE MONDAY. UPPER
LEVEL SUPPORT IS NOT THERE...WITH CONTINUED DRY MID-UPPER LAYERS
WITHIN A MARGINALLY UNSTABLE PROFILE...TO PRODUCE NO MORE THAN
JUST SCATTERED SHOWERS FOR THE MAJORITY OF THE FORECAST AREA OVER
THE NEXT 24 TO 36 HOURS. DOWNSTREAM OF THIS FRONT...THE WARMEST
DAYS OF THE WEEK WITH MAXIMUM TEMPERATURES REGISTERING A NEAR 10
DEGREES ABOVE NORMAL PER MID DECEMBER STANDARDS. THE POST FRONTAL
AIR MASS WILL BE RELATIVELY COOLER...BUT MILD CONDITIONS WILL
STILL PERSIST THROUGH THIS LAST FULL WEEK OF AUTUMN AS CLOUDINESS
AND PERIODIC RAINFALL REGULATE DIURNAL TEMPERATURE FLUCTUATION. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 74 62 73 44 61 / 30 50 20 10 10
HOUSTON (IAH) 74 64 77 49 64 / 20 40 40 10 10
GALVESTON (GLS) 71 63 72 55 63 / 20 30 40 20 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH LATE TONIGHT FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
558 AM CST SUN DEC 14 2014
.AVIATION...
FOR THE 12Z TAFS...TIMING THE ONSET OF SHOWERS AND THUNDERSTORMS
NEAR AREA TAF SITES IS THE PRIMARY FORECAST CONCERN TODAY.
CLOSELY FOLLOWED THE LATEST HRRR MODEL GUIDANCE FOR TIMING THE
ONSET OF PRECIPITATION AT AREA TAF SITES TODAY. EXPECT SCATTERED
RAIN SHOWERS TO BEGIN TO DEVELOP ALONG THE INTERSTATE 35 CORRIDOR
BY LATE THIS MORNING. THINK THAT THE BEST CHANCE FOR THUNDERSTORMS
WILL EXIST AS UPPER LEVEL FORCING INCREASES ACROSS THE AREA THIS
AFTERNOON. WENT AHEAD WITH A MENTION OF VCTS IN THE TAFS FROM
20-23Z AS THIS IS WHEN THE HRRR...AND OTHER HIGH RESOLUTION
MODELS...INDICATE THE MOST INTENSE CONVECTION MOVES ACROSS THE DFW
AREA TODAY.
RAIN SHOWERS WILL REMAIN POSSIBLE UNTIL A DRYLINE TYPE BOUNDARY
MOVES EAST ACROSS THE AREA THIS EVENING. THE 06Z NAM HINTED THAT A
SECOND LINE OF THUNDERSTORMS MAY ACCOMPANY THIS BOUNDARY AS IT
MOVES ACROSS AREA TAF SITES AROUND 03Z...BUT JUST KEPT THINGS AS
RAIN SHOWERS AT THIS TIME. ANY THUNDERSTORMS TODAY WILL HAVE THE
POTENTIAL TO BRING SOME STRONG WINDS DOWN TO THE SURFACE.
MODELS INDICATE THAT A LOW-LEVEL JET OF 45-50 KTS WILL REMAIN IN
PLACE OVER NORTH AND CENTRAL TEXAS ALL DAY TODAY. ANY ORGANIZED
DOWNDRAFT COULD TRANSPORT THIS HIGH MOMENTUM AIR DOWN TO THE
SURFACE...RESULTING IN STRONG TO DAMAGING WINDS REACHING THE
GROUND. DID NOT PLACE STRONG WINDS IN THE TAFS RIGHT NOW AS THIS
WILL NEED TO BE HANDLED ON A SHORT TERM FORECAST BASIS.
BEHIND THE DRYLINE TYPE BOUNDARY/FRONT...SKIES WILL CLEAR OUT AS
DRIER AIR BUILDS ACROSS THE REGION. MODELS INDICATE THAT WINDS
WILL VEER FROM THE SOUTHWEST TO THE WEST AFTER SUNRISE MONDAY
MORNING AS A TRUE COLD FRONT MOVES SOUTH ACROSS THE SOUTHERN
PLAINS. WINDS APPEAR TO BE WEAK ENOUGH TO PREVENT ANY SIGNIFICANT
CROSSWIND ISSUES...HOWEVER WE WILL HAVE TO WATCH THIS PERIOD OF
WESTERLY WINDS VERY CLOSELY TOMORROW MORNING IN CASE WINDS ARE
STRONGER THAN ADVERTISED.
CAVANAUGH
&&
.PREV DISCUSSION... /ISSUED 327 AM CST SUN DEC 14 2014/
RAIN CHANCES INCREASE ACROSS MUCH OF THE REGION TODAY AND TONIGHT
AS THE UPPER LEVEL TROUGH CONTINUES TO MOVE TOWARD THE SOUTH
PLAINS. 00Z UPPER AIR ANALYSIS HAD THE BASE OF THE TROUGH LOCATED
ROUGHLY BETWEEN SALT LAKE CITY AND PHOENIX...AND THE 08Z SATELLITE
DATA SUGGESTS THE BASE QUICKLY MOVING INTO NEW MEXICO. SYNOPTIC
SCALE AND MESOSCALE MODELS HAVE BEEN SUGGESTING THE TRANSITION TO
A CLOSED LOW OVER NEW MEXICO BY 12Z...AND THE SATELLITE DATA
CONFIRMS THAT THIS IS INDEED TAKING PLACE AS CIRCULATION CAN BE
SEEN IN THE SATELLITE DATA TO THE WEST OF KABQ. THIS FEATURE IS
EXPECTED TO MOVE NORTHEAST SOUTHERN KANSAS BY THIS EVENING.
AS THE UPPER LOW MOVES NORTHEAST...THERE WILL BE SUFFICIENT SYNOPTIC
SCALE LIFT ACROSS MUCH OF NORTH AND CENTRAL TEXAS. WITH ABUNDANT
MOISTURE IN PLACE...AND INCREASING WITH A STRONG SOUTHERLY LOW
LEVEL JET...THERE WILL BE A DECENT SHOT AT SHOWERS AND
THUNDERSTORMS TODAY. HAVE LEANED STRONGLY ON HIGH RESOLUTION
MESOSCALE MODELS...ESPECIALLY THE HRRR...FOR THE FORECAST
TODAY...INCREASING POPS FROM WEST TO EAST THROUGHOUT THE DAY. IF
ALL GOES ACCORDING TO PLAN...SHOWERS AND THUNDERSTORMS SHOULD
INCREASE IN COVERAGE BETWEEN 9 AM AND NOON TO THE WEST OF
I35/I35W. BETWEEN NOON AND 3 PM...EXPECT THE SHOWERS AND
THUNDERSTORMS TO IMPACT THE I35 CORRIDOR...INCLUDING BOTH I35W AND
I35E. THE STORMS WILL MOVE EAST FROM THERE AND PUSH EAST OF THE
AREA AFTER MIDNIGHT.
SEVERE WEATHER CHANCES TODAY ARE LOW...BUT NOT COMPLETELY OUT OF
THE QUESTION. FORECAST CAPE VALUES...AGAIN LEANING HEAVILY ON THE
HRRR...SUGGEST SOMEWHERE BETWEEN 500 AND 1000 J/KG WHICH IS NOT
TOO SHABBY FOR MID DECEMBER. LAPSE RATES SHOULD INCREASE AS THE
UPPER STORM MOVES CLOSER TO US...AND WOULD ALSO ANTICIPATE ANY CIN
TO DECREASE AS THE ENTIRE COLUMN COOLS IN RESPONSE TO SYNOPTIC
SCALE LIFT. WOULD EXPECT THAT ANY SEVERE STORM IS ISOLATED IN
COVERAGE AND WOULD BE THE EXCEPTION RATHER THAN THE RULE.
EXPECTING A PROGRESSIVE PATTERN TO CONTINUE FOR MUCH OF THE WEEK
AS TODAYS SYSTEM WILL GIVE WAY TO QUIETER WEATHER FOR MONDAY AND
TUESDAY. RAIN CHANCES INCREASE AGAIN WEDNESDAY AS THE NEXT WAVE
APPROACHES. POTENTIAL FOR RAIN CONTINUES THROUGH FRIDAY BEFORE A
RETURN TO RELATIVE QUIET FOR NEXT WEEKEND.
FOX
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 71 51 67 40 53 / 70 40 5 5 5
WACO, TX 70 51 67 40 57 / 60 50 5 5 10
PARIS, TX 66 53 63 37 51 / 70 80 10 5 5
DENTON, TX 70 47 64 36 53 / 70 30 5 5 5
MCKINNEY, TX 69 50 63 37 53 / 80 50 5 5 5
DALLAS, TX 71 51 67 41 54 / 70 40 5 5 5
TERRELL, TX 69 54 65 39 54 / 70 60 5 5 10
CORSICANA, TX 71 56 66 40 56 / 70 60 10 5 10
TEMPLE, TX 72 53 68 40 57 / 50 50 5 5 10
MINERAL WELLS, TX 71 43 64 35 55 / 40 10 5 5 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1105 PM CST SAT DEC 13 2014
.AVIATION...
AVIATION CONCERNS WITH THIS TAF PACKAGE WILL BE MVFR TO IFR CIGS
TONIGHT/SUNDAY MORNING AND THUNDERSTORM CHANCES SUNDAY.
VAD WIND PROFILES FROM BOTH FWS AND GRK INDICATE A 35 KNOT LOW
LEVEL JET HAS SET UP ALREADY. LOW CLOUDS WERE DEVELOPING ACROSS
SOUTH TEXAS AND THE HILL COUNTRY LATE THIS EVENING AND THESE
CLOUDS SHOULD REACH ALL TAF SITES BETWEEN 06Z AND 07Z. CEILINGS
SHOULD FALL A BIT OVERNIGHT WITH SOME 800 TO 1000 FT CEILINGS
LIKELY BETWEEN 10Z AND 16Z. EXPECT LIFTING CEILINGS AFTER 16Z BUT
VFR CONDITIONS WILL MOST LIKELY NOT RETURN UNTIL LATE SUNDAY AFTERNOON.
LARGE SCALE LIFT WILL BE ON THE INCREASE OVERNIGHT AS A 4 CORNERS
UPPER LOW DEEPENS AND MOVES EAST/NORTHEAST. SCATTERED LIGHT
SHOWERS SUNDAY MORNING WILL INCREASE IN COVERAGE AND INTENSITY
THROUGH THE DAY SUNDAY. MID LEVEL INSTABILITY WILL SUPPORT
THUNDERSTORMS...MAINLY SUNDAY AFTERNOON. THE BEST WINDOW OF TIME
FOR STORMS AT THE METROPLEX TAF SITES WILL BE BETWEEN 20Z AND 00Z.
THUNDER IS LESS LIKELY IN WACO MAINLY DUE TO THE NORTHERN TRACK OF
THE UPPER LOW. ALL PRECIPITATION SHOULD MOVE EAST OF THE TAF SITES
EARLY SUNDAY EVENING AS A PUNCH OF DRY AIR COMES IN ON THE BACK
SIDE OF THE DEPARTING UPPER LOW.
SOUTHERLY WINDS WILL PREVAIL THROUGH SUNDAY AFTERNOON AT SPEEDS
BETWEEN 12 AND 19 KNOTS ALONG WITH A FEW HIGHER GUSTS...ESPECIALLY
SUNDAY AFTERNOON. THE WIND DIRECTION WILL BECOME MORE SOUTHWEST SUNDAY
EVENING AS THE SURFACE LOW MOVES INTO CENTRAL KANSAS AND A COLD
FRONT SWEEPS ACROSS THE STATE. WIND SPEEDS SHOULD DECREASE
SLIGHTLY SUNDAY NIGHT WHEN WIND DIRECTION BECOMES MORE SOUTHWESTERLY.
HOWEVER...SOME CROSS WIND ISSUES ARE LIKELY MONDAY WHEN WIND
SPEEDS INCREASE.
79
&&
.UPDATE...
SURFACE OBS AT MID EVENING CONTINUE TO SHOW A WEAK BOUNDARY NORTH
OF ARDMORE OKLAHOMA TO PARIS OR JUST TO THE NORTH OF SHREVEPORT.
CONSIDERABLE LOW CLOUDINESS AND FOG WERE OCCURRING ALONG AND NORTH
OF THE BOUNDARY. EXPECT AREAS NORTH OF PARIS WILL CONTINUE TO HAVE
SOME MIST OR FOG THE REST OF THE EVENING.
AN INCREASING LOW LEVEL JET IS DEVELOPING ACROSS THE REGION PER
BOTH KGRK AND KFWS 88D VAD WIND PROFILES. THIS WILL RESULT IN
INCREASING CLOUD COVER AS THE NIGHT PROGRESSES AND AREAS FOG
BEFORE DAYBREAK. BECAUSE OF INCREASED WIND SPEEDS IN THE OVERNIGHT
HOURS...WE DO NOT FEEL THE FOG WILL BECOME DENSE WITH MOST
LOCATIONS REMAINING ABOVE 3 MILES.
AS FOR TOMORROWS SYSTEM...MODELS ARE IN FAIRLY GOOD AGREE THAT THE
PRECIPITATION WILL BE ALONG AND AHEAD OF THE COLD FRONT AND THAT
AMOUNTS UP TO 1 INCH ARE MORE LIKELY ALONG AND NORTH OF I-20 AND
OVER THE EASTERN COUNTIES. THE CONVECTION SHOULD BE SCATTERED DURING THE
MORNING HOURS BUT WILL BECOME MORE LINEAR ALONG THE FRONT DURING
THE AFTERNOON AS IT PUSHES THROUGH THE METROPLEX AND INTO THE
EASTERN COUNTIES. WE ARE RELYING ON THE GFS/NAM/TT WRF SOLUTIONS
FOR FRONTAL TIMING AND CONVECTION COVERAGE AS THE HRRR IS NOT
AVAILABLE THIS EVENING. AS STATED OVER THE PAST FEW DAYS...STRONG
TO MARGINAL SEVERE THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON
AND EVENING HOURS DUE TO INCREASING INSTABILITY AND SOME CAPE
DURING THE AFTERNOON.
ONLY MINOR SHORT-TERM CHANGES MADE TO THE PREVIOUS FORECAST
PACKAGE. 75
&&
.PREV DISCUSSION... /ISSUED 358 PM CST SAT DEC 13 2014/
THE 3 PM SURFACE ANALYSIS INDICATED THAT A WARM FRONT HAD ALMOST
EXITED NORTH TEXAS...EXTENDING FROM NORTH OF GAINESVILLE AND
DENISON TO NEAR PARIS. WINDS WERE GENERALLY SOUTH AND SOUTHEAST TO
THE SOUTH OF THE BOUNDARY AND TEMPERATURES WERE IN THE UPPER 60S
TO MID 70S WHILE TO THE NORTH OF THE BOUNDARY WINDS WERE EASTERLY
AND TEMPERATURES WERE MOSTLY IN THE 50S.
EXPECT SKIES TO BECOME MOSTLY CLOUDY AREA WIDE TONIGHT. THE WARM
FRONT WILL CONTINUE TO LIFT NORTH OVERNIGHT AS A SURFACE LOW
DEEPENS OVER SOUTHEASTERN COLORADO. AREAS OF FOG WILL LIKELY
DEVELOP OVERNIGHT. SOME OF THE MODEL GUIDANCE ARE INDICATING THE
POTENTIAL FOR SOME DENSE FOG...BUT GIVEN THE FORECAST WIND
SPEEDS...WILL NOT MENTION THAT AT THIS TIME.
AS AN UPPER LEVEL LOW THAT IS CURRENTLY OVER NORTHWESTERN ARIZONA
MOVES EAST AND THEN NORTHEAST...SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS WEST TEXAS
OVERNIGHT. SOME OF THIS ACTIVITY WILL MOVE INTO THE WESTERN PART
OF THE NORTH TEXAS ZONES AROUND DAYBREAK AND MOVE EAST DURING THE
DAY SUNDAY. GIVEN THE STEEP LAPSE RATES...AND DECENT SHEAR...SOME
STRONG THUNDERSTORMS ARE POSSIBLE. THERE LIKELY BE LIMITED
INSTABILITY BUT STILL CANNOT RULE OUT SOME ISOLATED SEVERE STORMS
THAT WOULD PRODUCE LARGE HAIL AND DAMAGING WINDS.
THE RAIN WILL END FROM WEST TO EAST LATE SUNDAY AFTERNOON THROUGH
MONDAY MORNING...THOUGH SOME VERY LOW CHANCES OF MAY LINGER IN THE
EXTREME SOUTHEAST INTO MONDAY AFTERNOON.
LOW RAIN CHANCES WILL RETURN OVERNIGHT TUESDAY NIGHT AND WEDNESDAY
AS AN UPPER LEVEL DISTURBANCE MOVES IN FROM THE SOUTHWEST. AS A
LARGE UPPER LEVEL TROUGH MOVES EAST FROM THE SOUTHWESTERN U.S. WE
WILL CONTINUE TO SEE CHANCES OF SHOWERS...WITH SOME THUNDERSTORMS
LIKELY THURSDAY/THURSDAY NIGHT. RAIN CHANCES SHOULD BE ON THE
DECREASE FRIDAY AFTERNOON INTO FRIDAY NIGHT AS THE TROUGH MOVES TO
OUR EAST. THE ECMWF...GFS...AND CMC DISAGREE SOME ON THE TIMING
AND STRENGTH OF UPPER LEVEL TROUGH...BUT WE SHOULD SEE A DECENT
CHANCE OF RAIN WITH THIS SYSTEM. 58
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 58 71 50 64 40 / 5 70 40 5 5
WACO, TX 57 71 49 67 39 / 5 50 40 5 5
PARIS, TX 54 67 51 62 36 / 5 60 80 10 5
DENTON, TX 57 70 46 62 35 / 5 80 20 5 5
MCKINNEY, TX 57 68 48 63 36 / 5 80 40 5 5
DALLAS, TX 58 69 50 64 41 / 5 70 40 5 5
TERRELL, TX 57 70 53 64 39 / 5 60 60 10 5
CORSICANA, TX 58 71 54 67 40 / 5 50 60 10 5
TEMPLE, TX 58 71 52 68 39 / 5 40 50 5 5
MINERAL WELLS, TX 56 72 42 63 34 / 5 50 10 5 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
79/75
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
859 PM CST MON DEC 15 2014
.UPDATE...
A BREAK DURING THE EARLY EVENING IN THE DENSE FOG AS VSBYS ROSE
WITH STEADIER RAIN AND LIFT WITH VORT MAX PASSING THROUGH. BAND OF
HIGHER REFLECTIVITY SHOWERS ON RADAR OFFSHORE IN LINE WITH
ENHANCED LOW-LEVEL FRONTOGENESIS THAT LIFTS NORTH WITH VORT MAX.
HRRR AND 00Z NAM VSBY FORECASTS INDICATE 1/4 MILE OR LESS VSBYS
MOVE BACK IN TO THE LAKE SHORE COUNTIES BETWEEN 03Z AND 06Z WITH
BAGGY GRADIENT ASSOCIATED WITH THE SURFACE LOW AND INCREASED
SURFACE DEW POINTS...CONTINUING THROUGH THE OVERNIGHT. WILL HAVE
TO WATCH ADJOINING COUNTIES TO THE WEST FOR INCLUSION BASED ON NAM
FORECASTS. WILL LEAVE DENSE FOG ADVISORY AS IS.
&&
.AVIATION/06Z TAFS/...
PERIOD OF STEADIER RAIN BROUGHT VSBYS UP TO MVFR LEVELS THOUGH
IFR CIGS CONTINUE. NAM AND HRRR VSBY FORECASTS SHOW IFR VSBYS IN
FOG RETURNING BETWEEN 03Z AND 06Z AND LASTING THROUGH THE
OVERNIGHT...WITH IMPROVEMENT FROM WEST TO EAST REACHING THE
EASTERN TAF SITES AROUND/SHORTLY AFTER 12Z WITH COLDER...DRIER
AIR ADVECTING IN ON GUSTY NW WINDS BEHIND COLD FRONT. CIGS WILL BE
SLOWER TO RISE...WITH CIGS NOT EXPECTED TO REACH 1K FT OR HIGHER
UNTIL 21Z TO 00Z...AND MVFR LEVELS TOWARD THE END OF THE FORECAST
PERIOD.
&&
.MARINE...
MARINE DENSE FOG ADVISORY CONTINUES UNTIL 12Z TUESDAY...WITH VSBYS
RISING WITH COLDER...DRIER AIR ADVECTING IN ON INCREASING NW
WINDS BEHIND A COLD FRONT. A SMALL CRAFT ADVISORY WILL LIKELY BE
NEEDED FOR TUESDAY AFTERNOON AND EVENING AS THESE NW WINDS RISE TO
15 TO 25 KNOTS. THE OFFSHORE FETCH WILL KEEP HIGHER WAVES TOWARD
OPEN WATER.
&&
.PREV DISCUSSION... /ISSUED 411 PM CST MON DEC 15 2014/
TONIGHT AND TUESDAY...FORECAST CONFIDENCE...HIGH
PERIODIC RAIN SHOWERS WILL CONTINUE THROUGH THE NIGHT AS LOW
PRESSURE PASSES OVER NORTHERN ILLINOIS. EXPECT FOG TO DEVELOP AGAIN
ACROSS THE REGION. SOUNDINGS INDICATE A SATURATED ENVIRONMENT FROM
THE SURFACE TO MIDLEVELS THROUGH TUES MORNING. FOG MAY BE DENSE
AFTER MIDNIGHT MAINLY ACROSS THE SOUTHEAST WHERE ONSHORE FLOW THIS
EVENING WILL CONTRIBUTE TO ADDITIONAL MOISTURE.
COLD AIR ADVECTION ERODES LOW LEVEL INVERSION THIS EVENING AND
PROFILE IS ISOTHERMAL UP TO ABOUT 2000 FT. LITTLE CHANGE IN
OVERNIGHT TEMPERATURES EXPECTED FROM EVENING LOWS AND HIGH TEMPS
WILL OCCUR TUES MORNING AS COLD AIR ADVECTION CONTINUES DURING THE
DAY. TEMPERATURES ARE EXPECTED TO DROP TO NEAR FREEZING DURING THE
AFTERNOON SO A TRANSITION TO A RAIN/SNOW MIX IS EXPECTED AROUND
MIDDAY IN SOUTH-CENTRAL WI AND LATE AFTERNOON IN THE SOUTHEAST. A
FEW HOURS OF LIGHT SNOW IS POSSIBLE ON THE BACK EDGE OF PRECIP
WITH LITTLE TO NO ACCUMULATION.
BEHIND THE DEPARTING LOW WINDS WILL SHIFT NORTHWEST AND
INCREASE. MID LEVELS WILL BE DRYING ON TUES BEHIND THE COLD FRONT
BUT SOUNDINGS SHOW LOW LEVEL MOISTURE LINGERING. HENCE CLOUDS WILL
CONTINUE AFTER PRECIPITATION ENDS.
TUESDAY NIGHT THROUGH THURSDAY NIGHT...FORECAST CONFIDENCE
MEDIUM TO HIGH.
BRISK NWLY WINDS AND COLD ADVECTION TO CONTINUE TUE NT AND WED AS
THE UPPER TROUGH CURRENTLY OVER MANITOBA AND W ONTARIO CANADA
MOVES SEWD ACROSS THE STATE. 850 MB TEMPS TO DROP TO -10C BY 18Z
WED. THE COLD POOL WILL MOVE AWAY BY THU WITH POLAR HIGH PRESSURE
TO THEN PREVAIL OVER THE UPPER MS RIVER VALLEY.
THE SFC TEMPS WILL DEPEND ON CLOUD COVER WHICH IS UNCERTAIN. THE
TYPICAL MOIST LOW LEVELS OF THE NAM HANGS ONTO THE STRATUS RIGHT
INTO THU WHILE THE GFS SOUNDINGS SUGGEST MORE PTLY CLOUDY
CONDITIONS WITHIN THE COOLER AND DRIER AIRMASS. GIVEN NO SNOW
COVER...ANY SUNSHINE WILL AID IN MILDER TEMPS THAN WHAT MAY BE
EXPECTED. BELIEVE BROKEN STRATUS ARE LIKELY AT TIMES WITH THE
UPPER TROUGH PASSAGE ON WED ESPECIALLY OVER CENTRAL WI...THEN
TRENDING MORE PARTLY CLOUDY INTO THU. DID TREND A LITTLE ON THE
MILD SIDE FOR HIGH TEMPS BUT LOW TEMPS HAVE THE POTENTIAL TO BE
COLDER IF CLEARING HOLDS LONG ENOUGH AT NIGHT.
LONG TERM...FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM.
THE WRN GREAT LAKES WILL REMAIN BETWEEN THE NRN AND SRN JET
STREAMS WITH LITTLE FLOW ALOFT. A N-S SFC RIDGE WILL PREVAIL OVER
THE REGION DURING THIS TIME WITH SLOWLY RISING HIGH TEMPS IN THE
30S.
AVIATION/00Z TAFS/...
EXPECT MAINLY IFR CONDITIONS OR LESS TO CONTINUE THROUGH TUES
MORNING. DENSE FOG IS LIKELY AT TIMES AT MKE AND ENW DUE TO A
MOIST SOUTHEAST FLOW. IT MAY ALSO DEVELOP AT MSN AND UES BUT THERE
IS MORE UNCERTAINTY AT THE THESE LOCATIONS.
WINDS WILL INCREASE TUESDAY AND SHIFT TO THE NORTHWEST WHICH WILL
HELP SCOUR OUT LOW CLOUDS SOMEWHAT IN THE AFTERNOON. MAY SEE NEAR
MVFR CONDITIONS LATE TUES AFTERNOON AT MSN THEN SPREADING TO EASTERN
TAF SITES.
PERIODIC RAIN SHOWERS EXPECTED THROUGH TUES MORNING. EXPECTING A
TRANSITION TO A RAIN/SNOW MIX MIDDAY WITH SOME LIGHT SNOW SHOWERS
POSSIBLE LATE IN THE AFTERNOON AT MSN AND EARLY EVENING AT EASTERN
TAF SITES. NO SNOW ACCUMULATION EXPECTED.
MARINE...
ONSHORE WINDS AND RELATIVELY HIGH LOW LEVEL MOISTURE WILL RESULT
IN PERSISTENT DENSE FOG ACROSS THE NEARSHORE WATERS THROUGH
TONIGHT. WINDS WILL SHIFT OFFSHORE TUESDAY MORNING...LIKELY
BRINGING DRIER AIR AND AN END TO THE DENSE FOG.
NORTHWEST WINDS WILL BECOME GUSTY BY TUESDAY AFTERNOON...WITH
HIGHER WINDS PERSISTING INTO THE NIGHT. A SMALL CRAFT ADVISORY
WILL LIKELY BE NEEDED FOR THIS PERIOD.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 7 AM CST TUESDAY FOR WIZ052-060-066-071-
072.
LM...DENSE FOG ADVISORY UNTIL 7 AM CST TUESDAY FOR LMZ643>646.
&&
$$
UPDATE...REM
TONIGHT/TUESDAY AND AVIATION/MARINE...SM
TUESDAY NIGHT THROUGH MONDAY...DAVIS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1135 AM CST SUN DEC 14 2014
.UPDATE...
ISSUED AT 910 AM CST SUN DEC 14 2014
NOT MUCH IMPROVEMENT IN VISIBILITIES EXPECTED THROUGH MONDAY
MORNING AS MILD/MOIST AIRMASS IS LIFTED ACROSS THE REGION.
THEREFORE THE DENSE FOG ADVISORY HAS BEEN EXTENDED THROUGH NOON
MONDAY.
UPDATE ISSUED AT 528 AM CST SUN DEC 14 2014
BECOMING VERY CONCERNED THAT THE DENSE FOG ADVISORY MAY NEED TO BE
EXTENDED FOR THE ENTIRE FORECAST AREA...POSSIBLY INTO MONDAY.
WITH UPPER 40S AND LOW TO MID 50S DEWPOINTS LURKING SOUTH OF THE
AREA NEAR I-80 BEING SHOVED NORTHWARD INTO OUR RELATIVELY SPEAKING
COLDER AIRMASS...ITS POSSIBLE THIS DENSE FOG GOES NOWHERE. ON TOP
OF THAT...LIGHTER WINDS ARE PROGGED TONIGHT...FAVORING LOW
VISIBILITIES. 14.10Z LAV GUIDANCE AT MOST SITES THAT ARE CURRENTLY
EXPERIENCING 1/4 MILE OR LESS VISIBILITIES...SUCH AS RST...CCY AND
MDZ...SHOWS THOSE VISIBILITIES PERSISTING THROUGH 11Z MONDAY...THE
END OF ITS RUN. WE MAY END UP HAVING TO WAIT FOR THE RAIN ON
MONDAY TO HELP IMPROVE VISIBILITIES SOMEWHAT...THOUGH DENSE FOG
COULD EASILY REFORM AFTER THE RAIN TAILS OFF. SOMETIME AFTER
MIDNIGHT MONDAY NIGHT APPEARS WHEN WE CAN FINALLY GET RID OF THE
FOG CONCERN...ACCOMPANYING THE COLD ADVECTION REGIME DEVELOPING
THEN.
HAVE NOT DONE ANY EXTENSIONS TO THE CURRENT ADVISORY...BUT THEY
COULD HAPPEN AT ANYTIME THROUGHOUT THE MORNING. THE HIGHEST
CONFIDENCE FOR THE DENSE FOG TO PERSIST IS ACROSS TAYLOR AND
CLARK COUNTIES...WHICH COINCIDES WITH THE COLDEST FORECAST
READINGS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 255 AM CST SUN DEC 14 2014
THE MAIN FORECAST CONCERN CONTINUES TO BE THE PRECIPITATION
CHANCES THROUGH THE PERIOD.
LOCAL OBSERVATIONS CONTINUE TO SHOW DENSE FOG WITH VISIBILITIES OF
A QUARTER MILE OR LESS COVERING A GOOD SHARE OF THE AREA. THE
14.05Z RAP BUFKIT SOUNDINGS SUGGEST THE WINDS JUST ABOVE THE
SURFACE MAY DIMINISH A LITTLE BIT THROUGH THE REST OF THE NIGHT
INTO SUNDAY MORNING WITH A SLOWLY DEEPENING SATURATED LAYER. THIS
MAY ALLOW THE DENSE FOG TO BECOME A LITTLE MORE WIDESPREAD AND FOR
THE AREAS THAT HAVE DECENT VISIBILITY TO GO DOWN SOME. PLAN TO
LEAVE THE DENSE FOG ADVISORY IN PLACE WITH NO CHANGES.
STILL DEALING WITH THE ISSUE OF HOW MUCH IF ANY DRIZZLE IS
OCCURRING WITH THE FOG. BASED ON PERSONAL OBSERVATIONS...MUCH LESS
DRIZZLE WAS OCCURRING IN THE LOCAL AREA SATURDAY EVENING THAN
PREVIOUS NIGHTS. THE RAP CONTINUES TO SUGGEST THAT WHAT OMEGA
THERE WILL BE IN THE SATURATED LAYER WILL BE VERY NEAR THE TOP OF
THIS LAYER. THE 14.00Z GFS ALSO CONTINUES TO SHOW JUST SOME VERY
WEAK ISENTROPIC UP GLIDE OF 1 UBAR/S OR LESS ON THE 290K SURFACE.
WILL MAINTAIN THE MENTION OF DRIZZLE FOR THE ENTIRE DAY...BUT WILL
LOWER THE PRECIPITATION CHANCES OF MEASURABLE DOWN TO THE 2O TO 30
PERCENT RANGE. THIS WILL ALSO GIVE AREAS INSTEAD OF WIDESPREAD
DRIZZLE WHICH MOST LIKELY WILL BETTER FIT THE SCENARIO AS WELL.
THE MAIN PRECIPITATION EVENT STILL LOOKS TO MONDAY AND MONDAY
NIGHT. THE UPPER LEVEL LOW LIFTING OUT OF THE DESERT SOUTHWEST IS
EXPECTED TO MOVE INTO THE LOWER MISSOURI RIVER VALLEY TONIGHT AS
ANOTHER UPPER LEVEL LOW DROPS SOUTH FROM CENTRAL CANADA. EVEN
THOUGH THE MAIN UPPER LEVEL RIDGE WILL BE OVER THE EASTERN
CONUS...THE GFS SUGGESTS A SECONDARY RIDGE AXIS WILL EXTEND OFF
THE MAIN RIDGE AXIS ACROSS THE UPPER MIDWEST BETWEEN THE TWO UPPER
LEVEL LOWS. THIS WOULD KEEP THE MAJORITY OF THE FORCING AWAY FROM
THE AREA WITH THE GFS SUGGESTING JUST SOME WEAK QG CONVERGENCE
OCCURRING ACROSS THE WESTERN SECTIONS OF THE AREA WITH JUST THE
VERY WEAK ISENTROPIC UP GLIDE CONTINUING ON THE 290K SURFACE. WILL
TRIM THE RAIN CHANCES BACK TO THE 20 TO 40 PERCENT RANGE FOR THE
EVENING AND THEN ALLOW AN INCREASE TO 60 PERCENT ACROSS THE WEST
FOR LATE TONIGHT.
THE UPPER LEVEL LOW FROM THE SOUTHWEST IS THEN EXPECTED TO MOVE
ACROSS THE AREA MONDAY INTO MONDAY NIGHT BRINGING MODERATE TO
STRONG PV ADVECTION IN THE 500-300 MB ACROSS THE AREA. THE QG
CONVERGENCE WILL BECOME DEEP THROUGH THE 1000-300 MB LAYER AND
SHOULD BE MODERATE IN STRENGTH. THE ISENTROPIC UP GLIDE AHEAD OF
THE LOW WILL ALSO INCREASE WITH THE GFS SHOWING UP TO 10 UBAR/S ON
THE 290K SURFACE BY MONDAY AFTERNOON. WITH THE INCREASED
FORCING...EXPECT THE PRECIPITATION TO BECOME PRETTY WIDESPREAD AND
WILL HAVE 70 TO 80 PERCENT CHANCES FOR THE ENTIRE AREA.
TEMPERATURES WILL CONTINUE TO BE WARM ENOUGH TO KEEP THIS AS ALL
RAIN. THE FORCING WILL NOT START TO DECREASE UNTIL LATE MONDAY
NIGHT...SO WILL CONTINUE WITH THE HIGH PRECIPITATION CHANCES UNTIL
DROPPING THEM DOWN TO ABOUT 60 PERCENT IN THE SOUTHWEST BY LATE
MONDAY NIGHT. BY THIS TIME...THE SURFACE WILL HAVE PASSED BY THE
REGION ALLOWING COLDER AIR TO SPREAD ACROSS THE REGION. THIS WILL
ALLOW FOR A TRANSITION OVER TO SNOW MONDAY NIGHT INTO TUESDAY
MORNING. NOT EXPECTING ANY MIXED PRECIPITATION ISSUES WITH ICE
REMAINING IN THE CLOUDS UNTIL THE PRECIPITATION COMES TO AN END.
SNOWFALL AMOUNTS NOT EXPECTED TO A WHOLE LOT WITH MAYBE UP TO A
HALF INCH OF ACCUMULATION FOR PORTIONS OF SOUTHEAST MINNESOTA
INTO NORTH CENTRAL WISCONSIN.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 255 AM CST SUN DEC 14 2014
FINALLY STARTING TO SEE A CONSENSUS BETWEEN THE MODELS WITH HOW
THE CANADIAN UPPER LEVEL LOW IS HANDLED. THE GFS LOOKS TO HAVE
COME AROUND TO SHOWING THE SAME EVOLUTION THAT THE ECMWF HAS BEEN
SHOWING FOR SEVERAL RUNS. THE UPPER LEVEL LOW IS EXPECTED TO COME
DOWN OVER THE NORTHERN GREAT LAKES TUESDAY NIGHT AND CONTINUE TO
BE PROGRESSIVE AND MOVE OFF THE NORTHEAST COAST THURSDAY NIGHT.
THIS WILL ALLOW HIGH PRESSURE TO BUILD IN AT THE SURFACE BEHIND
THE EARLY WEEK SYSTEM AND THEN REMAIN OVER THE UPPER MIDWEST FOR
THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1135 AM CST SUN DEC 14 2014
PERSISTENT UNSEASONABLY MILD/MOIST SOUTHERLY AIRFLOW FROM THE
GULF OF MEXICO WILL KEEP IFR/LIFR CONDITIONS IN PLACE ACROSS THE
UPPER MISSISSIPPI RIVER VALLEY INCLUDING KRST/KLSE RIGHT THROUGH
MONDAY. SOME REPRIEVE OF THESE POOR VIS/CIG CONDITIONS MAY TAKE
PLACE MONDAY AFTERNOON AS RAIN MOVES IN AHEAD OF LOW PRESSURE
MOVING OUT OF THE PLAINS.
&&
.CLIMATE...
ISSUED AT 255 AM CST SUN DEC 14 2014
UNSEASONABLY MILD AIR REMAINS OVER THE AREA TODAY. THE RECORD HIGH
AT ROCHESTER IS 52 AND 56 FOR LA CROSSE. WHILE IT DOES NOT LOOK
LIKE LA CROSSE WILL COME CLOSE TO SETTING A RECORD...IT WILL BE
VERY CLOSE FOR ROCHESTER WITH A CURRENT FORECAST OF 51. THE
CLOUDY SKIES AND FOG MAY END UP BEING THE LIMITING FACTOR IF
TEMPERATURES DO NOT WARM AS MUCH AS EXPECTED.
ON THE OTHER HAND...RECORD WARM LOWS ARE ALL BUT CERTAIN FOR
TODAY. THE CURRENT RECORD WARM LOW AT ROCHESTER IS 37 SET IN 1928
WHILE LA CROSSE IS 41 SET IN 1891. THE CURRENT EXPECTATION IS THAT
TEMPERATURES WILL REMAIN IN THE 40S THROUGH MIDNIGHT TONIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL NOON CST MONDAY FOR WIZ017-029-032>034-
041>044-053>055-061.
MN...DENSE FOG ADVISORY UNTIL NOON CST MONDAY FOR MNZ079-086>088-
094>096.
IA...DENSE FOG ADVISORY UNTIL NOON CST MONDAY FOR IAZ008>011-018-019-
029-030.
&&
$$
UPDATE...DAS
SHORT TERM...04
LONG TERM...04
AVIATION...DAS
CLIMATE...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
910 AM CST SUN DEC 14 2014
.UPDATE...
ISSUED AT 910 AM CST SUN DEC 14 2014
NOT MUCH IMPROVEMENT IN VISIBILITIES EXPECTED THROUGH MONDAY
MORNING AS MILD/MOIST AIRMASS IS LIFTED ACROSS THE REGION.
THEREFORE THE DENSE FOG ADVISORY HAS BEEN EXTENDED THROUGH NOON
MONDAY.
UPDATE ISSUED AT 528 AM CST SUN DEC 14 2014
BECOMING VERY CONCERNED THAT THE DENSE FOG ADVISORY MAY NEED TO BE
EXTENDED FOR THE ENTIRE FORECAST AREA...POSSIBLY INTO MONDAY.
WITH UPPER 40S AND LOW TO MID 50S DEWPOINTS LURKING SOUTH OF THE
AREA NEAR I-80 BEING SHOVED NORTHWARD INTO OUR RELATIVELY SPEAKING
COLDER AIRMASS...ITS POSSIBLE THIS DENSE FOG GOES NOWHERE. ON TOP
OF THAT...LIGHTER WINDS ARE PROGGED TONIGHT...FAVORING LOW
VISIBILITIES. 14.10Z LAV GUIDANCE AT MOST SITES THAT ARE CURRENTLY
EXPERIENCING 1/4 MILE OR LESS VISIBILITIES...SUCH AS RST...CCY AND
MDZ...SHOWS THOSE VISIBILITIES PERSISTING THROUGH 11Z MONDAY...THE
END OF ITS RUN. WE MAY END UP HAVING TO WAIT FOR THE RAIN ON
MONDAY TO HELP IMPROVE VISIBILITIES SOMEWHAT...THOUGH DENSE FOG
COULD EASILY REFORM AFTER THE RAIN TAILS OFF. SOMETIME AFTER
MIDNIGHT MONDAY NIGHT APPEARS WHEN WE CAN FINALLY GET RID OF THE
FOG CONCERN...ACCOMPANYING THE COLD ADVECTION REGIME DEVELOPING
THEN.
HAVE NOT DONE ANY EXTENSIONS TO THE CURRENT ADVISORY...BUT THEY
COULD HAPPEN AT ANYTIME THROUGHOUT THE MORNING. THE HIGHEST
CONFIDENCE FOR THE DENSE FOG TO PERSIST IS ACROSS TAYLOR AND
CLARK COUNTIES...WHICH COINCIDES WITH THE COLDEST FORECAST
READINGS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 255 AM CST SUN DEC 14 2014
THE MAIN FORECAST CONCERN CONTINUES TO BE THE PRECIPITATION
CHANCES THROUGH THE PERIOD.
LOCAL OBSERVATIONS CONTINUE TO SHOW DENSE FOG WITH VISIBILITIES OF
A QUARTER MILE OR LESS COVERING A GOOD SHARE OF THE AREA. THE
14.05Z RAP BUFKIT SOUNDINGS SUGGEST THE WINDS JUST ABOVE THE
SURFACE MAY DIMINISH A LITTLE BIT THROUGH THE REST OF THE NIGHT
INTO SUNDAY MORNING WITH A SLOWLY DEEPENING SATURATED LAYER. THIS
MAY ALLOW THE DENSE FOG TO BECOME A LITTLE MORE WIDESPREAD AND FOR
THE AREAS THAT HAVE DECENT VISIBILITY TO GO DOWN SOME. PLAN TO
LEAVE THE DENSE FOG ADVISORY IN PLACE WITH NO CHANGES.
STILL DEALING WITH THE ISSUE OF HOW MUCH IF ANY DRIZZLE IS
OCCURRING WITH THE FOG. BASED ON PERSONAL OBSERVATIONS...MUCH LESS
DRIZZLE WAS OCCURRING IN THE LOCAL AREA SATURDAY EVENING THAN
PREVIOUS NIGHTS. THE RAP CONTINUES TO SUGGEST THAT WHAT OMEGA
THERE WILL BE IN THE SATURATED LAYER WILL BE VERY NEAR THE TOP OF
THIS LAYER. THE 14.00Z GFS ALSO CONTINUES TO SHOW JUST SOME VERY
WEAK ISENTROPIC UP GLIDE OF 1 UBAR/S OR LESS ON THE 290K SURFACE.
WILL MAINTAIN THE MENTION OF DRIZZLE FOR THE ENTIRE DAY...BUT WILL
LOWER THE PRECIPITATION CHANCES OF MEASURABLE DOWN TO THE 2O TO 30
PERCENT RANGE. THIS WILL ALSO GIVE AREAS INSTEAD OF WIDESPREAD
DRIZZLE WHICH MOST LIKELY WILL BETTER FIT THE SCENARIO AS WELL.
THE MAIN PRECIPITATION EVENT STILL LOOKS TO MONDAY AND MONDAY
NIGHT. THE UPPER LEVEL LOW LIFTING OUT OF THE DESERT SOUTHWEST IS
EXPECTED TO MOVE INTO THE LOWER MISSOURI RIVER VALLEY TONIGHT AS
ANOTHER UPPER LEVEL LOW DROPS SOUTH FROM CENTRAL CANADA. EVEN
THOUGH THE MAIN UPPER LEVEL RIDGE WILL BE OVER THE EASTERN
CONUS...THE GFS SUGGESTS A SECONDARY RIDGE AXIS WILL EXTEND OFF
THE MAIN RIDGE AXIS ACROSS THE UPPER MIDWEST BETWEEN THE TWO UPPER
LEVEL LOWS. THIS WOULD KEEP THE MAJORITY OF THE FORCING AWAY FROM
THE AREA WITH THE GFS SUGGESTING JUST SOME WEAK QG CONVERGENCE
OCCURRING ACROSS THE WESTERN SECTIONS OF THE AREA WITH JUST THE
VERY WEAK ISENTROPIC UP GLIDE CONTINUING ON THE 290K SURFACE. WILL
TRIM THE RAIN CHANCES BACK TO THE 20 TO 40 PERCENT RANGE FOR THE
EVENING AND THEN ALLOW AN INCREASE TO 60 PERCENT ACROSS THE WEST
FOR LATE TONIGHT.
THE UPPER LEVEL LOW FROM THE SOUTHWEST IS THEN EXPECTED TO MOVE
ACROSS THE AREA MONDAY INTO MONDAY NIGHT BRINGING MODERATE TO
STRONG PV ADVECTION IN THE 500-300 MB ACROSS THE AREA. THE QG
CONVERGENCE WILL BECOME DEEP THROUGH THE 1000-300 MB LAYER AND
SHOULD BE MODERATE IN STRENGTH. THE ISENTROPIC UP GLIDE AHEAD OF
THE LOW WILL ALSO INCREASE WITH THE GFS SHOWING UP TO 10 UBAR/S ON
THE 290K SURFACE BY MONDAY AFTERNOON. WITH THE INCREASED
FORCING...EXPECT THE PRECIPITATION TO BECOME PRETTY WIDESPREAD AND
WILL HAVE 70 TO 80 PERCENT CHANCES FOR THE ENTIRE AREA.
TEMPERATURES WILL CONTINUE TO BE WARM ENOUGH TO KEEP THIS AS ALL
RAIN. THE FORCING WILL NOT START TO DECREASE UNTIL LATE MONDAY
NIGHT...SO WILL CONTINUE WITH THE HIGH PRECIPITATION CHANCES UNTIL
DROPPING THEM DOWN TO ABOUT 60 PERCENT IN THE SOUTHWEST BY LATE
MONDAY NIGHT. BY THIS TIME...THE SURFACE WILL HAVE PASSED BY THE
REGION ALLOWING COLDER AIR TO SPREAD ACROSS THE REGION. THIS WILL
ALLOW FOR A TRANSITION OVER TO SNOW MONDAY NIGHT INTO TUESDAY
MORNING. NOT EXPECTING ANY MIXED PRECIPITATION ISSUES WITH ICE
REMAINING IN THE CLOUDS UNTIL THE PRECIPITATION COMES TO AN END.
SNOWFALL AMOUNTS NOT EXPECTED TO A WHOLE LOT WITH MAYBE UP TO A
HALF INCH OF ACCUMULATION FOR PORTIONS OF SOUTHEAST MINNESOTA
INTO NORTH CENTRAL WISCONSIN.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 255 AM CST SUN DEC 14 2014
FINALLY STARTING TO SEE A CONSENSUS BETWEEN THE MODELS WITH HOW
THE CANADIAN UPPER LEVEL LOW IS HANDLED. THE GFS LOOKS TO HAVE
COME AROUND TO SHOWING THE SAME EVOLUTION THAT THE ECMWF HAS BEEN
SHOWING FOR SEVERAL RUNS. THE UPPER LEVEL LOW IS EXPECTED TO COME
DOWN OVER THE NORTHERN GREAT LAKES TUESDAY NIGHT AND CONTINUE TO
BE PROGRESSIVE AND MOVE OFF THE NORTHEAST COAST THURSDAY NIGHT.
THIS WILL ALLOW HIGH PRESSURE TO BUILD IN AT THE SURFACE BEHIND
THE EARLY WEEK SYSTEM AND THEN REMAIN OVER THE UPPER MIDWEST FOR
THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 528 AM CST SUN DEC 14 2014
THE PERSISTENT FLOW OF GULF OF MEXICO MOISTURE INTO COOLER AIR
OVER THE TAF SITES CONTINUES TO PRODUCE FOG AND STRATUS. CEILINGS
ARE STUCK AT LIFR WHILE VISIBILITIES ARE HOLDING AT VLIFR AT RST
AND IFR AT LSE. ANTICIPATING LITTLE CHANGE IN THESE CONDITIONS
DURING THE MORNING. DAYTIME HEATING MAY...UNDERSCORE MAY...IMPROVE
CONDITIONS A LITTLE FOR THE AFTERNOON. BROUGHT RST UP TO LIFR IN
VISIBILITY...AND AT LSE MVFR IN VISIBILITY AND IFR IN CEILING...
BASED ON WHAT HAPPENED YESTERDAY. HOWEVER...RST COULD EASILY STAY
STUCK AT VLIFR IN VISIBILITY THE WHOLE AFTERNOON. CONDITIONS WILL
GO DOWNHILL AGAIN TONIGHT WITH SLIGHTLY LIGHTER WINDS PROGGED AND
THE FLOW OF MOISTURE CONTINUING.
LOOKING AHEAD...A BRIEF REPRIEVE FROM THE POOR VISIBILITIES IS
POSSIBLE DURING THE LATE MORNING AND AFTERNOON ON MONDAY AS RAIN
MOVES THROUGH THE TAF SITES. STILL...ONCE THE RAIN TAILS OFF...IT
LOOKS TO BE BACK IN THE THICK FOG. SOMETIME BETWEEN 05-10Z TUESDAY
APPEARS TO BE WHEN THE FOG WILL FINALLY BEGIN TO EXIT THE TAF
SITES.
&&
.CLIMATE...
ISSUED AT 255 AM CST SUN DEC 14 2014
UNSEASONABLY MILD AIR REMAINS OVER THE AREA TODAY. THE RECORD HIGH
AT ROCHESTER IS 52 AND 56 FOR LA CROSSE. WHILE IT DOES NOT LOOK
LIKE LA CROSSE WILL COME CLOSE TO SETTING A RECORD...IT WILL BE
VERY CLOSE FOR ROCHESTER WITH A CURRENT FORECAST OF 51. THE
CLOUDY SKIES AND FOG MAY END UP BEING THE LIMITING FACTOR IF
TEMPERATURES DO NOT WARM AS MUCH AS EXPECTED.
ON THE OTHER HAND...RECORD WARM LOWS ARE ALL BUT CERTAIN FOR
TODAY. THE CURRENT RECORD WARM LOW AT ROCHESTER IS 37 SET IN 1928
WHILE LA CROSSE IS 41 SET IN 1891. THE CURRENT EXPECTATION IS THAT
TEMPERATURES WILL REMAIN IN THE 40S THROUGH MIDNIGHT TONIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL NOON CST MONDAY FOR WIZ017-029-032>034-
041>044-053>055-061.
MN...DENSE FOG ADVISORY UNTIL NOON CST MONDAY FOR MNZ079-086>088-
094>096.
IA...DENSE FOG ADVISORY UNTIL NOON CST MONDAY FOR IAZ008>011-018-019-
029-030.
&&
$$
UPDATE...DAS
SHORT TERM...04
LONG TERM...04
AVIATION...AJ
CLIMATE...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
528 AM CST SUN DEC 14 2014
.UPDATE...
ISSUED AT 528 AM CST SUN DEC 14 2014
BECOMING VERY CONCERNED THAT THE DENSE FOG ADVISORY MAY NEED TO BE
EXTENDED FOR THE ENTIRE FORECAST AREA...POSSIBLY INTO MONDAY.
WITH UPPER 40S AND LOW TO MID 50S DEWPOINTS LURKING SOUTH OF THE
AREA NEAR I-80 BEING SHOVED NORTHWARD INTO OUR RELATIVELY SPEAKING
COLDER AIRMASS...ITS POSSIBLE THIS DENSE FOG GOES NOWHERE. ON TOP
OF THAT...LIGHTER WINDS ARE PROGGED TONIGHT...FAVORING LOW
VISIBILITIES. 14.10Z LAV GUIDANCE AT MOST SITES THAT ARE CURRENTLY
EXPERIENCING 1/4 MILE OR LESS VISIBILITIES...SUCH AS RST...CCY AND
MDZ...SHOWS THOSE VISIBILITIES PERSISTING THROUGH 11Z MONDAY...THE
END OF ITS RUN. WE MAY END UP HAVING TO WAIT FOR THE RAIN ON
MONDAY TO HELP IMPROVE VISIBILITIES SOMEWHAT...THOUGH DENSE FOG
COULD EASILY REFORM AFTER THE RAIN TAILS OFF. SOMETIME AFTER
MIDNIGHT MONDAY NIGHT APPEARS WHEN WE CAN FINALLY GET RID OF THE
FOG CONCERN...ACCOMPANYING THE COLD ADVECTION REGIME DEVELOPING
THEN.
HAVE NOT DONE ANY EXTENSIONS TO THE CURRENT ADVISORY...BUT THEY
COULD HAPPEN AT ANYTIME THROUGHOUT THE MORNING. THE HIGHEST
CONFIDENCE FOR THE DENSE FOG TO PERSIST IS ACROSS TAYLOR AND
CLARK COUNTIES...WHICH COINCIDES WITH THE COLDEST FORECAST
READINGS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 255 AM CST SUN DEC 14 2014
THE MAIN FORECAST CONCERN CONTINUES TO BE THE PRECIPITATION
CHANCES THROUGH THE PERIOD.
LOCAL OBSERVATIONS CONTINUE TO SHOW DENSE FOG WITH VISIBILITIES OF
A QUARTER MILE OR LESS COVERING A GOOD SHARE OF THE AREA. THE
14.05Z RAP BUFKIT SOUNDINGS SUGGEST THE WINDS JUST ABOVE THE
SURFACE MAY DIMINISH A LITTLE BIT THROUGH THE REST OF THE NIGHT
INTO SUNDAY MORNING WITH A SLOWLY DEEPENING SATURATED LAYER. THIS
MAY ALLOW THE DENSE FOG TO BECOME A LITTLE MORE WIDESPREAD AND FOR
THE AREAS THAT HAVE DECENT VISIBILITY TO GO DOWN SOME. PLAN TO
LEAVE THE DENSE FOG ADVISORY IN PLACE WITH NO CHANGES.
STILL DEALING WITH THE ISSUE OF HOW MUCH IF ANY DRIZZLE IS
OCCURRING WITH THE FOG. BASED ON PERSONAL OBSERVATIONS...MUCH LESS
DRIZZLE WAS OCCURRING IN THE LOCAL AREA SATURDAY EVENING THAN
PREVIOUS NIGHTS. THE RAP CONTINUES TO SUGGEST THAT WHAT OMEGA
THERE WILL BE IN THE SATURATED LAYER WILL BE VERY NEAR THE TOP OF
THIS LAYER. THE 14.00Z GFS ALSO CONTINUES TO SHOW JUST SOME VERY
WEAK ISENTROPIC UP GLIDE OF 1 UBAR/S OR LESS ON THE 290K SURFACE.
WILL MAINTAIN THE MENTION OF DRIZZLE FOR THE ENTIRE DAY...BUT WILL
LOWER THE PRECIPITATION CHANCES OF MEASURABLE DOWN TO THE 2O TO 30
PERCENT RANGE. THIS WILL ALSO GIVE AREAS INSTEAD OF WIDESPREAD
DRIZZLE WHICH MOST LIKELY WILL BETTER FIT THE SCENARIO AS WELL.
THE MAIN PRECIPITATION EVENT STILL LOOKS TO MONDAY AND MONDAY
NIGHT. THE UPPER LEVEL LOW LIFTING OUT OF THE DESERT SOUTHWEST IS
EXPECTED TO MOVE INTO THE LOWER MISSOURI RIVER VALLEY TONIGHT AS
ANOTHER UPPER LEVEL LOW DROPS SOUTH FROM CENTRAL CANADA. EVEN
THOUGH THE MAIN UPPER LEVEL RIDGE WILL BE OVER THE EASTERN
CONUS...THE GFS SUGGESTS A SECONDARY RIDGE AXIS WILL EXTEND OFF
THE MAIN RIDGE AXIS ACROSS THE UPPER MIDWEST BETWEEN THE TWO UPPER
LEVEL LOWS. THIS WOULD KEEP THE MAJORITY OF THE FORCING AWAY FROM
THE AREA WITH THE GFS SUGGESTING JUST SOME WEAK QG CONVERGENCE
OCCURRING ACROSS THE WESTERN SECTIONS OF THE AREA WITH JUST THE
VERY WEAK ISENTROPIC UP GLIDE CONTINUING ON THE 290K SURFACE. WILL
TRIM THE RAIN CHANCES BACK TO THE 20 TO 40 PERCENT RANGE FOR THE
EVENING AND THEN ALLOW AN INCREASE TO 60 PERCENT ACROSS THE WEST
FOR LATE TONIGHT.
THE UPPER LEVEL LOW FROM THE SOUTHWEST IS THEN EXPECTED TO MOVE
ACROSS THE AREA MONDAY INTO MONDAY NIGHT BRINGING MODERATE TO
STRONG PV ADVECTION IN THE 500-300 MB ACROSS THE AREA. THE QG
CONVERGENCE WILL BECOME DEEP THROUGH THE 1000-300 MB LAYER AND
SHOULD BE MODERATE IN STRENGTH. THE ISENTROPIC UP GLIDE AHEAD OF
THE LOW WILL ALSO INCREASE WITH THE GFS SHOWING UP TO 10 UBAR/S ON
THE 290K SURFACE BY MONDAY AFTERNOON. WITH THE INCREASED
FORCING...EXPECT THE PRECIPITATION TO BECOME PRETTY WIDESPREAD AND
WILL HAVE 70 TO 80 PERCENT CHANCES FOR THE ENTIRE AREA.
TEMPERATURES WILL CONTINUE TO BE WARM ENOUGH TO KEEP THIS AS ALL
RAIN. THE FORCING WILL NOT START TO DECREASE UNTIL LATE MONDAY
NIGHT...SO WILL CONTINUE WITH THE HIGH PRECIPITATION CHANCES UNTIL
DROPPING THEM DOWN TO ABOUT 60 PERCENT IN THE SOUTHWEST BY LATE
MONDAY NIGHT. BY THIS TIME...THE SURFACE WILL HAVE PASSED BY THE
REGION ALLOWING COLDER AIR TO SPREAD ACROSS THE REGION. THIS WILL
ALLOW FOR A TRANSITION OVER TO SNOW MONDAY NIGHT INTO TUESDAY
MORNING. NOT EXPECTING ANY MIXED PRECIPITATION ISSUES WITH ICE
REMAINING IN THE CLOUDS UNTIL THE PRECIPITATION COMES TO AN END.
SNOWFALL AMOUNTS NOT EXPECTED TO A WHOLE LOT WITH MAYBE UP TO A
HALF INCH OF ACCUMULATION FOR PORTIONS OF SOUTHEAST MINNESOTA
INTO NORTH CENTRAL WISCONSIN.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 255 AM CST SUN DEC 14 2014
FINALLY STARTING TO SEE A CONSENSUS BETWEEN THE MODELS WITH HOW
THE CANADIAN UPPER LEVEL LOW IS HANDLED. THE GFS LOOKS TO HAVE
COME AROUND TO SHOWING THE SAME EVOLUTION THAT THE ECMWF HAS BEEN
SHOWING FOR SEVERAL RUNS. THE UPPER LEVEL LOW IS EXPECTED TO COME
DOWN OVER THE NORTHERN GREAT LAKES TUESDAY NIGHT AND CONTINUE TO
BE PROGRESSIVE AND MOVE OFF THE NORTHEAST COAST THURSDAY NIGHT.
THIS WILL ALLOW HIGH PRESSURE TO BUILD IN AT THE SURFACE BEHIND
THE EARLY WEEK SYSTEM AND THEN REMAIN OVER THE UPPER MIDWEST FOR
THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 528 AM CST SUN DEC 14 2014
THE PERSISTENT FLOW OF GULF OF MEXICO MOISTURE INTO COOLER AIR
OVER THE TAF SITES CONTINUES TO PRODUCE FOG AND STRATUS. CEILINGS
ARE STUCK AT LIFR WHILE VISIBILITIES ARE HOLDING AT VLIFR AT RST
AND IFR AT LSE. ANTICIPATING LITTLE CHANGE IN THESE CONDITIONS
DURING THE MORNING. DAYTIME HEATING MAY...UNDERSCORE MAY...IMPROVE
CONDITIONS A LITTLE FOR THE AFTERNOON. BROUGHT RST UP TO LIFR IN
VISIBILITY...AND AT LSE MVFR IN VISIBILITY AND IFR IN CEILING...
BASED ON WHAT HAPPENED YESTERDAY. HOWEVER...RST COULD EASILY STAY
STUCK AT VLIFR IN VISIBILITY THE WHOLE AFTERNOON. CONDITIONS WILL
GO DOWNHILL AGAIN TONIGHT WITH SLIGHTLY LIGHTER WINDS PROGGED AND
THE FLOW OF MOISTURE CONTINUING.
LOOKING AHEAD...A BRIEF REPRIEVE FROM THE POOR VISIBILITIES IS
POSSIBLE DURING THE LATE MORNING AND AFTERNOON ON MONDAY AS RAIN
MOVES THROUGH THE TAF SITES. STILL...ONCE THE RAIN TAILS OFF...IT
LOOKS TO BE BACK IN THE THICK FOG. SOMETIME BETWEEN 05-10Z TUESDAY
APPEARS TO BE WHEN THE FOG WILL FINALLY BEGIN TO EXIT THE TAF
SITES.
&&
.CLIMATE...
ISSUED AT 255 AM CST SUN DEC 14 2014
UNSEASONABLY MILD AIR REMAINS OVER THE AREA TODAY. THE RECORD HIGH
AT ROCHESTER IS 52 AND 56 FOR LA CROSSE. WHILE IT DOES NOT LOOK
LIKE LA CROSSE WILL COME CLOSE TO SETTING A RECORD...IT WILL BE
VERY CLOSE FOR ROCHESTER WITH A CURRENT FORECAST OF 51. THE
CLOUDY SKIES AND FOG MAY END UP BEING THE LIMITING FACTOR IF
TEMPERATURES DO NOT WARM AS MUCH AS EXPECTED.
ON THE OTHER HAND...RECORD WARM LOWS ARE ALL BUT CERTAIN FOR
TODAY. THE CURRENT RECORD WARM LOW AT ROCHESTER IS 37 SET IN 1928
WHILE LA CROSSE IS 41 SET IN 1891. THE CURRENT EXPECTATION IS THAT
TEMPERATURES WILL REMAIN IN THE 40S THROUGH MIDNIGHT TONIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR WIZ017-029-032>034-
041>044-053>055-061.
MN...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR MNZ079-086>088-
094>096.
IA...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR IAZ008>011-018-019-
029-030.
&&
$$
UPDATE...AJ
SHORT TERM...04
LONG TERM...04
AVIATION...AJ
CLIMATE...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
256 AM CST SUN DEC 14 2014
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 255 AM CST SUN DEC 14 2014
THE MAIN FORECAST CONCERN CONTINUES TO BE THE PRECIPITATION
CHANCES THROUGH THE PERIOD.
LOCAL OBSERVATIONS CONTINUE TO SHOW DENSE FOG WITH VISIBILITIES OF
A QUARTER MILE OR LESS COVERING A GOOD SHARE OF THE AREA. THE
14.05Z RAP BUFKIT SOUNDINGS SUGGEST THE WINDS JUST ABOVE THE
SURFACE MAY DIMINISH A LITTLE BIT THROUGH THE REST OF THE NIGHT
INTO SUNDAY MORNING WITH A SLOWLY DEEPENING SATURATED LAYER. THIS
MAY ALLOW THE DENSE FOG TO BECOME A LITTLE MORE WIDESPREAD AND FOR
THE AREAS THAT HAVE DECENT VISIBILITY TO GO DOWN SOME. PLAN TO
LEAVE THE DENSE FOG ADVISORY IN PLACE WITH NO CHANGES.
STILL DEALING WITH THE ISSUE OF HOW MUCH IF ANY DRIZZLE IS
OCCURRING WITH THE FOG. BASED ON PERSONAL OBSERVATIONS...MUCH LESS
DRIZZLE WAS OCCURRING IN THE LOCAL AREA SATURDAY EVENING THAN
PREVIOUS NIGHTS. THE RAP CONTINUES TO SUGGEST THAT WHAT OMEGA
THERE WILL BE IN THE SATURATED LAYER WILL BE VERY NEAR THE TOP OF
THIS LAYER. THE 14.00Z GFS ALSO CONTINUES TO SHOW JUST SOME VERY
WEAK ISENTROPIC UP GLIDE OF 1 UBAR/S OR LESS ON THE 290K SURFACE.
WILL MAINTAIN THE MENTION OF DRIZZLE FOR THE ENTIRE DAY...BUT WILL
LOWER THE PRECIPITATION CHANCES OF MEASURABLE DOWN TO THE 2O TO 30
PERCENT RANGE. THIS WILL ALSO GIVE AREAS INSTEAD OF WIDESPREAD
DRIZZLE WHICH MOST LIKELY WILL BETTER FIT THE SCENARIO AS WELL.
THE MAIN PRECIPITATION EVENT STILL LOOKS TO MONDAY AND MONDAY
NIGHT. THE UPPER LEVEL LOW LIFTING OUT OF THE DESERT SOUTHWEST IS
EXPECTED TO MOVE INTO THE LOWER MISSOURI RIVER VALLEY TONIGHT AS
ANOTHER UPPER LEVEL LOW DROPS SOUTH FROM CENTRAL CANADA. EVEN
THOUGH THE MAIN UPPER LEVEL RIDGE WILL BE OVER THE EASTERN
CONUS...THE GFS SUGGESTS A SECONDARY RIDGE AXIS WILL EXTEND OFF
THE MAIN RIDGE AXIS ACROSS THE UPPER MIDWEST BETWEEN THE TWO UPPER
LEVEL LOWS. THIS WOULD KEEP THE MAJORITY OF THE FORCING AWAY FROM
THE AREA WITH THE GFS SUGGESTING JUST SOME WEAK QG CONVERGENCE
OCCURRING ACROSS THE WESTERN SECTIONS OF THE AREA WITH JUST THE
VERY WEAK ISENTROPIC UP GLIDE CONTINUING ON THE 290K SURFACE. WILL
TRIM THE RAIN CHANCES BACK TO THE 20 TO 40 PERCENT RANGE FOR THE
EVENING AND THEN ALLOW AN INCREASE TO 60 PERCENT ACROSS THE WEST
FOR LATE TONIGHT.
THE UPPER LEVEL LOW FROM THE SOUTHWEST IS THEN EXPECTED TO MOVE
ACROSS THE AREA MONDAY INTO MONDAY NIGHT BRINGING MODERATE TO
STRONG PV ADVECTION IN THE 500-300 MB ACROSS THE AREA. THE QG
CONVERGENCE WILL BECOME DEEP THROUGH THE 1000-300 MB LAYER AND
SHOULD BE MODERATE IN STRENGTH. THE ISENTROPIC UP GLIDE AHEAD OF
THE LOW WILL ALSO INCREASE WITH THE GFS SHOWING UP TO 10 UBAR/S ON
THE 290K SURFACE BY MONDAY AFTERNOON. WITH THE INCREASED
FORCING...EXPECT THE PRECIPITATION TO BECOME PRETTY WIDESPREAD AND
WILL HAVE 70 TO 80 PERCENT CHANCES FOR THE ENTIRE AREA.
TEMPERATURES WILL CONTINUE TO BE WARM ENOUGH TO KEEP THIS AS ALL
RAIN. THE FORCING WILL NOT START TO DECREASE UNTIL LATE MONDAY
NIGHT...SO WILL CONTINUE WITH THE HIGH PRECIPITATION CHANCES UNTIL
DROPPING THEM DOWN TO ABOUT 60 PERCENT IN THE SOUTHWEST BY LATE
MONDAY NIGHT. BY THIS TIME...THE SURFACE WILL HAVE PASSED BY THE
REGION ALLOWING COLDER AIR TO SPREAD ACROSS THE REGION. THIS WILL
ALLOW FOR A TRANSITION OVER TO SNOW MONDAY NIGHT INTO TUESDAY
MORNING. NOT EXPECTING ANY MIXED PRECIPITATION ISSUES WITH ICE
REMAINING IN THE CLOUDS UNTIL THE PRECIPITATION COMES TO AN END.
SNOWFALL AMOUNTS NOT EXPECTED TO A WHOLE LOT WITH MAYBE UP TO A
HALF INCH OF ACCUMULATION FOR PORTIONS OF SOUTHEAST MINNESOTA
INTO NORTH CENTRAL WISCONSIN.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 255 AM CST SUN DEC 14 2014
FINALLY STARTING TO SEE A CONSENSUS BETWEEN THE MODELS WITH HOW
THE CANADIAN UPPER LEVEL LOW IS HANDLED. THE GFS LOOKS TO HAVE
COME AROUND TO SHOWING THE SAME EVOLUTION THAT THE ECMWF HAS BEEN
SHOWING FOR SEVERAL RUNS. THE UPPER LEVEL LOW IS EXPECTED TO COME
DOWN OVER THE NORTHERN GREAT LAKES TUESDAY NIGHT AND CONTINUE TO
BE PROGRESSIVE AND MOVE OFF THE NORTHEAST COAST THURSDAY NIGHT.
THIS WILL ALLOW HIGH PRESSURE TO BUILD IN AT THE SURFACE BEHIND
THE EARLY WEEK SYSTEM AND THEN REMAIN OVER THE UPPER MIDWEST FOR
THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1120 PM CST SAT DEC 13 2014
VISIBILITY HAS IMPROVED SLIGHTLY LATE THIS EVENING INTO THE 1/2 TO
1 1/2SM RANGE. EXPECT THIS TO CONTINUE THROUGH THE NIGHT AT KLSE WITH
FURTHER DECREASES TO 1/4SM MAINLY AT KRST SOMETIME AFTER 14.09Z.
LOWER VISIBILITY POSSIBLE AT KLSE...BUT CONFIDENCE NOT HIGH
ENOUGH TO INCLUDE IN 14.06Z TAF ISSUANCE. CEILINGS FROM 200 TO 300
FT AGL WILL CONTINUE THROUGH THE NIGHT AND INTO SUNDAY MORNING
WITH VERY LITTLE IMPROVEMENT AFTER 14.17Z. VISIBILITY FORECAST TO
DROP AGAIN AFTER 15.00Z TO 1SM OR LESS IN FOG/MIST.
&&
.CLIMATE...
ISSUED AT 255 AM CST SUN DEC 14 2014
UNSEASONABLY MILD AIR REMAINS OVER THE AREA TODAY. THE RECORD HIGH
AT ROCHESTER IS 52 AND 56 FOR LA CROSSE. WHILE IT DOES NOT LOOK
LIKE LA CROSSE WILL COME CLOSE TO SETTING A RECORD...IT WILL BE
VERY CLOSE FOR ROCHESTER WITH A CURRENT FORECAST OF 51. THE
CLOUDY SKIES AND FOG MAY END UP BEING THE LIMITING FACTOR IF
TEMPERATURES DO NOT WARM AS MUCH AS EXPECTED.
ON THE OTHER HAND...IT LOOKS LIKE WE STAND A VERY GOOD CHANCE AT
BREAKING THE RECORD WARM LOWS FOR TODAY. THE CURRENT RECORD WARM
LOW AT ROCHESTER IS 37 SET IN 1928 WHILE LA CROSSE IS 41 SET IN
1891. THE CURRENT EXPECTATION IS THAT TEMPERATURES WILL REMAIN IN
THE 40S THROUGH MIDNIGHT TONIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR WIZ017-029-032>034-
041>044-053>055-061.
MN...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR MNZ079-086>088-
094>096.
IA...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...ROGERS
CLIMATE...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
825 PM MST MON DEC 15 2014
.UPDATE...
ISSUED AT 815 PM MST MON DEC 15 2014
VERY TRICKY TEMPERATURE FORECAST FOR TONIGHT. LATEST FOG/STRATUS
SATELLITE LOOP AND AIRPORT OBSERVATIONS SHOW A LLVL STRATUS DECK
DRAPED FROM EAST CENTRAL WY SOUTHEASTWARD TOWARD ALLIANCE IN THE
NEBRASKA PANHANDLE. UPSTREAM SFC OBS AND HIGH-RES MODELS WOULD
SUGGEST BLYR MOISTURE WILL REMAIN HIGH FOR MUCH OF THE OVERNIGHT
PERIOD VIA LIGHT NORTHWEST WINDS. LATEST RUNS OF THE HRRR HANG ON
TO THE STRATUS THROUGH SUNRISE TUE. SO DESPITE SEVERAL INCHES OF
FRESH SNOW...THIS WILL HAVE AN IMPACT ON TEMPS. OPTED TO RAISE
LOWS A FEW DEGREES. DID NOT GO AS HIGH AS THE HRRR/RAP YET IN CASE
CLOUDS ACTUALLY DO CLEAR OUT. COULD SEE SOME PATCHY FOG WITH THE
ENHANCED NEAR-SFC MOISTURE...ESPECIALLY OVER THE WESTERN NEBRASKA
PANHANDLE. WILL CONTINUE TO MONITOR TRENDS THROUGH THE EVENING FOR
ANY ADDITIONAL UPDATES.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 335 PM MST MON DEC 15 2014
MID AFTERNOON WATER VAPOR IMAGERY SHOWED THE STACKED LOW PRESSURE
SYSTEM THAT BROUGHT HEAVY SNOW AND GUSTY NORTHWEST WINDS TO THE
HIGH PLAINS WAS TRACKING EAST ACROSS THE MISSOURI VALLEY.
REGIONAL RADAR...SURFACE OBSERVATIONS AND HIGHWAY WEB CAMS
REVEALED SLOWLY IMPROVING CONDITIONS ACROSS THE WESTERN NEBRASKA
PANHANDLE. RECENTLY CANCELLED THE WINTER STORM WARNING AND WEATHER
ADVISORY THAT WAS IN EFFECT UNTIL 3 PM. GUSTY NORTHWEST WINDS OF
25 TO 35 MPH WILL DECREASE LATER THIS AFTERNOON AND EARLY EVENING.
SNOW HAS TAPERED OFF TO FLURRIES OVER THE SOUTHERN NEBRASKA
PANHANDLE. TEMPERATURES WILL CHILLY WITH READINGS IN THE 20S AND
30S...AND WIND CHILLS IN THE SINGLE DIGITS AND TEENS.
LATEST NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT WITH THE LARGE
SCALE PATTERN. THE STORM SYSTEM OVER THE MIDWEST WILL CONTINUE ITS
EASTWARD TREK ACROSS OHIO VALLEY INTO NEW ENGLAND TUESDAY...WITH A
SECONDARY PIECE OF ENERGY ROTATING THROUGH THE GREAT LAKES. MEANWHILE...
A SHORTWAVE RIDGE WILL SLIDE EAST ACROSS THE FRONT RANGE AND HIGH
PLAINS THROUGH TUESDAY NIGHT...AS THE NEXT PACIFIC TROUGH MOVES
THROUGH THE SOUTHERN GREAT BASIN AND FOUR CORNERS REGION WEDNESDAY.
A WEAKER PRESSURE GRADIENT WILL RESULT IN LIGHTER WINDS DURING THE
SHORT TERM.
WITH PARTIAL CLEARING...LIGHT WINDS AND MOIST BOUNDARY LAYER ACROSS
THE HIGH PLAINS...CONCERN WILL BE PATCHY FOG DEVELOPMENT WITH
STRENGTHENING LOW LEVEL INVERSION. DUE TO FRESH SNOW
PACK...TRENDED CLOSER TO THE COLDER MAVMOS FOR MIN TEMPERATURES
TONIGHT...WITH WIDESPREAD SINGLE DIGITS FOR THE HIGH PLAINS AND
VALLEYS OF SOUTHEAST WY. A FEW LOCATIONS IN THE WESTERN PANHANDLE
COULD DROP TO AROUND 0 DEGREES. THERE WILL BE ENOUGH OF A WESTERLY
WIND COMPONENT TO KEEP TEMPERATURES IN THE LOWER TEENS ELSEWHERE.
INCREASING MID/UPPER LEVEL MOISTURE WILL SPREAD FROM SOUTHWEST TO
NORTHEAST TUESDAY WITH THE APPROACH AND PASSAGE OF THE RIDGE.
THERE WILL BE SOME MOISTURE AND WEAK UPSLOPE FOR LIGHT SNOW OVER
THE SOUTHERN MOUNTAINS. HIGH TEMPERATURES TUESDAY WILL SLIGHTLY
BELOW SEASONAL NORMALS WITH 20S AND 30S. TUESDAY NIGHT WILL NOT BE
AS COLD WITH A MORE SOUTHWESTERLY WIND COMPONENT AND CLOUD COVER
KEEPING MIN TEMPERATURES MOSTLY IN THE TEENS TO AROUND 20. SOME
UPPER SINGLE DIGITS WILL BE POSSIBLE FOR PORTIONS OF THE WESTERN
PANHANDLE. WEDNESDAY WILL BE A CARBON COPY OF TUESDAY WITH MOSTLY
CLOUDY SKIES...COOL TEMPERATURES AND LIGHT OROGRAPHIC SNOWFALL FOR
THE SOUTHERN MOUNTAINS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 258 PM MST MON DEC 15 2014
WEDNESDAY NIGHT/THURSDAY...RATHER MOIST WESTERLY FLOW ALOFT WILL
CONTINUE THE SCATTERED SNOW SHOWERS OVER OUR SNOWY AND SIERRA MADRE
RANGES...DRY ELSEWHERE.
FRIDAY...PRIMARY SHORTWAVE TROUGH ALOFT MOVES ACROSS OUR COUNTIES
WITH DECREASING COVERAGE OF SHOWERS IN THE AFTERNOON...THOUGH IT
WILL BE BREEZY TO WINDY PER PROGGED LOW AND MID LEVEL GRADIENTS.
SATURDAY...CONTINUED BREEZY TO WINDY PER PROGGED LOW AND MID LEVEL
GRADIENTS. SHOULD BE DRY WITH LIMITED LOW AND MID LEVEL MOISTURE AND
LIFT...THOUGH WITH PERIODS OF MIDDLE AND HIGH CLOUDS.
SUNDAY...WINDY PERIOD DEVELOPS WITH STRONG NORTHWEST FLOW ALOFT AND
PROGGED LOW AND MID LEVEL GRADIENTS INCREASING
MONDAY...EVEN WINDIER AS THE PROGGED LOW AND MID LEVEL GRADIENTS
INCREASE SIGNIFICANTLY WITH NORTHWEST FLOW ALOFT. LOOKS LIKE ENOUGH
MID LEVEL MOISTURE FOR SCATTERED OROGRAPHIC SNOW SHOWERS OVER THE
SNOWY AND SIERRA MADRE RANGES...DRY ELSEWHERE. SEASONABLE
TEMPERATURES...THOUGH STILL QUITE WINDY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 431 PM MST MON DEC 15 2014
VFR PREVAILS...EXCEPT FOR PERIODS OF MVFR AND IFR LATE TONIGHT
AND EARLY TUESDAY...MAINLY AT CHEYENNE...CHADRON...ALLIANCE...
SCOTTSBLUFF AND SIDNEY.
&&
.FIRE WEATHER...
ISSUED AT 300 PM MST MON DEC 15 2014
NO CONCERNS ANTICIPATED THROUGH MID WEEK WITH WIDESPREAD SNOW
COVER...COOL TEMPERATURES...LIGHTER WINDS AND HIGH RELATIVE
HUMIDITIES.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLH
SHORT TERM...MJ
LONG TERM...SAR
AVIATION...SAR
FIRE WEATHER...MJ
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
335 AM EST TUE DEC 16 2014
...WIDESPREAD DENSE FOG SPREADING INLAND ACROSS INTERIOR NORTHEAST
FLORIDA...
.SHORT TERM...WIDESPREAD DENSE FOG CONTINUES TO AFFECT INLAND
PORTIONS OF NE FL WITH THE LEADING EDGE MOVING TO ABOUT THE HIGHWAY
301 CORRIDOR S OF BALDWIN AT 0815Z. MAY NEED TO EXPAND THE ADVISORY
E AND N BASED ON LATEST IR IMAGERY AND HI-RES GUIDANCE AND WILL
CONTINUE TO MONITOR. THINK THE HRRR GUIDANCE IS OVERDONE SHOWING
ABOUT 95% OF THE FORECAST AREA IN DENSE FOG BY 12Z-14Z. NAM12 AND TO
A LESSER EXTENT THE NMM/ARW INDICATE A MORE REALISTIC DEPICTION OF
DENSE FOG/LOW STRATUS AFFECTING NE FL (EXCEPT THE IMMEDIATE ATLC
COASTAL COUNTIES) AND EXTREME SERN GA AT 12Z.
FOR TODAY...FOG SHOULD DISSIPATE MOST LOCATIONS BY 14Z/15Z AS WARMER
SWLY FLOW DEVELOPS AHEAD OF AN APPROACHING COLD FRONT. THE FRONT WAS
LOCATED FROM ERN TN TO EXTREME SE LA AT 08Z. FRONT EXPECTED TO PUSH
THROUGH SE GA IN THE AFTN AND NE FL THIS EVENING. ANTICIPATE ISOLD
TO SCT SHOWER ACTIVITY MOVING INTO SE GA ACCOMPANYING THE FRONT BUT
LITTLE PRECIP AMOUNTS DUE TO FAST MOVEMENT OF SHOWERS AND WEAKLY
FORCED FRONT. NO THUNDER EXPECTED. HIGHS TODAY WILL HINGE ON CLOUD
COVER AS IT INCREASES AHEAD OF FRONT PASSES THROUGH. HIGHS IN
THE LOWER TO MID 70S MOST LOCATIONS. SWLY WINDS AROUND 10-15 MPH
WITH GUSTS POSSIBLY NEAR 20-25 MPH FOR A BRIEF TIME AS MIXING
MAXIMIZES AROUND THE 18Z-23Z TIME FRAME.
TONIGHT...FRONT WILL BE ACROSS COASTAL SE GA TO THE SUWANNEE VALLEY
AREA IN THE EVENING AND MOVE THROUGH REST OF NE FL BY 06Z-08Z. ISOLD
PRECIP POTENTIAL IS INDICATED FROM SUWANNEE VALLEY AREA NEWD TO
BRUNSWICK GA AND SHIFTING SEWD BUT WEAKENING QUICKLY THROUGH THE
EVENING. PARTLY TO MOSTLY CLOUDY IN THE EVENING...BECOMING MOSTLY
CLEAR FROM NW TO SE AFTER MIDNIGHT. MIN TEMPS FALL INTO THE 40S
AGAIN WITH LIGHT NWLY FLOW. COLDEST TEMPS IN THE SE GA AS COOL SFC
HIGH PRES BUILDS IN FROM THE NW.
WED THROUGH THU NIGHT...STACKED HIGH PRESSURE WILL BUILD OVER THE
REGION BRINGING MOSTLY CLEAR TO PARTLY CLOUDY SKIES WITH PASSING
HIGH CLOUDS WED NIGHT THROUGH THURSDAY NIGHT. NEAR SEASONAL TEMPS
EXPECTED WITH HIGHS IN THE 60S AND A DRY WNW FLOW 10 MPH OR LESS.
MIN TEMPS WILL RANGE IN THE UPPER 30S/LOWER 40S INLAND TO MID/UPPER
40S ALONG THE ST JOHNS RIVER BASIN/ATLANTIC COAST WED NIGHT AND
GIVEN PASSING HIGH CLOUDS FROST DEVELOPMENT LIKELY TO BE PATCHY AT
BEST OVER INLAND LOCATIONS. MIN TEMPS WILL BE A BIT WARMER THU NIGHT
WITH VALUES IN LOW/MID 40S INLAND TO UPPER 40S/LOW 50S TOWARD THE
ATLANTIC AS LOW LEVEL WINDS VEER NNE AS A WEAK COASTAL TROUGH/HIGH
PRESSURE WEDGE SCENARIO EDGES SOUTHWARD DOWN THE SE ATLANTIC
SEABOARD. WITH INCREASING TEMPS AND SHALLOW MOISTURE...SOME LATE
NIGHT FOG WILL BE POSSIBLE THU NIGHT.
.LONG TERM...FRI THROUGH TUE...
EXTENDED MODELS (GFS/ECMWF/DGEX) IN GOOD AGREEMENT THROUGH FRI NIGHT
WITH MOSTLY DRY CONDITIONS AND WARMER TEMPS AS WINDS VEER SSW AHEAD
OF AN APPROACHING GULF COAST STORM SYSTEM. COULD SEE A LATE AFTN
SHOWER NEAR THE ATLANTIC COAST AND ALONG THE ALTAMAHA RIVER BASIN
WHERE A COASTAL TROUGH WILL ELONGATE W-E AND MORPH INTO A WARM FRONT
AHEAD OF THE APPROACHING STORM SYSTEM. HIGHS FRI WILL RANGE IN THE
60S INLAND WITH MILD OVERNIGHT LOWS FRI NIGHT IN THE UPPER 40S TO
LOW/MID 50S WITH SOME LATE NIGHT STRATUS/FOG MOVING INLAND FROM THE
GULF.
