Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/17/14
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 CHICAGO/ROMEOVILLE IL
909 PM CST TUE DEC 16 2014
.SHORT TERM...
313 PM CST
TONIGHT THROUGH FRIDAY...
FILLING SURFACE LOW WAS OFF TO OUR EAST ACROSS THE CENTRAL GREAT
LAKES THIS AFTERNOON...BENEATH WEAKENING UPPER LEVEL LOW WHICH IS IN
THE PROCESS OF MERGING WITH STRONG DIGGING SHORT WAVE OVER THE UPPER
MISSISSIPPI VALLEY. THIS SECOND WAVE IS PROGGED TO SHEAR SOUTHEAST
ACROSS THE REGION TO THE EAST-SOUTHEAST AS IT REDEVELOPS INTO
REMNANT UPPER TROUGH TO THE EAST. VISIBLE SATELLITE IMAGERY SHOWS
MOST OF THE DEEPER CLOUD COVER HAS MOVED OFF TO THE EAST OF THE
FORECAST AREA...ALONG WITH THE BRUNT OF THE RADAR DETECTABLE
PRECIPITATION. EXPECT SOME PATCHY LIGHT RAIN/DRIZZLE AND PERHAPS A
FEW WET FLURRIES TO GRADUALLY END ACROSS THE AREA OVER THE NEXT FEW
HOURS AS MID-LEVELS CONTINUE TO DRY OUT...WITH 12Z RAOBS FROM
UPSTREAM LOCATIONS SUCH AS ABR AND OAX INDICATIVE OF MUCH DRIER AIR
ABOVE THE BOUNDARY LAYER. OTHERWISE...BLUSTERY WEST-NORTHWEST WINDS
WILL CONTINUE TO PULL COLDER AND DRIER AIR INTO THE AREA TONIGHT
WITH WINDS SLOW TO DIMINISH DUE TO LINGERING SURFACE TROUGHING
ACROSS THE UPPER MIDWEST. THOUGH REMAINING MOISTURE WILL BE SHALLOW
IT APPEARS CLOUD COVER WILL LINGER AT LEAST INTO EARLY WEDNESDAY
BEFORE STRONGER SUBSIDENCE CAN ERODE AND SCATTER CLOUDS MORE
EFFECTIVELY. DESPITE CLOUDS...UPSTREAM TEMPS ACROSS EASTERN IA ARE
ONLY IN THE LOW TO MID 20S AT THIS HOUR...SETTING THE STAGE FOR
CHILLIER TEMPS TONIGHT.
SHEARED MID-LEVEL VORTICITY AXIS FROM SHEARING UPPER MIDWEST SHORT
WAVE REMAINS OVER AREA WEDNESDAY..THOUGH HEIGHT RISES DO DEVELOP AS
THE NEW UPPER LOW DEEPENS OVER NEW ENGLAND. THIS ALLOWS THE GRADIENT
TO WEAKEN MORE QUICKLY ESPECIALLY DURING THE AFTERNOON AND
CONTINUING WEDNESDAY NIGHT AS SURFACE HIGH PRESSURE RIDGE MOVES
SLOWLY INTO WESTERN AND CENTRAL ILLINOIS. GUIDANCE DOES DEPICT A
SHORT WAVE APPROACHING FROM THE SOUTHERN PLAINS/LOWER MISSOURI
VALLEY AREA WEDNESDAY NIGHT...THOUGH THIS WAVE DAMPENS SIGNIFICANTLY
AS IT MOVES INTO THE UPPER RIDGE ACROSS THE MIDWEST. MODEL FORECAST
SOUNDINGS AND TIME-HEIGHT PLOTS INDICATE INCREASING MID-HIGH LEVEL
MOISTURE MAINLY AFTER MIDNIGHT WEDNESDAY NIGHT ACROSS OUR SOUTHWEST.
GUIDANCE (NAM...GFS...ECMWF AND SREF) DOES PRODUCE SOME LIGHT QPF
ACROSS CENTRAL ILLINOIS THURSDAY AS THIS WAVE CONTINUES TO
DEAMPLIFY...THOUGH FORECAST SOUNDINGS INDICATE LOW LEVELS INITIALLY
DRY AND SATURATION APPEARS INCOMPLETE MAKING PRECIP AT THE SURFACE A
LOW PROBABILITY. WEAKENING SURFACE HIGH PRESSURE RIDGE EVENTUALLY
MOVES INTO THE AREA THURSDAY NIGHT AND FRIDAY...ROUNDING OUT A FEW
DAYS OF MAINLY DRY AND SEASONABLY COOLER DAYS.
RATZER
&&
.LONG TERM...
313 PM CST
SATURDAY THROUGH TUESDAY...
ATTENTION TURNS TO A PAIR OF APPROACHING SHORT WAVE TROUGHS IN A
SOMEWHAT SPLIT FLOW REGIME. GUIDANCE HAS TRENDED WEAKER WITH THE
SOUTHERN STREAM DISTURBANCE...WHICH MOVES OUT ACROSS THE SOUTHERN
PLAINS AND GULF COAST STATES THROUGH SATURDAY. DECENT AGREEMENT IN
MODEL SOLUTIONS OF A MORE DIGGING NORTHERN STREAM WAVE COMING OUT OF
THE NORTHERN ROCKIES FRIDAY AND MOVING INTO THE LOWER MISSOURI AND
LOWER OHIO VALLEYS ON SATURDAY. WHILE MAIN SURFACE LOW PRESSURE
DEVELOPS WITH SOUTHERN SYSTEM ALONG THE GULF COAST...NORTHERN STREAM
FORCING DOES INDUCE AN INVERTED TROUGH INTO THE OHIO VALLEY SATURDAY
WHICH CONTINUES TO SUPPORT THE POTENTIAL FOR SOME LIGHT SNOW FROM
SOUTHERN/CENTRAL ILLINOIS INTO NORTHERN INDIANA...POSSIBLY INCLUDING
THE SOUTHEASTERN PART OF OUR CWA AS THE UPPER TROUGH MOVES OVERHEAD.
GUIDANCE STILL FOCUSES GREATER QPF SOUTHEAST OF THE FORECAST AREA...
BUT PRUDENT TO MAINTAIN SLIGHT CHANCES FOR SOME LIGHT ACCUMULATING
SNOW SOUTHEAST OF ABOUT A PONTIAC-VALPARAISO LINE. SURFACE HIGH
PRESSURE RIDGING QUICKLY BUILDS IN BEHIND THIS SYSTEM SATURDAY NIGHT
INTO SUNDAY. TEMPS DO MODERATE TO NORMAL FOR THE WEEKEND...GENERALLY
MID 20S AT NIGHT TO LOW/MID 30S BY DAY.
12Z GFS AND ECMWF RUNS HAVE COME INTO GOOD AGREEMENT IN BRINGING A
MORE AMPLIFIED UPPER TROUGH INTO THE CENTRAL CONUS SUNDAY NIGHT
THROUGH TUESDAY...WITH A STRONGER EMBEDDED SHORT WAVE MOVING ACROSS
THE UPPER MIDWEST LATE MONDAY-TUESDAY WITH DEEPENING LOW PRESSURE
PASSING TO OUR NORTH. THIS RESULTS IN WARMING TEMPERATURES ON
STRENGTHENING SOUTH WINDS...WITH THE POTENTIAL OF RAIN/SNOW CHANGING
TO RAIN BY LATE MONDAY AND CONTINUING TUESDAY AHEAD OF THE
APPROACHING COLD FRONT AS THE LOW MOVES ACROSS THE NORTHERN LAKES.
SOME DETAIL AND SPEED DIFFERENCES DO EXIST BETWEEN MODELS AND MUCH
COULD CHANGE BETWEEN NOW AND MONDAY...THOUGH IT DOES APPEAR THAT
COLDER AIR WOULD SPREAD INTO THE REGION LATER TUESDAY/TUESDAY NIGHT
WITH PRECIPITATION TAPERING OFF AS IT MIXES/CHANGES TO LIGHT SNOW.
COLDER AIR WOULD THEN ARRIVE IN TIME FOR THE CHRISTMAS HOLIDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
*NONE.
KJB
//DISCUSSION...UPDATED 00Z...
GUSTY WEST-NORTHWESTERLY WINDS WILL CONTINUE INTO TONIGHT AS SURFACE
LOW PRESSURE CONTINUES TO SHIFT OVER THE EASTERN GREAT LAKES REGION.
WIND SPEEDS SHOULD BEGIN TO ABATE LATER TONIGHT INTO WEDNESDAY AS A
SURFACE RIDGE OF HIGH PRESSURE BEGINS TO BUILD ACROSS THE REGION.
CIGS ACROSS THE AREA SHOULD ALSO BE ON AN IMPROVING TREND INTO
WEDNESDAY...WITH CLOUD COVER EVEN POSSIBLY BREAKING UP BY
AFTERNOON.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH WITH ALL ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
* THURSDAY THROUGH MONDAY...DRY/VFR.
KJB
&&
.MARINE...
130 PM CST
LOW PRESSURE AND A COLD FRONT HAVE PASSES EAST OF LAKE MICHIGAN AND
WINDS HAVE SHIFTED NORTHWESTERLY. STRONG COLD ADVECTION AND STRONG
PRESSURE RISES AS THE LOW PULLS AWAY TO THE EAST AND HIGH PRESSURE
BUILDS ACROSS THE NORTHERN PLAINS WILL COMBINE TO DRIVE WINDS TO
30KT FOR THE REMAINDER OF THE AFTERNOON THROUGH TONIGHT AND MUCH OF
TOMORROW. THERE IS THE POTENTIAL FOR A FEW GALE FORCE GUSTS...BUT
IN GENERAL...DO NOT EXPECT ENOUGH PREVAILING GALE FORCE WINDS TO
NECESSITATE A GALE WARNING. HOWEVER...A SMALL CRAFT ADVISORY HAS
ALREADY BEEN ISSUED FOR THE NEARSHORE WATERS AND EXPECT THAT TO PLAY
OUT AS CURRENTLY ADVERTISED. THE OVERALL PATTERN WILL BE SLOWLY
PROGRESSIVE...SO BRISK WINDS WILL REMAIN OVER THE LAKE THROUGH
THURSDAY...BUT AS HIGH PRESSURE BEGINS TO BUILD ACROSS THE WESTERN
GREAT LAKES...WINDS SHOULD DROP OFF AND BECOME MORE VARIABLE IN
DIRECTION. HIGH PRESSURE WILL PREVAIL ACROSS THE GREAT LAKES FROM
LATE THURSDAY THROUGH THE WEEKEND...KEEPING WINDS RELATIVELY LIGHT
IN SPEED AND VARIABLE IN DIRECTION. BY EARLY NEXT WEEK...THE HIGH
SHOULD FINALLY PUSH EAST OF LAKE MICHIGAN AS LOW PRESSURE BEGINS TO
DEVELOP OVER THE NORTHERN PLAINS. THIS SHOULD SET UP A PERIOD OF
INCREASING SOUTHERLY WINDS FOR EARLY NEXT WEEK AS A LOW PRESSURE
SYSTEM DEEPENS WHILE CROSSING THE NORTHERN PLAINS AND DRAGGING A
TRAILING COLD FRONT ACROSS THE CENTRAL PLAINS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 AM
WEDNESDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 10 AM THURSDAY.
&&
$$
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
901 PM CST Tue Dec 16 2014
.UPDATE...
ISSUED AT 901 PM CST TUE DEC 16 2014
Cloudy skies will continue overnight. Even with cooler and drier
air advecting into the area overnight, clouds should still keep
temps from dropping much overnight. Models still trying to bring
in some clearing during the early morning in western Illinois, but
with cyclonic flow, a deep layer of moisture, and an inversion,
believe clouds will hang around the area through late tomorrow.
Gradient will continue to loosen overnight, so gusts should
diminish later tonight, though wind speeds will still be 10-15kts
through early morning. so, current forecast looks good, so no
update needed at this time.
&&
.SHORT TERM...(Tonight)
ISSUED AT 230 PM CST TUE DEC 16 2014
Occluded low pressure system shifts into the eastern Great Lakes
this evening, allowing the gradient to gradually relax and decrease
wind gusts. Latest NAM forecast soundings and HRRR ceiling guidance
suggest lower clouds will persist overnight, and given deep cyclonic
flow and in-building subsidence inversion at 900 MB, believe this
will hold true. Therefore have increased cloud cover overnight.
Lows will be challenging with the full effect of CAA being offset by
insulating effects of cloud cover. Have trended mins 2-3 degrees
warmer than MET/MAV blend, which gives lower 20s west of the IL
River, to mid 20s central/east.
&&
.LONG TERM...(Wednesday through Tuesday)
ISSUED AT 230 PM CST TUE DEC 16 2014
High pressure to settle into the region on Wednesday bringing in dry
with more seasonal temperatures. Forecast soundings...although not
as aggressive as yesterday with the low level moisture...continues
to indicate moisture trapped beneath a subsidence inversion will
keep a bit more cloudiness around the area during the day. Soundings
do show some breaks developing by late morning into the afternoon
hours but just in time to see mid and high level moisture/clouds
stream in ahead of our next weather system for Thursday. That weather
system is expected to spread light snow into parts of extreme west
central through southeast Illinois Thursday morning. Model runs had
been suggesting as the precip spread northeast into a more confluent
flow pattern over the lower Great Lakes coverage would decrease
during the day Thursday. Most of the operational models have backed
off that idea for now and have brought some light precip further north
and east into our area on Thursday so have brought precip chances further
north into the forecast area. Snowfall could accumulate up to 1 inch
from Springfield south Thursday morning before the area begins to
decrease in coverage during the afternoon.
Thursday`s system should be off to our east by evening with our attention
turning to a more significant wave over eastern Texas that will push
a surface low east-northeast across the Gulf Coast states Friday. The
northern periphery of the precip associated with the southern wave will
track over southeast Illinois with once again light snowfall for later
Friday night into Saturday. Current indications suggest an inch or less
for southeast Illinois. High pressure will then shift east into our
area for Sunday into early Monday bringing quiet weather to the region.
Quite a bit of model spread with respect to the system for early next
week, which will be moving southeast out of the Northern Plains and
tracking a strong low pressure system at the surface to our north
Monday. The operational GFS is more progressive with the early week
system and sweeps the cold front thru our area Tuesday afternoon and
evening with little if any southern stream interaction showing up
on the latest model run. In contrast, the latest ECMWF was indicating
a more phased look between the northern and southern streams which
effectively holds up the front pushing across our area later Tuesday
until a surface wave shifts off to our northeast Tuesday night.
This would bring rain on Tuesday, which would eventually change to
snow later in the day and evening as the deepening surface wave shifts
away from our area by Wednesday.
Seems as if each model run has a different solution with respect to
the pattern over the Midwest the first half of next week so not making
any significant changes to the grids at this point for days 7 and 8.
After our brief warm up ahead of the system on Monday and Tuesday, it
turns colder again by midweek.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
ISSUED AT 536 PM CST TUE DEC 16 2014
With cyclonic flow remaining over the area for most of the TAF
period, believe MVFR clouds will remain over the area through the
period. Only hope seen in the models for any possible clearing is
at SPI and PIA late in the period, around 23z. Since that is near
the end, will not include at this time and will wait and see if
later model runs continue with the forecast. So only TAF issue is
winds. Winds will remain northwest through the period. Winds will
remain gusty at all sites except at SPI, but then loose the gusts
at PIA and DEC in next hour or two. BMI and CMI will see wind
speeds decrease, but will not loose gusts until after midnight.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Auten
SHORT TERM...25
LONG TERM...Smith
AVIATION...Auten
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.
&&
$$
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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
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
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WWW.TWITTER.COM/NWSINDIANAPOLIS
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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:
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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:
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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
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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
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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
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
544 PM CST TUE DEC 16 2014
.SHORT TERM /TONIGHT/...
ISSUED AT 330 PM CST TUE DEC 16 2014
MAIN CHALLENGES TONIGHT WILL BE CLOUD COVER AND TEMPERATURES.
BRIEF BREAK IN CLOUDS THIS AFTERNOON WEST AS NOSE OF COLD AIR
ADVECTION MOVED SOUTHEAST ACROSS THE REGION. AS THE LOWEST
PORTIONS OF THE BOUNDARY LAYER WARMED...CLOUDS AGAIN FORMED ON THE
TOPS OF THE THERMALS...THEN BACKFILLING TO SOME EXTENT ACROSS THE
REGION. TONIGHT...MAY SEE THE CLOUDS DISSIPATE BRIEFLY AS THE
PROCESS REVERSES WITH SUNSET AND AN AREA OF CLEARING MAY DEVELOP
ONCE AGAIN WEST/CENTRAL. CONFIDENCE ON HOW LONG OR HOW WIDESPREAD
ANY CLEARING WILL BE IS LOW...GIVEN THE TENDENCY FOR MORE STRATUS
TO REDEVELOP AS THE RIDGE WEST OF THE AREA BEGINS TO MOVE EAST
OVERNIGHT. THE OTHER FACTOR REGARDING CLOUD COVER IS A WEAK WAVE
OVER COLORADO THIS AFTERNOON...WHICH IS CAUSING A RETURN OF WARM
AIR ADVECTION OVER THE WESTERN PLAINS. THIS IS GENERATING AN AREA
OF MID LEVEL CLOUDS WHICH SHOULD BEGIN ADVECTING EAST OVER THE
H700 RIDGE TOWARD IOWA OVERNIGHT. CONSEQUENTLY...OVERNIGHT WILL
MOST LIKELY SEE A MIXTURE OF SOME CLEARING EARLY AND CLOUDS MOST
AREAS LATE INTO SUNRISE. WINDS ALOFT WILL CONTINUE TO DECOUPLE BY
EVENING AND LIGHTER NORTHWEST WINDS ARE EXPECTED TONIGHT.
TEMPERATURES WILL BE QUITE CHILLY...AND REGARDLESS OF THE CLOUD
COVER...THE PERSISTENT LOW LEVEL COLD AIR ADVECTION TODAY WILL
RESULT IN OVERNIGHT LOWS NEAR 5 FAR NORTHWEST TO NEAR 20 IN THE
SOUTH. FETCH OF COLD AIR SUGGESTS THE WEST/NORTHWEST WILL BE
COLDER DUE TO ADVECTION TODAY.
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
ISSUED AT 330 PM CST TUE DEC 16 2014
A PROGRESSIVE BUT RELATIVELY CALM WEATHER PATTERN WILL BE IN
PLACE OVER THE REGION THROUGH THE WEEKEND WITH WITH TWO MAIN
WEATHER SYSTEMS OF NOTE ON THURSDAY AND EARLY NEXT WEEK. THE
BEGINNING OF THE PERIOD WILL SEE AN INVERTED 500 MB TROUGH AND
ASSOCIATED PV ANOMALY SWING THROUGH THE UPPER MISSISSIPPI RIVER
VALLEY ON THE BACKSIDE OF A DEPARTING LOW. A SURFACE RIDGE AXIS
WILL ALSO LAY OUT ACROSS THE WESTERN PORTION OF THE STATE ON
WEDNESDAY WITH LIGHT NORTHERLY FLOW OVER THE CWA. THE BIGGEST
QUESTION FOR TOMORROW WILL BE THE EXTENT AND DURATION OF CLOUD
COVER. NAM 0.5-1 KM MOISTURE PROFILES KEEP STRATUS OVER THE
NORTHEAST THROUGH MUCH OF THE DAY TOMORROW AND LEANED TOWARDS THIS
GUIDANCE FOR SKY GRIDS...BUT GIVEN THE UNCERTAINTY IN ANY CLEAR
SLOT POSITIONING HAVE KEPT AT LEAST PARTLY CLOUDY WORDING
THROUGHOUT THE CWA.
LATE WEDNESDAY INTO THURSDAY MORNING WILL SEE A SHARP MID TO
UPPER LEVEL SHORTWAVE SHIFT OFF THE FRONT RANGE AND INTO THE
MISSOURI RIVER VALLEY. THE WAVE WEAKENS AS IT RUNS UP AGAINST THE
DOWNSTREAM RIDGE...BUT PORTIONS OF SOUTHERN IOWA SHOULD SEE
MEASURABLE SNOW THURSDAY MORNING. ALL MEDIUM RANGE SOLUTIONS PLACE
A NARROW BUT STRONG AREA OF DGZ FORCING BETWEEN 09Z AND 18Z ALONG
AND NORTH OF THE MISSOURI BORDER. HOWEVER...NAM SOUNDINGS ARE
NOTABLY DRIER IN THE DGZ COMPARED TO THE GFS AND EC. THE SYSTEM
WILL ALSO BE FIGHTING A WEDGE OF LOW-LEVEL DRY AIR THAT SHOULD
RESULT IN A SHARP PRECIP CUTOFF ALONG THE NORTHERN SIDE OF THE
LINE. FOR THE FORECAST PACKAGE...DID NOT CHANGE COVERAGE TOO MUCH
BUT INCREASED POPS TO HIGH CHANCES OVER THE SOUTH WITH THE
EXPECTATION OF THESE BEING UPPED TO LIKELIES OR CATEGORICAL ONCE
THE LOCATION OF THE GREATEST FORCING AND MOISTURE PROFILES ARE
BETTER RESOLVED. TOTAL SNOWFALL AMOUNTS LOOK TO BE AROUND OR LESS
THAN AN INCH GIVEN THE TRANSIENT NATURE OF THE SYSTEM AND INITIAL
SURFACE DRY LAYER.
FRIDAY AND INTO THE WEEKEND LOOK TO REMAIN DRY WITH WEAK SOUTHERLY
FLOW/WAA BRINGING HIGHS BACK ABOVE FREEZING. SATURDAY WILL SEE A
AN UPPER LEVEL TROUGH SWING THROUGH THE REGION...BUT FORECAST
SOUNDINGS REMAIN MOSTLY DRY AND CONFIDENCE WAS NOT HIGH ENOUGH TO
INTRODUCE POPS IN ANY GIVEN LOCATION. A FEW LIGHT SNOW SHOWERS ARE
CERTAINLY NOT OUT OF THE REALM OF POSSIBILITIES WITH THE PASSAGE
OF THIS SYSTEM.
HOWEVER...THE WEATHER PATTERN TAKES A MORE ACTIVE TURN EARLY NEXT
WEEK AS A LONGWAVE TROUGH DIGS OVER THE ROCKIES AND SLOWLY
MIGRATES EAST TOWARDS THE CWA BY THE END OF THE PERIOD. THE GFS
AND EC ARE IN SOMEWHAT GOOD AGREEMENT WITH THE RESULTANT SURFACE
CYCLONE AND TAKE IT ON A COURSE NORTH OF THE CWA...WITH IOWA
REMAINING IN THE WARM SECTOR AND SEEING A MIX OF RAIN AND SNOW
ALONG THE ATTENDANT WARM/COLD FRONTAL BOUNDARIES.
&&
.AVIATION...17/00Z
ISSUED AT 544 PM CST TUE DEC 16 2014
STATUS DECK CONTINUES ACROSS MUCH OF CENTRAL IOWA ALTHOUGH BOTH
RAP AND HRRR INDICATE THIS DECK WILL ERODE OVERNIGHT. WILL
CONTINUE WITH THE STATUS THROUGH THE EVENING BUT GO WITH SOME
GRADUAL CLEARING LATE TONIGHT AS SURFACE RIDGE APPROACHES. WINDS
WILL DIMINISH THIS EVENING AND REMAINING LIGHT TO MODERATE
OVERNIGHT INTO WEDNESDAY.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...REV
LONG TERM...SKOW
AVIATION...COGIL
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 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...UPDATED
NWS JACKSON KY
812 PM EST TUE DEC 16 2014
.UPDATE...
ISSUED AT 745 PM EST TUE DEC 16 2014
HOURLY GRIDS HAVE BEEN UPDATED BASED ON RADAR AND OBSERVATION TRENDS.
THIS LED TO LOWERING TEMPERATURES IN THE HIGHEST TERRAIN INITIALLY
ABOVE 2500 FEET. MODEL PLAN VIEW DATA ALSO SUGGESTED SLIGHTLY LOWER
MIN T IN THE HIGHER TERRAIN NEAR BLACK MTN. RAIN SHOWERS CONTINUE
ACROSS THE EASTERN PART OF THE CWA...WITH SOME DRIZZLE FURTHER TO THE
WEST. MODEL DATA SUGGESTS SUFFICIENT MOISTURE FOR DRIZZLE TO LINGER
THROUGH THE NIGHT AND INTO EARLY ON WED. THE HIGHEST TERRAIN SHOULD
COOL ENOUGH FOR CHANCES OF FREEZING DRIZZLE ABOVE 2000 FEET. THIS
THREAT WILL BEGIN FIRST...IN THE NEXT HOUR OR TWO ON TOP OF BLACK MTN
AND THEN GRADUALLY SPREAD TO PINE MOUNTAIN AND POSSIBLY THE LOG
MOUNTAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 315 PM EST TUE DEC 16 2014
19Z SFC ANALYSIS SHOWS A FAIRLY DEEP AREA OF LOW PRESSURE LIFTING
NORTHEAST THROUGH THE EASTERN GREAT LAKES. THE COLD FRONT ASSOCIATED
WITH THIS SYSTEM IS NOW THROUGH EASTERN KENTUCKY AND AS A RESULT
GUSTY WEST WINDS ARE BRINGING IN A COLDER AIR MASS. AS IT DOES SO...
IT IS ALSO GENERATING A SUBSTANTIAL AREA OF DRIZZLE AND LOWER CIGS.
TEMPERATURES VARY FROM THE LOW 40S WEST TO NEAR 50S EAST ACROSS THE
CWA WITH DEWPOINTS IN THE UPPER 30S TO LOWER 40S.
THE MODELS ARE IN DECENT ENOUGH AGREEMENT ALOFT THROUGH THE SHORT
TERM PORTION OF THE FORECAST AS THEY ALL DAMPEN OUT THE CURRENT
TROUGH OVER THE AREA WHILE ABSORBING IT INTO THE MAIN MID LEVEL LOW
OVER THE UPPER MIDWEST. THIS WILL KEEP FAST...WEST TO EAST...FLOW
ABOVE EASTERN KENTUCKY INTO THE DAY WEDNESDAY...THOUGH MODEL
DIFFERENCES START TO MAGNIFY BY DAWN. THE ECMWF IS SLOWER MOVING
THIS MIDWEST LOW EAST COMPARED TO THE GEM AND GFS WHICH WILL ALSO
SERVE TO KEEP OUR HEIGHTS SLIGHTLY SUPPRESSED INTO WEDNESDAY EVENING.
DESPITE THIS...THE PREFERRED ECMWF DOES NOT LAG IN BRINGING THE NEXT
BATCH OF ENERGY INTO THE REGION FROM A QUICK MOVING WAVE PASSING OUT
OF THE SOUTHERN PLAINS. THIS WILL SEEP INTO OUR SOUTHWEST PARTS BY
THURSDAY MORNING. FOR THE FORECAST...FOLLOWED A BLEND OF THE HIGHER
RESOLUTION HRRR AND NAM12 WITH SOME ADJUSTMENT TOWARD THE MAIN
FEATURES IN THE LATEST ECMWF.
A DREARY EVENING AND OVERNIGHT IS ANTICIPATED THROUGH EASTERN
KENTUCKY AS LOW CIGS AND DRIZZLE WILL DOMINATE UNDER A SUBSIDENCE
INVERSION...PARTICULARLY OVER THE NORTHERN HALF THE CWA. THERE IS A
CONCERN THAT THE HIGHER POINTS OF EASTERN KENTUCKY FALL TO
FREEZING...OR A COUPLE OF DEGREES BELOW...BY DAWN GIVEN THE CAA
OVERNIGHT. COMBINED WITH THE AREAS OF DRIZZLE STILL AROUND...THERE
WILL BE A THREAT OF FREEZING DRIZZLE GENERALLY ABOVE 2000 FEET. FOR
THIS...WILL ISSUE AN SPS FROM LATE TONIGHT INTO THURSDAY MORNING FOR
OUR SOUTHEASTERN-MOST COUNTIES WITH THAT HIGHER TERRAIN. THE LOW
CLOUDS WILL PROBABLY HOLD TOUGH INTO THE FIRST PART OF THE DAY
WEDNESDAY BUT THERE COULD BE SOME BREAKUP MAKING FOR A BRIEF PERIOD
OF SUNSHINE DURING THE AFTERNOON AHEAD OF THE NEXT BATCH OF HIGHER
CLOUDS DUE IN HERE LATER THAT EVENING. THESE NEXT CLOUDS WILL QUICKLY
INCREASE AND LOWER THROUGH THE NIGHT WITH EVEN SOME LIGHT RAIN OR
SNOW POSSIBLE BY DAWN THURSDAY...THOUGH TEMPERATURES WILL BE MILDER
THAN TONIGHT IN MOST PLACES.
USED THE BCCONSSHORT AS A STARTING POINT FOR THE T/TD/WIND GRIDS FOR
THE FIRST 20 HOURS BEFORE POPULATING WITH THE SUPERBLEND THEREAFTER.
THESE WERE THEN SUBJECTED TO MINOR ADJUSTMENTS FOR TERRAIN EFFECTS
MAINLY TONIGHT AND WEDNESDAY NIGHT. AS FOR POPS...ENDED UP JUST ABOVE
THE HIGHER MET MOS GUIDANCE TONIGHT GIVEN THE LOW QPF BUT MODERATE
POPS WITH EXTRA EMPHASIS ON DRIZZLE AS PTYPE. ALSO...FOR LATE
WEDNESDAY WENT A BIT HIGHER THEN GUIDANCE IN THE SOUTHWEST GIVEN THE
FAST FLOW REGIME.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 245 PM EST TUE DEC 16 2014
PROGRESSIVE PATTERN WILL CONTINUE THROUGH THE EXTENDED. THE PERIOD
WILL START AS A MID LEVEL TROUGH CROSSES INTO THE OHIO RIVER VALLEY
ON THURSDAY. MODELS HAVE TRENDED MORE AGGRESSIVE WITH THIS FEATURE
WITH THE 12Z SUITE OF MODELS WITH GFS EVEN SHOWING SOME MODEST LIFT
ABOVE 850MB. THE MAIN LIMITING FACTOR FOR PRECIPITATION ON THURSDAY
WILL BE THE LOW LEVEL DRY AIR. HOWEVER...GIVEN THE DEEP MOISTURE
STARTING AROUND 5KFT...THIS SHOULD BE ENOUGH TO AT LEAST WARRANT A
CHANCE OF MEASURABLE PRECIPITATION REACHING THE GROUND.
HOWEVER...THIS PRECIPITATION MAY DRY UP AS IT TRIES TO PUSH
NORTHWARD THROUGH THE DAY. THUS...PLAN TO GO WITH CHANCE POPS ACROSS
THE SOUTH...TRAILING OFF TO SLIGHT CHANCE IN THE NORTH. ALL OF THIS
PRECIPITATION AS EXPECTED WILL REMAIN LIGHT...BUT SOME SNOWFLAKES
COULD MIX IN AT TIMES THROUGH THE DAY. HIGH PRESSURE WILL PROVIDE
DRY WEATHER THURSDAY NIGHT THROUGH FRIDAY.
THE WEATHER TURNS MORE INTERESTING BY FRIDAY NIGHT THROUGH SATURDAY
AS A SOUTHERN STREAM SHORTWAVE PUSHES EAST ACROSS THE SOUTHERN TIER
OF THE US. THIS SYSTEM IS NOT EXPECTED TO GET MUCH HELP FROM THE
NORTHERN STREAM...AND THUS...NOT MUCH COLD AIR IS EXPECTED TO GET
WORKED INTO THIS SYSTEM. THIS FACT...COMBINED WITH A WEAKENING AREA
OF LOW PRESSURE TRACKING ACROSS THE GULF COAST STATES WILL LIKELY
YIELD VERY LITTLE SNOW POTENTIAL. HOWEVER...WE ARE ON THE NORTH SIDE
OF THIS SYSTEM...WHICH WOULD BE THE BEST SPOT FOR ANY SNOW.
PRECIPITATION IS EXPECTED TO SPREAD INTO THE AREA LATE FRIDAY NIGHT
AND CONTINUE THROUGH SATURDAY. BEST SNOW POTENTIAL MAY BE AT THE
ONSET FRIDAY NIGHT...BUT AGAIN...PRECIPITATION RATES MAY BE FAIRLY
LIMITED...KEEPING SNOW AMOUNTS FROM BEING ALL THAT HIGH. IN
FACT...WE COULD SEE A MIX OF RAIN/SNOW RIGHT THROUGH SATURDAY WITH
VERY LITTLE SNOW ACCUMULATION FOR MUCH OF THE AREA. THE ECMWF
REMAINS THE COLDER OF THE MODELS SUGGESTING BETTER SNOW
POTENTIAL...WHILE THE GFS HAS MAINTAINED ITS ALL RAIN FORECAST.
GOING WITH A COMPROMISE ON HIGHS ON SATURDAY WOULD BE TEMPERATURES
AROUND 40 BY THE AFTERNOON ACROSS MUCH OF THE AREA. ITS POSSIBLE
SOME COOLER READINGS IN THE 30S COULD KEEP MORE SNOW GOING A BIT
LONGER ACROSS THE NORTHERN PORTION OF THE AREA...BUT WITH WEAK
PRECIP RATES...COMBINED WITH ABOVE FREEZING TEMPERATURES...SHOULD
REALLY CUT INTO ANY SNOWFALL POTENTIAL EVEN WITH THE COLDER ECMWF
SOLUTION. PRECIPITATION WILL WIND DOWN BY SATURDAY NIGHT GOING OVER
TO A PERIOD OF LIKELY DRIZZLE.
DRY WEATHER WILL RETURN FOR SUNDAY AND PERSIST INTO THE EARLY PART
OF NEXT WEEK. TEMPERATURES ARE EXPECTED TO REMAIN FAIRLY SEASONABLE
THROUGH THE END OF THE FORECAST PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 735 PM EST TUE DEC 16 2014
RAIN SHOWERS WILL GRADUALLY TAPER TO DRIZZLE DURING THE FIRST 6 HOURS
OF THE PERIOD NEAR...WHILE AREAS OF DRIZZLE ARE ANTICIPATED FURTHER
TO THE WEST. IN FACT...FORECAST SOUNDINGS AND TIME HEIGHTS CONTINUE
TO INDICATE A STRONG SUBSIDENCE INVERSION BEHIND THE FRONT...WITH LOW
LEVEL MOISTURE TRAPPED INTO AT LEAST THE 12Z TO 18Z PERIOD. THIS
WILL LEAD TO LOWERING CIGS LIKELY DOWN INTO THE IFR RANGE AT ALL TAF
STIES AT TIMES...WITH THE DRIZZLE POTENTIAL LINGERING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...JP
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 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 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
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 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...UPDATED
NWS BILLINGS MT
850 PM MST TUE DEC 16 2014
.UPDATE...
SPOTTER AND SHERIFF/S OFFICE REPORTS AS OF MID EVENING SUGGEST FOG
IS NOT PARTICULARLY DENSE EXCEPT WHERE LOW CEILINGS ARE MEETING UP
WITH HIGHER RIDGETOPS. THAT EXPLAINS THE REPORTS WE/VE RECEIVED OF
1/2 TO 1/4SM VISIBILITY BOTH NEAR THE BULL MOUNTAINS AND MOLT. THE
HRRR SUGGESTS THAT IF MORE WIDESPREAD DENSE FOG OCCURS IT COULD BE
ALONG A LINE FROM ABOUT BILLINGS TO HARDIN AND SHERIDAN AFTER MID-
NIGHT...BUT CONFIDENCE IS NOT HIGH AND IN THE MEANTIME THERE ISN/T
ANY EVIDENCE IN OBSERVATIONS AND REPORTS THAT A DENSE FOG ADVISORY
IS NEEDED RIGHT NOW. THE AREAS OF FOG MENTIONED IN THE FORECAST IS
LIKELY THE BEST WAY OF HANDLING THE SITUATION RIGHT NOW. WE DID GO
AHEAD AND EXTEND A MENTION OF PATCHY FOG INTO WEDNESDAY MORNING IN
THE ROUNDUP...HYSHAM...LAME DEER....BROADUS AND EKALAKA AREAS WITH
RECENT HRRR SOLUTIONS IN MIND.
OTHERWISE...THE GOING FORECAST /INCLUDING OUR EARLIER UPDATE WHICH
INVOLVED POPS IN PARTS OF SOUTH CENTRAL MT/ IS ON TRACK AND SO THE
FORECAST ONLY NEEDED MINOR CHANGES WITH THIS UPDATE. SCHULTZ
&&
.SHORT TERM...VALID FOR WED AND THU...
AREAS OF FOG STILL PERSISTING ACROSS PORTIONS OF SC/SE MT THIS
AFTERNOON. MOIST UPSLOPE FLOW OF AIR WITH LIGHT WINDS ALOFT IS
ALLOWING FOG TO CONTINUE OVER THE AREA. VISIBILITY HAS BEEN
IMPROVING OVER OUR WESTERN ZONES LATE THIS AFTERNOON AS A WEAK
DISTURBANCE MOVES TOWARD OUR REGION AND IS SPREADING MID LEVEL
CLOUD DECK ACROSS THE AREA. WILL GO AHEAD AND DROP THE DENSE FOG
ADVISORY FOR OUR WESTERN ZONES WITH IMPROVING VISIBILITIES. HRRR
IS SHOWING MOIST UPSLOPE FLOW TO CONTINUE OVERNIGHT AND FOG WILL
AGAIN BE POSSIBLE OVER MUCH OF OUR FORECAST AREA. MOISTURE NOT
AS DEEP AS THE PREVIOUS NIGHT AND DO NOT EXPECT WIDESPREAD FOG
WITH VISIBILITY BELOW A 1/2 MILE.
UPPER WAVE WILL DRIFT SLOWLY ACROSS THE AREA WEDNESDAY AS 300 MB
JET STAYS WELL SOUTH OF US. WEAK QG FORCING WITH THIS WAVE WILL
BRING SOME LIGHT SNOW TO THE PLAINS TOMORROW BUT NO SNOW
ACCUMULATIONS ARE EXPECTED. DRY WEATHER RETURNING TO THE PLAINS
WEDNESDAY NIGHT THROUGH THURSDAY AS WEAK SHORT WAVE RIDGING
MOVES ACROSS THE REGION. SOME MOUNTAIN SNOW SHOWERS WILL CONTINUE
THROUGH THIS PERIOD BUT AMOUNTS WILL BE LIGHT. WITH INCREASING
HEIGHTS WEDNESDAY AND THURSDAY...TEMPERATURES WILL CLIMB BACK TO
NEAR SEASONAL NORMALS. RICHMOND
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
MODELS CONTINUE TO INCREASE CONFIDENCE IN THE EXTENDED. BOTH THE
OPERATIONAL GFS AND ECMWF GENERALLY FIT WITHIN THE SPREAD OF THE
ENSEMBLE DATA. WEAK PACIFIC RIDGE WILL MOVE IN TO THE STATE
FRIDAY. SATURDAY ANOTHER SHORTWAVE WILL MOVE THROUGH...AS THE FLOW
INCREASES AND BECOMES MORE NORTHWESTERLY. PRECIP CHANCES WILL
INCREASE IN THE MOUNTAINS.
SUNDAY WILL SEE SOME LEESIDE TROUGHING DEVELOP. WINDS WILL PICKUP
AROUND NYE AND LIVINGSTON AS THE PRESSURE GRADIENT TIGHTENS DURING
THE DAY SUNDAY. WINDS WILL BEGIN TO INCREASE SUNDAY NIGHT TO AROUND
BILLINGS. FOR MONDAY...IT STILL LOOKS LIKE A COLD FRONT WILL MOVE
THROUGH AS A SURFACE LOW DROPS OUT OF CANADA...BRING PRECIP TO
MUCH OF THE AREA. AS WITH THE PREVIOUS FORECAST...MODELS CONTINUE
TO DEVELOP AN ATMOSPHERIC RIVER...GIVING THE AREA PLENTY OF
MOISTURE. WITH THIS STILL A LONG WAY OFF...HAVE OPTED TO CONTINUE
SIMILAR POPS TO THE PREVIOUS FORECAST. GIVEN THAT TEMPERATURES
WILL STILL BE WARM...LOOKS LIKE MUCH OF THE CENTRAL ZONES WILL
SEE RAIN THAT WILL SWITCH TO SNOW AS TEMPERATURES DROP MONDAY
NIGHT. REIMER
&&
.AVIATION...
PERSISTENT LOW CIGS WILL KEEP FLIGHT CONDITIONS SUB-VFR IN ALL
LOCATIONS...WITH AS LOW AS VLIFR IN SOME LOCATIONS OVERNIGHT.
AREAS OF FOG ARE AGAIN POSSIBLE ACROSS THE REGION OVERNIGHT...AS
WELL AS SNOW OVER AREA MOUNTAINS AND NEAR FOOTHILLS REGIONS.
WIDESPREAD MOUNTAIN OBSCURATIONS ARE EXPECTED THROUGH THE NIGHT.
FLIGHT CONDITIONS ARE EXPECTED TO IMPROVE THROUGH THE DAY
WEDNESDAY. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
WED THU FRI SAT SUN MON TUE
-----------------------------------------------------------
BIL 020/036 022/039 023/038 027/042 026/044 035/047 030/041
11/E 01/B 10/U 11/B 13/W 34/W 33/W
LVM 022/040 023/042 023/040 026/043 026/044 036/047 030/043
42/J 11/E 11/B 11/N 13/W 33/W 33/W
HDN 014/032 015/037 016/037 020/040 019/041 029/044 026/040
01/E 01/B 10/U 01/B 12/W 33/W 33/W
MLS 014/029 016/036 019/037 019/039 022/041 030/043 026/039
11/E 01/B 10/U 01/B 11/B 33/W 32/W
4BQ 014/030 016/040 018/040 017/041 020/043 030/045 027/041
02/J 01/B 11/B 00/B 11/B 33/W 32/W
BHK 011/025 015/035 019/037 017/039 020/040 027/041 024/037
02/J 11/B 11/B 01/U 01/B 33/W 22/J
SHR 015/038 015/038 016/038 019/040 019/041 028/043 025/040
01/B 01/B 10/U 01/B 12/J 34/W 43/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
528 PM CST TUE DEC 16 2014
.SYNOPSIS...
ISSUED AT 310 PM CST TUE DEC 16 2014
AN ACTIVE H5 PATTERN CONTINUES ACROSS THE CONUS THIS
MORNING. LOW PRESSURE WAS LOCATED NEAR CHICAGO WITH A SECONDARY
UPSTREAM SHORTWAVE NOTED OVER EASTERN ND. HT FALLS OF 50 TO 150
METERS EXTENDED FROM NRN MINNESOTA...SE INTO OHIO AND THE MID
ATLANTIC STATES. FURTHER WEST...RIDGING EXTENDED ACROSS THE ROCKIES
NWD INTO SASKATCHEWAN AND ALBERTA IN CANADA. FURTHER WEST...A
TROUGH OF LOW PRESSURE EXTENDED FROM THE GULF OF ALASKA...SOUTH
ALONG THE WEST COAST OF CANADA AND THE UNITED STATES. AT THE
SURFACE...HIGH PRESSURE EXTENDED ACROSS THE CENTRAL PLAINS FROM
NORTH DAKOTA...SWD INTO TEXAS. OVER SNOW COVERED AREAS OF
NEBRASKA...LOW CLOUDS WERE PRESENT. AS OF THE EARLY AFTERNOON
HOURS...SOME OF THIS LOW CLOUDINESS WAS BEGINNING TO BURN OFF ACROSS
SOUTHERN NEBRASKA. ELSEWHERE...UNDER CLOUDY TO MOSTLY CLOUDY
SKIES...3 PM TEMPERATURES RANGED FROM 21 AT AINSWORTH...ONEILL AND
THEDFORD TO 24 AT NORTH PLATTE.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 310 PM CST TUE DEC 16 2014
STRATUS AND SNOW PACK WILL CONTINUE TO LIMIT THE DIURNAL SWING OF
TEMPERATURES. UPPER LEVEL RIDGING OVERHEAD OVERNIGHT INTO
TOMORROW...HOWEVER MOISTURE IS TRAPPED IN THE BOUNDARY LAYER AND
WILL LEAD TO STRATUS. THIS CLOUD COVER WILL OVERCOME THE SNOW PACK
AND ACT TO KEEP TEMPS FROM COOLING OFF VERY FAR OVERNIGHT. HAD SOME
FOG ACROSS THE PANHANDLE INTO FAR SW NEB THIS MORNING AND WITHOUT
ANY MIXING OUT OF THE BL...EXPECT IT TO RETURN. SOME UNCERTAINTY ON
HOW FAR EAST IT WILL MAKE IT. THIS MORNING THE EASTWARD PUSH WAS
LIMITED HOWEVER EXPECT THE POCKET OF PARTIAL CLEARING ACROSS SW NEB
WILL ADD A LITTLE MOISTURE /MELTING SNOW/ TO THE BL AND FAVOR MOVE
DEVELOPMENT FURTHER EAST ACROSS SW NEB. GUIDANCE DOES NOT SUGGEST
WIDESPREAD FOG...SO ONLY INCLUDED PATCHY WORDING FOR NOW. AS FOR
OVERNIGHT TEMPERATURES EXPECT THE CLOUDS TO KEEP TEMPS UP...AND
FORECAST IS ABOVE GOING GUIDANCE. TOMORROW HIGHS AGAIN IN THE 20S AS
CLOUDS AND SNOW PACK WORK TO KEEP TEMPS FROM MOVING MUCH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 310 PM CST TUE DEC 16 2014
MID RANGE...WEDNESDAY NIGHT THROUGH FRIDAY...IN THE MID
RANGE...PRECIPITATION CHANCES WEDNESDAY NIGHT...ALONG WITH
TEMPERATURES FOR THURSDAY AND FRIDAY ARE THE MAIN FORECAST CONCERNS.
FOR WEDNESDAY NIGHT...A LEAD UPPER LEVEL DISTURBANCE WILL LIFT
ACROSS THE CENTRAL ROCKIES...AND WILL CROSS KANSAS AND SRN NEBRASKA
WEDS NIGHT. CROSS SECTIONS TAKEN ACROSS SWRN NEBRASKA INDICATE SOME
WEAK LIFT IN THE H700 TO H600 LAYER ACROSS SWRN NEBRASKA WEDS
EVENING...WHICH COINCIDES WITH PLENTY OF MID LEVEL MOISTURE LIFTING
ACROSS THE CENTRAL AND SRN ROCKIES. WITH BOTH THE GFS AND NAM SOLNS
INDICATING PLENTY OF MID LEVEL MOISTURE AND WEAK MID LEVEL
LIFT...WENT AHEAD AND TRENDED POPS UP IN THE SWRN CWA...TO BETTER
REFLECT THE LATEST GUIDANCE. AS FOR QPF AND SNOW AMOUNTS...USED A
BLEND OF THE NAM AND GFS SOLNS WEIGHTED MORE TOWARD THE GFS SOLN.
THIS LED TO QPF`S RANGING FROM AROUND A HUNDREDTH AN INCH IN THE
CENTRAL SANDHILLS TO A MAX OF 5 TO 7 HUNDREDTHS IN THE FAR
SOUTHEASTERN CWA. WITH TEMPS OVERNIGHT FORECAST IN THE 20S...AND
UTILIZING A SNOW/WATER RATIO OF 13 TO 1...TOTAL SNOWFALL THROUGH
WEDS NIGHT SHOULD RANGE FROM A HALF TO AN INCH. MAINLY SOUTH OF THE
INTERSTATE...AS WELL AS SOUTHERN CUSTER COUNTY. AS THE SNOW EXITS
FROM WEST TO EAST OVERNIGHT WEDS NIGHT INTO THURSDAY MORNING...MID
LEVEL DRYING WILL OCCUR AS A WARM FRONT LIFTS INTO WESTERN NEBRASKA
THURSDAY MORNING...BECOMING ORIENTED ALONG HIGHWAY 83 BY MIDDAY
THURSDAY. WITH A SATURATED BOUNDARY LAYER...DRYING IN THE MID LEVEL
AND WEAK LIFT IN THE BOUNDARY LAYER...AND SUB FREEZING TEMPS
EXPECTED THURSDAY MORNING...DECIDED TO INSERT SOME PATCHY FREEZING
DRIZZLE ACROSS PARTS OF SWRN NEBRASKA...AS WELL AS THE WESTERN
SANDHILLS. THE THREAT SHOULD END BY MIDDAY AS TEMPERATURES WARM INTO
THE LOWER TO MIDDLE 30S. FOR THURSDAY NIGHT AND FRIDAY...SKIES WILL
BEGIN TO CLEAR FROM WEST TO EAST THURSDAY NIGHT...LEADING TO LOWS IN
THE SINGLE DIGITS TO AROUND 10 DEGREES. FURTHER EAST...BOUNDARY
LAYER RH WILL REMAIN AROUND 100 PERCENT OVERNIGHT...SO CLOUDY SKIES
AND WARMER LOWS IN THE TEENS ARE FORECAST. ON FRIDAY...WESTERLY
WINDS AND CLEARING SKIES WILL PUSH HIGHS INTO THE MID TO UPPER 30S.
THE EXCEPTION WILL BE IN THE NORTHEAST...WHERE CLOUDS WILL HOLD ON
LONGER...RESULTING IN HIGHS AROUND 30.
FRIDAY NIGHT THROUGH TUESDAY...BENIGN WEATHER CONDITIONS ARE
EXPECTED SATURDAY AND SUNDAY THANKS TO LOW AMPLITUDE RIDGING
ALOFT...WESTERLY WINDS AND WARMER H85 TEMPS. HIGHS ON SATURDAY WILL
REACH THE 30S...WHILE HIGHS SUNDAY AND MONDAY WILL REACH THE 40S. ON
MONDAY NIGHT...AN ARCTIC FRONT WILL DROP THROUGH THE FORECAST AREA
BRINGING AN INCREASED CHANCE FOR LIGHT SNOW AND COOLER TEMPS. HIGHS
TUESDAY WILL BE IN THE UPPER 30S TO LOWER 40S WITH THE MAIN THREAT
FOR SNOW BEING ON MONDAY NIGHT. BEYOND TUESDAY...THE LONG RANGE
MODELS BEGIN TO DIVERGE IN THEIR SOLUTIONS TOWARD THE MIDDLE AND END
OF NEXT WEEK. THE GFS SOLUTION...HAS A MORE ACTIVE NORTHERN
STREAM...WHICH WOULD FAVOR INCREASED SNOW CHANCES FOR CHRISTMAS DAY
AND MUCH COLDER TEMPS. THE ECMWF SOLN FAVORS A STRONGER SRN STREAM
JET...WITH WARMING MIDWEEK AND CHRISTMAS...FOLLOWED BY A STRONG
CLOSED SYSTEM ACROSS THE SWRN CONUS NEXT WEEKEND. FOR NOW...WILL
CONFINE POPS TO THE MONDAY NIGHT TIME PERIOD AS DECENT MODEL
AGREEMENT EXISTS WITH THE FROPA MONDAY
NIGHT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 528 PM CST TUE DEC 16 2014
EXPECT THE VFR ACROSS SWRN NEB WOULD FILL IN WITH IFR TONIGHT.
LIFR IN FOG MAY FORM ACROSS SWRN NEB AS INDICATED BY THE RUC MODEL
WHICH WORKED QUITE WELL LAST NIGHT.
THE FOG MAY LIFT DUE NORTH INTO WRN NEB WEDS MORNING AS SOUTH
WINDS INCREASE. IFR/MVFR CIGS ARE EXPECTED TO PERSIST THROUGHOUT
THE DAY AS STEADY SOUTHEAST WINDS CONTINUE AT THE LOWER LEVELS.
NOTE THE RADAR RETURNS ACROSS THE PANHANDLE ARE IN THE MID
LEVELS...NOT REACHING THE GROUND...AND THE MODELS ARE SPLIT WITH
SOME SHOWING LIGHT ACCUMMULATING SNOW WHILE OTHERS DO NOT. EITHER
WAY...SNOWFALL SHOULD BE LOCALIZED.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...MASEK
LONG TERM...CLB
AVIATION...CDC
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 NEWPORT/MOREHEAD CITY NC
928 PM EST TUE DEC 16 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST THIS EVENING AND MOVE
THROUGH THE AREA TONIGHT. HIGH PRESSURE WILL BUILD IN FROM THE
NORTHWEST WEDNESDAY THROUGH FRIDAY. DEVELOPING LOW PRESSURE WILL
MOVE ALONG THE COAST SATURDAY INTO SUNDAY. HIGH PRESSURE IS
EXPECTED TO BUILD OVER THE AREA MONDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 925 PM TUESDAY...A BROKEN LINE OF SHOWERS HAS FORMED OVER
THE COASTAL PLAIN JUST AHEAD OF THE COLD FRONT THIS EVENING.
LATEST HRRR MODEL PUSHES THESE SHOWERS OFFSHORE BY 04Z. LOOKS LIKE
THE FRONT SHOULD BE JUST OFF OF THE COAST BY 05Z FOLLOWED BY A NW
FLOW OF DRIER AIR OVERNIGHT. LIKE WE MENTIONED IN THE PREVIOUS
DISCUSSION PATCHY DENSE FOG FORMED OVER THE COASTAL PLAIN IN THE
SLACK GRADIENT EARLIER THIS EVENING. STILL EXPECT THIS FOG TO
DISSIPATE BY 06Z AS AT LEAST A BRIEF PERIOD OF MIXING IS EXPECTED
FOLLOWING THE FRONTAL PASSAGE AS EVIDENCED BY 3 MB 3HRLY PRESSURE
RISES BEHIND THE FRONT. WINDS INLAND SHOULD DECOUPLE AGAIN LATE
BUT WITH DRY ADVECTION FORECAST OVERNIGHT DENSE FOG IS NOT LIKELY
TO REDEVELOP. OVERNIGHT LOWS WILL BE MILD DESPITE THE FRONTAL
PASSAGE DUE TO PACIFIC NATURE OF THE POST FRONTAL AIRMASS WITH
READINGS IN THE LOW/MID 40S IN MOST AREAS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
AS OF 310 PM TUESDAY...HIGH PRESSURE WILL BUILD IN FROM THE WEST
BEHIND THE COLD FRONT ON WEDNESDAY WITH WEAK COLD AIR ADVECTION
HOLDING MAXIMUM TEMPERATURES IN THE MID/UPPER 50S...UP TO TEN
DEGREES COOLER THAN TODAY. GUSTY W/WNW WINDS SHOULD DIMINISH BY
THE AFTERNOON HOURS UNDER GENERALLY SUNNY SKIES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
AS OF 103 PM TUE...NEARLY ZONAL FLOW IN THE MID TO UPPER LEVELS FROM
MIDWEEK INTO THE BEGINNING OF THE WEEKEND. HIGH PRESSURE AT THE
SURFACE WILL GRADUALLY BUILD IN THROUGH THE END OF THE WEEK. A
SOUTHERN STREAM SYSTEM WILL MOVE FROM THE SOUTHWEST THROUGH THE GULF
COAST STATES AND INTO THE SOUTHEAST BY SATURDAY AFTERNOON.
CONFIDENCE IS LOW ON THE TIMING AND STRENGTH OF THIS SYSTEM AS IT
APPROACHES EASTERN NORTH CAROLINA SATURDAY WITH THE ECMWF STRONGER
AND SLIGHTLY SLOWER. EITHER WAY...EXPECT WEEKEND TO BE WET AND
BREEZY WITH LOW OFF THE COAST SUNDAY MORNING. MODELS HAVE A LITTLE
MORE DISAGREEMENT BY SUNDAY NIGHT AS IT ECMWF DEEPENS THE SURFACE
LOW OFF THE NORTH CAROLINA COAST WHILE THE GFSENS LIFTS THE LOW OUT
OF THE AREA MUCH FASTER. AM EXPECTING SOME COASTAL PROBLEMS AS THIS
SYSTEM LIFTS OUT WITH EXTENDED NORTHEASTERLY FLOW. FORECAST
SOUNDINGS INDICATING PTYPE NOT TO BE A PROBLEM.
HIGH PRESSURE WILL BUILD BACK IN TO EASTERN NORTH CAROLINA LATE
MONDAY WITH STRONG UPPER LOW NORTH OF THE GREAT LAKES AND FULL
LATITUDE TROUGHING OVER THE PLAINS STATES.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /THROUGH 00Z THURSDAY/...
AS OF 700 PM TUESDAY...THE BAND OF SHOWERS WILL BE EAST OF THE TAF
SITES BY 00Z BUT SLACK GRADIENT AND MOIST LEVELS WILL LEAD TO MVFR
CEILINGS PERSISTING AND LOCALLY DENSE FOG. THE GRADIENT WILL
BRIEFLY INCREASE FOLLOWING THE FRONTAL PASSAGE AFTER MIDNIGHT AND
THIS WILL DISSIPATE ANY FOG AND CLEAR THE CEILINGS OUT. LATE
TONIGHT WINDS MAY DECOUPLE AGAIN LATE BUT DEWPOINTS ARE FORECAST
TO DECREASE IN LOW LEVEL DRY ADVECTION SO WILL LEAVE FOG OUT OF
THE TAF LATE BUT IT IS NOTED THAT BUFKIT IS INDICATING DENSE FOG
DEVELOPING LATE AT KPGV/KISO WHERE WINDS SHOULD BE CALM LATE.
WEDNESDAY DOWNSLOPE WESTERLY FLOW WILL PRODUCE DRY WEATHER AND VFR
CONDITIONS ACROSS EASTERN NC.
LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 111 PM TUE...EXPECT VFR CONDITIONS THROUGH THE END OF THE WEEK
AND INTO THE WEEKEND. SYSTEM APPROACHING FROM THE SOUTHWEST WILL
GIVE AREA TAFS SUB VFR CONDITIONS STARTING AS EARLY AS SATURDAY
MORNING. CONFIDENCE IS LOW ON THE TIMING OF THE PRECIPITATION. AREA
MAY ALSO HAVE BREEZY CONDITIONS ASSOCIATED WITH THIS SYSTEM.
CONDITIONS EXPECTED TO IMPROVE SUNDAY.
&&
.MARINE...
SHORT TERM /TONIGHT AND WEDNESDAY/...
AS OF 925 PM TUESDAY...NO CHANGES TO PREVIOUS THINKING. S/SW WINDS
CONTINUE ACROSS ALL WATERS AT 10 TO 15 KNOTS. THESE WINDS SHOULD
INCREASE TO 15 TO 20 KNOTS LATER THIS EVENING WITH A FEW GUSTS TO
NEAR 25 KNOTS POSSIBLE. LIKEWISE...SEAS ARE 2 TO 4 FT WITH 6 FT
BEING REPORTED AT BUOY 41025 AND 7 FT @ FRYING PAN WHERE PROXIMITY
TO WARMER IS ALLOWING FOR BETTER MIXING/STRONGER WINDS WHICH IS IN
LINE WITH BOTH THE LOCAL NWPS AND WAVEWATCH WAVE MODELS WHICH
INDICATE A FEW AREAS OF 6 FOOT SEAS OVER THE OUTER EDGES OF THE
MARINE ZONES. WINDS/SEAS SUBSIDE QUICKLY ON OFFSHORE WNW/NW WINDS
ON WEDNESDAY.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 126 PM TUE...SURFACE LOW PRESSURE OFF THE NEW ENGLAND COAST
WILL BE GIVING MODERATE NORTHWESTERLY FLOW TO THE NORTH CAROLINA
COASTAL WATERS AT THE BEGINNING OF THE FORECAST PERIOD. SPEEDS
GENERALLY IN THE 15 TO 20 KNOT RANGE WITH GRADIENT LOOSENING THROUGH
THE DAY. HIGH PRESSURE WILL TRY TO BUILD IN FROM THE NORTHWEST
THROUGH THE END OF THE WEEK KEEPING MAINLY NORTHWESTERLY FLOW OVER
THE WATERS GRADUALLY DECREASING TO AROUND 10 KNOTS BY THE END OF THE
WEEK.
NEXT SYSTEM WILL APPROACH THE AREA ON SATURDAY. CONFIDENCE IS LOW ON
THE TIMING AND STRENGTH OF THE SURFACE LOW PRESSURE THAT WILL MOVE
OUT OF THE SOUTHWEST...THROUGH THE GULF COAST REGION AND INTO THE
SOUTHEAST BY SATURDAY. MODELS DO AGREE THAT WIND SPEEDS WILL REMAIN
BELOW ADVISORY CRITERIA...POSSIBLY REACHING BORDERLINE SMALL CRAFT
ADVISORY BEHIND THE LOW PRESSURE AS IT DEEPENS NORTH OF THE WATERS.
HOWEVER SEAS COULD REACH 6 FEET OR HIGHER LATE SATURDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EST WEDNESDAY FOR AMZ152-154-
156-158.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC/JME
SHORT TERM...CTC
LONG TERM...CGG
AVIATION...CGG
MARINE...CGG/CTC/JME
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
920 PM EST TUE DEC 16 2014
.SYNOPSIS...
SHOWERS WILL MOVE OFFSHORE TONIGHT AS A COLD FRONT CROSSES THE
COAST. SEASONABLY COOL AND FAIR WEATHER WILL FOLLOW WEDNESDAY
THROUGH FRIDAY. AN APPROACHING STORM SYSTEM COULD BRING WET
WEATHER DURING THE UPCOMING WEEKEND. A DRYING TREND IS EXPECTED
EARLY NEXT WEEK WITH SEASONABLE TEMPERATURES...AS HIGH PRESSURE
FROM THE UPPER MID-WEST DROPS SOUTHEAST INTO THE CAROLINAS.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 920 PM TUESDAY...THIS HAS BEEN THE LITTLE LINE OF SHOWERS THAT
COULD! EVEN THE HRRR HAS NOT SHOWN THE INCREDIBLY SOLID LINE OF
SHALLOW CONVECTION WE HAVE MOVING EAST ACROSS THE AREA. RAINFALL
AMOUNTS HAVE BEEN LIGHT...GENERALLY UNDER A TENTH OF AN INCH. THE
LUMBERTON ASOS REPORTED 0.11 AND THE LUMBERTON MESONET STATION HAD
0.14, THE TWO HIGHEST GAUGE TOTALS AVAILABLE TO US. RADAR ESTIMATES
ARE UPWARDS OF HALF AN INCH ACROSS NORTHERN ROBESON COUNTY NEAR THE
CUMBERLAND COUNTY LINE. CONVECTIVE ACTIVITY SHOULD CONTINUE TO
ADVECT EASTWARD AND OFF THE COAST BY MIDNIGHT. IN ITS WAKE CLEAR
SKIES ARE STILL EXPECTED. PREVIOUS DISCUSSION FROM 645 PM FOLLOWS...
THE FIRST WAVE OF PREFRONTAL SHOWERS AND SPRINKLES HAVE DIMINISHED
AND/OR MOVED EAST OF THE AREA. HOWEVER RADAR COMPOSITES SHOW A
NARROW BAND OF SHOWERS DEVELOPING ALONG THE FRONT ITSELF...CURRENTLY
ACROSS FAYETTEVILLE, LAURINBURG AND BENNETTSVILLE. ENVIRONMENTAL
LAPSE RATES BETWEEN 850 AND 600 MB ARE ACTUALLY QUITE STEEP (NEAR
6.5 DEG/KM OR MOIST-ADIABATIC) AND THIS ACTIVITY IS CONVECTIVE IN
NATURE WITH RADAR REFLECTIVITY IMPLYING THERE MAY BE A FEW MINUTES
OF QUITE HEAVY RAINFALL. SPC AUTOMATED MESOANALYSIS IS SHOWING
ELEVATED CAPE AROUND 100 J/KG AHEAD OF THE FRONT. MOISTURE IS A
LIMITING FACTOR WITH DEWPOINTS GENERALLY IN THE 50S WITH LIMITED
ATLANTIC INFLOW AND VIRTUALLY NO MOISTURE FROM THE GULF OF MEXICO.
LATEST HRRR MODEL RUNS INDICATE SCATTERED SHOWERS MAINLY ACROSS SE
NORTH CAROLINA CONTINUING FOR THE NEXT 2-3 HOURS...THEN SHIFTING
OFFSHORE. ACTIVITY WILL BE MORE SPARSE OR ENTIRELY ABSENT ACROSS NE
SOUTH CAROLINA AS THE BEST SYNOPTIC/UPPER LEVEL FORCING REMAINS
NORTH. NO CHANGES HAVE BEEN MADE TO FORECAST LOW TEMPS...AROUND 40
INLAND WITH MID 40S ON THE NC BEACHES.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 345 PM TUESDAY...FAIR AND DRY WED/THU. SUBSIDENCE
OVERWHELMS THE COLUMN ENSURING A DEEP LAYER OF LOW RH AND WEST
WIND FLOW IN MID/UPPER ALTITUDES. PACIFIC ORIGIN SYSTEM AND
GENERAL WEST TO EAST FLOW RESULTING IN ONLY WEAK COOL AIR
ADVECTION AND MAXIMUMS WED LOOK TO REBOUND A FEW DEGREES ABOVE
NORMAL FOR MID DECEMBER. A SECONDARY BUT WEAK HIGH PRESSURE SURGE
MAY RESULT IN MAXIMUMS A DEGREE OR TWO COOLER THU...WITH
MORE/INCREASING CIRRUS THURSDAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 345 PM TUESDAY...LOW CONFIDENCE SPLIT FLOW FORECAST EARLY IN
THE PERIOD. SURFACE HIGH PRESSURE TO BE COVERING A LARGE PAR OF
THE NORTHEAST AND MID ATLANTIC ON FRIDAY. SOUTHERN BRANCH FEATURE
WILL MEANWHILE BE SKIRTING THE GULF COAST. A SURPRISINGLY SLOW
MOVER GIVEN THE FAIRLY ZONAL FLOW, THIS FEATURE WILL AFFECT THE
AREA MOST ON SATURDAY. MODEL AGREEMENT APPEARS TO BE A LITTLE
BETTER IN KEEPING THE SYSTEM TO OUR SOUTH IMPLYING THAT THIS WILL
BE A LIGHT TO PERHAPS MODERATE OVERRUNNING EVENT LOCALLY. RAIN MAY
LAST INTO EARLY SUNDAY BUT AS THE SYSTEM EXITS TO THE NORTHEAST
(WHETHER OR NOT IN A STRENGTHENING STATE) SOME DRY AIR WILL PUSH
INTO THE AREA FROM THE NW. THIS NEW AREA OF HIGH PRESSURE WILL
REMAIN TO OUR NORTHWEST FOR THE REMAINDER OF THE PERIOD WHILE THE
FLOW ALOFT REMAINS WEAKLY SPLIT. EARLY IN THE PERIOD DAYTIME HIGHS
WILL BE A BIT SUPPRESSED BY CLOUDS AND/OR RAIN WHILE NIGHTTIME
LOWS REMAIN SLIGHTLY ELEVATED ABOVE CLIMO FOR THE SAME REASON.
WITH THE ARRIVAL OF THE COOLER DRY AIR DAYTIME HIGHS MAY TAKE A
SMALL HIT WHILE NIGHTTIME LOWS LOSE THE BENEFIT OF CLOUDS AND
RETURN TO NORMAL OR CLOSE TO IT.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 00Z...COLD FRONT APPROACHING KFLO/KLBT. MAINLY MID LEVEL CIGS
THIS EVENING BUT THERE ARE PATCHY 2.5-3.5K CIGS ALONG FRONT. SHOWERS
WELL IN ADVANCE OF THE COLD FRONT ARE EXITING THE COAST NEAREST
KILM...BUT A FEW ISOLATED SHOWERS ARE POPPING UP ALONG THE FRONT NW
OF KLBT.
THE FRONT WILL MOVE THROUGH KFLO/KLBT WITHIN THE NEXT HOUR OR TWO
AND THE COASTAL TERMINALS LATER THIS EVENING. THERE IS SOME CONCERN
FOR SUB-VFR VSBYS/CIGS AS WINDS DECREASE AND COOL AIR MOVES ACROSS
SLIGHTLY MOIST SOILS AT KFLO/KLBT AND KCRE. THIS SHOULD MIX OUT 2-4
HOURS AFTER FROPA.
VFR EXPECTED AFTER SUNRISE WITH NW WINDS 5-9 KT.
EXTENDED OUTLOOK...VFR WED THROUGH FRIDAY. A CHANCE OF RAIN ON
SATURDAY AND SUNDAY WITH POSSIBLE MVFR/IFR CONDITIONS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 920 PM TUESDAY...WINDS ARE AT THEIR STRONGEST ACROSS THE
COASTAL WATERS CURRENTLY, AROUND 20 KNOTS, AND SHOULD DIMINISH AS
THE FRONT CROSSES OFFSHORE. AT 9 PM THE FRONT EXTENDS FROM WESTERN
PENDER COUNTY ACROSS WHITEVILLE TO WESTERN HORRY COUNTY, MOVING EAST
AT 25 KNOTS. THE BIGGEST CHANGE WITH THIS UPDATE WAS TO INCREASE
SHOWER CHANCES ACROSS THE NC COASTAL WATERS BASED ON UPSTREAM RADAR
IMAGERY AND MESOANALYSIS CONTINUING TO SHOW SMALL BUT POSITIVE
INSTABILITY ALOFT. PREVIOUS DISCUSSION FROM 645 PM FOLLOWS...
WINDS ARE A SOLID 20 KNOTS ACROSS THE COASTAL WATERS AND MAY
ACTUALLY INCREASE TOWARD 25 KNOTS FOR A SHORT PERIOD BETWEEN 7-9 PM
AHEAD OF THE COLD FRONT...NOW MOVING INTO THE WESTERN PORTIONS OF
THE COASTAL PLAIN. THIS FRONT SHOULD PUSH OFF THE COAST LATE THIS
EVENING WITH WINDS VEERING AROUND TO THE NW AND DIMINISHING TO 15
KNOTS OR LESS. SEAS HAVE BUILT TO 6 FEET OUT AT FRYING PAN
SHOALS...WITH BUOYS CLOSER TO SHORE READING ANYWHERE FROM 2-5 FEET
DEPENDING ON HOW OPEN THEY ARE TO FETCH FROM SW WINDS.
THE BIGGEST CHANGE WITH THIS FORECAST UPDATE WAS TO INCREASE
FORECAST WAVES ALONG THE BRUNSWICK COUNTY BEACHES BY ~3 FEET TO 4-5
FEET GIVEN THE LONG ONSHORE FETCH. WHEN WAVE DATA WAS AVAILABLE FROM
THE OCEAN CREST PIER (STILL OUT OF SERVICE AT THIS TIME) IT TAUGHT
US A LOT ABOUT WAVE BEHAVIOR HERE GIVEN VARIOUS WIND DIRECTIONS.
ONCE WINDS VEER NW BEHIND THE FRONT SEAS SHOULD BEGIN TO DIMINISH.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 345 PM TUESDAY...BUMPY SEAS WILL LINGER INTO DAYBREAK
WEDNESDAY AS AN EXERCISE CAUTION STATEMENT RUNS THROUGH 12Z/7AM
WEDNESDAY. SW WAVES 2-4 FT EVERY 4 SECONDS WILL CO-MINGLE WITH
LIGHT NW CHOP AND ESE WAVE 1 FT OR LESS EVERY 10-11 SECONDS FOR A
GOOD PART OF WED BEFORE WIND-WAVES EASE IN THE AFTN. BY THU 2 FT
SEAS ON THE WATERS AND LIGHT N-NNE WIND. NO TSTMS OR RESTRICTIONS
TO VISIBILITY ON THE 0-20NM WATERS WED/THU.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 345 PM TUESDAY...FLOW REMAINS MOSTLY NORTHERLY ON FRIDAY
WITH HIGH PRESSURE ENTRENCHED ACROSS MOST OF THE NORTHEAST AND
MIDATLANTIC. LOW PRESSURE DEVELOPING ALONG THE GULF STATES TO MOVE
VERY SLOWLY EASTWARD. THIS SYSTEM WILL AFFECT THE AREA ON
SATURDAY...REMAINING TO OUR SOUTH AS IT PASSES BY. THE ENCROACHING
WARM FRONT MAY VEER THE FLOW OVER PART OF THE REGION BUT ITS TOUGH
TO SAY EXACTLY HOW FAR NORTH THIS BOUNDARY TRAVERSES. REGARDLESS
WIND AND SEAS BOTH TO REMAIN BELOW ADVISORY OR SCEC REALM THROUGH
THE PERIOD. NORTHWESTERLY WINDS GET UNDERWAY SUNDAY AS THIS SYSTEM
EXITS...ONCE AGAIN WITH NO REAL STRENGTH TO THE GRADIENT AND THUS
NO CONCERN FOR ANY CAUTIONARY HEADLINES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...8
NEAR TERM...TRA
SHORT TERM...MJC
LONG TERM...MBB
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
700 PM EST TUE DEC 16 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST THIS EVENING AND MOVE
THROUGH THE AREA TONIGHT. HIGH PRESSURE WILL BUILD IN FROM THE
NORTHWEST WEDNESDAY THROUGH FRIDAY. DEVELOPING LOW PRESSURE WILL
MOVE ALONG THE COAST SATURDAY INTO SUNDAY. HIGH PRESSURE IS
EXPECTED TO BUILD OVER THE AREA MONDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 700 PM TUESDAY...THE AREA OF SHOWERS/ISOLATED THUNDERSTORMS
OCCURRING AHEAD OF THE COLD FRONT CONTINUES TO RACE EAST ACROSS
THE AREA AND SHOULD BE OFFSHORE AROUND 00Z. WILL HANG ON TO A CHANCE
FOR ADDITIONAL SHOWERS AHEAD OF THE FRONT THROUGH 03Z PER HRRR AND
WRF NMM HIGH RESOLUTION MODEL SOLUTIONS. IN ADDITION TO THE
SHOWERS THE GRADIENT IS BECOMING SLACK INLAND AHEAD OF THE FRONT
LEADING TO THE DECOUPLING OF WINDS AND THE DEVELOPMENT OF LOCALLY
DENSE FOG IN AREAS THAT EARLIER RECEIVED RAIN. LOOKS LIKE THE
GRADIENT OVER LAND BRIEFLY TIGHTENS FOLLOWING THE COLD FRONTAL
PASSAGE AROUND 06Z AND THE ASSOCIATED MIXING WILL DISSIPATE ANY
FOG THAT DEVELOPS. OVERNIGHT LOWS WILL BE MILD DESPITE THE FRONTAL
PASSAGE DUE TO PACIFIC NATURE OF THE POST FRONTAL AIRMASS WITH
READINGS IN THE LOW/MID 40S IN MOST AREAS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
AS OF 310 PM TUESDAY...HIGH PRESSURE WILL BUILD IN FROM THE WEST
BEHIND THE COLD FRONT ON WEDNESDAY WITH WEAK COLD AIR ADVECTION
HOLDING MAXIMUM TEMPERATURES IN THE MID/UPPER 50S...UP TO TEN
DEGREES COOLER THAN TODAY. GUSTY W/WNW WINDS SHOULD DIMINISH BY
THE AFTERNOON HOURS UNDER GENERALLY SUNNY SKIES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
AS OF 103 PM TUE...NEARLY ZONAL FLOW IN THE MID TO UPPER LEVELS FROM
MIDWEEK INTO THE BEGINNING OF THE WEEKEND. HIGH PRESSURE AT THE
SURFACE WILL GRADUALLY BUILD IN THROUGH THE END OF THE WEEK. A
SOUTHERN STREAM SYSTEM WILL MOVE FROM THE SOUTHWEST THROUGH THE GULF
COAST STATES AND INTO THE SOUTHEAST BY SATURDAY AFTERNOON.
CONFIDENCE IS LOW ON THE TIMING AND STRENGTH OF THIS SYSTEM AS IT
APPROACHES EASTERN NORTH CAROLINA SATURDAY WITH THE ECMWF STRONGER
AND SLIGHTLY SLOWER. EITHER WAY...EXPECT WEEKEND TO BE WET AND
BREEZY WITH LOW OFF THE COAST SUNDAY MORNING. MODELS HAVE A LITTLE
MORE DISAGREEMENT BY SUNDAY NIGHT AS IT ECMWF DEEPENS THE SURFACE
LOW OFF THE NORTH CAROLINA COAST WHILE THE GFSENS LIFTS THE LOW OUT
OF THE AREA MUCH FASTER. AM EXPECTING SOME COASTAL PROBLEMS AS THIS
SYSTEM LIFTS OUT WITH EXTENDED NORTHEASTERLY FLOW. FORECAST
SOUNDINGS INDICATING PTYPE NOT TO BE A PROBLEM.
HIGH PRESSURE WILL BUILD BACK IN TO EASTERN NORTH CAROLINA LATE
MONDAY WITH STRONG UPPER LOW NORTH OF THE GREAT LAKES AND FULL
LATITUDE TROUGHING OVER THE PLAINS STATES.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /THROUGH 00Z THURSDAY/...
AS OF 700 PM TUESDAY...THE BAND OF SHOWERS WILL BE EAST OF THE TAF
SITES BY 00Z BUT SLACK GRADIENT AND MOIST LEVELS WILL LEAD TO MVFR
CEILINGS PERSISTING AND LOCALLY DENSE FOG. THE GRADIENT WILL
BRIEFLY INCREASE FOLLOWING THE FRONTAL PASSAGE AFTER MIDNIGHT AND
THIS WILL DISSIPATE ANY FOG AND CLEAR THE CEILINGS OUT. LATE
TONIGHT WINDS MAY DECOUPLE AGAIN LATE BUT DEWPOINTS ARE FORECAST
TO DECREASE IN LOW LEVEL DRY ADVECTION SO WILL LEAVE FOG OUT OF
THE TAF LATE BUT IT IS NOTED THAT BUFKIT IS INDICATING DENSE FOG
DEVELOPING LATE AT KPGV/KISO WHERE WINDS SHOULD BE CALM LATE.
WEDNESDAY DOWNSLOPE WESTERLY FLOW WILL PRODUCE DRY WEATHER AND VFR
CONDITIONS ACROSS EASTERN NC.
LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 111 PM TUE...EXPECT VFR CONDITIONS THROUGH THE END OF THE WEEK
AND INTO THE WEEKEND. SYSTEM APPROACHING FROM THE SOUTHWEST WILL
GIVE AREA TAFS SUB VFR CONDITIONS STARTING AS EARLY AS SATURDAY
MORNING. CONFIDENCE IS LOW ON THE TIMING OF THE PRECIPITATION. AREA
MAY ALSO HAVE BREEZY CONDITIONS ASSOCIATED WITH THIS SYSTEM.
CONDITIONS EXPECTED TO IMPROVE SUNDAY.
&&
.MARINE...
SHORT TERM /TONIGHT AND WEDNESDAY/...
AS OF 700 PM TUESDAY...NO CHANGES TO PREVIOUS THINKING. WINDS
HAVE VEERED TO S/SW ON ALL WATERS AT 10 TO 15 KNOTS. THESE WINDS
SHOULD INCREASE TO 15 TO 20 KNOTS LATER THIS EVENING WITH A FEW
GUSTS TO NEAR 25 KNOTS POSSIBLE. LIKEWISE...SEAS ARE GENERALLY
AROUND 2 FEET...BUT 5 FEET AT DIAMOND BUOY. PER LATEST LOCAL
SWAN/NWPS AND WAVEWATCH...A FEW AREAS OF 6 FOOT SEAS ARE
POSSIBLE...ESPECIALLY OVER THE OUTER EDGES OF THE MARINE ZONES
LATER THIS EVENING INTO TONIGHT. EXTENDED THE SMALL CRAFT ADVISORY
SOUTH OF OREGON INLET UNTIL 12Z ON WEDNESDAY TO ACCOUNT FOR THE
LATEST WAVE MODELING RUNS. WINDS/SEAS SUBSIDE QUICKLY ON OFFSHORE
WNW/NW WINDS ON WEDNESDAY.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 126 PM TUE...SURFACE LOW PRESSURE OFF THE NEW ENGLAND COAST
WILL BE GIVING MODERATE NORTHWESTERLY FLOW TO THE NORTH CAROLINA
COASTAL WATERS AT THE BEGINNING OF THE FORECAST PERIOD. SPEEDS
GENERALLY IN THE 15 TO 20 KNOT RANGE WITH GRADIENT LOOSENING THROUGH
THE DAY. HIGH PRESSURE WILL TRY TO BUILD IN FROM THE NORTHWEST
THROUGH THE END OF THE WEEK KEEPING MAINLY NORTHWESTERLY FLOW OVER
THE WATERS GRADUALLY DECREASING TO AROUND 10 KNOTS BY THE END OF THE
WEEK.
NEXT SYSTEM WILL APPROACH THE AREA ON SATURDAY. CONFIDENCE IS LOW ON
THE TIMING AND STRENGTH OF THE SURFACE LOW PRESSURE THAT WILL MOVE
OUT OF THE SOUTHWEST...THROUGH THE GULF COAST REGION AND INTO THE
SOUTHEAST BY SATURDAY. MODELS DO AGREE THAT WIND SPEEDS WILL REMAIN
BELOW ADVISORY CRITERIA...POSSIBLY REACHING BORDERLINE SMALL CRAFT
ADVISORY BEHIND THE LOW PRESSURE AS IT DEEPENS NORTH OF THE WATERS.
HOWEVER SEAS COULD REACH 6 FEET OR HIGHER LATE SATURDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EST WEDNESDAY FOR AMZ152-154-
156-158.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC/JME
SHORT TERM...CTC
LONG TERM...CGG
AVIATION...CGG
MARINE...CGG/CTC/JME
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
650 PM EST TUE DEC 16 2014
.SYNOPSIS...
SHOWERS WILL MOVE OFFSHORE TONIGHT AS A COLD FRONT CROSSES THE
COAST. SEASONABLY COOL AND FAIR WEATHER WILL FOLLOW WEDNESDAY
THROUGH FRIDAY. AN APPROACHING STORM SYSTEM COULD BRING WET
WEATHER DURING THE UPCOMING WEEKEND. A DRYING TREND IS EXPECTED
EARLY NEXT WEEK WITH SEASONABLE TEMPERATURES...AS HIGH PRESSURE
FROM THE UPPER MID-WEST DROPS SOUTHEAST INTO THE CAROLINAS.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 645 PM TUESDAY...THE FIRST WAVE OF PREFRONTAL SHOWERS AND
SPRINKLES HAVE DIMINISHED AND/OR MOVED EAST OF THE AREA. HOWEVER
RADAR COMPOSITES SHOW A NARROW BAND OF SHOWERS DEVELOPING ALONG THE
FRONT ITSELF...CURRENTLY ACROSS FAYETTEVILLE, LAURINBURG AND
BENNETTSVILLE. ENVIRONMENTAL LAPSE RATES BETWEEN 850 AND 600 MB ARE
ACTUALLY QUITE STEEP (NEAR 6.5 DEG/KM OR MOIST-ADIABATIC) AND THIS
ACTIVITY IS CONVECTIVE IN NATURE WITH RADAR REFLECTIVITY IMPLYING
THERE MAY BE A FEW MINUTES OF QUITE HEAVY RAINFALL. SPC AUTOMATED
MESOANALYSIS IS SHOWING ELEVATED CAPE AROUND 100 J/KG AHEAD OF THE
FRONT. MOISTURE IS A LIMITING FACTOR WITH DEWPOINTS GENERALLY IN THE
50S WITH LIMITED ATLANTIC INFLOW AND VIRTUALLY NO MOISTURE FROM THE
GULF OF MEXICO.
LATEST HRRR MODEL RUNS INDICATE SCATTERED SHOWERS MAINLY ACROSS SE
NORTH CAROLINA CONTINUING FOR THE NEXT 2-3 HOURS...THEN SHIFTING
OFFSHORE. ACTIVITY WILL BE MORE SPARSE OR ENTIRELY ABSENT ACROSS NE
SOUTH CAROLINA AS THE BEST SYNOPTIC/UPPER LEVEL FORCING REMAINS
NORTH. NO CHANGES HAVE BEEN MADE TO FORECAST LOW TEMPS...AROUND 40
INLAND WITH MID 40S ON THE NC BEACHES.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 345 PM TUESDAY...FAIR AND DRY WED/THU. SUBSIDENCE
OVERWHELMS THE COLUMN ENSURING A DEEP LAYER OF LOW RH AND WEST
WIND FLOW IN MID/UPPER ALTITUDES. PACIFIC ORIGIN SYSTEM AND
GENERAL WEST TO EAST FLOW RESULTING IN ONLY WEAK COOL AIR
ADVECTION AND MAXIMUMS WED LOOK TO REBOUND A FEW DEGREES ABOVE
NORMAL FOR MID DECEMBER. A SECONDARY BUT WEAK HIGH PRESSURE SURGE
MAY RESULT IN MAXIMUMS A DEGREE OR TWO COOLER THU...WITH
MORE/INCREASING CIRRUS THURSDAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 345 PM TUESDAY...LOW CONFIDENCE SPLIT FLOW FORECAST EARLY IN
THE PERIOD. SURFACE HIGH PRESSURE TO BE COVERING A LARGE PAR OF
THE NORTHEAST AND MID ATLANTIC ON FRIDAY. SOUTHERN BRANCH FEATURE
WILL MEANWHILE BE SKIRTING THE GULF COAST. A SURPRISINGLY SLOW
MOVER GIVEN THE FAIRLY ZONAL FLOW, THIS FEATURE WILL AFFECT THE
AREA MOST ON SATURDAY. MODEL AGREEMENT APPEARS TO BE A LITTLE
BETTER IN KEEPING THE SYSTEM TO OUR SOUTH IMPLYING THAT THIS WILL
BE A LIGHT TO PERHAPS MODERATE OVERRUNNING EVENT LOCALLY. RAIN MAY
LAST INTO EARLY SUNDAY BUT AS THE SYSTEM EXITS TO THE NORTHEAST
(WHETHER OR NOT IN A STRENGTHENING STATE) SOME DRY AIR WILL PUSH
INTO THE AREA FROM THE NW. THIS NEW AREA OF HIGH PRESSURE WILL
REMAIN TO OUR NORTHWEST FOR THE REMAINDER OF THE PERIOD WHILE THE
FLOW ALOFT REMAINS WEAKLY SPLIT. EARLY IN THE PERIOD DAYTIME HIGHS
WILL BE A BIT SUPPRESSED BY CLOUDS AND/OR RAIN WHILE NIGHTTIME
LOWS REMAIN SLIGHTLY ELEVATED ABOVE CLIMO FOR THE SAME REASON.
WITH THE ARRIVAL OF THE COOLER DRY AIR DAYTIME HIGHS MAY TAKE A
SMALL HIT WHILE NIGHTTIME LOWS LOSE THE BENEFIT OF CLOUDS AND
RETURN TO NORMAL OR CLOSE TO IT.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 00Z...COLD FRONT APPROACHING KFLO/KLBT. MAINLY MID LEVEL CIGS
THIS EVENING BUT THERE ARE PATCHY 2.5-3.5K CIGS ALONG FRONT. SHOWERS
WELL IN ADVANCE OF THE COLD FRONT ARE EXITING THE COAST NEAREST
KILM...BUT A FEW ISOLATED SHOWERS ARE POPPING UP ALONG THE FRONT NW
OF KLBT.
THE FRONT WILL MOVE THROUGH KFLO/KLBT WITHIN THE NEXT HOUR OR TWO
AND THE COASTAL TERMINALS LATER THIS EVENING. THERE IS SOME CONCERN
FOR SUB-VFR VSBYS/CIGS AS WINDS DECREASE AND COOL AIR MOVES ACROSS
SLIGHTLY MOIST SOILS AT KFLO/KLBT AND KCRE. THIS SHOULD MIX OUT 2-4
HOURS AFTER FROPA.
VFR EXPECTED AFTER SUNRISE WITH NW WINDS 5-9 KT.
