Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/30/13
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
641 AM PST SAT DEC 28 2013
.UPDATE...
QUICK UPDATE THIS MORNING TO INCREASE THE COVERAGE OF FREEZING FOG
IN WESTERN NEVADA, BASED OFF OF LATEST IR IMAGERY. LOOKS LIKE A
GOOD AMOUNT OF FOG HAS CREPT DOWN INTO THE SPANISH SPRINGS VALLEY
NORTH OF SPARKS, AS WELL AS INTO THE MASON VALLEY AND AS FAR SOUTH
AS HAWTHORNE AND WALKER LAKE. THE AREAS OF HIGHEST CONCERN REMAIN
PERSHING, CHURCHILL, AND EASTERN LASSEN COUNTIES WHERE THE
FREEZING FOG HAS REMAINED THROUGHOUT THE NIGHT AND IS MOST LIKELY
TO HAVE DEPOSITED THE MOST RIME ICE ONTO THOSE AREA ROADS. THAT
BEING SAID, ANY DRIVERS ENCOUNTERING DENSE FREEZING FOG THIS
MORNING SHOULD BE AWARE OF POTENTIAL ICY ROAD CONDITIONS.
THE LATEST HRRR MODEL IS SHOWING FOG OVER THE CARSON AND HUMBOLDT
SINKS ALL DAY LONG TODAY, SO THE DAY SHIFT WILL NEED TO MONITOR
TRENDS AND MAY NEED TO EXTEND THE ADVISORY FOR FREEZING FOG IN
FALLON AND LOVELOCK PAST 10 AM. HOON
&&
.PREVIOUS DISCUSSION... /ISSUED 240 AM PST SAT DEC 28 2013/
SYNOPSIS...
AREAS OF FOG AND LOW CLOUDS WILL PERSIST THIS MORNING IN SOME LOWER
ELEVATION VALLEYS. OTHERWISE...WEAK LOW PRESSURE WILL JUST BRING
HIGH CLOUDS THROUGH SATURDAY. WINDS MAY KICK UP ENOUGH TO MIX OUT
SOME VALLEY INVERSIONS TODAY, AND GUSTY NORTHEAST WINDS ARE LIKELY
IN THE SIERRA SATURDAY NIGHT. HIGH PRESSURE WILL BUILD BACK INTO THE
REGION NEXT WEEK WITH NO BIG STORMS ON THE HORIZON.
SHORT TERM...
THE EVER PERSISTENT FREEZING FOG THAT REFUSED TO DISSIPATE
YESTERDAY WILL FINALLY BREAK LATE THIS MORNING BY EARLY AFTERNOON
AS A WEAK AND DRY FRONTAL BOUNDARY MOVES THROUGH THE NEVADA
INTERIOR. WHILE THIS IS A COLD FRONT, TEMPERATURES WILL ACTUALLY
WARM FOR VALLEYS THAT HAVE BEEN PERSISTENTLY FOGGED IN. WINDS
SHOULD SHIFT OUT OF THE NORTH AROUND NOON TODAY WITH ONLY LIGHT
GUSTS FOR THE VALLEY SURFACES. HOPEFULLY, THE WINDS WILL BE
SUFFICIENT TO CLEAR MOST OF THE POLLUTION THAT HAS SETTLED IN
WESTERN NEVADA VALLEYS. THE THERMAL GRADIENT IS NOT THAT STRONG
SUGGESTING THAT THE VALLEYS MAY NOT BE COMPLETELY SCOURED OUT.
HOWEVER, WILL REMAIN OPTIMISTIC THAT OVERALL AIR QUALITY WILL
IMPROVE.
RIDGE WINDS WILL BECOME GUSTY UP TO ABOUT 50 MPH BY THIS
AFTERNOON AS THE WINDS BECOME MORE NORTHEASTERLY TO EASTERLY BY
EARLY SUNDAY MORNING. OTHERWISE, THE ONLY NOTABLE FORECAST ELEMENT
WILL BE AN INCREASE IN CLOUD COVER ACCOMPANYING THE FRONT THEN
LINGERING THROUGH MONDAY. BOYD
LONG TERM...TUESDAY THROUGH FRIDAY...
RIDGE OF HIGH PRESSURE REMAINS ALONG THE WEST COAST THROUGH NEXT
WEEK WITH GENERALLY LIGHT WINDS. MODELS ARE SHOWING SOME INCREASING
MOISTURE ON TUESDAY, ASSOCIATED WITH SOME WARM AIR ADVECTION ALOFT.
THIS COULD POTENTIALLY BRING SOME LIGHT SHOWERS TO THE REGION,
ESPECIALLY NORTH OF HIGHWAY 50, ALTHOUGH IT WILL MOSTLY BE JUST
VIRGA AND INCREASED CLOUDS AS IT WOULD HAVE TO OVERCOME A VERY DRY
BOUNDARY LAYER. THE INCREASED CLOUDS WILL ALSO TEMPER THE WARMING ON
TUESDAY, SO LOWERED TEMPS SEVERAL DEGREES IN THE VALLEYS.
AFTER TUESDAY, WE STAY IN A DRY PATTERN THROUGH THE REST OF THE WEEK
AND INTO THE FOLLOWING WEEKEND. THERE IS SOME POTENTIAL OF A
SHORTWAVE DROPPING INTO THE PAC NW LATE FRIDAY, ACCORDING TO THE
ECMWF AND GEM, ALTHOUGH FORECASTER CONFIDENCE IS LOW REGARDING THIS
FEATURE. HIGH TEMPERATURES WILL GENERALLY REMAIN AROUND 50 DEGREES,
WITH LITTLE VARIATION BETWEEN THE DESERT VALLEYS AND SIERRA VALLEYS.
THERE IS A SLIGHT BIT OF HOPE FOR A BREAKDOWN OF THIS PERSISTENT DRY
PATTERN SOMETIME AROUND THE SECOND WEEK OF JANUARY, BUT FORECASTER
CONFIDENCE REMAINS VERY LOW AT TIME. HOON
AVIATION...
A FEW AREAS OF IFR FREEZING FOG REMAIN THROUGH 18Z THIS MORNING,
ESPECIALLY AROUND KLOL, KNFL, AND KSVE. A WEAK SHORTWAVE MOVING
THROUGH THE REGION TODAY WILL REDUCE FOG POTENTIAL TONIGHT. WINDS
WILL BECOME GUSTY FROM THE EAST-NORTHEAST OVER THE SIERRA RIDGES
TONIGHT INTO SUNDAY. OTHERWISE, VFR CONDITIONS ARE EXPECTED THROUGH
THE WEEKEND. POTENTIAL FOR VALLEY FOG RETURNS AGAIN SUNDAY NIGHT
INTO MONDAY MORNING. HOON
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...FREEZING FOG ADVISORY UNTIL 10 AM PST THIS MORNING NVZ004.
CA...FREEZING FOG ADVISORY UNTIL 10 AM PST THIS MORNING CAZ071.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS RENO NV
822 PM PST FRI DEC 27 2013
.UPDATE...
TROUGH PASSING ACROSS NORTHERN NEVADA THIS EVENING IS HAVING LITTLE
EFFECT ON THE STRONG VALLEY INVERSIONS DESPITE EXTENSIVE HIGH
CLOUD COVER. BEHIND THE SYSTEM SKIES WILL CLEAR RAPIDLY BY MIDNIGHT,
ESPECIALLY OVER NORTHEAST CALIFORNIA, THE TAHOE BASIN AND RENO-
CARSON. WINDS WILL REMAIN LIGHT UNTIL SATURDAY AFTERNOON WHEN A
SURFACE HIGH BUILDS INTO NORTHERN NEVADA. THIS WILL LEAD TO A
LIGHT NORTH TO NORTHEAST WIND ACROSS THE WESTERN NEVADA VALLEYS,
WHICH SHOULD BREAK THE INVERSIONS AND ERODE ANY REMAINING FREEZING
FOG.
FREEZING FOG HAS REDEVELOPED WITH VISIBILITY 1/2 OR LESS AT
FALLON, LOVELOCK AND SUSANVILLE THE LAST COUPLE HOURS. WILL ISSUE
A FREEZING FOG ADVISORY FOR PERSHING/CHURCHILL AND EASTERN LASSEN
COUNTIES AS THE FOG WILL REMAIN IN PLACE UNTIL THE NORTH WINDS
ARRIVE TOMORROW AFTERNOON. THE FREEZING FOG SHOULD EXPAND BACK
INTO AREAS IT DID LAST NIGHT, WHICH INCLUDES GERLACH, FERNLEY AND
SLIVER SPRINGS. BRONG
&&
.SYNOPSIS...
AREAS OF FOG AND LOW CLOUDS WILL PERSIST TONIGHT IN SOME LOWER
ELEVATION VALLEYS. OTHERWISE WEAK LOW PRESSURE WILL JUST BRING
HIGH CLOUDS THROUGH SATURDAY. WINDS MAY KICK UP ENOUGH TO MIX OUT
SOME VALLEY INVERSIONS SATURDAY, AND GUSTY NORTHEAST WINDS ARE
LIKELY IN THE SIERRA SATURDAY NIGHT. HIGH PRESSURE WILL BUILD BACK
INTO THE REGION NEXT WEEK WITH NO BIG STORMS ON THE HORIZON.
&&
.PREVIOUS DISCUSSION... /ISSUED 211 PM PST FRI DEC 27 2013/
SHORT TERM...
FOG AND LOW CLOUDS HAVE PERSISTED EAST OF SUSANVILLE AND NEAR
FALLON/LOVELOCK TODAY. HRRR GUIDANCE, WHICH PICKED UP ON FOG NEAR
FALLON, SUGGESTS IT WILL CONTINUE INTO THE EVENING HOURS IN THE NFL
AND CARSON SINK AREAS. HOWEVER FORECAST SOUNDINGS SHOW DRY AIR
MIXING INTO THE LOW LEVELS WHICH ALONG WITH SLIGHTLY INCREASED WINDS
MAY BE ENOUGH TO ERODE FOG/STRATUS. ADMITTEDLY FORECAST
CONFIDENCE IN FOG TRENDS IS ONLY MEDIUM - IT`S ALWAYS A TRICKY
THING TO FORECAST. BASED ON RECENT IMPROVING TRENDS IN VISIBILITY
AT LOL/NFL I`LL CANCEL THE FREEZING FOG ADVISORY, BUT IT IS NOT
OUT OF THE QUESTION WE MAY NEED TO REISSUE LATER THIS EVENING.
ELSEWHERE PATCHY FOG AND LOW CLOUDS ARE POSSIBLE, BUT REDEVELOPMENT
WILL BE LIMITED BY HIGH CLOUDS AHEAD OF APPROACHING SHORTWAVE. THAT
WAVE MAY KICK UP THE WINDS ENOUGH TO MIX OUT INVERSIONS IN ALL BUT
THE LOWEST VALLEYS ON SATURDAY. BEHIND THE WAVE, FLOW ALOFT TURNS NE
AND STRENGTHENS, LEADING TO A PERIOD OF GUSTY WINDS IN THE SIERRA
SATURDAY NIGHT. RIDGE BUILDS BACK IN STARTING SUNDAY, PROBABLY
LEADING TO MORE INVERSIONS AND HAZY CONDITIONS FOR THE VALLEYS EARLY
NEXT WEEK. GFS SHOWS LIGHT PRECIP ALONG THE NV/OR BORDER ASSOCIATED
WITH A PASSING JET STREAK MONDAY NIGHT. CONFIDENCE IN WHETHER THIS
PRECIP WILL IMPACT OUR CWA IS LOW, SO HAVE CONTINUED DRY FORECAST. CS
LONG TERM...TUESDAY THROUGH FRIDAY...
DRY PATTERN WITH LIGHT WINDS AND INVERSION CONDITIONS IS EXPECTED TO
PREVAIL THROUGH NEXT FRIDAY. THE LATEST GFS SHOWS THE RIDGE IN
CLOSER PROXIMITY TO WESTERN NV WHICH WOULD RESULT IN REDUCED
COVERAGE OF CIRRUS ESPECIALLY FOR THURS-FRI. THE ECMWF IS A LITTLE
FLATTER WITH THE RIDGE AND SPREADS HIGH LEVEL MOISTURE OVER THE
REGION AT TIMES, ESPECIALLY NORTH OF I-80. THE ECMWF ALSO BRUSHES A
WEAK SHORTWAVE ACROSS THE FAR NORTH BY NEXT FRIDAY EVENING, BUT
THESE FEATURES HAVE VARIED IN TIMING AND LOCATION WITH EACH RUN SO
WILL NOT ADD ANY PRECIP AT THIS TIME. MAX TEMPS SHOULD REMAIN NEAR
50 DEGREES THRU MOST OF NEXT WEEK. THE INVERSION APPEARS WEAKER ON
TUESDAY SO LOWER ELEVATIONS MAY BE A FEW DEGREES WARMER, OTHERWISE
LITTLE VARIATION IS EXPECTED WITH DAYTIME HIGHS BETWEEN WESTERN NV
AND THE SIERRA VALLEYS. MIN TEMPS WILL BE NEAR SEASONAL NORMALS
MAINLY IN THE LOWER-MID 20S FOR URBAN AREAS, AND TEENS FOR THE
TYPICALLY COOLER VALLEYS IN WESTERN NV AND NEAR THE SIERRA.
FOR THE FOLLOWING WEEK, THE GFS AND SOME OF ITS ENSEMBLE MEMBERS
ATTEMPT TO BREAK DOWN THE PERSISTENT RIDGE NEAR THE WEST COAST,
WITH A FEED OF PACIFIC MOISTURE REACHING THE SIERRA ROUGHLY BETWEEN
JANUARY 7 AND 11. SINCE THESE PROJECTIONS ARE SO FAR INTO THE FUTURE
AND THE ECMWF DOES NOT YET RUN INTO THIS TIME FRAME, THE CONFIDENCE
IN SEEING A CHANGE TO A WETTER PATTERN FOR EASTERN CA-WESTERN NV IS
STILL LOW. MJD
AVIATION...
AT THE MAIN TERMINALS, VFR CONDITIONS WILL PREVAIL THROUGH THIS
WEEKEND AS THE SHORTWAVE PASSAGE TONIGHT SHOULD PREVENT
REDEVELOPMENT OF FREEZING FOG. WINDS WILL GENERALLY REMAIN 10 KT OR
LESS.
A FEW STUBBORN AREAS OF LOW CLOUDS AND FZFG PRODUCING IFR/LIFR CIGS
AND/OR VSBY WILL BE SLOW TO DISSIPATE TONIGHT IN EASTERN LASSEN
COUNTY AFFECTING KSVE, EXTENDING EASTWARD ACROSS THE SMOKE CREEK
DESERT TO NEAR GERLACH. ALSO IMPACTED WILL BE THE WEST CENTRAL NV
BASIN INCLUDING KLOL AND KNFL. SOME LOCATIONS, ESPECIALLY IN
CHURCHILL COUNTY, MAY NOT CLEAR OUT UNTIL MIDDAY SATURDAY. MJD
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...FREEZING FOG ADVISORY UNTIL 10 AM PST SATURDAY NVZ004.
CA...FREEZING FOG ADVISORY UNTIL 10 AM PST SATURDAY CAZ071.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS TAUNTON MA
638 PM EST SUN DEC 29 2013
.SYNOPSIS...
INTENSIFYING LOW PRESSURE OVER LONG ISLAND THIS EVENING WILL PASS
OVER SOUTHEAST MASSACHUSETTS AND THEN OUT TO SEA TONIGHT. HEAVY
RAIN WILL ACCOMPANY THE LOW ALONG WITH GUSTY WINDS ALONG THE
COAST. RAIN WILL LIKELY CHANGE TO SNOW BEFORE ENDING ACROSS
SOUTHWEST NEW HAMPSHIRE WITH SOME ACCUMULATION POSSIBLE. MONDAY
BEGINS THE TRANSITION TO BITTERLY COLD CONDITIONS THIS WEEK. LOW
PRESSURE MOVING OUT OF THE PLAINS MAY BRING SNOW THURSDAY INTO
FRIDAY AS IT REDEVELOPS OFF THE COAST.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
640 PM UPDATE...
LOW PRESSURE OVER LONG ISLAND THIS EVENING AND WILL TRACK OVER SE
MA BEFORE MIDNIGHT. TEMPERATURES IN WARM SECTOR HAVE SHOT UP INTO
MID 50S AND WE SHOULD SEE SAME ACROSS BLOCK ISLAND...CAPE COD...
VINEYARD AND NANTUCKET FOR A BRIEF TIME EARLY TONIGHT.
21Z HRRR HAS VERY GOOD HANDLE ON RADAR TRENDS...TAKING BACK EDGE
OF PRECIPITATION TO EAST COAST BY 9 PM. SPED UP ENDING TIME AS A
RESULT.
NOT TOO CONFIDENT COLDER AIR WILL MAKE IT INTO SOUTHERN NH BEFORE
PRECIPITATION ENDS...BUT WITH GOOD BANDING SEEN ACROSS EASTERN NY
THIS COULD TRANSLATE ACROSS NORTHERN SECTIONS OF CHESHIRE AND
HILLSBOROUGH COUNTIES. SHOULD ALSO SEE SOME LIGHT ICING ACROSS
NW/N CENTRAL MA...MAINLY ACROSS HIGHER TERRAIN WHERE TEMPERATURES
WERE HOLDING NEAR FREEZING.
NO OTHER CHANGES BEYOND MIDNIGHT. CLEARING AND GUSTY W/NW WINDS
FOLLOW OVERNIGHT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
ARCTIC FRONT COMES THROUGH DURING THE AFTERNOON. 925 MB TEMPS FALL
FROM ABOUT 0C AT 12Z TO -13C BY 00Z. COLUMN IS FAIRLY DRY SO NOT
EXPECTING ANY PRECIP WITH FRONTAL PASSAGE. MUCH COLDER AND
BLUSTERY BEHIND THE FRONT FOR THE AFTERNOON.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...
* BITTERLY COLD FOR MUCH OF WEEK INCLUDING NEW YEAR/S
* COASTAL STORM POTENTIAL THU-FRI
DETAILS...
MODELS IN GOOD AGREEMENT THROUGH MIDWEEK AS UPPER LOW REMAINS OVER
SOUTHERN CANADA AND BRINGS REINFORCING SHOTS OF ARCTIC AIR. AT
SURFACE...HIGH PRESSURE BUILDS OVER REGION MON BEFORE ARCTIC COLD
FRONT APPROACHES TUE. ALTHOUGH MOISTURE IS LIMITED...WE SHOULD SEE
SCATTERED SNOW SHOWERS ACROSS INTERIOR AND SCATTERED FLURRIES
ELSEWHERE. REINFORCEMENT OF COLD ARRIVES IN TIME TO RING IN NEW
YEAR AS WIND CHILLS FALL INTO SINGLE NUMBERS AND TEENS...SO THOSE
WITH OUTDOOR PLANS WILL NEED TO BUNDLE UP.
FROM THERE MODELS BEGIN TO DIVERGE ON LARGE SCALE FLOW DUE TO
HANDLING OF SHORT WAVES COMING OUT OF ROCKIES. AS WPC DISCUSSION
NOTED...THIS HAS ORIGINS OVER ALASKA AND YUKON WHERE DATA IS
SPARSE...SO CONFIDENCE IN ANY ONE MODEL OR ENSEMBLE SOLUTION IS
LOW UNTIL THESE FEATURES CAN BE BETTER SAMPLED.
THAT SAID...OPERATIONAL MODELS AND THEIR ENSEMBLES SHOW TWO
DIFFERENT CAMPS WITH 12Z ECMWF HOLDING ON TO PRIMARY LOW AND
HAVING WEAK /RELATIVELY/ SECONDARY LOW PASSING INSIDE 40/70
BENCHMARK THU NIGHT. 12Z GFS AND CANADIAN HAVE SOMEWHAT STRONGER
SECONDARY LOW PASSING OUTSIDE BENCHMARK THU AFTERNOON. IN BOTH
CASES...SYSTEM IS BROAD ENOUGH SUCH THAT BOTH WOULD HAVE AN IMPACT
ON SOUTHERN NEW ENGLAND...EVEN MORE OFFSHORE GFS SOLUTION.
THERE ARE TWO FEATURES OF INTEREST THAT WILL NEED TO BE BETTER
RESOLVED THIS WEEK. ONE IS MID LEVEL DEFORMATION ZONE WHICH
APPEARS TO BE BEST SOURCE OF SYNOPTIC SCALE LIFT OVER REGION.
SECOND IS WHERE COASTAL FRONT EVENTUALLY SETS UP WHICH WILL BRING
ENHANCEMENT AT LOWER LEVELS. 12Z MODELS ARE ACTUALLY CLOSE WITH
THE POSITION OF FRONT...NEAR S COAST...BUT WE WOULD NOT BE
SURPRISED TO SEE THIS SHIFT A LITTLE FARTHER S IN FUTURE RUNS
GIVEN DEPTH OF ARCTIC AIR IN PLACE OVER NEW ENGLAND. NONETHELESS
POTENTIAL IS THERE FOR STRONG LIFT DUE TO TIGHT TEMPERATURE
GRADIENT ALONG BOUNDARY. IN THIS CASE IT DOES NOT LOOK LIKE
PRECIPITATION TYPE WILL BE AN ISSUE...WITH EXCEPTION OF NANTUCKET
AND POSSIBLY CAPE COD/VINEYARD.
MODEL CONSENSUS SUGGESTS THIS MAY BE A LONG DURATION EVENT AS
WELL WITH PERIODS OF SNOW FROM EARLY THU INTO FRI MORNING. MOST
OF ACCUMULATING SNOW WOULD OCCUR THU INTO EARLY FRI BEFORE SYSTEM
HEADS OUT TO SEA.
TO PUT STORM IN CONTEXT...GFS ENSEMBLES SHOW FAIRLY HIGH
PROBABILITY OF 0.50" PRECIPITATION IN 24 HRS...WHICH WOULD LEAD TO
SEVERAL INCHES OF SNOW GIVEN RATHER HIGH SNOW TO WATER RATIOS. TOP
CIPS ANALOGS /BASED ON GFS SOLUTION BEING CORRECT/ SHOW POTENTIAL
FOR 6 INCHES OR MORE OF SNOW.
ONE OTHER ITEM TO EVENTUALLY ADDRESS WILL BE POTENTIAL FOR COASTAL
FLOODING ALONG E MA COAST. TIDES WILL BE ASTRONOMICALLY HIGH
THU/FRI /AROUND 12 FT AT BOSTON/ SO STRONG ONSHORE WINDS COMBINED
WITH ROUGH SEAS OFFSHORE MAY LEAD TO FLOODING ISSUES.
ANOTHER SURGE OF ARCTIC AIR FOLLOWS IN WAKE OF SYSTEM FRI/SAT. IN
FACT WE WILL PROBABLY SEE COLDEST TEMPERATURES DURING THIS TIME
FRAME WITH LOWS DROPPING BELOW ZERO ACROSS INTERIOR AND INTO
SINGLE NUMBERS NEAR COAST SAT MORNING.
COLD BEGINS TO RETREAT SUN AS UPPER RIDGE BUILDS OVER NEW ENGLAND
AND SURFACE HIGH SHIFTS OFFSHORE. KEPT FORECAST DRY FOR NOW AS
MOISTURE AHEAD OF NEXT SYSTEM SHOULD REMAIN W OF RIDGE AXIS.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR TERM /THROUGH MONDAY/...MODERATE CONFIDENCE.
IFR PERSISTS THROUGH ABOUT 04Z ACROSS MOST OF AREA BEFORE
IMPROVEMENT TO MVFR AND THEN VFR OVERNIGHT.
MONDAY...VFR AND DRY CONDITIONS. GUSTY NW WINDS UP TO 25 KT
POSSIBLE.
KBOS TAF...HIGH CONFIDENCE. WINDS MAY BRIEFLY GUST FROM THE NORTH
00Z-03Z.
KBDL TAF...HIGH CONFIDENCE. RAPID IMPROVEMENT AFTER 03Z.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY.
MODERATE CONFIDENCE.
MON NIGHT THROUGH WED...VFR. GUSTY NW WINDS 20 TO 25 KT.
THU AND FRI...IFR IN SNOW. NE WINDS GUSTING TO 25 KT NEAR COAST.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TONIGHT...
GALE CENTER MOVES FROM NJ TO SOUTHEAST MA THIS EVENING AND THEN
OUT TO SEA THEREAFTER. GALES WILL ACCOMPANY THE LOW ALONG WITH
PERIODS OF HEAVY RAIN AND FOG REDUCING VSBY. ROUGH SEAS ACROSS THE
SOUTHERN OCEAN WATERS. QUICKLY IMPROVING 01Z-04Z FROM WEST TO
EAST.
MONDAY...
ARCTIC FRONT SWEEPS ACROSS THE WATERS DURING THE AFTERNOON. GUSTY
NNW WINDS BEHIND THE FRONT. LEFTOVER S SWELLS ACROSS SOUTH OCEAN
WATERS.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY.
MODERATE CONFIDENCE.
DIMINISHING WINDS AND SEAS MON NIGHT AS HIGH PRESSURE BUILDS OVER
WATERS. ARCTIC AIR MOVING OVER THE WATERS WILL GENERATE OCEAN
EFFECT SNOW SHOWERS AND SOME FREEZING SPRAY.
REINFORCEMENT OF ARCTIC AIR ARRIVES LATE TUE INTO WED WITH SCA
CONDITIONS EXPECTED AND CONTINUED POTENTIAL FOR FREEZING SPRAY.
GUSTS SHOULD PEAK AROUND 25 KT WITH SEAS BUILDING TO 5-6 FT
OFFSHORE.
CONFIDENCE DECREASES A BIT THU INTO FRI AS LOW PRESSURE MOVES
ACROSS OH VALLEY AND REDEVELOPS OFF MID ATLANTIC COAST. EXPECT
SECONDARY LOW TO TRACK SE OF NEW ENGLAND WITH INCREASING NE WINDS
THU AND THU NIGHT...BEFORE SHIFTING TO N/NW FRI AS LOW HEADS OUT
TO SEA. STRONGEST WINDS SHOULD AFFECT E MA WATERS...ESPECIALLY
AROUND CAPE ANN...WHERE GALES ARE MOST LIKELY. HOWEVER POTENTIAL
EXISTS FOR GALES ON ALL WATERS. SEAS SHOULD PEAK 10-12 FT OFFSHORE
AND 4-7 FT ON BAYS AND SOUNDS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
MAZ002>004-008-009-026.
WIND ADVISORY UNTIL 1 AM EST MONDAY FOR MAZ022>024.
WIND ADVISORY UNTIL 1 AM EST MONDAY FOR MAZ007.
NH...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NHZ011-
012-015.
RI...WIND ADVISORY UNTIL 1 AM EST MONDAY FOR RIZ008.
MARINE...GALE WARNING UNTIL 2 AM EST MONDAY FOR ANZ231>234.
SMALL CRAFT ADVISORY UNTIL 2 AM EST MONDAY FOR ANZ230.
SMALL CRAFT ADVISORY UNTIL 7 PM EST MONDAY FOR ANZ236.
GALE WARNING UNTIL 1 AM EST MONDAY FOR ANZ235-237.
GALE WARNING UNTIL 6 AM EST MONDAY FOR ANZ250-251.
GALE WARNING UNTIL 4 AM EST MONDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...NOCERA/JWD
NEAR TERM...NOCERA/JWD
SHORT TERM...NOCERA
LONG TERM...JWD
AVIATION...NOCERA/JWD
MARINE...NOCERA/JWD
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
945 PM EST SUN DEC 29 2013
.DISCUSSION...
COLD FRONT EXTENDING FROM FT MYERS TO CAPE CANAVERAL WILL PUSH THRU
OVERNIGHT UNDER THE INFLUENCE OF STRONG WRLY FLOW OVER THE GOMEX AND
THE DEEP SOUTH. RADAR SHOWS PRECIP HAS PUSHED OFFSHORE ALONG WITH
MOST OF THE DYNAMIC SUPPORT...LATEST RUC ANALYSIS SHOWS ONLY THE MID
LVL OMEGA FIELDS WITH LINGERING UPWARD VERTICAL MOTION ALONG THE
TREASURE COAST...MID LVL VORTICITY ACRS CENTRAL FL IS DIMINISHING
WITH THE UPR LVL DIVERGENCE FIELD EITHER NEUTRAL OR NEGATIVE.
EVENING RAOBS AND LATEST SFC OBS CONTINUE TO SHOW THE BULK OF THE
DRY AIR HAS YET TO PUSH INTO CENTRAL FL...L/M60S DEWPOINTS HAVE
WORKED THEIR WAY INTO KLEE/KORL/KISM BUT REMAIN IN THE U60S/L70S
ELSEWHERE...PWAT VALUES BTWN 1.6"-1.8" AT KTBW/KMFL...1.2" AT
KJAX...DECREASING TO 0.6" AT KTAE. SAT OBS SHOW AN EXTENSIVE STRATUS
DECK REMAINS OVER THE CWA THAT WILL GRADUALLY CLEAR FROM THE NW AS
THE DRIER AIR FILTERS INTO THE CWA. WINDS ALOFT BEHIND THE FRONT ARE
TOO STRONG FOR ANY SIG FOG TO DEVELOP OVERNIGHT...COULD SEE SOME
PATCHY FOG OVER THE SRN CWA IN THE VCNTY OF THE FRONT BUT NO SIG
REDUCTIONS TO VSBY.
DEEPER MOISTURE COULD ALLOW ADDITIONAL LIGHT RAIN TO DVLP ALONG THE
TREASURE COAST AND AROUND LAKE OKEECHOBEE OVERNIGHT AS ISENTROPIC
ANALYSIS DOES SHOW THE POTENTIAL FOR WEAK LIFT TO DVLP. HOWEVER...
ANY ADDITIONAL PRECIP WILL BE LIMITED TO LESS THAN A TENTH OF AN
INCH. WILL UPDATE THE ZONES TO REMOVE FOG OVER THE S AND TO LOWER
POPS TO AOB 20PCT.
&&
.AVIATION...
THRU 30/09Z...COLD FRONT S OF KTIX-KISM WILL PUSH S OF KSUA-KOBE
WITH SFC WNDS VEERING FROM W/SW TO NW AOB 10KTS WITH THE PASSAGE...
MVFR CIGS BTWN FL010-020 DVLPG ALL SITES WITH OCNL PDS OF IFR CIGS N
OF KTIX-KISM...CONTG THRU 30/14Z. BTWN 30/14Z-30/16Z...CIGS LIFTG TO
ABV FL030 WITH SFC WNDS VEERING TO N/NW AOB 10KTS.
&&
.MARINE...
CONDITIONS SLOWLY IMPROVING THIS EVNG AS EVIDENCED BY THE LATEST
OBS FROM THE DATA BUOYS/C-MAN STATIONS. WINDS W/SW 5-10KTS NEARSHORE
AND 10-15KTS OFFSHORE...SEAS 3-4FT NEARSHORE AND 4-5FT OFFSHORE WITH
DOMINANT PDS BTWN 8-10SEC. SFC/BNDRY LYR WINDS WILL VEER TO THE NW
DIMINISHING TO AOB 12KTS OVERNIGHT AS A COLD FRONT EXTENDING FROM FT
MYERS TO CAPE CANAVERAL PUSHES THRU THE LCL ATLC...SEAS SUBSIDING TO
2-4FT NEARSHORE AND 3-5FT OFFSHORE. CURRENT GRID FCST IN LINE WITH
THE CURRENT CONDITIONS WITH SEAS SUBSIDING BY A FOOT AREAWIDE FROM
THIS AFTN. WILL DROP THE CAUTIONARY STATEMENT OFFSHORE WITH THE
EVENING PACKAGE.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...VOLKMER
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
924 PM EST Sun Dec 29 2013
.NEAR TERM [Through Tonight]...
Low clouds have been slow to clear over portions of the area so
far this evening, and a large patch remains over the middle of
the forecast area. Most model guidance has a poor handle on this
patch, and only the HRRR and NARRE appear to be aware of its
existence. The 00z KTAE sounding (although launched before the
clouds made it to Tallahassee) shows an extremely thin moist layer
between 1500-2000 ft, so perhaps the layer is too thin for the
vertical resolution of most models to capture it. The HRRR keeps
the low clouds around most of the night with a slow erosion from
north to south late tonight. However, as it erodes the low clouds,
it develops areas of fog around its edges. There is some evidence
of this already happening with a few sites outside of our forecast
area already showing reduced visibilities.
The evening update will side more with the HRRR given its superior
initialization and observational evidence of its forecast
verifying closer to reality. Sky grids have been updated to show
more cloud cover overnight with patchy fog around the edges where
the forecast sky grids are less than or equal to 50%.
&&
.AVIATION...
[Through 00Z Tuesday] The low level cigs which were supposed to
dissipate never quite did before sunset, which has only compounded
the problem of the trapped in low level moisture. This moisture is
already forming a new saturated inversion which by all accounts
will lead to a night of MVFR or worse Cigs at most of the
terminals, with IFR conditions a distinct possibility. This will
may be most likely at DHN, where the once solid Cigs will likely
break, with fog and even lower Cigs building in behind them. The
main question is how long will the MVFR or worse conditions
persist, and this could range anywhere from late tonight into the
early morning hours of Monday, and will have to defer to the next
shift to refine the timing of this rapidly evolving fcst.
&&
.HYDROLOGY...
Most areas had rainfall accumulations of 1-2 inches in the past 24
hours which has led to elevated rivers and creeks. The
Apalachicola River at Blountstown is at minor flood stage and is
forecast to remain there through at least January 3rd with
releases from Woodruff Dam. The Choctawhatchee River is forecast
to reach minor flood stage at Caryville and Bruce this week.
Several other area rivers and creeks are forecast to crest in
action stage but remain below minor flood stage at this time.
The most up to date, specific river forecast information can be
found on the AHPS page at
http:/water.weather.gov/ahps2/index.php?wfo=tae.
&&
.Prev Discussions [130 PM EST]...
.SHORT TERM [Monday Through Tuesday Night]...
Monday should be a dry day with seasonal temperatures. Another cold
front will cross the region Monday night. Some weak DPVA and mid
level frontogenetic forcing will result in the possibility of some
light rain accompanying this frontal passage. Lower levels will
remain fairly dry, so any rain that falls will be light. PoPs were
kept in the chance category. Temps will be a few about 5 degrees
cooler across the forecast area on Tuesday behind the front. A vort
lobe will be shearing out over TX on Tuesday. However, there will be
enough energy to induce weak cyclogenesis over the southwestern Gulf
of Mexico. Some weak overrunning over the stalled frontal boundary
to our south could result some very light rain again on Tuesday
night. We kept PoPs in the slight chance category for now to account
for the weak forcing.
.LONG TERM [Wednesday Through Sunday]...
A progressive upper level pattern will persist across the CONUS from
midweek through the weekend. One long wave trough will swing past
the area on Thursday. While most of the energy associated with the
trough will be to our north, some of that TX energy mentioned
earlier will work its way across the northern Gulf of Mexico. The
models are still not in very good agreement in depicting how the
surface low in the Gulf will evolve. The NAM is most aggressive with
its forcing for ascent with QPF well above a model consensus. The
GFS is the driest scenario. We always favor a model blend in the
long term periods and show PoPs increasing gradually from Wednesday
into Thursday. A strong cold front will shunt any precipitation
south of the area Thursday night. The airmass behind this front will
have modified considerably from what it is now, but will still be
pretty chilly. Look for temps to be well below climatology on Friday
and Friday night. Highs Friday will only be in the 50s with
overnight lows dropping a few degrees below freezing. Friday night
has the potential to be the coldest night of the winter thus far,
which is not saying much. We are not anticipating a hard freeze at
this time. A moderating trend in temps is forecast for the weekend
with slight rain chances returning to the forecast on Sunday ahead
of the next frontal system.
.MARINE...
Light to moderate offshore winds are expected through Tuesday night.
Winds speeds may briefly reach cautionary levels Tuesday morning and
again Tuesday night. Winds will shift to the east by Wednesday. A
strong cold front will shift winds back to offshore Thursday night
with wind speeds increasing to advisory levels in its wake.
.FIRE WEATHER...
Relative humidity values will remain well above critical values at
least for the next several days. No fire weather concerns
anticipated.
&&
.PRELIMINARY POINT TEMPS/POP...
Tallahassee 45 65 43 61 41 / 0 10 30 20 20
Panama City 47 64 48 60 45 / 0 10 40 20 20
Dothan 42 61 42 55 38 / 0 20 20 10 20
Albany 42 62 41 58 36 / 0 10 20 10 20
Valdosta 44 64 44 61 39 / 0 10 30 20 20
Cross City 48 67 46 66 41 / 0 10 30 20 20
Apalachicola 47 63 49 61 46 / 0 10 40 20 20
&&
.TAE Watches/Warnings/Advisories...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...DVD
SHORT TERM...Wool
LONG TERM...Wool
AVIATION...Gould
MARINE...Wool
FIRE WEATHER...Barry
HYDROLOGY...DVD/Weston
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1128 AM CST SAT DEC 28 2013
.DISCUSSION...
339 AM CST
THE ROLLER COASTER RIDE IN TEMPERATURES THIS FINAL WEEKEND OF 2013 IS
THE PRIMARY FORECAST CHALLENGE...WITH A STRIKING 50 DEGREE
DIFFERENCE FROM HIGHS THIS AFTERNOON TO MORNING TEMPERATURES ON
MONDAY EXPECTED. THE UPCOMING SHARP DIP ON OUR RIDE WILL TAKE US
INTO THE FIRST DAYS OF THE NEW YEAR WITH ANOMALOUS COLD SET FOR
NEXT WEEK. TEMPERATURES AND SNOW POTENTIAL IN THAT PATTERN WERE
THE NEXT CHALLENGES WITH THIS FORECAST.
TODAY...SOUTHWEST FLOW CONTINUES OVER THE AREA THIS MORNING WITH
TEMPERATURES AT OR ABOVE FREEZING AT 330 AM ACROSS MOST CWA
COMMUNITIES. THIS MILD STARTING POINT OFFERS A NICE SPRINGBOARD FOR
TEMPERATURES ALREADY SET TO BE THE WARMEST SINCE DECEMBER 4TH. AS
LOW PRESSURE FROM ND EARLY THIS MORNING MOVES TO WESTERN WI BY EARLY
EVE...A WARM SECTOR WITH SOUTHWEST FLOW WILL BE IN PLACE ACROSS THE
AREA. LITTLE IN THE WAY OF CLOUDS IS SEEN ON MORNING SATELLITE AND
UPPER LEVEL SUPPRESSION IS EVEN INDICATED ON WATER VAPOR WHICH LOOKS
TO REMAIN THROUGH MIDDAY FURTHER ALLOWING FOR A SUN-FILLED SKY. THE
SNOW PACK PROVIDED A 10 TO AS MUCH AS 15 DEGREE TEMPERATURE GRADIENT
ACROSS THE FORECAST AREA YESTERDAY AND WOULD EXPECT NEAR THAT TODAY.
HAVE GUIDED BY YESTERDAYS LAST VISIBLE IMAGERY AS WELL AS NOHRSC
DATA FOR SNOW COVER INFLUENCE. THE 00Z/06Z NAM LOOKS ABOUT 1-1.5C
WARM ON 925MB TEMPS BASED ON LAST EVES SOUNDINGS...SO HAVE GONE
CLOSER TO THE 8-9C PROJECTED OVER THE AREA BY MOST OTHER GUIDANCE.
CLIMATOLOGY SUGGESTS LOW-MID 50S WITH THIS AS AN AVERAGE...AND EVEN
LOCAL ON-THE-FLY RESEARCH DONE EARLIER IN THE WEEK BY A COLLEAGUE
INDICATED 54 AS AN AVERAGE AT ORD WITH THESE 925MB TEMPS AND SW FLOW.
IT LOOKS LIKE AREAS JUST EAST OF THE SNOW PACK...INCLUDING
CHICAGO...WILL STILL HAVE SOME MODIFICATION OF THE SW FLOW BASED ON
PARCEL TRAJECTORIES OVER SNOW PACK SO HAVE UNDERCUT THAT 54 BY A
HANDFUL OF DEGREES...BUT DO EXPECT THE 50 DEGREE ISOTHERM TO BISECT
THE METRO AREA WITH THE SOUTH SIDE WARMING THE MOST. EVEN THE 13KM
RAP FORECAST TEMPS THROUGH THIS AFTERNOON INDICATE THIS TYPE OF
TREND. AREAS SOUTH OF INTERSTATE 80 AND EAST OF ILLINOIS 47 SHOULD
BE ABLE TO REALIZE THOSE MID 50S.
TONIGHT INTO SUNDAY...HAVE GUIDED WITH THE SLIGHTLY FASTER NAM
TIMING ON THE COLD FRONTAL PASSAGE...BUT ALL IN ALL GUIDANCE/MOS IS
BASICALLY WITHIN 3 HRS OF FROPA FOR ANY ONE POINT. THE UPPER WAVE OF
THIS SYSTEM IS WELL-DEFINED ON WATER VAPOR OVER MT EARLY THIS
MORNING AND ALREADY 160M HEIGHT FALLS WERE OBSERVED AT 500MB WITH
IT LAST NIGHT. THE FRONT IS DRIVEN BY THE COLLECTIVE STRONG COLD
AIR ADVECTION...THICKNESS FALLS...AND SURFACE PRESSURE RISES AND
SHOULD HAVE GOOD MOMENTUM TO DRIVE IT. THE MERCURY WILL DROP
THROUGH THE DAY SUNDAY WITH WIND CHILLS LIKELY TO FALL BELOW ZERO
ACROSS NORTH CENTRAL IL DURING THE AFTERNOON. OVERCAST STRATOCU IS
EXPECTED IMMEDIATELY IN THE WAKE OF FROPA AS INDICATED BY FORECAST
MODEL SOUNDINGS. THE DEPTH OF THE SATURATED LAYER WITH RESPECT TO
ICE IS FAIRLY SHALLOW AT THE TOP OF THE MIXED LAYER...AND OMEGA IS
NOT FORECAST TO BE THE BEST FOR WIDESPREAD SNOW SHOWERS.
HOWEVER...UPPER LEVEL FORCING ALONG THE 650-850MB BAROCLINIC ZONE
BEHIND THE FRONT MAY ALSO HELP FOR SOME LIGHT SNOW MORE SO INTO
THE AFTERNOON. GIVEN THE DEGREE OF COLD AIR ADVECTION...THIS
CONTINUES TO LOOK LIKE A POST-FRONTAL AIR MASS THAT WOULD HAVE SOME
LIGHT SNOW/SNOW SHOWERS...WITH BEST CHANCES IN THE NORTHERN
FORECAST AREA. SO HAVE CONTINUED THAT IN THE FORECAST ON SUNDAY
AND EARLY SUNDAY EVE. LAKE EFFECT TRAJECTORIES CONTINUE TO FAVOR
JUST EAST OF OUR NW INDIANA COUNTIES FOR ANY SHOWERS DURING
SUNDAY NIGHT. TEMPERATURES SUNDAY NIGHT ARE STILL FORECAST TO HEAD
BELOW ZERO ACROSS A LARGE PART OF THE IL FORECAST AREA.
WIND CHILL HEADLINE POTENTIAL...SUSTAINED WIND SPEEDS AROUND 15
MPH TO START SUNDAY EVE WILL ONLY VERY GRADUALLY DIMINISH DURING
SUNDAY NIGHT. WHILE DEFINITE ADVISORY CRITERIA WILL BE MET...AT
THIS POINT WARNING CRITERIA IS NOT FORECAST ALTHOUGH IT MAY BE
CLOSE IN NORTH CENTRAL IL SUNDAY NIGHT INTO EARLY MONDAY. SO HAVE
NOT OPTED ANY WATCH AT THIS TIME. IN ADDITION...WIND CHILL
ADVISORY CRITERIA MAY BE CLOSE AGAIN TUESDAY NIGHT INTO EARLY
WEDNESDAY.
NEXT WEEK...A NORTHWEST JET AROUND 150KT WILL RE-INTENSIFY THE
HUDSON BAY TROUGH WITH 500MB HEIGHTS AT ITS CENTER FORECAST TO DIP
TO AN EYE-OPENING LOW 481DM. THIS WILL ALLOW FOR ESTABLISHED
NORTHWEST FLOW OVER THE MIDWEST AND WITH THAT ONCE AGAIN COMES
SEVERAL SMALL MID-LEVEL PERTURBATIONS CAPABLE OF SNOW. AS THIS
PAST WEEK SHOWED...THESE ARE CHALLENGING TO FORECAST SPECIFICS
WELL IN ADVANCE. OVERALL...THE PATTERN WILL BE FAVORABLE FOR THESE
TO BRING MINOR ACCUMULATIONS OVER THE PATH THEY TAKE...JUST GIVEN
A DEEPER DENDRITIC GROWTH ZONE ABLE TO BE SATURATED WITH EACH
IMPULSE. MONDAY NIGHT AND AGAIN TUESDAY NIGHT AT THIS TIME ARE THE
AVERAGES IN GUIDANCE FOR POTENTIALLY LIGHT ACCUMULATING
SNOW...BUT AGAIN QUITE A BIT COULD CHANGE WITH THESE. FOR
TEMPERATURES...EACH IMPULSE LOOKS TO KEEP THE COLD AIR IN PLACE
WITH ONLY VERY MINIMAL WARM AIR ADVECTION IN ADVANCE OF ANY OF
THESE. HAVE UNDERCUT A MODEL MEAN SLIGHTLY OVER THE NORTHWEST
FORECAST AREA WHERE SNOW PACK STILL SHOULD HAVE GREATER INFLUENCE
TO KEEP TEMPS DOWN. ALL IN ALL THOUGH VERY LITTLE CHANGES TO
PREVIOUS FORECAST FOR NEXT WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SOUTH-SOUTHWEST WINDS GUSTING NEAR 20 KT THIS AFTERNOON.
* COLD FRONTAL PASSAGE EARLY SUNDAY MORNING.
* GUSTY NORTHWEST WINDS AROUND 25 KT SUNDAY.
* MVFR CIGS LIKELY WITH LGT SNOW/SNOW SHOWERS PRODUCING MVFR/IFR VSBYS.
RATZER
//DISCUSSION...UPDATED 18Z...
RELATIVELY QUIET AVIATION WEATHER ACROSS THE FORECAST AREA THIS
AFTERNOON. LOW PRESSURE JUST NORTH OF KFSD WILL CONTINUE TO MOVE
EAST ACROSS MINNESOTA AND WISCONSIN THROUGH THIS EVENING...WITH
SURFACE PRESSURE FALLS AND RELATIVELY TIGHT PRESSURE GRADIENT
INDUCING WINDS FROM 210-230 DEGREES GUSTING TO NEAR 20 KT THIS
AFTERNOON. FORECAST SOUNDINGS DEPICT RATHER SHALLOW MIXED LAYER
WITH WARM AIR ALOFT...WHICH SUGGESTS GUSTS WILL DECREASE EARLY
THIS EVENING WHILE SUSTAINED SPEEDS HOLD IN THE 10-15 KT RANGE
UNTIL GRADIENT BEGINS TO WEAKEN IN ADVANCE OF COLD FRONTAL TROUGH
LATER TONIGHT. LATEST MODEL RUNS MAINTAIN FRONTAL PASSAGE IN THE
10-12Z RANGE EARLY SUNDAY MORNING...WITH A WIND SHIFT INITIALLY TO
THE WEST...AND THEN SHIFTING NORTHWEST AND INCREASING IN SPEED WITHIN
A FEW HOURS. DEEPENING MIXED LAYER WITH STRONG COLD ADVECTION WILL
AID IN MIXING STRONGER GUSTS AROUND 25 KT BUT OCCASIONALLY A
LITTLE HIGHER TO THE SURFACE BY MID- MORNING AND CONTINUING
THROUGH THE REST OF THE DAY.
STRONG COLD ADVECTION WILL HELP MOISTEN THE COLUMN AS MID-LEVEL
TROUGH APPROACHES...RESULTING IN MVFR STRATOCU DEVELOPMENT BEHIND
THE FRONT. FORECAST SOUNDINGS INDICATE CLOUD BASES AROUND 1500 FT
AGL...WITH LIGHT SNOW/SNOW SHOWERS BECOMING LIKELY AS THE COLUMN
MOISTENS AND COOLS DURING THE LATER MORNING/AFTERNOON HOURS.
DEEPER MOISTURE AND LIFT ACROSS THE AREA DURING THE AFTERNOON
SHOULD SUPPORT AT LEAST OCCASIONAL VISIBILITY REDUCTION THROUGH
MVFR/IFR RANGE...ESPECIALLY AS LOW LEVELS COOL INTO BETTER CRYSTAL
PRODUCTION TEMPERATURES.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN WIND TRENDS AND VFR CONDITIONS PREVAILING
UNTIL EARLY SUNDAY MORNING.
* MEDIUM-HIGH CONFIDENCE IN MVFR CIGS AROUND 1500 FT DEVELOPING
BEHIND COLD FRONT SUNDAY.
* MEDIUM CONFIDENCE IN -SN/SHSN TIMING AND VSBY.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...MVFR CIGS...BECOMING VFR OVERNIGHT.
MONDAY...VFR...BECOMING MVFR MON NIGHT WITH A CHANCE OF SNOW.
TUESDAY...MVFR CIGS. CHANCE OF LIGHT SNOW.
WEDNESDAY...MVFR CIGS. CHANCE OF LIGHT SNOW.
THURSDAY...VFR.
FRIDAY...VFR. SLIGHT CHANCE OF SNOW SHOWERS.
TRS
&&
.MARINE...
441 AM CST
A STRONG SW FLOW WILL DEVELOP TODAY AS LOW PRESSURE MOVES SE FROM
ND TO WI. HOWEVER...WITH STRONG WARM AIR ADVECTION CONTINUING AND
THE WATER IN THE LOWER TO MID 30S F THE SURFACE WILL BE DECOUPLED
FROM THE STRONG FLOW JUST ABOVE THE BASE OF THE TEMPERATURE
INVERSION. NORTHWEST GALES OF 35 TO 40 KT WILL ARRIVE DURING THE
PREDAWN HOURS OF SUNDAY ON THE N END OF LAKE MICHIGAN...AND THE
S END BY MID MORNING SUNDAY AS THE LOW MOVES E ACROSS FAR N LAKE
MI INTO NORTHERN LOWER MI OVERNIGHT AND THE TRAILING COLD FRONT
SWEEPS SE ACROSS THE LAKE OVERNIGHT TONIGHT AND EARLY SUN MORNING.
ARCTIC AIR WILL OVERSPREAD THE UPPER GREAT LAKES BEHIND THE COLD
FRONT RESULTING IN A VERY UNSTABLE CONDITION DUE TO THE LARGE
CONTRAST BETWEEN WATER AND AIR TEMPERATURE. THIS WILL RESULT IN
EFFICIENT TRANSFER OF STRONG WINDS RIGHT DOWN TO THE LAKE
SURFACE. IN ADDITION...STRONG HIGH PRESSURE WILL BE BUILDING SE
FROM S SASKATCHEWAN ACROSS THE N AND CENTRAL PLAINS OVERNIGHT
TONIGHT AND SUN. WINDS WILL GRADUALLY DIMINISH SUN NIGHT AS THIS
HIGH MOVES TO THE UPPER AND MID MS VALLEY.
A GALE WARNING IS UP FOR ALL THE OPEN WATERS OF THE LAKE...STARTING
IN THE PREDAWN HOURS ON THE N...AND MID MORNING ON THE S. A GALE
WARNING IS ALSO IN EFFECT FOR THE NEARSHORE FROM GARY TO MI CITY .
A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED FROM WINTHROP HARBOR
TO GARY DURING SUN AND SUN NIGHT.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...4 AM
SUNDAY TO 6 PM SUNDAY.
GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ744-
LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-
LMZ878...9 AM SUNDAY TO 9 PM SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
1111 AM CST Sat Dec 28 2013
.DISCUSSION...
ISSUED 936 AM CST Sat Dec 28 2013
Temperature trends remain the primary forecast concern for today.
Already have widespread upper 30s and lower 40s over the CWA, even
in the snow covered northwest. Most of the model guidance
continues to run too cool. Have favored the HRRR which looks good
in most areas, except it also is too cool where the snow is
currently in place. Morning cooperative weather observations, as
well as visible satellite imagery, show 1-2 inches still on the
ground early this morning across Knox, Stark and western
Marshall Counties. Should still get in the upper 40s there, but
50-55 will be common elsewhere this afternoon. Have sent updated
grids to reflect the latest trends, but the worded forecasts still
look good.
Geelhart
&&
.AVIATION...
ISSUED 1110 AM CST Sat Dec 28 2013
Main concern remains in the latter part of the TAF period, as a
cold front passes through. Through 06Z, will gradually see high
clouds move in and slowly lower. The front itself will be sweeping
across the central Illinois TAF sites between 10-14Z. Ceilings
expected to fall below 2000 feet with the passage of the front,
remaining there the rest of the TAF period. Northwest winds
expected to gust to around 20 knots behind the front as Arctic air
rushes into the area.
Geelhart
&&
.PREV DISCUSSION...
ISSUED 330 AM CST Sat Dec 28 2013
SHORT TERM...Today through Monday
00Z short range models are in good agreement through Monday and
will use a blend. Polar vortex over northeast Canada through mid
week to have northern stream short waves passing through the
Midwest and Great Lakes region around Monday night into Tue night
and another one around Thu. Models differ with timing and
placement of these features and will use a blend of models and
previous forecast for this package.
Another mild day today expected across central and southeast IL
with some areas getting in the low to mid 50s. Then an arctic cold
front near the US/Canadian border to pass SE through IL later
tonight into Sunday morning. Just a small chance of light
precipitation Sunday (mainly light snow or flurries). More
importantly, this front to usher in another arctic air mass Sunday
and Sunday night and will stick around through Thursday night.
Early morning surface map shows 1030 mb high pressure over the
southeast states while 1004 mb low pressure along the MT/ND and
Canadian border. SW winds over IL keeping milder temps in the mid
to upper 30s early this morning with nearly clear skies. 568 dm
500 mb low over west Texas has high/cirrus clouds spreading
northward into the mid MS valley including far southern IL and KY
early this morning. Some of these thin high clouds to spread into
central and especially southeast IL today with a fair amount of
sunshine still expected today. SW winds 10-15 mph and gusts 15-20
mph to boost highs in the low to mid 50s this afternoon, expected
upper 40s NW of the IL river where a light snow cover remains
especially over Knox and Stark counties.
Arctic cold front near the US/Canadian border to push SE through
the IL river valley late tonight and have temps dropping into the
upper teens and lower 20s NW of the IL river by dawn while milder
low to mid 30s over eastern/SE IL for lows tonight. Clouds to
increase during tonight with a fair amount of clouds Sunday as
arctic front pass SE through eastern/SE IL Sunday morning. Not
much moisture to work with so think mainly small chance of very
light precipitation Sunday behind the front in from of light snow
or flurries, though light rain possible Sunday morning over SE IL.
Highs Sunday in the morning range from the lower 20s NW of the IL
river to the upper 30s and lower 40s in southeast IL with falling
temps through the day behind the arctic front.
Very cold air advects into IL Sunday night into Monday with wind
chills likely getting to 15 to 20 below zero north of I-72
overnight Sunday night into Monday morning and will likely need a
wind chill advisory as event gets closer. Lows Sunday night to be
in the single digits below from I-55 NW with highs Monday from 8-14
north of I-72.
LONG TERM...Monday night through Friday
Very cold conditions expected to continue Monday night through Thu
night with polar vortex in northeast Canada and strong upper level
trof over the region and reinforced on Thursday. A northern stream
short wave approaches northern counties during Monday night with
slight chance of light snow or flurries and gets further into
central IL Tue and Tuesday night before exiting on Wed. Not
expecting much accumulations of snow at this point in dry air mass.
Could be another chance of flurries on Thursday with strong upper
level trof and possible short wave moving thru region. Large upper
level trof shifts east of IL Fri/Sat with temps moderating closer
to normal with dry conditions expected.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
956 AM CST SAT DEC 28 2013
.DISCUSSION...
339 AM CST
THE ROLLER COASTER RIDE IN TEMPERATURES THIS FINAL WEEKEND OF 2013 IS
THE PRIMARY FORECAST CHALLENGE...WITH A STRIKING 50 DEGREE
DIFFERENCE FROM HIGHS THIS AFTERNOON TO MORNING TEMPERATURES ON
MONDAY EXPECTED. THE UPCOMING SHARP DIP ON OUR RIDE WILL TAKE US
INTO THE FIRST DAYS OF THE NEW YEAR WITH ANOMALOUS COLD SET FOR
NEXT WEEK. TEMPERATURES AND SNOW POTENTIAL IN THAT PATTERN WERE
THE NEXT CHALLENGES WITH THIS FORECAST.
TODAY...SOUTHWEST FLOW CONTINUES OVER THE AREA THIS MORNING WITH
TEMPERATURES AT OR ABOVE FREEZING AT 330 AM ACROSS MOST CWA
COMMUNITIES. THIS MILD STARTING POINT OFFERS A NICE SPRINGBOARD FOR
TEMPERATURES ALREADY SET TO BE THE WARMEST SINCE DECEMBER 4TH. AS
LOW PRESSURE FROM ND EARLY THIS MORNING MOVES TO WESTERN WI BY EARLY
EVE...A WARM SECTOR WITH SOUTHWEST FLOW WILL BE IN PLACE ACROSS THE
AREA. LITTLE IN THE WAY OF CLOUDS IS SEEN ON MORNING SATELLITE AND
UPPER LEVEL SUPPRESSION IS EVEN INDICATED ON WATER VAPOR WHICH LOOKS
TO REMAIN THROUGH MIDDAY FURTHER ALLOWING FOR A SUN-FILLED SKY. THE
SNOW PACK PROVIDED A 10 TO AS MUCH AS 15 DEGREE TEMPERATURE GRADIENT
ACROSS THE FORECAST AREA YESTERDAY AND WOULD EXPECT NEAR THAT TODAY.
HAVE GUIDED BY YESTERDAYS LAST VISIBLE IMAGERY AS WELL AS NOHRSC
DATA FOR SNOW COVER INFLUENCE. THE 00Z/06Z NAM LOOKS ABOUT 1-1.5C
WARM ON 925MB TEMPS BASED ON LAST EVES SOUNDINGS...SO HAVE GONE
CLOSER TO THE 8-9C PROJECTED OVER THE AREA BY MOST OTHER GUIDANCE.
CLIMATOLOGY SUGGESTS LOW-MID 50S WITH THIS AS AN AVERAGE...AND EVEN
LOCAL ON-THE-FLY RESEARCH DONE EARLIER IN THE WEEK BY A COLLEAGUE
INDICATED 54 AS AN AVERAGE AT ORD WITH THESE 925MB TEMPS AND SW FLOW.
IT LOOKS LIKE AREAS JUST EAST OF THE SNOW PACK...INCLUDING
CHICAGO...WILL STILL HAVE SOME MODIFICATION OF THE SW FLOW BASED ON
PARCEL TRAJECTORIES OVER SNOW PACK SO HAVE UNDERCUT THAT 54 BY A
HANDFUL OF DEGREES...BUT DO EXPECT THE 50 DEGREE ISOTHERM TO BISECT
THE METRO AREA WITH THE SOUTH SIDE WARMING THE MOST. EVEN THE 13KM
RAP FORECAST TEMPS THROUGH THIS AFTERNOON INDICATE THIS TYPE OF
TREND. AREAS SOUTH OF INTERSTATE 80 AND EAST OF ILLINOIS 47 SHOULD
BE ABLE TO REALIZE THOSE MID 50S.
TONIGHT INTO SUNDAY...HAVE GUIDED WITH THE SLIGHTLY FASTER NAM
TIMING ON THE COLD FRONTAL PASSAGE...BUT ALL IN ALL GUIDANCE/MOS IS
BASICALLY WITHIN 3 HRS OF FROPA FOR ANY ONE POINT. THE UPPER WAVE OF
THIS SYSTEM IS WELL-DEFINED ON WATER VAPOR OVER MT EARLY THIS
MORNING AND ALREADY 160M HEIGHT FALLS WERE OBSERVED AT 500MB WITH
IT LAST NIGHT. THE FRONT IS DRIVEN BY THE COLLECTIVE STRONG COLD
AIR ADVECTION...THICKNESS FALLS...AND SURFACE PRESSURE RISES AND
SHOULD HAVE GOOD MOMENTUM TO DRIVE IT. THE MERCURY WILL DROP
THROUGH THE DAY SUNDAY WITH WIND CHILLS LIKELY TO FALL BELOW ZERO
ACROSS NORTH CENTRAL IL DURING THE AFTERNOON. OVERCAST STRATOCU IS
EXPECTED IMMEDIATELY IN THE WAKE OF FROPA AS INDICATED BY FORECAST
MODEL SOUNDINGS. THE DEPTH OF THE SATURATED LAYER WITH RESPECT TO
ICE IS FAIRLY SHALLOW AT THE TOP OF THE MIXED LAYER...AND OMEGA IS
NOT FORECAST TO BE THE BEST FOR WIDESPREAD SNOW SHOWERS.
HOWEVER...UPPER LEVEL FORCING ALONG THE 650-850MB BAROCLINIC ZONE
BEHIND THE FRONT MAY ALSO HELP FOR SOME LIGHT SNOW MORE SO INTO
THE AFTERNOON. GIVEN THE DEGREE OF COLD AIR ADVECTION...THIS
CONTINUES TO LOOK LIKE A POST-FRONTAL AIR MASS THAT WOULD HAVE SOME
LIGHT SNOW/SNOW SHOWERS...WITH BEST CHANCES IN THE NORTHERN
FORECAST AREA. SO HAVE CONTINUED THAT IN THE FORECAST ON SUNDAY
AND EARLY SUNDAY EVE. LAKE EFFECT TRAJECTORIES CONTINUE TO FAVOR
JUST EAST OF OUR NW INDIANA COUNTIES FOR ANY SHOWERS DURING
SUNDAY NIGHT. TEMPERATURES SUNDAY NIGHT ARE STILL FORECAST TO HEAD
BELOW ZERO ACROSS A LARGE PART OF THE IL FORECAST AREA.
WIND CHILL HEADLINE POTENTIAL...SUSTAINED WIND SPEEDS AROUND 15
MPH TO START SUNDAY EVE WILL ONLY VERY GRADUALLY DIMINISH DURING
SUNDAY NIGHT. WHILE DEFINITE ADVISORY CRITERIA WILL BE MET...AT
THIS POINT WARNING CRITERIA IS NOT FORECAST ALTHOUGH IT MAY BE
CLOSE IN NORTH CENTRAL IL SUNDAY NIGHT INTO EARLY MONDAY. SO HAVE
NOT OPTED ANY WATCH AT THIS TIME. IN ADDITION...WIND CHILL
ADVISORY CRITERIA MAY BE CLOSE AGAIN TUESDAY NIGHT INTO EARLY
WEDNESDAY.
NEXT WEEK...A NORTHWEST JET AROUND 150KT WILL RE-INTENSIFY THE
HUDSON BAY TROUGH WITH 500MB HEIGHTS AT ITS CENTER FORECAST TO DIP
TO AN EYE-OPENING LOW 481DM. THIS WILL ALLOW FOR ESTABLISHED
NORTHWEST FLOW OVER THE MIDWEST AND WITH THAT ONCE AGAIN COMES
SEVERAL SMALL MID-LEVEL PERTURBATIONS CAPABLE OF SNOW. AS THIS
PAST WEEK SHOWED...THESE ARE CHALLENGING TO FORECAST SPECIFICS
WELL IN ADVANCE. OVERALL...THE PATTERN WILL BE FAVORABLE FOR THESE
TO BRING MINOR ACCUMULATIONS OVER THE PATH THEY TAKE...JUST GIVEN
A DEEPER DENDRITIC GROWTH ZONE ABLE TO BE SATURATED WITH EACH
IMPULSE. MONDAY NIGHT AND AGAIN TUESDAY NIGHT AT THIS TIME ARE THE
AVERAGES IN GUIDANCE FOR POTENTIALLY LIGHT ACCUMULATING
SNOW...BUT AGAIN QUITE A BIT COULD CHANGE WITH THESE. FOR
TEMPERATURES...EACH IMPULSE LOOKS TO KEEP THE COLD AIR IN PLACE
WITH ONLY VERY MINIMAL WARM AIR ADVECTION IN ADVANCE OF ANY OF
THESE. HAVE UNDERCUT A MODEL MEAN SLIGHTLY OVER THE NORTHWEST
FORECAST AREA WHERE SNOW PACK STILL SHOULD HAVE GREATER INFLUENCE
TO KEEP TEMPS DOWN. ALL IN ALL THOUGH VERY LITTLE CHANGES TO
PREVIOUS FORECAST FOR NEXT WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
*ARRIVAL TIME OF ARCTIC FRONT LATE OVERNIGHT SUN.
*INCREASING CHANCE FOR -SN DURING PREDAWN SUN...BECOMING LIKELY BY
MID MORNING.
TRS/RATZER
//DISCUSSION...UPDATED 12Z...
NO PROBLEMS UNTIL LATE IN THE FORECAST PERIOD WHEN AND ARCTIC
FRONT SWEEPS ACROSS THE LOCAL AREA DURING LATE OVERNIGHT TONIGHT
TO EARLY SUN MORNING TIME FRAME.
MODELS TEND TO GRADUALLY VEER WINDS RATHER THAN DEPICT A WELL
DEFINED WIND SHIFT BUT USING SURFACE WIND STREAMLINES MODELS ARE
SIMILAR IN FROPA AROUND 11Z BUT DO NOT EXPECT WIND TO BECOME VERY
GUSTY OUT OF THE NW UNTIL LATER IN THE MORNING WHEN THE MID LEVEL
TROUGH PASSES BY.
OTHER PROBLEMS ARE TIMING THE ARRIVAL OF STRATOCUMULUS BEHIND THE
FRONT AS WELL AS WHEN -SN BECOMES LIKELY. MODEL AGAIN SIMILAR IN
LOWER LEVEL RH PROGS BRING STRATOCUMULUS SOON AFTER THE FRONT
PASSES...LOWERING BASES INTO MVFR DURING BY MID MORNING. BASED ON
MODEL QFP FIELDS NO PRECIP S OF THE WI BORDER BEFORE 12Z. WITH
BOTH THE 12Z AND 18Z PROGS VERY SIMILAR IN THE PLACEMENT OF
PRECIP. EXTRAPOLATION OF THE LEADING EDGE OF 0.01 BETWEEN 12Z AND
18Z BRINGS IN -SN AROUND MID MORNING.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
*HIGH ALL ELEMENTS BUT MEDIUM ON ARRIVAL TIME OF COLD
FRONT...MVFR AND -SN ARRIVE OVERNIGHT/EARLY SUN MORNING.
TRS/RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...MVFR CIGS...BECOMING VFR OVERNIGHT.
MONDAY...VFR...BECOMING MVFR MON NIGHT WITH A CHANCE OF SNOW.
TUESDAY...MVFR CIGS. CHANCE OF LIGHT SNOW.
WEDNESDAY...MVFR CIGS. CHANCE OF LIGHT SNOW.
THURSDAY...VFR.
FRIDAY...VFR. SLIGHT CHANCE OF SNOW SHOWERS.
TRS
&&
.MARINE...
441 AM CST
A STRONG SW FLOW WILL DEVELOP TODAY AS LOW PRESSURE MOVES SE FROM
ND TO WI. HOWEVER...WITH STRONG WARM AIR ADVECTION CONTINUING AND
THE WATER IN THE LOWER TO MID 30S F THE SURFACE WILL BE DECOUPLED
FROM THE STRONG FLOW JUST ABOVE THE BASE OF THE TEMPERATURE
INVERSION. NORTHWEST GALES OF 35 TO 40 KT WILL ARRIVE DURING THE
PREDAWN HOURS OF SUNDAY ON THE N END OF LAKE MICHIGAN...AND THE
S END BY MID MORNING SUNDAY AS THE LOW MOVES E ACROSS FAR N LAKE
MI INTO NORTHERN LOWER MI OVERNIGHT AND THE TRAILING COLD FRONT
SWEEPS SE ACROSS THE LAKE OVERNIGHT TONIGHT AND EARLY SUN MORNING.
ARCTIC AIR WILL OVERSPREAD THE UPPER GREAT LAKES BEHIND THE COLD
FRONT RESULTING IN A VERY UNSTABLE CONDITION DUE TO THE LARGE
CONTRAST BETWEEN WATER AND AIR TEMPERATURE. THIS WILL RESULT IN
EFFICIENT TRANSFER OF STRONG WINDS RIGHT DOWN TO THE LAKE
SURFACE. IN ADDITION...STRONG HIGH PRESSURE WILL BE BUILDING SE
FROM S SASKATCHEWAN ACROSS THE N AND CENTRAL PLAINS OVERNIGHT
TONIGHT AND SUN. WINDS WILL GRADUALLY DIMINISH SUN NIGHT AS THIS
HIGH MOVES TO THE UPPER AND MID MS VALLEY.
A GALE WARNING IS UP FOR ALL THE OPEN WATERS OF THE LAKE...STARTING
IN THE PREDAWN HOURS ON THE N...AND MID MORNING ON THE S. A GALE
WARNING IS ALSO IN EFFECT FOR THE NEARSHORE FROM GARY TO MI CITY .
A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED FROM WINTHROP HARBOR
TO GARY DURING SUN AND SUN NIGHT.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...4 AM
SUNDAY TO 6 PM SUNDAY.
GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ744-
LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-
LMZ878...9 AM SUNDAY TO 9 PM SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
937 AM CST Sat Dec 28 2013
.DISCUSSION...
ISSUED 936 AM CST Sat Dec 28 2013
Temperature trends remain the primary forecast concern for today.
Already have widespread upper 30s and lower 40s over the CWA, even
in the snow covered northwest. Most of the model guidance
continues to run too cool. Have favored the HRRR which looks good
in most areas, except it also is too cool where the snow is
currently in place. Morning cooperative weather observations, as
well as visible satellite imagery, show 1-2 inches still on the
ground early this morming across Knox, Stark and western
Marshall Counties. Should still get in the upper 40s there, but
50-55 will be common elsewhere this afternoon. Have sent updated
grids to reflect the latest trends, but the worded forecasts still
look good.
Geelhart
&&
.AVIATION...
ISSUED 545 AM CST Sat Dec 28 2013
VFR conditions will prevail in central and eastern Illinois today
and into much of the overnight hours. A southwest surface wind
will remain in the 10-15 knot range as the pressure gradient
changes little throughout the day. Initial information from this
morning`s KILX upper air sounding indicated marginal wind speeds
for low level wind shear. Will not mention in the TAFs at this
point since it is still below LLWS criteria, and little change is
anticipated this morning.
High and mid level clouds from the lower Mississippi River valley
will continue to spread northward. Cirrus ceilings will reach
central IL TAF sites early this evening, along with scattered mid
clouds from 10-15 kFT. A quickly approaching cold front from the
northwest will usher in much colder air and shift the wind to the
northwest just before daybreak Sunday in central IL, between 10-12Z.
MVFR ceilings are also likely at and just behind the cold front,
so will introduce these into the forecast from KBMI-KSPI and
points west.
Miller
&&
.PREV DISCUSSION...
ISSUED 330 AM CST Sat Dec 28 2013
SHORT TERM...Today through Monday
00Z short range models are in good agreement through Monday and
will use a blend. Polar vortex over northeast Canada through mid
week to have northern stream short waves passing through the
Midwest and Great Lakes region around Monday night into Tue night
and another one around Thu. Models differ with timing and
placement of these features and will use a blend of models and
previous forecast for this package.
Another mild day today expected across central and southeast IL
with some areas getting in the low to mid 50s. Then an arctic cold
front near the US/Canadian border to pass se through IL later
tonight into Sunday morning. Just a small chance of light
precipitation Sunday (mainly light snow or flurries). More
importantly, this front to usher in another arctic airmass Sunday
and Sunday night and will stick around through Thursday night.
Early morning surface map shows 1030 mb high pressure over the
southeast states while 1004 mb low pressure along the MT/ND and
Canadian border. SW winds over IL keeping milder temps in the mid
to upper 30s early this morning with nearly clear skies. 568 dm
500 mb low over west Texas has high/cirrus clouds spreading
northward into the mid MS valley including far southern IL and KY
early this morning. Some of these thin high clouds to spread into
central and especially southeast IL today with a fair amount of
sunshine still expected today. SW winds 10-15 mph and gusts 15-20
mph to boost highs in the low to mid 50s this afternoon, expected
upper 40s nw of the IL river where a light snow cover remains
especially over Knox and Stark counties.
Arctic cold front near the US/Canadian border to push se through
the IL river valley late tonight and have temps dropping into the
upper teens and lower 20s nw of the IL river by dawn while milder
low to mid 30s over eastern/se IL for lows tonight. Clouds to
increase during tonight with a fair amount of clouds Sunday as
arctic front pass se through eastern/se IL sunday morning. Not
much moisture to work with so think mainly small chance of very
light precipitation Sunday behind the front in from of light snow
or flurries, though light rain possible Sunday morning over se IL.
Highs Sunday in the morning range from the lower 20s nw of the IL
river to the upper 30s and lower 40s in southeast IL with falling
temps through the day behind the arctic front.
Very cold air advects into IL Sunday night into Monday with wind
chills likely getting to 15 to 20 below zero north of I-72
overnight Sunday night into Monday morning and will likely need a
wind chill advisory as event gets closer. Lows Sunday night to be
in the single digits below from I-55 nw with highs Monday from 8-14
north of I-72.
LONG TERM...Monday night through Friday
Very cold conditions expected to continue Monday night through Thu
night with polar vortex in northeast Canada and strong upper level
trof over the region and reinforced on Thursday. A northern stream
short wave approaches northern counties during Monday night with
slight chance of light snow or flurries and gets further into
central IL Tue and Tuesday night before exiting on Wed. Not
expecting much accumulations of snow at this point in dry airmass.
Could be another chance of flurries on Thursday with strong upper
level trof and possible short wave moving thru region. Large upper
level trof shifts east of IL Fri/Sat with temps moderating closer
to normal with dry conditions expected.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
922 AM EST SAT DEC 28 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 223 AM EST SAT DEC 28 2013
SOUTHWEST WINDS ON THE BACK SIDE OF HIGH PRESSURE WILL ALLOW FOR
ABOVE NORMAL TEMPERATURES TODAY THROUGH MIDDAY SUNDAY. THEN...AN
ARCTIC FRONT WILL SLIDE SOUTHEAST ACROSS CENTRAL INDIANA ON SUNDAY
BRINGING A SMALL CHANCE OF RAIN OR SNOW IN BUT MORE IMPORTANTLY MUCH
COLDER TEMPERATURES. SMALL SNOW CHANCES WILL RETURN MIDWEEK AS
DISTURBANCES MOVE THROUGH IN FAST NORTHWEST FLOW ALOFT.
OTHERWISE...BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH ALL OF
NEXT WEEK.
&&
.NEAR TERM /TODAY/...
ISSUED AT 223 AM EST SAT DEC 28 2013
MAIN CHALLENGE TO THE NEAR TERM WILL BE TEMPERATURES AS MODELS AND
MOS HAVE BEEN UNDERESTIMATING THE LATEST WARMUP.
MODELS IN GOOD AGREEMENT THAT SURFACE HIGH PRESSURE ACROSS THE
TENNESSEE VALLEY WILL SLIDE EAST TO THE ATLANTIC OCEAN LATE TODAY
WITH SOUTHWEST LOW LEVEL FLOW CONTINUING ACROSS THE AREA. IN
ADDITION...UPPER LOW WILL MOVE NORTHEAST ACROSS NORTHERN TEXAS AND
POLAR FRONT WILL DROP SOUTHEAST ACROSS THE NORTHERN AND CENTRAL
PLAINS AHEAD OF A NORTHERN STREAM UPPER TROUGH. THE DAY SHOULD START
OFF SUNNY WITH MODEL TIME SECTIONS SHOWING A DRY COLUMN.
HOWEVER...HIGH CLOUDS WILL BE INCREASING FROM SOUTH TO NORTH AHEAD
OF THE SOUTHERN SYSTEM. HIGH RESOLUTION NAM12 AND RAP SOUNDINGS WERE
INDICATING INVERSION SHOULD BE IN PLACE AROUND 950 MILLIBARS...SO
WOULD NOT RULE OUT MIXING OF 3K FEET WINDS TO THE SURFACE WITH SOME
GUSTS TO NEAR 20 KNOTS. EITHER WAY...SHOULD SEE TEMPERATURES WARM TO
THE 50S TODAY...A FEW DEGREES WARMER THAN 00Z MOS.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 223 AM EST SAT DEC 28 2013
MAIN FOCUS TO THE SHORT TERM WILL BE ON TEMPERATURES...ESPECIALLY
SUNDAY AS AN ARCTIC FRONT IS POISED TO DROP SOUTHEAST ACROSS CENTRAL
INDIANA. POPS AND PRECIPITATION TYPE WILL ALSO BE CHALLENGE ON
SUNDAY WITH THE FRONT MOVING THROUGH ALONG WITH A TRAILING UPPER
TROUGH. THE SOUTHERN TROUGH IS ALSO EXPECTED TO BRING RAIN CLOSE
TO...IF NOT ACROSS OUR FAR SOUTH OVERNIGHT SATURDAY NIGHT DEPENDING
ON MODEL OF CHOICE.
00Z GFS AND NAM CLOSE TO THE 12Z ECMWF REGARD HANDLING OF WEAKENING
SOUTHERN PLAINS UPPER LOW AND ALSO WITH THE ARCTIC FRONT.
HOWEVER...MODELS...ESPECIALLY THE GFS HAVE BEEN TRENDING FURTHER
NORTH WITH QPF WITH THE SOUTHERN SYSTEM SATURDAY NIGHT. A BLEND
WOULD WARRANT AT LEAST SMALL POPS AFTER 06Z SUNDAY FOR OUR SOUTHERN
TIER OR TWO. OTHERWISE...SHOULD SEE SKY COVER INCREASE FROM
SOUTH TO NORTH TONIGHT.
MODELS ON SUNDAY SUGGEST THE ARCTIC FRONT WILL BE ACROSS OUR
NORTHWEST COUNTIES SHORTLY AFTER 12Z AND AT OUR EASTERN BORDER
AROUND 18Z. SO...TRIED TO TIME HOURLY TEMPERATURES TO DROP FOLLOWING
THE FRONTAL PASSAGE AND THUS WARMEST TEMPERATURES WILL BE ACROSS THE
EASTERN COUNTIES AND COLDEST NORTHWEST PER 00Z ALLBLEND. WITH DEEPER
SOUTHERN SYSTEM MOISTURE PEELING OF TO THE NORTHEAST AND LITTLE
MOISTURE WITH ARCTIC SYSTEM...KEPT POPS LOW ON SUNDAY. REGARDING
PRECIPITATION TYPE...TRIED TO TIME THE MIX AND CHANGEOVER FROM SNOW
TO RAIN...FOLLOWING CLOSELY BUFKIT BLEND OF CANADIAN PARTIAL
THICKNESSES. THIS WOULD SUGGEST A MIX IN THE NORTHWEST SHORTLY
AFTER 12Z SUNDAY CHANGING TO ALL SNOW DURING THE AFTERNOON. THE
SOUTHEAST SHOULD START OFF AS RAIN AT 12Z AND MIX EARLY AFTERNOON
WITH ALL SNOW LATE AFTERNOON.
WITH THE SOUTHERN SYSTEM WELL NORTHEAST OF THE AREA AND THE NORTHERN
STREAM TROUGH MOISTURE STARVED...WILL NOT MENTION AND POPS SUNDAY
NIGHT.
MONDAY AND MONDAY NIGHT CONTINUE TO LOOK DRY WITH WEAK LOW PRESSURE
SYSTEM JUST TO OUR WEST MONDAY NIGHT MOISTURE STARVED.
00Z ALLBLEND LOOKS LIKE IT IS IN THE BALLPARK FOR TEMPERATURES FOR
THE MOST PART BY SUNDAY NIGHT WITH A FEW TWEAKS NEEDED HERE OR
THERE.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
ISSUED AT 230 AM EST SAT DEC 28 2013
MODELS CONTINUE TO ADVERTISE BROAD CYCLONIC FLOW ACROSS THE EASTERN
PORTION OF THE COUNTRY THROUGH THE LONG TERM PERIOD. ALTHOUGH THIS
MAY LEND ITSELF TO A WAVE OR TWO PROVIDING SOME LIGHT SNOW CHANCES
ACROSS THE AREA...TIMING THESE WAVES...ESPECIALLY THIS FAR OUT...IS
A LOSING PROPOSITION. THUS...FEEL IMPROVEMENTS ARE UNLIKELY TO BE
MADE OVER ALLBLEND INITIALIZATION ASIDE FROM MINOR TWEAKS. WILL
CARRY SLIGHT CHANCE OF SNOW SHOWERS TUESDAY NIGHT INTO WEDNESDAY
NIGHT WITH A POSSIBLE WAVE MOVING THROUGH THE FLOW.
DIFFERENCES ARE LESSENING BETWEEN THE GFS AND EURO...HOWEVER THERE
IS STILL SOME DISCREPANCY ESPECIALLY LATE IN THE PERIOD REGARDING
INTRUSION OF COLD AIR INTO THE LOWER 48 AND RESULTANT TEMPS.
AGAIN...FEEL IMPROVEMENT OVER MODEL BLEND ARE UNLIKELY AND WILL MAKE
FEW CHANGES HERE. WITH BROAD CYCLONIC FLOW...TEMPS SHOULD LARGELY BE
BELOW NORMAL UNTIL PERHAPS LATE IN THE PERIOD DEPENDING ON WHICH
SOLUTION VERIFIES.
&&
.AVIATION /DISCUSSION FOR THE 281500Z KIND TAF UPDATE/...
ISSUED AT 922 AM EST SAT DEC 28 2013
NO SIGNIFICANT CHANGES MADE TO THE FORECAST AT THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.
VFR THOUGH THE PERIOD.
HIGH CLOUDS WILL CONTINUE ACROSS INDIANA THROUGH THE PERIOD...WITH A
GRADUAL LOWERING AND INCREASE OF MID AND HIGH CLOUDS IN THE LATTER
PORTION OF THE PERIOD.
NO VISIBILITY ISSUES EXPECTED THROUGH THE PERIOD. WINDS WILL BE 10KT
OR LESS THROUGHOUT...GENERALLY SOUTH THROUGH SOUTHWEST.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK
SHORT TERM...MK
LONG TERM...NIELD
AVIATION...NIELD/JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
602 AM EST SAT DEC 28 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 223 AM EST SAT DEC 28 2013
SOUTHWEST WINDS ON THE BACK SIDE OF HIGH PRESSURE WILL ALLOW FOR
ABOVE NORMAL TEMPERATURES TODAY THROUGH MIDDAY SUNDAY. THEN...AN
ARCTIC FRONT WILL SLIDE SOUTHEAST ACROSS CENTRAL INDIANA ON SUNDAY
BRINGING A SMALL CHANCE OF RAIN OR SNOW IN BUT MORE IMPORTANTLY MUCH
COLDER TEMPERATURES. SMALL SNOW CHANCES WILL RETURN MIDWEEK AS
DISTURBANCES MOVE THROUGH IN FAST NORTHWEST FLOW ALOFT.
OTHERWISE...BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH ALL OF
NEXT WEEK.
&&
.NEAR TERM /TODAY/...
ISSUED AT 223 AM EST SAT DEC 28 2013
MAIN CHALLENGE TO THE NEAR TERM WILL BE TEMPERATURES AS MODELS AND
MOS HAVE BEEN UNDERESTIMATING THE LATEST WARMUP.
MODELS IN GOOD AGREEMENT THAT SURFACE HIGH PRESSURE ACROSS THE
TENNESSEE VALLEY WILL SLIDE EAST TO THE ATLANTIC OCEAN LATE TODAY
WITH SOUTHWEST LOW LEVEL FLOW CONTINUING ACROSS THE AREA. IN
ADDITION...UPPER LOW WILL MOVE NORTHEAST ACROSS NORTHERN TEXAS AND
POLAR FRONT WILL DROP SOUTHEAST ACROSS THE NORTHERN AND CENTRAL
PLAINS AHEAD OF A NORTHERN STREAM UPPER TROUGH. THE DAY SHOULD START
OFF SUNNY WITH MODEL TIME SECTIONS SHOWING A DRY COLUMN.
HOWEVER...HIGH CLOUDS WILL BE INCREASING FROM SOUTH TO NORTH AHEAD
OF THE SOUTHERN SYSTEM. HIGH RESOLUTION NAM12 AND RAP SOUNDINGS WERE
INDICATING INVERSION SHOULD BE IN PLACE AROUND 950 MILLIBARS...SO
WOULD NOT RULE OUT MIXING OF 3K FEET WINDS TO THE SURFACE WITH SOME
GUSTS TO NEAR 20 KNOTS. EITHER WAY...SHOULD SEE TEMPERATURES WARM TO
THE 50S TODAY...A FEW DEGREES WARMER THAN 00Z MOS.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 223 AM EST SAT DEC 28 2013
MAIN FOCUS TO THE SHORT TERM WILL BE ON TEMPERATURES...ESPECIALLY
SUNDAY AS AN ARCTIC FRONT IS POISED TO DROP SOUTHEAST ACROSS CENTRAL
INDIANA. POPS AND PRECIPITATION TYPE WILL ALSO BE CHALLENGE ON
SUNDAY WITH THE FRONT MOVING THROUGH ALONG WITH A TRAILING UPPER
TROUGH. THE SOUTHERN TROUGH IS ALSO EXPECTED TO BRING RAIN CLOSE
TO...IF NOT ACROSS OUR FAR SOUTH OVERNIGHT SATURDAY NIGHT DEPENDING
ON MODEL OF CHOICE.
00Z GFS AND NAM CLOSE TO THE 12Z ECMWF REGARD HANDLING OF WEAKENING
SOUTHERN PLAINS UPPER LOW AND ALSO WITH THE ARCTIC FRONT.
HOWEVER...MODELS...ESPECIALLY THE GFS HAVE BEEN TRENDING FURTHER
NORTH WITH QPF WITH THE SOUTHERN SYSTEM SATURDAY NIGHT. A BLEND
WOULD WARRANT AT LEAST SMALL POPS AFTER 06Z SUNDAY FOR OUR SOUTHERN
TIER OR TWO. OTHERWISE...SHOULD SEE SKY COVER INCREASE FROM
SOUTH TO NORTH TONIGHT.