SAT & SAT NIGHT...EXTENDED GUIDANCE IS IN BETTER AGREEMENT SAT WITH
THE APPROACH OF LOW PRESSURE TREKKING EASTWARD ALONG THE GULF COAST
STATES. THE 00Z ECMWF SLOWED DOWN A BIT AND HAS A WEAKER PARENT
UPPER LEVEL TROUGH COMPARED TO PREVIOUS RUNS AND IS STARTING TO COME
INTO BETTER AGREEMENT WITH THE WEAKER GFS SOLUTION. FOR THIS PACKAGE
ADVERTISED PRE-FRONTAL SHOWERS MOVING ACROSS THE LOCAL FORECAST AREA
MAINLY SAT AFTN WITH 40-50% RAIN CHANCES ACROSS THE ALTAMAHA RIVER
BASIN AND SUWANNEE RIVER VALLEY...DOWN TO 20% SAT AFTN FOR FLAGLER
COUNTY. DYNAMICS/LIFT PUSH OFF TO THE NE OF THE LOCAL AREA SAT NIGHT
LEAVING A STALLING FRONTAL ZONE SAGGING SOUTHWARD OVER THE LOCAL
FORECAST AREA. COULD SEE A FEW LINGERING SHOWERS AND ADVERTISED 20%
AT THIS TIME SAT NIGHT.
SUN-TUE...SUN WILL BE COOLER AND MOSTLY DRY. THE GFS IS FASTER
DEVELOPING AN ISENTROPIC RAINFALL EVENT ACROSS NE FL SUN
NIGHT...WHILE THE ECMWF IS IN BETTER AGREEMENT WITH THE EVENT
TRANSPIRING LATE MON INTO TUE NIGHT...WITH A WIDESPREAD RAINFALL
ACROSS NE FL THROUGH EARLY TUE MORNING AS AN UPPER LEVEL TROUGH
DEEPENS A SFC LOW ALONG THE STALLED FRONTAL ZONE EAST OF THE SE
ATLANTIC COAST EARLY TUE. LOOKS LIKE A COOL AND WET RAINFALL EVENT
WITH THE POTENTIAL FOR DECENT AMOUNTS ALONG AND S OF THE I-10
CORRIDOR. THE WEATHER PREDICTION CENTER HAS AROUND A HALF A INCH
ADVERTISED FOR N FL AND 0.25-0.50" FOR SE GA SUN-TUE WITH LOCALLY
HIGHER AMOUNTS. THIS WOULD BE THE FIRST WIDESPREAD WETTING RAINFALL
EVENT SINCE NOV 25-26TH.
TEMPS WILL RANGE NEAR TO SLIGHTLY BELOW NORMAL WITH NO FREEZES.
HIGHS IN THE UPPER 50S-MID 60S AND LOWS IN THE 40S/LOWER 50S. NO
FREEZING TEMPS EXPECTED AT THIS TIME.
&&
.AVIATION...VLFIR CONDITIONS WILL CONTINUE AT GNV THROUGH 13Z/14Z...
THEN VFR PREVAILS AFTERWARD. SOME UNCERTAINTY ON HOW MUCH OF THIS
FOG WILL AFFECT THE JAX METRO TAFS BUT LIFR POSSIBLE BY 09Z-13Z AS
LEADING EDGE OF ADVECTIVE FOG MOVES FURTHER E TO NE. CONTINUED TO
LEAVE FOG OUT OF SSI TAF AT THIS TIME BASED ON MOST OF THE MODEL
GUIDANCE. VFR CIGS LIKELY FOR A PERIOD OF TIME IN ASSOCD WITH
FRONTAL PASSAGE LATER TODAY AND PROBABILITIES OF MVFR CIGS LOOK TO
BE LESS THAN 30% SO CONFIDENCE IS LOW ATTM. MAIN WINDOW OF POSSIBLE
MVFR CIG WOULD BE FROM ABOUT 22Z TO 06Z. WINDS TODAY SWLY INCREASING
TO NEAR 10-12G20KT AT TIMES...DECREASING AND SHIFTING TO W AND NW
LATER TONIGHT.
&&
.MARINE...SWLY WINDS WILL CONTINUE AROUND 10-15 KT TODAY AND
INCREASE FROM THE W AND THEN NW TONIGHT IN ASSOCD WITH FRONTAL
PASSAGE. HIGH CONFIDENCE ON SCEC CONDS FOR MAINLY THE OUTER WATERS
TONIGHT WITH SEAS OF ABOUT 5 FT AT THE OUTER FRINGES OF THE MARINE
WATERS. WINDS AND SEAS DECREASE WED THROUGH THU AS SFC HIGH PRES
BUILDS IN. CONDITIONS WILL LIKELY WORSEN TO CAUTION LEVELS ONCE
AGAIN FOR THE UPCOMING WEEKEND AS ANOTHER COLD FRONT AFFECTS THE
REGION.
RIP CURRENTS: LOW RISK TODAY THROUGH WEDNESDAY WITH LOW SWELL
HEIGHTS AND OFFSHORE FLOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 72 41 62 38 / 30 10 0 0
SSI 70 46 60 44 / 10 20 0 0
JAX 74 45 64 41 / 10 10 0 0
SGJ 72 49 62 45 / 10 10 0 0
GNV 73 47 67 41 / 10 10 0 0
OCF 73 47 68 41 / 10 10 0 0
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR ALACHUA-
BAKER-BRADFORD-COLUMBIA-GILCHRIST-HAMILTON-MARION-SUWANNEE-
UNION.
GA...NONE.
AM...NONE.
&&
$$
SHASHY/ENYEDI
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
300 AM EST TUE DEC 16 2014
.SHORT TERM /TODAY THROUGH WEDNESDAY/...
ONGOING OVERNIGHT RAIN SHOWERS ACROSS THE AREA WILL CONTINUE THROUGH
LATE MORNING AND EARLY AFTERNOON ACROSS THE CWA AS FRONT PUSHES INTO
THE STATE. INSTABILITY CONTINUES TO BE LIMITED...AND ALTHOUGH
PORTIONS THERE IS A HISTORY OF SOME SMALL AMOUNTS OF MUCAPE AND
LIGHTNING OVER ALABAMA...THUS FAR HAVE NOT HAD ANY LIGHTNING IN THIS
ACTIVITY. AT BEST EXPECT WIDESPREAD 0.25 INCHES OF ADDITIONAL
RAINFALL...WITH HIGHEST AMOUNTS ACROSS NORTHEAST GEORGIA AS THE AREA
OF RAIN TRANSITIONS FARTHER EAST.
ALTHOUGH HRRR PUSHES RAIN SOUTH AND EAST OF THE CWA BY NOON...A FEW
OF THE SHORT TERM HI-RES MODELS CONTINUE TO ADVERTISE RESIDUAL
MOISTURE ACROSS THE AREA...PARTICULARLY FAR NORTH GEORGIA...SO HAVE
KEPT MENTION OF SLIGHT CHANCE POPS UNTIL 21-22Z.
THE PARENT LOW PRESSURE SYSTEM LIFTS OVER THE EASTERN GREAT LAKES
REGION LATE TONIGHT WITH ZONAL FLOW ALOFT RETURNING TO THE REGION
THROUGH THURSDAY MORNING.
HAVE GENERALLY GONE WITH A BLEND FOR TEMPERATURES...WITH NEAR
SEASONAL TEMPERATURES THROUGH THE SHORT TERM.
31
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
BETTER AGREEMENT FOR THE WEEKEND SYSTEM AMONGST THE LONG TERM
MODELS.
SHORT WAVE STILL ON TRACK FOR OVERNIGHT WEDNESDAY INTO THURSDAY
MORNING. ANY PRECIP CHANCES WITH THIS SYSTEM SHOULD BE ON
THURSDAY...WITH ONLY SOME SCATTERED SPRINKLES IN THE NORTHWEST
OVERNIGHT WEDNESDAY. WEDNESDAY MIN TEMPS SHOULD BE WARM ENOUGH NOT
TO CAUSE ANY PTYPE ISSUES EARLY THURSDAY MORNING.
THE NEXT SYSTEM TO IMPACT THE CWFA IS IN THE FRIDAY THROUGH
SATURDAY TIME FRAME. MODELS HAVE COME INTO BETTER AGREEMENT WITH
THE EVOLUTION OF THIS SYSTEM AS COMPARED TO YESTERDAYS RUNS AT
THIS TIME. THE ECMWF HAS A WEAKER 500MB SYSTEM AND THE GFS HAS
NUDGED ITS SURFACE LOW FURTHER SOUTH. ISENTROPICALLY INDUCED
RAINFALL SHOULD BEGIN DURING THE DAY FRIDAY AND SPREAD NORTHEAST
THROUGH THE DAY. CURRENTLY...THE HIGHEST CHANCES FOR PRECIP WILL
BE FRIDAY NIGHT INTO SATURDAY AS LOW PRESSURE TRAVERSES THE AREA.
THE RAIN CHANCES WILL BEGIN TO TAPER OFF EARLY SATURDAY
EVENING. AS FAR AS THE RASN CHANCES FOR THE HIGHER TERRAIN LATE
SATURDAY/EARLY SUNDAY...THE POTENTIAL IS STILL THERE.
HOWEVER...CHANCES STILL REMAIN SMALL. TEMPS IN THE MODELS ARE
WARMER BY A FEW DEGREES AND THE MODELS CAN BE TOO SLOW TO CUT OFF
PRECIP BEHIND A COLD FRONT/LOW PRESSURE. WILL CONTINUE WITH
PERSISTENCE AND KEEP MENTION IN THE FORECAST.
HIGH PRESSURE BRIEFLY BUILDS INTO THE CWFA FOR MONDAY INTO EARLY
TUESDAY WITH THE NEXT SYSTEM IMPACTING THE CWFA TUESDAY NIGHT INTO
WEDNESDAY.
NLISTEMAA
&&
AVIATION...
06Z UPDATE...
LIGHT RAIN SHOWERS CONTINUE ACROSS NORTH GEORGIA THIS
MORNING...AND EXPECT PRECIP TO TAPER OFF ACROSS THE ATL AND CSG
AREAS BY 13Z...AND AHN/MCN BY 15-16Z. CONDITIONS CONTINUE TO
DEGRADE WITH THIS ACTIVITY...WITH IFR EXPECTED BY 11Z...WITH SLOW
IMPROVEMENT THROUGH LATE MORNING. VFR ANTICIPATED BY THE AFTERNOON
WITH DEGRADING CONDITIONS POSSIBLE AGAIN AFTER 06Z WEDNESDAY.
WINDS WILL SHIFT TO THE W-WNW AND INCREASE TO 8-15KT WITH 15-20KT
GUSTS BEHIND THE FRONT.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM ON CIGS THROUGH 13Z.
LOW ON CIGS AFTER 06Z WEDNESDAY.
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
31
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 61 38 58 35 / 30 0 0 0
ATLANTA 59 39 55 37 / 30 0 0 0
BLAIRSVILLE 54 34 53 31 / 30 10 5 5
CARTERSVILLE 57 36 53 34 / 20 0 0 5
COLUMBUS 66 38 60 38 / 30 0 0 0
GAINESVILLE 56 38 55 36 / 30 0 0 5
MACON 67 38 61 35 / 30 0 0 0
ROME 56 36 53 34 / 20 0 5 10
PEACHTREE CITY 61 37 57 35 / 30 0 0 0
VIDALIA 68 42 61 38 / 20 10 0 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...31
LONG TERM....NLISTEMAA
AVIATION...31
AREA FORECAST DISCUSSION
NWS DES MOINES IA
336 AM CST TUE DEC 16 2014
.SHORT TERM /TODAY/...
ISSUED AT 335 AM CST TUE DEC 16 2014
IMMEDIATE CONCERNS ARE PRECIP TRENDS AND WIND. PARENT SHORT WAVE
CONTINUES TO MOVE ACROSS IL WITH ONLY MINIMAL UPSTREAM INFLUENCE
FROM DAKOTAS/ONTARIO WAVE. LATEST RAP ANALYSIS SHOWS LITTLE IN THE
WAY OF OMEGA OR FORCING ACROSS FORECAST AREA...JUST SOME TOKEN MID
LEVEL LIFT ASSOCIATED WITH DAKOTAS/ONTARIO WAVE BARELY GENERATING
LIGHT SNOW/FLURRIES NW AND LOWER BASED H85/H7 OMEGA ALONG THE
DMX/DVN BORDER. NOT ENTIRELY SURE WHAT IS GENERATING THAT OUTSIDE
OF MINOR SEGMENT OF THETA-E ADVECTION DRIVEN MORE BY WRAP AROUND
MOISTURE THAN TEMPS. REGARDLESS...ANY LINGERING UPWARD VERTICAL
MOTION SHOULD WANE OVER THE NEXT SEVERAL HOURS. ANY PRECIP WILL BE
QUITE LIGHT AND TOKEN...BUT WITH TYPE PROBLEMATIC. IR SATELLITE
CLOUD TOP TEMPS AND SOUNDINGS SUGGEST ICE INTRODUCTION WILL VARY
SO FREEZING AND FROZEN HYDROMETEORS ARE BOTH POSSIBLE...AND EVEN
A BRIEF PERIOD OF LIQUID STILL POSSIBLE FAR EAST WITH WARM LAYER
TEMPS STILL 1-3C THERE. NEARLY ALL MODELS ARE UNDERESTIMATING THE
EXTENT OF STRATUS ACROSS THE GREATER MO VALLEY SO HAVE HELD ONTO
CLOUDS FOR MUCH OF THE DAY. LITTLE CONFIDENCE HOW LONG THEY WILL
HOLD ON...BUT CERTAINLY LONGER THAN MODELS SUGGEST.
NO CHANGES TO CURRENT WIND ADVISORY WITH SEVERAL SITES STILL HITTING
SUSTAINED CRITERIA. THEY SHOULD NOT LAST MUCH LONGER HOWEVER WITH
ISALLOBARIC EFFECTS DIMINISHING WITH PRESSURE RISE MAX INTO SERN
IA...AND MAX MSLP GRADIENT EXITING FORECAST AREA. RAP SOUNDINGS
SUGGEST MIXING WILL SUPPORT GUSTS NOT QUITE TO CRITERIA /39KTS/
BUT STILL WELL INTO THE 30S. TEMPS WILL BE FALLING THROUGH MUCH OF
THE DAY. THERE MAY BE A VERY MINOR REBOUND TOWARD MIDDAY BASED ON
RAW TEMP PLUMES...BUT HIGH TEMPS WILL BE AT BEGINNING OF VALID
PERIOD.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 335 AM CST TUE DEC 16 2014
THE SYNOPTIC PATTERN HAS FINALLY CHANGED AND WE WILL SEE COOLER
AND SOMEWHAT MORE ACTIVE WEATHER ACROSS CENTRAL IOWA FOR THE NEXT
SEVEN DAYS AND BEYOND. AT 500 MB...A COMPACT LOW PRESSURE CENTER
MOVING OVER MINNESOTA LATER TODAY WILL SLIDE QUICKLY EASTWARD OVER
THE GREAT LAKES TONIGHT AND WEDNESDAY. AT THE SURFACE...THIS
DEPARTURE WILL BE REFLECTED BY A RIDGE OF HIGH PRESSURE BUILDING
DOWN THE DAKOTAS AND INTO IOWA LATE TONIGHT THROUGH
WEDNESDAY...REINFORCING THE COLDER AIR BUT ALSO PROHIBITING
PRECIPITATION ACROSS THE STATE.
MEANWHILE...A LARGE AND BROAD 500 MB TROUGH WILL BUILD OVER THE
ROCKIES AND WESTERN U.S. ON WEDNESDAY...AND EVENTUALLY PROGRESS
EASTWARD AS A SOMEWHAT CONFUSED AREA OF GENERAL TROUGHINESS
PERSISTING FOR THE REST OF THE WORK WEEK. THE SURFACE RIDGE
DISCUSSED EARLIER WILL STUBBORNLY CLING TO MINNESOTA AND MUCH OF
IOWA DURING THIS TIME EVEN AS ATMOSPHERIC MOISTURE ABOVE A VERY
SHALLOW NEAR SURFACE LAYER INCREASES DRAMATICALLY AROUND THURSDAY.
FORECAST SOUNDINGS ARE UNANIMOUS IN ILLUSTRATING THIS MOISTURE
INCREASE COINCIDENT WITH THE ARRIVAL OF THE BROAD 500 MB
TROUGH...HOWEVER...ANY FORCING ASSOCIATED WITH THIS UPPER FEATURE
WILL BE MODEST AT BEST AND THE RESULT WILL LIKELY BE THICK LAYERED
CLOUDS AND SOME FLURRIES OR LIGHT SNOW AT TIMES. HAVE INCLUDED LOW
POPS IN THE 20 TO 30 RANGE FOR SOME OF THIS PERIOD...BUT NO
SIGNIFICANT IMPACTS ARE ANTICIPATED.
A MORE INTERESTING ATMOSPHERIC FEATURE APPEARS IN THE FORM OF A
LONGWAVE BUT INITIALLY SUBTLE 500 MB TROUGH MOVING ASHORE OVER THE
PACIFIC U.S. COAST AROUND SATURDAY. AS THIS TROUGH SUBSEQUENTLY
MOVES EASTWARD OVER THE ROCKIES AND EMERGES OVER THE HIGH PLAINS
AND MIDWEST IT SHOULD INTENSIFY TO SOME EXTENT...THEN BE
REINFORCED BY TRAILING SHORTWAVES AND CARVE OUT A LARGE CENTRAL
U.S. TROUGH EARLY NEXT WEEK. THERE IS OF COURSE A HIGHER DEGREE OF
UNCERTAINTY AT SUCH A LONG RANGE...HOWEVER...IT DOES APPEAR THAT
THERE WILL BE A DECENT CHANCE FOR SOME KIND OF PRECIPITATION
ACROSS IOWA SOMETIME BETWEEN AROUND SUNDAY NIGHT AND TUESDAY OF
NEXT WEEK. EVEN SO...IT REMAINS TO BE SEEN WHETHER TEMPERATURES
WOULD BE MORE SUPPORTIVE OF RAIN OR SNOW FROM THIS SYSTEM. FOR NOW
HAVE ADVERTISED CHANCE POPS EARLY NEXT WEEK AND IT WILL TAKE SOME
TIME BEFORE THERE IS ANY DEGREE OF CONFIDENCE TO RAISE OR
ELIMINATE THEM.
&&
.AVIATION...16/06Z
ISSUED AT 1136 PM CST MON DEC 15 2014
NORTHWEST WINDS WILL REMAIN GUSTY OVERNIGHT WITH A FEW GUSTS OVER
35 KTS POSSIBLE THROUGH 12Z. RAIN HAS MOVED OVER EASTERN IOWA WITH
SOME WINTRY MIX OVER THE WESTERN PORTION OF THE STATE. MAINLY
NORTHERN SITES WILL HAVE SOME SNOW MIX THOUGH ANY VSBY REDUCTIONS
IN SNOW WILL BE BRIEF. LIFR CIGS ARE BEGINNING TO MOVE EAST.
EXPECT IFR THEN A TRANSITION TO MVFR LATER TONIGHT INTO TUESDAY.
NO CONFIDENCE WHEN THE LARGE STRATUS SHIELD WILL MOVE OUT OF THE
AREA THEREFORE KEPT MVFR STRATUS THROUGH THE PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR AUDUBON-
BOONE-CALHOUN-CARROLL-CERRO GORDO-CRAWFORD-EMMET-FRANKLIN-GREENE-
HAMILTON-HANCOCK-HARDIN-HUMBOLDT-KOSSUTH-PALO ALTO-POCAHONTAS-
SAC-STORY-WEBSTER-WINNEBAGO-WORTH-WRIGHT.
&&
$$
SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...DONAVON
AREA FORECAST DISCUSSION
NWS GOODLAND KS
235 AM MST TUE DEC 16 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 230 AM MST TUE DEC 16 2014
TODAY-TONIGHT...UPPER RIDGE AXIS MOVES OVER THE AREA FROM THE
SOUTHWEST LATE IN THE DAY ALONG WITH INCREASING MID AND UPPER LEVEL
CLOUDINESS. AS THE RIDGE AXIS SLOWLY MOVES EAST TONIGHT (AHEAD OF
APPROACHING UPPER TROUGH) A BRIEF DECREASE IN CLOUDS EXPECTED
THROUGH MIDNIGHT BEFORE CIRRUS MOVES BACK IN FROM THE SOUTHWEST.
WILL HAVE TO WATCH STRATUS CURRENTLY TO OUR NORTH IN NEBRASKA. NAM
BOUNDARY LAYER RH SUGGESTS THESE CLOUDS WILL MOVE IN THIS LATE
THIS MORNING THROUGH AFTERNOON AS WINDS VEER TO THE EAST. DURING
THE OVERNIGHT HOURS THESE CLOUDS EXPAND TOWARD THE SOUTHWEST.
HIGHS AROUND 30 IN SNOWPACK AREAS OF YUMA AND KIT CARSON COUNTIES
WITH LOW TO MID 30S ALONG AND NORTH OF THE INTERSTATE. TO THE
SOUTH UPPER 30S TO AROUND 40. IF THE STRATUS MOVES IN LIKE THE
LATEST NAM SUGGESTS TEMPERATURES WILL BE A BIT COOLER. LOWS 10-15
IN SNOWPACK AREAS AND ALONG THE NE/KS BORDER WITH MID TEENS TO
AROUND 20 ELSEWHERE.
WEDNESDAY-WEDNESDAY NIGHT...DURING THE DAYLIGHT HOURS MODELS
SHOWING AN INCREASE IN MOISTURE/CLOUDS FROM THE SOUTHWEST
ASSOCIATED WITH A WEATHER DISTURBANCE MOVING TOWARD THE FORECAST
AREA FROM THE SOUTHWEST AHEAD OF MAIN UPPER TROUGH. NAM ALSO
SHOWING STRATUS HOLDING TOUGH OVER MUCH OF THE AREA. THERE IS SOME
WEAK UPPER JET SUPPORT ACROSS THE FAR SOUTHEAST/SOUTHERN PARTS OF
THE AREA LATE IN THE DAY. WILL KEEP SOME SLIGHT CHANCE POPS FOR
LIGHT SNOW ACROSS THE FAR EAST AND NORTHWEST WHERE BETTER 850-500
MOISTURE EXISTS. FOR THE NIGHTTIME PERIOD OUR DAYTIME DISTURBANCE
MOVES NORTHEAST AND OUT OF THE AREA BY MIDNIGHT WITH ANOTHER ON
ITS HEELS...MOVING IN FROM THE SOUTHWEST BY EARLY THURSDAY
MORNING. THERE ALSO APPEARS TO BE A WEST TO EAST MOVEMENT IN THE
850-500MB FLOW. WILL CONTINUE WITH SLIGHT CHANCE/LOW CHANCE POPS
FOR PRIMARILY LIGHT SNOW EAST OF THE CO/KS BORDER. MAY SEE A BRIEF
PERIOD OF ICE PELLETS/SLEET ACROSS THE FAR SOUTHEAST/SOUTH PARTS
OF THE AREA WHERE 900-800MB TEMPERATURES APPROACH -1C TO ZERO.
HIGHS IN THE 20S TO AROUND 30 SNOWPACK AREAS AND LOCATIONS ALONG
THE NE/KS BORDER. FURTHER SOUTH 30S AND POSSIBLY A FEW LOW 40S
(TRIBUNE TO LEOTI). LOWS 10-15 SNOWPACK AREAS WITH TEENS TO MID
20S ELSEWHERE.
THURSDAY-THURSDAY NIGHT...MODELS HAVING DIFFICULTY RESOLVING UPPER
PATTERN BUT GENERAL IDEA IS FOR PRECIPITATION (LIGHT SNOW) ASSOCIATED
WITH WEDNESDAY NIGHTS DISTURBANCE MOVES OUT OF THE AREA AROUND
EARLY TO MID AFTERNOON WITH A LULL IN ACTIVITY BY 00Z FRIDAY AS WE
WATCH ANOTHER DISTURBANCE WITH MAIN UPPER TROUGH APPROACH THE
CONTINENTAL DIVIDE. THIS IS FORECAST TO MOVE OVER THE AREA DURING
THE NIGHT BUT NO PRECIPITATION CURRENTLY EXPECTED. HIGHS IN THE
LOW 30S SNOWPACK AREAS WITH MID TO UPPER 30S ELSEWHERE. LOWS MID
TEENS TO LOW 20S.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 1249 AM MST TUE DEC 16 2014
MEDIUM RANGE MODELS HAVE COME INTO BETTER AGREEMENT WITH TRACK OF
SYSTEM MOVING ACROSS THE SOUTHERN PLAINS. GIVEN LATEST DATA AND
TRENDS...AM COMFORTABLE WITH REMOVING POPS FROM INITIAL PORTION
OF THE FORECAST PERIOD. CWA WILL REMAIN IN PROGRESSIVE WESTERLY
FLOW ALOFT THROUGH THE WEEKEND WITH FLOW TRANSITIONING TO
NORTHWESTERLY AS TROUGH DEEPENS OVER THE MIDWEST. ECMWF RATHER
AGGRESSIVE WITH BRINGING PRECIP CHANCES TO WESTERN CWA ON MONDAY
NIGHT...ALTHOUGH GFS HAS SIMILAR PATTERN PRECIP DATA MUCH LOWER.
FOR THE TIME BEING GIVE OPERATIONAL DATA AND OVERALL PATTERN THINK
DRY FORECAST IS WARRANTED AT THIS TIME. WILL SEE A SMALL WARM UP
ACROSS THE AREA THROUGH THE WEEKEND WITH TEMPS CLIMBING INTO THE
MID 40S AND SEASONABLE LOW TEMPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1024 PM MST MON DEC 15 2014
CLEARING HAS OCCURRED OVER MOST OF THE AREA WITH THE EXCEPTION OF
KMCK WHERE STRATUS HAS PERSISTED FOR THE LAST FEW HOURS. TIMING
THE DEPARTURE OF THE STATUS IS PROBLEMATIC. THE HRRR CLEARS IT OUT
AT THE START OF THIS FORECAST WHILE THE NAM FORECAST SOUNDING
KEEPS THE STRATUS TILL AFTER 15Z. FOR NOW WILL GO WITH THE NAM
SINCE SATELLITE IMAGES SHOW IT`S PERSISTENT TREND. OTHERWISE KGLD
WILL BE VFR TONIGHT WITH DECREASING NORTHWEST WIND TURNING LIGHT
AND VARIABLE TUESDAY AFTERNOON AS HIGH PRESSURE BUILDS INTO THE
AREA. KMCK WILL ALSO TURN VFR TUESDAY MORNING AND PERHAPS SLIGHTLY
EARLIER.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...99
LONG TERM...JRM
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
117 AM MST TUE DEC 16 2014
.SHORT TERM...(THIS AFTERNOON THROUGH TUESDAY)
ISSUED AT 1258 PM MST MON DEC 15 2014
SHORT TERM FORECAST FOCUS IS ON THE WINDY CONDITIONS PRODUCING
AREAS OF BLOWING SNOW ACROSS NORTHEAST COLORADO AND THE
DIMINISHING WINDS OVERNIGHT.
NORTH-NORTHWEST WINDS PICKED UP IN THE STEEP PRESSURE GRADIENT OVER
NORTHEAST COLORADO AS THE SURFACE LOW LIFTS OFF TO THE EAST
NORTHEAST TODAY. WITH SUSTAINED WINDS AROUND 30 AND GUSTS UP TO
40...IT HAS BEEN ENOUGH TO BEGIN MOVING THE WET SNOW RECEIVED SUNDAY
NIGHT ACROSS MAINLY NORTHEAST COLORADO...WHERE THE HIGHEST SNOWFALL
AMOUNT REPORTED IN OUR FORECAST AREA WAS 8" IN YUMA COUNTY. EAST-
WEST ROAD CLOSURES AND ACCIDENTS HAVE BEEN REPORTED OVER NORTHEAST
COLORADO WITH DECREASES IN VISIBILITY TO ONE MILE OR LESS WITH
BLOWING SNOW. ROAD CREWS HAD A PRETTY GOOD HANDLE ON THE ROADS THIS
MORNING BEFORE THE WINDS PICKED UP...BUT HAVE BEEN STRUGGLING TO
KEEP ROADS CLEAR MID-DAY THROUGH EARLY AFTERNOON WITH THE AREAS OF
BLOWING SNOW PRODUCING LOCALIZED SNOW PACKED AND SLICK ROADS. IN
ADDITION TO THE AREAS OF BLOWING SNOW...THERE HAS BEEN A BAND OF
LIGHT SNOW FALLING ACROSS THE NORTHWEST PORTION OF OUR FORECAST
AREA. HAVE KEPT THE LIGHT SNOW AND AREAS OF BLOWING SNOW ACROSS
NORTHEAST COLORADO INTACT FOR THE REMAINDER OF THE AFTERNOON AS A
RESULT WITH SNOW AND BLOWING SNOW EXPECTED TO DIMINISH THIS EVENING.
THE LOW PRESSURE AREA OVER THE EASTERN PLAINS WILL BE LIFTING INTO
THE SOUTHERN GREAT LAKES REGION OVERNIGHT WITH A RIDGE MOVING INTO
PLACE OVER THE CENTRAL HIGH PLAINS ON TUESDAY. HIGH PRESSURE WILL
ALSO BE MOVING INTO THE REGION AT THE SURFACE. THE PRESSURE
GRADIENT WILL DECREASE OVERNIGHT AS THE LOW MOVES FURTHER OFF TO
THE EAST...SO GUSTY AND WINDY CONDITIONS WILL DIMINISH OVERNIGHT
WITH LIGHT WINDS EXPECTED DURING THE DAY ON TUESDAY. THERE WILL
BE SOME CLEARING...BUT TEMPERATURES WILL REMAIN VERY SIMILAR ON
TUESDAY AS THEY WERE TODAY...WITH THE NORTHWEST SECTIONS OF THE
FORECAST AREA LIKELY TO BE AFFECTED FOR AT LEAST THE NEXT COUPLE
OF DAYS BY THE SNOWFALL RECEIVED SUNDAY NIGHT ACROSS PORTIONS OF
NORTHEAST COLORADO.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 1249 AM MST TUE DEC 16 2014
MEDIUM RANGE MODELS HAVE COME INTO BETTER AGREEMENT WITH TRACK OF
SYSTEM MOVING ACROSS THE SOUTHERN PLAINS. GIVEN LATEST DATA AND
TRENDS...AM COMFORTABLE WITH REMOVING POPS FROM INITIAL PORTION
OF THE FORECAST PERIOD. CWA WILL REMAIN IN PROGRESSIVE WESTERLY
FLOW ALOFT THROUGH THE WEEKEND WITH FLOW TRANSITIONING TO
NORTHWESTERLY AS TROUGH DEEPENS OVER THE MIDWEST. ECMWF RATHER
AGGRESSIVE WITH BRINGING PRECIP CHANCES TO WESTERN CWA ON MONDAY
NIGHT...ALTHOUGH GFS HAS SIMILAR PATTERN PRECIP DATA MUCH LOWER.
FOR THE TIME BEING GIVE OPERATIONAL DATA AND OVERALL PATTERN THINK
DRY FORECAST IS WARRANTED AT THIS TIME. WILL SEE A SMALL WARM UP
ACROSS THE AREA THROUGH THE WEEKEND WITH TEMPS CLIMBING INTO THE
MID 40S AND SEASONABLE LOW TEMPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1024 PM MST MON DEC 15 2014
CLEARING HAS OCCURRED OVER MOST OF THE AREA WITH THE EXCEPTION OF
KMCK WHERE STRATUS HAS PERSISTED FOR THE LAST FEW HOURS. TIMING
THE DEPARTURE OF THE STATUS IS PROBLEMATIC. THE HRRR CLEARS IT OUT
AT THE START OF THIS FORECAST WHILE THE NAM FORECAST SOUNDING
KEEPS THE STRATUS TILL AFTER 15Z. FOR NOW WILL GO WITH THE NAM
SINCE SATELLITE IMAGES SHOW IT`S PERSISTENT TREND. OTHERWISE KGLD
WILL BE VFR TONIGHT WITH DECREASING NORTHWEST WIND TURNING LIGHT
AND VARIABLE TUESDAY AFTERNOON AS HIGH PRESSURE BUILDS INTO THE
AREA. KMCK WILL ALSO TURN VFR TUESDAY MORNING AND PERHAPS SLIGHTLY
EARLIER.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...LOCKHART
LONG TERM...JRM
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1030 PM MST MON DEC 15 2014
.SHORT TERM...(THIS AFTERNOON THROUGH TUESDAY)
ISSUED AT 1258 PM MST MON DEC 15 2014
SHORT TERM FORECAST FOCUS IS ON THE WINDY CONDITIONS PRODUCING
AREAS OF BLOWING SNOW ACROSS NORTHEAST COLORADO AND THE
DIMINISHING WINDS OVERNIGHT.
NORTH-NORTHWEST WINDS PICKED UP IN THE STEEP PRESSURE GRADIENT OVER
NORTHEAST COLORADO AS THE SURFACE LOW LIFTS OFF TO THE EAST
NORTHEAST TODAY. WITH SUSTAINED WINDS AROUND 30 AND GUSTS UP TO
40...IT HAS BEEN ENOUGH TO BEGIN MOVING THE WET SNOW RECEIVED SUNDAY
NIGHT ACROSS MAINLY NORTHEAST COLORADO...WHERE THE HIGHEST SNOWFALL
AMOUNT REPORTED IN OUR FORECAST AREA WAS 8" IN YUMA COUNTY. EAST-
WEST ROAD CLOSURES AND ACCIDENTS HAVE BEEN REPORTED OVER NORTHEAST
COLORADO WITH DECREASES IN VISIBILITY TO ONE MILE OR LESS WITH
BLOWING SNOW. ROAD CREWS HAD A PRETTY GOOD HANDLE ON THE ROADS THIS
MORNING BEFORE THE WINDS PICKED UP...BUT HAVE BEEN STRUGGLING TO
KEEP ROADS CLEAR MID-DAY THROUGH EARLY AFTERNOON WITH THE AREAS OF
BLOWING SNOW PRODUCING LOCALIZED SNOW PACKED AND SLICK ROADS. IN
ADDITION TO THE AREAS OF BLOWING SNOW...THERE HAS BEEN A BAND OF
LIGHT SNOW FALLING ACROSS THE NORTHWEST PORTION OF OUR FORECAST
AREA. HAVE KEPT THE LIGHT SNOW AND AREAS OF BLOWING SNOW ACROSS
NORTHEAST COLORADO INTACT FOR THE REMAINDER OF THE AFTERNOON AS A
RESULT WITH SNOW AND BLOWING SNOW EXPECTED TO DIMINISH THIS EVENING.
THE LOW PRESSURE AREA OVER THE EASTERN PLAINS WILL BE LIFTING INTO
THE SOUTHERN GREAT LAKES REGION OVERNIGHT WITH A RIDGE MOVING INTO
PLACE OVER THE CENTRAL HIGH PLAINS ON TUESDAY. HIGH PRESSURE WILL
ALSO BE MOVING INTO THE REGION AT THE SURFACE. THE PRESSURE
GRADIENT WILL DECREASE OVERNIGHT AS THE LOW MOVES FURTHER OFF TO
THE EAST...SO GUSTY AND WINDY CONDITIONS WILL DIMINISH OVERNIGHT
WITH LIGHT WINDS EXPECTED DURING THE DAY ON TUESDAY. THERE WILL
BE SOME CLEARING...BUT TEMPERATURES WILL REMAIN VERY SIMILAR ON
TUESDAY AS THEY WERE TODAY...WITH THE NORTHWEST SECTIONS OF THE
FORECAST AREA LIKELY TO BE AFFECTED FOR AT LEAST THE NEXT COUPLE
OF DAYS BY THE SNOWFALL RECEIVED SUNDAY NIGHT ACROSS PORTIONS OF
NORTHEAST COLORADO.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 229 PM MST MON DEC 15 2014
MAIN CONCERN FOR THIS EXTENDED FORECAST RUN IS PRECIPITATION CHANCES
WEDNESDAY EVENING THROUGH FRIDAY. OVERALL...TEMPERATURES SHOULD BE
NEAR TO BELOW NORMAL THROUGH FRIDAY. BEYOND FRIDAY...A RETURN TO
SLIGHTLY ABOVE NORMAL TEMPERATURES APPEARS MORE LIKELY THAN
YESTERDAYS FORECAST GUIDANCE INDICATED.
FOR TOMORROW NIGHT THROUGH WEDNESDAY AFTERNOON...PRECIPITATION FREE
WEATHER IS ANTICIPATED. BAND OF UPPER LEVEL CLOUD COVER PASSES
THROUGH EARLY TOMORROW NIGHT...FOLLOWED BY SOME BRIEF CLEARING THEN
DENSE CLOUDS MOVING IN AGAIN. SOUTH WINDS RETURN...BRINGING A SLIGHT
INCREASE IN MOISTURE BACK TO THE REGION.
WEDNESDAY NIGHT THROUGH FRIDAY IS THE MAIN PERIOD OF CONCERN. AN
UPPER LEVEL DISTURBANCE SPREADS NORTHEAST INTO THE HIGH PLAINS
WEDNESDAY NIGHT. WITH MOISTURE ADVECTION CONTINUING AND ATMOSPHERIC
LIFT INCREASING...EXPECTING TO SEE DEVELOPMENT OF LIGHT
PRECIPITATION. WHAT MAKES THIS EVENT INTERESTING IS THAT SATURATION
IN THE ICE CRYSTAL GROWTH ZONE IS NOT EXPECTED SOUTH OF A LINE FROM
MCCOOK NEBRASKA TO TRIBUNE KANSAS. WHAT DOES THIS MEAN? THIS MEANS
THAT PRECIPITATION WOULD LIKELY FALL IN THE LIQUID FORM. A SHALLOW
LAYER OF MOISTURE NEAR THE SURFACE HIGHLIGHTS A FREEZING DRIZZLE
THREAT DEVELOPING INSTEAD OF SNOW. FREEZING DRIZZLE WOULD BRING A
LARGER IMPACT TO THE AREA WITH ICE DEVELOPING ON THE ROADWAYS DUE TO
TEMPERATURES IN THE LOW 20S. FOR NOW...PLACED SLIGHT CHANCE TO
CHANCE MENTION OF LIGHT SNOW AND FREEZING DRIZZLE INTO THE FORECAST
SOUTH OF THE PREVIOUSLY MENTIONED LINE. NORTH OF THIS LINE...ICE
GROWTH ZONE SATURATION SEEMS MORE LIKELY SO HAVE MAINTAINED A LIGHT
SNOW MENTION. OVERALL...PRECIPITATION AMOUNTS LOOK QUITE LIGHT SO
ANY SNOW THAT FALLS WILL PRODUCE A MINIMAL IMPACT.
BEYOND FRIDAY...MODEL AGREEMENT IS FAIRLY POOR. EXPECTING A WARMING
TREND INTO THE WEEKEND BUT CHANCES OF PRECIPITATION ARE A BIG
QUESTION MARK. ONE THING TO NOTE IS BOTH THE GFS AND EUROPEAN MODELS
ARE INDICATING ANOTHER POSSIBLE COLD BLAST MONDAY OR TUESDAY OF NEXT
WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1024 PM MST MON DEC 15 2014
CLEARING HAS OCCURRED OVER MOST OF THE AREA WITH THE EXCEPTION OF
KMCK WHERE STRATUS HAS PERSISTED FOR THE LAST FEW HOURS. TIMING
THE DEPARTURE OF THE STATUS IS PROBLEMATIC. THE HRRR CLEARS IT OUT
AT THE START OF THIS FORECAST WHILE THE NAM FORECAST SOUNDING
KEEPS THE STRATUS TILL AFTER 15Z. FOR NOW WILL GO WITH THE NAM
SINCE SATELLITE IMAGES SHOW IT`S PERSISTENT TREND. OTHERWISE KGLD
WILL BE VFR TONIGHT WITH DECREASING NORTHWEST WIND TURNING LIGHT
AND VARIABLE TUESDAY AFTERNOON AS HIGH PRESSURE BUILDS INTO THE
AREA. KMCK WILL ALSO TURN VFR TUESDAY MORNING AND PERHAPS SLIGHTLY
EARLIER.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...LOCKHART
LONG TERM...RRH
AVIATION...FS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1124 PM CST Mon Dec 15 2014
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Tuesday)
Issued at 314 PM CST MON DEC 15 2014
Stacked system was centered in northern Missouri early this
afternoon with west to northwest winds bringing cold air in behind
and surface temps 5 to 15F below those of the pre- dawn hours.
Area of precipitation in deformation band on immediate west to
north flank of the system has weakened and exited, but water vapor
imagery supports RAP analysis of a minor wave rotating south into
south central Nebraska with narrow band of cloud top cooling and
light snow reported at CNK.
Recent HRRR and RAP output shows a steady decline in precip this
evening as the system enter the Ohio Valley overnight and this seems
very reasonable with heights rising and steady drying aloft. The
latter brings at least minor difficulty in precip type, but in this
band expect RH deep enough into the ice crystal formation layer for
rain and snow to dominate. Any accumulations should be quite light
and localized. Low cloud looks to be rather persistent tonight into
early Tuesday however with temps in this layer approaching -10C for
flurry possibilities but moisture depth shouldn`t support more than
brief bouts at best. Continued drying should bring some sunshine to
much of Tuesday, but high cloud entering the Rockies just upstream
of the upper ridge axis should increase toward sunset. Went a bit
above MOS averages on low temps tonight with the cloud in place.
.LONG TERM...(Tuesday Night through Monday)
Issued at 314 PM CST MON DEC 15 2014
Shortwave ridging and a dry airmass is expected to keep the
weather quiet for Tuesday night through Wednesday morning. With
some weak cold air advection as high pressure builds in, lows
Wednesday morning are expected to be around 20. Moisture appears
to begin returning north Wednesday. However models show the
shallow cold air holding in place Wednesday, keeping an easterly
surface winds and not mixing the boundary layer very deeply.
Therefore highs are forecast to remain in the middle 30s because
of this as well as increasing cloud cover.
Wednesday night and Thursday continue to look a little tricky with
regard to precip type. Models continue to show a perturbation
moving across the area Wednesday evening and a second one Thursday
morning. The better Q vector convergence and vorticity advection
may pass over southeast KS and the NAM and GFS forecast soundings
suggest there may not be enough saturation in the mid levels for
precip to be all snow. The one solution that continues to produce
a fair amount of QPF (around 2 tenths) Wednesday night is the
ECMWF, but it is difficult to know if there is as much dry air at
mid levels in its solution due to less vertical resolution. In all
it appears there is the potential for a weak progressive wave with
modest vertical motion to affect parts of the area with light
precipitation and have maintained POPs in the 30 to 40 percent
range. Best chances for measurable precip would be across east
central KS where the forcing is likely to be a little stronger.
Given the uncertainty provided by the NAM and GFS forecast
soundings, have introduced some freezing drizzle to the forecast
thinking mid levels may not be saturated and there would be no ice
in the cloud. Right now I would expect a light precip event
possibly affecting motorists late Wednesday night and Thursday
morning.
For Thursday night through Friday night, models seem to be
converging on a southern solution with the upper level jet
remaining over the southern U.S. and a developing surface low
tracking along the gulf coast. Even the 12Z GFS has trended
further south. Because of this, have trended POPS down a little
more for the period. Considered removing them all together but the
GFS still tries to bring energy down from the northwest and kicks
out some light QPF. Therefore held onto some slight chances for
precip.
Temps do not appear to be trending warmer until maybe Monday as
models hang onto the shallow cold airmass through much of the
weekend. By Monday there are signs that some low level return flow
could develop helping to bring some warm air back north. As for
the weather, the models continue to try and figure out this
pattern with split flow and energy coming off the Pacific. With
no obvious forcing progged to affect the forecast area through
Monday, have continued with a dry forecast for the weekend and
into next week.
&&
.AVIATION...(For the 06Z TAFs through 06Z Tuesday Night)
Issued at 1120 PM CST MON DEC 15 2014
MVFR conditions expected to continue through the overnight and
into the late morning hours. As expected the timing of the cloud
departure is in question. Have extended the VFR timing a few hours
later.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...65
LONG TERM...Wolters
AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS JACKSON KY
419 AM EST TUE DEC 16 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 351 AM EST TUE DEC 16 2014
A SURFACE LOW PRESSURE CENTER IS CURRENTLY RIDING JUST NORTH OF THE
OHIO RIVER VALLEY...LOCATED SOMEWHERE FAIRLY CLOSE TO INDIANAPOLIS.
AS THIS LOW CONTINUES TO PROGRESS ENEWARD...IT IS CURRENTLY PULLING
A WARM FRONT FROM SW TO NE ACROSS THE CWA /SHOULD BE THROUGH BY
AROUND 12Z/...AND THEN WILL FOLLOW UP WITH A COLD FRONT PASSING
THROUGH THE CWA FROM WEST TO EAST BETWEEN APPROX 10Z AND 15Z. WITH
EACH OF THESE SYSTEMS...WE ARE CONTINUING TO PICK UP LIGHT SHOWER
ACTIVITY...WITH SCATTERED TO WIDESPREAD RETURNS ACROSS PORTIONS OF
EASTERN KY IN RESPONSE TO THE WARM FRONT...AND ANOTHER AREA JUST
ALONG THE COLD FRONT ACROSS WEST CENTRAL KY. UNFORTUNATELY...MODELS
ARE STILL HAVING A HARD TIME SHOWING A WELL DEFINED PRECIP FORECAST
FOR THIS SYSTEM. LEANED ON A MIXTURE OF RADAR TRENDS...THE HRRR AND
RUC /WHICH SEEMED TO HAVE THE BEST HANDLE ON THE CURRENT
SITUATION/...AND SOME LESSER INFLUENCE FROM A BLEND OF OTHER HI RES
MODELS...TO COME UP WITH THE FORECAST FOR THE PROGRESSION OF THE RAIN
AS WE HEAD THROUGH TODAY. AS SUCH...THE CURRENT RAIN /AND ISOLATED
THUNDER/ OVER CENTRAL KY SHOULD MAKE IT INTO OUR WESTERN CWA WITHIN
THE NEXT FEW HOURS /AROUND 10 TO 11Z/...WHILE CHANCES WILL INCREASE
ALONG MUCH OF THE NE CWA AS THE LOW TRACKS JUST TO OUR NORTH.
DID CONTINUE TO NOTE THAT MOST OF THIS MOISTURE SHOWS UP AS BEING
FAIRLY SHALLOW IN THE FORECAST SOUNDINGS THROUGH TODAY...SO DON/T
EXPECT ANYTHING OTHER THAN LIGHT SHOWERS. ONCE DRY AIR MOVES IN
BEHIND THE COLD FRONT THIS AFTERNOON...EXPECT IT TO ONCE AGAIN TRAP
A LAYER OF LOW LEVEL MOISTURE NEAR THE SURFACE...WHERE IT WILL
LINGER THROUGH AROUND 15Z TOMORROW...LONG AFTER THE INFLUENCE OF THE
LOW PRESSURE SYSTEM. AS SUCH...WHILE SOME OF THIS MOISTURE WILL FALL
AS LIGHT RAIN DURING THE DAY TODAY...IT STANDS TO REASON THAT IT
COULD BE MIXED IN WITH DRIZZLE IN SOME LOCATIONS...AND THEN CHANGE
OVER TO ALL DRIZZLE TONIGHT AS MOISTURE BECOMES INCREASINGLY SHALLOW.
TRIED TO REFLECT THIS IN THE WEATHER GRIDS...WITH A MIXTURE OF
ISOLATED/SLIGHT CHANCE RAIN AND PATCHY DRIZZLE...THEN LIGHT DRIZZLE
LINGERING THROUGH TOMORROW MORNING.
TEMPS WILL RISE SOME THROUGHOUT THE MORNING...WITH SOME PLACES IN
THE EAST POSSIBLY PULLING OUT SOME LOW 50S DUE TO THE WAA BEHIND THE
WARM FRONT...BUT SHOULD GENERALLY FALL FROM WEST TO EAST DURING THE
AFTERNOON AS COLDER AIR FILTERS IN BEHIND THE COLD FRONTAL PASSAGE.
WINDS WILL ALSO CONTINUE TO BE GUSTY AHEAD AND JUST BEHIND THE
FRONT...DYING DOWN AS WE HEAD INTO THE EVENING HOURS. THE PUSH OF
COLDER AIR COULD ALLOW FOR SOME BELOW FREEZING TEMPS BY
OVERNIGHT...NAMELY IN THE HIGHEST TERRAIN IN THE SE. AS SUCH...SOME
FREEZING DRIZZLE IN THESE LOCATIONS CANNOT BE RULED OUT. DID GO AHEAD
AND KEEP A MENTION OF THIS IN THE GRIDS...BUT WILL NEED TO KEEP AN
EYE OUT AS WE HEAD INTO TONIGHT IN CASE ANY FURTHER ACTION NEEDS TO BE
TAKEN. HIGHS WEDNESDAY WILL FALL BELOW SEASONABLE NORMS ONCE
MORE...TOPPING OUT IN THE LOW 40S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 419 AM EST TUE DEC 16 2014
THE MODELS ARE IN GOOD AGREEMENT WITH A PROGRESSIVE LONG WAVE PATTERN
TO HOLD ON THROUGH THE END OF THE WEEK...FOLLOWED BY AMPLIFICATION
INTO EARLY NEXT WEEK. DETAILS WITHIN THE LONG WAVE PATTERN CONTINUE
TO BE CHALLENGING...SO HAVE STUCK FAIRLY CLOSE TO A BLEND OF THE
GUIDANCE...WHILE STEERING THE FORECAST TOWARDS GENERAL MODEL TRENDS
SEEN IN THE PAST FEW DAYS.
THE SOUTHERN STREAM WILL MAINLY BE PROVIDING OUR WEATHER THROUGH THE
PERIOD...AS TROUGHING ACROSS THE SOUTHWEST CONUS GRADUALLY
TRANSLATES EAST. INITIALLY...A DAMPENING SHORT WAVE TROUGH WILL EJECT
OUT OF THE MAIN TROUGH...AFFECTING OUR AREA VERY LATE WEDNESDAY NIGHT
INTO THURSDAY. FORCING WILL BE CONFINED TO THE MID AND UPPER
LEVELS...AND DEEPER MOISTURE CONTINUES TO BE LACKING ACROSS EASTERN
KENTUCKY. AS SUCH...WILL MAINTAIN A SLIGHT CHANCE OF SNOW/RAIN
GENERALLY NEAR AND SOUTH OF THE HAL ROGERS AND HIGHWAY 80 CORRIDORS.
THE MAIN TROUGH AXIS WILL THEN MOVE ACROSS THE GULF COAST STATES AND
EVENTUALLY SWING ACROSS THE SOUTHERN APPALACHIANS BY THE WEEKEND.
THE MODELS HAVE GENERALLY SHOWN A MORE SOUTHERLY TRACK WITH THE
ASSOCIATED SURFACE LOW. THE GFS HAS ALSO TRENDED NOTICEABLY SLOWER
WITH THE PRECIPITATION ONSET. THE THERMAL PROFILES CONTINUE TO DIFFER
QUITE A BIT...WITH THE ECMWF COOLER AND THE GFS WARMER. AS
SUCH...HAVE MAINTAINED A BROAD BRUSH WITH THE RAIN/SNOW POTENTIAL
UNTIL CONFIDENCE INCREASES. PRECIPITATION WILL BEGIN FRIDAY
NIGHT...WITH THE OVERALL BEST CHANCE FOR THE ENTIRE AREA ON SATURDAY.
PRECIPITATION WILL THEN TAPER OFF QUICKLY SATURDAY NIGHT...WITH ONLY
A SMALL CHANCE OF A FEW LINGERING SHOWERS IN THE FAR SOUTHEAST
THROUGH SUNDAY MORNING WITH UPSLOPE FLOW IN PLACE. HIGH PRESSURE WILL
THEN TAKE HOLD INTO EARLY NEXT WEEK...BEFORE A DEEPER TROUGH
APPROACHES FROM THE WEST.
BELOW NORMAL TEMPERATURES WILL REIGN THROUGH THE PERIOD. STUCK FAIRLY
CLOSE TO THE BLENDED GUIDANCE GIVEN THE UNCERTAINTY...HOWEVER DID
ALLOW FOR A MORE DIURNALLY LIMITED TEMPERATURE REGIME DURING THE
PERIODS OF GREATER PRECIPITATION CHANCES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 102 AM EST TUE DEC 16 2014
A COMBINATION WARM FRONT AND COLD FRONT IS CURRENTLY MOVING THROUGH
KY...WITH THE WARM FRONT MAKING A SW TO NE PASS ACROSS EASTERN
KY...AND THE COLD FRONT NOW LOCATED OVER CENTRAL KY. LIGHT RAIN
SHOWERS ARE ONGOING AT MOST OF THE TAF SITES AS A RESULT OF THE
PASSING WARM FRONT. LATEST RADAR TRENDS ARE SHOWING A BRIEF BREAK
BEFORE THE NEXT ROUND OF SHOWERS ASSOCIATED WITH THE COLD FRONT MOVE
INTO THE AREA LATE TONIGHT. WINDS ARE REALLY PICKING UP AHEAD OF THE
COLD FRONT...SO WENT AHEAD AND INCLUDED GUSTY SOUTHERLY WINDS THROUGH
THE FIRST PART OF THE NIGHT...BECOMING MORE WESTERLY BEHIND THE FRONT
AND CONTINUING TO GUST INTO THE DAY TOMORROW. EXPECT CIGS TO CONTINUE
TO FALL TO MVFR...AND THEN EVENTUALLY INTO THE FUEL ALTERNATE
CATEGORY BY LATE TONIGHT. ONCE SHOWERS TAPER OFF BEHIND THE COLD
FRONT TOMORROW...FORECAST SOUNDINGS ARE STILL SUPPORTING THE IDEA FOR
DRIZZLE HANGING AROUND THROUGH TOMORROW NIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JMW
LONG TERM...GEOGERIAN
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
352 AM EST TUE DEC 16 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 351 AM EST TUE DEC 16 2014
A SURFACE LOW PRESSURE CENTER IS CURRENTLY RIDING JUST NORTH OF THE
OHIO RIVER VALLEY...LOCATED SOMEWHERE FAIRLY CLOSE TO INDIANAPOLIS.
AS THIS LOW CONTINUES TO PROGRESS ENEWARD...IT IS CURRENTLY PULLING
A WARM FRONT FROM SW TO NE ACROSS THE CWA /SHOULD BE THROUGH BY
AROUND 12Z/...AND THEN WILL FOLLOW UP WITH A COLD FRONT PASSING
THROUGH THE CWA FROM WEST TO EAST BETWEEN APPROX 10Z AND 15Z. WITH
EACH OF THESE SYSTEMS...WE ARE CONTINUING TO PICK UP LIGHT SHOWER
ACTIVITY...WITH SCATTERED TO WIDESPREAD RETURNS ACROSS PORTIONS OF
EASTERN KY IN RESPONSE TO THE WARM FRONT...AND ANOTHER AREA JUST
ALONG THE COLD FRONT ACROSS WEST CENTRAL KY. UNFORTUNATELY...MODELS
ARE STILL HAVING A HARD TIME SHOWING A WELL DEFINED PRECIP FORECAST
FOR THIS SYSTEM. LEANED ON A MIXTURE OF RADAR TRENDS...THE HRRR AND
RUC /WHICH SEEMED TO HAVE THE BEST HANDLE ON THE CURRENT
SITUATION/...AND SOME LESSER INFLUENCE FROM A BLEND OF OTHER HI RES
MODELS...TO COME UP WITH THE FORECAST FOR THE PROGRESSION OF THE RAIN
AS WE HEAD THROUGH TODAY. AS SUCH...THE CURRENT RAIN /AND ISOLATED
THUNDER/ OVER CENTRAL KY SHOULD MAKE IT INTO OUR WESTERN CWA WITHIN
THE NEXT FEW HOURS /AROUND 10 TO 11Z/...WHILE CHANCES WILL INCREASE
ALONG MUCH OF THE NE CWA AS THE LOW TRACKS JUST TO OUR NORTH.
DID CONTINUE TO NOTE THAT MOST OF THIS MOISTURE SHOWS UP AS BEING
FAIRLY SHALLOW IN THE FORECAST SOUNDINGS THROUGH TODAY...SO DON/T
EXPECT ANYTHING OTHER THAN LIGHT SHOWERS. ONCE DRY AIR MOVES IN
BEHIND THE COLD FRONT THIS AFTERNOON...EXPECT IT TO ONCE AGAIN TRAP
A LAYER OF LOW LEVEL MOISTURE NEAR THE SURFACE...WHERE IT WILL
LINGER THROUGH AROUND 15Z TOMORROW...LONG AFTER THE INFLUENCE OF THE
LOW PRESSURE SYSTEM. AS SUCH...WHILE SOME OF THIS MOISTURE WILL FALL
AS LIGHT RAIN DURING THE DAY TODAY...IT STANDS TO REASON THAT IT
COULD BE MIXED IN WITH DRIZZLE IN SOME LOCATIONS...AND THEN CHANGE
OVER TO ALL DRIZZLE TONIGHT AS MOISTURE BECOMES INCREASINGLY SHALLOW.
TRIED TO REFLECT THIS IN THE WEATHER GRIDS...WITH A MIXTURE OF
ISOLATED/SLIGHT CHANCE RAIN AND PATCHY DRIZZLE...THEN LIGHT DRIZZLE
LINGERING THROUGH TOMORROW MORNING.
TEMPS WILL RISE SOME THROUGHOUT THE MORNING...WITH SOME PLACES IN
THE EAST POSSIBLY PULLING OUT SOME LOW 50S DUE TO THE WAA BEHIND THE
WARM FRONT...BUT SHOULD GENERALLY FALL FROM WEST TO EAST DURING THE
AFTERNOON AS COLDER AIR FILTERS IN BEHIND THE COLD FRONTAL PASSAGE.
WINDS WILL ALSO CONTINUE TO BE GUSTY AHEAD AND JUST BEHIND THE
FRONT...DYING DOWN AS WE HEAD INTO THE EVENING HOURS. THE PUSH OF
COLDER AIR COULD ALLOW FOR SOME BELOW FREEZING TEMPS BY
OVERNIGHT...NAMELY IN THE HIGHEST TERRAIN IN THE SE. AS SUCH...SOME
FREEZING DRIZZLE IN THESE LOCATIONS CANNOT BE RULED OUT. DID GO AHEAD
AND KEEP A MENTION OF THIS IN THE GRIDS...BUT WILL NEED TO KEEP AN
EYE OUT AS WE HEAD INTO TONIGHT IN CASE ANY FURTHER ACTION NEED TO BE
TAKEN. HIGHS WEDNESDAY WILL FALL BELOW SEASONABLE NORMS ONCE
MORE...TOPPING OUT IN THE LOW 40S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 426 PM EST MON DEC 15 2014
RESIDUAL MOISTURE IN NW FLOW COLD AIR ADVECTION WILL BRING CLOUDS AS
THE PERIOD STARTS...WITH SOME LINGERING DRIZZLE POSSIBLE FOR MUCH OF
THE AREA. THERE IS SOME POTENTIAL FOR FREEZING DRIZZLE AT HIGHER
ELEVATIONS IN THE SE PART OF THE STATE. ANY DRIZZLE WILL END AND
CLOUDS SHOULD BREAK UP DURING THE DAY AS SURFACE RIDGING BUILDS IN
FROM THE WEST.
THE RETURN TO FAIR WEATHER COULD BE SHORT-LIVED. MOISTURE OFF THE
GULF WILL BE ISENTROPICALLY LIFTED OVER THE SOUTHERN PLAINS AND GET
CAUGHT IN THE MID/UPPER LEVEL FLOW WITH A WEAK SOUTHERN STREAM
IMPULSE MOVING THROUGH. 12Z MODEL BLEND SUGGESTS LOW POPS FOR LIGHT
PRECIP WITH THIS SYSTEM IN OUR SOUTHERN COUNTIES ON THURSDAY.
TEMPERATURES LOOK MARGINAL FOR RAIN/SNOW AND HAVE INCLUDED BOTH.
ONCE THE THURSDAY SYSTEM LEAVES...THERE IS ANOTHER BREAK FOR ABOUT 24
HOURS BEFORE THE NEXT ONE HAS TO BE DEALT WITH. A MID/UPPER LEVEL
TROUGH CURRENTLY OFFSHORE OF THE WEST COAST WILL MOVE INLAND AND
TRACK ACROSS THE SOUTHWEST CONUS. AS IT EMERGES OVER THE SOUTHERN
PLAINS...SURFACE LOW PRESSURE SHOULD DEVELOP ALONG THE WESTERN GULF
COAST. AS THIS SYSTEM HEADS EAST...ITS EVENTUAL EVOLUTION WILL
DETERMINE OUR WEEKEND WEATHER. MODELS STILL HAVE NOT COME TO A GOOD
CONSENSUS ON WHAT WILL HAPPEN. THE LATEST TREND IN THE 12Z RUNS IS FOR
A TRACK FURTHER SOUTH AND LIGHTER PRECIP IN OUR AREA. CONSIDERING HOW
POORLY THEY HAVE BEEN HANDLING IT SO FAR...IT WOULD BE GOOD TO SEE AT
LEAST ANOTHER FULL SET OF GUIDANCE BEFORE WHOLE-HEARTEDLY JUMPING ON
THAT BANDWAGON. HAVE MADE A MODEST DRAWBACK ON POPS...WHILE
MAINTAINING THE POTENTIAL FOR BOTH SNOW AND RAIN. GREATEST POPS ARE
LATE FRIDAY NIGHT INTO SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 102 AM EST TUE DEC 16 2014
A COMBINATION WARM FRONT AND COLD FRONT IS CURRENTLY MOVING THROUGH
KY...WITH THE WARM FRONT MAKING A SW TO NE PASS ACROSS EASTERN
KY...AND THE COLD FRONT NOW LOCATED OVER CENTRAL KY. LIGHT RAIN
SHOWERS ARE ONGOING AT MOST OF THE TAF SITES AS A RESULT OF THE
PASSING WARM FRONT. LATEST RADAR TRENDS ARE SHOWING A BRIEF BREAK
BEFORE THE NEXT ROUND OF SHOWERS ASSOCIATED WITH THE COLD FRONT MOVE
INTO THE AREA LATE TONIGHT. WINDS ARE REALLY PICKING UP AHEAD OF THE
COLD FRONT...SO WENT AHEAD AND INCLUDED GUSTY SOUTHERLY WINDS THROUGH
THE FIRST PART OF THE NIGHT...BECOMING MORE WESTERLY BEHIND THE FRONT
AND CONTINUING TO GUST INTO THE DAY TOMORROW. EXPECT CIGS TO CONTINUE
TO FALL TO MVFR...AND THEN EVENTUALLY INTO THE FUEL ALTERNATE
CATEGORY BY LATE TONIGHT. ONCE SHOWERS TAPER OFF BEHIND THE COLD
FRONT TOMORROW...FORECAST SOUNDINGS ARE STILL SUPPORTING THE IDEA FOR
DRIZZLE HANGING AROUND THROUGH TOMORROW NIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JMW
LONG TERM...HAL
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
345 AM CST TUE DEC 16 2014
.SHORT TERM...
COLD FRONT IS CURRENTLY LOCATED ALONG A GULFPORT TO HOUMA LINE AND
MOVING EASTWARD. THERE/S NOT A WHOLE LOT OF RAINFALL ALONG THE
BOUNDARY WITH LOCATIONS SEEING AT MOST ABOUT A QUARTER OF AN INCH
BUT MORE COMMONLY LESS THAN ONE TENTH. WINDS HAVE GUSTED TO AS HIGH
AS 30 KNOTS BUT THOSE CONDITIONS WILL BE QUITE BRIEF AND RIGHT ALONG
THE LINE OF SHOWERS. TEMPERATURES ARE GENERALLY DROPPING ABOUT 6
DEGREES AS THE FRONT PASSES BUT THE MORE SIGNIFICANT CHANGE IS
DEWPOINTS FALLING AROUND 10 DEGREES. THE HRRR QPF OUTPUT IS SPOT ON
FOR INITIATION AND HAS BEEN DOING WELL FOR THE LAST FEW HOURS. GOING
OFF THAT...WHATS LEFT OF THIS LINE OF SHOWERS MOVING THROUGH SHOULD
BE PUSHING OFFSHORE BY SUNRISE AND OUT OF THE ENTIRE CWA BY NOON.
TODAY/S HIGHS WILL BE A FIGHT BETWEEN INSOLATION AND COOL AIR MOVING
IN TODAY AS SURFACE HIGH PRESSURE BUILDS IN. TEMPERATURES WILL DROP
ABOUT 10 TO 15 DEGREES FROM MONDAY OR LOWER TO UPPER 60S WHICH IS
RIGHT ABOUT NORMAL FOR THIS TIME OF YEAR. MOVING INTO THE OVERNIGHT
HOURS...THE COMBINATION OF LIGHT WINDS AND CLEAR SKIES SHOULD ALLOW
FOR GOOD RADIATIONAL COOLING. AM AT OR SLIGHTLY BELOW GUIDANCE ON
FCST LOWS.
.LONG TERM...
A BRIEF COOLING TREND WILL PERSIST ON WEDNESDAY AS HIGH PRESSURE
BUILDING IN FROM THE NORTH CONTINUES TO BRING IN COLDER AND DRIER
AIR. THIS WILL BRING HIGHS DOWN A FEW DEGREES MORE FROM TUESDAY TO
NEAR 60 ON WEDNESDAY. THIS COOL DOWN WILL BE BRIEF AS THE SFC RIDGE
QUICKLY SLIDES EAST AND SOUTHEASTERLY FLOW & MOISTURE BEGINS TO
RETURN.
THE NEXT EVENT TO IMPACT THE AREA COMES IN LATE THIS WEEK. MODELS
SHOW A WEAKER UPPER LEVEL TROUGH SWINGING ACROSS THE BAJA OF
CALIFORNIA ON WEDNESDAY. A WEAKER PORTION OF THIS TROUGH WILL SHOOT
NORTHEAST ACROSS THE CENTRAL PLAINS WEDNESDAY NIGHT. AN ASSOCIATED
CONVERGENCE ZONE WILL DEVELOP ACROSS EAST TEXAS AND NORTHERN
LOUISIANA AS A RESULT. A FEW SHOWERS ALONG THIS BOUNDARY COULD NUDGE
INTO THE NORTHWESTERN PORTIONS OF THE CWA THURSDAY. THE MAIN PIECE
OF THE UPPER TROUGH TO THE WEST WILL BEGIN PROGRESSING EAST ACROSS
NEW MEXICO AND TEXAS ON FRIDAY. AS SURFACE LOW WILL DEVELOP JUST
AHEAD OF THIS UPPER LOW AND TRACK ACROSS THE CWA FRIDAY INTO FRIDAY
NIGHT. THIS WILL BE THE MAIN FOCUS FOR SHOWERS AND POSSIBLY A FEW
THUNDERSTORMS. INSTABILITY DOES APPEAR TO BE HIGHER CLOSER TO THE
COAST AND THUS COASTAL PARISHES AND COUNTIES IS WHERE THE STRONGER
ACTIVITY WILL BE. DRYING WILL THEN TAKE PLACE SATURDAY...ESPECIALLY
IN THE AFTERNOON HOURS WITH MUCH COOLER CONDITIONS SATURDAY AND
SUNDAY. HIGHS WILL STRUGGLE TO REACH 60 ON SATURDAY AND EVEN LESS
LIKELY ON SUNDAY. LOWS WILL BE JUST AS COOL AS WELL WITH MINS IN THE
UPPER 30S TO MID 40S.
MEFFER
&&
.AVIATION...COLD FRONT AND ASSOCIATED LINE
SHRA HAVE ALREADY MOVED THROUGH THE MAJORITY OF THE TERMINALS AND
VFR CONDITIONS ARE SETTING RIGHT BACK IN. WINDS WILL REMAIN OUT OF
THE NW/NNW THROUGH TODAY BUT SHOULD QUICKLY RELAX AFTER 3Z
TONIGHT...IN FACT THE SOUTHSHORE TERMINALS WILL LIKELY SEE WINDS
DROP SIGNIFICANTLY TONIGHT EVEN AFTER A COLD FRONTAL PASSAGE. OTHER
THAN THAT EVERYTHING SHOULD REMAIN QUIET. /CAB/
&&
.MARINE...WINDS BEHIND THE COLD FRONT THIS MORNING WILL REMAIN
ELEVATED FOR A SHORT WHILE BUT EXPECT THEM TO DROP BELOW SCS
HEADLINE CRITERIA BEFORE MIDDAY. CAA IS JUST NOT THAT STRONG BEHIND
THE FRONT COMBINE THAT WITH THE ASSOCIATED SFC LOW BEING RATHER FAR
NORTH AND HIGH PRESSURE QUICKLY BUILDING BACK INTO THE REGION
OFFSHORE WINDS WILL LIKELY BE 10-15 KTS TONIGHT IN THE OUTER WATERS.
HIGH PRESSURE SHOULD KEEP THINGS RELATIVELY QUIET THROUGH THU NIGHT
AND THEN DEPENDING ON THE EVENTUAL TRACK OF THE NEXT SFC LOW ONSHORE
WINDS LOOK LIKE THEY SHOULD BEGIN TO RAMP BACK UP FRI WITH SCY
CONDITIONS POSSIBLE FRI THROUGH SAT. /CAB/
&&
.DECISION SUPPORT...
DSS CODE...GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 62 34 58 42 / 0 0 0 10
BTR 64 37 61 44 / 0 0 0 10
ASD 66 35 61 42 / 10 0 0 0
MSY 65 44 60 48 / 10 0 0 0
GPT 65 38 59 44 / 10 0 0 0
PQL 69 35 61 39 / 20 0 0 0
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
932 PM MST MON DEC 15 2014
.UPDATE...
AREAS WHERE MOST MOISTURE FELL STILL UNDER THE INFLUENCE OF
STRATUS AND THIS IS DELAYING FOG DEVELOPMENT. HRRR SHOWS FOG
DEVELOPING BUT HANGING OVER THE LOWER ELEVATIONS AND NOT IMPACTING
KBIL UNTIL 09Z. THIS IS SUPPORTED BY MODELS SHOWING WINDS DYING
DOWN AT THAT POINT WHICH SHOULD ALLOW FOG LAYER TO DEEPEN. NO
UPDATES AS CURRENT FORECAST LOOKS GOOD. BORSUM
&&
.SHORT TERM...VALID FOR TUE AND WED...
WEAK UPPER LEVEL RIDGING MOVING ACROSS THE AREA TONIGHT. THIS
WILL KEEP DEFORMATION ZONE NORTH OF OUR AREA AND LITTLE CHANCE OF
PRECIPITATION OVERNIGHT. LOW LEVELS WILL REMAIN SATURATED
OVERNIGHT AND FOG WILL BE POSSIBLE FROM BIG TIMBER EAST OVER
NIGHT. A FEW AREAS MAY SEE DENSE FOG BUT THESE AREAS SHOULD BE
ISOLATED AND WILL NOT ISSUE ANY ADVISORY AT THIS TIME. UPPER RIDGE
WILL SHIFT EASTWARD ON TUESDAY WHICH WILL ALLOW PACIFIC ENERGY TO
MOVE IN FROM THE SOUTHWEST. THIS WILL BRING A FEW MOUNTAINS SNOW
SHOWERS. MODELS ARE ALL CONSISTENT IN DEVELOPING AN UPPER LOW
CIRCULATION OVER MONTANA TUESDAY NIGHT AND WEDNESDAY. BOTH
GFS/ECMWF BRING WEAK QG FORCING ACROSS THE AREA AND HAVE INCREASED
POPS OVER OUR WESTERN ZONES FOR THIS TIME PERIOD. MOISTURE WILL
ADVECT BACK INTO THE AREA BUT LOW LEVEL FORCING IS VERY MINIMAL
WITH WEAK WIND FIELD ALOFT. SNOWFALL FROM THIS SYSTEM WILL BE
VERY LIGHT. TEMPERATURES REMAINING NEAR OR SLIGHTLY BELOW SEASONAL
NORMALS FOR TONIGHT THROUGH WEDNESDAY NIGHT WITH LITTLE MIXING TO
TAKE PLACE. RICHMOND
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
WEAK FLOW STILL DOMINATES MUCH OF THE EXTENDED...AND WITH THAT
CONTINUED UNCERTAINTY IN THE MODELS. AS A WEAK WAVE MOVES THROUGH
THE AREA THURSDAY...PRECIP CHANCES REMAIN IN THE WESTERN
MOUNTAINS. FRIDAY A WEAK RIDGE MOVES IN AND THE AREA WILL DRY OUT.
AS WE GO THROUGH THE DAY SUNDAY...THE FLOW ALOFT WILL INCREASE AS
A JET MOVES INTO THE PACIFIC NORTH WEST. OVER THE NEXT COUPLE OF
DAYS...THERE IS SOME DIFFERENCE IN THE MODELS IN HOW THEY HANDLE
EVOLUTION OF THE JET...WHICH WILL BE SOMETHING TO WATCH. THE
PRESSURE GRADIENT WILL START TO TIGHTEN UP AS A SURFACE LOW
DEVELOPS IN SOUTHERN CANADA. SUNDAY NIGHT INTO MONDAY WILL BE
WINDY FROM THE FOOTHILLS OUT TO AROUND BILLINGS.
THE MODELS CONTINUE TO SHOW A FRONT PUSHING THROUGH THE AREA
DURING THE DAY MONDAY. THE LATEST GUIDANCE...ESPECIALLY THE
GFS...HAS TRENDED TEMPERATURES WARMER MONDAY AHEAD OF THE
FRONT...DUE TO COMPRESSIONAL WARMING. HAVE CONTINUED THE CHANCE
POPS ACROSS THE AREA MONDAY AS THE FRONT MOVES THROUGH THE AREA.
TEMPERATURES WILL IN GENERAL BE ABOVE NORMAL. REIMER
&&
.AVIATION...
FOG HAS DEVELOPED IN BILLINGS...AND PATCHY FOG IS POSSIBLE ACROSS
MOST OF THE AREA OVERNIGHT...WITH THE EXCEPTION OF LIVINGSTON.
FOG WILL RESULT IN LOCALIZED IFR OR LOWER CONDITIONS. OTHERWISE
VFR CONDITIONS WILL PREVAIL. OCCASIONAL MOUNTAIN OBSCURATIONS ARE
EXPECTED THROUGHOUT THE NIGHT. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
TUE WED THU FRI SAT SUN MON
-----------------------------------------------------------
BIL 014/028 019/036 022/038 023/038 024/042 024/043 032/047
00/B 11/B 11/B 10/U 01/N 11/N 13/W
LVM 015/034 023/042 024/041 023/041 025/043 024/042 033/046
01/B 22/W 11/B 11/U 11/N 12/W 23/W
HDN 008/029 014/034 014/037 017/037 016/040 018/041 026/045
00/B 12/J 11/B 10/U 01/B 11/B 13/W
MLS 012/027 015/030 017/037 020/037 018/038 021/040 028/044
00/B 11/B 11/B 10/U 01/U 11/B 12/W
4BQ 012/030 016/034 017/039 018/040 017/041 020/042 026/046
00/B 12/J 11/B 10/U 00/U 11/B 13/W
BHK 012/024 011/028 015/035 019/038 018/037 020/039 025/043
00/B 01/B 11/B 11/U 00/U 11/B 13/W
SHR 009/030 016/036 015/037 016/038 017/040 018/041 024/044
00/B 11/B 11/B 11/U 01/U 11/B 12/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
334 AM CST TUE DEC 16 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CST TUE DEC 16 2014
WITH LITTLE TO NO RISK OF PRECIPITATION DURING THESE NEXT 24
HOURS...THE MAIN FORECAST CHALLENGE CENTERS AROUND
TEMPERATURES/SKY COVER...AND THE OBVIOUS AFFECT ONE HAS ON THE
OTHER...ALONG WITH ANY INFLUENCE ON TEMPS FROM SNOW COVER IN
NORTHERN/WESTERN COUNTIES.
STARTING OFF WITH THE HERE AND NOW AS OF 0900Z/3AM...ITS
CERTAINLY BEEN A MUCH QUIETER NIGHT THAN THE PRECEDING ONE...AS
ANY MEASURABLE PRECIP ASSOCIATED WITH THE DEPARTING LOW PRESSURE
SYSTEM IS NOW WELL-EAST INTO EASTERN IA. IN THE MID AND UPPER
LEVELS...WATER VAPOR SATELLITE AND SHORT TERM MODEL DATA CLEARLY
DEPICT THE CENTER OF THE CLOSED 500 MILLIBAR LOW OVER NORTHERN
IL...WHILE UPSTREAM FROM IT...THE LEADING EDGE OF A BROAD
SHORTWAVE RIDGE AND ASSOCIATED HEIGHT RISES IS STARTING TO
OVERSPREAD THE LOCAL AREA...WITH THE RIDGE AXIS GENERALLY ALIGNED
NORTH-SOUTH THROUGH THE ROCKIES. FARTHER WEST...THE NEXT BROAD
TROUGH IS IN THE PROCESS OF COMING ONSHORE THE WEST COAST...WHICH
WILL PROVIDE PLENTY OF CHALLENGES LOCALLY IN THE DAYS 2-4 PERIOD
AS COVERED IN THE LONG TERM SECTION BELOW. AT THE
SURFACE...CERTAINLY THE BIG STORY OVERNIGHT HAS BEEN CONTINUED
FAIRLY STRONG NORTHWEST WINDS...ALTHOUGH THEY ARE ON A SLOW-BUT-
STEADY DOWNWARD TREND AS THE PRESSURE GRADIENT STARTS TO RELAX IN
THE WAKE OF THE DEPARTING 1004MB LOW OVER NORTHERN IL...AND AS A
BROAD RIDGE AXIS CENTERED AT AROUND 1030MB OVER THE DAKOTAS/SOUTH
CENTRAL CANADA STARTS TO EXERT INCREASING INFLUENCE LOCALLY. AS OF
THIS TIME HOWEVER...SUSTAINED SPEEDS OF AT LEAST 20-25 MPH ARE
HANGING ON IN EASTERN ZONES WITH HIGHER GUSTS...AND MORE SO 15-20
MPH IN WESTERN ZONES. EARLIER IN THE NIGHT...THERE WERE LAW
ENFORCEMENT REPORTS OF SOME DICEY TRAVEL CONDITIONS DUE TO SLICK
ROADS/LIMITED BLOWING SNOW IN/NEAR THE FAR NORTHERN CWA COUNTIES
OF VALLEY/GREELEY...BUT FORTUNATELY THE DECREASING SPEEDS SHOULD
AT LEAST IMPROVE THIS SITUATION SLIGHTLY. ACTUALLY THE NUMBER ONE
VERY SHORT-TERM CHALLENGE IS SKY COVER...AS WHILE THE MAJORITY OF
THE CWA REMAINS UNDER A BROAD LOW STRATUS DECK AROUND 1500 FT
AGL...AN AREA OF CLEARING HAS RECENTLY BROKEN OUT OVER SOUTHWEST
COUNTIES. TEMP-WISE...AS SUSPECTED 24 HOURS THE COMBO OF CLOUDS
AND/OR BRISK BREEZES IS HOLDING UP THINGS FAIRLY WELL...AND
ALTHOUGH SOME DROPS COULD YET OCCUR AROUND SUNRISE...THINK THE
MAJORITY OF THE CWA SHOULD HOLD UP NO COLDER THAN THE 17-20 RANGE.
LOOKING FORWARD INTO THE DAYTIME FORECAST AND STARTING WITH THE
MID-UPPER LEVEL SCENE...THE AFOREMENTIONED BROAD RIDGE AXIS
OVERSPREADS THE CENTRAL PLAINS BUT FLATTENS A BIT AS IT DOES SO.
AT THE SURFACE...CERTAINLY THE MOST NOTICEABLE CHANGE FROM MONDAY
WILL BE THE DECREASING NORTHWESTERLY WINDS...AS THE PRESSURE
GRADIENT CONTINUES EASING UP AS THE SOUTHERN EDGE OF THE RIDGE
AXIS CENTERED TO THE NORTH CONTINUES PUSHING SOUTHWARD INTO THE
CENTRAL PLAINS IN THE WAKE OF THE DEPARTING LOW THAT REACHES THE
LAKE HURON AREA BY SUNSET. SPEED-WISE...BY MID-DAY SUSTAINED
SPEEDS SHOULD AVERAGE ONLY AROUND 15 MPH IN EASTERN ZONES...AND NO
MORE THAN 10-15 MPH IN WESTERN COUNTIES...AND BY NIGHTFALL THE
ENTIRE CWA SHOULD BE DOWN TO ONLY 5-10 MPH. AS MENTIONED...SKY
COVER/TEMPS ARE REALLY THE FORECAST CHALLENGE OF THE DAY. MODELS
SUCH AS THE 06Z NAM CLEARLY HOLD ONTO PLENTIFUL LOW LEVEL CLOUD
COVER THROUGH THE ENTIRE DAY WITHIN ROUGHLY THE NORTHEAST 1/2 OF
THE CWA...BUT DO SHOW AT LEAST SEVERAL HOURS OF MOSTLY SUNNY-
PARTLY CLOUDY POTENTIAL OVER MUCH OF THE SOUTHWESTERN 1/2.
ALTHOUGH THE LATEST HRRR LOW LEVEL SKY COVER PRODUCT SPORTS A
SIMILAR THEME...IT SUGGESTS THAT SOME OF THE CLEARING THAT OCCURS
COULD FILL BACK IN AS MORE CLOUDS ADVECT IN FROM THE NORTH-
NORTHWEST. EVEN IF PARTS OF THE CWA DO ENJOY APPRECIABLE CLEARING
AND WELCOMED SUNSHINE THROUGH MUCH OF THE DAY...ESPECIALLY THE
LATER AFTERNOON HOURS SHOULD BRING A GRADUAL INCREASE IN MID-HIGH
CLOUDS STREAMING IN FROM THE WEST IN ASSOCIATION WITH A WEAK/LOW
AMPLITUDE SHORTWAVE TROUGH WELL OUT AHEAD OF THE LARGER WESTERN
TROUGH. SO IN SUMMARY...GENERALLY EXPECT MOSTLY CLOUDY SKIES
NORTHEAST 1/2 TODAY...AND MOSTLY SUNNY-PARTLY CLOUDY
SOUTHWEST ESPECIALLY KS ZONES...BUT SOME VARIATION FROM THIS IS
LIKELY AS WELL. OBVIOUSLY THIS TRICKY SKY COVER WILL WORK IN
CONCERT WITH THE GENERALLY 1-3 INCHES OF SNOW COVER IN PLACE OVER
SEVERAL NORTHERN/WESTERN COUNTIES TO MAKE HIGH TEMPS A BIT
CHALLENGING AS WELL. WITH RAW MET/MAV GUIDANCE LOOKING A BIT TOO
COOL ESPECIALLY IN SOUTHERN ZONES...OPTED TO MAKE ONLY MINOR
TWEAKS TO PREVIOUS FORECAST BY TRYING TO STRIKE SOME KIND OF
BALANCE BETWEEN VARIABLE SNOW COVER AND SKY COVER. THE NET
RESULT...ALTHOUGH NOT OVERLY CONFIDENT...YIELDS ONLY MID-UPPER 20S
WITHIN MANY NORTHERN/WESTERN NEB COUNTIES...MAINLY LOW 30S IN
EASTERN/SOUTHERN NEB ZONES...AND GENERALLY MID 30S IN KS ZONES.
TURNING TO THIS EVENING/TONIGHT...THE MID-UPPER LEVEL PICTURE
FEATURES THE AFOREMENTIONED/RATHER SUBTLE LEAD SHORTWAVE
DISTURBANCE CROSSING OVER THE LOCAL AREA...WHILE MORE ENERGETIC
WAVES REMAIN WELL OFF TO THE WEST-SOUTHWEST. MEANWHILE AT THE
SURFACE...THE RIDGE AXIS WILL SLOWLY EDGE EASTWARD. ALTHOUGH WIND
SPEEDS SHOULD REMAIN LIGHT GENERALLY WELL-UNDER 10 MPH THROUGH THE
ENTIRE NIGHT...DIRECTION WILL GRADUALLY TRANSITION FROM NORTHERLY
TO EASTERLY. DESPITE THE FAIRLY WEAK NATURE OF THE PASSING
DISTURBANCE...MODEL RELATIVE HUMIDITY PROGS DEPICT A FAIRLY DECENT
COVERAGE OF MID-HIGH CLOUD COVER THROUGH THE NIGHT...AND HAVE THE
ENTIRE CWA IN PARTLY TO MOSTLY CLOUDY SKY COVER CATEGORY. WHILE
CONFIDENCE IS FAIRLY HIGH IN A PRECIP-FREE NIGHT (ESPECIALLY
MEASURABLE) AND THE OFFICIAL FORECAST REFLECTS SUCH...WOULD NOT BE
TOTALLY SURPRISED TO SEE A WEST-EAST ORIENTED BAND OF FLURRIES
TRY TO GET GOING LATE IN THE NIGHT MAINLY OVER/NEAR THE NORTHERN
CWA IN RESPONSE TO SOME FAIRLY MODEST ISENTROPIC LIFT/FRONTOGENESIS
FOCUSED IN THE ENTRANCE REGION OF A DEPARTING UPPER JET STREAK.
