Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/17/14
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
801 PM CST THU JAN 16 2014
.DISCUSSION...
759 PM CST
FORECAST ADJUSTMENTS FOR TONIGHT HAD BEEN TO INCREASE WIND
SPEEDS...ALONG WITH SOME TIGHTENING/REFINING OF SNOW SHOWER CHANCES.
THE GENERAL TREND FOR TONIGHT REMAINS...WITH A LARGE PART OF THE
CWA FAVORED ONLY TO EXPERIENCE FLURRIES.
THE MASSIVE UPPER TROUGH NOW OVER 2000 MILES IN DIAMETER IS
BASICALLY CENTERED JUST NORTH OF THE AREA THIS EVE. THIS TROUGH
HOWEVER IS NOT MADE OF ONE DISTINCTIVE CENTER...WITH A PLETHORA
OF WELL-DEFINED VORTS ROTATING AROUND EACH OTHER. SOME OF THESE
SEEM TO BE DEMONSTRATING ALMOST A FUJIWARA EFFECT...AND LIKELY
RESULTING IN AREAS OF FOCUSED SNOW SHOWERS WHERE YOU WOULDNT
NORMALLY THINK. FOR INSTANCE...THE RECENT INCREASE IN SNOW SHOWERS
ACROSS THE NORTH CHICAGO METRO HAS THE NATURE OF FRONTOGENETIC
FORCED PRECIP...AND THAT THERMAL GRADIENT LOOKS TO BE TIGHTENING
BETWEEN TWO VORTS /ONE OVER WESTERN WI AND ONE OVER SOUTHERN LAKE
MI/. THE WARM SIDE OF THE THERMAL GRADIENT IS ACTUALLY BACK TO THE
NORTHEAST AND THAT IS WHERE THE SNOW HAS DEVELOPED. WHILE THIS
LOOKS TO BE MOVING ALONG AT A GOOD RATE...SNOW OF 25DBZ HAVE BEEN
SEEN IN POCKETS...WHICH COULD RESULT IN EVE ACCUMS OF ONE HALF TO
ONE INCH IN PARTS OF NORTHERN AND EASTERN LAKE COUNTY.
ANOTHER UNIQUE AREA CAUSED BY A DIGGING SHORT WAVE ACROSS IA IS A
LOW-LEVEL CIRCULATION CENTER NOW ACROSS WEST CENTRAL IL AND MOVING
EAST SOUTHEAST. THIS RESULTED IN 1/8SM VISIBILITY IN HEAVY
THUNDERSNOW AND 46 KT WINDS AT DES MOINES A FEW HOURS AGO...AND
THAT CONTINUED FOR A SWATH ESE FROM THERE. THIS HAS SLOWLY
WEAKENED...BUT STILL WELL-DEFINED FOR SNOW SHOWERS. BELIEVE THAT
THE FAR SOUTHERN CWA...FROM LIVINGSTON TO BENTON COUNTIES...WILL
BE AT LEAST GRAZED BY THIS MESOSCALE FEATURE...RESULTING IN SOME
LIGHT TO MODERATE SNOW SHOWERS. THE MORE ROBUST SNOW SHOWERS AND
INDUCED GUSTINESS IS MORE LIKELY ALONG THE I-74 CORRIDOR. IN
ADDITION...AS THE AFOREMENTIONED IA IMPULSE WRAPS EASTWARD INTO
CENTRAL IL...IMPROVED MID-LEVEL FORCING ACROSS THE SOUTHERN CWA
MAY CONTINUE SCATTERED SNOW SHOWERS INTO OVERNIGHT. SOME HIGH RES
GUIDANCE SUPPORTS THIS AND HAVE LINGERED POPS A LITTLE LONGER
AFTER THE HIGHER POPS PRIOR TO MIDNIGHT.
BETWEEN THESE TWO AREAS...WHICH IS A LOT OF THE CWA...CONTINUE
WITH NO POPS FOR MUCH OF THE NIGHT.
TEMPS WILL CONTINUE TO FALL...WITH MORE OF A PROGRESSIVE DROP
ACROSS THE NORTHERN HALF OF THE CWA AS THE COLD AIR PINWHEELS
AROUND THE SURFACE LOW WHICH IS ACROSS CENTRAL LAKE MI. WITH
HIGHER WIND SPEEDS IN THE FORECAST...SIMPLY FAVORED BY THE COLD
AIR ADVECTION AND TIGHT TRANSITIONING PRESSURE GRADIENT...FORECAST
WIND CHILLS ARE NOW 8 TO 16 BELOW ZERO ACROSS A LARGE PART OF THE
CWA OVERNIGHT INTO VERY EARLY FRIDAY MORNING.
MTF
&&
.PREV DISCUSSION...
255 PM CST
THE STORY THROUGH THE REMAINDER OF THE WEEK AND INTO THE WEEKEND
WILL BE NORTHWEST FLOW WITH A NUMBER OF DISTURBANCES BRINGING
PERIODIC CHANCES FOR SNOW AND FLUCTUATING TEMPERATURES.
THIS AFTERNOON...
SURFACE LOW IS CENTERED OVER THE UPPER PENINSULA OF MICHIGAN WITH A
COLD FRONT SWEEPING ACROSS NORTHERN ILLINOIS. WIDESPREAD SNOW
SHOWERS CONTINUE ACROSS NORTHERN ILLINOIS THIS AFTERNOON WITH SOME
AREAS RECEIVING A FEW TENTHS OF SNOW ACCUMULATION. DRIER AIR QUICKLY
MOVES IN BEHIND THE FRONT...SO EXPECT SHOWERS TO TAPER WEST TO EAST
MID TO LATE THIS EVENING ACROSS THE FORECAST AREA...WITH DRY
CONDITIONS PREVAILING OVERNIGHT FOR MOST AREAS. THE ONLY CONCERN FOR
SNOW TONIGHT WOULD BE SOUTH OF I-80 WHERE A COMPACT UPPER LEVEL
DISTURBANCE WILL DIG INTO CENTRAL ILLINOIS. IT APPEARS THAT SNOW
WITH THIS WAVE WILL PRIMARILY REMAIN SOUTH OF THE CWA THOUGH...SO
ONLY MENTION AN 20 PERCENT CHANCE LATE THIS EVENING. IMMEDIATELY
BEHIND THE FRONT...VERY GUSTY CONDITIONS ARE BEING OBSERVED UPSTREAM
WITH GUSTS INTO THE LOW TO MID 30 KT RANGE POSSIBLE FOR AN HOUR OR
TWO...THEN TAPERING BACK IN TO THE 20 KT RANGE OVERNIGHT.
TEMPERATURES SHOULD PLUMMET TOWARDS THE SINGLE DIGITS OVERNIGHT WITH
A DECENT PUSH OF COLD AIR INTO THE AREA. EXPECT TO REACH INTO THE
LOW TO MID SINGLE DIGITS WEST OF THE FOX RIVER VALLEY...AND HIGH
SINGLE DIGITS AROUND TO TO THE EAST.
FRIDAY...
REINFORCING SHOT OF COLD AIR WILL PIVOT ACROSS WESTERN/SOUTHERN
PORTIONS OF THE CWA EARLY FRIDAY WITH THE POOL OF COLDEST H85 AIR
JUST UNDER -20C. MAIN UPPER TROUGH AXIS WILL SHIFT EAST OF THE AREA
WITH BROADSCALE HEIGHT RISES OVERSPREADING THE AREA THROUGH THE DAY.
SEVERAL EMBEDDED SHORTWAVES PIVOTING AROUND THE MAIN TROUGH
AXIS...INCLUDING ONE THAT PROGGED TO COME ACROSS THE AREA FRIDAY
AFTERNOON WILL BRING ADDITIONAL CHANCES FOR PRECIP. THE AREA WILL BE
WELL ENTRENCHED IN THE COLD AIR WITH LOW LEVEL CYCLONIC FLOW KEEPING
SATURATED CONDITIONS DOWN LOW. THIS ALONG WITH DEEP SNOW GROWTH ZONE
AND WEAK OMEGA ASSOCIATED WITH THE SHORTWAVE...AND DESPITE THE
LARGER SCALE SUBSIDENCE...SHOULD SUPPORT SOME LIGHT SNOW AND
FLURRIES...WITH A DUSTING TO MAYBE AROUND HALF AN INCH ON THE HIGH
SIDE POSSIBLE.
SATURDAY...
LATE IN THE WEEK INTO THE WEEKEND A 130-140KT JET WILL BEGIN TO DIG
ACROSS THE CANADIAN PRAIRIES AND NORTHERN PLAINS WITH A POTENT UPPER
WAVE CLOSING OFF AT H5 AS IT MOVES INTO THE UPPER MIDWEST SATURDAY.
MODELS INDICATE THAT THE SURFACE LOW WILL TRACK SE SOMEWHERE ACROSS
ILLINOIS...THOUGH STILL SEE SOME SPREAD IN THE TRACK AND RESULTING
SWATH OF HEAVIEST SNOW. NCEP GUIDANCE PAINTS THE MOST PESSIMISTIC
PICTURE FOR NORTH/NORTHEAST ILLINOIS WITH BOTH GFS/NAM INDICATING A
SWATH OF AROUND A QUARTER INCH OF QPF ACROSS PORTIONS OF THE CWA.
THE 00Z ECMWF HAD A TRACK FARTHER NORTH...BUT 12Z CAME IN MORE IN
LINE WITH THE GFS/NAM. LATEST THINKING IS FOR SEVERAL INCHES OF
ACCUMULATING SNOWFALL ACROSS FAR NORTHEASTERN ILLINOIS AND FAR
NORTHWEST INDIANA INCLUDING THE CHICAGO METRO...WITH AMOUNTS
TAPERING TO AN INCH OR TWO AS YOU GO SW TOWARDS CENTRAL ILLINOIS.
SUNDAY THROUGH THURSDAY...
LARGE SCALE PATTERN REMAINS RELATIVELY UNCHANGED WITH BROAD
TROUGHING ACROSS THE EASTERN CONUS WITH STRONG RIDGE ALONG THE WEST
COAST INTO ALASKA. SURFACE HIGH SHOULD LEAD TO A RELATIVE LULL IN
THE PRECIPITATION CHANCES SUNDAY AND AT LEAST EARLY INTO MONDAY.
DEEPENING UPPER LOW OVER NORTHERN CANADA WILL DISLODGE ARCTIC
AIRMASS SOUTHWARD ACROSS CANADA AND INTO THE GREAT LAKES REGION
MONDAY. CHANCE FOR SNOW WILL RETURN MONDAY AS THE COLD FRONT SWEEPS
SOUTH ACROSS THE AREA...BUT POSSIBLY THE BIGGER STORY WILL BE THE
RETURN OF THE COLD. WHILE THE COLDEST H85 AIR OF -25 TO -30C SHOULD
STAY ACROSS THE NORTHERN LAKES REGION...MODELS IN DECENT AGREEMENT
THAT -20C AIR WILL SINK ACROSS ILLINOIS...PERSISTING THROUGH
MIDWEEK. BUMPED TEMPERATURES DOWN FROM MONDAY ON...AND CONCERNED
THAT TEMPS MAY STILL BE TOO WARM EARLY TO MID NEXT WEEK.
BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* GUSTY WEST-NORTHWEST WINDS TO 30 KT EARLY THIS EVENING GRADUALLY
DIMINISHING OVERNIGHT.
* RAPID IMPROVEMENT TO VFR CONDITIONS EARLY THIS EVENING.
* CHANCE OF LIGHT SNOW WITH MVFR CIG/VIS DURING THE DAY FRI.
* WEST WINDS GUSTING 15-20 KT FRI.
RATZER
//DISCUSSION...UPDATED 00Z...
COLD FRONT PUSHING THROUGH CHICAGO TERMINALS AT THIS HOUR WITH
WINDS NOW WEST-NORTHWEST AND GUSTING AROUND 30 KT. SNOW ENDING
WITH INTRUSION OF MUCH DRIER AIR BEHIND FRONT...WITH RAPID
IMPROVEMENT IN CIGS/VIS TO VFR CONDITIONS EXPECTED WITHIN THE
NEXT 1-2 HOURS. WINDS SHOULD BE 280-310 DEG THROUGH THE EVENING
WITH SPEEDS SLOWLY EASING LATE EVENING/OVERNIGHT.
ANOTHER MID-LEVEL DISTURBANCE AND ASSOCIATED SURFACE TROUGH WILL
MOVE SOUTHEAST ACROSS THE AREA FRIDAY...WITH THE POTENTIAL FOR
ANOTHER PERIOD OF LIGHT SNOW WITH MVFR CIG/VIS CONDITIONS FRIDAY.
FORCING IS RELATIVELY WEAK WITH THIS WAVE...THOUGH LOW/MID LEVEL
MOISTENING AND GOOD SNOW FLAKE GROWTH THERMAL PROFILE INDICATES
POTENTIAL FOR VIS REDUCTION AND MINOR ACCUMULATION. FLURRIES MAY
BEGIN IN RFD A FEW HOURS BEFORE SUNRISE...CHICAGO AFTER SUNRISE.
BEST POTENTIAL FOR 2-3SM VIS AND ACCUMULATION LOOKS TO BE ROUGHLY
12Z-20Z AT RFD...15Z-21Z ACROSS CHICAGO TAF SITES WHEN MODELS
DEPICT WEAK MOIST ASCENT. FLURRIES MAY LINGER INTO THE EVENING
WITH MVFR STRATOCU DECK REMAINING IN FAVORABLE THERMAL PROFILE FOR
SNOWFLAKE PRODUCTION...THOUGH WITH ASCENT WEAKENING SIGNIFICANTLY
BY LATE AFTERNOON.
WEST WINDS WILL CONTINUE TO DECREASE THROUGH EARLY FRIDAY...WITH
GUSTS GENERALLY 15-20 KT FRIDAY. DIRECTION EXPECTED TO BACK TO
260-270 DEG BY MORNING...THEN SUBTLY SHIFT BACK 280-290 DEG LATE
IN THE DAY.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH CONFIDENCE IN WIND TRENDS THROUGH PERIOD.
* HIGH CONFIDENCE IN IMPROVEMENT TO VFR THIS EVENING.
* MEDIUM CONFIDENCE IN VIS/CIG IN LIGHT SNOW AND TIMING OF LOWER
CONDITIONS FRI.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...SNOW AND IFR. LIFR POSSIBLE.
SUNDAY...VFR.
MONDAY...SLIGHT CHANCE OF LIGHT SNOW. MVFR/ BRIEF IFR POSSIBLE.
TUESDAY AND WEDNESDAY...MAINLY VFR.
RATZER
&&
.MARINE...
300 PM...A SERIES OF CLIPPERS WILL IMPACT THE GREAT LAKES REGION
OVER THE NEXT SEVERAL DAYS. THIS WILL BRING PERIODS INCREASING AND
DECREASING WINDS OF VARIABLE DIRECTION WILL NO EXTENDED PERIOD OF
A STEADY STATE CONDITION. THE FIRST LOW...OVER WESTERN LAKE
SUPERIOR...WILL WEAKEN AS IT DROPS ACROSS NORTHERN LAKE MICHIGAN
TONIGHT SHIFTING WINDS FROM SWLY TO NWLY. THIS LOW WILL CONTINUE
TO WEAKEN AS IT MOVES EAST TO LAKE HURON FRIDAY AFTERNOON AND THEN
INTO SOUTHERN QUEBEC SATURDAY MORNING. ANOTHER LOW WILL DROP OUT
OF NORTHERN ALBERTA LATE TONIGHT AND DEEPEN AS IT MOVES THROUGH
MINNESOTA SATURDAY MORNING. THIS LOW WILL WEAKEN AS IT TRACKS
THROUGH NORTHERN ILLINOIS SATURDAY AFTERNOON AND DISSIPATE AS IT
REACHES THE EASTERN GREAT LAKES SUNDAY. MEANWHILE...YET ANOTHER
LOW IS EXPECTED TO DEVELOP OVER NORTHERN MANITOBA FRIDAY NIGHT AND
DROP SOUTHEAST ACROSS ONTARIO SATURDAY NIGHT WHILE DEEPENING. A
COLD FRONT ASSOCIATED WITH THIS LOW WILL SWEEP ACROSS LAKE
MICHIGAN SUNDAY AND SUNDAY NIGHT AS THE PARENT LOW CONTINUES EAST
INTO QUEBEC. WEST WINDS MAY APPROACH GALE FORCE ON SUNDAY AHEAD OF
THE COLD FRONT.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...NEARSHORE WATERS UNTIL
MIDNIGHT FRIDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...MIDNIGHT FRIDAY TO 4 PM FRIDAY.
GALE WARNING...LMZ080-LMZ777-LMZ779-LMZ878 UNTIL 3 AM FRIDAY.
&&
$$
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WWW.TWITTER.COM/NWSCHICAGO
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
636 PM CST Thu Jan 16 2014
.DISCUSSION...
ISSUED 636 PM CST Thu Jan 16 2014
Made some major revisions to the evening forecast package, as we
are watching a robust upper-wave currently over eastern Iowa
approach from the northwest. This feature is producing a small
area of moderate to heavy snowfall, followed by very strong
northwesterly winds. Upstream obs have shown visbys reduced to
less than 1/4 mile at times coupled with winds gusting to between
40 and 45 mph. Based on satellite/radar loops, it appears these
conditions will spread into the Illinois River Valley from the
Peoria area southward after 8 PM and should reach the I-55
corridor by around 9 PM. The vort max track suggests accumulating
snow will be focused across the heart of central Illinois south of
the I-74 corridor from late this evening into the wee hours of the
morning. Totals will generally be around 1 inch, with isolated
higher amounts approaching 2 inches in a few spots. The very
strong winds combined with the snow will create low visibilities
and dangerous driving conditions as the system moves through. Have
issued a Special Weather Statement (SPS) to highlight the hazards.
Once the wave passes, strong northwesterly winds will prevail for
the remainder of the night. With lows falling into the single
digits and teens, wind-chill readings will drop into the zero to
10 below zero range after midnight.
Barnes
&&
.AVIATION...
ISSUED 554 PM CST Thu Jan 16 2014
Vigorous short-wave over central Iowa will track E/SE across
central Illinois this evening, accompanied by a brief period of
moderate to heavy snow followed by very strong northwesterly winds.
Based on track of system, it appears mainly KSPI and KDEC will be
impacted by this system, while the snow largely misses the I-74
terminals. Timing tools and latest HRRR data suggest snow with
visbys down to around 1/2SM will impact KSPI between 03z and 05z,
then further east to KDEC between 04z and 06z. Once the snow ends,
very strong northwesterly winds gusting to around 35kt will occur
for 2 to 3 hours before gradually subsiding to around 25kt late
tonight. After that, MVFR ceilings and gusty northwesterly winds
will prevail on Friday. Scattered snow-showers and/or flurries
will be possible as well, but will leave out of forecast for now.
Barnes
&&
.PREV DISCUSSION...
ISSUED 300 PM CST Thu Jan 16 2014
Periods of snow from various clipper systems will highlight the
short term. Southern areas will be under the potential for
measurable snow tonight. Nuisance snow showers will affect the
north Friday, then up to an inch of snow will hit mainly northern
areas on Saturday into Sat eve. As is common with multiple clipper
scenarios, the models generally differ on placement and timing of
the shortwaves. We kept the general theme of the forecast and
bumped up PoPs for tonight in the S and also on Sat in the north
where confidence for measurable snow has increased. Used more of a
GFS/ECMWF blend for the forecast updates.
SHORT TERM...Tonight through Sunday.
A cold front pushing across Illinois late this afternoon and
evening will be accompanied by a couple of shortwaves. One
circulation will advance across the northern half of the KILX CWA
into this evening, while a secondary trough and shortwave in Iowa
will advance into our S counties tonight. Snow accumulation for
these features will range from a dusting in the north to up to an
inch from Jacksonville and Springfield to Effingham and Flora. The
warm temperatures that have developed just ahead of the cold front
have allowed some light rain to mix in across western areas, but
the colder air advancing into the area will help to change all
precip to snow by early evening.
Gusty W-NW winds will make any snowfall lower the visibility,
especially during any periods of moderate snowfall in our SW and S
areas. North-South roads may have extra travel difficulties due to
the cross-wind and slippery conditions. Snow amounts will remain
below advisory criteria of 3", but travel hazards will be present
through tonight as temps drop and untreated road surfaces
potentially freeze over. Also, wind chills by Friday morning will
be -5F to -10F north of I-70.
The upper trough axis and center of the cold pool will settle
into IL tonight and Friday, with a couple of shortwaves rounding
the base of the trough during that time. Various snow showers or
flurries will affect most of the area Friday, with minimal
additional accumulation if any develops. A few tenths of an inch of
snow may develop in the morning SE of I-70, and through the day
north of I-74, per the GFS and ECMWF.
A more significant clipper is projected for Saturday, but the path
of the low center remains in question. The NAM has a farther N
track over Chicago at 6 pm Sat, while the GFS/ECMWF/Canadian GEM
are all farther south, over the Champaign/Danville area at 6 pm
Saturday. The NAM is still generous with snowfall production into
central IL like the other solutions, which added to the increasing
confidence of potential for snow accum.. We added likely PoPs
across the NE third of our counties Sat afternoon, north of a
line from Canton to Lincoln to Paris. That area could see up to an
inch of snow, with NW winds increasing Sat night behind the
departing clipper blowing the snow around.
Snows will come to an end by Sunday morning. The cold pool will
also begin to slide east on Sunday, with 850mb temps climbing from
zero to -3C at 12z/6am to +4 to 7C by 00z/6pm. High temps should
climb into the low 40s near Jacksonville to the mid 30s toward
CMI.
LONG TERM...Monday through Thursday.
Differences in the track of another low pressure system on Monday
could have a large impact on temperatures. The Canadian moves the
system like a clipper over the Great Lakes, delaying a cold
frontal passage until Monday night. The GFS/EC take low pressure
into northern IL and bring the colder air into our area sooner,
keeping Monday`s highs on the colder side. We trended a little
colder to coincide with the GFS/EC solution. We cant rule out some
light snow with that frontal passage, but chances of measurable
snow appear low due to limited moisture, so the forecast was kept
dry for now.
There appears to be some agreement on a shortwave clipping
northern IL Monday night, so we kept some slight chance PoPs in
the NE during that time period. Dry conditions should return on
Tuesday as very cold high pressure builds into the Midwest.
Temperatures will dip below normal from Tue through Thursday, with
the coldest night being Tuesday night. Air temps may drop between
zero and 5 above in our far north. Some improvement in temps will
close out the week, but it will remain unseasonably cold.
Yet another clipper is forecast for either Wednesday /GFS/ or
Thursday /ECMWF/. The end of the forecast was kept dry for now
until better agreement develops.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1016 AM EST WED JAN 15 2014
.UPDATE...
ISSUED AT 958 AM EST WED JAN 15 2014
THE GRIDS AND ZFP WERE UPDATED BASED ON RECENT OBSERVATION AND RADAR
TRENDS. THE BAND OF SNOW CONTINUES TO EXIT PIKE COUNTY WITH A FEW
SNOW SHOWERS LINGERING BACK TO THE SOUTHWEST OVER HARLAN AND LETCHER
COUNTIES. THESE SHOULD MOVE INTO VA WV WITHIN THE NEXT HALF HOUR TO
AN HOUR. A LULL IS THEN ANTICIPATED IN ANY SNOW SHOWER OR FLURRY
ACTIVITY UNTIL A MID LEVEL TROUGH APPROACHES THE REGION AND LEADS TO
STEEPER LAPSE RATES. RADAR RETURNS ARE UPSTREAM NEAR THE OH RIVER AND
OVER PARTS OF INDIANA. SOME VISIBILITIES HAVE BEEN DOWN BELOW 4 SM
OVER INDIANA AND AS THESE ROTATE TOWARD THE REGION THE ACTIVITY WILL
PROBABLY BE A CONSIDERABLE AMOUNT OF FLURRIES WITH SOME SNOW SHOWERS
AS WELL. HAVE OPTED TO GO WITH ISOLATED SNOW SHOWERS VERSUS JUST
SCATTERED OR ISOLATED FLURRIES FOR WEATHER THIS AFTERNOON. THE 12Z
NAM AND RECENT HRRR RUNS ARE ESSENTIALLY DRY HOWEVER. TEMPERATURES
SHOULD NOT RISE MUCH...BUT WILL GO UP AND DOWN AS BREAKS IN THE CLOUD
COVER AND BANDS OF CLOUDS WORK OVERHEAD.
UPDATE ISSUED AT 640 AM EST WED JAN 15 2014
FORECAST LOOKING GOOD SO FAR THIS MORNING. A BAND OF SNOW SHOWERS
THAT HAS BEEN MOVING ACROSS EASTERN KENTUCKY MOST OF THE NIGHT WILL
FINALLY BE EXITING THE AREA BETWEEN 12 AND 14Z THIS MORNING. AFTER A
BRIEF REPRIEVE...FLURRIES AND SNOW SHOWERS THAT ARE CURRENTLY MOVING
ACROSS THE OHIO RIVER OUT OF INDIANA...MAY MAKE THERE WAY ACROSS
EASTERN KENTUCKY LATER THIS MORNING. THE GRIDS REFLECT THIS
ALREADY...WITH FLURRIES POSSIBLE EARLY THIS MORNING...AND ISOLATED
SNOW SHOWERS POSSIBLE IN THE FAVORED UPSLOPE TERRAIN THIS AFTERNOON
AND EVENING. LITTLE IF ANY ACCUMULATION IS EXPECTED.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 354 AM EST WED JAN 15 2014
WILL BE ISSUING THE NEW FORECAST PACKAGE AND HAZARDOUS WEATHER
OUTLOOK IN THE NEXT LITTLE BIT. BASED ON CURRENT MODEL DATA...MAINLY
FROM THE SREF AND GFS...DECIDED TO TAKE PRECIPITATION OUT OF THE AREA
BY 11 OR 12Z THIS MORNING. EXPECTING SOME SNOW FLURRIES AND A FEW
SNOW SHOWERS TO FORM ACROSS THE AREA BY 15 OR 16Z TODAY...AS A WEAK
WAVE OF LOW PRESSURE MOVES OUT OF THE WESTERN GREAT LAKES AND SINKS
SOUTHEASTWARD ACROSS THE OHIO VALLEY. LITTLE IF ANY ACCUMULATIONS ARE
EXPECTED FROM THESE FLURRIES AND SHOWERS. THE SNOW SHOULD BE COMING
TO AN END AROUND 0Z THIS EVENING AS THE SHORT WAVE MOVES OFF TO THE
EAST OF THE AREA. THE WEATHER LOOKS TO BE COLD AND DRY TONIGHT AND
MOST OF THE DAY ON THURSDAY...AS A WEAK AREA OF HIGH PRESSURE BRIEFLY
SETTLES OVER THE AREA. ANOTHER MORE VIGOROUS WAVE OF LOW PRESSURE
SHOULD BEGIN SPREADING A FEW RAIN AND SNOW SHOWERS ACROSS THE AREA
THIS EVENING. TODAYS HIGHS WILL LIKELY NOT MAKE IT OUT OF THE LOWER
30S...AS CLOUD COVER WILL BE SLOW TO BREAK UP...AND WITH WEST TO
NORTHWEST WINDS BRINGING COLDER AIR INTO THE AREA. TONIGHTS LOWS WILL
BE QUITE COLD...WITH THE MERCURY DIPPING INTO THE MID TO UPPER TEENS
ACROSS THE AREA...AS A VERY COLD AIR MASS SETTLES OVER THE REGION
OVERNIGHT. WINDS WILL BE STRONGER AND MORE GUSTY ON THURSDAY THAN
TODAY...AS THE PRESSURE GRADIENT TIGHTENS ACROSS THE AREA AS THE
SHORTWAVE APPROACHES FROM THE NORTHWEST. HIGHS ON THURSDAY SHOULD BE
A BIT WARMER...AS CLOUDS WILL BE SCATTERED EARLY ON AND WINDS WILL BE
OUT OF THE SOUTH THROUGHOUT THE DAY. HIGHS ON THURSDAY WILL CLIMB TO
BETWEEN 36 AND 41 DEGREES ACROSS EASTERN KENTUCKY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 451 AM EST WED JAN 15 2014
ALTHOUGH FAR FROM PERFECT...MODELS HAVE COME INTO MUCH BETTER
AGREEMENT FOR THE PERIOD. ANOTHER COLD FRONT...ACCOMPANIED BY A
SHORTWAVE TROUGH...WILL MOVE EAST OVER THE REGION ON THURSDAY NIGHT
INTO FRIDAY. FORECAST SOUNDINGS SHOW A MOIST LAYER WITH STEEP LAPSE
RATES EXTENDING TO BETWEEN -15 AND -20 AT 8KT FT MSL. THIS WOULD
FAVOR SNOW SHOWERS AND HAVE USED 40-50 PERCENT POPS. MOS IS SHOWING
EVEN HIGHER POP VALUES...AND IF THIS PERSISTS...THE FORECAST POP MAY
NEED TO BE RAISED IN FUTURE UPDATES. AFTER A LULL IN PRECIP LATE
FRIDAY NIGHT INTO SATURDAY...ANOTHER SHORTWAVE IMPULSE IS EXPECTED
TO DIVE SOUTHEAST TOWARD THE AREA ALONG WITH AN ASSOCIATED CLIPPER
TYPE SURFACE LOW. IT PRESENTS ANOTHER POSSIBILITY OF SNOW LATE
SATURDAY AND SATURDAY NIGHT. MOISTURE WILL BE LIMITED...AND THE
SURFACE LOW TRACK IS EXPECTED TO BE NEAR OR JUST NORTH OF THE LOCAL
AREA...WHICH WOULD PLACE THE GREATEST THREAT OF ACCUMULATING SNOW TO
OUR NORTH. ONCE THIS SYSTEM PASSES BY...THE UPPER LEVEL FLOW WILL
FLATTEN AND BECOME MORE ZONAL...WITH ANOTHER CORRESPONDING LULL IN
THE WEATHER. MODELS SHOW YET ANOTHER STRONG IMPULSE DROPPING IN FROM
THE NW BY LATE TUESDAY. THE INITIAL SURFACE LOW WITH THIS IS
EXPECTED TO BE WELL TO OUR NORTH...WITH SUBSEQUENT DEVELOPMENT OFF
THE EAST COAST. THIS WOULD NOT FAVOR MUCH PRECIP FOR THE FORECAST
AREA...BUT SNOW SHOWERS CAN NOT BE RULED OUT IN A STEEP LOW LEVEL
LAPSE RATE ENVIRONMENT AS COLDER AIR ARRIVES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 640 AM EST WED JAN 15 2014
A BAND OF LIGHT SNOW SHOWERS CONTINUES TO MOVE ACROSS EASTERN
KENTUCKY EARLY THIS MORNING. THESE SHOWERS ARE EXPECTED TO EXIT THE
AREA BETWEEN 12 AND 14Z. THE TAF SITES CAN EXPECT TO BE PRECIPITATION
FREE UNTIL LATER THIS MORNING AND THIS AFTERNOON...WHEN FLURRIES AND
ISOLATED SNOW SHOWERS MAY AFFECT THE AREA ONCE AGAIN. DUE TO THE
ISOLATED AND SCATTERED NATURE OF THE FLURRIES AND SNOW SHOWERS...THE
TAFS WILL ONLY REFLECT VCSH FROM 15Z ONWARD TODAY. MVFR CONDITIONS
WILL BE POSSIBLE AS THE LOW LEVEL CLOUD COVER THAT WILL SPAWN ANY
SNOW MOVES IN FROM THE WEST. WINDS SHOULD NOT BE MUCH OF AN ISSUE
TODAY...WITH WEST TO NORTHWEST FLOW OF 5 TO 15 MPH. THE SNOW SHOULD
BE ENDING ACROSS THE AREA BY 0Z THIS EVENING. TONIGHT LOOKS TO BE
QUIET AND DRY WITH VFR CONDITIONS EXPECTED. WINDS COULD BE A BIT
STRONGER TOMORROW...WITH SOUTHERLY FLOW OF 10 TO 15 AND GUSTS TO 25
MPH POSSIBLE...AS ANOTHER WEATHER SYSTEM APPROACHES FROM THE
NORTHWEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...AR
LONG TERM...HAL
AVIATION...AR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
648 AM EST WED JAN 15 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 453 AM EST WED JAN 15 2014
THE CLIPPER SYSTEM THAT BROUGHT THE SNOW TO THE SOUTH CENTRAL CWA
YESTERDAY CONTINUES TO PULL OUT OF THE REGION EARLY THIS MORNING
AND IS CURRENTLY OVER NORTHERN LAKE HURON AT 1002MB. MEANWHILE...A
HIGH PRESSURE RIDGE OF 1024MB OVER THE EASTERN DAKOTAS IS BEGINNING
TO SHIFT INTO WESTERN MINNESOTA. THE TIGHT GRADIENT BETWEEN THESE
TWO FEATURES AND RAP ANALYZED 850MB TEMPS OF -16C HAS LED TO LAKE
EFFECT SNOW OVER MOST OF THE NORTHERLY WIND FAVORED AREAS NEAR LAKE
SUPERIOR. THE STRONGEST LAKE EFFECT HAS BEEN OVER FAR EASTERN
MARQUETTE COUNTY AND WESTERN ALGER COUNTY...WHERE THERE HAS BEEN
INCREASED CONVERGENCE FROM THE DEPARTING SYSTEM AND GRADUALLY
BACKING WINDS. WITH THE STRONGER WINDS OF 27KTS AT STDM4...THESE
BANDS HAVE BEEN EASILY REACHING SOUTHERN DELTA/SCHOOLCRAFT COUNTIES.
WITH THE QUICK DEPARTURE OF THE LOW AND THE ARRIVAL OF THE
RIDGE...SHOULD SEE A VERY QUICK BACKING TREND TO THE WINDS OVER THE
WESTERN LAKE TODAY AND ALLOW THE REMAINING LAKE EFFECT TO PUSH
NORTHEAST ACROSS THE KEWEENAW PENINSULA AND OUT OVER THE OPEN LAKE
BY 21Z. OVER THE EAST HALF...THE BACKING WINDS WILL TAKE A LITTLE
BIT LONGER TO ARRIVE...BUT HAVE ALREADY STARTED TO SEE THEM BACK TO
THE NORTHWEST AT STANNARD ROCK AND GRANITE ISLAND. THUS...EXPECT THE
FOCUSED LAKE EFFECT OVER EASTERN MARQUETTE AND WESTERN ALGER COUNTY
TO CONTINUE TO AROUND OR SHORTLY BEFORE DAYBREAK AND THEN THE
INFLUENCE OF THE BACKING WINDS WILL TAKE HOLD AND STEADILY SHIFT THE
BANDS EASTWARD ACROSS ALGER COUNTY THROUGH THE DAY. 925MB WINDS LOOK
TO BE WEST OR WEST-SOUTHWEST AROUND 21Z AND SHOULD SEE THE LAST OF
THE SNOW SHOWERS MOVING AWAY FROM GRAND MARAIS AT OR SHORTLY AFTER
THAT TIME. WITH GUSTS TO 25-30KTS RIGHT ALONG THE LAKE SUPERIOR
SHORELINE...OPTED TO EXTEND THE ADVISORY FOR ANOTHER 3HRS (UNTIL
15Z) SINCE CONDITIONS ALONG M-28 WILL LIKELY BE POOR THIS MORNING.
FELT 15Z WAS A REASONABLE ENDING TIME SINCE THE WINDS WILL BE
DIMINISHING AND THE BANDS STARTING TO PUSH EAST. WILL ALSO ISSUE AN
SPS FOR EASTERN MARQUETTE COUNTY SHORTLY TO COVER M-28 EAST OF
HARVEY WITH THE BLOWING SNOW AND LAKE EFFECT.
THE NEXT CLIPPER SYSTEM TO AFFECT THE AREA IS CURRENTLY DROPPING
SOUTHEAST THROUGH SASKATCHEWAN AT THIS TIME AND WILL QUICKLY MOVE
SOUTHEAST THROUGH CANADA TODAY. THE INITIAL PUSH OF THE SHORTWAVE
WILL ARRIVE FROM WEST TO EAST THIS EVENING AND INTO THE OVERNIGHT
HOURS AND BRING THE FIRST WAVE OF SNOW WITH THIS SYSTEM. MODELS
CONTINUE TO VARY ON THE HANDLING OF THE LOW FOR THURSDAY...BUT THE
GENERAL IDEA OF THE LOW WILL BE LAGGING BEHIND AND MOVING OVER
WESTERN LAKE SUPERIOR AROUND 12Z THURSDAY SEEMS REASONABLE. THE
FIRST PUSH OF SNOW WILL BE ASSOCIATED WITH THE MAIN SHORTWAVE
ENERGY MOVING OVER THE WESTERN HALF OF THE CWA DURING THE EVENING
AND BECOMING A LITTLE MORE DIFFUSE AS IT MOVES OVER THE EASTERN
CWA. IN ADDITION TO THE SHORTWAVE...THERE IS A NARROW CORRIDOR OF
DEEP MOISTURE...850-500MB Q-VECTOR CONVERGENCE AND WARM AIR
ADVECTION...AND ISENTROPIC ASCENT ON THE 275-295K SURFACES. THIS
WOULD SUPPORT A NICE BAND OF LIGHT TO BRIEFLY MODERATE SNOW MOVING
ACROSS THE WESTERN CWA...BUT DUE TO THE NARROW AND QUICK MOVEMENT OF
THE FEATURES IT SHOULD ONLY LEAD TO A 3-4HR PERIOD OF SNOW AS IT
MOVES THROUGH. IN ADDITION...THE LATEST FORCING IN THE MODELS SEEMS
TO BE A LITTLE MORE SOUTHWEST AND FOCUSED NEAR GOGEBIC/IRON
COUNTIES BEFORE WEAKENING. RATIOS ARE TRICKY AS THE CLOUD LAYER IS
INITIALLY IN THE DGZ...BUT THEN MOVES TO THE BOTTOM OR BELOW AS THE
WARM AIR ADVECTION TAKES HOLD. IN ADDITION...THE STRONG WINDS IN
AND BELOW THE CLOUD LAYER MAY PRODUCE SOME FRACTURING AND LIMITING
RATIOS SOMEWHAT. OPTED TO GO HIGHER INITIALLY (16-18 TO 1) AND THEN
DROP TOWARDS 13 TO 1 AS THE WARM AIR SURGES IN AND THE SNOW
DIMINISHES.
OVER THE EAST...THAT AREA OF SNOW WILL SHOULD ARRIVE AROUND
MIDNIGHT...BUT THINK IT WILL BE ON A LITTLE BIT OF A DIMINISHING
TREND SINCE THE MODELS ARE SHOWING THE SHORTWAVE AND WAA BECOMING
WEAKER. ONE ITEM THAT COULD COUNTERACT SOME OF THIS WEAKENING IDEA
IS LAKE ENHANCEMENT OFF LAKE MICHIGAN WITH THE SOUTHWESTERLY WINDS.
AT LEAST INITIALLY...THERE IS SOME QUESTION IN HOW MUCH LOW LEVEL
MOISTURE WILL BE PRESENT DURING THE FIRST PART OF THE EVENING DUE TO
THE HIGH PRESSURE RIDGE. WOULD THINK THERE WOULD BE AT LEAST SOME
CLOUDS OR LIGHT SNOW SHOWERS SOUTHEAST OF A LINE FROM KISQ-KERY
BEFORE THE BETTER MOISTURE ARRIVES AND WINDS TURN A LITTLE MORE
SOUTH-SOUTHWESTERLY AND FOCUS THE LAKE ENHANCEMENT MORE INTO THE CWA
AROUND MIDNIGHT AND THROUGH MUCH OF THE REST OF THE NIGHT. 875MB
TEMPS STAY AROUND -14C FOR MUCH OF THE NIGHT...SO THERE IS DECENT
DELTA-T VALUES. DO HAVE A COUPLE CONCERNS ON HIGHER AMOUNTS AND IT
LARGELY HAS TO DO WITH THE SNOW RATIOS. FIRST...MUCH OF THE CLOUD IS
AT THE LOW END OF THE DGZ. SECOND...WITH THE STRONG WINDS IN THE
CLOUD LAYER...WOULD EXPECT THE DENDRITES THAT DO DEVELOP TO FRACTURE
ON THEIR WAY DOWN. BOTH OF THESE SHOULD LEAD TO RATIOS IN THE UPPER
TEENS.
12HR QPF FOR TONIGHT FROM THE MODELS IS GENERALLY BETWEEN 0.07-0.15
OF AN INCH FOR MUCH OF THE CWA AND USED A GENERAL MIDDLE GROUND FOR
THE FORECAST. THIS LEADS TO SNOWFALL AMOUNTS BETWEEN 1-2 INCHES
TONIGHT. DO HAVE SLIGHTLY HIGHER AMOUNTS OVER THE FAR EAST WHERE
THE LAKE ENHANCEMENT SHOULD PUSH AMOUNTS BETWEEN 2-3 INCHES. IN
ADDITION TO THE SNOW...THERE WILL BE GUSTY SOUTHWEST WINDS
(20-30MPH) THAT PRODUCE SOME BLOWING AND DRIFTING OF THE SNOW AND
MAY HELP REDUCE VISIBILITIES BELOW A MILE AS THE INITIAL SNOW MOVES
THROUGH. ALTHOUGH THE SNOW IS SUB ADVISORY...THE WIND PUSHES THE
CONCERN UP SOME FOR THAT SHORT PERIOD WHEN THE SNOW OCCURS. BUT
SINCE IT WILL ONLY BE A FEW HOUR PERIOD OF SNOW...DO NOT THINK THAT
IS ENOUGH TO WARRENT AN ADVISORY. IN ADDITION...WITH IT OCCURRING
DURING THE LATTER PART OF THE EVENING AND THROUGH THE OVERNIGHT
HOURS...THE SOCIETAL IMPACT WILL BE LIMITED. SINCE WORDING WOULD BE
SIMILAR TO WHAT IS IN THE HWO...WILL NOT ISSUE AN SPS.
ONCE THAT INITIAL WAVE OF PRECIP MOVES THROUGH...LOOKS LIKE THERE
WILL BE A MID LEVEL DRY SLOT THAT DIMINISHES OR ENDS THE SNOW FOR A
PERIOD BEFORE THE NEXT SHORTWAVE AND DEEPER MOISTURE WITH THE LOW
ARRIVES AFTER 09Z OVER THE WEST. THUS...HAVE CUT POPS BACK TO JUST
CHANCE WORDING OVER THE WEST AND MINIMAL ADDITIONAL ACCUMULATION.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 542 AM EST WED JAN 15 2014
LARGE SCALE PATTERN THROUGH THE EXTENDED CONSISTS OF A MEAN RIDGE
OVER WRN NORTH AMERICA WHILE A TROUGH DOMINATES DOMINATES MUCH OF
ERN NORTH AMERICA...INCLUDING THE GREAT LAKES. STRONGEST CLIPPER
SHORTWAVE MOVING THROUGH THE TROUGH CROSSES THE UPPER GREAT LAKES
WEDNESDAY NIGHT THROUGH EARLY FRIDAY. DAYTIME HIGHS WILL END UP
SLIGHTLY BLO NORMAL FOR MUCH OF THE TIME. ONE OF THE WARMEST DAYS OF
THE EXTENDED WILL BE ON THURSDAY AHEAD OF STRONGER COLD FRONT ASSOC
WITH INITIAL CLIPPER SHORTWAVE. BRIEF WARMING MAY OCCUR NEXT MONDAY
ONLY TO BE FOLLOWED BY ANOTHER CLIPPER SHORTWAVE AND BLAST OF ARCTIC
AIR ON TUESDAY.
THURSDAY AND FRIDAY...SYSTEM SNOW WILL GENERALLY BE TAPERING OFF THU
MORNING AS THE BEST WAA/ISENTROPIC LIFT BEGINS TO SHIFT EAST. ALSO
LAKE ENHANCED SNOW OVER THE ERN COUNTIES SHOULD BE TAPERING OFF BY
LATE THU MORNING AS OVERWATER INSTABILITY WEAKENS WITH WARMER TEMPS
-7C TEMPS MOVING OVER NRN LAKE MI. MODELS DIFFER ON EVOLUTION/TRACK
OF SFC LOW MOVING THROUGH THE CWA THU INTO THU NIGHT. THE GFS AND
ECMWF ARE DEEPER INITIALLY WITH THE SFC LOW THAN EITHER THE
NAM/GEM-NH OR UKMET. THE GFS/NAM AND UKMET TRACK THE SFC LOW ACROSS
UPPER MI ON THU WHILE THE ECMWF AND GEM-NH TAKE THE LOW JUST SOUTH
OF THE WI BDR. ALL MODELS NOW APPEAR TO SHOW THE LOW FILLING AS IT
TRACKS ACROSS THE UPPER GREAT LAKES ON THU AND THEN EAST OF THE
REGION FRI INTO FRI NIGHT. IT ALSO APPEARS THAT ALL THE MODELS ARE
TRENDING FARTHER WEST WITH HEART OF COLDEST 8H TEMPS (-20C OR
COLDER) MOVING THROUGH THE NRN AND CENTRAL PLAINS INSTEAD OF THE
UPPER GREAT LAKES REGION. THE COMBINATION OF THE WEAKENING SFC LOW
AND WEAKER OVERWATER INSTABILITY WITH FCST 8H TEMPS OF -15 TO 18C
WILL LIKELY RESULT IN LESS LAKE EFFECT SNOW AND BLOWING SNOW BEHIND
THE SYSTEM THAN ORIGINALLY THOUGHT. HOWEVER...THERE WILL STILL BE A
GOOD CHANCE FOR ADVISORY CRITERIA LAKE EFFECT SNOWFALL OVER THE WRN
CWA THU AFTERNOON INTO FRI MORNING...AND OVER THE NCNTRL COUNTIES
LATE THU NIGHT INTO FRIDAY WHEN THESE COLDER TEMPS SPREAD FROM WEST
TO EAST ACROSS LAKE SUPERIOR IN THE WAKE OF THE FRONTAL PASSAGE IN A
CYCLONIC CONVERGENT NRLY FLOW. A PERIOD OF GUSTY NRLY WINDS TO
PERHAPS TO 30 MPH IS STILL POSSIBLE...ESPECIALLY ALONG LAKE
SUPERIOR...WHICH COULD ALSO CAUSE CONSIDERABLE BLOWING AND DRIFTING
OF SNOW ALONG WITH LOWERED VSBY. WAS LEANING TOWARD ISSUING A SPS TO
HIGHLIGHT THE POTENTIAL FOR MODERATE LES AND BLOWING SNOW FOR WEST
AND NCNTRL COUNTIES THU AFTERNOON INTO FRI MORNING...BUT OPTED TO
STAY WITH HWO SINCE WORDING WOULD BE VERY SIMILAR.
BY THE TIME THE COLDEST 8H TEMPS REACH INTO THE ERN HALF OF THE LAKE
LATE FRI MORNING...THE NRLY FLOW WILL BE WEAKENING A BIT WITH LARGE
SCALE FLOW BECOMING INCREASINGLY ANTICYCLONIC FROM THE NORTH AND
WEST AS SFC RDG BEGINS TO BUILD IN FROM THE NRN PLAINS AND ONTARIO.
LAKE EFFECT SNOW WILL TAPER OFF QUICKLY FM THE WEST FRI AFTERNOON
INTO FRI EVENING AS SFC RDG BUILDS ACROSS THE AREA AND 8H TEMPS WARM
TO NEAR -12C. AN INCH OR TWO OF ADDITIONAL LES IS POSSIBLE OVER THE
ERN COUNTIES FRI NIGHT IN A LAND BREEZE ENHANCED CONVERGENT NW WIND
FLOW. PARTIAL CLEARING OVER THE WRN INTERIOR ALONG WITH LIGHT WINDS
UNDER SFC RDG SHOULD ALLOW TEMPS TO DIP INTO AT LEAST THE SINGLE
DIGITS BLO ZERO FRI EVENING. SOME INCREASE IN CLOUDS AND MAYBE EVEN
A DUSTING OF LIGHT SNOW IS POSSIBLE OVER THE WEST LATE FRI NIGHT AS
THE NEXT CLIPPER SYSTEM DIVES THROUGH THE NRN PLAINS.
SATURDAY AND SUNDAY...MODELS SHOW THE NEXT CLIPPER SYSTEM DIVING DOWN
THROUGH NRN MANITOBA AND NRN ONTARIO LATE SATURDAY AND SAT NIGHT.
IT/S QUESTIONABLE WHETHER INCREASING WEST WINDS AHEAD OF THIS SYSTEM
WILL GENERATE ANY LIGHT LES OVER THE KEWEENAW ON SAT AS 8H TEMPS
NEAR -12C MAY NOT BE COLD ENOUGH FOR SUFFICIENT OVER WATER
INSTABILITY. AS CLIPPER AND ASSOC SFC LOW MOVE NEAR JAMES BAY BY 12Z
SUN...MODELS SHOW LIGHT SYSTEM SNOW SPREADING INTO NRN AND ERN
SECTIONS OF THE CWA LATE SUN NIGHT ALONG AND AHEAD OF ADVANCING COLD
FRONT. A PERIOD OF LES IS LIKELY OVER THE NCNTRL AND ERN CWA ON
SUNDAY WITH CAA NW FLOW IN WAKE OF COLD FRONT.
SUNDAY NIGHT INTO TUESDAY...ECMWF AND GFS IN DECENT AGREEMENT
SHOWING A SERIES OF CLIPPER SHORTWAVES MOVING THROUGH FOR THE SUN
NIGHT INTO MON NIGHT TIME FRAME. THESE SHORTWAVES WILL BRING CHCS
FOR MORE LIGHT SYSTEM SNOW SUN NIGHT AND MONDAY WHILE USHERING IN A
MUCH COLDER AIRMASS FOR MONDAY NIGHT INTO TUESDAY AS THE ECMWF
INDICATES 8H TEMPS DROPPING TO NEAR -25C BY TUESDAY. EXPECT ANOTHER
ROUND OF LAKE EFFECT SNOW AND BLOWING SNOW MON NIGHT INTO TUESDAY
FOR N-NE LAKE SUPERIOR SNOWBELTS. INCREASINGLY COLDER AIRMASS WILL
RESULT IN FINE SNOWFLAKES BY TUESDAY AS THE DGZ GETS SQUASHED NEAR
THE LAKE SFC. THE FINE SNOWFLAKES WILL BE EFFECTIVE AT LOWERING VSBY
IN BLOWING SNOW. IT APPEARS THAT A SERIES OF CLIPPER SHORTWAVES WILL
CONTINUE TO REINFORCE ARCTIC AIRMASS THROUGH MUCH OF THE WORK WEEK
KEEPING TEMPS WELL BELOW NORMAL FROM TUE THROUGH AT LEAST THU WITH
LIGHT TO MODERATE LAKE EFFECT SNOW CONTINUING FOR THE NORTH WIND LAKE
SUPERIOR SNOWBELTS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 646 AM EST WED JAN 15 2014
A HIGH PRESSURE RIDGE WILL QUICKLY MOVE EAST OVER UPPER MICHIGAN
TODAY. DRIER AIR AND BACKING WINDS SHOULD DIMINISH THE LAKE EFFECT
FROM WEST TO EAST TODAY AND TREND CONDITIONS TO VFR. A CLIPPER
SYSTEM QUICKLY DIVING SOUTHEAST TOWARDS UPPER MICHIGAN TONIGHT WILL
PUSH A BAND OF LIGHT TO MODERATE SNOW ACROSS THE AREA. THIS
SNOW...COMBINED WITH GUSTY SOUTHWEST WINDS...WILL LEAD TO IFR
VISIBILITIES AT KCMX/KIWD FOR A COUPLE HOUR PERIOD THIS EVENING
INTO THE EARLY OVERNIGHT HOURS. THE SNOW WILL BE A LITTLE LATER TO
ARRIVE AT KSAW AND THERE IS SOME CONCERN OF A WEAKENING TREND AS IT
REACHES THE SITE. THUS...HAVE KEPT VISIBILITY AT LOW END MVFR FOR
NOW. BEHIND THIS INITIAL WAVE OF SNOW...EXPECT SCATTERED SNOW
SHOWERS AND MVFR CEILINGS ARE EXPECTED OVER UPPER MICHIGAN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 453 AM EST WED JAN 15 2014
A LOW CENTERED OVER CENTRAL LAKE HURON WILL DEPART THE GREAT LAKES
REGION TODAY...ALLOWING A HIGH PRESSURE RIDGE TO QUICKLY SLIDE OVER
LAKE SUPERIOR. THIS WILL LEAD TO WEAKENING WINDS THIS
MORNING...WHICH WILL THEN QUICKLY BACK TO THE SOUTHWEST AND
INCREASE THIS AFTERNOON AND EVENING AHEAD OF ANOTHER CLIPPER
SYSTEM. THINK THE SUSTAINED WINDS WILL BE IN THE 25-30KT RANGE OVER
THE WESTERN LAKE THIS EVENING WITH FREQUENT ENOUGH GUSTS TO 35
KNOTS TO SUPPORT ISSUING A GALE WARNING FOR ABOUT A 6-9HR PERIOD.
SINCE THE LOW WILL BE WEAKENING AS IT MOVES TOWARDS LAKE
SUPERIOR...AM A LITTLE UNCERTAIN ON HOW STRONG THE WINDS WILL BE
OVER THE EASTERN LAKE...BUT SHOULD SUPPORT AT LEAST SOME GALE FORCE
GUSTS TO 35KTS. THIS LOW WILL MOVE OVER WESTERN LAKE SUEPRIOR
OVERNIGHT AND DECREASE WINDS ACROSS THE LAKE. AS IT MOVES ACROSS
UPPER MICHIGAN ON THURSDAY AND SLOWLY WEAKENS...WINDS WILL TURN TO
THE NORTH FROM WEST TO EAST THURSDAY AFTERNOON THROUGH THURSDAY
NIGHT. THERE IS THE POTENTIAL FOR SOME GALES TO 35KTS ON THE BACK
SIDE OF THIS LOW...ESPECIALLY OVER WESTERN LAKE SUPERIOR WHEN THE
LOW IS STILL A LITTLE STRONGER. THIS LOW WILL DEPART THE AREA ON
FRIDAY AND ALLOW A WEAK HIGH PRESSURE RIDGE TO SLIDE ACROSS THE
LAKE FRIDAY AFTERNOON AND FRIDAY NIGHT. A COUPLE OTHER CLIPPER
SYSTEMS WILL BE NEAR THE GREAT LAKES REGION THIS WEEKEND. THE
STRONGEST ONE WILL MOVE THROUGH NORTHEAST ONTARIO ON SATURDAY NIGHT
AND DRAG A COLD FRONT ACROSS LAKE SUPERIOR LATE SATURDAY NIGHT AND
SUNDAY MORNING...WHICH WILL BRING ANOTHER POSSIBILITY OF NORTHWEST
GALES TO 35KTS.
HEAVY FREEZING SPRAY SHOULD DIMINISH THIS MORNING BUT THEN COME
BACK LATE THIS AFTERNOON AND EVENING. DID ISSUES A HEAVY FREEZING
SPRAY WARNING FOR THE WEST HALF OF THE LAKE TO ACCOUNT FOR THAT.
WHEN THE WINDS TURN NORTHERLY THURSDAY NIGHT INTO FRIDAY...SHOULD
SEE ANOTHER PERIOD OF HEAVY FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST THIS MORNING FOR
MIZ006.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
LSZ248>251-265>267.
GALE WARNING FROM 10 PM THIS EVENING TO 4 AM EST THURSDAY FOR
LSZ266-267.
HEAVY FREEZING SPRAY WARNING FROM 5 PM EST /4 PM CST/ THIS
AFTERNOON TO 1 AM EST /MIDNIGHT CST/ THURSDAY FOR LSZ162-
263-264.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR
LSZ244-245-263-264.
GALE WARNING FROM 7 PM THIS EVENING TO 1 AM EST THURSDAY FOR
LSZ263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...VOSS
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
543 AM EST WED JAN 15 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 453 AM EST WED JAN 15 2014
THE CLIPPER SYSTEM THAT BROUGHT THE SNOW TO THE SOUTH CENTRAL CWA
YESTERDAY CONTINUES TO PULL OUT OF THE REGION EARLY THIS MORNING
AND IS CURRENTLY OVER NORTHERN LAKE HURON AT 1002MB. MEANWHILE...A
HIGH PRESSURE RIDGE OF 1024MB OVER THE EASTERN DAKOTAS IS BEGINNING
TO SHIFT INTO WESTERN MINNESOTA. THE TIGHT GRADIENT BETWEEN THESE
TWO FEATURES AND RAP ANALYZED 850MB TEMPS OF -16C HAS LED TO LAKE
EFFECT SNOW OVER MOST OF THE NORTHERLY WIND FAVORED AREAS NEAR LAKE
SUPERIOR. THE STRONGEST LAKE EFFECT HAS BEEN OVER FAR EASTERN
MARQUETTE COUNTY AND WESTERN ALGER COUNTY...WHERE THERE HAS BEEN
INCREASED CONVERGENCE FROM THE DEPARTING SYSTEM AND GRADUALLY
BACKING WINDS. WITH THE STRONGER WINDS OF 27KTS AT STDM4...THESE
BANDS HAVE BEEN EASILY REACHING SOUTHERN DELTA/SCHOOLCRAFT COUNTIES.
WITH THE QUICK DEPARTURE OF THE LOW AND THE ARRIVAL OF THE
RIDGE...SHOULD SEE A VERY QUICK BACKING TREND TO THE WINDS OVER THE
WESTERN LAKE TODAY AND ALLOW THE REMAINING LAKE EFFECT TO PUSH
NORTHEAST ACROSS THE KEWEENAW PENINSULA AND OUT OVER THE OPEN LAKE
BY 21Z. OVER THE EAST HALF...THE BACKING WINDS WILL TAKE A LITTLE
BIT LONGER TO ARRIVE...BUT HAVE ALREADY STARTED TO SEE THEM BACK TO
THE NORTHWEST AT STANNARD ROCK AND GRANITE ISLAND. THUS...EXPECT THE
FOCUSED LAKE EFFECT OVER EASTERN MARQUETTE AND WESTERN ALGER COUNTY
TO CONTINUE TO AROUND OR SHORTLY BEFORE DAYBREAK AND THEN THE
INFLUENCE OF THE BACKING WINDS WILL TAKE HOLD AND STEADILY SHIFT THE
BANDS EASTWARD ACROSS ALGER COUNTY THROUGH THE DAY. 925MB WINDS LOOK
TO BE WEST OR WEST-SOUTHWEST AROUND 21Z AND SHOULD SEE THE LAST OF
THE SNOW SHOWERS MOVING AWAY FROM GRAND MARAIS AT OR SHORTLY AFTER
THAT TIME. WITH GUSTS TO 25-30KTS RIGHT ALONG THE LAKE SUPERIOR
SHORELINE...OPTED TO EXTEND THE ADVISORY FOR ANOTHER 3HRS (UNTIL
15Z) SINCE CONDITIONS ALONG M-28 WILL LIKELY BE POOR THIS MORNING.
FELT 15Z WAS A REASONABLE ENDING TIME SINCE THE WINDS WILL BE
DIMINISHING AND THE BANDS STARTING TO PUSH EAST. WILL ALSO ISSUE AN
SPS FOR EASTERN MARQUETTE COUNTY SHORTLY TO COVER M-28 EAST OF
HARVEY WITH THE BLOWING SNOW AND LAKE EFFECT.
THE NEXT CLIPPER SYSTEM TO AFFECT THE AREA IS CURRENTLY DROPPING
SOUTHEAST THROUGH SASKATCHEWAN AT THIS TIME AND WILL QUICKLY MOVE
SOUTHEAST THROUGH CANADA TODAY. THE INITIAL PUSH OF THE SHORTWAVE
WILL ARRIVE FROM WEST TO EAST THIS EVENING AND INTO THE OVERNIGHT
HOURS AND BRING THE FIRST WAVE OF SNOW WITH THIS SYSTEM. MODELS
CONTINUE TO VARY ON THE HANDLING OF THE LOW FOR THURSDAY...BUT THE
GENERAL IDEA OF THE LOW WILL BE LAGGING BEHIND AND MOVING OVER
WESTERN LAKE SUPERIOR AROUND 12Z THURSDAY SEEMS REASONABLE. THE
FIRST PUSH OF SNOW WILL BE ASSOCIATED WITH THE MAIN SHORTWAVE
ENERGY MOVING OVER THE WESTERN HALF OF THE CWA DURING THE EVENING
AND BECOMING A LITTLE MORE DIFFUSE AS IT MOVES OVER THE EASTERN
CWA. IN ADDITION TO THE SHORTWAVE...THERE IS A NARROW CORRIDOR OF
DEEP MOISTURE...850-500MB Q-VECTOR CONVERGENCE AND WARM AIR
ADVECTION...AND ISENTROPIC ASCENT ON THE 275-295K SURFACES. THIS
WOULD SUPPORT A NICE BAND OF LIGHT TO BRIEFLY MODERATE SNOW MOVING
ACROSS THE WESTERN CWA...BUT DUE TO THE NARROW AND QUICK MOVEMENT OF
THE FEATURES IT SHOULD ONLY LEAD TO A 3-4HR PERIOD OF SNOW AS IT
MOVES THROUGH. IN ADDITION...THE LATEST FORCING IN THE MODELS SEEMS
TO BE A LITTLE MORE SOUTHWEST AND FOCUSED NEAR GOGEBIC/IRON
COUNTIES BEFORE WEAKENING. RATIOS ARE TRICKY AS THE CLOUD LAYER IS
INITIALLY IN THE DGZ...BUT THEN MOVES TO THE BOTTOM OR BELOW AS THE
WARM AIR ADVECTION TAKES HOLD. IN ADDITION...THE STRONG WINDS IN
AND BELOW THE CLOUD LAYER MAY PRODUCE SOME FRACTURING AND LIMITING
RATIOS SOMEWHAT. OPTED TO GO HIGHER INITIALLY (16-18 TO 1) AND THEN
DROP TOWARDS 13 TO 1 AS THE WARM AIR SURGES IN AND THE SNOW
DIMINISHES.
OVER THE EAST...THAT AREA OF SNOW WILL SHOULD ARRIVE AROUND
MIDNIGHT...BUT THINK IT WILL BE ON A LITTLE BIT OF A DIMINISHING
TREND SINCE THE MODELS ARE SHOWING THE SHORTWAVE AND WAA BECOMING
WEAKER. ONE ITEM THAT COULD COUNTERACT SOME OF THIS WEAKENING IDEA
IS LAKE ENHANCEMENT OFF LAKE MICHIGAN WITH THE SOUTHWESTERLY WINDS.
AT LEAST INITIALLY...THERE IS SOME QUESTION IN HOW MUCH LOW LEVEL
MOISTURE WILL BE PRESENT DURING THE FIRST PART OF THE EVENING DUE TO
THE HIGH PRESSURE RIDGE. WOULD THINK THERE WOULD BE AT LEAST SOME
CLOUDS OR LIGHT SNOW SHOWERS SOUTHEAST OF A LINE FROM KISQ-KERY
BEFORE THE BETTER MOISTURE ARRIVES AND WINDS TURN A LITTLE MORE
SOUTH-SOUTHWESTERLY AND FOCUS THE LAKE ENHANCEMENT MORE INTO THE CWA
AROUND MIDNIGHT AND THROUGH MUCH OF THE REST OF THE NIGHT. 875MB
TEMPS STAY AROUND -14C FOR MUCH OF THE NIGHT...SO THERE IS DECENT
DELTA-T VALUES. DO HAVE A COUPLE CONCERNS ON HIGHER AMOUNTS AND IT
LARGELY HAS TO DO WITH THE SNOW RATIOS. FIRST...MUCH OF THE CLOUD IS
AT THE LOW END OF THE DGZ. SECOND...WITH THE STRONG WINDS IN THE
CLOUD LAYER...WOULD EXPECT THE DENDRITES THAT DO DEVELOP TO FRACTURE
ON THEIR WAY DOWN. BOTH OF THESE SHOULD LEAD TO RATIOS IN THE UPPER
TEENS.
12HR QPF FOR TONIGHT FROM THE MODELS IS GENERALLY BETWEEN 0.07-0.15
OF AN INCH FOR MUCH OF THE CWA AND USED A GENERAL MIDDLE GROUND FOR
THE FORECAST. THIS LEADS TO SNOWFALL AMOUNTS BETWEEN 1-2 INCHES
TONIGHT. DO HAVE SLIGHTLY HIGHER AMOUNTS OVER THE FAR EAST WHERE
THE LAKE ENHANCEMENT SHOULD PUSH AMOUNTS BETWEEN 2-3 INCHES. IN
ADDITION TO THE SNOW...THERE WILL BE GUSTY SOUTHWEST WINDS
(20-30MPH) THAT PRODUCE SOME BLOWING AND DRIFTING OF THE SNOW AND
MAY HELP REDUCE VISIBILITIES BELOW A MILE AS THE INITIAL SNOW MOVES
THROUGH. ALTHOUGH THE SNOW IS SUB ADVISORY...THE WIND PUSHES THE
CONCERN UP SOME FOR THAT SHORT PERIOD WHEN THE SNOW OCCURS. BUT
SINCE IT WILL ONLY BE A FEW HOUR PERIOD OF SNOW...DO THINK THAT IS
ENOUGH TO WARRENT AN ADVISORY. IN ADDITION...WITH IT OCCURRING
DURING THE LATTER PART OF THE EVENING AND THROUGH THE OVERNIGHT
HOURS...THE SOCIETAL IMPACT WILL BE LIMITED AND THUS WILL ISSUE A
AN SPS LATER THIS MORNING WITH INFO FOR THURSDAY INTO FRIDAY TOO.
