Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/15/15
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
237 AM PST FRI FEB 13 2015
.SYNOPSIS...
HIGH PRESSURE OVER CALIFORNIA WILL KEEP DRY CONDITIONS AND ABOVE
NORMAL TEMPERATURES ACROSS THE REGION THROUGH NEXT WEEK. PATCHY FOG
WILL ALSO BE POSSIBLE IN THE SAN JOAQUIN VALLEY EACH NIGHT INTO THE
MORNING HOURS.
&&
.DISCUSSION...PATCHY DENSE FOG IS BEGINNING TO FORM ALONG AND WEST
OF HIGHWAY 99 IN THE SAN JOAQUIN VALLEY. CURRENTLY MADERA AND
HANFORD ARE REPORTING VISIBILITY AT OR LESS THAN ONE HALF MILE.
THE HRRR INDICATES VISIBILITY CONTINUING TO DETERIORATE THROUGH
16Z BEFORE IMPROVING SIGNIFICANTLY AROUND 18Z.
UPPER LEVEL HIGH PRESSURE WILL REMAIN DOMINANT OVER
REGION TODAY INTO THE FIRST PART OF THE WEEKEND RESULTING IN ABOVE
NORMAL DAYTIME HIGH TEMPERATURES...DRY CONDITIONS...AND PATCHY
LATE NIGHT AND EARLY MORNING FOG. TEMPERATURES THIS AFTERNOON WILL
BE SIMILAR TO THOSE OBSERVED YESTERDAY...WITH
VALLEY...DESERT...AND FOOTHILL LOCATIONS IN THE 70S. THESE
TEMPERATURES ARE BETWEEN 10 AND 15 DEGREES ABOVE NORMAL FOR THE
MIDDLE OF FEBRUARY.
THE ENSEMBLE MEAN FORECASTS INDICATE ZONAL FLOW WILL PREVAIL OVER
THE REGION DURING THE SECOND HALF OF THE WEEKEND WITH UPPER LEVEL
NORTHWEST FLOW THROUGH THE MIDDLE OF NEXT WEEK. THIS WILL RESULT
IN A SUBTLE COOLING TREND ACROSS THE AREA. BY
TUESDAY...VALLEY TEMPERATURES WILL RANGE FROM THE UPPER 60S TO MID
70S...STILL WELL ABOVE NORMAL.
BY THE THURSDAY/FRIDAY TIME FRAME OF NEXT WEEK...THE ENSEMBLE MEAN
FORECAST INDICATES THAT UPPER LEVEL HIGH PRESSURE WILL SHIFT
SLIGHTLY EAST OVER THE REGION ONCE AGAIN.
THE CLIMATE PREDICTION CENTERS 6 TO 10 DAY OUTLOOK (VALID FROM
FEBRUARY 18TH THROUGH 22ND) CALLS FOR A HIGH PROBABILITY OF BELOW
NORMAL PRECIPITATION FOR THE ENTIRE REGION AND A HIGH PROBABILITY
OF ABOVE NORMAL TEMPERATURES.
&&
.AVIATION...
IN THE SAN JOAQUIN VALLEY...IFR CONDITIONS WITH AREAS OF LIFR/VLIFR
CEILINGS AND VISIBILITIES UNTIL 18Z FRIDAY. OTHERWISE...MVFR
VISIBILITIES WILL PREVAIL IN HAZE DURING THE NEXT 24 HOURS WITH
AREAS OF IFR/LIFR DEVELOPING AGAIN AFTER 08Z SATURDAY. VFR
CONDITIONS CAN BE EXPECTED ELSEWHERE ACROSS THE CENTRAL CALIFORNIA
INTERIOR DURING THE NEXT 24 HOURS.
&&
.AIR QUALITY ISSUES...
ON FRIDAY FEBRUARY 13 2015... UNHEALTHY FOR SENSITIVE GROUPS IN
KERN COUNTY. FIREPLACE/WOOD STOVE BURNING STATUS IS: NO BURNING
UNLESS REGISTERED IN FRESNO... KERN... KINGS... MADERA... MERCED
AND TULARE COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS HIGH.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.CLIMATE...
RECORDS
SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR
KFAT 02-13 79:1921 43:1903 56:1987 24:1949
KFAT 02-14 79:1924 46:1903 55:1986 25:1949
KFAT 02-15 79:1977 49:1990 58:1902 24:1990
KBFL 02-13 83:1924 49:1949 55:1986 25:1908
KBFL 02-14 78:1991 47:1990 55:1986 21:1903
KBFL 02-15 84:1977 50:1911 56:1982 21:1903
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM PST THIS MORNING CAZ090>092.
&&
$$
PUBLIC...RILEY
AVN/FW...BEAN
SYNOPSIS...RILEY
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
952 PM PST Thu Feb 12 2015
.Synopsis...
Benign weather and mild temperatures will continue into at least
the middle of next week under high pressure. Patchy fog is
possible across southern Sacramento and northern San Joaquin
valleys each morning.
&&
.Discussion...
Afternoon high temperatures were unseasonably warm today reaching
the low to mid 70`s in the valleys...which is 10 to 15 degrees
above normal. As a result many places were at or near records with
Sacramento exec tying the record of 73 degrees and Stockton
breaking the record of 71 after reaching 72 degrees. Forecast
challenge overnight will revolve around fog formation. HRRR and
WRF both showing fog formation Sacramento south...although LAMP and
mos guidance is more bearish on development keeping vis greater
than 3 miles. The situation is further complicated by high
cloudiness spreading overhead...which will reduce fog threat. Feel
the best chances will be Stockton/Modesto San Joaquin valley areas
with likelihood diminishing northward.
.Previous Discussion...
Benign weather through the weekend as pesky ridge keeps choke-hold
on Norcal. Above normal temperatures will continue with daytime
highs in the 60s and 70s, some 5 to 15 degrees above normal.
Patches of high clouds will be present from time to time through the
period as a few weak systems ride the top of the ridge...far to
the north of the local area. Fog development has been limited to
valley locations south of Sacramento the past few
mornings...mainly in northern San Joaquin valley. Suspect this
will be the case again for next few overnights/mornings altho it
may creep toward Sac Metro. Given time of year and full sunshine,
any fog will quickly burn off after sunrise with limited impacts.