DESPITE THE LIGHT BREEZES...THE EXPECTED FAIRLY HIGH SKY COVER
SHOULD KEEP TEMPS FROM REALLY FALLING OFF...AND AS A RESULT KEPT
LOW TEMPS GENERALLY 2-4 DEGREES ABOVE A 00Z MET/MAV GUIDANCE
BLEND...AIMING MOST OF THE CWA INTO THE 15-20 RANGE...EXCEPT FOR
COLDER READINGS AROUND 10 FAR NORTH. LASTLY...DESPITE FAIRLY HIGH
VALUES OF FORECAST LOW-LEVEL RELATIVE HUMIDITY...CONFIDENCE WAS
NOT SUFFICIENT ENOUGH IN FOG FORMATION TO INTRODUCE EVEN A PATCHY
MENTION FOR LATE TONIGHT...ALTHOUGH 03Z SREF/06Z NAM VISIBILITY
PROGS SUGGEST THAT MAYBE LOCALIZED POCKETS OF MAINLY THE FAR
WESTERN CWA COULD BEAR WATCHING FOR THIS...ESPECIALLY IF ENOUGH
SNOW MANAGES TO MELT TODAY TO ENHANCE LOW-LEVEL MOISTURE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 334 AM CST TUE DEC 16 2014
THE LONG TERM DISCUSSION WILL BE ADDED HERE WITHIN THE NEXT HOUR
OR SO...STAY TUNED.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1208 AM CST TUE DEC 16 2014
ALTHOUGH CONFIDENCE IS RATHER HIGH IN BOTH WIND SPEEDS/DIRECTION
AND THE FACT THAT VFR VISIBILITY SHOULD PREVAIL...UNFORTUNATELY
THERE ARE SOME QUESTION MARKS REGARDING CEILING TRENDS...INVOLVING
BOTH WHEN A RETURN TO VFR MIGHT OCCUR AND IF SO FOR HOW LONG. IN
SHORT...OPTED TO ERR A BIT MORE ON THE CAUTIOUS/PESSIMISTIC SIDE
VERSUS PREVIOUS TAF ISSUANCE AND EXTEND AN MVFR CEILING THROUGH
18Z...WITH SOME MODELS/GUIDANCE SUGGESTING THIS MAY BE TOO
LONG...WHILE OTHERS SUGGEST IT MAY NOT BE LONG ENOUGH WITH THE
POTENTIAL FOR MVFR THROUGHOUT THE ENTIRE PERIOD. SO FOR NOW AM
JUST PLAYING A MIDDLE-GROUND. NO MATTER WHAT CEILINGS
DO...CONFIDENCE IS HIGH IN A PRECIPITATION-FREE PERIOD. WIND-
WISE...THINGS START OUT QUITE BRISK EARLY THIS MORNING WITH
SEVERAL MORE HOURS OF NORTHWESTERLY GUST POTENTIAL TO AROUND 30KT
POSSIBLE...ALTHOUGH A SLOW-BUT-STEADY DECREASING TREND WILL TAKE
PLACE DURING THE PERIOD WITH GUST POTENTIAL BY MID-DAY EASING
BELOW 20KT...AND IN FACT FAIRLY LIGHT BREEZES IN PLACE BY TUESDAY
EVENING AS HIGH PRESSURE SETTLES IN.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...HEINLEIN
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1125 PM CST MON DEC 15 2014
.SYNOPSIS...
ISSUED AT 315 PM CST MON DEC 15 2014
H5 ANALYSIS FROM EARLIER THIS MORNING HAD AN UPPER LEVEL
LOW OVER CENTRAL KS IN THE VICINITY OF SALINA WITH A TROUGH
EXTENDING SWD INTO THE ARKLATEX. DOWNSTREAM RIDGING WAS PRESENT
ACROSS THE EASTERN GREAT LAKES AND MID ATLANTIC STATES. NORTHWEST OF
THE CLOSED LOW...HIGH PRESSURE WAS PRESENT OVER NWRN ALBERTA...WHILE
A TROUGH OF LOW PRESSURE EXTENDED FROM THE GULF OF ALASKA SOUTH TO
JUST OFF THE COAST OF NRN CALIFORNIA. AS OF 2 PM CST...THE UPPER
LEVEL LOW HAD TRACKED FROM CENTRAL KS TO JUST NORTH OF CHILLICOTHE
MO. AT THE SURFACE...LOW PRESSURE WAS IN THE VICINITY OF LAMONI IOWA
WITH A COLD FRONT EXTENDING SSE INTO SOUTH CENTRAL MO. HIGH PRESSURE
WAS NOTED OVER EASTERN MT. ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA...STRONG NORTHERLY WINDS WERE PRESENT...ALONG WITH LIGHT
SNOW...WHICH AS REDUCED VISIBILITIES DOWN TO 1/2SM TO 2SM AS OF 2 PM
CST. UNDER CLOUDY SKIES...TEMPERATURES AS OF 2 PM CST RANGED
FROM...25 AT VALENTINE...TO 29 AT NORTH PLATTE...BROKEN BOW AND
OGALLALA.
&&
.UPDATE...
ISSUED AT 903 PM CST MON DEC 15 2014
RADAR IS QUIET BUT THERE IS LIGHT SNOW AT KONL WITH VISIBILITY
2 TO 3 MILES AND WIND SPEEDS NEVER CAME UP IN THIS AREA SO IT IS
NOT BLOWING SNOW. GIVEN THE RADAR TRENDS AT KLNX AND KFSD...THIS
SNOW SHOULD BE ENDING BY 11 PM SO THE WINTER WEATHER HIGHLIGHTS
HAVE BEEN ALLOWED TO EXPIRE AT 9 PM CST.
UPDATE ISSUED AT 612 PM CST MON DEC 15 2014
SOME WEATHER HIGHLIGHTS HAVE BEEN ALLOWED EXPIRE AT 6 PM. JUST
FLURRIES ARE INDICATED ALONG HIGHWAY 61 AND INTERSTATE 80. CLOUD
CEILINGS ARE RISING IN THIS AREA SUPPORTING LIGHTER WINDS.
THE HRRR...RAP AND NAM SHOW FOG ACROSS WRN NEB BY MORNING AS THE
MONTANA SFC HIGH PRESSURE SYSTEM BUILDS ACROSS THIS AREA BY 12Z
TUESDAY. ALSO...LOWERED OVERNIGHT TEMPERATURES IN THIS AREA.
THESE MODELS SHOW WINDS OF 5 KT OR LESS WITH CLEARING SKIES AND
RADIATIVE COOLING TAKING HOLD. SOME DRY AIR WILL BE MOVING IN
ALOFT SUPPORTING LOWS NEAR ZERO BUT NOT SO DRY AS TO SUPPORT
WIDESPREAD SUBZERO LOWS. FOG WILL LIKELY FORM BEFORE THIS HAPPENS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 315 PM CST MON DEC 15 2014
FOR THE NEXT 36 HOURS...MAIN FORECAST CONCERNS REVOLVE
AROUND THE EXIT OF THE UPPER LEVEL SYSTEM THAT IS BRINGING
WIDESPREAD ACCUMULATING SNOW TO THE REGION. TEMPERATURE FORECAST
TONIGHT AND TOMORROW ALSO DESERVES CONSIDERATION.
FORECAST GUIDANCE INDICATES THE UPPER LOW WILL CONTINUE TO THE EAST
OVER THE UPPER MISSISSIPPI VALLEY...AND GET CAUGHT UP IN A NORTHERN
STREAM SHORTWAVE/UPPER LOW OVER THE NEXT 24 HOURS. LOW AMPLITUDE
TRANSITORY RIDGING WILL THEN TAKE HOLD ACROSS THE CENTRAL PLAINS AS
THE NEXT UPPER LEVEL TROUGH DEEPENS OVER THE WESTERN COAST. AT THE
SURFACE...CANADIAN HIGH PRESSURE WILL FILL SOUTH BEHIND THE
DEPARTING SURFACE LOW PROVIDING FOR DRIER CONDITIONS AND COOLER
TEMPERATURES. WITH CAA FILTERING SOUTH ACROSS THE
PLAINS...OVERNIGHT LOWS WILL BE CHILLY...GENERALLY IN THE SINGLE
DIGITS AND LOWER TEENS FROM WEST TO EAST ACROSS THE FORECAST AREA.
THE OVERNIGHT TEMPERATURE FORECAST IS A PRODUCT OF NUMERICAL
GUIDANCE WITH THE PREVIOUS FORECAST...WHICH ASSUMES SOME CLEARING.
IF SUBSTANTIAL CLEARING WERE TO OCCUR...TEMPERATURES MAY PLUMMET
ACROSS OUR WESTERN ZONES AS A FRESH SNOWPACK COMBINES WITH LIGHT
WINDS. HIGHS REBOUND SOME TUESDAY...BUT WITH CANADIAN HIGH PRESSURE
OVERHEAD...AND WEAK COLD AIR ADVECTION CONTINUING...HIGHS SHOULD
ONLY TOP OUT IN THE 20S FOR LOCATIONS ALONG AND NORTH OF
I80...POSSIBLY A FEW LOWER 30S COULD BE ACHIEVED ACROSS OUR SOUTH AS
THE WINDS BEGIN TO VEER TO THE SOUTH LATE IN THE DAY BEHIND THE HIGH.
CONCERNING PRECIPITATION...NEAR TERM GUIDANCE HAS ACCUMULATING
SNOWFALL OUT OF THE CWA...SAVE FOR THE NORTHEASTERN SANDHILLS AND
NORTH CENTRAL NEBRASKA BY 00Z THIS EVENING...WITH SNOW ENDING
GENERALLY AT 03Z FOR OUR FAR NORTHEAST. THE FORECAST USED A BLEND
OF THE 15.12Z NAM12 WITH THE LATEST RAP WHICH SEEMS TO PROVIDE A
PLAUSIBLE NORTHWEST TO EAST DEMISE OF THE SNOWFALL. IR
SATELLITE/RADAR TRENDS OVER THE PAST FEW HOURS EARLY AFTERNOON
SUPPORT THE IDEA AS CLOUD TOPS ARE WARMING AND REFLECTIVITY IS
BECOMING LESS DEFINED. SUPPOSE ANOTHER INCH OR TWO OF SNOW IS STILL
POSSIBLE ACROSS OUR NORTHERN ZONES LATE THIS AFTERNOON AS THE MODELS
SUGGEST QPF RATES OF UP TO FIVE HUNDREDTHS OF AN INCH PER HOUR
CONTINUING UNTIL 03Z. IMPACTS FROM ANY ADDITIONAL SNOW HOWEVER WILL
CONTINUE TO COMPOUND VISIBILITY ISSUES WITH BLOWING SNOW FROM THE
30-40 MPH GUSTS OCCURRING...WINDS WILL WEAKEN THOUGH AS THE PRESSURE
GRADIENT RELAXES THIS EVENING.
THE CURRENT WINTER STORM WARNING AND WINTER WEATHER ADVISORY WILL
EXPIRE AT 00Z THIS EVENING...BUT A FEW SMALL CHANGES MAYBE/ARE
NEEDED. ACROSS NORTH CENTRAL NEBRASKA...A EXTENSION OF THE
ADVISORY/WARNING IS NEEDED THROUGH 03Z TO ACCOUNT FOR THE LATER
ENDING TIME OF SNOW AND GUSTY NORTHWEST WIND. COUNTIES MAY BE
DROPPED ACROSS OUR FAR SOUTH EARLY..BUT THE RECENT OB FROM KMCK
SUGGEST LIGHT TO OCCASIONAL MODERATE SNOW...WILL RE-EVALUATE IN THE
NEXT COUPLE HORUS. ELSEWHERE THE HEADLINES ARE ANTICIPATED TO BE
ALLOWED TO EXPIRE ON TIME.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 315 PM CST MON DEC 15 2014
MID RANGE...TUESDAY NIGHT THROUGH THURSDAY...IN THE MID
RANGE PERIODS...TEMPERATURES AND PRECIPITATION CHANCES ON WEDNESDAY
NIGHT ARE THE MAIN FORECASTING CHALLENGES IN THE MID RANGE PERIODS.
FOR TUESDAY NIGHT...A TROUGH OF LOW PRESSURE ALOFT WILL PUSH INTO
SRN CALIFORNIA RESULTING IN ANOTHER SOAKER FOR THE SWRN CONUS.
DOWNSTREAM OF THE TROUGH...LOW AMPLITUDE RIDGING WILL EXTEND ACROSS
THE SRN PLAINS INTO NEBRASKA. SURFACE HIGH PRESSURE WILL DOMINATE
THE PLAINS STATES AND OZARKS TUESDAY NIGHT. WITH FRESH
SNOWCOVER...LIGHT WINDS AND PARTLY CLOUDY SKIES...LOWS WILL BE COLD
IN THE SINGLE DIGITS AND LOWS WERE TRENDED DOWNWARD FROM THE
INHERITED FORECAST. FOR WEDNESDAY AND WEDNESDAY NIGHT...THE UPPER
LEVEL TROUGH WILL MIGRATE EAST INTO THE DESERT SOUTHWEST. SOME MODEL
DIFFERENCES WERE NOTED WITH THE FORWARD SPEED AND TRACK OF THIS
SYSTEM MIDWEEK. THE LATEST NAM AND ECMWF SOLNS FROM 12Z THIS MORNING
ACTUALLY DEVELOP A CLOSED LOW ALONG THE AZ/NM AND MEXICAN BORDER AT
00Z FRIDAY. THE GFS IS FASTER AND OPEN WITH THIS SYSTEM...MIGRATING
IT INTO NM AND WEST TX BY 00Z FRIDAY. WHAT ALL THREE MODELS DO
INDICATE IS A LEAD DISTURBANCE WHICH CROSSES THE SRN PLAINS INTO THE
OZARKS WEDNESDAY NIGHT. BOTH THE GFS AND ECMWF SOLNS LIFT INCREASED
LOW LEVEL MOISTURE INTO SRN NEBRASKA WEDNESDAY NIGHT IN ASSOCIATION
WITH THE LEAD DISTURBANCE. LIFT HOWEVER REMAINS WEAK PER CROSS
SECTIONS...AND WITH A FAIRLY DRY LAYER AROUND H7...AM NOT TOO
EXCITED ABOUT PCPN IN OUR AREA WEDS NIGHT. INHERITED FCST HAD A
SLIGHT CHANCE MENTION IN THE SOUTH AND SERN CWA DURING THE PERIOD
AND GIVEN THE LOW LEVEL MOISTURE AND SOME MODEL AGREEMENT BETWEEN
THE GFS AND ECMWF SOLNS...WILL LEAVE POP MENTION UNCHANGED FOR NOW.
AS FOR PTYPE WEDNESDAY NIGHT...LOOKING AT FCST SOUNDINGS...WAS
INITIALLY A LITTLE CONCERNED ABOUT THE THREAT FOR FREEZING DRIZZLE
IN THE SERN CWA. LOOKING AT BUFKIT SOUNDINGS...THE THREAT FOR FZDZ
SHOULD BE OFF TO THE SOUTHEAST OF THE FORECAST AREA AND WILL LEAVE
PRECIP MENTION AS ALL SNOW.
THURSDAY NIGHT THROUGH MONDAY...A TANDEM OF SRN STREAM WAVES WILL
TRACK ACROSS THE SRN TIER OF STATES FRIDAY...AND THEN AGAIN SUNDAY
NIGHT INTO MONDAY. ATTM...FAVORABLE FORCING FOR PRECIPITATION SHOULD
REMAIN SOUTH OF THE FORECAST AREA SO WILL FORECAST DRY CONDS ATTM.
HOWEVER...THE LATEST GFS SOLN BEGINS TO DIVERGE TOWARD A MORE ACTIVE
NRN STREAM NEXT WEEK...FORCING A CLIPPER SYSTEM THROUGH THE NRN
PLAINS EARLY NEXT WEEK...FOLLOWED BY SECOND...MUCH STRONGER NRN
STREAM SYSTEM AROUND CHRISTMAS EVE. IF THIS WOULD VERIFY...WE COULD
SEE COLD TEMPERATURES AND A POSSIBLE THREAT FOR SNOW. IN THE
MEANTIME...DECIDED TO KEEP CONDS DRY THROUGH THE WEEKEND AND INTO
NEXT WEEK...GIVEN THE ACTIVE SRN STREAM...WITH PCPN EXPECTED WELL
SOUTH OF THE FCST AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1125 PM CST MON DEC 15 2014
WIDESPREAD MVFR CIGS EXTEND THROUGH THE FCST NORTH INTO THE NRN
PLAINS AND SOME MODELS HOLD THEM IN PLACE OVERNIGHT THROUGH
TUESDAY WHILE OTHERS MIX OUT TO VFR ALMOST IMMEDIATELY. SINCE THE
MODELS ARE FAIRLY EVENLY SPLIT...NO CONSENSUS...THE FCST RELIES ON
DAYTIME MIXING WITH VFR EXPECTED 15Z-18Z TUESDAY. VFR IS EXPECTED
THEREAFTER.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CDC
SYNOPSIS...CLB
SHORT TERM...JACOBS
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1036 PM MST MON DEC 15 2014
.AVIATION...
06Z TAF CYCLE
A RIDGE OF HIGH PRESSURE WILL CROSS ALOFT FOR THE REST OF TONIGHT.
THE CEILING WILL GRADUALLY LOWER AS AN UPPER LEVEL TROUGH
APPROACHES FROM THE WEST TUESDAY AND TUESDAY NIGHT. WINTRY
PRECIPITATION SHOULD DEVELOP ALONG AND WEST OF THE CONTDVD LATE
TUESDAY NIGHT WITH FLIGHT CATEGORY RESTRICTIONS AND MT
OBSCURATIONS.
44
&&
.PREV DISCUSSION...346 PM MST MON DEC 15 2014...
.SYNOPSIS...
HIGH CLOUDS WILL ONCE AGAIN STREAM IN FROM THE WEST THIS EVENING
THROUGH THE DAY TUESDAY. ANOTHER PACIFIC STORM SYSTEM AND THE
ASSOCIATED MOISTURE OUT AHEAD OF IT WILL BRING A FEW LIGHT SHOWERS
TO THE NORTHWEST THIRD OF THE STATE TUESDAY NIGHT. AS THE MAIN
STORM SYSTEM MOVES INTO ARIZONA WEDNESDAY EVENING...SCATTERED SHOWERS
AND SNOW SHOWERS ABOVE ABOUT 6000 FEET WILL SPREAD INTO WESTERN NEW
MEXICO. THE SHOWERS WILL SPREAD INTO CENTRAL NEW MEXICO THURSDAY.
SIGNIFICANT SNOW IS POSSIBLE OVER ALL MOUNTAIN AREAS. HIGH PRESSURE
RETURNS FOR FRIDAY AND SATURDAY WITH THE NEXT STORM SYSTEM
EXPECTED SUNDAY AND MONDAY.
&&
.DISCUSSION...
RIBBON OF STRONG NORTHWEST WINDS CONTINUE FROM THE SANDIA AND MANZANO
MOUNTAINS EAST TO CLINES CORNERS. RUC AND NAM BOTH INDICATING THESE
STRONG NW WINDS WILL DIMINISH RAPIDLY AROUND SUNSET. LEFT OUT MENTION
OF OVERNIGHT FOG OUTSIDE THE MORENO VALLEY GIVEN THAT NAMBUFR DATA
SUGGESTING THAT SCATTERED TO BROKEN MID CLOUDS WILL SPREAD FROM
SOUTHWEST TO NORTHEAST ACROSS WESTERN AND CENTRAL NEW MEXICO
TONIGHT...LIMITING RADIATIONAL COOLING. WEAK BACKDOOR COLD FRONT
EXPECTED TO SLIDE SWD INTO NE NM THIS EVENING. LOWERED OVERNIGHT
LOW TEMPERATURES A FEW DEGREES BELOW GUIDANCE FOR THE NE PLAINS AS
A RESULT. A BRIEF SPURT OF LIGHT EAST WINDS IS POSSIBLE INTO THE
MIDDLE RIO GRANDE VALLEY TUESDAY MORNING.
NAM AND GFS IN GOOD AGREEMENT THAT THE OVERHEAD RIDGE AXIS WILL SHIFT
EAST OF NM LATE TONIGHT/TUESDAY MORNING. INCREASING SOUTHWEST FLOW
ALOFT WILL RESULT IN SLIGHT WARMING FOR TUESDAY BUT PLENTIFUL HIGH
CLOUDS WILL KEEP THE WARMING IN CHECK.
MODELS IN FAIRLY GOOD AGREEMENT REGARDING THE NEXT UPPER LEVEL
TROUGH/CLOSED LOW FOR WEDNESDAY AND THURSDAY. SUB-TROPICAL JET
STREAM SPEED MAXIMA MOVE UP FROM THE SOUTHWEST TUESDAY NIGHT AND
WEDNESDAY MORNING...BRINGING CHANCES FOR SHOWERS AND SNOW SHOWERS
ABOVE ABOUT 6500FT OVER THE NORTHWEST THIRD OR SO OF THE STATE.
GFS AND NAM STILL AT ODDS WITH ONE ANOTHER AS TO WHEN TO BRING
THE MAIN TROUGH./CLOSED LOW THROUGH THE STATE AND WHEN BEST
CHANCES FOR PRECIP WILL BE WEDNESDAY OR THURSDAY. SIGNIFICANT SNOW
IS POSSIBLE OVER ALL MOUNTAIN AREAS WEDNESDAY NIGHT OR THURSDAY
GIVEN THE PWAT AMOUNT AVAILABLE. FUTURE MODEL RUNS SHOULD COME TO BETTER
AGREEMENT WITH REGARD TO TIMING BUT FOR NOW HAVE ADVISORY SNOW
AMOUNTS ABOVE ABOUT 7000FT WEDNESDAY NIGHT AND THURSDAY IN THE
GRIDS.
GFS STARTED WITH 06Z RUN LAST NIGHT BUT NOW ALL GLOBAL MODELS
TRENDING AWAY FROM A SLOW MOVING CLOSED LOW FOR THE WEEKEND. BOTH GFS
AND ECMWF TRENDING TOWARD A MUCH MORE PROGRESSIVE TROUGH. SLIGHT
VARIATIONS IN THE EXCEPTIONALLY FAST (185-190KT) PACIFIC JET
STREAM OVER THE CENTRAL PACIFIC ARE LEADING TO LARGE RUN TO RUN
MODEL DIFFERENCES. LOW CONFIDENCE IN THE FORECAST BEYOND FRIDAY
CONTINUES WITH SUCH BIG RUN TO RUN SWINGS. OVERALL PATTERN REMAINS
ACTIVE BUT STRENGTH OF SYSTEMS REMAINS IN QUESTION AT THIS TIME.
33
&&
.FIRE WEATHER...
POOR VENTILATION TODAY...BUT SOME IMPROVEMENT FORECAST TUESDAY INTO
WEDNESDAY AS AN UPPER LEVEL RIDGE AXIS SHIFTS EAST OF THE AREA AND
WINDS THROUGHOUT THE COLUMN RESPOND TO A TROUGH PROGRESSING EASTWARD
INTO THE DESERT SW AND GREAT BASIN. ALTHOUGH VENT RATES WILL TREND
UP TO FAIR/GOOD MOST AREAS BY WEDNESDAY...POCKETS OF POOR WILL STILL
REMAIN IN SOME VALLEYS.
ANOTHER WETTING EVENT LOOKS ON TRACK FOR WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT...ESPECIALLY ACROSS WESTERN AND NORTH CENTRAL
PORTIONS OF THE AREA. THE 12Z MODEL SOLUTIONS ARE SHOWING A MESSY
TROUGH PASSAGE SCENARIO WITH SEVERAL SHORTWAVE TROUGHS IMPACTING THE
PASSAGE OF AN UPPER LEVEL LOW...WHICH IS DIFFERENT FROM YESTERDAY`S
12Z RUNS. THE 18Z NAM SHOWS A WETTER SCENARIO WITH A MORE COHERENT
UPPER LEVEL LOW MOVING EAST ACROSS THE FORECAST AREA THURSDAY NIGHT.
POTENTIAL FOR A WIDESPREAD WETTING EVENT IS THERE...BUT FORECASTER
CONFIDENCE IS ONLY MODERATE AT THIS POINT GIVEN THE MODEL RUN-TO-RUN
INCONSISTENCY. VENT RATES WILL TAKE A HIT BEHIND THE DEPARTING
TROUGH THROUGH SATURDAY BEFORE IMPROVING AGAIN.
FORECAST UNCERTAINTY FOR A LATE WEEKEND AND EARLY NEXT WEEK WETTING
EVENT HAS INCREASED GIVEN THE 12Z MEDIUM RANGE MODEL SOLUTIONS...
WHICH LOOK MUCH DIFFERENT THAN THE 00Z RUNS...ESPECIALLY THE GFS
WHICH IS NOW SHOWING A PROGRESSIVE OPEN WAVE. REGARDLESS...MODERATE
TO HIGH FORECASTER CONFIDENCE ON THE UNSETTLED AND POTENTIALLY WET
PATTERN PERSISTING THROUGH EARLY NEXT WEEK.
11
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1132 PM CST MON DEC 15 2014
.UPDATE...
ISSUED AT 940 PM CST MON DEC 15 2014
THERE IS SOME CLEARING WORKING INTO THE REGION FROM THE
NORTH...BUT ANOTHER AREA OF CLOUDS MOVING INTO THE REGION FROM THE
NORTHEAST. DID DECREASE SKY A BIT...BUT WILL CONTINUE THE MOSTLY
CLOUDY THINKING. WINDS WILL REMAIN ELEVATED...WHICH WILL KEEP
TEMPERATURES FROM BOTTOMING OUT WHETHER THERE ARE CLOUDS OR NO
CLOUDS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 330 PM CST MON DEC 15 2014
FORECAST CHALLENGE CONCERNS LINGERING PCPN CHANCES ACROSS THE SE
AND TEMPERATURES. MODELS OVERALL IN GOOD AGREEMENT AND WILL USE
BLEND FOR FORECAST.
DEFORMATION BAND OF PCPN FROM EXTREME SE ND INTO WEST CENTRAL MN
HAS SHOWN WEAKENING TREND AND HAS TRANSITION OVER TO ALL SNOW
WHICH LINES UP WELL WITH RUC SOUNDINGS. FORTUNATELY WEB CAMS
WITHIN HEAVIEST BAND INDICTED ONLY MINOR ACCUMULATIONS AND GOOD
VISIBILITY. AS SURFACE LOW PROPAGATES EAST THIS EVENING
DEFORMATION ZONE PCPN SHOULD FOLLOW WITH CONTINUED WEAKENING. WITH
EXPECTED TRENDS WILL EXPIRE CURRENT HEADLINES WITH FORECAST
ISSUANCE. GUSTY NORTH WINDS WHICH AT TIMES HAVE FLIRTED WITH
ADVISORY CRITERIA WILL CONTINUE TO DIMINISH THROUGH THE EVENING.
SOME BREAKS IN THE CLOUDS OCCURRING OVER MB LAKES REGION COULD WORK
INTO THE NORTHERN FA TONIGHT HOWEVER FOR THE MOST PART CLOUDS
SHOULD HOLD. CLOUDS AND WIND SHOULD OFF SET COLD ADVECTION WHICH
LEVELS OFF AFTER MIDNIGHT SO EXPECTING MINIMUMS A BIT ABOVE
SEASONAL AVERAGES.
HIGH PRESSURE PUSHES INTO THE REGION TUESDAY. COLUMN GRADUALLY
DRIES OUT HOWEVER W-NW FA MAY BE THE ONLY AREAS WITH ANY POTENTIAL
FOR SOLAR. THIS WILL LIMIT TEMPERATURE RECOVERY KEEPING MAXIMUM
TEMPERATURES BLO AVERAGE.
AS HIGH CONTINUES TO BUILD IN TOMORROW NIGHT DIMINISHING WINDS AND
CLEARING SHOULD ALLOW TEMPERATURES TO DROP INTO THE SINGLE DIGITS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 330 PM CST MON DEC 15 2014
HIGH PRESSURE WILL COVER FA WEDNESDAY AND DEGREE OF SOLAR WILL
IMPACT TEMPERATURES HOWEVER WITH COLD START TEMPERATURES WILL
STRUGGLE OUT OF THE TEENS.
COLUMN BEGINS TO RECOVER THURSDAY AND WITH SOLAR AND LACK OF SNOW
COVER TEMPERATURES SHOULD BE ABLE TO CLIMB BACK TO AVERAGE.
FOR THU NIGHT THROUGH MONDAY...KIND OF A MUDDLED MID LEVEL FLOW
PATTERN OVER THE NORTHERN PLAINS FOR FRI THRU SUNDAY. NOT MUCH UPPER
LEVEL ENERGY TO WORK WITH. AT THE SFC...BROAD HIGH PRESSURE REMAINS
ANCHORED OVER THE GREAT LAKES BUT STILL KEEPING SOME INFLUENCE OVER
THIS FA. THEREFORE ALTHOUGH MODELS KICK OUT SOME MINIMAL PCPN AT
TIMES WILL KEEP THIS PERIOD DRY. BY SUNDAY NIGHT INTO MONDAY WEST
COAST RIDGE STARTS TO BUILD UP A LITTLE RESULTING IN NORTHWEST FLOW
IN THIS AREA. SFC PATTERN STILL UNCERTAIN AND THEREFORE PCPN FIELDS
DIFFER QUITE A BIT BETWEEN MODELS. DESPITE THESE DIFFERENCES WILL
KEEP SOME CHANCES FOR LIGHT SNOW ON MONDAY WITH LOW PRESSURE IN THE
AREA. TEMPS LOOK TO STAY ABOVE NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1132 PM CST MON DEC 15 2014
PREVIOUS THINKING STILL SEEMS TO BE WORKING OUT OK. THERE ARE SOME
CLEAR AREAS ACROSS THE REGION...BUT APPEAR TO BE SHORT-LIVED
ACCORDING TO SATELLITE IMAGERY. ANTICIPATE MAINLY MVFR CONDITIONS
THROUGH THE MORNING HOURS...WITH CLEARING AND/OR VFR CONDITIONS
BECOMING MORE LIKELY SOMETIME TUESDAY AFTERNOON OR EVENING. WINDS
WILL GRADUALLY DIMINISH THROUGH THE PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...VOELKER
LONG TERM...GODON/VOELKER
AVIATION...TG
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
405 AM EST TUE DEC 16 2014
.SYNOPSIS...
OCCASIONAL SHOWERS ARE EXPECTED TODAY AS A LOW PRESSURE SYSTEM
LIFTS NORTHEAST INTO THE GREAT LAKES REGION. A COLDER AIRMASS
WILL THEN SETTLE INTO THE REGION WITH SEASONABLY COOLER
TEMPERATURES EXPECTED THROUGH THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A FAIRLY SOLID LINE OF SHOWERS IS CURRENTLY MOVING THROUGH
SOUTHEAST INDIANA AND INTO FAR WESTERN OHIO. THESE SHOWERS ARE
WITHIN A LOW LEVEL CONVERGENT BOUNDARY ASSOCIATED WITH AN
APPROACHING FRONTAL BOUNDARY. VERY MARGINAL INSTABILITY IS WORKING
NORTHEAST INTO SOUTHERN PORTIONS OF OUR FA AND THIS HAS ALLOWED
FOR A FEW EMBEDDED THUNDERSTORMS TO DEVELOP. INTERESTINGLY...THE
SHERB PARAMETER OFF BOTH THE RAP AND NAM SEEMS TO BE PICKING UP
ON SOME OF THIS BETTER FORCING/INSTABILITY...WITH A NARROW AXIS OF
HIGHER VALUES MOVING THROUGH THE TRI STATE REGION OVER THE NEXT
FEW HOURS. AS A RESULT...WILL INCLUDE AN ISOLATED THUNDERSTORM THROUGH
DAYBREAK ACROSS SOUTHWEST PORTIONS OF OUR FA. THE BULK OF THE PCPN
SHOULD CONTINUE TO PIVOT UP ACROSS NORTHERN PORTIONS OF OUR FA
THROUGH LATE MORNING. EXPECT PCPN TO THEN BECOME MORE SCATTERED AS
WE HEAD INTO THIS AFTERNOON AND GET INTO SOME WRAP AROUND
MOISTURE. EXPECT EARLY HIGHS TODAY WITH TEMPERATURES THEN LEVELING
OFF OR EVEN BEGINNING TO FALL AS WE START TO GET INTO SOME
DEVELOPING LOW LEVEL CAA THROUGH THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
THE LOW PRESSURE WILL CONTINUE TO LIFT OFF TO THE NORTHEAST TONIGHT
WITH PCPN TAPERING OFF TO JUST A FEW SHOWERS THROUGH THIS EVENING.
IT STILL LOOKS LIKE THE DEEPER MOISTURE WILL BE EXITING OUR AREA
BEFORE THE BOUNDARY LAYER COOLS OFF ENOUGH FOR MUCH IN THE WAY OF
SNOW. AS A RESULT..WILL JUST ALLOW FOR A BRIEF MIX ACROSS THE
NORTH LATER THIS EVENING AS THE PCPN TAPERS OFF. HIGH PRESSURE
WILL THEN BUILD INTO THE REGION FOR WEDNESDAY INTO THURSDAY.
TEMPERATURES WILL BE SEASONABLY COOL WITH HIGHS ONLY IN THE 30S
WEDNESDAY AND THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
FORECAST PERIOD BEGINS WITH THE MODELS IN AGREEMENT IN PLACING A
STRUNG OUT HIGH PRESSURE SYSTEM FROM THE NORTHERN PLAINS DOWN INTO
THE UPPER OHIO VALLEY. THE HIGH WILL DRIFT SLOWLY EASTWARD PROVIDING
DRY CONDITIONS THROUGH FRIDAY.
THE GFS CONTINUES WITH ITS STRUGGLES IN DEALING WITH ENERGY SWINGING
OUT OF THE LOWER MS VALLEY FRIDAY. AFTER WINDING UP A LOW AND
LIFTING IT N INTO THE REGION WITH YESTERDAYS RUN...THE GFS NOW TAKES
A QUICK MOVING SHEARED OUT H5 VORT INTO THE TN VALLEY AND SPREADS
PCPN INTO SOUTHERN PORTIONS OF THE REGION MUCH QUICKER THAN THE
OTHER MODELS FRIDAY NIGHT. THE ECMWF HAS BEEN CONSISTENT WITH ITS
SOLUTION OF A TAKING A SLOWER A MORE DEFINED SFC LOW INTO THE
CAROLINAS FRIDAY NIGHT INTO SATURDAY. WILL CONTINUE TO FOLLOW THE
ECMWF SOLUTION AS IT IS BACKED BY THE CONSENSUS OF THE MODELS.
SO BROUGHT SOME SLIGHT CHANCE/CHANCE POPS INTO SOUTHERN SECTIONS
LATE FRIDAY NIGHT. SINCE WE ARE ON THE EXTREME NRN EDGE..MOST OF THE
PCPN SHOULD FALL AS SNOW...BUT CANT RULE OUT SOME SLEET OR RAIN
MIXING IN. AS THE SFC PATTERN TRANSITIONS TO THE EAST COAST ON
SATURDAY...A H5 S/W SWINGING THRU WILL PROVIDE LIFT AND WILL PULL
PCPN ACROSS THE AREA. A CHANCE OF LIGHT SNOW WILL TRANSITION TO A
RAIN/SNOW MIX DURING THE DAY ON SATURDAY. A CHANCE OF SNOW WILL
LINGER INTO SATURDAY NIGHT AND EARLY SUNDAY.
HIGH PRESSURE WILL BUILD IN FOR THE LAST FEW DAYS OF THE FORECAST
PERIOD.
HIGHS THRU THE PERIOD WILL BE NEAR TO SLIGHTLY BELOW NORMAL. SOUTHERN
LOCATIONS MIGHT MAKE IT INTO THE 40S FRIDAY WHILE THE NORTH
REMAINS IN THE 30S. COOLER AIR WILL WORK BACK IN SATURDAY THRU
MONDAY KEEPING HIGHS IN THE 30S.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
AN OCCLUDED FRONT WILL PUSH ACROSS THE REGION BY MID-MORNING.
THERE WILL BE SCATTERED LIGHT SHOWERS BOTH AHEAD AND ALONG THIS
BOUNDARY. DO NOT EXPECT ANY PRECIPITATION TO CAUSE VISIBILITY
RESTRICTIONS. HOWEVER CEILINGS WILL LOWER TO MVFR AND EVENTUALLY
DROP BELOW 2000 FT. WINDS WILL SHIFT TO SOUTH WITH THE FRONTAL
PASSAGE. THE WINDS WILL VEER TO SOUTHWEST AND STRENGTHEN SOME
AFTER 15Z. MVFR CEILINGS WILL CONTINUE TO PREVAIL. SOME SHOWERS
WILL REMAIN POSSIBLE. BY NOON ANY LINGER SHOWERS WILL BE
INCONSEQUENTIAL AND HAVE BEEN LEFT OUT OF THE FORECAST. NOT MUCH
CHANGE THROUGH THE REMAINDER OF THE FORECAST PERIOD AS MVFR CONDS
WILL PREVAIL AND WINDS WILL REMAIN GUSTY WELL INTO THE NIGHTTIME
HOURS.
OUTLOOK...MVFR CEILINGS WILL CONTINUE INTO WEDNESDAY. MVFR
CEILINGS AND VISIBILITIES POSSIBLE FRIDAY NIGHT INTO SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JGL
NEAR TERM...JGL
SHORT TERM...JGL
LONG TERM...SITES
AVIATION...HAYDU
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
109 AM EST TUE DEC 16 2014
.SYNOPSIS...
OCCLUDED LOW PRESSURE WILL TRAVEL FROM THE MISSISSIPPI VALLEY TO
THE GREAT LAKES TONIGHT THROUGH TUESDAY. SHOWERS WILL DEVELOP
IN THE MOIST FLOW CIRCULATING AROUND THE LOW. PRECIPITATION WILL
END BY WEDNESDAY AS THE LOW TRAVELS EAST...WITH COLDER
TEMPERATURES ARRIVING ON A BRISK WESTERLY FLOW BEHIND THE LOW.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SHOWERS HAVE FINALLY DEVELOPED INTO A BAND AS THEY ENTERED THE
FORECAST AREA. EXPECT THIS TO CONTINUE TO SWEEP EAST NORTHEAST
OVERNIGHT. RECENT HRRR AND RAP RUNS HAVE BEEN SUGGESTING THAT
ANOTHER AREA OF SHOWERS WILL DEVELOP AFTER 06Z AND MOVE NORTHEAST.
HAVE ADJUSTED POPS ACCORDINGLY. RAINFALL AMOUNTS WILL MOSTLY
REMAIN ON THE LIGHT SIDE. CLOUDS AND AND LACK OF TEMPERATURE
ADVECTION WILL RESULT IN LITTLE MOVEMENT TO TEMPERATURES THROUGH
THE NIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
LOW PRESSURE WILL BE PUSHING THROUGH THE GREAT LAKES ON TUESDAY. A
CHANCE OF SHOWERS WILL PERSIST IN THE RELATIVELY MOIST CYCLONIC
FLOW BEHIND THE LOW.
AS THE BRISK WESTERLY FLOW CONTINUES IN THE WAKE OF THE LOW NOW
OVER SOUTHEAST CANADA...DRIER AIR AT THE LEADING EDGE OF HIGH
PRESSURE WILL FILTER IN BY WEDNESDAY...BRINGING AN END TO
PRECIPITATION.
HIGH TEMPERATURES WILL STAY CLOSE TO 50 TUESDAY IN THE MILD REGIME
SURROUNDING THE DEPARTING LOW. COLDER HIGHS AROUND 40 ARE IN STORE
FOR WEDNESDAY AS COLD ADVECTION RESULTS IN A RETURN TO NEAR NORMAL
TEMPERATURES.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
FORECAST PERIOD BEGINS WITH THE MODELS IN AGREEMENT IN PLACING A
STRUNG OUT HIGH PRESSURE SYSTEM FROM THE NORTHERN PLAINS DOWN INTO
THE UPPER OHIO VALLEY. THE HIGH WILL DRIFT SLOWLY EASTWARD PROVIDING
DRY CONDITIONS THROUGH FRIDAY.
THE GFS CONTINUES WITH ITS STRUGGLES IN DEALING WITH ENERGY SWINGING
OUT OF THE LOWER MS VALLEY FRIDAY. AFTER WINDING UP A LOW AND
LIFTING IT N INTO THE REGION WITH YESTERDAYS RUN...THE GFS NOW TAKES
A QUICK MOVING SHEARED OUT H5 VORT INTO THE TN VALLEY AND SPREADS
PCPN INTO SOUTHERN PORTIONS OF THE REGION MUCH QUICKER THAN THE
OTHER MODELS FRIDAY NIGHT. THE ECMWF HAS BEEN CONSISTENT WITH ITS
SOLUTION OF A TAKING A SLOWER A MORE DEFINED SFC LOW INTO THE
CAROLINAS FRIDAY NIGHT INTO SATURDAY. WILL CONTINUE TO FOLLOW THE
ECMWF SOLUTION AS IT IS BACKED BY THE CONSENSUS OF THE MODELS.
SO BROUGHT SOME SLIGHT CHANCE/CHANCE POPS INTO SOUTHERN SECTIONS
LATE FRIDAY NIGHT. SINCE WE ARE ON THE EXTREME NRN EDGE..MOST OF THE
PCPN SHOULD FALL AS SNOW...BUT CANT RULE OUT SOME SLEET OR RAIN
MIXING IN. AS THE SFC PATTERN TRANSITIONS TO THE EAST COAST ON
SATURDAY...A H5 S/W SWINGING THRU WILL PROVIDE LIFT AND WILL PULL
PCPN ACROSS THE AREA. A CHANCE OF LIGHT SNOW WILL TRANSITION TO A
RAIN/SNOW MIX DURING THE DAY ON SATURDAY. A CHANCE OF SNOW WILL
LINGER INTO SATURDAY NIGHT AND EARLY SUNDAY.
HIGH PRESSURE WILL BUILD IN FOR THE LAST FEW DAYS OF THE FORECAST
PERIOD.
HIGHS THRU THE PERIOD WILL BE NEAR TO SLIGHTLY BELOW NORMAL. THEY
SHOULD RANGE IN THE 30S FOR THURSDAY. SOUTHERN LOCATIONS MIGHT MAKE
IT INTO THE 40S FRIDAY WHILE THE NORTH REMAINS IN THE 30S. COOLER
AIR WILL WORK BACK IN SATURDAY THRU MONDAY KEEPING HIGHS IN THE 30S.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AN OCCLUDED FRONT WILL PUSH ACROSS THE REGION BY MID-MORNING.
THERE WILL BE SCATTERED LIGHT SHOWERS BOTH AHEAD AND ALONG THIS
BOUNDARY. DO NOT EXPECT ANY PRECIPITATION TO CAUSE VISIBILITY
RESTRICTIONS. HOWEVER CEILINGS WILL LOWER TO MVFR AND EVENTUALLY
DROP BELOW 2000 FT. WINDS WILL SHIFT TO SOUTH WITH THE FRONTAL
PASSAGE. THE WINDS WILL VEER TO SOUTHWEST AND STRENGTHEN SOME
AFTER 15Z. MVFR CEILINGS WILL CONTINUE TO PREVAIL. SOME SHOWERS
WILL REMAIN POSSIBLE. BY NOON ANY LINGER SHOWERS WILL BE
INCONSEQUENTIAL AND HAVE BEEN LEFT OUT OF THE FORECAST. NOT MUCH
CHANGE THROUGH THE REMAINDER OF THE FORECAST PERIOD AS MVFR CONDS
WILL PREVAIL AND WINDS WILL REMAIN GUSTY WELL INTO THE NIGHTTIME
HOURS.
OUTLOOK...MVFR CEILINGS WILL CONTINUE INTO WEDNESDAY. MVFR
CEILINGS AND VISIBILITIES POSSIBLE FRIDAY NIGHT INTO SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...CONIGLIO
NEAR TERM...
SHORT TERM...CONIGLIO
LONG TERM...SITES
AVIATION...HAYDU
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1157 PM EST MON DEC 15 2014
.SYNOPSIS...
LOW PRESSURE IN THE CENTRAL PLAINS WILL MOVE ACROSS THE CENTRAL
GREAT LAKES REGION TUESDAY DRAGGING A FRONTAL SYSTEM ACROSS THE
REGION. HIGH PRESSURE WILL BUILD IN LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
SPEEDED UP TIMING OF RAIN SLIGHTLY FOR THE 930 UPDATE..
ORIGINAL DISCUSSION...
MODELS SHOW LOW PRESSURE ACROSS IOWA AND NRN MO LATE THIS
AFTERNOON WITH THE AXIS OF AN UPPER RIDGE JUST TO OUR EAST.
SUBSIDENCE AHEAD OF THE APPROACHING LOW HAS ALLOWED THE CLOUDS TO
BREAK THROUGH THE AFTERNOON ACROSS MUCH OF THE AREA. THE PROGRESS
OF THE LOW HOWEVER WILL TAKE IT TO SRN LAKE MI OVERNIGHT WITH A
COLD FRONT/OCCLUDED FRONT SOUTHEAST INTO WESTERN OHIO BY 12Z.
PRECIP TO OUR WEST AHEAD OF THE SYSTEM SO FAR IS NOT TOO
IMPRESSIVE HOWEVER FOLLOWING THE HRRR NAM AND SREF...MODELS BRING
IN A SWATH OF RAIN THROUGH THE EVENING EXPANDING IT THROUGH THE
EVENING AND OVERNIGHT AS THE UPPER SYSTEM AND ASSOCIATED DYNAMICS
OVERSPREAD THE REGION. WILL HAVE CAT POPS FOR MOST...MOVING FROM
WEST TO EAST THROUGH THE NIGHT. LOWS GENERALLY UPPER 30S TO LOWER
40S.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/...
TUESDAY BEGINS WITH LOW PRESSURE OVER SRN LAKE MI WITH A
COLD/OCCLUDED FRONT NEAR A KTOL-KFDY-KCMH. EXPECTING RAIN TO BE
OCCURRING ACROSS NWRN PA FROM THE INITIAL SURGE FINALLY REACHING
THE AREA JUST BEFORE DAWN. CENTRAL COUNTIES...PRECIP COULD BEGIN
SPOTTY WITH A MARGINAL DRY SLOT ACROSS MUCH OF THE AREA. MOISTURE
WITH THE UPPER SYSTEM WILL BE MOVING INTO THE WEST. THE UPPER LOW
WILL MOVE ENE ACROSS THE CENTRAL LAKES DURING THE DAY WITH DEEP
MOISTURE AND WEAK COLD ADVECTION SPREADING ACROSS THE CWA. WILL
HAVE LIKELY POPS ACROSS THE AREA DURING THE DAY FOR RAIN. THE
UPPER TROUGH AXIS SHIFTS EAST THROUGH THE EVENING. AM THINKING
WESTERN COUNTIES COULD POSSIBLY SEE A FEW SHOWERS THROUGH THE
EVENING BUT WITH FORCING GONE TAPERED POPS WEST THROUGH THE
OVERNIGHT TO SLIGHT CHANCE. WINDS TURN OFF THE LAKE FOR THE SNOW
BELT TUESDAY NIGHT BUT 850MB TEMPS NOT LOW ENOUGH FOR LAKE
INSTABILITY. WILL HOLD ONTO CHANCE POPS GIVEN MOISTURE SOURCE BUT
NOT EXPECTING A LOT GIVEN FORCING EAST OF THE AREA. WEDNESDAY
HOWEVER...850MB TEMPS BEGIN TO DROP TO -6 TO -8C DURING THE DAY.
STILL...LES NOT INDICATED HOWEVER STILL THINK SNOW SHOWERS WILL
DEVELOP. WILL HAVE CHANCE POPS GOING TO LIKELY IN THE AFTERNOON.
WEDNESDAY NIGHT 850MB TEMPS DROP FURTHER TO -12C WITH ANOTHER
UPPER TROF CROSSING THE LAKE GIVEN THE ADDED DYNAMICS AM MORE
CONFIDENT IN SNOW SHOWERS ACROSS THE EAST LAKESHORE/SNOW
BELT...LASTING INTO EARLY THURSDAY.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH PRESSURE IS EXPECTED TO BE SHIFTING INTO THE EASTERN LAKES FRI
WHICH SHOULD BRING THE LAKE EFFECT SHSN TO AN END BY FRI NIGHT.
LITTLE ADDITIONAL ACCUMULATION IS LIKELY ON FRI.
THE MODELS START TO DIFFER INTO SAT ON WHERE AN UPPER LOW TRACKS
THUS AFFECTING THE TRACK OF A SURFACE LOW. THE GFS IS NOW SHOWING A
MUCH WEAKER SURFACE LOW WITH A BROAD AREA OF MOISTURE WORKING UP
THROUGH THE OH VALLEY MOSTLY FORCED BY THE UPPER TROUGH. THE ECMWF
HAS A MUCH STRONGER SOUTHERN STREAM UPPER LOW AND ASSOCIATED SURFACE
LOW. IN EITHER CASE THERE SHOULD BE PRECIP SPREADING NE ACROSS THE
CWA LATE SAT OR SAT NIGHT AND SHIFTING INTO MAINLY THE EAST SUN.
TEMPS ON THE EDGE FOR EITHER RAIN OR SNOW ON SAT BUT A LITTLE COLDER
AIR MOVING IN FOR SAT NIGHT AND SUN SHOULD LEAD TO MOSTLY SNOW THEN.
TEMPS DON`T LOOK TO GET COLD ENOUGH FOR LAKE EFFECT OF ANY
SIGNIFICANCE LATER SUN THEN HIGH PRESSURE IS EXPECTED TO MOVE OVER
THE AREA SUN NIGHT TO PROVIDE DRY CONDITIONS. ANOTHER UPPER TROUGH
IS PROGGED TO BE MOVING EAST INTO THE LAKE ERIE AREA BY LATE MON SO
THE DRY CONDITIONS MAY NOT LAST THRU THE DAY.
TEMPS DON`T APPEAR TO SHOW A LOT OF CHANGE SUN THRU MON.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
SOME LOW CLOUDS THAT WERE OVER NE OH AND NW PA HAVE JUST ABOUT
DECREASED. THE RAIN AREA WAS EXPANDING EAST. CONDITIONS WILL LOWER
TO MVFR AND THEN EVENTUALLY TO IFR ON TUESDAY AS THE FRONTAL
SYSTEM MOVES THROUGH. SOME QUESTION IF CONDITIONS WILL START TO
IMPROVE AS THE DRIER AIR WORKS IN TUESDAY NIGHT. THE MODELS DON`T
THINK SO. WILL TRY TO INCREASE THE CEILINGS SOME LATE.
.OUTLOOK...NON VFR INTO LATE TUE NIGHT AND ACROSS FAR NE OH/NW PA
ON WED AND THU IN LAKE EFFECT SNOW SHOWERS.
&&
.MARINE...
SE WINDS WILL START INCREASING TONIGHT AND VEER TO SW ON TUE THEN TO
WEST TUE NIGHT WHILE INCREASING TO 20 TO 30 KNOTS AS COLD AIR BEHIND
A SERIES OF COLD FRONTS SPREADS ACROSS THE AREA. THUS A SCA WILL BE
NEEDED STARTING TUE NIGHT. WEST TO NW WINDS WILL SLOWLY DECREASE
LATER WED THRU EARLY FRI SO THE SCA MAY HAVE TO BE UP UNTIL SOMETIME
THU NIGHT. HIGH PRESSURE OVER THE UPPER LAKES EARLY FRI WILL SETTLE
OVER THE NORTHERN PART OF THE LAKES FOR SAT WHILE A LOW TRACKS NE
ACROSS THE SE STATES TO THE DELMARVA AREA BY EARLY SUN. THIS SHOULD
LEAD TO AN INCREASING NE FLOW ON SAT...HOWEVER MODEL DIFFERENCES
MAKE IT UNCERTAIN WHETHER THE WINDS WILL GET INTO SCA CRITERIA.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...DJB/TK
SHORT TERM...TK
LONG TERM...ADAMS
AVIATION...KIELTYKA
MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
219 AM EST TUE DEC 16 2014
.SYNOPSIS...
SEASONAL TEMPERATURES WILL RETURN BEHIND A COLD FRONT WHICH WILL
PASS THROUGH ON TUESDAY EVENING. SCATTERED MOUNTAIN SNOW SHOWERS
ARE THEN EXPECTED FOR MID AND LATE WEEK. CONFIDENCE IS LOW
CONCERNING ALL DETAILS AND POTENTIAL IMPACTS ASSOCIATED WITH A LOW
PRESSURE SYSTEM EXPECTED TO TRACK NORTHEAST FROM THE GULF COAST
STATES OFF THE EAST COAST THIS WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
UPPER LOW SPINNING OVER NRN IL WILL FILL SLIGHTLY AND SLIDE
EASTWARD COVERING LWR MI BY EVENING. THE LARGER TROUGH WILL START
TO ABSORB THIS FEATURE. COMPLICATED FRONTAL FEATURES TO OUR WEST
WILL NOT SIMPLIFY MUCH AS THE SLIGHTLY DIFFERENT AIR MASS MOVES IN
LATER TODAY.
DESPITE +8C 8H TEMPS...WE ARE SEEING LITTLE BENEFIT FROM THESE
UNUSUALLY MILD TEMPS HERE AT THE SFC DUE TO LUDICROUS INVERSION.
LOW STRATUS STILL STUCK IN THE NE HALF OF THE AREA AND PATCHES IN
THE SOUTH AS WELL. THIS SHOULD NOT CHANGE MUCH UNTIL LATE
MORNING...WHEN SOME LARGER HOLES DUE TO SOME MIXING MAY APPEAR IN
THE EAST. FOG IS NOT DENSE ANYWHERE AT 07Z...BUT THE WINDWARD
SLOPES OF THE MTS MAY HAVE A LITTLE DRIZZLE. SUB FREEZING TEMPS IN
THE S...BUT THIS IS ALSO WHERE THERE ARE NO/LESS LOWER CLOUDS TO
MAKE SPRINKLES.
THE FIRST ARM OF SHOWERS ASSOCIATED WITH THIS COMPLEX
CIRCULATION/PATTERN WILL APPROACH THE AREA THIS MORNING...BUT
LATEST GUIDANCE CONTINUES TO HOLD IT OFF A LITTLE LATER.
THUS...WILL KEEP POPS LOW IN THE CENTRAL AND EAST FOR THE MORNING.
NOT UNTIL 14-15Z WILL PRECIP BE CERTAIN OVER THE WESTERN
MOUNTAINS. BUT ALL MODEL GUIDANCE MAKES NUMEROUS SHOWERS OR EVEN
MORE-WIDESPREAD COVERAGE OVER MOST IF NOT ALL OF THE AREA BY
20Z. DRY SLOT MOVES IN FROM THE SOUTHWEST...BUT WESTERLY FLOW
BEHIND THE OCCLUSION WILL KEEP LOTS OF CLOUD COVER AND SCT SHRA
OVER THE WEST LATER IN THE AFTN.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/...
UPPER PATTERN WOBBLES ITSELF INTO A BROAD UPPER LOW WITH A FEW
CLOSED CONTOURS OVER THE GREAT LAKES AND LOWER ONT/SRN QUE.
MOISTURE PULLED AROUND THE SYSTM AND PULLED FROM THE GREAT LAKES
WILL ASCEND THE WRN HIGHLANDS AND CREATE NUMEROUS SHOWERS FOR
TONIGHT. LESS COVERAGE WILL BE HAD LATER TONIGHT AND WEDNESDAY
MORNING...BUT SHOWERS WILL CONTINUE INTO WEDNESDAY AS THE UPPER
LOW CENTER SLIDES EAST AND THE COLDER AIR FILTERS IN. THIS SHOULD
TURN ANY SHOWERS OVER TO SNOW SHOWERS WED MORNING. DOWNSLOPE
SHOULD KEEP IT PARTLY TO MOSTLY SUNNY IN THE SE. SOME VERY LIGHT
ACCUMS COULD OCCUR ON THE WRN MTS. IT WILL GET KIND OF WINDY ON
WED - ESP IN THE LAURELS WHERE GUSTS COULD GET INTO THE 30S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
A RATHER POTENT SHORTWAVE TROUGH WILL PIVOT EASTWARD FROM THE
GREAT LAKES AND CROSS THE AREA WED NGT BEHIND THE DEPARTING
SURFACE LOW LIFTING SLOWLY NORTH FROM MAINE INTO NEW BRUNSWICK
CANADA. A REINFORCING SHOT OF COLD AIR ALOFT SHOULD ACCOMPANY THE
TRAILING SHORTWAVE WHICH MAY ACT TO BRIEFLY ENHANCE POST FRONTAL
LAKE EFFECT AND UPSLOPE SNOW SHOWERS OVER THE WESTERN HIGHLANDS.
ITS NOT OUT OF THE QUESTION THAT THE STRONG VORTMAX COULD INDUCE
SNOW SHOWERS EAST OF THE ALLEGHENY FRONT WED NGT HOWEVER THE
GLOBAL MODEL QPFS ARE NOT IN FAVOR OF THIS OUTCOME. DESPITE A
WELL ALIGNED WNW FLOW AND FAIRLY STRONG LOW LEVEL COLD AIR
ADVECTION...MODEL SOUNDINGS SHOW RATHER SHALLOW MOISTURE/LOW
INVERSION HGTS ALONG WITH DRY AIR WHICH SHOULD LIMIT MAX SNOW
ACCUM POTENTIAL (POTENTIAL FOR THIS MUCH OR WORST CASE) OVER THE
NW MTNS TO 2-3 INCHES BY THU MORNING...WITH AROUND 1 INCH ACCUM
THE MOST LIKELY OUTCOME. OVERALL THE GENERAL WEATHER TREND IN
CENTRAL PA WILL BE TOWARD A BRISK AND COLDER PATTERN WED THRU FRI.
LARGE SCALE SUBSIDENCE ASSOCIATED WITH SURFACE HIGH EXTENDING
FROM THE GREAT LAKES INTO EASTERN CANADA SHOULD BRING AN END TO
NUISANCE SNOW SHOWER ACTIVITY BY FRI NGT.
CONCERNING THE POTENTIAL WEEKEND STORM...
THERE IS BROAD MODEL CONSENSUS IN A SURFACE LOW DEVELOPING OVER
THE GULF COAST REGION AND TRACKING NORTHEAST OFF THE EAST COAST
THIS WEEKEND. HOWEVER...THERE CONTINUES TO BE A WIDE RANGE OF
POSSIBLE SOLUTIONS WITH ABOVE AVERAGE SPREAD IN THE LOW TRACK.
IN ADDITION TO THE LARGE SPREAD...THERE HAVE BEEN RUN-TO-RUN
[IN]CONSISTENCY ISSUES THAT CONTINUE TO PLAGUE THE MODEL FCSTS
IN PARTICULAR TODAYS 15/12Z RUN OF THE DETERMINISTIC ECMWF WHICH
HAS BACKED OFF ON ITS BULLISH WINTER STORM SCENARIO THAT IT HAS
BEEN ADVERTISING FOR THE PREVIOUS 4 CYCLES. CURIOUSLY BOTH THE
GEFS AND ECENS SEEM TO BE LEANING MORE IN FAVOR OF A LOW TRACK
CLOSER TO THE COAST - WITH A MEAN POSITION WEST OF THEIR
RESPSECTIVE DETERMINISTIC MODEL CORES. WITH THE STORM STILL 5-6
DAYS OUT THERE IS A LOT OF TIME FOR THE FORECAST TO CHANGE.
CONFIDENCE IS LOW REGARDING ANY POTENTIAL DETAILS OR IMPACTS WITH
THIS SYSTEM. HIGH PRESSURE SHOULD BUILD INTO THE AREA EARLY NEXT
WEEK.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
COMPLEX FCST OVERNIGHT INTO TUE...GIVEN THAT SOME AREAS ARE
CLEAR WITH FOG FORMING...OTHERS MAY STAY CLEAR...AND LOW
CLDS STILL IN PLACE ACROSS PORTIONS OF THE AREA.
OTHER CONCERN IS THE FORMATION OF ICE IN AREAS THAT ARE
CLEAR...GIVEN LIGHT WINDS AND HIGH HUMIDITY LEVELS.
06Z TAFS SENT.
EARLIER DISCUSSION BELOW.
SATL IMAGERY SHOWS LOW CLOUDS HAVE CLEARED ACROSS SOUTHERN PA
EARLY THIS EVENING. THIS CLEARING TREND IS EXPECTED TO WORK SLOWLY
NORTHWARD OVERNIGHT...AS INVERSION HGT FALLS. HOWEVER...THE
CLEARING SKY...COMBINED WITH A NEARLY CALM WIND AND LOW DWPT
DEPRESSIONS...WILL LEAD TO AREAS OF FOG OVER THE EASTERN HALF OF
THE STATE. LATEST HRRR OUTPUT SUGGESTS KIPT SOUTH THRU KMDT AND
KLNS STAND THE BEST CHC OF IFR VSBYS LATE TONIGHT. INCREASING
HIGH CLOUDS AND SERLY BREEZE SHOULD LIMIT THE FOG FORMATION AT
KJST. ACROSS THE NW MTNS...MDL SOUNDINGS/SREF OUTPUT SUPPORT
LINGERING IFR CONDS AT KBFD THRU THE NIGHT.
A LOW PRESSURE SYSTEM TRACKING WEST OF PENNSYLVANIA WILL BRING A
PERIOD OF RAIN SHOWERS TUESDAY. SIGNIFICANT REDUCTIONS REMAIN
LIKELY...ESP AT KBFD WHERE MOIST SOUTHERLY FLOW ASCENDING THE MTNS
WILL LIKELY PRODUCE IFR CONDS THRU THE DAY. MAIN PRECIP WILL MOVE
OUT TUE EVE...BUT LIGHT WIND AND LINGERING LOW LVL MOISTURE COULD
RESULT IN REDUCED VSBYS FROM FOG THRU TUE EVENING.
OUTLOOK...
WED...LOW CIGS/SHSNRA LIKELY W MTNS...MAINLY AM.
THU-FRI...NO SIG WX EXPECTED.
SAT...SNOW/REDUCED VSBY POSS SOUTHERN PA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1253 AM EST TUE DEC 16 2014
.SYNOPSIS...
SEASONAL TEMPERATURES WILL RETURN BEHIND A COLD FRONT WHICH WILL
PASS THROUGH ON TUESDAY EVENING. SCATTERED MOUNTAIN SNOW SHOWERS
ARE THEN EXPECTED FOR MID AND LATE WEEK. CONFIDENCE IS LOW
CONCERNING ALL DETAILS AND POTENTIAL IMPACTS ASSOCIATED WITH A LOW
PRESSURE SYSTEM EXPECTED TO TRACK NORTHEAST FROM THE GULF COAST
STATES OFF THE EAST COAST THIS WEEKEND.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
10 PM UPDATE...
TWEAKINGS OF SKY BASED ON RECENT OBS DEPICTING A RELUCTANTLY RECEDING
REGION OF RELATIVELY HIGH RELATIVE HUMIDITY ALOFT. BUT HIGH CLOUDS
ALREADY RIDING OVER THE AREAS WHICH DID CLEAR OUT IN THE LOW
LEVELS. TEMPS DROPPED QUICKLY IN THE CLEAR AND CALM AREAS IN THE
SOUTH...SO SOME TWEAKS TO TEMPS HAVE BEEN MADE AS WELL. MOST MESO
MODELS MEANDER THE MUCH-ANTICIPATED MOISTURE/SHOWERS. SO...A
SLIGHT TWEAK LATER IN TIMING HAS ALSO BEEN MADE.
PREV...
A RIDGE OF HIGH PRESSURE WILL DRIFT OFF THE EAST COAST TONIGHT.
INCREASING SOUTH TO SOUTHWESTERLY FLOW OVER PENN /AT 925 MB AND
850 MB RESPECTIVELY/ WAS HELPING TO ERODE THE SOUTHERN EDGE OF
THE EXTENSIVE STRATUS/STRATOCU ACROSS SCENT PENN AND THE LOWER
SUSQ VALLEY REGION.
LIGHTER WINDS AND BROAD DIFFLUENCE AT BOTH LEVELS ACROSS THE
NORTHERN THIRD TO HALF OF THE STATE WILL HELP TO MAINTAIN THE
LOWER CLOUD DECK THERE THROUGH THE OVERNIGHT HOURS BENEATH CIRRUS
OF VARYING THICKNESS STREAMING NE FROM THE OHIO RIVER VALLEY.
COOLEST TEMPS TONIGHT MAY BE FOUND ACROSS THE SCENT ZONES AND
PORTIONS OF THE LOWER SUSQ VALLEY WHERE MAINLY CLEAR SKIES AND
SLIGHTLY COOLER SFC DEWPOINTS AROUND 32F WILL YIELD LATE EVENING
LOWS IN THE LOWER 30S. TEMPS WILL BE SIMILAR IF NOT A DEG OR 2
HIGHER ACRS THE NRN MTNS...WHERE CLOUDS...SLIGHTLY HIGHER
DEWPOINTS WILL BE FOUND.
THE CENTRAL MTNS AND LAURELS WILL HAVE LOWS 2-4 DEG F HIGHER THAN
ELSEWHERE ACROSS THE NORTH...AND SOUTH.
PRECIP IN THE FORM OF SHOWERS DOESN/T KNOCK ON OUR WESTERN
DOORSTEP UNTIL 10-12Z TUESDAY.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
SHORT RANGE GUIDANCE REMAINS IN VERY GOOD AGREEMENT WITH BRINGING
A WEAKENING LOW PRESSURE AREA AND OCCLUSION/COLD FRONT THROUGH
THE AREA TUESDAY. MODELS DISAGREE A BIT ON PRECIP TOTALS...BUT
WITH IT ALL BEING RAIN IT WON/T MATTER TOO MUCH. AMOUNTS LOOK TO
RANGE FROM A TENTH OR TWO ACROSS THE SE TO A MAX OF MAYBE HALF AN
INCH IN THE NORTH. THOUGH IT WILL BE MILD FOR MID DECEMBER...CLOUDS
AND SHOWERS SHOULD HOLD TEMPS IN THE 40S.
MAIN PRECIP LIFTS NE TUE EVE AS MAIN TROUGH LIFTS OUT. ANOTHER
SHORTWAVE ROTATES IN FROM THE GREAT LAKES QUICKLY BEHIND...TURNING
FLOW W/NW AND PUSHING AN AREA OF SOMEWHAT COLDER AIR BACK INTO PA.
FLOW LOOKS TO ALIGN ENOUGH WITH THE LAKES TO GENERATE SOME SNOW
SHOWERS IN THE NW MTNS...WHICH WILL BRING MAINLY LIGHT
ACCUMS...THOUGH BANDS OF A COUPLE INCHES OF ACCUM IS POSS IN
PORTIONS OF MAINLY NW WARREN COUNTY. OROGRAPHIC FLOW OVER WESTERN
AND NORTHERN HIGHER TERRAIN WILL BRING LIGHT SCT SNOW SHOWERS DOWN
TO A KAOO-KUNV-KIPT LINE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
A RATHER POTENT SHORTWAVE TROUGH WILL PIVOT EASTWARD FROM THE
GREAT LAKES AND CROSS THE AREA WED NGT BEHIND THE DEPARTING
SURFACE LOW LIFTING SLOWLY NORTH FROM MAINE INTO NEW BRUNSWICK
CANADA. A REINFORCING SHOT OF COLD AIR ALOFT SHOULD ACCOMPANY THE
TRAILING SHORTWAVE WHICH MAY ACT TO BRIEFLY ENHANCE POST FRONTAL
LAKE EFFECT AND UPSLOPE SNOW SHOWERS OVER THE WESTERN HIGHLANDS.
ITS NOT OUT OF THE QUESTION THAT THE STRONG VORTMAX COULD INDUCE
SNOW SHOWERS EAST OF THE ALLEGHENY FRONT WED NGT HOWEVER THE
GLOBAL MODEL QPFS ARE NOT IN FAVOR OF THIS OUTCOME. DESPITE A
WELL ALIGNED WNW FLOW AND FAIRLY STRONG LOW LEVEL COLD AIR
ADVECTION...MODEL SOUNDINGS SHOW RATHER SHALLOW MOISTURE/LOW
INVERSION HGTS ALONG WITH DRY AIR WHICH SHOULD LIMIT MAX SNOW
ACCUM POTENTIAL (POTENTIAL FOR THIS MUCH OR WORST CASE) OVER THE
NW MTNS TO 2-3 INCHES BY THU MORNING...WITH AROUND 1 INCH ACCUM
THE MOST LIKELY OUTCOME. OVERALL THE GENERAL WEATHER TREND IN
CENTRAL PA WILL BE TOWARD A BRISK AND COLDER PATTERN WED THRU FRI.
LARGE SCALE SUBSIDENCE ASSOCIATED WITH SURFACE HIGH EXTENDING
FROM THE GREAT LAKES INTO EASTERN CANADA SHOULD BRING AN END TO
NUISANCE SNOW SHOWER ACTIVITY BY FRI NGT.
CONCERNING THE POTENTIAL WEEKEND STORM...
THERE IS BROAD MODEL CONSENSUS IN A SURFACE LOW DEVELOPING OVER
THE GULF COAST REGION AND TRACKING NORTHEAST OFF THE EAST COAST
THIS WEEKEND. HOWEVER...THERE CONTINUES TO BE A WIDE RANGE OF
POSSIBLE SOLUTIONS WITH ABOVE AVERAGE SPREAD IN THE LOW TRACK.
IN ADDITION TO THE LARGE SPREAD...THERE HAVE BEEN RUN-TO-RUN
[IN]CONSISTENCY ISSUES THAT CONTINUE TO PLAGUE THE MODEL FCSTS
IN PARTICULAR TODAYS 15/12Z RUN OF THE DETERMINISTIC ECMWF WHICH
HAS BACKED OFF ON ITS BULLISH WINTER STORM SCENARIO THAT IT HAS
BEEN ADVERTISING FOR THE PREVIOUS 4 CYCLES. CURIOUSLY BOTH THE
GEFS AND ECENS SEEM TO BE LEANING MORE IN FAVOR OF A LOW TRACK
CLOSER TO THE COAST - WITH A MEAN POSITION WEST OF THEIR
RESPSECTIVE DETERMINISTIC MODEL CORES. WITH THE STORM STILL 5-6
DAYS OUT THERE IS A LOT OF TIME FOR THE FORECAST TO CHANGE.
CONFIDENCE IS LOW REGARDING ANY POTENTIAL DETAILS OR IMPACTS WITH
THIS SYSTEM. HIGH PRESSURE SHOULD BUILD INTO THE AREA EARLY NEXT
WEEK.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
COMPLEX FCST OVERNIGHT INTO TUE...GIVEN THAT SOME AREAS ARE
CLEAR WITH FOG FORMING...OTHERS MAY STAY CLEAR...AND LOW
CLDS STILL IN PLACE ACROSS PORTIONS OF THE AREA.
OTHER CONCERN IS THE FORMATION OF ICE IN AREAS THAT ARE
CLEAR...GIVEN LIGHT WINDS AND HIGH HUMIDITY LEVELS.
06Z TAFS SENT.
EARLIER DISCUSSION BELOW.
SATL IMAGERY SHOWS LOW CLOUDS HAVE CLEARED ACROSS SOUTHERN PA
EARLY THIS EVENING. THIS CLEARING TREND IS EXPECTED TO WORK SLOWLY
NORTHWARD OVERNIGHT...AS INVERSION HGT FALLS. HOWEVER...THE
CLEARING SKY...COMBINED WITH A NEARLY CALM WIND AND LOW DWPT
DEPRESSIONS...WILL LEAD TO AREAS OF FOG OVER THE EASTERN HALF OF
THE STATE. LATEST HRRR OUTPUT SUGGESTS KIPT SOUTH THRU KMDT AND
KLNS STAND THE BEST CHC OF IFR VSBYS LATE TONIGHT. INCREASING
HIGH CLOUDS AND SERLY BREEZE SHOULD LIMIT THE FOG FORMATION AT
KJST. ACROSS THE NW MTNS...MDL SOUNDINGS/SREF OUTPUT SUPPORT
LINGERING IFR CONDS AT KBFD THRU THE NIGHT.
A LOW PRESSURE SYSTEM TRACKING WEST OF PENNSYLVANIA WILL BRING A
PERIOD OF RAIN SHOWERS TUESDAY. SIGNIFICANT REDUCTIONS REMAIN
LIKELY...ESP AT KBFD WHERE MOIST SOUTHERLY FLOW ASCENDING THE MTNS
WILL LIKELY PRODUCE IFR CONDS THRU THE DAY. MAIN PRECIP WILL MOVE
OUT TUE EVE...BUT LIGHT WIND AND LINGERING LOW LVL MOISTURE COULD
RESULT IN REDUCED VSBYS FROM FOG THRU TUE EVENING.
OUTLOOK...
WED...LOW CIGS/SHSNRA LIKELY W MTNS...MAINLY AM.
THU-FRI...NO SIG WX EXPECTED.
SAT...SNOW/REDUCED VSBY POSS SOUTHERN PA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT/RXR
NEAR TERM...DANGELO/LAMBERT/RXR
SHORT TERM...
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/MARTIN
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
919 PM MST MON DEC 15 2014
.SHORT TERM...THIS EVENING THROUGH TUESDAY NIGHT
ISSUED AT 213 PM MST MON DEC 15 2014
UPPER LEVEL ANALYSIS HAS LOW CENTER OVER IOWA SLIDING NORTHEAST.
UPPER RIDGE IS SLOWLY BUILDING ACROSS THE ROCKIES AS EAST PACIFIC
TROF APPROACHES THE WEST COAST. SKIES ACROSS THE NORTHERN PLAINS
RANGE FROM MOSTLY SUNNY OVER WESTERN AREAS...TO CLOUDY WITH LIGHT
SNOW FROM THE CENTRAL DAKOTAS EAST. AT THE SURFACE...CANADIAN
HIGH PRESSURE CONTINUES TO SLIDE SOUTH INTO THE AREA. NORTHWEST
WINDS CONTINUE TO BE QUITE BREEZY...WITH WINDS JUST BEGINNING TO
SLACKEN ACROSS NORTHEAST WYOMING. TEMPERATURES AT 2 PM ARE IN THE
20S.
TONIGHT...DRY AIR MOVES IN QUICKLY TONIGHT BEHIND THE EXITING
SYSTEM...AND PRECIP WILL END ACROSS SOUTH CENTRAL SOUTH DAKOTA BY
EARLY EVENING. HOWEVER...SOME AREAS OF CLOUDS AND SOME PATCHY FOG
WILL STICK AROUND THROUGH THE NIGHT. WITH MAINLY PARTLY CLOUDY
CONDITIONS OVERNIGHT...LOW TEMPERATURES WILL FALL INTO THE SINGLE
DIGITS AND TEENS.
TUESDAY...WESTERN UPPER RIDGE WILL CROSS THE NORTHERN PLAINS AS
THE CANADIAN SURFACE HIGH SHIFTS INTO THE EASTERN DAKOTAS. NORTH
WINDS WILL BE LIGHT...AND SLOWLY SHIFT AROUND OUT OF THE SOUTH BY
LATE AFTERNOON. HIGHS WILL BE IN THE 20S TO LOWER 30S...WITH LOWS
TUESDAY NIGHT AROUND 10 TO 20. SKIES WILL BECOME CLOUDIER
OVERNIGHT AHEAD OF AN APPROACHING UPPER TROUGH.
.LONG TERM...WEDNESDAY THROUGH MONDAY
ISSUED AT 213 PM MST MON DEC 15 2014
PROGRESSIVE SPLIT FLOW PATTERN TO PERSIST THROUGH THE LONG TERM
PERIOD. MAINLY DRY WX EXPECTED THROUGH THE PERIOD GIVEN TROUGH RE-
LOADING IN THE WESTERN CONUS. HOWEVER...ANOTHER STRONG SOUTHERN
PERIPHERY UPPER TROUGH WILL EJECT OUT OF THE SW CONUS IN THE THU-
FRI PERIOD. FORECAST MODELS ARE NOW LATCHING ONTO THE EJECTION OF
A PRIMARY FRONT SIDE IMPULSE. THIS SYSTEM WOULD BRING A SMALL
CHANCE FOR LIGHT SNOW ACROSS THE FAR NW FA WED AS IT INTERACTS
WITH THE LL BAROCLINIC ZONE IN PLACE. THIS SYSTEM IS PRESENT IN
ALL FORECAST MODELS ALTHOUGH THE TRACK IS STILL IN QUESTION.
INCLUDED A LOW POP ACROSS THE NW WED FOR THIS. THE MAIN SW CONUS
UPPER TROUGH CONTINUES TO BE ADVERTISED TO TRACK JUST SOUTH OF THE
FA TOWARD THE END OF THE WEEK. IF ANY NORTHERN STREAM IMPULSES
TEND TO PHASE WITH THIS SYSTEM...A TRACK FARTHER NW COULD STILL BE
POSSIBLE...WHICH COULD BRING SOME CHANCES FOR SNOW TO SCENTRAL
AREAS ONCE AGAIN TOWARD FRIDAY-SAT. TENDENCIES FOR ANOTHER STRONG
WESTERN NOAM RIDGE REMAIN PRESENT IN MEAN ENSEMBLES AND
DETERMINISTIC SOLUTIONS PER ANOTHER EXTENSION OF THE EAST ASIAN
UPPER JET. THIS COULD SPELL MUCH WARMER CONDITIONS FOR THE
FOLLOWING WEEK IF THE RIDGE BIASES EAST AS IT HAS IN THIS PATTERN.
HOWEVER...CURRENT LONG RANGE ECMWF/GFS RUNS STILL SUPPORT A CLOSED
LOW IN THE PACIFIC NEAR HAWAII WITH A DOMINATE NORTHERN
STREAM...UNCHARACTERISTIC OF THE CURRENT REGIME. THE 12Z ECMWF HAS
NOW SHIFTED THE RIDGE SLIGHTLY NE WITH THE BAROCLINIC ZONE RIGHT
ON TOP OF THE FA. THIS HEIGHT PATTERN LOOKS VERY SIMILAR TO THE
THANKSGIVING DAY PATTERN 7-10 DAYS OUT WITH A LARGE RANGE IN TEMPS
AMONG DETERMINISTIC SOLUTIONS MID NEXT WEEK.
GIVEN STRONGER PROGRESSIVE TENDENCIES...FORECAST MODELS SUPPORT
WARMER WESTERLY FLOW INTO THE REGION A LITTLE EARLIER THAN BEFORE.
HENCE...HAVE WARMED TEMPS SOME IN THE LATTER PORTION OF THE PERIOD.
OTHERWISE...NO OTHER SIG CHANGES TO THE FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 911 PM MST MON DEC 15 2014
WIDESPREAD MVFR/LOCAL IFR CONDS INTO TUE AFTERNOON. MVFR CIGS
WILL REMAIN THROUGH MUCH OF THE PERIOD. FURTHER WEST...CLEAR SKIES
WILL LIKELY REMAIN OVER THE BLACK HILLS. HOWEVER...MVFR CIGS ARE
EXPECTED TO STRADDLE THE RAP TERMINAL GIVEN MOIST NW
FLOW...CONFIRMED IN HIRES GUIDANCE. THERE IS THE POTENTIAL FOR
PARTIAL CLEARING AT THE RAP TERMINAL. HOWEVER...HIGHEST
CONFIDENCE IS IN CONTINUED MVFR CIGS. LOW CIGS OVER THE WY PLAINS
WILL LIKELY LINGER INTO LATE TUE MORNING UNTIL DRY LL SOUTHERLY
FLOW CAN BECOME ESTABLISHED. SOME PATCHY FOG IS ALSO POSSIBLE
THERE. RAP MODEL INDICATES POTENTIAL CLEARING EARLIER...HOWEVER
CONFIDENCE IN THIS REMAINS LOW GIVEN HIRES GUIDANCE. WILL KEEP
WITH IFR CIGS ATTM MONITORING TRENDS FOR POTENTIAL AMENDMENTS.
CIGS WILL BE DIFFICULT LATE IN THE PERIOD TUE AFTERNOON AS THE SFC
RIDGE AXIS WILL BE OVER THE FA. THIS WILL LIKELY HINDER STRATUS
MIX OUT WITH MANY PLACES LIKELY SEEING AT LEAST MVFR CIGS THROUGH
MUCH OF TUE.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...15
LONG TERM...JC
AVIATION...JC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1037 PM MST MON DEC 15 2014
.UPDATE...
ISSUED AT 815 PM MST MON DEC 15 2014
VERY TRICKY TEMPERATURE FORECAST FOR TONIGHT. LATEST FOG/STRATUS
SATELLITE LOOP AND AIRPORT OBSERVATIONS SHOW A LLVL STRATUS DECK
DRAPED FROM EAST CENTRAL WY SOUTHEASTWARD TOWARD ALLIANCE IN THE
NEBRASKA PANHANDLE. UPSTREAM SFC OBS AND HIGH-RES MODELS WOULD
SUGGEST BLYR MOISTURE WILL REMAIN HIGH FOR MUCH OF THE OVERNIGHT
PERIOD VIA LIGHT NORTHWEST WINDS. LATEST RUNS OF THE HRRR HANG ON
TO THE STRATUS THROUGH SUNRISE TUE. SO DESPITE SEVERAL INCHES OF
FRESH SNOW...THIS WILL HAVE AN IMPACT ON TEMPS. OPTED TO RAISE
LOWS A FEW DEGREES. DID NOT GO AS HIGH AS THE HRRR/RAP YET IN CASE
CLOUDS ACTUALLY DO CLEAR OUT. COULD SEE SOME PATCHY FOG WITH THE
ENHANCED NEAR-SFC MOISTURE...ESPECIALLY OVER THE WESTERN NEBRASKA
PANHANDLE. WILL CONTINUE TO MONITOR TRENDS THROUGH THE EVENING FOR
ANY ADDITIONAL UPDATES.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 335 PM MST MON DEC 15 2014
MID AFTERNOON WATER VAPOR IMAGERY SHOWED THE STACKED LOW PRESSURE
SYSTEM THAT BROUGHT HEAVY SNOW AND GUSTY NORTHWEST WINDS TO THE
HIGH PLAINS WAS TRACKING EAST ACROSS THE MISSOURI VALLEY.
REGIONAL RADAR...SURFACE OBSERVATIONS AND HIGHWAY WEB CAMS
REVEALED SLOWLY IMPROVING CONDITIONS ACROSS THE WESTERN NEBRASKA
PANHANDLE. RECENTLY CANCELLED THE WINTER STORM WARNING AND WEATHER
ADVISORY THAT WAS IN EFFECT UNTIL 3 PM. GUSTY NORTHWEST WINDS OF
25 TO 35 MPH WILL DECREASE LATER THIS AFTERNOON AND EARLY EVENING.
SNOW HAS TAPERED OFF TO FLURRIES OVER THE SOUTHERN NEBRASKA
PANHANDLE. TEMPERATURES WILL CHILLY WITH READINGS IN THE 20S AND
30S...AND WIND CHILLS IN THE SINGLE DIGITS AND TEENS.
LATEST NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT WITH THE LARGE
SCALE PATTERN. THE STORM SYSTEM OVER THE MIDWEST WILL CONTINUE ITS
EASTWARD TREK ACROSS OHIO VALLEY INTO NEW ENGLAND TUESDAY...WITH A
SECONDARY PIECE OF ENERGY ROTATING THROUGH THE GREAT LAKES. MEANWHILE...
A SHORTWAVE RIDGE WILL SLIDE EAST ACROSS THE FRONT RANGE AND HIGH
PLAINS THROUGH TUESDAY NIGHT...AS THE NEXT PACIFIC TROUGH MOVES
THROUGH THE SOUTHERN GREAT BASIN AND FOUR CORNERS REGION WEDNESDAY.