EXTENDED OUTLOOK...VFR WED THROUGH FRIDAY. A CHANCE OF RAIN ON
SATURDAY AND SUNDAY WITH POSSIBLE MVFR/IFR CONDITIONS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 645 PM TUESDAY...WINDS ARE A SOLID 20 KNOTS ACROSS THE COASTAL
WATERS AND MAY ACTUALLY INCREASE TOWARD 25 KNOTS FOR A SHORT PERIOD
BETWEEN 7-9 PM AHEAD OF THE COLD FRONT...NOW MOVING INTO THE WESTERN
PORTIONS OF THE COASTAL PLAIN. THIS FRONT SHOULD PUSH OFF THE COAST
LATE THIS EVENING WITH WINDS VEERING AROUND TO THE NW AND
DIMINISHING TO 15 KNOTS OR LESS. SEAS HAVE BUILT TO 6 FEET OUT AT
FRYING PAN SHOALS...WITH BUOYS CLOSER TO SHORE READING ANYWHERE FROM
2-5 FEET DEPENDING ON HOW OPEN THEY ARE TO FETCH FROM SW WINDS.
THE BIGGEST CHANGE WITH THIS FORECAST UPDATE WAS TO INCREASE
FORECAST WAVES ALONG THE BRUNSWICK COUNTY BEACHES BY ~3 FEET TO 4-5
FEET GIVEN THE LONG ONSHORE FETCH. WHEN WAVE DATA WAS AVAILABLE FROM
THE OCEAN CREST PIER (STILL OUT OF SERVICE AT THIS TIME) IT TAUGHT
US A LOT ABOUT WAVE BEHAVIOR HERE GIVEN VARIOUS WIND DIRECTIONS.
ONCE WINDS VEER NW BEHIND THE FRONT SEAS SHOULD BEGIN TO DIMINISH.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 345 PM TUESDAY...BUMPY SEAS WILL LINGER INTO DAYBREAK
WEDNESDAY AS AN EXERCISE CAUTION STATEMENT RUNS THROUGH 12Z/7AM
WEDNESDAY. SW WAVES 2-4 FT EVERY 4 SECONDS WILL CO-MINGLE WITH
LIGHT NW CHOP AND ESE WAVE 1 FT OR LESS EVERY 10-11 SECONDS FOR A
GOOD PART OF WED BEFORE WIND-WAVES EASE IN THE AFTN. BY THU 2 FT
SEAS ON THE WATERS AND LIGHT N-NNE WIND. NO TSTMS OR RESTRICTIONS
TO VISIBILITY ON THE 0-20NM WATERS WED/THU.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 345 PM TUESDAY...FLOW REMAINS MOSTLY NORTHERLY ON FRIDAY
WITH HIGH PRESSURE ENTRENCHED ACROSS MOST OF THE NORTHEAST AND
MIDATLANTIC. LOW PRESSURE DEVELOPING ALONG THE GULF STATES TO MOVE
VERY SLOWLY EASTWARD. THIS SYSTEM WILL AFFECT THE AREA ON
SATURDAY...REMAINING TO OUR SOUTH AS IT PASSES BY. THE ENCROACHING
WARM FRONT MAY VEER THE FLOW OVER PART OF THE REGION BUT ITS TOUGH
TO SAY EXACTLY HOW FAR NORTH THIS BOUNDARY TRAVERSES. REGARDLESS
WIND AND SEAS BOTH TO REMAIN BELOW ADVISORY OR SCEC REALM THROUGH
THE PERIOD. NORTHWESTERLY WINDS GET UNDERWAY SUNDAY AS THIS SYSTEM
EXITS...ONCE AGAIN WITH NO REAL STRENGTH TO THE GRADIENT AND THUS
NO CONCERN FOR ANY CAUTIONARY HEADLINES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...8
NEAR TERM...TRA
SHORT TERM...MJC
LONG TERM...MBB
AVIATION...MRR
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 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 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 WILMINGTON OH
646 PM EST TUE DEC 16 2014
.SYNOPSIS...
AS LOW PRESSURE MOVES NORTHEAST THROUGH THE GREAT LAKES...A FEW
SHOWERS WILL CONTINUE TO BE POSSIBLE INTO THE OVERNIGHT HOURS.
COOLER CONDITIONS ARE EXPECTED THROUGH THE REST OF THE WEEK...WITH
GENERALLY DRY CONDITIONS. A CHANCE OF RAIN AND SNOW IS IN THE
FORECAST FOR SATURDAY...AS WEAK LOW PRESSURE APPROACHES THE REGION
FROM THE SOUTH.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
WITHIN A LUMBERING MID-LEVEL TROUGH...CURRENTLY CENTERED OVER THE
GREAT LAKES...TWO DISTINCT VORTICITY MAXIMA ARE GRADUALLY
PROGRESSING AHEAD. THE FIRST OF THESE IS MOVING ENE THROUGH THE
SOUTHERN GREAT LAKES...WITH ITS INFLUENCE BEING FELT ACROSS THE
OHIO VALLEY...AND THROUGHOUT THE NWS ILN FORECAST AREA.
THE DIURNAL CYCLE TODAY HAS BEEN STUNTED FROM ITS RATHER WARM
STARTING POINT...AS COLD ADVECTION ON WESTERLY FLOW HAS ALREADY
BEGUN. THOUGH THERE IS NO DISTINCT DIRECTIONAL WIND SHIFT TO
HELP PICK OUT A CHANGE IN AIR MASS...THE REST OF THE DAY WILL
SIMPLY FEATURE A CONTINUED GRADUAL CLOCKWISE TURNING IN SURFACE
WINDS...ALONG WITH STEADY DROPS IN TEMPERATURES AND DEWPOINTS. A
STRONGER PUSH OF COLD ADVECTION JUST OFF THE SURFACE APPEARS
LIKELY TO BEGIN AFTER 06Z...WHICH SHOULD HELP LEAD TO STEEPER
LAPSE RATES NEAR THE GROUND...AND CONTINUED OCCASIONAL WIND GUSTS
TO AROUND 20 KNOTS. THIS WILL ALSO LIKELY KEEP RH VALUES RATHER
HIGH AT AROUND 925MB-875MB...AND LOW LEVEL CLOUDS ARE NOT EXPECTED
TO BREAK BEFORE MORNING.
RADAR HAS FINALLY STARTED TO SHOW A DIMINISHING TREND IN COVERAGE
FOR RAIN SHOWERS...AND THIS TREND IS EXPECTED TO CONTINUE. LIFT
ASSOCIATED WITH THE MID-LEVEL TROUGH IS ALREADY BEGINNING TO
DIMINISH...AS THE AXIS IS CLEARING THE CWA TO THE EAST.
HOWEVER...WITH THE THICK LOW-LEVEL MOISTURE IN PLACE...THERE
APPEARS TO BE A CHANCE FOR SOME VERY LIGHT RAIN OR DRIZZLE TO
CONTINUE INTO THE OVERNIGHT HOURS. HRRR SIMULATED REFLECTIVITY
HAS...ON SEVERAL RUNS...REFUSED TO GO COMPLETELY DRY DURING THIS
PERIOD. FORTUNATELY...IT APPEARS MOST LIKELY THAT ANY
RAIN/DRIZZLE/MIST POTENTIAL WILL BE DIMINISHING BEFORE
TEMPERATURES DROP BELOW FREEZING. THE 15Z SREF IS VERY LOW ON
PROBABILITIES FOR VISIBILITY REDUCTIONS...WHICH MAKES SENSE GIVEN
THE EXPECTED WINDS...BUT ALSO LENDS SUPPORT TOWARD WIDESPREAD MIST
OR DRIZZLE BEING UNLIKELY. THE MOST LIKELY SCENARIO WILL BE FOR A
FEW PATCHES OF LIGHT RAIN OR DRIZZLE THROUGH THE FIRST HALF OF THE
OVERNIGHT...POSSIBLY INTO THE EARLY MORNING IN CENTRAL OHIO.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS LOW PRESSURE MOVES NORTHEAST OF THE OHIO VALLEY...THE PRESSURE
GRADIENT WILL GRADUALLY RELAX ON WEDNESDAY...BUT CONTINUED COOL
WESTERLY FLOW WILL FORCE TEMPERATURES TO REMAIN BELOW AVERAGE.
ALTHOUGH DRY CONDITIONS ARE EXPECTED...THE BIGGEST FORECAST
CHALLENGE FOR WEDNESDAY WILL BE WITH SKY CONDITIONS. AS HAS BEEN
THE CASE SEVERAL TIMES ALREADY THIS COOL SEASON...THE NAM12
SOLUTION FOR LOW-LEVEL MOISTURE HAS REMAINED MUCH THICKER THAN
OTHER MODELS (GFS/GEM/ECMWF). KEEPING THE BOUNDARY LAYER WELL
MIXED BELOW 3000 FEET THROUGH THURSDAY MORNING...THE NAM12
MAINTAINS A THICK LAYER OF TRAPPED MOISTURE BELOW AN INVERSION.
DESPITE WHAT APPEARS TO BE A CONSENSUS FROM THE OTHER MODELS...THE
NAM12 HAS SHOWN SUCCESS IN THESE SCENARIOS THANKS TO ITS
RESOLUTION IN THE VERTICAL...AND IT CURRENTLY APPEARS TO BE
VERIFYING WELL OVER MISSOURI (WHERE OTHER MODELS ARE ALREADY
SUGGESTING CLEARER CONDITIONS THAN OBSERVED). SKY GRIDS HAVE THUS
BEEN INCREASED ON WEDNESDAY AND INTO WEDNESDAY NIGHT...ALLOWING
FOR SOME BREAKS IN THE EVENING.
AT 500MB ON WEDNESDAY NIGHT...A NARROW RIDGE WILL EXTEND FROM THE
SOUTHERN STATES NORTHWEST INTO THE MIDDLE MISSISSIPPI VALLEY. AS A
WEAK SHORTWAVE MOVES OUT OF THE FOUR CORNERS AREA AND RUNS INTO
THE RIDGE...IT WILL WEAKEN FURTHER...EVENTUALLY WASHING OUT OVER
THE OHIO VALLEY ON THURSDAY. BEFORE THE SYSTEM DISSIPATES...IT
APPEARS THAT SOME WEAK ISENTROPIC LIFT WILL ALLOW FOR AN INCREASE
IN CLOUDS ON THURSDAY...MOVING FROM SOUTHWEST TO NORTHEAST ACROSS
THE OHIO VALLEY. A SLIGHT CHANCE OF PRECIPITATION (MAINLY SNOW)
WAS ALSO INCLUDED...AS MOST LOCATIONS ARE LIKELY TO REMAIN
DRY...BUT SOME LIGHT PRECIPITATION MAY MAKE IT DOWN. MOST OF THE
CLOUDS AND FORCING SHOULD REMAIN ABOVE 5000 FEET...WITH AN
EXTREMELY WEAK SURFACE PRESSURE PATTERN PROVIDING NO SUPPORT.
COLD ADVECTION ON THURSDAY WILL BE MUCH WEAKER WITH THE LIGHTER
FLOW...BUT WITH A RELATIVELY SMALL DIURNAL TEMPERATURE COMPONENT
EXPECTED...TEMPERATURES ON THURSDAY ARE EXPECTED TO REMAIN FAIRLY
SIMILAR TO VALUES ON WEDNESDAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE AND DRY CONDITIONS WILL START OUT THE LONG TERM
PERIOD. THE NEXT SYSTEM WILL BEGIN TO APPROACH THE AREA LATE FRIDAY
NIGHT AND INTO THE DAY ON SATURDAY BEFORE TAPERING OFF SATURDAY
NIGHT. PRECIPITATION WILL GENERALLY BE IN THE FORM OF LIGHT SNOW
ACROSS THE NW HALF OF THE FA. PRECIPITATION IS EXPECTED TO START
OFF AS SNOW ACROSS THE SE HALF OF THE FA HOWEVER SOME RAIN IS
EXPECTED TO MIX IN DURING THE DAY BEFORE TRANSITIONING BACK TO LIGHT
SNOW.
HIGH PRESSURE WILL THEN WORK BACK INTO THE AREA FOR SUNDAY AND
MONDAY. THE NEXT SYSTEM WILL BEGIN TO WORK INTO THE AREA FOR
TUESDAY. MODELS WERE IN SOMEWHAT DECENT AGREEMENT WITH THIS FEATURE
HOWEVER THE 12Z ECMWF SOLUTION IS NOW SLOWER AND MORE ROBUST. DID
NOT WANT TO JUMP ON THIS NEW SOLUTION QUITE YET AND WENT WITH MORE
OF A MODEL BLEND FOR TUESDAY. A MIX OF RAIN AND SNOW ARE EXPECTED
HOWEVER AS COLDER AIR BEGINS TO MOVE INTO THE AREA PRECIPITATION
LOOKS TO CHANGE OVER TO ALL SNOW SHOWERS DURING THE TUESDAY NIGHT
INTO WEDNESDAY TIME PERIOD.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
LOW CLOUDS WILL PREVAIL FOR MUCH IF NOT ALL OF THE TAF PERIOD.
THERE ARE SOME DISCREPANCIES IN GUIDANCE CONCERNING CLOUDS
POTENTIALLY CLEARING AFTER 15Z. BUT BASED ON WHAT HAS BEEN
OCCURRING UPSTREAM IN REGARDS TO CLOUDS HAVE OPTED TO KEEP
FORECAST PESSIMISTIC. THERE IS SOME POTENTIAL FOR A BRIEF PERIOD
OF IFR CEILINGS EARLY IN THE TAF PERIOD. OTHERWISE MVFR CEILINGS
WILL PREVAIL. IT DOES APPEAR THAT THEY WILL LIFT ABOVE 2000 FT AT
MOST SITES AFTER 12Z. WEST WINDS WILL PERSIST. GUSTS OVER 20 KT
MAY LAST WELL THROUGH THE NIGHT BUT THEN DIMINISH ON WEDNESDAY.
OUTLOOK...MVFR CEILINGS MAY LINGER INTO WEDNESDAY NIGHT AND
THURSDAY. MVFR CEILINGS AND VISIBILITIES POSSIBLE FRIDAY NIGHT
INTO SATURDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...NOVAK
AVIATION...
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 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...UPDATED
NWS NORMAN OK
859 PM CST TUE DEC 16 2014
.UPDATE...
INCREASED SKY COVER TONIGHT. ADDED SPRINKLE MENTION IN SOUTHWESTERN
OKLAHOMA AND WESTERN NORTH TEXAS 4 TO 6 AM WEDNESDAY. INCREASED
RAIN CHANCES NEAR THE RED RIVER EAST OF WICHITA FALLS WEDNESDAY
MORNING.
&&
.DISCUSSION...
MOISTURE CONTINUES TO INCREASE ACROSS THE AREA.
BASED ON LATEST SATELLITE AND MODEL DATA...INCREASED CLOUD COVER
TONIGHT. AS A RESULT...THINK TEMPERATURES WILL REMAIN RATHER
STEADY FOR THE REST OF TONIGHT.
ADDED SPRINKLE MENTION TO THE LOCATIONS MENTIONED IN THE
UPDATE LINE AS LATEST MODEL SOUNDINGS AND HRRR SUGGESTED THIS
DEVELOPMENT. ATMOSPHERIC SOUNDINGS AND GROUND TEMPERATURES ABOVE
FREEZING SUPPORT ALL LIQUID IN THESE LOCATIONS.
PARTS OF NORTHERN OKLAHOMA MAINLY NORTHEAST OF A ENID TO
GUTHRIE TO CHANDLER WILL BE NEAR OF JUST BELOW FREEZING...
29 TO 33 DEGREES...THROUGH WEDNESDAY MORNING. IF PRECIPITATION
WERE TO GET THIS FAR NORTH...A LIGHT WINTRY MIX OF MAINLY LIGHT
FREEZING RAIN AND/OR LIGHT SLEET COULD OCCUR. CONFIDENCE IN THIS
SCENARIO REMAINS LOW...ESPECIALLY MOST MODEL RUNS INCLUDING THE
00Z NAM DEPICTING THE HEAVIEST PRECIPITATION WELL SOUTH OF THESE
LOCATIONS. THUS...DID NOT MENTION AT THIS TIME. EVEN IF THIS
WINTRY MIX OCCURRED...TRAVEL IMPACTS WOULD BE VERY UNLIKELY DUE TO
WARMER ROAD SURFACE TEMPERATURES FROM RECENT WARM TEMPERATURES.
PRODUCTS HAVE BEEN UPDATED.
MBS
&&
.PREV DISCUSSION... /ISSUED 509 PM CST TUE DEC 16 2014/
AVIATION...
0Z TAFS... VFR/MVFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD.
RAIN CHANCES WILL BEGIN WED MORNING AND CONTINUE THROUGHOUT THE
DAY. ISOLATED THUNDERSTORMS WILL ALSO BE POSSIBLE WED AFTN WITH
MOST LIKELY LOCATIONS BEING KOKC/KOUN/KLAW/KSPS AND POINTS
SOUTHEAST. HOWEVER... THUNDERSTORMS EXPECTED TO BE ISOLATED
ENOUGH THAT WILL LEAVE A MENTION OUT OF TAFS FOR NOW.
PREV DISCUSSION... /ISSUED 238 PM CST TUE DEC 16 2014/
DISCUSSION...
MID-LEVEL MOISTURE FROM THE GULF WILL BEGIN POURING INTO THE
REGION TONIGHT. WITH SOME ISENTROPIC LIFT AND AN APPROACHING
SHORTWAVE...RAIN CHANCES WILL INCREASE THROUGH THE DAY TOMORROW.
SLIGHT RAIN CHANCES WILL CONTINUE INTO THURSDAY BEFORE ANOTHER
SYSTEM MAKES ITS WAY INTO THE AREA. KEPT A MENTION OF SNOW ACROSS
NORTHERN COUNTIES OVERNIGHT WEDNESDAY NIGHT...BUT CONFIDENCE IN
ANY FROZEN PRECIP IS LOW. RAIN AND DRIZZLE ARE MORE LIKELY.
THE MAIN TROUGH APPROACHES FRIDAY...BRINGING RAIN CHANCES TO
SOUTHERN PARTS OF THE CWA. MODELS CONTINUE TO SHOW A DRIER
THURSDAY AND FRIDAY...KEEPING THE MOISTURE FARTHER SOUTH. BROUGHT
POPS DOWN ACCORDINGLY.
BY THE WEEKEND...ANY PRECIP SHOULD BE OUT OF THE AREA. MODELS ARE
STARTING TO COME INTO BETTER ALIGNMENT...SHOWING ANOTHER TROUGH
COMING THROUGH MONDAY OF NEXT WEEK. THOUGH...AS OF YET...THIS
SYSTEM LOOKS TO BE DRY.
TEMPERATURES SHOULD BE SEASONABLY COOL THROUGHOUT THE FORECAST
PERIOD...WITH A GRADUAL WARM UP IN THE BEGINNING OF NEXT WEEK.
MAD
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 32 42 37 48 / 10 50 50 30
HOBART OK 34 42 36 48 / 10 50 30 20
WICHITA FALLS TX 37 44 40 55 / 10 60 30 10
GAGE OK 31 43 33 43 / 10 30 30 20
PONCA CITY OK 28 40 33 42 / 10 40 60 30
DURANT OK 33 44 39 52 / 0 70 70 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
17/25
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 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 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 HOUSTON/GALVESTON TX
920 PM CST TUE DEC 16 2014
.DISCUSSION...
MAIN ISSUE TONIGHT IS THE INCREASING CLOUD COVER AS ISENTROPIC
UPGLIDE INTENSIFIES AND SHIFTS EASTWARD. DECK OF 4000-7000FT
SPREADING IN FROM THE SOUTHWEST AND CI ABOVE THAT SPREADING EAST.
THIS WILL MAKE THE TEMPERATURE FORECAST FOR TONIGHT A LITTLE
TRICKY. ATTM THINK THAT UPPER 30S SHOULD OCCUR IN THE DRIER
NORTHEASTERN AREAS AND THAT CLOUD COVER SHOULD HELP TO ARREST THE
FALL IN THE WEST SO HAVE MADE SOME MINOR TWEAKS TO THE FORECAST
WITH THIS IN MIND. RAIN CHANCES SHOULD HOLD OFF UNTIL MID MORNING
AND EVEN THEN SHOULD BE LIGHT DRIZZLE OR SPRINKLES IN THE FAR
WEST AS CLOUD COVER DEEPENS.
45
&&
.PREV DISCUSSION... /ISSUED 540 PM CST TUE DEC 16 2014/
AVIATION...
VFR CONDITIONS EXPECTED TO PREVAIL THROUGH WEDNESDAY AFTERNOON...
WITH THE MAIN AVIATION CONCERN CENTERING AROUND THE TIMING OF MVFR
CEILINGS LATER IN THE TAF PERIOD.
NORTHERLY WINDS AROUND 5 TO 10 KNOTS WILL VEER TO THE SOUTHEAST
AT THE TERMINALS THROUGH THE PERIOD AS SURFACE HIGH PRESSURE
BUILDS FARTHER INTO THE REGION. LOW LEVEL MOISTURE WILL ALSO
INCREASE...WITH VFR CEILINGS AROUND 5-6KFT IN PLACE BY 17/12Z.
ADDITIONAL COLUMN SATURATION WILL ALLOW CEILINGS TO LOWER
THROUGHOUT THE DAY...WITH MVFR CEILINGS IN PLACE FOR THE HOUSTON
TERMINALS AND AREAS SOUTH AROUND 21Z. WARM AIR ADVECTION WILL ALSO
ENABLE LIGHT RAIN OR DRIZZLE AT THE TERMINALS TOWARDS THE END /AND
AFTER THE END/ OF THE TAF PERIOD...WITH BEST CHANCES BEFORE 18/00Z
AT COLLEGE STATION. LOW PROBABILITY OF OCCURRENCE AT THE HOUSTON
TERMINALS PRECLUDES MENTION AT THIS TIME...BUT -RA/DZ DEVELOPMENT
LOOKS TO HAPPEN BETWEEN 18/00Z AND 18/06Z.
HUFFMAN
PREV DISCUSSION... /ISSUED 313 PM CST TUE DEC 16 2014/
DISCUSSION...
THE BEST DAY OF THE WEEK WEATHER-WISE AS THE MAJORITY OF THE REGION
IS UNDER CLEAR SKIES...AFTERNOON TEMPERATURE READINGS WARMING INTO
THE SEASONABLE LOWER TO MIDDLE 60S UNDER A LIGHT NORTH WIND. AS
THE 1030 MB SURFACE HIGH...CURRENTLY CENTERED OVER THE CENTRAL RED
RIVER VALLEY...TRAVELS NORTHEAST OVER THE NEXT 24 HOURS WINDS WILL
VEER MORE EASTERLY TO EVENTUAL SOUTHEASTERLY WEDNESDAY NIGHT. THIS
WILL AID IN DRAWING UP MORE MOISTURE RICH AIR INTO THE FORECAST AREA.
GREATER THAN 50% LOW TO MID LEVEL RH VALUES ARE CURRENTLY BEING PROGGED
BY THE GFS AND NAM TO ADVANCE UPON THE WESTERN COUNTIES THROUGH THE
EARLY MORNING HOURS. THIS WILL BE THE FLY IN THE OINTMENT THAT REGULATES
WESTERN CWA MINIMUM TEMPERATURES...CLOUDS WILL KEEP MINS TO THE MID
40S WITH SLOW-ADVANCING CLOUDS FROM THE WEST ALLOWING THESE SITES
TO FALL BELOW 40F. HAVE SPLIT THE DIFFERENCE AND WENT WITH THE AVERAGE
LOWER 40S OUT WEST...MIDDLE 40S ELSEWHERE OVER THE INTERIOR...CLEARER
SKIES OVER THE LAKE LIVINGSTON AREA WILL AFFORD THE UPPER 30S.
A WARM AIR ADVECTION PATTERN SETS UP WEDNESDAY THROUGH THURSDAY THAT
WILL GRADUALLY DETERIORATE CONDITIONS FROM WEST TO EAST. INCREASING
OVERCAST THROUGH WEDNESDAY AFTERNOON WILL LEAD TO EITHER DRIZZLE
OR VERY LIGHT RAIN SHOWERS FORMING OVER THE WEST CENTRAL ZONES AND
ADVANCING EASTWARD THROUGH THE OVERNIGHT EARLY THURSDAY MORNING
HOURS. AS OVERNIGHT TEMPERATURES FALL INTO THE LOWER TO MIDDLE 50S
THIS WILL CLOSE THE DEW POINT DEPRESSION ENOUGH TO SATURATE THE
LOWER LEVELS...LOWERING CLOUDS BASES AND INTRODUCING FOG WITHIN
LIGHT PRECIPITATION. A MURKY THURSDAY MORNING WILL BE THE PRECURSOR
TO AN OVERCAST DAY WITH HIGH PROBS OF SCATTERED SHOWERS WITH
ISOLATED THUNDER AS A WEAK SURFACE BOUNDARY HANGS UP OVER THE CWA.
EASTERN TEXAS MIGHT ALSO FALL UNDER THE RR QUAD OF A PRONOUNCED
JET JUST DOWNSTREAM OF THE NEXT MAJOR WEATHER MAKER FRIDAY.
THIS FEATURE BEING A WESTERN LONG WAVE TROUGH THAT WILL PASS OVER
THE REGION DURING THE DAY FRIDAY...INCREASING AREAWIDE POPS TO
LIKELY FOR SHOWERS AND STORMS. AS OF NOW...THE GFS AND ECMWF
SOLUTIONS DEVELOP A COASTAL TROUGH OR CLOSED OFF LOW THAT WOULD
MAKE FOR A MORE ACTIVE DAY...QPF RANGING FROM AROUND A HALF OF AN
INCH AROUND THE COAST TO SLIGHTLY OVER TWO INCHES OVER OUR NORTHERN
ZONES. ALL DEPENDENT UPON THE POSITIONING OF THE UPPER TROUGH
AND/OR ATTENDANT SURFACE TROF/LOW ON WHERE THE HIGHEST RAIN
FALLS...BUT NWP PROGS AND WPC DO PLACE THE HIGHEST DAY 3 RAINFALL
OVER THE NORTHERN HALF OF THE FORECAST AREA. AGGRESSIVE COLD
FRONTAL PASSAGE SATURDAY WILL WHISK ALL CONVECTION EAST BY SUNRISE
SATURDAY. THE BACKING SURFACE HIGH WILL ELONGATE BACK INTO THE
REGION FROM THE MIDWESTERN U.S. AND PRODUCE A PERSISTENT NE-E
FLOW THROUGH EARLY CHRISTMAS WEEK. THE CHRISTMAS DAY OUTLOOK HAS
LOWERING WESTERN TEXAS PRESSURES MAINTAINING A LIGHT TO MODERATE
ONSHORE FLOW...LOW RAIN CHANCES WITH SEASONABLE TEMPERATURE TRENDS.
31
MARINE...
HIGH PRESSURE WILL BUILD INTO THE SOUTHERN PLAINS THIS EVENING AND
WINDS WILL SUBSIDE AND GENTLY VEER TO THE NE AS THE HIGH DRIFTS
EAST. ONSHORE WINDS ARE EXPECTED TO RETURN WEDNESDAY AFTERNOON AS
THE HIGH MOVES FURTHER EAST. ONSHORE WINDS WILL PERSIST THROUGH
FRIDAY MORNING AS LOW PRESSURE DEVELOPS OVER SOUTH TEXAS AND
SCOOTS UP THE COAST ON FRIDAY AFTERNOON. A COLD FRONT WILL CROSS
THE COAST FRIDAY EVENING AND STRONG OFFSHORE WINDS WILL DEVELOP IN
THE WAKE OF THE FRONT. A SMALL CRAFT ADVISORY MAY BE REQUIRED FRI
NIGHT INTO SATURDAY. WINDS WILL BEGIN TO RELAX BY SAT EVENING AS
HIGH PRESSURE SETTLES OVER THE CENTRAL PLAINS. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 43 54 52 65 57 / 0 40 50 30 80
HOUSTON (IAH) 44 59 55 70 60 / 0 20 50 50 60
GALVESTON (GLS) 53 62 61 69 63 / 0 20 40 40 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...45
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
540 PM CST TUE DEC 16 2014
.AVIATION...
VFR CONDITIONS EXPECTED TO PREVAIL THROUGH WEDNESDAY AFTERNOON...
WITH THE MAIN AVIATION CONCERN CENTERING AROUND THE TIMING OF MVFR
CEILINGS LATER IN THE TAF PERIOD.
NORTHERLY WINDS AROUND 5 TO 10 KNOTS WILL VEER TO THE SOUTHEAST
AT THE TERMINALS THROUGH THE PERIOD AS SURFACE HIGH PRESSURE
BUILDS FARTHER INTO THE REGION. LOW LEVEL MOISTURE WILL ALSO
INCREASE...WITH VFR CEILINGS AROUND 5-6KFT IN PLACE BY 17/12Z.
ADDITIONAL COLUMN SATURATION WILL ALLOW CEILINGS TO LOWER
THROUGHOUT THE DAY...WITH MVFR CEILINGS IN PLACE FOR THE HOUSTON
TERMINALS AND AREAS SOUTH AROUND 21Z. WARM AIR ADVECTION WILL ALSO
ENABLE LIGHT RAIN OR DRIZZLE AT THE TERMINALS TOWARDS THE END /AND
AFTER THE END/ OF THE TAF PERIOD...WITH BEST CHANCES BEFORE 18/00Z
AT COLLEGE STATION. LOW PROBABILITY OF OCCURRENCE AT THE HOUSTON
TERMINALS PRECLUDES MENTION AT THIS TIME...BUT -RA/DZ DEVELOPMENT
LOOKS TO HAPPEN BETWEEN 18/00Z AND 18/06Z.
HUFFMAN
&&
.PREV DISCUSSION... /ISSUED 313 PM CST TUE DEC 16 2014/
DISCUSSION...
THE BEST DAY OF THE WEEK WEATHER-WISE AS THE MAJORITY OF THE REGION
IS UNDER CLEAR SKIES...AFTERNOON TEMPERATURE READINGS WARMING INTO
THE SEASONABLE LOWER TO MIDDLE 60S UNDER A LIGHT NORTH WIND. AS
THE 1030 MB SURFACE HIGH...CURRENTLY CENTERED OVER THE CENTRAL RED
RIVER VALLEY...TRAVELS NORTHEAST OVER THE NEXT 24 HOURS WINDS WILL
VEER MORE EASTERLY TO EVENTUAL SOUTHEASTERLY WEDNESDAY NIGHT. THIS
WILL AID IN DRAWING UP MORE MOISTURE RICH AIR INTO THE FORECAST AREA.
GREATER THAN 50% LOW TO MID LEVEL RH VALUES ARE CURRENTLY BEING PROGGED
BY THE GFS AND NAM TO ADVANCE UPON THE WESTERN COUNTIES THROUGH THE
EARLY MORNING HOURS. THIS WILL BE THE FLY IN THE OINTMENT THAT REGULATES
WESTERN CWA MINIMUM TEMPERATURES...CLOUDS WILL KEEP MINS TO THE MID
40S WITH SLOW-ADVANCING CLOUDS FROM THE WEST ALLOWING THESE SITES
TO FALL BELOW 40F. HAVE SPLIT THE DIFFERENCE AND WENT WITH THE AVERAGE
LOWER 40S OUT WEST...MIDDLE 40S ELSEWHERE OVER THE INTERIOR...CLEARER
SKIES OVER THE LAKE LIVINGSTON AREA WILL AFFORD THE UPPER 30S.
A WARM AIR ADVECTION PATTERN SETS UP WEDNESDAY THROUGH THURSDAY THAT
WILL GRADUALLY DETERIORATE CONDITIONS FROM WEST TO EAST. INCREASING
OVERCAST THROUGH WEDNESDAY AFTERNOON WILL LEAD TO EITHER DRIZZLE
OR VERY LIGHT RAIN SHOWERS FORMING OVER THE WEST CENTRAL ZONES AND
ADVANCING EASTWARD THROUGH THE OVERNIGHT EARLY THURSDAY MORNING
HOURS. AS OVERNIGHT TEMPERATURES FALL INTO THE LOWER TO MIDDLE 50S
THIS WILL CLOSE THE DEW POINT DEPRESSION ENOUGH TO SATURATE THE
LOWER LEVELS...LOWERING CLOUDS BASES AND INTRODUCING FOG WITHIN
LIGHT PRECIPITATION. A MURKY THURSDAY MORNING WILL BE THE PRECURSOR
TO AN OVERCAST DAY WITH HIGH PROBS OF SCATTERED SHOWERS WITH
ISOLATED THUNDER AS A WEAK SURFACE BOUNDARY HANGS UP OVER THE CWA.
EASTERN TEXAS MIGHT ALSO FALL UNDER THE RR QUAD OF A PRONOUNCED
JET JUST DOWNSTREAM OF THE NEXT MAJOR WEATHER MAKER FRIDAY.
THIS FEATURE BEING A WESTERN LONG WAVE TROUGH THAT WILL PASS OVER
THE REGION DURING THE DAY FRIDAY...INCREASING AREAWIDE POPS TO
LIKELY FOR SHOWERS AND STORMS. AS OF NOW...THE GFS AND ECMWF
SOLUTIONS DEVELOP A COASTAL TROUGH OR CLOSED OFF LOW THAT WOULD
MAKE FOR A MORE ACTIVE DAY...QPF RANGING FROM AROUND A HALF OF AN
INCH AROUND THE COAST TO SLIGHTLY OVER TWO INCHES OVER OUR NORTHERN
ZONES. ALL DEPENDENT UPON THE POSITIONING OF THE UPPER TROUGH
AND/OR APPENDANT SURFACE TROF/LOW ON WHERE THE HIGHEST RAIN
FALLS...BUT NWP PROGS AND WPC DO PLACE THE HIGHEST DAY 3 RAINFALL
OVER THE NORTHERN HALF OF THE FORECAST AREA. AGGRESSIVE COLD
FRONTAL PASSAGE SATURDAY WILL WHISK ALL CONVECTION EAST BY SUNRISE
SATURDAY. THE BACKING SURFACE HIGH WILL ELONGATE BACK INTO THE
REGION FROM THE MIDWESTERN U.S. AND PRODUCE A PERSISTENT NE-E
FLOW THROUGH EARLY CHRISTMAS WEEK. THE CHRISTMAS DAY OUTLOOK HAS
LOWERING WESTERN TEXAS PRESSURES MAINTAINING A LIGHT TO MODERATE
ONSHORE FLOW...LOW RAIN CHANCES WITH SEASONABLE TEMPERATURE TRENDS.
31
MARINE...
HIGH PRESSURE WILL BUILD INTO THE SOUTHERN PLAINS THIS EVENING AND
WINDS WILL SUBSIDE AND GENTLY VEER TO THE NE AS THE HIGH DRIFTS
EAST. ONSHORE WINDS ARE EXPECTED TO RETURN WEDNESDAY AFTERNOON AS
THE HIGH MOVES FURTHER EAST. ONSHORE WINDS WILL PERSIST THROUGH
FRIDAY MORNING AS LOW PRESSURE DEVELOPS OVER SOUTH TEXAS AND
SCOOTS UP THE COAST ON FRIDAY AFTERNOON. A COLD FRONT WILL CROSS
THE COAST FRIDAY EVENING AND STRONG OFFSHORE WINDS WILL DEVELOP IN
THE WAKE OF THE FRONT. A SMALL CRAFT ADVISORY MAY BE REQUIRED FRI
NIGHT INTO SATURDAY. WINDS WILL BEGIN TO RELAX BY SAT EVENING AS
HIGH PRESSURE SETTLES OVER THE CENTRAL PLAINS. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 43 54 52 65 57 / 0 40 50 30 80
HOUSTON (IAH) 44 59 55 70 60 / 0 20 50 50 60
GALVESTON (GLS) 53 62 61 69 63 / 0 20 40 40 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
524 PM CST TUE DEC 16 2014
.AVIATION...
LOW LEVEL MOISTURE EXPANDING NORTH A LITTLE AHEAD OF SCHEDULE
LEADING TO A DECK NEAR 4000 FEET ABOVE THE GROUND AT KLBB AND SOON
TO SPREAD TO KPVW. SATELLITE AND RAP SOLUTIONS SUGGEST THERE MAY
BE A BREAK SKIRTING CLOSE TO BOTH KLBB AND KPVW BY MID EVENING BUT
UNCLEAR IF CEILING WILL BREAK...CHOSE TO KEEP A CONSTANT LAYER FOR
NOW. THIS LAYER SHOULD SPREAD INTO KCDS AS WELL BY MID EVENING.
SATELLITE SHOWS A WELL DEFINED IMPULSE CROSSING NORTHERN BAJA
CALIFORNIA AT THIS TIME AND NOW FORECAST TO LIFT INTO THE WESTERN
SOUTH PLAINS BY MID TO LATE WEDNESDAY MORNING. BOTH RAP AND
WRF/NAM NOW DEPICT MODEST ISENTROPIC LIFT AND LOWERING OF CLOUD
DECKS FOR KPVW AND KLBB NEAR OR JUST AFTER SUNRISE WEDNESDAY...AS
WELL AS SHOWERS DEVELOPING NEARBY. WE WILL WATCH SOLUTION TRENDS
ON THIS AND DECIDE BY THE 06Z TAF IF SHOWERS AND A CLOUD DECK
LOWERING TO NEAR THE BOTTOM OF MVFR LEVELS WORTHY TO INCLUDE FOR
THE NEXT ISSUANCE. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 300 PM CST TUE DEC 16 2014/
SHORT TERM...
INCREASING LOW LEVEL MOISTURE ADVECTION AHEAD OF AN UPPER TROUGH...
LOCATED JUST OFF THE SRN CALI/BAJA CALI COAST AS OF EARLY AFTN...TO
SPREAD STRATUS ACROSS THE FCST OVERNIGHT. THIS MAY END UP OCCURRING
MORE QUICKLY THAN PREVIOUSLY ANTICIPATED AS A BATCH LOW CLOUDS
CONTINUES TO MOVE NWD THROUGH THE PERMIAN BASIN WITH LITTLE HINT
ATTM OF DISSIPATING THIS AFTN. THE MAIN UPPER TROUGH PROGGED TO HOLD
BACK ACROSS THE WRN CONUS INTO WEDNESDAY NIGHT BEFORE DAMPENING
SIGNIFICANTLY AND EJECTING EWD THURSDAY. BEFORE THEN AN INITIAL
SHORT WAVE TROUGH PROGGED TO EJECT ACROSS THE HIGH PLAINS AND AS
THIS UPPER TROUGH APPROACHES CHANCES FOR LIGHT RAIN SHOWERS WILL
INCREASE. WRF-NAM AND ITS ASSOCIATED MOS GUIDANCE WITH POPS CLOSER
TO 30 PCT NOT COMPLETELY UNFOUNDED...BUT APPEARS TO PLAY INTO THE
MODEL BIAS OF OVERPRODUCING LIGHT PRECIP WITH ABUNDANT LOW LEVEL
MOISTURE IN PLACE. ALSO...LAST SEVERAL SYSTEMS HAVE BEEN
DISAPPOINTMENTS RELATIVE TO THE MODEL PROGS AND MOS OUTPUT. THAT
SAID...PREVIOUS FCST LOOKS FINE ATTM WITH SLIGHT CHANCE POPS EAST
AFTER 12Z WEDNESDAY. TEMPS A LESSER CONCERN WITH A RELATIVELY MILD
NIGHT NEAR OR JUST ABOVE MOS LOOKING GOOD. HIGHS WEDNESDAY A BIT
TRICKY AND WILL DEPEND MUCH ON HOW QUICKLY SKIES CLEAR BEHIND THE
TROUGH. SOME SORT OF BLEND BETWEEN MET AND MAV MOS NUMBERS WITH A
SLIGHT NUDGE TO THE WARMER END IS REASONABLE ATTM.
LONG TERM...
A NEG TILTED SHORTWAVE WILL BE POSITIONED OVER THE FA EARLY THURSDAY
WITH MOST OF ITS ENERGY PLACED JUST TO OUR EAST. THE SHORTWAVE WILL
BE QUICKLY KICKED OUT OF THE AREA BY AN APPROACHING TROF FROM THE
WEST. OVERALL MODELS CONTINUE TO HAVE A LESS AMPLIFIED TROF BY
FRIDAY WITH THE EXCEPTION OF THE NAM AND CMC WHICH HAVE A DEEPER AND
SHARPER TROF. MINUS THE CMC...THE GLOBAL MODELS APPEAR TO BE
HANDLING THE TROF BETTER IN THE SYNOPTIC SCALE. THE BIGGER
DIFFERENCES ARE WITH MOISTURE RETURN/AVAILABILITY. THE GFS IS
SOMEWHAT OF AN OUTLIER HAVING A DRY FORECAST DESPITE TROPICAL
MOISTURE FLOWING IN FROM THE PACIFIC. FOR NOW POPS HAVE BEEN KEPT IN
FOR FRIDAY AS LIFT AND MOISTURE SHOULD BE SUFFICIENT ENOUGH FOR
PRECIP. ONE OF THE BIGGER QUESTIONS FOR THIS PERIOD IS PRECIP TYPE.
MOST OF THE FA SHOULD SEE LIQUID PRECIP. THE EXCEPTION TO THAT WOULD
BE ACROSS OUR NORTHWESTERN ZONES WHERE FORECAST SOUNDINGS SHOW TEMPS
ALOFT COOLING ENOUGH TO PRODUCE SNOW AS THE AXIS OF THE TROF MOVES
OVERHEAD FRIDAY MORNING. SURFACE TEMPS SHOULD DROP TO BELOW FREEZING
BY THIS TIME...HOWEVER LITTLE TO NO ACCUMULATION WOULD BE EXPECTED
AS SOIL TEMPS WOULD HAVE NO TIME TO RESPOND AND WOULD STAY ABOVE
FREEZING. THIS TROF WILL QUICKLY PUSH EAST BY SATURDAY WHILE ANOTHER
TROF...THIS ONE DEEPER THAN ITS PREDECESSOR...MOVES INTO THE REGION.
SOME SHOWERS WILL STILL BE POSSIBLE SUNDAY NIGHT WITH THIS SYSTEM
BUT WOULD MOST LIKELY BE LIGHT AS LIFT WILL BE RELATIVELY WEAK DUE
TO THE POS TILT OF THE TROF. THE TROF WILL GIVE WAY TO NORTHWESTERLY
FLOW BY EARLY NEXT WEEK WHICH SHOULD HELP KEEP TEMPS AROUND SEASONAL
AVERAGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 28 53 30 53 29 / 10 10 0 10 30
TULIA 32 48 33 51 31 / 10 10 0 10 30
PLAINVIEW 32 50 33 54 32 / 10 10 0 10 30
LEVELLAND 35 57 33 58 32 / 10 10 0 10 30
LUBBOCK 35 55 35 58 34 / 10 10 0 10 30
DENVER CITY 36 58 35 60 35 / 10 10 0 10 30
BROWNFIELD 36 57 35 59 34 / 10 10 0 10 30
CHILDRESS 33 47 36 53 36 / 10 20 10 10 30
SPUR 35 51 37 59 35 / 10 20 10 10 40
ASPERMONT 38 52 39 62 38 / 10 20 10 10 40
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/05
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
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.
&&
$$
/
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
824 PM MST TUE DEC 16 2014
.UPDATE...
ISSUED AT 813 PM MST TUE DEC 16 2014
LATEST RADAR LOOP SHOWS A BAND OF LIGHT SNOW SHOWERS LIFTING INTO
THE SOUTHERN NE PANHANDLE FROM NORTHEAST CO. THIS APPEARS TO BE
ASSOCIATED WITH A WEAK MIDLVL DISTURBANCE TRAVERSING THE CENTRAL
HIGH PLAINS ATTM. WITH SOME BANDING OWING TO WEAK FRONTOGENESIS
AROUND H7...COULD SEE A DUSTING OF SNOW ALONG AND SOUTH OF THE I80
CORRIDOR IN NE TONIGHT. ADDED A SLIGHT CHANCE OF SNOW THROUGH 06Z
WED. FOG IS STILL A CONCERN FOR THE OVERNIGHT HOURS. LOWEST VSBYS
SO FAR HAVE BEEN ALONG THE PLATTE RIVER WITH MOIST UPVALLEY WINDS
OUT OF THE EAST/SOUTHEAST. THESE AREAS SAW THE MOST SNOW WITH THE
RECENT STORM AS WELL...SO THERE IS PLENTY OF BLYR MOISTURE TO GO
AROUND. THE HRRR STILL SUGGESTS PATCHY FOG WILL LIKELY EXPAND TO
OTHER PARTS OF EAST CENTRAL WY AND THE WESTERN PANHANDLE
OVERNIGHT...EXCEPT ADJACENT TO THE LARAMIE RANGE WHERE THE LLVLS
SHOULD STAY MORE MIXED. LIGHT WEST WINDS AND AMPLE LLVL MOISTURE
COULD RESULT IN PATCHY FOG WEST OF THE LARAMIE RANGE AS WELL.
INCREASED TEMPERATURES A FEW DEGREES OVER THE PANHANDLE WITH LOW
STRATUS MINIMIZING THE POTENTIAL FOR RADIATIONAL COOLING. ONLY
OTHER CHANGES WERE TO ADJUST SKY TRENDS AND THE TIMING/INTENSITY
OF FOG.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 243 PM MST TUE DEC 16 2014
TONIGHT...MOST WIDESPREAD CHALLENGE WILL BE FOG
DEVELOPMENT...INCLUDING AREAL COVERAGE AND VISIBILITIES. WHERE FOG
WAS SLOWEST TO ERODE...FROM TORRINGTON...TO SCOTTSBLUFF AND TO
ALLIANCE...INCLUDING OVER THE SNOWFIELD...3 PM TEMPERATURE AND
DEWPOINT SPREADS ARE ONLY 2 TO 5 DEGREES WITH CLEARING MID LEVEL
SKIES NOTED ON VISIBLE SATELLITE IMAGERY...THUS EXPECT FOG TO
DEVELOP RATHER QUICKLY AND SPREAD OVER AFOREMENTIONED LOCALES IN
THE LATE AFTERNOON AND EARLY EVENING HOURS.
LOW LEVELS AND BOUNDARY LAYER SATURATE UP DECENTLY
OVERNIGHT...ESPECIALLY OVER OUR WESTERN COUNTIES OF CARBON AND
ALBANY...AND MID AFTERNOON TEMPERATURE DEWPOINT SPREADS ARE ONLY
AROUND 7 DEGREES AT RAWLINS AND LARAMIE...ALONG WITH MID LEVEL
CLEARING PROGGED...THUS EXPECT RATHER EXTENSIVE FOG TO DEVELOP LATE
THIS EVENING AND OVERNIGHT ACROSS OUR WESTERN COUNTIES.
NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT MOVES FROM WESTERN WYOMING
THIS AFTERNOON...TO NORTHWEST WYOMING BY MIDNIGHT AND TO CENTRAL
MONTANA BY DAYBREAK...BASED ON SATELLITE AND RADAR TRENDS...EXPECT
INCREASING AREAL COVERAGE OF SNOW SHOWERS THIS EVENING ACROSS OUR
WYOMING COUNTIES...ESPECIALLY OVER AND NEAR THE SNOWY AND SIERRA
MADRE RANGES...WITH A SLOW CESSATION AND DECREASE IN AREAL SNOW
COVERAGE LATE THIS EVENING AND OVERNIGHT. MAY EVEN SEE A FEW
FLAKES ALONG AND EAST OF INTERSTATE 25...THOUGH COVERAGE LOOKS
QUITE MINIMAL.
WEDNESDAY...SPLIT TROUGHS ALOFT MOVE ACROSS OUR REGION WITH THE
BULK OF SNOW AND DEEPER MOISTURE LOCATED OVER COLORADO...THOUGH
OUR SNOWY AND SIERRA MADRE RANGES WILL SEE SCATTERED OROGRAPHIC
SNOW SHOWERS...MOSTLY DRY ELSEWHERE.
WEDNESDAY NIGHT...NORTHERN STREAM SHORTWAVE TROUGH ALOFT MOVES OVER
THE WESTERN DAKOTAS...WITH THE SOUTHERN STREAM SHORTWAVE TROUGH
ALOFT MOVING OVER WESTERN KANSAS...THUS MINIMAL COVERAGE OF SNOW
SHOWERS OVER OUR COUNTIES...MAINLY OVER THE SNOWY AND SIERRA MADRE
RANGES...DRY ELSEWHERE.
THURSDAY...PSEUDO CYCLONIC FLOW ALOFT CONTINUES OVER OUR COUNTIES
WITH ONE SHORTWAVE ALOFT OVER THE FOUR CORNERS WITH MOST OF THAT
SHORTWAVE TROUGH SNOW OVER WESTERN COLORADO...THOUGH WILL SEE SOME
OROGRAPHIC SNOW SHOWERS OVER OUR SNOWY AND SIERRA MADRE RANGES...
DRY ELSEWHERE.
THURSDAY NIGHT...FAST MOVING...MOISTURE STARVED SHORTWAVE TROUGH
ALOFT MOVES ACROSS OUR COUNTIES...THOUGH WITH MINIMAL LOW AND MID
LEVEL MOISTURE...ONLY SOME ISOLATED MOUNTAIN SNOW SHOWERS ON TAP.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 243 PM MST TUE DEC 16 2014
SHORTWAVE TROUGH WILL MOVE OVERHEAD ON FRIDAY UNDER WEAK NORTHWEST
FLOW. MODELS KEEP THE HIGHEST LLVL MOISTURE OVER THE MOUNTAINS THRU
THE DAY WHICH IS REASONABLE IN THIS FLOW PATTERN...SO KEPT SNOW
CHANCES CONFINED TO THE SNOWY AND SIERRA MADRES MOUNTAINS. ANOTHER
WEAK SHORTWAVE TROUGH WILL MOVE THROUGH ON SATURDAY/SATURDAY NIGHT
WITH A SLIGHTLY MORE NORTHERLY TRACK...SO COULD SEE LIGHT SNOW
SHOWERS RETURNING TO THE MOUNTAINS INCLUDING THE NORTHERN LARAMIE
RANGE THROUGH THIS TIME. WINDS ALOFT WILL BEGIN TO INCREASE SUNDAY
AND MONDAY AS A STRONG EASTERN PAC HIGH BUILDS IN FROM THE WEST. THE
STORM TRACK WILL THUS SHIFT OVER THE NORTHERN ROCKIES AND HIGH
PLAINS THROUGH THE EARLY PART OF THE WEEK...WITH WINDY CONDITIONS
AND INCREASING COVERAGE OF SNOW SHOWERS EXPECTED. THE NOSE OF A 150+
KT JET WILL MOVE OVERHEAD MONDAY...WITH A RATHER VIGOROUS VORT MAX
MOVING FROM THE NORTHERN ROCKIES INTO THE CENTRAL PLAINS IN THE LFQ
REGION OF THE JET. STILL LOOKS FAVORABLE FOR MORE WIDESPREAD SNOW
SHOWERS OVER THE CWA ON MONDAY...ESPECIALLY OVER THE MOUNTAINS AND
NORTHERN PLAINS FROM DOUGLAS TO ALLIANCE IN BETTER PROXIMITY TO THE
JET DIFLUENCE AND LIFT FROM THE VORT MAX. THE LLVL GRADIENT WILL
INCREASE IN ADVANCE OF THE WAVE AS THE LEESIDE TROUGH DEEPENS AS
WELL...SO SHOULD ALSO SEE WINDS BECOME MODERATE TO STRONG LATE
SUNDAY THROUGH MONDAY. THE ASSOCIATED COLD FRONT WILL MOVE ACROSS
THE EASTERN PLAINS SOMETIME LATE MONDAY...AND SHOULD STALL HERE
THROUGH TUESDAY. WINDY CONDITIONS WITH CHANCES FOR LIGHT SNOW WILL
CONTINUE OVER THE MOUNTAINS WITH RAIN/SNOW MIX OVER THE PLAINS AS A
RESULT. TEMPS THROUGH THE PERIOD WILL REMAIN AROUND NORMAL FOR THIS
TIME OF YEAR...WITH A SLIGHT BUMP UPWARDS AS DOWNSLOPE WINDS KICK IN
FOR MONDAY AND TUESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 501 PM MST TUE DEC 16 2014
FOG WILL BE THE MAIN AVIATION CONCERN FOR MOST TERMINALS ACROSS
SOUTHEAST WY AND THE WESTERN NE PANHANDLE. LINGERING LIGHT SNOW
SHOWERS SHOULD HAVE LITTLE IMPACT. EXPECT IFR/LIFR CIGS AND VSBYS
TO DEVELOP BETWEEN 03Z AND 06Z AND PERSIST THROUGH THE NIGHT. THE
MOST LIKELY AREA TO SEE LOCALLY DENSE FOG WITH VSBYS LESS THAN ONE
QUARTER OF A MILE WILL BE THE PLATTE RIVER VALLEY WITH LIGHT
UPVALLEY WINDS...INCLUDING BFF. THE PANHANDLE SITES COULD SEE IFR
CONDITIONS WELL INTO THE AFTERNOON ON WED.
&&
.FIRE WEATHER...
ISSUED AT 243 PM MST TUE DEC 16 2014
MINIMAL ISSUES DUE TO PROJECTED HUMIDITIES AND WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLH
SHORT TERM...RUBIN
LONG TERM...RJM
AVIATION...CLH
FIRE WEATHER...RUBIN
AREA FORECAST DISCUSSION
NWS ALBANY NY
1251 AM EST WED DEC 17 2014
.SYNOPSIS...
A WEAK STORM WILL BRING PERIODS OF LIGHT RAIN ALONG WITH
SOME FOG OVERNIGHT. THERE MAY BE POCKETS OF FREEZING RAIN OVER THE
ADIRONDACKS...GREEN MOUNTAINS AND BERKSHIRES. SOME LINGERING RAIN
AND SNOW SHOWERS WILL BE AROUND FOR WEDNESDAY INTO WEDNESDAY
NIGHT...BEFORE DRIER AIR AND SLIGHTLY COLDER TEMPERATURES RETURN TO
THE REGION FOR LATER IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS 1251 AM EST...AN OCCLUDED BOUNDARY IS IN THE PROCESS OF MOVING
ACROSS THE REGION FROM SOUTH TO NORTH. THE PARENT LOW OF THIS
STORM IS LOCATED OVER SOUTHERN ONTARIO...WITH A NEW SURFACE LOW
DEVELOPING ALONG THE STORM/S TRIPLE POINT NEAR NORTH
JERSEY/NYC/LONG ISLAND.
STEADY RAINFALL AHEAD OF THIS BOUNDARY HAS ENDED OVER MOST OF THE
REGION...EXCEPT WESTERN NEW ENGLAND. EVEN THERE...STEADY RAINFALL
LOOKS TO BE EXITING TO THE NORTH AND EAST OVER THE NEXT HOUR OR
TWO. WE WILL KEEP CHC TO LIKELY POPS IN PLACE THROUGH THE
REMAINDER OF THE OVERNIGHT HOURS...AS UPSTREAMS RADAR ARE STILL
SHOWING SOME SCATTERED RAIN SHOWERS THAT MAY WORK ITS WAY INTO OUR
AREA. THE 02Z 3KM HRRR SHOWS ACTIVITY REMAINING OVER EASTERN AREAS
AS WELL THROUGH THE OVERNIGHT HOURS...AS THE STRENGTHENING SFC
LOW NEAR THE COAST WILL HELP TO REDEVELOP RAINFALL FOR AREAS FROM
THE HUDSON RIVER ON EASTWARD.
IN THE MAJORITY OF THE REGION...TEMPS ARE ABOVE FREEZING IN
THE MID TO UPPER 30S. HOWEVER...A FEW LOCATIONS WITHIN SHELTERED
ELEVATED VALLEYS OF SOUTHERN VT...THE SOUTHERN ADIRONDACKS...AND
THE BERKSHIRES...ARE STILL SITTING AT 32 DEGREES. THIS MAY ALLOW
FOR SOME LIGHT FREEZING RAIN IN THOSE ISOLATED LOCATIONS...WITH A
COATING TO A TENTH OF AN INCH OF ICE POSSIBLE THROUGH THE
REMAINDER OF THE OVERNIGHT HOURS. WE HAVE BEEN HANDLING THIS
ISOLATED FREEZING RAIN THREAT WITH SPECIAL WEATHER STATEMENTS AND
UPDATES VIA SOCIAL MEDIA...AS COVERAGE IS TOO SMALL TO WARRANT A
WINTER WEATHER OR FREEZING RAIN ADVISORY. STILL...THERE MAY BE
SOME SLICK SPOTS IN THE USUAL COLDER LOCATIONS...SO CAUTION IS
URGED IF TRAVELING IN THESE LOCATIONS THROUGH THE REMAINDER OF THE
OVERNIGHT HOURS. TEMPS OVERNIGHT LOW TO MAINLY HOLD STEADY CLOSE
TO THEIR CURRENT READINGS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/...
TOMORROW...THE SURFACE WILL LOW WILL BEGIN TO MOVE EAST OF THE GULF
OF MAINE. HOWEVER...THE UPPER AIR LOW WILL STILL BE JUST TO OUR
NORTH WITH A SHORT WAVE TROUGH TO WORK ON THROUGH. PRECIPITATION
WILL TURN MORE SHOWERY BUT PERSIST...ESPECIALLY TO THE EAST OF THE
HUDSON VALLEY. SLIGHTLY COLDER AIR WILL FILTER INTO THE
REGION...FIRST ALOFT...EVENTUALLY TRANSLATING DOWN TO THE SURFACE.
THERE COULD BE A FEW BREAKS OF AFTERNOON SUNSHINE IN THE MID HUDSON
VALLEY WITH HIGHS ONCE AGAIN PEAKING IN THE UPPER 40S. ELSEWHERE
CLOUDS LOOK TO HANG TOUGH WITH HIGHS 40-45 IN THE REMAINING VALLEY
AREAS (INCLUDING THE CAPITAL REGION)...MID OR UPPER 30S ACROSS THE
HIGHER TERRAIN WHERE IT WILL BE COLD ENOUGH FOR SHOWERS OF RAIN TO
MIX WITH OR CHANGE TO SNOW. THERE COULD PERHAPS BE A LITTLE
ACCUMULATIONS ACROSS THE HIGHER TERRAIN OF THE ADIRONDACKS.
TOMORROW NIGHT...THE UPPER AIR LOW AND SHORT WAVE WILL BE PUSHING
OFFSHORE BUT CYCLONIC FLOW WILL PERSIST WITH MORE CLOUDS AND MAINLY
MOUNTAIN SNOW SHOWERS. WITH TEMPERATURES FALLING TO FREEZING OR
LOWER (MID 20S HIGHER TERRAIN)...ANY SNOW SHOWERS WILL STICK AND WE
DO EXPECT MINOR ACCUMULATIONS IN THE MOUNTAINS OF 1-4 INCHES (MAINLY
THE ADIRONDACKS AND SOUTHERN GREENS...BUT OTHER HILLTOPS COULD
CERTAINLY SEE A DUSTING).
THURSDAY WILL BE A BRISK DAY WITH PARTIAL SUNSHINE TO THE LEE OF
THE CATSKILLS...WHILE MOST OTHER AREAS STAY CLOUDY OR MOSTLY CLOUDY
THANKS TO LAKE ENHANCED CLOUDS AND STILL A CYCLONIC FLOW. LAKE
ENHANCED SNOW SHOWERS WILL BE SCATTERED OVER THE HIGHER TERRAIN WITH
PERHAPS A LITTLE MORE ADDITIONAL ACCUMULATIONS. VALLEY AREAS SHOULD
SEE NOTHING MORE THAN FLURRIES OR A FEW LIGHT SHOWERS OR RAIN OR
SNOW.
HIGH TEMPERATURES WILL BE AROUND 40 IN THE VALLEYS...LOWER TO MID
30S ACROSS THE HIGHER TERRAIN. THE WIND WILL BE OUT OF THE WEST
10-15 MPH WITH SOME GUSTS TO 25 MPH ACROSS THE HIGHER
TERRAIN...MOHAWK VALLEY AND CAPITAL REGION.
THURSDAY NIGHT AND FRIDAY...SHOULD BE MAINLY DRY...CONTINUED BRISK.
ANY SHOWERS SHOULD BE MAINLY CONFINED TO THE HIGHER TERRAIN PERHAPS
ADDING ANOTHER INCH OR SO IN SPOTS. VALLEYS WILL BE VARIABLY CLOUDY
WITH SOME PARTIAL CLEARING AT TIMES. LOWS THURSDAY NIGHT WILL BE IN
THE 20S. HIGHS FRIDAY WILL BE IN THE MID TO UPPER 30S IN THE
VALLEYS...MID 30S TO LOWER 30S ACROSS THE HIGHER TERRAIN. THESE
VALUES ARE ABOUT RIGHT ON THE MARK FOR MID DECEMBER.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
LOOKING AT DRY WEATHER TO START AND END THE LONG TERM PERIOD AS
HIGH PRESSURE DOMINATES FRIDAY INTO SATURDAY...AND AGAIN MONDAY INTO
TUESDAY. IN BETWEEN...MEDIUM RANGE GUIDANCE CONTINUES TO DEVELOP A
COASTAL LOW OFF THE EAST COAST THIS WEEKEND...HOWEVER THERE IS MUCH
UNCERTAINTY IN THE FORECAST AS THE MODELS ARE NOT OFFERING
MODEL-TO-MODEL OR RUN-TO-RUN CONSISTENCY. THERE IS A LARGE SPREAD IN
THE ENSEMBLE GUIDANCE REGARDING THE TIMING...TRACK AND STRENGTH OF
THE LOW...SO HAVE FAVORED GUIDANCE FROM THE WEATHER PREDICTION
CENTER TO ENSURE FORECAST CONSISTENCY. WITH SUCH UNCERTAINTY IN THE
FORECAST...HAVE ONLY FORECAST CHANCE POPS SATURDAY NIGHT INTO SUNDAY
NIGHT...WITH THE HIGHEST POPS ON SUNDAY AND ACROSS SOUTHERN AREAS.
TEMPERATURE WISE...LOWS FRIDAY NIGHT WILL BE IN THE TEENS TO LOWER
20S. HIGHS SATURDAY IN THE UPPER 20S TO MID 30S. LOWS SATURDAY NIGHT
THROUGH MONDAY NIGHT WILL BE IN THE UPPER TEENS AND 20S. HIGHS
SUNDAY THROUGH TUESDAY GENERALLY IN THE UPPER 20S AND 30S.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
IFR CONDITIONS TO PREVAIL THROUGH THE OVERNIGHT INTO WEDNESDAY
MORNING AS AN OCCLUDED BOUNDARY GRADUALLY MOVES ACROSS THE REGION.
THE BULK OF THE RAINFALL IS OVER HOWEVER LOW CEILINGS AND POOR
VISIBILITIES WILL CONTINUE WITH RELATIVELY MILD AND MOIST AIR OVER
THE REMAINING SNOWPACK. BY MID TO LATE MORNING CONDITIONS WILL BEGIN
TO SLOWLY IMPROVE...HOWEVER VFR CONDITIONS ARE NOT EXPECTED TO
DEVELOP UNTIL MID TO LATE AFTERNOON AT KPOU AND IN THE EVENING AT
KALB AND KGFL WITH MVFR LINGERS AT KPSF THROUGH 06Z/THURSDAY.
CALM WINDS WILL BECOME WESTERLY ON THURSDAY. THE WESTERLY WINDS WILL
INCREASE IN SPEED BY MID TO LATE AFTERNOON WITH GUSTS EXPECTED AT
KALB AND KPSF.
OUTLOOK...
THU NIGHT-SAT: NO OPERATIONAL IMPACT. NO SIG WX.
SAT NIGHT-SUN: MODERATE OPERATIONAL IMPACT. CHANCE OF SN.
&&
.HYDROLOGY...
NO HYDROLOGIC CONCERNS THROUGH THE REMAINDER OF THE WEEK.
AFTER STEADY RAIN ENDS EARLY THIS MORNING...THE SYSTEM MOVING
THROUGH THE REGION WILL ALLOW FOR SOME ADDITIONAL LIGHT RAIN OR
SNOW SHOWERS LATER TODAY INTO TONIGHT. BASIN AVERAGE PRECIP
AMOUNTS WILL BE LIGHT...GENERALLY LESS THAN A QUARTER OF AN INCH.
ONLY VERY MINOR RISES ARE EXPECTED ON RIVERS AND STREAMS...WITH
MOST RIVER FLOWS EXPECTED TO REMAIN FAIRLY STEADY.
SOME ADDITIONAL LIGHT MOUNTAIN SNOW SHOWERS ARE POSSIBLE THURSDAY
INTO FRIDAY...BUT THESE VERY BE FAIRLY LIMITED AND WON/T HAVE ANY
IMPACT ON AREA WATERWAYS. TEMPERATURES LOOK TO BE A LITTLE COLDER
FOR THURS/FRI...WHICH WILL LIMIT THE AMOUNT OF SNOW MELT THAT
OCCURS. MAINLY DRY WEATHER IS EXPECTED FOR THE WEEKEND...WITH JUST
A LOW CHANCE FOR SOME LIGHT SNOW.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/HWJIV/GJM
NEAR TERM...FRUGIS
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...IAA
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
315 AM CST WED DEC 17 2014
.SHORT TERM...
315 AM CST
THROUGH THURSDAY...
THE SYSTEM THAT BROUGHT A RETURN TO MORE SEASONAL TEMPERATURES IS
NOW CENTERED OVER THE EASTERN GREAT LAKES. THIS UPPER LOW IS
ROTATING AROUND A NOW DEEPER BUT SHEARING UPPER LOW CENTERED OVER
MINNESOTA AND WISCONSIN EARLY THIS MORNING. AT THE LOW-LEVELS THIS
SLOW MOVING PATTERN IS HELPING KEEP COLD AIR ADVECTION IN PLACE.
WHILE NOT PARTICULARLY STRONG FOR DECEMBER...THIS ADVECTION WITHIN
CYCLONIC FLOW HAS HELPED KEEP THE CLOUDS AND EVEN SOME FLURRIES.
EARLY MORNING SATELLITE IMAGERY INDICATES THE BACK EDGE CLEARING
FROM MINNEAPOLIS TO DES MOINES AND MAKING LITTLE PROGRESS. UPSTREAM
00Z SOUNDINGS AND CURRENT ACARS DATA FROM RFD INDICATE THE MOISTURE
DEPTH IS VERY SHALLOW. SO CERTAINLY THERE IS POTENTIAL TO SCATTER
FROM WEST TO EAST TODAY AND HIGH RESOLUTION GUIDANCE AND CONDENSATE
FIELDS DO PAINT THIS PICTURE AS WELL. GIVEN FURTHER STRENGTHENING OF
THE SUBSIDENCE INVERSION ON FORECAST SOUNDINGS ACROSS NORTH CENTRAL
ILLINOIS...HAVE GONE WITH FORECAST SCATTERING THERE BY EARLY
AFTERNOON. A LITTLE MORE TRICKY TOWARD CHICAGO AND NORTHWEST INDIANA
AND HAVE FAVORED THAT AREA REMAINING AT LEAST MOSTLY CLOUDY THROUGH
MUCH OF TODAY.
HIGH TEMPERATURES TODAY LOOK TO BE THEIR COOLEST IN ABOUT A WEEK
WITH UPPER 20S AND LOWER 30S SUPPORTED GIVEN LITTLE DIURNAL CLIMB
EXPECTED. THIS IS JUST A TAD BELOW MID-DECEMBER NORMALS. AS FOR
TONIGHT...LIKE A SONG ON REPEAT...THE CONFIDENCE ON CLOUDS ONCE
AGAIN IS LOW. WHILE SOME AREAS MAY SEE NOT MUCH FOR CLOUDS IN THE
EVENING...HIGH CLOUDS LOOK TO MOVE NORTHWARD OVER THE AREA LATE
TONIGHT. WITH LIGHTER WINDS THE POTENTIAL EXISTS FOR TEMPERATURES TO
DROP INTO THE LOWER TO MID TEENS IN OUTLYING AREAS.
THE GREAT LAKES BROAD UPPER LOW WILL MOVE EAST ON THURSDAY WEAKENING
THE CONFLUENT UPPER FLOW OVER THE FORECAST AREA. THIS WILL HELP A
SOUTHERN STREAM SYSTEM...CENTERED IN EASTERN ARIZONA EARLY THIS
MORNING...TO MAKE SOME INROADS WITH MID-LEVEL WARM AND MOIST
ADVECTION UP TO AT LEAST CENTRAL ILLINOIS AND INDIANA. THIS SHOULD
BRING CLOUDS TO MUCH OF THE AREA. HAVE NOT INCLUDED ANY LIGHT SNOW
IN THE FAR SOUTHERN AREA AT THIS TIME AS THE SUPPORT FOR LIFT STAYS
JUST SOUTH ON MOST GUIDANCE SOLUTIONS.
MTF
&&
.LONG TERM...
315 AM CST
FRIDAY THROUGH TUESDAY...
SURFACE HIGH PRESSURE RIDGING BASICALLY MAINTAINS ITSELF OVER THE
AREA THROUGH THE WEEKEND. THE UPPER PATTERN REMAINS SOMEWHAT SPLIT
WITH A SYSTEM LIKELY ENTIRELY PASSING TO OUR SOUTHEAST ON SATURDAY.
A NORTHERN STREAM UPPER LOW IS FORECAST TO BRING SOME PACIFIC
MOISTURE...MAINLY ALOFT...OVER THE AREA SATURDAY EVENING/OVERNIGHT.
LIFT IS WEAK AND MAINLY FOCUSED NORTH SO DO NOT HAVE ANY
POPS...HOWEVER HAVE INCREASED CLOUD COVER IN THE FORECAST AND WITH
THAT FORECAST MINS ON SATURDAY NIGHT.
THE WEATHER PATTERN ACROSS THE CENTRAL CONUS HAS BEEN CONSISTENTLY
FORECAST BY LONG RANGE MODELS AND ENSEMBLES TO BECOME MORE AMPLIFIED
DURING NEXT WEEK. JUST LOOKING ON HEMISPHERIC WATER VAPOR THIS
MORNING...MULTIPLE SYSTEMS ON ACTIVE JET ARE SEEN ACROSS THE
NORTHERN PACIFIC...SO A PATTERN SHIFT SEEMS LIKELY. THE CONSENSUS OF
GUIDANCE FAVORS AN ANOMALOUS SURFACE REFLECTION TO DEVELOP ACROSS
THE MIDWEST MONDAY INTO TUESDAY...THOUGH AS ONE CAN EXPECT THERE ARE
LARGE DIFFERENCES IN PLACEMENT. HAVE INCREASED FORECAST POPS IN
LINE WITH A SMART GUIDANCE BLEND. GIVEN A CONSENSUS PLACEMENT
THOUGH...IT WOULD SEEM PROFILES WOULD BE MILD ENOUGH FOR MAINLY RAIN
AT FIRST IN OUR AREA. CERTAINLY THIS BECOMES A LOT MORE IN QUESTION
AS THE TROUGH FURTHER AMPLIFIES SUCH AS MODELS SUGGEST INTO
TUESDAY AND CHRISTMAS EVE.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* GUSTY WEST/NORTHWEST WINDS THRU THIS AFTERNOON.
* MVFR CIGS THRU THIS AFTERNOON. CMS
//DISCUSSION...UPDATED 09Z...
MVFR CIGS HAVE TRENDED A BIT LOWER...NOW IN THE 1500FT RANGE. NOT
EXPECTING IFR CIGS...BUT THEY COULD CONTINUE TO LOWER INTO THE
1000-1200FT RANGE OVER THE NEXT FEW HOURS. ALSO A FEW FLURRIES AT
TIMES...BUT NO RESTRICTION TO VIS EXPECTED. CMS
PREVIOUS 06Z DISCUSSION...
MVFR CIGS REMAIN LOCKED IN ACROSS MUCH OF THE REGION AND FORECAST
SOUNDINGS SUGGEST THESE MAY STAY TRAPPED UNDER AN INVERSION
THROUGH MUCH OF WEDNESDAY. CONFIDENCE IS FAIRLY LOW BUT OPTED TO
CONTINUE BKN CIGS UNTIL EVENING. NORTHWEST WINDS 12-16KTS WILL
SLOWLY DIMINISH WEDNESDAY MORNING INTO THE AFTERNOON. GUSTS ARE
STILL IN THE LOWER/MID 20KT RANGE AND THESE TOO WILL SLOWLY
DIMINISH THRU THE DAY...BUT LIKELY NOT COMPLETELY UNTIL LATE IN
THE AFTERNOON. CMS
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM FOR CIGS THRU THE PERIOD.
* HIGH FOR WINDS THRU THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
* THURSDAY THROUGH MONDAY...DRY/VFR.
KJB
&&
.MARINE...
210 AM...LOW PRESSURE NEAR LAKE ONTARIO WILL MOVE EAST AND BE
ABSORBED BY LOW PRESSURE MOVING NORTH ALONG THE NEW ENGLAND COAST.
THIS LOW WILL THEN SLOWLY LIFT NORTHEAST AND DEEPEN OVER THE NEXT
FEW DAYS. A LARGE AREA OF HIGH PRESSURE EXTENDING FROM MANITOBA
INTO THE CENTRAL PLAINS WILL SLOWLY BUILD EAST ACROSS THE LAKES
REGION THURSDAY AND FRIDAY. NORTHWEST WINDS TO 30 KTS IN BETWEEN
THESE TWO SYSTEMS WILL GRADUALLY DIMINISH TONIGHT INTO THURSDAY.
AS THE HIGH DRIFTS ACROSS THE LAKES REGION...THERE WILL BE A
PERIOD OF LIGHT PERHAPS EVEN CALM WINDS FRIDAY NIGHT INTO SATURDAY
NIGHT UNTIL THE HIGH MOVES EAST SUNDAY AND SUNDAY NIGHT AND THE
FLOW TURNS BACK SOUTHERLY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 AM
WEDNESDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 10 AM THURSDAY.
&&
$$
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
312 AM CST Wed Dec 17 2014
.SHORT TERM...(Today)
ISSUED AT 310 AM CST WED DEC 17 2014
A north-south oriented elongated high pressure ridge will edge
eastward toward Illinois today bringing with it a much lighter
surface pressure gradient and subsidence aloft. The result will be
wind speeds and gusts tapering off throughout the day as well as
thinning low cloud cover. Seasonably cold temperatures that arrived
after yesterday`s cold front will continue, with highs today only
around the freezing mark, just a few degrees below normal.
Although cloud cover will thin out through the day, current
indications are that the GFS and HRRR models are too aggressive in
clearing out low level moisture trapped below an inversion based
just below 900 mb. Forecast cloud cover is based more in line with
the NAM which keeps a saturated layer through the early part of
the day, slowly thinning through the afternoon. Meanwhile, periods
of high cloud cover will be arriving in the afternoon as well.
Also watching a band of snow flurries moving southward through Iowa
this morning. This looks as if it will remain west of the central IL
forecast area before the disturbance responsible for it ejects
eastward. This could move through portions of central IL later this
morning, but would be of very little consequence and is a fairly low
probability at this point.
&&
.LONG TERM...(Tonight through Tuesday)
ISSUED AT 310 AM CST WED DEC 17 2014
Upper wave currently pushing through Arizona on track to reach the
southern Plains tonight, before dampening out somewhat as it moves
across Missouri. Forecast soundings off most of the models are
showing the column moistening from the top down overnight, but very
dry air lingers just past sunrise below 800 mb. A short period of
isentropic lift on the 305K plane will move through central Illinois
Thursday morning, coinciding with the moistening of the lower
layers, resulting in a period of light snow across the southwestern
CWA during the morning. Current thinking is only a few tenths from
Rushville through Springfield to the Effingham/Flora areas. The
soundings further northeast toward Peoria and Bloomington generally
never really moisten the lower levels (except for the NAM), and will
keep those areas dry on Thursday.
Model trends for the Friday night/Saturday system continue to shift
more to the south, as the next deepening wave tracks into the lower
Mississippi Valley. Have limited the PoP`s for Friday night and
Saturday morning to areas south of I-70, where accumulations look to
be less than an inch. The ECMWF tries to draw some of the moisture
northward Saturday morning as a separate wave in the northern stream
swings into the Great Lakes region, so have kept some slight chances
during the morning across east central Illinois.
Active period setting up next week, as a broad long wave trough digs
southward through the central U.S. Some timing differences as to the
depth of this wave, with the ECMWF and parallel GFS cutting off a
low over southeast South Dakota and drifting it east, while the
operational GFS waits until mid week to cut off a broad low over the
Midwest. Both solutions yield precipitation as a storm system
organizes just to our northwest. Have continued to concentrate the
precip chances Monday night into Tuesday, mostly rain but perhaps
some snow mixed in across the far north. Will need to watch the
evolution of this closely, with the pre-holiday travel rush
beginning around this time.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
ISSUED AT 1124 PM CST TUE DEC 16 2014
Cloudy skies will continue at all sites through most of the day.
Some clearing is being forecast by some of the models for PIA and
SPI during the afternoon, but rather be cautious and keep some
clouds around into the early evening hours. Even with drier and
cooler temps coming in for tomorrow, the inversion seems to hang
around til evening, trapping some of the moisture in. All clouds
will be MVFR levels, with BMI at IFR now and lasting until around
13z. So will have PIA and SPI scattering out first, but keeping a
4hr TEMPO group during the late morning and early evening hours
for broken MVFR cigs. For the other three sites, BMI, DEC, and
CMI, will maintain cloud cover at all sites into the evening
hours. DEC could scatter out sometime in the evening, but enough
uncertainty at the moment. BMI and CMI might begin to scatter out
around midnight. Northwest winds will continue next 24hrs with
wind speeds decreasing through the period as high pressure ridge
builds into the area. Wind gusts have diminish, but some sites
still maintaining some gusts. These gusts should drop off overnight.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Onton
LONG TERM...Geelhart
AVIATION...Auten
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1127 PM CST TUE DEC 16 2014
.SHORT TERM...
313 PM CST
TONIGHT THROUGH FRIDAY...
FILLING SURFACE LOW WAS OFF TO OUR EAST ACROSS THE CENTRAL GREAT
LAKES THIS AFTERNOON...BENEATH WEAKENING UPPER LEVEL LOW WHICH IS IN
THE PROCESS OF MERGING WITH STRONG DIGGING SHORT WAVE OVER THE UPPER
MISSISSIPPI VALLEY. THIS SECOND WAVE IS PROGGED TO SHEAR SOUTHEAST
ACROSS THE REGION TO THE EAST-SOUTHEAST AS IT REDEVELOPS INTO
REMNANT UPPER TROUGH TO THE EAST. VISIBLE SATELLITE IMAGERY SHOWS
MOST OF THE DEEPER CLOUD COVER HAS MOVED OFF TO THE EAST OF THE
FORECAST AREA...ALONG WITH THE BRUNT OF THE RADAR DETECTABLE
PRECIPITATION. EXPECT SOME PATCHY LIGHT RAIN/DRIZZLE AND PERHAPS A
FEW WET FLURRIES TO GRADUALLY END ACROSS THE AREA OVER THE NEXT FEW
HOURS AS MID-LEVELS CONTINUE TO DRY OUT...WITH 12Z RAOBS FROM
UPSTREAM LOCATIONS SUCH AS ABR AND OAX INDICATIVE OF MUCH DRIER AIR
ABOVE THE BOUNDARY LAYER. OTHERWISE...BLUSTERY WEST-NORTHWEST WINDS
WILL CONTINUE TO PULL COLDER AND DRIER AIR INTO THE AREA TONIGHT
WITH WINDS SLOW TO DIMINISH DUE TO LINGERING SURFACE TROUGHING
ACROSS THE UPPER MIDWEST. THOUGH REMAINING MOISTURE WILL BE SHALLOW
IT APPEARS CLOUD COVER WILL LINGER AT LEAST INTO EARLY WEDNESDAY
BEFORE STRONGER SUBSIDENCE CAN ERODE AND SCATTER CLOUDS MORE
EFFECTIVELY. DESPITE CLOUDS...UPSTREAM TEMPS ACROSS EASTERN IA ARE
ONLY IN THE LOW TO MID 20S AT THIS HOUR...SETTING THE STAGE FOR
CHILLIER TEMPS TONIGHT.
SHEARED MID-LEVEL VORTICITY AXIS FROM SHEARING UPPER MIDWEST SHORT
WAVE REMAINS OVER AREA WEDNESDAY..THOUGH HEIGHT RISES DO DEVELOP AS
THE NEW UPPER LOW DEEPENS OVER NEW ENGLAND. THIS ALLOWS THE GRADIENT
TO WEAKEN MORE QUICKLY ESPECIALLY DURING THE AFTERNOON AND
CONTINUING WEDNESDAY NIGHT AS SURFACE HIGH PRESSURE RIDGE MOVES
SLOWLY INTO WESTERN AND CENTRAL ILLINOIS. GUIDANCE DOES DEPICT A
SHORT WAVE APPROACHING FROM THE SOUTHERN PLAINS/LOWER MISSOURI
VALLEY AREA WEDNESDAY NIGHT...THOUGH THIS WAVE DAMPENS SIGNIFICANTLY
AS IT MOVES INTO THE UPPER RIDGE ACROSS THE MIDWEST. MODEL FORECAST
SOUNDINGS AND TIME-HEIGHT PLOTS INDICATE INCREASING MID-HIGH LEVEL
MOISTURE MAINLY AFTER MIDNIGHT WEDNESDAY NIGHT ACROSS OUR SOUTHWEST.
GUIDANCE (NAM...GFS...ECMWF AND SREF) DOES PRODUCE SOME LIGHT QPF
ACROSS CENTRAL ILLINOIS THURSDAY AS THIS WAVE CONTINUES TO
DEAMPLIFY...THOUGH FORECAST SOUNDINGS INDICATE LOW LEVELS INITIALLY
DRY AND SATURATION APPEARS INCOMPLETE MAKING PRECIP AT THE SURFACE A
LOW PROBABILITY. WEAKENING SURFACE HIGH PRESSURE RIDGE EVENTUALLY
MOVES INTO THE AREA THURSDAY NIGHT AND FRIDAY...ROUNDING OUT A FEW
DAYS OF MAINLY DRY AND SEASONABLY COOLER DAYS.
RATZER
&&
.LONG TERM...
313 PM CST
SATURDAY THROUGH TUESDAY...
ATTENTION TURNS TO A PAIR OF APPROACHING SHORT WAVE TROUGHS IN A
SOMEWHAT SPLIT FLOW REGIME. GUIDANCE HAS TRENDED WEAKER WITH THE
SOUTHERN STREAM DISTURBANCE...WHICH MOVES OUT ACROSS THE SOUTHERN
PLAINS AND GULF COAST STATES THROUGH SATURDAY. DECENT AGREEMENT IN
MODEL SOLUTIONS OF A MORE DIGGING NORTHERN STREAM WAVE COMING OUT OF
THE NORTHERN ROCKIES FRIDAY AND MOVING INTO THE LOWER MISSOURI AND
LOWER OHIO VALLEYS ON SATURDAY. WHILE MAIN SURFACE LOW PRESSURE
DEVELOPS WITH SOUTHERN SYSTEM ALONG THE GULF COAST...NORTHERN STREAM
FORCING DOES INDUCE AN INVERTED TROUGH INTO THE OHIO VALLEY SATURDAY
WHICH CONTINUES TO SUPPORT THE POTENTIAL FOR SOME LIGHT SNOW FROM
SOUTHERN/CENTRAL ILLINOIS INTO NORTHERN INDIANA...POSSIBLY INCLUDING
THE SOUTHEASTERN PART OF OUR CWA AS THE UPPER TROUGH MOVES OVERHEAD.
GUIDANCE STILL FOCUSES GREATER QPF SOUTHEAST OF THE FORECAST AREA...
BUT PRUDENT TO MAINTAIN SLIGHT CHANCES FOR SOME LIGHT ACCUMULATING
SNOW SOUTHEAST OF ABOUT A PONTIAC-VALPARAISO LINE. SURFACE HIGH
PRESSURE RIDGING QUICKLY BUILDS IN BEHIND THIS SYSTEM SATURDAY NIGHT
INTO SUNDAY. TEMPS DO MODERATE TO NORMAL FOR THE WEEKEND...GENERALLY
MID 20S AT NIGHT TO LOW/MID 30S BY DAY.
12Z GFS AND ECMWF RUNS HAVE COME INTO GOOD AGREEMENT IN BRINGING A
MORE AMPLIFIED UPPER TROUGH INTO THE CENTRAL CONUS SUNDAY NIGHT
THROUGH TUESDAY...WITH A STRONGER EMBEDDED SHORT WAVE MOVING ACROSS
THE UPPER MIDWEST LATE MONDAY-TUESDAY WITH DEEPENING LOW PRESSURE
PASSING TO OUR NORTH. THIS RESULTS IN WARMING TEMPERATURES ON
STRENGTHENING SOUTH WINDS...WITH THE POTENTIAL OF RAIN/SNOW CHANGING
TO RAIN BY LATE MONDAY AND CONTINUING TUESDAY AHEAD OF THE
APPROACHING COLD FRONT AS THE LOW MOVES ACROSS THE NORTHERN LAKES.
SOME DETAIL AND SPEED DIFFERENCES DO EXIST BETWEEN MODELS AND MUCH
COULD CHANGE BETWEEN NOW AND MONDAY...THOUGH IT DOES APPEAR THAT
COLDER AIR WOULD SPREAD INTO THE REGION LATER TUESDAY/TUESDAY NIGHT
WITH PRECIPITATION TAPERING OFF AS IT MIXES/CHANGES TO LIGHT SNOW.
COLDER AIR WOULD THEN ARRIVE IN TIME FOR THE CHRISTMAS HOLIDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* GUSTY NORTHWEST WINDS THRU WEDNESDAY AFTERNOON.
* MVFR CIGS THRU WEDNESDAY AFTERNOON. CMS
//DISCUSSION...UPDATED 06Z...
MVFR CIGS REMAIN LOCKED IN ACROSS MUCH OF THE REGION AND FORECAST
SOUNDINGS SUGGEST THESE MAY STAY TRAPPED UNDER AN INVERSION
THROUGH MUCH OF WEDNESDAY. CONFIDENCE IS FAIRLY LOW BUT OPTED TO
CONTINUE BKN CIGS UNTIL EVENING. NORTHWEST WINDS 12-16KTS WILL
SLOWLY DIMINISH WEDNESDAY MORNING INTO THE AFTERNOON. GUSTS ARE
STILL IN THE LOWER/MID 20KT RANGE AND THESE TOO WILL SLOWLY
DIMINISH THRU THE DAY...BUT LIKELY NOT COMPLETELY UNTIL LATE IN
THE AFTERNOON. CMS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM FOR CIGS THRU THE PERIOD.
* HIGH FOR WINDS THRU THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
* THURSDAY THROUGH MONDAY...DRY/VFR.
KJB
&&
.MARINE...
130 PM CST
LOW PRESSURE AND A COLD FRONT HAVE PASSES EAST OF LAKE MICHIGAN AND
WINDS HAVE SHIFTED NORTHWESTERLY. STRONG COLD ADVECTION AND STRONG
PRESSURE RISES AS THE LOW PULLS AWAY TO THE EAST AND HIGH PRESSURE
BUILDS ACROSS THE NORTHERN PLAINS WILL COMBINE TO DRIVE WINDS TO
30KT FOR THE REMAINDER OF THE AFTERNOON THROUGH TONIGHT AND MUCH OF
TOMORROW. THERE IS THE POTENTIAL FOR A FEW GALE FORCE GUSTS...BUT
IN GENERAL...DO NOT EXPECT ENOUGH PREVAILING GALE FORCE WINDS TO
NECESSITATE A GALE WARNING. HOWEVER...A SMALL CRAFT ADVISORY HAS
ALREADY BEEN ISSUED FOR THE NEARSHORE WATERS AND EXPECT THAT TO PLAY
OUT AS CURRENTLY ADVERTISED. THE OVERALL PATTERN WILL BE SLOWLY
PROGRESSIVE...SO BRISK WINDS WILL REMAIN OVER THE LAKE THROUGH
THURSDAY...BUT AS HIGH PRESSURE BEGINS TO BUILD ACROSS THE WESTERN
GREAT LAKES...WINDS SHOULD DROP OFF AND BECOME MORE VARIABLE IN
DIRECTION. HIGH PRESSURE WILL PREVAIL ACROSS THE GREAT LAKES FROM
LATE THURSDAY THROUGH THE WEEKEND...KEEPING WINDS RELATIVELY LIGHT
IN SPEED AND VARIABLE IN DIRECTION. BY EARLY NEXT WEEK...THE HIGH
SHOULD FINALLY PUSH EAST OF LAKE MICHIGAN AS LOW PRESSURE BEGINS TO
DEVELOP OVER THE NORTHERN PLAINS. THIS SHOULD SET UP A PERIOD OF
INCREASING SOUTHERLY WINDS FOR EARLY NEXT WEEK AS A LOW PRESSURE
SYSTEM DEEPENS WHILE CROSSING THE NORTHERN PLAINS AND DRAGGING A
TRAILING COLD FRONT ACROSS THE CENTRAL PLAINS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN
UNTIL 10 AM WEDNESDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN
UNTIL 10 AM THURSDAY.