CEO
&&
.Extended Discussion (Monday through Thursday)
Dry and warm weather is expected through the extended period
period with morning fog in portions of the southern Sacramento and
northern San Joaquin valleys. Daytime highs will be above normal
but will be gradually trending down from peak warmth from the weekend.
Strong ridging dominates at least through the first half of the
week, but may gradually give way as a shortwave trough attempts
to go through/over late in the week. The GFS, ECMWF and the GEM
all have variations on the method and the timing of this. The ECMWF
brings it rather quickly through and down south along the Sierra
Thursday as something of an inside slider. Most precipitation
would likely stay to the north and east of the forecast area. The
GFS closes off the shortwave into a low and gradually brings it
over northern California Friday through Sunday. The GFS is
certainly the wetter solution of the two, but it has changed quite
a bit from previous runs, so confidence is low at this point. EK
&&
.Aviation...
VFR conditions with SCT-BKN cirrus over interior Norcal. Brief
periods of local MVFR/IFR/LIFR wx conditions due to Stratus/Fog
expected to redevelop from KMYV southward to KMOD 10z-18z Fri.
Light winds across the region. Stratus/fog possible in some of the
higher mountain valleys during the morning hrs next couple of
mornings.
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBANY NY
1003 PM EST SAT FEB 14 2015
.SYNOPSIS...
A STORM WILL RAPIDLY INTENSIFY OFF THE NEW ENGLAND COAST
TONIGHT...BRINGING OCCASIONAL SNOW AND INCREASING WINDS TO THE
REGION. SNOW WILL END SUNDAY MORNING...BUT BITTERLY COLD AIR WILL
RUSH INTO THE REGION ON STRONG NORTHWEST WINDS. THIS WILL RESULT IN
DANGEROUS WIND CHILLS ON THE BACK SIDE OF THIS INTENSE STORM SUNDAY
INTO MONDAY MORNING.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
..WINTER WEATHER ADVISORY FOR SNOW AND BLOWING SNOW..
AS OF 1000 PM EST...SNOW HAS DECREASED CONSIDERABLY ACROSS MUCH
OF THE AREA SUCH THAT IT HAS EITHER ENDED OR BECOME VERY LIGHT.
THE BREAK IS DUE TO BEING BETWEEN SYSTEMS WITH A RATHER COMPLEX
PATTERN EVIDENT. ENERGY IS BEING TRANSFERED TO A DEVELOPING
COASTAL LOW EAST OF NEW JERSEY WITH PRESSURE FALLS NOTED...AND AN
ARCTIC BOUNDARY THAT WAS ADVANCING EASTWARD FROM CENTRAL NEW YORK
HAS STALLED AND IS MERGING WITH AN INVERTED TROUGH EXTENDING
NORTHWARD FROM THE COASTAL LOW. THE STALLING OF THE ARCTIC
BOUNDARY HAS ALSO RESULTED IN SNOW SQUALLS ACROSS CENTRAL NEW YORK
NOT BEING ABLE TO TRANSLATE EASTWARD INTO OUR AREA. THE SQUALLS
ARE EXPECTED TO CONTINUE TO SHRINK IN COVERAGE AND WEAKEN IN
INTENSITY PER THE HRRR AND LOCAL ALY WRF AS THE SLOWLY MOVE EAST.
EXPECTING ENERGY FROM THE UPPER LOW MOVING THROUGH TO ALLOW FOR
OCCASIONAL LIGHT SNOW TO RE-DEVELOP ACROSS THE WESTERN HALF OF THE
AREA...WHILE SOME WRAP-AROUND MOISTURE FROM THE DEEPENING COASTAL
STORM WILL RESULT IN SOME ADDITIONAL LIGHT SNOW FOR AREAS EAST OF
THE HUDSON VALLEY. IN GENERAL THOUGH...MOST OF THE ACCUMULATING
SNOW FOR THE EVENT HAS ALREADY FALLEN...WITH ONLY 1-2 INCHES OF
ADDITIONAL SNOWFALL. OUR STORM TOTAL SNOWFALL MAP ON OUR WEBSITE
IS FROM THE ENTIRE EVENT. BASED ON REPORTS WE HAVE RECEIVED THUS
FAR...GENERALLY LOWER AMOUNTS HAVE FALLEN IN THE HUDSON VALLEY
AROUND 1-4 INCHES...WITH HIGHER AMOUNTS OF 4-6 INCHES IN THE
HIGHER TERRAIN ESPECIALLY EAST OF THE HUDSON VALLEY INTO WESTERN
NEW ENGLAND.
AFTER MIDNIGHT...SURFACE WINDS WILL BECOME NORTH TO NORTHWEST...
AND WIND SPEEDS WILL INCREASE RAPIDLY. THIS WILL RESULT IN TEMPS
DROPPING LATER TONIGHT AND THE STRONGER WINDS WILL ALSO RESULT IN
AREAS OF BLOWING SNOW. WIND CHILL VALUES BY 600 AM WILL LIKELY
DROP TO BETWEEN ZERO AND 30 BELOW (COLDEST READINGS IN THE
ADIRONDACKS). ACTUAL AIR TEMPS WILL FALL TO AROUND 5 BELOW ZERO
OVER THE ADIRONDACKS...TO BETWEEN ZERO AND 15 ABOVE ELSEWHERE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
..WIND CHILL WARNINGS POSTED FOR THE ENTIRE REGION..
THE SNOW SHOULD QUICKLY TAPER OFF SUNDAY MORNING. THE SNOW WILL
END LAST OVER THE NEW ENGLAND ZONES AND THIS MAY NOT OCCUR UNTIL
LATE MORNING. GENERALLY LESS THAN AN INCH SHOULD FALL AFTER 6 AM
SUNDAY. EVEN AFTER THE SNOW ENDS...STRONG NORTHWEST WINDS WILL
CONTINUE TO PRODUCE AREAS OF BLOWING AND DRIFTING SNOW.
TEMPS WILL REMAIN STEADY OR SLOWLY FALL DURING THE DAY ON SUNDAY.