A WEAKER PRESSURE GRADIENT WILL RESULT IN LIGHTER WINDS DURING THE
SHORT TERM.
WITH PARTIAL CLEARING...LIGHT WINDS AND MOIST BOUNDARY LAYER ACROSS
THE HIGH PLAINS...CONCERN WILL BE PATCHY FOG DEVELOPMENT WITH
STRENGTHENING LOW LEVEL INVERSION. DUE TO FRESH SNOW
PACK...TRENDED CLOSER TO THE COLDER MAVMOS FOR MIN TEMPERATURES
TONIGHT...WITH WIDESPREAD SINGLE DIGITS FOR THE HIGH PLAINS AND
VALLEYS OF SOUTHEAST WY. A FEW LOCATIONS IN THE WESTERN PANHANDLE
COULD DROP TO AROUND 0 DEGREES. THERE WILL BE ENOUGH OF A WESTERLY
WIND COMPONENT TO KEEP TEMPERATURES IN THE LOWER TEENS ELSEWHERE.
INCREASING MID/UPPER LEVEL MOISTURE WILL SPREAD FROM SOUTHWEST TO
NORTHEAST TUESDAY WITH THE APPROACH AND PASSAGE OF THE RIDGE.
THERE WILL BE SOME MOISTURE AND WEAK UPSLOPE FOR LIGHT SNOW OVER
THE SOUTHERN MOUNTAINS. HIGH TEMPERATURES TUESDAY WILL SLIGHTLY
BELOW SEASONAL NORMALS WITH 20S AND 30S. TUESDAY NIGHT WILL NOT BE
AS COLD WITH A MORE SOUTHWESTERLY WIND COMPONENT AND CLOUD COVER
KEEPING MIN TEMPERATURES MOSTLY IN THE TEENS TO AROUND 20. SOME
UPPER SINGLE DIGITS WILL BE POSSIBLE FOR PORTIONS OF THE WESTERN
PANHANDLE. WEDNESDAY WILL BE A CARBON COPY OF TUESDAY WITH MOSTLY
CLOUDY SKIES...COOL TEMPERATURES AND LIGHT OROGRAPHIC SNOWFALL FOR
THE SOUTHERN MOUNTAINS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 258 PM MST MON DEC 15 2014
WEDNESDAY NIGHT/THURSDAY...RATHER MOIST WESTERLY FLOW ALOFT WILL
CONTINUE THE SCATTERED SNOW SHOWERS OVER OUR SNOWY AND SIERRA MADRE
RANGES...DRY ELSEWHERE.
FRIDAY...PRIMARY SHORTWAVE TROUGH ALOFT MOVES ACROSS OUR COUNTIES
WITH DECREASING COVERAGE OF SHOWERS IN THE AFTERNOON...THOUGH IT
WILL BE BREEZY TO WINDY PER PROGGED LOW AND MID LEVEL GRADIENTS.
SATURDAY...CONTINUED BREEZY TO WINDY PER PROGGED LOW AND MID LEVEL
GRADIENTS. SHOULD BE DRY WITH LIMITED LOW AND MID LEVEL MOISTURE AND
LIFT...THOUGH WITH PERIODS OF MIDDLE AND HIGH CLOUDS.
SUNDAY...WINDY PERIOD DEVELOPS WITH STRONG NORTHWEST FLOW ALOFT AND
PROGGED LOW AND MID LEVEL GRADIENTS INCREASING
MONDAY...EVEN WINDIER AS THE PROGGED LOW AND MID LEVEL GRADIENTS
INCREASE SIGNIFICANTLY WITH NORTHWEST FLOW ALOFT. LOOKS LIKE ENOUGH
MID LEVEL MOISTURE FOR SCATTERED OROGRAPHIC SNOW SHOWERS OVER THE
SNOWY AND SIERRA MADRE RANGES...DRY ELSEWHERE. SEASONABLE
TEMPERATURES...THOUGH STILL QUITE WINDY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1027 PM MST MON DEC 15 2014
LOW STRATUS OVER EAST CENTRAL WYOMING AND THE NORTHERN NEBRASKA
PANHANDLE WILL CONTINUE TO RESULT IN MVFR CIGS AT KCDR AND KAIA
OVERNIGHT. AMPLE NEAR-SURFACE MOISTURE FROM FRESH SNOWPACK WILL
CREATE THE POTENTIAL FOR IFR VSBYS IN FOG OVER NORTHERN PORTIONS
OF THE PANHANDLE THROUGH AT LEAST 15Z TUE. BRIEF MVFR/IFR CONDS
WILL BE POSSIBLE OVER SOUTHEAST WY WITH SNOW SHOWERS BETWEEN 18Z
TUE AND 00Z WED. WINDS WILL GENERALLY BE LIGHT.
&&
.FIRE WEATHER...
ISSUED AT 300 PM MST MON DEC 15 2014
NO CONCERNS ANTICIPATED THROUGH MID WEEK WITH WIDESPREAD SNOW
COVER...COOL TEMPERATURES...LIGHTER WINDS AND HIGH RELATIVE
HUMIDITIES.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLH
SHORT TERM...MJ
LONG TERM...SAR
AVIATION...CLH
FIRE WEATHER...MJ
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
410 AM PST TUE DEC 16 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE COAST THIS MORNING AND SPREAD RAIN
SHOWERS ALONG THE COAST...PUSHING INLAND THIS AFTERNOON. THERE
WILL ALSO BE A SLIGHT CHANCE OF THUNDERSTORMS. ACCUMULATING SNOW
WILL BE POSSIBLE IN THE HIGH MOUNTAINS. A SECOND...STRONGER STORM
WILL BRING MORE SHOWERS ON WEDNESDAY...HEAVY AT TIMES. THE SECOND
STORM WILL ALSO FILTER IN SOME COOLER AIR AND LOWER SNOW LEVELS TO
BETWEEN 5000 TO 6000 FEET WEDNESDAY. SEVERAL INCHES OF SNOW ARE
EXPECTED ABOVE 6000 FEET. DRY WITH A WARMING TREND THURSDAY
AFTERNOON THROUGH FRIDAY. A WEAK TROUGH MAY PRODUCE SCATTERED
LIGHT SHOWERS ON SATURDAY. WARMER AGAIN WITH DRY OFFSHORE FLOW
EARLY NEXT WEEK.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
WELL...SHOWERS OFFSHORE PETERED OUT AROUND MIDNIGHT BEFORE THEY
MADE IT TO THE COASTLINE. HOWEVER ANOTHER BATCH OF RAIN SHOWERS
ARE BECOMING EVIDENT ON RADAR AND SATELLITE WELL OFFSHORE...SOUTH
OF SAN CLEMENTE ISLAND...AND ARE EXPECTED TO MOVE TO JUST OFFSHORE
AFTER DAYBREAK THIS MORNING...COINCIDENT WITH A DECAYING COLD
FRONT. THESE SHOWERS MAY BECOME BETTER ORGANIZED TOWARDS MIDDAY
WITH A BIT OF DIURNAL HEATING MOVING ONTO THE COAST AND SPREAD
INLAND TO THE MOUNTAINS. THE HIGH RESOLUTION WRF AND ESPECIALLY
THE HRRR BOTH INDICATE A THIN BAND OF SURFACE INSTABILITY (CAPE
VALUES AS HIGH AS 1000 J/KG) BETWEEN 18Z-00Z. NOT SURE HOW FAR
INLAND THIS BAND WILL MAKE IT BUT FOR NOW INDICATED SLIGHT CHANCE
OF THUNDERSTORMS ALL THE WAY TO THE INLAND MOUNTAINS. BRIEF HEAVY
BURSTS OF RAIN MOST LIKELY THIS AFTERNOON WITH ANY STRONGER CELLS
THAT DO FORM...THEREFORE WILL CONTINUE THE FLASH FLOOD WATCH WHICH
BECOMES IN FORCE THIS AFTERNOON THROUGH WEDNESDAY AFTN.
AFTER 00Z THE COLD FRONT WILL LIKELY WASH OUT INLAND AND SHOWERS
WILL DIMINISH IF NOT DISSIPATE EXCEPT FOR SOME LINGERING SHOWERS
IN THE MOUNTAINS THROUGH THE EVENING.
A STRONGER SYSTEM WITH A SURFACE LOW PRESSURE WAVE IS EXPECTED TO
APPROACH OUR REGION EARLY WEDNESDAY MORNING FROM THE NW. THIS
FEATURE IS STILL EXPECTED TO BRING MORE WIDESPREAD PRECIPITATION
ALONG WITH A BIT OF COLDER AIR TO THE MOUNTAINS. THE LATEST MODELS
ARE NOT QUITE AS STRONG WITH THE COLDER AIR BUT WITH CONVECTION
WEDNESDAY AFTERNOON COULD STILL SEE SOME TEMPORARY LOWERING OF THE
WET BULB ZERO BELOW 6000 FEET DUE TO STRONGER CONVECTION...BRINGING
ACCUMULATING SNOW TO THE MOUNTAINS...INCLUDING THE HIGHER PEAKS IN
SAN DIEGO COUNTY. NEW RAINFALL AMOUNTS ON WEDNESDAY ARE EXPECTED
TO BE BETWEEN ONE-HALF TO ONE INCH FOR THE COAST AND
VALLEYS...AND BETWEEN ONE TO TWO INCHES FOR THE MOUNTAINS...AND
AROUND ONE-HALF INCH OR LESS FOR THE DESERTS.
SHOWERS WILL LINGER IN THE MOUNTAINS WEDNESDAY NIGHT. RIDGING
ENSUES WITH MILDER AND DRIER WEATHER FOR THURSDAY AND FRIDAY. A
WEAK UPPER LEVEL TROUGH IS STILL INDICATED BY THE MODELS TO PASS
OVERHEAD FRIDAY NIGHT INTO SATURDAY MORNING...WHERE WE HAVE
CONTINUED TO INDICATE JUST A SLIGHT CHANCE OF SHOWERS. AFTER
SATURDAY...A LARGE AREA OF HIGH PRESSURE WILL SETUP ACROSS THE
EASTERN PACIFIC AND SOUTHWEST CALIFORNIA...BRINGING MUCH WARMER
TEMPERATURES AND SUNNY SKIES THROUGH EARLY NEXT WEEK.
&&
.AVIATION...
161000Z...COAST/VALLEYS/MOUNTAINS...CLOUDS WITH BASES VARYING
BETWEEN 3000 FEET MSL AND 8000 FEET MSL AND ISOLATED -SHRA TODAY
THROUGH THE EVENING. BETWEEN 15-20Z MORE PROBABLE SHOWERS AND MORE
WIDESPREAD CIGS 2500-3000 FEET MSL. AFTER 09Z LATE TONIGHT RAIN WITH
A FEW THUNDERSTORMS AND CIGS OF 2000 FEET MSL. HEAVIER RAIN WILL
DROP CIGS BELOW 2000 FEET MSL AND VIS 2-5SM. DESERTS...VARIABLE
CLOUDS AOA 8000 FEET MSL TODAY...LOWERING LATE TONIGHT.
&&
.MARINE...
200 AM...A WEAK COLD FRONT WILL MOVE THROUGH COASTAL WATERS THIS
MORNING WITH BRIEFLY GUSTY SOUTHERLY WINDS. A MUCH STRONGER FRONT
ARRIVES EARLY WEDNESDAY MORNING WITH STRONG SOUTHWEST WINDS TURNING
NORTHWEST BY LATE WEDNESDAY MORNING. IN ADDITION...A LARGE WEST
SWELL WILL PEAK TODAY AND GRADUALLY SUBSIDE TONIGHT AND WEDNESDAY.
SEE THE SMALL CRAFT ADVISORY FOR DETAILS...LAXMWWSGX.
THESE COLD FRONTS WILL ALSO BRING SOME THUNDERSTORMS...MOST LIKELY
WEDNESDAY MORNING. THESE ARE CAPABLE OF PRODUCING WATERSPOUTS AND
STRONG GUSTY WINDS. SEE THE MARINE WEATHER STATEMENT FOR
DETAILS...LAXMWSSGX.
&&
.BEACHES...
200 AM...A LARGE WEST SWELL WILL PEAK TODAY AND BRING HIGH SURF AND
STRONG RIP CURRENTS TO AREA BEACHES. THE SURF WILL SLOWLY SUBSIDE
LATE TODAY THROUGH WEDNESDAY. A HIGH SURF ADVISORY REMAINS IN EFFECT
THROUGH WEDNESDAY MORNING. SEE THE HIGH SURF ADVISORY FOR THE SURF
DETAILS...LAXCFWSGX.
&&
.SKYWARN...
SKYWARN ACTIVATION MAY BE REQUESTED THIS AFTERNOON THROUGH
WEDNESDAY DUE TO POTENTIAL HEAVY RAIN AND ISOLATED THUNDERSTORMS.
WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS TO THE NATIONAL WEATHER SERVICE.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...SMALL CRAFT ADVISORY UNTIL 10 PM PST WEDNESDAY FOR THE BEACHES
IN THE SAN DIEGO COUNTY COASTAL AREAS.
HIGH SURF ADVISORY UNTIL NOON PST WEDNESDAY FOR THE BEACHES IN
THE ORANGE COUNTY COASTAL AREAS...SAN DIEGO COUNTY COASTAL
AREAS.
WINTER WEATHER ADVISORY UNTIL 6 PM PST THIS EVENING ABOVE 6000
FEET FOR THE SAN BERNARDINO COUNTY MOUNTAINS.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY AFTERNOON
ABOVE 5500 FEET FOR THE SAN BERNARDINO COUNTY MOUNTAINS.
FLASH FLOOD WATCH FROM NOON PST TODAY THROUGH WEDNESDAY
AFTERNOON FOR THE RIVERSIDE COUNTY MOUNTAINS...SANTA ANA
MOUNTAINS AND FOOTHILLS.
WINTER WEATHER ADVISORY FROM 6 AM TO 8 PM PST WEDNESDAY FOR THE
RIVERSIDE COUNTY MOUNTAINS...SAN DIEGO COUNTY MOUNTAINS.
PZ...SMALL CRAFT ADVISORY UNTIL 10 PM PST WEDNESDAY FOR THE BEACHES
IN THE COASTAL WATERS FROM SAN MATEO POINT TO THE MEXICAN
BORDER AND OUT 30 NM...WATERS FROM SAN MATEO POINT TO THE
MEXICAN BORDER EXTENDING 30 TO 60 NM OUT INCLUDING SAN
CLEMENTE ISLAND.
&&
$$
PUBLIC...BROTHERTON
AVIATION/MARINE...MM
AREA FORECAST DISCUSSION
NWS TAUNTON MA
631 AM EST TUE DEC 16 2014
.SYNOPSIS...
A WAVE OF LOW PRESSURE WILL RESULT IN A PERIOD OF RAIN SHOWERS
WORKING ACROSS THE REGION FROM WEST TO EAST TONIGHT. THE SHOWERS
SHOULD COME TO AN END SOMETIME WEDNESDAY MORNING...BUT A FEW HIT AND
MISS RAIN/SNOW SHOWERS WILL LINGER LATER WEDNESDAY INTO THURSDAY
MORNING. A STRENGTHENING LOW PRESSURE CENTER IS EXPECTED TO PASS
SOUTHEAST OF NEW ENGLAND LATE IN THE WEEKEND. IT IS UNCERTAIN AT
THIS TIME IF THIS SYSTEM WILL PASS CLOSE ENOUGH TO PRODUCE
PRECIPITATION ACROSS SOUTHERN NEW ENGLAND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
630 AM UPDATE...
OVERALL TREND IN THE FORECAST REMAINS ON TRACK FOR THIS MORNING.
POTENTIAL FOR FREEZING DRIZZLE SEEMS LOW AT THE MOMENT GIVING THE
HIGH CLOUDS DECK. HAVE NOTICED THAT ORE HAS DROPPED DOWN TO 900 FT
SO PERHAPS SOME PATCHY FREEZING DRIZZLE IN THE NW PORTIONS OF
MASS. RAP BUFKIT SOUNDINGS TO SHOW LOW LEVEL MOISTURE INCREASING
OVER THE NEXT HOUR OR TWO SO SOMETHING TO WATCH STILL. OTHERWISE
MADE A FEW MINOR EDITS ON TIMING OF PRECIP AND DRIZZLE PER LATEST
GUIDANCE.
PREVIOUS DISCUSSION...
THE MAIN CONCERN EARLY THIS MORNING WILL BE FOR PATCHY BLACK ICE
WITH LOW TEMP/DEWPOINT SPREADS. DOES NOT LOOK LIKE IT WILL BE
WIDESPREAD AT THIS TIME...GIVEN CLOUD DECK WORKING IN FROM THE WEST
AND LACK OF FOG. WILL CONTINUE TO MONITOR CLOSELY.
AS FOR THIS AFTERNOON...POTENTIAL FOR SPOTTY DRIZZLE INCREASES WITH
DEEPER LOW LEVEL MOISTURE WORKING INTO THE REGION. THIS WILL FIRST
OCCUR CLOSEST TO THE COAST AND SPREAD INLAND. NOT SURE HOW QUICKLY
THIS WILL HAPPEN THOUGH AND MUCH OF THE DAY WILL PROBABLY END UP DRY
IN MOST LOCALES...WITH JUST A LOT OF CLOUDS. OTHER THAN SPOTTY
DRIZZLE...UPPER LEVEL RIDGING AND DRY MID LEVEL AIR SHOULD KEEP THE
STEADY RAINFALL TO OUR WEST THROUGH LATE AFTERNOON. TEMPS WILL
LIKELY BE ABOVE FREEZING BY THE TIME ANY DRIZZLE ARRIVES.
HIGH TEMPS SHOULD RANGE FROM THE UPPER 30S ACROSS THE INTERIOR HIGH
TERRAIN...TO MAINLY WELL INTO THE 40S ELSEWHERE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
TONIGHT...
INITIAL LOW PRESSURE WILL BE LIFTING ACROSS THE GREAT LAKES AS
SECONDARY LOW DEVELOPS NEAR THE MID ATLANTIC COAST AND MOVES
NORTHEAST. THE RESULT WILL BE AN AREA OF RAIN SHOWERS THAT WILL
WORK INTO THE INTERIOR DURING THE EVENING...BUT LIKELY NOT REACH THE
COASTAL PLAIN UNTIL AFTER MIDNIGHT WHEN BETTER FORCING ARRIVES.
UNTIL THAT HAPPENS THOUGH...LOW CLOUDS/PATCHY FOG AND AREAS OF
DRIZZLE WILL BE POSSIBLE. AS FOR PTYPE TONIGHT...THERMAL PROFILES
WILL BE WARM ENOUGH FOR RAIN ACROSS THE ENTIRE REGION. LOW RISK FOR
A BRIEF PERIOD OF SPOTTY FREEZING RAIN ACROSS FAR NORTHWEST MA
BUT NOT TOO EXCITED ABOUT THAT OCCURRING.
THERE IS A EVEN A LOW RISK FOR AN ISOLATED THUNDERSTORM OR TWO
TOWARD DAYBREAK AS SHOWALTER VALUES APPROACH ZERO ACROSS EASTERN NEW
ENGLAND. NOT ENOUGH CONFIDENCE TO INSERT INTO THE FORECAST AT THIS
TIME...BUT SOMETHING LATER SHIFTS WILL HAVE TO KEEP AN EYE ONE.
WEDNESDAY...
SECONDARY LOW PRESSURE WILL LIKELY MOVE ACROSS SOUTHEAST NEW ENGLAND
WED MORNING. RAIN SHOWERS WILL LIKELY LINGER ACROSS OUR EASTERN AND
PARTICULARLY NORTHEAST ZONES INTO PART OF WED MORNING.
OTHERWISE...MAY SEE A FEW SHOWERS WITH THE UPPER LEVEL SHORTWAVE WED
AFTERNOON...BUT THE STEADY PRECIPITATION WILL HAVE ENDED. HIGH
TEMPS WILL BE WELL UP INTO THE 40S...TO PERHAPS EVEN SOME LOWER 50S
ON THE COASTAL PLAIN. A FEW PEEKS OF SUNSHINE WILL ALSO BE POSSIBLE
ACROSS THE COASTAL PLAIN BY AFTERNOON...BUT STILL EXPECT PLENTY OF
CLOUDS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
HIGHLIGHTS...
* SNOW SHOWERS ACROSS THE INTERIOR WED NIGHT INTO THURS
* DRY WEATHER AND AT OR BELOW AVG TEMPS FRIDAY INTO SAT
* POSSIBLE COASTAL SYSTEM SUNDAY INTO MONDAY
OVERVIEW...
OVERALL 12Z GUIDANCE IS IN AGREEMENT SYNOPTICALLY...HOWEVER THERE
ARE MANY ISSUES REGARDING THE SPLIT FLOW ESP FOR THE WEEKEND. IT
DOES LOOK LIKE A PATTERN CHANGE IS GOING TO OCCUR AS UPPER LEVEL
RIDGING BUILDS INTO CALIFORNIA AND HIGH PRESSURE IN CENTRAL CANADA
MOVES TO EASTERN CANADA. THIS SHOULD FAVOR TROUGHING IN THE SW CONUS
MOVING EASTWARD WHICH COULD KEEP OUR PATTERN ACTIVE BEGINNING NEXT
WEEKEND. GUIDANCE TENDS TO HAVE ISSUES WITH THE PATTERN SHIFT AS
WELL AS PHASING SO TIMING ON ANY SYSTEMS MAY SLOW DOWN OR EVEN SPEED
UP. WHILE WE ARE IN TRANSITION...DEPARTING UPPER LEVEL LOW WILL PUSH
TOWARDS THE MARITIMES BY LATE THURSDAY WITH RIDGING TO MOVING IN
FRIDAY INTO SATURDAY. DIGGING SHORTWAVE INTO THE SE CONUS WILL
DEVELOP A LOW PRESSURE SYSTEM IN THE MID-ATLANTIC. THIS SYSTEM MAY
MOVE ACROSS THE BENCHMARK...THE CANAL OR WELL EAST OF THE BENCHMARK.
FOR NOW TRENDED TOWARDS THE ENSEMBLES FOR THIS FORECAST BECAUSE OF
THE AMOUNT OF UNCERTAINTY.
DETAILS...
WEDNESDAY NIGHT INTO THURSDAY...HIGH CONFIDENCE.
UPPER LEVEL LOW WILL SET UP OVER NEW ENGLAND WEDNESDAY NIGHT BEFORE
EXITING OFF INTO THE MARITIMES LATE THURSDAY. A SECONDARY SHORTWAVE
WILL MOVE THROUGH THE FLOW AND OVER THE REGION ALLOWING FOR PRECIP
TO DEVELOP AND CONTINUE INTO THURSDAY MORNING. STRONG CAA WILL MOVE
IN BEHIND THE FIRST SHORTWAVE SO ANTICIPATE PRECIP TO BE MORE IN THE
FORM OF SNOW...ESP AWAY FROM THE COASTLINE. THESE SNOW SHOWERS WILL
BE MORE SCATTERED IN NATURE WED NIGHT THEN BEGIN TO BECOME MORE
ISOLATED BY THURSDAY AS SHORTWAVE MOVES THROUGH AND DRY AIR PUSHES
INTO THE AREA. AM NOT EXPECTING MUCH IN THE WAY OF ACCUMULATIONS BUT
COULD SEE AN QUICK INCH ACROSS THE HIGHER ELEVATIONS INTO THE NW
ZONES.
TEMPERATURES THROUGH THIS PERIOD WILL BE AT OR BELOW AVERAGE AS
STRONG CAA MOVES THROUGH WITHIN THE NORTHWEST FLOW.
FRIDAY INTO SATURDAY...HIGH CONFIDENCE.
AS UPPER LEVEL LOW SPINS INTO THE MARITIMES...HIGH PRESSURE WILL
BUILD INTO SOUTHERN NEW ENGLAND. THIS SILL ALLOW FOR QUIET AND DRY
WEATHER. TEMPERATURES WILL HOVER NEAR AVERAGE DURING THIS TIME
PERIOD.
SUNDAY INTO MONDAY...LOW CONFIDENCE.
MAIN FOCUS OF THE FORECAST WAS ON THIS TRICKY TIME PERIOD. THE
MODELS/ENSEMBLES HAVE OFFERED A VARIETY OF SOLUTIONS OVER THE PAST
FEW DAYS FROM A VERY LOW AMPLITUDE AND FLAT WAVE MOVING THROUGH THE
SOUTHEAST TO A WRAPPED UP SFC LOW HUGGING THE COAST INTO NEW
ENGLAND. THE ECMWF ENSEMBLE MEAN HAS OFFERED THE BEST CONSISTENCY
WHILE THE DETERMINISTIC ECMWF HAS BEEN LESS STABLE IN ITS DETAILS.
THE GFS IS SHOWING A SYSTEM...BUT IT MORE OF A WAVE FOCUSING ON THE
NORTHERN STREAM. THE GEFS SPREAD IS QUITE LARGE...BUT THERE ARE A
FEW MEMBERS AGREEING WITH THE ECMWF ENSEMBLES. BECAUSE OF THE
AMOUNT OF SPREAD...HAVE A VERY LOW CONFIDENCE ON THE FORECAST BUT
TRENDED TOWARDS WPC AN A BLEND OF THE ENSEMBLES.
OVERALL APPEARS THAT PRECIP WILL MOVE INTO THE REGION AND IMPACT
SOUTHERN NEW ENGLAND BETWEEN THE SAT NIGHT INTO MONDAY TIME FRAME.
THERE MAY BE ENOUGH LINGERING COLD AIR FROM DEPARTING HIGH PRESSURE
THAT THERE COULD BE SOME SNOW ACROSS THE INTERIOR. HOWEVER IF THE
STORMS IS WELL EAST OF THE BENCHMARK THEN NO SNOW WILL OCCUR ACROSS
THE INTERIOR AND IT MAY BE ACROSS THE COAST. SO APPEARS THAT THERE
WILL BE P-TYPE ISSUES AND PERHAPS SOME WIND ISSUES IF THE STORM
TRACKS WEST OF THE BENCHMARK. TIDES FOR THE MASS EAST COAST WILL BE
ASTRONOMICALLY HIGH WITH 11.0 SUNDAY MORNING AND 11.4 MONDAY MORNING
AT BOS. IF NE FLOW STRENGTHENS THEN ANTICIPATE A BUILD UP IN SEAS AS
WELL AS SURGE. SO THERE COULD BE COASTAL FLOODING CONCERNS WITH THE
SYSTEM. AS MENTIONED BEFORE...THIS IS A LOW CONFIDENCE FORECAST WITH
MUCH SPREAD ACROSS THE GUIDANCE. HOWEVER THIS STORM WILL NEED TO BE
WATCH OVER THE COMING DAYS.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH WEDNESDAY/...
TODAY...MODERATE CONFIDENCE. MVFR CONDITIONS...MAINLY IN LOW CLOUDS
WILL CONTINUE TO OVER SPREAD THE REGION FROM EAST TO WEST THIS
MORNING. MVFR CONDITIONS WILL PERSIST THROUGH THE AFTERNOON AND
MAY EVEN SEE LOCALIZED IFR CONDITIONS. CHANCES FOR DRIZZLE AND
PATCHY FOG MAY INCREASE IN COVERAGE THIS AFTERNOON AS LOW LEVEL
MOISTURE CONTINUES TO INCREASE.
TONIGHT...MODERATE CONFIDENCE. WIDESPREAD LOW END MVFR TO IFR
CONDITIONS EXPECTED IN LOW CLOUDS AND FOG PATCHES. BAND OF SHOWERS
WILL WORK ACROSS THE REGION FROM WEST TO EAST AS THE NIGHT WEARS ON.
WEDNESDAY...MODERATE CONFIDENCE. MVFR-IFR CONDITIONS FOR THE FIRST
PART OF THE DAY...BUT SHOULD SOME IMPROVEMENT DURING THE AFTERNOON
FROM SOUTH TO NORTH. SHOWERS ALONG THE COASTAL PLAIN EARLY IN THE
MORNING SHOULD DIMINISH TO A FEW HIT AND MISS SHOWERS BY WED
AFTERNOON.
KBOS TERMINAL...MODERATE CONFIDENCE. MAINLY MVFR CONDITIONS TODAY
BUT CAN/T RULE OUT IFR CONDITIONS DEVELOPING...ESPECIALLY DURING THE
AFTERNOON.
KBDL TERMINAL...MODERATE CONFIDENCE. MVFR CONDITIONS SHOULD DEVELOP
BY 12Z AND PERSIST THROUGH THE DAY. CAN/T RULE OUT SOME IFR
CONDITIONS THIS AFTERNOON.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...
WEDNESDAY NIGHT THROUGH THURSDAY...HIGH CONFIDENCE. MVFR CIGS IN
SCATTERED SNOW SHOWERS. NORTHWEST WINDS NEAR 25 KTS.
THURSDAY THROUGH SATURDAY...HIGH CONFIDENCE. VFR CONDITIONS EXPECTED.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH WEDNESDAY/...HIGH CONFIDENCE.
TODAY...WEAK RIDGE OF HIGH WILL KEEP WINDS/SEAS WELL BELOW SMALL
CRAFT ADVISORY THRESHOLDS.
TONIGHT AND WEDNESDAY...LOW PRESSURE WILL MOVE ACROSS THE REGION
VERY LATE TONIGHT INTO WEDNESDAY MORNING. SEAS MAY REACH MARGINAL
SMALL CRAFT ADVISORY THRESHOLDS TOWARD DAYBREAK ACROSS OUR EASTERN
OUTER-WATERS. HOWEVER...MAIN SMALL CRAFT CONDITIONS WILL ARRIVE WED
AND ESPECIALLY WED AFTERNOON BEHIND LOW PRESSURE. WESTERLY WIND
GUSTS OF 20 TO 30 KNOTS ARE EXPECTED TO DEVELOP AND SCA HEADLINES
ARE POSTED FOR MOST OPEN WATERS.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...MODERATE TO HIGH CONFIDENCE.
ANTICIPATE SMALL CRAFT ADVISORY WINDS IN NW FLOW BEHIND THE
DEPARTING SYSTEM WED INTO THU. SEAS WILL LIKELY BE NEAR OR ABOVE 5
FEET ACROSS THE OPEN WATERS WED INTO THU. LOW CONFIDENCE OF GALES
WED NIGHT THANKS TO STRONG CAA OVER THE RELATIVELY WARM WATER. WINDS
DIMINISHING AND SEAS SUBSIDING THU NIGHT AND LIKELY BELOW SMALL
CRAFT ADVISORY LEVELS FRI THROUGH SAT.
ALTHOUGH JUST BEYOND THE OUTLOOK PERIOD...WE CONTINUE TO MONITOR A
POTENTIAL COASTAL STORM FOR LATE SATURDAY NIGHT AND SUNDAY. THERE IS
A LARGE UNCERTAINTY IN THE TRACK AND INTENSITY OF THIS SYSTEM AND
ANY CORRESPONDING IMPACT ON WINDS AND SEAS IN THE COASTAL WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM WEDNESDAY TO 7 AM EST THURSDAY
FOR ANZ231>235-237.
SMALL CRAFT ADVISORY FROM 4 AM WEDNESDAY TO 7 AM EST THURSDAY
FOR ANZ250-254>256.
&&
$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...FRANK/DUNTEN
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
AREA FORECAST DISCUSSION
NWS DES MOINES IA
607 AM CST TUE DEC 16 2014
.UPDATE...
ISSUED AT 607 AM CST TUE DEC 16 2014
THE WIND ADVISORY WILL BE ALLOWED TO EXPIRE AT 12Z. A HANDFULL OF
SITES ARE STILL AT SUSTAINED CRITERIA /26KTS/ BUT A GRADUAL DOWNWARD
TREND IS STILL EXPECTED AS NOTED IN THE SHORT TERM SECTION BELOW.
&&
.SHORT TERM /TODAY/...
ISSUED AT 335 AM CST TUE DEC 16 2014
IMMEDIATE CONCERNS ARE PRECIP TRENDS AND WIND. PARENT SHORT WAVE
CONTINUES TO MOVE ACROSS IL WITH ONLY MINIMAL UPSTREAM INFLUENCE
FROM DAKOTAS/ONTARIO WAVE. LATEST RAP ANALYSIS SHOWS LITTLE IN THE
WAY OF OMEGA OR FORCING ACROSS FORECAST AREA...JUST SOME TOKEN MID
LEVEL LIFT ASSOCIATED WITH DAKOTAS/ONTARIO WAVE BARELY GENERATING
LIGHT SNOW/FLURRIES NW AND LOWER BASED H85/H7 OMEGA ALONG THE
DMX/DVN BORDER. NOT ENTIRELY SURE WHAT IS GENERATING THAT OUTSIDE
OF MINOR SEGMENT OF THETA-E ADVECTION DRIVEN MORE BY WRAP AROUND
MOISTURE THAN TEMPS. REGARDLESS...ANY LINGERING UPWARD VERTICAL
MOTION SHOULD WANE OVER THE NEXT SEVERAL HOURS. ANY PRECIP WILL BE
QUITE LIGHT AND TOKEN...BUT WITH TYPE PROBLEMATIC. IR SATELLITE
CLOUD TOP TEMPS AND SOUNDINGS SUGGEST ICE INTRODUCTION WILL VARY
SO FREEZING AND FROZEN HYDROMETEORS ARE BOTH POSSIBLE...AND EVEN
A BRIEF PERIOD OF LIQUID STILL POSSIBLE FAR EAST WITH WARM LAYER
TEMPS STILL 1-3C THERE. NEARLY ALL MODELS ARE UNDERESTIMATING THE
EXTENT OF STRATUS ACROSS THE GREATER MO VALLEY SO HAVE HELD ONTO
CLOUDS FOR MUCH OF THE DAY. LITTLE CONFIDENCE HOW LONG THEY WILL
HOLD ON...BUT CERTAINLY LONGER THAN MODELS SUGGEST.
NO CHANGES TO CURRENT WIND ADVISORY WITH SEVERAL SITES STILL HITTING
SUSTAINED CRITERIA. THEY SHOULD NOT LAST MUCH LONGER HOWEVER WITH
ISALLOBARIC EFFECTS DIMINISHING WITH PRESSURE RISE MAX INTO SERN
IA...AND MAX MSLP GRADIENT EXITING FORECAST AREA. RAP SOUNDINGS
SUGGEST MIXING WILL SUPPORT GUSTS NOT QUITE TO CRITERIA /39KTS/
BUT STILL WELL INTO THE 30S. TEMPS WILL BE FALLING THROUGH MUCH OF
THE DAY. THERE MAY BE A VERY MINOR REBOUND TOWARD MIDDAY BASED ON
RAW TEMP PLUMES...BUT HIGH TEMPS WILL BE AT BEGINNING OF VALID
PERIOD.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 335 AM CST TUE DEC 16 2014
THE SYNOPTIC PATTERN HAS FINALLY CHANGED AND WE WILL SEE COOLER
AND SOMEWHAT MORE ACTIVE WEATHER ACROSS CENTRAL IOWA FOR THE NEXT
SEVEN DAYS AND BEYOND. AT 500 MB...A COMPACT LOW PRESSURE CENTER
MOVING OVER MINNESOTA LATER TODAY WILL SLIDE QUICKLY EASTWARD OVER
THE GREAT LAKES TONIGHT AND WEDNESDAY. AT THE SURFACE...THIS
DEPARTURE WILL BE REFLECTED BY A RIDGE OF HIGH PRESSURE BUILDING
DOWN THE DAKOTAS AND INTO IOWA LATE TONIGHT THROUGH
WEDNESDAY...REINFORCING THE COLDER AIR BUT ALSO PROHIBITING
PRECIPITATION ACROSS THE STATE.
MEANWHILE...A LARGE AND BROAD 500 MB TROUGH WILL BUILD OVER THE
ROCKIES AND WESTERN U.S. ON WEDNESDAY...AND EVENTUALLY PROGRESS
EASTWARD AS A SOMEWHAT CONFUSED AREA OF GENERAL TROUGHINESS
PERSISTING FOR THE REST OF THE WORK WEEK. THE SURFACE RIDGE
DISCUSSED EARLIER WILL STUBBORNLY CLING TO MINNESOTA AND MUCH OF
IOWA DURING THIS TIME EVEN AS ATMOSPHERIC MOISTURE ABOVE A VERY
SHALLOW NEAR SURFACE LAYER INCREASES DRAMATICALLY AROUND THURSDAY.
FORECAST SOUNDINGS ARE UNANIMOUS IN ILLUSTRATING THIS MOISTURE
INCREASE COINCIDENT WITH THE ARRIVAL OF THE BROAD 500 MB
TROUGH...HOWEVER...ANY FORCING ASSOCIATED WITH THIS UPPER FEATURE
WILL BE MODEST AT BEST AND THE RESULT WILL LIKELY BE THICK LAYERED
CLOUDS AND SOME FLURRIES OR LIGHT SNOW AT TIMES. HAVE INCLUDED LOW
POPS IN THE 20 TO 30 RANGE FOR SOME OF THIS PERIOD...BUT NO
SIGNIFICANT IMPACTS ARE ANTICIPATED.
A MORE INTERESTING ATMOSPHERIC FEATURE APPEARS IN THE FORM OF A
LONGWAVE BUT INITIALLY SUBTLE 500 MB TROUGH MOVING ASHORE OVER THE
PACIFIC U.S. COAST AROUND SATURDAY. AS THIS TROUGH SUBSEQUENTLY
MOVES EASTWARD OVER THE ROCKIES AND EMERGES OVER THE HIGH PLAINS
AND MIDWEST IT SHOULD INTENSIFY TO SOME EXTENT...THEN BE
REINFORCED BY TRAILING SHORTWAVES AND CARVE OUT A LARGE CENTRAL
U.S. TROUGH EARLY NEXT WEEK. THERE IS OF COURSE A HIGHER DEGREE OF
UNCERTAINTY AT SUCH A LONG RANGE...HOWEVER...IT DOES APPEAR THAT
THERE WILL BE A DECENT CHANCE FOR SOME KIND OF PRECIPITATION
ACROSS IOWA SOMETIME BETWEEN AROUND SUNDAY NIGHT AND TUESDAY OF
NEXT WEEK. EVEN SO...IT REMAINS TO BE SEEN WHETHER TEMPERATURES
WOULD BE MORE SUPPORTIVE OF RAIN OR SNOW FROM THIS SYSTEM. FOR NOW
HAVE ADVERTISED CHANCE POPS EARLY NEXT WEEK AND IT WILL TAKE SOME
TIME BEFORE THERE IS ANY DEGREE OF CONFIDENCE TO RAISE OR
ELIMINATE THEM.
&&
.AVIATION...16/12Z
ISSUED AT 607 AM CST TUE DEC 16 2014
PRIMARY CONCERN THROUGH THE PERIOD WILL BE CLOUD TRENDS.
WIDESPREAD MVFR CIGS...WITH ISOLATED IFR...EXTEND FROM IA
UPSTREAM INTO NE...SD AND MN. VIS/FOG SATELLITE IMAGERY DOES NOTE
A SLIVER OR TWO OF CLEARING OVER THE ERN DAKOTAS...BUT OVERALL
TRENDS APPEAR TO FAVOR CONTINUED MVFR CIGS. MODELS HAVE NOT BEEN
HANDLING LOW CLOUD TREND WELL...UNDERREPRESENTED...SO ESSENTIALLY
STAYED WITH PERSISTENCE AT TAF SITES UNTIL TRENDS SUGGEST
OTHERWISE.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...SMALL
SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...SMALL
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1020 AM EST TUE DEC 16 2014
.UPDATE...
ISSUED AT 1020 AM EST TUE DEC 16 2014
14Z SFC ANALYSIS SHOWS A FAIRLY DEEP AREA OF LOW PRESSURE MOVING
THROUGH THE NORTHERN OHIO VALLEY. A COLD FRONT EXTENDS SOUTH OF THIS
AND IS CURRENTLY CROSSING EAST KENTUCKY...JUST REACHING JKL. A LINE
OF LIGHT RAIN ACCOMPANIES THIS BOUNDARY ALONG WITH AREAS OF DRIZZLE
IN ITS WAKE. THE EARLIER THUNDERSTORMS COMING OUT OF SOUTHERN INDIANA
APPEARS TO HAVE SETTLED SO THAT LIGHT RAIN AND DRIZZLE WILL BE THE
MAIN WEATHER TYPE FOR OUR AREA INTO THE AFTERNOON. IN ADDITION TO THE
PCPN CHANCES WITH THE FRONT...GUSTY WINDS FROM THE WEST ACCOMPANY AND
TRAIL THE BOUNDARY. THESE WILL BRING IN COOLER AIR TO EASTERN
KENTUCKY THROUGH THE REST OF THE DAY. THIS MEANS THAT WE HAVE LIKELY
REACHED OUR HIGHS FOR THE DAY IN MOST PLACES...PARTICULARLY IN THE
EAST WHERE PATCHES OF SUNSHINE IN THE WAKE OF THE LOW/S WARM FRONT
HAVE SENT READINGS INTO THE LOW AND MID 50S. 40S WILL FOLLOW WHILE
DEWPOINTS WILL REMAIN RATHER UNIFORM ON EITHER SIDE OF THE FRONT...
GENERALLY IN THE LOW AND MID 40S. HAVE UPDATED THE FORECAST TO
REFLECT THE ABOVE CHANGES AND TO ALSO INFUSE SOME OF THE LATEST HIGH
RESOLUTION GUIDANCE FROM THE HRRR AND 12Z NAM. THESE GRIDS HAVE BEEN
SENT TO THE NDFD AND WEB SERVERS. WILL ALSO UPDATE THE ZONES AND
HWO...MAINLY TO REMOVE THE THUNDER CHANCES THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 351 AM EST TUE DEC 16 2014
A SURFACE LOW PRESSURE CENTER IS CURRENTLY RIDING JUST NORTH OF THE
OHIO RIVER VALLEY...LOCATED SOMEWHERE FAIRLY CLOSE TO INDIANAPOLIS.
AS THIS LOW CONTINUES TO PROGRESS ENEWARD...IT IS CURRENTLY PULLING
A WARM FRONT FROM SW TO NE ACROSS THE CWA /SHOULD BE THROUGH BY
AROUND 12Z/...AND THEN WILL FOLLOW UP WITH A COLD FRONT PASSING
THROUGH THE CWA FROM WEST TO EAST BETWEEN APPROX 10Z AND 15Z. WITH
EACH OF THESE SYSTEMS...WE ARE CONTINUING TO PICK UP LIGHT SHOWER
ACTIVITY...WITH SCATTERED TO WIDESPREAD RETURNS ACROSS PORTIONS OF
EASTERN KY IN RESPONSE TO THE WARM FRONT...AND ANOTHER AREA JUST
ALONG THE COLD FRONT ACROSS WEST CENTRAL KY. UNFORTUNATELY...MODELS
ARE STILL HAVING A HARD TIME SHOWING A WELL DEFINED PRECIP FORECAST
FOR THIS SYSTEM. LEANED ON A MIXTURE OF RADAR TRENDS...THE HRRR AND
RUC /WHICH SEEMED TO HAVE THE BEST HANDLE ON THE CURRENT
SITUATION/...AND SOME LESSER INFLUENCE FROM A BLEND OF OTHER HI RES
MODELS...TO COME UP WITH THE FORECAST FOR THE PROGRESSION OF THE RAIN
AS WE HEAD THROUGH TODAY. AS SUCH...THE CURRENT RAIN /AND ISOLATED
THUNDER/ OVER CENTRAL KY SHOULD MAKE IT INTO OUR WESTERN CWA WITHIN
THE NEXT FEW HOURS /AROUND 10 TO 11Z/...WHILE CHANCES WILL INCREASE
ALONG MUCH OF THE NE CWA AS THE LOW TRACKS JUST TO OUR NORTH.
DID CONTINUE TO NOTE THAT MOST OF THIS MOISTURE SHOWS UP AS BEING
FAIRLY SHALLOW IN THE FORECAST SOUNDINGS THROUGH TODAY...SO DON/T
EXPECT ANYTHING OTHER THAN LIGHT SHOWERS. ONCE DRY AIR MOVES IN
BEHIND THE COLD FRONT THIS AFTERNOON...EXPECT IT TO ONCE AGAIN TRAP
A LAYER OF LOW LEVEL MOISTURE NEAR THE SURFACE...WHERE IT WILL
LINGER THROUGH AROUND 15Z TOMORROW...LONG AFTER THE INFLUENCE OF THE
LOW PRESSURE SYSTEM. AS SUCH...WHILE SOME OF THIS MOISTURE WILL FALL
AS LIGHT RAIN DURING THE DAY TODAY...IT STANDS TO REASON THAT IT
COULD BE MIXED IN WITH DRIZZLE IN SOME LOCATIONS...AND THEN CHANGE
OVER TO ALL DRIZZLE TONIGHT AS MOISTURE BECOMES INCREASINGLY SHALLOW.
TRIED TO REFLECT THIS IN THE WEATHER GRIDS...WITH A MIXTURE OF
ISOLATED/SLIGHT CHANCE RAIN AND PATCHY DRIZZLE...THEN LIGHT DRIZZLE
LINGERING THROUGH TOMORROW MORNING.
TEMPS WILL RISE SOME THROUGHOUT THE MORNING...WITH SOME PLACES IN
THE EAST POSSIBLY PULLING OUT SOME LOW 50S DUE TO THE WAA BEHIND THE
WARM FRONT...BUT SHOULD GENERALLY FALL FROM WEST TO EAST DURING THE
AFTERNOON AS COLDER AIR FILTERS IN BEHIND THE COLD FRONTAL PASSAGE.
WINDS WILL ALSO CONTINUE TO BE GUSTY AHEAD AND JUST BEHIND THE
FRONT...DYING DOWN AS WE HEAD INTO THE EVENING HOURS. THE PUSH OF
COLDER AIR COULD ALLOW FOR SOME BELOW FREEZING TEMPS BY
OVERNIGHT...NAMELY IN THE HIGHEST TERRAIN IN THE SE. AS SUCH...SOME
FREEZING DRIZZLE IN THESE LOCATIONS CANNOT BE RULED OUT. DID GO AHEAD
AND KEEP A MENTION OF THIS IN THE GRIDS...BUT WILL NEED TO KEEP AN
EYE OUT AS WE HEAD INTO TONIGHT IN CASE ANY FURTHER ACTION NEEDS TO BE
TAKEN. HIGHS WEDNESDAY WILL FALL BELOW SEASONABLE NORMS ONCE
MORE...TOPPING OUT IN THE LOW 40S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 419 AM EST TUE DEC 16 2014
THE MODELS ARE IN GOOD AGREEMENT WITH A PROGRESSIVE LONG WAVE PATTERN
TO HOLD ON THROUGH THE END OF THE WEEK...FOLLOWED BY AMPLIFICATION
INTO EARLY NEXT WEEK. DETAILS WITHIN THE LONG WAVE PATTERN CONTINUE
TO BE CHALLENGING...SO HAVE STUCK FAIRLY CLOSE TO A BLEND OF THE
GUIDANCE...WHILE STEERING THE FORECAST TOWARDS GENERAL MODEL TRENDS
SEEN IN THE PAST FEW DAYS.
THE SOUTHERN STREAM WILL MAINLY BE PROVIDING OUR WEATHER THROUGH THE
PERIOD...AS TROUGHING ACROSS THE SOUTHWEST CONUS GRADUALLY
TRANSLATES EAST. INITIALLY...A DAMPENING SHORT WAVE TROUGH WILL EJECT
OUT OF THE MAIN TROUGH...AFFECTING OUR AREA VERY LATE WEDNESDAY NIGHT
INTO THURSDAY. FORCING WILL BE CONFINED TO THE MID AND UPPER
LEVELS...AND DEEPER MOISTURE CONTINUES TO BE LACKING ACROSS EASTERN
KENTUCKY. AS SUCH...WILL MAINTAIN A SLIGHT CHANCE OF SNOW/RAIN
GENERALLY NEAR AND SOUTH OF THE HAL ROGERS AND HIGHWAY 80 CORRIDORS.
THE MAIN TROUGH AXIS WILL THEN MOVE ACROSS THE GULF COAST STATES AND
EVENTUALLY SWING ACROSS THE SOUTHERN APPALACHIANS BY THE WEEKEND.
THE MODELS HAVE GENERALLY SHOWN A MORE SOUTHERLY TRACK WITH THE
ASSOCIATED SURFACE LOW. THE GFS HAS ALSO TRENDED NOTICEABLY SLOWER
WITH THE PRECIPITATION ONSET. THE THERMAL PROFILES CONTINUE TO DIFFER
QUITE A BIT...WITH THE ECMWF COOLER AND THE GFS WARMER. AS
SUCH...HAVE MAINTAINED A BROAD BRUSH WITH THE RAIN/SNOW POTENTIAL
UNTIL CONFIDENCE INCREASES. PRECIPITATION WILL BEGIN FRIDAY
NIGHT...WITH THE OVERALL BEST CHANCE FOR THE ENTIRE AREA ON SATURDAY.
PRECIPITATION WILL THEN TAPER OFF QUICKLY SATURDAY NIGHT...WITH ONLY
A SMALL CHANCE OF A FEW LINGERING SHOWERS IN THE FAR SOUTHEAST
THROUGH SUNDAY MORNING WITH UPSLOPE FLOW IN PLACE. HIGH PRESSURE WILL
THEN TAKE HOLD INTO EARLY NEXT WEEK...BEFORE A DEEPER TROUGH
APPROACHES FROM THE WEST.
BELOW NORMAL TEMPERATURES WILL REIGN THROUGH THE PERIOD. STUCK FAIRLY
CLOSE TO THE BLENDED GUIDANCE GIVEN THE UNCERTAINTY...HOWEVER DID
ALLOW FOR A MORE DIURNALLY LIMITED TEMPERATURE REGIME DURING THE
PERIODS OF GREATER PRECIPITATION CHANCES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 700 AM EST TUE DEC 16 2014
AFTER SHOWERS MOVED THROUGH IN RESPONSE TO A PASSING WARM FRONT...A
COLD FRONT IS NOW ABOUT TO TRAVERSE EASTERN KY DURING THE COURSE OF
THE MORNING. THIS WILL BRING ANOTHER ROUND OF SHOWERS TO PORTIONS OF
EASTERN KY. BASED ON LATEST RADAR TRENDS...IT SEEMS AS THOUGH THE
BEST OF THESE SHOWERS SHOULD STAY NORTH OF THE MOUNTAIN PARKWAY.
FORECAST SOUNDINGS ARE STILL POINTING AT A STRONG SUBSIDENCE
INVERSION SETTING UP BEHIND THE FRONT...WITH LOW LEVEL MOISTURE
BECOMING TRAPPED THROUGH THE TAF PERIOD. THIS WILL LEAD TO LOWERING
CIGS AND THE POTENTIAL FOR DRIZZLE THROUGH TOMORROW MORNING. FUEL
ALTERNATES ARE CONTINUING TO LOOK MORE LIKELY AS WE HEAD INTO THE
OVERNIGHT HOURS. ANOTHER CONCERN WILL BE THE WINDS. EXPECT WINDS AT
THE SURFACE TO INCREASE AGAIN ALONG AND JUST BEHIND THE COLD
FRONT...WITH GUSTS BETWEEN 15 AND 20KTS POSSIBLE THROUGH THE
AFTERNOON. WESTERLY WINDS WILL ALSO SIGNIFICANTLY INCREASE ALOFT AS A
JET STREAK PASSES ALONG AND SOUTH OF THE OHIO RIVER VALLEY DURING
MUCH OF THE TAF PERIOD. THE OVERNIGHT SUBSIDENCE INVERSION SHOULD AT
LEAST ALLOW WINDS IN THE LOW LEVELS TO DIE DOWN.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...JMW
LONG TERM...GEOGERIAN
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
700 AM EST TUE DEC 16 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 351 AM EST TUE DEC 16 2014
A SURFACE LOW PRESSURE CENTER IS CURRENTLY RIDING JUST NORTH OF THE
OHIO RIVER VALLEY...LOCATED SOMEWHERE FAIRLY CLOSE TO INDIANAPOLIS.
AS THIS LOW CONTINUES TO PROGRESS ENEWARD...IT IS CURRENTLY PULLING
A WARM FRONT FROM SW TO NE ACROSS THE CWA /SHOULD BE THROUGH BY
AROUND 12Z/...AND THEN WILL FOLLOW UP WITH A COLD FRONT PASSING
THROUGH THE CWA FROM WEST TO EAST BETWEEN APPROX 10Z AND 15Z. WITH
EACH OF THESE SYSTEMS...WE ARE CONTINUING TO PICK UP LIGHT SHOWER
ACTIVITY...WITH SCATTERED TO WIDESPREAD RETURNS ACROSS PORTIONS OF
EASTERN KY IN RESPONSE TO THE WARM FRONT...AND ANOTHER AREA JUST
ALONG THE COLD FRONT ACROSS WEST CENTRAL KY. UNFORTUNATELY...MODELS
ARE STILL HAVING A HARD TIME SHOWING A WELL DEFINED PRECIP FORECAST
FOR THIS SYSTEM. LEANED ON A MIXTURE OF RADAR TRENDS...THE HRRR AND
RUC /WHICH SEEMED TO HAVE THE BEST HANDLE ON THE CURRENT
SITUATION/...AND SOME LESSER INFLUENCE FROM A BLEND OF OTHER HI RES
MODELS...TO COME UP WITH THE FORECAST FOR THE PROGRESSION OF THE RAIN
AS WE HEAD THROUGH TODAY. AS SUCH...THE CURRENT RAIN /AND ISOLATED
THUNDER/ OVER CENTRAL KY SHOULD MAKE IT INTO OUR WESTERN CWA WITHIN
THE NEXT FEW HOURS /AROUND 10 TO 11Z/...WHILE CHANCES WILL INCREASE
ALONG MUCH OF THE NE CWA AS THE LOW TRACKS JUST TO OUR NORTH.
DID CONTINUE TO NOTE THAT MOST OF THIS MOISTURE SHOWS UP AS BEING
FAIRLY SHALLOW IN THE FORECAST SOUNDINGS THROUGH TODAY...SO DON/T
EXPECT ANYTHING OTHER THAN LIGHT SHOWERS. ONCE DRY AIR MOVES IN
BEHIND THE COLD FRONT THIS AFTERNOON...EXPECT IT TO ONCE AGAIN TRAP
A LAYER OF LOW LEVEL MOISTURE NEAR THE SURFACE...WHERE IT WILL
LINGER THROUGH AROUND 15Z TOMORROW...LONG AFTER THE INFLUENCE OF THE
LOW PRESSURE SYSTEM. AS SUCH...WHILE SOME OF THIS MOISTURE WILL FALL
AS LIGHT RAIN DURING THE DAY TODAY...IT STANDS TO REASON THAT IT
COULD BE MIXED IN WITH DRIZZLE IN SOME LOCATIONS...AND THEN CHANGE
OVER TO ALL DRIZZLE TONIGHT AS MOISTURE BECOMES INCREASINGLY SHALLOW.
TRIED TO REFLECT THIS IN THE WEATHER GRIDS...WITH A MIXTURE OF
ISOLATED/SLIGHT CHANCE RAIN AND PATCHY DRIZZLE...THEN LIGHT DRIZZLE
LINGERING THROUGH TOMORROW MORNING.
TEMPS WILL RISE SOME THROUGHOUT THE MORNING...WITH SOME PLACES IN
THE EAST POSSIBLY PULLING OUT SOME LOW 50S DUE TO THE WAA BEHIND THE
WARM FRONT...BUT SHOULD GENERALLY FALL FROM WEST TO EAST DURING THE
AFTERNOON AS COLDER AIR FILTERS IN BEHIND THE COLD FRONTAL PASSAGE.
WINDS WILL ALSO CONTINUE TO BE GUSTY AHEAD AND JUST BEHIND THE
FRONT...DYING DOWN AS WE HEAD INTO THE EVENING HOURS. THE PUSH OF
COLDER AIR COULD ALLOW FOR SOME BELOW FREEZING TEMPS BY
OVERNIGHT...NAMELY IN THE HIGHEST TERRAIN IN THE SE. AS SUCH...SOME
FREEZING DRIZZLE IN THESE LOCATIONS CANNOT BE RULED OUT. DID GO AHEAD
AND KEEP A MENTION OF THIS IN THE GRIDS...BUT WILL NEED TO KEEP AN
EYE OUT AS WE HEAD INTO TONIGHT IN CASE ANY FURTHER ACTION NEEDS TO BE
TAKEN. HIGHS WEDNESDAY WILL FALL BELOW SEASONABLE NORMS ONCE
MORE...TOPPING OUT IN THE LOW 40S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 419 AM EST TUE DEC 16 2014
THE MODELS ARE IN GOOD AGREEMENT WITH A PROGRESSIVE LONG WAVE PATTERN
TO HOLD ON THROUGH THE END OF THE WEEK...FOLLOWED BY AMPLIFICATION
INTO EARLY NEXT WEEK. DETAILS WITHIN THE LONG WAVE PATTERN CONTINUE
TO BE CHALLENGING...SO HAVE STUCK FAIRLY CLOSE TO A BLEND OF THE
GUIDANCE...WHILE STEERING THE FORECAST TOWARDS GENERAL MODEL TRENDS
SEEN IN THE PAST FEW DAYS.
THE SOUTHERN STREAM WILL MAINLY BE PROVIDING OUR WEATHER THROUGH THE
PERIOD...AS TROUGHING ACROSS THE SOUTHWEST CONUS GRADUALLY
TRANSLATES EAST. INITIALLY...A DAMPENING SHORT WAVE TROUGH WILL EJECT
OUT OF THE MAIN TROUGH...AFFECTING OUR AREA VERY LATE WEDNESDAY NIGHT
INTO THURSDAY. FORCING WILL BE CONFINED TO THE MID AND UPPER
LEVELS...AND DEEPER MOISTURE CONTINUES TO BE LACKING ACROSS EASTERN
KENTUCKY. AS SUCH...WILL MAINTAIN A SLIGHT CHANCE OF SNOW/RAIN
GENERALLY NEAR AND SOUTH OF THE HAL ROGERS AND HIGHWAY 80 CORRIDORS.
THE MAIN TROUGH AXIS WILL THEN MOVE ACROSS THE GULF COAST STATES AND
EVENTUALLY SWING ACROSS THE SOUTHERN APPALACHIANS BY THE WEEKEND.
THE MODELS HAVE GENERALLY SHOWN A MORE SOUTHERLY TRACK WITH THE
ASSOCIATED SURFACE LOW. THE GFS HAS ALSO TRENDED NOTICEABLY SLOWER
WITH THE PRECIPITATION ONSET. THE THERMAL PROFILES CONTINUE TO DIFFER
QUITE A BIT...WITH THE ECMWF COOLER AND THE GFS WARMER. AS
SUCH...HAVE MAINTAINED A BROAD BRUSH WITH THE RAIN/SNOW POTENTIAL
UNTIL CONFIDENCE INCREASES. PRECIPITATION WILL BEGIN FRIDAY
NIGHT...WITH THE OVERALL BEST CHANCE FOR THE ENTIRE AREA ON SATURDAY.
PRECIPITATION WILL THEN TAPER OFF QUICKLY SATURDAY NIGHT...WITH ONLY
A SMALL CHANCE OF A FEW LINGERING SHOWERS IN THE FAR SOUTHEAST
THROUGH SUNDAY MORNING WITH UPSLOPE FLOW IN PLACE. HIGH PRESSURE WILL
THEN TAKE HOLD INTO EARLY NEXT WEEK...BEFORE A DEEPER TROUGH
APPROACHES FROM THE WEST.
BELOW NORMAL TEMPERATURES WILL REIGN THROUGH THE PERIOD. STUCK FAIRLY
CLOSE TO THE BLENDED GUIDANCE GIVEN THE UNCERTAINTY...HOWEVER DID
ALLOW FOR A MORE DIURNALLY LIMITED TEMPERATURE REGIME DURING THE
PERIODS OF GREATER PRECIPITATION CHANCES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 700 AM EST TUE DEC 16 2014
AFTER SHOWERS MOVED THROUGH IN RESPONSE TO A PASSING WARM FRONT...A
COLD FRONT IS NOW ABOUT TO TRAVERSE EASTERN KY DURING THE COURSE OF
THE MORNING. THIS WILL BRING ANOTHER ROUND OF SHOWERS TO PORTIONS OF
EASTERN KY. BASED ON LATEST RADAR TRENDS...IT SEEMS AS THOUGH THE
BEST OF THESE SHOWERS SHOULD STAY NORTH OF THE MOUNTAIN PARKWAY.
FORECAST SOUNDINGS ARE STILL POINTING AT A STRONG SUBSIDENCE
INVERSION SETTING UP BEHIND THE FRONT...WITH LOW LEVEL MOISTURE
BECOMING TRAPPED THROUGH THE TAF PERIOD. THIS WILL LEAD TO LOWERING
CIGS AND THE POTENTIAL FOR DRIZZLE THROUGH TOMORROW MORNING. FUEL
ALTERNATES ARE CONTINUING TO LOOK MORE LIKELY AS WE HEAD INTO THE
OVERNIGHT HOURS. ANOTHER CONCERN WILL BE THE WINDS. EXPECT WINDS AT
THE SURFACE TO INCREASE AGAIN ALONG AND JUST BEHIND THE COLD
FRONT...WITH GUSTS BETWEEN 15 AND 20KTS POSSIBLE THROUGH THE
AFTERNOON. WESTERLY WINDS WILL ALSO SIGNIFICANTLY INCREASE ALOFT AS A
JET STREAK PASSES ALONG AND SOUTH OF THE OHIO RIVER VALLEY DURING
MUCH OF THE TAF PERIOD. THE OVERNIGHT SUBSIDENCE INVERSION SHOULD AT
LEAST ALLOW WINDS IN THE LOW LEVELS TO DIE DOWN.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JMW
LONG TERM...GEOGERIAN
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
841 AM EST TUE DEC 16 2014
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 321 AM EST TUE DEC 16 2014
LOW PRESSURE WILL MOVE ACROSS LOWER MICHIGAN TODAY SPREADING RAIN
SHOWERS AS IT GOES. COLDER AIR WILL WRAP INTO THE SYSTEM LATER THIS
EVENING AND THE RAIN WILL MIX WITH AND THEN CHANGE TO LIGHT SNOW.
THIS WILL BEGIN A PERIOD OF NEAR NORMAL TEMPERATURES...ALTHOUGH MUCH
COLDER THAN WHAT WE`VE SEEN LATELY...THAT WILL LAST THROUGH THE
WEEKEND. LIGHT LAKE EFFECT SNOW SHOWERS ARE POSSIBLE WEDNESDAY INTO
THURSDAY WITH LIGHT ACCUMULATIONS POSSIBLE MAINLY WEST OF US-131.
&&
.UPDATE...
ISSUED AT 839 AM EST TUE DEC 16 2014
FOG HAS BECOME DENSE OVER A GOOD PART OF SOUTHWEST LOWER MICHIGAN.
LOOKING AT THE LATEST RAP MODEL DATA...THE LOWEST VISIBILITIES ARE
WHERE THE WINDS ARE CALM...WHICH IS UNDER THE SURFACE LOW. THIS
AREA OF CALM WINDS SHIFTS TO THE EAST NORTHEAST OVER TIME AND BY
16Z IS OVER OUR NORTHEAST CWA....REED CITY TO CLAIR TO NEAR ALMA.
AFTER THAT IT IS GONE. SO I BELIEVE THE FOG AREA WILL PERSIST A
GOOD PART OF THE MORNING BUT ANY ONE LOCATION SHOULD HAVE ONLY 2
TO 3 HOURS OF LOW VISIBILITIES. GIVEN THE SHORT TIME WINDOW FOR
THIS FOG I AS THINKING NOT TO ISSUE A FOG ADVISORY AT THIS POINT.
WE HAVE ALREADY ISSUED A SPECIAL WEATHER STATEMENT ON THE FOG AND
WE WILL CALL THAT GOOD FOR NOW.
OTHERWISE THE ON GOING FORECAST IS GOOD...SHOWERS WILL CONTINUE
THROUGH THE DAY AND CHANGE TO SNOW SHOWERS OVERNIGHT.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 321 AM EST TUE DEC 16 2014
FORECAST CONCERNS DEAL WITH THE EVOLUTION OF THE LOW CURRENTLY
MOVING THROUGH NORTHWEST ILLINOIS.
REGIONAL RADAR AND IR LOOP SHOWS A WELL DEFINED LOW JUST CROSSING
THE MISSISSIPPI. LIGHT RAIN SHOWERS CONTINUE TO PIVOT NORTHWARD FROM
INDIANA AND WE/LL BE LOOKING AT SHOWERS THROUGHOUT THE DAY AS THE
LOW MOVES ACROSS LOWER MICHIGAN. HEAVY RAIN ISN/T ANTICIPATED.
HOWEVER...THERE HAS BEEN SOME LIGHTNING OVER SOUTHERN INDIANA.
MODELS SHOW SOME ELEVATED INSTABILITY DEVELOPING OVER FAR WESTERN
LAKE ERIE THIS MORNING BUT IT PROBABLY TOO FAR AWAY TO RESULT IN
THUNDER IN OUR CWA.
COLDER AIR WILL WRAP INTO THE SYSTEM TONIGHT AND TURN THE LINGERING
PCPN TO LIGHT SNOW SHOWERS. H8 TEMPS FALL TO -12C WEDNESDAY AND THIS
NORMALLY CREATES SUFFICIENT OVER-LAKE INSTABILITY TO GENERATE SNOW
SHOWERS. THE ISSUE THIS TIME THOUGH IS THE SHALLOW MOISTURE. THE
DGZ IS VERY SMALL AND RESIDES AT THE TOP OF THE SHALLOW MOISTURE
AROUND 4K FT. IT/S PROBABLY ENOUGH TO SEE SOME SNOW SHOWERS...AND
LIGHT ACCUMS WEST OF US-131 BUT NOT MUCH MORE THAN THAT. THE SHSN
WILL GRADUALLY DIMINISH WEDNESDAY NIGHT.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 321 AM EST TUE DEC 16 2014
MORE QUIET WEATHER IS IN STORE IN THE LONG TERM PERIOD AS THE SPLIT
FLOW ALOFT CONTINUES AND SURFACE HIGH PRESSURE DOMINATES. THE POLAR
JET STAYS WELL TO OUR NORTH AND THE SRN STREAM BRANCH REMAINS
SOUTH... SO STILL NO MAJOR WINTER SYSTEMS OR ARCTIC AIR IN OUR
FUTURE.
THE MAIN CONCERN WILL BE CLOUD COVER AS STRATUS/FOG/DRIZZLE COULD BE
AN ISSUE AGAIN UNDER THE SFC HIGH. FOR NOW WILL BE OPTIMISTIC WITH
PARTLY SUNNY WORDING BUT THIS COULD CHANGE IN LATER FORECASTS.
TEMPERATURES ARE FORECAST TO BE NEAR NORMAL WITH HIGHS IN THE LOWER
TO MID 30S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 657 AM EST TUE DEC 16 2014
WIDESPREAD LIFR CONDITIONS THIS MORNING WITH CIGS BELOW 500 FT
AND VSBYS BELOW 2 MILES IN LIGHT RAIN/DRIZZLE AND FOG. SLIGHT
IMPROVEMENT INTO IFR CATEGORY EXPECTED THIS AFTERNOON AS THE SFC
LOW WHICH IS OVERHEAD THIS MORNING WORKS EAST AND WINDS
SHIFT/INCREASE OUT OF THE WEST. FURTHER IMPROVEMENT INTO MVFR
CATEGORY IS LIKELY TONIGHT WITH LIGHT RAIN CHANGING TO LIGHT SNOW.
WEST NORTHWEST WINDS WILL BE GUSTY TONIGHT AT 15-25 KTS.
&&
.MARINE...
ISSUED AT 321 AM EST TUE DEC 16 2014
WINDS WILL INCREASE AS THE LOW MOVES BY THIS AFTERNOON. ISSUED A SCA
TO COVER INCREASED WINDS AND WAVES FROM THIS AFTERNOON THROUGH
THURSDAY MORNING.
&&
.HYDROLOGY...
ISSUED AT 321 AM EST TUE DEC 16 2014
NO HYDRO ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY FROM NOON TODAY TO NOON EST THURSDAY FOR
LMZ844>849.
&&
$$
UPDATE...WDM
SYNOPSIS...93
SHORT TERM...93
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...93
MARINE...93
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
707 AM EST TUE DEC 16 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 536 AM EST TUE DEC 16 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SRN STREAM SHRTWV/LOW OVER
NRN IL AND A NRN STREAM SHRTWV ACROSS NW ONTARIO INTO NW MN. AT THE
SFC...LOW PRES WAS LOCATED OVER NRN IL WITH A TROUGH TO THE NORTH
INTO ERN UPPER MI. 295K-300K ISENTROPIC LIFT AHEAD OF THE NRN IL LOW
HAS BROUGHT AN INCREASE IN PCPN COVERAGE/INTENSITY ACROSS CNTRL
UPPER MI WHILE 850-700 FGEN HAS SUPPORTED THE SNOW INTO WRN UPPER
MI. NRLY LOW LEVEL FLOW WITH THE TIGHTENING PRES GRADIENT BEHIND THE
TROUGH HAS BROUGHT COLDER AIR INTO WRN UPPER MI CHANGING THE RAIN TO
SNOW AT CMX/IWD/LNL. EVEN THROUGH TEMPS HAVE ALSO FALLEN BELOW 32F
AT KMQT...THE CIRCULATION AROUND THE SRN STREAM LOW HAS MAINTAINED
AN ELEVATED WARM LAYER (AROUND 850 MB FROM 1C TO 3C) OVER CENTRAL
UPPER MI. EVEN WITH AIR TEMPS FALLING BELOW FREEZING...THE RECENT
WARM CONDITIONS HAVE LIMITED GLAZE POTENTIAL AS MOST SURFACES HAVE
NOT COOLED OFF AS FAST.
TODAY...AS THE SRN STREAM SHRTWV LIFTS TO THE NW THE NRN STREAM
SHRTWV WILL BECOME THE DOMINANT FEATURE LATE TODAY INTO TONIGHT.
EXPECT THAT THE LINGERING WARM LAYER WILL SUPPORT A BRIEF PERIOD OF
LIGHT FREEZING RAIN OR SLEET THROUGH AROUND 14Z. THE BEST
CHANCE FOR ANY ICING WOULD BE OVER THE HIGHER TERRAIN WHERE TEMPS
HAVE ALREADY FALLEN OFF BELOW FREEZING. OTHERWISE...THE RAIN SNOW
CHANGE OVER IS EXPECTED TO MOVE INTO THE ERN CWA BY AFTERNOON WITH
ALL SNOW AT ERY AFTER 21Z. THE NRN STREAM SHRTWV WITH INCREASING
700-500 MB QVECTOR CONV WILL SUPPORT LIGHT TO MODERATE SNOW ACROSS
UPPER MI TODAY. 1 TO 4 INCH AMOUNTS ARE EXPECTED TODAY WITH HIGHEST
AMOUNTS OVER THE WEST HALF WHERE NRLY WINDS BRING ADDITIONAL LAKE
ENHANCEMENT AND UPSLOPE FLOW AS 850 MB TEMPS FALL INTO THE -6C TO
-10C RANGE.
TONIGHT...AS THE MID LEVEL LOW PIVOTS THROUGH NRN WI...LARGE SCALE
LIFT WILL PREVAIL ACROSS UPPER MI WITH CONTINUED LIGHT SNOWFALL
AMOUNTS. THE HEAVIER SNOWFAL WILL CONTINUE INTO THE NORTH NEAR LAKE
SUPERIOR WITH ADDITIONAL SNOWFALL TOTALS IN THE 3 TO 5 INCH RANGE.
HEADLINES...A WINTER WEATHER ADVISORY WAS ISSUED FOR THE NORTHERN
COUNTIES FOR THE MIXED PRECIPITATION THIS MORNING AND LONG DURATION
LIGHT TO MODERATE SNOW EVENT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 330 AM EST TUE DEC 16 2014
THE UPPER LOW WILL BE OVER THE GREAT LAKES REGION AT 12Z
WEDNESDAY...WHILE THE 1006MB SURFACE LOW IS LOCATED OVER FAR
SOUTHEAST ONTARIO. A MID LEVEL TROUGH WILL BE STRETCHING WEST
ACROSS UPPER MICHIGAN AND WILL BE THE PRIMARY FOCUS FOR THE LIGHT
TO OCCASIONALLY MODERATE SNOW OVER MUCH OF UPPER MICHIGAN. THE
STRONGEST SNOW SHOWERS WILL BE OCCURRING OVER THE WESTERN AND NORTH
CENTRAL U.P. WHERE NORTH-NORTHWEST WINDS AND 850MB TEMPS AROUND
-14C WILL LEAD TO LAKE AND TERRAIN ENHANCEMENT. THESE FAVORABLE
CONDITIONS WILL REMAIN FOR THE MORNING HOURS...BUT THEN THE MID
LEVEL TROUGH WILL DROP SOUTH THROUGH UPPER MICHIGAN WEDNESDAY
AFTERNOON...LEADING TO WINDS SHIFTING TO THE NORTH-NORTHEAST AND
BRINGING WARMER 850MB AIR OVER THE AREA. THUS...SHOULD SEE THE
INTENSITY OF THE LAKE ENHANCEMENT DIMINISHING THROUGH THE AFTERNOON
AND INTO THE EVENING HOURS. IT WILL LIKELY LINGER THE LONGEST OVER
THE NORTH CENTRAL DUE TO THE FAVORABLE WIND DIRECTION. WITH MUCH OF
THE FORCING BELOW THE DGZ...WOULD EXPECT THE SNOW RATIOS FOR MUCH OF
THE AREA TO BE IN THE 12-15 TO 1 RANGE. THE ONE AREA WHERE VALUES
COULD BE A LITTLE HIGHER WOULD BE OVER THE WEST...WHERE THE LOW
LEVEL TEMPERATURES ARE A LITTLE COLDER AND PUTTING MORE OF THE CLOUD
IN THE DGZ. BUT EVEN THEN...A LOT OF THE LAKE ENHANCED FORCING IS AT
OR BELOW THE DGZ...WHICH WOULD SUPPORT RIMING OF ANY DENDRITES AND
IN TURN RATIOS IN THE 15-17 TO ONE RANGE. ALL IN ALL...ADDITIONAL
SNOWFALL AMOUNTS ON WEDNESDAY WILL BE IN THE 1-3 INCH
RANGE...HIGHEST IN THE TERRAIN/LAKE ENHANCED AREA OF NORTH CENTRAL
UPPER MICHIGAN.
WITH THE DRIER/WARMER AIR QUICKLY DIVE INTO THE REGION WEDNESDAY
NIGHT...WILL BRING AN END TO THE SNOW SHOWERS FROM NORTH TO SOUTH
THROUGH THE NIGHT. THIS TRANSITION IS SEVERAL HOURS FASTER THAN
SHOWN 24HRS AGO IN THE MODELS AND HAVE SHOWN THAT FASTER END IN THE
POPS. THAT WARMER/DRIER AIR IS ASSOCIATED WITH AN UPPER RIDGE AND
SURFACE HIGH SHIFTING OVER THE UPPER GREAT LAKES REGION. THESE
FEATURES WILL REMAIN IN PLACE THROUGH AT LEAST FRIDAY. THERE ARE
SOME HINTS OF MOISTURE AROUND 925MB BEING TRAPPED BELOW THE
SUBSIDENCE INVERSION ON THURSDAY. WILL HOLD ONTO MOSTLY CLOUDY SKIES
IN THE MORNING IN THE NORTH-NORTHEAST WIND FAVORED AREAS AND THEN
TRANSITION TO PARTLY CLOUDY IN THE AFTERNOON AS THE SFC-925MB
DELTA-T VALUES BECOME MORE MARGINAL.
MODELS CONTINUE TO DIFFER WITH THE EVOLUTION OF BOTH
UPSTREAM/DOWNSTREAM FEATURES WHICH LEADS TO A LITTLE LOWER
CONFIDENCE IN THE WEEKEND FORECAST. THE FIRST FEATURE THAT THEY
DIFFER ON IS A SHORTWAVE PULLING OUT OF THE SOUTHERN PLAINS AND OFF
THE MID ATLANTIC COAST. THE 12Z GEM/ECMWF DEVELOP A STRONGER LOW
WITH A MUCH MORE AMPLIFIED TROUGH...WHILE THE 00Z GFS IS MUCH WEAKER
WITH THE LOW AND FLATTER WITH THE WAVE. LOOKING AT THE ENSEMBLE
MEANS/MEMBERS...THE 12Z ECMWF MEMBERS ARE REMARKABLY CONSISTENT IN
THE EVOLUTION OF THE LOW OFF THE MID ATLANTIC STATES. BUT WHERE
THINGS DIFFER IS WITH THE HANDLING OF THE NEXT WEAK SHORTWAVE MOVING
THROUGH THE NORTHERN STREAM FLOW SATURDAY INTO SUNDAY. WHILE THE 12Z
GEM/ECMWF OPERATIONAL RUNS HOLD ONTO AN UPPER RIDGE OVER THE UPPER
MISSISSIPPI VALLEY DURING THIS TIME...THE ENSEMBLE MEANS MORE
CLOSELY RESEMBLE THE GFS IN THE IDEA OF A WEAK UPPER TROUGH MOVING
THROUGH THE UPPER MISSISSIPPI VALLEY AND THEN THE UPPER GREAT LAKES
THIS WEEKEND. BASED OFF THE 12Z ENSEMBLE MEANS AND THE 00Z
GEM/ECMWF OPERATIONAL RUNS COMING IN MORE IN LINE WITH THAT
IDEA...WILL FOLLOW THAT FOR THIS FORECAST. BUT EVEN WITH THAT WEAK
UPPER TROUGH MOVING THROUGH...THE SURFACE HIGH WILL BE PERSISTENT
AND SHOULD LEAD TO DRY CONDITIONS. 850MB TEMPS LOOK TO BE AROUND
-6C...WHICH IS EVEN MARGINAL FOR LAKE EFFECT CLOUDS IF THERE WAS
ENOUGH MOISTURE PRESENT...SO WILL GO WITH A DRY FORECAST AND PARTLY
CLOUDY SKIES ON SATURDAY AND MOSTLY CLOUDY ON SUNDAY. HIGHS THURSDAY
WILL START OUT NEAR NORMAL THEN SLOWLY WARM TO SLIGHTLY ABOVE NORMAL
VALUES (UPPER 20S AND LOWER 30S) FOR THE WEEKEND.
HEADING INTO NEXT WEEK...ECMWF/GEM/GFS ENSEMBLE MEANS HAVE BEEN
CONSISTENT FOR THE LAST SEVERAL DAYS TO A WEEK ON AN UPPER TROUGH
DROPPING SOUTHEAST FROM THE GULF OF ALASKA AND INTO THE NORTHERN
CONUS. THIS WILL LEAD TO A COOLER PERIOD AROUND CHRISTMAS AND
LIKELY REMAINING FOR THE END OF DECEMBER. ALTHOUGH IT IS STILL 8-9
DAYS OUT...THE CONSISTENCY IN THE ENSEMBLE MODELS ON THIS IDEA
IS WORTH MENTIONING. THEY CONTINUE TO SHOW A CANADIAN LOW TO DROP
THROUGH ONTARIO OR THE UPPER GREAT LAKES REGION ON THE 24TH OR
25TH. WHILE SNOW AMOUNTS ARE UNFORECASTABLE AT THIS TIME...AT
LEAST LIGHT SNOW IS EXPECTED DURING THAT BUSY HOLIDAY TRAVEL PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 705 AM EST TUE DEC 16 2014
A WARM LAYER ALOFT MAY BRING A PERIOD OF SLEET TO SAW THROUGH AROUND
14Z. OTHERWISE...COLD CYCLONIC NRLY FLOW SUPPORTED BY AN UPPER LEVEL
LOW PRESSURE SYSTEM WILL BRING SNOW TO THE TAF SITES THROUGH THE
FCST PERIOD WITH IFR CONDITIONS EXPECTED. THERE MAY ALSO BE SOME
PERIODS OF LIFR VSBY BUT CONFIDENCE IN TIMING ANY EXTENDED PERIOD OF
VSBY BLO 1SM IS LOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 552 AM EST TUE DEC 16 2014
A TIGHTENING PRES GRADIENT BETWEEN LOW PRES OVER NRN IL LIFTING TO
THE NE AND HIGH PRES OVER MANITOBA INTO THE NRN PLAINS WILL RESULT
IN NORTH WINDS OF 20 TO 30 KNOTS WITH A FEW GALE FORCE GUSTS TO 35
KNOTS TODAY INTO THIS EVENING. AS HIGH PRES BUILDS INTO THE NRN
LAKES FROM WED INTO THU...WINDS WILL DIMINISH TO 20 KNOTS OR LESS.
HIGH PRESSURE WILL THEN DOMINATE INTO THE WEEKEND WITH WINDS
REMAINING BELOW 20 KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 7 PM EST WEDNESDAY FOR MIZ006-085.
WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ WEDNESDAY FOR
MIZ001>005-009-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
553 AM EST TUE DEC 16 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 536 AM EST TUE DEC 16 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SRN STREAM SHRTWV/LOW OVER
NRN IL AND A NRN STREAM SHRTWV ACROSS NW ONTARIO INTO NW MN. AT THE
SFC...LOW PRES WAS LOCATED OVER NRN IL WITH A TROUGH TO THE NORTH
INTO ERN UPPER MI. 295K-300K ISENTROPIC LIFT AHEAD OF THE NRN IL LOW
HAS BROUGHT AN INCREASE IN PCPN COVERAGE/INTENSITY ACROSS CNTRL
UPPER MI WHILE 850-700 FGEN HAS SUPPORTED THE SNOW INTO WRN UPPER
MI. NRLY LOW LEVEL FLOW WITH THE TIGHTENING PRES GRADIENT BEHIND THE
TROUGH HAS BROUGHT COLDER AIR INTO WRN UPPER MI CHANGING THE RAIN TO
SNOW AT CMX/IWD/LNL. EVEN THROUGH TEMPS HAVE ALSO FALLEN BELOW 32F
AT KMQT...THE CIRCULATION AROUND THE SRN STREAM LOW HAS MAINTAINED
AN ELEVATED WARM LAYER (AROUND 850 MB FROM 1C TO 3C) OVER CENTRAL
UPPER MI. EVEN WITH AIR TEMPS FALLING BELOW FREEZING...THE RECENT
WARM CONDITIONS HAVE LIMITED GLAZE POTENTIAL AS MOST SURFACES HAVE
NOT COOLED OFF AS FAST.
TODAY...AS THE SRN STREAM SHRTWV LIFTS TO THE NW THE NRN STREAM
SHRTWV WILL BECOME THE DOMINANT FEATURE LATE TODAY INTO TONIGHT.
EXPECT THAT THE LINGERING WARM LAYER WILL SUPPORT A BRIEF PERIOD OF
LIGHT FREEZING RAIN OR SLEET THROUGH AROUND 14Z. THE BEST
CHANCE FOR ANY ICING WOULD BE OVER THE HIGHER TERRAIN WHERE TEMPS
HAVE ALREADY FALLEN OFF BELOW FREEZING. OTHERWISE...THE RAIN SNOW
CHANGE OVER IS EXPECTED TO MOVE INTO THE ERN CWA BY AFTERNOON WITH
ALL SNOW AT ERY AFTER 21Z. THE NRN STREAM SHRTWV WITH INCREASING
700-500 MB QVECTOR CONV WILL SUPPORT LIGHT TO MODERATE SNOW ACROSS
UPPER MI TODAY. 1 TO 4 INCH AMOUNTS ARE EXPECTED TODAY WITH HIGHEST
AMOUNTS OVER THE WEST HALF WHERE NRLY WINDS BRING ADDITIONAL LAKE
ENHANCEMENT AND UPSLOPE FLOW AS 850 MB TEMPS FALL INTO THE -6C TO
-10C RANGE.
TONIGHT...AS THE MID LEVEL LOW PIVOTS THROUGH NRN WI...LARGE SCALE
LIFT WILL PREVAIL ACROSS UPPER MI WITH CONTINUED LIGHT SNOWFALL
AMOUNTS. THE HEAVIER SNOWFAL WILL CONTINUE INTO THE NORTH NEAR LAKE
SUPERIOR WITH ADDITIONAL SNOWFALL TOTALS IN THE 3 TO 5 INCH RANGE.