ONCE THAT INITIAL WAVE OF PRECIP MOVES THROUGH...LOOKS LIKE THERE
WILL BE A MID LEVEL DRY SLOT THAT DIMINISHES OR ENDS THE SNOW FOR A
PERIOD BEFORE THE NEXT SHORTWAVE AND DEEPER MOISTURE WITH THE LOW
ARRIVES AFTER 09Z OVER THE WEST. THUS...HAVE CUT POPS BACK TO JUST
CHANCE WORDING OVER THE WEST AND MINIMAL ADDITIONAL ACCUMULATION.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 542 AM EST WED JAN 15 2014
LARGE SCALE PATTERN THROUGH THE EXTENDED CONSISTS OF A MEAN RIDGE
OVER WRN NORTH AMERICA WHILE A TROUGH DOMINATES DOMINATES MUCH OF
ERN NORTH AMERICA...INCLUDING THE GREAT LAKES. STRONGEST CLIPPER
SHORTWAVE MOVING THROUGH THE TROUGH CROSSES THE UPPER GREAT LAKES
WEDNESDAY NIGHT THROUGH EARLY FRIDAY. DAYTIME HIGHS WILL END UP
SLIGHTLY BLO NORMAL FOR MUCH OF THE TIME. ONE OF THE WARMEST DAYS OF
THE EXTENDED WILL BE ON THURSDAY AHEAD OF STRONGER COLD FRONT ASSOC
WITH INITIAL CLIPPER SHORTWAVE. BRIEF WARMING MAY OCCUR NEXT MONDAY
ONLY TO BE FOLLOWED BY ANOTHER CLIPPER SHORTWAVE AND BLAST OF ARCTIC
AIR ON TUESDAY.
THURSDAY AND FRIDAY...SYSTEM SNOW WILL GENERALLY BE TAPERING OFF THU
MORNING AS THE BEST WAA/ISENTROPIC LIFT BEGINS TO SHIFT EAST. ALSO
LAKE ENHANCED SNOW OVER THE ERN COUNTIES SHOULD BE TAPERING OFF BY
LATE THU MORNING AS OVERWATER INSTABILITY WEAKENS WITH WARMER TEMPS
-7C TEMPS MOVING OVER NRN LAKE MI. MODELS DIFFER ON EVOLUTION/TRACK
OF SFC LOW MOVING THROUGH THE CWA THU INTO THU NIGHT. THE GFS AND
ECMWF ARE DEEPER INITIALLY WITH THE SFC LOW THAN EITHER THE
NAM/GEM-NH OR UKMET. THE GFS/NAM AND UKMET TRACK THE SFC LOW ACROSS
UPPER MI ON THU WHILE THE ECMWF AND GEM-NH TAKE THE LOW JUST SOUTH
OF THE WI BDR. ALL MODELS NOW APPEAR TO SHOW THE LOW FILLING AS IT
TRACKS ACROSS THE UPPER GREAT LAKES ON THU AND THEN EAST OF THE
REGION FRI INTO FRI NIGHT. IT ALSO APPEARS THAT ALL THE MODELS ARE
TRENDING FARTHER WEST WITH HEART OF COLDEST 8H TEMPS (-20C OR
COLDER) MOVING THROUGH THE NRN AND CENTRAL PLAINS INSTEAD OF THE
UPPER GREAT LAKES REGION. THE COMBINATION OF THE WEAKENING SFC LOW
AND WEAKER OVERWATER INSTABILITY WITH FCST 8H TEMPS OF -15 TO 18C
WILL LIKELY RESULT IN LESS LAKE EFFECT SNOW AND BLOWING SNOW BEHIND
THE SYSTEM THAN ORIGINALLY THOUGHT. HOWEVER...THERE WILL STILL BE A
GOOD CHANCE FOR ADVISORY CRITERIA LAKE EFFECT SNOWFALL OVER THE WRN
CWA THU AFTERNOON INTO FRI MORNING...AND OVER THE NCNTRL COUNTIES
LATE THU NIGHT INTO FRIDAY WHEN THESE COLDER TEMPS SPREAD FROM WEST
TO EAST ACROSS LAKE SUPERIOR IN THE WAKE OF THE FRONTAL PASSAGE IN A
CYCLONIC CONVERGENT NRLY FLOW. A PERIOD OF GUSTY NRLY WINDS TO
PERHAPS TO 30 MPH IS STILL POSSIBLE...ESPECIALLY ALONG LAKE
SUPERIOR...WHICH COULD ALSO CAUSE CONSIDERABLE BLOWING AND DRIFTING
OF SNOW ALONG WITH LOWERED VSBY. LEANING TOWARD ISSUING A SPS TO
HIGHLIGHT THE POTENTIAL FOR MODERATE LES AND BLOWING SNOW FOR WEST
AND NCNTRL COUNTIES THU AFTERNOON INTO FRI MORNING.
BY THE TIME THE COLDEST 8H TEMPS REACH INTO THE ERN HALF OF THE LAKE
LATE FRI MORNING...THE NRLY FLOW WILL BE WEAKENING A BIT WITH LARGE
SCALE FLOW BECOMING INCREASINGLY ANTICYCLONIC FROM THE NORTH AND
WEST AS SFC RDG BEGINS TO BUILD IN FROM THE NRN PLAINS AND ONTARIO.
LAKE EFFECT SNOW WILL TAPER OFF QUICKLY FM THE WEST FRI AFTERNOON
INTO FRI EVENING AS SFC RDG BUILDS ACROSS THE AREA AND 8H TEMPS WARM
TO NEAR -12C. AN INCH OR TWO OF ADDITIONAL LES IS POSSIBLE OVER THE
ERN COUNTIES FRI NIGHT IN A LAND BREEZE ENHANCED CONVERGENT NW WIND
FLOW. PARTIAL CLEARING OVER THE WRN INTERIOR ALONG WITH LIGHT WINDS
UNDER SFC RDG SHOULD ALLOW TEMPS TO DIP INTO AT LEAST THE SINGLE
DIGITS BLO ZERO FRI EVENING. SOME INCREASE IN CLOUDS AND MAYBE EVEN
A DUSTING OF LIGHT SNOW IS POSSIBLE OVER THE WEST LATE FRI NIGHT AS
THE NEXT CLIPPER SYSTEM DIVES THROUGH THE NRN PLAINS.
SATURDAY AND SUNDAY...MODELS SHOW THE NEXT CLIPPER SYSTEM DIVING DOWN
THROUGH NRN MANITOBA AND NRN ONTARIO LATE SATURDAY AND SAT NIGHT.
IT/S QUESTIONABLE WHETHER INCREASING WEST WINDS AHEAD OF THIS SYSTEM
WILL GENERATE ANY LIGHT LES OVER THE KEWEENAW ON SAT AS 8H TEMPS
NEAR -12C MAY NOT BE COLD ENOUGH FOR SUFFICIENT OVER WATER
INSTABILITY. AS CLIPPER AND ASSOC SFC LOW MOVE NEAR JAMES BAY BY 12Z
SUN...MODELS SHOW LIGHT SYSTEM SNOW SPREADING INTO NRN AND ERN
SECTIONS OF THE CWA LATE SUN NIGHT ALONG AND AHEAD OF ADVANCING COLD
FRONT. A PERIOD OF LES IS LIKELY OVER THE NCNTRL AND ERN CWA ON
SUNDAY WITH CAA NW FLOW IN WAKE OF COLD FRONT.
SUNDAY NIGHT INTO TUESDAY...ECMWF AND GFS IN DECENT AGREEMENT
SHOWING A SERIES OF CLIPPER SHORTWAVES MOVING THROUGH FOR THE SUN
NIGHT INTO MON NIGHT TIME FRAME. THESE SHORTWAVES WILL BRING CHCS
FOR MORE LIGHT SYSTEM SNOW SUN NIGHT AND MONDAY WHILE USHERING IN A
MUCH COLDER AIRMASS FOR MONDAY NIGHT INTO TUESDAY AS THE ECMWF
INDICATES 8H TEMPS DROPPING TO NEAR -25C BY TUESDAY. EXPECT ANOTHER
ROUND OF LAKE EFFECT SNOW AND BLOWING SNOW MON NIGHT INTO TUESDAY
FOR N-NE LAKE SUPERIOR SNOWBELTS. INCREASINGLY COLDER AIRMASS WILL
RESULT IN FINE SNOWFLAKES BY TUESDAY AS THE DGZ GETS SQUASHED NEAR
THE LAKE SFC. THE FINE SNOWFLAKES WILL BE EFFECTIVE AT LOWERING VSBY
IN BLOWING SNOW. IT APPEARS THAT A SERIES OF CLIPPER SHORTWAVES WILL
CONTINUE TO REINFORCE ARCTIC AIRMASS THROUGH MUCH OF THE WORK WEEK
KEEPING TEMPS WELL BELOW NORMAL FROM TUE THROUGH AT LEAST THU WITH
LIGHT TO MODERATE LAKE EFFECT SNOW CONTINUING FOR THE NORTH WIND LAKE
SUPERIOR SNOWBELTS. &&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1151 PM EST TUE JAN 14 2014
LAKE EFFECT SNOW SHOWERS WILL CONTINUE THROUGH THE MORNING AT ALL
SITES WITH MVFR CONDITIONS AT ALL SITES THROUGH MID MORNING. ONLY
EXCEPTION WILL BRIEFLY BE AT SAW EARLY THIS MORNING AS A STRONGER
LAKE EFFECT SNOW BAND SLOWLY MOVES EAST OF THE AREA AND IN THIS BAND
WILL BE IFR CONDITIONS. AS WINDS BACK TO THE SW...LAKE EFFECT WILL
END AND CONDITIONS WILL GO TO VFR AT ALL SITES IN THE AFTERNOON.
NEXT DISTURBANCE ARRIVES BY EVENING WITH MVFR CONDITIONS AND LIGHT
SNOW BREAKING OUT IN THE EVENING AT ALL SITES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 453 AM EST WED JAN 15 2014
A LOW CENTERED OVER CENTRAL LAKE HURON WILL DEPART THE GREAT LAKES
REGION TODAY...ALLOWING A HIGH PRESSURE RIDGE TO QUICKLY SLIDE OVER
LAKE SUPERIOR. THIS WILL LEAD TO WEAKENING WINDS THIS
MORNING...WHICH WILL THEN QUICKLY BACK TO THE SOUTHWEST AND
INCREASE THIS AFTERNOON AND EVENING AHEAD OF ANOTHER CLIPPER
SYSTEM. THINK THE SUSTAINED WINDS WILL BE IN THE 25-30KT RANGE OVER
THE WESTERN LAKE THIS EVENING WITH FREQUENT ENOUGH GUSTS TO 35
KNOTS TO SUPPORT ISSUING A GALE WARNING FOR ABOUT A 6-9HR PERIOD.
SINCE THE LOW WILL BE WEAKENING AS IT MOVES TOWARDS LAKE
SUPERIOR...AM A LITTLE UNCERTAIN ON HOW STRONG THE WINDS WILL BE
OVER THE EASTERN LAKE...BUT SHOULD SUPPORT AT LEAST SOME GALE FORCE
GUSTS TO 35KTS. THIS LOW WILL MOVE OVER WESTERN LAKE SUEPRIOR
OVERNIGHT AND DECREASE WINDS ACROSS THE LAKE. AS IT MOVES ACROSS
UPPER MICHIGAN ON THURSDAY AND SLOWLY WEAKENS...WINDS WILL TURN TO
THE NORTH FROM WEST TO EAST THURSDAY AFTERNOON THROUGH THURSDAY
NIGHT. THERE IS THE POTENTIAL FOR SOME GALES TO 35KTS ON THE BACK
SIDE OF THIS LOW...ESPECIALLY OVER WESTERN LAKE SUPERIOR WHEN THE
LOW IS STILL A LITTLE STRONGER. THIS LOW WILL DEPART THE AREA ON
FRIDAY AND ALLOW A WEAK HIGH PRESSURE RIDGE TO SLIDE ACROSS THE
LAKE FRIDAY AFTERNOON AND FRIDAY NIGHT. A COUPLE OTHER CLIPPER
SYSTEMS WILL BE NEAR THE GREAT LAKES REGION THIS WEEKEND. THE
STRONGEST ONE WILL MOVE THROUGH NORTHEAST ONTARIO ON SATURDAY NIGHT
AND DRAG A COLD FRONT ACROSS LAKE SUPERIOR LATE SATURDAY NIGHT AND
SUNDAY MORNING...WHICH WILL BRING ANOTHER POSSIBILITY OF NORTHWEST
GALES TO 35KTS.
HEAVY FREEZING SPRAY SHOULD DIMINISH THIS MORNING BUT THEN COME
BACK LATE THIS AFTERNOON AND EVENING. DID ISSUES A HEAVY FREEZING
SPRAY WARNING FOR THE WEST HALF OF THE LAKE TO ACCOUNT FOR THAT.
WHEN THE WINDS TURN NORTHERLY THURSDAY NIGHT INTO FRIDAY...SHOULD
SEE ANOTHER PERIOD OF HEAVY FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST THIS MORNING FOR
MIZ006.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
LSZ248>251-265>267.
GALE WARNING FROM 10 PM THIS EVENING TO 4 AM EST THURSDAY FOR
LSZ266-267.
HEAVY FREEZING SPRAY WARNING FROM 5 PM EST /4 PM CST/ THIS
AFTERNOON TO 1 AM EST /MIDNIGHT CST/ THURSDAY FOR LSZ162-
263-264.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR
LSZ244-245-263-264.
GALE WARNING FROM 7 PM THIS EVENING TO 1 AM EST THURSDAY FOR
LSZ263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...VOSS
AVIATION...07
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
540 AM EST WED JAN 15 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 453 AM EST WED JAN 15 2014
THE CLIPPER SYSTEM THAT BROUGHT THE SNOW TO THE SOUTH CENTRAL CWA
YESTERDAY CONTINUES TO PULL OUT OF THE REGION EARLY THIS MORNING
AND IS CURRENTLY OVER NORTHERN LAKE HURON AT 1002MB. MEANWHILE...A
HIGH PRESSURE RIDGE OF 1024MB OVER THE EASTERN DAKOTAS IS BEGINNING
TO SHIFT INTO WESTERN MINNESOTA. THE TIGHT GRADIENT BETWEEN THESE
TWO FEATURES AND RAP ANALYZED 850MB TEMPS OF -16C HAS LED TO LAKE
EFFECT SNOW OVER MOST OF THE NORTHERLY WIND FAVORED AREAS NEAR LAKE
SUPERIOR. THE STRONGEST LAKE EFFECT HAS BEEN OVER FAR EASTERN
MARQUETTE COUNTY AND WESTERN ALGER COUNTY...WHERE THERE HAS BEEN
INCREASED CONVERGENCE FROM THE DEPARTING SYSTEM AND GRADUALLY
BACKING WINDS. WITH THE STRONGER WINDS OF 27KTS AT STDM4...THESE
BANDS HAVE BEEN EASILY REACHING SOUTHERN DELTA/SCHOOLCRAFT COUNTIES.
WITH THE QUICK DEPARTURE OF THE LOW AND THE ARRIVAL OF THE
RIDGE...SHOULD SEE A VERY QUICK BACKING TREND TO THE WINDS OVER THE
WESTERN LAKE TODAY AND ALLOW THE REMAINING LAKE EFFECT TO PUSH
NORTHEAST ACROSS THE KEWEENAW PENINSULA AND OUT OVER THE OPEN LAKE
BY 21Z. OVER THE EAST HALF...THE BACKING WINDS WILL TAKE A LITTLE
BIT LONGER TO ARRIVE...BUT HAVE ALREADY STARTED TO SEE THEM BACK TO
THE NORTHWEST AT STANNARD ROCK AND GRANITE ISLAND. THUS...EXPECT THE
FOCUSED LAKE EFFECT OVER EASTERN MARQUETTE AND WESTERN ALGER COUNTY
TO CONTINUE TO AROUND OR SHORTLY BEFORE DAYBREAK AND THEN THE
INFLUENCE OF THE BACKING WINDS WILL TAKE HOLD AND STEADILY SHIFT THE
BANDS EASTWARD ACROSS ALGER COUNTY THROUGH THE DAY. 925MB WINDS LOOK
TO BE WEST OR WEST-SOUTHWEST AROUND 21Z AND SHOULD SEE THE LAST OF
THE SNOW SHOWERS MOVING AWAY FROM GRAND MARAIS AT OR SHORTLY AFTER
THAT TIME. WITH GUSTS TO 25-30KTS RIGHT ALONG THE LAKE SUPERIOR
SHORELINE...OPTED TO EXTEND THE ADVISORY FOR ANOTHER 3HRS (UNTIL
15Z) SINCE CONDITIONS ALONG M-28 WILL LIKELY BE POOR THIS MORNING.
FELT 15Z WAS A REASONABLE ENDING TIME SINCE THE WINDS WILL BE
DIMINISHING AND THE BANDS STARTING TO PUSH EAST. WILL ALSO ISSUE AN
SPS FOR EASTERN MARQUETTE COUNTY SHORTLY TO COVER M-28 EAST OF
HARVEY WITH THE BLOWING SNOW AND LAKE EFFECT.
THE NEXT CLIPPER SYSTEM TO AFFECT THE AREA IS CURRENTLY DROPPING
SOUTHEAST THROUGH SASKATCHEWAN AT THIS TIME AND WILL QUICKLY MOVE
SOUTHEAST THROUGH CANADA TODAY. THE INITIAL PUSH OF THE SHORTWAVE
WILL ARRIVE FROM WEST TO EAST THIS EVENING AND INTO THE OVERNIGHT
HOURS AND BRING THE FIRST WAVE OF SNOW WITH THIS SYSTEM. MODELS
CONTINUE TO VARY ON THE HANDLING OF THE LOW FOR THURSDAY...BUT THE
GENERAL IDEA OF THE LOW WILL BE LAGGING BEHIND AND MOVING OVER
WESTERN LAKE SUPERIOR AROUND 12Z THURSDAY SEEMS REASONABLE. THE
FIRST PUSH OF SNOW WILL BE ASSOCIATED WITH THE MAIN SHORTWAVE
ENERGY MOVING OVER THE WESTERN HALF OF THE CWA DURING THE EVENING
AND BECOMING A LITTLE MORE DIFFUSE AS IT MOVES OVER THE EASTERN
CWA. IN ADDITION TO THE SHORTWAVE...THERE IS A NARROW CORRIDOR OF
DEEP MOISTURE...850-500MB Q-VECTOR CONVERGENCE AND WARM AIR
ADVECTION...AND ISENTROPIC ASCENT ON THE 275-295K SURFACES. THIS
WOULD SUPPORT A NICE BAND OF LIGHT TO BRIEFLY MODERATE SNOW MOVING
ACROSS THE WESTERN CWA...BUT DUE TO THE NARROW AND QUICK MOVEMENT OF
THE FEATURES IT SHOULD ONLY LEAD TO A 3-4HR PERIOD OF SNOW AS IT
MOVES THROUGH. IN ADDITION...THE LATEST FORCING IN THE MODELS SEEMS
TO BE A LITTLE MORE SOUTHWEST AND FOCUSED NEAR GOGEBIC/IRON
COUNTIES BEFORE WEAKENING. RATIOS ARE TRICKY AS THE CLOUD LAYER IS
INITIALLY IN THE DGZ...BUT THEN MOVES TO THE BOTTOM OR BELOW AS THE
WARM AIR ADVECTION TAKES HOLD. IN ADDITION...THE STRONG WINDS IN
AND BELOW THE CLOUD LAYER MAY PRODUCE SOME FRACTURING AND LIMITING
RATIOS SOMEWHAT. OPTED TO GO HIGHER INITIALLY (16-18 TO 1) AND THEN
DROP TOWARDS 13 TO 1 AS THE WARM AIR SURGES IN AND THE SNOW
DIMINISHES.
OVER THE EAST...THAT AREA OF SNOW WILL SHOULD ARRIVE AROUND
MIDNIGHT...BUT THINK IT WILL BE ON A LITTLE BIT OF A DIMINISHING
TREND SINCE THE MODELS ARE SHOWING THE SHORTWAVE AND WAA BECOMING
WEAKER. ONE ITEM THAT COULD COUNTERACT SOME OF THIS WEAKENING IDEA
IS LAKE ENHANCEMENT OFF LAKE MICHIGAN WITH THE SOUTHWESTERLY WINDS.
AT LEAST INITIALLY...THERE IS SOME QUESTION IN HOW MUCH LOW LEVEL
MOISTURE WILL BE PRESENT DURING THE FIRST PART OF THE EVENING DUE TO
THE HIGH PRESSURE RIDGE. WOULD THINK THERE WOULD BE AT LEAST SOME
CLOUDS OR LIGHT SNOW SHOWERS SOUTHEAST OF A LINE FROM KISQ-KERY
BEFORE THE BETTER MOISTURE ARRIVES AND WINDS TURN A LITTLE MORE
SOUTH-SOUTHWESTERLY AND FOCUS THE LAKE ENHANCEMENT MORE INTO THE CWA
AROUND MIDNIGHT AND THROUGH MUCH OF THE REST OF THE NIGHT. 875MB
TEMPS STAY AROUND -14C FOR MUCH OF THE NIGHT...SO THERE IS DECENT
DELTA-T VALUES. DO HAVE A COUPLE CONCERNS ON HIGHER AMOUNTS AND IT
LARGELY HAS TO DO WITH THE SNOW RATIOS. FIRST...MUCH OF THE CLOUD IS
AT THE LOW END OF THE DGZ. SECOND...WITH THE STRONG WINDS IN THE
CLOUD LAYER...WOULD EXPECT THE DENDRITES THAT DO DEVELOP TO FRACTURE
ON THEIR WAY DOWN. BOTH OF THESE SHOULD LEAD TO RATIOS IN THE UPPER
TEENS.
12HR QPF FOR TONIGHT FROM THE MODELS IS GENERALLY BETWEEN 0.07-0.15
OF AN INCH FOR MUCH OF THE CWA AND USED A GENERAL MIDDLE GROUND FOR
THE FORECAST. THIS LEADS TO SNOWFALL AMOUNTS BETWEEN 1-2 INCHES
TONIGHT. DO HAVE SLIGHTLY HIGHER AMOUNTS OVER THE FAR EAST WHERE
THE LAKE ENHANCEMENT SHOULD PUSH AMOUNTS BETWEEN 2-3 INCHES. IN
ADDITION TO THE SNOW...THERE WILL BE GUSTY SOUTHWEST WINDS
(20-30MPH) THAT PRODUCE SOME BLOWING AND DRIFTING OF THE SNOW AND
MAY HELP REDUCE VISIBILITIES BELOW A MILE AS THE INITIAL SNOW MOVES
THROUGH. ALTHOUGH THE SNOW IS SUB ADVISORY...THE WIND PUSHES THE
CONCERN UP SOME FOR THAT SHORT PERIOD WHEN THE SNOW OCCURS. BUT
SINCE IT WILL ONLY BE A FEW HOUR PERIOD OF SNOW...DO THINK THAT IS
ENOUGH TO WARRENT AN ADVISORY. IN ADDITION...WITH IT OCCURRING
DURING THE LATTER PART OF THE EVENING AND THROUGH THE OVERNIGHT
HOURS...THE SOCIETAL IMPACT WILL BE LIMITED AND THUS WILL ISSUE A
AN SPS LATER THIS MORNING WITH INFO FOR THURSDAY INTO FRIDAY TOO.
ONCE THAT INITIAL WAVE OF PRECIP MOVES THROUGH...LOOKS LIKE THERE
WILL BE A MID LEVEL DRY SLOT THAT DIMINISHES OR ENDS THE SNOW FOR A
PERIOD BEFORE THE NEXT SHORTWAVE AND DEEPER MOISTURE WITH THE LOW
ARRIVES AFTER 09Z OVER THE WEST. THUS...HAVE CUT POPS BACK TO JUST
CHANCE WORDING OVER THE WEST AND MINIMAL ADDITIONAL ACCUMULATION.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 540 AM EST WED JAN 15 2014
LARGE SCALE PATTERN THROUGH THE EXTENDED CONSISTS OF A MEAN RIDGE
OVER WRN NORTH AMERICA WHILE A TROUGH DOMINATES DOMINATES MUCH OF
ERN NORTH AMERICA...INCLUDING THE GREAT LAKES. STRONGEST CLIPPER
SHORTWAVE MOVING THROUGH THE TROUGH CROSSES THE UPPER GREAT LAKES
WEDNESDAY NIGHT THROUGH EARLY FRIDAY. DAYTIME HIGHS WILL END UP
SLIGHTLY BLO NORMAL FOR MUCH OF THE TIME. ONE OF THE WARMEST DAYS OF
THE EXTENDED WILL BE ON THURSDAY AHEAD OF STRONGER COLD FRONT ASSOC
WITH INITIAL CLIPPER SHORTWAVE. BRIEF WARMING MAY OCCUR NEXT MONDAY
ONLY TO BE FOLLOWED BY ANOTHER CLIPPER SHORTWAVE AND BLAST OF ARCTIC
AIR ON TUESDAY.
THURSDAY AND FRIDAY...SYSTEM SNOW WILL GENERALLY BE TAPERING OFF THU
MORNING AS THE BEST WAA/ISENTROPIC LIFT BEGINS TO SHIFT EAST. ALSO
LAKE ENHANCED SNOW OVER THE ERN COUNTIES SHOULD BE TAPERING OFF BY
LATE THU MORNING AS OVERWATER INSTABILITY WEAKENS WITH WARMER TEMPS
-7C TEMPS MOVING OVER NRN LAKE MI. MODELS DIFFER ON EVOLUTION/TRACK
OF SFC LOW MOVING THROUGH THE CWA THU INTO THU NIGHT. THE GFS AND
ECMWF ARE DEEPER INITIALLY WITH THE SFC LOW THAN EITHER THE
NAM/GEM-NH OR UKMET. THE GFS/NAM AND UKMET TRACK THE SFC LOW ACROSS
UPPER MI ON THU WHILE THE ECMWF AND GEM-NH TAKE THE LOW JUST SOUTH
OF THE WI BDR. ALL MODELS NOW APPEAR TO SHOW THE LOW FILLING AS IT
TRACKS ACROSS THE UPPER GREAT LAKES ON THU AND THEN EAST OF THE
REGION FRI INTO FRI NIGHT. IT ALSO APPEARS THAT ALL THE MODELS ARE
TRENDING FARTHER WEST WITH HEART OF COLDEST 8H TEMPS (-20C OR
COLDER) MOVING THROUGH THE NRN AND CENTRAL PLAINS INSTEAD OF THE
UPPER GREAT LAKES REGION. THE COMBINATION OF THE WEAKENING SFC LOW
AND WEAKER OVERWATER INSTABILITY WITH FCST 8H TEMPS OF -15 TO 18C
WILL LIKELY RESULT IN LESS LAKE EFFECT SNOW AND BLOWING SNOW BEHIND
THE SYSTEM THAN ORIGINALLY THOUGHT. HOWEVER...THERE WILL STILL BE A
GOOD CHANCE FOR ADVISORY CRITERIA LAKE EFFECT SNOWFALL OVER THE WRN
CWA THU AFTERNOON INTO FRI MORNING...AND OVER THE NCNTRL COUNTIES
LATE THU NIGHT INTO FRIDAY WHEN THESE COLDER TEMPS SPREAD FROM WEST
TO EAST ACROSS LAKE SUPERIOR IN THE WAKE OF THE FRONTAL PASSAGE IN A
CYCLONIC CONVERGENT NRLY FLOW. A PERIOD OF GUSTY NRLY WINDS TO
PERHAPS TO 30 MPH IS STILL POSSIBLE...ESPECIALLY ALONG LAKE
SUPERIOR...WHICH COULD ALSO CAUSE CONSIDERABLE BLOWING AND DRIFTING
OF SNOW ALONG WITH LOWERED VSBY. LEANING TOWARD ISSUING A SPS TO
HIGHLIGHT THE POTENTIAL FOR MODERATE LES AND BLOWING SNOW FOR WEST
AND NCNTRL COUNTIES THU AFTERNOON INTO FRI MORNING.
BY THE TIME THE COLDEST 8H TEMPS REACH INTO THE ERN HALF OF THE LAKE
LATE FRI MORNING...THE NRLY FLOW WILL BE WEAKENING A BIT WITH LARGE
SCALE FLOW BECOMING INCREASINGLY ANTICYCLONIC FROM THE NORTH AND
WEST AS SFC RDG BEGINS TO BUILD IN FROM THE NRN PLAINS AND ONTARIO.
LAKE EFFECT SNOW WILL TAPER OFF QUICKLY FM THE WEST FRI AFTERNOON
INTO FRI EVENING AS SFC RDG BUILDS ACROSS THE AREA AND 8H TEMPS WARM
TO NEAR -12C. AN INCH OR TWO OF ADDITIONAL LES IS POSSIBLE OVER THE
ERN COUNTIES FRI NIGHT IN A LAND BREEZE ENHANCED CONVERGENT NW WIND
FLOW. PARTIAL CLEARING OVER THE WRN INTERIOR ALONG WITH LIGHT WINDS
UNDER SFC RDG SHOULD ALLOW TEMPS TO DIP INTO AT LEAST THE SINGLE
DIGITS BLO ZERO FRI EVENING. SOME INCREASE IN CLOUDS AND MAYBE EVEN
A DUSTING OF LIGHT SNOW IS POSSIBLE OVER THE WEST LATE FRI NIGHT AS
THE NEXT CLIPPER SYSTEM DIVES THROUGH THE NRN PLAINS.
SATURDAY AND SUNDAY...MODELS SHOW THE NEXT CLIPPER SYSTEM DIVING DOWN
THROUGH NRN MANITOBA AND NRN ONTARIO LATE SATURDAY AND SAT NIGHT.
IT/S QUESTIONABLE WHETHER INCREASING WEST WINDS AHEAD OF THIS SYSTEM
WILL GENERATE ANY LIGHT LES OVER THE KEWEENAW ON SAT AS 8H TEMPS
NEAR -12C MAY NOT BE COLD ENOUGH FOR SUFFICIENT OVER WATER
INSTABILITY. AS CLIPPER AND ASSOC SFC LOW MOVE NEAR JAMES BAY BY 12Z
SUN...MODELS SHOW LIGHT SYSTEM SNOW SPREADING INTO NRN AND ERN
SECTIONS OF THE CWA LATE SUN NIGHT ALONG AND AHEAD OF ADVANCING COLD
FRONT. A PERIOD OF LES IS LIKELY OVER THE NCNTRL AND ERN CWA ON
SUNDAY WITH CAA NW FLOW IN WAKE OF COLD FRONT.
SUNDAY NIGHT INTO TUESDAY...ECMWF AND GFS IN DECENT AGREEMENT
SHOWING A SERIES OF CLIPPER SHORTWAVES MOVING THROUGH FOR THE SUN
NIGHT INTO MON NIGHT TIME FRAME. THESE SHORTWAVES WILL BRING CHCS
FOR MORE LIGHT SYSTEM SNOW SUN NIGHT AND MONDAY WHILE USHERING IN A
MUCH COLDER AIRMASS FOR MONDAY NIGHT INTO TUESDAY AS THE ECMWF
INDICATES 8H TEMPS DROPPING TO NEAR -25C BY TUESDAY. EXPECT ANOTHER
ROUND OF LAKE EFFECT SNOW AND BLOWING SNOW MON NIGHT INTO TUESDAY
FOR N-NE LAKE SUPERIOR SNOWBELTS. INCREASINGLY COLDER AIRMASS WILL
RESULT IN FINE SNOWFLAKES BY TUESDAY AS THE DGZ GETS SQUASHED NEAR
THE LAKE SFC. THE FINE SNOWFLAKES WILL BE EFFECTIVE AT LOWERING VSBY
IN BLOWING SNOW. BELOW NORMAL TEMPS. IT APPEARS THAT A SERIES OF
CLIPPER SHORTWAVES WILL CONTINUE TO REINFORCE ARCTIC AIRMASS THROUGH
MUCH OF THE WORK WEEK KEEPING TEMPS WELL BELOW NORMAL FROM TUE
THROUGH AT LEAST THU WITH LIGHT TO MODERATE LAKE EFFECT SNOW
CONTINUING FOR THE NORTH WIND LAKE SUPERIOR SNOWBELTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1151 PM EST TUE JAN 14 2014
LAKE EFFECT SNOW SHOWERS WILL CONTINUE THROUGH THE MORNING AT ALL
SITES WITH MVFR CONDITIONS AT ALL SITES THROUGH MID MORNING. ONLY
EXCEPTION WILL BRIEFLY BE AT SAW EARLY THIS MORNING AS A STRONGER
LAKE EFFECT SNOW BAND SLOWLY MOVES EAST OF THE AREA AND IN THIS BAND
WILL BE IFR CONDITIONS. AS WINDS BACK TO THE SW...LAKE EFFECT WILL
END AND CONDITIONS WILL GO TO VFR AT ALL SITES IN THE AFTERNOON.
NEXT DISTURBANCE ARRIVES BY EVENING WITH MVFR CONDITIONS AND LIGHT
SNOW BREAKING OUT IN THE EVENING AT ALL SITES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 453 AM EST WED JAN 15 2014
A LOW CENTERED OVER CENTRAL LAKE HURON WILL DEPART THE GREAT LAKES
REGION TODAY...ALLOWING A HIGH PRESSURE RIDGE TO QUICKLY SLIDE OVER
LAKE SUPERIOR. THIS WILL LEAD TO WEAKENING WINDS THIS
MORNING...WHICH WILL THEN QUICKLY BACK TO THE SOUTHWEST AND
INCREASE THIS AFTERNOON AND EVENING AHEAD OF ANOTHER CLIPPER
SYSTEM. THINK THE SUSTAINED WINDS WILL BE IN THE 25-30KT RANGE OVER
THE WESTERN LAKE THIS EVENING WITH FREQUENT ENOUGH GUSTS TO 35
KNOTS TO SUPPORT ISSUING A GALE WARNING FOR ABOUT A 6-9HR PERIOD.
SINCE THE LOW WILL BE WEAKENING AS IT MOVES TOWARDS LAKE
SUPERIOR...AM A LITTLE UNCERTAIN ON HOW STRONG THE WINDS WILL BE
OVER THE EASTERN LAKE...BUT SHOULD SUPPORT AT LEAST SOME GALE FORCE
GUSTS TO 35KTS. THIS LOW WILL MOVE OVER WESTERN LAKE SUEPRIOR
OVERNIGHT AND DECREASE WINDS ACROSS THE LAKE. AS IT MOVES ACROSS
UPPER MICHIGAN ON THURSDAY AND SLOWLY WEAKENS...WINDS WILL TURN TO
THE NORTH FROM WEST TO EAST THURSDAY AFTERNOON THROUGH THURSDAY
NIGHT. THERE IS THE POTENTIAL FOR SOME GALES TO 35KTS ON THE BACK
SIDE OF THIS LOW...ESPECIALLY OVER WESTERN LAKE SUPERIOR WHEN THE
LOW IS STILL A LITTLE STRONGER. THIS LOW WILL DEPART THE AREA ON
FRIDAY AND ALLOW A WEAK HIGH PRESSURE RIDGE TO SLIDE ACROSS THE
LAKE FRIDAY AFTERNOON AND FRIDAY NIGHT. A COUPLE OTHER CLIPPER
SYSTEMS WILL BE NEAR THE GREAT LAKES REGION THIS WEEKEND. THE
STRONGEST ONE WILL MOVE THROUGH NORTHEAST ONTARIO ON SATURDAY NIGHT
AND DRAG A COLD FRONT ACROSS LAKE SUPERIOR LATE SATURDAY NIGHT AND
SUNDAY MORNING...WHICH WILL BRING ANOTHER POSSIBILITY OF NORTHWEST
GALES TO 35KTS.
HEAVY FREEZING SPRAY SHOULD DIMINISH THIS MORNING BUT THEN COME
BACK LATE THIS AFTERNOON AND EVENING. DID ISSUES A HEAVY FREEZING
SPRAY WARNING FOR THE WEST HALF OF THE LAKE TO ACCOUNT FOR THAT.
WHEN THE WINDS TURN NORTHERLY THURSDAY NIGHT INTO FRIDAY...SHOULD
SEE ANOTHER PERIOD OF HEAVY FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST THIS MORNING FOR
MIZ006.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
LSZ248>251-265>267.
GALE WARNING FROM 10 PM THIS EVENING TO 4 AM EST THURSDAY FOR
LSZ266-267.
HEAVY FREEZING SPRAY WARNING FROM 5 PM EST /4 PM CST/ THIS
AFTERNOON TO 1 AM EST /MIDNIGHT CST/ THURSDAY FOR LSZ162-
263-264.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR
LSZ244-245-263-264.
GALE WARNING FROM 7 PM THIS EVENING TO 1 AM EST THURSDAY FOR
LSZ263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...VOSS
AVIATION...07
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
454 AM EST WED JAN 15 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 453 AM EST WED JAN 15 2014
THE CLIPPER SYSTEM THAT BROUGHT THE SNOW TO THE SOUTH CENTRAL CWA
YESTERDAY CONTINUES TO PULL OUT OF THE REGION EARLY THIS MORNING
AND IS CURRENTLY OVER NORTHERN LAKE HURON AT 1002MB. MEANWHILE...A
HIGH PRESSURE RIDGE OF 1024MB OVER THE EASTERN DAKOTAS IS BEGINNING
TO SHIFT INTO WESTERN MINNESOTA. THE TIGHT GRADIENT BETWEEN THESE
TWO FEATURES AND RAP ANALYZED 850MB TEMPS OF -16C HAS LED TO LAKE
EFFECT SNOW OVER MOST OF THE NORTHERLY WIND FAVORED AREAS NEAR LAKE
SUPERIOR. THE STRONGEST LAKE EFFECT HAS BEEN OVER FAR EASTERN
MARQUETTE COUNTY AND WESTERN ALGER COUNTY...WHERE THERE HAS BEEN
INCREASED CONVERGENCE FROM THE DEPARTING SYSTEM AND GRADUALLY
BACKING WINDS. WITH THE STRONGER WINDS OF 27KTS AT STDM4...THESE
BANDS HAVE BEEN EASILY REACHING SOUTHERN DELTA/SCHOOLCRAFT COUNTIES.
WITH THE QUICK DEPARTURE OF THE LOW AND THE ARRIVAL OF THE
RIDGE...SHOULD SEE A VERY QUICK BACKING TREND TO THE WINDS OVER THE
WESTERN LAKE TODAY AND ALLOW THE REMAINING LAKE EFFECT TO PUSH
NORTHEAST ACROSS THE KEWEENAW PENINSULA AND OUT OVER THE OPEN LAKE
BY 21Z. OVER THE EAST HALF...THE BACKING WINDS WILL TAKE A LITTLE
BIT LONGER TO ARRIVE...BUT HAVE ALREADY STARTED TO SEE THEM BACK TO
THE NORTHWEST AT STANNARD ROCK AND GRANITE ISLAND. THUS...EXPECT THE
FOCUSED LAKE EFFECT OVER EASTERN MARQUETTE AND WESTERN ALGER COUNTY
TO CONTINUE TO AROUND OR SHORTLY BEFORE DAYBREAK AND THEN THE
INFLUENCE OF THE BACKING WINDS WILL TAKE HOLD AND STEADILY SHIFT THE
BANDS EASTWARD ACROSS ALGER COUNTY THROUGH THE DAY. 925MB WINDS LOOK
TO BE WEST OR WEST-SOUTHWEST AROUND 21Z AND SHOULD SEE THE LAST OF
THE SNOW SHOWERS MOVING AWAY FROM GRAND MARAIS AT OR SHORTLY AFTER
THAT TIME. WITH GUSTS TO 25-30KTS RIGHT ALONG THE LAKE SUPERIOR
SHORELINE...OPTED TO EXTEND THE ADVISORY FOR ANOTHER 3HRS (UNTIL
15Z) SINCE CONDITIONS ALONG M-28 WILL LIKELY BE POOR THIS MORNING.
FELT 15Z WAS A REASONABLE ENDING TIME SINCE THE WINDS WILL BE
DIMINISHING AND THE BANDS STARTING TO PUSH EAST. WILL ALSO ISSUE AN
SPS FOR EASTERN MARQUETTE COUNTY SHORTLY TO COVER M-28 EAST OF
HARVEY WITH THE BLOWING SNOW AND LAKE EFFECT.
THE NEXT CLIPPER SYSTEM TO AFFECT THE AREA IS CURRENTLY DROPPING
SOUTHEAST THROUGH SASKATCHEWAN AT THIS TIME AND WILL QUICKLY MOVE
SOUTHEAST THROUGH CANADA TODAY. THE INITIAL PUSH OF THE SHORTWAVE
WILL ARRIVE FROM WEST TO EAST THIS EVENING AND INTO THE OVERNIGHT
HOURS AND BRING THE FIRST WAVE OF SNOW WITH THIS SYSTEM. MODELS
CONTINUE TO VARY ON THE HANDLING OF THE LOW FOR THURSDAY...BUT THE
GENERAL IDEA OF THE LOW WILL BE LAGGING BEHIND AND MOVING OVER
WESTERN LAKE SUPERIOR AROUND 12Z THURSDAY SEEMS REASONABLE. THE
FIRST PUSH OF SNOW WILL BE ASSOCIATED WITH THE MAIN SHORTWAVE
ENERGY MOVING OVER THE WESTERN HALF OF THE CWA DURING THE EVENING
AND BECOMING A LITTLE MORE DIFFUSE AS IT MOVES OVER THE EASTERN
CWA. IN ADDITION TO THE SHORTWAVE...THERE IS A NARROW CORRIDOR OF
DEEP MOISTURE...850-500MB Q-VECTOR CONVERGENCE AND WARM AIR
ADVECTION...AND ISENTROPIC ASCENT ON THE 275-295K SURFACES. THIS
WOULD SUPPORT A NICE BAND OF LIGHT TO BRIEFLY MODERATE SNOW MOVING
ACROSS THE WESTERN CWA...BUT DUE TO THE NARROW AND QUICK MOVEMENT OF
THE FEATURES IT SHOULD ONLY LEAD TO A 3-4HR PERIOD OF SNOW AS IT
MOVES THROUGH. IN ADDITION...THE LATEST FORCING IN THE MODELS SEEMS
TO BE A LITTLE MORE SOUTHWEST AND FOCUSED NEAR GOGEBIC/IRON
COUNTIES BEFORE WEAKENING. RATIOS ARE TRICKY AS THE CLOUD LAYER IS
INITIALLY IN THE DGZ...BUT THEN MOVES TO THE BOTTOM OR BELOW AS THE
WARM AIR ADVECTION TAKES HOLD. IN ADDITION...THE STRONG WINDS IN
AND BELOW THE CLOUD LAYER MAY PRODUCE SOME FRACTURING AND LIMITING
RATIOS SOMEWHAT. OPTED TO GO HIGHER INITIALLY (16-18 TO 1) AND THEN
DROP TOWARDS 13 TO 1 AS THE WARM AIR SURGES IN AND THE SNOW
DIMINISHES.
OVER THE EAST...THAT AREA OF SNOW WILL SHOULD ARRIVE AROUND
MIDNIGHT...BUT THINK IT WILL BE ON A LITTLE BIT OF A DIMINISHING
TREND SINCE THE MODELS ARE SHOWING THE SHORTWAVE AND WAA BECOMING
WEAKER. ONE ITEM THAT COULD COUNTERACT SOME OF THIS WEAKENING IDEA
IS LAKE ENHANCEMENT OFF LAKE MICHIGAN WITH THE SOUTHWESTERLY WINDS.
AT LEAST INITIALLY...THERE IS SOME QUESTION IN HOW MUCH LOW LEVEL
MOISTURE WILL BE PRESENT DURING THE FIRST PART OF THE EVENING DUE TO
THE HIGH PRESSURE RIDGE. WOULD THINK THERE WOULD BE AT LEAST SOME
CLOUDS OR LIGHT SNOW SHOWERS SOUTHEAST OF A LINE FROM KISQ-KERY
BEFORE THE BETTER MOISTURE ARRIVES AND WINDS TURN A LITTLE MORE
SOUTH-SOUTHWESTERLY AND FOCUS THE LAKE ENHANCEMENT MORE INTO THE CWA
AROUND MIDNIGHT AND THROUGH MUCH OF THE REST OF THE NIGHT. 875MB
TEMPS STAY AROUND -14C FOR MUCH OF THE NIGHT...SO THERE IS DECENT
DELTA-T VALUES. DO HAVE A COUPLE CONCERNS ON HIGHER AMOUNTS AND IT
LARGELY HAS TO DO WITH THE SNOW RATIOS. FIRST...MUCH OF THE CLOUD IS
AT THE LOW END OF THE DGZ. SECOND...WITH THE STRONG WINDS IN THE
CLOUD LAYER...WOULD EXPECT THE DENDRITES THAT DO DEVELOP TO FRACTURE
ON THEIR WAY DOWN. BOTH OF THESE SHOULD LEAD TO RATIOS IN THE UPPER
TEENS.
12HR QPF FOR TONIGHT FROM THE MODELS IS GENERALLY BETWEEN 0.07-0.15
OF AN INCH FOR MUCH OF THE CWA AND USED A GENERAL MIDDLE GROUND FOR
THE FORECAST. THIS LEADS TO SNOWFALL AMOUNTS BETWEEN 1-2 INCHES
TONIGHT. DO HAVE SLIGHTLY HIGHER AMOUNTS OVER THE FAR EAST WHERE
THE LAKE ENHANCEMENT SHOULD PUSH AMOUNTS BETWEEN 2-3 INCHES. IN
ADDITION TO THE SNOW...THERE WILL BE GUSTY SOUTHWEST WINDS
(20-30MPH) THAT PRODUCE SOME BLOWING AND DRIFTING OF THE SNOW AND
MAY HELP REDUCE VISIBILITIES BELOW A MILE AS THE INITIAL SNOW MOVES
THROUGH. ALTHOUGH THE SNOW IS SUB ADVISORY...THE WIND PUSHES THE
CONCERN UP SOME FOR THAT SHORT PERIOD WHEN THE SNOW OCCURS. BUT
SINCE IT WILL ONLY BE A FEW HOUR PERIOD OF SNOW...DO THINK THAT IS
ENOUGH TO WARRENT AN ADVISORY. IN ADDITION...WITH IT OCCURRING
DURING THE LATTER PART OF THE EVENING AND THROUGH THE OVERNIGHT
HOURS...THE SOCIETAL IMPACT WILL BE LIMITED AND THUS WILL ISSUE A
AN SPS LATER THIS MORNING WITH INFO FOR THURSDAY INTO FRIDAY TOO.
ONCE THAT INITIAL WAVE OF PRECIP MOVES THROUGH...LOOKS LIKE THERE
WILL BE A MID LEVEL DRY SLOT THAT DIMINISHES OR ENDS THE SNOW FOR A
PERIOD BEFORE THE NEXT SHORTWAVE AND DEEPER MOISTURE WITH THE LOW
ARRIVES AFTER 09Z OVER THE WEST. THUS...HAVE CUT POPS BACK TO JUST
CHANCE WORDING OVER THE WEST AND MINIMAL ADDITIONAL ACCUMULATION.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 446 PM EST TUE JAN 14 2014
RIDGE WEST...TROUGH EAST. THE PATTERN REMAINS THROUGH THROUGH MUCH
OF THE LONG TERM PERIOD.
FOR AN OVERVIEW OF WHAT WILL BE HAPPENING ALOFT...THE 500MB LOW OVER
N MANITOBA AT 00Z THURSDAY WILL SWEEP INTO CENTRAL ONTARIO AND THE W
HALF OF LAKE SUPERIOR BY 12Z THURSDAY. AT THAT POINT THE LOW WILL
SLOW DOWN QUITE A BIT...AND REMAIN ACROSS THE UPPER GREAT LAKES
THROUGH THE DAY THURSDAY...BEFORE THE LINGERING TROUGH SLOWLY EXITS
ACROSS EASTERN ONTARIO AND LAKE HURON FRIDAY AND FRIDAY NIGHT. THIS
WILL KEEP NNW FLOW ALOFT ACROSS LAKE SUPERIOR AND UPPER MI FROM
FRIDAY AFTERNOON THROUGH SUNDAY MONDAY.
AS FOR SPECIFICS...THE SFC LOW NEAR THE S MANITOBA/ONTARIO BORDER
JUST PRIOR TO 06Z THURSDAY SHOULD SHIFT SE INTO S CENTRAL LAKE
SUPERIOR/AND THE W HALF OF UPPER MI BY 18Z. S-SSW WINDS WILL REMAIN
IN THE 10-20KT RANGE WEDNESDAY NIGHT. WARMER AIR WILL BE ABLE TO
SWEEP IN FOR THURSDAY...WITH HIGHS IN THE UPPER 20S...THANKS TO THE
MID AFTERNOON LOW PASSAGE ALLOWING 850MB TEMPS TO RISE INTO THE -5
TO -7F RANGE. EXPECT THE SFC LOW TO EXIT FAR E UPPER MI THURSDAY
NIGHT INTO FRIDAY. GIVEN THE SLOW PROGRESS OF THE LOW...LOOK FOR A
SIGNIFICANT BREAK BETWEEN THE STRONG W-SSW WINDS WEDNESDAY NIGHT AND
COLDER AIR RUSHING IN THE N-NNW WINDS THURSDAY NIGHT INTO FRIDAY.
HIGH FRIDAY SHOULD BE ON THE ORDER OF 15F COOLER OVER W AND CENTRAL
UPPER MI...WHILE ONLY A COULD DEGREES COOLER E.
ALTHOUGH FAR W LAKE SUPERIOR MAY BE PRETTY FROZEN...THERE IS LIKELY
PLENTY OF RELATIVELY WARM OPEN WATER STILL AVAILABLE N OF THE
APOSTLE ISLANDS TO ALLOW THE MAINLY N FLOW OF COLD AIR TO PRODUCE
MODERATE LES FROM LATE THURSDAY AFTERNOON THROUGH THE DAY FRIDAY.
THE FLOW BECOMES MORE W-NW OVER W LAKE SUPERIOR FRIDAY EVENING AS
WAA TAKES HOLD AND 850MB TEMPS THAT WERE ON THE ORDER OF -14 TO -17C
QUICKLY JUMP UP TO AROUND -10C. LES WILL CONTINUE TO PERSIST NEAR
AND E OF MUNISING INTO SATURDAY. THERE IS STILL A QUESTION AS TO HOW
LONG THE FETCH REMAINS FAVORABLE FOR THIS AREA...AS THE 12Z ECMWF IS
GOING WITH A MORE W FLOW NEAR THE SFC...WHICH WOULD KEEP THE BEST
CHANCE OF LES ONLY RIGHT ALONG THE SHORELINE E SATURDAY...IF NOT OFF
SHORE.
A SIZABLE RIDGE EXTENDING UP FROM THE 4-CORNERS REGION THROUGH THE
DAKOTAS AND SOUTH CENTRAL CANADA SUNDAY MORNING WILL BRIEFLY MOVE
ACROSS THE UPPER GREAT LAKES SUNDAY AFTERNOON INTO SUNDAY EVENING.
WHILE THE 12Z RUN OF THE GFS IS LESS THAN IMPRESSIVE WITH THE
RIDGE...THE 00Z RUNS OF THE ECMWF AND TO A GREATER EXTENT THE
CANADIAN MODEL.
OTHERWISE PAST SUNDAY EVENING WE GET BACK INTO THE PERSISTENT NW
FLOW AGAIN ALOFT...THANKS TO THE MAIN 500MB LOW SLIDING FROM N
CENTRAL CANADA FRIDAY NIGHT...ACROSS JAMES BAY SATURDAY NIGHT...AND
INTO QUEBEC SUNDAY/SUNDAY NIGHT. WHILE THE MAIN LOW RETREATS BACK
N...A MODERATED PIECE OF THE COLDER AIR WILL BE ABLE TO DIVE IN
MONDAY NIGHT THROUGH MUCH OF THE UPCOMING WORK WEEK /AT LEAST
ACCORDING TO THE 12Z ECMWF/. GIVEN THE PERSISTENT N-NNW FLOW...HAVE
INCREASED POPS FOR MONDAY NIGHT THROUGH TUESDAY ALONG LAKE SUPERIOR
TO LIKELY AND DEFINITE CATEGORIES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1151 PM EST TUE JAN 14 2014
LAKE EFFECT SNOW SHOWERS WILL CONTINUE THROUGH THE MORNING AT ALL
SITES WITH MVFR CONDITIONS AT ALL SITES THROUGH MID MORNING. ONLY
EXCEPTION WILL BRIEFLY BE AT SAW EARLY THIS MORNING AS A STRONGER
LAKE EFFECT SNOW BAND SLOWLY MOVES EAST OF THE AREA AND IN THIS BAND
WILL BE IFR CONDITIONS. AS WINDS BACK TO THE SW...LAKE EFFECT WILL
END AND CONDITIONS WILL GO TO VFR AT ALL SITES IN THE AFTERNOON.
NEXT DISTURBANCE ARRIVES BY EVENING WITH MVFR CONDITIONS AND LIGHT
SNOW BREAKING OUT IN THE EVENING AT ALL SITES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 453 AM EST WED JAN 15 2014
A LOW CENTERED OVER CENTRAL LAKE HURON WILL DEPART THE GREAT LAKES
REGION TODAY...ALLOWING A HIGH PRESSURE RIDGE TO QUICKLY SLIDE OVER
LAKE SUPERIOR. THIS WILL LEAD TO WEAKENING WINDS THIS
MORNING...WHICH WILL THEN QUICKLY BACK TO THE SOUTHWEST AND
INCREASE THIS AFTERNOON AND EVENING AHEAD OF ANOTHER CLIPPER
SYSTEM. THINK THE SUSTAINED WINDS WILL BE IN THE 25-30KT RANGE OVER
THE WESTERN LAKE THIS EVENING WITH FREQUENT ENOUGH GUSTS TO 35
KNOTS TO SUPPORT ISSUING A GALE WARNING FOR ABOUT A 6-9HR PERIOD.
SINCE THE LOW WILL BE WEAKENING AS IT MOVES TOWARDS LAKE
SUPERIOR...AM A LITTLE UNCERTAIN ON HOW STRONG THE WINDS WILL BE
OVER THE EASTERN LAKE...BUT SHOULD SUPPORT AT LEAST SOME GALE FORCE
GUSTS TO 35KTS. THIS LOW WILL MOVE OVER WESTERN LAKE SUEPRIOR
OVERNIGHT AND DECREASE WINDS ACROSS THE LAKE. AS IT MOVES ACROSS
UPPER MICHIGAN ON THURSDAY AND SLOWLY WEAKENS...WINDS WILL TURN TO
THE NORTH FROM WEST TO EAST THURSDAY AFTERNOON THROUGH THURSDAY
NIGHT. THERE IS THE POTENTIAL FOR SOME GALES TO 35KTS ON THE BACK
SIDE OF THIS LOW...ESPECIALLY OVER WESTERN LAKE SUPERIOR WHEN THE
LOW IS STILL A LITTLE STRONGER. THIS LOW WILL DEPART THE AREA ON
FRIDAY AND ALLOW A WEAK HIGH PRESSURE RIDGE TO SLIDE ACROSS THE
LAKE FRIDAY AFTERNOON AND FRIDAY NIGHT. A COUPLE OTHER CLIPPER
SYSTEMS WILL BE NEAR THE GREAT LAKES REGION THIS WEEKEND. THE
STRONGEST ONE WILL MOVE THROUGH NORTHEAST ONTARIO ON SATURDAY NIGHT
AND DRAG A COLD FRONT ACROSS LAKE SUPERIOR LATE SATURDAY NIGHT AND
SUNDAY MORNING...WHICH WILL BRING ANOTHER POSSIBILITY OF NORTHWEST
GALES TO 35KTS.
HEAVY FREEZING SPRAY SHOULD DIMINISH THIS MORNING BUT THEN COME
BACK LATE THIS AFTERNOON AND EVENING. DID ISSUES A HEAVY FREEZING
SPRAY WARNING FOR THE WEST HALF OF THE LAKE TO ACCOUNT FOR THAT.
WHEN THE WINDS TURN NORTHERLY THURSDAY NIGHT INTO FRIDAY...SHOULD
SEE ANOTHER PERIOD OF HEAVY FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST THIS MORNING FOR
MIZ006.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
LSZ248>251-265>267.
GALE WARNING FROM 10 PM THIS EVENING TO 4 AM EST THURSDAY FOR
LSZ266-267.
HEAVY FREEZING SPRAY WARNING FROM 5 PM EST /4 PM CST/ THIS
AFTERNOON TO 1 AM EST /MIDNIGHT CST/ THURSDAY FOR LSZ162-
263-264.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR
LSZ244-245-263-264.
GALE WARNING FROM 7 PM THIS EVENING TO 1 AM EST THURSDAY FOR
LSZ263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KF
AVIATION...07
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1155 PM EST TUE JAN 14 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 359 PM EST TUE JAN 14 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
FROM HUDSON BAY INTO THE CNTRL CONUS. A POTENT SHORTWAVE TROUGH
LOCATED OVER SRN WI WAS MOVING TOWARD SRN LOWER MI. AT THE SFC
CIRCULATION AROUND A 999 MB LOW PRES OVER E CNTRL WI RESULTED IN
STRONG NE WINDS INTO SRN UPPER MI. INCREASING NRLY WINDS ACROSS LAKE
SUPERIOR ALONG WITH 850 MB TEMPS IN THE -13C TO -16C RANGE SUPPORTED
LIGHT LES FOR LOCATIONS FAVORED BY NNE WINDS. STRONG 700-500 MB
QVECTOR CONV AND FGEN (FN/FS CONV) NEAR THE SHRTWV PIVOT POINT HAS
PRODUCED HEAVY SNOWFALL RATES OF AN INCH OR TWO PER HOUR OVER FAR
SRN UPPER (MNM) MI WHERE 7 INCHES HAD FALLEN BY 20Z. THIS ALSO
ALIGNED WELL WITH THE SRN EXTENT OF THE COLDER CLOUD TOPS...PER IR
LOOP.
LATE THIS AFTERNOON AND TONIGHT...SATELLITE/RADAR TRENDS AND SHORT
RANGE MODELS SUGGEST THAT THE COMMA HEAD PORTION OF THE SHRTWV WILL
MOVE INTO LAKE MI THIS EVENING BTWN 00Z-03Z AND DRAG THE BACK END OF
THE SNOW OUT OF THE SRN CWA. UNTIL THEN...MODERATE TO HEAVY SNOW
WILL CONTINUE OVER THE SOUTH ALONG WITH NE WINDS GUSTING TO AROUND
30 MPH. EXPECT THE LES IN CONVERGENT NRLY FLOW INTO WRN ALGER COUNTY
TO INCREASE AS THE DEEPER MOISTURE WITH THE SYNOPTIC SYSTEM EDGES
SLOWLY NORTHWARD. ALTHOUGH THE DEEPER MOISTURE WILL DEPART AFT
06Z...INSTABILITY WILL INCREASE AS CAA DROPS 850 MB TEMPS TO AROUND
-17C. MODERATE SNOWFALL AMOUNTS IN THE 3 TO 5 INCH RANGE ARE
EXPECTED MAINLY NEAR AU TRAIN/EBEN/CHATHAM...PER CONSENSUS OF HIGHER
RES MODELS. OVER THE WEST...INVERSION HEIGHTS AROUND 3K FT SHOULD
LIMIT SNOW AMOUNTS TO LESS THAN AN INCH.
WED....MID/UPPER LEVEL RIDGING WILL DEVELOP OVER THE NRN LAKES AHEAD
OF THE NEXT SHRTWV DIVING TOWARD SRN MANITOBA AND NRN MN. AT THE
SURFACE...A RIDGE FROM MN INTO NW ONTARIO WILL BUILD TOWARD THE SRN
GREAT LAKES AS A DEEP CLIPPER LOW MOVES TO NEAR LAKE WINNIPEG.
THIS WILL LEAD TO NORTH-NORTHWEST WINDS ACROSS LAKE SUPERIOR AND
WITH 850MB TEMPS AROUND -16C THERE WILL BE ENOUGH LAKE INSTABILITY
AND LOW LEVEL MOISTURE FOR LINGERING LAKE EFFECT. BUT WITH THE
SURFACE RIDGE QUICKLY SLIDING THROUGH THE UPPER GREAT LAKES...EXPECT
WINDS TO QUICKLY BACK THROUGH THE DAY. THE BACKING WINDS...ALONG
WITH DRIER LOW LEVEL AIR WILL BRING AN END TO THE LAKE EFFECT OVER
THE WEST AROUND EARLY AFTERNOON AND THEN OVER THE EAST BY LATE
AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 446 PM EST TUE JAN 14 2014
RIDGE WEST...TROUGH EAST. THE PATTERN REMAINS THROUGH THROUGH MUCH
OF THE LONG TERM PERIOD.
FOR AN OVERVIEW OF WHAT WILL BE HAPPENING ALOFT...THE 500MB LOW OVER
N MANITOBA AT 00Z THURSDAY WILL SWEEP INTO CENTRAL ONTARIO AND THE W
HALF OF LAKE SUPERIOR BY 12Z THURSDAY. AT THAT POINT THE LOW WILL
SLOW DOWN QUITE A BIT...AND REMAIN ACROSS THE UPPER GREAT LAKES
THROUGH THE DAY THURSDAY...BEFORE THE LINGERING TROUGH SLOWLY EXITS
ACROSS EASTERN ONTARIO AND LAKE HURON FRIDAY AND FRIDAY NIGHT. THIS
WILL KEEP NNW FLOW ALOFT ACROSS LAKE SUPERIOR AND UPPER MI FROM
FRIDAY AFTERNOON THROUGH SUNDAY MONDAY.
AS FOR SPECIFICS...THE SFC LOW NEAR THE S MANITOBA/ONTARIO BORDER
JUST PRIOR TO 06Z THURSDAY SHOULD SHIFT SE INTO S CENTRAL LAKE
SUPERIOR/AND THE W HALF OF UPPER MI BY 18Z. S-SSW WINDS WILL REMAIN
IN THE 10-20KT RANGE WEDNESDAY NIGHT. WARMER AIR WILL BE ABLE TO
SWEEP IN FOR THURSDAY...WITH HIGHS IN THE UPPER 20S...THANKS TO THE
MID AFTERNOON LOW PASSAGE ALLOWING 850MB TEMPS TO RISE INTO THE -5
TO -7F RANGE. EXPECT THE SFC LOW TO EXIT FAR E UPPER MI THURSDAY
NIGHT INTO FRIDAY. GIVEN THE SLOW PROGRESS OF THE LOW...LOOK FOR A
SIGNIFICANT BREAK BETWEEN THE STRONG W-SSW WINDS WEDNESDAY NIGHT AND
COLDER AIR RUSHING IN THE N-NNW WINDS THURSDAY NIGHT INTO FRIDAY.
HIGH FRIDAY SHOULD BE ON THE ORDER OF 15F COOLER OVER W AND CENTRAL
UPPER MI...WHILE ONLY A COULD DEGREES COOLER E.
ALTHOUGH FAR W LAKE SUPERIOR MAY BE PRETTY FROZEN...THERE IS LIKELY
PLENTY OF RELATIVELY WARM OPEN WATER STILL AVAILABLE N OF THE
APOSTLE ISLANDS TO ALLOW THE MAINLY N FLOW OF COLD AIR TO PRODUCE
MODERATE LES FROM LATE THURSDAY AFTERNOON THROUGH THE DAY FRIDAY.
THE FLOW BECOMES MORE W-NW OVER W LAKE SUPERIOR FRIDAY EVENING AS
WAA TAKES HOLD AND 850MB TEMPS THAT WERE ON THE ORDER OF -14 TO -17C
QUICKLY JUMP UP TO AROUND -10C. LES WILL CONTINUE TO PERSIST NEAR
AND E OF MUNISING INTO SATURDAY. THERE IS STILL A QUESTION AS TO HOW
LONG THE FETCH REMAINS FAVORABLE FOR THIS AREA...AS THE 12Z ECMWF IS
GOING WITH A MORE W FLOW NEAR THE SFC...WHICH WOULD KEEP THE BEST
CHANCE OF LES ONLY RIGHT ALONG THE SHORELINE E SATURDAY...IF NOT OFF
SHORE.
A SIZABLE RIDGE EXTENDING UP FROM THE 4-CORNERS REGION THROUGH THE
DAKOTAS AND SOUTH CENTRAL CANADA SUNDAY MORNING WILL BRIEFLY MOVE
ACROSS THE UPPER GREAT LAKES SUNDAY AFTERNOON INTO SUNDAY EVENING.
