Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/15/14
AREA FORECAST DISCUSSION...UPDATED
NWS SAN JOAQUIN VALLEY - HANFORD CA
627 PM PST SUN DEC 14 2014
.UPDATE...
HAVE UPDATED WINDS TO REMOVE VALLEY PORTION OF THE ADVISORY.
STRONGEST WINDS WILL BE CONFINED THROUGH THE GRAPEVINE PASS ALONG
INTERSTATE 5. UPDATED TO REMOVE RAIN CHANCES TONIGHT AND EARLY
TOMORROW.
.SYNOPSIS...
AN APPROACHING STORM SYSTEM WILL BEGIN SPREADING RAIN AND MOUNTAIN
SNOW ACROSS CENTRAL CALIFORNIA ON MONDAY...WITH UNSETTLED WEATHER
CONTINUING THROUGH WEDNESDAY NIGHT. THERE WILL BE A BRIEF BREAK ON
THURSDAY BEFORE ANOTHER CHANCE OF PRECIPITATION BEGINS FRIDAY AND
CONTINUES INTO THE WEEKEND.
&&
.DISCUSSION...
LATEST 00Z RAP AND NAM12 ARE INDICATING THAT THE FRONTAL BOUNDARY
THAT WAS PROJECTED TO MOVE IN HERE OVERNIGHT IS NOW BEGINNING TO
INTERACT WITH AN UPPER TROUGH AND IS FORMING A WAVE ON THE FRONT
THAT IS CAUSING IT TO SLOW DOWN. WARM FRONT HAS PUSHED THROUGH
WITH A FEW SHOWERS IN THE SIERRA EARLIER THIS EVENING.
PATCHY DENSE FOG IS EXPECTED TO DEVELOP IN THE VALLEY WHERE THERE
WAS CLEARING TODAY. WE WILL LOOK AND SEE IF A DENSE FOG ADV WILL
BE NEEDED. RIGHT NOW VISIBILITIES ARE GOOD ACROSS THE VALLEY WITH
SOME MIXING AND MID LEVEL CLOUDS TO KEEP FOG DEVELOPMENT TO A
MINIMUM.
NAM DNG5 WIND GUIDANCE CAME IN WITH A MORE CONCISE AREA OF STRONG
WINDS RIGHT ALONG THE INTERSTATE 5 CORRIDOR. WE HAVE CANCELED THE
WIND ADVISORY FOR THE VALLEY AND ARE FOCUSING MORE ON THE TEJON
PASS IN THE KERN CO MOUNTAINS.
&&
.PREV DISCUSSION... /ISSUED 225 PM PST SUN DEC 14 2014/
DISCUSSION...
SATELLITE AND RADAR LOOPS SHOW MID-LEVEL CLOUDS MOVING OVER THE
SOUTHERN SIERRA NEVADA THIS AFTERNOON. THESE CLOUDS ARE PRODUCING A
FEW SHOWERS...WITH RAWS REPORTING LIGHT PRECIPITATION. HAVE UPDATED
THIS AFTERNOON/S POP/WEATHER/SKY GRIDS TO INCREASE POPS AND CLOUDS
OVER THE SOUTHERN SIERRA NEVADA AND ADD ISOLATED SHOWERS.
SATELLITE LOOPS SHOW A BAND OF HIGH CLOUDS MOVING OVER INTERIOR
CENTRAL CALIFORNIA THIS AFTERNOON. BEHIND THIS BAND IS THE FRONTAL
BAND MARKING THE LOCATION OF THE COLD FRONT ASSOCIATED WITH THE NEXT
STORM. THIS FRONTAL BAND IS ALREADY MOVING ONTO THE NORTHERN
CALIFORNIA COAST. THIS TIMING IS A BIT FASTER THAN YESTERDAY/S
THINKING...BUT IS MORE IN LINE WITH EARLIER MODEL RUNS.
LIGHT PRECIPITATION IS EXPECTED TO REACH WESTERN MERCED COUNTY BY
DAYBREAK...WITH RAIN SPREADING SOUTH THROUGH THE DAY AND SNOW INTO
THE MOUNTAINS. AHEAD OF THE COLD FRONT...STRONG SOUTHERLY WINDS ARE
FORECAST TO DEVELOP OVER THE TEHACHAPI MOUNTAINS AND FUNNEL THROUGH
THE TEJON PASS INTO THE FAR SOUTH END OF THE SAN JOAQUIN VALLEY.
THE SNOW LEVEL WILL START OUT AROUND 5500 FEET MONDAY MORNING...THEN
LOWER TO AROUND 5000 FEET BY MONDAY EVENING. LITTLE CHANGE IS
FORECAST IN SNOW LEVELS THROUGH THE MIDDLE OF THE WEEK.
THE LATEST QPF GUIDANCE CONTINUES TO FORECAST THE HEAVIEST
PRECIPITATION FOR MONDAY NIGHT INTO TUESDAY...FOLLOWED BY A SHORT
BREAK BEFORE THE NEXT STORM ARRIVES LATE TUESDAY NIGHT INTO
WEDNESDAY. THE 21Z /1300 PST/ RFC GUIDANCE HAS THIS SECOND STORM TO
BE AT LEAST AS WET AS THE FIRST SYSTEM...BUT TO DROP ITS
PRECIPITATION IN A SHORTER TIME.
BECAUSE OF THE SHORT BREAK BETWEEN STORMS...THE TWO SYSTEMS CAN BE
TREATED AS THE COMPONENTS OF A SINGLE STORM. THIS WOULD BE
ESPECIALLY TRUE IN THE SOUTHERN SIERRA NEVADA...WHERE THERE LIKELY
WILL ONLY BE A LESSENING IN INTENSITY OF THE SNOW DURING THE SHORT
GAP BETWEEN STORMS.
QPF GUIDANCE CALLS FOR A STORM TOTAL OF 6-12 INCHES NEW SNOW NEAR
YOSEMITE NATIONAL PARK...WITH 4-7 INCHES OVER SEQUOIA PARK. BECAUSE
THESE AMOUNTS WILL BE SPREAD OVER 2.5 DAYS...WINTER WEATHER ADVISORY
CRITERIA WILL NOT BE REACHED. WILL CONTINUE TO COVER THIS SNOW EVENT
WITH A HAZARDOUS WEATHER OUTLOOK.
THE SECOND STORM IS FORECAST TO MOVE EAST OF CALIFORNIA THURSDAY
MORNING...WITH SHORT-WAVE RIDGING RETURNING TO THE STATE. YET A
THIRD SYSTEM IS FORECAST TO REACH THE CALIFORNIA COAST BY MIDDAY
FRIDAY. HOWEVER...AT THIS TIME THE MEDIUM-RANGE MODELS FORECAST THIS
STORM TO HAVE A MORE NORTHERLY TRACK WITH LESS OF AN IMPACT ON
INTERIOR CENTRAL CALIFORNIA THAN THE MONDAY-WEDNESDAY STORMS.
&&
.AVIATION...
SAN JOAQUIN VALLEY...AREAS OF MVFR IN HZ/BR WITH LOCAL IFR AND LIFR
CIGS. MOUNTAINS...TERRAIN BECOMING OBSCURED OVER THE SOUTHERN SIERRA
NEVADA IN LOW CLOUDS AND PRECIPITATION AFTER 18Z MON. OTHERWISE VFR
CONDITIONS WILL PREVAIL FOR THE NEXT 24 HOURS.
.END..
&&
.AIR QUALITY ISSUES...
ON MONDAY DECEMBER 15 2014... FIREPLACE/WOOD STOVE BURNING STATUS
IS: NO BURNING UNLESS REGISTERED IN FRESNO... KERN... MADERA AND
TULARE COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS MEDIUM.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.CLIMATE...
RECORDS
SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR
KFAT 12-14 74:1929 32:1972 52:1922 21:1967
KFAT 12-15 76:1958 39:1963 54:1962 25:1975
KFAT 12-16 70:1958 39:1963 59:1888 25:1967
KBFL 12-14 80:1958 36:1972 53:1950 20:1901
KBFL 12-15 79:1958 40:1992 51:2006 19:1901
KBFL 12-16 77:1976 42:1963 55:1893 22:1901
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 4 AM MONDAY TO 4 AM PST TUESDAY CAZ095.
&&
$$
PUBLIC...JDB
AVN/FW...DS
PREV DISCUSSION...SANGER
SYNOPSIS...BSO
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
603 PM PST SUN DEC 14 2014
.UPDATE...
SNOW BAND HAS EXITED THE SIERRA FRONT AND NOW EXTENDED ACROSS FAR
NORTHEAST CA INTO NORTHWEST NV AND BASIN AND RANGE. SNOWFALL
AMOUNTS HAVE BEEN LIGHT, GENERALLY 1/2-1 INCH, MAINLY ABOVE THE
5000 FOOT ELEVATION LEVEL. LOCALLY HIGHER AMOUNTS OVER FREDONYER
AND YUBA PASS WITH PLUMAS-EUREKA STATE PARK OBSERVING 0.20 INCH
QPF. BAND WILL CONTINUE TO MOVE SLOWLY EAST AND EXIT LATE THIS
EVENING WITH ISOLATED SHOWERS LINGERING OVERNIGHT ALONG THE CREST
AND FAR NORTHEAST CA/NORTHWEST NV. THE HRRR AND OTHER MODEL DATA
WERE INDICATING SOME BREAKS IN THE CLOUDS RIGHT BEHIND THIS BAND
ALTHOUGH CLOUDS WERE APPROACHING UPSTREAM AND THE BREAK WILL BE
SHORTLIVED. THIS CLEARING WAS ALLOWING TEMPS TO FALL TO NEAR OR
BELOW FREEZING WITH PATCHY FREEZING FOG WHERE PRECIPITATION
OCCURRED THIS EVENING. WE HAVE UPDATED THE FORECAST TO SHOW PATCHY
FREEZING FOG. MOTORISTS SHOULD EXERCISE EXTREME CAUTION TONIGHT AS
SLICK ROADWAYS ARE A GOOD POSSIBILITY WHERE ROADS FREEZE AND ARE
NOT TREATED. FOR ELEVATIONS BELOW 5000 FEET, ICY ROADWAYS WILL BE
MORE LOCALIZED AS TEMPS HOVER JUST ABOVE FREEZING FOR MUCH OF THE
NIGHT. HOHMANN
&&
.PREVIOUS DISCUSSION... /ISSUED 423 PM PST SUN DEC 14 2014/
UPDATE...
WARM ADVECTION AHEAD OF OUR MONDAY SYSTEM IS QUITE A BIT STRONGER
THAN MODELS HAD FORECAST WITH LOW-MID LEVEL DRY AIRMASS BEING
OVERCOME IN A SOLID BAND OF SHOWERS OVER NORTHEAST CA AND
NORTHWEST NV. DEWPOINTS WERE IN THE MID 30S AT LOWEST ELEVATIONS
SUCH THAT ACCUMULATION BELOW 5000 FEET IS UNLIKELY BUT ROAD TEMPS
AND DEWPOINTS SUGGEST SOME SNOW MAY BEGIN TO STICK ABOVE 5000 FEET
ESPECIALLY NORTH OF I-80 WHERE DURATION OF SNOWFALL WILL BE
LONGEST. AN INCH OR TWO OF SNOW IS POSSIBLE FROM PLUMAS AND LASSEN
COUNTIES EASTWARD INTO NORTHWEST NV ABOVE 5000 FEET WITH SLICK
ROADS ON AREA PASSES. FOR THE RENO-CARSON CITY AREA, THE BACK EDGE
OF SHOWERS WILL BRING AN ABRUPT END TO THE SHOWERS IN THE NEXT
HOUR OR TWO. SO WE HAVE MAINTAINED AN ISOLATED COVERAGE FOR THIS
EVENING EVEN THOUGH AS OF THIS WRITING, IT WAS SNOWING IN RENO AND
THE NORTH VALLEYS. WE HAVE UPDATED TO BUMP POPS UP FOR AREAS
NORTH AND EAST OF RENO THIS EVENING AS THE BAND WILL LAST FOR
SEVERAL HOURS INTO THE EVENING. HOHMANN
PREVIOUS DISCUSSION... /ISSUED 250 PM PST SUN DEC 14 2014/
SYNOPSIS...
A SERIES OF WEATHER SYSTEMS WILL BRING PERIODS OF SNOW AND RAIN TO
THE SIERRA AND WESTERN NEVADA THIS WEEK. SNOW LEVELS WILL REMAIN
LOW WITH THE POTENTIAL FOR SNOW ACCUMULATIONS ALL THE WAY DOWN TO
THE NEVADA VALLEY FLOORS.
SHORT TERM...
LOW PRESSURE IS APPROACHING THE CALIFORNIA COAST WITH WARM AIR
ADVECTION SHOWERS MOVING ACROSS THE NORTHERN SIERRA. SOME DRY AIR
BELOW RIDGE LEVEL WILL LIMIT PRECIPITATION ACROSS WESTERN NEVADA,
WITH WET ROADS AND AN INCH OR TWO OF SNOW POSSIBLE IN THE SIERRA
INTO THIS EVENING.
MORE SUBSTANTIAL PRECIPITATION WILL REACH THE NORTHERN SIERRA BY
MONDAY AFTERNOON AS THE LOW MOVES INLAND. MODELS ARE SHOWING NEAR
A 0.50 INCH OF LIQUID ALONG THE CREST NORTH OF HIGHWAY 88 MONDAY
AFTERNOON TO MONDAY NIGHT. THIS SHOULD RESULT IN 3-8 INCHES OF
SNOW ALONG THE CREST FROM CARSON PASS TO WESTERN LASSEN COUNTY,
WITH 2-4 INCHES POSSIBLE ALONG THE CREST FOR MONO COUNTY. IN THE
NORTHERN SIERRA EAST OF THE CREST, UP TO 4 INCHES OF ACCUMULATION
IS POSSIBLE. THOSE PLANNING TRAVEL WILL WANT TO BE PREPARED FOR
SLICK ROADS OVER THE SIERRA PASSES MONDAY NIGHT AND EARLY TUESDAY
MORNING.
FOR WESTERN NEVADA, LIGHT RAIN AND SNOW WITH SNOW LEVELS RISING
TO 5000-5500 FEET MONDAY AFTERNOON. IF ADDITIONAL PRECIPITATION
CROSSES THE SIERRA MONDAY NIGHT, SNOW LEVELS WILL DROP DOWN TO
4000-4500 FEET AND LIGHT ACCUMULATIONS COULD OCCUR. HOWEVER MOST
OF THE LIFT AND INSTABILITY APPEARS IT WILL REMAIN OVER NORTHERN
CALIFORNIA, SO CONFIDENCE IS LOW IN SNOW ACCUMULATIONS OVER
WESTERN NEVADA WITH THE FIRST SYSTEM.
A MOIST ONSHORE FLOW WILL CONTINUE FOR TUESDAY WITH SHOWERS
POSSIBLE ALONG THE CREST, BUT LITTLE IF ANY ADDITIONAL
ACCUMULATION. BY WEDNESDAY AS STRONGER AND COLDER SYSTEM MAY
ARRIVE BRINGING THE POTENTIAL FOR UP TO AN INCH OF LIQUID ALONG
THE CREST. THIS SYSTEM HAS QUITE A BIT MORE JET SUPPORT AND COLD
AIR INSTABILITY. HOWEVER MODELS HAVE BEEN INCONSISTENT IN ITS
TRACK SO CONFIDENCE HERE IS LOW TO MEDIUM. BRONG
LONG TERM...THURSDAY THROUGH SUNDAY...
SHORTWAVE RIDGING BECOMES ESTABLISHED ACROSS NORTHERN CALIFORNIA ON
THURSDAY AHEAD OF A LOW PRESSURE SYSTEM THAT LOOKS TO PROVIDE OUR
NEXT CHANCE FOR PRECIPITATION FRIDAY INTO SATURDAY. ONLY MINOR
CHANGES TO THE FORECAST WITH SOME RUN CONSISTENCY ISSUES ARISING
MAINLY IN THE GFS WITH BETTER CONSISTENCY IN THE EC. RECENT RUNS
HAVE DEPICTED ANYTHING FROM A CLOSED LOW ACROSS CENTRAL CALIFORNIA
ON FRIDAY NIGHT TO A MORE INLAND SLIDER TYPE TRAJECTORY IN RECENT
RUNS. HAVE SPREAD HIGHER CHANCES FOR PRECIPITATION FARTHER EASTWARD
ACROSS THE WESTERN NEVADA BASIN AND RANGE WITH A TREND TOWARDS AN
EASTERN MORE TRAJECTORY IN THE GFS.
THOUGH DIFFERENCES IN SYSTEM CHARACTERISTICS EXIST THE TIMING OF THE
EVENT REMAINS GOOD WITH ABOUT A 24 HOUR WINDOW FOR SNOWFALL ACROSS
THE SIERRA AND WESTERN NEVADA FRIDAY AFTERNOON INTO SATURDAY
MORNING. SNOW LEVELS COULD LOWER ENOUGH TO SEE SNOW ACROSS WESTERN
NEVADA FOOTHILLS AND POSSIBLY VALLEY FLOORS BUT THIS WILL BE
ADJUSTED BASED ON THE TRAJECTORY OF THE LOW. THIS FAST MOVING SYSTEM
DOES NOT LOOK TO BE A HEAVY SNOW PRODUCER IN THE SIERRA BUT STILL
MAY PUT DOWN SEVERAL INCHES OF SNOWFALL WHICH COULD RESULT IN TRAVEL
IMPACTS AND SLOW DOWNS. BY SATURDAY AND SUNDAY MOST MEDIUM RANGE
MODELS DEVELOP A CLOSED LOW ACROSS AZ/NM WITH A DRIER PATTERN
BECOMING ESTABLISHED AS A RIDGE FORMS ACROSS THE WEST COAST. FUENTES
AVIATION...
A LOW PRESSURE SYSTEM WILL APPROACH THE WEST COAST THIS EVENING WITH
CHANCES FOR SIERRA SNOWFALL AND A MIX OF RAIN AND SNOW FOR WESTERN
NEVADA TERMINALS. -SHSN POSSIBLE AFTER ABOUT 15Z MONDAY FOR KTRK AND
KTVL WITH PERIODS OF IFR CONDITIONS AND MOUNTAIN TOP OBSCURATION
EXPECTED. A HEAVIER PERIOD OF PRECIPITATION LOOKS TO MOVE IN AFTER 00Z
TUESDAY WITH 1-3" OF RUNWAY ACCUMULATION POSSIBLE AT KTRK/KTVL/KMMH
THRU TUESDAY MORNING. MAINLY LIGHT RAINFALL EXPECTED FOR KRNO/KCXP
MONDAY AFTERNOON WITH A MIX OF RAIN AND SNOW POSSIBLE TUESDAY NIGHT.
WINDS DO NOT LOOK PARTICULARLY STRONG FOR THIS SYSTEM BUT AREAS OF
TURBULENCE POSSIBLE ALONG THE SIERRA WITH GUSTS OVER 40KTS EXPECTED.
FUENTES
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
922 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 03Z...
* LIFR CIGS LIKELY TO PERSIST INTO THE OVERNIGHT AND POTENTIALLY
INTO EARLY SUNDAY MORNING
* IFR VSBY WITH DRIZZLE AND FOG LIKELY WITH SOME POTENTIAL FOR
LIFR VSBY OVERNIGHT
* SOUTH WINDS WILL INCREASINGLY GO MORE SOUTHEASTERLY SUNDAY
MORNING AROUND 10-12KT
IZZI
//DISCUSSION...UPDATED 03Z...
PREVIOUS TAFS LARGELY WORKING OUT WELL THOUGH CIGS DID FALL A BIT
QUICKER THAN PREVIOUSLY THOUGHT. ANTICIPATE CIGS TO HOLD IN THE
002-003 RANGE THROUGH MOST OF THE NIGHT. NOT OUT OF THE QUESTION
THAT WE COULD DROP TO THE DECK WITH DENSE FOG DEVELOPING THOUGH
WITH WINDS STAYING 8-10KT AND OCNL DZ AM THINKING THAT WE MAY HOLD
GENERALLY FAIRLY STEADY WHERE WE ARE NOW. UNFORTUNATELY MDW CIGS
WILL BE HOVERING RIGHT AROUND AIRPORT MINS AND TOO CLOSE OF A CALL
AT THIS POINT WHETHER WE WILL BE JUST ABOVE OR JUST BELOW MINS
EARLY MONDAY MORNING.
IZZI
UPDATED 00Z...
STRATUS AND LIGHT FOG CONTINUE TO BLANKET THE REGION EARLY THIS
EVENING WITH IFR/LIFR CIGS THE RULE. BIG QUESTION FOR TONIGHT WILL
BE HOW DO CIGS/VSBY TREND THROUGH THE NIGHT. LOSS OF DAYLIGHT
WOULD TEND TO FAVOR THE LOSS OF A DEGREE OR TWO IN TEMPS WHICH
WOULD LIKELY ALLOW CIGS/VSBY TO FURTHER TREND DOWNWARD. MUCH OF
THE GUIDANCE SUGGESTS THIS WILL BE THE CASE THIS EVENING...THOUGH
BY LATER TONIGHT GUIDANCE DIVERGES WITH SEVERAL MODELS SUGGESTING
IMPROVEMENT AS SOUTHEAST WINDS INCREASE. HAVE OPTED TO GRADUALLY
TREND CONDITIONS LOWER TONIGHT AND THEN SHOW A FAIRLY QUICK
IMPROVEMENT EARLY MONDAY MORNING. POSSIBILITIES OF HOW TONIGHT
PLAYS OUT RUN THE GAMUT FROM A QUICK DROP TO DENSE FOG AND CIGS
ON THE DECK TO POTENTIALLY STEADY STATE CONDITIONS THROUGH THE
NIGHT WITH A SLIGHT IMPROVEMENT LATE. NEEDLESS TO SAY CONFIDENCE
IS NOT HIGH WITH RESPECT TO THE DETAILS TONIGHT AND MONDAY.
BAND OF SHOWERS SHOULD MOVE THROUGH THE REGION MONDAY
MIDDAY/AFTERNOON AS STORM SYSTEM APPROACHES FROM THE SOUTHWEST.
INITIALLY LIKELY TO SEE SOME IMPROVEMENT IN VSBY/CIGS MONDAY
BUT IN THE WAKE OF THE INITIAL BAND OF SHOWERS WOULD EXPECT
CONDITIONS TO ONCE AGAIN TREND DOWNWARD WITH LIGHT RAIN OR
DRIZZLE CONTINUING THROUGH MONDAY EVENING.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH CONFIDENCE IN LIFR CIGS THROUGH MOST OF THE NIGHT...LOWER
CONFIDENCE ON WHEN CIGS LIFT TO IFR OR MVFR MONDAY
* MEDIUM-HIGH CONFIDENCE IN TIMING OF ONSET OF SHOWERS MONDAY
* MEDIUM CONFIDENCE IN CIGS/VSBY TRENDING BACK DOWNWARD LATE
MONDAY AFTERNOON AND EVENING
* HIGH CONFIDENCE IN WIND TRENDS
IZZI
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...MVFR LIKELY...IFR POSSIBLE. CHANCE OF RAIN...POSSIBLY
MIXING WITH WET SNOW BEFORE ENDING.
WEDNESDAY...MVFR CIGS POSSIBLE...ESPECIALLY EARLY.
THURSDAY THROUGH SATURDAY...PRIMARILY VFR.
IZZI
&&
.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...DENSE FOG ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032 UNTIL 8 AM MONDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565
UNTIL 9 AM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
850 PM CST Sun Dec 14 2014
.UPDATE...
ISSUED AT 840 PM CST SUN DEC 14 2014
Issued a Dense Fog Advisory earlier this evening across northern
portions of the forecast area where fairly widespread 1/4SM mile
visibilities had developed. The advisory currently runs until 8 AM
Monday, but if recent trends persist, it may be able to be
canceled early.
A vertically stacked low pressure system is centered over the
central Plains this evening, with a band of showers on its eastern
periphery. These showers will eventually arrive in the forecast
area by late tonight or during the day Monday, but they will not
be breaking speed record getting here given the vertically stacked
nature of the system. In any event, the pressure gradient will
gradually increase with the approach of the system, resulting in
increased wind speeds. These increased winds, along with a
slightly drier airmass that precedes the rain area, may help to
diminish the fog across the area as the night progresses. This
gradual diminishing should also preclude the need for an expanded
Dense Fog Advisory, and may allow the early cancellation of the
current one.
Aside from the previous need to add the Fog Advisory, going
forecast is in pretty good shape. Plan to make a few tweaks for
the latest trends, but no significant changes are needed at this
time.
&&
.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 vsbys 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 00Z TAFS through 00Z Monday evening)
ISSUED AT 556 PM CST SUN DEC 14 2014
Widespread IFR or lower conditions expected across the central
Illinois terminals through the night. Some improvement is expected
on Monday as a storm system lifting though the Midwest brings
light rain and increasing wind speeds. However, it may be Tuesday
before conditions improve to MVFR or better.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY until 8 AM CST Monday FOR ILZ027>031-036>038.
&&
$$
UPDATE...Bak
SHORT TERM...Barnes
LONG TERM...Smith
AVIATION...Bak
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
619 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 00Z...
* IFR CONDITIONS LIKELY TO GRADUALLY LOWER TO LIFR TONIGHT BEFORE
LIFTING AGAIN LATE TONIGHT AND SUNDAY
* CIGS/VSBY PROBABLY LOWERING AGAIN TO IFR OR POSSIBLY LIFR SUNDAY
EVENING
* SOUTH WINDS WILL INCREASINGLY GO MORE SOUTHEASTERLY SUNDAY
MORNING AROUND 10KT
IZZI
//DISCUSSION...UPDATED 00Z...
STRATUS AND LIGHT FOG CONTINUE TO BLANKET THE REGION EARLY THIS
EVENING WITH IFR/LIFR CIGS THE RULE. BIG QUESTION FOR TONIGHT WILL
BE HOW DO CIGS/VSBY TREND THROUGH THE NIGHT. LOSS OF DAYLIGHT
WOULD TEND TO FAVOR THE LOSS OF A DEGREE OR TWO IN TEMPS WHICH
WOULD LIKELY ALLOW CIGS/VSBY TO FURTHER TREND DOWNWARD. MUCH OF
THE GUIDANCE SUGGESTS THIS WILL BE THE CASE THIS EVENING...THOUGH
BY LATER TONIGHT GUIDANCE DIVERGES WITH SEVERAL MODELS SUGGESTING
IMPROVEMENT AS SOUTHEAST WINDS INCREASE. HAVE OPTED TO GRADUALLY
TREND CONDITIONS LOWER TONIGHT AND THEN SHOW A FAIRLY QUICK
IMPROVEMENT EARLY MONDAY MORNING. POSSIBILITIES OF HOW TONIGHT
PLAYS OUT RUN THE GAMUT FROM A QUICK DROP TO DENSE FOG AND CIGS
ON THE DECK TO POTENTIALLY STEADY STATE CONDITIONS THROUGH THE
NIGHT WITH A SLIGHT IMPROVEMENT LATE. NEEDLESS TO SAY CONFIDENCE
IS NOT HIGH WITH RESPECT TO THE DETAILS TONIGHT AND MONDAY.
BAND OF SHOWERS SHOULD MOVE THROUGH THE REGION MONDAY
MIDDAY/AFTERNOON AS STORM SYSTEM APPROACHES FROM THE SOUTHWEST.
INITIALLY LIKELY TO SEE SOME IMPROVEMENT IN VSBY/CIGS MONDAY
BUT IN THE WAKE OF THE INITIAL BAND OF SHOWERS WOULD EXPECT
CONDITIONS TO ONCE AGAIN TREND DOWNWARD WITH LIGHT RAIN OR
DRIZZLE CONTINUING THROUGH MONDAY EVENING.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH CONFIDENCE IN IFR OR LOWER CONDITIONS THROUGH EARLY SUNDAY
MORNING...BUT LOW CONFIDENCE IN HOW LOW AND PRECISE TRENDS
* MEDIUM-HIGH CONFIDENCE IN TIMING OF ONSET OF SHOWERS MONDAY
* MEDIUM CONFIDENCE IN CIGS/VSBY TRENDING BACK DOWNWARD LATE
MONDAY AFTERNOON AND EVENING
* HIGH CONFIDENCE IN WIND TRENDS
IZZI
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...MVFR LIKELY...IFR POSSIBLE. CHANCE OF RAIN...POSSIBLY
MIXING WITH WET SNOW BEFORE ENDING.
WEDNESDAY...MVFR CIGS POSSIBLE...ESPECIALLY EARLY.
THURSDAY THROUGH SATURDAY...PRIMARILY VFR.
IZZI
&&
.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.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
600 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 vsbys 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 00Z TAFS through 00Z Monday evening)
ISSUED AT 556 PM CST SUN DEC 14 2014
Widespread IFR or lower conditions expected across the central
Illinois terminals through the night. Some improvement is expected
on Monday as a storm system lifting though the Midwest brings
light rain and increasing wind speeds. However, it may be Tuesday
before conditions improve to MVFR or better.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Smith
AVIATION...Bak
AREA FORECAST DISCUSSION
NWS GOODLAND KS
518 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 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 457 PM MST SUN DEC 14 2014
LIFR CONDITIONS WILL CONTINUE AT KGLD UNTIL MONDAY MORNING AS THE
STORM SYSTEM STARTS EXITING THE AREA. CIGS AND VISIBILITIES WILL
IMPROVE AFTER 12Z TO MVFR WITH VFR EXPECTED DURING THE AFTERNOON.
KMCK WILL CONTINUE VFR THIS EVENING AS THE DRY SLOT CONTINUES TO
WRAP INTO THE EASTERN SIDE OF THE LOW. BY 09Z THE FORECAST
SOUNDING FOR KMCK SATURATES ENOUGH FOR CIGS TO LOWER AND LIGHT
SNOW TO BEGIN. HOWEVER PRECIPITATION SHOULD BE SHORT-LIVED AS THE
LOW STARTS MOVING OUT OF THE AREA BY LATE MORNING WITH CONDITIONS
IMPROVING TO MVFR. VFR CONDIITONS ARE EXPECTED MONDAY AFTERNOON.
&&
.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...FS
AREA FORECAST DISCUSSION
NWS GAYLORD MI
939 PM EST SUN DEC 14 2014
.UPDATE...
ISSUED AT 939 PM EST SUN DEC 14 2014
MANY OBS REPORTING DENSE FOG THROUGHOUT THE EVENING...THUS THE
ISSUANCE OF A DENSE FOG ADVISORY EARLY THIS EVENING IN
COORDINATION WITH MQT. NARROW BAND OF HEAVIER DRIZZLE/POSSIBLY
LIGHT RAIN STEADILY LIFTS NE THRU NRN LWR MICHIGAN...CURRENTLY
POSITIONED FROM CVX TO GLR TO WEST BRANCH...LIKELY DRIVEN BY A
WEAK WARM FRONTAL BOUNDARY. DESPITE THE BAND OF SLIGHTLY HEAVIER
PRECIP...WILL STICK WITH PERIODS OF DRIZZLE FOR THE BALANCE OF THE
NIGHT. WILL CERTAINLY MAINTAIN THE DENSE FOG ADVISORY AS WELL
GIVEN CURRENT OBS.
&&
.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...DENSE FOG ADVISORY UNTIL 11 AM EST MONDAY FOR MIZ008-015>036-041-
042.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...MLR
SHORT TERM...MSB
SHORT TERM...MSB
LONG TERM...ALM
AVIATION...MLR
MARINE...ADAM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
625 PM EST SUN DEC 14 2014
LATEST UPDATE...
AVIATION
.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 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 624 PM EST SUN DEC 14 2014
THE LAST TWO NIGHTS HAVE SEEN CONDITIONS ACTUALLY IMPROVE AFTER
DARK AND TONIGHT SEEMS TO BE FOLLOWING THAT TREND WITH MVFR
CONDITIONS PREVAILING AT MOST PLACES ALONG WITH SOME PATCHY IFR.
WENT WITH PREVAILING CONDITIONS FOR THIS EVENING...THEN BROUGHT
MORE IFR/LIFR IN LATER TONIGHT. SOUTHWEST TO SOUTH WINDS SHOULD
REMAIN BLO 10 KNOTS OVERNIGHT.
&&
.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...OSTUNO
HYDROLOGY...JAM
MARINE...WDM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
855 PM EST SUN DEC 14 2014
.SYNOPSIS...
DESPITE HIGH PRESSURE BUILDING ACROSS THE NORTH
COUNTRY...A TEMPERATURE INVERSION HAS TRAPPED THE CLOUDS AT
LOCATIONS BELOW 4000 FEET AND THAT WILL CONTINUE THROUGH TUESDAY BUT
WITH INCREASING BREAKS IN THE CLOUDS. ON ITS HEELS...A LOW PRESSURE
SYSTEM WILL MOVE INTO THE AREA TUESDAY NIGHT AND WEDNESDAY AND BRING
A CHANCE FOR A LIGHT WINTRY MIX AT THE ONSET TUESDAY NIGHT THEN RAIN
AND SNOW SHOWERS AS A WEAK COLD FRONT PASSES THROUGH THE NORTH
COUNTRY ON WEDNESDAY.
&&
.NEAR TERM /UNTIL 7 AM MONDAY MORNING/...
AS OF 855 PM EST SUNDAY...FORECAST HOLDING UP WELL. LOW OVERCAST
CONTINUES ACROSS THE NORTH COUNTRY AS RH REMAINS TRAPPED UNDER
STRONG INVERSION. THAT INVERSION WILL HOLD TOUGH THIS EVENING
LOCKING IN OVERCAST AND KEEPING TEMPERATURES FROM FALLING MUCH AT
ALL. THERE ARE A FEW SNOW SHOWERS PER OBSERVATIONS ACROSS THE
OTTAWA VALLEY ASSOCIATED WITH WEAK/SHEARED VORT MAX OVER SOUTHWEST
QUEBEC/EASTERN ONTARIO. THESE SNOW SHOWERS WILL REMAIN TO THE
NORTH OF THE NORTH COUNTRY AS UPPER RIDGING BUILDS EASTWARD.
AGAIN, ONLY LOOKING AT A FEW FLURRIES IN CHAMPLAIN VALLEY BUT
LARGELY DRY ELSEWHERE. LOWS IN THE 20S STILL LOOK GOOD.
PREVIOUS NEAR-TERM DISCUSSION ISSUED AT 621 PM EST SUNDAY FOLLOWS...
FORECAST GENERALLY HOLDING UP. I DID ADD OCCASIONAL FLURRIES
ALONG THE CHAMPLAIN VALLEY AND ALONG LAKE CHAMPLAIN. THOUGH A
STOUT INVERSION EXISTS, I NOTICED ON 21Z RAP FORECAST SOUNDINGS
THAT LAPSE RATES BELOW THE INVERSION ARE AT LEAST WEAKLY UNSTABLE
AND ALREADY SATURATED. IT SHOULD BE JUST ENOUGH TO WRING OUT SOME
OCCASIONAL FLURRIES WITH NO ACCUMULATIONS.
OTHERWISE...I`VE OPTED TO RAISE TEMPS AND DEW POINTS OVERNIGHT
GIVEN PROJECTED OVERCAST SKIES. LOWS TO REMAIN MOSTLY IN THE MID
TO UPPER 20S.
&&
.SHORT TERM /7 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 228 PM EST SUNDAY...THE BROAD RIDGE OF HIGH PRESSURE WILL
CONTINUE TO BUILD INTO THE REGION MONDAY MORNING. HOWEVER...LOOK
UPSTREAM ON SATELLITE PICTURES AND IT TELLS THE DREARY STORY.
THE SURFACE INVERSION WILL CONTINUE TO TRAP A SHALLOW LAYER OF
PARTIALLY SATURATED AIR AT THE NEAR SURFACE WHICH WILL KEEP A
STRATUS DECK OVER MUCH OF THE AREA THROUGH TUESDAY MORNING BUT WITH
INCREASING BREAKS AS TIME PASSES.
GUIDANCE SHOWS THE INVERSION FINALLY BEGINS TO MIX TUESDAY MORNING
INTO TUESDAY AFTERNOON AS WE TRANSITION FROM NORTHERLY FLOW TO
SOUTHERLY FLOW BEHIND THE RIDGE. THE INCREASED CLOUD COVER WILL
WEAKEN THE AMOUNT OF DAYTIME HEATING BUT EXPECT A WEAK WARMING TREND
INTO THE MID TO UPPER 30S BY TUESDAY AFTERNOON BEFORE GIVING WAY TO
A COLD FRONT WITH AN ASSOCIATE LOW PRESSURE SYSTEM.
TUESDAY AFTERNOON/EVENING A MATURE LOW PRESSURE SYSTEM...REMNANTS OF
CALIFORNIA STORM...WITH NEGATIVE TILTED TROUGH WILL BEGIN TO PASS
THROUGH THE REGION.
RIGHT NOW THERMAL PROFILES FROM ALL MODELS SHOW THE POTENTIAL FOR A
MIXED PRECIPITATION EVENT AT THE ONSET. INITIALLY...IT STARTS
REAL WARM DUE TO STRONG SUBSIDENCE INVERSION WITH H85 TEMPS +5-6C
BUT AS MOISTURE RETURNS AND COOLS THE LAYER...TEMPERATURES ALOFT
AND SURFACE WILL BE MARGINAL WITHIN 1C EITHER SIDE OF 0C AND COLD
NOT DEEP ENOUGH TO INITIALLY SUPPORT ICE CRYSTALS...NOT CONDUCIVE
TO SNOW BUT FREEZING RAIN/RAIN.
QPF TOTALS FOR THE SYSTEM ARE ON THE LOWER SIDE WITH AREAS EXPECTING
TO SEE BETWEEN A 0.10" TO 0.25" IN THE HIGHER TERRAIN OF THE
ADIRONDACKS. A MINIMAL GLAZE EXPECTED...JUST A FEW HUNDRETHS OF ICE
ACCUMULATION AND QUICKLY CHANGING TO RAIN SHOWERS AND COOLING ALOFT
FOR MOUNTAIN SNOW SHOWERS.
THERE IS SOME CONCERN ON WHETHER THE SNOW THAT REMAINS ON TREES AS
OF SUNDAY AFTERNOON WILL STILL BE THERE FOR THIS EVENT. MY BEST
GUESS IS SOMEWHAT BUT AS EACH DAY WILL LIKELY LOSE A BIT MORE AND
THEN WHAT LITTLE IN ADDITIONAL PRECIPITATION I WOULDN`T THINK IT
POSES ANY NEW PROBLEMS.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 255 PM EST SUNDAY...UPPER LEVEL SHORTWAVE MOVES THROUGH THE
REGION EARLY WEDNESDAY. SURFACE LOW MOVING UP THROUGH SAINT
LAWRENCE VALLEY WHILE WEAK SECONDARY MOVES UP ALONG THE NEW
ENGLAND COAST. THE RESULT WILL BE A CONTINUATION OF SNOW/RAIN
SHOWERS DURING THE DAY ON WEDNESDAY. TEMPERATURE PROFILES SUPPORT
MAINLY RAIN IN THE VALLEYS WHERE HIGHS WILL BE IN THE MID 30S TO
AROUND 40...AND SNOW OVER THE HIGHER ELEVATIONS. QPF NOT ALL THAT
GREAT HOWEVER WITH GENERALLY A QUARTER INCH OR LESS EXPECTED.
WITH PASSAGE OF SURFACE LOWS AND ASSOCIATED COLD FRONT...THE
THREAT OF RAIN/SNOW SHOWERS TRANSITIONING TO JUST SNOW SHOWERS
CONTINUES WEDNESDAY NIGHT INTO THURSDAY NIGHT AS UPPER LOW MOVES
ACROSS THE REGION. ACTIVITY BECOMES MORE OROGRAPHIC IN NATURE
DURING THIS PERIOD DUE DEVELOPING NORTHWEST FLOW. AS TROUGH MOVES
EAST ON FRIDAY...DRIER CONDITIONS EXPECTED WITH JUST A FEW
LINGERING MOUNTAINS SNOW SHOWERS OR FLURRIES. RIDGE OF HIGH
PRESSURE BRINGS SOME CLEARING AND DRIER CONDITIONS FRIDAY NIGHT
INTO SATURDAY. BOTH ECMWF AND GFS THEN INDICATE CHANCE FOR SNOW OR
MIXED PRECIPITATION LATER SATURDAY NIGHT INTO SUNDAY AS UPPER TROUGH
AND ASSOCIATED SURFACE LOW LIFT NORTHEAST FROM TENNESSEE VALLEY.