&&
$$
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
1124 PM CST Tue Dec 16 2014
.UPDATE...
ISSUED AT 901 PM CST TUE DEC 16 2014
Cloudy skies will continue overnight. Even with cooler and drier
air advecting into the area overnight, clouds should still keep
temps from dropping much overnight. Models still trying to bring
in some clearing during the early morning in western Illinois, but
with cyclonic flow, a deep layer of moisture, and an inversion,
believe clouds will hang around the area through late tomorrow.
Gradient will continue to loosen overnight, so gusts should
diminish later tonight, though wind speeds will still be 10-15kts
through early morning. so, current forecast looks good, so no
update needed at this time.
&&
.SHORT TERM...(Tonight)
ISSUED AT 230 PM CST TUE DEC 16 2014
Occluded low pressure system shifts into the eastern Great Lakes
this evening, allowing the gradient to gradually relax and decrease
wind gusts. Latest NAM forecast soundings and HRRR ceiling guidance
suggest lower clouds will persist overnight, and given deep cyclonic
flow and in-building subsidence inversion at 900 MB, believe this
will hold true. Therefore have increased cloud cover overnight.
Lows will be challenging with the full effect of CAA being offset by
insulating effects of cloud cover. Have trended mins 2-3 degrees
warmer than MET/MAV blend, which gives lower 20s west of the IL
River, to mid 20s central/east.
&&
.LONG TERM...(Wednesday through Tuesday)
ISSUED AT 230 PM CST TUE DEC 16 2014
High pressure to settle into the region on Wednesday bringing in dry
with more seasonal temperatures. Forecast soundings...although not
as aggressive as yesterday with the low level moisture...continues
to indicate moisture trapped beneath a subsidence inversion will
keep a bit more cloudiness around the area during the day. Soundings
do show some breaks developing by late morning into the afternoon
hours but just in time to see mid and high level moisture/clouds
stream in ahead of our next weather system for Thursday. That weather
system is expected to spread light snow into parts of extreme west
central through southeast Illinois Thursday morning. Model runs had
been suggesting as the precip spread northeast into a more confluent
flow pattern over the lower Great Lakes coverage would decrease
during the day Thursday. Most of the operational models have backed
off that idea for now and have brought some light precip further north
and east into our area on Thursday so have brought precip chances further
north into the forecast area. Snowfall could accumulate up to 1 inch
from Springfield south Thursday morning before the area begins to
decrease in coverage during the afternoon.
Thursday`s system should be off to our east by evening with our attention
turning to a more significant wave over eastern Texas that will push
a surface low east-northeast across the Gulf Coast states Friday. The
northern periphery of the precip associated with the southern wave will
track over southeast Illinois with once again light snowfall for later
Friday night into Saturday. Current indications suggest an inch or less
for southeast Illinois. High pressure will then shift east into our
area for Sunday into early Monday bringing quiet weather to the region.
Quite a bit of model spread with respect to the system for early next
week, which will be moving southeast out of the Northern Plains and
tracking a strong low pressure system at the surface to our north
Monday. The operational GFS is more progressive with the early week
system and sweeps the cold front thru our area Tuesday afternoon and
evening with little if any southern stream interaction showing up
on the latest model run. In contrast, the latest ECMWF was indicating
a more phased look between the northern and southern streams which
effectively holds up the front pushing across our area later Tuesday
until a surface wave shifts off to our northeast Tuesday night.
This would bring rain on Tuesday, which would eventually change to
snow later in the day and evening as the deepening surface wave shifts
away from our area by Wednesday.
Seems as if each model run has a different solution with respect to
the pattern over the Midwest the first half of next week so not making
any significant changes to the grids at this point for days 7 and 8.
After our brief warm up ahead of the system on Monday and Tuesday, it
turns colder again by midweek.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
ISSUED AT 1124 PM CST TUE DEC 16 2014
Cloudy skies will continue at all sites through most of the day.
Some clearing is being forecast by some of the models for PIA and
SPI during the afternoon, but rather be cautious and keep some
clouds around into the early evening hours. Even with drier and
cooler temps coming in for tomorrow, the inversion seems to hang
around til evening, trapping some of the moisture in. All clouds
will be MVFR levels, with BMI at IFR now and lasting until around
13z. So will have PIA and SPI scattering out first, but keeping a
4hr TEMPO group during the late morning and early evening hours
for broken MVFR cigs. For the other three sites, BMI, DEC, and
CMI, will maintain cloud cover at all sites into the evening
hours. DEC could scatter out sometime in the evening, but enough
uncertainty at the moment. BMI and CMI might begin to scatter out
around midnight. Northwest winds will continue next 24hrs with
wind speeds decreasing through the period as high pressure ridge
builds into the area. Wind gusts have diminish, but some sites
still maintaining some gusts. These gusts should drop off overnight.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Auten
SHORT TERM...25
LONG TERM...Smith
AVIATION...Auten
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
352 AM CST WED DEC 17 2014
.SYNOPSIS...
ISSUED AT 348 AM CST WED DEC 17 2014
REGION REMAINS ENTRENCHED IN COLD CYCLONIC FLOW WITH STRATUS AND
A FEW FLURRIES ON BACKSIDE OF EASTERN CONUS LONGWAVE TROUGH
AND EMBEDDED SHEARING CLOSED CIRCULATION OVER THE UPPER MIDWEST.
TEMPS RUNNING ON AVERAGE 20-25 DEGS COLDER FROM 24 HRS AGO WITH
READINGS IN THE UPPER TEENS TO MID 20S... WITH NW WIND 10-15+ MPH
MAKING IT FEEL EVEN COLDER AND MORE LIKE THE SINGLE DIGITS TO
LOWER TEENS. WATER VAPOR IMAGERY SHOWS ACTIVE SOUTHERN BRANCH OF
JET STREAM WITH SEVERAL EMBEDDED PERTURBATIONS MOVING THROUGH THE
SOUTHWESTERN CONUS. PRIMARY DISTURBANCE OF INTEREST WAS LOCATED
NEAR BAJA CA AND EXPECTED TO LIFT OUT ACROSS THE SOUTHERN PLAINS
AND MID-MISSISSIPPI VLY TONIGHT AND THURSDAY... AND MAY BRUSH THE
SOUTHERN CWA WITH SOME LIGHT SNOW OR FLURRIES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 348 AM CST WED DEC 17 2014
MAIN CHALLENGES ARE CLOUD TRENDS WITH IMPACT ON TEMPS... AND THE
POTENTIAL FOR LIGHT SNOW ACROSS THE SOUTHERN CWA LATE TONIGHT.
FOG ENHANCEMENT SATL IMAGERY SHOWS THE BACK EDGE OF THE STRATUS
MAINLY ALONG AND EAST OF I-35 PROGRESSING SLOWLY E/SE WITH
MORE EXPANSIVE AREA OVER SOUTHEAST MN MOVING NEARLY DUE SOUTH
AHEAD OF SHEARING CLOSED CIRCULATION. THE LATEST RAP SOUNDINGS
SUGGEST STRATUS MAY REMAIN TRAPPED UNDER INVERSION FOR MOST OF
THE DAY... WHILE NAM WOULD MAINTAIN STRATUS THROUGH MID AM BEFORE
BREAKING UP FROM WEST TO EAST. MODELS IN GENERAL HAVE BEEN TOO
OPTIMISTIC WITH CLEARING TRENDS... BUT WITH FLOW BECOMING MORE
ANTICYCLONIC TO NEARLY NEUTRAL AHEAD OF PLAINS SFC RIDGE BUILDING
IN AND AS MID LEVEL SUBSIDENT REGION SOUTH OF SHEARING CLOSED
CIRCULATION OVERSPREADS THE AREA TODAY BELIEVE PROSPECTS GOOD
FOR AT LEAST PARTIAL CLEARING LATER TODAY AND INTO THIS EVENING.
WHERE STRATUS BREAKS UP EXPECT SOME HIGH THIN CIRRUS ESPECIALLY
SOUTH HALF AHEAD OF SOUTHWEST SYSTEM. AS CLOUDS GO... SO GO THE
TEMPS AND HAVE STAYED NEAR GUIDANCE BLEND OR ON THE COLD SIDE WITH
HIGHS FROM MID 20S TO LOWER 30S. IF STRATUS REMAINS TRAPPED
UNDER THE INVERSION ALL DAY PER RAP SOUNDINGS THEN TEMPS STRUGGLE
WITH WIDESPREAD MID TO SOME UPPER 20S. GRADIENT TO WEAKEN TODAY
ESPECIALLY THIS AFTERNOON SO WINDS BECOMING MUCH LESS OF A FACTOR
ON THE CHILLS.
TONIGHT... SHORTWAVE TROUGH PROGGED TO LIFT FROM SOUTHERN PLAINS
TOWARD THE MID-MISSISSIPPI VLY BY 12Z ALTHOUGH IT LOOKS TO
DAMPEN/WEAKEN MARKEDLY AS IT MOVES INTO UPPER RIDGING OVER THE
MIDWEST. MODEL TIME-HEIGHT PLOTS AND SOUNDINGS DEPICT INCREASING
MID-HIGH LEVEL MOISTURE OVERNIGHT MAINLY SOUTHWESTERN 1/3-1/2 OF
THE CWA. GEM...GFS AND ECMWF ALL GENERATE SOME VERY LIGHT QPF
ACROSS THE FAR SOUTHWEST CWA LATE TONIGHT... BUT CLOSER INSPECTION
OF SOUNDINGS SHOW LOW LEVELS REMAIN DRY AND SATURATION INCOMPLETE
FOR MORE THAN JUST FLURRIES. GIVEN THAT THIS WILL BE VERY LATE
(AFT 09Z) DEVELOPING AND LOW CONFIDENCE WITH SATURATION COMPOUNDED
BY WEAKENING SYSTEM HAVE OPTED TO KEEP FCST DRY FAR SOUTH AND OMIT
ANY MENTION OF FLURRIES FOR NOW. LOWS QUITE CHALLENGING DUE TO
CLOUD COVER TRENDS. HAVE KEPT LOWS WITH GUIDANCE BLEND OR ON THE
COOL SIDE AND IN THE TEENS TO AROUND 20 DEGS. 850 MB TEMPS OF
AROUND -5C COUPLED WITH NEAR CALM WINDS AND ANY CLEARING WOULD
SUPPORT COLDEST MINS OF MID TEENS 13-16F.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 348 AM CST WED DEC 17 2014
FORECAST FOCUS ON A CHANCE OF LIGHT SNOW IN OUR FAR SOUTH THURSDAY
THEN ANOTHER CHANCE OF PRECIPITATION EARLY NEXT WEEK.
THURSDAY...OPERATIONAL MODELS DISAGREE ON MOISTURE/SATURATION AS A
SHORT WAVE TRACKS FROM THE SOUTHERN ROCKIES INTO THE MID MS VALLEY
IN THE MORNING. THE ECMWF/GEM ARE THE MOST AGGRESSIVE WITH LIGHT QPF
IN OUR SOUTHERN CWA WHILE THE AMERICAN MODELS ARE ESSENTIALLY DRY.
FORECAST SOUNDINGS INDICATE DRY LOW LEVELS SO IT WILL REMAIN TO BE
SEEN HOW MUCH THE LOW LEVELS CAN SATURATE. FOR COLLABORATION REASONS
I HAVE BUMPED UP POPS TO 40 IN EXTREME NORTHEAST MO...WITH SLIGHTS
AS FAR NORTH AS A FAIRFIELD TO MACOMB LINE. FARTHER NORTH IN THE CWA
THE DRY AIR IS FIRMLY ENTRENCHED WITH HIGH PRESSURE CENTERED IN THE
UPPER MIDWEST. ANY ACCUMULATIONS WILL BE MINOR AND WE ARE TALKING
ONLY A COUPLE OF TENTHS OF AN INCH IN EXTREME NORTHEAST MO. THE WAVE
MOVES QUICKLY INTO THE OHIO VALLEY DURING THE AFTERNOON WITH
LINGERING FLURRIES POSSIBLE. I HAVE LOWERED POPS IN THE AFTERNOON IN
OUR FAR SOUTH TO LESS THAN 20. MAXIMUM TEMPERATURES WILL RANGE FROM
THE UPPER 20S NORTH TO THE LOWER 30S SOUTH.
FRIDAY THROUGH SUNDAY...STORM SYSTEM IN THE SOUTHERN STREAM IS STILL
INDICATED BY MODELS TO REMAIN WELL SOUTH OF THE CWA. AN UPPER LEVEL
TROUGH MOVES ACROSS THE MIDWEST BUT AIRMASS IS TOO DRY TO MENTION
ANY MEASURABLE PRECIPITATION...AS THE DEEPER MOISTURE IS TIED TO THE
SOUTHERN STREAM STORM. HIGH TEMPERATURES DURING THIS PERIOD WILL BE
MAINLY IN THE 30S WITH LOWS IN THE 20S.
MONDAY AND TUESDAY...NEXT IN YOUR HIT PARADE IS A DEEPENING TROUGH
THAT DIGS INTO THE MIDWEST. OPERATIONAL MODELS ARE FAIRLY SIMILAR
WITH THIS FEATURE. HIGH END CHANCE POPS ARE IN THE GRIDS FOR THIS
SITUATION BUT PLENTY OF ROOM TO GO HIGHER OVER THE NEXT SEVERAL DAYS.
WITH THE SURFACE LOW REMAINING TO OUR NORTH THIS SETS UP THE
POTENTIAL FOR RAIN OR A RAIN/SNOW MIX BUT THEN TURNING TO ALL SNOW
BY THE TIME WE GET TO TUESDAY AFTERNOON AND TUESDAY NIGHT.
REMAINDER OF CHRISTMAS WEEK...MODELS HAVING DIFFICULTY WITH PHASING
ISSUES AS THE 00Z/17 ECMWF CRANKS UP A WHOPPER OF A WINTER STORM
(BOMBOGENESIS) TRACKING FROM THE LOWER MS VALLEY TO THE GREAT LAKES
CHRISTMAS EVE...WITH ARCTIC AIR PLUNGING QUICKLY INTO THE COUNTRY
BEHIND THE SYSTEM. THE GFS IS FARTHER EAST AND DEEPENS THE STORM IN
NEW ENGLAND INSTEAD. BEING A WEEK AWAY THERE LIKELY WILL BE MORE
CHANGES BUT CHRISTMAS TRAVELERS WILL WANT TO STAY TUNED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1131 PM CST TUE DEC 16 2014
LINGERING LOW CLOUDS OVER IL AND THE EASTERN HALF OF IA WILL BE
SLOW TO MOVE OUT LATE TONIGHT AND WEDNESDAY MORNING...RESULTING IN
CONTINUED MVFR CONDITIONS DUE TO CIGS. SCATTERED FLURRIES WILL
REMAIN POSSIBLE ESPECIALLY AT CID AND MLI LATE TONIGHT. THE
UPDATED FORECASTS CONTINUE A GRADUAL CLEARING TREND...LIFTING
CLOUD BASES TO WELL ABOVE MVFR THRESHOLDS...IN A LOW CONFIDENCE
12Z TO 18Z TIMEFRAME. THERE IS HIGHER CONFIDENCE THAT ALL SITES
WILL BE VFR FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING. NW
WINDS WILL DIMINISH THROUGHOUT AND BECOMING LIGHT FROM THE NORTH
WEDNESDAY NIGHT AS HIGH PRESSURE BUILDS INTO THE UPPER MS VALLEY.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...05
SHORT TERM...05
LONG TERM...HAASE
AVIATION...SHEETS
AREA FORECAST DISCUSSION
NWS DES MOINES IA
344 AM CST WED DEC 17 2014
.SHORT TERM /TODAY/...
ISSUED AT 344 AM CST WED DEC 17 2014
NO SIGNIFICANT WEATHER OF CONCERN TODAY...BUT TEMPS MAY BE A TAD
PROBLEMATIC. RIGHT ENTRANCE REGION OF IA/IL JET SEGMENT AND WEAK
FORCING DRIVEN BY WRN KS SHORT WAVE AHEAD OF SWRN CONUS TROUGH
CONTINUE TO SPREAD TOKEN MID CLOUDS AND PRECIP ALOFT INTO SWRN
IA. FORCING REMAINS OF SIMILAR MAGNITUDE THROUGHOUT THE DAY...IS
MAINLY 3KM AND ABOVE...AND CONTINUES TO ADVANCE INTO SURFACE RIDGE
SO NO PRECIP IS ANTICIPATED THROUGH VALID PERIOD.
MODELS ARE HAVING SOME DIFFICULTY HANDLING CURRENT TEMP REGIME.
TEMPS HAVE COOLED BELOW SOME MODELS WHERE SKIES HAVE CLEARED. HIGH
RES MODELS ARE DOING BETTER THAN TRADITIONAL OPERATIONAL RUNS AS
HRRR...RAP AND GEM REGIONAL MODELS BETTER RESEMBLE REALITY.
QUESTION IS WHETHER TO EXTRAPOLATE THEIR SOLUTIONS INTO THE FUTURE
AS THEY VARY QUITE A BIT. RAP AND GEM REGIONAL KEEP THINGS QUITE
COOL WITH MINIMAL REBOUND WHILE HRRR IS BACK UP TOWARD MODEL
CONSENSUS BY AFTERNOON. EVEN THOUGH WINDS WILL DIMINISH SOMEWHAT
IN THE SURFACE RIDGE...STILL EXPECT SOME MIXING WITHOUT SNOW COVER
SO HAVE ONLY GONE JUST A TOUCH BELOW MODEL CONSENSUS WHICH IS NOT
DISSIMILAR TO MOS SUGGESTIONS.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 344 AM CST WED DEC 17 2014
A WEAK 500 MB TROUGH WILL PROGRESS ACROSS KANSAS AND MISSOURI ON
WEDNESDAY NIGHT AND THURSDAY...SPREADING LIGHT PRECIPITATION THAT
MAY MAKE IT INTO MAINLY SOUTHERN IOWA. HOWEVER...THERE WILL BE A
SURFACE HIGH PRESSURE RIDGE BUILD ACROSS THE STATE DURING THAT
TIME RESULTING IN LOW LEVEL DRY AIR ISSUES AS DEPICTED BY MOST
FORECAST SOUNDINGS. IT APPEARS PROBABLE THAT THERE WILL AT LEAST
BE SOME FLURRIES OR VERY LIGHT SNOW ACROSS OUR SOUTHERN
COUNTIES...BUT FURTHER NORTH PRECIPITATION IS MUCH LESS LIKELY AND
EVEN IN THE SOUTH ANY ACCUMULATIONS SHOULD BE LIGHT. HAVE
MAINTAINED CHANCE POPS LATE WEDNESDAY NIGHT AND THURSDAY MORNING
WITH SNOWFALL AMOUNTS AROUND AN INCH OR LESS AND GENERALLY LIMITED
TO I-80 SOUTHWARD. THERE IS A POSSIBILITY OF FREEZING DRIZZLE AT
TIMES IF THE CLOUD LAYER IS SUFFICIENTLY SHALLOW/WARM...HOWEVER AT
THIS TIME THAT IS AN UNLIKELY SCENARIO AND IT HAS NOT BEEN
INCLUDED IN THE FORECAST DUE TO THE LOW PROBABILITY OF
OCCURRENCE.
FROM THURSDAY NIGHT THROUGH SATURDAY THE AFOREMENTIONED SURFACE
HIGH PRESSURE RIDGE WILL REMAIN ANCHORED JUST TO OUR EAST...FROM
THE GREAT LAKES DOWN ACROSS ILLINOIS...RESULTING IN VERY LIGHT
SOUTHERLY FLOW AND LIKELY SEVERAL MORE DAYS OF LOW STRATUS CLOUDS
THAT WILL LIMIT TEMPERATURE FLUCTUATIONS. HAVE INCREASED CLOUD
COVER FORECAST AND COMPRESSED DIURNAL TEMPERATURE SPREADS
ACCORDINGLY. IT IS PROBABLE THAT THIS WILL MANIFEST AS MORE
DRY BUT CLOUDY AND DREARY WEATHER TO END THE WORK WEEK.
BY SATURDAY A LONGWAVE 500 MB TROUGH WILL BE CROSSING THE ROCKIES
AND SHAPING UP TO BE A BIG PLAYER IN OUR WEATHER FOR THE FIRST
HALF OF NEXT WEEK. THE TROUGH WILL REACH THE HIGH PLAINS AND THE
MIDWEST BY SUNDAY AND SUBSEQUENTLY DEEPEN AS IT IS REINFORCED BY A
SERIES OF SUCCESSIVE SHORTWAVE IMPULSES ENTERING THE TROUGH FROM
WESTERN CANADA. BY TUESDAY BOTH THE ECMWF AND GFS ARE NOW CARVING
OUT A MASSIVE 500 MB TROUGH ACROSS MOST OF THE CONUS...WITH A
CENTRAL CLOSED LOW SOMEWHERE OVER THE UPPER MIDWEST. FOR OUR
FORECAST AREA THIS SCENARIO WILL TRANSLATE INTO A PROLONGED PERIOD
OF PRECIPITATION CHANCES...BEGINNING SOMETIME AROUND SUNDAY OR
SUNDAY NIGHT AND PERSISTING AT INTERVALS AT LEAST THROUGH TUESDAY.
HOWEVER...PRECIPITATION TYPE WILL BE HEAVILY DEPENDENT ON THE
LOCATION OF THE UPPER AND SURFACE LOW PRESSURE CENTERS AND THEIR
ASSOCIATED THERMAL PROFILES. CURRENT LONG RANGE MODEL SOLUTIONS
SUPPORT A FAIRLY LONG PERIOD OF RAIN WITH SNOW MORE LIMITED TO
NORTHERN IOWA AND LATER IN THE EVENT...LIKELY RESULTING IN LOW
SNOWFALL AMOUNTS. HOWEVER...WITH THE SYSTEM STILL FOUR OR FIVE
DAYS AWAY AND NOT EVEN ENTERING THE RAOB NETWORK UNTIL AROUND
FRIDAY...THE SOLUTIONS ARE HARDLY STABLE AND A WIDE RANGE OF
EVENTUAL OUTCOMES IS POSSIBLE SO THE FORECAST WILL LIKELY BE
FLUCTUATING IN THE COMING DAYS. ALL INTERESTS WITH TRAVEL PLANS
AROUND CHRISTMAS SHOULD CONTINUE TO MONITOR THESE TRENDS AND HOPE
THAT TEMPERATURES STAY WARM ENOUGH FOR THE PRECIPITATION TO FALL
PREDOMINANTLY AS RAIN.
&&
.AVIATION...17/06Z
ISSUED AT 1135 PM CST TUE DEC 16 2014
STRATUS BEGINNING TO ERODE FROM THE WEST AND THIS SHOULD CONTINUE
TO DIMINISH ACROSS THE FORECAST AREA OVERNIGHT WITH SURFACE RIDGE
APPROACHING. WILL SEE MAINLY VFR CONDITIONS ON WEDNESDAY INTO
WEDNESDAY NIGHT ALTHOUGH SOME MVFR CEILINGS MAY IMPACT THE NORTH
ON WEDNESDAY NEAREST THE UPPER LOW THAT WILL PASS EAST THROUGH THE
UPPER MIDWEST AND GREAT LAKES. SURFACE WINDS WILL REMAIN FROM THE
NORTHWEST BUT NOT NEARLY AS STRONG AS MONDAY.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...COGIL
AREA FORECAST DISCUSSION
NWS JACKSON KY
127 AM EST WED DEC 17 2014
.UPDATE...
ISSUED AT 116 AM EST WED DEC 17 2014
WITHIN THE LAST COUPLE OF HOURS...DRIZZLE HAS PICKED UP SIGNIFICANTLY
ACROSS THE NORTHERN HALF OF THE CWA...TRANSITIONING TO MORE OF A
SCATTERED RAIN SHOWER EVENT WITH EMBEDDED AREAS OF DRIZZLE. THERE
DOES SEEM TO BE A BACK EDGE TO THIS HEAVIER PRECIP...WHICH IS
CURRENTLY MOVING EASTWARD INTO OUR CWA. AS SUCH...HEIGHTENED WORDING
FROM DRIZZLE TO SCATTERED RAIN SHOWERS...DIMINISHING FROM WEST TO
EAST OVER THE NEXT 6 HOURS AND TRANSITIONING BACK TO DRIZZLE WITH A
FEW ISOLATED AREAS OF HEAVIER RAINFALL POSSIBLE THROUGH 12Z. ALSO
FRESHENED UP THE NEAR-TERM FORECAST FOR TEMPS...DEW POINTS...AND
WINDS...BASED ON THE 5Z OBSERVATIONS.
UPDATE ISSUED AT 1105 PM EST TUE DEC 16 2014
DRIZZLE AND SOME EMBEDDED SHOWERS CONTINUE ACROSS EASTERN KENTUCKY.
THE HOURLY POPS HAVE BEEN INCREASED TO ISOLATED FOR THE NORTH AND
EAST INTO EARLY ON THU. HOURLY TEMPERATURES HAVE BEEN FRESHENED UP
BASED ON RECENT OBSERVATIONS. NO SIGNIFICANT CHANGES WERE NEEDED AT
THIS TIME.
UPDATE ISSUED AT 745 PM EST TUE DEC 16 2014
HOURLY GRIDS HAVE BEEN UPDATED BASED ON RADAR AND OBSERVATION TRENDS.
THIS LED TO LOWERING TEMPERATURES IN THE HIGHEST TERRAIN INITIALLY
ABOVE 2500 FEET. MODEL PLAN VIEW DATA ALSO SUGGESTED SLIGHTLY LOWER
MIN T IN THE HIGHER TERRAIN NEAR BLACK MTN. RAIN SHOWERS CONTINUE
ACROSS THE EASTERN PART OF THE CWA...WITH SOME DRIZZLE FURTHER TO THE
WEST. MODEL DATA SUGGESTS SUFFICIENT MOISTURE FOR DRIZZLE TO LINGER
THROUGH THE NIGHT AND INTO EARLY ON WED. THE HIGHEST TERRAIN SHOULD
COOL ENOUGH FOR CHANCES OF FREEZING DRIZZLE ABOVE 2000 FEET. THIS
THREAT WILL BEGIN FIRST...IN THE NEXT HOUR OR TWO ON TOP OF BLACK MTN
AND THEN GRADUALLY SPREAD TO PINE MOUNTAIN AND POSSIBLY THE LOG
MOUNTAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 315 PM EST TUE DEC 16 2014
19Z SFC ANALYSIS SHOWS A FAIRLY DEEP AREA OF LOW PRESSURE LIFTING
NORTHEAST THROUGH THE EASTERN GREAT LAKES. THE COLD FRONT ASSOCIATED
WITH THIS SYSTEM IS NOW THROUGH EASTERN KENTUCKY AND AS A RESULT
GUSTY WEST WINDS ARE BRINGING IN A COLDER AIR MASS. AS IT DOES SO...
IT IS ALSO GENERATING A SUBSTANTIAL AREA OF DRIZZLE AND LOWER CIGS.
TEMPERATURES VARY FROM THE LOW 40S WEST TO NEAR 50S EAST ACROSS THE
CWA WITH DEWPOINTS IN THE UPPER 30S TO LOWER 40S.
THE MODELS ARE IN DECENT ENOUGH AGREEMENT ALOFT THROUGH THE SHORT
TERM PORTION OF THE FORECAST AS THEY ALL DAMPEN OUT THE CURRENT
TROUGH OVER THE AREA WHILE ABSORBING IT INTO THE MAIN MID LEVEL LOW
OVER THE UPPER MIDWEST. THIS WILL KEEP FAST...WEST TO EAST...FLOW
ABOVE EASTERN KENTUCKY INTO THE DAY WEDNESDAY...THOUGH MODEL
DIFFERENCES START TO MAGNIFY BY DAWN. THE ECMWF IS SLOWER MOVING
THIS MIDWEST LOW EAST COMPARED TO THE GEM AND GFS WHICH WILL ALSO
SERVE TO KEEP OUR HEIGHTS SLIGHTLY SUPPRESSED INTO WEDNESDAY EVENING.
DESPITE THIS...THE PREFERRED ECMWF DOES NOT LAG IN BRINGING THE NEXT
BATCH OF ENERGY INTO THE REGION FROM A QUICK MOVING WAVE PASSING OUT
OF THE SOUTHERN PLAINS. THIS WILL SEEP INTO OUR SOUTHWEST PARTS BY
THURSDAY MORNING. FOR THE FORECAST...FOLLOWED A BLEND OF THE HIGHER
RESOLUTION HRRR AND NAM12 WITH SOME ADJUSTMENT TOWARD THE MAIN
FEATURES IN THE LATEST ECMWF.
A DREARY EVENING AND OVERNIGHT IS ANTICIPATED THROUGH EASTERN
KENTUCKY AS LOW CIGS AND DRIZZLE WILL DOMINATE UNDER A SUBSIDENCE
INVERSION...PARTICULARLY OVER THE NORTHERN HALF THE CWA. THERE IS A
CONCERN THAT THE HIGHER POINTS OF EASTERN KENTUCKY FALL TO
FREEZING...OR A COUPLE OF DEGREES BELOW...BY DAWN GIVEN THE CAA
OVERNIGHT. COMBINED WITH THE AREAS OF DRIZZLE STILL AROUND...THERE
WILL BE A THREAT OF FREEZING DRIZZLE GENERALLY ABOVE 2000 FEET. FOR
THIS...WILL ISSUE AN SPS FROM LATE TONIGHT INTO THURSDAY MORNING FOR
OUR SOUTHEASTERN-MOST COUNTIES WITH THAT HIGHER TERRAIN. THE LOW
CLOUDS WILL PROBABLY HOLD TOUGH INTO THE FIRST PART OF THE DAY
WEDNESDAY BUT THERE COULD BE SOME BREAKUP MAKING FOR A BRIEF PERIOD
OF SUNSHINE DURING THE AFTERNOON AHEAD OF THE NEXT BATCH OF HIGHER
CLOUDS DUE IN HERE LATER THAT EVENING. THESE NEXT CLOUDS WILL QUICKLY
INCREASE AND LOWER THROUGH THE NIGHT WITH EVEN SOME LIGHT RAIN OR
SNOW POSSIBLE BY DAWN THURSDAY...THOUGH TEMPERATURES WILL BE MILDER
THAN TONIGHT IN MOST PLACES.
USED THE BCCONSSHORT AS A STARTING POINT FOR THE T/TD/WIND GRIDS FOR
THE FIRST 20 HOURS BEFORE POPULATING WITH THE SUPERBLEND THEREAFTER.
THESE WERE THEN SUBJECTED TO MINOR ADJUSTMENTS FOR TERRAIN EFFECTS
MAINLY TONIGHT AND WEDNESDAY NIGHT. AS FOR POPS...ENDED UP JUST ABOVE
THE HIGHER MET MOS GUIDANCE TONIGHT GIVEN THE LOW QPF BUT MODERATE
POPS WITH EXTRA EMPHASIS ON DRIZZLE AS PTYPE. ALSO...FOR LATE
WEDNESDAY WENT A BIT HIGHER THEN GUIDANCE IN THE SOUTHWEST GIVEN THE
FAST FLOW REGIME.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 245 PM EST TUE DEC 16 2014
PROGRESSIVE PATTERN WILL CONTINUE THROUGH THE EXTENDED. THE PERIOD
WILL START AS A MID LEVEL TROUGH CROSSES INTO THE OHIO RIVER VALLEY
ON THURSDAY. MODELS HAVE TRENDED MORE AGGRESSIVE WITH THIS FEATURE
WITH THE 12Z SUITE OF MODELS WITH GFS EVEN SHOWING SOME MODEST LIFT
ABOVE 850MB. THE MAIN LIMITING FACTOR FOR PRECIPITATION ON THURSDAY
WILL BE THE LOW LEVEL DRY AIR. HOWEVER...GIVEN THE DEEP MOISTURE
STARTING AROUND 5KFT...THIS SHOULD BE ENOUGH TO AT LEAST WARRANT A
CHANCE OF MEASURABLE PRECIPITATION REACHING THE GROUND.
HOWEVER...THIS PRECIPITATION MAY DRY UP AS IT TRIES TO PUSH
NORTHWARD THROUGH THE DAY. THUS...PLAN TO GO WITH CHANCE POPS ACROSS
THE SOUTH...TRAILING OFF TO SLIGHT CHANCE IN THE NORTH. ALL OF THIS
PRECIPITATION AS EXPECTED WILL REMAIN LIGHT...BUT SOME SNOWFLAKES
COULD MIX IN AT TIMES THROUGH THE DAY. HIGH PRESSURE WILL PROVIDE
DRY WEATHER THURSDAY NIGHT THROUGH FRIDAY.
THE WEATHER TURNS MORE INTERESTING BY FRIDAY NIGHT THROUGH SATURDAY
AS A SOUTHERN STREAM SHORTWAVE PUSHES EAST ACROSS THE SOUTHERN TIER
OF THE US. THIS SYSTEM IS NOT EXPECTED TO GET MUCH HELP FROM THE
NORTHERN STREAM...AND THUS...NOT MUCH COLD AIR IS EXPECTED TO GET
WORKED INTO THIS SYSTEM. THIS FACT...COMBINED WITH A WEAKENING AREA
OF LOW PRESSURE TRACKING ACROSS THE GULF COAST STATES WILL LIKELY
YIELD VERY LITTLE SNOW POTENTIAL. HOWEVER...WE ARE ON THE NORTH SIDE
OF THIS SYSTEM...WHICH WOULD BE THE BEST SPOT FOR ANY SNOW.
PRECIPITATION IS EXPECTED TO SPREAD INTO THE AREA LATE FRIDAY NIGHT
AND CONTINUE THROUGH SATURDAY. BEST SNOW POTENTIAL MAY BE AT THE
ONSET FRIDAY NIGHT...BUT AGAIN...PRECIPITATION RATES MAY BE FAIRLY
LIMITED...KEEPING SNOW AMOUNTS FROM BEING ALL THAT HIGH. IN
FACT...WE COULD SEE A MIX OF RAIN/SNOW RIGHT THROUGH SATURDAY WITH
VERY LITTLE SNOW ACCUMULATION FOR MUCH OF THE AREA. THE ECMWF
REMAINS THE COLDER OF THE MODELS SUGGESTING BETTER SNOW
POTENTIAL...WHILE THE GFS HAS MAINTAINED ITS ALL RAIN FORECAST.
GOING WITH A COMPROMISE ON HIGHS ON SATURDAY WOULD BE TEMPERATURES
AROUND 40 BY THE AFTERNOON ACROSS MUCH OF THE AREA. ITS POSSIBLE
SOME COOLER READINGS IN THE 30S COULD KEEP MORE SNOW GOING A BIT
LONGER ACROSS THE NORTHERN PORTION OF THE AREA...BUT WITH WEAK
PRECIP RATES...COMBINED WITH ABOVE FREEZING TEMPERATURES...SHOULD
REALLY CUT INTO ANY SNOWFALL POTENTIAL EVEN WITH THE COLDER ECMWF
SOLUTION. PRECIPITATION WILL WIND DOWN BY SATURDAY NIGHT GOING OVER
TO A PERIOD OF LIKELY DRIZZLE.
DRY WEATHER WILL RETURN FOR SUNDAY AND PERSIST INTO THE EARLY PART
OF NEXT WEEK. TEMPERATURES ARE EXPECTED TO REMAIN FAIRLY SEASONABLE
THROUGH THE END OF THE FORECAST PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 127 AM EST WED DEC 17 2014
WHILE AREAS OF DRIZZLE ARE ONGOING ACROSS MUCH OF EASTERN KY...THE
NORTHEAST PORTION OF THE STATE /GENERALLY AREAS NORTH OF THE MOUNTAIN
PARKWAY/... HAVE ACTUALLY SEEN A INCREASE FROM DRIZZLE TO LIGHT RAIN
SHOWERS. EXPECT THIS RAIN TO HAVE LITTLE DIFFERENCE IN IMPACTS TO
THAT OF THE DRIZZLE...SO WILL JUST CONTINUE WITH DRIZZLE MENTION AT
THIS TIME IN TAFS...ESPECIALLY GIVEN THAT THE RAIN SHOWERS SHOULD
TAPER OFF AT KSYM...KJKL...AND KSJS OVER THE NEXT COUPLE HOURS.
MEANWHILE...CIGS SHOULD REMAIN BETWEEN IFR AND MVFR THROUGH THE
REMAINDER OF THE NIGHT...THEN MVFR THROUGH A MAJORITY OF THE DAY
TOMORROW...AT LEAST UNTIL DRY AIR IS FINALLY ABLE TO MIX DOWN TO THE
SURFACE...CUTTING OFF DRIZZLE POTENTIAL...AND SLOWLY BREAKING THE LOW
CLOUD DECK. LATEST GFS FORECAST SOUNDINGS ARE SHOWING THIS OCCURRING
SOMETIME BETWEEN 18 AND 21Z...WHILE THE NAM TRIES TO HOLD ON TO THE
MOISTURE A BIT LONGER. LEANED MORE TOWARDS THE GFS SOLUTION AT THIS
TIME.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...JMW
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1115 PM EST TUE DEC 16 2014
.UPDATE...
ISSUED AT 1105 PM EST TUE DEC 16 2014
DRIZZLE AND SOME EMBEDDED SHOWERS CONTINUE ACROSS EASTERN KENTUCKY.
THE HOURLY POPS HAVE BEEN INCREASED TO ISOLATED FOR THE NORTH AND
EAST INTO EARLY ON THU. HOURLY TEMPERATURES HAVE BEEN FRESHENED UP
BASED ON RECENT OBSERVATIONS. NO SIGNIFICANT CHANGES WERE NEEDED AT
THIS TIME.
UPDATE ISSUED AT 745 PM EST TUE DEC 16 2014
HOURLY GRIDS HAVE BEEN UPDATED BASED ON RADAR AND OBSERVATION TRENDS.
THIS LED TO LOWERING TEMPERATURES IN THE HIGHEST TERRAIN INITIALLY
ABOVE 2500 FEET. MODEL PLAN VIEW DATA ALSO SUGGESTED SLIGHTLY LOWER
MIN T IN THE HIGHER TERRAIN NEAR BLACK MTN. RAIN SHOWERS CONTINUE
ACROSS THE EASTERN PART OF THE CWA...WITH SOME DRIZZLE FURTHER TO THE
WEST. MODEL DATA SUGGESTS SUFFICIENT MOISTURE FOR DRIZZLE TO LINGER
THROUGH THE NIGHT AND INTO EARLY ON WED. THE HIGHEST TERRAIN SHOULD
COOL ENOUGH FOR CHANCES OF FREEZING DRIZZLE ABOVE 2000 FEET. THIS
THREAT WILL BEGIN FIRST...IN THE NEXT HOUR OR TWO ON TOP OF BLACK MTN
AND THEN GRADUALLY SPREAD TO PINE MOUNTAIN AND POSSIBLY THE LOG
MOUNTAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 315 PM EST TUE DEC 16 2014
19Z SFC ANALYSIS SHOWS A FAIRLY DEEP AREA OF LOW PRESSURE LIFTING
NORTHEAST THROUGH THE EASTERN GREAT LAKES. THE COLD FRONT ASSOCIATED
WITH THIS SYSTEM IS NOW THROUGH EASTERN KENTUCKY AND AS A RESULT
GUSTY WEST WINDS ARE BRINGING IN A COLDER AIR MASS. AS IT DOES SO...
IT IS ALSO GENERATING A SUBSTANTIAL AREA OF DRIZZLE AND LOWER CIGS.
TEMPERATURES VARY FROM THE LOW 40S WEST TO NEAR 50S EAST ACROSS THE
CWA WITH DEWPOINTS IN THE UPPER 30S TO LOWER 40S.
THE MODELS ARE IN DECENT ENOUGH AGREEMENT ALOFT THROUGH THE SHORT
TERM PORTION OF THE FORECAST AS THEY ALL DAMPEN OUT THE CURRENT
TROUGH OVER THE AREA WHILE ABSORBING IT INTO THE MAIN MID LEVEL LOW
OVER THE UPPER MIDWEST. THIS WILL KEEP FAST...WEST TO EAST...FLOW
ABOVE EASTERN KENTUCKY INTO THE DAY WEDNESDAY...THOUGH MODEL
DIFFERENCES START TO MAGNIFY BY DAWN. THE ECMWF IS SLOWER MOVING
THIS MIDWEST LOW EAST COMPARED TO THE GEM AND GFS WHICH WILL ALSO
SERVE TO KEEP OUR HEIGHTS SLIGHTLY SUPPRESSED INTO WEDNESDAY EVENING.
DESPITE THIS...THE PREFERRED ECMWF DOES NOT LAG IN BRINGING THE NEXT
BATCH OF ENERGY INTO THE REGION FROM A QUICK MOVING WAVE PASSING OUT
OF THE SOUTHERN PLAINS. THIS WILL SEEP INTO OUR SOUTHWEST PARTS BY
THURSDAY MORNING. FOR THE FORECAST...FOLLOWED A BLEND OF THE HIGHER
RESOLUTION HRRR AND NAM12 WITH SOME ADJUSTMENT TOWARD THE MAIN
FEATURES IN THE LATEST ECMWF.
A DREARY EVENING AND OVERNIGHT IS ANTICIPATED THROUGH EASTERN
KENTUCKY AS LOW CIGS AND DRIZZLE WILL DOMINATE UNDER A SUBSIDENCE
INVERSION...PARTICULARLY OVER THE NORTHERN HALF THE CWA. THERE IS A
CONCERN THAT THE HIGHER POINTS OF EASTERN KENTUCKY FALL TO
FREEZING...OR A COUPLE OF DEGREES BELOW...BY DAWN GIVEN THE CAA
OVERNIGHT. COMBINED WITH THE AREAS OF DRIZZLE STILL AROUND...THERE
WILL BE A THREAT OF FREEZING DRIZZLE GENERALLY ABOVE 2000 FEET. FOR
THIS...WILL ISSUE AN SPS FROM LATE TONIGHT INTO THURSDAY MORNING FOR
OUR SOUTHEASTERN-MOST COUNTIES WITH THAT HIGHER TERRAIN. THE LOW
CLOUDS WILL PROBABLY HOLD TOUGH INTO THE FIRST PART OF THE DAY
WEDNESDAY BUT THERE COULD BE SOME BREAKUP MAKING FOR A BRIEF PERIOD
OF SUNSHINE DURING THE AFTERNOON AHEAD OF THE NEXT BATCH OF HIGHER
CLOUDS DUE IN HERE LATER THAT EVENING. THESE NEXT CLOUDS WILL QUICKLY
INCREASE AND LOWER THROUGH THE NIGHT WITH EVEN SOME LIGHT RAIN OR
SNOW POSSIBLE BY DAWN THURSDAY...THOUGH TEMPERATURES WILL BE MILDER
THAN TONIGHT IN MOST PLACES.
USED THE BCCONSSHORT AS A STARTING POINT FOR THE T/TD/WIND GRIDS FOR
THE FIRST 20 HOURS BEFORE POPULATING WITH THE SUPERBLEND THEREAFTER.
THESE WERE THEN SUBJECTED TO MINOR ADJUSTMENTS FOR TERRAIN EFFECTS
MAINLY TONIGHT AND WEDNESDAY NIGHT. AS FOR POPS...ENDED UP JUST ABOVE
THE HIGHER MET MOS GUIDANCE TONIGHT GIVEN THE LOW QPF BUT MODERATE
POPS WITH EXTRA EMPHASIS ON DRIZZLE AS PTYPE. ALSO...FOR LATE
WEDNESDAY WENT A BIT HIGHER THEN GUIDANCE IN THE SOUTHWEST GIVEN THE
FAST FLOW REGIME.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 245 PM EST TUE DEC 16 2014
PROGRESSIVE PATTERN WILL CONTINUE THROUGH THE EXTENDED. THE PERIOD
WILL START AS A MID LEVEL TROUGH CROSSES INTO THE OHIO RIVER VALLEY
ON THURSDAY. MODELS HAVE TRENDED MORE AGGRESSIVE WITH THIS FEATURE
WITH THE 12Z SUITE OF MODELS WITH GFS EVEN SHOWING SOME MODEST LIFT
ABOVE 850MB. THE MAIN LIMITING FACTOR FOR PRECIPITATION ON THURSDAY
WILL BE THE LOW LEVEL DRY AIR. HOWEVER...GIVEN THE DEEP MOISTURE
STARTING AROUND 5KFT...THIS SHOULD BE ENOUGH TO AT LEAST WARRANT A
CHANCE OF MEASURABLE PRECIPITATION REACHING THE GROUND.
HOWEVER...THIS PRECIPITATION MAY DRY UP AS IT TRIES TO PUSH
NORTHWARD THROUGH THE DAY. THUS...PLAN TO GO WITH CHANCE POPS ACROSS
THE SOUTH...TRAILING OFF TO SLIGHT CHANCE IN THE NORTH. ALL OF THIS
PRECIPITATION AS EXPECTED WILL REMAIN LIGHT...BUT SOME SNOWFLAKES
COULD MIX IN AT TIMES THROUGH THE DAY. HIGH PRESSURE WILL PROVIDE
DRY WEATHER THURSDAY NIGHT THROUGH FRIDAY.
THE WEATHER TURNS MORE INTERESTING BY FRIDAY NIGHT THROUGH SATURDAY
AS A SOUTHERN STREAM SHORTWAVE PUSHES EAST ACROSS THE SOUTHERN TIER
OF THE US. THIS SYSTEM IS NOT EXPECTED TO GET MUCH HELP FROM THE
NORTHERN STREAM...AND THUS...NOT MUCH COLD AIR IS EXPECTED TO GET
WORKED INTO THIS SYSTEM. THIS FACT...COMBINED WITH A WEAKENING AREA
OF LOW PRESSURE TRACKING ACROSS THE GULF COAST STATES WILL LIKELY
YIELD VERY LITTLE SNOW POTENTIAL. HOWEVER...WE ARE ON THE NORTH SIDE
OF THIS SYSTEM...WHICH WOULD BE THE BEST SPOT FOR ANY SNOW.
PRECIPITATION IS EXPECTED TO SPREAD INTO THE AREA LATE FRIDAY NIGHT
AND CONTINUE THROUGH SATURDAY. BEST SNOW POTENTIAL MAY BE AT THE
ONSET FRIDAY NIGHT...BUT AGAIN...PRECIPITATION RATES MAY BE FAIRLY
LIMITED...KEEPING SNOW AMOUNTS FROM BEING ALL THAT HIGH. IN
FACT...WE COULD SEE A MIX OF RAIN/SNOW RIGHT THROUGH SATURDAY WITH
VERY LITTLE SNOW ACCUMULATION FOR MUCH OF THE AREA. THE ECMWF
REMAINS THE COLDER OF THE MODELS SUGGESTING BETTER SNOW
POTENTIAL...WHILE THE GFS HAS MAINTAINED ITS ALL RAIN FORECAST.
GOING WITH A COMPROMISE ON HIGHS ON SATURDAY WOULD BE TEMPERATURES
AROUND 40 BY THE AFTERNOON ACROSS MUCH OF THE AREA. ITS POSSIBLE
SOME COOLER READINGS IN THE 30S COULD KEEP MORE SNOW GOING A BIT
LONGER ACROSS THE NORTHERN PORTION OF THE AREA...BUT WITH WEAK
PRECIP RATES...COMBINED WITH ABOVE FREEZING TEMPERATURES...SHOULD
REALLY CUT INTO ANY SNOWFALL POTENTIAL EVEN WITH THE COLDER ECMWF
SOLUTION. PRECIPITATION WILL WIND DOWN BY SATURDAY NIGHT GOING OVER
TO A PERIOD OF LIKELY DRIZZLE.
DRY WEATHER WILL RETURN FOR SUNDAY AND PERSIST INTO THE EARLY PART
OF NEXT WEEK. TEMPERATURES ARE EXPECTED TO REMAIN FAIRLY SEASONABLE
THROUGH THE END OF THE FORECAST PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 735 PM EST TUE DEC 16 2014
RAIN SHOWERS WILL GRADUALLY TAPER TO DRIZZLE DURING THE FIRST 6 HOURS
OF THE PERIOD NEAR...WHILE AREAS OF DRIZZLE ARE ANTICIPATED FURTHER
TO THE WEST. IN FACT...FORECAST SOUNDINGS AND TIME HEIGHTS CONTINUE
TO INDICATE A STRONG SUBSIDENCE INVERSION BEHIND THE FRONT...WITH LOW
LEVEL MOISTURE TRAPPED INTO AT LEAST THE 12Z TO 18Z PERIOD. THIS
WILL LEAD TO LOWERING CIGS LIKELY DOWN INTO THE IFR RANGE AT ALL TAF
STIES AT TIMES...WITH THE DRIZZLE POTENTIAL LINGERING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...JP
AREA FORECAST DISCUSSION
NWS DULUTH MN
317 AM CST WED DEC 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM CST WED DEC 17 2014
PRIMARY CONCERN FOR THE SHORT TERM PERIOD WAS LAKE EFFECT SNOWFALL
EVENT THIS MORNING AND INTO TODAY ACROSS THE SOUTH SHORE OF LAKE
SUPERIOR. OTHERWISE SEASONABLE CONDITIONS TODAY AND TOMORROW AS AN
AREA OF HIGH PRESSURE SETTLES IN ACROSS THE NORTHLAND.
EARLY THIS MORNING...OVERNIGHT RADAR RETURNS AND SURFACE
OBSERVATIONS INDICATED WIDESPREAD LIGHT SNOWFALL CONTINUED ACROSS
NORTHERN MINNESOTA. AS NEAR-SURFACE WINDS BACKED TO THE WEST LAKE
EFFECT SNOWFALL ACROSS THE SOUTH SHORE HAD TAPERED OFF...BUT AM
EXPECTING SNOW SHOWERS TO REDEVELOP TOWARDS SUNRISE THIS MORNING.
TEMPERATURES WERE HOLDING STEADY IN THE LOW TEENS ACROSS NORTHERN
MINNESOTA AND IN THE UPPER TEENS TO NEAR 20 IN NORTHWEST WISCONSIN.
WINDS WERE LIGHT OUT OF THE NORTHWEST AT 5 TO 10 KTS.
TODAY...THE WIDESPREAD LIGHT SNOW EARLY THIS MORNING WILL GRADUALLY
TAPER OFF AS WIDESPREAD SUBSIDENCE SETS IN DUE TO HIGH PRESSURE
MOVING INTO THE REGION. SKIES WILL BEGIN TO CLEAR PARTIALLY ALONG
THE INTERNATIONAL BORDER...BUT MOST LOCATIONS WILL REMAIN OVERCAST
DURING DAYLIGHT HOURS. A FEW FLURRIES WILL BE POSSIBLE IN THE LATE
AFTERNOON...BUT ACCUMULATING SNOWFALL WILL END BY MID-MORNING IN
MOST LOCATIONS. THE EXCEPTION WILL BE ALONG THE SOUTH SHORE OF LAKE
SUPERIOR WHERE LAKE EFFECT SNOW SHOWERS WILL REDEVELOP THIS
AFTERNOON AS THE LOW LEVEL WINDS BETTER ALIGN OUT OF THE NORTH. HAVE
DECREASED SNOWFALL AMOUNTS FROM PREVIOUS FORECASTS BASED ON THE
GUIDANCE AND EARLY MORNING OBSERVATIONS WHICH INDICATED LAKE EFFECT
SNOW SHOWERS HAVE TEMPORARILY DISSIPATED DUE TO BACKING OF
NEAR-SURFACE WINDS. RAP SOUNDINGS FOR THE SOUTH SHORE INDICATE THE
BEST LIFT TO BE BELOW THE DENDRITIC GROWTH ZONE...SO WHILE THERE
WILL BE FORCING AND MOISTURE...THE ALIGNMENT OF THE BEST LIFT MAY
RESULT IN LIMITED CRYSTAL GROWTH/AGGREGATION EXCEPT FOR ALONG THE
HIGHER TERRAIN WHERE MORE INTENSE SNOWFALL RATES COULD OCCUR.
DESPITE THESE RESERVATIONS FOR THE LAKE EFFECT SNOWFALL HAVE DECIDED
TO LEAVE THE CURRENT ADVISORY AND WARNING IN PLACE UNTIL WE BEGIN TO
RECEIVE SNOWFALL REPORTS THIS MORNING TO CONFIRM RADAR AND AUTOMATED
SURFACE OBSERVATIONS...BUT AM LEANING TOWARDS AN EARLY CANCELLATION
FOR THE WARNING AS ADDITIONAL AMOUNTS TODAY WILL PROBABLY ONLY BE IN
THE 1 TO 3 INCH RANGE.
HIGHS TODAY IN THE UPPER TEENS TO NEAR 20. WINDS WILL GRADUALLY VEER
TO THE NORTH/NORTHEAST AND WEAKEN TO 5 KTS OR LESS BY THE LATE
AFTERNOON.
TONIGHT...SOME CLEARING ALONG THE ARROWHEAD REGION OVERNIGHT WITH
NEAR CALM WINDS. A FEW LINGERING LIGHT SNOW SHOWERS/FLURRIES ALONG
THE SOUTH SHORE OF LAKE SUPERIOR. LOWS NEAR ZERO ALONG THE
INTERNATIONAL BORDER AND OTHER LOCATIONS WHERE SKIES MIGHT
CLEAR...ELSEWHERE IN THE LOW TEENS.
THURSDAY...INCREASING CLOUDS AS A MID-LEVEL DISTURBANCE MOVES EAST
ACROSS THE NORTHERN PLAINS AND INTO THE UPPER MIDWEST. THE 00Z HIRES
ARW DEPICTS AN AREA OF CONVERGENCE AND SNOW SHOWER DEVELOPING OVER
LAKE SUPERIOR BETWEEN TWO HARBORS AND HERBSTER...GRADUALLY DRIFTING
WEST TO BRING A FEW FLAKES TO THE NORTH SHORE BETWEEN THE TWIN PORTS
AND TWO HARBORS. DECIDED TO THROW IN A MENTION OF FLURRIES IN THIS
REGION AS WINDS APPEAR TO BE FAVORABLE FOR SUCH A DEVELOPMENT. VERY
LOW CONFIDENCE IN PREDICATION OF A MESOSCALE FEATURE LIKE THIS SO
FAR IN ADVANCE...BUT INTERESTING TO SEE THE HIGHER RESOLUTION ARW
MODEL PICK UP ON IT. HIGHS IN THE LOW TO MID 20S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 317 AM CST WED DEC 17 2014
FAIRLY QUIET WEATHER PATTERN FOR THE LATTER HALF OF THE WEEK WITH AN
EXITING RIDGE OF HIGH PRESSURE TO THE EAST AND A MILD AND DRY UPPER
TROUGH DROPPING IN FROM THE NW TO PRODUCE LOW CHANCES FOR VERY LIGHT
SNOW SHOWERS LATE FRIDAY INTO SATURDAY. THE SYNOPTIC FLOW WILL
REMAIN CYCLONIC...BUT RELATIVELY DRY THROUGH THE REST OF THE WEEKEND
PRIOR TO A RE-ENFORCING WAVE EJECTING OUT OF THE NRN ROCKIES WITH AN
ASSOCIATED SFC LOW FORMING OVER THE CENTRAL PLAINS SUN NIGHT AND
TRACKING TO THE EAST INTO THE SRN GREAT LAKES BY MON NIGHT/ TUE
MORNING. THIS SYSTEM WILL PRODUCE WIDESPREAD SNOW SHOWERS ACROSS THE
NORTHLAND LATE SUNDAY INTO EARLY NEXT WEEK...AND ALSO USHER IN A
MUCH COOLER AIR MASS GOING INTO THE MIDDLE OF THE WEEK. SNOW AMOUNTS
APPEAR TO BE RELATIVELY LIGHT AT THIS TIME.
TEMPERATURES EARLY IN THE EXTENDED PERIOD WILL BE ON THE COOL SIDE
WITH HIGHS IN THE 20S AND LOWS IN THE TEENS AND SINGLE DIGITS ABOVE
ZERO ON FRIDAY. A SLIGHT WARM UP WILL BE FELT SAT THROUGH MONDAY
WITH HIGHS IN THE 30S AND LOWS IN THE 20S. THE NEXT DROP IN
TEMPERATURES WILL BEGIN TUESDAY WITH HIGHS BACK DOWN INTO THE 20S
AND OVERNIGHT LOWS IN THE TEENS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1131 PM CST TUE DEC 16 2014
A MIX OF VFR/MVFR CIGS WITH AREAS OF LIGHT SNOW REDUCING VSBYS
INTO THE MVFR RANGE. THESE CONDITIONS WILL PERSIST THROUGH MUCH OF
THE FORECAST. AN IMPROVEMENT TO VFR WITH AN END TO THE SNOW AT INL
BY 10Z...HIB BY 18Z...DLH/BRD/HYR BY 00Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 21 14 24 16 / 30 10 10 0
INL 17 0 20 11 / 10 0 0 0
BRD 17 12 22 14 / 10 0 0 0
HYR 21 13 25 12 / 20 10 0 0
ASX 22 15 25 12 / 60 20 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR WIZ003-004.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR WIZ002.
LS...SMALL CRAFT ADVISORY UNTIL 10 AM CST THIS MORNING FOR LSZ121-
145>148.
&&
$$
SHORT TERM...JJM
LONG TERM...BJT
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1230 AM EST WED DEC 17 2014
.SYNOPSIS...
SHOWERS WILL MOVE OFFSHORE TONIGHT AS A COLD FRONT CROSSES THE
COAST. SEASONABLY COOL AND FAIR WEATHER WILL FOLLOW WEDNESDAY
THROUGH FRIDAY. AN APPROACHING STORM SYSTEM COULD BRING WET
WEATHER DURING THE UPCOMING WEEKEND. A DRYING TREND IS EXPECTED
EARLY NEXT WEEK WITH SEASONABLE TEMPERATURES...AS HIGH PRESSURE
FROM THE UPPER MID-WEST DROPS SOUTHEAST INTO THE CAROLINAS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 920 PM TUESDAY...THIS HAS BEEN THE LITTLE LINE OF SHOWERS THAT
COULD! EVEN THE HRRR HAS NOT SHOWN THE INCREDIBLY SOLID LINE OF
SHALLOW CONVECTION WE HAVE MOVING EAST ACROSS THE AREA. RAINFALL
AMOUNTS HAVE BEEN LIGHT...GENERALLY UNDER A TENTH OF AN INCH. THE
LUMBERTON ASOS REPORTED 0.11 AND THE LUMBERTON MESONET STATION HAD
0.14, THE TWO HIGHEST GAUGE TOTALS AVAILABLE TO US. RADAR ESTIMATES
ARE UPWARDS OF HALF AN INCH ACROSS NORTHERN ROBESON COUNTY NEAR THE
CUMBERLAND COUNTY LINE. CONVECTIVE ACTIVITY SHOULD CONTINUE TO
ADVECT EASTWARD AND OFF THE COAST BY MIDNIGHT. IN ITS WAKE CLEAR
SKIES ARE STILL EXPECTED. PREVIOUS DISCUSSION FROM 645 PM FOLLOWS...
THE FIRST WAVE OF PREFRONTAL SHOWERS AND SPRINKLES HAVE DIMINISHED
AND/OR MOVED EAST OF THE AREA. HOWEVER RADAR COMPOSITES SHOW A
NARROW BAND OF SHOWERS DEVELOPING ALONG THE FRONT ITSELF...CURRENTLY
ACROSS FAYETTEVILLE, LAURINBURG AND BENNETTSVILLE. ENVIRONMENTAL
LAPSE RATES BETWEEN 850 AND 600 MB ARE ACTUALLY QUITE STEEP (NEAR
6.5 DEG/KM OR MOIST-ADIABATIC) AND THIS ACTIVITY IS CONVECTIVE IN
NATURE WITH RADAR REFLECTIVITY IMPLYING THERE MAY BE A FEW MINUTES
OF QUITE HEAVY RAINFALL. SPC AUTOMATED MESOANALYSIS IS SHOWING
ELEVATED CAPE AROUND 100 J/KG AHEAD OF THE FRONT. MOISTURE IS A
LIMITING FACTOR WITH DEWPOINTS GENERALLY IN THE 50S WITH LIMITED
ATLANTIC INFLOW AND VIRTUALLY NO MOISTURE FROM THE GULF OF MEXICO.
LATEST HRRR MODEL RUNS INDICATE SCATTERED SHOWERS MAINLY ACROSS SE
NORTH CAROLINA CONTINUING FOR THE NEXT 2-3 HOURS...THEN SHIFTING
OFFSHORE. ACTIVITY WILL BE MORE SPARSE OR ENTIRELY ABSENT ACROSS NE
SOUTH CAROLINA AS THE BEST SYNOPTIC/UPPER LEVEL FORCING REMAINS
NORTH. NO CHANGES HAVE BEEN MADE TO FORECAST LOW TEMPS...AROUND 40
INLAND WITH MID 40S ON THE NC BEACHES.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
AS OF 345 PM TUESDAY...FAIR AND DRY WED/THU. SUBSIDENCE
OVERWHELMS THE COLUMN ENSURING A DEEP LAYER OF LOW RH AND WEST
WIND FLOW IN MID/UPPER ALTITUDES. PACIFIC ORIGIN SYSTEM AND
GENERAL WEST TO EAST FLOW RESULTING IN ONLY WEAK COOL AIR
ADVECTION AND MAXIMUMS WED LOOK TO REBOUND A FEW DEGREES ABOVE
NORMAL FOR MID DECEMBER. A SECONDARY BUT WEAK HIGH PRESSURE SURGE
MAY RESULT IN MAXIMUMS A DEGREE OR TWO COOLER THU...WITH
MORE/INCREASING CIRRUS THURSDAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 345 PM TUESDAY...LOW CONFIDENCE SPLIT FLOW FORECAST EARLY IN
THE PERIOD. SURFACE HIGH PRESSURE TO BE COVERING A LARGE PAR OF
THE NORTHEAST AND MID ATLANTIC ON FRIDAY. SOUTHERN BRANCH FEATURE
WILL MEANWHILE BE SKIRTING THE GULF COAST. A SURPRISINGLY SLOW
MOVER GIVEN THE FAIRLY ZONAL FLOW, THIS FEATURE WILL AFFECT THE
AREA MOST ON SATURDAY. MODEL AGREEMENT APPEARS TO BE A LITTLE
BETTER IN KEEPING THE SYSTEM TO OUR SOUTH IMPLYING THAT THIS WILL
BE A LIGHT TO PERHAPS MODERATE OVERRUNNING EVENT LOCALLY. RAIN MAY
LAST INTO EARLY SUNDAY BUT AS THE SYSTEM EXITS TO THE NORTHEAST
(WHETHER OR NOT IN A STRENGTHENING STATE) SOME DRY AIR WILL PUSH
INTO THE AREA FROM THE NW. THIS NEW AREA OF HIGH PRESSURE WILL
REMAIN TO OUR NORTHWEST FOR THE REMAINDER OF THE PERIOD WHILE THE
FLOW ALOFT REMAINS WEAKLY SPLIT. EARLY IN THE PERIOD DAYTIME HIGHS
WILL BE A BIT SUPPRESSED BY CLOUDS AND/OR RAIN WHILE NIGHTTIME
LOWS REMAIN SLIGHTLY ELEVATED ABOVE CLIMO FOR THE SAME REASON.
WITH THE ARRIVAL OF THE COOLER DRY AIR DAYTIME HIGHS MAY TAKE A
SMALL HIT WHILE NIGHTTIME LOWS LOSE THE BENEFIT OF CLOUDS AND
RETURN TO NORMAL OR CLOSE TO IT.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...THE COLD FRONT IS FINALLY OFFSHORE...AND IS MOVING
FURTHER AWAY FROM THE MAINLAND EARLY THIS AM. THE INFLUX OF LOWER
DEWPOINTS...AKA DRIER AIR...IS SLOW TO ADVANCE ACROSS THE FA. AS A
RESULT...ENUF SFC BASED MOISTURE WILL BE AVBL FOR MVFR/IFR BR
DEVELOPMENT...WITH ISOLATED LIFR FROM FG. ALL TERMINALS WILL
BECOME VFR BY DAYBREAK WED AS THOSE LOWER DEWPOINTS INFILTRATE THE
FA.
EXPECT CONTINUED VFR CONDITIONS FOR THE REMAINDER OF THE 06Z TAF
ISSUANCE PERIOD. POST COLD FRONTAL WINDS WILL BECOME WNW TO NNW
AT 4-8 KT. BY SUNSET WED...WINDS WILL LIKELY DECOUPLE AS A SFC
BASED INVERSION DEVELOPS.
EXTENDED OUTLOOK...VFR THU THROUGH FRIDAY. GOOD CHANCE OF RAIN ON
SATURDAY AND SUNDAY WITH POSSIBLE MVFR/IFR CONDITIONS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 920 PM TUESDAY...WINDS ARE AT THEIR STRONGEST ACROSS THE
COASTAL WATERS CURRENTLY, AROUND 20 KNOTS, AND SHOULD DIMINISH AS
THE FRONT CROSSES OFFSHORE. AT 9 PM THE FRONT EXTENDS FROM WESTERN
PENDER COUNTY ACROSS WHITEVILLE TO WESTERN HORRY COUNTY, MOVING EAST
AT 25 KNOTS. THE BIGGEST CHANGE WITH THIS UPDATE WAS TO INCREASE
SHOWER CHANCES ACROSS THE NC COASTAL WATERS BASED ON UPSTREAM RADAR
IMAGERY AND MESOANALYSIS CONTINUING TO SHOW SMALL BUT POSITIVE
INSTABILITY ALOFT. PREVIOUS DISCUSSION FROM 645 PM FOLLOWS...
WINDS ARE A SOLID 20 KNOTS ACROSS THE COASTAL WATERS AND MAY
ACTUALLY INCREASE TOWARD 25 KNOTS FOR A SHORT PERIOD BETWEEN 7-9 PM
AHEAD OF THE COLD FRONT...NOW MOVING INTO THE WESTERN PORTIONS OF
THE COASTAL PLAIN. THIS FRONT SHOULD PUSH OFF THE COAST LATE THIS
EVENING WITH WINDS VEERING AROUND TO THE NW AND DIMINISHING TO 15
KNOTS OR LESS. SEAS HAVE BUILT TO 6 FEET OUT AT FRYING PAN
SHOALS...WITH BUOYS CLOSER TO SHORE READING ANYWHERE FROM 2-5 FEET
DEPENDING ON HOW OPEN THEY ARE TO FETCH FROM SW WINDS.
THE BIGGEST CHANGE WITH THIS FORECAST UPDATE WAS TO INCREASE
FORECAST WAVES ALONG THE BRUNSWICK COUNTY BEACHES BY ~3 FEET TO 4-5
FEET GIVEN THE LONG ONSHORE FETCH. WHEN WAVE DATA WAS AVAILABLE FROM
THE OCEAN CREST PIER (STILL OUT OF SERVICE AT THIS TIME) IT TAUGHT
US A LOT ABOUT WAVE BEHAVIOR HERE GIVEN VARIOUS WIND DIRECTIONS.
ONCE WINDS VEER NW BEHIND THE FRONT SEAS SHOULD BEGIN TO DIMINISH.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 345 PM TUESDAY...BUMPY SEAS WILL LINGER INTO DAYBREAK
WEDNESDAY AS AN EXERCISE CAUTION STATEMENT RUNS THROUGH 12Z/7AM
WEDNESDAY. SW WAVES 2-4 FT EVERY 4 SECONDS WILL CO-MINGLE WITH
LIGHT NW CHOP AND ESE WAVE 1 FT OR LESS EVERY 10-11 SECONDS FOR A
GOOD PART OF WED BEFORE WIND-WAVES EASE IN THE AFTN. BY THU 2 FT
SEAS ON THE WATERS AND LIGHT N-NNE WIND. NO TSTMS OR RESTRICTIONS
TO VISIBILITY ON THE 0-20NM WATERS WED/THU.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 345 PM TUESDAY...FLOW REMAINS MOSTLY NORTHERLY ON FRIDAY
WITH HIGH PRESSURE ENTRENCHED ACROSS MOST OF THE NORTHEAST AND
MID-ATLANTIC. LOW PRESSURE DEVELOPING ALONG THE GULF STATES TO MOVE
VERY SLOWLY EASTWARD. THIS SYSTEM WILL AFFECT THE AREA ON
SATURDAY...REMAINING TO OUR SOUTH AS IT PASSES BY. THE ENCROACHING
WARM FRONT MAY VEER THE FLOW OVER PART OF THE REGION BUT ITS TOUGH
TO SAY EXACTLY HOW FAR NORTH THIS BOUNDARY TRAVERSES. REGARDLESS
WIND AND SEAS BOTH TO REMAIN BELOW ADVISORY OR SCEC REALM THROUGH
THE PERIOD. NORTHWESTERLY WINDS GET UNDERWAY SUNDAY AS THIS SYSTEM
EXITS...ONCE AGAIN WITH NO REAL STRENGTH TO THE GRADIENT AND THUS
NO CONCERN FOR ANY CAUTIONARY HEADLINES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...III
NEAR TERM...TRA
SHORT TERM...MJC
LONG TERM...MBB
AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
310 AM CST WED DEC 17 2014
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 309 AM CST WED DEC 17 2014
TEMPERATURES WILL BE THE MAIN ISSUE FOR THE SHORT TERM.
THE UPPER LOW OVER THE GREAT LAKES WILL PULL FURTHER AWAY FROM THE
PLAINS TODAY...WITH SOME SLIGHTLY HIGHER HEIGHTS MOVING IN BEHIND.
SFC HIGH PRESSURE WILL CONTINUE TO EXTEND FROM CANADA INTO THE
CWA. CLOUDS CONTINUE OVER OUR EASTERN COUNTIES AND WILL HAVE TO
WATCH IF THEY PUSH FURTHER WEST. THINK THAT MORE CLOUDS WILL MOVE
INTO THE VALLEY TOWARDS SUNRISE BUT THINK THAT THEY SHOULD BE
SHORT LIVED AS THE RAP HAS RH VALUES DECREASING A BIT AS WE HEAD
INTO THE DAY. KEPT EAST OF THE RED RIVER IN THE MOSTLY CLOUDY
RANGE. TEMPS THIS MORNING IN THE WEST HAVE DROPPED BELOW ZERO
UNDER CLEAR SKIES...BUT THINK THERE SHOULD BE ENOUGH SUN TO GET
BACK INTO THE TEENS FOR HIGHS.
TONIGHT...A WEAK SHORTWAVE WIL MOVE INTO THE WESTERN DAKOTAS...BUT
NOT MUCH MOISTURE WITH IT ACCORDING TO THE MODELS. THE SFC HIGH
WILL START TO MOVE EAST IN RESPONSE...WITH SOUTHERLY WINDS
RETURNING. AT THIS POINT THINK THE WESTERN COUNTIES WILL AGAIN SEE
CLEAR SKIES BUT SOME MIXING FROM WINDS WILL KEEP TEMPS ABOVE ZERO
WHILE THE EAST WILL HAVE CLOUDS AND BE NEAR 10 DEGREES. THE
SOUTHERLY WINDS WILL PICK UP ON THURSDAY AND THERE SHOULD BE SOME
INCREASING CLOUDS THROUGHOUT THE DAY AS MOISTURE RETURN PICKS UP.
THERE WILL ALSO BE SOME WARM AIR ADVECTION SO TEMPS SHOULD BE ABLE
TO RETURN TO THE 20S.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 309 AM CST WED DEC 17 2014
THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE WEAK UPPER TROUGH
CONTINUES TO MAKE ITS WAY ACROSS THE NORTHERN PLAINS. THE
SOUTHERLY WINDS AND WARM AIR ADVECTION WILL CONTINUE...WITH THE
MODELS SHOWING SOME ISENTROPIC LIFT MOVING IN LATE THURSDAY NIGHT
AND INTO FRIDAY. CONDENSATION PRESSURE DEFICITS ARE NOT OVERLY
HIGH AND LIFT IS PRETTY WEAK. MODELS ALL PUT OUT VERY MINIMAL QPF
BUT SOME LIGHT SNOW IS NOT OUT OF THE QUESTION. KEPT SOME LOW POPS
GOING FRIDAY...BUT ANY ACCUMULATIONS WILL BE MINIMAL. TEMPS WILL
CONTINUE TO MODERATE WITH LOWS IN THE TEENS AND HIGHS ON FRIDAY
IN THE 20S.
FOR SATURDAY THROUGH TUESDAY...WEATHER OVER THE AREA IS EXPECTED
TO REMAIN FAIRLY TRANQUIL AS MOST OF THE JET ENERGY STAYS TO THE
SOUTH. SOUTHWESTERLY FLOW AT THE SFC BEHIND THE SFC RIDGE AND
INCREASING THICKNESS VALUES INDICATE A SLOW WARMING TREND...WITH
TEMPS REMAINING ABOVE NORMAL. NEXT CHANCE FOR PCPN WILL BE ON
MONDAY AS A WEAK PACIFIC WAVE CROSSES THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1130 PM CST TUE DEC 16 2014
MODEL RH FIELDS...AS WELL AS THE HRRR/RAP GUIDANCE TO AN
EXTENT...BRING CLOUDS BACK WEST (SATELLITE IMAGERY CONFIRMS THIS
SCENARIO). THE MOST PROBABLE SOLUTION IS THAT KDVL REMAINS
CLEAR...VFR CLOUDS (@4000FT) MOVE INTO THE VALLEY SITES...WITH
MVFR CIGS INTO KBJI. ANTICIPATE A SLOW CLEARING TREND DURING THE
DAY WEDNESDAY. WINDS WILL BE LIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...TG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
302 AM CST WED DEC 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 302 AM CST WED DEC 17 2014
THE CHALLENGE TODAY IS SIMILAR TO TUESDAY WITH FORECASTING THE
MOVEMENT OF A DISTINCT/SHARP DELINEATION OF CLOUDS/NO
CLOUDS...ALIGNED FAIRLY CLOSE TO AND ALONG HIGHWAY 83 THIS
MORNING. A SOLID OVERCAST WITH ISOLATED FLURRIES DOMINATE ALONG
AND TO THE WEST OF THIS LINE...WITH MOSTLY CLEAR CONDITIONS
EXTENDING EAST OF THIS LINE. TEMPERATURES DEPENDENT ON THE
MOVEMENT OF THIS LINE TODAY/TONIGHT. IN ADDITION...THE APPROACH OF
SHORTWAVE TROUGH ALOFT AND A WARM FRONT INTO EASTERN MONTANA THIS
EVENING/WEDNESDAY NIGHT WILL RESULT IN ISENTROPIC LIFT AND A
SLIGHT CHANCE OF VERY LIGHT SNOW IN THE SOUTHWEST.
THE LATEST FOG/STRATUS IMAGERY LOOP REMAINS NEARLY UNCHANGED IN
THE LAST 6 HOURS WITH THE STRATUS LINE NUDGING A BIT FARTHER
EAST...NOW INTO MINOT AND LINTON AGAIN. THE HRRR/RAP13/NAM/GFS
925MB RH TREND SHOWS NEARLY A STATIONARY SITUATION WITH THE STRATUS
DECK DURING THE DAY...FOLLOWED BY A GRADUAL PUSH EAST WEDNESDAY
EVENING AND WEDNESDAY NIGHT. THE LATEST HRRR ALSO HAS PATCHY FOG
DEVELOPING ACROSS THE SOUTHWEST AS THE STRATUS DECK CONTINUES TO
LOWER THIS MORNING. THIS SEEMS REASONABLE AND HAVE ADDED THIS INTO THE
FORECAST THROUGH 18Z. AS MENTIONED ABOVE...ISENTROPIC LIFT PER NAM
285K PRESSURE SURFACE ACROSS THE SOUTHWEST LATER THIS AFTERNOON
INTO TONIGHT WILL BE ENOUGH FOR A SIGHT CHC MENTION OF LIGHT
SNOW...ALTHOUGH EXPECTING LIMITED AMOUNTS WITH LIQUID EQUIVALENCIES
OF BETWEEN ONE AND TWO HUNDREDTHS OF AN INCH. OTHERWISE CLOUDS
REMAIN IN-TACT THROUGH THE SHORT TERM PERIOD WEST WITH ISOLATED
FLURRIES...AND MOSTLY SUNNY EAST CENTRAL. HIGHS TODAY WILL RANGE
FROM LOWER TO MID TEENS FROM THE TURTLE MOUNTAINS SOUTH TO THE
JAMES RIVER VALLEY...TO THE LOWER 20S SOUTHWEST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 302 AM CST WED DEC 17 2014
A QUIET START TO THE EXTENDED FORECAST TRANSITIONING INTO A
POTENTIALLY MORE ACTIVE PATTERN EARLY TO MID NEXT WEEK HIGHLIGHTS
THE LONG TERM.
THE 00 UTC GUIDANCE SUITE IS IN AGREEMENT ON SPLIT FLOW ACROSS THE
CENTRAL CONUS THURSDAY INTO SATURDAY...FAVORING HIGHS SLIGHTLY
ABOVE NORMAL IN THE MID 20S TO MID 30S AND DRY CONDITIONS.
THEREAFTER...ENERGY COMING ON SHORE TO THE PACIFIC NORTHWEST THIS
WEEKEND IS FORECAST TO PROPAGATE INTO THE CENTRAL CONUS LATE
SUNDAY INTO TUESDAY. THIS WOULD LEAD TO AN AMPLIFICATION OF THE
UPPER LEVEL PATTERN WITH A DEEPENING CENTRAL CONUS TROUGH. THIS
WILL HAVE TO BE MONITORED FOR POTENTIAL WINTER WEATHER CHRISTMAS
TRAVEL IMPACTS NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 302 AM CST WED DEC 17 2014
WIDESPREAD/SOLID MVFR CIGS AT KISN/KBIS NEXT 24HR. IFR CIGS AND
AT KDIK THROUGH 01Z THURSDAY...AND THERE COULD BE PATCHY FOG AT
THE TERMINAL THROUGH 18Z. THIS MAY BE ADDED INTO THE 12Z TAFS.
KMOT HAS BEEN WOBBLING ON THE EDGE OF THE STRATUS LINE...AND IT
APPEARS NOW KMOT WILL REMAIN JUST WITHIN THE STRATUS DECK FOR MVFR
CIGS. KJMS WILL CONTINUE WITH VFR CIGS/MOSTLY CLEAR SKY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KS
LONG TERM...AYD
AVIATION...KS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
406 AM EST WED DEC 17 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD INTO THE REGION THROUGH TONIGHT BUT
ABUNDANT MOISTURE TRAPPED IN THE LOWER LEVELS OF THE ATMOSPHERE
WILL RESULT IN A CONTINUATION OF CLOUDY SKIES. A WEAK UPPER LEVEL
DISTURBANCE COULD LEAD TO A FEW FLURRIES THURSDAY AFTERNOON INTO
THURSDAY NIGHT. A BETTER CHANCE OF RAIN AND SNOW WILL MOVE INTO
THE REGION ON SATURDAY AS A LOW PRESSURE SYSTEM MOVES THROUGH THE
TENNESSEE VALLEY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SOME SLIGHTLY DEEPER MOISTURE IS RESULTING IN SOME LINGERING RAIN
AND SNOW SHOWERS ACROSS EASTERN PORTIONS OF OUR FA EARLY THIS
MORNING. MEANWHILE...PCPN HAS TRANSITIONED TO MORE OF A DRIZZLE OR
FLURRY ACROSS WESTERN PORTIONS OF OUR FA. THE LATEST RAP DOES
ALLOW FOR THE SURFACE TO 2 KM LAYER TO CONTINUE TO DRY OUT FROM
WEST TO EAST ACROSS THE AREA THROUGH MID MORNING. THIS SHOULD
ALLOW FOR THE DRIZZLE/FLURRY ACTIVITY TO GRADUALLY TAPER OFF FROM
THE WEST. IN THE LOW LEVEL CAA PATTERN...TEMPERATURES HAVE BEEN
STEADILY FALLING THIS MORNING WITH READINGS NOW AT OR A BIT BELOW
FREEZING ACROSS OUR NORTHWEST. AS A RESULT...THERE COULD BE SOME
AREAS OF FREEZING DRIZZLE THIS MORNING BEFORE THE PCPN TAPERS
OFF...ESPECIALLY ACROSS OUR NORTHERN AREAS. WITH THE WARM
TEMPERATURES OF THE PAST FEW DAYS...ROAD SURFACES ARE STILL
RUNNING SEVERAL DEGREES ABOVE FREEZING. THAT BEING SAID..ELEVATED
SURFACES AND UNTREATED BRIDGES/OVERPASSES COULD SEE A LIGHT ICE
ACCUMULATION AND WILL GO AHEAD AND COVER THE THREAT WITH AN SPS.
OTHERWISE...EXPECT CLOUDY SKIES TO CONTINUE THROUGH THE REST OF
THE AFTERNOON IN CONTINUED CYCLONIC LOW LEVEL FLOW. THE
COMBINATION OF CLOUDS AND CAA WILL RESULT IN FAIRLY STEADY TEMPS
TODAY IN THE LOW TO MID 30S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
BASED ON THE UPSTREAM CLOUD COVER AND CONTINUED CYCLONIC
FLOW...SEE NO REASON TO STRAY FROM THE MUCH MORE CLOUDY NAM
SOLUTION THAT KEEPS ABUNDANT LOW LEVEL MOISTURE IN PLACE TONIGHT
INTO THURSDAY. THE LOW LEVELS WILL BEGIN TO DRY OUT THURSDAY AFTERNOON
INTO THURSDAY NIGHT AS A WEAKENING MID LEVEL SHORTWAVE MOVES OUT
OF THE MID MISSISSIPPI VALLEY. FORCING IS PRETTY WEAK BY THE TIME
IT MAKES IT INTO OUR AREA AND WITH ONLY SOME LIMITED
MOISTURE...THINK WE MAY JUST SEE A FEW FLURRIES WITH THIS.
BOUNDARY LAYER TEMPERATURES APPEAR WARM ENOUGH ACROSS THE FAR
SOUTH THURSDAY AFTERNOON TO ALLOW FOR A FEW SPRINKLES TO MIX IN
WITH ANY FLURRY ACTIVITY. EXPECT HIGHS ON THURSDAY RANGING FROM THE
LOWER 30S NORTH TO MID 30S SOUTH...INCREASING INTO THE MID TO
UPPER 30S BY FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE AND DRY CONDITIONS WILL START OUT THE LONG TERM
PERIOD. THE NEXT SYSTEM WILL BEGIN TO APPROACH THE AREA LATE FRIDAY
NIGHT AND INTO THE DAY ON SATURDAY BEFORE TAPERING OFF SATURDAY
NIGHT. PRECIPITATION WILL GENERALLY BE IN THE FORM OF LIGHT SNOW
ACROSS THE NW HALF OF THE FA. PRECIPITATION IS EXPECTED TO START
OFF AS SNOW ACROSS THE SE HALF OF THE FA HOWEVER SOME RAIN IS
EXPECTED TO MIX IN DURING THE DAY BEFORE TRANSITIONING BACK TO LIGHT
SNOW.
HIGH PRESSURE WILL THEN WORK BACK INTO THE AREA FOR SUNDAY AND
MONDAY. THE NEXT SYSTEM WILL BEGIN TO WORK INTO THE AREA FOR
TUESDAY. MODELS WERE IN SOMEWHAT DECENT AGREEMENT WITH THIS FEATURE
HOWEVER THE 12Z ECMWF SOLUTION IS NOW SLOWER AND MORE ROBUST. DID
NOT WANT TO JUMP ON THIS NEW SOLUTION QUITE YET AND WENT WITH MORE
OF A MODEL BLEND FOR TUESDAY. A MIX OF RAIN AND SNOW ARE EXPECTED
HOWEVER AS COLDER AIR BEGINS TO MOVE INTO THE AREA PRECIPITATION
LOOKS TO CHANGE OVER TO ALL SNOW SHOWERS DURING THE TUESDAY NIGHT
INTO WEDNESDAY TIME PERIOD.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
MVFR LOW CLOUDS WILL PREVAIL THROUGH THE TAF PERIOD. THERE
CONTINUE TO BE SIGNIFICANT DISCREPANCIES IN GUIDANCE CONCERNING
CLOUDS POTENTIALLY CLEARING AFTER 15Z. BUT BASED ON WHAT HAS BEEN
OCCURRING UPSTREAM HAVE OPTED TO KEEP FORECAST PESSIMISTIC AND GO
WITH THE NAM AND RAP SOLUTIONS. THERE CONTINUE TO BE SOME
POTENTIAL FOR A BRIEF PERIOD OF IFR CEILINGS EARLY IN THE TAF
PERIOD WHICH HAVE BEEN HANDLED WITH TEMPO. ALSO THE CYCLONIC FLOW
ASSOCIATED WITH THE LOW OVER SE CANADA AND MOVING ENE CONTINUES TO
PRODUCE ENOUGH LOW LEVEL CONVERGENCE OVER THE FORECAST THAT VCSH
HAVE BEEN INTRODUCED TO ALL TAFS TILL AROUND SUNRISE. THE VCSH
WILL BE IN THE FORM OF SNOW SHOWERS AND MAY BRIEFLY LOWER VSBYS
INTO THE MVFR RANGE. NO GOOD WAY TO HANDLE THESE VSBYS IN THE FCST
DUE TO THE TEMPO IFR CLOUDS SO HAVE OPTED TO LEAVE THEM OUT.
SINCE THE INFLUENCE OF THE LOW WILL BE SLOW TO MOVE AWAY FROM THE
FORECAST AREA HAVE INTRODUCE WIND GUSTS BACK INTO THE TAFS ALTHOUGH
AT LOWER SPEEDS THAN YESTERDAY. WEST WINDS AT 15 WITH GUSTS TO 25
KT WILL DECREASE TO 10 TO 15 WITH GUST 20 KT DURING THE DAY AND W
AT 10 KT TONIGHT.
OUTLOOK...MVFR CEILINGS WEDNESDAY NIGHT AND THURSDAY. MVFR
CEILINGS AND VISIBILITIES POSSIBLE FRIDAY NIGHT INTO SATURDAY
NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JGL
NEAR TERM...JGL
SHORT TERM...JGL
LONG TERM...NOVAK
AVIATION...HAYDU
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
351 AM EST WED DEC 17 2014
.SYNOPSIS...
LOW LEVEL MOISTURE THROUGH THURSDAY NIGHT. HIGH PRESSURE FRIDAY.
LOW PRESSURE SYSTEM FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
LOOKS LIKE WE WILL BE REVERTING TO A SIMILAR SET UP FROM LATE LAST
WEEK WITH TRAPPED MOISTURE IN THE BOUNDARY LAYER UNDER ANOTHER
MASSIVE INVERSION WITH AROUND 60-90MB DEPTH. THIS IS THE BIGGEST
CHANGE TO THE FORECAST WITH GOING 100 SKY COVER ACROSS THE BOARD
THROUGH 12Z THURSDAY. FOLLOWING THE HRRR BRINGS THE CHANCES FOR
MEASURABLE PRECIPITATION TO AN END BY 00Z TONIGHT. CARRY
DRIZZLE/FREEZING DRIZZLE UNTIL 18Z TODAY AND WILL NEED TO MONITOR
THIS TO SEE IF THIS NEEDS TO GO LONGER IN THE FORECAST.