MODELS ON SUNDAY SUGGEST THE ARCTIC FRONT WILL BE ACROSS OUR
NORTHWEST COUNTIES SHORTLY AFTER 12Z AND AT OUR EASTERN BORDER
AROUND 18Z. SO...TRIED TO TIME HOURLY TEMPERATURES TO DROP FOLLOWING
THE FRONTAL PASSAGE AND THUS WARMEST TEMPERATURES WILL BE ACROSS THE
EASTERN COUNTIES AND COLDEST NORTHWEST PER 00Z ALLBLEND. WITH DEEPER
SOUTHERN SYSTEM MOISTURE PEELING OF TO THE NORTHEAST AND LITTLE
MOISTURE WITH ARCTIC SYSTEM...KEPT POPS LOW ON SUNDAY. REGARDING
PRECIPITATION TYPE...TRIED TO TIME THE MIX AND CHANGEOVER FROM SNOW
TO RAIN...FOLLOWING CLOSELY BUFKIT BLEND OF CANADIAN PARTIAL
THICKNESSES. THIS WOULD SUGGEST A MIX IN THE NORTHWEST SHORTLY
AFTER 12Z SUNDAY CHANGING TO ALL SNOW DURING THE AFTERNOON. THE
SOUTHEAST SHOULD START OFF AS RAIN AT 12Z AND MIX EARLY AFTERNOON
WITH ALL SNOW LATE AFTERNOON.
WITH THE SOUTHERN SYSTEM WELL NORTHEAST OF THE AREA AND THE NORTHERN
STREAM TROUGH MOISTURE STARVED...WILL NOT MENTION AND POPS SUNDAY
NIGHT.
MONDAY AND MONDAY NIGHT CONTINUE TO LOOK DRY WITH WEAK LOW PRESSURE
SYSTEM JUST TO OUR WEST MONDAY NIGHT MOISTURE STARVED.
00Z ALLBLEND LOOKS LIKE IT IS IN THE BALLPARK FOR TEMPERATURES FOR
THE MOST PART BY SUNDAY NIGHT WITH A FEW TWEAKS NEEDED HERE OR
THERE.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
ISSUED AT 230 AM EST SAT DEC 28 2013
MODELS CONTINUE TO ADVERTISE BROAD CYCLONIC FLOW ACROSS THE EASTERN
PORTION OF THE COUNTRY THROUGH THE LONG TERM PERIOD. ALTHOUGH THIS
MAY LEND ITSELF TO A WAVE OR TWO PROVIDING SOME LIGHT SNOW CHANCES
ACROSS THE AREA...TIMING THESE WAVES...ESPECIALLY THIS FAR OUT...IS
A LOSING PROPOSITION. THUS...FEEL IMPROVEMENTS ARE UNLIKELY TO BE
MADE OVER ALLBLEND INITIALIZATION ASIDE FROM MINOR TWEAKS. WILL
CARRY SLIGHT CHANCE OF SNOW SHOWERS TUESDAY NIGHT INTO WEDNESDAY
NIGHT WITH A POSSIBLE WAVE MOVING THROUGH THE FLOW.
DIFFERENCES ARE LESSENING BETWEEN THE GFS AND EURO...HOWEVER THERE
IS STILL SOME DISCREPANCY ESPECIALLY LATE IN THE PERIOD REGARDING
INTRUSION OF COLD AIR INTO THE LOWER 48 AND RESULTANT TEMPS.
AGAIN...FEEL IMPROVEMENT OVER MODEL BLEND ARE UNLIKELY AND WILL MAKE
FEW CHANGES HERE. WITH BROAD CYCLONIC FLOW...TEMPS SHOULD LARGELY BE
BELOW NORMAL UNTIL PERHAPS LATE IN THE PERIOD DEPENDING ON WHICH
SOLUTION VERIFIES.
&&
.AVIATION /DISCUSSION FOR THE 28/12Z TAFS/...
ISSUED AT 602 AM EST SAT DEC 28 2013
VFR THOUGH THE PERIOD.
HIGH CLOUDS WILL CONTINUE ACROSS INDIANA THROUGH THE PERIOD...WITH A
GRADUAL LOWERING AND INCREASE OF MID AND HIGH CLOUDS IN THE LATTER
PORTION OF THE PERIOD.
NO VISIBILITY ISSUES EXPECTED THROUGH THE PERIOD. WINDS WILL BE 10KT
OR LESS THROUGHOUT...GENERALLY SOUTH THROUGH SOUTHWEST.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK
SHORT TERM...MK
LONG TERM...NIELD
AVIATION...NIELD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
230 AM EST SAT DEC 28 2013
.UPDATE...
THE LONG TERM AND AVIATION SECTIONS HAVE BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 223 AM EST SAT DEC 28 2013
SOUTHWEST WINDS ON THE BACK SIDE OF HIGH PRESSURE WILL ALLOW FOR
ABOVE NORMAL TEMPERATURES TODAY THROUGH MIDDAY SUNDAY. THEN...AN
ARCTIC FRONT WILL SLIDE SOUTHEAST ACROSS CENTRAL INDIANA ON SUNDAY
BRINGING A SMALL CHANCE OF RAIN OR SNOW IN BUT MORE IMPORTANTLY MUCH
COLDER TEMPERATURES. SMALL SNOW CHANCES WILL RETURN MIDWEEK AS
DISTURBANCES MOVE THROUGH IN FAST NORTHWEST FLOW ALOFT.
OTHERWISE...BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH ALL OF
NEXT WEEK.
&&
.NEAR TERM /TODAY/...
ISSUED AT 223 AM EST SAT DEC 28 2013
MAIN CHALLENGE TO THE NEAR TERM WILL BE TEMPERATURES AS MODELS AND
MOS HAVE BEEN UNDERESTIMATING THE LATEST WARMUP.
MODELS IN GOOD AGREEMENT THAT SURFACE HIGH PRESSURE ACROSS THE
TENNESSEE VALLEY WILL SLIDE EAST TO THE ATLANTIC OCEAN LATE TODAY
WITH SOUTHWEST LOW LEVEL FLOW CONTINUING ACROSS THE AREA. IN
ADDITION...UPPER LOW WILL MOVE NORTHEAST ACROSS NORTHERN TEXAS AND
POLAR FRONT WILL DROP SOUTHEAST ACROSS THE NORTHERN AND CENTRAL
PLAINS AHEAD OF A NORTHERN STREAM UPPER TROUGH. THE DAY SHOULD START
OFF SUNNY WITH MODEL TIME SECTIONS SHOWING A DRY COLUMN.
HOWEVER...HIGH CLOUDS WILL BE INCREASING FROM SOUTH TO NORTH AHEAD
OF THE SOUTHERN SYSTEM. HIGH RESOLUTION NAM12 AND RAP SOUNDINGS WERE
INDICATING INVERSION SHOULD BE IN PLACE AROUND 950 MILLIBARS...SO
WOULD NOT RULE OUT MIXING OF 3K FEET WINDS TO THE SURFACE WITH SOME
GUSTS TO NEAR 20 KNOTS. EITHER WAY...SHOULD SEE TEMPERATURES WARM TO
THE 50S TODAY...A FEW DEGREES WARMER THAN 00Z MOS.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 223 AM EST SAT DEC 28 2013
MAIN FOCUS TO THE SHORT TERM WILL BE ON TEMPERATURES...ESPECIALLY
SUNDAY AS AN ARCTIC FRONT IS POISED TO DROP SOUTHEAST ACROSS CENTRAL
INDIANA. POPS AND PRECIPITATION TYPE WILL ALSO BE CHALLENGE ON
SUNDAY WITH THE FRONT MOVING THROUGH ALONG WITH A TRAILING UPPER
TROUGH. THE SOUTHERN TROUGH IS ALSO EXPECTED TO BRING RAIN CLOSE
TO...IF NOT ACROSS OUR FAR SOUTH OVERNIGHT SATURDAY NIGHT DEPENDING
ON MODEL OF CHOICE.
00Z GFS AND NAM CLOSE TO THE 12Z ECMWF REGARD HANDLING OF WEAKENING
SOUTHERN PLAINS UPPER LOW AND ALSO WITH THE ARCTIC FRONT.
HOWEVER...MODELS...ESPECIALLY THE GFS HAVE BEEN TRENDING FURTHER
NORTH WITH QPF WITH THE SOUTHERN SYSTEM SATURDAY NIGHT. A BLEND
WOULD WARRANT AT LEAST SMALL POPS AFTER 06Z SUNDAY FOR OUR SOUTHERN
TIER OR TWO. OTHERWISE...SHOULD SEE SKY COVER INCREASE FROM
SOUTH TO NORTH TONIGHT.
MODELS ON SUNDAY SUGGEST THE ARCTIC FRONT WILL BE ACROSS OUR
NORTHWEST COUNTIES SHORTLY AFTER 12Z AND AT OUR EASTERN BORDER
AROUND 18Z. SO...TRIED TO TIME HOURLY TEMPERATURES TO DROP FOLLOWING
THE FRONTAL PASSAGE AND THUS WARMEST TEMPERATURES WILL BE ACROSS THE
EASTERN COUNTIES AND COLDEST NORTHWEST PER 00Z ALLBLEND. WITH DEEPER
SOUTHERN SYSTEM MOISTURE PEELING OF TO THE NORTHEAST AND LITTLE
MOISTURE WITH ARCTIC SYSTEM...KEPT POPS LOW ON SUNDAY. REGARDING
PRECIPITATION TYPE...TRIED TO TIME THE MIX AND CHANGEOVER FROM SNOW
TO RAIN...FOLLOWING CLOSELY BUFKIT BLEND OF CANADIAN PARTIAL
THICKNESSES. THIS WOULD SUGGEST A MIX IN THE NORTHWEST SHORTLY
AFTER 12Z SUNDAY CHANGING TO ALL SNOW DURING THE AFTERNOON. THE
SOUTHEAST SHOULD START OFF AS RAIN AT 12Z AND MIX EARLY AFTERNOON
WITH ALL SNOW LATE AFTERNOON.
WITH THE SOUTHERN SYSTEM WELL NORTHEAST OF THE AREA AND THE NORTHERN
STREAM TROUGH MOISTURE STARVED...WILL NOT MENTION AND POPS SUNDAY
NIGHT.
MONDAY AND MONDAY NIGHT CONTINUE TO LOOK DRY WITH WEAK LOW PRESSURE
SYSTEM JUST TO OUR WEST MONDAY NIGHT MOISTURE STARVED.
00Z ALLBLEND LOOKS LIKE IT IS IN THE BALLPARK FOR TEMPERATURES FOR
THE MOST PART BY SUNDAY NIGHT WITH A FEW TWEAKS NEEDED HERE OR
THERE.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
ISSUED AT 230 AM EST SAT DEC 28 2013
MODELS CONTINUE TO ADVERTISE BROAD CYCLONIC FLOW ACROSS THE EASTERN
PORTION OF THE COUNTRY THROUGH THE LONG TERM PERIOD. ALTHOUGH THIS
MAY LEND ITSELF TO A WAVE OR TWO PROVIDING SOME LIGHT SNOW CHANCES
ACROSS THE AREA...TIMING THESE WAVES...ESPECIALLY THIS FAR OUT...IS
A LOSING PROPOSITION. THUS...FEEL IMPROVEMENTS ARE UNLIKELY TO BE
MADE OVER ALLBLEND INITIALIZATION ASIDE FROM MINOR TWEAKS. WILL
CARRY SLIGHT CHANCE OF SNOW SHOWERS TUESDAY NIGHT INTO WEDNESDAY
NIGHT WITH A POSSIBLE WAVE MOVING THROUGH THE FLOW.
DIFFERENCES ARE LESSENING BETWEEN THE GFS AND EURO...HOWEVER THERE
IS STILL SOME DISCREPANCY ESPECIALLY LATE IN THE PERIOD REGARDING
INTRUSION OF COLD AIR INTO THE LOWER 48 AND RESULTANT TEMPS.
AGAIN...FEEL IMPROVEMENT OVER MODEL BLEND ARE UNLIKELY AND WILL MAKE
FEW CHANGES HERE. WITH BROAD CYCLONIC FLOW...TEMPS SHOULD LARGELY BE
BELOW NORMAL UNTIL PERHAPS LATE IN THE PERIOD DEPENDING ON WHICH
SOLUTION VERIFIES.
&&
.AVIATION /DISCUSSION FOR THE 28/09Z TAF UPDATE/...
ISSUED AT 230 AM EST SAT DEC 28 2013
NO CHANGES NECESSARY. PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 1115 PM EST FRI DEC 27 2013
VFR THOUGH THE PERIOD.
HIGH CLOUDS WILL CONTINUE ACROSS INDIANA THROUGH THE PERIOD...WITH A
GRADUAL LOWERING AND INCREASE OF MID AND HIGH CLOUDS IN THE LATTER
HALF OF THE TAF PERIOD.
WINDS 1000FT ABOVE GROUND LEVEL AND ABOVE WILL BE AROUND 30-40KT
TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK
SHORT TERM...MK
LONG TERM...NIELD
AVIATION...50/NIELD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION...CORRECTED
NWS INDIANAPOLIS IN
228 PM EST FRI DEC 27 2013
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED
BELOW.
&&
.SYNOPSIS...
ISSUED AT 228 AM EST SAT DEC 28 2013
SOUTHWEST WINDS ON THE BACK SIDE OF HIGH PRESSURE WILL ALLOW FOR
ABOVE NORMAL TEMPERATURES TODAY THROUGH MIDDAY SUNDAY. THEN...AN
ARCTIC FRONT WILL SLIDE SOUTHEAST ACROSS CENTRAL INDIANA ON SUNDAY
BRINGING A SMALL CHANCE OF RAIN OR SNOW IN BUT MORE IMPORTANTLY MUCH
COLDER TEMPERATURES. SMALL SNOW CHANCES WILL RETURN MIDWEEK AS
DISTURBANCES MOVE THROUGH IN FAST NORTHWEST FLOW ALOFT.
OTHERWISE...BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH ALL OF
NEXT WEEK.
&&
.NEAR TERM /TODAY/...
ISSUED AT 228 AM EST SAT DEC 28 2013
MAIN CHALLENGE TO THE NEAR TERM WILL BE TEMPERATURES AS MODELS AND
MOS HAVE BEEN UNDERESTIMATING THE LATEST WARMUP.
MODELS IN GOOD AGREEMENT THAT SURFACE HIGH PRESSURE ACROSS THE
TENNESSEE VALLEY WILL SLIDE EAST TO THE ATLANTIC OCEAN LATE TODAY
WITH SOUTHWEST LOW LEVEL FLOW CONTINUING ACROSS THE AREA. IN
ADDITION...UPPER LOW WILL MOVE NORTHEAST ACROSS NORTHERN TEXAS AND
POLAR FRONT WILL DROP SOUTHEAST ACROSS THE NORTHERN AND CENTRAL
PLAINS AHEAD OF A NORTHERN STREAM UPPER TROUGH. THE DAY SHOULD START
OFF SUNNY WITH MODEL TIME SECTIONS SHOWING A DRY COLUMN.
HOWEVER...HIGH CLOUDS WILL BE INCREASING FROM SOUTH TO NORTH AHEAD
OF THE SOUTHERN SYSTEM. HIGH RESOLUTION NAM12 AND RAP SOUNDINGS WERE
INDICATING INVERSION SHOULD BE IN PLACE BELOW 950 MILLIBARS...BUT
WOULD NOT RULE OUT MIXING OF SUB 1K FEET WINDS TO THE SURFACE WITH
SOME GUSTS TO NEAR 20 KNOTS. EITHER WAY...SHOULD SEE TEMPERATURES
WARM TO THE 50S TODAY...A FEW DEGREES WARMER THAN 00Z MOS.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 228 AM EST SAT DEC 28 2013
MAIN FOCUS TO THE SHORT TERM WILL BE ON TEMPERATURES...ESPECIALLY
SUNDAY AS AN ARCTIC FRONT IS POISED TO DROP SOUTHEAST ACROSS CENTRAL
INDIANA. POPS AND PRECIPITATION TYPE WILL ALSO BE CHALLENGE ON
SUNDAY WITH THE FRONT MOVING THROUGH ALONG WITH A TRAILING UPPER
TROUGH. THE SOUTHERN TROUGH IS ALSO EXPECTED TO BRING RAIN CLOSE
TO...IF NOT ACROSS OUR FAR SOUTH OVERNIGHT SATURDAY NIGHT DEPENDING
ON MODEL OF CHOICE.
00Z GFS AND NAM CLOSE TO THE 12Z ECMWF REGARD HANDLING OF WEAKENING
SOUTHERN PLAINS UPPER LOW AND ALSO WITH THE ARCTIC FRONT.
HOWEVER...MODELS...ESPECIALLY THE GFS HAVE BEEN TRENDING FURTHER
NORTH WITH QPF WITH THE SOUTHERN SYSTEM SATURDAY NIGHT. A BLEND
WOULD WARRANT AT LEAST SMALL POPS AFTER 06Z SUNDAY FOR OUR SOUTHERN
TIER OR TWO. OTHERWISE...SHOULD SEE SKY COVER INCREASE FROM
SOUTH TO NORTH TONIGHT.
MODELS ON SUNDAY SUGGEST THE ARCTIC FRONT WILL BE ACROSS OUR
NORTHWEST COUNTIES SHORTLY AFTER 12Z AND AT OUR EASTERN BORDER
AROUND 18Z. SO...TRIED TO TIME HOURLY TEMPERATURES TO DROP FOLLOWING
THE FRONTAL PASSAGE AND THUS WARMEST TEMPERATURES WILL BE ACROSS THE
EASTERN COUNTIES AND COLDEST NORTHWEST PER 00Z ALLBLEND. WITH DEEPER
SOUTHERN SYSTEM MOISTURE PEELING OF TO THE NORTHEAST AND LITTLE
MOISTURE WITH ARCTIC SYSTEM...KEPT POPS LOW ON SUNDAY. REGARDING
PRECIPITATION TYPE...TRIED TO TIME THE MIX AND CHANGEOVER FROM SNOW
TO RAIN...FOLLOWING CLOSELY BUFKIT BLEND OF CANADIAN PARTIAL
THICKNESSES. THIS WOULD SUGGEST A MIX IN THE NORTHWEST SHORTLY
AFTER 12Z SUNDAY CHANGING TO ALL SNOW DURING THE AFTERNOON. THE
SOUTHEAST SHOULD START OFF AS RAIN AT 12Z AND MIX EARLY AFTERNOON
WITH ALL SNOW LATE AFTERNOON.
WITH THE SOUTHERN SYSTEM WELL NORTHEAST OF THE AREA AND THE NORTHERN
STREAM TROUGH MOISTURE STARVED...WILL NOT MENTION AND POPS SUNDAY
NIGHT.
MONDAY AND MONDAY NIGHT CONTINUE TO LOOK DRY WITH WEAK LOW PRESSURE
SYSTEM JUST TO OUR WEST MONDAY NIGHT MOISTURE STARVED.
00Z ALLBLEND LOOKS LIKE IT IS IN THE BALLPARK FOR TEMPERATURES FOR
THE MOST PART BY SUNDAY NIGHT WITH A FEW TWEAKS NEEDED HERE OR
THERE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 216 PM EST FRI DEC 27 2013
ENSEMBLE DATA SUGGEST MEAN UPPER TROUGHING WILL CONTINUE ACROSS THE
EASTERN PARTS OF THE COUNTRY THROUGH LATE NEXT WEEK. APPEARS THE
MAIN PRECIPITATION THREAT DURING THIS PERIOD WILL BE AROUND NEXT
WEDNESDAY INTO THURSDAY AS ENSEMBLES INDICATE A DISTURBANCE WILL
DROP SOUTHEAST FROM THE NORTHERN PLAINS INTO THE LOCAL AREA BY THAT
TIME. THERE IS A QUITE A SPREAD AMONG THE ENSEMBLES AS TO THE
INTENSITY/TRACK OF THIS SYSTEM. MOST OF THE ENSEMBLES ARE
PROGRESSIVE WITH THIS DISTURBANCE...BUT THERE ARE A FEW THAT SUGGEST
SYSTEM MAY BE STRONG ENOUGH TO CUTOFF OVER THE OHIO VALLEY BY LATE
NEXT WEEK. FOR NOW...WILL GO WITH THE WEAKER MORE PROGRESSIVE
SOLUTIONS AND BRING CHANCE POPS FOR SNOW TO THE AREA WEDNESDAY NIGHT
INTO THURSDAY. POTENTIAL FOR LIGHT ACCUMULATIONS EXIST WITH THIS
SYSTEM.
&&
.AVIATION /DISCUSSION FOR 280600Z TAF ISSUANCE/...
ISSUED AT 1115 PM EST FRI DEC 27 2013
VFR THOUGH THE PERIOD.
HIGH CLOUDS WILL CONTINUE ACROSS INDIANA THROUGH THE PERIOD...WITH A
GRADUAL LOWERING AND INCREASE OF MID AND HIGH CLOUDS IN THE LATTER
HALF OF THE TAF PERIOD.
WINDS 1000FT ABOVE GROUND LEVEL AND ABOVE WILL BE AROUND 30-40KT
TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK
SHORT TERM...MK
LONG TERM....JAS
AVIATION...50
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
223 PM EST FRI DEC 27 2013
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED
BELOW.
&&
.SYNOPSIS...
ISSUED AT 223 AM EST SAT DEC 28 2013
SOUTHWEST WINDS ON THE BACK SIDE OF HIGH PRESSURE WILL ALLOW FOR
ABOVE NORMAL TEMPERATURES TODAY THROUGH MIDDAY SUNDAY. THEN...AN
ARCTIC FRONT WILL SLIDE SOUTHEAST ACROSS CENTRAL INDIANA ON SUNDAY
BRINGING A SMALL CHANCE OF RAIN OR SNOW IN BUT MORE IMPORTANTLY MUCH
COLDER TEMPERATURES. SMALL SNOW CHANCES WILL RETURN MIDWEEK AS
DISTURBANCES MOVE THROUGH IN FAST NORTHWEST FLOW ALOFT.
OTHERWISE...BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH ALL OF
NEXT WEEK.
&&
.NEAR TERM /TODAY/...
ISSUED AT 223 AM EST SAT DEC 28 2013
MAIN CHALLENGE TO THE NEAR TERM WILL BE TEMPERATURES AS MODELS AND
MOS HAVE BEEN UNDERESTIMATING THE LATEST WARMUP.
MODELS IN GOOD AGREEMENT THAT SURFACE HIGH PRESSURE ACROSS THE
TENNESSEE VALLEY WILL SLIDE EAST TO THE ATLANTIC OCEAN LATE TODAY
WITH SOUTHWEST LOW LEVEL FLOW CONTINUING ACROSS THE AREA. IN
ADDITION...UPPER LOW WILL MOVE NORTHEAST ACROSS NORTHERN TEXAS AND
POLAR FRONT WILL DROP SOUTHEAST ACROSS THE NORTHERN AND CENTRAL
PLAINS AHEAD OF A NORTHERN STREAM UPPER TROUGH. THE DAY SHOULD START
OFF SUNNY WITH MODEL TIME SECTIONS SHOWING A DRY COLUMN.
HOWEVER...HIGH CLOUDS WILL BE INCREASING FROM SOUTH TO NORTH AHEAD
OF THE SOUTHERN SYSTEM. HIGH RESOLUTION NAM12 AND RAP SOUNDINGS WERE
INDICATING INVERSION SHOULD BE IN PLACE AROUND 950 MILLIBARS...SO
WOULD NOT RULE OUT MIXING OF 3K FEET WINDS TO THE SURFACE WITH SOME
GUSTS TO NEAR 20 KNOTS. EITHER WAY...SHOULD SEE TEMPERATURES WARM TO
THE 50S TODAY...A FEW DEGREES WARMER THAN 00Z MOS.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 223 AM EST SAT DEC 28 2013
MAIN FOCUS TO THE SHORT TERM WILL BE ON TEMPERATURES...ESPECIALLY
SUNDAY AS AN ARCTIC FRONT IS POISED TO DROP SOUTHEAST ACROSS CENTRAL
INDIANA. POPS AND PRECIPITATION TYPE WILL ALSO BE CHALLENGE ON
SUNDAY WITH THE FRONT MOVING THROUGH ALONG WITH A TRAILING UPPER
TROUGH. THE SOUTHERN TROUGH IS ALSO EXPECTED TO BRING RAIN CLOSE
TO...IF NOT ACROSS OUR FAR SOUTH OVERNIGHT SATURDAY NIGHT DEPENDING
ON MODEL OF CHOICE.
00Z GFS AND NAM CLOSE TO THE 12Z ECMWF REGARD HANDLING OF WEAKENING
SOUTHERN PLAINS UPPER LOW AND ALSO WITH THE ARCTIC FRONT.
HOWEVER...MODELS...ESPECIALLY THE GFS HAVE BEEN TRENDING FURTHER
NORTH WITH QPF WITH THE SOUTHERN SYSTEM SATURDAY NIGHT. A BLEND
WOULD WARRANT AT LEAST SMALL POPS AFTER 06Z SUNDAY FOR OUR SOUTHERN
TIER OR TWO. OTHERWISE...SHOULD SEE SKY COVER INCREASE FROM
SOUTH TO NORTH TONIGHT.
MODELS ON SUNDAY SUGGEST THE ARCTIC FRONT WILL BE ACROSS OUR
NORTHWEST COUNTIES SHORTLY AFTER 12Z AND AT OUR EASTERN BORDER
AROUND 18Z. SO...TRIED TO TIME HOURLY TEMPERATURES TO DROP FOLLOWING
THE FRONTAL PASSAGE AND THUS WARMEST TEMPERATURES WILL BE ACROSS THE
EASTERN COUNTIES AND COLDEST NORTHWEST PER 00Z ALLBLEND. WITH DEEPER
SOUTHERN SYSTEM MOISTURE PEELING OF TO THE NORTHEAST AND LITTLE
MOISTURE WITH ARCTIC SYSTEM...KEPT POPS LOW ON SUNDAY. REGARDING
PRECIPITATION TYPE...TRIED TO TIME THE MIX AND CHANGEOVER FROM SNOW
TO RAIN...FOLLOWING CLOSELY BUFKIT BLEND OF CANADIAN PARTIAL
THICKNESSES. THIS WOULD SUGGEST A MIX IN THE NORTHWEST SHORTLY
AFTER 12Z SUNDAY CHANGING TO ALL SNOW DURING THE AFTERNOON. THE
SOUTHEAST SHOULD START OFF AS RAIN AT 12Z AND MIX EARLY AFTERNOON
WITH ALL SNOW LATE AFTERNOON.
WITH THE SOUTHERN SYSTEM WELL NORTHEAST OF THE AREA AND THE NORTHERN
STREAM TROUGH MOISTURE STARVED...WILL NOT MENTION AND POPS SUNDAY
NIGHT.
MONDAY AND MONDAY NIGHT CONTINUE TO LOOK DRY WITH WEAK LOW PRESSURE
SYSTEM JUST TO OUR WEST MONDAY NIGHT MOISTURE STARVED.
00Z ALLBLEND LOOKS LIKE IT IS IN THE BALLPARK FOR TEMPERATURES FOR
THE MOST PART BY SUNDAY NIGHT WITH A FEW TWEAKS NEEDED HERE OR
THERE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 216 PM EST FRI DEC 27 2013
ENSEMBLE DATA SUGGEST MEAN UPPER TROUGHING WILL CONTINUE ACROSS THE
EASTERN PARTS OF THE COUNTRY THROUGH LATE NEXT WEEK. APPEARS THE
MAIN PRECIPITATION THREAT DURING THIS PERIOD WILL BE AROUND NEXT
WEDNESDAY INTO THURSDAY AS ENSEMBLES INDICATE A DISTURBANCE WILL
DROP SOUTHEAST FROM THE NORTHERN PLAINS INTO THE LOCAL AREA BY THAT
TIME. THERE IS A QUITE A SPREAD AMONG THE ENSEMBLES AS TO THE
INTENSITY/TRACK OF THIS SYSTEM. MOST OF THE ENSEMBLES ARE
PROGRESSIVE WITH THIS DISTURBANCE...BUT THERE ARE A FEW THAT SUGGEST
SYSTEM MAY BE STRONG ENOUGH TO CUTOFF OVER THE OHIO VALLEY BY LATE
NEXT WEEK. FOR NOW...WILL GO WITH THE WEAKER MORE PROGRESSIVE
SOLUTIONS AND BRING CHANCE POPS FOR SNOW TO THE AREA WEDNESDAY NIGHT
INTO THURSDAY. POTENTIAL FOR LIGHT ACCUMULATIONS EXIST WITH THIS
SYSTEM.
&&
.AVIATION /DISCUSSION FOR 280600Z TAF ISSUANCE/...
ISSUED AT 1115 PM EST FRI DEC 27 2013
VFR THOUGH THE PERIOD.
HIGH CLOUDS WILL CONTINUE ACROSS INDIANA THROUGH THE PERIOD...WITH A
GRADUAL LOWERING AND INCREASE OF MID AND HIGH CLOUDS IN THE LATTER
HALF OF THE TAF PERIOD.
WINDS 1000FT ABOVE GROUND LEVEL AND ABOVE WILL BE AROUND 30-40KT
TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK
SHORT TERM...MK
LONG TERM....JAS
AVIATION...50
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
200 PM MST SAT DEC 28 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 117 PM MST SAT DEC 28 2013
THE LAST WEEKEND OF 2013 KICKED OFF YESTERDAY WITH WELL ABOVE-NORMAL
TEMPERATURES AND WILL END WITH A VERY COLD SUNDAY. AN ARCTIC COLD
FRONT ON THE WAY TODAY WILL BRING THE COLD AIR AS WELL AS STRONG
WINDS. A FEW FLURRIES ARE POSSIBLE TONIGHT INTO EARLY SUNDAY...BUT
THE MAIN IMPACT OF THIS FRONT WILL BE THE WIND AND COLD. ON SUNDAY
SKIES WILL BECOME MOSTLY SUNNY BUT TEMPERATURES WILL HAVE A TOUGH
TIME GETTING ABOVE FREEZING.
TODAY...SATURDAY...SUNNY AND MILD TO START...BECOMING WINDY AND
COLD. FRONTAL PASSAGE LOOKS TO OCCUR IN THE EARLY AFTERNOON...WITH A
REINFORCING SHOT OF COLD AIR TONIGHT. AHEAD OF THE FRONT IT WILL BE
A NICE DAY SIMILAR TO YESTERDAY WITH SUNNY SKIES...MILD TEMPS...AND
A LIGHT WEST/SOUTHWESTERLY WIND. HIGHS MIGHT EVEN APPROACH RECORD
VALUES TODAY WHICH ARE IN THE MID TO UPPER 60S FOR MOST STATIONS. /RECORD
HIGH OF 67 AT HILL CITY LOOKS TO HAVE THE BEST CHANCE OF BEING
BROKEN OUT OF THE FOUR ASOS SITES./ THE INITIAL FRONT WILL RACE
SOUTH ACROSS THE REGION EARLY THIS AFTERNOON...BRINGING GUSTY WINDS.
DECIDED TO REMOVE THE BLOWING DUST FROM THE WX GRID AS EXPECT ANY
BLOWING DUST/DIRT TO BE VERY LIMITED SPATIALLY/TEMPORALLY BASED ON
THE LATEST SHORT-TERM GUIDANCE. MID/HIGH LEVEL CLOUD COVER
ASSOCIATED WITH THE FRONT WILL ARRIVE LATER THIS AFTERNOON...WITH
LOW-LEVEL STRATUS CLOUDS THIS EVENING.
TONIGHT...STRONG PRESSURE RISES SUPPORT WINDY CONDITIONS THROUGH THE
NIGHT WITH LIGHT SNOW POSSIBLE IN EASTERN COLORADO. OVERCAST SKIES
WITH A LOW STRATUS DECK IN THE EVENING AND MID-LEVEL CLOUDS
PERSISTING THROUGH MOST OF THE NIGHT. WINDS WILL CONTINUE AS STRONG
PRESSURE RISES /5-8 MB/HR/ ARE EXPECTED AND MIXING OCCURS. A FEW
FLURRIES/LIGHT SNOW POSSIBLE IN EASTERN COLORADO AND PORTIONS OF NW
KANSAS WITH THE COMBINATION OF LOW LEVEL MOISTURE AND
FRONTOGENETICAL FORCING IN PLACE. GUIDANCE HAS BEEN QUITE CONSISTENT
RUN-TO-RUN...AND EARLY NCEP RAP AND ESRL RAP RUNS SUPPORT AT LEAST
SOME FLURRIES FOR MOST SPOTS. ACCUMULATIONS ARE NOT EXPECTED TO
AMOUNT TO MUCH...BUT WOULD NOT BE SURPRISED IF WESTERN PARTS OF
CHEYENNE/KIT CARSON COUNTIES IN COLORADO RECEIVE A HALF INCH.
/THOUGH IT WILL BE HARD TO MEASURE WITH ALL THE WIND.../ LOWS WILL
REACH THE SINGLE DIGITS IN MANY LOCATIONS WITH 850MB TEMPS IN THE
-12 TO -15 C RANGE AND STRONG COLD AIR ADVECTION.
TOMORROW...SUNDAY...COLD AND MOSTLY SUNNY. AT DAWN SUNDAY CLOUDS
WILL BE CLEARING FROM NORTHWEST TO SOUTHEAST...BECOMING MOSTLY SUNNY
EVERYWHERE BY THE AFTERNOON. WINDS WILL BE LIGHT OUT OF THE
NORTH/NORTHWEST AT 10 TO 15 MPH. DESPITE THE SUN HIGHS WILL STRUGGLE
TO REACH ABOVE FREEZING AS HIGH PRESSURE STRENGTHENS ACROSS THE
NORTHERN PLAINS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 200 PM MST SAT DEC 28 2013
SUNDAY NIGHT-TUESDAY...PERIODIC INCREASES IN MID AND HIGH CLOUDS
EXPECTED UNDER NORTHWEST FLOW ALOFT. NO PRECIPITATION EXPECTED. MAY
SEE SOME BREEZY NORTHWEST WINDS MONDAY AFTERNOON.
LOWS SUNDAY NIGHT AROUND 10 ACROSS THE EAST AND WESTERN PORTIONS OF
CHEYENNE COUNTY COLORADO...LOW TO MID TEENS ELSEWHERE. HIGHS MONDAY
MID 40S TO AROUND 50. MAY HAVE A BIT OF SNOW COVER TO DEAL WITH
ACROSS THE WEST AND HAVE MID 40S IN THAT AREA. ON TUESDAY 850
TEMPERATURES WARM ABOUT 13-15F ACROSS THE AREA SUPPORTING HIGHS IN
THE MID 50S (NORTHEAST) TO MID 60S (WEST). BIAS CORRECTED GRIDS
ALONG THE 2M/MET/MAV ARE SEVERAL DEGREES COOLER. HAVE GENERALLY
BLENDED ALL SOLUTIONS TRYING TO TREND A BIT CLOSER TO 850
TEMPERATURES. HAVE SETTLED ON LOW TO MID 50S FAR NORTHEAST-EAST WITH
UPREAR 50S TO AROUND 60 ACROSS THE WESTERN/SOUTHWESTERN 2/3 OF THE
AREA.
TUESDAY NIGHT-SATURDAY...THERE IS A SLIGHT CHANCE OF LIGHT
PRECIPITATION WEDNESDAY AS A LARGE AREA OF MOISTURE MOVES IN FROM
THE NORTHWEST...AIDED BY APPROACHING LEFT FRONT PORTION OF UPPER
JET. BETTER CHANCES OF PRECIP GENERALLY ACROSS NORTHEAST 1/2 OF THE
FORECAST AREA. THIS SYSTEM EXITS THE AREA EARLY WEDNESDAY NIGHT.
OTHERWISE...A DRY FORECAST EXPECTED. LOWS THROUGH THURSDAY NIGHT IN
THE TEENS TO LOW 20S WITH MID 20S FRIDAY NIGHT. HIGHS WEDNESDAY IN
THE LOW 30S EAST TO LOW/MID 40S FAR WEST...SLOWLY WARMING INTO THE
LOW TO MID 40S (EAST TO WEST) THURSDAY. ON FRIDAY WE SHOULD RETURN
TO ABOVE NORMAL TEMPERATURES WITH UPPER 40S TO MID 50S. A RETURN TO
NEAR NORMAL HIGHS SATURDAY WITH LOW TO MID 40S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1044 AM MST SAT DEC 28 2013
VFR TO MVFR CONDITIONS EXPECTED AT GLD AND MCK THROUGH THE TAF
PERIOD. VFR CONDITIONS THIS MORNING WILL HOLD THROUGH THE EARLY
AFTERNOON. COLD FRONT DROPPING SOUTH ACROSS THE HIGH PLAINS WILL
BRING A WIND SHIFT AND DRAMATIC INCREASE IN WINDS...WITH GUSTS OVER
30KTS AROUND 21-23Z. WHILE GUSTS COULD CAUSE SOME BLOWING
DUST...BELIEVE ANY VISIBILITY-OBSTRUCTING BLOWING DUST WILL BE
BRIEF. WINDS WILL CONTINUE THROUGH THE NIGHT...GRADUALLY DECREASING
TOWARDS DAWN. EARLY THIS EVENING STRATUS WILL MOVE IN RESULTING IN
MVFR CEILINGS BECOMING VFR. A FEW FLURRIES ARE ALSO POSSIBLE THIS
EVENING AT GLD...BUT CHANCES ARE LOW SO DID NOT INCLUDE A MENTION IN
THIS ISSUANCE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JJM
LONG TERM...99
AVIATION...JJM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
118 PM MST SAT DEC 28 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 117 PM MST SAT DEC 28 2013
THE LAST WEEKEND OF 2013 KICKED OFF YESTERDAY WITH WELL ABOVE-NORMAL
TEMPERATURES AND WILL END WITH A VERY COLD SUNDAY. AN ARCTIC COLD
FRONT ON THE WAY TODAY WILL BRING THE COLD AIR AS WELL AS STRONG
WINDS. A FEW FLURRIES ARE POSSIBLE TONIGHT INTO EARLY SUNDAY...BUT
THE MAIN IMPACT OF THIS FRONT WILL BE THE WIND AND COLD. ON SUNDAY
SKIES WILL BECOME MOSTLY SUNNY BUT TEMPERATURES WILL HAVE A TOUGH
TIME GETTING ABOVE FREEZING.
TODAY...SATURDAY...SUNNY AND MILD TO START...BECOMING WINDY AND
COLD. FRONTAL PASSAGE LOOKS TO OCCUR IN THE EARLY AFTERNOON...WITH A
REINFORCING SHOT OF COLD AIR TONIGHT. AHEAD OF THE FRONT IT WILL BE
A NICE DAY SIMILAR TO YESTERDAY WITH SUNNY SKIES...MILD TEMPS...AND
A LIGHT WEST/SOUTHWESTERLY WIND. HIGHS MIGHT EVEN APPROACH RECORD
VALUES TODAY WHICH ARE IN THE MID TO UPPER 60S FOR MOST STATIONS. /RECORD
HIGH OF 67 AT HILL CITY LOOKS TO HAVE THE BEST CHANCE OF BEING
BROKEN OUT OF THE FOUR ASOS SITES./ THE INITIAL FRONT WILL RACE
SOUTH ACROSS THE REGION EARLY THIS AFTERNOON...BRINGING GUSTY WINDS.
DECIDED TO REMOVE THE BLOWING DUST FROM THE WX GRID AS EXPECT ANY
BLOWING DUST/DIRT TO BE VERY LIMITED SPATIALLY/TEMPORALLY BASED ON
THE LATEST SHORT-TERM GUIDANCE. MID/HIGH LEVEL CLOUD COVER
ASSOCIATED WITH THE FRONT WILL ARRIVE LATER THIS AFTERNOON...WITH
LOW-LEVEL STRATUS CLOUDS THIS EVENING.
TONIGHT...STRONG PRESSURE RISES SUPPORT WINDY CONDITIONS THROUGH THE
NIGHT WITH LIGHT SNOW POSSIBLE IN EASTERN COLORADO. OVERCAST SKIES
WITH A LOW STRATUS DECK IN THE EVENING AND MID-LEVEL CLOUDS
PERSISTING THROUGH MOST OF THE NIGHT. WINDS WILL CONTINUE AS STRONG
PRESSURE RISES /5-8 MB/HR/ ARE EXPECTED AND MIXING OCCURS. A FEW
FLURRIES/LIGHT SNOW POSSIBLE IN EASTERN COLORADO AND PORTIONS OF NW
KANSAS WITH THE COMBINATION OF LOW LEVEL MOISTURE AND
FRONTOGENETICAL FORCING IN PLACE. GUIDANCE HAS BEEN QUITE CONSISTENT
RUN-TO-RUN...AND EARLY NCEP RAP AND ESRL RAP RUNS SUPPORT AT LEAST
SOME FLURRIES FOR MOST SPOTS. ACCUMULATIONS ARE NOT EXPECTED TO
AMOUNT TO MUCH...BUT WOULD NOT BE SURPRISED IF WESTERN PARTS OF
CHEYENNE/KIT CARSON COUNTIES IN COLORADO RECEIVE A HALF INCH.
/THOUGH IT WILL BE HARD TO MEASURE WITH ALL THE WIND.../ LOWS WILL
REACH THE SINGLE DIGITS IN MANY LOCATIONS WITH 850MB TEMPS IN THE
-12 TO -15 C RANGE AND STRONG COLD AIR ADVECTION.
TOMORROW...SUNDAY...COLD AND MOSTLY SUNNY. AT DAWN SUNDAY CLOUDS
WILL BE CLEARING FROM NORTHWEST TO SOUTHEAST...BECOMING MOSTLY SUNNY
EVERYWHERE BY THE AFTERNOON. WINDS WILL BE LIGHT OUT OF THE
NORTH/NORTHWEST AT 10 TO 15 MPH. DESPITE THE SUN HIGHS WILL STRUGGLE
TO REACH ABOVE FREEZING AS HIGH PRESSURE STRENGTHENS ACROSS THE
NORTHERN PLAINS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 202 AM MST SAT DEC 28 2013
SUNDAY NORTH WINDS WILL CONTINUE TO DECLINE AS THE FRONT MOVES
FURTHER SOUTH. AS THE SURFACE HIGH PRESSURE MOVES ACROSS THE AREA A
WEAK WARM FROM WILL DEVELOP BEHIND IT NEAR THE KS/CO BORDER WITH LOW
30S TO THE WEST AND UPPER 20S TO THE EAST. WITH A DRY ENVIRONMENT
OVERHEAD DO NOT EXPECT PRECIP. TO DEVELOP DESPITE THE LEFT EXIT OF
THE 300MB JET MOVING OVER THE AREA.
SUNDAY NIGHT THE LEFT EXIT OF THE 300MB JET WILL LINGER OVER THE
AREA. HOWEVER THE DRY ENVIRONMENT WILL PERSIST SO WILL KEEP THE
FORECAST DRY.
MONDAY THE MID AND UPPER LEVELS MOISTEN BUT LARGE SCALE SUBSIDENCE
WILL MOVE OVER THE AREA NEGATING ANY CHANCE FOR PRECIP. DESPITE THE
MOISTURE TO WORK WITH. DURING THE MORNING A SURFACE TROUGH WILL MOVE
THROUGH THE AREA PUSHING THE WARM FRONT EAST OF THE AREA BY EARLY
AFTERNOON. BEHIND THE FRONT TEMPERATURES WILL WARM TO NEAR NORMAL.
TUESDAY THROUGH FRIDAY...THE UPPER TROUGH OVER THE GREAT LAKES
REGION EXTENDING INTO THE EASTERN U.S. AND THE UPPER RIDGE MOVING
OVER THE WESTERN U.S. WILL BOTH BEGIN TO PUSH EASTWARD TOWARDS THE
LATTER PART OF THE EXTENDED. MEANWHILE...THE CWA WILL BE UNDER
NORTHWEST FLOW ALOFT WITH A FEW MID-UPPER LEVEL SHORTWAVE TROUGHS
CIRCULATING THROUGH THE CWA. THE EXTENDED SHOULD REMAIN DRY AS OF
RIGHT NOW...SINCE SOUNDINGS LOOK DRY AT THE LOW LEVELS THROUGHOUT
THE PERIOD.
THE BACK DOOR COLD FRONT AHEAD OF THE FIRST WAVE WILL MOVE THROUGH
THE CWA TUESDAY NIGHT/WEDNESDAY MORNING...BRINGING IN COOLER
TEMPERATURES. THE GFS IS IN BETTER AGREEMENT WITH THE ECMWF
TONIGHT... AS OPPOSED TO LAST NIGHT...WITH THE COLD AIR MOVING IN.
DUE TO THIS...LOADED CONSALL FOR THE HIGHS ON WEDNESDAY AS THE
ALLBLEND SOLUTION SEEMED TOO WARM. THE NEW ECMWF ALSO HAS ANOTHER
SURGE OF COLD AIR MOVING INTO THE CWA ON THURSDAY. HOWEVER...GIVEN
THAT THE GFS WAS NOT ON BOARD WITH THIS TONIGHT...WHICH INCREASES
UNCERTAINTY AT THIS POINT...DECIDED TO GO WITH THE ALLBLEND SOLUTION
FOR THURSDAY. THIS COULD CHANGE IN THE NEXT FEW DAYS DEPENDING ON
HOW MODELS COME INTO AGREEMENT WITH ONE ANOTHER. CLOUDS WILL
INCREASE ON WEDNESDAY AS THE UPPER LEVEL DISTURBANCE MOVES THROUGH
AND SOUNDINGS SATURATE AT THE MID TO UPPER LEVELS. ANOTHER WEAK
UPPER LEVEL DISTURBANCE WILL MOVE THROUGH THE CWA ON FRIDAY
ACCORDING TO THE GFS. THE ECMWF DOES NOT REALLY HAVE THIS FEATURE AT
THE MOMENT WITH THE RIDGE MOVING EAST...SO NOT SURE AT THIS POINT
HOW THIS WILL AFFECT CLOUD COVER AND/OR TEMPERATURES FOR FRIDAY...SO
WENT WITH THE ALLBLEND SOLUTION FOR DAY 7.
TEMPERATURES THROUGHOUT THE EXTENDED WILL START OUT NEAR TO ABOVE
NORMAL...WITH HIGHS IN THE MID 40S TO LOW 50S ON TUESDAY. THE COLDER
AIR MOVING IN ON WEDNESDAY WILL REALLY AFFECT THE EASTERN COUNTIES
IN THE CWA...WITH HIGHS IN THE LOW TO UPPER 30S...WHILE THE REST OF
THE CWA WILL HAVE HIGHS IN THE LOW TO MID 40S. TEMPERATURES WILL
START TO WARM UP TOWARDS THE END OF NEXT WEEK...WITH HIGHS IN THE
MID TO UPPER 40S ON THURSDAY AND HIGHS IN THE LOW TO MID 50S ON
FRIDAY. LOWS WILL BE IN THE TEENS TO 20S THROUGHOUT THE EXTENDED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1044 AM MST SAT DEC 28 2013
VFR TO MVFR CONDITIONS EXPECTED AT GLD AND MCK THROUGH THE TAF
PERIOD. VFR CONDITIONS THIS MORNING WILL HOLD THROUGH THE EARLY
AFTERNOON. COLD FRONT DROPPING SOUTH ACROSS THE HIGH PLAINS WILL
BRING A WIND SHIFT AND DRAMATIC INCREASE IN WINDS...WITH GUSTS OVER
30KTS AROUND 21-23Z. WHILE GUSTS COULD CAUSE SOME BLOWING
DUST...BELIEVE ANY VISIBILITY-OBSTRUCTING BLOWING DUST WILL BE
BRIEF. WINDS WILL CONTINUE THROUGH THE NIGHT...GRADUALLY DECREASING
TOWARDS DAWN. EARLY THIS EVENING STRATUS WILL MOVE IN RESULTING IN
MVFR CEILINGS BECOMING VFR. A FEW FLURRIES ARE ALSO POSSIBLE THIS
EVENING AT GLD...BUT CHANCES ARE LOW SO DID NOT INCLUDE A MENTION IN
THIS ISSUANCE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JJM
LONG TERM...JTL/ALW
AVIATION...JJM
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
207 PM CST Sat Dec 28 2013
...Updated long term section...
.SYNOPSIS...
ISSUED AT 1106 AM CST SAT DEC 28 2013
At 12z Saturday a -25c 500mb low was located over west central
Texas. An upper level trough extended from southern Saskatchewan
into southern California. 140 to 160 meter 12hour 500mb height
falls observed across eastern Montana which was just east of
this upper trough. A 700mb baroclinic zone was also located across
eastern Montana with a pool of higher dewpoints observed near this
baroclinic zone. A the surface at 12z Saturday an area of low
pressure was located across southern North Dakota with a cold
front extending west into southeast Montana. Behind this cold
front the surface observations reported gusty northwest winds of
30 to near 40kts, tight surface pressure gradient and a 3 hour
surface pressure fall of 5 to near 10mb.
&&
.SHORT TERM...(This evening through Sunday)
ISSUED AT 159 PM CST SAT DEC 28 2013
Windy conditions will develop behind a cold front that will cross
western Kansas early tonight. Both the 12z NAM and GFS have a
decent handle with th cold front location based on 18z
verification. Also based on the 18z verification it also appears
that the 12z NAM had a slightly better handle with the cold air
located behind this front. The NAM also was doing a good job with
the very windy conditions which were developing in the wake of
this cold front based on the boundary layer and mean mixed layer
winds at 18z. Given this will use the mean mixed layer winds and
boundary layer mean winds from the NAM as a guide for wind speeds
overnight as this cold front crosses western Kansas. At this time
it appears that sustained winds of near 30mph will be possible for
a few hours behind this front front between 03z and 09z, however
given how brief these stronger winds will be, marginal sustained
wind speeds, and good collaboration with our surrounding offices
have decided to hold off issuing a wind advisory for western
Kansas tonight.
Gusty north winds at 20 to 30 mph will continue through early
Sunday morning. Given the cold air advection forecast overnight
and how the NAM verified with the cold air across South Dakota and
Montana earlier today will trend overnight lows towards the cooler
MET solution on lows tonight. Given these overnight lows in the
teens and gusty north winds at 20 to 30 mph the wind chills late
tonight/early Sunday will range from 5 to 10 degrees below zero.
There will also be a chance for some very light precipitation
overnight, mainly along and west of highway 83. In this area the
model soundings indicated the 850mb to 700mb level saturates as
improving frontogenesis develops ahead of an approaching upper
level trough.
On Sunday the gusty north winds will gradually subside during the
afternoon as an area of high pressure at the surface begins to
build into the area from the north. Despite the chance for some
breaks of sun during the afternoon, the 925mb and 850mb
temperatures at 00z Monday suggested highs wills struggle to climb
into the mid 20s to near 30. The warmer temperatures Sunday
afternoon are expected to be located in west central Kansas.
.LONG TERM...(Sunday night through Saturday)
ISSUED AT 206 PM CST SAT DEC 28 2013
he Central High Plains will be in northwest flow aloft as the long
term starts out with mid levels of the atmosphere fairly dry. An
area of high pressure at the surface will be located across the Mid
Mississippi Valley with its axis stretching eastward across Kansas
Sunday evening. Sunday night looks to be cold as mostly clear skies
and light winds are expected allowing for good radiative cooling.
Lows will generally range from the upper single digits across
central Kansas to mid teens across far western Kansas. A warming
trend is expected Monday and Tuesday with winds generally from a
westerly direction. With this downslope component of the wind and
warmer mid level temperatures, highs Monday and Tuesday will reach
into the 40s with a few places across far western Kansas reaching
into the lower 50s Tuesday afternoon. Lows Monday night will be in
the lower 20s.
An upper level shortwave moves through the Northern Plains Tuesday
night and helps push a surface cold front through the Central High
Plains. This will shift winds to more of a northerly direction. The
mid levels of the atmosphere will be fairly dry during this time
frame with partly cloudy skies continuing across southwest Kansas. A
second upper level shortwave is then progged to move through
Nebraska on Wednesday. This will bring a reinforcing shot of cold
air plus a chance of light snow across Nebraska and northern
Kansas. I have continued a slight chance of snow across the I-70
corridor with increasing cloudiness. Otherwise partly cloudy skies
will continue across the forecast area. Lows Wednesday and Thursday
morning will generally range form the upper teens across central
Kansas to upper 20s across far southwestern Kansas. High Wednesday
are only expected to reach into the lower to mid 30s with the
exception of far western Kansas where upper 30s and lower 40s will
be possible.
The remainder of the forecast period looks dry with more of a west
to east zonal pattern developing in the mid to upper levels. High
pressure at the surface will build into the Mississippi Valley with
lee toughing developing across eastern Colorado. Highs Thursday and
Friday will generally be in the 40s with a few places across far
western Kansas reaching into the lower 50s Friday afternoon. Lows
Friday morning look to dip into the lower to mid 20s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 1106 AM CST SAT DEC 28 2013
The 12z NAM and latest HRRR both appear to be doing a decent job
on the location of a cold front at 15z. Will therefore use these
for timing of the frontal passage as it crosses western Kansas
early this evening. With this in mind frontal passage will occur
at HYS and GCK around 01z and then DDC around 03z. Once this front
passages north winds will increase into the 20 to near 25kt range.
The stronger winds overnight are expected between 06z and 12z. Low
clouds are also expected to spread across western Kansas overnight
behind this front. Based on model soundings will trend towards a
brief period of MVFR cigs behind this front followed by low VFR
cigs after 06z and persisting through 18z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 14 25 10 46 / 0 0 0 0
GCK 14 27 12 47 / 10 10 0 0
EHA 17 28 17 47 / 10 20 0 0
LBL 16 28 11 47 / 0 10 0 0
HYS 14 25 8 45 / 0 0 0 0
P28 17 26 12 42 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Burgert
SHORT TERM...Burgert
LONG TERM...Hovorka_42
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
203 PM CST Sat Dec 28 2013
...Updated short term discussion...
.SYNOPSIS...
ISSUED AT 1106 AM CST SAT DEC 28 2013
At 12z Saturday a -25c 500mb low was located over west central
Texas. An upper level trough extended from southern Saskatchewan
into southern California. 140 to 160 meter 12hour 500mb height
falls observed across eastern Montana which was just east of
this upper trough. A 700mb baroclinic zone was also located across
eastern Montana with a pool of higher dewpoints observed near this
baroclinic zone. A the surface at 12z Saturday an area of low
pressure was located across southern North Dakota with a cold
front extending west into southeast Montana. Behind this cold
front the surface observations reported gusty northwest winds of
30 to near 40kts, tight surface pressure gradient and a 3 hour
surface pressure fall of 5 to near 10mb.
&&
.SHORT TERM...(This evening through Sunday)
ISSUED AT 159 PM CST SAT DEC 28 2013
Windy conditions will develop behind a cold front that will cross
western Kansas early tonight. Both the 12z NAM and GFS have a
decent handle with th cold front location based on 18z
verification. Also based on the 18z verification it also appears
that the 12z NAM had a slightly better handle with the cold air
located behind this front. The NAM also was doing a good job with
the very windy conditions which were developing in the wake of
this cold front based on the boundary layer and mean mixed layer
winds at 18z. Given this will use the mean mixed layer winds and
boundary layer mean winds from the NAM as a guide for wind speeds
overnight as this cold front crosses western Kansas. At this time
it appears that sustained winds of near 30mph will be possible for
a few hours behind this front front between 03z and 09z, however
given how brief these stronger winds will be, marginal sustained
wind speeds, and good collaboration with our surrounding offices
have decided to hold off issuing a wind advisory for western
Kansas tonight.
Gusty north winds at 20 to 30 mph will continue through early
Sunday morning. Given the cold air advection forecast overnight
and how the NAM verified with the cold air across South Dakota and
Montana earlier today will trend overnight lows towards the cooler
MET solution on lows tonight. Given these overnight lows in the
teens and gusty north winds at 20 to 30 mph the wind chills late
tonight/early Sunday will range from 5 to 10 degrees below zero.
There will also be a chance for some very light precipitation
overnight, mainly along and west of highway 83. In this area the
model soundings indicated the 850mb to 700mb level saturates as
improving frontogenesis develops ahead of an approaching upper
level trough.
On Sunday the gusty north winds will gradually subside during the
afternoon as an area of high pressure at the surface begins to
build into the area from the north. Despite the chance for some
breaks of sun during the afternoon, the 925mb and 850mb
temperatures at 00z Monday suggested highs wills struggle to climb
into the mid 20s to near 30. The warmer temperatures Sunday
afternoon are expected to be located in west central Kansas.
.LONG TERM...(Sunday through Friday)
ISSUED AT 154 AM CST SAT DEC 28 2013
Not a whole lot has changed in the overall forecast thinking
regarding the Sunday through Monday Night forecast. Only negligible
changes were made to the grids Sunday and Sunday Night as the
inherited forecast was on track. One of the challenges Sunday will
be how quickly the winds will decrease through the day. The MSLP
gradient will relax as the ridge axis approaches western Kansas by
afternoon. Temperatures will likely fall fairly quickly at sunset
Sunday Night as winds drop off substantially. We should see
temperatures well into the mid to upper teens by mid to late
evening...before stabilizing in the 06-12z time frame in the 9 to
15F range across much of the southwest Kansas region. Winds will
increase just a bit 09-12Z from the southwest as a new lee trough
forms in response to the next northwest flow jet streak.
The Monday forecast temperature was increased 3-5 degF across the
board as it now looks like the west-northwest boundary layer
downslope momentum will really eat away at this cold airmass...and
quickly... especially west of Highway 283. An improvement of 35 degF
over the morning lows is quite likely with afternoon temperatures
reaching the 45-47 degF range west of a Meade-Dodge City-Lacrosse
line. The surface arctic front will become quasi-stationary across
the Northern Plains Tuesday, but still north of the southwest Kansas
region so Tuesday looks fairly pleasant all things considered with
temperatures improving to the upper 40s/lower 50s for much of the
area. This front will move south Tuesday Night, per the latest ECMWF
and GFS, and will usher in another round of cold air. It was a
collaborative decision among four of the offices (DDC, GLD, GID,
ICT) to go with colder CONSALL guidance instead of the baseline
AllBlend given the degree of cold air and higher confidence in the
shallow arctic air affecting the Central Plains mid-week. The
remainder of the tail-end of the Long Term was unchanged from the
AllBlend guidance...but this forecast is very low confidence
depending on what evolves with the arctic airmass. Colder
temperatures may be forecast for Thursday and beyond in future
updates.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 1106 AM CST SAT DEC 28 2013
The 12z NAM and latest HRRR both appear to be doing a decent job
on the location of a cold front at 15z. Will therefore use these
for timing of the frontal passage as it crosses western Kansas
early this evening. With this in mind frontal passage will occur
at HYS and GCK around 01z and then DDC around 03z. Once this front
passages north winds will increase into the 20 to near 25kt range.
The stronger winds overnight are expected between 06z and 12z. Low
clouds are also expected to spread across western Kansas overnight
behind this front. Based on model soundings will trend towards a
brief period of MVFR cigs behind this front followed by low VFR
cigs after 06z and persisting through 18z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 14 25 10 45 / 0 0 0 0
GCK 14 27 12 47 / 10 10 0 0
EHA 17 28 17 47 / 10 20 0 0
LBL 16 28 10 47 / 0 10 0 0
HYS 14 25 8 45 / 0 0 0 0
P28 17 26 12 41 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Burgert
SHORT TERM...Burgert
LONG TERM...Umscheid
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1109 AM CST Sat Dec 28 2013
...Updated synopsis and aviation discussion...
.SYNOPSIS...
ISSUED AT 1106 AM CST SAT DEC 28 2013
At 12z Saturday a -25c 500mb low was located over west central
Texas. An upper level trough extended from southern Saskatchewan
into southern California. 140 to 160 meter 12hour 500mb height
falls observed across eastern Montana which was just east of
this upper trough. A 700mb baroclinic zone was also located across
eastern Montana with a pool of higher dewpoints observed near this
baroclinic zone. A the surface at 12z Saturday an area of low
pressure was located across southern North Dakota with a cold
front extending west into southeast Montana. Behind this cold
front the surface observations reported gusty northwest winds of
30 to near 40kts, tight surface pressure gradient and a 3 hour
surface pressure fall of 5 to near 10mb.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 100 AM CST SAT DEC 28 2013
Short range models indicate the closed off upper level low in west
Texas lifting northeast into southern Oklahoma today then kicking
eastward into Arkansas Saturday night. Meanwhile, the upper level
shortwave in the Pacific Northwest will dig southeast into the
central Rockies and Four Corners Region today bringing snow chances
to the high country late this afternoon into tonight. Otherwise, a
weak unorganized flow aloft and an extremely dry lower/mid levels
will result in dry conditions persisting across western Kansas
through Saturday evening. There is an outside shot for snow
flurries across west central and extreme southwest Kansas after
midnight Saturday night as the upper level shortwave kicks out of
the Rockies into the Western High Plains. However, no accumulations
are expected through early Sunday morning.
Similar temperatures are expected for highs from yesterday into
today as a prevailing lee side trough continues to influence a
light southwest flow across western Kansas through this afternoon.
This will reinforce the warmer air mass in place across western
Kansas resulting in highs up into the 50s(F) and the lower 60s(F).
The coolest temperatures, with a few upper 40s(F) possible, will
once again reside across a narrow corridor from far eastern
portions of southwest Kansas just east of Dodge City northeastward
into central Kansas near Larned where the last of the lingering
snowpack resides. Much colder air will spill southward into
western Kansas Saturday night in wake of a strong cold front
pushing through early to mid evening. The NAM/GFS show the 0C
isotherm diving well into north Texas with H85 temperatures around
or just under 10C below across central and much of southwest
Kansas. Look for lows down into the Teens(F) across west central
and central Kansas to near 20F possible closer to the Oklahoma
border.
.LONG TERM...(Sunday through Friday)
ISSUED AT 154 AM CST SAT DEC 28 2013
Not a whole lot has changed in the overall forecast thinking
regarding the Sunday through Monday Night forecast. Only negligible
changes were made to the grids Sunday and Sunday Night as the
inherited forecast was on track. One of the challenges Sunday will
be how quickly the winds will decrease through the day. The MSLP
gradient will relax as the ridge axis approaches western Kansas by
afternoon. Temperatures will likely fall fairly quickly at sunset
Sunday Night as winds drop off substantially. We should see
temperatures well into the mid to upper teens by mid to late
evening...before stabilizing in the 06-12z time frame in the 9 to
15F range across much of the southwest Kansas region. Winds will
increase just a bit 09-12Z from the southwest as a new lee trough
forms in response to the next northwest flow jet streak.
The Monday forecast temperature was increased 3-5 degF across the
board as it now looks like the west-northwest boundary layer
downslope momentum will really eat away at this cold airmass...and
quickly... especially west of Highway 283. An improvement of 35 degF
over the morning lows is quite likely with afternoon temperatures
reaching the 45-47 degF range west of a Meade-Dodge City-Lacrosse
line. The surface arctic front will become quasi-stationary across
the Northern Plains Tuesday, but still north of the southwest Kansas
region so Tuesday looks fairly pleasant all things considered with
temperatures improving to the upper 40s/lower 50s for much of the
area. This front will move south Tuesday Night, per the latest ECMWF
and GFS, and will usher in another round of cold air. It was a
collaborative decision among four of the offices (DDC, GLD, GID,
ICT) to go with colder CONSALL guidance instead of the baseline
AllBlend given the degree of cold air and higher confidence in the
shallow arctic air affecting the Central Plains mid-week. The
remainder of the tail-end of the Long Term was unchanged from the
AllBlend guidance...but this forecast is very low confidence
depending on what evolves with the arctic airmass. Colder
temperatures may be forecast for Thursday and beyond in future
updates.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 1106 AM CST SAT DEC 28 2013
The 12z NAM and latest HRRR both appear to be doing a decent job
on the location of a cold front at 15z. Will therefore use these
for timing of the frontal passage as it crosses western Kansas
early this evening. With this in mind frontal passage will occur
at HYS and GCK around 01z and then DDC around 03z. Once this front
passages north winds will increase into the 20 to near 25kt range.
The stronger winds overnight are expected between 06z and 12z. Low
clouds are also expected to spread across western Kansas overnight
behind this front. Based on model soundings will trend towards a
brief period of MVFR cigs behind this front followed by low VFR
cigs after 06z and persisting through 18z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 57 17 25 10 / 0 0 10 0
GCK 63 17 26 12 / 0 10 10 0
EHA 63 18 30 17 / 0 10 10 0
LBL 61 18 26 10 / 0 10 10 0
HYS 65 15 24 8 / 0 0 0 0
P28 60 18 24 12 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Burgert
SHORT TERM...JJohnson
LONG TERM...Umscheid
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1134 AM CST SAT DEC 28 2013
.AVIATION...
BASED ON SHORT-TERM RADAR TRENDS...MORE MODERATE RAIN AREAS WERE
SLOWLY SHRINKING WITH MUCH OF THE RAIN SHIELD BECOMING -RA IN THE
NEXT 1-2 HOURS. IFR CEILINGS WERE ALSO LIFTING OUTSIDE HEAVIER
RAIN CLUSTERS. LATEST RUC RUN SHOWS RAIN BRIEFLY TAPERING THEN
RETURNING IN THE AFTERNOON WITH LIGHT AMOUNTS FROM ELEVATED
CEILINGS AROUND 10KFT. WILL SHOW OPTMISTIC TREND OF IMPROVEMENT TO
VFR CIGS/VSBY THOUGH MAINTAINING -RA THROUGH EARLY EVENING...THEN
GENERAL VFR CAVOK/NSW AFTER 02Z. EXCEPTION MAY BE KNEW WITH MARINE
INFLUENCES KEEPING LOW CLOUD DECK LONGER INTO THE NIGHT. VFR CAVOK
CONDITIONS EXPECTED SUNDAY. 24/RR
&&
.PREV DISCUSSION... /ISSUED 401 AM CST SAT DEC 28 2013/
SHORT TERM...
LATEST ANALYSIS SHOWS CLOSED UPPER LEVEL LOW CENTERED NEAR MIDLAND
TEXAS AND A WEAK SURFACE TROUGH OVER THE SOUTHWEST GULF. WATER VAPOR
IMAGERY DEPICTS INCREASING SUBTROPICAL MOISTURE SURGING
NORTHEASTWARD FROM THE PACIFIC TO THE NORTHERN GULF COAST. RADAR
SHOWS NEARLY COMPLETE AREAL COVERAGE OF STRATIFORM SHOWERS ACROSS
THE CWA. WITH THIS EXPECTED TO CONTINUE MUCH OF THE DAY...INCREASED
POPS TO 100 PERCENT AREAWIDE. THERE COULD BE PERIODS OF MODERATE TO
OCCASIONALLY HEAVY RAIN LATER TODAY AS THE SURFACE LOW DEEPENS AND
TRACKS NORTHEAST ACROSS THE COASTAL WATERS. OVERALL RAINFALL TOTALS
STILL LOOK TO BE AROUND 1 TO 2 INCHES WITH POSSIBLY HIGHER AMOUNTS
ALONG THE COAST. TEMPERATURES TODAY WILL ONLY MODERATE SLIGHTLY WITH
SUCH EXTENSIVE RAIN COVERAGE...SO HAVE KEPT HIGHS IN THE LOWER 50S.
AN UPPER LEVEL TROUGH DIVING SOUTH ACROSS THE CENTRAL PLAINS TONIGHT
WILL ABSORB THE CLOSED LOW AS IT MOVES ACROSS TX/OK/AR. WE WILL BE
DRYING OUT ON SUNDAY AS THE OPENING UPPER LOW KICKS NORTHEAST AND
BRINGS IN SURFACE RIDGE. HIGHS STILL BELOW NORMAL BUT WARMER THAN
THE LAST FEW DAYS.
LONG TERM...
THERE WILL BE LITTLE TIME BEFORE A REINFORCING BOUNDARY MOVES IN.
THIS NEXT FRONT SHOULD SWING THROUGH MONDAY AS THE MAIN UPPER LEVEL
TROUGH FROM CANADA DIGS OVER THE SOUTHEAST. WILL KEEP THE FORECAST
DRY ON MONDAY AS ECMWF AND GFS SUGGEST NO RAIN AND MOISTURE RETURN
IS NOT EXPECTED TO OCCUR BETWEEN SYSTEMS. TEMPERATURES WILL THUS
REMAIN WELL BELOW NORMAL THROUGH TUESDAY AS HIGH PRESSURE BUILDS IN.
THE REMAINDER OF THE FORECAST IS A BIT UNCERTAIN. THE ECMWF SUGGESTS
A NEAR REPEAT OF TODAY ON WEDNESDAY WITH UPPER LOW PULLING OUT OF
TEXAS WITH A SURFACE LOW TRACKING ACROSS THE GULF COAST. THE GFS/S
PREVIOUS RUN SHOWED SOMETHING SIMILAR BUT HAS BACKED OFF SOLUTION
AND NOW JUST SHOWS AN OPEN WAVE BRINGING A FRONT THROUGH AND THUS
KEEPS THE AREA DRY. WITH SUCH LARGE DISCREPANCIES IN POPS...HAVE
DROPPED PREVIOUS FORECAST BUT STILL HAVE CHANCE POPS IN THE THE
ZONES.
MEFFER
AVIATION...SHRA CONTINUE TO INCREASE ACROSS THE REGION AND AS THE
ATMOSPHERE MOISTENS UP THE LOW CLOUDS WILL CONTINUE TO BUILD
EVENTUALLY LOWERING TO AROUND 700-1K FT. LOW CLOUDS AND RAIN WILL
IMPACT ALL TERMINALS MUCH OF THE DAY. CONDITIONS WONT SIGNIFICANTLY
IMPROVE UNTIL AT LEAST 00Z IF NOT LATER. /CAB/
MARINE...A GULF LOW IS ALREADY DEVELOPING OVER THE N-CNTRL GULF AND
WILL DEEPEN THROUGH THE DAY AS IT MOVES CLOSE TO THE MOUTH OF THE
RIVER. THIS IS ALREADY LEADING TO STRONG WINDS ERLY WINDS OVER THE
WATERS EAST OF THE MS RIVER AND NRLY WINDS WEST OF THE RIVER. A SCY
IS ALREADY IN PLACE FOR ALL OF THE OPEN WATERS FOR WINDS OF 20-25
KTS. THE LOW WILL PULL OFF TO THE NORTHEAST QUICKLY TONIGHT AND
WINDS WILL BEGIN TO BACK OFF BUT THIS WILL BE SHORT LIVED. ANOTHER
SHOT OF COLD AIR WILL WORK DOWN INTO THE REGION MON NIGHT AND THIS
WILL LEAD TO A RETURN OF STRONG OFFSHORE WINDS. MDLS THEN BEGIN TO
HAVE SIGNIFICANT DIFFERENCES AFTER THE NEW YEAR. THERE ARE
INDICATIONS THAT ANOTHER GULF LOW COULD DEVELOP ON NEW YEARS DAY
WITH ANOTHER STRONG SHOT OF COLD AIR THU/THU NIGHT LEADING TO
ADDITIONAL STRONG WINDS. /CAB/
DECISION SUPPORT...
DSS CODE...BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT...SMALL CRAFT ADV
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 51 37 61 39 / 100 70 10 10
BTR 52 40 63 42 / 100 70 10 10
ASD 53 42 62 41 / 100 80 10 10
MSY 53 43 61 44 / 100 80 10 10
GPT 53 44 62 43 / 100 90 10 10
PQL 53 45 62 42 / 100 90 10 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 9 PM SATURDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST
PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS
FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60
NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA
OUT 20 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER
ATCHAFALAYA RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM
PORT FOURCHON TO LOWER ATCHAFALAYA RIVER OUT 20
NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST
PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL
WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO
PORT FOURCHON FROM 20 TO 60 NM...AND COASTAL WATERS FROM
THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT
FOURCHON OUT 20 NM.
MS...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 9 PM SATURDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST
PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS
FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60
NM...COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA
OUT 20 NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER
ATCHAFALAYA RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM
PORT FOURCHON TO LOWER ATCHAFALAYA RIVER OUT 20
NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST
PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL
WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO
PORT FOURCHON FROM 20 TO 60 NM...AND COASTAL WATERS FROM
THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT
FOURCHON OUT 20 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
1056 PM EST SUN DEC 29 2013
.SYNOPSIS...
LOW PRESSURE WILL MOVE RAPIDLY THROUGH THE GULF OF MAINE TONIGHT
AND WILL BE LOCATED NEAR HALIFAX NOVA SCOTIA BY MONDAY MORNING.
HIGH PRESSURE WILL BUILD OVER THE REGION MONDAY. WEAK LOW PRESSURE
WILL MOVE THROUGH CENTRAL NEW ENGLAND TUESDAY AFTERNOON. HIGH
PRESSURE WILL BUILD OVER THE REGION WEDNESDAY. LOW PRESSURE WILL
GATHER STRENGTH OVER THE MID ATLANTIC STATES THURSDAY AND MOVE
NORTHEAST SOUTH OF CAPE COD FRIDAY. HIGH PRESSURE WILL BUILD OVER
THE NORTHEAST SATURDAY AND MOVE SOUTHEAST OF THE REGION SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
UPDATED TO DROP THE WINTER WX HEADLINES FOR COASTAL CUMBERLAND AND
COASTAL YORK COUNTIES IN SW MAINE AND FOR INTERIOR ROCKINGHAM
COUNTY IN SE NH. PRCP HAS BEEN MOSTLY RAIN WITH SOME MIX OR CHANGE
OVER TO SN BUT ANY ACCUMULATIONS HAVE BEEN AN OR OR LESS FOR THESE
AREAS WITH PERHAPS A COUPLE INCHES WELL AWAY FROM THE COAST. ANY
ADDITIONAL SNOW ACCUMULATIONS WILL GIVE TOTALS NO MORE THAN 2-4
INCHES IN THESE AREAS...WITH EVEN LESS ALONG THE SHORE LINE.
PREVIOUS DISCUSSION...
UPDATED TO INPUT LATEST OBSERVED DATA. STILL SEEING MIXED PRCP OR
RAIN SRN NH AND COASTAL INTO ADJACENT INTERIOR AREAS THIS EVE.
BACK EDGE OF PRCP ALREADY MOVING INTO NY STATE AS SUPPORTED BY
MODELS MOVING SYSTEM THRU REAL FAST...BY 06Z IT`S OVER FOR ALL BUT
MAYBE EXTREME ERN ZONES. WILL BE TOUGH TO GET HIGH SNOW TOTALS...
ESPECIALLY WITH RAIN AND MIXED AT THIS TIME WHICH WILL CUT INTO
TOTAL QPF AMOUNTS AVBL FOR PRODUCING SNOW. WON`T BACK OFF ON
HEADLINES YET...BUT WILL BE UPDATING THIS EVE AS THINGS PROGRESS.
PREVIOUS DISCUSSION...
COLD FRONT HAS PUSHED SOUTH THROUGH THE MIDCOAST AND IS NOW
LOCATED FROM WISCASSET TO LEWISTON BEFORE GETTING HUNG UP IN THE
HILL COUNTRY NEAR RUMFORD. TEMPERATURES BEHIND THE FRONT HAVE BEEN
FALLING INTO THE MID 20S AS NOTED OVER THE PAST FEW HOURS AT
BANGOR AND WATERVILLE. THIS FRONT MAY PLAY A KEY ROLE IN
DETERMINING PRECIPITATION TYPE ACROSS THE MIDCOAST REGION TONIGHT.
LOW PRESSURE CURRENTLY JUST SOUTHEAST OF PHILADELPHIA WILL TRACK
QUICKLY NORTHEAST ACROSS CAPE COD AND TO NOVA SCOTIA TONIGHT.
LARGE AREA OF PRECIPITATION HAS SPREAD NORTHWARD AHEAD OF THIS
LOW... NOW SPREADING ACROSS ALL OF SOUTHERN NEW ENGLAND AND
PUSHING INTO SOUTHERN NEW HAMPSHIRE. THIS PRECIPITATION WILL
CONTINUE TO SPREAD NORTHEAST ACROSS NEW HAMPSHIRE AND MAINE
OVERNIGHT... BRINGING A QUICK... BUT HEAVY... ROUND OF
PRECIPITATION BEFORE EXITING JUST AFTER MIDNIGHT.
PRECIPITATION TYPE CONTINUES TO BE A COMPLEX PICTURE WITH THIS
STORM... AS TEMPERATURES THROUGH THE LOWEST FEW THOUSAND FEET WILL
BE NEAR FREEZING ACROSS MUCH OF SOUTHERN NEW HAMPSHIRE AND COASTAL
MAINE. NAM AND HRRR MODELS CONTINUE TO SHOW A COLDER SOLUTION...
WITH TEMPERATURES AT OR JUST BELOW FREEZING AS PRECIPITATION FALLS
THIS EVENING. IT IS EXPECTED THAT AS PRECIPITATION BEGINS TO
INTENSIFY... TEMPERATURES WITHIN THE ATMOSPHERIC PROFILE WILL COOL
AND ALLOW A HEAVY WET SNOW TO FALL. LOTS OF MOISTURE AND GOOD
DYNAMICS WITH THIS SYSTEM WILL ALLOW INTENSE PRECIPITATION
RATES... WITH TOTAL QPF TONIGHT RANGING FROM 0.75 TO 1.00 INCH.
SNOW RATIOS WILL BE NEAR 10 TO 1 DUE TO THE LARGE ISOTHERMAL LAYER
IN THE LOW LEVELS ESPECIALLY OVER SOUTHERN AND CENTRAL NEW
HAMPSHIRE EXTENDING TO THE MAINE COAST. NORTH OF THE PREVIOUSLY
MENTIONED COLD FRONT... TEMPERATURES WILL BE A BIT COLDER...
LEADING TO MORE CERTAINTY THAT PRECIPITATION WILL FALL IN THE FORM
OF SNOW AND ALLOW SNOW RATIOS TO BE A BIT HIGHER... POSSIBLY 13 TO
1.
THERE IS A GOOD AMOUNT OF CONFIDENCE THAT A BAND OF 6 TO 10 INCHES
OF SNOW WILL FALL... THOUGH THE TRANSITION TO RAIN NEAR THE COAST
IS STILL THE BIGGEST QUESTION MARK. IT IS POSSIBLE THAT THE
IMMEDIATE COASTLINE MAY SEE ONLY AN INCH OR TWO OF SNOW WHILE
AREAS JUST INLAND COULD SEE 6 TO 10. WITH THE COLDER FORECAST...
THE WINTER STORM WARNINGS HAVE BEEN EXTENDED TO THE COAST FROM
PORTLAND EASTWARD. THIS AREA WAS ALSO HIT HARD BY THE ICE STORM
LAST WEEKEND AND THE TREES ARE LIKELY STILL SUPPORTING A LOAD OF
ICE FROM THIS. WITH THE ADDITIONAL STICKY... WET SNOW EXPECTED...
THIS COULD CAUSE ADDITIONAL POWER OUTAGES EVEN IF THE 6 INCH
WARNING CRITERIA IS NOT MET.
SNOWFALL RATES WILL LIKELY BE QUITE INTENSE THIS EVENING... WITH 1
TO 2 INCHES PER HOUR COMMON AND RATES UP TO 3 INCHES PER HOUR
POSSIBLE. THIS WILL MAKE IT MORE DIFFICULT FOR ROAD CREWS TO KEEP
UP WITH SNOW REMOVAL DURING THE HEAVIEST PERIOD OF SNOW... CAUSING
EVEN GREATER IMPACTS ON TRAVEL. ALL THESE FACTORS WERE CONSIDERED
IN THE PLACING OF WINTER STORM WARNINGS AND WINTER WEATHER ADVISORIES.
FURTHER TO THE NORTH... THERE WILL LIKELY BE A SHARP CUT OFF IN
SNOWFALL AMOUNTS INLAND OF THE HEAVIEST BAND. LOCATIONS NEAR THE
CANADIAN BORDER MAY NOT SEE MUCH SNOW AT ALL... AND NORTHERN COOS
COUNTY HAS BEEN DROPPED FROM THE ADVISORY AS FORECAST SNOWFALL
AMOUNTS IN THIS REGION ARE ONLY 1 TO 2 INCHES. THE NORTHERN ZONES
IN WESTERN MAINE WERE LEFT IN AS THE SOUTHERN PORTION OF THESE
ZONES STILL HAS A THREAT FOR HIGHER TOTALS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
AS LOW PRESSURE MOVES EAST... A COLD FRONT WILL PUSH SOUTHEAST
ACROSS NEW ENGLAND ON MONDAY. A VERY COLD AIR MASS HAS BEEN
LURKING BEHIND THIS FRONT... AND THIS WILL BE FELT IN FULL FORCE
BY MONDAY AFTERNOON. TEMPERATURES WILL LIKELY BE FALLING THROUGH
THE DAY AS COLD ADVECTION TAKES OVER. WINDS COULD GUST TO 25 MPH
AS COLD ADVECTION ALLOWS GOOD MIXING TO TAKE PLACE.
TEMPERATURES FALL TO NEAR OR BELOW ZERO ACROSS THE ENTIRE FORECAST
AREA MONDAY NIGHT. READINGS AS COLD AS 20 BELOW ARE POSSIBLE TO
THE NORTH OF THE MOUNTAINS WHERE COLD AIR WILL BE EVEN MORE
INTENSE. WIND CHILL ADVISORIES OR WARNINGS MAY BE NEEDED AS WIND
CHILLS COULD REACH 30 BELOW.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
MODELS IN AGREEMENT THROUGH THE PERIOD FOR A COLD WEEK. A WEAK SHORT
WAVE WILL MOVE THROUGH NEW HAMPSHIRE AND MAINE TUESDAY AFTERNOON
WITH ASSOCIATED SNOW SHOWERS AND USHER IN EVEN COLDER AIR. WIND
CHILL ADVISORIES MAY BE NEEDED TUESDAY NIGHT AND WEDNESDAY. HIGH
PRESSURE CRESTS OVERHEAD WEDNESDAY. LATE IN THE DAY CLOUDS STREAM
EAST. LIGHT SNOW DEVELOPS THURSDAY AS LOW PRESSURE DEVELOPS SOUTH
OF LONG ISLAND NEW YORK. GFS AND ECMWF SIMILAR IN THE TRACK AND
LINGER SNOW INTO FRIDAY. SEVERAL INCHES OF SNOW POSSIBLE WITH THIS
SYSTEM. ANOTHER ARCTIC SHOT OF AIR ARRIVES FRIDAY AFTERNOON AND
SATURDAY. A WARM FRONT WILL MOVE NORTH SUNDAY.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH THURSDAY NIGHT/...VARIABLE CONDITIONS BUT
MOSTLY LIFR THIS EVE...IMPROVE FROM SW TO NE AROUND MIDNIGHT AS
PRCP COMES TO AN END FAIRLY QUICKLY FROM THIS FAST MOVING SYSTEM.
PRCP TYPE WILL BE PROBLEMATIC WITH MIXED WINTRY PRCP EXPECTED
ALONG WITH PRCP CHANGING FROM RAIN OR MIXED TO MIXED OR SNOW
BEFORE ENDING. IMPROVING TO VFR EXCEPT MVFR N/MT ZONES LATER TNGT
AND MONDAY. GUSTY NW WINDS PSBL MONDAY. VFR MONDAY NGT.
LONG TERM...POSSIBLE MVFR IN SNOW SHOWERS TUESDAY AND WEDNESDAY.
IFR MOVES IN THURSDAY AFTERNOON AND MOVES OUT FRIDAY. VFR
SATURDAY AND SUNDAY.
&&
.MARINE...
SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...UPDATED TO INPUT
LATEST OBSERVED DATA. WILL CONT HEADLINES...INCREASED WINDS PER
LATEST BUOY REPORTS. WINDS PICKING UP AS LOW HAS INTENSIFIED MORE
THAN WHAT MODELS HAD PREDICTED.
PREVIOUS DISCUSSION...
LOW PRESSURE MOVING FROM CAPE COD TO NOVA SCOTIA WILL BRING A
BRIEF PERIOD OF NORTHEAST WINDS WHICH COULD GUST TO GALE FORCE.
WINDS SHIFT TO NORTHWEST BY MORNING. A COLD FRONT PUSHING THROUGH
THE GULF OF MAINE ON MONDAY WILL BRING STRONG COLD ADVECTION AND
THE POTENTIAL FOR MORE GALE FORCE GUSTS THROUGH MONDAY EVENING.
LONG TERM...SMALL CRAFT WINDS TUESDAY AND WEDNESDAY. GALE FORCE
WINDS POSSIBLE THURSDAY AFTERNOON INTO SATURDAY MORNING.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MEZ012>014-
018>022-026>028.
WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR MEZ007>009.
NH...WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR NHZ004>010.
WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR NHZ002-003.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EST MONDAY FOR ANZ151-153.
GALE WARNING UNTIL 9 PM EST MONDAY FOR ANZ150-152-154.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
915 PM EST SUN DEC 29 2013
.SYNOPSIS...
LOW PRESSURE WILL MOVE RAPIDLY THROUGH THE GULF OF MAINE TONIGHT
AND WILL BE LOCATED NEAR HALIFAX NOVA SCOTIA BY MONDAY MORNING.
HIGH PRESSURE WILL BUILD OVER THE REGION MONDAY. WEAK LOW PRESSURE
WILL MOVE THROUGH CENTRAL NEW ENGLAND TUESDAY AFTERNOON. HIGH
PRESSURE WILL BUILD OVER THE REGION WEDNESDAY. LOW PRESSURE WILL
GATHER STRENGTH OVER THE MID ATLANTIC STATES THURSDAY AND MOVE
NORTHEAST SOUTH OF CAPE COD FRIDAY. HIGH PRESSURE WILL BUILD OVER
THE NORTHEAST SATURDAY AND MOVE SOUTHEAST OF THE REGION SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
UPDATED TO DROP THE WINTER WX HEADLINES FOR COASTAL CUMBERLAND AND
COASTAL YORK COUNTIES IN SW MAINE AND FOR INTERIOR ROCKINGHAM
COUNTY IN SE NH. PRCP HAS BEEN MOSTLY RAIN WITH SOME MIX OR CHANGE
OVER TO SN BUT ANY ACCUMULATIONS HAVE BEEN AN OR OR LESS FOR THESE
AREAS WITH PERHAPS A COUPLE INCHES WELL AWAY FROM THE COAST. ANY
ADDITIONAL SNOW ACCUMULATIONS WILL GIVE TOTALS NO MORE THAN 2-4
INCHES IN THESE AREAS...WITH EVEN LESS ALONG THE SHORE LINE.
PREVIOUS DISCUSSION...
UPDATED TO INPUT LATEST OBSERVED DATA. STILL SEEING MIXED PRCP OR
RAIN SRN NH AND COASTAL INTO ADJACENT INTERIOR AREAS THIS EVE.