RATHER SIGNIFICANT DIFFERENCES BETWEEN THE TWO MODELS REGARDING
THE DETAILS HOWEVER...SO HAVE JUST GONE WITH 30-40 PERCENT CHANCE
OF PRECIPITATION AT THIS TIME.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
THROUGH 00Z TUESDAY...MVFR CEILINGS EXPECTED THROUGH THE ENTIRE
PERIOD. THERE MAY BE SOME LIGHT FLURRIES FROM TIME TO TIME THROUGH
12Z...BUT VISIBILITIES WILL REMAIN IN THE VFR CATEGORY FOR THE
ENTIRE PERIOD. WINDS WILL BE LIGHT AND VARIABLE THROUGH THE PERIOD
AS WELL.
OUTLOOK 00Z TUESDAY THROUGH FRIDAY...
00Z TUE-18Z TUE...MVFR TRENDING VFR WITH DRY WEATHER EXPECTED.
18Z TUE-00Z FRI...MVFR WITH PERIODS OF IFR EXPECTED DUE TO
SNOW/RAIN SHOWERS ASSOCIATED WITH AREA OF LOW PRESSURE AND
ASSOCIATED FRONTAL SYSTEM.
00Z FRI-00Z SAT...SOME MVFR IN SNOW SHOWERS AT MPV/SLK BUT
ELSEWHERE EXPECT IMPROVEMENT TO VFR.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLW
NEAR TERM...LOCONTO/SLW
SHORT TERM...SLW
LONG TERM...RJS
AVIATION...EVENSON/RJS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1017 PM EST SUN DEC 14 2014
.SYNOPSIS...
LOW CLOUDS THROUGH EARLY MONDAY. COLD FRONT BRINGS RAIN SHOWERS
MONDAY NIGHT INTO TUESDAY...WITH A CHANCE OF SHOWERS BEHIND THE
SYSTEM INTO WEDNESDAY. ANOTHER LOW APPROACHES FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
1015 PM UPDATE...
FORECAST IN GOOD SHAPE. BEGINNING TO SEE VERY LOW CLOUD BASES AND
FG SHOW UP IN THE MOUNTAINS...ESPECIALLY ON THE W SLOPES.
700 PM UPDATE...
NOT MUCH IN THE WAY OF CHANGES TO THE FORECAST FOR THIS EVENING.
STILL EXPECT SOME PATCHY DZ ON THE W SLOPES OF THE N MOUNTAINS.
ALSO EXPECTING SOME FG ALL THE WAY DOWN THE W SPINE OF THE
MOUNTAINS THRU SW VA OVERNIGHT...WHERE LOW CIGS WILL PERSIST.
THE LOW LEVEL FLOW WILL BEGIN TO SWING AROUND TO THE E AND THEN
SE LATE TONIGHT AND EARLY MORNING. THIS SHOULD FINALLY BEGIN TO
ERADICATE THIS LOW STRATUS...FIRST ACROSS SW VA AND SE WV WHERE
LOW TEMPS MAY DO A LAST MINUTE CRASH TO BLO FRZ. HRRR AND RUC ARE
HINTING AT THIS. THINK FROM I64 CORRIDOR AND PTS N WILL HAVE A
HARD TIME DROPPING MUCH TONIGHT...GENERALLY INTO THE UPR 30S.
SHOULD THE CLEARING WORK IN FASTER DURING THE PREDAWN...THEN CRW
TO HTS WILL EXPERIENCE A QUICK DROP IN TEMPS AND PSBL DENSE FG.
THE CLEARING WILL CONTINUE TO PROGRESS N AND W AS THE DAY
PROGRESSES...SUCH THAT MOST PLACES WILL SEE SUN. MAY TAKE UNTIL
AFTERNOON FOR SE OH/N WV THOUGH. WITH DOWNSLOPE SE
FLOW...INCORPORATED THE TYPICAL SPIKE IN TEMPS JUST E OF I79
CORRIDOR...GOING WELL INTO THE 50S...PERHAPS UPR 50S.
PREVIOUS DISCUSSION BELOW...
5H RIDGE AXIS SLIDES ACROSS THE GREAT LAKES AND CENTRAL
APPALACHIAN STATES OVERNIGHT AS SUBSIDENCE INVERSION CONTINUE TO
DOMINATE OUR STAGNANT WEATHER PATTERN. WAA TO CONTINUE AT THE
LOWEST LEVELS AND THIS WILL HELP TO LIFT CLOUD LAYER SOME AND IT
SHOULD ALSO LESSEN OUR CHANCES FOR DRIZZLE FORMATION WITH SLIGHT
DRYING AND WARMING OF OF THE LOWER ATMOSPHERIC COLUMN. OUR
FREEZING FOG-FREEZING RAIN POTENTIAL WILL BE GREATLY DIMINISHED.
HAVE INVERSION LIFTING SOME ON MONDAY...ENOUGH TO BREAKUP TO 100
PERCENT VALUES WE HAVE BEEN RUNNING IN OUR SKY GRIDS THE PAST FEW
DAYS...MAINLY OVER THE SOUTHERN COALFIELDS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
MODELS IN BETTER AGREEMENT TODAY WITH THE PRECIPITATION BAND
ASSOCIATED WITH A COLD FRONT. THEREFORE WILL RAISE POPS MONDAY NIGHT
INTO TUESDAY SOME. BEHIND THE FRONT TUESDAY AFTERNOON...THE BOUNDARY
LAYER BECOMES CONVECTIVELY UNSTABLE...SO WILL ALLOW FOR AN INCREASE
IN SHOWERS DURING THE AFTERNOON.
PLENTY OF MOISTURE LINGERS BEHIND THE SYSTEM...BUT TEMPERATURES DO
NOT APPEAR TO BE COLD ENOUGH TO SUPPORT ICE CRYSTAL GROWTH UNTIL
POSSIBLY LATE WEDNESDAY. THEREFORE WENT WITH MORE OF A
DRIZZLE/FREEZING DRIZZLE SCENARIO LATE TUESDAY NIGHT INTO
WEDNESDAY...BEFORE ALLOWING RAIN OR SNOW LATE WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE PERIOD STARTS WITH HORIZONTAL FLOW ALOFT. H850 FREEZING LINE
LIES SOUTH OF THE AREA WHILE THE MINUS 5C DEGREES ACROSS OUR
NORTHERN BORDER THROUGH 12Z WEDNESDAY NIGHT. THIS TRANSLATES IN TO
MAINLY DRY WEATHER WILL COOL NIGHTS AND SEASONAL AFTERNOONS THROUGH
THURSDAY NIGHT.
THE LOW PRESSURE SYSTEM LIFTS NORTHEAST ACROSS TN AND KY INTO
WV...TO BRING PERIODS OF RAIN DURING THE AFTERNOONS FRIDAY AND
SATURDAY...TRANSITIONING INTO WINTRY MIX OR SNOW FRIDAY NIGHT..AS
THEY SPREAD FROM SOUTH TO NORTH.
BOTH THE GFS AND ECMWF SHOW THE SAME TIMING IN THEIR QPF FIELDS.
ALTHOUGH THE GFS TAKES THE LOW PRESSURE OVER THE OH VALLEY MOVING
NORTHEAST INTO NORTHERN WV...WHILE THE ECMWF TRAJECTORY IS FURTHER
SOUTH AND EAST INTO SATURDAY NIGHT. HOWEVER...THE ECMWF BRINGS
STRONGER FORCING WITH A NEGATIVELY TILTED TROF AT H500 THAN THE
GFS AND CMC FOR SATURDAY. KEPT LIKELY POPS ACROSS THE SOUTH AND
CENTRAL WV...AND EASTERN MOUNTAINS THROUGH SATURDAY EVENING.
WENT WITH A BLEND OF THE ECMWF AD HPC GUIDANCE FOR SEASONAL
TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
SUBSIDENCE INVERSION FINALLY SHOWING SIGNS OF BREAKING UP LATER IN
THE TAF PERIOD. UNTIL THEN...WE ARE ENCASED IN A QUASI STEADY-STATE
REGIME OF LIGHT WINDS AND LOW CLOUDS...WITH CIG VALUES GENERALLY
CONTROLLED BY THE MIXING HEIGHT AND ITS DIURNAL CHANGES.
SAT IMAGERY SHOW STRATOCU DECK COVER MOST OF WV AND STRETCHING BACK
ACROSS OH AND KY AND TN. SEEING CIGS IN THE 2-2.5K FOOT RANGE FOR
TONIGHT FOR RIVER SITES...WITH ELEVATED MOUNTAIN VALLEY SITES
IN LOWER CIGS. CKB PROBABLY WILL HOLD THE LOW END IFR CIGS ALL
NIGHT...ALONG WITH A LOWERING OF VSBY INTO THE 1 TO 2 SM RANGE.
HAVE SOME IFR FG KEKN AND ESPECIALLY KBKW LATE TONIGHT.
THE LOW LEVEL FLOW WILL SWING AROUND TO THE E AND THEN SE DURING
THE MORNING HRS. THIS WILL FINALLY ERADICATE THE LOW
STRATUS...FIRST ACROSS SW VA AND SE WV AROUND DAWN. THIS MAY MAKE
IT INTO KBKW BY 12Z. SHOULD THIS END UP BEING FAST THAN CURRENTLY
FCST...THEN KHTS/KCRW MAY SCT OUT AROUND DAWN WHICH WOULD RESULT
IN SOME DENSE RIVER FG.
THE SCT OF STRATUS WILL CONTINUE THE N TREND AS THE DAY
PROGRESSES WITH KHTS/KCRW/KEKN SCT OUT AROUND 15Z. THINK SE OH AND
N WV INCLUDING KPKB WILL HOLD UNTIL PERHAPS 20Z.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TONIGHT MAY SEE LESS IFR OR WORSE FG FOR
KEKN/KBKW.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 12/15/14
UTC 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
EST 1HRLY 21 22 23 00 01 02 03 04 05 06 07 08
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H M M M M M M M L L L L
EKN CONSISTENCY L L L L L L L M M L L M
PKB CONSISTENCY H H H H H H H H H H M H
CKB CONSISTENCY H H H H H M M M M M M M
AFTER 00Z TUESDAY...
IFR POSSIBLE IN CLOUDS IN THE MOUNTAINS TUESDAY NIGHT INTO
WEDNESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KMC/ARJ/RPY
NEAR TERM...KMC/30
SHORT TERM...RPY
LONG TERM...ARJ
AVIATION...KMC/30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
712 PM EST SUN DEC 14 2014
.SYNOPSIS...
LOW CLOUDS THROUGH EARLY MONDAY. COLD FRONT BRINGS RAIN SHOWERS
MONDAY NIGHT INTO TUESDAY...WITH A CHANCE OF SHOWERS BEHIND THE
SYSTEM INTO WEDNESDAY. ANOTHER LOW APPROACHES FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
700 PM UPDATE...
NOT MUCH IN THE WAY OF CHANGES TO THE FORECAST FOR THIS EVENING.
STILL EXPECT SOME PATCHY DZ ON THE W SLOPES OF THE N MOUNTAINS.
ALSO EXPECTING SOME FG ALL THE WAY DOWN THE W SPINE OF THE
MOUNTAINS THRU SW VA OVERNIGHT...WHERE LOW CIGS WILL PERSIST.
THE LOW LEVEL FLOW WILL BEGIN TO SWING AROUND TO THE E AND THEN
SE LATE TONIGHT AND EARLY MORNING. THIS SHOULD FINALLY BEGIN TO
ERADICATE THIS LOW STRATUS...FIRST ACROSS SW VA AND SE WV WHERE
LOW TEMPS MAY DO A LAST MINUTE CRASH TO BLO FRZ. HRRR AND RUC ARE
HINTING AT THIS. THINK FROM I64 CORRIDOR AND PTS N WILL HAVE A
HARD TIME DROPPING MUCH TONIGHT...GENERALLY INTO THE UPR 30S.
SHOULD THE CLEARING WORK IN FASTER DURING THE PREDAWN...THEN CRW
TO HTS WILL EXPERIENCE A QUICK DROP IN TEMPS AND PSBL DENSE FG.
THE CLEARING WILL CONTINUE TO PROGRESS N AND W AS THE DAY
PROGRESSES...SUCH THAT MOST PLACES WILL SEE SUN. MAY TAKE UNTIL
AFTERNOON FOR SE OH/N WV THOUGH. WITH DOWNSLOPE SE
FLOW...INCORPORATED THE TYPICAL SPIKE IN TEMPS JUST E OF I79
CORRIDOR...GOING WELL INTO THE 50S...PERHAPS UPR 50S.
PREVIOUS DISCUSSION BELOW...
5H RIDGE AXIS SLIDES ACROSS THE GREAT LAKES AND CENTRAL
APPALACHIAN STATES OVERNIGHT AS SUBSIDENCE INVERSION CONTINUE TO
DOMINATE OUR STAGNANT WEATHER PATTERN. WAA TO CONTINUE AT THE
LOWEST LEVELS AND THIS WILL HELP TO LIFT CLOUD LAYER SOME AND IT
SHOULD ALSO LESSEN OUR CHANCES FOR DRIZZLE FORMATION WITH SLIGHT
DRYING AND WARMING OF OF THE LOWER ATMOSPHERIC COLUMN. OUR
FREEZING FOG-FREEZING RAIN POTENTIAL WILL BE GREATLY DIMINISHED.
HAVE INVERSION LIFTING SOME ON MONDAY...ENOUGH TO BREAKUP TO 100
PERCENT VALUES WE HAVE BEEN RUNNING IN OUR SKY GRIDS THE PAST FEW
DAYS...MAINLY OVER THE SOUTHERN COALFIELDS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
MODELS IN BETTER AGREEMENT TODAY WITH THE PRECIPITATION BAND
ASSOCIATED WITH A COLD FRONT. THEREFORE WILL RAISE POPS MONDAY NIGHT
INTO TUESDAY SOME. BEHIND THE FRONT TUESDAY AFTERNOON...THE BOUNDARY
LAYER BECOMES CONVECTIVELY UNSTABLE...SO WILL ALLOW FOR AN INCREASE
IN SHOWERS DURING THE AFTERNOON.
PLENTY OF MOISTURE LINGERS BEHIND THE SYSTEM...BUT TEMPERATURES DO
NOT APPEAR TO BE COLD ENOUGH TO SUPPORT ICE CRYSTAL GROWTH UNTIL
POSSIBLY LATE WEDNESDAY. THEREFORE WENT WITH MORE OF A
DRIZZLE/FREEZING DRIZZLE SCENARIO LATE TUESDAY NIGHT INTO
WEDNESDAY...BEFORE ALLOWING RAIN OR SNOW LATE WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE PERIOD STARTS WITH HORIZONTAL FLOW ALOFT. H850 FREEZING LINE
LIES SOUTH OF THE AREA WHILE THE MINUS 5C DEGREES ACROSS OUR
NORTHERN BORDER THROUGH 12Z WEDNESDAY NIGHT. THIS TRANSLATES IN TO
MAINLY DRY WEATHER WILL COOL NIGHTS AND SEASONAL AFTERNOONS THROUGH
THURSDAY NIGHT.
THE LOW PRESSURE SYSTEM LIFTS NORTHEAST ACROSS TN AND KY INTO
WV...TO BRING PERIODS OF RAIN DURING THE AFTERNOONS FRIDAY AND
SATURDAY...TRANSITIONING INTO WINTRY MIX OR SNOW FRIDAY NIGHT..AS
THEY SPREAD FROM SOUTH TO NORTH.
BOTH THE GFS AND ECMWF SHOW THE SAME TIMING IN THEIR QPF FIELDS.
ALTHOUGH THE GFS TAKES THE LOW PRESSURE OVER THE OH VALLEY MOVING
NORTHEAST INTO NORTHERN WV...WHILE THE ECMWF TRAJECTORY IS FURTHER
SOUTH AND EAST INTO SATURDAY NIGHT. HOWEVER...THE ECMWF BRINGS
STRONGER FORCING WITH A NEGATIVELY TILTED TROF AT H500 THAN THE
GFS AND CMC FOR SATURDAY. KEPT LIKELY POPS ACROSS THE SOUTH AND
CENTRAL WV...AND EASTERN MOUNTAINS THROUGH SATURDAY EVENING.
WENT WITH A BLEND OF THE ECMWF AD HPC GUIDANCE FOR SEASONAL
TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
SUBSIDENCE INVERSION FINALLY SHOWING SIGNS OF BREAKING UP LATER IN
THE TAF PERIOD. UNTIL THEN...WE ARE ENCASED IN A QUASI STEADY-STATE
REGIME OF LIGHT WINDS AND LOW CLOUDS...WITH CIG VALUES GENERALLY
CONTROLLED BY THE MIXING HEIGHT AND ITS DIURNAL CHANGES.
SAT IMAGERY SHOW STRATOCU DECK COVER MOST OF WV AND STRETCHING BACK
ACROSS OH AND KY AND TN. SEEING CIGS IN THE 2-2.5K FOOT RANGE FOR
TONIGHT FOR RIVER SITES...WITH ELEVATED MOUNTAIN VALLEY SITES
IN LOWER CIGS. CKB PROBABLY WILL HOLD THE LOW END IFR CIGS ALL
NIGHT...ALONG WITH A LOWERING OF VSBY INTO THE 1 TO 2 SM RANGE.
HAVE SOME IFR FG KEKN AND ESPECIALLY KBKW LATE TONIGHT.
THE LOW LEVEL FLOW WILL SWING AROUND TO THE E AND THEN SE DURING
THE MORNING HRS. THIS WILL FINALLY ERADICATE THE LOW
STRATUS...FIRST ACROSS SW VA AND SE WV AROUND DAWN. THIS MAY MAKE
IT INTO KBKW BY 12Z. SHOULD THIS END UP BEING FAST THAN CURRENTLY
FCST...THEN KHTS/KCRW MAY SCT OUT AROUND DAWN WHICH WOULD RESULT
IN SOME DENSE RIVER FG.
THE SCT OF STRATUS WILL CONTINUE THE N TREND AS THE DAY
PROGRESSES WITH KHTS/KCRW/KEKN SCT OUT AROUND 15Z. THINK SE OH AND
N WV INCLUDING KPKB WILL HOLD UNTIL PERHAPS 20Z.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TONIGHT MAY SEE LESS IFR OR WORSE FG FOR
KEKN/KBKW.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EST 1HRLY 19 20 21 22 23 00 01 02 03 04 05 06
CRW CONSISTENCY H H H H H H H H H H M H
HTS CONSISTENCY H H H H H H M M M M M H
BKW CONSISTENCY H H H M M M M M M M M M
EKN CONSISTENCY L L L L L L L L M M M M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H L L L L L
AFTER 00Z TUESDAY...
IFR POSSIBLE IN CLOUDS IN THE MOUNTAINS TUESDAY NIGHT INTO
WEDNESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KMC/ARJ/RPY
NEAR TERM...KMC/30
SHORT TERM...RPY
LONG TERM...ARJ
AVIATION...KMC/30
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
930 PM CST SUN DEC 14 2014
.UPDATE...
ISSUED AT 916 PM CST SUN DEC 14 2014
ONLY MINOR CHANGES TO THE ONGOING FORECAST FOR MONDAY. INITIAL
ROUND OF RAIN BEGINNING TO LIFT TOWARD THE SOUTHERN CWA A BIT
AHEAD OF SCHEDULE. THIS PRECIP IS ENTIRELY IN THE FORM OF RAIN.
FURTHER WEST...MODELS A BIT TOO FAR EAST WITH THE WARM NOSE WITH A
MIXED BAG OF PRECIPITATION WEST OF THE MISSOURI RIVER.
PRECIPITATION SHOULD REALLY BEGIN TO BLOSSOM PRIOR TO DAYBREAK AS
STRONG DYNAMIC FORCING BEGINS TO MOVE INTO THE AREA. 00Z NAM AND
LATEST RAP CONTINUE TO SNOW TEMPERATURES HOLDING NEAR OR SLIGHTLY
ABOVE FREEZING THROUGH MID-DAY FROM SIOUX FALLS AND POINTS
SOUTHEAST WHICH COULD MITIGATE THE FREEZING RAIN RISK. POINTS
FURTHER NORTH STILL STAND THE HIGHEST RISK FOR A FEW HOURS OF
ACCUMULATING ICE...WITH TEMPERATURES BETWEEN 30-32 DEGREES.
SOUNDINGS ALSO TRENDING TOWARDS A FAIRLY NARROW AND RAPID
TRANSITION ZONE FROM RAIN TO SLEET TO MODERATE SNOW AROUND MID-DAY
IN THE I-29 CORRIDOR. WITH THE NAM/RAP SUGGESTING A SLIGHT
SOUTHWARD WOBBLE TO THE SYSTEM...HAVE LOWERED SNOW AMOUNTS IN
HURON SLIGHTLY AND RAISED AMOUNTS IN SE SD...SW MN...AND FAR NW IA
SLIGHTLY. THE NARROW AXIS OF A WEAK TROWAL WILL DRAG ACROSS THE
CWA INTO THE EVENING HOURS EXTENDING LIGHT SNOW TOWARD MIDNIGHT...BUT
THE IMPACTS OF WET AND WARMED GROUND ON ACCUMULATED SNOW AMOUNTS
OVER THE SOUTHEASTERN CWA REMAIN IN QUESTION.
GIVEN A SLIGHT BUMP IN SNOW FURTHER SOUTH...WILL ADD LINCOLN AND
LYON COUNTIES TO THE ADVISORY WHERE SNOW TOTALS MAY PUSH THE 3
INCH MARK.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 248 PM CST SUN DEC 14 2014
LARGE...MOIST ALMOST SPRING LIKE SYSTEM REALLY GETTING WRAPPED UP
THIS AFTERNOON IN NORTH TEXAS. AT THE SURFACE THE COLD FRONT HAS
WORKED ACROSS MOST OF SOUTH DAKOTA AND WAS APPROACHING SIOUX FALLS
AT 2030Z. STARTING TO BECOME CONCERNED THAT THIS SURGE EAST OF THE
LOW LEVEL COLD AIR AND THE VERY WOUND UP NATURE OF THE UPPER LOW
WILL BRING A BIGGER THREAT FOR FREEZING PRECIPITATION THAN
PREVIOUSLY THOUGHT. LATEST TREND IN THE 18Z NAM HINTS THAT THIS
MAY BE THE CASE AS THE WARM LAYER ALOFT STILL IN PLACE THROUGH 18Z
OVER MUCH OF SOUTHWEST MINNESOTA AND FAR EASTERN SD. THIS
CONTINUES TO LOOK LIKE THE FOCAL POINT WHERE THE WARM MOIST AIR
ALOFT WRAPS BACK FROM THE NORTHEAST OVER THE TOP OF THE COLDER AIR
AT THE SURFACE. WILL OPT FOR A WARNING OVER A HANDFUL OF COUNTIES
IN THIS AREA AS ICING POTENTIAL LOOKS TO BE ABOUT 2 TENTHS OF AN
INCH...AND POSSIBLY A LITTLE MORE...COUPLED WITH THE LIKELIHOOD OF
2 TO 3 INCHES OF SNOW IN THE AFTERNOON AND EVENING AND NORTH WINDS
LIKELY GUSTING TO ABOUT 35 TO 40 MPH. STILL SOME HOPE THAT SURFACE
TEMPERATURES DOWN THE INTERSTATE 29 CORRIDOR COULD STAY JUST A
TOUCH ABOVE FREEZING BUT THAT HOPE IS BEGINNING TO DWINDLE A BIT
AS THIS COLDER AIR SURGES EAST TODAY AND THE WARM LAYER ALOFT
STAYS IN PLACE A BIT LONGER.
ANOTHER AREA OF CONCERN WILL BE OVER PARTS OF SOUTH CENTRAL SOUTH
DAKOTA WHERE THE INITIAL SURGE OF THE COLD FRONT ALOFT/PV ANOMALY SWINGS
NORTH TONIGHT AND REALLY LOOKS TO INTERACT NICELY WITH THE LOW
LEVEL THERMAL GRADIENT THAT IS DEVELOPING RIGHT NOW. MODELS IN
VERY GOOD AGREEMENT WITH OVERALL PRECIPITATION AMOUNTS WITH ONLY
THE ECMWF A LITTLE FARTHER SOUTH ON THE LOCATION OF THE HEAVIEST
PRECIPITATION. SINCE THE ECMWF DYNAMICS ARE IN FAIRLY CLOSE
ALIGNMENT WITH THE OTHER MODELS WILL KEEP AXIS OF HIGHEST
PRECIPITATION PRETTY CLOSE TO PREVIOUS FORECAST.
ON A SIDE NOTE NOT OUT OF THE QUESTION TO HEAR A RUMBLE OF THUNDER
NEAR SIOUX CITY INTO PARTS OF NORTHWEST IOWA AS SOUNDINGS HINTING AT
JUST A TOUCH OF ELEVATED INSTABILITY EARLY THIS EVENING.
AS THE WAVE SHIFTS EAST ON MONDAY THE TROWAL COLLAPSES AND THE
MAJOR THREAT FOR ICING WILL END. EXPECTING MAINLY A BRIEF ONE TO
TWO HOUR TRANSITION WINDOW FROM RAIN TO MINOR ICING TO SNOW OVER
THE REMAINDER OF SOUTHEAST SD INTO NORTHWEST IOWA. THE SNOW WILL
THEN BUILD INTO THE AREA WITH THE HEAVIEST AMOUNTS FROM ABOUT LAKE
ANDES TO BROOKINGS. OTHER THAN CHARLES MIX AND GREGORY COUNTIES
AREAS TO THE NORTH WILL SEE SOMETHING CLOSER TO 3 TO 5 INCHES.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 248 PM CST SUN DEC 14 2014
RELATIVELY QUIET PERIOD IN THE EXTENDED AS EARLY WEEK SYSTEM LIFTS
TO THE NORTHEAST AND SECOND SYSTEM DIVES INTO THE GREAT LAKES
REGION. THIS SYSTEM REMAINS CUT OFF FROM THE JET STREAM WHICH IS
CONCENTRATED ACROSS THE SOUTHERN US...SO SYSTEM IS RELATIVELY SLOW
TO MOVE. AS THE PATTERN GRADUALLY EVOLVES...EXPECT UPPER LEVEL
RIDGE TO BUILD ACROSS THE NORTH PLAINS LATE IN THE WEEK. MODELS
HAVE COME INTO BETTER AGREEMENT ON LATE WEEK SYSTEM AS ENERGY
REMAINS CONCENTRATED SOUTH OF THE FORECAST AREA UNDER THE JET. AS
SUCH...HAVE A DRY FORECAST THROUGH THE PERIOD. IN
GENERAL...TEMPERATURES APPEAR TO BE FAIRLY SEASONAL...WITH THE
COOLEST TEMPERATURES TUESDAY NIGHT AS WEAK SURFACE RIDGE BUILDS
INTO THE AREA FROM THE NORTH. THEREAFTER...A GRADUAL WARMING TREND
IS EXPECTED THROUGH THE WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 532 PM CST SUN DEC 14 2014
LIGHT RAIN WILL CONTINUE TO DEVELOP ACROSS THE AREA THROUGH THE
EVENING...THEN TRANSITION TO A WINTRY MIX WEST OF THE INTERSTATE
29 CORRIDOR AFTER 06Z. THE TRANSITION TO WINTRY MIX...AND
EVENTUALLY TO ALL SNOW...WILL SPREAD EASTWARD THROUGH THE MORNING
AND AFTERNOON ON MONDAY...NOT REACHING PORTIONS OF NORTHWEST IOWA
UNTIL LATE AFTERNOON.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WINTER WEATHER ADVISORY FROM 4 AM TO 6 PM CST MONDAY FOR SDZ039-
053-054-059-060-065-068.
WINTER STORM WARNING FROM 8 AM TO 6 PM CST MONDAY FOR SDZ040-056.
WINTER WEATHER ADVISORY FROM 8 AM TO 6 PM CST MONDAY FOR SDZ055-
061-062-066-067-069.
WINTER WEATHER ADVISORY UNTIL 6 PM CST MONDAY FOR SDZ052-057-058-
064.
WINTER STORM WARNING UNTIL 6 PM CST MONDAY FOR SDZ050-063.
MN...WINTER STORM WARNING FROM 8 AM TO 6 PM CST MONDAY FOR MNZ071-072-
080-097.
WINTER WEATHER ADVISORY FROM 8 AM TO 6 PM CST MONDAY FOR MNZ081-
089-098.
IA...WINTER WEATHER ADVISORY FROM 8 AM TO 6 PM CST MONDAY FOR IAZ001.
NE...NONE.
&&
$$
UPDATE...DUX
SHORT TERM...08
LONG TERM...
AVIATION...JM
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
837 PM PST SUN DEC 14 2014
.UPDATE...
FINAL UPDATE THIS EVENING TO ACCOUNT FOR TRENDS. RAIN AND SNOW
BAND CONTINUED TO EXIT TO THE EAST WITH ISOLATED SHOWERS LINGERING
BEHIND THIS BAND OVER THE BASIN AND RANGE AND AREAS NORTH OF I-80.
FOG HAS BEEN PATCHY SO FAR AS CLOUDS CONTINUE TO KEEP IT FROM
SPREADING, SO WE WILL KEEP PATCHY WORDING IN THE FORECAST. THE
BAND EXTENDED DOWN INTO MINERAL COUNTY FOR A SHORT TIME EARLIER
THIS EVENING WITH A REPORT OF SNOW FROM A MOTORIST DRIVING BETWEEN
HAWTHORNE AND DAYTON. MOTORISTS SHOULD CONTINUE TO WATCH FOR BLACK
ICE POTENTIAL AS WET ROADS AND TEMPERATURES NEAR FREEZING CONTINUE
OVERNIGHT.
THE MAIN SHORTWAVE WAS APPROACHING THE COAST THIS EVENING WITH
CONVECTIVE ELEMENTS BEGINNING TO ENHANCE OFF THE WEST COAST. THE
LATEST GFS BEGINS TO BRING SNOW TO THE TAHOE BASIN BEFORE DAYBREAK
AND SHOWS PRECIPITATION SPREADING ACROSS NORTHEAST CA INTO WESTERN
NV DURING THE EARLY MORNING. SNOW LEVELS MONDAY MORNING WILL BE
SIMILAR TO WHAT WE SAW EARLIER TODAY SO THAT SOME SNOW MAY
ACCUMULATE JUST OFF THE LOWER VALLEY FLOORS DURING THE RUSH HOUR.
ACCUMULATIONS ARE GOING TO BE MOSTLY LIGHT AND GENERALLY AROUND
AN INCH AT THE 5000 FOOT LEVEL AND 2 TO 4 INCHES IN THE TAHOE
BASIN. MOTORISTS SHOULD CHECK WEATHER AND ROAD CONDITIONS BEFORE
HEADING OUT IN THE MORNING. ADDITIONAL TRAVEL TIME IS LIKELY FOR
THE TAHOE BASIN NORTHWARD INTO PLUMAS AND LASSEN COUNTIES AND
POSSIBLE OVER FAR WESTERN NV MONDAY MORNING. HOHMANN
&&
.PREVIOUS DISCUSSION... /ISSUED 603 PM PST SUN DEC 14 2014/
UPDATE...
SNOW BAND HAS EXITED THE SIERRA FRONT AND NOW EXTENDED ACROSS FAR
NORTHEAST CA INTO NORTHWEST NV AND BASIN AND RANGE. SNOWFALL
AMOUNTS HAVE BEEN LIGHT, GENERALLY 1/2-1 INCH, MAINLY ABOVE THE
5000 FOOT ELEVATION LEVEL. LOCALLY HIGHER AMOUNTS OVER FREDONYER
AND YUBA PASS WITH PLUMAS-EUREKA STATE PARK OBSERVING 0.20 INCH
QPF. BAND WILL CONTINUE TO MOVE SLOWLY EAST AND EXIT LATE THIS
EVENING WITH ISOLATED SHOWERS LINGERING OVERNIGHT ALONG THE CREST
AND FAR NORTHEAST CA/NORTHWEST NV. THE HRRR AND OTHER MODEL DATA
WERE INDICATING SOME BREAKS IN THE CLOUDS RIGHT BEHIND THIS BAND
ALTHOUGH CLOUDS WERE APPROACHING UPSTREAM AND THE BREAK WILL BE
SHORTLIVED. THIS CLEARING WAS ALLOWING TEMPS TO FALL TO NEAR OR
BELOW FREEZING WITH PATCHY FREEZING FOG WHERE PRECIPITATION
OCCURRED THIS EVENING. WE HAVE UPDATED THE FORECAST TO SHOW PATCHY
FREEZING FOG. MOTORISTS SHOULD EXERCISE EXTREME CAUTION TONIGHT AS
SLICK ROADWAYS ARE A GOOD POSSIBILITY WHERE ROADS FREEZE AND ARE
NOT TREATED. FOR ELEVATIONS BELOW 5000 FEET, ICY ROADWAYS WILL BE
MORE LOCALIZED AS TEMPS HOVER JUST ABOVE FREEZING FOR MUCH OF THE
NIGHT. HOHMANN
PREVIOUS DISCUSSION... /ISSUED 423 PM PST SUN DEC 14 2014/
UPDATE...
WARM ADVECTION AHEAD OF OUR MONDAY SYSTEM IS QUITE A BIT STRONGER
THAN MODELS HAD FORECAST WITH LOW-MID LEVEL DRY AIRMASS BEING
OVERCOME IN A SOLID BAND OF SHOWERS OVER NORTHEAST CA AND
NORTHWEST NV. DEWPOINTS WERE IN THE MID 30S AT LOWEST ELEVATIONS
SUCH THAT ACCUMULATION BELOW 5000 FEET IS UNLIKELY BUT ROAD TEMPS
AND DEWPOINTS SUGGEST SOME SNOW MAY BEGIN TO STICK ABOVE 5000 FEET
ESPECIALLY NORTH OF I-80 WHERE DURATION OF SNOWFALL WILL BE
LONGEST. AN INCH OR TWO OF SNOW IS POSSIBLE FROM PLUMAS AND LASSEN
COUNTIES EASTWARD INTO NORTHWEST NV ABOVE 5000 FEET WITH SLICK
ROADS ON AREA PASSES. FOR THE RENO-CARSON CITY AREA, THE BACK EDGE
OF SHOWERS WILL BRING AN ABRUPT END TO THE SHOWERS IN THE NEXT
HOUR OR TWO. SO WE HAVE MAINTAINED AN ISOLATED COVERAGE FOR THIS
EVENING EVEN THOUGH AS OF THIS WRITING, IT WAS SNOWING IN RENO AND
THE NORTH VALLEYS. WE HAVE UPDATED TO BUMP POPS UP FOR AREAS
NORTH AND EAST OF RENO THIS EVENING AS THE BAND WILL LAST FOR
SEVERAL HOURS INTO THE EVENING. HOHMANN
PREVIOUS DISCUSSION... /ISSUED 250 PM PST SUN DEC 14 2014/
SYNOPSIS...
A SERIES OF WEATHER SYSTEMS WILL BRING PERIODS OF SNOW AND RAIN TO
THE SIERRA AND WESTERN NEVADA THIS WEEK. SNOW LEVELS WILL REMAIN
LOW WITH THE POTENTIAL FOR SNOW ACCUMULATIONS ALL THE WAY DOWN TO
THE NEVADA VALLEY FLOORS.
SHORT TERM...
LOW PRESSURE IS APPROACHING THE CALIFORNIA COAST WITH WARM AIR
ADVECTION SHOWERS MOVING ACROSS THE NORTHERN SIERRA. SOME DRY AIR
BELOW RIDGE LEVEL WILL LIMIT PRECIPITATION ACROSS WESTERN NEVADA,
WITH WET ROADS AND AN INCH OR TWO OF SNOW POSSIBLE IN THE SIERRA
INTO THIS EVENING.
MORE SUBSTANTIAL PRECIPITATION WILL REACH THE NORTHERN SIERRA BY
MONDAY AFTERNOON AS THE LOW MOVES INLAND. MODELS ARE SHOWING NEAR
A 0.50 INCH OF LIQUID ALONG THE CREST NORTH OF HIGHWAY 88 MONDAY
AFTERNOON TO MONDAY NIGHT. THIS SHOULD RESULT IN 3-8 INCHES OF
SNOW ALONG THE CREST FROM CARSON PASS TO WESTERN LASSEN COUNTY,
WITH 2-4 INCHES POSSIBLE ALONG THE CREST FOR MONO COUNTY. IN THE
NORTHERN SIERRA EAST OF THE CREST, UP TO 4 INCHES OF ACCUMULATION
IS POSSIBLE. THOSE PLANNING TRAVEL WILL WANT TO BE PREPARED FOR
SLICK ROADS OVER THE SIERRA PASSES MONDAY NIGHT AND EARLY TUESDAY
MORNING.
FOR WESTERN NEVADA, LIGHT RAIN AND SNOW WITH SNOW LEVELS RISING
TO 5000-5500 FEET MONDAY AFTERNOON. IF ADDITIONAL PRECIPITATION
CROSSES THE SIERRA MONDAY NIGHT, SNOW LEVELS WILL DROP DOWN TO
4000-4500 FEET AND LIGHT ACCUMULATIONS COULD OCCUR. HOWEVER MOST
OF THE LIFT AND INSTABILITY APPEARS IT WILL REMAIN OVER NORTHERN
CALIFORNIA, SO CONFIDENCE IS LOW IN SNOW ACCUMULATIONS OVER
WESTERN NEVADA WITH THE FIRST SYSTEM.
A MOIST ONSHORE FLOW WILL CONTINUE FOR TUESDAY WITH SHOWERS
POSSIBLE ALONG THE CREST, BUT LITTLE IF ANY ADDITIONAL
ACCUMULATION. BY WEDNESDAY AS STRONGER AND COLDER SYSTEM MAY
ARRIVE BRINGING THE POTENTIAL FOR UP TO AN INCH OF LIQUID ALONG
THE CREST. THIS SYSTEM HAS QUITE A BIT MORE JET SUPPORT AND COLD
AIR INSTABILITY. HOWEVER MODELS HAVE BEEN INCONSISTENT IN ITS
TRACK SO CONFIDENCE HERE IS LOW TO MEDIUM. BRONG
LONG TERM...THURSDAY THROUGH SUNDAY...
SHORTWAVE RIDGING BECOMES ESTABLISHED ACROSS NORTHERN CALIFORNIA ON
THURSDAY AHEAD OF A LOW PRESSURE SYSTEM THAT LOOKS TO PROVIDE OUR
NEXT CHANCE FOR PRECIPITATION FRIDAY INTO SATURDAY. ONLY MINOR
CHANGES TO THE FORECAST WITH SOME RUN CONSISTENCY ISSUES ARISING
MAINLY IN THE GFS WITH BETTER CONSISTENCY IN THE EC. RECENT RUNS
HAVE DEPICTED ANYTHING FROM A CLOSED LOW ACROSS CENTRAL CALIFORNIA
ON FRIDAY NIGHT TO A MORE INLAND SLIDER TYPE TRAJECTORY IN RECENT
RUNS. HAVE SPREAD HIGHER CHANCES FOR PRECIPITATION FARTHER EASTWARD
ACROSS THE WESTERN NEVADA BASIN AND RANGE WITH A TREND TOWARDS AN
EASTERN MORE TRAJECTORY IN THE GFS.
THOUGH DIFFERENCES IN SYSTEM CHARACTERISTICS EXIST THE TIMING OF THE
EVENT REMAINS GOOD WITH ABOUT A 24 HOUR WINDOW FOR SNOWFALL ACROSS
THE SIERRA AND WESTERN NEVADA FRIDAY AFTERNOON INTO SATURDAY
MORNING. SNOW LEVELS COULD LOWER ENOUGH TO SEE SNOW ACROSS WESTERN
NEVADA FOOTHILLS AND POSSIBLY VALLEY FLOORS BUT THIS WILL BE
ADJUSTED BASED ON THE TRAJECTORY OF THE LOW. THIS FAST MOVING SYSTEM
DOES NOT LOOK TO BE A HEAVY SNOW PRODUCER IN THE SIERRA BUT STILL
MAY PUT DOWN SEVERAL INCHES OF SNOWFALL WHICH COULD RESULT IN TRAVEL
IMPACTS AND SLOW DOWNS. BY SATURDAY AND SUNDAY MOST MEDIUM RANGE
MODELS DEVELOP A CLOSED LOW ACROSS AZ/NM WITH A DRIER PATTERN
BECOMING ESTABLISHED AS A RIDGE FORMS ACROSS THE WEST COAST. FUENTES
AVIATION...