THIS WILL RESULT IN WINDCHILL READING REMAINING IN THE 10 BELOW TO
35 BELOW ZERO RANGE THROUGHOUT THE DAY.
HAVE FORECAST DRY BUT BITTERLY COLD CONDITIONS SUNDAY NIGHT
THROUGH MONDAY NIGHT...WITH MAINLY CLEAR TO PARTLY CLOUDY
CONDITIONS. THE COMBINATION OF AIR TEMPS AND WINDS WILL RESULT IN
THE COLDEST AIRMASS OF THIS WINTER SEASON BY AROUND SUNRISE
MONDAY. THE PERIOD FROM LATE SUNDAY NIGHT INTO EARLY MONDAY
MORNING WILL FEATURE WIND CHILL READINGS IN THE 25 BELOW TO 40
BELOW RANGE IN THE VALLEYS...AND 25 TO 55 BELOW OVER THE HIGHER
TERRAIN. ACTUAL AIR TEMPS WILL REACH LOWS RANGING FROM 20 BELOW TO
30 BELOW OVER THE ADIRONDACKS...AND 5 BELOW TO 20 BELOW ELSEWHERE.
ON MONDAY WINDS WILL SLOWLY DIMINISH...BUT GUSTS OF 20 TO 25 MPH
WILL CONTINUE THROUGH THE AFTERNOON. HIGHS ON MONDAY WILL RANGE
BETWEEN ZERO AND 15 ABOVE...AND WIND CHILL READINGS WILL REMAIN IN
THE 5 BELOW TO 25 BELOW RANGE.
SURFACE WINDS WILL CONTINUE TO DIMINISH MONDAY EVENING...BECOMING
LIGHT AND VARIABLE LATE AT NIGHT. THIS WILL REDUCE THE WIND CHILL
EFFECT...BUT TEMPS WILL STILL BE VERY COLD. LOWS ARE EXPECTED TO
DROP TO BETWEEN 5 BELOW AND 20 BELOW ZERO.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
NO REST FOR THE WEARY. THE EXTENDED OFFERS MORE OF THE
SAME...EXTREME COLD AND AT LEAST A LITTLE MORE SNOW.
TUESDAY WILL ACTUALLY SEE TEMPERATURES MODERATE A LITTLE FROM THOSE
OF MONDAY...AS HIGH PRESSURE GOES OFF SHORE AND ATTEMPTS A SOUTHERLY
FLOW OVER THE REGION. STILL TEENS (TO AROUND 20 SOUTH) WILL DO IT
FOR HIGHS BUT BETTER THAN THE MAINLY SINGLE NUMBERS ON MONDAY.
UNFORTUNATELY AS WE HAVE SEEN MANY TIMES THIS WINTER...A WARM UP
WILL MEAN THE INCREASE OF MOISTURE (CLOUDS) AND POSSIBLY SOME SNOW
AS WELL.
THE GFS STILL TRACKS A SOUTHERN STREAM LOW CLOSE TO THE REGION...BUT
THE MAIN BATCH OF PRECIPITATION STAYING JUST SOUTH AND EAST OF OUR
REGION. HOWEVER...AN UPPER LEVEL TROUGH WORKING THROUGH THE NORTHERN
BRANCH WOULD BRING INCREASING CHANCES OF LIGHT NUISANCE SNOW INTO
OUR REGION LATE TUESDAY INTO WEDNESDAY.
THAT SAID...THERE ARE STILL SEVERAL GAVE MEMBERS THAT WOULD BRING
THE STORM EVEN FURTHER NORTH...WITH THE POTENTIAL FOR A MORE
SIGNIFICANT SNOWFALL....ESPECIALLY FROM ALBANY SOUTH. THIS WOULD BE
THE RESULT OF PHASING BETWEEN THE DISTURBANCE IN THE NORTHERN BRANCH
AND THE SOUTHERN ENERGY SYSTEM. THIS HAS HAPPENED SEVERAL TIMES THIS
WINTER...AND THUS BEARS WATCHING.
IT SHOULD BE POINTED OUT THAT THE 12Z ECWMF CONTINUES TO SUPPRESS
THE STORM EVEN FURTHER SOUTH COMPARED TO THE 12Z GFS AND WOULD IMPLY
IT MISSING UP COMPLETELY AS EVEN THE UPPER LEVEL NORTHERN TROUGH
WOULD BE MUCH FLATTER WITH VERY LITTLE IF ANY SNOW ASSOCIATED IT
WITH IT.
FOR NOW...WILL STAY THE COURSE AND CONTINUE WITH 30 POPS FOR SNOW
FROM ALBANY NORTHWARD...40 POPS SOUTH TUESDAY NIGHT INTO WEDNESDAY.
THE STORM WILL PULL AWAY ON THURSDAY BRINGING ANOTHER SHOT OF VERY
COLD ARCTIC AIR OUR WAY WEDNESDAY NIGHT INTO FRIDAY NIGHT. THE
TRAJECTORY OF THE COLD WILL BE MORE WESTERLY (AS OPPOSED TO
NORTHWESTERLY) WHICH COULD ALLOW FOR SOME LAKE EFFECT SNOW SHOWERS
OFF LAKE ONTARIO...WHICH REMAINS UNFROZEN. THESE LAKE EFFECT SNOW
SHOWERS WOULD IMPACT MAINLY THE ADIRONDACKS BUT THE CATSKILLS AND
EVEN THE GREENS/BERKSHIRES COULD INITIALLY GET SOME UPSLOPE SNOW
SHOWERS BEFORE THE PURE LAKE EFFECT SNOW SHOWERS WOULD KICK IN ON
THURSDAY.