BACK EDGE OF PRCP ALREADY MOVING INTO NY STATE AS SUPPORTED BY
MODELS MOVING SYSTEM THRU REAL FAST...BY 06Z IT`S OVER FOR ALL BUT
MAYBE EXTREME ERN ZONES. WILL BE TOUGH TO GET HIGH SNOW TOTALS...
ESPECIALLY WITH RAIN AND MIXED AT THIS TIME WHICH WILL CUT INTO
TOTAL QPF AMOUNTS AVBL FOR PRODUCING SNOW. WON`T BACK OFF ON
HEADLINES YET...BUT WILL BE UPDATING THIS EVE AS THINGS PROGRESS.
PREVIOUS DISCUSSION...
COLD FRONT HAS PUSHED SOUTH THROUGH THE MIDCOAST AND IS NOW
LOCATED FROM WISCASSET TO LEWISTON BEFORE GETTING HUNG UP IN THE
HILL COUNTRY NEAR RUMFORD. TEMPERATURES BEHIND THE FRONT HAVE BEEN
FALLING INTO THE MID 20S AS NOTED OVER THE PAST FEW HOURS AT
BANGOR AND WATERVILLE. THIS FRONT MAY PLAY A KEY ROLE IN
DETERMINING PRECIPITATION TYPE ACROSS THE MIDCOAST REGION TONIGHT.
LOW PRESSURE CURRENTLY JUST SOUTHEAST OF PHILADELPHIA WILL TRACK
QUICKLY NORTHEAST ACROSS CAPE COD AND TO NOVA SCOTIA TONIGHT.
LARGE AREA OF PRECIPITATION HAS SPREAD NORTHWARD AHEAD OF THIS
LOW... NOW SPREADING ACROSS ALL OF SOUTHERN NEW ENGLAND AND
PUSHING INTO SOUTHERN NEW HAMPSHIRE. THIS PRECIPITATION WILL
CONTINUE TO SPREAD NORTHEAST ACROSS NEW HAMPSHIRE AND MAINE
OVERNIGHT... BRINGING A QUICK... BUT HEAVY... ROUND OF
PRECIPITATION BEFORE EXITING JUST AFTER MIDNIGHT.
PRECIPITATION TYPE CONTINUES TO BE A COMPLEX PICTURE WITH THIS
STORM... AS TEMPERATURES THROUGH THE LOWEST FEW THOUSAND FEET WILL
BE NEAR FREEZING ACROSS MUCH OF SOUTHERN NEW HAMPSHIRE AND COASTAL
MAINE. NAM AND HRRR MODELS CONTINUE TO SHOW A COLDER SOLUTION...
WITH TEMPERATURES AT OR JUST BELOW FREEZING AS PRECIPITATION FALLS
THIS EVENING. IT IS EXPECTED THAT AS PRECIPITATION BEGINS TO
INTENSIFY... TEMPERATURES WITHIN THE ATMOSPHERIC PROFILE WILL COOL
AND ALLOW A HEAVY WET SNOW TO FALL. LOTS OF MOISTURE AND GOOD
DYNAMICS WITH THIS SYSTEM WILL ALLOW INTENSE PRECIPITATION
RATES... WITH TOTAL QPF TONIGHT RANGING FROM 0.75 TO 1.00 INCH.
SNOW RATIOS WILL BE NEAR 10 TO 1 DUE TO THE LARGE ISOTHERMAL LAYER
IN THE LOW LEVELS ESPECIALLY OVER SOUTHERN AND CENTRAL NEW
HAMPSHIRE EXTENDING TO THE MAINE COAST. NORTH OF THE PREVIOUSLY
MENTIONED COLD FRONT... TEMPERATURES WILL BE A BIT COLDER...
LEADING TO MORE CERTAINTY THAT PRECIPITATION WILL FALL IN THE FORM
OF SNOW AND ALLOW SNOW RATIOS TO BE A BIT HIGHER... POSSIBLY 13 TO
1.
THERE IS A GOOD AMOUNT OF CONFIDENCE THAT A BAND OF 6 TO 10 INCHES
OF SNOW WILL FALL... THOUGH THE TRANSITION TO RAIN NEAR THE COAST
IS STILL THE BIGGEST QUESTION MARK. IT IS POSSIBLE THAT THE
IMMEDIATE COASTLINE MAY SEE ONLY AN INCH OR TWO OF SNOW WHILE
AREAS JUST INLAND COULD SEE 6 TO 10. WITH THE COLDER FORECAST...
THE WINTER STORM WARNINGS HAVE BEEN EXTENDED TO THE COAST FROM
PORTLAND EASTWARD. THIS AREA WAS ALSO HIT HARD BY THE ICE STORM
LAST WEEKEND AND THE TREES ARE LIKELY STILL SUPPORTING A LOAD OF
ICE FROM THIS. WITH THE ADDITIONAL STICKY... WET SNOW EXPECTED...
THIS COULD CAUSE ADDITIONAL POWER OUTAGES EVEN IF THE 6 INCH
WARNING CRITERIA IS NOT MET.
SNOWFALL RATES WILL LIKELY BE QUITE INTENSE THIS EVENING... WITH 1
TO 2 INCHES PER HOUR COMMON AND RATES UP TO 3 INCHES PER HOUR
POSSIBLE. THIS WILL MAKE IT MORE DIFFICULT FOR ROAD CREWS TO KEEP
UP WITH SNOW REMOVAL DURING THE HEAVIEST PERIOD OF SNOW... CAUSING
EVEN GREATER IMPACTS ON TRAVEL. ALL THESE FACTORS WERE CONSIDERED
IN THE PLACING OF WINTER STORM WARNINGS AND WINTER WEATHER ADVISORIES.
FURTHER TO THE NORTH... THERE WILL LIKELY BE A SHARP CUT OFF IN
SNOWFALL AMOUNTS INLAND OF THE HEAVIEST BAND. LOCATIONS NEAR THE
CANADIAN BORDER MAY NOT SEE MUCH SNOW AT ALL... AND NORTHERN COOS
COUNTY HAS BEEN DROPPED FROM THE ADVISORY AS FORECAST SNOWFALL
AMOUNTS IN THIS REGION ARE ONLY 1 TO 2 INCHES. THE NORTHERN ZONES
IN WESTERN MAINE WERE LEFT IN AS THE SOUTHERN PORTION OF THESE
ZONES STILL HAS A THREAT FOR HIGHER TOTALS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
AS LOW PRESSURE MOVES EAST... A COLD FRONT WILL PUSH SOUTHEAST
ACROSS NEW ENGLAND ON MONDAY. A VERY COLD AIR MASS HAS BEEN
LURKING BEHIND THIS FRONT... AND THIS WILL BE FELT IN FULL FORCE
BY MONDAY AFTERNOON. TEMPERATURES WILL LIKELY BE FALLING THROUGH
THE DAY AS COLD ADVECTION TAKES OVER. WINDS COULD GUST TO 25 MPH
AS COLD ADVECTION ALLOWS GOOD MIXING TO TAKE PLACE.
TEMPERATURES FALL TO NEAR OR BELOW ZERO ACROSS THE ENTIRE FORECAST
AREA MONDAY NIGHT. READINGS AS COLD AS 20 BELOW ARE POSSIBLE TO
THE NORTH OF THE MOUNTAINS WHERE COLD AIR WILL BE EVEN MORE
INTENSE. WIND CHILL ADVISORIES OR WARNINGS MAY BE NEEDED AS WIND
CHILLS COULD REACH 30 BELOW.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
MODELS IN AGREEMENT THROUGH THE PERIOD FOR A COLD WEEK. A WEAK SHORT
WAVE WILL MOVE THROUGH NEW HAMPSHIRE AND MAINE TUESDAY AFTERNOON
WITH ASSOCIATED SNOW SHOWERS AND USHER IN EVEN COLDER AIR. WIND
CHILL ADVISORIES MAY BE NEEDED TUESDAY NIGHT AND WEDNESDAY. HIGH
PRESSURE CRESTS OVERHEAD WEDNESDAY. LATE IN THE DAY CLOUDS STREAM
EAST. LIGHT SNOW DEVELOPS THURSDAY AS LOW PRESSURE DEVELOPS SOUTH
OF LONG ISLAND NEW YORK. GFS AND ECMWF SIMILAR IN THE TRACK AND
LINGER SNOW INTO FRIDAY. SEVERAL INCHES OF SNOW POSSIBLE WITH THIS
SYSTEM. ANOTHER ARCTIC SHOT OF AIR ARRIVES FRIDAY AFTERNOON AND
SATURDAY. A WARM FRONT WILL MOVE NORTH SUNDAY.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH THURSDAY NIGHT/...VARIABLE CONDITIONS BUT
MOSTLY LIFR THIS EVE...IMPROVE FROM SW TO NE AROUND MIDNIGHT AS
PRCP COMES TO AN END FAIRLY QUICKLY FROM THIS FAST MOVING SYSTEM.
PRCP TYPE WILL BE PROBLEMATIC WITH MIXED WINTRY PRCP EXPECTED
ALONG WITH PRCP CHANGING FROM RAIN OR MIXED TO MIXED OR SNOW
BEFORE ENDING. IMPROVING TO VFR EXCEPT MVFR N/MT ZONES LATER TNGT
AND MONDAY. GUSTY NW WINDS PSBL MONDAY. VFR MONDAY NGT.
LONG TERM...POSSIBLE MVFR IN SNOW SHOWERS TUESDAY AND WEDNESDAY.
IFR MOVES IN THURSDAY AFTERNOON AND MOVES OUT FRIDAY. VFR
SATURDAY AND SUNDAY.
&&
.MARINE...
SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...UPDATED TO INPUT
LATEST OBSERVED DATA. WILL CONT HEADLINES...BUT MAY BE TOUGH TO
SEE GALE FORCE WINDS WITH THIS EVENT. STILL SOME GUSTS UP TO 35 KT
PSBL OVER THE OPEN WATERS ON MONDAY SO WON`T BACK OFF AT THIS
TIME. HAVE BACKED OFF GUSTS TO JUST 30 KT FOR TNGT OVER THE OPEN
WATERS. WILL CONT GUSTS TO 25 KT FOR THE BAYS TNGT AND INTO MONDAY
BUT THAT MAY BE A STRETCH.
PREVIOUS DISCUSSION...
LOW PRESSURE MOVING FROM CAPE COD TO NOVA SCOTIA WILL BRING A
BRIEF PERIOD OF NORTHEAST WINDS WHICH COULD GUST TO GALE FORCE.
WINDS SHIFT TO NORTHWEST BY MORNING. A COLD FRONT PUSHING THROUGH
THE GULF OF MAINE ON MONDAY WILL BRING STRONG COLD ADVECTION AND
THE POTENTIAL FOR MORE GALE FORCE GUSTS THROUGH MONDAY EVENING.
LONG TERM...SMALL CRAFT WINDS TUESDAY AND WEDNESDAY. GALE FORCE
WINDS POSSIBLE THURSDAY AFTERNOON INTO SATURDAY MORNING.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MEZ012>014-
018>022-026>028.
WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR MEZ007>009.
NH...WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR NHZ004>010.
WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR NHZ002-003.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EST MONDAY FOR ANZ151-153.
GALE WARNING UNTIL 9 PM EST MONDAY FOR ANZ150-152-154.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
637 PM EST SUN DEC 29 2013
.SYNOPSIS...
LOW PRESSURE WILL MOVE RAPIDLY THROUGH THE GULF OF MAINE TONIGHT
AND WILL BE LOCATED NEAR HALIFAX NOVA SCOTIA BY MONDAY MORNING.
HIGH PRESSURE WILL BUILD OVER THE REGION MONDAY. WEAK LOW PRESSURE
WILL MOVE THROUGH CENTRAL NEW ENGLAND TUESDAY AFTERNOON. HIGH
PRESSURE WILL BUILD OVER THE REGION WEDNESDAY. LOW PRESSURE WILL
GATHER STRENGTH OVER THE MID ATLANTIC STATES THURSDAY AND MOVE
NORTHEAST SOUTH OF CAPE COD FRIDAY. HIGH PRESSURE WILL BUILD OVER
THE NORTHEAST SATURDAY AND MOVE SOUTHEAST OF THE REGION SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
UPDATED TO INPUT LATEST OBSERVED DATA. STILL SEEING MIXED PRCP OR
RAIN SRN NH AND COASTAL INTO ADJACENT INTERIOR AREAS THIS EVE.
BACK EDGE OF PRCP ALREADY MOVING INTO NY STATE AS SUPPORTED BY
MODELS MOVING SYSTEM THRU REAL FAST...BY 06Z IT`S OVER FOR ALL BUT
MAYBE EXTREME ERN ZONES. WILL BE TOUGH TO GET HIGH SNOW TOTALS...
ESPECIALLY WITH RAIN AND MIXED AT THIS TIME WHICH WILL CUT INTO
TOTAL QPF AMOUNTS AVBL FOR PRODUCING SNOW. WON`T BACK OFF ON
HEADLINES YET...BUT WILL BE UPDATING THIS EVE AS THINGS PROGRESS.
PREVIOUS DISCUSSION...
COLD FRONT HAS PUSHED SOUTH THROUGH THE MIDCOAST AND IS NOW
LOCATED FROM WISCASSET TO LEWISTON BEFORE GETTING HUNG UP IN THE
HILL COUNTRY NEAR RUMFORD. TEMPERATURES BEHIND THE FRONT HAVE BEEN
FALLING INTO THE MID 20S AS NOTED OVER THE PAST FEW HOURS AT
BANGOR AND WATERVILLE. THIS FRONT MAY PLAY A KEY ROLE IN
DETERMINING PRECIPITATION TYPE ACROSS THE MIDCOAST REGION TONIGHT.
LOW PRESSURE CURRENTLY JUST SOUTHEAST OF PHILADELPHIA WILL TRACK
QUICKLY NORTHEAST ACROSS CAPE COD AND TO NOVA SCOTIA TONIGHT.
LARGE AREA OF PRECIPITATION HAS SPREAD NORTHWARD AHEAD OF THIS
LOW... NOW SPREADING ACROSS ALL OF SOUTHERN NEW ENGLAND AND
PUSHING INTO SOUTHERN NEW HAMPSHIRE. THIS PRECIPITATION WILL
CONTINUE TO SPREAD NORTHEAST ACROSS NEW HAMPSHIRE AND MAINE
OVERNIGHT... BRINGING A QUICK... BUT HEAVY... ROUND OF
PRECIPITATION BEFORE EXITING JUST AFTER MIDNIGHT.
PRECIPITATION TYPE CONTINUES TO BE A COMPLEX PICTURE WITH THIS
STORM... AS TEMPERATURES THROUGH THE LOWEST FEW THOUSAND FEET WILL
BE NEAR FREEZING ACROSS MUCH OF SOUTHERN NEW HAMPSHIRE AND COASTAL
MAINE. NAM AND HRRR MODELS CONTINUE TO SHOW A COLDER SOLUTION...
WITH TEMPERATURES AT OR JUST BELOW FREEZING AS PRECIPITATION FALLS
THIS EVENING. IT IS EXPECTED THAT AS PRECIPITATION BEGINS TO
INTENSIFY... TEMPERATURES WITHIN THE ATMOSPHERIC PROFILE WILL COOL
AND ALLOW A HEAVY WET SNOW TO FALL. LOTS OF MOISTURE AND GOOD
DYNAMICS WITH THIS SYSTEM WILL ALLOW INTENSE PRECIPITATION
RATES... WITH TOTAL QPF TONIGHT RANGING FROM 0.75 TO 1.00 INCH.
SNOW RATIOS WILL BE NEAR 10 TO 1 DUE TO THE LARGE ISOTHERMAL LAYER
IN THE LOW LEVELS ESPECIALLY OVER SOUTHERN AND CENTRAL NEW
HAMPSHIRE EXTENDING TO THE MAINE COAST. NORTH OF THE PREVIOUSLY
MENTIONED COLD FRONT... TEMPERATURES WILL BE A BIT COLDER...
LEADING TO MORE CERTAINTY THAT PRECIPITATION WILL FALL IN THE FORM
OF SNOW AND ALLOW SNOW RATIOS TO BE A BIT HIGHER... POSSIBLY 13 TO
1.
THERE IS A GOOD AMOUNT OF CONFIDENCE THAT A BAND OF 6 TO 10 INCHES
OF SNOW WILL FALL... THOUGH THE TRANSITION TO RAIN NEAR THE COAST
IS STILL THE BIGGEST QUESTION MARK. IT IS POSSIBLE THAT THE
IMMEDIATE COASTLINE MAY SEE ONLY AN INCH OR TWO OF SNOW WHILE
AREAS JUST INLAND COULD SEE 6 TO 10. WITH THE COLDER FORECAST...
THE WINTER STORM WARNINGS HAVE BEEN EXTENDED TO THE COAST FROM
PORTLAND EASTWARD. THIS AREA WAS ALSO HIT HARD BY THE ICE STORM
LAST WEEKEND AND THE TREES ARE LIKELY STILL SUPPORTING A LOAD OF
ICE FROM THIS. WITH THE ADDITIONAL STICKY... WET SNOW EXPECTED...
THIS COULD CAUSE ADDITIONAL POWER OUTAGES EVEN IF THE 6 INCH
WARNING CRITERIA IS NOT MET.
SNOWFALL RATES WILL LIKELY BE QUITE INTENSE THIS EVENING... WITH 1
TO 2 INCHES PER HOUR COMMON AND RATES UP TO 3 INCHES PER HOUR
POSSIBLE. THIS WILL MAKE IT MORE DIFFICULT FOR ROAD CREWS TO KEEP
UP WITH SNOW REMOVAL DURING THE HEAVIEST PERIOD OF SNOW... CAUSING
EVEN GREATER IMPACTS ON TRAVEL. ALL THESE FACTORS WERE CONSIDERED
IN THE PLACING OF WINTER STORM WARNINGS AND WINTER WEATHER ADVISORIES.
FURTHER TO THE NORTH... THERE WILL LIKELY BE A SHARP CUT OFF IN
SNOWFALL AMOUNTS INLAND OF THE HEAVIEST BAND. LOCATIONS NEAR THE
CANADIAN BORDER MAY NOT SEE MUCH SNOW AT ALL... AND NORTHERN COOS
COUNTY HAS BEEN DROPPED FROM THE ADVISORY AS FORECAST SNOWFALL
AMOUNTS IN THIS REGION ARE ONLY 1 TO 2 INCHES. THE NORTHERN ZONES
IN WESTERN MAINE WERE LEFT IN AS THE SOUTHERN PORTION OF THESE
ZONES STILL HAS A THREAT FOR HIGHER TOTALS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
AS LOW PRESSURE MOVES EAST... A COLD FRONT WILL PUSH SOUTHEAST
ACROSS NEW ENGLAND ON MONDAY. A VERY COLD AIR MASS HAS BEEN
LURKING BEHIND THIS FRONT... AND THIS WILL BE FELT IN FULL FORCE
BY MONDAY AFTERNOON. TEMPERATURES WILL LIKELY BE FALLING THROUGH
THE DAY AS COLD ADVECTION TAKES OVER. WINDS COULD GUST TO 25 MPH
AS COLD ADVECTION ALLOWS GOOD MIXING TO TAKE PLACE.
TEMPERATURES FALL TO NEAR OR BELOW ZERO ACROSS THE ENTIRE FORECAST
AREA MONDAY NIGHT. READINGS AS COLD AS 20 BELOW ARE POSSIBLE TO
THE NORTH OF THE MOUNTAINS WHERE COLD AIR WILL BE EVEN MORE
INTENSE. WIND CHILL ADVISORIES OR WARNINGS MAY BE NEEDED AS WIND
CHILLS COULD REACH 30 BELOW.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
MODELS IN AGREEMENT THROUGH THE PERIOD FOR A COLD WEEK. A WEAK SHORT
WAVE WILL MOVE THROUGH NEW HAMPSHIRE AND MAINE TUESDAY AFTERNOON
WITH ASSOCIATED SNOW SHOWERS AND USHER IN EVEN COLDER AIR. WIND
CHILL ADVISORIES MAY BE NEEDED TUESDAY NIGHT AND WEDNESDAY. HIGH
PRESSURE CRESTS OVERHEAD WEDNESDAY. LATE IN THE DAY CLOUDS STREAM
EAST. LIGHT SNOW DEVELOPS THURSDAY AS LOW PRESSURE DEVELOPS SOUTH
OF LONG ISLAND NEW YORK. GFS AND ECMWF SIMILAR IN THE TRACK AND
LINGER SNOW INTO FRIDAY. SEVERAL INCHES OF SNOW POSSIBLE WITH THIS
SYSTEM. ANOTHER ARCTIC SHOT OF AIR ARRIVES FRIDAY AFTERNOON AND
SATURDAY. A WARM FRONT WILL MOVE NORTH SUNDAY.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH THURSDAY NIGHT/...VARIABLE CONDITIONS BUT
MOSTLY LIFR THIS EVE...IMPROVE FROM SW TO NE AROUND MIDNIGHT AS
PRCP COMES TO AN END FAIRLY QUICKLY FROM THIS FAST MOVING SYSTEM.
PRCP TYPE WILL BE PROBLEMATIC WITH MIXED WINTRY PRCP EXPECTED
ALONG WITH PRCP CHANGING FROM RAIN OR MIXED TO MIXED OR SNOW
BEFORE ENDING. IMPROVING TO VFR EXCEPT MVFR N/MT ZONES LATER TNGT
AND MONDAY. GUSTY NW WINDS PSBL MONDAY. VFR MONDAY NGT.
LONG TERM...POSSIBLE MVFR IN SNOW SHOWERS TUESDAY AND WEDNESDAY.
IFR MOVES IN THURSDAY AFTERNOON AND MOVES OUT FRIDAY. VFR
SATURDAY AND SUNDAY.
&&
.MARINE...
SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...UPDATED TO INPUT
LATEST OBSERVED DATA. WILL CONT HEADLINES...BUT MAY BE TOUGH TO
SEE GALE FORCE WINDS WITH THIS EVENT. STILL SOME GUSTS UP TO 35 KT
PSBL SO WON`T BACK OFF AT THIS TIME.
PREVIOUS DISCUSSION...
LOW PRESSURE MOVING FROM CAPE COD TO NOVA SCOTIA WILL BRING A
BRIEF PERIOD OF NORTHEAST WINDS WHICH COULD GUST TO GALE FORCE.
WINDS SHIFT TO NORTHWEST BY MORNING. A COLD FRONT PUSHING THROUGH
THE GULF OF MAINE ON MONDAY WILL BRING STRONG COLD ADVECTION AND
THE POTENTIAL FOR MORE GALE FORCE GUSTS THROUGH MONDAY EVENING.
LONG TERM...SMALL CRAFT WINDS TUESDAY AND WEDNESDAY. GALE FORCE
WINDS POSSIBLE THURSDAY AFTERNOON INTO SATURDAY MORNING.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MEZ012>014-
018>022-024>028.
WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR MEZ007>009-
023.
NH...WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR NHZ004>010.
WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR NHZ002-003.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NHZ013.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EST MONDAY FOR ANZ151-153.
GALE WARNING UNTIL 9 PM EST MONDAY FOR ANZ150-152-154.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
813 PM EST SUN DEC 29 2013
.SYNOPSIS...
TONIGHTS COLD FRONT PASSAGE WILL USHER IN BELOW AVERAGE TEMPERATURES
FOR THE COMING WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
MID EVE UPDATE WAS ISSUED TO ADJUST HOURLY TEMP AND WEA TRENDS
BASED ON OBS...RADAR...AND THE LATEST HRRR AND RAP MDL TRENDS. IN
GENL...HAVE DIMINISHED POPS TO CHC CATEGORY OUTSIDE OF THE RIDGE
ZONES...AND TRANSITIONED TO SCATTERED...ALBEIT SHALLOW...SNOW
SHOWER SCENARIO WITH ENCROACHMENT OF THE FRONT.
ANY SNW SHWRS ARE EXPD TO GRDLY END MON AS LLVL RIDGING BLDS. GIVEN
THE STRENGTH OF THE INCOMING COLD SURGE...LITTLE RECOVERY IS EXPECTED
WITH MONDAY TEMPS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
A SHRTWV TROF WILL CROSS THE GRTLKS MON NGT. LOW- TO MID-LVL SWLY
FLOW WILL PROVIDE MODEST WARM AIR AND MSTR ADVCTN...LEADING TO A
BRIEF PD OF DP SATURATION THRU THE DENDRITIC GROWTH LYR. THUS... A
QUICK SHOT OF LGT SNOW WILL BE PSBL LATE MON NGT-TUE MRNG AS THIS
WAVE CROSSES THE RGN. BEST CHCS WILL BE ACRS THE NRN TWO-THIRDS OF
THE FCST AREA.
SGFNT RDG NOT XPCD BEHIND THIS WAVE AS A MORE POTENT AND BROAD
TROF DVLPS IN THE CNTRL CONUS. AS SFC LOPRES STRENGTHENS IN THE
MIDWESTERN STATES...FRONTOGENESIS XPCD TO OCCUR ALONG THE SRN
GRTLKS INTO WRN PA. WARM AIR ADVCTN AND FRONTOGENESIS SHOULD BE
SUFFICIENT TO SUPPORT A BAND OF SNOW FROM PBZ FCST AREA WWD. ANY
ACCUMS ON WED WILL BE LGT OWING TO LOW-LVL DRY AIR AND APPARENT
LACK OF DYNAMICAL FORCING FOR ASCENT.
BAND OF SNOW XPCD TO SHARPEN WED NGT WITH APRCH OF SFC LOPRES AND
INCRG FRONTOGENESIS AND UPR JET ARRIVAL CONTRIBUTING TO STRONGER
UPWD MOTION. TEMPS WED NGT SHOULD SUPPORT SNOW. KRAMAR
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A COUPLE CHGS WERE MADE TO THE EXTENDED ON THU AND FRI. ON THU...
SFC LOPRES XPCD TO PASS ACRS SRN PORTION OF FCST AREA...WITH
STRONG FRONTOGENESIS XPCD ALONG ARCTIC AMS BNDRY. IN COMBINATION
WITH APRCHG H5 TROF...SUFFICIENT LIFT AND DP SATURATION LKLY WILL
YIELD SNOW OR RAIN/SNOW MIX FOR MOST OF THE FCST AREA. EXACT
TIMING IS UNCERTAIN ATTM...BUT AN INCR IN POPS WAS WARRANTED.
ARCTIC AMS WILL INVADE MUCH OF FCST AREA BY THU NGT. WITH FCSTD H9
TEMPS OF 15-20C BLW ZERO IN BOTH GFS AND ECMWF AND SUPPORTED BY
NAEFS...IT IS VERY DIFFICULT TO SEE HOW MAXIMA WILL RISE OUT OF
THE TEENS. MAXIMA WERE LWRD ON FRI TO REFLECT THIS FCST. PREV
DISCUSSION FOLLOWS... KRAMAR
STILL LOTS TO BE WORKED OUT WITH MODEL SOLUTIONS CONCERNING AN
OVERRUNNING SETUP BY THE MIDDLE OF NEXT WEEK. TEMPS WILL REMAIN
BELOW NORMAL THROUGH THE PERIOD...WITH THE COLDEST AIR EXPECTED BY
THE END OF THE LONG TERM.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
WIDESPREAD IFR CONDITIONS WILL LIKELY PARTIALLY SCATTER OUT TO
MVFR FOR A PERIOD EARLY IN THE FORECAST AS DEEP MOISTURE DEPARTS
TO THE EAST AND THE AREA SITS IN A BRIEF LULL BEFORE THE ARRIVAL
OF THE ARCTIC COLD FRONT. SHALLOW MOISTURE WITH THE ARCTICE
FRONTAL AND INEQUAL COOLING WILL LIKELY NOT ALLOW THE MOISTURE
SURFACE LAYER TO COOL ENOUGH TO GENERATE SNOW FLAKES AS THE ARCTIC
COLD FRONT LIFT PUSHES TO THE SOUTHEAST LATE THIS EVENING. AS A
RESULT...POORLY FORMED SNOW GRAINS OR FREEZING DRIZZLE WILL BE
POSSIBLE IN ASSOCIATION WITH FRONTAL LIFT BEFORE DEEPER/DRIER ARCTIC
AIR ARRIVES OVERNIGHT ALLOWING FOR SCATTERED SNOW FLURRIES AND
SLIGHTLY IMPROVING CIG/VIS OVERNIGHT THROUGH MONDAY. FRIES
.OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
PERIODIC RSTRNS ARE EXPD THRU LT WK AS SVRL DISTURBANCES CROSS THE
RGN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15/31
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
621 PM EST SUN DEC 29 2013
.SYNOPSIS...
TONIGHTS COLD FRONT PASSAGE WILL USHER IN BELOW AVERAGE TEMPERATURES
FOR THE COMING WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
EARLY EVE UPDATE WAS ISSUED TO ADJUST HOURLY TEMP AND WEA TRENDS
BASED ON OBS AND THE LATEST HRRR AND RAP MDL TRENDS.
PREVIOUS...
LOW PRES WL CONT TO MOVE OFF THE MID-ATLANTIC COAST THIS
EVE...ENDING THE STEADY RAIN. 850MB TEMPS HAVE COOLED ESP WELL N
OF PIT...AND SOME SNW COULD BRIEFLY MIX IN BEFORE THE PCPN ENDS.
COULD SEE A PD OF DRIZZLE OR LGT RAIN THIS EVE AS DEEP MOISTURE
EXITS.
A CDFNT WL MOVE THRU THE GT LKS/OH VLY RNG OVRNGT. THIS SHOULD
ALLOW FOR ENOUGH MOISTURE IN THE SNOW GROWTH RGN FOR ANY DRIZZLE
TO CHG TO SNW SHWRS AS THE FNT PASSES...PRECLUDING ANY MENTION OF
FREEZING DRIZZLE AS TEMPS FALL. SHOULD SEE UPSLOPE AND LK ENHANCED
SNW SHWRS DVLP AFT FROPA...BUT WITH LMTD MOISTURE DEPTH AND LWRG
TEMP INVERSIONS...SGFNT SNW ACCUMS ARE NOT EXPD. ANY SNW SHWRS ARE
EXPD TO GRDLY END MON AS LLVL RIDGING BLDS IN. TEMPS WL DROP IN
COLD AIR ADVCTN LTR TNGT...WITH LTL RECOVERY ON MON.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
A SHRTWV TROF WILL CROSS THE GRTLKS MON NGT. LOW- TO MID-LVL SWLY
FLOW WILL PROVIDE MODEST WARM AIR AND MSTR ADVCTN...LEADING TO A
BRIEF PD OF DP SATURATION THRU THE DENDRITIC GROWTH LYR. THUS... A
QUICK SHOT OF LGT SNOW WILL BE PSBL LATE MON NGT-TUE MRNG AS THIS
WAVE CROSSES THE RGN. BEST CHCS WILL BE ACRS THE NRN TWO-THIRDS OF
THE FCST AREA.
SGFNT RDG NOT XPCD BEHIND THIS WAVE AS A MORE POTENT AND BROAD
TROF DVLPS IN THE CNTRL CONUS. AS SFC LOPRES STRENGTHENS IN THE
MIDWESTERN STATES...FRONTOGENESIS XPCD TO OCCUR ALONG THE SRN
GRTLKS INTO WRN PA. WARM AIR ADVCTN AND FRONTOGENESIS SHOULD BE
SUFFICIENT TO SUPPORT A BAND OF SNOW FROM PBZ FCST AREA WWD. ANY
ACCUMS ON WED WILL BE LGT OWING TO LOW-LVL DRY AIR AND APPARENT
LACK OF DYNAMICAL FORCING FOR ASCENT.
BAND OF SNOW XPCD TO SHARPEN WED NGT WITH APRCH OF SFC LOPRES AND
INCRG FRONTOGENESIS AND UPR JET ARRIVAL CONTRIBUTING TO STRONGER
UPWD MOTION. TEMPS WED NGT SHOULD SUPPORT SNOW. KRAMAR
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A COUPLE CHGS WERE MADE TO THE EXTENDED ON THU AND FRI. ON THU...
SFC LOPRES XPCD TO PASS ACRS SRN PORTION OF FCST AREA...WITH
STRONG FRONTOGENESIS XPCD ALONG ARCTIC AMS BNDRY. IN COMBINATION
WITH APRCHG H5 TROF...SUFFICIENT LIFT AND DP SATURATION LKLY WILL
YIELD SNOW OR RAIN/SNOW MIX FOR MOST OF THE FCST AREA. EXACT
TIMING IS UNCERTAIN ATTM...BUT AN INCR IN POPS WAS WARRANTED.
ARCTIC AMS WILL INVADE MUCH OF FCST AREA BY THU NGT. WITH FCSTD H9
TEMPS OF 15-20C BLW ZERO IN BOTH GFS AND ECMWF AND SUPPORTED BY
NAEFS...IT IS VERY DIFFICULT TO SEE HOW MAXIMA WILL RISE OUT OF
THE TEENS. MAXIMA WERE LWRD ON FRI TO REFLECT THIS FCST. PREV
DISCUSSION FOLLOWS... KRAMAR
STILL LOTS TO BE WORKED OUT WITH MODEL SOLUTIONS CONCERNING AN
OVERRUNNING SETUP BY THE MIDDLE OF NEXT WEEK. TEMPS WILL REMAIN
BELOW NORMAL THROUGH THE PERIOD...WITH THE COLDEST AIR EXPECTED BY
THE END OF THE LONG TERM.
&&
.AVIATION /23Z SUNDAY THROUGH FRIDAY/...
WIDESPREAD IFR CONDITIONS WILL LIKELY PARTIALLY SCATTER OUT TO
MVFR FOR A PERIOD EARLY IN THE FORECAST AS DEEP MOISTURE DEPARTS
TO THE EAST AND THE AREA SITS IN A BRIEF LULL BEFORE THE ARRIVAL
OF THE ARCTIC COLD FRONT. SHALLOW MOISTURE WITH THE ARCTICE
FRONTAL AND INEQUAL COOLING WILL LIKELY NOT ALLOW THE MOISTURE
SURFACE LAYER TO COOL ENOUGH TO GENERATE SNOW FLAKES AS THE ARCTIC
COLD FRONT LIFT PUSHES TO THE SOUTHEAST LATE THIS EVENING. AS A
RESULT...POORLY FORMED SNOW GRAINS OR FREEZING DRIZZLE WILL BE
POSSIBLE IN ASSOCIATION WITH FRONTAL LIFT BEFORE DEEPER/DRIER ARCTIC
AIR ARRIVES OVERNIGHT ALLOWING FOR SCATTERED SNOW FLURRIES AND
SLIGHTLY IMPROVING CIG/VIS OVERNIGHT THROUGH MONDAY. FRIES
.OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
PERIODIC RSTRNS ARE EXPD THRU LT WK AS SVRL DISTURBANCES CROSS THE
RGN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
711 PM EST SUN DEC 29 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 424 PM EST SUN DEC 29 2013
ARCTIC AIR AND CONTINUED LAKE EFFECT OFF LAKE SUPERIOR WILL BE THE
MAIN CONCERNS FOR THE SHORT TERM PERIOD.
THE SURFACE LOW THAT BROUGHT THE SURGE OF COLD AIR CONTINUES TO
SLIDE EAST OF THE AREA...WHILE HIGH PRESSURE HAS BUILT INTO THE
NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY. THE EXITING LOW HAS
LEFT A SURFACE TROUGH OVER EASTERN LAKE SUPERIOR. ALOFT...AREA IS
UNDER AN UPPER TROUGH THAT COVERS MUCH OF THE EASTERN CONUS AND HAS
LED TO ARCTIC AIR SPILLING SOUTHEAST OVER THE UPPER GREAT LAKES LAST
NIGHT. THIS COLD AIR HAS BEEN PRODUCING LAKE EFFECT SNOW SHOWERS IN
THE NORTH-NORTHWEST WIND LOCATIONS TODAY. LATEST RADAR/SATELLITE
DATA INDICATES THE BEST BANDS OVER FAR EASTERN MARQUETTE COUNTY
AND ALGER COUNTIES...WHERE RADAR RETURNS HAVE BEEN REACHING
7KFT. HAVE STARTED SEEING THE LOW LEVEL WINDS BACKING ASSOCIATED
WITH THE HIGH PRESSURE RIDGE OVER THE LAST FEW HOURS...ESPECIALLY
OVER THE WESTERN LAKE...AND THAT HAS STARTED TO PUSH THE BANDS OVER
MARQUETTE COUNTY EASTWARD. WITH AT LEAST HALF OF THE CLOUD BEING
ABOVE THE DGZ BASED ON RAP INITIAL SOUNDINGS...CALLS TO SPOTTERS
HAS INDICATED JUST A COUPLE INCHES OF ADDITIONAL SNOW
ACCUMULATION TODAY. THE BIGGEST ISSUE HAS BEEN THE SMALL FLAKES
REDUCING VISIBILITIES...ALONG WITH GUSTY WINDS TO 30-35MPH EAST
OF MARQUETTE...AND CAUSING BRIEF WHITEOUTS ALONG M-28 IN ALGER
COUNTY. A CALL TO THE ALGER COUNTY SHERIFF INDICATED SEVERAL
ACCIDENTS ON THAT STRETCH...WITH THEM ENCOURAGING TRAVEL ALONG
M-94 INSTEAD.
WITH THE COLD AIR IN PLACE AND SOME LOW LEVEL MOISTURE...EXPECT THE
LAKE EFFECT TO CONTINUE THROUGH THE SHORT TERM PERIOD. THE
LOCATION OF THE SNOW WILL BE DETERMINED BY BOUNDARY LAYER WINDS.
SINCE THE HIGH OVER SOUTHEAST SOUTH DAKOTA WILL DRIFT TO THE
SOUTHEAST THROUGH THE NIGHT...IT WILL PUSH A RIDGE INTO THE
SOUTHWEST HALF OF UPPER MICHIGAN. THIS RIDGE WILL DO TWO
THINGS...BACK THE WINDS TO MORE OF A WEST-NORTHWEST DIRECTION AND
CONTINUE TO PROVIDE DRY AIR AND SUBSIDENCE ABOVE 850MB. THOSE
BACKING WINDS WILL ALSO BE AIDED BY A SHORTWAVE DEPARTING THE
CANADIAN ROCKIES AND MOVING INTO THE NORTHERN PLAINS ON
MONDAY. THIS WILL LEAD TO WINDS TRANSITIONING FROM THE
NORTH-NORTHWEST LATE THIS AFTERNOON TO THE NORTHWEST THIS EVENING
AND EVENTUALLY NEARLY WESTERLY BY 18Z MONDAY. THEREFORE...WOULD
EXPECT THE PURE LAKE EFFECT BANDS (NO SHORTWAVE HELP) TO FOLLOW
SUIT. 850MB TEMPS WILL REMAIN FAIRLY STEADY THROUGH MONDAY AND
AROUND -23C...LEADING TO DELTA-T VALUES AROUND THE MID 20S. BUT
THIS COLD AIR WILL LEAD TO MUCH OF THE CLOUD BEING AT THE HIGH END
OF THE DGZ OR ABOVE IT...SO WOULD EXPECT SNOW RATIOS TO BE ON THE
LOWER END FOR LAKE EFFECT AND IN MOST SITUATIONS BELOW 20 TO 1. IN
THE STRONGEST BANDS OVER THE EAST AND THE BETTER LAKE
MODIFICATION...DID KEEP SOME LOW 20S IN THE FORECAST. AS SEEN ON
SATELLITE NEAR IRONWOOD THIS AFTERNOON...THE STRONGEST BANDS
WILL BE ON THE SOUTHWEST EDGE OF THE LES DUE TO THE ENHANCED
CONVERGENCE FROM THE BACKING WINDS. ALTHOUGH THIS WILL STRENGTHEN
THE BANDS...THINK THE CONSISTENT BACKING FLOW (ALONG WITH THE LOWER
RATIOS) WILL BE ENOUGH TO KEEP AMOUNTS GENERALLY LIGHT. HAVE KEPT
AMOUNTS FAIRLY SIMILAR TO WHAT WAS SEEN DURING THE DAY TODAY IN THE
LES LOCATIONS (1-2.5IN)...BUT DO HAVE SLIGHTLY HIGHER AMOUNTS
(APPROACHING 4) OVER THE EAST WITH THE SLOWER BACKING TREND. THE
LONGER FETCH WITH THE WEST TO WEST-SOUTHWEST WINDS OVER WESTERN
LAKE SUPERIOR COULD LEAD TO AN INCREASE IN INTENSITY OF THE MAIN
LAKE EFFECT BAND OVER THE KEWEENAW PENINSULA (NORTH OF HOUGHTON).
LAKE INDUCED EQUILIBRIUM LEVELS STILL AROUND 7KFT AND MUCH OF THE
CLOUDS IS AT HIGH END OF DGZ OR ABOVE SO WON/T GO TOO HIGH ON
AMOUNTS IN THE LATE MORNING AND INTO THE AFTERNOON...BUT COULD NEAR
LOW END ADVISORY AMOUNTS.
AS FOR SNOW HEADLINES...CANCELLED BARAGA AND SOUTHERN HOUGHTON
EARLY AND WILL ALLOW THE REST OF THE WESTERN AREAS EXPIRE AT 00Z AS
WINDS WILL DIMINISH AND JUST LIGHT SNOW WILL REMAIN. OVER THE
EAST...HAVE KEPT THEM AS IS WITH THE BAD CONDITIONS REPORTED ALONG
M-28 IN ALGER COUNTY...ALTHOUGH MOST LOCATIONS TONIGHT WILL
STRUGGLE TO REACH THE 4 INCH IN 12HR AMOUNTS DUE TO THE SMALLER
FLAKES.
AS FOR THE WIND CHILL HEADLINES...CLOUDS WILL DETERMINE THE LOWS
TONIGHT. UNFORTUNATELY IT COMES DOWN TO THE DIMINISHING LAKE
EFFECT CLOUDS OVER THE WEST AND THEN HIGH CLOUDS STREAMING IN LATE
TONIGHT AHEAD OF THE NEXT WAVE IN THE UPPER TROUGH SLIDING SOUTHEAST
THROUGH THE NORTHERN PLAINS. 12Z GFS/ECMWF ARE THE MOST AGGRESSIVE
WITH THESE HIGH CLOUD...COVERING THE WESTERN HALF OF THE CWA BY
12Z. WITH THE COLD AIR IN PLACE...THINK THAT TEMPS WILL COOL
FAIRLY QUICKLY IN AREAS THAT SKIES CLEAR. THE REGIONAL
GEM...WHICH TRADITIONALLY DOES WELL IN THESE CASES ONLY HAS LOWS
IN THE LOW TEENS BELOW ZERO ALONG THE WISCONSIN BORDER AND SINGLE
DIGITS ELSEWHERE. THIS PROVIDES SOME CONCERN TO THE GOING FORECAST
AND TWEAKED VALUES SLIGHTLY HIGHER. ON THE OTHER SIDE...18Z HRRR/RAP
FORECASTS HAVE LOWS AROUND -20 TO -23 TONIGHT...BUT IN MOST
SITUATIONS THEY ARE TOO LOW. EVEN WITH THE SLIGHT TWEAKS...WIND
CHILL ADVISORY LOOKS GOOD FOR AREAS NEAR THE WISCONSIN BORDER AND
HAVE LEFT IT AS IS. A LITTLE CONCERNED ON LAKE CLOUDS LINGERING
OVER MARQUETTE/BARAGA...BUT LOCATIONS WELL INLAND SHOULD CLEAR OUT
LATE AND ALLOW FOR TEMPS TO FALL. FINALLY...MAY NEED TO MONITOR
MENOMINEE COUNTY...AS GOING FORECAST HAS WIND CHILLS NEARING -25
OVER THE WESTERN REACHES OF THE COUNTY.
THE PREVIOUSLY MENTIONED MID/HIGH CLOUDS WILL MOVE ACROSS THE REST
OF THE CWA DURING THE DAY ON MONDAY AND LEAD TO A FILTERED SUNSHINE
AWAY FROM THE LAKE EFFECT. THERE COULD EVEN BE A FEW SNOW SHOWERS
NEAR IRONWOOD LATE MONDAY AFTERNOON ON THE NORTH EDGE OF THE WAVE
MOVING INTO WISCONSIN ON MONDAY EVENING. HIGHS ON MONDAY WILL BE
15-20 DEGREES BELOW NORMAL AND IN THE SINGLE DIGITS ABOVE ZERO FOR
MOST LOCATIONS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 425 PM EST SUN DEC 29 2013
BIGGEST CONCERNS IN THE EXTENDED FOCUS ON THE POTENTIAL FOR HEAVY
LAKE EFFECT SNOW OVER THE NE CWA MON NIGHT INTO TUESDAY AND ALSO
ADVISORY LEVEL WIND CHILLS FOR SOME AREAS INTO MIDWEEK.
MON NIGHT INTO TUE...AS THE POLAR VORTEX SLOWLY SHIFTS SE FROM
HUDSON BAY...THE MODELS SUGGEST A SHORTWAVE TROUGH WILL MOVE THROUGH
THE UPPER MS VALLEY TOWARD THE UPPER GREAT LAKES. THE BEST ISENTROPIC
LIFT NEAR THE 850 MB FRONT AND POTENTIAL FOR WIDESPREAD LIGHT SNOW
IS EXPECTED TO REMAIN TO THE SOUTH OF UPPER MI. AS THE LOW LEVEL
WINDS BACK W OR WSW AHEAD OF THE SHRTWV ON MONDAY...THE LES OVER THE
NE CWA WILL GRADUALLY LIFT TO THE NORTH AND POSSIBLY MOVE OFFSHORE
BY LATE IN THE DAY. VEERING WINDS IN THE WAKE OF THE SHRTWV WILL
PUSH THE LES BACK INTO AREAS FAVORED BY NW FLOW BY LATE EVENING.
LAKE INDUCED TROUGHING IS EXPECTED TO FOCUS THE STRONGEST LOW LEVEL
CONV BACK INTO THE NE PORTION OF THE CWA FROM P53 EASTWARD. NAM FCST
SOUNDINGS ALSO INDICATE THAT THE DGZ WILL BE MORE FAVORABLY PLACED
IN THE CONVECTIVE LAYER TO BOOST SLR VALUES AND OVERALL SNOWFALL
POTENTIAL. USING A BLEND OF THE NAM AND LOCAL WRF-ARW QPF WITH
LIKELY CONSERVATIVE SLR VALUES AROUND 20/1...CAME UP WITH TOTAL
SNOWFALL ACCUMULATION EXCEEDING A FOOT OVER ERN ALGER AND NRN LUCE
COUNTIES FOR THE MON NIGHT THROUGH TUE TIME FRAME. THUS...HAVE
DECIDED TO ISSUE A LAKE EFFECT SNOW WATCH FOR ALGER AND LUCE
COUNTIES OVER THIS TIME FRAME. NRN SCHOOLCRAFT WILL LIKELY SEE
PERIODS OF HEAVY LES AS WELL...BUT LOW-LVL CONVERGENCE WILL NOT BE
AS PERSISTENT THERE SO WILL KEEP THEM OUT OF THE WATCH...BUT FEEL
PRETTY CERTAIN THEY WILL EVENTUALLY NEED AN LES ADVISORY.
EVEN THOUGH TEMPS MAY NOT BE AS COLD EARLY TUE...SLIGHTLY STRONGER
WINDS IN THE WAKE OF THE SHORTWAVE WILL AGAIN PUSH WIND CHILLS INTO
THE -25 TO -35 ADVISORY RANGE OVER THE WEST.
WED INTO THU...THE NEXT SIGNIFICANT SHORTWAVE TROUGH IS EXPECTED TO
REMAIN WELL TO THE SOUTH BRINGING SNOW TO MAINLY IA/NRN IL/SRN WI
AND THE SOUTHERN GREAT LAKES. GREAT LAKES AGGREGATE TROUGHING WILL
INFLUENCE GENERALLY LIGHT LOW LEVEL WIND FIELDS AND THE RESULTING LES
INTO UPPER MI AS 850 MB TEMPS REMAIN IN THE -22C TO -26C RANGE. IT
APPEARS NOW THE MAIN FOCUS FOR LES ACCUMULATIONS MAY BE OVER THE
WEST AND NCNTRL PORTIONS OF THE CWA AS A N-NE FLOW IS EXPECTED TO
DEVELOP WED NIGHT INTO THU ON THE BACKSIDE OF SFC LOW PASSING SOUTH
AND THEN EAST OF THE REGION. WITH MODEL SNDGS SHOWING COMPRESSION OF
THE DGZ WITHIN THE LOWEST 2KFT OF THE ATMOSPHERE ALONG WITH
INVERSION HGTS AROUND 5 KFT...THE EXPECTED SMALLER FLAKE SIZE SHOULD
GENERALLY KEEP ACCUMULATION LIGHT FOR THE MOST PART.
FRI-SUN...MODELS WERE IN GENERAL AGREEMENT WITH TREND TOWARD A LESS
AMPLIFIED PATTERN. AS SFC HIGH PRESSURE SLIDES EAST LATE IN THE
WEEK...THE ECMWF AND GFS DEVELOP AREA OF LIGHT SNOW IN REGION OF
WAA/ISENTROPIC ASCENT AHEAD OF A SHRTWV MOVING THROUGH NW ONTARIO.
THIS SNOW LOOKS TO SPREAD INTO UPPER MI LATE FRI INTO SAT MORNING
WITH ANOTHER BAND OF SYNOPTIC SNOW ALONG COLD FRONTAL PASSAGE SAT
AFTERNOON/SAT NIGHT. EXPECT LES TO DEVELOP LATE SATURDAY NIGHT INTO
SUNDAY WITH INCREASING CAA IN NNW FLOW IN THE WAKE OF THE COLD
FRONT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 624 PM EST SUN DEC 29 2013
IWD...AS THE LLVL FLOW BACKS SLOWLY TOWARD THE WSW THRU THE NGT...
EXPECT LES IMPACTING THIS LOCATION TO SHIFT TO THE N...WITH A TREND
TOWARD PREDOMINANT VFR WX. ALTHOUGH SOME LGT SN IN ADVANCE OF
ANOTHER DISTURBANCE MAY ARRIVE LATE MON AFTN...CONDITIONS ARE LIKELY
TO REMAIN VFR AS THIS SYS WL BE MSTR DEPRIVED AND THE SHARPER
DYNAMICS WL REMAIN TO THE S.
CMX...ALTHOUGH LES WL CONT THRU THE NGT AT THIS SITE...DIMINISHING
WINDS/BLSN THIS EVNG WL RESULT IN A SLOW IMPROVEMENT IN VSBY TO
PREDOMINANT MVFR. SOME HEAVIER SHSN/IFR CONDITIONS ARE LIKELY TO
RETURN LATER TNGT WITH SHARPER LLVL CNVGC ASSOCIATED WITH THE
BACKING LLVL FLOW SUPPORTING SOME HEAVIER LES. AFTER THESE BANDS
SHIFT TO THE N OF CMX ON MON...MVFR CONDITIONS WL PREDOMINATE UNTIL
THE APRCH OF ANOTHER DISTURBNANCE BRINGS MORE SN AND IFR VSBYS LATER
IN THE AFTN.
SAW...WITH A DOWNSLOPE NW FLOW BACKING WSW...EXPECT VFR CONDITIONS
TO DOMINATE THIS LOCATION THE ENTIRE FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 424 PM EST SUN DEC 29 2013
NORTHWESTERLY WINDS OF 15 TO 25 KNOTS WILL CONTINUE INTO THIS
EVENING BEFORE BACKING TO THE WEST-NORTHWEST LATE TONIGHT INTO
MONDAY. WINDS WILL WEAKEN SLIGHTLY AS THIS OCCURS AND SLOWLY
DIMINISH THE POTENTIAL FOR FREEZING SPRAY OVER THE LAKE BY MONDAY
AFTERNOON. AS THE LINGERING SURFACE TROUGH OVER EASTERN LAKE
SUPERIOR STRENGTHENS ON MONDAY NIGHT AND SHIFTS EAST ON
TUESDAY...NORTHWESTERLY WINDS WILL INCREASE WITH SOME GUSTS TO 30KTS
OVER THE EASTERN LAKE TUESDAY AFTERNOON AND EVENING. THIS WILL ALSO
BRING AN INCREASED OPPORTUNITY FOR HEAVY FREEZING SPRAY THROUGH
TUESDAY NIGHT OVER THE EASTERN HALF OF LAKE SUPERIOR. ALTHOUGH
THERE STILL WILL BE A LINGERING TROUGH OVER EASTERN LAKE SUPERIOR
INTO WEDNESDAY...HIGH PRESSURE BUILDING OVER THE UPPER MISSISSIPPI
VALLEY WILL LEAD TO LIGHTER NORTHWESTERLY WINDS FOR WEDNESDAY AND
THURSDAY...BRINGING AN END TO THE POTENTIAL FOR HEAVY FREEZING
SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY FROM MIDNIGHT EST /11 PM CST/ TONIGHT TO 10
AM EST /9 AM CST/ MONDAY FOR MIZ011-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST MONDAY FOR MIZ085.
WIND CHILL ADVISORY UNTIL 10 AM EST /9 AM CST/ MONDAY FOR MIZ002-
009-010.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST MONDAY FOR MIZ006-007.
LAKE EFFECT SNOW WATCH FROM MONDAY EVENING THROUGH TUESDAY
EVENING FOR MIZ006-007.
WIND CHILL ADVISORY FROM 4 AM TO 10 AM EST MONDAY FOR MIZ004-005.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR LSZ266.
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST MONDAY FOR LSZ265.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST MONDAY FOR
LSZ248>251-264.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST /MIDNIGHT CST/
MONDAY FOR LSZ240>245-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...VOSS
AVIATION...KC
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
626 PM EST SUN DEC 29 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 424 PM EST SUN DEC 29 2013
ARCTIC AIR AND CONTINUED LAKE EFFECT OFF LAKE SUPERIOR WILL BE THE
MAIN CONCERNS FOR THE SHORT TERM PERIOD.
THE SURFACE LOW THAT BROUGHT THE SURGE OF COLD AIR CONTINUES TO
SLIDE EAST OF THE AREA...WHILE HIGH PRESSURE HAS BUILT INTO THE
NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY. THE EXITING LOW HAS
LEFT A SURFACE TROUGH OVER EASTERN LAKE SUPERIOR. ALOFT...AREA IS
UNDER AN UPPER TROUGH THAT COVERS MUCH OF THE EASTERN CONUS AND HAS
LED TO ARCTIC AIR SPILLING SOUTHEAST OVER THE UPPER GREAT LAKES LAST
NIGHT. THIS COLD AIR HAS BEEN PRODUCING LAKE EFFECT SNOW SHOWERS IN
THE NORTH-NORTHWEST WIND LOCATIONS TODAY. LATEST RADAR/SATELLITE
DATA INDICATES THE BEST BANDS OVER FAR EASTERN MARQUETTE COUNTY
AND ALGER COUNTIES...WHERE RADAR RETURNS HAVE BEEN REACHING
7KFT. HAVE STARTED SEEING THE LOW LEVEL WINDS BACKING ASSOCIATED
WITH THE HIGH PRESSURE RIDGE OVER THE LAST FEW HOURS...ESPECIALLY
OVER THE WESTERN LAKE...AND THAT HAS STARTED TO PUSH THE BANDS OVER
MARQUETTE COUNTY EASTWARD. WITH AT LEAST HALF OF THE CLOUD BEING
ABOVE THE DGZ BASED ON RAP INITIAL SOUNDINGS...CALLS TO SPOTTERS
HAS INDICATED JUST A COUPLE INCHES OF ADDITIONAL SNOW
ACCUMULATION TODAY. THE BIGGEST ISSUE HAS BEEN THE SMALL FLAKES
REDUCING VISIBILITIES...ALONG WITH GUSTY WINDS TO 30-35MPH EAST
OF MARQUETTE...AND CAUSING BRIEF WHITEOUTS ALONG M-28 IN ALGER
COUNTY. A CALL TO THE ALGER COUNTY SHERIFF INDICATED SEVERAL
ACCIDENTS ON THAT STRETCH...WITH THEM ENCOURAGING TRAVEL ALONG
M-94 INSTEAD.
WITH THE COLD AIR IN PLACE AND SOME LOW LEVEL MOISTURE...EXPECT THE
LAKE EFFECT TO CONTINUE THROUGH THE SHORT TERM PERIOD. THE
LOCATION OF THE SNOW WILL BE DETERMINED BY BOUNDARY LAYER WINDS.
SINCE THE HIGH OVER SOUTHEAST SOUTH DAKOTA WILL DRIFT TO THE
SOUTHEAST THROUGH THE NIGHT...IT WILL PUSH A RIDGE INTO THE
SOUTHWEST HALF OF UPPER MICHIGAN. THIS RIDGE WILL DO TWO
THINGS...BACK THE WINDS TO MORE OF A WEST-NORTHWEST DIRECTION AND
CONTINUE TO PROVIDE DRY AIR AND SUBSIDENCE ABOVE 850MB. THOSE
BACKING WINDS WILL ALSO BE AIDED BY A SHORTWAVE DEPARTING THE
CANADIAN ROCKIES AND MOVING INTO THE NORTHERN PLAINS ON
MONDAY. THIS WILL LEAD TO WINDS TRANSITIONING FROM THE
NORTH-NORTHWEST LATE THIS AFTERNOON TO THE NORTHWEST THIS EVENING
AND EVENTUALLY NEARLY WESTERLY BY 18Z MONDAY. THEREFORE...WOULD
EXPECT THE PURE LAKE EFFECT BANDS (NO SHORTWAVE HELP) TO FOLLOW
SUIT. 850MB TEMPS WILL REMAIN FAIRLY STEADY THROUGH MONDAY AND
AROUND -23C...LEADING TO DELTA-T VALUES AROUND THE MID 20S. BUT
THIS COLD AIR WILL LEAD TO MUCH OF THE CLOUD BEING AT THE HIGH END
OF THE DGZ OR ABOVE IT...SO WOULD EXPECT SNOW RATIOS TO BE ON THE
LOWER END FOR LAKE EFFECT AND IN MOST SITUATIONS BELOW 20 TO 1. IN
THE STRONGEST BANDS OVER THE EAST AND THE BETTER LAKE
MODIFICATION...DID KEEP SOME LOW 20S IN THE FORECAST. AS SEEN ON
SATELLITE NEAR IRONWOOD THIS AFTERNOON...THE STRONGEST BANDS
WILL BE ON THE SOUTHWEST EDGE OF THE LES DUE TO THE ENHANCED
CONVERGENCE FROM THE BACKING WINDS. ALTHOUGH THIS WILL STRENGTHEN
THE BANDS...THINK THE CONSISTENT BACKING FLOW (ALONG WITH THE LOWER
RATIOS) WILL BE ENOUGH TO KEEP AMOUNTS GENERALLY LIGHT. HAVE KEPT
AMOUNTS FAIRLY SIMILAR TO WHAT WAS SEEN DURING THE DAY TODAY IN THE
LES LOCATIONS (1-2.5IN)...BUT DO HAVE SLIGHTLY HIGHER AMOUNTS
(APPROACHING 4) OVER THE EAST WITH THE SLOWER BACKING TREND. THE
LONGER FETCH WITH THE WEST TO WEST-SOUTHWEST WINDS OVER WESTERN
LAKE SUPERIOR COULD LEAD TO AN INCREASE IN INTENSITY OF THE MAIN
LAKE EFFECT BAND OVER THE KEWEENAW PENINSULA (NORTH OF HOUGHTON).
LAKE INDUCED EQUILIBRIUM LEVELS STILL AROUND 7KFT AND MUCH OF THE
CLOUDS IS AT HIGH END OF DGZ OR ABOVE SO WON/T GO TOO HIGH ON
AMOUNTS IN THE LATE MORNING AND INTO THE AFTERNOON...BUT COULD NEAR
LOW END ADVISORY AMOUNTS.
AS FOR SNOW HEADLINES...CANCELLED BARAGA AND SOUTHERN HOUGHTON
EARLY AND WILL ALLOW THE REST OF THE WESTERN AREAS EXPIRE AT 00Z AS
WINDS WILL DIMINISH AND JUST LIGHT SNOW WILL REMAIN. OVER THE
EAST...HAVE KEPT THEM AS IS WITH THE BAD CONDITIONS REPORTED ALONG
M-28 IN ALGER COUNTY...ALTHOUGH MOST LOCATIONS TONIGHT WILL
STRUGGLE TO REACH THE 4 INCH IN 12HR AMOUNTS DUE TO THE SMALLER
FLAKES.
AS FOR THE WIND CHILL HEADLINES...CLOUDS WILL DETERMINE THE LOWS
TONIGHT. UNFORTUNATELY IT COMES DOWN TO THE DIMINISHING LAKE
EFFECT CLOUDS OVER THE WEST AND THEN HIGH CLOUDS STREAMING IN LATE
TONIGHT AHEAD OF THE NEXT WAVE IN THE UPPER TROUGH SLIDING SOUTHEAST
THROUGH THE NORTHERN PLAINS. 12Z GFS/ECMWF ARE THE MOST AGGRESSIVE
WITH THESE HIGH CLOUD...COVERING THE WESTERN HALF OF THE CWA BY
12Z. WITH THE COLD AIR IN PLACE...THINK THAT TEMPS WILL COOL
FAIRLY QUICKLY IN AREAS THAT SKIES CLEAR. THE REGIONAL
GEM...WHICH TRADITIONALLY DOES WELL IN THESE CASES ONLY HAS LOWS
IN THE LOW TEENS BELOW ZERO ALONG THE WISCONSIN BORDER AND SINGLE
DIGITS ELSEWHERE. THIS PROVIDES SOME CONCERN TO THE GOING FORECAST
AND TWEAKED VALUES SLIGHTLY HIGHER. ON THE OTHER SIDE...18Z HRRR/RAP
FORECASTS HAVE LOWS AROUND -20 TO -23 TONIGHT...BUT IN MOST
SITUATIONS THEY ARE TOO LOW. EVEN WITH THE SLIGHT TWEAKS...WIND
CHILL ADVISORY LOOKS GOOD FOR AREAS NEAR THE WISCONSIN BORDER AND
HAVE LEFT IT AS IS. A LITTLE CONCERNED ON LAKE CLOUDS LINGERING
OVER MARQUETTE/BARAGA...BUT LOCATIONS WELL INLAND SHOULD CLEAR OUT
LATE AND ALLOW FOR TEMPS TO FALL. FINALLY...MAY NEED TO MONITOR
MENOMINEE COUNTY...AS GOING FORECAST HAS WIND CHILLS NEARING -25
OVER THE WESTERN REACHES OF THE COUNTY.
THE PREVIOUSLY MENTIONED MID/HIGH CLOUDS WILL MOVE ACROSS THE REST
OF THE CWA DURING THE DAY ON MONDAY AND LEAD TO A FILTERED SUNSHINE
AWAY FROM THE LAKE EFFECT. THERE COULD EVEN BE A FEW SNOW SHOWERS
NEAR IRONWOOD LATE MONDAY AFTERNOON ON THE NORTH EDGE OF THE WAVE
MOVING INTO WISCONSIN ON MONDAY EVENING. HIGHS ON MONDAY WILL BE
15-20 DEGREES BELOW NORMAL AND IN THE SINGLE DIGITS ABOVE ZERO FOR
MOST LOCATIONS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 425 PM EST SUN DEC 29 2013
BIGGEST CONCERNS IN THE EXTENDED FOCUS ON THE POTENTIAL FOR HEAVY
LAKE EFFECT SNOW OVER THE NE CWA MON NIGHT INTO TUESDAY AND ALSO
ADVISORY LEVEL WIND CHILLS FOR SOME AREAS INTO MIDWEEK.
MON NIGHT INTO TUE...AS THE POLAR VORTEX SLOWLY SHIFTS SE FROM
HUDSON BAY...THE MODELS SUGGEST A SHORTWAVE TROUGH WILL MOVE THROUGH
THE UPPER MS VALLEY TOWARD THE UPPER GREAT LAKES. THE BEST ISENTROPIC
LIFT NEAR THE 850 MB FRONT AND POTENTIAL FOR WIDESPREAD LIGHT SNOW
IS EXPECTED TO REMAIN TO THE SOUTH OF UPPER MI. AS THE LOW LEVEL
WINDS BACK W OR WSW AHEAD OF THE SHRTWV ON MONDAY...THE LES OVER THE
NE CWA WILL GRADUALLY LIFT TO THE NORTH AND POSSIBLY MOVE OFFSHORE
BY LATE IN THE DAY. VEERING WINDS IN THE WAKE OF THE SHRTWV WILL
PUSH THE LES BACK INTO AREAS FAVORED BY NW FLOW BY LATE EVENING.
LAKE INDUCED TROUGHING IS EXPECTED TO FOCUS THE STRONGEST LOW LEVEL
CONV BACK INTO THE NE PORTION OF THE CWA FROM P53 EASTWARD. NAM FCST
SOUNDINGS ALSO INDICATE THAT THE DGZ WILL BE MORE FAVORABLY PLACED
IN THE CONVECTIVE LAYER TO BOOST SLR VALUES AND OVERALL SNOWFALL
POTENTIAL. USING A BLEND OF THE NAM AND LOCAL WRF-ARW QPF WITH
LIKELY CONSERVATIVE SLR VALUES AROUND 20/1...CAME UP WITH TOTAL
SNOWFALL ACCUMULATION EXCEEDING A FOOT OVER ERN ALGER AND NRN LUCE
COUNTIES FOR THE MON NIGHT THROUGH TUE TIME FRAME. THUS...HAVE
DECIDED TO ISSUE A LAKE EFFECT SNOW WATCH FOR ALGER AND LUCE
COUNTIES OVER THIS TIME FRAME. NRN SCHOOLCRAFT WILL LIKELY SEE
PERIODS OF HEAVY LES AS WELL...BUT LOW-LVL CONVERGENCE WILL NOT BE
AS PERSISTENT THERE SO WILL KEEP THEM OUT OF THE WATCH...BUT FEEL
PRETTY CERTAIN THEY WILL EVENTUALLY NEED AN LES ADVISORY.
EVEN THOUGH TEMPS MAY NOT BE AS COLD EARLY TUE...SLIGHTLY STRONGER
WINDS IN THE WAKE OF THE SHORTWAVE WILL AGAIN PUSH WIND CHILLS INTO
THE -25 TO -35 ADVISORY RANGE OVER THE WEST.
WED INTO THU...THE NEXT SIGNIFICANT SHORTWAVE TROUGH IS EXPECTED TO
REMAIN WELL TO THE SOUTH BRINGING SNOW TO MAINLY IA/NRN IL/SRN WI
AND THE SOUTHERN GREAT LAKES. GREAT LAKES AGGREGATE TROUGHING WILL
INFLUENCE GENERALLY LIGHT LOW LEVEL WIND FIELDS AND THE RESULTING LES
INTO UPPER MI AS 850 MB TEMPS REMAIN IN THE -22C TO -26C RANGE. IT
APPEARS NOW THE MAIN FOCUS FOR LES ACCUMULATIONS MAY BE OVER THE
WEST AND NCNTRL PORTIONS OF THE CWA AS A N-NE FLOW IS EXPECTED TO
DEVELOP WED NIGHT INTO THU ON THE BACKSIDE OF SFC LOW PASSING SOUTH
AND THEN EAST OF THE REGION. WITH MODEL SNDGS SHOWING COMPRESSION OF
THE DGZ WITHIN THE LOWEST 2KFT OF THE ATMOSPHERE ALONG WITH
INVERSION HGTS AROUND 5 KFT...THE EXPECTED SMALLER FLAKE SIZE SHOULD
GENERALLY KEEP ACCUMULATION LIGHT FOR THE MOST PART.
FRI-SUN...MODELS WERE IN GENERAL AGREEMENT WITH TREND TOWARD A LESS
AMPLIFIED PATTERN. AS SFC HIGH PRESSURE SLIDES EAST LATE IN THE
WEEK...THE ECMWF AND GFS DEVELOP AREA OF LIGHT SNOW IN REGION OF
WAA/ISENTROPIC ASCENT AHEAD OF A SHRTWV MOVING THROUGH NW ONTARIO.
THIS SNOW LOOKS TO SPREAD INTO UPPER MI LATE FRI INTO SAT MORNING
WITH ANOTHER BAND OF SYNOPTIC SNOW ALONG COLD FRONTAL PASSAGE SAT
AFTERNOON/SAT NIGHT. EXPECT LES TO DEVELOP LATE SATURDAY NIGHT INTO
SUNDAY WITH INCREASING CAA IN NNW FLOW IN THE WAKE OF THE COLD
FRONT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 624 PM EST SUN DEC 29 2013
IWD...AS THE LLVL FLOW BACKS SLOWLY TOWARD THE WSW THRU THE NGT...
EXPECT LES IMPACTING THIS LOCATION TO SHIFT TO THE N...WITH A TREND
TOWARD PREDOMINANT VFR WX. ALTHOUGH SOME LGT SN IN ADVANCE OF
ANOTHER DISTURBANCE MAY ARRIVE LATE MON AFTN...CONDITIONS ARE LIKELY
TO REMAIN VFR AS THIS SYS WL BE MSTR DEPRIVED AND THE SHARPER
DYNAMICS WL REMAIN TO THE S.
CMX...ALTHOUGH LES WL CONT THRU THE NGT AT THIS SITE...DIMINISHING
WINDS/BLSN THIS EVNG WL RESULT IN A SLOW IMPROVEMENT IN VSBY TO
PREDOMINANT MVFR. SOME HEAVIER SHSN/IFR CONDITIONS ARE LIKELY TO
RETURN LATER TNGT WITH SHARPER LLVL CNVGC ASSOCIATED WITH THE
BACKING LLVL FLOW SUPPORTING SOME HEAVIER LES. AFTER THESE BANDS
SHIFT TO THE N OF CMX ON MON...MVFR CONDITIONS WL PREDOMINATE UNTIL
THE APRCH OF ANOTHER DISTURBNANCE BRINGS MORE SN AND IFR VSBYS LATER
IN THE AFTN.
SAW...WITH A DOWNSLOPE NW FLOW BACKING WSW...EXPECT VFR CONDITIONS
TO DOMINATE THIS LOCATION THE ENTIRE FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 424 PM EST SUN DEC 29 2013
NORTHWESTERLY WINDS OF 15 TO 25 KNOTS WILL CONTINUE INTO THIS
EVENING BEFORE BACKING TO THE WEST-NORTHWEST LATE TONIGHT INTO
MONDAY. WINDS WILL WEAKEN SLIGHTLY AS THIS OCCURS AND SLOWLY
DIMINISH THE POTENTIAL FOR FREEZING SPRAY OVER THE LAKE BY MONDAY
AFTERNOON. AS THE LINGERING SURFACE TROUGH OVER EASTERN LAKE
SUPERIOR STRENGTHENS ON MONDAY NIGHT AND SHIFTS EAST ON
TUESDAY...NORTHWESTERLY WINDS WILL INCREASE WITH SOME GUSTS TO 30KTS
OVER THE EASTERN LAKE TUESDAY AFTERNOON AND EVENING. THIS WILL ALSO
BRING AN INCREASED OPPORTUNITY FOR HEAVY FREEZING SPRAY THROUGH
TUESDAY NIGHT OVER THE EASTERN HALF OF LAKE SUPERIOR. ALTHOUGH
THERE STILL WILL BE A LINGERING TROUGH OVER EASTERN LAKE SUPERIOR
INTO WEDNESDAY...HIGH PRESSURE BUILDING OVER THE UPPER MISSISSIPPI
VALLEY WILL LEAD TO LIGHTER NORTHWESTERLY WINDS FOR WEDNESDAY AND
THURSDAY...BRINGING AN END TO THE POTENTIAL FOR HEAVY FREEZING
SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY FROM MIDNIGHT EST /11 PM CST/ TONIGHT TO 10
AM EST /9 AM CST/ MONDAY FOR MIZ011-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST MONDAY FOR MIZ085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING
FOR MIZ001>003-005-009.
WIND CHILL ADVISORY UNTIL 10 AM EST /9 AM CST/ MONDAY FOR MIZ002-
009-010.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST MONDAY FOR MIZ006-007.
LAKE EFFECT SNOW WATCH FROM MONDAY EVENING THROUGH TUESDAY
EVENING FOR MIZ006-007.
WIND CHILL ADVISORY FROM 4 AM TO 10 AM EST MONDAY FOR MIZ004-005.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR LSZ266.
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST MONDAY FOR LSZ265.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST MONDAY FOR
LSZ248>251-264.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST /MIDNIGHT CST/
MONDAY FOR LSZ240>245-263.
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST /6 PM CST/ THIS
EVENING FOR LSZ162-246-247.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...VOSS
AVIATION...KC
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
446 PM EST SAT DEC 28 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 419 PM EST SAT DEC 28 2013
A STALLED FRONTAL BOUNDARY OVER SOUTHERN LAKE SUPERIOR AND NORTHERN
UPPER MICHIGAN HAS LED TO DREARY CONDITIONS FOR MUCH OF UPPER
MICHIGAN TODAY. ON THE PLUS SIDE...TEMPERATURES HAVE BEEN IN THE
LOW TO MID 30S ALONG AND SOUTH OF THE BOUNDARY WHERE THERE HAVE
EVEN BEEN A FEW PEAKS OF SUNSHINE. JUST TO THE NORTH OF THE
BOUNDARY...FAVORABLE EASTERLY FLOW OFF LAKE SUPERIOR HAS LED TO
SOME FZDZ...FOG...AND -SHSN OVER THE KEWEENAW PENINSULA. A SPOTTER
REPORT AROUND 3PM INDICATED A SLIGHT GLAZE IN MOHAWK SHORTLY
AFTER THE VISIBILITY REALLY DROPPED AT KCMX. THINK THAT
FREEZING DRIZZLE WILL REMAIN A THREAT OVER THE NEXT COUPLE OF HOURS
AND EVEN DRIFT SOUTHEAST THROUGH THE EVENING...AS MODELS SHOW A
LACK OF ICE CRYSTALS IN THE CLOUDS BEFORE THE MAIN PRECIPITATION
ARRIVES FROM SOUTHERN CANADA LATE THIS EVENING. ALSO FOR THIS
EVENING...DID ADD SOME PATCHY FOG OVER THE SOUTHEAST PART OF THE
CWA WHERE WINDS WILL BE LIGHT AND THERE HAVE BEEN SOME BREAKS IN
THE CLOUDS.
THE LOW THAT IS CURRENTLY CENTERED IN SOUTH CENTRAL MINNESOTA WILL
CONTINUE EAST TONIGHT AND SUNDAY...BEING CENTERED JUST NORTH OF LAKE
ONTARIO BY 00Z MONDAY. AS THIS LOW SWEEPS EAST...AN AREA OF SNOW
(CURRENTLY IN SOUTHWEST ONTARIO AND ALSO ENTERING NORTHWEST
MINNESOTA) WILL SWEEP ACROSS THE UPPER GREAT LAKES LATE THIS
EVENING THROUGH EARLY SUNDAY MORNING. THE SYNOPTIC SNOW WILL BE
AIDED BY THE RIGHT REAR OF THE 110KT UPPER JET THAT SWEEPS ACROSS
TONIGHT. IN ADDITION...POCKET OF 800-600MB FGEN WILL SLIDE THROUGH
WITH THE 850/700MB TROUGH. THUS...EXPECT A PERIOD OF LIGHT SNOW TO
MOVE ACROSS MUCH OF UPPER MICHIGAN FROM WEST TO EAST. WITH THE BEST
FORCING OVER THE NORTHERN HALF OF THE CWA...EXPECT THE BEST SYNOPTIC
SNOWFALL THERE...WHICH WILL BE AIDED BY LAKE ENHANCEMENT. OVER THE
SOUTHERN HALF...ONLY EXPECT A LIGHT DUSTING TO AN INCH AWAY FROM THE
LAKE SUPERIOR INFLUENCES WITH SNOW RATIOS AROUND NORMAL VALUES OF
13-1.
AS FOR THE LAKE ENHANCEMENT...COLD AIR SURGING IN BEHIND THE LOW
(FALLING FROM RAP ANALYZED VALUES OF 0C FROM WEST-EAST OVER THE
CENTRAL U.P. AT 20Z TO -10 TO -16C AT 12Z SUNDAY AND -23C BY 00Z
MONDAY) WILL LEAD TO LAKE ENHANCEMENT FOR AREAS NEAR LAKE SUPERIOR
AS THE WIND DIRECTIONS BECOME FAVORABLE. THE WINDS WILL BE OUT OF
THE NORTHEAST INITIALLY THIS EVENING OVER WESTERN LAKE
SUPERIOR...BUT AS THE SURFACE/925MB LOW MOVES EAST-NORTHEAST THROUGH
NORTHEAST WISCONSIN AND SOUTH CENTRAL UPPER MICHIGAN TONIGHT...THE
WINDS WILL TRANSITION TO THE NORTH OVERNIGHT...NNW SUNDAY
MORNING...AND THEN NW SUNDAY AFTERNOON. THUS...EXPECT THE INITIAL
ENHANCEMENT TO OCCUR LATE IN THE EVENING OVER THE NE FAVORED
LOCATIONS AND THEN TRANSITION WITH THE WINDS INTO SUNDAY MORNING.
THESE STEADY BACKING WINDS WILL LIKELY BE ONE OF THE LIMITING
FACTORS TO HEAVIER SNOWFALL AMOUNTS. THE SECOND ITEM THAT SHOULD
KEEP SNOWFALL AMOUNTS IN THE LES ADVISORY CATEGORY WILL BE THE SHORT
PERIOD WHEN THE LAKE ENHANCEMENT AND LOW LEVEL TEMPERATURE PROFILE
FALL WITHIN THE DGZ. AT MOST LOCATIONS...IT APPEARS LIKE IT WILL
ONLY OCCUR FOR A 3 TO MAYBE 6HOUR PERIOD. THUS...EVEN THOUGH SNOW
RATIOS WILL QUICKLY RISE TO THE LOWER 20S...THEY WILL QUICKLY FALL
ONCE THE DEEPER MOISTURE DEPARTS AND THE INCREASING COLD AIR MOVES
THE CLOUD OUT OF THE DGZ. FINALLY...GUSTY WINDS MAY LIMIT SNOW
RATIOS FROM GROWING MUCH ABOVE 22/23-1 DURING THE FAVORED
PERIOD...EVEN THOUGH ALL OF THE CLOUD IS WITHIN THE DGZ.
OVERALL...ONLY MADE MINOR TWEAKS TO MUCH OF THE SNOWFALL FORECAST
FOR TONIGHT INTO SUNDAY MORNING...LARGELY WITH HANDLING THE TIMING
OF THE CHANGE OVER TO SNOW FROM NORTHWEST TO SOUTHEAST. THE FAVORED
HIGHER TERRAIN LOCATIONS WILL LIKELY SEE AMOUNTS THROUGH SUNDAY
MORNING IN THE 3-8INCH RANGE...WITH THE GREATEST AMOUNTS OVER THE
HURON MOUNTAINS WITH THE LONGER PERIOD OF FAVORABLE WIND
DIRECTIONS. THAT WOULD BE THE ONLY LOCATIONS WHERE SOME CONCERN OF
NEAR WARNING AMOUNT SNOW WOULD OCCUR...BUT THE SOCIETAL IMPACT WILL
BE LIMITED.
DEEPER MOISTURE FROM THE LOW PULLS OUT QUICKLY FROM WEST TO EAST ON
SUNDAY MORNING AND LEADS TO A TRANSITION TO PURE LAKE EFFECT. WITH
THAT DEEPER MOISTURE DEPARTING...MODELS ARE ONLY SHOWING MOISTURE
AND INVERSION HEIGHTS AROUND 4KFT...BUT WITH LAKE INDUCED
EQUILIBRIUM LEVELS AROUND 5-6KFT...COULD STILL BE SOME STRONGER SNOW
SHOWERS. BUT WITH COLDER AIR CONTINUING TO SURGE IN...MUCH OF THE
CLOUD LAYER WILL MOVE TO THE TOP OF OR ABOVE THE DGZ...WHICH SHOULD
LEAD TO A TRANSITION TO MORE OF COLUMN/PLATES. THEREFORE...WILL
CONTINUE THE IDEA OF LOWERING SNOW RATIOS TO THE HIGH TEENS OR
AROUND 20-1 FROM WEST TO EAST THROUGH THE DAY SUNDAY. THIS SHOULD
LEAD TO LESSER SNOWFALL AMOUNTS IN THE AFTERNOON...WHICH WILL STILL
BE AIDED BY SLOWLY BACKING WINDS TO THE NORTHWEST. OVERALL...HAVE
AFTERNOON AMOUNTS OF 1-2 INCHES IN MOST LOCATIONS...WITH SLIGHTLY
HIGHER VALUES OVER WESTERN ALGER COUNTY. THEREFORE...WILL KEEP LES
ADVISORIES AS IS...ALTHOUGH THE LONG TERM DID MAKE SOME ADJUSTMENTS
TO ALGER TO EXTEND INTO MONDAY. THINK THAT COVERS THE OVERALL IDEA
VERY WELL...SINCE THE NEGATIVES WITH SNOW RATIOS AND BACKING WINDS
SHOULD LIMIT THE POTENTIAL FOR 12HR SNOW AMOUNTS REACHING WARNING
VALUES.
THE COLD AIR SURGING IN WILL LEAD TO FALLING TEMPERATURES STARTING
LATE THIS EVENING OVER THE WEST AND PUSHING ACROSS THE REST OF THE
AREA THROUGH THE NIGHT. OVERNIGHT LOWS FOR TONIGHT AND HIGHS FOR
TOMORROW ARE FAIRLY TRICKY...AS THEY BOTH WILL LIKELY OCCUR DURING
THE TWO HOUR OVERLAP BETWEEN 12-14Z. THUS...TRIED TO FOCUS ON TEMPS
DURING THAT PERIOD TO USE FOR SIMILAR VALUES. WITH THE COLD AIR
CONTINUING TO SURGE IN THROUGH THE DAY ON SUNDAY...EXPECT STEADY OR
SLOWLY FALLING TEMPERATURES THROUGH THE REST OF THE DAY ON
SUNDAY. AFTERNOON VALUES OVER THE WEST WILL BE IN THE LOWER SINGLE
DIGITS ABOVE ZERO AND AROUND 10 DEGREES OVER THE EAST HALF.
FACTORING IN WIND CHILLS...TOMORROW AFTERNOON WILL FEEL ABOUT 50
DEGREES COLDER THAN THIS PAST AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 445 PM EST SAT DEC 28 2013
SUN NIGHT INTO MONDAY...ENHANCED LOW-LEVEL CONVERGENCE FROM
DEVELOPING LAND BREEZES AND LAKE-INDUCED TROUGHING WILL FAVOR
ALGER...NRN SCHOOLCRAFT AND LUCE COUNTIES FOR POTENTIAL ADVISORY
CRITERIA SNOWFALL. LES ADVISORIES WILL THEN LIKELY BE NEEDED FOR
THAT PORTION OF THE NE CWA WITH ADDITIONAL ACCUMULATIONS IN THE 3 TO
8 INCH RANGE FROM SUN NIGHT INTO MON MORNING.
WINDS ARE EXPECTED TO STEADILY BACK FROM NNW SUN EVENING TO WRLY BY
EARLY MON AFTERNOON AS SFC HIGH PRESSURE SLIDES FROM THE NRN PLAINS
INTO THE MID MISSISSIPPI VALLEY. THE STEADILY BACKING WINDS WILL
TEND TO SPREAD LES ACCUMULATION AROUND KEEPING MOST AREAS ON THE
LOWER END OF ADVISORY CRITERIA. FAR ERN ALGER AND NRN LUCE WILL BE
THE EXCEPTION WHERE MODELS INDICATE A LONGER PERIOD OF ENHANCED
LOW-LVL CONVERGENCE PARTICULARLY LATE SUN NIGHT INTO MONDAY
WHICH WILL LIKELY PUSH SNOWFALL AMOUNTS ON THE HIGHER END OF
ADVISORY CRITERIA (NEAR 8"). THE VERY DRY COLD ARCTIC AIRMASS ALONG
WITH THE SHORTER FETCH INTO NW UPPER MI WILL MAKE IT LESS FAVORABLE
FOR SIGNIFICANT LES THERE. ADDITIONAL LES WILL BE MORE ON THE ORDER
OF 2 TO LOCALLY 5 INCHES FOR SUN NIGHT INTO MON MORNING SO DO NOT
ANTICIPATE A NEED TO EXTEND LES ADVISORY THERE BEYOND SUNDAY.
HOWEVER...SOME OF THE MESOSCALE MODELS INDICATE THAT LOW-LVL
CONVERGENCE COULD INCREASE AND SOME ENHANCEMENT IS POSSIBLE WITH THE
APPROACH OF THE NEXT CLIPPER SHORTWAVE WHICH SHOULD FOCUS SOME
LOCALLY HEAVIER LES BANDS AND HIGHER ACCUMS BACK OVER THE KEWEENAW
MON AFTERNOON INTO MON EVENING...BUT FOR NOW THIS IS JUST REFLECTED
IN THE FCST GRIDS AND NO HEADLINE IS NEEDED YET.
THE OTHER ISSUE FOR SUNDAY NIGHT INTO MONDAY MORNING WILL BE THE
BITTER COLD ARCTIC AIRMASS SPREADING OVER THE REGION. WITH 8H TEMPS
FROM -22C TO -24C AND WINDS BACKING OFFSHORE TO A MORE WRLY
DIRECTION...THE WESTERN INTERIOR OF THE FCST AREA PARTICULARLY ALONG
THE WI BDR WILL BE UNDER THE GUN FOR ADVISORY CRITERIA WIND CHILLS
OF 25 TO 35 BELOW SUNDAY NIGHT INTO MON MORNING. GIVEN THE FOCUS ON
THE PRESENT LES HEADLINES ELECTED TO HOLD OFF ON WIND CHILL
ADVISORIES FOR NOW...BUT NO DOUBT ONE WILL BE NEEDED FOR A GOOD
PORTION OF THE WESTERN INTERIOR SUN NIGHT INTO MON MORNING.
MON NIGHT-THU...AS MODELS SHOW THE POLAR VORTEX GRADUALLY SHIFTING
FROM HUDSON BAY TO NRN QUEBEC BY TUE EVENING...VERY COLD ARCTIC AIR
WILL DOMINATE THE UPPER GREAT LAKES THROUGH MIDWEEK. WITH 850 MB
TEMPS DROPPING INTO THE -24C TO -29C RANGE...LES WILL PERSIST FOR
LOCATIONS FAVORED BY NW TO WNW FLOW. MODELS IN GOOD AGREEMENT WITH
TIMING OF NEXT CLIPPER SHORTWAVE ACROSS THE AREA MON NIGHT INTO TUE
MORNING. THIS SHORTWAVE WILL REINFORCE ARCTIC AIR WHILE ALSO
SPREADING MID Q-VECT CONV AND DEEPER MOISTURE ACROSS THE REGION.