COLD AIR ADVECTION CONTINUING INTO THE OVERNIGHT BRINGS TEMPERATURES
BACK DOWN BELOW FREEZING AREA WIDE. WIND STAYING UP SHOULD KEEP ANY
POTENTIAL FOR FREEZING FOG AT BAY.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
BEFORE THE ADVERTISED STORM SYSTEM FOR THIS WEEKEND...OF WHICH
LITTLE HAS CHANGED IN THAT FORECAST...THE PATTERN ALOFT WILL BE
ZONAL WITH A SERIES OF WEAK UPPER DISTURBANCES MOVING ACROSS THE
AREA. THESE WILL KEEP CONSIDERABLE CLOUDINESS THURSDAY AND
FRIDAY...BUT NO PRECIP ADDED AS MOISTURE IS LIMITED AND THE
DISTURBANCES WILL BE WEAKENING AS THEY MOVE ACROSS. TEMPERATURES WILL
BE NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ACTIVE WEATHER IN THE LONG TERM PERIOD. PERIOD STARTS OUT WITH A
SPLIT UPPER FLOW PATTERN ACROSS THE U.S...WITH A LOW PRESSURE SYSTEM
IN THE SOUTHERN STREAM MOVING EAST ACROSS THE SOUTHEASTERN UNITED
STATES FRIDAY NIGHT INTO SATURDAY...WITH A SHORTWAVE TROUGH IN THE
NORTHERN STREAM PUSHING EAST ACROSS THE OHIO VALLEY...BRINGING A
REINFORCING SHOT OF COLD AIR INTO THE REGION. MODELS ARE STARTING TO
COME INTO BETTER AGREEMENT WITH THE TRACK OF THE LOW...BUT ECMWF IS
DEEPER...AND MORE PROGRESSIVE WITH NORTHERN STREAM SHORTWAVE...THUS
RESULTING IN A COLDER SOLUTION. DEPENDING ON WHICH SOLUN PANS
OUT...COULD SEE MORE OF A WINTRY MIX...AS WITH THE GFS SOLUN...OR A
MAINLY SNOW...WITH POSSIBLY BRIEF RAIN/SNOW MIX ACROSS
LOWLANDS...WITH THE ECMWF SOLUN. HAVE TRENDED THE FORECAST TOWARDS
HPC...WHICH TENDS TO FAVOR WARMER SOLUN. THUS...EXPECTING A WINTRY
MIX TO DEVELOP ACROSS THE AREA FRIDAY NIGHT/SATURDAY...BEFORE
TRANSITIONING TO MAINLY RAIN ACROSS THE LOWLANDS SATURDAY...THEN
BACK TO SNOW OR A MIX SATURDAY NIGHT. ITS POSSIBLE WINTER WEATHER
HEADLINES MAY BE NEEDED DURING THIS PERIOD.
HIGH PRESSURE WILL BUILD IN BEHIND THE SYSTEM FOR EARLY NEXT
WEEK...FOR A BRIEF BREAK IN THE PRECIPITATION...BEFORE ANOTHER
SYSTEM MOVES IN TOWARDS MID WEEK.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
LOOKING AT PERSISTENT MVFR CEILINGS/IFR IN BKW THROUGH THE BULK OF
THE PERIOD WITH BRIEF IFR INTO THE DAWN HOURS OVER THE LOWLANDS.
THIS IS THANKS TO ANOTHER DIRTY HIGH PRESSURE SYSTEM WHICH WILL
TRAP MOISTURE IN THE BOUNDARY LAYER LIKE WAS SEEN A FEW DAYS AGO
AND SHOULD YIELD OVERCAST SKIES THROUGH 06Z THURSDAY. USED THE MET
MOS GUIDANCE AND NAM FORECAST SOUNDINGS FOR THIS FORECAST...NOTING
THAT THE LAST 9 HOURS OF THE LAMP GUIDANCE BRINGS CEILINGS UP.
WILL NOT GO WITH THIS FOR THIS ISSUANCE.
NO VISIBILITY RESTRICTIONS EXPECTED WITH 8-12KT WINDS IN PLACE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: IFR MAY NOT DEVELOP AROUND DAWN. WILL NEED TO
WATCH GUIDANCE FOR CHANGES SUPPORTING VFR AFTER 00Z THURSDAY.
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 WED 12/17/14
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
CRW CONSISTENCY H H H H H H M M H H H M
HTS CONSISTENCY H H H H H H H M H H H M
BKW CONSISTENCY L H H M M H H H H H M M
EKN CONSISTENCY L M L L H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H M M H H H H
AFTER 06Z THURSDAY...
IFR POSSIBLE IN WINTRY MIX SATURDAY INTO SUNDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...26
SHORT TERM...JMV
LONG TERM...SL
AVIATION...26
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
112 AM EST WED DEC 17 2014
.SYNOPSIS...
AS LOW PRESSURE MOVES NORTHEAST THROUGH THE GREAT LAKES...A FEW
SHOWERS WILL CONTINUE TO BE POSSIBLE INTO THE OVERNIGHT HOURS.
COOLER CONDITIONS ARE EXPECTED THROUGH THE REST OF THE WEEK...WITH
GENERALLY DRY CONDITIONS. A CHANCE OF RAIN AND SNOW IS IN THE
FORECAST FOR SATURDAY...AS WEAK LOW PRESSURE APPROACHES THE REGION
FROM THE SOUTH.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MID LEVEL TROUGH AXIS IS STARTING TO PUSH EAST OF THE FORECAST
AREA. STILL SOME PATCHY RAIN WORKING ACROSS THE REGION. EXPECT
THIS TO BECOME MORE OF A DRIZZLE WHICH APPEARS TO BE HAPPENING
UPSTREAM. COULD EVEN BE SOME FLURRIES MIXED IN. AT THIS POINT
EXPECT PRECIPITATION TO END BEFORE TEMPERATURES GET BELOW FREEZING
IN THE WESTERN PART OF THE FORECAST AREA. ONLY MADE MINOR
ADJUSTMENTS TO TEMPERATURES BASED ON LATEST DATA. CLOUDS AND GUSTY
WEST WINDS WILL PERSIST THROUGH THE NIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
AS LOW PRESSURE MOVES NORTHEAST OF THE OHIO VALLEY...THE PRESSURE
GRADIENT WILL GRADUALLY RELAX ON WEDNESDAY...BUT CONTINUED COOL
WESTERLY FLOW WILL FORCE TEMPERATURES TO REMAIN BELOW AVERAGE.
ALTHOUGH DRY CONDITIONS ARE EXPECTED...THE BIGGEST FORECAST
CHALLENGE FOR WEDNESDAY WILL BE WITH SKY CONDITIONS. AS HAS BEEN
THE CASE SEVERAL TIMES ALREADY THIS COOL SEASON...THE NAM12
SOLUTION FOR LOW-LEVEL MOISTURE HAS REMAINED MUCH THICKER THAN
OTHER MODELS (GFS/GEM/ECMWF). KEEPING THE BOUNDARY LAYER WELL
MIXED BELOW 3000 FEET THROUGH THURSDAY MORNING...THE NAM12
MAINTAINS A THICK LAYER OF TRAPPED MOISTURE BELOW AN INVERSION.
DESPITE WHAT APPEARS TO BE A CONSENSUS FROM THE OTHER MODELS...THE
NAM12 HAS SHOWN SUCCESS IN THESE SCENARIOS THANKS TO ITS
RESOLUTION IN THE VERTICAL...AND IT CURRENTLY APPEARS TO BE
VERIFYING WELL OVER MISSOURI (WHERE OTHER MODELS ARE ALREADY
SUGGESTING CLEARER CONDITIONS THAN OBSERVED). SKY GRIDS HAVE THUS
BEEN INCREASED ON WEDNESDAY AND INTO WEDNESDAY NIGHT...ALLOWING
FOR SOME BREAKS IN THE EVENING.
AT 500MB ON WEDNESDAY NIGHT...A NARROW RIDGE WILL EXTEND FROM THE
SOUTHERN STATES NORTHWEST INTO THE MIDDLE MISSISSIPPI VALLEY. AS A
WEAK SHORTWAVE MOVES OUT OF THE FOUR CORNERS AREA AND RUNS INTO
THE RIDGE...IT WILL WEAKEN FURTHER...EVENTUALLY WASHING OUT OVER
THE OHIO VALLEY ON THURSDAY. BEFORE THE SYSTEM DISSIPATES...IT
APPEARS THAT SOME WEAK ISENTROPIC LIFT WILL ALLOW FOR AN INCREASE
IN CLOUDS ON THURSDAY...MOVING FROM SOUTHWEST TO NORTHEAST ACROSS
THE OHIO VALLEY. A SLIGHT CHANCE OF PRECIPITATION (MAINLY SNOW)
WAS ALSO INCLUDED...AS MOST LOCATIONS ARE LIKELY TO REMAIN
DRY...BUT SOME LIGHT PRECIPITATION MAY MAKE IT DOWN. MOST OF THE
CLOUDS AND FORCING SHOULD REMAIN ABOVE 5000 FEET...WITH AN
EXTREMELY WEAK SURFACE PRESSURE PATTERN PROVIDING NO SUPPORT.
COLD ADVECTION ON THURSDAY WILL BE MUCH WEAKER WITH THE LIGHTER
FLOW...BUT WITH A RELATIVELY SMALL DIURNAL TEMPERATURE COMPONENT
EXPECTED...TEMPERATURES ON THURSDAY ARE EXPECTED TO REMAIN FAIRLY
SIMILAR TO VALUES ON WEDNESDAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE AND DRY CONDITIONS WILL START OUT THE LONG TERM
PERIOD. THE NEXT SYSTEM WILL BEGIN TO APPROACH THE AREA LATE FRIDAY
NIGHT AND INTO THE DAY ON SATURDAY BEFORE TAPERING OFF SATURDAY
NIGHT. PRECIPITATION WILL GENERALLY BE IN THE FORM OF LIGHT SNOW
ACROSS THE NW HALF OF THE FA. PRECIPITATION IS EXPECTED TO START
OFF AS SNOW ACROSS THE SE HALF OF THE FA HOWEVER SOME RAIN IS
EXPECTED TO MIX IN DURING THE DAY BEFORE TRANSITIONING BACK TO LIGHT
SNOW.
HIGH PRESSURE WILL THEN WORK BACK INTO THE AREA FOR SUNDAY AND
MONDAY. THE NEXT SYSTEM WILL BEGIN TO WORK INTO THE AREA FOR
TUESDAY. MODELS WERE IN SOMEWHAT DECENT AGREEMENT WITH THIS FEATURE
HOWEVER THE 12Z ECMWF SOLUTION IS NOW SLOWER AND MORE ROBUST. DID
NOT WANT TO JUMP ON THIS NEW SOLUTION QUITE YET AND WENT WITH MORE
OF A MODEL BLEND FOR TUESDAY. A MIX OF RAIN AND SNOW ARE EXPECTED
HOWEVER AS COLDER AIR BEGINS TO MOVE INTO THE AREA PRECIPITATION
LOOKS TO CHANGE OVER TO ALL SNOW SHOWERS DURING THE TUESDAY NIGHT
INTO WEDNESDAY TIME PERIOD.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
MVFR LOW CLOUDS WILL PREVAIL THROUGH THE TAF PERIOD. THERE
CONTINUE TO BE SIGNIFICANT DISCREPANCIES IN GUIDANCE CONCERNING
CLOUDS POTENTIALLY CLEARING AFTER 15Z. BUT BASED ON WHAT HAS BEEN
OCCURRING UPSTREAM HAVE OPTED TO KEEP FORECAST PESSIMISTIC AND GO
WITH THE NAM AND RAP SOLUTIONS. THERE CONTINUE TO BE SOME
POTENTIAL FOR A BRIEF PERIOD OF IFR CEILINGS EARLY IN THE TAF
PERIOD WHICH HAVE BEEN HANDLED WITH TEMPO. ALSO THE CYCLONIC FLOW
ASSOCIATED WITH THE LOW OVER SE CANADA AND MOVING ENE CONTINUES TO
PRODUCE ENOUGH LOW LEVEL CONVERGENCE OVER THE FORECAST THAT VCSH
HAVE BEEN INTRODUCED TO ALL TAFS TILL AROUND SUNRISE. THE VCSH
WILL BE IN THE FORM OF SNOW SHOWERS AND MAY BRIEFLY LOWER VSBYS
INTO THE MVFR RANGE. NO GOOD WAY TO HANDLE THESE VSBYS IN THE FCST
DUE TO THE TEMPO IFR CLOUDS SO HAVE OPTED TO LEAVE THEM OUT.
SINCE THE INFLUENCE OF THE LOW WILL BE SLOW TO MOVE AWAY FROM THE
FORECAST AREA HAVE INTRODUCE WIND GUSTS BACK INTO THE TAFS ALTHOUGH
AT LOWER SPEEDS THAN YESTERDAY. WEST WINDS AT 15 WITH GUSTS TO 25
KT WILL DECREASE TO 10 TO 15 WITH GUST 20 KT DURING THE DAY AND W
AT 10 KT TONIGHT.
OUTLOOK...MVFR CEILINGS WEDNESDAY NIGHT AND THURSDAY. MVFR
CEILINGS AND VISIBILITIES POSSIBLE FRIDAY NIGHT INTO SATURDAY
NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...
SHORT TERM...HATZOS
LONG TERM...NOVAK
AVIATION...HAYDU
AREA FORECAST DISCUSSION
NWS NORMAN OK
1118 PM CST TUE DEC 16 2014
.AVIATION...
6Z TAFS... MVFR/VFR CONDITIONS FOR THE TAF PERIOD. HOWEVER...
MODEL GUIDANCE IS SUGGESTING IFR OR LOWER CEILINGS COULD BE
POSSIBLE LATE WED AFTN INTO EVENING. RAIN AND DRIZZLE WILL BE
POSSIBLE DURING THE DAY ON WED INTO WED EVENING. ISOLATED THUNDER
MAY ALSO OCCUR NEAR KOKC/KOUN/KLAW/KSPS SITES BUT CHANCES TOO LOW
FOR MENTION IN TAF ATTM. LIGHT FROZEN PRECIP IS ALSO NOT
COMPLETELY OUT OF THE QUESTION IN PARTS OF N OK. CHANCES SEEM LOW
SO WILL LEAVE OUT OF TAFS FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 859 PM CST TUE DEC 16 2014/
UPDATE...
INCREASED SKY COVER TONIGHT. ADDED SPRINKLE MENTION IN SOUTHWESTERN
OKLAHOMA AND WESTERN NORTH TEXAS 4 TO 6 AM WEDNESDAY. INCREASED
RAIN CHANCES NEAR THE RED RIVER EAST OF WICHITA FALLS WEDNESDAY
MORNING.
DISCUSSION...
MOISTURE CONTINUES TO INCREASE ACROSS THE AREA.
BASED ON LATEST SATELLITE AND MODEL DATA...INCREASED CLOUD COVER
TONIGHT. AS A RESULT...THINK TEMPERATURES WILL REMAIN RATHER
STEADY FOR THE REST OF TONIGHT.
ADDED SPRINKLE MENTION TO THE LOCATIONS MENTIONED IN THE
UPDATE LINE AS LATEST MODEL SOUNDINGS AND HRRR SUGGESTED THIS
DEVELOPMENT. ATMOSPHERIC SOUNDINGS AND GROUND TEMPERATURES ABOVE
FREEZING SUPPORT ALL LIQUID IN THESE LOCATIONS.
PARTS OF NORTHERN OKLAHOMA MAINLY NORTHEAST OF A ENID TO
GUTHRIE TO CHANDLER WILL BE NEAR OF JUST BELOW FREEZING...
29 TO 33 DEGREES...THROUGH WEDNESDAY MORNING. IF PRECIPITATION
WERE TO GET THIS FAR NORTH...A LIGHT WINTRY MIX OF MAINLY LIGHT
FREEZING RAIN AND/OR LIGHT SLEET COULD OCCUR. CONFIDENCE IN THIS
SCENARIO REMAINS LOW...ESPECIALLY MOST MODEL RUNS INCLUDING THE
00Z NAM DEPICTING THE HEAVIEST PRECIPITATION WELL SOUTH OF THESE
LOCATIONS. THUS...DID NOT MENTION AT THIS TIME. EVEN IF THIS
WINTRY MIX OCCURRED...TRAVEL IMPACTS WOULD BE VERY UNLIKELY DUE TO
WARMER ROAD SURFACE TEMPERATURES FROM RECENT WARM TEMPERATURES.
PRODUCTS HAVE BEEN UPDATED.
MBS
PREV DISCUSSION... /ISSUED 509 PM CST TUE DEC 16 2014/
AVIATION...
0Z TAFS... VFR/MVFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD.
RAIN CHANCES WILL BEGIN WED MORNING AND CONTINUE THROUGHOUT THE
DAY. ISOLATED THUNDERSTORMS WILL ALSO BE POSSIBLE WED AFTN WITH
MOST LIKELY LOCATIONS BEING KOKC/KOUN/KLAW/KSPS AND POINTS
SOUTHEAST. HOWEVER... THUNDERSTORMS EXPECTED TO BE ISOLATED
ENOUGH THAT WILL LEAVE A MENTION OUT OF TAFS FOR NOW.
PREV DISCUSSION... /ISSUED 238 PM CST TUE DEC 16 2014/
DISCUSSION...
MID-LEVEL MOISTURE FROM THE GULF WILL BEGIN POURING INTO THE
REGION TONIGHT. WITH SOME ISENTROPIC LIFT AND AN APPROACHING
SHORTWAVE...RAIN CHANCES WILL INCREASE THROUGH THE DAY TOMORROW.
SLIGHT RAIN CHANCES WILL CONTINUE INTO THURSDAY BEFORE ANOTHER
SYSTEM MAKES ITS WAY INTO THE AREA. KEPT A MENTION OF SNOW ACROSS
NORTHERN COUNTIES OVERNIGHT WEDNESDAY NIGHT...BUT CONFIDENCE IN
ANY FROZEN PRECIP IS LOW. RAIN AND DRIZZLE ARE MORE LIKELY.
THE MAIN TROUGH APPROACHES FRIDAY...BRINGING RAIN CHANCES TO
SOUTHERN PARTS OF THE CWA. MODELS CONTINUE TO SHOW A DRIER
THURSDAY AND FRIDAY...KEEPING THE MOISTURE FARTHER SOUTH. BROUGHT
POPS DOWN ACCORDINGLY.
BY THE WEEKEND...ANY PRECIP SHOULD BE OUT OF THE AREA. MODELS ARE
STARTING TO COME INTO BETTER ALIGNMENT...SHOWING ANOTHER TROUGH
COMING THROUGH MONDAY OF NEXT WEEK. THOUGH...AS OF YET...THIS
SYSTEM LOOKS TO BE DRY.
TEMPERATURES SHOULD BE SEASONABLY COOL THROUGHOUT THE FORECAST
PERIOD...WITH A GRADUAL WARM UP IN THE BEGINNING OF NEXT WEEK.
MAD
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 33 42 37 48 / 10 50 50 30
HOBART OK 34 42 36 48 / 10 50 30 20
WICHITA FALLS TX 38 44 40 55 / 10 60 30 10
GAGE OK 32 43 33 43 / 10 30 30 20
PONCA CITY OK 27 40 33 42 / 10 40 60 30
DURANT OK 33 44 39 52 / 0 70 70 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
17/25/25
AREA FORECAST DISCUSSION
NWS MEDFORD OR
930 PM PST TUE DEC 16 2014
.DISCUSSION...LOW PRESSURE OVER THE COASTAL WATERS WILL MOVE EAST
TO NORTHEAST TONIGHT WITH COLD FRONTAL PRECIPITATION FOCUSED FROM
THE MT SHASTA AREA SOUTHWARD. IT IS PRESENTLY 38 DEGREES AND
RAINING AT MT SHASTA CITY. PRECIPITATION ALONG THE I-5 CORRIDOR
IN FAR SOUTH CENTRAL SISKIYOU COUNTY WILL LIKELY CHANGE OVER TO
SNOW LATE TONIGHT...SHORTLY AFTER 2 AM...WITH THE SNOW LEVEL
IN THAT LOCAL AREA DROPPING TO AROUND 3000 FEET WITH MORE INTENSE
PRECIPITATION RATES LOWERING THE SNOW LEVEL. SNOWFALL AMOUNTS
TONIGHT ARE FORECAST TO BE AROUND 1 TO 3 INCHES NEAR MT SHASTA.
MEANTIME, THERE IS A CHANCE OF LIGHT SNOW OVER THE SOUTHERN
OREGON CASCADES AND EAST SIDE WITH NOT MUCH MORE THAN A DUSTING AT
ELEVATIONS ABOVE 4500 FEET.
A MORE WIDESPREAD SHOWERY PATTERN WILL DEVELOP FOR OUR AREA ON
WEDNESDAY...ESPECIALLY ON THE WEST SIDE. THE SNOW LEVEL WILL
REMAIN AROUND 4500 FEET WITH 1 TO 3 INCHES OF SNOW POSSIBLE FOR
THE SOUTHERN OREGON SISKIYOU AND CASCADE MOUNTAINS. SHOWERS AND
SNOW SHOWERS WILL DIMINISH WEDNESDAY NIGHT AS A RIDGE BUILDS TO
THE COAST.
A FOCUS FOR THE NIGHT SHIFT WILL BE ON THE DETAILS OF WHAT LOOK TO
BE STRONGER FRONTS TO AFFECT OUR AREA THURSDAY EVENING INTO
FRIDAY AFTERNOON AND THEN SATURDAY INTO EARLY SUNDAY. THIS SECOND
SYSTEM ON THE WEEKEND HAS HIGHER UNCERTAINTY/MODEL SOLUTION
VARIABILITY.
&&
.AVIATION...BASED ON THE 17/00Z TAF CYCLE...CONDITIONS REMAIN VFR
ACROSS THE MEDFORD CWA THIS EVENING WITH THE NOTABLE EXCEPTION OF
MVFR CEILINGS OVER SOUTHERN SISKIYOU COUNTY WITH MOUNTAIN
OBSCURATION AND LIGHT TO MODERATE RAIN AND SNOW. ALSO...STRONG
SOUTHERLY LOW LEVEL WINDS WILL DIMINISH AFTER MIDNIGHT.
OVERNIGHT...AREAS OF MVFR CIGS IN PRECIPITATION WILL INCREASE
ALONG THE SOUTH COAST RANGE AND OVER MOST OF SISKIYOU COUNTY WITH
HIGHER TERRAIN OBSCURED. ISOLATED IFR CIGS/VSBYS IN LOW CLOUDS AND
FOG ARE POSSIBLE OVER THE WESTERN VALLEYS LATE TONIGHT THROUGH
MID-MORNING WEDNESDAY...MAINLY IN THE UMPQUA BASIN.
&&
.MARINE...UPDATED 800 PM PST TUE DEC 16 2014...LOW PRESSURE
OVER THE WATERS WILL MOVE NORTHEAST TONIGHT WITH INCREASING SOUTH
WINDS AND BUILDING SEAS...ESPECIALLY SOUTH OF CAPE BLANCO AND
BEYOND 10NM OFFSHORE. WINDS WILL VEER TO WESTERLY EARLY WEDNESDAY
THEN RETURN TO SOUTHERLY BY WEDNESDAY NIGHT. A STRONGER FRONT WILL
PUSH THROUGH ON THURSDAY WITH STRONG SOUTH WINDS POSSIBLY REACHING
GALE STRENGTH. VERY HEAVY WEST SWELL AROUND 20 FEET WITH A
DOMINANT PERIOD OF 19 SECONDS WILL ARRIVE ON FRIDAY AND LIKELY
REMAIN VERY HIGH INTO SATURDAY.
&&
.PREV DISCUSSION... /ISSUED 216 PM PST TUE DEC 16 2014/
DISCUSSION...PRECIPITATION AHEAD OF A SURFACE LOW NEAR 42N/128W IS ALREADY
REACHING CAPETOWN CALIFORNIA AND IS MOVING NORTH TO NORTHEAST. THE
RAP IS DOING FAIRLY WELL IN INITIALIZING THE POSITION OF THE LOW AND
QPF FIELDS THIS AFTERNOON AND HAVE LEANED TOWARDS THIS SOLUTION FOR
THIS EVENING. WINDS HAVE INCREASED AHEAD OF THE LOW IN THE SHASTA
VALLEY AND WILL LAST THROUGH THE NIGHT, BUT DO NOT EXPECT THEM TO
REACH ADVISORY CRITERIA. THE RAP SHOWS THE PRECIP FIELD BREAKING UP
INTO TWO PARTS THIS EVENING. ONE PART WILL MOVE NORTH OVER THE
MARINE WATERS, THE OTHER WILL CONTINUE TO PUSH EAST INTO NORTHERN
CAL AND INTO THE MOUNT SHASTA REGION. THE PARAMETERS ON THE NAM WITH
RESPECT TO SNOW NEAR AND AT MOUNT SHASTA HAVE CHANGED LITTLE FROM
THE PREVIOUS RUN. IT STILL LOOKS FAVORABLE FOR HEAVIER PRECIPITATION
TO DEVELOP LATER THIS EVENING AND TONIGHT DUE TO UPSLOPE FLOW AND
850 MB TEMPERATURES NEAR 0C. IN ADDITION 700MB FLOW IS FROM THE
SOUTH BETWEEN 40-50 KTS. THE MAIN QUESTION WILL BE HOW MUCH. CURRENT
THINKING IS THAT WE`LL HAVE A RAIN WET SNOW MIX TO START THIS
EVENING WITH MODEL SOUNDINGS RIGHT AT THE CUSP BETWEEN RAIN AND
SNOW. PRECIPITATION WILL INCREASE TONIGHT FORCING THE SNOW LEVEL
DOWN LOW ENOUGH TO GET INTO MOUNT SHASTA. SNOW RATIONS WILL BE LOW,
BUT QPF VALUES SUGGEST WE COULD PICK UP AT LEAST 3 INCHES OR MORE
NEAR THE INTERSTATE, ESPECIALLY BETWEEN MOUNT SHASTA AND DUNSMUIR.
IT`S POSSIBLE HIGHWAY 89 COULD GET UP TO 6 INCHES OR MORE BY
DAYBREAK WEDNESDAY.
THE UPPER TROUGH MOVES THROUGH WEDNESDAY MORNING AND THE UPPER FLOW
WILL BECOME WESTERLY WHICH WILL LIMIT THE AMOUNT OF PRECIPITATION
IN THE MOUNT SHASTA REGION. ELSEWHERE VALLEY RAIN AND MOUNTAIN
SNOW SHOWERS WILL LINGER, BUT WERE NOT EXPECTING ANYTHING
NOTEWORTHY WITH MINIMAL IMPACT ON PASSES. SOME LEFTOVER SHOWERS
WILL LINGER INTO WEDNESDAY EVENING, THEN END OVERNIGHT AS
SHORTWAVE RIDGING BUILDS INTO THE AREA. WE`LL CATCH A DRY BREAK ON
THURSDAY WITH THE RIDGE AXIS OVER THE AREA, BUT THIS WILL BE SHORT
LIVED. THE MODELS SHOW A STRONGER FRONT APPROACHING THE AREA
THURSDAY AFTERNOON BRINGING INCREASING SOUTH WINDS OVER THE MARINE
WATERS WHICH COULD GET CLOSE TO GALES.
THIS FRONT WILL PUSH INLAND THURSDAY NIGHT WITH PRECIPITATION
SPREADING OVER MUCH OF THE FORECAST AREA. THE HEAVIEST AMOUNTS WILL
BE ALONG THE COAST RANGE, COASTAL MOUNTAINS AND CASCADES. RIGHT NOW
SNOW LEVELS WILL START OUT HIGH THURSDAY EVENING, BUT WILL DROP
TO AROUND 4500 FEET EARLY FRIDAY MORNING. SO IT`S A GOOD BET THE
MOUNTAIN PASSES WILL GET ACCUMULATING SNOW STARTING LATE THURSDAY
NIGHT THROUGH FRIDAY MORNING. RIGHT NOW, IT LOOKS LIKE CRATER LAKE
COULD PICK UP AT LEAST 6 INCHES OR MORE...A FEW INCHES OVER
SISKIYOU SUMMIT AND HIGHWAY 140. KEEP IN MIND THE DETAILS ON THIS
WILL CHANGE, SO STAY TUNED FOR THE LATEST UPDATES, ESPECIALLY FOR
ANYONE PLANING ON TRAVELING THE WEEKEND BEFORE CHRISTMAS.
-PETRUCELLI
LONG-TERM FORECAST...SATURDAY THROUGH TUESDAY. A BROAD LONG WAVE
RIDGE WILL BUILD INTO THE WEST COAST SATURDAY AND SUNDAY...WITH
GENERALLY NORTHWEST FLOW ALOFT. SHORT WAVES RIDING OVER THE TOP OF
THE RIDGE WILL WEAKEN IT FROM SUNDAY NIGHT ON...BUT IT WILL REMAIN
IN PLACE THROUGH TUESDAY. THE FLOW ALOFT WILL BECOME MORE ZONAL
THOUGH.
THIS PATTERN WILL FORCE THE MAIN STORM TRACK TO THE NORTH OF THE
MEDFORD CWA...BUT THE AREA WILL STILL CATCH THE SOUTHERN END OF
SEVERAL SYSTEMS WHICH WILL MOVE ONSHORE DURING THIS INTERVAL. THE
STRONGEST OF THESE SYSTEMS WILL MOVE ONSHORE SATURDAY AFTERNOON AND
EVENING...AND AGAIN MONDAY. THE BULK OF THE ASSOCIATED PRECIPITATION
WILL FALL ALONG THE COAST...COAST RANGE...AND UMPQUA BASIN. AMOUNTS
WILL BE SIGNIFICANT BUT NOT EXCESSIVE...NO FLOODING PROBLEMS ARE
ANTICIPATED. SNOW LEVELS WILL START OFF BETWEEN 4000 AND 5000 FEET
SATURDAY...BUT WILL RISE TO ABOVE 7000 FEET SATURDAY NIGHT INTO
SUNDAY AND REMAIN ABOVE ALL BUT THE HIGHEST TERRAIN UNTIL IT LOWERS
SLIGHTLY TUESDAY NIGHT. SO...THE HEAVIEST SNOWS WILL OCCUR WITH THE
SATURDAY SYSTEM.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...WINTER WEATHER ADVISORY UNTIL 10 AM PST WEDNESDAY FOR
CAZ082-083-282-284.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 1 AM PST
WEDNESDAY FOR PZZ356-370.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST
WEDNESDAY FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM PST WEDNESDAY FOR
PZZ376.
$$
DW/DW/SBN
AREA FORECAST DISCUSSION
NWS PORTLAND OR
912 PM PST TUE DEC 16 2014
.SYNOPSIS...A CLOSED LOW JUST OFFSHORE WEST OF THE OR/CA BORDER WILL
SLOWLY WEAKEN AND PUSH NORTHWARD OVERNIGHT...EVENTUALLY MOVING
ONSHORE ALONG THE N OR/S WA COAST TOMORROW AFTERNOON. THIS WILL
MAINTAIN LIGHT SHOWER ACTIVITY...MAINLY OVER THE HIGHER TERRAIN
OVERNIGHT AND TOMORROW MORNING. AN UPPER LEVEL SHORTWAVE WILL PUSH
ONSHORE LATER TOMORROW...LIKELY BRINGING A PERIOD OF STEADIER
RAINFALL THROUGH EARLY THU MORNING. EXPECT A FAIRLY QUIET PERIOD FOR
MUCH OF THE DAY THU...BUT THEN A MORE ORGANIZED FRONT WILL BRING
GUSTY WINDS AND LARGE SURF TO THE COAST...WITH RAIN SPREADING INLAND
THURSDAY NIGHT AND FRIDAY. RISING SNOW LEVELS WILL LIMIT SNOW TO THE
HIGHEST PEAKS...BUT COLDER AIR BEHIND THE FRONT MAY RESULT IN SOME
SNOW SHOWERS FOR THE CASCADES PASSES FRIDAY EVENING AND SATURDAY.
WARMER AND MOISTER WEATHER IS EXPECTED THIS WEEKEND. THERE IS THE
POTENTIAL FOR AN ATMOSPHERIC RIVER TYPE SET UP AND ASSOCIATED HEAVY
RAIN TO DEVELOP OVER THE WEEKEND INTO EARLY NEXT WEEK.
&&
.EVENING UPDATE...A LOW PRES CIRCULATION IS APPARENT ON SATELLITE AND
RADAR IMAGERY THIS EVENING JUST OFFSHORE OF THE CA/OR BORDER. WATER
VAPOR SATELLITE SHOWS MOISTURE SPREADING NORTHWARD FROM THIS SYSTEM
INTO NW OREGON AND SW WASHINGTON. THERE ARE ALSO LIGHT ECHOES SHOWING
UP ON RADAR OVER THE SOUTHERN AND WESTERN PORTIONS OF OUR FCST
AREA...BUT LITTLE TO NO RAIN IS REACHING THE GROUND AT THIS TIME.
EXPECT AS THE NIGHT GOES ON AND THE OFFSHORE LOW SLOWLY MOVES
NORTHEAST...WE WILL SEE LIGHT PRECIPITATION START TO REACH THE
SURFACE...ESPECIALLY OVER THE HIGHER TERRAIN. A WEAK VORT MAX WILL
ALSO MOVE ONSHORE EARLY WED MORNING...WHICH MAY HELP AID THE SHOWERS.
THE MAIN CHANGE TO THE FCST THIS EVENING WAS TO INCREASE POPS AND QPF
FROM THE 18Z WED TO 12Z THU TIME FRAME. THE CLOSED LOW JUST OFFSHORE
TONIGHT WILL SLOWLY WEAKEN AND PUSH ONSHORE AROUND MIDDAY TOMORROW.
MEANWHILE...THE SHORTWAVE NOW APPARENT ON WATER VAPOR SATELLITE
NEARING 45N 140W IS MODELED TO STRETCH OUT AND PUSH ONSHORE LATER
TOMORROW AFTERNOON AND EVENING. THE LOWER LEVEL MOISTURE ASSOCIATED
WITH THE SURFACE LOW COMBINED WITH THE UPPER LEVEL FORCING FROM THE
SHORTWAVE SHOULD DRIVE A PERIOD OF STEADIER PRECIP LATER TOMORROW
AND TOMORROW NIGHT. THE 00Z NAM AND GFS RUNS PICKED UP ON THIS
PERIOD OF ENHANCED PRECIP. THE VORT MAX PUSHES EAST OF THE CASCADES
BY 12Z THU...AFTER WHICH SHOWER ACTIVITY SHOULD DROP OFF
SIGNIFICANTLY. PYLE
.PREV DISC ISSUED 231 PM PST TUE DEC 17...
.SHORT TERM...TONIGHT THROUGH FRIDAY...SHOWERS HAVE PRETTY MUCH ENDED
OVER THE PORTLAND FORECAST AREA EARLY THIS AFTERNOON...EXCEPT FOR
VERY INFREQUENT ISOLATED SHOWER OVER THE SW WASHINGTON CASCADES.
SATELLITE IMAGERY SHOWS A SURFACE LOW AROUND 150 MILES WEST OF THE
SOUTHERN OREGON COAST...NEAR 42N 127W. THE HIGHER RESOLUTION
MODELS...HRRR AND RAP INITIALIZE BEST WITH THE LOW AND FORECAST RAIN
MOVING NORTH INTO LANE COUNTY SLIGHTLY EARLIER THAN THE OTHER MODELS.
HAVE TRENDED TOWARDS THIS EARLIER ARRIVAL...BUT ONLY HAVE FAIR
CONFIDENCE THAT THE TIMING WILL PAN OUT. ANY RAIN LATE THIS AFTERNOON
SHOULD BE FAIRLY LIGHT AND REMAIN WEST OF THE SOUTH AND CENTRAL
WILLAMETTE VALLEY.
THE LOW WILL MOVE CLOSER TO THE SOUTHERN OREGON COAST LATE THIS
AFTERNOON AND EVENING THEN MOVE ONTO THE CENTRAL OREGON COAST AS AN
UPPER TROUGH LATE TONIGHT...WITH SHOWERS MAINLY OVER THE HIGHER
TERRAIN THROUGH WEDNESDAY MORNING. SOME CLEARING EARLY WED MORNING
MAY RESULT IN SHALLOW FOG AND LOW CLOUDS IN SOME OF THE INTERIOR
VALLEYS...MAINLY SOUTH OF SALEM.
EASTERLY WINDS HAVE HELD ON TODAY WITH A TROUTDALE TO DALLES PRESSURE
GRADIENT HOLDING AROUND 5 MB. THIS GRADIENT SHOULD TIGHTEN A LITTLE
THIS EVENING AS THE LOW MOVES CLOSER TO THE COAST AND MAINTAIN GUSTS
AROUND 30 MPH THROUGH THE WESTERN COLUMBIA RIVER GORGE.
SHOWERS WILL CONTINUE WEDNESDAY...MAINLY FOR THE HIGHER TERRAIN AS
THE PARENT UPPER LEVEL TROUGH MOVES OVER THE PACIFIC NW. SHOWERS
SHOULD END OVERNIGHT AS AN UPPER RIDGE BUILDS OVER THE AREA AND
EXPECT THAT CLEARING SKIES AND LIGHT WINDS WILL LEAD TO SHALLOW FOG
FOR THE INTERIOR VALLEYS EARLY THURSDAY MORNING. MOST OF THURSDAY
WILL BE DRY WITH AN INCREASE OF MID AN HIGH LEVEL CLOUDS IN THE
AFTERNOON.
MODELS ARE IN GOOD AGREEMENT THAT A WELL ORGANIZED FRONT WILL BRING
GUSTY WINDS TO THE COAST THURSDAY EVENING WITH RAIN SPREADING INLAND
THURSDAY NIGHT AND FRIDAY. PRECIPITABLE WATER IS EXPECTED TO BE NEAR
AN INCH AND AN APPROACHING JET STREAK SHOULD PROVIDE GOOD LIFT AND
EXPECT THE HIGHEST RAINFALL TOTALS OF 0.75 TO 1 INCH ACROSS THE
COAST AND COAST RANGE THURSDAY NIGHT THROUGH FRIDAY MORNING. OTHER
AREAS SHOULD SEE BETWEEN 0.4 AND 0.60 INCH OF RAIN. SNOW LEVELS
SHOULD REMAIN ABOVE 5000 FEET DURING THE PEAK RAIN PERIOD...BUT LOWER
TO NEAR OR BELOW THE CASCADE PASSES BEHIND THE FRONT FRIDAY
AFTERNOON.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...A BROAD RIDGE OF HIGH
PRESSURE OVER THE WESTERN U.S. FLATTENS AS A STRONG LOW PRESSURE
SYSTEM OVER THE GULF OF ALASKA MOVES INLAND TO OUR NORTH. AS THIS
TROUGH MOVES ON SHORE SATURDAY...THE ASSOCIATED COLD FRONT MOVES
ONSHORE AND STALLS EAST-TO-WEST ACROSS NORTHWEST OREGON AND
SOUTHWEST WASHINGTON. THIS PUTS OUR AREA IN THE PATH OF RAIN
STARTING SATURDAY THROUGH MONDAY. SOME UNCERTAINTY EXISTS IN WHERE
THIS BOUNDARY WILL SET UP...WHICH WILL DETERMINE HOW MUCH RAINFALL
WE WILL GET. ON TUESDAY...GEFS ENSEMBLE SPAGHETTI PLOTS GET MESSY
AND SIGNIFICANT DIFFERENCES START TO SHOW UP BETWEEN THE GFS AND
ECMWF...DECREASING CONFIDENCE ON HOW THE REST OF THE WEEK WILL SHAPE
UP. AS OF NOW...THE MOST COMMON SOLUTION IS THAT HIGH PRESSURE
RIDGING WILL START TO BUILD BACK OVER THE WESTERN U.S. WHICH
SUGGESTS DRIER WEATHER STARTING TUESDAY...THOUGH UNCERTAINTY IS VERY
HIGH. -MCCOY
&&
.AVIATION...MOIST SOUTHERLY FLOW ALOFT...WITH PLENTY OF MID AND
HIGH CLOUDS OVER REGION. DO HAVE AREAS OF MVFR CIGS ALONG THE
COAST AND WILL SEE THOSE PERSIST OVERNIGHT INTO WED AM. QUESTION
IS WHETHER OR NOT LOW CLOUDS REFORM S OF SALEM TONIGHT. HAVE
CLEARED OUT AT MOMENT...WITH STILL RATHER HIGH HUMIDITY. SO
SUSPECT WITH OCCASIONAL LIGHT RAIN THERE...WILL SEE AREAS OF IFR
STRATUS REFORM TONIGHT TO SOUTH OF KSLE.
KPDX AND APPROACHES...VFR WILL PERSIST TONIGHT AND WED...BUT CIGS
LOWER TO 5K FT LATER AFTER 09Z WITH OCCASIONAL LIGHT RAIN THROUGH
17Z. VFR WITH LOT OF MID AND HIGH CLOUDS ON WED.ROCKEY.
&&
.MARINE...NOT MUCH CHANGE. GRADIENTS WEAKENING THIS EVENING AS
LOW HEADS INTO N CALIF. STILL...WILL GET A GUSTS TO 25 KT ON THE
OUTER SOUTH WATERS THIS EVENING. SEAS HOLDING AT 8 TO 9 FT.
NEXT SYSTEM NOW DEVELOPING WAY OFFSHORE BETWEEN 160W-170W. THIS
SYSTEM WILL BRING SOUTHERLY GALES TO THE WATERS LATER THU THROUGH
EARLY FRI AM. STILL SOME UNCERTAINTY ON EXACT TIMING AND DETAILS
BUT WILL BE VERY ACTIVE PERIOD. SEAS LIKELY TO PUSH BACK INTO THE
UPPER TEENS TO NEAR 20 FT BY FRI AM.
MORE FRONTS ARRIVE THIS WEEKEND INTO EARLY NEXT WEEK...WITH
SOUTHERLY GALES LIKELY AND ENHANCED SEAS. ROCKEY.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...GALE WATCH FOR THU AND THU NIGHT ON ALL COASTAL WATERS.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR TONIGHT
AND AGAIN 11 AM TO 4 PM WED.
&&
$$
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 GREENVILLE-SPARTANBURG SC
400 AM EST WED DEC 17 2014
.SYNOPSIS...
HIGH PRESSURE WILL SPREAD BACK OVER THE REGION TODAY BEHIND A
DEPARTING COLD FRONT. A WEAK WEATHER SYSTEM ALOFT WILL SPREAD CLOUDS
AND PERHAPS SOME SPOTTY LIGHT SHOWERS IN THE MOUNTAINS ON THURSDAY.
ANOTHER LOW WILL DEVELOP TO OUR SOUTHWEST ON FRIDAY AND INCREASE
CHANCES FOR WIDESPREAD PRECIPITATION GOING INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM EST WEDNESDAY...QUASI ZONAL UPPER FLOW MIGRATING OVER
THE SOUTHEAST WHILE CANADIAN HIGH PRESSURE DIVES SOUTHWARD THROUGH
THE MS RIVER VALLEY INTO THE OH/TN VALLEYS. MODEST WEST/NORTHWEST
850MB FLOW ALONG THE CENTRAL APPS CONTINUES TO YIELD SCATTERED
SHOWERS ACROSS PORTIONS OF EASTERN KY NORTHWARD INTO WEST VIRGINIA.
ALTHOUGH AMPLE MOISTURE REMAINS FURTHER SOUTH ACROSS PORTIONS OF
WESTERN NC...WEAKER FLOW CONTINUES TO LIMIT COVERAGE. LATEST
NAM/GFS REMAIN PERSISTENT IN SUGGESTING INCREASING SHOWER COVERAGE
ALONG THE TN LINE NORTH OF INTERSTATE 40 THROUGH MID MORNING.
HOWEVER...HIGH RES GUIDANCE SUCH AS THE HRRR CONTINUES TO BACK OFF.
ALL SAID...WILL KEEP LOW END SLIGHT CHANCE POPS FOR ISOLATED SHOWERS
ACROSS THE NORTHERN MTNS THROUGH 12Z. FCST DOES FEATURE BRIEF
PERIOD OF FZRA FOR THESE ZONES AS MODEST INVERSION ALOFT SUGGESTS
PRECIP WILL FALL AS LIQUID WITH SOME FREEZING POSSIBLE TOWARD
MORNING LOWS. NOT EXPECTING ANY SIGNIFICANT IMPACTS BUT CANNOT RULE
OUT A FEW PATCHES OF BLACK ICE.
BEYOND THAT...HIGH PRESSURE WILL PREVAIL ACROSS THE REGION WITH
MOSTLY SUNNY SKIES DOMINATING OVER THE LOW TERRAIN. DID KEEP
MENTION OF MOSTLY/PARTLY CLOUDY SKIES ACROSS THE HIGH TERRAIN AS
WEAK WESTERLY UPSLOPE FLOW CONTINUES AMONGST SHALLOW MOIST LAYER.
MEANWHILE ANOTHER WEAK UPPER IMPULSE WILL BE SLIDING THROUGH THE
SOUTHERN PLAINS ALLOWING SOME HIGH LEVEL CIRRUS TO MOVE OVER THE
FCST AREA THIS AFTERNOON THROUGH PERIODS END. DOWNSLOPING FLOW WILL
YIELD NORMAL LEVEL HIGH TEMPERATURES ACROSS THE FOOTHILLS/PIEDMONT
REGIONS WHILE SLIGHTLY BELOW NORMAL HIGHS ARE FCST OVER THE MTNS.
LOWS TONIGHT WILL BE NEAR NORMAL AS ABOVE MENTIONED INCREASING HIGH
LEVEL CIRRUS LIMITS RADIATIONAL COOLING.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 325 AM WEDNESDAY...A WEAK SHORT WAVE WILL MOVE THRU THE ZONAL
FLOW ALOFT THU. THERE IS VERY LITTLE DEEP MOISTURE OR FORCING WITH
THIS SYSTEM. CANNOT RULE OUT A FEW SPRINKLES ACROSS THE NC MTNS
WHERE WLY FLOW MAY BE ABLE TO SQUEEZE THEM OUT OF THE MOISTURE.
THERE SHUD BE QUITE A BIT OF CLOUDS ACROSS THE AREA HOWEVER. SHORT
WAVE RIDGING DEVELOPS AHEAD OF THE NEXT WX SYSTEM APPROACHING FROM
THE SW ON FRI. THIS WILL BRING AN INCREASE IN CLOUDS THRU THE DAY
AFTER THE THU NITE CLEARING FROM THE DEPARTING SHORT WAVE. HIGHS
WILL BE NEAR NORMAL BOTH DAYS...WHILE LOWS THU NITE WILL BE A FEW
DEGREES ABOVE NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 355 AM WEDNESDAY...GUIDANCE REMAINS IN GOOD AGREEMENT ON THE
OVERALL PATTERN FOR THE WEEKEND STORM SYSTEM...BUT SOME DIFFERENCES
REMAIN REGARDING THE TEMPERATURE PROFILE AND RESULTING P-TYPES. A
SHORT WAVE APPROACHES THE AREA FRI NITE...MOVES ACROSS THE AREA SAT
AND EAST ON SAT NITE. AT THE SFC...A LOW PRESSURE SYSTEM MOVES EAST
ALONG THE GULF COAST WHILE HIGH PRESSURE SETS UP OVER THE AREA IN A
COLD AIR DAMMING CONFIGURATION. PRECIP CHC INCREASES FROM THE SW FRI
NITE AS MOISTURE MOVES IN AHEAD OF THIS SYSTEM...CAT POP DEVELOPS
ALL AREAS SAT AS THE LOW MOVES SOUTH OF THE AREA...WITH POP SLOWLY
TAPERING OFF SAT NITE AND ENDING ON SUN. THE GFS IS WARMER THAN THE
ECMWF...BUT THE ECMWF IS NOT VERY COLD. USING A BLEND OF THESE TWO
MDLS FOR TEMPS AND THICKNESSES RESULTS IN COLDEST TEMPS AND
THICKNESSES ALONG THE NRN TIER OF THE CWFA...POSSIBLY EXTENDING
SOUTH ALONG THE BLUE RIDGE TO THE SC BORDER. EVEN THEN...P-TYPE
SEEMS TO FAVOR A WINTRY MIX FOR THE NRN BLUE RIDGE AND FREEZING RAIN
EAST AND SOUTH OF THERE. RAIN IS THE P-TYPE FOR MOST OF THE CWFA.
CANNOT RULE OUT ADVISORY LEVEL ICE ACCUMS FOR THE NRN MTN LOCATIONS
LATE FRI NITE AND SAT MORN. HAVE GONE WITH RAIN OR SNOW AS PRECIP
COMES TO AN END SAT NITE AND SUN MORN...BUT THIS AND ANY POTENTIAL
ACCUMS ARE MUCH MORE UNCERTAIN. LOWS WILL BE ABOVE NORMAL FRI AND
SAT NITES...WITH HIGHS SAT 10 DEGREES BELOW NORMAL...RISING TO A FEW
DEGREES BELOW NORMAL ON SUN.
GUIDANCE BEGINS TO DIVERGE FOR THE REST OF THE MEDIUM RANGE. A DEEP
TROF DEVELOPS ACROSS THE CENTRAL CONUS...BUT THE ECMWF IS SLOWER AND
DEEPER WITH THE TROF THAN THE GFS. THE GFS ALSO BRINGS SOME WEAK
SHORT WAVE ENERGY ACROSS THE AREA AHEAD OF THE TROF ON MON...WHILE
THE ECMWF DAMPENS THE WAVE SIGNIFICANTLY. AT THE SFC...THE GFS HAS A
WELL DEFINED LOW PRESSURE SYSTEM WELL SOUTH OF THE AREA ACROSS
FLORIDA AND MOVES IN INTO THE ATLANTIC...KEEPING OUR CWFA RELATIVELY
DRY...WHILE THE ECMWF HAS A LESS DEFINED SFC LOW...BUT A STRONGER
BAROCLINIC ZONE CLOSER TO THE CWFA SPREADING PRECIP IN FROM THE
SOUTH. GIVEN THE DISCREPANCIES...HAVE KEPT MON BASICALLY DRY WITH
TEMPS NEAR NORMAL.
PRECIP SPREADS BACK INTO THE AREA TUE AS A FRONTAL SYSTEM ASSOCIATED
WITH THE UPPER TROF MOVES BACK INTO THE AREA FROM THE WEST.
HOWEVER...DETAILS DIFFER ON EXACT TIMING AND THERMAL STRUCTURE.
THEREFORE...HAVE CHC POP SPREADING IN FROM THE WEST TUE. AGAIN...
GIVEN THE DIFFERENCES...USED RAIN/SNOW FOR THE P-TYPE WHICH WOULD
INDICATE SOME SNOW AT ONSET ACROSS THE NC MTNS...BUT THIS IS ALSO
HIGHLY UNCERTAIN. TEMPS TUE NEAR NORMAL.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. ZONAL FLOW
ALOFT AND WEAK HIGH PRESSURE AT THE SURFACE WILL KEEP SKIES CLEAR
AMIDST WNW FLOW THROUGH THE OVERNIGHT. MODELS HINT AT WEAK LEE TROF
DEVELOPMENT BY MID MORNING ALLOWING FLOW TO BACK ALMOST DUE WEST
THROUGH THE AFTERNOON. KEPT WINDS JUST NORTH OF WEST UNTIL 02Z WHEN
FLOW VEERS NORTHERLY. EITHER WAY...WINDS WILL GENERALLY BE LESS
THAN 5KTS. SKIES WILL INCREASE IN THE MID/UPPER LEVELS AS CIRRUS
STREAMS IN ALOFT FROM UPSTREAM MOISTURE PLUME ASSOCIATED WITH WEAK
UPPER WAVE.
ELSEWHERE...VERY SIMILAR TO KCLT ABOVE WITH VFR PREVAILING AT ALL
SITES WITH THE POSSIBLE EXCEPTIONS BEING AT KAVL AND KHKY. ALL TAFS
INITIALIZE VFR WITH MVFR TEMPOS AT KAVL FOR MVFR LEVEL CIGS
ADVECTING IN FROM THE TN LINE...AND ALSO AT KHKY WHERE GUIDANCE
FAVORS LIGHT PATCHY BR RESTRICTIONS. OTHERWISE...SOLIDLY VFR WITH
FLOW REMAINING LIGHT AND NORTHERLY THROUGH MORNING BEFORE LEE TROF
BACKS FLOW WESTERLY DURING THE DAY. FLOW WILL ONCE AGAIN VEER
NORTHERLY LATE IN THE DAY WITH MID/HIGH LEVEL CIRRUS STREAMING IN.
OUTLOOK...A WEAK UPPER DISTURBANCE WILL SLIDE THROUGH THE REGION ON
THURSDAY WITH LITTLE/NO IMPACT EXPECTED. ANOTHER MORE ORGANIZED
SYSTEM WILL APPROACH FROM THE WEST FOR THE START OF THE WEEKEND ONCE
AGAIN INCREASING PRECIP/RESTRICTION CHANCES. SOME WINTRY PRECIP IS
POSSIBLE ACROSS THE NC MOUNTAINS/FOOTHILLS AFFECTING BOTH KAVL AND
KAND SATURDAY MORNING. WINTRY PRECIP IS NOT EXPECTED AT THIS TIME
FOR ANY OTHER TAF SITES.
CONFIDENCE TABLE...
09-15Z 15-21Z 21-03Z 03-06Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL MED 75% HIGH 100% HIGH 100% HIGH 100%
KHKY MED 77% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...CDG
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...CDG
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1157 PM CST TUE DEC 16 2014
.DISCUSSION...
SHORT TERM SOLUTIONS HAVE TRENDED A LITTLE DRIER IN CRITICAL MID
LAYER OF ATMOSPHERE...AND THUS HAVE BACKED OFF SOMEWHAT ON SHOWER
PROSPECTS SPREADING INTO KLBB AND KPVW JUST AFTER DAYBREAK
WEDNESDAY. WE WILL NOT INCLUDE SHOWER MENTION FOR THIS VERSION OF
THE TAF. FOR KCDS...SOLUTIONS NOT IN GOOD ENOUGH AGREEMENT ON
SHOWER PROSPECTS THERE AS WELL FOR LATER ON WEDNESDAY ALTHOUGH
BETTER CHANCE FOR BEING NEARBY. STILL...WITHHOLDING SHOWERS FROM
KCDS AS WELL. OTHERWISE EXPECT MVFR CEILINGS TO TAKE HOLD FOR BOTH
KPVW AND KLBB EARLY IN THE MORNING AND NOT LET GO UNTIL EARLY OR
MID AFTERNOON. MVFR MORE OF AN OUTSIDE RISK FOR KCDS...BUT BETTER
IF SHOWERS DO COME TOGETHER AFTER ALL. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 524 PM CST TUE DEC 16 2014/
AVIATION...
LOW LEVEL MOISTURE EXPANDING NORTH A LITTLE AHEAD OF SCHEDULE
LEADING TO A DECK NEAR 4000 FEET ABOVE THE GROUND AT KLBB AND SOON
TO SPREAD TO KPVW. SATELLITE AND RAP SOLUTIONS SUGGEST THERE MAY
BE A BREAK SKIRTING CLOSE TO BOTH KLBB AND KPVW BY MID EVENING BUT
UNCLEAR IF CEILING WILL BREAK...CHOSE TO KEEP A CONSTANT LAYER FOR
NOW. THIS LAYER SHOULD SPREAD INTO KCDS AS WELL BY MID EVENING.
SATELLITE SHOWS A WELL DEFINED IMPULSE CROSSING NORTHERN BAJA
CALIFORNIA AT THIS TIME AND NOW FORECAST TO LIFT INTO THE WESTERN
SOUTH PLAINS BY MID TO LATE WEDNESDAY MORNING. BOTH RAP AND
WRF/NAM NOW DEPICT MODEST ISENTROPIC LIFT AND LOWERING OF CLOUD
DECKS FOR KPVW AND KLBB NEAR OR JUST AFTER SUNRISE WEDNESDAY...AS
WELL AS SHOWERS DEVELOPING NEARBY. WE WILL WATCH SOLUTION TRENDS
ON THIS AND DECIDE BY THE 06Z TAF IF SHOWERS AND A CLOUD DECK
LOWERING TO NEAR THE BOTTOM OF MVFR LEVELS WORTHY TO INCLUDE FOR
THE NEXT ISSUANCE. RMCQUEEN
PREV DISCUSSION... /ISSUED 300 PM CST TUE DEC 16 2014/
SHORT TERM...
INCREASING LOW LEVEL MOISTURE ADVECTION AHEAD OF AN UPPER TROUGH...
LOCATED JUST OFF THE SRN CALI/BAJA CALI COAST AS OF EARLY AFTN...TO
SPREAD STRATUS ACROSS THE FCST OVERNIGHT. THIS MAY END UP OCCURRING
MORE QUICKLY THAN PREVIOUSLY ANTICIPATED AS A BATCH LOW CLOUDS
CONTINUES TO MOVE NWD THROUGH THE PERMIAN BASIN WITH LITTLE HINT
ATTM OF DISSIPATING THIS AFTN. THE MAIN UPPER TROUGH PROGGED TO HOLD
BACK ACROSS THE WRN CONUS INTO WEDNESDAY NIGHT BEFORE DAMPENING
SIGNIFICANTLY AND EJECTING EWD THURSDAY. BEFORE THEN AN INITIAL
SHORT WAVE TROUGH PROGGED TO EJECT ACROSS THE HIGH PLAINS AND AS
THIS UPPER TROUGH APPROACHES CHANCES FOR LIGHT RAIN SHOWERS WILL
INCREASE. WRF-NAM AND ITS ASSOCIATED MOS GUIDANCE WITH POPS CLOSER
TO 30 PCT NOT COMPLETELY UNFOUNDED...BUT APPEARS TO PLAY INTO THE
MODEL BIAS OF OVERPRODUCING LIGHT PRECIP WITH ABUNDANT LOW LEVEL
MOISTURE IN PLACE. ALSO...LAST SEVERAL SYSTEMS HAVE BEEN
DISAPPOINTMENTS RELATIVE TO THE MODEL PROGS AND MOS OUTPUT. THAT
SAID...PREVIOUS FCST LOOKS FINE ATTM WITH SLIGHT CHANCE POPS EAST
AFTER 12Z WEDNESDAY. TEMPS A LESSER CONCERN WITH A RELATIVELY MILD
NIGHT NEAR OR JUST ABOVE MOS LOOKING GOOD. HIGHS WEDNESDAY A BIT
TRICKY AND WILL DEPEND MUCH ON HOW QUICKLY SKIES CLEAR BEHIND THE
TROUGH. SOME SORT OF BLEND BETWEEN MET AND MAV MOS NUMBERS WITH A
SLIGHT NUDGE TO THE WARMER END IS REASONABLE ATTM.
LONG TERM...
A NEG TILTED SHORTWAVE WILL BE POSITIONED OVER THE FA EARLY THURSDAY
WITH MOST OF ITS ENERGY PLACED JUST TO OUR EAST. THE SHORTWAVE WILL
BE QUICKLY KICKED OUT OF THE AREA BY AN APPROACHING TROF FROM THE
WEST. OVERALL MODELS CONTINUE TO HAVE A LESS AMPLIFIED TROF BY
FRIDAY WITH THE EXCEPTION OF THE NAM AND CMC WHICH HAVE A DEEPER AND
SHARPER TROF. MINUS THE CMC...THE GLOBAL MODELS APPEAR TO BE
HANDLING THE TROF BETTER IN THE SYNOPTIC SCALE. THE BIGGER
DIFFERENCES ARE WITH MOISTURE RETURN/AVAILABILITY. THE GFS IS
SOMEWHAT OF AN OUTLIER HAVING A DRY FORECAST DESPITE TROPICAL
MOISTURE FLOWING IN FROM THE PACIFIC. FOR NOW POPS HAVE BEEN KEPT IN
FOR FRIDAY AS LIFT AND MOISTURE SHOULD BE SUFFICIENT ENOUGH FOR
PRECIP. ONE OF THE BIGGER QUESTIONS FOR THIS PERIOD IS PRECIP TYPE.
MOST OF THE FA SHOULD SEE LIQUID PRECIP. THE EXCEPTION TO THAT WOULD
BE ACROSS OUR NORTHWESTERN ZONES WHERE FORECAST SOUNDINGS SHOW TEMPS
ALOFT COOLING ENOUGH TO PRODUCE SNOW AS THE AXIS OF THE TROF MOVES
OVERHEAD FRIDAY MORNING. SURFACE TEMPS SHOULD DROP TO BELOW FREEZING
BY THIS TIME...HOWEVER LITTLE TO NO ACCUMULATION WOULD BE EXPECTED
AS SOIL TEMPS WOULD HAVE NO TIME TO RESPOND AND WOULD STAY ABOVE
FREEZING. THIS TROF WILL QUICKLY PUSH EAST BY SATURDAY WHILE ANOTHER
TROF...THIS ONE DEEPER THAN ITS PREDECESSOR...MOVES INTO THE REGION.
SOME SHOWERS WILL STILL BE POSSIBLE SUNDAY NIGHT WITH THIS SYSTEM
BUT WOULD MOST LIKELY BE LIGHT AS LIFT WILL BE RELATIVELY WEAK DUE
TO THE POS TILT OF THE TROF. THE TROF WILL GIVE WAY TO NORTHWESTERLY
FLOW BY EARLY NEXT WEEK WHICH SHOULD HELP KEEP TEMPS AROUND SEASONAL
AVERAGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 28 53 30 53 29 / 10 10 0 10 30
TULIA 32 48 33 51 31 / 10 10 0 10 30
PLAINVIEW 32 50 33 54 32 / 10 10 0 10 30
LEVELLAND 35 57 33 58 32 / 10 10 0 10 30
LUBBOCK 35 55 35 58 34 / 10 10 0 10 30
DENVER CITY 36 58 35 60 35 / 10 10 0 10 30
BROWNFIELD 36 57 35 59 34 / 10 10 0 10 30
CHILDRESS 33 47 36 53 36 / 10 20 10 10 30
SPUR 35 51 37 59 35 / 10 20 10 10 40
ASPERMONT 38 52 39 62 38 / 10 20 10 10 40
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/05
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1046 PM MST TUE DEC 16 2014
.UPDATE...
ISSUED AT 813 PM MST TUE DEC 16 2014
LATEST RADAR LOOP SHOWS A BAND OF LIGHT SNOW SHOWERS LIFTING INTO
THE SOUTHERN NE PANHANDLE FROM NORTHEAST CO. THIS APPEARS TO BE
ASSOCIATED WITH A WEAK MIDLVL DISTURBANCE TRAVERSING THE CENTRAL
HIGH PLAINS ATTM. WITH SOME BANDING OWING TO WEAK FRONTOGENESIS
AROUND H7...COULD SEE A DUSTING OF SNOW ALONG AND SOUTH OF THE I80
CORRIDOR IN NE TONIGHT. ADDED A SLIGHT CHANCE OF SNOW THROUGH 06Z
WED. FOG IS STILL A CONCERN FOR THE OVERNIGHT HOURS. LOWEST VSBYS
SO FAR HAVE BEEN ALONG THE PLATTE RIVER WITH MOIST UPVALLEY WINDS
OUT OF THE EAST/SOUTHEAST. THESE AREAS SAW THE MOST SNOW WITH THE
RECENT STORM AS WELL...SO THERE IS PLENTY OF BLYR MOISTURE TO GO
AROUND. THE HRRR STILL SUGGESTS PATCHY FOG WILL LIKELY EXPAND TO
OTHER PARTS OF EAST CENTRAL WY AND THE WESTERN PANHANDLE
OVERNIGHT...EXCEPT ADJACENT TO THE LARAMIE RANGE WHERE THE LLVLS
SHOULD STAY MORE MIXED. LIGHT WEST WINDS AND AMPLE LLVL MOISTURE
COULD RESULT IN PATCHY FOG WEST OF THE LARAMIE RANGE AS WELL.
INCREASED TEMPERATURES A FEW DEGREES OVER THE PANHANDLE WITH LOW
STRATUS MINIMIZING THE POTENTIAL FOR RADIATIONAL COOLING. ONLY
OTHER CHANGES WERE TO ADJUST SKY TRENDS AND THE TIMING/INTENSITY
OF FOG.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 243 PM MST TUE DEC 16 2014
TONIGHT...MOST WIDESPREAD CHALLENGE WILL BE FOG
DEVELOPMENT...INCLUDING AREAL COVERAGE AND VISIBILITIES. WHERE FOG
WAS SLOWEST TO ERODE...FROM TORRINGTON...TO SCOTTSBLUFF AND TO
ALLIANCE...INCLUDING OVER THE SNOWFIELD...3 PM TEMPERATURE AND
DEWPOINT SPREADS ARE ONLY 2 TO 5 DEGREES WITH CLEARING MID LEVEL
SKIES NOTED ON VISIBLE SATELLITE IMAGERY...THUS EXPECT FOG TO
DEVELOP RATHER QUICKLY AND SPREAD OVER AFOREMENTIONED LOCALES IN
THE LATE AFTERNOON AND EARLY EVENING HOURS.
LOW LEVELS AND BOUNDARY LAYER SATURATE UP DECENTLY
OVERNIGHT...ESPECIALLY OVER OUR WESTERN COUNTIES OF CARBON AND
ALBANY...AND MID AFTERNOON TEMPERATURE DEWPOINT SPREADS ARE ONLY
AROUND 7 DEGREES AT RAWLINS AND LARAMIE...ALONG WITH MID LEVEL
CLEARING PROGGED...THUS EXPECT RATHER EXTENSIVE FOG TO DEVELOP LATE
THIS EVENING AND OVERNIGHT ACROSS OUR WESTERN COUNTIES.
NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT MOVES FROM WESTERN WYOMING
THIS AFTERNOON...TO NORTHWEST WYOMING BY MIDNIGHT AND TO CENTRAL
MONTANA BY DAYBREAK...BASED ON SATELLITE AND RADAR TRENDS...EXPECT
INCREASING AREAL COVERAGE OF SNOW SHOWERS THIS EVENING ACROSS OUR
WYOMING COUNTIES...ESPECIALLY OVER AND NEAR THE SNOWY AND SIERRA
MADRE RANGES...WITH A SLOW CESSATION AND DECREASE IN AREAL SNOW
COVERAGE LATE THIS EVENING AND OVERNIGHT. MAY EVEN SEE A FEW
FLAKES ALONG AND EAST OF INTERSTATE 25...THOUGH COVERAGE LOOKS
QUITE MINIMAL.
WEDNESDAY...SPLIT TROUGHS ALOFT MOVE ACROSS OUR REGION WITH THE
BULK OF SNOW AND DEEPER MOISTURE LOCATED OVER COLORADO...THOUGH
OUR SNOWY AND SIERRA MADRE RANGES WILL SEE SCATTERED OROGRAPHIC
SNOW SHOWERS...MOSTLY DRY ELSEWHERE.
WEDNESDAY NIGHT...NORTHERN STREAM SHORTWAVE TROUGH ALOFT MOVES OVER
THE WESTERN DAKOTAS...WITH THE SOUTHERN STREAM SHORTWAVE TROUGH
ALOFT MOVING OVER WESTERN KANSAS...THUS MINIMAL COVERAGE OF SNOW
SHOWERS OVER OUR COUNTIES...MAINLY OVER THE SNOWY AND SIERRA MADRE
RANGES...DRY ELSEWHERE.
THURSDAY...PSEUDO CYCLONIC FLOW ALOFT CONTINUES OVER OUR COUNTIES
WITH ONE SHORTWAVE ALOFT OVER THE FOUR CORNERS WITH MOST OF THAT
SHORTWAVE TROUGH SNOW OVER WESTERN COLORADO...THOUGH WILL SEE SOME
OROGRAPHIC SNOW SHOWERS OVER OUR SNOWY AND SIERRA MADRE RANGES...
DRY ELSEWHERE.
THURSDAY NIGHT...FAST MOVING...MOISTURE STARVED SHORTWAVE TROUGH
ALOFT MOVES ACROSS OUR COUNTIES...THOUGH WITH MINIMAL LOW AND MID
LEVEL MOISTURE...ONLY SOME ISOLATED MOUNTAIN SNOW SHOWERS ON TAP.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 243 PM MST TUE DEC 16 2014
SHORTWAVE TROUGH WILL MOVE OVERHEAD ON FRIDAY UNDER WEAK NORTHWEST
FLOW. MODELS KEEP THE HIGHEST LLVL MOISTURE OVER THE MOUNTAINS THRU
THE DAY WHICH IS REASONABLE IN THIS FLOW PATTERN...SO KEPT SNOW
CHANCES CONFINED TO THE SNOWY AND SIERRA MADRES MOUNTAINS. ANOTHER
WEAK SHORTWAVE TROUGH WILL MOVE THROUGH ON SATURDAY/SATURDAY NIGHT
WITH A SLIGHTLY MORE NORTHERLY TRACK...SO COULD SEE LIGHT SNOW
SHOWERS RETURNING TO THE MOUNTAINS INCLUDING THE NORTHERN LARAMIE
RANGE THROUGH THIS TIME. WINDS ALOFT WILL BEGIN TO INCREASE SUNDAY
AND MONDAY AS A STRONG EASTERN PAC HIGH BUILDS IN FROM THE WEST. THE
STORM TRACK WILL THUS SHIFT OVER THE NORTHERN ROCKIES AND HIGH
PLAINS THROUGH THE EARLY PART OF THE WEEK...WITH WINDY CONDITIONS
AND INCREASING COVERAGE OF SNOW SHOWERS EXPECTED. THE NOSE OF A 150+
KT JET WILL MOVE OVERHEAD MONDAY...WITH A RATHER VIGOROUS VORT MAX
MOVING FROM THE NORTHERN ROCKIES INTO THE CENTRAL PLAINS IN THE LFQ
REGION OF THE JET. STILL LOOKS FAVORABLE FOR MORE WIDESPREAD SNOW
SHOWERS OVER THE CWA ON MONDAY...ESPECIALLY OVER THE MOUNTAINS AND
NORTHERN PLAINS FROM DOUGLAS TO ALLIANCE IN BETTER PROXIMITY TO THE
JET DIFLUENCE AND LIFT FROM THE VORT MAX. THE LLVL GRADIENT WILL
INCREASE IN ADVANCE OF THE WAVE AS THE LEESIDE TROUGH DEEPENS AS
WELL...SO SHOULD ALSO SEE WINDS BECOME MODERATE TO STRONG LATE
SUNDAY THROUGH MONDAY. THE ASSOCIATED COLD FRONT WILL MOVE ACROSS
THE EASTERN PLAINS SOMETIME LATE MONDAY...AND SHOULD STALL HERE
THROUGH TUESDAY. WINDY CONDITIONS WITH CHANCES FOR LIGHT SNOW WILL
CONTINUE OVER THE MOUNTAINS WITH RAIN/SNOW MIX OVER THE PLAINS AS A
RESULT. TEMPS THROUGH THE PERIOD WILL REMAIN AROUND NORMAL FOR THIS
TIME OF YEAR...WITH A SLIGHT BUMP UPWARDS AS DOWNSLOPE WINDS KICK IN
FOR MONDAY AND TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1040 PM MST TUE DEC 16 2014
LOW STRATUS AND PATCHY FOG WILL CONTINUE TO BE THE MAIN AVIATION
HAZARD THIS TAF PERIOD. MVFR TO IFR CIGS/VSBYS ARE POSSIBLE THRU
THE NIGHT...MAINLY OVER THE NEBRASKA TERMINALS. THERE MAY BE A
BRIEF PERIOD OF IMPROVING CONDITIONS AROUND 15-18Z BEFORE MOISTURE
INCREASES AGAIN IN THE AFTERNOON. IFR CIGS COULD REMAIN IN PLACE
OVER KAIA THROUGH WED NIGHT.
&&
.FIRE WEATHER...
ISSUED AT 243 PM MST TUE DEC 16 2014
MINIMAL ISSUES DUE TO PROJECTED HUMIDITIES AND WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLH
SHORT TERM...RUBIN
LONG TERM...RJM
AVIATION...CLH
FIRE WEATHER...RUBIN
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1003 AM CST WED DEC 17 2014
.SHORT TERM...
315 AM CST
THROUGH THURSDAY...
THE SYSTEM THAT BROUGHT A RETURN TO MORE SEASONAL TEMPERATURES IS
NOW CENTERED OVER THE EASTERN GREAT LAKES. THIS UPPER LOW IS
ROTATING AROUND A NOW DEEPER BUT SHEARING UPPER LOW CENTERED OVER
MINNESOTA AND WISCONSIN EARLY THIS MORNING. AT THE LOW-LEVELS THIS
SLOW MOVING PATTERN IS HELPING KEEP COLD AIR ADVECTION IN PLACE.
WHILE NOT PARTICULARLY STRONG FOR DECEMBER...THIS ADVECTION WITHIN
CYCLONIC FLOW HAS HELPED KEEP THE CLOUDS AND EVEN SOME FLURRIES.
EARLY MORNING SATELLITE IMAGERY INDICATES THE BACK EDGE CLEARING
FROM MINNEAPOLIS TO DES MOINES AND MAKING LITTLE PROGRESS. UPSTREAM
00Z SOUNDINGS AND CURRENT ACARS DATA FROM RFD INDICATE THE MOISTURE
DEPTH IS VERY SHALLOW. SO CERTAINLY THERE IS POTENTIAL TO SCATTER
FROM WEST TO EAST TODAY AND HIGH RESOLUTION GUIDANCE AND CONDENSATE
FIELDS DO PAINT THIS PICTURE AS WELL. GIVEN FURTHER STRENGTHENING OF
THE SUBSIDENCE INVERSION ON FORECAST SOUNDINGS ACROSS NORTH CENTRAL
ILLINOIS...HAVE GONE WITH FORECAST SCATTERING THERE BY EARLY
AFTERNOON. A LITTLE MORE TRICKY TOWARD CHICAGO AND NORTHWEST INDIANA
AND HAVE FAVORED THAT AREA REMAINING AT LEAST MOSTLY CLOUDY THROUGH
MUCH OF TODAY.
HIGH TEMPERATURES TODAY LOOK TO BE THEIR COOLEST IN ABOUT A WEEK
WITH UPPER 20S AND LOWER 30S SUPPORTED GIVEN LITTLE DIURNAL CLIMB
EXPECTED. THIS IS JUST A TAD BELOW MID-DECEMBER NORMALS. AS FOR
TONIGHT...LIKE A SONG ON REPEAT...THE CONFIDENCE ON CLOUDS ONCE
AGAIN IS LOW. WHILE SOME AREAS MAY SEE NOT MUCH FOR CLOUDS IN THE
EVENING...HIGH CLOUDS LOOK TO MOVE NORTHWARD OVER THE AREA LATE
TONIGHT. WITH LIGHTER WINDS THE POTENTIAL EXISTS FOR TEMPERATURES TO
DROP INTO THE LOWER TO MID TEENS IN OUTLYING AREAS.
THE GREAT LAKES BROAD UPPER LOW WILL MOVE EAST ON THURSDAY WEAKENING
THE CONFLUENT UPPER FLOW OVER THE FORECAST AREA. THIS WILL HELP A
SOUTHERN STREAM SYSTEM...CENTERED IN EASTERN ARIZONA EARLY THIS
MORNING...TO MAKE SOME INROADS WITH MID-LEVEL WARM AND MOIST
ADVECTION UP TO AT LEAST CENTRAL ILLINOIS AND INDIANA. THIS SHOULD
BRING CLOUDS TO MUCH OF THE AREA. HAVE NOT INCLUDED ANY LIGHT SNOW
IN THE FAR SOUTHERN AREA AT THIS TIME AS THE SUPPORT FOR LIFT STAYS
JUST SOUTH ON MOST GUIDANCE SOLUTIONS.
MTF
&&
.LONG TERM...
315 AM CST
FRIDAY THROUGH TUESDAY...
SURFACE HIGH PRESSURE RIDGING BASICALLY MAINTAINS ITSELF OVER THE
AREA THROUGH THE WEEKEND. THE UPPER PATTERN REMAINS SOMEWHAT SPLIT
WITH A SYSTEM LIKELY ENTIRELY PASSING TO OUR SOUTHEAST ON SATURDAY.
A NORTHERN STREAM UPPER LOW IS FORECAST TO BRING SOME PACIFIC
MOISTURE...MAINLY ALOFT...OVER THE AREA SATURDAY EVENING/OVERNIGHT.
LIFT IS WEAK AND MAINLY FOCUSED NORTH SO DO NOT HAVE ANY
POPS...HOWEVER HAVE INCREASED CLOUD COVER IN THE FORECAST AND WITH
THAT FORECAST MINS ON SATURDAY NIGHT.
THE WEATHER PATTERN ACROSS THE CENTRAL CONUS HAS BEEN CONSISTENTLY
FORECAST BY LONG RANGE MODELS AND ENSEMBLES TO BECOME MORE AMPLIFIED
DURING NEXT WEEK. JUST LOOKING ON HEMISPHERIC WATER VAPOR THIS
MORNING...MULTIPLE SYSTEMS ON ACTIVE JET ARE SEEN ACROSS THE
NORTHERN PACIFIC...SO A PATTERN SHIFT SEEMS LIKELY. THE CONSENSUS OF
GUIDANCE FAVORS AN ANOMALOUS SURFACE REFLECTION TO DEVELOP ACROSS
THE MIDWEST MONDAY INTO TUESDAY...THOUGH AS ONE CAN EXPECT THERE ARE
LARGE DIFFERENCES IN PLACEMENT. HAVE INCREASED FORECAST POPS IN
LINE WITH A SMART GUIDANCE BLEND. GIVEN A CONSENSUS PLACEMENT
THOUGH...IT WOULD SEEM PROFILES WOULD BE MILD ENOUGH FOR MAINLY RAIN
AT FIRST IN OUR AREA. CERTAINLY THIS BECOMES A LOT MORE IN QUESTION
AS THE TROUGH FURTHER AMPLIFIES SUCH AS MODELS SUGGEST INTO
TUESDAY AND CHRISTMAS EVE.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* MVFR CIGS THRU TONIGHT.
* GUSTY WEST/NORTHWEST WINDS THRU EARLY AFTERNOON.
LENNING/CMS
//DISCUSSION...UPDATED 12Z...
MAIN FORECAST CONCERN WILL BE WHEN MVFR CIGS WILL SCATTER OUT.
BACK EDGE STILL ACROSS CENTRAL IA AND EASTERN MN AND MAKING VERY
SLOW PROGRESS TO THE SOUTHEAST. FORECAST SOUNDINGS STILL SUGGEST
INVERSION ALOFT WILL BE STRONG ENOUGH TO TRAP THESE CLOUDS FOR
MOST OF THE DAYLIGHT HOURS AND POSSIBLY INTO THIS EVENING. SO
OPTED TO MAINTAIN MVFR CIGS INTO TONIGHT WITH SOME SCATTERING OR
CLEARING POSSIBLE OVERNIGHT...WHICH WILL LIKELY OCCUR FIRST AT RFD
AND POSSIBLY AS EARLY AS THIS EVENING.
A FEW FLURRIES WILL BE POSSIBLE THIS MORNING...BUT NO RESTRICTIONS
TO VIS EXPECTED.
WEST/NORTHWEST WINDS HAVE DIMINISHED SOME DURING THE EARLY MORNING
HOURS AND EXPECT THEM TO REMAIN GENERALLY STEADY INTO THIS
AFTERNOON...IN THE 10-15KT RANGE WITH GUSTS INTO THE MID/UPPER
TEENS. WINDS WILL SLOWLY DIMINISH THIS AFTERNOON THROUGH TONIGHT
AS THE GRADIENT SLOWLY WEAKENS. CMS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM FOR CIGS THRU THE PERIOD.
* HIGH FOR WINDS THRU THE PERIOD.
LENNING/CMS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT THROUGH SATURDAY...DRY/VFR. LIGHT/VRB WINDS.
* SUNDAY...DRY. MVFR POSSIBLE. SOUTH WINDS.
* MONDAY...CHANCE OF RAIN. MVFR LIKELY. GUSTY SOUTH WINDS.
* TUESDAY...CHANCE OF RAIN. IFR POSSIBLE. SOUTHWEST WINDS.
&&
.MARINE...
210 AM...LOW PRESSURE NEAR LAKE ONTARIO WILL MOVE EAST AND BE
ABSORBED BY LOW PRESSURE MOVING NORTH ALONG THE NEW ENGLAND COAST.
THIS LOW WILL THEN SLOWLY LIFT NORTHEAST AND DEEPEN OVER THE NEXT
FEW DAYS. A LARGE AREA OF HIGH PRESSURE EXTENDING FROM MANITOBA
INTO THE CENTRAL PLAINS WILL SLOWLY BUILD EAST ACROSS THE LAKES
REGION THURSDAY AND FRIDAY. NORTHWEST WINDS TO 30 KTS IN BETWEEN
THESE TWO SYSTEMS WILL GRADUALLY DIMINISH TONIGHT INTO THURSDAY.
AS THE HIGH DRIFTS ACROSS THE LAKES REGION...THERE WILL BE A
PERIOD OF LIGHT PERHAPS EVEN CALM WINDS FRIDAY NIGHT INTO SATURDAY
NIGHT UNTIL THE HIGH MOVES EAST SUNDAY AND SUNDAY NIGHT AND THE
FLOW TURNS BACK SOUTHERLY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 10 AM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
950 AM CST Wed Dec 17 2014
.UPDATE...
ISSUED AT 950 AM CST WED DEC 17 2014
Clouds continue to blanket central and southeast Illinois this
morning, thanks to low-level moisture trapped beneath a subsidence
inversion at around 900mb. Enough synoptic lift is being generated
by a short-wave trough sinking southward through Wisconsin to trigger
a few snow flurries across the area. Radar imagery has shown some
weak echoes from near Peoria southeastward along the I-74
corridor, with both KBMI and KCMI reporting flurries at some
point this morning. Have updated the forecast to include scattered
flurries across the northern KILX CWA accordingly. Main question
of the day will be whether or not any clearing will occur. Latest
visible satellite imagery shows clearing across much of Iowa, as
well as central/southern Missouri. Based on timing tools, skies
will clear across the Illinois River Valley this afternoon, then
toward the I-55 corridor by late afternoon/early evening. Have
adjusted sky grids to better reflect current trends, featuring
partly sunny skies across the west this afternoon and continued
overcast conditions further east toward the Indiana border.
&&
.SHORT TERM...(Today)
ISSUED AT 310 AM CST WED DEC 17 2014
A north-south oriented elongated high pressure ridge will edge
eastward toward Illinois today bringing with it a much lighter
surface pressure gradient and subsidence aloft. The result will be
wind speeds and gusts tapering off throughout the day as well as
thinning low cloud cover. Seasonably cold temperatures that arrived
after yesterday`s cold front will continue, with highs today only
around the freezing mark, just a few degrees below normal.
Although cloud cover will thin out through the day, current
indications are that the GFS and HRRR models are too aggressive in
clearing out low level moisture trapped below an inversion based
just below 900 mb. Forecast cloud cover is based more in line with
the NAM which keeps a saturated layer through the early part of
the day, slowly thinning through the afternoon. Meanwhile, periods
of high cloud cover will be arriving in the afternoon as well.
Also watching a band of snow flurries moving southward through Iowa
this morning. This looks as if it will remain west of the central IL
forecast area before the disturbance responsible for it ejects
eastward. This could move through portions of central IL later this
morning, but would be of very little consequence and is a fairly low
probability at this point.
&&
.LONG TERM...(Tonight through Tuesday)
ISSUED AT 310 AM CST WED DEC 17 2014
Upper wave currently pushing through Arizona on track to reach the
southern Plains tonight, before dampening out somewhat as it moves
across Missouri. Forecast soundings off most of the models are
showing the column moistening from the top down overnight, but very
dry air lingers just past sunrise below 800 mb. A short period of
isentropic lift on the 305K plane will move through central Illinois
Thursday morning, coinciding with the moistening of the lower
layers, resulting in a period of light snow across the southwestern
CWA during the morning. Current thinking is only a few tenths from
Rushville through Springfield to the Effingham/Flora areas. The
soundings further northeast toward Peoria and Bloomington generally
never really moisten the lower levels (except for the NAM), and will
keep those areas dry on Thursday.
Model trends for the Friday night/Saturday system continue to shift
more to the south, as the next deepening wave tracks into the lower
Mississippi Valley. Have limited the PoP`s for Friday night and
Saturday morning to areas south of I-70, where accumulations look to
be less than an inch. The ECMWF tries to draw some of the moisture
northward Saturday morning as a separate wave in the northern stream
swings into the Great Lakes region, so have kept some slight chances
during the morning across east central Illinois.
Active period setting up next week, as a broad long wave trough digs
southward through the central U.S. Some timing differences as to the
depth of this wave, with the ECMWF and parallel GFS cutting off a
low over southeast South Dakota and drifting it east, while the
operational GFS waits until mid week to cut off a broad low over the
Midwest. Both solutions yield precipitation as a storm system
organizes just to our northwest. Have continued to concentrate the
precip chances Monday night into Tuesday, mostly rain but perhaps
some snow mixed in across the far north. Will need to watch the
evolution of this closely, with the pre-holiday travel rush
beginning around this time.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
ISSUED AT 528 AM CST WED DEC 17 2014
Widespread MVFR ceilings across central Illinois this morning,
with local IFR near KBMI will gradually erode from west to east
beginning this afternoon. Expect cloud cover to become SCT015-020
west of KDEC-KBMI, continuing BKN015 to the east through tonight.
Winds WNW 8-12 kts this morning decreasing through the afternoon
and evening.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Barnes
SHORT TERM...Onton
LONG TERM...Geelhart
AVIATION...Onton
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
533 AM CST WED DEC 17 2014
.SHORT TERM...
315 AM CST
THROUGH THURSDAY...
THE SYSTEM THAT BROUGHT A RETURN TO MORE SEASONAL TEMPERATURES IS
NOW CENTERED OVER THE EASTERN GREAT LAKES. THIS UPPER LOW IS
ROTATING AROUND A NOW DEEPER BUT SHEARING UPPER LOW CENTERED OVER
MINNESOTA AND WISCONSIN EARLY THIS MORNING. AT THE LOW-LEVELS THIS
SLOW MOVING PATTERN IS HELPING KEEP COLD AIR ADVECTION IN PLACE.
WHILE NOT PARTICULARLY STRONG FOR DECEMBER...THIS ADVECTION WITHIN
CYCLONIC FLOW HAS HELPED KEEP THE CLOUDS AND EVEN SOME FLURRIES.
EARLY MORNING SATELLITE IMAGERY INDICATES THE BACK EDGE CLEARING
FROM MINNEAPOLIS TO DES MOINES AND MAKING LITTLE PROGRESS. UPSTREAM
00Z SOUNDINGS AND CURRENT ACARS DATA FROM RFD INDICATE THE MOISTURE
DEPTH IS VERY SHALLOW. SO CERTAINLY THERE IS POTENTIAL TO SCATTER
FROM WEST TO EAST TODAY AND HIGH RESOLUTION GUIDANCE AND CONDENSATE
FIELDS DO PAINT THIS PICTURE AS WELL. GIVEN FURTHER STRENGTHENING OF
THE SUBSIDENCE INVERSION ON FORECAST SOUNDINGS ACROSS NORTH CENTRAL
ILLINOIS...HAVE GONE WITH FORECAST SCATTERING THERE BY EARLY
AFTERNOON. A LITTLE MORE TRICKY TOWARD CHICAGO AND NORTHWEST INDIANA
AND HAVE FAVORED THAT AREA REMAINING AT LEAST MOSTLY CLOUDY THROUGH
MUCH OF TODAY.