A LOW PRESSURE SYSTEM WILL APPROACH THE WEST COAST THIS EVENING WITH
CHANCES FOR SIERRA SNOWFALL AND A MIX OF RAIN AND SNOW FOR WESTERN
NEVADA TERMINALS. -SHSN POSSIBLE AFTER ABOUT 15Z MONDAY FOR KTRK AND
KTVL WITH PERIODS OF IFR CONDITIONS AND MOUNTAIN TOP OBSCURATION
EXPECTED. A HEAVIER PERIOD OF PRECIPITATION LOOKS TO MOVE IN AFTER 00Z
TUESDAY WITH 1-3" OF RUNWAY ACCUMULATION POSSIBLE AT KTRK/KTVL/KMMH
THRU TUESDAY MORNING. MAINLY LIGHT RAINFALL EXPECTED FOR KRNO/KCXP
MONDAY AFTERNOON WITH A MIX OF RAIN AND SNOW POSSIBLE TUESDAY NIGHT.
WINDS DO NOT LOOK PARTICULARLY STRONG FOR THIS SYSTEM BUT AREAS OF
TURBULENCE POSSIBLE ALONG THE SIERRA WITH GUSTS OVER 40KTS EXPECTED.
FUENTES
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1033 PM MST SUN DEC 14 2014
.UPDATE...
ISSUED AT 905 PM MST SUN DEC 1
UPDATED FOR CURRENT OBS AND RADAR TRENDS...WITH LIGHT WRAP AROUND
SNOWFALL SLOWLY DIMINISHING AS IT MOVES SOUTH AND EAST ACROSS THE
FAR SE PLAINS THROUGH THE REST OF THE EVENING. STILL COULD SEE AN
INCH OR TWO...MAINLY ON GRASSY AREAS OVERNIGHT...WITH BEST CHANCES
NORTH OF HIGHWAY 50 IN PROWERS AND KIOWA COUNTIES.
&&
.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 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1033 PM MST SUN DEC 14 2014
MAINLY VFR CONDITIONS EXPECTED OVER THE NEXT 24 HOURS AT COS...PUB
AND ALS WITH CLOUDS CONTINUING TO DIMINISH AS UPPER LOW ACROSS
SOUTH CENTRAL KANSAS CONTINUES TO LIFT OUT INTO THE UPPER MIDWEST.
THERE COULD BE SOME PATCHY GROUND FOG DEVELOPING AT ALS THROUGH
THE EARLY MORNING HOURS...THOUGH WILL KEEP OUT OF TAF AS NOT
CONFIDENT IN ITS DEVELOPMENT WITH BRISK NORTHWESTLY FLOW ALOFT
PERSISTING ACROSS THE AREA. GUSTY NORTH TO NORTHWEST WINDS AT COS
AND PUB TO DIMINISH THROUGH THE OVERNIGHT HOURS WITH BREEZY
NORTHERLY WINDS EXPECTED AGAIN LATE TOMORROW MORNING THROUGH THE
EARLY AFTERNOON.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MW
SHORT TERM...28
LONG TERM...PGW
AVIATION...MW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
905 PM MST SUN DEC 14 2014
.UPDATE...
ISSUED AT 905 PM MST SUN DEC 1
UPDATED FOR CURRENT OBS AND RADAR TRENDS...WITH LIGHT WRAP AROUND
SNOWFALL SLOWLY DIMINISHING AS IT MOVES SOUTH AND EAST ACROSS THE
FAR SE PLAINS THROUGH THE REST OF THE EVENING. STILL COULD SEE AN
INCH OR TWO...MAINLY ON GRASSY AREAS OVERNIGHT...WITH BEST CHANCES
NORTH OF HIGHWAY 50 IN PROWERS AND KIOWA COUNTIES.
&&
.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...
NONE.
&&
$$
UPDATE...MW
SHORT TERM...28
LONG TERM...PGW
AVIATION...28
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1158 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 06Z...
* LIFR CIGS LIKELY THROUGH JUST AFTER DAYBREAK...INCLUDING AS LOW
AS 200 FT.
* SOMEWHAT VARIABLE VISIBILITY BUT POTENTIAL FOR 1-2SM VISIBILITY
AT TIMES IN DRIZZLE/FOG THROUGH 14Z OR SO.
* SOUTH WINDS BECOMING SOUTHEASTERLY MONDAY MORNING AROUND
10-12KT AND PERSISTING THROUGH EVENING.
* RETURNING IFR AND POSSIBLE LIFR CONDITIONS MONDAY NIGHT IN
FOG/DRIZZLE.
//DISCUSSION...UPDATED 06Z...
SOUTHERLY FLOW HAS ESTABLISHED ITSELF OVER THE AREA AND FOR THE
TIME BEING THAT MEANS CONTINUED REPLENISHMENT OF MOISTURE...SO LOW
CLOUDS AND FOG WILL CONTINUE INTO MONDAY MORNING. AS OF
06Z...TDWR INDICATES DRIZZLE IS BECOMING MORE PATCHY AND
LIGHT AND THAT IS REFLECTED IN SLIGHTLY HIGHER VISIBILITY AT ORD
AND MDW. MOST OUTLYING SITES REMAIN VERY LOW IN BOTH CIG AND
VISIBILITY AND BELIEVE THE GENERAL WEATHER SETUP FAVORS CIGS AND
TO SOME DEGREE VISIBILITY TO COME BACK DOWN AT ORD AND MDW...BUT
HOW FAR IS UNCERTAIN. ALL IN ALL ANY SHIFTS WILL BE VERY SUBTLE IN
SUCH A REGIME. WILL MONITOR TRENDS CLOSELY AND MAKE AMENDMENTS AS
NEEDED.
CONDITIONS SHOULD IMPROVE DURING THE LATTER MORNING MONDAY AND AT
A QUICKER RATE THAN RECENT MORNINGS. AS LOW PRESSURE MOVES NEAR
KANSAS CITY BY MIDDAY...A LEADING ARC OF SHOWERS...LIKELY
WEAKENING SHOULD MOVE OVER THE AREA. BEHIND THIS ANOTHER SURGE OF
MOISTURE OCCURS THAT COULD SUPPORT ISOLATED/SCATTERED SHOWERS AS
WELL AS DRIZZLE AND LOWERING CLOUDS/CIGS. THE LOW IS EXPECTED TO
PASS OVER NORTHERN IL LATE MONDAY NIGHT INTO VERY EARLY TUESDAY
MORNING. THIS MEANS DIMINISHING WINDS. WHILE SOME SHOWERS /AND
EVEN POSSIBLY A STRAY STORM/ WILL BE AROUND MONDAY NIGHT...THE
GENERAL CONDITIONS SHOULD DROP BACK TO IFR IF NOT LIFR BY DAYBREAK
TUESDAY.
SOUTHERLY WINDS WILL INCH SOUTHEASTWARD AND INCREASE IN SPEED AS
THE LOW PRESSURE APPROACHES. WINDS SHOULD REMAIN FROM THE
SOUTHEAST MONDAY NIGHT BEFORE POSSIBLY BECOMING VARIABLE INTO
EARLY TUESDAY MORNING AS THE LOW PASSES OVERHEAD.
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH IN LIFR CIGS THROUGH MOST OF THE NIGHT. LOW IN SPECIFIC
HEIGHTS BUT GIVEN NEARBY OBSERVATIONS 200FT REMAINS PROBABLE.
* LOW IN SPECIFIC TIMING OF WHEN CIGS LIFT MONDAY MORNING.
* LOW-MEDIUM IN VISIBILITY THROUGH MUCH OF THE TAF WITH SOME
VARIABILITY LIKELY THROUGH DAYBREAK.
* HIGH IN WIND TRENDS THROUGH 00Z TUESDAY. MEDIUM AFTER.
* MEDIUM IN CONDITIONS DETERIORATING AGAIN MONDAY NIGHT.
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...MVFR LIKELY...IFR POSSIBLE. CHANCE OF RAIN...POSSIBLY
MIXING WITH WET SNOW BEFORE ENDING.
WEDNESDAY...MVFR CIGS POSSIBLE...ESPECIALLY EARLY.
THURSDAY THROUGH SATURDAY...PRIMARILY VFR.
MTF/IZZI
&&
.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...DENSE FOG ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032 UNTIL 8 AM MONDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565
UNTIL 9 AM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1154 PM CST Sun Dec 14 2014
.UPDATE...
ISSUED AT 840 PM CST SUN DEC 14 2014
Issued a Dense Fog Advisory earlier this evening across northern
portions of the forecast area where fairly widespread 1/4SM mile
visibilities had developed. The advisory currently runs until 8 AM
Monday, but if recent trends persist, it may be able to be
canceled early.
A vertically stacked low pressure system is centered over the
central Plains this evening, with a band of showers on its eastern
periphery. These showers will eventually arrive in the forecast
area by late tonight or during the day Monday, but they will not
be breaking speed record getting here given the vertically stacked
nature of the system. In any event, the pressure gradient will
gradually increase with the approach of the system, resulting in
increased wind speeds. These increased winds, along with a
slightly drier airmass that precedes the rain area, may help to
diminish the fog across the area as the night progresses. This
gradual diminishing should also preclude the need for an expanded
Dense Fog Advisory, and may allow the early cancellation of the
current one.
Aside from the previous need to add the Fog Advisory, going
forecast is in pretty good shape. Plan to make a few tweaks for
the latest trends, but no significant changes are needed at this
time.
&&
.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 vsbys 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 06Z TAFS through 06Z Monday night)
ISSUED AT 1154 PM CST SUN DEC 14 2014
Still looks like IFR or lower conditions will prevail across the
central Illinois terminals through the 06Z TAF valid time. While
visibilities have trended up a bit at most local TAF sites (except
KPIA & KBMI), CIGS are still quite low. Southeast winds have been
picking up into the 10-15 kt range ahead of an approaching storm
system, and this has been an aid to the higher visibilities.
Showers will break out during the morning hours Monday, and they
should be on and off for the rest of the forecast. Winds will pick
up further Monday morning and become gusty at KSPI, KDEC, KCMI due
to their location further south of the track of the surface low
associated with the storm system. Should begin to see winds shift
more south or southwest Monday evening as the surface low begins
to pass to the north of the area. This passage should also taper
off the threat of showers. While a thunderstorm can`t be ruled out
with this system, especially Monday afternoon, expected coverage
is too low to include in terminals at this time.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY until 8 AM CST Monday FOR ILZ027>031-036>038.
&&
$$
UPDATE...Bak
SHORT TERM...Barnes
LONG TERM...Smith
AVIATION...Bak
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
355 AM EST MON DEC 15 2014
.UPDATE...
THE SYNOPSIS...NEAR TERM...AND SHORT TERM SECTIONS HAVE BEEN UPDATED
BELOW.
&&
.SYNOPSIS...
ISSUED AT 355 AM EST MON DEC 15 2014
A LOW PRESSURE SYSTEM WILL BRING RAIN SHOWERS TO CENTRAL INDIANA
EARLY THIS WEEK. AFTER A DRY PERIOD UNDER HIGH PRESSURE
MIDWEEK...ANOTHER LOW PRESSURE SYSTEM WILL BRING CHANCES FOR RAIN OR
SNOW TO THE AREA THIS WEEKEND.
ABOVE AVERAGE TEMPERATURES ARE EXPECTED THROUGH TUESDAY. AFTER
THAT...SLIGHTLY BELOW NORMAL TEMPERATURES WILL TAKE OVER THROUGH THE
WEEKEND.
&&
.NEAR TERM /TODAY AND TONIGHT/...
ISSUED AT 355 AM EST MON DEC 15 2014
MAIN FOCUS FOR THE SHORT TERM WILL BE ON TIMING OF RAIN SHOWERS TO
THE AREA ALONG WITH TEMPERATURES.
MODELS IN GOOD AGREEMENT THAT A STACKED LOW PRESSURE SYSTEM OVER
SOUTH CENTRAL KANSAS EARLY THIS MORNING WILL LIFT NORTHEAST TO
SOUTHEASTERN IOWA BY 00Z THIS EVENING PROVIDING UPPER LEVEL
DIVERGENCE OVER CENTRAL INDIANA AS WELL AS DEEPENING MOISTURE.
NATIONAL RADAR LOOP WAS SHOWING AN AREA OF SHOWERS ACROSS CENTRAL
MISSOURI AND WESTERN ARKANSAS AHEAD OF THIS SYSTEM AND WITHIN
NOCTURNAL LOW LEVEL JET. THIS JET WILL MIGRATE EASTWARD AND WEAKEN A
BIT TO 35 TO 40 KNOTS WITH THE NOSE ACROSS SOUTH CENTRAL INDIANA
LATE THIS AFTERNOON. NAM12 AND HRRR RAPID REFRESH REFLECTIVITY PROGS
SUGGEST MORE OR LESS SOLID AREA OF SHOWERS SHOULD MOVE INTO OUR
SOUTHWESTERN COUNTIES AFTER 10 AM AND APPROACH INTERSTATE 65 BY 4 PM
BEFORE MOVING INTO OHIO AFTER 00Z THIS EVENING. THIS TIMING ALSO
MATCHES UP PRETTY GOOD WITH SIMILAR 00Z MODEL QPF FIELDS.
TONIGHT...TRIPLE POINT OF ASSOCIATED FRONTAL SYSTEM SHOULD LIFT
NORTHEAST ACROSS OUR NORTHERN COUNTIES RESULTING IN ANOTHER MORE
WIDESPREAD AREA OF SHOWERS LIFTING NORTHEAST ACROSS THE AREA. RAISED
QPF A BIT FROM THE 00Z SUPERBLEND AND 06Z HPC NUMBERS WITH STORM
TOTAL PRECIPITATION OF HALF AN INCH POSSIBLE. INSTABILITY PROGS
BRING SOME INSTABILITY UP CLOSE TO OUR SOUTHERN BORDER THIS
AFTERNOON AND EVENING...BUT NOT ENOUGH TO INCLUDE THUNDER AT THIS
POINT AFTER LOOKING AT LIGHTNING STRIKE TRENDS.
WENT ON THE COOL SIDE OF MOS TODAY WITH THE CLOUDS HANGING AROUND
AND RAIN MOVING IN.
&&
.SHORT TERM.../TUESDAY THROUGH WEDNESDAY NIGHT/
ISSUED AT 355 AM EST MON DEC 15 2014
SHORT TERM FOCUS IS ON POPS AS WELL AS TEMPERATURES AS A COLD FRONT
ROLLS THROUGH THE AREA LATE TUESDAY AND TUESDAY NIGHT. MODELS
CONTINUE TO AGREE THAT THE STACKED LOW WILL LIFT NORTHEAST ACROSS
SOUTHERN LOWER MICHIGAN ON TUESDAY AND A COLD FRONT WILL SLIDE
SOUTHEAST ACROSS THE AREA TUESDAY EVENING. MEANWHILE...SUFFICIENT
MOISTURE WILL LINGER THROUGH TUESDAY NIGHT WITH THE EXCEPTION OF
SOME DRYING FROM THE SOUTHWEST. THUS...WILL KEEP DECENT POPS MAINLY
NORTHEAST ON TUESDAY CLOSER TO THE BETTER FORCING AND DEEPER
MOISTURE. THEN...WILL ONLY HANG ON TO SMALL EVENING POPS NORTHEAST
TUESDAY NIGHT AS THE SYSTEM PULLS AWAY AND BECOMES ABSORBED IN AN
UPPER MIDWEST SYSTEM.
COULD SEE SOME BREAKS IN THE CLOUDS ON WEDNESDAY AND WEDNESDAY
NIGHT. HOWEVER...WILL NOT CLEAR THINGS COMPLETELY OUT AS MODEL
SOUNDINGS SHOW ANOTHER STRONG INVERSION.
WITH CLOUDS EXPECTED TO HANG AROUND ON WEDNESDAY WENT WITH THE
COOLER 00Z NAM MOS...OTHERWISE MOS TEMPERATURES CLOSE ENOUGH FOR A
BLEND.
&&
.LONG TERM /THURSDAY THROUGH NEXT SUNDAY/...
ISSUED AT 237 AM EST MON DEC 15 2014
ENSEMBLES SUGGEST THE MAIN WEATHER FEATURE DURING THIS PERIOD WILL
BE AN EJECTING UPPER DISTURBANCE WHICH IS EXPECTED TO MOVE THROUGH
THE LOCAL AREA TOWARDS THE END OF THE WEEK. THERE ARE STILL
DIFFERENCES IN THE TIMING AND TRACK OF THIS SYSTEM. THE TREND IN THE
ENSEMBLES SEEMS TO BE TOWARDS A COLDER MORE SOUTHERLY TRACK...WITH
THE MAJORITY OF THE MEMBERS NOW LEANING IN THIS DIRECTION. THERE ARE
STILL SEVERAL MEMBERS THAT SUPPORT THE MORE NORTHERLY OPERATIONAL
GFS...BUT THESE ARE IN THE MINORITY.
WILL CONTINUE WITH CHANCE POPS FOR MIXED PRECIPITATION ON FRIDAY
INTO SATURDAY FOR NOW TO COVER THE WARMER SOLUTIONS. ACCUMULATING
SNOW IS POSSIBLE BY THE END OF THE WEEK.
&&
.AVIATION /DISCUSSION FOR THE 150900Z KIND TAF UPDATE/...
ISSUED AT 321 AM EST MON DEC 15 2014
CEILINGS HAVE FALLEN INTO THE LIFR CATEGORY AT KIND. CONTINUED
WARM/MOIST ADVECTION THROUGH A NOCTURNALLY COOLING BOUNDARY LAYER
SHOULD HELP TO KEEP THESE LOW CEILINGS AROUND FOR AWHILE.
CONDITIONS SHOULD IMPROVE TOWARDS MIDDAY TODAY AS ORGANIZED LIFT
FROM APPROACHING WEATHER SYSTEM HELPS MIX OUT THE PERSISTENT LOW
LEVEL INVERSION.
PREVIOUS DISCUSSION FOLLOWS.
IFR OR LIFR FLIGHT CONDITIONS OVERNIGHT MAY BRIEFLY IMPROVE TO MVFR
BY LATE MORNING AND IFR LATE MONDAY AND MONDAY NIGHT.
THERE MAY BE A GRADUAL WORSENING OF FLIGHT CONDITIONS OVERNIGHT AS
THE TEMPERATURE INVERSION FALLS BACK BELOW 3KFT LATE TONIGHT. WITH
LIGHT S/SE WINDS...IFR FOG LIKELY TO DEVELOP OVERNIGHT ALONG WITH
CEILINGS AROUND 500 FEET.
AN APPROACHING LOW PRESSURE SYSTEM MOVING INTO THE MID AND UPPER
MISSISSIPPI VALLEY WILL PRODUCE MODERATE SOUTHEAST WINDS AROUND 10
KNOTS MONDAY COMBINED WITH SLIGHTLY DRIER AIR ADVECTING INTO CENTRAL
INDIANA SHOULD ENABLE IMPROVEMENTS IN BOTH CEILINGS AND VISIBILITIES
TO MVFR CATEGORY BY MIDDAY MONDAY.
MODELS INDICATE AREAS OF RAIN WILL SPREAD INTO CENTRAL INDIANA BY
MID OR LATE AFTERNOON CAUSING CEILINGS AND VISIBILITIES TO DROP BACK
TO IFR AND THESE CONDITIONS WILL LIKELY CONTINUE MONDAY NIGHT.
SOUTHEAST WINDS AROUND 6 KNOTS OR LESS OVERNIGHT WILL INCREASE TO 10
KNOTS BY MIDDAY MONDAY AND CONTINUE MONDAY NIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK
SHORT TERM...MK
LONG TERM...JAS
AVIATION...JH/JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
221 AM MST MON DEC 15 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...(TUESDAY THROUGH SUNDAY)
ISSUED AT 134 AM MST MON DEC 15 2014
MAIN CONCERN FOR THE FORECAST PERIOD WILL CENTER AROUND POTENTIAL
STORM SYSTEM MOVING ACROSS THE AREA ON THURSDAY NIGHT AND FRIDAY.
OPERATIONAL GFS BY FAR THE MOST AGGRESSIVE OF MEDIUM RANGE DATA.
WHILE THERE IS SOME ENSEMBLE SUPPORT FOR THIS...OPERATIONAL
ECMWF...GEM ARE TAKING A MUCH DRIER MORE SOUTHERLY TRACK TO THIS
SYSTEM. WHILE CANNOT TOTALLY IGNORE THE GFS...DO NOT FEEL CURRENT
DATA SUPPORTS MORE THAN LOW PROBABILITY OF OCCURRENCES AT THIS
TIME AND DO NOT FEEL RAISING POSSIBILITY OF MEANINGFUL SNOWFALL IS
WARRANTED JUST YET. OTHERWISE...SEASONAL TEMPERATURES IN THE 30S
AND 40S ARE EXPECTED THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1025 PM MST SUN DEC 14 2014
MVFR CONDITIONS AT KGLD AND KMCK SHOULD LOWER TO IFR OVERNIGHT AS
WRAPAROUND SNOW MOVES THROUGH AS THE UPPER LOW MOVES EAST. FLIGHT
CONDITIONS SHOULD IMPROVE TO MVFR AFTER SUNRISE AND THEN TO VFR IN
THE AFTERNOON AS THE LOW MOVES OUT OF THE AREA. STRONG NORTHWEST
WIND WILL CONTINUE BEHIND THE EXITING LOW GRADUALLY DECREASING
MONDAY EVENING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY UNTIL 8 AM MST /9 AM CST/ THIS MORNING
FOR KSZ001-002-013.
CO...WINTER WEATHER ADVISORY UNTIL 8 AM MST THIS MORNING FOR COZ091.
WINTER STORM WARNING UNTIL 8 AM MST THIS MORNING FOR COZ090.
NE...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR NEZ080-
081.
WINTER STORM WARNING UNTIL 8 AM MST THIS MORNING FOR NEZ079.
&&
$$
SHORT TERM...DR
LONG TERM...JRM
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1255 AM EST MON DEC 15 2014
.UPDATE...
ISSUED AT 939 PM EST SUN DEC 14 2014
MANY OBS REPORTING DENSE FOG THROUGHOUT THE EVENING...THUS THE
ISSUANCE OF A DENSE FOG ADVISORY EARLY THIS EVENING IN
COORDINATION WITH MQT. NARROW BAND OF HEAVIER DRIZZLE/POSSIBLY
LIGHT RAIN STEADILY LIFTS NE THRU NRN LWR MICHIGAN...CURRENTLY
POSITIONED FROM CVX TO GLR TO WEST BRANCH...LIKELY DRIVEN BY A
WEAK WARM FRONTAL BOUNDARY. DESPITE THE BAND OF SLIGHTLY HEAVIER
PRECIP...WILL STICK WITH PERIODS OF DRIZZLE FOR THE BALANCE OF THE
NIGHT. WILL CERTAINLY MAINTAIN THE DENSE FOG ADVISORY AS WELL
GIVEN CURRENT OBS.
&&
.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 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1250 AM EST MON DEC 15 2014
BEGINNING TO SOUND LIKE A BROKEN RECORD AS THE SFC HIGH TO THE
SOUTH FOR THE 3RD DAY HAS HELPED TO KEEP A CAPPING INVERSION IN
PLACE, PRODUCING VLIFR AND LIFR CIGS, AND OCCASIONALLY VSBYS. THE
ADDED MOISTURE FROM THE RETURN FLOW INTO THE UPPER GREAT LAKES
DURING THE DAY HAS ADDED TO THE MOISTURE DEPTH SO THAT FOG AND
DRIZZLE ARE WIDESPREAD. THIS WILL CONTINUE THROUGH THE DAY TODAY,
AND PART WAY INTO THE EVENING, THEN THE SFC LOW MOVES INTO THE
REGION AND BEGINS TO BREAK UP THE IFR VSBYS, AND EVENTUALLY, THE
IFR CIGS AS WELL.
&&
.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...DENSE FOG ADVISORY UNTIL 11 AM EST THIS MORNING FOR MIZ008-
015>036-041-042.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...MLR
SHORT TERM...MSB
SHORT TERM...MSB
LONG TERM...ALM
AVIATION...JSL
MARINE...ADAM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1155 PM EST SUN DEC 14 2014
LATEST UPDATE...
AVIATION
.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 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1155 PM EST SUN DEC 14 2014
WIDESPREAD IFR CONDITIONS WILL CONTINUE THROUGH MONDAY MORNING
WITH SOME LIFR EXPECTED AT TIMES OVERNIGHT. WINDS WILL BE FROM THE
SOUTH AOB 10 KNOTS. CONDITIONS SHOULD IMPROVE TO MVFR BY MONDAY
AFTERNOON.
&&
.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...OSTUNO
HYDROLOGY...JAM
MARINE...WDM
AREA FORECAST DISCUSSION
NWS JACKSON MS
340 AM CST MON DEC 15 2014
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT...FOCUS FOR THIS TIME FRAME
WILL BE FOR TODAY AND TONIGHT. WV IMAGERY SHOWING A WRAPPED UP MID
LEVEL COLD CORE QUICKLY LIFTING NE OUT OF N OK/E KS. SYSTEM MOVEMENT
HAS BEEN AS SUCH TO NOT ALLOW LOW LEVEL MOIST SOUTHERLY FLOW TO
BECOME FIRMLY ESTABLISHED...IN FACT...NARROW WARM/MOIST AXIS IS
PRETTY MUCH ALIGNED WITH ITS ATTENDANT COLD FRONT...CURRENTLY MOVING
THROUGH NW AR/SE OK/NE TX. MAJORITY OF ONGOING CONVECTION APPEARS
ELEVATED...ALTHOUGH SOME OVER SE TX MAY BE MORE ROOTED NEAR THE
SURFACE.
WHILE CONFIDENCE IS HIGH THAT THE AREA WILL BE AFFECTED WITH SHOWERS
AND THUNDERSTORMS TODAY AS THE FRONT MOVES THROUGH...FORECAST
PROBLEM WILL BE JUST HOW STRONG STORMS CAN GET. AMBIENT SHEAR WILL
NOT BE A PROBLEM AS 0-3KM SRH VALUES RANGE FROM 300-400 M2/S2...AND
0-1KM VALUES 250-350 M2/S2 DURING THE AFTERNOON/EARLY EVENING TIME
FRAME. THE PROBLEM COMES IN WITH INSTABILITY AND WHETHER IT CAN ROOT
ITSELF NEAR THE GROUND. THE BEST POSSIBILTY FOR THIS TO OCCUR LOOKS
TO BE OVER SW PORTIONS OF THE AREA WHERE SURFACE DEWPOINTS NEAR 65
WILL NOSE UP IMMEDIATELY AHEAD OF THE FRONTAL BOUNDARY THIS
AFTERNOON. AS THIS OCCURS...MIXED LAYER CAPES WILL RISE TO THE
500-700 J/KG RANGE. HRRR AND NAM ARE INDICATING AN INCREASE IN
CONVECTION OVER OUR SW PORTIONS DURING THE AFTERNOON/EARLY EVENING.
THE HRRR IS ALSO INTERMITTENTLY SHOWING SOME DECENT UPDRAFT
HELICITIES WITH SOME OF ITS FORECAST STORMS. WILL...THEREFORE...OUTLOOK
A LIMITED SEVERE/TORNADO THREAT OVER THESE AREAS THIS AFTERNOON/EARLY
EVENING. THREAT SHOULD DIMINISH RAPIDLY BY MID EVENING WITH THE LOSS
OF HEATING./26/
.LONG TERM...WEDNESDAY THROUGH MONDAY...AT THE MIDDLE OF THE WORK WEEK
THE REGION WILL BE UNDER THE INFLUENCE OF ZONAL MEAN RIDGING WITH SURFACE
HIGH PRESSURE CENTERED OVER THE MIDDLE MISSISSIPPI VALLEY. UPPER TROUGHING
OVER THE SOUTHERN ROCKIES WILL CAUSE THE MEAN FLOW TO BE MORE SOUTHWESTERLY
BY WEDNESDAY NIGHT INTO THURSDAY. A WEAK DISTURBANCE COMING FROM THE
PLAINS WILL BRING SOME ISENTROPIC LIFT FOR SOME LIGHT RAIN. THE BEST
LIFT WILL BE ACROSS THE SOUTH. MEANWHILE OUR ROCKIES SYSTEM WILL BE
PUSHING INTO THE PLAINS ON FRIDAY. THERE IS EVEN A WIDER RANGE OF SOLUTIONS
FOR THIS SYSTEM FOR FRIDAY INTO FRIDAY NIGHT. THE GFS CONTINUES TO BE
THE FARTHEST NORTH WITH THE SURFACE LOW GOING FROM THE SOUTHERN
PLAINS TO THE MIDSOUTH REGION. THE EURO SEEMS TO HAVE GONE A LITTLE
FARTHER NORTH ON THIS RUN. IT TAKES THE SURFACE LOW FROM SOUTH
CENTRAL LOUISIANA THROUGH THE NATCHEZ TRACE CORRIDOR FOR FRIDAY
NIGHT. THE CANADIAN MEANWHILE KEEPS IT SOUTH ALONG THE GULF COAST
AND PUSHES IT INTO NORTHERN FLORIDA BY SATURDAY MORNING. THE GFS
MEAN ENSEMBLE IS SIMILAR TO THE EURO TRACK WITH A WEAKER SURFACE
LOW. SO WITH THIS IN MIND WILL GO WITH THE MIDDLE OF THE ROAD WITH
THE WEAKER GFS ENSEMBLE SOLUTION. THE ENSEMBLE HAS THE SHORTWAVE
TROUGH OVER THE MID MISSISSIPPI VALLEY ON FRIDAY NIGHT. SO WITH THIS
IN MIND WILL PUSH THE ISOLATED CONVECTIVE CHANCES A LITTLE FARTHER
NORTH ACROSS THE REGION AROUND THE SURFACE LOW TRACK FOR FRIDAY
NIGHT. THE RAINS WILL CLEAR OUT ON SATURDAY MORNING. SHORTWAVE FLAT
RIDGING WILL DEVELOP ACROSS THE REGION ON SUNDAY INTO MONDAY.
HAVE ALIGNED TEMPS AND POPS TOWARD THE GFS MEAN ENSEMBLE PATH OF THE
SURFACE LOW. FOR THE REST OF THE PERIOD ON POPS AND TEMPS MADE SOME
SLIGHT ADJUSTMENTS./17/
&&
.AVIATION...WITH TIGHTENING PRESSURE GRADIENT OVER OUR WESTERN TAF
SITES...WINDS HAVE STAYED UP OVERNIGHT TO 5 TO 10 KNOTS WHICH HAS
PLAYED A MAJOR ROLE IN NOT ALLOWING FOG FORMATION. GTR/MEI/HBG...
HOWEVER...HAVE HAD CALM WINDS AND INTERMITTENT IFR CEILING AND
VISIBILITIES FROM STRATUS AND FOG. THIS SCENARIO WILL CONTINUE UNTIL
AROUND 14Z WHEN INCREASING WINDS WILL QUICKLY DISSIPATE THE FOG AND
STRATUS. OTHERWISE...VFR TO MVFR CEILINGS WILL SPREAD IN FROM THE
WEST AFTER 14Z AS A COLD FRONT APPROACHES. SHOWERS AND A FEW
THUNDERSTORMS WILL INCREASE FROM THE WEST AS WELL AND LINGER THROUGH
THE END OF THE PERIOD./26/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 71 43 59 35 / 57 45 3 2
MERIDIAN 70 47 61 34 / 49 49 3 2
VICKSBURG 73 41 59 33 / 61 17 2 2
HATTIESBURG 72 52 65 35 / 35 47 3 2
NATCHEZ 72 44 59 34 / 57 27 2 2
GREENVILLE 70 40 55 33 / 59 14 2 2
GREENWOOD 70 42 55 33 / 60 32 2 2
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
403 AM CST MON DEC 15 2014
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 402 AM CST MON DEC 15 2014
MAIN HEADACHE IS FREEZING DRIZZLE AND HOW LONG IT WILL LAST TODAY.
THE SPLIT FLOW ALOFT CONTINUES WITH THE NORTHERN BRANCH SHORTWAVE
DIGGING DOWN THROUGH SOUTHERN CANADA AND THE SOUTHERN CUT OFF LOW
MOVING THROUGH KANSAS ON ITS WAY TO IOWA. THE SFC LOW HAS MOVED TO
THE EAST OF THE CWA AND MOST SITES HAVE SEEN A SHIFT TO
NORTHWESTERLY WINDS AND GOOD COLD AIR ADVECTION. A FEW SPOTS IN
THE EASTERN TIER ARE HANGING ABOVE FREEZING BUT THE REST HAVE
FALLEN BELOW. LOW LEVEL MOISTURE CONTINUES TO BE ABUNDANT EVEN
BEHIND THE COLD FRONT AND MODEL SOUNDINGS INDICATE A DRY LAYER
ALOFT WHERE TEMPS WOULD BE COLD ENOUGH FOR ICE GROWTH...SO MOST OF
OUR PRECIP WILL BE SUPERCOOLED WATER. THE RAP AND NAM BOTH HAVE
THE LOW LEVEL OMEGA IN THAT SATURATED LAYER CONTINUING TO SHOW
SOME RISING MOTION. WILL EXTEND THE FREEZING RAIN ADVISORY UNTIL
15Z AND EXTEND IT EAST AS TEMPS HAVE BEEN FALLING AND VIS HAVE
BEEN RISING WHERE OUR DENSE FOG HEADLINE WAS OVER THE EASTERN
COUNTIES.
THE SOUTHERN BRANCH SHORTWAVE WILL STAY MAINLY TO OUR SOUTHEAST
TODAY...BUT KEPT SOME LOW POPS TO BLEND IN AS THE SYSTEM PASSES
BY. TONIGHT...THE NORTHERN BRANCH SHORTWAVE WILL DIG DOWN INTO
NORTHEASTERN MN AND SFC HIGH PRESSURE WILL BUILD INTO THE WESTERN
PLAINS. SAT LOOP SHOWS FAIRLY CONSISTENT CLOUDS WELL TO OUR NORTH
AND WEST UNTIL ON THE WEST SIDE OF THE SFC RIDGE CURRENTLY ALONG
THE SASKATCHEWAN/ALBERTA BORDER. TIME HEIGHTS CONTINUE TO SHOW A
LOT OF RH AT LOW LEVELS SO THINK THAT CLOUDS WILL HANG ON LONGER
THAN EXPECTED. BUMPED UP CLOUDS AND RAISED LOWS A FEW DEGREES
ACCORDINGLY FOR TONIGHT.
TUESDAY...THE SFC HIGH PRESSURE WILL MOVE EASTWARD INTO THE
CWA...BUT THE AXIS WILL STILL BE WEST OF MOST OF OUR COUNITES SO
KEPT CLOUDS HIGHER A BIT LONGER ALTHOUGH NOT COMPLETELY SOCKED IN.
EVEN WITH A BIT OF SUN COLD AIR ADVECTION WILL KEEP THE TEMPS IN
THE TEENS FOR TUESDAY AND WITH BREEZY NORTHWEST WINDS IT WILL FEEL
RATHER RAW.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 AM CST MON DEC 15 2014
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...SPLIT FLOW CONTINUES WITH
SFC HIGH PRESSURE CONTINUING OVER THE REGION. TEMPS WILL REMAIN
COLD EVEN AS CLOUDS START TO DECREASE. LOWS WILL BE IN THE SINGLE
DIGITS AND HIGHS IN THE TEENS.
THURSDAY THROUGH SUNDAY...LONG WAVE TROUGH OFF THE WEST COAST OF
CANADA REMAINS THROUGH DAY 5 THEN RETROGRADES/RE-ESTABLISH
FARTHER WEST THROUGH THE END OF THE PERIOD. SPLIT FLOW CONTINUES
ACROSS NORTH AMERICA THROUGH THE PERIOD. FLOW ALOFT REMAINS
RELATIVELY PROGRESSIVE THROUGH THE PERIOD. MUCH ABOVE NORMAL
HEIGHTS REMAIN OVER HUDSON BAY AND SOUTHERN CANADA.
GFS AND ECMWF WERE SIMILAR AT THE BEGINNING OF THE PERIOD. HOWEVER
THE GFS WANT TO DEVELOP A STRONGER TROUGH OVER CENTRAL
CANADA/NORTHERN PLAINS ON FRI AND SAT WHICH IS OUT OF PHASE WITH THE
ECMWF FOR THE REST OF THE PERIOD. WILL PREFER THE ECMWF.
LITTLE OR NO PRECIP THROUGH THE EXTENDED FORECAST. LITTLE CHANGE TO
TEMPS ON THU AND FRI. HIGH TEMPS DECREASED A DEGREE OR TWO FOR SAT
AND SUN MOST PLACES COMPARED TO THE PREVIOUS FORECAST PACKAGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1140 PM CST SUN DEC 14 2014
VSBYS WILL CONTINUE TO RISE AS COLDER AND DRIER AIR MOVES IN FROM
CANADA...WITH NW WINDS INCREASING TO GUSTS IN THE UPPER 20S MPH BY
12Z. THIS WILL EFFECTIVELY SCOUR OUT FOG...HOWEVER IFR CIGS
EXPECTED TO CONTINUE THROUGH THE NIGHT AND MUCH OF MONDAY MORNING.
MODELS DO INDICATE THE LOW 2KM SATURATED LYR WILL SCOUR OUT
TOMORROW AFTN...AND TRENDED CIGS INTO MVFR RANGE IN THE 20Z - 22Z
TIME FRAME.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...FREEZING RAIN ADVISORY UNTIL 9 AM CST THIS MORNING FOR NDZ016-
027-029-030-038-039-049-052-053.
MN...FREEZING RAIN ADVISORY UNTIL 9 AM CST THIS MORNING FOR
MNZ001>009-013>017-022>024-027>032-040.
&&
$$
SHORT TERM...JR
LONG TERM...JR/HOPPES
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1253 AM EST MON DEC 15 2014
.SYNOPSIS...
LOW CLOUDS THROUGH EARLY MONDAY. COLD FRONT BRINGS RAIN SHOWERS
MONDAY NIGHT INTO TUESDAY...WITH A CHANCE OF SHOWERS BEHIND THE
SYSTEM INTO WEDNESDAY. ANOTHER LOW APPROACHES FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1015 PM UPDATE...
FORECAST IN GOOD SHAPE. BEGINNING TO SEE VERY LOW CLOUD BASES AND
FG SHOW UP IN THE MOUNTAINS...ESPECIALLY ON THE W SLOPES.
700 PM UPDATE...
NOT MUCH IN THE WAY OF CHANGES TO THE FORECAST FOR THIS EVENING.
STILL EXPECT SOME PATCHY DZ ON THE W SLOPES OF THE N MOUNTAINS.
ALSO EXPECTING SOME FG ALL THE WAY DOWN THE W SPINE OF THE
MOUNTAINS THRU SW VA OVERNIGHT...WHERE LOW CIGS WILL PERSIST.
THE LOW LEVEL FLOW WILL BEGIN TO SWING AROUND TO THE E AND THEN
SE LATE TONIGHT AND EARLY MORNING. THIS SHOULD FINALLY BEGIN TO
ERADICATE THIS LOW STRATUS...FIRST ACROSS SW VA AND SE WV WHERE
LOW TEMPS MAY DO A LAST MINUTE CRASH TO BLO FRZ. HRRR AND RUC ARE
HINTING AT THIS. THINK FROM I64 CORRIDOR AND PTS N WILL HAVE A
HARD TIME DROPPING MUCH TONIGHT...GENERALLY INTO THE UPR 30S.
SHOULD THE CLEARING WORK IN FASTER DURING THE PREDAWN...THEN CRW
TO HTS WILL EXPERIENCE A QUICK DROP IN TEMPS AND PSBL DENSE FG.
THE CLEARING WILL CONTINUE TO PROGRESS N AND W AS THE DAY
PROGRESSES...SUCH THAT MOST PLACES WILL SEE SUN. MAY TAKE UNTIL
AFTERNOON FOR SE OH/N WV THOUGH. WITH DOWNSLOPE SE
FLOW...INCORPORATED THE TYPICAL SPIKE IN TEMPS JUST E OF I79
CORRIDOR...GOING WELL INTO THE 50S...PERHAPS UPR 50S.
PREVIOUS DISCUSSION BELOW...