MODELS INDICATE THIS SHORTWAVE COULD PROVIDE ENHANCEMENT TO LES
WHILE ALSO SHARPENING LAKE-INDUCED TROFFING AND LOW-LVL CONVERGENCE
OVER ERN LAKE SUPERIOR. WHILE THE INFLUX OF COLDER -24 TO -27C 8H
TEMPS BY TUESDAY WILL EVENTUALLY LEAD TO POOR SNOW GROWTH AND
SMALLER SNOWFLAKES...THE WRF-ARW BUFR SNDG FOR GRAND MARAIS MON
NIGHT INTO EARLY TUE SHOWS A SOMEWHAT FAVORABLE SNOW GROWTH PROFILE
WITH THE DGZ INITIALLY INTERSECTING THE BETTER MODEL OMEGA FOCUSED
WITHIN THE CONVECTIVE BOUNDARY LAYER. THIS COULD INITIALLY LEAD TO
HIGHER SLR/S...FLUFFIER SNOW AND GREATER ACCUMULATIONS ESPECIALLY
FOR ERN ALGER AND LUCE COUNTIES. GIVEN THE ABOVE FAVORABLE FACTORS
AND POTENTIAL FOR ENHANCEMENT THERE IS A POTENTIAL FOR HIGH END
ADVISORY LES ACCUMS POSSIBLY PUSHING LES WARNING AMTS MON NIGHT INTO
TUE MORNING FOR ERN ALGER AND LUCE COUNTIES. AFTER TUESDAY...MODELS NOT
INDICATING ANY DISCERNIBLE CLIPPER SHORTWAVES FOR MIDWEEK AS 850 MB
TEMPS GENERALLY REMAIN IN THE -22 TO -26C RANGE. THE COLDER AIRMASS
WILL GENERALLY FAVOR SMALL SNOWFLAKES WITH THE ABSENCE OF
ENHANCEMENT/DEEPER MOISTURE WHICH WILL LIMIT OVERALL ACCUMULATIONS
BUT STILL LEAD TO LOW VISIBILITIES. OUTSIDE OF THE LES...SEVERE WIND
CHILLS CAN BE EXPECTED AT TIMES AS VALUES DROP INTO THE -20 TO -35
RANGE...MAINLY IN THE NIGHTTIME AND MORNING HRS.
MODELS SHOW SIGNS OF TRENDING TOWARD LESS AMPLIFIED PATTERN BY THE
END OF THE WEEK WITH WAA DEVELOPING BY FRI. AS SFC HIGH PRESSURE
SLIDES EAST LATE IN THE WEEK...BOTH THE ECMWF AND GFS DEVELOP AREA
OF LIGHT SNOW IN REGION OF WAA/ISENTROPIC ASCENT AHEAD OF A SHRTWV
MOVING DOWN FM NW ONTARIO. THIS SNOW LOOKS TO SPREAD INTO UPPER MI
LATE FRI OR FRI NIGHT. AS SYSTEM SNOW TAPERS OFF EARLY SAT...LIGHT
LES COULD DEVELOP LATE IN THE DAY AS WINDS SHIFT NORTHERLY BEHIND
FRONTAL PASSAGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1254 PM EST SAT DEC 28 2013
A COLD FRONT THAT HAS STALLED OVER SOUTHERN LAKE SUPERIOR HAS
ALLOWED WARM MOIST AIR TO SURGE NORTHEAST AND LEAD TO LOW END MVFR
AND HIGH END IFR CONDITIONS AT ALL THREE TAF SITES THIS AFTERNOON.
EXPECT THIS TO CONTINUE THROUGH MUCH OF THE AFTERNOON...BUT THERE
ARE A COUPLE CONCERNS. FIRST...BELIEVE THERE IS SOME -DZ/FZDZ IN
THE KEWEENAW SO HAVE CONTINUED SLIGHTLY LOWER VISIBILITIES AND
-FZDZ IN THE TAF. WILL NEED TO MONITOR LOWER CEILINGS WITH THE
EASTERLY FLOW DEVELOPING OFF LAKE SUPERIOR. AT KSAW...A POCKET OF
DRIER AIR DEVELOPED NEAR LAKE MICHIGAN AND SURGED NORTH.
UNFORTUNATELY...WITH HIGH CLOUDS STREAMING IN AHEAD OF THE NEXT
DISTURBANCE...CAN/T GET A GOOD HANDLE ON THE WESTWARD EXTENT OF
THOSE BREAKS. LOW LEVEL SOUTHWESTERLY WINDS AND LOW CLOUDS AT KIMT
WOULD LEAD TO BELIEVE THE LOW CLOUDS WILL HOLD FOR MUCH OF THE
AFTERNOON.
HEADING INTO THIS EVENING...A LOW IN CENTRAL MINNESOTA WILL SHIFT
EAST ACROSS WISCONSIN TONIGHT AND DRAG AN AREA OF SNOW SOUTHEAST
FROM SOUTHERN MANITOBA AND ACROSS THE AREA. THIS SNOW...COMBINED
WITH LAKE ENHANCEMENT AND GUSTY NORTHEST TO NORTHERLY WINDS WILL
LEAD TO VISIBILITIES FALLING BELOW ALTERNATE LANDING MINS. WOULDN/T
BE SURPRISED IF THERE WERE A FEW PERIODS OF AIRFIELD LANDING MINS
AT KCMX WITH THE STRONGER WINDS AND BETTER SYNOPTIC SNOW. THIS SNOW
WILL TRANSITION TO LAKE EFFECT ON SUNDAY MORNING AS THE LOW
DEPARTS. WOULD EXPECT VISIBILITIES TO COME UP SOME...BUT WITH FINER
FLAKES EXPECTED...HAVE LEFT AT LOW END MVFR OR IFR VALUES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EST SAT DEC 28 2013
WINDS TO STAY LIGHT UNTIL SFC LOW BRINGS TIGHTENING PRESSURE
GRADIENT TO WESTERN LAKE SUPERIOR THIS AFTERNOON. BY LATE
AFTERNOON...WILL SEE FREQUENT GALE FORCE GUSTS OVER WESTERN LAKE
SUPERIOR WITH NE GALES EXPECTED BY THE EVENING. AS THE SFC LOW
PASSES TO THE SE OF THE AREA OVERNIGHT...NORTH WINDS TO GRADUALLY
RELAX. MUCH COLDER AIR ARRIVING TONIGHT WILL PRODUCE HEAVY FREEZING
SPRAY AS WELL. WINDS GO BELOW 25 KNOTS SUNDAY AFTERNOON AND BELOW 20
KNOTS BY MONDAY AFTERNOON. WINDS REMAIN BELOW 20 KNOTS THROUGH THE
REMAINDER OF THE FORECAST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 7 PM EST
SUNDAY FOR MIZ004-005-084.
LAKE EFFECT SNOW ADVISORY FROM 1 PM SUNDAY TO 7 AM EST MONDAY
FOR MIZ085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST /6 PM CST/ SUNDAY FOR
MIZ001>003-009.
LAKE EFFECT SNOW ADVISORY FROM 1 AM SUNDAY TO 1 PM EST MONDAY
FOR MIZ006.
LAKE EFFECT SNOW ADVISORY FROM 7 PM SUNDAY TO 1 PM EST MONDAY
FOR MIZ007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 1 AM SUNDAY TO 1 AM EST
WEDNESDAY FOR LSZ265>267.
GALE WARNING UNTIL 7 AM EST /6 AM CST/ SUNDAY FOR LSZ162-263>266.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST /MIDNIGHT CST/
MONDAY FOR LSZ162-263-264.
HEAVY FREEZING SPRAY WARNING FROM 1 AM SUNDAY TO 6 PM EST MONDAY
FOR LSZ248>251.
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST /6 PM CST/ SUNDAY
FOR LSZ240>247.
GALE WARNING UNTIL 5 AM EST /4 AM CST/ SUNDAY FOR LSZ241.
GALE WARNING UNTIL 5 AM EST /4 AM CST/ SUNDAY FOR LSZ240.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...VOSS
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
422 PM EST SAT DEC 28 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 419 PM EST SAT DEC 28 2013
A STALLED FRONTAL BOUNDARY OVER SOUTHERN LAKE SUPERIOR AND NORTHERN
UPPER MICHIGAN HAS LED TO DREARY CONDITIONS FOR MUCH OF UPPER
MICHIGAN TODAY. ON THE PLUS SIDE...TEMPERATURES HAVE BEEN IN THE
LOW TO MID 30S ALONG AND SOUTH OF THE BOUNDARY WHERE THERE HAVE
EVEN BEEN A FEW PEAKS OF SUNSHINE. JUST TO THE NORTH OF THE
BOUNDARY...FAVORABLE EASTERLY FLOW OFF LAKE SUPERIOR HAS LED TO
SOME FZDZ...FOG...AND -SHSN OVER THE KEWEENAW PENINSULA. A SPOTTER
REPORT AROUND 3PM INDICATED A SLIGHT GLAZE IN MOHAWK SHORTLY
AFTER THE VISIBILITY REALLY DROPPED AT KCMX. THINK THAT
FREEZING DRIZZLE WILL REMAIN A THREAT OVER THE NEXT COUPLE OF HOURS
AND EVEN DRIFT SOUTHEAST THROUGH THE EVENING...AS MODELS SHOW A
LACK OF ICE CRYSTALS IN THE CLOUDS BEFORE THE MAIN PRECIPITATION
ARRIVES FROM SOUTHERN CANADA LATE THIS EVENING. ALSO FOR THIS
EVENING...DID ADD SOME PATCHY FOG OVER THE SOUTHEAST PART OF THE
CWA WHERE WINDS WILL BE LIGHT AND THERE HAVE BEEN SOME BREAKS IN
THE CLOUDS.
THE LOW THAT IS CURRENTLY CENTERED IN SOUTH CENTRAL MINNESOTA WILL
CONTINUE EAST TONIGHT AND SUNDAY...BEING CENTERED JUST NORTH OF LAKE
ONTARIO BY 00Z MONDAY. AS THIS LOW SWEEPS EAST...AN AREA OF SNOW
(CURRENTLY IN SOUTHWEST ONTARIO AND ALSO ENTERING NORTHWEST
MINNESOTA) WILL SWEEP ACROSS THE UPPER GREAT LAKES LATE THIS
EVENING THROUGH EARLY SUNDAY MORNING. THE SYNOPTIC SNOW WILL BE
AIDED BY THE RIGHT REAR OF THE 110KT UPPER JET THAT SWEEPS ACROSS
TONIGHT. IN ADDITION...POCKET OF 800-600MB FGEN WILL SLIDE THROUGH
WITH THE 850/700MB TROUGH. THUS...EXPECT A PERIOD OF LIGHT SNOW TO
MOVE ACROSS MUCH OF UPPER MICHIGAN FROM WEST TO EAST. WITH THE BEST
FORCING OVER THE NORTHERN HALF OF THE CWA...EXPECT THE BEST SYNOPTIC
SNOWFALL THERE...WHICH WILL BE AIDED BY LAKE ENHANCEMENT. OVER THE
SOUTHERN HALF...ONLY EXPECT A LIGHT DUSTING TO AN INCH AWAY FROM THE
LAKE SUPERIOR INFLUENCES WITH SNOW RATIOS AROUND NORMAL VALUES OF
13-1.
AS FOR THE LAKE ENHANCEMENT...COLD AIR SURGING IN BEHIND THE LOW
(FALLING FROM RAP ANALYZED VALUES OF 0C FROM WEST-EAST OVER THE
CENTRAL U.P. AT 20Z TO -10 TO -16C AT 12Z SUNDAY AND -23C BY 00Z
MONDAY) WILL LEAD TO LAKE ENHANCEMENT FOR AREAS NEAR LAKE SUPERIOR
AS THE WIND DIRECTIONS BECOME FAVORABLE. THE WINDS WILL BE OUT OF
THE NORTHEAST INITIALLY THIS EVENING OVER WESTERN LAKE
SUPERIOR...BUT AS THE SURFACE/925MB LOW MOVES EAST-NORTHEAST THROUGH
NORTHEAST WISCONSIN AND SOUTH CENTRAL UPPER MICHIGAN TONIGHT...THE
WINDS WILL TRANSITION TO THE NORTH OVERNIGHT...NNW SUNDAY
MORNING...AND THEN NW SUNDAY AFTERNOON. THUS...EXPECT THE INITIAL
ENHANCEMENT TO OCCUR LATE IN THE EVENING OVER THE NE FAVORED
LOCATIONS AND THEN TRANSITION WITH THE WINDS INTO SUNDAY MORNING.
THESE STEADY BACKING WINDS WILL LIKELY BE ONE OF THE LIMITING
FACTORS TO HEAVIER SNOWFALL AMOUNTS. THE SECOND ITEM THAT SHOULD
KEEP SNOWFALL AMOUNTS IN THE LES ADVISORY CATEGORY WILL BE THE SHORT
PERIOD WHEN THE LAKE ENHANCEMENT AND LOW LEVEL TEMPERATURE PROFILE
FALL WITHIN THE DGZ. AT MOST LOCATIONS...IT APPEARS LIKE IT WILL
ONLY OCCUR FOR A 3 TO MAYBE 6HOUR PERIOD. THUS...EVEN THOUGH SNOW
RATIOS WILL QUICKLY RISE TO THE LOWER 20S...THEY WILL QUICKLY FALL
ONCE THE DEEPER MOISTURE DEPARTS AND THE INCREASING COLD AIR MOVES
THE CLOUD OUT OF THE DGZ. FINALLY...GUSTY WINDS MAY LIMIT SNOW
RATIOS FROM GROWING MUCH ABOVE 22/23-1 DURING THE FAVORED
PERIOD...EVEN THOUGH ALL OF THE CLOUD IS WITHIN THE DGZ.
OVERALL...ONLY MADE MINOR TWEAKS TO MUCH OF THE SNOWFALL FORECAST
FOR TONIGHT INTO SUNDAY MORNING...LARGELY WITH HANDLING THE TIMING
OF THE CHANGE OVER TO SNOW FROM NORTHWEST TO SOUTHEAST. THE FAVORED
HIGHER TERRAIN LOCATIONS WILL LIKELY SEE AMOUNTS THROUGH SUNDAY
MORNING IN THE 3-8INCH RANGE...WITH THE GREATEST AMOUNTS OVER THE
HURON MOUNTAINS WITH THE LONGER PERIOD OF FAVORABLE WIND
DIRECTIONS. THAT WOULD BE THE ONLY LOCATIONS WHERE SOME CONCERN OF
NEAR WARNING AMOUNT SNOW WOULD OCCUR...BUT THE SOCIETAL IMPACT WILL
BE LIMITED.
DEEPER MOISTURE FROM THE LOW PULLS OUT QUICKLY FROM WEST TO EAST ON
SUNDAY MORNING AND LEADS TO A TRANSITION TO PURE LAKE EFFECT. WITH
THAT DEEPER MOISTURE DEPARTING...MODELS ARE ONLY SHOWING MOISTURE
AND INVERSION HEIGHTS AROUND 4KFT...BUT WITH LAKE INDUCED
EQUILIBRIUM LEVELS AROUND 5-6KFT...COULD STILL BE SOME STRONGER SNOW
SHOWERS. BUT WITH COLDER AIR CONTINUING TO SURGE IN...MUCH OF THE
CLOUD LAYER WILL MOVE TO THE TOP OF OR ABOVE THE DGZ...WHICH SHOULD
LEAD TO A TRANSITION TO MORE OF COLUMN/PLATES. THEREFORE...WILL
CONTINUE THE IDEA OF LOWERING SNOW RATIOS TO THE HIGH TEENS OR
AROUND 20-1 FROM WEST TO EAST THROUGH THE DAY SUNDAY. THIS SHOULD
LEAD TO LESSER SNOWFALL AMOUNTS IN THE AFTERNOON...WHICH WILL STILL
BE AIDED BY SLOWLY BACKING WINDS TO THE NORTHWEST. OVERALL...HAVE
AFTERNOON AMOUNTS OF 1-2 INCHES IN MOST LOCATIONS...WITH SLIGHTLY
HIGHER VALUES OVER WESTERN ALGER COUNTY. THEREFORE...WILL KEEP LES
ADVISORIES AS IS...ALTHOUGH THE LONG TERM DID MAKE SOME ADJUSTMENTS
TO ALGER TO EXTEND INTO MONDAY. THINK THAT COVERS THE OVERALL IDEA
VERY WELL...SINCE THE NEGATIVES WITH SNOW RATIOS AND BACKING WINDS
SHOULD LIMIT THE POTENTIAL FOR 12HR SNOW AMOUNTS REACHING WARNING
VALUES.
THE COLD AIR SURGING IN WILL LEAD TO FALLING TEMPERATURES STARTING
LATE THIS EVENING OVER THE WEST AND PUSHING ACROSS THE REST OF THE
AREA THROUGH THE NIGHT. OVERNIGHT LOWS FOR TONIGHT AND HIGHS FOR
TOMORROW ARE FAIRLY TRICKY...AS THEY BOTH WILL LIKELY OCCUR DURING
THE TWO HOUR OVERLAP BETWEEN 12-14Z. THUS...TRIED TO FOCUS ON TEMPS
DURING THAT PERIOD TO USE FOR SIMILAR VALUES. WITH THE COLD AIR
CONTINUING TO SURGE IN THROUGH THE DAY ON SUNDAY...EXPECT STEADY OR
SLOWLY FALLING TEMPERATURES THROUGH THE REST OF THE DAY ON
SUNDAY. AFTERNOON VALUES OVER THE WEST WILL BE IN THE LOWER SINGLE
DIGITS ABOVE ZERO AND AROUND 10 DEGREES OVER THE EAST HALF.
FACTORING IN WIND CHILLS...TOMORROW AFTERNOON WILL FEEL ABOUT 50
DEGREES COLDER THAN THIS PAST AFTERNOON.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 509 AM EST SAT DEC 28 2013
SAT NIGHT...UPPER LEVEL DIV WITH THE RIGHT ENTRANCE OF THE 130KT
250-300 MB JET THROUGH NRN ONTARIO/WRN QUEBEC AND ASSOCIATED
800-600 MB FGEN WILL RESULT IN STRONG ENOUGH UPWARD MOTION TO
SUPPORT A BAND OF SNOW FROM NRN MN THROUGH NRN UPPER MI.
HOWEVER...PRIOR TO THE ARRIVAL OF THE DEEPER MOISTURE AND COLD AIR
FROM THE NORTH...00Z/06Z NAM FCST SOUNDINGS SUGGEST WITH ONLY
SHALLOW MOISTURE LACKING ICE NUCLEI PRESENT...SOME PATCHY FREEZING
DRIZZLE MAY PERSIST THROUGH AT LEAST 03Z. CONSENSUS QPF AMOUNTS OF
0.10-0.15 WITH SLR VALUES IN THE 10/1 TO 15/1 RANGE WOULD GIVE
SYNOPTIC SNOW AMOUNTS OF 1 TO 2 INCHES...GREATEST NORTH. IN
ADDITION...CYCLONIC NE TO NNE FLOW INTO NRN UPPER MI WILL ALSO BRING
ADDITIONAL LAKE ENHANCED SNOW AMOUNTS. SINCE SLR VALUES ONLY CLIMB
NEAR 20/1 LATE SAT NIGHT WITH THE ARRIVAL OF THE COLDER
AIR...ADDITIONAL ENHANCEMENT AMOUNTS IN THE 1 TO 4 INCH RANGE WOULD
KEEP OVERALL TOTAL GENERALLY IN THE ADVISORY RANGE OF 3 TO 6 INCHES.
IN ADDITION...NRLY WINDS GUSTING TO 25 TO 35 MPH IN OPEN AREAS NEAR
THE LAKE SHORES WILL PRODUCE BLOWING AND DRIFTING SNOW.
SUN...LAKE ENHANCED SNOW WILL TRANSITION TO PURE LES SUN MORNING
AS THE DEEPER MOISTURE AND MID LVL QVECT CONV DEPARTS TO THE EAST.
850 MB TEMPS DROPPING INTO THE -19C TO -22C RANGE BY 18Z AS 850-700
MB MOISTURE STILL LINGERS OVER AREA WILL FAVOR CONTINUED MODERATE TO
HEAVY LES...ESPECIALLY FOR LOCATIONS FAVORED BY NRLY UPSLOPE FLOW.
EXPECT LES RATES TO GRADUALLY DIMINISH IN THE AFTERNOON AS WINDS
BACK AND INVERSION HEIGHTS DROP TO AROUND 5K FT. EXPECT THE GREATEST
TOTAL ACCUMULATIONS FROM IRONWOOD THROUGH THE PORCUPINE MOUNTAINS TO
ROCKLAND IN THE WEST AND FROM HERMAN THROUGH THE HURON MOUNTAINS TO
NEGAUNEE OVER THE NORTH CENTRAL. AS THE WINDS BACK TO THE NNW THE
STRONGER LOW LEVEL CONV AND HEAVIER LES WILL SHIFT TOWARD WRN ALGER
COUNTY IN THE AFTERNOON.
SUN NIGHT...ENHANCED LOW-LEVEL CONVERGENCE FROM DEVELOPING LAND
BREEZES WILL FAVOR ALGER COUNTY INTO NRN SHCOOLCRAFT AND LUCE COUNTIES.
LES ADVISORIES WILL THEN LIKELY BE NEEDED FOR THAT PORTION OF THE NE
CWA WITH ADDITIONAL ACCUMULATIONS IN THE 2 TO 6 INCH RANGE.
OTHERWISE...THE VERY DRY COLD ARCTIC AIRMASS WITH THE SHORTER FETCH
INTO NW UPPER MI WILL BE LESS FAVORABLE FOR SIGNFICANT LES. SINCE
ONLY 1 TO 3 INCHES OF ADDITIONAL SNOWFALL IS EXPECTED...THE LES ADVY
WAS NOT EXTENDED THROUGH THIS PERIOD.
MON-WED...AS THE POLAR VORTEX GRADUALLY SHIFTS FROM HUDSON BAY TO
NRN QUEBEC...VERY COLD ARCTIC AIR WILL DOMINATE THE WRN GREAT LAKES.
WITH 850 MB TEMPS DROPPING INTO THE -23C TO -28C RANGE...LES WILL
PERSIST FOR LOCATIONS FAVORED BY NW TO W FLOW. AS TO BE EXPECTED
MODELS STILL SHOWING DIFFERENCES WITH TIMING OF SHORTWAVES MOVING
THROUGH THE REGION WITH THE ASSOCIATED WIND SHIFTS. THERE MAY BE
PERIODS WHERE THE WINDS ARE LIGHT ENOUGH FOR LAKE INDUCED TROUGHING
TO DOMINATE THE LOW LEVEL FLOW. THERE MAY ALSO BE PERIOD WHEN
CONVERGENT WRLY FLOW DEVELOPS OVER THE WEST WHICH MAY BRING A PERIOD
OF HEAVIER LES INTO THE KEWEENAW. THE COLD AIRMASS WILL ALSO FAVOR
SMALL SNOWFLAKES THAT WILL LIMIT OVERALL ACCUMULATIONS BUT STILL
LEAD TO LOW VISIBILITIES. OUTSIDE OF THE LES...SEVERE WIND CHILLS AT
TIMES ASE VALUES DROP INTO THE -20 TO -35 RANGE.
MODELS SHOW SIGNS OF TRENDING TOWARD LESS AMPLIFIED PATTERN BY THE
END OF THE WEEK WITH WAA DEVELOPING. SFC HIGH PRESSURE OVER THE
REGION SHOULD ENSURE MOSTLY DRY CONDITIONS ON THURSDAY...EXCEPT FOR
SOME LINGERING LES CLOSE TO LAKE SUPERIOR AS WINDS BECOME LIGHT WITH
THE ARCTIC HIGH OVER THE REGION. BOTH THE ECMWF AND GFS DEVELOP AREA
OF LIGHT SNOW IN AREA OF WAA/ISENTROPIC ASCENT AHEAD OF A SHRTWV MOVING
TOWARD NW ONTARIO THAT MAY SPREAD INTO UPPPER MI FRI OR FRI NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1254 PM EST SAT DEC 28 2013
A COLD FRONT THAT HAS STALLED OVER SOUTHERN LAKE SUPERIOR HAS
ALLOWED WARM MOIST AIR TO SURGE NORTHEAST AND LEAD TO LOW END MVFR
AND HIGH END IFR CONDITIONS AT ALL THREE TAF SITES THIS AFTERNOON.
EXPECT THIS TO CONTINUE THROUGH MUCH OF THE AFTERNOON...BUT THERE
ARE A COUPLE CONCERNS. FIRST...BELIEVE THERE IS SOME -DZ/FZDZ IN
THE KEWEENAW SO HAVE CONTINUED SLIGHTLY LOWER VISIBILITIES AND
-FZDZ IN THE TAF. WILL NEED TO MONITOR LOWER CEILINGS WITH THE
EASTERLY FLOW DEVELOPING OFF LAKE SUPERIOR. AT KSAW...A POCKET OF
DRIER AIR DEVELOPED NEAR LAKE MICHIGAN AND SURGED NORTH.
UNFORTUNATELY...WITH HIGH CLOUDS STREAMING IN AHEAD OF THE NEXT
DISTURBANCE...CAN/T GET A GOOD HANDLE ON THE WESTWARD EXTENT OF
THOSE BREAKS. LOW LEVEL SOUTHWESTERLY WINDS AND LOW CLOUDS AT KIMT
WOULD LEAD TO BELIEVE THE LOW CLOUDS WILL HOLD FOR MUCH OF THE
AFTERNOON.
HEADING INTO THIS EVENING...A LOW IN CENTRAL MINNESOTA WILL SHIFT
EAST ACROSS WISCONSIN TONIGHT AND DRAG AN AREA OF SNOW SOUTHEAST
FROM SOUTHERN MANITOBA AND ACROSS THE AREA. THIS SNOW...COMBINED
WITH LAKE ENHANCEMENT AND GUSTY NORTHEST TO NORTHERLY WINDS WILL
LEAD TO VISIBILITIES FALLING BELOW ALTERNATE LANDING MINS. WOULDN/T
BE SURPRISED IF THERE WERE A FEW PERIODS OF AIRFIELD LANDING MINS
AT KCMX WITH THE STRONGER WINDS AND BETTER SYNOPTIC SNOW. THIS SNOW
WILL TRANSITION TO LAKE EFFECT ON SUNDAY MORNING AS THE LOW
DEPARTS. WOULD EXPECT VISIBILITIES TO COME UP SOME...BUT WITH FINER
FLAKES EXPECTED...HAVE LEFT AT LOW END MVFR OR IFR VALUES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EST SAT DEC 28 2013
WINDS TO STAY LIGHT UNTIL SFC LOW BRINGS TIGHTENING PRESSURE
GRADIENT TO WESTERN LAKE SUPERIOR THIS AFTERNOON. BY LATE
AFTERNOON...WILL SEE FREQUENT GALE FORCE GUSTS OVER WESTERN LAKE
SUPERIOR WITH NE GALES EXPECTED BY THE EVENING. AS THE SFC LOW
PASSES TO THE SE OF THE AREA OVERNIGHT...NORTH WINDS TO GRADUALLY
RELAX. MUCH COLDER AIR ARRIVING TONIGHT WILL PRODUCE HEAVY FREEZING
SPRAY AS WELL. WINDS GO BELOW 25 KNOTS SUNDAY AFTERNOON AND BELOW 20
KNOTS BY MONDAY AFTERNOON. WINDS REMAIN BELOW 20 KNOTS THROUGH THE
REMAINDER OF THE FORECAST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 7 PM EST
SUNDAY FOR MIZ004-005-084.
LAKE EFFECT SNOW ADVISORY FROM 1 PM SUNDAY TO 7 AM EST MONDAY
FOR MIZ085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST /6 PM CST/ SUNDAY FOR
MIZ001>003-009.
LAKE EFFECT SNOW ADVISORY FROM 1 AM SUNDAY TO 1 PM EST MONDAY
FOR MIZ006.
LAKE EFFECT SNOW ADVISORY FROM 7 PM SUNDAY TO 1 PM EST MONDAY
FOR MIZ007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 1 AM SUNDAY TO 1 AM EST
WEDNESDAY FOR LSZ265>267.
GALE WARNING UNTIL 7 AM EST /6 AM CST/ SUNDAY FOR LSZ162-263>266.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST /MIDNIGHT CST/
MONDAY FOR LSZ162-263-264.
HEAVY FREEZING SPRAY WARNING FROM 1 AM SUNDAY TO 6 PM EST MONDAY
FOR LSZ248>251.
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST /6 PM CST/ SUNDAY
FOR LSZ240>247.
GALE WARNING UNTIL 5 AM EST /4 AM CST/ SUNDAY FOR LSZ241.
GALE WARNING UNTIL 5 AM EST /4 AM CST/ SUNDAY FOR LSZ240.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...JLB
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1156 PM EST FRI DEC 27 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 507 PM EST FRI DEC 27 2013
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALF ACROSS
THE UPR GRT LKS BTWN TROFFING OVER ERN NAMERICA AND UPR RDG IN THE
ROCKIES. SW FLOW/ISENTROPIC ASCENT IN ADVANCE OF SHRTWV DIGGING SEWD
THRU ONTARIO HAS BROUGHT LOTS OF CLDS TO THE CWA. RADAR/SFC OBS
INDICATE SN IS FALLING OVER LK SUP CLOSER TO THE SHARPER ISENTROPIC
ASCENT/SHRTWV AND ACCOMPANYING SFC LO TRACK...BUT DRY WEDGE BTWN
H8-7 SHOWN ON THE 12Z INL RAOB HAS LIMITED THE COVERAGE OF THE SN
FARTHER SW OVER THE LAND CWA. OTRW...SSW LLVL FLOW HAS ADVECTED
WARMER AIR INTO UPR MI...WITH TEMPS THIS AFTN APRCHG ABV 32 AT IWD.
BUT TEMPS REMAIN WELL BLO FRZG OVER THE INTERIOR CENTRAL. THERE IS
SOME CLRG IN MN EXTENDING TOWARD WRN UPR MI WHERE THE LLVL WARMING
HAS BEEN MOST AGGRESSIVE ON THE SRN FLANK OF THE SFC LO SHIFTING
ESEWD NEAR THE MN/CNDN BORDER AND IN ADVANCE OF AN ATTENDANT LO PRES
TROF EXTENDING SWWD INTO THE ERN DAKOTAS. BUT MORE LO CLDS AND SOME
GUSTY NW WINDS FOLLOW THIS TROF FM NDAKOTA INTO MANITOBA/ADJOINING
ONTARIO. FARTHER TO THE W...A STRONG SHRTWV IS MOVING OVER THE WRN
UPR RDG INTO THE PAC NW/BRITISH COLUMBA.
MAIN FCST CONCERNS IN THE SHORT TERM ARE CLD TRENDS/POPS THIS AFTN
RELATED TO THE ONGOING WAD AHEAD OF THE APRCHG DISTURBANCE AND THEN
THE CHC FOR SOME -SN OR EVEN FREEZING DRIZZLE TNGT INTO SAT
FOLLOWING THE TROF PASSAGE.
LATE THIS AFTN/TNGT...BEST CHC FOR SOME WAD SN LATE THIS AFTN INTO
THE EVNG WL BE OVER THE ERN CWA WHERE GUIDANCE SHOWS DEEPER
SATURATION UNDER THE SHARPER ISENROPIC ASCENT DEEPER INTO THE
RETREATING COLD AIR. THE CHC POPS OVER THE ERN CWA WL SHIFT TO THE E
THIS EVNG FOLLOWING PASSAGE OF DISTURBANCE AND END OF WAD/ISENTROPIC
ASCENT. ALTHOUGH THERE WL BE SOME CLRG OVER THE W LATE THIS AFTN
INTO EARLY EVNG PER CURRENT OBS/STLT TRENDS...PASSAGE OF SFC LO PRES
TROF WL BRING A RETURN OF MORE LLVL MSTR/LO CLDS. SOME OF THE MODELS
ALSO GENERATE LGT PCPN OVER MAINLY THE W IN AREAS WHERE WNW FLOW WL
UPSLOPE DESPITE PRESENCE OF LARGER SCALE QVECTOR DVGC/DNVA/WEAK CAD
FOLLOWING THE SHRTWV. FCST SDNGS INDICATE THE MSTR WL BE CONFINED TO
THE LOWEST FEW THOUSAND FEET AND WELL BLO THE DGZ AS INCOMING
AIRMASS IS MARITIME POLAR IN ORIGIN. IN FACT...H85 TEMPS ARE FCST TO
FALL NO LOWER THAN -6C TO -8C EVEN OVER THE TIP OF THE KEWEENAW THRU
12Z SAT...TOO WARM FOR ANY LES. SO RETAINED MENTION OF SOME FREEZING
DRIZZLE AS WELL AS FINE SN/FLURRIES IN THESE UPSLOPE AREAS. AS THE
FLOW AND UPSLOPE WIND COMPONENT DIMINISHES LATE WITH ARRIVAL OF
WEAKER PRES GRADIENT...ANY -FZDZ MAY DIMINISH A BIT AS WELL. WEAKENS
DOWNSLOPE NATURE OF THE EXPECTED LLVL FLOW IN THE WAKE OF THE TROF
MAY RESULT IN SOME CLRG OVER THE SCENTRAL. OVERNGT TEMPS WL BE MUCH
WARMER THAN ON RECENT NGTS GIVEN EXPECTED CLD COVER/MODEST CHILL OF
AIRMASS. THE LOWEST MIN TEMPS ARE MOST LIKELY OVER THE SCENTRAL
WHERE MORE SUSTAINED CLRG SHUD ALLOW FOR A SHARPER TEMP DROP. SOME
FOG MAY DVLP IN THESE AREAS AS WELL WITH RELATIVELY HI SFC DEWPTS.
SAT...FOCUS SHIFTS TO TIMING/IMPACT OF SHRTWV NOW MOVING INTO THE
PAC NW AND ARPCH OF COLD FNT FM THE N. GUIDANCE SHOWS SFC COLD FNT
AND ACCOMPANYING BAND OF H85-7 FGEN SHIFTING SLOWLY S INTO THE NRN
CWA BY EARLY AFTN AS THE FLOW TURNS MORE TO THE NNE WELL TO THE S OF
COLD HI PRES BLDG THRU CENTRAL CANADA. SINCE THE MSTR IS FCST TO
STILL BE RELATIVELY SHALLOW...FREEZING DRIZZLE AS WELL AS SOME LGT
SN/FLURRIES MAY BE THE PTYPE...ESPECIALLY IN UPSLOPE AREAS NEAR LK
SUP. BUT AS THE SHRTWV TO THE W APRCHS LATER IN THE DAY...VIGOROUS
H85-5 QVECTOR CNVGC AND SOME UPR DVGC IN RRQ OF 140KT H3 JET MAX
STREAKING ACRS ONTARIO WL BRING A RETURN OF DEEPER MSTR/HIER POPS
OVER AT LEAST THE NRN TIER. EXPECT THE HIEST TEMPS AOA FRZG OVER THE
SCENTRAL...WHERE THE FNT WL NOT LIKELY PASS UNTIL AFTER 00Z SUN.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 507 PM EST FRI DEC 27 2013
SAT NIGHT...UPPER LEVEL DIV WITH THE RIGHT ENTRANCE OF THE 130KT
250-300 MB JET THROUGH NRN ONTARIO/WRN QUEBEC AND ASSOCIATED 700
MB FGEN WILL RESULT IN STRONG ENOUGH UPWARD MOTION TO SUPPORT A BAND
OF SNOW FROM NRN MN THROUGH THE NRN LAKES. THE 12Z MODELS ARE IN
GENERAL AGREEMENT WITH POSITION OF HEAVIER PCPN BAND THROUGH NRN
UPPER MI. CONSENSUS QPF AMOUNTS OF 0.15-0.30 WITH SLR VALUES IN THE
15/1 RANGE WOULD GIVE SYNOPTIC SNOW AMOUNTS OF 1 TO LOCALLY 4 INCHES
...GREATEST NORTH. IN ADDITION...CYCLONIC NE TO NNE FLOW INTO NRN
UPPER MI WILL ALSO BRING ADDITIONAL LAKE ENHANCED SNOW AMOUNTS.
SINCE SLR VALUES ONLY CLIMB NEAR 20/1 LATE SAT NIGHT WITH THE
ARRIVAL OF THE COLDER AIR...ADDITIONAL ENHANCEMENT AMOUNTS IN THE 1
TO 4 INCH RANGE WOULD KEEP OVERALL TOTAL GENERALLY IN THE ADVISORY
RANGE OR BELOW 8 INCHES. BELIEVE ONLY A FEW LOCATIONS OVER THE HURON
MTNS COULD APPROACH WARNING CRITERIA OF 8 INCHES DUE TO MORE
PROLONGED FAVORABLE UPSLOPE NE FLOW. IN ADDITION...NRLY WINDS
GUSTING TO 25 TO 30 MPH IN OPEN AREAS NEAR THE LAKE SHORES WILL
PRODUCE BLOWING AND DRIFTING SNOW.
SUN...A TRANSITION FROM LAKE ENHANCED TO PURE LES IS EXPECTED AS THE
DEEPER MOISTURE AND MID-LVL Q-VECT CONV DEPARTS E WITH MOVEMENT OF
LOW PRESSURE SYSTEM. 850 MB TEMPS DROPPING INTO THE -19C TO -22C
RANGE BY 18Z AS 850-700 MB MOISTURE STILL LINGERS OVER AREA WILL
FAVOR CONTINUED MODERATE TO HEAVY LES...ESPECIALLY FOR LOCATIONS
FAVORED BY NRLY UPSLOPE FLOW. EXPECT LES RATES TO GRADUALLY DIMINISH
IN THE AFTERNOON AS WINDS BACK AND INVERSION HEIGHTS DROP TO AROUND
5K FT. WITH EXPECTED SNOWFALL AMOUNTS GENERALLY IN HIGH END OF THE
ADVISORY RANGE...WILL CONTINUE WITH A SPS TO HIGHLIGHT THE POTENTIAL
FOR SIGNIFICANT SNOWFALL. EXPECT THE GREATEST TOTAL ACCUMULATIONS
FROM IRONWOOD THROUGH THE PORCUPINE MOUNTAINS TO ROCKLAND IN THE
WEST AND FROM HERMAN THROUGH THE HURON MOUNTAINS TO NEGAUNEE OVER
THE NORTH CENTRAL. A FEW FAVORED HIGHER TERRAIN LOCATIONS COULD
APPROACH 10 TO 12 INCHES THROUGH THE EVENT.
SUN NIGHT...ENHANCED LOW-LEVEL CONVERGENCE FROM DEVELOPING LAND
BREEZES COULD FAVOR AREAS EAST OF MQT FOR ADDITIONAL MODERATE LES
ACCUMULATION. NAM BUFR SNDGS SHOW FAVORABLE PLACEMENT OF DGZ WITHIN
BEST MODEL OMEGA OF CONVECTIVE BOUNDARY LAYER SO GOOD SNOW GROWTH
AND FLUFFY LES ACCUMULATION EXPECTED. WOULD NOT BE SURPRISED TO SEE
ADVISORY SNOWFALL OF 4 INCHES OR MORE OVER PORTIONS OF ERN
ALGER...NRN SCHOOLCRAFT AND NW LUCE COUNTY WHERE MODELS SHOW BEST
LOW-LVL CONVERGENCE.
MON-WED...AS THE POLAR VORTEX GRADUALLY SHIFTS FROM HUDSON BAY TO
NRN QUEBEC...VERY COLD ARCTIC AIR WILL DOMINATE THE WRN GREAT LAKES.
WITH 850 MB TEMPS DROPPING INTO THE -25C TO -29C RANGE...LES WILL
PERSIST FOR LOCATIONS FAVORED BY NW TO W FLOW. AS TO BE EXPECTED
MODELS STILL SHOWING DIFFERENCES WITH TIMING OF SHORTWAVES MOVING
THROUGH THE REGION AND THUS ACCOMPANYING WIND SHIFTS. THERE MAY
BE PERIODS WHERE THE WINDS ARE LIGHT ENOUGH FOR LAKE INDUCED
TROUGHING TO DOMINATE THE LOW LEVEL FLOW. THE COLD AIRMASS WILL ALSO
FAVOR SMALL SNOWFLAKES THAT WILL LIMIT OVERALL ACCUMULATIONS BUT
STILL LEAD TO LOW VISIBILITIES. OUTSIDE OF THE LES...SEVERE WIND
CHILLS AT TIMES ASE VALUES DROP INTO THE -20 TO -35 RANGE.
THU AND FRI...MODELS SHOW SIGNS OF TRENDING TOWARD LESS AMPLIFIED
PATTERN BY THE END OF THE WEEK WITH WAA DEVELOPING. SFC HIGH
PRESSURE OVER THE REGION SHOULD ENSURE MOSTLY DRY CONDITIONS ON
THURSDAY...EXCEPT FOR SOME LINGERING LIGHT WEST FLOW LES ALONG LAKE
SUPERIOR. EXPECT HIGH TEMPS THU TO REBOUND BACK INTO THE DOUBLE
DIGITS ABOVE ZERO. STRONGER WAA ON FRIDAY AHEAD OF THE NEXT
ADVANCING CLIPPER SYSTEM MAY ALLOW FOR HIGH TEMPS TO CLIMB BACK INTO
THE 20S ESPECIALLY OVER THE EAST HALF OF THE FCST AREA. BOTH THE
ECMWF AND GFS DEVELOP AREA OF LIGHT SNOW NORTH OF LAKE SUPERIOR IN
WAA/ISENTROPIC ASCENT AND SPREAD THIS SNOW ACROSS MAINLY THE EASTERN
AND NORTH CENTRAL FCST AREA. WILL INCLUDE HIGHER CHC POPS IN FRI
FCST FOR THIS SNOW POTENTIAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1156 PM EST FRI DEC 27 2013
THE PASSAGE OF A LOW PRESSURE TROUGH SHOULD RESULT IN A WSHFT TO THE
WNW AND THE ARRIVAL OF SOME SHALLOW MSTR. MVFR CONDITIONS WL BE THE
RESULT EXCEPT AT CMX...WHERE MORE PRONOUNCED UPSLOPE COMPONENT WL
BRING ABOUT IFR CONDITIONS WHICH WILL LAST THROUGH THE FORECAST
PERIOD. THERE COULD ALSO BE SOME FLURRIES AND DZ AT IWD AND
ESPECIALLY CMX. MVFR CONDITIONS WILL PERSIST AT IWD UNTIL UPSLOPE NE
WINDS ARRIVE SAT EVENING WHEN CONDITIONS WILL THEN GO TO IFR. AT
SAW...MVFR CONDITIONS WILL LAST INTO SAT AFTERNOON BEFORE IFR
UPSLOPE CLOUDS ARRIVE WHICH WILL LAST INTO SAT EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 507 PM EST FRI DEC 27 2013
EXPECT SW WINDS UP TO 30 KTS AND SOME FREEZING SPRAY THIS EVENING TO
DIMINISH WITH ARRIVAL OF WEAKER PRES GRADIENT ACCOMPANYING A LO PRES
PASSAGE. STRONGER N WINDS AND SOME FREEZING SPRAY WILL REDEVELOP ON
SAT FOLLOWING THE PASSAGE OF ANOTHER COLD FRONT AND AS ARCTIC AIR
SURGES S IN ADVANCE OF HI PRES BUILDING INTO SCENTRAL CANADA. AS
ARCTIC AIR FLOWS S INTO THE AREA BEHIND FRONT AND NE GRADIENT
TIGHTENS BEHIND LOW PASSING TO SOUTH LOOK FOR A PERIOD OF GALES TO
DEVELOP OVER THE WEST AND NCNTRL SAT NIGHT SO HAVE ISSUED A GALE
WATCH FOR THIS POTENTIAL. OTHERWISE NE WINDS TO 30KT WILL BE COMMON
SAT NIGHT FOR THE REST OF THE LAKE BACKING TO THE NORTH ON SUNDAY.
HEAVY FREEZING SPRAY IS STILL EXPECTED OVER MUCH OF THE LAKE SAT
NIGHT INTO MONDAY. IT APPEARS THAT THE ARCTIC AIR WILL SETTLE INTO
THE UPPER LAKES FOR AN EXTENDED STAY MUCH OF NEXT WEEK...ALTHOUGH NO
GALES APPEAR EVIDENT AT THIS POINT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 1 AM SUNDAY TO 7 AM EST MONDAY
FOR LSZ265-267.
HEAVY FREEZING SPRAY WARNING FROM 1 AM SUNDAY TO 7 PM EST MONDAY
FOR LSZ266.
GALE WATCH FROM SATURDAY EVENING THROUGH SUNDAY MORNING FOR
LSZ162-263-264.
HEAVY FREEZING SPRAY WARNING FROM 7 PM EST /6 PM CST/ SATURDAY
TO 1 AM EST /MIDNIGHT CST/ MONDAY FOR LSZ162-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...VOSS
AVIATION...07
MARINE...VOSS/KC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
337 PM CST SAT DEC 28 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 337 PM CST SAT DEC 28 2013
...A BRIEF BUT POTENT BLAST OF ARCTIC AIR AS TEMPS PLUNGE FROM
TODAY/S NEAR RECORD WARMTH...
ALOFT: PROGRESSIVE NW REMAINS IN PLACE. AN EMBEDDED POSITIVE-TILT
TROF WAS OVER THE NRN ROCKIES. THIS TROF WILL MOVE THRU HERE
TOMORROW...WITH NW FLOW TO FOLLOW.
SURFACE: LOW PRES HAS BEEN MIGRATING E ALONG AN ARCTIC COLD
FRONT...OUT OF THE DAKOTAS FROM THIS MORNING AND WAS OVER SWRN MN
AT 20Z. THE FRONT WAS SURGING S IN ITS WAKE AND IR SATELLITE
IMAGERY SUGGESTS THAT IT/S THRU THE SANDHILLS AND EXTENDS FROM
ALBION-LOUP CITY-LEXINGTON AT 20Z. THE FRONT SHOULD BE THRU THE
FCST AREA IN 6 HRS OR LESS...EXITING INTO CNTRL KS BY 9PM. STRONG
ARCTIC HIGH PRES BUILDS IN TONIGHT AS IT SLIDES INTO THE NRN
PLAINS. IT WILL WEAKEN TOMORROW AS IT CONTINUES DOWN THE MO RIVER
VALLEY.
UPDATED ADVISORY/HAZARDOUS WX OUTLOOK HAVE POSTED. GOSPER/DAWSON/
PHELPS COUNTIES ARE NOW INCLUDED. THE END TIME HAS ALSO BEEN MOVED
UP TO 3 AM...BUT ADVISORY COULD END UP BEING TERMINATED AS EARLY
AS 12 AM.
REST OF THIS AFTERNOON: WE PUT THE FINISHING TOUCHES ON ANOTHER
VERY NICE DAY FOR LATE DEC WITH NEAR-RECORD MUCH ABOVE NORMAL
WARMTH.
A CHECK OF GRI ASOS AT 335 PM VIA MODEM SHOWS A HIGH OF 62F. THE
FRONT HAS MOVED THRU AND THE TEMP IS DOWN TO 59F. CAME WITHIN 2F
OF TYING THE RECORD HIGH /64 IN 2002/.
WE HAVE BEEN WATCHING IMPRESSIVE PRES GRADIENT OVER ND/SD/MT/WY
TODAY WITH EQUALLY IMPRESSIVE WINDS. PEAK GUSTS OF 45-52 KTS HAVE
BEEN COMMON. THERE IS A CORE OF 40-55 KT WINDS AT 850 MB
COINCIDENT WITH THESE WINDS. THE RAPID CITY 88D CONFIRMS ITS
PRESENCE.
EXPECT DOWNWARD TRANSFER IN VERY STEEP LAPSE RATES/COLD AIR
ADVECTION AS THIS JET CORE DROPS INTO THE FCST AREA.
THE STRONGEST WINDS WILL OCCUR IN THE 6-8 HRS IMMEDIATELY
FOLLOWING PASSAGE OF THE COLD FRONT /IE BEFORE MIDNIGHT/.
VALENTINE HAD A PEAK WIND OF 45 KTS AT 218 PM.
THE WINDIEST LOCATIONS WILL BE ALONG AND N OF HWY 92. RAP TIME-
HEIGHT CROSS SECTIONS SHOW 45 KTS DOWN TO 1K FT WITH A CORE OF 50
KTS DOWN TO 1800 FT FROM 9PM-12AM. 18Z NAM HAS 52 KTS BUT ONLY AS
LOW AS 2K FT 6PM-9PM. BOTTOM LINE...WOULD NOT BE SURPRISED TO SEE
G50-55 MPH IN THESE AREAS THIS EVE.
15Z SREF PROBABILITIES FOR MEAN WINDS 30 MPH OR GREATER ARE
HIGHEST OVER CNTRL NEB N INTO THE SANDHILLS 6PM-11PM. THIS IS
WHERE THE ADVISORY HAS THE BEST CHANCE OF VERIFYING.
TONIGHT: WINDY AND TURNING MUCH COLDER. BECOMING MOSTLY CLOUDY AS
THE 900-850 MB LAYER COOLS TO SATURATION. EXTENSIVE MID-HIGH
CLOUDS WILL ALSO INVADE. LOW TEMPS ROUGHLY 8F COLDER THAN NORMAL.
TOMORROW: DECREASING CLOUDS AND WINDS. TEMPS MUCH COLDER THAN
NORMAL /BY 15-20F/.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 332 PM CST SAT DEC 28 2013
A 1035MB SURFACE HIGH PRESSURE SYSTEM WILL BUILD SOUTH ALONG THE
MISSOURI RIVER SUNDAY EVENING...AND EXPECT TEMPERATURES WILL DROP
OFF RATHER QUICKLY FOR THE FIRST PART OF THE NIGHT. AS THE SFC
RIDGE AXIS WEAKENS AND SHIFTS EASTWARD SUNDAY NIGHT...RETURN FLOW
SETS UP AND THE AIRMASS BEGINS TO MODERATE AND TEMPERATURES SHOULD
TREND UP HEADING INTO MONDAY MORNING.
THE UPPER TROUGH AXIS WILL TRANSLATE EAST/NORTHEASTWARD FOR THE
FIRST PART OF THE WEEK...WHICH ALLOWS FOR A REBOUND IN
TEMPERATURES FOR OUR AREA AS HEIGHTS RISE BEHIND THE SYSTEM. THIS
BEING SAID IT IS IMPORTANT TO NOTE THAT THE COLD AIR IS NOT THAT
FAR AWAY AND IF THE BAROCLINIC ZONE SHIFTS FARTHER SOUTH AND
WEST...IT WILL BE ACROSS US AND TEMPS WILL BE COLDER. THE BIGGEST
CHANGE IN THE FORECAST COMES IN THE TUESDAY TIME FRAME AS SEVERAL
OF THE LATEST OPERATIONAL MODELS NO LONGER BACK A COLD FRONT AS
FAR SOUTH INTO SC NEBRASKA AS PREVIOUS RUNS. MODELS ARE IN PRETTY
GOOD AGREEMENT THAT THE COLD AIR AND STRATUS WILL BE ORIENTED
ACROSS SOUTH DAKOTA/NORTHERN IOWA AND PERHAPS FAR NORTHERN
NEBRASKA THROUGH THE DAY...ALTHOUGH A COLD FRONT DOES ADVANCE
SOUTH IN THE AFTN. HAVE RAISED TEMPERATURES FOR TUESDAY...BUT WILL
NEED TO MONITOR THERMAL AND CLOUD FIELDS CLOSELY AS THE 12Z ECMWF
REMAINS COLDER THAN GFS/GEM/NAM IN THIS TIME FRAME.
A COLD FRONT PUSHES SOUTH TUESDAY/NEW YEARS EVE NIGHT AND MODELS
ARE NOT OVERLY ROBUST IN GENERATING PCPN WITH THIS BUT DID
MAINTAIN SOME VERY LOW POPS FOR LIGHT SNOW ACROSS OUR NORTHEAST
ZONES. LIGHT WINTRY PCPN IS POSSIBLE ON WEDNESDAY/NEW YEARS DAY AS
A 120KT JET NOSES SOUTH ALONG THE ROCKIES/HIGH PLAINS REGION AND
DEEPENS A TROUGH ACROSS THE PLAINS AND UPPER MIDWEST. COLDER AIR
ADVECTS SOUTH AND A BAND OF FRONTOGENETIC SNOWFALL IS POSSIBLE
INTO WEDNESDAY NIGHT.
THURSDAY WILL BE THE TRANSITION DAY BETWEEN THE COLD AIR AT THE
MIDDLE OF THE WEEK AND A WARMING TREND FOR THE END OF THE WEEK.
THE UPPER TROUGH AND COLD AIR ONCE AGAIN SLIDE EAST THURSDAY WITH
HEIGHTS RISING/MODERATING TEMPS IN ITS WAKE. FRIDAY IS SHAPING UP
TO BE MILD AGAIN WITH ABOVE NORMAL TEMPS IN SUBTLE RIDGING ALOFT.
SATURDAY TEMPS WILL BE DEPENDENT ON COLD FRONTAL TIMING WITH THE
GFS QUICKER WITH THE FRONT PASSAGE THAN THE ECMWF...AND GIVEN
MODEL DIFFERENCES DID NOT DEVIATE MUCH FROM INIT FOR DAY 7.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1207 PM CST SAT DEC 28 2013
THIS AFTERNOON: VFR WITH JUST A FEW SHREDS OF CIRRUS ON THE NW
HORIZON. SW WINDS WILL HOLD STEADY AROUND 15 KTS AND THEN SHIFT TO
W AS A PRE-FRONTAL TROF MOVES THRU. THE ARCTIC FRONT SHOULD ARRIVE
AROUND 22Z WITH A WSHFT TO NW. WINDS WILL GUST 25-30 KTS.
CONFIDENCE: HIGH
TONIGHT: NW WINDS WILL BECOME NNW AND GUST 35-40 KTS. THERE IS
POTENTIAL FOR A ONE-TIME TO NEAR G43 KTS. SUSTAINED WINDS WILL
AVERAGE 25-30 KTS PRIOR TO MIDNIGHT...THEN DROP TO 20-25 KTS. MVFR
CIGS SHOULD DEVELOP WITHIN AN HOUR OR TWO OF 00Z. CONFIDENCE: HIGH
SUN THRU 18Z: MVFR CIGS SHOULD DECREASE TO SCT. NNW WINDS CONT TO
DIMINISH. CONFIDENCE: HIGH
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 3 AM CST SUNDAY FOR NEZ039>041-046>049-
060>064-072>077.
KS...NONE.
&&
$$
SHORT TERM...HALBLAUB 337
LONG TERM...FAY
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
333 PM CST SAT DEC 28 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 331 PM CST SAT DEC 28 2013
THE WIND ADVISORY LOOKS GOOD FOR MOST OF WESTERN AND NORTH CENTRAL
NEBRASKA TONIGHT. HAVE EXPANDED TO INCLUDE A BIT MORE OF SOUTHWEST
NEBRASKA...WHERE BOTH THE 18Z NAM AND RAP MODELS INDICATE A CORE OF
STRONGER WINDS JUST OFF THE SURFACE MOVING ACROSS THIS EVENING.
WINDS WILL DIMINISH ACROSS THE ENTIRE AREA LATE TONIGHT...BUT REMAIN
STRONG ENOUGH THAT WHEN COMBINED WITH TEMPERATURES NEAR OR JUST
BELOW ZERO ACROSS NORTHERN NEBRASKA...WIND CHILLS WILL REACH
ADVISORY CRITERIA. SO...HAVE ISSUED A WIND CHILL ADVISORY LATE
TONIGHT INTO SUNDAY MORNING FOR NORTHERN NEBRASKA.
STILL SOME CONCERN FOR A BIT OF FREEZING DRIZZLE ACROSS EASTERN
PORTIONS OF NORTH CENTRAL NEBRASKA THROUGH MID EVENING. BUFKIT
SOUNDING DATA JUST EAST OF THE ONEILL AREA SHOWS THE POTENTIAL UNTIL
MID EVENING...WHEN THE SATURATED LOWER LAYER DROPS QUICKLY BELOW
-10C. OTHERWISE THERE IS SOME POTENTIAL FOR A FEW SNOW SHOWERS OR
FLURRIES ELSEWHERE. HRRR MODEL HAS BEEN KEYING ON FLURRY POTENTIAL
ACROSS SOUTHWEST NEBRASKA IN AN AREA OF ENHANCED MID LEVEL
FRONTOGENESIS AND QG FORCING.
HIGH PRESSURE QUICKLY BUILDS INTO THE AREA SUNDAY...WITH WINDS
NEARLY CALM BY AFTERNOON. IT WILL BE COLD THOUGH WITH ARCTIC AIR IN
PLACE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 331 PM CST SAT DEC 28 2013
A PROGRESSIVE PATTERN CONTINUES IN THE NORTHWEST FLOW ACROSS THE
PLAINS THROUGH MOST OF NEXT WEEK.
THE NEXT STORM SYSTEM FROM THE CANADIAN ROCKIES COMES THROUGH
WESTERN NEBRASKA TUESDAY. THERE IS SOME ISENTROPIC LIFT INDICATED IN
THE 290-300K LAYER...BUT MOISTURE IS LACKING EVERYWHERE EXCEPT THE
AREA NORTH AND WEST OF ONEILL.
ANOTHER PULSE IS ON THE WAY FOR TUESDAY NIGHT THROUGH WEDNESDAY.
THAT ONE ALSO SHOWS ISENTROPIC LIFT IN THE 290-300K LAYER WITH SOME
FRONTOGENETIC ENHANCEMENT IN CENTRAL AND NORTH CENTRAL NEBRASKA.
THOUGH MOISTURE IS A LITTLE BETTER...IT IS STILL FAIRLY DRY IN THE
LOWER LAYERS. ALSO...THERE ARE SIGNIFICANT DIFFERENCES IN THE
LOCATIONS INDICATED IN THE THREE MEDIUM/LONG RANGE MODELS (THE
ECMWF...GEMNH AND US GFS)...SO WE WILL KEEP THE PROBABILITY LOW FOR
NOW.
ANOTHER SYSTEM IS EXPECTED TO DEVELOP IN COLORADO FRIDAY OR
SATURDAY...BUT THE UNCERTAINTY WITH THAT ONE IS HIGH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1228 PM CST SAT DEC 28 2013
STRONG ARCTIC COLD FRONT MOVING SOUTHEAST ACROSS THE AREA THIS
AFTERNOON. DETERIORATING CONDITIONS EXPECTED ACROSS NORTHERN NEBRASKA
WITH POSSIBLE MVFR CEILINGS AND PATCHY FREEZING DRIZZLE. OTHERWISE
GUSTY WINDS WITH NORTHWEST WINDS 25 TO 35 KTS. FARTHER SOUTH
ACROSS SOUTHWEST NEBRASKA...WINDS WILL INCREASE TO 15 TO 30 KTS.
AT THIS TIME ANY FREEZING DRIZZLE AND LOWER CEILINGS SHOULD REMAIN
NORTH OF SOUTHWEST NEBRASKA.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL MIDNIGHT CST /11 PM MST/ TONIGHT FOR NEZ005-
006-008-009-022>026-035>037-056-057-059-071-094.
WIND CHILL ADVISORY FROM 3 AM CST /2 AM MST/ TO 9 AM CST /8 AM
MST/ SUNDAY FOR NEZ004>010-023>029-094.
WIND ADVISORY UNTIL 3 AM CST SUNDAY FOR NEZ007-010-027>029-038.
&&
$$
SHORT TERM...TAYLOR
LONG TERM...SPRINGER
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS HASTINGS NE
332 PM CST SAT DEC 28 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 332 PM CST SAT DEC 28 2013
...A BRIEF BUT POTENT BLAST OF ARCTIC AIR AS TEMPS PLUNGE FROM
TODAY/S NEAR RECORD WARMTH...
ALOFT: PROGRESSIVE NW REMAINS IN PLACE. AN EMBEDDED POSITIVE-TILT
TROF WAS OVER THE NRN ROCKIES. THIS TROF WILL MOVE THRU HERE
TOMORROW...WITH NW FLOW TO FOLLOW.
SURFACE: LOW PRES HAS BEEN MIGRATING E ALONG AN ARCTIC COLD
FRONT...OUT OF THE DAKOTAS FROM THIS MORNING AND WAS OVER SWRN MN
AT 20Z. THE FRONT WAS SURGING S IN ITS WAKE AND IR SATELLITE
IMAGERY SUGGESTS THAT IT/S THRU THE SANDHILLS AND EXTENDS FROM
ALBION-LOUP CITY-LEXINGTON AT 20Z. THE FRONT SHOULD BE THRU THE
FCST AREA IN 6 HRS OR LESS...EXITING INTO CNTRL KS BY 9PM. STRONG
ARCTIC HIGH PRES BUILDS IN TONIGHT AS IT SLIDES INTO THE NRN
PLAINS. IT WILL WEAKEN TOMORROW AS IT CONTINUES DOWN THE MO RIVER
VALLEY.
UPDATED ADVISORY/HAZARDOUS WX OUTLOOK HAVE POSTED. GOSPER/DAWSON/
PHELPS COUNTIES ARE NOW INCLUDED. THE END TIME HAS ALSO BEEN MOVED
UP TO 3 AM...BUT ADVISORY COULD END UP BEING TERMINATED AS EARLY
AS 12 AM.
REST OF THIS AFTERNOON: WE PUT THE FINISHING TOUCHES ON ANOTHER
VERY NICE DAY FOR LATE DEC WITH NEAR-RECORD MUCH ABOVE NORMAL
WARMTH.
WE HAVE BEEN WATCHING IMPRESSIVE PRES GRADIENT OVER ND/SD/MT/WY
TODAY WITH EQUALLY IMPRESSIVE WINDS. PEAK GUSTS OF 45-52 KTS HAVE
BEEN COMMON. THERE IS A CORE OF 40-55 KT WINDS AT 850 MB
COINCIDENT WITH THESE WINDS. THE RAPID CITY 88D CONFIRMS ITS
PRESENCE.
EXPECT DOWNWARD TRANSFER IN VERY STEEP LAPSE RATES/COLD AIR
ADVECTION AS THIS JET CORE DROPS INTO THE FCST AREA.
THE STRONGEST WINDS WILL OCCUR IN THE 6-8 HRS IMMEDIATELY
FOLLOWING PASSAGE OF THE COLD FRONT /IE BEFORE MIDNIGHT/.
VALENTINE HAD A PEAK WIND OF 45 KTS AT 218 PM.
THE WINDIEST LOCATIONS WILL BE ALONG AND N OF HWY 92. RAP TIME-
HEIGHT CROSS SECTIONS SHOW 45 KTS DOWN TO 1K FT WITH A CORE OF 50
KTS DOWN TO 1800 FT FROM 9PM-12AM. 18Z NAM HAS 52 KTS BUT ONLY AS
LOW AS 2K FT 6PM-9PM. BOTTOM LINE...WOULD NOT BE SURPRISED TO SEE
G50-55 MPH IN THESE AREAS THIS EVE.
15Z SREF PROBABILITIES FOR MEAN WINDS 30 MPH OR GREATER ARE
HIGHEST OVER CNTRL NEB N INTO THE SANDHILLS 6PM-11PM. THIS IS
WHERE THE ADVISORY HAS THE BEST CHANCE OF VERIFYING.
TONIGHT: WINDY AND TURNING MUCH COLDER. BECOMING MOSTLY CLOUDY AS
THE 900-850 MB LAYER COOLS TO SATURATION. EXTENSIVE MID-HIGH
CLOUDS WILL ALSO INVADE. LOW TEMPS ROUGHLY 8F COLDER THAN NORMAL.
TOMORROW: DECREASING CLOUDS AND WINDS. TEMPS MUCH COLDER THAN
NORMAL /BY 15-20F/.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 332 PM CST SAT DEC 28 2013
A 1035MB SURFACE HIGH PRESSURE SYSTEM WILL BUILD SOUTH ALONG THE
MISSOURI RIVER SUNDAY EVENING...AND EXPECT TEMPERATURES WILL DROP
OFF RATHER QUICKLY FOR THE FIRST PART OF THE NIGHT. AS THE SFC
RIDGE AXIS WEAKENS AND SHIFTS EASTWARD SUNDAY NIGHT...RETURN FLOW
SETS UP AND THE AIRMASS BEGINS TO MODERATE AND TEMPERATURES SHOULD
TREND UP HEADING INTO MONDAY MORNING.
THE UPPER TROUGH AXIS WILL TRANSLATE EAST/NORTHEASTWARD FOR THE
FIRST PART OF THE WEEK...WHICH ALLOWS FOR A REBOUND IN
TEMPERATURES FOR OUR AREA AS HEIGHTS RISE BEHIND THE SYSTEM. THIS
BEING SAID IT IS IMPORTANT TO NOTE THAT THE COLD AIR IS NOT THAT
FAR AWAY AND IF THE BAROCLINIC ZONE SHIFTS FARTHER SOUTH AND
WEST...IT WILL BE ACROSS US AND TEMPS WILL BE COLDER. THE BIGGEST
CHANGE IN THE FORECAST COMES IN THE TUESDAY TIME FRAME AS SEVERAL
OF THE LATEST OPERATIONAL MODELS NO LONGER BACK A COLD FRONT AS
FAR SOUTH INTO SC NEBRASKA AS PREVIOUS RUNS. MODELS ARE IN PRETTY
GOOD AGREEMENT THAT THE COLD AIR AND STRATUS WILL BE ORIENTED
ACROSS SOUTH DAKOTA/NORTHERN IOWA AND PERHAPS FAR NORTHERN
NEBRASKA THROUGH THE DAY...ALTHOUGH A COLD FRONT DOES ADVANCE
SOUTH IN THE AFTN. HAVE RAISED TEMPERATURES FOR TUESDAY...BUT WILL
NEED TO MONITOR THERMAL AND CLOUD FIELDS CLOSELY AS THE 12Z ECMWF
REMAINS COLDER THAN GFS/GEM/NAM IN THIS TIME FRAME.
A COLD FRONT PUSHES SOUTH TUESDAY/NEW YEARS EVE NIGHT AND MODELS
ARE NOT OVERLY ROBUST IN GENERATING PCPN WITH THIS BUT DID
MAINTAIN SOME VERY LOW POPS FOR LIGHT SNOW ACROSS OUR NORTHEAST
ZONES. LIGHT WINTRY PCPN IS POSSIBLE ON WEDNESDAY/NEW YEARS DAY AS
A 120KT JET NOSES SOUTH ALONG THE ROCKIES/HIGH PLAINS REGION AND
DEEPENS A TROUGH ACROSS THE PLAINS AND UPPER MIDWEST. COLDER AIR
ADVECTS SOUTH AND A BAND OF FRONTOGENETIC SNOWFALL IS POSSIBLE
INTO WEDNESDAY NIGHT.
THURSDAY WILL BE THE TRANSITION DAY BETWEEN THE COLD AIR AT THE
MIDDLE OF THE WEEK AND A WARMING TREND FOR THE END OF THE WEEK.
THE UPPER TROUGH AND COLD AIR ONCE AGAIN SLIDE EAST THURSDAY WITH
HEIGHTS RISING/MODERATING TEMPS IN ITS WAKE. FRIDAY IS SHAPING UP
TO BE MILD AGAIN WITH ABOVE NORMAL TEMPS IN SUBTLE RIDGING ALOFT.
SATURDAY TEMPS WILL BE DEPENDENT ON COLD FRONTAL TIMING WITH THE
GFS QUICKER WITH THE FRONT PASSAGE THAN THE ECMWF...AND GIVEN
MODEL DIFFERENCES DID NOT DEVIATE MUCH FROM INIT FOR DAY 7.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1207 PM CST SAT DEC 28 2013
THIS AFTERNOON: VFR WITH JUST A FEW SHREDS OF CIRRUS ON THE NW
HORIZON. SW WINDS WILL HOLD STEADY AROUND 15 KTS AND THEN SHIFT TO
W AS A PRE-FRONTAL TROF MOVES THRU. THE ARCTIC FRONT SHOULD ARRIVE
AROUND 22Z WITH A WSHFT TO NW. WINDS WILL GUST 25-30 KTS.
CONFIDENCE: HIGH
TONIGHT: NW WINDS WILL BECOME NNW AND GUST 35-40 KTS. THERE IS
POTENTIAL FOR A ONE-TIME TO NEAR G43 KTS. SUSTAINED WINDS WILL
AVERAGE 25-30 KTS PRIOR TO MIDNIGHT...THEN DROP TO 20-25 KTS. MVFR
CIGS SHOULD DEVELOP WITHIN AN HOUR OR TWO OF 00Z. CONFIDENCE: HIGH
SUN THRU 18Z: MVFR CIGS SHOULD DECREASE TO SCT. NNW WINDS CONT TO
DIMINISH. CONFIDENCE: HIGH
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 3 AM CST SUNDAY FOR NEZ039>041-046>049-
060>064-072>077.
KS...NONE.
&&
$$
SHORT TERM...HALBLAUB
LONG TERM...FAY
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1232 PM CST SAT DEC 28 2013
.UPDATE...
ISSUED AT 1212 PM CST SAT DEC 28 2013
HAVE EXPANDED THE WIND ADVISORY TO INCLUDE THE WESTERN SANDHILLS
INTO THE SOUTHERN PANHANDLE. VERY STRONG PRESSURE RISES WILL SLIDE
ACROSS THE AREA THIS AFTERNOON...WITH BOTH THE RAP AND NAM MODELS
INDICATING 500 METER WIND SPEEDS APPROACHING 40 KTS. IT IS
POSSIBLE THAT NEAR HIGH WIND WARNING WIND SPEEDS COULD BE REACHED
ACROSS NORTH CENTRAL NEBRASKA FROM MID AFTERNOON THROUGH EARLY
EVENING...AND WILL MONITOR THIS CLOSELY. HAVE SEEN 65 MPH WIND
GUSTS LATE THIS MORNING ACROSS NORTHWEST SOUTH DAKOTA. STILL
COULD SEE SOME PATCHY FREEZING DRIZZLE...AS SOUNDINGS CONTINUE TO
INDICATE A NARROW WINDOW FOR THIS POTENTIAL ACROSS NORTHERN
NEBRASKA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM CST SAT DEC 28 2013
MODELS IN FAIR AGREEMENT WITH TIMING OF FRONT AND HAVE USED A
BLEND. WINDS AND PRECIPITATION TYPE WILL BE NEAR TERM CONCERNS.
SURFACE LOW CENTERED NEAR CANADIAN EASTERN MONTANA BORDER WITH
SURFACE TROUGH INTO THE WESTERN NEBRASKA PANHANDLE INTO NORTHEAST
COLORADO. COLD FRONT ALONG MONTANA CANADIAN BORDER. 3HR PRESSURE
CHANGES HAVE A STRONG 10MB RISE OVER NORTH CENTRAL MONTANA WITH
-3MB PRESSURE FALLS INTO THE DAKOTAS. LEADING EDGE OF COLD FRONT
TO DROP THROUGH MOST OF THE CWA BY 18Z TODAY. HIGH TEMPERATURES
EARLY WITH RAPIDLY FALLING TEMPERATURES THROUGH THE AFTERNOON.
HAVE TRENDED LOWER WITH HIGHS WITH UPPER 30S NORTHWEST AND AROUND
50 TO THE SOUTHWEST. THESE MAY HAVE TO BE TRENDED DOWNWARD. TIGHT
PRESSURE GRADIENT AND WIND ADVISORY WINDS DEVELOP 18Z THROUGH
MIDNIGHT. WILL CONTINUE GOING WIND ADVISORY. THIS AFTERNOON TIME
HEIGHTS OVER NORTHERN NEBRASKA HAVE INCREASING LOW LEVEL RH WITH
WEAK LIFT AND DRY LAYER 800MB AND ABOVE. BUFR SOUNDINGS
INDICATIVE OF FREEZING DRIZZLE. HAVE CUT BACK ON START OF
PRECIPITATION BUT CARRIED LIGHT FREEZING DRIZZLE OR LIGHT SNOW
SHOWERS. AFTER 00Z CARRIED SNOW SHOWERS. MINIMAL CHANCES
GENERALLY NORTH OF HIGHWAY 2. WITH PARTIAL CLEARING TONIGHT
TEMPERATURES TO DROP SIGNIFICANTLY WITH COLDER AIR OVER NORTHWEST
WHERE THERE IS STILL SOME SNOW COVER AS 1040MB HIGH NOSES INTO
NORTHERN NEBRASKA. STRONG NORTHWEST WINDS AND SOME CLOUD COVER
MAY KEEP TEMPERATURES FROM REACHING THEIR FULL POTENTIAL.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 333 AM CST SAT DEC 28 2013
SUNDAY MORNING THE ARCTIC HIGH PRESSURE WILL STRETCH FROM THE
NORTHERN PLAINS TO THE CENTRAL PLAINS. RESULTING IN MUCH COOLER
AIR ACROSS THE REGION. LATE IN THE DAY...AS THE HIGH PUSHES
EAST...850 MB TEMPS ON THE INCREASE. THIS WILL ALLOW FOR FAR SW
TO REBOUND CLOSE TO 30...OTHERWISE TEENS ACROSS N CENTRAL WITH
20S ELSEWHERE. THE HIGH WILL ALSO BRING DRY CONDITIONS. WAA
CONTINUES SUNDAY NIGHT AS THE HIGH CONTINUES TO DRIFT SE.
OVERNIGHT TEMPS STILL CHILLY...SINGLE DIGITS AND TEENS AS MODELS
IN GOOD AGREEMENT WITH THE BL STILL DECOUPLING.
EARLY NEXT WEEK THE MAIN FLOW IS NW ACROSS THE HIGH PLAINS. A
COUPLE OF CLIPPERS ARE EXPECTED TO QUICKLY MOVE ACROSS THE AREA.
CLOUDS ARE EXPECTED WITH EACH WAVE...HOWEVER UNSURE ON PRECIP.
MODELS INDICATE TOP DOWN SATURATION AND A SLOWLY INCREASING LOW
LEVEL MOISTURE FIELD WITH EACH PASSING WAVE. PRECIPITABLE WATERS
MONDAY MORNING START OUT NEAR THE 50 PERCENTILE /0.30 INCHES/ AND
INCREASE TO ABOVE THE 75 PERCENTILE /AROUND 0.45 INCHES/ BY
TUESDAY AFTERNOON/EVENING. WHILE LIFT IS LIMITED OVER THE CWA
WITH THE BETTER LIFT TO THE NORTH ACROSS S DAKOTA...SOME MODEL
AGREEMENT TUES/TUES NIGHT FOR GETTING SOME SNOWFALL TO REACH THE
GROUND. ONE NOTE IS THE EC IS A LITTLE SLOWER...AND AN OUTLIER AT
THIS TIME...KEEPING THINGS DRY UNTIL WEDNESDAY.
TO START THE NEW YEAR...WED INTO FRIDAY...A SEASONAL TO
SEASONALLY WARM PERIOD AND DRY IS EXPECTED...ALTHOUGH LESS
CONFIDENCE DUE TO THE EC ON WED. EXPECTING THE RIDGE IN THE WEST
TO AMPLIFY WITH HIGHS WARMING BACK INTO THE 40S AND EVEN A FEW
50S BY FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1228 PM CST SAT DEC 28 2013
STRONG ARCTIC COLD FRONT MOVING SOUTHEAST ACROSS THE AREA THIS
AFTERNOON. DETERIORATING CONDITIONS EXPECTED ACROSS NORTHERN NEBRASKA
WITH POSSIBLE MVFR CEILINGS AND PATCHY FREEZING DRIZZLE. OTHERWISE
GUSTY WINDS WITH NORTHWEST WINDS 25 TO 35 KTS. FARTHER SOUTH
ACROSS SOUTHWEST NEBRASKA...WINDS WILL INCREASE TO 15 TO 30 KTS.
AT THIS TIME ANY FREEZING DRIZZLE AND LOWER CEILINGS SHOULD REMAIN
NORTH OF SOUTHWEST NEBRASKA.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL MIDNIGHT CST /11 PM MST/ TONIGHT FOR NEZ005-
006-008-009-022>026-035>037-056-057-094.
WIND ADVISORY UNTIL 3 AM CST SUNDAY FOR NEZ007-010-027>029-038.
&&
$$
UPDATE...TAYLOR
SHORT TERM...POWER
LONG TERM...MASEK
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1226 PM CST SAT DEC 28 2013
.UPDATE...
ISSUED AT 1212 PM CST SAT DEC 28 2013
HAVE EXPANDED THE WIND ADVISORY TO INCLUDE THE WESTERN SANDHILLS
INTO THE SOUTHERN PANHANDLE. VERY STRONG PRESSURE RISES WILL SLIDE
ACROSS THE AREA THIS AFTERNOON...WITH BOTH THE RAP AND NAM MODELS
INDICATING 500 METER WIND SPEEDS APPROACHING 40 KTS. IT IS
POSSIBLE THAT NEAR HIGH WIND WARNING WIND SPEEDS COULD BE REACHED
ACROSS NORTH CENTRAL NEBRASKA FROM MID AFTERNOON THROUGH EARLY
EVENING...AND WILL MONITOR THIS CLOSELY. HAVE SEEN 65 MPH WIND
GUSTS LATE THIS MORNING ACROSS NORTHWEST SOUTH DAKOTA. STILL
COULD SEE SOME PATCHY FREEZING DRIZZLE...AS SOUNDINGS CONTINUE TO
INDICATE A NARROW WINDOW FOR THIS POTENTIAL ACROSS NORTHERN
NEBRASKA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM CST SAT DEC 28 2013
MODELS IN FAIR AGREEMENT WITH TIMING OF FRONT AND HAVE USED A
BLEND. WINDS AND PRECIPITATION TYPE WILL BE NEAR TERM CONCERNS.
SURFACE LOW CENTERED NEAR CANADIAN EASTERN MONTANA BORDER WITH
SURFACE TROUGH INTO THE WESTERN NEBRASKA PANHANDLE INTO NORTHEAST
COLORADO. COLD FRONT ALONG MONTANA CANADIAN BORDER. 3HR PRESSURE
CHANGES HAVE A STRONG 10MB RISE OVER NORTH CENTRAL MONTANA WITH
-3MB PRESSURE FALLS INTO THE DAKOTAS. LEADING EDGE OF COLD FRONT
TO DROP THROUGH MOST OF THE CWA BY 18Z TODAY. HIGH TEMPERATURES
EARLY WITH RAPIDLY FALLING TEMPERATURES THROUGH THE AFTERNOON.
HAVE TRENDED LOWER WITH HIGHS WITH UPPER 30S NORTHWEST AND AROUND
50 TO THE SOUTHWEST. THESE MAY HAVE TO BE TRENDED DOWNWARD. TIGHT
PRESSURE GRADIENT AND WIND ADVISORY WINDS DEVELOP 18Z THROUGH
MIDNIGHT. WILL CONTINUE GOING WIND ADVISORY. THIS AFTERNOON TIME
HEIGHTS OVER NORTHERN NEBRASKA HAVE INCREASING LOW LEVEL RH WITH
WEAK LIFT AND DRY LAYER 800MB AND ABOVE. BUFR SOUNDINGS
INDICATIVE OF FREEZING DRIZZLE. HAVE CUT BACK ON START OF
PRECIPITATION BUT CARRIED LIGHT FREEZING DRIZZLE OR LIGHT SNOW
SHOWERS. AFTER 00Z CARRIED SNOW SHOWERS. MINIMAL CHANCES
GENERALLY NORTH OF HIGHWAY 2. WITH PARTIAL CLEARING TONIGHT
TEMPERATURES TO DROP SIGNIFICANTLY WITH COLDER AIR OVER NORTHWEST
WHERE THERE IS STILL SOME SNOW COVER AS 1040MB HIGH NOSES INTO
NORTHERN NEBRASKA. STRONG NORTHWEST WINDS AND SOME CLOUD COVER
MAY KEEP TEMPERATURES FROM REACHING THEIR FULL POTENTIAL.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 333 AM CST SAT DEC 28 2013
SUNDAY MORNING THE ARCTIC HIGH PRESSURE WILL STRETCH FROM THE
NORTHERN PLAINS TO THE CENTRAL PLAINS. RESULTING IN MUCH COOLER
AIR ACROSS THE REGION. LATE IN THE DAY...AS THE HIGH PUSHES
EAST...850 MB TEMPS ON THE INCREASE. THIS WILL ALLOW FOR FAR SW
TO REBOUND CLOSE TO 30...OTHERWISE TEENS ACROSS N CENTRAL WITH
20S ELSEWHERE. THE HIGH WILL ALSO BRING DRY CONDITIONS. WAA
CONTINUES SUNDAY NIGHT AS THE HIGH CONTINUES TO DRIFT SE.
OVERNIGHT TEMPS STILL CHILLY...SINGLE DIGITS AND TEENS AS MODELS
IN GOOD AGREEMENT WITH THE BL STILL DECOUPLING.
EARLY NEXT WEEK THE MAIN FLOW IS NW ACROSS THE HIGH PLAINS. A
COUPLE OF CLIPPERS ARE EXPECTED TO QUICKLY MOVE ACROSS THE AREA.
CLOUDS ARE EXPECTED WITH EACH WAVE...HOWEVER UNSURE ON PRECIP.
MODELS INDICATE TOP DOWN SATURATION AND A SLOWLY INCREASING LOW
LEVEL MOISTURE FIELD WITH EACH PASSING WAVE. PRECIPITABLE WATERS
MONDAY MORNING START OUT NEAR THE 50 PERCENTILE /0.30 INCHES/ AND
INCREASE TO ABOVE THE 75 PERCENTILE /AROUND 0.45 INCHES/ BY
TUESDAY AFTERNOON/EVENING. WHILE LIFT IS LIMITED OVER THE CWA
WITH THE BETTER LIFT TO THE NORTH ACROSS S DAKOTA...SOME MODEL
AGREEMENT TUES/TUES NIGHT FOR GETTING SOME SNOWFALL TO REACH THE
GROUND. ONE NOTE IS THE EC IS A LITTLE SLOWER...AND AN OUTLIER AT
THIS TIME...KEEPING THINGS DRY UNTIL WEDNESDAY.
TO START THE NEW YEAR...WED INTO FRIDAY...A SEASONAL TO
SEASONALLY WARM PERIOD AND DRY IS EXPECTED...ALTHOUGH LESS
CONFIDENCE DUE TO THE EC ON WED. EXPECTING THE RIDGE IN THE WEST
TO AMPLIFY WITH HIGHS WARMING BACK INTO THE 40S AND EVEN A FEW
50S BY FRIDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 6 AM CST SAT DEC 28 2013
MAIN AVIATION CONCERNS IN THIS FORECAST WILL BE WINDS AND PATCHY
FREEZING DRIZZLE WITH STRONG COLD FRONTAL PASSAGE TODAY. LIGHT AND
VARIABLE WINDS EARLY THIS MORNING WILL BECOME NORTHWEST THROUGH
THE MORNING AND INCREASE THROUGH THE AFTERNOON WITH THE STRONGEST
WINDS DEVELOPING AFTER NOON CST. NORTHWEST WINDS AT 25 TO 35KTS
OVER MOST OF WESTERN NEBRASKA THIS AFTERNOON AND EVENING. PATCHY FREEZING
DRIZZLE IS ALSO POSSIBLE THIS AFTERNOON OVER NORTHERN NEBRASKA BUT
CONFIDENCE IS NOT STRONG ENOUGH TO MAKE THIS PREVAILING AND HAVE
IT IN TEMPO GROUP THROUGH THE LATE AFTERNOON IN KVTN TAF. LIGHT
SNOW SHOWERS OR FLURRIES ARE POSSIBLE THROUGH THE EVENING BUT HAVE
LEFT OUT FOR NOW.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL MIDNIGHT CST /11 PM MST/ TONIGHT FOR NEZ005-
006-008-009-022>026-035>037-056-057-094.
WIND ADVISORY UNTIL 3 AM CST SUNDAY FOR NEZ007-010-027>029-038.
&&
$$
UPDATE...TAYLOR
SHORT TERM...POWER
LONG TERM...MASEK
AVIATION...POWER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1153 AM CST SAT DEC 28 2013
.AVIATION...
18Z TAFS FOR KOMA...KLNK...KOFK.
A STRONG COLD FRONT WILL MOVE INTO THE AREA THIS AFTERNOON WITH
STRONG NORTHWEST TO NORTH WINDS SPREADING ACROSS THE AREA BEHIND
THE FRONT. STRONG WINDS ARE EXPECTED TO CONTINUE THROUGH MOST
OF THE PERIOD WITH VFR CIGS.
&&
.PREV DISCUSSION... /ISSUED 1015 AM CST SAT DEC 28 2013/
UPDATE...
INCREASED MAX TEMPERATURES FOR TODAY BASED ON RAP FORECAST
SOUNDINGS MIXING FROM 950MB.
PREV DISCUSSION... /ISSUED 305 AM CST SAT DEC 28 2013/
DISCUSSION...
POTENTIAL FOR A WIND ADVISORY AND WIND CHILL ADVISORY WILL BE THE
MAIN FORECAST CONCERNS IN THIS PERIOD...BUT WILL ALSO NEED TO LOOK
CLOSELY AT TEMPERATURES AND THE CHANCE FOR LIGHT PCPN.
UPPER AIR CHARTS FROM LAST EVENING SHOWED A MODEST 100+ KNOT JET MAX
AT 300 MB DIVING SOUTHEAST TOWARD THE PACIFIC NORTHWEST. AT 500 MB
HEIGHT FALLS OF UP TO 160 METERS WERE NOTED WITH THE SHORTWAVE
TROUGH EXTENDING FROM BRITISH COLUMBIA AND ALBERTA DOWN INTO
NORTHERN CALIFORNIA. AT 850 MB...VERY MILD AIR...WITH TEMPERATURES
FROM 5-10 DEGREES CELSIUS WAS NOTED ACROSS THE CENTRAL PLAINS. VERY
COLD AIR WAS POISED TO THE NORTH...OVER ALBERTA AND SASKATCHEWAN.
LOW PRESSURE WILL MOVE RAPIDLY EAST/SOUTHEAST ACROSS THE DAKOTAS AND
MINNESOTA TODAY...AND A STRONG COLD FRONT WILL DROP SOUTHWARD ACROSS
THE PLAINS. THIS WILL BRING A WIND SHIFT TO THE LOCAL AREA LATER
THIS AFTERNOON AND EVENING. TEMPERATURES AHEAD OF THE FRONT SHOULD
TOP OUT IN THE 50S AT MANY LOCATIONS. IN OUR FAR NORTHWEST...WHERE
THE COLD AIR WILL MOVE IN EARLIEST...HIGHS MAY BE HELD TO THE 40S.
SOME UPPER 40S ALSO APPEAR POSSIBLE OVER LINGERING SNOW COVER
NEAR THE MISSOURI BORDER.