HIGH TEMPERATURES TODAY LOOK TO BE THEIR COOLEST IN ABOUT A WEEK
WITH UPPER 20S AND LOWER 30S SUPPORTED GIVEN LITTLE DIURNAL CLIMB
EXPECTED. THIS IS JUST A TAD BELOW MID-DECEMBER NORMALS. AS FOR
TONIGHT...LIKE A SONG ON REPEAT...THE CONFIDENCE ON CLOUDS ONCE
AGAIN IS LOW. WHILE SOME AREAS MAY SEE NOT MUCH FOR CLOUDS IN THE
EVENING...HIGH CLOUDS LOOK TO MOVE NORTHWARD OVER THE AREA LATE
TONIGHT. WITH LIGHTER WINDS THE POTENTIAL EXISTS FOR TEMPERATURES TO
DROP INTO THE LOWER TO MID TEENS IN OUTLYING AREAS.
THE GREAT LAKES BROAD UPPER LOW WILL MOVE EAST ON THURSDAY WEAKENING
THE CONFLUENT UPPER FLOW OVER THE FORECAST AREA. THIS WILL HELP A
SOUTHERN STREAM SYSTEM...CENTERED IN EASTERN ARIZONA EARLY THIS
MORNING...TO MAKE SOME INROADS WITH MID-LEVEL WARM AND MOIST
ADVECTION UP TO AT LEAST CENTRAL ILLINOIS AND INDIANA. THIS SHOULD
BRING CLOUDS TO MUCH OF THE AREA. HAVE NOT INCLUDED ANY LIGHT SNOW
IN THE FAR SOUTHERN AREA AT THIS TIME AS THE SUPPORT FOR LIFT STAYS
JUST SOUTH ON MOST GUIDANCE SOLUTIONS.
MTF
&&
.LONG TERM...
315 AM CST
FRIDAY THROUGH TUESDAY...
SURFACE HIGH PRESSURE RIDGING BASICALLY MAINTAINS ITSELF OVER THE
AREA THROUGH THE WEEKEND. THE UPPER PATTERN REMAINS SOMEWHAT SPLIT
WITH A SYSTEM LIKELY ENTIRELY PASSING TO OUR SOUTHEAST ON SATURDAY.
A NORTHERN STREAM UPPER LOW IS FORECAST TO BRING SOME PACIFIC
MOISTURE...MAINLY ALOFT...OVER THE AREA SATURDAY EVENING/OVERNIGHT.
LIFT IS WEAK AND MAINLY FOCUSED NORTH SO DO NOT HAVE ANY
POPS...HOWEVER HAVE INCREASED CLOUD COVER IN THE FORECAST AND WITH
THAT FORECAST MINS ON SATURDAY NIGHT.
THE WEATHER PATTERN ACROSS THE CENTRAL CONUS HAS BEEN CONSISTENTLY
FORECAST BY LONG RANGE MODELS AND ENSEMBLES TO BECOME MORE AMPLIFIED
DURING NEXT WEEK. JUST LOOKING ON HEMISPHERIC WATER VAPOR THIS
MORNING...MULTIPLE SYSTEMS ON ACTIVE JET ARE SEEN ACROSS THE
NORTHERN PACIFIC...SO A PATTERN SHIFT SEEMS LIKELY. THE CONSENSUS OF
GUIDANCE FAVORS AN ANOMALOUS SURFACE REFLECTION TO DEVELOP ACROSS
THE MIDWEST MONDAY INTO TUESDAY...THOUGH AS ONE CAN EXPECT THERE ARE
LARGE DIFFERENCES IN PLACEMENT. HAVE INCREASED FORECAST POPS IN
LINE WITH A SMART GUIDANCE BLEND. GIVEN A CONSENSUS PLACEMENT
THOUGH...IT WOULD SEEM PROFILES WOULD BE MILD ENOUGH FOR MAINLY RAIN
AT FIRST IN OUR AREA. CERTAINLY THIS BECOMES A LOT MORE IN QUESTION
AS THE TROUGH FURTHER AMPLIFIES SUCH AS MODELS SUGGEST INTO
TUESDAY AND CHRISTMAS EVE.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* MVFR CIGS THRU TONIGHT.
* GUSTY WEST/NORTHWEST WINDS THRU EARLY AFTERNOON. CMS
//DISCUSSION...UPDATED 12Z...
MAIN FORECAST CONCERN WILL BE WHEN MVFR CIGS WILL SCATTER OUT.
BACK EDGE STILL ACROSS CENTRAL IA AND EASTERN MN AND MAKING VERY
SLOW PROGRESS TO THE SOUTHEAST. FORECAST SOUNDINGS STILL SUGGEST
INVERSION ALOFT WILL BE STRONG ENOUGH TO TRAP THESE CLOUDS FOR
MOST OF THE DAYLIGHT HOURS AND POSSIBLY INTO THIS EVENING. SO
OPTED TO MAINTAIN MVFR CIGS INTO TONIGHT WITH SOME SCATTERING OR
CLEARING POSSIBLE OVERNIGHT...WHICH WILL LIKELY OCCUR FIRST AT RFD
AND POSSIBLY AS EARLY AS THIS EVENING.
A FEW FLURRIES WILL BE POSSIBLE THIS MORNING...BUT NO RESTRICTIONS
TO VIS EXPECTED.
WEST/NORTHWEST WINDS HAVE DIMINISHED SOME DURING THE EARLY MORNING
HOURS AND EXPECT THEM TO REMAIN GENERALLY STEADY INTO THIS
AFTERNOON...IN THE 10-15KT RANGE WITH GUSTS INTO THE MID/UPPER
TEENS. WINDS WILL SLOWLY DIMINISH THIS AFTERNOON THROUGH TONIGHT
AS THE GRADIENT SLOWLY WEAKENS. CMS
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM FOR CIGS THRU THE PERIOD.
* HIGH FOR WINDS THRU THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT THROUGH SATURDAY...DRY/VFR. LIGHT/VRB WINDS.
* SUNDAY...DRY. MVFR POSSIBLE. SOUTH WINDS.
* MONDAY...CHANCE OF RAIN. MVFR LIKELY. GUSTY SOUTH WINDS.
* TUESDAY...CHANCE OF RAIN. IFR POSSIBLE. SOUTHWEST WINDS.
&&
.MARINE...
210 AM...LOW PRESSURE NEAR LAKE ONTARIO WILL MOVE EAST AND BE
ABSORBED BY LOW PRESSURE MOVING NORTH ALONG THE NEW ENGLAND COAST.
THIS LOW WILL THEN SLOWLY LIFT NORTHEAST AND DEEPEN OVER THE NEXT
FEW DAYS. A LARGE AREA OF HIGH PRESSURE EXTENDING FROM MANITOBA
INTO THE CENTRAL PLAINS WILL SLOWLY BUILD EAST ACROSS THE LAKES
REGION THURSDAY AND FRIDAY. NORTHWEST WINDS TO 30 KTS IN BETWEEN
THESE TWO SYSTEMS WILL GRADUALLY DIMINISH TONIGHT INTO THURSDAY.
AS THE HIGH DRIFTS ACROSS THE LAKES REGION...THERE WILL BE A
PERIOD OF LIGHT PERHAPS EVEN CALM WINDS FRIDAY NIGHT INTO SATURDAY
NIGHT UNTIL THE HIGH MOVES EAST SUNDAY AND SUNDAY NIGHT AND THE
FLOW TURNS BACK SOUTHERLY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN
UNTIL 10 AM WEDNESDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN
UNTIL 10 AM THURSDAY.
&&
$$
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
528 AM CST Wed Dec 17 2014
.SHORT TERM...(Today)
ISSUED AT 310 AM CST WED DEC 17 2014
A north-south oriented elongated high pressure ridge will edge
eastward toward Illinois today bringing with it a much lighter
surface pressure gradient and subsidence aloft. The result will be
wind speeds and gusts tapering off throughout the day as well as
thinning low cloud cover. Seasonably cold temperatures that arrived
after yesterday`s cold front will continue, with highs today only
around the freezing mark, just a few degrees below normal.
Although cloud cover will thin out through the day, current
indications are that the GFS and HRRR models are too aggressive in
clearing out low level moisture trapped below an inversion based
just below 900 mb. Forecast cloud cover is based more in line with
the NAM which keeps a saturated layer through the early part of
the day, slowly thinning through the afternoon. Meanwhile, periods
of high cloud cover will be arriving in the afternoon as well.
Also watching a band of snow flurries moving southward through Iowa
this morning. This looks as if it will remain west of the central IL
forecast area before the disturbance responsible for it ejects
eastward. This could move through portions of central IL later this
morning, but would be of very little consequence and is a fairly low
probability at this point.
&&
.LONG TERM...(Tonight through Tuesday)
ISSUED AT 310 AM CST WED DEC 17 2014
Upper wave currently pushing through Arizona on track to reach the
southern Plains tonight, before dampening out somewhat as it moves
across Missouri. Forecast soundings off most of the models are
showing the column moistening from the top down overnight, but very
dry air lingers just past sunrise below 800 mb. A short period of
isentropic lift on the 305K plane will move through central Illinois
Thursday morning, coinciding with the moistening of the lower
layers, resulting in a period of light snow across the southwestern
CWA during the morning. Current thinking is only a few tenths from
Rushville through Springfield to the Effingham/Flora areas. The
soundings further northeast toward Peoria and Bloomington generally
never really moisten the lower levels (except for the NAM), and will
keep those areas dry on Thursday.
Model trends for the Friday night/Saturday system continue to shift
more to the south, as the next deepening wave tracks into the lower
Mississippi Valley. Have limited the PoP`s for Friday night and
Saturday morning to areas south of I-70, where accumulations look to
be less than an inch. The ECMWF tries to draw some of the moisture
northward Saturday morning as a separate wave in the northern stream
swings into the Great Lakes region, so have kept some slight chances
during the morning across east central Illinois.
Active period setting up next week, as a broad long wave trough digs
southward through the central U.S. Some timing differences as to the
depth of this wave, with the ECMWF and parallel GFS cutting off a
low over southeast South Dakota and drifting it east, while the
operational GFS waits until mid week to cut off a broad low over the
Midwest. Both solutions yield precipitation as a storm system
organizes just to our northwest. Have continued to concentrate the
precip chances Monday night into Tuesday, mostly rain but perhaps
some snow mixed in across the far north. Will need to watch the
evolution of this closely, with the pre-holiday travel rush
beginning around this time.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
ISSUED AT 528 AM CST WED DEC 17 2014
Widespread MVFR ceilings across central Illinois this morning,
with local IFR near KBMI will gradually erode from west to east
beginning this afternoon. Expect cloud cover to become SCT015-020
west of KDEC-KBMI, continuing BKN015 to the east through tonight.
Winds WNW 8-12 kts this morning decreasing through the afternoon
and evening.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Onton
LONG TERM...Geelhart
AVIATION...Onton
AREA FORECAST DISCUSSION
NWS DES MOINES IA
603 AM CST WED DEC 17 2014
.SHORT TERM /TODAY/...
ISSUED AT 344 AM CST WED DEC 17 2014
NO SIGNIFICANT WEATHER OF CONCERN TODAY...BUT TEMPS MAY BE A TAD
PROBLEMATIC. RIGHT ENTRANCE REGION OF IA/IL JET SEGMENT AND WEAK
FORCING DRIVEN BY WRN KS SHORT WAVE AHEAD OF SWRN CONUS TROUGH
CONTINUE TO SPREAD TOKEN MID CLOUDS AND PRECIP ALOFT INTO SWRN
IA. FORCING REMAINS OF SIMILAR MAGNITUDE THROUGHOUT THE DAY...IS
MAINLY 3KM AND ABOVE...AND CONTINUES TO ADVANCE INTO SURFACE RIDGE
SO NO PRECIP IS ANTICIPATED THROUGH VALID PERIOD.
MODELS ARE HAVING SOME DIFFICULTY HANDLING CURRENT TEMP REGIME.
TEMPS HAVE COOLED BELOW SOME MODELS WHERE SKIES HAVE CLEARED. HIGH
RES MODELS ARE DOING BETTER THAN TRADITIONAL OPERATIONAL RUNS AS
HRRR...RAP AND GEM REGIONAL MODELS BETTER RESEMBLE REALITY.
QUESTION IS WHETHER TO EXTRAPOLATE THEIR SOLUTIONS INTO THE FUTURE
AS THEY VARY QUITE A BIT. RAP AND GEM REGIONAL KEEP THINGS QUITE
COOL WITH MINIMAL REBOUND WHILE HRRR IS BACK UP TOWARD MODEL
CONSENSUS BY AFTERNOON. EVEN THOUGH WINDS WILL DIMINISH SOMEWHAT
IN THE SURFACE RIDGE...STILL EXPECT SOME MIXING WITHOUT SNOW COVER
SO HAVE ONLY GONE JUST A TOUCH BELOW MODEL CONSENSUS WHICH IS NOT
DISSIMILAR TO MOS SUGGESTIONS.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 344 AM CST WED DEC 17 2014
A WEAK 500 MB TROUGH WILL PROGRESS ACROSS KANSAS AND MISSOURI ON
WEDNESDAY NIGHT AND THURSDAY...SPREADING LIGHT PRECIPITATION THAT
MAY MAKE IT INTO MAINLY SOUTHERN IOWA. HOWEVER...THERE WILL BE A
SURFACE HIGH PRESSURE RIDGE BUILD ACROSS THE STATE DURING THAT
TIME RESULTING IN LOW LEVEL DRY AIR ISSUES AS DEPICTED BY MOST
FORECAST SOUNDINGS. IT APPEARS PROBABLE THAT THERE WILL AT LEAST
BE SOME FLURRIES OR VERY LIGHT SNOW ACROSS OUR SOUTHERN
COUNTIES...BUT FURTHER NORTH PRECIPITATION IS MUCH LESS LIKELY AND
EVEN IN THE SOUTH ANY ACCUMULATIONS SHOULD BE LIGHT. HAVE
MAINTAINED CHANCE POPS LATE WEDNESDAY NIGHT AND THURSDAY MORNING
WITH SNOWFALL AMOUNTS AROUND AN INCH OR LESS AND GENERALLY LIMITED
TO I-80 SOUTHWARD. THERE IS A POSSIBILITY OF FREEZING DRIZZLE AT
TIMES IF THE CLOUD LAYER IS SUFFICIENTLY SHALLOW/WARM...HOWEVER AT
THIS TIME THAT IS AN UNLIKELY SCENARIO AND IT HAS NOT BEEN
INCLUDED IN THE FORECAST DUE TO THE LOW PROBABILITY OF
OCCURRENCE.
FROM THURSDAY NIGHT THROUGH SATURDAY THE AFOREMENTIONED SURFACE
HIGH PRESSURE RIDGE WILL REMAIN ANCHORED JUST TO OUR EAST...FROM
THE GREAT LAKES DOWN ACROSS ILLINOIS...RESULTING IN VERY LIGHT
SOUTHERLY FLOW AND LIKELY SEVERAL MORE DAYS OF LOW STRATUS CLOUDS
THAT WILL LIMIT TEMPERATURE FLUCTUATIONS. HAVE INCREASED CLOUD
COVER FORECAST AND COMPRESSED DIURNAL TEMPERATURE SPREADS
ACCORDINGLY. IT IS PROBABLE THAT THIS WILL MANIFEST AS MORE
DRY BUT CLOUDY AND DREARY WEATHER TO END THE WORK WEEK.
BY SATURDAY A LONGWAVE 500 MB TROUGH WILL BE CROSSING THE ROCKIES
AND SHAPING UP TO BE A BIG PLAYER IN OUR WEATHER FOR THE FIRST
HALF OF NEXT WEEK. THE TROUGH WILL REACH THE HIGH PLAINS AND THE
MIDWEST BY SUNDAY AND SUBSEQUENTLY DEEPEN AS IT IS REINFORCED BY A
SERIES OF SUCCESSIVE SHORTWAVE IMPULSES ENTERING THE TROUGH FROM
WESTERN CANADA. BY TUESDAY BOTH THE ECMWF AND GFS ARE NOW CARVING
OUT A MASSIVE 500 MB TROUGH ACROSS MOST OF THE CONUS...WITH A
CENTRAL CLOSED LOW SOMEWHERE OVER THE UPPER MIDWEST. FOR OUR
FORECAST AREA THIS SCENARIO WILL TRANSLATE INTO A PROLONGED PERIOD
OF PRECIPITATION CHANCES...BEGINNING SOMETIME AROUND SUNDAY OR
SUNDAY NIGHT AND PERSISTING AT INTERVALS AT LEAST THROUGH TUESDAY.
HOWEVER...PRECIPITATION TYPE WILL BE HEAVILY DEPENDENT ON THE
LOCATION OF THE UPPER AND SURFACE LOW PRESSURE CENTERS AND THEIR
ASSOCIATED THERMAL PROFILES. CURRENT LONG RANGE MODEL SOLUTIONS
SUPPORT A FAIRLY LONG PERIOD OF RAIN WITH SNOW MORE LIMITED TO
NORTHERN IOWA AND LATER IN THE EVENT...LIKELY RESULTING IN LOW
SNOWFALL AMOUNTS. HOWEVER...WITH THE SYSTEM STILL FOUR OR FIVE
DAYS AWAY AND NOT EVEN ENTERING THE RAOB NETWORK UNTIL AROUND
FRIDAY...THE SOLUTIONS ARE HARDLY STABLE AND A WIDE RANGE OF
EVENTUAL OUTCOMES IS POSSIBLE SO THE FORECAST WILL LIKELY BE
FLUCTUATING IN THE COMING DAYS. ALL INTERESTS WITH TRAVEL PLANS
AROUND CHRISTMAS SHOULD CONTINUE TO MONITOR THESE TRENDS AND HOPE
THAT TEMPERATURES STAY WARM ENOUGH FOR THE PRECIPITATION TO FALL
PREDOMINANTLY AS RAIN.
&&
.AVIATION...17/12Z
ISSUED AT 600 AM CST WED DEC 17 2014
PRIMARY CONCERN WILL BE DEPARTING STRATUS THIS MORNING. BACK EDGE
OF SUB 2KFT MVFR CIGS EXTENDS FROM KLWD-KTNU-KALO AND SHOULD EXIT
KALO MOMENTARILY AND ARE NOT INCLUDED IN THAT TAF. CIGS SHOULD
LINGER AT KOTM FOR A FEW MORE HOURS. AFTER THAT VFR CONDITIONS ARE
ANTICIPATED WITH NOTHING MORE THAN SCT-BKN MID AND HIGH CLOUDINESS
GRADUALLY INCREASING FROM THE WEST. WINDS WILL REMAIN FAIRLY
LIGHT...SLOWLY VEERING INTO THE NIGHT AND BECOMING LIGHT AND
VARIABLE EARLY THU MORNING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...SMALL
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
528 AM CST WED DEC 17 2014
.UPDATE...
ISSUED AT 524 AM CST WED DEC 17 2014
UPDATED FOR AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM CST WED DEC 17 2014
PRIMARY CONCERN FOR THE SHORT TERM PERIOD WAS LAKE EFFECT SNOWFALL
EVENT THIS MORNING AND INTO TODAY ACROSS THE SOUTH SHORE OF LAKE
SUPERIOR. OTHERWISE SEASONABLE CONDITIONS TODAY AND TOMORROW AS AN
AREA OF HIGH PRESSURE SETTLES IN ACROSS THE NORTHLAND.
EARLY THIS MORNING...OVERNIGHT RADAR RETURNS AND SURFACE
OBSERVATIONS INDICATED WIDESPREAD LIGHT SNOWFALL CONTINUED ACROSS
NORTHERN MINNESOTA. AS NEAR-SURFACE WINDS BACKED TO THE WEST LAKE
EFFECT SNOWFALL ACROSS THE SOUTH SHORE HAD TAPERED OFF...BUT AM
EXPECTING SNOW SHOWERS TO REDEVELOP TOWARDS SUNRISE THIS MORNING.
TEMPERATURES WERE HOLDING STEADY IN THE LOW TEENS ACROSS NORTHERN
MINNESOTA AND IN THE UPPER TEENS TO NEAR 20 IN NORTHWEST WISCONSIN.
WINDS WERE LIGHT OUT OF THE NORTHWEST AT 5 TO 10 KTS.
TODAY...THE WIDESPREAD LIGHT SNOW EARLY THIS MORNING WILL GRADUALLY
TAPER OFF AS WIDESPREAD SUBSIDENCE SETS IN DUE TO HIGH PRESSURE
MOVING INTO THE REGION. SKIES WILL BEGIN TO CLEAR PARTIALLY ALONG
THE INTERNATIONAL BORDER...BUT MOST LOCATIONS WILL REMAIN OVERCAST
DURING DAYLIGHT HOURS. A FEW FLURRIES WILL BE POSSIBLE IN THE LATE
AFTERNOON...BUT ACCUMULATING SNOWFALL WILL END BY MID-MORNING IN
MOST LOCATIONS. THE EXCEPTION WILL BE ALONG THE SOUTH SHORE OF LAKE
SUPERIOR WHERE LAKE EFFECT SNOW SHOWERS WILL REDEVELOP THIS
AFTERNOON AS THE LOW LEVEL WINDS BETTER ALIGN OUT OF THE NORTH. HAVE
DECREASED SNOWFALL AMOUNTS FROM PREVIOUS FORECASTS BASED ON THE
GUIDANCE AND EARLY MORNING OBSERVATIONS WHICH INDICATED LAKE EFFECT
SNOW SHOWERS HAVE TEMPORARILY DISSIPATED DUE TO BACKING OF
NEAR-SURFACE WINDS. RAP SOUNDINGS FOR THE SOUTH SHORE INDICATE THE
BEST LIFT TO BE BELOW THE DENDRITIC GROWTH ZONE...SO WHILE THERE
WILL BE FORCING AND MOISTURE...THE ALIGNMENT OF THE BEST LIFT MAY
RESULT IN LIMITED CRYSTAL GROWTH/AGGREGATION EXCEPT FOR ALONG THE
HIGHER TERRAIN WHERE MORE INTENSE SNOWFALL RATES COULD OCCUR.
DESPITE THESE RESERVATIONS FOR THE LAKE EFFECT SNOWFALL HAVE DECIDED
TO LEAVE THE CURRENT ADVISORY AND WARNING IN PLACE UNTIL WE BEGIN TO
RECEIVE SNOWFALL REPORTS THIS MORNING TO CONFIRM RADAR AND AUTOMATED
SURFACE OBSERVATIONS...BUT AM LEANING TOWARDS AN EARLY CANCELLATION
FOR THE WARNING AS ADDITIONAL AMOUNTS TODAY WILL PROBABLY ONLY BE IN
THE 1 TO 3 INCH RANGE.
HIGHS TODAY IN THE UPPER TEENS TO NEAR 20. WINDS WILL GRADUALLY VEER
TO THE NORTH/NORTHEAST AND WEAKEN TO 5 KTS OR LESS BY THE LATE
AFTERNOON.
TONIGHT...SOME CLEARING ALONG THE ARROWHEAD REGION OVERNIGHT WITH
NEAR CALM WINDS. A FEW LINGERING LIGHT SNOW SHOWERS/FLURRIES ALONG
THE SOUTH SHORE OF LAKE SUPERIOR. LOWS NEAR ZERO ALONG THE
INTERNATIONAL BORDER AND OTHER LOCATIONS WHERE SKIES MIGHT
CLEAR...ELSEWHERE IN THE LOW TEENS.
THURSDAY...INCREASING CLOUDS AS A MID-LEVEL DISTURBANCE MOVES EAST
ACROSS THE NORTHERN PLAINS AND INTO THE UPPER MIDWEST. THE 00Z HIRES
ARW DEPICTS AN AREA OF CONVERGENCE AND SNOW SHOWER DEVELOPING OVER
LAKE SUPERIOR BETWEEN TWO HARBORS AND HERBSTER...GRADUALLY DRIFTING
WEST TO BRING A FEW FLAKES TO THE NORTH SHORE BETWEEN THE TWIN PORTS
AND TWO HARBORS. DECIDED TO THROW IN A MENTION OF FLURRIES IN THIS
REGION AS WINDS APPEAR TO BE FAVORABLE FOR SUCH A DEVELOPMENT. VERY
LOW CONFIDENCE IN PREDICATION OF A MESOSCALE FEATURE LIKE THIS SO
FAR IN ADVANCE...BUT INTERESTING TO SEE THE HIGHER RESOLUTION ARW
MODEL PICK UP ON IT. HIGHS IN THE LOW TO MID 20S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 317 AM CST WED DEC 17 2014
FAIRLY QUIET WEATHER PATTERN FOR THE LATTER HALF OF THE WEEK WITH AN
EXITING RIDGE OF HIGH PRESSURE TO THE EAST AND A MILD AND DRY UPPER
TROUGH DROPPING IN FROM THE NW TO PRODUCE LOW CHANCES FOR VERY LIGHT
SNOW SHOWERS LATE FRIDAY INTO SATURDAY. THE SYNOPTIC FLOW WILL
REMAIN CYCLONIC...BUT RELATIVELY DRY THROUGH THE REST OF THE WEEKEND
PRIOR TO A RE-ENFORCING WAVE EJECTING OUT OF THE NRN ROCKIES WITH AN
ASSOCIATED SFC LOW FORMING OVER THE CENTRAL PLAINS SUN NIGHT AND
TRACKING TO THE EAST INTO THE SRN GREAT LAKES BY MON NIGHT/ TUE
MORNING. THIS SYSTEM WILL PRODUCE WIDESPREAD SNOW SHOWERS ACROSS THE
NORTHLAND LATE SUNDAY INTO EARLY NEXT WEEK...AND ALSO USHER IN A
MUCH COOLER AIR MASS GOING INTO THE MIDDLE OF THE WEEK. SNOW AMOUNTS
APPEAR TO BE RELATIVELY LIGHT AT THIS TIME.
TEMPERATURES EARLY IN THE EXTENDED PERIOD WILL BE ON THE COOL SIDE
WITH HIGHS IN THE 20S AND LOWS IN THE TEENS AND SINGLE DIGITS ABOVE
ZERO ON FRIDAY. A SLIGHT WARM UP WILL BE FELT SAT THROUGH MONDAY
WITH HIGHS IN THE 30S AND LOWS IN THE 20S. THE NEXT DROP IN
TEMPERATURES WILL BEGIN TUESDAY WITH HIGHS BACK DOWN INTO THE 20S
AND OVERNIGHT LOWS IN THE TEENS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 524 AM CST WED DEC 17 2014
MVFR CEILINGS WILL PERSIST THROUGH THE MORNING AND INTO THE
AFTERNOON WITH ONLY BRIEF BREAKS TO VFR AT TIMES. MVFR
VISIBILITIES IN SCATTERED SNOW SHOWERS ARE POSSIBLE WITH ON AND
OFF FLURRIES. WILL BEGIN TO LOSE THE MOISTURE ALOFT...BUT KEEP A
SOLID LOW LAYER OF MOISTURE/LOW CLOUDS AROUND THROUGH TONIGHT. THE
EXCEPTION WILL BE AROUND HIB AND INL...WHICH COULD CLEAR OUT...BUT
COULD SEE REDEVELOPMENT OF FOG LATE TONIGHT AND THUR MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 21 14 24 16 / 30 10 10 0
INL 17 0 20 11 / 10 0 0 0
BRD 17 12 22 14 / 10 0 0 0
HYR 21 13 25 12 / 20 10 0 0
ASX 22 15 25 12 / 60 20 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR WIZ003-004.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR WIZ002.
LS...SMALL CRAFT ADVISORY UNTIL 10 AM CST THIS MORNING FOR LSZ121-
145>148.
&&
$$
SHORT TERM...JJM
LONG TERM...BJT
AVIATION...BJT
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
449 AM MST WED DEC 17 2014
.AVIATION...
12Z TAF CYCLE
PACIFIC MOISTURE WILL CONTINUE TO STREAM OVER THE AREA DURING THE
NEXT 12 TO 24 HRS. CONDITIONS WILL DETERIORATE DURING THE MORNING
AND AFTERNOON HOURS TODAY BUT IMPROVE DURING THE OVERNIGHT. LOOK
FOR WIDESPREAD MVFR CATEGORIES ASSOCIATED WITH RAIN/SNOW. THE
HIGHER ELEVATION TERMINAL SITES SUCH AS GUP/SAF SHOULD SEE
PREDOMINATE SN WHILE OTHER SITES LIKE FMN/AEG/ABQ COULD SEE A MIX.
LOCALIZED IFR CONDITIONS EXPECTED WITH THE PRECIPITATION. AS THE
SH DIE OFF TONIGHT...SOME OF THE TERMINAL SITES COULD EXPERIENCE
REDEVELOPMENT OF LOWER CIG/VIS. THIS IS MOST LIKELY TO OCCUR AT
FMN/GUP.
50
&&
.PREV DISCUSSION...312 AM MST WED DEC 17 2014...
.SYNOPSIS...
SEVERAL UPPER LEVEL DISTURBANCES TODAY AND THURSDAY WILL BRING
MUCH NEEDED PRECIPITATION TO THE LAND OF ENCHANTMENT. MUCH OF THE
PRECIPITATION WILL FAVOR WESTERN...AND PERHAPS TO SOME
EXTENT...CENTRAL NEW MEXICO. 1 TO 3 INCH SNOW AMOUNTS WILL BE
COMMON ABOVE 6000 FEET...WITH 3 TO 5 INCHES ACROSS THE HIGHER
TERRAIN. AFTER THE LAST SYSTEM EXITS THE STATE THURSDAY NIGHT...A
MUCH QUIETER FRIDAY WILL PREVAIL...BUT TEMPERATURES WILL REMAIN
CHILLY. MODELS ARE BACKING OFF ON PRECIPITATION POTENTIAL THIS
WEEKEND AND EARLY NEXT WEEK...BUT THERE IS STILL PLENTY OF TIME
FOR THAT TO CHANGE.
&&
.DISCUSSION...
AFTER MANY DIFFERENT DEPICTIONS OF TODAYS EVENT BY THE MODELS
OVER THE LAST FEW DAYS...IT APPEARS THAT THEY HAVE FINALLY COME
INTO AGREEMENT. TWO QUICK MOVING SHORTWAVE TROUGHS WILL CROSS NM
TODAY...BOTH CURRENTLY WELL DEFINED ON WATER VAPOR IMAGERY. THE
FIRST IS ASSOCIATED WITH THE LIGHTNING ACROSS NORTHERN MEXICO THIS
MORNING...WHILE THE SECOND IS ASSOCIATED WITH THE LIGHTNING OFF
THE COAST OF CALI. SHOWERS ARE ALREADY DEVELOPING AHEAD OF THE
FIRST SYSTEM IN ARIZONA AND TO SOME EXTENT WESTERN NM. THIS SYSTEM
LOOKS TO CROSS NM THIS MORNING AND EARLY THIS AFTERNOON. MOST
OPERATIONAL MODELS SHOW THE FAVORED AREA OF PRECIPITATION ACROSS
THE NW QUARTER OF NM. TEMPS ARE COLD ENOUGH FOR SOME SNOW EVEN
ACROSS THE NW PLATEAU...THUS A GOOD CALL BY THE EVENING CREW TO
ADD ZONE 501 TO THE WINTER WX ADVY. THE SECOND DISTURBANCE WILL
COME QUICKLY AFTER THE FIRST AND CROSS NM LATE THIS AFTN AND THIS
EVE. SNOW LEVELS THIS AFTN WILL RANGE FROM 5500-6000 FEET OR SO.
WHILE THE FIRST SYSTEM MAY BRING A MORE SOLID AREA OF SNOW...THE
PRECIPITATION WITH THE SECOND SYSTEM LOOKS TO BE MORE CONVECTIVE
IN NATURE...AND MAY EVEN SEE SOME ISOLATED THUNDERSTORMS THIS
AFTERNOON. AREAS ALONG AND WEST OF THE RIO GRANDE WILL GENERALLY
BE FAVORED FOR PRECIPITATION.ONE INTERESTING NOTE...HOWEVER...IS
THAT THE HRRR HAS TRENDED BACK ON PRECIPITATION OVER THE LAST
SEVERAL RUNS...AT LEAST WITH PRECIPITATION THROUGH EARLY AFTN.
WITH ALL THAT SAID...THE WINTER WX ADVYS LOOK PRETTY GOOD...THOUGH
SNOW AMOUNTS WILL CERTAINLY BE ON THE LIGHTER SIDE OF ADVISORY
CRITERIA FOR MOST AREAS.
A THIRD SHORTWAVE WILL ARRIVE ON THURSDAY...THOUGH MOST OF THE
ENERGY ASSOCIATED WITH THIS SYSTEM WILL DIVE SOUTH OF THE CWA. SOME
LIGHT SHOWERY ACTIVITY SHOULD OCCUR ACROSS THE WEST AGAIN...BUT
AMOUNTS WILL BE MINIMAL. THE SOUTHERN TIER OF THE CWA...FROM THE
SOUTHWEST MTNS TO ROOSEVELT COUNTY...WILL HAVE THE BEST CHANCES FOR
PRECIPITATION...BUT EVEN THEN...AMOUNTS WILL BE MINIMAL. COLD TEMPS
WILL KEEP SNOW LEVELS LOW...GENERALLY AOB 5500 FEET.
AFTER THE THIRD SYSTEM SLIDES EAST THURSDAY NIGHT...FRIDAY SHOULD BE
QUIET...THOUGH STILL CHILLY. MODELS ARE SHOWING A TROUGH CROSSING NM
ON SATURDAY...BUT LITTLE MOISTURE IS ASSOCIATED WITH IT SO NOT
EXPECTING PRECIP ATTM. THEREAFTER...STRONG NORTHWEST FLOW LOOKS TO
BE THE RULE. THE ECMWF IS SHOWING A DISTURBANCE WITHIN THE FLOW MAY
CLIP NE NM ON MONDAY AND MONDAY NIGHT. THIS COMBINED WITH AN
ASSOCIATED COLD FRONT MAY RESULT IN SOME LIGHT SHOWERS ACROSS THE
NORTHEAST IF THE ECMWF IS CORRECT. OTHERWISE...DRIER CONDITIONS
LOOK TO BE THE RULE THROUGH AT LEAST MID WEEK.
34
&&
.FIRE WEATHER...
MAIN FIRE WEATHER HIGHLIGHTS INCLUDE AN UNSETTLED WEATHER PATTERN
WITH SOME CHANCES OF WETTING MOISTURE ACROSS WESTERN/CENTRAL AREAS
THROUGH THURSDAY MORNING. THE WEEKEND SYSTEM JUST LOOKS TOO DRY.
GUSTIER NW WINDS AND DECENT VENTILATION IN AREAS EXPECTED SUNDAY
THROUGH EARLY NEXT WEEK.
CURRENT RADAR TRENDS SHOW SHOWER DEVELOPMENT AND SOME ORGANIZATION
IN THE PRECIPITATION FIELD OVER ARIZONA. SNOW AND LOWER ELEVATION
RAIN SHOWERS WILL SPREAD ACROSS THE WESTERN HALF OF THE AREA THROUGH
THE DAY PERIOD WITH LINGERING IMPACTS INTO THE OVERNIGHT. OROGRAPHIC
WEST FACING SLOPES LOOK TO BE FAVORED WITH THE WETTING
PRECIPITATION. EASTERN AREAS WILL SEE SCANT PRECIPITATION RESULTS.
TEMPERATURES WILL BE COOLER THAN NORMAL WITH HIGH RH VALUES FAVORING
THE WESTERN HALF. FLOW ALOFT WILL INCREASE AND WILL COMBINE WITH
RISING MIXING HEIGHTS TO PRODUCE IMPROVING VENTILATION MOST AREAS.
THE SOUTHERN HALF WILL BE THE FOCUS FOR GOOD TO EXCELLENT RATINGS.
SURFACE WINDS WILL BE BREEZY AT TIMES ACROSS THE SOUTHERN
HALF...ESPECIALLY OVER THE MOUNTAIN RIDGES/PEAKS.
A SECONDARY PACIFIC WAVE OR TROUGH WILL SLIDE OVER THE REGION ON
THURSDAY. MODELS HAVE BEEN TAKING THE MAIN PIECE OF ENERGY
ASSOCIATED WITH THE TROUGH FURTHER SOUTH SO IMPACTS TO THE FIRE WX
AREA LOOK TO BE MINIMAL AT THIS TIME. PERHAPS SOME LOCALIZED WETTING
MOISTURE ACROSS THE FAR SOUTH. EITHER WAY...HIGH TEMPERATURES WILL
REMAIN BELOW NORMAL MOST AREAS WITH HIGHER HUMIDITY READINGS. MIXING
HEIGHTS APPEAR TO BE NEAR SEASONABLE IF NOT A LITTLE HIGHER THAN
NORMAL ALTHOUGH TRANSPORT WINDS WILL LOWER COMPARED TO TODAY/S
VALUES. THUS...VENT RATES WILL LOWER. LOOKING AT A STRIP OF FAIR
CONDITIONS BETWEEN FARMINGTON TO THE ESTANCIA VALLEY BUT WOULD ONLY
BE FAIR FOR 2 TO 4 HRS MOST LOCATIONS.
AS MENTIONED ABOVE...STORM SYSTEM FOR THE WEEKEND PERIOD LOOKS TO BE
A NON EVENT. THERE WILL BE A PACIFIC WAVE CAUGHT IN NW FLOW MOVING
OVER THE AREA SATURDAY NIGHT. STRENGTHENING NW FLOW WILL BE FOUND ON
THE BACKSIDE OF THE WAVE AND PROVIDE SOME BREEZES ON SUNDAY.
ESPECIALLY IMPACTING THE MT TAYLOR TO CLINES CORNER AREA. SURFACE
WINDS ON SATURDAY APPEAR TO BE LIGHT. VENTILATION RATES ON SATURDAY
LOOK TO BE ON THE LOWER SIDE WITH SOME FAIR TO GOOD CONDITIONS
GENERALLY LASTING A FEW HRS.
MODELS CONTINUE TO SHOW A GUSTIER NW FLOW DEVELOPING OVER THE AREA
DURING THE EARLIER HALF OF NEXT WEEK. VENTILATION RATES SHOULD
IMPROVE IN AREAS DUE TO THE HIGHER TRANSPORT WINDS BUT LOWER MIXING
HEIGHTS WILL PRESENT SOME OF THE AREA FROM GETTING INTO THE
FAIR/GOOD TO EXCELLENT READINGS. SUSPECT VENT RATE VALUES WILL
ADJUST SOME AS THE FLOW ADJUSTS. THE FLOW DOES LOOK TO BE DRIER WITH
TEMPERATURES BECOMING A BIT WARMER. THE GFS IS DRY BUT THE ECMWF IS
STILL SPITTING OUT LIGHTER PRECIPITATION AMOUNTS ACROSS THE EAST ON
TUESDAY. WOULD LIKE TO SEE ANOTHER DAY OR TWO WORTH OF CONSISTENT
MODEL RUNS BEFORE TOTALLY BUYING OFF ON THIS SCENARIO.
50
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR THE
FOLLOWING ZONES...NMZ501>508-510-511.
WINTER WEATHER ADVISORY FROM 8 AM THIS MORNING TO 11 PM MST THIS
EVENING FOR THE FOLLOWING ZONES...NMZ512>514.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
312 AM MST WED DEC 17 2014
.SYNOPSIS...
SEVERAL UPPER LEVEL DISTURBANCES TODAY AND THURSDAY WILL BRING
MUCH NEEDED PRECIPITATION TO THE LAND OF ENCHANTMENT. MUCH OF THE
PRECIPITATION WILL FAVOR WESTERN...AND PERHAPS TO SOME
EXTENT...CENTRAL NEW MEXICO. 1 TO 3 INCH SNOW AMOUNTS WILL BE
COMMON ABOVE 6000 FEET...WITH 3 TO 5 INCHES ACROSS THE HIGHER
TERRAIN. AFTER THE LAST SYSTEM EXITS THE STATE THURSDAY NIGHT...A
MUCH QUIETER FRIDAY WILL PREVAIL...BUT TEMPERATURES WILL REMAIN
CHILLY. MODELS ARE BACKING OFF ON PRECIPITATION POTENTIAL THIS
WEEKEND AND EARLY NEXT WEEK...BUT THERE IS STILL PLENTY OF TIME
FOR THAT TO CHANGE.
&&
.DISCUSSION...
AFTER MANY DIFFERENT DEPICTIONS OF TODAYS EVENT BY THE MODELS
OVER THE LAST FEW DAYS...IT APPEARS THAT THEY HAVE FINALLY COME
INTO AGREEMENT. TWO QUICK MOVING SHORTWAVE TROUGHS WILL CROSS NM
TODAY...BOTH CURRENTLY WELL DEFINED ON WATER VAPOR IMAGERY. THE
FIRST IS ASSOCIATED WITH THE LIGHTNING ACROSS NORTHERN MEXICO THIS
MORNING...WHILE THE SECOND IS ASSOCIATED WITH THE LIGHTNING OFF
THE COAST OF CALI. SHOWERS ARE ALREADY DEVELOPING AHEAD OF THE
FIRST SYSTEM IN ARIZONA AND TO SOME EXTENT WESTERN NM. THIS SYSTEM
LOOKS TO CROSS NM THIS MORNING AND EARLY THIS AFTERNOON. MOST
OPERATIONAL MODELS SHOW THE FAVORED AREA OF PRECIPITATION ACROSS
THE NW QUARTER OF NM. TEMPS ARE COLD ENOUGH FOR SOME SNOW EVEN
ACROSS THE NW PLATEAU...THUS A GOOD CALL BY THE EVENING CREW TO
ADD ZONE 501 TO THE WINTER WX ADVY. THE SECOND DISTURBANCE WILL
COME QUICKLY AFTER THE FIRST AND CROSS NM LATE THIS AFTN AND THIS
EVE. SNOW LEVELS THIS AFTN WILL RANGE FROM 5500-6000 FEET OR SO.
WHILE THE FIRST SYSTEM MAY BRING A MORE SOLID AREA OF SNOW...THE
PRECIPITATION WITH THE SECOND SYSTEM LOOKS TO BE MORE CONVECTIVE
IN NATURE...AND MAY EVEN SEE SOME ISOLATED THUNDERSTORMS THIS
AFTERNOON. AREAS ALONG AND WEST OF THE RIO GRANDE WILL GENERALLY
BE FAVORED FOR PRECIPITATION.ONE INTERESTING NOTE...HOWEVER...IS
THAT THE HRRR HAS TRENDED BACK ON PRECIPITATION OVER THE LAST
SEVERAL RUNS...AT LEAST WITH PRECIPITATION THROUGH EARLY AFTN.
WITH ALL THAT SAID...THE WINTER WX ADVYS LOOK PRETTY GOOD...THOUGH
SNOW AMOUNTS WILL CERTAINLY BE ON THE LIGHTER SIDE OF ADVISORY
CRITERIA FOR MOST AREAS.
A THIRD SHORTWAVE WILL ARRIVE ON THURSDAY...THOUGH MOST OF THE
ENERGY ASSOCIATED WITH THIS SYSTEM WILL DIVE SOUTH OF THE CWA. SOME
LIGHT SHOWERY ACTIVITY SHOULD OCCUR ACROSS THE WEST AGAIN...BUT
AMOUNTS WILL BE MINIMAL. THE SOUTHERN TIER OF THE CWA...FROM THE
SOUTHWEST MTNS TO ROOSEVELT COUNTY...WILL HAVE THE BEST CHANCES FOR
PRECIPITATION...BUT EVEN THEN...AMOUNTS WILL BE MINIMAL. COLD TEMPS
WILL KEEP SNOW LEVELS LOW...GENERALLY AOB 5500 FEET.
AFTER THE THIRD SYSTEM SLIDES EAST THURSDAY NIGHT...FRIDAY SHOULD BE
QUIET...THOUGH STILL CHILLY. MODELS ARE SHOWING A TROUGH CROSSING NM
ON SATURDAY...BUT LITTLE MOISTURE IS ASSOCIATED WITH IT SO NOT
EXPECTING PRECIP ATTM. THEREAFTER...STRONG NORTHWEST FLOW LOOKS TO
BE THE RULE. THE ECMWF IS SHOWING A DISTURBANCE WITHIN THE FLOW MAY
CLIP NE NM ON MONDAY AND MONDAY NIGHT. THIS COMBINED WITH AN
ASSOCIATED COLD FRONT MAY RESULT IN SOME LIGHT SHOWERS ACROSS THE
NORTHEAST IF THE ECMWF IS CORRECT. OTHERWISE...DRIER CONDITIONS
LOOK TO BE THE RULE THROUGH AT LEAST MID WEEK.
34
&&
.FIRE WEATHER...
MAIN FIRE WEATHER HIGHLIGHTS INCLUDE AN UNSETTLED WEATHER PATTERN
WITH SOME CHANCES OF WETTING MOISTURE ACROSS WESTERN/CENTRAL AREAS
THROUGH THURSDAY MORNING. THE WEEKEND SYSTEM JUST LOOKS TOO DRY.
GUSTIER NW WINDS AND DECENT VENTILATION IN AREAS EXPECTED SUNDAY
THROUGH EARLY NEXT WEEK.
CURRENT RADAR TRENDS SHOW SHOWER DEVELOPMENT AND SOME ORGANIZATION
IN THE PRECIPITATION FIELD OVER ARIZONA. SNOW AND LOWER ELEVATION
RAIN SHOWERS WILL SPREAD ACROSS THE WESTERN HALF OF THE AREA THROUGH
THE DAY PERIOD WITH LINGERING IMPACTS INTO THE OVERNIGHT. OROGRAPHIC
WEST FACING SLOPES LOOK TO BE FAVORED WITH THE WETTING
PRECIPITATION. EASTERN AREAS WILL SEE SCANT PRECIPITATION RESULTS.
TEMPERATURES WILL BE COOLER THAN NORMAL WITH HIGH RH VALUES FAVORING
THE WESTERN HALF. FLOW ALOFT WILL INCREASE AND WILL COMBINE WITH
RISING MIXING HEIGHTS TO PRODUCE IMPROVING VENTILATION MOST AREAS.
THE SOUTHERN HALF WILL BE THE FOCUS FOR GOOD TO EXCELLENT RATINGS.
SURFACE WINDS WILL BE BREEZY AT TIMES ACROSS THE SOUTHERN
HALF...ESPECIALLY OVER THE MOUNTAIN RIDGES/PEAKS.
A SECONDARY PACIFIC WAVE OR TROUGH WILL SLIDE OVER THE REGION ON
THURSDAY. MODELS HAVE BEEN TAKING THE MAIN PIECE OF ENERGY
ASSOCIATED WITH THE TROUGH FURTHER SOUTH SO IMPACTS TO THE FIRE WX
AREA LOOK TO BE MINIMAL AT THIS TIME. PERHAPS SOME LOCALIZED WETTING
MOISTURE ACROSS THE FAR SOUTH. EITHER WAY...HIGH TEMPERATURES WILL
REMAIN BELOW NORMAL MOST AREAS WITH HIGHER HUMIDITY READINGS. MIXING
HEIGHTS APPEAR TO BE NEAR SEASONABLE IF NOT A LITTLE HIGHER THAN
NORMAL ALTHOUGH TRANSPORT WINDS WILL LOWER COMPARED TO TODAY/S
VALUES. THUS...VENT RATES WILL LOWER. LOOKING AT A STRIP OF FAIR
CONDITIONS BETWEEN FARMINGTON TO THE ESTANCIA VALLEY BUT WOULD ONLY
BE FAIR FOR 2 TO 4 HRS MOST LOCATIONS.
AS MENTIONED ABOVE...STORM SYSTEM FOR THE WEEKEND PERIOD LOOKS TO BE
A NON EVENT. THERE WILL BE A PACIFIC WAVE CAUGHT IN NW FLOW MOVING
OVER THE AREA SATURDAY NIGHT. STRENGTHENING NW FLOW WILL BE FOUND ON
THE BACKSIDE OF THE WAVE AND PROVIDE SOME BREEZES ON SUNDAY.
ESPECIALLY IMPACTING THE MT TAYLOR TO CLINES CORNER AREA. SURFACE
WINDS ON SATURDAY APPEAR TO BE LIGHT. VENTILATION RATES ON SATURDAY
LOOK TO BE ON THE LOWER SIDE WITH SOME FAIR TO GOOD CONDITIONS
GENERALLY LASTING A FEW HRS.
MODELS CONTINUE TO SHOW A GUSTIER NW FLOW DEVELOPING OVER THE AREA
DURING THE EARLIER HALF OF NEXT WEEK. VENTILATION RATES SHOULD
IMPROVE IN AREAS DUE TO THE HIGHER TRANSPORT WINDS BUT LOWER MIXING
HEIGHTS WILL PRESENT SOME OF THE AREA FROM GETTING INTO THE
FAIR/GOOD TO EXCELLENT READINGS. SUSPECT VENT RATE VALUES WILL
ADJUST SOME AS THE FLOW ADJUSTS. THE FLOW DOES LOOK TO BE DRIER WITH
TEMPERATURES BECOMING A BIT WARMER. THE GFS IS DRY BUT THE ECMWF IS
STILL SPITTING OUT LIGHTER PRECIPITATION AMOUNTS ACROSS THE EAST ON
TUESDAY. WOULD LIKE TO SEE ANOTHER DAY OR TWO WORTH OF CONSISTENT
MODEL RUNS BEFORE TOTALLY BUYING OFF ON THIS SCENARIO.
50
&&
.AVIATION...
06Z TAF CYCLE
CIGS WILL CONTINUE TO LOWER ACROSS MOST AREAS NEAR TO WEST OF THE
CENTRAL MT CHAIN THROUGH AT LEAST THE MORN HOURS WED ALONG WITH
AREAS OF LIGHT TO OCCASIONALLY MODERATE RA AND SN. MOST OF THE
MORE SIGNIFICANT PRECIP SHOULD REMAIN NORTH OF A LINE FROM QUEMADO
TO RIO RANCHO TO SAF AND RTN. CIGS WILL LOWER TO MVFR AND
OCCASIONALLY IFR IN THIS AREA STARTING BETWEEN 10Z AND 14Z WITH A
FEW INSTANCES OF LIFR NOT OUT OF THE QUESTION IN HEAVIER SHSN. GUP
AND TO A SLIGHTLY LESSER DEGREE FMN TO BE MOST IMPACTED BY THE LOW
CIGS AND PRECIP. MARGINALLY MVFR CIGS POSS AT AEG...ABQ AND SAF
BETWEEN ABOUT 15 AND 23Z WED AND AGAIN AFTER 02Z. MVFR CIGS MAY
DEVELOP BETWEEN 11Z AND 18Z WED MORN AT ROW WITH A LOWER
CONFIDENCE OF SAME AT TCC SAME TIME PERIOD...THOUGH STILL LOOKS A
LITTLE MORE LIKELY THAT MVFR DECK WILL REMAIN EAST OR SE OF THOSE
SITES. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 42 26 42 20 / 70 40 20 5
DULCE........................... 37 21 37 14 / 70 50 20 20
CUBA............................ 37 22 36 16 / 80 60 20 20
GALLUP.......................... 39 21 39 14 / 80 40 20 5
EL MORRO........................ 36 21 35 13 / 70 50 30 10
GRANTS.......................... 41 22 40 13 / 60 40 20 10
QUEMADO......................... 38 23 34 22 / 60 40 30 20
GLENWOOD........................ 50 31 48 28 / 50 40 40 20
CHAMA........................... 36 19 35 13 / 80 60 30 30
LOS ALAMOS...................... 40 28 37 25 / 60 40 20 20
PECOS........................... 37 25 38 21 / 50 30 20 20
CERRO/QUESTA.................... 34 16 33 11 / 70 40 20 20
RED RIVER....................... 30 14 31 6 / 80 50 30 30
ANGEL FIRE...................... 35 11 34 3 / 70 40 20 20
TAOS............................ 39 19 38 14 / 60 30 20 20
MORA............................ 40 24 40 18 / 50 30 10 20
ESPANOLA........................ 43 26 42 22 / 40 30 10 10
SANTA FE........................ 39 27 38 25 / 60 40 20 10
SANTA FE AIRPORT................ 44 23 41 21 / 50 30 10 10
ALBUQUERQUE FOOTHILLS........... 46 28 43 27 / 60 30 10 10
ALBUQUERQUE HEIGHTS............. 48 29 45 28 / 50 20 10 10
ALBUQUERQUE VALLEY.............. 49 26 46 25 / 50 20 10 10
ALBUQUERQUE WEST MESA........... 47 28 45 26 / 50 20 10 10
LOS LUNAS....................... 50 22 46 21 / 50 20 10 10
RIO RANCHO...................... 47 30 45 27 / 50 30 10 10
SOCORRO......................... 52 28 47 27 / 30 20 20 20
SANDIA PARK/CEDAR CREST......... 42 26 39 24 / 60 30 10 20
TIJERAS......................... 44 28 41 24 / 60 30 10 10
MORIARTY/ESTANCIA............... 44 19 42 18 / 40 30 10 10
CLINES CORNERS.................. 41 24 39 20 / 50 20 10 20
GRAN QUIVIRA.................... 44 27 41 25 / 40 30 10 30
CARRIZOZO....................... 47 28 45 26 / 30 20 10 40
RUIDOSO......................... 43 24 44 22 / 40 20 10 50
CAPULIN......................... 42 19 40 17 / 40 20 10 20
RATON........................... 45 20 45 16 / 40 20 10 20
SPRINGER........................ 48 21 46 20 / 30 10 5 20
LAS VEGAS....................... 45 23 45 18 / 40 10 5 20
CLAYTON......................... 50 25 45 26 / 10 10 5 20
ROY............................. 48 24 46 23 / 20 10 5 20
CONCHAS......................... 54 30 50 30 / 10 5 5 20
SANTA ROSA...................... 55 32 51 29 / 20 5 5 20
TUCUMCARI....................... 57 29 51 27 / 10 0 5 20
CLOVIS.......................... 54 31 53 29 / 10 0 5 30
PORTALES........................ 55 30 54 29 / 10 0 5 30
FORT SUMNER..................... 54 31 54 30 / 10 0 5 20
ROSWELL......................... 61 31 56 32 / 5 0 5 30
PICACHO......................... 52 31 51 30 / 20 5 5 40
ELK............................. 49 30 49 28 / 30 10 10 40
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR THE
FOLLOWING ZONES...NMZ501>508-510-511.
WINTER WEATHER ADVISORY FROM 8 AM THIS MORNING TO 11 PM MST THIS
EVENING FOR THE FOLLOWING ZONES...NMZ512>514.
&&
$$
34
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1027 AM EST WED DEC 17 2014
.SYNOPSIS...
A WESTERLY FLOW OF MOIST AND SEASONABLY CHILLY AIR WILL BRING
SCATTERED RAIN SHOWERS WHICH WILL MIX WITH SNOW SHOWERS LATE
TODAY. SCATTERED SNOW SHOWERS AND FLURRIES WILL CONTINUE THROUGH
THURSDAY NIGHT WITH LIGHT SNOW ACCUMULATIONS LIKELY IN THE HIGHER
TERRAIN BETWEEN BINGHAMTON AND SYRACUSE.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED AT 1015 AM... HAVE UPDATED THE FORECAST TO INCREASE POPS
ACROSS CENTRAL NY AND FAR NORTHERN PA INTO THIS AFTERNOON AS
LATEST RADAR INDICATES THAT LIGHT RAIN SHOWERS ARE WIDESPREAD
ACROSS THE AREA LATE THIS MORNING. TEMPERATURES HAVE BEEN HOLDING
STEADY FROM THE MID 30S TO LOWER 40S AND PRECIPITATION TYPE IN OUR
AREA HAS BEEN ALL RAIN THIS MORNING. OBSERVATIONS TO THE WEST INDICATE A
CHANGE-OVER TO LIGHT SNOW AT OLE/ELZ AND BFD IN SW NY / NW PA AND
THIS TREND WILL GRADUALLY SPREAD EAST THROUGH THIS AFTERNOON WITH
SOME HIGHER ELEVATIONS IN STEUBEN COUNTY PROBABLY SEEING SNOW BY
NOON. FALLING TEMPERATURES INDICATED BY LATEST RAP FORECAST
THERMAL PROFILES SHOULD ALLOW RAIN SHOWERS TO TRANSITION TO LIGHT
SNOW SHOWERS IN MANY AREAS BY EVENING. ACCUMULATIONS THROUGH THE
DAYTIME HOURS TODAY WILL BE LITTLE TO NONE AS PRECIPITATION WILL
BE LIGHT AND SURFACE TEMPERATURES WILL REMAIN JUST ABOVE FREEZING.
PREVIOUS FORECAST IS BELOW.
AT 430 AM LOCAL RADARS SHOWED SCATTERED LIGHT RAIN SHOWERS ACROSS
WESTERN AND CENTRAL NEW YORK. TEMPERATURES RANGED FROM THE UPPER
30S TO LOWERS 40S.
SFC LOW PRES JUST NORTH OF LAKE ONTARIO WILL TRACK ALONG THE SAINT
LAWRENCE VALLEY AND WEAKEN AS A SECONDARY LOW ALONG COASTAL NEW
ENGLAND TRACKS ALONG THE COAST AND GRADUALLY INTENSIFIES. AN
ELONGATED UPPER LEVEL LOW OVER THE UPPER GREAT LAKES WILL MOVE
EAST TO THE VCNTY BY LATE TODAY. A MOIST WESTERLY FLOW WILL RESIDE
OVER THE REGION TODAY ALONG WITH WEAK COLD AIR ADVECTION.
SCATTERED RAIN SHOWERS WILL CONTINUE WHICH WILL GRADUALLY MIX WITH
SNOW SHOWERS LATER THIS AFTERNOON AS THE BOUNDARY LAYER COOLS.
THIS AFTERNOON AS REGION RESIDES ON THE BACK SIDE OF SFC FEATURES
WITH UPPER LEVEL LOW IN THE VCNTY, DEEP SYNOPTIC MOISTURE ALONG
WITH INSTABILITY WILL LEAD TO GREATER AREAL COVERAGE OF SHOWERY
ACTIVITY. BY AFTERNOON WILL INCREASE POPS TO LIKELY ACROSS THE NRN
CWA WITH HIGH CHC REST OF CENTRAL NY AND JUST SLIGHT CHC FAR SE.
MAX TEMPS WILL OCCUR LATER THIS MORNING THEN SLOWLY FALL DURING THE
AFTERNOON HOURS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
TONIGHT THROUGH THURSDAY NIGHT, UPPER LEVEL LOW WILL TRACK FROM
NYS TO NOVA SCOTIA WITH SYSTEM VERTICALLY STACKED BY THURSDAY
AFTERNOON. THESE FEATURES WILL KEEP A COOL AND MOIST NORTHWEST
FLOW ACROSS THE REGION WITH A CONTINUATION OF SCATTERED SNOW
SHOWERS AND FLURRIES. T85 NEVER DROPS ENOUGH FOR A SIGNIFICANT
CONTRIBUTION FORM LAKE ONTARIO ALTHOUGH SOME LAKE ENHANCEMENT IS
LIKELY SOUTHWEST OF LAKE ONTARIO PRIMARILY LATE TONIGHT AND
THURSDAY. THE HIGHER ELEVATIONS ACROSS ONONDAGA, ONEIDA, MADISON,
CORTLAND AND CHENANGO COUNTIES COULD SEE AROUND 2 INCHES. BY
THURSDAY NIGHT THE DEEP SYNOPTIC MOISTURE DECREASES ALONG WITH A
LOWERING INVERSION THEREFORE THE AREAL COVERAGE AND THREAT FOR
ACCUMULATING SNOW WILL DIMINISH.
LOWS TONIGHT WILL RANGE IN THE MID 20S TO LOWER 30S WITH MAXES
ON THURSDAY IN THE LOWER TO MIDDLE 30S. LOWS THURSDAY NIGHT IN THE
20S.
FRIDAY/FRIDAY NIGHT, SFC HIGH PRES WILL BUILD EAST FROM THE UPPER
GREAT LAKES BUT MODEL SOUNDINGS SHOW LOW LEVEL MOISTURE TRAPPED
UNDER A SUBSIDENCE. CONDITIONS WILL BE MAINLY DRY BUT SKIES WILL
MOST LIKELY REMAIN MOSTLY CLOUDY WITH IMPROVEMENT TO PARTY CLOUDY
FRIDAY NIGHT. HIGH FRIDAY WILL RANGE FROM THE UPPER 20S TO MID 30S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
330 AM UPDATE..
NORTHERN STREAM WAVE BRINGS A PERIOD OF LIGHT SNOW TO THE AREA
SATURDAY NIGHT INTO SUNDAY. BOTH THE GFS AND EURO STILL KEEP THE
COASTAL SYSTEM WELL OFF THE COAST THROUGH SUNDAY NIGHT, TO HAVE
ANY IMPACT ON OUR AREA. FOLLOWED WPC GUIDANCE MONDAY BY KEEPING
OUR AREA DRY. BOTH THE GFS AND EURO HINT AT SOME MOISTURE MOVING
UP THE COAST DURING THIS TIME SO THIS WILL HAVE TO BE WATCHED.
NEXT SYSTEM WILL BE A WARM ONE, WITH THE INITIAL TRACK TO OUR
WEST THROUGH THE OHIO VALLEY. WE WILL BE WARM ENOUGH FOR RAIN
TUESDAY THROUGH CHRISTMAS EVE DAY. EVENTUALLY ENOUGH COLD AIR
ADVECTS INTO THE AREA ON A SOUTHWEST FLOW THAT WE MAY MIX WITH OR
CHANGE TO SNOW VERY LATE CHRISTMAS EVE. PLENTY OF TIME TO WATCH
THIS ONE PLAY OUT.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
MVFR CIGS THROUGH THE END OF THE TAF PERIOD, WITH MVFR VSBYS
POSSIBLE TODAY IN SHOWERS.
DENSE FOG HAS LIFTED ACROSS THE TERMINALS AND WITH IT, THE HIGHER
THREAT FOR IFR CIGS. AT KBGM SOME IFR STILL CAN`T BE RULED OUT
THROUGH 13Z IN LIGHT FOG, BUT NOT THE 1/4 SM FOG WE HAVE HAD
RECENTLY. BEST SHOT AT SHOWERS TODAY WILL COME THIS AFTERNOON. AS
TEMPERATURES COOL A GRADUAL TRANSITION TO LIGHT SNOW IS POSSIBLE
AFTER 21Z. FOR NOW DUE TO THE EXPECTED SCATTERED NATURE OF THE
SNOW, I KEPT VSBYS IN MVFR. IF SNOW DOES MATERIALIZE, BRIEF PERIODS
OF IFR VSBSY ARE POSSIBLE THIS EVENING AND TONIGHT ESPECIALLY
NORTHERN NY TERMINALS.
WINDS TODAY VEERING INTO THE WEST-SOUTHWEST LATE THIS MORNING, AND
WEST NORTHWEST THIS AFTERNOON. SPEEDS 5 TO 10 KTS, BUT INCREASING
TO 10-15 BY LATE MORNING. WEST NORTHWEST WINDS TONIGHT AROUND 10
KTS.
OUTLOOK...
THUR TO FRI... MAINLY VFR. MVFR/IFR RESTRICTIONS ARE PSBL AT
KRME/KSYR/KITH/KBGM DUE TO CIGS AND AT TIMES WITH -SHSN.
FRI NGT TO SAT...VFR.
SAT NGT AND SUN...MVFR/IFR IN LIGHT SNOW.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RRM
NEAR TERM...MSE/RRM
SHORT TERM...RRM
LONG TERM...HEDEN
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
947 AM CST WED DEC 17 2014
.UPDATE...
ISSUED AT 943 AM CST WED DEC 17 2014
MINIMAL CHANGES MADE TO THE FORECAST AS UPPER LEVEL TROUGH AND
ASSOCIATED 7000FT CLOUD DECK SWING SOUTH ACROSS NW MN TODAY. SFC
HIGH PRESSURE WILL KEEP SKIES CLEAR IN THE VALLEY AND WEST WITH
TEMPS ADJUSTED SLIGHTLY UPWARD AS GUIDANCE HAS BEEN COOL WITH LACK
OF SNOW COVER.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 309 AM CST WED DEC 17 2014
TEMPERATURES WILL BE THE MAIN ISSUE FOR THE SHORT TERM.
THE UPPER LOW OVER THE GREAT LAKES WILL PULL FURTHER AWAY FROM THE
PLAINS TODAY...WITH SOME SLIGHTLY HIGHER HEIGHTS MOVING IN BEHIND.
SFC HIGH PRESSURE WILL CONTINUE TO EXTEND FROM CANADA INTO THE
CWA. CLOUDS CONTINUE OVER OUR EASTERN COUNTIES AND WILL HAVE TO
WATCH IF THEY PUSH FURTHER WEST. THINK THAT MORE CLOUDS WILL MOVE
INTO THE VALLEY TOWARDS SUNRISE BUT THINK THAT THEY SHOULD BE
SHORT LIVED AS THE RAP HAS RH VALUES DECREASING A BIT AS WE HEAD
INTO THE DAY. KEPT EAST OF THE RED RIVER IN THE MOSTLY CLOUDY
RANGE. TEMPS THIS MORNING IN THE WEST HAVE DROPPED BELOW ZERO
UNDER CLEAR SKIES...BUT THINK THERE SHOULD BE ENOUGH SUN TO GET
BACK INTO THE TEENS FOR HIGHS.
TONIGHT...A WEAK SHORTWAVE WILL MOVE INTO THE WESTERN DAKOTAS...BUT
NOT MUCH MOISTURE WITH IT ACCORDING TO THE MODELS. THE SFC HIGH
WILL START TO MOVE EAST IN RESPONSE...WITH SOUTHERLY WINDS
RETURNING. AT THIS POINT THINK THE WESTERN COUNTIES WILL AGAIN SEE
CLEAR SKIES BUT SOME MIXING FROM WINDS WILL KEEP TEMPS ABOVE ZERO
WHILE THE EAST WILL HAVE CLOUDS AND BE NEAR 10 DEGREES. THE
SOUTHERLY WINDS WILL PICK UP ON THURSDAY AND THERE SHOULD BE SOME
INCREASING CLOUDS THROUGHOUT THE DAY AS MOISTURE RETURN PICKS UP.
THERE WILL ALSO BE SOME WARM AIR ADVECTION SO TEMPS SHOULD BE ABLE
TO RETURN TO THE 20S.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 309 AM CST WED DEC 17 2014
THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE WEAK UPPER TROUGH
CONTINUES TO MAKE ITS WAY ACROSS THE NORTHERN PLAINS. THE
SOUTHERLY WINDS AND WARM AIR ADVECTION WILL CONTINUE...WITH THE
MODELS SHOWING SOME ISENTROPIC LIFT MOVING IN LATE THURSDAY NIGHT
AND INTO FRIDAY. CONDENSATION PRESSURE DEFICITS ARE NOT OVERLY
HIGH AND LIFT IS PRETTY WEAK. MODELS ALL PUT OUT VERY MINIMAL QPF
BUT SOME LIGHT SNOW IS NOT OUT OF THE QUESTION. KEPT SOME LOW POPS
GOING FRIDAY...BUT ANY ACCUMULATIONS WILL BE MINIMAL. TEMPS WILL
CONTINUE TO MODERATE WITH LOWS IN THE TEENS AND HIGHS ON FRIDAY
IN THE 20S.
FOR SATURDAY THROUGH TUESDAY...WEATHER OVER THE AREA IS EXPECTED
TO REMAIN FAIRLY TRANQUIL AS MOST OF THE JET ENERGY STAYS TO THE
SOUTH. SOUTHWESTERLY FLOW AT THE SFC BEHIND THE SFC RIDGE AND
INCREASING THICKNESS VALUES INDICATE A SLOW WARMING TREND...WITH
TEMPS REMAINING ABOVE NORMAL. NEXT CHANCE FOR PCPN WILL BE ON
MONDAY AS A WEAK PACIFIC WAVE CROSSES THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 638 AM CST WED DEC 17 2014
IFR CIGS AND A FEW FLURRIES CONTINUE AT KBJI WITH THE REST OF THE
CWA SEEING CLEAR SKIES. THINK THAT KBJI SHOULD RECOVER TO MVFR BY
MID MORNING AND THEN SCATTER OUT IN THE AFTERNOON. VFR CONDITIONS
WILL REMAIN OVER THE REST OF THE CWA WITH LIGHT AND VARIABLE
WINDS. WINDS WILL SETTLE DOWN OUT OF THE SOUTHEAST BY LATE IN THE
PERIOD BUT WILL STILL BE WELL BELOW 10 KTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JK
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...JR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
847 AM CST WED DEC 17 2014
.UPDATE...
ISSUED AT 838 AM CST WED DEC 17 2014
BROAD AREA OF CLOUD COVER CONTINUES OVER THE WEST HALF OF THE
STATE AND HAS BEEN TRYING TO BUILD A LITTLE TO THE EAST THIS
MORNING. FOR MORNING UPDATE HAVE ADJUSTED THE EASTERN EDGE A BIT
WITH CURRENT TRENDS. MODELS DIFFER A BIT ON WHETHER THE CLOUD
COVER WILL RETREAT SOME LATER TODAY...BUT FOR NOW WILL GO WITH
CONSISTENCY SINCE THIS HAS NOT BUDGED MUCH FOR THE PAST DAY.
UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 657 AM CST WED DEC 17 2014
CURRENT FORECAST LOOKS ON TRACK...NO CHANGES MADE. BLENDED IN
CURRENT OBSERVATIONS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 302 AM CST WED DEC 17 2014
THE CHALLENGE TODAY IS SIMILAR TO TUESDAY WITH FORECASTING THE
MOVEMENT OF A DISTINCT/SHARP DELINEATION OF CLOUDS/NO
CLOUDS...ALIGNED FAIRLY CLOSE TO AND ALONG HIGHWAY 83 THIS
MORNING. A SOLID OVERCAST WITH ISOLATED FLURRIES DOMINATE ALONG
AND TO THE WEST OF THIS LINE...WITH MOSTLY CLEAR CONDITIONS
EXTENDING EAST OF THIS LINE. TEMPERATURES DEPENDENT ON THE
MOVEMENT OF THIS LINE TODAY/TONIGHT. IN ADDITION...THE APPROACH OF
SHORTWAVE TROUGH ALOFT AND A WARM FRONT INTO EASTERN MONTANA THIS
EVENING/WEDNESDAY NIGHT WILL RESULT IN ISENTROPIC LIFT AND A
SLIGHT CHANCE OF VERY LIGHT SNOW IN THE SOUTHWEST.
THE LATEST FOG/STRATUS IMAGERY LOOP REMAINS NEARLY UNCHANGED IN
THE LAST 6 HOURS WITH THE STRATUS LINE NUDGING A BIT FARTHER
EAST...NOW INTO MINOT AND LINTON AGAIN. THE HRRR/RAP13/NAM/GFS
925MB RH TREND SHOWS NEARLY A STATIONARY SITUATION WITH THE STRATUS
DECK DURING THE DAY...FOLLOWED BY A GRADUAL PUSH EAST WEDNESDAY
EVENING AND WEDNESDAY NIGHT. THE LATEST HRRR ALSO HAS PATCHY FOG
DEVELOPING ACROSS THE SOUTHWEST AS THE STRATUS DECK CONTINUES TO
LOWER THIS MORNING. THIS SEEMS REASONABLE AND HAVE ADDED THIS INTO THE
FORECAST THROUGH 18Z. AS MENTIONED ABOVE...ISENTROPIC LIFT PER NAM
285K PRESSURE SURFACE ACROSS THE SOUTHWEST LATER THIS AFTERNOON
INTO TONIGHT WILL BE ENOUGH FOR A SIGHT CHC MENTION OF LIGHT
SNOW...ALTHOUGH EXPECTING LIMITED AMOUNTS WITH LIQUID EQUIVALENCIES
OF BETWEEN ONE AND TWO HUNDREDTHS OF AN INCH. OTHERWISE CLOUDS
REMAIN IN-TACT THROUGH THE SHORT TERM PERIOD WEST WITH ISOLATED
FLURRIES...AND MOSTLY SUNNY EAST CENTRAL. HIGHS TODAY WILL RANGE
FROM LOWER TO MID TEENS FROM THE TURTLE MOUNTAINS SOUTH TO THE
JAMES RIVER VALLEY...TO THE LOWER 20S SOUTHWEST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 302 AM CST WED DEC 17 2014
A QUIET START TO THE EXTENDED FORECAST TRANSITIONING INTO A
POTENTIALLY MORE ACTIVE PATTERN EARLY TO MID NEXT WEEK HIGHLIGHTS
THE LONG TERM.
THE 00 UTC GUIDANCE SUITE IS IN AGREEMENT ON SPLIT FLOW ACROSS THE
CENTRAL CONUS THURSDAY INTO SATURDAY...FAVORING HIGHS SLIGHTLY
ABOVE NORMAL IN THE MID 20S TO MID 30S AND DRY CONDITIONS.
THEREAFTER...ENERGY COMING ON SHORE TO THE PACIFIC NORTHWEST THIS
WEEKEND IS FORECAST TO PROPAGATE INTO THE CENTRAL CONUS LATE
SUNDAY INTO TUESDAY. THIS WOULD LEAD TO AN AMPLIFICATION OF THE
UPPER LEVEL PATTERN WITH A DEEPENING CENTRAL CONUS TROUGH. THIS
WILL HAVE TO BE MONITORED FOR POTENTIAL WINTER WEATHER CHRISTMAS
TRAVEL IMPACTS NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 302 AM CST WED DEC 17 2014
WIDESPREAD/SOLID MVFR CIGS AT KISN/KBIS NEXT 24HR. IFR CIGS AND AT
KDIK THROUGH 01Z THURSDAY...AND POSSIBLE PATCHY FOG AT THE TERMINAL
THROUGH 18Z. A VCFG HAS BEEN INCLUDED AT KDIK. KMOT HAS BEEN
WOBBLING ON THE EDGE OF THE STRATUS LINE...AND IT APPEARS KMOT WILL
JUST BARELY REMAIN WITHIN THE MVFR STRATUS DECK. KJMS WILL CONTINUE
WITH VFR CIGS/MOSTLY CLEAR SKY UNTIL 03Z THURSDAY...FOLLOWED BY
MVFR/IFR CIGS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...KS
LONG TERM...AYD
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
657 AM CST WED DEC 17 2014
.UPDATE...
ISSUED AT 657 AM CST WED DEC 17 2014
CURRENT FORECAST LOOKS ON TRACK...NO CHANGES MADE. BLENDED IN
CURRENT OBSERVATIONS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 302 AM CST WED DEC 17 2014
THE CHALLENGE TODAY IS SIMILAR TO TUESDAY WITH FORECASTING THE
MOVEMENT OF A DISTINCT/SHARP DELINEATION OF CLOUDS/NO
CLOUDS...ALIGNED FAIRLY CLOSE TO AND ALONG HIGHWAY 83 THIS
MORNING. A SOLID OVERCAST WITH ISOLATED FLURRIES DOMINATE ALONG
AND TO THE WEST OF THIS LINE...WITH MOSTLY CLEAR CONDITIONS
EXTENDING EAST OF THIS LINE. TEMPERATURES DEPENDENT ON THE
MOVEMENT OF THIS LINE TODAY/TONIGHT. IN ADDITION...THE APPROACH OF
SHORTWAVE TROUGH ALOFT AND A WARM FRONT INTO EASTERN MONTANA THIS
EVENING/WEDNESDAY NIGHT WILL RESULT IN ISENTROPIC LIFT AND A
SLIGHT CHANCE OF VERY LIGHT SNOW IN THE SOUTHWEST.
THE LATEST FOG/STRATUS IMAGERY LOOP REMAINS NEARLY UNCHANGED IN
THE LAST 6 HOURS WITH THE STRATUS LINE NUDGING A BIT FARTHER
EAST...NOW INTO MINOT AND LINTON AGAIN. THE HRRR/RAP13/NAM/GFS
925MB RH TREND SHOWS NEARLY A STATIONARY SITUATION WITH THE STRATUS
DECK DURING THE DAY...FOLLOWED BY A GRADUAL PUSH EAST WEDNESDAY
EVENING AND WEDNESDAY NIGHT. THE LATEST HRRR ALSO HAS PATCHY FOG
DEVELOPING ACROSS THE SOUTHWEST AS THE STRATUS DECK CONTINUES TO
LOWER THIS MORNING. THIS SEEMS REASONABLE AND HAVE ADDED THIS INTO THE
FORECAST THROUGH 18Z. AS MENTIONED ABOVE...ISENTROPIC LIFT PER NAM
285K PRESSURE SURFACE ACROSS THE SOUTHWEST LATER THIS AFTERNOON
INTO TONIGHT WILL BE ENOUGH FOR A SIGHT CHC MENTION OF LIGHT
SNOW...ALTHOUGH EXPECTING LIMITED AMOUNTS WITH LIQUID EQUIVALENCIES
OF BETWEEN ONE AND TWO HUNDREDTHS OF AN INCH. OTHERWISE CLOUDS
REMAIN IN-TACT THROUGH THE SHORT TERM PERIOD WEST WITH ISOLATED
FLURRIES...AND MOSTLY SUNNY EAST CENTRAL. HIGHS TODAY WILL RANGE
FROM LOWER TO MID TEENS FROM THE TURTLE MOUNTAINS SOUTH TO THE
JAMES RIVER VALLEY...TO THE LOWER 20S SOUTHWEST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 302 AM CST WED DEC 17 2014
A QUIET START TO THE EXTENDED FORECAST TRANSITIONING INTO A
POTENTIALLY MORE ACTIVE PATTERN EARLY TO MID NEXT WEEK HIGHLIGHTS
THE LONG TERM.
THE 00 UTC GUIDANCE SUITE IS IN AGREEMENT ON SPLIT FLOW ACROSS THE
CENTRAL CONUS THURSDAY INTO SATURDAY...FAVORING HIGHS SLIGHTLY
ABOVE NORMAL IN THE MID 20S TO MID 30S AND DRY CONDITIONS.
THEREAFTER...ENERGY COMING ON SHORE TO THE PACIFIC NORTHWEST THIS
WEEKEND IS FORECAST TO PROPAGATE INTO THE CENTRAL CONUS LATE
SUNDAY INTO TUESDAY. THIS WOULD LEAD TO AN AMPLIFICATION OF THE
UPPER LEVEL PATTERN WITH A DEEPENING CENTRAL CONUS TROUGH. THIS
WILL HAVE TO BE MONITORED FOR POTENTIAL WINTER WEATHER CHRISTMAS
TRAVEL IMPACTS NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 302 AM CST WED DEC 17 2014
WIDESPREAD/SOLID MVFR CIGS AT KISN/KBIS NEXT 24HR. IFR CIGS AND AT
KDIK THROUGH 01Z THURSDAY...AND POSSIBLE PATCHY FOG AT THE TERMINAL
THROUGH 18Z. A VCFG HAS BEEN INCLUDED AT KDIK. KMOT HAS BEEN
WOBBLING ON THE EDGE OF THE STRATUS LINE...AND IT APPEARS KMOT WILL
JUST BARELY REMAIN WITHIN THE MVFR STRATUS DECK. KJMS WILL CONTINUE
WITH VFR CIGS/MOSTLY CLEAR SKY UNTIL 03Z THURSDAY...FOLLOWED BY
MVFR/IFR CIGS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AC
SHORT TERM...KS
LONG TERM...AYD
AVIATION...KS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
638 AM CST WED DEC 17 2014
.UPDATE...
ISSUED AT 638 AM CST WED DEC 17 2014
ADJUSTED CLOUD COVER...AS THE EDGE OF THE STRATUS HAS STAYED
FURTHER EAST. THE RAP AND NAM BOTH HAVE THE HIGHER 925 TO 850 RH
VALUES MOVING WEST INTO THE VALLEY THIS MORNING...BUT DECREASE
THAT SATURATION. WILL KEEP MOST OF THE CLOUDS IN THE EAST ALONG
WITH A FLURRY MENTION IN THE KBJI MENTION FOR THE NEXT FEW HOURS.
THE WEST SHOULD STAY MOSTLY CLEAR.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 309 AM CST WED DEC 17 2014
TEMPERATURES WILL BE THE MAIN ISSUE FOR THE SHORT TERM.
THE UPPER LOW OVER THE GREAT LAKES WILL PULL FURTHER AWAY FROM THE
PLAINS TODAY...WITH SOME SLIGHTLY HIGHER HEIGHTS MOVING IN BEHIND.
SFC HIGH PRESSURE WILL CONTINUE TO EXTEND FROM CANADA INTO THE
CWA. CLOUDS CONTINUE OVER OUR EASTERN COUNTIES AND WILL HAVE TO
WATCH IF THEY PUSH FURTHER WEST. THINK THAT MORE CLOUDS WILL MOVE
INTO THE VALLEY TOWARDS SUNRISE BUT THINK THAT THEY SHOULD BE
SHORT LIVED AS THE RAP HAS RH VALUES DECREASING A BIT AS WE HEAD
INTO THE DAY. KEPT EAST OF THE RED RIVER IN THE MOSTLY CLOUDY
RANGE. TEMPS THIS MORNING IN THE WEST HAVE DROPPED BELOW ZERO
UNDER CLEAR SKIES...BUT THINK THERE SHOULD BE ENOUGH SUN TO GET
BACK INTO THE TEENS FOR HIGHS.
TONIGHT...A WEAK SHORTWAVE WIL MOVE INTO THE WESTERN DAKOTAS...BUT
NOT MUCH MOISTURE WITH IT ACCORDING TO THE MODELS. THE SFC HIGH
WILL START TO MOVE EAST IN RESPONSE...WITH SOUTHERLY WINDS
RETURNING. AT THIS POINT THINK THE WESTERN COUNTIES WILL AGAIN SEE
CLEAR SKIES BUT SOME MIXING FROM WINDS WILL KEEP TEMPS ABOVE ZERO
WHILE THE EAST WILL HAVE CLOUDS AND BE NEAR 10 DEGREES. THE
SOUTHERLY WINDS WILL PICK UP ON THURSDAY AND THERE SHOULD BE SOME
INCREASING CLOUDS THROUGHOUT THE DAY AS MOISTURE RETURN PICKS UP.
THERE WILL ALSO BE SOME WARM AIR ADVECTION SO TEMPS SHOULD BE ABLE
TO RETURN TO THE 20S.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 309 AM CST WED DEC 17 2014
THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE WEAK UPPER TROUGH
CONTINUES TO MAKE ITS WAY ACROSS THE NORTHERN PLAINS. THE
SOUTHERLY WINDS AND WARM AIR ADVECTION WILL CONTINUE...WITH THE
MODELS SHOWING SOME ISENTROPIC LIFT MOVING IN LATE THURSDAY NIGHT
AND INTO FRIDAY. CONDENSATION PRESSURE DEFICITS ARE NOT OVERLY
HIGH AND LIFT IS PRETTY WEAK. MODELS ALL PUT OUT VERY MINIMAL QPF
BUT SOME LIGHT SNOW IS NOT OUT OF THE QUESTION. KEPT SOME LOW POPS
GOING FRIDAY...BUT ANY ACCUMULATIONS WILL BE MINIMAL. TEMPS WILL
CONTINUE TO MODERATE WITH LOWS IN THE TEENS AND HIGHS ON FRIDAY
IN THE 20S.
FOR SATURDAY THROUGH TUESDAY...WEATHER OVER THE AREA IS EXPECTED
TO REMAIN FAIRLY TRANQUIL AS MOST OF THE JET ENERGY STAYS TO THE
SOUTH. SOUTHWESTERLY FLOW AT THE SFC BEHIND THE SFC RIDGE AND
INCREASING THICKNESS VALUES INDICATE A SLOW WARMING TREND...WITH
TEMPS REMAINING ABOVE NORMAL. NEXT CHANCE FOR PCPN WILL BE ON
MONDAY AS A WEAK PACIFIC WAVE CROSSES THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 638 AM CST WED DEC 17 2014
IFR CIGS AND A FEW FLURRIES CONTINUE AT KBJI WITH THE REST OF THE
CWA SEEING CLEAR SKIES. THINK THAT KBJI SHOULD RECOVER TO MVFR BY
MID MORNING AND THEN SCATTER OUT IN THE AFTERNOON. VFR CONDITIONS
WILL REMAIN OVER THE REST OF THE CWA WITH LIGHT AND VARIABLE
WINDS. WINDS WILL SETTLE DOWN OUT OF THE SOUTHEAST BY LATE IN THE
PERIOD BUT WILL STILL BE WELL BELOW 10 KTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...JR
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
958 AM EST WED DEC 17 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD INTO THE REGION THROUGH TONIGHT BUT
ABUNDANT MOISTURE TRAPPED IN THE LOWER LEVELS OF THE ATMOSPHERE
WILL RESULT IN A CONTINUATION OF CLOUDY SKIES. A WEAK UPPER LEVEL
DISTURBANCE COULD LEAD TO A FEW FLURRIES THURSDAY AFTERNOON INTO
THURSDAY NIGHT. A BETTER CHANCE OF RAIN AND SNOW WILL MOVE INTO
THE REGION ON SATURDAY AS A LOW PRESSURE SYSTEM MOVES THROUGH THE
TENNESSEE VALLEY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PATCHY -DZ/-FZDZ/-SN HAS PRETTY MUCH ENDED ACROSS OUR REGION THIS
MORNING AS SHALLOW STEEP LOW LEVEL LAPSE RATES AND SLIGHTLY DEEPER
MOISTURE UP TO 850 MB IS CONTINUE TO EXIT EAST. LOW STRATOCUMULUS
DECK STRETCHES BACK TO THE MS RIVER VALLEY. WITH THE SHALLOW
MOISTURE TRAPPED UNDERNEATH A SUBSIDENCE INVERSION...THERE DOES
NOT APPEAR MUCH HOPE OF SEEING ANY CLOUD EROSION IN OUR AREA. WILL
CONTINUE WITH CLOUDY SKIES THROUGH THE DAY. TEMPERATURES WILL NOT
WARM MUCH FROM CURRENT MID MORNING READINGS. HIGHS SHOULD RANGE
FROM THE LOWER 30S NW TO PERHAPS THE MID/UPPER 30S FAR SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
BASED ON THE UPSTREAM CLOUD COVER AND CONTINUED CYCLONIC
FLOW...SEE NO REASON TO STRAY FROM THE MUCH MORE CLOUDY NAM
SOLUTION THAT KEEPS ABUNDANT LOW LEVEL MOISTURE IN PLACE TONIGHT
INTO THURSDAY. THE LOW LEVELS WILL BEGIN TO DRY OUT THURSDAY AFTERNOON
INTO THURSDAY NIGHT AS A WEAKENING MID LEVEL SHORTWAVE MOVES OUT
OF THE MID MISSISSIPPI VALLEY. FORCING IS PRETTY WEAK BY THE TIME
IT MAKES IT INTO OUR AREA AND WITH ONLY SOME LIMITED
MOISTURE...THINK WE MAY JUST SEE A FEW FLURRIES WITH THIS.
BOUNDARY LAYER TEMPERATURES APPEAR WARM ENOUGH ACROSS THE FAR
SOUTH THURSDAY AFTERNOON TO ALLOW FOR A FEW SPRINKLES TO MIX IN
WITH ANY FLURRY ACTIVITY. EXPECT HIGHS ON THURSDAY RANGING FROM THE
LOWER 30S NORTH TO MID 30S SOUTH...INCREASING INTO THE MID TO
UPPER 30S BY FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE AND DRY CONDITIONS WILL START OUT THE LONG TERM
PERIOD. THE NEXT SYSTEM WILL BEGIN TO APPROACH THE AREA LATE FRIDAY
NIGHT AND INTO THE DAY ON SATURDAY BEFORE TAPERING OFF SATURDAY
NIGHT. PRECIPITATION WILL GENERALLY BE IN THE FORM OF LIGHT SNOW
ACROSS THE NW HALF OF THE FA. PRECIPITATION IS EXPECTED TO START
OFF AS SNOW ACROSS THE SE HALF OF THE FA HOWEVER SOME RAIN IS
EXPECTED TO MIX IN DURING THE DAY BEFORE TRANSITIONING BACK TO LIGHT
SNOW.