HEADLINES...A WINTER WEATHER ADVISORY WAS ISSUED FOR THE NORTHERN
COUNTIES FOR THE MIXED PRECIPITATION THIS MORNING AND LONG DURATION
LIGHT TO MODERATE SNOW EVENT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 330 AM EST TUE DEC 16 2014
THE UPPER LOW WILL BE OVER THE GREAT LAKES REGION AT 12Z
WEDNESDAY...WHILE THE 1006MB SURFACE LOW IS LOCATED OVER FAR
SOUTHEAST ONTARIO. A MID LEVEL TROUGH WILL BE STRETCHING WEST
ACROSS UPPER MICHIGAN AND WILL BE THE PRIMARY FOCUS FOR THE LIGHT
TO OCCASIONALLY MODERATE SNOW OVER MUCH OF UPPER MICHIGAN. THE
STRONGEST SNOW SHOWERS WILL BE OCCURRING OVER THE WESTERN AND NORTH
CENTRAL U.P. WHERE NORTH-NORTHWEST WINDS AND 850MB TEMPS AROUND
-14C WILL LEAD TO LAKE AND TERRAIN ENHANCEMENT. THESE FAVORABLE
CONDITIONS WILL REMAIN FOR THE MORNING HOURS...BUT THEN THE MID
LEVEL TROUGH WILL DROP SOUTH THROUGH UPPER MICHIGAN WEDNESDAY
AFTERNOON...LEADING TO WINDS SHIFTING TO THE NORTH-NORTHEAST AND
BRINGING WARMER 850MB AIR OVER THE AREA. THUS...SHOULD SEE THE
INTENSITY OF THE LAKE ENHANCEMENT DIMINISHING THROUGH THE AFTERNOON
AND INTO THE EVENING HOURS. IT WILL LIKELY LINGER THE LONGEST OVER
THE NORTH CENTRAL DUE TO THE FAVORABLE WIND DIRECTION. WITH MUCH OF
THE FORCING BELOW THE DGZ...WOULD EXPECT THE SNOW RATIOS FOR MUCH OF
THE AREA TO BE IN THE 12-15 TO 1 RANGE. THE ONE AREA WHERE VALUES
COULD BE A LITTLE HIGHER WOULD BE OVER THE WEST...WHERE THE LOW
LEVEL TEMPERATURES ARE A LITTLE COLDER AND PUTTING MORE OF THE CLOUD
IN THE DGZ. BUT EVEN THEN...A LOT OF THE LAKE ENHANCED FORCING IS AT
OR BELOW THE DGZ...WHICH WOULD SUPPORT RIMING OF ANY DENDRITES AND
IN TURN RATIOS IN THE 15-17 TO ONE RANGE. ALL IN ALL...ADDITIONAL
SNOWFALL AMOUNTS ON WEDNESDAY WILL BE IN THE 1-3 INCH
RANGE...HIGHEST IN THE TERRAIN/LAKE ENHANCED AREA OF NORTH CENTRAL
UPPER MICHIGAN.
WITH THE DRIER/WARMER AIR QUICKLY DIVE INTO THE REGION WEDNESDAY
NIGHT...WILL BRING AN END TO THE SNOW SHOWERS FROM NORTH TO SOUTH
THROUGH THE NIGHT. THIS TRANSITION IS SEVERAL HOURS FASTER THAN
SHOWN 24HRS AGO IN THE MODELS AND HAVE SHOWN THAT FASTER END IN THE
POPS. THAT WARMER/DRIER AIR IS ASSOCIATED WITH AN UPPER RIDGE AND
SURFACE HIGH SHIFTING OVER THE UPPER GREAT LAKES REGION. THESE
FEATURES WILL REMAIN IN PLACE THROUGH AT LEAST FRIDAY. THERE ARE
SOME HINTS OF MOISTURE AROUND 925MB BEING TRAPPED BELOW THE
SUBSIDENCE INVERSION ON THURSDAY. WILL HOLD ONTO MOSTLY CLOUDY SKIES
IN THE MORNING IN THE NORTH-NORTHEAST WIND FAVORED AREAS AND THEN
TRANSITION TO PARTLY CLOUDY IN THE AFTERNOON AS THE SFC-925MB
DELTA-T VALUES BECOME MORE MARGINAL.
MODELS CONTINUE TO DIFFER WITH THE EVOLUTION OF BOTH
UPSTREAM/DOWNSTREAM FEATURES WHICH LEADS TO A LITTLE LOWER
CONFIDENCE IN THE WEEKEND FORECAST. THE FIRST FEATURE THAT THEY
DIFFER ON IS A SHORTWAVE PULLING OUT OF THE SOUTHERN PLAINS AND OFF
THE MID ATLANTIC COAST. THE 12Z GEM/ECMWF DEVELOP A STRONGER LOW
WITH A MUCH MORE AMPLIFIED TROUGH...WHILE THE 00Z GFS IS MUCH WEAKER
WITH THE LOW AND FLATTER WITH THE WAVE. LOOKING AT THE ENSEMBLE
MEANS/MEMBERS...THE 12Z ECMWF MEMBERS ARE REMARKABLY CONSISTENT IN
THE EVOLUTION OF THE LOW OFF THE MID ATLANTIC STATES. BUT WHERE
THINGS DIFFER IS WITH THE HANDLING OF THE NEXT WEAK SHORTWAVE MOVING
THROUGH THE NORTHERN STREAM FLOW SATURDAY INTO SUNDAY. WHILE THE 12Z
GEM/ECMWF OPERATIONAL RUNS HOLD ONTO AN UPPER RIDGE OVER THE UPPER
MISSISSIPPI VALLEY DURING THIS TIME...THE ENSEMBLE MEANS MORE
CLOSELY RESEMBLE THE GFS IN THE IDEA OF A WEAK UPPER TROUGH MOVING
THROUGH THE UPPER MISSISSIPPI VALLEY AND THEN THE UPPER GREAT LAKES
THIS WEEKEND. BASED OFF THE 12Z ENSEMBLE MEANS AND THE 00Z
GEM/ECMWF OPERATIONAL RUNS COMING IN MORE IN LINE WITH THAT
IDEA...WILL FOLLOW THAT FOR THIS FORECAST. BUT EVEN WITH THAT WEAK
UPPER TROUGH MOVING THROUGH...THE SURFACE HIGH WILL BE PERSISTENT
AND SHOULD LEAD TO DRY CONDITIONS. 850MB TEMPS LOOK TO BE AROUND
-6C...WHICH IS EVEN MARGINAL FOR LAKE EFFECT CLOUDS IF THERE WAS
ENOUGH MOISTURE PRESENT...SO WILL GO WITH A DRY FORECAST AND PARTLY
CLOUDY SKIES ON SATURDAY AND MOSTLY CLOUDY ON SUNDAY. HIGHS THURSDAY
WILL START OUT NEAR NORMAL THEN SLOWLY WARM TO SLIGHTLY ABOVE NORMAL
VALUES (UPPER 20S AND LOWER 30S) FOR THE WEEKEND.
HEADING INTO NEXT WEEK...ECMWF/GEM/GFS ENSEMBLE MEANS HAVE BEEN
CONSISTENT FOR THE LAST SEVERAL DAYS TO A WEEK ON AN UPPER TROUGH
DROPPING SOUTHEAST FROM THE GULF OF ALASKA AND INTO THE NORTHERN
CONUS. THIS WILL LEAD TO A COOLER PERIOD AROUND CHRISTMAS AND
LIKELY REMAINING FOR THE END OF DECEMBER. ALTHOUGH IT IS STILL 8-9
DAYS OUT...THE CONSISTENCY IN THE ENSEMBLE MODELS ON THIS IDEA
IS WORTH MENTIONING. THEY CONTINUE TO SHOW A CANADIAN LOW TO DROP
THROUGH ONTARIO OR THE UPPER GREAT LAKES REGION ON THE 24TH OR
25TH. WHILE SNOW AMOUNTS ARE UNFORECASTABLE AT THIS TIME...AT
LEAST LIGHT SNOW IS EXPECTED DURING THAT BUSY HOLIDAY TRAVEL PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1237 AM EST TUE DEC 16 2014
ALTHOUGH IFR CONDITIONS WL PREDOMINATE AT THE SITES EARLY THIS MRNG
AS AREA OF LARGER SCALE PCPN MOVES OVHD AND COLDER AIR MOVES INTO
THE UPR LKS BEHIND SLOW MOVING COLD FNT... WEAK UPSLOPE FLOW AT CMX
MAY ALLOW FOR SOME MVFR CONDITIONS THERE EARLY IN THE PERIOD. LATER
ARRIVAL OF THE FNT AND MORE SHALLOW NATURE OF THE COLD AIR INFLOW WL
LEAD TO THE POTENTIAL FOR SOME VLIFR CONDITIONS AT SAW UNTIL
SUNRISE. THEN CYC...GUSTY N FLOW THRU TODAY WL LEAD TO WIDESPREAD
-SN/PREDOMINANT IFR CONDITIONS. SOME HEAVIER SN MAY IMPACT THE SITES
TNGT AS ANOTHER DISTURBANCE SLIDES SE THRU THE UPR LKS...LEADING TO
A PERSISTENCE OF IFR TO LIFR CONDITIONS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 552 AM EST TUE DEC 16 2014
A TIGHTENING PRES GRADIENT BETWEEN LOW PRES OVER NRN IL LIFTING TO
THE NE AND HIGH PRES OVER MANITOBA INTO THE NRN PLAINS WILL RESULT
IN NORTH WINDS OF 20 TO 30 KNOTS WITH A FEW GALE FORCE GUSTS TO 35
KNOTS TODAY INTO THIS EVENING. AS HIGH PRES BUILDS INTO THE NRN
LAKES FROM WED INTO THU...WINDS WILL DIMINISH TO 20 KNOTS OR LESS.
HIGH PRESSURE WILL THEN DOMINATE INTO THE WEEKEND WITH WINDS
REMAINING BELOW 20 KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO 7 PM EST
WEDNESDAY FOR MIZ006-085.
WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ WEDNESDAY FOR
MIZ001>005-009-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 7 AM EST THIS MORNING FOR LMZ221-248-
250.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
538 AM EST TUE DEC 16 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 536 AM EST TUE DEC 16 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SRN STREAM SHRTWV/LOW OVER
NRN IL AND A NRN STREAM SHRTWV ACROSS NW ONTARIO INTO NW MN. AT THE
SFC...LOW PRES WAS LOCATED OVER NRN IL WITH A TROUGH TO THE NORTH
INTO ERN UPPER MI. 295K-300K ISENTROPIC LIFT AHEAD OF THE NRN IL LOW
HAS BROUGHT AN INCREASE IN PCPN COVERAGE/INTENSITY ACROSS CNTRL
UPPER MI WHILE 850-700 FGEN HAS SUPPORTED THE SNOW INTO WRN UPPER
MI. NRLY LOW LEVEL FLOW WITH THE TIGHTENING PRES GRADIENT BEHIND THE
TROUGH HAS BROUGHT COLDER AIR INTO WRN UPPER MI CHANGING THE RAIN TO
SNOW AT CMX/IWD/LNL. EVEN THROUGH TEMPS HAVE ALSO FALLEN BELOW 32F
AT KMQT...THE CIRCULATION AROUND THE SRN STREAM LOW HAS MAINTAINED
AN ELEVATED WARM LAYER (AROUND 850 MB FROM 1C TO 3C) OVER CENTRAL
UPPER MI. EVEN WITH AIR TEMPS FALLING BELOW FREEZING...THE RECENT
WARM CONDITIONS HAVE LIMITED GLAZE POTENTIAL AS MOST SURFACES HAVE
NOT COOLED OFF AS FAST.
TODAY...AS THE SRN STREAM SHRTWV LIFTS TO THE NW THE NRN STREAM
SHRTWV WILL BECOME THE DOMINANT FEATURE LATE TODAY INTO TONIGHT.
EXPECT THAT THE LINGERING WARM LAYER WILL SUPPORT A BRIEF PERIOD OF
LIGHT FREEZING RAIN OR SLEET THROUGH AROUND 14Z. THE BEST
CHANCE FOR ANY ICING WOULD BE OVER THE HIGHER TERRAIN WHERE TEMPS
HAVE ALREADY FALLEN OFF BELOW FREEZING. OTHERWISE...THE RAIN SNOW
CHANGE OVER IS EXPECTED TO MOVE INTO THE ERN CWA BY AFTERNOON WITH
ALL SNOW AT ERY AFTER 21Z. THE NRN STREAM SHRTWV WITH INCREASING
700-500 MB QVECTOR CONV WILL SUPPORT LIGHT TO MODERATE SNOW ACROSS
UPPER MI TODAY. 1 TO 4 INCH AMOUNTS ARE EXPECTED TODAY WITH HIGHEST
AMOUNTS OVER THE WEST HALF WHERE NRLY WINDS BRING ADDITIONAL LAKE
ENHANCEMENT AND UPSLOPE FLOW AS 850 MB TEMPS FALL INTO THE -6C TO
-10C RANGE.
TONIGHT...AS THE MID LEVEL LOW PIVOTS THROUGH NRN WI...LARGE SCALE
LIFT WILL PREVAIL ACROSS UPPER MI WITH CONTINUED LIGHT SNOWFALL
AMOUNTS. THE HEAVIER SNOWFAL WILL CONTINUE INTO THE NORTH NEAR LAKE
SUPERIOR WITH ADDITIONAL SNOWFALL TOTALS IN THE 3 TO 5 INCH RANGE.
HEADLINES...A WINTER WEATHER ADVISORY WAS ISSUED FOR THE NORTHERN
COUNTIES FOR THE MIXED PRECIPITATION THIS MORNING AND LONG DURATION
LIGHT TO MODERATE SNOW EVENT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 330 AM EST TUE DEC 16 2014
THE UPPER LOW WILL BE OVER THE GREAT LAKES REGION AT 12Z
WEDNESDAY...WHILE THE 1006MB SURFACE LOW IS LOCATED OVER FAR
SOUTHEAST ONTARIO. A MID LEVEL TROUGH WILL BE STRETCHING WEST
ACROSS UPPER MICHIGAN AND WILL BE THE PRIMARY FOCUS FOR THE LIGHT
TO OCCASIONALLY MODERATE SNOW OVER MUCH OF UPPER MICHIGAN. THE
STRONGEST SNOW SHOWERS WILL BE OCCURRING OVER THE WESTERN AND NORTH
CENTRAL U.P. WHERE NORTH-NORTHWEST WINDS AND 850MB TEMPS AROUND
-14C WILL LEAD TO LAKE AND TERRAIN ENHANCEMENT. THESE FAVORABLE
CONDITIONS WILL REMAIN FOR THE MORNING HOURS...BUT THEN THE MID
LEVEL TROUGH WILL DROP SOUTH THROUGH UPPER MICHIGAN WEDNESDAY
AFTERNOON...LEADING TO WINDS SHIFTING TO THE NORTH-NORTHEAST AND
BRINGING WARMER 850MB AIR OVER THE AREA. THUS...SHOULD SEE THE
INTENSITY OF THE LAKE ENHANCEMENT DIMINISHING THROUGH THE AFTERNOON
AND INTO THE EVENING HOURS. IT WILL LIKELY LINGER THE LONGEST OVER
THE NORTH CENTRAL DUE TO THE FAVORABLE WIND DIRECTION. WITH MUCH OF
THE FORCING BELOW THE DGZ...WOULD EXPECT THE SNOW RATIOS FOR MUCH OF
THE AREA TO BE IN THE 12-15 TO 1 RANGE. THE ONE AREA WHERE VALUES
COULD BE A LITTLE HIGHER WOULD BE OVER THE WEST...WHERE THE LOW
LEVEL TEMPERATURES ARE A LITTLE COLDER AND PUTTING MORE OF THE CLOUD
IN THE DGZ. BUT EVEN THEN...A LOT OF THE LAKE ENHANCED FORCING IS AT
OR BELOW THE DGZ...WHICH WOULD SUPPORT RIMING OF ANY DENDRITES AND
IN TURN RATIOS IN THE 15-17 TO ONE RANGE. ALL IN ALL...ADDITIONAL
SNOWFALL AMOUNTS ON WEDNESDAY WILL BE IN THE 1-3 INCH
RANGE...HIGHEST IN THE TERRAIN/LAKE ENHANCED AREA OF NORTH CENTRAL
UPPER MICHIGAN.
WITH THE DRIER/WARMER AIR QUICKLY DIVE INTO THE REGION WEDNESDAY
NIGHT...WILL BRING AN END TO THE SNOW SHOWERS FROM NORTH TO SOUTH
THROUGH THE NIGHT. THIS TRANSITION IS SEVERAL HOURS FASTER THAN
SHOWN 24HRS AGO IN THE MODELS AND HAVE SHOWN THAT FASTER END IN THE
POPS. THAT WARMER/DRIER AIR IS ASSOCIATED WITH AN UPPER RIDGE AND
SURFACE HIGH SHIFTING OVER THE UPPER GREAT LAKES REGION. THESE
FEATURES WILL REMAIN IN PLACE THROUGH AT LEAST FRIDAY. THERE ARE
SOME HINTS OF MOISTURE AROUND 925MB BEING TRAPPED BELOW THE
SUBSIDENCE INVERSION ON THURSDAY. WILL HOLD ONTO MOSTLY CLOUDY SKIES
IN THE MORNING IN THE NORTH-NORTHEAST WIND FAVORED AREAS AND THEN
TRANSITION TO PARTLY CLOUDY IN THE AFTERNOON AS THE SFC-925MB
DELTA-T VALUES BECOME MORE MARGINAL.
MODELS CONTINUE TO DIFFER WITH THE EVOLUTION OF BOTH
UPSTREAM/DOWNSTREAM FEATURES WHICH LEADS TO A LITTLE LOWER
CONFIDENCE IN THE WEEKEND FORECAST. THE FIRST FEATURE THAT THEY
DIFFER ON IS A SHORTWAVE PULLING OUT OF THE SOUTHERN PLAINS AND OFF
THE MID ATLANTIC COAST. THE 12Z GEM/ECMWF DEVELOP A STRONGER LOW
WITH A MUCH MORE AMPLIFIED TROUGH...WHILE THE 00Z GFS IS MUCH WEAKER
WITH THE LOW AND FLATTER WITH THE WAVE. LOOKING AT THE ENSEMBLE
MEANS/MEMBERS...THE 12Z ECMWF MEMBERS ARE REMARKABLY CONSISTENT IN
THE EVOLUTION OF THE LOW OFF THE MID ATLANTIC STATES. BUT WHERE
THINGS DIFFER IS WITH THE HANDLING OF THE NEXT WEAK SHORTWAVE MOVING
THROUGH THE NORTHERN STREAM FLOW SATURDAY INTO SUNDAY. WHILE THE 12Z
GEM/ECMWF OPERATIONAL RUNS HOLD ONTO AN UPPER RIDGE OVER THE UPPER
MISSISSIPPI VALLEY DURING THIS TIME...THE ENSEMBLE MEANS MORE
CLOSELY RESEMBLE THE GFS IN THE IDEA OF A WEAK UPPER TROUGH MOVING
THROUGH THE UPPER MISSISSIPPI VALLEY AND THEN THE UPPER GREAT LAKES
THIS WEEKEND. BASED OFF THE 12Z ENSEMBLE MEANS AND THE 00Z
GEM/ECMWF OPERATIONAL RUNS COMING IN MORE IN LINE WITH THAT
IDEA...WILL FOLLOW THAT FOR THIS FORECAST. BUT EVEN WITH THAT WEAK
UPPER TROUGH MOVING THROUGH...THE SURFACE HIGH WILL BE PERSISTENT
AND SHOULD LEAD TO DRY CONDITIONS. 850MB TEMPS LOOK TO BE AROUND
-6C...WHICH IS EVEN MARGINAL FOR LAKE EFFECT CLOUDS IF THERE WAS
ENOUGH MOISTURE PRESENT...SO WILL GO WITH A DRY FORECAST AND PARTLY
CLOUDY SKIES ON SATURDAY AND MOSTLY CLOUDY ON SUNDAY. HIGHS THURSDAY
WILL START OUT NEAR NORMAL THEN SLOWLY WARM TO SLIGHTLY ABOVE NORMAL
VALUES (UPPER 20S AND LOWER 30S) FOR THE WEEKEND.
HEADING INTO NEXT WEEK...ECMWF/GEM/GFS ENSEMBLE MEANS HAVE BEEN
CONSISTENT FOR THE LAST SEVERAL DAYS TO A WEEK ON AN UPPER TROUGH
DROPPING SOUTHEAST FROM THE GULF OF ALASKA AND INTO THE NORTHERN
CONUS. THIS WILL LEAD TO A COOLER PERIOD AROUND CHRISTMAS AND
LIKELY REMAINING FOR THE END OF DECEMBER. ALTHOUGH IT IS STILL 8-9
DAYS OUT...THE CONSISTENCY IN THE ENSEMBLE MODELS ON THIS IDEA
IS WORTH MENTIONING. THEY CONTINUE TO SHOW A CANADIAN LOW TO DROP
THROUGH ONTARIO OR THE UPPER GREAT LAKES REGION ON THE 24TH OR
25TH. WHILE SNOW AMOUNTS ARE UNFORECASTABLE AT THIS TIME...AT
LEAST LIGHT SNOW IS EXPECTED DURING THAT BUSY HOLIDAY TRAVEL PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1237 AM EST TUE DEC 16 2014
ALTHOUGH IFR CONDITIONS WL PREDOMINATE AT THE SITES EARLY THIS MRNG
AS AREA OF LARGER SCALE PCPN MOVES OVHD AND COLDER AIR MOVES INTO
THE UPR LKS BEHIND SLOW MOVING COLD FNT... WEAK UPSLOPE FLOW AT CMX
MAY ALLOW FOR SOME MVFR CONDITIONS THERE EARLY IN THE PERIOD. LATER
ARRIVAL OF THE FNT AND MORE SHALLOW NATURE OF THE COLD AIR INFLOW WL
LEAD TO THE POTENTIAL FOR SOME VLIFR CONDITIONS AT SAW UNTIL
SUNRISE. THEN CYC...GUSTY N FLOW THRU TODAY WL LEAD TO WIDESPREAD
-SN/PREDOMINANT IFR CONDITIONS. SOME HEAVIER SN MAY IMPACT THE SITES
TNGT AS ANOTHER DISTURBANCE SLIDES SE THRU THE UPR LKS...LEADING TO
A PERSISTENCE OF IFR TO LIFR CONDITIONS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 311 PM EST MON DEC 15 2014
COLDER AIR WILL MOVE INTO THE AREA THIS EVENING REDUCING THE FOG.
EXPECT N-NW WINDS OF 20-30KTS LATE THIS EVENING INTO EARLY TUESDAY
EVENING. A FEW GALE FORCE GUSTS TO 35KTS WILL BE POSSIBLE AND THIS
WILL BE THE STRONGEST WIND FORECAST FOR THE ENTIRE FORECAST. NO
GALES SEEN ANYTIME SOON OTHERWISE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO 7 PM EST
WEDNESDAY FOR MIZ006-085.
WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ WEDNESDAY FOR
MIZ001>005-009-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 7 AM EST THIS MORNING FOR LMZ221-248-
250.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...KC
MARINE...07
AREA FORECAST DISCUSSION
NWS HASTINGS NE
555 AM CST TUE DEC 16 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CST TUE DEC 16 2014
WITH LITTLE TO NO RISK OF PRECIPITATION DURING THESE NEXT 24
HOURS...THE MAIN FORECAST CHALLENGE CENTERS AROUND
TEMPERATURES/SKY COVER...AND THE OBVIOUS AFFECT ONE HAS ON THE
OTHER...ALONG WITH ANY INFLUENCE ON TEMPS FROM SNOW COVER IN
NORTHERN/WESTERN COUNTIES.
STARTING OFF WITH THE HERE AND NOW AS OF 0900Z/3AM...ITS
CERTAINLY BEEN A MUCH QUIETER NIGHT THAN THE PRECEDING ONE...AS
ANY MEASURABLE PRECIP ASSOCIATED WITH THE DEPARTING LOW PRESSURE
SYSTEM IS NOW WELL-EAST INTO EASTERN IA. IN THE MID AND UPPER
LEVELS...WATER VAPOR SATELLITE AND SHORT TERM MODEL DATA CLEARLY
DEPICT THE CENTER OF THE CLOSED 500 MILLIBAR LOW OVER NORTHERN
IL...WHILE UPSTREAM FROM IT...THE LEADING EDGE OF A BROAD
SHORTWAVE RIDGE AND ASSOCIATED HEIGHT RISES IS STARTING TO
OVERSPREAD THE LOCAL AREA...WITH THE RIDGE AXIS GENERALLY ALIGNED
NORTH-SOUTH THROUGH THE ROCKIES. FARTHER WEST...THE NEXT BROAD
TROUGH IS IN THE PROCESS OF COMING ONSHORE THE WEST COAST...WHICH
WILL PROVIDE PLENTY OF CHALLENGES LOCALLY IN THE DAYS 2-4 PERIOD
AS COVERED IN THE LONG TERM SECTION BELOW. AT THE
SURFACE...CERTAINLY THE BIG STORY OVERNIGHT HAS BEEN CONTINUED
FAIRLY STRONG NORTHWEST WINDS...ALTHOUGH THEY ARE ON A SLOW-BUT-
STEADY DOWNWARD TREND AS THE PRESSURE GRADIENT STARTS TO RELAX IN
THE WAKE OF THE DEPARTING 1004MB LOW OVER NORTHERN IL...AND AS A
BROAD RIDGE AXIS CENTERED AT AROUND 1030MB OVER THE DAKOTAS/SOUTH
CENTRAL CANADA STARTS TO EXERT INCREASING INFLUENCE LOCALLY. AS OF
THIS TIME HOWEVER...SUSTAINED SPEEDS OF AT LEAST 20-25 MPH ARE
HANGING ON IN EASTERN ZONES WITH HIGHER GUSTS...AND MORE SO 15-20
MPH IN WESTERN ZONES. EARLIER IN THE NIGHT...THERE WERE LAW
ENFORCEMENT REPORTS OF SOME DICEY TRAVEL CONDITIONS DUE TO SLICK
ROADS/LIMITED BLOWING SNOW IN/NEAR THE FAR NORTHERN CWA COUNTIES
OF VALLEY/GREELEY...BUT FORTUNATELY THE DECREASING SPEEDS SHOULD
AT LEAST IMPROVE THIS SITUATION SLIGHTLY. ACTUALLY THE NUMBER ONE
VERY SHORT-TERM CHALLENGE IS SKY COVER...AS WHILE THE MAJORITY OF
THE CWA REMAINS UNDER A BROAD LOW STRATUS DECK AROUND 1500 FT
AGL...AN AREA OF CLEARING HAS RECENTLY BROKEN OUT OVER SOUTHWEST
COUNTIES. TEMP-WISE...AS SUSPECTED 24 HOURS THE COMBO OF CLOUDS
AND/OR BRISK BREEZES IS HOLDING UP THINGS FAIRLY WELL...AND
ALTHOUGH SOME DROPS COULD YET OCCUR AROUND SUNRISE...THINK THE
MAJORITY OF THE CWA SHOULD HOLD UP NO COLDER THAN THE 17-20 RANGE.
LOOKING FORWARD INTO THE DAYTIME FORECAST AND STARTING WITH THE
MID-UPPER LEVEL SCENE...THE AFOREMENTIONED BROAD RIDGE AXIS
OVERSPREADS THE CENTRAL PLAINS BUT FLATTENS A BIT AS IT DOES SO.
AT THE SURFACE...CERTAINLY THE MOST NOTICEABLE CHANGE FROM MONDAY
WILL BE THE DECREASING NORTHWESTERLY WINDS...AS THE PRESSURE
GRADIENT CONTINUES EASING UP AS THE SOUTHERN EDGE OF THE RIDGE
AXIS CENTERED TO THE NORTH CONTINUES PUSHING SOUTHWARD INTO THE
CENTRAL PLAINS IN THE WAKE OF THE DEPARTING LOW THAT REACHES THE
LAKE HURON AREA BY SUNSET. SPEED-WISE...BY MID-DAY SUSTAINED
SPEEDS SHOULD AVERAGE ONLY AROUND 15 MPH IN EASTERN ZONES...AND NO
MORE THAN 10-15 MPH IN WESTERN COUNTIES...AND BY NIGHTFALL THE
ENTIRE CWA SHOULD BE DOWN TO ONLY 5-10 MPH. AS MENTIONED...SKY
COVER/TEMPS ARE REALLY THE FORECAST CHALLENGE OF THE DAY. MODELS
SUCH AS THE 06Z NAM CLEARLY HOLD ONTO PLENTIFUL LOW LEVEL CLOUD
COVER THROUGH THE ENTIRE DAY WITHIN ROUGHLY THE NORTHEAST 1/2 OF
THE CWA...BUT DO SHOW AT LEAST SEVERAL HOURS OF MOSTLY SUNNY-
PARTLY CLOUDY POTENTIAL OVER MUCH OF THE SOUTHWESTERN 1/2.
ALTHOUGH THE LATEST HRRR LOW LEVEL SKY COVER PRODUCT SPORTS A
SIMILAR THEME...IT SUGGESTS THAT SOME OF THE CLEARING THAT OCCURS
COULD FILL BACK IN AS MORE CLOUDS ADVECT IN FROM THE NORTH-
NORTHWEST. EVEN IF PARTS OF THE CWA DO ENJOY APPRECIABLE CLEARING
AND WELCOMED SUNSHINE THROUGH MUCH OF THE DAY...ESPECIALLY THE
LATER AFTERNOON HOURS SHOULD BRING A GRADUAL INCREASE IN MID-HIGH
CLOUDS STREAMING IN FROM THE WEST IN ASSOCIATION WITH A WEAK/LOW
AMPLITUDE SHORTWAVE TROUGH WELL OUT AHEAD OF THE LARGER WESTERN
TROUGH. SO IN SUMMARY...GENERALLY EXPECT MOSTLY CLOUDY SKIES
NORTHEAST 1/2 TODAY...AND MOSTLY SUNNY-PARTLY CLOUDY
SOUTHWEST ESPECIALLY KS ZONES...BUT SOME VARIATION FROM THIS IS
LIKELY AS WELL. OBVIOUSLY THIS TRICKY SKY COVER WILL WORK IN
CONCERT WITH THE GENERALLY 1-3 INCHES OF SNOW COVER IN PLACE OVER
SEVERAL NORTHERN/WESTERN COUNTIES TO MAKE HIGH TEMPS A BIT
CHALLENGING AS WELL. WITH RAW MET/MAV GUIDANCE LOOKING A BIT TOO
COOL ESPECIALLY IN SOUTHERN ZONES...OPTED TO MAKE ONLY MINOR
TWEAKS TO PREVIOUS FORECAST BY TRYING TO STRIKE SOME KIND OF
BALANCE BETWEEN VARIABLE SNOW COVER AND SKY COVER. THE NET
RESULT...ALTHOUGH NOT OVERLY CONFIDENT...YIELDS ONLY MID-UPPER 20S
WITHIN MANY NORTHERN/WESTERN NEB COUNTIES...MAINLY LOW 30S IN
EASTERN/SOUTHERN NEB ZONES...AND GENERALLY MID 30S IN KS ZONES.
TURNING TO THIS EVENING/TONIGHT...THE MID-UPPER LEVEL PICTURE
FEATURES THE AFOREMENTIONED/RATHER SUBTLE LEAD SHORTWAVE
DISTURBANCE CROSSING OVER THE LOCAL AREA...WHILE MORE ENERGETIC
WAVES REMAIN WELL OFF TO THE WEST-SOUTHWEST. MEANWHILE AT THE
SURFACE...THE RIDGE AXIS WILL SLOWLY EDGE EASTWARD. ALTHOUGH WIND
SPEEDS SHOULD REMAIN LIGHT GENERALLY WELL-UNDER 10 MPH THROUGH THE
ENTIRE NIGHT...DIRECTION WILL GRADUALLY TRANSITION FROM NORTHERLY
TO EASTERLY. DESPITE THE FAIRLY WEAK NATURE OF THE PASSING
DISTURBANCE...MODEL RELATIVE HUMIDITY PROGS DEPICT A FAIRLY DECENT
COVERAGE OF MID-HIGH CLOUD COVER THROUGH THE NIGHT...AND HAVE THE
ENTIRE CWA IN PARTLY TO MOSTLY CLOUDY SKY COVER CATEGORY. WHILE
CONFIDENCE IS FAIRLY HIGH IN A PRECIP-FREE NIGHT (ESPECIALLY
MEASURABLE) AND THE OFFICIAL FORECAST REFLECTS SUCH...WOULD NOT BE
TOTALLY SURPRISED TO SEE A WEST-EAST ORIENTED BAND OF FLURRIES
TRY TO GET GOING LATE IN THE NIGHT MAINLY OVER/NEAR THE NORTHERN
CWA IN RESPONSE TO SOME FAIRLY MODEST ISENTROPIC LIFT/FRONTOGENESIS
FOCUSED IN THE ENTRANCE REGION OF A DEPARTING UPPER JET STREAK.
DESPITE THE LIGHT BREEZES...THE EXPECTED FAIRLY HIGH SKY COVER
SHOULD KEEP TEMPS FROM REALLY FALLING OFF...AND AS A RESULT KEPT
LOW TEMPS GENERALLY 2-4 DEGREES ABOVE A 00Z MET/MAV GUIDANCE
BLEND...AIMING MOST OF THE CWA INTO THE 15-20 RANGE...EXCEPT FOR
COLDER READINGS AROUND 10 FAR NORTH. LASTLY...DESPITE FAIRLY HIGH
VALUES OF FORECAST LOW-LEVEL RELATIVE HUMIDITY...CONFIDENCE WAS
NOT SUFFICIENT ENOUGH IN FOG FORMATION TO INTRODUCE EVEN A PATCHY
MENTION FOR LATE TONIGHT...ALTHOUGH 03Z SREF/06Z NAM VISIBILITY
PROGS SUGGEST THAT MAYBE LOCALIZED POCKETS OF MAINLY THE FAR
WESTERN CWA COULD BEAR WATCHING FOR THIS...ESPECIALLY IF ENOUGH
SNOW MANAGES TO MELT TODAY TO ENHANCE LOW-LEVEL MOISTURE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 457 AM CST TUE DEC 16 2014
THE BIGGEST CHALLENGE CONTINUES TO BE DETERMINING CHANCES OF
PRECIPITATION...AS WELL AS POTENTIAL TYPE OF PRECIPITATION WEDNESDAY
NIGHT THROUGH THURSDAY NIGHT.
MODELS ARE COMING IN BETTER AGREEMENT WITH A LONGWAVE TROUGH OVER
THE GREAT BASIN EJECTING A LOW-AMPLITUDE WAVE INTO THE SOUTH CENTRAL
PLAINS. THIS WILL BE A FAIRLY QUICK HITTER...DROPPING SOME QUICK
LIGHT SNOW WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING...WITH
POTENTIALLY SOME LINGERING FLURRIES FOR THURSDAY AFTERNOON/NIGHT. AT
TIMES...IT APPEARS THAT WE COULD HAVE A LOSS OF SATURATION IN MID-
LEVELS. THIS IS GENERALLY LOWER THAN THE DENDRITIC GROWTH ZONE.
THERE IS NOT WIDESPREAD AGREEMENT WITH THIS. WAS THINKING ABOUT
STICKING IN POTENTIAL LIGHT FREEZING DRIZZLE FOR THURSDAY
NIGHT...BUT THE WAVE SHOULD BE FAR ENOUGH EAST THAT I HAVE DOUBTS
THAT MUCH OF ANY PRECIPITATION WILL FALL AT ALL. I STUCK IN A SLIGHT
CHANCE OF FLURRIES FOR THURSDAY AFTERNOON/NIGHT...AS THE NAM DOES
ADVERTISE SOME SPARSE NON-MEASURABLE PRECIPITATION...BUT THIS DOES
NOT LOOK LIKELY BY ANY MEANS.
I KEPT PRECIPITATION OUT OF FRIDAY AS THE MAIN WAVE IS TRENDING
FARTHER SOUTH...WITH THE ASSOCIATED ENERGY FAR TOO SOUTH TO GIVE US
A CHANCE OF PRECIPITATION.
THE FORECAST IS DRY FOR THE WEEKEND INTO MONDAY...HOWEVER
PROGRESSIVE WEST/NORTHWEST FLOW MAKES THINGS A BIT UNCERTAIN AS
SMALL WAVES AND PERTURBATIONS MAY NECESSITATE SOME CHANCES OF
PRECIPITATION DOWN THE ROAD...ESPECIALLY TOWARD MONDAY...DEPENDING
ON TIMING AND PLACEMENT OF WAVES/PERTURBATIONS.
THERE WILL BE A SLOW AND STEADY INCREASE OF TEMPERATURES DURING THE
LONG TERM FORECAST...YET REMAINING FAIRLY SEASONABLE.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 555 AM CST TUE DEC 16 2014
ALTHOUGH CONFIDENCE IS RATHER HIGH IN BOTH WIND SPEEDS/DIRECTION
AND THE FACT THAT VFR VISIBILITY SHOULD PREVAIL...UNFORTUNATELY
THE SAME QUESTION MARKS REGARDING CEILING TRENDS
CONTINUE...INVOLVING WHEN A RETURN TO VFR MIGHT OCCUR FROM THE
PRESENT MVFR STRATUS SITUATION AND IF SO FOR HOW LONG. GIVEN THAT
THE LAST THREE TAF ISSUANCES HAVE JUST CONTINUED TO DELAY THE
RETURN OF VFR CEILING...OPTED TO SIMPLY "SELL OUT" TO PERSISTENCE
THIS TIME AROUND AND MAINTAIN MVFR THROUGH THE ENTIRE PERIOD AND
BE PLEASANTLY SURPRISED IF VFR RETURNS AT SOME POINT. NO MATTER
WHAT CEILINGS DO...CONFIDENCE IS HIGH IN A PRECIPITATION-FREE
PERIOD. WIND-WISE...DECREASING SPEEDS WILL BE THE MAIN STORY
THROUGH THE PERIOD. RIGHT AWAY THIS MORNING...GUST POTENTIAL OF AT
LEAST 20-25KT WILL CONTINUE...BUT BY MID-DAY PEAK GUSTS SHOULD
EASE DOWN INTO THE 15-20KT RANGE...WITH FAIRLY LIGHT BREEZES THEN
IN PLACE FOR THIS EVENING-TONIGHT AS DIRECTION CHANGES FROM
NORTHERLY TO EASTERLY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...HEINLEIN
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
501 AM CST TUE DEC 16 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CST TUE DEC 16 2014
WITH LITTLE TO NO RISK OF PRECIPITATION DURING THESE NEXT 24
HOURS...THE MAIN FORECAST CHALLENGE CENTERS AROUND
TEMPERATURES/SKY COVER...AND THE OBVIOUS AFFECT ONE HAS ON THE
OTHER...ALONG WITH ANY INFLUENCE ON TEMPS FROM SNOW COVER IN
NORTHERN/WESTERN COUNTIES.
STARTING OFF WITH THE HERE AND NOW AS OF 0900Z/3AM...ITS
CERTAINLY BEEN A MUCH QUIETER NIGHT THAN THE PRECEDING ONE...AS
ANY MEASURABLE PRECIP ASSOCIATED WITH THE DEPARTING LOW PRESSURE
SYSTEM IS NOW WELL-EAST INTO EASTERN IA. IN THE MID AND UPPER
LEVELS...WATER VAPOR SATELLITE AND SHORT TERM MODEL DATA CLEARLY
DEPICT THE CENTER OF THE CLOSED 500 MILLIBAR LOW OVER NORTHERN
IL...WHILE UPSTREAM FROM IT...THE LEADING EDGE OF A BROAD
SHORTWAVE RIDGE AND ASSOCIATED HEIGHT RISES IS STARTING TO
OVERSPREAD THE LOCAL AREA...WITH THE RIDGE AXIS GENERALLY ALIGNED
NORTH-SOUTH THROUGH THE ROCKIES. FARTHER WEST...THE NEXT BROAD
TROUGH IS IN THE PROCESS OF COMING ONSHORE THE WEST COAST...WHICH
WILL PROVIDE PLENTY OF CHALLENGES LOCALLY IN THE DAYS 2-4 PERIOD
AS COVERED IN THE LONG TERM SECTION BELOW. AT THE
SURFACE...CERTAINLY THE BIG STORY OVERNIGHT HAS BEEN CONTINUED
FAIRLY STRONG NORTHWEST WINDS...ALTHOUGH THEY ARE ON A SLOW-BUT-
STEADY DOWNWARD TREND AS THE PRESSURE GRADIENT STARTS TO RELAX IN
THE WAKE OF THE DEPARTING 1004MB LOW OVER NORTHERN IL...AND AS A
BROAD RIDGE AXIS CENTERED AT AROUND 1030MB OVER THE DAKOTAS/SOUTH
CENTRAL CANADA STARTS TO EXERT INCREASING INFLUENCE LOCALLY. AS OF
THIS TIME HOWEVER...SUSTAINED SPEEDS OF AT LEAST 20-25 MPH ARE
HANGING ON IN EASTERN ZONES WITH HIGHER GUSTS...AND MORE SO 15-20
MPH IN WESTERN ZONES. EARLIER IN THE NIGHT...THERE WERE LAW
ENFORCEMENT REPORTS OF SOME DICEY TRAVEL CONDITIONS DUE TO SLICK
ROADS/LIMITED BLOWING SNOW IN/NEAR THE FAR NORTHERN CWA COUNTIES
OF VALLEY/GREELEY...BUT FORTUNATELY THE DECREASING SPEEDS SHOULD
AT LEAST IMPROVE THIS SITUATION SLIGHTLY. ACTUALLY THE NUMBER ONE
VERY SHORT-TERM CHALLENGE IS SKY COVER...AS WHILE THE MAJORITY OF
THE CWA REMAINS UNDER A BROAD LOW STRATUS DECK AROUND 1500 FT
AGL...AN AREA OF CLEARING HAS RECENTLY BROKEN OUT OVER SOUTHWEST
COUNTIES. TEMP-WISE...AS SUSPECTED 24 HOURS THE COMBO OF CLOUDS
AND/OR BRISK BREEZES IS HOLDING UP THINGS FAIRLY WELL...AND
ALTHOUGH SOME DROPS COULD YET OCCUR AROUND SUNRISE...THINK THE
MAJORITY OF THE CWA SHOULD HOLD UP NO COLDER THAN THE 17-20 RANGE.
LOOKING FORWARD INTO THE DAYTIME FORECAST AND STARTING WITH THE
MID-UPPER LEVEL SCENE...THE AFOREMENTIONED BROAD RIDGE AXIS
OVERSPREADS THE CENTRAL PLAINS BUT FLATTENS A BIT AS IT DOES SO.
AT THE SURFACE...CERTAINLY THE MOST NOTICEABLE CHANGE FROM MONDAY
WILL BE THE DECREASING NORTHWESTERLY WINDS...AS THE PRESSURE
GRADIENT CONTINUES EASING UP AS THE SOUTHERN EDGE OF THE RIDGE
AXIS CENTERED TO THE NORTH CONTINUES PUSHING SOUTHWARD INTO THE
CENTRAL PLAINS IN THE WAKE OF THE DEPARTING LOW THAT REACHES THE
LAKE HURON AREA BY SUNSET. SPEED-WISE...BY MID-DAY SUSTAINED
SPEEDS SHOULD AVERAGE ONLY AROUND 15 MPH IN EASTERN ZONES...AND NO
MORE THAN 10-15 MPH IN WESTERN COUNTIES...AND BY NIGHTFALL THE
ENTIRE CWA SHOULD BE DOWN TO ONLY 5-10 MPH. AS MENTIONED...SKY
COVER/TEMPS ARE REALLY THE FORECAST CHALLENGE OF THE DAY. MODELS
SUCH AS THE 06Z NAM CLEARLY HOLD ONTO PLENTIFUL LOW LEVEL CLOUD
COVER THROUGH THE ENTIRE DAY WITHIN ROUGHLY THE NORTHEAST 1/2 OF
THE CWA...BUT DO SHOW AT LEAST SEVERAL HOURS OF MOSTLY SUNNY-
PARTLY CLOUDY POTENTIAL OVER MUCH OF THE SOUTHWESTERN 1/2.
ALTHOUGH THE LATEST HRRR LOW LEVEL SKY COVER PRODUCT SPORTS A
SIMILAR THEME...IT SUGGESTS THAT SOME OF THE CLEARING THAT OCCURS
COULD FILL BACK IN AS MORE CLOUDS ADVECT IN FROM THE NORTH-
NORTHWEST. EVEN IF PARTS OF THE CWA DO ENJOY APPRECIABLE CLEARING
AND WELCOMED SUNSHINE THROUGH MUCH OF THE DAY...ESPECIALLY THE
LATER AFTERNOON HOURS SHOULD BRING A GRADUAL INCREASE IN MID-HIGH
CLOUDS STREAMING IN FROM THE WEST IN ASSOCIATION WITH A WEAK/LOW
AMPLITUDE SHORTWAVE TROUGH WELL OUT AHEAD OF THE LARGER WESTERN
TROUGH. SO IN SUMMARY...GENERALLY EXPECT MOSTLY CLOUDY SKIES
NORTHEAST 1/2 TODAY...AND MOSTLY SUNNY-PARTLY CLOUDY
SOUTHWEST ESPECIALLY KS ZONES...BUT SOME VARIATION FROM THIS IS
LIKELY AS WELL. OBVIOUSLY THIS TRICKY SKY COVER WILL WORK IN
CONCERT WITH THE GENERALLY 1-3 INCHES OF SNOW COVER IN PLACE OVER
SEVERAL NORTHERN/WESTERN COUNTIES TO MAKE HIGH TEMPS A BIT
CHALLENGING AS WELL. WITH RAW MET/MAV GUIDANCE LOOKING A BIT TOO
COOL ESPECIALLY IN SOUTHERN ZONES...OPTED TO MAKE ONLY MINOR
TWEAKS TO PREVIOUS FORECAST BY TRYING TO STRIKE SOME KIND OF
BALANCE BETWEEN VARIABLE SNOW COVER AND SKY COVER. THE NET
RESULT...ALTHOUGH NOT OVERLY CONFIDENT...YIELDS ONLY MID-UPPER 20S
WITHIN MANY NORTHERN/WESTERN NEB COUNTIES...MAINLY LOW 30S IN
EASTERN/SOUTHERN NEB ZONES...AND GENERALLY MID 30S IN KS ZONES.
TURNING TO THIS EVENING/TONIGHT...THE MID-UPPER LEVEL PICTURE
FEATURES THE AFOREMENTIONED/RATHER SUBTLE LEAD SHORTWAVE
DISTURBANCE CROSSING OVER THE LOCAL AREA...WHILE MORE ENERGETIC
WAVES REMAIN WELL OFF TO THE WEST-SOUTHWEST. MEANWHILE AT THE
SURFACE...THE RIDGE AXIS WILL SLOWLY EDGE EASTWARD. ALTHOUGH WIND
SPEEDS SHOULD REMAIN LIGHT GENERALLY WELL-UNDER 10 MPH THROUGH THE
ENTIRE NIGHT...DIRECTION WILL GRADUALLY TRANSITION FROM NORTHERLY
TO EASTERLY. DESPITE THE FAIRLY WEAK NATURE OF THE PASSING
DISTURBANCE...MODEL RELATIVE HUMIDITY PROGS DEPICT A FAIRLY DECENT
COVERAGE OF MID-HIGH CLOUD COVER THROUGH THE NIGHT...AND HAVE THE
ENTIRE CWA IN PARTLY TO MOSTLY CLOUDY SKY COVER CATEGORY. WHILE
CONFIDENCE IS FAIRLY HIGH IN A PRECIP-FREE NIGHT (ESPECIALLY
MEASURABLE) AND THE OFFICIAL FORECAST REFLECTS SUCH...WOULD NOT BE
TOTALLY SURPRISED TO SEE A WEST-EAST ORIENTED BAND OF FLURRIES
TRY TO GET GOING LATE IN THE NIGHT MAINLY OVER/NEAR THE NORTHERN
CWA IN RESPONSE TO SOME FAIRLY MODEST ISENTROPIC LIFT/FRONTOGENESIS
FOCUSED IN THE ENTRANCE REGION OF A DEPARTING UPPER JET STREAK.
DESPITE THE LIGHT BREEZES...THE EXPECTED FAIRLY HIGH SKY COVER
SHOULD KEEP TEMPS FROM REALLY FALLING OFF...AND AS A RESULT KEPT
LOW TEMPS GENERALLY 2-4 DEGREES ABOVE A 00Z MET/MAV GUIDANCE
BLEND...AIMING MOST OF THE CWA INTO THE 15-20 RANGE...EXCEPT FOR
COLDER READINGS AROUND 10 FAR NORTH. LASTLY...DESPITE FAIRLY HIGH
VALUES OF FORECAST LOW-LEVEL RELATIVE HUMIDITY...CONFIDENCE WAS
NOT SUFFICIENT ENOUGH IN FOG FORMATION TO INTRODUCE EVEN A PATCHY
MENTION FOR LATE TONIGHT...ALTHOUGH 03Z SREF/06Z NAM VISIBILITY
PROGS SUGGEST THAT MAYBE LOCALIZED POCKETS OF MAINLY THE FAR
WESTERN CWA COULD BEAR WATCHING FOR THIS...ESPECIALLY IF ENOUGH
SNOW MANAGES TO MELT TODAY TO ENHANCE LOW-LEVEL MOISTURE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 457 AM CST TUE DEC 16 2014
THE BIGGEST CHALLENGE CONTINUES TO BE DETERMINING CHANCES OF
PRECIPITATION...AS WELL AS POTENTIAL TYPE OF PRECIPITATION WEDNESDAY
NIGHT THROUGH THURSDAY NIGHT.
MODELS ARE COMING IN BETTER AGREEMENT WITH A LONGWAVE TROUGH OVER
THE GREAT BASIN EJECTING A LOW-AMPLITUDE WAVE INTO THE SOUTH CENTRAL
PLAINS. THIS WILL BE A FAIRLY QUICK HITTER...DROPPING SOME QUICK
LIGHT SNOW WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING...WITH
POTENTIALLY SOME LINGERING FLURRIES FOR THURSDAY AFTERNOON/NIGHT. AT
TIMES...IT APPEARS THAT WE COULD HAVE A LOSS OF SATURATION IN MID-
LEVELS. THIS IS GENERALLY LOWER THAN THE DENDRITIC GROWTH ZONE.
THERE IS NOT WIDESPREAD AGREEMENT WITH THIS. WAS THINKING ABOUT
STICKING IN POTENTIAL LIGHT FREEZING DRIZZLE FOR THURSDAY
NIGHT...BUT THE WAVE SHOULD BE FAR ENOUGH EAST THAT I HAVE DOUBTS
THAT MUCH OF ANY PRECIPITATION WILL FALL AT ALL. I STUCK IN A SLIGHT
CHANCE OF FLURRIES FOR THURSDAY AFTERNOON/NIGHT...AS THE NAM DOES
ADVERTISE SOME SPARSE NON-MEASURABLE PRECIPITATION...BUT THIS DOES
NOT LOOK LIKELY BY ANY MEANS.
I KEPT PRECIPITATION OUT OF FRIDAY AS THE MAIN WAVE IS TRENDING
FARTHER SOUTH...WITH THE ASSOCIATED ENERGY FAR TOO SOUTH TO GIVE US
A CHANCE OF PRECIPITATION.
THE FORECAST IS DRY FOR THE WEEKEND INTO MONDAY...HOWEVER
PROGRESSIVE WEST/NORTHWEST FLOW MAKES THINGS A BIT UNCERTAIN AS
SMALL WAVES AND PERTURBATIONS MAY NECESSITATE SOME CHANCES OF
PRECIPITATION DOWN THE ROAD...ESPECIALLY TOWARD MONDAY...DEPENDING
ON TIMING AND PLACEMENT OF WAVES/PERTURBATIONS.
THERE WILL BE A SLOW AND STEADY INCREASE OF TEMPERATURES DURING THE
LONG TERM FORECAST...YET REMAINING FAIRLY SEASONABLE.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1208 AM CST TUE DEC 16 2014
ALTHOUGH CONFIDENCE IS RATHER HIGH IN BOTH WIND SPEEDS/DIRECTION
AND THE FACT THAT VFR VISIBILITY SHOULD PREVAIL...UNFORTUNATELY
THERE ARE SOME QUESTION MARKS REGARDING CEILING TRENDS...INVOLVING
BOTH WHEN A RETURN TO VFR MIGHT OCCUR AND IF SO FOR HOW LONG. IN
SHORT...OPTED TO ERR A BIT MORE ON THE CAUTIOUS/PESSIMISTIC SIDE
VERSUS PREVIOUS TAF ISSUANCE AND EXTEND AN MVFR CEILING THROUGH
18Z...WITH SOME MODELS/GUIDANCE SUGGESTING THIS MAY BE TOO
LONG...WHILE OTHERS SUGGEST IT MAY NOT BE LONG ENOUGH WITH THE
POTENTIAL FOR MVFR THROUGHOUT THE ENTIRE PERIOD. SO FOR NOW AM
JUST PLAYING A MIDDLE-GROUND. NO MATTER WHAT CEILINGS
DO...CONFIDENCE IS HIGH IN A PRECIPITATION-FREE PERIOD. WIND-
WISE...THINGS START OUT QUITE BRISK EARLY THIS MORNING WITH
SEVERAL MORE HOURS OF NORTHWESTERLY GUST POTENTIAL TO AROUND 30KT
POSSIBLE...ALTHOUGH A SLOW-BUT-STEADY DECREASING TREND WILL TAKE
PLACE DURING THE PERIOD WITH GUST POTENTIAL BY MID-DAY EASING
BELOW 20KT...AND IN FACT FAIRLY LIGHT BREEZES IN PLACE BY TUESDAY
EVENING AS HIGH PRESSURE SETTLES IN.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...HEINLEIN
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1050 AM EST TUE DEC 16 2014
.SYNOPSIS...A COLD FRONT WILL PUSH EAST THROUGH THE REGION TODAY.
HIGH PRESSURE WILL BUILD SLOWLY INTO THE AREA THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM TUESDAY...
MORNING UPDATE WILL TWEAK POPS UPWARDS TO LIKELY IN THE CENTRAL AND
EAST INTO THE MID AFTERNOON AND DOWNWARD IN THE WEST AS THE
PREFRONTAL BAND RACES EAST. ALSO ADJUSTING TEMP TRENDS AS WARM AIR
ADVECTION AHEAD OF SHOWERS HAS PRODUCED A WIDE RANGE OF TEMPS...FROM
MID 40S TO UPPER 50S.
TODAY: WEAKENING SOUTHERN STREAM TROUGH ENTERING THE OHIO VALLEY
WILL WILL MOVE EAST-NORTHEASTWARD INTO THE GREAT LAKES AND MID-
ATLANTIC REGION TODAY. PRE-FRONTAL BAND OF CONVECTION(CURRENTLY
APPROACHING THE MOUNTAINS)EMBEDDED IN THE LLJ ASSOCIATED WITH THE
WARM CONVEYOR BELT WILL TRANSLATE QUICKLY EASTWARD ACROSS THE AREA
BETWEEN 12 TO 21Z...BRINGING A BRIEF 2 TO 3 HOUR WINDOW OF SCATTERED
SHOWERS AS MOISTURE PROFILES CONTINUE TO LOOK MODEST...PRIMARILY
CONFINED TO THE 850-700 MB LAYER. AS SUCH...HAVE CHOSEN TO KEEP
POPS AT HIGH CHANCE WITH ONLY LIGHT PRECIP AMOUNTS EXPECTED OF A
TENTH OF AN OR LESS. AS THE CONVEYOR BELT SHIFTS OFFSHORE...MID-
LEVEL DRYING WILL RACE EASTWARD...AHEAD OF THE SFC COLD FRONTAL
PASSAGE WHICH WILL RESULT ONLY ISOLATED SHOWERS ALONG THE IMMEDIATE
FRONT. CANNOT RULE OUT A RUMBLE OF THUNDER AS SOUNDINGS SHOW VERY
WEAK INSTABILITY ALOFT (200-350J/KG OF MUCAPE)...BUT WILL NOT
INCLUDE ANY MENTION AT THIS TIME.
BOTH THE GFS AND NAM BUFR SOUNDINGS SUGGEST THAT THE RAIN AND
LINGERING LOW CLOUDS WILL SUPPRESS TEMPERATURES IN THE MID/UPPER
50S...COOLER THAN PREVIOUS FORECAST AND IN-LINE WITH COOLER MET
STATISTICAL GUIDANCE. THE EXCEPTION MAY BE ACROSS THE FAR SE...WHERE
LATER ARRIVAL OF PRECIP COULD ALLOW TEMPS TO WARM INTO THE LOWER
60S.
TONIGHT: CLEARING WILL SPREAD EASTWARD LATE THIS EVENING IN THE WAKE
OF THE COLD FRONT. A LIGHT NWLY BREEZE WILL KEEP THINGS STIRRED UP
OVERNIGHT WITH RESULTANT WEAK CAA SUPPORTING OVERNIGHT LOWS IN THE
MID/UPPER 30S NW TO LOWER 40S SE.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 240 AM TUESDAY...
FAIR WEATHER IS EXPECTED ON WEDNESDAY AS THE UPPER FLOW BECOMES
ZONAL BEHIND THE UPPER TROUGH THAT MOVES OFF THE COAST TUESDAY
NIGHT. AT THE SURFACE...HIGH PRESSURE OVER THE CENTRAL US WILL BE
VERY SLOW TO BUILD EASTWARD WITH NEUTRAL TEMPERATURE ADVECTION AT
850MB NOTED...WHICH SHOULD SUPPORT NEAR TO SLIGHTLY ABOVE NORMAL
HIGHS IN THE MID TO UPPER 50S.
AN ACTIVE PACIFIC WAVE TRAIN MOVING ONSHORE ACROSS CALIFORNIA AND
THEN THROUGH THE SOUTHWEST WILL REINVIGORATE THE PACIFIC JET THAT
EXTENDS ACROSS THE SOUTHERN CONUS. AN OPAQUE CIRRUS SHIELD COULD
SPREAD EAST INTO THE AREA AS EARLY AS WEDNESDAY AFTERNOON BUT
DEFINITELY BY WEDNESDAY NIGHT. THIS CLOUD COVER SHOULD TEMPER MIN
TEMPS...AND COULD QUITE POSSIBLY RESULT IN A NON-DIURNAL TEMPERATURE
TREND WITH TEMPERATURES HOLDING STEADY OR RISING AFTER MIDNIGHT.
LOWS IN MIDS 30S TO UPPER 30S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 245 AM TUESDAY...
THROUGH FRIDAY: SURFACE HIGH PRESSURE WILL CONTINUE TO RIDGE INTO
THE REGION THROUGH FRIDAY. THE ZONAL FLOW ALOFT WILL SLOWLY BECOME
MORE AMPLIFIED THROUGH THIS PERIOD...WITH GENERALLY WEST-NORTHWEST
FLOW OVER CENTRAL NC. EXPECT DRY WEATHER TO DOMINATE DURING THIS
TIME...HOWEVER THE MODELS ARE TRYING TO GENERATE SOME LIGHT PRECIP
FOR A BRIEF PERIOD ON THURSDAY...MAINLY IN THE FAR NW. FOR NOW WILL
KEEP THIS PART OF THE FORECAST DRY UNTIL THE MODELS SHOW A BIT MORE
RUN-TO-RUN CONSISTENCY WITH THE PRECIP. HIGHS IN THE UPPER 40S NORTH
TO MAINLY MID 50S SOUTH THURSDAY AND FRIDAY. EXPECT THURSDAY NIGHT
LOWS MAINLY IN THE LOW TO MID 30S.
FRIDAY NIGHT SATURDAY NIGHT: EXPECT RAPIDLY INCREASING CLOUDINESS
FRIDAY NIGHT AS A LOW PRESSURE SYSTEM APPROACHES FROM THE GULF. THE
INCREASED CLOUD COVER MAY YIELD LOWS A FEW DEGREES HIGHER THAN
PREVIOUS NIGHTS...GENERALLY IN THE MID 30S. IT APPEARS AS THOUGH THE
MODELS HAVE TRENDED TOWARD ONE ANOTHER OVER THE PAST FEW RUNS WITH
RESPECT TO THE APPROACHING UPPER LEVEL TROUGH/SHORTWAVE AND SURFACE
LOW. THE ECMWF IS STILL A BIT MORE AMPLIFIED THAN THE GFS ALOFT...
BUT THEY ARE MUCH CLOSER THAN PREVIOUS RUNS. THE GFS IS STILL JUST A
BIT FASTER...LARGELY DUE TO THE TROUGH BEING LESS AMPLIFIED...BUT
BOTH HAVE PRECIP MOVING INTO THE AREA FROM THE WEST-SOUTHWEST BY 12Z
SATURDAY. FOR NOW EXPECT TEMPS ACROSS OUR AREA TO REMAIN ABOVE
FREEZING FRIDAY NIGHT...THUS DO NOT EXPECT ANY WINTERY PRECIP AT
THIS TIME. HOWEVER...IF THE HIGH RIDGING IN FROM THE NE FRIDAY NIGHT
RESULTS IN TEMPS FALLING BELOW FREEZING THE CHANCE FOR PRECIP OF THE
FROZEN VARIETY MAY BE IN THE REALM OF POSSIBILITY. THE SURFACE LOW
IS EXPECTED TO MOVE ALONG THE GULF COAST AND UP ALONG THE CAROLINA
COAST SATURDAY AND SATURDAY NIGHT AND PRECIP CHANCES AND AMOUNT WILL
DEPEND ON THE EXACT TRACK THE LOW TAKES AS IT MOVES THROUGH THE
REGION. GIVEN THE CURRENT LOW TRACK...ANY THUNDERSTORMS WILL BE
LIMITED TO THE FAR SOUTHEAST AND COASTAL AREAS. TEMPS WILL ALSO
DEPEND ON WHERE THE LOW TRACKS...BUT FOR NOW EXPECT HIGHS AROUND 40
DEGREES IN THE NW TO LOW 50S IN THE SE. OVERNIGHT LOWS VERY SIMILAR
TO FRIDAY NIGHT...MAINLY IN THE MID 30S.
SUNDAY AND MONDAY: THE MAIN UPPER LEVEL SHORTWAVE MOVES OUT OF THE
REGION TO THE NORTHEAST SUNDAY MORNING...WHILE THE SURFACE LOW
REMAINS OFF THE COAST OF THE CAROLINAS THROUGH THE DAY. THE MODELS
INDICATE THE CHANCE FOR SOME LIGHT PRECIP TO LINGER ACROSS THE EAST
THROUGH SUNDAY AS THE SURFACE LOW REMAINS IN CLOSE PROXIMITY... WITH
CHANCES DECREASING LATE SUNDAY AND SUNDAY NIGHT AS THE LOW RAPIDLY
MOVES OFF TO THE NE AND AWAY FROM NC. FOR NOW...EXPECT SUNDAY NIGHT
AND MONDAY TO BE DRY. HIGHS SUNDAY AND MONDAY WILL GENERALLY BE IN
THE MID 40S NORTH TO AROUND 50S DEGREES SOUTH...WITH OVERNIGHT LOWS
IN THE UPPER 20S TO LOW 30S.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 648 AM TUESDAY...
24 HOUR TAF PERIOD: LIFR TO IFR RESTRICTIONS IN FOG HAVE DEVELOPED
ACROSS THE EAST. HRRR SUGGESTS THESE VISIBILITY RESTRICTIONS AND LOW
CLOUDS COULD LINGER THROUGH THE LATE MORNING ~15 TO 16Z. A PRE-
FRONTAL BAND OF SHOWERS WILL CROSS THE AREA BETWEEN 14 TO 17Z IN THE
WEST...EXITING EASTERN TERMINALS AOA 21Z. FCST SOUNDINGS AND
UPSTREAM TRENDS SUGGEST CIGS WILL LOWER TO MVFR WITHIN THE BAND OF
SHOWERS AND WILL REMAIN SUB-VFR UNTIL THE TRAILING SFC COLD FRONT
CROSSES THE AREA DURING THE EARLY EVENING...WITH CLEARING SPREADING
WEST TO EAST BETWEEN 00 TO 06Z.
OUTLOOK...VFR CONDITIONS SHOULD DOMINATE WEDNESDAY THROUGH EARLY
FRIDAY. A LOW PRESSURE SYSTEM TRACKING FROM THE GULF OF MEXICO
NORTHEASTWARD ALONG THE SOUTHEAST COAST WILL RESULT IN ADVERSE
AVIATION CONDITIONS LATE FRIDAY AND INTO THE WEEKEND.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...MLM/CBL
SHORT TERM...CBL
LONG TERM...KC
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
949 AM EST TUE DEC 16 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST TODAY AND MOVE THROUGH THE
AREA TONIGHT. HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST
WEDNESDAY THROUGH FRIDAY. DEVELOPING LOW PRESSURE WILL MOVE ALONG
THE COAST SATURDAY INTO SUNDAY. HIGH PRESSURE IS EXPECTED TO BUILD
OVER THE AREA MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 945 AM TUESDAY...FORECAST ON TRACK FOR THIS AFTERNOON AS THE
3KM HRRR AND NSSL WRF INDICATE BROKEN LINE OF SHOWERS ARRIVE IN
THE 18Z-21Z TIMEFRAME AND WORKING ACROSS THE CWA INTO EARLY
EVENING. INSTABILITY WILL REMAIN LIMITED AS DEWPOINTS WILL HAVE
MINIMAL CHANCE TO RECOVER THIS AFTERNOON AND ANY THUNDER WILL BE
ELEVATED AS THE BEST UPPER SUPPORT MOVES TO THE NORTH OF THE
REGION. KEPT POPS IN THE HIGH CHANCE RANGE BUT QPF TOTALS WILL BE
RELATIVELY LIGHT ON THE ORDER OF 0.1 TO 0.2 INCH. TEMPERATURES ARE
RISING QUICKLY AND SHOULD BE WELL INTO THE 60S BY MIDDAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
AS OF 330 AM TUESDAY...MODELS REMAIN IN FAIRLY CLOSE AGREEMENT WITH
SHRT WV TROF AND ASSCTD SFC COLD FRONT MOVING ACROSS AREA OVERNIGHT.
PER NEAR TERM DISCUSSION...MAIN THREAT OF PCPN WILL BE OVER ERN HALF
OF AREA EARLY EVENING WITH HIGHEST POPS AROUND 50%. PCPN WILL PUSH
OFF COAST BY AROUND MIDNIGHT WITH CLEARING SKIES OVERNIGHT.
MIN TEMPS LOW TO MID 40S INLAND AND AROUND 50 OUTER BANKS.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 325 AM TUE...LONG TERM PERIOD WILL FEATURE A FAIRLY ACTIVE
AND CHANGEABLE WEATHER PATTERN...WITH A SIGNIFICANT STORM SYSTEM
POSSIBLE FOR THE WEEKEND. SFC HIGH PRESSURE WILL BUILD INTO
EASTERN NC FROM THE W/NW WED THROUGH FRI. LOW LEVEL THICKNESS
VALUES AND SUNNY SKIES SUPPORT HIGHS 55-60DEG WED WITH LOW LEVEL
W/NW FLOW. LOW LEVEL THICKNESS VALUES SUPPORT HIGHS IN THE UPPER
40S/MID 50S FOR THU AND FRI WITH SHORTWAVE MOVING NORTH OF THE
AREA AND ZONAL FLOW ACROSS ENC.
A SIGNIFICANT SYSTEM MAY IMPACT THE REGION THIS WEEKEND. THE
PREVIOUS FAVORED ECMWF...NOW BEGINNING TO TREND SIMILAR TO THE
GFS...DEPICTING A WEAKER AND SLOWER SOLUTION. MODELS SHOW WEAK SFC
MOVING THROUGH MEXICO AND SOUTHERN TX THU NIGHT AND FRI... THEN
INTO THE DEEP SOUTH/NORTHERN GULF REGION SATURDAY...EVENTUALLY
INTENSIFYING OFF THE SE COAST LATE SAT INTO SUN NIGHT. THOUGH MUCH
UNCERTAINTY REMAINS WITH TRACK AND INTENSITY OF LOW...THERE WILL BE
THE POTENTIAL FOR HEAVY RAIN...STRONG WINDS...AND MINOR COASTAL
IMPACTS THIS WEEKEND...INCLUDING MINOR WATER LEVEL RISES AND ROUGH
SURF. STILL LOOKS LIKE THE FIRST PART OF THE WEEKEND WILL BE WET
AND CONTINUED LIKELY POPS...WITH MOISTURE TAPERING OFF LATE SUN.
AN ISOLATED CHANCE OF TSTMS STILL POSSIBLE SAT THOUGH VERY
DEPENDENT ON EVENTUAL TRACK OF LOW...WITH BEST CHANCE ALONG THE
COAST AND OFFSHORE.
BOTH GFS/ECMWF SHOW A SOUTHERN STREAM DEVELOPING EARLY NEXT WEEK
AHEAD OF THE UPPER TROUGH...AS THE WEEKEND SFC LOW LIFTS NE OFF
THE NEW ENGLAND COAST. BELOW NORMAL TEMPS EXPECTED FOR SUN/MON
WITH HIGHS IN THE UPPER 40S/LOW 50S AND OVERNIGHT LOWS IN THE 30S.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH 12Z WEDNESDAY/...
AS OF 630 AM TUESDAY...PATCHY FOG AND SOME STRATUS AFFECTING TAF
SITES EARLY THIS MORNING...MAINLY WITH MVFR VSBYS BUT LOCAL LIFR AT
KOAJ. CONDITIONS IMPROVING TO VFR 13Z-14Z AND PREVAILING REST OF TAF
PERIOD OUTSIDE OF SCT SHRA ACTIVITY LATE AFTN INTO EARLY EVENING. SW
WINDS WILL INCREASE TO AROUND 10 KT TODAY AND SHIFT TO W BEHIND
FRONTAL PASSAGE THIS EVENING.
LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 325 AM TUE...PRED VFR CONDITIONS EXPECTED THROUGH MOST OF THE
PERIOD. THERE WILL BE THE POTENTIAL FOR WIDESPREAD SUB-VFR
CONDITIONS TO DEVELOP SATURDAY...AS LOW PRESSURE SYSTEM IS
EXPECTED TO IMPACT EASTERN NC.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 945 AM TUESDAY...LIGHT SOUTHWEST WINDS CONTINUE TO AREA
WATERS WITH SEAS AROUND 2 FEET. WINDS SHOULD VEER TO SOUTHWEST
AHEAD OF AN ONCOMING COLD FRONT AND INCREASE TO 15 TO 20 KNOTS BY
LATE IN THE DAY. ADJUSTED FCST SEAS WITH LATEST
NWPS...INDICATING PERIOD OF 6 FT HEIGHTS FOR OUTER PORTIONS OF SRN
AND CENTRAL WATERS TONIGHT.
LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 325 AM TUE...SFC HIGH PRESSURE WILL BUILD INTO THE REGION FROM
THE W/NW WED THROUGH FRI...RESULTING IN W/NWLY FLOW 10-20KT AND
SEAS 2-4FT. TRENDED WITH WAVEWATCH LATE WED THROUGH FRI...THINKING
THAT LOCAL NWPS IS STILL SLIGHTLY OVERDONE WITH THE OFFSHORE FLOW.
UNCERTAINTY INCREASES THIS WEEKEND WITH THE POTENTIAL FOR ANOTHER
COASTAL LOW DEVELOPING AND IMPACTING THE EASTERN NC WATERS.
PREVIOUS FAVORED MODEL ECMWF...NOW THE 00Z RUN COMING IN MORE
SIMILAR TO THE GFS...DEPICTING A SLIGHTLY WEAKER AND SLOWER SFC
LOW MOVING ALONG THE NC COAST SUN AND SUN NIGHT. CONFIDENCE
REMAINS LOW BUT THERE WILL BE THE POTENTIAL FOR STRONG WINDS TO
GALE FORCE AND HAZARDOUS SEAS THIS WEEKEND.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 5 AM EST
WEDNESDAY FOR AMZ152-154-156-158.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...CQD
AVIATION...JBM/CQD
MARINE...JBM/CTC/CQD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
647 AM EST TUE DEC 16 2014
.SYNOPSIS...A COLD FRONT WILL PUSH EAST THROUGH THE REGION TODAY.
HIGH PRESSURE WILL BUILD SLOWLY INTO THE AREA THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 240 AM TUESDAY...
TODAY: WEAKENING SOUTHERN STREAM TROUGH ENTERING THE OHIO VALLEY
WILL WILL MOVE EAST-NORTHEASTWARD INTO THE GREAT LAKES AND MID-
ATLANTIC REGION TODAY. PRE-FRONTAL BAND OF CONVECTION(CURRENTLY
APPROACHING THE MOUNTAINS)EMBEDDED IN THE LLJ ASSOCIATED WITH THE
WARM CONVEYOR BELT WILL TRANSLATE QUICKLY EASTWARD ACROSS THE AREA
BETWEEN 12 TO 21Z...BRINGING A BRIEF 2 TO 3 HOUR WINDOW OF SCATTERED
SHOWERS AS MOISTURE PROFILES CONTINUE TO LOOK MODEST...PRIMARILY
CONFINED TO THE 850-700 MB LAYER. AS SUCH...HAVE CHOSEN TO KEEP
POPS AT HIGH CHANCE WITH ONLY LIGHT PRECIP AMOUNTS EXPECTED OF A
TENTH OF AN OR LESS. AS THE CONVEYOR BELT SHIFTS OFFSHORE...MID-
LEVEL DRYING WILL RACE EASTWARD...AHEAD OF THE SFC COLD FRONTAL
PASSAGE WHICH WILL RESULT ONLY ISOLATED SHOWERS ALONG THE IMMEDIATE
FRONT. CANNOT RULE OUT A RUMBLE OF THUNDER AS SOUNDINGS SHOW VERY
WEAK INSTABILITY ALOFT (200-350J/KG OF MUCAPE)...BUT WILL NOT
INCLUDE ANY MENTION AT THIS TIME.
BOTH THE GFS AND NAM BUFR SOUNDINGS SUGGEST THAT THE RAIN AND
LINGERING LOW CLOUDS WILL SUPPRESS TEMPERATURES IN THE MID/UPPER
50S...COOLER THAN PREVIOUS FORECAST AND IN-LINE WITH COOLER MET
STATISTICAL GUIDANCE. THE EXCEPTION MAY BE ACROSS THE FAR SE...WHERE
LATER ARRIVAL OF PRECIP COULD ALLOW TEMPS TO WARM INTO THE LOWER
60S.
TONIGHT: CLEARING WILL SPREAD EASTWARD LATE THIS EVENING IN THE WAKE
OF THE COLD FRONT. A LIGHT NWLY BREEZE WILL KEEP THINGS STIRRED UP
OVERNIGHT WITH RESULTANT WEAK CAA SUPPORTING OVERNIGHT LOWS IN THE
MID/UPPER 30S NW TO LOWER 40S SE.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 240 AM TUESDAY...
FAIR WEATHER IS EXPECTED ON WEDNESDAY AS THE UPPER FLOW BECOMES
ZONAL BEHIND THE UPPER TROUGH THAT MOVES OFF THE COAST TUESDAY
NIGHT. AT THE SURFACE...HIGH PRESSURE OVER THE CENTRAL US WILL BE
VERY SLOW TO BUILD EASTWARD WITH NEUTRAL TEMPERATURE ADVECTION AT
850MB NOTED...WHICH SHOULD SUPPORT NEAR TO SLIGHTLY ABOVE NORMAL
HIGHS IN THE MID TO UPPER 50S.
AN ACTIVE PACIFIC WAVE TRAIN MOVING ONSHORE ACROSS CALIFORNIA AND
THEN THROUGH THE SOUTHWEST WILL REINVIGORATE THE PACIFIC JET THAT
EXTENDS ACROSS THE SOUTHERN CONUS. AN OPAQUE CIRRUS SHIELD COULD
SPREAD EAST INTO THE AREA AS EARLY AS WEDNESDAY AFTERNOON BUT
DEFINITELY BY WEDNESDAY NIGHT. THIS CLOUD COVER SHOULD TEMPER MIN
TEMPS...AND COULD QUITE POSSIBLY RESULT IN A NON-DIURNAL TEMPERATURE
TREND WITH TEMPERATURES HOLDING STEADY OR RISING AFTER MIDNIGHT.
LOWS IN MIDS 30S TO UPPER 30S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 245 AM TUESDAY...
THROUGH FRIDAY: SURFACE HIGH PRESSURE WILL CONTINUE TO RIDGE INTO
THE REGION THROUGH FRIDAY. THE ZONAL FLOW ALOFT WILL SLOWLY BECOME
MORE AMPLIFIED THROUGH THIS PERIOD...WITH GENERALLY WEST-NORTHWEST
FLOW OVER CENTRAL NC. EXPECT DRY WEATHER TO DOMINATE DURING THIS
TIME...HOWEVER THE MODELS ARE TRYING TO GENERATE SOME LIGHT PRECIP
FOR A BRIEF PERIOD ON THURSDAY...MAINLY IN THE FAR NW. FOR NOW WILL
KEEP THIS PART OF THE FORECAST DRY UNTIL THE MODELS SHOW A BIT MORE
RUN-TO-RUN CONSISTENCY WITH THE PRECIP. HIGHS IN THE UPPER 40S NORTH
TO MAINLY MID 50S SOUTH THURSDAY AND FRIDAY. EXPECT THURSDAY NIGHT
LOWS MAINLY IN THE LOW TO MID 30S.
FRIDAY NIGHT SATURDAY NIGHT: EXPECT RAPIDLY INCREASING CLOUDINESS
FRIDAY NIGHT AS A LOW PRESSURE SYSTEM APPROACHES FROM THE GULF. THE
INCREASED CLOUD COVER MAY YIELD LOWS A FEW DEGREES HIGHER THAN
PREVIOUS NIGHTS...GENERALLY IN THE MID 30S. IT APPEARS AS THOUGH THE
MODELS HAVE TRENDED TOWARD ONE ANOTHER OVER THE PAST FEW RUNS WITH
RESPECT TO THE APPROACHING UPPER LEVEL TROUGH/SHORTWAVE AND SURFACE
LOW. THE ECMWF IS STILL A BIT MORE AMPLIFIED THAN THE GFS ALOFT...
BUT THEY ARE MUCH CLOSER THAN PREVIOUS RUNS. THE GFS IS STILL JUST A
BIT FASTER...LARGELY DUE TO THE TROUGH BEING LESS AMPLIFIED...BUT
BOTH HAVE PRECIP MOVING INTO THE AREA FROM THE WEST-SOUTHWEST BY 12Z
SATURDAY. FOR NOW EXPECT TEMPS ACROSS OUR AREA TO REMAIN ABOVE
FREEZING FRIDAY NIGHT...THUS DO NOT EXPECT ANY WINTERY PRECIP AT
THIS TIME. HOWEVER...IF THE HIGH RIDGING IN FROM THE NE FRIDAY NIGHT
RESULTS IN TEMPS FALLING BELOW FREEZING THE CHANCE FOR PRECIP OF THE
FROZEN VARIETY MAY BE IN THE REALM OF POSSIBILITY. THE SURFACE LOW
IS EXPECTED TO MOVE ALONG THE GULF COAST AND UP ALONG THE CAROLINA
COAST SATURDAY AND SATURDAY NIGHT AND PRECIP CHANCES AND AMOUNT WILL
DEPEND ON THE EXACT TRACK THE LOW TAKES AS IT MOVES THROUGH THE
REGION. GIVEN THE CURRENT LOW TRACK...ANY THUNDERSTORMS WILL BE
LIMITED TO THE FAR SOUTHEAST AND COASTAL AREAS. TEMPS WILL ALSO
DEPEND ON WHERE THE LOW TRACKS...BUT FOR NOW EXPECT HIGHS AROUND 40
DEGREES IN THE NW TO LOW 50S IN THE SE. OVERNIGHT LOWS VERY SIMILAR
TO FRIDAY NIGHT...MAINLY IN THE MID 30S.
SUNDAY AND MONDAY: THE MAIN UPPER LEVEL SHORTWAVE MOVES OUT OF THE
REGION TO THE NORTHEAST SUNDAY MORNING...WHILE THE SURFACE LOW
REMAINS OFF THE COAST OF THE CAROLINAS THROUGH THE DAY. THE MODELS
INDICATE THE CHANCE FOR SOME LIGHT PRECIP TO LINGER ACROSS THE EAST
THROUGH SUNDAY AS THE SURFACE LOW REMAINS IN CLOSE PROXIMITY... WITH
CHANCES DECREASING LATE SUNDAY AND SUNDAY NIGHT AS THE LOW RAPIDLY
MOVES OFF TO THE NE AND AWAY FROM NC. FOR NOW...EXPECT SUNDAY NIGHT
AND MONDAY TO BE DRY. HIGHS SUNDAY AND MONDAY WILL GENERALLY BE IN
THE MID 40S NORTH TO AROUND 50S DEGREES SOUTH...WITH OVERNIGHT LOWS
IN THE UPPER 20S TO LOW 30S.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 648 AM TUESDAY...
24 HOUR TAF PERIOD: LIFR TO IFR RESTRICTIONS IN FOG HAVE DEVELOPED
ACROSS THE EAST. HRRR SUGGESTS THESE VISIBILITY RESTRICTIONS AND LOW
CLOUDS COULD LINGER THROUGH THE LATE MORNING ~15 TO 16Z. A PRE-
FRONTAL BAND OF SHOWERS WILL CROSS THE AREA BETWEEN 14 TO 17Z IN THE
WEST...EXITING EASTERN TERMINALS AOA 21Z. FCST SOUNDINGS AND
UPSTREAM TRENDS SUGGEST CIGS WILL LOWER TO MVFR WITHIN THE BAND OF
SHOWERS AND WILL REMAIN SUB-VFR UNTIL THE TRAILING SFC COLD FRONT
CROSSES THE AREA DURING THE EARLY EVENING...WITH CLEARING SPREADING
WEST TO EAST BETWEEN 00 TO 06Z.
OUTLOOK...VFR CONDITIONS SHOULD DOMINATE WEDNESDAY THROUGH EARLY
FRIDAY. A LOW PRESSURE SYSTEM TRACKING FROM THE GULF OF MEXICO
NORTHEASTWARD ALONG THE SOUTHEAST COAST WILL RESULT IN ADVERSE
AVIATION CONDITIONS LATE FRIDAY AND INTO THE WEEKEND.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...CBL
SHORT TERM...CBL
LONG TERM...KC
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
743 AM EST TUE DEC 16 2014
.SYNOPSIS...
OCCASIONAL SHOWERS ARE EXPECTED TODAY AS A LOW PRESSURE SYSTEM
LIFTS NORTHEAST INTO THE GREAT LAKES REGION. A COLDER AIRMASS
WILL THEN SETTLE INTO THE REGION WITH SEASONABLY COOLER
TEMPERATURES EXPECTED THROUGH THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A FAIRLY SOLID LINE OF SHOWERS IS CURRENTLY MOVING THROUGH
SOUTHEAST INDIANA AND INTO FAR WESTERN OHIO. THESE SHOWERS ARE
WITHIN A LOW LEVEL CONVERGENT BOUNDARY ASSOCIATED WITH AN
APPROACHING FRONTAL BOUNDARY. VERY MARGINAL INSTABILITY IS WORKING
NORTHEAST INTO SOUTHERN PORTIONS OF OUR FA AND THIS HAS ALLOWED
FOR A FEW EMBEDDED THUNDERSTORMS TO DEVELOP. INTERESTINGLY...THE
SHERB PARAMETER OFF BOTH THE RAP AND NAM SEEMS TO BE PICKING UP
ON SOME OF THIS BETTER FORCING/INSTABILITY...WITH A NARROW AXIS OF
HIGHER VALUES MOVING THROUGH THE TRI STATE REGION OVER THE NEXT
FEW HOURS. AS A RESULT...WILL INCLUDE AN ISOLATED THUNDERSTORM THROUGH
DAYBREAK ACROSS SOUTHWEST PORTIONS OF OUR FA. THE BULK OF THE PCPN
SHOULD CONTINUE TO PIVOT UP ACROSS NORTHERN PORTIONS OF OUR FA
THROUGH LATE MORNING. EXPECT PCPN TO THEN BECOME MORE SCATTERED AS
WE HEAD INTO THIS AFTERNOON AND GET INTO SOME WRAP AROUND
MOISTURE. EXPECT EARLY HIGHS TODAY WITH TEMPERATURES THEN LEVELING
OFF OR EVEN BEGINNING TO FALL AS WE START TO GET INTO SOME
DEVELOPING LOW LEVEL CAA THROUGH THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
THE LOW PRESSURE WILL CONTINUE TO LIFT OFF TO THE NORTHEAST TONIGHT
WITH PCPN TAPERING OFF TO JUST A FEW SHOWERS THROUGH THIS EVENING.