FOR AT LEAST MOST OF THE DAY...WINDS ARE EXPECTED TO REMAIN BELOW
ADVISORY LEVELS. THE FAR NORTHWEST ZONES MAY GET CLOSE TO 30 MPH
SUSTAINED BY LATE AFTERNOON. THE DAY SHIFT WILL NEED TO MONITOR
THIS. THE COMBINATION OF STRONG WINDS AND COLD TEMPERATURES WILL
CAUSE WIND CHILLS TO DROP TO AROUND 20 BELOW ZERO BY MIDNIGHT AT
LEAST IN OUR NORTHERN ZONES...AND A WIND CHILL ADVISORY MAY BE
NEEDED. WINDS WILL REMAIN FAIRLY STRONG INTO SUNDAY MORNING...AS
A 1040 MB HIGH PRESSURE CENTER CONTINUES TO BUILD SOUTHEAST
ACROSS THE DAKOTAS.
OTHERWISE...MODELS SHOW LOW LEVELS BECOMING SATURATED THIS
EVENING AS THE COLD AIR POURS IN. BUT FOR A WHILE...THERE MAY NOT
BE ANY ICE CRYSTALS ALOFT. THIS SUGGESTS THAT IF LIGHT PCPN
FALLS...IT MAYBE DRIZZLE OR FREEZING DRIZZLE AT LEAST BRIEFLY
UNTIL THE COLD AIR BECOMES DEEP ENOUGH TO CHANGE THE PCPN TO
FLURRIES/LIGHT SNOW. AS THE HIGH PRESSURE RIDGE BUILDS OVER THE
AREA SUNDAY AFTERNOON INTO SUNDAY EVENING...WINDS WILL SLACKEN.
WEAK LOW LEVEL WARM AIR ADVECTION SHOULD START AT LEAST IN OUR
WESTERN ZONES SUNDAY NIGHT...AS LOW PRESSURE MOVES INTO WESTERN
SOUTH DAKOTA AND SOUTHERLY WINDS RETURN. INCREASED HIGHS JUST A
BIT ON MONDAY...WITH LACK OF SNOW ON THE GROUND AND DECENT MIXING
EXPECTED. PCPN WITH THE LOW PRESSURE SYSTEM MOVING THROUGH THE
REGION ON MONDAY SHOULD STAY TO OUR NORTH.
SNOW CHANCES LOOK A LITTLE BETTER ON TUESDAY AND INTO TUESDAY NIGHT
FOR ABOUT THE NORTHERN HALF OF THE FORECAST AREA. THIS WILL BE IN
A TIGHT BAROCLINIC ZONE WITH SOME MID LEVEL FORCING.
DETAILS OF THE FORECAST BECOME LESS CLEAR BY WEDNESDAY AND THURSDAY
SO CONFIDENCE DROPS TO AROUND OR BELOW AVERAGE BY THEN. GENERALLY
USED A MODEL FOR WEDNESDAY THROUGH FRIDAY.
MILLER
AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
VFR CONDITIONS ARE EXPECTED THROUGH SATURDAY EVENING. CLEAR SKIES
AND SOUTH TO SOUTHWEST WINDS WILL PREVAIL OVERNIGHT...WITH
SOUTHWEST WINDS INCREASING TOWARD 15KT BY 18Z. A STRONG COLD FRONT
WILL PLUNGE THROUGH EASTERN NEBRASKA LATE SATURDAY AFTERNOON AND
EVENING ARRIVING AT KOFK BY 21Z THEN KLNK AND KOMA BY 00Z. WINDS
WILL BECOME NORTHWEST THEN NORTH AND INCREASE INTO THE 25 TO 35KT
RANGE BEFORE 06Z. VFR CIGS NEAR FL040 ARE EXPECTED BEHIND THE
FRONT...BUT AREAS OF MVFR CIGS AND FLURRIES COULD ALSO OCCUR.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
FOBERT
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1015 AM CST SAT DEC 28 2013
.UPDATE...
INCREASED MAX TEMPERATURES FOR TODAY BASED ON RAP FORECAST
SOUNDINGS MIXING FROM 950MB.
&&
.PREV DISCUSSION... /ISSUED 614 AM CST SAT DEC 28 2013/
AVIATION...
12Z TAFS FOR KOMA...KLNK...KOFK.
MAIN AVN ISSUES THIS MORNING ARE LOW CIGS/WIND SHIFT ASSOCIATED
WITH ARCTIC FRONT MOVING INTO ERN NEB LATER TODAY. LATEST OBS
INDICATE DEEP SFC LOW WAS CENTERED OVER ERN ND WITH ATTENDANT COLD
FRONT STRADDLING MT/CANADIAN BORDER. A GRADUAL WIND SHIFT TO NW WILL
PROCEDE INCOMING MVFR CIGS AT ALL TERMINALS. EXPECT WIND SHIFT AT
KOFK/KLNK AROUND 00Z...THEN KOMA TWD 02Z THIS EVENING. CIGS
GENERALLY FL025 AGL WITH NW WIND G35-45KT WILL THEN PREVAIL THE
REST OF THE FCST PD AT ALL SITES.
DEE
PREV DISCUSSION... /ISSUED 305 AM CST SAT DEC 28 2013/
DISCUSSION...
POTENTIAL FOR A WIND ADVISORY AND WIND CHILL ADVISORY WILL BE THE
MAIN FORECAST CONCERNS IN THIS PERIOD...BUT WILL ALSO NEED TO LOOK
CLOSELY AT TEMPERATURES AND THE CHANCE FOR LIGHT PCPN.
UPPER AIR CHARTS FROM LAST EVENING SHOWED A MODEST 100+ KNOT JET MAX
AT 300 MB DIVING SOUTHEAST TOWARD THE PACIFIC NORTHWEST. AT 500 MB
.HEIGHT FALLS OF UP TO 160 METERS WERE NOTED WITH THE SHORTWAVE
TROUGH EXTENDING FROM BRITISH COLUMBIA AND ALBERTA DOWN INTO
NORTHERN CALIFORNIA. AT 850 MB...VERY MILD AIR...WITH TEMPERATURES
FROM 5-10 DEGREES CELSIUS WAS NOTED ACROSS THE CENTRAL PLAINS. VERY
COLD AIR WAS POISED TO THE NORTH...OVER ALBERTA AND SASKATCHEWAN.
LOW PRESSURE WILL MOVE RAPIDLY EAST/SOUTHEAST ACROSS THE DAKOTAS AND
MINNESOTA TODAY...AND A STRONG COLD FRONT WILL DROP SOUTHWARD ACROSS
THE PLAINS. THIS WILL BRING A WIND SHIFT TO THE LOCAL AREA LATER
THIS AFTERNOON AND EVENING. TEMPERATURES AHEAD OF THE FRONT SHOULD
TOP OUT IN THE 50S AT MANY LOCATIONS. IN OUR FAR NORTHWEST...WHERE
THE COLD AIR WILL MOVE IN EARLIEST...HIGHS MAY BE HELD TO THE 40S.
SOME UPPER 40S ALSO APPEAR POSSIBLE OVER LINGERING SNOW COVER
NEAR THE MISSOURI BORDER.
FOR AT LEAST MOST OF THE DAY...WINDS ARE EXPECTED TO REMAIN BELOW
ADVISORY LEVELS. THE FAR NORTHWEST ZONES MAY GET CLOSE TO 30 MPH
SUSTAINED BY LATE AFTERNOON. THE DAY SHIFT WILL NEED TO MONITOR
THIS. THE COMBINATION OF STRONG WINDS AND COLD TEMPERATURES WILL
CAUSE WIND CHILLS TO DROP TO AROUND 20 BELOW ZERO BY MIDNIGHT AT
LEAST IN OUR NORTHERN ZONES...AND A WIND CHILL ADVISORY MAY BE
NEEDED. WINDS WILL REMAIN FAIRLY STRONG INTO SUNDAY MORNING...AS
A 1040 MB HIGH PRESSURE CENTER CONTINUES TO BUILD SOUTHEAST
ACROSS THE DAKOTAS.
OTHERWISE...MODELS SHOW LOW LEVELS BECOMING SATURATED THIS
EVENING AS THE COLD AIR POURS IN. BUT FOR A WHILE...THERE MAY NOT
BE ANY ICE CRYSTALS ALOFT. THIS SUGGESTS THAT IF LIGHT PCPN
FALLS...IT MAYBE DRIZZLE OR FREEZING DRIZZLE AT LEAST BRIEFLY
UNTIL THE COLD AIR BECOMES DEEP ENOUGH TO CHANGE THE PCPN TO
FLURRIES/LIGHT SNOW. AS THE HIGH PRESSURE RIDGE BUILDS OVER THE
AREA SUNDAY AFTERNOON INTO SUNDAY EVENING...WINDS WILL SLACKEN.
WEAK LOW LEVEL WARM AIR ADVECTION SHOULD START AT LEAST IN OUR
WESTERN ZONES SUNDAY NIGHT...AS LOW PRESSURE MOVES INTO WESTERN
SOUTH DAKOTA AND SOUTHERLY WINDS RETURN. INCREASED HIGHS JUST A
BIT ON MONDAY...WITH LACK OF SNOW ON THE GROUND AND DECENT MIXING
EXPECTED. PCPN WITH THE LOW PRESSURE SYSTEM MOVING THROUGH THE
REGION ON MONDAY SHOULD STAY TO OUR NORTH.
SNOW CHANCES LOOK A LITTLE BETTER ON TUESDAY AND INTO TUESDAY NIGHT
FOR ABOUT THE NORTHERN HALF OF THE FORECAST AREA. THIS WILL BE IN
A TIGHT BAROCLINIC ZONE WITH SOME MID LEVEL FORCING.
DETAILS OF THE FORECAST BECOME LESS CLEAR BY WEDNESDAY AND THURSDAY
SO CONFIDENCE DROPS TO AROUND OR BELOW AVERAGE BY THEN. GENERALLY
USED A MODEL FOR WEDNESDAY THROUGH FRIDAY.
MILLER
AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
VFR CONDITIONS ARE EXPECTED THROUGH SATURDAY EVENING. CLEAR SKIES
AND SOUTH TO SOUTHWEST WINDS WILL PREVAIL OVERNIGHT...WITH
SOUTHWEST WINDS INCREASING TOWARD 15KT BY 18Z. A STRONG COLD FRONT
WILL PLUNGE THROUGH EASTERN NEBRASKA LATE SATURDAY AFTERNOON AND
EVENING ARRIVING AT KOFK BY 21Z THEN KLNK AND KOMA BY 00Z. WINDS
WILL BECOME NORTHWEST THEN NORTH AND INCREASE INTO THE 25 TO 35KT
RANGE BEFORE 06Z. VFR CIGS NEAR FL040 ARE EXPECTED BEHIND THE
FRONT...BUT AREAS OF MVFR CIGS AND FLURRIES COULD ALSO OCCUR.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
FOBERT
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
938 PM EST SUN DEC 29 2013
.SYNOPSIS...
SURFACE LOW PRESSURE WILL MOVE INTO NEW ENGLAND TONIGHT AND INTO
EASTERN CANADA BY MONDAY...WHILE A SHARP ARCTIC COLD FRONT PUSHES
ACROSS THE NORTH COUNTRY ON MONDAY MORNING. A MIX OF RAIN AND SNOW
WILL GRADUALLY END TONIGHT WITH SOME MODERATE SNOW ACCUMULATION
LIKELY ACROSS THE HIGHER TERRAIN OF CENTRAL AND SOUTHERN VERMONT.
ADDITIONAL SNOW SHOWERS WILL BE POSSIBLE ASSOCIATED WITH THE
ARCTIC BOUNDARY ON MONDAY MORNING...WITH A FLASH FREEZE
LIKELY...CREATING A HAZARDOUS COMMUTE.
&&
.NEAR TERM /UNTIL 10 AM MONDAY MORNING/...
AS OF 922 PM EST SUNDAY...QUICK HITTING WINTER STORM NOW WINDING
DOWN ACROSS THE REGION AS STRENGTHENING LOW PRESSURE CENTERED
NEAR NANTUCKET MOVES NORTHEASTWARD OVER CAPE COD AND TO A POSITION
OVER NOVA SCOTIA BY MONDAY MORNING. HEAVIEST PRECIPITATION NOW
OVER SOUTHEASTERN VERMONT WITH LIGHT-MODERATE PRECIP STILL BACK
INTO THE CHAMPLAIN VALLEY. BACK EDGE HAS CLEARED PLATTSBURGH AND
WILL PUSH THROUGH BURLINGTON WITHIN THE HOUR. PRECIP WILL TAPER
OFF FAIRLY QUICKLY OVER THE NEXT 2-3 HOURS FOR ENTIRE REGION. MOST
PRECIP HAS FALLEN AS SNOW WHERE IT HAS BEEN HEAVY DUE TO DYNAMIC
COOLING...AT RATES OF 1-3 INCHES PER HOUR IN SE VT. REPORTS ACROSS
SOUTHERN AND EASTERN VERMONT GENERALLY RANGE BETWEEN 3 AND 9
INCHES SO FAR. HOWEVER...WHERE IT HAS REMAINED LIGHTER ALLOWING
THE WARM BOUNDARY LAYER TO HANG ON...IT HAS BEEN IN THE FORM OF A
RAIN/SNOW MIX. LOW LEVEL COLD AIR HAD ALSO SUNK SOUTHWARD INTO THE
CHAMPLAIN VALLEY...DELIVERING LIGHT FREEZING RAIN/SLEET (FROM BTV
NORTHWARD) WITH WARM LAYER STILL REMAINING AT AROUND 925-MB. LOCAL
BTV WRF AND HRRR MODELS HANDLING THERMAL PROFILES AND DEPICTION OF
PRECIPITATION THE BEST SO HAVE LEANED HEAVILY TOWARDS THEM FOR THE
REST OF TONIGHT.
ARCTIC FRONT THEN BRINGS AN ADDITIONAL CHANCE OF SNOW SHOWERS
TOWARDS MORNING...WITH RAPIDLY FALLING TEMPERATURES AND THREAT OF
FREEZING WATER/SLUSH ON ROADWAYS.
TOTALS GENERALLY 4-8" LOCALLY 10" IN ORANGE/WINDSOR/EASTERN RUTLAND
COUNTIES...DUSTING-4" HIGHLY DEPENDENT ON PRECIP INTENSITY AND
ELEVATION ACROSS MUCH OF THE REST OF VERMONT OUTSIDE OF THE
CHAMPLAIN VALLEY...AND A DUSTING-2" ELSEWHERE. ICE ACCUMULATIONS
IN THE CPV GENERALLY A FEW HUNDRETHS...ENOUGH TO CAUSE HAZARDOUS
TRAVEL AND ACCIDENTS.
&&
.SHORT TERM /10 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 322 PM EST SUNDAY...WITH UPSLOPE SNOW SHOWERS ACROSS THE
HIGHER TERRAIN EFFECTIVELY COMING TO AN END EARLY MONDAY
NIGHT...THE FOCUS THEN SHIFTS TO A PERIOD OF VERY COLD
TEMPERATURES BEGINNING MONDAY NIGHT AND CONTINUING INTO THE FIRST
FEW DAYS OF 2014.
ARCTIC COLD FRONT MOVES ACROSS THE REST OF THE NORTH COUNTRY EARLY
MONDAY NIGHT ALLOWING FOR 850 TEMPS TO FALL TO AROUND -16 TO -18C.
WITH DEEP-LAYER DRYING TAKING PLACE AS HIGH PRESSURE BUILDS INTO THE
REGION OVERNIGHT TEMPERATURES MONDAY WILL BE QUITE COLD. ASIDE FROM
SOUTHERN VERMONT...MOST LOCATIONS WILL SEE LOWS THAT ARE BELOW ZERO
EVEN IN THE CHAMPLAIN VALLEY. I THINK THE COLDEST SPOT MONDAY NIGHT
WILL BE IN THE NORTHEAST KINGDOM AS THAT AREA IS FURTHEST REMOVED
FROM MID-LEVEL WARM ADVECTION CLOUDINESS WHICH IS PROJECTED TO SPILL
INTO NORTHERN NEW YORK LATE MONDAY NIGHT.
INCREASING CLOUDS THEN SPREAD ACROSS THE REST OF THE NORTH COUNTRY
TUESDAY AHEAD OF A MOISTURE-STARVED CLIPPER SYSTEM. DESPITE THE
FACT THAT MOISTURE WILL BE LIMITED WITH THE CLIPPER...ACCOMPANYING
ISENTROPIC LIFT AND RATHER HIGH SNOW/LIQUID RATIOS (15-20:1) DUE TO
COLD AIRMASS IN PLACE SHOULD ALLOW FOR AT LEAST A MODEST POWDERY
SNOW ACCUMULATION OF 1-3". THE ASSOCIATED COLD FRONT WILL THEN
USHER IN ANOTHER SHOT OF EVEN COLDER AIR TUESDAY NIGHT. NORTHWEST
WINDS WILL ALSO BE IN THE 15 TO 20 MPH RANGE WITH GUSTS TO 30 MPH
AS WELL FROM STRONGER MIXING. IT WOULDN`T BE SURPRISING IF SOME
LOCALES IN THE NORTHEAST KINGDOM AND NORTHERN NEW YORK HIT WIND
CHILL ADVISORY CRITERIA...WHICH WILL NEED TO BE MONITORED WITH LATER
SHIFTS. LOWS TUESDAY NIGHT MAY BE A FEW DEGREES WARMER THAN MONDAY
NIGHT (RANGING FROM THE LOWER SINGLE DIGITS TO 10 BELOW ZERO)...BUT
IT CERTAINLY WON`T FEEL THAT WAY GIVEN THE WINDS.
A RIDGE OF ARCTIC HIGH PRESSURE WILL EXTEND ACROSS THE NORTHERN
HALF OF THE NORTH COUNTRY ON WEDNESDAY...SEPERATING A DEVELOPING
EAST-WEST WARM FRONTAL BOUNDARY EXTENDING FROM A DISTURBANCE IN THE
GREAT LAKES. THE NORTH COUNTRY REMAINS ON THE COLD SIDE OF THIS
BOUNDARY THROUGHOUT WEDNESDAY...AND HAVE SHOWN INCREASING POPS FROM
SOUTH TO NORTH WEDNESDAY INTO WEDNESDAY NIGHT. I DO THINK THAT
THERE WILL PROBABLY BE A SHARP NORTH-SOUTH GRADIENT IN
PRECIPITATION GIVEN THE INFLUENCE OF THE ARCTIC HIGH WITH THE
HIGHEST POPS (CHANCE) CONFINED TO CENTRAL AND SOUTHERN VERMONT.
TEMPERATURES REMAIN COLD WITH HIGHS IN THE SINGLE DIGITS TO LOW
TEENS AND LOWS 0 TO 15 BELOW (COLDEST NORTH).
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 322 PM EST SUNDAY...CONSISTENCY IS GOOD AMONGST GLOBAL
MODELS INTO THURSDAY WITH SOME DIFFERENCES IN POSITION AND TRACK
OF A POTENTIAL COASTAL SYSTEM APPROACHING SOUTHERN NEW ENGLAND AND
ADJACENT COASTAL WATERS. THEME OF COLD TEMPERATURES CONTINUES
EARLY IN THIS PERIOD WITH AN INCREASING TREND TOWARD MORE ACTIVE
WEATHER FOR LATE IN THE WEEK.
LIGHT SNOWS SHOULD BE ONGOING TO OPEN THE EXTENDED WITH THE NORTH
COUNTRY ON THE NORTHERN SIDE OF A QUASI-STATIONARY BOUNDARY OVER
CENTRAL/SOUTHERN NEW ENGLAND. MEANWHILE...A MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE LOWER OHIO VALLEY WILL HELP TO ENERGIZE A
DEVELOPING COASTAL LOW NEAR THE CHESAPEAKE BAY AREA EARLY THURSDAY
MORNING. THE GFS TAKES THE DEVELOPING COASTAL NEAR OR JUST
SOUTHEAST OF THE 40N/70W BENCHMARK...WHILE THE ECMWF IS STRONGER
AND DECIDEDLY MORE INSIDE THE BENCHMARK. THOUGH BOTH MODELS SHOW A
DIFFERING CENTER TRACK...THE SOLUTIONS ARE AT LEAST CONSISTENT WITH
THEIR PRIOR COUPLE OF RUNS. BOTH GFS AND ECMWF SHOW A GOOD EASTERN
UPSLOPE PRECIPITATION ENHANCEMENT SIGNATURE AND HAVE SHOWN THE
HIGHEST POPS (LOW LIKELY) TOWARD THE EAST-FACING SLOPE AREAS FOR
THURSDAY NIGHT. LINGERING SNOWS CONTINUE INTO EARLY FRIDAY BEFORE
TAPERING THEREAFTER. IT`S STILL A LITTLE EARLY TO PROJECT SNOW
AMOUNTS WITH MORE SPECIFIC DETAILS WHICH STILL BE IRONED OUT...BUT
IT`S PROBABLY FAIR TO SAY THAT THERE WOULD BE SOME POTENTIAL IMPACT
FROM THIS COASTAL FOR THE NORTH COUNTRY. HIGHS THURSDAY AND FRIDAY
WILL STAY IN THE SINGLE DIGITS.
A LARGE-AMPLITUDE UPPER-LEVEL TROUGH THEN LINGERS OVER THE NORTH
COUNTRY FRIDAY NIGHT INTO SATURDAY WHICH WILL MAINTAIN CONTINUED
BITTER COLD. 850 TEMPS OF -24 TO -26C ALONG WITH AT LEAST PARTLY
CLOUDY SKIES SHOULD RESULT IN LOWS FRIDAY NIGHT AROUND -8 TO -16
BELOW. SOME INDICATION BY LATER IN THE WEEKEND THAT THE VERY COLD
TEMPERATURES FINALLY BEGIN TO MODERATE.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
THROUGH 18Z MONDAY...IFR/MVFR AS LOW PRESSURE TRACKS ACROSS
SOUTHEAST NEW ENGLAND BY MIDNIGHT AND WITH ARCTIC FRONT DRAPED
KMSS-KBTV.
PRECIPITATION TYPE IS TRICKY AS CURRENT TEMPS RANGING FROM 25 AT
KMSS TO ABOUT FREEZING OTHER SITES. MIXED PRECIP AT KBTV/KPBG/KSLK
AND SNOW AT KRUT/KMPV AND COMING DOWN MODERATLY. THIS WILL BE A QUICK
HITTER AS PRECIP TAPERS OFF BY AROUND MIDNIGHT LEAVING SOME
RESIDUAL -DZ -FZDZ DEPENDING UPON TEMPS WHICH WILL BE EITHER SIDE
OF 32.
EARLY TOMORROW MORNING, BASICALLY 06Z KMSS TO 09Z KBTV TO 11Z
KRUT/MPV, ARCTIC FRONTAL PASSAGE EXPECTED WITH SCATTERED BRIEF
HEAVIER SNOW SHOWER OR TWO, MOST PERSISTENT IN THE HIGHER
ELEVATIONS. TEMPS WILL FALL 20 DEGREES IN A COUPLE HOURS AND WINDS
WILL GUST AS HIGH AS 25 KTS PERHAPS 30KT SO WILL BE A QUICK ICE UP
OF RUNWAYS AND SOME DRIFTING.
EXPECTING IMPROVING CONDITIONS 15-21Z AS DRIER AIR MOVES IN AND
WINDS SETTLE DOWN SOMEWHAT.
OUTLOOK 00Z TUESDAY THROUGH FRIDAY...
MON NIGHT...VFR WITH LIGHT WINDSWITH ARCTIC AIR.
TUE...BECMG IFR IN PM LIGHT SNOW WITH LOW PRESSURE CLIPPER
SYSTEM.
WED...MAINLY VFR UNDER ARCTIC HIGH PRESSURE.
THU-FRI...BECMG IFR IN SNOW WITH LOW PRESSURE OFF THE COAST.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR VTZ010-012-018-
019.
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR VTZ003-004-
006>008-011-017.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...MUCCILLI
SHORT TERM...LOCONTO
LONG TERM...LOCONTO
AVIATION...SISSON
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
649 PM EST SUN DEC 29 2013
.SYNOPSIS...
SNOW AND MIXED RAIN AND SNOW WILL TAPER OFF THIS EVENING...WITH
LAKE EFFECT SNOW SHOWERS DEVELOPING SOUTHEAST OF LAKE ONTARIO
OVERNIGHT. MUCH COLDER WEATHER IS EXPECTED ON MONDAY FOR MOST OF
THE REGION AS THE LAKE EFFECT SNOW SHOWERS DIMINISH. A SERIES OF
CLIPPERS WILL BRING PERIODS OF LIGHT SNOW TO THE REGION THROUGH
WEDNESDAY WITH A CONTINUATION OF COLD TEMPERATURES. A LARGER
STORM SYSTEM COULD AFFECT THE REGION THURSDAY WITH MORE SNOW
POSSIBLE.
&&
.NEAR TERM /THROUGH MONDAY/...
600 PM UPDATE...QUICK GRID UPDATE TO REFLECT RAPIDLY EVOLVING
CHANGE OVER FROM RAIN TO SNOW AND ALSO RAPIDLY DEPARTING SHIELD OF
PRECIPITATION WITH DEVELOPING COASTAL LOW OFF THE TIP OF LONG
ISLAND. HRRR SEEMS TO CAPTURE THE EVOLUTION OF THE PRECIP SHIELD
BEST ON ITS SIMULATED REFLECTIVITY AND HAS IT DEPARTING C NY AND
NE PA BTWN 00Z AND 01Z WITH LINGERING LIGHTER RETURNS FOR A COUPLE
HOURS AFTER. ISSUED A COUPLE SPS/S TO COVER INTENSE SNOWFALL RATES
AS STRG UVV TURNED OVER THE RAIN TO SNOW IN A HURRY. MANY REPORTS
OF ACCIDENTS AS SNOW RATES TOPPED 1 INCH PER HOUR. DIMINISH
HEAVIER SNOWS TO SNOW SHOWERS/FLURRIES PRETTY QUICKLY THIS
EVENING BTWN 23Z AND 01Z. WINTER WX ADVY REMAINS IN EFFECT
DELAWARE/OTSEGO CO/S AS HEAVIEST SNOW HAS SHIFTED INTO THESE AREAS NOW.
WUDN`T BE SURPRISED IF IT IS ALL OVER THERE BEFORE 9 PM AS WELL SO
MAY HAVE TO DROP ADVY EARLY. DECISION WILL BE MADE WITH NEXT
UPDATE. SNOW ACC/S MOST AREAS WERE 1-3 INCHES...HIGHER TERRAIN OF
DELAWARE/OTSEGO LIKELY WILL SEE 4-6 INCHES AS IT HAS BEEN SNOWING
THERE LONGER AND MORE IS COMING.
PREVIOUS DSCN IS BELOW...
RAIN AND HIGHER ELEVATION SNOW ACRS THE FCST AREA ATTM. WE SHUD
SEE A GRADUAL TRANSITION TO MORE IN THE WAY OF SNOW LATE THIS AFTN
AND EVNG. MAINLY SNOW OVER THE HIGHER ELEVATIONS WHEN PCPN
INTENSITY INCREASES. WE`VE GONE BACK AND FORTH HERE AT BGM WITH
RAIN/SNOW. WILL KEEP THE ADVISORY FOR ERN CATSKILLS...AND CONTINUE
WITH POTNL FOR AN INCH OR TWO ACRS THE HIGHER ELEVATIONS OF CNTRL
NY AND NRN PA. PCPN XPCTD TO TAPER OFF THIS EVNG AS MAIN S/WV
TRACKS EWD. SOME LES XPCTD TO DVLP LATER TNGT AFTER 06Z AND DROP
SWD INTO THE SYR AREA BY MORNING. LES PARAMS AND MESO MDLS NOT
OVERLY IMPRSV WTIH THIS EVENT...AND HAVE ONLY POTNL FOR AN INCH OR
TWO OF ACCUM BEFORE ACITIVTY DIMINISHES ON MON AFTN. OTRW GNRLY
FAIR AND QUITE BLUSTERY WITH TEMPS STEADY OF SLOWLY FALLING INTO
THE TEENS MANY AREAS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
QUIET WX ON MON NGT IN ADVANCE OF THE NXT S/WV WHICH WILL PASS ON
TUE. ANOTHER ONE ARRIVES FOR WED...WHICH SHUD RESULT IN A MORE
WDSPRD SNOW EVENT. IN BETWEEN SYSTEMS...BRIEF PD OF LES IS LIKELY
ACRS THE NORTH COUNTRY ON TUE NGT. BLUSTERY CONDITIONS ONCE AGAIN
AFTER PSSG OF TUE`S WAVE. GIVEN TDA`S ACTIVE SCENARIO...WE`LL
FOCUS IN ON THESE SYSTEMS WITH LATER FCST UPDATES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
XTNDD PD ALL ABT THE PTNL SNOW STORM FOR THU. FOR ONCE...IT
DOESN/T APPEAR AS THOUGH PTYPE WILL BE IN QUESTION. THAT DOESN/T
MEAN THAT THERE ARE NO QUESTIONS ABT THE SYSTEM THOUGH. BIGGEST
DFRNC BETWEEN THE EURO AND GFS IS IN THE MOISTURE SOURCE AS THE
EURO SHAPENS THE UPR WV AND CLOSES THE SFC LOW SOONER THUS
ALLOWING THE SYSTEM TO TAP GULF MOISTURE BEFORE MVG EAST OF THE
FCST AREA. GFS HAS MORE OF AN OPEN WV THAT DOESN/T TAP ATLANTIC
MOISTURE UNTIL IT IS EAST OF THE FCST AREA. IN ANY EVENT...LOOKS
LIKE A GOOD BET FOR SNOW ON THU TRANSITIONING TO A LE EVENT FRI AS
THE UPR TROF DEEPENS. HIPRES BLDS IN AND QUIET WX WITH SLOW WRMG
CONTS THRU THE END OF THE PD.
OTR QUESTION IS THE TIMING AND AMT OF COLD AIR THAT LEAKS DOWN
WITH THE SYSTEM. BOTH MODELS SHOW A BREIF PD OF FRIGID AIR BHD THE
LOW LATE FRI INTO SAT WITH TEMPS BLOW NRML AGAIN BEFORE WRMG
BEGINS LATE SAT/SUN.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
IFR CIGS AND VSBYS IN MIXED PRECIPITATION THROUGH THE AREAS OF
TERRAIN IN THE PA/NY TWIN TIER. SOME VALLEY LOCATIONS MVFR CIGS.
ACROSS THE FINGER LAKES INTO THE MOHAWK VALLEY VFR WITH SOME AREAS
OF MVFR RAIN AND FOG. PRECIPITATION IS PULLING OUT TO THE EAST
OVER THE NEXT FEW HOURS. COOLER AIR WILL WORK IN WITH LINGERING MVFR STRATUS
AND POSSIBLE LIGHT SNOWSHOWERS. AFTER 09Z CLOUD BASES SHOULD BEGIN
TO RISE AND DEVELOP SOME BREAKS...BECOMING VFR AFTER DAYBREAK.
LIGHT WINDS INCREASING AFTER 09Z TO NW 15 KT GUST TO 25 KT.
OUTLOOK...
MON NGT...MAINLY VFR.
TUE...SCT MVFR IN -SHSN ACRS CNTRL NY.
TUE NGT/WED...IFR/MVFR IN -SHSN.
THU...IFR SNOW.
FRI...VFR/MVFR IN SNOW SHWRS
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ046-057.
&&
$$
SYNOPSIS...
NEAR TERM...DJN
SHORT TERM...
LONG TERM...DGM
AVIATION...BMW
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
611 PM EST SUN DEC 29 2013
.SYNOPSIS...
SNOW AND MIXED RAIN AND SNOW WILL TAPER OFF THIS EVENING...WITH
LAKE EFFECT SNOW SHOWERS DEVELOPING SOUTHEAST OF LAKE ONTARIO
OVERNIGHT. MUCH COLDER WEATHER IS EXPECTED ON MONDAY FOR MOST OF
THE REGION AS THE LAKE EFFECT SNOW SHOWERS DIMINISH. A SERIES OF
CLIPPERS WILL BRING PERIODS OF LIGHT SNOW TO THE REGION THROUGH
WEDNESDAY WITH A CONTINUATION OF COLD TEMPERATURES. A LARGER
STORM SYSTEM COULD AFFECT THE REGION THURSDAY WITH MORE SNOW
POSSIBLE.
&&
.NEAR TERM /THROUGH MONDAY/...
600 PM UPDATE...QUICK GRID UPDATE TO REFLECT RAPIDLY EVOLVING
CHANGE OVER FROM RAIN TO SNOW AND ALSO RAPIDLY DEPARTING SHIELD OF
PRECIPITATION WITH DEVELOPING COASTAL LOW OFF THE TIP OF LONG
ISLAND. HRRR SEEMS TO CAPTURE THE EVOLUTION OF THE PRECIP SHIELD
BEST ON ITS SIMULATED REFLECTIVITY AND HAS IT DEPARTING C NY AND
NE PA BTWN 00Z AND 01Z WITH LINGERING LIGHTER RETURNS FOR A COUPLE
HOURS AFTER. ISSUED A COUPLE SPS/S TO COVER INTENSE SNOWFALL RATES
AS STRG UVV TURNED OVER THE RAIN TO SNOW IN A HURRY. MANY REPORTS
OF ACCIDENTS AS SNOW RATES TOPPED 1 INCH PER HOUR. DIMINISH
HEAVIER SNOWS TO SNOW SHOWERS/FLURRIES PRETTY QUICKLY THIS
EVENING BTWN 23Z AND 01Z. WINTER WX ADVY REMAINS IN EFFECT
DELAWARE/OTSEGO CO/S AS HEAVIEST SNOW HAS SHIFTED INTO THESE AREAS NOW.
WUDN`T BE SURPRISED IF IT IS ALL OVER THERE BEFORE 9 PM AS WELL SO
MAY HAVE TO DROP ADVY EARLY. DECISION WILL BE MADE WITH NEXT
UPDATE. SNOW ACC/S MOST AREAS WERE 1-3 INCHES...HIGHER TERRAIN OF
DELAWARE/OTSEGO LIKELY WILL SEE 4-6 INCHES AS IT HAS BEEN SNOWING
THERE LONGER AND MORE IS COMING.
PREVIOUS DSCN IS BELOW...
RAIN AND HIGHER ELEVATION SNOW ACRS THE FCST AREA ATTM. WE SHUD
SEE A GRADUAL TRANSITION TO MORE IN THE WAY OF SNOW LATE THIS AFTN
AND EVNG. MAINLY SNOW OVER THE HIGHER ELEVATIONS WHEN PCPN
INTENSITY INCREASES. WE`VE GONE BACK AND FORTH HERE AT BGM WITH
RAIN/SNOW. WILL KEEP THE ADVISORY FOR ERN CATSKILLS...AND CONTINUE
WITH POTNL FOR AN INCH OR TWO ACRS THE HIGHER ELEVATIONS OF CNTRL
NY AND NRN PA. PCPN XPCTD TO TAPER OFF THIS EVNG AS MAIN S/WV
TRACKS EWD. SOME LES XPCTD TO DVLP LATER TNGT AFTER 06Z AND DROP
SWD INTO THE SYR AREA BY MORNING. LES PARAMS AND MESO MDLS NOT
OVERLY IMPRSV WTIH THIS EVENT...AND HAVE ONLY POTNL FOR AN INCH OR
TWO OF ACCUM BEFORE ACITIVTY DIMINISHES ON MON AFTN. OTRW GNRLY
FAIR AND QUITE BLUSTERY WITH TEMPS STEADY OF SLOWLY FALLING INTO
THE TEENS MANY AREAS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
QUIET WX ON MON NGT IN ADVANCE OF THE NXT S/WV WHICH WILL PASS ON
TUE. ANOTHER ONE ARRIVES FOR WED...WHICH SHUD RESULT IN A MORE
WDSPRD SNOW EVENT. IN BETWEEN SYSTEMS...BRIEF PD OF LES IS LIKELY
ACRS THE NORTH COUNTRY ON TUE NGT. BLUSTERY CONDITIONS ONCE AGAIN
AFTER PSSG OF TUE`S WAVE. GIVEN TDA`S ACTIVE SCENARIO...WE`LL
FOCUS IN ON THESE SYSTEMS WITH LATER FCST UPDATES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
XTNDD PD ALL ABT THE PTNL SNOW STORM FOR THU. FOR ONCE...IT
DOESN/T APPEAR AS THOUGH PTYPE WILL BE IN QUESTION. THAT DOESN/T
MEAN THAT THERE ARE NO QUESTIONS ABT THE SYSTEM THOUGH. BIGGEST
DFRNC BETWEEN THE EURO AND GFS IS IN THE MOISTURE SOURCE AS THE
EURO SHAPENS THE UPR WV AND CLOSES THE SFC LOW SOONER THUS
ALLOWING THE SYSTEM TO TAP GULF MOISTURE BEFORE MVG EAST OF THE
FCST AREA. GFS HAS MORE OF AN OPEN WV THAT DOESN/T TAP ATLANTIC
MOISTURE UNTIL IT IS EAST OF THE FCST AREA. IN ANY EVENT...LOOKS
LIKE A GOOD BET FOR SNOW ON THU TRANSITIONING TO A LE EVENT FRI AS
THE UPR TROF DEEPENS. HIPRES BLDS IN AND QUIET WX WITH SLOW WRMG
CONTS THRU THE END OF THE PD.
OTR QUESTION IS THE TIMING AND AMT OF COLD AIR THAT LEAKS DOWN
WITH THE SYSTEM. BOTH MODELS SHOW A BREIF PD OF FRIGID AIR BHD THE
LOW LATE FRI INTO SAT WITH TEMPS BLOW NRML AGAIN BEFORE WRMG
BEGINS LATE SAT/SUN.
&&
.AVIATION /23Z SUNDAY THROUGH FRIDAY/...
CSTL LOW PUSHING MIXED PCPN INTO THE AREA THIS AFTN WITH MVFR CIGS
AND ONCL IFR VSBYS. AS COOLER AIR SLOWLY GETS INVOLVED IN THE
SYSTEM...MORE SNOW AND LWR VSBYS/CIGS WILL BECOME MORE LIKELY
BEFORE THE SYSTEM PULLS OUT BETWEEN 00Z AND 03Z. BHD...JUST SOME
SNOW SHWRS WITH MVFR CIGS AND VSBYS THRU THE NGT. WINDS WILL PICK
UP AS THE STORM DEEPENS TO THE EAST. XPCT GISTY NW WINDS LTR TNGT
INTO MON. VERY DRY AIR AND SHEARED FLOW WILL LIMT LE SNOWS MON BHD
THE LOW.
OUTLOOK...
MON NGT...MAINLY VFR.
TUE...SCT MVFR IN -SHSN ACRS CNTRL NY.
TUE NGT/WED...IFR/MVFR IN -SHSN.
THU...IFR SNOW DEVELOPING.
FRI...VFR/MVFR IN SNOW SHWRS
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ046-057.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...CMG/DGM
LONG TERM...DGM
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1020 PM EST SUN DEC 29 2013
.SYNOPSIS...A WEAK SURFACE TROUGH WILL LINGER OVER THE CAROLINAS
OVERNIGHT. A SECONDARY COLD FRONT WILL CROSS OUR REGION MONDAY
NIGHT...FOLLOWED BY HIGH PRESSURE WHICH WILL PERSIST OVERHEAD
THROUGH THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1020 PM SUNDAY...
MAIN FORECAST CHALLENGE REVOLVES AROUND THE COVERAGE/INTENSITY OF
FOG OVERNIGHT.
SKIES CLEARED OFF NICELY LATE THIS AFTERNOON ACROSS CENTRAL NC WITH
JUST A LINGERING PATCH OF STRATUS NOTED OVER THE FAR SOUTHERN
COUNTIES AT SUNSET. THIS AREA OF CLOUDINESS HAS SINCE DISSIPATED.
MUCH OF THE AREA RECEIVED BETWEEN ONE AND TWO INCHES OF RAIN THE
PAST 24 HOURS. THIS HAS ADEQUATELY SOAKED THE TOP SOIL. IF SKIES
REMAIN MOSTLY CLEAR AND WINDS NEAR CALM....COULD SEE WIDESPREAD FOG
ACROSS THE REGION WITH AREAS OF DENSE FOG POSSIBLE. HOWEVER...A DECK
OF MID-HIGH LEVEL CLOUDS WAS ADVANCING EASTWARD ACROSS THE REGION
AND THIS TREND IS EXPECTED TO OCCUR OVERNIGHT. IN ADDITION...NEAR
SFC FLOW EXPECTED TO BECOME W-NW ACROSS THE NW PIEDMONT AS A WEAK
SFC TROUGH EDGES SLOWLY EAST. THUS...WHILE FOG WILL STILL BE HIGHLY
PROBABLE ACROSS THE SOUTHERN AND EASTERN COUNTIES...EXPECT FOG TO BE
LESS PROMINENT TO THE NW OF RDU. ACROSS THE SOUTH AND EAST...COULD
SEE POCKETS OF DENSE FOG BY EARLY MONDAY MORNING BUT NOT EXPECTING
WIDESPREAD DENSE FOG AT THIS TIME SO WILL HOLD OFF ON AN ADVISORY.
MIN TEMPS BY MORNING SHOULD BE RANGE FROM THE MID-UPPER 30S TO
AROUND 40. &&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 255 PM SUNDAY...
DRY COLD FRONT WILL MOVE THROUGH THE AREA AND PUSH OFF THE CAROLINA
COAST MONDAY. BRIEF LIGHT RAIN WILL DEVELOP EARLY TUESDAY... BETWEEN
06 AND 12Z... AS A WEAK TROUGH DEVELOPS ACROSS THE REGION IN
RESPONSE TO A SHORTWAVE CROSSING THE SOUTHEAST. HIGH PRESSURE WILL
BUILD IN THROUGH THE DAY TUESDAY AND REMAIN OVER THE AREA WEDNESDAY.
SEASONABLE HIGHS NEAR 50... LOWS UPPER 20S TO MID 30S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 256 PM SUNDAY...
MODELS ARE IN GOOD GENERAL AGREEMENT ON A WAVE DIGGING IN TO THE
OHIO VALLEY THURSDAY... AND THE SURFACE LOW DEVELOPS AND MOVES
ACROSS THE MIDATLANTIC/SOUTHERN NEW ENGLAND. HOWEVER... SIGNIFICANT
DIFFERENCES STILL EXIST WITH THE DEVELOPMENT AND TRACK OF A
POTENTIAL COASTAL LOW PRESSURE SYSTEM. ECMWF... AND A FEW GFS
ENSEMBLE MEMBERS... DEVELOP A LOW ALONG THE SOUTHEAST COAST... WHICH
WOULD LEAD TO GREATER PRECIPITATION FOR THIS AREA. GFS... AND MANY OF
ITS ENSEMBLE MEMBERS... ARE DRIER... WITH WEAKER OR FARTHER EASTWARD
COASTAL DEVELOPMENT. WILL CONTINUE TO CARRY SLGT CHC POPS UNTIL
BETTER RESOLUTION IS REACHED.
GOOD AGREEMENT THAT COLD ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND
THE DEPARTING SYSTEM... AND REMAIN ACROSS THE AREA IN TO SUNDAY.
COLD HIGHS FRIDAY IN THE UPPER 30S... FOLLOWED BY COLD LOWS SATURDAY
MORNING... CURRENTLY ADVERTISING LOW 20S... BUT TEENS WOULD
CERTAINLY BE POSSIBLE UNDER GOOD RADIATIONAL COOLING CONDITIONS.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 730 PM SUNDAY...
VFR CONDITIONS ARE GENERALLY EXPECTED THIS EVENING. HOWEVER... A
LINGERING PATCH OF CIGS AROUND 1000-1500 FT IS SLOWLY DISSIPATING
BUT MEANDERING TOWARDS KFAY THIS EVENING. THUS... HAVE INCLUDED A
TEMPO GROUP THROUGH 02Z THIS EVENING FOR THIS LOW END MVFR CIG
THREAT. OTHERWISE... EXPECT VFR CONDITIONS WILL CONTINUE INTO THE
EARLY MORNING HOURS OF MONDAY. THE COMBINATION OF MOIST GROUNDS FROM
RECENT RAINFALL AND LIGHT AND VARIABLE WINDS OVERNIGHT MAY LEAD TO
THE FORMATION OF SOME FOG/VERY LOW STRATUS GENERALLY DURING THE PRE-
DAWN HOURS OF MONDAY MORNING. KGSO AND KINT SEEM TO HAVE THE LEAST
THREAT OF SUB-VFR CONDITIONS AND WILL ACCORDINGLY LEAVE OUT MENTION
OF SUB-VFR CONDITIONS THERE. AT KRWI AND KRDU... WILL GO WITH A
TEMPO FOR MVFR VISBYS... LOW CONFIDENCE THOUGH. THE LATEST HRRR IS
STILL SHOWING THE POTENTIAL FOR SOME IFR/LIFR FOG ACROSS SOUTHERN
PORTIONS OF CENTRAL NC... NEAR KFAY. THIS MAKES SENSE AS THIS IS
WHERE THE LINGERING LOW STRATUS IS CURRENTLY NEAR... ALONG WITH THE
EXPECTED WEAKEST PRESSURE GRADIENT BY MORNING. THUS... WILL GO WITH
A TEMPO FOR LIFR CONDITIONS THERE OVERNIGHT... ALTHOUGH CONFIDENCE
IS ONLY LOW TO MEDIUM AT BEST. EXPECT ANY SUB-VFR CONDITIONS WILL
LIFT TO VFR BY AT LEAST 12-14Z MONDAY. AN APPROACHING POTENT
DISTURBANCE ALOFT WILL ALLOW FOR SOME LOW END VFR CIGS TO RETURN BY
LATE IN THE DAY... WITH MAYBE SOME VERY LIGHT PRECIP AND SUB-VFR
CONDITIONS JUST BEYOND THE 00Z TAF PERIOD.
OUTLOOK: THE PASSAGE OF A SECONDARY COLD FRONT AND UPPER LEVEL
DISTURBANCE MAY RESULT IN A PERIOD OF SUB-VFR CONDITIONS AND A
LITTLE LIGHT RAIN MON NIGHT...AND THEN AGAIN WITH ANOTHER PASSING
STORM SYSTEM LATE IN THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...SEC
LONG TERM...SEC
AVIATION...BSD/MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
759 PM EST SUN DEC 29 2013
.SYNOPSIS...AN AREA OF LOW PRESSURE WILL MOVE QUICKLY NORTHEASTWARD
ALONG THE MIDDLE ATLANTIC COAST THIS EVENING. A SECONDARY COLD FRONT
WILL FOLLOW AND CROSS OUR REGION MON NIGHT...FOLLOWED BY HIGH
PRESSURE FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM SUNDAY...
THE COLD FRONT TRAILING A 1000 MB LOW OVER THE NORTHERN CHESAPEAKE
BAY HAD SWEPT TO JUST EAST OF THE NC COASTAL PLAIN AT 20Z...WITH A
RAPID EROSION OF THE LOW CLOUD COVER IN POST-FRONTAL DOWNSLOPE
WESTERLY FLOW. SKIES WILL CONSEQUENTLY LARGELY CLEAR...IN HEIGHT
RISES ALOFT BEHIND THE NEGATIVELY-TILTED SHORTWAVE TROUGH ATTENDING
THE SURFACE LOW TO OUR NORTH. MODELS DO...HOWEVER...SUGGEST THE
LINGERING LOW LEVEL MOISTURE AND ASSOCIATED CLOUDINESS STRETCHING
ACROSS THE EASTERN PIEDMONT...SANDHILLS...AND SOUTHERN PIEDMONT THIS
AFTERNOON MAY PROVIDE FOR AN OVERNIGHT SCATTERING OF LOW CLOUDS
ALONG THE SC BORDER PER RH CROSS SECTIONS. WITH THE SATURATED GROUND
FROM THE ONE TO TWO INCHES OF RAIN THAT HAS FALLEN DURING THE PAST
12-18 HOURS...AND THE RELATIVE CLEAR AND LIGHT WNW WIND...PATCHY FOG
WILL BE POSSIBLE...PARTICULARLY OVER THE SANDHILLS AND SOUTHERN
COASTAL PLAIN...WHERE SURFACE DEWPOINTS WILL BE SLOWER TO FALL. LOWS
GENERALLY 35-40...IN LINE WITH THE VERY SIMILAR MAV-MET STATISTICAL
GUIDANCE.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 255 PM SUNDAY...
DRY COLD FRONT WILL MOVE THROUGH THE AREA AND PUSH OFF THE CAROLINA
COAST MONDAY. BRIEF LIGHT RAIN WILL DEVELOP EARLY TUESDAY... BETWEEN
06 AND 12Z... AS A WEAK TROUGH DEVELOPS ACROSS THE REGION IN
RESPONSE TO A SHORTWAVE CROSSING THE SOUTHEAST. HIGH PRESSURE WILL
BUILD IN THROUGH THE DAY TUESDAY AND REMAIN OVER THE AREA WEDNESDAY.
SEASONABLE HIGHS NEAR 50... LOWS UPPER 20S TO MID 30S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 256 PM SUNDAY...
MODELS ARE IN GOOD GENERAL AGREEMENT ON A WAVE DIGGING IN TO THE
OHIO VALLEY THURSDAY... AND THE SURFACE LOW DEVELOPS AND MOVES
ACROSS THE MIDATLANTIC/SOUTHERN NEW ENGLAND. HOWEVER... SIGNIFICANT
DIFFERENCES STILL EXIST WITH THE DEVELOPMENT AND TRACK OF A
POTENTIAL COASTAL LOW PRESSURE SYSTEM. ECMWF... AND A FEW GFS
ENSEMBLE MEMBERS... DEVELOP A LOW ALONG THE SOUTHEAST COAST... WHICH
WOULD LEAD TO GREATER PRECIPITATION FOR THIS AREA. GFS... AND MANY OF
ITS ENSEMBLE MEMBERS... ARE DRIER... WITH WEAKER OR FARTHER EASTWARD
COASTAL DEVELOPMENT. WILL CONTINUE TO CARRY SLT CHC POPS UNTIL
BETTER RESOLUTION IS REACHED.
GOOD AGREEMENT THAT COLD ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND
THE DEPARTING SYSTEM... AND REMAIN ACROSS THE AREA IN TO SUNDAY.
COLD HIGHS FRIDAY IN THE UPPER 30S... FOLLOWED BY COLD LOWS SATURDAY
MORNING... CURRENTLY ADVERTISING LOW 20S... BUT TEENS WOULD
CERTAINLY BE POSSIBLE UNDER GOOD RADIATIONAL COOLING CONDITIONS.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 730 PM SUNDAY...
VFR CONDITIONS ARE GENERALLY EXPECTED THIS EVENING. HOWEVER... A
LINGERING PATCH OF CIGS AROUND 1000-1500 FT IS SLOWLY DISSIPATING
BUT MEANDERING TOWARDS KFAY THIS EVENING. THUS... HAVE INCLUDED A
TEMPO GROUP THROUGH 02Z THIS EVENING FOR THIS LOW END MVFR CIG
THREAT. OTHERWISE... EXPECT VFR CONDITIONS WILL CONTINUE INTO THE
EARLY MORNING HOURS OF MONDAY. THE COMBINATION OF MOIST GROUNDS FROM
RECENT RAINFALL AND LIGHT AND VARIABLE WINDS OVERNIGHT MAY LEAD TO
THE FORMATION OF SOME FOG/VERY LOW STRATUS GENERALLY DURING THE PRE-
DAWN HOURS OF MONDAY MORNING. KGSO AND KINT SEEM TO HAVE THE LEAST
THREAT OF SUB-VFR CONDITIONS AND WILL ACCORDINGLY LEAVE OUT MENTION
OF SUB-VFR CONDITIONS THERE. AT KRWI AND KRDU... WILL GO WITH A
TEMPO FOR MVFR VISBYS... LOW CONFIDENCE THOUGH. THE LATEST HRRR IS
STILL SHOWING THE POTENTIAL FOR SOME IFR/LIFR FOG ACROSS SOUTHERN
PORTIONS OF CENTRAL NC... NEAR KFAY. THIS MAKES SENSE AS THIS IS
WHERE THE LINGERING LOW STRATUS IS CURRENTLY NEAR... ALONG WITH THE
EXPECTED WEAKEST PRESSURE GRADIENT BY MORNING. THUS... WILL GO WITH
A TEMPO FOR LIFR CONDITIONS THERE OVERNIGHT... ALTHOUGH CONFIDENCE
IS ONLY LOW TO MEDIUM AT BEST. EXPECT ANY SUB-VFR CONDITIONS WILL
LIFT TO VFR BY AT LEAST 12-14Z MONDAY. AN APPROACHING POTENT
DISTURBANCE ALOFT WILL ALLOW FOR SOME LOW END VFR CIGS TO RETURN BY
LATE IN THE DAY... WITH MAYBE SOME VERY LIGHT PRECIP AND SUB-VFR
CONDITIONS JUST BEYOND THE 00Z TAF PERIOD.
OUTLOOK: THE PASSAGE OF A SECONDARY COLD FRONT AND UPPER LEVEL
DISTURBANCE MAY RESULT IN A PERIOD OF SUB-VFR CONDITIONS AND A
LITTLE LIGHT RAIN MON NIGHT...AND THEN AGAIN WITH ANOTHER PASSING
STORM SYSTEM LATE IN THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...SEC
LONG TERM...SEC
AVIATION...BSD/MWS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
938 PM CST SUN DEC 29 2013
.UPDATE...
ISSUED AT 934 PM CST SUN DEC 29 2013
WITH SURFACE RIDGE AXIS ACROSS WESTERN MN RESULTING IN LIGHT WINDS AND
ADVANCING CLOUDS FROM THE WEST ALLOWING TEMPERATURES TO MODERATE
HAVE CANCELLED THE WIND ADVISORY ACROSS THE FORECAST AREA. MADE
SOME MINOR TEMPERATURE ADJUSTMENTS ACROSS THE WEST OTHERWISE
MINIMUMS SEEM REASONABLE. BASED ON CURRENT RADAR TRENDS AND
MESOSCALE MODEL GUIDANCE HAVE DELAYED MOVING -SN INTO THE W-SW FA
UNTIL AFTER MIDNIGHT.
UPDATE ISSUED AT 628 PM CST SUN DEC 29 2013
NO CHANGES PLANNED THIS UPDATE PERIOD. APPARENT TEMPERATURES NOT
VERY IMPRESSIVE AT THIS POINT WITH LIGHT WINDS BUT WILL MONITOR.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 248 PM CST SUN DEC 29 2013
FORECAST CHALLENGE TONIGHT WILL BE EASTWARD EXTEND OF CLOUDS OVER
CENTRAL NORTH DAKOTA AND THEIR IMPACT ON TEMPS AND WIND CHILL
HEADLINES. OVERALL CLOUDS ADVECTING EAST QUICKER THAN INITIALLY
THOUGHT...AND MAY MAKE DEVILS LAKE BY 00Z. MODELS HAVE STRUGGLED
TO WITH PICKING UP ON THE MOISTURE...MAINLY HIGHLIGHTING THE
HIGHER CLOUDS OVER MINOT AND WEST. USING MAINLY SATELLITE TRENDS
FOR THE NEAR TERM AND MORE OF A ECMWF/NAM BLEND FOR THE EARLY PART
OF THE WEEK.
TONIGHT...CLOUDS WILL SLOWLY SPREAD INTO EASTERN ND AND APPROACH
THE RRV BY MIDNIGHT. A RATHER BULLISH CROSS SECTION FROM RUGBY TO
GRAND FORKS BRINGS CLOUDS INTO GFK BY 03Z..WHICH I THINK IS A BIT
TOO FAST. AS STATED PREVIOUSLY...MODELS ARE STRUGGLING WITH
ESPECIALLY THE LOWER CLOUDS THAT WERE PRESENT EARLY THIS MORNING.
THE RAP AVIATION FLIGHT RULES PRODUCT BRINGS THE LOW CLOUDS INTO
THE VALLEY AROUND THE 06Z/07Z TIME FRAME...BUT MID CLOUD SHOULD
ARRIVE PRIOR TO THAT. SO THE QUESTION BECOMES HOW FAST WILL TEMPS
DROP OFF AS THE SUN ANGLE DECREASES IN THE LATE AFTN...AND THEIR
IS ENOUGH WIND TO KEEP US IN ADVISORY CRITERIA THROUGH CURRENTLY
ADVERTISED TIMES. WILL NOT MAKE ANY CHANGES TO HEADLINES AT THIS
POINT BUT MAY SEE ADVISORY CANCELLED ACROSS EASTERN ND WELL AHEAD
OF SCHEDULE IF CLOUDS CAN LEVEL OFF THE TEMP CURVE QUICK ENOUGH.
OTHER ISSUE IS THAT WINDS ARE RATHER LIGHT...BUT ONLY TAKES 2 TO 3
KNOTS IN THE COLDEST AIR TO GET APPARENT TEMPS IN ADVISORY
CRITERIA. AGAIN...WILL KEEP HEADLINES IN PLACE AS IT IS GOING TO
BE DARN COLD TONIGHT WITHIN AND EAST OF THE VALLEY.
TOMORROW AND TOMORROW NIGHT...A WEAK WAVE WILL MOVE ACROSS CENTRAL
DAKOTAS AND SHOULD RESULT IN A BAND OF VERY DRY FLUFF ACROSS THE
CENTRAL PART OF THE STATE. THIS MAY CLIP THE SHEYENNE
VALLEY...WITH THE BEST CHANCES FOR UP TO TWO INCHES OF FLUFF BEING
FROM EDDY DOWN TO RANSOM/SARGENT COUNTIES. EXPECT SNOWFALL TO BE
INTO MAINLY WEST CENTRAL MN AFTER NOON...AND OUT OF THE REGION BY
EARLY MONDAY EVENING.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 248 PM CST SUN DEC 29 2013
TUESDAY AND WEDNESDAY...A SERIES OF WAVES EMBEDDED IN THE NW FLOW
PATTERN WILL BRING MORE CHANCES OF LIGHT SNOW MAINLY IN THE FAR
WEST ON TUE AND WED. THE WED SYSTEM...ALTHOUGH WEAKER AND
DRIER...SHOULD GIVE OUR CWA A LITTLE BETTER CHANCE AS THE UPPER
PATTERN SHIFTS EAST AND THE TRACK OF THE WAVES MOVES FROM THE
CENTRAL TO THE EASTERN DAKOTAS. EACH WAVE WILL GENERALLY BE MORE
DRY FLUFF THAT MAY ACCUMULATE AN INCH OR TWO DUE TO HIGH SNOWFALL
RATIOS WITH VERY LITTLE LIQUID EQUIVALENT.
WEDNESDAY NIGHT-SUNDAY...MODELS ARE IN GOOD AGREEMENT. THE PERIOD
STARTS WITH THE REGION IN NORTHWEST FLOW ALOFT...ALONG WITH HIGH
PRESSURE AND VERY COLD TEMPERATURES. THE UPPER PATTERN THEN
DEAMPLIFIES...ALLOWING ZONAL FLOW BY THE WEEKEND. THIS WILL LEAD TO
MUCH WARMER TEMPERATURES ON FRIDAY. A SYSTEM WILL MOVE THROUGH
SOUTHERN CANADA...SENDING A COLD FRONT THROUGH THE FA LATE FRIDAY OR
EARLY SATURDAY. LIGHT SNOW AND WINDY CONDITIONS POSSIBLE WITH THIS
FEATURE...ALTHOUGH DETAILS ARE FUZZY. TEMPERATURES WILL BE A BIT
COOLER FOR THE WEEKEND (COMPARED TO FRIDAY). MODELS SHOW A MUCH
STRONGER COLD FRONT POSSIBLE FOR LATER SUNDAY OR EARLY MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 628 PM CST SUN DEC 29 2013
MAIN CHALLENGE WILL BE TO TIME GENERALLY VFR CIGS INTO THE
FORECAST AREA FROM THE WEST. ANY RESTRICTION TO VSBY IN LIGHT SNOW
WILL BE CONFINED TO THE SW FA TOWARDS MORNING AND THIS WILL LIKELY
BE MINOR.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...SPEICHER
LONG TERM...TG/SPEICHER
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
633 PM CST SUN DEC 29 2013
.UPDATE...
ISSUED AT 628 PM CST SUN DEC 29 2013
NO CHANGES PLANNED THIS UPDATE PERIOD. APPARENT TEMPERATURES NOT
VERY IMPRESSIVE AT THIS POINT WITH LIGHT WINDS BUT WILL MONITOR.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 248 PM CST SUN DEC 29 2013
FORECAST CHALLENGE TONIGHT WILL BE EASTWARD EXTEND OF CLOUDS OVER
CENTRAL NORTH DAKOTA AND THEIR IMPACT ON TEMPS AND WIND CHILL
HEADLINES. OVERALL CLOUDS ADVECTING EAST QUICKER THAN INITIALLY
THOUGHT...AND MAY MAKE DEVILS LAKE BY 00Z. MODELS HAVE STRUGGLED
TO WITH PICKING UP ON THE MOISTURE...MAINLY HIGHLIGHTING THE
HIGHER CLOUDS OVER MINOT AND WEST. USING MAINLY SATELLITE TRENDS
FOR THE NEAR TERM AND MORE OF A ECMWF/NAM BLEND FOR THE EARLY PART
OF THE WEEK.
TONIGHT...CLOUDS WILL SLOWLY SPREAD INTO EASTERN ND AND APPROACH
THE RRV BY MIDNIGHT. A RATHER BULLISH CROSS SECTION FROM RUGBY TO
GRAND FORKS BRINGS CLOUDS INTO GFK BY 03Z..WHICH I THINK IS A BIT
TOO FAST. AS STATED PREVIOUSLY...MODELS ARE STRUGGLING WITH
ESPECIALLY THE LOWER CLOUDS THAT WERE PRESENT EARLY THIS MORNING.
THE RAP AVIATION FLIGHT RULES PRODUCT BRINGS THE LOW CLOUDS INTO
THE VALLEY AROUND THE 06Z/07Z TIME FRAME...BUT MID CLOUD SHOULD
ARRIVE PRIOR TO THAT. SO THE QUESTION BECOMES HOW FAST WILL TEMPS
DROP OFF AS THE SUN ANGLE DECREASES IN THE LATE AFTN...AND THEIR
IS ENOUGH WIND TO KEEP US IN ADVISORY CRITERIA THROUGH CURRENTLY
ADVERTISED TIMES. WILL NOT MAKE ANY CHANGES TO HEADLINES AT THIS
POINT BUT MAY SEE ADVISORY CANCELLED ACROSS EASTERN ND WELL AHEAD
OF SCHEDULE IF CLOUDS CAN LEVEL OFF THE TEMP CURVE QUICK ENOUGH.
OTHER ISSUE IS THAT WINDS ARE RATHER LIGHT...BUT ONLY TAKES 2 TO 3
KNOTS IN THE COLDEST AIR TO GET APPARENT TEMPS IN ADVISORY
CRITERIA. AGAIN...WILL KEEP HEADLINES IN PLACE AS IT IS GOING TO
BE DARN COLD TONIGHT WITHIN AND EAST OF THE VALLEY.
TOMORROW AND TOMORROW NIGHT...A WEAK WAVE WILL MOVE ACROSS CENTRAL
DAKOTAS AND SHOULD RESULT IN A BAND OF VERY DRY FLUFF ACROSS THE
CENTRAL PART OF THE STATE. THIS MAY CLIP THE SHEYENNE
VALLEY...WITH THE BEST CHANCES FOR UP TO TWO INCHES OF FLUFF BEING
FROM EDDY DOWN TO RANSOM/SARGENT COUNTIES. EXPECT SNOWFALL TO BE
INTO MAINLY WEST CENTRAL MN AFTER NOON...AND OUT OF THE REGION BY
EARLY MONDAY EVENING.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 248 PM CST SUN DEC 29 2013
TUESDAY AND WEDNESDAY...A SERIES OF WAVES EMBEDDED IN THE NW FLOW
PATTERN WILL BRING MORE CHANCES OF LIGHT SNOW MAINLY IN THE FAR
WEST ON TUE AND WED. THE WED SYSTEM...ALTHOUGH WEAKER AND
DRIER...SHOULD GIVE OUR CWA A LITTLE BETTER CHANCE AS THE UPPER
PATTERN SHIFTS EAST AND THE TRACK OF THE WAVES MOVES FROM THE
CENTRAL TO THE EASTERN DAKOTAS. EACH WAVE WILL GENERALLY BE MORE
DRY FLUFF THAT MAY ACCUMULATE AN INCH OR TWO DUE TO HIGH SNOWFALL
RATIOS WITH VERY LITTLE LIQUID EQUIVALENT.
WEDNESDAY NIGHT-SUNDAY...MODELS ARE IN GOOD AGREEMENT. THE PERIOD
STARTS WITH THE REGION IN NORTHWEST FLOW ALOFT...ALONG WITH HIGH
PRESSURE AND VERY COLD TEMPERATURES. THE UPPER PATTERN THEN
DEAMPLIFIES...ALLOWING ZONAL FLOW BY THE WEEKEND. THIS WILL LEAD TO
MUCH WARMER TEMPERATURES ON FRIDAY. A SYSTEM WILL MOVE THROUGH
SOUTHERN CANADA...SENDING A COLD FRONT THROUGH THE FA LATE FRIDAY OR
EARLY SATURDAY. LIGHT SNOW AND WINDY CONDITIONS POSSIBLE WITH THIS
FEATURE...ALTHOUGH DETAILS ARE FUZZY. TEMPERATURES WILL BE A BIT
COOLER FOR THE WEEKEND (COMPARED TO FRIDAY). MODELS SHOW A MUCH
STRONGER COLD FRONT POSSIBLE FOR LATER SUNDAY OR EARLY MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 628 PM CST SUN DEC 29 2013
MAIN CHALLENGE WILL BE TO TIME GENERALLY VFR CIGS INTO THE
FORECAST AREA FROM THE WEST. ANY RESTRICTION TO VSBY IN LIGHT SNOW
WILL BE CONFINED TO THE SW FA TOWARDS MORNING AND THIS WILL LIKELY
BE MINOR.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL 9 PM CST THIS EVENING FOR NDZ038-049-
052.
WIND CHILL ADVISORY UNTIL 6 AM CST MONDAY FOR NDZ008-016-027-029-
030-039-053.
WIND CHILL ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR NDZ006-007-
014-015-024-026-028-054.
MN...WIND CHILL ADVISORY UNTIL 6 AM CST MONDAY FOR MNZ001>009-013>017-
022>024-027>032-040.
&&
$$
UPDATE...VOELKER
SHORT TERM...SPEICHER
LONG TERM...TG/SPEICHER
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
203 PM CST SAT DEC 28 2013
.UPDATE...
ISSUED AT 203 PM CST SAT DEC 28 2013
REPORTS INDICATE NEAR ZERO VSBY INTO GRIGGS AND TRAILL
COUNTIES...AND VERY STRONG WINDS HAVE EXPANDED INTO THE SOUTHERN
RED RIVER VALLEY. LATEST RAP GUIDANCE INDICATES THE POTENTIAL FOR
WINDS TO INCREASE ANOTHER 5-10 KNOTS UNTIL 00Z...THEN SLOWLY
DIMINISH. IT IS NOT TAKING MUCH FALLING SNOW TO SIGNIFICANTLY
LOWER VISIBILITIES...AND MOST GUIDANCE INDICATES -SN WILL MOVE
INTO THE SOUTHERN FA LATER THIS AFTERNOON INTO THE EARLY EVENING
HOURS. GIVEN THESE FACTORS...FEEL CONFIDENT THAT AT LEAST THE OPEN
AREAS WILL HAVE VSBY 1/4SM WHERE WINDS ARE AOA 30MPH. PLUS...GIVEN
WINDS GUSTING TO 50 MPH ALONG WITH THE RAPIDLY COOLING
TEMPS...THERE IS A DECENT CHANCE FOR THE CRUST TO BE BROKEN
ADDING TO THE AVAILABLE SNOWFALL TO BLOW AROUND.
UPDATE ISSUED AT 1242 PM CST SAT DEC 28 2013
CURRENT HEADLINES SHOULD BE IN GOOD SHAPE. AWOS/ASOS SITES HAVE
IMPROVED VSBY SLIGHTLY WITHIN THE BLIZZARD WARNING AREA...BUT
STILL GETTING REPORTS OF WHITEOUT CONDITIONS (ESPECIALLY IN OPEN
AREAS). SNOW WILL INCREASE ACROSS THIS AREA DURING THE AFTERNOON
(AND WINDS SHOULD ALSO INCREASE A BIT)...WHICH WILL AGAIN CAUSE
THE WHITEOUT CONDITIONS TO INCREASE IN COVERAGE. TO THE
SOUTH...WINDS HAVE INCREASED BUT VSBY REMAINS AOA 1/2SM. WILL NEED
TO MONITOR VSBY SINCE WINDS WILL BE QUITE STRONG...IT IS POSSIBLE
THAT THE CRUST WILL BREAK AND ALLOW FOR MORE AVAILABLE SNOW TO
BLOW AROUND.
UPDATE ISSUED AT 1106 AM CST SAT DEC 28 2013
GETTING REPORTS OF BLIZZARD CONDITIONS WITHIN GRAND FORKS
COUNTY...AS WELL AS THE MINOT AREA (WHERE MODERATE SNOW IS
FALLING). WINDS CONTINUE TO INCREASE...WITH KDVL NOW 30G34KT.
CONFIDENCE IS ENOUGH THAT AT LEAST OPEN COUNTRY WILL BE WHITEOUT
CONDITIONS...ESPECIALLY AS THE MODERATE SNOW MOVES INTO THE DEVILS
LAKE BASIN AND NORTHERN VALLEY...AND HAVE EXPANDED THE BLIZZARD
WARNING SOUTHWARD. THERE IS SOME CONCERN THAT THE CRUST IS
BREAKING APART...WHICH COULD LEAD TO BLIZZARD CONDITIONS INTO THE
SOUTHERN RED RIVER VALLEY. AT THIS TIME THINKING THIS WILL NOT
OCCUR...BUT DEFINITELY WILL NEED TO MONITOR. LATEST RAP GUIDANCE
INDICATES THE MODERATE SNOWFALL WILL NOT DROP SOUTH OF THE CURRENT
BLIZZARD AREA...SO THAT MAY BE ENOUGH TO KEEP THE SOUTHERN VALLEY
A HIGH END WINTER WX ADVISORY.
UPDATE ISSUED AT 1029 AM CST SAT DEC 28 2013
MAIN CHALLENGE WILL BE WHERE/IF BLIZZARD CONDITIONS MAY DEVELOP.
LATEST OBSERVATIONS SUGGEST THAT MOST AREAS NEAR THE INTERNATIONAL
BORDER ARE WITHIN MAINLY WHITEOUT CONDITIONS...AND WINDS CONTINUE
TO INCREASE. LATEST GUIDANCE SUGGESTS THAT MOST AREAS (ESPECIALLY
ALONG AND WEST OF THE VALLEY) WILL BE SUSTAINED 35 MPH WITH GUSTS
TO 50 MPH THIS AFTERNOON. THE LATEST RAP GUIDANCE INDICATES MIXING
AND UNIDIRECTIONAL FLOW TO 950MB...WHERE THERE IS 40-43 KNOTS
AVAILABLE. CURRENTLY...THE LOW VISIBILITIES ARE RELATED TO AREAS
THAT RECEIVED SNOWFALL OVER THE PAST 6-10 HOURS. HOWEVER...WE ARE
GETTING REPORTS THAT THE CRUST MAY BE BREAKING APART WHERE WINDS
ARE GUSTING TO NEAR 40 KNOTS. FOR NOW...HAVE UPGRADED TO A
BLIZZARD WARNING FOR AREAS NEAR THE INTERNATIONAL BORDER TO THE
NORTHERN VALLEY. THERE IS ANOTHER BAND OF SNOW...ASSOCIATED WITH
STRONG 850MB-700MB FRONTOGENESIS...THAT WILL DROP INTO THE DEVILS
LAKE BASIN AND CENTRAL RED RIVER VALLEY THIS AFTERNOON. THIS MAY
BE ENOUGH THAT THE BLIZZARD WARNING MAY NEED TO BE EXPANDED SOUTH
TO COVER THIS AREA. WILL MONITOR THE SITUATION AND LIKELY MAKE A
DECISION BY NOON/1PM.
INCREASED WIND SPEEDS IN THE GRIDS BASED ON LATEST OBSERVATIONS
AND GUIDANCE.
ALSO...INCLUDED ALL AREAS IN FREEZING DRIZZLE SOUTH OF THE MAIN
COLD AIR ADVECTION.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 359 AM CST SAT DEC 28 2013
WATER VAPOR LOOP INDICATED A SHORT WAVE OVER NORTH CENTRAL MT.
TROUGH WILL MOVE ACROSS THE FORECAST AREA TONIGHT. LEADING EDGE OF
ARCTIC AIR WAS LOCATED OVER CENTRAL MAN AND CENTRAL SASK OR THE
NORTHERN END OF LAKE WINNIPEG. ARCTIC AIR WILL SHIFT SOUTH TODAY.
ENHANCED IR SATELLITE LOOP AND ATMOSPHERIC PROFILE SUGGEST POTENTIAL
FOR FREEZING DRIZZLE FROM BJI TO CANDO ND. SOME FREEZING DRIZZLE HAS
HAS BEEN OCCURRING IN GFK THIS MORNING. WILL GO FOR FREEZING DRIZZLE
THROUGH 12Z SAT IN A ROUGHLY 90 MILE WIDE BAND FROM CANDO ND TO BJI.
EXPECT FREEZING DRIZZLE BAND TO SHIFT INTO MN SIDE FROM 12Z TO 18Z
SAT FROM ABOUT WASKISH TO CROOKSTON TO ADA TO PARK RAPIDS. FREEZING
PRECIP SHOULD MOVE EAST OF THE AREA THEREAFTER.
GOOD WINDS EXPECTED TO INCREASE LATER THIS MORNING AS SURFACE LOW
MOVES EAST. WINDS MAY GUST UP TO 40 MPH. WITH RELATIVELY MILD
TEMPERATURES YESTERDAY THE SNOW PACK IS EXPECTED TO HAVE A CRUST AS
TEMPERATURES FALL. WITH SNOW PACK CRUSTED, THEN SNOW WILL HAVE A
HARD TIME TO BLOW AROUND. ALSO SNOW AMOUNTS ARE NOT EXPECTED TO BE
AS MUCH AS THOUGHT YESTERDAY. AN INCH OR TWO OF SNOW IS FORECAST
ALONG THE INTERNATIONAL BORDER TO ONLY A DUSTING IN THE SOUTHERN RED
RIVER VALLEY. SO IF ANY POTENTIAL FOR BLIZZARD CONDITIONS WOULD BE
IN THE NORTHERN RED RIVER VALLEY WITH THE FALLING SNOW.
MESO SCALE ANALYSIS SHOWED BEST PRESSURE RISES AND LOW LEVEL COLD
ADVECTION WERE OCCURRING OVER NORTHWEST MT OR WEST OF THE SURFACE
LOW. SURFACE LOW WILL MOVE INTO SOUTHWEST MN THIS AFTERNOON.
WITH SUCH A WIDE VARIETY OF WEATHER EXPECTED TODAY, WILL ISSUE A
BLANKET WINTER WEATHER ADVISORY FOR THE ENTIRE AREA. LATER SHIFTS
WILL HAVE TO MONITOR FOR POTENTIAL BLIZZARD CONDITIONS FOR TODAY AND
TONIGHT AND AMEND IF NECESSARY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 359 AM CST SAT DEC 28 2013
TUE THROUGH FRI...
IT WILL BE BITTERLY COLD TO BEGIN THE PERIOD WITH MODERATION BY NEXT
THU/FRI. THE BEST CHANCE FOR SOME LIGHT SNOW SHOULD COME BY THE
MIDDLE OF NEXT WEEK NEAR INCREASING MID LEVEL WAA...BUT NO MAJOR
STORMS EXPECTED...WITH THE MAIN WEATHER STORY BEING THE BRUTAL COLD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1242 PM CST SAT DEC 28 2013
EXPECT WIDESPREAD IFR CONDITIONS TODAY WITH CIGS GENERALLY RANGING
FROM 300 TO 500 FEET. SURFACE VISIBILITIES IN THE VALLEY AND ACROSS
EASTERN NORTH DAKOTA WILL RANGE FROM WHITE OUT CONDITIONS IN THE
NORTH TO ONE HALF TO TWO MILES ACROSS THE SOUTH AS NORTHERLY WINDS
GUST FROM 40 TO 50 MPH. WINDS WILL DECREASE FURTHER EAST...BUT STILL
RESULT IN SOME AREAS OF BLOWING SNOW. CONDITIONS WILL NOT IMPROVE
UNTIL LATE IN THE EVENING...AS CLOUDS CLEAR OUT AND WINDS DECLINE
ENOUGH TO END THE BLOWING SNOW.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...BLIZZARD WARNING UNTIL MIDNIGHT CST TONIGHT FOR NDZ028>030-038-
039-049-052-053.
BLIZZARD WARNING UNTIL 9 PM CST THIS EVENING FOR NDZ006>008-
014>016-024-026-027-054.
MN...BLIZZARD WARNING UNTIL MIDNIGHT CST TONIGHT FOR MNZ002-003-029-
030-040.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ005-
006-008-009-013>017-022>024-027-028-031-032.
BLIZZARD WARNING UNTIL 9 PM CST THIS EVENING FOR MNZ001-004-007.
&&
$$
UPDATE...TG
SHORT TERM...HOPPES
LONG TERM...DK
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1242 PM CST SAT DEC 28 2013
.UPDATE...
ISSUED AT 1242 PM CST SAT DEC 28 2013
CURRENT HEADLINES SHOULD BE IN GOOD SHAPE. AWOS/ASOS SITES HAVE
IMPROVED VSBY SLIGHTLY WITHIN THE BLIZZARD WARNING AREA...BUT
STILL GETTING REPORTS OF WHITEOUT CONDITIONS (ESPECIALLY IN OPEN
AREAS). SNOW WILL INCREASE ACROSS THIS AREA DURING THE AFTERNOON
(AND WINDS SHOULD ALSO INCREASE A BIT)...WHICH WILL AGAIN CAUSE
THE WHITEOUT CONDITIONS TO INCREASE IN COVERAGE. TO THE
SOUTH...WINDS HAVE INCREASED BUT VSBY REMAINS AOA 1/2SM. WILL NEED
TO MONITOR VSBY SINCE WINDS WILL BE QUITE STRONG...IT IS POSSIBLE
THAT THE CRUST WILL BREAK AND ALLOW FOR MORE AVAILABLE SNOW TO
BLOW AROUND.
UPDATE ISSUED AT 1106 AM CST SAT DEC 28 2013
GETTING REPORTS OF BLIZZARD CONDITIONS WITHIN GRAND FORKS
COUNTY...AS WELL AS THE MINOT AREA (WHERE MODERATE SNOW IS
FALLING). WINDS CONTINUE TO INCREASE...WITH KDVL NOW 30G34KT.
CONFIDENCE IS ENOUGH THAT AT LEAST OPEN COUNTRY WILL BE WHITEOUT
CONDITIONS...ESPECIALLY AS THE MODERATE SNOW MOVES INTO THE DEVILS
LAKE BASIN AND NORTHERN VALLEY...AND HAVE EXPANDED THE BLIZZARD
WARNING SOUTHWARD. THERE IS SOME CONCERN THAT THE CRUST IS
BREAKING APART...WHICH COULD LEAD TO BLIZZARD CONDITIONS INTO THE
SOUTHERN RED RIVER VALLEY. AT THIS TIME THINKING THIS WILL NOT
OCCUR...BUT DEFINITELY WILL NEED TO MONITOR. LATEST RAP GUIDANCE
INDICATES THE MODERATE SNOWFALL WILL NOT DROP SOUTH OF THE CURRENT
BLIZZARD AREA...SO THAT MAY BE ENOUGH TO KEEP THE SOUTHERN VALLEY
A HIGH END WINTER WX ADVISORY.
UPDATE ISSUED AT 1029 AM CST SAT DEC 28 2013
MAIN CHALLENGE WILL BE WHERE/IF BLIZZARD CONDITIONS MAY DEVELOP.
LATEST OBSERVATIONS SUGGEST THAT MOST AREAS NEAR THE INTERNATIONAL
BORDER ARE WITHIN MAINLY WHITEOUT CONDITIONS...AND WINDS CONTINUE
TO INCREASE. LATEST GUIDANCE SUGGESTS THAT MOST AREAS (ESPECIALLY
ALONG AND WEST OF THE VALLEY) WILL BE SUSTAINED 35 MPH WITH GUSTS
TO 50 MPH THIS AFTERNOON. THE LATEST RAP GUIDANCE INDICATES MIXING
AND UNIDIRECTIONAL FLOW TO 950MB...WHERE THERE IS 40-43 KNOTS
AVAILABLE. CURRENTLY...THE LOW VISIBILITIES ARE RELATED TO AREAS
THAT RECEIVED SNOWFALL OVER THE PAST 6-10 HOURS. HOWEVER...WE ARE
GETTING REPORTS THAT THE CRUST MAY BE BREAKING APART WHERE WINDS
ARE GUSTING TO NEAR 40 KNOTS. FOR NOW...HAVE UPGRADED TO A
BLIZZARD WARNING FOR AREAS NEAR THE INTERNATIONAL BORDER TO THE
NORTHERN VALLEY. THERE IS ANOTHER BAND OF SNOW...ASSOCIATED WITH
STRONG 850MB-700MB FRONTOGENESIS...THAT WILL DROP INTO THE DEVILS
LAKE BASIN AND CENTRAL RED RIVER VALLEY THIS AFTERNOON. THIS MAY
BE ENOUGH THAT THE BLIZZARD WARNING MAY NEED TO BE EXPANDED SOUTH
TO COVER THIS AREA. WILL MONITOR THE SITUATION AND LIKELY MAKE A
DECISION BY NOON/1PM.
INCREASED WIND SPEEDS IN THE GRIDS BASED ON LATEST OBSERVATIONS
AND GUIDANCE.
ALSO...INCLUDED ALL AREAS IN FREEZING DRIZZLE SOUTH OF THE MAIN
COLD AIR ADVECTION.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 359 AM CST SAT DEC 28 2013
WATER VAPOR LOOP INDICATED A SHORT WAVE OVER NORTH CENTRAL MT.
TROUGH WILL MOVE ACROSS THE FORECAST AREA TONIGHT. LEADING EDGE OF
ARCTIC AIR WAS LOCATED OVER CENTRAL MAN AND CENTRAL SASK OR THE
NORTHERN END OF LAKE WINNIPEG. ARCTIC AIR WILL SHIFT SOUTH TODAY.
ENHANCED IR SATELLITE LOOP AND ATMOSPHERIC PROFILE SUGGEST POTENTIAL
FOR FREEZING DRIZZLE FROM BJI TO CANDO ND. SOME FREEZING DRIZZLE HAS
HAS BEEN OCCURRING IN GFK THIS MORNING. WILL GO FOR FREEZING DRIZZLE
THROUGH 12Z SAT IN A ROUGHLY 90 MILE WIDE BAND FROM CANDO ND TO BJI.
EXPECT FREEZING DRIZZLE BAND TO SHIFT INTO MN SIDE FROM 12Z TO 18Z
SAT FROM ABOUT WASKISH TO CROOKSTON TO ADA TO PARK RAPIDS. FREEZING
PRECIP SHOULD MOVE EAST OF THE AREA THEREAFTER.
GOOD WINDS EXPECTED TO INCREASE LATER THIS MORNING AS SURFACE LOW
MOVES EAST. WINDS MAY GUST UP TO 40 MPH. WITH RELATIVELY MILD
TEMPERATURES YESTERDAY THE SNOW PACK IS EXPECTED TO HAVE A CRUST AS
TEMPERATURES FALL. WITH SNOW PACK CRUSTED, THEN SNOW WILL HAVE A
HARD TIME TO BLOW AROUND. ALSO SNOW AMOUNTS ARE NOT EXPECTED TO BE
AS MUCH AS THOUGHT YESTERDAY. AN INCH OR TWO OF SNOW IS FORECAST
ALONG THE INTERNATIONAL BORDER TO ONLY A DUSTING IN THE SOUTHERN RED
RIVER VALLEY. SO IF ANY POTENTIAL FOR BLIZZARD CONDITIONS WOULD BE
IN THE NORTHERN RED RIVER VALLEY WITH THE FALLING SNOW.
MESO SCALE ANALYSIS SHOWED BEST PRESSURE RISES AND LOW LEVEL COLD
ADVECTION WERE OCCURRING OVER NORTHWEST MT OR WEST OF THE SURFACE
LOW. SURFACE LOW WILL MOVE INTO SOUTHWEST MN THIS AFTERNOON.
WITH SUCH A WIDE VARIETY OF WEATHER EXPECTED TODAY, WILL ISSUE A
BLANKET WINTER WEATHER ADVISORY FOR THE ENTIRE AREA. LATER SHIFTS
WILL HAVE TO MONITOR FOR POTENTIAL BLIZZARD CONDITIONS FOR TODAY AND
TONIGHT AND AMEND IF NECESSARY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 359 AM CST SAT DEC 28 2013
TUE THROUGH FRI...
IT WILL BE BITTERLY COLD TO BEGIN THE PERIOD WITH MODERATION BY NEXT
THU/FRI. THE BEST CHANCE FOR SOME LIGHT SNOW SHOULD COME BY THE
MIDDLE OF NEXT WEEK NEAR INCREASING MID LEVEL WAA...BUT NO MAJOR
STORMS EXPECTED...WITH THE MAIN WEATHER STORY BEING THE BRUTAL COLD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1242 PM CST SAT DEC 28 2013
EXPECT WIDESPREAD IFR CONDITIONS TODAY WITH CIGS GENERALLY RANGING
FROM 300 TO 500 FEET. SURFACE VISIBILITIES IN THE VALLEY AND ACROSS
EASTERN NORTH DAKOTA WILL RANGE FROM WHITE OUT CONDITIONS IN THE
NORTH TO ONE HALF TO TWO MILES ACROSS THE SOUTH AS NORTHERLY WINDS
GUST FROM 40 TO 50 MPH. WINDS WILL DECREASE FURTHER EAST...BUT STILL
RESULT IN SOME AREAS OF BLOWING SNOW. CONDITIONS WILL NOT IMPROVE
UNTIL LATE IN THE EVENING...AS CLOUDS CLEAR OUT AND WINDS DECLINE
ENOUGH TO END THE BLOWING SNOW.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
NDZ028>030-038-039-049-052-053.