BY SATURDAY...HERE WE GO AGAIN. ANOTHER SOUTHERN STORM MIGHT IMPACT
AT LEAST A PORTION OF OUR REGION. THIS TIME THE ECWMF REMAINS MORE
BULLISH DRIVING LOW PRESSURE UP ALONG THE I-95 CORRIDOR FROM NYC TO
BOSON...INDUCING ENOUGH WARMING ALOFT TO PRODUCE NOT ONLY
SNOW...BUT PERHAPS MIXING ACROSS OUR SOUTHEAST ZONES! THE GFS IS
MUCH FLATTER WITH THIS SYSTEM...BUT BRINGS A NORTHERN STREAM CLIPPER
IN TOWARD OUR REGION WITH MORE LIGHT NUISANCE TYPE SNOW. OF
COURSE...IF ENERGY FROM THE CLIPPER PHASED WITH THE SOUTHERN STREAM
SYSTEM...WE COULD BE LOOKING AT AN IMPRESSIVE SNOWSTORM. THE CHANCES
OF THAT LOOK LOW AT THIS POINT...BUT AGAIN ANOTHER SYSTEM TO KEEP AN
EYE ON. FOR NOW...ONLY MENTION 30 POPS FOR SNOW FOR
SATURDAY...LEANING WITH COLDER TEMPERATURES FROM THE GFS.
STAY TUNED.
SPEAKING OF TEMPERATURES...THEY DO NOT LOOK TO RISE TO ABOVE
FREEZING ANYTIME SOON (UNLESS THE ECWMF IS CORRECT IN WHICH CASE OUR
SOUTHERN ZONES MIGHT APPROACH FREEZING SOUTH NEXT SATURDAY).
AGAIN...IGNORING THIS WARMEST SOLUTION...LOOK FOR HIGHS NEAR 20 ON
WEDNESDAY...TEENS SOUTH TO NEAR ZERO NORTH THURSDAY...TEENS
FRIDAY...UPPER TEENS NORTH TO MID 20S SOUTH SATURDAY.
LOWS WILL BE 5 TO 15 BELOW ZERO TUESDAY MORNING...SINGLE NUMBERS
WEDNESDAY...ZERO TO 10 BELOW THURSDAY MORNING...5 TO 20 BELOW FRIDAY
MORNING AND 5 ABOVE TO ABOUT 5 BELOW ZERO SATURDAY MORNING.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
SNOW CONTINUES TO FALL ACROSS THE TERMINALS THIS EVENING WITH
WIDESPREAD IFR CONDITIONS. SNOW EXPECTED TO BECOME MORE
INTERMITTENT LATER THIS EVENING AND OVERNIGHT...AS LOW PRESSURE
STARTS TO TRANSFER ITS ENERGY TO THE COAST. SO SOME MVFR
CONDITIONS MAY OCCUR WITH SNOW BECOMING LIGHTER.
AFTER MIDNIGHT...WINDS WILL START TO INCREASE AS THE COASTAL LOW
INTENSIFIES. THIS WILL RESULT IN BLOWING SNOW TO DEVELOP AT THE
TERMINALS DESPITE SNOW ENDING BY AROUND SUNRISE SUNDAY. BLOWING
SNOW WILL CONTINUE THROUGH THE MORNING WITH SOME POSSIBLE
MVFR RESTRICTIONS. OTHERWISE VFR CONDITIONS WILL PREVAIL.
WINDS WILL SHIFT TO THE N-NW AND INCREASE TO 15-20 KTS WITH GUSTS
OF 25-35 KTS BY SUNDAY MORNING. WINDS WILL REMAIN GUSTY THROUGHOUT
THE DAYLIGHT HOURS BEFORE ONLY SLIGHTLY DECREASING SUNDAY NIGHT.
OUTLOOK...
SUN NIGHT-MON NIGHT: NO OPERATIONAL IMPACT. NO SIG WEATHER.
TUE-WED: MODERATE OPERATIONAL IMPACT. CHC SN.
THU: NO OPERATIONAL IMPACT. NO SIG WEATHER.
&&
.HYDROLOGY...
MUCH BELOW NORMAL TEMPERATURES WILL BE THE GENERAL RULE WHICH
WILL ALLOW ICE TO CONTINUE TO THICKEN ON RIVERS...STREAMS
CREEKS...LAKES AND OTHER BODIES OF WATER. SOME GAGES WILL
EXPERIENCE MORE ICE AFFECTS THROUGH THE WEEKEND.
A ROUND OF LIGHT TO MODERATE SNOWFALL THROUGH SUNDAY MORNING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.CLIMATE...
GIVEN THE BITTERLY COLD TEMPERATURES ALOFT...WE LOOKED AT
CLIMATOLOGY FOR THE 850MB LEVEL. THE COLDEST EVER OBSERVED ON OUR
UPPER AIR SOUNDINGS WAS -30C. PER NCEP MODEL SUITE...THE LOWEST
VALUES AT UPPER AIR RELEASE TIMES /00Z/12Z/ ARE FORECAST TO BE
INTO THE NEGATIVE MID 20S C ON 00Z MON.
SURFACE TEMPERATURES...
RECORD LOW TEMPERATURES FOR MONDAY FEBRUARY 16TH:
LOCATIONTEMPYEAR
ALBANY-20F1943
GLENS FALLS-24F2004
POUGHKEEPSIE-3 F1963
BENNINGTON -13F2004
PITTSFIELD-26F1943
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 10 AM EST SUNDAY FOR CTZ001-013.
WIND CHILL WARNING FROM 10 AM SUNDAY TO NOON EST MONDAY FOR
CTZ001-013.
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST SUNDAY FOR NYZ032-033-
038>043-047>054-058>061-063>066-082>084.
WIND CHILL WARNING FROM 10 AM SUNDAY TO NOON EST MONDAY FOR
NYZ032-033-038>043-047>054-058>061-063>066-082>084.
MA...WINTER WEATHER ADVISORY UNTIL 10 AM EST SUNDAY FOR MAZ001-025.
WIND CHILL WARNING FROM 10 AM SUNDAY TO NOON EST MONDAY FOR
MAZ001-025.
VT...WINTER WEATHER ADVISORY UNTIL 10 AM EST SUNDAY FOR VTZ013>015.
WIND CHILL WARNING FROM 10 AM SUNDAY TO NOON EST MONDAY FOR
VTZ013>015.
&&
$$
SYNOPSIS...GJM
NEAR TERM...GJM/JPV
SHORT TERM...GJM
LONG TERM...HWJIV
AVIATION...JPV
HYDROLOGY...BGM
CLIMATE...BGM
AREA FORECAST DISCUSSION
NWS TAUNTON MA
653 PM EST SAT FEB 14 2015
.SYNOPSIS...