WHILE THE 12Z RUN OF THE GFS IS LESS THAN IMPRESSIVE WITH THE
RIDGE...THE 00Z RUNS OF THE ECMWF AND TO A GREATER EXTENT THE
CANADIAN MODEL.
OTHERWISE PAST SUNDAY EVENING WE GET BACK INTO THE PERSISTENT NW
FLOW AGAIN ALOFT...THANKS TO THE MAIN 500MB LOW SLIDING FROM N
CENTRAL CANADA FRIDAY NIGHT...ACROSS JAMES BAY SATURDAY NIGHT...AND
INTO QUEBEC SUNDAY/SUNDAY NIGHT. WHILE THE MAIN LOW RETREATS BACK
N...A MODERATED PIECE OF THE COLDER AIR WILL BE ABLE TO DIVE IN
MONDAY NIGHT THROUGH MUCH OF THE UPCOMING WORK WEEK /AT LEAST
ACCORDING TO THE 12Z ECMWF/. GIVEN THE PERSISTENT N-NNW FLOW...HAVE
INCREASED POPS FOR MONDAY NIGHT THROUGH TUESDAY ALONG LAKE SUPERIOR
TO LIKELY AND DEFINITE CATEGORIES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1151 PM EST TUE JAN 14 2014
LAKE EFFECT SNOW SHOWERS WILL CONTINUE THROUGH THE MORNING AT ALL
SITES WITH MVFR CONDITIONS AT ALL SITES THROUGH MID MORNING. ONLY
EXCEPTION WILL BRIEFLY BE AT SAW EARLY THIS MORNING AS A STRONGER
LAKE EFFECT SNOW BAND SLOWLY MOVES EAST OF THE AREA AND IN THIS BAND
WILL BE IFR CONDITIONS. AS WINDS BACK TO THE SW...LAKE EFFECT WILL
END AND CONDITIONS WILL GO TO VFR AT ALL SITES IN THE AFTERNOON.
NEXT DISTURBANCE ARRIVES BY EVENING WITH MVFR CONDITIONS AND LIGHT
SNOW BREAKING OUT IN THE EVENING AT ALL SITES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 PM EST TUE JAN 14 2014
NORTH WINDS OF 30 KNOTS OVER ERN LAKE SUPERIOR TONIGHT AS A SFC LOW
PASSES SOUTH AND EAST OF REGION WILL PRODUCE HEAVY FREEZING SPRAY.
EXPECT THE WINDS TO DIMINISH BRIEFLY ON WEDNESDAY AS A HIGH PRESSURE
RIDGE CROSSES THE REGION. LOW PRESSURE CROSSING LAKE WINNIPEG LATE
WEDNESDAY AFTERNOON WILL THEN SINK ACROSS LAKE SUPERIOR ON THURSDAY.
SW GALES OF 35 KTS ARE POSSIBLE WEDNESDAY NIGHT OVER EASTERN SECTIONS.
N-NW GALES OF 35 KTS ARE ALSO POSSIBLE LATE THURSDAY AFTERNOON THROUGH
FRIDAY MORNING IN WAKE OF A COLD FRONT FOLLOWING THE LOW. THE LOW
WILL WEAKEN AS IT DRIFTS EASTWARD INTO SOUTHERN ONTARIO THROUGH THE
DAY FRIDAY...WHILE KEEPING A WEAK TROUGH OVER LAKE SUPERIOR. HEAVY
FREEZING SPRAY WILL BE POSSIBLE THURSDAY NIGHT THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST WEDNESDAY FOR MIZ006.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST WEDNESDAY FOR
LSZ248>251-265>267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR LSZ244-
245-263-264.
LAKE MICHIGAN...
GALE WARNING UNTIL 9 AM EST WEDNESDAY FOR LMZ250.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS RALEIGH NC
321 AM EST WED JAN 14 2014
.SYNOPSIS...WEAK HIGH PRESSURE WILL RIDGE ACROSS THE SOUTHEAST THIS
MORNING...THEN GIVE WAY TO AN APPALACHIAN LEE SURFACE TROUGH THIS
AFTERNOON. AN ARCTIC COLD FRONT AND ACCOMPANYING STRONG UPPER LEVEL
TROUGH WILL THEN CROSS THE MIDDLE ATLANTIC REGION AND INDUCE COASTAL
LOW PRESSURE DEVELOPMENT THIS EVENING AND OVERNIGHT...FOLLOWED BY
BRIEF HIGH PRESSURE ON THU.
&&
.NEAR TERM /TONIGHT AND WEDNESDAY/...
AS OF 900 PM TUESDAY...
TONIGHT:
MAIN FORECAST CHALLENGE FOR TONIGHT IS THE EXTENT/DURATION OF FOG.
CLEAR SKIES AND WEAK SFC RIDGING EXTENDING INTO THE AREA FROM THE SW
HAS PROMOTED CALM SFC WINDS. SOME PATCHY DENSE FOG... HAS ALREADY
DEVELOPED ACROSS COASTAL COUNTIES WHERE LOW-LEVELS REMAIN QUIET
MOIST...PER 00Z/15 MHX RAOB...WITH ONLY MINOR/WEAK ADVECTION OF DRY
AIR FROM THE WEST COMPARED TO WESTERN PORTIONS OF THE STATE(PER
LATEST GSO RAOB). MUCH OF THE MODEL GUIDANCE INDICATES DEWPOINTS
WILL FALL OVERNIGHT...WHICH WOULD INHIBIT FOG...PARTICULARLY DENSE
FOG. HOWEVER THE LATEST RAP GUIDANCE KEEPS DEWPOINTS PRETTY MUCH
STATUS QUO OVERNIGHT WITH NO DRIER AIR WORKING IN FROM THE WEST
WHICH IS VERY PLAUSIBLE GIVEN WEAK SFC WINDS. WILL CONTINUE TO
MONITOR THESE TRENDS...AND IF THE DRIER DOES NOT DOES NOT BUILD
EAST...A DENSE FOG ADVISORY MAY NEED TO BE ISSUED FOR CENTRAL AND
EASTERN PORTIONS OF THE FORECAST AREA. LOWS RANGING FROM LOWER TO
MID 30 NW TO UPPER 30S TO AROUND 40 SE.
FOR THE DAY WEDNESDAY...THE SURFACE FRONT GRADUALLY MOVES EAST INTO
CENTRAL NORTH CAROLINA...THEN SLOWS AS THE UPPER TROUGH SHARPENS...
AND THE SOUTHWEST JET AT 300MB INCREASES TO 135KT LATE IN THE DAY
OVER CENTRAL NORTH CAROLINA HELPING TO PROVIDE FOR SLOWLY DEEPENING
LOW PRESSURE OFF THE COAST. THE RIGHT ENTRANCE REGION OF A 90KT
500MB JET MOVES NEAR OR INTO THE NORTHWEST PIEDMONT LATE IN THE DAY.
MOISTURE IS NOT GREAT...WITH K INDICES ONLY ON THE GFS BARELY BEYOND
SINGLE FIGURES AND WITH AN 850MB THETA-E RIDGE THAT IS CERTAINLY
WEAK COMPARED TO RECENT PRECIPITATION EVENTS. HOWEVER...LIFT DOES
INCREASE LATE WITH THE APPROACH OF THE MID-LEVEL JET. QPF FROM THE
NAM...GFS...AND ECMWF IS LIMITED WITH ONLY LIGHT...NEAR HUNDREDTH
VALUES...MOSTLY WEST OF U.S. 1 VERY LATE IN THE DAY IF THERE IS ANY
AT ALL. NAM AND GFS BUFR SOUNDINGS SUGGEST ENOUGH OF A COMBINATION
OF MID- AND LOW-LEVEL MOISTURE THAT SOME LIGHT PRECIPITATION COULD
BEGIN REACHING THE GROUND AFTER 21Z IN THOSE AREAS...BETTER CHANCE
IN A RELATIVE SENSE TOWARD THE IMMEDIATE TRIAD. AS THE GRADIENT
TIGHTENS LATE IN THE DAY OVER THE WESTERN PART OF THE STATE...AN
INCREASING NORTHERLY SURFACE FLOW...COUPLED WITH ANY SPOTTY
PRECIPITATION...COULD RESULT IN RAPIDLY COOLING TEMPERATURES LATE IN
THE DAY IN THE TRIAD. BEFORE THEN...1000-850MB THICKNESSES SUPPORT
HIGHS CLOSE TO THE MOS GUIDANCE CONSENSUS...IN THE LOWER 50S
NORTHWEST TO AROUND 60 SOUTHEAST UNDER A PARTLY SUNNY SKY ON AVERAGE
FOR THE ENTIRE DAY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 250 PM TUESDAY...
MULTIPLE SHORTWAVE TROUGHS WILL DIVE INTO THE SOUTHEASTERN U.S.
DURING THE SHORT-TERM PERIOD CULMINATING IN A STRONG NEGATIVELY
TILTED TROUGH THAT WIL SWING THROUGH THE CAROLINAS ON THURSDAY
MORNING. MEANWHILE AN ARCTIC COLD FRONT WILL MOVE EAST ACROSS
CENTRAL NC DURING THE LATE AFTERNOON WEDNESDAY AND WEDNESDAY NIGHT.
AS THE IMPRESSIVE MID LEVEL WAVE WITH STRONG HEIGHT FALLS AND A
100+KT JET AT 500 HPA APPROACHES THE ARCTIC COLD FRONT AND THE
STALLED FRONT NEAR THE GULF STREAM...CYCLOGENESIS WILL COMMENCE
LATE WEDNESDAY NIGHT OFFSHORE OF CAPE FEAR.
FORECAST CONFIDENCE REMAINS BELOW AVERAGE FOR THIS PERIOD AS
GUIDANCE HAS BEEN EVOLVING IN THE HANDLING OF THE ARCTIC COLD FRONT
AND THE RESULTANT CYCLOGENESIS. IT SHOULD BE NOTED THAT GUIDANCE IS
TRENDING SLOWER WITH A MORE AMPLIFIED UPPER AIR PATTERN AND A
STRONGER SURFACE SYSTEM ALBEIT WITH VARYING QPF SCENARIOS. THE MOST
LIKELY SCENARIO AT THIS POINT IS FOR AN AREA OF MAINLY LIGHT
PRECIPITATION TO SPREAD EAST OUT OF THE NC FOOTHILLS LATE WEDNESDAY
AFTERNOON AND MOVE INTO THE WESTERN PIEDMONT TOWARD SUNSET. WHILE
THE PRECIPITATION WILL FALL BEHIND THE ARCTIC FRONT...THE NEAR
SURFACE TEMPERATURES WIL BE SUFFICIENTLY WARM AND DEEP TO RESULT IN
A RAIN PTYPE THROUGH AT LEAST INTO EARLY EVENING. THE SURGE OF COLD
AIR EASTWARD DURING THE LATE EVENING AND OVERNIGHT SHOULD DRIVE A
CHANGEOVER TO SNOW FROM WEST TO EAST OVERNIGHT. PRECIPITATION
AMOUNTS ARE EXPECTED TO BE LIGHT AND LESS THAN IF NOT MUCH LESS THAN
A TENTH OF AN INCH....MAINLY WEST OF U.S. ROUTE 1 WITH LITTLE IF ANY
PRECIPITATION EAST ACROSS THE COASTAL PLAIN. THIS COULD RESULT IN A
LIGHT COATING OF SNOW BY THURSDAY MORNING IN THE NORTHERN AND
NORTHWEST PIEDMONT BUT THIS IS LIKELY A MORE EXTREME SCENARIO WITH
MOST LOCATIONS ONLY OBSERVING A PERIOD OF LIGHT LIGHT SNOW FOR A FEW
HOURS WITH NO ACCUMULATION. TEMPERATURES BY THURSDAY MORNING WILL
FALL TO OR BELOW FREEZING ACROSS ALL OF THE RAH CWA WITH MINIMUMS
RANGING FROM 25 IN THE NORTHWEST PIEDMONT TO AROUND 30 IN THE
COASTAL PLAIN.
GUIDANCE CONTINUES TO TREND SLOWER WITH LIGHT PRECIPITATION NOW
PERSISTING INTO THURSDAY MORNING AS IT GRADUALLY SHIFTS EAST. QPF
AMOUNTS AGAIN ARE EXPECTED TO BE LIGHT AND LESS THAN A TENTH OF AN
INCH. INITIALLY THE PREDOMINANT P-TYPE WILL LIKELY BE SNOW THURSDAY
MORNING WITH SURFACE TEMPERATURES CONFINED TO THE 30S DURING THE
MORNING BUT NAM/GFS BUFR SOUNDINGS SUGGEST THAT THE MOISTURE MAY NOT
BE SUFFICIENTLY DEEP TO EXTEND IN THE ICE NUCLEATION REGION AND
ABOVE FREEZIN TEMPS WILL PROBABLY RESULT IN MORE OF A RIAN.SBNOW
MIX. REGARDLESS THE LIGHT NATURE OF THE PRECIPITATION SHOULD
PRECLUDE ANY APPRECIABLE ACCUMULATION DURING THE DAY THURSDAY. WE
WILL NEED TO MONITOR THE INTENSITY AND TRACK OF THE DEVELOPING
SURFACE LOW AS ONLY A SMALL WESTWARD SHIFT WOULD POTENTIALLY RESULT
IN NOTICEABLY MORE PRECIPITATION IN LOCATIONS EAST OF U.S. 1 ON
THURSDAY. ALL OF THE PRECIPITATION SHOULD END BY EARLY AFTERNOON
WITH HIGHS EVENTUALLY REACHING THE 40-45 RANGE BY LATE IN THE DAY.
DRY WEATHER WITH CLEARING SKIES ARE EXPECTED ON THURSDAY NIGHT. LOWS
SHOULD FALL INTO THE 26-32 RANGE BY FRIDAY MORNING. -BLAES
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 258 AM WEDNESDAY...
COLD FRONT WILL CROSS THE AREA LATE FRIDAY/EARLY SATURDAY. THERE IS
A CHANCE FOR LIGHT PRECIPITATION... RAIN POTENTIALLY CHANGING
TO/MIXING WITH A PERIOD OF LIGHT SNOW... AS THE UPPER LEVEL
SHORTWAVE AXIS CROSSES THE AREA. STRONG COLD ADVECTION WILL
IMMEDIATELY FOLLOW THE FRONTAL PASSAGE... KEEPING HIGHS IN THE UPPER
30S TO LOW 40S. SATURDAY. A CLIPPER SYSTEM MOVES ACROSS THE AREA
FROM THE NORTHWEST EARLY SUNDAY... WITH LITTLE MOISTURE AND WESTERLY
FLOW... PRECIP LOOKS UNLIKELY. HIGHS IN THE MID 40S. FLOW BECOMES
SOUTHWESTERLY ON MONDAY... WITH THICKNESSES REBOUNDING... HIGHS IN
THE 50S... AND NEAR NORMAL TEMPERAUTRES CONTINUE INTO TUESDAY.
NORTHERN STREAM WAVE DIGS SOUTHWARD AT THE END OF THE PERIOD...
DEPENDING ON THE DEGREE OF PHASING WITH A WEAK SOUTHERN STREAM
WAVE... MAY BRING ANOTHER CHANCE AT PRECIPITATION.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 130 AM WEDNESDAY...
THE LOW LEVEL FLOW HAS ALREADY BACKED TO SSW IN THE LEE OF THE
APPALACHIANS/OVER THE CAROLINAS...AND AS SUCH...THE LOW LEVEL
MOISTURE OVER THE CENTRAL AND EASTERN CAROLINAS- AND ASSOCIATED
VLIFR VISIBILITY RESTRICTIONS AND CEILINGS - SHOULD ONLY GET WORSE
AND EXPAND NORTHWESTWARD THROUGHOUT THE MORNING. IN OTHER
WORDS...THERE IS NO DRY AIR COMING OUR WAY TO DISPERSE THE LOW
CLOUDS AND FOG THIS MORNING. THE LOW LEVEL MOISTURE IS CONSEQUENTLY
APT TO STICK AROUND FOR THE BETTER PART OF THE MORNING TO MIDDAY
HOURS...BEFORE MIXING/SCATTERING THROUGH MVFR BETWEEN 14-16Z...AND
TO VFR THEREAFTER.
ATTENTION WILL THEN TURN TO A SHARPENING UPPER LEVEL TROUGH TO OUR
WEST...AND AN ACCOMPANYING ARCTIC COLD FRONT THAT WILL CROSS CENTRAL
NC THIS EVENING AND TONIGHT. SCATTERED RAIN SHOWERS WILL BE POSSIBLE
IN THE VICINITY OF THE FRONT LATE THIS AFTERNOON AT TRIAD TERMINALS
AND THIS EVENING ELSEWHERE...FOLLOWED BY A LARGER BAND OF LIGHT
PRECIPITATION THAT WILL OVERSPREADS OUR REGION OVERNIGHT. WITH COLD
AIR RUSHING IN BEHIND THE ARCTIC FRONT...THAT BAND OF LIGHT
PRECIPITATION WILL FALL AS LIGHT SNOW...AFTER INITIALLY A RAIN/SNOW
MIX AT THE ONSET. MVFR CEILINGS AND MVFR-IFR VISIBILITY RESTRICTIONS
WILL ACCOMPANY THE LIGHT SNOW BAND. IN ADDITION...NORTHWEST WINDS
WILL INCREASE INTO THE 12-15 KT RANGE WITH GUSTS OF 20-25 KTS AS THE
DENSE COLD AIR RUSHES IN BEHIND THE FRONT.
OUTLOOK: SUB-VFR CONDITIONS AT LIGHT SNOW WILL END FROM WEST TO EAST
BETWEEN 09-15Z THU...FOLLOWED BY CLEAR VFR CONDITIONS FOR THE REST
OF THU. ANOTHER FRONTAL SYSTEM WILL BRING A CHANCE OF RAIN CHANGING
TO SNOW...AND ASSOCIATED SUB-VFR CONDITIONS...LATE FRI-FRI NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...CBL/DJF
SHORT TERM...BLAES
LONG TERM...SEC
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
134 AM EST WED JAN 14 2014
.SYNOPSIS...WEAK HIGH PRESSURE WILL RIDGE ACROSS THE SOUTHEAST THIS
MORNING...THEN GIVE WAY TO AN APPALACHIAN LEE SURFACE TROUGH THIS
AFTERNOON. AN ARCTIC COLD FRONT AND ACCOMPANYING STRONG UPPER LEVEL
TROUGH WILL THEN CROSS THE MIDDLE ATLANTIC REGION AND INDUCE COASTAL
LOW PRESSURE DEVELOPMENT THIS EVENING AND OVERNIGHT...FOLLOWED BY
BRIEF HIGH PRESSURE ON THU.
&&
.NEAR TERM /TONIGHT AND WEDNESDAY/...
AS OF 900 PM TUESDAY...
TONIGHT:
MAIN FORECAST CHALLENGE FOR TONIGHT IS THE EXTENT/DURATION OF FOG.
CLEAR SKIES AND WEAK SFC RIDGING EXTENDING INTO THE AREA FROM THE SW
HAS PROMOTED CALM SFC WINDS. SOME PATCHY DENSE FOG... HAS ALREADY
DEVELOPED ACROSS COASTAL COUNTIES WHERE LOW-LEVELS REMAIN QUIET
MOIST...PER 00Z/15 MHX RAOB...WITH ONLY MINOR/WEAK ADVECTION OF DRY
AIR FROM THE WEST COMPARED TO WESTERN PORTIONS OF THE STATE(PER
LATEST GSO RAOB). MUCH OF THE MODEL GUIDANCE INDICATES DEWPOINTS
WILL FALL OVERNIGHT...WHICH WOULD INHIBIT FOG...PARTICULARLY DENSE
FOG. HOWEVER THE LATEST RAP GUIDANCE KEEPS DEWPOINTS PRETTY MUCH
STATUS QUO OVERNIGHT WITH NO DRIER AIR WORKING IN FROM THE WEST
WHICH IS VERY PLAUSIBLE GIVEN WEAK SFC WINDS. WILL CONTINUE TO
MONITOR THESE TRENDS...AND IF THE DRIER DOES NOT DOES NOT BUILD
EAST...A DENSE FOG ADVISORY MAY NEED TO BE ISSUED FOR CENTRAL AND
EASTERN PORTIONS OF THE FORECAST AREA. LOWS RANGING FROM LOWER TO
MID 30 NW TO UPPER 30S TO AROUND 40 SE.
FOR THE DAY WEDNESDAY...THE SURFACE FRONT GRADUALLY MOVES EAST INTO
CENTRAL NORTH CAROLINA...THEN SLOWS AS THE UPPER TROUGH SHARPENS...
AND THE SOUTHWEST JET AT 300MB INCREASES TO 135KT LATE IN THE DAY
OVER CENTRAL NORTH CAROLINA HELPING TO PROVIDE FOR SLOWLY DEEPENING
LOW PRESSURE OFF THE COAST. THE RIGHT ENTRANCE REGION OF A 90KT
500MB JET MOVES NEAR OR INTO THE NORTHWEST PIEDMONT LATE IN THE DAY.
MOISTURE IS NOT GREAT...WITH K INDICES ONLY ON THE GFS BARELY BEYOND
SINGLE FIGURES AND WITH AN 850MB THETA-E RIDGE THAT IS CERTAINLY
WEAK COMPARED TO RECENT PRECIPITATION EVENTS. HOWEVER...LIFT DOES
INCREASE LATE WITH THE APPROACH OF THE MID-LEVEL JET. QPF FROM THE
NAM...GFS...AND ECMWF IS LIMITED WITH ONLY LIGHT...NEAR HUNDREDTH
VALUES...MOSTLY WEST OF U.S. 1 VERY LATE IN THE DAY IF THERE IS ANY
AT ALL. NAM AND GFS BUFR SOUNDINGS SUGGEST ENOUGH OF A COMBINATION
OF MID- AND LOW-LEVEL MOISTURE THAT SOME LIGHT PRECIPITATION COULD
BEGIN REACHING THE GROUND AFTER 21Z IN THOSE AREAS...BETTER CHANCE
IN A RELATIVE SENSE TOWARD THE IMMEDIATE TRIAD. AS THE GRADIENT
TIGHTENS LATE IN THE DAY OVER THE WESTERN PART OF THE STATE...AN
INCREASING NORTHERLY SURFACE FLOW...COUPLED WITH ANY SPOTTY
PRECIPITATION...COULD RESULT IN RAPIDLY COOLING TEMPERATURES LATE IN
THE DAY IN THE TRIAD. BEFORE THEN...1000-850MB THICKNESSES SUPPORT
HIGHS CLOSE TO THE MOS GUIDANCE CONSENSUS...IN THE LOWER 50S
NORTHWEST TO AROUND 60 SOUTHEAST UNDER A PARTLY SUNNY SKY ON AVERAGE
FOR THE ENTIRE DAY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 250 PM TUESDAY...
MULTIPLE SHORTWAVE TROUGHS WILL DIVE INTO THE SOUTHEASTERN U.S.
DURING THE SHORT-TERM PERIOD CULMINATING IN A STRONG NEGATIVELY
TILTED TROUGH THAT WIL SWING THROUGH THE CAROLINAS ON THURSDAY
MORNING. MEANWHILE AN ARCTIC COLD FRONT WILL MOVE EAST ACROSS
CENTRAL NC DURING THE LATE AFTERNOON WEDNESDAY AND WEDNESDAY NIGHT.
AS THE IMPRESSIVE MID LEVEL WAVE WITH STRONG HEIGHT FALLS AND A
100+KT JET AT 500 HPA APPROACHES THE ARCTIC COLD FRONT AND THE
STALLED FRONT NEAR THE GULF STREAM...CYCLOGENESIS WILL COMMENCE
LATE WEDNESDAY NIGHT OFFSHORE OF CAPE FEAR.
FORECAST CONFIDENCE REMAINS BELOW AVERAGE FOR THIS PERIOD AS
GUIDANCE HAS BEEN EVOLVING IN THE HANDLING OF THE ARCTIC COLD FRONT
AND THE RESULTANT CYCLOGENESIS. IT SHOULD BE NOTED THAT GUIDANCE IS
TRENDING SLOWER WITH A MORE AMPLIFIED UPPER AIR PATTERN AND A
STRONGER SURFACE SYSTEM ALBEIT WITH VARYING QPF SCENARIOS. THE MOST
LIKELY SCENARIO AT THIS POINT IS FOR AN AREA OF MAINLY LIGHT
PRECIPITATION TO SPREAD EAST OUT OF THE NC FOOTHILLS LATE WEDNESDAY
AFTERNOON AND MOVE INTO THE WESTERN PIEDMONT TOWARD SUNSET. WHILE
THE PRECIPITATION WILL FALL BEHIND THE ARCTIC FRONT...THE NEAR
SURFACE TEMPERATURES WIL BE SUFFICIENTLY WARM AND DEEP TO RESULT IN
A RAIN PTYPE THROUGH AT LEAST INTO EARLY EVENING. THE SURGE OF COLD
AIR EASTWARD DURING THE LATE EVENING AND OVERNIGHT SHOULD DRIVE A
CHANGEOVER TO SNOW FROM WEST TO EAST OVERNIGHT. PRECIPITATION
AMOUNTS ARE EXPECTED TO BE LIGHT AND LESS THAN IF NOT MUCH LESS THAN
A TENTH OF AN INCH....MAINLY WEST OF U.S. ROUTE 1 WITH LITTLE IF ANY
PRECIPITATION EAST ACROSS THE COASTAL PLAIN. THIS COULD RESULT IN A
LIGHT COATING OF SNOW BY THURSDAY MORNING IN THE NORTHERN AND
NORTHWEST PIEDMONT BUT THIS IS LIKELY A MORE EXTREME SCENARIO WITH
MOST LOCATIONS ONLY OBSERVING A PERIOD OF LIGHT LIGHT SNOW FOR A FEW
HOURS WITH NO ACCUMULATION. TEMPERATURES BY THURSDAY MORNING WILL
FALL TO OR BELOW FREEZING ACROSS ALL OF THE RAH CWA WITH MINIMUMS
RANGING FROM 25 IN THE NORTHWEST PIEDMONT TO AROUND 30 IN THE
COASTAL PLAIN.
GUIDANCE CONTINUES TO TREND SLOWER WITH LIGHT PRECIPITATION NOW
PERSISTING INTO THURSDAY MORNING AS IT GRADUALLY SHIFTS EAST. QPF
AMOUNTS AGAIN ARE EXPECTED TO BE LIGHT AND LESS THAN A TENTH OF AN
INCH. INITIALLY THE PREDOMINANT P-TYPE WILL LIKELY BE SNOW THURSDAY
MORNING WITH SURFACE TEMPERATURES CONFINED TO THE 30S DURING THE
MORNING BUT NAM/GFS BUFR SOUNDINGS SUGGEST THAT THE MOISTURE MAY NOT
BE SUFFICIENTLY DEEP TO EXTEND IN THE ICE NUCLEATION REGION AND
ABOVE FREEZIN TEMPS WILL PROBABLY RESULT IN MORE OF A RIAN.SBNOW
MIX. REGARDLESS THE LIGHT NATURE OF THE PRECIPITATION SHOULD
PRECLUDE ANY APPRECIABLE ACCUMULATION DURING THE DAY THURSDAY. WE
WILL NEED TO MONITOR THE INTENSITY AND TRACK OF THE DEVELOPING
SURFACE LOW AS ONLY A SMALL WESTWARD SHIFT WOULD POTENTIALLY RESULT
IN NOTICEABLY MORE PRECIPITATION IN LOCATIONS EAST OF U.S. 1 ON
THURSDAY. ALL OF THE PRECIPITATION SHOULD END BY EARLY AFTERNOON
WITH HIGHS EVENTUALLY REACHING THE 40-45 RANGE BY LATE IN THE DAY.
DRY WEATHER WITH CLEARING SKIES ARE EXPECTED ON THURSDAY NIGHT. LOWS
SHOULD FALL INTO THE 26-32 RANGE BY FRIDAY MORNING. -BLAES
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 315 PM TUESDAY...
THE LONG TERM PERIOD FEATURES A PROGRESSIVE PATTERN WITH SYSTEMS
DROPPING INTO THE MID ATLANTIC AND SOUTHEAST ON THE NORTHWEST ALOFT
BRINGING QUICK THREATS OF PRECIPITATION AND BRIEF SHOTS OF COLDER
AIR. THE SOUTHERN STREAM BECOMES MORE ACTIVE LATE IN THE PERIOD
SUGGESTING A MILDER PRECIPITATION EVENT POSSIBLE LATE TUESDAY.
THE NEXT STORM SYSTEM ASSOCIATED WITH ANOTHER STRONG NORTHERN STREAM
WAVE WILL MOVE THROUGH THE AREA FRIDAY NIGHT INTO EARLY SATURDAY. IT
APPEARS THE AIRMASS WILL BE SUFFICIENTLY COLD TO MAINTAIN A MENTION
OF RAIN MIXING WITH OR CHANGING TO SNOW AS COLD ARCTIC AIR PUSHES
INTO THE REGION BEHIND THE FTRONT.CONFIDENCE IN THE DETAILS
ASSOCIATED WITH THIS SYSTEM ARE RATHER LOW AS GUIDANCE IS QUITE
VARIED BUT AT THIS POINT IT IS LIKELY TO REMAIN A VERY LIGHT QPF
EVENT.
FAIR WEATHER IS EXPECTED LATER SATURDAY BEFORE THE NEXT SYSTEM IN
THE STRONG NORTHWEST FLOW ARRIVES SATURDAY NIGHT. THIS SYSTEM APPEARS
EVEN MORE MOISTURE DEPRIVED WITH A TRACK FURTHER NORTH...AND WILL
ACCORDINGLY KEEP THE FORECAST DRY. HIGHS IN THE UPPER 30S TO LOWER
40S SATURDAY WILL WARM INTO THE LOWER TO MID 40S SUNDAY AND THE
LOWER 50S BY MONDAY.
INCREASING CLOUDS ARE EXPECTED ON MONDAY AS THE SOUTHERN STREAM
BECOMES MORE ACTIVE AND A BROAD EASTERN U.S. TROUGH SHARPENS
SOMEWHATS. TEMPERATURES WILL HAVE MODIFIED SUFFICIENTLY FOR A RAIN P-
TYPE AS HIGHS TUESDAY SHOULD RANGE IN THE LOWER TO MID 50S. -BLAES
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 130 AM WEDNESDAY...
THE LOW LEVEL FLOW HAS ALREADY BACKED TO SSW IN THE LEE OF THE
APPALACHIANS/OVER THE CAROLINAS...AND AS SUCH...THE LOW LEVEL
MOISTURE OVER THE CENTRAL AND EASTERN CAROLINAS- AND ASSOCIATED
VLIFR VISIBILITY RESTRICTIONS AND CEILINGS - SHOULD ONLY GET WORSE
AND EXPAND NORTHWESTWARD THROUGHOUT THE MORNING. IN OTHER
WORDS...THERE IS NO DRY AIR COMING OUR WAY TO DISPERSE THE LOW
CLOUDS AND FOG THIS MORNING. THE LOW LEVEL MOISTURE IS CONSEQUENTLY
APT TO STICK AROUND FOR THE BETTER PART OF THE MORNING TO MIDDAY
HOURS...BEFORE MIXING/SCATTERING THROUGH MVFR BETWEEN 14-16Z...AND
TO VFR THEREAFTER.
ATTENTION WILL THEN TURN TO A SHARPENING UPPER LEVEL TROUGH TO OUR
WEST...AND AN ACCOMPANYING ARCTIC COLD FRONT THAT WILL CROSS CENTRAL
NC THIS EVENING AND TONIGHT. SCATTERED RAIN SHOWERS WILL BE POSSIBLE
IN THE VICINITY OF THE FRONT LATE THIS AFTERNOON AT TRIAD TERMINALS
AND THIS EVENING ELSEWHERE...FOLLOWED BY A LARGER BAND OF LIGHT
PRECIPITATION THAT WILL OVERSPREADS OUR REGION OVERNIGHT. WITH COLD
AIR RUSHING IN BEHIND THE ARCTIC FRONT...THAT BAND OF LIGHT
PRECIPITATION WILL FALL AS LIGHT SNOW...AFTER INITIALLY A RAIN/SNOW
MIX AT THE ONSET. MVFR CEILINGS AND MVFR-IFR VISIBILITY RESTRICTIONS
WILL ACCOMPANY THE LIGHT SNOW BAND. IN ADDITION...NORTHWEST WINDS
WILL INCREASE INTO THE 12-15 KT RANGE WITH GUSTS OF 20-25 KTS AS THE
DENSE COLD AIR RUSHES IN BEHIND THE FRONT.
OUTLOOK: SUB-VFR CONDITIONS AT LIGHT SNOW WILL END FROM WEST TO EAST
BETWEEN 09-15Z THU...FOLLOWED BY CLEAR VFR CONDITIONS FOR THE REST
OF THU. ANOTHER FRONTAL SYSTEM WILL BRING A CHANCE OF RAIN CHANGING
TO SNOW...AND ASSOCIATED SUB-VFR CONDITIONS...LATE FRI-FRI NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...CBL/DJF
SHORT TERM...BLAES
LONG TERM...BLAES
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1135 PM CST TUE JAN 14 2014
.UPDATE...
ISSUED AT 1130 PM CST TUE JAN 14 2014
NO UPDATE NEEDED THIS FORECAST PERIOD.
UPDATE ISSUED AT 930 PM CST TUE JAN 14 2014
CLOUD TRENDS AND TEMPERATURES WILL CONTINUE TO BE A CHALLENGE
TONIGHT. N-S ORIENTED CLOUD BAND CONTINUES TO SHIFT SLOWLY EAST
WITH CLEARING APPROACHING THE RED RIVER PROPER. ABOVE CLOUD BAND
HAS HELD TEMPERATURES UP AND WITH SLOW MOVEMENT ADJUSTED
TEMPERATURES UP ACROSS W MN. FARTHER WEST ADVANCING CLOUDS/WARM
ADVECTION SHOULD LEVEL OFF TEMPERATURES. THIS WILL LEAVE COLDEST
TEMPERATURES TONIGHT ACROSS NORTHERN AREAS. MINOR TEMPERATURE AND
CLOUD TREND ADJUSTMENTS MAIN CHANGES THIS UPDATE.
UPDATE ISSUED AT 620 PM CST TUE JAN 14 2014
EASTWARD PROPAGATION OF CLOUD BAND OVER THE VALLEY HAS SLOWED UP
ALLOWING TEMPERATURES TO HOLD UP EARLY THIS EVENING. WILL LEAVE
MINIMUMS AS IS AT THIS POINT BUT WILL NEED TO MONITOR CLEARING
TRENDS. ONLY CHANGES WERE TO ADJUST CLOUD TRENDS AND EVENING
TEMPERATURE CURVE.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 318 PM CST TUE JAN 14 2014
SKY COVER AND TEMPS THE ISSUE TONIGHT. BAND OF STRATOCU CU OVER
ERN ND ATTM AND HOW/WHEN THIS CLEARS OUT WILL BE THE ISSUE FOR LOW
TEMPS. HRRR AND OTHER SHORT TERM MODELS DO BRING CLEARING TO ERN
ND/RRV THIS EVE AND SPREADS IT EAST. WINDS WILL DIMINISH TOO AND
WITH LIKELY CLEARING/CLEAR SKY FOR A WHILE TEMPS WILL DROP QUICKLY
INTO THE 5 TO 10 BELOW ZERO RANGE MOST AREAS WITH A FEW TEEN BELOW
ZERO TEMPS LIKELY IN PARTS OF FAR NW MN. CLOUDS FROM NEXT SYSTEM
WILL SPREAD INTO WRN FCST AREA AFTER MIDNIGHT AS WINDS TURN SOUTH
AND TEMPS WARM...SO PERIOD OF COLD TEMPS IS SMALL.
STRONG 925-850 MB WARM ADVECTION WILL SPREAD WEST TO EAST OVER THE
AREA WEDNESDAY...WITH BAND OF LIGHT SNOW WITH IT ENDING AS SOME
SLEET/FREEZING RAIN AT THE TAIL END. BUT MODELS DO APPEAR TO BUT
MOST OF THE MOISTURE IN THE COLD AIR TO THE EAST OF THE WARM FRONT
SO THINK ICING WILL BE MINIMAL. THUS NO ADVISORIES ISSUED. BUT
LATER SHIFTS CAN MONITOR.
TEMPS WILL WARM SIGNIFICANTLY WED AFTN OVER ERN ND WITH TEMPS 32F
OR HIGHER AS 925 MB REACH +2C. IT WILL BE TURN WINDY AS WELL ESP
WEST OF THE VALLEY WHERE 45-50 KT 925 MB WINDS WILL BE PRESENT.
HOWEVER WITH WARMER AIR COMING OVER THE COLDER SURFACE AN
INVERSION WILL BE PRESENT AND THUS MIXING WILL BE LIMITED. THUS
DONT ANTICIPATE ANY HEADLINES FOR WIND/BLSN WED AFTN/EVE.
VERY CLOSE THOUGH WED EVE AND WILL NEED TO WATCH WIND POTENTIAL.
ARCTIC FRONT WILL START DROPPING SOUTH INTO THE FAR NRN VALLEY
06Z-09Z AND THEN PLUNGE SOUTH REACHING FAR SRN FCST AREA SOON
AFTER 12Z THU. 925 MB WINDS OF 50 KTS BECOME MORE NORTH-SOUTH AND
WITH STRONG SURFACE COOLING SOUNDINGS SHOW ADIABATIC CONDITIONS UP
TO AROUND 870 MB. THUS EXPECT THE FRONT TO ARRIVE WITH A STRONG
PUNCH ALONG WITH SOME SNOW SHOWERS. THUS EXPECT A QUICK DOWNTURN
INTO BLIZZARD CONDITIONS JUST AHEAD AND BEHIND FRONT THRU THE LATE
NIGHT WED NIGHT. DID NOT INCLUDE THE FAR EAST (TREES) IN BLIZZARD WATCH.
WHILE SNOWFALL WILL END IN ERN ND/RRV WED NIGHT DO LOOK FOR SOME
LIGHT SNOW TO LINGER OVER LAKE OF THE WOODS REGION..WHERE TOTAL
NEW SNOWFALL OF 1-3 INCHES IS POSSIBLE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 318 PM CST TUE JAN 14 2014
THURSDAY SHOULD SEE BLIZZARD CONDITIONS OVER THE PRAIRIE
REGION....ERN ND/RRV (ROX-FFM WESTWARD). STRONG COLD ADVECTION
STRONG LAPSE RATES WITH GOOD MIXING OF 50 KT 925 MB WINDS TO THE
SFC SHOULD ENSURE BLOWING SNOW AND NEAR ZERO VISIBILITY AT
TIMES...ESP OUT OF TOWN. ANY FALLING SNOWFALL WILL ADD TO THE VSBY
ISSUES. IT WILL BE A FAST MOVING BLIZZARD IN THAT CONDITIONS WILL
IMPROVE LATE IN THE DAY IN THE NORTH AND IN THE EARLY EVENING IN
THE SOUTH.
CONDITIONS MUCH IMPROVED BY 12Z FRI AS SFC HIGH AND CLEARING MOVE
IN WITH LIGHTER WINDS. NEXT WEAK SHORTWAVE WILL MOVE INTO ERN ND
FRI AFTN WITH SOME LIGHT SNOW/FLURRIES.
FOR THE FRIDAY NIGHT TO TUESDAY TIME FRAME THE FA REMAINS IN
NORTHWEST FLOW ALOFT. ONE WEAK SFC LOW PASSES THROUGH THE AREA FRI
NIGHT SO LEFT SOME LIGHT SNOW CHANCES WITH IT. ANOTHER WEAK WAVE AND
ASSOCIATED SFC LOW PASS NORTH OF THE FA SUN NIGHT WHICH COULD RESULT
IN SOME LIGHT SNOW AGAIN MON AND MON NIGHT. NEITHER SYSTEM AT THIS
POINT LOOKS VERY IMPRESSIVE FOR PRODUCING MUCH SNOW. THE UP AND DOWN
TEMP PATTERN LOOKS TO CONTINUE WITH WARMER AIR MOVING BACK IN
ESPECIALLY BY THE WEEKEND FOLLOWED BY COOLER TEMPS FOR EARLY NEXT
WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1130 PM CST TUE JAN 14 2014
EASTWARD PUSH OF CLOUDS PICKING UP WITH MVFR CIGS CONFINED TO
SOUTHERN VALLEY INTO THE EASTERN FA. EXPECT CLEARING TO CONTINUE
WITH VFR CONDITIONS EXPECTED BY 09Z OR SO. MORE CLOUDS ADVANCING
FROM WEST BUT SHOULD REMAIN VFR UNTIL MID MORNING WITH SNOW BAND
MOVES IN. WINDS WILL INCREASE FROM THE S IN THE AM SWITCHING TO
THE WEST FROM WEST TO EAST DURING THE AFTERNOON.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...BLIZZARD WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
EVENING FOR NDZ038-039-049-052-053.
BLIZZARD WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
AFTERNOON FOR NDZ006>008-014>016-024-026>030-054.
MN...BLIZZARD WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
EVENING FOR MNZ002-003-022-027-029-030-040.
BLIZZARD WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
AFTERNOON FOR MNZ001-004-005-007-008-013>015.
&&
$$
UPDATE...VOELKER
SHORT TERM...RIDDLE
LONG TERM...GODON/RIDDLE
AVIATION...VOELKER
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1159 PM CST TUE JAN 14 2014
.UPDATE...FOR 06Z AVIATION DISCUSSION.
&&
.AVIATION...06Z AVIATION DISCUSSION.
COLD FRONTAL HAS PASSED CSV AS OF 05Z...WITH SOME REPORTS OF LIGHT SNOWFALL
ACROSS NRN PORTIONS OF PLATEAU. PER OVERALL CONTINUED LIMITED LOW LEVEL
MOISTURE LEVEL BEHIND FRONTAL PASSAGE...MVFR CEILINGS CSV SHOULD IMPROVE
TO VFR QUICKLY...WITH A RAIN/SNOW MIX TRANSITIONING TO ALL -SN BY 15/08Z.
-SHSN WILL PERSIST ACROSS PLATEAU THRU 16/01Z AND DEVELOP ACROSS CKV/BNA
BY AROUND 15/13Z PER LIFT AND MOISTURE ASSOCIATED WITH UPPER LEVEL TROUGH
MOVEMENT/PASSAGE ACROSS AREA...BUT AGAIN...OVERALL MINIMAL IMPACTS TO VSBY
EXPECTED AND THUS CONTINUED WITH P6SM REFERENCES. VFR CEILINGS EXPECTED
THRU 16/00Z ALSO. WITH UPPER LEVEL TROUGH PASSAGE AND DRY NWLY FLOW ALOFT
WILL LEAD TO CEILING EROSIONS GENERALLY AFTER 16/01Z.
&&
.PREV DISCUSSION.../ISSUED 1017 PM CST TUE JAN 14 2014/
UPDATE...
JUST MADE SOME GRID ADJUSTMENTS AND LOWERED POPS ACROSS THE WEST.
THE BACK EDGE OF THE SHOWER BAND NOW EXTENDS FROM LAFAYETTE SW TO
WAYNESBORO. HRRR IN AGREEMENT WITH VERY LITTLE IF ANY REDEVELOPMENT
TO THE WEST OF THE BAND BETWEEN NOW AND 12Z.
LOOKING IN PARTICULAR AT THE PLATEAU ADVISORY AREA...LATEST
SOUNDING DATA SUGGESTS THAT SNOW LEVELS WILL BE AROUND 2100 FT MSL
AT 06Z. THIS WOULD SUPPORT SNOW ONLY FOR THE FAR EASTERN REACHES
OF CUMBERLAND COUNTY. BY 08Z OR 09Z...THE VERTICAL COLUMN WILL BE
COLD ENOUGH TO SUPPORT SNOW BUT THE BULK OF THE PRECIP WILL BE
EAST OF THE AREA. I HAVE THEREFORE REDUCED POPS SLIGHTLY. THERE IS
STILL A WEAK UPSLOPE COMPONENT AND AN UPPER LEVEL DYNAMICAL ENERGY
INCREASE EXPECTED BY OR SHORTLY AFTER 12Z. THEREFORE...CONSIDERING
ISC GUIDANCE AS WELL...WILL OPT TO KEEP THE ADVISORY GOING BUT THE
THREAT OF SNOW LOOKS A LITTLE BETTER AFTER 12Z.
PREV DISCUSSION... /ISSUED 629 PM CST TUE JAN 14 2014/
UPDATE...
FRONTAL BOUNDARY LOOKS TO BE LOCATED JUST ALONG THE LEADING EDGE
OF THE RAIN SHOWER ACTIVITY. THIS LEADING EDGE STRETCHES FROM JUST
SOUTHEAST OF CKV SW THROUGH DECATUR COUNTY. TEMPERATURES QUICKLY
DROP DOWN INTO THE 40S BEHIND THE FRONT. THE RAINFALL BAND IS
RATHER NARROW AND THE AIR SUFFICIENTLY COLD ENOUGH TO SUPPORT ANY
SNOWFALL IS WAY UP IN IL AND MO. THUS...THE COLD AIR TO SUPPORT
ANY SNOWFALL WILL NOT ARRIVE PRIMARILY DUE TO ADVECTION.
DYNAMICAL COOLING IS ALSO EXPECTED AS TROUGHING IN THE UPPER
ATMOSPHERE WILL INTENSIFY THROUGH THE NEXT 24 HOURS. IN FACT...BY
THE TIME THIS NARROW AREA OF SHOWERS REACHES THE PLATEAU...AROUND
MIDNIGHT...850 MB TEMPS FOR THE PLATEAU WILL BE BELOW 0C. THUS...A
TRANSITION TO A RAIN AND SNOW MIX IS STILL POSSIBLE FOR THE
PLATEAU AS WE GET CLOSER TO MIDNIGHT.
ONCE THE AFOREMENTIONED BAND PASSES EAST OF THE MID STATE...UPPER
DYNAMICS COULD POTENTIALLY COME INTO PLAY AS PVA MERGES WITH LOW
LEVEL MOISTURE AND SOME WESTERLY UPSLOPE COMPONENT. AFTER THIS
INITIAL RAIN BAND MOVES THROUGH...MODELS ARE RATHER STINGY WITH
THE MOISTURE RETURN. IT DOES HOWEVER LOOK LIKE OCCASIONAL FLURRIES
FOR MUCH OF THE MID STATE. ACROSS THE PLATEAU THOUGH...STILL
CANNOT RULE OUT SOME ACCUMULATING SNOWFALL WITH TOTAL AMOUNTS OF
AROUND AN INCH BEING POSSIBLE.
FOR THE FORECAST UPDATE...ONLY CHANGE WILL BE TO INCREASE POPS
SLIGHTLY ACROSS WESTERN AND CENTRAL AREAS FOR THE CURRENT RAIN
BAND MOVING ACROSS THE AREA THIS EVENING. OTW...I SEE NO REASON TO
MODIFY ANY OF THE OTHER GRIDDED DATA AS OF YET. I WILL BE MAKING
CURRENT HOUR TEMP ADJUSTMENT TO REMAIN IN LINE WITH THE CURRENT
OBS. OTW...NO OTHER CHANGES FOR NOW.
PREV DISCUSSION... /ISSUED 608 PM CST TUE JAN 14 2014/
UPDATE...FOR 00Z AVIATION DISCUSSION.
AVIATION...00Z AVIATION DISCUSSION.
LOOKS LIKE COLD FRONTAL PASSAGE IN PROGRESS AT CKV...AROUND 01Z BNA...AND
AS SOON AS 03Z CSV. OVERALL LOW LEVEL LIMITED MOISTURE STILL EXPECTED...AND
MAYBE AN EXCURSION INTO MVFR CEILINGS MAINLY BEFORE 05/06Z...BUT VFR CEILINGS
SHOULD GENERALLY PREVAIL THROUGHOUT. LOW LEVEL TEMPS APPROACHING FREEZING
NOT EXPECTED UNTIL MAINLY AFTER 05/06Z ALSO...AND PER LIMITED MOISTURE...-SN
ANTICIPATED ACROSS MUCH OF MID STATE PER CAA SCENARIO AND CONTINUED PER COLD
CORE UPPER LEVEL TROUGH PASSAGE EXPECTED ACROSS MID STATE GENERALLY BY 05/24Z
ALSO. GREATEST POTENTIAL FOR VSBY RESTRICTIONS CSV BUT MVFR VSBY RESTRICTIONS
AT BEST. SOME GUSTY NWLY SFC WINDS UP TO 20KTS PER INITIAL CAA SCENARIO ACROSS
AREA...BUT SHOULD DISSIPATE INTO THE 5-10KT RANGE APPROACHING 05/24Z.
PREV DISCUSSION.../ISSUED 237 PM CST TUE JAN 14 2014/
DISCUSSION...
STRONG COLD FRONT NOTED ON RADAR AND SATELLITE IMAGERY THIS
AFTERNOON STRETCHES FROM FSM TO PAH TO IND. LACK OF MOISTURE
RETURN AHEAD OF THE BOUNDARY IS LIMITING PRECIP ALONG THE
FRONT...WHICH COMPLICATES FURTHER THE ALREADY COMPLICATED SNOW
FORECAST FOR TONIGHT AND TOMORROW. 12Z MODEL RUNS INDICATE LIGHT
RAIN WILL INCREASE IN COVERAGE SOMEWHAT AS FRONT MOVES ACROSS THE
AREA THIS EVENING. AFTER MIDNIGHT...NAM/GFS/SREF BUFKIT SOUNDINGS
INDICATE A FEW HOUR WINDOW OF RAIN CHANGING TO SNOW ON THE PLATEAU
AS COLDER AIR FILTERS IN BEHIND THE BOUNDARY...WITH UP TO ONE
HALF INCH OF SNOW POSSIBLE. DOES NOT APPEAR TO BE MUCH IF ANY
OPPORTUNITY FOR A CHANGEOVER ACROSS THE REST OF THE CWA WITH THIS
INITIAL PRECIP TONIGHT AS PRECIP WILL LIKELY OUTRACE THE CAA. A
BETTER CHANCE FOR SNOW APPEARS TO EXIST DURING THE DAY ON
WEDNESDAY AREAWIDE AS UPPER TROUGH MOVES ACROSS MIDDLE
TENNESSEE...WITH VERY COLD TEMPERATURES ALOFT DOWN AS LOW AS -13C
AT 850MB AND -34C AT 500 MB. THIS SETUP WILL CREATE UNUSUALLY
UNSTABLE LOW LEVELS BY LATE MORNING AND AFTERNOON DESPITE SURFACE
TEMPERATURES ONLY IN THE 20S AND 30S ACROSS THE CWA. THUS
WIDELY SCATTERED CONVECTIVE SNOW SHOWERS/BANDS ARE EXPECTED TO
FORM THROUGHOUT THE FORECAST AREA...WITH 12Z 4KM WRF ACTUALLY
INDICATING FAIRLY WIDESPREAD COVERAGE OF SNOW SHOWERS. AS THESE
SHOWERS ARE FORCED UP THE HIGHER TERRAIN OF THE
PLATEAU...ANTICIPATING ADDITIONAL SNOW ACCUMS THERE AROUND ONE
HALF INCH OR SO FOR TOTAL AMOUNTS GENERALLY AROUND 1
INCH...POSSIBLY MORE. A DUSTING IS NOT OUT OF THE QUESTION IN
OTHER PARTS OF THE CWA WHERE SNOW SHOWERS PERSIST.
BASED ON THIS REASONING...HAVE KEPT WINTER WEATHER ADVISORY
INTACT FOR EASTERN ZONES BUT TRIMMED IT BACK TO JUST THE PLATEAU
COUNTIES WHERE 1 INCH TOTAL ACCUMS ARE MORE LIKELY. ALSO EXTENDED
THE ADVISORY IN TIME TO 16/00Z BASED ON THE EXPECTED DIURNAL
CONVECTIVE SNOW SHOWERS. WHERE SNOW ACCUMULATES...SOME ROAD
IMPACTS ARE POSSIBLE EVEN INTO THURSDAY MORNING AS TEMPERATURES
DROP INTO THE TEENS AND 20S. THANKS TO MRX...LMK...AND JKL FOR
COORDINATION ON THIS.
A VERY ACTIVE WEATHER PATTERN IS IN STORE FOR THE MID STATE OVER
THE NEXT WEEK AS A PARADE OF CLIPPER-TYPE SYSTEMS MOVES ACROSS IN
A NEAR DAILY FASHION. A BRIEF WARMUP WILL OCCUR THURSDAY BEFORE
THE NEXT ROUND OF POTENTIAL RAIN AND SNOW SHOWERS SWEEPS THROUGH
THURSDAY NIGHT AND FRIDAY. MORE MOISTURE APPEARS TO BE AVAILABLE
WITH THIS SYSTEM AND THUS BETTER CHANCES FOR MORE WIDESPREAD
ALTHOUGH STILL LIGHT SNOW ACCUMS. GFS/ECMWF BEGIN TO DIVERGE
SOMEWHAT IN THE HANDLING OF SYSTEMS FROM SATURDAY ONWARD WITH GFS
MORE AGGRESSIVE WITH QPF...SO HAVE SPLIT THE DIFFERENCE WITH LOW
POPS SATURDAY/SATURDAY NIGHT AND MONDAY NIGHT/TUESDAY.
TEMPERATURES WILL BE ON A ROLLER COASTER RIDE OF BRIEF WARM UPS WITH
SIGNIFICANT COOL DOWNS...AND KEPT TEMPS GENERALLY CLOSE TO MAV/MEX
GUIDANCE.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM CST WEDNESDAY FOR TNZ011-
032>034-065-066-078>080.
&&
$$
31
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1017 PM CST TUE JAN 14 2014
.UPDATE...
JUST MADE SOME GRID ADJUSTMENTS AND LOWERED POPS ACROSS THE WEST.
THE BACK EDGE OF THE SHOWER BAND NOW EXTENDS FROM LAFAYETTE SW TO
WAYNESBORO. HRRR IN AGREEMENT WITH VERY LITTLE IF ANY REDEVELOPMENT
TO THE WEST OF THE BAND BETWEEN NOW AND 12Z.
LOOKING IN PARTICULAR AT THE PLATEAU ADVISORY AREA...LATEST
SOUNDING DATA SUGGESTS THAT SNOW LEVELS WILL BE AROUND 2100 FT MSL
AT 06Z. THIS WOULD SUPPORT SNOW ONLY FOR THE FAR EASTERN REACHES
OF CUMBERLAND COUNTY. BY 08Z OR 09Z...THE VERTICAL COLUMN WILL BE
COLD ENOUGH TO SUPPORT SNOW BUT THE BULK OF THE PRECIP WILL BE
EAST OF THE AREA. I HAVE THEREFORE REDUCED POPS SLIGHTLY. THERE IS
STILL A WEAK UPSLOPE COMPONENT AND AN UPPER LEVEL DYNAMICAL ENERGY
INCREASE EXPECTED BY OR SHORTLY AFTER 12Z. THEREFORE...CONSIDERING
ISC GUIDANCE AS WELL...WILL OPT TO KEEP THE ADVISORY GOING BUT THE
THREAT OF SNOW LOOKS A LITTLE BETTER AFTER 12Z.
&&
.PREV DISCUSSION... /ISSUED 629 PM CST TUE JAN 14 2014/
UPDATE...
FRONTAL BOUNDARY LOOKS TO BE LOCATED JUST ALONG THE LEADING EDGE
OF THE RAIN SHOWER ACTIVITY. THIS LEADING EDGE STRETCHES FROM JUST
SOUTHEAST OF CKV SW THROUGH DECATUR COUNTY. TEMPERATURES QUICKLY
DROP DOWN INTO THE 40S BEHIND THE FRONT. THE RAINFALL BAND IS
RATHER NARROW AND THE AIR SUFFICIENTLY COLD ENOUGH TO SUPPORT ANY
SNOWFALL IS WAY UP IN IL AND MO. THUS...THE COLD AIR TO SUPPORT
ANY SNOWFALL WILL NOT ARRIVE PRIMARILY DUE TO ADVECTION.
DYNAMICAL COOLING IS ALSO EXPECTED AS TROUGHING IN THE UPPER
ATMOSPHERE WILL INTENSIFY THROUGH THE NEXT 24 HOURS. IN FACT...BY
THE TIME THIS NARROW AREA OF SHOWERS REACHES THE PLATEAU...AROUND
MIDNIGHT...850 MB TEMPS FOR THE PLATEAU WILL BE BELOW 0C. THUS...A
TRANSITION TO A RAIN AND SNOW MIX IS STILL POSSIBLE FOR THE
PLATEAU AS WE GET CLOSER TO MIDNIGHT.
ONCE THE AFOREMENTIONED BAND PASSES EAST OF THE MID STATE...UPPER
DYNAMICS COULD POTENTIALLY COME INTO PLAY AS PVA MERGES WITH LOW
LEVEL MOISTURE AND SOME WESTERLY UPSLOPE COMPONENT. AFTER THIS
INITIAL RAIN BAND MOVES THROUGH...MODELS ARE RATHER STINGY WITH
THE MOISTURE RETURN. IT DOES HOWEVER LOOK LIKE OCCASIONAL FLURRIES
FOR MUCH OF THE MID STATE. ACROSS THE PLATEAU THOUGH...STILL
CANNOT RULE OUT SOME ACCUMULATING SNOWFALL WITH TOTAL AMOUNTS OF
AROUND AN INCH BEING POSSIBLE.
FOR THE FORECAST UPDATE...ONLY CHANGE WILL BE TO INCREASE POPS
SLIGHTLY ACROSS WESTERN AND CENTRAL AREAS FOR THE CURRENT RAIN
BAND MOVING ACROSS THE AREA THIS EVENING. OTW...I SEE NO REASON TO
MODIFY ANY OF THE OTHER GRIDDED DATA AS OF YET. I WILL BE MAKING
CURRENT HOUR TEMP ADJUSTMENT TO REMAIN IN LINE WITH THE CURRENT
OBS. OTW...NO OTHER CHANGES FOR NOW.
PREV DISCUSSION... /ISSUED 608 PM CST TUE JAN 14 2014/
UPDATE...FOR 00Z AVIATION DISCUSSION.
AVIATION...00Z AVIATION DISCUSSION.
LOOKS LIKE COLD FRONTAL PASSAGE IN PROGRESS AT CKV...AROUND 01Z BNA...AND
AS SOON AS 03Z CSV. OVERALL LOW LEVEL LIMITED MOISTURE STILL EXPECTED...AND
MAYBE AN EXCURSION INTO MVFR CEILINGS MAINLY BEFORE 05/06Z...BUT VFR CEILINGS
SHOULD GENERALLY PREVAIL THROUGHOUT. LOW LEVEL TEMPS APPROACHING FREEZING
NOT EXPECTED UNTIL MAINLY AFTER 05/06Z ALSO...AND PER LIMITED MOISTURE...-SN
ANTICIPATED ACROSS MUCH OF MID STATE PER CAA SCENARIO AND CONTINUED PER COLD
CORE UPPER LEVEL TROUGH PASSAGE EXPECTED ACROSS MID STATE GENERALLY BY 05/24Z
ALSO. GREATEST POTENTIAL FOR VSBY RESTRICTIONS CSV BUT MVFR VSBY RESTRICTIONS
AT BEST. SOME GUSTY NWLY SFC WINDS UP TO 20KTS PER INITIAL CAA SCENARIO ACROSS
AREA...BUT SHOULD DISSIPATE INTO THE 5-10KT RANGE APPROACHING 05/24Z.
PREV DISCUSSION.../ISSUED 237 PM CST TUE JAN 14 2014/
DISCUSSION...
STRONG COLD FRONT NOTED ON RADAR AND SATELLITE IMAGERY THIS
AFTERNOON STRETCHES FROM FSM TO PAH TO IND. LACK OF MOISTURE
RETURN AHEAD OF THE BOUNDARY IS LIMITING PRECIP ALONG THE
FRONT...WHICH COMPLICATES FURTHER THE ALREADY COMPLICATED SNOW
FORECAST FOR TONIGHT AND TOMORROW. 12Z MODEL RUNS INDICATE LIGHT
RAIN WILL INCREASE IN COVERAGE SOMEWHAT AS FRONT MOVES ACROSS THE
AREA THIS EVENING. AFTER MIDNIGHT...NAM/GFS/SREF BUFKIT SOUNDINGS
INDICATE A FEW HOUR WINDOW OF RAIN CHANGING TO SNOW ON THE PLATEAU
AS COLDER AIR FILTERS IN BEHIND THE BOUNDARY...WITH UP TO ONE
HALF INCH OF SNOW POSSIBLE. DOES NOT APPEAR TO BE MUCH IF ANY
OPPORTUNITY FOR A CHANGEOVER ACROSS THE REST OF THE CWA WITH THIS
INITIAL PRECIP TONIGHT AS PRECIP WILL LIKELY OUTRACE THE CAA. A
BETTER CHANCE FOR SNOW APPEARS TO EXIST DURING THE DAY ON
WEDNESDAY AREAWIDE AS UPPER TROUGH MOVES ACROSS MIDDLE
TENNESSEE...WITH VERY COLD TEMPERATURES ALOFT DOWN AS LOW AS -13C
AT 850MB AND -34C AT 500 MB. THIS SETUP WILL CREATE UNUSUALLY
UNSTABLE LOW LEVELS BY LATE MORNING AND AFTERNOON DESPITE SURFACE
TEMPERATURES ONLY IN THE 20S AND 30S ACROSS THE CWA. THUS
WIDELY SCATTERED CONVECTIVE SNOW SHOWERS/BANDS ARE EXPECTED TO
FORM THROUGHOUT THE FORECAST AREA...WITH 12Z 4KM WRF ACTUALLY
INDICATING FAIRLY WIDESPREAD COVERAGE OF SNOW SHOWERS. AS THESE
SHOWERS ARE FORCED UP THE HIGHER TERRAIN OF THE
PLATEAU...ANTICIPATING ADDITIONAL SNOW ACCUMS THERE AROUND ONE
HALF INCH OR SO FOR TOTAL AMOUNTS GENERALLY AROUND 1
INCH...POSSIBLY MORE. A DUSTING IS NOT OUT OF THE QUESTION IN
OTHER PARTS OF THE CWA WHERE SNOW SHOWERS PERSIST.
BASED ON THIS REASONING...HAVE KEPT WINTER WEATHER ADVISORY
INTACT FOR EASTERN ZONES BUT TRIMMED IT BACK TO JUST THE PLATEAU
COUNTIES WHERE 1 INCH TOTAL ACCUMS ARE MORE LIKELY. ALSO EXTENDED
THE ADVISORY IN TIME TO 16/00Z BASED ON THE EXPECTED DIURNAL
CONVECTIVE SNOW SHOWERS. WHERE SNOW ACCUMULATES...SOME ROAD
IMPACTS ARE POSSIBLE EVEN INTO THURSDAY MORNING AS TEMPERATURES
DROP INTO THE TEENS AND 20S. THANKS TO MRX...LMK...AND JKL FOR
COORDINATION ON THIS.
A VERY ACTIVE WEATHER PATTERN IS IN STORE FOR THE MID STATE OVER
THE NEXT WEEK AS A PARADE OF CLIPPER-TYPE SYSTEMS MOVES ACROSS IN
A NEAR DAILY FASHION. A BRIEF WARMUP WILL OCCUR THURSDAY BEFORE
THE NEXT ROUND OF POTENTIAL RAIN AND SNOW SHOWERS SWEEPS THROUGH
THURSDAY NIGHT AND FRIDAY. MORE MOISTURE APPEARS TO BE AVAILABLE
WITH THIS SYSTEM AND THUS BETTER CHANCES FOR MORE WIDESPREAD
ALTHOUGH STILL LIGHT SNOW ACCUMS. GFS/ECMWF BEGIN TO DIVERGE
SOMEWHAT IN THE HANDLING OF SYSTEMS FROM SATURDAY ONWARD WITH GFS
MORE AGGRESSIVE WITH QPF...SO HAVE SPLIT THE DIFFERENCE WITH LOW
POPS SATURDAY/SATURDAY NIGHT AND MONDAY NIGHT/TUESDAY.
TEMPERATURES WILL BE ON A ROLLER COASTER RIDE OF BRIEF WARM UPS WITH
SIGNIFICANT COOL DOWNS...AND KEPT TEMPS GENERALLY CLOSE TO MAV/MEX
GUIDANCE.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM CST WEDNESDAY FOR TNZ011-
032>034-065-066-078>080.
&&
$$
21
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1046 PM CST TUE JAN 14 2014
.DISCUSSION...SEE 06Z AVIATION DISCUSSION.
&&
.AVIATION...GUSTY NORTH WINDS TONIGHT WILL DIE DOWN BY 15Z ALL BUT
KCRP WHERE WINDS MAY STAY UP A BIT LONGER (AS USUAL). WINDS BECOME
LIGHT AND MAINLY SOUTHERLY AROUND SUNSET (DIE DOWN FIRST...THEN
BECOME SOUTHERLY AFTER 16/00Z.