BLIZZARD WARNING UNTIL 9 PM CST THIS EVENING FOR NDZ006>008-
014>016-024-026-027-054.
MN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ002-
003-005-006-008-009-013>017-022>024-027>032-040.
BLIZZARD WARNING UNTIL 9 PM CST THIS EVENING FOR MNZ001-004-007.
&&
$$
UPDATE...TG
SHORT TERM...HOPPES
LONG TERM...DK
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1106 AM CST SAT DEC 28 2013
.UPDATE...
ISSUED AT 1106 AM CST SAT DEC 28 2013
GETTING REPORTS OF BLIZZARD CONDITIONS WITHIN GRAND FORKS
COUNTY...AS WELL AS THE MINOT AREA (WHERE MODERATE SNOW IS
FALLING). WINDS CONTINUE TO INCREASE...WITH KDVL NOW 30G34KT.
CONFIDENCE IS ENOUGH THAT AT LEAST OPEN COUNTRY WILL BE WHITEOUT
CONDITIONS...ESPECIALLY AS THE MODERATE SNOW MOVES INTO THE DEVILS
LAKE BASIN AND NORTHERN VALLEY...AND HAVE EXPANDED THE BLIZZARD
WARNING SOUTHWARD. THERE IS SOME CONCERN THAT THE CRUST IS
BREAKING APART...WHICH COULD LEAD TO BLIZZARD CONDITIONS INTO THE
SOUTHERN RED RIVER VALLEY. AT THIS TIME THINKING THIS WILL NOT
OCCUR...BUT DEFINITELY WILL NEED TO MONITOR. LATEST RAP GUIDANCE
INDICATES THE MODERATE SNOWFALL WILL NOT DROP SOUTH OF THE CURRENT
BLIZZARD AREA...SO THAT MAY BE ENOUGH TO KEEP THE SOUTHERN VALLEY
A HIGH END WINTER WX ADVISORY.
UPDATE ISSUED AT 1029 AM CST SAT DEC 28 2013
MAIN CHALLENGE WILL BE WHERE/IF BLIZZARD CONDITIONS MAY DEVELOP.
LATEST OBSERVATIONS SUGGEST THAT MOST AREAS NEAR THE INTERNATIONAL
BORDER ARE WITHIN MAINLY WHITEOUT CONDITIONS...AND WINDS CONTINUE
TO INCREASE. LATEST GUIDANCE SUGGESTS THAT MOST AREAS (ESPECIALLY
ALONG AND WEST OF THE VALLEY) WILL BE SUSTAINED 35 MPH WITH GUSTS
TO 50 MPH THIS AFTERNOON. THE LATEST RAP GUIDANCE INDICATES MIXING
AND UNIDIRECTIONAL FLOW TO 950MB...WHERE THERE IS 40-43 KNOTS
AVAILABLE. CURRENTLY...THE LOW VISIBILITIES ARE RELATED TO AREAS
THAT RECEIVED SNOWFALL OVER THE PAST 6-10 HOURS. HOWEVER...WE ARE
GETTING REPORTS THAT THE CRUST MAY BE BREAKING APART WHERE WINDS
ARE GUSTING TO NEAR 40 KNOTS. FOR NOW...HAVE UPGRADED TO A
BLIZZARD WARNING FOR AREAS NEAR THE INTERNATIONAL BORDER TO THE
NORTHERN VALLEY. THERE IS ANOTHER BAND OF SNOW...ASSOCIATED WITH
STRONG 850MB-700MB FRONTOGENESIS...THAT WILL DROP INTO THE DEVILS
LAKE BASIN AND CENTRAL RED RIVER VALLEY THIS AFTERNOON. THIS MAY
BE ENOUGH THAT THE BLIZZARD WARNING MAY NEED TO BE EXPANDED SOUTH
TO COVER THIS AREA. WILL MONITOR THE SITUATION AND LIKELY MAKE A
DECISION BY NOON/1PM.
INCREASED WIND SPEEDS IN THE GRIDS BASED ON LATEST OBSERVATIONS
AND GUIDANCE.
ALSO...INCLUDED ALL AREAS IN FREEZING DRIZZLE SOUTH OF THE MAIN
COLD AIR ADVECTION.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 359 AM CST SAT DEC 28 2013
WATER VAPOR LOOP INDICATED A SHORT WAVE OVER NORTH CENTRAL MT.
TROUGH WILL MOVE ACROSS THE FORECAST AREA TONIGHT. LEADING EDGE OF
ARCTIC AIR WAS LOCATED OVER CENTRAL MAN AND CENTRAL SASK OR THE
NORTHERN END OF LAKE WINNIPEG. ARCTIC AIR WILL SHIFT SOUTH TODAY.
ENHANCED IR SATELLITE LOOP AND ATMOSPHERIC PROFILE SUGGEST POTENTIAL
FOR FREEZING DRIZZLE FROM BJI TO CANDO ND. SOME FREEZING DRIZZLE HAS
HAS BEEN OCCURRING IN GFK THIS MORNING. WILL GO FOR FREEZING DRIZZLE
THROUGH 12Z SAT IN A ROUGHLY 90 MILE WIDE BAND FROM CANDO ND TO BJI.
EXPECT FREEZING DRIZZLE BAND TO SHIFT INTO MN SIDE FROM 12Z TO 18Z
SAT FROM ABOUT WASKISH TO CROOKSTON TO ADA TO PARK RAPIDS. FREEZING
PRECIP SHOULD MOVE EAST OF THE AREA THEREAFTER.
GOOD WINDS EXPECTED TO INCREASE LATER THIS MORNING AS SURFACE LOW
MOVES EAST. WINDS MAY GUST UP TO 40 MPH. WITH RELATIVELY MILD
TEMPERATURES YESTERDAY THE SNOW PACK IS EXPECTED TO HAVE A CRUST AS
TEMPERATURES FALL. WITH SNOW PACK CRUSTED, THEN SNOW WILL HAVE A
HARD TIME TO BLOW AROUND. ALSO SNOW AMOUNTS ARE NOT EXPECTED TO BE
AS MUCH AS THOUGHT YESTERDAY. AN INCH OR TWO OF SNOW IS FORECAST
ALONG THE INTERNATIONAL BORDER TO ONLY A DUSTING IN THE SOUTHERN RED
RIVER VALLEY. SO IF ANY POTENTIAL FOR BLIZZARD CONDITIONS WOULD BE
IN THE NORTHERN RED RIVER VALLEY WITH THE FALLING SNOW.
MESO SCALE ANALYSIS SHOWED BEST PRESSURE RISES AND LOW LEVEL COLD
ADVECTION WERE OCCURRING OVER NORTHWEST MT OR WEST OF THE SURFACE
LOW. SURFACE LOW WILL MOVE INTO SOUTHWEST MN THIS AFTERNOON.
WITH SUCH A WIDE VARIETY OF WEATHER EXPECTED TODAY, WILL ISSUE A
BLANKET WINTER WEATHER ADVISORY FOR THE ENTIRE AREA. LATER SHIFTS
WILL HAVE TO MONITOR FOR POTENTIAL BLIZZARD CONDITIONS FOR TODAY AND
TONIGHT AND AMEND IF NECESSARY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 359 AM CST SAT DEC 28 2013
TUE THROUGH FRI...
IT WILL BE BITTERLY COLD TO BEGIN THE PERIOD WITH MODERATION BY NEXT
THU/FRI. THE BEST CHANCE FOR SOME LIGHT SNOW SHOULD COME BY THE
MIDDLE OF NEXT WEEK NEAR INCREASING MID LEVEL WAA...BUT NO MAJOR
STORMS EXPECTED...WITH THE MAIN WEATHER STORY BEING THE BRUTAL COLD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 703 AM CST SAT DEC 28 2013
IFR CONDITIONS WERE LOCATED OVER THE NORTHEAST HALF OF THE FORECAST
AREA. SATELLITE LOOP/SURFACE OBS INDICATE HIGH CLOUDS COVER THE
AREA. EXPECT IFR CONDITIONS WILL SPREAD SOUTH FOR TODAY WITH PASSAGE
OF SURFACE LOW PRESSURE SYSTEM. VFR CONDITIONS MAY BE POSSIBLE OVER
EASTERN NORTH DAKOTA AFTER MID EVENING. EXPECT NORTH WIND OF 20 TO
30 MPH WITH HIGHER GUST FOR TODAY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
NDZ028>030-038-039-049-052-053.
BLIZZARD WARNING UNTIL 9 PM CST THIS EVENING FOR NDZ006>008-
014>016-024-026-027-054.
MN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ002-
003-005-006-008-009-013>017-022>024-027>032-040.
BLIZZARD WARNING UNTIL 9 PM CST THIS EVENING FOR MNZ001-004-007.
&&
$$
UPDATE...TG
SHORT TERM...HOPPES
LONG TERM...DK
AVIATION...HOPPES
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1029 AM CST SAT DEC 28 2013
.UPDATE...
ISSUED AT 1029 AM CST SAT DEC 28 2013
MAIN CHALLENGE WILL BE WHERE/IF BLIZZARD CONDITIONS MAY DEVELOP.
LATEST OBSERVATIONS SUGGEST THAT MOST AREAS NEAR THE INTERNATIONAL
BORDER ARE WITHIN MAINLY WHITEOUT CONDITIONS...AND WINDS CONTINUE
TO INCREASE. LATEST GUIDANCE SUGGESTS THAT MOST AREAS (ESPECIALLY
ALONG AND WEST OF THE VALLEY) WILL BE SUSTAINED 35 MPH WITH GUSTS
TO 50 MPH THIS AFTERNOON. THE LATEST RAP GUIDANCE INDICATES MIXING
AND UNIDIRECTIONAL FLOW TO 950MB...WHERE THERE IS 40-43 KNOTS
AVAILABLE. CURRENTLY...THE LOW VISIBILITIES ARE RELATED TO AREAS
THAT RECEIVED SNOWFALL OVER THE PAST 6-10 HOURS. HOWEVER...WE ARE
GETTING REPORTS THAT THE CRUST MAY BE BREAKING APART WHERE WINDS
ARE GUSTING TO NEAR 40 KNOTS. FOR NOW...HAVE UPGRADED TO A
BLIZZARD WARNING FOR AREAS NEAR THE INTERNATIONAL BORDER TO THE
NORTHERN VALLEY. THERE IS ANOTHER BAND OF SNOW...ASSOCIATED WITH
STRONG 850MB-700MB FRONTOGENESIS...THAT WILL DROP INTO THE DEVILS
LAKE BASIN AND CENTRAL RED RIVER VALLEY THIS AFTERNOON. THIS MAY
BE ENOUGH THAT THE BLIZZARD WARNING MAY NEED TO BE EXPANDED SOUTH
TO COVER THIS AREA. WILL MONITOR THE SITUATION AND LIKELY MAKE A
DECISION BY NOON/1PM.
INCREASED WIND SPEEDS IN THE GRIDS BASED ON LATEST OBSERVATIONS
AND GUIDANCE.
ALSO...INCLUDED ALL AREAS IN FREEZING DRIZZLE SOUTH OF THE MAIN
COLD AIR ADVECTION.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 359 AM CST SAT DEC 28 2013
WATER VAPOR LOOP INDICATED A SHORT WAVE OVER NORTH CENTRAL MT.
TROUGH WILL MOVE ACROSS THE FORECAST AREA TONIGHT. LEADING EDGE OF
ARCTIC AIR WAS LOCATED OVER CENTRAL MAN AND CENTRAL SASK OR THE
NORTHERN END OF LAKE WINNIPEG. ARCTIC AIR WILL SHIFT SOUTH TODAY.
ENHANCED IR SATELLITE LOOP AND ATMOSPHERIC PROFILE SUGGEST POTENTIAL
FOR FREEZING DRIZZLE FROM BJI TO CANDO ND. SOME FREEZING DRIZZLE HAS
HAS BEEN OCCURRING IN GFK THIS MORNING. WILL GO FOR FREEZING DRIZZLE
THROUGH 12Z SAT IN A ROUGHLY 90 MILE WIDE BAND FROM CANDO ND TO BJI.
EXPECT FREEZING DRIZZLE BAND TO SHIFT INTO MN SIDE FROM 12Z TO 18Z
SAT FROM ABOUT WASKISH TO CROOKSTON TO ADA TO PARK RAPIDS. FREEZING
PRECIP SHOULD MOVE EAST OF THE AREA THEREAFTER.
GOOD WINDS EXPECTED TO INCREASE LATER THIS MORNING AS SURFACE LOW
MOVES EAST. WINDS MAY GUST UP TO 40 MPH. WITH RELATIVELY MILD
TEMPERATURES YESTERDAY THE SNOW PACK IS EXPECTED TO HAVE A CRUST AS
TEMPERATURES FALL. WITH SNOW PACK CRUSTED, THEN SNOW WILL HAVE A
HARD TIME TO BLOW AROUND. ALSO SNOW AMOUNTS ARE NOT EXPECTED TO BE
AS MUCH AS THOUGHT YESTERDAY. AN INCH OR TWO OF SNOW IS FORECAST
ALONG THE INTERNATIONAL BORDER TO ONLY A DUSTING IN THE SOUTHERN RED
RIVER VALLEY. SO IF ANY POTENTIAL FOR BLIZZARD CONDITIONS WOULD BE
IN THE NORTHERN RED RIVER VALLEY WITH THE FALLING SNOW.
MESO SCALE ANALYSIS SHOWED BEST PRESSURE RISES AND LOW LEVEL COLD
ADVECTION WERE OCCURRING OVER NORTHWEST MT OR WEST OF THE SURFACE
LOW. SURFACE LOW WILL MOVE INTO SOUTHWEST MN THIS AFTERNOON.
WITH SUCH A WIDE VARIETY OF WEATHER EXPECTED TODAY, WILL ISSUE A
BLANKET WINTER WEATHER ADVISORY FOR THE ENTIRE AREA. LATER SHIFTS
WILL HAVE TO MONITOR FOR POTENTIAL BLIZZARD CONDITIONS FOR TODAY AND
TONIGHT AND AMEND IF NECESSARY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 359 AM CST SAT DEC 28 2013
TUE THROUGH FRI...
IT WILL BE BITTERLY COLD TO BEGIN THE PERIOD WITH MODERATION BY NEXT
THU/FRI. THE BEST CHANCE FOR SOME LIGHT SNOW SHOULD COME BY THE
MIDDLE OF NEXT WEEK NEAR INCREASING MID LEVEL WAA...BUT NO MAJOR
STORMS EXPECTED...WITH THE MAIN WEATHER STORY BEING THE BRUTAL COLD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 703 AM CST SAT DEC 28 2013
IFR CONDITIONS WERE LOCATED OVER THE NORTHEAST HALF OF THE FORECAST
AREA. SATELLITE LOOP/SURFACE OBS INDICATE HIGH CLOUDS COVER THE
AREA. EXPECT IFR CONDITIONS WILL SPREAD SOUTH FOR TODAY WITH PASSAGE
OF SURFACE LOW PRESSURE SYSTEM. VFR CONDITIONS MAY BE POSSIBLE OVER
EASTERN NORTH DAKOTA AFTER MID EVENING. EXPECT NORTH WIND OF 20 TO
30 MPH WITH HIGHER GUST FOR TODAY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR NDZ014-
015-024-026>030-038-039-049-052-053.
BLIZZARD WARNING UNTIL 6 PM CST THIS EVENING FOR NDZ006>008-016-
054.
MN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
MNZ001>003-005-006-008-009-013>017-022>024-027>032-040.
BLIZZARD WARNING UNTIL 6 PM CST THIS EVENING FOR MNZ004-007.
&&
$$
UPDATE...TG
SHORT TERM...HOPPES
LONG TERM...DK
AVIATION...HOPPES
AREA FORECAST DISCUSSION
NWS MIAMI FL
306 AM EST MON DEC 30 2013
.SHORT TERM (TODAY-WEDNESDAY)...
A LARGE SCALE MID/UPPER LEVEL TROUGH COVERS MOST OF EASTERN NORTH
AMERICA AT THIS TIME WITH A WEAKENING COLD FRONT NEAR OR JUST
SOUTH OF LAKE OKEECHOBEE EARLY THIS MORNING. THIS FRONT WILL ONLY
SAG VERY SLOWLY SOUTH AND STALL ACROSS EXTREME SOUTH FLORIDA LATER
TODAY. THIS IS DUE TO THE FACT THAT THE SUBTROPICAL RIDGE WILL
REMAIN ANCHORED ACROSS THE CARIBBEAN AND EXTEND NORTHEAST OVER
EASTERN CUBA AND INTO THE CENTRAL ATLANTIC. SOME PATCHY DENSE FOG
AND A LOW STRATUS DECK HAVE DEVELOPED ACROSS MUCH OF SOUTH FLORIDA
THIS MORNING AS A SURFACE BASED INVERSION HAS FORMED ALONG AND
AHEAD OF THE FRONT. EVEN AS THESE CLOUDS MIX OUT SHORTLY AFTER
SUNRISE, ABUNDANT MID LEVEL CLOUDS WILL LINGER WITH THE STALLING
FRONT AND POSSIBLY A FEW SHOWERS. THE NAM IS SUFFERING FROM ITS
TYPICAL MESOSCALE BIAS AND ITS HIGH POPS SEEM WAY OUT OF LINE AND
WENT MUCH CLOSER TO THE GFS AND ECMWF SOLUTIONS. THE HRRR ALSO
WAS NOT SHOWING MUCH SHOWER ACTIVITY THROUGH 16Z ALTHOUGH IT HAS
NOT RUN SINCE 01Z. STRONGER HIGH PRESSURE WILL BUILD OVER THE
SOUTHEAST STATES ON TUESDAY AS THE REMAINS OF AN ARCTIC COLD FRONT
MOVE INTO NORTH FLORIDA AND IT TOO WILL RAPIDLY BECOME DIFFUSE AS
THE RIDGE TO OUR SOUTH MOVES LITTLE. THIS WILL CREATE BREEZY
CONDITIONS ALONG OR NEAR THE ATLANTIC COAST WITH A FEW POSSIBLE
SHOWERS MOVING ONSHORE. BY NEW YEARS` DAY, A MID LEVEL TROUGH THAT
IS CURRENTLY OVER NORTHERN MEXICO WILL LIFT TO THE NORTHEAST INTO
THE SOUTHERN TIER OF STATES GENERATING A SURFACE LOW IN THE GULF
OF MEXICO. THE MODELS HAD BEEN INDICATING THE BAND OF MOISTURE
WOULD LINGER ACROSS SOUTH FLORIDA THROUGH THIS PERIOD BUT NOW SHOW
THE MOISTURE FIELD SHIFTING NORTHWARD ON WEDNESDAY. THE NAM IS THE
MOST AGGRESSIVE WITH SIGNIFICANT DRYING OCCURRING AND IT SHOWS PWAT
DROPPING TO UNDER AN INCH WHEREAS THE GFS AND ECMWF HAVE THE PWAT
HOVERING IN THE 1.25 TO 1.5 INCH RANGE. SO THERE COULD STILL BE A
FEW SHOWERS BUT IF THE NAM VERIFIES THERE WILL BE LITTLE IN THE
WAY OF CLOUD COVER.
.LONG TERM (THURSDAY-SUNDAY)...
THE MOST SIGNIFICANT CHANGE IN THE LONG TERM CONTINUES TO BE THE
THREAT OF A STRONGER COLD FRONT. ALL MODELS ARE IN GOOD AGREEMENT
THAT A STRONG MID LEVEL TROUGH WILL MOVE INTO NEW ENGLAND EARLY
FRIDAY WITH ITS TRAILING COLD FRONT MOVING THROUGH SOUTH FLORIDA.
HOWEVER, THERE ALSO CONTINUES TO BE SOME DISCREPANCY AS TO HOW
COOL IT WILL GET BEHIND THE FRONT. THE ECMWF IS STILL THE MOST
AGGRESSIVE AND SHOWING MUCH COOLER TEMPERATURES FOR THE REGION
FRIDAY AND SATURDAY MORNING THAN THE OPERATIONAL GFS WHICH IS THE
WARMER MODEL WITH A RANGE ON SATURDAY MORNING FROM THE MID TO
UPPER 40S WEST OF LAKE OKEECHOBEE TO THE MID 60S ALONG THE
SOUTHEAST COAST. BUT THE GFS ENSEMBLE RUN HAS A 15-20 DEGREE RANGE
BETWEEN THE COOLEST AND WARMEST PERTURBATIONS ACROSS SOUTH FLORIDA
WITH POSSIBLE UPPER 30S OVER GLADES AND HENDRY COUNTIES. SO AT
THIS TIME, IT CONTINUES TO BE A WAIT AND SEE APPROACH AND WILL
STAY CLOSE TO THE MEX NUMBERS UNTIL THE MODEL HAS SOME MORE
CONSISTENCY BETWEEN RUNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 80 68 78 69 / 20 20 20 20
FORT LAUDERDALE 79 70 77 72 / 20 20 20 20
MIAMI 81 70 78 71 / 20 20 20 20
NAPLES 77 64 76 64 / 20 20 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR FAR SOUTH
MIAMI DADE-INLAND BROWARD-INLAND COLLIER-INLAND MIAMI DADE-
METRO BROWARD.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...30/KOB
AVIATION/RADAR...13/SI
AREA FORECAST DISCUSSION
NWS GRAY ME
1154 PM EST SUN DEC 29 2013
.SYNOPSIS...
LOW PRESSURE WILL MOVE RAPIDLY THROUGH THE GULF OF MAINE OVERNIGHT
AND BE LOCATED NEAR HALIFAX NOVA SCOTIA BY MONDAY MORNING. HIGH
PRESSURE WILL BUILD OVER THE REGION MONDAY. WEAK LOW PRESSURE WILL
MOVE THROUGH CENTRAL NEW ENGLAND TUESDAY AFTERNOON. HIGH PRESSURE
WILL BUILD OVER THE REGION WEDNESDAY. LOW PRESSURE WILL GATHER
STRENGTH OVER THE MID ATLANTIC STATES THURSDAY AND MOVE NORTHEAST
SOUTH OF CAPE COD FRIDAY. HIGH PRESSURE WILL BUILD OVER THE
NORTHEAST SATURDAY AND MOVE SOUTHEAST OF THE REGION SUNDAY.
&&
.NEAR TERM /UNTIL 7 AM MONDAY MORNING/...
1150 PM...SNOW WAS ENDING RAPIDLY FROM SOUTHWEST TO NORTHEAST
ACROSS THE FORECAST AREA. ALL WINTER WEATHER HEADLINES FROM THE
PORTLAND AREA AND POINTS WEST AND SOUTHWEST WERE DROPPED WITH THIS
ESTF UPDATE.
PREV DISC...
UPDATED TO DROP THE WINTER WX HEADLINES FOR COASTAL CUMBERLAND AND
COASTAL YORK COUNTIES IN SW MAINE AND FOR INTERIOR ROCKINGHAM
COUNTY IN SE NH. PRCP HAS BEEN MOSTLY RAIN WITH SOME MIX OR CHANGE
OVER TO SN BUT ANY ACCUMULATIONS HAVE BEEN AN OR OR LESS FOR THESE
AREAS WITH PERHAPS A COUPLE INCHES WELL AWAY FROM THE COAST. ANY
ADDITIONAL SNOW ACCUMULATIONS WILL GIVE TOTALS NO MORE THAN 2-4
INCHES IN THESE AREAS...WITH EVEN LESS ALONG THE SHORE LINE.
PREVIOUS DISCUSSION...
UPDATED TO INPUT LATEST OBSERVED DATA. STILL SEEING MIXED PRCP OR
RAIN SRN NH AND COASTAL INTO ADJACENT INTERIOR AREAS THIS EVE.
BACK EDGE OF PRCP ALREADY MOVING INTO NY STATE AS SUPPORTED BY
MODELS MOVING SYSTEM THRU REAL FAST...BY 06Z IT`S OVER FOR ALL BUT
MAYBE EXTREME ERN ZONES. WILL BE TOUGH TO GET HIGH SNOW TOTALS...
ESPECIALLY WITH RAIN AND MIXED AT THIS TIME WHICH WILL CUT INTO
TOTAL QPF AMOUNTS AVBL FOR PRODUCING SNOW. WON`T BACK OFF ON
HEADLINES YET...BUT WILL BE UPDATING THIS EVE AS THINGS PROGRESS.
PREVIOUS DISCUSSION...
COLD FRONT HAS PUSHED SOUTH THROUGH THE MIDCOAST AND IS NOW
LOCATED FROM WISCASSET TO LEWISTON BEFORE GETTING HUNG UP IN THE
HILL COUNTRY NEAR RUMFORD. TEMPERATURES BEHIND THE FRONT HAVE BEEN
FALLING INTO THE MID 20S AS NOTED OVER THE PAST FEW HOURS AT
BANGOR AND WATERVILLE. THIS FRONT MAY PLAY A KEY ROLE IN
DETERMINING PRECIPITATION TYPE ACROSS THE MIDCOAST REGION TONIGHT.
LOW PRESSURE CURRENTLY JUST SOUTHEAST OF PHILADELPHIA WILL TRACK
QUICKLY NORTHEAST ACROSS CAPE COD AND TO NOVA SCOTIA TONIGHT.
LARGE AREA OF PRECIPITATION HAS SPREAD NORTHWARD AHEAD OF THIS
LOW... NOW SPREADING ACROSS ALL OF SOUTHERN NEW ENGLAND AND
PUSHING INTO SOUTHERN NEW HAMPSHIRE. THIS PRECIPITATION WILL
CONTINUE TO SPREAD NORTHEAST ACROSS NEW HAMPSHIRE AND MAINE
OVERNIGHT... BRINGING A QUICK... BUT HEAVY... ROUND OF
PRECIPITATION BEFORE EXITING JUST AFTER MIDNIGHT.
PRECIPITATION TYPE CONTINUES TO BE A COMPLEX PICTURE WITH THIS
STORM... AS TEMPERATURES THROUGH THE LOWEST FEW THOUSAND FEET WILL
BE NEAR FREEZING ACROSS MUCH OF SOUTHERN NEW HAMPSHIRE AND COASTAL
MAINE. NAM AND HRRR MODELS CONTINUE TO SHOW A COLDER SOLUTION...
WITH TEMPERATURES AT OR JUST BELOW FREEZING AS PRECIPITATION FALLS
THIS EVENING. IT IS EXPECTED THAT AS PRECIPITATION BEGINS TO
INTENSIFY... TEMPERATURES WITHIN THE ATMOSPHERIC PROFILE WILL COOL
AND ALLOW A HEAVY WET SNOW TO FALL. LOTS OF MOISTURE AND GOOD
DYNAMICS WITH THIS SYSTEM WILL ALLOW INTENSE PRECIPITATION
RATES... WITH TOTAL QPF TONIGHT RANGING FROM 0.75 TO 1.00 INCH.
SNOW RATIOS WILL BE NEAR 10 TO 1 DUE TO THE LARGE ISOTHERMAL LAYER
IN THE LOW LEVELS ESPECIALLY OVER SOUTHERN AND CENTRAL NEW
HAMPSHIRE EXTENDING TO THE MAINE COAST. NORTH OF THE PREVIOUSLY
MENTIONED COLD FRONT... TEMPERATURES WILL BE A BIT COLDER...
LEADING TO MORE CERTAINTY THAT PRECIPITATION WILL FALL IN THE FORM
OF SNOW AND ALLOW SNOW RATIOS TO BE A BIT HIGHER... POSSIBLY 13 TO
1.
THERE IS A GOOD AMOUNT OF CONFIDENCE THAT A BAND OF 6 TO 10 INCHES
OF SNOW WILL FALL... THOUGH THE TRANSITION TO RAIN NEAR THE COAST
IS STILL THE BIGGEST QUESTION MARK. IT IS POSSIBLE THAT THE
IMMEDIATE COASTLINE MAY SEE ONLY AN INCH OR TWO OF SNOW WHILE
AREAS JUST INLAND COULD SEE 6 TO 10. WITH THE COLDER FORECAST...
THE WINTER STORM WARNINGS HAVE BEEN EXTENDED TO THE COAST FROM
PORTLAND EASTWARD. THIS AREA WAS ALSO HIT HARD BY THE ICE STORM
LAST WEEKEND AND THE TREES ARE LIKELY STILL SUPPORTING A LOAD OF
ICE FROM THIS. WITH THE ADDITIONAL STICKY... WET SNOW EXPECTED...
THIS COULD CAUSE ADDITIONAL POWER OUTAGES EVEN IF THE 6 INCH
WARNING CRITERIA IS NOT MET.
SNOWFALL RATES WILL LIKELY BE QUITE INTENSE THIS EVENING... WITH 1
TO 2 INCHES PER HOUR COMMON AND RATES UP TO 3 INCHES PER HOUR
POSSIBLE. THIS WILL MAKE IT MORE DIFFICULT FOR ROAD CREWS TO KEEP
UP WITH SNOW REMOVAL DURING THE HEAVIEST PERIOD OF SNOW... CAUSING
EVEN GREATER IMPACTS ON TRAVEL. ALL THESE FACTORS WERE CONSIDERED
IN THE PLACING OF WINTER STORM WARNINGS AND WINTER WEATHER ADVISORIES.
FURTHER TO THE NORTH... THERE WILL LIKELY BE A SHARP CUT OFF IN
SNOWFALL AMOUNTS INLAND OF THE HEAVIEST BAND. LOCATIONS NEAR THE
CANADIAN BORDER MAY NOT SEE MUCH SNOW AT ALL... AND NORTHERN COOS
COUNTY HAS BEEN DROPPED FROM THE ADVISORY AS FORECAST SNOWFALL
AMOUNTS IN THIS REGION ARE ONLY 1 TO 2 INCHES. THE NORTHERN ZONES
IN WESTERN MAINE WERE LEFT IN AS THE SOUTHERN PORTION OF THESE
ZONES STILL HAS A THREAT FOR HIGHER TOTALS.
&&
.SHORT TERM /7 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
AS LOW PRESSURE MOVES EAST... A COLD FRONT WILL PUSH SOUTHEAST
ACROSS NEW ENGLAND ON MONDAY. A VERY COLD AIR MASS HAS BEEN
LURKING BEHIND THIS FRONT... AND THIS WILL BE FELT IN FULL FORCE
BY MONDAY AFTERNOON. TEMPERATURES WILL LIKELY BE FALLING THROUGH
THE DAY AS COLD ADVECTION TAKES OVER. WINDS COULD GUST TO 25 MPH
AS COLD ADVECTION ALLOWS GOOD MIXING TO TAKE PLACE.
TEMPERATURES FALL TO NEAR OR BELOW ZERO ACROSS THE ENTIRE FORECAST
AREA MONDAY NIGHT. READINGS AS COLD AS 20 BELOW ARE POSSIBLE TO
THE NORTH OF THE MOUNTAINS WHERE COLD AIR WILL BE EVEN MORE
INTENSE. WIND CHILL ADVISORIES OR WARNINGS MAY BE NEEDED AS WIND
CHILLS COULD REACH 30 BELOW.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
MODELS IN AGREEMENT THROUGH THE PERIOD FOR A COLD WEEK. A WEAK SHORT
WAVE WILL MOVE THROUGH NEW HAMPSHIRE AND MAINE TUESDAY AFTERNOON
WITH ASSOCIATED SNOW SHOWERS AND USHER IN EVEN COLDER AIR. WIND
CHILL ADVISORIES MAY BE NEEDED TUESDAY NIGHT AND WEDNESDAY. HIGH
PRESSURE CRESTS OVERHEAD WEDNESDAY. LATE IN THE DAY CLOUDS STREAM
EAST. LIGHT SNOW DEVELOPS THURSDAY AS LOW PRESSURE DEVELOPS SOUTH
OF LONG ISLAND NEW YORK. GFS AND ECMWF SIMILAR IN THE TRACK AND
LINGER SNOW INTO FRIDAY. SEVERAL INCHES OF SNOW POSSIBLE WITH THIS
SYSTEM. ANOTHER ARCTIC SHOT OF AIR ARRIVES FRIDAY AFTERNOON AND
SATURDAY. A WARM FRONT WILL MOVE NORTH SUNDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH THURSDAY NIGHT/...VARIABLE CONDITIONS BUT
MOSTLY LIFR THIS EVE...IMPROVE FROM SW TO NE AROUND MIDNIGHT AS
PRCP COMES TO AN END FAIRLY QUICKLY FROM THIS FAST MOVING SYSTEM.
PRCP TYPE WILL BE PROBLEMATIC WITH MIXED WINTRY PRCP EXPECTED
ALONG WITH PRCP CHANGING FROM RAIN OR MIXED TO MIXED OR SNOW
BEFORE ENDING. IMPROVING TO VFR EXCEPT MVFR N/MT ZONES LATER TNGT
AND MONDAY. GUSTY NW WINDS PSBL MONDAY. VFR MONDAY NGT.
LONG TERM...POSSIBLE MVFR IN SNOW SHOWERS TUESDAY AND WEDNESDAY.
IFR MOVES IN THURSDAY AFTERNOON AND MOVES OUT FRIDAY. VFR
SATURDAY AND SUNDAY.
&&
.MARINE...
SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...UPDATED TO INPUT
LATEST OBSERVED DATA. WILL CONT HEADLINES...INCREASED WINDS PER
LATEST BUOY REPORTS. WINDS PICKING UP AS LOW HAS INTENSIFIED MORE
THAN WHAT MODELS HAD PREDICTED.
PREVIOUS DISCUSSION...
LOW PRESSURE MOVING FROM CAPE COD TO NOVA SCOTIA WILL BRING A
BRIEF PERIOD OF NORTHEAST WINDS WHICH COULD GUST TO GALE FORCE.
WINDS SHIFT TO NORTHWEST BY MORNING. A COLD FRONT PUSHING THROUGH
THE GULF OF MAINE ON MONDAY WILL BRING STRONG COLD ADVECTION AND
THE POTENTIAL FOR MORE GALE FORCE GUSTS THROUGH MONDAY EVENING.
LONG TERM...SMALL CRAFT WINDS TUESDAY AND WEDNESDAY. GALE FORCE
WINDS POSSIBLE THURSDAY AFTERNOON INTO SATURDAY MORNING.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MEZ013-014-
020>022-026>028.
WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR MEZ008-009.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EST MONDAY FOR ANZ151-153.
GALE WARNING UNTIL 9 PM EST MONDAY FOR ANZ150-152-154.
&&
$$
ES
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1252 AM EST MON DEC 30 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 424 PM EST SUN DEC 29 2013
ARCTIC AIR AND CONTINUED LAKE EFFECT OFF LAKE SUPERIOR WILL BE THE
MAIN CONCERNS FOR THE SHORT TERM PERIOD.
THE SURFACE LOW THAT BROUGHT THE SURGE OF COLD AIR CONTINUES TO
SLIDE EAST OF THE AREA...WHILE HIGH PRESSURE HAS BUILT INTO THE
NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY. THE EXITING LOW HAS
LEFT A SURFACE TROUGH OVER EASTERN LAKE SUPERIOR. ALOFT...AREA IS
UNDER AN UPPER TROUGH THAT COVERS MUCH OF THE EASTERN CONUS AND HAS
LED TO ARCTIC AIR SPILLING SOUTHEAST OVER THE UPPER GREAT LAKES LAST
NIGHT. THIS COLD AIR HAS BEEN PRODUCING LAKE EFFECT SNOW SHOWERS IN
THE NORTH-NORTHWEST WIND LOCATIONS TODAY. LATEST RADAR/SATELLITE
DATA INDICATES THE BEST BANDS OVER FAR EASTERN MARQUETTE COUNTY
AND ALGER COUNTIES...WHERE RADAR RETURNS HAVE BEEN REACHING
7KFT. HAVE STARTED SEEING THE LOW LEVEL WINDS BACKING ASSOCIATED
WITH THE HIGH PRESSURE RIDGE OVER THE LAST FEW HOURS...ESPECIALLY
OVER THE WESTERN LAKE...AND THAT HAS STARTED TO PUSH THE BANDS OVER
MARQUETTE COUNTY EASTWARD. WITH AT LEAST HALF OF THE CLOUD BEING
ABOVE THE DGZ BASED ON RAP INITIAL SOUNDINGS...CALLS TO SPOTTERS
HAS INDICATED JUST A COUPLE INCHES OF ADDITIONAL SNOW
ACCUMULATION TODAY. THE BIGGEST ISSUE HAS BEEN THE SMALL FLAKES
REDUCING VISIBILITIES...ALONG WITH GUSTY WINDS TO 30-35MPH EAST
OF MARQUETTE...AND CAUSING BRIEF WHITEOUTS ALONG M-28 IN ALGER
COUNTY. A CALL TO THE ALGER COUNTY SHERIFF INDICATED SEVERAL
ACCIDENTS ON THAT STRETCH...WITH THEM ENCOURAGING TRAVEL ALONG
M-94 INSTEAD.
WITH THE COLD AIR IN PLACE AND SOME LOW LEVEL MOISTURE...EXPECT THE
LAKE EFFECT TO CONTINUE THROUGH THE SHORT TERM PERIOD. THE
LOCATION OF THE SNOW WILL BE DETERMINED BY BOUNDARY LAYER WINDS.
SINCE THE HIGH OVER SOUTHEAST SOUTH DAKOTA WILL DRIFT TO THE
SOUTHEAST THROUGH THE NIGHT...IT WILL PUSH A RIDGE INTO THE
SOUTHWEST HALF OF UPPER MICHIGAN. THIS RIDGE WILL DO TWO
THINGS...BACK THE WINDS TO MORE OF A WEST-NORTHWEST DIRECTION AND
CONTINUE TO PROVIDE DRY AIR AND SUBSIDENCE ABOVE 850MB. THOSE
BACKING WINDS WILL ALSO BE AIDED BY A SHORTWAVE DEPARTING THE
CANADIAN ROCKIES AND MOVING INTO THE NORTHERN PLAINS ON
MONDAY. THIS WILL LEAD TO WINDS TRANSITIONING FROM THE
NORTH-NORTHWEST LATE THIS AFTERNOON TO THE NORTHWEST THIS EVENING
AND EVENTUALLY NEARLY WESTERLY BY 18Z MONDAY. THEREFORE...WOULD
EXPECT THE PURE LAKE EFFECT BANDS (NO SHORTWAVE HELP) TO FOLLOW
SUIT. 850MB TEMPS WILL REMAIN FAIRLY STEADY THROUGH MONDAY AND
AROUND -23C...LEADING TO DELTA-T VALUES AROUND THE MID 20S. BUT
THIS COLD AIR WILL LEAD TO MUCH OF THE CLOUD BEING AT THE HIGH END
OF THE DGZ OR ABOVE IT...SO WOULD EXPECT SNOW RATIOS TO BE ON THE
LOWER END FOR LAKE EFFECT AND IN MOST SITUATIONS BELOW 20 TO 1. IN
THE STRONGEST BANDS OVER THE EAST AND THE BETTER LAKE
MODIFICATION...DID KEEP SOME LOW 20S IN THE FORECAST. AS SEEN ON
SATELLITE NEAR IRONWOOD THIS AFTERNOON...THE STRONGEST BANDS
WILL BE ON THE SOUTHWEST EDGE OF THE LES DUE TO THE ENHANCED
CONVERGENCE FROM THE BACKING WINDS. ALTHOUGH THIS WILL STRENGTHEN
THE BANDS...THINK THE CONSISTENT BACKING FLOW (ALONG WITH THE LOWER
RATIOS) WILL BE ENOUGH TO KEEP AMOUNTS GENERALLY LIGHT. HAVE KEPT
AMOUNTS FAIRLY SIMILAR TO WHAT WAS SEEN DURING THE DAY TODAY IN THE
LES LOCATIONS (1-2.5IN)...BUT DO HAVE SLIGHTLY HIGHER AMOUNTS
(APPROACHING 4) OVER THE EAST WITH THE SLOWER BACKING TREND. THE
LONGER FETCH WITH THE WEST TO WEST-SOUTHWEST WINDS OVER WESTERN
LAKE SUPERIOR COULD LEAD TO AN INCREASE IN INTENSITY OF THE MAIN
LAKE EFFECT BAND OVER THE KEWEENAW PENINSULA (NORTH OF HOUGHTON).
LAKE INDUCED EQUILIBRIUM LEVELS STILL AROUND 7KFT AND MUCH OF THE
CLOUDS IS AT HIGH END OF DGZ OR ABOVE SO WON/T GO TOO HIGH ON
AMOUNTS IN THE LATE MORNING AND INTO THE AFTERNOON...BUT COULD NEAR
LOW END ADVISORY AMOUNTS.
AS FOR SNOW HEADLINES...CANCELLED BARAGA AND SOUTHERN HOUGHTON
EARLY AND WILL ALLOW THE REST OF THE WESTERN AREAS EXPIRE AT 00Z AS
WINDS WILL DIMINISH AND JUST LIGHT SNOW WILL REMAIN. OVER THE
EAST...HAVE KEPT THEM AS IS WITH THE BAD CONDITIONS REPORTED ALONG
M-28 IN ALGER COUNTY...ALTHOUGH MOST LOCATIONS TONIGHT WILL
STRUGGLE TO REACH THE 4 INCH IN 12HR AMOUNTS DUE TO THE SMALLER
FLAKES.
AS FOR THE WIND CHILL HEADLINES...CLOUDS WILL DETERMINE THE LOWS
TONIGHT. UNFORTUNATELY IT COMES DOWN TO THE DIMINISHING LAKE
EFFECT CLOUDS OVER THE WEST AND THEN HIGH CLOUDS STREAMING IN LATE
TONIGHT AHEAD OF THE NEXT WAVE IN THE UPPER TROUGH SLIDING SOUTHEAST
THROUGH THE NORTHERN PLAINS. 12Z GFS/ECMWF ARE THE MOST AGGRESSIVE
WITH THESE HIGH CLOUD...COVERING THE WESTERN HALF OF THE CWA BY
12Z. WITH THE COLD AIR IN PLACE...THINK THAT TEMPS WILL COOL
FAIRLY QUICKLY IN AREAS THAT SKIES CLEAR. THE REGIONAL
GEM...WHICH TRADITIONALLY DOES WELL IN THESE CASES ONLY HAS LOWS
IN THE LOW TEENS BELOW ZERO ALONG THE WISCONSIN BORDER AND SINGLE
DIGITS ELSEWHERE. THIS PROVIDES SOME CONCERN TO THE GOING FORECAST
AND TWEAKED VALUES SLIGHTLY HIGHER. ON THE OTHER SIDE...18Z HRRR/RAP
FORECASTS HAVE LOWS AROUND -20 TO -23 TONIGHT...BUT IN MOST
SITUATIONS THEY ARE TOO LOW. EVEN WITH THE SLIGHT TWEAKS...WIND
CHILL ADVISORY LOOKS GOOD FOR AREAS NEAR THE WISCONSIN BORDER AND
HAVE LEFT IT AS IS. A LITTLE CONCERNED ON LAKE CLOUDS LINGERING
OVER MARQUETTE/BARAGA...BUT LOCATIONS WELL INLAND SHOULD CLEAR OUT
LATE AND ALLOW FOR TEMPS TO FALL. FINALLY...MAY NEED TO MONITOR
MENOMINEE COUNTY...AS GOING FORECAST HAS WIND CHILLS NEARING -25
OVER THE WESTERN REACHES OF THE COUNTY.
THE PREVIOUSLY MENTIONED MID/HIGH CLOUDS WILL MOVE ACROSS THE REST
OF THE CWA DURING THE DAY ON MONDAY AND LEAD TO A FILTERED SUNSHINE
AWAY FROM THE LAKE EFFECT. THERE COULD EVEN BE A FEW SNOW SHOWERS
NEAR IRONWOOD LATE MONDAY AFTERNOON ON THE NORTH EDGE OF THE WAVE
MOVING INTO WISCONSIN ON MONDAY EVENING. HIGHS ON MONDAY WILL BE
15-20 DEGREES BELOW NORMAL AND IN THE SINGLE DIGITS ABOVE ZERO FOR
MOST LOCATIONS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 425 PM EST SUN DEC 29 2013
BIGGEST CONCERNS IN THE EXTENDED FOCUS ON THE POTENTIAL FOR HEAVY
LAKE EFFECT SNOW OVER THE NE CWA MON NIGHT INTO TUESDAY AND ALSO
ADVISORY LEVEL WIND CHILLS FOR SOME AREAS INTO MIDWEEK.
MON NIGHT INTO TUE...AS THE POLAR VORTEX SLOWLY SHIFTS SE FROM
HUDSON BAY...THE MODELS SUGGEST A SHORTWAVE TROUGH WILL MOVE THROUGH
THE UPPER MS VALLEY TOWARD THE UPPER GREAT LAKES. THE BEST ISENTROPIC
LIFT NEAR THE 850 MB FRONT AND POTENTIAL FOR WIDESPREAD LIGHT SNOW
IS EXPECTED TO REMAIN TO THE SOUTH OF UPPER MI. AS THE LOW LEVEL
WINDS BACK W OR WSW AHEAD OF THE SHRTWV ON MONDAY...THE LES OVER THE
NE CWA WILL GRADUALLY LIFT TO THE NORTH AND POSSIBLY MOVE OFFSHORE
BY LATE IN THE DAY. VEERING WINDS IN THE WAKE OF THE SHRTWV WILL
PUSH THE LES BACK INTO AREAS FAVORED BY NW FLOW BY LATE EVENING.
LAKE INDUCED TROUGHING IS EXPECTED TO FOCUS THE STRONGEST LOW LEVEL
CONV BACK INTO THE NE PORTION OF THE CWA FROM P53 EASTWARD. NAM FCST
SOUNDINGS ALSO INDICATE THAT THE DGZ WILL BE MORE FAVORABLY PLACED
IN THE CONVECTIVE LAYER TO BOOST SLR VALUES AND OVERALL SNOWFALL
POTENTIAL. USING A BLEND OF THE NAM AND LOCAL WRF-ARW QPF WITH
LIKELY CONSERVATIVE SLR VALUES AROUND 20/1...CAME UP WITH TOTAL
SNOWFALL ACCUMULATION EXCEEDING A FOOT OVER ERN ALGER AND NRN LUCE
COUNTIES FOR THE MON NIGHT THROUGH TUE TIME FRAME. THUS...HAVE
DECIDED TO ISSUE A LAKE EFFECT SNOW WATCH FOR ALGER AND LUCE
COUNTIES OVER THIS TIME FRAME. NRN SCHOOLCRAFT WILL LIKELY SEE
PERIODS OF HEAVY LES AS WELL...BUT LOW-LVL CONVERGENCE WILL NOT BE
AS PERSISTENT THERE SO WILL KEEP THEM OUT OF THE WATCH...BUT FEEL
PRETTY CERTAIN THEY WILL EVENTUALLY NEED AN LES ADVISORY.
EVEN THOUGH TEMPS MAY NOT BE AS COLD EARLY TUE...SLIGHTLY STRONGER
WINDS IN THE WAKE OF THE SHORTWAVE WILL AGAIN PUSH WIND CHILLS INTO
THE -25 TO -35 ADVISORY RANGE OVER THE WEST.
WED INTO THU...THE NEXT SIGNIFICANT SHORTWAVE TROUGH IS EXPECTED TO
REMAIN WELL TO THE SOUTH BRINGING SNOW TO MAINLY IA/NRN IL/SRN WI
AND THE SOUTHERN GREAT LAKES. GREAT LAKES AGGREGATE TROUGHING WILL
INFLUENCE GENERALLY LIGHT LOW LEVEL WIND FIELDS AND THE RESULTING LES
INTO UPPER MI AS 850 MB TEMPS REMAIN IN THE -22C TO -26C RANGE. IT
APPEARS NOW THE MAIN FOCUS FOR LES ACCUMULATIONS MAY BE OVER THE
WEST AND NCNTRL PORTIONS OF THE CWA AS A N-NE FLOW IS EXPECTED TO
DEVELOP WED NIGHT INTO THU ON THE BACKSIDE OF SFC LOW PASSING SOUTH
AND THEN EAST OF THE REGION. WITH MODEL SNDGS SHOWING COMPRESSION OF
THE DGZ WITHIN THE LOWEST 2KFT OF THE ATMOSPHERE ALONG WITH
INVERSION HGTS AROUND 5 KFT...THE EXPECTED SMALLER FLAKE SIZE SHOULD
GENERALLY KEEP ACCUMULATION LIGHT FOR THE MOST PART.
FRI-SUN...MODELS WERE IN GENERAL AGREEMENT WITH TREND TOWARD A LESS
AMPLIFIED PATTERN. AS SFC HIGH PRESSURE SLIDES EAST LATE IN THE
WEEK...THE ECMWF AND GFS DEVELOP AREA OF LIGHT SNOW IN REGION OF
WAA/ISENTROPIC ASCENT AHEAD OF A SHRTWV MOVING THROUGH NW ONTARIO.
THIS SNOW LOOKS TO SPREAD INTO UPPER MI LATE FRI INTO SAT MORNING
WITH ANOTHER BAND OF SYNOPTIC SNOW ALONG COLD FRONTAL PASSAGE SAT
AFTERNOON/SAT NIGHT. EXPECT LES TO DEVELOP LATE SATURDAY NIGHT INTO
SUNDAY WITH INCREASING CAA IN NNW FLOW IN THE WAKE OF THE COLD
FRONT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1247 AM EST MON DEC 30 2013
IWD...AS THE LLVL FLOW BACKS SLOWLY TOWARD THE WSW THRU THE NGT...
EXPECT LINGERING -SHSN/CLDS TO SHIFT TO THE N...WITH A TREND TOWARD
PREDOMINANT VFR WX. ALTHOUGH SOME LGT SN IN ADVANCE OF ANOTHER
DISTURBANCE MAY ARRIVE LATE MON AFTN...CONDITIONS ARE LIKELY TO
REMAIN VFR AS THIS SYS WL BE MSTR DEPRIVED AND THE SHARPER DYNAMICS
WL REMAIN TO THE S. A WSHFT TOWARD THE WNW IN ITS WAKE MAY BRING A
RETURN OF LK EFFECT -SHSN AND MVFR CONDITIONS DURING THE EVNG.
CMX...WITH A SLOWLY BACKING NW TO W FLOW OF ARCTIC AIR...EXPECT LK
EFFECT -SHSN AND PREDOMINANT IFR VSBYS TO PERSIST THRU THE FCST
PERIOD. SHARPENING LLVL CNVGC COINCIDENT WITH THE PASSAGE OF A
STRONGER DISTURBANCE/ACCOMPANYING LO PRES TROF PASSAGE MAY BRING A
PERIOD OF HEAVIER SHSN/LIFR CONDITIONS THIS EVNG.
SAW...WITH A DOWNSLOPE W WIND FLOW OF DRY ARCTIC AIR...EXPECT VFR
CONDITIONS TO DOMINATE THIS LOCATION THE ENTIRE FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 424 PM EST SUN DEC 29 2013
NORTHWESTERLY WINDS OF 15 TO 25 KNOTS WILL CONTINUE INTO THIS
EVENING BEFORE BACKING TO THE WEST-NORTHWEST LATE TONIGHT INTO
MONDAY. WINDS WILL WEAKEN SLIGHTLY AS THIS OCCURS AND SLOWLY
DIMINISH THE POTENTIAL FOR FREEZING SPRAY OVER THE LAKE BY MONDAY
AFTERNOON. AS THE LINGERING SURFACE TROUGH OVER EASTERN LAKE
SUPERIOR STRENGTHENS ON MONDAY NIGHT AND SHIFTS EAST ON
TUESDAY...NORTHWESTERLY WINDS WILL INCREASE WITH SOME GUSTS TO 30KTS
OVER THE EASTERN LAKE TUESDAY AFTERNOON AND EVENING. THIS WILL ALSO
BRING AN INCREASED OPPORTUNITY FOR HEAVY FREEZING SPRAY THROUGH
TUESDAY NIGHT OVER THE EASTERN HALF OF LAKE SUPERIOR. ALTHOUGH
THERE STILL WILL BE A LINGERING TROUGH OVER EASTERN LAKE SUPERIOR
INTO WEDNESDAY...HIGH PRESSURE BUILDING OVER THE UPPER MISSISSIPPI
VALLEY WILL LEAD TO LIGHTER NORTHWESTERLY WINDS FOR WEDNESDAY AND
THURSDAY...BRINGING AN END TO THE POTENTIAL FOR HEAVY FREEZING
SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY UNTIL 10 AM EST /9 AM CST/ THIS MORNING FOR
MIZ002-009>011-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ085.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ006-007.
LAKE EFFECT SNOW WATCH FROM THIS EVENING THROUGH TUESDAY EVENING
FOR MIZ006-007.
WIND CHILL ADVISORY FROM 4 AM TO 10 AM EST THIS MORNING FOR
MIZ004-005.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR
LSZ248>251-264-267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR LSZ266.
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
LSZ265.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST /MIDNIGHT CST/ EARLY
THIS MORNING FOR LSZ240>245-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...VOSS
AVIATION...KC
MARINE...SRF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
137 AM EST MON DEC 30 2013
.SYNOPSIS...
SURFACE LOW PRESSURE WILL MOVE INTO NEW ENGLAND TONIGHT AND INTO
EASTERN CANADA BY MONDAY...WHILE A SHARP ARCTIC COLD FRONT PUSHES
ACROSS THE NORTH COUNTRY ON MONDAY MORNING. A MIX OF RAIN AND SNOW
WILL GRADUALLY END TONIGHT WITH SOME MODERATE SNOW ACCUMULATION
LIKELY ACROSS THE HIGHER TERRAIN OF CENTRAL AND SOUTHERN VERMONT.
ADDITIONAL SNOW SHOWERS WILL BE POSSIBLE ASSOCIATED WITH THE
ARCTIC BOUNDARY ON MONDAY MORNING...WITH A FLASH FREEZE
LIKELY...CREATING A HAZARDOUS COMMUTE.
&&
.NEAR TERM /UNTIL 10 AM THIS MORNING/...
AS OF 1221 AM EST MONDAY...CANCELLED ALL ADVISORIES/WARNINGS AS
STEADY PRECIPITATION HAS RAPIDLY EXITED THE REGION. SNOW/ICE
REPORTS ARE AVAILABLE IN PUBLIC INFORMATION STATEMENT. SOME FOG
HAS DEVELOPED IN THE WAKE OF THE DEPARTING PRECIP...AND THIS WILL
CONTINUE UNTIL SCOURED OUT BY THE PASSAGE OF THE ARCTIC FRONT
LATER TONIGHT. STILL LOOKING AT A BRIEF PERIOD OF SNOW SHOWERS AS
THE FRONT CROSSES THE REGION...WITH PERHAPS A SMALL WINDOW FOR
SOME UPSLOPE ENHANCEMENT IN THE MOUNTAINS...BUT THE ATMOSPHERE
DRIES OUT QUICKLY MONDAY MORNING...SO ONLY A DUSTING-2" EXPECTED
AT MOST. WILL SEE TEMPERATURES DROP FROM THE LOW 30S THROUGH THE
20S AND INTO THE TEENS QUITE RAPIDLY MONDAY MORNING SO A QUICK
FREEZE-UP OF ANY RESIDUAL WATER OR SLUSH IS POSSIBLE.
PREVIOUS DISCUSSION FROM 922 PM SUNDAY...
QUICK HITTING WINTER STORM NOW WINDING DOWN ACROSS THE REGION AS
STRENGTHENING LOW PRESSURE CENTERED NEAR NANTUCKET MOVES
NORTHEASTWARD OVER CAPE COD AND TO A POSITION OVER NOVA SCOTIA BY
MONDAY MORNING. HEAVIEST PRECIPITATION NOW OVER SOUTHEASTERN
VERMONT WITH LIGHT-MODERATE PRECIP STILL BACK INTO THE CHAMPLAIN
VALLEY. BACK EDGE HAS CLEARED PLATTSBURGH AND WILL PUSH THROUGH
BURLINGTON WITHIN THE HOUR. PRECIP WILL TAPER OFF FAIRLY QUICKLY
OVER THE NEXT 2-3 HOURS FOR ENTIRE REGION. MOST PRECIP HAS FALLEN
AS SNOW WHERE IT HAS BEEN HEAVY DUE TO DYNAMIC COOLING...AT RATES
OF 1-3 INCHES PER HOUR IN SE VT. REPORTS ACROSS SOUTHERN AND
EASTERN VERMONT GENERALLY RANGE BETWEEN 3 AND 9 INCHES SO FAR.
HOWEVER...WHERE IT HAS REMAINED LIGHTER ALLOWING THE WARM BOUNDARY
LAYER TO HANG ON...IT HAS BEEN IN THE FORM OF A RAIN/SNOW MIX. LOW
LEVEL COLD AIR HAD ALSO SUNK SOUTHWARD INTO THE CHAMPLAIN
VALLEY...DELIVERING LIGHT FREEZING RAIN/SLEET (FROM BTV NORTHWARD)
WITH WARM LAYER STILL REMAINING AT AROUND 925-MB. LOCAL BTV WRF
AND HRRR MODELS HANDLING THERMAL PROFILES AND DEPICTION OF
PRECIPITATION THE BEST SO HAVE LEANED HEAVILY TOWARDS THEM FOR THE
REST OF TONIGHT.
ARCTIC FRONT THEN BRINGS AN ADDITIONAL CHANCE OF SNOW SHOWERS
TOWARDS MORNING...WITH RAPIDLY FALLING TEMPERATURES AND THREAT OF
FREEZING WATER/SLUSH ON ROADWAYS.
TOTALS GENERALLY 4-8" LOCALLY 10" IN ORANGE/WINDSOR/EASTERN RUTLAND
COUNTIES...DUSTING-4" HIGHLY DEPENDENT ON PRECIP INTENSITY AND
ELEVATION ACROSS MUCH OF THE REST OF VERMONT OUTSIDE OF THE
CHAMPLAIN VALLEY...AND A DUSTING-2" ELSEWHERE. ICE ACCUMULATIONS
IN THE CPV GENERALLY A FEW HUNDRETHS...ENOUGH TO CAUSE HAZARDOUS
TRAVEL AND ACCIDENTS.
&&
.SHORT TERM /10 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 322 PM EST SUNDAY...WITH UPSLOPE SNOW SHOWERS ACROSS THE
HIGHER TERRAIN EFFECTIVELY COMING TO AN END EARLY MONDAY
NIGHT...THE FOCUS THEN SHIFTS TO A PERIOD OF VERY COLD
TEMPERATURES BEGINNING MONDAY NIGHT AND CONTINUING INTO THE FIRST
FEW DAYS OF 2014.
ARCTIC COLD FRONT MOVES ACROSS THE REST OF THE NORTH COUNTRY EARLY
MONDAY NIGHT ALLOWING FOR 850 TEMPS TO FALL TO AROUND -16 TO -18C.
WITH DEEP-LAYER DRYING TAKING PLACE AS HIGH PRESSURE BUILDS INTO THE
REGION OVERNIGHT TEMPERATURES MONDAY WILL BE QUITE COLD. ASIDE FROM
SOUTHERN VERMONT...MOST LOCATIONS WILL SEE LOWS THAT ARE BELOW ZERO
EVEN IN THE CHAMPLAIN VALLEY. I THINK THE COLDEST SPOT MONDAY NIGHT
WILL BE IN THE NORTHEAST KINGDOM AS THAT AREA IS FURTHEST REMOVED
FROM MID-LEVEL WARM ADVECTION CLOUDINESS WHICH IS PROJECTED TO SPILL
INTO NORTHERN NEW YORK LATE MONDAY NIGHT.
INCREASING CLOUDS THEN SPREAD ACROSS THE REST OF THE NORTH COUNTRY
TUESDAY AHEAD OF A MOISTURE-STARVED CLIPPER SYSTEM. DESPITE THE
FACT THAT MOISTURE WILL BE LIMITED WITH THE CLIPPER...ACCOMPANYING
ISENTROPIC LIFT AND RATHER HIGH SNOW/LIQUID RATIOS (15-20:1) DUE TO
COLD AIRMASS IN PLACE SHOULD ALLOW FOR AT LEAST A MODEST POWDERY
SNOW ACCUMULATION OF 1-3". THE ASSOCIATED COLD FRONT WILL THEN
USHER IN ANOTHER SHOT OF EVEN COLDER AIR TUESDAY NIGHT. NORTHWEST
WINDS WILL ALSO BE IN THE 15 TO 20 MPH RANGE WITH GUSTS TO 30 MPH
AS WELL FROM STRONGER MIXING. IT WOULDN`T BE SURPRISING IF SOME
LOCALES IN THE NORTHEAST KINGDOM AND NORTHERN NEW YORK HIT WIND
CHILL ADVISORY CRITERIA...WHICH WILL NEED TO BE MONITORED WITH LATER
SHIFTS. LOWS TUESDAY NIGHT MAY BE A FEW DEGREES WARMER THAN MONDAY
NIGHT (RANGING FROM THE LOWER SINGLE DIGITS TO 10 BELOW ZERO)...BUT
IT CERTAINLY WON`T FEEL THAT WAY GIVEN THE WINDS.
A RIDGE OF ARCTIC HIGH PRESSURE WILL EXTEND ACROSS THE NORTHERN
HALF OF THE NORTH COUNTRY ON WEDNESDAY...SEPERATING A DEVELOPING
EAST-WEST WARM FRONTAL BOUNDARY EXTENDING FROM A DISTURBANCE IN THE
GREAT LAKES. THE NORTH COUNTRY REMAINS ON THE COLD SIDE OF THIS
BOUNDARY THROUGHOUT WEDNESDAY...AND HAVE SHOWN INCREASING POPS FROM
SOUTH TO NORTH WEDNESDAY INTO WEDNESDAY NIGHT. I DO THINK THAT
THERE WILL PROBABLY BE A SHARP NORTH-SOUTH GRADIENT IN
PRECIPITATION GIVEN THE INFLUENCE OF THE ARCTIC HIGH WITH THE
HIGHEST POPS (CHANCE) CONFINED TO CENTRAL AND SOUTHERN VERMONT.
TEMPERATURES REMAIN COLD WITH HIGHS IN THE SINGLE DIGITS TO LOW
TEENS AND LOWS 0 TO 15 BELOW (COLDEST NORTH).
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 322 PM EST SUNDAY...CONSISTENCY IS GOOD AMONGST GLOBAL
MODELS INTO THURSDAY WITH SOME DIFFERENCES IN POSITION AND TRACK
OF A POTENTIAL COASTAL SYSTEM APPROACHING SOUTHERN NEW ENGLAND AND
ADJACENT COASTAL WATERS. THEME OF COLD TEMPERATURES CONTINUES
EARLY IN THIS PERIOD WITH AN INCREASING TREND TOWARD MORE ACTIVE
WEATHER FOR LATE IN THE WEEK.
LIGHT SNOWS SHOULD BE ONGOING TO OPEN THE EXTENDED WITH THE NORTH
COUNTRY ON THE NORTHERN SIDE OF A QUASI-STATIONARY BOUNDARY OVER
CENTRAL/SOUTHERN NEW ENGLAND. MEANWHILE...A MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE LOWER OHIO VALLEY WILL HELP TO ENERGIZE A
DEVELOPING COASTAL LOW NEAR THE CHESAPEAKE BAY AREA EARLY THURSDAY
MORNING. THE GFS TAKES THE DEVELOPING COASTAL NEAR OR JUST
SOUTHEAST OF THE 40N/70W BENCHMARK...WHILE THE ECMWF IS STRONGER
AND DECIDEDLY MORE INSIDE THE BENCHMARK. THOUGH BOTH MODELS SHOW A
DIFFERING CENTER TRACK...THE SOLUTIONS ARE AT LEAST CONSISTENT WITH
THEIR PRIOR COUPLE OF RUNS. BOTH GFS AND ECMWF SHOW A GOOD EASTERN
UPSLOPE PRECIPITATION ENHANCEMENT SIGNATURE AND HAVE SHOWN THE
HIGHEST POPS (LOW LIKELY) TOWARD THE EAST-FACING SLOPE AREAS FOR
THURSDAY NIGHT. LINGERING SNOWS CONTINUE INTO EARLY FRIDAY BEFORE
TAPERING THEREAFTER. IT`S STILL A LITTLE EARLY TO PROJECT SNOW
AMOUNTS WITH MORE SPECIFIC DETAILS WHICH STILL BE IRONED OUT...BUT
IT`S PROBABLY FAIR TO SAY THAT THERE WOULD BE SOME POTENTIAL IMPACT
FROM THIS COASTAL FOR THE NORTH COUNTRY. HIGHS THURSDAY AND FRIDAY
WILL STAY IN THE SINGLE DIGITS.
A LARGE-AMPLITUDE UPPER-LEVEL TROUGH THEN LINGERS OVER THE NORTH
COUNTRY FRIDAY NIGHT INTO SATURDAY WHICH WILL MAINTAIN CONTINUED
BITTER COLD. 850 TEMPS OF -24 TO -26C ALONG WITH AT LEAST PARTLY
CLOUDY SKIES SHOULD RESULT IN LOWS FRIDAY NIGHT AROUND -8 TO -16
BELOW. SOME INDICATION BY LATER IN THE WEEKEND THAT THE VERY COLD
TEMPERATURES FINALLY BEGIN TO MODERATE.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
THROUGH 06Z TUESDAY...THE LOW PRESSURE AREA THAT BROUGHT
RAIN...FREEZING RAIN AND SNOW TO THE REGION SUNDAY NIGHT IS NOW
OVER WESTERN NOVA SCOTIA AT 06Z MONDAY. PRECIPITATION ACROSS THE REGION
HAS ENDED FOR THE MOST PART...WITH MAINLY FOG/MIST AND POCKETS OF
FREEZING DRIZZLE AT 06Z MONDAY. IFR/MVFR CEILINGS/VISIBILITIES
WILL IMPROVE TO VFR BY 18Z MONDAY WITH CLEARING SKIES DEVELOPING
ACROSS THE REGION AS A SURFACE RIDGE OF HIGH PRESSURE BUILDS
SOUTHEAST FROM CANADA. THIS HIGH PRESSURE AREA WILL BE CENTERED
OVER THE REGION BY 06Z TUESDAY.
OUTLOOK 06Z TUESDAY THROUGH FRIDAY...
06Z TUESDAY-12Z TUESDAY...VFR WITH LIGHT WINDS WITH ARCTIC AIR.
TUE...BECMG IFR IN PM LIGHT SNOW WITH LOW PRESSURE CLIPPER SYSTEM.
WED...MAINLY VFR UNDER ARCTIC HIGH PRESSURE.
THU-FRI...BECMG IFR IN SNOW WITH LOW PRESSURE OFF THE COAST.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...MUCCILLI
SHORT TERM...LOCONTO
LONG TERM...LOCONTO
AVIATION...WGH/SISSON
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1229 AM EST MON DEC 30 2013
.SYNOPSIS...
SURFACE LOW PRESSURE WILL MOVE INTO NEW ENGLAND TONIGHT AND INTO
EASTERN CANADA BY MONDAY...WHILE A SHARP ARCTIC COLD FRONT PUSHES
ACROSS THE NORTH COUNTRY ON MONDAY MORNING. A MIX OF RAIN AND SNOW
WILL GRADUALLY END TONIGHT WITH SOME MODERATE SNOW ACCUMULATION
LIKELY ACROSS THE HIGHER TERRAIN OF CENTRAL AND SOUTHERN VERMONT.
ADDITIONAL SNOW SHOWERS WILL BE POSSIBLE ASSOCIATED WITH THE
ARCTIC BOUNDARY ON MONDAY MORNING...WITH A FLASH FREEZE
LIKELY...CREATING A HAZARDOUS COMMUTE.
&&
.NEAR TERM /UNTIL 10 AM THIS MORNING/...
AS OF 1221 AM EST MONDAY...CANCELLED ALL ADVISORIES/WARNINGS AS
STEADY PRECIPITATION HAS RAPIDLY EXITED THE REGION. SNOW/ICE
REPORTS ARE AVAILABLE IN PUBLIC INFORMATION STATEMENT. SOME FOG
HAS DEVELOPED IN THE WAKE OF THE DEPARTING PRECIP...AND THIS WILL
CONTINUE UNTIL SCOURED OUT BY THE PASSAGE OF THE ARCTIC FRONT
LATER TONIGHT. STILL LOOKING AT A BRIEF PERIOD OF SNOW SHOWERS AS
THE FRONT CROSSES THE REGION...WITH PERHAPS A SMALL WINDOW FOR
SOME UPSLOPE ENHANCEMENT IN THE MOUNTAINS...BUT THE ATMOSPHERE
DRIES OUT QUICKLY MONDAY MORNING...SO ONLY A DUSTING-2" EXPECTED
AT MOST. WILL SEE TEMPERATURES DROP FROM THE LOW 30S THROUGH THE
20S AND INTO THE TEENS QUITE RAPIDLY MONDAY MORNING SO A QUICK
FREEZE-UP OF ANY RESIDUAL WATER OR SLUSH IS POSSIBLE.
PREVIOUS DISCUSSION FROM 922 PM SUNDAY...
QUICK HITTING WINTER STORM NOW WINDING DOWN ACROSS THE REGION AS
STRENGTHENING LOW PRESSURE CENTERED NEAR NANTUCKET MOVES
NORTHEASTWARD OVER CAPE COD AND TO A POSITION OVER NOVA SCOTIA BY
MONDAY MORNING. HEAVIEST PRECIPITATION NOW OVER SOUTHEASTERN
VERMONT WITH LIGHT-MODERATE PRECIP STILL BACK INTO THE CHAMPLAIN
VALLEY. BACK EDGE HAS CLEARED PLATTSBURGH AND WILL PUSH THROUGH
BURLINGTON WITHIN THE HOUR. PRECIP WILL TAPER OFF FAIRLY QUICKLY
OVER THE NEXT 2-3 HOURS FOR ENTIRE REGION. MOST PRECIP HAS FALLEN
AS SNOW WHERE IT HAS BEEN HEAVY DUE TO DYNAMIC COOLING...AT RATES
OF 1-3 INCHES PER HOUR IN SE VT. REPORTS ACROSS SOUTHERN AND
EASTERN VERMONT GENERALLY RANGE BETWEEN 3 AND 9 INCHES SO FAR.
HOWEVER...WHERE IT HAS REMAINED LIGHTER ALLOWING THE WARM BOUNDARY
LAYER TO HANG ON...IT HAS BEEN IN THE FORM OF A RAIN/SNOW MIX. LOW
LEVEL COLD AIR HAD ALSO SUNK SOUTHWARD INTO THE CHAMPLAIN
VALLEY...DELIVERING LIGHT FREEZING RAIN/SLEET (FROM BTV NORTHWARD)
WITH WARM LAYER STILL REMAINING AT AROUND 925-MB. LOCAL BTV WRF
AND HRRR MODELS HANDLING THERMAL PROFILES AND DEPICTION OF
PRECIPITATION THE BEST SO HAVE LEANED HEAVILY TOWARDS THEM FOR THE
REST OF TONIGHT.
ARCTIC FRONT THEN BRINGS AN ADDITIONAL CHANCE OF SNOW SHOWERS
TOWARDS MORNING...WITH RAPIDLY FALLING TEMPERATURES AND THREAT OF
FREEZING WATER/SLUSH ON ROADWAYS.
TOTALS GENERALLY 4-8" LOCALLY 10" IN ORANGE/WINDSOR/EASTERN RUTLAND
COUNTIES...DUSTING-4" HIGHLY DEPENDENT ON PRECIP INTENSITY AND
ELEVATION ACROSS MUCH OF THE REST OF VERMONT OUTSIDE OF THE
CHAMPLAIN VALLEY...AND A DUSTING-2" ELSEWHERE. ICE ACCUMULATIONS
IN THE CPV GENERALLY A FEW HUNDRETHS...ENOUGH TO CAUSE HAZARDOUS
TRAVEL AND ACCIDENTS.
&&
.SHORT TERM /10 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 322 PM EST SUNDAY...WITH UPSLOPE SNOW SHOWERS ACROSS THE
HIGHER TERRAIN EFFECTIVELY COMING TO AN END EARLY MONDAY
NIGHT...THE FOCUS THEN SHIFTS TO A PERIOD OF VERY COLD
TEMPERATURES BEGINNING MONDAY NIGHT AND CONTINUING INTO THE FIRST
FEW DAYS OF 2014.
ARCTIC COLD FRONT MOVES ACROSS THE REST OF THE NORTH COUNTRY EARLY
MONDAY NIGHT ALLOWING FOR 850 TEMPS TO FALL TO AROUND -16 TO -18C.
WITH DEEP-LAYER DRYING TAKING PLACE AS HIGH PRESSURE BUILDS INTO THE
REGION OVERNIGHT TEMPERATURES MONDAY WILL BE QUITE COLD. ASIDE FROM
SOUTHERN VERMONT...MOST LOCATIONS WILL SEE LOWS THAT ARE BELOW ZERO
EVEN IN THE CHAMPLAIN VALLEY. I THINK THE COLDEST SPOT MONDAY NIGHT
WILL BE IN THE NORTHEAST KINGDOM AS THAT AREA IS FURTHEST REMOVED
FROM MID-LEVEL WARM ADVECTION CLOUDINESS WHICH IS PROJECTED TO SPILL
INTO NORTHERN NEW YORK LATE MONDAY NIGHT.
INCREASING CLOUDS THEN SPREAD ACROSS THE REST OF THE NORTH COUNTRY
TUESDAY AHEAD OF A MOISTURE-STARVED CLIPPER SYSTEM. DESPITE THE
FACT THAT MOISTURE WILL BE LIMITED WITH THE CLIPPER...ACCOMPANYING
ISENTROPIC LIFT AND RATHER HIGH SNOW/LIQUID RATIOS (15-20:1) DUE TO
COLD AIRMASS IN PLACE SHOULD ALLOW FOR AT LEAST A MODEST POWDERY
SNOW ACCUMULATION OF 1-3". THE ASSOCIATED COLD FRONT WILL THEN
USHER IN ANOTHER SHOT OF EVEN COLDER AIR TUESDAY NIGHT. NORTHWEST
WINDS WILL ALSO BE IN THE 15 TO 20 MPH RANGE WITH GUSTS TO 30 MPH
AS WELL FROM STRONGER MIXING. IT WOULDN`T BE SURPRISING IF SOME
LOCALES IN THE NORTHEAST KINGDOM AND NORTHERN NEW YORK HIT WIND
CHILL ADVISORY CRITERIA...WHICH WILL NEED TO BE MONITORED WITH LATER
SHIFTS. LOWS TUESDAY NIGHT MAY BE A FEW DEGREES WARMER THAN MONDAY
NIGHT (RANGING FROM THE LOWER SINGLE DIGITS TO 10 BELOW ZERO)...BUT
IT CERTAINLY WON`T FEEL THAT WAY GIVEN THE WINDS.
A RIDGE OF ARCTIC HIGH PRESSURE WILL EXTEND ACROSS THE NORTHERN
HALF OF THE NORTH COUNTRY ON WEDNESDAY...SEPERATING A DEVELOPING
EAST-WEST WARM FRONTAL BOUNDARY EXTENDING FROM A DISTURBANCE IN THE
GREAT LAKES. THE NORTH COUNTRY REMAINS ON THE COLD SIDE OF THIS
BOUNDARY THROUGHOUT WEDNESDAY...AND HAVE SHOWN INCREASING POPS FROM
SOUTH TO NORTH WEDNESDAY INTO WEDNESDAY NIGHT. I DO THINK THAT
THERE WILL PROBABLY BE A SHARP NORTH-SOUTH GRADIENT IN
PRECIPITATION GIVEN THE INFLUENCE OF THE ARCTIC HIGH WITH THE
HIGHEST POPS (CHANCE) CONFINED TO CENTRAL AND SOUTHERN VERMONT.
TEMPERATURES REMAIN COLD WITH HIGHS IN THE SINGLE DIGITS TO LOW
TEENS AND LOWS 0 TO 15 BELOW (COLDEST NORTH).
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 322 PM EST SUNDAY...CONSISTENCY IS GOOD AMONGST GLOBAL
MODELS INTO THURSDAY WITH SOME DIFFERENCES IN POSITION AND TRACK
OF A POTENTIAL COASTAL SYSTEM APPROACHING SOUTHERN NEW ENGLAND AND
ADJACENT COASTAL WATERS. THEME OF COLD TEMPERATURES CONTINUES
EARLY IN THIS PERIOD WITH AN INCREASING TREND TOWARD MORE ACTIVE
WEATHER FOR LATE IN THE WEEK.
LIGHT SNOWS SHOULD BE ONGOING TO OPEN THE EXTENDED WITH THE NORTH
COUNTRY ON THE NORTHERN SIDE OF A QUASI-STATIONARY BOUNDARY OVER
CENTRAL/SOUTHERN NEW ENGLAND. MEANWHILE...A MID-LEVEL SHORTWAVE
TROUGH MOVING ACROSS THE LOWER OHIO VALLEY WILL HELP TO ENERGIZE A
DEVELOPING COASTAL LOW NEAR THE CHESAPEAKE BAY AREA EARLY THURSDAY
MORNING. THE GFS TAKES THE DEVELOPING COASTAL NEAR OR JUST
SOUTHEAST OF THE 40N/70W BENCHMARK...WHILE THE ECMWF IS STRONGER
AND DECIDEDLY MORE INSIDE THE BENCHMARK. THOUGH BOTH MODELS SHOW A
DIFFERING CENTER TRACK...THE SOLUTIONS ARE AT LEAST CONSISTENT WITH
THEIR PRIOR COUPLE OF RUNS. BOTH GFS AND ECMWF SHOW A GOOD EASTERN
UPSLOPE PRECIPITATION ENHANCEMENT SIGNATURE AND HAVE SHOWN THE
HIGHEST POPS (LOW LIKELY) TOWARD THE EAST-FACING SLOPE AREAS FOR
THURSDAY NIGHT. LINGERING SNOWS CONTINUE INTO EARLY FRIDAY BEFORE
TAPERING THEREAFTER. IT`S STILL A LITTLE EARLY TO PROJECT SNOW
AMOUNTS WITH MORE SPECIFIC DETAILS WHICH STILL BE IRONED OUT...BUT
IT`S PROBABLY FAIR TO SAY THAT THERE WOULD BE SOME POTENTIAL IMPACT
FROM THIS COASTAL FOR THE NORTH COUNTRY. HIGHS THURSDAY AND FRIDAY
WILL STAY IN THE SINGLE DIGITS.
A LARGE-AMPLITUDE UPPER-LEVEL TROUGH THEN LINGERS OVER THE NORTH
COUNTRY FRIDAY NIGHT INTO SATURDAY WHICH WILL MAINTAIN CONTINUED
BITTER COLD. 850 TEMPS OF -24 TO -26C ALONG WITH AT LEAST PARTLY
CLOUDY SKIES SHOULD RESULT IN LOWS FRIDAY NIGHT AROUND -8 TO -16
BELOW. SOME INDICATION BY LATER IN THE WEEKEND THAT THE VERY COLD
TEMPERATURES FINALLY BEGIN TO MODERATE.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
THROUGH 18Z MONDAY...IFR/MVFR AS LOW PRESSURE TRACKS ACROSS
SOUTHEAST NEW ENGLAND BY MIDNIGHT AND WITH ARCTIC FRONT DRAPED
KMSS-KBTV.
PRECIPITATION TYPE IS TRICKY AS CURRENT TEMPS RANGING FROM 25 AT
KMSS TO ABOUT FREEZING OTHER SITES. MIXED PRECIP AT KBTV/KPBG/KSLK
AND SNOW AT KRUT/KMPV AND COMING DOWN MODERATLY. THIS WILL BE A QUICK
HITTER AS PRECIP TAPERS OFF BY AROUND MIDNIGHT LEAVING SOME
RESIDUAL -DZ -FZDZ DEPENDING UPON TEMPS WHICH WILL BE EITHER SIDE
OF 32.
EARLY TOMORROW MORNING, BASICALLY 06Z KMSS TO 09Z KBTV TO 11Z
KRUT/MPV, ARCTIC FRONTAL PASSAGE EXPECTED WITH SCATTERED BRIEF
HEAVIER SNOW SHOWER OR TWO, MOST PERSISTENT IN THE HIGHER
ELEVATIONS. TEMPS WILL FALL 20 DEGREES IN A COUPLE HOURS AND WINDS
WILL GUST AS HIGH AS 25 KTS PERHAPS 30KT SO WILL BE A QUICK ICE UP
OF RUNWAYS AND SOME DRIFTING.
EXPECTING IMPROVING CONDITIONS 15-21Z AS DRIER AIR MOVES IN AND
WINDS SETTLE DOWN SOMEWHAT.
OUTLOOK 00Z TUESDAY THROUGH FRIDAY...
MON NIGHT...VFR WITH LIGHT WINDSWITH ARCTIC AIR.
TUE...BECMG IFR IN PM LIGHT SNOW WITH LOW PRESSURE CLIPPER
SYSTEM.
WED...MAINLY VFR UNDER ARCTIC HIGH PRESSURE.
THU-FRI...BECMG IFR IN SNOW WITH LOW PRESSURE OFF THE COAST.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...MUCCILLI
SHORT TERM...LOCONTO
LONG TERM...LOCONTO
AVIATION...SISSON
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1140 PM CST SUN DEC 29 2013
.UPDATE...
ISSUED AT 1137 PM CST SUN DEC 29 2013
ADJUSTED TEMPERATURES ACROSS THE WESTERN FA TO GENERALLY STEADY
VALUES OVERNIGHT. ALSO ADJUSTED CLOUD TRENDS SLIGHTLY AND AGAIN
DELAYED POPS SLIGHTLY ACROSS THE WEST.
UPDATE ISSUED AT 934 PM CST SUN DEC 29 2013
WITH SURFACE RIDGE AXIS ACROSS WESTERN MN RESULTING IN LIGHT WINDS AND
ADVANCING CLOUDS FROM THE WEST ALLOWING TEMPERATURES TO MODERATE
HAVE CANCELLED THE WIND ADVISORY ACROSS THE FORECAST AREA. MADE
SOME MINOR TEMPERATURE ADJUSTMENTS ACROSS THE WEST OTHERWISE
MINIMUMS SEEM REASONABLE. BASED ON CURRENT RADAR TRENDS AND
MESOSCALE MODEL GUIDANCE HAVE DELAYED MOVING -SN INTO THE W-SW FA
UNTIL AFTER MIDNIGHT.
UPDATE ISSUED AT 628 PM CST SUN DEC 29 2013
NO CHANGES PLANNED THIS UPDATE PERIOD. APPARENT TEMPERATURES NOT
VERY IMPRESSIVE AT THIS POINT WITH LIGHT WINDS BUT WILL MONITOR.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 248 PM CST SUN DEC 29 2013
FORECAST CHALLENGE TONIGHT WILL BE EASTWARD EXTEND OF CLOUDS OVER
CENTRAL NORTH DAKOTA AND THEIR IMPACT ON TEMPS AND WIND CHILL
HEADLINES. OVERALL CLOUDS ADVECTING EAST QUICKER THAN INITIALLY
THOUGHT...AND MAY MAKE DEVILS LAKE BY 00Z. MODELS HAVE STRUGGLED
TO WITH PICKING UP ON THE MOISTURE...MAINLY HIGHLIGHTING THE
HIGHER CLOUDS OVER MINOT AND WEST. USING MAINLY SATELLITE TRENDS
FOR THE NEAR TERM AND MORE OF A ECMWF/NAM BLEND FOR THE EARLY PART
OF THE WEEK.
TONIGHT...CLOUDS WILL SLOWLY SPREAD INTO EASTERN ND AND APPROACH
THE RRV BY MIDNIGHT. A RATHER BULLISH CROSS SECTION FROM RUGBY TO
GRAND FORKS BRINGS CLOUDS INTO GFK BY 03Z..WHICH I THINK IS A BIT
TOO FAST. AS STATED PREVIOUSLY...MODELS ARE STRUGGLING WITH
ESPECIALLY THE LOWER CLOUDS THAT WERE PRESENT EARLY THIS MORNING.
THE RAP AVIATION FLIGHT RULES PRODUCT BRINGS THE LOW CLOUDS INTO
THE VALLEY AROUND THE 06Z/07Z TIME FRAME...BUT MID CLOUD SHOULD
ARRIVE PRIOR TO THAT. SO THE QUESTION BECOMES HOW FAST WILL TEMPS
DROP OFF AS THE SUN ANGLE DECREASES IN THE LATE AFTN...AND THEIR
IS ENOUGH WIND TO KEEP US IN ADVISORY CRITERIA THROUGH CURRENTLY
ADVERTISED TIMES. WILL NOT MAKE ANY CHANGES TO HEADLINES AT THIS
POINT BUT MAY SEE ADVISORY CANCELLED ACROSS EASTERN ND WELL AHEAD
OF SCHEDULE IF CLOUDS CAN LEVEL OFF THE TEMP CURVE QUICK ENOUGH.
OTHER ISSUE IS THAT WINDS ARE RATHER LIGHT...BUT ONLY TAKES 2 TO 3
KNOTS IN THE COLDEST AIR TO GET APPARENT TEMPS IN ADVISORY
CRITERIA. AGAIN...WILL KEEP HEADLINES IN PLACE AS IT IS GOING TO
BE DARN COLD TONIGHT WITHIN AND EAST OF THE VALLEY.
TOMORROW AND TOMORROW NIGHT...A WEAK WAVE WILL MOVE ACROSS CENTRAL
DAKOTAS AND SHOULD RESULT IN A BAND OF VERY DRY FLUFF ACROSS THE
CENTRAL PART OF THE STATE. THIS MAY CLIP THE SHEYENNE
VALLEY...WITH THE BEST CHANCES FOR UP TO TWO INCHES OF FLUFF BEING
FROM EDDY DOWN TO RANSOM/SARGENT COUNTIES. EXPECT SNOWFALL TO BE
INTO MAINLY WEST CENTRAL MN AFTER NOON...AND OUT OF THE REGION BY
EARLY MONDAY EVENING.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 248 PM CST SUN DEC 29 2013
TUESDAY AND WEDNESDAY...A SERIES OF WAVES EMBEDDED IN THE NW FLOW
PATTERN WILL BRING MORE CHANCES OF LIGHT SNOW MAINLY IN THE FAR
WEST ON TUE AND WED. THE WED SYSTEM...ALTHOUGH WEAKER AND
DRIER...SHOULD GIVE OUR CWA A LITTLE BETTER CHANCE AS THE UPPER
PATTERN SHIFTS EAST AND THE TRACK OF THE WAVES MOVES FROM THE
CENTRAL TO THE EASTERN DAKOTAS. EACH WAVE WILL GENERALLY BE MORE
DRY FLUFF THAT MAY ACCUMULATE AN INCH OR TWO DUE TO HIGH SNOWFALL
RATIOS WITH VERY LITTLE LIQUID EQUIVALENT.