IT STILL LOOKS LIKE THE DEEPER MOISTURE WILL BE EXITING OUR AREA
BEFORE THE BOUNDARY LAYER COOLS OFF ENOUGH FOR MUCH IN THE WAY OF
SNOW. AS A RESULT..WILL JUST ALLOW FOR A BRIEF MIX ACROSS THE
NORTH LATER THIS EVENING AS THE PCPN TAPERS OFF. HIGH PRESSURE
WILL THEN BUILD INTO THE REGION FOR WEDNESDAY INTO THURSDAY.
TEMPERATURES WILL BE SEASONABLY COOL WITH HIGHS ONLY IN THE 30S
WEDNESDAY AND THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
FORECAST PERIOD BEGINS WITH THE MODELS IN AGREEMENT IN PLACING A
STRUNG OUT HIGH PRESSURE SYSTEM FROM THE NORTHERN PLAINS DOWN INTO
THE UPPER OHIO VALLEY. THE HIGH WILL DRIFT SLOWLY EASTWARD PROVIDING
DRY CONDITIONS THROUGH FRIDAY.
THE GFS CONTINUES WITH ITS STRUGGLES IN DEALING WITH ENERGY SWINGING
OUT OF THE LOWER MS VALLEY FRIDAY. AFTER WINDING UP A LOW AND
LIFTING IT N INTO THE REGION WITH YESTERDAYS RUN...THE GFS NOW TAKES
A QUICK MOVING SHEARED OUT H5 VORT INTO THE TN VALLEY AND SPREADS
PCPN INTO SOUTHERN PORTIONS OF THE REGION MUCH QUICKER THAN THE
OTHER MODELS FRIDAY NIGHT. THE ECMWF HAS BEEN CONSISTENT WITH ITS
SOLUTION OF A TAKING A SLOWER A MORE DEFINED SFC LOW INTO THE
CAROLINAS FRIDAY NIGHT INTO SATURDAY. WILL CONTINUE TO FOLLOW THE
ECMWF SOLUTION AS IT IS BACKED BY THE CONSENSUS OF THE MODELS.
SO BROUGHT SOME SLIGHT CHANCE/CHANCE POPS INTO SOUTHERN SECTIONS
LATE FRIDAY NIGHT. SINCE WE ARE ON THE EXTREME NRN EDGE..MOST OF THE
PCPN SHOULD FALL AS SNOW...BUT CANT RULE OUT SOME SLEET OR RAIN
MIXING IN. AS THE SFC PATTERN TRANSITIONS TO THE EAST COAST ON
SATURDAY...A H5 S/W SWINGING THRU WILL PROVIDE LIFT AND WILL PULL
PCPN ACROSS THE AREA. A CHANCE OF LIGHT SNOW WILL TRANSITION TO A
RAIN/SNOW MIX DURING THE DAY ON SATURDAY. A CHANCE OF SNOW WILL
LINGER INTO SATURDAY NIGHT AND EARLY SUNDAY.
HIGH PRESSURE WILL BUILD IN FOR THE LAST FEW DAYS OF THE FORECAST
PERIOD.
HIGHS THRU THE PERIOD WILL BE NEAR TO SLIGHTLY BELOW NORMAL. THEY
SHOULD RANGE IN THE 30S FOR THURSDAY. SOUTHERN LOCATIONS MIGHT MAKE
IT INTO THE 40S FRIDAY WHILE THE NORTH REMAINS IN THE 30S. COOLER
AIR WILL WORK BACK IN SATURDAY THRU MONDAY KEEPING HIGHS IN THE 30S.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
AN OCCLUDED FRONT IS PUSHING ACROSS THE REGION THIS MORNING WITH
AN ASSOCIATED BAND OF SHOWERS AND ISOLATED TSTMS VCNTY KLUK 12Z
AND KILN 13Z. THE BACK EDGE OF THIS BAND OF SHOWERS EXTENDS FROM
KCVG TO KDAY AT 12Z AND SHOULD CLEAR ALL THE TERMINALS BY 14Z AS
IT CONTINUE TO MOVE NE. UNSTABLE AIR BEHIND THE FRONT WILL ALLOW
FOR SOME LIGHT VCSH TILL AROUND NOON. A FEW LIGHT SHOWERS ARE
POSSIBLE THROUGH THE REMAINDER OF THE AFTERNOON BUT ARE EXPECTED
TO BE INCONSEQUENTIAL AND HAVE BEEN LEFT OUT OF THE FORECAST.
CYCLONIC FLOW WILL CONTINUE OVER THE AREA THROUGH THE FORECAST
PERIOD MAINTAINING MVFR CIGS.
SFC WINDS ARE EXPECTED TO VEER TO THE WSW AND GUST TO NEAR 25KT BY
LATE MORNING AND CONTINUE WELL INTO THE EVENING.
OUTLOOK...MVFR CEILINGS WILL CONTINUE INTO WEDNESDAY MORNING. MVFR
CEILINGS AND VISIBILITIES POSSIBLE FRIDAY NIGHT INTO SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JGL
NEAR TERM...JGL
SHORT TERM...JGL
LONG TERM...SITES
AVIATION...HAYDU
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
505 AM CST TUE DEC 16 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 216 AM CST TUE DEC 16 2014
MAIN FOCUS IS THE CURRENT PRECIPITATION AND TEMPERATURE TRENDS WITH
THE PASSING SYSTEM. LOOKING AT RADAR LOOPS...THERE ARE ACTUALLY
TWO DISTINCT CIRCULATIONS SHOWN...WITH THE MAIN SWIRL OVER IL...
AND ANOTHER JUST WEST OF GREEN BAY. MAIN DEFORMATION BAND WITH THE
SOUTHERN SWIRL FROM NORTHEAST IA INTO CENTRAL WI. NORTHERN
DEFORMATION BAND FROM SOUTH CENTRAL MN UP INTO THE ARROWHEAD AND
NORTHWEST WI. WARM TEMPERATURES HAVE KEPT PRECIPITATION ALL LIQUID
UP THROUGH 1 AM...BUT A MIX WAS SUGGESTED BY SURFACE OBS AND LAPS
TEMPERATURE FIELDS TO BE JUST MOVING INTO OUR AREA OF SOUTHEAST
MN. THANKFULLY...THE MAIN PUNCH OF THIS COMPLEX STORM SYSTEM IS
ALREADY BEGINNING TO PULL AWAY...SO WITH ONLY LIMITED AMOUNTS OF
PRECIP LEFT TO FALL...DO NOT ANTICIPATE ANY SIGNIFICANT
ACCUMULATION OF SNOW OR ICY MIX. ONLY THREAT FOR AN ACCUMULATION
LOOKS TO BE OVER THE FAR NORTHERN COUNTIES OF OUR SERVICE AREA.
GUSTY NORTHWEST WINDS BEHIND THE FRONT WITH SUSTAINED WINDS IN THE
20-30 MPH RANGE...AND GUSTS UP NEAR 40 MPH. ACCOMPANIED BY FALLING
TEMPS TODAY...EXPECT RAW WIND CHILLS IN THE TEENS TODAY AND SINGLE
DIGITS TONIGHT BEFORE WIND SPEEDS SUBSIDE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 216 AM CST TUE DEC 16 2014
ANOTHER LONG WAVE TROUGH WAS DROPPING QUICKLY SOUTHEAST ACROSS
MANITOBA THIS MORNING...AND THIS WILL END UP MERGING WITH OUR
CURRENT CLOSED CIRCULATION AS THE WHOLE CONGLOMERATION WOBBLES
AROUND THE GREAT LAKES TODAY THROUGH WEDNESDAY. WITH SOME LIFT
GENERATED BY THIS SECOND WAVE...AND WITH CONTINUED COLD AIR
ARRIVING TO HELP SQUEEZE OUT ANY REMAINING MOISTURE FROM THE
BOUNDARY LAYER...ANTICIPATE SOME FLURRIES WILL BE SEEN TONIGHT
GENERALLY NORTH OF I-90...AND INTO WEDNESDAY MAINLY NORTH OF I-94.
HIGH PRESSURE BUILDS INTO THE UPPER MIDWEST FOR THURSDAY...AND
LOOKS TO HANG AROUND ALL THE WAY THROUGH THE WEEKEND. THE UPPER
LEVEL FLOW PATTERN REMAINS VERY BLOCKED ACROSS NORTH AMERICA...
WITH THE MAIN STORM TRACKS WELL SOUTH AND WELL NORTH OF OUR
GENERAL AREA. AS A RESULT...ANTICIPATE BENIGN WEATHER WITH NO
PRECIPITATION AND TEMPERATURES NEAR SEASONAL NORMS.
THE PATTERN DOES APPEAR TO TRANSITION TO MORE ACTIVE ZONAL FLOW AS
WE GET INTO NEXT WEEK...BUT THERE ARE SEVERAL DISCREPANCIES IN THE
VARIOUS MODEL OUTPUTS AS TO WHAT THAT MEANS FOR OUR AREA.
BUT...FOR THE SNOW LOVERS OUT THERE...DO NOT GIVE UP ON A WHITE
CHRISTMAS JUST YET...
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 505 AM CST TUE DEC 16 2014
RADAR AND OBSERVATIONS INDICATE THE BULK OF THE PRECIPITATION HAS
ALREADY MOVED BY BOTH TAF SITES THIS MORNING. STILL A LITTLE BIT
OF WRAP AROUND LIGHT SNOW OVER EASTERN MINNESOTA THAT THE 16.08Z
HRRR SUGGESTS COULD COME ACROSS THIS MORNING AND PRODUCE A PERIOD
OF MVFR VISIBILITIES. OTHERWISE...THE 16.09Z RAP AND 16.06Z NAM
SUGGEST THAT CEILINGS WILL NOT BUDGE TODAY OR TONIGHT IN THE
CYCLONIC FLOW THAT WILL PERSIST BEHIND THE SURFACE LOW. BASED ON
THIS...HAVE KEPT THE CEILINGS AT BOTH SITES MVFR THROUGH THE
ENTIRE PERIOD. THE NORTHWEST WINDS WILL REMAIN GUSTY THROUGH THE
DAY WITH KRST HITTING 30 KNOTS AT TIMES BEFORE THESE WINDS START
TO DIMINISH LATE IN THE AFTERNOON. THE GOOD LOW LEVEL LAPSE RATES
REMAIN IN PLACE INTO THE EVENING...SO HAVE KEPT SOME GUSTS GOING
PAST SUNSET.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...MW
LONG TERM...MW
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
345 AM MST TUE DEC 16 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 330 AM MST TUE DEC 16 2014
CHILLY NIGHT ACROSS THE REGION ESPECIALLY FOR THOSE AREAS IN THE
SOUTHERN NEBRASKA PANHANDLE WHERE SKIES ARE CLEAR AND WIDESPREAD
SNOW IS ON THE GROUND. TEMPERATURES IN THE NORTHERN PANHANDLE ARE
ABOUT 10 DEGREES WARMER DUE TO THE LOW CLOUDS AND PATCHY FOG. ALSO
GETTING FOG IN THE NORTH PLATTE RIVER VALLEY FROM DOUGLAS TO
TORRINGTON WITH REALLY LIGHT WINDS. THE HRRR SUGGESTS THAT THE LOW
CLOUDS WILL BE QUITE PERSISTENT OVER THE PANHANDLE THROUGH LATE
MORNING. GENERALLY QUIET WEATHER OVER THE NEXT FEW DAYS WITH WEAK
SFC PRESSURE GRADIENTS AND A LACK OF IMPACTFUL WEATHER SYSTEMS.
THE MODELS SHOW A SHORTWAVE TROUGH MOVING FROM THE GREAT BASIN
INTO WESTERN WY THIS AFTN INTO TONIGHT. IR IMAGERY CURRENTLY SHOWS
QUITE A BIT OF MIDLVL MOISTURE STREAMING NORTHEASTWARD INTO
COLORADO. THIS MOISTURE WILL PUSH ACROSS THE REGION BY THIS AFTN.
INCREASED POPS A BIT FOR THE SIERRA MADRE AND SNOWY RANGES FOR THE
AFTN...HOWEVER ONLY EXPECTING A FEW INCHES AT MOST. HIGH
TEMPERATURES WILL BE AROUND NORMAL OVER THE NEXT FEW DAYS
(GENERALLY IN THE MID-TO-UPPER 30S)...WHICH MEANS THAT SNOW COVER
FROM THE RECENT STORM WILL BE SLOW TO MELT.
SYNOPTIC PATTERN DOES NOT CHANGE A WHOLE LOT THROUGH THURSDAY.
SIMILAR TO THE LAST FEW WEEKS...THE UPPER LEVEL JET WILL BE REMAIN
ACROSS THE SOUTHWESTERN UNITED STATES WITH WEAK FLOW ALOFT OVER
WY. NO WIND CONCERNS AS THE CAG-CPR GRADIENT NEVER GETS ABOVE 20
METERS. A SFC HIGH OVER THE NORTHERN PLAINS WILL MAINTAIN SOUTH TO
SOUTHEAST WINDS OVER THE NEBRASKA PANHANDLE THROUGH WED NIGHT. THE
NAM AND SREF SHOW THE POTENTIAL FOR LOW CLOUD FORMATION TONIGHT
AND MORE SO ON WED NIGHT. THE MODELS HAVE BEEN CONSISTENT AT
SHOWING MUCH OF THE MOISTURE AND DYNAMICS ASSOCIATED WITH AN UPPER
LEVEL WAVE REMAINING SOUTH OF THE CWA ON WED AND WED NIGHT. KEPT
SLIGHT CHANCE POPS OVER THE SIERRA MADRE AND SNOWY RANGES...WITH
THE BEST CHANCES OF SNOW OVER COLORADO.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 330 AM MST TUE DEC 16 2014
SEASONAL AND A RELATIVELY TRANQUIL PERIOD THROUGH THE UPCOMING
WEEKEND. WARMER AND BREEZY TO LOCALLY WINDY CONDITIONS RETURN
EARLY NEXT WEEK. PERSISTENT NORTHWEST FLOW WILL BE IN PLACE FRIDAY
THRU SUNDAY WITH PERIODIC EMBEDDED SHORTWAVES PASSING OVER THE
REGION. LIGHT MOUNTAIN SNOW WILL BE A POSSIBILITY THRU THE PERIOD
ALONG WITH PERIODIC BOUTS OF CLOUD-COVER ELSEWHERE...THICKEST NEAR
SHORTWAVE ENERGY. SEE LITTLE MOVEMENT IN TEMPERATURES DURING THIS
PERIOD AS WELL AS NORTHWEST FLOW KEEP ADVECTION NEUTRAL. SO HIGHS
IN THE LOW 30S WEST OF THE LARAMIE RANGE AND 30S TO NR 40 EAST CAN
BE EXPECTED.
WINDS WILL STRENGTHEN FOR MONDAY/TUESDAY AS THE NOSE OF 150+ KNOT H3
JET STREAK APPROACHES AND MOVES OVERHEAD. ALTHOUGH TIMING
DIFFERENCES EXIST IN WHEN THE LLVL GRADIENT IS THE STRONGEST...BOTH
ARE SIMILAR IN PROGGING 50-60 KNOTS AT H7 FOR MONDAY AND TUESDAY. IF
SUBSEQUENT MODEL OUTPUT CONTINUES...THIS WOULD BE ENOUGH FOR THE
POSSIBILITY OF THE NEXT HIGH WIND EVENT MAINLY FOR WIND PRONE
AREAS. CHANNELED VORT ENERGY WILL ALSO PROVIDE CHANCES FOR SNOW
SHOWERS MONDAY AND TUESDAY AS WELL. MODELS AGAIN HAVE TIMING
DIFFERENCES DURING THIS PERIOD...SO FOR NOW JUST INTRODUCED SOME
LIGHT SNOW CHANCES DURING THIS PERIOD. DOWNSLOPE COMPONENT WILL
BOOST HIGH TEMPS MONDAY/TUESDAY INTO THE MID/UPPER 30S WEST AND
LOW/MID 40S OUT ON THE ERN PLAINS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY NIGHT)
ISSUED AT 330 AM MST TUE DEC 16 2014
SE WYOMING TERMINALS...VFR CONDITIONS TO PREVAIL AT TERMINALS THIS
MORNING WITH A DRIER AIR MASS OVERHEAD. -SHSN AND MVFR CIGS WILL
RETURN TODAY 18-24Z. WINDS WILL BE SOUTHWEST AT 5 TO 10 KNOTS WITH
LOCALLY HIGHER GUSTS IN THE VICINITY OF KRWL. VFR CONDITIONS RETURN
AFTER 00Z.
WRN NEBRASKA TERMINALS...MAIN CHALLENGE THIS MORNING IS WITH ONGOING
FOG/LOW STRATUS. IFR/LIFR CIGS AND VISIBILITIES WILL CONTINUE AT
MOST WRN NEBRASKA TERMINALS THRU AROUND 18Z...AT WHICH TIME SHOULD
IMPROVE TO MVFR OR EVEN VFR AT KBFF AND KSNY. TIMING OF LIFTING IS
ALWAYS DIFFICULT IN THESE CASES...THOUGH IT LOOKS LIKE KCDR WILL SEE
THE BEST OPPORTUNITY FOR FOG TO HANG IN THE LONGEST TODAY. SHOULD
SEE CONDITIONS SLOWLY IMPROVE BY MIDDAY AND ESPECIALLY DURING THE
AFTERNOON HOURS.
&&
.FIRE WEATHER...
ISSUED AT 330 AM MST TUE DEC 16 2014
NO FIRE WEATHER CONCERNS OVER THE NEXT FEW DAYS. COLD TEMPERATURES
WILL KEEP SNOW COVER ON THE GROUND ACROSS MUCH OF THE REGION.
AFTERNOON HUMIDITY VALUES WILL GENERALLY BE ABOVE 50 PERCENT AND
WINDS WILL BE LIGHT.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...ZF
LONG TERM...CAH
AVIATION...CAH
FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
1100 AM PST Tue Dec 16 2014
.Synopsis...
Periods of valley rain and mountain snow through mid-week as
several weather systems move through the area. Brief drying
expected Thursday, then another system is forecast to bring a
return of showers on Friday.
&&
.Discussion...
Winter Wx Advsry will be allowed to expire at noon as this current
system is winding down. The next system is on our doorstep just off
the coast and will be gradually moving inland tonite. Jet energy
remains off the coast and is digging the trof so Ewd movement of the
system may be a little slower than forecast earlier. The HRRR/WRF
show the couple hour disparity in timing with the HRRR slower.
Will likely issue another WSW and working on the timing details now.
JHM
.Previous Discussion...
The reak in showers we see today will be short-lived as another
system arrives later today and tonight spreading more rain and snow
across NorCal along with bringing gusty southerly winds. That one
exits east by early Wednesday, then another moves in later
Wednesday. Following a break Thursday as short-wave ridging moves
overhead, another system is forecast to move in on Friday.
Total additional QPF through mid-week of 1/3-3/4`s of an inch of
rain can be expected in the valley with 1-2 inches in the
foothills and mountains. Snow levels will be moderately low during
the period generally ranging from 3000-4000 feet. 48 hour snow
accumulations of a foot or more will be possible at the higher
elevations with 4-8 inches possible down to around 4000-5000 feet.
This will lead to travel impacts over the mountains with delays
possible at times with chain requirements.
&&
.Extended Discussion (Saturday through Tuesday)...
The Friday system moves through the area, but showers linger over
mountains on Saturday. The GFS, EC, and GEM depict a 590-591 dm
high center over the eastern Pacific Sunday leaving only slight
chances of precip over the Shasta mountains. The high drifts near
the SoCal coast Monday into Tuesday, drying out the region with
significant southern Sac and northern San Joaquin Valley fog
setting up.
GFS and EC flatten the ridge somewhat Tuesday, and the GEM
actually introduces a trough just offshore. Since all models
trended to at least a flattening/weakening of the ridge, we
introduced a slight potential of light rain over Shasta mountains
Tuesday afternoon. JClapp
&&
.Aviation...
Scattered showers cont this morning with freezing levels ranging
around 3000-3500 ft MSL in Shasta County to 5000-5500 ft MSL near
I-80/hwy 50. IFR cigs at northern valley TAF sites til near 20z
from -SHRA and/or BR. Another system moves in late this afternoon
and/or early evening for continued periods of precip. JClapp
&&
.STO Watches/Warnings/Advisories...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
957 AM PST TUE DEC 16 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE EAST ACROSS SW CA THIS MORNING AND DEVELOP
RAIN SHOWERS AND HIGH ELEVATION SNOW TODAY..WITH A SLIGHT CHANCE
OF THUNDERSTORMS. A SECOND...STRONGER FRONT WILL CREATE MORE
WIDESPREAD SHOWERS TONIGHT THROUGH THURSDAY MORNING...ESPECIALLY
WEDNESDAY MORNING. SNOW LEVELS WILL DROP TO BETWEEN 5000 TO 6000
FEET WEDNESDAY. SEVERAL INCHES OF SNOW ARE EXPECTED ABOVE 6000
FEET. DRY WITH A WARMING TREND THURSDAY AFTERNOON THROUGH FRIDAY.
A WEAK TROUGH MAY PRODUCE ISOLATED LIGHT SHOWERS ON SATURDAY.
WARMER AGAIN WITH DRY OFFSHORE FLOW EARLY NEXT WEEK.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
AT 9 AM PST...WATER VAPOR SATELLITE IMAGERY DISPLAYED A WEAK COLD
FRONT MOVING EAST ACROSS THE SOUTHERN CA BIGHT...AND A TROUGH OFF
OF THE WEST COAST. COMPOSITE RADAR SHOWED LIGHT TO MODERATE
SHOWERS OVER THE COASTAL WATERS...AND OVER PORTIONS OF THE COAST
AND VALLEYS. LIGHT TO MODERATE RAIN AND HIGH ELEVATION MOUNTAIN
SNOW IS FORECAST TODAY ACROSS THE REGION AS THE FRONT MOVES EAST.
MOST UNSTABLE CAPE OF 400-600 J/KG WILL CREATE THE POSSIBILITY OF
ISOLATED THUNDERSTORMS WEST OF THE MOUNTAINS THROUGH THIS EVENING.
A WINTER WEATHER ADVISORY REMAINS IN EFFECT THROUGH THIS EVENING
FOR THE SAN BERNARDINO COUNTY MOUNTAINS ABOVE 6000 FT.
...PRECIPITATION ACCUMULATIONS TODAY...
DESERTS.........ONE-TENTH TO ONE-QUARTER IN
COAST/VALLEYS...ONE-QUARTER TO ONE-HALF IN
MOUNTAINS.......ONE-HALF TO THREE-QUARTERS IN
...SNOWFALL ACCUMULATIONS TODAY...
SAN BERNARDINO COUNTY MOUNTAINS ABOVE 6000 FT...1 TO 3 IN
RIVERSIDE COUNTY MOUNTAINS ABOVE 7000 FT......1 TO 2 IN
A SECOND...STRONGER FRONT...WILL MOVE ACROSS THE AREA TONIGHT
THROUGH THURSDAY MORNING...AND GENERATE MORE WIDESPREAD SHOWERS
AND MOUNTAIN SNOW...ESPECIALLY WEDNESDAY MORNING. ISOLATED
THUNDERSTORMS WILL BE POSSIBLE AGAIN AS ELEVATED INSTABILITY
REDEVELOPS OVER SW CA. BREEZY WEST TO SOUTHWEST WINDS WILL ALSO
DEVELOP OVER MOUNTAIN RIDGES AND THROUGH PASSES WEDNESDAY AS THE
FRONT PASSES...WITH GUSTS TO 45 MPH POSSIBLE.
...PRECIPITATION ACCUMULATIONS TONIGHT THROUGH THU AM...
DESERTS.....ONE-QUARTER TO ONE-HALF IN
COAST.......ONE-HALF TO ONE IN
VALLEYS.....THREE-QUARTERS TO ONE AND ONE-HALF IN
MOUNTAINS...ONE TO TWO IN
...SNOWFALL ACCUMULATIONS TONIGHT THROUGH THU AM FOR SAN BERNARDINO...
RIVERSIDE AND SAN DIEGO COUNTY MOUNTAINS...
5000-6500 FT...TRACE TO 4 IN
6500-8000 FT...4 TO 8 IN...WITH LOCALLY HIGHER AMOUNTS ABOVE 8000 FT
SEE LAXWSWSGX FOR DETAILS ON THE WINTER WEATHER ADVISORIES AND
WINTER STORM WATCH CURRENTLY IN EFFECT. MODERATE TO HEAVY
RAINFALL IN SHOWERS WILL CREATE THE POSSIBILITY OF FLASH FLOODING
AND DEBRIS FLOW OVER RECENT BURN SCARS...ESPECIALLY THE SILVERADO
AND MOUNTAIN SCARS. A FLASH FLOOD WATCH REMAINS IN EFFECT FOR
THOSE AREAS FROM THIS AFTERNOON THROUGH WEDNESDAY AFTERNOON. HIGHS
5 TO 10 DEGREES BELOW NORMAL WILL CONTINUE ACROSS THE REGION
THROUGH THURSDAY.
WEAK UPPER-LEVEL HIGH PRESSURE WILL BUILD OVER THE AREA LATE
THURSDAY AND FRIDAY...KEEPING THE WEATHER DRY AND RAISING HIGHS TO
ONLY AROUND 5 DEGREES F ABOVE NORMAL. A SHORT-WAVE TROUGH WILL
QUICKLY SWING ACROSS THE AREA SATURDAY MORNING. A SLIGHT CHANCE OF
SHOWERS IS FORECAST. HOWEVER...PRECIPITABLE WATER OF AROUND THREE-
QUARTERS INCH AND WEAK INSTABILITY ALOFT WILL LIMIT MUCH SHOWER
DEVELOPMENT. HIGH PRESSURE WILL THEN REBUILD OFF THE WEST COAST
EARLY NEXT WEEK...WHICH WILL SLOWLY INCREASE HIGH TEMPERATURES TO
AROUND 10 DEGREES F ABOVE NORMAL BY NEXT TUESDAY...WITH WEAK
OFFSHORE FLOW DEVELOPING AND A MORE SHALLOW MARINE LAYER.
&&
.AVIATION...
161644Z...MULTIPLE BKN-OVC CLOUD DECKS IN THE 2500-10000 FT MSL
LAYER WITH INCREASING SHOWERS...LOCAL VIS AOB 2SM IN RA/+RA...AND
MOUNTAIN OBSCURATION ABOVE 2500 FT MSL THROUGH 17/0900 UTC MAINLY
OVER AND WEST OF THE MOUNTAINS. ISOL THUNDERSTORMS POSSIBLE STARTING
1800 UTC...WITH CB TOPS TO 30000 FT MSL...SMALL HAIL...HEAVY
RAIN...LOCAL VIS BELOW 1 SM...AND GUSTY DOWNDRAFT WINDS POSSIBLE.
DESERTS WILL HAVE MOSTLY UNRESTRICTED VIS AND BKN-OVC CLOUDS AOA
12000 FT MSL. 17/0900-1800 UTC...SHOWERS INCREASING SIGNIFICANTLY IN
COVERAGE AND INTENSITY...MAINLY OVER AND WEST OF THE MOUNTAINS AND
OVER THE HIGH DESERTS...WITH BKN-OVC CLOUDS IN THE 1500-15000 FT MSL
LAYER...AREAS OF 2-5 SM VIS...LOCAL VIS 1 SM OR LESS...MOUNTAIN
OBSCURATION ABOVE 1500 FT MSL...AND POSSIBLE THUNDERSTORMS. COASTAL
TAF SITES LIKELY TO GET HEAVIEST RAIN AND LOWEST VIS/CIGS IN THE
17/1100-1600 UTC TIME-FRAME. LOWER DESERTS LIKELY TO GET SOME
SHOWERS AFTER 17/1200 UTC WITH LOCAL CIGS/VIS 2500 FT AGL/5 SM.
OTHERWISE...LOWER DESERTS WILL HAVE BKN-OVC CLOUDS IN THE 7000-13000
FT MSL LAYER.
&&
.MARINE...
933 AM...SOUTHERLY WINDS HAVE PICKED UP AT THE SAN CLEMENTE BASIN
BUOY OVER THE PAST SEVERAL HOURS...WHICH THE HRRR MODEL SEEM TO PICK
UP ON BETTER THAN THE OTHER HIGH-RES MODELS. THUS...THE COASTAL
WATERS FORECAST WAS UPDATED AT 8 AM TO REFLECT THE STRONGER WINDS
TODAY AS A WEAK COLD FRONT MOVES THROUGH. A MUCH STRONGER FRONT
ARRIVES EARLY WEDNESDAY MORNING WITH STRONG SOUTHWEST WINDS TURNING
NORTHWEST BY LATE WEDNESDAY MORNING. ALSO...SEAS FROM THE EXPECTED
WEST-NORTHWEST SWELL HAVE JUMPED UP TO NEAR 10 FEET FINALLY. THE
SWELL WILL PEAK TODAY...WITH COMBINED SEAS NEAR OR ABOVE 10 FEET
THROUGH WEDNESDAY MORNING...BEFORE LOWERING DURING THE REST OF
WEDNESDAY. SEE THE SMALL CRAFT ADVISORY FOR DETAILS...LAXMWWSGX.
THESE COLD FRONTS WILL ALSO BRING INCREASED INSTABILITY...STARTING
THIS MORNING AND CONTINUING THROUGH WEDNESDAY AFTERNOON...WITH
THUNDERSTORMS MOST LIKELY TO OCCUR WEDNESDAY MORNING. THESE
THUNDERSTORMS ARE CAPABLE OF PRODUCING WATERSPOUTS AND STRONG GUSTY
WINDS. SEE THE MARINE WEATHER STATEMENT FOR DETAILS...LAXMWSSGX.
&&
.BEACHES...
844 AM...LATEST OBSERVATIONS AT THE SAN CLEMENTE BASIN BUOY SHOWED
THE SWELL JUMPING UP TO 10 FEET AT 17 SECONDS...WITH NEARSHORE BUOYS
HAVING JUMPED TO 4 TO 6 FEET. DUE TO THE LOWER SWELL HEIGHTS THAN
CURRENTLY FORECAST BY THE WAVE WATCH 3...SURF HEIGHTS MAY BE A
LITTLE LOWER THAN PREVIOUSLY FORECAST...POSSIBLY AROUND 5 TO 8 FEET
WITH LOCAL 10 FOOT SETS. HOWEVER...IF THE LATEST BUOY OBSERVATIONS
ARE ANY INDICATION...THE SWELL MAY JUST BE LATE TO ARRIVE AND SURF
OF 6 TO 10 FEET AND LOCAL 12 FOOT SETS COULD STILL OCCUR. THE LARGE
WEST-NORTHWEST SWELL WILL PEAK TODAY AND BRING HIGH SURF AND STRONG
RIP CURRENTS TO AREA BEACHES. THE SURF WILL SLOWLY SUBSIDE LATE
TONIGHT THROUGH WEDNESDAY. A HIGH SURF ADVISORY REMAINS IN EFFECT
THROUGH WEDNESDAY MORNING. SEE THE HIGH SURF ADVISORY FOR THE SURF
DETAILS...LAXCFWSGX.
&&
.SKYWARN...
SKYWARN ACTIVATION MAY BE REQUESTED THIS AFTERNOON THROUGH
WEDNESDAY DUE TO POTENTIALLY HEAVY RAIN AND ISOLATED THUNDERSTORMS.
WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS TO THE NATIONAL WEATHER SERVICE.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...HIGH SURF ADVISORY UNTIL NOON PST WEDNESDAY FOR THE BEACHES
IN THE ORANGE COUNTY COASTAL AREAS...SAN DIEGO COUNTY COASTAL
AREAS.
WINTER WEATHER ADVISORY UNTIL 6 PM PST THIS EVENING ABOVE 6000
FEET FOR THE SAN BERNARDINO COUNTY MOUNTAINS.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY AFTERNOON
ABOVE 5500 FEET FOR THE SAN BERNARDINO COUNTY MOUNTAINS.
FLASH FLOOD WATCH FROM NOON PST TODAY THROUGH WEDNESDAY
AFTERNOON FOR THE RIVERSIDE COUNTY MOUNTAINS...SANTA ANA
MOUNTAINS AND FOOTHILLS.
WINTER WEATHER ADVISORY FROM 6 AM TO 8 PM PST WEDNESDAY FOR THE
RIVERSIDE COUNTY MOUNTAINS...SAN DIEGO COUNTY MOUNTAINS.
PZ...SMALL CRAFT ADVISORY UNTIL 10 PM PST WEDNESDAY FOR THE BEACHES
IN THE COASTAL WATERS FROM SAN MATEO POINT TO THE MEXICAN
BORDER AND OUT 30 NM...WATERS FROM SAN MATEO POINT TO THE
MEXICAN BORDER EXTENDING 30 TO 60 NM OUT INCLUDING SAN
CLEMENTE ISLAND.
&&
$$
PUBLIC...JJT
AVIATION/MARINE/BEACHES...HARRISON
RADAR...PG
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1228 PM EST TUE DEC 16 2014
.PREV DISCUSSION... /ISSUED 300 AM EST TUE DEC 16 2014/
SHORT TERM /TODAY THROUGH WEDNESDAY/...
ONGOING OVERNIGHT RAIN SHOWERS ACROSS THE AREA WILL CONTINUE THROUGH
LATE MORNING AND EARLY AFTERNOON ACROSS THE CWA AS FRONT PUSHES INTO
THE STATE. INSTABILITY CONTINUES TO BE LIMITED...AND ALTHOUGH
PORTIONS THERE IS A HISTORY OF SOME SMALL AMOUNTS OF MUCAPE AND
LIGHTNING OVER ALABAMA...THUS FAR HAVE NOT HAD ANY LIGHTNING IN THIS
ACTIVITY. AT BEST EXPECT WIDESPREAD 0.25 INCHES OF ADDITIONAL
RAINFALL...WITH HIGHEST AMOUNTS ACROSS NORTHEAST GEORGIA AS THE AREA
OF RAIN TRANSITIONS FARTHER EAST.
ALTHOUGH HRRR PUSHES RAIN SOUTH AND EAST OF THE CWA BY NOON...A FEW
OF THE SHORT TERM HI-RES MODELS CONTINUE TO ADVERTISE RESIDUAL
MOISTURE ACROSS THE AREA...PARTICULARLY FAR NORTH GEORGIA...SO HAVE
KEPT MENTION OF SLIGHT CHANCE POPS UNTIL 21-22Z.
THE PARENT LOW PRESSURE SYSTEM LIFTS OVER THE EASTERN GREAT LAKES
REGION LATE TONIGHT WITH ZONAL FLOW ALOFT RETURNING TO THE REGION
THROUGH THURSDAY MORNING.
HAVE GENERALLY GONE WITH A BLEND FOR TEMPERATURES...WITH NEAR
SEASONAL TEMPERATURES THROUGH THE SHORT TERM.
31
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
BETTER AGREEMENT FOR THE WEEKEND SYSTEM AMONGST THE LONG TERM
MODELS.
SHORT WAVE STILL ON TRACK FOR OVERNIGHT WEDNESDAY INTO THURSDAY
MORNING. ANY PRECIP CHANCES WITH THIS SYSTEM SHOULD BE ON
THURSDAY...WITH ONLY SOME SCATTERED SPRINKLES IN THE NORTHWEST
OVERNIGHT WEDNESDAY. WEDNESDAY MIN TEMPS SHOULD BE WARM ENOUGH NOT
TO CAUSE ANY PTYPE ISSUES EARLY THURSDAY MORNING.
THE NEXT SYSTEM TO IMPACT THE CWFA IS IN THE FRIDAY THROUGH
SATURDAY TIME FRAME. MODELS HAVE COME INTO BETTER AGREEMENT WITH
THE EVOLUTION OF THIS SYSTEM AS COMPARED TO YESTERDAYS RUNS AT
THIS TIME. THE ECMWF HAS A WEAKER 500MB SYSTEM AND THE GFS HAS
NUDGED ITS SURFACE LOW FURTHER SOUTH. ISENTROPICALLY INDUCED
RAINFALL SHOULD BEGIN DURING THE DAY FRIDAY AND SPREAD NORTHEAST
THROUGH THE DAY. CURRENTLY...THE HIGHEST CHANCES FOR PRECIP WILL
BE FRIDAY NIGHT INTO SATURDAY AS LOW PRESSURE TRAVERSES THE AREA.
THE RAIN CHANCES WILL BEGIN TO TAPER OFF EARLY SATURDAY
EVENING. AS FAR AS THE RASN CHANCES FOR THE HIGHER TERRAIN LATE
SATURDAY/EARLY SUNDAY...THE POTENTIAL IS STILL THERE.
HOWEVER...CHANCES STILL REMAIN SMALL. TEMPS IN THE MODELS ARE
WARMER BY A FEW DEGREES AND THE MODELS CAN BE TOO SLOW TO CUT OFF
PRECIP BEHIND A COLD FRONT/LOW PRESSURE. WILL CONTINUE WITH
PERSISTENCE AND KEEP MENTION IN THE FORECAST.
HIGH PRESSURE BRIEFLY BUILDS INTO THE CWFA FOR MONDAY INTO EARLY
TUESDAY WITH THE NEXT SYSTEM IMPACTING THE CWFA TUESDAY NIGHT INTO
WEDNESDAY.
NLISTEMAA
&&
.AVIATION...
18Z UPDATE...
MAINLY VFR THROUGH THE PERIOD. SOME LINGERING MVFR CIGS NEAR
MCN/AHN BUT RAPID IMPROVEMENT EXPECTED. METRO TAFS MAY SEE SOME
SCT TO POSSIBLY BKN MVFR WEDNESDAY MORNING...BUT CURRENT THINKING
IS CIGS SHOULD GENERALLY STAY NORTH OF METRO TAFS. W TO NW WINDS
THROUGH THE PERIOD AROUND 10KT AND GUSTY THIS AFTERNOON...DROPPING
BELOW 10KT OVERNIGHT.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM-HIGH ON NO CIGS WEDNESDAY MORNING.
HIGH ON ALL OTHER ELEMENTS.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 60 36 56 37 / 60 0 0 5
ATLANTA 61 38 55 38 / 40 0 0 5
BLAIRSVILLE 55 34 52 32 / 20 0 0 5
CARTERSVILLE 58 35 53 35 / 10 0 0 5
COLUMBUS 66 37 58 38 / 40 0 0 5
GAINESVILLE 56 36 54 37 / 40 0 0 5
MACON 69 36 60 36 / 30 0 0 5
ROME 57 35 53 35 / 10 0 0 5
PEACHTREE CITY 62 34 56 35 / 50 0 0 5
VIDALIA 69 42 62 39 / 20 0 0 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
314 PM CST TUE DEC 16 2014
.SHORT TERM...
313 PM CST
TONIGHT THROUGH FRIDAY...
FILLING SURFACE LOW WAS OFF TO OUR EAST ACROSS THE CENTRAL GREAT
LAKES THIS AFTERNOON...BENEATH WEAKENING UPPER LEVEL LOW WHICH IS IN
THE PROCESS OF MERGING WITH STRONG DIGGING SHORT WAVE OVER THE UPPER
MISSISSIPPI VALLEY. THIS SECOND WAVE IS PROGGED TO SHEAR SOUTHEAST
ACROSS THE REGION TO THE EAST-SOUTHEAST AS IT REDEVELOPS INTO
REMNANT UPPER TROUGH TO THE EAST. VISIBLE SATELLITE IMAGERY SHOWS
MOST OF THE DEEPER CLOUD COVER HAS MOVED OFF TO THE EAST OF THE
FORECAST AREA...ALONG WITH THE BRUNT OF THE RADAR DETECTABLE
PRECIPITATION. EXPECT SOME PATCHY LIGHT RAIN/DRIZZLE AND PERHAPS A
FEW WET FLURRIES TO GRADUALLY END ACROSS THE AREA OVER THE NEXT FEW
HOURS AS MID-LEVELS CONTINUE TO DRY OUT...WITH 12Z RAOBS FROM
UPSTREAM LOCATIONS SUCH AS ABR AND OAX INDICATIVE OF MUCH DRIER AIR
ABOVE THE BOUNDARY LAYER. OTHERWISE...BLUSTERY WEST-NORTHWEST WINDS
WILL CONTINUE TO PULL COLDER AND DRIER AIR INTO THE AREA TONIGHT
WITH WINDS SLOW TO DIMINISH DUE TO LINGERING SURFACE TROUGHING
ACROSS THE UPPER MIDWEST. THOUGH REMAINING MOISTURE WILL BE SHALLOW
IT APPEARS CLOUD COVER WILL LINGER AT LEAST INTO EARLY WEDNESDAY
BEFORE STRONGER SUBSIDENCE CAN ERODE AND SCATTER CLOUDS MORE
EFFECTIVELY. DESPITE CLOUDS...UPSTREAM TEMPS ACROSS EASTERN IA ARE
ONLY IN THE LOW TO MID 20S AT THIS HOUR...SETTING THE STAGE FOR
CHILLIER TEMPS TONIGHT.
SHEARED MID-LEVEL VORTICITY AXIS FROM SHEARING UPPER MIDWEST SHORT
WAVE REMAINS OVER AREA WEDNESDAY..THOUGH HEIGHT RISES DO DEVELOP AS
THE NEW UPPER LOW DEEPENS OVER NEW ENGLAND. THIS ALLOWS THE GRADIENT
TO WEAKEN MORE QUICKLY ESPECIALLY DURING THE AFTERNOON AND
CONTINUING WEDNESDAY NIGHT AS SURFACE HIGH PRESSURE RIDGE MOVES
SLOWLY INTO WESTERN AND CENTRAL ILLINOIS. GUIDANCE DOES DEPICT A
SHORT WAVE APPROACHING FROM THE SOUTHERN PLAINS/LOWER MISSOURI
VALLEY AREA WEDNESDAY NIGHT...THOUGH THIS WAVE DAMPENS SIGNIFICANTLY
AS IT MOVES INTO THE UPPER RIDGE ACROSS THE MIDWEST. MODEL FORECAST
SOUNDINGS AND TIME-HEIGHT PLOTS INDICATE INCREASING MID-HIGH LEVEL
MOISTURE MAINLY AFTER MIDNIGHT WEDNESDAY NIGHT ACROSS OUR SOUTHWEST.
GUIDANCE (NAM...GFS...ECMWF AND SREF) DOES PRODUCE SOME LIGHT QPF
ACROSS CENTRAL ILLINOIS THURSDAY AS THIS WAVE CONTINUES TO
DEAMPLIFY...THOUGH FORECAST SOUNDINGS INDICATE LOW LEVELS INITIALLY
DRY AND SATURATION APPEARS INCOMPLETE MAKING PRECIP AT THE SURFACE A
LOW PROBABILITY. WEAKENING SURFACE HIGH PRESSURE RIDGE EVENTUALLY
MOVES INTO THE AREA THURSDAY NIGHT AND FRIDAY...ROUNDING OUT A FEW
DAYS OF MAINLY DRY AND SEASONABLY COOLER DAYS.
RATZER
&&
.LONG TERM...
313 PM CST
SATURDAY THROUGH TUESDAY...
ATTENTION TURNS TO A PAIR OF APPROACHING SHORT WAVE TROUGHS IN A
SOMEWHAT SPLIT FLOW REGIME. GUIDANCE HAS TRENDED WEAKER WITH THE
SOUTHERN STREAM DISTURBANCE...WHICH MOVES OUT ACROSS THE SOUTHERN
PLAINS AND GULF COAST STATES THROUGH SATURDAY. DECENT AGREEMENT IN
MODEL SOLUTIONS OF A MORE DIGGING NORTHERN STREAM WAVE COMING OUT OF
THE NORTHERN ROCKIES FRIDAY AND MOVING INTO THE LOWER MISSOURI AND
LOWER OHIO VALLEYS ON SATURDAY. WHILE MAIN SURFACE LOW PRESSURE
DEVELOPS WITH SOUTHERN SYSTEM ALONG THE GULF COAST...NORTHERN STREAM
FORCING DOES INDUCE AN INVERTED TROUGH INTO THE OHIO VALLEY SATURDAY
WHICH CONTINUES TO SUPPORT THE POTENTIAL FOR SOME LIGHT SNOW FROM
SOUTHERN/CENTRAL ILLINOIS INTO NORTHERN INDIANA...POSSIBLY INCLUDING
THE SOUTHEASTERN PART OF OUR CWA AS THE UPPER TROUGH MOVES OVERHEAD.
GUIDANCE STILL FOCUSES GREATER QPF SOUTHEAST OF THE FORECAST AREA...
BUT PRUDENT TO MAINTAIN SLIGHT CHANCES FOR SOME LIGHT ACCUMULATING
SNOW SOUTHEAST OF ABOUT A PONTIAC-VALPARAISO LINE. SURFACE HIGH
PRESSURE RIDGING QUICKLY BUILDS IN BEHIND THIS SYSTEM SATURDAY NIGHT
INTO SUNDAY. TEMPS DO MODERATE TO NORMAL FOR THE WEEKEND...GENERALLY
MID 20S AT NIGHT TO LOW/MID 30S BY DAY.
12Z GFS AND ECMWF RUNS HAVE COME INTO GOOD AGREEMENT IN BRINGING A
MORE AMPLIFIED UPPER TROUGH INTO THE CENTRAL CONUS SUNDAY NIGHT
THROUGH TUESDAY...WITH A STRONGER EMBEDDED SHORT WAVE MOVING ACROSS
THE UPPER MIDWEST LATE MONDAY-TUESDAY WITH DEEPENING LOW PRESSURE
PASSING TO OUR NORTH. THIS RESULTS IN WARMING TEMPERATURES ON
STRENGTHENING SOUTH WINDS...WITH THE POTENTIAL OF RAIN/SNOW CHANGING
TO RAIN BY LATE MONDAY AND CONTINUING TUESDAY AHEAD OF THE
APPROACHING COLD FRONT AS THE LOW MOVES ACROSS THE NORTHERN LAKES.
SOME DETAIL AND SPEED DIFFERENCES DO EXIST BETWEEN MODELS AND MUCH
COULD CHANGE BETWEEN NOW AND MONDAY...THOUGH IT DOES APPEAR THAT
COLDER AIR WOULD SPREAD INTO THE REGION LATER TUESDAY/TUESDAY NIGHT
WITH PRECIPITATION TAPERING OFF AS IT MIXES/CHANGES TO LIGHT SNOW.
COLDER AIR WOULD THEN ARRIVE IN TIME FOR THE CHRISTMAS HOLIDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* MVFR CEILINGS THROUGH MUCH OF THE FORECAST PERIOD.
* LINGERING SHOWERS EXITING THIS AFTERNOON.
* STRONG WEST/NORTHWEST WINDS THIS AFTERNOON.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
SURFACE LOW AND FRONTAL BOUNDARY CONTINUE TO PUSH THROUGH THE
REGION EARLY THIS AFTERNOON...WITH CEILINGS AND SHOWERS STILL
LINGERING ACROSS THE TERMINALS AND WHILE WEST NORTHWEST WINDS
BEGIN TO INCREASE. EXPECT ANY LINGERING PRECIP TO EXIT OVER THE
NEXT SEVERAL HOURS WHILE CURRENT LOW END MVFR CEILINGS OBSERVE A
SLOW RISING TREND THIS AFTERNOON. DID KEEP MVFR CEILINGS IN
THROUGH TOMORROW AS A FAIR AMOUNT OF STRATUS DOES REMAIN UPSTREAM.
THE CURRENT HOLES DEVELOPING ON THE WESTERN EDGE COULD BE A
PREVAILING FEATURE ON WEDNESDAY...POSSIBLY REACHING THE TERMINALS
WEDNESDAY AFTERNOON. POST FRONTAL WEST NORTHWEST WINDS ARE
INCREASING EARLY THIS AFTERNOON AND EXPECT THIS INCREASE TO
CONTINUE...WITH GUSTS LIKELY PERSISTING OVERNIGHT INTO WEDNESDAY
MORNING.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE WITH MVFR CEILINGS TODAY AND TONIGHT...MEDIUM
CONFIDENCE OF DURATION ON WEDNESDAY.
* HIGH CONFIDENCE WITH SHOWER TRENDS.
* HIGH CONFIDENCE WITH WIND SPEED/DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT THROUGH MONDAY...DRY/VFR.
&&
.MARINE...
130 PM CST
LOW PRESSURE AND A COLD FRONT HAVE PASSES EAST OF LAKE MICHIGAN AND
WINDS HAVE SHIFTED NORTHWESTERLY. STRONG COLD ADVECTION AND STRONG
PRESSURE RISES AS THE LOW PULLS AWAY TO THE EAST AND HIGH PRESSURE
BUILDS ACROSS THE NORTHERN PLAINS WILL COMBINE TO DRIVE WINDS TO
30KT FOR THE REMAINDER OF THE AFTERNOON THROUGH TONIGHT AND MUCH OF
TOMORROW. THERE IS THE POTENTIAL FOR A FEW GALE FORCE GUSTS...BUT
IN GENERAL...DO NOT EXPECT ENOUGH PREVAILING GALE FORCE WINDS TO
NECESSITATE A GALE WARNING. HOWEVER...A SMALL CRAFT ADVISORY HAS
ALREADY BEEN ISSUED FOR THE NEARSHORE WATERS AND EXPECT THAT TO PLAY
OUT AS CURRENTLY ADVERTISED. THE OVERALL PATTERN WILL BE SLOWLY
PROGRESSIVE...SO BRISK WINDS WILL REMAIN OVER THE LAKE THROUGH
THURSDAY...BUT AS HIGH PRESSURE BEGINS TO BUILD ACROSS THE WESTERN
GREAT LAKES...WINDS SHOULD DROP OFF AND BECOME MORE VARIABLE IN
DIRECTION. HIGH PRESSURE WILL PREVAIL ACROSS THE GREAT LAKES FROM
LATE THURSDAY THROUGH THE WEEKEND...KEEPING WINDS RELATIVELY LIGHT
IN SPEED AND VARIABLE IN DIRECTION. BY EARLY NEXT WEEK...THE HIGH
SHOULD FINALLY PUSH EAST OF LAKE MICHIGAN AS LOW PRESSURE BEGINS TO
DEVELOP OVER THE NORTHERN PLAINS. THIS SHOULD SET UP A PERIOD OF
INCREASING SOUTHERLY WINDS FOR EARLY NEXT WEEK AS A LOW PRESSURE
SYSTEM DEEPENS WHILE CROSSING THE NORTHERN PLAINS AND DRAGGING A
TRAILING COLD FRONT ACROSS THE CENTRAL PLAINS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 AM
WEDNESDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 10 AM THURSDAY.
&&
$$
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
240 PM CST Tue Dec 16 2014
.SHORT TERM...(Tonight)
ISSUED AT 230 PM CST TUE DEC 16 2014
Occluded low pressure system shifts into the eastern Great Lakes
this evening, allowing the gradient to gradually relax and decrease
wind gusts. Latest NAM forecast soundings and HRRR ceiling guidance
suggest lower clouds will persist overnight, and given deep cyclonic
flow and in-building subsidence inversion at 900 MB, believe this
will hold true. Therefore have increased cloud cover overnight.
Lows will be challenging with the full effect of CAA being offset by
insulating effects of cloud cover. Have trended mins 2-3 degrees
warmer than MET/MAV blend, which gives lower 20s west of the IL
River, to mid 20s central/east.
&&
.LONG TERM...(Wednesday through Tuesday)
ISSUED AT 230 PM CST TUE DEC 16 2014
High pressure to settle into the region on Wednesday bringing in dry
with more seasonal temperatures. Forecast soundings...although not
as aggressive as yesterday with the low level moisture...continues
to indicate moisture trapped beneath a subsidence inversion will
keep a bit more cloudiness around the area during the day. Soundings
do show some breaks developing by late morning into the afternoon
hours but just in time to see mid and high level moisture/clouds
stream in ahead of our next weather system for Thursday. That weather
system is expected to spread light snow into parts of extreme west
central through southeast Illinois Thursday morning. Model runs had
been suggesting as the precip spread northeast into a more confluent
flow pattern over the lower Great Lakes coverage would decrease
during the day Thursday. Most of the operational models have backed
off that idea for now and have brought some light precip further north
and east into our area on Thursday so have brought precip chances further
north into the forecast area. Snowfall could accumulate up to 1 inch
from Springfield south Thursday morning before the area begins to
decrease in coverage during the afternoon.
Thursday`s system should be off to our east by evening with our attention
turning to a more significant wave over eastern Texas that will push
a surface low east-northeast across the Gulf Coast states Friday. The
northern periphery of the precip associated with the southern wave will
track over southeast Illinois with once again light snowfall for later
Friday night into Saturday. Current indications suggest an inch or less
for southeast Illinois. High pressure will then shift east into our
area for Sunday into early Monday bringing quiet weather to the region.
Quite a bit of model spread with respect to the system for early next
week, which will be moving southeast out of the Northern Plains and
tracking a strong low pressure system at the surface to our north
Monday. The operational GFS is more progressive with the early week
system and sweeps the cold front thru our area Tuesday afternoon and
evening with little if any southern stream interaction showing up
on the latest model run. In contrast, the latest ECMWF was indicating
a more phased look between the northern and southern streams which
effectively holds up the front pushing across our area later Tuesday
until a surface wave shifts off to our northeast Tuesday night.
This would bring rain on Tuesday, which would eventually change to
snow later in the day and evening as the deepening surface wave shifts
away from our area by Wednesday.
Seems as if each model run has a different solution with respect to
the pattern over the Midwest the first half of next week so not making
any significant changes to the grids at this point for days 7 and 8.
After our brief warm up ahead of the system on Monday and Tuesday, it
turns colder again by midweek.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1138 AM CST TUE DEC 16 2014
Remnant showers and drizzle with visibility reductions to 2-4 SM will
exit the eastern TAF sites by 20Z. Ceilings have already risen to
MVFR levels at PIA/SPI, and this trend will continue to the east
this afternoon, as low pressure shifts farther away from the
region. Main concern for this forecast is possibility/extent of
scattering out MVFR ceilings tonight into tomorrow morning.
Forecast soundings from higher resolution models point to a
familiar scene from the past few weeks, with a strong subsidence
inversion trapping moisture around 1500 FT. This looks likely to
keep ceilings in place at least through 15Z/Wed, even with
northwest winds bringing in drier air at the surface. Tight
pressure gradient will keep west winds gusting at 25 kts this
afternoon. Gusts will diminish after sunset with speeds tapering
to around 10 kts as the gradient relaxes, and under 10 kts towards
sunrise as surface ridge builds in from the NW.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...25
LONG TERM...Smith
AVIATION...25
AREA FORECAST DISCUSSION
NWS DES MOINES IA
330 PM CST TUE DEC 16 2014
.SHORT TERM /TONIGHT/...
ISSUED AT 330 PM CST TUE DEC 16 2014
MAIN CHALLENGES TONIGHT WILL BE CLOUD COVER AND TEMPERATURES.
BRIEF BREAK IN CLOUDS THIS AFTERNOON WEST AS NOSE OF COLD AIR
ADVECTION MOVED SOUTHEAST ACROSS THE REGION. AS THE LOWEST
PORTIONS OF THE BOUNDARY LAYER WARMED...CLOUDS AGAIN FORMED ON THE
TOPS OF THE THERMALS...THEN BACKFILLING TO SOME EXTENT ACROSS THE
REGION. TONIGHT...MAY SEE THE CLOUDS DISSIPATE BRIEFLY AS THE
PROCESS REVERSES WITH SUNSET AND AN AREA OF CLEARING MAY DEVELOP
ONCE AGAIN WEST/CENTRAL. CONFIDENCE ON HOW LONG OR HOW WIDESPREAD
ANY CLEARING WILL BE IS LOW...GIVEN THE TENDENCY FOR MORE STRATUS
TO REDEVELOP AS THE RIDGE WEST OF THE AREA BEGINS TO MOVE EAST
OVERNIGHT. THE OTHER FACTOR REGARDING CLOUD COVER IS A WEAK WAVE
OVER COLORADO THIS AFTERNOON...WHICH IS CAUSING A RETURN OF WARM
AIR ADVECTION OVER THE WESTERN PLAINS. THIS IS GENERATING AN AREA
OF MID LEVEL CLOUDS WHICH SHOULD BEGIN ADVECTING EAST OVER THE
H700 RIDGE TOWARD IOWA OVERNIGHT. CONSEQUENTLY...OVERNIGHT WILL
MOST LIKELY SEE A MIXTURE OF SOME CLEARING EARLY AND CLOUDS MOST
AREAS LATE INTO SUNRISE. WINDS ALOFT WILL CONTINUE TO DECOUPLE BY
EVENING AND LIGHTER NORTHWEST WINDS ARE EXPECTED TONIGHT.
TEMPERATURES WILL BE QUITE CHILLY...AND REGARDLESS OF THE CLOUD
COVER...THE PERSISTENT LOW LEVEL COLD AIR ADVECTION TODAY WILL
RESULT IN OVERNIGHT LOWS NEAR 5 FAR NORTHWEST TO NEAR 20 IN THE
SOUTH. FETCH OF COLD AIR SUGGESTS THE WEST/NORTHWEST WILL BE
COLDER DUE TO ADVECTION TODAY.
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
ISSUED AT 330 PM CST TUE DEC 16 2014
A PROGRESSIVE BUT RELATIVELY CALM WEATHER PATTERN WILL BE IN
PLACE OVER THE REGION THROUGH THE WEEKEND WITH WITH TWO MAIN
WEATHER SYSTEMS OF NOTE ON THURSDAY AND EARLY NEXT WEEK. THE
BEGINNING OF THE PERIOD WILL SEE AN INVERTED 500 MB TROUGH AND
ASSOCIATED PV ANOMALY SWING THROUGH THE UPPER MISSISSIPPI RIVER
VALLEY ON THE BACKSIDE OF A DEPARTING LOW. A SURFACE RIDGE AXIS
WILL ALSO LAY OUT ACROSS THE WESTERN PORTION OF THE STATE ON
WEDNESDAY WITH LIGHT NORTHERLY FLOW OVER THE CWA. THE BIGGEST
QUESTION FOR TOMORROW WILL BE THE EXTENT AND DURATION OF CLOUD
COVER. NAM 0.5-1 KM MOISTURE PROFILES KEEP STRATUS OVER THE
NORTHEAST THROUGH MUCH OF THE DAY TOMORROW AND LEANED TOWARDS THIS
GUIDANCE FOR SKY GRIDS...BUT GIVEN THE UNCERTAINTY IN ANY CLEAR
SLOT POSITIONING HAVE KEPT AT LEAST PARTLY CLOUDY WORDING
THROUGHOUT THE CWA.
LATE WEDNESDAY INTO THURSDAY MORNING WILL SEE A SHARP MID TO
UPPER LEVEL SHORTWAVE SHIFT OFF THE FRONT RANGE AND INTO THE
MISSOURI RIVER VALLEY. THE WAVE WEAKENS AS IT RUNS UP AGAINST THE
DOWNSTREAM RIDGE...BUT PORTIONS OF SOUTHERN IOWA SHOULD SEE
MEASURABLE SNOW THURSDAY MORNING. ALL MEDIUM RANGE SOLUTIONS PLACE
A NARROW BUT STRONG AREA OF DGZ FORCING BETWEEN 09Z AND 18Z ALONG
AND NORTH OF THE MISSOURI BORDER. HOWEVER...NAM SOUNDINGS ARE
NOTABLY DRIER IN THE DGZ COMPARED TO THE GFS AND EC. THE SYSTEM
WILL ALSO BE FIGHTING A WEDGE OF LOW-LEVEL DRY AIR THAT SHOULD
RESULT IN A SHARP PRECIP CUTOFF ALONG THE NORTHERN SIDE OF THE
LINE. FOR THE FORECAST PACKAGE...DID NOT CHANGE COVERAGE TOO MUCH
BUT INCREASED POPS TO HIGH CHANCES OVER THE SOUTH WITH THE
EXPECTATION OF THESE BEING UPPED TO LIKELIES OR CATEGORICAL ONCE
THE LOCATION OF THE GREATEST FORCING AND MOISTURE PROFILES ARE
BETTER RESOLVED. TOTAL SNOWFALL AMOUNTS LOOK TO BE AROUND OR LESS
THAN AN INCH GIVEN THE TRANSIENT NATURE OF THE SYSTEM AND INITAL
SURFACE DRY LAYER.
FRIDAY AND INTO THE WEEKEND LOOK TO REMAIN DRY WITH WEAK SOUTHERLY
FLOW/WAA BRINGING HIGHS BACK ABOVE FREEZING. SATURDAY WILL SEE A
AN UPPER LEVEL TROUGH SWING THROUGH THE REGION...BUT FORECAST
SOUNDINGS REMAIN MOSTLY DRY AND CONFIDENCE WAS NOT HIGH ENOUGH TO
INTRODUCE POPS IN ANY GIVEN LOCATION. A FEW LIGHT SNOW SHOWERS ARE
CERTAINLY NOT OUT OF THE REALM OF POSSIBILITIES WITH THE PASSAGE
OF THIS SYSTEM.
HOWEVER...THE WEATHER PATTERN TAKES A MORE ACTIVE TURN EARLY NEXT
WEEK AS A LONGWAVE TROUGH DIGS OVER THE ROCKIES AND SLOWLY
MIGRATES EAST TOWARDS THE CWA BY THE END OF THE PERIOD. THE GFS
AND EC ARE IN SOMEWHAT GOOD AGREEMENT WITH THE RESULTANT SURFACE
CYCLONE AND TAKE IT ON A COURSE NORTH OF THE CWA...WITH IOWA
REMAINING IN THE WARM SECTOR AND SEEING A MIX OF RAIN AND SNOW
ALONG THE ATTENDANT WARM/COLD FRONTAL BOUNDARIES.
&&
.AVIATION...16/18Z
ISSUED AT 1140 AM CST TUE DEC 16 2014
RATHER LOW CONFIDENCE FORECAST CONCERNING STRATUS. AT THE
MOMENT...PARTIAL CLEARING HAS DEVELOPED OVER WESTERN/CENTRAL
SECTIONS IN PATH OF STRONGEST COLD AIR ADVECTION. HRRR SHOWS THE
AREA EXPANDING A BIT THROUGH 01Z OR SO...THEN POSSIBLE BACKFILLING
OVER THE SOUTH AFT 02-03Z. FARTHER WEST...MORE STRATUS CONTINUES
AND ANOTHER WEAK TROUGH OVER MN MAY BRUSH NORTHEAST SECTIONS
THROUGH 02Z KEEPING MVFR CIGS THERE. GIVEN APPROACHING RIDGE
OVERNIGHT...HAVE OPTED TO GENERALLY STICK WITH MVFR CONDITIONS AND
PERSISTENCE. WILL MONITOR FOR POSSIBLE IMPROVEMENTS. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...REV
LONG TERM...SKOW
AVIATION...REV
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1140 AM CST TUE DEC 16 2014
.UPDATE...
ISSUED AT 607 AM CST TUE DEC 16 2014
THE WIND ADVISORY WILL BE ALLOWED TO EXPIRE AT 12Z. A HANDFUL OF
SITES ARE STILL AT SUSTAINED CRITERIA /26KTS/ BUT A GRADUAL
DOWNWARD TREND IS STILL EXPECTED AS NOTED IN THE SHORT TERM
SECTION BELOW.
&&
.SHORT TERM /TODAY/...
ISSUED AT 335 AM CST TUE DEC 16 2014
IMMEDIATE CONCERNS ARE PRECIP TRENDS AND WIND. PARENT SHORT WAVE
CONTINUES TO MOVE ACROSS IL WITH ONLY MINIMAL UPSTREAM INFLUENCE
FROM DAKOTAS/ONTARIO WAVE. LATEST RAP ANALYSIS SHOWS LITTLE IN THE
WAY OF OMEGA OR FORCING ACROSS FORECAST AREA...JUST SOME TOKEN MID
LEVEL LIFT ASSOCIATED WITH DAKOTAS/ONTARIO WAVE BARELY GENERATING
LIGHT SNOW/FLURRIES NW AND LOWER BASED H85/H7 OMEGA ALONG THE
DMX/DVN BORDER. NOT ENTIRELY SURE WHAT IS GENERATING THAT OUTSIDE
OF MINOR SEGMENT OF THETA-E ADVECTION DRIVEN MORE BY WRAP AROUND
MOISTURE THAN TEMPS. REGARDLESS...ANY LINGERING UPWARD VERTICAL
MOTION SHOULD WANE OVER THE NEXT SEVERAL HOURS. ANY PRECIP WILL BE
QUITE LIGHT AND TOKEN...BUT WITH TYPE PROBLEMATIC. IR SATELLITE
CLOUD TOP TEMPS AND SOUNDINGS SUGGEST ICE INTRODUCTION WILL VARY
SO FREEZING AND FROZEN HYDROMETEORS ARE BOTH POSSIBLE...AND EVEN
A BRIEF PERIOD OF LIQUID STILL POSSIBLE FAR EAST WITH WARM LAYER
TEMPS STILL 1-3C THERE. NEARLY ALL MODELS ARE UNDERESTIMATING THE
EXTENT OF STRATUS ACROSS THE GREATER MO VALLEY SO HAVE HELD ONTO
CLOUDS FOR MUCH OF THE DAY. LITTLE CONFIDENCE HOW LONG THEY WILL
HOLD ON...BUT CERTAINLY LONGER THAN MODELS SUGGEST.
NO CHANGES TO CURRENT WIND ADVISORY WITH SEVERAL SITES STILL HITTING
SUSTAINED CRITERIA. THEY SHOULD NOT LAST MUCH LONGER HOWEVER WITH
ISALLOBARIC EFFECTS DIMINISHING WITH PRESSURE RISE MAX INTO SERN
IA...AND MAX MSLP GRADIENT EXITING FORECAST AREA. RAP SOUNDINGS
SUGGEST MIXING WILL SUPPORT GUSTS NOT QUITE TO CRITERIA /39KTS/
BUT STILL WELL INTO THE 30S. TEMPS WILL BE FALLING THROUGH MUCH OF
THE DAY. THERE MAY BE A VERY MINOR REBOUND TOWARD MIDDAY BASED ON
RAW TEMP PLUMES...BUT HIGH TEMPS WILL BE AT BEGINNING OF VALID
PERIOD.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 335 AM CST TUE DEC 16 2014
THE SYNOPTIC PATTERN HAS FINALLY CHANGED AND WE WILL SEE COOLER
AND SOMEWHAT MORE ACTIVE WEATHER ACROSS CENTRAL IOWA FOR THE NEXT
SEVEN DAYS AND BEYOND. AT 500 MB...A COMPACT LOW PRESSURE CENTER
MOVING OVER MINNESOTA LATER TODAY WILL SLIDE QUICKLY EASTWARD OVER
THE GREAT LAKES TONIGHT AND WEDNESDAY. AT THE SURFACE...THIS
DEPARTURE WILL BE REFLECTED BY A RIDGE OF HIGH PRESSURE BUILDING
DOWN THE DAKOTAS AND INTO IOWA LATE TONIGHT THROUGH
WEDNESDAY...REINFORCING THE COLDER AIR BUT ALSO PROHIBITING
PRECIPITATION ACROSS THE STATE.
MEANWHILE...A LARGE AND BROAD 500 MB TROUGH WILL BUILD OVER THE
ROCKIES AND WESTERN U.S. ON WEDNESDAY...AND EVENTUALLY PROGRESS
EASTWARD AS A SOMEWHAT CONFUSED AREA OF GENERAL TROUGHINESS
PERSISTING FOR THE REST OF THE WORK WEEK. THE SURFACE RIDGE
DISCUSSED EARLIER WILL STUBBORNLY CLING TO MINNESOTA AND MUCH OF
IOWA DURING THIS TIME EVEN AS ATMOSPHERIC MOISTURE ABOVE A VERY
SHALLOW NEAR SURFACE LAYER INCREASES DRAMATICALLY AROUND THURSDAY.
FORECAST SOUNDINGS ARE UNANIMOUS IN ILLUSTRATING THIS MOISTURE
INCREASE COINCIDENT WITH THE ARRIVAL OF THE BROAD 500 MB
TROUGH...HOWEVER...ANY FORCING ASSOCIATED WITH THIS UPPER FEATURE
WILL BE MODEST AT BEST AND THE RESULT WILL LIKELY BE THICK LAYERED
CLOUDS AND SOME FLURRIES OR LIGHT SNOW AT TIMES. HAVE INCLUDED LOW
POPS IN THE 20 TO 30 RANGE FOR SOME OF THIS PERIOD...BUT NO
SIGNIFICANT IMPACTS ARE ANTICIPATED.
A MORE INTERESTING ATMOSPHERIC FEATURE APPEARS IN THE FORM OF A
LONGWAVE BUT INITIALLY SUBTLE 500 MB TROUGH MOVING ASHORE OVER THE
PACIFIC U.S. COAST AROUND SATURDAY. AS THIS TROUGH SUBSEQUENTLY
MOVES EASTWARD OVER THE ROCKIES AND EMERGES OVER THE HIGH PLAINS
AND MIDWEST IT SHOULD INTENSIFY TO SOME EXTENT...THEN BE
REINFORCED BY TRAILING SHORTWAVES AND CARVE OUT A LARGE CENTRAL
U.S. TROUGH EARLY NEXT WEEK. THERE IS OF COURSE A HIGHER DEGREE OF
UNCERTAINTY AT SUCH A LONG RANGE...HOWEVER...IT DOES APPEAR THAT
THERE WILL BE A DECENT CHANCE FOR SOME KIND OF PRECIPITATION
ACROSS IOWA SOMETIME BETWEEN AROUND SUNDAY NIGHT AND TUESDAY OF
NEXT WEEK. EVEN SO...IT REMAINS TO BE SEEN WHETHER TEMPERATURES
WOULD BE MORE SUPPORTIVE OF RAIN OR SNOW FROM THIS SYSTEM. FOR NOW
HAVE ADVERTISED CHANCE POPS EARLY NEXT WEEK AND IT WILL TAKE SOME
TIME BEFORE THERE IS ANY DEGREE OF CONFIDENCE TO RAISE OR
ELIMINATE THEM.
&&
.AVIATION...16/18Z
ISSUED AT 1140 AM CST TUE DEC 16 2014
RATHER LOW CONFIDENCE FORECAST CONCERNING STRATUS. AT THE
MOMENT...PARTIAL CLEARING HAS DEVELOPED OVER WESTERN/CENTRAL
SECTIONS IN PATH OF STRONGEST COLD AIR ADVECTION. HRRR SHOWS THE
AREA EXPANDING A BIT THROUGH 01Z OR SO...THEN POSSIBLE BACKFILLING
OVER THE SOUTH AFT 02-03Z. FARTHER WEST...MORE STRATUS CONTINUES
AND ANOTHER WEAK TROUGH OVER MN MAY BRUSH NORTHEAST SECTIONS
THROUGH 02Z KEEPING MVFR CIGS THERE. GIVEN APPROACHING RIDGE
OVERNIGHT...HAVE OPTED TO GENERALLY STICK WITH MVFR CONDITIONS AND
PERSISTENCE. WILL MONITOR FOR POSSIBLE IMPROVEMENTS. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SMALL
SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...REV
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
315 PM EST TUE DEC 16 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 315 PM EST TUE DEC 16 2014
19Z SFC ANALYSIS SHOWS A FAIRLY DEEP AREA OF LOW PRESSURE LIFTING
NORTHEAST THROUGH THE EASTERN GREAT LAKES. THE COLD FRONT ASSOCIATED
WITH THIS SYSTEM IS NOW THROUGH EASTERN KENTUCKY AND AS A RESULT
GUSTY WEST WINDS ARE BRINGING IN A COLDER AIR MASS. AS IT DOES SO...
IT IS ALSO GENERATING A SUBSTANTIAL AREA OF DRIZZLE AND LOWER CIGS.
TEMPERATURES VARY FROM THE LOW 40S WEST TO NEAR 50S EAST ACROSS THE
CWA WITH DEWPOINTS IN THE UPPER 30S TO LOWER 40S.
THE MODELS ARE IN DECENT ENOUGH AGREEMENT ALOFT THROUGH THE SHORT
TERM PORTION OF THE FORECAST AS THEY ALL DAMPEN OUT THE CURRENT
TROUGH OVER THE AREA WHILE ABSORBING IT INTO THE MAIN MID LEVEL LOW
OVER THE UPPER MIDWEST. THIS WILL KEEP FAST...WEST TO EAST...FLOW
ABOVE EASTERN KENTUCKY INTO THE DAY WEDNESDAY...THOUGH MODEL
DIFFERENCES START TO MAGNIFY BY DAWN. THE ECMWF IS SLOWER MOVING
THIS MIDWEST LOW EAST COMPARED TO THE GEM AND GFS WHICH WILL ALSO
SERVE TO KEEP OUR HEIGHTS SLIGHTLY SUPPRESSED INTO WEDNESDAY EVENING.
DESPITE THIS...THE PREFERRED ECMWF DOES NOT LAG IN BRINGING THE NEXT
BATCH OF ENERGY INTO THE REGION FROM A QUICK MOVING WAVE PASSING OUT
OF THE SOUTHERN PLAINS. THIS WILL SEEP INTO OUR SOUTHWEST PARTS BY
THURSDAY MORNING. FOR THE FORECAST...FOLLOWED A BLEND OF THE HIGHER
RESOLUTION HRRR AND NAM12 WITH SOME ADJUSTMENT TOWARD THE MAIN
FEATURES IN THE LATEST ECMWF.
A DREARY EVENING AND OVERNIGHT IS ANTICIPATED THROUGH EASTERN
KENTUCKY AS LOW CIGS AND DRIZZLE WILL DOMINATE UNDER A SUBSIDENCE
INVERSION...PARTICULARLY OVER THE NORTHERN HALF THE CWA. THERE IS A
CONCERN THAT THE HIGHER POINTS OF EASTERN KENTUCKY FALL TO
FREEZING...OR A COUPLE OF DEGREES BELOW...BY DAWN GIVEN THE CAA
OVERNIGHT. COMBINED WITH THE AREAS OF DRIZZLE STILL AROUND...THERE
WILL BE A THREAT OF FREEZING DRIZZLE GENERALLY ABOVE 2000 FEET. FOR
THIS...WILL ISSUE AN SPS FROM LATE TONIGHT INTO THURSDAY MORNING FOR
OUR SOUTHEASTERN-MOST COUNTIES WITH THAT HIGHER TERRAIN. THE LOW
CLOUDS WILL PROBABLY HOLD TOUGH INTO THE FIRST PART OF THE DAY
WEDNESDAY BUT THERE COULD BE SOME BREAKUP MAKING FOR A BRIEF PERIOD
OF SUNSHINE DURING THE AFTERNOON AHEAD OF THE NEXT BATCH OF HIGHER
CLOUDS DUE IN HERE LATER THAT EVENING. THESE NEXT CLOUDS WILL QUICKLY
INCREASE AND LOWER THROUGH THE NIGHT WITH EVEN SOME LIGHT RAIN OR
SNOW POSSIBLE BY DAWN THURSDAY...THOUGH TEMPERATURES WILL BE MILDER
THAN TONIGHT IN MOST PLACES.
USED THE BCCONSSHORT AS A STARTING POINT FOR THE T/TD/WIND GRIDS FOR
THE FIRST 20 HOURS BEFORE POPULATING WITH THE SUPERBLEND THEREAFTER.
THESE WERE THEN SUBJECTED TO MINOR ADJUSTMENTS FOR TERRAIN EFFECTS
MAINLY TONIGHT AND WEDNESDAY NIGHT. AS FOR POPS...ENDED UP JUST ABOVE
THE HIGHER MET MOS GUIDANCE TONIGHT GIVEN THE LOW QPF BUT MODERATE
POPS WITH EXTRA EMPHASIS ON DRIZZLE AS PTYPE. ALSO...FOR LATE
WEDNESDAY WENT A BIT HIGHER THEN GUIDANCE IN THE SOUTHWEST GIVEN THE
FAST FLOW REGIME.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 245 PM EST TUE DEC 16 2014
PROGRESSIVE PATTERN WILL CONTINUE THROUGH THE EXTENDED. THE PERIOD
WILL START AS A MID LEVEL TROUGH CROSSES INTO THE OHIO RIVER VALLEY
ON THURSDAY. MODELS HAVE TRENDED MORE AGGRESSIVE WITH THIS FEATURE
WITH THE 12Z SUITE OF MODELS WITH GFS EVEN SHOWING SOME MODEST LIFT
ABOVE 850MB. THE MAIN LIMITING FACTOR FOR PRECIPITATION ON THURSDAY
WILL BE THE LOW LEVEL DRY AIR. HOWEVER...GIVEN THE DEEP MOISTURE
STARTING AROUND 5KFT...THIS SHOULD BE ENOUGH TO AT LEAST WARRANT A
CHANCE OF MEASURABLE PRECIPITATION REACHING THE GROUND.
HOWEVER...THIS PRECIPITATION MAY DRY UP AS IT TRIES TO PUSH
NORTHWARD THROUGH THE DAY. THUS...PLAN TO GO WITH CHANCE POPS ACROSS
THE SOUTH...TRAILING OFF TO SLIGHT CHANCE IN THE NORTH. ALL OF THIS
PRECIPITATION AS EXPECTED WILL REMAIN LIGHT...BUT SOME SNOWFLAKES
COULD MIX IN AT TIMES THROUGH THE DAY. HIGH PRESSURE WILL PROVIDE
DRY WEATHER THURSDAY NIGHT THROUGH FRIDAY.
THE WEATHER TURNS MORE INTERESTING BY FRIDAY NIGHT THROUGH SATURDAY
AS A SOUTHERN STREAM SHORTWAVE PUSHES EAST ACROSS THE SOUTHERN TIER
OF THE US. THIS SYSTEM IS NOT EXPECTED TO GET MUCH HELP FROM THE
NORTHERN STREAM...AND THUS...NOT MUCH COLD AIR IS EXPECTED TO GET
WORKED INTO THIS SYSTEM. THIS FACT...COMBINED WITH A WEAKENING AREA
OF LOW PRESSURE TRACKING ACROSS THE GULF COAST STATES WILL LIKELY
YIELD VERY LITTLE SNOW POTENTIAL. HOWEVER...WE ARE ON THE NORTH SIDE
OF THIS SYSTEM...WHICH WOULD BE THE BEST SPOT FOR ANY SNOW.
PRECIPITATION IS EXPECTED TO SPREAD INTO THE AREA LATE FRIDAY NIGHT
AND CONTINUE THROUGH SATURDAY. BEST SNOW POTENTIAL MAY BE AT THE
ONSET FRIDAY NIGHT...BUT AGAIN...PRECIPITATION RATES MAY BE FAIRLY
LIMITED...KEEPING SNOW AMOUNTS FROM BEING ALL THAT HIGH. IN
FACT...WE COULD SEE A MIX OF RAIN/SNOW RIGHT THROUGH SATURDAY WITH
VERY LITTLE SNOW ACCUMULATION FOR MUCH OF THE AREA. THE ECMWF
REMAINS THE COLDER OF THE MODELS SUGGESTING BETTER SNOW
POTENTIAL...WHILE THE GFS HAS MAINTAINED ITS ALL RAIN FORECAST.
GOING WITH A COMPROMISE ON HIGHS ON SATURDAY WOULD BE TEMPERATURES
AROUND 40 BY THE AFTERNOON ACROSS MUCH OF THE AREA. ITS POSSIBLE
SOME COOLER READINGS IN THE 30S COULD KEEP MORE SNOW GOING A BIT
LONGER ACROSS THE NORTHERN PORTION OF THE AREA...BUT WITH WEAK
PRECIP RATES...COMBINED WITH ABOVE FREEZING TEMPERATURES...SHOULD
REALLY CUT INTO ANY SNOWFALL POTENTIAL EVEN WITH THE COLDER ECMWF
SOLUTION. PRECIPITATION WILL WIND DOWN BY SATURDAY NIGHT GOING OVER
TO A PERIOD OF LIKELY DRIZZLE.
DRY WEATHER WILL RETURN FOR SUNDAY AND PERSIST INTO THE EARLY PART
OF NEXT WEEK. TEMPERATURES ARE EXPECTED TO REMAIN FAIRLY SEASONABLE
THROUGH THE END OF THE FORECAST PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 145 PM EST TUE DEC 16 2014
THE COLD FRONT HAS PASSED THROUGH EASTERN KENTUCKY TAKING THE LIGHT
RAINS ALONG WITH IT. HOWEVER...A LARGE AREA OF DRIZZLE DOES FOLLOW
THIS BOUNDARY AND WILL AFFECT MUCH OF THE FA INTO THE EVENING. IN
FACT...FORECAST SOUNDINGS AND TIME HEIGHTS CONTINUE TO INDICATE A
STRONG SUBSIDENCE INVERSION BEHIND THE FRONT...WITH LOW LEVEL
MOISTURE TRAPPED THROUGH MOST OF THE TAF PERIOD. THIS WILL LEAD TO
LOWERING CIGS AND THE POTENTIAL FOR DRIZZLE THROUGH WEDNESDAY
MORNING. FUEL ALTERNATES ARE LIKELY AS WE HEAD INTO THE OVERNIGHT
HOURS. ANOTHER CONCERN WILL BE THE WINDS. EXPECT WINDS AT THE SURFACE
TO STAY UP FROM THE WEST WITH GUSTS BETWEEN 15 AND 20 KTS THROUGH
THE REST OF THE AFTERNOON. THE OVERNIGHT SUBSIDENCE INVERSION SHOULD
ALLOW SFC WINDS TO DIE DOWN AND BECOME LIGHT FOLLOWING SUNSET. THE
WINDS WILL PICK UP FROM THE WEST TO NORTHWEST DURING THE DAY
WEDNESDAY AT 5 TO 10 KTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
205 PM EST TUE DEC 16 2014
.UPDATE...
ISSUED AT 205 PM EST TUE DEC 16 2014
DID A QUICK UPDATED TO FINE TUNE THE POPS AND WX THROUGH THE REST OF
THE AFTERNOON ALSO MATCHED UP THE HOURLY TEMPS AND DEWPOINTS WITH THE
CURRENT CONDITIONS AND TRENDS. THESE UPDATED GRIDS HAVE BEEN SENT TO
THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1020 AM EST TUE DEC 16 2014
14Z SFC ANALYSIS SHOWS A FAIRLY DEEP AREA OF LOW PRESSURE MOVING
THROUGH THE NORTHERN OHIO VALLEY. A COLD FRONT EXTENDS SOUTH OF THIS
AND IS CURRENTLY CROSSING EAST KENTUCKY...JUST REACHING JKL. A LINE
OF LIGHT RAIN ACCOMPANIES THIS BOUNDARY ALONG WITH AREAS OF DRIZZLE
IN ITS WAKE. THE EARLIER THUNDERSTORMS COMING OUT OF SOUTHERN INDIANA
APPEARS TO HAVE SETTLED SO THAT LIGHT RAIN AND DRIZZLE WILL BE THE
MAIN WEATHER TYPE FOR OUR AREA INTO THE AFTERNOON. IN ADDITION TO THE
PCPN CHANCES WITH THE FRONT...GUSTY WINDS FROM THE WEST ACCOMPANY AND
TRAIL THE BOUNDARY. THESE WILL BRING IN COOLER AIR TO EASTERN
KENTUCKY THROUGH THE REST OF THE DAY. THIS MEANS THAT WE HAVE LIKELY
REACHED OUR HIGHS FOR THE DAY IN MOST PLACES...PARTICULARLY IN THE
EAST WHERE PATCHES OF SUNSHINE IN THE WAKE OF THE LOW/S WARM FRONT
HAVE SENT READINGS INTO THE LOW AND MID 50S. 40S WILL FOLLOW WHILE
DEWPOINTS WILL REMAIN RATHER UNIFORM ON EITHER SIDE OF THE FRONT...
GENERALLY IN THE LOW AND MID 40S. HAVE UPDATED THE FORECAST TO
REFLECT THE ABOVE CHANGES AND TO ALSO INFUSE SOME OF THE LATEST HIGH
RESOLUTION GUIDANCE FROM THE HRRR AND 12Z NAM. THESE GRIDS HAVE BEEN
SENT TO THE NDFD AND WEB SERVERS. WILL ALSO UPDATE THE ZONES AND
HWO...MAINLY TO REMOVE THE THUNDER CHANCES THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 351 AM EST TUE DEC 16 2014
A SURFACE LOW PRESSURE CENTER IS CURRENTLY RIDING JUST NORTH OF THE
OHIO RIVER VALLEY...LOCATED SOMEWHERE FAIRLY CLOSE TO INDIANAPOLIS.