HIGH PRESSURE WILL THEN WORK BACK INTO THE AREA FOR SUNDAY AND
MONDAY. THE NEXT SYSTEM WILL BEGIN TO WORK INTO THE AREA FOR
TUESDAY. MODELS WERE IN SOMEWHAT DECENT AGREEMENT WITH THIS FEATURE
HOWEVER THE 12Z ECMWF SOLUTION IS NOW SLOWER AND MORE ROBUST. DID
NOT WANT TO JUMP ON THIS NEW SOLUTION QUITE YET AND WENT WITH MORE
OF A MODEL BLEND FOR TUESDAY. A MIX OF RAIN AND SNOW ARE EXPECTED
HOWEVER AS COLDER AIR BEGINS TO MOVE INTO THE AREA PRECIPITATION
LOOKS TO CHANGE OVER TO ALL SNOW SHOWERS DURING THE TUESDAY NIGHT
INTO WEDNESDAY TIME PERIOD.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
MVFR LOW CLOUDS WILL PREVAIL THROUGH THE TAF PERIOD. THERE
CONTINUES TO BE SIGNIFICANT DISCREPANCIES IN GUIDANCE CONCERNING
CLOUDS POTENTIALLY CLEARING EARLY THIS AFTERNOON. BUT BASED ON
WHAT HAS BEEN OCCURRING UPSTREAM FROM SURFACE OBSERVATIONS AND
SATELLITE IMAGERY HAVE OPTED TO KEEP FORECAST PESSIMISTIC AND GO
WITH THE NAM AND RAP SOLUTIONS. THERE IS A POSSIBILITY FOR A BRIEF
PERIOD OF IFR CONDS EARLY IN THE TAF PERIOD ASSOCIATE WITH VSBYS
IN SNOW SHOWERS. THESE SNOW SHOWERS CONTINUE TO DEVELOP IN
RESPONSE TO THE LOW LEVEL CONVERGENCE ASSOCIATED WITH THE CYCLONIC
FLOW OVER THE AREA AND SHOULD MOVE TO THE EAST OF THE TERMINAL BY
LATE MORNING/EARLY AFTERNOON.
AS THE CYCLONIC FLOW OVER THE AREA WEAKEN DURING THE DAY WEST
WINDS WILL SLOWLY DECREASE THROUGH TODAY AND TONIGHT SINCE THE INFLUENCE
OF THE LOW WILL BE SLOW TO MOVE AWAY FROM THE FORECAST AREA.
OUTLOOK...MVFR CEILINGS EARLY THURSDAY MORNING. MVFR CEILINGS AND
VISIBILITIES POSSIBLE FRIDAY NIGHT INTO SATURDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JGL
NEAR TERM...HICKMAN
SHORT TERM...JGL
LONG TERM...NOVAK
AVIATION...HAYDU
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
654 AM EST WED DEC 17 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD INTO THE REGION THROUGH TONIGHT BUT
ABUNDANT MOISTURE TRAPPED IN THE LOWER LEVELS OF THE ATMOSPHERE
WILL RESULT IN A CONTINUATION OF CLOUDY SKIES. A WEAK UPPER LEVEL
DISTURBANCE COULD LEAD TO A FEW FLURRIES THURSDAY AFTERNOON INTO
THURSDAY NIGHT. A BETTER CHANCE OF RAIN AND SNOW WILL MOVE INTO
THE REGION ON SATURDAY AS A LOW PRESSURE SYSTEM MOVES THROUGH THE
TENNESSEE VALLEY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SOME SLIGHTLY DEEPER MOISTURE IS RESULTING IN SOME LINGERING RAIN
AND SNOW SHOWERS ACROSS EASTERN PORTIONS OF OUR FA EARLY THIS
MORNING. MEANWHILE...PCPN HAS TRANSITIONED TO MORE OF A DRIZZLE OR
FLURRY ACROSS WESTERN PORTIONS OF OUR FA. THE LATEST RAP DOES
ALLOW FOR THE SURFACE TO 2 KM LAYER TO CONTINUE TO DRY OUT FROM
WEST TO EAST ACROSS THE AREA THROUGH MID MORNING. THIS SHOULD
ALLOW FOR THE DRIZZLE/FLURRY ACTIVITY TO GRADUALLY TAPER OFF FROM
THE WEST. IN THE LOW LEVEL CAA PATTERN...TEMPERATURES HAVE BEEN
STEADILY FALLING THIS MORNING WITH READINGS NOW AT OR A BIT BELOW
FREEZING ACROSS OUR NORTHWEST. AS A RESULT...THERE COULD BE SOME
AREAS OF FREEZING DRIZZLE THIS MORNING BEFORE THE PCPN TAPERS
OFF...ESPECIALLY ACROSS OUR NORTHERN AREAS. WITH THE WARM
TEMPERATURES OF THE PAST FEW DAYS...ROAD SURFACES ARE STILL
RUNNING SEVERAL DEGREES ABOVE FREEZING. THAT BEING SAID..ELEVATED
SURFACES AND UNTREATED BRIDGES/OVERPASSES COULD SEE A LIGHT ICE
ACCUMULATION AND WILL GO AHEAD AND COVER THE THREAT WITH AN SPS.
OTHERWISE...EXPECT CLOUDY SKIES TO CONTINUE THROUGH THE REST OF
THE AFTERNOON IN CONTINUED CYCLONIC LOW LEVEL FLOW. THE
COMBINATION OF CLOUDS AND CAA WILL RESULT IN FAIRLY STEADY TEMPS
TODAY IN THE LOW TO MID 30S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
BASED ON THE UPSTREAM CLOUD COVER AND CONTINUED CYCLONIC
FLOW...SEE NO REASON TO STRAY FROM THE MUCH MORE CLOUDY NAM
SOLUTION THAT KEEPS ABUNDANT LOW LEVEL MOISTURE IN PLACE TONIGHT
INTO THURSDAY. THE LOW LEVELS WILL BEGIN TO DRY OUT THURSDAY AFTERNOON
INTO THURSDAY NIGHT AS A WEAKENING MID LEVEL SHORTWAVE MOVES OUT
OF THE MID MISSISSIPPI VALLEY. FORCING IS PRETTY WEAK BY THE TIME
IT MAKES IT INTO OUR AREA AND WITH ONLY SOME LIMITED
MOISTURE...THINK WE MAY JUST SEE A FEW FLURRIES WITH THIS.
BOUNDARY LAYER TEMPERATURES APPEAR WARM ENOUGH ACROSS THE FAR
SOUTH THURSDAY AFTERNOON TO ALLOW FOR A FEW SPRINKLES TO MIX IN
WITH ANY FLURRY ACTIVITY. EXPECT HIGHS ON THURSDAY RANGING FROM THE
LOWER 30S NORTH TO MID 30S SOUTH...INCREASING INTO THE MID TO
UPPER 30S BY FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE AND DRY CONDITIONS WILL START OUT THE LONG TERM
PERIOD. THE NEXT SYSTEM WILL BEGIN TO APPROACH THE AREA LATE FRIDAY
NIGHT AND INTO THE DAY ON SATURDAY BEFORE TAPERING OFF SATURDAY
NIGHT. PRECIPITATION WILL GENERALLY BE IN THE FORM OF LIGHT SNOW
ACROSS THE NW HALF OF THE FA. PRECIPITATION IS EXPECTED TO START
OFF AS SNOW ACROSS THE SE HALF OF THE FA HOWEVER SOME RAIN IS
EXPECTED TO MIX IN DURING THE DAY BEFORE TRANSITIONING BACK TO LIGHT
SNOW.
HIGH PRESSURE WILL THEN WORK BACK INTO THE AREA FOR SUNDAY AND
MONDAY. THE NEXT SYSTEM WILL BEGIN TO WORK INTO THE AREA FOR
TUESDAY. MODELS WERE IN SOMEWHAT DECENT AGREEMENT WITH THIS FEATURE
HOWEVER THE 12Z ECMWF SOLUTION IS NOW SLOWER AND MORE ROBUST. DID
NOT WANT TO JUMP ON THIS NEW SOLUTION QUITE YET AND WENT WITH MORE
OF A MODEL BLEND FOR TUESDAY. A MIX OF RAIN AND SNOW ARE EXPECTED
HOWEVER AS COLDER AIR BEGINS TO MOVE INTO THE AREA PRECIPITATION
LOOKS TO CHANGE OVER TO ALL SNOW SHOWERS DURING THE TUESDAY NIGHT
INTO WEDNESDAY TIME PERIOD.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
MVFR LOW CLOUDS WILL PREVAIL THROUGH THE TAF PERIOD. THERE
CONTINUES TO BE SIGNIFICANT DISCREPANCIES IN GUIDANCE CONCERNING
CLOUDS POTENTIALLY CLEARING EARLY THIS AFTERNOON. BUT BASED ON
WHAT HAS BEEN OCCURRING UPSTREAM FROM SURFACE OBSERVATIONS AND
SATELLITE IMAGERY HAVE OPTED TO KEEP FORECAST PESSIMISTIC AND GO
WITH THE NAM AND RAP SOLUTIONS. THERE IS A POSSIBILITY FOR A BRIEF
PERIOD OF IFR CONDS EARLY IN THE TAF PERIOD ASSOCIATE WITH VSBYS
IN SNOW SHOWERS. THESE SNOW SHOWERS CONTINUE TO DEVELOP IN
RESPONSE TO THE LOW LEVEL CONVERGENCE ASSOCIATED WITH THE CYCLONIC
FLOW OVER THE AREA AND SHOULD MOVE TO THE EAST OF THE TERMINAL BY
LATE MORNING/EARLY AFTERNOON.
AS THE CYCLONIC FLOW OVER THE AREA WEAKEN DURING THE DAY WEST
WINDS WILL SLOWLY DECREASE THROUGH TODAY AND TONIGHT SINCE THE INFLUENCE
OF THE LOW WILL BE SLOW TO MOVE AWAY FROM THE FORECAST AREA.
OUTLOOK...MVFR CEILINGS EARLY THURSDAY MORNING. MVFR CEILINGS AND
VISIBILITIES POSSIBLE FRIDAY NIGHT INTO SATURDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JGL
NEAR TERM...JGL
SHORT TERM...JGL
LONG TERM...NOVAK
AVIATION...HAYDU
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
536 AM EST WED DEC 17 2014
.SYNOPSIS...
LOW LEVEL MOISTURE THROUGH THURSDAY NIGHT. HIGH PRESSURE FRIDAY.
LOW PRESSURE SYSTEM FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
LOWERED THE TEMPERATURES TODAY A COUPLE DEGREES ACROSS THE BOARD.
NO CHANGES OTHERWISE.
PREVIOUS DISCUSSION...
LOOKS LIKE WE WILL BE REVERTING TO A SIMILAR SET UP FROM LATE
LAST WEEK WITH TRAPPED MOISTURE IN THE BOUNDARY LAYER UNDER
ANOTHER MASSIVE INVERSION WITH AROUND 60-90MB DEPTH. THIS IS THE
BIGGEST CHANGE TO THE FORECAST WITH GOING 100 SKY COVER ACROSS THE
BOARD THROUGH 12Z THURSDAY. FOLLOWING THE HRRR BRINGS THE CHANCES
FOR MEASURABLE PRECIPITATION TO AN END BY 00Z TONIGHT. CARRY
DRIZZLE/FREEZING DRIZZLE UNTIL 18Z TODAY AND WILL NEED TO MONITOR
THIS TO SEE IF THIS NEEDS TO GO LONGER IN THE FORECAST.
COLD AIR ADVECTION CONTINUING INTO THE OVERNIGHT BRINGS TEMPERATURES
BACK DOWN BELOW FREEZING AREA WIDE. WIND STAYING UP SHOULD KEEP ANY
POTENTIAL FOR FREEZING FOG AT BAY.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
BEFORE THE ADVERTISED STORM SYSTEM FOR THIS WEEKEND...OF WHICH
LITTLE HAS CHANGED IN THAT FORECAST...THE PATTERN ALOFT WILL BE
ZONAL WITH A SERIES OF WEAK UPPER DISTURBANCES MOVING ACROSS THE
AREA. THESE WILL KEEP CONSIDERABLE CLOUDINESS THURSDAY AND
FRIDAY...BUT NO PRECIP ADDED AS MOISTURE IS LIMITED AND THE
DISTURBANCES WILL BE WEAKENING AS THEY MOVE ACROSS. TEMPERATURES WILL
BE NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ACTIVE WEATHER IN THE LONG TERM PERIOD. PERIOD STARTS OUT WITH A
SPLIT UPPER FLOW PATTERN ACROSS THE U.S...WITH A LOW PRESSURE SYSTEM
IN THE SOUTHERN STREAM MOVING EAST ACROSS THE SOUTHEASTERN UNITED
STATES FRIDAY NIGHT INTO SATURDAY...WITH A SHORTWAVE TROUGH IN THE
NORTHERN STREAM PUSHING EAST ACROSS THE OHIO VALLEY...BRINGING A
REINFORCING SHOT OF COLD AIR INTO THE REGION. MODELS ARE STARTING TO
COME INTO BETTER AGREEMENT WITH THE TRACK OF THE LOW...BUT ECMWF IS
DEEPER...AND MORE PROGRESSIVE WITH NORTHERN STREAM SHORTWAVE...THUS
RESULTING IN A COLDER SOLUTION. DEPENDING ON WHICH SOLUN PANS
OUT...COULD SEE MORE OF A WINTRY MIX...AS WITH THE GFS SOLUN...OR A
MAINLY SNOW...WITH POSSIBLY BRIEF RAIN/SNOW MIX ACROSS
LOWLANDS...WITH THE ECMWF SOLUN. HAVE TRENDED THE FORECAST TOWARDS
HPC...WHICH TENDS TO FAVOR WARMER SOLUN. THUS...EXPECTING A WINTRY
MIX TO DEVELOP ACROSS THE AREA FRIDAY NIGHT/SATURDAY...BEFORE
TRANSITIONING TO MAINLY RAIN ACROSS THE LOWLANDS SATURDAY...THEN
BACK TO SNOW OR A MIX SATURDAY NIGHT. ITS POSSIBLE WINTER WEATHER
HEADLINES MAY BE NEEDED DURING THIS PERIOD.
HIGH PRESSURE WILL BUILD IN BEHIND THE SYSTEM FOR EARLY NEXT
WEEK...FOR A BRIEF BREAK IN THE PRECIPITATION...BEFORE ANOTHER
SYSTEM MOVES IN TOWARDS MID WEEK.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
TEETERING ON THE MVFR/IFR CEILING THRESHOLD FOR A FEW HOURS THIS
MORNING WHICH WILL TAKE AWAY FROM THE CONFIDENCE IN THIS ISSUANCE
JUST A TOUCH. LOW LEVEL MOISTURE SOCKED INTO PLACE FOR THE TAF
PERIOD UNDER A STRONG DEVELOPING INVERSION ABOVE THE BOUNDARY
LAYER. AS A RESULT...RESTRICTIONS THROUGH THE PERIOD EXPECTED WITH
LOW CEILINGS IN PLACE. WINDS WILL KEEP ANY VISIBILITY ISSUES FROM
OCCURRING THROUGH 12Z THURSDAY. SOME MIXING TODAY COULD BUMP THE
CEILINGS UP OVER 2KFT FOR A PERIOD THIS AFTERNOON ALONG THE OHIO
RIVER.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: IFR MAY NOT DEVELOP AROUND DAWN. MAY SEE
BRIEF VFR AT PKB AND HTS THIS AFTERNOON.
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.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY H M M M M H H H M M M M
HTS CONSISTENCY H H M M M H H H M M M M
BKW CONSISTENCY M M H H H H H M M M M M
EKN CONSISTENCY L L H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H M M M
CKB CONSISTENCY H H H M M H H H H H H H
AFTER 12Z THURSDAY...
IFR POSSIBLE IN WINTRY MIX SATURDAY INTO SUNDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...26
SHORT TERM...JMV
LONG TERM...SL
AVIATION...26
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
936 AM EST WED DEC 17 2014
.SYNOPSIS...
HIGH PRESSURE WILL SPREAD BACK OVER THE REGION TODAY BEHIND A
DEPARTING COLD FRONT. A WEAK WEATHER SYSTEM ALOFT WILL SPREAD CLOUDS
AND PERHAPS SOME SPOTTY LIGHT SHOWERS IN THE MOUNTAINS ON THURSDAY.
ANOTHER LOW WILL DEVELOP TO OUR SOUTHWEST ON FRIDAY AND INCREASE
CHANCES FOR WIDESPREAD PRECIPITATION GOING INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
930 AM EST UPDATE...HAVE DECREASED THE CLOUD COVER OVER PORTIONS OF
THE NC MTNS/VALLEYS PER LATEST VISBY SATELLITE IMAGERY TREND.
OTHERWISE...CURRENT FORECAST REMAINS ON TRACK.
AS OF 600 AM EST WEDNESDAY...LATEST RADAR TRENDS REMAIN RATHER
UNIMPRESSIVE REGARDING POSSIBLE LIGHT SHRA ACROSS THE NORTHERN
MTNS. THUS POP FCST WILL REMAIN AS IS WHICH FEATURES ALL POPS BEING
REMOVED WITH THE HOUR. LOW LEVEL STRATUS ACROSS THE MTNS IS STILL
FCST TO SCATTER THROUGH MORNING. MADE SLIGHT TWEAKS TO TEMPERATURES
AND DEWPOINTS TO REFLECT LATEST OBSERVATIONS.
PREVIOUS DISCUSSION...
AS OF 300 AM EST WEDNESDAY...QUASI ZONAL UPPER FLOW MIGRATING OVER
THE SOUTHEAST WHILE CANADIAN HIGH PRESSURE DIVES SOUTHWARD THROUGH
THE MS RIVER VALLEY INTO THE OH/TN VALLEYS. MODEST WEST/NORTHWEST
850MB FLOW ALONG THE CENTRAL APPS CONTINUES TO YIELD SCATTERED
SHOWERS ACROSS PORTIONS OF EASTERN KY NORTHWARD INTO WEST VIRGINIA.
ALTHOUGH AMPLE MOISTURE REMAINS FURTHER SOUTH ACROSS PORTIONS OF
WESTERN NC...WEAKER FLOW CONTINUES TO LIMIT COVERAGE. LATEST
NAM/GFS REMAIN PERSISTENT IN SUGGESTING INCREASING SHOWER COVERAGE
ALONG THE TN LINE NORTH OF INTERSTATE 40 THROUGH MID MORNING.
HOWEVER...HIGH RES GUIDANCE SUCH AS THE HRRR CONTINUES TO BACK OFF.
ALL SAID...WILL KEEP LOW END SLIGHT CHANCE POPS FOR ISOLATED SHOWERS
ACROSS THE NORTHERN MTNS THROUGH 12Z. FCST DOES FEATURE BRIEF
PERIOD OF FZRA FOR THESE ZONES AS MODEST INVERSION ALOFT SUGGESTS
PRECIP WILL FALL AS LIQUID WITH SOME FREEZING POSSIBLE TOWARD
MORNING LOWS. NOT EXPECTING ANY SIGNIFICANT IMPACTS BUT CANNOT RULE
OUT A FEW PATCHES OF BLACK ICE.
BEYOND THAT...HIGH PRESSURE WILL PREVAIL ACROSS THE REGION WITH
MOSTLY SUNNY SKIES DOMINATING OVER THE LOW TERRAIN. DID KEEP
MENTION OF MOSTLY/PARTLY CLOUDY SKIES ACROSS THE HIGH TERRAIN AS
WEAK WESTERLY UPSLOPE FLOW CONTINUES AMONGST SHALLOW MOIST LAYER.
MEANWHILE ANOTHER WEAK UPPER IMPULSE WILL BE SLIDING THROUGH THE
SOUTHERN PLAINS ALLOWING SOME HIGH LEVEL CIRRUS TO MOVE OVER THE
FCST AREA THIS AFTERNOON THROUGH PERIODS END. DOWNSLOPING FLOW WILL
YIELD NORMAL LEVEL HIGH TEMPERATURES ACROSS THE FOOTHILLS/PIEDMONT
REGIONS WHILE SLIGHTLY BELOW NORMAL HIGHS ARE FCST OVER THE MTNS.
LOWS TONIGHT WILL BE NEAR NORMAL AS ABOVE MENTIONED INCREASING HIGH
LEVEL CIRRUS LIMITS RADIATIONAL COOLING.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 325 AM WEDNESDAY...A WEAK SHORT WAVE WILL MOVE THRU THE ZONAL
FLOW ALOFT THU. THERE IS VERY LITTLE DEEP MOISTURE OR FORCING WITH
THIS SYSTEM. CANNOT RULE OUT A FEW SPRINKLES ACROSS THE NC MTNS
WHERE WLY FLOW MAY BE ABLE TO SQUEEZE THEM OUT OF THE MOISTURE.
THERE SHUD BE QUITE A BIT OF CLOUDS ACROSS THE AREA HOWEVER. SHORT
WAVE RIDGING DEVELOPS AHEAD OF THE NEXT WX SYSTEM APPROACHING FROM
THE SW ON FRI. THIS WILL BRING AN INCREASE IN CLOUDS THRU THE DAY
AFTER THE THU NITE CLEARING FROM THE DEPARTING SHORT WAVE. HIGHS
WILL BE NEAR NORMAL BOTH DAYS...WHILE LOWS THU NITE WILL BE A FEW
DEGREES ABOVE NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 355 AM WEDNESDAY...GUIDANCE REMAINS IN GOOD AGREEMENT ON THE
OVERALL PATTERN FOR THE WEEKEND STORM SYSTEM...BUT SOME DIFFERENCES
REMAIN REGARDING THE TEMPERATURE PROFILE AND RESULTING P-TYPES. A
SHORT WAVE APPROACHES THE AREA FRI NITE...MOVES ACROSS THE AREA SAT
AND EAST ON SAT NITE. AT THE SFC...A LOW PRESSURE SYSTEM MOVES EAST
ALONG THE GULF COAST WHILE HIGH PRESSURE SETS UP OVER THE AREA IN A
COLD AIR DAMMING CONFIGURATION. PRECIP CHC INCREASES FROM THE SW FRI
NITE AS MOISTURE MOVES IN AHEAD OF THIS SYSTEM...CAT POP DEVELOPS
ALL AREAS SAT AS THE LOW MOVES SOUTH OF THE AREA...WITH POP SLOWLY
TAPERING OFF SAT NITE AND ENDING ON SUN. THE GFS IS WARMER THAN THE
ECMWF...BUT THE ECMWF IS NOT VERY COLD. USING A BLEND OF THESE TWO
MDLS FOR TEMPS AND THICKNESSES RESULTS IN COLDEST TEMPS AND
THICKNESSES ALONG THE NRN TIER OF THE CWFA...POSSIBLY EXTENDING
SOUTH ALONG THE BLUE RIDGE TO THE SC BORDER. EVEN THEN...P-TYPE
SEEMS TO FAVOR A WINTRY MIX FOR THE NRN BLUE RIDGE AND FREEZING RAIN
EAST AND SOUTH OF THERE. RAIN IS THE P-TYPE FOR MOST OF THE CWFA.
CANNOT RULE OUT ADVISORY LEVEL ICE ACCUMS FOR THE NRN MTN LOCATIONS
LATE FRI NITE AND SAT MORN. HAVE GONE WITH RAIN OR SNOW AS PRECIP
COMES TO AN END SAT NITE AND SUN MORN...BUT THIS AND ANY POTENTIAL
ACCUMS ARE MUCH MORE UNCERTAIN. LOWS WILL BE ABOVE NORMAL FRI AND
SAT NITES...WITH HIGHS SAT 10 DEGREES BELOW NORMAL...RISING TO A FEW
DEGREES BELOW NORMAL ON SUN.
GUIDANCE BEGINS TO DIVERGE FOR THE REST OF THE MEDIUM RANGE. A DEEP
TROF DEVELOPS ACROSS THE CENTRAL CONUS...BUT THE ECMWF IS SLOWER AND
DEEPER WITH THE TROF THAN THE GFS. THE GFS ALSO BRINGS SOME WEAK
SHORT WAVE ENERGY ACROSS THE AREA AHEAD OF THE TROF ON MON...WHILE
THE ECMWF DAMPENS THE WAVE SIGNIFICANTLY. AT THE SFC...THE GFS HAS A
WELL DEFINED LOW PRESSURE SYSTEM WELL SOUTH OF THE AREA ACROSS
FLORIDA AND MOVES IN INTO THE ATLANTIC...KEEPING OUR CWFA RELATIVELY
DRY...WHILE THE ECMWF HAS A LESS DEFINED SFC LOW...BUT A STRONGER
BAROCLINIC ZONE CLOSER TO THE CWFA SPREADING PRECIP IN FROM THE
SOUTH. GIVEN THE DISCREPANCIES...HAVE KEPT MON BASICALLY DRY WITH
TEMPS NEAR NORMAL.
PRECIP SPREADS BACK INTO THE AREA TUE AS A FRONTAL SYSTEM ASSOCIATED
WITH THE UPPER TROF MOVES BACK INTO THE AREA FROM THE WEST.
HOWEVER...DETAILS DIFFER ON EXACT TIMING AND THERMAL STRUCTURE.
THEREFORE...HAVE CHC POP SPREADING IN FROM THE WEST TUE. AGAIN...
GIVEN THE DIFFERENCES...USED RAIN/SNOW FOR THE P-TYPE WHICH WOULD
INDICATE SOME SNOW AT ONSET ACROSS THE NC MTNS...BUT THIS IS ALSO
HIGHLY UNCERTAIN. TEMPS TUE NEAR NORMAL.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. ZONAL FLOW
ALOFT AND WEAK HIGH PRESSURE AT THE SURFACE WILL KEEP SKIES CLEAR
THROUGH MORNING WITH LIGHT NORTHERLY FLOW. MODELS CONTINUE TO HINT
AT WEAK LEE TROF DEVELOPMENT BY MID MORNING CAUSING FLOW TO BACK
NEARLY DUE WEST THROUGH THE AFTERNOON. KEPT WINDS JUST NORTH OF
WEST UNTIL 02Z WHEN CALMING PREVAILS. SKIES WILL SLOWLY FILL IN THIS
AFTERNOON IN THE MID/UPPER LEVELS AS CIRRUS STREAMS IN ALOFT FROM
UPSTREAM MOISTURE PLUME ASSOCIATED WITH WEAK UPPER WAVE.
ELSEWHERE...VERY SIMILAR TO KCLT ABOVE WITH VFR PREVAILING AT ALL
SITES. SURFACE WINDS WILL VARY ACROSS THE REGION DUE TO LEE TROF
DEVELOPMENT BY LATE MORNING. ALL SC SITES WILL BE LIGHT/CALM BEFORE
INCREASING OUT OF THE SW BY MID MORNING. AS FOR THE NC SITES...KAVL
WILL REMAIN NORTHERLY AT 8-10KTS THROUGH THE PERIOD WITH KHKY
GRADUALLY BACKING WESTERLY BY MID/LATE MORNING DUE TO ABOVE
MENTIONED LEE TROF. FLOW WILL VEER NORTHERLY AT ALL SITES LATE IN
THE DAY WITH MID/HIGH LEVEL CIRRUS STREAMING IN ALOFT LEADING TO
CIGS AT KAVL NEAR THE END OF THE TAF CYCLE.
OUTLOOK...A WEAK UPPER DISTURBANCE WILL SLIDE THROUGH THE REGION ON
THURSDAY WITH LITTLE/NO IMPACT EXPECTED. ANOTHER MORE ORGANIZED
SYSTEM WILL APPROACH FROM THE WEST FOR THE START OF THE WEEKEND ONCE
AGAIN INCREASING PRECIP/RESTRICTION CHANCES. SOME WINTRY PRECIP IS
POSSIBLE ACROSS THE NC MOUNTAINS/FOOTHILLS AFFECTING BOTH KAVL AND
KAND SATURDAY MORNING. WINTRY PRECIP IS NOT EXPECTED AT THIS TIME
FOR ANY OTHER TAF SITES.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-12Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 96% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...CDG/JOH
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...CDG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
622 AM EST WED DEC 17 2014
.SYNOPSIS...
HIGH PRESSURE WILL SPREAD BACK OVER THE REGION TODAY BEHIND A
DEPARTING COLD FRONT. A WEAK WEATHER SYSTEM ALOFT WILL SPREAD CLOUDS
AND PERHAPS SOME SPOTTY LIGHT SHOWERS IN THE MOUNTAINS ON THURSDAY.
ANOTHER LOW WILL DEVELOP TO OUR SOUTHWEST ON FRIDAY AND INCREASE
CHANCES FOR WIDESPREAD PRECIPITATION GOING INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM EST WEDNESDAY...LATEST RADAR TRENDS REMAIN RATHER
UNIMPRESSIVE REGARDING POSSIBLE LIGHT SHRA ACROSS THE NORTHERN MTNS.
THUS POP FCST WILL REMAIN AS IS WHICH FEATURES ALL POPS BEING
REMOVED WITH THE HOUR. LOW LEVEL STRATUS ACROSS THE MTNS IS STILL
FCST TO SCATTER THROUGH MORNING. MADE SLIGHT TWEAKS TO TEMPERATURES
AND DEWPOINTS TO REFLECT LATEST OBSERVATIONS.
PREVIOUS DISCUSSION...
AS OF 300 AM EST WEDNESDAY...QUASI ZONAL UPPER FLOW MIGRATING OVER
THE SOUTHEAST WHILE CANADIAN HIGH PRESSURE DIVES SOUTHWARD THROUGH
THE MS RIVER VALLEY INTO THE OH/TN VALLEYS. MODEST WEST/NORTHWEST
850MB FLOW ALONG THE CENTRAL APPS CONTINUES TO YIELD SCATTERED
SHOWERS ACROSS PORTIONS OF EASTERN KY NORTHWARD INTO WEST VIRGINIA.
ALTHOUGH AMPLE MOISTURE REMAINS FURTHER SOUTH ACROSS PORTIONS OF
WESTERN NC...WEAKER FLOW CONTINUES TO LIMIT COVERAGE. LATEST
NAM/GFS REMAIN PERSISTENT IN SUGGESTING INCREASING SHOWER COVERAGE
ALONG THE TN LINE NORTH OF INTERSTATE 40 THROUGH MID MORNING.
HOWEVER...HIGH RES GUIDANCE SUCH AS THE HRRR CONTINUES TO BACK OFF.
ALL SAID...WILL KEEP LOW END SLIGHT CHANCE POPS FOR ISOLATED SHOWERS
ACROSS THE NORTHERN MTNS THROUGH 12Z. FCST DOES FEATURE BRIEF
PERIOD OF FZRA FOR THESE ZONES AS MODEST INVERSION ALOFT SUGGESTS
PRECIP WILL FALL AS LIQUID WITH SOME FREEZING POSSIBLE TOWARD
MORNING LOWS. NOT EXPECTING ANY SIGNIFICANT IMPACTS BUT CANNOT RULE
OUT A FEW PATCHES OF BLACK ICE.
BEYOND THAT...HIGH PRESSURE WILL PREVAIL ACROSS THE REGION WITH
MOSTLY SUNNY SKIES DOMINATING OVER THE LOW TERRAIN. DID KEEP
MENTION OF MOSTLY/PARTLY CLOUDY SKIES ACROSS THE HIGH TERRAIN AS
WEAK WESTERLY UPSLOPE FLOW CONTINUES AMONGST SHALLOW MOIST LAYER.
MEANWHILE ANOTHER WEAK UPPER IMPULSE WILL BE SLIDING THROUGH THE
SOUTHERN PLAINS ALLOWING SOME HIGH LEVEL CIRRUS TO MOVE OVER THE
FCST AREA THIS AFTERNOON THROUGH PERIODS END. DOWNSLOPING FLOW WILL
YIELD NORMAL LEVEL HIGH TEMPERATURES ACROSS THE FOOTHILLS/PIEDMONT
REGIONS WHILE SLIGHTLY BELOW NORMAL HIGHS ARE FCST OVER THE MTNS.
LOWS TONIGHT WILL BE NEAR NORMAL AS ABOVE MENTIONED INCREASING HIGH
LEVEL CIRRUS LIMITS RADIATIONAL COOLING.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 325 AM WEDNESDAY...A WEAK SHORT WAVE WILL MOVE THRU THE ZONAL
FLOW ALOFT THU. THERE IS VERY LITTLE DEEP MOISTURE OR FORCING WITH
THIS SYSTEM. CANNOT RULE OUT A FEW SPRINKLES ACROSS THE NC MTNS
WHERE WLY FLOW MAY BE ABLE TO SQUEEZE THEM OUT OF THE MOISTURE.
THERE SHUD BE QUITE A BIT OF CLOUDS ACROSS THE AREA HOWEVER. SHORT
WAVE RIDGING DEVELOPS AHEAD OF THE NEXT WX SYSTEM APPROACHING FROM
THE SW ON FRI. THIS WILL BRING AN INCREASE IN CLOUDS THRU THE DAY
AFTER THE THU NITE CLEARING FROM THE DEPARTING SHORT WAVE. HIGHS
WILL BE NEAR NORMAL BOTH DAYS...WHILE LOWS THU NITE WILL BE A FEW
DEGREES ABOVE NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 355 AM WEDNESDAY...GUIDANCE REMAINS IN GOOD AGREEMENT ON THE
OVERALL PATTERN FOR THE WEEKEND STORM SYSTEM...BUT SOME DIFFERENCES
REMAIN REGARDING THE TEMPERATURE PROFILE AND RESULTING P-TYPES. A
SHORT WAVE APPROACHES THE AREA FRI NITE...MOVES ACROSS THE AREA SAT
AND EAST ON SAT NITE. AT THE SFC...A LOW PRESSURE SYSTEM MOVES EAST
ALONG THE GULF COAST WHILE HIGH PRESSURE SETS UP OVER THE AREA IN A
COLD AIR DAMMING CONFIGURATION. PRECIP CHC INCREASES FROM THE SW FRI
NITE AS MOISTURE MOVES IN AHEAD OF THIS SYSTEM...CAT POP DEVELOPS
ALL AREAS SAT AS THE LOW MOVES SOUTH OF THE AREA...WITH POP SLOWLY
TAPERING OFF SAT NITE AND ENDING ON SUN. THE GFS IS WARMER THAN THE
ECMWF...BUT THE ECMWF IS NOT VERY COLD. USING A BLEND OF THESE TWO
MDLS FOR TEMPS AND THICKNESSES RESULTS IN COLDEST TEMPS AND
THICKNESSES ALONG THE NRN TIER OF THE CWFA...POSSIBLY EXTENDING
SOUTH ALONG THE BLUE RIDGE TO THE SC BORDER. EVEN THEN...P-TYPE
SEEMS TO FAVOR A WINTRY MIX FOR THE NRN BLUE RIDGE AND FREEZING RAIN
EAST AND SOUTH OF THERE. RAIN IS THE P-TYPE FOR MOST OF THE CWFA.
CANNOT RULE OUT ADVISORY LEVEL ICE ACCUMS FOR THE NRN MTN LOCATIONS
LATE FRI NITE AND SAT MORN. HAVE GONE WITH RAIN OR SNOW AS PRECIP
COMES TO AN END SAT NITE AND SUN MORN...BUT THIS AND ANY POTENTIAL
ACCUMS ARE MUCH MORE UNCERTAIN. LOWS WILL BE ABOVE NORMAL FRI AND
SAT NITES...WITH HIGHS SAT 10 DEGREES BELOW NORMAL...RISING TO A FEW
DEGREES BELOW NORMAL ON SUN.
GUIDANCE BEGINS TO DIVERGE FOR THE REST OF THE MEDIUM RANGE. A DEEP
TROF DEVELOPS ACROSS THE CENTRAL CONUS...BUT THE ECMWF IS SLOWER AND
DEEPER WITH THE TROF THAN THE GFS. THE GFS ALSO BRINGS SOME WEAK
SHORT WAVE ENERGY ACROSS THE AREA AHEAD OF THE TROF ON MON...WHILE
THE ECMWF DAMPENS THE WAVE SIGNIFICANTLY. AT THE SFC...THE GFS HAS A
WELL DEFINED LOW PRESSURE SYSTEM WELL SOUTH OF THE AREA ACROSS
FLORIDA AND MOVES IN INTO THE ATLANTIC...KEEPING OUR CWFA RELATIVELY
DRY...WHILE THE ECMWF HAS A LESS DEFINED SFC LOW...BUT A STRONGER
BAROCLINIC ZONE CLOSER TO THE CWFA SPREADING PRECIP IN FROM THE
SOUTH. GIVEN THE DISCREPANCIES...HAVE KEPT MON BASICALLY DRY WITH
TEMPS NEAR NORMAL.
PRECIP SPREADS BACK INTO THE AREA TUE AS A FRONTAL SYSTEM ASSOCIATED
WITH THE UPPER TROF MOVES BACK INTO THE AREA FROM THE WEST.
HOWEVER...DETAILS DIFFER ON EXACT TIMING AND THERMAL STRUCTURE.
THEREFORE...HAVE CHC POP SPREADING IN FROM THE WEST TUE. AGAIN...
GIVEN THE DIFFERENCES...USED RAIN/SNOW FOR THE P-TYPE WHICH WOULD
INDICATE SOME SNOW AT ONSET ACROSS THE NC MTNS...BUT THIS IS ALSO
HIGHLY UNCERTAIN. TEMPS TUE NEAR NORMAL.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. ZONAL FLOW
ALOFT AND WEAK HIGH PRESSURE AT THE SURFACE WILL KEEP SKIES CLEAR
THROUGH MORNING WITH LIGHT NORTHERLY FLOW. MODELS CONTINUE TO HINT
AT WEAK LEE TROF DEVELOPMENT BY MID MORNING CAUSING FLOW TO BACK
NEARLY DUE WEST THROUGH THE AFTERNOON. KEPT WINDS JUST NORTH OF
WEST UNTIL 02Z WHEN CALMING PREVAILS. SKIES WILL SLOWLY FILL IN THIS
AFTERNOON IN THE MID/UPPER LEVELS AS CIRRUS STREAMS IN ALOFT FROM
UPSTREAM MOISTURE PLUME ASSOCIATED WITH WEAK UPPER WAVE.
ELSEWHERE...VERY SIMILAR TO KCLT ABOVE WITH VFR PREVAILING AT ALL
SITES. SURFACE WINDS WILL VARY ACROSS THE REGION DUE TO LEE TROF
DEVELOPMENT BY LATE MORNING. ALL SC SITES WILL BE LIGHT/CALM BEFORE
INCREASING OUT OF THE SW BY MID MORNING. AS FOR THE NC SITES...KAVL
WILL REMAIN NORTHERLY AT 8-10KTS THROUGH THE PERIOD WITH KHKY
GRADUALLY BACKING WESTERLY BY MID/LATE MORNING DUE TO ABOVE
MENTIONED LEE TROF. FLOW WILL VEER NORTHERLY AT ALL SITES LATE IN
THE DAY WITH MID/HIGH LEVEL CIRRUS STREAMING IN ALOFT LEADING TO
CIGS AT KAVL NEAR THE END OF THE TAF CYCLE.
OUTLOOK...A WEAK UPPER DISTURBANCE WILL SLIDE THROUGH THE REGION ON
THURSDAY WITH LITTLE/NO IMPACT EXPECTED. ANOTHER MORE ORGANIZED
SYSTEM WILL APPROACH FROM THE WEST FOR THE START OF THE WEEKEND ONCE
AGAIN INCREASING PRECIP/RESTRICTION CHANCES. SOME WINTRY PRECIP IS
POSSIBLE ACROSS THE NC MOUNTAINS/FOOTHILLS AFFECTING BOTH KAVL AND
KAND SATURDAY MORNING. WINTRY PRECIP IS NOT EXPECTED AT THIS TIME
FOR ANY OTHER TAF SITES.
CONFIDENCE TABLE...
11-17Z 17-23Z 23-05Z 05-06Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 80% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...CDG
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...CDG
AREA FORECAST DISCUSSION
NWS ALBANY NY
446 PM EST WED DEC 17 2014
.SYNOPSIS...
THE COMBINATION OF LOW PRESSURE STRENGTHENING OFF THE
NORTHERN NEW ENGLAND COAST...AND AN UPPER LEVEL DISTURBANCE PASSING
THROUGH OVERNIGHT WILL KEEP SKIES MOSTLY CLOUDY...ALONG WITH SOME
PASSING RAIN AND SNOW SHOWERS...MOST FREQUENT ACROSS THE SOUTHERN
ADIRONDACKS AND SOUTHERN VERMONT. THURSDAY WILL BE
BLUSTERY WITH LINGERING SNOW SHOWERS ACROSS HIGHER
ELEVATIONS...ALTHOUGH SOME BREAKS IN THE CLOUDS WILL BE POSSIBLE
SOUTH OF THE CAPITAL REGION. SLIGHTLY COLDER AIR WILL SEEP INTO
THE REGION FROM THE NORTH FOR THURSDAY NIGHT AND FRIDAY...DESPITE
THE POSSIBILITY FOR SOME BREAKS IN THE CLOUDS TO DEVELOP.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 430 PM EST...HAVE MADE SOME MINOR ADJUSTMENTS TO THE GRIDDED
DATABASE...MAINLY TO INCREASE POPS A BIT MORE FROM ALBANY NORTH
LATER TONIGHT...PARTICULARLY ACROSS THE HIGHER TERRAIN...INTO THE
LIKELY TO CATEGORICAL RANGE.
WE WILL HAVE TO WATCH RADAR TRENDS CLOSELY OVERNIGHT...AS THE
LATEST RAP13 AND HRRR SUGGEST THAT A MID LEVEL LOW CENTER
ASSOCIATED A COMPACT YET POTENT SHORTWAVE CURRENTLY PASSING OVER
SOUTHERN MICHIGAN POSSIBLY CLOSES OFF SOMEWHERE ACROSS SOUTHERN
AREAS AS IT PASSES QUICKLY EAST/SOUTHEAST. THIS MAY ALLOW FOR SOME
ADDITIONAL MID LEVEL FORCING/DEFORMATION ACROSS CENTRAL AND
NORTHERN PORTIONS OF THE REGION...MAINLY AFTER MIDNIGHT. THIS
ADDITIONAL FORCING COULD ALLOW FOR SOME BURSTS OF SNOW TO
OCCUR...INITIALLY ACROSS HIGHER ELEVATIONS...THEN EVEN ACROSS SOME
VALLEY AREAS...FROM AROUND THE CAPITAL REGION NORTH TO THE LAKE
GEORGE/SARATOGA REGION. THIS COULD ALLOW FOR HIGHER
ACCUMS...PERHAPS INTO THE 2-5 INCH RANGE FOR SOME HIGHER
ELEVATIONS OF THE ADIRONDACKS...SOUTHERN VT...AND WESTERN MA.
ALSO...MANY VALLEY AREAS BETWEEN ALBANY AND LAKE GEORGE COULD
RECEIVE A QUICK COATING...TO JUST UNDER AN INCH OF SNOW LATER TONIGHT.
PREVIOUS DISCUSSION...
OTHERWISE...THE OCCLUDED FRONT HAS PASSED EAST AND NORTH OF THE
REGION. HOWEVER...TWO SHORTWAVES...ONE CURRENTLY LOCATED ACROSS
THE CENTRAL NYS/PA BORDER...AND ANOTHER OVER THE SOUTHERN GREAT
LAKES...WILL CONTINUE TRANSLATING EASTWARD OVERNIGHT. THE FIRST
ONE WILL ALLOW SHOWERS TO PERSIST THROUGH THIS
EVENING...ESPECIALLY ACROSS HIGHER ELEVATIONS OF THE EASTERN
CATSKILLS...TACONICS...AND BERKSHIRES. SOME LIGHT RAIN SHOWERS OR
DRIZZLE WILL OCCASIONALLY REACH THE VALLEY AREAS AS WELL THROUGH
EARLY TONIGHT. CLOUD TOPS ARE RELATIVELY SHALLOW...WITH CLOUD TOP
TEMPS GENERALLY IN THE -5 TO -8 C RANGE OR SLIGHTLY WARMER.
SO...AT LEAST FOR NOW...THERE APPEARS TO BE MINIMAL ICE CRYSTALS
IN THE CLOUDS...WITH JUST PERHAPS SOME SNOW GRAINS ACROSS THE
HIGHER ELEVATIONS OVER THE NEXT 3 HOURS.
LATER THIS EVENING...THE FIRST IMPULSE WILL PASS EAST OF THE
REGION...WITH THE NEXT ONE POISED UPSTREAM. THE COMBINATION OF
ENHANCED LOW LEVEL MOISTURE FROM THE NEARBY LAKES...AND ADDITIONAL
MID LEVEL MOISTURE ROTATING SOUTHEAST TO SOUTH FROM NORTH OF THE
GREAT LAKES SHOULD ALLOW FOR SOME SEEDER FEEDER PROCESSES...IN
ADDITION TO OVERALL COOLING MID LEVEL TEMPS...TO ALLOW FOR A
TRANSITION TO MAINLY SNOW SHOWERS ACROSS HIGHER TERRAIN...WITH
RAIN SHOWERS OR DRIZZLE GRADUALLY MIXING WITH...AND POSSIBLY
CHANGING TO SNOW OR SNOW GRAINS IN SOME VALLEY AREAS AFTER
MIDNIGHT. AGAIN...OVERALL CLOUD TOP TEMPS MAY NOT BE QUITE COLD
ENOUGH FOR DENDRITIC SNOW CRYSTALS...SO SNOW CONSISTENCY MAY BE
SOMEWHAT GRAINY IN NATURE...AND NOT CONDUCIVE FOR SIGNIFICANT
ACCUMS. AT THIS TIME...IT APPEARS THAT 1-3 INCHES WILL BE POSSIBLE
ACROSS HIGHER ELEVATIONS ACROSS THE SOUTHWEST ADIRONDACKS...AS
WELL AS ACROSS HIGHER...WEST FACING ELEVATIONS ACROSS SOUTHERN VT.
SOME LOCALLY HIGHER AMTS COULD OCCUR FOR ELEVATIONS ABOVE 1800 FT.
ALSO...PORTIONS OF THE BERKSHIRES COULD GET 1-2 INCHES LATE
TONIGHT...WITH PERHAPS SLIGHTLY HIGHER AMTS FOR ELEVATIONS ABOVE
1800 FT IN EASTERN BERKSHIRE CO.
IT APPEARS THAT LOW LEVEL DIRECTIONAL WIND SHEAR WILL PREVENT TRUE
SINGLE BANDED LAKE EFFECT SNOW TO OCCUR...BUT STILL EXPECT A
COMBINATION OF SYNOPTIC...AND OROGRAPHIC EFFECTS TO PRODUCE THE
OVERNIGHT SNOW IN HIGHER ELEVATIONS.
WINDS WILL INCREASE FROM THE WEST TO NORTHWEST OVERNIGHT...WITH
SOME GUSTS POSSIBLY REACHING 25-30 MPH BY DAYBREAK...ESP IN
FAVORABLE CHANNELED W/E VALLEYS...SUCH AS THE MOHAWK RIVER
VALLEY...AS WELL AS IN THE BERKSHIRES.
THE COMBINATION OF CLOUDS...AND INCREASING WIND SHOULD PREVENT
TEMPS FROM FALLING AS LOW AS THE MAV MOS SUGGESTS...AND IN SOME
AREAS...IT IS POSSIBLE THAT TEMPS MAY ONLY DROP TO NEAR OR EVEN
SLIGHTLY ABOVE FREEZING...ESP WITHIN THE IMMEDIATE MOHAWK RIVER
VALLEY/CAPITAL REGION AND UPPER HUDSON RIVER VALLEY. HAVE
THEREFORE WENT WITH...OR ABOVE THE SLIGHTLY WARMER MET MOS FOR
OVERNIGHT MINS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
THURSDAY...AFOREMENTIONED SECOND SHORTWAVE IMPULSE SHOULD MOVE
GENERALLY EAST OF THE REGION IN THE MORNING. HOWEVER...SOME
LINGERING UPSLOPE SNOW SHOWERS WILL LIKELY PERSIST ACROSS PORTIONS
OF THE SW ADIRONDACKS...SOUTHERN VT...AND WESTERN MA. ADDITIONAL
ACCUMS OF AN INCH OR TWO COULD OCCUR WITHIN THE MORE PERSISTENT
AREAS OF SNOW SHOWERS. ELSEWHERE...THE MAIN STORY FOR THU SHOULD
BE GUSTY WINDS...WHICH MAY GUST UP TO 35 MPH OR SLIGHTLY
HIGHER...ESP IN PORTIONS OF THE MOHAWK VALLEY/CAPITAL REGION AND
BERKSHIRES. ALTHOUGH MOST AREAS NEAR AND NORTH OF INTERSTATE 90
SHOULD REMAIN MOSTLY CLOUDY TO OVERCAST...SOME BREAKS OF SUN WILL
BE MORE LIKELY TO THE SOUTH...WITH SKIES POSSIBLY BECOMING MOSTLY
SUNNY AT TIMES ACROSS PORTIONS OF THE MID HUDSON
VALLEY...LITCHFIELD CO CT...AND POSSIBLY EXTREME SE VT. IN THESE
AREAS...TEMPS COULD WARM INTO THE 40S. ELSEWHERE...EXPECT MAINLY
30S IN VALLEYS...AND UPPER 20S/LOWER 30S ACROSS HIGHER ELEVATIONS.
THU NT-FRI NT...A SURFACE TROUGH IS EXPECTED TO GRADUALLY SETTLE
SOUTHWARD LATE THU NT INTO FRI...WITH A SLIGHTLY COLDER...SHALLOW
AIR MASS IN ITS WAKE. AS THE TROUGH PASSES...IT COULD ALLOW FOR A
BRIEF RESURGENCE IN SNOW SHOWERS/FLURRIES...MAINLY ACROSS HIGHER
ELEVATIONS LATE THU NT. AS WINDS SHIFT MORE INTO THE NW TO N IN
THE WAKE OF THE TROUGH...ANY LAKE ENHANCED SNOW SHOWERS SHOULD
SHIFT INTO THE CENTRAL NYS...PERHAPS OCCASIONALLY GRAZING THE
CATSKILLS. ELSEWHERE...THE POTENTIAL FOR CLEARING SKIES WILL
INCREASE IN AT LEAST VALLEY AREAS DURING FRIDAY...WITH MAINLY
CLEAR SKIES ANTICIPATED FOR FRI NT. TEMP THU NT SHOULD FALL INTO
THE 20S IN MOST AREAS...WITH SOME TEENS POSSIBLE ACROSS THE
SOUTHERN ADIRONDACKS. FRI SHOULD BE CHILLY...WITH MAX TEMPS MAINLY
REACHING THE LOWER/MID 30S IN VALLEY AREAS...EXCEPT NEAR 40 ACROSS
THE MID HUDSON VALLEY AND SOUTHERN LITCHFIELD CO CT...WITH MAINLY
20S TO LOWER 30S EXPECTED ACROSS HIGHER ELEVATIONS. FRI NT SHOULD
BE COLDER...WITH MOST MIN TEMPS FALLING INTO THE LOWER/MID 20S IN
VALLEYS...AND TEENS ACROSS HIGHER TERRAIN.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
SATURDAY STILL LOOKS DRY WITH SEASONABLY CHILLY TEMPERATURES. AFTER
THAT...IT LOOKS AS IF WE WILL BE DEALING WITH A MAINLY WEAK SOUTHERN
STREAM DISTURBANCE...BUT THEN A POTENTIALLY MUCH STRONGER "PHASED"
SYSTEM AS HEAD TO CHRISTMAS EVE.
THE ONLY DAY THAT WE MIGHT SEE ANY SOME SUNSHINE WOULD BE
SATURDAY...OTHERWISE PLENTY OF CLOUDS WILL PERSIST. EITHER WAY LOOK
FOR HIGHS FROM THE UPPER 20S NORTHWEST TO LOOK TO MID 30S SOUTH.
BY SUNDAY...WE WILL BE DEALING WITH AN EASTERLY FLOW FROM HIGH
PRESSURE ANCHORED IN EXTREME EASTERN CANADA...AS WELL AS SOME SORT
OF WEAK WAVE DEVELOPING WELL SOUTH IN THE JETSTREAM. ALSO...THERE
MIGHT BE AN EVEN WEAKER WAVE IN THE NORTHERN BRANCH OF THE JETSTREAM
THAT MIGHT INTERACT WITH THE SOUTHERN ONE TO DEVELOP SOME SORT OF
INVERTED TROUGH LATE SUNDAY INTO MONDAY. THIS FEATURE...COMBINED
WITH AN EASTERLY FLOW...COULD TRIGGER ENOUGH LIFT TO PRODUCE WHAT
LOOKS TO BE NUISANCE TYPE PRECIPITATION...MOUNTAIN SNOW AND A VALLEY
RAIN/SNOW MIX SUNDAY INTO MONDAY. AGAIN...THIS IS NOT GOING TO BE A
BIG STORM BUT IT COULD PRODUCE SOME SLIPPERY ROADS...ESPECIALLY
SUNDAY NIGHT AND HIGHER ELEVATIONS. THE TIMING OF THIS POSSIBLE
EVENT IS STILL UNCERTAIN SO FOR NOW WE HAVE INCLUDED SLIGHT CHANCES
SATURDAY NIGHT...AND LOW CHANCES SUNDAY INTO SUNDAY NIGHT AND SLIGHT
CHANCES
MONDAY.
HIGHS SUNDAY WILL GENERALLY BE IN THE 30S...ABOVE FREEZING IN THE
VALLEYS. LOWS SUNDAY NIGHT WILL BE AROUND 30 IN MOST PLACES. HIGHS
MONDAY AGAIN IN THE 30S.
BY LATE MONDAY...THE EUROPEAN AND GFS FORECAST MODELS ARE
FORECASTING A MUCH STRONGER TROUGH ASSOCIATED WITH THE NORTHERN
BRANCH TO DIG IN THE NATION/S MID SECTION. THIS TROUGH IS FORECAST
TO INTERACT WITH SOUTHERN STREAM ENERGY TO PRODUCE WHAT COULD BE A
POWERFUL STORM AS WE HEAD INTO LATE TUESDAY AND WEDNESDAY.
THE TRACK OF THIS STORM LOOKS TO BE ALONG OR NEAR THE APPALACHIAN
MOUNTAINS...WELL TO THE WEST OF THE HUDSON VALLEY. IT WOULD IMPACT
OUR REGION MAINLY ON CHRISTMAS EVE. A STORM WITH THIS TRACK WOULD
LIKELY BRING MOSTLY RAIN...PERHAPS A LITTLE WINTRY MIX ON THE FRONT
SIDE. AS IT MOVES UP TO OUR NORTHWEST...IT WOULD PULL AIR IN COLD
ENOUGH TO PERHAPS SWITCH LEFTOVER RAIN SHOWERS INTO SNOW SHOWERS BY
CHRISTMAS EVE NIGHT.
THIS STORM MIGHT BRING SOME STRONG WIND TO THE HIGHER TERRAIN
WEDNESDAY...AS IT LOOKS SIMILAR TO THE SETUP OF THE GREAT
APPALACHIAN STORM OF 1950 AS WELL AS THE "CLEVELAND BOMB" OF 1978.
HEAVY RAIN MIGHT TRIGGER SOME HYDRO ISSUES AS WE STILL HAVE A BIT OF
SNOW TO MELT IN THE MOUNTAINS.
BEING NEARLY A WEEK AWAY A LOT OF THE SYNOPTIC SETUP COULD
CHANGE...BUT THIS STORM DEFINITELY BEARS WATCHING.
HIGHS ON WEDNESDAY LOOK TO BE MAINLY IN THE 40S...DROPPING TO BELOW
FREEZING BY LATE CHRISTMAS EVE NIGHT.
&&
.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
AN UPPER LEVEL DISTURBANCE WILL CONTINUE TO PLAGUE THE SITES
THROUGH THE EVENING PEAK...WITH VERY SLOW IMPROVING TREND TO MVFR
KGFL/KPSF/KALB EXPECTED. THIS WILL BE DUE TO SLIGHTLY DRIER AIR
ADVECTING IN THE FROM THE WEST...AND A BREEZE ALSO PICKING UP FROM
THE WEST 5-10KTS THROUGH THIS EVENING.
CIGS AT KPOU LOOK TO REACH INTO THE VFR THRESHOLD TONIGHT BUT WILL
LIKELY REMAIN MVFR OR EVEN LOW MVFR (EXTRA FUEL REQUIRED) AT KPSF.
BY THURSDAY...THE WIND WILL 10-15KTS WITH GUSTS 20-25 KTS (HIGHEST
AT KPSF AND KALB). THE WIND SHOULD HELP SCOUR CLOUDS OUT A
LITTLE...BUT STILL EXPECT CIGS...REACHING BARELY INTO THE VFR RANGE
(EXCEPT HOLDING AT HIGH MVFR AT KPSF) AFTER ABOUT 13Z THURSDAY.
SHOWERS COULD IMPACT THE TAFS MAINLY EARLY THIS AFTERNOON...SO WE
ASSIGNED A VCSH AT ALL THE TAFS EXCEPT KPOU WHERE THE THREAT WAS
LOWEST. SHOWERS COULD HELP REDUCE VISIBILITIES VERY BRIEFLY DOWN TO
LIFR AT KALB/KPSF/ AND KGFL.
OUTLOOK...
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
MONDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN.
&&
.HYDROLOGY...
NO HYDROLOGIC CONCERNS THROUGH THE REMAINDER OF THE WEEK.
ADDITIONAL LIGHT RAIN OR SNOW SHOWERS WILL CONTINUE INTO TONIGHT.
BASIN AVERAGE PRECIP AMOUNTS WILL BE LIGHT...GENERALLY LESS THAN A
QUARTER OF AN INCH. ONLY VERY MINOR RISES ARE EXPECTED ON RIVERS
AND STREAMS...WITH MOST RIVER FLOWS EXPECTED TO REMAIN FAIRLY
STEADY.
SOME ADDITIONAL LIGHT MOUNTAIN SNOW SHOWERS ARE POSSIBLE THURSDAY
INTO FRIDAY...BUT THESE VERY BE FAIRLY LIMITED AND WON/T HAVE ANY
IMPACT ON AREA WATERWAYS. TEMPERATURES LOOK TO BE A LITTLE COLDER
FOR THURS/FRI...WHICH WILL LIMIT THE AMOUNT OF SNOW MELT THAT
OCCURS. MAINLY DRY WEATHER IS EXPECTED FOR THE WEEKEND...WITH JUST
A LOW CHANCE FOR SOME LIGHT SNOW.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/KL
NEAR TERM...KL
SHORT TERM...KL
LONG TERM...HWJIV
AVIATION...HWJIV
HYDROLOGY...KL
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
415 PM CST WED DEC 17 2014
.SHORT TERM...
230 PM CST
THROUGH FRIDAY...
RELATIVELY BENIGN WEATHER ON TAP IN THE NEAR TERM UNDER THE
INFLUENCE OF HIGH PRESSURE WHICH WILL REMAIN OVER THE REGION INTO
THE WEEKEND. SURFACE RIDGE EXTENDS FROM MANITOBA INTO THE LOWER
MISSISSIPPI VALLEY THIS AFTERNOON WHILE ALOFT A SHEARED VORT MAX IS
DIGGING SOUTHEAST ACROSS FAR NORTHERN ILLINOIS. SOUNDINGS INDICATE
STEEP LOW LEVEL LAPSE RATES UP TO AROUND 900MB THIS AFTERNOON AND
RADAR IMAGERY DOES SHOW SIGNS OF SOME CONVECTIVE ROLLS WITH VERY
WEAK WIND PARALLEL RETURNS. WITH THESE INGREDIENTS IN PLACE...A FEW
FLURRIES HAVE BEEN NOTED ACROSS THE AREA...BUT NOTHING OF
CONSEQUENCE. ANY FLURRIES SHOULD TAPER BY MID-LATE AFTERNOON AS
INVERSION HEIGHTS BEGIN TO COME DOWN IN RESPONSE TO MODERATE TO
STRONG MID LEVEL HEIGHT RISES BEHIND DEPARTING SHORTWAVE. STRATUS
DECK REMAINS IN PLACE TODAY BUT HAS BEGUN TO THIN AND ERODE NEAR
THE WESTERN COUNTIES. ANY PEAKS OF SUNSHINE TODAY THOUGH ARE
EXPECTED TO BE BRIEF AS MID LEVEL CLOUD COVER INCREASES FROM THE
NORTH AS A WEAK TROUGH EMBEDDED ON THE EASTERN PERIPHERY OF THE
HIGH SAGS SOUTH ACROSS LAKE MICHIGAN...AND FROM THE SOUTHWEST AS
ANOTHER SHORTWAVE TROUGH CURRENTLY LIFTING ACROSS THE PANHANDLES
OF TX/OK PUSHES ACROSS CENTRAL ILLINOIS MIDDAY THURSDAY. PRECIP
WITH THIS SYSTEM IS EXPECTED TO STAY SOUTH OF THE CWA...TAPERING
AS IT OVERRIDES THE SURFACE RIDGE. CLOUD COVER MAY CONTINUE TO
REMAIN LOCKED IN UNDER THE INVERSION FRIDAY...BUT OTHERWISE EXPECT
VERY LIGHT WINDS AND DRY CONDITIONS ON SQUARELY UNDER THE SURFACE
HIGH.
DEUBELBEISS
&&
.LONG TERM...
230 PM CST
FRIDAY NIGHT THROUGH THURSDAY...
HIGH PRESSURE WILL CONTINUE TO SLOWLY SHIFT EAST ACROSS THE REGION
OVER THE WEEKEND WITH RETURN FLOW BRINGING WARMER TEMPERATURES
ESPECIALLY BY SUNDAY. MEANWHILE...THE PATTERN IS PROGGED TO BEGIN
AMPLIFYING BY LATE IN THE WEEKEND AS LONGWAVE TROUGH DEEPENS ACROSS
THE MID SECTION OF THE COUNTRY DOWNSTREAM OF A BUILDING RIDGE ALONG
THE WEST COAST. THE JET STREAM WILL DIVE TOWARDS THE GULF STATES BY
TUESDAY WITH SURFACE LOW DEEPENING IN RESPONSE EARLY NEXT WEEK.
THERE REMAIN SIGNIFICANT DIFFERENCES AS WELL AS RUN-TO-RUN
VARIABILITY IN THE TIMING AND TRACK OF THE LOW AS IT LIFTS ACROSS
THE MIDWEST MIDWEEK...WITH COMPLICATIONS AS THE MODELS DEAL WITH
PHASING THE SOUTHERN LOW WITH A CLIPPER LIKE SYSTEM. WILL
CERTAINLY HAVE TO KEEP AN EYE ON THE POTENTIAL FOR ACCUMULATING
SNOW TUESDAY INTO WEDNESDAY OVER THE NEXT SEVERAL DAYS AS MODELS
HOPEFULLY BEGIN TO HONE IN ON A SOLUTION. A RETURN TO BELOW NORMAL
CONDITIONS SEEMS LIKELY FOR THE LATTER HALF OF THE WEEK.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* MVFR CEILING TRENDS AND POSSIBLE SCATTERING.
* WIND TRENDS...GUSTINESS TODAY AND VARIABLE LATE TONIGHT.
LENNING
//DISCUSSION...UPDATED 18Z...
CEILINGS ARE HANGING IN THE MVFR RANGE BUT SHOWING SIGNS OF
SCATTERING OUT IN AREAS WEST OF THE ORD/MDW TERMINALS. GIVEN THE
PERSISTENCE OF THIS CLOUD SHIELD IT IS HARD TO PUSH THE CLEARING
INTO THE AREA BEFORE WE ACTUALLY SEE IT HAPPENING...SO FOR NOW
WILL MAINTAIN CURRENT TRENDS INTO THE OVERNIGHT HOURS. WINDS
REMAIN WESTERLY TO NORTHWESTERLY FOR MOST OF THE PERIOD...BUT BY
TOMORROW A WEAKENING PRESSURE GRADIENT MAY ALLOW WINDS TO GO
VARIABLE FOR A TIME...THOUGH LIKELY CONTINUE TO FAVOR A WESTERLY
COMPONENT.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM CONFIDENCE IN CEILING TRENDS.
* HIGHER CONFIDENCE IN WIND TRENDS.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT THROUGH SATURDAY...DRY/VFR. LIGHT/VRB WINDS.
* SUNDAY...DRY. MVFR POSSIBLE. SOUTH WINDS.
* MONDAY...CHANCE OF RAIN. MVFR LIKELY. GUSTY SOUTH WINDS.
* TUESDAY...CHANCE OF RAIN. IFR POSSIBLE. SOUTHWEST WINDS.
&&
.MARINE...
210 PM CST
THE LOW PRESSURE THAT PASSED THROUGH THE GREAT LAKES REGION OVER THE
PAST COUPLE DAYS IS IN THE PROCESS OF MERGING WITH ANOTHER LOW OVER
THE NEW ENGLAND COAST. THIS LOW WILL GRADUALLY DEEPEN AND SLOWLY
MOVE NORTH ALONG THE NEW ENGLAND COAST AS HIGH PRESSURE SPREADS FROM
THE NORTHERN PLAINS AND ACROSS THE WESTERN GREAT LAKES BY THURSDAY
MORNING. WINDS ARE SLOWLY SUBSIDING OVER THE LAKE...BUT A SECONDARY
TROUGH AND SURGE OF COOLER AIR MOVING DOWN THE LAKE THIS AFTERNOON
AND EVENING WILL KEEP RELATIVELY BRISK NLY-NLWY WINDS OVER THE LAKE
THROUGH THE NIGHT TONIGHT. WINDS SHOULD WEAKEN TO THE 10-15KT RANGE
THURSDAY NIGHT AND FRIDAY AS THE HIGH GRADUALLY SPREADS EAST...WHILE
MAINTAINING A NLY DIRECTION. THE HIGH WILL SPREAD ACROSS LAKE
MICHIGAN THURSDAY NIGHT AND FRIDAY...LEADING TO MORE LGT/VRBL WINDS
OVER THE LAKE. HIGH PRESSURE WILL VERY SLOWLY SPREAD EWD...BUT
STILL CONTROLLING FLOW OVER THE LAKE...KEEPING WINDS GENERALLY LIGHT
AND VARIABLE INTO THE WEEKEND. BY SUNDAY...THE HIGH WILL FINALLY
PUSH EAST OF LAKE MICHIGAN AS A TROUGH OF LOW PRESSURE DEVELOPS OVER
THE NORTHERN PLAINS. THIS WILL SET UP INCREASING SLY FLOW OVER THE
LAKE BY SUNDAY. A DEVELOPING LOW IS EXPECTED TO TRACK ACROSS THE
NRN PLAINS SUNDAY NIGHT AND MONDAY...REACHING THE MIDDLE MISSISSIPPI
VALLEY BY TUESDAY. THIS WILL KEEP GENERALLY SOUTHERLY WINDS OVER
THE LAKE THROUGH EARLY NEXT WEEK.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 10 AM THURSDAY.
&&
$$
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
247 PM CST Wed Dec 17 2014
.SHORT TERM...(Tonight)
ISSUED AT 245 PM CST WED DEC 17 2014
19z/1pm satellite imagery continues to show overcast conditions
across much of central Illinois: however, the clouds are beginning
to erode northwest of the Illinois River. While HRRR guidance has
not been particularly useful in the short-term, satellite trends
suggest skies will partially clear across all but the far E/NE KILX
CWA by early evening. After a period of mostly clear skies early
tonight, clouds will once again begin increasing in advance of the
next storm system, which is currently evident on water vapor imagery
over west Texas. Quite a bit of precip and even some thunder is
occurring ahead of this wave over Oklahoma/Texas: however, it is
expected to weaken as it lifts northeastward into the region on
Thursday. It will also be coming into a dry airmass beneath a
prevailing surface ridge axis. Forecast soundings show gradual
moistening from the top-down later tonight, but the lowest levels
below 850mb will remain quite dry through 12z. As a result, have
maintained a dry forecast through the overnight hours. Due to the
initially clear skies and low dewpoints, have gone a couple of
degrees below MAV guidance for lows tonight, with readings dropping
into the teens and lower 20s.
&&
.LONG TERM...(Thursday through Wednesday)
ISSUED AT 245 PM CST WED DEC 17 2014
Upper flow will be zonal for next few days, with weak waves moving
east through flow. Moisture channel data and upper air shows initial
wave to affect region over NM this morning. This system to
continue tracking to the northeast, pushing some overrunning pcpn
into MO and southern 1/2 of IL for late tonight into Thursday. Weak
vort lobe and isentropic lift to be enough to move the light snow
into southern 1/2 of CWA in the morning, but wave moving fast enough
to only affect the morning. Mainly less than half inch.
Next wave to move into region for Friday night and Saturday morning
and the area of lift with this one is farther south, mainly over
southeast cwa. Again, some light snow possible.
Upper flow starts to change on late in weekend and by Monday, flow
is northwest. Digging upper trough over Great Lakes with upper low
closing off by Monday night. This will bring some initial pcpn into
the region ahead of cold front that moves through Tuesday.
Temperatures however, are only cold enough for possible mixture
until post frontal on Tuesday night and Wednesday. Therefore no snow
accumulation. However by tues night to Wed, only minor vort lobes
rotating around the closed upper low in the cold air, so chance of
light snow accumulations only.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
ISSUED AT 1203 PM CST WED DEC 17 2014
MVFR ceilings will prevail at the central Illinois terminals for
the next few hours before clearing gradually develops from west to
east across the area. 1730z visible satellite imagery shows
clearing beginning to work into the northwest KILX CWA around
Galesburg, and based on timing tools, this should reach KPIA by
around 21/22z. Will continue to monitor satellite to see if clouds
can erode faster, but for now will remain pessimistic. Clouds will
hold firm further east at KCMI until early evening when forecast
soundings finally show low-level drying. After a brief period of
mostly clear skies tonight, the next approaching system will
spread clouds back into the area on Thursday. Forecast soundings
suggest VFR ceilings developing across central Illinois between 11z
and 14z. May see enough moistening of the profile to produce light
snow at KSPI after 15z, but dry conditions should prevail
elsewhere.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Goetsch
AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1212 PM CST WED DEC 17 2014
.SHORT TERM...
315 AM CST
THROUGH THURSDAY...
THE SYSTEM THAT BROUGHT A RETURN TO MORE SEASONAL TEMPERATURES IS
NOW CENTERED OVER THE EASTERN GREAT LAKES. THIS UPPER LOW IS
ROTATING AROUND A NOW DEEPER BUT SHEARING UPPER LOW CENTERED OVER
MINNESOTA AND WISCONSIN EARLY THIS MORNING. AT THE LOW-LEVELS THIS
SLOW MOVING PATTERN IS HELPING KEEP COLD AIR ADVECTION IN PLACE.
WHILE NOT PARTICULARLY STRONG FOR DECEMBER...THIS ADVECTION WITHIN
CYCLONIC FLOW HAS HELPED KEEP THE CLOUDS AND EVEN SOME FLURRIES.
EARLY MORNING SATELLITE IMAGERY INDICATES THE BACK EDGE CLEARING
FROM MINNEAPOLIS TO DES MOINES AND MAKING LITTLE PROGRESS. UPSTREAM
00Z SOUNDINGS AND CURRENT ACARS DATA FROM RFD INDICATE THE MOISTURE
DEPTH IS VERY SHALLOW. SO CERTAINLY THERE IS POTENTIAL TO SCATTER
FROM WEST TO EAST TODAY AND HIGH RESOLUTION GUIDANCE AND CONDENSATE
FIELDS DO PAINT THIS PICTURE AS WELL. GIVEN FURTHER STRENGTHENING OF
THE SUBSIDENCE INVERSION ON FORECAST SOUNDINGS ACROSS NORTH CENTRAL
ILLINOIS...HAVE GONE WITH FORECAST SCATTERING THERE BY EARLY
AFTERNOON. A LITTLE MORE TRICKY TOWARD CHICAGO AND NORTHWEST INDIANA
AND HAVE FAVORED THAT AREA REMAINING AT LEAST MOSTLY CLOUDY THROUGH
MUCH OF TODAY.
HIGH TEMPERATURES TODAY LOOK TO BE THEIR COOLEST IN ABOUT A WEEK
WITH UPPER 20S AND LOWER 30S SUPPORTED GIVEN LITTLE DIURNAL CLIMB
EXPECTED. THIS IS JUST A TAD BELOW MID-DECEMBER NORMALS. AS FOR
TONIGHT...LIKE A SONG ON REPEAT...THE CONFIDENCE ON CLOUDS ONCE
AGAIN IS LOW. WHILE SOME AREAS MAY SEE NOT MUCH FOR CLOUDS IN THE
EVENING...HIGH CLOUDS LOOK TO MOVE NORTHWARD OVER THE AREA LATE
TONIGHT. WITH LIGHTER WINDS THE POTENTIAL EXISTS FOR TEMPERATURES TO
DROP INTO THE LOWER TO MID TEENS IN OUTLYING AREAS.
THE GREAT LAKES BROAD UPPER LOW WILL MOVE EAST ON THURSDAY WEAKENING
THE CONFLUENT UPPER FLOW OVER THE FORECAST AREA. THIS WILL HELP A
SOUTHERN STREAM SYSTEM...CENTERED IN EASTERN ARIZONA EARLY THIS
MORNING...TO MAKE SOME INROADS WITH MID-LEVEL WARM AND MOIST
ADVECTION UP TO AT LEAST CENTRAL ILLINOIS AND INDIANA. THIS SHOULD
BRING CLOUDS TO MUCH OF THE AREA. HAVE NOT INCLUDED ANY LIGHT SNOW
IN THE FAR SOUTHERN AREA AT THIS TIME AS THE SUPPORT FOR LIFT STAYS
JUST SOUTH ON MOST GUIDANCE SOLUTIONS.
MTF
&&
.LONG TERM...
315 AM CST
FRIDAY THROUGH TUESDAY...
SURFACE HIGH PRESSURE RIDGING BASICALLY MAINTAINS ITSELF OVER THE
AREA THROUGH THE WEEKEND. THE UPPER PATTERN REMAINS SOMEWHAT SPLIT
WITH A SYSTEM LIKELY ENTIRELY PASSING TO OUR SOUTHEAST ON SATURDAY.
A NORTHERN STREAM UPPER LOW IS FORECAST TO BRING SOME PACIFIC
MOISTURE...MAINLY ALOFT...OVER THE AREA SATURDAY EVENING/OVERNIGHT.
LIFT IS WEAK AND MAINLY FOCUSED NORTH SO DO NOT HAVE ANY
POPS...HOWEVER HAVE INCREASED CLOUD COVER IN THE FORECAST AND WITH
THAT FORECAST MINS ON SATURDAY NIGHT.
THE WEATHER PATTERN ACROSS THE CENTRAL CONUS HAS BEEN CONSISTENTLY
FORECAST BY LONG RANGE MODELS AND ENSEMBLES TO BECOME MORE AMPLIFIED
DURING NEXT WEEK. JUST LOOKING ON HEMISPHERIC WATER VAPOR THIS
MORNING...MULTIPLE SYSTEMS ON ACTIVE JET ARE SEEN ACROSS THE
NORTHERN PACIFIC...SO A PATTERN SHIFT SEEMS LIKELY. THE CONSENSUS OF
GUIDANCE FAVORS AN ANOMALOUS SURFACE REFLECTION TO DEVELOP ACROSS
THE MIDWEST MONDAY INTO TUESDAY...THOUGH AS ONE CAN EXPECT THERE ARE
LARGE DIFFERENCES IN PLACEMENT. HAVE INCREASED FORECAST POPS IN
LINE WITH A SMART GUIDANCE BLEND. GIVEN A CONSENSUS PLACEMENT
THOUGH...IT WOULD SEEM PROFILES WOULD BE MILD ENOUGH FOR MAINLY RAIN
AT FIRST IN OUR AREA. CERTAINLY THIS BECOMES A LOT MORE IN QUESTION
AS THE TROUGH FURTHER AMPLIFIES SUCH AS MODELS SUGGEST INTO
TUESDAY AND CHRISTMAS EVE.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* MVFR CEILING TRENDS AND POSSIBLE SCATTERING.
* WIND TRENDS...GUSTINESS TODAY AND VARIABLE LATE TONIGHT.
LENNING
//DISCUSSION...UPDATED 18Z...
CEILINGS ARE HANGING IN THE MVFR RANGE BUT SHOWING SIGNS OF
SCATTERING OUT IN AREAS WEST OF THE ORD/MDW TERMINALS. GIVEN THE
PERSISTENCE OF THIS COULD SHIELD IT IS HARD TO PUSH THE CLEARING
INTO THE AREA BEFORE WE ACTUALLY SEE IT HAPPENING...SO FOR NOW WILL
MAINTAIN CURRENT TRENDS INTO THE OVERNIGHT HOURS. WINDS REMAIN
WESTERLY TO NORTHWESTERLY FOR MOST OF THE PERIOD...BUT BY TOMORROW
A WEAKENING PRESSURE GRADIENT MAY ALLOW WINDS TO GO VARIABLE FOR A
TIME...BUT LIKELY CONTINUE TO FAVOR A WESTERLY COMPONENT.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN CEILING TRENDS.
* HIGHER CONFIDENCE IN WIND TRENDS.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT THROUGH SATURDAY...DRY/VFR. LIGHT/VRB WINDS.
* SUNDAY...DRY. MVFR POSSIBLE. SOUTH WINDS.
* MONDAY...CHANCE OF RAIN. MVFR LIKELY. GUSTY SOUTH WINDS.
* TUESDAY...CHANCE OF RAIN. IFR POSSIBLE. SOUTHWEST WINDS.
&&
.MARINE...
210 AM...LOW PRESSURE NEAR LAKE ONTARIO WILL MOVE EAST AND BE
ABSORBED BY LOW PRESSURE MOVING NORTH ALONG THE NEW ENGLAND COAST.
THIS LOW WILL THEN SLOWLY LIFT NORTHEAST AND DEEPEN OVER THE NEXT
FEW DAYS. A LARGE AREA OF HIGH PRESSURE EXTENDING FROM MANITOBA
INTO THE CENTRAL PLAINS WILL SLOWLY BUILD EAST ACROSS THE LAKES
REGION THURSDAY AND FRIDAY. NORTHWEST WINDS TO 30 KTS IN BETWEEN
THESE TWO SYSTEMS WILL GRADUALLY DIMINISH TONIGHT INTO THURSDAY.
AS THE HIGH DRIFTS ACROSS THE LAKES REGION...THERE WILL BE A
PERIOD OF LIGHT PERHAPS EVEN CALM WINDS FRIDAY NIGHT INTO SATURDAY
NIGHT UNTIL THE HIGH MOVES EAST SUNDAY AND SUNDAY NIGHT AND THE
FLOW TURNS BACK SOUTHERLY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 10 AM THURSDAY.
&&
$$
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
1203 PM CST Wed Dec 17 2014
.UPDATE...
ISSUED AT 950 AM CST WED DEC 17 2014
Clouds continue to blanket central and southeast Illinois this
morning, thanks to low-level moisture trapped beneath a subsidence
inversion at around 900mb. Enough synoptic lift is being generated
by a short-wave trough sinking southward through Wisconsin to trigger
a few snow flurries across the area. Radar imagery has shown some
weak echoes from near Peoria southeastward along the I-74
corridor, with both KBMI and KCMI reporting flurries at some
point this morning. Have updated the forecast to include scattered
flurries across the northern KILX CWA accordingly. Main question
of the day will be whether or not any clearing will occur. Latest
visible satellite imagery shows clearing across much of Iowa, as
well as central/southern Missouri. Based on timing tools, skies
will clear across the Illinois River Valley this afternoon, then
toward the I-55 corridor by late afternoon/early evening. Have
adjusted sky grids to better reflect current trends, featuring
partly sunny skies across the west this afternoon and continued
overcast conditions further east toward the Indiana border.
&&
.SHORT TERM...(Today)
ISSUED AT 310 AM CST WED DEC 17 2014
A north-south oriented elongated high pressure ridge will edge
eastward toward Illinois today bringing with it a much lighter
surface pressure gradient and subsidence aloft. The result will be
wind speeds and gusts tapering off throughout the day as well as
thinning low cloud cover. Seasonably cold temperatures that arrived
after yesterday`s cold front will continue, with highs today only
around the freezing mark, just a few degrees below normal.
Although cloud cover will thin out through the day, current
indications are that the GFS and HRRR models are too aggressive in
clearing out low level moisture trapped below an inversion based
just below 900 mb. Forecast cloud cover is based more in line with
the NAM which keeps a saturated layer through the early part of
the day, slowly thinning through the afternoon. Meanwhile, periods
of high cloud cover will be arriving in the afternoon as well.
Also watching a band of snow flurries moving southward through Iowa
this morning. This looks as if it will remain west of the central IL
forecast area before the disturbance responsible for it ejects
eastward. This could move through portions of central IL later this
morning, but would be of very little consequence and is a fairly low
probability at this point.
&&
.LONG TERM...(Tonight through Tuesday)
ISSUED AT 310 AM CST WED DEC 17 2014
Upper wave currently pushing through Arizona on track to reach the
southern Plains tonight, before dampening out somewhat as it moves
across Missouri. Forecast soundings off most of the models are
showing the column moistening from the top down overnight, but very
dry air lingers just past sunrise below 800 mb. A short period of
isentropic lift on the 305K plane will move through central Illinois
Thursday morning, coinciding with the moistening of the lower
layers, resulting in a period of light snow across the southwestern
CWA during the morning. Current thinking is only a few tenths from
Rushville through Springfield to the Effingham/Flora areas. The
soundings further northeast toward Peoria and Bloomington generally
never really moisten the lower levels (except for the NAM), and will
keep those areas dry on Thursday.
Model trends for the Friday night/Saturday system continue to shift
more to the south, as the next deepening wave tracks into the lower
Mississippi Valley. Have limited the PoP`s for Friday night and
Saturday morning to areas south of I-70, where accumulations look to
be less than an inch. The ECMWF tries to draw some of the moisture
northward Saturday morning as a separate wave in the northern stream
swings into the Great Lakes region, so have kept some slight chances
during the morning across east central Illinois.
Active period setting up next week, as a broad long wave trough digs
southward through the central U.S. Some timing differences as to the
depth of this wave, with the ECMWF and parallel GFS cutting off a
low over southeast South Dakota and drifting it east, while the
operational GFS waits until mid week to cut off a broad low over the
Midwest. Both solutions yield precipitation as a storm system
organizes just to our northwest. Have continued to concentrate the
precip chances Monday night into Tuesday, mostly rain but perhaps
some snow mixed in across the far north. Will need to watch the
evolution of this closely, with the pre-holiday travel rush
beginning around this time.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
ISSUED AT 1203 PM CST WED DEC 17 2014
MVFR ceilings will prevail at the central Illinois terminals for
the next few hours before clearing gradually develops from west to
east across the area. 1730z visible satellite imagery shows
clearing beginning to work into the northwest KILX CWA around
Galesburg, and based on timing tools, this should reach KPIA by
around 21/22z. Will continue to monitor satellite to see if clouds
can erode faster, but for now will remain pessimistic. Clouds will
hold firm further east at KCMI until early evening when forecast
soundings finally show low-level drying. After a brief period of
mostly clear skies tonight, the next approaching system will
spread clouds back into the area on Thursday. Forecast soundings
suggest VFR ceilings developing across central Illinois between 11z
and 14z. May see enough moistening of the profile to produce light
snow at KSPI after 15z, but dry conditions should prevail
elsewhere.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Barnes
SHORT TERM...Onton
LONG TERM...Geelhart
AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS DES MOINES IA
306 PM CST WED DEC 17 2014
.SHORT TERM /TONIGHT/...
ISSUED AT 245 PM CST WED DEC 17 2014
A QUIET AFTERNOON IS IN STORE FOR THE CWA WITH SURFACE HIGH PRESSURE
ANCHORED ALONG THE MISSOURI RIVER VALLEY. A SHARP 300 MB SHORTWAVE
TROUGH CURRENTLY EJECTING FROM THE FOUR CORNERS REGION WILL ENTER
SOUTHWEST IOWA BY 12Z THURSDAY. NAM/GFS ARE TOO SLOW WITH RETURNING
MID-LEVEL MOISTURE (MANIFESTING ITSELF AS AN ALTOSTRATUS DECK) NOW
WELL INTO SW IOWA AS WELL AS WITH PRECIP COVERAGE WITH THIS SYSTEM
IN OKLAHOMA. THE HRRR BEST REFLECTS REALITY IN TERMS OF PRECIP
COVERAGE BUT IS ABOUT 3 HOURS BEHIND THE CURVE WITH CLOUD PLACEMENT.
HAVE SUBSEQUENTLY MANUALLY INCREASED CLOUD COVER OVER THE SW HALF OF
THE CWA AND USED THE HRRR FOR TIMING THE ONSET OF SNOW IN THE
SOUTHWESTERN CWA. LOW TEMPERATURES TONIGHT...ESPECIALLY OVER THE
NORTH...WILL BE DEPENDENT ON HOW QUICKLY CLOUDS CAN ADVECT OVERHEAD.
THESE WILL NEED TO BE MONITORED THIS EVENING AND ADJUSTED UPWARD
SHOULD THE CLOUDS ADVANCE FASTER THAN CURRENTLY FORECAST.
THE FASTER MOISTURE RETURN THROWS JUST ANOTHER WRENCH IN TIMING AND
AMOUNTS OF SNOWFALL IN SOUTHERN IOWA LATE TONIGHT. 12/18Z MODEL BUFR
SOUNDINGS DEPICT A STOUT 925-850MB DRY WEDGE ATTENDANT WITH THE
SURFACE RIDGE...BUT THIS MIDLEVEL MOISTURE MAY SATURATE THE COLUMN
FASTER THAN PROGGED AND LEAD TO HIGHER SNOWFALL TOTALS. OVERALL MADE
LITTLE CHANGES TO THE FORECAST IN THIS RESPECT...BUT DID TIGHTEN THE
POP GRADIENT AS IT ADVANCES NORTHEAST FROM 09 TO 12Z THINKING THAT
THE LOW LEVEL DRY AIR WILL RESULT IN A SHARP CUTOFF IN ACCUMULATING
SNOW.
.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 245 PM CST WED DEC 17 2014
A FEW CHALLENGES OVER THE EXTENDED PERIOD...WITH A NUMBER OF WEAK
SYSTEMS TO AFFECT PORTIONS OF THE AREA THROUGH THE PERIOD. SPLIT
FLOW CONTINUES TO BE THE MAIN DRIVING FORCE BEHIND THE RATHER
QUIESCENT WEATHER FOR MID DECEMBER. RATHER HIGH AMPLITUDE RIDGE OF
HIGH PRESSURE STILL ANCHORED FROM THE NORTHERN PLAINS TO THE GULF
COAST NEXT FEW DAYS. FIRST WAVE CURRENTLY OVER THE SOUTHERN
PLAINS TODAY AND SHOULD MOVE NORTHEAST THROUGH THU MORNING. AHEAD
OF THE WEAK SYSTEM WARM AIR ADVECTION AND LIMITED MOISTURE WILL BE
FORCED UPWARD IN AN AREA OF ISENTROPIC LIFT OVER SOUTHERN IOWA
THURSDAY. THE LIFT AND MOISTURE WILL BE ATTEMPTING TO OVERCOME THE
DRY AIRMASS CURRENTLY IN PLACE...LIMITING OVERALL AMOUNTS. THIS
WILL RESULT IN SOME RATHER LIGHT SNOW DURING THE MORNING HOURS
WITH MINOR ACCUMULATIONS GENERALLY LESS THAN AN INCH. DURING THE
EARLY AFTERNOON HOURS...BUFR SOUNDINGS SHOW THAT WE LOSE ICE
INTRODUCTION ACROSS THE SOUTHWEST AND SOUTH. HAVE INTRODUCED SOME
PATCHY FREEZING DRIZZLE ALONG WITH VERY LIGHT SNOW DURING THE
AFTERNOON HOURS...THOUGH EXPECTATIONS ARE THAT ANY PRECIPITATION
BY THAT TIME WILL BE VERY LIGHT AND LITTLE IF ANY ICE ACCUMULATION
IS EXPECTED. NEXT SYSTEM ARRIVES BY SUNDAY AND MONDAY AND EXTENDS
INTO TUESDAY. LOWER CONFIDENCE MOVING FORWARD WITH A CONSENSUS
SOLUTION AS THE GFS IS QUITE MILD WHILE THE EURO IS NOW SUGGESTING
A SOLUTION WITH MORE SIGNIFICANT DYNAMIC COOLING AS THE PRECIP
ARRIVES INTO MONDAY. THE EURO SUGGESTS MORE SNOW THAN RAIN/SNOW
MIX. GIVEN THE EVENT IS STILL 5 DAYS AWAY...WILL HOLD ONTO CURRENT
MIX TRENDS FOR NOW...AND MONITOR DURING SUBSEQUENT MODEL PACKAGES.