WEDNESDAY NIGHT-SUNDAY...MODELS ARE IN GOOD AGREEMENT. THE PERIOD
STARTS WITH THE REGION IN NORTHWEST FLOW ALOFT...ALONG WITH HIGH
PRESSURE AND VERY COLD TEMPERATURES. THE UPPER PATTERN THEN
DEAMPLIFIES...ALLOWING ZONAL FLOW BY THE WEEKEND. THIS WILL LEAD TO
MUCH WARMER TEMPERATURES ON FRIDAY. A SYSTEM WILL MOVE THROUGH
SOUTHERN CANADA...SENDING A COLD FRONT THROUGH THE FA LATE FRIDAY OR
EARLY SATURDAY. LIGHT SNOW AND WINDY CONDITIONS POSSIBLE WITH THIS
FEATURE...ALTHOUGH DETAILS ARE FUZZY. TEMPERATURES WILL BE A BIT
COOLER FOR THE WEEKEND (COMPARED TO FRIDAY). MODELS SHOW A MUCH
STRONGER COLD FRONT POSSIBLE FOR LATER SUNDAY OR EARLY MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1137 PM CST SUN DEC 29 2013
MAINTAINED VFR CIGS ACROSS THE FA THROUGH THE FORECAST PERIOD.
LIGHT SNOW WILL SPREAD INTO THE SW THIRD OF THE FA BY SUNRISE.
COULD SEE SOME MVFR VSBY CLIP THE FAR TAF SITE DURING THE AM.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...SPEICHER
LONG TERM...TG/SPEICHER
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS MIAMI FL
1038 AM EST MON DEC 30 2013
.UPDATE...
NO SIGNIFICANT CHANGES TO THE SHORT TERM FORECAST. REGIONAL
OBSERVATIONS AND SATELLITE IMAGERY CONTINUES TO INDICATE LOW
STRATUS AND MOSTLY CLOUDY CONDITIONS ACROSS THE REGION WITH
ISOLATED SHOWERS MAINLY OBSERVED ACROSS THE OFF SHORE ATLANTIC
WATERS. CURRENT GUIDANCE INDICATES ABUNDANT LOW LEVEL MOISTURE AND
MOSTLY CLOUDY SKIES CONTINUING TONIGHT INTO TUESDAY AS THE FRONTAL
BOUNDARY STALLS ACROSS THE REGION...WITH PERIODS OF LOW STRATUS
ALSO CONTINUING TONIGHT INTO TUESDAY. PERIODIC ISOLATED SHOWERS
ARE ALSO POSSIBLE THROUGH THIS PERIOD AND INDICATED IN THE
FORECAST.
60
&&
.PREV DISCUSSION... /ISSUED 630 AM EST MON DEC 30 2013/
AVIATION...
A SLOW MOVING BOUNDARY, STILL JUST TO THE NORTH OF LAKE
OKEECHOBEE, WILL CONTINUE TO BRING A MID DECK OF CLOUDS TO SOUTH
FLORIDA TODAY. THERE WILL ALSO BE SOME LINGERING FOG AND LOW CIGS
FOR THE FIRST COUPLE OF HOURS AFTER SUNRISE. OTHERWISE, EXPECTING
MVFR TO VFR CONDITIONS. THERE IS ALSO A SLIGHT CHANCE OF SOME
RAIN SHOWERS THROUGH THE TAF PERIOD, NOT INCLUDED IN THE TAFS DUE
TO THE PROBABLE LIGHT NATURE OF THE SHOWERS. WINDS WILL BE VARIABLE FOR A
GOOD PART OF THE DAY AS WELL. THEY DO SEEM TO FAVOR THE NORTHEAST
LATER TONIGHT.
PREV DISCUSSION... /ISSUED 306 AM EST MON DEC 30 2013/
SHORT TERM (TODAY-WEDNESDAY)...
A LARGE SCALE MID/UPPER LEVEL TROUGH COVERS MOST OF EASTERN NORTH
AMERICA AT THIS TIME WITH A WEAKENING COLD FRONT NEAR OR JUST
SOUTH OF LAKE OKEECHOBEE EARLY THIS MORNING. THIS FRONT WILL ONLY
SAG VERY SLOWLY SOUTH AND STALL ACROSS EXTREME SOUTH FLORIDA LATER
TODAY. THIS IS DUE TO THE FACT THAT THE SUBTROPICAL RIDGE WILL
REMAIN ANCHORED ACROSS THE CARIBBEAN AND EXTEND NORTHEAST OVER
EASTERN CUBA AND INTO THE CENTRAL ATLANTIC. SOME PATCHY DENSE FOG
AND A LOW STRATUS DECK HAVE DEVELOPED ACROSS MUCH OF SOUTH FLORIDA
THIS MORNING AS A SURFACE BASED INVERSION HAS FORMED ALONG AND
AHEAD OF THE FRONT. EVEN AS THESE CLOUDS MIX OUT SHORTLY AFTER
SUNRISE, ABUNDANT MID LEVEL CLOUDS WILL LINGER WITH THE STALLING
FRONT AND POSSIBLY A FEW SHOWERS. THE NAM IS SUFFERING FROM ITS
TYPICAL MESOSCALE BIAS AND ITS HIGH POPS SEEM WAY OUT OF LINE AND
WENT MUCH CLOSER TO THE GFS AND ECMWF SOLUTIONS. THE HRRR ALSO
WAS NOT SHOWING MUCH SHOWER ACTIVITY THROUGH 16Z ALTHOUGH IT HAS
NOT RUN SINCE 01Z. STRONGER HIGH PRESSURE WILL BUILD OVER THE
SOUTHEAST STATES ON TUESDAY AS THE REMAINS OF AN ARCTIC COLD FRONT
MOVE INTO NORTH FLORIDA AND IT TOO WILL RAPIDLY BECOME DIFFUSE AS
THE RIDGE TO OUR SOUTH MOVES LITTLE. THIS WILL CREATE BREEZY
CONDITIONS ALONG OR NEAR THE ATLANTIC COAST WITH A FEW POSSIBLE
SHOWERS MOVING ONSHORE. BY NEW YEARS` DAY, A MID LEVEL TROUGH THAT
IS CURRENTLY OVER NORTHERN MEXICO WILL LIFT TO THE NORTHEAST INTO
THE SOUTHERN TIER OF STATES GENERATING A SURFACE LOW IN THE GULF
OF MEXICO. THE MODELS HAD BEEN INDICATING THE BAND OF MOISTURE
WOULD LINGER ACROSS SOUTH FLORIDA THROUGH THIS PERIOD BUT NOW SHOW
THE MOISTURE FIELD SHIFTING NORTHWARD ON WEDNESDAY. THE NAM IS THE
MOST AGGRESSIVE WITH SIGNIFICANT DRYING OCCURRING AND IT SHOWS PWAT
DROPPING TO UNDER AN INCH WHEREAS THE GFS AND ECMWF HAVE THE PWAT
HOVERING IN THE 1.25 TO 1.5 INCH RANGE. SO THERE COULD STILL BE A
FEW SHOWERS BUT IF THE NAM VERIFIES THERE WILL BE LITTLE IN THE
WAY OF CLOUD COVER.
LONG TERM (THURSDAY-SUNDAY)...
THE MOST SIGNIFICANT CHANGE IN THE LONG TERM CONTINUES TO BE THE
THREAT OF A STRONGER COLD FRONT. ALL MODELS ARE IN GOOD AGREEMENT
THAT A STRONG MID LEVEL TROUGH WILL MOVE INTO NEW ENGLAND EARLY
FRIDAY WITH ITS TRAILING COLD FRONT MOVING THROUGH SOUTH FLORIDA.
HOWEVER, THERE ALSO CONTINUES TO BE SOME DISCREPANCY AS TO HOW
COOL IT WILL GET BEHIND THE FRONT. THE ECMWF IS STILL THE MOST
AGGRESSIVE AND SHOWING MUCH COOLER TEMPERATURES FOR THE REGION
FRIDAY AND SATURDAY MORNING THAN THE OPERATIONAL GFS WHICH IS THE
WARMER MODEL WITH A RANGE ON SATURDAY MORNING FROM THE MID TO
UPPER 40S WEST OF LAKE OKEECHOBEE TO THE MID 60S ALONG THE
SOUTHEAST COAST. BUT THE GFS ENSEMBLE RUN HAS A 15-20 DEGREE RANGE
BETWEEN THE COOLEST AND WARMEST PERTURBATIONS ACROSS SOUTH FLORIDA
WITH POSSIBLE UPPER 30S OVER GLADES AND HENDRY COUNTIES. SO AT
THIS TIME, IT CONTINUES TO BE A WAIT AND SEE APPROACH AND WILL
STAY CLOSE TO THE MEX NUMBERS UNTIL THE MODEL HAS SOME MORE
CONSISTENCY BETWEEN RUNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 80 68 78 69 / 20 20 20 20
FORT LAUDERDALE 79 70 77 72 / 20 20 20 20
MIAMI 81 70 78 71 / 20 20 20 20
NAPLES 77 64 76 64 / 20 20 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...60/BD
AVIATION/RADAR...71/JE
AREA FORECAST DISCUSSION
NWS MIAMI FL
630 AM EST MON DEC 30 2013
.AVIATION...
A SLOW MOVING BOUNDARY, STILL JUST TO THE NORTH OF LAKE
OKEECHOBEE, WILL CONTINUE TO BRING A MID DECK OF CLOUDS TO SOUTH
FLORIDA TODAY. THERE WILL ALSO BE SOME LINGERING FOG AND LOW CIGS
FOR THE FIRST COUPLE OF HOURS AFTER SUNRISE. OTHERWISE, EXPECTING
MVFR TO VFR CONDITIONS. THERE IS ALSO A SLIGHT CHANCE OF SOME
RAIN SHOWERS THROUGH THE TAF PERIOD, NOT INCLUDED IN THE TAFS DUE
TO THE PROBABLE LIGHT NATURE OF THE SHOWERS. WINDS WILL BE VARIABLE FOR A
GOOD PART OF THE DAY AS WELL. THEY DO SEEM TO FAVOR THE NORTHEAST
LATER TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 306 AM EST MON DEC 30 2013/
SHORT TERM (TODAY-WEDNESDAY)...
A LARGE SCALE MID/UPPER LEVEL TROUGH COVERS MOST OF EASTERN NORTH
AMERICA AT THIS TIME WITH A WEAKENING COLD FRONT NEAR OR JUST
SOUTH OF LAKE OKEECHOBEE EARLY THIS MORNING. THIS FRONT WILL ONLY
SAG VERY SLOWLY SOUTH AND STALL ACROSS EXTREME SOUTH FLORIDA LATER
TODAY. THIS IS DUE TO THE FACT THAT THE SUBTROPICAL RIDGE WILL
REMAIN ANCHORED ACROSS THE CARIBBEAN AND EXTEND NORTHEAST OVER
EASTERN CUBA AND INTO THE CENTRAL ATLANTIC. SOME PATCHY DENSE FOG
AND A LOW STRATUS DECK HAVE DEVELOPED ACROSS MUCH OF SOUTH FLORIDA
THIS MORNING AS A SURFACE BASED INVERSION HAS FORMED ALONG AND
AHEAD OF THE FRONT. EVEN AS THESE CLOUDS MIX OUT SHORTLY AFTER
SUNRISE, ABUNDANT MID LEVEL CLOUDS WILL LINGER WITH THE STALLING
FRONT AND POSSIBLY A FEW SHOWERS. THE NAM IS SUFFERING FROM ITS
TYPICAL MESOSCALE BIAS AND ITS HIGH POPS SEEM WAY OUT OF LINE AND
WENT MUCH CLOSER TO THE GFS AND ECMWF SOLUTIONS. THE HRRR ALSO
WAS NOT SHOWING MUCH SHOWER ACTIVITY THROUGH 16Z ALTHOUGH IT HAS
NOT RUN SINCE 01Z. STRONGER HIGH PRESSURE WILL BUILD OVER THE
SOUTHEAST STATES ON TUESDAY AS THE REMAINS OF AN ARCTIC COLD FRONT
MOVE INTO NORTH FLORIDA AND IT TOO WILL RAPIDLY BECOME DIFFUSE AS
THE RIDGE TO OUR SOUTH MOVES LITTLE. THIS WILL CREATE BREEZY
CONDITIONS ALONG OR NEAR THE ATLANTIC COAST WITH A FEW POSSIBLE
SHOWERS MOVING ONSHORE. BY NEW YEARS` DAY, A MID LEVEL TROUGH THAT
IS CURRENTLY OVER NORTHERN MEXICO WILL LIFT TO THE NORTHEAST INTO
THE SOUTHERN TIER OF STATES GENERATING A SURFACE LOW IN THE GULF
OF MEXICO. THE MODELS HAD BEEN INDICATING THE BAND OF MOISTURE
WOULD LINGER ACROSS SOUTH FLORIDA THROUGH THIS PERIOD BUT NOW SHOW
THE MOISTURE FIELD SHIFTING NORTHWARD ON WEDNESDAY. THE NAM IS THE
MOST AGGRESSIVE WITH SIGNIFICANT DRYING OCCURRING AND IT SHOWS PWAT
DROPPING TO UNDER AN INCH WHEREAS THE GFS AND ECMWF HAVE THE PWAT
HOVERING IN THE 1.25 TO 1.5 INCH RANGE. SO THERE COULD STILL BE A
FEW SHOWERS BUT IF THE NAM VERIFIES THERE WILL BE LITTLE IN THE
WAY OF CLOUD COVER.
LONG TERM (THURSDAY-SUNDAY)...
THE MOST SIGNIFICANT CHANGE IN THE LONG TERM CONTINUES TO BE THE
THREAT OF A STRONGER COLD FRONT. ALL MODELS ARE IN GOOD AGREEMENT
THAT A STRONG MID LEVEL TROUGH WILL MOVE INTO NEW ENGLAND EARLY
FRIDAY WITH ITS TRAILING COLD FRONT MOVING THROUGH SOUTH FLORIDA.
HOWEVER, THERE ALSO CONTINUES TO BE SOME DISCREPANCY AS TO HOW
COOL IT WILL GET BEHIND THE FRONT. THE ECMWF IS STILL THE MOST
AGGRESSIVE AND SHOWING MUCH COOLER TEMPERATURES FOR THE REGION
FRIDAY AND SATURDAY MORNING THAN THE OPERATIONAL GFS WHICH IS THE
WARMER MODEL WITH A RANGE ON SATURDAY MORNING FROM THE MID TO
UPPER 40S WEST OF LAKE OKEECHOBEE TO THE MID 60S ALONG THE
SOUTHEAST COAST. BUT THE GFS ENSEMBLE RUN HAS A 15-20 DEGREE RANGE
BETWEEN THE COOLEST AND WARMEST PERTURBATIONS ACROSS SOUTH FLORIDA
WITH POSSIBLE UPPER 30S OVER GLADES AND HENDRY COUNTIES. SO AT
THIS TIME, IT CONTINUES TO BE A WAIT AND SEE APPROACH AND WILL
STAY CLOSE TO THE MEX NUMBERS UNTIL THE MODEL HAS SOME MORE
CONSISTENCY BETWEEN RUNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 80 68 78 69 / 20 20 20 20
FORT LAUDERDALE 79 70 77 72 / 20 20 20 20
MIAMI 81 70 78 71 / 20 20 20 20
NAPLES 77 64 76 64 / 20 20 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...30/KOB
AVIATION/RADAR...13/SI
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
644 AM EST MON DEC 30 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 540 AM EST MON DEC 30 2013
WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW FROM
CENTRAL CANADA INTO THE NRN GREAT LAKES AROUND THE POLAR VORTEX OVER
HUDSON BAY. ONE IN A SERIES OF CLIPPER SHORTWAVE TROUGHS OVER THE
NRN PLAINS SUPPORTED AN AREA OF LIGHT SNOW OVER THE DAKOTAS. AT THE
SFC...DIMINISHING WNW WINDS PREVAILED ACROSS THE REGION AHEAD
OF THE ARCTIC HIGH PRES RIDGE EXTENDING FROM NRN ALBERTA INTO THE
UPPER MS VALLEY. RADAR INDICATED WEAK MULTIPLE WIND PARALLEL LES
BANDS INTO UPPER MICHIGAN FROM MUNISING EASTWARD. ALTHOUGH 850 MB
TEMPS REMAINED AROUND -23C...INVERSION HEIGHTS AROUND 5K FT AND THE
VERY DRY UPSTREAM AIRMASS HAS LIMITED LES INTENSITY WITH LIGHT
SNOWFALL RATES OF SMALLER SNOWFLAKES. SATELLITE...SFC OBS AND WEB
CAMS ALSO INDICATED PERSIST LIGHT LES INTO THE WEST. IN AREAS WHERE
SKIES HAD CLEARED...INLAND TEMPS HAVE FALLEN OFF TO -10F TO -20F.
EVEN WITH RELATIVELY LIGHT WINDS OF 5 TO 10 MPH...WIND CHILL VALUES
HAD DROPPED INTO THE ADVISORY (-25 TO -30) RANGE.
TODAY...THE MODELS WERE CONSISTENT IN KEEPING THE LIGHT SNOW
ASSOCIATED WITH THE STRONGER FORCING AND ISENTROPIC LIFT ASSOCIATED
WITH THE SHRTWV SOUTH OF UPPER MI. HOWEVER...THE SHRTWV WILL BRING
BACKING WINDS TOWARD WRLY THAT WILL PUSH THE LES OVER THE EAST
OFFSHORE. THE BACKING TREND MAY ALSO RESULT IN ENHANCED LOW LEVEL
CONV IN THE KEWEENAW AND A PERIOD OF SLIGHTLY HEAVIER LES.
OTHERWISE...DIURNAL WARMING SHOULD BRING MODERATING WIND CHILL
VALUES BY MID MORNING. MAINLY JUST HIGH CLOUDS ARE EXPECTED OVER
MUCH OF THE CWA WITH TEMPS CLIMBING TO 0F TO 5F WEST AND CLOSER TO
10F ALONG LAKE SUPERIOR AND EAST.
TONIGHT...WITH A TROUGH ACROSS SRN LAKE SUPERIOR...THE HIGHER RES
MODELS SUGGEST A MESO-LOW MAY DEVELOP OVER THE SE PORTION OF THE LAKE
THAT MAY DROP INTO THE NE CWA EAST OF MUNISING OVERNIGHT AS WINDS
VEER AND INCREASE BEHIND THE SHRTWV. THIS COULD PRODUCE A PERIOD OF
HEAVY SNOW AS STRONGER MOISTURE/HEAT FLUX OFF THE LAKE IN THE CLOSED
CIRCULATION BRING THE DGZ INTO THE CONVECTIVE LAYER WITH POTENTIALLY
INTENSE LES BANDS. HOWEVER...AS EXPECTED WITH MESOSCALE
FEATURES...THERE IS STILL SIGNIFICANT UNCERTAINTY WITH THE
TIMING/LOCATION/DURATION OF ANY HEAVIER SNOW. SO...THE LES WATCH WAS
RETAINED. THE GREATEST ACCUMULATIONS ARE LIKELY FROM PICTURED ROCKS
AND GRAND MARAIS INTO NRN LUCE COUNTY. ALTHOUGH TEMPS ARE NOT
EXPECTED TO DROP AS MUCH TONIGHT WITH GREATER CLOUD COVER...SLIGHTLY
STRONGER WINDS MAY PUSH WIND CHILLS BACK INTO THE ADVISORY RANGE OVER
THE THE INTERIOR WEST HALF.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 506 AM EST MON DEC 30 2013
TAKING A LOOK AT THE LARGE SCALE PATTERN...THE UPPER GREAT LAKES
WILL REMAIN DOMINATED BY A TROUGH AT 500MB THROUGH THURSDAY. EVEN
WHEN THE MAIN 500MB LOW DOES EXIT OFF THE NE CANADIAN COAST ON
SATURDAY...ANOTHER LOW SITUATED OVER N CENTRAL CANADA FRIDAY NIGHT
LOOKS TO DIVE ACROSS S CENTRAL CANADA FOR THE LATTER HALF OF THE
WEEKEND. THE ONLY DAYS WHERE THE MERCURY MAY RISE AT OR ABOVE 20F
LOOKS TO BE SATURDAY...AND TO A LESSER EXTENT SUNDAY.
VERY COLD TUESDAY NIGHT...
GIVEN THE COLD AIR LOCKED IN PLACE...ANY MODERATE OR STRONG WINDS
WILL RESULT IN DANGEROUS WIND CHILLS. WIND CHILL VALUES WILL LIKELY
FALL TO THESE DANGEROUS VALUES TUESDAY NIGHT AS STRONG/COLD HIGH
PRESSURE SURGES IN AGAIN FROM THE NW. HOWEVER...WITH WINDS IN THE
COLDEST LOCATIONS LESS THAN OUR 10MPH WIND CHILL ADVISORY/WARNING
CRITERIA...HEADLINES MAY NOT BE POSTED /ALTHOUGH NAM GUIDANCE IS
NEAR/. WE WILL CONTINUE TO HIGHLIGHT THE DANGER HERE...IN THE
HWO...AND WITH SOCIAL MEDIA. THE GFS-MOS CAME IN WITH A FCST LOW OF
-22F AT CHAMPION/VAN RIPER...WITH -17F AT BOTH BERGLAND DAM AND IWD.
CONTINUED LAKE EFFECT SNOW SHOWERS THROUGH THURSDAY...MODERATE TO
HEAVY LES MAY BE ONGOING FOR MAINLY E ALGER/N SCHOOLCRAFT/N LUCE
COUNTIES TUESDAY MORNING. CONTINUED NW FLOW ON COLD AIR AVERAGING
-20 TO -23C AT 850MB WILL BE THE RULE UNTIL APPROX 6Z WEDNESDAY WHEN
THE WINDS BECOME DISRUPTED AS THE SFC TROUGH/LOW STUCK OVER SE LAKE
SUPERIOR WEAKENS AND BECOMES ABSORBED BY THE HIGH SET UP TO OUR NW.
WITH A MESO-LOW LIKELY DEVELOPING IT WILL BE DIFFICULT TO PIN POINT
WHERE AND FOR HOW LONG A DOMINANT BAND OF SNOW MAY
DEVELOP...ANYWHERE FROM NEAR MUNISING TO EAST OF GRAND MARAIS. WILL
WAIT FOR NEAR TERM MODELS TO COME INTO BETTER AGREEMENT BEFORE
REDUCING WATCH TO ADVISORIES...OR HOISTING LES WARNINGS FOR ALGER
AND LUCE COUNTIES.
LES WILL CONTINUE WEDNESDAY INTO THURSDAY...MAINLY ON THE N AND NE
SNOWBELTS. LATEST GUIDANCE INDICATES THE POTENTIAL FOR 3-8IN OF SNOW
ACROSS THE HURON MOUNTAINS FROM LATE WEDNESDAY MORNING THROUGH EARLY
THURSDAY MORNING. HEADLINES MAY BE NEEDED AS THE TIME NEARS.
WARMER AIR THIS WEEKEND...
AS NOTED PREVIOUSLY A SURGE OF RELATIVELY WARM AIR IS FIGURED FOR
THE UPCOMING WEEKEND. THE 30/00Z RUN OF THE GFS INCREASED THE 850MB
WINDS BY APPROX 5-10KTS...WITH THE ECMWF AND GFS SHOWING BETWEEN 40
AND 65KT SW TO W LLJ FROM ROUGHLY 00-18Z SATURDAY. THIS WILL ALLOW
850MB TEMPS TO RISE UP TO -4 TO -8C. AHEAD OF THE SFC LOW SET UP
FROM THE PLAINS STATES THROUGH W ONTARIO...RISING OVERNIGHT TEMPS
WILL BE LIKELY FRIDAY NIGHT INTO SATURDAY. THERE OF COURSE ARE SOME
TIMING DIFFERENCES...WITH THE LOW AND ITS ASSOCIATED COLD FRONT
BEING 6-12HRS QUICK OFF THE LATEST GFS. THE SLOWER ECMWF SOLUTION IS
BACKED UP AT LEAST EARLY SATURDAY BY THE CANADIAN AND DGEX.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 643 AM EST MON DEC 30 2013
IWD...ALTHOUGH SOME LIGHT SNOW IN ADVANCE OF ANOTHER DISTURBANCE MAY
ARRIVE LATE THIS AFTERNOON...CONDITIONS ARE LIKELY TO REMAIN VFR AS
THIS SYSTEM WILL BE MOISTURE DEPRIVED AND THE STRONGER DYNAMICS WILL
REMAIN TO THE SOUTH. A WIND SHIFT TO THE WNW IN ITS WAKE MAY
BRING A RETURN OF LK EFFECT -SHSN AND MVFR CONDITIONS DURING THE
EVNG.
CMX...WITH A SLOWLY BACKING NW TO W FLOW OF ARCTIC AIR...EXPECT LAKE
EFFECT -SHSN AND PREDOMINANT IFR VSBYS TO PERSIST THRU THE FCST
PERIOD. SHARPENING LOW LEVEL CONVERGENCE COINCIDENT WITH THE PASSAGE OF A
STRONGER DISTURBANCE/ACCOMPANYING LOW PRES TROF PASSAGE MAY BRING A
PERIOD OF HEAVIER SHSN/LIFR CONDITIONS LATE THIS AFTERNOON OR
EVENING.
SAW...WITH A DOWNSLOPE W WIND FLOW OF DRY ARCTIC AIR...EXPECT VFR
CONDITIONS TO DOMINATE THIS LOCATION THE ENTIRE FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 540 AM EST MON DEC 30 2013
WEST NORTHWEST WINDS TO 25 KNOTS ARE EXPECTED TO SLOWLY
DIMINISH...REDUCING THE POTENTIAL FOR FREEZING SPRAY OVER THE LAKE BY
THIS AFTERNOON. AS THE LINGERING SURFACE TROUGH OVER EASTERN LAKE
SUPERIOR STRENGTHENS TONIGHT AND SHIFTS EAST ON
TUESDAY...NORTHWESTERLY WINDS WILL INCREASE WITH SOME GUSTS TO 30KTS
OVER THE EASTERN LAKE TUESDAY AFTERNOON AND EVENING. THIS WILL ALSO
BRING AN INCREASED OPPORTUNITY FOR HEAVY FREEZING SPRAY THROUGH
TUESDAY NIGHT OVER THE EASTERN HALF OF LAKE SUPERIOR. ALTHOUGH THERE
STILL WILL BE A LINGERING TROUGH OVER EASTERN LAKE SUPERIOR INTO
WEDNESDAY...HIGH PRESSURE BUILDING OVER THE UPPER MISSISSIPPI VALLEY
WILL LEAD TO LIGHTER NORTHWESTERLY WINDS FOR WEDNESDAY AND
THURSDAY...BRINGING AN END TO THE POTENTIAL FOR HEAVY FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY UNTIL 10 AM EST /9 AM CST/ THIS MORNING FOR
MIZ002-004-005-009>011-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ085.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ006-007.
LAKE EFFECT SNOW WATCH FROM THIS EVENING THROUGH TUESDAY EVENING
FOR MIZ006-007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR
LSZ248>251-264-267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR LSZ266.
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
LSZ265.
HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 1 AM EST
WEDNESDAY FOR LSZ264.
HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 4 AM EST
WEDNESDAY FOR LSZ248>250.
HEAVY FREEZING SPRAY WARNING FROM 10 PM EST /9 PM CST/ THIS
EVENING TO 10 PM EST /9 PM CST/ TUESDAY FOR LSZ241>244.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
543 AM EST MON DEC 30 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 540 AM EST MON DEC 30 2013
WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW FROM
CENTRAL CANADA INTO THE NRN GREAT LAKES AROUND THE POLAR VORTEX OVER
HUDSON BAY. ONE IN A SERIES OF CLIPPER SHORTWAVE TROUGHS OVER THE
NRN PLAINS SUPPORTED AN AREA OF LIGHT SNOW OVER THE DAKOTAS. AT THE
SFC...DIMINISHING WNW WINDS PREVAILED ACROSS THE REGION AHEAD
OF THE ARCTIC HIGH PRES RIDGE EXTENDING FROM NRN ALBERTA INTO THE
UPPER MS VALLEY. RADAR INDICATED WEAK MULTIPLE WIND PARALLEL LES
BANDS INTO UPPER MICHIGAN FROM MUNISING EASTWARD. ALTHOUGH 850 MB
TEMPS REMAINED AROUND -23C...INVERSION HEIGHTS AROUND 5K FT AND THE
VERY DRY UPSTREAM AIRMASS HAS LIMITED LES INTENSITY WITH LIGHT
SNOWFALL RATES OF SMALLER SNOWFLAKES. SATELLITE...SFC OBS AND WEB
CAMS ALSO INDICATED PERSIST LIGHT LES INTO THE WEST. IN AREAS WHERE
SKIES HAD CLEARED...INLAND TEMPS HAVE FALLEN OFF TO -10F TO -20F.
EVEN WITH RELATIVELY LIGHT WINDS OF 5 TO 10 MPH...WIND CHILL VALUES
HAD DROPPED INTO THE ADVISORY (-25 TO -30) RANGE.
TODAY...THE MODELS WERE CONSISTENT IN KEEPING THE LIGHT SNOW
ASSOCIATED WITH THE STRONGER FORCING AND ISENTROPIC LIFT ASSOCIATED
WITH THE SHRTWV SOUTH OF UPPER MI. HOWEVER...THE SHRTWV WILL BRING
BACKING WINDS TOWARD WRLY THAT WILL PUSH THE LES OVER THE EAST
OFFSHORE. THE BACKING TREND MAY ALSO RESULT IN ENHANCED LOW LEVEL
CONV IN THE KEWEENAW AND A PERIOD OF SLIGHTLY HEAVIER LES.
OTHERWISE...DIURNAL WARMING SHOULD BRING MODERATING WIND CHILL
VALUES BY MID MORNING. MAINLY JUST HIGH CLOUDS ARE EXPECTED OVER
MUCH OF THE CWA WITH TEMPS CLIMBING TO 0F TO 5F WEST AND CLOSER TO
10F ALONG LAKE SUPERIOR AND EAST.
TONIGHT...WITH A TROUGH ACROSS SRN LAKE SUPERIOR...THE HIGHER RES
MODELS SUGGEST A MESO-LOW MAY DEVELOP OVER THE SE PORTION OF THE LAKE
THAT MAY DROP INTO THE NE CWA EAST OF MUNISING OVERNIGHT AS WINDS
VEER AND INCREASE BEHIND THE SHRTWV. THIS COULD PRODUCE A PERIOD OF
HEAVY SNOW AS STRONGER MOISTURE/HEAT FLUX OFF THE LAKE IN THE CLOSED
CIRCULATION BRING THE DGZ INTO THE CONVECTIVE LAYER WITH POTENTIALLY
INTENSE LES BANDS. HOWEVER...AS EXPECTED WITH MESOSCALE
FEATURES...THERE IS STILL SIGNIFICANT UNCERTAINTY WITH THE
TIMING/LOCATION/DURATION OF ANY HEAVIER SNOW. SO...THE LES WATCH WAS
RETAINED. THE GREATEST ACCUMULATIONS ARE LIKELY FROM PICTURED ROCKS
AND GRAND MARAIS INTO NRN LUCE COUNTY. ALTHOUGH TEMPS ARE NOT
EXPECTED TO DROP AS MUCH TONIGHT WITH GREATER CLOUD COVER...SLIGHTLY
STRONGER WINDS MAY PUSH WIND CHILLS BACK INTO THE ADVISORY RANGE OVER
THE THE INTERIOR WEST HALF.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 506 AM EST MON DEC 30 2013
TAKING A LOOK AT THE LARGE SCALE PATTERN...THE UPPER GREAT LAKES
WILL REMAIN DOMINATED BY A TROUGH AT 500MB THROUGH THURSDAY. EVEN
WHEN THE MAIN 500MB LOW DOES EXIT OFF THE NE CANADIAN COAST ON
SATURDAY...ANOTHER LOW SITUATED OVER N CENTRAL CANADA FRIDAY NIGHT
LOOKS TO DIVE ACROSS S CENTRAL CANADA FOR THE LATTER HALF OF THE
WEEKEND. THE ONLY DAYS WHERE THE MERCURY MAY RISE AT OR ABOVE 20F
LOOKS TO BE SATURDAY...AND TO A LESSER EXTENT SUNDAY.
VERY COLD TUESDAY NIGHT...
GIVEN THE COLD AIR LOCKED IN PLACE...ANY MODERATE OR STRONG WINDS
WILL RESULT IN DANGEROUS WIND CHILLS. WIND CHILL VALUES WILL LIKELY
FALL TO THESE DANGEROUS VALUES TUESDAY NIGHT AS STRONG/COLD HIGH
PRESSURE SURGES IN AGAIN FROM THE NW. HOWEVER...WITH WINDS IN THE
COLDEST LOCATIONS LESS THAN OUR 10MPH WIND CHILL ADVISORY/WARNING
CRITERIA...HEADLINES MAY NOT BE POSTED /ALTHOUGH NAM GUIDANCE IS
NEAR/. WE WILL CONTINUE TO HIGHLIGHT THE DANGER HERE...IN THE
HWO...AND WITH SOCIAL MEDIA. THE GFS-MOS CAME IN WITH A FCST LOW OF
-22F AT CHAMPION/VAN RIPER...WITH -17F AT BOTH BERGLAND DAM AND IWD.
CONTINUED LAKE EFFECT SNOW SHOWERS THROUGH THURSDAY...MODERATE TO
HEAVY LES MAY BE ONGOING FOR MAINLY E ALGER/N SCHOOLCRAFT/N LUCE
COUNTIES TUESDAY MORNING. CONTINUED NW FLOW ON COLD AIR AVERAGING
-20 TO -23C AT 850MB WILL BE THE RULE UNTIL APPROX 6Z WEDNESDAY WHEN
THE WINDS BECOME DISRUPTED AS THE SFC TROUGH/LOW STUCK OVER SE LAKE
SUPERIOR WEAKENS AND BECOMES ABSORBED BY THE HIGH SET UP TO OUR NW.
WITH A MESO-LOW LIKELY DEVELOPING IT WILL BE DIFFICULT TO PIN POINT
WHERE AND FOR HOW LONG A DOMINANT BAND OF SNOW MAY
DEVELOP...ANYWHERE FROM NEAR MUNISING TO EAST OF GRAND MARAIS. WILL
WAIT FOR NEAR TERM MODELS TO COME INTO BETTER AGREEMENT BEFORE
REDUCING WATCH TO ADVISORIES...OR HOISTING LES WARNINGS FOR ALGER
AND LUCE COUNTIES.
LES WILL CONTINUE WEDNESDAY INTO THURSDAY...MAINLY ON THE N AND NE
SNOWBELTS. LATEST GUIDANCE INDICATES THE POTENTIAL FOR 3-8IN OF SNOW
ACROSS THE HURON MOUNTAINS FROM LATE WEDNESDAY MORNING THROUGH EARLY
THURSDAY MORNING. HEADLINES MAY BE NEEDED AS THE TIME NEARS.
WARMER AIR THIS WEEKEND...
AS NOTED PREVIOUSLY A SURGE OF RELATIVELY WARM AIR IS FIGURED FOR
THE UPCOMING WEEKEND. THE 30/00Z RUN OF THE GFS INCREASED THE 850MB
WINDS BY APPROX 5-10KTS...WITH THE ECMWF AND GFS SHOWING BETWEEN 40
AND 65KT SW TO W LLJ FROM ROUGHLY 00-18Z SATURDAY. THIS WILL ALLOW
850MB TEMPS TO RISE UP TO -4 TO -8C. AHEAD OF THE SFC LOW SET UP
FROM THE PLAINS STATES THROUGH W ONTARIO...RISING OVERNIGHT TEMPS
WILL BE LIKELY FRIDAY NIGHT INTO SATURDAY. THERE OF COURSE ARE SOME
TIMING DIFFERENCES...WITH THE LOW AND ITS ASSOCIATED COLD FRONT
BEING 6-12HRS QUICK OFF THE LATEST GFS. THE SLOWER ECMWF SOLUTION IS
BACKED UP AT LEAST EARLY SATURDAY BY THE CANADIAN AND DGEX.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1247 AM EST MON DEC 30 2013
IWD...AS THE LLVL FLOW BACKS SLOWLY TOWARD THE WSW THRU THE NGT...
EXPECT LINGERING -SHSN/CLDS TO SHIFT TO THE N...WITH A TREND TOWARD
PREDOMINANT VFR WX. ALTHOUGH SOME LGT SN IN ADVANCE OF ANOTHER
DISTURBANCE MAY ARRIVE LATE MON AFTN...CONDITIONS ARE LIKELY TO
REMAIN VFR AS THIS SYS WL BE MSTR DEPRIVED AND THE SHARPER DYNAMICS
WL REMAIN TO THE S. A WSHFT TOWARD THE WNW IN ITS WAKE MAY BRING A
RETURN OF LK EFFECT -SHSN AND MVFR CONDITIONS DURING THE EVNG.
CMX...WITH A SLOWLY BACKING NW TO W FLOW OF ARCTIC AIR...EXPECT LK
EFFECT -SHSN AND PREDOMINANT IFR VSBYS TO PERSIST THRU THE FCST
PERIOD. SHARPENING LLVL CNVGC COINCIDENT WITH THE PASSAGE OF A
STRONGER DISTURBANCE/ACCOMPANYING LO PRES TROF PASSAGE MAY BRING A
PERIOD OF HEAVIER SHSN/LIFR CONDITIONS THIS EVNG.
SAW...WITH A DOWNSLOPE W WIND FLOW OF DRY ARCTIC AIR...EXPECT VFR
CONDITIONS TO DOMINATE THIS LOCATION THE ENTIRE FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 540 AM EST MON DEC 30 2013
WEST NORTHWEST WINDS TO 25 KNOTS ARE EXPECTED TO SLOWLY
DIMINISH...REDUCING THE POTENTIAL FOR FREEZING SPRAY OVER THE LAKE BY
THIS AFTERNOON. AS THE LINGERING SURFACE TROUGH OVER EASTERN LAKE
SUPERIOR STRENGTHENS TONIGHT AND SHIFTS EAST ON
TUESDAY...NORTHWESTERLY WINDS WILL INCREASE WITH SOME GUSTS TO 30KTS
OVER THE EASTERN LAKE TUESDAY AFTERNOON AND EVENING. THIS WILL ALSO
BRING AN INCREASED OPPORTUNITY FOR HEAVY FREEZING SPRAY THROUGH
TUESDAY NIGHT OVER THE EASTERN HALF OF LAKE SUPERIOR. ALTHOUGH THERE
STILL WILL BE A LINGERING TROUGH OVER EASTERN LAKE SUPERIOR INTO
WEDNESDAY...HIGH PRESSURE BUILDING OVER THE UPPER MISSISSIPPI VALLEY
WILL LEAD TO LIGHTER NORTHWESTERLY WINDS FOR WEDNESDAY AND
THURSDAY...BRINGING AN END TO THE POTENTIAL FOR HEAVY FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY UNTIL 10 AM EST /9 AM CST/ THIS MORNING FOR
MIZ002-004-005-009>011-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ085.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ006-007.
LAKE EFFECT SNOW WATCH FROM THIS EVENING THROUGH TUESDAY EVENING
FOR MIZ006-007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR
LSZ248>251-264-267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR LSZ266.
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
LSZ265.
HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 1 AM EST
WEDNESDAY FOR LSZ264.
HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 4 AM EST
WEDNESDAY FOR LSZ248>250.
HEAVY FREEZING SPRAY WARNING FROM 10 PM EST /9 PM CST/ THIS
EVENING TO 10 PM EST /9 PM CST/ TUESDAY FOR LSZ241>244.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
507 AM EST MON DEC 30 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 424 PM EST SUN DEC 29 2013
ARCTIC AIR AND CONTINUED LAKE EFFECT OFF LAKE SUPERIOR WILL BE THE
MAIN CONCERNS FOR THE SHORT TERM PERIOD.
THE SURFACE LOW THAT BROUGHT THE SURGE OF COLD AIR CONTINUES TO
SLIDE EAST OF THE AREA...WHILE HIGH PRESSURE HAS BUILT INTO THE
NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY. THE EXITING LOW HAS
LEFT A SURFACE TROUGH OVER EASTERN LAKE SUPERIOR. ALOFT...AREA IS
UNDER AN UPPER TROUGH THAT COVERS MUCH OF THE EASTERN CONUS AND HAS
LED TO ARCTIC AIR SPILLING SOUTHEAST OVER THE UPPER GREAT LAKES LAST
NIGHT. THIS COLD AIR HAS BEEN PRODUCING LAKE EFFECT SNOW SHOWERS IN
THE NORTH-NORTHWEST WIND LOCATIONS TODAY. LATEST RADAR/SATELLITE
DATA INDICATES THE BEST BANDS OVER FAR EASTERN MARQUETTE COUNTY
AND ALGER COUNTIES...WHERE RADAR RETURNS HAVE BEEN REACHING
7KFT. HAVE STARTED SEEING THE LOW LEVEL WINDS BACKING ASSOCIATED
WITH THE HIGH PRESSURE RIDGE OVER THE LAST FEW HOURS...ESPECIALLY
OVER THE WESTERN LAKE...AND THAT HAS STARTED TO PUSH THE BANDS OVER
MARQUETTE COUNTY EASTWARD. WITH AT LEAST HALF OF THE CLOUD BEING
ABOVE THE DGZ BASED ON RAP INITIAL SOUNDINGS...CALLS TO SPOTTERS
HAS INDICATED JUST A COUPLE INCHES OF ADDITIONAL SNOW
ACCUMULATION TODAY. THE BIGGEST ISSUE HAS BEEN THE SMALL FLAKES
REDUCING VISIBILITIES...ALONG WITH GUSTY WINDS TO 30-35MPH EAST
OF MARQUETTE...AND CAUSING BRIEF WHITEOUTS ALONG M-28 IN ALGER
COUNTY. A CALL TO THE ALGER COUNTY SHERIFF INDICATED SEVERAL
ACCIDENTS ON THAT STRETCH...WITH THEM ENCOURAGING TRAVEL ALONG
M-94 INSTEAD.
WITH THE COLD AIR IN PLACE AND SOME LOW LEVEL MOISTURE...EXPECT THE
LAKE EFFECT TO CONTINUE THROUGH THE SHORT TERM PERIOD. THE
LOCATION OF THE SNOW WILL BE DETERMINED BY BOUNDARY LAYER WINDS.
SINCE THE HIGH OVER SOUTHEAST SOUTH DAKOTA WILL DRIFT TO THE
SOUTHEAST THROUGH THE NIGHT...IT WILL PUSH A RIDGE INTO THE
SOUTHWEST HALF OF UPPER MICHIGAN. THIS RIDGE WILL DO TWO
THINGS...BACK THE WINDS TO MORE OF A WEST-NORTHWEST DIRECTION AND
CONTINUE TO PROVIDE DRY AIR AND SUBSIDENCE ABOVE 850MB. THOSE
BACKING WINDS WILL ALSO BE AIDED BY A SHORTWAVE DEPARTING THE
CANADIAN ROCKIES AND MOVING INTO THE NORTHERN PLAINS ON
MONDAY. THIS WILL LEAD TO WINDS TRANSITIONING FROM THE
NORTH-NORTHWEST LATE THIS AFTERNOON TO THE NORTHWEST THIS EVENING
AND EVENTUALLY NEARLY WESTERLY BY 18Z MONDAY. THEREFORE...WOULD
EXPECT THE PURE LAKE EFFECT BANDS (NO SHORTWAVE HELP) TO FOLLOW
SUIT. 850MB TEMPS WILL REMAIN FAIRLY STEADY THROUGH MONDAY AND
AROUND -23C...LEADING TO DELTA-T VALUES AROUND THE MID 20S. BUT
THIS COLD AIR WILL LEAD TO MUCH OF THE CLOUD BEING AT THE HIGH END
OF THE DGZ OR ABOVE IT...SO WOULD EXPECT SNOW RATIOS TO BE ON THE
LOWER END FOR LAKE EFFECT AND IN MOST SITUATIONS BELOW 20 TO 1. IN
THE STRONGEST BANDS OVER THE EAST AND THE BETTER LAKE
MODIFICATION...DID KEEP SOME LOW 20S IN THE FORECAST. AS SEEN ON
SATELLITE NEAR IRONWOOD THIS AFTERNOON...THE STRONGEST BANDS
WILL BE ON THE SOUTHWEST EDGE OF THE LES DUE TO THE ENHANCED
CONVERGENCE FROM THE BACKING WINDS. ALTHOUGH THIS WILL STRENGTHEN
THE BANDS...THINK THE CONSISTENT BACKING FLOW (ALONG WITH THE LOWER
RATIOS) WILL BE ENOUGH TO KEEP AMOUNTS GENERALLY LIGHT. HAVE KEPT
AMOUNTS FAIRLY SIMILAR TO WHAT WAS SEEN DURING THE DAY TODAY IN THE
LES LOCATIONS (1-2.5IN)...BUT DO HAVE SLIGHTLY HIGHER AMOUNTS
(APPROACHING 4) OVER THE EAST WITH THE SLOWER BACKING TREND. THE
LONGER FETCH WITH THE WEST TO WEST-SOUTHWEST WINDS OVER WESTERN
LAKE SUPERIOR COULD LEAD TO AN INCREASE IN INTENSITY OF THE MAIN
LAKE EFFECT BAND OVER THE KEWEENAW PENINSULA (NORTH OF HOUGHTON).
LAKE INDUCED EQUILIBRIUM LEVELS STILL AROUND 7KFT AND MUCH OF THE
CLOUDS IS AT HIGH END OF DGZ OR ABOVE SO WON/T GO TOO HIGH ON
AMOUNTS IN THE LATE MORNING AND INTO THE AFTERNOON...BUT COULD NEAR
LOW END ADVISORY AMOUNTS.
AS FOR SNOW HEADLINES...CANCELLED BARAGA AND SOUTHERN HOUGHTON
EARLY AND WILL ALLOW THE REST OF THE WESTERN AREAS EXPIRE AT 00Z AS
WINDS WILL DIMINISH AND JUST LIGHT SNOW WILL REMAIN. OVER THE
EAST...HAVE KEPT THEM AS IS WITH THE BAD CONDITIONS REPORTED ALONG
M-28 IN ALGER COUNTY...ALTHOUGH MOST LOCATIONS TONIGHT WILL
STRUGGLE TO REACH THE 4 INCH IN 12HR AMOUNTS DUE TO THE SMALLER
FLAKES.
AS FOR THE WIND CHILL HEADLINES...CLOUDS WILL DETERMINE THE LOWS
TONIGHT. UNFORTUNATELY IT COMES DOWN TO THE DIMINISHING LAKE
EFFECT CLOUDS OVER THE WEST AND THEN HIGH CLOUDS STREAMING IN LATE
TONIGHT AHEAD OF THE NEXT WAVE IN THE UPPER TROUGH SLIDING SOUTHEAST
THROUGH THE NORTHERN PLAINS. 12Z GFS/ECMWF ARE THE MOST AGGRESSIVE
WITH THESE HIGH CLOUD...COVERING THE WESTERN HALF OF THE CWA BY
12Z. WITH THE COLD AIR IN PLACE...THINK THAT TEMPS WILL COOL
FAIRLY QUICKLY IN AREAS THAT SKIES CLEAR. THE REGIONAL
GEM...WHICH TRADITIONALLY DOES WELL IN THESE CASES ONLY HAS LOWS
IN THE LOW TEENS BELOW ZERO ALONG THE WISCONSIN BORDER AND SINGLE
DIGITS ELSEWHERE. THIS PROVIDES SOME CONCERN TO THE GOING FORECAST
AND TWEAKED VALUES SLIGHTLY HIGHER. ON THE OTHER SIDE...18Z HRRR/RAP
FORECASTS HAVE LOWS AROUND -20 TO -23 TONIGHT...BUT IN MOST
SITUATIONS THEY ARE TOO LOW. EVEN WITH THE SLIGHT TWEAKS...WIND
CHILL ADVISORY LOOKS GOOD FOR AREAS NEAR THE WISCONSIN BORDER AND
HAVE LEFT IT AS IS. A LITTLE CONCERNED ON LAKE CLOUDS LINGERING
OVER MARQUETTE/BARAGA...BUT LOCATIONS WELL INLAND SHOULD CLEAR OUT
LATE AND ALLOW FOR TEMPS TO FALL. FINALLY...MAY NEED TO MONITOR
MENOMINEE COUNTY...AS GOING FORECAST HAS WIND CHILLS NEARING -25
OVER THE WESTERN REACHES OF THE COUNTY.
THE PREVIOUSLY MENTIONED MID/HIGH CLOUDS WILL MOVE ACROSS THE REST
OF THE CWA DURING THE DAY ON MONDAY AND LEAD TO A FILTERED SUNSHINE
AWAY FROM THE LAKE EFFECT. THERE COULD EVEN BE A FEW SNOW SHOWERS
NEAR IRONWOOD LATE MONDAY AFTERNOON ON THE NORTH EDGE OF THE WAVE
MOVING INTO WISCONSIN ON MONDAY EVENING. HIGHS ON MONDAY WILL BE
15-20 DEGREES BELOW NORMAL AND IN THE SINGLE DIGITS ABOVE ZERO FOR
MOST LOCATIONS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 506 AM EST MON DEC 30 2013
TAKING A LOOK AT THE LARGE SCALE PATTERN...THE UPPER GREAT LAKES
WILL REMAIN DOMINATED BY A TROUGH AT 500MB THROUGH THURSDAY. EVEN
WHEN THE MAIN 500MB LOW DOES EXIT OFF THE NE CANADIAN COAST ON
SATURDAY...ANOTHER LOW SITUATED OVER N CENTRAL CANADA FRIDAY NIGHT
LOOKS TO DIVE ACROSS S CENTRAL CANADA FOR THE LATTER HALF OF THE
WEEKEND. THE ONLY DAYS WHERE THE MERCURY MAY RISE AT OR ABOVE 20F
LOOKS TO BE SATURDAY...AND TO A LESSER EXTENT SUNDAY.
VERY COLD TUESDAY NIGHT...
GIVEN THE COLD AIR LOCKED IN PLACE...ANY MODERATE OR STRONG WINDS
WILL RESULT IN DANGEROUS WIND CHILLS. WIND CHILL VALUES WILL LIKELY
FALL TO THESE DANGEROUS VALUES TUESDAY NIGHT AS STRONG/COLD HIGH
PRESSURE SURGES IN AGAIN FROM THE NW. HOWEVER...WITH WINDS IN THE
COLDEST LOCATIONS LESS THAN OUR 10MPH WIND CHILL ADVISORY/WARNING
CRITERIA...HEADLINES MAY NOT BE POSTED /ALTHOUGH NAM GUIDANCE IS
NEAR/. WE WILL CONTINUE TO HIGHLIGHT THE DANGER HERE...IN THE
HWO...AND WITH SOCIAL MEDIA. THE GFS-MOS CAME IN WITH A FCST LOW OF
-22F AT CHAMPION/VAN RIPER...WITH -17F AT BOTH BERGLAND DAM AND IWD.
CONTINUED LAKE EFFECT SNOW SHOWERS THROUGH THURSDAY...MODERATE TO
HEAVY LES MAY BE ONGOING FOR MAINLY E ALGER/N SCHOOLCRAFT/N LUCE
COUNTIES TUESDAY MORNING. CONTINUED NW FLOW ON COLD AIR AVERAGING
-20 TO -23C AT 850MB WILL BE THE RULE UNTIL APPROX 6Z WEDNESDAY WHEN
THE WINDS BECOME DISRUPTED AS THE SFC TROUGH/LOW STUCK OVER SE LAKE
SUPERIOR WEAKENS AND BECOMES ABSORBED BY THE HIGH SET UP TO OUR NW.
WITH A MESO-LOW LIKELY DEVELOPING IT WILL BE DIFFICULT TO PIN POINT
WHERE AND FOR HOW LONG A DOMINANT BAND OF SNOW MAY
DEVELOP...ANYWHERE FROM NEAR MUNISING TO EAST OF GRAND MARAIS. WILL
WAIT FOR NEAR TERM MODELS TO COME INTO BETTER AGREEMENT BEFORE
REDUCING WATCH TO ADVISORIES...OR HOISTING LES WARNINGS FOR ALGER
AND LUCE COUNTIES.
LES WILL CONTINUE WEDNESDAY INTO THURSDAY...MAINLY ON THE N AND NE
SNOWBELTS. LATEST GUIDANCE INDICATES THE POTENTIAL FOR 3-8IN OF SNOW
ACROSS THE HURON MOUNTAINS FROM LATE WEDNESDAY MORNING THROUGH EARLY
THURSDAY MORNING. HEADLINES MAY BE NEEDED AS THE TIME NEARS.
WARMER AIR THIS WEEKEND...
AS NOTED PREVIOUSLY A SURGE OF RELATIVELY WARM AIR IS FIGURED FOR
THE UPCOMING WEEKEND. THE 30/00Z RUN OF THE GFS INCREASED THE 850MB
WINDS BY APPROX 5-10KTS...WITH THE ECMWF AND GFS SHOWING BETWEEN 40
AND 65KT SW TO W LLJ FROM ROUGHLY 00-18Z SATURDAY. THIS WILL ALLOW
850MB TEMPS TO RISE UP TO -4 TO -8C. AHEAD OF THE SFC LOW SET UP
FROM THE PLAINS STATES THROUGH W ONTARIO...RISING OVERNIGHT TEMPS
WILL BE LIKELY FRIDAY NIGHT INTO SATURDAY. THERE OF COURSE ARE SOME
TIMING DIFFERENCES...WITH THE LOW AND ITS ASSOCIATED COLD FRONT
BEING 6-12HRS QUICK OFF THE LATEST GFS. THE SLOWER ECMWF SOLUTION IS
BACKED UP AT LEAST EARLY SATURDAY BY THE CANADIAN AND DGEX.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1247 AM EST MON DEC 30 2013
IWD...AS THE LLVL FLOW BACKS SLOWLY TOWARD THE WSW THRU THE NGT...
EXPECT LINGERING -SHSN/CLDS TO SHIFT TO THE N...WITH A TREND TOWARD
PREDOMINANT VFR WX. ALTHOUGH SOME LGT SN IN ADVANCE OF ANOTHER
DISTURBANCE MAY ARRIVE LATE MON AFTN...CONDITIONS ARE LIKELY TO
REMAIN VFR AS THIS SYS WL BE MSTR DEPRIVED AND THE SHARPER DYNAMICS
WL REMAIN TO THE S. A WSHFT TOWARD THE WNW IN ITS WAKE MAY BRING A
RETURN OF LK EFFECT -SHSN AND MVFR CONDITIONS DURING THE EVNG.
CMX...WITH A SLOWLY BACKING NW TO W FLOW OF ARCTIC AIR...EXPECT LK
EFFECT -SHSN AND PREDOMINANT IFR VSBYS TO PERSIST THRU THE FCST
PERIOD. SHARPENING LLVL CNVGC COINCIDENT WITH THE PASSAGE OF A
STRONGER DISTURBANCE/ACCOMPANYING LO PRES TROF PASSAGE MAY BRING A
PERIOD OF HEAVIER SHSN/LIFR CONDITIONS THIS EVNG.
SAW...WITH A DOWNSLOPE W WIND FLOW OF DRY ARCTIC AIR...EXPECT VFR
CONDITIONS TO DOMINATE THIS LOCATION THE ENTIRE FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 424 PM EST SUN DEC 29 2013
NORTHWESTERLY WINDS OF 15 TO 25 KNOTS WILL CONTINUE INTO THIS
EVENING BEFORE BACKING TO THE WEST-NORTHWEST LATE TONIGHT INTO
MONDAY. WINDS WILL WEAKEN SLIGHTLY AS THIS OCCURS AND SLOWLY
DIMINISH THE POTENTIAL FOR FREEZING SPRAY OVER THE LAKE BY MONDAY
AFTERNOON. AS THE LINGERING SURFACE TROUGH OVER EASTERN LAKE
SUPERIOR STRENGTHENS ON MONDAY NIGHT AND SHIFTS EAST ON
TUESDAY...NORTHWESTERLY WINDS WILL INCREASE WITH SOME GUSTS TO 30KTS
OVER THE EASTERN LAKE TUESDAY AFTERNOON AND EVENING. THIS WILL ALSO
BRING AN INCREASED OPPORTUNITY FOR HEAVY FREEZING SPRAY THROUGH
TUESDAY NIGHT OVER THE EASTERN HALF OF LAKE SUPERIOR. ALTHOUGH
THERE STILL WILL BE A LINGERING TROUGH OVER EASTERN LAKE SUPERIOR
INTO WEDNESDAY...HIGH PRESSURE BUILDING OVER THE UPPER MISSISSIPPI
VALLEY WILL LEAD TO LIGHTER NORTHWESTERLY WINDS FOR WEDNESDAY AND
THURSDAY...BRINGING AN END TO THE POTENTIAL FOR HEAVY FREEZING
SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY UNTIL 10 AM EST /9 AM CST/ THIS MORNING FOR
MIZ002-004-005-009>011-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ085.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ006-007.
LAKE EFFECT SNOW WATCH FROM THIS EVENING THROUGH TUESDAY EVENING
FOR MIZ006-007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR
LSZ248>251-264-267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR LSZ266.
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
LSZ265.
HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 1 AM EST
WEDNESDAY FOR LSZ264.
HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 4 AM EST
WEDNESDAY FOR LSZ248>250.
HEAVY FREEZING SPRAY WARNING FROM 10 PM EST /9 PM CST/ THIS
EVENING TO 10 PM EST /9 PM CST/ TUESDAY FOR LSZ241>244.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KF
AVIATION...KC
MARINE...SRF
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
956 AM EST MON DEC 30 2013
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD ACROSS THE AREA TODAY AND TUESDAY AS
A COLDER AIRMASS SETTLES INTO THE REGION. A DEVELOPING LOW
PRESSURE SYSTEM WILL MOVE ACROSS THE REGION THROUGH MID WEEK...BRINGING
A BETTER CHANCE OF PRECIPITATION WEDNESDAY NIGHT INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HAVE UPDATED FORECAST TO INCLUDE SCATTERED SNOW SHOWERS WHICH HAVE
DEVELOPED IN A COLD AND SOMEWHAT MOIST NORTHWEST FLOW. RAP MODEL
SOUNDINGS SHOW INSTABILITY AND MOISTURE UP TO ABOUT 4000 FT
AGL...WHICH IS APPARENTLY DEEP ENOUGH TO ALLOW SNOW SHOWER
FORMATION. EXPECT A DUSTING OF ACCUMULATION. LOW LEVEL FLOW WILL
QUICKLY BACK THROUGH LATE MORNING AND AS IT DOES...EXPECT
REMAINING PCPN CHANCES TO TAPER OFF. LOW LEVEL CAA WILL PERSIST
THROUGH THE MORNING BEFORE TAPERING OFF THIS AFTERNOON. EXPECT
HIGHS GENERALLY RANGING FROM THE MID 20S NORTHWEST TO LOWER 30S
SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
A SERIES OF WEAK UPPER LEVEL DISTURBANCES WILL PUSH EAST ACROSS THE
GREAT LAKES TONIGHT INTO WEDNESDAY. THE BEST FORCING WITH THESE
WILL REMAIN OFF TO OUR NORTH...BUT OUR FAR NORTHERN COUNTIES WILL
REMAIN ON THE SOUTHERN FRINGE. WILL THEREFORE INCLUDE SOME 20
POPS FOR LIGHT SNOW ACROSS OUR FAR NORTH LATE TONIGHT AND AGAIN
LATER TUESDAY NIGHT INTO WEDNESDAY. A BETTER CHANCE FOR
PRECIPITATION WILL BEGIN TO DEVELOP THROUGH WEDNESDAY AFTERNOON
ACROSS THE NORTH AS A STRONGER SHORT WAVE APPROACHES THE AREA FROM
THE WEST. TEMPERATURES WILL SLOWLY MODERATE THROUGH MID WEEK.
HIGHS ON TUESDAY WILL BE IN THE UPPER 20S TO MID 30S WITH LOWER 30S
TO LOWER 40S EXPECTED ON WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE MODELS PHASE SRN AND NRN STREAM ENERGY ACROSS THE ERN U.S.
WEDNESDAY NIGHT INTO THURSDAY. AS THIS OCCURS PCPN OVERSPREADS THE
THE FA THURSDAY NIGHT. THE ECMWF REMAINS THE MOST WOUND UP AND
SLOW WITH ITS SFC LOW. WENT WITH A MORE BLENDED SOLUTION. THIS
KEEPS THE N ALL SNOW AND A RAIN/SNOW MIX IN THE S BEFORE CHANGING
OVER TO ALL SNOW.
AS THE LOW PULLS E THURSDAY NIGHT...A STRONG NLY FLOW WILL BRING A
BLAST OF ARCTIC AIR INTO THE REGION. COULD SEE LINGERING SNOW
SHOWERS INTO FRIDAY. HIGH PRESSURE THEN BUILDS IN FRIDAY NIGHT.
BY SUNDAY WAA ISENTROPIC LIFT AHEAD OF A FNT LIFTING OUT OF THE
MIDDLE OF THE COUNTRY WILL SPREAD MORE PCPN INTO THE FA. THICKNESSES
ARE COLD ENUF FOR THE PCPN TO BEGIN AS SNOW...BUT THEN CHANGE TO
RAIN DURING THE DAY ON SUNDAY.
THURSDAY COULD SEE HIGHS DURING THE LATE MORNING HOURS BEFORE
TEMPERATURES FALL AS THE LOW PRESSURE HEADS E. AFTER LOWS FRIDAY
MORNING IN THE SINGLE DIGITS IN THE NW TO THE TEENS ACROSS THE
S...HIGHS WILL ONLY MAKE THE 20S FRIDAY AFTN. SATURDAY SHOULD SEE
A LITTLE WARMUP WITH EVERYONE MAKING THE 30S. SUNDAY COULD SEE SRN
LOCATIONS REACHING THE 40S AGAIN.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
SNOW FLURRIES WILL SPREAD ACROSS THE AREA THIS MORNING UNDER MOIST
NORTHWESTERLY FLOW OFF THE GREAT LAKES WITH MVFR CIGS EXPECTED.
BY THE LATE MORNING...LOW LEVEL FLOW WILL BEGIN TO BACK...WHICH
SHOULD END THE CHANCE FOR FLURRIES. CIGS ARE EXPECTED TO GRADUALLY
RAISE TO VFR DURING THE DAY WITH SOME BREAKS DEVELOPING IN THE
CLOUD COVER AS WELL. WEAK HIGH PRESSURE WILL PASS ACROSS THE
REGION BY THE EARLY EVENING WHICH WILL ALLOW WINDS TO BECOME
LIGHT. OVERNIGHT TONIGHT...A DISTURBANCE PASSING TO THE NORTH OF
THE AREA WILL BRING AN INCREASE IN WESTERLY WINDS UP TO 10 KT AS
WELL AS ADDITIONAL VFR CLOUD COVER. LIGHT SNOW ASSOCIATED WITH
THIS DISTURBANCE IS EXPECTED TO STAY NORTH OF OUR TERMINALS
TONIGHT.
OUTLOOK...MVFR CEILINGS POSSIBLE WEDNESDAY NIGHT INTO THURSDAY
EVENING. MVFR TO IFR VISIBILITIES POSSIBLE THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JGL
NEAR TERM...CONIGLIO/JGL
SHORT TERM...JGL
LONG TERM...SITES
AVIATION...LATTO
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1051 AM EST MON DEC 30 2013
.SYNOPSIS...
A COLD FRONT WILL PASS THROUGH OUR AREA EARLY TODAY...BEFORE
STALLING OVER THE CAROLINAS TOMORROW. A WEAK AREA OF LOW PRESSURE
IS EXPECTED TO FORM ON THIS FRONT...BRINGING LIGHT PRECIPITATION
TO SOUTHSIDE OF VIRGINIA AND THE NORTHERN PIEDMONT OF NORTH
CAROLINA TONIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM EST MONDAY...
RADAR INDICATES LIGHT SNOW SHOWER ACTIVITY MOVING ACROSS CENTRAL
AND SOUTHEAST WEST VIRGINIA THIS MORNING...LIKELY WITH MORE
ACTIVITY OCCURRING BELOW THE RADAR BEAM. REGARDLESS...PHONE CALLS
MADE TO SPOTTERS ACROSS SOUTHEAST WEST VIRGINIA HAVE YIELDED
REPORTS OF ON AND OFF SHOWER ACTIVITY...WITH LITTLE ACCUMULATION.
RADAR DOES INDICATE MORE WIDESPREAD ACTIVITY ACROSS SOUTHERN
OHIO...BUT LATEST RAP AND LOCAL WRF MODELS DO NOT HOLD THIS
ACTIVITY TOGETHER MUCH INTO THE AFTERNOON BEFORE WINDS BACK AHEAD
OF OUR NEXT UPPER LEVEL TROUGH. AS SUCH...HAVE TAILORED
ACCUMULATING SNOWFALL TIGHTLY TO THE UPSLOPE AREAS...MAINLY WITH A
TENTH TO QUARTER INCH ACCUMULATIONS FOR THIS AFTERNOON...WITH
FLURRIES ELSEWHERE.
EXPECT VERY LITTLE WARMING...IF ANY...FOR PORTIONS OF SOUTHEAST
WEST VIRGINIA AND THE MOUNTAIN EMPIRE THIS AFTERNOON AS COLDER AIR
BUILDS IN FROM THE WEST. HOWEVER...WITH THE COLD FRONT MAKING ONLY
SLOW PROGRESS EASTWARD FROM THE BLUE RIDGE THIS MORNING...EXPECT
PORTIONS OF THE SOUTHSIDE AND NORTH CENTRAL NORTH CAROLINA TO WARM
INTO THE UPPER 40S...ESPECIALLY IN AREAS WHERE CLOUDS BREAK OUT
FOR A SHORT WHILE.
A WEAK...BUT FAST MOVING...SOUTHERN STREAM SYSTEM ZIPS THROUGH
NORTH CAROLINA AND FAR SOUTHERN VIRGINIA TONIGHT. GFS AND ECWMF
MODELS DEVELOP LIGHT PRECIP AS STRONG UPPER LEVEL DIVERGENCE
DEVELOPS ALONG WITH SOME MID LEVEL EQUIV POT VORTICITY. FORECAST
SOUNDINGS ARE QUITE DRY BELOW 5KT FEET...SO THERE STILL REMAINS
SOME DOUBT WHETHER ENOUGH SATURATION IN THE LOW LEVELS CAN OCCUR
FOR MEASURABLE PRECIP. CONTINUED SMALL POPS IN THE NORTHERN NC
PIEDMONT AND VA SOUTHSIDE TONIGHT WITH PRECIP MAINLY IN THE FORM
OF RAIN...BUT A FEW FLAKES OF SNOW MIXED IN ARE NOT OUT OF THE
QUESTION. WITH PLENTY OF MID/HIGH LEVEL CLOUDS...LEANED TOWARD THE
WARMER ECMWF FORECAST LOWS TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
AS OF 315 AM EST MONDAY...
AN INTENSE POLAR VORTEX WILL BE ANCHORED OVER THE JAMES BAY REGION
MUCH OF THE MID-WEEK PERIOD WITH BITTERLY COLD AIR LOCKED IN ACROSS
SOUTHERN CANADA INTO NORTHERN NEW ENGLAND. MEANWHILE THE LOCAL
FORECAST AREA WILL REMAIN WELL SOUTH OF THIS STRONG BAROCLINIC ZONE
WITH WESTERLY FLOW ALOFT AND WEAK SURFACE RIDGING AND ONLY MODIFIED
POLAR AIR ACROSS THE REGION. WEATHER SHOULD BE BASICALLY TRANQUIL
WITH TEMPS CLOSE TO OR SLIGHTLY ABOVE LATE DECEMBER CLIMO...THOUGH
SLIGHTLY WARMER ON WEDNESDAY. THURSDAY LOOKS TO BE A TRANSITION DAY
BUT STILL FAIRLY MILD AHEAD OF AN APPROACHING STRONG COLD FRONT.
SIGNIFICANT MODEL DIFFERENCES ARISE AT THIS TIME AS WELL WITH 00Z/30
EURO SHOWING A MUCH DEEPER UPPER TROUGH AND DIGGING SHORTWAVE ALL
THE WAY SOUTH INTO THE LOWER MISS VALLEY AND WINDING UP A DEEPER
SURFACE LOW SUBSTANTIALLY FURTHER SOUTH THAN 00Z/30 GFS OR THE
PREVIOUS EURO WHICH WERE BOTH MUCH LESS AMPLIFIED. FOR THIS PACKAGE
BASICALLY HELD TO MORE OF GFS AND THE 12Z EURO KEEPING WEAKER
SURFACE LOW AND DEFORMATION PRECIP ZONE WELL NORTH OF CWA. AS USUAL
WILL BE AWAITING NEW MODEL RUNS TO ASSESS CONSISTENCY OF SOLUTIONS.
TIMING OF THE COLD FRONT CROSSING THE MOUNTAINS APPEARS TO BE
SOMETIME THURSDAY EVENING BEHIND WHATEVER SURFACE LOW DOES DEVELOP
AND A PIECE OF AT LEAST MODIFIED ARCTIC AIR IS BRIEFLY PULLED SOUTH
INTO THE CENTRAL/SOUTHERN APPALACHIANS BY EARLY FRIDAY MORNING WITH
BOTH EURO/GFS SHOWING H8 TEMPS DOWN TO -16C OVER THE NW CWA BY 12Z
FRIDAY. OF COURSE UPSLOPE SNOW MACHINE WILL BE STARTING UP IN THOSE
FAVORED LOCATIONS.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 345 PM EST SUNDAY...
LONG RANGE MODELS ARE STILL IN THE PROCESS OF RESOLVING HOW THE
ARRIVAL AND PASSAGE OF THE UPPER LEVEL TROUGH WILL AFFECT OUR
WEATHER HEADING INTO THE END OF THE COMING WORKWEEK. BOTH THE GFS
AND ECMWF MODELS ARE SIMILAR IN DEVELOPING A SURFACE LOW OFF OF
THE SOUTHEAST COAST...THEN ADVANCING THE LOW RAPIDLY NORTHEAST.
HOWEVER...THE GFS MODEL IS FASTER IN DEVELOPING THE LOW...MOVING
IT TO UPPER NEW ENGLAND BY THURSDAY EVENING...WHILE THE ECMWF IS 6
TO 12 HOURS SLOWER ALONG A SIMILAR TRACK. BOTH MODELS ALSO DEVELOP
A SECOND LOW PASSING SOUTH OF THE GREAT LAKES...WITH THE
ASSOCIATED COLD FRONT USHERING A SHOT OF ARCTIC AIR SOMETIME
THURSDAY NIGHT. AT THIS POINT...PREFER THE SLOWER ECMWF TIMING OF
THIS SYSTEM AS THE GFS TENDS TO RUN FAST. THE COASTAL LOW APPEARS
FAR ENOUGH EAST THAT WE SHOULD NOT SEE MUCH ASSOCIATED MOISTURE
ACROSS OUR AREA. THE ARRIVAL OF THE ARCTIC AIR ON THE OTHER HAND
WILL USHER IN ANOTHER ROUND OF MOUNTAIN SNOW SHOWERS AND GUSTY
NORTHWEST WINDS.
SNOW SHOWERS WILL DIMINISH FRIDAY AFTERNOON AS HIGH PRESSURE
PASSES OVERHEAD. FRIDAY WILL CERTAINLY BE ON THE CHILLY SIDE AS
THE UPPER TROUGH PASSES OVERHEAD...AND DO NOT EXPECT MUCH OF OUR
AREA TO CLIMB ABOVE FREEZING FOR AFTERNOON HIGHS. HIGH PRESSURE
WILL BECOME WEDGED AGAINST THE EASTERN FACE OF THE APPALACHIANS
FOR SATURDAY. EXPECT SLIGHTLY WARMER TEMPERATURES FOR SATURDAY AS
THE UPPER TROUGH SLIDES EAST.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
AS OF 615 AM EST MONDAY...
VFR CONDITIONS WERE OBSERVED EAST OF THE BLUE RIDGE...WHILE MVFR
TO IFR CONDITIONS WERE FOUND AT KBCB...KLWB AND KBLF. PATCHY AREAS
OF LIGHT RAIN OR DRIZZLE WERE NOTED AHEAD OF A COLD FRONT IN THE
FAR WESTERN PORTION OF OUR AREA...AS THE FRONT PASSES THIS MORNING
AND STRONG COLD AIR ADVECTION FORMS IN ITS WAKE...PRECIPITATION
WILL CHANGE TO -SHSN ALONG THE WESTERN SLOPES AND CONTINUE INTO
THE AFTERNOON. FOR KROA...KLYH AND KDAN...HIGH AND MID LEVEL
CLOUDS WILL INCREASE LATE THIS AFTERNOON AND THIS EVENING AS A
SOUTHERN STREAM SYSTEM APPROACHES. NO MEASURABLE PRECIPITATION IS
EXPECTED WITH THIS SYSTEM.
WINDS ILL BE WNW THROUGH THE TAF VALID PERIOD...AND WILL BE GUSTY
AT TIMES THROUGH 18Z. GUSTS TO 20-20KTS WILL BE POSSIBLE.
AVERAGE.
MEDIUM CONFIDENCE IN CIGS THROUGH THE TAF VALID PERIOD. MEDIUM
CONFIDENCE IN VSBYS BLF AND LWB THROUGH THE TAF VALID
PERIOD...HIGH CONFIDENCE IN VFR VSBYS ELSEWHERE. HIGH CONFIDENCE
IN WIND SPD/DIR THROUGH THE TAF VALID PERIOD.
EXTENDED AVIATION DISCUSSION...A SERIES OF CLIPPER SYSTEMS AND
REINFORCING SHOTS OF ARCTIC AIR ARE EXPECTED IN THE DAYS FOLLOWING
THROUGH NEW YEARS AND THE END OF NEXT WEEK. EACH OF THESE SYSTEMS
WILL BRING MOUNTAIN UPSLOPE -SHSN...AFFECTING PRINCIPALLY BLF AND
LWB.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PH
NEAR TERM...NF/PH
SHORT TERM...PC
LONG TERM...NF
AVIATION...PH/RAB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
516 PM EST MON DEC 30 2013
.UPDATE...
ISSUED AT 512 PM EST MON DEC 30 2013
DESPITE DRY/STABLE NATURE OF ARCTIC AIRMASS SHOWN ON THE 12Z INL
RAOB AND RELATIVELY POOR SN GROWTH PARAMETERS...ISSUED A LK EFFECT
SN WARNING FOR NRN HOUGHTON COUNTY PER SFC REPORTS OF SN FALL RATES
OVER AN INCH/HR UNDER A HEAVY SN BAND SHOWN ON VSBL STLT IMAGERY
STREAMING FM THE BAYFIELD PENINSULA INTO THE N HALF OF HOUGHTON
COUNTY. THIS BAND APPEARS TO BE FOCUSED IN THE LLVL CNVGC BTWN A MORE
NW FLOW OBSVD AT THE MARINE SITES ON ISLE ROYALE AND WSW LAND BREEZE
FLOW TO THE S WITHIN VERY COLD ARCTIC AIRMASS OVER UPR MI. THE 18Z
CNDN MODEL APPEARS TO HAVE THE BEST HANDLE ON THE LOCATION OF THIS
FEATURE AND INDICATES THE FOCUSED LLVL CNVGC/HEAVY SN BAND WL SHIFT
ONLY SLOWLY S THRU THE NGT BEFORE DIMINISHING TOWARD 12Z. GIVEN OBS
AND POTENTIAL LONGER RESIDENCE TIME OF THE HEAVIER SN...OPTED TO GO
WITH WRNG THRU 12Z TUE AS TWO SPOTTERS IN CALUMET HAVE ALREADY
REPORTED 6 INCHES OF SN BTWN NOON AND 4-5PM.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 430 PM EST MON DEC 30 2013
MOST OF UPPER MICHIGAN IS QUIET BUT COLD THIS AFTERNOON...AS THE
AREA IS UNDER LINGERING AFFECTS OF THE HIGH PRESSURE RIDGE THAT
MOVED THROUGH LAST NIGHT INTO THIS MORNING. THIS HAS LED TO WINDS
BACKING TO THE WEST-SOUTHWEST IN THE BOUNDARY LAYER AND FOCUSED THE
REMAINING LAKE EFFECT OVER THE KEWEENAW AND RIGHT ALONG THE
SHORELINE NEAR GRAND MARAIS. CALLS TO THE KEWEENAW THIS AFTERNOON
INDICATE THAT THE FINE FLAKE LES IS STILL IN PLACE. WHILE THIS IS
GOOD AT REDUCING VISIBILITIES...ACCUMULATIONS HAVE BEEN LIGHT AND
UNDER A COUPLE INCHES. OVER THE WEST...TEMPERATURES HAVE STRUGGLE
TO EVEN REACH ZERO DEGREES THIS AFTERNOON...WHICH WILL PAVE THE WAY
FOR ANOTHER NIGHT WILL COLD WIND CHILLS. FARTHER TO THE
SOUTHWEST...A SHORTWAVE IS SLIDING EAST-SOUTHEAST THROUGH MINNESOTA
AT THIS TIME AND IS LEADING TO LIGHT SNOW SHOWERS. THESE -SHSN
SHOULD MISS MUCH OF THE AREA...BUT COULD LEAD TO A FEW FLURRIES
ALONG THE WISCONSIN BORDER.
A WEAK SURFACE TROUGH OVER CENTRAL/SOUTHERN LAKE SUPERIOR AT THIS
TIME WILL BE THE FOCUS FOR THE LAKE EFFECT TONIGHT INTO TUESDAY
MORNING. ALL THE HIGH RESOLUTION MODELS SHOW A MESO-LOW DEVELOPING
OVER THE SOUTHEASTERN LAKE THIS EVENING. A LOOK AT THE MONTREAL
RIVER RADAR THIS AFTERNOON DOESN/T INDICATE ANY CIRCULATION AT THIS
POINT...BUT IT SHOULD BE DEVELOPING THIS EVENING. IN ADDITION...THE
LAKE EFFECT SNOW WILL BE ENHANCED BY A SHORTWAVE MOVING THROUGH THIS
EVENING. THIS WAVE PROVIDES A LITTLE MORE MOISTURE AND MID LEVEL
UPWARD MOTION...ALONG WITH COOLING ALOFT TO WEAKEN THE INVERSION
CURRENTLY AROUND 6-8KFT AND ALLOWS IT TO RISE TO 10-12KFT OVER THE
EASTERN CWA. ALSO...IT HELPS INTENSIFY THE SURFACE TROUGH OR
MESO-LOW OVER THE EASTERN LAKE BEFORE IT SLIDES SOUTHEAST LATE
TONIGHT INTO TUESDAY MORNING (BUT STILL LEAVES A TROUGH OVER THE
EASTERN LAKE). SINCE THIS HAS BEEN SHOWN FOR SEVERAL DAYS
NOW...FAIRLY CONFIDENT ON ITS OCCURRENCE...THE QUESTION COMES DOWN
TO EXACT LOCATION OF THE HEAVIEST BAND AND WHAT THE SNOW RATIOS WILL
BE. LATEST TRENDS IN THE MODELS SHOW A SLIGHTLY LATER ARRIVAL OF
THE STRONG LES BAND ON THE WEST SIDE OF THE MESO-LOW...LIKELY
CLOSER TO 04-06Z. UNFORTUNATELY THE LOCATION IS ALL OVER
THE MAP...WITH SOME HAVE IT HITTING PICTURED ROCKS (AND
NEARLY MUNISING - RAP AND A COUPLE 15Z HOPWRF MEMBERS) WHILE OTHERS
THE FAR NORTHEAST PART OF LUCE COUNTY (2.5 AND 10KM REGIONAL GEMS).
OPTED TO FOCUS ON THE MIDDLE GROUND WHICH WAS SIMILAR TO THE
PREVIOUS FORECAST AND HAVE THE STRONG BAND COME ONSHORE AROUND THE
GRAND MARAIS AREA. PINNING DOWN THIS LOCATION WILL MAKE OR BREAK
SNOWFALL AMOUNTS AND THE POTENTIAL OF REACHING WARNING SNOWFALL
AMOUNTS. ONCE THIS BAND COMES ON SHORE EXPECT A TRANSITION TO A
GENERAL NORTHWEST FLOW LES THROUGH THE DAY ON TUESDAY. WITH A
WEAK SURFACE TROUGH LINGERING OVER THE FAR EASTERN LAKE...MODELS
ARE INDICATING SOME ENHANCED CONVERGENCE TO LEAD TO A STRONGER BAND
AFFECTING NORTHERN LUCE COUNTY...ALTHOUGH THERE WILL BE SOME
WAVERING EXPECTED.
AS FOR SNOW RATIOS AND AMOUNTS...ARCTIC AIR MASS WILL LIKELY BE
MODIFIED SOMEWHAT FROM THE CIRCULATION AND MOISTURE/HEAT FLUX OFF
THE LAKE...WHICH WILL TRY TO PUT SOME OF THE CLOUD INTO THE DGZ.
THUS...WOULD EXPECT SOME HIGHER RATIOS TONIGHT AS THE BAND
COMES ON SHORE AND BEFORE SLIGHTLY COOLER AIR ARRIVES ON
TUESDAY AND TRANSITION BACK TO MORE OF A FINER FLAKE SNOW THAT
WE HAVE SEEN THE LAST 24-48HRS. ON TO AMOUNTS...PREVIOUS FORECAST
WAS RIGHT ON THE EDGE OF BOTH 12/24HR AMOUNTS AND HAVE SIMILAR IF
NOT SLIGHTLY LOWER VALUES FOR THIS FORECAST. THINK THERE WILL BE A
GOOD BURST WITH THAT STRONG BAND TONIGHT INTO TUESDAY MORNING OF 3
TO 7 INCHES. THEN THE TRANSITION TO MORE NORTHWEST WINDS AND
SLIGHTLY LOWER RATIOS SHOULD LEAD TO ANOTHER PERIOD OF 2-6 INCHES
FROM MID MORNING INTO THE EARLY EVENING (BUT LIKELY FOCUSED FARTHER
EAST INTO LUCE COUNTY). THIS IS JUST PUTS THE FORECAST JUST UNDER
BOTH THE 12/24HR WARNING AMOUNTS AND WITH THE UNCERTAINTY IN THE
EXACT LOCATION OF THE HEAVIEST SNOW...WILL ISSUE A STRONGLY WORDED
ADVISORY FOR ALGER/LUCE AND NORTHERN SCHOOLCRAFT FOR TONIGHT INTO
TUESDAY. THAT WAY WE CAN HOPEFULLY GET ONE MORE LOOK AT HIGH RES
RUNS AND IF THERE IS A BETTER HANDLE ON LOCATION AND CONFIDENCE
GROWS ON WARNING AMOUNTS...CAN UPGRADE THIS EVENING OR TONIGHT FOR
THE MORE SPECIFIC LOCATION. WITH ALL OF THE LOCATION
DIFFERENCES...WOULD HATE TO ISSUE A WARNING FOR LUCE AND THEN HAVE
IT STAY MAINLY IN ALGER OR VICE-VERSA.
OVER THE WEST...A SURFACE TROUGH STRETCHED WEST ACROSS SOUTHERN
LAKE SUPERIOR WILL SLOWLY PUSH THE MAIN BAND AFFECTING THE KEWEENAW
SOUTH TONIGHT INTO THE ONTONAGON AND SOUTHERN PORTIONS OF HOUGHTON
COUNTY AREA TONIGHT. AS THIS OCCURS...THE REST OF THE KEWEENAW WILL
TRANSITION TO MORE OF A NW FLOW LAKE EFFECT SCENARIO WHICH WILL
CONTINUE INTO TUESDAY. LESS RESIDENCE TIME OVER WESTERN LAKE
SUPERIOR WILL LIMIT THE ARCTIC AIR MASS MODERATION AND SHOULD KEEP
MOST OF THE CLOUD LAYER ABOVE THE DGZ. THUS...WOULD EXPECT THE
SMALLER SNOW FLAKES AND RATIOS TO CONTINUE THERE AND LIMIT
ACCUMULATIONS. INVERSION HEIGHTS ARE GREATER THAN THE PAST 24HRS
(7-9KFT) WHICH WILL LEAD TO SLIGHTLY STRONGER SHOWERS...BUT ALL OF
THAT CLOUD LAYER WILL BE WELL ABOVE THE DGZ. CURRENT THOUGHT IS
THERE BEING AN INCREASE IN SNOW ACCUMULATION THIS EVENING...BEFORE
COLDER 850MB TEMPS MOVE IN BEHIND THE SHORTWAVE (FALLING TO ALMOST
-26C BY 12Z TUESDAY) AND PUSH ALL OF THE CLOUD ABOVE THE DGZ.
ALTHOUGH TOTAL AMOUNTS OVER THE 24 HOUR PERIOD MAY REACH THE 3-6INCH
RANGE...THINK 12HR AMOUNTS WILL BE HARD PRESSED TO REACH THE 4 INCH
AMOUNT NEEDED FOR A LES ADVISORY.
A COLD START TO THE DAY AND A TIGHTENING SURFACE GRADIENT WITH THE
SURFACE DROPPING SOUTH INTO NORTHERN UPPER MICHIGAN TONIGHT WILL
LEAD TO ANOTHER NIGHT OF VERY COLD WIND CHILLS. THINK THE SCATTERED
HIGH CLOUDS AND SLIGHTLY HIGHER WINDS WILL KEEP TEMPS SLIGHTLY
WARMER THAN LAST NIGHT. BUT THIS WILL ALSO KEEP WIND CHILLS LOW AND
SIMILAR TO LAST NIGHT. THEREFORE...HAVE ISSUED A WIND CHILL
ADVISORY FOR THE SAME LOCATIONS AS LAST NIGHT AND HAVE IT RUNNING
THROUGH LATE TUESDAY MORNING. ONCE AGAIN...TEMPERATURES WILL
STRUGGLE TO REBOUND TOMORROW AND SOME LOCATIONS OUT WEST WILL STAY
IN THE SINGLE DIGITS BELOW ZERO.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 430 PM EST MON DEC 30 2013
MODELS ARE CONSISTENT IN SHOWING THE 500MB CLOSED LOW OVER QUEBEC
WEDNESDAY MOVING OFF INTO THE ATLANTIC THURSDAY. THE GFS /AS USUAL/
IS MORE PROGRESSIVE THAN THE ECWMF WITH THE LONGWAVE TROUGH IN THE
WAKE OF THE LOW...BRINGING THE TROUGH THROUGH THE GREAT LAKES ON
THURSDAY AFTERNOON. THE ECMWF IS SLOWER AND DEEPER WITH THIS
TROUGH...WITH IT BEING MAINLY OVER WI ON THURSDAY AFTERNOON.
GUIDANCE SUGGESTS THAT THE ECMWF HAS BEEN ERRING ON THE DEEPER AND
MORE AMPLIFIED SIDE LATELY...HOWEVER...AND THIS MAY BE THE CASE.