&&
.PREV DISCUSSION... /ISSUED 912 PM CST TUE JAN 14 2014/
DISCUSSION...BASED ON RADAR...COLD FRONTAL BDRY IS PUSHING THROUGH
THE CWA AND SHOULD REACH CORPUS AROUND 04Z. HAVE MADE SOME TWEAKS
TO THE DEWPOINTS AND WINDS BASED ON CURRENT TRENDS BEHIND THE
FRONTAL BDRY. THESE TWEAKS INCLUDED LOWERING DEWPOINTS ACROSS THE
W CWA BY A FEW DEGREES BASED ON MSAS ANALYSIS WITH DEWPOINTS
COMING BACK UP BY A FEW DEGREES OVERNIGHT. ALSO INCREASED WIND
SPEEDS BY A COUPLE OF KNOTS. TIMING OF SMALL CRAFT ADVISORY LOOKS
GOOD BUT HAVE INCLUDED NRN BAYS IN THE ADVISORY AS WELL. UPDATES
WILL BE OUT SHORTLY.
PREV DISCUSSION... /ISSUED 531 PM CST TUE JAN 14 2014/
DISCUSSION...SEE 00Z AVIATION DISCUSSION.
AVIATION...MAIN ISSUE IS TIMING OF FRONT...THEN HOW LONG WINDS
STAY UP BEFORE DIMINISHING (AND KEEPING EVERYTHING RELATIVELY
SHORT SINCE NO OTHER SIGNIFICANT WEATHER). USING HRRR AND TTU 4 KM
MODELS...AM GOING WITH WIND SHIFT ABT 03Z AT KVCT...ABT 04Z AT
KRLD AND 05Z AT KCRP/KALI (GIVE OR TAKE 30 MINUTES). AM GOING TO
KEEP WINDS UP TIL AT LEAST 12Z...THEN DIMINISH FROM WEST TO EAST
DURING THE DAY ON THE 15TH. WITH WINDS UP FOR THE EVENING AND
OVERNIGHT PERIOD...WIND SHEAR SHOULD BE NO PROBLEM.
OTHERWISE...SKC.
PREV DISCUSSION... /ISSUED 325 PM CST TUE JAN 14 2014/
SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...COLD FRONT WILL MOVE
THROUGH CWA JUST BEFORE MIDNIGHT TONIGHT...BRINGING NORTHERLY
WINDS AROUND 15 KT OVER LAND AND 25 KT OFFSHORE. WEDNESDAY
AFTERNOON SHOULD SEE A SURFACE HIGH BEHIND THE FRONT SETTLE INTO
THE FORECAST AREA. AS THE CENTER OF HIGH PRESSURE TOMORROW WILL BE
LOCATED OVER THE RIO GRANDE VALLEY...EXPECTING LIGHT WESTERLY
WINDS. BY TOMORROW NIGHT...SURFACE HIGH PRESSURE WILL SHIFT EAST
AND MOVE OVER THE WESTERN GOM WHICH WILL ALLOW ONSHORE FLOW TO
RESUME AND INCREASE LOW LEVEL MOISTURE. THE LACK OF ANY MOISTURE
WILL KEEP POPS TO ZERO AND KEEP SKIES CLEAR THROUGH THE SHORT
TERM. CLEAR SKIES TONIGHT SHOULD ALLOW FOR LOWS IN THE LOWER 40S
OVER THE SOUTHERN BRUSH COUNTRY AND SOUTHERN COASTAL BEND AND THE
UPPER 30S OVER THE NORTHERN COUNTIES. HIGHS TOMORROW BEHIND THE
FRONT WILL BE IN THE 60S ACROSS MOST OF THE AREA WITH SOME UPPER
50S OFFSHORE. COOLER AIR BEHIND THE FRONT AND ANOTHER CLEAR AND
CALM NIGHT WILL LEAD TO LOWS IN THE MID 30S INLAND AND LOWER 40S
NEAR THE COAST...AS WELL AS THE WESTERN BRUSH COUNTRY.
MARINE...INCREASING NORTHERLY WINDS BEHIND TONIGHTS FRONT WILL
INCREASE OFFSHORE WINDS TO 20-25 KT BETWEEN 6 AND 18Z.
ADDITIONALLY...WAVE HEIGHTS AROUND 7 FEET ARE EXPECTED IN THE
OFFSHORE ZONES. A SMALL CRAFT ADVISORY WILL BE IN EFFECT FROM 6 TO
12Z OVER THE SOUTHERN BAYS AND WATERWAYS...AND 6 TO 18Z OVER THE
OFFSHORE WATERS. TOMORROW AFTERNOON WILL SEE A RETURN TO CALMER
CONDITIONS.
LONG TERM (THURSDAY THROUGH TUESDAY)...WEATHER ON THURSDAY EXPECTED
TO BE QUITE NICE WITH A DRY ATMOSPHERIC COLUMN LEADING TO A PLETHORA
OF SUNSHINE DURING THE DAY. ANOTHER COLD FRONT WILL SLIP SOUTH INTO
THE REGION THURSDAY NIGHT BUT LACK OF ANY SUFFICIENT MOISTURE SHOULD
PRECLUDE ANY SIGNIFICANT PRECIP FROM OCCURRING. TIMING DIFFERENCES
EXIST BETWEEN GUIDANCE WITH GFS BEING FASTER AND ECMWF/NAM BEING A
LITTLE SLOWER. OFFICIAL FORECAST PACKAGE HAS FROPA OCCURRING BETWEEN
MIDNIGHT AND SUNRISE WITH A PERIOD OF GUSTY NORTH WINDS POST FROPA.
SURFACE HIGH PRESSURE PROG TO QUICKLY BUILD IN AND THEN MOVE TO THE
EAST DURING THE DAY FRIDAY WITH SOUTHERLY LLVL FLOW RETURNING BY THE
WEEKEND. THIS SHOULD RESULT IN AN INCREASE IN LLVL MOISTURE AND
ASSOCIATED CLOUD COVER...WITH THICKEST CLOUD COVER LOCATED ACROSS
EASTERN HALF OF CWA. WITH MOISTURE PROG TO BE LIMITED TO ONLY THE
LOWER LEVELS...CHANCES OF RAIN WILL REMAIN LOW TO NIL THROUGH THE
WEEKEND. A MORE POTENT COLD FRONT MAY APPROACH THE AREA BY LATE IN
THE EXTENDED FORECAST. FRIDAY WILL LIKELY BE THE COOLEST DAY OF THE
EXTENDED PERIOD WITH HIGHS ONLY IN THE UPPER 60S TO AROUND 70. SSW
LLVL WIND PROFILE OVER THE WEEKEND SHOULD HELP WARM DAYTIME TEMPS
THROUGH THE 70S WITH SOME LOCATIONS TOUCHING 80 AT TIMES. MIN TEMPS
WILL GRADUALLY MODIFY EACH NIGHT FROM THE 30S/40S THURSDAY NIGHT
INTO THE 40S/50S OVER THE WEEKEND/EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 42 64 38 73 45 / 0 0 0 0 10
VICTORIA 37 63 35 70 40 / 0 0 0 0 10
LAREDO 42 64 42 74 45 / 0 0 0 0 0
ALICE 41 65 36 74 43 / 0 0 0 0 10
ROCKPORT 42 61 42 67 45 / 0 0 0 0 10
COTULLA 39 63 36 73 38 / 0 0 0 0 0
KINGSVILLE 41 65 35 75 44 / 0 0 0 0 10
NAVY CORPUS 47 62 44 69 48 / 0 0 0 0 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL NOON CST WEDNESDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT
20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS
FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 6 AM CST WEDNESDAY FOR THE FOLLOWING
ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS...
BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT O`CONNOR.
&&
$$
GW/86...AVIATION
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
402 PM EST WED JAN 15 2014
.SYNOPSIS...
A SERIES OF CLIPPER SYSTEM WILL PROGRESS THROUGH THE REGION OVER
THE NEXT SEVERAL DAYS. ONE WILL CROSS THE AREA TONIGHT...ONE
TOMORROW NIGHT AND FRIDAY...ANOTHER SATURDAY INTO SUNDAY. AFTER A
BRIEF PERIOD OF MORE TRANQUIL WEATHER...ANOTHER SYSTEM MOVES INTO
THE AREA FROM THE NORTHWEST ON WEDNESDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 330 PM EST WEDNESDAY...
WATER VAPOR SATELLITE IMAGERY WAS SHOWING THE AXIS OF THE UPPER
TROUGH SWINGING THROUGH THE LOWER MISSISSIPPI RIVER VALLEY. A JETLET
ON THE EAST SIDE OF THE TROUGH WAS CURRENTLY PASSING ACROSS THE
WESTERN HALF OF THE FORECAST AREA...AND HELPING TO BRIEFLY INTENSIFY
THE STRENGTH OF THE PRECIPITATION ACROSS THE SOUTHWEST PARTS OF THE
REGION. THE FOCUS FOR THE INCREASED ACTIVITY WILL TREND NORTHEAST
ACROSS THE AREA IN RELATION TO TRACK OF THE JETLET...AND THE SUBTLE
PUSH EASTWARD OF THE UPPER TROUGH.
THE VAST MAJORITY OF THE SNOWFALL IN THE AREA OF THE WINTER WEATHER
ADVISORIES IS OVER. ADDITIONAL LIGHT AMOUNTS UNDER AN INCH ARE
EXPECTED ACROSS THE NORTHERN MOUNTAINS OF NORTH CAROLINA AND
NEIGHBORING GRAYSON COUNTY VA. HERE A BRIEF AND RELATIVELY WEAK
UPSLOPE COMPONENT WILL HELP MAINTAIN LIGHT SNOWFALL UNTIL THE AXIS
OF THE UPPER TROUGH MOVES OVERHEAD OF THIS AREA AROUND MIDNIGHT
TONIGHT. WILL KEEP THE ADVISORY GOING IN THIS AREA BECAUSE OF
THIS...AND ALLOW SUBSEQUENT SHIFTS TO CANCEL IF NEED BE BASED UPON
THE LATEST SATELLITE AND RADAR TRENDS. HOWEVER...WILL BRING THE END
TIME OF THE TAZEWELL AND SMYTH COUNTY PART OF THE ADVISORY BACK TO
600 PM. THE HEAVIEST SNOW IS EXITING THIS REGION CURRENTLY...AND
THIS REGION WILL NOT BENEFIT FROM ANY UPSLOPE COMPONENT THIS EVENING.
THE REMAINDER OF THE AREA WILL EXPERIENCE EITHER LIGHT RAIN OR LIGHT
SNOW OR A MIX OF THE TWO THROUGH THE EVENING AND EARLY THURSDAY
MORNING AS THE UPPER TROUGH CONTINUES ITS PROGRESS EASTWARD. THE
BEST CHANCE OF ACCUMULATING SNOW WILL BE ACROSS THE HIGHER TERRAIN
FROM ROUGHLY FLOYD VA NORTH TO NEAR LEXINGTON VA. HERE AMOUNTS WILL
APPROACH ONE INCH OF SNOW AT ELEVATIONS AT OR ABOVE ROUGHLY 2000
FEET MSL.
ACROSS THE PIEDMONT...MOST AREAS WILL BE TOO MILD FOR ALL SNOW...BUT
MORE LIKELY EXPERIENCE A MIX OF RAIN AND SNOW OR ALL
RAIN...ESPECIALLY THOSE AREA OVER SOUTHSIDE VIRGINIA AND NEIGHBORING
SECTIONS OF NORTH CENTRAL NORTH CAROLINA. ANY SNOWFALL WILL BE
LIGHT...AND BE FIGHTING WITH THE RAIN TO ACCUMULATE. VERY LATE
TONIGHT/EARLY THURSDAY MORNING...TEMPERATURES ARE EXPECTED TO BE
COLD ENOUGH FOR ALL SNOW ACROSS EVEN THE FAR SOUTHEAST PART OF THE
REGION. HOWEVER...BY THAT TIME...THE VAST MAJORITY OF THE MOISTURE
WILL BE OUT OF THE AREA...ALLOWING FOR TRACE AMOUNTS AT BEST.
LOWS TONIGHT WILL RANGE FROM THE UPPER TEENS TO LOWER 20S IN THE
MOUNTAINS TO THE MID TO UPPER 20S ACROSS THE PIEDMONT.
DURING THE DAY THURSDAY...THE AREA WILL BE BETWEEN SYSTEMS...THE
DEPARTING UPPER TROUGH FROM TODAY...AND THE NEXT CLIPPER SYSTEM
APPROACHING THE AREA OVER THE GREAT LAKES. WHILE WE EXPECT NO
PRECIPITATION...AND MOSTLY CLEAR SKIES EARLY IN THE DAY...THERE WILL
BE A TREND TOWARD INCREASING CLOUDS LATE IN THE DAY IN THE WEST IN
ADVANCE OF THE APPROACHING CLIPPER. HIGHS ON FRIDAY WILL RANGE FROM
THE LOW TO MID 30S ACROSS THE MOUNTAINS TO AROUND 40 TO THE MID 40S
ACROSS THE PIEDMONT.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 330 PM EST WEDNESDAY...
THE NORTHERN STREAM JET WILL REMAIN ACTIVE THROUGH THE UPCOMING
WEEKEND WITH A LONG WAVE FULL LATITUDE UPPER LEVEL TROUGH OVER THE
EASTERN CONUS AND A RIDGE ALONG THE WEST COAST. THIS PATTERN WILL
SUBJECT OUR FORECAST AREA TO A CONTINENTAL POLAR AIRMASS WHICH WILL
RESULT IN A DOWNWARD SPIRAL OF TEMPERATURES ACROSS THE MID
ATLANTIC REGION FOR THE UPCOMING WEEKEND. COLDEST OF THE AIR...M14
TO M16 DEG C...IS FCST TO MOVE OVERHEAD SATURDAY...SURFACE
TEMPERATURES STRUGGLING TO GET ABOVE FREEZING. THE MOUNTAINS WILL
LIKELY REMAIN IN THE 20S ON SATURDAY WITH WIND CHILLS IN THE SINGLE
DIGITS.
PRECIPITATION THREAT THROUGH THE UPCOMING WEEKEND LOOKS TO BE MAINLY
CONFINED TO THE MOUNTAINS. TWO CLIPPERS ARE FORECAST TO PASS ACROSS
THE AREA. THE FIRST WILL MOVE ACROSS THE GREAT LAKES FRIDAY...THE
SECOND SYSTEM TAKING A SIMILAR TRACK SATURDAY NIGHT. THE FIRST
DISTURBANCE WILL BEGIN TO SPREAD CLOUDS OVER THE ARE THURSDAY NIGHT
WITH MOUNTAIN SNOW SHOWERS DEVELOPING AS THE SYSTEM APPROACHES EARLY
FRIDAY. CAN`T RULE OUT SOME LIGHT MIXED PRECIP EAST OF THE
MOUNTAINS FRIDAY...BUT THINK THE ACCUMULATING SNOW WILL REMAIN
PRIMARILY CONFINED TO THE MOUNTAINS WEST OF THE BLUE RIDGE WITH 1-3
INCHES POSSIBLE IN THE HIGH COUNTRY OF NC...THE MTNS OF FAR
SOUTHWESTERN VA...AND THE MOUNTAINS OF SOUTHEAST WEST VIRGINIA. THE
PASSAGE OF THE CLIPPER WILL BRING GUSTY NORTHWEST WINDS AND MUCH
COLDER TEMPERATURES TO THE AREA FRIDAY NIGHT...MOUNTAIN SNOW SHOWERS
AND FLURRIES CONTINUING WEST OF THE BLUE RIDGE. LOWS FRIDAY NIGHT
ARE EXPECTED TO DIP INTO THE LOWER TEENS IN THE MOUNTAINS WITH WIND
CHILLS NEAR ZERO.
THE SECOND DISTURBANCE IS PROGGED TO COME QUICK ON THE HEELS OF
FRIDAY NIGHTS WINTRY BLAST...WITH REPEAT THREAT FOR MOUNTAIN SNOW
SHOWERS SATURDAY NIGHT OFFERING ANOTHER 1 TO 3 INCHES OF
ACCUMULATION IN THE FAVORED HIGHLAND AREAS WHICH ARE PRONE TO THESE
NORTHWEST FLOW SORT OF SYSTEMS. EAST OF THE BLUE RIDGE...SOME LIGHT
PRECIP IS POSSIBLE...BUT THE DOWNSLOPE DRYING OF THE WIND TENDS TO
ELIMINATE MUCH OF A CHANCE FOR SEEING ANYTHING MEASURABLE THERE. IN
ORDER TO GET MEASURABLE PRECIP EAST OF THE BLUE RIDGE...THE SYSTEM
WOULD NEED TO TRACK SOUTH OF THE AREA. ATTM IT LOOKS LIKE THE TRACK
WILL BE TO OUR NORTH...TAKING THE CENTER OF THE DISTURBANCE ACROSS
THE MASON DIXON. THIS SORT OF TRACK WOULD SUGGEST THE HEAVIER
PRECIP THREAT WILL PASS WELL NORTH OF OUR AREA FROM PENNSYLVANIA
INTO NEW ENGLAND.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 PM EST WEDNESDAY...
CLIPPER LOW DARTS ACROSS THE OHIO VALLEY ON SUNDAY...LEAVING A GOOD
BURST OF WIND AND SOME UPSLOPE SNOW SHOWERS ACROSS THE GREENBRIER
VALLEY. STRONG DOWNSLOPE WNW FLOW WILL TAKE THE EDGE OFF THE COLD
AIR AS IT CROSSES INTO THE ROANOKE VALLEY AND PIEDMONT. SOME 40KT
GUSTS MAY BE POSSIBLE ACROSS NW NC INTO SUNDAY MORNING WHEN THE
BOUNDARY CROSSES...AND POSSIBLY INTO WESTERN GREENBRIER AND BATH
COUNTY. WAA AND WINDS REMAINING OVERNIGHT INTO MONDAY MEANS A WELL
MIXED ATMOSPHERE AND MIN TEMPS POTENTIALLY SEVERAL DEGREES WARMER
THAN GUIDANCE ESPECIALLY ALONG THE RIDGE TOPS. TEMPS SHOULD WARM
EVEN MORE ON MONDAY AHEAD OF THE NEXT CLIPPER WITH MANY 50F MAX
TEMPS POSSIBLE...HOWEVER THE GREENBRIER VALLEY WILL BE STUNTED
SOMEWHAT BY LATE ARRIVING CLOUDS. MORE WARM...DRY AND BREEZY DAYS
LIKE THIS AND SOME FIRE WX CONCERNS MAY BEGIN TO MOUNT.
THE 12Z ECMWF IS FASTER AND MORE AGGRESSIVE WITH A LOW DEVELOPING
ALONG THE NEXT ARCTIC FRONT SLATED FOR TUESDAY OR TUESDAY
NIGHT...THAN THE 12Z GFS. THE ECMWF HAS BEEN UNCHARACTERISTICALLY
SUBPAR SINCE ITS LATEST UPDATE...AND A LITTLE HESITANT TO TRUST IT
OVER THE GFS ATTM. NONETHELESS...-20C H85 AIR MAY ARRIVE ACROSS THE
GREENBRIER VALLEY BY NEXT WEDNESDAY BEHIND THE FRONT. UP FOR DEBATE
IS HOW FAR SOUTH THE MAIN WAVE DIVES...WHICH HAS A LOT TO DUE WITH
ANY DEVELOPMENT ALONG THE FRONT. REGARDLESS THERE STILL WILL BE AN
UPSLOPE SNOW EVENT TUESDAY NIGHT INTO WEDNESDAY. IF THE FRONT IS
SLOWER...WHICH IS USUALLY THE CASE THIS DEEP INTO THE
FORECAST...THEN TUESDAY COULD STILL BE ANOTHER WARM DAY FOR ALL
AREAS OUTSIDE OF SE WEST VA. HEART OF THE COLDEST AIR IN PLACE
WEDNESDAY AND WEDNESDAY NIGHT. HIGHS POTENTIALLY IN THE TEENS ON
WEDNESDAY ACROSS SE WEST VA.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
AS OF 1245 PM EST WEDNESDAY...
WILL LEAN ON LOCAL WRF AND HRRR MESO MODEL RUNS FOR TIMING OF
CIGS/WX. BAND OF SNOW ASSOCIATED WITH WEAK FRONT EXTENDING DOWN
FROM CLIPPER IN THE GREAT LAKES HAS BEEN MAKING VERY SLOW PROGRESS
EWD AND EXPECTING IT TO BREAK UP IN DOWNSLOPE EAST OF THE BLUE
RIDGE AND PERHAPS REGAIN SOME VIGOR AS IT INTERACTS WITH
DEVELOPING LOW PRESSURE TO THE EAST LATE. NOT EXPECTING WINDS TO
BE A SIGNIFICANT ISSUE THROUGH THE TAF PERIOD AS THEY BECOME
NWLY/NLY BEHIND THE FRONT...THEN BEGIN TO SLACKEN AND BACK
TOMORROW.
BELIEVE KBLF/KLWB WILL SEE BEST SHOT OF -SHSN EARLY IN THE
PERIOD...BUT WILL STAY WITH UPSLOPE -SHSN AND NO BETTER THAN MVFR
THROUGH THE OVERNIGHT. EXPECT KBCB TO SEE MVFR CIGS WITH SOME
-SHSN THROUGH THE FIRST PART OF THE PERIOD WITH IMPROVEMENT TO VFR
WAITING UNTIL THE SHARP UPPER TROF SWINGS THROUGH LATE TONIGHT.
KROA SHOULD REMAIN VFR WITH A FEW PERIODS OF MVFR THIS EVENING.
LOW CLOUDS/FOG AT KDAN WERE HANGING TOUGH AT ISSUANCE TIME BUT VIS
SAT LOOP WAS SHOWING SIGNIFICANT EROSION OF THE CLOUDS. BELIEVE
THE IFR AT KDAN WILL BE SHORT LIVED AND WILL LEAVE IT OUT OF THE
TAF. KDAN/KLYH WILL STAY VFR EARLY BUT AS THE WEAK FRONT MAKES IT
TO THE PIEDMONT...EXPECTING SOME MVFR CIGS TO DEVELOP AND CONTINUE
THROUGH JUST ABOUT DAYBREAK. TEMPS WARM ENOUGH FOR ANY LIGHT
SHOWERS TO BEGIN AS LIQUID WITH A TRANSITION TO SNOW TONIGHT.
THURSDAY THROUGH SUNDAY...THE REGION WILL REMAIN IN A VERY ACTIVE
NORTHWEST FLOW PATTERN WITH A SERIES OF CLIPPER SYSTEM RACING
THROUGH THE REGION ABOUT ONE EVERY TWO DAYS. THIS WILL ALLOW FOR
RELATIVELY BRIEF PERIOD OF SUB-VFR CONDITIONS WITH THESE FEATURES
FOLLOWED BY A VFR CONDITIONS IN BETWEEN SYSTEMS. CONFIDENCE IN
TIMING OF THESE FEATURES IS LOW AT THIS TIME. THE MOST LIKELY
PERIOD FOR SNOW SHOWERS AT THIS TIME LOOKS TO BE THURSDAY NIGHT
AND FRIDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR VAZ007-
009.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VAZ015.
NC...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NCZ001-
018.
WV...NONE.
&&
$$
SYNOPSIS...DS
NEAR TERM...DS
SHORT TERM...PM
LONG TERM...KM
AVIATION...MBS
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
929 PM CST THU JAN 16 2014
.UPDATE...LINGERING WEAK LOW TO MID-LEVEL DEFORMATION WILL
CONTINUE TO BRING SCATTERED LIGHT SNOW SHOWERS AND FLURRIES
TO THE AREA OVERNIGHT. COLDER AIR FUNNELING IN FROM THE WEST
SHOULD END THE THREAT FOR -FZDZ. STILL EXPECT OVERNIGHT LOWS TO
DIP INTO THE SINGLE DIGITS MOST AREAS WITH WIND CHILLS FALLING TO
BETWEEN 5 AND 15 BELOW. MORE NUMEROUS -SHSN EXPECTED ON FRIDAY AS
NEXT MID-LEVEL SHORT WAVE TROUGH CURRENTLY IN THE KDLH VCNTY
SWINGS ACROS THE AREA.
&&
.AVIATION/06Z TAFS/...CIGS WL VARY MOSTLY FROM MVFR TO VFR
OVERNIGHT DEPENDING ON LOCATION OF -SHSN. CIGS SETTLING INTO MVFR
CATEGORY ON FRIDAY AS MORE NUMEROUS -SHSN AFFECT SRN WI.
&&
.MARINE...COLDER AIR FUNNELING ACROSS LAKE MICHIGAN BEHIND EXITING
COLD FRONT WILL CONTINUE TO CAUSE GUSTY WINDS TO 25 KNOTS THROUGH
THE NIGHT. EXTENDED SMALL CRAFT ADVY THRU 12Z.
&&
.PREV DISCUSSION... /ISSUED 345 PM CST THU JAN 16 2014/
TONIGHT AND FRIDAY...FORECAST CONFIDENCE IS MEDIUM.
AREA OF LIGHT SNOW SHOWERS WILL CONTINUE TO ROTATE EASTWARD THROUGH
THE AREA LATE THIS AFTERNOON...FOLLOWING THE PASSING 500 MB
SHORTWAVE TROUGH. HRRR HAS A DECENT HANDLE ON THIS...AND SHIFTS THIS
AREA EAST OF THE LAKE MICHIGAN SHORELINE BY 02Z FRIDAY. EXPECT LIGHT
ACCUMULATIONS UP TO AROUND 1/2 INCH IN ANY HEAVIER ACTIVITY THROUGH
EARLY EVENING.
SOME QUESTION AS TO WHAT WILL HAPPEN WITH ANY SNOW SHOWER ACTIVITY
THIS EVENING. HRRR AND THE SYNOPTIC MODELS ARE INDICATING A BREAK IN
THE SNOW SHOWER ACTIVITY...AS AREA FORECAST SOUNDINGS SHOW DRYING IN
THE LOWER LEVELS IN DENDRITE ZONE AS THE EVENING GOES ON. THERE IS
SOME WEAK ACTIVITY UPSTREAM...WITHIN CYCLONIC FLOW AT 500 MB. NOT
MUCH IN THE WAY OF FORCING FOR UPWARD VERTICAL MOTION...SO THE DRY
PERIOD MAY INDEED OCCUR.
FOR NOW...WENT WITH LOWER POPS IN THE NORTHWEST HALF OF THE AREA
BETWEEN 02Z AND 06Z FRIDAY...WITH DRY CONDITIONS IN THE SOUTHEAST
HALF. THIS MAY NEED TO BE EXPANDED FURTHER NORTHWEST IF DRYING
OCCURS AS SHOWN IN MODELS. CONTINUED TO MENTION BLOWING SNOW IN THE
EVENING...WITH GUSTY NORTHWEST WINDS EXPECTED TO OCCUR BEHIND THE
EASTWARD ADVANCING COLD FRONT. SOME DRIFTING ISSUES MAY OCCUR ON
NORTH TO SOUTH ROADS THIS EVENING.
AREA FORECAST SOUNDINGS SHOW MOISTURE INCREASING LATER TONIGHT INTO
FRIDAY IN THE LOW LEVELS...WITHIN DENDRITE ZONE. THIS CORRESPONDS
WITH NEXT 500 MB VORTICITY MAXIMUM ROTATING SOUTHEASTWARD THROUGH
THE AREA LATER TONIGHT...WITH ANOTHER AFFECTING THE EAST FRIDAY
AFTERNOON. SO...BROUGHT POPS BACK INTO THE SCATTERED RANGE DURING
THIS PERIOD. THINGS DRY OUT IN THE WEST FRIDAY AFTERNOON...SO
BROUGHT DRY CONDITIONS THERE. ACCUMULATIONS UP TO AN INCH ARE
POSSIBLE LATER TONIGHT INTO FRIDAY.
COLD TEMPERATURES ARE EXPECTED TONIGHT...AS 925 MB TEMPERATURES DROP
INTO THE MID TEENS BELOW ZERO CELSIUS. THESE VALUES LINGER ON
FRIDAY. WENT SINGLE DIGITS ABOVE ZERO SOUTH AND CENTRAL...WITH 10 TO
12 ABOVE NORTH. HIGHS FRIDAY SHOULD ONLY REACH THE MID TEENS
WEST...TO THE LOWER 20S FAR EAST. WIND CHILLS WILL DROP TO THE 10 TO
15 BELOW ZERO RANGE ACROSS THE SOUTH LATER TONIGHT AND EARLY FRIDAY.
SHORT TERM...FRIDAY NIGHT THROUGH SUNDAY.
FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE MEDIUM.
RIDGING BRINGS A QUIET FRIDAY NIGHT THEN FOCUS IS ON
VIGOROUS...COMPACT SHORT WAVE DRIVEN BY THE UPPER LEVEL DIVERGENCE
IN THE LEFT EXIT REGION OF A 160 KNOT JET DROPPING A SURFACE LOW
DURING THE DAY SATURDAY ACROSS THE REGION FROM CENTRAL MN...OVER THE
VICINITY OF ROCHESTER/LA CROSSE TO NEAR OR SOUTH OF CHICAGO BY 00Z
SUNDAY
12Z ECMWF NOW MORE IN LINE WITH THE 12Z RUNS OF THE GFS AND GEMNH
WHICH ARE SLIGHTLY FASTER AND FARTHER WEST WITH THE SURFACE LOW THAN
12Z NAM AND THE 00Z ECMWF.
NAM AND GEM KEEP WAA PCPN OUT OF CWA PRIOR TO 12Z SATURDAY...WITH
GFS AND ECMWF...WHICH BRING SNOW INTO FAR WESTERN COUNTIES BETWEEN
09Z AND 12Z. WILL ACKNOWLEDGE WITH A SLIGHT CHANCE OF SNOW IN THE
FAR WEST AFTER 09Z.
RAISED POPS TO CATEGORICAL WITH IMPRESSIVE 850-300MB Q-VECTOR
CONVERGENCE CROSSING THE REGION...WITH OMEGA OF 8 TO 10 MICROBARS
INTERSECTING THE DENDRITE GROWTH ZONE.
EVERYONE WILL SEE ACCUMULATING SNOW DURING THE MORNING...THEN
TAPERING OFF FROM NW TO SE DURING THE AFTERNOON. STILL A QUESTION TO
AMOUNTS. NAM THE OUTLIER WITH HIGHER QPF...WHICH HAS BEEN A
REPEATING TREND THIS WINTER. WENT WITH A CONSENSUS BLEND OF QPF AND
SNOW RATIOS WHICH YIELDS FROM 2 TO 2.5 INCHES IN THE FAR SW AND FAR
NE...UP TO 4 INCHES IN THE SE CWA WITH A CONSENSUS LOW TRACK
BRINGING THE AXIS OF HIGHER AMOUNTS ALONG AND EITHER SIDE OF A
DELLS...WATERTOWN TO KENOSHA LINE. IF THE LOW TRACKS FARTHER WEST
THAN CURRENT FORECAST...IT COULD BRING A PERIOD OF LAKE-ENHANCED/
LAKE-EFFECT SNOW TO THE EAST.
LOWS EARLY FRIDAY NIGHT WITH 925 MB THERMAL TROUGH CENTERED OVER
REGION AT 06Z THEN INCREASING CLOUDS AND TEMPS WITH WAA BRING STEADY
TEMPS OVERNIGHT...WITH A SLIGHT RISE TOWARD DAYBREAK. DIFFERING
TRACKS OF SYSTEM BRINGS VARYING DEGREES OF WARMTH INTO THE FORECAST
AREA. BLENDED TEMPS BRING HIGHS AROUND 20 TO 25.
SATURDAY NIGHT AND SUNDAY...FORECAST CONFIDENCE MEDIUM.
DRY WEATHER WITH WEAK RIDGING SATURDAY NIGHT AND SUNDAY. TEMPS
SLOWLY COOL WITH WEAK COLD AIR ADVECTION THROUGH AROUND
MIDNIGHT...THEN WARM AIR ADVECTION AHEAD OF DEVELOPING SURFACE LOW
NORTH OF LAKE SUPERIOR AS CLOSED UPPER LOW AROUND HUDSON BAY
DEEPENS...BRINGS STEADY TEMPS WITH ANOTHER SLOW RISE TOWARD
DAYBREAK. MODELS DIFFER WITH SPEED OF TRAILING COLD FRONT DROPPING
THROUGH STATE ON SUNDAY...WITH THE GFS BRINGING -8C TO -10C 925MB
TEMPS INTO SRN WI BY 18Z SUNDAY...WITH THE NAM AND ECMWF STILL AT OR
ABOVE 0C AT 00Z MONDAY. A CONSENSUS YIELDS HIGH TEMPERATURES IN THE
UPPER 20S TO LOWER 30S...BUT IF THE WARMER NAM AND ECMWF
VERIFY...COULD SEE TEMPS AT LEAST 5 DEGREES WARMER.
LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. FORECAST CONFIDENCE
LOW.
MODELS IN REASONABLE AGREEMENT TO DEGREE OF COLD AIR BEHIND COLD
FRONT FOR SUNDAY NIGHT INTO THE EARLY PORTION OF NEXT WEEK. 925 MB
TEMPS FALL TO -20C TO -25C BY TUESDAY MORNING DEPENDING ON MODEL.
ADJUSTED ALL BLEND TEMPERATURES DOWNWARD TO REFLECT COLDER LOOK. THE
LOW CHANCE/SLIGHT CHANCE POPS ON MONDAY/MONDAY NIGHT DUE TO MORE
SOUTHERLY TRACK OF SURFACE LOW ON GEM...BUT ENOUGH SHORT WAVE ENERGY
MOVING THROUGH THE REGION UNDER CLOSED HUDSON BAY LOW TO WARRANT
POPS. MODELS KEEP AREA DRY WITH SURFACE HIGH PRESSURE TUESDAY
THROUGH WEDNESDAY NIGHT...BUT CONTINUED PARADE OF SHORT WAVE ENERGY
COULD BRING AT LEAST ROUNDS OF FLURRIES/LIGHT SNOW SHOWERS. BETTER
CHANCE COMES WITH DEEPER WAVE THURSDAY/FRIDAY...THOUGH DIFFERING
MODEL TIMING SMEARS LOW CHANCE POPS ACROSS THE END OF THE
EXTENDED.
AVIATION/00Z TAFS/...
VISIBILITIES BELOW ALTERNATE MINIMUMS WITH CEILINGS OF 1000 TO 1500
FEET ABOVE GROUND LEVEL ARE EXPECTED WITH THE SNOW SHOWERS THROUGH
THE EARLY EVENING HOURS. SOUTHWEST WINDS WILL SHIFT WEST NORTHWEST
AND BECOME GUSTY AT MADISON BY 22Z THURSDAY...AND AT THE EASTERN
SITES BY 00Z FRIDAY. SOME BLOWING SNOW AND DRIFTING SNOW IS EXPECTED
ON NORTH TO SOUTH RUNWAYS. A QUICK 1/2 INCH OR SO IN A HALF HOUR IS
POSSIBLE IN ANY OF THE HEAVIER SNOW SHOWERS.
THERE SHOULD BE A LULL IN THE SNOW SHOWER ACTIVITY FROM 02Z TO 06Z
FRIDAY...WITH VFR VISIBILITIES AND MVFR CEILINGS. GUSTY WEST
NORTHWEST WINDS WILL CONTINUE TO BRING SOME BLOWING AND DRIFTING
SNOW...BUT SHOULD NOT REDUCE VISIBILITIES MUCH.
SNOW SHOWERS SHOULD RETURN AFTER 06Z FRIDAY...LINGERING INTO THE
MORNING HOURS AT MADISON...AND THE AFTERNOON AT THE EASTERN SITES.
VISIBILITIES SHOULD REMAIN AROUND ALTERNATE MINIMUMS. AGAIN...COULD
SEE A QUICK 1/4 TO 1/2 INCH IN A HALF HOUR WITH ANY HEAVIER SNOW
SHOWERS...TOTALS UP TO AN INCH AT BEST. GUSTY WEST NORTHWEST WINDS
WILL LINGER...BUT WILL SLOWLY WEAKEN IN THE AFTERNOON.
MARINE...
SMALL CRAFT ADVISORY CONTINUES UNTIL MIDNIGHT TONIGHT FOR THE
NEARSHORE WATERS OF LAKE MICHIGAN. WINDS WILL SHIFT TO THE WEST
NORTHWEST AND BECOMING GUSTY ONCE AGAIN BY 00Z FRIDAY...AFTER A
STRONG COLD FRONT MOVES THROUGH. THESE WINDS WILL LINGER THROUGH THE
EVENING HOURS...BEFORE FALLING SLIGHTLY BELOW CRITERIA BY MIDNIGHT.
ANY HIGH WAVES TOWARD THE OPEN WATERS THIS EVENING WILL SUBSIDE BY
LATER TONIGHT.
HOWEVER...THE SMALL CRAFT ADVISORY MAY NEED TO BE EXTENDED THROUGH
FRIDAY...AS THE PRESSURE GRADIENT TIGHTENS UP AGAIN FRIDAY MORNING
INTO THE AFTERNOON. SOME GUSTS TO 25 KNOTS ARE POSSIBLE...THOUGH
OFFSHORE FLOW WILL KEEP HIGH WAVES OVER THE OPEN WATERS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 AM CST FRIDAY FOR LMZ643>646.
&&
$$
UPDATE...MBK
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
351 AM EST FRI JAN 17 2014
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 350 AM EST FRI JAN 17 2014
07Z SFC ANALYSIS SHOWS THE LATEST CLIPPER SYSTEM MOVING THROUGH THE
GREAT LAKES. THIS IS PUSHING AN ARCTIC BOUNDARY INTO THE WESTERN
PORTIONS OF THE OHIO VALLEY. AHEAD OF THIS...A DISTURBANCE AT MID
LEVELS HAS SENT A NEW BATCH OF SNOW SHOWERS THROUGH EAST KENTUCKY
WHITENING SOME PLACES UP TO AN INCH AS IT PASSES. AT THE WEATHER
OFFICE WE PICKED UP A QUICK 7 TENTHS OF AN INCH AS ONE OF THOSE BANDS
MOVED THROUGH. TEMPERATURES AROUND FREEZING AND ROAD TEMPERATURES IN
MOST PLACES ABOVE FREEZING WILL LIMIT THE IMPACT FROM THESE SNOW
SHOWERS. OVER THE SOUTHERN PARTS OF THE CUMBERLAND VALLEY THE
DEWPOINTS HAVE COME UP INTO THE LOW TO MID 30S AND THIS IS LEADING TO
MORE OF A RAIN EVENT WITH THIS ROUND RATHER THAN SNOW. IT IS A FINE
LINE...THOUGH...SO WILL CONTINUE THE SPS THAT IS OUT THROUGH 16Z FOR
THAT AREA. DESPITE A FEW HEAVIER BANDS...THE BULK OF THE AREA WILL
SEE AROUND A HALF AN INCH OF ACCUMULATION OR LESS THOUGH DAWN.
SLIGHTLY BETTER TOTALS CAN BE EXPECTED ALONG AND IN THE IMMEDIATE
WAKE OF THE ARCTIC BOUNDARY LATER TODAY.
THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT AS THEY ALL SHOW A
POTENT SHORTWAVE CROSSING THROUGH THE SOUTHERN OHIO VALLEY TODAY
WITHIN THE HEART OF A DEEP TROUGH. THIS WAVE WILL BRING SOME STEEP
LAPSE RATES TO THE LOWER PART OF THE ATMOSPHERE LATER THIS MORNING
AND THROUGH THE AFTERNOON HELPING TO ENHANCE THE LIFT AND SHOWERY
NATURE OF THE SNOW. THIS FEATURE MOVES QUICKLY OFF TO THE NORTHEAST
TONIGHT AS THE LARGER TROUGH TEMPORARILY RETREATS TO THE NORTH.
ACCORDINGLY...HEIGHTS WILL MODERATE THROUGH THE AREA INTO SATURDAY
MORNING. THIS PROCESS IS THEN QUICKLY REVERSED LATER THAT DAY AS THE
NEXT SHARP WAVE DROPS SOUTHEAST THROUGH THE MIDWEST...MAKING ITS RUN
TOWARD THE OHIO VALLEY. WITH THE GENERAL MODEL AGREEMENT AND THE
MESOSCALE NATURE OF THE SNOW BANDS AND ARCTIC BOUNDARY...HAVE LEANED
TOWARD THE HIGHER RESOLUTION HRRR AND NAM12 THROUGH THE SHORT TERM.
SENSIBLE WEATHER WILL FEATURE THE PRE-DAWN SNOW...AND FAR SOUTHERN
KY RAIN...SHOWERS EXITING THE AREA WITH A BIT OF A LULL IN ANY PCPN
ACTIVITY UNTIL AROUND MID MORNING IN THE WEST WHEN THE ARCTIC
BOUNDARY MOVES INTO THE CWA. THIS WILL BRING ANOTHER ROUND OF SNOW
SHOWERS...COLDER TEMPERATURES...AND BRISK WINDS TO THE AREA TODAY.
ALTHOUGH MOISTURE IS LIMITED WITH THIS...STILL EXPECT THE LIFT ALONG
THE FRONT AND STEEP LAPSE RATES BEHIND IT TO SUPPORT SNOW SHOWERS
INTENSE ENOUGH TO ACCUMULATE FOR MOST LOCATIONS...GENERALLY A HALF TO
ONE INCH THROUGH EARLY EVENING. TWO INCHES OR MORE INCHES WILL BE
POSSIBLE IN THE HIGHEST TERRAIN NEAR THE VIRGINA BORDER THROUGH
MIDNIGHT. IN ADDITION TO THE SNOW...BRISK WINDS ACCOMPANYING THE SNOW
WILL LIMIT VISIBILITIES AT TIMES TO A MILE OR LESS...POTENTIALLY
CREATING BRIEF PERIODS OF HAZARDOUS TRAVEL. THE SNOW SHOWERS WILL
TAPER TO FLURRIES AND END FROM WEST TO EAST ON SATURDAY NIGHT WITH
TEMPERATURES PLUMMETING INTO THE TEENS BY DAWN. FOR THE BULK OF THE
DAY SATURDAY THE WX WILL BE QUIET BETWEEN DISTURBANCES. HOWEVER...BY
EVENING THICKER AND LOWER CLOUDS WILL BE ROLLING BACK IN FROM THE
NORTHWEST WITH SOME SNOW POSSIBLE BEFORE DARK IN OUR NORTHWEST
COUNTIES.
FOR THE ARCTIC BOUNDARY MOVING THROUGH THE CWA THIS MORNING AND
AFTERNOON WILL ISSUE AN EXTENSION TO THE WSW TO COVER THE ENTIRE
CWA...LINGERING IT INTO THE LATE EVENING IN THE FAR EAST. THE ONLY
DIFFERENCE FROM THE CURRENT ONE IS THAT THIS EXTENSION WILL NOT GO
INTO EFFECT UNTIL AFTER 15Z.
FOLLOWED A BLEND OF THE DIURNAL FROM NAM12 AND THE CONSSHORT FOR
HOURLY TEMPS WHILE FAVORED THE BCCONSSHORT FOR TD AND WINDS THROUGH
THE FIRST 24 HOURS...STARTING WITH THE CONSALL THEREAFTER AND FOR MAX
AND MIN TEMPS THROUGH SATURDAY. AS FOR POPS...ENDED UP HIGHER THAN
ALL GUIDANCE FOR TODAY THROUGH TONIGHT GIVEN THE LOW QPF NATURE OF
THIS EVENT.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 337 AM EST FRI JAN 17 2014
AN ACTIVE AND VERY PROGRESSIVE EXTENDED PERIOD BEGINS ON SATURDAY
NIGHT WITH A POSITIONED BROAD TROUGH OVER THE NORTHEASTERN CONUS AND
REMAINING THERE FOR THE ENTIRE EXTENDED. BEFORE DELVING INTO THE
SPECIFICS...THE MODELS DO AGREE ON A RIDGE TROUGH LONGWAVE PATTERN
THROUGH THE EXTENDED. THE TRUE FORECAST CHALLENGE FOR THIS PERIOD
FALLS ON HOW THE MODELS HANDLE THE ARRIVAL OF EACH SHORT WAVES THAT
WILL ROTATE DOWN OUT OF CANADA AND INTO THE GREAT LAKES OHIO VALLEY
REGION. THIS COUPLE WITH THE CHALLENGE OF DETERMINING THE MOISTURE
AVAILABLE...WILL BE QUITE A PROBLEM.
THIS IN MIND...WILL STAY CLOSE TO THE MODEL ALL BLEND AND ENSEMBLE
SOLUTIONS AND DECREASING PROBABILITIES WHERE CONFIDENCE IS LOW. THE
FIRST SIGNIFICANT WAVE MOVES THROUGH THE AREA ON SUNDAY. WITH THE
COLDER AIR ALREADY IN PLACE...THE PRECIP TYPE WITH THIS SYSTEM
SHOULD FALL AS SNOW AND THE INSTABILITY THE MODEL PROFILES ARE
SHOWING WOULD INDICATE AT SOME ACCUMULATING SNOWFALL POSSIBLE WITH
TEMPS COLD ENOUGH AND A GOOD SHOT OF OMEGA IN THE SATURATED -10 TO
-20 REGION FOR A GOOD 2 TO 3 HOUR PERIOD ON SUNDAY MORNING. WILL
NEED TO WATCH FOR THIS SYSTEM...ESPECIALLY WITH A FAVORABLE WIND
DIRECTION FOR SOME UP SLOPE ASSISTANCE. MODELS DO HAVE A GOOD BIT
AGREEMENT WITH THIS AND THIS WAVE IS POSSIBLY THE ONLY WAVE TO PUT
SOME CONFIDENCE IN AS AFTER THIS FEATURE MOVES THROUGH...THE MODELS
WAFFLE WITH THE CHARACTERISTICS OF THE SHORTWAVES LATER IN THE
EXTENDED.
AFTER THIS STRONG WAVE ON SUNDAY PUSHES THROUGH...A BUILDING ARCTIC
AIR MASS WILL DIVE SOUTH AS THE SEMI PERMANENT 500 TROUGH OVER THE
NORTHEAST DIGS A BIT FURTHER SOUTH INTO THE SOUTHERN APPALACHIANS.
THIS WILL BRING TEMPS INTO THE 20S FOR HIGHS AND TEENS FOR LOWS BY
TUESDAY AND THROUGH THE REST OF THE EXTENDED. THE FOLLOWING PIECES
OF ENERGY ON TUESDAY AND THURSDAY ARE QUITE WEAK AND EVEN THE EURO
IS INCONSISTENT WITH THESE WAVES AS IT WILL SHIFT THE WAVES ABOUT 1
TO 2 HUNDRED MILES TO THE EAST FROM RUN TO RUN. WITH THIS TYPE OF
INCONSISTENCY...HAVE GONE WITH SLIGHT CHANCE POPS FROM DAY 4 THROUGH
DAY 7. THE COLDER TEMPS EXPECTED THOUGH WILL ASSURE ANY PRECIP
FALLING AFTER DAY 4 WILL BE SNOW. IT IS SOMEWHAT ENCOURAGING THAT
TELECONNECTIONS AT THIS POINT SUPPORT FALLING TEMPS AFTER TUESDAY SO
THAT IS ONE PARAMETER THAT CAN BE COUNTED ON.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1255 AM EST FRI JAN 17 2014
THE NEXT ROUND OF SNOW IS INBOUND TO THE SOUTHERN TAFS AND WILL
OVERSPREAD THE REST OF THE AREA DURING THE NEXT SEVERAL HOURS. WITH
THIS...CIGS WILL GRADUALLY FALL TO THE MVFR RANGE BY 09Z. A LULL IN
THE LOWER CLOUDS AND PCPN WILL THEN FOLLOW INTO MID AND LATE MORNING
HOURS OF FRIDAY SO THAT THERE MAY BE LITTLE IN THE WAY OF VIS OR CIG
RESTRICTIONS. HOWEVER...ANOTHER BATCH OF SNOW LASTING DURING THE
AFTERNOON FRIDAY WITH AN ACCOMPANYING ARCTIC BOUNDARY SHOULD BE
ENOUGH FOR VIS AND CIGS TO FALL BACK DOWN TO MVFR AND BRIEFLY WORSE.
THIS LAST AREA OF SNOW WILL GRADUALLY WANE INTO THE EVENING WITH CIGS
LIKELY IMPROVING AND VIS ABOVE 6 MILES EVEN AS A FEW FLURRIES
CONTINUE OVER THE AREA. WINDS WILL BE SOUTHWEST AT 5 TO 10 KTS WITH
AN OCCASIONAL GUST TO 15 KTS UNTIL AROUND 15Z WHEN THE BOUNDARY
MOVES IN AND SWITCHES THEM TO THE WEST AT 10 TO 20 KTS FOR THE BULK
OF THE DAY...DIMINISHING BELOW 10 KTS ONLY DURING THE EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR KYZ044-
050>052-058>060-068-069-079-080-104-106-108-111-114.
WINTER WEATHER ADVISORY FROM NOON TODAY TO MIDNIGHT EST TONIGHT
FOR KYZ087-088-110-113-115-117-118-120.
WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO 9 PM EST THIS
EVENING FOR KYZ083>086-107-109-112-116-119.
&&
$$
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS PORTLAND OR
912 PM PST THU JAN 16 2014
.SYNOPSIS...HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH
SATURDAY MORNING...ALLOWING VALLEY FOG AND LOW CLOUDS TO PERSIST
WHILE MILD AND SUNNY CONDITIONS WILL DOMINATE THE WEATHER FOR COASTAL
AND MOUNTAIN LOCATIONS. A WEAK FRONT ARRIVING LATE SATURDAY INTO
SUNDAY WILL BRING A SMALL CHANCE FOR LIGHT RAIN TO THE COAST.
OTHERWISE...HIGH PRESSURE IS EXPECTED TO DOMINATE THE WEATHER AGAIN
NEXT WEEK AND BRING MORE OF SAME WEATHER OF LATE.
&&
.SHORT TERM...DENSE FOG IS BEGINNING TO FILL IN THE WILLAMETTE VALLEY
TONIGHT AND THE ONLY CHANGE MADE TO THE FORECAST WAS TO ISSUE A DENSE
FOG ADVISORY FOR THE WILLAMETTE VALLEY TONIGHT THROUGH THURSDAY
MORNING. THE FOG IS NOT WIDESPREAD YET...BUT IS LOCATED AROUND THE
MAJOR HIGHWAYS AND TRAVELERS WILL NEED TO EXERCISE EXTRA CAUTION.
EASTERLY WINDS MAY RESULT IN FOG CLEARING THAN ANTICIPATED...BUT
THINK THE STRONG INVERSION WILL BE DIFFICULT TO DISRUPT. HARTLEY
PREVIOUS DISCUSSION FOLLOWS...A SUBSTANTIAL SUBSIDENCE INVERSION LIES
BETWEEN 1000 AND 3000 FEET TODAY...RESULTING IN TEMPERATURES WARMING
AT LEAST 20 DEGREES AS ONE GOES UP BETWEEN THESE TWO ELEVATIONS.
WHILE RAWS STATIONS HAVE A WARM BIAS ON LOW WIND...SUNNY DAYS...60S
CERTAINLY ABOUND ACROSS MOST OF THE HIGHER HILLS IN THE COAST RANGE
AND CASCADE FOOTHILLS.
VISIBLE SATELLITE IMAGERY INDICATES LOW CLOUDS ARE HANGING TOUGH
ACROSS THE SOUTHERN HALF OF THE WILLAMETTE VALLEY...NORTH OF I84 IN
THE PORTLAND METRO AREA AND ALONG THE KELSO TO CASTLE ROCK CORRIDOR
THIS AFTERNOON. IT IS CERTAINLY INTERESTING THAT MCMINNVILLE AND
HILLSBORO CLEARED BEFORE KTTD AND KPDX. THE HRRR INDICATES LOW LEVEL
WINDS WILL REMAIN NORTHWESTERLY ALONG THE COLUMBIA RIVER NEAR KPDX
AND KTTD UNTIL LATE TONIGHT SO THESE AREAS WILL BE HARD PRESSED TO
GO COMPLETELY CLEAR THIS AFTERNOON BASED ON VISIBLE SATELLITE
TRENDS. WHAT CLEARING DOES OCCUR SHOULD BE SHORT LIVED AS CLOUDS AND
FOG FILL BACK IN QUICKLY THIS EVENING.
THE CURRENT KDLS-KTTD PRESSURE GRADIENT IS HOVERING NEAR 4MB AND
SHOULD RAMP UP LATER TONIGHT TO APPROXIMATELY 6MB...PERHAPS 7MB.
BECAUSE THE KDLS-KTTD PRESSURE GRADIENT SHOULD ONLY BE STRONGER
FRIDAY MANY OF THE SAME AREAS WILL CLEAR FRIDAY AFTERNOON...PLUS
THOSE THAT WERE OH SO CLOSE TODAY INCLUDING CLARK COUNTY AND PERHAPS
SALEM. EXPECT TEMPERATURES TO BE SIMILAR FRIDAY...BUT A TOUCH COOLER
NEAR THE CENTRAL OREGON COAST WHERE LOW LEVEL WINDS WILL TURN A
LITTLE MORE SOUTHERLY.
OTHERWISE...A SHORTWAVE TROUGH STILL LOOKS ON TRACK TO SLIDE EASTWARD
WELL NORTH OF OUR CWA LATE SATURDAY. THIS WILL DRAG A DYING FRONT
INTO OUR COASTAL WATERS WITH A SLIGHT CHANCE THAT MEASURABLE RAIN
WILL OCCUR ALONG THE NORTHWEST OREGON COAST AND FAR SOUTHWEST
WASHINGTON. HOWEVER...DPROG/DT CONTINUES TO SUGGEST THIS IS LESS AND
LESS LIKELY. RIDGING WILL THEN BEGIN TO BUILD NORTHWARD ACROSS THE
NORTHEAST PACIFIC ON SUNDAY. THE REMNANTS OF THE AFOREMENTIONED
FRONT WILL LIFT NORTHWARD AND ACT AS A WARM FRONT...BRINGING ANOTHER
SMALL CHANCE FOR LIGHT PRECIPITATION SUNDAY...BUT AGAIN MODELS SEEM
TO BE TRENDING DRIER WITH THIS SYSTEM SO POPS WERE KEPT GENERALLY
SLIGHT CHANCE OR LESS. /NEUMAN
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. FEW CHANGES IN THE
EXTENDED PERIOD. AFTER THE WEAK FRONT PASSES THROUGH THE AREA ON
SUNDAY...HIGH PRESSURE WILL QUICKLY REBUILD OVER THE EASTERN PACIFIC
AND PACIFIC NORTHWEST. THIS RIDGE WILL CONTINUE TO DOMINATE OUR
WEATHER PATTERN AND BY TUESDAY THE UPPER RIDGE WILL AMPLIFY WITH THE
RIDGE AXIS LOCATED ALONG OR NEAR THE WEST COAST. BOTH THE 12Z ECMWF
AND GFS DEPICT A SHORTWAVE IMPULSE THAT SPLITS NEAR 140W EARLY NEXT
WEEK...WITH A CLOSED LOW MOVING INTO THE CENTRAL CA COAST AND AN
UPPER LEVEL TROUGH WELL TO OUR NORTH OVER THE TOP OF THE RIDGE.
UNTIL THE FORECAST MODELS GIVE A STRONG REASON TO BELIEVE
OTHERWISE...IT APPEARS THIS RIDGE WILL CONTINUE REMAIN IN PLACE AND
KEEP THE FORECAST AREA DRY THROUGH AT LEAST LATE NEXT WEEK.
A RETURN OF DAILY FOG AND LOW CLOUDS IS LIKELY FOR THE VALLEY
LOCATIONS...THOUGH THE NORTH WILLAMETTE VALLEY MAY BE MORE LIKELY TO
SEE LESS FOG AND/OR BREAK OUT EARLIER DURING THE MIDDLE OF NEXT WEEK
DEPENDING ON EAST WINDS DEVELOPING THROUGH THE COLUMBIA RIVER GORGE.
HIGH TEMPERATURES LOOK TO BE A FEW DEGREES ABOVE SEASONAL NORMALS
THROUGH THE EXTENDED WHILE LOWS WILL BE NEAR NORMS. CULLEN
&&
.AVIATION...AFTER SOME CLOUD BREAKS THIS AFTERNOON...WIDESPREAD
LIFR VALLEY FOG HAS RETURNED THIS EVENING. OFFSHORE GRADIENT
STRENGTHENS OVERNIGHT AND INTO FRIDAY...WHICH WILL ALLOW NORTH
VALLEY CLEARING AND POSSIBLY A BIT MORE ON FRIDAY. VFR CONDITIONS
PREVAIL ALONG THE COAST AND MOUNTAINS.
KPDX AND APPROACHES...LIFR FOG CONTINUES THROUGH AT LEAST 18Z-20Z
FRIDAY MORNING. OFFSHORE GRADIENT WILL BEGIN WORKING ITS WAY
TOWARDS EASTERN APPROACHES WHICH SHOULD HELP TO ERODE CLOUDS OR
AT LEAST LIFT CLOUDS AND VSBYS WITH GOOD CLEARING FOR TOMORROW
AFTERNOON. KMD/27
&&
.MARINE...HIGH PRES REMAINS OVER THE PAC NW THROUGH THE WEEKEND.
THIS WILL MAINTAIN WEAK PRES GRADIENTS AND E WINDS 15 KT OR
LESS...THOUGH EXPECT SOME GUSTS TO 20 KT FROM TIME TO
TIME...MAINLY ON FRI. SEAS CONTINUE TO SUBSIDE.
A WEAK FRONT WILL PUSH ACROSS REGION THIS WEEKEND...BUT NOT MUCH
IN WAY OF WIND. WILL SEE SEVERAL SWELL TRAINS OF 10 TO 12 FT
ARRIVING THIS WEEKEND INTO EARLY NEXT WEEK. ROCKEY.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...AIR STAGNATION ADVISORY UNTIL 10 AM PST TUESDAY FOR CENTRAL
WILLAMETTE VALLEY-SOUTH WILLAMETTE VALLEY.
DENSE FOG ADVISORY UNTIL 9 AM PST FRIDAY FOR CENTRAL WILLAMETTE
VALLEY-GREATER PORTLAND METRO AREA-SOUTH WILLAMETTE VALLEY.
WA...DENSE FOG ADVISORY UNTIL 9 AM PST FRIDAY FOR GREATER VANCOUVER
AREA.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
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 LA CROSSE WI
340 AM CST FRI JAN 17 2014
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 340 AM CST FRI JAN 17 2014
MAIN FORECAST CONCERN IN THE SHORT TERM WILL BE LIGHT SNOW CHANCES
THIS MORNING...AND THEN ACCUMULATING SNOW LIKELY AGAIN LATER
TONIGHT THROUGH SATURDAY.
WATER VAPOR/RAP 500MB ANALYSIS/SURFACE OBSERVATIONS SHOW A CLOSED
MID-LEVEL CYCLONIC CIRCULATION AND SURFACE LOW OVER NORTHERN LOWER
MI WITH LIGHT DEFORMATION SNOW ROTATING INTO ALL THE WAY BACK INTO
OUR FORECAST AREA. WINDS STILL A BIT BRISK ACROSS THE FORECAST
AREA...GENERALLY IN THE 10-20 MPH WITH SOME GUSTS AROUND 25 MPH YET
ACROSS THE OPEN AREAS OF SOUTHEAST MN/NORTHEAST IA. MEANWHILE...
TEMPERATURES AT 2 AM WERE IN THE SINGLE DIGITS ABOVE ZERO WHILE WIND
CHILLS WERE IN THE SINGLE DIGITS AND TEENS BELOW ZERO. A WIND CHILL
ADVISORY IS IN EFFECT UNTIL 11 AM THIS MORNING ACROSS PORTIONS OF
NORTHEAST IA AND SOUTHEAST MN WHERE WIND CHILLS WILL BE TOUCHING
CRITERIA IN THE 15 BELOW TO 25 BELOW ZERO RANGE.
PLAN ON AREAS OF LIGHT SNOW TO CONTINUE ROTATING SOUTH AND EAST
ACROSS THE AREA EARLY ON THIS MORNING...EXITING EAST BY LATER IN THE
MORNING AS THE LOW OVER NORTHERN MI PUSHES INTO SOUTHEAST ONTARIO
AND A NARROW RIDGE OF HIGH PRESSURE PUSHES IN FROM THE PLAINS. THIS
RIDGE WILL ALSO AID IN CLEARING THE SKIES FROM WEST TO EAST LATE
THIS MORNING THROUGH THE AFTERNOON HOURS. OTHERWISE...LOOK FOR
CHILLY TEMPERATURES TODAY WITH HIGHS ONLY IN THE SINGLE DIGITS AND
TEENS ABOVE ZERO.
FOR TONIGHT...LOOK FOR THE RIDGE OF HIGH PRESSURE TO PASS OVER AND
EAST OF THE REGION THIS EVENING...WHILE A VIGOROUS MID-LEVEL
CYCLONIC CIRCULATION AND SURFACE LOW DROPS SOUTHEAST OUT OF ALBERTA
INTO CENTRAL MN BY 12Z. THIS WILL SPREAD/THICKEN CLOUD COVER BACK
INTO THE REGION...WHILE INCREASING 850-500MB FRONTOGENESIS AND
ISENTROPIC LIFT AHEAD OF THE LOW EXPECTED TO PRODUCE SATURATION
THROUGH THE COLUMN FOR SNOWFALL STARTING AFTER 09Z. THIS IS EXPECTED
MAINLY SOUTHWEST OF THE I-94 CORRIDOR. TEMPERATURES SHOULD DIVE
FAIRLY QUICK THIS EVENING INTO THE SINGLE DIGITS ABOVE AND BELOW
ZERO THROUGH ABOUT MIDNIGHT...THEN SLOWLY RISE THROUGH THE EARLY
MORNING HOURS. MODEL CONSENSUS/DPROG-DT SHOW THE TRACK OF THE LOW
SHIFTING A BIT FARTHER WEST ACROSS SOUTHEAST MN/EASTERN IA IN THE
LAST FEW RUNS. THIS WOULD PUT AREAS ALONG AND WEST OF THE MISSISSIPPI
IN THE HEAVIEST SNOW AXIS. THINKING RIGHT NOW SNOWFALL OF 3-4 INCHES
LOOKS LIKELY...WITH THE BULK OF THE SNOW FALLING FROM 12Z SAT TO
AROUND 18-21Z TIME FRAME. IN ADDITION...WILL LIKELY SEE SOME BLOWING
SNOW AGAIN ACROSS PORTIONS OF NORTHEAST IA/SOUTHEAST MN LATE
SATURDAY MORNING THROUGH THE AFTERNOON HOURS. WITH ALL THIS IN
MIND...HAVE HOISTED A WINTER WEATHER ADVISORY FOR A PORTION OF
SOUTHWEST WI AND ALL OF SOUTHEAST MN/NORTHEAST IA FROM 09Z OR 3 AM
SATURDAY THROUGH 00Z SUN OR SATURDAY 6 PM.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 340 AM CST FRI JAN 17 2014
MODERATING TEMPERATURES SUNDAY THEN COLDER NORTHWEST FLOW THROUGH
THE REST OF THE WEEK WILL BE THE MAIN FORECAST CHALLENGE IN THE
LONG TERM PERIOD.
AFTER THE SNOW-PRODUCING WAVE PASSES SOUTHEAST OF THE AREA SATURDAY
NIGHT...MID-LEVEL RIDGING TAKES PLACE ACROSS THE NORTHERN PLAINS
INTO THE UPPER MISSISSIPPI RIVER VALLEY REGION. THE BUILDING RIDGE
AND INCREASING WARM AIR ADVECTION IN ADVANCE OF A COLD FRONT
DROOPING SOUTH ACROSS ONTARIO EXPECTED TO PRODUCE HIGHS ON SUNDAY IN
THE MID 20S ACROSS NORTH CENTRAL WI...TO THE LOWER AND MIDDLE 30S
ELSEWHERE.
17.00Z GFS AND ECMWF SHOWING THE COLD FRONT OVER SOUTHERN
ONTARIO...DROPPING SOUTH ACROSS THE AREA ON SUNDAY...MARKING THE END
TO THE MILDER WEATHER AND BACK TO COLDER NORTHWEST FLOW THROUGH THE
REST OF THE PERIOD. A MID-LEVEL TROUGH IN THE NORTHWEST FLOW DROPS
ACROSS THE AREA ON MONDAY FOR A CHANCE OF SOME VERY LIGHT SNOWFALL.
WILL HAVE TO KEEP A LEARY EYE ON MODEL RUNS FROM DAY TO DAY DUE TO
UNTRUSTWORTHY NORTHWEST FLOW AND HARD TO TIME EMBEDDED SHORTWAVE
TROUGHS FOR SNOW CHANCES.