THE ONE TREND THAT IS BEGINNING TO EMERGE IS COLDER AIR AS NEXT
WEEK PROGRESSES. AS A STRONG PACNW STREAM WAVE ADVANCES EAST INTO
THE WESTERN STATES...MIDWEST RIDGE FINALLY BEGINS TO BREAK DOWN
AND BECOME DISPLACED BY A LONG WAVE TROUGH. THIS SHOULD SPELL A
TRANSITION TO A MORE ACTIVE AND COLDER PATTERN TOWARD THE END OF
THE EXTENDED. AS THE WAVE TUESDAY DEEPENS...A RATHER STRONG SFC
WAVE WILL EJECT NORTH NORTHEAST OUT OF EASTERN TEXAS TO EASTERN
MICHIGAN WEDNESDAY. GIVEN THE CURRENT GFS/EURO PACKAGES...THE MAIN
H850 MOISTURE PLUME...BETTER FORCING...AND HIGHER PRECIPITATION
AMOUNTS WILL PROBABLY END UP EAST OF THE REGION. WILL MONITOR FOR
GENERAL WESTWARD DRIFT NEXT SEVERAL PACKAGES...THIS SOMETIMES
OCCURS WITH WINTER STORM EVOLUTION IN MODEL PACKAGES...FIRST
PROJECTING THE EVENT TOO FAR EAST THEN PULLING IT BACK AS THE
EVENT NEARS.
&&
.AVIATION...17/18Z
ISSUED AT 1145 AM CST WED DEC 17 2014
VFR CONDITIONS ARE EXPECTED TODAY AND TONIGHT...THOUGH PATCHES OF
MVFR STRATUS ARE POSSIBLE AROUND MCW AND ALO THIS AFTERNOON BUT
CONFIDENCE WAS NOT HIGH ENOUGH TO MENTION IN THE TAFS. LOWER CIGS
AND SNOW MOVE INTO SOUTHERN IOWA AFTER 06Z...THOUGH HOW FAR NORTH
THE SNOW PROGRESSES WILL BE A CHALLENGE FOR THE DSM/FOD TAFS.
BEST CHANCE OF MVFR CIGS/VSBYS WILL BE AT OTM FROM 12Z TO THE END
OF THE TAF PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SKOW
LONG TERM...REV
AVIATION...SKOW
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1141 AM CST WED DEC 17 2014
.UPDATE...
ISSUED AT 1145 AM CST WED DEC 17 2014
MINOR SKY ADJUSTMENTS WERE MADE FOR THE AFTERNOON FORECAST TO
REFLECT THE CLEARER CONDITIONS IN NORTHERN IOWA. STRATOCUMULUS
DECK IS TRYING TO REFORM OVER THE FAR NE CWA BUT HAS BEEN
STRUGGLING TO ADVANCE MUCH INTO BREMER AND BLACK HAWK COUNTIES.
&&
.SHORT TERM /TODAY/...
ISSUED AT 344 AM CST WED DEC 17 2014
NO SIGNIFICANT WEATHER OF CONCERN TODAY...BUT TEMPS MAY BE A TAD
PROBLEMATIC. RIGHT ENTRANCE REGION OF IA/IL JET SEGMENT AND WEAK
FORCING DRIVEN BY WRN KS SHORT WAVE AHEAD OF SWRN CONUS TROUGH
CONTINUE TO SPREAD TOKEN MID CLOUDS AND PRECIP ALOFT INTO SWRN
IA. FORCING REMAINS OF SIMILAR MAGNITUDE THROUGHOUT THE DAY...IS
MAINLY 3KM AND ABOVE...AND CONTINUES TO ADVANCE INTO SURFACE RIDGE
SO NO PRECIP IS ANTICIPATED THROUGH VALID PERIOD.
MODELS ARE HAVING SOME DIFFICULTY HANDLING CURRENT TEMP REGIME.
TEMPS HAVE COOLED BELOW SOME MODELS WHERE SKIES HAVE CLEARED. HIGH
RES MODELS ARE DOING BETTER THAN TRADITIONAL OPERATIONAL RUNS AS
HRRR...RAP AND GEM REGIONAL MODELS BETTER RESEMBLE REALITY.
QUESTION IS WHETHER TO EXTRAPOLATE THEIR SOLUTIONS INTO THE FUTURE
AS THEY VARY QUITE A BIT. RAP AND GEM REGIONAL KEEP THINGS QUITE
COOL WITH MINIMAL REBOUND WHILE HRRR IS BACK UP TOWARD MODEL
CONSENSUS BY AFTERNOON. EVEN THOUGH WINDS WILL DIMINISH SOMEWHAT
IN THE SURFACE RIDGE...STILL EXPECT SOME MIXING WITHOUT SNOW COVER
SO HAVE ONLY GONE JUST A TOUCH BELOW MODEL CONSENSUS WHICH IS NOT
DISSIMILAR TO MOS SUGGESTIONS.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 344 AM CST WED DEC 17 2014
A WEAK 500 MB TROUGH WILL PROGRESS ACROSS KANSAS AND MISSOURI ON
WEDNESDAY NIGHT AND THURSDAY...SPREADING LIGHT PRECIPITATION THAT
MAY MAKE IT INTO MAINLY SOUTHERN IOWA. HOWEVER...THERE WILL BE A
SURFACE HIGH PRESSURE RIDGE BUILD ACROSS THE STATE DURING THAT
TIME RESULTING IN LOW LEVEL DRY AIR ISSUES AS DEPICTED BY MOST
FORECAST SOUNDINGS. IT APPEARS PROBABLE THAT THERE WILL AT LEAST
BE SOME FLURRIES OR VERY LIGHT SNOW ACROSS OUR SOUTHERN
COUNTIES...BUT FURTHER NORTH PRECIPITATION IS MUCH LESS LIKELY AND
EVEN IN THE SOUTH ANY ACCUMULATIONS SHOULD BE LIGHT. HAVE
MAINTAINED CHANCE POPS LATE WEDNESDAY NIGHT AND THURSDAY MORNING
WITH SNOWFALL AMOUNTS AROUND AN INCH OR LESS AND GENERALLY LIMITED
TO I-80 SOUTHWARD. THERE IS A POSSIBILITY OF FREEZING DRIZZLE AT
TIMES IF THE CLOUD LAYER IS SUFFICIENTLY SHALLOW/WARM...HOWEVER AT
THIS TIME THAT IS AN UNLIKELY SCENARIO AND IT HAS NOT BEEN
INCLUDED IN THE FORECAST DUE TO THE LOW PROBABILITY OF
OCCURRENCE.
FROM THURSDAY NIGHT THROUGH SATURDAY THE AFOREMENTIONED SURFACE
HIGH PRESSURE RIDGE WILL REMAIN ANCHORED JUST TO OUR EAST...FROM
THE GREAT LAKES DOWN ACROSS ILLINOIS...RESULTING IN VERY LIGHT
SOUTHERLY FLOW AND LIKELY SEVERAL MORE DAYS OF LOW STRATUS CLOUDS
THAT WILL LIMIT TEMPERATURE FLUCTUATIONS. HAVE INCREASED CLOUD
COVER FORECAST AND COMPRESSED DIURNAL TEMPERATURE SPREADS
ACCORDINGLY. IT IS PROBABLE THAT THIS WILL MANIFEST AS MORE
DRY BUT CLOUDY AND DREARY WEATHER TO END THE WORK WEEK.
BY SATURDAY A LONGWAVE 500 MB TROUGH WILL BE CROSSING THE ROCKIES
AND SHAPING UP TO BE A BIG PLAYER IN OUR WEATHER FOR THE FIRST
HALF OF NEXT WEEK. THE TROUGH WILL REACH THE HIGH PLAINS AND THE
MIDWEST BY SUNDAY AND SUBSEQUENTLY DEEPEN AS IT IS REINFORCED BY A
SERIES OF SUCCESSIVE SHORTWAVE IMPULSES ENTERING THE TROUGH FROM
WESTERN CANADA. BY TUESDAY BOTH THE ECMWF AND GFS ARE NOW CARVING
OUT A MASSIVE 500 MB TROUGH ACROSS MOST OF THE CONUS...WITH A
CENTRAL CLOSED LOW SOMEWHERE OVER THE UPPER MIDWEST. FOR OUR
FORECAST AREA THIS SCENARIO WILL TRANSLATE INTO A PROLONGED PERIOD
OF PRECIPITATION CHANCES...BEGINNING SOMETIME AROUND SUNDAY OR
SUNDAY NIGHT AND PERSISTING AT INTERVALS AT LEAST THROUGH TUESDAY.
HOWEVER...PRECIPITATION TYPE WILL BE HEAVILY DEPENDENT ON THE
LOCATION OF THE UPPER AND SURFACE LOW PRESSURE CENTERS AND THEIR
ASSOCIATED THERMAL PROFILES. CURRENT LONG RANGE MODEL SOLUTIONS
SUPPORT A FAIRLY LONG PERIOD OF RAIN WITH SNOW MORE LIMITED TO
NORTHERN IOWA AND LATER IN THE EVENT...LIKELY RESULTING IN LOW
SNOWFALL AMOUNTS. HOWEVER...WITH THE SYSTEM STILL FOUR OR FIVE
DAYS AWAY AND NOT EVEN ENTERING THE RAOB NETWORK UNTIL AROUND
FRIDAY...THE SOLUTIONS ARE HARDLY STABLE AND A WIDE RANGE OF
EVENTUAL OUTCOMES IS POSSIBLE SO THE FORECAST WILL LIKELY BE
FLUCTUATING IN THE COMING DAYS. ALL INTERESTS WITH TRAVEL PLANS
AROUND CHRISTMAS SHOULD CONTINUE TO MONITOR THESE TRENDS AND HOPE
THAT TEMPERATURES STAY WARM ENOUGH FOR THE PRECIPITATION TO FALL
PREDOMINANTLY AS RAIN.
&&
.AVIATION...17/18Z
ISSUED AT 1145 AM CST WED DEC 17 2014
VFR CONDITIONS ARE EXPECTED TODAY AND TONIGHT...THOUGH PATCHES OF
MVFR STRATUS ARE POSSIBLE AROUND MCW AND ALO THIS AFTERNOON BUT
CONFIDENCE WAS NOT HIGH ENOUGH TO MENTION IN THE TAFS. LOWER CIGS
AND SNOW MOVE INTO SOUTHERN IOWA AFTER 06Z...THOUGH HOW FAR NORTH
THE SNOW PROGRESSES WILL BE A CHALLENGE FOR THE DSM/FOD TAFS.
BEST CHANCE OF MVFR CIGS/VSBYS WILL BE AT OTM FROM 12Z TO THE END
OF THE TAF PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SKOW
SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...SKOW
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1139 AM CST WED DEC 17 2014
.UPDATE...
ISSUED AT 1133 AM CST WED DEC 17 2014
CLOUDS HAVE BROKEN UP OVER ROUGHLY THE WESTERN HALF OF THE AREA
BUT COLD AIR ALOFT HAS ALLOWED DIURNAL CLOUDS TO DEVELOP. THE
CLEARING WILL SLOWLY MOVE EAST THROUGH THE AFTERNOON BUT THE
EASTERN THIRD OF THE AREA MAY ONLY SEE A PEEK OF SUN PRIOR TO SUNSET.
&&
.SYNOPSIS...
ISSUED AT 348 AM CST WED DEC 17 2014
REGION REMAINS ENTRENCHED IN COLD CYCLONIC FLOW WITH STRATUS AND
A FEW FLURRIES ON BACKSIDE OF EASTERN CONUS LONGWAVE TROUGH
AND EMBEDDED SHEARING CLOSED CIRCULATION OVER THE UPPER MIDWEST.
TEMPS RUNNING ON AVERAGE 20-25 DEGS COLDER FROM 24 HRS AGO WITH
READINGS IN THE UPPER TEENS TO MID 20S... WITH NW WIND 10-15+ MPH
MAKING IT FEEL EVEN COLDER AND MORE LIKE THE SINGLE DIGITS TO
LOWER TEENS. WATER VAPOR IMAGERY SHOWS ACTIVE SOUTHERN BRANCH OF
JET STREAM WITH SEVERAL EMBEDDED PERTURBATIONS MOVING THROUGH THE
SOUTHWESTERN CONUS. PRIMARY DISTURBANCE OF INTEREST WAS LOCATED
NEAR BAJA CA AND EXPECTED TO LIFT OUT ACROSS THE SOUTHERN PLAINS
AND MID-MISSISSIPPI VLY TONIGHT AND THURSDAY... AND MAY BRUSH THE
SOUTHERN CWA WITH SOME LIGHT SNOW OR FLURRIES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 348 AM CST WED DEC 17 2014
MAIN CHALLENGES ARE CLOUD TRENDS WITH IMPACT ON TEMPS... AND THE
POTENTIAL FOR LIGHT SNOW ACROSS THE SOUTHERN CWA LATE TONIGHT.
FOG ENHANCEMENT SATL IMAGERY SHOWS THE BACK EDGE OF THE STRATUS
MAINLY ALONG AND EAST OF I-35 PROGRESSING SLOWLY E/SE WITH
MORE EXPANSIVE AREA OVER SOUTHEAST MN MOVING NEARLY DUE SOUTH
AHEAD OF SHEARING CLOSED CIRCULATION. THE LATEST RAP SOUNDINGS
SUGGEST STRATUS MAY REMAIN TRAPPED UNDER INVERSION FOR MOST OF
THE DAY... WHILE NAM WOULD MAINTAIN STRATUS THROUGH MID AM BEFORE
BREAKING UP FROM WEST TO EAST. MODELS IN GENERAL HAVE BEEN TOO
OPTIMISTIC WITH CLEARING TRENDS... BUT WITH FLOW BECOMING MORE
ANTICYCLONIC TO NEARLY NEUTRAL AHEAD OF PLAINS SFC RIDGE BUILDING
IN AND AS A MID LEVEL SUBSIDENCE REGION SOUTH OF SHEARING CLOSED
CIRCULATION OVERSPREADS THE AREA TODAY BELIEVE PROSPECTS GOOD
FOR AT LEAST PARTIAL CLEARING LATER TODAY AND INTO THIS EVENING.
WHERE STRATUS BREAKS UP EXPECT SOME HIGH THIN CIRRUS ESPECIALLY
SOUTH HALF AHEAD OF SOUTHWEST SYSTEM. AS CLOUDS GO... SO GO THE
TEMPS AND HAVE STAYED NEAR GUIDANCE BLEND OR ON THE COLD SIDE WITH
HIGHS FROM MID 20S TO LOWER 30S. IF STRATUS REMAINS TRAPPED
UNDER THE INVERSION ALL DAY PER RAP SOUNDINGS THEN TEMPS STRUGGLE
WITH WIDESPREAD MID TO SOME UPPER 20S. GRADIENT TO WEAKEN TODAY
ESPECIALLY THIS AFTERNOON SO WINDS BECOMING MUCH LESS OF A FACTOR
ON THE CHILLS.
TONIGHT... SHORTWAVE TROUGH PROGGED TO LIFT FROM SOUTHERN PLAINS
TOWARD THE MID-MISSISSIPPI VLY BY 12Z ALTHOUGH IT LOOKS TO
DAMPEN/WEAKEN MARKEDLY AS IT MOVES INTO UPPER RIDGING OVER THE
MIDWEST. MODEL TIME-HEIGHT PLOTS AND SOUNDINGS DEPICT INCREASING
MID-HIGH LEVEL MOISTURE OVERNIGHT MAINLY SOUTHWESTERN 1/3-1/2 OF
THE CWA. GEM...GFS AND ECMWF ALL GENERATE SOME VERY LIGHT QPF
ACROSS THE FAR SOUTHWEST CWA LATE TONIGHT... BUT CLOSER INSPECTION
OF SOUNDINGS SHOW LOW LEVELS REMAIN DRY AND SATURATION INCOMPLETE
FOR MORE THAN JUST FLURRIES. GIVEN THAT THIS WILL BE VERY LATE
(AFT 09Z) DEVELOPING AND LOW CONFIDENCE WITH SATURATION COMPOUNDED
BY WEAKENING SYSTEM HAVE OPTED TO KEEP FCST DRY FAR SOUTH AND OMIT
ANY MENTION OF FLURRIES FOR NOW. LOWS QUITE CHALLENGING DUE TO
CLOUD COVER TRENDS. HAVE KEPT LOWS WITH GUIDANCE BLEND OR ON THE
COOL SIDE AND IN THE TEENS TO AROUND 20 DEGS. 850 MB TEMPS OF
AROUND -5C COUPLED WITH NEAR CALM WINDS AND ANY CLEARING WOULD
SUPPORT COLDEST MINS OF MID TEENS 13-16F.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 348 AM CST WED DEC 17 2014
FORECAST FOCUS ON A CHANCE OF LIGHT SNOW IN OUR FAR SOUTH THURSDAY
THEN ANOTHER CHANCE OF PRECIPITATION EARLY NEXT WEEK.
THURSDAY...OPERATIONAL MODELS DISAGREE ON MOISTURE/SATURATION AS A
SHORT WAVE TRACKS FROM THE SOUTHERN ROCKIES INTO THE MID MS VALLEY
IN THE MORNING. THE ECMWF/GEM ARE THE MOST AGGRESSIVE WITH LIGHT QPF
IN OUR SOUTHERN CWA WHILE THE AMERICAN MODELS ARE ESSENTIALLY DRY.
FORECAST SOUNDINGS INDICATE DRY LOW LEVELS SO IT WILL REMAIN TO BE
SEEN HOW MUCH THE LOW LEVELS CAN SATURATE. FOR COLLABORATION REASONS
I HAVE BUMPED UP POPS TO 40 IN EXTREME NORTHEAST MO...WITH SLIGHTS
AS FAR NORTH AS A FAIRFIELD TO MACOMB LINE. FARTHER NORTH IN THE CWA
THE DRY AIR IS FIRMLY ENTRENCHED WITH HIGH PRESSURE CENTERED IN THE
UPPER MIDWEST. ANY ACCUMULATIONS WILL BE MINOR AND WE ARE TALKING
ONLY A COUPLE OF TENTHS OF AN INCH IN EXTREME NORTHEAST MO. THE WAVE
MOVES QUICKLY INTO THE OHIO VALLEY DURING THE AFTERNOON WITH
LINGERING FLURRIES POSSIBLE. I HAVE LOWERED POPS IN THE AFTERNOON IN
OUR FAR SOUTH TO LESS THAN 20. MAXIMUM TEMPERATURES WILL RANGE FROM
THE UPPER 20S NORTH TO THE LOWER 30S SOUTH.
FRIDAY THROUGH SUNDAY...STORM SYSTEM IN THE SOUTHERN STREAM IS STILL
INDICATED BY MODELS TO REMAIN WELL SOUTH OF THE CWA. AN UPPER LEVEL
TROUGH MOVES ACROSS THE MIDWEST BUT AIRMASS IS TOO DRY TO MENTION
ANY MEASURABLE PRECIPITATION...AS THE DEEPER MOISTURE IS TIED TO THE
SOUTHERN STREAM STORM. HIGH TEMPERATURES DURING THIS PERIOD WILL BE
MAINLY IN THE 30S WITH LOWS IN THE 20S.
MONDAY AND TUESDAY...NEXT IN YOUR HIT PARADE IS A DEEPENING TROUGH
THAT DIGS INTO THE MIDWEST. OPERATIONAL MODELS ARE FAIRLY SIMILAR
WITH THIS FEATURE. HIGH END CHANCE POPS ARE IN THE GRIDS FOR THIS
SITUATION BUT PLENTY OF ROOM TO GO HIGHER OVER THE NEXT SEVERAL DAYS.
WITH THE SURFACE LOW REMAINING TO OUR NORTH THIS SETS UP THE
POTENTIAL FOR RAIN OR A RAIN/SNOW MIX BUT THEN TURNING TO ALL SNOW
BY THE TIME WE GET TO TUESDAY AFTERNOON AND TUESDAY NIGHT.
REMAINDER OF CHRISTMAS WEEK...MODELS HAVING DIFFICULTY WITH PHASING
ISSUES AS THE 00Z/17 ECMWF CRANKS UP A WHOPPER OF A WINTER STORM
(BOMBOGENESIS) TRACKING FROM THE LOWER MS VALLEY TO THE GREAT LAKES
CHRISTMAS EVE...WITH ARCTIC AIR PLUNGING QUICKLY INTO THE COUNTRY
BEHIND THE SYSTEM. THE GFS IS FARTHER EAST AND DEEPENS THE STORM IN
NEW ENGLAND INSTEAD. BEING A WEEK AWAY THERE LIKELY WILL BE MORE
CHANGES BUT CHRISTMAS TRAVELERS WILL WANT TO STAY TUNED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1133 AM CST WED DEC 17 2014
MVFR CIGS WILL SLOWLY CLEAR ACROSS EASTERN IOWA AND NORTHERN
ILLINOIS THROUGH 00Z/18 AS HIGH PRESSURE BUILDS INTO THE MIDWEST.
AFT 00Z/18 VFR CONDITIONS ARE EXPECTED THROUGH 12Z/18. AFT 12Z/18
SNOW WILL SLOWLY MOVE INTO SOUTHEAST IOWA PRODUCING MVFR AND
POSSIBLY IFR CONDITIONS.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...05
SHORT TERM...05
LONG TERM...HAASE
AVIATION...08
AREA FORECAST DISCUSSION
NWS JACKSON KY
340 PM EST WED DEC 17 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 310 PM EST WED DEC 17 2014
19Z SFC ANALYSIS SHOWS HIGH PRESSURE STARTING TO MORE EFFECTIVELY
MOVE INTO THE AREA. THIS IS BEGINNING TO BREAK UP THE LOW LEVEL CLOUD
COVER ACROSS AT LEAST THE SOUTHERN HALF OF THE CWA. THESE CLOUDS HAVE
KEPT TEMPERATURES IN CHECK SO FAR TODAY WITH READINGS GENERALLY IN
THE MID TO UPPER 30S NORTH AND IN THE LOWER 40S IN THE SOUTHEAST
WHERE SOME EARLY SUNSHINE IS MAKING ITS PRESENCE FELT. DEWPOINTS HAVE
DRIED OUT THROUGH THE DAY AND ARE NOW IN THE UPPER 20S TO LOWER 30S.
WINDS HAVE BEEN RELATIVELY LIGHT GENERALLY FROM THE WEST AT 5 TO 10
KTS TODAY.
THE MODELS ARE NOW IN PRETTY GOOD AGREEMENT ALOFT THROUGH THE SHORT
TERM PORTION OF THE FORECAST. THEY ALL DEPICT THE CLOSED...BUT
PROGRESSIVE...UPPER LOW THAT WILL SKIRT EAST THROUGH THE LOWER GREAT
LAKES THIS EVENING AND OVERNIGHT. A BRIEF PERIOD OF RIDGING WILL
FOLLOW INTO THURSDAY MORNING FOR EASTERN KENTUCKY BEFORE A RATHER
DAMPENED WAVE MOVES THROUGH LATER IN THE DAY AND THAT NIGHT WITH
SOME WEAK MID-LEVEL ENERGY FLOWING INTO THE CONFLUENCE ZONE EAST OF
THE AREA. WITH THE GENERAL MODEL AGREEMENT HAVE FOLLOWED THE HIGH
RESOLUTION NAM12 AND HRRR MOST CLOSELY FOR WEATHER DETAILS.
SENSIBLE WEATHER WILL FEATURE A BRIEF TIME OF CLEARING THIS EVENING
AND INTO TONIGHT THAT SHOULD ALLOW FOR SOME DECENT RADIATIONAL
COOLING AND RIDGE TO VALLEY TEMPERATURE DIFFERENCES THROUGH MIDNIGHT.
THEREAFTER...HIGH AND MID LEVEL CLOUDS WILL RETURN TO THE AREA FROM
WEST TO EAST AND PUT A CAP ON THE COOLING...LIMITING FURTHER TERRAIN
DIFFERENCES FOR THE REST OF THE NIGHT. THESE CLOUDS WILL ATTEMPT TO
BRING SNOW TO THE SOUTHWESTERN PARTS OF THE AREA BEFORE DAWN...BUT IT
WILL HAVE TO OVERCOME THE DRYING TAKING PLACE ATTM. ACCORDINGLY...
HAVE UNDERCUT QPF AND POPS FROM THE NAM/MET FOR LATE TONIGHT INTO
THURSDAY MORNING. THE AREA OF LOW PRESSURE RESPONSIBLE FOR THE PCPN
THREAT WILL DAMPEN THROUGH THE MORNING AND FADE OUT BY AFTERNOON. FOR
THIS...HAVE LIMITED THE PCPN THREAT TO JUST FLURRIES AND SPRINKLES
FOR THE SECOND HALF OF THE DAY. ADDITIONAL MOISTURE WILL PASS BY TO
THE NORTH LATER THAT EVENING AND A FEW FLURRIES WILL BE POSSIBLE FROM
THIS ALONG WITH ANOTHER COOL NIGHT.
AGAIN USED THE BCCONSSHORT AS A STARTING POINT FOR THE T/TD/WIND
GRIDS FOR THE FIRST 20 HOURS OR SO BEFORE POPULATING WITH THE
SUPERBLEND THEREAFTER. MINOR ADJUSTMENTS WERE MADE FOR TERRAIN
EFFECTS BOTH TONIGHT AND THURSDAY NIGHT. AS FOR POPS...ENDED UP A BIT
UNDER THE MET NUMBERS AND CLOSER TO THE DRIER MAV ONES FOR TONIGHT
AND THURSDAY GIVEN THE DRY AIR THAT WILL BE IN PLACE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 340 PM EST WED DEC 17 2014
FORECAST MODELS ARE IN GOOD AGREEMENT ON AN ACTIVE WEATHER PATTERN
WITH AT LEAST TWO SYSTEMS TO AFFECT US THROUGH THE PERIOD.
THE FIRST STORM OVER THE WEEKEND CONTINUES TO LOOK RATHER WEAK. A
LIGHT RAIN/SNOW MIX WILL MOVE INTO THE AREA OVERNIGHT FRIDAY NIGHT.
THIS WILL CHANGE TO ALL RAIN DURING THE DAY ON SATURDAY...FOLLOWED
BY PERHAPS BY A LITTLE MORE SNOW AS THE PRECIPITATION ENDS SATURDAY
NIGHT. THERE IS JUST NOT A LOT OF COLD AIR IN PLACE AND
PRECIPITATION LOOKS LIGHT SO ANY SNOW ACCUMULATIONS WILL BE VERY
LIGHT WITH THIS SYSTEM...IF ANY OCCUR AT ALL.
A MUCH MORE IMPRESSIVE STORM SYSTEM IS SHOWING UP IN THE COMPUTER
MODELS FOR THE MIDDLE OF NEXT WEEK...WITH DECENT AGREEMENT ON AN
IMPACTFUL SYSTEM JUST IN TIME FOR PEAK HOLIDAY TRAVEL. AN UPPER
LEVEL TROUGH WILL DIG IN OVER THE PLAINS EARLY IN THE WEEK AND
BECOME NEGATIVELY TILTED OVER THE OHIO VALLEY MID WEEK. THIS CAUSES
EXPLOSIVE DEEPENING OF A SURFACE LOW PRESSURE WHICH IS PROGGED TO
DEVELOP AND TRACK OVER US OR VERY CLOSE TO US ON ITS WAY NORTH TO
THE GREAT LAKES. THIS SYSTEM IS STILL WAY TOO FAR OUT IN THE FUTURE
TO PINPOINT EXACTLY WHAT TYPE OF WEATHER WE WILL BE DEALING
WITH...BUT RAIN...WIND AND SNOW ARE ALL ON THE TABLE FROM TUESDAY
THROUGH WEDNESDAY...AND POTENTIALLY BEYOND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 130 PM EST WED DEC 17 2014
DRIER AIR IS FINALLY STARTING TO MAKE IT TO THE SURFACE ACROSS EAST
KENTUCKY AND THIS WILL BRING THE LIGHT PCPN TO END...BUT BKN MVFR
CLOUDS WILL CONTINUE FOR AT LEAST A COUPLE OF HOURS. THESE SHOULD
BREAK UP FROM SOUTHWEST TO NORTHEAST. HOW SUCCESSFULLY IS STILL IN
QUESTION. ALSO...HIGH CLOUDS WILL START BUILDING IN OVER THE AREA
FROM THE WEST AFTER MIDNIGHT...SO ANY REAL CLEARING WILL LIKELY BE
SHORT LIVED. THIS NEXT SYSTEM DOES BRING THE POTENTIAL FOR SOME
LIGHT SNOW LATE TONIGHT/EARLY THURSDAY MORNING FOR MAINLY KSME AND
KLOZ. HOWEVER...LOW LEVEL DRY AIR LOOKS LIKE IT WILL MAKE IT HARD FOR
THE PCPN TO ACTUALLY REACH THE SURFACE. THEREFORE...CONFIDENCE
REMAINS TOO LOW FOR MENTIONING IN TAFS AT THIS TIME. FINALLY...STRONG
WINDS ALOFT MAY BE OF CONCERN OVER THE NEXT 24 HOURS. AN UPPER LEVEL
JET IS DEPARTING THE AREA TAKING ITS STRONG WESTERLY IN THE MID AND
UPPER LEVELS AWAY FROM EASTERN KENTUCKY. SFC HIGH PRESSURE AND THE
STRONG SUBSIDENCE INVERSION STILL IN PLACE WILL KEEP WINDS RELATIVELY
LIGHT ACROSS THE FA THROUGH MIDDAY THURSDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...ABE
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
310 PM EST WED DEC 17 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 310 PM EST WED DEC 17 2014
19Z SFC ANALYSIS SHOWS HIGH PRESSURE STARTING TO MORE EFFECTIVELY
MOVE INTO THE AREA. THIS IS BEGINNING TO BREAK UP THE LOW LEVEL CLOUD
COVER ACROSS AT LEAST THE SOUTHERN HALF OF THE CWA. THESE CLOUDS HAVE
KEPT TEMPERATURES IN CHECK SO FAR TODAY WITH READINGS GENERALLY IN
THE MID TO UPPER 30S NORTH AND IN THE LOWER 40S IN THE SOUTHEAST
WHERE SOME EARLY SUNSHINE IS MAKING ITS PRESENCE FELT. DEWPOINTS HAVE
DRIED OUT THROUGH THE DAY AND ARE NOW IN THE UPPER 20S TO LOWER 30S.
WINDS HAVE BEEN RELATIVELY LIGHT GENERALLY FROM THE WEST AT 5 TO 10
KTS TODAY.
THE MODELS ARE NOW IN PRETTY GOOD AGREEMENT ALOFT THROUGH THE SHORT
TERM PORTION OF THE FORECAST. THEY ALL DEPICT THE CLOSED...BUT
PROGRESSIVE...UPPER LOW THAT WILL SKIRT EAST THROUGH THE LOWER GREAT
LAKES THIS EVENING AND OVERNIGHT. A BRIEF PERIOD OF RIDGING WILL
FOLLOW INTO THURSDAY MORNING FOR EASTERN KENTUCKY BEFORE A RATHER
DAMPENED WAVE MOVES THROUGH LATER IN THE DAY AND THAT NIGHT WITH
SOME WEAK MID-LEVEL ENERGY FLOWING INTO THE CONFLUENCE ZONE EAST OF
THE AREA. WITH THE GENERAL MODEL AGREEMENT HAVE FOLLOWED THE HIGH
RESOLUTION NAM12 AND HRRR MOST CLOSELY FOR WEATHER DETAILS.
SENSIBLE WEATHER WILL FEATURE A BRIEF TIME OF CLEARING THIS EVENING
AND INTO TONIGHT THAT SHOULD ALLOW FOR SOME DECENT RADIATIONAL
COOLING AND RIDGE TO VALLEY TEMPERATURE DIFFERENCES THROUGH MIDNIGHT.
THEREAFTER...HIGH AND MID LEVEL CLOUDS WILL RETURN TO THE AREA FROM
WEST TO EAST AND PUT A CAP ON THE COOLING...LIMITING FURTHER TERRAIN
DIFFERENCES FOR THE REST OF THE NIGHT. THESE CLOUDS WILL ATTEMPT TO
BRING SNOW TO THE SOUTHWESTERN PARTS OF THE AREA BEFORE DAWN...BUT IT
WILL HAVE TO OVERCOME THE DRYING TAKING PLACE ATTM. ACCORDINGLY...
HAVE UNDERCUT QPF AND POPS FROM THE NAM/MET FOR LATE TONIGHT INTO
THURSDAY MORNING. THE AREA OF LOW PRESSURE RESPONSIBLE FOR THE PCPN
THREAT WILL DAMPEN THROUGH THE MORNING AND FADE OUT BY AFTERNOON. FOR
THIS...HAVE LIMITED THE PCPN THREAT TO JUST FLURRIES AND SPRINKLES
FOR THE SECOND HALF OF THE DAY. ADDITIONAL MOISTURE WILL PASS BY TO
THE NORTH LATER THAT EVENING AND A FEW FLURRIES WILL BE POSSIBLE FROM
THIS ALONG WITH ANOTHER COOL NIGHT.
AGAIN USED THE BCCONSSHORT AS A STARTING POINT FOR THE T/TD/WIND
GRIDS FOR THE FIRST 20 HOURS OR SO BEFORE POPULATING WITH THE
SUPERBLEND THEREAFTER. MINOR ADJUSTMENTS WERE MADE FOR TERRAIN
EFFECTS BOTH TONIGHT AND THURSDAY NIGHT. AS FOR POPS...ENDED UP A BIT
UNDER THE MET NUMBERS AND CLOSER TO THE DRIER MAV ONES FOR TONIGHT
AND THURSDAY GIVEN THE DRY AIR THAT WILL BE IN PLACE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 310 PM EST WED DEC 17 2014
THE LONG TERM DISCUSSION WILL BE ISSUED SHORTLY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 130 PM EST WED DEC 17 2014
DRIER AIR IS FINALLY STARTING TO MAKE IT TO THE SURFACE ACROSS EAST
KENTUCKY AND THIS WILL BRING THE LIGHT PCPN TO END...BUT BKN MVFR
CLOUDS WILL CONTINUE FOR AT LEAST A COUPLE OF HOURS. THESE SHOULD
BREAK UP FROM SOUTHWEST TO NORTHEAST. HOW SUCCESSFULLY IS STILL IN
QUESTION. ALSO...HIGH CLOUDS WILL START BUILDING IN OVER THE AREA
FROM THE WEST AFTER MIDNIGHT...SO ANY REAL CLEARING WILL LIKELY BE
SHORT LIVED. THIS NEXT SYSTEM DOES BRING THE POTENTIAL FOR SOME
LIGHT SNOW LATE TONIGHT/EARLY THURSDAY MORNING FOR MAINLY KSME AND
KLOZ. HOWEVER...LOW LEVEL DRY AIR LOOKS LIKE IT WILL MAKE IT HARD FOR
THE PCPN TO ACTUALLY REACH THE SURFACE. THEREFORE...CONFIDENCE
REMAINS TOO LOW FOR MENTIONING IN TAFS AT THIS TIME. FINALLY...STRONG
WINDS ALOFT MAY BE OF CONCERN OVER THE NEXT 24 HOURS. AN UPPER LEVEL
JET IS DEPARTING THE AREA TAKING ITS STRONG WESTERLY IN THE MID AND
UPPER LEVELS AWAY FROM EASTERN KENTUCKY. SFC HIGH PRESSURE AND THE
STRONG SUBSIDENCE INVERSION STILL IN PLACE WILL KEEP WINDS RELATIVELY
LIGHT ACROSS THE FA THROUGH MIDDAY THURSDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...ABE
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1145 AM CST WED DEC 17 2014
.UPDATE...
ISSUED AT 1145 AM CST WED DEC 17 2014
GRAVITY WAVE AND SURFACE CONVERGENCE ZONE IS EXPECTED TO PERSIST
THROUGH THIS AFTERNOON. RADAR RETURNS HAD DIMINISHED SLIGHTLY
DURING THE MORNING...BUT EXPECT SNOW RATES TO INCREASE GRADUALLY
THROUGH THE AFTERNOON WITH CONVERGENCE AND GRAVITY WAVE STILL IN
PLACE. WILL EXTEND WINTER WEATHER ADVISORY FOR BAYFIELD COUNTY
THROUGH 6 PM. ADDITIONAL SNOWFALL THIS AFTERNOON FROM NORTHEAST
DOUGLAS ALONG THE HIGH TERRAIN IN BAYFIELD COUNTY OF UP TO 1.5
INCHES IS EXPECTED...WITH LESS THAN ONE TENTH FARTHER INLAND AND
IN THE LOWER TERRAIN. SNOWS OVER NORTHERN IRON AND NORTHEAST
ASHLAND COUNTY WILL CONTINUE THIS AFTERNOON...AND THE FOCUS SHOULD
SHIFT SLIGHTLY FARTHER WEST ALONG THE HIGH TERRAIN FROM ODANAH
EAST TO HURLEY. ADDITIONAL SNOWFALL OF UP TO 1 IS POSSIBLE IN
THOSE AREAS...WITH LESS THAN ONE TENTH FARTHER INLAND.
UPDATE ISSUED AT 1128 AM CST WED DEC 17 2014
UPDATED FOR THE NEW 18Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM CST WED DEC 17 2014
PRIMARY CONCERN FOR THE SHORT TERM PERIOD WAS LAKE EFFECT SNOWFALL
EVENT THIS MORNING AND INTO TODAY ACROSS THE SOUTH SHORE OF LAKE
SUPERIOR. OTHERWISE SEASONABLE CONDITIONS TODAY AND TOMORROW AS AN
AREA OF HIGH PRESSURE SETTLES IN ACROSS THE NORTHLAND.
EARLY THIS MORNING...OVERNIGHT RADAR RETURNS AND SURFACE
OBSERVATIONS INDICATED WIDESPREAD LIGHT SNOWFALL CONTINUED ACROSS
NORTHERN MINNESOTA. AS NEAR-SURFACE WINDS BACKED TO THE WEST LAKE
EFFECT SNOWFALL ACROSS THE SOUTH SHORE HAD TAPERED OFF...BUT AM
EXPECTING SNOW SHOWERS TO REDEVELOP TOWARDS SUNRISE THIS MORNING.
TEMPERATURES WERE HOLDING STEADY IN THE LOW TEENS ACROSS NORTHERN
MINNESOTA AND IN THE UPPER TEENS TO NEAR 20 IN NORTHWEST WISCONSIN.
WINDS WERE LIGHT OUT OF THE NORTHWEST AT 5 TO 10 KTS.
TODAY...THE WIDESPREAD LIGHT SNOW EARLY THIS MORNING WILL GRADUALLY
TAPER OFF AS WIDESPREAD SUBSIDENCE SETS IN DUE TO HIGH PRESSURE
MOVING INTO THE REGION. SKIES WILL BEGIN TO CLEAR PARTIALLY ALONG
THE INTERNATIONAL BORDER...BUT MOST LOCATIONS WILL REMAIN OVERCAST
DURING DAYLIGHT HOURS. A FEW FLURRIES WILL BE POSSIBLE IN THE LATE
AFTERNOON...BUT ACCUMULATING SNOWFALL WILL END BY MID-MORNING IN
MOST LOCATIONS. THE EXCEPTION WILL BE ALONG THE SOUTH SHORE OF LAKE
SUPERIOR WHERE LAKE EFFECT SNOW SHOWERS WILL REDEVELOP THIS
AFTERNOON AS THE LOW LEVEL WINDS BETTER ALIGN OUT OF THE NORTH. HAVE
DECREASED SNOWFALL AMOUNTS FROM PREVIOUS FORECASTS BASED ON THE
GUIDANCE AND EARLY MORNING OBSERVATIONS WHICH INDICATED LAKE EFFECT
SNOW SHOWERS HAVE TEMPORARILY DISSIPATED DUE TO BACKING OF
NEAR-SURFACE WINDS. RAP SOUNDINGS FOR THE SOUTH SHORE INDICATE THE
BEST LIFT TO BE BELOW THE DENDRITIC GROWTH ZONE...SO WHILE THERE
WILL BE FORCING AND MOISTURE...THE ALIGNMENT OF THE BEST LIFT MAY
RESULT IN LIMITED CRYSTAL GROWTH/AGGREGATION EXCEPT FOR ALONG THE
HIGHER TERRAIN WHERE MORE INTENSE SNOWFALL RATES COULD OCCUR.
DESPITE THESE RESERVATIONS FOR THE LAKE EFFECT SNOWFALL HAVE DECIDED
TO LEAVE THE CURRENT ADVISORY AND WARNING IN PLACE UNTIL WE BEGIN TO
RECEIVE SNOWFALL REPORTS THIS MORNING TO CONFIRM RADAR AND AUTOMATED
SURFACE OBSERVATIONS...BUT AM LEANING TOWARDS AN EARLY CANCELLATION
FOR THE WARNING AS ADDITIONAL AMOUNTS TODAY WILL PROBABLY ONLY BE IN
THE 1 TO 3 INCH RANGE.
HIGHS TODAY IN THE UPPER TEENS TO NEAR 20. WINDS WILL GRADUALLY VEER
TO THE NORTH/NORTHEAST AND WEAKEN TO 5 KTS OR LESS BY THE LATE
AFTERNOON.
TONIGHT...SOME CLEARING ALONG THE ARROWHEAD REGION OVERNIGHT WITH
NEAR CALM WINDS. A FEW LINGERING LIGHT SNOW SHOWERS/FLURRIES ALONG
THE SOUTH SHORE OF LAKE SUPERIOR. LOWS NEAR ZERO ALONG THE
INTERNATIONAL BORDER AND OTHER LOCATIONS WHERE SKIES MIGHT
CLEAR...ELSEWHERE IN THE LOW TEENS.
THURSDAY...INCREASING CLOUDS AS A MID-LEVEL DISTURBANCE MOVES EAST
ACROSS THE NORTHERN PLAINS AND INTO THE UPPER MIDWEST. THE 00Z HIRES
ARW DEPICTS AN AREA OF CONVERGENCE AND SNOW SHOWER DEVELOPING OVER
LAKE SUPERIOR BETWEEN TWO HARBORS AND HERBSTER...GRADUALLY DRIFTING
WEST TO BRING A FEW FLAKES TO THE NORTH SHORE BETWEEN THE TWIN PORTS
AND TWO HARBORS. DECIDED TO THROW IN A MENTION OF FLURRIES IN THIS
REGION AS WINDS APPEAR TO BE FAVORABLE FOR SUCH A DEVELOPMENT. VERY
LOW CONFIDENCE IN PREDICATION OF A MESOSCALE FEATURE LIKE THIS SO
FAR IN ADVANCE...BUT INTERESTING TO SEE THE HIGHER RESOLUTION ARW
MODEL PICK UP ON IT. HIGHS IN THE LOW TO MID 20S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 317 AM CST WED DEC 17 2014
FAIRLY QUIET WEATHER PATTERN FOR THE LATTER HALF OF THE WEEK WITH AN
EXITING RIDGE OF HIGH PRESSURE TO THE EAST AND A MILD AND DRY UPPER
TROUGH DROPPING IN FROM THE NW TO PRODUCE LOW CHANCES FOR VERY LIGHT
SNOW SHOWERS LATE FRIDAY INTO SATURDAY. THE SYNOPTIC FLOW WILL
REMAIN CYCLONIC...BUT RELATIVELY DRY THROUGH THE REST OF THE WEEKEND
PRIOR TO A RE-ENFORCING WAVE EJECTING OUT OF THE NRN ROCKIES WITH AN
ASSOCIATED SFC LOW FORMING OVER THE CENTRAL PLAINS SUN NIGHT AND
TRACKING TO THE EAST INTO THE SRN GREAT LAKES BY MON NIGHT/ TUE
MORNING. THIS SYSTEM WILL PRODUCE WIDESPREAD SNOW SHOWERS ACROSS THE
NORTHLAND LATE SUNDAY INTO EARLY NEXT WEEK...AND ALSO USHER IN A
MUCH COOLER AIR MASS GOING INTO THE MIDDLE OF THE WEEK. SNOW AMOUNTS
APPEAR TO BE RELATIVELY LIGHT AT THIS TIME.
TEMPERATURES EARLY IN THE EXTENDED PERIOD WILL BE ON THE COOL SIDE
WITH HIGHS IN THE 20S AND LOWS IN THE TEENS AND SINGLE DIGITS ABOVE
ZERO ON FRIDAY. A SLIGHT WARM UP WILL BE FELT SAT THROUGH MONDAY
WITH HIGHS IN THE 30S AND LOWS IN THE 20S. THE NEXT DROP IN
TEMPERATURES WILL BEGIN TUESDAY WITH HIGHS BACK DOWN INTO THE 20S
AND OVERNIGHT LOWS IN THE TEENS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1128 AM CST WED DEC 17 2014
THERE HAS BEEN SOME CLEARING OVER NE MINNESOTA FROM THE NORTH THIS
MORNING AS HIGH PRESSURE IN MANITOBA AND NW ONTARIO GRADUALLY
APPROACHES THE MINNESOTA. WHILE MOSTLY CLEAR SKIES HAVE RETURNED
TO KINL/KHIB/KDLH...BKN/OVC MVFR CIGS AND IFR/MVFR VSBYS FROM -SN
FARTHER SOUTH...INCLUDING OVER KBRD AND NW WISCONSIN. THE LATEST
FORECASTS REFLECT A GREATER CONFIDENCE IN CLEARING THIS AFTERNOON
AND THIS EVENING. THE MVFR CONDITIONS WILL LIKELY LINGER AT KBRD
FOR AT LEAST EARLY THIS AFTERNOON...AND KHYR WILL NOT LIKELY
RETURN TO VFR UNTIL SOMETIME LATE THURSDAY MORNING DUE TO GREATER
MOISTURE FLOW FROM LAKE SUPERIOR. CLEAR AND CALM WEATHER IS
EXPECTED FOR MUCH OF NE MINNESOTA TONIGHT AS THE HIGH PRESSURE
MOVES THROUGH THE REGION. FOG COULD DEVELOP LATE TONIGHT AND EARLY
THURSDAY MORNING. HINTED AT THIS BY GIVING A PERIOD OF MVFR VSBYS
AT KINL/KHIB/KDLH/KBRD. MUCH OF THE REGION WOULD LIKELY RETURN TO
CLEAR SKIES AND VFR CONDITIONS BY LATE THURSDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 21 14 24 16 / 30 10 10 0
INL 17 0 20 11 / 10 0 0 0
BRD 17 12 22 14 / 10 0 0 0
HYR 21 13 25 12 / 50 10 10 0
ASX 22 15 25 12 / 60 20 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR WIZ003-004.
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ002.
LS...NONE.
&&
$$
UPDATE...HUYCK
SHORT TERM...JJM
LONG TERM...BJT
AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1128 AM CST WED DEC 17 2014
.UPDATE...
ISSUED AT 1128 AM CST WED DEC 17 2014
UPDATED FOR THE NEW 18Z AVIATION DISCUSSION BELOW.
UPDATE ISSUED AT 524 AM CST WED DEC 17 2014
UPDATED FOR AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM CST WED DEC 17 2014
PRIMARY CONCERN FOR THE SHORT TERM PERIOD WAS LAKE EFFECT SNOWFALL
EVENT THIS MORNING AND INTO TODAY ACROSS THE SOUTH SHORE OF LAKE
SUPERIOR. OTHERWISE SEASONABLE CONDITIONS TODAY AND TOMORROW AS AN
AREA OF HIGH PRESSURE SETTLES IN ACROSS THE NORTHLAND.
EARLY THIS MORNING...OVERNIGHT RADAR RETURNS AND SURFACE
OBSERVATIONS INDICATED WIDESPREAD LIGHT SNOWFALL CONTINUED ACROSS
NORTHERN MINNESOTA. AS NEAR-SURFACE WINDS BACKED TO THE WEST LAKE
EFFECT SNOWFALL ACROSS THE SOUTH SHORE HAD TAPERED OFF...BUT AM
EXPECTING SNOW SHOWERS TO REDEVELOP TOWARDS SUNRISE THIS MORNING.
TEMPERATURES WERE HOLDING STEADY IN THE LOW TEENS ACROSS NORTHERN
MINNESOTA AND IN THE UPPER TEENS TO NEAR 20 IN NORTHWEST WISCONSIN.
WINDS WERE LIGHT OUT OF THE NORTHWEST AT 5 TO 10 KTS.
TODAY...THE WIDESPREAD LIGHT SNOW EARLY THIS MORNING WILL GRADUALLY
TAPER OFF AS WIDESPREAD SUBSIDENCE SETS IN DUE TO HIGH PRESSURE
MOVING INTO THE REGION. SKIES WILL BEGIN TO CLEAR PARTIALLY ALONG
THE INTERNATIONAL BORDER...BUT MOST LOCATIONS WILL REMAIN OVERCAST
DURING DAYLIGHT HOURS. A FEW FLURRIES WILL BE POSSIBLE IN THE LATE
AFTERNOON...BUT ACCUMULATING SNOWFALL WILL END BY MID-MORNING IN
MOST LOCATIONS. THE EXCEPTION WILL BE ALONG THE SOUTH SHORE OF LAKE
SUPERIOR WHERE LAKE EFFECT SNOW SHOWERS WILL REDEVELOP THIS
AFTERNOON AS THE LOW LEVEL WINDS BETTER ALIGN OUT OF THE NORTH. HAVE
DECREASED SNOWFALL AMOUNTS FROM PREVIOUS FORECASTS BASED ON THE
GUIDANCE AND EARLY MORNING OBSERVATIONS WHICH INDICATED LAKE EFFECT
SNOW SHOWERS HAVE TEMPORARILY DISSIPATED DUE TO BACKING OF
NEAR-SURFACE WINDS. RAP SOUNDINGS FOR THE SOUTH SHORE INDICATE THE
BEST LIFT TO BE BELOW THE DENDRITIC GROWTH ZONE...SO WHILE THERE
WILL BE FORCING AND MOISTURE...THE ALIGNMENT OF THE BEST LIFT MAY
RESULT IN LIMITED CRYSTAL GROWTH/AGGREGATION EXCEPT FOR ALONG THE
HIGHER TERRAIN WHERE MORE INTENSE SNOWFALL RATES COULD OCCUR.
DESPITE THESE RESERVATIONS FOR THE LAKE EFFECT SNOWFALL HAVE DECIDED
TO LEAVE THE CURRENT ADVISORY AND WARNING IN PLACE UNTIL WE BEGIN TO
RECEIVE SNOWFALL REPORTS THIS MORNING TO CONFIRM RADAR AND AUTOMATED
SURFACE OBSERVATIONS...BUT AM LEANING TOWARDS AN EARLY CANCELLATION
FOR THE WARNING AS ADDITIONAL AMOUNTS TODAY WILL PROBABLY ONLY BE IN
THE 1 TO 3 INCH RANGE.
HIGHS TODAY IN THE UPPER TEENS TO NEAR 20. WINDS WILL GRADUALLY VEER
TO THE NORTH/NORTHEAST AND WEAKEN TO 5 KTS OR LESS BY THE LATE
AFTERNOON.
TONIGHT...SOME CLEARING ALONG THE ARROWHEAD REGION OVERNIGHT WITH
NEAR CALM WINDS. A FEW LINGERING LIGHT SNOW SHOWERS/FLURRIES ALONG
THE SOUTH SHORE OF LAKE SUPERIOR. LOWS NEAR ZERO ALONG THE
INTERNATIONAL BORDER AND OTHER LOCATIONS WHERE SKIES MIGHT
CLEAR...ELSEWHERE IN THE LOW TEENS.
THURSDAY...INCREASING CLOUDS AS A MID-LEVEL DISTURBANCE MOVES EAST
ACROSS THE NORTHERN PLAINS AND INTO THE UPPER MIDWEST. THE 00Z HIRES
ARW DEPICTS AN AREA OF CONVERGENCE AND SNOW SHOWER DEVELOPING OVER
LAKE SUPERIOR BETWEEN TWO HARBORS AND HERBSTER...GRADUALLY DRIFTING
WEST TO BRING A FEW FLAKES TO THE NORTH SHORE BETWEEN THE TWIN PORTS
AND TWO HARBORS. DECIDED TO THROW IN A MENTION OF FLURRIES IN THIS
REGION AS WINDS APPEAR TO BE FAVORABLE FOR SUCH A DEVELOPMENT. VERY
LOW CONFIDENCE IN PREDICATION OF A MESOSCALE FEATURE LIKE THIS SO
FAR IN ADVANCE...BUT INTERESTING TO SEE THE HIGHER RESOLUTION ARW
MODEL PICK UP ON IT. HIGHS IN THE LOW TO MID 20S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 317 AM CST WED DEC 17 2014
FAIRLY QUIET WEATHER PATTERN FOR THE LATTER HALF OF THE WEEK WITH AN
EXITING RIDGE OF HIGH PRESSURE TO THE EAST AND A MILD AND DRY UPPER
TROUGH DROPPING IN FROM THE NW TO PRODUCE LOW CHANCES FOR VERY LIGHT
SNOW SHOWERS LATE FRIDAY INTO SATURDAY. THE SYNOPTIC FLOW WILL
REMAIN CYCLONIC...BUT RELATIVELY DRY THROUGH THE REST OF THE WEEKEND
PRIOR TO A RE-ENFORCING WAVE EJECTING OUT OF THE NRN ROCKIES WITH AN
ASSOCIATED SFC LOW FORMING OVER THE CENTRAL PLAINS SUN NIGHT AND
TRACKING TO THE EAST INTO THE SRN GREAT LAKES BY MON NIGHT/ TUE
MORNING. THIS SYSTEM WILL PRODUCE WIDESPREAD SNOW SHOWERS ACROSS THE
NORTHLAND LATE SUNDAY INTO EARLY NEXT WEEK...AND ALSO USHER IN A
MUCH COOLER AIR MASS GOING INTO THE MIDDLE OF THE WEEK. SNOW AMOUNTS
APPEAR TO BE RELATIVELY LIGHT AT THIS TIME.
TEMPERATURES EARLY IN THE EXTENDED PERIOD WILL BE ON THE COOL SIDE
WITH HIGHS IN THE 20S AND LOWS IN THE TEENS AND SINGLE DIGITS ABOVE
ZERO ON FRIDAY. A SLIGHT WARM UP WILL BE FELT SAT THROUGH MONDAY
WITH HIGHS IN THE 30S AND LOWS IN THE 20S. THE NEXT DROP IN
TEMPERATURES WILL BEGIN TUESDAY WITH HIGHS BACK DOWN INTO THE 20S
AND OVERNIGHT LOWS IN THE TEENS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1128 AM CST WED DEC 17 2014
THERE HAS BEEN SOME CLEARING OVER NE MINNESOTA FROM THE NORTH THIS
MORNING AS HIGH PRESSURE IN MANITOBA AND NW ONTARIO GRADUALLY
APPROACHES THE MINNESOTA. WHILE MOSTLY CLEAR SKIES HAVE RETURNED
TO KINL/KHIB/KDLH...BKN/OVC MVFR CIGS AND IFR/MVFR VSBYS FROM -SN
FARTHER SOUTH...INCLUDING OVER KBRD AND NW WISCONSIN. THE LATEST
FORECASTS REFLECT A GREATER CONFIDENCE IN CLEARING THIS AFTERNOON
AND THIS EVENING. THE MVFR CONDITIONS WILL LIKELY LINGER AT KBRD
FOR AT LEAST EARLY THIS AFTERNOON...AND KHYR WILL NOT LIKELY
RETURN TO VFR UNTIL SOMETIME LATE THURSDAY MORNING DUE TO GREATER
MOISTURE FLOW FROM LAKE SUPERIOR. CLEAR AND CALM WEATHER IS
EXPECTED FOR MUCH OF NE MINNESOTA TONIGHT AS THE HIGH PRESSURE
MOVES THROUGH THE REGION. FOG COULD DEVELOP LATE TONIGHT AND EARLY
THURSDAY MORNING. HINTED AT THIS BY GIVING A PERIOD OF MVFR VSBYS
AT KINL/KHIB/KDLH/KBRD. MUCH OF THE REGION WOULD LIKELY RETURN TO
CLEAR SKIES AND VFR CONDITIONS BY LATE THURSDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 21 14 24 16 / 30 10 10 0
INL 17 0 20 11 / 10 0 0 0
BRD 17 12 22 14 / 10 0 0 0
HYR 21 13 25 12 / 50 10 10 0
ASX 22 15 25 12 / 60 20 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR WIZ003-004.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR WIZ002.
LS...NONE.
&&
$$
SHORT TERM...JJM
LONG TERM...BJT
AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS BILLINGS MT
231 PM MST WED DEC 17 2014
.SHORT TERM...VALID FOR THU AND FRI...
WEAK UPPER LOW PRESSURE SYSTEM WILL MOVE ACROSS NORTHERN MONTANA
TONIGHT AND WILL BRING AREAS OF LIGHT SNOW THIS EVENING ACROSS OUR
NORTHEAST ZONES. SNOW IS EXPECTED TO BE VERY LIGHT WITH NO
ACCUMULATIONS. AS THE LOW MOVES TO OUR EAST TONIGHT...SOME
CLEARING IS EXPECTED ACROSS OUR WESTERN AND CENTRAL ZONES. THIS
WILL ALLOW FOR COOLER OVERNIGHT LOW TEMPERATURES WITH TEENS TO
LOWER 20S. HRRR IS INDICATING FOG TO REDEVELOP OVER SOUTHERN
POWDER RIVER AND CARTER COUNTIES TONIGHT AS LOW LEVEL MOISTURE
REMAINS POOLED OVER THESE AREAS. DID INCLUDED PATCHY FOG FOR
PORTIONS OF SOUTHEAST MONTANA TONIGHT. WEAK SHORT WAVE TO MOVE
THROUGH THURSDAY WHICH WHICH WILL BRING SCATTERED SNOW SHOWERS TO
OUR SOUTHWEST MOUNTAINS. DRY WEATHER AND SLOWLY WARMING
TEMPERATURES WILL CONTINUE INTO FRIDAY AS SHORT WAVE RIDGING MOVES
IN OVER THE REGION. HIGH TEMPERATURES WILL BE IN THE UPPER 30S TO
LOWER 40S BOTH THURSDAY AND FRIDAY. RICHMOND
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
GUIDANCE CONTINUES TO BE IN GOOD AGREEMENT INTO EARLY NEXT WEEK.
WHILE THE FINER DETAILS MAY DIFFER..THE OVERALL UNSETTLED PATTERN
IN THE EXTENDED CONTINUES. AFTER THE RIDGING FRIDAY...A WEAK
SHORTWAVE WILL CROSS THE STATE...BRING ANOTHER CHANCE FOR LIGHT
PRECIP TO THE MOUNTAINS. UPPER LEVEL FLOW BEGINS TO INCREASE
SATURDAY NIGHT AS A PACIFIC JET STARTS MOVING INTO THE STATE. LEE
SIDE TROUGHING DEVELOPS...WITH A SURFACE LOW DEVELOPING OVER
SOUTHERN ALBERTA. IN RESPONSE...THE PRESSURE GRADIENT TIGHTENS
OVER SOUTHERN MONTANA...RESULTING IN STRONGER WINDS DEVELOPING
FIRST IN THE GAP AREAS...THEN SPREADING OUT TO AROUND BILLINGS.
MEX MOS FOR LIVINGSTON HAS WINDS INCREASING INTO 30 MPH TO NEAR
40 MPH RANGE SUNDAY AFTERNOON. STILL KEEPING GRIDS SUB ADVISORY
GIVEN THIS IS STILL FOUR DAYS OUT...BUT IF CURRENT TRENDS
HOLD...LOOKING AT ANOTHER WIND EVENT DURING THE DAY SUNDAY.
AS THE LOW TRACKS OUT OF CANADA INTO THE NORTHERN PLAINS
MONDAY...A COLD FRONT MOVES THROUGH THE AREA. WITH AMPLE MOISTURE
STILL BRING TRANSPORTED INTO THE AREA...POPS CONTINUE MONDAY INTO
TUESDAY. TEMPERATURES WILL REMAIN RELATIVELY WARM...SO MUCH OF THE
CENTRAL ZONES STILL LOOK TO GET RAIN. FARTHER EAST WARDS MILES
CITY AND BAKER...WHERE TEMPERATURES ARE A BIT COOLER...MAY SEE
SOME FREEZING RAIN. WINDS WILL ALSO BE MORE NORTH WESTERLY...SO
NOT AS MUCH OF AN UP SLOPE FLOW EVENT. THINGS BEGIN TO TAPPER
OFF...WITH TEMPERATURES COOLING BACK INTO THE 30S FOR HIGHS.
LOOKING AHEAD TO CHRISTMAS EVE AND CHRISTMAS...ANOTHER LOW
DEVELOPS AND TRACKS ACROSS MONTANA...GIVING THE AREA A SHOT AT
MORE PRECIP. WITH THE SYSTEM...THE AIR MASS IN PLACE WILL BE
COLDER...WITH 850MB TEMPERATURES BELOW FREEZING. THE THE GFS AND
ECMWF ARE SUGGESTING A SHOT AT A WHITE CHRISTMAS...WILL CONTINUE
TO WATCH THIS. REIMER &&
.AVIATION...
CONDITIONS HAVE IMPROVED THIS AFTERNOON...GENERALLY MVFR TO VFR.
EXPECT FLIGHT CONDITIONS REMAIN VFR/MVFR OVERNIGHT AND INTO
TOMORROW. SOME PATCH FOG WILL BE POSSIBLE SOUTH OF MILES
CITY...BUT WILL LIKELY NOT IMPACT ANY TERMINALS. WITH SOME MID LEVEL
CLOUDS...SOME MOUNTAIN OBSCURATION WILL CONTINUE TO BE POSSIBLE.
REIMER
&&
.PRELIMINARY POINT TEMP/POPS...
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 023/038 023/038 027/041 027/046 033/045 026/038 022/033
00/B 00/B 11/B 13/W 32/W 21/N 23/J
LVM 022/042 024/040 027/043 028/046 035/045 022/039 023/035
01/N 11/N 21/B 24/W 43/W 21/N 33/J
HDN 013/037 015/037 020/040 021/044 029/043 021/037 020/034
10/B 00/B 01/B 13/W 33/W 21/B 22/J
MLS 017/038 019/037 021/040 022/042 029/040 025/036 020/031
20/B 00/B 11/B 13/W 22/W 11/B 11/E
4BQ 015/041 017/040 019/041 022/044 030/042 024/037 019/033
20/B 00/B 11/B 12/W 23/W 21/B 22/J
BHK 015/036 019/037 019/040 021/042 026/037 021/033 017/027
20/B 10/B 01/B 02/W 22/W 11/N 11/B
SHR 015/041 015/038 020/040 019/043 030/042 022/037 019/033
10/B 10/B 11/B 13/W 34/W 32/J 22/J
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
921 AM MST WED DEC 17 2014
.UPDATE...
AREAS OF FOG STILL ON GOING ACROSS THE REGION THIS MORNING AND
WILL CONTINUE THROUGH AT LEAST 19Z FOR MANY AREAS FROM BILLINGS
EAST. DENSE FOG WAS CONTINUING IN THE SHERIDAN AND WILL KEEP THE
DENSE FOG ADVISORY GOING THROUGH AT LEAST 18Z. WEB CAMS AND
SURFACE OBSERVATIONS ALSO INDICATED PATCHY DENSE FOG WAS LOCATED
ACROSS THE SOUTHERN AREAS OF POWDER RIVER AND CARTER COUNTIES.
PATCHY FOG ALSO EXTENDED NORTHWARD FROM THESE AREAS AND HAD PUSHED
WESTWARD INTO THE BILLINGS AREA. HRRR INDICATING FOG IN THESE
AREAS WILL BEGIN BREAKING UP BY MID MORNING AS A WARM FRONT MOVES
ACROSS THE AREA ALLOWING SOME MIXING TO TAKE PLACE.
INCREASE POPS ACROSS THE AREA THIS MORNING AS A WEAK UPPER LEVEL
CIRCULATION ALONG WITH WEAK VORTICITY WAS PRODUCING LIGHT SNOW
SHOWERS OVER THE FORECAST AREA. NO SNOW ACCUMULATIONS ARE EXPECTED
WITH THIS DISTURBANCE. DID LOWER TEMPERATURES A FEW DEGREES AS
CLOUD COVER WILL INHIBIT HEATING THIS AFTERNOON IN SPITE OF WARM
FRONT MOVING THROUGH. RICHMOND
&&
.SHORT TERM...VALID FOR TDY AND THU...
SHERIDAN WAS REPORTING DENSE FOG THIS MORNING AND AREA WEB CAMS
IN SHERIDAN ALSO SHOWED DENSE FOG. LAST FEW RUNS OF THE HRRR
TARGETED THE SHERIDAN FOOTHILLS WITH DENSE FOG AND DISSIPATED IT
BY 19Z. HAVE ISSUED A DENSE FOG ADVISORY FOR THIS AREA THROUGH
18Z. OTHER AREAS E OF KBIL WILL ALSO HAVE FOG...AND SOME OF IT MAY
BE DENSE...BUT DENSE FOG WILL NOT BE WIDESPREAD ENOUGH TO WARRANT
AN ADVISORY.
TWO SHORTWAVES WERE AFFECTING THE AREA EARLY THIS MORNING. ONE WAS
MOVING INTO SW MT AND THE OTHER WAS OVER W MT PER WATER VAPOR
IMAGERY. THESE WAVES WILL MERGE AND CROSS THE AREA TODAY THROUGH
TONIGHT. THE BEST Q-VECTOR CONVERGENCE WILL OCCUR THIS MORNING
WITH THE WAVES...AND MODELS BROUGHT A DECENT AREA OF MOISTURE
ACROSS THE AREA. DETERMINISTIC MODELS AND SREF ALL SHOWED LIGHT
WIDELY SCATTERED QPF TODAY. SO WENT WITH MAINLY SCATTERED
FLURRIES...WITH CHANCE POPS IN THE WESTERN MOUNTAINS THIS MORNING.
CHANCES FOR PRECIPITATION WILL END TONIGHT. A WARM FRONT WILL PUSH
INTO THE REGION TONIGHT AND USHER IN WARMING CONDITIONS THROUGH
THU. ANOTHER WAVE APPROACHES THU AND MOVES INTO THE AREA THU
NIGHT. PRECIPITATION CHANCES WILL BE CONFINED TO THE MOUNTAINS.
TEMPERATURES TODAY WILL BE HIGHER THAN YESTERDAY/S READINGS AND
WILL BE WARMER YET ON THU. ARTHUR
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
MODELS ARE IN DECENT AGREEMENT THROUGH THE EXTENDED PERIOD AS
THEY SHOW AN UNSETTLED PATTERN. MAIN FORECAST ISSUE WILL BE SUNDAY
INTO MONDAY AND AGAIN CHRISTMAS EVE/CHRISTMAS DAY AS THESE
PERIODS SHOW THE LIKELIHOOD OF A STORM SYSTEM IMPACTING THE AREA.
BRIEF RIDGING WILL BE OVER THE FORECAST AREA FRIDAY BEFORE A WEAK
DISTURBANCE MOVES ACROSS THE AREA FRIDAY NIGHT INTO SATURDAY
BRINGING A SLIGHT CHANCE FOR RAIN AND SNOW SHOWERS. AN UNSETTLED
NORTHWEST FLOW ALOFT WILL PREVAIL OVER THE WEEKEND RESULTING IN A
SLIGHT SHOWER CHANCE SATURDAY. LEE-SIDE TROUGHING SETS UP SUNDAY
BEFORE A COLD FRONT MOVES THROUGH MONDAY. TIGHT PRESSURE GRADIENTS
WILL BE ACROSS THE BEARTOOTH/ABSAROKA FOOTHILLS SUNDAY SHIFTING
EAST MONDAY RESULTING IN WINDY PERIODS ACROSS THE AREA.
A CONTINUOUS FLOW OF MOISTURE OFF THE PACIFIC WILL MOVE ACROSS
IDAHO INTO MONTANA SUNDAY INTO MONDAY BRINGING CHANCES FOR SHOWERS
ACROSS THE PLAINS WITH SNOW LIKELY FOR THE MOUNTAINS. THERE WILL
BE A BRIEF BREAK TUESDAY BEFORE THE NEXT STORM SYSTEM IMPACTS OUR
FORECAST AREA WEDNESDAY AND THURSDAY. MODELS ARE IN PRETTY GOOD
AGREEMENT IN CARVING OUT A LARGE TROUGH ACROSS THE NORTHERN
ROCKIES WEDNESDAY AND THURSDAY...AS WELL AS PLACING AN UPPER LOW
IN OUR VICINITY. FORECASTER CONFIDENCE IS HIGH FOR A CHRISTMAS
SNOW EVENT BUT DETAILS SUCH AS SNOW AMOUNTS ARE UNCERTAIN AT THIS
TIME. HOOLEY
&&
.AVIATION...
LOW CEILINGS ALONG WITH AREAS OF DENSE FOG WILL CONTINUE TO POSE
AN AVIATION HAZARD THROUGH THIS MORNING. MVFR TO IFR CONDITIONS
WILL PREVAIL WITH AREAS OF LIFR FROM KSHR TO KBIL THROUGH 18Z. THE
EXCEPTION WILL BE THE KLVM AREA AND ADJACENT FOOTHILLS WHERE VFR
CONDITIONS WILL PREVAIL. THE MOUNTAINS WILL BE OBSCURED AT TIMES
THROUGHOUT THE DAY. HOOLEY/REIMER
&&
.PRELIMINARY POINT TEMP/POPS...
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 033 023/039 023/038 027/042 026/044 035/047 027/041
2/J 00/B 00/B 11/B 23/W 33/W 32/W
LVM 036 022/041 024/040 026/043 026/041 036/047 027/043
3/J 01/N 11/B 21/N 23/W 33/W 33/W
HDN 031 015/037 016/037 020/040 019/041 029/044 023/040
2/J 10/B 00/B 01/B 12/J 33/W 32/W
MLS 028 017/036 019/037 019/039 022/041 029/043 023/039
2/J 10/B 00/B 11/B 12/J 23/W 11/B
4BQ 029 016/039 017/040 017/041 020/043 030/045 024/041
2/J 10/B 00/B 11/B 12/J 23/W 21/B
BHK 022 015/034 018/037 017/039 020/040 027/041 021/037
2/J 20/B 10/B 01/B 11/B 22/W 11/B
SHR 032 016/038 016/038 019/040 019/041 028/043 022/040
2/J 00/B 10/B 12/J 12/J 34/W 32/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...DENSE FOG ADVISORY IN EFFECT UNTIL 11 AM MST THIS MORNING FOR
ZONE 99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
326 PM CST WED DEC 17 2014
.SYNOPSIS...
ISSUED AT 325 PM CST WED DEC 17 2014
AN ACTIVE H5 PATTERN CONTINUES ACROSS THE LOWER 48 TDY
WITH NUMEROUS DISTURBANCES AND A CLOSED LOW NOTED OVER THE CONUS.
CLOSED LOW PRESSURE WAS NOTED OVER LAKE HURON AND EXTENDED WWD INTO
NRN WISCONSIN. HIGH PRESSURE WAS NOTED OVER NRN MANITOBA. ACROSS THE
WESTERN HALF OF THE CONUS...SHORTWAVES WERE NOTED OVER SERN
MT....SWRN NEW MEXICO...AND THE CALIFORNIA DESERT. HT FALLS OF 50 TO
70 METERS EXTENDED FROM EASTERN ARIZONA INTO SWRN KS. IN ASSOCIATION
WITH THE CLOSED LOW OVER THE GREAT LAKES...A NICE 50 TO 90 KT JET
STREAK EXTENDED FROM THE MID MISSOURI RIVER...EAST TO VIRGINIA AND
NORTH CAROLINA. HT FALLS IN ASSOCIATION WITH THE CLOSED LOW WERE
MOST PRONOUNCED OVER NEW ENGLAND...WHERE 50 TO 120 METER FALLS WERE
NOTED. AT THE SURFACE...ARCTIC HIGH PRESSURE WAS ANCHORED ACROSS THE
EASTERN DAKOTAS...SSE INTO MISSOURI. WEST OF THIS FEATURE...WEAK
SERLY WINDS WERE NOTED ALONG WITH PESKY LOW LEVEL CLOUDINESS AND
PATCHY FOG. TEMPERATURES THIS AFTERNOON WERE COLD WITH READINGS IN
THE LOWER 20S ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 325 PM CST WED DEC 17 2014
DESPITE THE MAIN UPPER PV ANOMALY AND ASSOCIATED LARGE SCALE FORCING
IS SOUTH OF THE AREA AND MOVING EASTWARD...SEVERAL FORECASTING
ISSUES REMAIN. THE STRATUS LAYER IS WARM ENOUGH TO CONTAIN
SUPERCOOLED LIQUID AND HENCE FALL TO THE GROUND IN WEAK UPSLOPE FLOW
AS FREEZING DRIZZLE IN SOME AREAS OF SOUTHWEST NEBRASKA THIS
AFTERNOON. RAP BUFR SOUNDINGS SUGGEST MINIMAL LIFT THROUGH THE
REMAINING AFTERNOON HOURS...BUT INCREASING SLIGHTLY THIS EVENING AND
OVERNIGHT. IR SAT PICS SHOW MID LEVEL CLOUDS TRYING TO MOVE OVER THE
TOP OF THE EXISTING LOW LEVEL STRATUS BUT HAVING A HARD TIME AS MID
LEVELS ARE QUITE DRY INITIALLY. BELIEVE THE INCREASING UPWARD
VERTICAL MOTION AS A RESULT OF WEAK MID LEVEL FRONTOGENESIS WILL
EVENTUALLY HELP TO MOISTEN THE MID LEVELS...BUT SOUNDINGS STILL SHOW
TOO MUCH DRY AIR TO CONNECT A SATURATED SNOW PRODUCING LAYER WITH
THE MOIST LOW LEVELS BELOW. THE END RESULT...BASED ON FORECAST
SOUNDINGS...WILL BE FREEZING DRIZZLE ESPECIALLY ACROSS THE SOUTHWEST
PORTION OF NEBRASKA THIS EVENING AND DURING THE OVERNIGHT. NEAR TERM
ENSEMBLES SUGGEST THE POSSIBILITY OF A SMALL BAND OF LIGHT SNOW FROM
SOUTHEAST FRONTIER COUNTY NORTHEASTWARD INTO CUSTER...BUT CONFIDENCE
IN SUCH A SMALL SCALE FEATURE BEING ABLE TO FULLY SATURATE THE
ATMOSPHERIC COLUMN TO SUPPORT LIGHT SNOW IS NOT HIGH...SO HAVE LEFT
PRECIPITATION MENTION AS FREEZING DRIZZLE FOR NOW.
FURTHER NORTH AND WEST...SOUTHERLY AND SOUTHEASTERLY WINDS WILL
CONTINUE TO SUSTAIN MOIST LOW LEVELS IN THE EASTERN PANHANDLE...BUT
MID AND UPPER LEVEL DRYING WILL BE GREATER HERE WHICH LEAVES A
BETTER SCENARIO FOR FOG AND HAVE THEREFORE INCLUDED THAT MENTION
THERE INTO THE MORNING HOURS. FOG WILL BE OCCURRING IN SNOW COVERED
AREAS WHICH WILL MEAN SOME DEPOSITION ON ROADS WILL BE POSSIBLE SO
THE MENTION OF FREEZING FOG WAS INCLUDED.
TOMORROW AFTERNOON CLOUDS WILL THIN ALTHOUGH STILL HAVE MUCH OF THE
AREA WITH A SNOW PACK. THIS WILL LIMIT THE ABILITY TO WARM...WITH
TEMPS STRUGGLING TO REACH FREEZING. SOME PARTIAL SUN IS EXPECTED
ACROSS WESTERN NEBRASKA THANKS TO SOME WESTERLY DOWNSLOPING WINDS
WHICH IS WHERE FORECAST HIGHS ARE THE WARMEST.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 325 PM CST WED DEC 17 2014
MID RANGE...THURSDAY NIGHT THROUGH SATURDAY...THE MAIN
FORECAST CHALLENGES IN THE MID RANGE ARE THE THREAT FOR FREEZING
DRIZZLE THURSDAY NIGHT INTO FRIDAY MORNING...AS WELL AS CLOUD COVER
AND TEMPERATURES. FOR THURSDAY NIGHT...WITH THE EXCEPTION OF THE FAR
NORTHWESTERN CWA...LOW CLOUDS AND AN ARCTIC DRAPE WILL REMAIN
ENTRENCHED ACROSS THE BULK OF THE FORECAST AREA. BOTH THE NAM AND
GFS SOLNS THIS MORNING PER FCST SOUNDINGS ARE INDICATING A NICE
LAYER OF NEAR 100 PERCENT RH FROM THE SURFACE TO 1000 TO 1500FT AGL.
WITHIN THIS LAYER...WEAK VEERING OF THE WINDS ARE PRESENT ALONG WITH
SOME WEAK OMEGA AND TEMPERATURES RANGING FROM ZERO TO -5C IN THIS
MOIST LAYER. IN ADDITION...WARMING AND DRYING IS INDICATED PER
FORECAST SOUNDINGS ABOVE THE MOIST LAYER DURING THE PERIOD. ALL
TOLD...THIS IS A DECENT SETUP FOR FREEZING DRIZZLE AND HAVE
INTRODUCED IT IN THE GRIDS. DURING THE EVENING HOURS...WITH THE
EXCEPTION OF THE PANHANDLE COUNTIES AND FAR NORTHWEST...CONDS WILL
BE FAVORABLE FOR FZDZ. THIS AREA WILL SHRINK EAST INTO THE OVERNIGHT
HOURS AND MORNING PERIOD FOR FRIDAY. BY FRIDAY AFTERNOON...MOSTLY
CLEAR SKIES IN THE CENTRAL AND WEST...AND PARTLY CLOUDY SKIES IN THE
EAST ARE EXPECTED. THIS WILL ALLOW TEMPS TO REACH THE LOWER TO
MIDDLE 30S FRIDAY...EFFECTIVELY ENDING THE FREEZING DRIZZLE THREAT.
ON FRIDAY NIGHT AND SATURDAY...FORECAST SOUNDINGS OVER THE EASTERN
THIRD OF THE FORECAST AREA ARE INDICATIVE OF ANOTHER EPISODE OF
FREEZING DRIZZLE LATE FRIDAY NIGHT INTO SATURDAY MORNING. ATTM...THE
THREAT FOR FREEZING DRIZZLE IS INDICATED ONLY IN THE NAM SOLN AS THE
GFS IS MORE AGGRESSIVE IN PUSHING THE ARCTIC AIRMASS EAST FRIDAY
NIGHT. GIVEN THE MODEL DIFFERENCES...WILL HOLD OFF ON MENTION OF
FREEZING DRIZZLE ATTM. ON SATURDAY...AN UPPER LEVEL DISTURBANCE
ACROSS THE NRN TIER OF STATES...WILL FORCE WARMER AIR INTO THE
FORECAST AREA...FOLLOWED BY A WEAK COOL FRONT SATURDAY NIGHT. LIGHT
WESTERLY WINDS SATURDAY WILL PUSH HIGHS INTO THE LOWER 40S.
SUNDAY THROUGH WEDNESDAY...AS THE UPPER LEVEL SYSTEM PUSHES EAST
MONDAY AND MONDAY NIGHT...THERE WILL BE AN INCREASED THREAT FOR LIGHT
PRECIPITATION IN THE FAR NORTHEAST...ALONG WITH A THREAT FOR
PRECIPITATION ACROSS THE CENTRAL AND NORTHERN ROCKIES...WHICH WILL
BE ENHANCED BY A STRONG UPPER LEVEL JET STREAK. BEYOND MONDAY
NIGHT...A DRY AND COLDER FORECAST IS EXPECTED ACROSS WESTERN AND
NORTH CENTRAL NEBRASKA AS ARCTIC AIR PUSHES SOUTH TUESDAY INTO
WEDNESDAY. ATTM...THE BEST THREAT FOR SNOW WILL BE OFF TO THE WEST
OF THE FORECAST AREA...HOWEVER...WE WILL NEED TO MONITOR NEXT
THURSDAY INTO NEXT WEEKEND AS THE LATEST ECMWF SOLN DIGS A DEEP
TROUGH INTO THE INTERMOUNTAIN WEST BY DAY 10.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1200 AM CST WED DEC 17 2014
PREVAILING WIDESPREAD LOW STRATUS WITH A CHANCE FOR SOME PATCHY
FREEZING DRIZZLE AND/OR LIGHT SNOW ACROSS SOUTHWEST NEBRASKA THE
NEXT 24 HOURS. GENERALLY IFR OR BELOW CIGS ACROSS THE AREA TO
PERSIST THROUGH 18Z TOMORROW. A WEAK DISTURBANCE WILL LIFT ACROSS
KANSAS AND EASTERN NEBRASKA OVERNIGHT WITH SOME WEAK LIFT AND
LIGHT SNOW POSSIBLE ACROSS SOUTHWEST NEBRASKA. A DRY LAYER ABOVE
THE MOIST BOUNDARY LAYER MAY RESULT IN SOME PATCHY FREEZING
DRIZZLE INSTEAD OF LIGHT SNOW...ESPECIALLY ON THE NW SIDE OF THE
SIDE WHICH IS WHERE KLBF IS LIKELY TO END UP...AND WILL HAVE TO
BE MONITORED. IN ADDITION TO THE STRATUS...WILL SEE LOCAL AREAS OF
FOG WITH VISIBILITIES AT TIMES DOWN TO 3SM OR LESS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...MASEK/JWS
LONG TERM...CLB
AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
250 PM PST WED DEC 17 2014
.SYNOPSIS...SCATTERED LIGHT RAIN SHOWERS AND MOUNTAIN SNOW SHOWERS
WILL DIMINISH OVERNIGHT AS A WEATHER SYSTEM SLOWLY MOVES ACROSS THE
DESERT SOUTHWEST. IMPROVING CONDITIONS ARE EXPECTED THURSDAY AND
FRIDAY. A FEW SHOWERS WILL BE POSSIBLE ACROSS THE GREAT BASIN OVER
THE WEEKEND FOLLOWED BY DRY AND WARMER WEATHER NEXT WEEK.
&&
.SHORT TERM...EXTENSIVE LOW TO MID LEVEL CLOUDS WERE APPARENT FROM
SATELLITE LOOPS AND SURFACE OBSERVATIONS ACROSS THE FORECAST AREA
AND THESE WILL BE SLOW TO CLEAR OUT TONIGHT THROUGH THURSDAY. RECENT
RADAR LOOPS SHOWED A SLIGHT UPWARD TREND IN SCATTERED SHOWERS ACROSS
SOUTHERN CLARK AND CENTRAL MOHAVE COUNTIES EARLY THIS AFTERNOON AND
THE HRRR MODEL INDICATES THIS WILL BE THE PRIMARY AREA FOR
PRECIPITATION THROUGH EARLY THIS EVENING. ANY ADDITIONAL SNOW
AMOUNTS IN THE MOUNTAINS OF SOUTHERN NEVADA AND NORTHWEST ARIZONA
ARE EXPECTED TO BE VERY LIGHT AND THE WINTER WEATHER ADVISORY HAS
BEEN CANCELLED. THE MEAN TROUGH OVER THE REGION WILL DIG A
LITTLE TONIGHT AS A SHORTWAVE WEST OF POINT CONCEPTION DIVES TOWARD
NORTHERN BAJA. AN ADDITIONAL BAND OF MOISTURE ASSOCIATED WITH THIS
SHORTWAVE WILL MOVE INTO THE SOUTHERN SIERRA OVERNIGHT AND WILL
PRODUCE A CHANCE OF VERY LIGHT SNOW OVER THE EASTERN SLOPES...SO
POPS WERE INCREASED ACCORDINGLY.
THE TROUGH AXIS WILL SHIFT EASTWARD THURSDAY WITH GRADUAL CLEARING
THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. LITTLE CHANGE IN
TEMPERATURES CAN BE EXPECTED.
&&
.LONG TERM...FRIDAY THROUGH TUESDAY.
MEDIUM RANGE MODELS SIMILAR TO 24 HOURS AGO INDICATING MOST OF THE
ENERGY ASSOCIATED WITH NEXT SHORTWAVE TROUGH WILL AFFECT CENTRAL
NEVADA NORTHWARD FRIDAY NIGHT INTO SATURDAY. WITH THAT SAID, LEFT IN
SLIGHT CHANCE POPS FROM NORTHERN INYO COUNTY EASTWARD TO NORTHERN
LINCOLN COUNTY TO ACCOUNT FOR ANY POTENTIAL SOUTHWARD SHIFT.
SUNDAY THROUGH TUESDAY THE LONGWAVE PATTERN WILL BE DOMINATED BY A
STRONG RIDGE ALONG THE WEST COAST WITH A TROUGH EAST OF THE ROCKIES.
SOUTHERN GREAT BASIN/MOJAVE DESERT WILL LIE UNDER A DRY NORTHWEST
FLOW. SURFACE HIGH DEVELOPING OVER THE NORTHERN GREAT BASIN WILL
LEAD TO AN INCREASE IN NORTH BREEZES DOWN THE COLORADO RIVER VALLEY
SOUTH OF HOOVER DAM SUNDAY-TUESDAY.
&&
.AVIATION...FOR MCCARRAN...CEILINGS BETWEEN 3K-6K FEET AROUND WILL
PERSIST THROUGH EARLY EVENING THEN HOVER AROUND 6 KFT BEFORE
PARTIALLY CLEARING AND LIFTING TO AROUND 10 KFT THURSDAY MORNING.
GENERALLY LIGHTS WINDS WILL CONTINUE TONIGHT.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...CEILINGS OF 3K-5K FT AND MOUNTAIN OBSCURATION WILL
CONTINUE ACROSS MUCH OF THE REGION TONIGHT THROUGH THURSDAY MORNING
FOLLOWED BY PARTIAL CLEARING AS A WEAK WEATHER SYSTEM GRADUALLY
MOVES TO THE EAST.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS TODAY THROUGH THURSDAY ACCORDING
TO STANDARD OPERATING PROCEDURES.
&&
$$
SHORT TERM/AVIATION...ADAIR
LONG TERM...PIERCE
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1049 AM MST WED DEC 17 2014
.AVIATION...
18Z TAF CYCLE
ATMOSPHERIC MOISTURE HAS INCREASED SIGNIFICANTLY IN ADVANCE OF TWO
UPPER LEVEL DISTURBANCES AND IS RESULTING IN AREAS OF SNOW...
OCCASIONAL IFR CONDITIONS AND WIDESPREAD MOUNTAIN OBSCURATIONS.