5H RIDGE AXIS SLIDES ACROSS THE GREAT LAKES AND CENTRAL
APPALACHIAN STATES OVERNIGHT AS SUBSIDENCE INVERSION CONTINUE TO
DOMINATE OUR STAGNANT WEATHER PATTERN. WAA TO CONTINUE AT THE
LOWEST LEVELS AND THIS WILL HELP TO LIFT CLOUD LAYER SOME AND IT
SHOULD ALSO LESSEN OUR CHANCES FOR DRIZZLE FORMATION WITH SLIGHT
DRYING AND WARMING OF OF THE LOWER ATMOSPHERIC COLUMN. OUR
FREEZING FOG-FREEZING RAIN POTENTIAL WILL BE GREATLY DIMINISHED.
HAVE INVERSION LIFTING SOME ON MONDAY...ENOUGH TO BREAKUP TO 100
PERCENT VALUES WE HAVE BEEN RUNNING IN OUR SKY GRIDS THE PAST FEW
DAYS...MAINLY OVER THE SOUTHERN COALFIELDS.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
MODELS IN BETTER AGREEMENT TODAY WITH THE PRECIPITATION BAND
ASSOCIATED WITH A COLD FRONT. THEREFORE WILL RAISE POPS MONDAY NIGHT
INTO TUESDAY SOME. BEHIND THE FRONT TUESDAY AFTERNOON...THE BOUNDARY
LAYER BECOMES CONVECTIVELY UNSTABLE...SO WILL ALLOW FOR AN INCREASE
IN SHOWERS DURING THE AFTERNOON.
PLENTY OF MOISTURE LINGERS BEHIND THE SYSTEM...BUT TEMPERATURES DO
NOT APPEAR TO BE COLD ENOUGH TO SUPPORT ICE CRYSTAL GROWTH UNTIL
POSSIBLY LATE WEDNESDAY. THEREFORE WENT WITH MORE OF A
DRIZZLE/FREEZING DRIZZLE SCENARIO LATE TUESDAY NIGHT INTO
WEDNESDAY...BEFORE ALLOWING RAIN OR SNOW LATE WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE PERIOD STARTS WITH HORIZONTAL FLOW ALOFT. H850 FREEZING LINE
LIES SOUTH OF THE AREA WHILE THE MINUS 5C DEGREES ACROSS OUR
NORTHERN BORDER THROUGH 12Z WEDNESDAY NIGHT. THIS TRANSLATES IN TO
MAINLY DRY WEATHER WILL COOL NIGHTS AND SEASONAL AFTERNOONS THROUGH
THURSDAY NIGHT.
THE LOW PRESSURE SYSTEM LIFTS NORTHEAST ACROSS TN AND KY INTO
WV...TO BRING PERIODS OF RAIN DURING THE AFTERNOONS FRIDAY AND
SATURDAY...TRANSITIONING INTO WINTRY MIX OR SNOW FRIDAY NIGHT..AS
THEY SPREAD FROM SOUTH TO NORTH.
BOTH THE GFS AND ECMWF SHOW THE SAME TIMING IN THEIR QPF FIELDS.
ALTHOUGH THE GFS TAKES THE LOW PRESSURE OVER THE OH VALLEY MOVING
NORTHEAST INTO NORTHERN WV...WHILE THE ECMWF TRAJECTORY IS FURTHER
SOUTH AND EAST INTO SATURDAY NIGHT. HOWEVER...THE ECMWF BRINGS
STRONGER FORCING WITH A NEGATIVELY TILTED TROF AT H500 THAN THE
GFS AND CMC FOR SATURDAY. KEPT LIKELY POPS ACROSS THE SOUTH AND
CENTRAL WV...AND EASTERN MOUNTAINS THROUGH SATURDAY EVENING.
WENT WITH A BLEND OF THE ECMWF AD HPC GUIDANCE FOR SEASONAL
TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
SUBSIDENCE INVERSION BREAKS UP AFTER 15Z WHEN SKIES BEGIN TO CLEAR
AND CONDITIONS RETURN TO VFR AFTER A LONG STINT BETWEEN MVFR AND
IFR/LIFR THANKS TO FLOW TURNING SOUTHEASTERLY. RELIED ON THE LAMP
GUIDANCE FOR TIMING FOR THE MOST PART.
EKN/CKB/BKW COULD BOUNCE THROUGH THE REMINDER OF THE NIGHT BETWEEN
IFR AND MVFR. AN AMENDMENT OR TWO MAY BE NEEDED AT THESE
LOCATIONS.
CLOUD COVER RETURNS TONIGHT AHEAD OF A COLD FRONT THAT WILL MARK
THE RETURN OF THE MVFR CLOUD DECK AFTER 03Z FOR PKB/HTS. HAVE
-SHRA COMING INTO HTS AT 05Z...BUT BEYOND THE SCOPE OF THIS
FORECAST FOR PKB AND THE TERMINALS FURTHER TO THE EAST.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: MVFR/IFR CONDITIONS MAY BOUNCE IN THE
MOUNTAINS/CKB.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 12/15/14
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY H H H H H H H H M M M M
HTS CONSISTENCY H H H H H H H M M M M M
BKW CONSISTENCY H H H H H H L L M M M M
EKN CONSISTENCY M M L L M M H L L M H H
PKB CONSISTENCY H H H H H H H H H M M H
CKB CONSISTENCY H H H H H M M M M L H H
AFTER 06Z TUESDAY...
IFR POSSIBLE IN CLOUDS IN THE MOUNTAINS TUESDAY NIGHT INTO
WEDNESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KMC/ARJ/RPY
NEAR TERM...KMC/26
SHORT TERM...RPY
LONG TERM...ARJ
AVIATION...26
AREA FORECAST DISCUSSION
NWS PORTLAND OR
845 PM PST SUN DEC 14 2014
.SYNOPSIS...AN UPPER LEVEL RIDGE OF HIGH PRESSURE IS GIVING WAY AS
THE FIRST IN A SERIES OF WEAK/SPLITTING FRONTAL SYSTEMS APPROACHES
FROM THE SOUTHWEST. ADDITIONAL WEAK SYSTEMS WILL PERIODICALLY PUSH
ONSHORE THROUGH MIDWEEK. THESE SYSTEMS WILL BRING OCCASIONAL LIGHT
RAIN AND MOUNTAIN SNOW TO THE REGION. MEANWHILE SURFACE HIGH PRESSURE
EAST OF THE CASCADES WILL CONTINUE TO PRODUCE GUSTY EAST WINDS
THROUGH THE COLUMBIA GORGE AND PORTIONS OF THE PORTLAND METRO THROUGH
MIDWEEK. THE NEXT ORGANIZED FRONT APPEARS LIKELY THU NIGHT AND FRI.
THERE ARE SIGNS THAT SUBTROPICAL MOISTURE MAY BRING INCREASING
PRECIPITATION TO THE PAC NW NEXT WEEKEND OR EARLY NEXT WEEK...BUT
CONFIDENCE IN EXACTLY WHERE THE HEAVIEST PRECIPITATION WILL FALL
REMAINS LOW AT THIS TIME.
&&
.EVENING UPDATE...MAIN CHANGES TO THE FORECAST THIS EVENING CENTER
AROUND PRECIPITATION TYPE IN THE GORGE AND HOOD RIVER VALLEY AS THE
FIRST IN A SERIES OF WEAK AND SPLITTY FRONTAL SYSTEMS PUSH NE ACROSS
OUR DISTRICT. NAM BUFR SOUNDINGS APPEAR TO BE TOO COLD NEAR THE
SURFACE AT HOOD RIVER AND THE DALLES...LIKELY DUE TO PERSISTENT
STRATUS EXTENDING INTO THE GORGE FROM THE MID-COLUMBIA BASIN LIMITING
THE POTENTIAL FOR RADIATIONAL COOLING AT NIGHT. THE 00Z NAM BUFR
SOUNDINGS ARE NO EXCEPTION...WHILE THE LATEST RAP SOUNDINGS
CORRESPOND TO THE CURRENT CONDITIONS MORE ACCURATELY AND KEEP TEMPS A
FEW DEGREES ABOVE FREEZING THROUGH EARLY MON AFTERNOON.
04Z OBSERVATIONS SHOW KDLS AND HOOD RIVER WELL UP INTO THE UPPER 30S
WITH DEWPOINTS IN THE MID 30S. ESPECIALLY WITH LOW STRATUS LOCKED
INTO PLACE...IT APPEARS SNOW LEVELS WILL REMAIN WELL OFF THE GORGE
FLOOR AND PROBABLY 1000-1500 FT IN ELEVATION UP THE HOOD RIVER
VALLEY. THEREFORE WE BUMPED UP FCST LOW TEMPERATURES TONIGHT AND SNOW
LEVELS IN HOOD RIVER COUNTY AND EASTERN PORTIONS OF SKAMANIA COUNTY.
TROUT LAKE AND VICINITY MAY STILL PICK UP AN INCH OR TWO OF SNOW OVER
THE NEXT COUPLE DAYS...POSSIBLY PARKDALE AS WELL. MEANWHILE AREAS
BELOW 1000 FT IN AND NEAR THE CENTRAL COLUMBIA GORGE SHOULD JUST
EXPECT PLENTY OF OVERCAST AND PERIODS OF COLD RAIN PERHAPS MIXED WITH
A WET SNOWFLAKE OR TWO. WILL UPDATE THE SPECIAL WEATHER STATEMENT TO
REFLECT THE LATEST FORECAST THINKING.
OTHERWISE THE AFTERNOON FORECAST PACKAGE LOOKS TO BE IN GOOD SHAPE
AND MADE LITTLE TO NO CHANGES OUTSIDE OF THE AREAS MENTIONED ABOVE.
/WEAGLE
/PREV DISC ISSUED 255 PM PST SUN DEC 14 2014/
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT...
A PRETTY NICE DAY FOR MANY ACROSS SW WASHINGTON AND NW OREGON TODAY
AS SHORTWAVE UPPER LEVEL RIDGING SITS OVER THE REGION. AN OFFSHORE
PRES GRADIENT HAS STEADILY INCREASED TODAY...BRINGING GUSTY WINDS
THROUGH THE COLUMBIA RIVER GORGE AND INTO THE NORTHERN WILLAMETTE
VALLEY. THE DRIER OFFSHORE WINDS HELPED TO CLEAR OUT THE FOG AND LOW
CLOUDS UP NORTH TODAY...BUT LOCATIONS FURTHER SOUTH HAVE BEEN MUCH
SLOWER TO CLEAR. THERE IS STILL AN AREA OF LOW STRATUS OVER THE
SOUTHERN WILLAMETTE VALLEY THAT MAY NOT CLEAR AT ALL TODAY. THE
KTTD-KDLS GRADIENT IS NOW AT -7.5 MB...WHICH IS DRIVING SOME WINDS
GUSTS UP AROUND 40 TO 45 MPH AROUND THE WESTERN END OF THE GORGE. THE
LATEST FCST MODELS ARE INDICATING THAT THE GRADIENT WILL REMAIN
AROUND -7 TO -8 MB TONIGHT AND INTO MON...SO THE GUSTY WINDS ARE
EXPECTED TO CONTINUE FOR A WHILE.
A STRETCHING COLD FRONT IS SITTING JUST OFFSHORE THIS AFTERNOON AND
IS IN THE PROCESS OF SPLITTING AS THE BULK OF THE UPPER LEVEL FORCING
DIVES SOUTH TOWARD CALIFORNIA. REMNANTS OF THE FRONTAL MOISTURE WILL
PUSH ONTO THE CENTRAL OR COAST THIS EVENING...THEN SPREAD INLAND
OVERNIGHT INTO MON. THERE WILL BE LITTLE IN THE WAY OF UPPER LEVEL
FORCING...SO DO NOT EXPECT PRECIPITATION TOTALS TO BE IMPRESSIVE AT
ALL WITH THIS SYSTEM. THE HIGHEST POPS WILL BE ALONG THE CENTRAL OR
COAST AND COAST RANGE OVERNIGHT.
THERE MAY BE A ROUND OF A BIT MORE ORGANIZED PRECIP TOMORROW NIGHT AS
A WEAK SHORTWAVE TROUGH ROTATES ONSHORE FROM THE SW. QPF TOTALS AGAIN
ARE NOT VERY IMPRESSIVE...ALTHOUGH THE LAST COUPLE OF RUNS OF THE NAM
AND GFS ARE SUGGESTING AN AREA OF A LITTLE MORE IMPRESSIVE PRECIP
ALONG THE N OR AND S WA CASCADES...INCLUDING THE UPPER HOOD RIVER
VALLEY AND COLUMBIA RIVER GORGE. THIS COULD END UP BEING SIGNIFICANT.
WITH THE CONTINUING EASTERLY FLOW THROUGH THE GORGE...WE ARE STILL
LOOKING AT THE POTENTIAL FOR SOME LIGHT SNOW IN THE UPPER HOOD RIVER
VALLEY AND CENTRAL COLUMBIA RIVER GORGE THROUGH TUE. THE FCST BUFR
SOUNDINGS HAVE CONTINUED TO SHOW CLEARLY SNOW PROFILES AROUND HOOD
RIVER THROUGH ABOUT MIDDAY TUE. SO IF THE AREA OF ENHANCED QPF SHOWN
IN THE MODELS DOES OCCUR...THE CENTRAL GORGE AND UPPER HOOD RIVER
VALLEY COULD PICK UP AN INCH OR TWO OF SNOW. AS THE PREVIOUS FCST
SHIFT POINTED OUT...WITH LOW STRATUS IN PLACE IN THESE AREAS RIGHT
NOW...THE COMPONENTS MIGHT BE IN PLACE FOR A SEEDER FEEDER MECHANISM
TO DEVELOP WITH SOME ADDITIONAL ENHANCEMENT FROM LIGHT EASTERLY
UPSLOPING IN THE HOOD RIVER VALLEY. WILL ISSUE AN SPS SHORTLY TO
COVER THIS POTENTIAL.
ANOTHER SYSTEM WILL ARRIVE ON TUE...WITH THE BULK OF THE UPPER LEVEL
ENERGY AGAIN DIVING SOUTH TOWARD SOUTHERN OREGON AND CALIFORNIA.
EXPECT ANOTHER ROUND OF LIGHT PRECIP OVER OUR FCST AREA. THE MODELS
ARE INDICATING THAT THE EASTERLY GRADIENT WEAKENS SOMEWHAT ON
TUE...WITH THE HOOD RIVER AREA SOUNDINGS WARMING TO ABOVE FREEZING.
YET ANOTHER WEAK SHORTWAVE IS EXPECTED ON WED...WHICH MAY BRING
ANOTHER ROUND OF LIGHT PRECIP. THE GFS HAS STEADFASTLY REFUSED TO
SHOW ANY PRECIP WITH THIS WAVE...WHILE THE ECMWF IS SHARPER WITH THE
WAVE AND IS BRINGING A PERIOD OF STEADIER PRECIP. WILL CONTINUE TO
KEEP CHC POPS IN THE FCST. PYLE
.LONG TERM...THU LOOKS TO BE MAINLY DRY AS A SHORTWAVE UPPER LEVEL
RIDGE MOVES ACROSS THE PAC NW. HOWEVER...CONFIDENCE IS FAIRLY HIGH
THAT A MORE ORGANIZED FRONTAL SYSTEM WILL MOVE ONSHORE THU NIGHT AND
FRI. EXPECT A ROUND OF MODERATE RAINFALL AND SOME BREEZY WINDS ALONG
THE COAST WITH THIS SYSTEM. THE EXTENDED FCST MODELS ARE INDICATING
THAT THERE IS POTENTIAL FOR AN ATMOSPHERIC RIVER TYPE SET UP TO OCCUR
OVER THE WEEKEND INTO EARLY NEXT WEEK. AT THIS POINT...THE HEAVIEST
PRECIP APPEARS TO BE FOCUSED WELL TO OUR NORTH OVER THE WEEKEND...
THEN STARTS TO MOVE SOUTHWARD TOWARD US EARLY NEXT WEEK. HOWEVER...
CONFIDENCE IN THE FCST DETAILS THIS FAR OUT ARE NOT HIGH. PYLE
&&
.AVIATION...SKIES REMAIN GENERALLY CLEAR WITH VFR CONDITIONS ACROSS
SOUTHWEST WASHINGTON AND NORTHWEST OREGON NORTH OF A LIFTING
FRONTAL BOUNDARY. THIS BOUNDARY IS CURRENTLY LOCATED JUST SOUTH OF
A KTMK-KSLE-KBDN LINE AND WILL CONTINUE MOVING NORTH TONIGHT
BRINGING INCREASING MID CLOUDS AND SOME LIGHT RAIN.
MEANWHILE...BRISK EAST WINDS CONTINUE THROUGH THE GORGE WITH
OFFSHORE FLOW CONTINUING TONIGHT AND MONDAY. DESPITE INCREASING
CLOUDS OVERHEAD...STILL EXPECT SOME LOCAL AREAS OF IFR STRATUS TO
DEVELOP IN THE SOUTH AND PERHAPS CENTRAL VALLEY...THOUGH THE
PRECIPITATION MAY MIX SOME OF THE LOW STRATUS OUT TEMPORARILY.
ELSEWHERE...EXPECT PRIMARILY VFR CONDITIONS WITH DEVELOPING MID
CLOUDS. EAST WINDS CONTINUE THROUGH THE GORGE AND THE EAST SIDE OF
THE PORTLAND METRO. FOR MONDAY...EXPECT VFR CIGS AND OCCASIONAL
LIGHT RAIN SHOWERS AS ADDITIONAL MOISTURE SPREADS NORTHWARD.
KPDX AND APPROACHES...VFR THIS EVENING WITH GUSTY EAST WINDS
CONTINUING THROUGH MONDAY. SOME VFR CIGS MAY DEVELOP LATER
TONIGHT AND THROUGH MONDAY WITH A FEW LIGHT RAIN SHOWERS AT
TIMES. CULLEN
&&
.MARINE...SMALL CRAFT ADVISORY WINDS CONTINUE OVER THE OUTER
WATERS AHEAD OF AN APPROACHING FRONTAL SYSTEM. GUSTY OFFSHORE
WINDS HAVE CONTINUED OVER THE NORTHERN INNER WATERS...INFLUENCED
BY GAPS IN THE COASTAL TERRAIN. HOWEVER...WINDS MAY STAY JUST
BELOW SMALL CRAFT ADVISORY THRESHOLDS IN THE SOUTHERN INNER
WATERS. THE WINDS IN THE NORTHERN INNER WATERS WEAKEN MONDAY
NIGHT AND TUESDAY...BUT THE OUTER WATERS MAY NOT DECREASE MUCH
UNTIL TUESDAY.
FORECAST MODELS CONTINUE TO DISAGREE A BIT WITH RESPECT TO
INTENSITY OF A FEW FRONTAL SYSTEMS FOR THE MIDDLE OF THE
WEEK...BUT GENERALLY EXPECT PERIODS OF GUSTY WINDS REACHING SMALL
CRAFT ADVISORY CRITERIA AT TIMES THROUGH THE WEEK. A STRONGER
FRONT MAY BRING HIGH END SMALL CRAFT WINDS ON THURSDAY INTO
FRIDAY.
SEAS HAVE BEEN BUILDING THIS EVENING IN RESPONSE TO AN ARRIVING
LONG PERIOD WESTERLY SWELL...WITH WAVE HEIGHTS REACHING 13 FT AT
BUOY 46089...AND 8 TO 10 FT OVER THE INNER WATERS. SEAS WILL
LIKELY REMAIN ABOVE 10 FT INTO TUESDAY...WITH A PEAK IN THE MID
TEENS ON MONDAY. SEAS WILL THEN HOVER IN THE 9 TO 11 FT RANGE FOR
MUCH OF THE WEEK UNTIL A LARGER WEST SWELL MAY ARRIVE BY THE END
OF THE WEEK. CULLEN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST TUESDAY 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 TUESDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT
60 NM.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM PST MONDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
OUT 10 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 PM
PST MONDAY.
&&
$$
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 SIOUX FALLS SD
1104 PM CST SUN DEC 14 2014
.UPDATE...
ISSUED AT 916 PM CST SUN DEC 14 2014
ONLY MINOR CHANGES TO THE ONGOING FORECAST FOR MONDAY. INITIAL
ROUND OF RAIN BEGINNING TO LIFT TOWARD THE SOUTHERN CWA A BIT
AHEAD OF SCHEDULE. THIS PRECIP IS ENTIRELY IN THE FORM OF RAIN.
FURTHER WEST...MODELS A BIT TOO FAR EAST WITH THE WARM NOSE WITH A
MIXED BAG OF PRECIPITATION WEST OF THE MISSOURI RIVER.
PRECIPITATION SHOULD REALLY BEGIN TO BLOSSOM PRIOR TO DAYBREAK AS
STRONG DYNAMIC FORCING BEGINS TO MOVE INTO THE AREA. 00Z NAM AND
LATEST RAP CONTINUE TO SNOW TEMPERATURES HOLDING NEAR OR SLIGHTLY
ABOVE FREEZING THROUGH MID-DAY FROM SIOUX FALLS AND POINTS
SOUTHEAST WHICH COULD MITIGATE THE FREEZING RAIN RISK. POINTS
FURTHER NORTH STILL STAND THE HIGHEST RISK FOR A FEW HOURS OF
ACCUMULATING ICE...WITH TEMPERATURES BETWEEN 30-32 DEGREES.
SOUNDINGS ALSO TRENDING TOWARDS A FAIRLY NARROW AND RAPID
TRANSITION ZONE FROM RAIN TO SLEET TO MODERATE SNOW AROUND MID-DAY
IN THE I-29 CORRIDOR. WITH THE NAM/RAP SUGGESTING A SLIGHT
SOUTHWARD WOBBLE TO THE SYSTEM...HAVE LOWERED SNOW AMOUNTS IN
HURON SLIGHTLY AND RAISED AMOUNTS IN SE SD...SW MN...AND FAR NW IA
SLIGHTLY. THE NARROW AXIS OF A WEAK TROWAL WILL DRAG ACROSS THE
CWA INTO THE EVENING HOURS EXTENDING LIGHT SNOW TOWARD MIDNIGHT...BUT
THE IMPACTS OF WET AND WARMED GROUND ON ACCUMULATED SNOW AMOUNTS
OVER THE SOUTHEASTERN CWA REMAIN IN QUESTION.
GIVEN A SLIGHT BUMP IN SNOW FURTHER SOUTH...WILL ADD LINCOLN AND
LYON COUNTIES TO THE ADVISORY WHERE SNOW TOTALS MAY PUSH THE 3
INCH MARK.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 248 PM CST SUN DEC 14 2014
LARGE...MOIST ALMOST SPRING LIKE SYSTEM REALLY GETTING WRAPPED UP
THIS AFTERNOON IN NORTH TEXAS. AT THE SURFACE THE COLD FRONT HAS
WORKED ACROSS MOST OF SOUTH DAKOTA AND WAS APPROACHING SIOUX FALLS
AT 2030Z. STARTING TO BECOME CONCERNED THAT THIS SURGE EAST OF THE
LOW LEVEL COLD AIR AND THE VERY WOUND UP NATURE OF THE UPPER LOW
WILL BRING A BIGGER THREAT FOR FREEZING PRECIPITATION THAN
PREVIOUSLY THOUGHT. LATEST TREND IN THE 18Z NAM HINTS THAT THIS
MAY BE THE CASE AS THE WARM LAYER ALOFT STILL IN PLACE THROUGH 18Z
OVER MUCH OF SOUTHWEST MINNESOTA AND FAR EASTERN SD. THIS
CONTINUES TO LOOK LIKE THE FOCAL POINT WHERE THE WARM MOIST AIR
ALOFT WRAPS BACK FROM THE NORTHEAST OVER THE TOP OF THE COLDER AIR
AT THE SURFACE. WILL OPT FOR A WARNING OVER A HANDFUL OF COUNTIES
IN THIS AREA AS ICING POTENTIAL LOOKS TO BE ABOUT 2 TENTHS OF AN
INCH...AND POSSIBLY A LITTLE MORE...COUPLED WITH THE LIKELIHOOD OF
2 TO 3 INCHES OF SNOW IN THE AFTERNOON AND EVENING AND NORTH WINDS
LIKELY GUSTING TO ABOUT 35 TO 40 MPH. STILL SOME HOPE THAT SURFACE
TEMPERATURES DOWN THE INTERSTATE 29 CORRIDOR COULD STAY JUST A
TOUCH ABOVE FREEZING BUT THAT HOPE IS BEGINNING TO DWINDLE A BIT
AS THIS COLDER AIR SURGES EAST TODAY AND THE WARM LAYER ALOFT
STAYS IN PLACE A BIT LONGER.
ANOTHER AREA OF CONCERN WILL BE OVER PARTS OF SOUTH CENTRAL SOUTH
DAKOTA WHERE THE INITIAL SURGE OF THE COLD FRONT ALOFT/PV ANOMALY SWINGS
NORTH TONIGHT AND REALLY LOOKS TO INTERACT NICELY WITH THE LOW
LEVEL THERMAL GRADIENT THAT IS DEVELOPING RIGHT NOW. MODELS IN
VERY GOOD AGREEMENT WITH OVERALL PRECIPITATION AMOUNTS WITH ONLY
THE ECMWF A LITTLE FARTHER SOUTH ON THE LOCATION OF THE HEAVIEST
PRECIPITATION. SINCE THE ECMWF DYNAMICS ARE IN FAIRLY CLOSE
ALIGNMENT WITH THE OTHER MODELS WILL KEEP AXIS OF HIGHEST
PRECIPITATION PRETTY CLOSE TO PREVIOUS FORECAST.
ON A SIDE NOTE NOT OUT OF THE QUESTION TO HEAR A RUMBLE OF THUNDER
NEAR SIOUX CITY INTO PARTS OF NORTHWEST IOWA AS SOUNDINGS HINTING AT
JUST A TOUCH OF ELEVATED INSTABILITY EARLY THIS EVENING.
AS THE WAVE SHIFTS EAST ON MONDAY THE TROWAL COLLAPSES AND THE
MAJOR THREAT FOR ICING WILL END. EXPECTING MAINLY A BRIEF ONE TO
TWO HOUR TRANSITION WINDOW FROM RAIN TO MINOR ICING TO SNOW OVER
THE REMAINDER OF SOUTHEAST SD INTO NORTHWEST IOWA. THE SNOW WILL
THEN BUILD INTO THE AREA WITH THE HEAVIEST AMOUNTS FROM ABOUT LAKE
ANDES TO BROOKINGS. OTHER THAN CHARLES MIX AND GREGORY COUNTIES
AREAS TO THE NORTH WILL SEE SOMETHING CLOSER TO 3 TO 5 INCHES.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 248 PM CST SUN DEC 14 2014
RELATIVELY QUIET PERIOD IN THE EXTENDED AS EARLY WEEK SYSTEM LIFTS
TO THE NORTHEAST AND SECOND SYSTEM DIVES INTO THE GREAT LAKES
REGION. THIS SYSTEM REMAINS CUT OFF FROM THE JET STREAM WHICH IS
CONCENTRATED ACROSS THE SOUTHERN US...SO SYSTEM IS RELATIVELY SLOW
TO MOVE. AS THE PATTERN GRADUALLY EVOLVES...EXPECT UPPER LEVEL
RIDGE TO BUILD ACROSS THE NORTH PLAINS LATE IN THE WEEK. MODELS
HAVE COME INTO BETTER AGREEMENT ON LATE WEEK SYSTEM AS ENERGY
REMAINS CONCENTRATED SOUTH OF THE FORECAST AREA UNDER THE JET. AS
SUCH...HAVE A DRY FORECAST THROUGH THE PERIOD. IN
GENERAL...TEMPERATURES APPEAR TO BE FAIRLY SEASONAL...WITH THE
COOLEST TEMPERATURES TUESDAY NIGHT AS WEAK SURFACE RIDGE BUILDS
INTO THE AREA FROM THE NORTH. THEREAFTER...A GRADUAL WARMING TREND
IS EXPECTED THROUGH THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1101 PM CST SUN DEC 14 2014
LIGHT RAIN WILL CONTINUE TO DEVELOP ACROSS THE AREA THROUGH THE
NIGHT...TRANSITIONING TO A WINTRY MIX WEST OF THE INTERSTATE 29
CORRIDOR AFTER 08Z. THE TRANSITION TO WINTRY MIX...AND EVENTUALLY
TO ALL SNOW...WILL SPREAD EASTWARD THROUGH THE MORNING AND
AFTERNOON ON MONDAY...NOT REACHING PORTIONS OF NORTHWEST IOWA
UNTIL LATE AFTERNOON. IN ADDITION...NORTHERLY WINDS WILL PICK UP
ON MONDAY...GUSTING TO AROUND 30 KTS AT TIMES.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WINTER WEATHER ADVISORY FROM 4 AM TO 6 PM CST MONDAY FOR SDZ039-
053-054-059-060-065-068.
WINTER STORM WARNING FROM 8 AM TO 6 PM CST MONDAY FOR SDZ040-056.
WINTER WEATHER ADVISORY FROM 8 AM TO 6 PM CST MONDAY FOR SDZ055-
061-062-066-067-069.
WINTER WEATHER ADVISORY UNTIL 6 PM CST MONDAY FOR SDZ052-057-058-
064.
WINTER STORM WARNING UNTIL 6 PM CST MONDAY FOR SDZ050-063.
MN...WINTER STORM WARNING FROM 8 AM TO 6 PM CST MONDAY FOR MNZ071-072-
080-097.
WINTER WEATHER ADVISORY FROM 8 AM TO 6 PM CST MONDAY FOR MNZ081-
089-098.
IA...WINTER WEATHER ADVISORY FROM 8 AM TO 6 PM CST MONDAY FOR IAZ001.
NE...NONE.
&&
$$
UPDATE...DUX
SHORT TERM...08
LONG TERM...
AVIATION...JM
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
959 AM EST MON DEC 15 2014
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 355 AM EST MON DEC 15 2014
A LOW PRESSURE SYSTEM WILL BRING RAIN SHOWERS TO CENTRAL INDIANA
EARLY THIS WEEK. AFTER A DRY PERIOD UNDER HIGH PRESSURE
MIDWEEK...ANOTHER LOW PRESSURE SYSTEM WILL BRING CHANCES FOR RAIN OR
SNOW TO THE AREA THIS WEEKEND.
ABOVE AVERAGE TEMPERATURES ARE EXPECTED THROUGH TUESDAY. AFTER
THAT...SLIGHTLY BELOW NORMAL TEMPERATURES WILL TAKE OVER THROUGH THE
WEEKEND.
&&
.NEAR TERM /TODAY AND TONIGHT/...
ISSUED AT 959 AM EST MON DEC 15 2014
RAIN CONTINUES TO MARCH EAST TOWARD CENTRAL INDIANA FROM ILLINOIS
THIS MORNING. THERE HAS BEEN SOME WEAKENING TO THE RAIN...BUT NOT AS
MUCH AS SOME OF THE MODELS HAVE BEEN SUGGESTING. THUS ONLY HAD TO
MAKE SOME MINOR ADJUSTMENTS TO HOURLY POPS.
BASED ON LATEST TRENDS AND MODEL DATA...BUMPED DOWN TEMPERATURES A
BIT FOR THIS AFTERNOON AND ADJUSTED TEMPERATURES THIS EVENING.
VISIBILITY HAS IMPROVED TO 3 MILES OR ABOVE MOST AREAS...SO REMOVED
FOG AS NEEDED.
PREVIOUS DISCUSSION FOLLOWS...
MAIN FOCUS FOR THE SHORT TERM WILL BE ON TIMING OF RAIN SHOWERS TO
THE AREA ALONG WITH TEMPERATURES.
MODELS IN GOOD AGREEMENT THAT A STACKED LOW PRESSURE SYSTEM OVER
SOUTH CENTRAL KANSAS EARLY THIS MORNING WILL LIFT NORTHEAST TO
SOUTHEASTERN IOWA BY 00Z THIS EVENING PROVIDING UPPER LEVEL
DIVERGENCE OVER CENTRAL INDIANA AS WELL AS DEEPENING MOISTURE.
NATIONAL RADAR LOOP WAS SHOWING AN AREA OF SHOWERS ACROSS CENTRAL
MISSOURI AND WESTERN ARKANSAS AHEAD OF THIS SYSTEM AND WITHIN
NOCTURNAL LOW LEVEL JET. THIS JET WILL MIGRATE EASTWARD AND WEAKEN A
BIT TO 35 TO 40 KNOTS WITH THE NOSE ACROSS SOUTH CENTRAL INDIANA
LATE THIS AFTERNOON. NAM12 AND HRRR RAPID REFRESH REFLECTIVITY PROGS
SUGGEST MORE OR LESS SOLID AREA OF SHOWERS SHOULD MOVE INTO OUR
SOUTHWESTERN COUNTIES AFTER 10 AM AND APPROACH INTERSTATE 65 BY 4 PM
BEFORE MOVING INTO OHIO AFTER 00Z THIS EVENING. THIS TIMING ALSO
MATCHES UP PRETTY GOOD WITH SIMILAR 00Z MODEL QPF FIELDS.
TONIGHT...TRIPLE POINT OF ASSOCIATED FRONTAL SYSTEM SHOULD LIFT
NORTHEAST ACROSS OUR NORTHERN COUNTIES RESULTING IN ANOTHER MORE
WIDESPREAD AREA OF SHOWERS LIFTING NORTHEAST ACROSS THE AREA. RAISED
QPF A BIT FROM THE 00Z SUPERBLEND AND 06Z HPC NUMBERS WITH STORM
TOTAL PRECIPITATION OF HALF AN INCH POSSIBLE. INSTABILITY PROGS
BRING SOME INSTABILITY UP CLOSE TO OUR SOUTHERN BORDER THIS
AFTERNOON AND EVENING...BUT NOT ENOUGH TO INCLUDE THUNDER AT THIS
POINT AFTER LOOKING AT LIGHTNING STRIKE TRENDS.
WENT ON THE COOL SIDE OF MOS TODAY WITH THE CLOUDS HANGING AROUND
AND RAIN MOVING IN.
&&
.SHORT TERM.../TUESDAY THROUGH WEDNESDAY NIGHT/
ISSUED AT 355 AM EST MON DEC 15 2014
SHORT TERM FOCUS IS ON POPS AS WELL AS TEMPERATURES AS A COLD FRONT
ROLLS THROUGH THE AREA LATE TUESDAY AND TUESDAY NIGHT. MODELS
CONTINUE TO AGREE THAT THE STACKED LOW WILL LIFT NORTHEAST ACROSS
SOUTHERN LOWER MICHIGAN ON TUESDAY AND A COLD FRONT WILL SLIDE
SOUTHEAST ACROSS THE AREA TUESDAY EVENING. MEANWHILE...SUFFICIENT
MOISTURE WILL LINGER THROUGH TUESDAY NIGHT WITH THE EXCEPTION OF
SOME DRYING FROM THE SOUTHWEST. THUS...WILL KEEP DECENT POPS MAINLY
NORTHEAST ON TUESDAY CLOSER TO THE BETTER FORCING AND DEEPER
MOISTURE. THEN...WILL ONLY HANG ON TO SMALL EVENING POPS NORTHEAST
TUESDAY NIGHT AS THE SYSTEM PULLS AWAY AND BECOMES ABSORBED IN AN
UPPER MIDWEST SYSTEM.
COULD SEE SOME BREAKS IN THE CLOUDS ON WEDNESDAY AND WEDNESDAY
NIGHT. HOWEVER...WILL NOT CLEAR THINGS COMPLETELY OUT AS MODEL
SOUNDINGS SHOW ANOTHER STRONG INVERSION.
WITH CLOUDS EXPECTED TO HANG AROUND ON WEDNESDAY WENT WITH THE
COOLER 00Z NAM MOS...OTHERWISE MOS TEMPERATURES CLOSE ENOUGH FOR A
BLEND.
&&
.LONG TERM /THURSDAY THROUGH NEXT SUNDAY/...
ISSUED AT 237 AM EST MON DEC 15 2014
ENSEMBLES SUGGEST THE MAIN WEATHER FEATURE DURING THIS PERIOD WILL
BE AN EJECTING UPPER DISTURBANCE WHICH IS EXPECTED TO MOVE THROUGH
THE LOCAL AREA TOWARDS THE END OF THE WEEK. THERE ARE STILL
DIFFERENCES IN THE TIMING AND TRACK OF THIS SYSTEM. THE TREND IN THE
ENSEMBLES SEEMS TO BE TOWARDS A COLDER MORE SOUTHERLY TRACK...WITH
THE MAJORITY OF THE MEMBERS NOW LEANING IN THIS DIRECTION. THERE ARE
STILL SEVERAL MEMBERS THAT SUPPORT THE MORE NORTHERLY OPERATIONAL
GFS...BUT THESE ARE IN THE MINORITY.
WILL CONTINUE WITH CHANCE POPS FOR MIXED PRECIPITATION ON FRIDAY
INTO SATURDAY FOR NOW TO COVER THE WARMER SOLUTIONS. ACCUMULATING
SNOW IS POSSIBLE BY THE END OF THE WEEK.
&&
.AVIATION /DISCUSSION FOR THE 151500Z TAF UPDATE/...
ISSUED AT 926 AM EST MON DEC 15 2014
IFR CEILINGS CONTINUE TO PLAGUE THE TERMINALS AS OF 14Z. SHOULD SEE
SOME SUBTLE IMPROVEMENTS OVER THE NEXT FEW HOURS...BUT EXPECT MVFR
STRATUS TO LINGER AT LEAST IN A SCATTERED NATURE INTO THE AFTERNOON.
TWEAKED THE TIMING ON ARRIVAL OF RAIN BASED ON CURRENT HI-RES DATA
AND ONGOING TRENDS. EXPECT SCATTERED SHOWERS AFTER 17Z IN THE WEST
WITH MORE WIDESPREAD LIGHT RAIN ARRIVING BY 20-22Z.
12Z DISCUSSION FOLLOWS.
LOW CEILINGS 004-007 AGL CURRENTLY OVER THE TAF SITES EXPECTED TO
IMPROVE FROM SOUTH TO NORTH TOWARDS THE MIDDAY HOURS AS ORGANIZED
LIFT FROM APPROACHING LOW PRESSURE SYSTEM HELPS TO BREAK UP THE
PERSISTENT LOW LEVEL INVERSION. SATELLITE LOOPS INDICATES THE BACK
EDGE OF THESE LOW CEILINGS PUSHING NORTH THROUGH FAR SOUTHERN
ILLINOIS/WESTERN KENTUCKY. CONDITIONS WILL PROBABLY IMPROVE TO VFR
BY EARLY AFTERNOON AT ALL THE TAF SITES...EXCEPT FOR MAYBE KLAF
WHERE LOWER CLOUD COVER MAY LINGER LONGER INTO THE DAY.
SHORT TERM MODEL GUIDANCE SUGGESTS RAIN WILL OVERSPREAD THE TAF
SITES FROM SOUTHWEST TO NORTHEAST AROUND 152000Z-152200Z. AT THIS
POINT...APPEARS RAINFALL WILL BE LIGHT ENOUGH TO KEEP VISIBILITY
RESTRICTIONS ABOVE IFR FOR THE MOST PART.
SURFACE WINDS GENERALLY 130-160 DEGREES SHOULD INCREASE TO 10-14 KTS
BY EARLY AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK/50
SHORT TERM...MK
LONG TERM...JAS
AVIATION...JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
926 AM EST MON DEC 15 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 355 AM EST MON DEC 15 2014
A LOW PRESSURE SYSTEM WILL BRING RAIN SHOWERS TO CENTRAL INDIANA
EARLY THIS WEEK. AFTER A DRY PERIOD UNDER HIGH PRESSURE
MIDWEEK...ANOTHER LOW PRESSURE SYSTEM WILL BRING CHANCES FOR RAIN OR
SNOW TO THE AREA THIS WEEKEND.
ABOVE AVERAGE TEMPERATURES ARE EXPECTED THROUGH TUESDAY. AFTER
THAT...SLIGHTLY BELOW NORMAL TEMPERATURES WILL TAKE OVER THROUGH THE
WEEKEND.
&&
.NEAR TERM /TODAY AND TONIGHT/...
ISSUED AT 355 AM EST MON DEC 15 2014
MAIN FOCUS FOR THE SHORT TERM WILL BE ON TIMING OF RAIN SHOWERS TO
THE AREA ALONG WITH TEMPERATURES.
MODELS IN GOOD AGREEMENT THAT A STACKED LOW PRESSURE SYSTEM OVER
SOUTH CENTRAL KANSAS EARLY THIS MORNING WILL LIFT NORTHEAST TO
SOUTHEASTERN IOWA BY 00Z THIS EVENING PROVIDING UPPER LEVEL
DIVERGENCE OVER CENTRAL INDIANA AS WELL AS DEEPENING MOISTURE.