A POWERFUL OFFSHORE STORM WILL RAPIDLY DEVELOP TONIGHT THROUGH
SUNDAY. THERE WILL BE A PERIOD OF BLIZZARD CONDITIONS ACROSS
COASTAL COMMUNITIES SUNDAY MORNING...ALONG WITH HURRICANE FORCE
WIND GUSTS ACROSS THE OUTER CAPE AND NANTUCKET. EXCEPTIONALLY
COLD AIR...THE COLDEST OF THE SEASON...FOLLOWS LATE SUNDAY INTO
TUESDAY MORNING. ANOTHER STORM SYSTEM IS EXPECTED BY MIDWEEK
FOLLOWED BY ANOTHER SURGE OF BITTER COLD.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
625 PM UPDATE...
DECENT AREA OF MODERATE TO HEAVY SNOW MOVING NORTH ACROSS EASTERN
NEW ENG AND ESPECIALLY SOUTH COASTAL MA EARLY THIS EVENING. HI-RES
GUIDANCE AND RAP DOING A PRETTY GOOD JOB SIGNALING THIS HEAVIER
SNOW AND SHIFTS THE AREA TO NE MA DURING THE EVENING.
LOCALIZED SNOWFALL RATES OF 1 TO 2 INCHES PER HOUR ARE LIKELY IN
SOME OF THE HEAVIER BANDS. SNOWFALL ACCUM OF 3-6 INCHES WITH
LOCALLY HIGHER AMOUNTS POSSIBLE ACROSS PARTS OF E MA THROUGH THIS
EVENING. SOME OF THE GUIDANCE IS TARGETING ESSEX COUNTY FOR SOME
HEAVY SNOWFALL THROUGH ABOUT 06Z AS THIS AREA OF HEAVIER SNOW
SHIFTS TO THE NORTH.
THEN CONSENSUS OF THE GUIDANCE STRONGLY INDICATING A DRY SLOT AND
LULL IN THE SNOW FROM ABOUT 03-09Z AS ONE AREA OF ENHANCED
SNOWFALL DEVELOPS TO THE N WHILE A SECOND AREA ASSOCD WITH THE
MID LEVEL LOW TAKES SHAPE SOUTH OF THE COAST WITH SNE IN BETWEEN
THESE AREAS.
THEREAFTER...EXPECT SNOW TO FILL BACK IN ACROSS THE
REGION LATE TONIGHT...ESPECIALLY E NEW ENG AS MID LEVEL LOW
BEGINS TO DEEPEN AS IT TRACKS S OF NEW ENG. ONE WILDCARD LATE
TONIGHT AND SUN MORNING IS POTENTIAL FOR CONVECTIVE BANDS OF VERY
HEAVY SNOW TO DEVELOP IN THE COMMA HEAD AS MID LEVEL LAPSE RATES
DECREASE TO 8-9 C/KM. THIS IS REALLY IMPRESSIVE CONVECTIVE
INSTABILITY. THERE IS NO WAY OF KNOWING WHERE THESE BANDS MAY
DEVELOP SIMILAR TO FORECASTING LOCATION OF SUMMERTIME CONVECTION
BUT WOULD NOT BE SURPRISED TO SEE LOCALIZED 3-4"/HOUR SNOWFALL
RATES AND THUNDERSNOW UNDER ONE OF THESE BANDS.
PREVIOUS DISCUSSION...
LOW PRES WILL TAKE SHAPE TONIGHT E OF THE NJ COAST...THEN RAPIDLY
INTENSIFY OVERNIGHT SE OF NANTUCKET OVERNIGHT AS STRONG H5 SHORT
WAVE RIDES INTO BASE OF DIGGING TROUGH...TRYING TO CUT OFF
OVERNIGHT AS THE TROUGH BEGINS TO BECOME NEGATIVELY TILTED.
NOTING THAT MOST SHORT RANGE MODELS DEVELOP THE INTENSIFYING LOW A
BIT FURTHER E THAN PREVIOUS RUNS...BUT STILL DO EXPECT A PERIOD OF
VERY STRONG WINDS AS LOW LEVEL NE JET QUICKLY INCREASES TO 50-65 KT
FROM 1000 TO 900 HPA ACROSS THE GULF OF MAINE ALONG WITH LAPSE
RATES ON ORDER 8.5C-10C/KM. BIG QUESTION AT THIS POINT WILL BE HOW
CLOSE TO THE COAST THIS OCCURS...ALLOWING THESE STRONG WINDS TO
MIX DOWN. AS COMMA HEAD ROTATES AROUND THE DEEPENING LOW
OFFSHORE...WILL SEE N-NE WINDS ALSO QUICKLY INCREASE TOWARD
DAYBREAK.
NEXT QUESTION THAT CONTINUES IS WHETHER THERE WILL BE A BREAK IN
THE PRECIP SHIELD OVERNIGHT AS THE LOW TAKES SHAPE. MODELS HAVING
THEIR ISSUES WITH THE TIMING OF THIS FEATURE BUT ALL DO SHOW THIS
IN ONE FORM OR ANOTHER. EXPECT LIGHT SNOW TO CONTINUE EARLY
TONIGHT...WITH SOME POCKETS OF MODERATE SNOW. THEN...AS THE COMMA
HEAD DEVELOPS AROUND THE RAPIDLY INTENSIFYING LOW AFTER
MIDNIGHT...EXPECT WRAP AROUND PRECIP TO WORK INTO NE MA SOMETIME
AROUND 08Z...THEN WORK S-SW ACROSS CENTRAL AND EASTERN AREAS
TOWARD DAYBREAK.
USED A BLEND OF PREVIOUS FORECAST ALONG WITH GFS AND EC...PLUS
THEIR ENSEMBLES. LEANED AGAINST USING THE 12Z NAM AS THIS RUN
SEEMED TO HAVE PROBLEMS HANDLING THE DEEPENING OF THE LOW.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
EXPECT LOW TO ELONGATE W-E TO THE E OF CAPE COD...DEEPENING TO
AROUND 975-980 HPA DURING SUNDAY. SOME TIMING ISSUES BETWEEN THE
TWO OP MODELS USED...THE GFS AND ECMWF IN BRINGING THE WRAP AROUND
MOISTURE ACROSS CENTRAL AND EASTERN AREAS. LEANED TOWARD ENSEMBLES
WITH SOMEWHAT QUICKER TIMING THAN THE 12Z EC RUN...CLOSER TO THE
GFS. WILL ALSO SEE WINDS INCREASE QUICKLY SUNDAY MORNING.