AS THIS LOW CONTINUES TO PROGRESS ENEWARD...IT IS CURRENTLY PULLING
A WARM FRONT FROM SW TO NE ACROSS THE CWA /SHOULD BE THROUGH BY
AROUND 12Z/...AND THEN WILL FOLLOW UP WITH A COLD FRONT PASSING
THROUGH THE CWA FROM WEST TO EAST BETWEEN APPROX 10Z AND 15Z. WITH
EACH OF THESE SYSTEMS...WE ARE CONTINUING TO PICK UP LIGHT SHOWER
ACTIVITY...WITH SCATTERED TO WIDESPREAD RETURNS ACROSS PORTIONS OF
EASTERN KY IN RESPONSE TO THE WARM FRONT...AND ANOTHER AREA JUST
ALONG THE COLD FRONT ACROSS WEST CENTRAL KY. UNFORTUNATELY...MODELS
ARE STILL HAVING A HARD TIME SHOWING A WELL DEFINED PRECIP FORECAST
FOR THIS SYSTEM. LEANED ON A MIXTURE OF RADAR TRENDS...THE HRRR AND
RUC /WHICH SEEMED TO HAVE THE BEST HANDLE ON THE CURRENT
SITUATION/...AND SOME LESSER INFLUENCE FROM A BLEND OF OTHER HI RES
MODELS...TO COME UP WITH THE FORECAST FOR THE PROGRESSION OF THE RAIN
AS WE HEAD THROUGH TODAY. AS SUCH...THE CURRENT RAIN /AND ISOLATED
THUNDER/ OVER CENTRAL KY SHOULD MAKE IT INTO OUR WESTERN CWA WITHIN
THE NEXT FEW HOURS /AROUND 10 TO 11Z/...WHILE CHANCES WILL INCREASE
ALONG MUCH OF THE NE CWA AS THE LOW TRACKS JUST TO OUR NORTH.
DID CONTINUE TO NOTE THAT MOST OF THIS MOISTURE SHOWS UP AS BEING
FAIRLY SHALLOW IN THE FORECAST SOUNDINGS THROUGH TODAY...SO DON/T
EXPECT ANYTHING OTHER THAN LIGHT SHOWERS. ONCE DRY AIR MOVES IN
BEHIND THE COLD FRONT THIS AFTERNOON...EXPECT IT TO ONCE AGAIN TRAP
A LAYER OF LOW LEVEL MOISTURE NEAR THE SURFACE...WHERE IT WILL
LINGER THROUGH AROUND 15Z TOMORROW...LONG AFTER THE INFLUENCE OF THE
LOW PRESSURE SYSTEM. AS SUCH...WHILE SOME OF THIS MOISTURE WILL FALL
AS LIGHT RAIN DURING THE DAY TODAY...IT STANDS TO REASON THAT IT
COULD BE MIXED IN WITH DRIZZLE IN SOME LOCATIONS...AND THEN CHANGE
OVER TO ALL DRIZZLE TONIGHT AS MOISTURE BECOMES INCREASINGLY SHALLOW.
TRIED TO REFLECT THIS IN THE WEATHER GRIDS...WITH A MIXTURE OF
ISOLATED/SLIGHT CHANCE RAIN AND PATCHY DRIZZLE...THEN LIGHT DRIZZLE
LINGERING THROUGH TOMORROW MORNING.
TEMPS WILL RISE SOME THROUGHOUT THE MORNING...WITH SOME PLACES IN
THE EAST POSSIBLY PULLING OUT SOME LOW 50S DUE TO THE WAA BEHIND THE
WARM FRONT...BUT SHOULD GENERALLY FALL FROM WEST TO EAST DURING THE
AFTERNOON AS COLDER AIR FILTERS IN BEHIND THE COLD FRONTAL PASSAGE.
WINDS WILL ALSO CONTINUE TO BE GUSTY AHEAD AND JUST BEHIND THE
FRONT...DYING DOWN AS WE HEAD INTO THE EVENING HOURS. THE PUSH OF
COLDER AIR COULD ALLOW FOR SOME BELOW FREEZING TEMPS BY
OVERNIGHT...NAMELY IN THE HIGHEST TERRAIN IN THE SE. AS SUCH...SOME
FREEZING DRIZZLE IN THESE LOCATIONS CANNOT BE RULED OUT. DID GO AHEAD
AND KEEP A MENTION OF THIS IN THE GRIDS...BUT WILL NEED TO KEEP AN
EYE OUT AS WE HEAD INTO TONIGHT IN CASE ANY FURTHER ACTION NEEDS TO BE
TAKEN. HIGHS WEDNESDAY WILL FALL BELOW SEASONABLE NORMS ONCE
MORE...TOPPING OUT IN THE LOW 40S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 419 AM EST TUE DEC 16 2014
THE MODELS ARE IN GOOD AGREEMENT WITH A PROGRESSIVE LONG WAVE PATTERN
TO HOLD ON THROUGH THE END OF THE WEEK...FOLLOWED BY AMPLIFICATION
INTO EARLY NEXT WEEK. DETAILS WITHIN THE LONG WAVE PATTERN CONTINUE
TO BE CHALLENGING...SO HAVE STUCK FAIRLY CLOSE TO A BLEND OF THE
GUIDANCE...WHILE STEERING THE FORECAST TOWARDS GENERAL MODEL TRENDS
SEEN IN THE PAST FEW DAYS.
THE SOUTHERN STREAM WILL MAINLY BE PROVIDING OUR WEATHER THROUGH THE
PERIOD...AS TROUGHING ACROSS THE SOUTHWEST CONUS GRADUALLY
TRANSLATES EAST. INITIALLY...A DAMPENING SHORT WAVE TROUGH WILL EJECT
OUT OF THE MAIN TROUGH...AFFECTING OUR AREA VERY LATE WEDNESDAY NIGHT
INTO THURSDAY. FORCING WILL BE CONFINED TO THE MID AND UPPER
LEVELS...AND DEEPER MOISTURE CONTINUES TO BE LACKING ACROSS EASTERN
KENTUCKY. AS SUCH...WILL MAINTAIN A SLIGHT CHANCE OF SNOW/RAIN
GENERALLY NEAR AND SOUTH OF THE HAL ROGERS AND HIGHWAY 80 CORRIDORS.
THE MAIN TROUGH AXIS WILL THEN MOVE ACROSS THE GULF COAST STATES AND
EVENTUALLY SWING ACROSS THE SOUTHERN APPALACHIANS BY THE WEEKEND.
THE MODELS HAVE GENERALLY SHOWN A MORE SOUTHERLY TRACK WITH THE
ASSOCIATED SURFACE LOW. THE GFS HAS ALSO TRENDED NOTICEABLY SLOWER
WITH THE PRECIPITATION ONSET. THE THERMAL PROFILES CONTINUE TO DIFFER
QUITE A BIT...WITH THE ECMWF COOLER AND THE GFS WARMER. AS
SUCH...HAVE MAINTAINED A BROAD BRUSH WITH THE RAIN/SNOW POTENTIAL
UNTIL CONFIDENCE INCREASES. PRECIPITATION WILL BEGIN FRIDAY
NIGHT...WITH THE OVERALL BEST CHANCE FOR THE ENTIRE AREA ON SATURDAY.
PRECIPITATION WILL THEN TAPER OFF QUICKLY SATURDAY NIGHT...WITH ONLY
A SMALL CHANCE OF A FEW LINGERING SHOWERS IN THE FAR SOUTHEAST
THROUGH SUNDAY MORNING WITH UPSLOPE FLOW IN PLACE. HIGH PRESSURE WILL
THEN TAKE HOLD INTO EARLY NEXT WEEK...BEFORE A DEEPER TROUGH
APPROACHES FROM THE WEST.
BELOW NORMAL TEMPERATURES WILL REIGN THROUGH THE PERIOD. STUCK FAIRLY
CLOSE TO THE BLENDED GUIDANCE GIVEN THE UNCERTAINTY...HOWEVER DID
ALLOW FOR A MORE DIURNALLY LIMITED TEMPERATURE REGIME DURING THE
PERIODS OF GREATER PRECIPITATION CHANCES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 145 PM EST TUE DEC 16 2014
THE COLD FRONT HAS PASSED THROUGH EASTERN KENTUCKY TAKING THE LIGHT
RAINS ALONG WITH IT. HOWEVER...A LARGE AREA OF DRIZZLE DOES FOLLOW
THIS BOUNDARY AND WILL AFFECT MUCH OF THE FA INTO THE EVENING. IN
FACT...FORECAST SOUNDINGS AND TIME HEIGHTS CONTINUE TO INDICATE A
STRONG SUBSIDENCE INVERSION BEHIND THE FRONT...WITH LOW LEVEL
MOISTURE TRAPPED THROUGH MOST OF THE TAF PERIOD. THIS WILL LEAD TO
LOWERING CIGS AND THE POTENTIAL FOR DRIZZLE THROUGH WEDNESDAY
MORNING. FUEL ALTERNATES ARE LIKELY AS WE HEAD INTO THE OVERNIGHT
HOURS. ANOTHER CONCERN WILL BE THE WINDS. EXPECT WINDS AT THE SURFACE
TO STAY UP FROM THE WEST WITH GUSTS BETWEEN 15 AND 20 KTS THROUGH
THE REST OF THE AFTERNOON. THE OVERNIGHT SUBSIDENCE INVERSION SHOULD
ALLOW SFC WINDS TO DIE DOWN AND BECOME LIGHT FOLLOWING SUNSET. THE
WINDS WILL PICK UP FROM THE WEST TO NORTHWEST DURING THE DAY
WEDNESDAY AT 5 TO 10 KTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...JMW
LONG TERM...GEOGERIAN
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1147 AM CST TUE DEC 16 2014
.AVIATION...
DRY AIR WILL RESULT IN VFR CONDITIONS WITH MOSTLY CLEAR SKIES AND
EXCELLENT VISIBILITIES THROUGH WEDNESDAY. NORTHWEST WINDS MAY
OCCASIONALLY GUST 15 TO 20 KNOTS THROUGH SUNSET TODAY...OTHERWISE
PREVAILING WINDS WILL BE MOSTLY 10 KNOTS OR LESS. 22/TD
&&
.PREV DISCUSSION... /ISSUED 345 AM CST TUE DEC 16 2014/
SHORT TERM...
COLD FRONT IS CURRENTLY LOCATED ALONG A GULFPORT TO HOUMA LINE AND
MOVING EASTWARD. THERE/S NOT A WHOLE LOT OF RAINFALL ALONG THE
BOUNDARY WITH LOCATIONS SEEING AT MOST ABOUT A QUARTER OF AN INCH
BUT MORE COMMONLY LESS THAN ONE TENTH. WINDS HAVE GUSTED TO AS HIGH
AS 30 KNOTS BUT THOSE CONDITIONS WILL BE QUITE BRIEF AND RIGHT ALONG
THE LINE OF SHOWERS. TEMPERATURES ARE GENERALLY DROPPING ABOUT 6
DEGREES AS THE FRONT PASSES BUT THE MORE SIGNIFICANT CHANGE IS
DEWPOINTS FALLING AROUND 10 DEGREES. THE HRRR QPF OUTPUT IS SPOT ON
FOR INITIATION AND HAS BEEN DOING WELL FOR THE LAST FEW HOURS. GOING
OFF THAT...WHATS LEFT OF THIS LINE OF SHOWERS MOVING THROUGH SHOULD
BE PUSHING OFFSHORE BY SUNRISE AND OUT OF THE ENTIRE CWA BY NOON.
TODAY/S HIGHS WILL BE A FIGHT BETWEEN INSOLATION AND COOL AIR MOVING
IN TODAY AS SURFACE HIGH PRESSURE BUILDS IN. TEMPERATURES WILL DROP
ABOUT 10 TO 15 DEGREES FROM MONDAY OR LOWER TO UPPER 60S WHICH IS
RIGHT ABOUT NORMAL FOR THIS TIME OF YEAR. MOVING INTO THE OVERNIGHT
HOURS...THE COMBINATION OF LIGHT WINDS AND CLEAR SKIES SHOULD ALLOW
FOR GOOD RADIATIONAL COOLING. AM AT OR SLIGHTLY BELOW GUIDANCE ON
FCST LOWS.
LONG TERM...
A BRIEF COOLING TREND WILL PERSIST ON WEDNESDAY AS HIGH PRESSURE
BUILDING IN FROM THE NORTH CONTINUES TO BRING IN COLDER AND DRIER
AIR. THIS WILL BRING HIGHS DOWN A FEW DEGREES MORE FROM TUESDAY TO
NEAR 60 ON WEDNESDAY. THIS COOL DOWN WILL BE BRIEF AS THE SFC RIDGE
QUICKLY SLIDES EAST AND SOUTHEASTERLY FLOW & MOISTURE BEGINS TO
RETURN.
THE NEXT EVENT TO IMPACT THE AREA COMES IN LATE THIS WEEK. MODELS
SHOW A WEAKER UPPER LEVEL TROUGH SWINGING ACROSS THE BAJA OF
CALIFORNIA ON WEDNESDAY. A WEAKER PORTION OF THIS TROUGH WILL SHOOT
NORTHEAST ACROSS THE CENTRAL PLAINS WEDNESDAY NIGHT. AN ASSOCIATED
CONVERGENCE ZONE WILL DEVELOP ACROSS EAST TEXAS AND NORTHERN
LOUISIANA AS A RESULT. A FEW SHOWERS ALONG THIS BOUNDARY COULD NUDGE
INTO THE NORTHWESTERN PORTIONS OF THE CWA THURSDAY. THE MAIN PIECE
OF THE UPPER TROUGH TO THE WEST WILL BEGIN PROGRESSING EAST ACROSS
NEW MEXICO AND TEXAS ON FRIDAY. AS SURFACE LOW WILL DEVELOP JUST
AHEAD OF THIS UPPER LOW AND TRACK ACROSS THE CWA FRIDAY INTO FRIDAY
NIGHT. THIS WILL BE THE MAIN FOCUS FOR SHOWERS AND POSSIBLY A FEW
THUNDERSTORMS. INSTABILITY DOES APPEAR TO BE HIGHER CLOSER TO THE
COAST AND THUS COASTAL PARISHES AND COUNTIES IS WHERE THE STRONGER
ACTIVITY WILL BE. DRYING WILL THEN TAKE PLACE SATURDAY...ESPECIALLY
IN THE AFTERNOON HOURS WITH MUCH COOLER CONDITIONS SATURDAY AND
SUNDAY. HIGHS WILL STRUGGLE TO REACH 60 ON SATURDAY AND EVEN LESS
LIKELY ON SUNDAY. LOWS WILL BE JUST AS COOL AS WELL WITH MINS IN THE
UPPER 30S TO MID 40S.
MEFFER
AVIATION...COLD FRONT AND ASSOCIATED LINE
SHRA HAVE ALREADY MOVED THROUGH THE MAJORITY OF THE TERMINALS AND
VFR CONDITIONS ARE SETTING RIGHT BACK IN. WINDS WILL REMAIN OUT OF
THE NW/NNW THROUGH TODAY BUT SHOULD QUICKLY RELAX AFTER 3Z
TONIGHT...IN FACT THE SOUTHSHORE TERMINALS WILL LIKELY SEE WINDS
DROP SIGNIFICANTLY TONIGHT EVEN AFTER A COLD FRONTAL PASSAGE. OTHER
THAN THAT EVERYTHING SHOULD REMAIN QUIET. /CAB/
MARINE...WINDS BEHIND THE COLD FRONT THIS MORNING WILL REMAIN
ELEVATED FOR A SHORT WHILE BUT EXPECT THEM TO DROP BELOW SCS
HEADLINE CRITERIA BEFORE MIDDAY. CAA IS JUST NOT THAT STRONG BEHIND
THE FRONT COMBINE THAT WITH THE ASSOCIATED SFC LOW BEING RATHER FAR
NORTH AND HIGH PRESSURE QUICKLY BUILDING BACK INTO THE REGION
OFFSHORE WINDS WILL LIKELY BE 10-15 KTS TONIGHT IN THE OUTER WATERS.
HIGH PRESSURE SHOULD KEEP THINGS RELATIVELY QUIET THROUGH THU NIGHT
AND THEN DEPENDING ON THE EVENTUAL TRACK OF THE NEXT SFC LOW ONSHORE
WINDS LOOK LIKE THEY SHOULD BEGIN TO RAMP BACK UP FRI WITH SCY
CONDITIONS POSSIBLE FRI THROUGH SAT. /CAB/
DECISION SUPPORT...
DSS CODE...GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 62 34 58 42 / 0 0 0 10
BTR 64 37 61 44 / 0 0 0 10
ASD 66 35 61 42 / 10 0 0 0
MSY 65 44 60 48 / 10 0 0 0
GPT 65 38 59 44 / 10 0 0 0
PQL 69 35 61 39 / 20 0 0 0
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
312 PM EST TUE DEC 16 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 536 AM EST TUE DEC 16 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SRN STREAM SHRTWV/LOW OVER
NRN IL AND A NRN STREAM SHRTWV ACROSS NW ONTARIO INTO NW MN. AT THE
SFC...LOW PRES WAS LOCATED OVER NRN IL WITH A TROUGH TO THE NORTH
INTO ERN UPPER MI. 295K-300K ISENTROPIC LIFT AHEAD OF THE NRN IL LOW
HAS BROUGHT AN INCREASE IN PCPN COVERAGE/INTENSITY ACROSS CNTRL
UPPER MI WHILE 850-700 FGEN HAS SUPPORTED THE SNOW INTO WRN UPPER
MI. NRLY LOW LEVEL FLOW WITH THE TIGHTENING PRES GRADIENT BEHIND THE
TROUGH HAS BROUGHT COLDER AIR INTO WRN UPPER MI CHANGING THE RAIN TO
SNOW AT CMX/IWD/LNL. EVEN THROUGH TEMPS HAVE ALSO FALLEN BELOW 32F
AT KMQT...THE CIRCULATION AROUND THE SRN STREAM LOW HAS MAINTAINED
AN ELEVATED WARM LAYER (AROUND 850 MB FROM 1C TO 3C) OVER CENTRAL
UPPER MI. EVEN WITH AIR TEMPS FALLING BELOW FREEZING...THE RECENT
WARM CONDITIONS HAVE LIMITED GLAZE POTENTIAL AS MOST SURFACES HAVE
NOT COOLED OFF AS FAST.
TODAY...AS THE SRN STREAM SHRTWV LIFTS TO THE NW THE NRN STREAM
SHRTWV WILL BECOME THE DOMINANT FEATURE LATE TODAY INTO TONIGHT.
EXPECT THAT THE LINGERING WARM LAYER WILL SUPPORT A BRIEF PERIOD OF
LIGHT FREEZING RAIN OR SLEET THROUGH AROUND 14Z. THE BEST
CHANCE FOR ANY ICING WOULD BE OVER THE HIGHER TERRAIN WHERE TEMPS
HAVE ALREADY FALLEN OFF BELOW FREEZING. OTHERWISE...THE RAIN SNOW
CHANGE OVER IS EXPECTED TO MOVE INTO THE ERN CWA BY AFTERNOON WITH
ALL SNOW AT ERY AFTER 21Z. THE NRN STREAM SHRTWV WITH INCREASING
700-500 MB QVECTOR CONV WILL SUPPORT LIGHT TO MODERATE SNOW ACROSS
UPPER MI TODAY. 1 TO 4 INCH AMOUNTS ARE EXPECTED TODAY WITH HIGHEST
AMOUNTS OVER THE WEST HALF WHERE NRLY WINDS BRING ADDITIONAL LAKE
ENHANCEMENT AND UPSLOPE FLOW AS 850 MB TEMPS FALL INTO THE -6C TO
-10C RANGE.
TONIGHT...AS THE MID LEVEL LOW PIVOTS THROUGH NRN WI...LARGE SCALE
LIFT WILL PREVAIL ACROSS UPPER MI WITH CONTINUED LIGHT SNOWFALL
AMOUNTS. THE HEAVIER SNOWFAL WILL CONTINUE INTO THE NORTH NEAR LAKE
SUPERIOR WITH ADDITIONAL SNOWFALL TOTALS IN THE 3 TO 5 INCH RANGE.
HEADLINES...A WINTER WEATHER ADVISORY WAS ISSUED FOR THE NORTHERN
COUNTIES FOR THE MIXED PRECIPITATION THIS MORNING AND LONG DURATION
LIGHT TO MODERATE SNOW EVENT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 312 PM EST TUE DEC 16 2014
BY 00Z THURSDAY THE MAIN 500MB LOW WILL BE POSITIONED OVER BY...WITH
THE TROUGH LINGERING AT THE SFC AND ALOFT ACROSS THE UPPER GREAT
LAKES. A SIZABLE RIDGE WILL BE SET UP ACROSS S CENTRAL CANADA.
850MB TEMPS HOVERING IN THE -6 TO -8C RANGE AND FAVORABLE NNE WINDS
WILL KEEP SOME LIGHT LAKE EFFECT SNOW SHOWERS LINGERING ACROSS N
CENTRAL UPPER MI WEDNESDAY NIGHT. NOT EXPECTING MUCH IN THE WAY OF
ACCUMULATIONS GIVEN THE BORDERLINE TEMPERATURES ALOFT...AND LIMITED
MOISTURE THAT LOOKS TO BE STUCK AT OR BELOW 900MB. THE DGZ IS STILL
WAY UP AROUND 600MB...IN CLEAR AIR. EXPECT LOW CLOUDS TO LINGER INTO
THURSDAY MORNING.
OTHERWISE DRY AIR WILL RETURN FOR THE ENTIRE CWA FOR THURSDAY
THROUGH SATURDAY NIGHT...WITH SFC HIGH PRESSURE SETTLING IN FROM THE
NW BEFORE SLOWLY EXITING TO SE CANADA AND THE NEW ENGLAND STATES
SATURDAY. THE 500MB HIGH WILL SHIFT ACROSS N ONTARIO ON THURSDAY AND
CENTRAL QUEBEC FRIDAY NIGHT. ON THE E SIDE OF THE HIGH A
SHORTWAVE/TROUGH WILL MOVE FROM THE QUEBEC/ONTARIO BORDER AT 18Z
THURSDAY TO FAR E UPPER MI OR FAR S ONTARIO AROUND DAYBREAK FRIDAY.
LITTLE MORE THAN ADDITIONAL CLOUD COVER IS EXPECTED. THE 16/00Z AND
12Z ECMWF WERE THE MOST AGGRESSIVE WITH THIS FEATURE...KEEPING IT
ACROSS FAR E UPPER MI INTO FRIDAY EVENING. 850MB TEMPS WILL LINGER
AROUND -6 TO -8C THROUGH SUNDAY...SO EXPECT SO HUGE SWINGS
TEMPERATURE WISE THROUGH THIS PERIOD.
A ELONGATED AND OVERALL WEAK TROUGH EXTENDING FROM CENTRAL CANADA
THROUGH THE S PLAINS STATES FRIDAY AFTERNOON WILL EDGE TOWARD THE
UPPER GREAT LAKES TO START OUT THE WEEKEND. WHILE SEVERAL SMALL
DISTURBANCES WILL NEAR THE AREA SATURDAY AFTERNOON...DRY WEATHER IS
STILL ANTICIPATED. THE NEXT GOOD CHANCE FOR WIDESPREAD PRECIP SHOULD
COME IN MONDAY INTO TUESDAY...AS THE THE NEXT SFC LOW OVER CENTRAL
CANADA AND THE N PLAINS MONDAY MORNING SHIFTS ACROSS MN MONDAY
NIGHT...AND ONTARIO/UPPER GREAT LAKES DURING THE DAY TUESDAY. AHEAD
OF THE LOW EXPECT WAA PRECIP. A CHANCE OF RAIN COULD CREEP INTO THE
E THIRD OF THE U.P. /MAINLY STAY ACROSS LAKE MI/.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1221 PM EST TUE DEC 16 2014
SNOW WILL CONTINUE AT ALL TAF SITES THROUGH THE FCST PERIOD WITH
IFR/LIFR CONDITIONS EXPECTED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 552 AM EST TUE DEC 16 2014
A TIGHTENING PRES GRADIENT BETWEEN LOW PRES OVER NRN IL LIFTING TO
THE NE AND HIGH PRES OVER MANITOBA INTO THE NRN PLAINS WILL RESULT
IN NORTH WINDS OF 20 TO 30 KNOTS WITH A FEW GALE FORCE GUSTS TO 35
KNOTS TODAY INTO THIS EVENING. AS HIGH PRES BUILDS INTO THE NRN
LAKES FROM WED INTO THU...WINDS WILL DIMINISH TO 20 KNOTS OR LESS.
HIGH PRESSURE WILL THEN DOMINATE INTO THE WEEKEND WITH WINDS
REMAINING BELOW 20 KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 7 PM EST WEDNESDAY FOR MIZ001-
003>006-084-085.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
WEDNESDAY FOR MIZ007.
WINTER STORM WARNING UNTIL 7 PM EST /6 PM CST/ WEDNESDAY FOR
MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1231 PM EST TUE DEC 16 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 321 AM EST TUE DEC 16 2014
LOW PRESSURE WILL MOVE ACROSS LOWER MICHIGAN TODAY SPREADING RAIN
SHOWERS AS IT GOES. COLDER AIR WILL WRAP INTO THE SYSTEM LATER THIS
EVENING AND THE RAIN WILL MIX WITH AND THEN CHANGE TO LIGHT SNOW.
THIS WILL BEGIN A PERIOD OF NEAR NORMAL TEMPERATURES...ALTHOUGH MUCH
COLDER THAN WHAT WE`VE SEEN LATELY...THAT WILL LAST THROUGH THE
WEEKEND. LIGHT LAKE EFFECT SNOW SHOWERS ARE POSSIBLE WEDNESDAY INTO
THURSDAY WITH LIGHT ACCUMULATIONS POSSIBLE MAINLY WEST OF US-131.
&&
.UPDATE...
ISSUED AT 839 AM EST TUE DEC 16 2014
FOG HAS BECOME DENSE OVER A GOOD PART OF SOUTHWEST LOWER MICHIGAN.
LOOKING AT THE LATEST RAP MODEL DATA...THE LOWEST VISIBILITIES ARE
WHERE THE WINDS ARE CALM...WHICH IS UNDER THE SURFACE LOW. THIS
AREA OF CALM WINDS SHIFTS TO THE EAST NORTHEAST OVER TIME AND BY
16Z IS OVER OUR NORTHEAST CWA....REED CITY TO CLAIR TO NEAR ALMA.
AFTER THAT IT IS GONE. SO I BELIEVE THE FOG AREA WILL PERSIST A
GOOD PART OF THE MORNING BUT ANY ONE LOCATION SHOULD HAVE ONLY 2
TO 3 HOURS OF LOW VISIBILITIES. GIVEN THE SHORT TIME WINDOW FOR
THIS FOG I AS THINKING NOT TO ISSUE A FOG ADVISORY AT THIS POINT.
WE HAVE ALREADY ISSUED A SPECIAL WEATHER STATEMENT ON THE FOG AND
WE WILL CALL THAT GOOD FOR NOW.
OTHERWISE THE ON GOING FORECAST IS GOOD...SHOWERS WILL CONTINUE
THROUGH THE DAY AND CHANGE TO SNOW SHOWERS OVERNIGHT.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 321 AM EST TUE DEC 16 2014
FORECAST CONCERNS DEAL WITH THE EVOLUTION OF THE LOW CURRENTLY
MOVING THROUGH NORTHWEST ILLINOIS.
REGIONAL RADAR AND IR LOOP SHOWS A WELL DEFINED LOW JUST CROSSING
THE MISSISSIPPI. LIGHT RAIN SHOWERS CONTINUE TO PIVOT NORTHWARD FROM
INDIANA AND WE/LL BE LOOKING AT SHOWERS THROUGHOUT THE DAY AS THE
LOW MOVES ACROSS LOWER MICHIGAN. HEAVY RAIN ISN/T ANTICIPATED.
HOWEVER...THERE HAS BEEN SOME LIGHTNING OVER SOUTHERN INDIANA.
MODELS SHOW SOME ELEVATED INSTABILITY DEVELOPING OVER FAR WESTERN
LAKE ERIE THIS MORNING BUT IT PROBABLY TOO FAR AWAY TO RESULT IN
THUNDER IN OUR CWA.
COLDER AIR WILL WRAP INTO THE SYSTEM TONIGHT AND TURN THE LINGERING
PCPN TO LIGHT SNOW SHOWERS. H8 TEMPS FALL TO -12C WEDNESDAY AND THIS
NORMALLY CREATES SUFFICIENT OVER-LAKE INSTABILITY TO GENERATE SNOW
SHOWERS. THE ISSUE THIS TIME THOUGH IS THE SHALLOW MOISTURE. THE
DGZ IS VERY SMALL AND RESIDES AT THE TOP OF THE SHALLOW MOISTURE
AROUND 4K FT. IT/S PROBABLY ENOUGH TO SEE SOME SNOW SHOWERS...AND
LIGHT ACCUMS WEST OF US-131 BUT NOT MUCH MORE THAN THAT. THE SHSN
WILL GRADUALLY DIMINISH WEDNESDAY NIGHT.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 321 AM EST TUE DEC 16 2014
MORE QUIET WEATHER IS IN STORE IN THE LONG TERM PERIOD AS THE SPLIT
FLOW ALOFT CONTINUES AND SURFACE HIGH PRESSURE DOMINATES. THE POLAR
JET STAYS WELL TO OUR NORTH AND THE SRN STREAM BRANCH REMAINS
SOUTH... SO STILL NO MAJOR WINTER SYSTEMS OR ARCTIC AIR IN OUR
FUTURE.
THE MAIN CONCERN WILL BE CLOUD COVER AS STRATUS/FOG/DRIZZLE COULD BE
AN ISSUE AGAIN UNDER THE SFC HIGH. FOR NOW WILL BE OPTIMISTIC WITH
PARTLY SUNNY WORDING BUT THIS COULD CHANGE IN LATER FORECASTS.
TEMPERATURES ARE FORECAST TO BE NEAR NORMAL WITH HIGHS IN THE LOWER
TO MID 30S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1231 PM EST TUE DEC 16 2014
THE ENTIRE AREA REMAINED UNDER IFR OR LIFR CONDITIONS AS OF 17Z.
EXPECT ONLY A SLOW IMPROVE IN THIS. COLDER AIR AND STRONGER WINDS
WILL ARRIVE EARLY THIS EVENING...AND ALONG WITH THESE FACTORS...
THE IFR SHOULD ALSO IMPROVE INTO THE EVENING. EXPECT THAT MOST OF
THE IFR WILL LIFT TO MVFR AROUND 06Z.
AS THE COLDER AIR CONTINUES TO POUR IN...LAKE EFFECT SNOW SHOWERS
SHOULD DEVELOP LATE TONIGHT/EARLY WEDNESDAY MORNING. THE MEAN LOW
LEVEL FLOW WILL BE 290-300 WHICH FAVORS AZO SEEING THE BEST CHANCE
OF SNOW SHOWERS WITH SOME IFR REDEVELOPING. MKG...GRR...AND BTL
MAY ALSO SEE SOME SNOW SHOWERS INTO WED MORNING.
&&
.MARINE...
ISSUED AT 321 AM EST TUE DEC 16 2014
WINDS WILL INCREASE AS THE LOW MOVES BY THIS AFTERNOON. ISSUED A SCA
TO COVER INCREASED WINDS AND WAVES FROM THIS AFTERNOON THROUGH
THURSDAY MORNING.
&&
.HYDROLOGY...
ISSUED AT 321 AM EST TUE DEC 16 2014
NO HYDRO ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL NOON EST THURSDAY FOR LMZ844>849.
&&
$$
UPDATE...WDM
SYNOPSIS...93
SHORT TERM...93
LONG TERM...MEADE
AVIATION...JK
HYDROLOGY...93
MARINE...93
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1222 PM EST TUE DEC 16 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 536 AM EST TUE DEC 16 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SRN STREAM SHRTWV/LOW OVER
NRN IL AND A NRN STREAM SHRTWV ACROSS NW ONTARIO INTO NW MN. AT THE
SFC...LOW PRES WAS LOCATED OVER NRN IL WITH A TROUGH TO THE NORTH
INTO ERN UPPER MI. 295K-300K ISENTROPIC LIFT AHEAD OF THE NRN IL LOW
HAS BROUGHT AN INCREASE IN PCPN COVERAGE/INTENSITY ACROSS CNTRL
UPPER MI WHILE 850-700 FGEN HAS SUPPORTED THE SNOW INTO WRN UPPER
MI. NRLY LOW LEVEL FLOW WITH THE TIGHTENING PRES GRADIENT BEHIND THE
TROUGH HAS BROUGHT COLDER AIR INTO WRN UPPER MI CHANGING THE RAIN TO
SNOW AT CMX/IWD/LNL. EVEN THROUGH TEMPS HAVE ALSO FALLEN BELOW 32F
AT KMQT...THE CIRCULATION AROUND THE SRN STREAM LOW HAS MAINTAINED
AN ELEVATED WARM LAYER (AROUND 850 MB FROM 1C TO 3C) OVER CENTRAL
UPPER MI. EVEN WITH AIR TEMPS FALLING BELOW FREEZING...THE RECENT
WARM CONDITIONS HAVE LIMITED GLAZE POTENTIAL AS MOST SURFACES HAVE
NOT COOLED OFF AS FAST.
TODAY...AS THE SRN STREAM SHRTWV LIFTS TO THE NW THE NRN STREAM
SHRTWV WILL BECOME THE DOMINANT FEATURE LATE TODAY INTO TONIGHT.
EXPECT THAT THE LINGERING WARM LAYER WILL SUPPORT A BRIEF PERIOD OF
LIGHT FREEZING RAIN OR SLEET THROUGH AROUND 14Z. THE BEST
CHANCE FOR ANY ICING WOULD BE OVER THE HIGHER TERRAIN WHERE TEMPS
HAVE ALREADY FALLEN OFF BELOW FREEZING. OTHERWISE...THE RAIN SNOW
CHANGE OVER IS EXPECTED TO MOVE INTO THE ERN CWA BY AFTERNOON WITH
ALL SNOW AT ERY AFTER 21Z. THE NRN STREAM SHRTWV WITH INCREASING
700-500 MB QVECTOR CONV WILL SUPPORT LIGHT TO MODERATE SNOW ACROSS
UPPER MI TODAY. 1 TO 4 INCH AMOUNTS ARE EXPECTED TODAY WITH HIGHEST
AMOUNTS OVER THE WEST HALF WHERE NRLY WINDS BRING ADDITIONAL LAKE
ENHANCEMENT AND UPSLOPE FLOW AS 850 MB TEMPS FALL INTO THE -6C TO
-10C RANGE.
TONIGHT...AS THE MID LEVEL LOW PIVOTS THROUGH NRN WI...LARGE SCALE
LIFT WILL PREVAIL ACROSS UPPER MI WITH CONTINUED LIGHT SNOWFALL
AMOUNTS. THE HEAVIER SNOWFAL WILL CONTINUE INTO THE NORTH NEAR LAKE
SUPERIOR WITH ADDITIONAL SNOWFALL TOTALS IN THE 3 TO 5 INCH RANGE.
HEADLINES...A WINTER WEATHER ADVISORY WAS ISSUED FOR THE NORTHERN
COUNTIES FOR THE MIXED PRECIPITATION THIS MORNING AND LONG DURATION
LIGHT TO MODERATE SNOW EVENT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 330 AM EST TUE DEC 16 2014
THE UPPER LOW WILL BE OVER THE GREAT LAKES REGION AT 12Z
WEDNESDAY...WHILE THE 1006MB SURFACE LOW IS LOCATED OVER FAR
SOUTHEAST ONTARIO. A MID LEVEL TROUGH WILL BE STRETCHING WEST
ACROSS UPPER MICHIGAN AND WILL BE THE PRIMARY FOCUS FOR THE LIGHT
TO OCCASIONALLY MODERATE SNOW OVER MUCH OF UPPER MICHIGAN. THE
STRONGEST SNOW SHOWERS WILL BE OCCURRING OVER THE WESTERN AND NORTH
CENTRAL U.P. WHERE NORTH-NORTHWEST WINDS AND 850MB TEMPS AROUND
-14C WILL LEAD TO LAKE AND TERRAIN ENHANCEMENT. THESE FAVORABLE
CONDITIONS WILL REMAIN FOR THE MORNING HOURS...BUT THEN THE MID
LEVEL TROUGH WILL DROP SOUTH THROUGH UPPER MICHIGAN WEDNESDAY
AFTERNOON...LEADING TO WINDS SHIFTING TO THE NORTH-NORTHEAST AND
BRINGING WARMER 850MB AIR OVER THE AREA. THUS...SHOULD SEE THE
INTENSITY OF THE LAKE ENHANCEMENT DIMINISHING THROUGH THE AFTERNOON
AND INTO THE EVENING HOURS. IT WILL LIKELY LINGER THE LONGEST OVER
THE NORTH CENTRAL DUE TO THE FAVORABLE WIND DIRECTION. WITH MUCH OF
THE FORCING BELOW THE DGZ...WOULD EXPECT THE SNOW RATIOS FOR MUCH OF
THE AREA TO BE IN THE 12-15 TO 1 RANGE. THE ONE AREA WHERE VALUES
COULD BE A LITTLE HIGHER WOULD BE OVER THE WEST...WHERE THE LOW
LEVEL TEMPERATURES ARE A LITTLE COLDER AND PUTTING MORE OF THE CLOUD
IN THE DGZ. BUT EVEN THEN...A LOT OF THE LAKE ENHANCED FORCING IS AT
OR BELOW THE DGZ...WHICH WOULD SUPPORT RIMING OF ANY DENDRITES AND
IN TURN RATIOS IN THE 15-17 TO ONE RANGE. ALL IN ALL...ADDITIONAL
SNOWFALL AMOUNTS ON WEDNESDAY WILL BE IN THE 1-3 INCH
RANGE...HIGHEST IN THE TERRAIN/LAKE ENHANCED AREA OF NORTH CENTRAL
UPPER MICHIGAN.
WITH THE DRIER/WARMER AIR QUICKLY DIVE INTO THE REGION WEDNESDAY
NIGHT...WILL BRING AN END TO THE SNOW SHOWERS FROM NORTH TO SOUTH
THROUGH THE NIGHT. THIS TRANSITION IS SEVERAL HOURS FASTER THAN
SHOWN 24HRS AGO IN THE MODELS AND HAVE SHOWN THAT FASTER END IN THE
POPS. THAT WARMER/DRIER AIR IS ASSOCIATED WITH AN UPPER RIDGE AND
SURFACE HIGH SHIFTING OVER THE UPPER GREAT LAKES REGION. THESE
FEATURES WILL REMAIN IN PLACE THROUGH AT LEAST FRIDAY. THERE ARE
SOME HINTS OF MOISTURE AROUND 925MB BEING TRAPPED BELOW THE
SUBSIDENCE INVERSION ON THURSDAY. WILL HOLD ONTO MOSTLY CLOUDY SKIES
IN THE MORNING IN THE NORTH-NORTHEAST WIND FAVORED AREAS AND THEN
TRANSITION TO PARTLY CLOUDY IN THE AFTERNOON AS THE SFC-925MB
DELTA-T VALUES BECOME MORE MARGINAL.
MODELS CONTINUE TO DIFFER WITH THE EVOLUTION OF BOTH
UPSTREAM/DOWNSTREAM FEATURES WHICH LEADS TO A LITTLE LOWER
CONFIDENCE IN THE WEEKEND FORECAST. THE FIRST FEATURE THAT THEY
DIFFER ON IS A SHORTWAVE PULLING OUT OF THE SOUTHERN PLAINS AND OFF
THE MID ATLANTIC COAST. THE 12Z GEM/ECMWF DEVELOP A STRONGER LOW
WITH A MUCH MORE AMPLIFIED TROUGH...WHILE THE 00Z GFS IS MUCH WEAKER
WITH THE LOW AND FLATTER WITH THE WAVE. LOOKING AT THE ENSEMBLE
MEANS/MEMBERS...THE 12Z ECMWF MEMBERS ARE REMARKABLY CONSISTENT IN
THE EVOLUTION OF THE LOW OFF THE MID ATLANTIC STATES. BUT WHERE
THINGS DIFFER IS WITH THE HANDLING OF THE NEXT WEAK SHORTWAVE MOVING
THROUGH THE NORTHERN STREAM FLOW SATURDAY INTO SUNDAY. WHILE THE 12Z
GEM/ECMWF OPERATIONAL RUNS HOLD ONTO AN UPPER RIDGE OVER THE UPPER
MISSISSIPPI VALLEY DURING THIS TIME...THE ENSEMBLE MEANS MORE
CLOSELY RESEMBLE THE GFS IN THE IDEA OF A WEAK UPPER TROUGH MOVING
THROUGH THE UPPER MISSISSIPPI VALLEY AND THEN THE UPPER GREAT LAKES
THIS WEEKEND. BASED OFF THE 12Z ENSEMBLE MEANS AND THE 00Z
GEM/ECMWF OPERATIONAL RUNS COMING IN MORE IN LINE WITH THAT
IDEA...WILL FOLLOW THAT FOR THIS FORECAST. BUT EVEN WITH THAT WEAK
UPPER TROUGH MOVING THROUGH...THE SURFACE HIGH WILL BE PERSISTENT
AND SHOULD LEAD TO DRY CONDITIONS. 850MB TEMPS LOOK TO BE AROUND
-6C...WHICH IS EVEN MARGINAL FOR LAKE EFFECT CLOUDS IF THERE WAS
ENOUGH MOISTURE PRESENT...SO WILL GO WITH A DRY FORECAST AND PARTLY
CLOUDY SKIES ON SATURDAY AND MOSTLY CLOUDY ON SUNDAY. HIGHS THURSDAY
WILL START OUT NEAR NORMAL THEN SLOWLY WARM TO SLIGHTLY ABOVE NORMAL
VALUES (UPPER 20S AND LOWER 30S) FOR THE WEEKEND.
HEADING INTO NEXT WEEK...ECMWF/GEM/GFS ENSEMBLE MEANS HAVE BEEN
CONSISTENT FOR THE LAST SEVERAL DAYS TO A WEEK ON AN UPPER TROUGH
DROPPING SOUTHEAST FROM THE GULF OF ALASKA AND INTO THE NORTHERN
CONUS. THIS WILL LEAD TO A COOLER PERIOD AROUND CHRISTMAS AND
LIKELY REMAINING FOR THE END OF DECEMBER. ALTHOUGH IT IS STILL 8-9
DAYS OUT...THE CONSISTENCY IN THE ENSEMBLE MODELS ON THIS IDEA
IS WORTH MENTIONING. THEY CONTINUE TO SHOW A CANADIAN LOW TO DROP
THROUGH ONTARIO OR THE UPPER GREAT LAKES REGION ON THE 24TH OR
25TH. WHILE SNOW AMOUNTS ARE UNFORECASTABLE AT THIS TIME...AT
LEAST LIGHT SNOW IS EXPECTED DURING THAT BUSY HOLIDAY TRAVEL PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1221 PM EST TUE DEC 16 2014
SNOW WILL CONTINUE AT ALL TAF SITES THROUGH THE FCST PERIOD WITH
IFR/LIFR CONDITIONS EXPECTED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 552 AM EST TUE DEC 16 2014
A TIGHTENING PRES GRADIENT BETWEEN LOW PRES OVER NRN IL LIFTING TO
THE NE AND HIGH PRES OVER MANITOBA INTO THE NRN PLAINS WILL RESULT
IN NORTH WINDS OF 20 TO 30 KNOTS WITH A FEW GALE FORCE GUSTS TO 35
KNOTS TODAY INTO THIS EVENING. AS HIGH PRES BUILDS INTO THE NRN
LAKES FROM WED INTO THU...WINDS WILL DIMINISH TO 20 KNOTS OR LESS.
HIGH PRESSURE WILL THEN DOMINATE INTO THE WEEKEND WITH WINDS
REMAINING BELOW 20 KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ WEDNESDAY FOR
MIZ001>006-009-084-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
320 PM CST Tue Dec 16 2014
.SHORT TERM: (Through Friday Afternoon)
Issued at 320 PM CST Tue Dec 16 2014
(Tonight)
Deep cyclonic flow and cold air advection in the wake of yesterday`s
storm system kept diurnal temperature rises minimal today. Solid
shield of stratus yielded an occasional period of drizzle or
flurry, but nothing measurable was observed.
Cloud trends for tonight are uncertain. An extensive area of stratus
was located upstream, and northwest winds near 925mb remain
favorable for continued advection of these clouds into our area. On
the other hand, a hole was located in the cloud deck over western
IA, and if this area does not fill in, then skies should start to
clear over the Columbia and St. Louis areas between 23-02z. RAP
plots of increasing condensation pressure deficits between 975-900mb
tonight along with BUFKIT soundings which depict drying aloft both
support the idea of dissipating stratus/stratocu this evening,
although mid/high clouds will be increasing later tonight regardless
of what happens with the stratus/stratocu. However, BUFKIT profiles
also show a fair amount of subsidence above the low cloud layer,
which may act to trap moisture below the inversion and keep the
clouds in place. Partial clearing appears more likely over central
MO than elsewhere. Winds should remain around 10 kts for most of the
night.
CVKING/Kanofsky
(Wednesday - Friday)
Deep trof of low pressure currently coming onshore along the west
coast with our eyes tracking a pair of circulations that will bring
two chances of precipitation to the area the next seven days.
The first circulation will come ashore along the Baja tonight and
lift northeast across the southwest CONUS and southern Plains on
Wednesday. Warm advection will ramp up across the area Wednesday
night with light snow expected to rapidly develop and move into the
area from the southwest. Models continue to "moisten" the forecast
with higher QPF noted. Have increased POP and expected snowfall
amounts with up to two inches now possible across central Missouri
and the eastern Ozarks and an inch into the western suburbs of the
St. Louis Metro Area. Unfortunately it appears that the snow will be
hitting the St. Louis area either right before or at rush hour
Thursday morning. Luckily, ground temperatures are relatively warm
and air temperatures should be in the upper 20s or lower 30s. The
hope is that impact on travel will be low with this event. Snow will
taper off during the morning hours on Thursday as the shortwave
lifts east of the area. Lingering low level moisture and rising
surface temperatures suggest drizzle will be possible in the
afternoon hours.
The second and more potent circulation of the two will dig even
further south across the Baja before lifting east/northeast across
the deep south on Friday. Meanwhile, a northern stream shortwave
will also be diving southeast across the Plains. Unfortunately for
the snow lovers these two systems don`t appear to fully phase until
they are east of the area. Some snow flurries or light snow will be
possible across the far southern CWA Friday afternoon.
CVKING
.LONG TERM: (Friday Night through Next Tuesday)
Issued at 320 PM CST Tue Dec 16 2014
Continuing with the late week system, models push the southern
system, which will be the main driver of pcpn, well to our south
with some interaction with a northern system still anticipated to
help bring perhaps some light pcpn well to the north into a good
part of our region for Friday night. PoPs remain low because of
concerns of measurability, with many locations perhaps tracing out
instead. Pcpn-types favor snow.
The northern system itself will not quite get thru the forecast area
until later on Saturday and maintained slight chances for that
reason.
Southerly flow at the low levels will then be seen for Sunday and
Monday, helping temps to at or above normal levels once again.
Heading towards the middle of next week, a longwave RIDGE will
attempt to re-establish itself over western North America in
imitation of the dominant pattern in November, with a strong
shortwave disturbance dropping down in NW flow and a developing
upper level TROF over the central CONUS. Look for increasing PoPs
for this period with temps beginning to drop back to below normal
once again.
Christmas could be pretty quiet across our region, taking a sneak
peak at the long range models. But it looks to only be a timing
issue, with one system leaving and another lurking about a day away,
so this could change very quickly given all of the typical timing
issues the models have this far out.
TES
&&
.AVIATION: (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 1112 AM CST Tue Dec 16 2014
The primary forecast question for this set of TAFs is whether the
stratus will end during the next 24 hours. On one hand, there`s an
extensive area of stratus located upstream as well as northwest
winds which will continue advecting the clouds into MO/IL. On the
other hand, there`s also a hole in the aforementioned cloud bank,
and RAP forecasts (CPD) as well as BUFKIT soundings show
additional drying, which suggests that existing clouds should
start to dissipate and that it will be difficult for new clouds to
develop even within cyclonic flow. On the other other hand, the
cig/vis trend viewer in AVNFPS is evenly split on whether clouds
usually persist through 12z or become less likely after 04-06z,
depending on what conditions look like at 21z and 00z. In short,
there is a surprisingly high amount of uncertainty with the cig
forecast. This set of TAFs splits the difference and keeps MVFR
ceilings in place through 06-08z, but it`s equally likely that
ceilings could improve earlier than forecast or persist later than
forecast.
Specifics for KSTL: It`s equally likely that MVFR stratus could
persist beyond 12z or depart earlier around 06z. There might also
be a brief break between 23z-02z, depending on what happens with
the hole in the clouds over IA which was noted on satellite
imagery at TAF issuance. Regardless of what happens with the MVFR
stratus, increasing mid and high level clouds are expected after
12z.
Kanofsky
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 27 36 30 36 / 0 0 60 60
Quincy 23 34 24 32 / 0 0 20 50
Columbia 23 36 29 36 / 0 5 80 60
Jefferson City 23 36 29 37 / 0 5 80 60
Salem 27 36 30 36 / 0 0 30 60
Farmington 26 38 29 36 / 0 5 80 60
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
257 PM CST Tue Dec 16 2014
.SHORT TERM...(This Evening through Thursday)
Issued at 251 PM CST TUE DEC 16 2014
Surface high pressure over Kansas will shift east into the area
tonight. As this occurs remaining stratus field will be shunted
eastward with just high clouds in its wake. With the light winds
temperatures will drop into the lower to middle 20s for lows.
Short wave energy will cross the Four Corners region Wednesday
morning and will emerge across the central Plains late in the
afternoon. As this happens, low level isentropic upglide will
develop across the southern Plains and will shift northeast into
our region starting later in the afternoon. The low levels of the
atmosphere will be very dry to start off with, but our confidence
is increasing that the dry air will be overcome sooner rather than
later. First off, we may get into a jet coupling situation which
would enhance mid/upper level lift. Additionally, there will be
some weak instability that spreads into the region from the west.
This may result in some weak convective potential.
With that being said, we have moved up the start time of
precipitation. We are expecting it to start across southwest
Missouri from mid to late afternoon and then spread northeast
across the remainder of the Missouri Ozarks Wednesday evening.
Precipitation type remains a tough call. As initial wet-bulbing
takes place, we are expecting a mixture of rain, snow, and sleet
from Wednesday afternoon into Wednesday evening. The weak
instability will also aid in sleet potential. We did consider a
mention of thunder, but we would like to see a bit more in the way
of MUCAPE.
As wet-bulbing diminishes, the rain/snow line should initially set
up across far southwestern Missouri Wednesday evening. This
rain/snow line will then shift north and east later Wednesday
evening and especially Thursday morning. At its furthest north and
east point, the rain/snow line should end up somewhere across
central Missouri Thursday afternoon. Not to be forgotten is an
expected loss of cloud ice from late Wednesday night into Thursday
morning. This should result in a transition to at least patchy
drizzle with the continued potential of embedded pockets of light
snow/rain.
As for accumulations, we have nudged up snow amounts into the 1-2"
range along and north of the Highway 60 corridor. Amounts across
far southern Missouri (especially in the southwest) will be held
down due to warmer temperatures/more rain. The highest amounts are
expected to occur in the Truman to Lake of the Ozarks region.
Another item we will be monitoring is freezing drizzle potential
late Wednesday night into Thursday morning as we lose the cloud
ice. The greatest prospects for any freezing drizzle would be
along and north of a Pittsburg, Kansas to Bolivar to West Plains
line. If this forecast holds, a Winter Weather Advisory may be
required for portions of the area.
.LONG TERM...(Thursday Night through Tuesday)
Issued at 251 PM CST TUE DEC 16 2014
Any significant precipitation should be well to our east Thursday
night, though widespread low clouds and drizzle are expected to
be in place across the region. This scenario will continue through
Friday morning as well, with widespread, shallow moisture across
the area. Precipitation type is a bit tricky, with surface
temperatures likely to be just above freezing, and cloud ice
rather intermittent in nature. This suggests a mix of drizzle,
rain and snow, and if surface temperatures do happen to drop below
freezing in a few locations, perhaps a bit of freezing drizzle. At
this point, however, any impacts look to be quite minor.
By Friday morning, a shortwave is expected to be traversing the
Red River valley and Arklatex region, with a surface low/inverted
trough along the Gulf coast. Model trends have been decidedly
south with this system over the last few days, and that continued
with this morning`s 12Z model runs. Right now it still looks like
the southern third or so of the CWA will see some light
precipitation, though if the system moves any further south, even
this chance may dwindle. Temperatures should be warm enough during
the day Friday to support a rain/snow mix, with any lingering
precipitation ending as all snow Friday night. At this time it
appears that precipitation will be light enough to preclude any
measurable accumulations.
Seasonable and generally dry conditions are expected for most of
the weekend, with highs Saturday and Sunday in the 40s. The next
workweek looks to begin with temperatures around normal, though an
Arctic front looks to be setting up to our northwest by the end of
the forecast period, suggesting cooler temperatures by the middle
of next week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1136 AM CST TUE DEC 16 2014
For the KSGF/KJLN/KBBG TAFS:
Main forecast concern is on cloud trends this afternoon and evening
and corresponding ceilings heights.
12Z KSGF sounding shows low level moisture in the 900mb-850mb layer.
Examinations of short term model trends indicates this layer to
slowly dry through the afternoon from west to east as surface high
pressure shifts eastward from Kansas. Visible satellite imagery
showing back edge of clouds into eastern Kansas. MVFR ceilings will
slowly rise at the taf sites before scattering out later this
afternoon. Of note is the 15Z RAP BUKFIT soundings are slower in
pushing this moisture out this afternoon. Based on latest
satellite trends feel RAP may be to slow. As high slides across
the terminals tonight into early Wednesday expect VFR conditions
with light winds. Mid level moisture begins to increase ahead of
the next wave between 15Z-18Z but any ceilings that develop will
be in the VFR range.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...Raberding/Schaumann
LONG TERM...Boxell
AVIATION...Raberding
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1148 AM CST Tue Dec 16 2014
.SHORT TERM: (Through Late This Afternoon)
Issued at 326 AM CST Tue Dec 16 2014
Surface low currently over Quad Cities and will continue to lift
northeast today away from forecast area. Some lingering light
rain/drizzle to persist in wrap around this morning, mainly along
and east of Mississippi River. Otherwise, sc deck to be very slow to
move out of region, as high RH at 925mb remains entrenched over
forecast area today. As for temperatures, colder air to filter in
with temps still dropping a little this morning before becoming
steady or rise a few degrees by the early afternoon hours.
Byrd
.LONG TERM: (Tonight through Monday)
Issued at 326 AM CST Tue Dec 16 2014
It will remain mostly cloudy tonight with lows in the 20s. On
Wednesday we remain under surface ridge with partly cloudy skies and
highs in the mid 30s to low 40s.
Then the forecast for Wednesday night through Thursday is still
tricky to pin down. Surface ridge moves off to the east with upper
trof developing over southwestern US. Will see pieces of energy
eject out of trof and track through forecast area Wednesday night
and Thursday. We will remain in cold air so any precipitation that
does develop with these shortwaves will be in the form of light snow
for most of the area. QPF amounts will be on the light side with
highest amounts over southern sections of our forecast area. Could
see a few tenths of snowfall with highest amounts south of a
Columbia to Fredericktown line.
Beyond that, extended models still have differing solutions on
system that will remain south of forecast area Friday through
Saturday. GFS is a bit further north then ECMWF. For now will not
make major changes to pops through this period. As for pcpn type,
will cold air in place, should be all light snow.
Byrd
&&
.AVIATION: (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 1112 AM CST Tue Dec 16 2014
The primary forecast question for this set of TAFs is whether the
stratus will end during the next 24 hours. On one hand, there`s an
extensive area of stratus located upstream as well as northwest
winds which will continue advecting the clouds into MO/IL. On the
other hand, there`s also a hole in the aforementioned cloud bank,
and RAP forecasts (CPD) as well as BUFKIT soundings show
additional drying, which suggests that existing clouds should
start to dissipate and that it will be difficult for new clouds to
develop even within cyclonic flow. On the other other hand, the
cig/vis trend viewer in AVNFPS is evenly split on whether clouds
usually persist through 12z or become less likely after 04-06z,
depending on what conditions look like at 21z and 00z. In short,
there is a surprisingly high amount of uncertainty with the cig
forecast. This set of TAFs splits the difference and keeps MVFR
ceilings in place through 06-08z, but it`s equally likely that
ceilings could improve earlier than forecast or persist later than
forecast.
Specifics for KSTL: It`s equally likely that MVFR stratus could
persist beyond 12z or depart earlier around 06z. There might also
be a brief break between 23z-02z, depending on what happens with
the hole in the clouds over IA which was noted on satellite
imagery at TAF issuance. Regardless of what happens with the MVFR
stratus, increasing mid and high level clouds are expected after
12z.
Kanofsky
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1136 AM CST Tue Dec 16 2014
.SHORT TERM...(Today and Tonight)
Issued at 330 AM CST TUE DEC 16 2014
A stacked low pressure system continued to make its way toward
the Great Lakes region this morning. Accompanying deep cyclonic
pattern was resulting in a an expansive stratus field from the
Ozarks north into the Canadian provinces. Some patchy drizzle or
sprinkles noted across the region this morning and this will
continue mainly across central Missouri through the early morning
hours. Clouds will linger most of the day with gradual clearing
from the west this afternoon into tonight.
.LONG TERM...(Wednesday through Monday)
Issued at 330 AM CST TUE DEC 16 2014
An active progressive pattern over the next several days will
bring the potential of a couple of chances of light winter
precipitation events.
Seasonably cool and tranquil can be expected during the day Wednesday
as surface high pressure builds across the area in the wake of the
exiting low pressure system. However the break in active weather
will be brief as a shortwave trough tracks from southern California
into the southern Plains by Wednesday night.
Theta-e advection within the 850-700 mb layer and isentropic ascent
will strengthen Wednesday evening as moisture advects northward
resulting in an increasing coverage of precipitation. Lift could
be further enhanced by a ribbon of mid level frontogenetical forcing.
Expect light precipitation to develop as early as late Wednesday afternoon
across far southwestern Missouri then overspread the area Wednesday
evening.
Top down winter precipitation method and progged thermal profiles
suggest that precipitation will be a mix of rain and snow across
far southern Missouri and extreme southeastern Kansas and
primarily all snow across the remainder of the area generally
north of Highway 60 Wednesday night. Surface temperatures will
settle to near the freezing mark across much the area.
Snow accumulations Wednesday night will be light with amounts
ranging from a trace up to an inch expected at this time. While
accumulations will be light there is the potential for travel
impacts Wednesday night into the Thursday morning commute.
Temperatures will rise above freezing Thursday while we lose cloud
ice. The result will be a transition Thursday to patchy light rain
and drizzle. Will have to monitor for the potential of patchy
freezing drizzle Thursday night.
The next more pronounced shortwave trough will track across Texas
and the lower Mississippi River Valley Friday and Saturday with a
developing surface low along the Gulf coast. The precipitation
shield associated with this system will brush southern Missouri
Friday and Friday night. Precipitation during the day Friday will
be primarily rain with some potential of a rain/snow mix. The best
chance of precipitation will be across south central Missouri
Friday night. Expect precipitation to transition to primarily snow
Friday night with the best potential of minor accumulations across
south central Missouri or southeast of a Branson to Salem line.
Overall confidence has increased that at least portions of the
Missouri Ozarks and extreme southeastern Kansas we will have a
couple of minor winter precipitation events Wednesday night again
later Friday. It is important to note that while accumulations if
any will be light there is the potential that travel could be
impacted Wednesday night into the Thursday morning commute and
again Friday night. The placement and accumulations of snow will
be refined with time as new model data is received. Please
monitor the latest forecast.
A seasonably cold and drier weather pattern will return this
weekend as the region comes under the influence of a more
northwesterly flow.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1136 AM CST TUE DEC 16 2014
For the KSGF/KJLN/KBBG TAFS:
Main forecast concern is on cloud trends this afternoon and evening
and corresponding ceilings heights.
12Z KSGF sounding shows low level moisture in the 900mb-850mb layer.
Examinations of short term model trends indicates this layer to
slowly dry through the afternoon from west to east as surface high
pressure shifts eastward from Kansas. Visible satellite imagery
showing back edge of clouds into eastern Kansas. MVFR ceilings will
slowly rise at the taf sites before scattering out later this
afternoon. Of note is the 15Z RAP BUKFIT soundings are slower in
pushing this moisture out this afternoon. Based on latest
satellite trends feel RAP may be to slow. As high slides across
the terminals tonight into early Wednesday expect VFR conditions
with light winds. Mid level moisture begins to increase ahead of
the next wave between 15Z-18Z but any ceilings that develop will
be in the VFR range.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...Foster
LONG TERM...Foster
AVIATION...Raberding
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1144 AM CST TUE DEC 16 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CST TUE DEC 16 2014
WITH LITTLE TO NO RISK OF PRECIPITATION DURING THESE NEXT 24
HOURS...THE MAIN FORECAST CHALLENGE CENTERS AROUND
TEMPERATURES/SKY COVER...AND THE OBVIOUS AFFECT ONE HAS ON THE
OTHER...ALONG WITH ANY INFLUENCE ON TEMPS FROM SNOW COVER IN
NORTHERN/WESTERN COUNTIES.
STARTING OFF WITH THE HERE AND NOW AS OF 0900Z/3AM...ITS
CERTAINLY BEEN A MUCH QUIETER NIGHT THAN THE PRECEDING ONE...AS
ANY MEASURABLE PRECIP ASSOCIATED WITH THE DEPARTING LOW PRESSURE
SYSTEM IS NOW WELL-EAST INTO EASTERN IA. IN THE MID AND UPPER
LEVELS...WATER VAPOR SATELLITE AND SHORT TERM MODEL DATA CLEARLY
DEPICT THE CENTER OF THE CLOSED 500 MILLIBAR LOW OVER NORTHERN
IL...WHILE UPSTREAM FROM IT...THE LEADING EDGE OF A BROAD
SHORTWAVE RIDGE AND ASSOCIATED HEIGHT RISES IS STARTING TO
OVERSPREAD THE LOCAL AREA...WITH THE RIDGE AXIS GENERALLY ALIGNED
NORTH-SOUTH THROUGH THE ROCKIES. FARTHER WEST...THE NEXT BROAD
TROUGH IS IN THE PROCESS OF COMING ONSHORE THE WEST COAST...WHICH
WILL PROVIDE PLENTY OF CHALLENGES LOCALLY IN THE DAYS 2-4 PERIOD
AS COVERED IN THE LONG TERM SECTION BELOW. AT THE
SURFACE...CERTAINLY THE BIG STORY OVERNIGHT HAS BEEN CONTINUED
FAIRLY STRONG NORTHWEST WINDS...ALTHOUGH THEY ARE ON A SLOW-BUT-
STEADY DOWNWARD TREND AS THE PRESSURE GRADIENT STARTS TO RELAX IN
THE WAKE OF THE DEPARTING 1004MB LOW OVER NORTHERN IL...AND AS A
BROAD RIDGE AXIS CENTERED AT AROUND 1030MB OVER THE DAKOTAS/SOUTH
CENTRAL CANADA STARTS TO EXERT INCREASING INFLUENCE LOCALLY. AS OF
THIS TIME HOWEVER...SUSTAINED SPEEDS OF AT LEAST 20-25 MPH ARE
HANGING ON IN EASTERN ZONES WITH HIGHER GUSTS...AND MORE SO 15-20
MPH IN WESTERN ZONES. EARLIER IN THE NIGHT...THERE WERE LAW
ENFORCEMENT REPORTS OF SOME DICEY TRAVEL CONDITIONS DUE TO SLICK
ROADS/LIMITED BLOWING SNOW IN/NEAR THE FAR NORTHERN CWA COUNTIES
OF VALLEY/GREELEY...BUT FORTUNATELY THE DECREASING SPEEDS SHOULD
AT LEAST IMPROVE THIS SITUATION SLIGHTLY. ACTUALLY THE NUMBER ONE
VERY SHORT-TERM CHALLENGE IS SKY COVER...AS WHILE THE MAJORITY OF
THE CWA REMAINS UNDER A BROAD LOW STRATUS DECK AROUND 1500 FT
AGL...AN AREA OF CLEARING HAS RECENTLY BROKEN OUT OVER SOUTHWEST
COUNTIES. TEMP-WISE...AS SUSPECTED 24 HOURS THE COMBO OF CLOUDS
AND/OR BRISK BREEZES IS HOLDING UP THINGS FAIRLY WELL...AND
ALTHOUGH SOME DROPS COULD YET OCCUR AROUND SUNRISE...THINK THE
MAJORITY OF THE CWA SHOULD HOLD UP NO COLDER THAN THE 17-20 RANGE.
LOOKING FORWARD INTO THE DAYTIME FORECAST AND STARTING WITH THE
MID-UPPER LEVEL SCENE...THE AFOREMENTIONED BROAD RIDGE AXIS
OVERSPREADS THE CENTRAL PLAINS BUT FLATTENS A BIT AS IT DOES SO.
AT THE SURFACE...CERTAINLY THE MOST NOTICEABLE CHANGE FROM MONDAY
WILL BE THE DECREASING NORTHWESTERLY WINDS...AS THE PRESSURE
GRADIENT CONTINUES EASING UP AS THE SOUTHERN EDGE OF THE RIDGE
AXIS CENTERED TO THE NORTH CONTINUES PUSHING SOUTHWARD INTO THE
CENTRAL PLAINS IN THE WAKE OF THE DEPARTING LOW THAT REACHES THE
LAKE HURON AREA BY SUNSET. SPEED-WISE...BY MID-DAY SUSTAINED
SPEEDS SHOULD AVERAGE ONLY AROUND 15 MPH IN EASTERN ZONES...AND NO
MORE THAN 10-15 MPH IN WESTERN COUNTIES...AND BY NIGHTFALL THE
ENTIRE CWA SHOULD BE DOWN TO ONLY 5-10 MPH. AS MENTIONED...SKY
COVER/TEMPS ARE REALLY THE FORECAST CHALLENGE OF THE DAY. MODELS
SUCH AS THE 06Z NAM CLEARLY HOLD ONTO PLENTIFUL LOW LEVEL CLOUD
COVER THROUGH THE ENTIRE DAY WITHIN ROUGHLY THE NORTHEAST 1/2 OF
THE CWA...BUT DO SHOW AT LEAST SEVERAL HOURS OF MOSTLY SUNNY-
PARTLY CLOUDY POTENTIAL OVER MUCH OF THE SOUTHWESTERN 1/2.
ALTHOUGH THE LATEST HRRR LOW LEVEL SKY COVER PRODUCT SPORTS A
SIMILAR THEME...IT SUGGESTS THAT SOME OF THE CLEARING THAT OCCURS
COULD FILL BACK IN AS MORE CLOUDS ADVECT IN FROM THE NORTH-
NORTHWEST. EVEN IF PARTS OF THE CWA DO ENJOY APPRECIABLE CLEARING
AND WELCOMED SUNSHINE THROUGH MUCH OF THE DAY...ESPECIALLY THE
LATER AFTERNOON HOURS SHOULD BRING A GRADUAL INCREASE IN MID-HIGH
CLOUDS STREAMING IN FROM THE WEST IN ASSOCIATION WITH A WEAK/LOW
AMPLITUDE SHORTWAVE TROUGH WELL OUT AHEAD OF THE LARGER WESTERN
TROUGH. SO IN SUMMARY...GENERALLY EXPECT MOSTLY CLOUDY SKIES
NORTHEAST 1/2 TODAY...AND MOSTLY SUNNY-PARTLY CLOUDY
SOUTHWEST ESPECIALLY KS ZONES...BUT SOME VARIATION FROM THIS IS
LIKELY AS WELL. OBVIOUSLY THIS TRICKY SKY COVER WILL WORK IN
CONCERT WITH THE GENERALLY 1-3 INCHES OF SNOW COVER IN PLACE OVER
SEVERAL NORTHERN/WESTERN COUNTIES TO MAKE HIGH TEMPS A BIT
CHALLENGING AS WELL. WITH RAW MET/MAV GUIDANCE LOOKING A BIT TOO
COOL ESPECIALLY IN SOUTHERN ZONES...OPTED TO MAKE ONLY MINOR
TWEAKS TO PREVIOUS FORECAST BY TRYING TO STRIKE SOME KIND OF
BALANCE BETWEEN VARIABLE SNOW COVER AND SKY COVER. THE NET
RESULT...ALTHOUGH NOT OVERLY CONFIDENT...YIELDS ONLY MID-UPPER 20S
WITHIN MANY NORTHERN/WESTERN NEB COUNTIES...MAINLY LOW 30S IN
EASTERN/SOUTHERN NEB ZONES...AND GENERALLY MID 30S IN KS ZONES.
TURNING TO THIS EVENING/TONIGHT...THE MID-UPPER LEVEL PICTURE
FEATURES THE AFOREMENTIONED/RATHER SUBTLE LEAD SHORTWAVE
DISTURBANCE CROSSING OVER THE LOCAL AREA...WHILE MORE ENERGETIC
WAVES REMAIN WELL OFF TO THE WEST-SOUTHWEST. MEANWHILE AT THE
SURFACE...THE RIDGE AXIS WILL SLOWLY EDGE EASTWARD. ALTHOUGH WIND
SPEEDS SHOULD REMAIN LIGHT GENERALLY WELL-UNDER 10 MPH THROUGH THE
ENTIRE NIGHT...DIRECTION WILL GRADUALLY TRANSITION FROM NORTHERLY
TO EASTERLY. DESPITE THE FAIRLY WEAK NATURE OF THE PASSING
DISTURBANCE...MODEL RELATIVE HUMIDITY PROGS DEPICT A FAIRLY DECENT
COVERAGE OF MID-HIGH CLOUD COVER THROUGH THE NIGHT...AND HAVE THE
ENTIRE CWA IN PARTLY TO MOSTLY CLOUDY SKY COVER CATEGORY. WHILE
CONFIDENCE IS FAIRLY HIGH IN A PRECIP-FREE NIGHT (ESPECIALLY
MEASURABLE) AND THE OFFICIAL FORECAST REFLECTS SUCH...WOULD NOT BE
TOTALLY SURPRISED TO SEE A WEST-EAST ORIENTED BAND OF FLURRIES
TRY TO GET GOING LATE IN THE NIGHT MAINLY OVER/NEAR THE NORTHERN
CWA IN RESPONSE TO SOME FAIRLY MODEST ISENTROPIC LIFT/FRONTOGENESIS
FOCUSED IN THE ENTRANCE REGION OF A DEPARTING UPPER JET STREAK.
DESPITE THE LIGHT BREEZES...THE EXPECTED FAIRLY HIGH SKY COVER
SHOULD KEEP TEMPS FROM REALLY FALLING OFF...AND AS A RESULT KEPT
LOW TEMPS GENERALLY 2-4 DEGREES ABOVE A 00Z MET/MAV GUIDANCE
BLEND...AIMING MOST OF THE CWA INTO THE 15-20 RANGE...EXCEPT FOR
COLDER READINGS AROUND 10 FAR NORTH. LASTLY...DESPITE FAIRLY HIGH
VALUES OF FORECAST LOW-LEVEL RELATIVE HUMIDITY...CONFIDENCE WAS
NOT SUFFICIENT ENOUGH IN FOG FORMATION TO INTRODUCE EVEN A PATCHY
MENTION FOR LATE TONIGHT...ALTHOUGH 03Z SREF/06Z NAM VISIBILITY
PROGS SUGGEST THAT MAYBE LOCALIZED POCKETS OF MAINLY THE FAR
WESTERN CWA COULD BEAR WATCHING FOR THIS...ESPECIALLY IF ENOUGH
SNOW MANAGES TO MELT TODAY TO ENHANCE LOW-LEVEL MOISTURE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 457 AM CST TUE DEC 16 2014
THE BIGGEST CHALLENGE CONTINUES TO BE DETERMINING CHANCES OF
PRECIPITATION...AS WELL AS POTENTIAL TYPE OF PRECIPITATION WEDNESDAY
NIGHT THROUGH THURSDAY NIGHT.
MODELS ARE COMING IN BETTER AGREEMENT WITH A LONGWAVE TROUGH OVER
THE GREAT BASIN EJECTING A LOW-AMPLITUDE WAVE INTO THE SOUTH CENTRAL
PLAINS. THIS WILL BE A FAIRLY QUICK HITTER...DROPPING SOME QUICK
LIGHT SNOW WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING...WITH
POTENTIALLY SOME LINGERING FLURRIES FOR THURSDAY AFTERNOON/NIGHT. AT
TIMES...IT APPEARS THAT WE COULD HAVE A LOSS OF SATURATION IN MID-
LEVELS. THIS IS GENERALLY LOWER THAN THE DENDRITIC GROWTH ZONE.
THERE IS NOT WIDESPREAD AGREEMENT WITH THIS. WAS THINKING ABOUT
STICKING IN POTENTIAL LIGHT FREEZING DRIZZLE FOR THURSDAY
NIGHT...BUT THE WAVE SHOULD BE FAR ENOUGH EAST THAT I HAVE DOUBTS
THAT MUCH OF ANY PRECIPITATION WILL FALL AT ALL. I STUCK IN A SLIGHT
CHANCE OF FLURRIES FOR THURSDAY AFTERNOON/NIGHT...AS THE NAM DOES
ADVERTISE SOME SPARSE NON-MEASURABLE PRECIPITATION...BUT THIS DOES
NOT LOOK LIKELY BY ANY MEANS.
I KEPT PRECIPITATION OUT OF FRIDAY AS THE MAIN WAVE IS TRENDING
FARTHER SOUTH...WITH THE ASSOCIATED ENERGY FAR TOO SOUTH TO GIVE US
A CHANCE OF PRECIPITATION.
THE FORECAST IS DRY FOR THE WEEKEND INTO MONDAY...HOWEVER
PROGRESSIVE WEST/NORTHWEST FLOW MAKES THINGS A BIT UNCERTAIN AS
SMALL WAVES AND PERTURBATIONS MAY NECESSITATE SOME CHANCES OF
PRECIPITATION DOWN THE ROAD...ESPECIALLY TOWARD MONDAY...DEPENDING
ON TIMING AND PLACEMENT OF WAVES/PERTURBATIONS.
THERE WILL BE A SLOW AND STEADY INCREASE OF TEMPERATURES DURING THE
LONG TERM FORECAST...YET REMAINING FAIRLY SEASONABLE.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1140 AM CST TUE DEC 16 2014
A SFC RIDGE OF HIGH PRESSURE WILL SLIDE EAST ACROSS THE
AREA...WHICH WILL RESULT IN DECREASING WINDS TODAY AND EVENTUALLY
LIGHT AND VARIABLE TO EVEN CALM WINDS BY THIS EVENING. A GENTLE
EAST SOUTHEAST BREEZY CAN THEN BE EXPECTED WEDNESDAY MORNING AFTER
THE RIDGE PASSES OFF TO OUR EAST. THE LOW CLOUDS WILL LIKELY HOLD
ON THROUGHOUT THE PERIOD...ALTHOUGH THERE MAY BE SOME BREAKS AT
TIMES. WILL GO WITH PERSISTENCE...WHICH IS SUPPORTED BY THE
FORECAST MODELS AND CALL FOR GENERALLY MVFR CEILINGS THROUGHOUT
THE TAF PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...HEINLEIN
AVIATION...WESELY
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
102 PM EST TUE DEC 16 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST THIS AFTERNOON AND MOVE
THROUGH THE AREA TONIGHT. HIGH PRESSURE WILL BUILD IN FROM THE
NORTHWEST WEDNESDAY THROUGH FRIDAY. DEVELOPING LOW PRESSURE WILL
MOVE ALONG THE COAST SATURDAY INTO SUNDAY. HIGH PRESSURE IS
EXPECTED TO BUILD OVER THE AREA MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1 PM TUESDAY...BAND OF SHOWERS CONTINUES TO SLOWLY APPROACH
OUR WESTERN CWA AND LATEST 3KM HRRR CONTINUES TO HANDLE THE
PRECIPITATION QUITE WELL. BROKEN BAND OF LIGHT TO OCCASIONALLY
MODERATE SHOWERS WILL CROSS THE CWA FROM ROUGHLY 19Z TO ABOUT 04Z
TONIGHT BEFORE MOVING OFFSHORE. LOWER CLOUDS WILL ACCOMPANY THE
SHOWERS AS THE FILTERED SUNSHINE OF THE MORNING WILL BE REPLACED
BY LOWER OVERCAST. TEMPERATURES LIKEWISE WILL LIKELY FALL A FEW
DEGREES DURING THE LATE AFTERNOON HOURS. INSTABILITY IS VERY
LIMITED AND TO NOT EXPECT THUNDER AT THIS TIME.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
AS OF 330 AM TUESDAY...MODELS REMAIN IN FAIRLY CLOSE AGREEMENT WITH
SHRT WV TROF AND ASSCTD SFC COLD FRONT MOVING ACROSS AREA OVERNIGHT.
PER NEAR TERM DISCUSSION...MAIN THREAT OF PCPN WILL BE OVER ERN HALF
OF AREA EARLY EVENING WITH HIGHEST POPS AROUND 50%. PCPN WILL PUSH
OFF COAST BY AROUND MIDNIGHT WITH CLEARING SKIES OVERNIGHT.
MIN TEMPS LOW TO MID 40S INLAND AND AROUND 50 OUTER BANKS.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 325 AM TUE...LONG TERM PERIOD WILL FEATURE A FAIRLY ACTIVE
AND CHANGEABLE WEATHER PATTERN...WITH A SIGNIFICANT STORM SYSTEM
POSSIBLE FOR THE WEEKEND. SFC HIGH PRESSURE WILL BUILD INTO
EASTERN NC FROM THE W/NW WED THROUGH FRI. LOW LEVEL THICKNESS
VALUES AND SUNNY SKIES SUPPORT HIGHS 55-60DEG WED WITH LOW LEVEL
W/NW FLOW. LOW LEVEL THICKNESS VALUES SUPPORT HIGHS IN THE UPPER
40S/MID 50S FOR THU AND FRI WITH SHORTWAVE MOVING NORTH OF THE
AREA AND ZONAL FLOW ACROSS ENC.
A SIGNIFICANT SYSTEM MAY IMPACT THE REGION THIS WEEKEND. THE
PREVIOUS FAVORED ECMWF...NOW BEGINNING TO TREND SIMILAR TO THE
GFS...DEPICTING A WEAKER AND SLOWER SOLUTION. MODELS SHOW WEAK SFC
MOVING THROUGH MEXICO AND SOUTHERN TX THU NIGHT AND FRI... THEN
INTO THE DEEP SOUTH/NORTHERN GULF REGION SATURDAY...EVENTUALLY
INTENSIFYING OFF THE SE COAST LATE SAT INTO SUN NIGHT. THOUGH MUCH
UNCERTAINTY REMAINS WITH TRACK AND INTENSITY OF LOW...THERE WILL BE
THE POTENTIAL FOR HEAVY RAIN...STRONG WINDS...AND MINOR COASTAL
IMPACTS THIS WEEKEND...INCLUDING MINOR WATER LEVEL RISES AND ROUGH
SURF. STILL LOOKS LIKE THE FIRST PART OF THE WEEKEND WILL BE WET
AND CONTINUED LIKELY POPS...WITH MOISTURE TAPERING OFF LATE SUN.
AN ISOLATED CHANCE OF TSTMS STILL POSSIBLE SAT THOUGH VERY
DEPENDENT ON EVENTUAL TRACK OF LOW...WITH BEST CHANCE ALONG THE
COAST AND OFFSHORE.
BOTH GFS/ECMWF SHOW A SOUTHERN STREAM DEVELOPING EARLY NEXT WEEK
AHEAD OF THE UPPER TROUGH...AS THE WEEKEND SFC LOW LIFTS NE OFF
THE NEW ENGLAND COAST. BELOW NORMAL TEMPS EXPECTED FOR SUN/MON
WITH HIGHS IN THE UPPER 40S/LOW 50S AND OVERNIGHT LOWS IN THE 30S.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
SHORT TERM /THROUGH 12Z WEDNESDAY/...
AS OF 1235 PM TUESDAY...LOWER CEILINGS AND LIGHT SHOWERS CONTINUE
TO APPROACH THE CWA. HAVE INCLUDED A PERIOD FROM ROUGHLY 19Z
THROUGH ABOUT MIDNIGHT TONIGHT OF MVFR CEILINGS WITH SHOWERS IN
THE VICINITY. CONDITIONS SHOULD IMPROVE RAPIDLY AFTER MIDNIGHT
WITH VFR CONDITIONS PREVAILING THROUGH WEDNESDAY. SOUTHWEST WINDS
BECOME NORTHWEST AFTER MIDNIGHT AND CONTINUE THROUGH WEDNESDAY.
LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 325 AM TUE...PRED VFR CONDITIONS EXPECTED THROUGH MOST OF
THE PERIOD. THERE WILL BE THE POTENTIAL FOR WIDESPREAD SUB-VFR
CONDITIONS TO DEVELOP SATURDAY...AS LOW PRESSURE SYSTEM IS
EXPECTED TO IMPACT EASTERN NC.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1 PM TUESDAY...SOUTHEAST WINDS WILL GRADUALLY BECOME
SOUTHWEST AND INCREASE THIS AFTERNOON. ALREADY SEEING GUSTS TO 16
KNOTS AT CAPE LOOKOUT AND 18 KNOTS AT THE CAPE HATTERAS COAST
GUARD STATION. SEAS REMAIN AROUND 2 FEET. EXPECT TO SEE WIDESPREAD
WINDS OF 15 TO 20 KNOTS BY LATE IN THE DAY. ADJUSTED FCST SEAS
WITH LATEST NWPS...INDICATING PERIOD OF 6 FT HEIGHTS FOR OUTER
PORTIONS OF SRN AND CENTRAL WATERS TONIGHT.
LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 325 AM TUE...SFC HIGH PRESSURE WILL BUILD INTO THE REGION FROM
THE W/NW WED THROUGH FRI...RESULTING IN W/NWLY FLOW 10-20KT AND
SEAS 2-4FT. TRENDED WITH WAVEWATCH LATE WED THROUGH FRI...THINKING
THAT LOCAL NWPS IS STILL SLIGHTLY OVERDONE WITH THE OFFSHORE FLOW.
UNCERTAINTY INCREASES THIS WEEKEND WITH THE POTENTIAL FOR ANOTHER
COASTAL LOW DEVELOPING AND IMPACTING THE EASTERN NC WATERS.
PREVIOUS FAVORED MODEL ECMWF...NOW THE 00Z RUN COMING IN MORE
SIMILAR TO THE GFS...DEPICTING A SLIGHTLY WEAKER AND SLOWER SFC
LOW MOVING ALONG THE NC COAST SUN AND SUN NIGHT. CONFIDENCE
REMAINS LOW BUT THERE WILL BE THE POTENTIAL FOR STRONG WINDS TO
GALE FORCE AND HAZARDOUS SEAS THIS WEEKEND.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 5 AM EST
WEDNESDAY FOR AMZ152-154-156-158.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...CQD
AVIATION...CTC/CQD
MARINE...JBM/CTC/CQD
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
346 PM EST TUE DEC 16 2014
.SYNOPSIS...
AS LOW PRESSURE MOVES NORTHEAST THROUGH THE GREAT LAKES...A FEW
SHOWERS WILL CONTINUE TO BE POSSIBLE INTO THE OVERNIGHT HOURS.
COOLER CONDITIONS ARE EXPECTED THROUGH THE REST OF THE WEEK...WITH
GENERALLY DRY CONDITIONS. A CHANCE OF RAIN AND SNOW IS IN THE
FORECAST FOR SATURDAY...AS WEAK LOW PRESSURE APPROACHES THE REGION
FROM THE SOUTH.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
WITHIN A LUMBERING MID-LEVEL TROUGH...CURRENTLY CENTERED OVER THE
GREAT LAKES...TWO DISTINCT VORTICITY MAXIMA ARE GRADUALLY
PROGRESSING AHEAD. THE FIRST OF THESE IS MOVING ENE THROUGH THE
SOUTHERN GREAT LAKES...WITH ITS INFLUENCE BEING FELT ACROSS THE
OHIO VALLEY...AND THROUGHOUT THE NWS ILN FORECAST AREA.