NATIONAL RADAR LOOP WAS SHOWING AN AREA OF SHOWERS ACROSS CENTRAL
MISSOURI AND WESTERN ARKANSAS AHEAD OF THIS SYSTEM AND WITHIN
NOCTURNAL LOW LEVEL JET. THIS JET WILL MIGRATE EASTWARD AND WEAKEN A
BIT TO 35 TO 40 KNOTS WITH THE NOSE ACROSS SOUTH CENTRAL INDIANA
LATE THIS AFTERNOON. NAM12 AND HRRR RAPID REFRESH REFLECTIVITY PROGS
SUGGEST MORE OR LESS SOLID AREA OF SHOWERS SHOULD MOVE INTO OUR
SOUTHWESTERN COUNTIES AFTER 10 AM AND APPROACH INTERSTATE 65 BY 4 PM
BEFORE MOVING INTO OHIO AFTER 00Z THIS EVENING. THIS TIMING ALSO
MATCHES UP PRETTY GOOD WITH SIMILAR 00Z MODEL QPF FIELDS.
TONIGHT...TRIPLE POINT OF ASSOCIATED FRONTAL SYSTEM SHOULD LIFT
NORTHEAST ACROSS OUR NORTHERN COUNTIES RESULTING IN ANOTHER MORE
WIDESPREAD AREA OF SHOWERS LIFTING NORTHEAST ACROSS THE AREA. RAISED
QPF A BIT FROM THE 00Z SUPERBLEND AND 06Z HPC NUMBERS WITH STORM
TOTAL PRECIPITATION OF HALF AN INCH POSSIBLE. INSTABILITY PROGS
BRING SOME INSTABILITY UP CLOSE TO OUR SOUTHERN BORDER THIS
AFTERNOON AND EVENING...BUT NOT ENOUGH TO INCLUDE THUNDER AT THIS
POINT AFTER LOOKING AT LIGHTNING STRIKE TRENDS.
WENT ON THE COOL SIDE OF MOS TODAY WITH THE CLOUDS HANGING AROUND
AND RAIN MOVING IN.
&&
.SHORT TERM.../TUESDAY THROUGH WEDNESDAY NIGHT/
ISSUED AT 355 AM EST MON DEC 15 2014
SHORT TERM FOCUS IS ON POPS AS WELL AS TEMPERATURES AS A COLD FRONT
ROLLS THROUGH THE AREA LATE TUESDAY AND TUESDAY NIGHT. MODELS
CONTINUE TO AGREE THAT THE STACKED LOW WILL LIFT NORTHEAST ACROSS
SOUTHERN LOWER MICHIGAN ON TUESDAY AND A COLD FRONT WILL SLIDE
SOUTHEAST ACROSS THE AREA TUESDAY EVENING. MEANWHILE...SUFFICIENT
MOISTURE WILL LINGER THROUGH TUESDAY NIGHT WITH THE EXCEPTION OF
SOME DRYING FROM THE SOUTHWEST. THUS...WILL KEEP DECENT POPS MAINLY
NORTHEAST ON TUESDAY CLOSER TO THE BETTER FORCING AND DEEPER
MOISTURE. THEN...WILL ONLY HANG ON TO SMALL EVENING POPS NORTHEAST
TUESDAY NIGHT AS THE SYSTEM PULLS AWAY AND BECOMES ABSORBED IN AN
UPPER MIDWEST SYSTEM.
COULD SEE SOME BREAKS IN THE CLOUDS ON WEDNESDAY AND WEDNESDAY
NIGHT. HOWEVER...WILL NOT CLEAR THINGS COMPLETELY OUT AS MODEL
SOUNDINGS SHOW ANOTHER STRONG INVERSION.
WITH CLOUDS EXPECTED TO HANG AROUND ON WEDNESDAY WENT WITH THE
COOLER 00Z NAM MOS...OTHERWISE MOS TEMPERATURES CLOSE ENOUGH FOR A
BLEND.
&&
.LONG TERM /THURSDAY THROUGH NEXT SUNDAY/...
ISSUED AT 237 AM EST MON DEC 15 2014
ENSEMBLES SUGGEST THE MAIN WEATHER FEATURE DURING THIS PERIOD WILL
BE AN EJECTING UPPER DISTURBANCE WHICH IS EXPECTED TO MOVE THROUGH
THE LOCAL AREA TOWARDS THE END OF THE WEEK. THERE ARE STILL
DIFFERENCES IN THE TIMING AND TRACK OF THIS SYSTEM. THE TREND IN THE
ENSEMBLES SEEMS TO BE TOWARDS A COLDER MORE SOUTHERLY TRACK...WITH
THE MAJORITY OF THE MEMBERS NOW LEANING IN THIS DIRECTION. THERE ARE
STILL SEVERAL MEMBERS THAT SUPPORT THE MORE NORTHERLY OPERATIONAL
GFS...BUT THESE ARE IN THE MINORITY.
WILL CONTINUE WITH CHANCE POPS FOR MIXED PRECIPITATION ON FRIDAY
INTO SATURDAY FOR NOW TO COVER THE WARMER SOLUTIONS. ACCUMULATING
SNOW IS POSSIBLE BY THE END OF THE WEEK.
&&
.AVIATION /DISCUSSION FOR THE 151500Z TAF UPDATE/...
ISSUED AT 926 AM EST MON DEC 15 2014
IFR CEILINGS CONTINUE TO PLAGUE THE TERMINALS AS OF 14Z. SHOULD SEE
SOME SUBTLE IMPROVEMENTS OVER THE NEXT FEW HOURS...BUT EXPECT MVFR
STRATUS TO LINGER AT LEAST IN A SCATTERED NATURE INTO THE AFTERNOON.
TWEAKED THE TIMING ON ARRIVAL OF RAIN BASED ON CURRENT HI-RES DATA
AND ONGOING TRENDS. EXPECT SCATTERED SHOWERS AFTER 17Z IN THE WEST
WITH MORE WIDESPREAD LIGHT RAIN ARRIVING BY 20-22Z.
12Z DISCUSSION FOLLOWS.
LOW CEILINGS 004-007 AGL CURRENTLY OVER THE TAF SITES EXPECTED TO
IMPROVE FROM SOUTH TO NORTH TOWARDS THE MIDDAY HOURS AS ORGANIZED
LIFT FROM APPROACHING LOW PRESSURE SYSTEM HELPS TO BREAK UP THE
PERSISTENT LOW LEVEL INVERSION. SATELLITE LOOPS INDICATES THE BACK
EDGE OF THESE LOW CEILINGS PUSHING NORTH THROUGH FAR SOUTHERN
ILLINOIS/WESTERN KENTUCKY. CONDITIONS WILL PROBABLY IMPROVE TO VFR
BY EARLY AFTERNOON AT ALL THE TAF SITES...EXCEPT FOR MAYBE KLAF
WHERE LOWER CLOUD COVER MAY LINGER LONGER INTO THE DAY.
SHORT TERM MODEL GUIDANCE SUGGESTS RAIN WILL OVERSPREAD THE TAF
SITES FROM SOUTHWEST TO NORTHEAST AROUND 152000Z-152200Z. AT THIS
POINT...APPEARS RAINFALL WILL BE LIGHT ENOUGH TO KEEP VISIBILITY
RESTRICTIONS ABOVE IFR FOR THE MOST PART.
SURFACE WINDS GENERALLY 130-160 DEGREES SHOULD INCREASE TO 10-14 KTS
BY EARLY AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK
SHORT TERM...MK
LONG TERM...JAS
AVIATION...JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
536 AM EST MON DEC 15 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 355 AM EST MON DEC 15 2014
A LOW PRESSURE SYSTEM WILL BRING RAIN SHOWERS TO CENTRAL INDIANA
EARLY THIS WEEK. AFTER A DRY PERIOD UNDER HIGH PRESSURE
MIDWEEK...ANOTHER LOW PRESSURE SYSTEM WILL BRING CHANCES FOR RAIN OR
SNOW TO THE AREA THIS WEEKEND.
ABOVE AVERAGE TEMPERATURES ARE EXPECTED THROUGH TUESDAY. AFTER
THAT...SLIGHTLY BELOW NORMAL TEMPERATURES WILL TAKE OVER THROUGH THE
WEEKEND.
&&
.NEAR TERM /TODAY AND TONIGHT/...
ISSUED AT 355 AM EST MON DEC 15 2014
MAIN FOCUS FOR THE SHORT TERM WILL BE ON TIMING OF RAIN SHOWERS TO
THE AREA ALONG WITH TEMPERATURES.
MODELS IN GOOD AGREEMENT THAT A STACKED LOW PRESSURE SYSTEM OVER
SOUTH CENTRAL KANSAS EARLY THIS MORNING WILL LIFT NORTHEAST TO
SOUTHEASTERN IOWA BY 00Z THIS EVENING PROVIDING UPPER LEVEL
DIVERGENCE OVER CENTRAL INDIANA AS WELL AS DEEPENING MOISTURE.
NATIONAL RADAR LOOP WAS SHOWING AN AREA OF SHOWERS ACROSS CENTRAL
MISSOURI AND WESTERN ARKANSAS AHEAD OF THIS SYSTEM AND WITHIN
NOCTURNAL LOW LEVEL JET. THIS JET WILL MIGRATE EASTWARD AND WEAKEN A
BIT TO 35 TO 40 KNOTS WITH THE NOSE ACROSS SOUTH CENTRAL INDIANA
LATE THIS AFTERNOON. NAM12 AND HRRR RAPID REFRESH REFLECTIVITY PROGS
SUGGEST MORE OR LESS SOLID AREA OF SHOWERS SHOULD MOVE INTO OUR
SOUTHWESTERN COUNTIES AFTER 10 AM AND APPROACH INTERSTATE 65 BY 4 PM
BEFORE MOVING INTO OHIO AFTER 00Z THIS EVENING. THIS TIMING ALSO
MATCHES UP PRETTY GOOD WITH SIMILAR 00Z MODEL QPF FIELDS.
TONIGHT...TRIPLE POINT OF ASSOCIATED FRONTAL SYSTEM SHOULD LIFT
NORTHEAST ACROSS OUR NORTHERN COUNTIES RESULTING IN ANOTHER MORE
WIDESPREAD AREA OF SHOWERS LIFTING NORTHEAST ACROSS THE AREA. RAISED
QPF A BIT FROM THE 00Z SUPERBLEND AND 06Z HPC NUMBERS WITH STORM
TOTAL PRECIPITATION OF HALF AN INCH POSSIBLE. INSTABILITY PROGS
BRING SOME INSTABILITY UP CLOSE TO OUR SOUTHERN BORDER THIS
AFTERNOON AND EVENING...BUT NOT ENOUGH TO INCLUDE THUNDER AT THIS
POINT AFTER LOOKING AT LIGHTNING STRIKE TRENDS.
WENT ON THE COOL SIDE OF MOS TODAY WITH THE CLOUDS HANGING AROUND
AND RAIN MOVING IN.
&&
.SHORT TERM.../TUESDAY THROUGH WEDNESDAY NIGHT/
ISSUED AT 355 AM EST MON DEC 15 2014
SHORT TERM FOCUS IS ON POPS AS WELL AS TEMPERATURES AS A COLD FRONT
ROLLS THROUGH THE AREA LATE TUESDAY AND TUESDAY NIGHT. MODELS
CONTINUE TO AGREE THAT THE STACKED LOW WILL LIFT NORTHEAST ACROSS
SOUTHERN LOWER MICHIGAN ON TUESDAY AND A COLD FRONT WILL SLIDE
SOUTHEAST ACROSS THE AREA TUESDAY EVENING. MEANWHILE...SUFFICIENT
MOISTURE WILL LINGER THROUGH TUESDAY NIGHT WITH THE EXCEPTION OF
SOME DRYING FROM THE SOUTHWEST. THUS...WILL KEEP DECENT POPS MAINLY
NORTHEAST ON TUESDAY CLOSER TO THE BETTER FORCING AND DEEPER
MOISTURE. THEN...WILL ONLY HANG ON TO SMALL EVENING POPS NORTHEAST
TUESDAY NIGHT AS THE SYSTEM PULLS AWAY AND BECOMES ABSORBED IN AN
UPPER MIDWEST SYSTEM.
COULD SEE SOME BREAKS IN THE CLOUDS ON WEDNESDAY AND WEDNESDAY
NIGHT. HOWEVER...WILL NOT CLEAR THINGS COMPLETELY OUT AS MODEL
SOUNDINGS SHOW ANOTHER STRONG INVERSION.
WITH CLOUDS EXPECTED TO HANG AROUND ON WEDNESDAY WENT WITH THE
COOLER 00Z NAM MOS...OTHERWISE MOS TEMPERATURES CLOSE ENOUGH FOR A
BLEND.
&&
.LONG TERM /THURSDAY THROUGH NEXT SUNDAY/...
ISSUED AT 237 AM EST MON DEC 15 2014
ENSEMBLES SUGGEST THE MAIN WEATHER FEATURE DURING THIS PERIOD WILL
BE AN EJECTING UPPER DISTURBANCE WHICH IS EXPECTED TO MOVE THROUGH
THE LOCAL AREA TOWARDS THE END OF THE WEEK. THERE ARE STILL
DIFFERENCES IN THE TIMING AND TRACK OF THIS SYSTEM. THE TREND IN THE
ENSEMBLES SEEMS TO BE TOWARDS A COLDER MORE SOUTHERLY TRACK...WITH
THE MAJORITY OF THE MEMBERS NOW LEANING IN THIS DIRECTION. THERE ARE
STILL SEVERAL MEMBERS THAT SUPPORT THE MORE NORTHERLY OPERATIONAL
GFS...BUT THESE ARE IN THE MINORITY.
WILL CONTINUE WITH CHANCE POPS FOR MIXED PRECIPITATION ON FRIDAY
INTO SATURDAY FOR NOW TO COVER THE WARMER SOLUTIONS. ACCUMULATING
SNOW IS POSSIBLE BY THE END OF THE WEEK.
&&
.AVIATION /DISCUSSION FOR THE 151200Z TAFS/...
ISSUED AT 536 AM EST MON DEC 15 2014
LOW CEILINGS 004-007 AGL CURRENTLY OVER THE TAF SITES EXPECTED TO
IMPROVE FROM SOUTH TO NORTH TOWARDS THE MIDDAY HOURS AS ORGANIZED
LIFT FROM APPROACHING LOW PRESSURE SYSTEM HELPS TO BREAK UP THE
PERSISTENT LOW LEVEL INVERSION. SATELLITE LOOPS INDICATES THE BACK
EDGE OF THESE LOW CEILINGS PUSHING NORTH THROUGH FAR SOUTHERN
ILLINOIS/WESTERN KENTUCKY. CONDITIONS WILL PROBABLY IMPROVE TO VFR
BY EARLY AFTERNOON AT ALL THE TAF SITES...EXCEPT FOR MAYBE KLAF
WHERE LOWER CLOUD COVER MAY LINGER LONGER INTO THE DAY.
SHORT TERM MODEL GUIDANCE SUGGESTS RAIN WILL OVERSPREAD THE TAF
SITES FROM SOUTHWEST TO NORTHEAST AROUND 152000Z-152200Z. AT THIS
POINT...APPEARS RAINFALL WILL BE LIGHT ENOUGH TO KEEP VISIBILITY
RESTRICTIONS ABOVE IFR FOR THE MOST PART.
SURFACE WINDS GENERALLY 130-160 DEGREES SHOULD INCREASE TO 10-14 KTS
BY EARLY AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK
SHORT TERM...MK
LONG TERM...JAS
AVIATION...JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
704 AM EST MON DEC 15 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EST MON DEC 15 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SPLIT FLOW PATTERN WITH A
WELL DEFINED SRN STREAM SHRTWV/LOW OVER CENTRAL KS AND A NRN STREAM
SHRTWV FROM NRN MANITOBA INTO SE SASK. AN UNSEASONABLY STRONG
DOWNSTREAM RIDGE EXTENDED FROM THE SE CONUS INTO THE ERN GREAT
LAKES. A WEAKER SHORTWAVE COMBINED WITH UPPER LEVEL DIV WITH THE
RIGHT ENTRANCE OF A 90 KNOT 250MB JET OVER NRN ONTARIO SUPPORTED AN
AREA OF LIGHT RAIN AND DRIZZLE FROM NE MN INTO WRN LAKE SUPERIOR. AT
THE SFC...SSW FLOW OF MILD/MOIST AIR PREVAILED AHEAD OF A TROUGH
EXTENDING FROM N CNTRL MN TO LOW PRES OVER CENTRAL KS. DEWPOINTS TO
AROUND 40F INTO UPPER MI ABOVE THE EXTENSIVE MELTING SNOW COVER HAS
RESULTED IN AREAS OF DENSE FOG...ESPECIALLY OVER SRN UPPER MI.
DOWNSLOPE FLOW TOWARD LAKE SUPERIOR HAS LIMITED FOG OVER THE NORTH.
TODAY...EXPECT THAT THE DENSE FOG WILL LINGER THROUGH THE MORNING
AND THEN GIVE WAY TO AT LEAST SOME IMPROVEMENT BY THIS AFTERNOON
WITH SLIGHT INFLUENCE OF DIURNAL WARMING. OTHERWISE...SOME
OCCASIONAL DRIZZLE WILL ALSO BE POSSIBLE WITH THE ABUNDANT LOW LEVEL
MOISTURE THROUGH 850 MB AND SOME WEAK LIFT AIDED BY FORCING AHEAD OF
THE COMBINED INFLUENCE OF THE NRN/SRN STREAM SHRTWVS. THE DEEPEST
MOISTURE AND STRONGER LIFT THAT WOULD SUPPORT LIGHT RAIN IS EXPECTED
OVER THE WEST BY LATE TODAY.
TONIGHT...AS THE SHORTWAVES BEGIN TO PHASE AND ANOTHER JET STREAK
LIFTS THROUGH NRN ONTARIO...PCPN WILL BECOME MORE WIDESPREAD AND
SPREAD FROM WEST TO EAST. AS THE COLDER AIR MOVES IN WITH THE LOW
MOVING TOWARD LOWER MI...THE PCPN WILL CHANGE OVER TO SNOW. A BLEND
OF THE NAM/REGIONAL-GEM 1000-850 THICKNESS WAS USED TO APPROXIMATE
THE RAIN/SNOW TRANSITION WITH SNOW TO THE FAR WEST BTWN 03Z-06Z AND
INTO CNTRL UPPER MI BY 09Z-12Z. RAIN SHOULD STILL LINGER EAST OF
P53-ESC THROUGH 12Z. THERE MAY ALSO BE BRIEF PERIOD OF SLEET WITH A
LINGERING WARM NOSE NEAR 850 MB BUT SINCE IT WILL BE VERY
TRANSIENT...NO SEPARATE SLEET WORDING WAS ADDED. NRLY WINDS WITH 850
MB TEMPS DOWN TO -8C WILL ALSO BRING SOME LAKE ENHANCEMENT INTO THE
WET FOR LOCATIONS FAVORED BY NORTH WINDS WHERE SNOWFALL TOTALS
AROUND 2 INCHES ARE POSSIBLE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 305 AM EST MON DEC 15 2014
THE LONG TERM PART OF THE FORECAST WILL MARK A RETURN TO WEATHER
MORE LIKE EARLY-MID DECEMBER THAN WHAT WAS SEEN OVER THE PAST COUPLE
DAYS. MUCH OF THE FOCUS ON THE FORECAST WILL LIE WITH THE SNOWFALL
FORECAST FOR TUESDAY INTO WEDNESDAY NIGHT...BEFORE HIGH PRESSURE
BUILDS BACK INTO THE AREA FOR THE END OF THE WORK WEEK AND THE
FIRST PART OF NEXT WEEKEND.
AT 12Z TUESDAY...THERE WILL BE TWO SHORTWAVES NEAR THE GREAT LAKES
REGION...WITH THE FIRST WAVE LOCATED OVER THE LOWER GREAT LAKES AND
THE SECOND WAVE FARTHER TO THE NORTHWEST AND STRETCHING FROM
SOUTHERN HUDSON BAY THROUGH NORTHERN MINNESOTA. WHILE THERE ARE
STILL SOME SUBTLE DIFFERENCES IN THE MODELS AND HOW THEY HANDLE THE
INTERACTION OF THESE TWO FEATURES...IN GENERAL THEY ARE PRETTY
SIMILAR IN THE EVOLUTION THROUGH THURSDAY. AT THE SURFACE AT 12Z ON
TUESDAY...THERE WILL BE A 1004MB LOW OVER SOUTHERN LAKE MICHIGAN
WITH A 1009MB TROUGH STRETCHING NORTH THROUGH NORTHERN LOWER
MICHIGAN AND INTO EASTERN ONTARIO. MEANWHILE...THE 850MB TROUGH
WILL BE SLIGHTLY BACK TO THE WEST AND WORKING ITS WAY ACROSS UPPER
MICHIGAN AND LOCATED OVER THE EAST CENTRAL U.P.. EXPECT LIGHT
PRECIPITATION TO BE OCCURRING ACROSS THE CWA WITH SNOW BEHIND THE
FRONT AND RAIN/FOG EAST OF A LINE FROM GRAND MARAIS TO RAPID RIVER.
WITH THE COLD AIR CONTINUING TO PUSH EAST THROUGH THE REST OF
EASTERN UPPER MICHIGAN ON TUESDAY...EXPECT A CHANGE TO SNOW TO
OCCUR THERE. FOR TUESDAY INTO TUESDAY NIGHT...THE LOW WILL MOVE
NORTHEAST TO SOUTHWEST QUEBEC BY WEDNESDAY MORNING...WHILE LEAVING
A MID LEVEL AND SURFACE TROUGH BACK WEST OVER THE UPPER GREAT LAKES
REGION AND TIED TO THE SECONDARY SHORTWAVE SLOWLY DROPPING
SOUTH-SOUTHEAST INTO NORTHERN WISCONSIN BY WEDNESDAY MORNING. AS
THAT OCCURS...THE DEEPER MOISTURE WILL MOVE EAST OUT OF THE
WESTERN U.P. AND FOCUS OVER THE NORTHEASTERN U.P. AND EASTERN LAKE
SUPERIOR AS THE LOW LEVEL TROUGH PIVOTS THERE. THUS...WOULD EXPECT
THE POTENTIAL FOR LIGHT TO OCCASIONALLY MODERATE SNOW TO CONTINUE
THERE TUESDAY NIGHT AND EVEN INTO WEDNESDAY UNTIL THE TROUGH
PULLS OUT WEDNESDAY NIGHT.
FARTHER WEST...THE COLDER AIR SURGING INTO THE AREA (850MB TEMPS
FALLING TO -15C BY 00Z WEDNESDAY) WILL LEAD TO LAKE ENHANCED SNOW
INITIALLY AND THEN TRANSITIONING TO LAKE EFFECT AS THE DEEPER
MOISTURE PIVOTS OUT. LOW LEVEL WINDS WILL GENERALLY BE OUT OF THE
NORTH-NORTHWEST (AROUND 340 DEGREES) AS THE SURFACE-850MB TROUGH
PIVOTS OVER EASTERN LAKE SUPERIOR. WITH THE 850MB TEMPS BEING NEAR
THE TOP OF THE CLOUD LAYER...LIFT WITHIN THE DGZ WILL BE LIMITED AND
EXPECT SNOW RATIOS TO BE IN THE 12 TO 1 RANGE INITIALLY OVER THE FAR
WEST AND RISING TO THE MID TEENS. BUT HEADING CLOSER TO THE
TROUGH AND MORE INTO THE LAKE ENHANCED PRECIPITATION (FROM THE
KEWEENAW THROUGH NORTHERN CENTRAL UPPER MICHIGAN) WOULD THINK THAT
RATIOS WOULD BE A LITTLE HIGHER (UPPER TEENS) DUE TO THE LARGER AREA
THE CLOUD WILL BE IN THE DGZ. WILL CONTINUE TO SHOW DEFINITE POPS
OVER THE NORTH-NORTHWEST WIND FAVORED LOCATIONS TUESDAY AFTERNOON
THROUGH WEDNESDAY MORNING. SNOWFALL AMOUNTS FROM SYNOPTIC AND LAKE
ENHANCED/EFFECT GENERALLY AMOUNT TO 1-2 INCHES EVERY 6 HOURS OVER
THE NORTHERN TIER OR COUNTIES AND ALSO SCHOOLCRAFT AND NORTHEAST
DELTA COUNTIES. WOULD EXPECT THE HIGHEST AMOUNTS TO OCCUR OVER THE
KEWEENAW AND THEN SOUTHEAST THROUGH THE HURON MOUNTAINS TO CHATHAM
AND NEWBERRY. WHILE THE RATES DON/T LOOK TO BE THAT HIGH...THE
PERSISTENT NATURE OF THE SNOW WOULD LEAD TO AMOUNTS FROM TUESDAY
MORNING THROUGH WEDNESDAY NIGHT TO BE IN THE 5-10 INCH RANGE IN
THE HIGHEST AREAS. THEREFORE...WILL CONTINUE TO MENTION THE SNOW
POTENTIAL IN THE HWO WITH A LONG DURATION ADVISORY LIKELY
NEEDED IN THE FUTURE.
MODELS ARE CONSISTENT ON THE SURFACE-850MB TROUGH DROPPING
SOUTHEAST AND WEAKENING WEDNESDAY AFTERNOON/NIGHT...ALLOWING DRIER
AND WARMER AIR TO MOVE INTO THE AREA ON THE EAST SIDE OF THE HIGH
NEAR KINL. THIS WILL LEAD TO A VERY QUICK END TO THE LAKE
EFFECT/ENHANCED SNOW LATE WEDNESDAY NIGHT INTO THURSDAY MORNING AND
WILL FOLLOW THAT IDEA FOR THE POPS. THAT HIGH PRESSURE WILL LEAD TO
DRY AND MOSTLY CLEAR CONDITIONS FOR THE REST OF THE WORK WEEK.
MODELS DIVERGE HEADING INTO THE WEEKEND...BUT THE GENERAL IDEA IS
FOR A SHORTWAVE AND WEAK SURFACE TROUGH TO SLIDE THROUGH THE AREA AT
SOME POINT DURING THE WEEKEND. THEREFORE...WILL SHOW INCREASING
CLOUDS ON SATURDAY AND SLIGHT CHANCE POPS FOR SATURDAY NIGHT INTO
SUNDAY. HIGHS ON WEDNESDAY LOOK TO BE A TOUCH BELOW NORMAL
(LOW-MID 20S)...BUT THEN EXPECT A GRADUAL WARM UP TO ABOVE NORMAL
VALUES BY SATURDAY (UPPER 20S AND LOWER 30S) WITH THE RELATIVELY
WARM NORTHERLY FLOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 704 AM EST MON DEC 15 2014
CMX...EXPECT LIFR CONDITIONS WITH A SRLY DOWNSLOPE WIND LIMITING
POTENTIAL FOR CIGS/VIS TO DROP TO LANDING MINS. THE LIFR/IFR
CONDITIONS WILL PERSIST INTO MON AFTERNOON WHEN THE ARRIVAL OF SOME
DEEPER MOISTURE AND RAIN/DRIZZLE ASSOCIATED WITH A COLD FRONT
BRINGS CONTINUED LOWER CIGS INTO THE LIFR. COLDER AIR MOVING IN
AFTER MIDNIGHT WILL BRING A TRANSITION FROM RAIN TO SNOW WITH
CONTINUED IFR/LIFT CONDITIONS.
IWD....EXPECT IFR CONDITIONS TO PREVAIL THROUGH THIS MORNING
WITH A MOIST FLOW OVER THE MELTING SNOW PACK. THE APPROACH OF A COLD
FRONT/ARRIVAL OF EVEN DEEPER MOISTURE WILL CAUSE LIFR CONDITIONS BY
LATE AFTERNOON. THE RAIN WILL CHANGE TO SNOW BY LATE EVENING
AS COLDER AIR RETURNS...RESULTING IN A PERSISTENCE OF LIFR
CONDITIONS WITH AN UPSLOPE N WIND.
SAW...EXPECT PERSISTENT VLIFR CONDITIONS AT OR BELOW LANDING
MINIMUMS. EXPECT A SLOW IMPROVEMENT TO IFR IN THE AFTN. FOLLOWING
THE PASSAGE OF A COLD FNT THIS EVNG AND A DVLPG UPSLOPE N WIND/SOME
RA...A RETURN TO LIFR WX IS FORECAST. WITH THE ARRIVAL OF COLDER AIR
TOWARD THE END OF THE FCST PERIOD...THE RAIN WILL CHANGE TO SNOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 534 AM EST MON DEC 15 2014
PATCHY FOG WILL LINGER ACROSS MUCH OF LAKE SUPERIOR TODAY AS THE AREA
REMAINS IN THE WARM/MOIST AIRMASS. A LOW ACROSS MINNESOTA WILL PUSH
OVER WESTERN LAKE SUPERIOR THIS AFTERNOON...AND THEN E LAKE SUPERIOR
THIS EVENING REDUCING THE FOG. THE SRN PORTION OF THE TROUGH WILL
SHIFT FROM KS TO IA TODAY AND TO 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...
DENSE FOG ADVISORY UNTIL NOON EST /11 AM CST/ TODAY FOR
MIZ004>007-010>014-084-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR LMZ221-248-
250.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
535 AM EST MON DEC 15 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EST MON DEC 15 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SPLIT FLOW PATTERN WITH A
WELL DEFINED SRN STREAM SHRTWV/LOW OVER CENTRAL KS AND A NRN STREAM
SHRTWV FROM NRN MANITOBA INTO SE SASK. AN UNSEASONABLY STRONG
DOWNSTREAM RIDGE EXTENDED FROM THE SE CONUS INTO THE ERN GREAT
LAKES. A WEAKER SHORTWAVE COMBINED WITH UPPER LEVEL DIV WITH THE
RIGHT ENTRANCE OF A 90 KNOT 250MB JET OVER NRN ONTARIO SUPPORTED AN
AREA OF LIGHT RAIN AND DRIZZLE FROM NE MN INTO WRN LAKE SUPERIOR. AT
THE SFC...SSW FLOW OF MILD/MOIST AIR PREVAILED AHEAD OF A TROUGH
EXTENDING FROM N CNTRL MN TO LOW PRES OVER CENTRAL KS. DEWPOINTS TO
AROUND 40F INTO UPPER MI ABOVE THE EXTENSIVE MELTING SNOW COVER HAS
RESULTED IN AREAS OF DENSE FOG...ESPECIALLY OVER SRN UPPER MI.
DOWNSLOPE FLOW TOWARD LAKE SUPERIOR HAS LIMITED FOG OVER THE NORTH.
TODAY...EXPECT THAT THE DENSE FOG WILL LINGER THROUGH THE MORNING
AND THEN GIVE WAY TO AT LEAST SOME IMPROVEMENT BY THIS AFTERNOON
WITH SLIGHT INFLUENCE OF DIURNAL WARMING. OTHERWISE...SOME
OCCASIONAL DRIZZLE WILL ALSO BE POSSIBLE WITH THE ABUNDANT LOW LEVEL
MOISTURE THROUGH 850 MB AND SOME WEAK LIFT AIDED BY FORCING AHEAD OF
THE COMBINED INFLUENCE OF THE NRN/SRN STREAM SHRTWVS. THE DEEPEST
MOISTURE AND STRONGER LIFT THAT WOULD SUPPORT LIGHT RAIN IS EXPECTED
OVER THE WEST BY LATE TODAY.
TONIGHT...AS THE SHORTWAVES BEGIN TO PHASE AND ANOTHER JET STREAK
LIFTS THROUGH NRN ONTARIO...PCPN WILL BECOME MORE WIDESPREAD AND
SPREAD FROM WEST TO EAST. AS THE COLDER AIR MOVES IN WITH THE LOW
MOVING TOWARD LOWER MI...THE PCPN WILL CHANGE OVER TO SNOW. A BLEND
OF THE NAM/REGIONAL-GEM 1000-850 THICKNESS WAS USED TO APPROXIMATE
THE RAIN/SNOW TRANSITION WITH SNOW TO THE FAR WEST BTWN 03Z-06Z AND
INTO CNTRL UPPER MI BY 09Z-12Z. RAIN SHOULD STILL LINGER EAST OF
P53-ESC THROUGH 12Z. THERE MAY ALSO BE BRIEF PERIOD OF SLEET WITH A
LINGERING WARM NOSE NEAR 850 MB BUT SINCE IT WILL BE VERY
TRANSIENT...NO SEPARATE SLEET WORDING WAS ADDED. NRLY WINDS WITH 850
MB TEMPS DOWN TO -8C WILL ALSO BRING SOME LAKE ENHANCEMENT INTO THE
WET FOR LOCATIONS FAVORED BY NORTH WINDS WHERE SNOWFALL TOTALS
AROUND 2 INCHES ARE POSSIBLE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 305 AM EST MON DEC 15 2014
THE LONG TERM PART OF THE FORECAST WILL MARK A RETURN TO WEATHER
MORE LIKE EARLY-MID DECEMBER THAN WHAT WAS SEEN OVER THE PAST COUPLE
DAYS. MUCH OF THE FOCUS ON THE FORECAST WILL LIE WITH THE SNOWFALL
FORECAST FOR TUESDAY INTO WEDNESDAY NIGHT...BEFORE HIGH PRESSURE
BUILDS BACK INTO THE AREA FOR THE END OF THE WORK WEEK AND THE
FIRST PART OF NEXT WEEKEND.
AT 12Z TUESDAY...THERE WILL BE TWO SHORTWAVES NEAR THE GREAT LAKES
REGION...WITH THE FIRST WAVE LOCATED OVER THE LOWER GREAT LAKES AND
THE SECOND WAVE FARTHER TO THE NORTHWEST AND STRETCHING FROM
SOUTHERN HUDSON BAY THROUGH NORTHERN MINNESOTA. WHILE THERE ARE
STILL SOME SUBTLE DIFFERENCES IN THE MODELS AND HOW THEY HANDLE THE
INTERACTION OF THESE TWO FEATURES...IN GENERAL THEY ARE PRETTY
SIMILAR IN THE EVOLUTION THROUGH THURSDAY. AT THE SURFACE AT 12Z ON
TUESDAY...THERE WILL BE A 1004MB LOW OVER SOUTHERN LAKE MICHIGAN
WITH A 1009MB TROUGH STRETCHING NORTH THROUGH NORTHERN LOWER
MICHIGAN AND INTO EASTERN ONTARIO. MEANWHILE...THE 850MB TROUGH
WILL BE SLIGHTLY BACK TO THE WEST AND WORKING ITS WAY ACROSS UPPER
MICHIGAN AND LOCATED OVER THE EAST CENTRAL U.P.. EXPECT LIGHT
PRECIPITATION TO BE OCCURRING ACROSS THE CWA WITH SNOW BEHIND THE
FRONT AND RAIN/FOG EAST OF A LINE FROM GRAND MARAIS TO RAPID RIVER.
WITH THE COLD AIR CONTINUING TO PUSH EAST THROUGH THE REST OF
EASTERN UPPER MICHIGAN ON TUESDAY...EXPECT A CHANGE TO SNOW TO
OCCUR THERE. FOR TUESDAY INTO TUESDAY NIGHT...THE LOW WILL MOVE
NORTHEAST TO SOUTHWEST QUEBEC BY WEDNESDAY MORNING...WHILE LEAVING
A MID LEVEL AND SURFACE TROUGH BACK WEST OVER THE UPPER GREAT LAKES
REGION AND TIED TO THE SECONDARY SHORTWAVE SLOWLY DROPPING
SOUTH-SOUTHEAST INTO NORTHERN WISCONSIN BY WEDNESDAY MORNING. AS
THAT OCCURS...THE DEEPER MOISTURE WILL MOVE EAST OUT OF THE
WESTERN U.P. AND FOCUS OVER THE NORTHEASTERN U.P. AND EASTERN LAKE
SUPERIOR AS THE LOW LEVEL TROUGH PIVOTS THERE. THUS...WOULD EXPECT
THE POTENTIAL FOR LIGHT TO OCCASIONALLY MODERATE SNOW TO CONTINUE
THERE TUESDAY NIGHT AND EVEN INTO WEDNESDAY UNTIL THE TROUGH
PULLS OUT WEDNESDAY NIGHT.
FARTHER WEST...THE COLDER AIR SURGING INTO THE AREA (850MB TEMPS
FALLING TO -15C BY 00Z WEDNESDAY) WILL LEAD TO LAKE ENHANCED SNOW
INITIALLY AND THEN TRANSITIONING TO LAKE EFFECT AS THE DEEPER
MOISTURE PIVOTS OUT. LOW LEVEL WINDS WILL GENERALLY BE OUT OF THE
NORTH-NORTHWEST (AROUND 340 DEGREES) AS THE SURFACE-850MB TROUGH
PIVOTS OVER EASTERN LAKE SUPERIOR. WITH THE 850MB TEMPS BEING NEAR
THE TOP OF THE CLOUD LAYER...LIFT WITHIN THE DGZ WILL BE LIMITED AND
EXPECT SNOW RATIOS TO BE IN THE 12 TO 1 RANGE INITIALLY OVER THE FAR
WEST AND RISING TO THE MID TEENS. BUT HEADING CLOSER TO THE
TROUGH AND MORE INTO THE LAKE ENHANCED PRECIPITATION (FROM THE
KEWEENAW THROUGH NORTHERN CENTRAL UPPER MICHIGAN) WOULD THINK THAT
RATIOS WOULD BE A LITTLE HIGHER (UPPER TEENS) DUE TO THE LARGER AREA
THE CLOUD WILL BE IN THE DGZ. WILL CONTINUE TO SHOW DEFINITE POPS
OVER THE NORTH-NORTHWEST WIND FAVORED LOCATIONS TUESDAY AFTERNOON
THROUGH WEDNESDAY MORNING. SNOWFALL AMOUNTS FROM SYNOPTIC AND LAKE
ENHANCED/EFFECT GENERALLY AMOUNT TO 1-2 INCHES EVERY 6 HOURS OVER
THE NORTHERN TIER OR COUNTIES AND ALSO SCHOOLCRAFT AND NORTHEAST
DELTA COUNTIES. WOULD EXPECT THE HIGHEST AMOUNTS TO OCCUR OVER THE
KEWEENAW AND THEN SOUTHEAST THROUGH THE HURON MOUNTAINS TO CHATHAM
AND NEWBERRY. WHILE THE RATES DON/T LOOK TO BE THAT HIGH...THE
PERSISTENT NATURE OF THE SNOW WOULD LEAD TO AMOUNTS FROM TUESDAY
MORNING THROUGH WEDNESDAY NIGHT TO BE IN THE 5-10 INCH RANGE IN
THE HIGHEST AREAS. THEREFORE...WILL CONTINUE TO MENTION THE SNOW
POTENTIAL IN THE HWO WITH A LONG DURATION ADVISORY LIKELY
NEEDED IN THE FUTURE.
MODELS ARE CONSISTENT ON THE SURFACE-850MB TROUGH DROPPING
SOUTHEAST AND WEAKENING WEDNESDAY AFTERNOON/NIGHT...ALLOWING DRIER
AND WARMER AIR TO MOVE INTO THE AREA ON THE EAST SIDE OF THE HIGH
NEAR KINL. THIS WILL LEAD TO A VERY QUICK END TO THE LAKE
EFFECT/ENHANCED SNOW LATE WEDNESDAY NIGHT INTO THURSDAY MORNING AND
WILL FOLLOW THAT IDEA FOR THE POPS. THAT HIGH PRESSURE WILL LEAD TO
DRY AND MOSTLY CLEAR CONDITIONS FOR THE REST OF THE WORK WEEK.
MODELS DIVERGE HEADING INTO THE WEEKEND...BUT THE GENERAL IDEA IS
FOR A SHORTWAVE AND WEAK SURFACE TROUGH TO SLIDE THROUGH THE AREA AT
SOME POINT DURING THE WEEKEND. THEREFORE...WILL SHOW INCREASING
CLOUDS ON SATURDAY AND SLIGHT CHANCE POPS FOR SATURDAY NIGHT INTO
SUNDAY. HIGHS ON WEDNESDAY LOOK TO BE A TOUCH BELOW NORMAL
(LOW-MID 20S)...BUT THEN EXPECT A GRADUAL WARM UP TO ABOVE NORMAL
VALUES BY SATURDAY (UPPER 20S AND LOWER 30S) WITH THE RELATIVELY
WARM NORTHERLY FLOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 624 PM EST SUN DEC 14 2014
CMX...EXPECT DENSE FOG/VLIFR CONDITIONS TO IMPROVE TOWARD IFR BY
MIDNGT AS THE WIND SHIFTS FM THE E TO A MORE DOWNSLOPE S DIRECTION.