OTHERWISE...TEMPERATURES WILL DROP BACK TO BELOW NORMAL LEVELS FROM
MONDAY THROUGH THURSDAY WITH HIGHS GENERALLY IN THE SINGLE DIGITS
AND TEENS ABOVE ZERO AND LOWS IN THE SINGLE DIGITS TO LOWER TEENS
BELOW ZERO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1106 PM CST THU JAN 16 2014
THE 17.00Z NAM AND 17.01Z HRRR CONTINUE TO SUGGEST THE
POSSIBILITY OF ANOTHER SNOW BAND MOVING ACROSS THE AREA
OVERNIGHT. THIS WOULD BE IN RESPONSE TO THE SHORT WAVE TROUGH OVER
NORTHWEST WISCONSIN AS IT MOVES SOUTHEAST AND PRODUCES SOME WEAK
QG CONVERGENCE OVER THE AREA. REGIONAL RADARS AND SURFACE
OBSERVATIONS DO SHOW SOME SNOW WITH THE WAVE SO HAVE CONTINUED THE
TREND OF BRINGING THIS INTO KLSE OVERNIGHT WITH MVFR CONDITIONS.
THE MODELS HAVE CUT BACK ON THE WESTERN EXTENT OF THE SNOW WHICH
SEEMS TO FIT THE CURRENT ACTIVITY AND HAVE BACKED OFF TO JUST
FLURRIES FOR KRST WITH A LOWERING OF THE CEILING. EXPECT THE SNOW
TO QUICKLY MOVE OUT FRIDAY MORNING WITH A RETURN TO VFR CONDITIONS
AND THEN THE CLOUDS SHOULD SCATTER OUT DURING THE LATE MORNING OR
EARLY AFTERNOON AS A HIGH PRESSURE RIDGE BUILDS IN. THIS RIDGE
WILL GET PUSHED SOUTH OF THE AREA FRIDAY EVENING AS THE NEXT
SYSTEM RAPIDLY ADVANCES TOWARD THE REGION. WILL SEE HIGH CLOUDS
SPILL IN DURING THE EVENING BUT REMAINING VFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 3 AM TO 6 PM CST SATURDAY FOR
WIZ032-033-041-053>055-061.
MN...WINTER WEATHER ADVISORY FROM 3 AM TO 6 PM CST SATURDAY FOR
MNZ079-086>088-094>096.
WIND CHILL ADVISORY UNTIL 11 AM CST THIS MORNING FOR MNZ086-087-
094-095.
IA...WINTER WEATHER ADVISORY FROM 3 AM TO 6 PM CST SATURDAY FOR
IAZ008>011-018-019-029-030.
WIND CHILL ADVISORY UNTIL 11 AM CST THIS MORNING FOR IAZ008>010-
018-019-029.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1106 PM CST THU JAN 16 2014
.UPDATE...
ISSUED AT 834 PM CST THU JAN 16 2014
LATEST OBSERVATIONS NO LONGER SHOW ANY BLOWING SNOW OCCURRING
ACROSS THE AREA AND A CHECK WITH LAW ENFORCEMENT INDICATES THE
COUNTIES ARE NO LONGER HAVING ANY PROBLEMS. ANOTHER QUICK MOVING
BAND OF SNOW IS EXPECTED TO MOVE ACROSS THE WESTERN SECTIONS OF
THE FORECAST AREA LATE THIS EVENING. THIS WILL BRIEFLY DROP THE
VISIBILITY BUT ACCUMULATIONS WILL BE VERY MINOR...MAYBE A HALF
INCH AT MOST. OVERALL...NOT EXPECTING THIS NEXT ROUND OF SNOW TO
HAVE MUCH IMPACT AND IN COORDINATION WITH SURROUNDING OFFICES HAVE
DROPPED THE WINTER WEATHER ADVISORY. NO CHANGES TO THE WIND CHILL
ADVISORY WITH SOME PARTS OF THE AREA EXPECTED TO FALL BELOW 20
BELOW LATE TONIGHT INTO FRIDAY MORNING.
&&
.SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)
ISSUED AT 315 PM CST THU JAN 16 2014
MAIN FORECAST CONCERNS THIS PACKAGE...WINDS/BLOWING SNOW THIS
EVENING...WIND CHILLS LATER TONIGHT/FRI MORNING...NEXT SYSTEM
DROPPING INTO THE REGION FRI NIGHT...
18Z DATA ANALYSIS HAD A 995MB LOW CENTERED OVER THE U.P. OF MI WITH
ITS BROAD CIRCULATION COVERING MUCH OF THE NORTH-CENTRAL CONUS.
TIGHTER GRADIENT AND SUBSIDENCE BEHIND A COLD FRONT MOVING ACROSS
WI/EASTERN IA WAS PRODUCING STRONG/GUSTY NORTHWEST WINDS ACROSS MUCH
OF MN/IA/WESTERN WI. SNOW ACROSS THE AREA HAS GENERALLY BEEN
SHOWERY/SPOTTY WITH MINIMAL ACCUMULATIONS...WITH ONLY A 2 TO 3 HR
PERIOD OF VSBYS BELOW A COUPLE MILES IN SNOW/BLOWING SNOW WITH THE
STRONGEST WINDS RIGHT BEHIND THE FRONT. MORE SEVERE BLOWING
SNOW/POOR VSBYS WERE OVER WESTERN MN/FAR EASTERN ND WHERE SNOW
DEPTHS WERE GREATER AND WINDS WERE STILL GUSTING 30-40 MPH.
16.12Z MODELS INITIALIZED WELL AND OFFER VERY SIMILAR SOLUTIONS FOR
TONIGHT THRU FRI NIGHT. MODEL CONSENSUS CONTINUES TO FAVOR STRONGER
OF EARLIER MODEL RUNS WITH WITH THE SHORTWAVE TROUGH TO PASS TONIGHT
AND THE NEXT ONE DROPPING TOWARD THE AREA FRI NIGHT. WITH THE
STRONGER TREND IS A SLOWING TREND WITH THE FEATURES...ESPECIALLY THE
SHORTWAVE APPROACHING FRI NIGHT. CHECK AT 18Z SHOWED MOST MODELS TO
BE A BIT FAST WITH THE COLD FRONT MOVING ACROSS WI/EASTERN IA. ALL
TO HAVE A GOOD HANDLE ON THE SFC LOW AND WINDS ACROSS REGION...AND
WERE QUITE GOOD WITH ANY SNOW ACROSS MUCH OF MN/IA/WI THIS MORNING
REMAINING ON THE LIGHT SIDE. PER WV IMAGERY MODELS LOOK GOOD WITH
THE SHORTWAVE MOVING ONSHORE IN SOUTHERN AK...WHICH DROPS INTO THE
REGION FRI NIGHT. GIVEN THE TIGHT MODEL CONSENSUS...EVEN WITH THE
STRONGER TREND...FCST CONFIDENCE IS GOOD TONIGHT THRU FRI NIGHT.
IN THE SHORT TERM...ONE MORE STRONGER LOBE/SPOKE OF VORTICITY TO
DROP ACROSS THE AREA TONIGHT. AFTER A DECREASE OF CLOUDS AND SOME
SUNSHINE FOR PARTS OF THE FCST AREA TODAY...ANOTHER DEEPER BAND OF
925-700MB MOISTURE TO ROTATE SOUTH ACROSS THE FCST AREA TONIGHT
WITH/BEHIND THE SFC-700MB TROUGH. THIS WITH SOME WEAK CONVERGENCE/
LIFT LOOKS TO PRODUCE A WEAK DEFORMATION BAND OF -SN/-SHSN AS IT
PASSES TONIGHT. CONTINUED THE 40-60 PERCENT PRECIP CHANCES WITH
SCT/ OCCASIONAL -SHSN TONIGHT. NORTHWEST WINDS REMAIN BRISK
TONIGHT BUT DO GRADUALLY DIMINISH. BLOWING/DRIFTING SNOW TO
DIMINISH/END AS WELL AS WINDS DROP 5 TO 10 KTS FROM THEIR PEAK
VALUES AND GUSTINESS WANES. WILL END THE WINTER WEATHER ADVISORY
AT MIDNIGHT AND CONVERT THE 06Z-18Z PORTION TO A WIND CHILL
ADVISORY FOR 06Z-17Z. TEMPS FALLING TO AROUND ZERO LATER TONIGHT
COUPLED WITH THE 10-20 MPH WINDS STILL LOOK TO SEND WIND CHILLS
ACROSS THE WEST THIRD OF THE FCST AREA INTO THE -20 TO -30 RANGE
LATE TONIGHT/FRI MORNING.
FRI/FRI EVENING CONTINUE TO LOOK QUIET/COLD AS SFC-700MB RIDGING
BUILDS INTO/ACROSS THE AREA. 925MB TEMPS IN THE -12C TO -16C RANGE
THRU FRI FOR HIGHS SOME 15-20F COLDER THAN THOSE OF TODAY.
SLOWER MODEL SOLUTIONS DELAY THE ARRIVAL OF THE DEEPER MOISTURE/LIFT
WITH THE NEXT STRONG SHORTWAVE TO DIVE SOUTHEAST INTO THE REGION.
RATHER IMPRESSIVE 500-300MB PV ADVECTION/LIFT/DIVERGENCE ALOFT TO
SPREAD INTO THE AREA LATER FRI NIGHT. ANOTHER ROUND OF MDT TO STRONG
925-700MB WARM ADVECTION/ISENTROPIC LIFT SPREADS ACROSS THE AREA
AHEAD OF A RATHER VIGOROUS SFC-700MB LOW DROPPING TOWARD THE AREA.
DELAYED THE ARRIVAL OF THE SNOW A BIT FRI NIGHT...LEFT FRI EVENING
DRY...THEN TRENDED SNOW CHANCES UPWARD IN THE 09-12Z SAT PERIOD.
USED A BLEND OF THE GUIDANCE LOWS/HIGHS FOR TONIGHT THRU FRI NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 PM CST THU JAN 16 2014
FORECAST CONCERNS FOR SATURDAY THROUGH SUNDAY NIGHT...SNOW ON
SATURDAY...TEMPERATURES SATURDAY THRU SUN NIGHT.
16.12Z MODELS IN GOOD AGREEMENT WITH STRONGER TRENDING SHORTWAVE TO
DROP ACROSS THE UPPER MIDWEST SAT...HGTS TO SLOWLY RISE SAT NIGHT/
SUN THEN FALL AGAIN SUN NIGHT AS THE NEXT BROADER TROUGHING/ENERGY
DROP INTO THE UPPER MIDWEST. TREND IS TOWARD A TIGHTER COMPROMISE
CONSENSUS OF THE EARLIER RUNS THRU THE PERIOD...BUT THE STRONGER/
SLOWER TREND FROM FRI NIGHT CONTINUES SAT...AND TREND IS A BIT
STRONGER WITH THE TROUGHING MOVING IN SUN NIGHT. FCST CONFIDENCE IN
THE SAT THRU SUN NIGHT PERIOD IS GOOD.
COMING OUT OF FRI NIGHT WITH THE SLIGHT SLOWING...THE STRONGEST/
DEEPEST LIFT WITH THE SHORTWAVE AND LOWER LEVEL THERMO-DYNAMIC
FORCING NOW PROGGED TO MOVE ACROSS THE FCST SAT MORNING. MODEL
CONSENSUS OF THE SWATH OF SNOW HAS TIGHTENED...BUT CAN-GEM REMAINS A
BIT WEST OF THE MEAN AND NAM A BIT EAST OF THE MEAN. EITHER
WAY...MODEL CONSENSUS PRODUCES A BAND OF 0.1 TO AS MUCH AS 0.25
INCH OF QPF ACROSS THE AREA...MAINLY ALONG/EAST OF THE MS RIVER.
SNOW-WATER RATIOS A BIT TRICKY. DENDRITIC GROWTH ZONE NOT
EXCEPTIONALLY DEEP WITH THIS SYSTEM...BUT THE LIFT IS PROGGED TO
BE STRONG AND DEEP. USING A 15 TO 17 TO 1 SNOW-WATER RATIO STILL
PRODUCES AS MUCH AS 3 TO 4 INCHES OF SNOW ALONG/NORTHEAST OF I-94
FROM LATE FRI NIGHT INTO SAT AFTERNOON. WILL HOLD OF ON ANY
HEADLINES FOR THIS EXPECTED SNOW FALL AND GIVE MID CREW ONE MORE
SET OF MODEL RUNS TO TIGHTEN THE CONSENSUS EVEN FURTHER...PLUS THE
SHORTWAVE OF CONCERN WILL BE OVER AK/NORTHWEST CAN.
BEYOND SAT...WEATHER GENERALLY QUIET FOR SAT NIGHT THRU SUN NIGHT AS
THE SAT TROUGH ROTATES QUICKLY EAST AND THE FLOW ALOFT GRADUALLY
TURNS FROM NORTH TO WEST OVER THE AREA. COLD ADVECTION BEHIND THE
SAT SHORTWAVE IS SHORT-LIVED WITH MDT/STRONG 925-700MB WARM
ADVECTION SPREADING ACROSS THE AREA SAT NIGHT/EARLY SUNDAY. SOME
DIFFERENCE OF OPINION AMONG THE MODELS HOW MUCH LOWER LEVEL WARMING
OCCURS BY SUN AFTERNOON...925MB TEMPS PER THE ECMWF/NAM IN THE -3C
TO +3C RANGE WHILE GFS IN THE -5C TO -10C RANGE. WITH MORE WESTERLY
MID LEVEL FLOW AHEAD OF SHORTWAVE ENERGY DROPPING INTO ND/NORTHERN MN
SUN AFTERNOON...WARMER NAM/ECMWF SOLUTIONS LOOK BETTER FOR SUN AND
LEFT SUNDAY HIGHS IN THE 30S. IF WARMER ECMWF IS MORE CORRECT...
COULD EVEN BE A FEW LOW 40S ON SUN...MUCH LIKE SUNDAY JAN 12. MORE
CONSISTENT SIGNAL FOR LOW LEVEL COLD ADVECTION TO RETURN SUN NIGHT
AS LOW PRESSURE TRACKING ACROSS SOUTHERN CAN PUSHES ANOTHER COLD
FRONT SOUTH ACROSS THE UPPER MIDWEST. FAVORED WARMER OF NUMERICAL
GUIDANCE FOR SUN HIGHS...OTHERWISE STAYED WITH A MODEL/ENSEMBLE
CONSENSUS FOR HIGHS/LOWS IN THE SAT-SUN NIGHT PERIOD.
FOR MONDAY THROUGH THURSDAY.../DAYS 4 TO 7/...
16.00Z AND 16.12Z MEDIUM RANGE MODELS OFFER IMPROVING AGREEMENT IN
THE MONDAY TIME-FRAME AS HGTS FALL ACROSS THE REGION...THEN REMAIN
IN GOOD/IMPROVING AGREEMENT TUE/WED AS LONGWAVE TROUGHING DEEPENS
OVER EASTERN NOAM. DETAIL DIFFERENCES ON SHORTWAVES THRU THE NORTH-
WEST TO NORTH FLOW OVER THE REGION BECOME MORE APPARENT BY THU BUT
THIS MORE OR LESS EXPECTED IN NORTHWEST FLOW BY DAY 7. WITH THE
IMPROVING CONSISTENCY...FCST CONFIDENCE FOR TEMPS HEADING BACK BELOW
NORMAL IN THE DAY 4-7 PERIOD IS GOOD. LESSER CONFIDENCE ON ANY -SN
CHANCES MON-THU WITH PLENTY OF SMALLER SCALE SHORTWAVE STRENGTH/
TIMING DETAIL DIFFERENCES AMONG THE MODELS.
TRAIN OF SHORTWAVE ENERGY DROPS ACROSS THE REGION MON...LOWERING
HGTS AND EVENTUALLY CARVING OUT THE EASTERN NOAM TROUGH FOR MUCH
OF NEXT WEEK. REGION ENDS UP UNDER NORTHWEST TO NORTH FLOW ALOFT
MUCH OF NEXT WEEK. LEAD ENERGY MON BRINGS WITH IT A -SN CHANCE FOR
MUCH OF THE FCST AREA...BUT MORE OF AN IMPACT LOOKS TO BE THE
STRONG LOW LEVEL COLD ADVECTION MON/MON NIGHT WITH 925MB TEMPS IN
THE -18C TO -22C RANGE BY 12Z TUE. AFTER A WARMER DAY SUN...TEMPS
TO SHARPLY FALL MON/MON NIGHT...ENDING UP BELOW ZERO BY TUE
MORNING WITH POTENTIAL NEED FOR WIND CHILL HEADLINES ACROSS MOST
OR ALL OF THE AREA LATE MON NIGHT/TUE MORNING. 925MB TEMPS LOOK TO
STAY IN THE - 18C TO -22C RANGE THRU WED...WITH SOME MODEL SIGNAL
FOR A STRONGER ROUND OF LOWER LEVEL WARM ADVECTION TO SPREAD
ACROSS THE AREA THU. GIVEN THE STRENGTH/DEPTH OF THE MOISTURE/LIFT
SIGNAL...SOME MODERATE OF TEMPS AND AT LEAST A SMALL -SN CHANCE
ARE REASONABLE FOR THU. TRENDED TOWARD FALLING TEMPS
MONDAY...COLDER OF LOWS/HIGHS MON NIGHT THRU WED...WITH THE
MODEL/ENSEMBLE CONSENSUS TEMPS LOOKING GOOD FOR WED NIGHT/THU.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1106 PM CST THU JAN 16 2014
THE 17.00Z NAM AND 17.01Z HRRR CONTINUE TO SUGGEST THE
POSSIBILITY OF ANOTHER SNOW BAND MOVING ACROSS THE AREA
OVERNIGHT. THIS WOULD BE IN RESPONSE TO THE SHORT WAVE TROUGH OVER
NORTHWEST WISCONSIN AS IT MOVES SOUTHEAST AND PRODUCES SOME WEAK
QG CONVERGENCE OVER THE AREA. REGIONAL RADARS AND SURFACE
OBSERVATIONS DO SHOW SOME SNOW WITH THE WAVE SO HAVE CONTINUED THE
TREND OF BRINGING THIS INTO KLSE OVERNIGHT WITH MVFR CONDITIONS.
THE MODELS HAVE CUT BACK ON THE WESTERN EXTENT OF THE SNOW WHICH
SEEMS TO FIT THE CURRENT ACTIVITY AND HAVE BACKED OFF TO JUST
FLURRIES FOR KRST WITH A LOWERING OF THE CEILING. EXPECT THE SNOW
TO QUICKLY MOVE OUT FRIDAY MORNING WITH A RETURN TO VFR CONDITIONS
AND THEN THE CLOUDS SHOULD SCATTER OUT DURING THE LATE MORNING OR
EARLY AFTERNOON AS A HIGH PRESSURE RIDGE BUILDS IN. THIS RIDGE
WILL GET PUSHED SOUTH OF THE AREA FRIDAY EVENING AS THE NEXT
SYSTEM RAPIDLY ADVANCES TOWARD THE REGION. WILL SEE HIGH CLOUDS
SPILL IN DURING THE EVENING BUT REMAINING VFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...WIND CHILL ADVISORY UNTIL 11 AM CST FRIDAY FOR MNZ086-087-094-
095.
IA...WIND CHILL ADVISORY UNTIL 11 AM CST FRIDAY FOR IAZ008>010-018-
019-029.
&&
$$
UPDATE...04
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...04
AREA FORECAST DISCUSSION
NWS ALBANY NY
916 AM EST FRI JAN 17 2014
.SYNOPSIS...
CLOUDS WILL INCREASE TODAY...AS ANOTHER FAST MOVING
CLIPPER STORM APPROACHES FROM THE GREAT LAKES AND OHIO VALLEY
REGION. THIS SYSTEM WILL MOVE ACROSS OUR REGION LATE TONIGHT INTO
SATURDAY WITH A PERIOD SNOW FOR MUCH OF THE AREA. ADDITIONAL FAST
MOVING STORM SYSTEMS WILL MOVE ACROSS THE REGION SUNDAY INTO NEXT
WEEK...EACH BRINGING A CHANCE OF SNOW SHOWERS ALONG WITH MUCH COLDER
AIR ARRIVING NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 916 AM EST...AN AREA OF LOW PRESSURE IS LIFTING FROM THE
GREAT LAKES TOWARDS SOUTHERN CANADA. A SURFACE TROUGH ATTACHED TO
THIS LOW PRESSURE AREA IS ALLOWING FOR SOME LIGHT SNOW SHOWERS
ACROSS THE ADIRONDACKS THIS MORNING. THE NEW 12Z NAM12 AND LATEST
12Z 3KM HRRR ALL SHOW LIGHT PRECIP LIFTING NORTH OVER THE NEXT FEW
HOURS AND ENDING BY NOON ACROSS THAT AREA. ELSEWHERE...IT WILL BE
DRY...ALTHOUGH PLENTY OF CLOUD COVER LOOKS TO REMAIN IN PLACE
THROUGH MUCH OF THE MORNING HOURS...ALTHOUGH SOME BREAKS ARE
ALREADY STARTING TO OCCUR ACROSS NW CT AND SW MASS.
SOME MORE BREAKS IN SUN MAY OCCUR BY AFTN FOR THE HUDSON VALLEY
AND INTO SOUTHERN VT. OTHERWISE...SKIES WILL GENERALLY BE MOSTLY
CLOUDY ACROSS THE REGION AS A SFC COLD FRONT BEGINS TO APPROACH
FROM THE GREAT LAKES REGION.
NEUTRAL TEMPERATURE ADVECTION WILL STILL RESULT IN RATHER MILD
READINGS TODAY. EXPECTING MAX TEMPERATURES MAINLY IN UPPER 30S TO
LOWER 40S IN MOST VALLEY LOCATIONS WITH LOWER TO MID 30S OVER THE
HIGHER TERRAIN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
TRANQUIL WEATHER IS EXPECTED TO START THE NIGHT...HOWEVER A COMPACT
BUT VIGOROUS SHORT WAVE TROUGH AND VORT MAX WILL BE RAPIDLY
APPROACHING FROM THE OHIO VALLEY AND WILL SPAWN A WEAK SURFACE LOW
OVER OUR AREA ON SATURDAY. IT WILL BE MOSTLY CLOUDY TONIGHT WITH LOW
TEMPERATURES WELL ABOVE NORMAL.
LARGE SCALE ASCENT AHEAD OF THE THIS SYSTEM LOOKS TO BE RATHER
SUBSTANTIAL...ALTHOUGH IT WILL BE FAST-MOVING. SNOW SHOULD DEVELOP
SOUTH AND WEST OF THE CAPITAL REGION SHORTLY BEFORE DAYBREAK
SATURDAY...SPREADING NORTHEASTWARD ACROSS THE REST OF THE AREA
DURING THE MORNING AND EARLY AFTERNOON. MODELS IN GENERALLY GOOD
AGREEMENT WITH THIS SYSTEM...ALTHOUGH SOME OF THE SUBTLE FEATURES
SUCH AS AREAS OF HIGHEST QPF ARE SLIGHTLY DIFFERENT. BASED ON
OPERATIONAL MODELS AND ENSEMBLE SPREAD...WE ARE GENERALLY EXPECTING
BETWEEN ONE AND TWO TENTHS OF QPF. SNOW RATIOS GREATEST OVER THE
HIGHER TERRAIN AROUND 12 OR 13 TO 1...WITH LOWER THAN CLIMATOLOGY
VALUES EXPECTED IN THE VALLEYS AROUND 10 OR 11 TO 1 DUE TO
RELATIVELY WARM TEMP PROFILE. THIS RESULTS IN FORECAST SNOWFALL OF
MAINLY 1-3 INCHES ACROSS THE AREA...AGAIN WITH THE GREATER AMOUNTS
IN THE HIGHER TERRAIN. THERE COULD BE SOME LOCALLY HIGHER AMOUNTS
WHERE ANY MESOSCALE BANDS OR BANDLETS SET UP...AS THERE MAY BE
ENOUGH FRONTOGENESIS TO BRIEFLY PRODUCE BANDING. AT TIMES WHEN
PRECIP IS LIGHTER...SOME RAIN MAY EVEN MIX IN AT VALLEY FLOORS BUT
THE MAJORITY SHOULD FALL AS SNOW.
THE SYSTEM QUICKLY EXITS INTO NEW ENGLAND BY LATE SATURDAY
AFTERNOON OR EARLY EVENING...ALTHOUGH THERE COULD STILL BE SOME
WRAP-AROUND SNOW SHOWERS LINGERING INTO THE EVENING ESPECIALLY
ACROSS THE HIGHER TERRAIN AREAS. WE SHOULD THEN GET A BRIEF DRY
PERIOD SATURDAY NIGHT...AS A SMALL-SCALE SURFACE RIDGE BUILDS INTO
THE AREA. THE NEXT SYSTEM WILL ALREADY BY ON OUR DOORSTEP EARLY
SUNDAY...AS ANOTHER FAST-MOVING SHORT WAVE TROUGH APPROACHES FROM
THE WEST. THIS SHOULD RESULT IN ADDITIONAL SNOW SHOWER
ACTIVITY...WITH SOME MINOR ACCUMULATIONS POSSIBLE. BEST CHANCE
WILL BE OVER THE HIGHER TERRAIN NORTH AND WEST OF ALBANY. THERMAL
PROFILE IS COOLER COMPARED TO SATURDAY...SO MAX TEMPS WILL BE
CLOSER TO NORMAL FOR MID JANUARY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AFTER THE ARCTIC COLD FRONT MOVES THROUGH THE REGION SUNDAY NIGHT OR
EARLY MONDAY MORNING...ACCOMPANIED BY SCT SNOW SHOWERS AND POSSIBLY
SOME SNOW SQUALLS...EXPECT MAINLY DRY AND BITTERLY COLD CONDITIONS
MONDAY NIGHT THROUGH THURSDAY. MODELS GENERALLY KEEP ANY SURFACE OR
UPPER LEVEL TROFS TO THE SOUTH OF THE REGION AS THEY ROTATE AROUND
THE MAIN LONG WAVE TROF OVER THE EASTERN UNITED STATES. IN
ADDITION...THE LOW LEVEL FLOW WILL BE TOO NORTHERLY FOR ANY LAKE
ENHANCEMENT IN THE ALBANY FORECAST AREA.
THE MAIN WEATHER ISSUE DURING THIS PERIOD WILL BE THE COLD. BY
MONDAY NIGHT WIND CHILL VALUES COULD REACH ADVISORY LEVELS IN THE
ADIRONDACK ZONES...THEN ACROSS MOST OF THE FORECAST AREA DURING THE
REST OF THE WEEK. COLDEST TEMPS AND WIND CHILLS WILL BE WEDNESDAY
INTO THURSDAY AND THE AVERAGE FORECAST TEMPS FOR ALBANY DO LOWER TO
10 DEGREES F STARTING ON WEDNESDAY. TOO EARLY TO INITIATE ANY ACTION
WITH THE EMERGENCY MANAGERS AT THIS TIME...BUT WILL HIGHLIGHT THE
COLD IN THE HWOALY PRODUCT.
AS THE FRONT MOVES THROUGH SUNDAY NIGHT...TEMPS WILL VARY WIDELY
FROM NORTH TO SOUTH...WITH LOWS IN THE ADIRONDACKS IN THE SINGLE
DIGITS...BUT AROUND 20 OVER SOUTHERN AREAS. HIGHS MONDAY WILL BE IN
THE TEENS AND 20S...THEN TEMPS NOSEDIVE. LOWS MONDAY NIGHT WILL BE
IN THE ZERO TO 10 BELOW RANGE OVER THE ADIRONDACKS...AND THE SINGLE
DIGITS TO LOW TEENS ELSEWHERE. HIGHS TUESDAY WILL BE IN THE SINGLE
DIGITS AND TEENS. LOWS TUESDAY AND WEDNESDAY NIGHTS WILL BE 5 BELOW
TO 15 BELOW ZERO IN THE ADIRONDACKS...AND 5 BELOW TO AROUND 5 ABOVE
ELSEWHERE. HIGHS WEDNESDAY WILL BE IN THE SINGLE DIGITS AND
TEENS...AND SOME PLACES IN THE ADIRONDACKS MAY NEVER GET ABOVE ZERO.
ON THURSDAY HIGHS WILL BE 5 ABOVE TO AROUND 20.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
EXCEPT FOR LEFTOVER MVFR/IFR CIGS/VSBYS AT THE KGFL/KPOU/KALB/KPSF
TAF SITES DUE TO FOG AND LOW CLOUDS THROUGH 13Z/14Z...EXPECT VFR
CONDITIONS AT THE TAF SITES THROUGH THE END OF THE TAF PERIOD AT 12Z
SATURDAY. MOISTURE TO THE WEST OF THE HUDSON VALLEY WILL MOVE OVER
THE REGION LATER THIS MORNING...BUT THE CLOUDS ASSOCIATED WITH THIS
MOISTURE ARE GENERALLY IN THE 5000 TO 8000 FOOT RANGE. THIS EVENING
THESE CLOUDS WILL BECOME SCT...BUT THEN CLOUDS WILL INCREASE AGAIN
LATE TONIGHT AS THE NEXT WEAK LOW PRESSURE AREA MOVES NORTHEAST
THROUGH PENNSYLVANIA.
WINDS WILL GENERALLY BE CALM OR LIGHT AND VARIABLE EARLY THIS
MORNING...BUT AS THE SURFACE HIGH SHIFTS TO THE EAST...A SOUTHERLY
FLOW OF AIR WILL TAKE CONTROL AND EXPECT SOUTHERLY WINDS AT THE TAF
SITES AT LESS THAN 10 MPH FOR THE REST OF THE DAY. AFTER SUNSET...
WINDS WILL BECOME LIGHT AND VARIABLE.
OUTLOOK...
SATURDAY: HIGH OPERATIONAL IMPACT. LIKELY SN.
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. SLIGHT CHANCE OF
SHSN.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
SUNDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. SLIGHT CHANCE OF SHSN.
MARTIN LUTHER KING JR DAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF
SHSN.
MONDAY NIGHT TO TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.HYDROLOGY...
RIVER AND STREAM LEVELS REMAIN SOMEWHAT ELEVATED DUE TO THE RECENT
RAINFALL AND SNOW MELT...BUT HAVE BEEN RECEDING FOR THE PAST COUPLE
DAYS. THROUGH EARLY NEXT WEEK...ONLY LIGHT PRECIPITATION IN THE FORM
OF SNOW IS EXPECTED ACROSS OUR AREA. THIS PRECIP WILL HAVE LITTLE
EFFECT ON AREA RIVERS AND STREAMS. AS A RESULT...STREAM FLOWS SHOULD
GRADUALLY LOWER. WITH COLD TEMPERATURES RETURNING OVER THE WEEKEND
AND ESPECIALLY NEXT WEEK...RIVER AND LAKE ICE WILL BEGIN TO REFORM
AND STRENGTHEN.
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.
&&
.EQUIPMENT...
THE COMMUNICATIONS ISSUES WITH THE KENX WSR-88D HAVE BEEN
RESOLVED AND THE RADAR IS BACK IN SERVICE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/JPV
NEAR TERM...FRUGIS/JPV
SHORT TERM...JPV
LONG TERM...GJM
AVIATION...GJM
HYDROLOGY...FRUGIS/JPV
EQUIPMENT...FRUGIS
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
806 AM EST FRI JAN 17 2014
.SYNOPSIS...
ISSUED AT 804 AM EST FRI JAN 17 2014
AN UPPER LEVEL DISTURBANCE WILL TRACK ACROSS THE GREAT LAKES
REGION LATE THIS AFTERNOON AND EVENING BRINGING SCATTERED SNOW
SHOWERS TO THE AREA. MUCH COLDER AIR WILL MOVE IN TODAY WITH
TEMPERATURES FALLING BACK INTO THE MID TO UPPER TEENS.
ANOTHER STRONG UPPER LEVEL DISTURBANCE WILL CROSS THE REGION
SATURDAY AFTERNOON AND EVENING...BRINGING A GOOD CHANCE OF ACCUMULATING
SNOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM EST FRI JAN 17 2014
SECONDARY SW DISTURBANCE OVR NE MO EARLY THIS MORNING WILL PIVOT EWD
THROUGH BASE OF LW TROUGH EXTENDING SWD OUT OF HUDSON BAY AND INTO
CNTRL OH BY EVENING. SUSPECT -SHSN WILL BLOSSOM ONCE AGAIN
DOWNSTREAM AFT SUNRISE GENERALLY SOUTH OF THE 24 CORRIDOR FOLLOWING
DEEPER COLD POCKET ALOFT AND INTO NW OH THIS AFTN. OTRWS XPC LK
ACTIVATION WILL HAVE TO WAIT UNTIL LT THIS AFTN TIMED W/PASSAGE OF
ADDNL MID LVL TROUGH BACK NW ACRS CNTRL WI THIS MORNING AS LL FLW
VEERS NWRLY. HWVR W/MOST INTENSE LL THERMAL TROUGHING PASSING WELL
SOUTH THROUGH SRN FLANK OF MO DISTURBANCE...DOUBT IT WILL
AMT TO MUCH OVERNIGHT. HIGHS EARLY W/STEADY TO SLOWLY FALLING
TEMPS THROUGH THIS AFTN AS CAA WEDGE DEEPENS ACRS THE AREA.
&&
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 334 AM EST FRI JAN 17 2014
AMPLIFIED POSITIVE PNA PATTERN WILL PERSIST THROUGH THE PERIOD WITH
BROAD EASTERN CONUS LONGWAVE TROUGH LOCKED IN DOWNSTREAM OF AN
IMPRESSIVE WEST COAST/ALASKA RIDGE. THIS WILL KEEP THE LOCAL AREA IN
AN ACTIVE/COLD NORTHWEST FLOW REGIME.
PRIMARY UPPER PV ANOMALY OF INTEREST...NEARING THE ALBERTA/NORTHWEST
TERRITORIES AS OF THIS WRITING...IS STILL MODELED TO DROP QUICKLY
SOUTHEAST ON THE NOSE OF A 130-140 UPPER JET AND IMPACT THE IWX CWA
SATURDAY AFTERNOON INTO SATURDAY EVENING. AS EXPECTED MODELS
CONTINUE TO BOUNCE AROUND SOME ON TRACK/INTENSITY/TIMING...WITH THE
OVERALL TREND IN 00Z GUIDANCE TO SHIFT A BIT SOUTH/SOUTHWEST AND
WEAKER WITH WAVE. HARD TO TAKE THIS TREND AND ONE MODEL CYCLE TOO
SERIOUS WITH WAVE IN FAR NORTHWEST CANADA AT 00Z. AS A RESULT MADE
ONLY MINOR TWEAKS TO THE GRIDS FAVORING A GFS/ECMWF SFC LOW TRACK
SOUTHEAST THROUGH CENTRAL ILLINOIS/INDIANA. SHOULD BE A NARROW BAND
OF ACCUMULATION SNOW (2-5") JUST NORTH-NORTHEAST OF THIS LOW TRACK
WITH CONFIDENCE ON WHERE EXACTLY THIS SWATH OF HEAVIER SNOW FALLS
SOMEWHAT LOW GIVEN LINGERING MODEL SPREAD. ATTM IT LOOKS LIKE BEST
CHANCES FOR A PLOWABLE SNOW ARE ACROSS WESTERN/SOUTHERN PORTIONS OF
THE FA. LOWER PROBABILITY EXISTS FOR SOME HEAVIER RATES/TOTALS NEAR
6 INCHES AS SOME GUIDANCE STILL SHOWS A CLOSED MID LVL CIRCULATION,
STEEP MID LVL LAPSE RATES, AND GOOD SNOW GROWTH WITH 850-700 MB
TEMPS AVERAGING IN FAVORABLE -10C TO -20C RANGE...WITH MOISTURE AND
QUICK MOVEMENT LIMITING FACTORS.
BREEZY, DRY, AND SLIGHTLY WARMER FOR THE SECOND HALF OF THE WEEKEND
AS LOW LEVEL FLOW BRIEFLY BACKS SOUTHWEST IN ADVANCE OF AN ARCTIC
FRONT. NOT EXPECTING MUCH IN THE WAY OF SNOW WITH THIS ARTIC FRONT
THAT WILL USHER IN FRIGID TEMPERATURES (WELL BELOW NORMAL) FOR
MUCH OF NEXT WEEK. LAKE-700 MB TEMP DIFFERENTIALS IN THE MID 20S TO
LOW 30S AND POTENTIAL FOR A PROLONGED PERIOD OF NORTH-NORTHWEST
TRAJECTORIES BRINGS ABOUT CONCERNS FOR A SIGNIFICANT LAKE EFFECT
SNOW EVENT IN THE FAR NORTHWEST...MAINLY IN THE LATE MON-TUE
PERIODS. OTHERWISE...SEVERAL CHANCES FOR SYNOPTIC SNOWS AND LAKE
ENHANCEMENT WED-FRI AS SEVERAL MORE CLIPPER SYSTEMS DROP THROUGH.
&&
.AVIATION/UPDATE...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 622 AM EST FRI JAN 17 2014
COMPLICATED PATTN THIS MORNING OVERHEAD W/MULTIPLE DISTURBANCES
EMBEDDED WITHIN LARGER SCALE LW TROUGH EXTENDING SWD FM HUDSON BAY.
MOST VIGOROUS FTR OF NOTE IS CLOSED LOW MIGRATING EWD THROUGH CNTRL
IL W/BLOSSOMING AREA OF CONV SNOW SHOWERS DVLPG IN EARNEST ACRS SRN
IN/WRN KY. THIS LEADS TO SOME CONCERN AS SEEN IN RECENT RUC WWD
TRENDS TAKING SNOW INTO ERN NW OHIO COUNTIES FM LTR MORNING INTO MID
AFTN. HAVE BUMPED EXTREME ERN COUNTIES TO ACCOUNT FOR THIS BUT VAPOR
IMAGERY SUGGESTS SOME FURTHER WWD EXPANSION PSBL.
TERMINALS A BIT MORE STRAIGHT FWD EARLY ON BUT TURN COMPLICATED BY
LT AFTN INADV OF TERTIARY DISTURBANCE WRAPPING UP NRN WI ATTM. ALL
GUIDANCE PROGS THIS FTR TO WKN YET BELIEVE A PD OF DIURNALLY
ENHANCED -SHSN MAY OCCUR THIS AFTN ESP NW HALF. OTRWS WIDESPREAD
MVFR CIGS FILLING UP WWD/SWWD WITHIN CAA WEDGE AND XPC THIS WILL
OVERSPREAD ACRS THE TERMINALS THROUGH SUNRISE.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR LMZ043-046.
&&
$$
SYNOPSIS...KG
SHORT TERM...T
LONG TERM...STEINWEDEL
AVIATION...T
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
624 AM EST FRI JAN 17 2014
.SYNOPSIS...
ISSUED AT 1248 AM EST FRI JAN 17 2014
ANOTHER IS A SERIES OF UPPER LEVEL DISTURBANCES WILL TRACK ACROSS
THE GREAT LAKES REGION LATE THIS AFTERNOON AND EVENING BRINGING
SCATTERED SNOW SHOWERS. MUCH COLDER AIR WILL OVERSPREAD THE TODAY
WITH MORNING HIGH TEMPERATURES FALLING BACK INTO THE MID TO UPPER
TEENS.
ANOTHER STRONG UPPER LEVEL DISTURBANCE WILL CROSS THE REGION
SATURDAY AFTERNOON AND EVENING...BRINGING A GOOD CHANCE OF ACCUMULATING
SNOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM EST FRI JAN 17 2014
SECONDARY SW DISTURBANCE OVR NE MO EARLY THIS MORNING WILL PIVOT EWD
THROUGH BASE OF LW TROUGH EXTENDING SWD OUT OF HUDSON BAY AND INTO
CNTRL OH BY EVENING. SUSPECT -SHSN WILL BLOSSOM ONCE AGAIN
DOWNSTREAM AFT SUNRISE GENERALLY SOUTH OF THE 24 CORRIDOR FOLLOWING
DEEPER COLD POCKET ALOFT AND INTO NW OH THIS AFTN. OTRWS XPC LK
ACTIVATION WILL HAVE TO WAIT UNTIL LT THIS AFTN TIMED W/PASSAGE OF
ADDNL MID LVL TROUGH BACK NW ACRS CNTRL WI THIS MORNING AS LL FLW
VEERS NWRLY. HWVR W/MOST INTENSE LL THERMAL TROUGHING PASSING WELL
SOUTH THROUGH SRN FLANK OF MO DISTURBANCE...DOUBT IT WILL
AMT TO MUCH OVERNIGHT. HIGHS EARLY W/STEADY TO SLOWLY FALLING
TEMPS THROUGH THIS AFTN AS CAA WEDGE DEEPENS ACRS THE AREA.
&&
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 334 AM EST FRI JAN 17 2014
AMPLIFIED POSITIVE PNA PATTERN WILL PERSIST THROUGH THE PERIOD WITH
BROAD EASTERN CONUS LONGWAVE TROUGH LOCKED IN DOWNSTREAM OF AN
IMPRESSIVE WEST COAST/ALASKA RIDGE. THIS WILL KEEP THE LOCAL AREA IN
AN ACTIVE/COLD NORTHWEST FLOW REGIME.
PRIMARY UPPER PV ANOMALY OF INTEREST...NEARING THE ALBERTA/NORTHWEST
TERRITORIES AS OF THIS WRITING...IS STILL MODELED TO DROP QUICKLY
SOUTHEAST ON THE NOSE OF A 130-140 UPPER JET AND IMPACT THE IWX CWA
SATURDAY AFTERNOON INTO SATURDAY EVENING. AS EXPECTED MODELS
CONTINUE TO BOUNCE AROUND SOME ON TRACK/INTENSITY/TIMING...WITH THE
OVERALL TREND IN 00Z GUIDANCE TO SHIFT A BIT SOUTH/SOUTHWEST AND
WEAKER WITH WAVE. HARD TO TAKE THIS TREND AND ONE MODEL CYCLE TOO
SERIOUS WITH WAVE IN FAR NORTHWEST CANADA AT 00Z. AS A RESULT MADE
ONLY MINOR TWEAKS TO THE GRIDS FAVORING A GFS/ECMWF SFC LOW TRACK
SOUTHEAST THROUGH CENTRAL ILLINOIS/INDIANA. SHOULD BE A NARROW BAND
OF ACCUMULATION SNOW (2-5") JUST NORTH-NORTHEAST OF THIS LOW TRACK
WITH CONFIDENCE ON WHERE EXACTLY THIS SWATH OF HEAVIER SNOW FALLS
SOMEWHAT LOW GIVEN LINGERING MODEL SPREAD. ATTM IT LOOKS LIKE BEST
CHANCES FOR A PLOWABLE SNOW ARE ACROSS WESTERN/SOUTHERN PORTIONS OF
THE FA. LOWER PROBABILITY EXISTS FOR SOME HEAVIER RATES/TOTALS NEAR
6 INCHES AS SOME GUIDANCE STILL SHOWS A CLOSED MID LVL CIRCULATION,
STEEP MID LVL LAPSE RATES, AND GOOD SNOW GROWTH WITH 850-700 MB
TEMPS AVERAGING IN FAVORABLE -10C TO -20C RANGE...WITH MOISTURE AND
QUICK MOVEMENT LIMITING FACTORS.
BREEZY, DRY, AND SLIGHTLY WARMER FOR THE SECOND HALF OF THE WEEKEND
AS LOW LEVEL FLOW BRIEFLY BACKS SOUTHWEST IN ADVANCE OF AN ARCTIC
FRONT. NOT EXPECTING MUCH IN THE WAY OF SNOW WITH THIS ARTIC FRONT
THAT WILL USHER IN FRIGID TEMPERATURES (WELL BELOW NORMAL) FOR
MUCH OF NEXT WEEK. LAKE-700 MB TEMP DIFFERENTIALS IN THE MID 20S TO
LOW 30S AND POTENTIAL FOR A PROLONGED PERIOD OF NORTH-NORTHWEST
TRAJECTORIES BRINGS ABOUT CONCERNS FOR A SIGNIFICANT LAKE EFFECT
SNOW EVENT IN THE FAR NORTHWEST...MAINLY IN THE LATE MON-TUE
PERIODS. OTHERWISE...SEVERAL CHANCES FOR SYNOPTIC SNOWS AND LAKE
ENHANCEMENT WED-FRI AS SEVERAL MORE CLIPPER SYSTEMS DROP THROUGH.
&&
.AVIATION/UPDATE...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 622 AM EST FRI JAN 17 2014
COMPLICATED PATTN THIS MORNING OVERHEAD W/MULTIPLE DISTURBANCES
EMBEDDED WITHIN LARGER SCALE LW TROUGH EXTENDING SWD FM HUDSON BAY.
MOST VIGOROUS FTR OF NOTE IS CLOSED LOW MIGRATING EWD THROUGH CNTRL
IL W/BLOSSOMING AREA OF CONV SNOW SHOWERS DVLPG IN EARNEST ACRS SRN
IN/WRN KY. THIS LEADS TO SOME CONCERN AS SEEN IN RECENT RUC WWD
TRENDS TAKING SNOW INTO ERN NW OHIO COUNTIES FM LTR MORNING INTO MID
AFTN. HAVE BUMPED EXTREME ERN COUNTIES TO ACCOUNT FOR THIS BUT VAPOR
IMAGERY SUGGESTS SOME FURTHER WWD EXPANSION PSBL.
TERMINALS A BIT MORE STRAIGHT FWD EARLY ON BUT TURN COMPLICATED BY
LT AFTN INADV OF TERTIARY DISTURBANCE WRAPPING UP NRN WI ATTM. ALL
GUIDANCE PROGS THIS FTR TO WKN YET BELIEVE A PD OF DIURNALLY
ENHANCED -SHSN MAY OCCUR THIS AFTN ESP NW HALF. OTRWS WIDESPREAD
MVFR CIGS FILLING UP WWD/SWWD WITHIN CAA WEDGE AND XPC THIS WILL
OVERSPREAD ACRS THE TERMINALS THROUGH SUNRISE.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR LMZ043-046.
&&
$$
SYNOPSIS...MARSILI
SHORT TERM...T
LONG TERM...STEINWEDEL
AVIATION...T
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1048 AM EST FRI JAN 17 2014
.UPDATE...
ISSUED AT 1039 AM EST FRI JAN 17 2014
SNOW SHOWERS AND SOME ISOLATED SNOW SQUALLS ARE MOVING EAST SLIGHTLY
FASTER THAN THE PREVIOUS FORECAST. WE HAVE OPTED TO GO AHEAD AND
START THE WINTER WEATHER ADVISORY ACROSS THE SOUTHEASTERN PART OF THE
AREA A BIT QUICKER AS A RESULT. SNOW ACCUMULATIONS STILL LOOK GOOD
WITH AROUND AN INCH OR SO ON AVERAGE IN MOST LOCATIONS THROUGH THIS
EVENING. LOCALLY HIGHER AMOUNTS ARE ANTICIPATED GENERALLY ABOVE 2000
FEET NEARER TO VA AND IN ANY MORE PERSISTENT BANDS OF SNOW. ALTHOUGH
THERE WAS SOME THUNDERSNOW IN THE BAND OF SNOW SHOWERS NOW ROTATING
INTO VA AND WV...THE NEXT BANDS OF SNOW SHOWERS ARE NOT AS DEEP IN
THE ATMOSPHERE... AND LIGHTNING APPEARS LESS LIKELY BUT THEY SHOULD
BE MORE WIDESPREAD. HOURLY TEMPS AND DEWPOINTS HAVE ALSO BEEN
FRESHENED UP BASED ON THE LATEST TRENDS.
UPDATE ISSUED AT 620 AM EST FRI JAN 17 2014
DID A QUICK UPDATE TO TAKE THE FIRST ROUND OF SNOW OUT OF THE GRIDS
AND FIRM UP THE TIMING OF THE NEXT BATCH. ALSO FINE TUNED THE SKY AND
NEAR TERM TEMPS/DEWPOINTS. THESE HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 350 AM EST FRI JAN 17 2014
07Z SFC ANALYSIS SHOWS THE LATEST CLIPPER SYSTEM MOVING THROUGH THE
GREAT LAKES. THIS IS PUSHING AN ARCTIC BOUNDARY INTO THE WESTERN
PORTIONS OF THE OHIO VALLEY. AHEAD OF THIS...A DISTURBANCE AT MID
LEVELS HAS SENT A NEW BATCH OF SNOW SHOWERS THROUGH EAST KENTUCKY
WHITENING SOME PLACES UP TO AN INCH AS IT PASSES. AT THE WEATHER
OFFICE WE PICKED UP A QUICK 7 TENTHS OF AN INCH AS ONE OF THOSE BANDS
MOVED THROUGH. TEMPERATURES AROUND FREEZING AND ROAD TEMPERATURES IN
MOST PLACES ABOVE FREEZING WILL LIMIT THE IMPACT FROM THESE SNOW
SHOWERS. OVER THE SOUTHERN PARTS OF THE CUMBERLAND VALLEY THE
DEWPOINTS HAVE COME UP INTO THE LOW TO MID 30S AND THIS IS LEADING TO
MORE OF A RAIN EVENT WITH THIS ROUND RATHER THAN SNOW. IT IS A FINE
LINE...THOUGH...SO WILL CONTINUE THE SPS THAT IS OUT THROUGH 16Z FOR
THAT AREA. DESPITE A FEW HEAVIER BANDS...THE BULK OF THE AREA WILL
SEE AROUND A HALF AN INCH OF ACCUMULATION OR LESS THOUGH DAWN.
SLIGHTLY BETTER TOTALS CAN BE EXPECTED ALONG AND IN THE IMMEDIATE
WAKE OF THE ARCTIC BOUNDARY LATER TODAY.
THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT AS THEY ALL SHOW A
POTENT SHORTWAVE CROSSING THROUGH THE SOUTHERN OHIO VALLEY TODAY
WITHIN THE HEART OF A DEEP TROUGH. THIS WAVE WILL BRING SOME STEEP
LAPSE RATES TO THE LOWER PART OF THE ATMOSPHERE LATER THIS MORNING
AND THROUGH THE AFTERNOON HELPING TO ENHANCE THE LIFT AND SHOWERY
NATURE OF THE SNOW. THIS FEATURE MOVES QUICKLY OFF TO THE NORTHEAST
TONIGHT AS THE LARGER TROUGH TEMPORARILY RETREATS TO THE NORTH.
ACCORDINGLY...HEIGHTS WILL MODERATE THROUGH THE AREA INTO SATURDAY
MORNING. THIS PROCESS IS THEN QUICKLY REVERSED LATER THAT DAY AS THE
NEXT SHARP WAVE DROPS SOUTHEAST THROUGH THE MIDWEST...MAKING ITS RUN
TOWARD THE OHIO VALLEY. WITH THE GENERAL MODEL AGREEMENT AND THE
MESOSCALE NATURE OF THE SNOW BANDS AND ARCTIC BOUNDARY...HAVE LEANED
TOWARD THE HIGHER RESOLUTION HRRR AND NAM12 THROUGH THE SHORT TERM.
SENSIBLE WEATHER WILL FEATURE THE PRE-DAWN SNOW...AND FAR SOUTHERN
KY RAIN...SHOWERS EXITING THE AREA WITH A BIT OF A LULL IN ANY PCPN
ACTIVITY UNTIL AROUND MID MORNING IN THE WEST WHEN THE ARCTIC
BOUNDARY MOVES INTO THE CWA. THIS WILL BRING ANOTHER ROUND OF SNOW
SHOWERS...COLDER TEMPERATURES...AND BRISK WINDS TO THE AREA TODAY.
ALTHOUGH MOISTURE IS LIMITED WITH THIS...STILL EXPECT THE LIFT ALONG
THE FRONT AND STEEP LAPSE RATES BEHIND IT TO SUPPORT SNOW SHOWERS
INTENSE ENOUGH TO ACCUMULATE FOR MOST LOCATIONS...GENERALLY A HALF TO
ONE INCH THROUGH EARLY EVENING. TWO INCHES OR MORE INCHES WILL BE
POSSIBLE IN THE HIGHEST TERRAIN NEAR THE VIRGINA BORDER THROUGH
MIDNIGHT. IN ADDITION TO THE SNOW...BRISK WINDS ACCOMPANYING THE SNOW
WILL LIMIT VISIBILITIES AT TIMES TO A MILE OR LESS...POTENTIALLY
CREATING BRIEF PERIODS OF HAZARDOUS TRAVEL. THE SNOW SHOWERS WILL
TAPER TO FLURRIES AND END FROM WEST TO EAST ON SATURDAY NIGHT WITH
TEMPERATURES PLUMMETING INTO THE TEENS BY DAWN. FOR THE BULK OF THE
DAY SATURDAY THE WX WILL BE QUIET BETWEEN DISTURBANCES. HOWEVER...BY
EVENING THICKER AND LOWER CLOUDS WILL BE ROLLING BACK IN FROM THE
NORTHWEST WITH SOME SNOW POSSIBLE BEFORE DARK IN OUR NORTHWEST
COUNTIES.
FOR THE ARCTIC BOUNDARY MOVING THROUGH THE CWA THIS MORNING AND
AFTERNOON WILL ISSUE AN EXTENSION TO THE WSW TO COVER THE ENTIRE
CWA...LINGERING IT INTO THE LATE EVENING IN THE FAR EAST. THE ONLY
DIFFERENCE FROM THE CURRENT ONE IS THAT THIS EXTENSION WILL NOT GO
INTO EFFECT UNTIL AFTER 15Z.
FOLLOWED A BLEND OF THE DIURNAL FROM NAM12 AND THE CONSSHORT FOR
HOURLY TEMPS WHILE FAVORED THE BCCONSSHORT FOR TD AND WINDS THROUGH
THE FIRST 24 HOURS...STARTING WITH THE CONSALL THEREAFTER AND FOR MAX
AND MIN TEMPS THROUGH SATURDAY. AS FOR POPS...ENDED UP HIGHER THAN
ALL GUIDANCE FOR TODAY THROUGH TONIGHT GIVEN THE LOW QPF NATURE OF
THIS EVENT.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 337 AM EST FRI JAN 17 2014
AN ACTIVE AND VERY PROGRESSIVE EXTENDED PERIOD BEGINS ON SATURDAY
NIGHT WITH A POSITIONED BROAD TROUGH OVER THE NORTHEASTERN CONUS AND
REMAINING THERE FOR THE ENTIRE EXTENDED. BEFORE DELVING INTO THE
SPECIFICS...THE MODELS DO AGREE ON A RIDGE TROUGH LONGWAVE PATTERN
THROUGH THE EXTENDED. THE TRUE FORECAST CHALLENGE FOR THIS PERIOD
FALLS ON HOW THE MODELS HANDLE THE ARRIVAL OF EACH SHORT WAVES THAT
WILL ROTATE DOWN OUT OF CANADA AND INTO THE GREAT LAKES OHIO VALLEY
REGION. THIS COUPLE WITH THE CHALLENGE OF DETERMINING THE MOISTURE
AVAILABLE...WILL BE QUITE A PROBLEM.
THIS IN MIND...WILL STAY CLOSE TO THE MODEL ALL BLEND AND ENSEMBLE
SOLUTIONS AND DECREASING PROBABILITIES WHERE CONFIDENCE IS LOW. THE
FIRST SIGNIFICANT WAVE MOVES THROUGH THE AREA ON SUNDAY. WITH THE
COLDER AIR ALREADY IN PLACE...THE PRECIP TYPE WITH THIS SYSTEM
SHOULD FALL AS SNOW AND THE INSTABILITY THE MODEL PROFILES ARE
SHOWING WOULD INDICATE AT SOME ACCUMULATING SNOWFALL POSSIBLE WITH
TEMPS COLD ENOUGH AND A GOOD SHOT OF OMEGA IN THE SATURATED -10 TO
-20 REGION FOR A GOOD 2 TO 3 HOUR PERIOD ON SUNDAY MORNING. WILL
NEED TO WATCH FOR THIS SYSTEM...ESPECIALLY WITH A FAVORABLE WIND
DIRECTION FOR SOME UP SLOPE ASSISTANCE. MODELS DO HAVE A GOOD BIT
AGREEMENT WITH THIS AND THIS WAVE IS POSSIBLY THE ONLY WAVE TO PUT
SOME CONFIDENCE IN AS AFTER THIS FEATURE MOVES THROUGH...THE MODELS
WAFFLE WITH THE CHARACTERISTICS OF THE SHORTWAVES LATER IN THE
EXTENDED.
AFTER THIS STRONG WAVE ON SUNDAY PUSHES THROUGH...A BUILDING ARCTIC
AIR MASS WILL DIVE SOUTH AS THE SEMI PERMANENT 500 TROUGH OVER THE
NORTHEAST DIGS A BIT FURTHER SOUTH INTO THE SOUTHERN APPALACHIANS.
THIS WILL BRING TEMPS INTO THE 20S FOR HIGHS AND TEENS FOR LOWS BY
TUESDAY AND THROUGH THE REST OF THE EXTENDED. THE FOLLOWING PIECES
OF ENERGY ON TUESDAY AND THURSDAY ARE QUITE WEAK AND EVEN THE EURO
IS INCONSISTENT WITH THESE WAVES AS IT WILL SHIFT THE WAVES ABOUT 1
TO 2 HUNDRED MILES TO THE EAST FROM RUN TO RUN. WITH THIS TYPE OF
INCONSISTENCY...HAVE GONE WITH SLIGHT CHANCE POPS FROM DAY 4 THROUGH
DAY 7. THE COLDER TEMPS EXPECTED THOUGH WILL ASSURE ANY PRECIP
FALLING AFTER DAY 4 WILL BE SNOW. IT IS SOMEWHAT ENCOURAGING THAT
TELECONNECTIONS AT THIS POINT SUPPORT FALLING TEMPS AFTER TUESDAY SO
THAT IS ONE PARAMETER THAT CAN BE COUNTED ON.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 635 AM EST FRI JAN 17 2014
WE ARE NOW IN A LULL BETWEEN THESE SNOW SYSTEMS. THIS WILL RESULT IN
SPOTTY MVFR CIGS FOR THE NEXT SEVERAL HOURS...BUT GOOD VIS. THE CIGS
WILL LOWER MORE PERMANENTLY WITH THE ARRIVAL OF THE NEXT BATCH OF
SNOW. THIS NEXT BATCH OF SNOW WILL LAST THROUGH THE AFTERNOON WITH AN
ACCOMPANYING ARCTIC BOUNDARY ENOUGH FOR VIS AND CIGS TO FALL BACK
DOWN TO MVFR AND BRIEFLY WORSE. THIS LATEST AREA OF SNOW WILL
GRADUALLY WANE INTO THE EVENING WITH CIGS LIKELY IMPROVING AND VIS
ABOVE 6 MILES EVEN AS A FEW FLURRIES CONTINUE OVER THE AREA. WINDS
WILL BE SOUTHWEST AT 5 TO 10 KTS WITH AN OCCASIONAL GUST TO 15 KTS
UNTIL BETWEEN 15 AND 20Z WHEN THE BOUNDARY MOVES IN AND SWITCHES THEM
TO THE WEST AT 10 TO 20 KTS FOR THE BULK OF THE DAY...DIMINISHING
BELOW 10 KTS ONLY DURING THE EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR KYZ044-
050>052-058>060-068-069-079-080-104-106-108-111-114.
WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR KYZ087-
088-110-113-115-117-118-120.
WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR
KYZ083>086-107-109-112-116-119.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
647 AM EST Fri Jan 17 2014
...Updated Aviation Discussion...
...Forecast Update...
Issued at 645 AM EST Fri Jan 17 2014
Quick update to go a bit more bullish on snow coverage this morning,
and a little quicker with the timing as it is already starting to
expand into the Bluegrass region. Still look for the accumulating
snows to diminish from west to east around midday, but some concern
based on the NAM and RAP both showing a band hanging on into the
afternoon south of the Bluegrass Parkway.
Will try to handle specific trends mainly with Graphical Nowcasts
and social media. Overall zones and WSW look in good shape.
.SHORT TERM (Now through Saturday)...
Issued at 315 AM EST Fri Jan 17 2014
...Accumulating Snow Expected This Morning...
Main near-term challenge is how best to convey the potential impact
of snow showers this morning. Scattered snow showers over southwest
Indiana and western Kentucky have been increasing in coverage over
the last couple of hours, but significant gaps remain. Still can`t
count on where those gaps will be, but the leading edge of the snow
showers should reach the I-65 corridor around 6 AM EST, just in time
for the morning commute.
By far the most bullish QPF is generated by the 06Z NAM12, which
just came in. It actually has a decent handle on the ongoing precip,
and shows it blossoming enough to drop a tenth of an inch of liquid
in the Louisville Metro between 09-12Z, and liquid precip amounts
approaching two tenths up the I-71 corridor by 15Z. Not convinced we
will actually see that over any large area, but still believe there
is strong potential for a quick half inch of snow accumulation this
morning, with local amounts up to an inch. Will keep our current
Winter Weather Advisory flying more for impact than anything else.
If anything, with the axis of the 500mb shortwave trof pushing into
the I-75 corridor by mid-afternoon, could tinker with the end time
of the advisory.
Arctic front is right on the heels of these snow showers, and will
push through the area as the morning progresses. Temps currently
hovering near freezing will quickly drop into the 20s area-wide by
midday, then remain steady or continue to slowly fall through the
afternoon. Gusty northwest winds will make it feel more like 10
above this afternoon. Temp forecast is pretty much in line with raw
model consensus, and takes us a solid 10 degrees below normal
tonight and Saturday.
Next Clipper will approach the Ohio Valley from the NNW on Saturday
afternoon. Decent warm air advection ahead of this impulse will push
temps into the upper 30s in parts of south-central and west-central
Kentucky, but if precip moves in there will be sufficient wet-bulb
effect to get it to the surface as a rain/snow mix, if not all snow.
Could see a quick half inch of snow over southern Indiana, but it
should hold off until at least Saturday evening along and south of
the Western Kentucky and Bluegrass Parkways.
.LONG TERM (Saturday Night through Thursday)...
Issued at 315 AM EST Fri Jan 17 2014
The synoptic pattern at the start of the long term period will
feature amplified upper-level flow, with a trough dominating the
eastern 2/3rds of the CONUS. This stubborn pattern that we`ve seen
for several weeks now will continue through the long term period, as
the trough continually gets reinforced by quick-hitting PV anomalies
diving through the swift flow aloft.
A strong Clipper system approaching Saturday night will be the main
focus of the long term period. The latest guidance remains split on
the track of this system. The 17/00Z NAM/GEM advertise a southern
track, with the 17/00Z GFS/ECMWF advertise a more northerly
solution. The northerly solution would mean less snow for the
region, while the southerly solution would bring more in the way of
accumulations. Dprog/dt fields show the GFS and ECMWF solutions
being quite consistent, whereas the NAM has flopped to a more
southerly solution with the latest 00Z run. The GEFS agrees very
well with its deterministic solution, putting a bit more credence
within the northerly track. Additionally, climatology shows that
these fast-moving Clipper systems tend to produce the best swath of
snow just to the NE of the surface low track, where ascent from the
left exit region of the jet streak couples with the best mid-level
forcing to produce the best region of deep lift.
That being said, the northern solution still looks as if it could
bring some light accumulations to the region. The best chances of
exceeding an inch with this event will be across the Northern
Bluegrass and portions of eastern KY. It is in these locations
where the best QPF will combine with the highest snow ratios
(perhaps 15 to 20:1) to produce accumulations of around an inch.
Elsewhere, amounts look as if they`ll be a bit lower, given lower
QPF and warmer temperatures which will lead to a lower snow ratio.
The good news is that the snow looks as if it will mostly fall
Saturday evening into the first part of the overnight hours, which
should help minimize potential travel impacts.
The system will quickly push out Sunday morning, leading to clearing
skies. Temperatures behind it won`t be all that cool, with highs
Sunday expected in the upper 30s to lower 40s.
The upper trough briefly, very briefly, breaks down on Monday, which
will allow the flow to go more zonal. This should help temperatures
finally rise to near normal for this time of year, in the upper 30s
and 40s.
The trough builds back in by Tuesday and the forecast becomes tricky
for the remainder of next week as the train of quick-hitting PV
anomalies continues. Given the wet bias of guidance with these past
events, have trended the forecast on the drier side. That being
said, there will certainly be a few chances of some light snow
through the extended period as these systems pass through, but
nothing appears all that significant at this time. One weak system
looks possible Monday night into Tuesday, with another potential one
Wednesday night into Thursday. Confidence is quite high, however,
in below normal temperatures continuing through the extended as the
trough remains fixed over the region. High temperatures will
struggle in the middle 20s through much of next week, with lows
generally in the teens. For those craving spring, it seems that
winter still has a long way to go...
&&
.AVIATION (12Z TAF Update)...
Updated at 615 AM EST Fri Jan 17 2014
Cluster of snow showers has filled in over west central Kentucky,
and is now spreading into the SDF area, with visibilities
intermittently dropping to IFR. Through mid-morning SDF will be
impacted by these snow showers, which will be heavy enough at times
to drop visibilities into LIFR and allow snow to accumulate on
aircraft and runways. By about 14Z the focus will begin to shift
over to LEX, where we will face the same issues through midday. BWG
may be skirted by the tail end of this area of snow showers, but it
should be brief enough that it is not worthy of inclusion in the
TAF.