THE DIURNAL CYCLE TODAY HAS BEEN STUNTED FROM ITS RATHER WARM
STARTING POINT...AS COLD ADVECTION ON WESTERLY FLOW HAS ALREADY
BEGUN. THOUGH THERE IS NO DISTINCT DIRECTIONAL WIND SHIFT TO
HELP PICK OUT A CHANGE IN AIR MASS...THE REST OF THE DAY WILL
SIMPLY FEATURE A CONTINUED GRADUAL CLOCKWISE TURNING IN SURFACE
WINDS...ALONG WITH STEADY DROPS IN TEMPERATURES AND DEWPOINTS. A
STRONGER PUSH OF COLD ADVECTION JUST OFF THE SURFACE APPEARS
LIKELY TO BEGIN AFTER 06Z...WHICH SHOULD HELP LEAD TO STEEPER
LAPSE RATES NEAR THE GROUND...AND CONTINUED OCCASIONAL WIND GUSTS
TO AROUND 20 KNOTS. THIS WILL ALSO LIKELY KEEP RH VALUES RATHER
HIGH AT AROUND 925MB-875MB...AND LOW LEVEL CLOUDS ARE NOT EXPECTED
TO BREAK BEFORE MORNING.
RADAR HAS FINALLY STARTED TO SHOW A DIMINISHING TREND IN COVERAGE
FOR RAIN SHOWERS...AND THIS TREND IS EXPECTED TO CONTINUE. LIFT
ASSOCIATED WITH THE MID-LEVEL TROUGH IS ALREADY BEGINNING TO
DIMINISH...AS THE AXIS IS CLEARING THE CWA TO THE EAST.
HOWEVER...WITH THE THICK LOW-LEVEL MOISTURE IN PLACE...THERE
APPEARS TO BE A CHANCE FOR SOME VERY LIGHT RAIN OR DRIZZLE TO
CONTINUE INTO THE OVERNIGHT HOURS. HRRR SIMULATED REFLECTIVITY
HAS...ON SEVERAL RUNS...REFUSED TO GO COMPLETELY DRY DURING THIS
PERIOD. FORTUNATELY...IT APPEARS MOST LIKELY THAT ANY
RAIN/DRIZZLE/MIST POTENTIAL WILL BE DIMINISHING BEFORE
TEMPERATURES DROP BELOW FREEZING. THE 15Z SREF IS VERY LOW ON
PROBABILITIES FOR VISIBILITY REDUCTIONS...WHICH MAKES SENSE GIVEN
THE EXPECTED WINDS...BUT ALSO LENDS SUPPORT TOWARD WIDESPREAD MIST
OR DRIZZLE BEING UNLIKELY. THE MOST LIKELY SCENARIO WILL BE FOR A
FEW PATCHES OF LIGHT RAIN OR DRIZZLE THROUGH THE FIRST HALF OF THE
OVERNIGHT...POSSIBLY INTO THE EARLY MORNING IN CENTRAL OHIO.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS LOW PRESSURE MOVES NORTHEAST OF THE OHIO VALLEY...THE PRESSURE
GRADIENT WILL GRADUALLY RELAX ON WEDNESDAY...BUT CONTINUED COOL
WESTERLY FLOW WILL FORCE TEMPERATURES TO REMAIN BELOW AVERAGE.
ALTHOUGH DRY CONDITIONS ARE EXPECTED...THE BIGGEST FORECAST
CHALLENGE FOR WEDNESDAY WILL BE WITH SKY CONDITIONS. AS HAS BEEN
THE CASE SEVERAL TIMES ALREADY THIS COOL SEASON...THE NAM12
SOLUTION FOR LOW-LEVEL MOISTURE HAS REMAINED MUCH THICKER THAN
OTHER MODELS (GFS/GEM/ECMWF). KEEPING THE BOUNDARY LAYER WELL
MIXED BELOW 3000 FEET THROUGH THURSDAY MORNING...THE NAM12
MAINTAINS A THICK LAYER OF TRAPPED MOISTURE BELOW AN INVERSION.
DESPITE WHAT APPEARS TO BE A CONSENSUS FROM THE OTHER MODELS...THE
NAM12 HAS SHOWN SUCCESS IN THESE SCENARIOS THANKS TO ITS
RESOLUTION IN THE VERTICAL...AND IT CURRENTLY APPEARS TO BE
VERIFYING WELL OVER MISSOURI (WHERE OTHER MODELS ARE ALREADY
SUGGESTING CLEARER CONDITIONS THAN OBSERVED). SKY GRIDS HAVE THUS
BEEN INCREASED ON WEDNESDAY AND INTO WEDNESDAY NIGHT...ALLOWING
FOR SOME BREAKS IN THE EVENING.
AT 500MB ON WEDNESDAY NIGHT...A NARROW RIDGE WILL EXTEND FROM THE
SOUTHERN STATES NORTHWEST INTO THE MIDDLE MISSISSIPPI VALLEY. AS A
WEAK SHORTWAVE MOVES OUT OF THE FOUR CORNERS AREA AND RUNS INTO
THE RIDGE...IT WILL WEAKEN FURTHER...EVENTUALLY WASHING OUT OVER
THE OHIO VALLEY ON THURSDAY. BEFORE THE SYSTEM DISSIPATES...IT
APPEARS THAT SOME WEAK ISENTROPIC LIFT WILL ALLOW FOR AN INCREASE
IN CLOUDS ON THURSDAY...MOVING FROM SOUTHWEST TO NORTHEAST ACROSS
THE OHIO VALLEY. A SLIGHT CHANCE OF PRECIPITATION (MAINLY SNOW)
WAS ALSO INCLUDED...AS MOST LOCATIONS ARE LIKELY TO REMAIN
DRY...BUT SOME LIGHT PRECIPITATION MAY MAKE IT DOWN. MOST OF THE
CLOUDS AND FORCING SHOULD REMAIN ABOVE 5000 FEET...WITH AN
EXTREMELY WEAK SURFACE PRESSURE PATTERN PROVIDING NO SUPPORT.
COLD ADVECTION ON THURSDAY WILL BE MUCH WEAKER WITH THE LIGHTER
FLOW...BUT WITH A RELATIVELY SMALL DIURNAL TEMPERATURE COMPONENT
EXPECTED...TEMPERATURES ON THURSDAY ARE EXPECTED TO REMAIN FAIRLY
SIMILAR TO VALUES ON WEDNESDAY.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH PRESSURE AND DRY CONDITIONS WILL START OUT THE LONG TERM
PERIOD. THE NEXT SYSTEM WILL BEGIN TO APPROACH THE AREA LATE FRIDAY
NIGHT AND INTO THE DAY ON SATURDAY BEFORE TAPERING OFF SATURDAY
NIGHT. PRECIPITATION WILL GENERALLY BE IN THE FORM OF LIGHT SNOW
ACROSS THE NW HALF OF THE FA. PRECIPITATION IS EXPECTED TO START
OFF AS SNOW ACROSS THE SE HALF OF THE FA HOWEVER SOME RAIN IS
EXPECTED TO MIX IN DURING THE DAY BEFORE TRANSITIONING BACK TO LIGHT
SNOW.
HIGH PRESSURE WILL THEN WORK BACK INTO THE AREA FOR SUNDAY AND
MONDAY. THE NEXT SYSTEM WILL BEGIN TO WORK INTO THE AREA FOR
TUESDAY. MODELS WERE IN SOMEWHAT DECENT AGREEMENT WITH THIS FEATURE
HOWEVER THE 12Z ECMWF SOLUTION IS NOW SLOWER AND MORE ROBUST. DID
NOT WANT TO JUMP ON THIS NEW SOLUTION QUITE YET AND WENT WITH MORE
OF A MODEL BLEND FOR TUESDAY. A MIX OF RAIN AND SNOW ARE EXPECTED
HOWEVER AS COLDER AIR BEGINS TO MOVE INTO THE AREA PRECIPITATION
LOOKS TO CHANGE OVER TO ALL SNOW SHOWERS DURING THE TUESDAY NIGHT
INTO WEDNESDAY TIME PERIOD.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
SURFACE LOW PRESSURE NEAR WESTERN LAKE ERIE EARLY THIS AFTERNOON
WILL LIFT SLOWLY EAST/NORTHEAST TO SE CANADA THROUGH THE TAF
PERIOD. ONE MORE PIECE OF UPPER LEVEL ENERGY IS EXPECTED TO ROTATE
EAST THROUGH THE TAF SITES THIS AFTERNOON. THIS WILL BRING A ROUND
OF VFR/MVFR SHOWERS ALONG WITH MVFR CEILINGS. FOR LATE THIS
AFTERNOON INTO THE EARLY MORNING HOURS...CEILINGS ARE EXPECTED TO
DROP INTO THE IFR CATEGORY FOR A PERIOD OF TIME AS CONSIDERABLE
MOISTURE IN THE LOW LEVELS CONTINUES TO WRAP AROUND DEPARTING LOW
PRESSURE. SOME MODELS SUGGEST THAT CEILING MAY LIFT ABOVE 1000
FEET BETWEEN 06Z AND 08Z BUT STILL REMAIN BELOW 2000 FEET.
ON WEDNESDAY...ANOTHER UPPER LEVEL DISTURBANCE IS EXPECTED TO
ROTATE EAST ACROSS THE GREAT LAKES. SURFACE HIGH PRESSURE TO OUR
NORTHWEST WILL BE SLOW TO BUILD IN. SOME MODELS SUGGEST THAT IT
MAY TAKE AWHILE FOR LOW LEVEL CLOUDS TO ERODE AND/OR SHIFT OFF TO
THE NORTHEAST...SO HAVE LIFTED CEILINGS ABOVE 2000 FEET AT THE 30
HOUR KCVG TAF BY 18Z BUT KEPT CEILINGS BROKEN.
OUTLOOK...MVFR CEILINGS MAY LINGER INTO WEDNESDAY EVENING. MVFR
CEILINGS AND VISIBILITIES POSSIBLE FRIDAY NIGHT INTO SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...NOVAK
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS PORTLAND OR
231 PM PST TUE DEC 16 2014
.SYNOPSIS...THERE WILL BE A BREAK IN RAIN THIS AFTERNOON BEFORE RAIN
ASSOCIATED WITH A LOW WEST OF THE CENTRAL OREGON COAST...MOVES SOUTH
TO NORTH THIS EVENING THROUGH WEDNESDAY MORNING. SHOWERS WILL
PRIMARILY BE OVER THE HIGHER TERRAIN. AN UPPER TROUGH WILL MAINTAIN A
CHANCE FOR SHOWERS THROUGH WEDNESDAY EVENING. A MORE ORGANIZED FRONT
WILL BRING GUSTY WINDS AND LARGE SURF TO THE COAST...WITH RAIN
SPREADING INLAND THURSDAY NIGHT AND FRIDAY. RISING SNOW LEVELS WILL
LIMIT SNOW TO THE HIGHEST PEAKS...BUT COLDER AIR BEHIND THE FRONT MAY
RESULT IN SOME SNOW SHOWERS FOR THE CASCADES PASSES FRIDAY EVENING
AND SATURDAY. A WARMER AND MOISTER WEATHER IS EXPECTED THIS WEEKEND.
&&
.SHORT TERM...TONIGHT THROUGH FRIDAY...SHOWERS HAVE PRETTY MUCH ENDED
OVER THE PORTLAND FORECAST AREA EARLY THIS AFTERNOON...EXCEPT FOR
VERY INFREQUENT ISOLATED SHOWER OVER THE SW WASHINGTON CASCADES.
SATELLITE IMAGERY SHOWS A SURFACE LOW AROUND 150 MILES WEST OF THE
SOUTHERN OREGON COAST...NEAR 42N 127W. THE HIGHER RESOLUTION
MODELS...HRRR AND RAP INITIALIZE BEST WITH THE LOW AND FORECAST RAIN
MOVING NORTH INTO LANE COUNTY SLIGHTLY EARLIER THAN THE OTHER MODELS.
HAVE TRENDED TOWARDS THIS EARLIER ARRIVAL...BUT ONLY HAVE FAIR
CONFIDENCE THAT THE TIMING WILL PAN OUT. ANY RAIN LATE THIS AFTERNOON
SHOULD BE FAIRLY LIGHT AND REMAIN WEST OF THE SOUTH AND CENTRAL
WILLAMETTE VALLEY.
THE LOW WILL MOVE CLOSER TO THE SOUTHERN OREGON COAST LATE THIS
AFTERNOON AND EVENING THEN MOVE ONTO THE CENTRAL OREGON COAST AS AN
UPPER TROUGH LATE TONIGHT...WITH SHOWERS MAINLY OVER THE HIGHER
TERRAIN THROUGH WEDNESDAY MORNING. SOME CLEARING EARLY WED MORNING
MAY RESULT IN SHALLOW FOG AND LOW CLOUDS IN SOME OF THE INTERIOR
VALLEYS...MAINLY SOUTH OF SALEM.
EASTERLY WINDS HAVE HELD ON TODAY WITH A TROUTDALE TO DALLES PRESSURE
GRADIENT HOLDING AROUND 5 MB. THIS GRADIENT SHOULD TIGHTEN A LITTLE
THIS EVENING AS THE LOW MOVES CLOSER TO THE COAST AND MAINTAIN GUSTS
AROUND 30 MPH THROUGH THE WESTERN COLUMBIA RIVER GORGE.
SHOWERS WILL CONTINUE WEDNESDAY...MAINLY FOR THE HIGHER TERRAIN AS
THE PARENT UPPER LEVEL TROUGH MOVES OVER THE PACIFIC NW. SHOWERS
SHOULD END OVERNIGHT AS AN UPPER RIDGE BUILDS OVER THE AREA AND
EXPECT THAT CLEARING SKIES AND LIGHT WINDS WILL LEAD TO SHALLOW FOG
FOR THE INTERIOR VALLEYS EARLY THURSDAY MORNING. MOST OF THURSDAY
WILL BE DRY WITH AN INCREASE OF MID AN HIGH LEVEL CLOUDS IN THE
AFTERNOON.
MODELS ARE IN GOOD AGREEMENT THAT A WELL ORGANIZED FRONT WILL BRING
GUSTY WINDS TO THE COAST THURSDAY EVENING WITH RAIN SPREADING INLAND
THURSDAY NIGHT AND FRIDAY. PRECIPITABLE WATER IS EXPECTED TO BE NEAR
AN INCH AND AN APPROACHING JET STREAK SHOULD PROVIDE GOOD LIFT AND
EXPECT THE HIGHEST RAINFALL TOTALS OF 0.75 TO 1 INCH ACROSS THE
COAST AND COAST RANGE THURSDAY NIGHT THROUGH FRIDAY MORNING. OTHER
AREAS SHOULD SEE BETWEEN 0.4 AND 0.60 INCH OF RAIN. SNOW LEVELS
SHOULD REMAIN ABOVE 5000 FEET DURING THE PEAK RAIN PERIOD...BUT LOWER
TO NEAR OR BELOW THE CASCADE PASSES BEHIND THE FRONT FRIDAY
AFTERNOON.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...A BROAD RIDGE OF HIGH
PRESSURE OVER THE WESTERN U.S. FLATTENS AS A STRONG LOW PRESSURE
SYSTEM OVER THE GULF OF ALASKA MOVES INLAND TO OUR NORTH. AS THIS
TROUGH MOVES ON SHORE SATURDAY...THE ASSOCIATED COLD FRONT MOVES
ONSHORE AND STALLS EAST-TO-WEST ACROSS NORTHWEST OREGON AND
SOUTHWEST WASHINGTON. THIS PUTS OUR AREA IN THE PATH OF RAIN
STARTING SATURDAY THROUGH MONDAY. SOME UNCERTAINTY EXISTS IN WHERE
THIS BOUNDARY WILL SET UP...WHICH WILL DETERMINE HOW MUCH RAINFALL
WE WILL GET. ON TUESDAY...GEFS ENSEMBLE SPAGHETTI PLOTS GET MESSY
AND SIGNIFICANT DIFFERENCES START TO SHOW UP BETWEEN THE GFS AND
ECMWF...DECREASING CONFIDENCE ON HOW THE REST OF THE WEEK WILL SHAPE
UP. AS OF NOW...THE MOST COMMON SOLUTION IS THAT HIGH PRESSURE
RIDGING WILL START TO BUILD BACK OVER THE WESTERN U.S. WHICH
SUGGESTS DRIER WEATHER STARTING TUESDAY...THOUGH UNCERTAINTY IS VERY
HIGH. -MCCOY
&&
.AVIATION...MAINLY VFR CONDITIONS ACROSS THE FORECAST AREA THIS
AFTERNOON...WITH A COUPLE NOTABLE EXCEPTIONS. IFR/LIFR CIGS
DEVELOPED THIS MORNING IN THE WILLAMETTE VALLEY KSLE SOUTHWARD...
AND HAVE LINGERED ALL DAY DUE TO LIGHT N-NE FLOW JAMMING THE LOW
CLOUDS AGAINST THE SOUTH END OF THE WILLAMETTE VALLEY. KSLE
APPEARS TO BE ON THE NORTHERN FRINGE OF THESE LOW CLOUDS...AND
WILL LIKELY REMAIN SO THROUGH THIS EVENING. CIGS WILL PROBABLY
DROP BACK DOWN TO NEAR THE DECK IN THESE AREAS TONIGHT AS -RA
DEVELOPS WITH OUR NEXT FRONTAL SYSTEM AND MOISTENS UP THE LOW
LEVEL AIR MASS.
ALSO EASTERLY UPSLOPE FLOW CAUSING MOUNTAIN OBSCURATIONS ALONG
THE EAST SLOPES AND CREST OF THE CASCADES...AND WILL LIKELY
CONTINUE TO DO SO OVERNIGHT TONIGHT.
WILL SEE AREAS -RA SPREAD NORTHWARD ACROSS MUCH OF THE FORECAST
AREA LATER TONIGHT...BUT IT APPEARS CIGS WILL GENERALLY REMAIN VFR
UNLESS OTHERWISE STATED ABOVE.WEAGLE
KPDX AND APPROACHES...VFR CIGS LIKELY REMAIN AT OR ABOVE 5 K FT
THROUGH THIS EVENING. SOME -RA IS POSSIBLE LATER TONIGHT AS
MOISTURE ASSOCIATED WITH AN OCCLUDED FRONT SPREADS NORTHWARD.
HOWEVER IT APPEARS CIGS SHOULD REMAIN VFR. LIGHT TO MODERATE
EASTERLY SFC WINDS THROUGH THIS EVENING. WEAGLE
&&
.MARINE...VISIBLE SATELLITE IMAGERY SHOWS A WELL-DEFINED LOW
PRESSURE SYSTEM ABOUT 150 NM WEST OF CRESCENT CITY CA. THIS SYSTEM
APPEARS TO HAVE REACHED ITS MAXIMUM STRENGTH WITH A CENTRAL
PRESSURE AROUND 995 MB. FORECAST MODELS APPEAR TO HAVE GENERALLY
CAUGHT UP WITH THE STRENGTH OF THIS SYSTEM AFTER LAGGING BEHIND
EARLIER TODAY. THE LOW WILL DRIFT E-NE TONIGHT...PUSHING INTO WRN
OREGON BY WED. IT APPEARS E-NE WINDS CURLING AROUND THIS LOW WILL
BE ENOUGH TO PUSH GUSTS TO 25 KT IN OUR FAR SW WATERS...SO ISSUED
A SCA FOR WINDS IN THIS AREA THIS EVENING. AS THE LOW WEAKENS...
WINDS ASSOCIATED WITH THIS SYSTEM SHOULD WEAKEN AS WELL.
THE NEXT RELATIVELY STRONG FRONTAL SYSTEM IS BEGINNING TO TAKE
SHAPE BETWEEN 160W-170W...AND MAY PRODUCE GALES FOR OUR WATERS AS
IT MOVES ONSHORE LATER THU/EARLY FRI. THERE IS A GOOD POTENTIAL
FOR COASTAL JET FORMATION WHICH WOULD ENHANCE WINDS JUST AHEAD OF
THE FRONT WITH GUSTS TO 45 KT POSSIBLE NEAR THE COAST THU NIGHT.
AFTER COORDINATION WITH WFO SEATTLE...DECIDED CONFIDENCE WAS HIGH
ENOUGH TO WARRANT A GALE WATCH FOR THIS SYSTEM. 12Z ECMWF/GFS SHOW
THIS SYSTEM TAKING A NEAR-IDEAL TRACK AND SPEED FOR DYNAMIC
FETCH...AND THIS SHOWS IN THE WAVE MODELS. ENP GUIDANCE SUGGESTS
A SOLID 17-21 FT SWELL WITH A DOMINANT PERIOD OF 16-20 SECONDS
FOLLOWS THE FRONT...PROBABLY ENOUGH TO WARRANT A HIGH SURF
ADVISORY FRIDAY. WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...GALE WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR WINDS FROM 6 PM THIS EVENING TO
MIDNIGHT PST TONIGHT FOR WATERS FROM CASCADE HEAD TO
FLORENCE OR FROM 10 TO 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 11 PM
THIS EVENING TO 3 AM PST WEDNESDAY.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 9 AM TO
5 PM PST WEDNESDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS MEDFORD OR
216 PM PST TUE DEC 16 2014
.DISCUSSION...PRECIPITATION AHEAD OF A SURFACE LOW NEAR 42N/128W IS ALREADY
REACHING CAPETOWN CALIFORNIA AND IS MOVING NORTH TO NORTHEAST. THE
RAP IS DOING FAIRLY WELL IN INITIALIZING THE POSITION OF THE LOW AND
QPF FIELDS THIS AFTERNOON AND HAVE LEANED TOWARDS THIS SOLUTION FOR
THIS EVENING. WINDS HAVE INCREASED AHEAD OF THE LOW IN THE SHASTA
VALLEY AND WILL LAST THROUGH THE NIGHT, BUT DO NOT EXPECT THEM TO
REACH ADVISORY CRITERIA. THE RAP SHOWS THE PRECIP FIELD BREAKING UP
INTO TWO PARTS THIS EVENING. ONE PART WILL MOVE NORTH OVER THE
MARINE WATERS, THE OTHER WILL CONTINUE TO PUSH EAST INTO NORTHERN
CAL AND INTO THE MOUNT SHASTA REGION. THE PARAMETERS ON THE NAM WITH
RESPECT TO SNOW NEAR AND AT MOUNT SHASTA HAVE CHANGED LITTLE FROM
THE PREVIOUS RUN. IT STILL LOOKS FAVORABLE FOR HEAVIER PRECIPITATION
TO DEVELOP LATER THIS EVENING AND TONIGHT DUE TO UPSLOPE FLOW AND
850 MB TEMPERATURES NEAR 0C. IN ADDITION 700MB FLOW IS FROM THE
SOUTH BETWEEN 40-50 KTS. THE MAIN QUESTION WILL BE HOW MUCH. CURRENT
THINKING IS THAT WE`LL HAVE A RAIN WET SNOW MIX TO START THIS
EVENING WITH MODEL SOUNDINGS RIGHT AT THE CUSP BETWEEN RAIN AND
SNOW. PRECIPITATION WILL INCREASE TONIGHT FORCING THE SNOW LEVEL
DOWN LOW ENOUGH TO GET INTO MOUNT SHASTA. SNOW RATIONS WILL BE LOW,
BUT QPF VALUES SUGGEST WE COULD PICK UP AT LEAST 3 INCHES OR MORE
NEAR THE INTERSTATE, ESPECIALLY BETWEEN MOUNT SHASTA AND DUNSMUIR.
IT`S POSSIBLE HIGHWAY 89 COULD GET UP TO 6 INCHES OR MORE BY
DAYBREAK WEDNESDAY.
THE UPPER TROUGH MOVES THROUGH WEDNESDAY MORNING AND THE UPPER FLOW
WILL BECOME WESTERLY WHICH WILL LIMIT THE AMOUNT OF PRECIPITATION
IN THE MOUNT SHASTA REGION. ELSEWHERE VALLEY RAIN AND MOUNTAIN
SNOW SHOWERS WILL LINGER, BUT WERE NOT EXPECTING ANYTHING
NOTEWORTHY WITH MINIMAL IMPACT ON PASSES. SOME LEFTOVER SHOWERS
WILL LINGER INTO WEDNESDAY EVENING, THEN END OVERNIGHT AS
SHORTWAVE RIDGING BUILDS INTO THE AREA. 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 COULD GET CLOSE TO GALES.
THIS FRONT WILL PUSH INLAND THURSDAY NIGHT WITH PRECIPITATION
SPREADING OVER MUCH OF THE FORECAST AREA. THE HEAVIEST AMOUNTS WILL
BE ALONG THE COAST RANGE, COASTAL MOUNTAINS AND CASCADES. RIGHT NOW
SNOW LEVELS WILL START OUT HIGH THURSDAY EVENING, 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. RIGHT NOW, IT LOOKS LIKE CRATER LAKE
COULD PICK UP AT LEAST 6 INCHES OR MORE...A FEW INCHES OVER
SISKIYOU SUMMIT AND HIGHWAY 140. KEEP IN MIND THE DETAILS ON THIS
WILL CHANGE, SO STAY TUNED FOR THE LATEST UPDATES, ESPECIALLY FOR
ANYONE PLANING ON TRAVELING THE WEEKEND BEFORE CHRISTMAS.
-PETRUCELLI
LONG-TERM FORECAST...SATURDAY THROUGH TUESDAY. A BROAD LONG WAVE
RIDGE WILL BUILD INTO THE WEST COAST SATURDAY AND SUNDAY...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
THOUGH.
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 AGAIN 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 START OFF BETWEEN 4000 AND 5000 FEET
SATURDAY...BUT WILL RISE TO ABOVE 7000 FEET SATURDAY NIGHT INTO
SUNDAY AND REMAIN ABOVE ALL BUT THE HIGHEST TERRAIN UNTIL IT LOWERS
SLIGHTLY TUESDAY NIGHT. SO...THE HEAVIEST SNOWS WILL OCCUR WITH THE
SATURDAY SYSTEM.
&&
.AVIATION...BASED ON THE 16/18Z TAF CYCLE...VFR CONDITIONS WILL
PREVAIL INITIALLY ACROSS THE MEDFORD CWA. AREAS OF MVFR CIGS IN
PRECIPITATION WILL DEVELOP THIS AFTERNOON ALONG THE SOUTH COAST
RANGE AND MOST OF SISKIYOU COUNTY WITH HIGHER TERRAIN BECOMING
OBSCURED. AREAS OF IFR CIGS/VSBYS IN LOW CLOUDS AND FOG WILL
DEVELOP OVER THE WESTERN VALLEYS LATE TONIGHT AND PERSIST THROUGH
MID-MORNING WEDNESDAY.
&&
.MARINE...UPDATED 900 AM PST TUE DEC 16 2014...HEAVY WEST
SWELL WILL GRADUALLY SUBSIDE TODAY. SURFACE LOW PRESSURE CENTERED
NEAR 130 WEST EARLY THIS MORNING WILL APPROACH AND THEN MOVE ONTO
THE NORTHERN CALIFORNIA COAST TONIGHT. THIS WILL RESULT IN
INCREASING SOUTH WINDS AND BUILDING SEAS...ESPECIALLY SOUTH OF
CAPE BLANCO AND BEYOND 10NM OFFSHORE...WHERE GALE FORCE WINDS ARE
EXPECTED. WINDS WILL DIMINISH AS THE LOW MOVES BY THIS EVENING
THROUGH WEDNESDAY MORNING. THURSDAY INTO FRIDAY A STRONGER FRONT
WILL PUSH THROUGH WITH ANOTHER ROUND OF STRONG SOUTH WINDS...RAIN...
AND STEEP SEAS. VERY HEAVY WEST SWELL AROUND 20 FEET WITH A DOMINANT
PERIOD OF 19 SECONDS WILL ARRIVE ON FRIDAY.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 10 AM PST
WEDNESDAY FOR CAZ082-083-282-284.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 1 AM PST WEDNESDAY FOR
PZZ356-370.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST WEDNESDAY
FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM PST WEDNESDAY FOR
PZZ376.
GALE WARNING UNTIL 7 PM PST THIS EVENING FOR PZZ376.
HAZARDOUS SEAS WARNING UNTIL 7 PM PST THIS EVENING FOR PZZ376.
$$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
954 AM PST TUE DEC 16 2014
.SYNOPSIS...SHOWERS WILL DECREASE TODAY AS A WEAK UPPER TROUGH MOVES
NORTHEAST OF THE AREA. AFTER A BRIEF BREAK IN RAIN THIS AFTERNOON AND
EVENING ANOTHER UPPER TROUGH WILL BRING PERIODS OF RAIN...MAINLY TO
THE HIGHER ELEVATIONS TONIGHT AND WEDNESDAY. A MORE ORGANIZED FRONT
WILL BRING GUSTY WINDS AND LARGE SURF TO THE COAST...AND WIDESPREAD
RAIN THURSDAY NIGHT AND FRIDAY. RISING SNOW LEVELS AND SUBTROPICAL
MOISTURE SPILLING INTO THE REGION WILL LIKELY BRING RAIN TO ALL BUT
THE HIGHEST PEAKS. COLDER AIR WILL MOVE IN BEHIND THE FRONT WITH SOME
SNOW SHOWERS FOR THE CASCADES PASSES POSSIBLE FRIDAY NIGHT AND
SATURDAY BEFORE ANOTHER WARMER SYSTEM RAISES THE SNOW LEVELS AGAIN
LATE IN THE WEEKEND
&&
.UPDATE...SHOWERS ARE QUICKLY MOVING NORTH OVER NW OREGON AND SW
WASHINGTON THIS MORNING AS A LOW IS SPINNING UP OFFSHORE THE NORTHERN
CALIFORNIA COAST. HAVE REMOVED POPS SOUTH OF SALEM FOR THE REST OF
THIS MORNING AND THE EARLY AFTERNOON...AND HAVE REDUCED POPS NORTH OF
SALEM WITH ISOLATED SHOWERS FOR THE INTERIOR VALLEYS AND SCATTERED
SHOWERS FOR THE HIGHER TERRAIN. SATELLITE AND SURFACE OBSERVATIONS
SHOWS PATCHY FOG IN THE INTERIOR VALLEYS OF SOUTHERN LANE
COUNTY...NEAR EUGENE...AND HAVE ADDED FOG IN THE FORECAST FOR THE
REMAINDER OF THE MORNING.
HAVE CONTINUED THE NORTHWARD TREND OF DISAPPEARING RAIN FOR THIS
AFTERNOON AND EVENING BY REMOVING POPS TO THE NORTH. HOWEVER...THE
POPS AT THIS TIME ARE REINTRODUCED TO THE SOUTH DUE TO THE LOW
SHIFTING INLAND. THE SNOW LEVEL IS AROUND 4000 FT THIS MORNING WITH
WEB CAMS SUGGESTING 1 TO 2 INCHES OF ACCUMULATING SNOW FOR THE CASCADE
PASSES OVERNIGHT.
SATELLITE IMAGERY IS SHOWING CYCLOGENESIS AROUND 200 MILES OFFSHORE OF
THE CALIFORNIA/OREGON BORDER THIS MORNING. THIS LOW MAY BE SLIGHTLY
DEEPER THAN THE PREVIOUS MODELS SUGGESTED AND EXPECT THE EASTERLY
SURFACE PRESSURE GRADIENT TO HANG ON A LITTLE LONGER. THE EASTERLY
WINDS WILL WEAKEN A LITTLE THIS MORNING AND AFTERNOON THAN INCREASE
AGAIN LATE THIS AFTERNOON AND EVENING. THE GRADIENT WILL NOT BE
PARTICULARLY STRONG WITH MODELS FORECASTING A TROUTDALE TO DALLES
GRADIENT AROUND 8 MB...BUT THIS IS STRONGER THAN THE PREVIOUS
FORECAST AND HAVE INCREASED THE EASTERLY WINDS FOR TONIGHT THROUGH
WED MORNING...MAINLY THROUGH THE COLUMBIA RIVER GORGE AND NORTHERN
AREAS. THE DEEPER LOW WILL ALSO RESULT IN A TIGHTER SOUTHERLY
GRADIENT WED AFTERNOON AS THE LOW MOVES INLAND AND HAVE INCREASED THE
SOUTHERLY WINDS FOR THE WILLAMETTE VALLEY A TAD.
THE UPPER TROUGH ASSOCIATED WITH THE FRONT/LOW OFFSHORE IS SPLITTING
AND RAIN FOR TONIGHT AND WEDNESDAY ACROSS NW OREGON AND SW WASHINGTON
IS NOT VERY IMPRESSIVE. MOST OF THE RAIN WILL BE FAR SOUTH OR FAR
NORTH OF US...BUT A PART OF THE UPPER TROUGH WILL APPROACH TONIGHT
AND MOVE OVER WEDNESDAY...MAINTAINING A CHANCE OF SHOWERS. THINK
MOST OF THESE SHOWERS WILL BE OVER THE HIGHER TERRAIN WITH THE
INTERIOR VALLEYS NOT SEEING MUCH RAIN. TJ
.PREVIOUS SHORT TERM...TODAY THROUGH FRIDAY...LIGHT RAIN PERSISTS
TODAY AS A WEAK FRONTAL SYSTEM CONTINUES TO PUSH EAST OF THE FORECAST
AREA EARLY THIS MORNING. SURFACE OBSERVATIONS ARE REPORTING BETWEEN
0.01-0.05" OF RAIN IN THE PAST 6 HOURS...EXCEPT FOR ALMOST 0.10" OF
PRECIP OVER THE COAST RANGE. THE NEXT FRONTAL SYSTEM CAN BE SEEN IN
INFRARED SATELLITE IMAGERY JUST OFF THE OREGON/CALIFORNIA COASTLINE
THIS MORNING. TEMPERATURES HAVE LOWERED TO 32-35 DEG F IN THE UPPER
PORTIONS OF THE HOOD RIVER VALLEY...WHERE SOME LIGHT SNOW
ACCUMULATIONS UP TO AN INCH OR SO ARE POSSIBLE THROUGH THIS MORNING.
EVEN WITH OFFSHORE FLOW PERSISTING...MODELS CONTINUE TO SHOW THE
EASTERLY GRADIENT STARTING TO SLACK OFF TODAY. GRADIENTS FURTHER
WEAKEN THROUGH LATE WED...AS HIGH PRESSURE SLOWLY WEAKENS EAST OF THE
CASCADES.
MODELS REMAIN CONSISTENT IN SHOWING MUCH OF THE ENERGY ASSOCIATED
WITH THIS NEXT LOW PRES SYSTEM HEADING SOUTH INTO NORTHERN CALIFORNIA
LATER TODAY. AS A RESULT...OFFSHORE LOW LEVEL FLOW BECOMES REINFORCED
WHILE FLOW ALOFT TURNS A BIT MORE SOUTHERLY...ALLOWING SHOWER
ACTIVITY TO DIMINISH BY THIS AFTERNOON. SHOWERS MAY LINGER LONGER
ALONG THE CENTRAL OREGON COAST THOUGH. MOISTURE BEGINS TO SPREAD
ACROSS THE AREA AS THE CENTER OF THE LOW PRES DRIFTS TOWARDS THE
OREGON/CALIFORNIA BORDER OVERNIGHT TONIGHT INTO WEDNESDAY MORNING.
THE UPPER LEVEL TROUGH AXIS MOVES INLAND MIDDAY WEDNESDAY AND
WEDNESDAY NIGHT... WHICH SHOULD BRING ANOTHER ROUND OF PRECIP TO THE
AREA. BRIEF UPPER LEVEL RIDGING DEVELOPS FOR THURSDAY...BUT A WARM
FRONT AHEAD OF THE NEXT ORGANIZED FRONTAL BAND COULD BRING A THREAT
FOR PRECIP BY EARLY THURSDAY AFTERNOON. EAST WINDS MAY PICK UP AGAIN
THROUGH THE GORGE AS THIS SYSTEM APPROACHES THE COAST. THIS STRONG
FRONTAL SYSTEM PUSHES INTO THE PACIFIC NORTHWEST FRIDAY...BRINGING A
DECENT BATCH OF PRECIP TO THE AREA AS WELL AS GUSTY SOUTH WINDS FOR
THE COAST.
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...FRIDAY NIGHT
THROUGH MONDAY...A COLD AIR UNSTABLE AIRMASS WILL FOLLOW A STRONG
FRONTAL SYSTEM AND KEEP SHOWERS GOING INTO FRIDAY NIGHT. SNOW LEVELS
SHOULD LOWER TO NEAR 4000 FT ON SO ACCUMULATING SNOW APPEARS LIKELY
FOR AT LEAST THE HIGHER PASSES. AN ADDITIONAL SHORTWAVE TROUGH OR TWO
COULD ENHANCE SHOWER ACTIVITY EARLY IN THE WEEKEND AND BRING MUCH
NEEDED SNOW TO THE HIGHER CASCADES.
MODELS GENERALLY AGREE SNOW LEVELS WILL RISE LATE IN THE WEEKEND AS A
WARM FRONT SLIDES INTO THE REGION. STRONG ZONAL FLOW WILL FOCUS
PERSISTENT AND HEAVIER RAIN ACROSS SOUTHWEST BRITISH COLUMBIA AND
WESTERN WASHINGTON LATE IN THE WEEKEND AND EARLY NEXT WEEK. FOR
NOW...IT APPEARS THE BULK OF THE HEAVIEST RAIN WILL REMAIN NORTH OF
OUR REGION...AND WHEN HEAVIER PRECIPITATION ARRIVES...IT WILL REMAIN
TRANSIENT ENOUGH ACROSS OUR FORECAST AREA TO MINIMIZE FLOOD
CONCERNS. NONETHELESS...THIS PATTERN CERTAINLY BEARS
WATCHING...PARTICULARLY ACROSS THE NORTHERN HALF OF THE FORECAST
AREA WHERE A SLIGHT SHIFT IN THE STORM TRACK COULD PUT US IN THE
PATH OF A MODEST FIRE HOSE AND FLOOD CONCERNS WILL RISE. /NEUMAN
&&
.AVIATION...MAINLY VFR CONDITIONS TODAY IN LIGHT TO MODERATE
OFFSHORE FLOW ACROSS FORECAST AREA. A FEW EXCEPTIONS THIS
MORNING...SOME LINGERING MVFR NEAR KAST AND SOME FOG IN THE
WILLAMETTE VALLEY SOUTH OF KCVO. ALSO EASTERLY UPSLOPE FLOW
CAUSING MOUNTAIN OBSCURATIONS ALONG THE EAST SLOPES AND CREST OF
THE CASCADES.
THE MVFR CIGS NEAR KAST SHOULD LIFT AS THE FRONTAL ZONE WHICH
BROUGHT -RA EARLY THIS MORNING CONTINUES TO DRIFT NORTH INTO
WASHINGTON. AS FOR THE LIFR/VLIFR CONDITIONS AROUND KEUG... THEY
WILL PROBABLY BE MORE STUBBORN AS LOW PRESSURE OFF THE NORTHERN CA
COAST CONTINUES TO PULL IN LIGHT N-NE FLOW...JAMMING LOW CLOUDS
AGAINST THE SOUTH END OF THE WILLAMETTE VALLEY. SUSPECT IT WILL
LIFT TO REGULAR IFR WITH CIGS ABOVE 500 FT BY MIDDAY...BUT WILL
PROBABLY DROP BACK DOWN TO NEAR THE DECK LATER TONIGHT AS -RA
REDEVELOPS WITH OUR NEXT FRONTAL SYSTEM.
KPDX AND APPROACHES...VFR CONDITIONS WITH CIGS BETWEEN 4K TO 6K
FT THIS MORNING RISING TO AROUND 12K FT THIS AFTERNOON. LIGHT TO
MODERATE EAST SFC WINDS THROUGH THIS EVENING. WEAGLE
&&
.MARINE...SATELLITE IMAGERY THIS MORNING SHOWS A WELL-DEFINED LOW
PRESSURE SYSTEM ABOUT 200 NM WEST OF CRESCENT CITY CA. THIS
SYSTEM APPEARS TO HAVE STRENGTHENED TO AROUND 995 MB BASED ON
SATELLITE ANALYSIS AND THE MAGNITUDE OF WINDS ASSOCIATED WITH THE
LOW. MODELS APPEAR TO BE INITIALIZING THIS LOW TOO WEAKLY...EVEN
THE 16Z RAP ONLY SHOWS A 1000 MB LOW IN THIS LOCATION. RAPIDSCAT
IMAGERY FROM ABOARD THE INTERNATIONAL SPACE STATION SHOWS
SATELLITE-DERIVED WINDS OF UP TO 40 KT IN SE QUADRANT OF THIS
LOW...AND BUOY 46002 IS GUSTING TO GALE FORCE IN THE NW QUADRANT
OF THE LOW. THIS SYSTEM WILL NEED TO BE WATCHED CLOSELY AS IT
DRIFTS NE TOWARD OREGON THE NEXT 24-36 HRS. HOWEVER IT APPEARS THE
LOW IS APPROACHING ITS MAXIMUM STRENGTH AND WILL LIKELY START
WEAKENING AS MODELS SUGGEST BY TONIGHT. THEREFORE WE DID NOT
DEVIATE TOO FAR FROM THE MODELS WITH OUR WIND/SWELL FORECAST IN
THE NEXT 1-2 DAYS.
THE NEXT RELATIVELY STRONG FRONTAL SYSTEM IS BEGINNING TO TAKE
SHAPE BETWEEN 150W-160W...AND MAY PRODUCE GALES FOR OUR WATERS AS
IT MOVES ONSHORE LATER THU/EARLY FRI. THERE IS A GOOD POTENTIAL
FOR COASTAL JET FORMATION WHICH WOULD ENHANCE WINDS JUST AHEAD OF
THE FRONT WITH GUSTS TO 45 KT POSSIBLE NEAR THE COAST THU NIGHT.
ENP GUIDANCE SUGGESTS A SOLID 16-20 FT SWELL WITH A DOMINANT
PERIOD OF 16-20 SECONDS FOLLOWS THE FRONT...POSSIBLY ENOUGH TO
WARRANT A HIGH SURF ADVISORY FRIDAY. WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL NOON PST TODAY FOR WATERS
FROM CAPE SHOALWATER WA TO CASCADE HEAD OR FROM 10 TO 60 NM-
WATERS FROM CASCADE HEAD TO FLORENCE OR FROM 10 TO 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL NOON PST TODAY
FOR COASTAL WATERS FROM CASCADE HEAD TO FLORENCE OR OUT 10 NM-
WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR FROM 10
TO 60 NM-WATERS FROM CASCADE HEAD TO FLORENCE OR FROM 10 TO
60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 2 PM
PST THIS AFTERNOON.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 11 PM
THIS EVENING TO 3 AM PST WEDNESDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
322 PM CST TUE DEC 16 2014
.DISCUSSION...
A COMPLEX AND PROGRESSIVE UPPER LEVEL PATTERN WILL PREVAIL OVER
THE U.S. INTO EARLY NEXT WEEK. TUESDAY AFTERNOON/S GOES WATER
VAPOR IMAGERY SHOWED TWO UPPER LOWS OFF THE WEST COAST... WITH
SIGNIFICANT UPPER LEVEL UPSTREAM POLAR JET ENERGY OVER THE EASTERN
NORTH PACIFIC. FURTHER SOUTH...A MOISTURE LADEN SUBTROPICAL UPPER
LEVEL JET EXTENDED FROM THE EASTERN PACIFIC...ACROSS NORTHERN
MEXICO... INTO THE SOUTHERN PLAINS.
THIS EVENING SHOULD SEE CONTINUED DISSIPATION OF LOW STRATUS OVER
NORTHERN PORTIONS OF THE MIDSOUTH...FOLLOWED BY INCREASING HIGH
CLOUDS FROM THE SUBTROPICAL JET. BY WEDNESDAY AFTERNOON... AN
EMBEDDED SHORTWAVE WILL LIFT OUT OF THE SOUTHERN ROCKIES AND
DEAMPLIFY DOWNSTREAM OVER THE LOWER AND MIDDLE MS RIVER VALLEY. A
DRY SUBCLOUD LAYER /BELOW 12KFT/ WILL TAKE TIME TO SATURATE...
FINALLY DOING SO LATE WEDNESDAY NIGHT. NORTHERN PORTIONS OF THE
MIDSOUTH MAY SEE LIGHT SNOW OR SLIGHT MIXING IN WITH LIGHT RAIN
TOWARD THURSDAY MORNING. GIVEN ONLY WEAK WARM ADVECTION ALOFT
CONTRIBUTING TO LIFT...PRECIP AMOUNTS ACROSS THE MIDSOUTH SHOULD
BE LIGHT.
THE NEXT PRECIP EVENT APPEARS ON TRACK FOR FRIDAY AFTERNOON
THROUGH SATURDAY MORNING. THIS SYSTEM WILL BE BETTER ORGANIZED
THAN THE WEDNESDAY NIGHT SYSTEM...GIVEN THAT IT WILL PHASE WITH
NORTHERN BRANCH ENERGY. 12Z GFS AND 12Z ECMWF HAVE SETTLED ON THE
SOLUTION ORIGINALLY ADVERTISED BY THE GFS A FEW DAYS AGO. HEAVIER
CONVECTIVE RAINS WILL BE LIKELY OVER NORTH MS AND POINTS SOUTH
FRIDAY NIGHT... WHILE LIGHTER RAIN MAY MIX WITH LIGHT SNOW AT
TIMES FROM NORTHEAST AR INTO NORTHWEST TN BY SATURDAY MORNING.
THIS SYSTEM QUICKLY LIFT OUT...LEAVING SATURDAY AFTERNOON AND
EVENING WITH DRY CONDITIONS...BUT POSSIBLY SLOW TO DISSIPATE
POST FRONTAL CLOUDINESS.
DISPARITIES BETWEEN TODAY/S 12Z GFS AND ECMWF SOLUTIONS BEGIN TO
AMPLIFY...LEADING TO REDUCED FORECAST CONFIDENCE TOWARD THE
CHRISTMAS HOLIDAY. BOTH MODELS DEPICT ADDITIONAL ENERGY COMING
ONSHORE OVER THE WESTERN U.S...BUT DIFFER ON TIMING AND DOWNSTREAM
EVOLUTION ACROSS THE REMAINDER OF THE LOWER 48.
PWB
&&
.AVIATION...
18Z TAF CYCLE
MAIN FORECAST ISSUE THIS TAF CYCLE WILL BE MVFR CIGS ON SW PERIPHERY
OF MIDWEST/GREAT LAKES SYSTEM. LATEST HIGH-RES MODELS SUGGEST CIGS
CLEARING KJBR BY AROUND 22Z...WITH TEMPO MVFR CIGS AT KMEM THRU
AROUND 22Z. HRRR IS QUICKER WITH TIMING THAN RAP...SO WILL DO A BIT
OF BLENDING ON THE TIMING. CIGS SHOULD HOLD AT KMKL WELL INTO THE
NIGHT. FORECAST SURFACE RH SUGGESTS POSSIBILITY OF MIST/FOG AT
KMEM...WILL HINT AT IT IN TAF AND MONITOR TRENDS/LATER GUIDANCE.
WINDS WILL GRADUALLY DECREASE AND VEER TO NLY/NNELY AS SURFACE RIDGE
SETTLES INTO AREA.
GW
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1146 AM CST TUE DEC 16 2014
.DISCUSSION...
UPDATED FOR 18Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 319 AM CST TUE DEC 16 2014/
CLOUDS ARE SPREADING SOUTH ACROSS THE FORECAST AREA EARLY THIS
MORNING WITH TEMPERATURES MAINLY IN THE 40S. THESE CLOUDS ARE
ASSOCIATED WITH AN UPPER LEVEL LOW CURRENTLY MOVING ACROSS CENTRAL
ILLINOIS. AS THE LOW MOVES EAST TODAY THE CLOUDS WILL EVENTUALLY
MOVE OUT OF THE REGION BUT MOST OF THE DAY SHOULD BE FAIRLY
CLOUDY. BECAUSE OF THE CLOUD COVER TEMPERATURES WILL NOT WARM UP
TOO MUCH TODAY WITH HIGHS IN THE UPPER 40S TO LOWER 50S.
AS SKIES CLEAR TONIGHT...TEMPERATURES WILL BE COLDER THAN THEY
HAVE BEEN FOR THE LAST COUPLE OF DAYS WITH LOWS WEDNESDAY MORNING
IN THE UPPER 20S TO LOWER 30S. HIGH PRESSURE WILL REMAIN OVER THE
REGION ON WEDNESDAY KEEPING THINGS DRY AND UNSEASONABLY COOL WITH
HIGHS IN THE LOWER 40S TO AROUND 50 DEGREES.
BY WEDNESDAY NIGHT LOW PRESSURE WILL BE OVER WEST TEXAS AND WITH
SOUTH WINDS OVER THE REGION MOISTURE WILL INCREASE ACROSS THE
FORECAST AREA. THIS WILL PRODUCE SOME LIGHT PRECIPITATION MAINLY
IN THE FORM OF RAIN WITH SOME LIGHT SNOW POSSIBLE OVER NORTHERN
SECTIONS OF THE FORECAST AREA AS TEMPERATURES APPROACH THE
FREEZING MARK BY THURSDAY MORNING. SOME LIGHT PRECIPITATION WILL
CONTINUE INTO THURSDAY WITH SOME LIGHT SNOW POSSIBLE THURSDAY
MORNING OVER NORTHERN SECTIONS OF FORECAST AREA.
ANOTHER DISTURBANCE WILL APPROACH THE REGION THURSDAY NIGHT
BRINGING MORE PRECIPITATION MAINLY OVER SOUTHWEST SECTIONS OF THE
FORECAST AREA. BY FRIDAY...LOW PRESSURE WILL BE OVER SOUTHEAST
TEXAS AND WILL TRACK ACROSS THE GULF COAST STATES REACHING
SOUTHEAST ALABAMA BY SATURDAY MORNING. THIS SYSTEM WILL BRING MORE
PRECIPITATION TO THE REGION MAINLY IN THE FORM OF RAIN FRIDAY AND
FRIDAY NIGHT BUT SOME LIGHT SNOW WILL BE POSSIBLE OVER PORTIONS OF
NORTHEAST ARKANSAS AND THE MISSOURI BOOTHEEL LATE FRIDAY NIGHT AND
EARLY SATURDAY MORNING. AS THE LOW CONTINUES TO MOVE EAST ON
SATURDAY RAIN WILL BE ENDING.
HIGH PRESSURE WILL BUILD BACK INTO THE REGION SATURDAY NIGHT
BRINGING A PERIOD OF DRY WEATHER FOR SATURDAY NIGHT THROUGH
MONDAY. TEMPERATURES WILL BE NEAR OR SLIGHTLY BELOW NORMAL LEVELS
DURING THIS PERIOD.
ARS
&&
.AVIATION...
18Z TAF CYCLE
MAIN FORECAST ISSUE THIS TAF CYCLE WILL BE MVFR CIGS ON SW PERIPHERY
OF MIDWEST/GREAT LAKES SYSTEM. LATEST HIGH-RES MODELS SUGGEST CIGS
CLEARING KJBR BY AROUND 22Z...WITH TEMPO MVFR CIGS AT KMEM THRU
AROUND 22Z. HRRR IS QUICKER WITH TIMING THAN RAP...SO WILL DO A BIT
OF BLENDING ON THE TIMING. CIGS SHOULD HOLD AT KMKL WELL INTO THE
NIGHT. FORECAST SURFACE RH SUGGESTS POSSIBILITY OF MIST/FOG AT
KMEM...WILL HINT AT IT IN TAF AND MONITOR TRENDS/LATER GUIDANCE.
WINDS WILL GRADUALLY DECREASE AND VEER TO NLY/NNELY AS SURFACE RIDGE
SETTLES INTO AREA.
GW
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
313 PM CST TUE DEC 16 2014
.DISCUSSION...
THE BEST DAY OF THE WEEK WEATHER-WISE AS THE MAJORITY OF THE REGION
IS UNDER CLEAR SKIES...AFTERNOON TEMPERATURE READINGS WARMING INTO
THE SEASONABLE LOWER TO MIDDLE 60S UNDER A LIGHT NORTH WIND. AS
THE 1030 MB SURFACE HIGH...CURRENTLY CENTERED OVER THE CENTRAL RED
RIVER VALLEY...TRAVELS NORTHEAST OVER THE NEXT 24 HOURS WINDS WILL
VEER MORE EASTERLY TO EVENTUAL SOUTHEASTERLY WEDNESDAY NIGHT. THIS
WILL AID IN DRAWING UP MORE MOISTURE RICH AIR INTO THE FORECAST AREA.
GREATER THAN 50% LOW TO MID LEVEL RH VALUES ARE CURRENTLY BEING PROGGED
BY THE GFS AND NAM TO ADVANCE UPON THE WESTERN COUNTIES THROUGH THE
EARLY MORNING HOURS. THIS WILL BE THE FLY IN THE OINTMENT THAT REGULATES
WESTERN CWA MINIMUM TEMPERATURES...CLOUDS WILL KEEP MINS TO THE MID
40S WITH SLOW-ADVANCING CLOUDS FROM THE WEST ALLOWING THESE SITES
TO FALL BELOW 40F. HAVE SPLIT THE DIFFERENCE AND WENT WITH THE AVERAGE
LOWER 40S OUT WEST...MIDDLE 40S ELSEWHERE OVER THE INTERIOR...CLEARER
SKIES OVER THE LAKE LIVINGSTON AREA WILL AFFORD THE UPPER 30S.
A WARM AIR ADVECTION PATTERN SETS UP WEDNESDAY THROUGH THURSDAY THAT
WILL GRADUALLY DETERIORATE CONDITIONS FROM WEST TO EAST. INCREASING
OVERCAST THROUGH WEDNESDAY AFTERNOON WILL LEAD TO EITHER DRIZZLE
OR VERY LIGHT RAIN SHOWERS FORMING OVER THE WEST CENTRAL ZONES AND
ADVANCING EASTWARD THROUGH THE OVERNIGHT EARLY THURSDAY MORNING
HOURS. AS OVERNIGHT TEMPERATURES FALL INTO THE LOWER TO MIDDLE 50S
THIS WILL CLOSE THE DEW POINT DEPRESSION ENOUGH TO SATURATE THE
LOWER LEVELS...LOWERING CLOUDS BASES AND INTRODUCING FOG WITHIN
LIGHT PRECIPITATION. A MURKY THURSDAY MORNING WILL BE THE PRECURSOR
TO AN OVERCAST DAY WITH HIGH PROBS OF SCATTERED SHOWERS WITH
ISOLATED THUNDER AS A WEAK SURFACE BOUNDARY HANGS UP OVER THE CWA.
EASTERN TEXAS MIGHT ALSO FALL UNDER THE RR QUAD OF A PRONOUNCED
JET JUST DOWNSTREAM OF THE NEXT MAJOR WEATHER MAKER FRIDAY.
THIS FEATURE BEING A WESTERN LONG WAVE TROUGH THAT WILL PASS OVER
THE REGION DURING THE DAY FRIDAY...INCREASING AREAWIDE POPS TO
LIKELY FOR SHOWERS AND STORMS. AS OF NOW...THE GFS AND ECMWF
SOLUTIONS DEVELOP A COASTAL TROUGH OR CLOSED OFF LOW THAT WOULD
MAKE FOR A MORE ACTIVE DAY...QPF RANGING FROM AROUND A HALF OF AN
INCH AROUND THE COAST TO SLIGHTLY OVER TWO INCHES OVER OUR NORTHERN
ZONES. ALL DEPENDENT UPON THE POSITIONING OF THE UPPER TROUGH
AND/OR APPENDANT SURFACE TROF/LOW ON WHERE THE HIGHEST RAIN
FALLS...BUT NWP PROGS AND WPC DO PLACE THE HIGHEST DAY 3 RAINFALL
OVER THE NORTHERN HALF OF THE FORECAST AREA. AGGRESSIVE COLD
FRONTAL PASSAGE SATURDAY WILL WHISK ALL CONVECTION EAST BY SUNRISE
SATURDAY. THE BACKING SURFACE HIGH WILL ELONGATE BACK INTO THE
REGION FROM THE MIDWESTERN U.S. AND PRODUCE A PERSISTENT NE-E
FLOW THROUGH EARLY CHRISTMAS WEEK. THE CHRISTMAS DAY OUTLOOK HAS
LOWERING WESTERN TEXAS PRESSURES MAINTAINING A LIGHT TO MODERATE
ONSHORE FLOW...LOW RAIN CHANCES WITH SEASONABLE TEMPERATURE TRENDS.
31
&&
.MARINE...
HIGH PRESSURE WILL BUILD INTO THE SOUTHERN PLAINS THIS EVENING AND
WINDS WILL SUBSIDE AND GENTLY VEER TO THE NE AS THE HIGH DRIFTS
EAST. ONSHORE WINDS ARE EXPECTED TO RETURN WEDNESDAY AFTERNOON AS
THE HIGH MOVES FURTHER EAST. ONSHORE WINDS WILL PERSIST THROUGH
FRIDAY MORNING AS LOW PRESSURE DEVELOPS OVER SOUTH TEXAS AND
SCOOTS UP THE COAST ON FRIDAY AFTERNOON. A COLD FRONT WILL CROSS
THE COAST FRIDAY EVENING AND STRONG OFFSHORE WINDS WILL DEVELOP IN
THE WAKE OF THE FRONT. A SMALL CRAFT ADVISORY MAY BE REQUIRED FRI
NIGHT INTO SATURDAY. WINDS WILL BEGIN TO RELAX BY SAT EVENING AS
HIGH PRESSURE SETTLES OVER THE CENTRAL PLAINS. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 43 54 52 65 57 / 0 40 50 30 80
HOUSTON (IAH) 44 59 55 70 60 / 0 20 50 50 60
GALVESTON (GLS) 53 62 61 69 63 / 0 20 40 40 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 3 PM CST THIS
AFTERNOON 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.
&&
$$
DISCUSSION...31/43
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
228 PM MST TUE DEC 16 2014
.UPDATE...
ISSUED AT 225 PM MST TUE DEC 16 2014
ONE FINAL AFTERNOON GRIDDED FORECAST AND ZONE FORECAST UPDATE
TO ACCOUNT FOR MAXIMUM TEMPERATURES...WHICH VARY GREATLY DEPENDING
ON CLOUD COVER AND RESIDUAL SNOWPACK...WITH 2 PM TEMPERATURES IN
THE LOWER 30S AT RAWLINS...LARAMIE AND CHEYENNE...AND TEMPERATURES
ONLY IN THE UPPER TEENS TO UPPER 20S AT DOUGLAS...TORRINGTON...
CHADRON...SCOTTSBLUFF...ALLIANCE...KIMBALL AND SIDNEY.
UPDATE ISSUED AT 1018 AM MST TUE DEC 16 2014
OUR MIDNIGHT SHIFT TEAM HAD THE FOG WELL COVERED AT TORRINGTON...
SCOTTSBLUFF AND ALLIANCE...AND ALONG THE NORTH PLATTE RIVER
VALLEY. EVEN AT 10 AM...VISIBILITIES IN FOG WERE STILL ONLY
ONE QUARTER OF A MILE AT ALLIANCE...ONE HALF MILE AT SCOTTSBLUFF
AND OVER TWO MILES AT TORRINGTON. EXTENDED FOG FOR A FEW HOURS
IN OUR GRIDDED FORECASTS.
FOR OUR AFTERNOON FORECAST...NEGATIVELY TILTED SHORTWAVE TROUGH
ALOFT MOVES NORTHEAST ACROSS EASTERN IDAHO...NORTHERN UTAH AND
WESTERN WYOMING...WITH THE 12Z NAM SPREADING LIGHT SNOW ACROSS
MUCH OF CARBON AND ALBANY COUNTIES...THUS HAVE ADJUSTED OUR
POPS AND SNOW COVERAGE GRIDS THERE TO MATCH EXPECTED SNOW
COVERAGE. ALSO ADJUSTED OUR MAXIMUM TEMPERATURES THIS AFTERNOON
AS WITH CLOUD COVER AND SNOWFIELD...TEMPERATURES WILL STRUGGLE
TO CLIMB ABOVE FREEZING AT SOME LOCATIONS ESPECIALLY ALONG THE
NORTH PLATTE RIVER VALLEY. ADJUSTED DEWPOINTS AND CLOUD COVER TO
MATCH TRENDS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 330 AM MST TUE DEC 16 2014
CHILLY NIGHT ACROSS THE REGION ESPECIALLY FOR THOSE AREAS IN THE
SOUTHERN NEBRASKA PANHANDLE WHERE SKIES ARE CLEAR AND WIDESPREAD
SNOW IS ON THE GROUND. TEMPERATURES IN THE NORTHERN PANHANDLE ARE
ABOUT 10 DEGREES WARMER DUE TO THE LOW CLOUDS AND PATCHY FOG. ALSO
GETTING FOG IN THE NORTH PLATTE RIVER VALLEY FROM DOUGLAS TO
TORRINGTON WITH REALLY LIGHT WINDS. THE HRRR SUGGESTS THAT THE LOW
CLOUDS WILL BE QUITE PERSISTENT OVER THE PANHANDLE THROUGH LATE
MORNING. GENERALLY QUIET WEATHER OVER THE NEXT FEW DAYS WITH WEAK
SFC PRESSURE GRADIENTS AND A LACK OF IMPACTFUL WEATHER SYSTEMS.
THE MODELS SHOW A SHORTWAVE TROUGH MOVING FROM THE GREAT BASIN
INTO WESTERN WY THIS AFTN INTO TONIGHT. IR IMAGERY CURRENTLY SHOWS
QUITE A BIT OF MIDLVL MOISTURE STREAMING NORTHEASTWARD INTO
COLORADO. THIS MOISTURE WILL PUSH ACROSS THE REGION BY THIS AFTN.
INCREASED POPS A BIT FOR THE SIERRA MADRE AND SNOWY RANGES FOR THE
AFTN...HOWEVER ONLY EXPECTING A FEW INCHES AT MOST. HIGH
TEMPERATURES WILL BE AROUND NORMAL OVER THE NEXT FEW DAYS
(GENERALLY IN THE MID-TO-UPPER 30S)...WHICH MEANS THAT SNOW COVER
FROM THE RECENT STORM WILL BE SLOW TO MELT.
SYNOPTIC PATTERN DOES NOT CHANGE A WHOLE LOT THROUGH THURSDAY.
SIMILAR TO THE LAST FEW WEEKS...THE UPPER LEVEL JET WILL BE REMAIN
ACROSS THE SOUTHWESTERN UNITED STATES WITH WEAK FLOW ALOFT OVER
WY. NO WIND CONCERNS AS THE CAG-CPR GRADIENT NEVER GETS ABOVE 20
METERS. A SFC HIGH OVER THE NORTHERN PLAINS WILL MAINTAIN SOUTH TO
SOUTHEAST WINDS OVER THE NEBRASKA PANHANDLE THROUGH WED NIGHT. THE
NAM AND SREF SHOW THE POTENTIAL FOR LOW CLOUD FORMATION TONIGHT
AND MORE SO ON WED NIGHT. THE MODELS HAVE BEEN CONSISTENT AT
SHOWING MUCH OF THE MOISTURE AND DYNAMICS ASSOCIATED WITH AN UPPER
LEVEL WAVE REMAINING SOUTH OF THE CWA ON WED AND WED NIGHT. KEPT
SLIGHT CHANCE POPS OVER THE SIERRA MADRE AND SNOWY RANGES...WITH
THE BEST CHANCES OF SNOW OVER COLORADO.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 330 AM MST TUE DEC 16 2014
SEASONAL AND A RELATIVELY TRANQUIL PERIOD THROUGH THE UPCOMING
WEEKEND. WARMER AND BREEZY TO LOCALLY WINDY CONDITIONS RETURN
EARLY NEXT WEEK. PERSISTENT NORTHWEST FLOW WILL BE IN PLACE FRIDAY
THRU SUNDAY WITH PERIODIC EMBEDDED SHORTWAVES PASSING OVER THE
REGION. LIGHT MOUNTAIN SNOW WILL BE A POSSIBILITY THRU THE PERIOD
ALONG WITH PERIODIC BOUTS OF CLOUD-COVER ELSEWHERE...THICKEST NEAR
SHORTWAVE ENERGY. SEE LITTLE MOVEMENT IN TEMPERATURES DURING THIS
PERIOD AS WELL AS NORTHWEST FLOW KEEP ADVECTION NEUTRAL. SO HIGHS
IN THE LOW 30S WEST OF THE LARAMIE RANGE AND 30S TO NR 40 EAST CAN
BE EXPECTED.
WINDS WILL STRENGTHEN FOR MONDAY/TUESDAY AS THE NOSE OF 150+ KNOT H3
JET STREAK APPROACHES AND MOVES OVERHEAD. ALTHOUGH TIMING
DIFFERENCES EXIST IN WHEN THE LLVL GRADIENT IS THE STRONGEST...BOTH
ARE SIMILAR IN PROGGING 50-60 KNOTS AT H7 FOR MONDAY AND TUESDAY. IF
SUBSEQUENT MODEL OUTPUT CONTINUES...THIS WOULD BE ENOUGH FOR THE
POSSIBILITY OF THE NEXT HIGH WIND EVENT MAINLY FOR WIND PRONE
AREAS. CHANNELED VORT ENERGY WILL ALSO PROVIDE CHANCES FOR SNOW
SHOWERS MONDAY AND TUESDAY AS WELL. MODELS AGAIN HAVE TIMING
DIFFERENCES DURING THIS PERIOD...SO FOR NOW JUST INTRODUCED SOME
LIGHT SNOW CHANCES DURING THIS PERIOD. DOWNSLOPE COMPONENT WILL
BOOST HIGH TEMPS MONDAY/TUESDAY INTO THE MID/UPPER 30S WEST AND
LOW/MID 40S OUT ON THE ERN PLAINS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1113 AM MST TUE DEC 16 2014
FOG/LOW STRATUS PERSISTS MAINLY IN THE NORTH PLATTE RIVER VALLEY
AND NEAR KCDR THIS MORNING...WITH VFR CONDITIONS ELSEWHERE. LIFTED
CIGS/VSBYS AROUND 20/21Z FOR THESE SITES ALTHO NOT CONFIDENT
CONDITIONS WILL IMPROVE MUCH BEFORE DROPPING ONCE AGAIN LATER THIS
EVENING. STILL EXPECT -SHSN EARLY THIS AFTERNOON AT THE WYO
SITES...WITH IFR CIGS/VSBYS EXPECTED AT KRWL IN MOIST SOUTHEAST
FLOW AFTER 05Z THIS EVENING. WINDS OVERALL WILL REMAIN RELATIVELY
LIGHT...EXCEPT NEAR KRWL WHERE GUSTS OF 20 TO 25 KTS ARE POSSIBLE
THIS AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 330 AM MST TUE DEC 16 2014
NO FIRE WEATHER CONCERNS OVER THE NEXT FEW DAYS. COLD TEMPERATURES
WILL KEEP SNOW COVER ON THE GROUND ACROSS MUCH OF THE REGION.
AFTERNOON HUMIDITY VALUES WILL GENERALLY BE ABOVE 50 PERCENT AND
WINDS WILL BE LIGHT.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...RUBIN
SHORT TERM...ZF
LONG TERM...CAH
AVIATION...RJM
FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1113 AM MST TUE DEC 16 2014
.UPDATE...
ISSUED AT 1018 AM MST TUE DEC 16 2014
OUR MIDNIGHT SHIFT TEAM HAD THE FOG WELL COVERED AT TORRINGTON...
SCOTTSBLUFF AND ALLIANCE...AND ALONG THE NORTH PLATTE RIVER
VALLEY. EVEN AT 10 AM...VISIBILITIES IN FOG WERE STILL ONLY
ONE QUARTER OF A MILE AT ALLIANCE...ONE HALF MILE AT SCOTTSBLUFF
AND OVER TWO MILES AT TORRINGTON. EXTENDED FOG FOR A FEW HOURS
IN OUR GRIDDED FORECASTS.
FOR OUR AFTERNOON FORECAST...NEGATIVELY TILTED SHORTWAVE TROUGH
ALOFT MOVES NORTHEAST ACROSS EASTERN IDAHO...NORTHERN UTAH AND
WESTERN WYOMING...WITH THE 12Z NAM SPREADING LIGHT SNOW ACROSS
MUCH OF CARBON AND ALBANY COUNTIES...THUS HAVE ADJUSTED OUR
POPS AND SNOW COVERAGE GRIDS THERE TO MATCH EXPECTED SNOW
COVERAGE. ALSO ADJUSTED OUR MAXIMUM TEMPERATURES THIS AFTERNOON
AS WITH CLOUD COVER AND SNOWFIELD...TEMPERATURES WILL STRUGGLE
TO CLIMB ABOVE FREEZING AT SOME LOCATIONS ESPECIALLY ALONG THE
NORTH PLATTE RIVER VALLEY. ADJUSTED DEWPOINTS AND CLOUD COVER TO
MATCH TRENDS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 330 AM MST TUE DEC 16 2014
CHILLY NIGHT ACROSS THE REGION ESPECIALLY FOR THOSE AREAS IN THE
SOUTHERN NEBRASKA PANHANDLE WHERE SKIES ARE CLEAR AND WIDESPREAD
SNOW IS ON THE GROUND. TEMPERATURES IN THE NORTHERN PANHANDLE ARE
ABOUT 10 DEGREES WARMER DUE TO THE LOW CLOUDS AND PATCHY FOG. ALSO
GETTING FOG IN THE NORTH PLATTE RIVER VALLEY FROM DOUGLAS TO
TORRINGTON WITH REALLY LIGHT WINDS. THE HRRR SUGGESTS THAT THE LOW
CLOUDS WILL BE QUITE PERSISTENT OVER THE PANHANDLE THROUGH LATE
MORNING. GENERALLY QUIET WEATHER OVER THE NEXT FEW DAYS WITH WEAK
SFC PRESSURE GRADIENTS AND A LACK OF IMPACTFUL WEATHER SYSTEMS.
THE MODELS SHOW A SHORTWAVE TROUGH MOVING FROM THE GREAT BASIN
INTO WESTERN WY THIS AFTN INTO TONIGHT. IR IMAGERY CURRENTLY SHOWS
QUITE A BIT OF MIDLVL MOISTURE STREAMING NORTHEASTWARD INTO
COLORADO. THIS MOISTURE WILL PUSH ACROSS THE REGION BY THIS AFTN.
INCREASED POPS A BIT FOR THE SIERRA MADRE AND SNOWY RANGES FOR THE
AFTN...HOWEVER ONLY EXPECTING A FEW INCHES AT MOST. HIGH
TEMPERATURES WILL BE AROUND NORMAL OVER THE NEXT FEW DAYS
(GENERALLY IN THE MID-TO-UPPER 30S)...WHICH MEANS THAT SNOW COVER
FROM THE RECENT STORM WILL BE SLOW TO MELT.
SYNOPTIC PATTERN DOES NOT CHANGE A WHOLE LOT THROUGH THURSDAY.
SIMILAR TO THE LAST FEW WEEKS...THE UPPER LEVEL JET WILL BE REMAIN
ACROSS THE SOUTHWESTERN UNITED STATES WITH WEAK FLOW ALOFT OVER
WY. NO WIND CONCERNS AS THE CAG-CPR GRADIENT NEVER GETS ABOVE 20
METERS. A SFC HIGH OVER THE NORTHERN PLAINS WILL MAINTAIN SOUTH TO
SOUTHEAST WINDS OVER THE NEBRASKA PANHANDLE THROUGH WED NIGHT. THE
NAM AND SREF SHOW THE POTENTIAL FOR LOW CLOUD FORMATION TONIGHT
AND MORE SO ON WED NIGHT. THE MODELS HAVE BEEN CONSISTENT AT
SHOWING MUCH OF THE MOISTURE AND DYNAMICS ASSOCIATED WITH AN UPPER
LEVEL WAVE REMAINING SOUTH OF THE CWA ON WED AND WED NIGHT. KEPT
SLIGHT CHANCE POPS OVER THE SIERRA MADRE AND SNOWY RANGES...WITH
THE BEST CHANCES OF SNOW OVER COLORADO.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 330 AM MST TUE DEC 16 2014
SEASONAL AND A RELATIVELY TRANQUIL PERIOD THROUGH THE UPCOMING
WEEKEND. WARMER AND BREEZY TO LOCALLY WINDY CONDITIONS RETURN
EARLY NEXT WEEK. PERSISTENT NORTHWEST FLOW WILL BE IN PLACE FRIDAY
THRU SUNDAY WITH PERIODIC EMBEDDED SHORTWAVES PASSING OVER THE
REGION. LIGHT MOUNTAIN SNOW WILL BE A POSSIBILITY THRU THE PERIOD
ALONG WITH PERIODIC BOUTS OF CLOUD-COVER ELSEWHERE...THICKEST NEAR
SHORTWAVE ENERGY. SEE LITTLE MOVEMENT IN TEMPERATURES DURING THIS
PERIOD AS WELL AS NORTHWEST FLOW KEEP ADVECTION NEUTRAL. SO HIGHS
IN THE LOW 30S WEST OF THE LARAMIE RANGE AND 30S TO NR 40 EAST CAN
BE EXPECTED.
WINDS WILL STRENGTHEN FOR MONDAY/TUESDAY AS THE NOSE OF 150+ KNOT H3
JET STREAK APPROACHES AND MOVES OVERHEAD. ALTHOUGH TIMING
DIFFERENCES EXIST IN WHEN THE LLVL GRADIENT IS THE STRONGEST...BOTH
ARE SIMILAR IN PROGGING 50-60 KNOTS AT H7 FOR MONDAY AND TUESDAY. IF
SUBSEQUENT MODEL OUTPUT CONTINUES...THIS WOULD BE ENOUGH FOR THE
POSSIBILITY OF THE NEXT HIGH WIND EVENT MAINLY FOR WIND PRONE
AREAS. CHANNELED VORT ENERGY WILL ALSO PROVIDE CHANCES FOR SNOW
SHOWERS MONDAY AND TUESDAY AS WELL. MODELS AGAIN HAVE TIMING
DIFFERENCES DURING THIS PERIOD...SO FOR NOW JUST INTRODUCED SOME
LIGHT SNOW CHANCES DURING THIS PERIOD. DOWNSLOPE COMPONENT WILL
BOOST HIGH TEMPS MONDAY/TUESDAY INTO THE MID/UPPER 30S WEST AND
LOW/MID 40S OUT ON THE ERN PLAINS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1113 AM MST TUE DEC 16 2014
FOG/LOW STRATUS PERSISTS MAINLY IN THE NORTH PLATTE RIVER VALLEY
AND NEAR KCDR THIS MORNING...WITH VFR CONDITIONS ELSEWHERE. LIFTED
CIGS/VSBYS AROUND 20/21Z FOR THESE SITES ALTHO NOT CONFIDENT
CONDITIONS WILL IMPROVE MUCH BEFORE DROPPING ONCE AGAIN LATER THIS
EVENING. STILL EXPECT -SHSN EARLY THIS AFTERNOON AT THE WYO
SITES...WITH IFR CIGS/VSBYS EXPECTED AT KRWL IN MOIST SOUTHEAST
FLOW AFTER 05Z THIS EVENING. WINDS OVERALL WILL REMAIN RELATIVELY
LIGHT...EXCEPT NEAR KRWL WHERE GUSTS OF 20 TO 25 KTS ARE POSSIBLE
THIS AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 330 AM MST TUE DEC 16 2014
NO FIRE WEATHER CONCERNS OVER THE NEXT FEW DAYS. COLD TEMPERATURES
WILL KEEP SNOW COVER ON THE GROUND ACROSS MUCH OF THE REGION.
AFTERNOON HUMIDITY VALUES WILL GENERALLY BE ABOVE 50 PERCENT AND
WINDS WILL BE LIGHT.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...RUBIN
SHORT TERM...ZF
LONG TERM...CAH
AVIATION...RJM
FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1033 AM MST TUE DEC 16 2014
.UPDATE...
ISSUED AT 1018 AM MST TUE DEC 16 2014
OUR MIDNIGHT SHIFT TEAM HAD THE FOG WELL COVERED AT TORRINGTON...
SCOTTSBLUFF AND ALLIANCE...AND ALONG THE NORTH PLATTE RIVER
VALLEY. EVEN AT 10 AM...VISIBILITIES IN FOG WERE STILL ONLY
ONE QUARTER OF A MILE AT ALLIANCE...ONE HALF MILE AT SCOTTSBLUFF
AND OVER TWO MILES AT TORRINGTON. EXTENDED FOG FOR A FEW HOURS
IN OUR GRIDDED FORECASTS.
FOR OUR AFTERNOON FORECAST...NEGATIVELY TILTED SHORTWAVE TROUGH
ALOFT MOVES NORTHEAST ACROSS EASTERN IDAHO...NORTHERN UTAH AND
WESTERN WYOMING...WITH THE 12Z NAM SPREADING LIGHT SNOW ACROSS
MUCH OF CARBON AND ALBANY COUNTIES...THUS HAVE ADJUSTED OUR
POPS AND SNOW COVERAGE GRIDS THERE TO MATCH EXPECTED SNOW
COVERAGE. ALSO ADJUSTED OUR MAXIMUM TEMPERATURES THIS AFTERNOON
AS WITH CLOUD COVER AND SNOWFIELD...TEMPERATURES WILL STRUGGLE
TO CLIMB ABOVE FREEZING AT SOME LOCATIONS ESPECIALLY ALONG THE
NORTH PLATTE RIVER VALLEY. ADJUSTED DEWPOINTS AND CLOUD COVER TO
MATCH TRENDS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 330 AM MST TUE DEC 16 2014
CHILLY NIGHT ACROSS THE REGION ESPECIALLY FOR THOSE AREAS IN THE
SOUTHERN NEBRASKA PANHANDLE WHERE SKIES ARE CLEAR AND WIDESPREAD
SNOW IS ON THE GROUND. TEMPERATURES IN THE NORTHERN PANHANDLE ARE
ABOUT 10 DEGREES WARMER DUE TO THE LOW CLOUDS AND PATCHY FOG. ALSO
GETTING FOG IN THE NORTH PLATTE RIVER VALLEY FROM DOUGLAS TO
TORRINGTON WITH REALLY LIGHT WINDS. THE HRRR SUGGESTS THAT THE LOW
CLOUDS WILL BE QUITE PERSISTENT OVER THE PANHANDLE THROUGH LATE
MORNING. GENERALLY QUIET WEATHER OVER THE NEXT FEW DAYS WITH WEAK
SFC PRESSURE GRADIENTS AND A LACK OF IMPACTFUL WEATHER SYSTEMS.
THE MODELS SHOW A SHORTWAVE TROUGH MOVING FROM THE GREAT BASIN
INTO WESTERN WY THIS AFTN INTO TONIGHT. IR IMAGERY CURRENTLY SHOWS
QUITE A BIT OF MIDLVL MOISTURE STREAMING NORTHEASTWARD INTO
COLORADO. THIS MOISTURE WILL PUSH ACROSS THE REGION BY THIS AFTN.
INCREASED POPS A BIT FOR THE SIERRA MADRE AND SNOWY RANGES FOR THE
AFTN...HOWEVER ONLY EXPECTING A FEW INCHES AT MOST. HIGH
TEMPERATURES WILL BE AROUND NORMAL OVER THE NEXT FEW DAYS
(GENERALLY IN THE MID-TO-UPPER 30S)...WHICH MEANS THAT SNOW COVER
FROM THE RECENT STORM WILL BE SLOW TO MELT.
SYNOPTIC PATTERN DOES NOT CHANGE A WHOLE LOT THROUGH THURSDAY.
SIMILAR TO THE LAST FEW WEEKS...THE UPPER LEVEL JET WILL BE REMAIN
ACROSS THE SOUTHWESTERN UNITED STATES WITH WEAK FLOW ALOFT OVER
WY. NO WIND CONCERNS AS THE CAG-CPR GRADIENT NEVER GETS ABOVE 20
METERS. A SFC HIGH OVER THE NORTHERN PLAINS WILL MAINTAIN SOUTH TO
SOUTHEAST WINDS OVER THE NEBRASKA PANHANDLE THROUGH WED NIGHT. THE
NAM AND SREF SHOW THE POTENTIAL FOR LOW CLOUD FORMATION TONIGHT
AND MORE SO ON WED NIGHT. THE MODELS HAVE BEEN CONSISTENT AT
SHOWING MUCH OF THE MOISTURE AND DYNAMICS ASSOCIATED WITH AN UPPER
LEVEL WAVE REMAINING SOUTH OF THE CWA ON WED AND WED NIGHT. KEPT
SLIGHT CHANCE POPS OVER THE SIERRA MADRE AND SNOWY RANGES...WITH
THE BEST CHANCES OF SNOW OVER COLORADO.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 330 AM MST TUE DEC 16 2014
SEASONAL AND A RELATIVELY TRANQUIL PERIOD THROUGH THE UPCOMING
WEEKEND. WARMER AND BREEZY TO LOCALLY WINDY CONDITIONS RETURN
EARLY NEXT WEEK. PERSISTENT NORTHWEST FLOW WILL BE IN PLACE FRIDAY
THRU SUNDAY WITH PERIODIC EMBEDDED SHORTWAVES PASSING OVER THE
REGION. LIGHT MOUNTAIN SNOW WILL BE A POSSIBILITY THRU THE PERIOD
ALONG WITH PERIODIC BOUTS OF CLOUD-COVER ELSEWHERE...THICKEST NEAR
SHORTWAVE ENERGY. SEE LITTLE MOVEMENT IN TEMPERATURES DURING THIS
PERIOD AS WELL AS NORTHWEST FLOW KEEP ADVECTION NEUTRAL. SO HIGHS
IN THE LOW 30S WEST OF THE LARAMIE RANGE AND 30S TO NR 40 EAST CAN
BE EXPECTED.
WINDS WILL STRENGTHEN FOR MONDAY/TUESDAY AS THE NOSE OF 150+ KNOT H3
JET STREAK APPROACHES AND MOVES OVERHEAD. ALTHOUGH TIMING
DIFFERENCES EXIST IN WHEN THE LLVL GRADIENT IS THE STRONGEST...BOTH
ARE SIMILAR IN PROGGING 50-60 KNOTS AT H7 FOR MONDAY AND TUESDAY. IF
SUBSEQUENT MODEL OUTPUT CONTINUES...THIS WOULD BE ENOUGH FOR THE
POSSIBILITY OF THE NEXT HIGH WIND EVENT MAINLY FOR WIND PRONE
AREAS. CHANNELED VORT ENERGY WILL ALSO PROVIDE CHANCES FOR SNOW
SHOWERS MONDAY AND TUESDAY AS WELL. MODELS AGAIN HAVE TIMING
DIFFERENCES DURING THIS PERIOD...SO FOR NOW JUST INTRODUCED SOME
LIGHT SNOW CHANCES DURING THIS PERIOD. DOWNSLOPE COMPONENT WILL
BOOST HIGH TEMPS MONDAY/TUESDAY INTO THE MID/UPPER 30S WEST AND
LOW/MID 40S OUT ON THE ERN PLAINS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY NIGHT)
ISSUED AT 330 AM MST TUE DEC 16 2014
SE WYOMING TERMINALS...VFR CONDITIONS TO PREVAIL AT TERMINALS THIS
MORNING WITH A DRIER AIR MASS OVERHEAD. -SHSN AND MVFR CIGS WILL
RETURN TODAY 18-24Z. WINDS WILL BE SOUTHWEST AT 5 TO 10 KNOTS WITH
LOCALLY HIGHER GUSTS IN THE VICINITY OF KRWL. VFR CONDITIONS RETURN
AFTER 00Z.
WRN NEBRASKA TERMINALS...MAIN CHALLENGE THIS MORNING IS WITH ONGOING
FOG/LOW STRATUS. IFR/LIFR CIGS AND VISIBILITIES WILL CONTINUE AT
MOST WRN NEBRASKA TERMINALS THRU AROUND 18Z...AT WHICH TIME SHOULD
IMPROVE TO MVFR OR EVEN VFR AT KBFF AND KSNY. TIMING OF LIFTING IS
ALWAYS DIFFICULT IN THESE CASES...THOUGH IT LOOKS LIKE KCDR WILL SEE
THE BEST OPPORTUNITY FOR FOG TO HANG IN THE LONGEST TODAY. SHOULD
SEE CONDITIONS SLOWLY IMPROVE BY MIDDAY AND ESPECIALLY DURING THE
AFTERNOON HOURS.
&&
.FIRE WEATHER...
ISSUED AT 330 AM MST TUE DEC 16 2014
NO FIRE WEATHER CONCERNS OVER THE NEXT FEW DAYS. COLD TEMPERATURES
WILL KEEP SNOW COVER ON THE GROUND ACROSS MUCH OF THE REGION.
AFTERNOON HUMIDITY VALUES WILL GENERALLY BE ABOVE 50 PERCENT AND
WINDS WILL BE LIGHT.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...RUBIN
SHORT TERM...ZF
LONG TERM...CAH
AVIATION...CAH
FIRE WEATHER...ZF