THESE IFR CONDITIONS WL PERSIST INTO MON AFTN WHEN THE ARRIVAL OF
SOME DEEPER MSTR/-RA OR -DZ CAUSES A RETURN OF LIFR WX.
IWD...DOWNSLOPE S WIND WL OFFSET DIURNAL COOLING AND THE ADVECTION
OF MOISTER AIR THIS EVNG AND RESULT IN ONLY A SLOW DESCENT TOWARD
MVFR BY MIDNGT AND POSSIBLY IFR CONDITIONS VERY LATE. THE APPROACH
OF A COLD FNT/ARRIVAL OF DEEPER MSTR ON MON AFTN AND WEAKENING
DOWNSLOPE WIND COMPONENT WL CAUSE LIFR CONDITIONS BY LATE AFTN.
SAW...AS MOISTER LLVL AIR OFF LK MI ARRIVES THIS EVNG IN THE
PRESENCE OF DIURNAL COOLING...EXPECT CONDITIONS TO DETERIORATE TO
LIFR BY LATE EVNG AND THEN TO VLIFR OVERNGT THRU MON MRNG. EXPECT A
SLOW IMPROVEMENT TO IFR IN THE AFTN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 534 AM EST MON DEC 15 2014
PATCHY FOG WILL LINGER ACROSS MUCH OF LAKE SUPERIOR TODAY AS THE AREA
REMAINS IN THE WARM/MOIST AIRMASS. A LOW ACROSS MINNESOTA WILL PUSH
OVER WESTERN LAKE SUPERIOR THIS AFTERNOON...AND THEN E LAKE SUPERIOR
THIS EVENING REDUCING THE FOG. THE SRN PORTION OF THE TROUGH WILL
SHIFT FROM KS TO IA TODAY AND TO 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...
DENSE FOG ADVISORY UNTIL NOON EST /11 AM CST/ TODAY FOR
MIZ004>007-010>014-084-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR LMZ221-248-
250.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
521 AM EST MON DEC 15 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EST MON DEC 15 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SPLIT FLOW PATTERN WITH A
WELL DEFINED SRN STREAM SHRTWV/LOW OVER CENTRAL KS AND A NRN STREAM
SHRTWV FROM NRN MANITOBA INTO SE SASK. AN UNSEASONABLY STRONG
DOWNSTREAM RIDGE EXTENDED FROM THE SE CONUS INTO THE ERN GREAT
LAKES. A WEAKER SHORTWAVE COMBINED WITH UPPER LEVEL DIV WITH THE
RIGHT ENTRANCE OF A 90 KNOT 250MB JET OVER NRN ONTARIO SUPPORTED AN
AREA OF LIGHT RAIN AND DRIZZLE FROM NE MN INTO WRN LAKE SUPERIOR. AT
THE SFC...SSW FLOW OF MILD/MOIST AIR PREVAILED AHEAD OF A TROUGH
EXTENDING FROM N CNTRL MN TO LOW PRES OVER CENTRAL KS. DEWPOINTS TO
AROUND 40F INTO UPPER MI ABOVE THE EXTENSIVE MELTING SNOW COVER HAS
RESULTED IN AREAS OF DENSE FOG...ESPECIALLY OVER SRN UPPER MI.
DOWNSLOPE FLOW TOWARD LAKE SUPERIOR HAS LIMITED FOG OVER THE NORTH.
TODAY...EXPECT THAT THE DENSE FOG WILL LINGER THROUGH THE MORNING
AND THEN GIVE WAY TO AT LEAST SOME IMPROVEMENT BY THIS AFTERNOON
WITH SLIGHT INFLUENCE OF DIURNAL WARMING. OTHERWISE...SOME
OCCASIONAL DRIZZLE WILL ALSO BE POSSIBLE WITH THE ABUNDANT LOW LEVEL
MOISTURE THROUGH 850 MB AND SOME WEAK LIFT AIDED BY FORCING AHEAD OF
THE COMBINED INFLUENCE OF THE NRN/SRN STREAM SHRTWVS. THE DEEPEST
MOISTURE AND STRONGER LIFT THAT WOULD SUPPORT LIGHT RAIN IS EXPECTED
OVER THE WEST BY LATE TODAY.
TONIGHT...AS THE SHORTWAVES BEGIN TO PHASE AND ANOTHER JET STREAK
LIFTS THROUGH NRN ONTARIO...PCPN WILL BECOME MORE WIDESPREAD AND
SPREAD FROM WEST TO EAST. AS THE COLDER AIR MOVES IN WITH THE LOW
MOVING TOWARD LOWER MI...THE PCPN WILL CHANGE OVER TO SNOW. A BLEND
OF THE NAM/REGIONAL-GEM 1000-850 THICKNESS WAS USED TO APPROXIMATE
THE RAIN/SNOW TRANSITION WITH SNOW TO THE FAR WEST BTWN 03Z-06Z AND
INTO CNTRL UPPER MI BY 09Z-12Z. RAIN SHOULD STILL LINGER EAST OF
P53-ESC THROUGH 12Z. THERE MAY ALSO BE BRIEF PERIOD OF SLEET WITH A
LINGERING WARM NOSE NEAR 850 MB BUT SINCE IT WILL BE VERY
TRANSIENT...NO SEPARATE SLEET WORDING WAS ADDED. NRLY WINDS WITH 850
MB TEMPS DOWN TO -8C WILL ALSO BRING SOME LAKE ENHANCEMENT INTO THE
WET FOR LOCATIONS FAVORED BY NORTH WINDS WHERE SNOWFALL TOTALS
AROUND 2 INCHES ARE POSSIBLE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 305 AM EST MON DEC 15 2014
THE LONG TERM PART OF THE FORECAST WILL MARK A RETURN TO WEATHER
MORE LIKE EARLY-MID DECEMBER THAN WHAT WAS SEEN OVER THE PAST COUPLE
DAYS. MUCH OF THE FOCUS ON THE FORECAST WILL LIE WITH THE SNOWFALL
FORECAST FOR TUESDAY INTO WEDNESDAY NIGHT...BEFORE HIGH PRESSURE
BUILDS BACK INTO THE AREA FOR THE END OF THE WORK WEEK AND THE
FIRST PART OF NEXT WEEKEND.
AT 12Z TUESDAY...THERE WILL BE TWO SHORTWAVES NEAR THE GREAT LAKES
REGION...WITH THE FIRST WAVE LOCATED OVER THE LOWER GREAT LAKES AND
THE SECOND WAVE FARTHER TO THE NORTHWEST AND STRETCHING FROM
SOUTHERN HUDSON BAY THROUGH NORTHERN MINNESOTA. WHILE THERE ARE
STILL SOME SUBTLE DIFFERENCES IN THE MODELS AND HOW THEY HANDLE THE
INTERACTION OF THESE TWO FEATURES...IN GENERAL THEY ARE PRETTY
SIMILAR IN THE EVOLUTION THROUGH THURSDAY. AT THE SURFACE AT 12Z ON
TUESDAY...THERE WILL BE A 1004MB LOW OVER SOUTHERN LAKE MICHIGAN
WITH A 1009MB TROUGH STRETCHING NORTH THROUGH NORTHERN LOWER
MICHIGAN AND INTO EASTERN ONTARIO. MEANWHILE...THE 850MB TROUGH
WILL BE SLIGHTLY BACK TO THE WEST AND WORKING ITS WAY ACROSS UPPER
MICHIGAN AND LOCATED OVER THE EAST CENTRAL U.P.. EXPECT LIGHT
PRECIPITATION TO BE OCCURRING ACROSS THE CWA WITH SNOW BEHIND THE
FRONT AND RAIN/FOG EAST OF A LINE FROM GRAND MARAIS TO RAPID RIVER.
WITH THE COLD AIR CONTINUING TO PUSH EAST THROUGH THE REST OF
EASTERN UPPER MICHIGAN ON TUESDAY...EXPECT A CHANGE TO SNOW TO
OCCUR THERE. FOR TUESDAY INTO TUESDAY NIGHT...THE LOW WILL MOVE
NORTHEAST TO SOUTHWEST QUEBEC BY WEDNESDAY MORNING...WHILE LEAVING
A MID LEVEL AND SURFACE TROUGH BACK WEST OVER THE UPPER GREAT LAKES
REGION AND TIED TO THE SECONDARY SHORTWAVE SLOWLY DROPPING
SOUTH-SOUTHEAST INTO NORTHERN WISCONSIN BY WEDNESDAY MORNING. AS
THAT OCCURS...THE DEEPER MOISTURE WILL MOVE EAST OUT OF THE
WESTERN U.P. AND FOCUS OVER THE NORTHEASTERN U.P. AND EASTERN LAKE
SUPERIOR AS THE LOW LEVEL TROUGH PIVOTS THERE. THUS...WOULD EXPECT
THE POTENTIAL FOR LIGHT TO OCCASIONALLY MODERATE SNOW TO CONTINUE
THERE TUESDAY NIGHT AND EVEN INTO WEDNESDAY UNTIL THE TROUGH
PULLS OUT WEDNESDAY NIGHT.
FARTHER WEST...THE COLDER AIR SURGING INTO THE AREA (850MB TEMPS
FALLING TO -15C BY 00Z WEDNESDAY) WILL LEAD TO LAKE ENHANCED SNOW
INITIALLY AND THEN TRANSITIONING TO LAKE EFFECT AS THE DEEPER
MOISTURE PIVOTS OUT. LOW LEVEL WINDS WILL GENERALLY BE OUT OF THE
NORTH-NORTHWEST (AROUND 340 DEGREES) AS THE SURFACE-850MB TROUGH
PIVOTS OVER EASTERN LAKE SUPERIOR. WITH THE 850MB TEMPS BEING NEAR
THE TOP OF THE CLOUD LAYER...LIFT WITHIN THE DGZ WILL BE LIMITED AND
EXPECT SNOW RATIOS TO BE IN THE 12 TO 1 RANGE INITIALLY OVER THE FAR
WEST AND RISING TO THE MID TEENS. BUT HEADING CLOSER TO THE
TROUGH AND MORE INTO THE LAKE ENHANCED PRECIPITATION (FROM THE
KEWEENAW THROUGH NORTHERN CENTRAL UPPER MICHIGAN) WOULD THINK THAT
RATIOS WOULD BE A LITTLE HIGHER (UPPER TEENS) DUE TO THE LARGER AREA
THE CLOUD WILL BE IN THE DGZ. WILL CONTINUE TO SHOW DEFINITE POPS
OVER THE NORTH-NORTHWEST WIND FAVORED LOCATIONS TUESDAY AFTERNOON
THROUGH WEDNESDAY MORNING. SNOWFALL AMOUNTS FROM SYNOPTIC AND LAKE
ENHANCED/EFFECT GENERALLY AMOUNT TO 1-2 INCHES EVERY 6 HOURS OVER
THE NORTHERN TIER OR COUNTIES AND ALSO SCHOOLCRAFT AND NORTHEAST
DELTA COUNTIES. WOULD EXPECT THE HIGHEST AMOUNTS TO OCCUR OVER THE
KEWEENAW AND THEN SOUTHEAST THROUGH THE HURON MOUNTAINS TO CHATHAM
AND NEWBERRY. WHILE THE RATES DON/T LOOK TO BE THAT HIGH...THE
PERSISTENT NATURE OF THE SNOW WOULD LEAD TO AMOUNTS FROM TUESDAY
MORNING THROUGH WEDNESDAY NIGHT TO BE IN THE 5-10 INCH RANGE IN
THE HIGHEST AREAS. THEREFORE...WILL CONTINUE TO MENTION THE SNOW
POTENTIAL IN THE HWO WITH A LONG DURATION ADVISORY LIKELY
NEEDED IN THE FUTURE.
MODELS ARE CONSISTENT ON THE SURFACE-850MB TROUGH DROPPING
SOUTHEAST AND WEAKENING WEDNESDAY AFTERNOON/NIGHT...ALLOWING DRIER
AND WARMER AIR TO MOVE INTO THE AREA ON THE EAST SIDE OF THE HIGH
NEAR KINL. THIS WILL LEAD TO A VERY QUICK END TO THE LAKE
EFFECT/ENHANCED SNOW LATE WEDNESDAY NIGHT INTO THURSDAY MORNING AND
WILL FOLLOW THAT IDEA FOR THE POPS. THAT HIGH PRESSURE WILL LEAD TO
DRY AND MOSTLY CLEAR CONDITIONS FOR THE REST OF THE WORK WEEK.
MODELS DIVERGE HEADING INTO THE WEEKEND...BUT THE GENERAL IDEA IS
FOR A SHORTWAVE AND WEAK SURFACE TROUGH TO SLIDE THROUGH THE AREA AT
SOME POINT DURING THE WEEKEND. THEREFORE...WILL SHOW INCREASING
CLOUDS ON SATURDAY AND SLIGHT CHANCE POPS FOR SATURDAY NIGHT INTO
SUNDAY. HIGHS ON WEDNESDAY LOOK TO BE A TOUCH BELOW NORMAL
(LOW-MID 20S)...BUT THEN EXPECT A GRADUAL WARM UP TO ABOVE NORMAL
VALUES BY SATURDAY (UPPER 20S AND LOWER 30S) WITH THE RELATIVELY
WARM NORTHERLY FLOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 624 PM EST SUN DEC 14 2014
CMX...EXPECT DENSE FOG/VLIFR CONDITIONS TO IMPROVE TOWARD IFR BY
MIDNGT AS THE WIND SHIFTS FM THE E TO A MORE DOWNSLOPE S DIRECTION.
THESE IFR CONDITIONS WL PERSIST INTO MON AFTN WHEN THE ARRIVAL OF
SOME DEEPER MSTR/-RA OR -DZ CAUSES A RETURN OF LIFR WX.
IWD...DOWNSLOPE S WIND WL OFFSET DIURNAL COOLING AND THE ADVECTION
OF MOISTER AIR THIS EVNG AND RESULT IN ONLY A SLOW DESCENT TOWARD
MVFR BY MIDNGT AND POSSIBLY IFR CONDITIONS VERY LATE. THE APPROACH
OF A COLD FNT/ARRIVAL OF DEEPER MSTR ON MON AFTN AND WEAKENING
DOWNSLOPE WIND COMPONENT WL CAUSE LIFR CONDITIONS BY LATE AFTN.
SAW...AS MOISTER LLVL AIR OFF LK MI ARRIVES THIS EVNG IN THE
PRESENCE OF DIURNAL COOLING...EXPECT CONDITIONS TO DETERIORATE TO
LIFR BY LATE EVNG AND THEN TO VLIFR OVERNGT THRU MON MRNG. EXPECT A
SLOW IMPROVEMENT TO IFR IN THE AFTN.
&&
.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...
DENSE FOG ADVISORY UNTIL NOON EST /11 AM CST/ TODAY FOR
MIZ004>007-010>014-084-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR LMZ221-248-
250.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
947 AM CST MON DEC 15 2014
.UPDATE...
ISSUED AT 945 AM CST MON DEC 15 2014
MADE ADJUSTMENTS TO CURRENT HEADLINES. EXPIRED ADVISORY CENTRAL
AND NORTHERN VALLEY AND ADJACENT AREAS OF NW MN. CANNOT RULE OUT
SOME ISOLATED POCKETS OF -FZDZ HOWEVER SHOULD NOT BE ENOUGH TO
AFFECT ROADWAYS. EXTENDED ADVISORY UNTIL 1 PM FOR AREAS ALONG AND
SOUTH-EAST OF A LINE FROM BAUDETTE TO FOSSTON...FARGO AND VALLEY CITY.
STILL GETTING REPORTS OF MORE SIGNIFICANT WINTRY MIX AND HAZARDOUS TRAVEL.
WILL REVISIT EARLY THIS AFTERNOON TO SEE IF ANY AREAS ACROSS WEST
CENTRAL TO NORTH CENTRAL MN WILL NEED AN EXTENSION IN TIME. NO
OTHER SIGNIFICANT CHANGES.
UPDATE ISSUED AT 645 AM CST MON DEC 15 2014
MOST OF THE FREEZING DRIZZLE HAS MOVED SOUTH AND EAST OUT OF THE
GFK AREA...BUT WITH RECENT WET CONDITIONS AND COLD TEMPS
CONDITIONS CONTINUE TO BE SLICK. IN ADDITION...MORE RETURNS ARE
STARTING TO DEVELOP OVER THE SOUTHERN FORECAST AREA AND SHOULD
CONTINUE OVER THE NEXT FEW HOURS. THUS WILL KEEP THE ADVISORY
GOING FOR NOW.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 402 AM CST MON DEC 15 2014
MAIN HEADACHE IS FREEZING DRIZZLE AND HOW LONG IT WILL LAST TODAY.
THE SPLIT FLOW ALOFT CONTINUES WITH THE NORTHERN BRANCH SHORTWAVE
DIGGING DOWN THROUGH SOUTHERN CANADA AND THE SOUTHERN CUT OFF LOW
MOVING THROUGH KANSAS ON ITS WAY TO IOWA. THE SFC LOW HAS MOVED TO
THE EAST OF THE CWA AND MOST SITES HAVE SEEN A SHIFT TO
NORTHWESTERLY WINDS AND GOOD COLD AIR ADVECTION. A FEW SPOTS IN
THE EASTERN TIER ARE HANGING ABOVE FREEZING BUT THE REST HAVE
FALLEN BELOW. LOW LEVEL MOISTURE CONTINUES TO BE ABUNDANT EVEN
BEHIND THE COLD FRONT AND MODEL SOUNDINGS INDICATE A DRY LAYER
ALOFT WHERE TEMPS WOULD BE COLD ENOUGH FOR ICE GROWTH...SO MOST OF
OUR PRECIP WILL BE SUPERCOOLED WATER. THE RAP AND NAM BOTH HAVE
THE LOW LEVEL OMEGA IN THAT SATURATED LAYER CONTINUING TO SHOW
SOME RISING MOTION. WILL EXTEND THE FREEZING RAIN ADVISORY UNTIL
15Z AND EXTEND IT EAST AS TEMPS HAVE BEEN FALLING AND VIS HAVE
BEEN RISING WHERE OUR DENSE FOG HEADLINE WAS OVER THE EASTERN
COUNTIES.
THE SOUTHERN BRANCH SHORTWAVE WILL STAY MAINLY TO OUR SOUTHEAST
TODAY...BUT KEPT SOME LOW POPS TO BLEND IN AS THE SYSTEM PASSES
BY. TONIGHT...THE NORTHERN BRANCH SHORTWAVE WILL DIG DOWN INTO
NORTHEASTERN MN AND SFC HIGH PRESSURE WILL BUILD INTO THE WESTERN
PLAINS. SAT LOOP SHOWS FAIRLY CONSISTENT CLOUDS WELL TO OUR NORTH
AND WEST UNTIL ON THE WEST SIDE OF THE SFC RIDGE CURRENTLY ALONG
THE SASKATCHEWAN/ALBERTA BORDER. TIME HEIGHTS CONTINUE TO SHOW A
LOT OF RH AT LOW LEVELS SO THINK THAT CLOUDS WILL HANG ON LONGER
THAN EXPECTED. BUMPED UP CLOUDS AND RAISED LOWS A FEW DEGREES
ACCORDINGLY FOR TONIGHT.
TUESDAY...THE SFC HIGH PRESSURE WILL MOVE EASTWARD INTO THE
CWA...BUT THE AXIS WILL STILL BE WEST OF MOST OF OUR COUNTIES SO
KEPT CLOUDS HIGHER A BIT LONGER ALTHOUGH NOT COMPLETELY SOCKED IN.
EVEN WITH A BIT OF SUN COLD AIR ADVECTION WILL KEEP THE TEMPS IN
THE TEENS FOR TUESDAY AND WITH BREEZY NORTHWEST WINDS IT WILL FEEL
RATHER RAW.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 AM CST MON DEC 15 2014
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...SPLIT FLOW CONTINUES WITH
SFC HIGH PRESSURE CONTINUING OVER THE REGION. TEMPS WILL REMAIN
COLD EVEN AS CLOUDS START TO DECREASE. LOWS WILL BE IN THE SINGLE
DIGITS AND HIGHS IN THE TEENS.
THURSDAY THROUGH SUNDAY...LONG WAVE TROUGH OFF THE WEST COAST OF
CANADA REMAINS THROUGH DAY 5 THEN RETROGRADES/RE-ESTABLISH
FARTHER WEST THROUGH THE END OF THE PERIOD. SPLIT FLOW CONTINUES
ACROSS NORTH AMERICA THROUGH THE PERIOD. FLOW ALOFT REMAINS
RELATIVELY PROGRESSIVE THROUGH THE PERIOD. MUCH ABOVE NORMAL
HEIGHTS REMAIN OVER HUDSON BAY AND SOUTHERN CANADA.
GFS AND ECMWF WERE SIMILAR AT THE BEGINNING OF THE PERIOD. HOWEVER
THE GFS WANT TO DEVELOP A STRONGER TROUGH OVER CENTRAL
CANADA/NORTHERN PLAINS ON FRI AND SAT WHICH IS OUT OF PHASE WITH THE
ECMWF FOR THE REST OF THE PERIOD. WILL PREFER THE ECMWF.
LITTLE OR NO PRECIP THROUGH THE EXTENDED FORECAST. LITTLE CHANGE TO
TEMPS ON THU AND FRI. HIGH TEMPS DECREASED A DEGREE OR TWO FOR SAT
AND SUN MOST PLACES COMPARED TO THE PREVIOUS FORECAST PACKAGE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 645 AM CST MON DEC 15 2014
IFR CONDITIONS CONTINUE AT MOST TAF SITES WITH SOME MVFR AT KDVL.
KBJI AND KFAR CONTINUE TO HAVE SOME RESTRICTIONS TO VISIBILITY
WITH MIST AND FREEZING RAIN...BUT GENERALLY IN THE 3-5SM RANGE.
VIS WILL CONTINUE TO IMPROVE AND CIGS SHOULD SLOWLY RISE TO MVFR
BY LATER THIS AFTERNOON IN MOST AREAS. NORTHWEST WIND WILL BE
SUSTAINED AT 20 TO 25 KTS WITH GUSTS NEAR 30 KTS FOR TODAY AND
THEN DECREASE A BIT AFTER SUNSET TONIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...FREEZING RAIN ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR NDZ038-
039-049-052-053.
MN...FREEZING RAIN ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR MNZ002-
003-006-009-015>017-022>024-027>032-040.
&&
$$
UPDATE...VOELKER
SHORT TERM...JR
LONG TERM...JR/HOPPES
AVIATION...JR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
904 AM CST MON DEC 15 2014
.UPDATE...
ISSUED AT 856 AM CST MON DEC 15 2014
MAIN CHANGE FOR MORNING UPDATE WAS TO EXTEND THE FREEZING RAIN
ADVISORY THROUGH THE REMAINDER OF THE MORNING. VARIOUS LOCATIONS
THROUGHOUT THE AREA CONTINUE TO REPORT A LIGHT DRIZZLE AFTER A
PERIOD OF LIGHT SNOW...WHICH IS SUPPORTED BY LATEST RAP SOUNDING
ANALYSIS WHICH CONTINUES TO INDICATE DRYING AT MID-LEVELS WITH A
MOIST LOW LEVEL. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 634 AM CST MON DEC 15 2014
LATEST RAPID UPDATE CYCLE FORECAST SOUNDINGS SHOW LOW LEVEL
SUPER COOLED WATER WITH DRY AIR ABOVE ACROSS THE WEST AND CENTRAL.
SEEING BEACH AWOS WITH LIGHT FREEZING RAIN AS WELL AS STANLEY AND
MANDAN. WILL NEED THE ADVISORY THROUGH 9 AM.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CST MON DEC 15 2014
LIGHT FREEZING RAIN/DRIZZLE IS THE MAIN HIGHLIGHT IN THIS PERIOD.
AFTER COLLABORATING WITH NEIGHBORING OFFICES HAVE OPTED TO EXTEND
THE ONGOING FREEZING RAIN ADVISORY UNTIL 15Z MONDAY FOR SOUTHWESTERN
AND MOST OF CENTRAL NORTH DAKOTA.
NAM/GFS...AND ESPECIALLY THE NEAR TERM RAP13 BUFKIT SOUNDINGS
MAINTAIN A SATURATED LOW LEVEL SUBFREEZING LAYER WITH AMPLE LIFT
PER OMEGA FIELD TO KEEP A MENTION OF FREEZING PRECIPITATION GOING.
SOUNDINGS SHOW A TEMPORARY MOIST LAYER IN THE -8C TO -20C LAYER...BUT
THIS IS FORECAST TO WANE AND BECOME DRIER THROUGH MID MORNING.
THUS WITH AN ABSENT OF ICE CRYSTALS FORMING ALOFT...ATTENTION
TURNS BACK TO THE SATURATED LOWER LEVELS WHERE TEMPERATURES RANGE
BETWEEN -5C AND -10C. EXPECT MOSTLY SUPERCOOLED WATER DROPLETS
WITH LIGHT FREEZING RAIN/DRIZZLE. HOWEVER...SOME ICE CRYSTAL
FORMATION MAY OCCUR NEAR -10C SO LIGHT SNOW MAY ALSO DEVELOP AT
TIMES. BOTTOM LINE IS WITH LOW LEVEL LIFT BEING MAINTAINED IN THIS
SATURATED LAYER...THE THREAT FOR ADDITIONAL FREEZING PRECIPITATION
WARRANTS AN EXTENSION THROUGH MID MORNING. IMPACT TO TRAVEL
REMAINS HAZARDOUS WITH SEVERAL NO TRAVEL ADVISORIES ISSUED
OVERNIGHT DUE TO ICY ROADS. BOWMAN RADAR AND SURFACE OBSERVATIONS
SHOW AN AREA OF SNOW MOVING SOUTH...WITH BEACH TRANSITIONING FROM
SNOW BACK TO FREEZING PRECIPITATION. ANY SNOWFALL ACCUMULATIONS
WILL REMAIN LIGHT...LESS THAN A QUARTER INCH...BUT WILL ADD TO ICY
CONDITIONS AND HAZARDOUS TRAVEL.
NORTHERN UPPER TROUGH PER LATEST WATER VAPOR IMAGERY ACROSS SOUTHERN
SASKATCHEWAN AND MANITOBA WILL SWING THROUGH NORTH DAKOTA TODAY.
COLD AIR ADVECTION WITH BRISK NORTHWEST WINDS OF 15 TO 30 MPH
CAN BE EXPECTED TODAY. EXTENSIVE STRATUS DECK ACROSS EASTERN
ALBERTA...THROUGH SASKATCHEWAN AND MANITOBA WILL PUSH SOUTHEAST.
HAVE INCREASED SKY GRIDS TO REFLECT CLOUDY CONDITIONS TODAY INTO
TONIGHT. IN DOING SO OVERNIGHT MINIMUMS WERE INCREASED. THE DAY
SHIFT CAN RE-EVALUATE THIS LATER TODAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 313 AM CST MON DEC 15 2014
.LONG TERM...TUESDAY THROUGH SUNDAY...
THE EXTENDED WILL FEATURE AN H500 SEPARATION OF FLOW WITH A NORTHERN
AND SOUTHERN STREAM LEAVING THE NORTHERN PLAINS IN A RATHER WEAK
FLOW ALOFT. THIS BLOCKING PATTERN WILL CUT OFF THE MOISTURE TO THE
SOUTH AND LEAVE JET STREAM ENERGY TOO FAR NORTH. WITH LITTLE IN
SHORT WAVE ENERGY TO BRING PRECIPITATION CHANCES THE EXTENDED PERIOD
IS LEFT DRY. AGAIN...CONCERNS ABOUT WEAK FLOW ALOFT AND LACK UP
UPPER LEVEL VENTILATION AND A STAGNANT AIR PATTERN THERE WILL BE
CONCERNS ABOUT LOW LEVEL STRATUS AND FOG. BEST OPTION HERE IS TI
DEAL WITH THESE FEATURES IF AND WHEN THEY DEVELOP. FOR NOW BEGAN THE
EXTENDED ON TUESDAY WITH RESIDUAL CLOUDINESS THROUGH MOST OF THE DAY
AS THE CIRCULATION AROUND AN UPPER LOW MAINTAINS A COOL AND MOIST
FLOW OVER THE STATE. AFTER TUESDAY THE FLOW ALOFT BECOMES WEAK AS
THE GREAT LAKES LOW MOVES EAST AND THE NORTHERN PLAINS END UP
BETWEEN THE NORTHERN AND SOUTHERN STREAM FLOWS. A WEAK IMPULSE IN
THE SOUTHERN STREAM WILL BRUSH ACROSS THE CENTRAL PLAINS WEDNESDAY
THROUGH FRIDAY. THIS LEAVE THE NORTHERN PLAINS DRY WITH A SLOW
MODERATING TREND TO TEMPERATURES BY THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 634 AM CST MON DEC 15 2014
LARGE SWATH OF MVFR/IFR CIGS WILL CONTINUE THROUGH THE TAF PERIOD.
OCCASIONAL LIGHT FREEZING DRIZZLE AND/OR LIGHT SNOW CAN BE EXPECTED
AT KBIS/KDIK THROUGH MID MORNING WITH ANY ACCUMULATIONS REMAINING
VERY LIGHT. BRISK NORTHERLY TO NORTHWEST WINDS OF 15KT TO 30KT MPH
WILL ALSO OCCUR AT THE TERMINALS THROUGH 00Z...HOWEVER KJMS WILL
CONTINUE WITH GUSTY WINDS THROUGH 12Z TUESDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR
NDZ011-012-017>023-025-031>037-040>048-050-051.
&&
$$
UPDATE...JJS
SHORT TERM...KS
LONG TERM...WAA
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
646 AM CST MON DEC 15 2014
.UPDATE...
ISSUED AT 645 AM CST MON DEC 15 2014
MOST OF THE FREEZING DRIZZLE HAS MOVED SOUTH AND EAST OUT OF THE
GFK AREA...BUT WITH RECENT WET CONDITIONS AND COLD TEMPS
CONDITIONS CONTINUE TO BE SLICK. IN ADDITION...MORE RETURNS ARE
STARTING TO DEVELOP OVER THE SOUTHERN FORECAST AREA AND SHOULD
CONTINUE OVER THE NEXT FEW HOURS. THUS WILL KEEP THE ADVISORY
GOING FOR NOW.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 402 AM CST MON DEC 15 2014
MAIN HEADACHE IS FREEZING DRIZZLE AND HOW LONG IT WILL LAST TODAY.
THE SPLIT FLOW ALOFT CONTINUES WITH THE NORTHERN BRANCH SHORTWAVE
DIGGING DOWN THROUGH SOUTHERN CANADA AND THE SOUTHERN CUT OFF LOW
MOVING THROUGH KANSAS ON ITS WAY TO IOWA. THE SFC LOW HAS MOVED TO
THE EAST OF THE CWA AND MOST SITES HAVE SEEN A SHIFT TO
NORTHWESTERLY WINDS AND GOOD COLD AIR ADVECTION. A FEW SPOTS IN
THE EASTERN TIER ARE HANGING ABOVE FREEZING BUT THE REST HAVE
FALLEN BELOW. LOW LEVEL MOISTURE CONTINUES TO BE ABUNDANT EVEN
BEHIND THE COLD FRONT AND MODEL SOUNDINGS INDICATE A DRY LAYER
ALOFT WHERE TEMPS WOULD BE COLD ENOUGH FOR ICE GROWTH...SO MOST OF
OUR PRECIP WILL BE SUPERCOOLED WATER. THE RAP AND NAM BOTH HAVE
THE LOW LEVEL OMEGA IN THAT SATURATED LAYER CONTINUING TO SHOW
SOME RISING MOTION. WILL EXTEND THE FREEZING RAIN ADVISORY UNTIL
15Z AND EXTEND IT EAST AS TEMPS HAVE BEEN FALLING AND VIS HAVE
BEEN RISING WHERE OUR DENSE FOG HEADLINE WAS OVER THE EASTERN
COUNTIES.
THE SOUTHERN BRANCH SHORTWAVE WILL STAY MAINLY TO OUR SOUTHEAST
TODAY...BUT KEPT SOME LOW POPS TO BLEND IN AS THE SYSTEM PASSES
BY. TONIGHT...THE NORTHERN BRANCH SHORTWAVE WILL DIG DOWN INTO
NORTHEASTERN MN AND SFC HIGH PRESSURE WILL BUILD INTO THE WESTERN
PLAINS. SAT LOOP SHOWS FAIRLY CONSISTENT CLOUDS WELL TO OUR NORTH
AND WEST UNTIL ON THE WEST SIDE OF THE SFC RIDGE CURRENTLY ALONG
THE SASKATCHEWAN/ALBERTA BORDER. TIME HEIGHTS CONTINUE TO SHOW A
LOT OF RH AT LOW LEVELS SO THINK THAT CLOUDS WILL HANG ON LONGER
THAN EXPECTED. BUMPED UP CLOUDS AND RAISED LOWS A FEW DEGREES
ACCORDINGLY FOR TONIGHT.
TUESDAY...THE SFC HIGH PRESSURE WILL MOVE EASTWARD INTO THE
CWA...BUT THE AXIS WILL STILL BE WEST OF MOST OF OUR COUNITES SO
KEPT CLOUDS HIGHER A BIT LONGER ALTHOUGH NOT COMPLETELY SOCKED IN.
EVEN WITH A BIT OF SUN COLD AIR ADVECTION WILL KEEP THE TEMPS IN
THE TEENS FOR TUESDAY AND WITH BREEZY NORTHWEST WINDS IT WILL FEEL
RATHER RAW.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 AM CST MON DEC 15 2014
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...SPLIT FLOW CONTINUES WITH
SFC HIGH PRESSURE CONTINUING OVER THE REGION. TEMPS WILL REMAIN
COLD EVEN AS CLOUDS START TO DECREASE. LOWS WILL BE IN THE SINGLE
DIGITS AND HIGHS IN THE TEENS.
THURSDAY THROUGH SUNDAY...LONG WAVE TROUGH OFF THE WEST COAST OF
CANADA REMAINS THROUGH DAY 5 THEN RETROGRADES/RE-ESTABLISH
FARTHER WEST THROUGH THE END OF THE PERIOD. SPLIT FLOW CONTINUES
ACROSS NORTH AMERICA THROUGH THE PERIOD. FLOW ALOFT REMAINS
RELATIVELY PROGRESSIVE THROUGH THE PERIOD. MUCH ABOVE NORMAL
HEIGHTS REMAIN OVER HUDSON BAY AND SOUTHERN CANADA.
GFS AND ECMWF WERE SIMILAR AT THE BEGINNING OF THE PERIOD. HOWEVER
THE GFS WANT TO DEVELOP A STRONGER TROUGH OVER CENTRAL
CANADA/NORTHERN PLAINS ON FRI AND SAT WHICH IS OUT OF PHASE WITH THE
ECMWF FOR THE REST OF THE PERIOD. WILL PREFER THE ECMWF.
LITTLE OR NO PRECIP THROUGH THE EXTENDED FORECAST. LITTLE CHANGE TO
TEMPS ON THU AND FRI. HIGH TEMPS DECREASED A DEGREE OR TWO FOR SAT
AND SUN MOST PLACES COMPARED TO THE PREVIOUS FORECAST PACKAGE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 645 AM CST MON DEC 15 2014
IFR CONDITIONS CONTINUE AT MOST TAF SITES WITH SOME MVFR AT KDVL.
KBJI AND KFAR CONTINUE TO HAVE SOME RESTRICTIONS TO VISIBILITY
WITH MIST AND FREEZING RAIN...BUT GENERALLY IN THE 3-5SM RANGE.
VIS WILL CONTINUE TO IMPROVE AND CIGS SHOULD SLOWLY RISE TO MVFR
BY LATER THIS AFTERNOON IN MOST AREAS. NORTHWEST WIND WILL BE
SUSTAINED AT 20 TO 25 KTS WITH GUSTS NEAR 30 KTS FOR TODAY AND
THEN DECREASE A BIT AFTER SUNSET TONIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...FREEZING RAIN ADVISORY UNTIL 9 AM CST THIS MORNING FOR NDZ016-
027-029-030-038-039-049-052-053.
MN...FREEZING RAIN ADVISORY UNTIL 9 AM CST THIS MORNING FOR
MNZ001>009-013>017-022>024-027>032-040.
&&
$$
UPDATE...JR
SHORT TERM...JR
LONG TERM...JR/HOPPES
AVIATION...JR
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
544 AM CST MON DEC 15 2014
.AVIATION...
FOR THE 12Z TAFS...THE PRIMARY FORECAST CONCERN IS CROSSWIND
CONDITIONS ACROSS DFW AREA TAF SITES TODAY.
FOR THE TAFS...CLOSELY FOLLOWED LAMP AND RAP GUIDANCE FOR WIND
DIRECTION AND INTENSITY THROUGHOUT THE DAY TODAY. WINDS WILL
MAINTAIN A STRONG WESTERLY COMPONENT THROUGHOUT THE DAY...STARTING
OFF JUST SOUTH OF DUE WEST...VEERING TO JUST NORTH OF DUE WEST BY
THE MID-MORNING HOURS. HAVE THE CURRENT FORECAST INTENSITY OF
THESE WESTERLY WINDS HOLDING JUST BELOW 20 KTS THIS
MORNING...INTRODUCING SOME GUSTS TO 25 KTS DURING THE PEAK HEATING
HOURS OF THE DAY. THE CROSSWIND IMPACT DIAGRAM INDICATES SOME LOW
TO MODERATE CROSSWIND IMPACTS WITH THE CURRENT FORECAST...REDUCING
THE ACCEPTANCE RATE AT DFW AIRPORT.
THE PRIMARY THING TO WATCH THIS MORNING WILL BE HOW QUICKLY WE
HEAT UP AND MIX DOWN SOME OF THE STRONGER WINDS ALOFT TO THE
SURFACE. AREA VAD WIND PROFILES AND THE EARLY DATA COMING IN FROM
THE FWD RAOB INDICATE WESTERLY WINDS OF 35 TO 40 KTS IN THE 925 TO
850 MB LAYER. MODELS INDICATE THAT WINDS IN THIS LAYER WILL
DIMINISH BY LATE THIS MORNING...WHEN WE ARE LIKELY TO GET WARM
ENOUGH TO MIX INTO THIS LAYER. AS LONG AS THESE WINDS ALOFT
DIMINISH AS FORECAST...THE CURRENT FORECAST IS IN GOOD SHAPE. IF
WE HEAT UP QUICKER THAN EXPECTED...OR IF MODELS ARE SIMPLY TOO
AGGRESSIVE IN DIMINISHING THE STRENGTH OF WINDS ALOFT...WE MAY SEE
SOME GUSTS TO 25-27 KTS LATE THIS MORNING. WE WILL BE KEEPING A
CLOSE EYE ON AIRCRAFT RAOBS THIS MORNING AND WILL ADJUST TAFS ASAP
IF IT LOOKS LIKE THE CURRENT FORECAST IS UNDER FORECASTING THE
STRENGTH OF CROSSWINDS.
OTHERWISE...WITH DRY AIR IN PLACE...VFR CONDITIONS ARE EXPECTED
OVER THE NEXT 24-36 HOURS.
CAVANAUGH
&&
.PREV DISCUSSION... /ISSUED 354 AM CST MON DEC 15 2014/
UPPER LOW OVER CENTRAL KANSAS IS QUITE EVIDENT IN UPPER AIR
OBSERVATIONS AND SATELLITE DATA. THE LAST GASP OF STORMS FOR NORTH
AND CENTRAL TEXAS CONTINUES TO MARCH EASTWARD AND SHOULD CLEAR OUR
AREA BY MID MORNING OR SO. AT 08Z...THE LINE WAS LOCATED FROM JUST
EAST OF PARIS...TO CEDAR CREEK RESERVOIR...TO WACO. BEHIND THIS
LINE...DRIER AIR WILL FILTER IN AT THE SURFACE AND ALOFT...LEAVING
SUNSHINE AND WARM TEMPERATURES.