Cold front will move through by late morning, with the window for
snow showers coming to an end a couple hrs later as the upper
impulse finally moves to our east. Cig/vis will improve to VFR this
afternoon, with west winds kicking up to a solid 12-14 kt with gusts
around 20 kt. Look for winds to diminish after sunset as mixing is
lost.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...WINTER WEATHER ADVISORY until 7 PM EST /6 PM CST/ this evening
FOR KYZ023>043-045>049-053>057-061>067.
IN...WINTER WEATHER ADVISORY until 7 PM EST /6 PM CST/ this evening
FOR INZ076>079-083-084-089>092.
&&
$$
Update.........RAS
Short Term.....RAS
Long Term......KJD
Aviation.......RAS
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
635 AM EST FRI JAN 17 2014
.UPDATE...
ISSUED AT 620 AM EST FRI JAN 17 2014
DID A QUICK UPDATE TO TAKE THE FIRST ROUND OF SNOW OUT OF THE GRIDS
AND FIRM UP THE TIMING OF THE NEXT BATCH. ALSO FINE TUNED THE SKY AND
NEAR TERM TEMPS/DEWPOINTS. THESE HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 350 AM EST FRI JAN 17 2014
07Z SFC ANALYSIS SHOWS THE LATEST CLIPPER SYSTEM MOVING THROUGH THE
GREAT LAKES. THIS IS PUSHING AN ARCTIC BOUNDARY INTO THE WESTERN
PORTIONS OF THE OHIO VALLEY. AHEAD OF THIS...A DISTURBANCE AT MID
LEVELS HAS SENT A NEW BATCH OF SNOW SHOWERS THROUGH EAST KENTUCKY
WHITENING SOME PLACES UP TO AN INCH AS IT PASSES. AT THE WEATHER
OFFICE WE PICKED UP A QUICK 7 TENTHS OF AN INCH AS ONE OF THOSE BANDS
MOVED THROUGH. TEMPERATURES AROUND FREEZING AND ROAD TEMPERATURES IN
MOST PLACES ABOVE FREEZING WILL LIMIT THE IMPACT FROM THESE SNOW
SHOWERS. OVER THE SOUTHERN PARTS OF THE CUMBERLAND VALLEY THE
DEWPOINTS HAVE COME UP INTO THE LOW TO MID 30S AND THIS IS LEADING TO
MORE OF A RAIN EVENT WITH THIS ROUND RATHER THAN SNOW. IT IS A FINE
LINE...THOUGH...SO WILL CONTINUE THE SPS THAT IS OUT THROUGH 16Z FOR
THAT AREA. DESPITE A FEW HEAVIER BANDS...THE BULK OF THE AREA WILL
SEE AROUND A HALF AN INCH OF ACCUMULATION OR LESS THOUGH DAWN.
SLIGHTLY BETTER TOTALS CAN BE EXPECTED ALONG AND IN THE IMMEDIATE
WAKE OF THE ARCTIC BOUNDARY LATER TODAY.
THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT AS THEY ALL SHOW A
POTENT SHORTWAVE CROSSING THROUGH THE SOUTHERN OHIO VALLEY TODAY
WITHIN THE HEART OF A DEEP TROUGH. THIS WAVE WILL BRING SOME STEEP
LAPSE RATES TO THE LOWER PART OF THE ATMOSPHERE LATER THIS MORNING
AND THROUGH THE AFTERNOON HELPING TO ENHANCE THE LIFT AND SHOWERY
NATURE OF THE SNOW. THIS FEATURE MOVES QUICKLY OFF TO THE NORTHEAST
TONIGHT AS THE LARGER TROUGH TEMPORARILY RETREATS TO THE NORTH.
ACCORDINGLY...HEIGHTS WILL MODERATE THROUGH THE AREA INTO SATURDAY
MORNING. THIS PROCESS IS THEN QUICKLY REVERSED LATER THAT DAY AS THE
NEXT SHARP WAVE DROPS SOUTHEAST THROUGH THE MIDWEST...MAKING ITS RUN
TOWARD THE OHIO VALLEY. WITH THE GENERAL MODEL AGREEMENT AND THE
MESOSCALE NATURE OF THE SNOW BANDS AND ARCTIC BOUNDARY...HAVE LEANED
TOWARD THE HIGHER RESOLUTION HRRR AND NAM12 THROUGH THE SHORT TERM.
SENSIBLE WEATHER WILL FEATURE THE PRE-DAWN SNOW...AND FAR SOUTHERN
KY RAIN...SHOWERS EXITING THE AREA WITH A BIT OF A LULL IN ANY PCPN
ACTIVITY UNTIL AROUND MID MORNING IN THE WEST WHEN THE ARCTIC
BOUNDARY MOVES INTO THE CWA. THIS WILL BRING ANOTHER ROUND OF SNOW
SHOWERS...COLDER TEMPERATURES...AND BRISK WINDS TO THE AREA TODAY.
ALTHOUGH MOISTURE IS LIMITED WITH THIS...STILL EXPECT THE LIFT ALONG
THE FRONT AND STEEP LAPSE RATES BEHIND IT TO SUPPORT SNOW SHOWERS
INTENSE ENOUGH TO ACCUMULATE FOR MOST LOCATIONS...GENERALLY A HALF TO
ONE INCH THROUGH EARLY EVENING. TWO INCHES OR MORE INCHES WILL BE
POSSIBLE IN THE HIGHEST TERRAIN NEAR THE VIRGINA BORDER THROUGH
MIDNIGHT. IN ADDITION TO THE SNOW...BRISK WINDS ACCOMPANYING THE SNOW
WILL LIMIT VISIBILITIES AT TIMES TO A MILE OR LESS...POTENTIALLY
CREATING BRIEF PERIODS OF HAZARDOUS TRAVEL. THE SNOW SHOWERS WILL
TAPER TO FLURRIES AND END FROM WEST TO EAST ON SATURDAY NIGHT WITH
TEMPERATURES PLUMMETING INTO THE TEENS BY DAWN. FOR THE BULK OF THE
DAY SATURDAY THE WX WILL BE QUIET BETWEEN DISTURBANCES. HOWEVER...BY
EVENING THICKER AND LOWER CLOUDS WILL BE ROLLING BACK IN FROM THE
NORTHWEST WITH SOME SNOW POSSIBLE BEFORE DARK IN OUR NORTHWEST
COUNTIES.
FOR THE ARCTIC BOUNDARY MOVING THROUGH THE CWA THIS MORNING AND
AFTERNOON WILL ISSUE AN EXTENSION TO THE WSW TO COVER THE ENTIRE
CWA...LINGERING IT INTO THE LATE EVENING IN THE FAR EAST. THE ONLY
DIFFERENCE FROM THE CURRENT ONE IS THAT THIS EXTENSION WILL NOT GO
INTO EFFECT UNTIL AFTER 15Z.
FOLLOWED A BLEND OF THE DIURNAL FROM NAM12 AND THE CONSSHORT FOR
HOURLY TEMPS WHILE FAVORED THE BCCONSSHORT FOR TD AND WINDS THROUGH
THE FIRST 24 HOURS...STARTING WITH THE CONSALL THEREAFTER AND FOR MAX
AND MIN TEMPS THROUGH SATURDAY. AS FOR POPS...ENDED UP HIGHER THAN
ALL GUIDANCE FOR TODAY THROUGH TONIGHT GIVEN THE LOW QPF NATURE OF
THIS EVENT.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 337 AM EST FRI JAN 17 2014
AN ACTIVE AND VERY PROGRESSIVE EXTENDED PERIOD BEGINS ON SATURDAY
NIGHT WITH A POSITIONED BROAD TROUGH OVER THE NORTHEASTERN CONUS AND
REMAINING THERE FOR THE ENTIRE EXTENDED. BEFORE DELVING INTO THE
SPECIFICS...THE MODELS DO AGREE ON A RIDGE TROUGH LONGWAVE PATTERN
THROUGH THE EXTENDED. THE TRUE FORECAST CHALLENGE FOR THIS PERIOD
FALLS ON HOW THE MODELS HANDLE THE ARRIVAL OF EACH SHORT WAVES THAT
WILL ROTATE DOWN OUT OF CANADA AND INTO THE GREAT LAKES OHIO VALLEY
REGION. THIS COUPLE WITH THE CHALLENGE OF DETERMINING THE MOISTURE
AVAILABLE...WILL BE QUITE A PROBLEM.
THIS IN MIND...WILL STAY CLOSE TO THE MODEL ALL BLEND AND ENSEMBLE
SOLUTIONS AND DECREASING PROBABILITIES WHERE CONFIDENCE IS LOW. THE
FIRST SIGNIFICANT WAVE MOVES THROUGH THE AREA ON SUNDAY. WITH THE
COLDER AIR ALREADY IN PLACE...THE PRECIP TYPE WITH THIS SYSTEM
SHOULD FALL AS SNOW AND THE INSTABILITY THE MODEL PROFILES ARE
SHOWING WOULD INDICATE AT SOME ACCUMULATING SNOWFALL POSSIBLE WITH
TEMPS COLD ENOUGH AND A GOOD SHOT OF OMEGA IN THE SATURATED -10 TO
-20 REGION FOR A GOOD 2 TO 3 HOUR PERIOD ON SUNDAY MORNING. WILL
NEED TO WATCH FOR THIS SYSTEM...ESPECIALLY WITH A FAVORABLE WIND
DIRECTION FOR SOME UP SLOPE ASSISTANCE. MODELS DO HAVE A GOOD BIT
AGREEMENT WITH THIS AND THIS WAVE IS POSSIBLY THE ONLY WAVE TO PUT
SOME CONFIDENCE IN AS AFTER THIS FEATURE MOVES THROUGH...THE MODELS
WAFFLE WITH THE CHARACTERISTICS OF THE SHORTWAVES LATER IN THE
EXTENDED.
AFTER THIS STRONG WAVE ON SUNDAY PUSHES THROUGH...A BUILDING ARCTIC
AIR MASS WILL DIVE SOUTH AS THE SEMI PERMANENT 500 TROUGH OVER THE
NORTHEAST DIGS A BIT FURTHER SOUTH INTO THE SOUTHERN APPALACHIANS.
THIS WILL BRING TEMPS INTO THE 20S FOR HIGHS AND TEENS FOR LOWS BY
TUESDAY AND THROUGH THE REST OF THE EXTENDED. THE FOLLOWING PIECES
OF ENERGY ON TUESDAY AND THURSDAY ARE QUITE WEAK AND EVEN THE EURO
IS INCONSISTENT WITH THESE WAVES AS IT WILL SHIFT THE WAVES ABOUT 1
TO 2 HUNDRED MILES TO THE EAST FROM RUN TO RUN. WITH THIS TYPE OF
INCONSISTENCY...HAVE GONE WITH SLIGHT CHANCE POPS FROM DAY 4 THROUGH
DAY 7. THE COLDER TEMPS EXPECTED THOUGH WILL ASSURE ANY PRECIP
FALLING AFTER DAY 4 WILL BE SNOW. IT IS SOMEWHAT ENCOURAGING THAT
TELECONNECTIONS AT THIS POINT SUPPORT FALLING TEMPS AFTER TUESDAY SO
THAT IS ONE PARAMETER THAT CAN BE COUNTED ON.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 635 AM EST FRI JAN 17 2014
WE ARE NOW IN A LULL BETWEEN THESE SNOW SYSTEMS. THIS WILL RESULT IN
SPOTTY MVFR CIGS FOR THE NEXT SEVERAL HOURS...BUT GOOD VIS. THE CIGS
WILL LOWER MORE PERMANENTLY WITH THE ARRIVAL OF THE NEXT BATCH OF
SNOW. THIS NEXT BATCH OF SNOW WILL LAST THROUGH THE AFTERNOON WITH AN
ACCOMPANYING ARCTIC BOUNDARY ENOUGH FOR VIS AND CIGS TO FALL BACK
DOWN TO MVFR AND BRIEFLY WORSE. THIS LATEST AREA OF SNOW WILL
GRADUALLY WANE INTO THE EVENING WITH CIGS LIKELY IMPROVING AND VIS
ABOVE 6 MILES EVEN AS A FEW FLURRIES CONTINUE OVER THE AREA. WINDS
WILL BE SOUTHWEST AT 5 TO 10 KTS WITH AN OCCASIONAL GUST TO 15 KTS
UNTIL BETWEEN 15 AND 20Z WHEN THE BOUNDARY MOVES IN AND SWITCHES THEM
TO THE WEST AT 10 TO 20 KTS FOR THE BULK OF THE DAY...DIMINISHING
BELOW 10 KTS ONLY DURING THE EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR KYZ044-
050>052-058>060-068-069-079-080-104-106-108-111-114.
WINTER WEATHER ADVISORY FROM NOON TODAY TO MIDNIGHT EST TONIGHT
FOR KYZ087-088-110-113-115-117-118-120.
WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR
KYZ083>086-107-109-112-116-119.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
702 AM EST FRI JAN 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 533 AM EST FRI JAN 17 2014
NO CHANGES TO TIMING OF LAKE EFFECT SNOW ADVISORIES ALONG LAKE
SUPERIOR TO THE EAST OF GRAND MARAIS FOR LAKE ENHANCED SNOW AND
BLOWING/DRIFTING SNOW.
SFC LOW IS OVER NORTHERN LAKE MICHIGAN AS OF 10Z. TROUGH EXTENDS
BACK INTO NCNTRL UPR MICHIGAN. WIND SHIFT IS PRESSING SOUTH BTWN BIG
BAY AND MARQUETTE. THUS FAR OVERNIGHT...SNOW AMOUNTS HAVE BEEN IN
THE 3 TO 6 INCH RANGE OVER WEST AND NORTHWEST UPR MICHIGAN. THE MOST
SNOW HAS OCCURRED VCNTY OF IRONWOOD AND BERGLAND. ALSO SAW A BURST
OF HEAVIER SNOW MAKE IT AS FAR SOUTH AS SOUTHERN DELTA COUNTY. RADAR
ALGORITM INDICATED 2 TO 3 INCHES OVERNIGHT IN THE RAPID RIVER AREA.
APPEARS THAT THIS BURST OF SNOW WELL AWAY FM LK SUPERIOR IS SETTLING
DOWN NOW. FINALLY...ANOTHER BIG ISSUE OVER THE WEST AND NORTHWEST
CWA IS BLSN/DRSN THAT IS REDUCING VSBY...ESPECIALLY IN OPEN AREAS
NEAR LAKE SUPERIOR...WHERE KEWEENAW COUNTY SHERIFF REPORTED HEAVY
BLOWING AND DRIFTING SNOW WAS OCCURRING.
WV LOOP SHOWING THAT A SHORTWAVE IS ENHANCING OVER CNTRL UPR
MICHIGAN/SCNTRL LK SUPERIOR SINCE MIDNIGHT. RADAR REFLECTIVITIES
HAVE SHOWN THIS AS WELL WITH MORE 25+ DBZ ECHOES APPEARING OVER
NORTHERN MARQUETTE COUNTY IN THE LAST FEW HOURS. EXPECT AFFECTS OF
SHORTWAVE TO FINISH UP IN THE NEXT FEW HOURS OVER WESTERN CWA WITH
ENHANCEMENT TAPERING OFF THERE. ENHANCEMENT LIKELY WILL LAST WELL
INTO THE MORNING FOR NCNTRL UPR MICHIGAN THOUGH. SNOW AMOUNTS WILL
BE SUPPORTED FURTHER BY STRONGER LOW-LEVEL CONVERGENCE...AFFECTING
NORTHERN MARQUETTE COUNTY INTO WESTERN ALGER COUNTY AS NORTH WINDS
OVER LK SUPERIOR CONVERGE WITH NW WINDS OVER THE LAND AREAS. SNOW
AMOUNTS THROUGH THE DAY SHOULD MAXIMIZE OUT OVER NORTHERN AND
EASTERN MARQUETTE COUNTY...WITH ADDITIONAL SNOWFALL OF 3 TO 6 INCHES
LIKELY OVER PRETTY WIDE AREA. A BIT CONCERNED MAY NEED A WARNING AS
WINDS JUST OFF SFC ARE MAINLY NORTHEAST AND MODELS ARE NOT PICKING
UP ON THAT. ONLY RUC13 SHOWS THIS...BUT NOT UNTIL 14Z. NOT SURE IF
THIS IS SITUATION THAT MODELS ARE TOO SLOW OR FAVORABLE NE UPSLOPE
WILL PERSIST WELL INTO THE DAY. IF IT DOES...SNOW AMOUNTS WILL BE
PUSHING THE 8 INCH/12 HR CRITERIA. BLSN/DRSN ISSUES WILL ALSO
INCREASE AS NORTH WINDS GUST OVER 30 MPH. OPEN AREAS AND AREAS ALONG
LK SUPERIOR WILL BE MOST VULNERABLE TO POOR VSBY. COORIDORS OF SUB
QUARTER MILE VSBY SEEM LIKELY IN THE HEAVIER SNOW AREAS THIS
MORNING. WILL NEED TO WATCH THIS AS WELL. EVENTUALLY AS SHORTWAVE
DROPS MORE ESE...HEAVIER SNOW SHOWERS AND BLSN/DRSN ISSUES WILL
BEGIN TO AFFECT WESTERN ALGER COUNTY. CONTINUED TO HIGHLIGHT
POTENTIAL FOR DIFFICULT TRAVEL ON M-28 LATER THIS MORNING WITH
SNOW/BLSN/DRSN.
ONCE THE SHORTWAVE AND LARGER SCALE TROUGHING SLIDE MAINLY EAST OF
CWA BY LATE THIS AFTN...EXPECT WEATHER TO QUIET DOWN. SOUNDINGS FOR
THIS EVENING EVEN WHERE FLOW BLO 5KFT REMAINS ONSHORE LOOKING MORE
AND MORE HOSTILE FOR NOTHING MORE THAN LGT LAKE EFFECT OR FLURRIES.
KEPT POPS HIGH IN THE SNOWBELTS EAST OF MARQUETTE BUT SNOW AMOUNTS
LOOK MINIMAL. OVER WEST HALF OF UPR MICHIGAN...EXPECT CLEARING SKIES
FOR GOOD PART OF NIGHT UNTIL HIGH CLOUDS INCREASE LATE AHEAD OF
SYSTEM DIGGING DOWN INTO THE NORTHERN PLAINS. SYSTEM HAS TRENDED
FARTHER WEST...SO IMPACTS FM THE CLOUDS MAY END UP BEING LESS AND
LESS. KEPT WITH THEME OF SUB ZERO TEMPS FOR MUCH OF WEST HALF
INTERIOR. THESE TEMPS MAY NEED FURTHER LOWERING IF CLOUDS DO NOT COME
IN AT ALL LATER TONIGHT AS WINDS WILL BE LIGHT AND RADITIONAL COOLING
WILL BE IDEAL.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 436 AM EST FRI JAN 17 2014
NAM SHOWS A 500 MB TROUGH OVER THE GREAT LAKES REGION 12Z SAT WITH A
SHORTWAVE OVER MN. THIS SHORTWAVE DIGS SOUTHEAST INTO ILLINOIS BY
00Z SUN AND LOOKS LIKE IT WILL STAY TO THE WEST OF THE AREA. NAM
BRINGS IN ANOTHER SHORTWAVE THAT WILL AFFECT THE AREA SUN NIGHT.
WITH FIRST SHORTWAVE AND COLD AIR GOING TO THE WEST OF THE
AREA...CUT BACK ON EASTWARD EXTENT OF POPS ON SAT. WITH LESS
COVER...MORE SUNSHINE WILL OCCUR WITH SW WINDS AND WENT A BIT HIGHER
FOR TEMPERATURES. COLD AIR COMES IN SAT NIGHT INTO SUNDAY WITH
TEMPERATURES NOT GOING UP MUCH ON SUNDAY. WENT HIGHEST POPS IN NW
LAKE EFFECT SNOW BELTS. OTHERWISE...NOT MANY CHANGES TO THE GOING
FORECAST.
IN THE EXTENDED...GFS AND ECMWF SHOW A BROAD 500 MB TROUGH OVER THE
CENTRAL U.S. 12Z MON WITH VERY COLD AIR OVER THE AREA AGAIN WITH 850
MB TEMPERATURES DOWN TO -25C OR SO. THIS TROUGH DIGS OVER THE LOWER
GREAT LAKES 12Z TUE AND THE TROUGH CONTINUES WITH THE COLD AIR 12Z
WED WITH THE TROUGH AXIS OVER NEW ENGLAND ON THU. TEMPERATURES WILL
REMAIN BELOW NORMAL THIS FORECAST PERIOD WITH LAKE EFFECT SNOW
CONTINUING THROUGH WED NIGHT. WITH NORTHERLY WINDS...WENT HIGH POPS
IN NORTHERLY AFFECTED LAKE EFFECT SNOW BELTS. DID NOT MAKE TOO MANY
CHANGES TO THE GOING FORECAST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 701 AM EST FRI JAN 17 2014
LAKE ENHANCED SNOW AND BLOWING SNOW WILL BRING IFR CONDITIONS TO
KIWD AND KCMX EARLY...BUT EXPECT IMPROVEMENT TO MVFR THIS AFTERNOON.
AS WINDS BACK W TO SW WITH ARRIVAL OF SFC HIGH PRES RIDGE...MVFR
CIGS WILL CLEAR OUT AT KIWD EARLY THIS EVENING AND OVERNIGHT AT
KCMX. AT KSAW...PASSAGE OF SFC TROF EARLY THIS MORNING WILL BRING
HEAVIER SHSN/BLSN AND IFR CONDITIONS. NOT OUT OF THE QUESTION THAT A
FEW PERIODS OF LIFR COULD OCCUR THIS MORNING AND HAVE PUT A TEMPO
GROUP IN FOR THIS. EXPECT IMPROVEMENT TO MVFR THIS AFTN AS WINDS
BEGIN TO BACK NORTHWEST. MVFR CIGS WILL CLEAR OUT THIS EVENING
AT KSAW AS WINDS BACK FURTHER.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 436 AM EST FRI JAN 17 2014
GALES OVER CENTRAL LAKE SUPERIOR WILL CONTINUE TO WIND DOWN TODAY.
NEXT GALE EVENT LOOKS TO BE SAT NIGHT INTO SUNDAY ACROSS THE EAST
HALF OF LAKE SUPERIOR WITH COLD AIR MOVING ACROSS LAKE SUPERIOR
AGAIN. HEAVY FREEZING SPRAY WILL LAST INTO THIS EVENING ACROSS LAKE
SUPERIOR BEFORE WINDS DIE DOWN ENOUGH TO STOP CAUSING IT. HEAVY
FREEZING SPRAY WILL AGAIN OCCUR SUNDAY INTO TUE SINCE THE INCOMING
AIRMASS WILL BE QUITE COLD. THERE WILL BE SOME HEAVY FREEZING SPRAY
WHERE WAVE ACTION IS HIGHEST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
MIZ006.
LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST /9 AM CST/ THIS
MORNING FOR MIZ001>004-009.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ005.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL MIDNIGHT EST TONIGHT FOR
LSZ245-248-249-265-266.
GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ245-248-249-
265-266.
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST /NOON CST/ THIS
AFTERNOON FOR LSZ162.
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST THIS EVENING FOR
LSZ244-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...07
AVIATION...JLA
MARINE...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
535 AM EST FRI JAN 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 533 AM EST FRI JAN 17 2014
NO CHANGES TO TIMING OF LAKE EFFECT SNOW ADVISORIES ALONG LAKE
SUPERIOR TO THE EAST OF GRAND MARAIS FOR LAKE ENHANCED SNOW AND
BLOWING/DRIFTING SNOW.
SFC LOW IS OVER NORTHERN LAKE MICHIGAN AS OF 10Z. TROUGH EXTENDS
BACK INTO NCNTRL UPR MICHIGAN. WIND SHIFT IS PRESSING SOUTH BTWN BIG
BAY AND MARQUETTE. THUS FAR OVERNIGHT...SNOW AMOUNTS HAVE BEEN IN
THE 3 TO 6 INCH RANGE OVER WEST AND NORTHWEST UPR MICHIGAN. THE MOST
SNOW HAS OCCURRED VCNTY OF IRONWOOD AND BERGLAND. ALSO SAW A BURST
OF HEAVIER SNOW MAKE IT AS FAR SOUTH AS SOUTHERN DELTA COUNTY. RADAR
ALGORITM INDICATED 2 TO 3 INCHES OVERNIGHT IN THE RAPID RIVER AREA.
APPEARS THAT THIS BURST OF SNOW WELL AWAY FM LK SUPERIOR IS SETTLING
DOWN NOW. FINALLY...ANOTHER BIG ISSUE OVER THE WEST AND NORTHWEST
CWA IS BLSN/DRSN THAT IS REDUCING VSBY...ESPECIALLY IN OPEN AREAS
NEAR LAKE SUPERIOR...WHERE KEWEENAW COUNTY SHERIFF REPORTED HEAVY
BLOWING AND DRIFTING SNOW WAS OCCURRING.
WV LOOP SHOWING THAT A SHORTWAVE IS ENHANCING OVER CNTRL UPR
MICHIGAN/SCNTRL LK SUPERIOR SINCE MIDNIGHT. RADAR REFLECTIVITIES
HAVE SHOWN THIS AS WELL WITH MORE 25+ DBZ ECHOES APPEARING OVER
NORTHERN MARQUETTE COUNTY IN THE LAST FEW HOURS. EXPECT AFFECTS OF
SHORTWAVE TO FINISH UP IN THE NEXT FEW HOURS OVER WESTERN CWA WITH
ENHANCEMENT TAPERING OFF THERE. ENHANCEMENT LIKELY WILL LAST WELL
INTO THE MORNING FOR NCNTRL UPR MICHIGAN THOUGH. SNOW AMOUNTS WILL
BE SUPPORTED FURTHER BY STRONGER LOW-LEVEL CONVERGENCE...AFFECTING
NORTHERN MARQUETTE COUNTY INTO WESTERN ALGER COUNTY AS NORTH WINDS
OVER LK SUPERIOR CONVERGE WITH NW WINDS OVER THE LAND AREAS. SNOW
AMOUNTS THROUGH THE DAY SHOULD MAXIMIZE OUT OVER NORTHERN AND
EASTERN MARQUETTE COUNTY...WITH ADDITIONAL SNOWFALL OF 3 TO 6 INCHES
LIKELY OVER PRETTY WIDE AREA. A BIT CONCERNED MAY NEED A WARNING AS
WINDS JUST OFF SFC ARE MAINLY NORTHEAST AND MODELS ARE NOT PICKING
UP ON THAT. ONLY RUC13 SHOWS THIS...BUT NOT UNTIL 14Z. NOT SURE IF
THIS IS SITUATION THAT MODELS ARE TOO SLOW OR FAVORABLE NE UPSLOPE
WILL PERSIST WELL INTO THE DAY. IF IT DOES...SNOW AMOUNTS WILL BE
PUSHING THE 8 INCH/12 HR CRITERIA. BLSN/DRSN ISSUES WILL ALSO
INCREASE AS NORTH WINDS GUST OVER 30 MPH. OPEN AREAS AND AREAS ALONG
LK SUPERIOR WILL BE MOST VULNERABLE TO POOR VSBY. COORIDORS OF SUB
QUARTER MILE VSBY SEEM LIKELY IN THE HEAVIER SNOW AREAS THIS
MORNING. WILL NEED TO WATCH THIS AS WELL. EVENTUALLY AS SHORTWAVE
DROPS MORE ESE...HEAVIER SNOW SHOWERS AND BLSN/DRSN ISSUES WILL
BEGIN TO AFFECT WESTERN ALGER COUNTY. CONTINUED TO HIGHLIGHT
POTENTIAL FOR DIFFICULT TRAVEL ON M-28 LATER THIS MORNING WITH
SNOW/BLSN/DRSN.
ONCE THE SHORTWAVE AND LARGER SCALE TROUGHING SLIDE MAINLY EAST OF
CWA BY LATE THIS AFTN...EXPECT WEATHER TO QUIET DOWN. SOUNDINGS FOR
THIS EVENING EVEN WHERE FLOW BLO 5KFT REMAINS ONSHORE LOOKING MORE
AND MORE HOSTILE FOR NOTHING MORE THAN LGT LAKE EFFECT OR FLURRIES.
KEPT POPS HIGH IN THE SNOWBELTS EAST OF MARQUETTE BUT SNOW AMOUNTS
LOOK MINIMAL. OVER WEST HALF OF UPR MICHIGAN...EXPECT CLEARING SKIES
FOR GOOD PART OF NIGHT UNTIL HIGH CLOUDS INCREASE LATE AHEAD OF
SYSTEM DIGGING DOWN INTO THE NORTHERN PLAINS. SYSTEM HAS TRENDED
FARTHER WEST...SO IMPACTS FM THE CLOUDS MAY END UP BEING LESS AND
LESS. KEPT WITH THEME OF SUB ZERO TEMPS FOR MUCH OF WEST HALF
INTERIOR. THESE TEMPS MAY NEED FURTHER LOWERING IF CLOUDS DO NOT COME
IN AT ALL LATER TONIGHT AS WINDS WILL BE LIGHT AND RADITIONAL COOLING
WILL BE IDEAL.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 436 AM EST FRI JAN 17 2014
NAM SHOWS A 500 MB TROUGH OVER THE GREAT LAKES REGION 12Z SAT WITH A
SHORTWAVE OVER MN. THIS SHORTWAVE DIGS SOUTHEAST INTO ILLINOIS BY
00Z SUN AND LOOKS LIKE IT WILL STAY TO THE WEST OF THE AREA. NAM
BRINGS IN ANOTHER SHORTWAVE THAT WILL AFFECT THE AREA SUN NIGHT.
WITH FIRST SHORTWAVE AND COLD AIR GOING TO THE WEST OF THE
AREA...CUT BACK ON EASTWARD EXTENT OF POPS ON SAT. WITH LESS
COVER...MORE SUNSHINE WILL OCCUR WITH SW WINDS AND WENT A BIT HIGHER
FOR TEMPERATURES. COLD AIR COMES IN SAT NIGHT INTO SUNDAY WITH
TEMPERATURES NOT GOING UP MUCH ON SUNDAY. WENT HIGHEST POPS IN NW
LAKE EFFECT SNOW BELTS. OTHERWISE...NOT MANY CHANGES TO THE GOING
FORECAST.
IN THE EXTENDED...GFS AND ECMWF SHOW A BROAD 500 MB TROUGH OVER THE
CENTRAL U.S. 12Z MON WITH VERY COLD AIR OVER THE AREA AGAIN WITH 850
MB TEMPERATURES DOWN TO -25C OR SO. THIS TROUGH DIGS OVER THE LOWER
GREAT LAKES 12Z TUE AND THE TROUGH CONTINUES WITH THE COLD AIR 12Z
WED WITH THE TROUGH AXIS OVER NEW ENGLAND ON THU. TEMPERATURES WILL
REMAIN BELOW NORMAL THIS FORECAST PERIOD WITH LAKE EFFECT SNOW
CONTINUING THROUGH WED NIGHT. WITH NORTHERLY WINDS...WENT HIGH POPS
IN NORTHERLY AFFECTED LAKE EFFECT SNOW BELTS. DID NOT MAKE TOO MANY
CHANGES TO THE GOING FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1149 PM EST THU JAN 16 2014
SFC TROF DROPPING S ACROSS LAKE SUPERIOR/UPPER MI WILL BRING A
PERIOD OF STRONGER N TO NW WINDS OVERNIGHT INTO THE MORNING.
INITIALLY...DEEP MOISTURE/UPSLOPE FLOW SHOULD RESULT IN PREVAILING
IFR CONDITIONS AT KIWD/KCMX WITH SOME PERIODS OF LIFR AT KCMX DUE TO
STRONGER WINDS AND RESULTING BLSN. EXPECT IMPROVEMENT TO MVFR AT
KIWD/KCMX MID TO LATE MORNING. AS WINDS BACK W TO SW WITH ARRIVAL OF
SFC HIGH PRES RIDGE...MVFR CIGS WILL CLEAR OUT AT KIWD EARLY THIS
EVENING. AT KSAW...MVFR CONDITIONS SHOULD PREVAIL FOR THE OVERNIGHT.
PASSAGE OF SFC TROF TOWARD DAYBREAK WILL BRING HEAVIER SHSN/BLSN AND
IFR CONDITIONS. NOT OUT OF THE QUESTION THAT A FEW PERIODS OF LIFR
COULD OCCUR THIS MORNING. EXPECT IMPROVEMENT TO MVFR EARLY THIS AFTN
AS WINDS BEGIN TO BACK. MVFR CIGS WILL CLEAR OUT THIS EVENING AT
KSAW AS WINDS BACK FURTHER.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 436 AM EST FRI JAN 17 2014
GALES OVER CENTRAL LAKE SUPERIOR WILL CONTINUE TO WIND DOWN TODAY.
NEXT GALE EVENT LOOKS TO BE SAT NIGHT INTO SUNDAY ACROSS THE EAST
HALF OF LAKE SUPERIOR WITH COLD AIR MOVING ACROSS LAKE SUPERIOR
AGAIN. HEAVY FREEZING SPRAY WILL LAST INTO THIS EVENING ACROSS LAKE
SUPERIOR BEFORE WINDS DIE DOWN ENOUGH TO STOP CAUSING IT. HEAVY
FREEZING SPRAY WILL AGAIN OCCUR SUNDAY INTO TUE SINCE THE INCOMING
AIRMASS WILL BE QUITE COLD. THERE WILL BE SOME HEAVY FREEZING SPRAY
WHERE WAVE ACTION IS HIGHEST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
MIZ006.
LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST /9 AM CST/ THIS
MORNING FOR MIZ001>004-009.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ005.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL MIDNIGHT EST TONIGHT FOR
LSZ245-248-249-265-266.
GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ245-248-249-
265-266.
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST /NOON CST/ THIS
AFTERNOON FOR LSZ162.
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST THIS EVENING FOR
LSZ244-263-264.
GALE WARNING UNTIL 7 AM EST THIS MORNING FOR LSZ243-244-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...07
AVIATION...ROLFSON
MARINE...07
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
726 AM EST FRI JAN 17 2014
.SYNOPSIS...
AN ARCTIC COLD FRONT WILL PUSH EAST ACROSS THE REGION TODAY. WEAK
SURFACE RIDGING IS THEN EXPECTED TO BUILD BRIEFLY INTO THE AREA
TONIGHT AND EARLY ON SATURDAY. A CLIPPER SYSTEM WILL THEN RAPIDLY
SPREAD SNOW BACK INTO THE AREA SATURDAY AFTERNOON AND NIGHT.
SURFACE RIDGING WILL PUSH BACK INTO THE AREA ON SUNDAY IN THE WAKE
OF THE CLIPPER SYSTEM. ANOTHER ARCTIC COLD FRONT WILL FOLLOW ON
MONDAY BRINGING A RETURN OF VERY COLD AIR FOR THE MIDDLE OF NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BASED ON RADAR TRENDS AND CONTINUED TREND OF THE RAP...THINK
LOCALLY 2 INCHES WILL BE POSSIBLE ACROSS SOUTHWEST PORTIONS OF OUR
FA. HAVE THEREFORE OPTED TO GO WITH A QUICK ADVISORY FOR THE
CINCINNATI AREA.
PREVIOUS DISCUSSION--->
LOOKING AT THE LATEST RADAR TRENDS...PCPN MAINLY IN THE FORM OF
SNOW SHOWERS...WAS CONGEALING TOGETHER WEST AND SOUTHWEST OF THE
CWFA. THE LATEST NAM-WRF AND RAP ARE NOW INDICATING STRONGER LOW
LEVEL CONVERGENCE MOVING INTO THE WESTERN PARTS OF THE CWFA THIS
MORNING...RESULTING IN HIGHER MODEL QPF VALUES. HAVE TRENDED QPF
AMOUNTS UPWARD IN THESE AREAS...ALTHOUGH NOT AS HIGH AS THE MODELS
SUGGEST. THIS ALLOWS FOR SNOWFALL AMOUNTS TO RANGE BETWEEN 1 AND 2
INCHES IN THE WESTERN ZONES WITH UP TO AN INCH ELSEWHERE. HAVE
UPDATED THE SPS TO INCLUDE THIS NEW THINKING. WILL CONTINUE TO
MONITOR RADAR TRENDS AND MODELS SHOULD AN ADVISORY HEADLINE BE
NEEDED IF AMOUNTS LOOK TO BE HIGHER THAN CURRENTLY FORECAST.
REMAINDER OF THE DISCUSSION IS STILL GOOD BELOW.
PREVIOUS DISCUSSION--->
HAVE LEANED MORE TOWARD HIGHER RES MODELS FOR TODAYS FORECAST.
AN ARCTIC COLD FRONT WILL PUSH EAST ACROSS THE REGION THIS MORNING
INTO THE EARLY AFTERNOON HOURS. MODELS SUGGEST THAT A WEAK SFC LOW
WILL DEVELOP ALONG THIS FRONT. THIS SFC LOW WILL PROVIDE AN AXIS
OF LOW LEVEL CONVERGENCE FOR SNOW SHOWERS TO DEVELOP ON. AS A
RESULT...IT LOOKS LIKE THE ENTIRE FORECAST AREA SHOULD SEE A
PERIOD OF SNOW SHOWERS AHEAD AND ALONG THE FRONT AS IT MOVES EAST.
WARMER AIR BEING DRAWN INTO THE REGION AHEAD OF THE COLD FRONT MAY
ALLOW SOME RAIN TO BRIEFLY MIX IN OUR EASTERN ZONES. HOWEVER...THE
WET BULB EFFECT MAY PREVENT THIS FROM HAPPENING SO HAVE KEPT PTYPE
ALL SNOW AT THIS TIME. SNOW ACCUMULATION...UP TO AN INCH...WILL
OCCUR IN A SHORT PERIOD OF TIME. THIS AMOUNT...ALONG WITH REDUCED
VISIBILITIES IN SOME OF THE MODERATE TO LOCALLY HEAVY SNOW
SHOWERS...WILL POSE A TRAVEL THREAT FOR THE ENTIRE REGION TODAY.
HAVE THUS ISSUES AN SPS HIGHLIGHTING THIS THREAT. A WELL DEFINED
S/WV (VORT MAX) ALOFT WILL PUSH ACRS THE AREA THIS AFTERNOON/THIS
EVENING IN THE WAKE OF THE FRONT. THIS FEATURE...ALONG WITH
STEEPING LOW LEVEL LAPSE RATES AND SOME WEAK LOW LEVEL SPEED
CONVERGENCE SHOULD KEEP SNOW SHOWER ACTIVITY GOING SOME BEHIND THE
ARCTIC FRONT. THIS ACTIVITY...HOWEVER...SHOULD BE LIGHTER IN
NATURE WITH LITTLE ADDITIONAL ACCUMULATION EXPECTED.
TEMPERATURES WILL BE TRICKY TODAY GIVEN SOME WAA THIS MORNING
AHEAD OF THE FRONT WITH TEMPERATURES TUMBLING IN THE WAKE OF THE
FRONT. EVEN THE HIGH RES MODELS ARE HAVING A HARD TIME CAPTURING
CURRENT CONDITIONS. HIGHS SHOULD RANGE FROM THE MID 20S NW TO THE
MID 30S SE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
EMBEDDED S/WV (VORT MAX) WILL EXIT TO THE NE OF THE REGION THIS
EVENING. AS IT DOES...SNOW SHOWER ACTIVITY SHOULD WANE FROM WEST
TO EAST. WEAK SURFACE RIDGING IS THEN EXPECTED TO BUILD INTO THE
OHIO VALLEY OVERNIGHT. LOWS WILL BOTTOM OUT IN THE 10 TO 15 DEGREE
RANGE BY SATURDAY MORNING.
MODELS ARE IN DECENT AGREEMENT IN TERMS OF A CLIPPER SYSTEM TO
AFFECT OUR AREA LATER SATURDAY AFTERNOON AND NIGHT. HAVE USED A
BLEND OF THE GFS/ECMWF GIVEN BETTER SIMILARITY TO SYNOPTIC
FEATURES. SURFACE RIDGE WILL RAPIDLY MOVE EAST ON SATURDAY AS THE
CLIPPER DIVES SE FROM THE NRN PLAINS TO THE OHIO VALLEY BY
SATURDAY NIGHT. GOOD WAA/ISENTROPIC LIFT WILL ACCOMPANY THIS
SYSTEM AS IT ENTERS OUR AREA LATE SATURDAY AFTERNOON AND EVENING.
THEREAFTER...MODELS SHOW A FAIRLY RAPID WEAKENING TO THE SYSTEM AS IT
SHIFTS EAST OVERNIGHT...BECOMING ABSORBED WITH A STRONGER...LARGE
SCALE UPR LVL LOW DIGGING INTO QUEBEC. HAVE GONE WITH CATEGORICAL
POPS ALL LOCATIONS. 1 TO 2 INCHES OF SNOW LOOKS FAIRLY REASONABLE
REGION WIDE WITH PERHAPS SOME 3 INCH AMOUNTS POSSIBLE NORTH OF THE
CINCINNATI AND JUST SOUTH OF DAYTON PER LATEST MODEL RUNS. WILL
CONTINUE TO HIGHLIGHT THIS SYSTEM IN THE HWO. TEMPERATURES
SATURDAY INTO SATURDAY NIGHT WILL SHOW WARMING DUE TO WAA AHEAD OF
THE CLIPPER FOLLOWED BY A LITTLE COOL DOWN TOWARD SUNRISE SUNDAY.
ON SUNDAY...SFC RIDGING WILL MOVE INTO THE OHIO VALLEY. WE SHOULD
SEE CLOUDS SCATTERED BY AFTERNOON...ALLOWING FOR SOME SUNSHINE.
REGION WILL BE CAUGHT BETWEEN SFC RIDGE AND ANOTHER ARCTIC COLD
FRONT TO OUR NORTH AND NORTHWEST. THE PRESSURE GRADIENT BETWEEN
THESE TWO FEATURES WILL RESULT IN BREEZY CONDITIONS BUT WILL ALSO
ALLOW FOR SOME WARMING.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A COLD FRONT WILL DROP DOWN INTO THE FA ON MONDAY. MOISTURE IS
LIMITED WITH THIS FEATURE AND THEREFORE LIMITED SNOWFALL CHANCES
AT THIS TIME TO A SLIGHT CHANCE. MUCH COLDER AIR WILL BE USHERED
INTO THE AREA HOWEVER FOR THE REMAINDER OF THE LONG TERM TIME
FRAME.
THE LOWEST TEMPERATURES ARE EXPECTED TO OCCUR WEDNESDAY MORNING AND
THURSDAY MORNING. WIND CHILL VALUES WEDNESDAY MORNING WILL BE NEAR
WIND CHILL ADVISORY CRITERIA.
SOME LAKE EFFECT SNOW SHOWERS WILL BE POSSIBLE ACROSS PORTIONS OF
THE FA MONDAY NIGHT INTO TUESDAY EVENING. AFTER THIS TIME WENT WITH
DRY CONDITIONS ACROSS THE FA. THE GFS IS HINTING AT A DISTURBANCE
MOVING THROUGH THE FA WEDNESDAY NIGHT INTO THURSDAY MORNING HOWEVER
THERE HAS BEEN QUITE A BIT OF RUN TO RUN DIFFERENCES DURING THIS
TIME AND THE ECMWF HAS DRY CONDITIONS DURING THAT TIME. DUE TO THIS
HAVE LEFT WEDNESDAY NIGHT INTO THURSDAY DRY AT THIS POINT AND WILL
CONTINUE TO EVALUATE WITH ADDITIONAL MODEL RUNS.
&&
.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
THE PRIMARY CONCERN FOR AVIATION TODAY WILL BE AN AREA OF SNOW
SHOWERS...FORECAST TO MOVE THROUGH THE TAF SITES OVER THE NEXT
6-9 HOURS. UPSTREAM CONDITIONS SUGGEST THAT THESE SNOW SHOWERS
WILL BE ALMOST CERTAIN TO BRING IFR CONDITIONS TO THE TAF
SITES...WITH VISIBILITIES BEING BRIEFLY AND SHARPLY REDUCED.
CEILINGS WILL ALSO GET INTO THE IFR RANGE...AND SOME BRIEF LIFR
CONDITIONS MAY BE POSSIBLE IF A VERY HEAVY SNOW SHOWER HAPPENS TO
PASS OVER AN AIRPORT.
FROM LATE MORNING THROUGH AFTERNOON...WINDS WILL SHIFT TO THE WEST
AS A FRONT PASSES THROUGH THE AREA. THESE WINDS WILL GUST TO AROUND
20 KNOTS. SOME SNOW SHOWERS WILL CONTINUE...THOUGH GENERALLY OF A
LIGHTER VARIETY...WITH PREVAILING CONDITIONS LIKELY TO REMAIN IN
THE MVFR RANGE.
ALTHOUGH SOME BREAKS IN THE CLOUDS WILL BE POSSIBLE DURING THE
EVENING...ESPECIALLY AT THE CINCINNATI TAF SITES...MVFR CEILINGS
ARE EXPECTED TO PERSIST THROUGH THE OVERNIGHT HOURS AND INTO
SATURDAY MORNING.
OUTLOOK...MVFR CONDITIONS WILL REMAIN OCCASIONALLY POSSIBLE
THROUGH SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
OHZ070>072-077>080.
KY...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
KYZ089>099.
IN...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
INZ066-073>075-080.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...JGL
SHORT TERM...HICKMAN
LONG TERM...NOVAK
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
645 AM EST FRI JAN 17 2014
.SYNOPSIS...
AN ARCTIC COLD FRONT WILL PUSH EAST ACROSS THE REGION TODAY. WEAK
SURFACE RIDGING IS THEN EXPECTED TO BUILD BRIEFLY INTO THE AREA
TONIGHT AND EARLY ON SATURDAY. A CLIPPER SYSTEM WILL THEN RAPIDLY
SPREAD SNOW BACK INTO THE AREA SATURDAY AFTERNOON AND NIGHT.
SURFACE RIDGING WILL PUSH BACK INTO THE AREA ON SUNDAY IN THE WAKE
OF THE CLIPPER SYSTEM. ANOTHER ARCTIC COLD FRONT WILL FOLLOW ON
MONDAY BRINGING A RETURN OF VERY COLD AIR FOR THE MIDDLE OF NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOOKING AT THE LATEST RADAR TRENDS...PCPN MAINLY IN THE FORM OF
SNOW SHOWERS...WAS CONGEALING TOGETHER WEST AND SOUTHWEST OF THE
CWFA. THE LATEST NAM-WRF AND RAP ARE NOW INDICATING STRONGER LOW
LEVEL CONVERGENCE MOVING INTO THE WESTERN PARTS OF THE CWFA THIS
MORNING...RESULTING IN HIGHER MODEL QPF VALUES. HAVE TRENDED QPF
AMOUNTS UPWARD IN THESE AREAS...ALTHOUGH NOT AS HIGH AS THE MODELS
SUGGEST. THIS ALLOWS FOR SNOWFALL AMOUNTS TO RANGE BETWEEN 1 AND 2
INCHES IN THE WESTERN ZONES WITH UP TO AN INCH ELSEWHERE. HAVE
UPDATED THE SPS TO INCLUDE THIS NEW THINKING. WILL CONTINUE TO
MONITOR RADAR TRENDS AND MODELS SHOULD AN ADVISORY HEADLINE BE
NEEDED IF AMOUNTS LOOK TO BE HIGHER THAN CURRENTLY FORECAST.
REMAINDER OF THE DISCUSSION IS STILL GOOD BELOW.
PREVIOUS DISCUSSION--->
HAVE LEANED MORE TOWARD HIGHER RES MODELS FOR TODAYS FORECAST.
AN ARCTIC COLD FRONT WILL PUSH EAST ACROSS THE REGION THIS MORNING
INTO THE EARLY AFTERNOON HOURS. MODELS SUGGEST THAT A WEAK SFC LOW
WILL DEVELOP ALONG THIS FRONT. THIS SFC LOW WILL PROVIDE AN AXIS
OF LOW LEVEL CONVERGENCE FOR SNOW SHOWERS TO DEVELOP ON. AS A
RESULT...IT LOOKS LIKE THE ENTIRE FORECAST AREA SHOULD SEE A
PERIOD OF SNOW SHOWERS AHEAD AND ALONG THE FRONT AS IT MOVES EAST.
WARMER AIR BEING DRAWN INTO THE REGION AHEAD OF THE COLD FRONT MAY
ALLOW SOME RAIN TO BRIEFLY MIX IN OUR EASTERN ZONES. HOWEVER...THE
WET BULB EFFECT MAY PREVENT THIS FROM HAPPENING SO HAVE KEPT PTYPE
ALL SNOW AT THIS TIME. SNOW ACCUMULATION...UP TO AN INCH...WILL
OCCUR IN A SHORT PERIOD OF TIME. THIS AMOUNT...ALONG WITH REDUCED
VISIBILITIES IN SOME OF THE MODERATE TO LOCALLY HEAVY SNOW
SHOWERS...WILL POSE A TRAVEL THREAT FOR THE ENTIRE REGION TODAY.
HAVE THUS ISSUES AN SPS HIGHLIGHTING THIS THREAT. A WELL DEFINED
S/WV (VORT MAX) ALOFT WILL PUSH ACRS THE AREA THIS AFTERNOON/THIS
EVENING IN THE WAKE OF THE FRONT. THIS FEATURE...ALONG WITH
STEEPING LOW LEVEL LAPSE RATES AND SOME WEAK LOW LEVEL SPEED
CONVERGENCE SHOULD KEEP SNOW SHOWER ACTIVITY GOING SOME BEHIND THE
ARCTIC FRONT. THIS ACTIVITY...HOWEVER...SHOULD BE LIGHTER IN
NATURE WITH LITTLE ADDITIONAL ACCUMULATION EXPECTED.
TEMPERATURES WILL BE TRICKY TODAY GIVEN SOME WAA THIS MORNING
AHEAD OF THE FRONT WITH TEMPERATURES TUMBLING IN THE WAKE OF THE
FRONT. EVEN THE HIGH RES MODELS ARE HAVING A HARD TIME CAPTURING
CURRENT CONDITIONS. HIGHS SHOULD RANGE FROM THE MID 20S NW TO THE
MID 30S SE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
EMBEDDED S/WV (VORT MAX) WILL EXIT TO THE NE OF THE REGION THIS
EVENING. AS IT DOES...SNOW SHOWER ACTIVITY SHOULD WANE FROM WEST
TO EAST. WEAK SURFACE RIDGING IS THEN EXPECTED TO BUILD INTO THE
OHIO VALLEY OVERNIGHT. LOWS WILL BOTTOM OUT IN THE 10 TO 15 DEGREE
RANGE BY SATURDAY MORNING.
MODELS ARE IN DECENT AGREEMENT IN TERMS OF A CLIPPER SYSTEM TO
AFFECT OUR AREA LATER SATURDAY AFTERNOON AND NIGHT. HAVE USED A
BLEND OF THE GFS/ECMWF GIVEN BETTER SIMILARITY TO SYNOPTIC
FEATURES. SURFACE RIDGE WILL RAPIDLY MOVE EAST ON SATURDAY AS THE
CLIPPER DIVES SE FROM THE NRN PLAINS TO THE OHIO VALLEY BY
SATURDAY NIGHT. GOOD WAA/ISENTROPIC LIFT WILL ACCOMPANY THIS
SYSTEM AS IT ENTERS OUR AREA LATE SATURDAY AFTERNOON AND EVENING.
THEREAFTER...MODELS SHOW A FAIRLY RAPID WEAKENING TO THE SYSTEM AS IT
SHIFTS EAST OVERNIGHT...BECOMING ABSORBED WITH A STRONGER...LARGE
SCALE UPR LVL LOW DIGGING INTO QUEBEC. HAVE GONE WITH CATEGORICAL
POPS ALL LOCATIONS. 1 TO 2 INCHES OF SNOW LOOKS FAIRLY REASONABLE
REGION WIDE WITH PERHAPS SOME 3 INCH AMOUNTS POSSIBLE NORTH OF THE
CINCINNATI AND JUST SOUTH OF DAYTON PER LATEST MODEL RUNS. WILL
CONTINUE TO HIGHLIGHT THIS SYSTEM IN THE HWO. TEMPERATURES
SATURDAY INTO SATURDAY NIGHT WILL SHOW WARMING DUE TO WAA AHEAD OF
THE CLIPPER FOLLOWED BY A LITTLE COOL DOWN TOWARD SUNRISE SUNDAY.
ON SUNDAY...SFC RIDGING WILL MOVE INTO THE OHIO VALLEY. WE SHOULD
SEE CLOUDS SCATTERED BY AFTERNOON...ALLOWING FOR SOME SUNSHINE.
REGION WILL BE CAUGHT BETWEEN SFC RIDGE AND ANOTHER ARCTIC COLD
FRONT TO OUR NORTH AND NORTHWEST. THE PRESSURE GRADIENT BETWEEN
THESE TWO FEATURES WILL RESULT IN BREEZY CONDITIONS BUT WILL ALSO
ALLOW FOR SOME WARMING.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A COLD FRONT WILL DROP DOWN INTO THE FA ON MONDAY. MOISTURE IS
LIMITED WITH THIS FEATURE AND THEREFORE LIMITED SNOWFALL CHANCES
AT THIS TIME TO A SLIGHT CHANCE. MUCH COLDER AIR WILL BE USHERED
INTO THE AREA HOWEVER FOR THE REMAINDER OF THE LONG TERM TIME
FRAME.
THE LOWEST TEMPERATURES ARE EXPECTED TO OCCUR WEDNESDAY MORNING AND
THURSDAY MORNING. WIND CHILL VALUES WEDNESDAY MORNING WILL BE NEAR
WIND CHILL ADVISORY CRITERIA.
SOME LAKE EFFECT SNOW SHOWERS WILL BE POSSIBLE ACROSS PORTIONS OF
THE FA MONDAY NIGHT INTO TUESDAY EVENING. AFTER THIS TIME WENT WITH
DRY CONDITIONS ACROSS THE FA. THE GFS IS HINTING AT A DISTURBANCE
MOVING THROUGH THE FA WEDNESDAY NIGHT INTO THURSDAY MORNING HOWEVER
THERE HAS BEEN QUITE A BIT OF RUN TO RUN DIFFERENCES DURING THIS
TIME AND THE ECMWF HAS DRY CONDITIONS DURING THAT TIME. DUE TO THIS
HAVE LEFT WEDNESDAY NIGHT INTO THURSDAY DRY AT THIS POINT AND WILL
CONTINUE TO EVALUATE WITH ADDITIONAL MODEL RUNS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
THE PRIMARY CONCERN FOR AVIATION TODAY WILL BE AN AREA OF SNOW
SHOWERS...FORECAST TO MOVE THROUGH THE TAF SITES OVER THE NEXT
6-9 HOURS. UPSTREAM CONDITIONS SUGGEST THAT THESE SNOW SHOWERS
WILL BE ALMOST CERTAIN TO BRING IFR CONDITIONS TO THE TAF
SITES...WITH VISIBILITIES BEING BRIEFLY AND SHARPLY REDUCED.
CEILINGS WILL ALSO GET INTO THE IFR RANGE...AND SOME BRIEF LIFR
CONDITIONS MAY BE POSSIBLE IF A VERY HEAVY SNOW SHOWER HAPPENS TO
PASS OVER AN AIRPORT.
FROM LATE MORNING THROUGH AFTERNOON...WINDS WILL SHIFT TO THE WEST
AS A FRONT PASSES THROUGH THE AREA. THESE WINDS WILL GUST TO AROUND
20 KNOTS. SOME SNOW SHOWERS WILL CONTINUE...THOUGH GENERALLY OF A
LIGHTER VARIETY...WITH PREVAILING CONDITIONS LIKELY TO REMAIN IN
THE MVFR RANGE.
ALTHOUGH SOME BREAKS IN THE CLOUDS WILL BE POSSIBLE DURING THE
EVENING...ESPECIALLY AT THE CINCINNATI TAF SITES...MVFR CEILINGS
ARE EXPECTED TO PERSIST THROUGH THE OVERNIGHT HOURS AND INTO
SATURDAY MORNING.
OUTLOOK...MVFR CONDITIONS WILL REMAIN OCCASIONALLY POSSIBLE
THROUGH SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...NOVAK
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
528 AM EST FRI JAN 17 2014
.SYNOPSIS...
AN ARCTIC COLD FRONT WILL PUSH EAST ACROSS THE REGION TODAY. WEAK
SURFACE RIDGING IS THEN EXPECTED TO BUILD BRIEFLY INTO THE AREA
TONIGHT AND EARLY ON SATURDAY. A CLIPPER SYSTEM WILL THEN RAPIDLY
SPREAD SNOW BACK INTO THE AREA SATURDAY AFTERNOON AND NIGHT.
SURFACE RIDGING WILL PUSH BACK INTO THE AREA ON SUNDAY IN THE WAKE
OF THE CLIPPER SYSTEM. ANOTHER ARCTIC COLD FRONT WILL FOLLOW ON
MONDAY BRINGING A RETURN OF VERY COLD AIR FOR THE MIDDLE OF NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOOKING AT THE LATEST RADAR TRENDS...PCPN MAINLY IN THE FORM OF
SNOW SHOWERS...WAS CONGEALING TOGETHER WEST AND SOUTHWEST OF THE
CWFA. THE LATEST NAM-WRF AND RAP ARE NOW INDICATING STRONGER LOW
LEVEL CONVERGENCE MOVING INTO THE WESTERN PARTS OF THE CWFA THIS
MORNING...RESULTING IN HIGHER MODEL QPF VALUES. HAVE TRENDED QPF
AMOUNTS UPWARD IN THESE AREAS...ALTHOUGH NOT AS HIGH AS THE MODELS
SUGGEST. THIS ALLOWS FOR SNOWFALL AMOUNTS TO RANGE BETWEEN 1 AND 2
INCHES IN THE WESTERN ZONES WITH UP TO AN INCH ELSEWHERE. HAVE
UPDATED THE SPS TO INCLUDE THIS NEW THINKING. WILL CONTINUE TO
MONITOR RADAR TRENDS AND MODELS SHOULD AN ADVISORY HEADLINE BE
NEEDED IF AMOUNTS LOOK TO BE HIGHER THAN CURRENTLY FORECAST.
REMAINDER OF THE DISCUSSION IS STILL GOOD BELOW.
PREVIOUS DISCUSSION--->
HAVE LEANED MORE TOWARD HIGHER RES MODELS FOR TODAYS FORECAST.
AN ARCTIC COLD FRONT WILL PUSH EAST ACROSS THE REGION THIS MORNING
INTO THE EARLY AFTERNOON HOURS. MODELS SUGGEST THAT A WEAK SFC LOW
WILL DEVELOP ALONG THIS FRONT. THIS SFC LOW WILL PROVIDE AN AXIS
OF LOW LEVEL CONVERGENCE FOR SNOW SHOWERS TO DEVELOP ON. AS A
RESULT...IT LOOKS LIKE THE ENTIRE FORECAST AREA SHOULD SEE A
PERIOD OF SNOW SHOWERS AHEAD AND ALONG THE FRONT AS IT MOVES EAST.
WARMER AIR BEING DRAWN INTO THE REGION AHEAD OF THE COLD FRONT MAY
ALLOW SOME RAIN TO BRIEFLY MIX IN OUR EASTERN ZONES. HOWEVER...THE
WET BULB EFFECT MAY PREVENT THIS FROM HAPPENING SO HAVE KEPT PTYPE
ALL SNOW AT THIS TIME. SNOW ACCUMULATION...UP TO AN INCH...WILL
OCCUR IN A SHORT PERIOD OF TIME. THIS AMOUNT...ALONG WITH REDUCED
VISIBILITIES IN SOME OF THE MODERATE TO LOCALLY HEAVY SNOW
SHOWERS...WILL POSE A TRAVEL THREAT FOR THE ENTIRE REGION TODAY.
HAVE THUS ISSUES AN SPS HIGHLIGHTING THIS THREAT. A WELL DEFINED
S/WV (VORT MAX) ALOFT WILL PUSH ACRS THE AREA THIS AFTERNOON/THIS
EVENING IN THE WAKE OF THE FRONT. THIS FEATURE...ALONG WITH
STEEPING LOW LEVEL LAPSE RATES AND SOME WEAK LOW LEVEL SPEED
CONVERGENCE SHOULD KEEP SNOW SHOWER ACTIVITY GOING SOME BEHIND THE
ARCTIC FRONT. THIS ACTIVITY...HOWEVER...SHOULD BE LIGHTER IN
NATURE WITH LITTLE ADDITIONAL ACCUMULATION EXPECTED.
TEMPERATURES WILL BE TRICKY TODAY GIVEN SOME WAA THIS MORNING
AHEAD OF THE FRONT WITH TEMPERATURES TUMBLING IN THE WAKE OF THE
FRONT. EVEN THE HIGH RES MODELS ARE HAVING A HARD TIME CAPTURING
CURRENT CONDITIONS. HIGHS SHOULD RANGE FROM THE MID 20S NW TO THE
MID 30S SE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
EMBEDDED S/WV (VORT MAX) WILL EXIT TO THE NE OF THE REGION THIS
EVENING. AS IT DOES...SNOW SHOWER ACTIVITY SHOULD WANE FROM WEST
TO EAST. WEAK SURFACE RIDGING IS THEN EXPECTED TO BUILD INTO THE
OHIO VALLEY OVERNIGHT. LOWS WILL BOTTOM OUT IN THE 10 TO 15 DEGREE
RANGE BY SATURDAY MORNING.
MODELS ARE IN DECENT AGREEMENT IN TERMS OF A CLIPPER SYSTEM TO
AFFECT OUR AREA LATER SATURDAY AFTERNOON AND NIGHT. HAVE USED A
BLEND OF THE GFS/ECMWF GIVEN BETTER SIMILARITY TO SYNOPTIC
FEATURES. SURFACE RIDGE WILL RAPIDLY MOVE EAST ON SATURDAY AS THE
CLIPPER DIVES SE FROM THE NRN PLAINS TO THE OHIO VALLEY BY
SATURDAY NIGHT. GOOD WAA/ISENTROPIC LIFT WILL ACCOMPANY THIS
SYSTEM AS IT ENTERS OUR AREA LATE SATURDAY AFTERNOON AND EVENING.
THEREAFTER...MODELS SHOW A FAIRLY RAPID WEAKENING TO THE SYSTEM AS IT
SHIFTS EAST OVERNIGHT...BECOMING ABSORBED WITH A STRONGER...LARGE
SCALE UPR LVL LOW DIGGING INTO QUEBEC. HAVE GONE WITH CATEGORICAL
POPS ALL LOCATIONS. 1 TO 2 INCHES OF SNOW LOOKS FAIRLY REASONABLE
REGION WIDE WITH PERHAPS SOME 3 INCH AMOUNTS POSSIBLE NORTH OF THE
CINCINNATI AND JUST SOUTH OF DAYTON PER LATEST MODEL RUNS. WILL
CONTINUE TO HIGHLIGHT THIS SYSTEM IN THE HWO. TEMPERATURES
SATURDAY INTO SATURDAY NIGHT WILL SHOW WARMING DUE TO WAA AHEAD OF
THE CLIPPER FOLLOWED BY A LITTLE COOL DOWN TOWARD SUNRISE SUNDAY.
ON SUNDAY...SFC RIDGING WILL MOVE INTO THE OHIO VALLEY. WE SHOULD
SEE CLOUDS SCATTERED BY AFTERNOON...ALLOWING FOR SOME SUNSHINE.
REGION WILL BE CAUGHT BETWEEN SFC RIDGE AND ANOTHER ARCTIC COLD
FRONT TO OUR NORTH AND NORTHWEST. THE PRESSURE GRADIENT BETWEEN
THESE TWO FEATURES WILL RESULT IN BREEZY CONDITIONS BUT WILL ALSO
ALLOW FOR SOME WARMING.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A COLD FRONT WILL DROP DOWN INTO THE FA ON MONDAY. MOISTURE IS
LIMITED WITH THIS FEATURE AND THEREFORE LIMITED SNOWFALL CHANCES
AT THIS TIME TO A SLIGHT CHANCE. MUCH COLDER AIR WILL BE USHERED
INTO THE AREA HOWEVER FOR THE REMAINDER OF THE LONG TERM TIME
FRAME.
THE LOWEST TEMPERATURES ARE EXPECTED TO OCCUR WEDNESDAY MORNING AND
THURSDAY MORNING. WIND CHILL VALUES WEDNESDAY MORNING WILL BE NEAR
WIND CHILL ADVISORY CRITERIA.
SOME LAKE EFFECT SNOW SHOWERS WILL BE POSSIBLE ACROSS PORTIONS OF
THE FA MONDAY NIGHT INTO TUESDAY EVENING. AFTER THIS TIME WENT WITH
DRY CONDITIONS ACROSS THE FA. THE GFS IS HINTING AT A DISTURBANCE
MOVING THROUGH THE FA WEDNESDAY NIGHT INTO THURSDAY MORNING HOWEVER
THERE HAS BEEN QUITE A BIT OF RUN TO RUN DIFFERENCES DURING THIS
TIME AND THE ECMWF HAS DRY CONDITIONS DURING THAT TIME. DUE TO THIS
HAVE LEFT WEDNESDAY NIGHT INTO THURSDAY DRY AT THIS POINT AND WILL
CONTINUE TO EVALUATE WITH ADDITIONAL MODEL RUNS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE SPREADING INTO THE TAF SITES...WITH SOME MVFR
CEILINGS EXPECTED FOR THE NEXT FEW HOURS. HOWEVER...RESTRICTIONS
TO AVIATION CONDITIONS WILL ARRIVE AGAIN ON FRIDAY MORNING. SNOW
WILL MOVE INTO THE AREA FROM WEST TO EAST...PROVIDING PREVAILING
MVFR CONDITIONS...WITH SOME HEAVIER SNOW SHOWERS DROPPING
VISIBILITIES TO IFR.