IMPROVEMENT ALREADY OBSERVED THOUGH...WITH TERMINALS IMPACTED
EARLIER TRENDING UP INTO MVFR AND VFR CATEGORIES. CONDITIONS
SHOULD DETERIORATE THIS EVENING...ESPECIALLY AT KGUP WITH THE
ONSET OF ANOTHER ROUND OF SNOW. ELSEWHERE ACROSS CENTRAL AND
WESTERN PORTIONS OF THE AREA...MVFR IMPACTS ARE POSSIBLE...MOST
LIKELY AT KSAF. KROW AND KLVS LOOK TO REMAIN VFR THROUGH THE NEXT
24HRS...WHILE IFR CONDITIONS ARE POSSIBLE THURSDAY MORNING AT KTCC
WITH THE PASSAGE OF A WEAK BACKDOOR COLD FRONT.
11
&&
.UPDATE...
UPDATED FORECAST TO INCLUDE SANTA FE METRO AND THE LOWER CHAMA
RIVER VALLEY INCLUDING ESPANOLA TO THE WINTER WEATHER ADVISORY
THROUGH THIS EVENING. VALLEY AREAS IN AND AROUND ESPANOLA RADIATIVELY
COOLED LAST NIGHT SO SNOW LEVELS ARE LOWER THERE. ALSO RAISED
PRECIPITATION CHANCES FROM EASTERN CIBOLA COUNTY EAST AND
NORTHEASTWARD TO CENTRAL SANGRE DE CRISTOS UNDERNEATH AND ON THE
BACKSIDE OF THE MAIN VORT CENTER/CIRCULATION.
33
&&
.PREV DISCUSSION...312 AM MST WED DEC 17 2014...
.SYNOPSIS...
SEVERAL UPPER LEVEL DISTURBANCES TODAY AND THURSDAY WILL BRING
MUCH NEEDED PRECIPITATION TO THE LAND OF ENCHANTMENT. MUCH OF THE
PRECIPITATION WILL FAVOR WESTERN...AND PERHAPS TO SOME
EXTENT...CENTRAL NEW MEXICO. 1 TO 3 INCH SNOW AMOUNTS WILL BE
COMMON ABOVE 6000 FEET...WITH 3 TO 5 INCHES ACROSS THE HIGHER
TERRAIN. AFTER THE LAST SYSTEM EXITS THE STATE THURSDAY NIGHT...A
MUCH QUIETER FRIDAY WILL PREVAIL...BUT TEMPERATURES WILL REMAIN
CHILLY. MODELS ARE BACKING OFF ON PRECIPITATION POTENTIAL THIS
WEEKEND AND EARLY NEXT WEEK...BUT THERE IS STILL PLENTY OF TIME
FOR THAT TO CHANGE.
&&
.DISCUSSION...
AFTER MANY DIFFERENT DEPICTIONS OF TODAYS EVENT BY THE MODELS
OVER THE LAST FEW DAYS...IT APPEARS THAT THEY HAVE FINALLY COME
INTO AGREEMENT. TWO QUICK MOVING SHORTWAVE TROUGHS WILL CROSS NM
TODAY...BOTH CURRENTLY WELL DEFINED ON WATER VAPOR IMAGERY. THE
FIRST IS ASSOCIATED WITH THE LIGHTNING ACROSS NORTHERN MEXICO THIS
MORNING...WHILE THE SECOND IS ASSOCIATED WITH THE LIGHTNING OFF
THE COAST OF CALI. SHOWERS ARE ALREADY DEVELOPING AHEAD OF THE
FIRST SYSTEM IN ARIZONA AND TO SOME EXTENT WESTERN NM. THIS SYSTEM
LOOKS TO CROSS NM THIS MORNING AND EARLY THIS AFTERNOON. MOST
OPERATIONAL MODELS SHOW THE FAVORED AREA OF PRECIPITATION ACROSS
THE NW QUARTER OF NM. TEMPS ARE COLD ENOUGH FOR SOME SNOW EVEN
ACROSS THE NW PLATEAU...THUS A GOOD CALL BY THE EVENING CREW TO
ADD ZONE 501 TO THE WINTER WX ADVY. THE SECOND DISTURBANCE WILL
COME QUICKLY AFTER THE FIRST AND CROSS NM LATE THIS AFTN AND THIS
EVE. SNOW LEVELS THIS AFTN WILL RANGE FROM 5500-6000 FEET OR SO.
WHILE THE FIRST SYSTEM MAY BRING A MORE SOLID AREA OF SNOW...THE
PRECIPITATION WITH THE SECOND SYSTEM LOOKS TO BE MORE CONVECTIVE
IN NATURE...AND MAY EVEN SEE SOME ISOLATED THUNDERSTORMS THIS
AFTERNOON. AREAS ALONG AND WEST OF THE RIO GRANDE WILL GENERALLY
BE FAVORED FOR PRECIPITATION.ONE INTERESTING NOTE...HOWEVER...IS
THAT THE HRRR HAS TRENDED BACK ON PRECIPITATION OVER THE LAST
SEVERAL RUNS...AT LEAST WITH PRECIPITATION THROUGH EARLY AFTN.
WITH ALL THAT SAID...THE WINTER WX ADVYS LOOK PRETTY GOOD...THOUGH
SNOW AMOUNTS WILL CERTAINLY BE ON THE LIGHTER SIDE OF ADVISORY
CRITERIA FOR MOST AREAS.
A THIRD SHORTWAVE WILL ARRIVE ON THURSDAY...THOUGH MOST OF THE
ENERGY ASSOCIATED WITH THIS SYSTEM WILL DIVE SOUTH OF THE CWA. SOME
LIGHT SHOWERY ACTIVITY SHOULD OCCUR ACROSS THE WEST AGAIN...BUT
AMOUNTS WILL BE MINIMAL. THE SOUTHERN TIER OF THE CWA...FROM THE
SOUTHWEST MTNS TO ROOSEVELT COUNTY...WILL HAVE THE BEST CHANCES FOR
PRECIPITATION...BUT EVEN THEN...AMOUNTS WILL BE MINIMAL. COLD TEMPS
WILL KEEP SNOW LEVELS LOW...GENERALLY AOB 5500 FEET.
AFTER THE THIRD SYSTEM SLIDES EAST THURSDAY NIGHT...FRIDAY SHOULD BE
QUIET...THOUGH STILL CHILLY. MODELS ARE SHOWING A TROUGH CROSSING NM
ON SATURDAY...BUT LITTLE MOISTURE IS ASSOCIATED WITH IT SO NOT
EXPECTING PRECIP ATTM. THEREAFTER...STRONG NORTHWEST FLOW LOOKS TO
BE THE RULE. THE ECMWF IS SHOWING A DISTURBANCE WITHIN THE FLOW MAY
CLIP NE NM ON MONDAY AND MONDAY NIGHT. THIS COMBINED WITH AN
ASSOCIATED COLD FRONT MAY RESULT IN SOME LIGHT SHOWERS ACROSS THE
NORTHEAST IF THE ECMWF IS CORRECT. OTHERWISE...DRIER CONDITIONS
LOOK TO BE THE RULE THROUGH AT LEAST MID WEEK.
34
&&
.FIRE WEATHER...
MAIN FIRE WEATHER HIGHLIGHTS INCLUDE AN UNSETTLED WEATHER PATTERN
WITH SOME CHANCES OF WETTING MOISTURE ACROSS WESTERN/CENTRAL AREAS
THROUGH THURSDAY MORNING. THE WEEKEND SYSTEM JUST LOOKS TOO DRY.
GUSTIER NW WINDS AND DECENT VENTILATION IN AREAS EXPECTED SUNDAY
THROUGH EARLY NEXT WEEK.
CURRENT RADAR TRENDS SHOW SHOWER DEVELOPMENT AND SOME ORGANIZATION
IN THE PRECIPITATION FIELD OVER ARIZONA. SNOW AND LOWER ELEVATION
RAIN SHOWERS WILL SPREAD ACROSS THE WESTERN HALF OF THE AREA THROUGH
THE DAY PERIOD WITH LINGERING IMPACTS INTO THE OVERNIGHT. OROGRAPHIC
WEST FACING SLOPES LOOK TO BE FAVORED WITH THE WETTING
PRECIPITATION. EASTERN AREAS WILL SEE SCANT PRECIPITATION RESULTS.
TEMPERATURES WILL BE COOLER THAN NORMAL WITH HIGH RH VALUES FAVORING
THE WESTERN HALF. FLOW ALOFT WILL INCREASE AND WILL COMBINE WITH
RISING MIXING HEIGHTS TO PRODUCE IMPROVING VENTILATION MOST AREAS.
THE SOUTHERN HALF WILL BE THE FOCUS FOR GOOD TO EXCELLENT RATINGS.
SURFACE WINDS WILL BE BREEZY AT TIMES ACROSS THE SOUTHERN
HALF...ESPECIALLY OVER THE MOUNTAIN RIDGES/PEAKS.
A SECONDARY PACIFIC WAVE OR TROUGH WILL SLIDE OVER THE REGION ON
THURSDAY. MODELS HAVE BEEN TAKING THE MAIN PIECE OF ENERGY
ASSOCIATED WITH THE TROUGH FURTHER SOUTH SO IMPACTS TO THE FIRE WX
AREA LOOK TO BE MINIMAL AT THIS TIME. PERHAPS SOME LOCALIZED WETTING
MOISTURE ACROSS THE FAR SOUTH. EITHER WAY...HIGH TEMPERATURES WILL
REMAIN BELOW NORMAL MOST AREAS WITH HIGHER HUMIDITY READINGS. MIXING
HEIGHTS APPEAR TO BE NEAR SEASONABLE IF NOT A LITTLE HIGHER THAN
NORMAL ALTHOUGH TRANSPORT WINDS WILL LOWER COMPARED TO TODAY/S
VALUES. THUS...VENT RATES WILL LOWER. LOOKING AT A STRIP OF FAIR
CONDITIONS BETWEEN FARMINGTON TO THE ESTANCIA VALLEY BUT WOULD ONLY
BE FAIR FOR 2 TO 4 HRS MOST LOCATIONS.
AS MENTIONED ABOVE...STORM SYSTEM FOR THE WEEKEND PERIOD LOOKS TO BE
A NON EVENT. THERE WILL BE A PACIFIC WAVE CAUGHT IN NW FLOW MOVING
OVER THE AREA SATURDAY NIGHT. STRENGTHENING NW FLOW WILL BE FOUND ON
THE BACKSIDE OF THE WAVE AND PROVIDE SOME BREEZES ON SUNDAY.
ESPECIALLY IMPACTING THE MT TAYLOR TO CLINES CORNER AREA. SURFACE
WINDS ON SATURDAY APPEAR TO BE LIGHT. VENTILATION RATES ON SATURDAY
LOOK TO BE ON THE LOWER SIDE WITH SOME FAIR TO GOOD CONDITIONS
GENERALLY LASTING A FEW HRS.
MODELS CONTINUE TO SHOW A GUSTIER NW FLOW DEVELOPING OVER THE AREA
DURING THE EARLIER HALF OF NEXT WEEK. VENTILATION RATES SHOULD
IMPROVE IN AREAS DUE TO THE HIGHER TRANSPORT WINDS BUT LOWER MIXING
HEIGHTS WILL PRESENT SOME OF THE AREA FROM GETTING INTO THE
FAIR/GOOD TO EXCELLENT READINGS. SUSPECT VENT RATE VALUES WILL
ADJUST SOME AS THE FLOW ADJUSTS. THE FLOW DOES LOOK TO BE DRIER WITH
TEMPERATURES BECOMING A BIT WARMER. THE GFS IS DRY BUT THE ECMWF IS
STILL SPITTING OUT LIGHTER PRECIPITATION AMOUNTS ACROSS THE EAST ON
TUESDAY. WOULD LIKE TO SEE ANOTHER DAY OR TWO WORTH OF CONSISTENT
MODEL RUNS BEFORE TOTALLY BUYING OFF ON THIS SCENARIO.
50
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR THE
FOLLOWING ZONES...NMZ501>508-510>514-517-518.
&&
$$
33
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
943 AM MST WED DEC 17 2014
.UPDATE...
UPDATED FORECAST TO INCLUDE SANTA FE METRO AND THE LOWER CHAMA
RIVER VALLEY INCLUDING ESPANOLA TO THE WINTER WEATHER ADVISORY
THROUGH THIS EVENING. VALLEY AREAS IN AND AROUND ESPANOLA RADIATIVELY
COOLED LAST NIGHT SO SNOW LEVELS ARE LOWER THERE. ALSO RAISED
PRECIPITATION CHANCES FROM EASTERN CIBOLA COUNTY EAST AND
NORTHEASTWARD TO CENTRAL SANGRE DE CRISTOS UNDERNEATH AND ON THE
BACKSIDE OF THE MAIN VORT CENTER/CIRCULATION.
33
&&
.PREV DISCUSSION...449 AM MST WED DEC 17 2014...
.AVIATION...
12Z TAF CYCLE
PACIFIC MOISTURE WILL CONTINUE TO STREAM OVER THE AREA DURING THE
NEXT 12 TO 24 HRS. CONDITIONS WILL DETERIORATE DURING THE MORNING
AND AFTERNOON HOURS TODAY BUT IMPROVE DURING THE OVERNIGHT. LOOK
FOR WIDESPREAD MVFR CATEGORIES ASSOCIATED WITH RAIN/SNOW. THE
HIGHER ELEVATION TERMINAL SITES SUCH AS GUP/SAF SHOULD SEE
PREDOMINATE SN WHILE OTHER SITES LIKE FMN/AEG/ABQ COULD SEE A MIX.
LOCALIZED IFR CONDITIONS EXPECTED WITH THE PRECIPITATION. AS THE
SH DIE OFF TONIGHT...SOME OF THE TERMINAL SITES COULD EXPERIENCE
REDEVELOPMENT OF LOWER CIG/VIS. THIS IS MOST LIKELY TO OCCUR AT
FMN/GUP.
50
&&
.PREV DISCUSSION...312 AM MST WED DEC 17 2014...
.SYNOPSIS...
SEVERAL UPPER LEVEL DISTURBANCES TODAY AND THURSDAY WILL BRING
MUCH NEEDED PRECIPITATION TO THE LAND OF ENCHANTMENT. MUCH OF THE
PRECIPITATION WILL FAVOR WESTERN...AND PERHAPS TO SOME
EXTENT...CENTRAL NEW MEXICO. 1 TO 3 INCH SNOW AMOUNTS WILL BE
COMMON ABOVE 6000 FEET...WITH 3 TO 5 INCHES ACROSS THE HIGHER
TERRAIN. AFTER THE LAST SYSTEM EXITS THE STATE THURSDAY NIGHT...A
MUCH QUIETER FRIDAY WILL PREVAIL...BUT TEMPERATURES WILL REMAIN
CHILLY. MODELS ARE BACKING OFF ON PRECIPITATION POTENTIAL THIS
WEEKEND AND EARLY NEXT WEEK...BUT THERE IS STILL PLENTY OF TIME
FOR THAT TO CHANGE.
&&
.DISCUSSION...
AFTER MANY DIFFERENT DEPICTIONS OF TODAYS EVENT BY THE MODELS
OVER THE LAST FEW DAYS...IT APPEARS THAT THEY HAVE FINALLY COME
INTO AGREEMENT. TWO QUICK MOVING SHORTWAVE TROUGHS WILL CROSS NM
TODAY...BOTH CURRENTLY WELL DEFINED ON WATER VAPOR IMAGERY. THE
FIRST IS ASSOCIATED WITH THE LIGHTNING ACROSS NORTHERN MEXICO THIS
MORNING...WHILE THE SECOND IS ASSOCIATED WITH THE LIGHTNING OFF
THE COAST OF CALI. SHOWERS ARE ALREADY DEVELOPING AHEAD OF THE
FIRST SYSTEM IN ARIZONA AND TO SOME EXTENT WESTERN NM. THIS SYSTEM
LOOKS TO CROSS NM THIS MORNING AND EARLY THIS AFTERNOON. MOST
OPERATIONAL MODELS SHOW THE FAVORED AREA OF PRECIPITATION ACROSS
THE NW QUARTER OF NM. TEMPS ARE COLD ENOUGH FOR SOME SNOW EVEN
ACROSS THE NW PLATEAU...THUS A GOOD CALL BY THE EVENING CREW TO
ADD ZONE 501 TO THE WINTER WX ADVY. THE SECOND DISTURBANCE WILL
COME QUICKLY AFTER THE FIRST AND CROSS NM LATE THIS AFTN AND THIS
EVE. SNOW LEVELS THIS AFTN WILL RANGE FROM 5500-6000 FEET OR SO.
WHILE THE FIRST SYSTEM MAY BRING A MORE SOLID AREA OF SNOW...THE
PRECIPITATION WITH THE SECOND SYSTEM LOOKS TO BE MORE CONVECTIVE
IN NATURE...AND MAY EVEN SEE SOME ISOLATED THUNDERSTORMS THIS
AFTERNOON. AREAS ALONG AND WEST OF THE RIO GRANDE WILL GENERALLY
BE FAVORED FOR PRECIPITATION.ONE INTERESTING NOTE...HOWEVER...IS
THAT THE HRRR HAS TRENDED BACK ON PRECIPITATION OVER THE LAST
SEVERAL RUNS...AT LEAST WITH PRECIPITATION THROUGH EARLY AFTN.
WITH ALL THAT SAID...THE WINTER WX ADVYS LOOK PRETTY GOOD...THOUGH
SNOW AMOUNTS WILL CERTAINLY BE ON THE LIGHTER SIDE OF ADVISORY
CRITERIA FOR MOST AREAS.
A THIRD SHORTWAVE WILL ARRIVE ON THURSDAY...THOUGH MOST OF THE
ENERGY ASSOCIATED WITH THIS SYSTEM WILL DIVE SOUTH OF THE CWA. SOME
LIGHT SHOWERY ACTIVITY SHOULD OCCUR ACROSS THE WEST AGAIN...BUT
AMOUNTS WILL BE MINIMAL. THE SOUTHERN TIER OF THE CWA...FROM THE
SOUTHWEST MTNS TO ROOSEVELT COUNTY...WILL HAVE THE BEST CHANCES FOR
PRECIPITATION...BUT EVEN THEN...AMOUNTS WILL BE MINIMAL. COLD TEMPS
WILL KEEP SNOW LEVELS LOW...GENERALLY AOB 5500 FEET.
AFTER THE THIRD SYSTEM SLIDES EAST THURSDAY NIGHT...FRIDAY SHOULD BE
QUIET...THOUGH STILL CHILLY. MODELS ARE SHOWING A TROUGH CROSSING NM
ON SATURDAY...BUT LITTLE MOISTURE IS ASSOCIATED WITH IT SO NOT
EXPECTING PRECIP ATTM. THEREAFTER...STRONG NORTHWEST FLOW LOOKS TO
BE THE RULE. THE ECMWF IS SHOWING A DISTURBANCE WITHIN THE FLOW MAY
CLIP NE NM ON MONDAY AND MONDAY NIGHT. THIS COMBINED WITH AN
ASSOCIATED COLD FRONT MAY RESULT IN SOME LIGHT SHOWERS ACROSS THE
NORTHEAST IF THE ECMWF IS CORRECT. OTHERWISE...DRIER CONDITIONS
LOOK TO BE THE RULE THROUGH AT LEAST MID WEEK.
34
&&
.FIRE WEATHER...
MAIN FIRE WEATHER HIGHLIGHTS INCLUDE AN UNSETTLED WEATHER PATTERN
WITH SOME CHANCES OF WETTING MOISTURE ACROSS WESTERN/CENTRAL AREAS
THROUGH THURSDAY MORNING. THE WEEKEND SYSTEM JUST LOOKS TOO DRY.
GUSTIER NW WINDS AND DECENT VENTILATION IN AREAS EXPECTED SUNDAY
THROUGH EARLY NEXT WEEK.
CURRENT RADAR TRENDS SHOW SHOWER DEVELOPMENT AND SOME ORGANIZATION
IN THE PRECIPITATION FIELD OVER ARIZONA. SNOW AND LOWER ELEVATION
RAIN SHOWERS WILL SPREAD ACROSS THE WESTERN HALF OF THE AREA THROUGH
THE DAY PERIOD WITH LINGERING IMPACTS INTO THE OVERNIGHT. OROGRAPHIC
WEST FACING SLOPES LOOK TO BE FAVORED WITH THE WETTING
PRECIPITATION. EASTERN AREAS WILL SEE SCANT PRECIPITATION RESULTS.
TEMPERATURES WILL BE COOLER THAN NORMAL WITH HIGH RH VALUES FAVORING
THE WESTERN HALF. FLOW ALOFT WILL INCREASE AND WILL COMBINE WITH
RISING MIXING HEIGHTS TO PRODUCE IMPROVING VENTILATION MOST AREAS.
THE SOUTHERN HALF WILL BE THE FOCUS FOR GOOD TO EXCELLENT RATINGS.
SURFACE WINDS WILL BE BREEZY AT TIMES ACROSS THE SOUTHERN
HALF...ESPECIALLY OVER THE MOUNTAIN RIDGES/PEAKS.
A SECONDARY PACIFIC WAVE OR TROUGH WILL SLIDE OVER THE REGION ON
THURSDAY. MODELS HAVE BEEN TAKING THE MAIN PIECE OF ENERGY
ASSOCIATED WITH THE TROUGH FURTHER SOUTH SO IMPACTS TO THE FIRE WX
AREA LOOK TO BE MINIMAL AT THIS TIME. PERHAPS SOME LOCALIZED WETTING
MOISTURE ACROSS THE FAR SOUTH. EITHER WAY...HIGH TEMPERATURES WILL
REMAIN BELOW NORMAL MOST AREAS WITH HIGHER HUMIDITY READINGS. MIXING
HEIGHTS APPEAR TO BE NEAR SEASONABLE IF NOT A LITTLE HIGHER THAN
NORMAL ALTHOUGH TRANSPORT WINDS WILL LOWER COMPARED TO TODAY/S
VALUES. THUS...VENT RATES WILL LOWER. LOOKING AT A STRIP OF FAIR
CONDITIONS BETWEEN FARMINGTON TO THE ESTANCIA VALLEY BUT WOULD ONLY
BE FAIR FOR 2 TO 4 HRS MOST LOCATIONS.
AS MENTIONED ABOVE...STORM SYSTEM FOR THE WEEKEND PERIOD LOOKS TO BE
A NON EVENT. THERE WILL BE A PACIFIC WAVE CAUGHT IN NW FLOW MOVING
OVER THE AREA SATURDAY NIGHT. STRENGTHENING NW FLOW WILL BE FOUND ON
THE BACKSIDE OF THE WAVE AND PROVIDE SOME BREEZES ON SUNDAY.
ESPECIALLY IMPACTING THE MT TAYLOR TO CLINES CORNER AREA. SURFACE
WINDS ON SATURDAY APPEAR TO BE LIGHT. VENTILATION RATES ON SATURDAY
LOOK TO BE ON THE LOWER SIDE WITH SOME FAIR TO GOOD CONDITIONS
GENERALLY LASTING A FEW HRS.
MODELS CONTINUE TO SHOW A GUSTIER NW FLOW DEVELOPING OVER THE AREA
DURING THE EARLIER HALF OF NEXT WEEK. VENTILATION RATES SHOULD
IMPROVE IN AREAS DUE TO THE HIGHER TRANSPORT WINDS BUT LOWER MIXING
HEIGHTS WILL PRESENT SOME OF THE AREA FROM GETTING INTO THE
FAIR/GOOD TO EXCELLENT READINGS. SUSPECT VENT RATE VALUES WILL
ADJUST SOME AS THE FLOW ADJUSTS. THE FLOW DOES LOOK TO BE DRIER WITH
TEMPERATURES BECOMING A BIT WARMER. THE GFS IS DRY BUT THE ECMWF IS
STILL SPITTING OUT LIGHTER PRECIPITATION AMOUNTS ACROSS THE EAST ON
TUESDAY. WOULD LIKE TO SEE ANOTHER DAY OR TWO WORTH OF CONSISTENT
MODEL RUNS BEFORE TOTALLY BUYING OFF ON THIS SCENARIO.
50
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR THE
FOLLOWING ZONES...NMZ501>508-510>514-517-518.
&&
$$
33
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
445 PM EST WED DEC 17 2014
.SYNOPSIS...
AN UPPER LEVEL STORM SYSTEM MOVING FROM THE GREAT LAKES TO NEW
ENGLAND WILL RESULT IN RAIN SHOWERS CHANGING TO SNOW SHOWERS
ACROSS NEW YORK STATE LATE TODAY WITH SCATTERED SNOW SHOWERS
CONTINUING TONIGHT INTO THURSDAY. FARTHER SOUTH A FEW SPRINKLES
AND FLURRIES CAN BE EXPECTED IN NORTHEAST PENNSYLVANIA. CLOUDS AND
SEASONABLY COLD TEMPERATURES WILL PERSIST FRIDAY INTO THE WEEKEND
WITH SCATTERED SNOW SHOWERS GRADUALLY DIMINISHING.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
A BAND OF STEADY LIGHT RAIN IS MOVING EAST ACROSS CENTRAL NY THIS
AFTERNOON WITH A CHANGE-OVER TO LIGHT SNOW ALREADY OCCURRING OVER
THE HIGHER ELEVATIONS AS OF 3 PM. THIS BAND WILL LIFT EAST-
NORTHEAST TOWARD THE CATSKILLS AND MOHAWK VALLEY THROUGH LATE THIS
AFTERNOON WITH LOWER ELEVATIONS GRADUALLY MIXING WITH OR CHANGING
TO LIGHT SNOW AS COLDER AIR FILTERS IN FROM THE WEST. MEANWHILE...
MAINLY DRY WEATHER CAN BE EXPECTED TO CONTINUE IN THE WILKES-BARRE
AND SCRANTON AREAS AND POINTS SOUTH WITH PRECIPTIATION REMAINING
TO THE NORTH.
PRECIPITATION SHOULD BECOME SPOTTIER AND LIGHTER EARLY THIS
EVENING IN MANY AREAS... THEN UPPER LEVEL LOW PRESSURE CURRENTLY
OVER WESTERN MICHIGAN WILL TRACK RAPIDLY EAST ACROSS THE AREA
LATER TONIGHT. THIS COULD RESULT IN A PERIOD OF ENHANCED SNOW
SHOWERS AGAIN LATE TONIGHT INTO EARLY THURSDAY MORNING. A BIT OF
LAKE ENHNACEMENT COULD ALSO OCCUR SOUTHEAST OF LAKE ONTARIO LATE
TONIGHT AS 850 MB TEMPERATURES FALL TO AROUND -8 C. LATEST HIGH
RESOLUTION NAM AND HRRR BOTH SUPPORT THE IDEA THAT SNOW SHOWERS
MAY INCREASE IN COVERAGE LATE TONIGHT WITH THE PASSAGE OF THIS
SYSTEM. BASED ON THIS HAVE UPPED POPS INTO THE LIKELY CATEGORY
LATER TONIGHT AND HAVE UP TO AN INCH OF SNOW POSSIBLE ESPECIALLY
AT HIGHER ELEVATIONS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
UPPER LEVEL AND SURFACE LOW PRESSURE WILL TRACK SLOWLY EAST ACROSS
THE SOUTHERN CANADIAN MARITIMES THURSDAY THROUGH FRIDAY. FLOW
ACROSS OUR AREA IN THE WAKE OF THIS SYSTEM WILL BE NORTHWESTERLY WITH
PLENTY OF LOW-LEVEL MOISTURE AND 850 MB TEMPERATURES HOLDING
AROUND -8 TO -10 C... WHICH WILL BE JUST COLD ENOUGH FOR A MINOR
LAKE RESPONSE IN THE NORTHWEST FLOW. HOWEVER MOISTURE WILL BECOME
INCREASINGLY SHALLOW WITH CONSIDERABLE DRYING IN THE -10 TO -20
DEGREE SNOW GROWTH ZONE BY THURSDAY AFTERNOON. BASED ON THIS
EXPECT JUST SCATTERED LIGHT SNOW SHOWERS THURSDAY AFTERNOON INTO
FRIDAY WITH ONLY MINIMAL ACCUMULATIONS. SOME FREEZING DRIZZLE
MIGHT EVEN OCCUR THURSDAY NIGHT ALTHOUGH AT THIS POINT I THINK
THAT IS A LOW PROBABILITY SCENARIO AND I HAVE NOT INCLUDED ZL IN
THE GRIDDED FORECAST. AT THIS POINT IT APPEARS THAT CLOUDS WILL
PERSIST THROUGH FRIDAY. WITH PLENTY OF CLOUDS WE ARE NOT EXPECTING
MUCH DIURNAL VARIATION IN TEMPERATURES THROUGH FRIDAY WITH HIGHS
MAINLY 30 TO 35 AND LOWS 20 TO 25 IN MOST PLACES.
BEST CHANCE TO SEE ANY SUNSHINE MIGHT BE EARLY SATURDAY BEFORE
CLOUDS AHEAD OF THE NEXT SYSTEM STREAM NORTHEAST ACROSS THE AREA
DURNIG THE AFTERNOON. SATURDAY SHOULD BE DRY WITH TEMPERATURES
AGAIN MAINLY IN THE 30S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
1 PM UPDATE..
FOLLOWED WPC GUIDANCE FOR THE MOST PART. SAT NGT AND SUN SOME
LIGHT SNOW WITH AN INVERTED TROF FROM A COASTAL STORM WELL OUT TO
SEA. SNOW ACCUMULATIONS WILL BE MOSTLY 2 INCHES OR LESS.
DRY SUN NGT AND MON WITH A MILD SFC HIGH. MON NGT AND TUE MODELS
NOW TRYING TO BRING A WEAK COASTAL STORM NE INTO THE AREA WITH
MIXED PRECIP. ADDED SOME LOW CHC POPS.
WED A STRONG OCCLUDED FRONT LIFTS NE AHEAD OF A LARGE BOMBING
STACKED LOW IN THE MIDWEST. WARM AIR SO PRECIP MOSTLY RAIN. THIS
WILL NEED TO BE WATCHED FIRST FOR RAIN AMOUNTS AND POSSIBLY
FLOODING AND SECOND FOR STRONG GUSTY WINDS.
ON THE TAIL END OF THE STEADY RAIN IT WILL CHANGE OVER TO SNOW WED
NGT AND STAY COLD THE REST OF THE WEEK WITH WRAP AROUND SNOW.
&&
.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
1230 PM UPDATE...
MAINLY MVFR CIGS AND VFR VSBYS NEXT 24 HOURS.
CAA WITH NW FLOW SETTING UP CHANGING RAIN SHOWERS TO SNOW. GETTING
ON THE BACK SIDE OF AN UPPER LEVEL LOW WHILE THE SFC LOW IS WELL
NE NEAR OTTAWA. PRECIP STILL IN NY BUT LIFTING NORTH SO THAT ONLY
SYR AND RME WILL HAVE SNOW SHOWERS AND FLURRIES TONIGHT. THIS WILL
KEEP CIGS MVFR AND POSSIBLY VSBY IN HEAVIER SNOW SHOWERS.
ELM WILL FALL TO MVFR CIGS AND BE MAINLY DRY. IMPROVEMENT THU MORN
TO VFR. BGM NOW HAS IFR CIGS BUT THAT SHOULD LIFT TO LOW MVFR LATE
TODAY AS THE STEADIER PRECIP LIFTS NORTH. ITH LOW MVFR NOW AND
TONIGHT. ITH AND BGM IMPROVE TO HIGHER MVFR THU MORN.
AVP SHOULD BE MOSTLY VFR AND DRY.
WEST WINDS AT 10 KTS WITH SOME SPORADIC GUSTS THIS AFTN. W TO NW
WINDS TONIGHT AT 10 KTS THEN THU 10 TO 15 KTS WITH HIGHER GUSTS.
OUTLOOK...
THUR AFTN TO FRI... MAINLY VFR. MVFR/IFR RESTRICTIONS ARE PSBL AT
KRME/KSYR/KITH/KBGM DUE TO CIGS AND AT TIMES WITH -SHSN.
FRI NGT TO SAT...VFR.
SAT NGT AND SUN...MVFR/IFR IN LIGHT SNOW.
SUN NGT AND MON...VFR/MVFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE
NEAR TERM...MSE
SHORT TERM...MSE
LONG TERM...TAC
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
315 PM EST WED DEC 17 2014
.SYNOPSIS...
AN UPPER LEVEL STORM SYSTEM MOVING FROM THE GREAT LAKES TO NEW
ENGLAND WILL RESULT IN RAIN SHOWERS CHANGING TO SNOW SHOWERS
ACROSS NEW YORK STATE LATE TODAY WITH SCATTERED SNOW SHOWERS
CONTINUING TONIGHT INTO THURSDAY. FARTHER SOUTH A FEW SPRINKLES
AND FLURRIES CAN BE EXPECTED IN NORTHEAST PENNSYLVANIA. CLOUDS AND
SEASONABLY COLD TEMPERATURES WILL PERSIST FRIDAY INTO THE WEEKEND
WITH SCATTERED SNOW SHOWERS GRADUALLY DIMINISHING.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY/...
A BAND OF STEADY LIGHT RAIN IS MOVING EAST ACROSS CENTRAL NY THIS
AFTERNOON WITH A CHANGE-OVER TO LIGHT SNOW ALREADY OCCURRING OVER
THE HIGHER ELEVATIONS AS OF 3 PM. THIS BAND WILL LIFT EAST-
NORTHEAST TOWARD THE CATSKILLS AND MOHAWK VALLEY THROUGH LATE THIS
AFTERNOON WITH LOWER ELEVATIONS GRADUALLY MIXING WITH OR CHANGING
TO LIGHT SNOW AS COLDER AIR FILTERS IN FROM THE WEST. MEANWHILE...
MAINLY DRY WEATHER CAN BE EXPECTED TO CONTINUE IN THE WILKES-BARRE
AND SCRANTON AREAS AND POINTS SOUTH WITH PRECIPTIATION REMAINING
TO THE NORTH.
PRECIPITATION SHOULD BECOME SPOTTIER AND LIGHTER EARLY THIS
EVENING IN MANY AREAS... THEN UPPER LEVEL LOW PRESSURE CURRENTLY
OVER WESTERN MICHIGAN WILL TRACK RAPIDLY EAST ACROSS THE AREA
LATER TONIGHT. THIS COULD RESULT IN A PERIOD OF ENHANCED SNOW
SHOWERS AGAIN LATE TONIGHT INTO EARLY THURSDAY MORNING. A BIT OF
LAKE ENHNACEMENT COULD ALSO OCCUR SOUTHEAST OF LAKE ONTARIO LATE
TONIGHT AS 850 MB TEMPERATURES FALL TO AROUND -8 C. LATEST HIGH
RESOLUTION NAM AND HRRR BOTH SUPPORT THE IDEA THAT SNOW SHOWERS
MAY INCREASE IN COVERAGE LATE TONIGHT WITH THE PASSAGE OF THIS
SYSTEM. BASED ON THIS HAVE UPPED POPS INTO THE LIKELY CATEGORY
LATER TONIGHT AND HAVE UP TO AN INCH OF SNOW POSSIBLE ESPECIALLY
AT HIGHER ELEVATIONS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
UPPER LEVEL AND SURFACE LOW PRESSURE WILL TRACK SLOWLY EAST ACROSS
THE SOUTHERN CANADIAN MARITIMES THURSDAY THROUGH FRIDAY. FLOW
ACROSS OUR AREA IN THE WAKE OF THIS SYSTEM WILL BE NORTHWESTERLY WITH
PLENTY OF LOW-LEVEL MOISTURE AND 850 MB TEMPERATURES HOLDING
AROUND -8 TO -10 C... WHICH WILL BE JUST COLD ENOUGH FOR A MINOR
LAKE RESPONSE IN THE NORTHWEST FLOW. HOWEVER MOISTURE WILL BECOME
INCREASINGLY SHALLOW WITH CONSIDERABLE DRYING IN THE -10 TO -20
DEGREE SNOW GROWTH ZONE BY THURSDAY AFTERNOON. BASED ON THIS
EXPECT JUST SCATTERED LIGHT SNOW SHOWERS THURSDAY AFTERNOON INTO
FRIDAY WITH ONLY MINIMAL ACCUMULATIONS. SOME FREEZING DRIZZLE
MIGHT EVEN OCCUR THURSDAY NIGHT ALTHOUGH AT THIS POINT I THINK
THAT IS A LOW PROBABILITY SCENARIO AND I HAVE NOT INCLUDED ZL IN
THE GRIDDED FORECAST. AT THIS POINT IT APPEARS THAT CLOUDS WILL
PERSIST THROUGH FRIDAY. WITH PLENTY OF CLOUDS WE ARE NOT EXPECTING
MUCH DIURNAL VARIATION IN TEMPERATURES THROUGH FRIDAY WITH HIGHS
MAINLY 30 TO 35 AND LOWS 20 TO 25 IN MOST PLACES.
BEST CHANCE TO SEE ANY SUNSHINE MIGHT BE EARLY SATURDAY BEFORE
CLOUDS AHEAD OF THE NEXT SYSTEM STREAM NORTHEAST ACROSS THE AREA
DURNIG THE AFTERNOON. SATURDAY SHOULD BE DRY WITH TEMPERATURES
AGAIN MAINLY IN THE 30S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
1 PM UPDATE..
FOLLOWED WPC GUIDANCE FOR THE MOST PART. SAT NGT AND SUN SOME
LIGHT SNOW WITH AN INVERTED TROF FROM A COASTAL STORM WELL OUT TO
SEA. SNOW ACCUMULATIONS WILL BE MOSTLY 2 INCHES OR LESS.
DRY SUN NGT AND MON WITH A MILD SFC HIGH. MON NGT AND TUE MODELS
NOW TRYING TO BRING A WEAK COASTAL STORM NE INTO THE AREA WITH
MIXED PRECIP. ADDED SOME LOW CHC POPS.
WED A STRONG OCCLUDED FRONT LIFTS NE AHEAD OF A LARGE BOMBING
STACKED LOW IN THE MIDWEST. WARM AIR SO PRECIP MOSTLY RAIN. THIS
WILL NEED TO BE WATCHED FIRST FOR RAIN AMOUNTS AND POSSIBLY
FLOODING AND SECOND FOR STRONG GUSTY WINDS.
ON THE TAIL END OF THE STEADY RAIN IT WILL CHANGE OVER TO SNOW WED
NGT AND STAY COLD THE REST OF THE WEEK WITH WRAP AROUND SNOW.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
1230 PM UPDATE...
MAINLY MVFR CIGS AND VFR VSBYS NEXT 24 HOURS.
CAA WITH NW FLOW SETTING UP CHANGING RAIN SHOWERS TO SNOW. GETTING
ON THE BACK SIDE OF AN UPPER LEVEL LOW WHILE THE SFC LOW IS WELL
NE NEAR OTTAWA. PRECIP STILL IN NY BUT LIFTING NORTH SO THAT ONLY
SYR AND RME WILL HAVE SNOW SHOWERS AND FLURRIES TONIGHT. THIS WILL
KEEP CIGS MVFR AND POSSIBLY VSBY IN HEAVIER SNOW SHOWERS.
ELM WILL FALL TO MVFR CIGS AND BE MAINLY DRY. IMPROVEMENT THU MORN
TO VFR. BGM NOW HAS IFR CIGS BUT THAT SHOULD LIFT TO LOW MVFR LATE
TODAY AS THE STEADIER PRECIP LIFTS NORTH. ITH LOW MVFR NOW AND
TONIGHT. ITH AND BGM IMPROVE TO HIGHER MVFR THU MORN.
AVP SHOULD BE MOSTLY VFR AND DRY.
WEST WINDS AT 10 KTS WITH SOME SPORADIC GUSTS THIS AFTN. W TO NW
WINDS TONIGHT AT 10 KTS THEN THU 10 TO 15 KTS WITH HIGHER GUSTS.
OUTLOOK...
THUR AFTN TO FRI... MAINLY VFR. MVFR/IFR RESTRICTIONS ARE PSBL AT
KRME/KSYR/KITH/KBGM DUE TO CIGS AND AT TIMES WITH -SHSN.
FRI NGT TO SAT...VFR.
SAT NGT AND SUN...MVFR/IFR IN LIGHT SNOW.
SUN NGT AND MON...VFR/MVFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE
NEAR TERM...MSE
SHORT TERM...MSE
LONG TERM...TAC
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1248 PM CST WED DEC 17 2014
.UPDATE...
ISSUED AT 1237 PM CST WED DEC 17 2014
LITTLE CHANGES TO THE FORECAST WITH SFC HIGH PRESSURE CENTERED
OVER NE ND GIVING THE CLEAR SKIES TO MOST OF THE AREA WITH MID
CLOUDS DIMINISHING ACROSS NW MN. TEMPERATURES ARE RESPONDING WELL
TO THE FULL SUN...EVEN AT ITS LOW ELEVATION...WITH THE LACK OF
SNOW PACK...AND WILL TWEAK THEM UP A TOUCH FOR THE AFTN MAXES.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 309 AM CST WED DEC 17 2014
TEMPERATURES WILL BE THE MAIN ISSUE FOR THE SHORT TERM.
THE UPPER LOW OVER THE GREAT LAKES WILL PULL FURTHER AWAY FROM THE
PLAINS TODAY...WITH SOME SLIGHTLY HIGHER HEIGHTS MOVING IN BEHIND.
SFC HIGH PRESSURE WILL CONTINUE TO EXTEND FROM CANADA INTO THE
CWA. CLOUDS CONTINUE OVER OUR EASTERN COUNTIES AND WILL HAVE TO
WATCH IF THEY PUSH FURTHER WEST. THINK THAT MORE CLOUDS WILL MOVE
INTO THE VALLEY TOWARDS SUNRISE BUT THINK THAT THEY SHOULD BE
SHORT LIVED AS THE RAP HAS RH VALUES DECREASING A BIT AS WE HEAD
INTO THE DAY. KEPT EAST OF THE RED RIVER IN THE MOSTLY CLOUDY
RANGE. TEMPS THIS MORNING IN THE WEST HAVE DROPPED BELOW ZERO
UNDER CLEAR SKIES...BUT THINK THERE SHOULD BE ENOUGH SUN TO GET
BACK INTO THE TEENS FOR HIGHS.
TONIGHT...A WEAK SHORTWAVE WILL MOVE INTO THE WESTERN DAKOTAS...BUT
NOT MUCH MOISTURE WITH IT ACCORDING TO THE MODELS. THE SFC HIGH
WILL START TO MOVE EAST IN RESPONSE...WITH SOUTHERLY WINDS
RETURNING. AT THIS POINT THINK THE WESTERN COUNTIES WILL AGAIN SEE
CLEAR SKIES BUT SOME MIXING FROM WINDS WILL KEEP TEMPS ABOVE ZERO
WHILE THE EAST WILL HAVE CLOUDS AND BE NEAR 10 DEGREES. THE
SOUTHERLY WINDS WILL PICK UP ON THURSDAY AND THERE SHOULD BE SOME
INCREASING CLOUDS THROUGHOUT THE DAY AS MOISTURE RETURN PICKS UP.
THERE WILL ALSO BE SOME WARM AIR ADVECTION SO TEMPS SHOULD BE ABLE
TO RETURN TO THE 20S.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 309 AM CST WED DEC 17 2014
THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE WEAK UPPER TROUGH
CONTINUES TO MAKE ITS WAY ACROSS THE NORTHERN PLAINS. THE
SOUTHERLY WINDS AND WARM AIR ADVECTION WILL CONTINUE...WITH THE
MODELS SHOWING SOME ISENTROPIC LIFT MOVING IN LATE THURSDAY NIGHT
AND INTO FRIDAY. CONDENSATION PRESSURE DEFICITS ARE NOT OVERLY
HIGH AND LIFT IS PRETTY WEAK. MODELS ALL PUT OUT VERY MINIMAL QPF
BUT SOME LIGHT SNOW IS NOT OUT OF THE QUESTION. KEPT SOME LOW POPS
GOING FRIDAY...BUT ANY ACCUMULATIONS WILL BE MINIMAL. TEMPS WILL
CONTINUE TO MODERATE WITH LOWS IN THE TEENS AND HIGHS ON FRIDAY
IN THE 20S.
FOR SATURDAY THROUGH TUESDAY...WEATHER OVER THE AREA IS EXPECTED
TO REMAIN FAIRLY TRANQUIL AS MOST OF THE JET ENERGY STAYS TO THE
SOUTH. SOUTHWESTERLY FLOW AT THE SFC BEHIND THE SFC RIDGE AND
INCREASING THICKNESS VALUES INDICATE A SLOW WARMING TREND...WITH
TEMPS REMAINING ABOVE NORMAL. NEXT CHANCE FOR PCPN WILL BE ON
MONDAY AS A WEAK PACIFIC WAVE CROSSES THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1237 PM CST WED DEC 17 2014
HIGH PRESSURE OVER THE RED RIVER VALLEY WILL SLOWLY DRIFT EAST
TONIGHT WITH WINDS TURNING LIGHT SOUTHERLY IN THE RRV/ERN ND AFTER
00Z WHILE AREAS EAST OF THE VALLEY GOES LIGHT AND VARIABLE TONIGHT.
SKIES GENERALLY CLEAR TONIGHT. THERE IS ONE PATCH OF MID CLOUD
TVF-FSE AREA MOVING WEST AND IT MAY MAKE IT TO GFK AT MID AFTN FOR A
FEW HOURS BUT ALSO MAY JUST DISSIPATE. THE MVFR CIGS IN WRN ND WILL
STAY OUT IN THAT AREA BUT COULD MOVE EAST SOME AS SOUTHERLY WINDS
GET MORE PRONOUNCED THURSDAY. FOR NOW WILL KEEP LOWER CIGS WEST OF
DVL THRU 18Z THU.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JK
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1221 PM CST WED DEC 17 2014
.UPDATE...
ISSUED AT 1216 PM CST WED DEC 17 2014
EASTERN EDGE OF BROAD CLOUD COVER OVER WESTERN AND CENTRAL NORTH
DAKOTA HAS BEEN DOING SOME ERODING...THOUGH SOME AREAS THAT ERODED
HAD QUICK RE-DEVELOPMENT. WITH THAT SAID...WILL KEEP CLOUDS IN THE
FORECAST THROUGH THE AFTERNOON OVER AFOREMENTIONED AREAS AS EXPECT
ANY BREAKS THAT DO DEVELOP WILL NOT TAKE LONG TO FILL BACK IN.
UPDATE ISSUED AT 838 AM CST WED DEC 17 2014
BROAD AREA OF CLOUD COVER CONTINUES OVER THE WEST HALF OF THE
STATE AND HAS BEEN TRYING TO BUILD A LITTLE TO THE EAST THIS
MORNING. FOR MORNING UPDATE HAVE ADJUSTED THE EASTERN EDGE A BIT
WITH CURRENT TRENDS. MODELS DIFFER A BIT ON WHETHER THE CLOUD
COVER WILL RETREAT SOME LATER TODAY...BUT FOR NOW WILL GO WITH
CONSISTENCY SINCE THIS HAS NOT BUDGED MUCH FOR THE PAST DAY.
UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 657 AM CST WED DEC 17 2014
CURRENT FORECAST LOOKS ON TRACK...NO CHANGES MADE. BLENDED IN
CURRENT OBSERVATIONS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 302 AM CST WED DEC 17 2014
THE CHALLENGE TODAY IS SIMILAR TO TUESDAY WITH FORECASTING THE
MOVEMENT OF A DISTINCT/SHARP DELINEATION OF CLOUDS/NO
CLOUDS...ALIGNED FAIRLY CLOSE TO AND ALONG HIGHWAY 83 THIS
MORNING. A SOLID OVERCAST WITH ISOLATED FLURRIES DOMINATE ALONG
AND TO THE WEST OF THIS LINE...WITH MOSTLY CLEAR CONDITIONS
EXTENDING EAST OF THIS LINE. TEMPERATURES DEPENDENT ON THE
MOVEMENT OF THIS LINE TODAY/TONIGHT. IN ADDITION...THE APPROACH OF
SHORTWAVE TROUGH ALOFT AND A WARM FRONT INTO EASTERN MONTANA THIS
EVENING/WEDNESDAY NIGHT WILL RESULT IN ISENTROPIC LIFT AND A
SLIGHT CHANCE OF VERY LIGHT SNOW IN THE SOUTHWEST.
THE LATEST FOG/STRATUS IMAGERY LOOP REMAINS NEARLY UNCHANGED IN
THE LAST 6 HOURS WITH THE STRATUS LINE NUDGING A BIT FARTHER
EAST...NOW INTO MINOT AND LINTON AGAIN. THE HRRR/RAP13/NAM/GFS
925MB RH TREND SHOWS NEARLY A STATIONARY SITUATION WITH THE STRATUS
DECK DURING THE DAY...FOLLOWED BY A GRADUAL PUSH EAST WEDNESDAY
EVENING AND WEDNESDAY NIGHT. THE LATEST HRRR ALSO HAS PATCHY FOG
DEVELOPING ACROSS THE SOUTHWEST AS THE STRATUS DECK CONTINUES TO
LOWER THIS MORNING. THIS SEEMS REASONABLE AND HAVE ADDED THIS INTO THE
FORECAST THROUGH 18Z. AS MENTIONED ABOVE...ISENTROPIC LIFT PER NAM
285K PRESSURE SURFACE ACROSS THE SOUTHWEST LATER THIS AFTERNOON
INTO TONIGHT WILL BE ENOUGH FOR A SIGHT CHC MENTION OF LIGHT
SNOW...ALTHOUGH EXPECTING LIMITED AMOUNTS WITH LIQUID EQUIVALENCIES
OF BETWEEN ONE AND TWO HUNDREDTHS OF AN INCH. OTHERWISE CLOUDS
REMAIN IN-TACT THROUGH THE SHORT TERM PERIOD WEST WITH ISOLATED
FLURRIES...AND MOSTLY SUNNY EAST CENTRAL. HIGHS TODAY WILL RANGE
FROM LOWER TO MID TEENS FROM THE TURTLE MOUNTAINS SOUTH TO THE
JAMES RIVER VALLEY...TO THE LOWER 20S SOUTHWEST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 302 AM CST WED DEC 17 2014
A QUIET START TO THE EXTENDED FORECAST TRANSITIONING INTO A
POTENTIALLY MORE ACTIVE PATTERN EARLY TO MID NEXT WEEK HIGHLIGHTS
THE LONG TERM.
THE 00 UTC GUIDANCE SUITE IS IN AGREEMENT ON SPLIT FLOW ACROSS THE
CENTRAL CONUS THURSDAY INTO SATURDAY...FAVORING HIGHS SLIGHTLY
ABOVE NORMAL IN THE MID 20S TO MID 30S AND DRY CONDITIONS.
THEREAFTER...ENERGY COMING ON SHORE TO THE PACIFIC NORTHWEST THIS
WEEKEND IS FORECAST TO PROPAGATE INTO THE CENTRAL CONUS LATE
SUNDAY INTO TUESDAY. THIS WOULD LEAD TO AN AMPLIFICATION OF THE
UPPER LEVEL PATTERN WITH A DEEPENING CENTRAL CONUS TROUGH. THIS
WILL HAVE TO BE MONITORED FOR POTENTIAL WINTER WEATHER CHRISTMAS
TRAVEL IMPACTS NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1216 PM CST WED DEC 17 2014
WIDESPREAD MVFR CIGS WITH LCL IFR CIGS WILL REMAIN OVER WESTERN
INTO PARTS OF CENTRAL NORTH DAKOTA TODAY. EXPECT LOWER CIGS TO
SPREAD EASTWARD OVERNIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...KS
LONG TERM...AYD
AVIATION...JJS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
551 PM EST WED DEC 17 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL NOSE INTO THE REGION TONIGHT. HOWEVER
ABUNDANT LOW LEVEL MOISTURE WILL RESULT IN A CONTINUATION OF MAINLY
CLOUDY SKIES. A WEAK UPPER LEVEL DISTURBANCE COULD LEAD TO A FEW
FLURRIES THURSDAY AFTERNOON INTO THURSDAY NIGHT. HIGH PRESSURE WILL
BUILD BACK IN OFFERING DRY CONDITIONS AND NEAR SEASONABLE
TEMPERATURES FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
ELONGATED MID LEVEL LOW OVER THE GREAT LAKES TO SHIFT OFF INTO NEW
ENGLAND. A FEW ISOLD LINGERING FLURRIES IN THE LOW LEVEL CAA WILL
COME TO AN END EARLY. MID LEVEL FLOW BECOMES BRIEFLY NW AHEAD OF AN
UPSTREAM S/W RIDGE. SFC HIGH PRESSURE TO NOSE INTO THE OHIO VALLEY
OVERNIGHT IN REGION OF H5 CONFLUENCE. 12Z ILN SOUNDING SHOWS LOW
LEVEL MOISTURE TRAPPED BELOW AN INVERSION AROUND 850 MB. GFS IS
AGGRESSIVE WITH CLEARING LOW LEVEL MOISTURE. NAM AND RAP SOLNS KEEP
CLOUDS OVERNIGHT. WILL ALLOW A FEW BREAKS OVER THE SOUTH/SOUTHWEST
BUT LEAN TOWARD THE NAM/RAP SOLN. TEMPERATURES WILL BE CLOSE TO
NORMAL WITH LOWS FROM THE MID 20S NORTH TO THE UPPER 20S SOUTH.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
MID LEVEL S/W TO RIPPLE QUICKLY EAST FROM THE CENTRAL PLAINS
THROUGH THE OHIO VALLEY THURSDAY. THIS WEAK SHORTWAVE IS DAMPENING
AND CROSSING OVER THE SFC RIDGE. FORCING IS VERY WEAK AND IN THE
MID LEVELS. A FLURRY OR SPRINKLE IS NOT OUT OF THE QUESTION FROM A
MID DECK. FLURRIES/SPRINKLES ALREADY IN THE FORECAST...SO WILL
CONTINUE. TEMPERATURES WILL BE BELOW NORMAL WITH HIGHS FROM THE
LOWER 30S NORTH TO THE MID/UPR 30S SOUTH.
IN WESTERLY MID LEVEL FLOW REGIME...SFC HIGH PRESSURE TO BUILD
ACRS THE GREAT LAKES/OHIO VALLEY THURSDAY NIGHT/FRIDAY. A FEW
FLURRIES WILL REMAIN POSSIBLE THURSDAY EVENING BUT WILL COME TO AN
END WITH THE PASSAGE OF THE S/W. AS THE HIGH BUILD NOSES IN
EXPECT SOME PARTIAL CLEARING THURSDAY NIGHT. LOWS EXPECTED TO
RANGE FROM THE MID 20S NORTH TO THE UPPER 20S SOUTH.
EXPECT TO SEE MORE SUNSHINE FRIDAY WITH AN INCREASE IN HIGH LEVEL
MOISTURE LATE IN THE DAY. FRIDAYS HIGHS FROM THE MID 30S NORTH TO
NEAR 40 SOUTH.
CLOUDS WILL THICKEN AND INCREASE FRIDAY NIGHT AS SYSTEM APPROACHES
FROM THE SOUTHWEST. WILL KEEP FCST DRY FRIDAY NIGHT AS CONSENSUS
DOES NOT BRING MOISTURE IN UNTIL SATURDAY. LOWS FRIDAY NIGHT TO
RANGE FROM THE UPPER 20S NORTH TO THE LOWER 30S FAR SOUTH.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
FOR SATURDAY...LOOKS LIKE WE COULD SEE SNOW CHANGING TO RAIN AS LOW
PRESSURE TRAVELS NEAR THE GULF COAST. THE LOW HAS TRENDED FARTHER TO
THE SOUTH SO CUT BACK ON POPS AND PRECIP AMOUNTS. HIGH PRESSURE AND
A COOL AIRMASS SHOULD ALLOW DRY WEATHER ON SUNDAY. LIGHT PRECIP WILL
BE POSSIBLE MONDAY EXTENDING FROM A TROUGH ALONG THE EAST COAST.
WE MAY BEGIN TO FEEL THE EFFECTS OF A POWERFUL LOW PRESSURE SYSTEM
ON TUESDAY. HAVE LESS THAN AVERAGE AMOUNT OF CONFIDENCE DUE TO MODEL
DIFFERENCES FROM RUN TO RUN. AT THIS POINT IT APPEARS THE LOW WILL
DEVELOP OVER THE SOUTHERN PLAINS ON TUESDAY...BEFORE LIFTING THROUGH
OHIO TO THE GREAT LAKES ON WEDNESDAY. THE LOW MAY FEATURE A VERY
TIGHT PRESSURE GRADIENT SURROUNDING ITS DEEP CENTER...PRODUCING
STRONG WINDS. COPIOUS MOISTURE FEEDING FROM THE TROPICS AND FROM THE
ATLANTIC OCEAN COULD ADVECT AROUND THE LOW. CURRENT TEMPERATURE
FORECAST ALLOWS RAIN TUESDAY INTO WEDNESDAY...CHANGING TO SNOW LATER
WEDNESDAY AS COLDER AIR WRAPS IN BEHIND THE LOW.
TEMPERATURES WILL BE RELATIVELY CLOSE TO NORMAL FOR THE MOST PART.
HIGHS ARE FORECAST TO BE IN THE MID AND UPPER 30S SATURDAY...THEN A
COUPLE DEGREES WARMER FOR SUNDAY AND MONDAY UNDER NEUTRAL TO WEAK
WARM ADVECTION. READINGS ON TUESDAY AND WEDNESDAY WILL BE DEPENDENT
ON THE POSITION OF THE ANTICIPATED STRONG LOW. WARM ADVECTION AHEAD
OF THE LOW COULD BRING HIGHS UP INTO THE MID 40S ON TUESDAY...OR
EVEN HIGHER IF THE WARMER MEX GUIDANCE VERIFIES. HIGHS COULD SLIP TO
AROUND 40 ON WEDNESDAY IN COLD ADVECTION BEHIND THE LOW.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
A PERSISTENT MVFR CLOUD DECK IS LIKELY TO REMAIN IN PLACE ACROSS
THE TAF SITES THROUGH THE ENTIRE FORECAST PERIOD. THESE CLOUDS ARE
GENERALLY LOCATED BETWEEN 1200 AND 2200 FEET ABOVE GROUND
LEVEL...AND LITTLE CHANGE IN HEIGHT IS EXPECTED...THOUGH A SLIGHT
LIFTING IS POSSIBLE TOMORROW. THIS CLOUD DECK HAS SHOWN SOME SIGNS
OF EROSION FROM THE SOUTH...BUT WHILE IT APPEARS POSSIBLE THAT
BREAKS IN THE OVERCAST COULD WORK INTO THE CINCINNATI AREA
OVERNIGHT...IT IS MORE LIKELY THAT THIS EROSION WILL SLOW OR STOP
IN THE NEXT FEW HOURS.
WNW WINDS OF AROUND 10 KNOTS WILL DIMINISH OVERNIGHT...AND REMAIN
UNDER 10 KNOTS TOMORROW. A FEW FLURRIES WILL BE POSSIBLE...MAINLY
AFTER 18Z...WITH NO EXPECTED IMPACTS TO AVIATION.
OUTLOOK...MVFR CEILINGS MAY CONTINUE INTO FRIDAY. MVFR CEILINGS AND
VISIBILITIES ARE POSSIBLE ON SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...AR
NEAR TERM...AR
SHORT TERM...AR
LONG TERM...CONIGLIO
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
428 PM EST WED DEC 17 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL NOSE INTO THE REGION TONIGHT. HOWEVER
ABUNDANT LOW LEVEL MOISTURE WILL RESULT IN A CONTINUATION OF MAINLY
CLOUDY SKIES. A WEAK UPPER LEVEL DISTURBANCE COULD LEAD TO A FEW
FLURRIES THURSDAY AFTERNOON INTO THURSDAY NIGHT. HIGH PRESSURE WILL
BUILD BACK IN OFFERING DRY CONDITIONS AND NEAR SEASONABLE
TEMPERATURES FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
ELONGATED MID LEVEL LOW OVER THE GREAT LAKES TO SHIFT OFF INTO NEW
ENGLAND. A FEW ISOLD LINGERING FLURRIES IN THE LOW LEVEL CAA WILL
COME TO AN END EARLY. MID LEVEL FLOW BECOMES BRIEFLY NW AHEAD OF AN
UPSTREAM S/W RIDGE. SFC HIGH PRESSURE TO NOSE INTO THE OHIO VALLEY
OVERNIGHT IN REGION OF H5 CONFLUENCE. 12Z ILN SOUNDING SHOWS LOW
LEVEL MOISTURE TRAPPED BELOW AN INVERSION AROUND 850 MB. GFS IS
AGGRESSIVE WITH CLEARING LOW LEVEL MOISTURE. NAM AND RAP SOLNS KEEP
CLOUDS OVERNIGHT. WILL ALLOW A FEW BREAKS OVER THE SOUTH/SOUTHWEST
BUT LEAN TOWARD THE NAM/RAP SOLN. TEMPERATURES WILL BE CLOSE TO
NORMAL WITH LOWS FROM THE MID 20S NORTH TO THE UPPER 20S SOUTH.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
MID LEVEL S/W TO RIPPLE QUICKLY EAST FROM THE CENTRAL PLAINS
THROUGH THE OHIO VALLEY THURSDAY. THIS WEAK SHORTWAVE IS DAMPENING
AND CROSSING OVER THE SFC RIDGE. FORCING IS VERY WEAK AND IN THE
MID LEVELS. A FLURRY OR SPRINKLE IS NOT OUT OF THE QUESTION FROM A
MID DECK. FLURRIES/SPRINKLES ALREADY IN THE FORECAST...SO WILL
CONTINUE. TEMPERATURES WILL BE BELOW NORMAL WITH HIGHS FROM THE
LOWER 30S NORTH TO THE MID/UPR 30S SOUTH.
IN WESTERLY MID LEVEL FLOW REGIME...SFC HIGH PRESSURE TO BUILD
ACRS THE GREAT LAKES/OHIO VALLEY THURSDAY NIGHT/FRIDAY. A FEW
FLURRIES WILL REMAIN POSSIBLE THURSDAY EVENING BUT WILL COME TO AN
END WITH THE PASSAGE OF THE S/W. AS THE HIGH BUILD NOSES IN
EXPECT SOME PARTIAL CLEARING THURSDAY NIGHT. LOWS EXPECTED TO
RANGE FROM THE MID 20S NORTH TO THE UPPER 20S SOUTH.
EXPECT TO SEE MORE SUNSHINE FRIDAY WITH AN INCREASE IN HIGH LEVEL
MOISTURE LATE IN THE DAY. FRIDAYS HIGHS FROM THE MID 30S NORTH TO
NEAR 40 SOUTH.
CLOUDS WILL THICKEN AND INCREASE FRIDAY NIGHT AS SYSTEM APPROACHES
FROM THE SOUTHWEST. WILL KEEP FCST DRY FRIDAY NIGHT AS CONSENSUS
DOES NOT BRING MOISTURE IN UNTIL SATURDAY. LOWS FRIDAY NIGHT TO
RANGE FROM THE UPPER 20S NORTH TO THE LOWER 30S FAR SOUTH.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
FOR SATURDAY...LOOKS LIKE WE COULD SEE SNOW CHANGING TO RAIN AS LOW
PRESSURE TRAVELS NEAR THE GULF COAST. THE LOW HAS TRENDED FARTHER TO
THE SOUTH SO CUT BACK ON POPS AND PRECIP AMOUNTS. HIGH PRESSURE AND
A COOL AIRMASS SHOULD ALLOW DRY WEATHER ON SUNDAY. LIGHT PRECIP WILL
BE POSSIBLE MONDAY EXTENDING FROM A TROUGH ALONG THE EAST COAST.
WE MAY BEGIN TO FEEL THE EFFECTS OF A POWERFUL LOW PRESSURE SYSTEM
ON TUESDAY. HAVE LESS THAN AVERAGE AMOUNT OF CONFIDENCE DUE TO MODEL
DIFFERENCES FROM RUN TO RUN. AT THIS POINT IT APPEARS THE LOW WILL
DEVELOP OVER THE SOUTHERN PLAINS ON TUESDAY...BEFORE LIFTING THROUGH
OHIO TO THE GREAT LAKES ON WEDNESDAY. THE LOW MAY FEATURE A VERY
TIGHT PRESSURE GRADIENT SURROUNDING ITS DEEP CENTER...PRODUCING
STRONG WINDS. COPIOUS MOISTURE FEEDING FROM THE TROPICS AND FROM THE
ATLANTIC OCEAN COULD ADVECT AROUND THE LOW. CURRENT TEMPERATURE
FORECAST ALLOWS RAIN TUESDAY INTO WEDNESDAY...CHANGING TO SNOW LATER
WEDNESDAY AS COLDER AIR WRAPS IN BEHIND THE LOW.
TEMPERATURES WILL BE RELATIVELY CLOSE TO NORMAL FOR THE MOST PART.
HIGHS ARE FORECAST TO BE IN THE MID AND UPPER 30S SATURDAY...THEN A
COUPLE DEGREES WARMER FOR SUNDAY AND MONDAY UNDER NEUTRAL TO WEAK
WARM ADVECTION. READINGS ON TUESDAY AND WEDNESDAY WILL BE DEPENDENT
ON THE POSITION OF THE ANTICIPATED STRONG LOW. WARM ADVECTION AHEAD
OF THE LOW COULD BRING HIGHS UP INTO THE MID 40S ON TUESDAY...OR
EVEN HIGHER IF THE WARMER MEX GUIDANCE VERIFIES. HIGHS COULD SLIP TO
AROUND 40 ON WEDNESDAY IN COLD ADVECTION BEHIND THE LOW.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
SURFACE HIGH PRESSURE LOCATED TO OUR WEST AND NORTHWEST WILL BUILD
INTO OUR REGION TONIGHT. DESPITE THIS HIGH...LOW LEVEL MOISTURE
REMAINS TRAPPED UNDERNEATH A SUBSIDENCE INVERSION. THIS HAS
RESULTED IN A PRETTY SOLID STRATOCUMULUS DECK BETWEEN 1500-2500
FEET. MODELS CONTINUE TO STRUGGLE AS TO WHETHER THESE CLOUDS WILL
THIN AND/OR ERODE THROUGH THE PERIOD. HAVE GONE PESSIMISTIC AT
THIS POINT WHICH IS TO KEEP MVFR CEILINGS GOING THROUGH THE TAF
PERIOD. ON THURSDAY...SURFACE HIGH PRESSURE WILL REMAIN OVER THE
AREA. A WEAK DISTURBANCE ALOFT IS FORECAST TO PASS EAST ACROSS THE
OHIO VALLEY. DEEPER MOISTURE AND FORCING SHOULD REMAIN TO OUR
SOUTHWEST WHILE THE FEATURE WEAKENS AS IT AFFECTS OUR AREA. IT
LOOKS LIKE THE ONLY THREAT FOR PRECIPITATION WOULD BE A FEW
FLURRIES.
OUTLOOK...MVFR CEILINGS MAY LINGER INTO FRIDAY. MVFR CEILINGS AND
VISIBILITIES POSSIBLE SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...AR
NEAR TERM...AR
SHORT TERM...AR
LONG TERM...CONIGLIO
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS MEDFORD OR
206 PM PST WED DEC 17 2014
.DISCUSSION...ANOTHER WEAK UPPER TROUGH IS NEAR THE COAST AND THIS
WILL MOVE INLAND THIS EVENING. CURRENT RADAR SHOWS TWO AREAS OF
SCATTERED SHOWERS. THE FIRST IS IN NORTHEAST SISKIYOU AND KLAMATH
COUNTY AND THE SECOND IS MOVING TOWARDS THE COAST. THIS SECOND
FEATURE WILL MOVE INLAND THIS EVENING AND BRING SCATTERED SHOWERS
OVER NORTHERN CAL AND SOUTHWEST OREGON. THE LATEST RAP MODELS
DEPICTS THE PLACEMENT OF THE PRECIPITATION WELL AND WILL FOLLOW THIS
FOR THIS EVENING. THE UPPER TROUGH WILL WEAKEN AS IT MOVES EAST AND
SHORTWAVE RIDGING BEGINS TO BUILD IN OVERNIGHT. THIS SHOULD SHUT OFF
THE SHOWER ACTIVITY OVER MOST OF THE AREA, ALTHOUGH SOME RESIDUAL
SHOWERS COULD LINGER IN SOUTHEAST SISKIYOU AND MODOC COUNTIES.
WE`LL CATCH A DRY BREAK ON THURSDAY WITH THE RIDGE AXIS OVER THE
AREA, BUT THIS WILL BE SHORT LIVED. THE MODELS SHOW A STRONGER FRONT
APPROACHING THE AREA THURSDAY AFTERNOON BRINGING INCREASING SOUTH
WINDS OVER THE MARINE WATERS WHICH ARE EXPECTED TO GET CLOSE TO
GALES. PRECIPITATION COULD ALSO REACH THE COAST AS EARLY AS THURSDAY
AFTERNOON. THE FRONT WILL MOVE INLAND THURSDAY NIGHT BRINGING
MODERATE TO HEAVY PRECIPITATION OVER THE USUAL SUSPECTS...THE COAST
RANGE...COASTAL MOUNTAINS AND CASCADES. HOWEVER THE MODELS ARE IN
GOOD AGREEMENT THE FRONT WILL BE A QUICK MOVER AND SO WE WON`T GET
SIGNIFICANT PRECIPITATION AMOUNTS. SNOW LEVELS WILL START OUT HIGH
THURSDAY NIGHT, BUT WILL DROP TO AROUND 4500 FEET EARLY FRIDAY
MORNING. SO IT`S A GOOD BET THE MOUNTAIN PASSES WILL GET
ACCUMULATING SNOW STARTING LATE THURSDAY NIGHT THROUGH FRIDAY
MORNING. CURRENT THINKING IS CRATER LAKE COULD PICK UP AT LEAST 6
INCHES OR MORE AND A FEW INCHES ARE POSSIBLE OVER SISKIYOU SUMMIT
AND HIGHWAY 140. KEEP IN MIND THE DETAILS ON THIS WILL CHANGE, SO
STAY TUNED FOR THE LATEST UPDATES.
THE ABOVE MENTIONED FRONT WILL QUICKLY MOVE THROUGH FRIDAY AND WE`LL
CATCH A RELATIVE BREAK IN PRECIPITATION FRIDAY AFTERNOON AND EVENING.
BUT AGAIN THIS WILL BE SHORT LIVED. THE MODELS ARE IN PRETTY GOOD
AGREEMENT SHOWING A STRONG WARM FRONT ARRIVING AT THE COAST LATE
FRIDAY NIGHT AND MOVING OVER THE AREA SATURDAY. THIS FRONT HAS A LOT
OF JUICE WITH IT AND HEAVY PRECIPITATION WILL LIKELY IMPACT THE
COAST...COAST RANGE...COASTAL MOUNTAINS AND CASCADES. MODERATE TO
HEAVY PRECIPITATION WILL ALSO IMPACT MUCH OF THE WESTSIDE VALLEYS. OF
NOTE THE IVT TRANSPORT (WHICH IS GFS BASED) PUTS THE HIGHEST VALUES
IN CENTRAL AND NORTHWEST OREGON. EVEN THE GEFS ENSEMBLE MEAN IS
SIMILAR TO THE OPERATIONAL GFS. ADDITIONALY, THE UPPER FLOW IS
ALMOST DUE WEST WHICH WILL SQUEEZE OUT EVEN MORE MOISTURE ALONG THE
COAST RANGE. ALSO WINDS WILL INCREASE AHEAD OF THE FRONT AND THERE
IS A CHANCE FOR GALE FORCE WINDS OVER THE MARINE WATERS AND MODERATE
TO STRONG WINDS OVER THE COAST AND HEADLANDS. IF THAT WEREN`T ENOUGH
THERE IS CONCERN FOR SNOW EAST OF THE CASCADES AS THE WARM FRONT
ARRIVES. MODEL SOUNDINGS SUPPORT THE IDEA THAT ENOUGH COLD AIR WILL
BE PRESENT NEAR THE SURFACE AND THIS IN COMBINATION WITH OVERRUNNING
PRECIPITATION COULD BRING A PERIOD OF SNOW SATURDAY MORNING.
STRONG WESTERLY FLOW CONTINUES SATURDAY NIGHT WITH THE HEAVIEST
PRECIPITATION WEST OF THE CASCADES, BUT SNOW LEVELS WILL JUMP UP TO
AROUND 7000 FEET SATURDAY AFTERNOON AND REMAIN HIGH SATURDAY NIGHT.
-PETRUCELLI
LONG-TERM FORECAST...SUNDAY THROUGH WEDNESDAY. A BROAD LONG WAVE
RIDGE WILL BE IN PLACE AT THE BEGINNING OF THE EXTENDED PERIOD WITH
WITH GENERALLY NORTHWEST FLOW ALOFT. SHORT WAVES RIDING OVER THE TOP
OF THE RIDGE WILL WEAKEN IT FROM SUNDAY NIGHT ON...BUT IT WILL
REMAIN IN PLACE THROUGH TUESDAY. THE FLOW ALOFT WILL BECOME MORE
ZONAL TUESDAY.
THIS PATTERN WILL FORCE THE MAIN STORM TRACK TO THE NORTH OF THE
MEDFORD CWA...BUT THE AREA WILL STILL CATCH THE SOUTHERN END OF
SEVERAL SYSTEMS WHICH WILL MOVE ONSHORE DURING THIS INTERVAL. THE
STRONGEST OF THESE SYSTEMS WILL MOVE ONSHORE SATURDAY AFTERNOON AND
EVENING...AND WILL BE OVER THE CWA SUNDAY. REINFORCING SHORT WAVES
WILL KEEP THE PRECIPITATION GOING THROUGH MOST OF MONDAY. THE BULK
OF THE ASSOCIATED PRECIPITATION WILL FALL ALONG THE COAST...COAST
RANGE...AND UMPQUA BASIN. AMOUNTS WILL BE SIGNIFICANT BUT NOT
EXCESSIVE...NO FLOODING PROBLEMS ARE ANTICIPATED. SNOW LEVELS WILL
BE ABOVE 7000 FEET.
MONDAY NIGHT INTO TUESDAY LOOK TO BE MOSTLY DRY WITH NEARLY ALL THE
ACTION TO THE NORTH OF THE AREA.
THE RIDGE WILL BREAK DOWN WEDNESDAY AND A LONG WAVE TROUGH WILL
BEGIN TO DIG OFFSHORE. THIS CHANGE IN PATTERN WILL SUPPORT A FRONT
MOVING ONSHORE WEDNESDAY. THIS WILL BE THE WETTEST SYSTEM OF THE
EXTENDED PERIOD IF THE CURRENT EC/GFS MODEL SOLUTIONS PAN OUT. SNOW
LEVELS MAY ALSO FALL AS LOW AS 4000 FEET BEHIND THE FRONT WEDNESDAY
NIGHT...SO SNOW MAY RETURN TO THE PASSES AROUND THAT TIME. -JRS
&&
.AVIATION...BASED ON THE 17/18Z TAF CYCLE...VFR CONDITIONS WILL
PREVAIL INITIALLY WITH AREAS OF HIGHER TERRAIN OBSCURED...EXCEPT FOR
WESTERN AND SOUTH CENTRAL SISKIYOU COUNTY...WHERE AREAS OF MVFR CIGS
WILL PREVAIL THROUGH THURSDAY MORNING. WIDESPREAD MVFR CIGS AND
AREAS OF IFR CIGS/VSBYS WILL RETURN TO THE WEST SIDE TONIGHT. KOTH
WILL BE AFFECTED BY THE MVFR CIGS AND KRBG AND KMFR WILL BE
AFFECTED BY THE IFR CIGS/VSBYS. ALL AREAS WILL CLEAR TO VFR BY
THURSDAY AFTERNOON. -JRS
&&
.MARINE...UPDATED 935 AM PST WED DEC 17 2014...WEAK LOW PRESSURE
SYSTEMS WILL MOVE THROUGH THE AREA TODAY AND TONIGHT. SOUTHWEST
SWELL DOMINATED SEAS WILL REMAIN MOSTLY AT OR ABOVE 10 FEET TODAY.
THURSDAY INTO THURSDAY NIGHT A STRONGER FRONTAL SYSTEM WILL LIKELY
BRING GALE FORCE WINDS AND VERY STEEP SOUTHWEST SEAS. HEAVY WEST
SWELL WILL BEGIN TO ARRIVE IN THE PREDAWN HOURS FRIDAY MORNING. IT
WILL PEAK FRIDAY NIGHT AT AROUND 19 FEET AT 18 SECONDS. A WARM FRONT
WILL MOVE THROUGH FRIDAY NIGHT...FOLLOWED BY A COLD FRONT SATURDAY.
OFFSHORE HIGH PRESSURE WILL BUILD SATURDAY NIGHT INTO SUNDAY. -JRS
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...GALE WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR
PZZ350-356-370-376.
HAZARDOUS SEAS WATCH FROM THURSDAY AFTERNOON THROUGH LATE
THURSDAY NIGHT FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST THIS
AFTERNOON FOR PZZ350-356-370-376.
$$
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1253 PM EST WED DEC 17 2014
.SYNOPSIS...
HIGH PRESSURE WILL SPREAD BACK OVER THE REGION TODAY BEHIND A
DEPARTING COLD FRONT. A WEAK WEATHER SYSTEM ALOFT WILL SPREAD CLOUDS
AND PERHAPS SOME SPOTTY LIGHT SHOWERS IN THE MOUNTAINS ON THURSDAY.
ANOTHER LOW WILL DEVELOP TO OUR SOUTHWEST ON FRIDAY AND INCREASE
CHANCES FOR WIDESPREAD PRECIPITATION GOING INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
930 AM EST UPDATE...HAVE DECREASED THE CLOUD COVER OVER PORTIONS OF
THE NC MTNS/VALLEYS PER LATEST VISBY SATELLITE IMAGERY TREND.
OTHERWISE...CURRENT FORECAST REMAINS ON TRACK.
AS OF 600 AM EST WEDNESDAY...LATEST RADAR TRENDS REMAIN RATHER
UNIMPRESSIVE REGARDING POSSIBLE LIGHT SHRA ACROSS THE NORTHERN
MTNS. THUS POP FCST WILL REMAIN AS IS WHICH FEATURES ALL POPS BEING
REMOVED WITH THE HOUR. LOW LEVEL STRATUS ACROSS THE MTNS IS STILL
FCST TO SCATTER THROUGH MORNING. MADE SLIGHT TWEAKS TO TEMPERATURES
AND DEWPOINTS TO REFLECT LATEST OBSERVATIONS.
PREVIOUS DISCUSSION...
AS OF 300 AM EST WEDNESDAY...QUASI ZONAL UPPER FLOW MIGRATING OVER
THE SOUTHEAST WHILE CANADIAN HIGH PRESSURE DIVES SOUTHWARD THROUGH
THE MS RIVER VALLEY INTO THE OH/TN VALLEYS. MODEST WEST/NORTHWEST
850MB FLOW ALONG THE CENTRAL APPS CONTINUES TO YIELD SCATTERED
SHOWERS ACROSS PORTIONS OF EASTERN KY NORTHWARD INTO WEST VIRGINIA.
ALTHOUGH AMPLE MOISTURE REMAINS FURTHER SOUTH ACROSS PORTIONS OF
WESTERN NC...WEAKER FLOW CONTINUES TO LIMIT COVERAGE. LATEST
NAM/GFS REMAIN PERSISTENT IN SUGGESTING INCREASING SHOWER COVERAGE
ALONG THE TN LINE NORTH OF INTERSTATE 40 THROUGH MID MORNING.
HOWEVER...HIGH RES GUIDANCE SUCH AS THE HRRR CONTINUES TO BACK OFF.
ALL SAID...WILL KEEP LOW END SLIGHT CHANCE POPS FOR ISOLATED SHOWERS
ACROSS THE NORTHERN MTNS THROUGH 12Z. FCST DOES FEATURE BRIEF
PERIOD OF FZRA FOR THESE ZONES AS MODEST INVERSION ALOFT SUGGESTS
PRECIP WILL FALL AS LIQUID WITH SOME FREEZING POSSIBLE TOWARD
MORNING LOWS. NOT EXPECTING ANY SIGNIFICANT IMPACTS BUT CANNOT RULE
OUT A FEW PATCHES OF BLACK ICE.
BEYOND THAT...HIGH PRESSURE WILL PREVAIL ACROSS THE REGION WITH
MOSTLY SUNNY SKIES DOMINATING OVER THE LOW TERRAIN. DID KEEP
MENTION OF MOSTLY/PARTLY CLOUDY SKIES ACROSS THE HIGH TERRAIN AS
WEAK WESTERLY UPSLOPE FLOW CONTINUES AMONGST SHALLOW MOIST LAYER.
MEANWHILE ANOTHER WEAK UPPER IMPULSE WILL BE SLIDING THROUGH THE
SOUTHERN PLAINS ALLOWING SOME HIGH LEVEL CIRRUS TO MOVE OVER THE
FCST AREA THIS AFTERNOON THROUGH PERIODS END. DOWNSLOPING FLOW WILL
YIELD NORMAL LEVEL HIGH TEMPERATURES ACROSS THE FOOTHILLS/PIEDMONT
REGIONS WHILE SLIGHTLY BELOW NORMAL HIGHS ARE FCST OVER THE MTNS.
LOWS TONIGHT WILL BE NEAR NORMAL AS ABOVE MENTIONED INCREASING HIGH
LEVEL CIRRUS LIMITS RADIATIONAL COOLING.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 325 AM WEDNESDAY...A WEAK SHORT WAVE WILL MOVE THRU THE ZONAL
FLOW ALOFT THU. THERE IS VERY LITTLE DEEP MOISTURE OR FORCING WITH
THIS SYSTEM. CANNOT RULE OUT A FEW SPRINKLES ACROSS THE NC MTNS
WHERE WLY FLOW MAY BE ABLE TO SQUEEZE THEM OUT OF THE MOISTURE.
THERE SHUD BE QUITE A BIT OF CLOUDS ACROSS THE AREA HOWEVER. SHORT
WAVE RIDGING DEVELOPS AHEAD OF THE NEXT WX SYSTEM APPROACHING FROM
THE SW ON FRI. THIS WILL BRING AN INCREASE IN CLOUDS THRU THE DAY
AFTER THE THU NITE CLEARING FROM THE DEPARTING SHORT WAVE. HIGHS
WILL BE NEAR NORMAL BOTH DAYS...WHILE LOWS THU NITE WILL BE A FEW
DEGREES ABOVE NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 355 AM WEDNESDAY...GUIDANCE REMAINS IN GOOD AGREEMENT ON THE
OVERALL PATTERN FOR THE WEEKEND STORM SYSTEM...BUT SOME DIFFERENCES
REMAIN REGARDING THE TEMPERATURE PROFILE AND RESULTING P-TYPES. A
SHORT WAVE APPROACHES THE AREA FRI NITE...MOVES ACROSS THE AREA SAT
AND EAST ON SAT NITE. AT THE SFC...A LOW PRESSURE SYSTEM MOVES EAST
ALONG THE GULF COAST WHILE HIGH PRESSURE SETS UP OVER THE AREA IN A
COLD AIR DAMMING CONFIGURATION. PRECIP CHC INCREASES FROM THE SW FRI
NITE AS MOISTURE MOVES IN AHEAD OF THIS SYSTEM...CAT POP DEVELOPS
ALL AREAS SAT AS THE LOW MOVES SOUTH OF THE AREA...WITH POP SLOWLY
TAPERING OFF SAT NITE AND ENDING ON SUN. THE GFS IS WARMER THAN THE
ECMWF...BUT THE ECMWF IS NOT VERY COLD. USING A BLEND OF THESE TWO
MDLS FOR TEMPS AND THICKNESSES RESULTS IN COLDEST TEMPS AND
THICKNESSES ALONG THE NRN TIER OF THE CWFA...POSSIBLY EXTENDING
SOUTH ALONG THE BLUE RIDGE TO THE SC BORDER. EVEN THEN...P-TYPE
SEEMS TO FAVOR A WINTRY MIX FOR THE NRN BLUE RIDGE AND FREEZING RAIN
EAST AND SOUTH OF THERE. RAIN IS THE P-TYPE FOR MOST OF THE CWFA.
CANNOT RULE OUT ADVISORY LEVEL ICE ACCUMS FOR THE NRN MTN LOCATIONS
LATE FRI NITE AND SAT MORN. HAVE GONE WITH RAIN OR SNOW AS PRECIP
COMES TO AN END SAT NITE AND SUN MORN...BUT THIS AND ANY POTENTIAL
ACCUMS ARE MUCH MORE UNCERTAIN. LOWS WILL BE ABOVE NORMAL FRI AND
SAT NITES...WITH HIGHS SAT 10 DEGREES BELOW NORMAL...RISING TO A FEW
DEGREES BELOW NORMAL ON SUN.
GUIDANCE BEGINS TO DIVERGE FOR THE REST OF THE MEDIUM RANGE. A DEEP
TROF DEVELOPS ACROSS THE CENTRAL CONUS...BUT THE ECMWF IS SLOWER AND
DEEPER WITH THE TROF THAN THE GFS. THE GFS ALSO BRINGS SOME WEAK
SHORT WAVE ENERGY ACROSS THE AREA AHEAD OF THE TROF ON MON...WHILE
THE ECMWF DAMPENS THE WAVE SIGNIFICANTLY. AT THE SFC...THE GFS HAS A
WELL DEFINED LOW PRESSURE SYSTEM WELL SOUTH OF THE AREA ACROSS
FLORIDA AND MOVES IN INTO THE ATLANTIC...KEEPING OUR CWFA RELATIVELY
DRY...WHILE THE ECMWF HAS A LESS DEFINED SFC LOW...BUT A STRONGER
BAROCLINIC ZONE CLOSER TO THE CWFA SPREADING PRECIP IN FROM THE
SOUTH. GIVEN THE DISCREPANCIES...HAVE KEPT MON BASICALLY DRY WITH
TEMPS NEAR NORMAL.
PRECIP SPREADS BACK INTO THE AREA TUE AS A FRONTAL SYSTEM ASSOCIATED
WITH THE UPPER TROF MOVES BACK INTO THE AREA FROM THE WEST.
HOWEVER...DETAILS DIFFER ON EXACT TIMING AND THERMAL STRUCTURE.
THEREFORE...HAVE CHC POP SPREADING IN FROM THE WEST TUE. AGAIN...
GIVEN THE DIFFERENCES...USED RAIN/SNOW FOR THE P-TYPE WHICH WOULD
INDICATE SOME SNOW AT ONSET ACROSS THE NC MTNS...BUT THIS IS ALSO
HIGHLY UNCERTAIN. TEMPS TUE NEAR NORMAL.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS WILL PREVAIL THROUGH THE TAF
PERIOD FOR ALL TERMINALS AS HIGH PRESSURE CONTINUES TO BUILD IN FROM
THE WEST. W/WSW WINDS THIS AFTERNOON WILL DECREASE VEER TO THE NW BY
THIS EVENING. WINDS WILL THEN VEER TO THE NE BY LATE TONIGHT/EARLY
THU MORNING. THE EXCEPTION WILL BE KAVL WHERE GUSTY N WINDS OF
15-20 KTS WILL CONTINUE THROUGH THIS AFTERNOON BEFORE DECREASING TO
AROUND 5-7 KTS OUT OF THE NORTH BY THIS EVENING. SKIES WILL REMAIN
MOSTLY CLEAR THROUGH TONIGHT...WITH HIGH CLOUDS OVERSPREADING THE
REGION BY EARLY TOMORROW MORNING AS AN UPPER SHORTWAVE PASSES NORTH
OF THE AREA.
OUTLOOK...A WEAK UPPER DISTURBANCE WILL SLIDE THROUGH THE REGION ON
THURSDAY WITH LITTLE/NO IMPACT EXPECTED. ANOTHER MORE ORGANIZED
SYSTEM WILL APPROACH FROM THE WEST FOR THE START OF THE WEEKEND ONCE
AGAIN INCREASING PRECIP/RESTRICTION CHANCES. SOME WINTRY PRECIP IS
POSSIBLE ACROSS THE NC MOUNTAINS/FOOTHILLS AFFECTING BOTH KAVL AND
KAND SATURDAY MORNING. WINTRY PRECIP IS NOT EXPECTED AT THIS TIME
FOR ANY OTHER TAF SITES.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...CDG/JOH
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...JOH