AS THE UPPER LOW MOVES NORTHEAST...THE COOLER AIR IN THE CENTRAL
PLAINS WILL FINALLY HAVE A CHANCE TO MOVE INTO NORTH TEXAS. THE
COOLER AIR WILL TAKE ANOTHER DAY TO MOVE SOUTH...LEAVING MOST OF
US WITH HIGHS IN THE 60S TODAY. TEMPERATURES DROP A BIT ON TUESDAY
THANKS TO THE COOLER AIR FILTERING IN...AND THANKS TO DRIER AIR
ALLOWING OVERNIGHT LOWS TO DROP TO MID DECEMBER NORMALS. THE NEXT
SHOT OF RAINFALL COMES BACK ON WEDNESDAY AS THE NEXT WAVE MOVES IN
FROM THE WEST AND ISENTROPIC LIFT INCREASES FROM THE SOUTH. RAIN
CHANCES REMAIN ON THURSDAY.
AFTER THURSDAY...THE WATERS ARE MUDDY. THE GFS AND ECMWF ARE
CONSISTENT WITH EACH OTHER THROUGH THURSDAY BEFORE DIVERGING
WIDELY FOR FRIDAY AND SATURDAY. BOTH MODELS AGREE IN A SHORT WAVE
TROUGH SOMEWHERE IN THE SOUTH CENTRAL PLAINS ON FRIDAY AND
SATURDAY. BOTH SOLUTIONS HAVE THE SHORT WAVE TROUGH DEEPENING INTO
A CLOSED LOW ON SATURDAY AS THE SYSTEM MOVES NORTHEAST.
THE FINER DETAILS OF THESE FEATURES WILL BE CRITICAL FOR OUR
WEATHER. BY 12Z FRIDAY...THE EURO DEPICTS THE STORM WILL BE CENTERED
SOMEWHERE NEAR DEL RIO WHILE THE GFS HAS THE STORM NEAR CHILDRESS.
BY 00Z SATURDAY...THE EURO MOVES THE UPPER LOW TO NEAR LUFKIN...AND
THE GFS MOVES THE STORM TO NEAR MUSKOGEE.
BEING FOUR TO FIVE DAYS AWAY... AND SEEING THE SYSTEM OFF OF THE ALEUTIAN
ISLANDS EARLY THIS MORNING...DO NOT WANT TO GET TOO CUTE WITH THE
DETAILS. HAVE LEANED CLOSER TO THE ECMWF SOLUTION AND AM UNDERCUTTING
GUIDANCE BY SEVERAL DEGREES IN THE EXTENDED PERIODS. BOTH THE ECMWF
AND GFS ENSEMBLES SUGGEST LOWER THAN NORMAL 500MB HEIGHTS WOULD BE
FARTHER SOUTH. DESPITE THE BIG DIFFERENCE IN THE FEATURES...EACH
SOLUTION HAS RELATIVELY HIGH POPS FOR THIS TIME FRAME...SO COLD
RAIN LOOKS QUITE POSSIBLE FOR FRIDAY. WE REMAIN IN A PROGRESSIVE
PATTERN...SO THIS FEATURE QUICKLY MOVES EAST LEAVING THE REMAINDER
OF NEXT WEEKEND DRY.
FOX
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 65 38 53 40 50 / 0 0 5 5 50
WACO, TX 68 39 56 41 51 / 0 0 5 10 50
PARIS, TX 63 37 51 35 47 / 5 5 5 10 50
DENTON, TX 63 36 52 36 47 / 0 0 5 5 50
MCKINNEY, TX 63 36 52 36 49 / 0 0 5 5 50
DALLAS, TX 65 39 53 40 50 / 0 0 5 5 50
TERRELL, TX 65 39 52 38 50 / 5 0 5 5 50
CORSICANA, TX 67 40 56 40 52 / 5 0 5 5 50
TEMPLE, TX 68 39 58 43 52 / 0 0 5 10 50
MINERAL WELLS, TX 63 35 54 39 48 / 0 0 5 5 50
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
254 PM EST MON DEC 15 2014
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 355 AM EST MON DEC 15 2014
A LOW PRESSURE SYSTEM WILL BRING RAIN SHOWERS TO CENTRAL INDIANA
EARLY THIS WEEK. AFTER A DRY PERIOD UNDER HIGH PRESSURE
MIDWEEK...ANOTHER LOW PRESSURE SYSTEM WILL BRING CHANCES FOR RAIN OR
SNOW TO THE AREA THIS WEEKEND.
ABOVE AVERAGE TEMPERATURES ARE EXPECTED THROUGH TUESDAY. AFTER
THAT...SLIGHTLY BELOW NORMAL TEMPERATURES WILL TAKE OVER THROUGH THE
WEEKEND.
&&
.NEAR TERM /TODAY AND TONIGHT/...
ISSUED AT 959 AM EST MON DEC 15 2014
RAIN CONTINUES TO MARCH EAST TOWARD CENTRAL INDIANA FROM ILLINOIS
THIS MORNING. THERE HAS BEEN SOME WEAKENING TO THE RAIN...BUT NOT AS
MUCH AS SOME OF THE MODELS HAVE BEEN SUGGESTING. THUS ONLY HAD TO
MAKE SOME MINOR ADJUSTMENTS TO HOURLY POPS.
BASED ON LATEST TRENDS AND MODEL DATA...BUMPED DOWN TEMPERATURES A
BIT FOR THIS AFTERNOON AND ADJUSTED TEMPERATURES THIS EVENING.
VISIBILITY HAS IMPROVED TO 3 MILES OR ABOVE MOST AREAS...SO REMOVED
FOG AS NEEDED.
PREVIOUS DISCUSSION FOLLOWS...
MAIN FOCUS FOR THE SHORT TERM WILL BE ON TIMING OF RAIN SHOWERS TO
THE AREA ALONG WITH TEMPERATURES.
MODELS IN GOOD AGREEMENT THAT A STACKED LOW PRESSURE SYSTEM OVER
SOUTH CENTRAL KANSAS EARLY THIS MORNING WILL LIFT NORTHEAST TO
SOUTHEASTERN IOWA BY 00Z THIS EVENING PROVIDING UPPER LEVEL
DIVERGENCE OVER CENTRAL INDIANA AS WELL AS DEEPENING MOISTURE.
NATIONAL RADAR LOOP WAS SHOWING AN AREA OF SHOWERS ACROSS CENTRAL
MISSOURI AND WESTERN ARKANSAS AHEAD OF THIS SYSTEM AND WITHIN
NOCTURNAL LOW LEVEL JET. THIS JET WILL MIGRATE EASTWARD AND WEAKEN A
BIT TO 35 TO 40 KNOTS WITH THE NOSE ACROSS SOUTH CENTRAL INDIANA
LATE THIS AFTERNOON. NAM12 AND HRRR RAPID REFRESH REFLECTIVITY PROGS
SUGGEST MORE OR LESS SOLID AREA OF SHOWERS SHOULD MOVE INTO OUR
SOUTHWESTERN COUNTIES AFTER 10 AM AND APPROACH INTERSTATE 65 BY 4 PM
BEFORE MOVING INTO OHIO AFTER 00Z THIS EVENING. THIS TIMING ALSO
MATCHES UP PRETTY GOOD WITH SIMILAR 00Z MODEL QPF FIELDS.
TONIGHT...TRIPLE POINT OF ASSOCIATED FRONTAL SYSTEM SHOULD LIFT
NORTHEAST ACROSS OUR NORTHERN COUNTIES RESULTING IN ANOTHER MORE
WIDESPREAD AREA OF SHOWERS LIFTING NORTHEAST ACROSS THE AREA. RAISED
QPF A BIT FROM THE 00Z SUPERBLEND AND 06Z HPC NUMBERS WITH STORM
TOTAL PRECIPITATION OF HALF AN INCH POSSIBLE. INSTABILITY PROGS
BRING SOME INSTABILITY UP CLOSE TO OUR SOUTHERN BORDER THIS
AFTERNOON AND EVENING...BUT NOT ENOUGH TO INCLUDE THUNDER AT THIS
POINT AFTER LOOKING AT LIGHTNING STRIKE TRENDS.
WENT ON THE COOL SIDE OF MOS TODAY WITH THE CLOUDS HANGING AROUND
AND RAIN MOVING IN.
&&
.SHORT TERM.../TUESDAY THROUGH WEDNESDAY NIGHT/
ISSUED AT 355 AM EST MON DEC 15 2014
SHORT TERM FOCUS IS ON POPS AS WELL AS TEMPERATURES AS A COLD FRONT
ROLLS THROUGH THE AREA LATE TUESDAY AND TUESDAY NIGHT. MODELS
CONTINUE TO AGREE THAT THE STACKED LOW WILL LIFT NORTHEAST ACROSS
SOUTHERN LOWER MICHIGAN ON TUESDAY AND A COLD FRONT WILL SLIDE
SOUTHEAST ACROSS THE AREA TUESDAY EVENING. MEANWHILE...SUFFICIENT
MOISTURE WILL LINGER THROUGH TUESDAY NIGHT WITH THE EXCEPTION OF
SOME DRYING FROM THE SOUTHWEST. THUS...WILL KEEP DECENT POPS MAINLY
NORTHEAST ON TUESDAY CLOSER TO THE BETTER FORCING AND DEEPER
MOISTURE. THEN...WILL ONLY HANG ON TO SMALL EVENING POPS NORTHEAST
TUESDAY NIGHT AS THE SYSTEM PULLS AWAY AND BECOMES ABSORBED IN AN
UPPER MIDWEST SYSTEM.
COULD SEE SOME BREAKS IN THE CLOUDS ON WEDNESDAY AND WEDNESDAY
NIGHT. HOWEVER...WILL NOT CLEAR THINGS COMPLETELY OUT AS MODEL
SOUNDINGS SHOW ANOTHER STRONG INVERSION.
WITH CLOUDS EXPECTED TO HANG AROUND ON WEDNESDAY WENT WITH THE
COOLER 00Z NAM MOS...OTHERWISE MOS TEMPERATURES CLOSE ENOUGH FOR A
BLEND.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 254 PM EST MON DEC 15 2014
EXTENDED FOCUS REMAINS ON POTENTIAL IMPACTS FROM A STORM SYSTEM
TRACKING FROM THE NORTHERN GULF TO OFF THE CAROLINA COAST FRIDAY-
SATURDAY. 12Z MODEL SUITE HAS NOT HELPED CLARIFY THE BIG PICTURE
WITH GREATER VARIANCE NOTED IN HANDLING OF PHASING ALOFT AND
SUBSEQUENTLY THE TRACK AND INTENSITY OF THE SURFACE WAVE.
OP GFS THIS AFTERNOON APPEARS TO BE A MAJOR OUTLIER...WITH ITS
HANDLING OF THE DEEP UPPER LOW OFF THE CANADIAN MARITIMES LIKELY
TO BE INFLUENCING ITS SOLUTION. THE MODEL SHIFTS THIS FEATURE
EASTWARD FASTER THAN OTHER MODELS ON FRIDAY...AND APPEARS TO
UNDERDEVELOP ENERGY ALOFT TRACKING WITH THE POLAR JET ACROSS THE
NORTHERN PLAINS. AS A RESULT...THE NORTHERN JET ENERGY NEVER
REALLY INTERACTS AND PHASES WITH THE UPPER WAVE RIDING ALONG THE
SUBTROPICAL JET LEADING TO A FLATTENED AND MUCH WEAKER SOLUTION.
THIS GOES AGAINST THE MAJORITY OF THE GFS ENSEMBLE MEMBERS...THE
GGEM AND THE ECMWF WHICH ALL MAINTAIN A STRONGER AND MORE PHASED
SOLUTION. WITH THAT BEING SAID...BULK OF THE MODEL CONSENSUS HAS
SHIFTED BACK TO A MORE SUPPRESSED SURFACE LOW TRACK KEEPING MOST
OF THE PRECIPITATION CONFINED TO FAR SOUTHERN PARTS OF THE
FORECAST AREA AND POINTS SOUTH.
CONSIDERING ALL OF THE MODEL VARIANCE HIGHLIGHTED ABOVE HAVE
TRENDED POPS DOWN A BIT OVER THE FORECAST AREA FRIDAY NIGHT AND
SATURDAY...BUT FEEL THAT CHANCE POPS REMAIN WARRANTED OVER THE
ENTIRE FORECAST AREA. DEGREE OF PHASING ALOFT REMAINS A CRITICAL
ELEMENT IN DETERMINING HOW FAR NORTH THE LOW AND PRECIP SHIELD
COMES AND MODELS DO NOT SEEM TO HAVE A SOLID ENOUGH HANDLE ON THIS
AT THIS EARLY STAGE. QUITE POSSIBLE THAT FUTURE MODEL RUNS BRING
GREATER IMPACTS BACK TO THE FORECAST AREA...ONE OF THE MAIN
REASONS REMOVING POPS WOULD BE PREMATURE. REGARDLESS OF TRACK...
LOW LEVEL THERMAL ANALYSIS IS MORE SUPPORTIVE OF SNOW AS THE
PREDOMINANT PRECIP TYPE AND HAVE REMOVED ANY MENTION OF RAIN/SNOW
MIX. SUSPECT THE MODEL VARIANCE WILL CONTINUE FOR THE NEXT COUPLE
DAYS BEFORE FOCUSING IN ON A MORE CONSENSUS TRACK. THE BIGGEST
TAKEAWAY REMAINS THAT THIS STORM MAY PRODUCE WINTRY IMPACTS OVER
PARTS OR ALL OF THE FORECAST AREA FRIDAY NIGHT AND SATURDAY. STAY
TUNED.
DRIER WEATHER RETURNS FOR SUNDAY AND MONDAY WITH THE RETURN OF
HIGH PRESSURE. UNDERCUT SUPERBLEND GUIDANCE AGAIN FOR HIGHS
THROUGH THE PERIOD. EXPECT HIGHS PRIMARILY IN THE LOWER/MIDDLE 30S
THROUGH THE EXTENDED.
&&
.AVIATION /DISCUSSION FOR 151800Z TAF ISSUANCE/...
ISSUED AT 1233 PM EST MON DEC 15 2014
SUBTLE IMPROVEMENTS TO MVFR CEILINGS DURING THE AFTERNOON...WITH
IFR CONDITIONS RETURNING WITH RAIN TONIGHT AND TUESDAY.
SLIGHTLY DRIER AIR HAS BEEN PULLED NORTH INTO THE OHIO VALLEY
AHEAD OF THE APPROACHING AREA OF RAIN...AND THAT HAS ENABLED
CEILINGS TO LIFT INTO THE MVFR CATEGORY AT BOTH KBMG AND KIND
EARLY THIS AFTERNOON. BASED ON CURRENT SATELLITE IMAGERY...QUITE
POSSIBLE THAT BOTH OF THESE SITES SEE BRIEF BREAKS IN THE STRATUS
AND POSSIBLE CEILINGS LIFTING TO 1500-2500FT FOR A FEW HOURS.
INITIAL SURGE OF PRECIP WILL IMPACT THE TERMINALS THRU 21Z WITH
MORE WIDESPREAD LIGHT RAINFALL FOLLOWING THEREAFTER. SOUTHEAST
WINDS TO 10 TO 15KTS ARE POSSIBLE WITH A SPORADIC HIGHER GUST
THROUGH THE AFTERNOON.
ONCE THE WIDESPREAD RAIN ARRIVES...ANY GAINS IN CEILING RISES
WILL BE LOST AS MODEL SOUNDINGS AND 950MB RH PROGS SHOW SATURATION
OF THE NEAR SURFACE LAYER TAKING PLACE. EXPECT CEILINGS TO SETTLE
BACK INTO THE IFR CATEGORY BY EARLY EVENING AND REMAIN THERE
THROUGH THE REST OF THE FORECAST PERIOD. CURRENT HI-RES MODEL
GUIDANCE INDICATES THERE SHOULD BE A 4-5 HOUR WINDOW WITH LITTLE
IF ANY RAIN AT ALL SITES BUT KLAF OVERNIGHT AS A DRY SLOT
TRANSITIONS ACROSS THE FORECAST AREA. AS LOW PRESSURE PASSES BY TO
THE NORTH TUESDAY MORNING...MOISTURE WILL BE DRAWN BACK INTO THE
REGION FROM THE NORTHWEST WITH A RESUMPTION OF LIGHT RAIN
SHOWERS. MAY ACTUALLY SEE CEILINGS AND VISIBILITIES WORSEN AFTER
DAYBREAK. WINDS WILL VEER FROM SOUTHEAST THIS EVENING TO SOUTHWEST
BY TUESDAY MORNING AND BECOME GUSTY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK/50
SHORT TERM...MK
LONG TERM....RYAN
AVIATION...RYAN
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1233 PM EST MON DEC 15 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 355 AM EST MON DEC 15 2014
A LOW PRESSURE SYSTEM WILL BRING RAIN SHOWERS TO CENTRAL INDIANA
EARLY THIS WEEK. AFTER A DRY PERIOD UNDER HIGH PRESSURE
MIDWEEK...ANOTHER LOW PRESSURE SYSTEM WILL BRING CHANCES FOR RAIN OR
SNOW TO THE AREA THIS WEEKEND.
ABOVE AVERAGE TEMPERATURES ARE EXPECTED THROUGH TUESDAY. AFTER
THAT...SLIGHTLY BELOW NORMAL TEMPERATURES WILL TAKE OVER THROUGH THE
WEEKEND.
&&
.NEAR TERM /TODAY AND TONIGHT/...
ISSUED AT 959 AM EST MON DEC 15 2014
RAIN CONTINUES TO MARCH EAST TOWARD CENTRAL INDIANA FROM ILLINOIS
THIS MORNING. THERE HAS BEEN SOME WEAKENING TO THE RAIN...BUT NOT AS
MUCH AS SOME OF THE MODELS HAVE BEEN SUGGESTING. THUS ONLY HAD TO
MAKE SOME MINOR ADJUSTMENTS TO HOURLY POPS.
BASED ON LATEST TRENDS AND MODEL DATA...BUMPED DOWN TEMPERATURES A
BIT FOR THIS AFTERNOON AND ADJUSTED TEMPERATURES THIS EVENING.
VISIBILITY HAS IMPROVED TO 3 MILES OR ABOVE MOST AREAS...SO REMOVED
FOG AS NEEDED.
PREVIOUS DISCUSSION FOLLOWS...
MAIN FOCUS FOR THE SHORT TERM WILL BE ON TIMING OF RAIN SHOWERS TO
THE AREA ALONG WITH TEMPERATURES.
MODELS IN GOOD AGREEMENT THAT A STACKED LOW PRESSURE SYSTEM OVER
SOUTH CENTRAL KANSAS EARLY THIS MORNING WILL LIFT NORTHEAST TO
SOUTHEASTERN IOWA BY 00Z THIS EVENING PROVIDING UPPER LEVEL
DIVERGENCE OVER CENTRAL INDIANA AS WELL AS DEEPENING MOISTURE.
NATIONAL RADAR LOOP WAS SHOWING AN AREA OF SHOWERS ACROSS CENTRAL
MISSOURI AND WESTERN ARKANSAS AHEAD OF THIS SYSTEM AND WITHIN
NOCTURNAL LOW LEVEL JET. THIS JET WILL MIGRATE EASTWARD AND WEAKEN A
BIT TO 35 TO 40 KNOTS WITH THE NOSE ACROSS SOUTH CENTRAL INDIANA
LATE THIS AFTERNOON. NAM12 AND HRRR RAPID REFRESH REFLECTIVITY PROGS
SUGGEST MORE OR LESS SOLID AREA OF SHOWERS SHOULD MOVE INTO OUR
SOUTHWESTERN COUNTIES AFTER 10 AM AND APPROACH INTERSTATE 65 BY 4 PM
BEFORE MOVING INTO OHIO AFTER 00Z THIS EVENING. THIS TIMING ALSO
MATCHES UP PRETTY GOOD WITH SIMILAR 00Z MODEL QPF FIELDS.
TONIGHT...TRIPLE POINT OF ASSOCIATED FRONTAL SYSTEM SHOULD LIFT
NORTHEAST ACROSS OUR NORTHERN COUNTIES RESULTING IN ANOTHER MORE
WIDESPREAD AREA OF SHOWERS LIFTING NORTHEAST ACROSS THE AREA. RAISED
QPF A BIT FROM THE 00Z SUPERBLEND AND 06Z HPC NUMBERS WITH STORM
TOTAL PRECIPITATION OF HALF AN INCH POSSIBLE. INSTABILITY PROGS
BRING SOME INSTABILITY UP CLOSE TO OUR SOUTHERN BORDER THIS
AFTERNOON AND EVENING...BUT NOT ENOUGH TO INCLUDE THUNDER AT THIS
POINT AFTER LOOKING AT LIGHTNING STRIKE TRENDS.
WENT ON THE COOL SIDE OF MOS TODAY WITH THE CLOUDS HANGING AROUND
AND RAIN MOVING IN.
&&
.SHORT TERM.../TUESDAY THROUGH WEDNESDAY NIGHT/
ISSUED AT 355 AM EST MON DEC 15 2014
SHORT TERM FOCUS IS ON POPS AS WELL AS TEMPERATURES AS A COLD FRONT
ROLLS THROUGH THE AREA LATE TUESDAY AND TUESDAY NIGHT. MODELS
CONTINUE TO AGREE THAT THE STACKED LOW WILL LIFT NORTHEAST ACROSS
SOUTHERN LOWER MICHIGAN ON TUESDAY AND A COLD FRONT WILL SLIDE
SOUTHEAST ACROSS THE AREA TUESDAY EVENING. MEANWHILE...SUFFICIENT
MOISTURE WILL LINGER THROUGH TUESDAY NIGHT WITH THE EXCEPTION OF
SOME DRYING FROM THE SOUTHWEST. THUS...WILL KEEP DECENT POPS MAINLY
NORTHEAST ON TUESDAY CLOSER TO THE BETTER FORCING AND DEEPER
MOISTURE. THEN...WILL ONLY HANG ON TO SMALL EVENING POPS NORTHEAST
TUESDAY NIGHT AS THE SYSTEM PULLS AWAY AND BECOMES ABSORBED IN AN
UPPER MIDWEST SYSTEM.
COULD SEE SOME BREAKS IN THE CLOUDS ON WEDNESDAY AND WEDNESDAY
NIGHT. HOWEVER...WILL NOT CLEAR THINGS COMPLETELY OUT AS MODEL
SOUNDINGS SHOW ANOTHER STRONG INVERSION.
WITH CLOUDS EXPECTED TO HANG AROUND ON WEDNESDAY WENT WITH THE
COOLER 00Z NAM MOS...OTHERWISE MOS TEMPERATURES CLOSE ENOUGH FOR A
BLEND.
&&
.LONG TERM /THURSDAY THROUGH NEXT SUNDAY/...
ISSUED AT 237 AM EST MON DEC 15 2014
ENSEMBLES SUGGEST THE MAIN WEATHER FEATURE DURING THIS PERIOD WILL
BE AN EJECTING UPPER DISTURBANCE WHICH IS EXPECTED TO MOVE THROUGH
THE LOCAL AREA TOWARDS THE END OF THE WEEK. THERE ARE STILL
DIFFERENCES IN THE TIMING AND TRACK OF THIS SYSTEM. THE TREND IN THE
ENSEMBLES SEEMS TO BE TOWARDS A COLDER MORE SOUTHERLY TRACK...WITH
THE MAJORITY OF THE MEMBERS NOW LEANING IN THIS DIRECTION. THERE ARE
STILL SEVERAL MEMBERS THAT SUPPORT THE MORE NORTHERLY OPERATIONAL
GFS...BUT THESE ARE IN THE MINORITY.
WILL CONTINUE WITH CHANCE POPS FOR MIXED PRECIPITATION ON FRIDAY
INTO SATURDAY FOR NOW TO COVER THE WARMER SOLUTIONS. ACCUMULATING
SNOW IS POSSIBLE BY THE END OF THE WEEK.
&&
.AVIATION /DISCUSSION FOR 151800Z TAF ISSUANCE/...
ISSUED AT 1233 PM EST MON DEC 15 2014
SUBTLE IMPROVEMENTS TO MVFR CEILINGS DURING THE AFTERNOON...WITH
IFR CONDITIONS RETURNING WITH RAIN TONIGHT AND TUESDAY.
SLIGHTLY DRIER AIR HAS BEEN PULLED NORTH INTO THE OHIO VALLEY
AHEAD OF THE APPROACHING AREA OF RAIN...AND THAT HAS ENABLED
CEILINGS TO LIFT INTO THE MVFR CATEGORY AT BOTH KBMG AND KIND
EARLY THIS AFTERNOON. BASED ON CURRENT SATELLITE IMAGERY...QUITE
POSSIBLE THAT BOTH OF THESE SITES SEE BRIEF BREAKS IN THE STRATUS
AND POSSIBLE CEILINGS LIFTING TO 1500-2500FT FOR A FEW HOURS.
INITIAL SURGE OF PRECIP WILL IMPACT THE TERMINALS THRU 21Z WITH
MORE WIDESPREAD LIGHT RAINFALL FOLLOWING THEREAFTER. SOUTHEAST
WINDS TO 10 TO 15KTS ARE POSSIBLE WITH A SPORADIC HIGHER GUST
THROUGH THE AFTERNOON.
ONCE THE WIDESPREAD RAIN ARRIVES...ANY GAINS IN CEILING RISES
WILL BE LOST AS MODEL SOUNDINGS AND 950MB RH PROGS SHOW SATURATION
OF THE NEAR SURFACE LAYER TAKING PLACE. EXPECT CEILINGS TO SETTLE
BACK INTO THE IFR CATEGORY BY EARLY EVENING AND REMAIN THERE
THROUGH THE REST OF THE FORECAST PERIOD. CURRENT HI-RES MODEL
GUIDANCE INDICATES THERE SHOULD BE A 4-5 HOUR WINDOW WITH LITTLE
IF ANY RAIN AT ALL SITES BUT KLAF OVERNIGHT AS A DRY SLOT
TRANSITIONS ACROSS THE FORECAST AREA. AS LOW PRESSURE PASSES BY TO
THE NORTH TUESDAY MORNING...MOISTURE WILL BE DRAWN BACK INTO THE
REGION FROM THE NORTHWEST WITH A RESUMPTION OF LIGHT RAIN
SHOWERS. MAY ACTUALLY SEE CEILINGS AND VISIBILITIES WORSEN AFTER
DAYBREAK. WINDS WILL VEER FROM SOUTHEAST THIS EVENING TO SOUTHWEST
BY TUESDAY MORNING AND BECOME GUSTY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK/50
SHORT TERM...MK
LONG TERM...JAS
AVIATION...RYAN
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
314 PM CST Mon Dec 15 2014
.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 18Z TAFs through 18Z Tuesday Afternoon)
Issued at 1138 AM CST MON DEC 15 2014
Low cloud to be the main player in this forecast with storm system
slowly departing. Slow drying to occur through this period and
should result in gradually raising ceilings with current IFR
conditions in a few locations expected to be temporary. There is
some uncertainty on when VFR returns. Winds becoming persistent NW
in the next few hours.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...65
LONG TERM...Wolters
AVIATION...65
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1208 PM EST MON DEC 15 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EST MON DEC 15 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SPLIT FLOW PATTERN WITH A
WELL DEFINED SRN STREAM SHRTWV/LOW OVER CENTRAL KS AND A NRN STREAM
SHRTWV FROM NRN MANITOBA INTO SE SASK. AN UNSEASONABLY STRONG
DOWNSTREAM RIDGE EXTENDED FROM THE SE CONUS INTO THE ERN GREAT
LAKES. A WEAKER SHORTWAVE COMBINED WITH UPPER LEVEL DIV WITH THE
RIGHT ENTRANCE OF A 90 KNOT 250MB JET OVER NRN ONTARIO SUPPORTED AN
AREA OF LIGHT RAIN AND DRIZZLE FROM NE MN INTO WRN LAKE SUPERIOR. AT
THE SFC...SSW FLOW OF MILD/MOIST AIR PREVAILED AHEAD OF A TROUGH
EXTENDING FROM N CNTRL MN TO LOW PRES OVER CENTRAL KS. DEWPOINTS TO
AROUND 40F INTO UPPER MI ABOVE THE EXTENSIVE MELTING SNOW COVER HAS
RESULTED IN AREAS OF DENSE FOG...ESPECIALLY OVER SRN UPPER MI.
DOWNSLOPE FLOW TOWARD LAKE SUPERIOR HAS LIMITED FOG OVER THE NORTH.
TODAY...EXPECT THAT THE DENSE FOG WILL LINGER THROUGH THE MORNING
AND THEN GIVE WAY TO AT LEAST SOME IMPROVEMENT BY THIS AFTERNOON
WITH SLIGHT INFLUENCE OF DIURNAL WARMING. OTHERWISE...SOME
OCCASIONAL DRIZZLE WILL ALSO BE POSSIBLE WITH THE ABUNDANT LOW LEVEL
MOISTURE THROUGH 850 MB AND SOME WEAK LIFT AIDED BY FORCING AHEAD OF
THE COMBINED INFLUENCE OF THE NRN/SRN STREAM SHRTWVS. THE DEEPEST
MOISTURE AND STRONGER LIFT THAT WOULD SUPPORT LIGHT RAIN IS EXPECTED
OVER THE WEST BY LATE TODAY.
TONIGHT...AS THE SHORTWAVES BEGIN TO PHASE AND ANOTHER JET STREAK
LIFTS THROUGH NRN ONTARIO...PCPN WILL BECOME MORE WIDESPREAD AND
SPREAD FROM WEST TO EAST. AS THE COLDER AIR MOVES IN WITH THE LOW
MOVING TOWARD LOWER MI...THE PCPN WILL CHANGE OVER TO SNOW. A BLEND
OF THE NAM/REGIONAL-GEM 1000-850 THICKNESS WAS USED TO APPROXIMATE
THE RAIN/SNOW TRANSITION WITH SNOW TO THE FAR WEST BTWN 03Z-06Z AND
INTO CNTRL UPPER MI BY 09Z-12Z. RAIN SHOULD STILL LINGER EAST OF
P53-ESC THROUGH 12Z. THERE MAY ALSO BE BRIEF PERIOD OF SLEET WITH A
LINGERING WARM NOSE NEAR 850 MB BUT SINCE IT WILL BE VERY
TRANSIENT...NO SEPARATE SLEET WORDING WAS ADDED. NRLY WINDS WITH 850
MB TEMPS DOWN TO -8C WILL ALSO BRING SOME LAKE ENHANCEMENT INTO THE
WET FOR LOCATIONS FAVORED BY NORTH WINDS WHERE SNOWFALL TOTALS
AROUND 2 INCHES ARE POSSIBLE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 305 AM EST MON DEC 15 2014
THE LONG TERM PART OF THE FORECAST WILL MARK A RETURN TO WEATHER
MORE LIKE EARLY-MID DECEMBER THAN WHAT WAS SEEN OVER THE PAST COUPLE
DAYS. MUCH OF THE FOCUS ON THE FORECAST WILL LIE WITH THE SNOWFALL
FORECAST FOR TUESDAY INTO WEDNESDAY NIGHT...BEFORE HIGH PRESSURE
BUILDS BACK INTO THE AREA FOR THE END OF THE WORK WEEK AND THE
FIRST PART OF NEXT WEEKEND.
AT 12Z TUESDAY...THERE WILL BE TWO SHORTWAVES NEAR THE GREAT LAKES
REGION...WITH THE FIRST WAVE LOCATED OVER THE LOWER GREAT LAKES AND
THE SECOND WAVE FARTHER TO THE NORTHWEST AND STRETCHING FROM
SOUTHERN HUDSON BAY THROUGH NORTHERN MINNESOTA. WHILE THERE ARE
STILL SOME SUBTLE DIFFERENCES IN THE MODELS AND HOW THEY HANDLE THE
INTERACTION OF THESE TWO FEATURES...IN GENERAL THEY ARE PRETTY
SIMILAR IN THE EVOLUTION THROUGH THURSDAY. AT THE SURFACE AT 12Z ON
TUESDAY...THERE WILL BE A 1004MB LOW OVER SOUTHERN LAKE MICHIGAN
WITH A 1009MB TROUGH STRETCHING NORTH THROUGH NORTHERN LOWER
MICHIGAN AND INTO EASTERN ONTARIO. MEANWHILE...THE 850MB TROUGH
WILL BE SLIGHTLY BACK TO THE WEST AND WORKING ITS WAY ACROSS UPPER
MICHIGAN AND LOCATED OVER THE EAST CENTRAL U.P.. EXPECT LIGHT
PRECIPITATION TO BE OCCURRING ACROSS THE CWA WITH SNOW BEHIND THE
FRONT AND RAIN/FOG EAST OF A LINE FROM GRAND MARAIS TO RAPID RIVER.
WITH THE COLD AIR CONTINUING TO PUSH EAST THROUGH THE REST OF
EASTERN UPPER MICHIGAN ON TUESDAY...EXPECT A CHANGE TO SNOW TO
OCCUR THERE. FOR TUESDAY INTO TUESDAY NIGHT...THE LOW WILL MOVE
NORTHEAST TO SOUTHWEST QUEBEC BY WEDNESDAY MORNING...WHILE LEAVING
A MID LEVEL AND SURFACE TROUGH BACK WEST OVER THE UPPER GREAT LAKES
REGION AND TIED TO THE SECONDARY SHORTWAVE SLOWLY DROPPING
SOUTH-SOUTHEAST INTO NORTHERN WISCONSIN BY WEDNESDAY MORNING. AS
THAT OCCURS...THE DEEPER MOISTURE WILL MOVE EAST OUT OF THE
WESTERN U.P. AND FOCUS OVER THE NORTHEASTERN U.P. AND EASTERN LAKE
SUPERIOR AS THE LOW LEVEL TROUGH PIVOTS THERE. THUS...WOULD EXPECT
THE POTENTIAL FOR LIGHT TO OCCASIONALLY MODERATE SNOW TO CONTINUE
THERE TUESDAY NIGHT AND EVEN INTO WEDNESDAY UNTIL THE TROUGH
PULLS OUT WEDNESDAY NIGHT.
FARTHER WEST...THE COLDER AIR SURGING INTO THE AREA (850MB TEMPS
FALLING TO -15C BY 00Z WEDNESDAY) WILL LEAD TO LAKE ENHANCED SNOW
INITIALLY AND THEN TRANSITIONING TO LAKE EFFECT AS THE DEEPER
MOISTURE PIVOTS OUT. LOW LEVEL WINDS WILL GENERALLY BE OUT OF THE
NORTH-NORTHWEST (AROUND 340 DEGREES) AS THE SURFACE-850MB TROUGH
PIVOTS OVER EASTERN LAKE SUPERIOR. WITH THE 850MB TEMPS BEING NEAR
THE TOP OF THE CLOUD LAYER...LIFT WITHIN THE DGZ WILL BE LIMITED AND
EXPECT SNOW RATIOS TO BE IN THE 12 TO 1 RANGE INITIALLY OVER THE FAR
WEST AND RISING TO THE MID TEENS. BUT HEADING CLOSER TO THE
TROUGH AND MORE INTO THE LAKE ENHANCED PRECIPITATION (FROM THE
KEWEENAW THROUGH NORTHERN CENTRAL UPPER MICHIGAN) WOULD THINK THAT
RATIOS WOULD BE A LITTLE HIGHER (UPPER TEENS) DUE TO THE LARGER AREA
THE CLOUD WILL BE IN THE DGZ. WILL CONTINUE TO SHOW DEFINITE POPS
OVER THE NORTH-NORTHWEST WIND FAVORED LOCATIONS TUESDAY AFTERNOON
THROUGH WEDNESDAY MORNING. SNOWFALL AMOUNTS FROM SYNOPTIC AND LAKE
ENHANCED/EFFECT GENERALLY AMOUNT TO 1-2 INCHES EVERY 6 HOURS OVER
THE NORTHERN TIER OR COUNTIES AND ALSO SCHOOLCRAFT AND NORTHEAST
DELTA COUNTIES. WOULD EXPECT THE HIGHEST AMOUNTS TO OCCUR OVER THE
KEWEENAW AND THEN SOUTHEAST THROUGH THE HURON MOUNTAINS TO CHATHAM
AND NEWBERRY. WHILE THE RATES DON/T LOOK TO BE THAT HIGH...THE
PERSISTENT NATURE OF THE SNOW WOULD LEAD TO AMOUNTS FROM TUESDAY
MORNING THROUGH WEDNESDAY NIGHT TO BE IN THE 5-10 INCH RANGE IN
THE HIGHEST AREAS. THEREFORE...WILL CONTINUE TO MENTION THE SNOW
POTENTIAL IN THE HWO WITH A LONG DURATION ADVISORY LIKELY
NEEDED IN THE FUTURE.
MODELS ARE CONSISTENT ON THE SURFACE-850MB TROUGH DROPPING
SOUTHEAST AND WEAKENING WEDNESDAY AFTERNOON/NIGHT...ALLOWING DRIER
AND WARMER AIR TO MOVE INTO THE AREA ON THE EAST SIDE OF THE HIGH
NEAR KINL. THIS WILL LEAD TO A VERY QUICK END TO THE LAKE
EFFECT/ENHANCED SNOW LATE WEDNESDAY NIGHT INTO THURSDAY MORNING AND
WILL FOLLOW THAT IDEA FOR THE POPS. THAT HIGH PRESSURE WILL LEAD TO
DRY AND MOSTLY CLEAR CONDITIONS FOR THE REST OF THE WORK WEEK.
MODELS DIVERGE HEADING INTO THE WEEKEND...BUT THE GENERAL IDEA IS
FOR A SHORTWAVE AND WEAK SURFACE TROUGH TO SLIDE THROUGH THE AREA AT
SOME POINT DURING THE WEEKEND. THEREFORE...WILL SHOW INCREASING
CLOUDS ON SATURDAY AND SLIGHT CHANCE POPS FOR SATURDAY NIGHT INTO
SUNDAY. HIGHS ON WEDNESDAY LOOK TO BE A TOUCH BELOW NORMAL
(LOW-MID 20S)...BUT THEN EXPECT A GRADUAL WARM UP TO ABOVE NORMAL
VALUES BY SATURDAY (UPPER 20S AND LOWER 30S) WITH THE RELATIVELY
WARM NORTHERLY FLOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1208 PM EST MON DEC 15 2014
CONTINUED LOW VIS/LOW CIG EVENT THROUGH THIS FORECAST PERIOD AT ALL
SITES WITH CONDITIONS REMAINING IN LIFR/VLIFR THROUGH LATE TONIGHT
BEFORE COLDER AIR CHANGES THE LIQUID PRECIPITATION OVER TO SNOW.
WILL GET GUSTY WITH NORTH WINDS WITH THE COLD AIR AND ONCE COLD AIR
ARRIVES...CONDITIONS WILL SLOWLY IMPROVE TO IFR/LIFR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 534 AM EST MON DEC 15 2014
PATCHY FOG WILL LINGER ACROSS MUCH OF LAKE SUPERIOR TODAY AS THE AREA
REMAINS IN THE WARM/MOIST AIRMASS. A LOW ACROSS MINNESOTA WILL PUSH
OVER WESTERN LAKE SUPERIOR THIS AFTERNOON...AND THEN E LAKE SUPERIOR
THIS EVENING REDUCING THE FOG. THE SRN PORTION OF THE TROUGH WILL
SHIFT FROM KS TO IA TODAY AND TO 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...
DENSE FOG ADVISORY UNTIL 8 PM EST /7 PM CST/ THIS EVENING FOR
MIZ001>007-009>014-084-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 8 PM EST THIS EVENING FOR LMZ221-248-
250.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS JACKSON MS
1105 AM CST MON DEC 15 2014
.UPDATE...SATELLITE IMAGERY SHOWS THE NEARLY STACKED LOW SPINNING
OVER NORTHWEST MISSOURI WITH THE TRAILING COLD FRONT NEARING THE
ARKLATEX. DRIER AIR WAS NOTED WRAPPING AROUND THE LOW AND HAS
CLEARED SKIES WELL AHEAD OF THE COLD FRONT. OVER OUR CWA A BROKEN
DECK OVER CLOUD COVER WAS NOTED MAKING THE TEMPERATURE FORECAST A
LITTLE DIFFICULT. THE COLD SPOT TRAILING BEHIND WAS STILL OUR
NORTHEAST ZONES. LOCAL RADARS SHOWED TWO PRIMARY BANDS OF PCPN. THE
LEAD BAND HAS PUSHED EAST OF THE NATCHEZ TRACE AND WILL SWING EAST
OF OUR CWA BY MID AFTERNOON. THE TRAILING BAND WAS MOVING INTO OUR
SOUTHEAST ARKANSAS COUNTIES AND NORTHEAST LOUISIANA PARISHES AND
WILL ADVANCE ACROSS OUR CWA THIS AFTERNOON AND EARLY EVENING. MUCH
OF OUR CWA HAD SURFACE DEW POINTS STILL IN THE MID 50S BUT OVER OUR
LOUISIANA PARISHES JUST AHEAD OF THE TRAILING LINE OF CONVECTION
LOWER 60 DEW POINTS HAVE POOLED. HIRES MODELS AND THE NAM STILL SHOW
POTENTIAL FOR SOME MID 60 DEW POINTS OVER OUR SOUTHWEST ZONES THIS
AFTERNOON WITH TEMPERATURES APPROACHING THE LOWER 70S. WITH
INCREASING SHEAR AND HELICITY THIS AFTERNOON THERE MAY BE JUST
ENOUGH INSTABILITY FOR A STORM OR TWO CAPABLE OF STRONG WIND GUSTS.