AS THIS SNOW MOVES THROUGH THE AREA...WINDS WILL SHIFT TO THE
WEST...AND PICK UP IN INTENSITY (WITH GUSTS OF AROUND 20 KNOTS).
CONDITIONS APPEAR FAVORABLE FOR CONTINUING SNOW SHOWERS GOING INTO
THE AFTERNOON...WITH MVFR CEILINGS AND VISIBILITIES.
BY EVENING...THE CEILINGS ARE EXPECTED TO SCATTER OUT...AS WINDS
GRADUALLY DIMINISH IN INTENSITY.
OUTLOOK...MVFR CONDITIONS WILL REMAIN OCCASIONALLY POSSIBLE
THROUGH SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...NOVAK
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
615 AM CST FRI JAN 17 2014
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND SATURDAY
ISSUED AT 417 AM CST FRI JAN 17 2014
SURFACE AND UPPER SYSTEM PULLING OUT OF AREA EARLY
THIS MORNING. DRIER AIR WORKING INTO WESTERN HALF OF STATE WITH
CEILINGS IMPROVING...SNOW ENDING. LIGHT SNOW CONTINUES OVER MUCH
OF CWA ATTM WITH PERSISTENT BANDING FEATURE NOW LOCATED FROM GRB
INTO ISW. THOUGH RADAR RETURNS LOOK MORE OMINOUS...SURFACE REPORTS
HAVE VISBYS MAINLY 2 MILES OR ABOVE. PREVIOUS FORECAST OF INCH
OVERNIGHT LOOKS TO BE HOLDING OUTSIDE OF LES REGION. MODELS SHOW
THIS TREND CONTINUING WITH BAND TAKING ON A NE TO SW ORIENTATION
AND EXITING REGION THIS AFTERNOON. GIVEN CURRENT TRENDS...LESS
THAN AN INCH OF FURTHER ACCUMULATION EXPECTED. QUESTION FOR THE DAY
IS TEMPERATURES...WITH CURRENT WARMING TREND OVER THE NORTHERN CWA
AS TEMPERATURES ARE CURRENTLY IN THE UPPER TEENS TO LOW 20S. HAVE
TRENDED HIGH TEMPS TOWARDS RAP MODEL BRINGING TODAYS MAX TEMPS UP...WITH
SOME LIKELY BEING REACHED EARLY THIS MORNING.
SURFACE RIDGE MOVES OVER STATE TONIGHT. CLEARING AND LIGHT
WINDS...WILL ALLOW TEMPS TO DROP SIGNIFICANTLY BEFORE MORE CLOUDS
MOVE IN AND WAA BEGINS DURING THE SECOND HALF OF NIGHT. TONIGHTS TEMPS
WILL LIKELY NEED ANOTHER LOOK AS MODEL TRENDS THIS RUN HAVE BEEN
TO PUSH NEXT CLIPPER SYSTEM TRACK FURTHER WEST. MAIN CHANGE THIS
FORECAST WAS TO SLOW TIMING OF PCPN INTO CENTRAL WI AND CUT BACK
ON HOW FAR NORTH AND EAST IT WILL REACH ON SAT.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY
ISSUED AT 417 AM CST FRI JAN 17 2014
UPPER LEVEL FLOW WAS FORECAST TO BE FROM THE NORTH-NORTHWEST DURING
THIS PART OF THE FORECAST...WITH A WEST COAST RIDGE AND A TROUGH
AXIS OVER...OR A LITTLE BIT TO THE EAST OF...WISCONSIN. TIMING OF
CLIPPER SYSTEMS IN THIS FLOW REGIME WILL BE A CHALLENGE FOR THIS
WEEKEND AND THE UPCOMING WEEK.
THERE IS SOME LAKE EFFECT SNOW SHOWER POTENTIAL IN NORTH CENTRAL
WISCONSIN AS COLD AIR PASSES OVER LAKE SUPERIOR...BUT GLERL ICE
CONCENTRATION GRAPHICS SHOWED LITTLE OPEN WATER NORTH AND WEST OF
THE KEWEENAW PENINSULA. HAVE KEPT POPS ON THE LOW SIDE IN NORTH
CENTRAL WISCONSIN BECAUSE OF THIS. MUCH OF NORTHERN LAKE MICHIGAN
REMAINS OPEN SO THERE IS SOME CHANCE FOR LAKE EFFECT SNOW SHOWERS
IN EASTERN WISCONSIN IF WINDS BECOME FAVORABLE IN THAT AREA...BUT
THERE DOES NOT APPEAR TO BE ANYTHING WORTH MORE THAN A LOW END
CHANCE POP AT TIMES.
HAVE A CHANCE FOR SNOW IN THE NORTH ON SATURDAY NIGHT...ASSOCIATED
WITH A DEPARTING CLIPPER. THERE WERE STILL ENOUGH DIFFERENCES
AMONG THE MODELS IN THEIR LOCATION AND TIMING OF QPF MONDAY...SO
LEFT POPS MAINLY IN THE SLIGHT CHANCE CATEGORY. OTHER THAN THESE
SYSTEMS...SLIGHT CHANCE OR LOW END CHANCE POPS DUE TO POSSIBLE
LAKE EFFECT SNOW SHOWERS.
TEMPERATURES SHOULD BE ABOVE NORMAL ON SUNDAY BEFORE THE ARCTIC
FRONT PASSES THROUGH THE AREA. AFTER THAT...EXPECT MUCH COLDER
THAN NORMAL TEMPERATURES. HIGHS ON TUESDAY AND WEDNESDAY WILL BE
CLOSER TO NORMAL LOWS FOR THIS TIME OF YEAR.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 543 AM CST FRI JAN 17 2014
LIGHT SNOW WILL END FROM NORTHWEST TO SOUTHEAST ACROSS THE REGION
TODAY AS LOW PRESSURE PULLS OUT AND DRIER AIR AND HIGH PRESSURE
MOVES IN. THE MORE PERSISTENT SHOWERS THIS MORNING WILL BE OVER
EAST CENTRAL WISCONSIN. MVFR CIGS/VISBYS WITH SHOWERS EXPECTED.
GUSTY NORTH WINDS EXPECTED BY AFTERNOON AS LOW PULLS EAST. VFR
CONDITIONS EXPECTED BY LATE IN THE DAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....TE
LONG TERM......MG
AVIATION.......TE
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND SATURDAY
ISSUED AT 417 AM CST FRI JAN 17 2014
SURFACE AND UPPER SYSTEM PULLING OUT OF AREA EARLY
THIS MORNING. DRIER AIR WORKING INTO WESTERN HALF OF STATE WITH
CEILINGS IMPROVING...SNOW ENDING. LIGHT SNOW CONTINUES OVER MUCH
OF CWA ATTM WITH PERSISTENT BANDING FEATURE NOW LOCATED FROM GRB
INTO ISW. THOUGH RADAR RETURNS LOOK MORE OMINOUS...SURFACE REPORTS
HAVE VISBYS MAINLY 2 MILES OR ABOVE. PREVIOUS FORECAST OF INCH
OVERNIGHT LOOKS TO BE HOLDING OUTSIDE OF LES REGION. MODELS SHOW
THIS TREND CONTINUING WITH BAND TAKING ON A NE TO SW ORIENTATION
AND EXITING REGION THIS AFTERNOON. GIVEN CURRENT TRENDS...LESS
THAN AN INCH OF FURTHER ACCUMULATION EXPECTED. QUESTION FOR THE DAY
IS TEMPERATURES...WITH CURRENT WARMING TREND OVER THE NORTHERN CWA
AS TEMPERATURES ARE CURRENTLY IN THE UPPER TEENS TO LOW 20S. HAVE
TRENDED HIGH TEMPS TOWARDS RAP MODEL BRINGING TODAYS MAX TEMPS UP...WITH
SOME LIKELY BEING REACHED EARLY THIS MORNING.
SURFACE RIDGE MOVES OVER STATE TONIGHT. CLEARING AND LIGHT
WINDS...WILL ALLOW TEMPS TO DROP SIGNIFICANTLY BEFORE MORE CLOUDS
MOVE IN AND WAA BEGINS DURING THE SECOND HALF OF NIGHT. TONIGHTS TEMPS
WILL LIKELY NEED ANOTHER LOOK AS MODEL TRENDS THIS RUN HAVE BEEN
TO PUSH NEXT CLIPPER SYSTEM TRACK FURTHER WEST. MAIN CHANGE THIS
FORECAST WAS TO SLOW TIMING OF PCPN INTO CENTRAL WI AND CUT BACK
ON HOW FAR NORTH AND EAST IT WILL REACH ON SAT.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY
ISSUED AT 417 AM CST FRI JAN 17 2014
UPPER LEVEL FLOW WAS FORECAST TO BE FROM THE NORTH-NORTHWEST DURING
THIS PART OF THE FORECAST...WITH A WEST COAST RIDGE AND A TROUGH
AXIS OVER...OR A LITTLE BIT TO THE EAST OF...WISCONSIN. TIMING OF
CLIPPER SYSTEMS IN THIS FLOW REGIME WILL BE A CHALLENGE FOR THIS
WEEKEND AND THE UPCOMING WEEK.
THERE IS SOME LAKE EFFECT SNOW SHOWER POTENTIAL IN NORTH CENTRAL
WISCONSIN AS COLD AIR PASSES OVER LAKE SUPERIOR...BUT GLERL ICE
CONCENTRATION GRAPHICS SHOWED LITTLE OPEN WATER NORTH AND WEST OF
THE KEWEENAW PENINSULA. HAVE KEPT POPS ON THE LOW SIDE IN NORTH
CENTRAL WISCONSIN BECAUSE OF THIS. MUCH OF NORTHERN LAKE MICHIGAN
REMAINS OPEN SO THERE IS SOME CHANCE FOR LAKE EFFECT SNOW SHOWERS
IN EASTERN WISCONSIN IF WINDS BECOME FAVORABLE IN THAT AREA...BUT
THERE DOES NOT APPEAR TO BE ANYTHING WORTH MORE THAN A LOW END
CHANCE POP AT TIMES.
HAVE A CHANCE FOR SNOW IN THE NORTH ON SATURDAY NIGHT...ASSOCIATED
WITH A DEPARTING CLIPPER. THERE WERE STILL ENOUGH DIFFERENCES
AMONG THE MODELS IN THEIR LOCATION AND TIMING OF QPF MONDAY...SO
LEFT POPS MAINLY IN THE SLIGHT CHANCE CATEGORY. OTHER THAN THESE
SYSTEMS...SLIGHT CHANCE OR LOW END CHANCE POPS DUE TO POSSIBLE
LAKE EFFECT SNOW SHOWERS.
TEMPERATURES SHOULD BE ABOVE NORMAL ON SUNDAY BEFORE THE ARCTIC
FRONT PASSES THROUGH THE AREA. AFTER THAT...EXPECT MUCH COLDER
THAN NORMAL TEMPERATURES. HIGHS ON TUESDAY AND WEDNESDAY WILL BE
CLOSER TO NORMAL LOWS FOR THIS TIME OF YEAR.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1102 PM CST THU JAN 16 2014
LARGE UPPER TROUGH WILL REMAIN SETTLED OVER THE GREAT
LAKES REGION TONIGHT INTO FRIDAY BEFORE PULLING EAST FRIDAY LATE.
A SURFACE LOW CENTERED REMAIN NEARLY STATIONARY OVER NORTHERN LAKE
MICHIGAN. A SURFACE TROUGH EXTENDED BACK TOWARD NORTHERN
WISCONSIN FROM THIS LOW. WHILE LIGHT SNOW WITH MVFR CIGS WILL
CONTINUE UNDER THE UPPER TROUGH...MORE WIDESPREAD MVFR CIGS AND
VSBYS WITH ISOLATED IFR CONDITIONS CAN BE EXPECTED ALONG THIS
SURFACE TROUGH AS IT PIVOTS SOUTH OVERNIGHT. MVFR CONDITIONS
LIKELY TO CONTINUE FOR MOST OF FRIDAY WITH SOME IMPROVEMENT TO VFR
CONDITIONS LATE IN THE DAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....TE
LONG TERM......MG
AVIATION.......
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
948 AM MST FRI JAN 17 2014
.UPDATE...
&&
.SHORT TERM...CURRENT FORECASTS LOOK ON TRACK...WITH SOME MINOR
ADJUSTMENTS TO SKY COVER BASED ON CURRENT CONDITIONS. FAIRLY
STRONG NORTHWEST FLOW ALOFT TO GRADUALLY WEAKEN TODAY AS UPPER
RIDGE BUILDS INTO THE GREAT BASIN. WITH LOWER PRESSURE ACROSS
CENTRAL PLAINS STATES...GUSTY WINDS WILL CONTINUE IN AND NEAR
FOOTHILLS. SPEEDS TO BE MUCH LESS THAN PREVIOUS DAYS...WITH SOME
GUSTS AROUND 40 MPH IN WIND PRONE AREAS. DOWNSLOPE WINDS WILL
HELP WARM TEMPERATURES...ESPECIALLY NEAR THE FOOTHILLS. THERE MAY
BE A BIT OF A WAVE CLOUD ALONG THE FOOTHILLS DURING THE AFTERNOON
AS NOTED BY THE SYNTHETIC SATELLITE IMAGERY WHICH MAY DELAY THE
WARMUP A BIT.
.AVIATION...LIGHT SOUTHERLY WINDS CURRENTLY AT AREA AIRPORTS.
BEGINNING TO SEE WESTERLY WINDS NEAR THE FOOTHILLS WHICH SHOULD
SPREAD ACROSS THE AREA BY 19Z. CURRENT TAFS SHOWING THIS TREND AND
SEEMS REASONABLE. WILL CONTINUE FOR THE UPCOMING ISSUANCE. LATEST
RAP AND HRRR INDICATE WINDS AT KDEN AND KAPA BECOMING EASTERLY
BY 21Z. NOT SURE IF THIS WILL OCCUR DUE TO THE EXPECTED WESTERLY
PUSH...BUT WILL CONTINUE TO MONITOR. DRAINAGE TO THEN PREVAIL BY
03Z. VFR CONTINUING WITH UNLIMITED CEILINGS.
&&
.PREV DISCUSSION... /ISSUED 355 AM MST FRI JAN 17 2014/
..CORRECTION FOR THE PURPOSE OF CLARIFICATION
SHORT TERM...STRONG DEEP LAYER NORTH-NORTHWEST FLOW OVER THE
WESTERN GREAT PLAINS...WHICH INCLUDES EASTERN COLORADO...WILL
CONTINUE TO SHIFT EAST TODAY AS THE PERSISTENT UPPER LEVEL RIDGE
ALONG THE WEST COAST BEGINS ITS EASTWARD MIGRATION OVER THE GREAT
BASIN. WARMING WILL BE SLOW AT FIRST WITH BANDS OF MID AND HIGH
CLOUDS RACING SOUTH OVER THE AREA THIS MORNING. BY THIS AFTERNOON
PRESSURE FALLS ON THE PLAINS WILL STIMULATE WESTERLY/DOWNSLOPE LOW-
LEVEL FLOW WHICH WILL HELP WARM TEMPERATURES ESPLY IN AND NEAR THE
FRONT RANGE FOOTHILLS. SHOULD SEE GUSTY CHINOOK WINDS DEVELOPING IN
THE FOOTHILLS THIS MORNING AND SPREADING ONTO THE NEARBY PLAINS
BEFORE MIDDAY. SPEEDS SHOULD REMAIN WELL BELOW THOSE OBSERVED OVER
THE PAST FEW DAYS...GENERALLY IN THE 15-30KT RANGE. HOWEVER FOR
THOSE AREAS PRONE TO HIGH WINDS SUCH AS AROUND NEDERLAND...
WONDERVU...ELDORADO CANYON...CLEAR CREEK AND COAL CREEK CANYONS AND
THE FOOTHILLS WEST OF BOULDER...COULD SEE WEST WINDS OCCASIONALLY
GUST TO AROUND 40 MPH. HIGHS TODAY WILL GENERALLY BE 3-6DEG F ABOVE
THOSE RECORDED YESTERDAY. ALTHOUGH BREEZY AREAS NEAR THE FOOTHILLS
MAY SEE HIGHS AS MUCH AS 10-12DEGS F WARMER. TONIGHT...WARMING WILL
CONTINUE WITH RISING GEOPOTENTIAL HEIGHTS UNDER GENERALLY CLEAR
SKIES. LOOK FOR A LIGHT DRAINAGE WIND PATTERN TO SET UP SOON AFTER
SUNSET WITH A FLAT PRESSURE GRADIENT ON THE PLAINS. AREAS IN AND
NEAR THE FOOTHILLS HOWEVER MAY CONTINUE TO EXPERIENCE GUSTY CHINOOK
WINDS WHICH WILL RESULT IN MILD OVERNIGHT TEMPERATURES.
LONG TERM...A DRY AND MILD PERIOD THROUGH THE MIDDLE OF NEXT WEEK
WITH HIGH AMPLITUDE RIDGE REMAINING AROUND THE WEST COAST. THE
RESULT OVER COLORADO WILL BE A DECREASING NORTHWEST FLOW PATTERN
THIS WEEKEND ALONG WITH A WARMING TREND FOR BOTH SATURDAY AND
SUNDAY. WARMEST DAY WILL BE SUNDAY WITH READINGS NEAR 60 ACROSS
LOWER ELEVATIONS WITH A VERY DRY AIRMASS IN PLACE. THERE WILL BE
SOME COOLING ON MONDAY AS A WEAK RIPPLE MOVES THROUGH THE FLOW BUT
NO PRECIP IS EXPECTED.
BY LATER NEXT WEEK...THERE IS A WAVE WHICH TRIES TO UNDERCUT THE
RIDGE LATE THURSDAY AND FRIDAY WITH COOLER TEMPERATURES AND
POSSIBLE A CHANCE OF PRECIP. THE GFS IS MORE PRONOUNCED WITH
HIGHER MOISTURE LEVELS WHILE EUROPEAN IS DRIER. THIS PERIOD IS
JUST BEYOND DAY 7 SO WILL ADDRESS THIS MORE IN NEXT UPDATE.
AVIATION...VFR CONDITIONS WILL PREVAIL DURING THE NEXT 24 HOURS.
THE STRONG NORTHERLY FLOW ALOFT OF THE PAST FEW DAYS WILL SHIFT
EAST OF THE AREA TODAY RESULTING IN LIGHTER WINDS...AND A RETURN
TO A MORE FAMILIAR WIND PATTERN WITH DRAINAGE FLOW AT NIGHT AND
EARLY IN THE MORNING...AND LIGHT UPSLOPE/UPVALLEY WINDS DURING THE
LATE MORNING AND AFTERNOON HOURS. HOWEVER...BJC NEAR THE FOOTHILLS
MAY STILL SEE PERIODS OF GUSTY WEST WINDS OF 15-25KTS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....ENTREKIN
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS ALBANY NY
337 PM EST FRI JAN 17 2014
.SYNOPSIS...
A STRONG UPPER LEVEL TROUGH WILL APPROACH THE REGION OVERNIGHT.
THIS WILL PROVIDE THE REGION WITH ANOTHER ROUND OF LIGHT SNOW
DURING THE DAY SATURDAY. ANOTHER DISTURBANCE WILL IMPACT THE
REGION SUNDAY WITH ADDITIONAL SNOW SHOWERS EXPECTED.
THEREAFTER...AN ARCTIC AIR MASS WILL SETTLE ACROSS THE ENTIRE
REGION FOR MOST OF THE UPCOMING WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
H2O VAPOR LOOP ANALYSIS REVEALS A HIGH AMPLITUDE FLOW WITH A RIDGE
OVER WESTERN NOAM...DEEP TROUGH EXTENDING FROM HUDSON BAY INTO THE
GULF OF MEXICO...AND A RIDGE OVER THE CENTRAL ATLANTIC OCEAN. A
CLOSER LOOK SHOWS A RATHER STRONG SHORT WAVE OVER THE OHIO VALLEY
WITH REGIONAL RADARS AT THIS TIME SUGGESTING MAINLY SCATTERED
SHOWERS IN THIS AREA. HOWEVER...ADDITIONAL UPPER SUPPORT WITH A
JET STREAM OVER THE MID ATLANTIC STATES WILL ADD ADDITIONAL
SUPPORT FOR MORE SHOWERS TO DEVELOP THIS EVENING. THESE SHOWERS
WILL EVENTUALLY MIGRATE FROM SOUTH TO NORTH WITH LIFT/OMEGA
INCREASING SOUTH OF I90 OVERNIGHT. THEREFORE...WE WILL SHOW A
GRADUAL INCREASE IN POPS TONIGHT ALONG WITH INCREASING CLOUD
COVER. AS FOR TEMPERATURES...WITH AMPLE BREAKS IN THE OVERCAST
TODAY AND CLOUDS EXPECTED TO INCREASE THIS EVENING...WE WILL SHADE
TOWARD THE WARMER SIDE OF THE GUIDANCE.
AS FOR ACCUMULATIONS OF SNOW...MOST VALUES ARE EXPECTED TO BE AN
INCH OR LESS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
WE BEGIN THIS WEEKEND WITH MAINLY SNOW AS THE AFOREMENTIONED SHORT
WAVE APPROACHES AND MOVES ACROSS THE REGION. THE LATEST RUC13 AND
NCEP MODEL SUITE POINT TOWARD AN ENHANCED BAND OF SNOW LIFTING
FROM SOUTH TO NORTH DURING SATURDAY MORNING PER THE 850-700MB
OMEGA FIELDS. HOWEVER...THE MID LEVEL DRY SLOT ALSO QUICKLY
APPROACHES WHICH SHOULD CUT DOWN ON THE BEST ICE NUCLEI FOR BEST
SNOW FALL RATE POTENTIAL. IN FACT...BUFKIT PROFILES SUGGEST THE
BETTER LIFT WILL OCCUR OUTSIDE OF THE DENDRITIC ZONE SO SNOWFALL
RATES SHOULD REMAIN LOW. DURING THE DAY...THE SNOW WILL BECOME
MORE TERRAIN BASED AS THE UPPER LOW PASSES OVERHEAD AND THE MAIN
SURFACE LOW TRACKS FROM LONG ISLAND AND ACROSS CAPE COD. THE
BETTER DEFORMATION AXIS APPEARS TO REMAIN WEST OF OUR CWFA SO PER
COLLABORATION WITH NEIGHBORING OFFICES...WPC-WWD AND ENSEMBLE
PROBABILITIES...WE WILL WITHHOLD THE MENTION OF HEADLINES AT THIS
TIME AND WORD THE HWO ACCORDINGLY.
THIS SYSTEM WILL QUICKLY DEPART SATURDAY EVENING WITH A NARROW
SHORT WAVE RIDGE AXIS SLIDING OVERHEAD. WHILE MOST OF THE REGION
SHOULD REMAIN RATHER DRY...SOME LAKE EFFECT/ENHANCEMENT DOWNWIND
OF LAKE ONTARIO MAY BRING ADDITIONAL ACCUMULATING SNOWFALL ACROSS
PORTIONS OF THE ADIRONDACKS.
NEXT CLIPPER TYPE SYSTEM APPROACHES FOR SUNDAY WITH AN ADDITIONAL
CHANCE FOR SNOW SHOWERS. THE LAKE WILL CONTINUE TO CONTRIBUTE
ADDITIONAL LOW LEVEL MOISTURE FOR ADDITIONAL SNOWFALL ACROSS
PORTIONS OF THE DACKS BUT INLAND EXTENT AND SHEAR PROFILES SUGGEST
LESS THAN CONFIDENCE TO HOIST ANY HEADLINES AT THIS TIME. IT WILL
BECOME BRISK AS GRADIENT TIGHTENS UP WITH AFTERNOON HIGHS INTO THE
20S AND LOWER 30S.
SUNDAY NIGHT...ARCTIC BOUNDARY APPROACHES WITH ADDITIONAL SNOW
SHOWERS AND POSSIBLE SQUALLS AS LAPSE RATES AT AND BELOW H700
STEEPEN. FURTHERMORE...MIXING LAYER HEIGHTS TOO TAP INTO 30-40KTS
TO MAKE FOR A RATHER BRISK NIGHT. MODEL GUIDANCE ALSO HINTS AT
ANOTHER WAVE DEVELOPING ALONG THE ARCTIC BOUNDARY WHICH COULD
SERVE TO SLOW DOWN THE BOUNDARY ALONG WITH AN INCREASED CHANCE FOR
ACCUMULATING SNOWFALL.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
MUCH OF THE EXTENDED PERIOD WILL BE DOMINATED BY FRIGID...ARCTIC
AIR...WITH LITTLE PRECIPITATION EXPECTED.
AN ARCTIC COLD FRONT WILL PASS THROUGH THE REGION ON MONDAY FROM
NORTHWEST TO SOUTHEAST. SOME SCATTERED SNOW SHOWERS...SNOW
SQUALLS...AND FLURRIES WILL ACCOMPANY THIS BOUNDARY AS IT
CROSSES...ALTHOUGH SNOWFALL WILL BE MINOR DUE TO LIMITED MOISTURE.
MAX TEMPS ON MONDAY WILL RANGE FROM THE TEENS IN THE NW ADIRONDACKS
WHERE THE FRONT WILL BE CROSSING VERY EARLY IN THE DAY TO THE MID TO
UPPER 30S IN THE MID HUDSON VALLEY AND NW CT...WHERE THE FRONT WONT
CROSS TILL LATER IN THE AFTN.
BEHIND THE BOUNDARY...850 HPA TEMPS WILL DROP TO -20 TO -25 DEGREES
C FOR MONDAY NIGHT AND THEY WILL CONTINUE AT THIS LEVEL THROUGH THE
REMAINDER OF THE WEEK. IT WILL BE EXCEPTIONALLY DRY...WITH PWAT
VALUES LESS THAN 0.10 INCHES...WHICH IS WELL BELOW THE
CLIMATOLOGICAL NORMAL VALUES FOR MID TO LATE JANUARY. EXACTLY HOW
COLD IT GETS DURING THIS COLD OUTBREAK WILL DEPEND ON A FEW
FACTORS...SUCH AS HOW CALM THE WINDS CAN GET AT NIGHT AND WHERE
THERE IS FRESH AND DEEP SNOW PACK. FOR NOW...WE WILL FORECAST MAX
TEMPS FOR TUESDAY THROUGH FRIDAY GENERALLY IN THE LOW TO MID TEENS
FOR VALLEY AREAS /SINGLE DIGITS IN THE HIGH TERRAIN/...WITH 0 TO 5
AT NIGHT /BELOW ZERO ACROSS THE HILLS AND MOUNTAINS/. HOWEVER...IT/S
POSSIBLE ITS EVEN COLDER IF IT RADIATES WELL...ESP FOR TUESDAY AND
WED NIGHTS.
LATE IN THE WEEK...THE 12Z ECMWF SHOWS A CLIPPER MOVING ACROSS THE
AREA WITH A REINFORCING SHOT OF COLD AIR FOR THURSDAY NIGHT INTO
FRIDAY...WHICH COULD BRING SOME LIGHT SNOW TO THE REGION. THE ECMWF
HAS BEEN TOO AGGRESSIVE IN DEVELOPING STORMS LATELY...AND WE WILL
FAVOR THE FLATTER AND DRIER 12Z GFS...WHICH FITS WELL WITH THE
LATEST 12Z GEFS. MORE COLD AIR IS SHOWN ON THE MODELS UPSTREAM
ACROSS CENTRAL CANADA...SO IT APPEARS THAT THE BELOW NORMAL TEMPS
WILL CONTINUE INTO NEXT WEEKEND AND FOR THE LATTER PORTION OF THE
MONTH AS WELL.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
VFR FLYING CONDITIONS WILL PREVAIL AT THE TAF SITES THIS AFTERNOON
AND THROUGH MOST OF TONIGHT...BEFORE SNOW SHOWERS ACCOMPANYING A
WEAK AREA OF LOW PRESSURE BRING MVFR CONDITIONS SATURDAY.
THIS AFTERNOON...AFTER AN IFR/MVFR START AT THE TAF SITES THIS
MORNING...VFR FLYING CONDITIONS HAVE RETURNED WITH OCCASIONAL
SCATTERED TO BROKEN STRATOCUMULUS AROUND 6-8 KFT EXPECTED THROUGH
THE REMAINDER OF THE AFTERNOON AT KGFL AND KALB...WITH ONLY FEW TO
SCATTERED STRATOCUMULUS EXPECTED AT KPSF AND KPOU AS WEAK HIGH
PRESSURE BUILDS ACROSS THE REGION. SOUTHERLY WINDS WILL GENERALLY BE
AROUND 5-10 KNOTS.
TONIGHT INTO SATURDAY...AN UPPER-LEVEL DISTURBANCE WILL APPROACH
FROM THE GREAT LAKES REGION HELPING TO DEVELOP A WEAK AREA OF LOW
PRESSURE AT THE SURFACE. AHEAD OF THIS FEATURE THIS EVENING...SKIES
WILL BECOME SCATTERED TO MOSTLY CLEAR FOR A BRIEF PERIOD AS THE HIGH
PRESSURE EXITS TO THE EAST BEFORE INCREASED LOW AND MIDLEVEL
MOISTURE BRINGS A RETURN OF GRADUALLY LOWERING AND THICKENING CLOUDS
DURING THE OVERNIGHT.
SCATTERED LIGHT SNOW SHOWERS WILL BEGIN TO OVERSPREAD THE TAF SITES
FROM SOUTH TO NORTH AFTER 09Z...WITH LIGHT ACCUMULATIONS EXPECTED.
THERE MAY EVEN BE A BRIEF PERIOD OF RAIN MIXED IN WITH THE SNOW AT
KALB AND KPOU AFTER 15Z AND HAVE HIGHLIGHTED THIS POTENTIAL WITH
PROB30 GROUPS AT THIS TIME. WINDS WILL BE LIGHT AND VARIABLE TONIGHT
BEFORE BECOMING SOUTHEASTERLY DURING THE DAY SATURDAY AROUND 5-8
KNOTS.
OUTLOOK...
SATURDAY: HIGH OPERATIONAL IMPACT. LIKELY SN.
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. SLIGHT CHANCE OF
SHSN.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
SUNDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. SLIGHT CHANCE OF SHSN.
MARTIN LUTHER KING JR DAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF
SHSN.
MONDAY NIGHT TO TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.HYDROLOGY...
RIVER AND STREAM LEVELS CONTINUE TO EXHIBIT A SLOW DECLINE FROM
THE RECENT RAINFALL AND SNOW MELT. THROUGH EARLY NEXT WEEK...ONLY
LIGHT PRECIPITATION IN THE FORM OF SNOW IS EXPECTED ACROSS OUR
AREA. THIS PRECIP WILL HAVE LITTLE EFFECT ON AREA RIVERS AND
STREAMS. AS A RESULT...STREAM FLOWS SHOULD GRADUALLY LOWER. COLD
TEMPERATURES RETURNING LATER THIS WEEKEND AND ESPECIALLY NEXT
WEEK...RIVER AND LAKE ICE WILL BEGIN TO REFORM AND STRENGTHEN ONCE
AGAIN.
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...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...IRL
HYDROLOGY...BGM
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
148 PM EST FRI JAN 17 2014
.UPDATE...
ISSUED AT 135 PM EST FRI JAN 17 2014
BANDS OF SNOW SHOWERS ARE STILL ROTATING ACROSS THE REGION AS AN
UPPER LEVEL TROUGH AND SFC COLD FRONT CONTINUE TO WORK ACROSS THE
AREA. TEMPS IN THE FAR EAST ROSE TO NEAR 40...IF NOT ABOVE AHEAD OF
THIS BOUNDARY...BUT INCREASING CLOUDS HAVE LED TO THOSE AREAS COOLING
OFF AND THIS SHOULD OCCUR MORE RAPIDLY LATER IN THE AFTERNOON.
TEMPS HAVE FALLEN INTO THE LOW TO MID 20S OVER MUCH OF CENTRAL KY AND
TEMPS SHOULD BE INTO THE 20S IN MOST LOCATIONS BY EVENING. WITH THE
LOW LEVEL FLOW GRADUALLY BECOMING MORE WESTERLY TO NORTHWESTERLY...
THE MODELS INDICATE THAT THE BANDS OF SNOW SHOWERS SHOULD CONTINUE OFF
AND ON ACROSS THE AREA INTO THE EVENING. ATTM...THE ADVISORY AREAS
REMAIN VALID AS THE SNOW SHOWERS WORK ACROSS THE AREA AND
TEMPERATURES WILL BE DROPPING. SOME SLUSHY OR SNOW COVERED ROADS
SHOULD OCCUR IN SEVERAL LOCATIONS DURING THE EVENING COMMUTE...
ESPECIALLY IN THE SOUTHEAST TWO THIRDS OF THE CWA.
OTHER THAN SOME UPDATES TO HOURLY OBSERVATION TRENDS...NO SIGNIFICANT
CHANGES WERE MADE.
UPDATE ISSUED AT 1039 AM EST FRI JAN 17 2014
SNOW SHOWERS AND SOME ISOLATED SNOW SQUALLS ARE MOVING EAST SLIGHTLY
FASTER THAN THE PREVIOUS FORECAST. WE HAVE OPTED TO GO AHEAD AND
START THE WINTER WEATHER ADVISORY ACROSS THE SOUTHEASTERN PART OF THE
AREA A BIT QUICKER AS A RESULT. SNOW ACCUMULATIONS STILL LOOK GOOD
WITH AROUND AN INCH OR SO ON AVERAGE IN MOST LOCATIONS THROUGH THIS
EVENING. LOCALLY HIGHER AMOUNTS ARE ANTICIPATED GENERALLY ABOVE 2000
FEET NEARER TO VA AND IN ANY MORE PERSISTENT BANDS OF SNOW. ALTHOUGH
THERE WAS SOME THUNDERSNOW IN THE BAND OF SNOW SHOWERS NOW ROTATING
INTO VA AND WV...THE NEXT BANDS OF SNOW SHOWERS ARE NOT AS DEEP IN
THE ATMOSPHERE... AND LIGHTNING APPEARS LESS LIKELY BUT THEY SHOULD
BE MORE WIDESPREAD. HOURLY TEMPS AND DEWPOINTS HAVE ALSO BEEN
FRESHENED UP BASED ON THE LATEST TRENDS.
UPDATE ISSUED AT 620 AM EST FRI JAN 17 2014
DID A QUICK UPDATE TO TAKE THE FIRST ROUND OF SNOW OUT OF THE GRIDS
AND FIRM UP THE TIMING OF THE NEXT BATCH. ALSO FINE TUNED THE SKY AND
NEAR TERM TEMPS/DEWPOINTS. THESE HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 350 AM EST FRI JAN 17 2014
07Z SFC ANALYSIS SHOWS THE LATEST CLIPPER SYSTEM MOVING THROUGH THE
GREAT LAKES. THIS IS PUSHING AN ARCTIC BOUNDARY INTO THE WESTERN
PORTIONS OF THE OHIO VALLEY. AHEAD OF THIS...A DISTURBANCE AT MID
LEVELS HAS SENT A NEW BATCH OF SNOW SHOWERS THROUGH EAST KENTUCKY
WHITENING SOME PLACES UP TO AN INCH AS IT PASSES. AT THE WEATHER
OFFICE WE PICKED UP A QUICK 7 TENTHS OF AN INCH AS ONE OF THOSE BANDS
MOVED THROUGH. TEMPERATURES AROUND FREEZING AND ROAD TEMPERATURES IN
MOST PLACES ABOVE FREEZING WILL LIMIT THE IMPACT FROM THESE SNOW
SHOWERS. OVER THE SOUTHERN PARTS OF THE CUMBERLAND VALLEY THE
DEWPOINTS HAVE COME UP INTO THE LOW TO MID 30S AND THIS IS LEADING TO
MORE OF A RAIN EVENT WITH THIS ROUND RATHER THAN SNOW. IT IS A FINE
LINE...THOUGH...SO WILL CONTINUE THE SPS THAT IS OUT THROUGH 16Z FOR
THAT AREA. DESPITE A FEW HEAVIER BANDS...THE BULK OF THE AREA WILL
SEE AROUND A HALF AN INCH OF ACCUMULATION OR LESS THOUGH DAWN.
SLIGHTLY BETTER TOTALS CAN BE EXPECTED ALONG AND IN THE IMMEDIATE
WAKE OF THE ARCTIC BOUNDARY LATER TODAY.
THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT AS THEY ALL SHOW A
POTENT SHORTWAVE CROSSING THROUGH THE SOUTHERN OHIO VALLEY TODAY
WITHIN THE HEART OF A DEEP TROUGH. THIS WAVE WILL BRING SOME STEEP
LAPSE RATES TO THE LOWER PART OF THE ATMOSPHERE LATER THIS MORNING
AND THROUGH THE AFTERNOON HELPING TO ENHANCE THE LIFT AND SHOWERY
NATURE OF THE SNOW. THIS FEATURE MOVES QUICKLY OFF TO THE NORTHEAST
TONIGHT AS THE LARGER TROUGH TEMPORARILY RETREATS TO THE NORTH.
ACCORDINGLY...HEIGHTS WILL MODERATE THROUGH THE AREA INTO SATURDAY
MORNING. THIS PROCESS IS THEN QUICKLY REVERSED LATER THAT DAY AS THE
NEXT SHARP WAVE DROPS SOUTHEAST THROUGH THE MIDWEST...MAKING ITS RUN
TOWARD THE OHIO VALLEY. WITH THE GENERAL MODEL AGREEMENT AND THE
MESOSCALE NATURE OF THE SNOW BANDS AND ARCTIC BOUNDARY...HAVE LEANED
TOWARD THE HIGHER RESOLUTION HRRR AND NAM12 THROUGH THE SHORT TERM.
SENSIBLE WEATHER WILL FEATURE THE PRE-DAWN SNOW...AND FAR SOUTHERN
KY RAIN...SHOWERS EXITING THE AREA WITH A BIT OF A LULL IN ANY PCPN
ACTIVITY UNTIL AROUND MID MORNING IN THE WEST WHEN THE ARCTIC
BOUNDARY MOVES INTO THE CWA. THIS WILL BRING ANOTHER ROUND OF SNOW
SHOWERS...COLDER TEMPERATURES...AND BRISK WINDS TO THE AREA TODAY.
ALTHOUGH MOISTURE IS LIMITED WITH THIS...STILL EXPECT THE LIFT ALONG
THE FRONT AND STEEP LAPSE RATES BEHIND IT TO SUPPORT SNOW SHOWERS
INTENSE ENOUGH TO ACCUMULATE FOR MOST LOCATIONS...GENERALLY A HALF TO
ONE INCH THROUGH EARLY EVENING. TWO INCHES OR MORE INCHES WILL BE
POSSIBLE IN THE HIGHEST TERRAIN NEAR THE VIRGINA BORDER THROUGH
MIDNIGHT. IN ADDITION TO THE SNOW...BRISK WINDS ACCOMPANYING THE SNOW
WILL LIMIT VISIBILITIES AT TIMES TO A MILE OR LESS...POTENTIALLY
CREATING BRIEF PERIODS OF HAZARDOUS TRAVEL. THE SNOW SHOWERS WILL
TAPER TO FLURRIES AND END FROM WEST TO EAST ON SATURDAY NIGHT WITH
TEMPERATURES PLUMMETING INTO THE TEENS BY DAWN. FOR THE BULK OF THE
DAY SATURDAY THE WX WILL BE QUIET BETWEEN DISTURBANCES. HOWEVER...BY
EVENING THICKER AND LOWER CLOUDS WILL BE ROLLING BACK IN FROM THE
NORTHWEST WITH SOME SNOW POSSIBLE BEFORE DARK IN OUR NORTHWEST
COUNTIES.
FOR THE ARCTIC BOUNDARY MOVING THROUGH THE CWA THIS MORNING AND
AFTERNOON WILL ISSUE AN EXTENSION TO THE WSW TO COVER THE ENTIRE
CWA...LINGERING IT INTO THE LATE EVENING IN THE FAR EAST. THE ONLY
DIFFERENCE FROM THE CURRENT ONE IS THAT THIS EXTENSION WILL NOT GO
INTO EFFECT UNTIL AFTER 15Z.
FOLLOWED A BLEND OF THE DIURNAL FROM NAM12 AND THE CONSSHORT FOR
HOURLY TEMPS WHILE FAVORED THE BCCONSSHORT FOR TD AND WINDS THROUGH
THE FIRST 24 HOURS...STARTING WITH THE CONSALL THEREAFTER AND FOR MAX
AND MIN TEMPS THROUGH SATURDAY. AS FOR POPS...ENDED UP HIGHER THAN
ALL GUIDANCE FOR TODAY THROUGH TONIGHT GIVEN THE LOW QPF NATURE OF
THIS EVENT.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 337 AM EST FRI JAN 17 2014
AN ACTIVE AND VERY PROGRESSIVE EXTENDED PERIOD BEGINS ON SATURDAY
NIGHT WITH A POSITIONED BROAD TROUGH OVER THE NORTHEASTERN CONUS AND
REMAINING THERE FOR THE ENTIRE EXTENDED. BEFORE DELVING INTO THE
SPECIFICS...THE MODELS DO AGREE ON A RIDGE TROUGH LONGWAVE PATTERN
THROUGH THE EXTENDED. THE TRUE FORECAST CHALLENGE FOR THIS PERIOD
FALLS ON HOW THE MODELS HANDLE THE ARRIVAL OF EACH SHORT WAVES THAT
WILL ROTATE DOWN OUT OF CANADA AND INTO THE GREAT LAKES OHIO VALLEY
REGION. THIS COUPLE WITH THE CHALLENGE OF DETERMINING THE MOISTURE
AVAILABLE...WILL BE QUITE A PROBLEM.
THIS IN MIND...WILL STAY CLOSE TO THE MODEL ALL BLEND AND ENSEMBLE
SOLUTIONS AND DECREASING PROBABILITIES WHERE CONFIDENCE IS LOW. THE
FIRST SIGNIFICANT WAVE MOVES THROUGH THE AREA ON SUNDAY. WITH THE
COLDER AIR ALREADY IN PLACE...THE PRECIP TYPE WITH THIS SYSTEM
SHOULD FALL AS SNOW AND THE INSTABILITY THE MODEL PROFILES ARE
SHOWING WOULD INDICATE AT SOME ACCUMULATING SNOWFALL POSSIBLE WITH
TEMPS COLD ENOUGH AND A GOOD SHOT OF OMEGA IN THE SATURATED -10 TO
-20 REGION FOR A GOOD 2 TO 3 HOUR PERIOD ON SUNDAY MORNING. WILL
NEED TO WATCH FOR THIS SYSTEM...ESPECIALLY WITH A FAVORABLE WIND
DIRECTION FOR SOME UP SLOPE ASSISTANCE. MODELS DO HAVE A GOOD BIT
AGREEMENT WITH THIS AND THIS WAVE IS POSSIBLY THE ONLY WAVE TO PUT
SOME CONFIDENCE IN AS AFTER THIS FEATURE MOVES THROUGH...THE MODELS
WAFFLE WITH THE CHARACTERISTICS OF THE SHORTWAVES LATER IN THE
EXTENDED.
AFTER THIS STRONG WAVE ON SUNDAY PUSHES THROUGH...A BUILDING ARCTIC
AIR MASS WILL DIVE SOUTH AS THE SEMI PERMANENT 500 TROUGH OVER THE
NORTHEAST DIGS A BIT FURTHER SOUTH INTO THE SOUTHERN APPALACHIANS.
THIS WILL BRING TEMPS INTO THE 20S FOR HIGHS AND TEENS FOR LOWS BY
TUESDAY AND THROUGH THE REST OF THE EXTENDED. THE FOLLOWING PIECES
OF ENERGY ON TUESDAY AND THURSDAY ARE QUITE WEAK AND EVEN THE EURO
IS INCONSISTENT WITH THESE WAVES AS IT WILL SHIFT THE WAVES ABOUT 1
TO 2 HUNDRED MILES TO THE EAST FROM RUN TO RUN. WITH THIS TYPE OF
INCONSISTENCY...HAVE GONE WITH SLIGHT CHANCE POPS FROM DAY 4 THROUGH
DAY 7. THE COLDER TEMPS EXPECTED THOUGH WILL ASSURE ANY PRECIP
FALLING AFTER DAY 4 WILL BE SNOW. IT IS SOMEWHAT ENCOURAGING THAT
TELECONNECTIONS AT THIS POINT SUPPORT FALLING TEMPS AFTER TUESDAY SO
THAT IS ONE PARAMETER THAT CAN BE COUNTED ON.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 135 PM EST FRI JAN 17 2014
CIGS AND OR VIS WILL DROP TO MVFR OR LOWER IN BANDS OF SNOW
SHOWERS THROUGH THE 21Z TO 2Z PERIOD...WITH SOME OCCASIONAL VIS AND
OR CIGS DOWN TO AIRPORT MINS. AFTER THAT...PREVAILING CIGS AND VIS
SHOULD GRADUALLY IMPROVE INTO THE VFR RANGE AS THE REGION WILL BE IN
A NARROW AREA OF RIDGING AS THE SYSTEM BRINGING THE CURRENT SHSN
DEPARTS AND IN ADVANCE OF THE NEXT SYSTEM APPROACHING FROM THE
NORTHWEST. WINDS WILL GENERALLY OUT OF THE WEST TO NORTHWEST AT 10 TO
AT TIMES 15KT AND SOME GUSTS AS HIGH AS 20 TO 25KT POSSIBLE. WINDS
SHOULD SLACK TO BELOW 10KT DURING THE 22Z TO 3Z PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR KYZ044-
050>052-058>060-068-069-079-080-104-106-108-111-114.
WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR KYZ087-
088-110-113-115-117-118-120.
WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR
KYZ083>086-107-109-112-116-119.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...JP
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1248 PM EST FRI JAN 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 533 AM EST FRI JAN 17 2014
NO CHANGES TO TIMING OF LAKE EFFECT SNOW ADVISORIES ALONG LAKE
SUPERIOR TO THE EAST OF GRAND MARAIS FOR LAKE ENHANCED SNOW AND
BLOWING/DRIFTING SNOW.
SFC LOW IS OVER NORTHERN LAKE MICHIGAN AS OF 10Z. TROUGH EXTENDS
BACK INTO NCNTRL UPR MICHIGAN. WIND SHIFT IS PRESSING SOUTH BTWN BIG
BAY AND MARQUETTE. THUS FAR OVERNIGHT...SNOW AMOUNTS HAVE BEEN IN
THE 3 TO 6 INCH RANGE OVER WEST AND NORTHWEST UPR MICHIGAN. THE MOST
SNOW HAS OCCURRED VCNTY OF IRONWOOD AND BERGLAND. ALSO SAW A BURST
OF HEAVIER SNOW MAKE IT AS FAR SOUTH AS SOUTHERN DELTA COUNTY. RADAR
ALGORITM INDICATED 2 TO 3 INCHES OVERNIGHT IN THE RAPID RIVER AREA.
APPEARS THAT THIS BURST OF SNOW WELL AWAY FM LK SUPERIOR IS SETTLING
DOWN NOW. FINALLY...ANOTHER BIG ISSUE OVER THE WEST AND NORTHWEST
CWA IS BLSN/DRSN THAT IS REDUCING VSBY...ESPECIALLY IN OPEN AREAS
NEAR LAKE SUPERIOR...WHERE KEWEENAW COUNTY SHERIFF REPORTED HEAVY
BLOWING AND DRIFTING SNOW WAS OCCURRING.
WV LOOP SHOWING THAT A SHORTWAVE IS ENHANCING OVER CNTRL UPR
MICHIGAN/SCNTRL LK SUPERIOR SINCE MIDNIGHT. RADAR REFLECTIVITIES
HAVE SHOWN THIS AS WELL WITH MORE 25+ DBZ ECHOES APPEARING OVER
NORTHERN MARQUETTE COUNTY IN THE LAST FEW HOURS. EXPECT AFFECTS OF
SHORTWAVE TO FINISH UP IN THE NEXT FEW HOURS OVER WESTERN CWA WITH
ENHANCEMENT TAPERING OFF THERE. ENHANCEMENT LIKELY WILL LAST WELL
INTO THE MORNING FOR NCNTRL UPR MICHIGAN THOUGH. SNOW AMOUNTS WILL
BE SUPPORTED FURTHER BY STRONGER LOW-LEVEL CONVERGENCE...AFFECTING
NORTHERN MARQUETTE COUNTY INTO WESTERN ALGER COUNTY AS NORTH WINDS
OVER LK SUPERIOR CONVERGE WITH NW WINDS OVER THE LAND AREAS. SNOW
AMOUNTS THROUGH THE DAY SHOULD MAXIMIZE OUT OVER NORTHERN AND
EASTERN MARQUETTE COUNTY...WITH ADDITIONAL SNOWFALL OF 3 TO 6 INCHES
LIKELY OVER PRETTY WIDE AREA. A BIT CONCERNED MAY NEED A WARNING AS
WINDS JUST OFF SFC ARE MAINLY NORTHEAST AND MODELS ARE NOT PICKING
UP ON THAT. ONLY RUC13 SHOWS THIS...BUT NOT UNTIL 14Z. NOT SURE IF
THIS IS SITUATION THAT MODELS ARE TOO SLOW OR FAVORABLE NE UPSLOPE
WILL PERSIST WELL INTO THE DAY. IF IT DOES...SNOW AMOUNTS WILL BE
PUSHING THE 8 INCH/12 HR CRITERIA. BLSN/DRSN ISSUES WILL ALSO
INCREASE AS NORTH WINDS GUST OVER 30 MPH. OPEN AREAS AND AREAS ALONG
LK SUPERIOR WILL BE MOST VULNERABLE TO POOR VSBY. COORIDORS OF SUB
QUARTER MILE VSBY SEEM LIKELY IN THE HEAVIER SNOW AREAS THIS
MORNING. WILL NEED TO WATCH THIS AS WELL. EVENTUALLY AS SHORTWAVE
DROPS MORE ESE...HEAVIER SNOW SHOWERS AND BLSN/DRSN ISSUES WILL
BEGIN TO AFFECT WESTERN ALGER COUNTY. CONTINUED TO HIGHLIGHT
POTENTIAL FOR DIFFICULT TRAVEL ON M-28 LATER THIS MORNING WITH
SNOW/BLSN/DRSN.
ONCE THE SHORTWAVE AND LARGER SCALE TROUGHING SLIDE MAINLY EAST OF
CWA BY LATE THIS AFTN...EXPECT WEATHER TO QUIET DOWN. SOUNDINGS FOR
THIS EVENING EVEN WHERE FLOW BLO 5KFT REMAINS ONSHORE LOOKING MORE
AND MORE HOSTILE FOR NOTHING MORE THAN LGT LAKE EFFECT OR FLURRIES.
KEPT POPS HIGH IN THE SNOWBELTS EAST OF MARQUETTE BUT SNOW AMOUNTS
LOOK MINIMAL. OVER WEST HALF OF UPR MICHIGAN...EXPECT CLEARING SKIES
FOR GOOD PART OF NIGHT UNTIL HIGH CLOUDS INCREASE LATE AHEAD OF
SYSTEM DIGGING DOWN INTO THE NORTHERN PLAINS. SYSTEM HAS TRENDED
FARTHER WEST...SO IMPACTS FM THE CLOUDS MAY END UP BEING LESS AND
LESS. KEPT WITH THEME OF SUB ZERO TEMPS FOR MUCH OF WEST HALF
INTERIOR. THESE TEMPS MAY NEED FURTHER LOWERING IF CLOUDS DO NOT COME
IN AT ALL LATER TONIGHT AS WINDS WILL BE LIGHT AND RADITIONAL COOLING
WILL BE IDEAL.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 436 AM EST FRI JAN 17 2014
NAM SHOWS A 500 MB TROUGH OVER THE GREAT LAKES REGION 12Z SAT WITH A
SHORTWAVE OVER MN. THIS SHORTWAVE DIGS SOUTHEAST INTO ILLINOIS BY
00Z SUN AND LOOKS LIKE IT WILL STAY TO THE WEST OF THE AREA. NAM
BRINGS IN ANOTHER SHORTWAVE THAT WILL AFFECT THE AREA SUN NIGHT.
WITH FIRST SHORTWAVE AND COLD AIR GOING TO THE WEST OF THE
AREA...CUT BACK ON EASTWARD EXTENT OF POPS ON SAT. WITH LESS
COVER...MORE SUNSHINE WILL OCCUR WITH SW WINDS AND WENT A BIT HIGHER
FOR TEMPERATURES. COLD AIR COMES IN SAT NIGHT INTO SUNDAY WITH
TEMPERATURES NOT GOING UP MUCH ON SUNDAY. WENT HIGHEST POPS IN NW
LAKE EFFECT SNOW BELTS. OTHERWISE...NOT MANY CHANGES TO THE GOING
FORECAST.
IN THE EXTENDED...GFS AND ECMWF SHOW A BROAD 500 MB TROUGH OVER THE
CENTRAL U.S. 12Z MON WITH VERY COLD AIR OVER THE AREA AGAIN WITH 850
MB TEMPERATURES DOWN TO -25C OR SO. THIS TROUGH DIGS OVER THE LOWER
GREAT LAKES 12Z TUE AND THE TROUGH CONTINUES WITH THE COLD AIR 12Z
WED WITH THE TROUGH AXIS OVER NEW ENGLAND ON THU. TEMPERATURES WILL
REMAIN BELOW NORMAL THIS FORECAST PERIOD WITH LAKE EFFECT SNOW
CONTINUING THROUGH WED NIGHT. WITH NORTHERLY WINDS...WENT HIGH POPS
IN NORTHERLY AFFECTED LAKE EFFECT SNOW BELTS. DID NOT MAKE TOO MANY
CHANGES TO THE GOING FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1246 PM EST FRI JAN 17 2014
RESIDUAL LAKE EFFECT SNOW SHOWERS WILL CONTINUE TO DIMINISH THROUGH
THE AFTERNOON AND EARLY EVENING FOR ALL THREE SITES. AN APPROACHING
SFC RIDGE FROM THE WEST WILL BACK WINDS AND PUSH ANY REMAINING -SHSN
AND LOW-END MVFR CLOUDS AWAY FROM IWD BY EARLY EVENING...AND CMX AND
SAW OVERNIGHT. HELD ONTO THE LOWER CIGS AND -SHSN AT CMX AND SAW
WELL INTO THE OVERNIGHT HOURS AS WINDS WILL TAKE A WHILE TO BACK
ENOUGH TO REMOVE UPSLOPE INFLUENCE. AS THE SFC RIDGE CROSSES THE
AREA OVERNIGHT...EXPECT LIGHT AND VARIABLE WINDS FOR ALL SITES. VFR
CONDITIONS WILL PERSIST THROUGH MUCH OF SATURDAY...THOUGH MID-LEVEL
CLOUDS ABOVE 5KFT MAY BRUSH IWD SATURDAY MORNING AS LOW PRESSURE
PASSES TO THE SOUTHWEST.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 436 AM EST FRI JAN 17 2014
GALES OVER CENTRAL LAKE SUPERIOR WILL CONTINUE TO WIND DOWN TODAY.
NEXT GALE EVENT LOOKS TO BE SAT NIGHT INTO SUNDAY ACROSS THE EAST
HALF OF LAKE SUPERIOR WITH COLD AIR MOVING ACROSS LAKE SUPERIOR
AGAIN. HEAVY FREEZING SPRAY WILL LAST INTO THIS EVENING ACROSS LAKE
SUPERIOR BEFORE WINDS DIE DOWN ENOUGH TO STOP CAUSING IT. HEAVY
FREEZING SPRAY WILL AGAIN OCCUR SUNDAY INTO TUE SINCE THE INCOMING
AIRMASS WILL BE QUITE COLD. THERE WILL BE SOME HEAVY FREEZING SPRAY
WHERE WAVE ACTION IS HIGHEST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
MIZ006.
LAKE EFFECT SNOW ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
MIZ013.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ005.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL MIDNIGHT EST TONIGHT FOR
LSZ245-248-249-265-266.
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST /NOON CST/ THIS
AFTERNOON FOR LSZ162.
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST THIS EVENING FOR
LSZ244-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...07
AVIATION...KLUBER
MARINE...07
AREA FORECAST DISCUSSION
NWS BUFFALO NY
319 PM EST FRI JAN 17 2014
.SYNOPSIS...
LOW PRESSURE WILL MOVE FROM THE OHIO VALLEY INTO NEW ENGLAND TONIGHT
AND SATURDAY WITH PERIODS OF SNOW PRODUCING SOME MINOR ACCUMULATIONS
ACROSS MUCH OF THE REGION. ANOTHER STRONGER LOW WILL PASS TO THE
NORTH OF THE REGION ON SUNDAY WITH SOME ADDITIONAL LIGHT SNOW AND
STRONG WINDS. SOME LAKE ENHANCED SNOW IS POSSIBLE EAST OF THE LAKES
AS WELL. AN ARCTIC COLD FRONT WILL DROP SOUTH ACROSS THE REGION
SUNDAY NIGHT AND USHER IN THE START OF WELL BELOW AVERAGE
TEMPERATURES FOR ALL OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
SKIES ARE TRYING TO CLEAR ACROSS WESTERN NY THIS AFTERNOON WITHIN A
BRIEF WINDOW OF DRIER AIR. THE ONLY AREAS ABLE TO SEE FULL SUN SO
FAR HAVE BEEN DOWNWIND OF LAKE ERIE ACROSS THE NIAGARA FRONTIER AND
LAKE ERIE SHORELINE. FARTHER INLAND...LOW LEVEL MOISTURE IS ALLOWING
CUMULUS AND STRATOCUMULUS FIELDS TO FILL IN ANY CLEARING. EXPECT THE
SUNSHINE TO BE RESTRICTED TO DOWNWIND OF LAKE ERIE THROUGH MID
AFTERNOON...BUT MAY SPREAD INTO OTHER REGIONS BRIEFLY DURING THE
LATE AFTERNOON AND EARLY EVENING BEFORE CLOUDS INCREASE AGAIN AHEAD
OF THE NEXT SYSTEM.
OUR ATTENTION THEN TURNS TO A POTENT MID LEVEL LOW APPARENT IN WATER
VAPOR IMAGERY OVER THE LOWER OHIO VALLEY EARLY THIS AFTERNOON. SHORT
TERM MODEL GUIDANCE TRACKS THIS SYSTEM ACROSS WESTERN PA AND INTO
NEW ENGLAND TONIGHT AND SATURDAY...WITH SEVERAL SMALLER SCALE
SHORTWAVES AND SPOKES OF STRONG VORTICITY PRODUCING PERIODS OF
ENHANCED LIFT ACROSS OUR REGION. TOTAL SNOW AMOUNTS WILL BE
RELATIVELY MINOR WITH THIS SYSTEM...BUT IT COULD COME IN A FEW QUICK
BURSTS WHICH WILL IMPACT TRAVEL TO SOME EXTENT AND MAKING FORECAST
TIMING DIFFICULT.
MESOSCALE MODEL GUIDANCE INCLUDING THE OPERATIONAL NAM AND TO SOME
EXTENT THE CANADIAN GEM AND HRRR SUGGEST THE FIRST BURST OF SNOW
WILL LIFT FROM SOUTH TO NORTH ACROSS WESTERN NY THIS EVENING. THE
BURST MAY REACH CHAUTAUQUA AND CATTARAUGUS COUNTY BY 23Z-00Z...THEN
LIFT ALMOST DUE NORTH TO THE NIAGARA FRONTIER BY 02Z-03Z BEFORE
LIFTING INTO SOUTHERN ONTARIO AND LAKE ONTARIO BY MIDNIGHT. UPSTREAM
RADARS SHOW THIS FEATURE ALREADY WELL DEFINED IN EASTERN OHIO...SO
THAT GIVES SOME CREDENCE TO THESE HIGH RESOLUTION MODELS. THIS MAY
PRODUCE A QUICK BURST OF AN INCH OR SO OF SNOW IN ABOUT AN HOUR
ACROSS WESTERN NY...ENOUGH TO PRODUCE WIDESPREAD SLIPPERY TRAVEL
ACROSS WESTERN NY.
THIS FIRST BATCH SHOULD BE MAINLY CONFINED TO WESTERN NY. LATER
TONIGHT ANOTHER PERIOD OF ASCENT WILL OVERSPREAD THE REGION AS THE
MAIN MID LEVEL CLOSED LOW APPROACHES. SATURDAY MORNING A WEAK COMMA
HEAD OF LIGHT TO MODERATE SNOW SHOULD DEVELOP ACROSS THE FINGER
LAKES AND WESTERN NY AS THE SHARP MID LEVEL LOW MAXIMIZES ASCENT IN
THAT AREA...AND A SURFACE LOW DEEPENS OVER THE LOWER HUDSON VALLEY
AND SOUTHERN NEW ENGLAND WITH A REGION OF DEFORMATION DEVELOPING ON
ITS NORTHWEST FLANK. EXPECT A STEADY SNOW ACROSS A GOOD PORTION OF
THE AREA SATURDAY MORNING...WITH THE MORE MODERATE RATES FROM THE
FINGER LAKES TO SOUTHERN TUG HILL REGION...INCLUDING COUNTIES ALONG
THE SOUTHEAST SHORE OF LAKE ONTARIO. THIS MAY PRODUCE ADDITIONAL
AMOUNTS OF 2-3 INCHES IN THESE AREAS. ELSEWHERE ACROSS WESTERN NY
AND NEAR THE SAINT LAWRENCE RIVER EXPECT PERIODS OF LIGHTER SNOW
WITH ADDITIONAL AMOUNTS AROUND AN INCH.
BETWEEN THE SEVERAL ROUNDS OF SNOW TONIGHT AND SATURDAY...EXPECT
TOTAL AMOUNTS TO BE 1-2 INCHES ACROSS THE NIAGARA FRONTIER AND NEAR
THE SAINT LAWRENCE...WITH 2-4 INCHES FROM THE WESTERN SOUTHERN TIER
EAST ACROSS THE FINGER LAKES TO OSWEGO COUNTY AND THE SOUTHERN TUG
HILL. THE FAR WESTERN SOUTHERN TIER MAY HAVE LESS SYNOPTIC SNOW THAN
OTHER AREAS...BUT UPSLOPE FLOW AND SOME LAKE ENHANCEMENT SHOULD
BOOST THESE AREAS TO THE 2-4 INCH RANGE AS WELL.
THIS SNOW WILL SLOWLY TAPER OFF TO FLURRIES FROM WEST TO EAST
SATURDAY AFTERNOON...WITH SNOW LINGERING THE LONGEST EAST AND
SOUTHEAST OF LAKE ONTARIO. HIGHS ON SATURDAY WILL RANGE FROM ONLY
AROUND 20 ACROSS THE WESTERN SOUTHERN TIER WHERE MORE COLD AIR WRAPS
IN BEHIND THE CLOSED LOW...TO THE LOWER 30S ACROSS CENTRAL NY AND
THE NORTH COUNTRY.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
SATURDAY NIGHT...AN AREA OF HIGH PRESSURE WILL BEGIN TO NOSE NORTHWARD
BRINGING DRIER AIR AND ALSO BACKING OUR WINDS AROUND TO SOUTHERLY.
THIS SHOULD ALLOW FOR A DRY START TO THE NIGHT SOUTH OF LAKE
ONTARIO...WHILE TO THE EAST OF LAKE ONTARIO A WESTERLY FLOW OVER THE
LAKE WILL CONTINUE LIGHT SNOW SHOWERS...FIRST FROM THE DEPARTING
UPPER LEVEL DISTURBANCE AND THEN SOME WEAK LAKE EFFECT SNOW. THIS
BAND OF SNOW LATER SATURDAY NIGHT SHOULD LIFT NORTHWARD THEN WEAKEN
FURTHER AS SOME DRY AIR GETS ENTRAINED INTO THE SNOWBAND. OVERALL
SEVERAL INCHES OF SNOW WILL FALL FROM THIS BAND...BUT FOR NOW FEEL
THAT TOTALS WILL REMAIN BELOW 4 INCHES/12HRS.