OVERALL WENT MIDDLE OF THE ROAD FOR THE FORECAST AT THIS
POINT...LEANING MORE TOWARDS THE ECMWF. AS FAR AS WHAT THIS MEANS
FOR THE SURFACE...LOW PRESSURE DEVELOPS IN THE CENTRAL PLAINS AND
RIDES NORTHEASTWARD ALONG THE TROUGH...WHICH BRINGS AN INVERTED
SURFACE TROUGH INTO UPPER MI FOR WEDNESDAY NIGHT-THURSDAY AFTERNOON.
TUESDAY NIGHT WINDS REMAIN OUT OF THE WEST NORTHWEST THROUGH
MIDNIGHT...BEFORE GRADUALLY VEERING TO THE NORTH AND EVEN NORTHEAST
AS THE INVERTED TROUGH SHIFTS WESTWARD. THIS MOVES THE HIGHEST POPS
FROM THE FAR NORTHEASTERN PORTIONS OF THE COUNTY TOWARDS MUNISING
THROUGH THE NIGHT. BY WEDNESDAY AFTERNOON...CONVERGENCE FOCUSES
BETWEEN MARQUETTE AND MUNISING...WHICH IS WHERE HIGHEST POPS ARE
SITUATED IN THE GRIDS. WHILE THIS REMAINS THE CASE THROUGH THURSDAY
AFTERNOON...TOTAL ACCUMULATIONS ARE GENERALLY EXPECTED TO BE ON THE
ORDER OF 2 TO 4 INCHES BETWEEN SHOT POINT AND MUNISING. GIVEN THAT
MOST OF THE BANDS ARE SHIFTING FROM WEST-NORTHWEST INTO A MORE
NORTH-NORTHEAST PATTERN THROUGH THE PERIOD...NOT REALLY EXPECTING
ANY ONE LOCATION TO RECEIVE TOO MUCH ACCUMULATION. ALSO...BEYOND
WEDNESDAY MORNING...WINDS AT 850-925MB BECOME SOMEWHAT MISALIGNED
WITH THE SURFACE WINDS...WHICH IS TYPICALLY LESS SUITABLE FOR MORE
STRUCTURED BANDS. THOUGH INVERSION HEIGHTS ARE HIGHER WITH COLDER
850MB TEMPS...GENERALLY UP TO 6-8KFT...THE DGZ IS LOW AND SO EXPECT
THE SAME SMALL SIZED FLAKES-AND LOW ACCUMULATIONS LIKE THOSE
OBSERVED ACROSS UPPER MI ALL WEEK/DESPITE SIMILAR INVERSION HEIGHTS.
THE NAM HINTS AT SOME HIGHER SNOW RATIOS OCCURRING IN THE
EAST...HOWEVER...THE NAM HAS BEEN TRENDING HIGHER THROUGH THIS PAST
WEEK THAN WHAT IS BEING OBSERVED. OVERALL...WEVE SEEN AROUND 18-20:1
RATIOS...AND THIS IS WHAT WAS USED FOR THE FORECAST. USING THE
NAM...THE BEST LIFT COLLOCATED WITH THE DGZ IS BETWEEN 6Z AND 15Z
WEDNESDAY AROUND MUNISING...AND SOME BIGGER FLAKES MAY BE SEEN
DURING THIS TIME. OTHERWISE...EXPECT ACCUMULATIONS TO RANGE FROM 1-3
INCHES NEAR THE LAKE FROM 6Z WEDNESDAY TO 12Z THURSDAY.
FRIDAY INTO SATURDAY LOW PRESSURE SLIDING OVER THE CANADIAN PRAIRIE
WILL SWING WINDS AROUND TO THE SOUTH ACROSS UPPER MI...PUSHING ALL
LAKE EFFECT SNOW BANDS OFF INTO LAKE SUPERIOR. 850MB TEMPS WARM AS
WELL...WITH THE ECMWF HINTING AT -8C TO -10C FOR BOTH DAYS. THE COLD
FRONT PASSES ON SATURDAY NIGHT. THE ARCTIC PUSH BEHIND THIS TROUGH
IS NOT TOO BAD...AS TEMPS 850MB TEMPS ARE SOMEWHAT RESCUED BY A
BRIEF RIDGE MOVING FROM THE NORTHERN PLAINS INTO THE GREAT LAKES
THROUGH SUNDAY AFTERNOON. KEPT BROAD CHANCE POPS ACROSS THE CWA FOR
MUCH OF THE FORECAST AREA THROUGH SATURDAY NIGHT. ON SUNDAY...TEMPS
ARE COLD ENOUGH AND WINDS OUT OF THE WEST-NORTHWEST...SO KEPT CHANCE
POPS CONFINED TO LAKE SUPERIOR.
THE MAIN DIFFERENCES BETWEEN MODELS LIE ON MONDAY...WITH THE ECMWF
AND THE GFS BOTH HINTING AT A VERY COLD ARCTIC PUSH OF AIR SLIDING
THROUGH...WITH 850MB TEMPS AS LOW AS -35C OVER UPPER MI. THOUGH THE
GFS IS NOT QUITE AS LOW...IT HAS 850MB TEMPS AT -25C TO -30C FOR THE
AREA. WILL TREND LOWER WITH TEMPS DURING THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1223 PM EST MON DEC 30 2013
KIWD...A DISTURBANCE MOVING THROUGH WISCONSIN WILL LEAD TO
INCREASING MID LEVEL CLOUDS THIS AFTERNOON. BEHIND THE DISTURBANCE
WINDS WILL SHIFT BACK OFF LAKE SUPERIOR AND LEAD TO LAKE EFFECT
SNOW SHOWERS. HAVE KEPT THINGS AT MVFR AT THIS TIME...SINCE THE
BEST CONVERGENCE AND STRONGEST BAND WILL LIKELY STAY NORTH OF THE
TAF SITE.
KCMX...MAIN QUESTION IS IF THE BAND CURRENTLY OVER THE SITE WILL
MOVE NORTH AND BRING A SHORT PERIOD OF MVFR AND MAYBE VFR
CONDITIONS. BASED OFF CURRENT RADAR/SATELLITE TRENDS...THAT IDEA
SEEMS REASONABLE AND HAVE TRENDED TAF TOWARDS THAT. THAT WILL BE
SHORT LIVED...AS NORTHWEST WINDS WILL PUSH THE BAND BACK SOUTH
EARLY THIS EVENING AND LEAD TO ALTERNATE LANDING MINS FOR MUCH OF
THE REST OF THE PERIOD.
KSAW...VFR CONDITIONS SHOULD PREVAIL THROUGH MUCH OF THE PERIOD
WITH THE DISTURBANCE SOUTH OF THE AREA AND UNFAVORABLE WINDS FOR
LAKE EFFECT. WINDS VEER AROUND TO MORE OF A NORTHWEST DIRECTION
OVERNIGHT INTO TUESDAY MORNING...WHICH WILL BRING CLOUDS ON THE LOW
END OF VFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 430 PM EST MON DEC 30 2013
WEST-NORTHWEST WINDS WILL VEER TO THE NORTHWEST TONIGHT AND BE IN
THE 15-25KT RANGE. THERE COULD BE SOME GUSTS TO 30KTS OVER THE
EASTERN LAKE AS A MESO-LOW DEVELOPS. THESE WINDS WILL CONTINUE TO
PRODUCE SOME AREAS OF HEAVY FREEZING SPRAY AND WILL CONTINUE THE
HEAVY FREEZING SPRAY WARNING INTO WEDNESDAY MORNING OVER THE EAST.
OTHERWISE...LIGHTER WINDS ARE EXPECTED WEDNESDAY AND THURSDAY
BEFORE AN INCREASE OUT OF THE SOUTHWEST ON FRIDAY AND FRIDAY NIGHT.
THERE COULD BE A FEW GALE FORCE GUSTS TO 35KTS WHEN THIS OCCURS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY UNTIL 11 AM EST /10 AM CST/ TUESDAY FOR
MIZ002-004-005-009>011-084.
LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 7 PM EST
TUESDAY FOR MIZ006-007-085.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST TUESDAY FOR MIZ003.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR LSZ266.
HEAVY FREEZING SPRAY WARNING FROM 6 AM TUESDAY TO 4 AM EST
WEDNESDAY FOR LSZ248-265.
HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 1 AM EST
WEDNESDAY FOR LSZ243-244-264.
HEAVY FREEZING SPRAY WARNING FROM 10 PM EST /9 PM CST/ THIS
EVENING TO 10 PM EST /9 PM CST/ TUESDAY FOR LSZ241-242-263.
HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 4 AM EST
WEDNESDAY FOR LSZ249-250.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...SRF
LONG TERM...MCD
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
431 PM EST MON DEC 30 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 430 PM EST MON DEC 30 2013
MOST OF UPPER MICHIGAN IS QUIET BUT COLD THIS AFTERNOON...AS THE
AREA IS UNDER LINGERING AFFECTS OF THE HIGH PRESSURE RIDGE THAT
MOVED THROUGH LAST NIGHT INTO THIS MORNING. THIS HAS LED TO WINDS
BACKING TO THE WEST-SOUTHWEST IN THE BOUNDARY LAYER AND FOCUSED THE
REMAINING LAKE EFFECT OVER THE KEWEENAW AND RIGHT ALONG THE
SHORELINE NEAR GRAND MARAIS. CALLS TO THE KEWEENAW THIS AFTERNOON
INDICATE THAT THE FINE FLAKE LES IS STILL IN PLACE. WHILE THIS IS
GOOD AT REDUCING VISIBILITIES...ACCUMULATIONS HAVE BEEN LIGHT AND
UNDER A COUPLE INCHES. OVER THE WEST...TEMPERATURES HAVE STRUGGLE
TO EVEN REACH ZERO DEGREES THIS AFTERNOON...WHICH WILL PAVE THE WAY
FOR ANOTHER NIGHT WILL COLD WIND CHILLS. FARTHER TO THE
SOUTHWEST...A SHORTWAVE IS SLIDING EAST-SOUTHEAST THROUGH MINNESOTA
AT THIS TIME AND IS LEADING TO LIGHT SNOW SHOWERS. THESE -SHSN
SHOULD MISS MUCH OF THE AREA...BUT COULD LEAD TO A FEW FLURRIES
ALONG THE WISCONSIN BORDER.
A WEAK SURFACE TROUGH OVER CENTRAL/SOUTHERN LAKE SUPERIOR AT THIS
TIME WILL BE THE FOCUS FOR THE LAKE EFFECT TONIGHT INTO TUESDAY
MORNING. ALL THE HIGH RESOLUTION MODELS SHOW A MESO-LOW DEVELOPING
OVER THE SOUTHEASTERN LAKE THIS EVENING. A LOOK AT THE MONTREAL
RIVER RADAR THIS AFTERNOON DOESN/T INDICATE ANY CIRCULATION AT THIS
POINT...BUT IT SHOULD BE DEVELOPING THIS EVENING. IN ADDITION...THE
LAKE EFFECT SNOW WILL BE ENHANCED BY A SHORTWAVE MOVING THROUGH THIS
EVENING. THIS WAVE PROVIDES A LITTLE MORE MOISTURE AND MID LEVEL
UPWARD MOTION...ALONG WITH COOLING ALOFT TO WEAKEN THE INVERSION
CURRENTLY AROUND 6-8KFT AND ALLOWS IT TO RISE TO 10-12KFT OVER THE
EASTERN CWA. ALSO...IT HELPS INTENSIFY THE SURFACE TROUGH OR
MESO-LOW OVER THE EASTERN LAKE BEFORE IT SLIDES SOUTHEAST LATE
TONIGHT INTO TUESDAY MORNING (BUT STILL LEAVES A TROUGH OVER THE
EASTERN LAKE). SINCE THIS HAS BEEN SHOWN FOR SEVERAL DAYS
NOW...FAIRLY CONFIDENT ON ITS OCCURRENCE...THE QUESTION COMES DOWN
TO EXACT LOCATION OF THE HEAVIEST BAND AND WHAT THE SNOW RATIOS WILL
BE. LATEST TRENDS IN THE MODELS SHOW A SLIGHTLY LATER ARRIVAL OF
THE STRONG LES BAND ON THE WEST SIDE OF THE MESO-LOW...LIKELY
CLOSER TO 04-06Z. UNFORTUNATELY THE LOCATION IS ALL OVER
THE MAP...WITH SOME HAVE IT HITTING PICTURED ROCKS (AND
NEARLY MUNISING - RAP AND A COUPLE 15Z HOPWRF MEMBERS) WHILE OTHERS
THE FAR NORTHEAST PART OF LUCE COUNTY (2.5 AND 10KM REGIONAL GEMS).
OPTED TO FOCUS ON THE MIDDLE GROUND WHICH WAS SIMILAR TO THE
PREVIOUS FORECAST AND HAVE THE STRONG BAND COME ONSHORE AROUND THE
GRAND MARAIS AREA. PINNING DOWN THIS LOCATION WILL MAKE OR BREAK
SNOWFALL AMOUNTS AND THE POTENTIAL OF REACHING WARNING SNOWFALL
AMOUNTS. ONCE THIS BAND COMES ON SHORE EXPECT A TRANSITION TO A
GENERAL NORTHWEST FLOW LES THROUGH THE DAY ON TUESDAY. WITH A
WEAK SURFACE TROUGH LINGERING OVER THE FAR EASTERN LAKE...MODELS
ARE INDICATING SOME ENHANCED CONVERGENCE TO LEAD TO A STRONGER BAND
AFFECTING NORTHERN LUCE COUNTY...ALTHOUGH THERE WILL BE SOME
WAVERING EXPECTED.
AS FOR SNOW RATIOS AND AMOUNTS...ARCTIC AIR MASS WILL LIKELY BE
MODIFIED SOMEWHAT FROM THE CIRCULATION AND MOISTURE/HEAT FLUX OFF
THE LAKE...WHICH WILL TRY TO PUT SOME OF THE CLOUD INTO THE DGZ.
THUS...WOULD EXPECT SOME HIGHER RATIOS TONIGHT AS THE BAND
COMES ON SHORE AND BEFORE SLIGHTLY COOLER AIR ARRIVES ON
TUESDAY AND TRANSITION BACK TO MORE OF A FINER FLAKE SNOW THAT
WE HAVE SEEN THE LAST 24-48HRS. ON TO AMOUNTS...PREVIOUS FORECAST
WAS RIGHT ON THE EDGE OF BOTH 12/24HR AMOUNTS AND HAVE SIMILAR IF
NOT SLIGHTLY LOWER VALUES FOR THIS FORECAST. THINK THERE WILL BE A
GOOD BURST WITH THAT STRONG BAND TONIGHT INTO TUESDAY MORNING OF 3
TO 7 INCHES. THEN THE TRANSITION TO MORE NORTHWEST WINDS AND
SLIGHTLY LOWER RATIOS SHOULD LEAD TO ANOTHER PERIOD OF 2-6 INCHES
FROM MID MORNING INTO THE EARLY EVENING (BUT LIKELY FOCUSED FARTHER
EAST INTO LUCE COUNTY). THIS IS JUST PUTS THE FORECAST JUST UNDER
BOTH THE 12/24HR WARNING AMOUNTS AND WITH THE UNCERTAINTY IN THE
EXACT LOCATION OF THE HEAVIEST SNOW...WILL ISSUE A STRONGLY WORDED
ADVISORY FOR ALGER/LUCE AND NORTHERN SCHOOLCRAFT FOR TONIGHT INTO
TUESDAY. THAT WAY WE CAN HOPEFULLY GET ONE MORE LOOK AT HIGH RES
RUNS AND IF THERE IS A BETTER HANDLE ON LOCATION AND CONFIDENCE
GROWS ON WARNING AMOUNTS...CAN UPGRADE THIS EVENING OR TONIGHT FOR
THE MORE SPECIFIC LOCATION. WITH ALL OF THE LOCATION
DIFFERENCES...WOULD HATE TO ISSUE A WARNING FOR LUCE AND THEN HAVE
IT STAY MAINLY IN ALGER OR VICE-VERSA.
OVER THE WEST...A SURFACE TROUGH STRETCHED WEST ACROSS SOUTHERN
LAKE SUPERIOR WILL SLOWLY PUSH THE MAIN BAND AFFECTING THE KEWEENAW
SOUTH TONIGHT INTO THE ONTONAGON AND SOUTHERN PORTIONS OF HOUGHTON
COUNTY AREA TONIGHT. AS THIS OCCURS...THE REST OF THE KEWEENAW WILL
TRANSITION TO MORE OF A NW FLOW LAKE EFFECT SCENARIO WHICH WILL
CONTINUE INTO TUESDAY. LESS RESIDENCE TIME OVER WESTERN LAKE
SUPERIOR WILL LIMIT THE ARCTIC AIR MASS MODERATION AND SHOULD KEEP
MOST OF THE CLOUD LAYER ABOVE THE DGZ. THUS...WOULD EXPECT THE
SMALLER SNOW FLAKES AND RATIOS TO CONTINUE THERE AND LIMIT
ACCUMULATIONS. INVERSION HEIGHTS ARE GREATER THAN THE PAST 24HRS
(7-9KFT) WHICH WILL LEAD TO SLIGHTLY STRONGER SHOWERS...BUT ALL OF
THAT CLOUD LAYER WILL BE WELL ABOVE THE DGZ. CURRENT THOUGHT IS
THERE BEING AN INCREASE IN SNOW ACCUMULATION THIS EVENING...BEFORE
COLDER 850MB TEMPS MOVE IN BEHIND THE SHORTWAVE (FALLING TO ALMOST
-26C BY 12Z TUESDAY) AND PUSH ALL OF THE CLOUD ABOVE THE DGZ.
ALTHOUGH TOTAL AMOUNTS OVER THE 24 HOUR PERIOD MAY REACH THE 3-6INCH
RANGE...THINK 12HR AMOUNTS WILL BE HARD PRESSED TO REACH THE 4 INCH
AMOUNT NEEDED FOR A LES ADVISORY.
A COLD START TO THE DAY AND A TIGHTENING SURFACE GRADIENT WITH THE
SURFACE DROPPING SOUTH INTO NORTHERN UPPER MICHIGAN TONIGHT WILL
LEAD TO ANOTHER NIGHT OF VERY COLD WIND CHILLS. THINK THE SCATTERED
HIGH CLOUDS AND SLIGHTLY HIGHER WINDS WILL KEEP TEMPS SLIGHTLY
WARMER THAN LAST NIGHT. BUT THIS WILL ALSO KEEP WIND CHILLS LOW AND
SIMILAR TO LAST NIGHT. THEREFORE...HAVE ISSUED A WIND CHILL
ADVISORY FOR THE SAME LOCATIONS AS LAST NIGHT AND HAVE IT RUNNING
THROUGH LATE TUESDAY MORNING. ONCE AGAIN...TEMPERATURES WILL
STRUGGLE TO REBOUND TOMORROW AND SOME LOCATIONS OUT WEST WILL STAY
IN THE SINGLE DIGITS BELOW ZERO.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 430 PM EST MON DEC 30 2013
MODELS ARE CONSISTENT IN SHOWING THE 500MB CLOSED LOW OVER QUEBEC
WEDNESDAY MOVING OFF INTO THE ATLANTIC THURSDAY. THE GFS /AS USUAL/
IS MORE PROGRESSIVE THAN THE ECWMF WITH THE LONGWAVE TROUGH IN THE
WAKE OF THE LOW...BRINGING THE TROUGH THROUGH THE GREAT LAKES ON
THURSDAY AFTERNOON. THE ECMWF IS SLOWER AND DEEPER WITH THIS
TROUGH...WITH IT BEING MAINLY OVER WI ON THURSDAY AFTERNOON.
GUIDANCE SUGGESTS THAT THE ECMWF HAS BEEN ERRING ON THE DEEPER AND
MORE AMPLIFIED SIDE LATELY...HOWEVER...AND THIS MAY BE THE CASE.
OVERALL WENT MIDDLE OF THE ROAD FOR THE FORECAST AT THIS
POINT...LEANING MORE TOWARDS THE ECMWF. AS FAR AS WHAT THIS MEANS
FOR THE SURFACE...LOW PRESSURE DEVELOPS IN THE CENTRAL PLAINS AND
RIDES NORTHEASTWARD ALONG THE TROUGH...WHICH BRINGS AN INVERTED
SURFACE TROUGH INTO UPPER MI FOR WEDNESDAY NIGHT-THURSDAY AFTERNOON.
TUESDAY NIGHT WINDS REMAIN OUT OF THE WEST NORTHWEST THROUGH
MIDNIGHT...BEFORE GRADUALLY VEERING TO THE NORTH AND EVEN NORTHEAST
AS THE INVERTED TROUGH SHIFTS WESTWARD. THIS MOVES THE HIGHEST POPS
FROM THE FAR NORTHEASTERN PORTIONS OF THE COUNTY TOWARDS MUNISING
THROUGH THE NIGHT. BY WEDNESDAY AFTERNOON...CONVERGENCE FOCUSES
BETWEEN MARQUETTE AND MUNISING...WHICH IS WHERE HIGHEST POPS ARE
SITUATED IN THE GRIDS. WHILE THIS REMAINS THE CASE THROUGH THURSDAY
AFTERNOON...TOTAL ACCUMULATIONS ARE GENERALLY EXPECTED TO BE ON THE
ORDER OF 2 TO 4 INCHES BETWEEN SHOT POINT AND MUNISING. GIVEN THAT
MOST OF THE BANDS ARE SHIFTING FROM WEST-NORTHWEST INTO A MORE
NORTH-NORTHEAST PATTERN THROUGH THE PERIOD...NOT REALLY EXPECTING
ANY ONE LOCATION TO RECEIVE TOO MUCH ACCUMULATION. ALSO...BEYOND
WEDNESDAY MORNING...WINDS AT 850-925MB BECOME SOMEWHAT MISALIGNED
WITH THE SURFACE WINDS...WHICH IS TYPICALLY LESS SUITABLE FOR MORE
STRUCTURED BANDS. THOUGH INVERSION HEIGHTS ARE HIGHER WITH COLDER
850MB TEMPS...GENERALLY UP TO 6-8KFT...THE DGZ IS LOW AND SO EXPECT
THE SAME SMALL SIZED FLAKES-AND LOW ACCUMULATIONS LIKE THOSE
OBSERVED ACROSS UPPER MI ALL WEEK/DESPITE SIMILAR INVERSION HEIGHTS.
THE NAM HINTS AT SOME HIGHER SNOW RATIOS OCCURRING IN THE
EAST...HOWEVER...THE NAM HAS BEEN TRENDING HIGHER THROUGH THIS PAST
WEEK THAN WHAT IS BEING OBSERVED. OVERALL...WEVE SEEN AROUND 18-20:1
RATIOS...AND THIS IS WHAT WAS USED FOR THE FORECAST. USING THE
NAM...THE BEST LIFT COLLOCATED WITH THE DGZ IS BETWEEN 6Z AND 15Z
WEDNESDAY AROUND MUNISING...AND SOME BIGGER FLAKES MAY BE SEEN
DURING THIS TIME. OTHERWISE...EXPECT ACCUMULATIONS TO RANGE FROM 1-3
INCHES NEAR THE LAKE FROM 6Z WEDNESDAY TO 12Z THURSDAY.
FRIDAY INTO SATURDAY LOW PRESSURE SLIDING OVER THE CANADIAN PRAIRIE
WILL SWING WINDS AROUND TO THE SOUTH ACROSS UPPER MI...PUSHING ALL
LAKE EFFECT SNOW BANDS OFF INTO LAKE SUPERIOR. 850MB TEMPS WARM AS
WELL...WITH THE ECMWF HINTING AT -8C TO -10C FOR BOTH DAYS. THE COLD
FRONT PASSES ON SATURDAY NIGHT. THE ARCTIC PUSH BEHIND THIS TROUGH
IS NOT TOO BAD...AS TEMPS 850MB TEMPS ARE SOMEWHAT RESCUED BY A
BRIEF RIDGE MOVING FROM THE NORTHERN PLAINS INTO THE GREAT LAKES
THROUGH SUNDAY AFTERNOON. KEPT BROAD CHANCE POPS ACROSS THE CWA FOR
MUCH OF THE FORECAST AREA THROUGH SATURDAY NIGHT. ON SUNDAY...TEMPS
ARE COLD ENOUGH AND WINDS OUT OF THE WEST-NORTHWEST...SO KEPT CHANCE
POPS CONFINED TO LAKE SUPERIOR.
THE MAIN DIFFERENCES BETWEEN MODELS LIE ON MONDAY...WITH THE ECMWF
AND THE GFS BOTH HINTING AT A VERY COLD ARCTIC PUSH OF AIR SLIDING
THROUGH...WITH 850MB TEMPS AS LOW AS -35C OVER UPPER MI. THOUGH THE
GFS IS NOT QUITE AS LOW...IT HAS 850MB TEMPS AT -25C TO -30C FOR THE
AREA. WILL TREND LOWER WITH TEMPS DURING THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1223 PM EST MON DEC 30 2013
KIWD...A DISTURBANCE MOVING THROUGH WISCONSIN WILL LEAD TO
INCREASING MID LEVEL CLOUDS THIS AFTERNOON. BEHIND THE DISTURBANCE
WINDS WILL SHIFT BACK OFF LAKE SUPERIOR AND LEAD TO LAKE EFFECT
SNOW SHOWERS. HAVE KEPT THINGS AT MVFR AT THIS TIME...SINCE THE
BEST CONVERGENCE AND STRONGEST BAND WILL LIKELY STAY NORTH OF THE
TAF SITE.
KCMX...MAIN QUESTION IS IF THE BAND CURRENTLY OVER THE SITE WILL
MOVE NORTH AND BRING A SHORT PERIOD OF MVFR AND MAYBE VFR
CONDITIONS. BASED OFF CURRENT RADAR/SATELLITE TRENDS...THAT IDEA
SEEMS REASONABLE AND HAVE TRENDED TAF TOWARDS THAT. THAT WILL BE
SHORT LIVED...AS NORTHWEST WINDS WILL PUSH THE BAND BACK SOUTH
EARLY THIS EVENING AND LEAD TO ALTERNATE LANDING MINS FOR MUCH OF
THE REST OF THE PERIOD.
KSAW...VFR CONDITIONS SHOULD PREVAIL THROUGH MUCH OF THE PERIOD
WITH THE DISTURBANCE SOUTH OF THE AREA AND UNFAVORABLE WINDS FOR
LAKE EFFECT. WINDS VEER AROUND TO MORE OF A NORTHWEST DIRECTION
OVERNIGHT INTO TUESDAY MORNING...WHICH WILL BRING CLOUDS ON THE LOW
END OF VFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 430 PM EST MON DEC 30 2013
WEST-NORTHWEST WINDS WILL VEER TO THE NORTHWEST TONIGHT AND BE IN
THE 15-25KT RANGE. THERE COULD BE SOME GUSTS TO 30KTS OVER THE
EASTERN LAKE AS A MESO-LOW DEVELOPS. THESE WINDS WILL CONTINUE TO
PRODUCE SOME AREAS OF HEAVY FREEZING SPRAY AND WILL CONTINUE THE
HEAVY FREEZING SPRAY WARNING INTO WEDNESDAY MORNING OVER THE EAST.
OTHERWISE...LIGHTER WINDS ARE EXPECTED WEDNESDAY AND THURSDAY
BEFORE AN INCREASE OUT OF THE SOUTHWEST ON FRIDAY AND FRIDAY NIGHT.
THERE COULD BE A FEW GALE FORCE GUSTS TO 35KTS WHEN THIS OCCURS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 7 PM EST
TUESDAY FOR MIZ006-007-085.
WIND CHILL ADVISORY FROM 8 PM EST /7 PM CST/ THIS EVENING TO 11
AM EST /10 AM CST/ TUESDAY FOR MIZ002-004-005-009>011-084.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR LSZ266.
HEAVY FREEZING SPRAY WARNING FROM 6 AM TUESDAY TO 4 AM EST
WEDNESDAY FOR LSZ248-265.
HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 1 AM EST
WEDNESDAY FOR LSZ243-244-264.
HEAVY FREEZING SPRAY WARNING FROM 10 PM EST /9 PM CST/ THIS
EVENING TO 10 PM EST /9 PM CST/ TUESDAY FOR LSZ241-242-263.
HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 4 AM EST
WEDNESDAY FOR LSZ249-250.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...MCD
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
418 PM EST MON DEC 30 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 417 PM EST MON DEC 30 2013
MOST OF UPPER MICHIGAN IS QUIET BUT COLD THIS AFTERNOON...AS THE
AREA IS UNDER LINGERING AFFECTS OF THE HIGH PRESSURE RIDGE THAT
MOVED THROUGH LAST NIGHT INTO THIS MORNING. THIS HAS LED TO WINDS
BACKING TO THE WEST-SOUTHWEST IN THE BOUNDARY LAYER AND FOCUSED THE
REMAINING LAKE EFFECT OVER THE KEWEENAW AND RIGHT ALONG THE
SHORELINE NEAR GRAND MARAIS. CALLS TO THE KEWEENAW THIS AFTERNOON
INDICATE THAT THE FINE FLAKE LES IS STILL IN PLACE. WHILE THIS IS
GOOD AT REDUCING VISIBILITIES...ACCUMULATIONS HAVE BEEN LIGHT AND
UNDER A COUPLE INCHES. OVER THE WEST...TEMPERATURES HAVE STRUGGLE
TO EVEN REACH ZERO DEGREES THIS AFTERNOON...WHICH WILL PAVE THE WAY
FOR ANOTHER NIGHT WILL COLD WIND CHILLS. FARTHER TO THE
SOUTHWEST...A SHORTWAVE IS SLIDING EAST-SOUTHEAST THROUGH MINNESOTA
AT THIS TIME AND IS LEADING TO LIGHT SNOW SHOWERS. THESE -SHSN
SHOULD MISS MUCH OF THE AREA...BUT COULD LEAD TO A FEW FLURRIES
ALONG THE WISCONSIN BORDER.
A WEAK SURFACE TROUGH OVER CENTRAL/SOUTHERN LAKE SUPERIOR AT THIS
TIME WILL BE THE FOCUS FOR THE LAKE EFFECT TONIGHT INTO TUESDAY
MORNING. ALL THE HIGH RESOLUTION MODELS SHOW A MESO-LOW DEVELOPING
OVER THE SOUTHEASTERN LAKE THIS EVENING. A LOOK AT THE MONTREAL
RIVER RADAR THIS AFTERNOON DOESN/T INDICATE ANY CIRCULATION AT THIS
POINT...BUT IT SHOULD BE DEVELOPING THIS EVENING. IN ADDITION...THE
LAKE EFFECT SNOW WILL BE ENHANCED BY A SHORTWAVE MOVING THROUGH THIS
EVENING. THIS WAVE PROVIDES A LITTLE MORE MOISTURE AND MID LEVEL
UPWARD MOTION...ALONG WITH COOLING ALOFT TO WEAKEN THE INVERSION
CURRENTLY AROUND 6-8KFT AND ALLOWS IT TO RISE TO 10-12KFT OVER THE
EASTERN CWA. ALSO...IT HELPS INTENSIFY THE SURFACE TROUGH OR
MESO-LOW OVER THE EASTERN LAKE BEFORE IT SLIDES SOUTHEAST LATE
TONIGHT INTO TUESDAY MORNING (BUT STILL LEAVES A TROUGH OVER THE
EASTERN LAKE). SINCE THIS HAS BEEN SHOWN FOR SEVERAL DAYS
NOW...FAIRLY CONFIDENT ON ITS OCCURRENCE...THE QUESTION COMES DOWN
TO EXACT LOCATION OF THE HEAVIEST BAND AND WHAT THE SNOW RATIOS WILL
BE. LATEST TRENDS IN THE MODELS SHOW A SLIGHTLY LATER ARRIVAL OF
THE STRONG LES BAND ON THE WEST SIDE OF THE MESO-LOW...LIKELY
CLOSER TO 04-06Z. UNFORTUNATELY THE LOCATION IS ALL OVER
THE MAP...WITH SOME HAVE IT HITTING PICTURED ROCKS (AND
NEARLY MUNISING - RAP AND A COUPLE 15Z HOPWRF MEMBERS) WHILE OTHERS
THE FAR NORTHEAST PART OF LUCE COUNTY (2.5 AND 10KM REGIONAL GEMS).
OPTED TO FOCUS ON THE MIDDLE GROUND WHICH WAS SIMILAR TO THE
PREVIOUS FORECAST AND HAVE THE STRONG BAND COME ONSHORE AROUND THE
GRAND MARAIS AREA. PINNING DOWN THIS LOCATION WILL MAKE OR BREAK
SNOWFALL AMOUNTS AND THE POTENTIAL OF REACHING WARNING SNOWFALL
AMOUNTS. ONCE THIS BAND COMES ON SHORE EXPECT A TRANSITION TO A
GENERAL NORTHWEST FLOW LES THROUGH THE DAY ON TUESDAY. WITH A
WEAK SURFACE TROUGH LINGERING OVER THE FAR EASTERN LAKE...MODELS
ARE INDICATING SOME ENHANCED CONVERGENCE TO LEAD TO A STRONGER BAND
AFFECTING NORTHERN LUCE COUNTY...ALTHOUGH THERE WILL BE SOME
WAVERING EXPECTED.
AS FOR SNOW RATIOS AND AMOUNTS...ARCTIC AIR MASS WILL LIKELY BE
MODIFIED SOMEWHAT FROM THE CIRCULATION AND MOISTURE/HEAT FLUX OFF
THE LAKE...WHICH WILL TRY TO PUT SOME OF THE CLOUD INTO THE DGZ.
THUS...WOULD EXPECT SOME HIGHER RATIOS TONIGHT AS THE BAND
COMES ON SHORE AND BEFORE SLIGHTLY COOLER AIR ARRIVES ON
TUESDAY AND TRANSITION BACK TO MORE OF A FINER FLAKE SNOW THAT
WE HAVE SEEN THE LAST 24-48HRS. ON TO AMOUNTS...PREVIOUS FORECAST
WAS RIGHT ON THE EDGE OF BOTH 12/24HR AMOUNTS AND HAVE SIMILAR IF
NOT SLIGHTLY LOWER VALUES FOR THIS FORECAST. THINK THERE WILL BE A
GOOD BURST WITH THAT STRONG BAND TONIGHT INTO TUESDAY MORNING OF 3
TO 7 INCHES. THEN THE TRANSITION TO MORE NORTHWEST WINDS AND
SLIGHTLY LOWER RATIOS SHOULD LEAD TO ANOTHER PERIOD OF 2-6 INCHES
FROM MID MORNING INTO THE EARLY EVENING (BUT LIKELY FOCUSED FARTHER
EAST INTO LUCE COUNTY). THIS IS JUST PUTS THE FORECAST JUST UNDER
BOTH THE 12/24HR WARNING AMOUNTS AND WITH THE UNCERTAINTY IN THE
EXACT LOCATION OF THE HEAVIEST SNOW...WILL ISSUE A STRONGLY WORDED
ADVISORY FOR ALGER/LUCE AND NORTHERN SCHOOLCRAFT FOR TONIGHT INTO
TUESDAY. THAT WAY WE CAN HOPEFULLY GET ONE MORE LOOK AT HIGH RES
RUNS AND IF THERE IS A BETTER HANDLE ON LOCATION AND CONFIDENCE
GROWS ON WARNING AMOUNTS...CAN UPGRADE THIS EVENING OR TONIGHT FOR
THE MORE SPECIFIC LOCATION. WITH ALL OF THE LOCATION
DIFFERENCES...WOULD HATE TO ISSUE A WARNING FOR LUCE AND THEN HAVE
IT STAY MAINLY IN ALGER OR VICE-VERSA.
OVER THE WEST...A SURFACE TROUGH STRETCHED WEST ACROSS SOUTHERN
LAKE SUPERIOR WILL SLOWLY PUSH THE MAIN BAND AFFECTING THE KEWEENAW
SOUTH TONIGHT INTO THE ONTONAGON AND SOUTHERN PORTIONS OF HOUGHTON
COUNTY AREA TONIGHT. AS THIS OCCURS...THE REST OF THE KEWEENAW WILL
TRANSITION TO MORE OF A NW FLOW LAKE EFFECT SCENARIO WHICH WILL
CONTINUE INTO TUESDAY. LESS RESIDENCE TIME OVER WESTERN LAKE
SUPERIOR WILL LIMIT THE ARCTIC AIR MASS MODERATION AND SHOULD KEEP
MOST OF THE CLOUD LAYER ABOVE THE DGZ. THUS...WOULD EXPECT THE
SMALLER SNOW FLAKES AND RATIOS TO CONTINUE THERE AND LIMIT
ACCUMULATIONS. INVERSION HEIGHTS ARE GREATER THAN THE PAST 24HRS
(7-9KFT) WHICH WILL LEAD TO SLIGHTLY STRONGER SHOWERS...BUT ALL OF
THAT CLOUD LAYER WILL BE WELL ABOVE THE DGZ. CURRENT THOUGHT IS
THERE BEING AN INCREASE IN SNOW ACCUMULATION THIS EVENING...BEFORE
COLDER 850MB TEMPS MOVE IN BEHIND THE SHORTWAVE (FALLING TO ALMOST
-26C BY 12Z TUESDAY) AND PUSH ALL OF THE CLOUD ABOVE THE DGZ.
ALTHOUGH TOTAL AMOUNTS OVER THE 24 HOUR PERIOD MAY REACH THE 3-6INCH
RANGE...THINK 12HR AMOUNTS WILL BE HARD PRESSED TO REACH THE 4 INCH
AMOUNT NEEDED FOR A LES ADVISORY.
A COLD START TO THE DAY AND A TIGHTENING SURFACE GRADIENT WITH THE
SURFACE DROPPING SOUTH INTO NORTHERN UPPER MICHIGAN TONIGHT WILL
LEAD TO ANOTHER NIGHT OF VERY COLD WIND CHILLS. THINK THE SCATTERED
HIGH CLOUDS AND SLIGHTLY HIGHER WINDS WILL KEEP TEMPS SLIGHTLY
WARMER THAN LAST NIGHT. BUT THIS WILL ALSO KEEP WIND CHILLS LOW AND
SIMILAR TO LAST NIGHT. THEREFORE...HAVE ISSUED A WIND CHILL
ADVISORY FOR THE SAME LOCATIONS AS LAST NIGHT AND HAVE IT RUNNING
THROUGH LATE TUESDAY MORNING. ONCE AGAIN...TEMPERATURES WILL
STRUGGLE TO REBOUND TOMORROW AND SOME LOCATIONS OUT WEST WILL STAY
IN THE SINGLE DIGITS BELOW ZERO.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 506 AM EST MON DEC 30 2013
TAKING A LOOK AT THE LARGE SCALE PATTERN...THE UPPER GREAT LAKES
WILL REMAIN DOMINATED BY A TROUGH AT 500MB THROUGH THURSDAY. EVEN
WHEN THE MAIN 500MB LOW DOES EXIT OFF THE NE CANADIAN COAST ON
SATURDAY...ANOTHER LOW SITUATED OVER N CENTRAL CANADA FRIDAY NIGHT
LOOKS TO DIVE ACROSS S CENTRAL CANADA FOR THE LATTER HALF OF THE
WEEKEND. THE ONLY DAYS WHERE THE MERCURY MAY RISE AT OR ABOVE 20F
LOOKS TO BE SATURDAY...AND TO A LESSER EXTENT SUNDAY.
VERY COLD TUESDAY NIGHT...
GIVEN THE COLD AIR LOCKED IN PLACE...ANY MODERATE OR STRONG WINDS
WILL RESULT IN DANGEROUS WIND CHILLS. WIND CHILL VALUES WILL LIKELY
FALL TO THESE DANGEROUS VALUES TUESDAY NIGHT AS STRONG/COLD HIGH
PRESSURE SURGES IN AGAIN FROM THE NW. HOWEVER...WITH WINDS IN THE
COLDEST LOCATIONS LESS THAN OUR 10MPH WIND CHILL ADVISORY/WARNING
CRITERIA...HEADLINES MAY NOT BE POSTED /ALTHOUGH NAM GUIDANCE IS
NEAR/. WE WILL CONTINUE TO HIGHLIGHT THE DANGER HERE...IN THE
HWO...AND WITH SOCIAL MEDIA. THE GFS-MOS CAME IN WITH A FCST LOW OF
-22F AT CHAMPION/VAN RIPER...WITH -17F AT BOTH BERGLAND DAM AND IWD.
CONTINUED LAKE EFFECT SNOW SHOWERS THROUGH THURSDAY...MODERATE TO
HEAVY LES MAY BE ONGOING FOR MAINLY E ALGER/N SCHOOLCRAFT/N LUCE
COUNTIES TUESDAY MORNING. CONTINUED NW FLOW ON COLD AIR AVERAGING
-20 TO -23C AT 850MB WILL BE THE RULE UNTIL APPROX 6Z WEDNESDAY WHEN
THE WINDS BECOME DISRUPTED AS THE SFC TROUGH/LOW STUCK OVER SE LAKE
SUPERIOR WEAKENS AND BECOMES ABSORBED BY THE HIGH SET UP TO OUR NW.
WITH A MESO-LOW LIKELY DEVELOPING IT WILL BE DIFFICULT TO PIN POINT
WHERE AND FOR HOW LONG A DOMINANT BAND OF SNOW MAY
DEVELOP...ANYWHERE FROM NEAR MUNISING TO EAST OF GRAND MARAIS. WILL
WAIT FOR NEAR TERM MODELS TO COME INTO BETTER AGREEMENT BEFORE
REDUCING WATCH TO ADVISORIES...OR HOISTING LES WARNINGS FOR ALGER
AND LUCE COUNTIES.
LES WILL CONTINUE WEDNESDAY INTO THURSDAY...MAINLY ON THE N AND NE
SNOWBELTS. LATEST GUIDANCE INDICATES THE POTENTIAL FOR 3-8IN OF SNOW
ACROSS THE HURON MOUNTAINS FROM LATE WEDNESDAY MORNING THROUGH EARLY
THURSDAY MORNING. HEADLINES MAY BE NEEDED AS THE TIME NEARS.
WARMER AIR THIS WEEKEND...
AS NOTED PREVIOUSLY A SURGE OF RELATIVELY WARM AIR IS FIGURED FOR
THE UPCOMING WEEKEND. THE 30/00Z RUN OF THE GFS INCREASED THE 850MB
WINDS BY APPROX 5-10KTS...WITH THE ECMWF AND GFS SHOWING BETWEEN 40
AND 65KT SW TO W LLJ FROM ROUGHLY 00-18Z SATURDAY. THIS WILL ALLOW
850MB TEMPS TO RISE UP TO -4 TO -8C. AHEAD OF THE SFC LOW SET UP
FROM THE PLAINS STATES THROUGH W ONTARIO...RISING OVERNIGHT TEMPS
WILL BE LIKELY FRIDAY NIGHT INTO SATURDAY. THERE OF COURSE ARE SOME
TIMING DIFFERENCES...WITH THE LOW AND ITS ASSOCIATED COLD FRONT
BEING 6-12HRS QUICK OFF THE LATEST GFS. THE SLOWER ECMWF SOLUTION IS
BACKED UP AT LEAST EARLY SATURDAY BY THE CANADIAN AND DGEX.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1223 PM EST MON DEC 30 2013
KIWD...A DISTURBANCE MOVING THROUGH WISCONSIN WILL LEAD TO
INCREASING MID LEVEL CLOUDS THIS AFTERNOON. BEHIND THE DISTURBANCE
WINDS WILL SHIFT BACK OFF LAKE SUPERIOR AND LEAD TO LAKE EFFECT
SNOW SHOWERS. HAVE KEPT THINGS AT MVFR AT THIS TIME...SINCE THE
BEST CONVERGENCE AND STRONGEST BAND WILL LIKELY STAY NORTH OF THE
TAF SITE.
KCMX...MAIN QUESTION IS IF THE BAND CURRENTLY OVER THE SITE WILL
MOVE NORTH AND BRING A SHORT PERIOD OF MVFR AND MAYBE VFR
CONDITIONS. BASED OFF CURRENT RADAR/SATELLITE TRENDS...THAT IDEA
SEEMS REASONABLE AND HAVE TRENDED TAF TOWARDS THAT. THAT WILL BE
SHORT LIVED...AS NORTHWEST WINDS WILL PUSH THE BAND BACK SOUTH
EARLY THIS EVENING AND LEAD TO ALTERNATE LANDING MINS FOR MUCH OF
THE REST OF THE PERIOD.
KSAW...VFR CONDITIONS SHOULD PREVAIL THROUGH MUCH OF THE PERIOD
WITH THE DISTURBANCE SOUTH OF THE AREA AND UNFAVORABLE WINDS FOR
LAKE EFFECT. WINDS VEER AROUND TO MORE OF A NORTHWEST DIRECTION
OVERNIGHT INTO TUESDAY MORNING...WHICH WILL BRING CLOUDS ON THE LOW
END OF VFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 417 PM EST MON DEC 30 2013
WEST-NORTHWEST WINDS WILL VEER TO THE NORTHWEST TONIGHT AND BE IN
THE 15-25KT RANGE. THERE COULD BE SOME GUSTS TO 30KTS OVER THE
EASTERN LAKE AS A MESO-LOW DEVELOPS. THESE WINDS WILL CONTINUE TO
PRODUCE SOME AREAS OF HEAVY FREEZING SPRAY AND WILL CONTINUE THE
HEAVY FREEZING SPRAY WARNING INTO WEDNESDAY MORNING OVER THE EAST.
OTHERWISE...LIGHTER WINDS ARE EXPECTED WEDNESDAY AND THURSDAY
BEFORE AN INCREASE OUT OF THE SOUTHWEST ON FRIDAY AND FRIDAY NIGHT.
THERE COULD BE A FEW GALE FORCE GUSTS TO 35KTS WHEN THIS OCCURS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 7 PM EST
TUESDAY FOR MIZ006-007-085.
WIND CHILL ADVISORY FROM 8 PM EST /7 PM CST/ THIS EVENING TO 11
AM EST /10 AM CST/ TUESDAY FOR MIZ002-004-005-009>011-084.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR LSZ266.
HEAVY FREEZING SPRAY WARNING FROM 6 AM TUESDAY TO 4 AM EST
WEDNESDAY FOR LSZ248-265.
HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 1 AM EST
WEDNESDAY FOR LSZ243-244-264.
HEAVY FREEZING SPRAY WARNING FROM 10 PM EST /9 PM CST/ THIS
EVENING TO 10 PM EST /9 PM CST/ TUESDAY FOR LSZ241-242-263.
HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 4 AM EST
WEDNESDAY FOR LSZ249-250.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KF
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1225 PM EST MON DEC 30 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 540 AM EST MON DEC 30 2013
WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW FROM
CENTRAL CANADA INTO THE NRN GREAT LAKES AROUND THE POLAR VORTEX OVER
HUDSON BAY. ONE IN A SERIES OF CLIPPER SHORTWAVE TROUGHS OVER THE
NRN PLAINS SUPPORTED AN AREA OF LIGHT SNOW OVER THE DAKOTAS. AT THE
SFC...DIMINISHING WNW WINDS PREVAILED ACROSS THE REGION AHEAD
OF THE ARCTIC HIGH PRES RIDGE EXTENDING FROM NRN ALBERTA INTO THE
UPPER MS VALLEY. RADAR INDICATED WEAK MULTIPLE WIND PARALLEL LES
BANDS INTO UPPER MICHIGAN FROM MUNISING EASTWARD. ALTHOUGH 850 MB
TEMPS REMAINED AROUND -23C...INVERSION HEIGHTS AROUND 5K FT AND THE
VERY DRY UPSTREAM AIRMASS HAS LIMITED LES INTENSITY WITH LIGHT
SNOWFALL RATES OF SMALLER SNOWFLAKES. SATELLITE...SFC OBS AND WEB
CAMS ALSO INDICATED PERSIST LIGHT LES INTO THE WEST. IN AREAS WHERE
SKIES HAD CLEARED...INLAND TEMPS HAVE FALLEN OFF TO -10F TO -20F.
EVEN WITH RELATIVELY LIGHT WINDS OF 5 TO 10 MPH...WIND CHILL VALUES
HAD DROPPED INTO THE ADVISORY (-25 TO -30) RANGE.
TODAY...THE MODELS WERE CONSISTENT IN KEEPING THE LIGHT SNOW
ASSOCIATED WITH THE STRONGER FORCING AND ISENTROPIC LIFT ASSOCIATED
WITH THE SHRTWV SOUTH OF UPPER MI. HOWEVER...THE SHRTWV WILL BRING
BACKING WINDS TOWARD WRLY THAT WILL PUSH THE LES OVER THE EAST
OFFSHORE. THE BACKING TREND MAY ALSO RESULT IN ENHANCED LOW LEVEL
CONV IN THE KEWEENAW AND A PERIOD OF SLIGHTLY HEAVIER LES.
OTHERWISE...DIURNAL WARMING SHOULD BRING MODERATING WIND CHILL
VALUES BY MID MORNING. MAINLY JUST HIGH CLOUDS ARE EXPECTED OVER
MUCH OF THE CWA WITH TEMPS CLIMBING TO 0F TO 5F WEST AND CLOSER TO
10F ALONG LAKE SUPERIOR AND EAST.
TONIGHT...WITH A TROUGH ACROSS SRN LAKE SUPERIOR...THE HIGHER RES
MODELS SUGGEST A MESO-LOW MAY DEVELOP OVER THE SE PORTION OF THE LAKE
THAT MAY DROP INTO THE NE CWA EAST OF MUNISING OVERNIGHT AS WINDS
VEER AND INCREASE BEHIND THE SHRTWV. THIS COULD PRODUCE A PERIOD OF
HEAVY SNOW AS STRONGER MOISTURE/HEAT FLUX OFF THE LAKE IN THE CLOSED
CIRCULATION BRING THE DGZ INTO THE CONVECTIVE LAYER WITH POTENTIALLY
INTENSE LES BANDS. HOWEVER...AS EXPECTED WITH MESOSCALE
FEATURES...THERE IS STILL SIGNIFICANT UNCERTAINTY WITH THE
TIMING/LOCATION/DURATION OF ANY HEAVIER SNOW. SO...THE LES WATCH WAS
RETAINED. THE GREATEST ACCUMULATIONS ARE LIKELY FROM PICTURED ROCKS
AND GRAND MARAIS INTO NRN LUCE COUNTY. ALTHOUGH TEMPS ARE NOT
EXPECTED TO DROP AS MUCH TONIGHT WITH GREATER CLOUD COVER...SLIGHTLY
STRONGER WINDS MAY PUSH WIND CHILLS BACK INTO THE ADVISORY RANGE OVER
THE THE INTERIOR WEST HALF.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 506 AM EST MON DEC 30 2013
TAKING A LOOK AT THE LARGE SCALE PATTERN...THE UPPER GREAT LAKES
WILL REMAIN DOMINATED BY A TROUGH AT 500MB THROUGH THURSDAY. EVEN
WHEN THE MAIN 500MB LOW DOES EXIT OFF THE NE CANADIAN COAST ON
SATURDAY...ANOTHER LOW SITUATED OVER N CENTRAL CANADA FRIDAY NIGHT
LOOKS TO DIVE ACROSS S CENTRAL CANADA FOR THE LATTER HALF OF THE
WEEKEND. THE ONLY DAYS WHERE THE MERCURY MAY RISE AT OR ABOVE 20F
LOOKS TO BE SATURDAY...AND TO A LESSER EXTENT SUNDAY.
VERY COLD TUESDAY NIGHT...
GIVEN THE COLD AIR LOCKED IN PLACE...ANY MODERATE OR STRONG WINDS
WILL RESULT IN DANGEROUS WIND CHILLS. WIND CHILL VALUES WILL LIKELY
FALL TO THESE DANGEROUS VALUES TUESDAY NIGHT AS STRONG/COLD HIGH
PRESSURE SURGES IN AGAIN FROM THE NW. HOWEVER...WITH WINDS IN THE
COLDEST LOCATIONS LESS THAN OUR 10MPH WIND CHILL ADVISORY/WARNING
CRITERIA...HEADLINES MAY NOT BE POSTED /ALTHOUGH NAM GUIDANCE IS
NEAR/. WE WILL CONTINUE TO HIGHLIGHT THE DANGER HERE...IN THE
HWO...AND WITH SOCIAL MEDIA. THE GFS-MOS CAME IN WITH A FCST LOW OF
-22F AT CHAMPION/VAN RIPER...WITH -17F AT BOTH BERGLAND DAM AND IWD.
CONTINUED LAKE EFFECT SNOW SHOWERS THROUGH THURSDAY...MODERATE TO
HEAVY LES MAY BE ONGOING FOR MAINLY E ALGER/N SCHOOLCRAFT/N LUCE
COUNTIES TUESDAY MORNING. CONTINUED NW FLOW ON COLD AIR AVERAGING
-20 TO -23C AT 850MB WILL BE THE RULE UNTIL APPROX 6Z WEDNESDAY WHEN
THE WINDS BECOME DISRUPTED AS THE SFC TROUGH/LOW STUCK OVER SE LAKE
SUPERIOR WEAKENS AND BECOMES ABSORBED BY THE HIGH SET UP TO OUR NW.
WITH A MESO-LOW LIKELY DEVELOPING IT WILL BE DIFFICULT TO PIN POINT
WHERE AND FOR HOW LONG A DOMINANT BAND OF SNOW MAY
DEVELOP...ANYWHERE FROM NEAR MUNISING TO EAST OF GRAND MARAIS. WILL
WAIT FOR NEAR TERM MODELS TO COME INTO BETTER AGREEMENT BEFORE
REDUCING WATCH TO ADVISORIES...OR HOISTING LES WARNINGS FOR ALGER
AND LUCE COUNTIES.
LES WILL CONTINUE WEDNESDAY INTO THURSDAY...MAINLY ON THE N AND NE
SNOWBELTS. LATEST GUIDANCE INDICATES THE POTENTIAL FOR 3-8IN OF SNOW
ACROSS THE HURON MOUNTAINS FROM LATE WEDNESDAY MORNING THROUGH EARLY
THURSDAY MORNING. HEADLINES MAY BE NEEDED AS THE TIME NEARS.
WARMER AIR THIS WEEKEND...
AS NOTED PREVIOUSLY A SURGE OF RELATIVELY WARM AIR IS FIGURED FOR
THE UPCOMING WEEKEND. THE 30/00Z RUN OF THE GFS INCREASED THE 850MB
WINDS BY APPROX 5-10KTS...WITH THE ECMWF AND GFS SHOWING BETWEEN 40
AND 65KT SW TO W LLJ FROM ROUGHLY 00-18Z SATURDAY. THIS WILL ALLOW
850MB TEMPS TO RISE UP TO -4 TO -8C. AHEAD OF THE SFC LOW SET UP
FROM THE PLAINS STATES THROUGH W ONTARIO...RISING OVERNIGHT TEMPS
WILL BE LIKELY FRIDAY NIGHT INTO SATURDAY. THERE OF COURSE ARE SOME
TIMING DIFFERENCES...WITH THE LOW AND ITS ASSOCIATED COLD FRONT
BEING 6-12HRS QUICK OFF THE LATEST GFS. THE SLOWER ECMWF SOLUTION IS
BACKED UP AT LEAST EARLY SATURDAY BY THE CANADIAN AND DGEX.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1223 PM EST MON DEC 30 2013
KIWD...A DISTURBANCE MOVING THROUGH WISCONSIN WILL LEAD TO
INCREASING MID LEVEL CLOUDS THIS AFTERNOON. BEHIND THE DISTURBANCE
WINDS WILL SHIFT BACK OFF LAKE SUPERIOR AND LEAD TO LAKE EFFECT
SNOW SHOWERS. HAVE KEPT THINGS AT MVFR AT THIS TIME...SINCE THE
BEST CONVERGENCE AND STRONGEST BAND WILL LIKELY STAY NORTH OF THE
TAF SITE.
KCMX...MAIN QUESTION IS IF THE BAND CURRENTLY OVER THE SITE WILL
MOVE NORTH AND BRING A SHORT PERIOD OF MVFR AND MAYBE VFR
CONDITIONS. BASED OFF CURRENT RADAR/SATELLITE TRENDS...THAT IDEA
SEEMS REASONABLE AND HAVE TRENDED TAF TOWARDS THAT. THAT WILL BE
SHORT LIVED...AS NORTHWEST WINDS WILL PUSH THE BAND BACK SOUTH
EARLY THIS EVENING AND LEAD TO ALTERNATE LANDING MINS FOR MUCH OF
THE REST OF THE PERIOD.
KSAW...VFR CONDITIONS SHOULD PREVAIL THROUGH MUCH OF THE PERIOD
WITH THE DISTURBANCE SOUTH OF THE AREA AND UNFAVORABLE WINDS FOR
LAKE EFFECT. WINDS VEER AROUND TO MORE OF A NORTHWEST DIRECTION
OVERNIGHT INTO TUESDAY MORNING...WHICH WILL BRING CLOUDS ON THE LOW
END OF VFR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 540 AM EST MON DEC 30 2013
WEST NORTHWEST WINDS TO 25 KNOTS ARE EXPECTED TO SLOWLY
DIMINISH...REDUCING THE POTENTIAL FOR FREEZING SPRAY OVER THE LAKE BY
THIS AFTERNOON. AS THE LINGERING SURFACE TROUGH OVER EASTERN LAKE
SUPERIOR STRENGTHENS TONIGHT AND SHIFTS EAST ON
TUESDAY...NORTHWESTERLY WINDS WILL INCREASE WITH SOME GUSTS TO 30KTS
OVER THE EASTERN LAKE TUESDAY AFTERNOON AND EVENING. THIS WILL ALSO
BRING AN INCREASED OPPORTUNITY FOR HEAVY FREEZING SPRAY THROUGH
TUESDAY NIGHT OVER THE EASTERN HALF OF LAKE SUPERIOR. ALTHOUGH THERE
STILL WILL BE A LINGERING TROUGH OVER EASTERN LAKE SUPERIOR INTO
WEDNESDAY...HIGH PRESSURE BUILDING OVER THE UPPER MISSISSIPPI VALLEY
WILL LEAD TO LIGHTER NORTHWESTERLY WINDS FOR WEDNESDAY AND
THURSDAY...BRINGING AN END TO THE POTENTIAL FOR HEAVY FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ006-007.
LAKE EFFECT SNOW WATCH FROM 10 PM EST THIS EVENING THROUGH
TUESDAY EVENING FOR MIZ006-007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR LSZ266.
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
LSZ265.
HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 1 AM EST
WEDNESDAY FOR LSZ264.
HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 4 AM EST
WEDNESDAY FOR LSZ248>250.
HEAVY FREEZING SPRAY WARNING FROM 10 PM EST /9 PM CST/ THIS
EVENING TO 10 PM EST /9 PM CST/ TUESDAY FOR LSZ241>244.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...SRF
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS HASTINGS NE
1153 AM CST MON DEC 30 2013
.UPDATE...
ISSUED AT 1146 AM CST MON DEC 30 2013
UPDATE COMING SHORTLY WITH SOME MINOR TWEAKS. TEMPERATURES
SHOOTING UP PRETTY QUICK WITH WARM FRONTAL/TROF PASSAGE WORKING
EAST ACROSS THE CWFA. HAVE INCREASED TEMPERATURES MOST IN THE
NORTH WITH ORD ALREADY NEAR 40...HOWEVER RAP MODEL SUGGESTS
NEUTRAL/COLD ADVECTION THIS AFTERNOON SO HAVE GONE WITH LOWER
40S AS A HIGHS UP THERE. SLIGHT INCREASES OTHER AREAS AS WELL.
WINDS NEARING ADVISORY IN NORTH CENTRAL NEBRASKA...AND HAVE
INCREASED WIND SPEEDS ACROSS OUR FORECAST AS A RESULT. CLOUDS
ALSO LOOK LESS AND LESS BOTHERSOME. THOUGH A BIT BRISK...TEMPS
10+ DEGREES ABOVE AREN/T TOO BAD FOR DECEMBER 30TH.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 518 AM CST MON DEC 30 2013
UPPER AIR AND SATELLITE DATA SHOW THE REGION UNDER NORTHWESTERLY
FLOW...THANKS TO A LOW PRESSURE SYSTEM OVER THE HUDSON BAY AREA
WITH ITS MAIN TROUGH AXIS EXTENDING SOUTH THROUGH THE CONUS EAST
OF THE MISSOURI RIVER...AND AN AREA OF HIGH PRESSURE SITTING OFF
THE SRN COAST OF CALIFORNIA. A WEAKER PIECE OF SHORTWAVE ENERGY
ASSOCIATED WITH THAT HUDSON BAY LOW IS STARTING TO MAKE ITS WAY
INTO THE REGION FROM THE NW...AND IS CURRENTLY BRINGING PLENTY OF
MID/UPPER LEVEL CLOUD COVER TO THE ENTIRE CWA...AS WELL AS SOME
FLURRIES OR LIGHT SNOW TO NRN PORTIONS OF THE CWA. AT THE
SURFACE...THE CWA SITS BETWEEN HIGH PRESSURE EXTENDING FROM THE
GREAT LAKES TO TX...WITH LOW PRESSURE OVER THE HIGH PLAINS. WINDS
THIS MORNING ARE OUT OF THE SOUTH...AND OCCASIONALLY ON THE GUSTY
SIDE...WHILE WESTERLY WINDS ARE IN PLACE BEHIND A WARM FRONTAL
BOUNDARY OVER WRN NEB.
THE MAIN STORY TODAY LIES WITH THIS DISTURBANCE MOVING
THROUGH...AND THE WARM UP IN TEMPERATURES EXPECTED. THROUGH THE
EARLY/MID MORNING HOURS...WILL CONTINUE TO CARRY THE MENTION OF
SCTRD FLURRIES ACROSS THE NRN HALF OF THE CWA...BUT NO
ACCUMULATION IS EXPECTED WITH ANYTHING THAT DOES FALL. KEPT THE
AFTERNOON HOURS PRECIP FREE...THOUGH THE 4KM WOULD SUGGEST ANOTHER
CHANCE FOR SOME LIGHT PRECIP DIGGING FAR ENOUGH SOUTH TO AFFECT
OUR NORTH AGAIN. ITS BASICALLY THE ONLY MODEL SHOWING THIS SO WILL
KEEP ANY MENTION OUT...BUT WILL BE SOMETHING FOR THE DAY SHIFT TO
MONITOR.
WINDS WILL START TO TURN MORE TO THE SW THEN EVENTUALLY NW BY
MID/LATE MORNING...AND BY MIDDAY THE FRONTAL BOUNDARY IS EXPECTED
TO BE AT LEAST HALFWAY THROUGH THE CWA. W/NW WINDS LOOK TO BE IN
PLACE ACROSS THE ENTIRE CWA BY MID AFTERNOON...WITH SUSTAINED
SPEEDS IN THE 15 TO 25 MPH RANGE AND GUSTS OVER 30 MPH
EXPECTED...WITH THE STRONGER WINDS ACROSS THE W/NWRN HALF OF THE
CWA.
LOOKING AT TEMPERATURES...AS EXPECTED TEMPS OVERNIGHT HAVE BEEN
STEADY/ON THE INCREASE AS WARMER AIR ALOFT IS GRADUALLY ADVECTING
INTO THE AREA...A TREND WHICH WILL CONTINUE INTO THE DAYTIME
HOURS. ALONG WITH THE DOWNSLOPING COMPONENT OF THE W/NWRLY
WINDS...WILL SEE A NICE BUMP UP IN TEMPERATURES COMPARED TO
SUNDAY...WITH SOME LOCATIONS LOOKING TO BE 20+ DEGREES WARMER.
KEPT TEMPS TRENDED TOWARD THE RAP/HRRR...AND THE FORECAST CALLS
FOR LOWER 40S IN THE FAR NRN CWA...WITH NEAR 50 IN THE
ROOKS/PHILLIPS COUNTY KS AREA.
THIS EVENING/TONIGHT REMAINS DRY...WITH SURFACE HIGH PRESSURE
SETTLING INTO THE AREA...BRINGING DIMINISHING WINDS BEFORE
SWITCHING TO THE SOUTH ONCE AGAIN TOWARD 12Z. SHOULD CONTINUE TO
SEE A FEW CLOUDS AROUND THE AREA...WITH OVERNIGHT LOWS EXPECTED TO
FALL INTO THE MID/UPPER TEENS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 518 AM CST MON DEC 30 2013
THE BIGGEST CHALLENGES WILL BE DETERMINING THE TIMING AND
PLACEMENT OF A SURFACE FRONT ON TUESDAY AND HOW FAR SOUTHWEST
COLD AIR MAKES IT BY WEDNESDAY. ALSO A CHALLENGE IS DETERMINING
CHANCE OF PRECIPITATION CHANCES AND TYPE FOR WEDNESDAY.
WE BEGIN THE LONG TERM TUESDAY UNDER NORTHWEST FLOW...BETWEEN A
MID-LEVEL CLOSED LOW OVER SOUTHERN HUDSON BAY AND A CLOSED LOW
OVER WESTERN MEXICO. HIGH TEMPERATURES COULD BE
TRICKY...DEPENDING ON WHERE A SURFACE FRONT ENDS UP TUESDAY. FOR
NOW...IT APPEARS THAT PERHAPS ONLY THE EXTREME NORTHEASTERN CWA
WILL FAIL TO CLIMB TO MILD TEMPERATURES FOR THIS TIME OF
YEAR...JUDGING BY SOLUTIONS WITH THE MOST CONSISTENCY.
A WAVE WILL MOVE INTO THE NORTHWESTERN UNITED STATES WITH AN
ASSOCIATED JET DIVING SOUTH ON THE WEST SIDE OF THE TROUGH. THE
AXIS OF THIS DIGGING TROUGH WILL ENTER THE CENTRAL PLAINS ON
WEDNESDAY...WITH THE TROUGH CROSSING THE CWA NEAR 00Z THURSDAY.
PRECIPITATION COULD START AS EARLY AS LATE TUESDAY NIGHT AND LAST
INTO MOST OF THE DAY ON WEDNESDAY...AT LEAST UNTIL THE TROUGH AXIS
CLEARS THE CWA AT THE END OF THE DAY. THERE ARE SOME MODEL
SOLUTIONS THAT INDICATE THERE MAY BE A WARM NOSE OF AIR ABOVE THE
SURFACE THAT COULD GIVE US SOME POTENTIAL FOR FREEZING RAIN/SLEET
AT THE ONSET OF PRECIPITATION. I AM NOT VERY CONFIDENT WITH THIS
PRECIPITATION TYPE AND HAVE KEPT THIS OUT OF THE FORECAST AS THERE
IS DEFINITELY NOT ANY SORT OF WIDESPREAD AGREEMENT HERE. WAS
RELUCTANT TO GO TOO COLD IN THE SOUTHWEST FOR WEDNESDAY...UNSURE
OF HOW MUCH OF A DOWNSLOPE COMPONENT TO THE WIND WILL HOLD ON
BEFORE THE WIND NUDGES FROM NORTHWEST TO NORTH. ACTUALLY RAISED
TEMPERATURES IN THE SOUTHWESTERN CWA COMPARED TO THE PREVIOUS
FORECAST...DESPITE A COLD FRONT MOVING SOUTH WITH THE MID-UPPER
LEVEL TROUGH ENTERING OUR REALM. I ALSO INCREASED WIND SPEEDS
BEHIND THE FRONT WEDNESDAY...AS THE SURFACE PRESSURE GRADIENT WILL
BE QUITE STRONG. I RAISED CHANCES OF PRECIPITATION FOR WEDNESDAY A
BIT...ESPECIALLY IN THE NORTHEAST AS MODELS ARE A BIT MORE
CONSISTENT WITH GETTING SOME PRECIPITATION...ESPECIALLY IN THE
NORTHEAST. LOWERED LOW TEMPERATURES FOR THURSDAY MORNING A BIT FOR
SOME AREAS AS WIND SPEEDS DIMINISH...ESPECIALLY IN THE WEST. IN
OUR EAST...WIND SPEEDS MIGHT BE UP JUST ENOUGH TO ALLOW OUR FAR
NORTHEASTERN TIP OF THE CWA TO BE IN OR NEAR POTENTIAL WIND CHILL
CONCERNS...BUT QUITE ENOUGH OF AN AREA TO INCLUDE THIS POTENTIAL
FOR WHAT LOOKS VERY MARGINAL AT BEST AS IT IS.
A RIDGE QUICKLY THEN MAKES OUR TEMPERATURES RELATIVELY MILD FOR
THURSDAY AND FRIDAY BEFORE ANOTHER SHOT AIR MOVES IN FOR THE
WEEKEND WITH AN EVEN DEEPER AND LONGER WAVELENGTH THAN THE ONE
COMING MID-WEEK. THERE COULD BE ANOTHER SHOT AT SOME
PRECIPITATION...MOST LIKELY SOME LIGHT SNOW.
AS FOR SNOW AMOUNTS FOR MID-WEEK...NOTHING INDICATES HUGE
NUMBERS...AND NOTHING ABOVE AN INCH AS OF YET AS THERE WILL NOT BE
A LOT OF MOISTURE TO WORK WITH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1146 AM CST MON DEC 30 2013
VFR CONDITIONS ARE FORECAST FOR THE KGRI AREA. SOME MID CLOUDS
EARLY ON IN THE FORECAST WILL SCATTERED OUT BY EVENING. HOWEVER
MVFR CEILINGS APPEAR AS THOUGH THEY WILL RETURN OVERNIGHT WITH
A SOUTH/SOUTHEAST FLOW RETURNING. WINDS WILL BE INCREASING
QUICKLY EARLY THIS AFTERNOON WITH 20-30KT NORTHWEST WINDS
THE REST OF THE AFTERNOON. NO VISIBILITY RESTRICTIONS ARE
EXPECTED...AND WINDS WILL QUICKLY DIE BETWEEN SUNSET AND
MID EVENING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...NOAA/NWS/MORITZ
SHORT TERM...ADO
LONG TERM...HEINLEIN
AVIATION...NOAA/NWS/MORITZ
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1246 PM EST MON DEC 30 2013
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD ACROSS THE AREA TODAY AND TUESDAY AS
A COLDER AIRMASS SETTLES INTO THE REGION. A DEVELOPING LOW
PRESSURE SYSTEM WILL MOVE ACROSS THE REGION THROUGH MID WEEK...BRINGING
A BETTER CHANCE OF PRECIPITATION WEDNESDAY NIGHT INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HAVE UPDATED FORECAST TO INCLUDE SCATTERED SNOW SHOWERS WHICH HAVE
DEVELOPED IN A COLD AND SOMEWHAT MOIST NORTHWEST FLOW. RAP MODEL
SOUNDINGS SHOW INSTABILITY AND MOISTURE UP TO ABOUT 4000 FT
AGL...WHICH IS APPARENTLY DEEP ENOUGH TO ALLOW SNOW SHOWER
FORMATION. EXPECT A DUSTING OF ACCUMULATION. LOW LEVEL FLOW WILL
QUICKLY BACK THROUGH LATE MORNING AND AS IT DOES...EXPECT
REMAINING PCPN CHANCES TO TAPER OFF. LOW LEVEL CAA WILL PERSIST
THROUGH THE MORNING BEFORE TAPERING OFF THIS AFTERNOON. EXPECT
HIGHS GENERALLY RANGING FROM THE MID 20S NORTHWEST TO LOWER 30S
SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
A SERIES OF WEAK UPPER LEVEL DISTURBANCES WILL PUSH EAST ACROSS THE
GREAT LAKES TONIGHT INTO WEDNESDAY. THE BEST FORCING WITH THESE
WILL REMAIN OFF TO OUR NORTH...BUT OUR FAR NORTHERN COUNTIES WILL
REMAIN ON THE SOUTHERN FRINGE. WILL THEREFORE INCLUDE SOME 20
POPS FOR LIGHT SNOW ACROSS OUR FAR NORTH LATE TONIGHT AND AGAIN
LATER TUESDAY NIGHT INTO WEDNESDAY. A BETTER CHANCE FOR
PRECIPITATION WILL BEGIN TO DEVELOP THROUGH WEDNESDAY AFTERNOON
ACROSS THE NORTH AS A STRONGER SHORT WAVE APPROACHES THE AREA FROM
THE WEST. TEMPERATURES WILL SLOWLY MODERATE THROUGH MID WEEK.
HIGHS ON TUESDAY WILL BE IN THE UPPER 20S TO MID 30S WITH LOWER 30S
TO LOWER 40S EXPECTED ON WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE MODELS PHASE SRN AND NRN STREAM ENERGY ACROSS THE ERN U.S.
WEDNESDAY NIGHT INTO THURSDAY. AS THIS OCCURS PCPN OVERSPREADS THE
THE FA THURSDAY NIGHT. THE ECMWF REMAINS THE MOST WOUND UP AND
SLOW WITH ITS SFC LOW. WENT WITH A MORE BLENDED SOLUTION. THIS
KEEPS THE N ALL SNOW AND A RAIN/SNOW MIX IN THE S BEFORE CHANGING
OVER TO ALL SNOW.
AS THE LOW PULLS E THURSDAY NIGHT...A STRONG NLY FLOW WILL BRING A
BLAST OF ARCTIC AIR INTO THE REGION. COULD SEE LINGERING SNOW
SHOWERS INTO FRIDAY. HIGH PRESSURE THEN BUILDS IN FRIDAY NIGHT.
BY SUNDAY WAA ISENTROPIC LIFT AHEAD OF A FNT LIFTING OUT OF THE
MIDDLE OF THE COUNTRY WILL SPREAD MORE PCPN INTO THE FA. THICKNESSES
ARE COLD ENUF FOR THE PCPN TO BEGIN AS SNOW...BUT THEN CHANGE TO
RAIN DURING THE DAY ON SUNDAY.
THURSDAY COULD SEE HIGHS DURING THE LATE MORNING HOURS BEFORE
TEMPERATURES FALL AS THE LOW PRESSURE HEADS E. AFTER LOWS FRIDAY
MORNING IN THE SINGLE DIGITS IN THE NW TO THE TEENS ACROSS THE
S...HIGHS WILL ONLY MAKE THE 20S FRIDAY AFTN. SATURDAY SHOULD SEE
A LITTLE WARMUP WITH EVERYONE MAKING THE 30S. SUNDAY COULD SEE SRN
LOCATIONS REACHING THE 40S AGAIN.
&&
.AVIATION /18Z MONDAY THROUGH FRIDAY/...
MVFR CEILINGS AND SNOW FLURRIES WILL PERSIST FOR A FEW MORE HOURS
UNTIL A WEAK RIDGE BUILDS IN THIS EVENING. VFR IS EXPECTED
TONIGHT. MVFR CEILINGS ASSOCIATED WITH A WEAK TROUGH ARE FORECAST
FOR TUESDAY. VFR SHOULD RETURN TO CVG AFTER 18Z TUESDAY AS ANOTHER
WEAK RIDGE MOVES IN. WINDS SHIFTING TO WEST WILL INCREASE WITH A
TIGHTENING PRESSURE GRADIENT ON TUESDAY...WITH GUSTS OVER 20 KNOTS
LIKELY.
OUTLOOK...MVFR CEILINGS POSSIBLE WEDNESDAY NIGHT INTO THURSDAY
EVENING. MVFR TO IFR VISIBILITIES POSSIBLE THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JGL
NEAR TERM...CONIGLIO/JGL
SHORT TERM...JGL
LONG TERM...SITES
AVIATION...CONIGLIO
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
124 PM EST MON DEC 30 2013
.SYNOPSIS...
A COLD FRONT WILL PASS THROUGH OUR AREA EARLY TODAY...BEFORE
STALLING OVER THE CAROLINAS TOMORROW. A WEAK AREA OF LOW PRESSURE
IS EXPECTED TO FORM ON THIS FRONT...BRINGING LIGHT PRECIPITATION
TO SOUTHSIDE OF VIRGINIA AND THE NORTHERN PIEDMONT OF NORTH
CAROLINA TONIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM EST MONDAY...
RADAR INDICATES LIGHT SNOW SHOWER ACTIVITY MOVING ACROSS CENTRAL
AND SOUTHEAST WEST VIRGINIA THIS MORNING...LIKELY WITH MORE
ACTIVITY OCCURRING BELOW THE RADAR BEAM. REGARDLESS...PHONE CALLS
MADE TO SPOTTERS ACROSS SOUTHEAST WEST VIRGINIA HAVE YIELDED
REPORTS OF ON AND OFF SHOWER ACTIVITY...WITH LITTLE ACCUMULATION.
RADAR DOES INDICATE MORE WIDESPREAD ACTIVITY ACROSS SOUTHERN
OHIO...BUT LATEST RAP AND LOCAL WRF MODELS DO NOT HOLD THIS
ACTIVITY TOGETHER MUCH INTO THE AFTERNOON BEFORE WINDS BACK AHEAD
OF OUR NEXT UPPER LEVEL TROUGH. AS SUCH...HAVE TAILORED
ACCUMULATING SNOWFALL TIGHTLY TO THE UPSLOPE AREAS...MAINLY WITH A
TENTH TO QUARTER INCH ACCUMULATIONS FOR THIS AFTERNOON...WITH
FLURRIES ELSEWHERE.
EXPECT VERY LITTLE WARMING...IF ANY...FOR PORTIONS OF SOUTHEAST
WEST VIRGINIA AND THE MOUNTAIN EMPIRE THIS AFTERNOON AS COLDER AIR
BUILDS IN FROM THE WEST. HOWEVER...WITH THE COLD FRONT MAKING ONLY
SLOW PROGRESS EASTWARD FROM THE BLUE RIDGE THIS MORNING...EXPECT
PORTIONS OF THE SOUTHSIDE AND NORTH CENTRAL NORTH CAROLINA TO WARM
INTO THE UPPER 40S...ESPECIALLY IN AREAS WHERE CLOUDS BREAK OUT
FOR A SHORT WHILE.
A WEAK...BUT FAST MOVING...SOUTHERN STREAM SYSTEM ZIPS THROUGH
NORTH CAROLINA AND FAR SOUTHERN VIRGINIA TONIGHT. GFS AND ECWMF
MODELS DEVELOP LIGHT PRECIP AS STRONG UPPER LEVEL DIVERGENCE
DEVELOPS ALONG WITH SOME MID LEVEL EQUIV POT VORTICITY. FORECAST
SOUNDINGS ARE QUITE DRY BELOW 5KT FEET...SO THERE STILL REMAINS
SOME DOUBT WHETHER ENOUGH SATURATION IN THE LOW LEVELS CAN OCCUR
FOR MEASURABLE PRECIP. CONTINUED SMALL POPS IN THE NORTHERN NC
PIEDMONT AND VA SOUTHSIDE TONIGHT WITH PRECIP MAINLY IN THE FORM
OF RAIN...BUT A FEW FLAKES OF SNOW MIXED IN ARE NOT OUT OF THE
QUESTION. WITH PLENTY OF MID/HIGH LEVEL CLOUDS...LEANED TOWARD THE
WARMER ECMWF FORECAST LOWS TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
AS OF 315 AM EST MONDAY...
AN INTENSE POLAR VORTEX WILL BE ANCHORED OVER THE JAMES BAY REGION
MUCH OF THE MID-WEEK PERIOD WITH BITTERLY COLD AIR LOCKED IN ACROSS
SOUTHERN CANADA INTO NORTHERN NEW ENGLAND. MEANWHILE THE LOCAL
FORECAST AREA WILL REMAIN WELL SOUTH OF THIS STRONG BAROCLINIC ZONE
WITH WESTERLY FLOW ALOFT AND WEAK SURFACE RIDGING AND ONLY MODIFIED
POLAR AIR ACROSS THE REGION. WEATHER SHOULD BE BASICALLY TRANQUIL
WITH TEMPS CLOSE TO OR SLIGHTLY ABOVE LATE DECEMBER CLIMO...THOUGH
SLIGHTLY WARMER ON WEDNESDAY. THURSDAY LOOKS TO BE A TRANSITION DAY
BUT STILL FAIRLY MILD AHEAD OF AN APPROACHING STRONG COLD FRONT.
SIGNIFICANT MODEL DIFFERENCES ARISE AT THIS TIME AS WELL WITH 00Z/30
EURO SHOWING A MUCH DEEPER UPPER TROUGH AND DIGGING SHORTWAVE ALL
THE WAY SOUTH INTO THE LOWER MISS VALLEY AND WINDING UP A DEEPER
SURFACE LOW SUBSTANTIALLY FURTHER SOUTH THAN 00Z/30 GFS OR THE
PREVIOUS EURO WHICH WERE BOTH MUCH LESS AMPLIFIED. FOR THIS PACKAGE
BASICALLY HELD TO MORE OF GFS AND THE 12Z EURO KEEPING WEAKER
SURFACE LOW AND DEFORMATION PRECIP ZONE WELL NORTH OF CWA. AS USUAL
WILL BE AWAITING NEW MODEL RUNS TO ASSESS CONSISTENCY OF SOLUTIONS.
TIMING OF THE COLD FRONT CROSSING THE MOUNTAINS APPEARS TO BE
SOMETIME THURSDAY EVENING BEHIND WHATEVER SURFACE LOW DOES DEVELOP
AND A PIECE OF AT LEAST MODIFIED ARCTIC AIR IS BRIEFLY PULLED SOUTH
INTO THE CENTRAL/SOUTHERN APPALACHIANS BY EARLY FRIDAY MORNING WITH
BOTH EURO/GFS SHOWING H8 TEMPS DOWN TO -16C OVER THE NW CWA BY 12Z
FRIDAY. OF COURSE UPSLOPE SNOW MACHINE WILL BE STARTING UP IN THOSE
FAVORED LOCATIONS.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 345 PM EST SUNDAY...
LONG RANGE MODELS ARE STILL IN THE PROCESS OF RESOLVING HOW THE
ARRIVAL AND PASSAGE OF THE UPPER LEVEL TROUGH WILL AFFECT OUR
WEATHER HEADING INTO THE END OF THE COMING WORKWEEK. BOTH THE GFS
AND ECMWF MODELS ARE SIMILAR IN DEVELOPING A SURFACE LOW OFF OF
THE SOUTHEAST COAST...THEN ADVANCING THE LOW RAPIDLY NORTHEAST.
HOWEVER...THE GFS MODEL IS FASTER IN DEVELOPING THE LOW...MOVING
IT TO UPPER NEW ENGLAND BY THURSDAY EVENING...WHILE THE ECMWF IS 6
TO 12 HOURS SLOWER ALONG A SIMILAR TRACK. BOTH MODELS ALSO DEVELOP
A SECOND LOW PASSING SOUTH OF THE GREAT LAKES...WITH THE
ASSOCIATED COLD FRONT USHERING A SHOT OF ARCTIC AIR SOMETIME
THURSDAY NIGHT. AT THIS POINT...PREFER THE SLOWER ECMWF TIMING OF
THIS SYSTEM AS THE GFS TENDS TO RUN FAST. THE COASTAL LOW APPEARS
FAR ENOUGH EAST THAT WE SHOULD NOT SEE MUCH ASSOCIATED MOISTURE
ACROSS OUR AREA. THE ARRIVAL OF THE ARCTIC AIR ON THE OTHER HAND
WILL USHER IN ANOTHER ROUND OF MOUNTAIN SNOW SHOWERS AND GUSTY
NORTHWEST WINDS.
SNOW SHOWERS WILL DIMINISH FRIDAY AFTERNOON AS HIGH PRESSURE
PASSES OVERHEAD. FRIDAY WILL CERTAINLY BE ON THE CHILLY SIDE AS
THE UPPER TROUGH PASSES OVERHEAD...AND DO NOT EXPECT MUCH OF OUR
AREA TO CLIMB ABOVE FREEZING FOR AFTERNOON HIGHS. HIGH PRESSURE
WILL BECOME WEDGED AGAINST THE EASTERN FACE OF THE APPALACHIANS
FOR SATURDAY. EXPECT SLIGHTLY WARMER TEMPERATURES FOR SATURDAY AS
THE UPPER TROUGH SLIDES EAST.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 115 PM EST MONDAY...
A FEW POCKETS OF SNOW SHOWER ACTIVITY EXIST IN SOUTHEAST WEST
VIRGINIA PER AREA METARS...HOWEVER MUCH OF WHATEVER IS OUT THERE
IS OCCURRING BELOW THE RADAR BEAM. AS SUCH...EXPECT TEMPORARY
REDUCTIONS IN VISIBILITY AT BLF AND OTHER NEARBY LOCAL AIRPORTS AS
THESE SHOWERS PASS OVERHEAD...WITH SNOW SHOWER ACTIVITY
DIMINISHING THROUGH EARLY EVENING.
GUSTY NORTHWESTERLY FLOW WILL ALSO MAINTAIN LOW STRATOCU ACROSS
THE MOUNTAINS THROUGH THE REMAINDER OF THE AFTERNOON...WITH
CEILINGS BELOW 1KFT AT BLF...AND IN THE 2KFT TO 3KFT RANGE AT BCB
AND LWB. CEILINGS INCREASE TO 4KFT OR HIGHER EAST OF THE BLUE
RIDGE. WHILE LOW CLOUDS WILL GRADUALLY DIMINISH THIS EVENING AS
HIGH PRESSURE BUILDS IN...MID AND HIGH CLOUDS WILL PERSIST AS AN
UPPER LEVEL TROUGH APPROACHES FROM THE WEST.
THE UPPER LEVEL TROUGH WILL TRIGGER A LIGHT/BRIEF RAIN AND SNOW
MIX OVERNIGHT MAINLY FOR DAN...POSSIBLY AS FAR NORTH AS ROA AND
LYH. MAY SEE A FEW REDUCTIONS IN VISIBILITY AT DAN AS THE
PRECIPITATION PASSES...BUT DO NOT EXPECT ANY ACCUMULATIONS.
PRECIPITATION IS EXPECTED TO BE EAST OF THE AREA BY SUNRISE
TUESDAY.
SKIES WILL CLEAR FOR TUESDAY AFTERNOON AS THE TROUGH PASSES
EAST...WITH GRADIENT WEST NORTHWEST WINDS PICKING UP DURING LATE
MORNING. EXPECT 20KT TO 25KT GUSTS DURING THE AFTERNOON MOST
LOCATIONS... APPROACHING 30KT AT ROA.
EXTENDED AVIATION DISCUSSION...A SERIES OF CLIPPER SYSTEMS AND
REINFORCING SHOTS OF ARCTIC AIR ARE EXPECTED IN THE DAYS FOLLOWING
THROUGH NEW YEARS AND THE END OF NEXT WEEK. EACH OF THESE SYSTEMS
WILL BRING MOUNTAIN UPSLOPE -SHSN...AFFECTING PRINCIPALLY BLF AND
LWB.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PH
NEAR TERM...NF/PH
SHORT TERM...PC
LONG TERM...NF
AVIATION...NF/PH