THIS POTENTIAL LOOKS TO WAIN BY EARLY EVENING AND THIS CHANCE
APPEARS LOW BUT WL MAINTAIN OUR OUTLOOK AREA AND MENTION IN THE HWO.
/22/
&&
.AVIATION...A MIX OF MVFR/VFR CONDITIONS ARE OCCURRING ACROSS THE
ARKLAMISS THIS MORNING AS SHOWERS MOVE UP GENERALLY ALONG THE
NATCHEZ TRACE CORRIDOR. A COLD FRONT WILL MOVE INTO THE DELTA THIS
AFTERNOON AND MOVE ACROSS THE AREA THROUGH THE EVENING HOURS AND
THIS WILL BRING ANOTHER ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS
TO MOST TAF SITES. THE WINDS ARE CURRENTLY OUT OF THE SOUTH AT
7-12KTS AND WILL BECOME GUSTY THIS AFTERNOON. THE WINDS WILL SWING
AROUND TO THE WEST BEHIND THE FRONT LATER THIS EVENING INTO THE
OVERNIGHT HOURS./15/
&&
.PREV DISCUSSION... /ISSUED 340 AM CST MON DEC 15 2014/
SHORT TERM...TODAY THROUGH TUESDAY NIGHT...FOCUS FOR THIS TIME FRAME
WILL BE FOR TODAY AND TONIGHT. WV IMAGERY SHOWING A WRAPPED UP MID
LEVEL COLD CORE QUICKLY LIFTING NE OUT OF N OK/E KS. SYSTEM MOVEMENT
HAS BEEN AS SUCH TO NOT ALLOW LOW LEVEL MOIST SOUTHERLY FLOW TO
BECOME FIRMLY ESTABLISHED...IN FACT...NARROW WARM/MOIST AXIS IS
PRETTY MUCH ALIGNED WITH ITS ATTENDANT COLD FRONT...CURRENTLY MOVING
THROUGH NW AR/SE OK/NE TX. MAJORITY OF ONGOING CONVECTION APPEARS
ELEVATED...ALTHOUGH SOME OVER SE TX MAY BE MORE ROOTED NEAR THE
SURFACE.
WHILE CONFIDENCE IS HIGH THAT THE AREA WILL BE AFFECTED WITH SHOWERS
AND THUNDERSTORMS TODAY AS THE FRONT MOVES THROUGH...FORECAST
PROBLEM WILL BE JUST HOW STRONG STORMS CAN GET. AMBIENT SHEAR WILL
NOT BE A PROBLEM AS 0-3KM SRH VALUES RANGE FROM 300-400 M2/S2...AND
0-1KM VALUES 250-350 M2/S2 DURING THE AFTERNOON/EARLY EVENING TIME
FRAME. THE PROBLEM COMES IN WITH INSTABILITY AND WHETHER IT CAN ROOT
ITSELF NEAR THE GROUND. THE BEST POSSIBILITY FOR THIS TO OCCUR LOOKS
TO BE OVER SW PORTIONS OF THE AREA WHERE SURFACE DEWPOINTS NEAR 65
WILL NOSE UP IMMEDIATELY AHEAD OF THE FRONTAL BOUNDARY THIS
AFTERNOON. AS THIS OCCURS...MIXED LAYER CAPES WILL RISE TO THE
500-700 J/KG RANGE. HRRR AND NAM ARE INDICATING AN INCREASE IN
CONVECTION OVER OUR SW PORTIONS DURING THE AFTERNOON/EARLY EVENING.
THE HRRR IS ALSO INTERMITTENTLY SHOWING SOME DECENT UPDRAFT
HELICITIES WITH SOME OF ITS FORECAST STORMS. WILL...THEREFORE...
OUTLOOK A LIMITED SEVERE/TORNADO THREAT OVER THESE AREAS THIS
AFTERNOON/EARLY EVENING. THREAT SHOULD DIMINISH RAPIDLY BY MID
EVENING WITH THE LOSS OF HEATING./26/
LONG TERM...WEDNESDAY THROUGH MONDAY...AT THE MIDDLE OF THE WORK WEEK
THE REGION WILL BE UNDER THE INFLUENCE OF ZONAL MEAN RIDGING WITH
SURFACE HIGH PRESSURE CENTERED OVER THE MIDDLE MISSISSIPPI VALLEY.
UPPER TROUGHING OVER THE SOUTHERN ROCKIES WILL CAUSE THE MEAN FLOW
TO BE MORE SOUTHWESTERLY BY WEDNESDAY NIGHT INTO THURSDAY. A WEAK
DISTURBANCE COMING FROM THE PLAINS WILL BRING SOME ISENTROPIC LIFT
FOR SOME LIGHT RAIN. THE BEST LIFT WILL BE ACROSS THE SOUTH.
MEANWHILE OUR ROCKIES SYSTEM WILL BE PUSHING INTO THE PLAINS ON
FRIDAY. THERE IS EVEN A WIDER RANGE OF SOLUTIONS FOR THIS SYSTEM FOR
FRIDAY INTO FRIDAY NIGHT. THE GFS CONTINUES TO BE THE FARTHEST NORTH
WITH THE SURFACE LOW GOING FROM THE SOUTHERN PLAINS TO THE MIDSOUTH
REGION. THE EURO SEEMS TO HAVE GONE A LITTLE FARTHER NORTH ON THIS
RUN. IT TAKES THE SURFACE LOW FROM SOUTH CENTRAL LOUISIANA THROUGH
THE NATCHEZ TRACE CORRIDOR FOR FRIDAY NIGHT. THE CANADIAN MEANWHILE
KEEPS IT SOUTH ALONG THE GULF COAST AND PUSHES IT INTO NORTHERN
FLORIDA BY SATURDAY MORNING. THE GFS MEAN ENSEMBLE IS SIMILAR TO THE
EURO TRACK WITH A WEAKER SURFACE LOW. SO WITH THIS IN MIND WILL GO
WITH THE MIDDLE OF THE ROAD WITH THE WEAKER GFS ENSEMBLE SOLUTION.
THE ENSEMBLE HAS THE SHORTWAVE TROUGH OVER THE MID MISSISSIPPI
VALLEY ON FRIDAY NIGHT. SO WITH THIS IN MIND WILL PUSH THE ISOLATED
CONVECTIVE CHANCES A LITTLE FARTHER NORTH ACROSS THE REGION AROUND
THE SURFACE LOW TRACK FOR FRIDAY NIGHT. THE RAINS WILL CLEAR OUT ON
SATURDAY MORNING. SHORTWAVE FLAT RIDGING WILL DEVELOP ACROSS THE
REGION ON SUNDAY INTO MONDAY.
HAVE ALIGNED TEMPS AND POPS TOWARD THE GFS MEAN ENSEMBLE PATH OF THE
SURFACE LOW. FOR THE REST OF THE PERIOD ON POPS AND TEMPS MADE SOME
SLIGHT ADJUSTMENTS./17/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 71 43 59 35 / 65 45 3 2
MERIDIAN 69 47 61 34 / 55 49 3 2
VICKSBURG 73 41 59 33 / 65 17 2 2
HATTIESBURG 72 52 65 35 / 53 47 3 2
NATCHEZ 72 44 59 34 / 65 27 2 2
GREENVILLE 70 40 55 33 / 65 14 2 2
GREENWOOD 70 42 55 33 / 65 32 2 2
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
22/15/26/17
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
315 PM CST MON DEC 15 2014
...CORRECTION FOR TYPO/WORDING...
.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 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1135 AM CST MON DEC 15 2014
UPPER LEVEL LOW WILL CONTINUE TO JOG TO THE NORTHEAST TOWARD THE
GREAT LAKES REGION THIS AFTERNOON AND TONIGHT. THE WIDESPREAD SNOW
CURRENTLY OCCURRING WILL BEGIN TO DECREASE IN COVERAGE AND
INTENSITY...RECENT SATELLITE TRENDS AGREE WITH THIS TREND AS THE
IR CHANNEL INDICATES WARMING CLOUD TOPS ACROSS THE REGION. THE
FORECAST CALLS FOR IMPROVING VISIBILITY AT KLBF AND KVTN THIS
AFTERNOON. THEREAFTER CEILINGS REMAIN MVFR OR LOWER THROUGH THE
FORECAST PERIOD. GUSTY NORTHWEST WIND WILL CONTINUE TO BUFFER THE
REGION...AND WHILE NOT IN THE OFFICIAL TAF FORECAST...PERIODIC
BLSN IS A CONCERN AT ALL TAF SITES THAT RECEIVED ACCUMULATING
SNOW. WIND SPEEDS WILL WEAKEN OVERNIGHT AS THE PRESSURE GRADIENT
RELAXES. FORECAST CONFIDENCE IS STRONG IN THE OVERALL
PATTERN...BUT UPDATES IN VISIBILITY/CEILINGS MAY BE NEEDED AS THE
STORM EXITS TO OUR EAST.
&&
.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...JACOBS
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
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
&&
.AVIATION...
18Z TAF CYCLE
VFR CONDITIONS TO PERSIST THROUGH THE TAF PERIOD WITH LIGHT WINDS
AND INCREASING HIGH CLOUDINESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 24 49 28 46 / 5 5 10 20
DULCE........................... 16 46 20 43 / 5 5 10 20
CUBA............................ 20 44 24 42 / 0 5 10 30
GALLUP.......................... 21 51 24 46 / 0 0 10 40
EL MORRO........................ 18 46 22 42 / 0 0 10 40
GRANTS.......................... 20 49 23 46 / 0 0 10 30
QUEMADO......................... 27 47 28 42 / 0 0 10 30
GLENWOOD........................ 32 58 32 53 / 0 0 5 30
CHAMA........................... 12 43 16 41 / 5 5 10 30
LOS ALAMOS...................... 25 41 28 40 / 0 0 5 20
PECOS........................... 22 40 26 41 / 0 0 5 10
CERRO/QUESTA.................... 13 39 17 38 / 0 5 5 20
RED RIVER....................... 16 36 18 35 / 0 5 5 20
ANGEL FIRE...................... 7 40 14 38 / 0 0 5 20
TAOS............................ 15 43 19 41 / 0 0 5 20
MORA............................ 20 45 24 44 / 0 0 0 10
ESPANOLA........................ 23 47 26 45 / 0 0 5 10
SANTA FE........................ 25 43 27 42 / 0 0 5 10
SANTA FE AIRPORT................ 23 47 26 47 / 0 0 5 10
ALBUQUERQUE FOOTHILLS........... 27 49 30 49 / 0 0 5 5
ALBUQUERQUE HEIGHTS............. 29 51 32 51 / 0 0 5 5
ALBUQUERQUE VALLEY.............. 25 52 29 52 / 0 0 0 5
ALBUQUERQUE WEST MESA........... 28 50 30 51 / 0 0 0 10
LOS LUNAS....................... 25 51 28 51 / 0 0 0 5
RIO RANCHO...................... 29 50 31 50 / 0 0 5 10
SOCORRO......................... 29 55 33 55 / 0 0 0 5
SANDIA PARK/CEDAR CREST......... 24 44 28 44 / 0 0 0 10
TIJERAS......................... 22 45 27 46 / 0 0 0 5
MORIARTY/ESTANCIA............... 17 46 23 47 / 0 0 0 5
CLINES CORNERS.................. 22 43 26 46 / 0 0 5 5
GRAN QUIVIRA.................... 27 47 30 47 / 0 0 0 5
CARRIZOZO....................... 29 53 32 51 / 0 0 0 5
RUIDOSO......................... 28 51 31 50 / 0 0 5 5
CAPULIN......................... 18 42 23 46 / 0 0 0 10
RATON........................... 17 46 20 49 / 0 0 0 10
SPRINGER........................ 19 48 22 50 / 0 0 0 5
LAS VEGAS....................... 21 45 24 50 / 0 0 5 5
CLAYTON......................... 22 48 28 53 / 0 0 0 5
ROY............................. 21 44 26 51 / 0 0 0 5
CONCHAS......................... 27 49 31 56 / 0 0 0 5
SANTA ROSA...................... 27 48 31 56 / 0 0 0 5
TUCUMCARI....................... 25 53 31 60 / 0 0 0 5
CLOVIS.......................... 26 51 31 57 / 0 0 0 5
PORTALES........................ 27 52 32 58 / 0 0 0 5
FORT SUMNER..................... 28 51 32 57 / 0 0 0 5
ROSWELL......................... 30 53 32 60 / 0 0 0 0
PICACHO......................... 30 49 32 57 / 0 0 0 5
ELK............................. 30 49 33 54 / 0 0 0 5
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
335 PM CST MON DEC 15 2014
.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 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1245 PM CST MON DEC 15 2014
GUSTY NORTH WINDS WILL CONTINUE THROUGH THE DAY AND RELAX A LITTLE
BY EARLY EVENING...BUT NOT TOO MUCH. WILL LIKELY SEE HIGHER
SUSTAINED WINDS HOLDING THROUGH THE NIGHT WITH A LITTLE LESS
GUSTINESS TO THE WIND. AFTER 12Z TUE WINDS WILL CONTINUE TO
DECREASE. MAIN QUESTION IS CLOUDS AND CLOUD HEIGHTS. THERE ARE SOME
HOLES NORTH OF WINNIPEG BUT NOT TOO CONFIDENT ANY OF THESE WILL HOLD
TOGETHER AS THEY DROP SOUTHWARD SO HAVE STAYED ON THE PESSIMISTIC
SIDE. ROSE HEIGHTS SOME THRU THE AFTERNOON BEFORE FALLING AGAIN
TONIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...VOELKER
LONG TERM...GODON/VOELKER
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1253 PM CST MON DEC 15 2014
.UPDATE...
ISSUED AT 1245 PM CST MON DEC 15 2014
CURRENT HEADLINES CONTINUES TO BE THE MAIN FORECAST CHALLENGE THIS
AFTERNOON. PERSISTENT PCPN BAND FROM KMVX-88D CONTINUES ACROSS EXTREME
SE NE INTO WEST CENTRAL/NORTH CENTRAL MN. THIS BAND ASSOCIATED
WITH 800-750MB FRONTOGENETIC FORCING ALONG WITH SOME UPPER LEVEL
DIVERGENCE FROM JET MAXIMA. MESOSCALE MODELS GRADUALLY SHIFT FEATURE SE
THROUGH THE AFTERNOON WHICH APPEARS TO BE GRADUALLY TAKING PLACE.
PCPN PHASE WITHIN BAND PRIMARILY -SN HOWEVER SOME SLEET AND ZR
CONTINUES TO BE REPORTED. ALTHOUGH SNOW/ICING AMOUNTS WILL BE
LIGHT ANY ADDITIONAL PCPN WILL MAINTAIN HAZARDOUS TRAVEL
CONDITIONS. FOR THIS TRANSITIONED ZR ADVISORY OVER TO A WINTER WX
ADVISORY TO BETTER HANDLE MIXED PCPN AND EXTENDED UNTIL 4PM.
CONFINED HEADLINES TO FAR SE FA AND EXPIRED HEADLINES FARTHER
NORTH. OTHERWISE MSAS PRESSURE RISE MAXIMA DROPPING INTO THE
SOUTHERN FA WHERE STRONGEST WINDS EXIST. ISOLATED LOCATIONS NOSING
INTO WIND ADVISORY CRITERIA AT TIMES HOWEVER NOT WIDESPREAD ENOUGH
TO WARRANT HEADLINES. NO OTHER CHANGES.
UPDATE ISSUED AT 945 AM CST MON DEC 15 2014
MADE ADJUSTMENTS TO CURRENT HEADLINES. EXPIRED ADVISORY CENTRAL
AND NORTHERN VALLEY AND ADJACENT AREAS OF NW MN. CANNOT RULE OUT
SOME ISOLATED POCKETS OF -FZDZ HOWEVER SHOULD NOT BE ENOUGH TO
AFFECT ROADWAYS. EXTENDED ADVISORY UNTIL 1 PM FOR AREAS ALONG AND
SOUTH-EAST OF A LINE FROM BAUDETTE TO FOSSTON...FARGO AND VALLEY CITY.
STILL GETTING REPORTS OF MORE SIGNIFICANT WINTRY MIX AND HAZARDOUS TRAVEL.
WILL REVISIT EARLY THIS AFTERNOON TO SEE IF ANY AREAS ACROSS WEST
CENTRAL TO NORTH CENTRAL MN WILL NEED AN EXTENSION IN TIME. NO
OTHER SIGNIFICANT CHANGES.
UPDATE ISSUED AT 645 AM CST MON DEC 15 2014
MOST OF THE FREEZING DRIZZLE HAS MOVED SOUTH AND EAST OUT OF THE
GFK AREA...BUT WITH RECENT WET CONDITIONS AND COLD TEMPS
CONDITIONS CONTINUE TO BE SLICK. IN ADDITION...MORE RETURNS ARE
STARTING TO DEVELOP OVER THE SOUTHERN FORECAST AREA AND SHOULD
CONTINUE OVER THE NEXT FEW HOURS. THUS WILL KEEP THE ADVISORY
GOING FOR NOW.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 402 AM CST MON DEC 15 2014
MAIN HEADACHE IS FREEZING DRIZZLE AND HOW LONG IT WILL LAST TODAY.
THE SPLIT FLOW ALOFT CONTINUES WITH THE NORTHERN BRANCH SHORTWAVE
DIGGING DOWN THROUGH SOUTHERN CANADA AND THE SOUTHERN CUT OFF LOW
MOVING THROUGH KANSAS ON ITS WAY TO IOWA. THE SFC LOW HAS MOVED TO
THE EAST OF THE CWA AND MOST SITES HAVE SEEN A SHIFT TO
NORTHWESTERLY WINDS AND GOOD COLD AIR ADVECTION. A FEW SPOTS IN
THE EASTERN TIER ARE HANGING ABOVE FREEZING BUT THE REST HAVE
FALLEN BELOW. LOW LEVEL MOISTURE CONTINUES TO BE ABUNDANT EVEN
BEHIND THE COLD FRONT AND MODEL SOUNDINGS INDICATE A DRY LAYER
ALOFT WHERE TEMPS WOULD BE COLD ENOUGH FOR ICE GROWTH...SO MOST OF
OUR PRECIP WILL BE SUPERCOOLED WATER. THE RAP AND NAM BOTH HAVE
THE LOW LEVEL OMEGA IN THAT SATURATED LAYER CONTINUING TO SHOW
SOME RISING MOTION. WILL EXTEND THE FREEZING RAIN ADVISORY UNTIL
15Z AND EXTEND IT EAST AS TEMPS HAVE BEEN FALLING AND VIS HAVE
BEEN RISING WHERE OUR DENSE FOG HEADLINE WAS OVER THE EASTERN
COUNTIES.
THE SOUTHERN BRANCH SHORTWAVE WILL STAY MAINLY TO OUR SOUTHEAST
TODAY...BUT KEPT SOME LOW POPS TO BLEND IN AS THE SYSTEM PASSES
BY. TONIGHT...THE NORTHERN BRANCH SHORTWAVE WILL DIG DOWN INTO
NORTHEASTERN MN AND SFC HIGH PRESSURE WILL BUILD INTO THE WESTERN
PLAINS. SAT LOOP SHOWS FAIRLY CONSISTENT CLOUDS WELL TO OUR NORTH
AND WEST UNTIL ON THE WEST SIDE OF THE SFC RIDGE CURRENTLY ALONG
THE SASKATCHEWAN/ALBERTA BORDER. TIME HEIGHTS CONTINUE TO SHOW A
LOT OF RH AT LOW LEVELS SO THINK THAT CLOUDS WILL HANG ON LONGER
THAN EXPECTED. BUMPED UP CLOUDS AND RAISED LOWS A FEW DEGREES
ACCORDINGLY FOR TONIGHT.
TUESDAY...THE SFC HIGH PRESSURE WILL MOVE EASTWARD INTO THE
CWA...BUT THE AXIS WILL STILL BE WEST OF MOST OF OUR COUNTIES SO
KEPT CLOUDS HIGHER A BIT LONGER ALTHOUGH NOT COMPLETELY SOCKED IN.
EVEN WITH A BIT OF SUN COLD AIR ADVECTION WILL KEEP THE TEMPS IN
THE TEENS FOR TUESDAY AND WITH BREEZY NORTHWEST WINDS IT WILL FEEL
RATHER RAW.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 AM CST MON DEC 15 2014
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...SPLIT FLOW CONTINUES WITH
SFC HIGH PRESSURE CONTINUING OVER THE REGION. TEMPS WILL REMAIN
COLD EVEN AS CLOUDS START TO DECREASE. LOWS WILL BE IN THE SINGLE
DIGITS AND HIGHS IN THE TEENS.
THURSDAY THROUGH SUNDAY...LONG WAVE TROUGH OFF THE WEST COAST OF
CANADA REMAINS THROUGH DAY 5 THEN RETROGRADES/RE-ESTABLISH
FARTHER WEST THROUGH THE END OF THE PERIOD. SPLIT FLOW CONTINUES
ACROSS NORTH AMERICA THROUGH THE PERIOD. FLOW ALOFT REMAINS
RELATIVELY PROGRESSIVE THROUGH THE PERIOD. MUCH ABOVE NORMAL
HEIGHTS REMAIN OVER HUDSON BAY AND SOUTHERN CANADA.
GFS AND ECMWF WERE SIMILAR AT THE BEGINNING OF THE PERIOD. HOWEVER
THE GFS WANT TO DEVELOP A STRONGER TROUGH OVER CENTRAL
CANADA/NORTHERN PLAINS ON FRI AND SAT WHICH IS OUT OF PHASE WITH THE
ECMWF FOR THE REST OF THE PERIOD. WILL PREFER THE ECMWF.
LITTLE OR NO PRECIP THROUGH THE EXTENDED FORECAST. LITTLE CHANGE TO
TEMPS ON THU AND FRI. HIGH TEMPS DECREASED A DEGREE OR TWO FOR SAT
AND SUN MOST PLACES COMPARED TO THE PREVIOUS FORECAST PACKAGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1245 PM CST MON DEC 15 2014
GUSTY NORTH WINDS WILL CONTINUE THROUGH THE DAY AND RELAX A LITTLE
BY EARLY EVENING...BUT NOT TOO MUCH. WILL LIKELY SEE HIGHER
SUSTAINED WINDS HOLDING THROUGH THE NIGHT WITH A LITTLE LESS
GUSTINESS TO THE WIND. AFTER 12Z TUE WINDS WILL CONTINUE TO
DECREASE. MAIN QUESTION IS CLOUDS AND CLOUD HEIGHTS. THERE ARE SOME
HOLES NORTH OF WINNIPEG BUT NOT TOO CONFIDENT ANY OF THESE WILL HOLD
TOGETHER AS THEY DROP SOUTHWARD SO HAVE STAYED ON THE PESSIMISTIC
SIDE. ROSE HEIGHTS SOME THRU THE AFTERNOON BEFORE FALLING AGAIN
TONIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR NDZ053.
MN...WINTER WEATHER ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR MNZ017-
024-027>032-040.
&&
$$
UPDATE...VOELKER
SHORT TERM...JR
LONG TERM...JR/HOPPES
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1217 PM CST MON DEC 15 2014
.UPDATE...
ISSUED AT 1208 PM CST MON DEC 15 2014
FREEZING DRIZZLE HAS ENDED OVER MOST LOCATIONS...WITH ONLY A FEW
VERY SMALL AREAS POSSIBLY REMAINING OVER FAR SOUTH CENTRAL INTO
THE FAR SOUTHERN JAMES RIVER VALLEY. OTHERWISE...MAINLY QUIET
WEATHER WITH OVERCAST SKIES AND A FEW FLURRIES WILL CONTINUE.
UPDATE ISSUED AT 856 AM CST MON DEC 15 2014
MAIN CHANGE FOR MORNING UPDATE WAS TO EXTEND THE FREEZING RAIN
ADVISORY THROUGH THE REMAINDER OF THE MORNING. VARIOUS LOCATIONS
THROUGHOUT THE AREA CONTINUE TO REPORT A LIGHT DRIZZLE AFTER A
PERIOD OF LIGHT SNOW...WHICH IS SUPPORTED BY LATEST RAP SOUNDING
ANALYSIS WHICH CONTINUES TO INDICATE DRYING AT MID-LEVELS WITH A
MOIST LOW LEVEL. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 634 AM CST MON DEC 15 2014
LATEST RAPID UPDATE CYCLE FORECAST SOUNDINGS SHOW LOW LEVEL
SUPER COOLED WATER WITH DRY AIR ABOVE ACROSS THE WEST AND CENTRAL.
SEEING BEACH AWOS WITH LIGHT FREEZING RAIN AS WELL AS STANLEY AND
MANDAN. WILL NEED THE ADVISORY THROUGH 9 AM.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CST MON DEC 15 2014
LIGHT FREEZING RAIN/DRIZZLE IS THE MAIN HIGHLIGHT IN THIS PERIOD.
AFTER COLLABORATING WITH NEIGHBORING OFFICES HAVE OPTED TO EXTEND
THE ONGOING FREEZING RAIN ADVISORY UNTIL 15Z MONDAY FOR SOUTHWESTERN
AND MOST OF CENTRAL NORTH DAKOTA.
NAM/GFS...AND ESPECIALLY THE NEAR TERM RAP13 BUFKIT SOUNDINGS
MAINTAIN A SATURATED LOW LEVEL SUBFREEZING LAYER WITH AMPLE LIFT
PER OMEGA FIELD TO KEEP A MENTION OF FREEZING PRECIPITATION GOING.
SOUNDINGS SHOW A TEMPORARY MOIST LAYER IN THE -8C TO -20C LAYER...BUT
THIS IS FORECAST TO WANE AND BECOME DRIER THROUGH MID MORNING.
THUS WITH AN ABSENT OF ICE CRYSTALS FORMING ALOFT...ATTENTION
TURNS BACK TO THE SATURATED LOWER LEVELS WHERE TEMPERATURES RANGE
BETWEEN -5C AND -10C. EXPECT MOSTLY SUPERCOOLED WATER DROPLETS
WITH LIGHT FREEZING RAIN/DRIZZLE. HOWEVER...SOME ICE CRYSTAL
FORMATION MAY OCCUR NEAR -10C SO LIGHT SNOW MAY ALSO DEVELOP AT
TIMES. BOTTOM LINE IS WITH LOW LEVEL LIFT BEING MAINTAINED IN THIS
SATURATED LAYER...THE THREAT FOR ADDITIONAL FREEZING PRECIPITATION
WARRANTS AN EXTENSION THROUGH MID MORNING. IMPACT TO TRAVEL
REMAINS HAZARDOUS WITH SEVERAL NO TRAVEL ADVISORIES ISSUED
OVERNIGHT DUE TO ICY ROADS. BOWMAN RADAR AND SURFACE OBSERVATIONS
SHOW AN AREA OF SNOW MOVING SOUTH...WITH BEACH TRANSITIONING FROM
SNOW BACK TO FREEZING PRECIPITATION. ANY SNOWFALL ACCUMULATIONS
WILL REMAIN LIGHT...LESS THAN A QUARTER INCH...BUT WILL ADD TO ICY
CONDITIONS AND HAZARDOUS TRAVEL.
NORTHERN UPPER TROUGH PER LATEST WATER VAPOR IMAGERY ACROSS SOUTHERN
SASKATCHEWAN AND MANITOBA WILL SWING THROUGH NORTH DAKOTA TODAY.
COLD AIR ADVECTION WITH BRISK NORTHWEST WINDS OF 15 TO 30 MPH
CAN BE EXPECTED TODAY. EXTENSIVE STRATUS DECK ACROSS EASTERN
ALBERTA...THROUGH SASKATCHEWAN AND MANITOBA WILL PUSH SOUTHEAST.
HAVE INCREASED SKY GRIDS TO REFLECT CLOUDY CONDITIONS TODAY INTO
TONIGHT. IN DOING SO OVERNIGHT MINIMUMS WERE INCREASED. THE DAY
SHIFT CAN RE-EVALUATE THIS LATER TODAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 313 AM CST MON DEC 15 2014
.LONG TERM...TUESDAY THROUGH SUNDAY...
THE EXTENDED WILL FEATURE AN H500 SEPARATION OF FLOW WITH A NORTHERN
AND SOUTHERN STREAM LEAVING THE NORTHERN PLAINS IN A RATHER WEAK
FLOW ALOFT. THIS BLOCKING PATTERN WILL CUT OFF THE MOISTURE TO THE
SOUTH AND LEAVE JET STREAM ENERGY TOO FAR NORTH. WITH LITTLE IN
SHORT WAVE ENERGY TO BRING PRECIPITATION CHANCES THE EXTENDED PERIOD
IS LEFT DRY. AGAIN...CONCERNS ABOUT WEAK FLOW ALOFT AND LACK UP
UPPER LEVEL VENTILATION AND A STAGNANT AIR PATTERN THERE WILL BE
CONCERNS ABOUT LOW LEVEL STRATUS AND FOG. BEST OPTION HERE IS TI
DEAL WITH THESE FEATURES IF AND WHEN THEY DEVELOP. FOR NOW BEGAN THE
EXTENDED ON TUESDAY WITH RESIDUAL CLOUDINESS THROUGH MOST OF THE DAY
AS THE CIRCULATION AROUND AN UPPER LOW MAINTAINS A COOL AND MOIST
FLOW OVER THE STATE. AFTER TUESDAY THE FLOW ALOFT BECOMES WEAK AS
THE GREAT LAKES LOW MOVES EAST AND THE NORTHERN PLAINS END UP
BETWEEN THE NORTHERN AND SOUTHERN STREAM FLOWS. A WEAK IMPULSE IN
THE SOUTHERN STREAM WILL BRUSH ACROSS THE CENTRAL PLAINS WEDNESDAY
THROUGH FRIDAY. THIS LEAVE THE NORTHERN PLAINS DRY WITH A SLOW
MODERATING TREND TO TEMPERATURES BY THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1208 PM CST MON DEC 15 2014
WIDESPREAD MVFR TO IFR CIGS WILL REMAIN OVER THE AREA THROUGH THE
FORECAST PERIOD. LCL FREEZING DRIZZLE WILL BE POSSIBLE THROUGH
THIS AFTERNOON OVER FAR SOUTH CENTRAL INTO SOUTHEAST NORTH DAKOTA.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...KS
LONG TERM...WAA
AVIATION...JJS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
305 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 TONIGHT/...
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 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 /18Z MONDAY 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...TK
SHORT TERM...TK
LONG TERM...ADAMS
AVIATION...ADAMS
MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
542 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 SE 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 AND COLD/OCCLUDED FRONT MOVE THROUGH ON
TUE...BRINGING A PERIOD OF RAIN SHOWERS. REDUCTIONS REMAIN
LIKELY...ESP IN THE NORTHERN AND CENTRAL MTNS. MAIN PRECIP WILL
MOVE OUT TUE EVE...BUT WE/LL TRANSITION BACK TO A NW FLOW REGIME
AND TEMPS COLD ENOUGH TO BRING A RETURN OF SCT SNOW SHOWERS TO THE
WESTERN AND NORTHERN HIGHER TERRAIN /ALONG WITH LOCAL REDUCTIONS/.
GENERALLY VFR ELSEWHERE.
OUTLOOK...
WED...LOW CIGS/SHSN LIKELY W MTNS.
THU-FRI...NO SIG WX EXPECTED.
SAT...POSS FOR RAIN/SNOW AND REDUCTIONS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RXR
NEAR TERM...RXR
SHORT TERM...
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/RXR
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1009 AM CST MON DEC 15 2014
.UPDATE...
SHOWERS AND ISOLATED STORMS HAVE CLEARED OUT OF ALL NORTH TEXAS
COUNTIES AND GENERALLY SUNNY SKIES ARE EXPECTED FOR THE REST OF
THE DAY. THE ONLY POSSIBLE EXCEPTION WOULD BE THE NORTHEAST
LOCATIONS FROM SHERMAN TO PARIS...WHERE SOME WRAP-AROUND MOISTURE
FROM THE LOW PRESSURE SYSTEM EXITING TO THE NORTHEAST MAY LEAD TO
OCCASIONAL STRATOCUMULUS CLOUDS THIS AFTERNOON. IF THESE CLOUDS
THICKEN MORE THAN EXPECTED...HIGH TEMPS WOULD LIKELY REMAIN IN THE
MID 50S. OTHERWISE UPPER 50S TO LOWER AND MIDDLE 60S CAN BE
EXPECTED THIS AFTERNOON.
30
&&
.AVIATION...
/ISSUED 544 AM CST MON DEC 15 2014/
FOR THE 12Z TAFS...THE PRIMARY FORECAST CONCERN IS CROSSWIND
CONDITIONS ACROSS DFW AREA TAF SITES TODAY.
FOR THE TAFS...CLOSELY FOLLOWED LAMP AND RAP GUIDANCE FOR WIND
DIRECTION AND INTENSITY THROUGHOUT THE DAY TODAY. WINDS WILL
MAINTAIN A STRONG WESTERLY COMPONENT THROUGHOUT THE DAY...STARTING
OFF JUST SOUTH OF DUE WEST...VEERING TO JUST NORTH OF DUE WEST BY
THE MID-MORNING HOURS. HAVE THE CURRENT FORECAST INTENSITY OF
THESE WESTERLY WINDS HOLDING JUST BELOW 20 KTS THIS
MORNING...INTRODUCING SOME GUSTS TO 25 KTS DURING THE PEAK HEATING
HOURS OF THE DAY. THE CROSSWIND IMPACT DIAGRAM INDICATES SOME LOW
TO MODERATE CROSSWIND IMPACTS WITH THE CURRENT FORECAST...REDUCING
THE ACCEPTANCE RATE AT DFW AIRPORT.
THE PRIMARY THING TO WATCH THIS MORNING WILL BE HOW QUICKLY WE
HEAT UP AND MIX DOWN SOME OF THE STRONGER WINDS ALOFT TO THE
SURFACE. AREA VAD WIND PROFILES AND THE EARLY DATA COMING IN FROM
THE FWD RAOB INDICATE WESTERLY WINDS OF 35 TO 40 KTS IN THE 925 TO
850 MB LAYER. MODELS INDICATE THAT WINDS IN THIS LAYER WILL
DIMINISH BY LATE THIS MORNING...WHEN WE ARE LIKELY TO GET WARM
ENOUGH TO MIX INTO THIS LAYER. AS LONG AS THESE WINDS ALOFT
DIMINISH AS FORECAST...THE CURRENT FORECAST IS IN GOOD SHAPE. IF
WE HEAT UP QUICKER THAN EXPECTED...OR IF MODELS ARE SIMPLY TOO
AGGRESSIVE IN DIMINISHING THE STRENGTH OF WINDS ALOFT...WE MAY SEE
SOME GUSTS TO 25-27 KTS LATE THIS MORNING. WE WILL BE KEEPING A
CLOSE EYE ON AIRCRAFT RAOBS THIS MORNING AND WILL ADJUST TAFS ASAP
IF IT LOOKS LIKE THE CURRENT FORECAST IS UNDER FORECASTING THE
STRENGTH OF CROSSWINDS.
OTHERWISE...WITH DRY AIR IN PLACE...VFR CONDITIONS ARE EXPECTED
OVER THE NEXT 24-36 HOURS.
CAVANAUGH
&&
.PREV DISCUSSION... /ISSUED 354 AM CST MON DEC 15 2014/
UPPER LOW OVER CENTRAL KANSAS IS QUITE EVIDENT IN UPPER AIR
OBSERVATIONS AND SATELLITE DATA. THE LAST GASP OF STORMS FOR NORTH
AND CENTRAL TEXAS CONTINUES TO MARCH EASTWARD AND SHOULD CLEAR OUR
AREA BY MID MORNING OR SO. AT 08Z...THE LINE WAS LOCATED FROM JUST
EAST OF PARIS...TO CEDAR CREEK RESERVOIR...TO WACO. BEHIND THIS
LINE...DRIER AIR WILL FILTER IN AT THE SURFACE AND ALOFT...LEAVING
SUNSHINE AND WARM TEMPERATURES.
AS THE UPPER LOW MOVES NORTHEAST...THE COOLER AIR IN THE CENTRAL
PLAINS WILL FINALLY HAVE A CHANCE TO MOVE INTO NORTH TEXAS. THE
COOLER AIR WILL TAKE ANOTHER DAY TO MOVE SOUTH...LEAVING MOST OF
US WITH HIGHS IN THE 60S TODAY. TEMPERATURES DROP A BIT ON TUESDAY
THANKS TO THE COOLER AIR FILTERING IN...AND THANKS TO DRIER AIR
ALLOWING OVERNIGHT LOWS TO DROP TO MID DECEMBER NORMALS. THE NEXT
SHOT OF RAINFALL COMES BACK ON WEDNESDAY AS THE NEXT WAVE MOVES IN
FROM THE WEST AND ISENTROPIC LIFT INCREASES FROM THE SOUTH. RAIN
CHANCES REMAIN ON THURSDAY.
AFTER THURSDAY...THE WATERS ARE MUDDY. THE GFS AND ECMWF ARE
CONSISTENT WITH EACH OTHER THROUGH THURSDAY BEFORE DIVERGING
WIDELY FOR FRIDAY AND SATURDAY. BOTH MODELS AGREE IN A SHORT WAVE
TROUGH SOMEWHERE IN THE SOUTH CENTRAL PLAINS ON FRIDAY AND
SATURDAY. BOTH SOLUTIONS HAVE THE SHORT WAVE TROUGH DEEPENING INTO
A CLOSED LOW ON SATURDAY AS THE SYSTEM MOVES NORTHEAST.
THE FINER DETAILS OF THESE FEATURES WILL BE CRITICAL FOR OUR
WEATHER. BY 12Z FRIDAY...THE EURO DEPICTS THE STORM WILL BE CENTERED
SOMEWHERE NEAR DEL RIO WHILE THE GFS HAS THE STORM NEAR CHILDRESS.
BY 00Z SATURDAY...THE EURO MOVES THE UPPER LOW TO NEAR LUFKIN...AND
THE GFS MOVES THE STORM TO NEAR MUSKOGEE.
BEING FOUR TO FIVE DAYS AWAY... AND SEEING THE SYSTEM OFF OF THE ALEUTIAN
ISLANDS EARLY THIS MORNING...DO NOT WANT TO GET TOO CUTE WITH THE
DETAILS. HAVE LEANED CLOSER TO THE ECMWF SOLUTION AND AM UNDERCUTTING
GUIDANCE BY SEVERAL DEGREES IN THE EXTENDED PERIODS. BOTH THE ECMWF
AND GFS ENSEMBLES SUGGEST LOWER THAN NORMAL 500MB HEIGHTS WOULD BE
FARTHER SOUTH. DESPITE THE BIG DIFFERENCE IN THE FEATURES...EACH
SOLUTION HAS RELATIVELY HIGH POPS FOR THIS TIME FRAME...SO COLD
RAIN LOOKS QUITE POSSIBLE FOR FRIDAY. WE REMAIN IN A PROGRESSIVE
PATTERN...SO THIS FEATURE QUICKLY MOVES EAST LEAVING THE REMAINDER
OF NEXT WEEKEND DRY.
FOX
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 65 38 53 40 50 / 0 0 5 5 50
WACO, TX 68 39 56 41 51 / 0 0 5 10 50
PARIS, TX 63 37 51 35 47 / 5 5 5 10 50
DENTON, TX 63 36 52 36 47 / 0 0 5 5 50
MCKINNEY, TX 63 36 52 36 49 / 0 0 5 5 50
DALLAS, TX 65 39 53 40 50 / 0 0 5 5 50
TERRELL, TX 65 39 52 38 50 / 5 0 5 5 50
CORSICANA, TX 67 40 56 40 52 / 5 0 5 5 50
TEMPLE, TX 68 39 58 43 52 / 0 0 5 10 50
MINERAL WELLS, TX 63 35 54 39 48 / 0 0 5 5 50
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
79/30
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)