LATER SATURDAY NIGHT SEVERAL SHORTWAVES TO OUR WEST WILL DIVE
SOUTHWARD INTO A LONGWAVE TROUGH AND BRING THE TROUGH ACROSS THE
EASTERN GREAT LAKES REGION LATER SATURDAY NIGHT AND SUNDAY. LIFT
AHEAD OF THIS TROUGH COMBINED WITH ABUNDANT LOW LEVEL MOISTURE
WILL ALLOW FOR LIGHT SYNOPTIC SNOW TO REACH FAR WNY LATE SATURDAY
NIGHT AND THEN EXPAND EASTWARD ACROSS THE REGION ON SUNDAY. WITHIN
THESE SNOW SHOWERS LAKE ENHANCEMENT WILL OCCUR DOWNWIND OF BOTH
LAKES AS A SOUTHWEST FLOW UP BOTH LAKE ERIE AND OVER LAKE ONTARIO
WILL CREATE ADDITIONAL INSTABILITY AND ALLOW FOR ENHANCED SNOW
SHOWERS. WHILE LAKE INDUCED EQUILIBRIUM LEVELS OFF LAKE ERIE ARE ONLY
AROUND 4K FEET...THEY WILL BE GREATER OFF LAKE ONTARIO AND LAKE
SNOWS IN ADDITION TO THE SYNOPTIC SNOWS MAY BRING ADVISORY LEVEL
SNOWS SUNDAY TO THE NORTH COUNTRY.
IN ADDITION TO THE SNOWS ON SUNDAY...IT WILL BECOME RATHER WINDY
WITH SOUTHWEST WINDS INCREASING WITHIN A TIGHTENING SURFACE PRESSURE
GRADIENT. THIS WILL NOT BE YOUR TYPICAL DEEPENING LOW PASSING TO OUR
NORTH AND WEST...BUT RATHER A DEEPENING LOW PASSING TO OUR NORTH
ACROSS SOUTHERN CANADA...ONE THAT WILL BE DRIVING A STRONG ARCTIC
FRONT TOWARDS OUR REGION. WINDS MAY BRIEFLY REACH ADVISORY LEVELS
ACROSS THE NIAGARA FRONTIER IN THE TYPICAL GUSTY AREAS DOWNWIND OF
THE LAKE ON A SOUTHWEST WIND. WINDS MAY ALSO REACH ADVISORY LEVELS
ACROSS JEFFERSON COUNTRY AND THE SAINT LAWRENCE VALLEY...WHICH WILL
BE CLOSER TO THE ISALLOBARIC COUPLET. WINDS COMBINED WITH SNOW WILL
BRING SOME LOWERED VISIBILITIES THROUGH THE DAY.
SUNDAY NIGHT A SHARP ARCTIC FRONT WILL BE DROPPING SOUTHWARD FROM
CANADA FROM THIS DEEPENING AREA OF LOW PRESSURE THAT WILL BE
ADVANCING EASTWARD ACROSS SOUTHERN CANADA. A RIBBON OF ENHANCED LIFT
FROM THIS FRONT COMBINED WITH LOW LEVEL MOISTURE WILL BRING A BAND
OF SNOW SHOWERS...FIRST ACROSS THE SAINT LAWRENCE VALLEY AND
THOUSAND ISLAND REGION EARLY SUNDAY NIGHT...AND DROPPING
SOUTHWARD...REACHING THE SOUTHERN SHORELINE OF LAKE ONTARIO AROUND
MIDNIGHT...AND THEN POINTS SOUTHWARD THROUGH THE REMAINDER OF THE
NIGHT. BEHIND THIS FRONT TEMPERATURES WILL QUICKLY DROP...AND WINDS
VEER TO NORTHWESTERLY. BY THE END OF SUNDAY NIGHT...TEMPERATURES
WILL LIKELY HAVE FALLEN INTO THE LOW SINGLE DIGITS ACROSS THE NORTH
COUNTRY AND TEENS ELSEWHERE.
MONDAY COLD AIR ADVECTION BEHIND THE COLD FRONT WILL RETURN OUR
REGION INTO THE DEEP FREEZE. 850 HPA DROPPING DOWN TO ABOUT -20C
THROUGH THE DAY WILL NOT ALLOW FOR MORNING TEMPERATURES TO IMPROVE
MUCH. HIGHS MONDAY WILL ONLY BE A FEW DEGREES WARMER THAN THE
MORNING READINGS. SOME LIMITED LAKE EFFECT WILL LIKELY ORGANIZE
SNOWS SOUTH OF THE LAKES BEHIND THE ARCTIC FRONT AS NORTHWESTERLY
WINDS ALIGN. DRIER AIR ASSOCIATED WITH THIS COLD AIRMASS WILL LIKELY
HOLD SNOW ACCUMULATIONS MANAGEABLE SOUTH OF THE LAKES. MONDAY NIGHT
INCREASING WIND SHEAR WILL LIKELY BREAK APART ANY REMAINING LAKE
EFFECT SNOW BANDS...WHILE AS WINDS RELAX SOME THROUGH THE NIGHT
TEMPERATURES DROP INTO THE LOW SINGLE DIGITS...AND BELOW ZERO ACROSS
THE TRADITIONALLY COLDER SPOTS IN VALLEYS SOUTH OF LAKE ONTARIO.
ACROSS THE NORTH COUNTRY...OVER A FRESH SNOWPACK TEMPERATURES WILL
BOTTOM OUT...POSSIBLY INTO THE NEGATIVE TEENS MONDAY NIGHT. WINDS
MAY STAY STRONG ENOUGH MONDAY NIGHT TO WARRANT WIND CHILL HEADLINES.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THIS TIME PERIOD WILL FEATURE TEMPERATURES THAT WILL AVERAGE WELL
BELOW NORMAL...WITH THE COLDEST DAYS EXPECTED EARLY IN THE TIME
PERIOD.
TO START THIS TIME PERIOD AN ANOMALOUSLY +2SD RIDGE WILL BE EXTENDED
OVER THE WESTERN HALF OF NOAM WHILE A -1SD TROUGH WILL BE FOUND OVER
EASTERN NOAM. THIS PATTERN...WITH THE RIDGE AXIS EXTENDING TO NEAR
THE ARCTIC CIRCLE WILL ALLOW FOR A ARCTIC AIRMASS TO DROP
SOUTHWARD...FULLY ENTRENCHED OVER THE GREAT LAKES REGION BY THE
START OF THE TIME PERIOD. TEMPERATURES AT 850 HPA WILL PLUMMET TO
AROUND -22C TO -24C TUESDAY BEFORE THE AIRMASS MODIFIES SOME.
THIS COLD AIRMASS WILL ALSO CREATE A FAIR AMOUNT OF LAKE INSTABILITY
FOR THIS TIME OF YEAR WITH LAKE INDUCED EQUILIBRIUM LEVELS CLIMBING
UPWARDS TO 10K FEET OFF BOTH LAKES TUESDAY THROUGH THURSDAY. THIS
WILL KEEP CHANCES FOR SNOW SHOWERS MID WEEK NEAR THE GREAT
LAKES...THOUGH SOME OF THE FINER DETAILS OF WIND DIRECTION ARE STILL
A LITTLE UNCERTAIN AT THIS TIME. WHILE IT MAY BE SNOWY PERIOD NEXT
WEEK...THE DRIER NATURE ASSOCIATED WITH THIS ARCTIC AIRMASS WILL
LIKELY KEEP DAILY SNOW TOTALS MANAGEABLE...WITH NO ONE DAY
SIGNIFICANT ACCUMULATIONS EXPECTED.
AS THE INITIAL COLD AIRMASS MODIFIES AND SHIFTS EASTWARD A RIDGE OF
HIGH PRESSURE WILL EXTEND NORTHWARD ACROSS THE EASTERN GREAT LAKES
REGION. THIS WILL BRING A BRIEF PERIOD OF DRY WEATHER AS LAKE SNOWS
DIMINISH...AND BEFORE THE NEXT ARCTIC FRONT/COLD BLAST THAT WILL
LIKELY REACH US NEXT WEEKEND.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
MAINLY VFR WILL PREVAIL THROUGH THE REST OF THE AFTERNOON ACROSS
MOST OF THE REGION...WITH SOME MVFR CIGS LINGERING ACROSS THE HIGHER
TERRAIN EAST OF LAKE ONTARIO.
A POTENT MID LEVEL DISTURBANCE AND WEAK SURFACE LOW WILL THEN
APPROACH FROM THE OHIO VALLEY LATER THIS EVENING. THIS MAY PRODUCE A
QUICK BURST OF MODERATE SNOW ACROSS WESTERN NY FOR AN HOUR OR TWO
WITH VSBY APPROACHING AIRFIELD MINIMUMS BRIEFLY. AFTER THIS INITIAL
BURST OF SNOW...THERE MAY BE A BREAK FOLLOWED BY MORE SNOW LATER
TONIGHT INTO SATURDAY. THE SECOND BATCH OF SNOW SHOULD FOCUS MOST OF
ITS MODERATE SNOW ON THE FINGER LAKES AND CENTRAL NY...WITH LIGHTER
SNOW EXTENDING BACK INTO WESTERN NY AND THE NORTH COUNTRY. EXPECT
PERIODS OF IFR VSBY WITH THIS AS WELL. THE SNOW WILL SLOWLY TAPER
OFF TO FLURRIES FROM WEST TO EAST SATURDAY AFTERNOON WITH IMPROVING
VSBY.
CIGS WILL DROP DOWN TO MVFR WITHIN THE HEAVIER SNOW SHOWERS THIS
EVENING...THEN EXPECT A TREND OF MORE WIDESPREAD MVFR CIGS WITH IFR
ACROSS HIGHER TERRAIN LATE TONIGHT THROUGH SATURDAY AS LOW LEVEL
MOISTURE DEEPENS...AND UPSLOPE FLOW INCREASES.
OUTLOOK...
SUNDAY THROUGH WEDNESDAY...VFR...WITH OCCASIONAL RESTRICTIONS TO
MVFR/IFR IN SCATTERED TO NUMEROUS SNOW SHOWERS.
&&
.MARINE...
PERIODS OF MODERATE SOUTHWEST WINDS WILL CONTINUE ON LAKES ERIE AND
ONTARIO TONIGHT THROUGH SUNDAY MORNING WITH SMALL CRAFT ADVISORY
CONDITIONS MOST OF THE TIME. A STRONGER AREA OF LOW PRESSURE WILL
PASS BY WELL NORTH OF THE REGION ACROSS QUEBEC SUNDAY AFTERNOON AND
SUNDAY NIGHT. A STRONG ARCTIC FRONT ASSOCIATED WITH THIS LOW WILL
PUSH SOUTH AND TIGHTEN THE PRESSURE GRADIENT...ALLOWING FOR WINDS TO
APPROACH OR REACH GALE FORCE. WITH THIS IN MIND...WE HAVE RAISED A
GALE WATCH FOR SUNDAY AND SUNDAY NIGHT ON BOTH LAKES.
&&
.CLIMATE...
THE COLD THAT DEVELOPS NEXT WEEK IS VERY LIKELY TO LAST THROUGH THE
END OF JANUARY AND POSSIBLY INTO EARLY FEBRUARY WITH MOST DAYS
SEEING BELOW AVERAGE OR EVEN WELL BELOW AVERAGE TEMPERATURES.
THE D+11 TOOLS FROM CPC WHICH TAKE A 7 DAY RUNNING MEAN OF THE GEFS
ENSEMBLE MEAN FROM JANUARY 24-30 SHOW A VERY DEEP LONGWAVE TROUGH
OVER EASTERN NORTH AMERICA WITH A SHARP RIDGE ALONG THE WEST COAST
EXTENDING ALL THE WAY NORTH TO ALASKA AND BEYOND TO THE NORTH POLE.
TO SEE SUCH AMPLIFICATION IN A ONE WEEK AVERAGE OF GEFS MEAN 500MB
HEIGHT IS VERY IMPRESSIVE...SINCE IT IS A TIME AVERAGED PRODUCT OF
SOMETHING THAT IS ALREADY AN AVERAGE OF THE VARIOUS ENSEMBLE
MEMBERS. BOTTOM LINE...THIS SHOWS VERY GOOD AGREEMENT AMONGST GEFS
ENSEMBLE MEMBERS FOR A LONG PERIOD OF HIGHLY AMPLIFIED LONGWAVE
FLOW. THE ECMWF ENSEMBLE MEAN ALSO SHOWS A SIMILAR PATTERN.
THE PATTERN SHOWN BY THE ENSEMBLE MEAN IS A STRONG POSITIVE PNA
PATTERN...WELL KNOWN FOR DELIVERING ANY COLD AIR AVAILABLE INTO OUR
PORTION OF NORTH AMERICA. THIS LONGWAVE PATTERN ALSO SUPPORTS THE
POTENTIAL FOR CROSS POLAR FLOW...ALLOWING SIBERIAN AIR TO CROSS THE
POLES AND SPILL INTO NORTHERN CANADA. FROM THERE...THE PATTERN
SUPPORTS PIECES OF THIS COLD MOVING INTO THE NORTHERN TIER OF THE
UNITED STATES FROM THE UPPER MISSISSIPPI VALLEY EAST ACROSS THE
GREAT LAKES AND NEW ENGLAND.
THE D+11 TOOLS ALSO LOOK BACK TO FIND ANALOGS THAT CLOSELY MATCH
THIS 500MB PATTERN TO PAST EVENTS...GIVING THE 10 BEST MATCHES FOR
ANALOG DATES. A LOOK BACK AT SURFACE CONDITIONS DURING THESE ANALOG
DATES SHOW THE VAST MAJORITY OF THEM HAD SURFACE TEMPERATURES OF
15-20 DEGREES BELOW AVERAGE.
TO SUM UP...THE PATTERN STRONGLY SUPPORTS MUCH BELOW AVERAGE
TEMPERATURES MOST OF THE TIME FROM NEXT WEEK THROUGH THE END OF THE
MONTH AND POSSIBLY INTO EARLY FEBRUARY. OF COURSE WITH COLD AIR
COMES LAKE EFFECT POTENTIAL...BUT THE DETAILS WHICH DRIVE LOCATION
AND AMOUNTS ARE NOT APPARENT AT THIS TIME RANGE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...GALE WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR
LEZ020-040-041.
SMALL CRAFT ADVISORY UNTIL 11 AM EST SUNDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY FROM 8 AM TO 10 PM EST SATURDAY FOR
LEZ020.
GALE WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING
FOR LOZ030-042>045-062>065.
SMALL CRAFT ADVISORY FROM 9 AM SATURDAY TO 11 AM EST
SUNDAY FOR LOZ042-043.
SMALL CRAFT ADVISORY FROM 1 PM SATURDAY TO 11 AM EST
SUNDAY FOR LOZ044-045.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...HITCHCOCK
SHORT TERM...THOMAS
LONG TERM...THOMAS
AVIATION...HITCHCOCK
MARINE...HITCHCOCK
CLIMATE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
123 PM EST FRI JAN 17 2014
.SYNOPSIS...
LOW PRESSURE WILL MOVE FROM THE OHIO VALLEY INTO NEW ENGLAND TONIGHT
AND SATURDAY WITH PERIODS OF SNOW PRODUCING SOME MINOR ACCUMULATIONS
ACROSS MUCH OF THE REGION. ANOTHER STRONGER LOW WILL PASS TO THE
NORTH OF THE REGION ON SUNDAY WITH SOME ADDITIONAL LIGHT SNOW AND
STRONG WINDS. SOME LAKE ENHANCED SNOW IS POSSIBLE EAST OF THE LAKES
AS WELL. AN ARCTIC COLD FRONT WILL DROP SOUTH ACROSS THE REGION
SUNDAY NIGHT AND USHER IN THE START OF WELL BELOW AVERAGE
TEMPERATURES FOR ALL OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
SKIES ARE TRYING TO CLEAR ACROSS WESTERN NY THIS AFTERNOON WITHIN A
BRIEF WINDOW OF DRIER AIR. SO FAR ONLY AREAS DOWNWIND OF LAKE ERIE
HAVE CLEARED ACROSS THE NIAGARA FRONTIER AND LAKE ERIE SHORELINE.
FARTHER INLAND...LOW LEVEL MOISTURE IS ALLOWING CUMULUS AND
STRATOCUMULUS FIELDS TO FILL IN ANY CLEARING. EXPECT THE SUNSHINE TO
BE RESTRICTED TO DOWNWIND OF LAKE ERIE THROUGH MID AFTERNOON...BUT
MAY SPREAD INTO OTHER REGIONS BRIEFLY DURING THE LATE AFTERNOON AND
EARLY EVENING BEFORE CLOUDS INCREASE AGAIN AHEAD OF THE NEXT SYSTEM.
OUR ATTENTION THEN TURNS TO A POTENT MID LEVEL LOW APPARENT IN WATER
VAPOR IMAGERY OVER THE LOWER OHIO VALLEY EARLY THIS AFTERNOON. SHORT
TERM MODEL GUIDANCE TRACKS THIS SYSTEM ACROSS WESTERN PA AND INTO
NEW ENGLAND TONIGHT AND SATURDAY...WITH SEVERAL SMALLER SCALE
SHORTWAVES AND SPOKES OF STRONG VORTICITY PRODUCING PERIODS OF
ENHANCED LIFT ACROSS OUR REGION. TOTAL SNOW AMOUNTS WILL BE
RELATIVELY MINOR WITH THIS SYSTEM...BUT IT COULD COME IN A FEW QUICK
BURSTS WHICH WILL IMPACT TRAVEL TO SOME EXTENT AND MAKING FORECAST
TIMING DIFFICULT.
MESOSCALE MODEL GUIDANCE INCLUDING THE OPERATIONAL NAM AND TO SOME
EXTENT THE CANADIAN GEM AND HRRR SUGGEST THE FIRST BURST OF SNOW
WILL LIFT FROM SOUTH TO NORTH ACROSS WESTERN NY THIS EVENING. THE
BURST MAY REACH CHAUTAUQUA AND CATTARAUGUS COUNTY BY 23Z-00Z...THEN
LIFT ALMOST DUE NORTH TO THE NIAGARA FRONTIER BY 02Z-03Z BEFORE
LIFTING INTO SOUTHERN ONTARIO AND LAKE ONTARIO BY MIDNIGHT. UPSTREAM
RADARS SHOW THIS FEATURE ALREADY WELL DEFINED IN EASTERN OHIO...SO
THAT GIVES SOME CREDENCE TO THESE HIGH RESOLUTION MODELS. THIS MAY
PRODUCE A QUICK BURST OF AN INCH OR SO OF SNOW IN ABOUT AN HOUR
ACROSS WESTERN NY...ENOUGH TO PRODUCE WIDESPREAD SLIPPERY TRAVEL
ACROSS WESTERN NY.
THIS FIRST BATCH SHOULD BE MAINLY CONFINED TO WESTERN NY. LATER
TONIGHT ANOTHER PERIOD OF ASCENT WILL OVERSPREAD THE REGION AS THE
MAIN MID LEVEL CLOSED LOW APPROACHES. SATURDAY MORNING A WEAK COMMA
HEAD OF LIGHT TO MODERATE SNOW SHOULD DEVELOP ACROSS THE FINGER
LAKES AND WESTERN NY AS THE SHARP MID LEVEL LOW MAXIMIZES ASCENT IN
THAT AREA...AND A SURFACE LOW DEEPENS OVER THE LOWER HUDSON VALLEY
AND SOUTHERN NEW ENGLAND WITH A REGION OF DEFORMATION DEVELOPING ON
ITS NORTHWEST FLANK. EXPECT A STEADY SNOW ACROSS A GOOD PORTION OF
THE AREA SATURDAY MORNING...WITH THE MORE MODERATE RATES FROM THE
FINGER LAKES TO SOUTHERN TUG HILL REGION...INCLUDING COUNTIES ALONG
THE SOUTHEAST SHORE OF LAKE ONTARIO. THIS MAY PRODUCE ADDITIONAL
AMOUNTS OF 2-3 INCHES IN THESE AREAS. ELSEWHERE ACROSS WESTERN NY
AND NEAR THE SAINT LAWRENCE RIVER EXPECT PERIODS OF LIGHTER SNOW
WITH ADDITIONAL AMOUNTS AROUND AN INCH.
BETWEEN THE SEVERAL ROUNDS OF SNOW TONIGHT AND SATURDAY...EXPECT
TOTAL AMOUNTS TO BE 1-2 INCHES ACROSS THE NIAGARA FRONTIER AND NEAR
THE SAINT LAWRENCE...WITH 2-4 INCHES FROM THE WESTERN SOUTHERN TIER
EAST ACROSS THE FINGER LAKES TO OSWEGO COUNTY AND THE SOUTHERN TUG
HILL. THE FAR WESTERN SOUTHERN TIER MAY HAVE LESS SYNOPTIC SNOW THAN
OTHER AREAS...BUT UPSLOPE FLOW AND SOME LAKE ENHANCEMENT SHOULD
BOOST THESE AREAS TO THE 2-4 INCH RANGE AS WELL.
THIS SNOW WILL SLOWLY TAPER OFF TO FLURRIES FROM WEST TO EAST
SATURDAY AFTERNOON...WITH SNOW LINGERING THE LONGEST EAST AND
SOUTHEAST OF LAKE ONTARIO. HIGHS ON SATURDAY WILL RANGE FROM ONLY
AROUND 20 ACROSS THE WESTERN SOUTHERN TIER WHERE MORE COLD AIR WRAPS
IN BEHIND THE CLOSED LOW...TO THE LOWER 30S ACROSS CENTRAL NY AND
THE NORTH COUNTRY.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
DESPITE THE VERY INTERESTING WEATHER PATTERN...THERE WILL BE LITTLE
ACTUAL WEATHER TO TALK ABOUT ACROSS OUR FORECAST AREA DURING THIS
PERIOD. THE EXCEPTION WILL BE THE POTENTIAL FOR SIGNIFICANT LAKE
EFFECT EAST OF LAKE ONTARIO...BUT LETS LOOK AT THE OVERALL PICTURE
FIRST.
AS ADVERTISED FOR THE PAST SEVERAL DAYS...A STRONG +PNA PATTERN WILL
BE LOCKED IN PLACE DURING THIS PERIOD AS AN ANOMALOUSLY ROBUST RIDGE
WILL EXTEND FROM CALIFORNIA AND BRITISH COLUMBIA UP ACROSS THE NORTH
SEA TO NORTHERN SIBERIA. THIS RIDGE WILL HAVE THE MAGNITUDE OF ONE
THAT DEVELOPS AN AVERAGE OF ONCE EVERY FIVE YEARS OR SO...AND THAT
IS BASED SOLELY ON ITS HGT VALUES AND NOT IN REGARDS TO ITS
PERSISTENCE...WHICH IS EXPONENTIALLY MORE IMPRESSIVE. THIS UNUSUAL
FEATURE WILL CONTINUE TO SUPPLY RECORD WARMTH TO PARTS OF BRITISH
COLUMBIA (THANK GOODNESS THE WINTER OLYMPICS ARE NOT THERE THIS YR)
AND WILL KEEP HISTORICALLY DRY CONDITIONS INTACT OVER CALIFORNIA.
WITH EVERY IMPOSING RIDGE THERE IS LIKELY AN EQUALLY IMPRESSIVE
TROUGH...AND IF YOU HAVE BEEN READING THESE DISCUSSIONS OF LATE YOU
WILL KNOW THAT THIS CASE WILL BE NO DIFFERENT. A DEEP FULL LATITUDE
TROUGH WILL BE CEMENTED IN PLACE OVER THE EASTERN HALF OF NORTH
AMERICA. WHILE THIS WILL MOST CERTAINLY PRODUCE A FEED OF VERY COLD
AIR FROM THE CANADIAN ARCTIC...GYRES IN PLACE NEAR THE CIRCLE WILL
TEMPORARILY PREVENT A CROSS POLAR FLOW FROM REINFORCING THE FRIGID
AIRMASS. 00Z ENSEMBLES SUGGEST THAT THIS COULD CHANGE DURING THE
LONG TERM PERIOD THOUGH.
SUMMING THIS UP...TEMPERATURES WILL AVERAGE BELOW NORMAL DURING THIS
PERIOD WITH A DOWNWARD TREND TOWARDS FRIGID WEATHER AS WE HEAD INTO
NEXT WEEK. IN TERMS OF THE DAY TO DAY DETAILS...
AN EXITING MID LEVEL DISTURBANCE WILL EXIT THE FINGER LAKES AND
EASTERN LAKE ONTARIO REGIONS SATURDAY MORNING...BUT NOT BEFORE
PRODUCING A FEW MORE HOURS OF LIGHT SNOW FOR SITES EAST OF THE
GENESEE RIVER. ONLY EXPECT AN ADDITIONAL INCH OR TWO OF ACCUMULATION
(ON TOP OF MINOR ACCUMS FROM THE PREVIOUS NIGHT)...OTHERWISE
FLURRIES WILL INTERMINGLE WITH BREAKS OF SUN...WITH THE GREATEST
CHANCE FOR ANY SUN COMING OVER THE FAR WESTERN COUNTIES. HIGH TEMPS
WILL BE IN THE 20S.
THE SUBTLE RIDGING WILL BRING FAIR WEATHER TO THE REGION FOR THE
FIRST HALF OF SATURDAY NIGHT...THEN A HEALTHY MID LEVEL DISTURBANCE
WILL PASS BY TO OUR SOUTH WHILE ITS ATTENDANT SFC TROUGH WILL MAKE
ITS WAY OVER LAKE ERIE. THIS COULD TOUCH OFF SOME LIGHT SNOW SHOWERS
OVER THE WESTERN COUNTIES WHILE SOME WEAK LAKE SNOWS WILL BE
POSSIBLE NORTH OF THE TUG HILL. OVERNIGHT LOWS WILL GENERALLY BE IN
THE TEENS TO NEAR 20.
ON SUNDAY...THE PASSING OF A LONGWAVE TROUGH WILL HELP TO GENERATE
SOME NUISANCE SCATTERED SNOW SHOWERS. THIS ACTIVITY SHOULD BE
ENHANCED A BIT EAST AND NORTHEAST OF BOTH LAKES WHERE A CAP OF 6K FT
AND A MINIMALLY SHEARED ENVIRONMENT WILL BE IN PLACE. SNOW ACCUMS
WILL BE UNDER AN INCH IN MOST AREAS...WITH MORE SIGNIFICANT SNOWS
POSSIBLE NEAR AND NORTH OF THE TUG HILL WHERE SUBSTANTIAL LAKE
EFFECT WILL BE LIKELY. AFTERNOON TEMPS WILL GENERALLY RANGE FROM 25
TO 30.
IT WILL BECOME WINDY SUNDAY AFTERNOON AND EVENING...AS A WELL
ALIGNED...INCREASINGLY TIGHT PRESSURE GRADIENT FROM H925 TO H7 WILL
SET UP AHEAD OF AN APPROACHING ARCTIC COLD FRONT. WINDS OF 50-55
KNOTS AT 3K FT WILL BE FOUND JUST AHEAD OF THIS FRONT. CONTINUITY OF
SFC WINDS AVERAGING 25 TO 35 KNOTS STILL LOOK REASONABLE NEAR THE
LAKES...SO THIS WILL BE CLOSE TO ADVISORY CRITERIA. WILL MENTION
THIS IN THE UPDATED HWO PRODUCT.
THE ARCTIC COLD FRONT WILL DROP ACROSS THE REGION SUNDAY NIGHT. THIS
FRONT WILL USHER IN H85 TEMPS AS LOW AS -20C (OVR LK ONT) BY
DAYBREAK MONDAY WHILE GENERATING ADDITIONAL SNOW SHOWERS.
FINALLY FOR MONDAY AND MONDAY NIGHT...A DEEP NORTHWEST FLOW WILL
ADVECT SUB -22C H85 AIR DOWN ACROSS THE LOWER GREAT LAKES AND OVER
OUR REGION. HAVE LOWERED MONDAY HIGH TEMPS AS A RESULT...WITH THE
HIGHEST TEMPS LIKELY OCCURRING EARLY THEN HOLDING STEADY OR FALLING
THROUGH THE TEENS IN THE AFTERNOON. MONDAY NIGHT...MERCURY READINGS
WILL DROP INTO THE SINGLE DIGITS FOR ALL BUT THE NORTH COUNTRY WHERE
NEGATIVE NUMBERS WILL BE POSSIBLE. THESE TEMPS WILL BE AT LEAST 15
DEG F BELOW NORMAL VALUES.
THE FRIGID NORTHWEST FLOW WILL ALSO SUPPORT SOME LAKE EFFECT SNOW
SHOWERS...ESPECIALLY SOUTHEAST OF LK ONTARIO AS THE STILL MAINLY
OPEN WATERS OF THAT LAKE WILL GENERATE A STRONGER RESPONSE.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
TEMPERATURES WILL AVERAGE WELL BELOW NORMAL THROUGH...AND LIKELY
WELL BEYOND...THIS FORECAST PERIOD AS ALL AVAILABLE ENSEMBLES ARE IN
STRONG AGREEMENT THAT AN UNUSUALLY STRONG +PNA PATTERN WILL PERSIST.
THE LAST TIME WE EXPERIENCED A +PNA OF THIS MAGNITUDE WAS THE WINTER
OF 2009-2010 WHEN TEMPERATURES EVERY WINTER MONTH AVERAGED BELOW
NORMAL. IT IS INTERESTING TO NOTE THAT SIMILAR WEST COAST TO SIBERIA
RIDGING WAS IN PLACE DURING THE INFAMOUS WINTER OF 1976-77.
THIS PATTERN WILL SUPPORT A PERSISTENT FLOW OUT OF THE CANADIAN
ARCTIC...WITH ENSEMBLES NOW SUGGESTING REINFORCING ARCTIC AIR OUT OF
SIBERIA WITHIN TIMES OF CROSS POLAR FLOW. IF THIS WERE TO VERIFY...
IT IS LIKELY THAT WE WOULD EXPERIENCE WELL BELOW NORMAL TEMPERATURES
BEYOND THIS FORECAST PERIOD...THROUGH NEXT WEEKEND.
WHILE IT WILL BE QUITE COLD DURING THIS PERIOD...THE DOMINATING
NORTHERN STREAM WILL KEEP THE NORMALLY MORE ACTIVE SUB TROPICAL JET
WELL TO OUR SOUTH...THUS SPARING US FROM ANY SIGNIFICANT PCPN
EVENTS. INSTEAD...THE FRIGID WEATHER WILL ENCOURAGE PERSISTENT LAKE
SNOWS SOUTH AND SOUTHEAST OF THE LAKES. DAILY SNOWFALL FROM THIS
ACTIVITY IS NOT EXPECTED TO BE SIGNIFICANT...ALTHOUGH TOTAL AMOUNTS
THROUGH THE PERIOD COULD ADD UP TO RESPECTABLE AMOUNTS.
ENJOY THE COLD WEATHER.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
A MIX OF VFR AND MVFR CIGS WILL CONTINUE THIS AFTERNOON ACROSS THE
REGION WITH MVFR FAVORED ACROSS HIGHER TERRAIN AND VFR AT LOWER
ELEVATIONS. SKIES ARE ALREADY CLEARING NORTHEAST OF LAKE ERIE
INCLUDING KBUF-KIAG...AND THIS CLEARING TREND MAY BRIEFLY SPREAD
ACROSS THE REST OF THE AREA DURING THE LATE AFTERNOON AND EARLY
EVENING.
A POTENT MID LEVEL DISTURBANCE AND WEAK SURFACE LOW WILL THEN
APPROACH FROM THE OHIO VALLEY LATER THIS EVENING. THIS MAY PRODUCE A
QUICK BURST OF MODERATE SNOW ACROSS WESTERN NY FOR AN HOUR OR TWO
WITH VSBY APPROACHING AIRFIELD MINIMUMS BRIEFLY. AFTER THIS INITIAL
BURST OF SNOW...THERE MAY BE A BREAK FOLLOWED BY MORE SNOW LATER
TONIGHT INTO SATURDAY. THE SECOND BATCH OF SNOW SHOULD FOCUS MOST OF
ITS MODERATE SNOW ON THE FINGER LAKES AND CENTRAL NY...WITH LIGHTER
SNOW EXTENDING BACK INTO WESTERN NY AND THE NORTH COUNTRY. EXPECT
PERIODS OF IFR VSBY WITH THIS AS WELL. THE SNOW WILL SLOWLY TAPER
OFF TO FLURRIES FROM WEST TO EAST SATURDAY AFTERNOON WITH IMPROVING
VSBY.
CIGS WILL DROP DOWN TO MVFR WITHIN THE HEAVIER SNOW SHOWERS THIS
EVENING...THEN EXPECT A TREND OF MORE WIDESPREAD MVFR CIGS WITH IFR
ACROSS HIGHER TERRAIN LATE TONIGHT THROUGH SATURDAY AS LOW LEVEL
MOISTURE DEEPENS...AND UPSLOPE FLOW INCREASES.
OUTLOOK...
SUNDAY THROUGH WEDNESDAY...VFR...WITH OCCASIONAL RESTRICTIONS TO
MVFR/IFR IN SCATTERED TO NUMEROUS SNOW SHOWERS.
&&
.MARINE...
FOLLOWING THE PASSAGE OF A WARM FRONT THIS MORNING...MODEST
SOUTHERLY WINDS WILL VEER SOUTHWESTERLY AND INCREASE SOME TODAY...
WITH THESE BRIEFLY REACHING LOW-END ADVISORY LEVELS ON LAKE
ERIE...THE UPPER NIAGARA RIVER...AND WESTERN PORTIONS OF LAKE
ONTARIO...THEN DIMINISHING AGAIN LATER ON THIS AFTERNOON AND THIS
EVENING. FOR THESE...SMALL CRAFT ADVISORIES REMAIN IN EFFECT AS
OUTLINED BELOW.
AFTER THIS...RELATIVELY QUIET CONDITIONS ARE THEN EXPECTED FOR
TONIGHT...BEFORE A COUPLE OF PASSING CLIPPER SYSTEMS BRING
ADDITIONAL ROUNDS OF ADVISORY-LEVEL SOUTHWESTERLIES DURING THE
COURSE OF THE WEEKEND...WITH THE STRONGEST OF THESE LOOKING TO
COME ON SUNDAY.
&&
.CLIMATE...
THE COLD THAT DEVELOPS NEXT WEEK IS VERY LIKELY TO LAST THROUGH THE
END OF JANUARY AND POSSIBLY INTO EARLY FEBRUARY WITH MOST DAYS
SEEING BELOW AVERAGE OR EVEN WELL BELOW AVERAGE TEMPERATURES.
THE D+11 TOOLS FROM CPC WHICH TAKE A 7 DAY RUNNING MEAN OF THE GEFS
ENSEMBLE MEAN FROM JANUARY 24-30 SHOW A VERY DEEP LONGWAVE TROUGH
OVER EASTERN NORTH AMERICA WITH A SHARP RIDGE ALONG THE WEST COAST
EXTENDING ALL THE WAY NORTH TO ALASKA AND BEYOND TO THE NORTH POLE.
TO SEE SUCH AMPLIFICATION IN A ONE WEEK AVERAGE OF GEFS MEAN 500MB
HEIGHT IS VERY IMPRESSIVE...SINCE IT IS A TIME AVERAGED PRODUCT OF
SOMETHING THAT IS ALREADY AN AVERAGE OF THE VARIOUS ENSEMBLE
MEMBERS. BOTTOM LINE...THIS SHOWS VERY GOOD AGREEMENT AMONGST GEFS
ENSEMBLE MEMBERS FOR A LONG PERIOD OF HIGHLY AMPLIFIED LONGWAVE
FLOW. THE ECMWF ENSEMBLE MEAN ALSO SHOWS A SIMILAR PATTERN.
THE PATTERN SHOWN BY THE ENSEMBLE MEAN IS A STRONG POSITIVE PNA
PATTERN...WELL KNOWN FOR DELIVERING ANY COLD AIR AVAILABLE INTO OUR
PORTION OF NORTH AMERICA. THIS LONGWAVE PATTERN ALSO SUPPORTS THE
POTENTIAL FOR CROSS POLAR FLOW...ALLOWING SIBERIAN AIR TO CROSS THE
POLES AND SPILL INTO NORTHERN CANADA. FROM THERE...THE PATTERN
SUPPORTS PIECES OF THIS COLD MOVING INTO THE NORTHERN TIER OF THE
UNITED STATES FROM THE UPPER MISSISSIPPI VALLEY EAST ACROSS THE
GREAT LAKES AND NEW ENGLAND.
THE D+11 TOOLS ALSO LOOK BACK TO FIND ANALOGS THAT CLOSELY MATCH
THIS 500MB PATTERN TO PAST EVENTS...GIVING THE 10 BEST MATCHES FOR
ANALOG DATES. A LOOK BACK AT SURFACE CONDITIONS DURING THESE ANALOG
DATES SHOW THE VAST MAJORITY OF THEM HAD SURFACE TEMPERATURES OF
15-20 DEGREES BELOW AVERAGE.
TO SUM UP...THE PATTERN STRONGLY SUPPORTS MUCH BELOW AVERAGE
TEMPERATURES MOST OF THE TIME FROM NEXT WEEK THROUGH THE END OF THE
MONTH AND POSSIBLY INTO EARLY FEBRUARY. OF COURSE WITH COLD AIR
COMES LAKE EFFECT POTENTIAL...BUT THE DETAILS WHICH DRIVE LOCATION
AND AMOUNTS ARE NOT APPARENT AT THIS TIME RANGE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LEZ020-
040-041.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
LOZ042.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...HITCHCOCK
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...HITCHCOCK
MARINE...JJR
CLIMATE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS PORTLAND OR
1015 AM PST FRI JAN 17 2014
.SYNOPSIS...A STRONG RIDGE OF HIGH PRESSURE WILL REMAIN OVER THE
REGION TODAY. A WEAK TROUGH ALOFT WILL MOVE ACROSS THE RIDGE THIS
WEEKEND...DROPPING A WEAK FRONT DOWN INTO THE NW CORNER OF OREGON
SATURDAY AND SUNDAY. THE RIDGE OF HIGH PRESSURE ALOFT WILL REBUILD
EARLY NEXT WEEK.
&&
.MORNING UPDATE...ONLY A FEW MINOR CHANGES NEEDED THIS MORNING.
OBSERVATIONS INDICATE THAT VISIBILITIES REMAIN AT OR BELOW ONE HALF
MILE ACROSS THE VALLEYS THIS MORNING. THEREFORE EXTENDED THE DENSE
FOG ADVISORY THROUGH NOON TODAY AND ADJUSTED GRIDS TO INCREASE CLOUD
COVER ACROSS THE NORTHERN WILLAMETTE VALLEY FOR THE NEXT SEVERAL
HOURS. THE REMAINDER OF THE FORECAST REMAINS VALID AND EXPECT TODAY
TO BE SIMILAR TO YESTERDAY...WITH COOL TEMPERATURES WITH FOG AND
CLOUDS IN THE INTERIOR VALLEYS...AND CLEAR SKIES WITH WARMER
TEMPERATURES AT THE COAST AND HIGHER ELEVATIONS.
ALSO ISSUED AN AIR STAGNATION ADVISORY FOR THE CLARK COUNTY AND LOWER
COLUMBIA AND I-5 CORRIDOR ZONES IN SOUTHWEST WASHINGTON. THIS AND THE
EXISTING AIR STAGNATION ADVISORY FOR THE CENTRAL AND SOUTHERN
WILLAMETTE VALLEY WILL BE IN EFFECT THROUGH NEXT FRIDAY MORNING.
OPTED NOT TO INCLUDE METRO PORTLAND AREA AT THIS TIME BECAUSE EAST
WINDS THROUGH THE GORGE WILL LIKELY BE SUFFICENT TO PROVIDE MIXING TO
PREVENT STAGNANT AIR THROUGH THE NEXT FEW DAYS. CULLEN
.LONG TERM...MONDAY THROUGH THROUGH THURSDAY. FEW CHANGES IN THE
EXTENDED PERIOD. AFTER THE WEAK FRONT PASSES THROUGH THE AREA ON
SUNDAY...HIGH PRESSURE WILL QUICKLY REBUILD OVER THE EASTERN PACIFIC
AND PACIFIC NORTHWEST. THIS RIDGE WILL CONTINUE TO DOMINATE OUR
WEATHER PATTERN AND BY TUESDAY THE UPPER RIDGE WILL AMPLIFY WITH THE
RIDGE AXIS LOCATED ALONG OR NEAR THE WEST COAST. BOTH THE 12Z ECMWF
AND GFS DEPICT A SHORTWAVE IMPULSE THAT SPLITS NEAR 140W EARLY NEXT
WEEK...WITH A CLOSED LOW MOVING INTO THE CENTRAL CA COAST AND AN
UPPER LEVEL TROUGH WELL TO OUR NORTH OVER THE TOP OF THE RIDGE. UNTIL
THE FORECAST MODELS GIVE A STRONG REASON TO BELIEVE OTHERWISE...IT
APPEARS THIS RIDGE WILL CONTINUE REMAIN IN PLACE AND KEEP THE
FORECAST AREA DRY THROUGH AT LEAST LATE NEXT WEEK.
A RETURN OF DAILY FOG AND LOW CLOUDS IS LIKELY FOR THE VALLEY
LOCATIONS...THOUGH THE NORTH WILLAMETTE VALLEY MAY BE MORE LIKELY TO
SEE LESS FOG AND/OR BREAK OUT EARLIER DURING THE MIDDLE OF NEXT WEEK
DEPENDING ON EAST WINDS DEVELOPING THROUGH THE COLUMBIA RIVER GORGE.
HIGH TEMPERATURES LOOK TO BE A FEW DEGREES ABOVE SEASONAL NORMALS
THROUGH THE EXTENDED WHILE LOWS WILL BE NEAR NORMS. CULLEN
&&
.AVIATION...VFR ACROSS REGION...EXCEPT IN THE LOWER
COLUMBIA/COWLITZ AND WILLAMETTE VALLEY WHERE IFR FOG/STRATUS
PERSISTS. ALREADY SEEING TOPS OF THE CLOUDS IN THE WEST HILLS OF
PORTLAND SO TOPS AROUND 1000 FT. EXPECT A SIMILAR SITUATION TO
THURSDAY WITH SOME IMPROVEMENT LATE THIS MORNING AND EARLY
AFTERNOON...AND THEN AREAS OF CLEARING IN THE AFTERNOON. THEN A
RETURN TO LIFR CONDITIONS THIS EVENING AND OVERNIGHT. EAST WINDS
WILL PROVIDE SOME CLEARING AROUND KPDX AND KTTD THIS
AFTERNOON BUT WILL BE MAINLY ABOVE THE FOG LAYER. HRRR SUGGESTS
EAST WINDS PUNCH THROUGH TO THE SURFACE AT KTTD AFTER 0Z
TODAY...SO KEPT THE LIGHT WNW WIND IN PLACE FOR THE NORTH VALLEY
SITES FOR THE DAY. EAST WINDS MAY SNEAK OVER TO KHIO LATER TODAY.
WITH A STRONGER GRADIENT EXPECT THE NEAR GORGE CLEAR OUT A BIT FOR A
BIT LONGER THURSDAY.
KPDX AND APPROACHES...EXPECT DENSE FOG AND LOW CLOUDS THROUGH THE
MORNING AS MOST OF THE EAST FLOW IS JUST ABOVE THE FOG LAYER.
STILL EXPECT TO SEE SOME EAST WIND FILTERING INTO KPDX OPS AREA
AT TIMES AFTER 21Z. SHOULD SEE A REPEAT OF THU...BUT HOPEFULLY A BIT
MORE CLEARING ON EASTERN APPROACHES. THOUGH STRATUS LIKELY TO
PERSIST OVER CLARK COUNTY AND FROM WILSONVILLE SOUTHWARD. KMD
&&
.MARINE...LITTLE CHANGE. HIGH PRES REMAINS OVER PAC NW...WITH
OFFSHORE WINDS 10 TO 15 KT. WINDS EASE BACK SAT AND SUN. SEAS
HOLDING AT 4 TO 5 FT TODAY. SWELL WILL INCREASE THIS WEEKEND...
WITH 10 TO 11 FT AGAIN LATER SAT NIGHT AND SUN. EXPECT SIMILAR
CONDITIONS NEXT WEEK WITH OCCASIONAL WEAK FRONTS PASSING THROUGH
THAT WILL BUMP SWELLS UP ABOVE 10 FT AT TIMES...NOTABLY LATER
MONDAY AND AGAIN LATER THURSDAY. KMD
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...AIR STAGNATION ADVISORY FROM 7 PM THIS EVENING TO 10 AM PST
FRIDAY FOR LOWER COLUMBIA.
AIR STAGNATION ADVISORY UNTIL 10 AM PST FRIDAY FOR CENTRAL
WILLAMETTE VALLEY-SOUTH WILLAMETTE VALLEY.
DENSE FOG ADVISORY UNTIL NOON PST TODAY FOR CENTRAL WILLAMETTE
VALLEY-GREATER PORTLAND METRO AREA-SOUTH WILLAMETTE VALLEY.
WA...AIR STAGNATION ADVISORY FROM 7 PM THIS EVENING TO 10 AM PST
FRIDAY FOR GREATER VANCOUVER AREA-I-5 CORRIDOR IN COWLITZ
COUNTY.
DENSE FOG ADVISORY UNTIL NOON PST TODAY FOR GREATER VANCOUVER
AREA.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
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 HOUSTON/GALVESTON TX
1137 AM CST FRI JAN 17 2014
.DISCUSSION...
18Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
DRY AND COOL AIR MASS MAINTAINING REGIONAL VFR CONDITIONS THROUGH
THE PERIOD. SKY CLEAR WITH A MODEST NORTH-NORTHEAST BREEZE TODAY
BECOMING VRB03KTS/CALM OVERNIGHT...WAKE UP FROM SOUTHEAST-SOUTH
BY LATE SATURDAY MORNING. 31
&&
.PREV DISCUSSION... /ISSUED 1031 AM CST FRI JAN 17 2014/
UPDATE...
SEE MORNING UPDATE AND FIRE WEATHER DISCUSSION.
DISCUSSION...
12Z SOUNDINGS SUPPORT TEMPS IN THE MID AND UPPER 60S BUT WEAK COLD
AIR ADVECTION IN THE WAKE OF AN EARLY MORNING COLD FRONT WILL
SHAVE A FEW DEGREES FROM SOUNDINGS VALUES. SURFACE DEW POINTS ARE
CONSIDERABLY DRIER THAN MODELS SUGGEST SO HAVE EDITED THE DEW PT
GRIDS TO REFLECT CURRENT LOWER VALUES. THIS WILL HAVE
IMPLICATIONS FOR FIRE WEATHER AND SEE THE FIRE WEATHER DISCUSSION
FOR MORE INFO. MADE SOME MINOR TWEAKS HERE AND THERE BUT THE
REASONING FROM THE PREVIOUS FCST IS STILL ON TARGET. 43
FIRE WEATHER...
SURFACE DEW PTS ARE IN THE TEENS AND COULD DROP FURTHER WITH
MIXING THIS AFTERNOON. RUC13 DATA SUGGEST DEW PTS IN THE SINGLE
DIGITS THIS AFTN. RH VALUES WILL STRUGGLE TO REACH 25 PERCENT
TODAY WHICH IS CRITICALLY DRY. KHGX VWP SHOWS WINDS OF 20 TO 20
KNOTS IN THE 1000-3000 FOOT LAYER. FEEL SOME OF THIS WIND ENERGY
WILL MIX TO THE SURFACE THIS AFTN SO BUMPED WINDS UP A LITTLE.
WIND SPEEDS WILL REMAIN BELOW RED FLAG CRITERIA BUT CONSIDERING
THE DRY ANTECEDENT CONDITIONS...VERY LOW RH VALUES AND MODERATE
WINDS...FEEL THERE IS STILL AN ELEVATED THREAT FOR DANGEROUS FIRE
WEATHER CONDS. 43
PREV DISCUSSION... /ISSUED 456 AM CST FRI JAN 17 2014/
DISCUSSION...
SEE AVIATION FOR 12Z TAF ISSUANCE.
AVIATION...
CURRENT TAF PACKAGE LOOKS ON TRACK AND HAVE MADE ONLY MINOR
CHANGES. FRONT HAS CONTINUED TO MOVE OFFSHORE WITH SECONDARY COLD
FRONT MOVING SOUTH FROM NORTH TEXAS. NORTH WINDS AND VFR CONDITIONS
ARE EXPECTED THIS AFTERNOON. WINDS WILL THEN RELAX THIS EVENING AS
SURFACE HIGH PRESSURE SHIFTS OVERHEAD. 23
PREV DISCUSSION... /ISSUED 444 AM CST FRI JAN 17 2014/
DISCUSSION...
DRY AIR IS SLOWLY SPREADING OVER THE AREA IN THE WAKE OF A WEAK
PACIFIC COLD FRONTAL BOUNDARY. RAINS OVER THE GULF WATERS SHOULD
SHIFT SOUTHWARD AS FRONT MOVES OFF THE COAST AND ACROSS THE GULF
WATERS EARLY THIS MORNING. SKIES WILL START OFF WITH SOME HIGH
CLOUDS BUT AS THE UPPER TROUGH ROTATES AWAY TO THE EAST EXPECTING
MORE SUBSIDENCE AND THE HIGH CLOUDS TO DISSIPATE AND DEPART THIS
AFTERNOON. AFTER HIGHS SHOULD ONLY REACH THE LOWER 60S TODAY AFTER
YESTERDAYS WARM UPPER 60S TO AROUND 70. SFC RIDGE AXIS WILL BE
OVERHEAD SATURDAY MORNING AND TEMPERATURES WILL DROP TO 29-31
DEGREES OVER THE NORTHEASTERN AREAS BUT IT LOOKS LIKE THE METRO
AREA AND AROUND CLL SHOULD STAY ABOVE FREEZING. THE RIDGE MOVES
OFF QUICKLY TO THE EAST SATURDAY AND MOISTURE AND WARMTH MAKES A
COMEBACK. WARM FRONT SHOULD REACH UP INTO THE COASTAL WATERS AND
MAY JUST REACH THE COAST SATURDAY NIGHT SO WITH THE UPPER JET
TRAVERSING THE STATE AND SOME WEAK LIFT MAY HAVE ISO-SCT SHOWERS
OVER THE GULF WATERS BUT SETX SHOULD STAY DRY. REINFORCING PACIFIC
COLD FRONT CROSSES SETX SATURDAY NIGHT WASHING OUT VERY QUICKLY
AND SE-S WIND RESUME SUNDAY AFTERNOON/NIGHT. WARMER WEATHER
RETURNS MONDAY BEFORE THE FRONT SWINGS DOWN MONDAY NIGHT. FOR NOW
WILL ONLY SHOW SOME POPS IN THE SOUTHWEST AREAS FOR EARLY TUESDAY
MORNING AS MOISTURE RETURN DOESN`T PEAK UNTIL EARLY TUESDAY. SOME
POSSIBILITY OF SEA FOG BUT MAYBE MORE OF THE 2-5 MILE VARIETY WITH
THE SOUTHWEST TRAJECTORIES. STRONGER HIGH PRESSURE DROPPING SOUTH
TUESDAY PUSHES THE FRONT THROUGH AND SHOULD MAKE FOR A COOL PERIOD
FROM TUE-THU (WARMING UP THU). UPPER PATTERN BRINGS A DECENT S/W
OUT OF THE PACIFIC ON SUBTROPICAL JET AND MAY LEAD TO BETTER RAIN
CHANCES BY FRIDAY/SATURDAY.
45
MARINE...
WIDESPREAD CONVECTION IS ONGOING THIS MORNING OVER THE
OFFSHORE WATERS. THE DIFFUSE FRONTAL BOUNDARY WILL CONTINUE TO PUSH
OFFSHORE THIS MORNING WHICH SHOULD HELP BRING THE PRECIPITATION TO
AN END. BEHIND THE FRONT WINDS WILL REACH SCEC CRITERIA OVER THE
OFFSHORE WATERS WITH SLIGHTLY WEAKER WINDS OVER THE COOLER SHELF
WATERS. WINDS WILL FALL BELOW SCEC CRITERIA BY THIS EVENING. SURFACE
HIGH PRESSURE BEHIND THE FRONT WILL QUICKLY MOVE OFF TO THE EAST
FRIDAY NIGHT INTO SATURDAY MORNING ALLOWING ONSHORE FLOW TO RESUME.
LIGHT TO MODERATE ONSHORE WINDS WITH 2 TO 4 FT SEAS WILL PERSIST
UNTIL TUESDAY WHEN THE NEXT COLD FRONT IS FORECASTED TO MOVE OVER
THE WATERS. ADVISORIES WILL LIKELY BE NEEDED AFTER THE FRONTAL
PASSAGE. 23
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 35 66 45 70 52 / 0 10 10 10 10
HOUSTON (IAH) 37 65 46 72 52 / 0 0 10 10 10
GALVESTON (GLS) 47 63 54 67 56 / 0 0 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL NOON CST TODAY FOR THE
FOLLOWING ZONES: MATAGORDA BAY...WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO
60 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 5 PM CST THIS
AFTERNOON FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
HIGH ISLAND TO FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...43
AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1031 AM CST FRI JAN 17 2014
.UPDATE...
SEE MORNING UPDATE AND FIRE WEATHER DISCUSSION.
&&
.DISCUSSION...
12Z SOUNDINGS SUPPORT TEMPS IN THE MID AND UPPER 60S BUT WEAK COLD
AIR ADVECTION IN THE WAKE OF AN EARLY MORNING COLD FRONT WILL
SHAVE A FEW DEGREES FROM SOUNDINGS VALUES. SURFACE DEW POINTS ARE
CONSIDERABLY DRIER THAN MODELS SUGGEST SO HAVE EDITED THE DEW PT
GRIDS TO REFLECT CURRENT LOWER VALUES. THIS WILL HAVE
IMPLICATIONS FOR FIRE WEATHER AND SEE THE FIRE WEATHER DISCUSSION
FOR MORE INFO. MADE SOME MINOR TWEAKS HERE AND THERE BUT THE
REASONING FROM THE PREVIOUS FCST IS STILL ON TARGET. 43
&&
.FIRE WEATHER...
SURFACE DEW PTS ARE IN THE TEENS AND COULD DROP FURTHER WITH
MIXING THIS AFTERNOON. RUC13 DATA SUGGEST DEW PTS IN THE SINGLE
DIGITS THIS AFTN. RH VALUES WILL STRUGGLE TO REACH 25 PERCENT
TODAY WHICH IS CRITICALLY DRY. KHGX VWP SHOWS WINDS OF 20 TO 20
KNOTS IN THE 1000-3000 FOOT LAYER. FEEL SOME OF THIS WIND ENERGY
WILL MIX TO THE SURFACE THIS AFTN SO BUMPED WINDS UP A LITTLE.
WIND SPEEDS WILL REMAIN BELOW RED FLAG CRITERIA BUT CONSIDERING
THE DRY ANTECEDENT CONDITIONS...VERY LOW RH VALUES AND MODERATE
WINDS...FEEL THERE IS STILL AN ELEVATED THREAT FOR DANGEROUS FIRE
WEATHER CONDS. 43
&&
.PREV DISCUSSION... /ISSUED 456 AM CST FRI JAN 17 2014/
DISCUSSION...
SEE AVIATION FOR 12Z TAF ISSUANCE.
AVIATION...
CURRENT TAF PACKAGE LOOKS ON TRACK AND HAVE MADE ONLY MINOR
CHANGES. FRONT HAS CONTINUED TO MOVE OFFSHORE WITH SECONDARY COLD
FRONT MOVING SOUTH FROM NORTH TEXAS. NORTH WINDS AND VFR CONDITIONS
ARE EXPECTED THIS AFTERNOON. WINDS WILL THEN RELAX THIS EVENING AS
SURFACE HIGH PRESSURE SHIFTS OVERHEAD. 23
PREV DISCUSSION... /ISSUED 444 AM CST FRI JAN 17 2014/
DISCUSSION...
DRY AIR IS SLOWLY SPREADING OVER THE AREA IN THE WAKE OF A WEAK
PACIFIC COLD FRONTAL BOUNDARY. RAINS OVER THE GULF WATERS SHOULD
SHIFT SOUTHWARD AS FRONT MOVES OFF THE COAST AND ACROSS THE GULF
WATERS EARLY THIS MORNING. SKIES WILL START OFF WITH SOME HIGH
CLOUDS BUT AS THE UPPER TROUGH ROTATES AWAY TO THE EAST EXPECTING
MORE SUBSIDENCE AND THE HIGH CLOUDS TO DISSIPATE AND DEPART THIS
AFTERNOON. AFTER HIGHS SHOULD ONLY REACH THE LOWER 60S TODAY AFTER
YESTERDAYS WARM UPPER 60S TO AROUND 70. SFC RIDGE AXIS WILL BE
OVERHEAD SATURDAY MORNING AND TEMPERATURES WILL DROP TO 29-31
DEGREES OVER THE NORTHEASTERN AREAS BUT IT LOOKS LIKE THE METRO
AREA AND AROUND CLL SHOULD STAY ABOVE FREEZING. THE RIDGE MOVES
OFF QUICKLY TO THE EAST SATURDAY AND MOISTURE AND WARMTH MAKES A
COMEBACK. WARM FRONT SHOULD REACH UP INTO THE COASTAL WATERS AND
MAY JUST REACH THE COAST SATURDAY NIGHT SO WITH THE UPPER JET
TRAVERSING THE STATE AND SOME WEAK LIFT MAY HAVE ISO-SCT SHOWERS
OVER THE GULF WATERS BUT SETX SHOULD STAY DRY. REINFORCING PACIFIC
COLD FRONT CROSSES SETX SATURDAY NIGHT WASHING OUT VERY QUICKLY
AND SE-S WIND RESUME SUNDAY AFTERNOON/NIGHT. WARMER WEATHER
RETURNS MONDAY BEFORE THE FRONT SWINGS DOWN MONDAY NIGHT. FOR NOW
WILL ONLY SHOW SOME POPS IN THE SOUTHWEST AREAS FOR EARLY TUESDAY
MORNING AS MOISTURE RETURN DOESN`T PEAK UNTIL EARLY TUESDAY. SOME
POSSIBILITY OF SEA FOG BUT MAYBE MORE OF THE 2-5 MILE VARIETY WITH
THE SOUTHWEST TRAJECTORIES. STRONGER HIGH PRESSURE DROPPING SOUTH
TUESDAY PUSHES THE FRONT THROUGH AND SHOULD MAKE FOR A COOL PERIOD
FROM TUE-THU (WARMING UP THU). UPPER PATTERN BRINGS A DECENT S/W
OUT OF THE PACIFIC ON SUBTROPICAL JET AND MAY LEAD TO BETTER RAIN
CHANCES BY FRIDAY/SATURDAY.
45
MARINE...
WIDESPREAD CONVECTION IS ONGOING THIS MORNING OVER THE
OFFSHORE WATERS. THE DIFFUSE FRONTAL BOUNDARY WILL CONTINUE TO PUSH
OFFSHORE THIS MORNING WHICH SHOULD HELP BRING THE PRECIPITATION TO
AN END. BEHIND THE FRONT WINDS WILL REACH SCEC CRITERIA OVER THE
OFFSHORE WATERS WITH SLIGHTLY WEAKER WINDS OVER THE COOLER SHELF
WATERS. WINDS WILL FALL BELOW SCEC CRITERIA BY THIS EVENING. SURFACE
HIGH PRESSURE BEHIND THE FRONT WILL QUICKLY MOVE OFF TO THE EAST
FRIDAY NIGHT INTO SATURDAY MORNING ALLOWING ONSHORE FLOW TO RESUME.
LIGHT TO MODERATE ONSHORE WINDS WITH 2 TO 4 FT SEAS WILL PERSIST
UNTIL TUESDAY WHEN THE NEXT COLD FRONT IS FORECASTED TO MOVE OVER
THE WATERS. ADVISORIES WILL LIKELY BE NEEDED AFTER THE FRONTAL
PASSAGE. 23
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 60 35 66 45 70 / 0 0 10 10 10
HOUSTON (IAH) 63 37 65 46 72 / 0 0 0 10 10
GALVESTON (GLS) 62 47 63 54 67 / 0 0 0 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL NOON CST TODAY FOR THE
FOLLOWING ZONES: MATAGORDA BAY...WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO
60 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 5 PM CST THIS
AFTERNOON FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
HIGH ISLAND TO FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...43
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1108 AM CST FRI JAN 17 2014
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND SATURDAY
ISSUED AT 417 AM CST FRI JAN 17 2014
SURFACE AND UPPER SYSTEM PULLING OUT OF AREA EARLY
THIS MORNING. DRIER AIR WORKING INTO WESTERN HALF OF STATE WITH
CEILINGS IMPROVING...SNOW ENDING. LIGHT SNOW CONTINUES OVER MUCH
OF CWA ATTM WITH PERSISTENT BANDING FEATURE NOW LOCATED FROM GRB
INTO ISW. THOUGH RADAR RETURNS LOOK MORE OMINOUS...SURFACE REPORTS
HAVE VISBYS MAINLY 2 MILES OR ABOVE. PREVIOUS FORECAST OF INCH
OVERNIGHT LOOKS TO BE HOLDING OUTSIDE OF LES REGION. MODELS SHOW
THIS TREND CONTINUING WITH BAND TAKING ON A NE TO SW ORIENTATION
AND EXITING REGION THIS AFTERNOON. GIVEN CURRENT TRENDS...LESS
THAN AN INCH OF FURTHER ACCUMULATION EXPECTED. QUESTION FOR THE DAY
IS TEMPERATURES...WITH CURRENT WARMING TREND OVER THE NORTHERN CWA
AS TEMPERATURES ARE CURRENTLY IN THE UPPER TEENS TO LOW 20S. HAVE
TRENDED HIGH TEMPS TOWARDS RAP MODEL BRINGING TODAYS MAX TEMPS UP...WITH
SOME LIKELY BEING REACHED EARLY THIS MORNING.
SURFACE RIDGE MOVES OVER STATE TONIGHT. CLEARING AND LIGHT
WINDS...WILL ALLOW TEMPS TO DROP SIGNIFICANTLY BEFORE MORE CLOUDS
MOVE IN AND WAA BEGINS DURING THE SECOND HALF OF NIGHT. TONIGHTS TEMPS
WILL LIKELY NEED ANOTHER LOOK AS MODEL TRENDS THIS RUN HAVE BEEN
TO PUSH NEXT CLIPPER SYSTEM TRACK FURTHER WEST. MAIN CHANGE THIS
FORECAST WAS TO SLOW TIMING OF PCPN INTO CENTRAL WI AND CUT BACK
ON HOW FAR NORTH AND EAST IT WILL REACH ON SAT.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY
ISSUED AT 417 AM CST FRI JAN 17 2014
UPPER LEVEL FLOW WAS FORECAST TO BE FROM THE NORTH-NORTHWEST DURING
THIS PART OF THE FORECAST...WITH A WEST COAST RIDGE AND A TROUGH
AXIS OVER...OR A LITTLE BIT TO THE EAST OF...WISCONSIN. TIMING OF
CLIPPER SYSTEMS IN THIS FLOW REGIME WILL BE A CHALLENGE FOR THIS
WEEKEND AND THE UPCOMING WEEK.
THERE IS SOME LAKE EFFECT SNOW SHOWER POTENTIAL IN NORTH CENTRAL
WISCONSIN AS COLD AIR PASSES OVER LAKE SUPERIOR...BUT GLERL ICE
CONCENTRATION GRAPHICS SHOWED LITTLE OPEN WATER NORTH AND WEST OF
THE KEWEENAW PENINSULA. HAVE KEPT POPS ON THE LOW SIDE IN NORTH
CENTRAL WISCONSIN BECAUSE OF THIS. MUCH OF NORTHERN LAKE MICHIGAN
REMAINS OPEN SO THERE IS SOME CHANCE FOR LAKE EFFECT SNOW SHOWERS
IN EASTERN WISCONSIN IF WINDS BECOME FAVORABLE IN THAT AREA...BUT
THERE DOES NOT APPEAR TO BE ANYTHING WORTH MORE THAN A LOW END
CHANCE POP AT TIMES.
HAVE A CHANCE FOR SNOW IN THE NORTH ON SATURDAY NIGHT...ASSOCIATED
WITH A DEPARTING CLIPPER. THERE WERE STILL ENOUGH DIFFERENCES
AMONG THE MODELS IN THEIR LOCATION AND TIMING OF QPF MONDAY...SO
LEFT POPS MAINLY IN THE SLIGHT CHANCE CATEGORY. OTHER THAN THESE
SYSTEMS...SLIGHT CHANCE OR LOW END CHANCE POPS DUE TO POSSIBLE
LAKE EFFECT SNOW SHOWERS.
TEMPERATURES SHOULD BE ABOVE NORMAL ON SUNDAY BEFORE THE ARCTIC
FRONT PASSES THROUGH THE AREA. AFTER THAT...EXPECT MUCH COLDER
THAN NORMAL TEMPERATURES. HIGHS ON TUESDAY AND WEDNESDAY WILL BE
CLOSER TO NORMAL LOWS FOR THIS TIME OF YEAR.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1107 AM CST FRI JAN 17 2014
SYSTEM THAT MOVED INTO THE AREA YDA HAS BEEN SLOW TO CLEAR...SO WL
NEED TO KEEP LOWER CLDS AND LGT SNOW LONGER THAN IN PREV TAFS.
SYSTEM THAT APPEARED TO BE HEADING FOR THE AREA TOMORROW NOW LOOKS
LIKE IT WL TRACK FARTHER SW.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....TE
LONG TERM......MG
AVIATION.......SKOWRONSKI