AS THE WINDS PICK UP...WILL SEE AREAS OF BLOWING SNOW DEVELOP.
WILL LIKELY SEE GUSTS UP TO AT LEAST 50 MPH...POSSIBLY UP TO
HURRICANE FORCE ACROSS THE CAPE AND ISLANDS. WHAT WILL ALSO HELP
IN KEEPING WINDS BLOWING IS THE ARCTIC AIRMASS THAT WORKS IN AS
THE LOW DEPARTS SUNDAY AFTERNOON. SNOWFALL SHOULD DIMINISH FROM
W-E DURING THE AFTERNOON...BUT THE BLOWING SNOW COULD KEEP
LOWER VISIBILITIES.
WITH THE STRONG MAINLY ONSHORE WINDS /N-NE DIRECTION/...WILL SEE
PROBLEMS WITH THE SUNDAY MORNING HIGH TIDE ACROSS THE NORMAL
PROBLEMATIC AREAS OF CAPE ANN AND THE SOUTH SHORE TO THE CAPE COD
BAY SHORELINE. PLEASE SEE THE COASTAL FLOOD SECTION BELOW.
WITH THE LOW A BIT FURTHER OFFSHORE...DID LOWER THE SNOW AMOUNTS
JUST A TAD...WITH MAX OF 10-14 INCHES ACROSS NE MA...8-10 INCHES
OVER N CENTRAL AND REMAINDER OF E MA...THEN DOWN TO 4-6 INCHES
OVER THE CT VALLEY. WITH THE STRONG WINDS...THOUGH...WILL LIKELY
SEE BLIZZARD CONDITIONS AT TIMES MAINLY DURING SUNDAY MORNING.
BEST SHOT REMAINS ACROSS E MA.
FINALLY...AS THE ARCTIC AIR WORKS IN ON THE STRONG N-NW WINDS
LATER SUNDAY...WIND CHILL VALUES WILL DROP TO -10 TO -20 ACROSS
CENTRAL AND WESTERN AREAS WITH THE LOWEST VALUES ACROSS THE HIGHER
TERRAIN BY AROUND SUNSET. WIND CHILL WARNINGS REMAIN IN EFFECT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
* COLDEST AIR OF THE SEASON EARLY NEXT WEEK
* DANGEROUSLY COLD WIND CHILLS SUNDAY NIGHT AND MONDAY MORNING
* ANOTHER STORM POSSIBLE BY MIDWEEK BUT CONFIDENCE IS LOW
* ANOTHER SURGE OF BITTER COLD FOLLOWS FOR THE END OF NEXT WEEK
SUNDAY NIGHT INTO MONDAY NIGHT...
WIND CHILL WARNINGS CONTINUE INTO MONDAY MORNING.
INTENSE LOW PRES WILL BE MOVING INTO NOVA SCOTIA SUN NIGHT WITH
STRONG NW WINDS DRAGGING DOWN THE COLDEST AIR OF THE SEASON INTO
SNE. MAINLY DRY CONDITIONS AND MOSTLY CLEAR SKIES...BUT OCEAN
EFFECT CLOUDS WILL LINGER OVER THE CAPE/ISLANDS AND IT APPEARS
SOME SNOW SHOWERS WILL AFFECT THE OUTER CAPE GIVEN HOW EXTREME THE
INSTABILITY WILL BE OVER THE OCEAN AS ARCTIC AIR MOVES IN. ANY
ACCUM SUN NIGHT SHOULD BE LESS THAN AN INCH AS MIXING DEPTH IS
RATHER SHALLOW...MOSTLY BELOW 900 MB AND TRAJECTORY WILL BE NW
WHICH WILL KEEP BULK OF ACTIVITY OFFSHORE.
BLOWING SNOW WILL BE AN ISSUE FOR MOST OF SUNDAY NIGHT. STILL
EXPECTING WIND GUSTS UP TO 50 MPH IN THE EARLY EVENING IN THE
COASTAL PLAIN BEFORE WINDS GRADUALLY DIMINISH THROUGH THE NIGHT
BUT STILL GUSTING TO 25-35 MPH OVERNIGHT...AND UP TO 45 MPH OUTER
CAPE/ISLANDS. CONSIDERABLE BLOWING SNOW AND REDUCED VSBYS.
THE MAIN STORY FOR SUN NIGHT INTO MON MORNING WILL BE THE BITTER
COLD AND DANGEROUSLY COLD WIND CHILLS. TEMPS WILL LIKELY BE 25-30
DEGREES BELOW NORMAL. USED A BLEND OF MOS AND 2M TEMPS WHICH
SHOW MINS DROPPING TO ZERO TO 10 BELOW ACROSS MOST OF SNE AND 10
TO 15 BELOW OVER THE HIGHER ELEVATIONS. EXPECT WIND CHILLS 20 TO
30 BELOW ZERO IN THE COASTAL PLAIN AND 30 TO 40 BELOW OVER THE
HIGHER ELEVATIONS IN CENTRAL AND W MA. THIS IS DANGEROUS COLD AND
FROSTBITE ON EXPOSED FLESH CAN OCCUR QUICKLY.
GUSTY NW WINDS WILL CONTINUE MONDAY AND DESPITE SUNSHINE MAXES
WILL ONLY REACH THE SINGLE NUMBERS TO LOWER TEENS. WIND CHILLS
DURING THE AFTERNOON WILL ONLY RECOVER INTO THE SINGLE NUMBERS
BELOW ZERO...BUT COLDER OVER THE HIGHER ELEVATIONS.
FOR MON NIGHT WINDS WILL FINALLY DIMINISH AS SFC RIDGE BUILDS IN
FROM THE WEST...BUT ANOTHER BITTER COLD NIGHT WITH MINS ZERO TO 10
BELOW ACROSS MUCH OF SNE...EXCEPT SINGLE NUMBERS NEAR THE COAST.
WIND CHILLS WILL BE 5 TO 20 BELOW AND ADVISORIES WILL LIKELY BE
NEEDED.
TUE...HIGH CLOUDS WILL BE MOVING INTO THE REGION. LIGHT WINDS
EXPECTED WITH SFC RIDGING OVER THE REGION AND TEMPS MODERATE INTO
THE TEENS AND POSSIBLY LOWER 20S IN THE COASTAL PLAIN.
TUESDAY NIGHT INTO WEDNESDAY NIGHT...
CONFIDENCE REMAINS SOMEWHAT LOW FOR THE SOUTHERN STREAM SYSTEM
EMERGING OFF THE MID ATLC COAST AND TRACKING SOUTH OF NEW
ENGLAND. MODELS HAVE STRUGGLED WITH THE TRACK WITH POOR RUN TO
RUN CONSISTENCY. LATEST DETERMINISTIC GUIDANCE KEEPS TRACK WELL
SOUTH OF THE BENCHMARK WITH GFS ON THE NW PERIPHERY OF THE
GUIDANCE ENVELOPE. THE GEFS MEMBERS ARE MOSTLY CLUSTERED CLOSE TO
THE BENCHMARK WITH NORMAL TIMING DIFFERENCES...WHILE THERE IS
CONSIDERABLE SPREAD AMONG THE ECENS MEMBERS. THE SHORTWAVE ENERGY
RESPONSIBLE FOR THE STORM IS NOT REACHING THE WEST COAST UNTIL
SUNDAY SO CONFIDENCE IN A GIVEN SOLUTION REMAINS LOW.
WE ARE LEANING TOWARD A BLEND OF ENSEMBLE MEAN SOLUTIONS WHICH
HAVE SHOWN LESS VARIABILITY BUT STILL HAVE TO LEAVE ALL MODEL
SOLUTIONS ON THE TABLE UNTIL SOME CLUSTERING IN THE GUIDANCE
EMERGES.
A TRACK CLOSE TO THE BENCHMARK WOULD BRING A MODERATE SNOW EVENT
TO E NEW ENG...ALTHOUGH PROGRESSIVE NATURE OF THIS SYSTEM WOULD
LIKELY PRECLUDE A BIG HIT. A FURTHER OFFSHORE TRACK WOULD HAVE A
MINIMAL IMPACT.
THURSDAY INTO FRIDAY...
ANOTHER SURGE OF BITTER COLD AND DANGEROUSLY COLD WIND CHILLS
FOLLOW FOR THU INTO FRI WITH 850 MB TEMPS DROPPING TO -20 TO
-30C...WHICH IS 2-3 SD BELOW NORMAL. MORE SUBZERO MINS THU NIGHT
AND FRI NIGHT WITH MAXES IN THE TEENS.
SATURDAY...
LOTS OF UNCERTAINTY AT THIS TIME RANGE. MODERATING TEMPS
EXPECTED...BUT ECMWF BRINGS SOME OVERRUNNING SNOW INTO SNE WHILE
GFS IS DRY.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SUNDAY/...
TONIGHT...MODERATE CONFIDENCE.
EXPECT -SN/SN TO CONTINUE. MAY SEE BRIEF IMPROVEMENT TO VFR
ACROSS CENTRAL AND WESTERN AREAS BETWEEN 03Z AND 06Z...OTHERWISE
MAINLY MVFR-IFR CIGS/VSBYS THROUGH MIDNIGHT. AFTER MIDNIGHT...
WINDS BECOME N-NE AND BEGIN TO INCREASE MAINLY ALONG THE E
COAST...SUSTAINED AT 20-30 KT WITH GUSTS UP TO 35-45 KT. EXPECT
LIFR-VLIFR CIGS/VSBYS IN SN/+SN. BLSN DEVELOPS AROUND OR AFTER
10Z.
SUNDAY...MODERATE CONFIDENCE.
STORM INTENSIFYING RAPIDLY OFFSHORE. N WINDS GUSTING AROUND 40-50
KTS ACROSS MUCH OF INTERIOR S NEW ENGLAND WITH GUSTS AROUND 50-65
KTS ACROSS E AND SE COASTAL TERMINALS WHERE +SN/BLSN EXPECTED.
STRONGEST WINDS AROUND MIDDAY. CIGS WILL IMPROVE ACROSS CENTRAL
AND WESTERN AREAS TO VFR...BUT LOW LEVEL VSBYS REDUCED WITH BLSN.
KBOS TAF...MODERATE CONFIDENCE IN TAF.
KBDL TAF...MODERATE CONFIDENCE IN TAF.
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
SUNDAY NIGHT INTO MONDAY...HIGH CONFIDENCE. CONDITIONS IMPROVE
TO VFR...EXCEPT LINGERING MVFR OVER THE OUTER CAPE IN OCEAN EFFECT
CLOUDS AND SCT SNOW SHOWERS SUN NIGHT. NW WIND GUSTS TO 40-45 KT
IN THE EVENING...THEN GRADUALLY DIMINISHING DURING THE NIGHT. NW
GUSTS 25-35 KT MON...STRONGEST OUTER CAPE/ISLANDS.
TUESDAY...HIGH CONFIDENCE. VFR WITH LIGHT WINDS.
TUESDAY NIGHT INTO WEDNESDAY...LOW CONFIDENCE. CONDITIONS WILL
DEPEND ON HOW CLOSE A COASTAL STORM TRACKS TO SNE. POTENTIAL FOR
IFR SNOW AND STRONG WINDS LATE TUE NIGHT INTO WED...BUT LESS
IMPACT IF STORM TRACKS WELL OFFSHORE.
THURSDAY...MODERATE CONFIDENCE. VFR. GUSTY NW WINDS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SUNDAY/...
TONIGHT AND SUNDAY...MODERATE CONFIDENCE.
EXPECT WINDS TO EVENTUALLY BACK N-NE OVERNIGHT AND RAPIDLY
INCREASE. EXPECT SUSTAINED WINDS UP TO 50-60 KT AND GUSTS UP TO
60-70 KT LATE TONIGHT THROUGH SUNDAY...HIGHEST ACROSS THE EASTERN
WATERS. SEAS WILL BUILD UP TO AROUND 15 FT TONIGHT WILL BUILD UP
TO AROUND 25 FT ACROSS THE EASTERN WATERS ON SUNDAY.
HEADLINES ON THE WATERS CONTINUED...EXCEPT TOOK DOWN THE HEAVY
FREEZING SPRAY WARNING FOR BOSTON HARBOR AND NARRAGANSETT BAY WITH
MUCH LOWER SEAS THERE. TOUGH TO GENERATE FREEZING SPRAY WITH LOW
SEAS AND MUCH LOWER FETCH. EXPECT REDUCED VSBYS IN MODERATE TO
HEAVY SNOW.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
SUNDAY NIGHT INTO MONDAY...MODERATE CONFIDENCE. MOSTLY GALE
FORCE NW WINDS...EXCEPT LINGERING STORM FORCE GUSTS OVER EASTERN
WATERS SUN EVENING. WINDS GRADUALLY DIMINISH THROUGH
MONDAY...POSSIBLY SUB GALE OVER NEARSHORE IN THE AFTERNOON AND
DROPPING BELOW SCA ALL WATERS BY LATE MON NIGHT. HEAVY FREEZING
SPRAY LIKELY SUN NIGHT INTO MON.
TUESDAY...HIGH CONFIDENCE. WINDS AND SEAS BELOW SCA AS HIGH PRES
BUILDS OVER THE WATERS.
WEDNESDAY...LOW CONFIDENCE. DEPENDING ON HOW CLOSE YET ANOTHER
STORM SYSTEM GETS TO THE SOUTHEASTERN WATERS...GALES OR SMALL
CRAFT ADVISORIES ARE LIKELY. A CLOSER TRACK WOULD SUGGEST GALES
WHILE A FURTHER SE TRACK WOULD SUGGEST SMALL CRAFT ADVISORIES.
WEDNESDAY NIGHT INTO THURSDAY...MODERATE CONFIDENCE. NW WIND
GUSTS APPROACHING GALE ARE LIKELY. MORE FREEZING SPRAY.
&&
.TIDES/COASTAL FLOODING...
MINOR TO MODERATE COASTAL FLOODING AND AREAS OF SIGNIFICANT BEACH
EROSION ARE EXPECTED FOR THE SALISBURY TO CAPE ANN AND HULL TO
DENNIS REACHES OF COASTLINE. THE COASTAL FLOOD WARNING REMAINS IN
EFFECT FOR THOSE AREAS. MINOR COASTAL FLOODING IS STILL EXPECTED
ALONG A FEW PORTIONS OF SHORE BORDERING BOSTON HARBOR AND NANTUCKET
HARBOR...AND A COASTAL FLOOD ADVISORY REMAINS IN EFFECT THERE. THE
NORTH SHORE FROM GLOUCESTER TO LYNN TECHNICALLY FALLS UNDER THE
COASTAL FLOOD WARNING BUT THAT IS ONLY BECAUSE THE ZONE INCORPORATES
ALL OF THE ESSEX COUNTY COAST. WE ANTICIPATE NO WORSE THAN MINOR
COASTAL FLOODING FROM GLOUCESTER TO LYNN WITH THIS STORM.
WE HAVE ONLY MADE FAIRLY MINOR TWEAKS TO THE FORECAST STORM SURGE
AND WAVE HEIGHT FOR THE TIME OF THE HIGH TIDE SUNDAY MORNING...730
AM TO 830 AM MOST LOCATIONS. BOTH THE ETSS AND ESTOFS STORM SURGE
GUIDANCE INCREASED SOME ON THE 1200 UTC RUN. THAT GUIDANCE AND THE
LATEST POSITIONING/CONFIGURATION OF THE LOW LEVEL JET WAS IMPETUS
TO INCREASE THE STORM SURGE BY A FEW TENTHS ALONG THE SCITUATE TO
DENNIS REACH OF COASTLINE. THE OVERALL PICTURE OF EXPECTED IMPACTS
AND WARNINGS/ADVISORIES HAS NOT CHANGED APPRECIABLY. AT THE TIME
OF THE SUNDAY MORNING HIGH TIDE...WE ANTICIPATE A STORM SURGE OF 2
TO 2.5 FEET ALONG THE MA EAST COAST AND WAVES 15 TO 20 FEET
SEVERAL MILES OFF THE COAST.
THE SURGE AND SEAS WILL CONTINUE TO BUILD DURING THE OUTGOING TIDE
AND WILL PROBABLY CAUSE THE TIDE TO RECEDE MUCH SLOWER THAN NORMAL
AND MAY EVEN CREST AS MUCH AS A HALF HOUR AFTER THE TIME OF THE
SCHEDULED ASTRONOMICAL HIGH TIDE IN SOME LOCATIONS. ALONG THE CAPE
COD BAY SHORE FROM SANDWICH TO DENNIS...THE STORM SURGE MAY CREST
NEAR OR EVEN A LITTLER HIGHER THAN 3.5 FEET BUT SEVERAL HOURS AFTER
THE TIME OF THE ASTRONOMICAL HIGH TIDE.
THE SUNDAY EVENING HIGH TIDE IS LOWER ASTRONOMICALLY...AND THE WIND
SHOULD HAVE BECOME OFFSHORE FOR MOST SHORELINES BY THAT TIME. THUS
WE ANTICIPATE AT THIS TIME LITTLE OR NO IMPACT FOR THE SUNDAY
EVENING HIGH TIDE.
&&
.CLIMATE...
PRESIDENTS DAY MONDAY WILL BE VERY COLD ALTHOUGH SOME OF THAT WILL
BE DUE TO THE WIND. SOME OF THE LOW MAXIMUM RECORDS MAY BE AT
RISK. HERE ARE THE COLD TEMPERATURE RECORDS FOR THAT DATE.
FEBRUARY 16 RECORD LOW
BOSTON ...... -9 IN 1943
PROVIDENCE... -10 IN 1943
WORCESTER.... -24 IN 1943
HARTFORD .... -24 IN 1943
FEBRUARY 16 RECORD LOW MAXIMUM
BOSTON ...... 14 IN 1943
PROVIDENCE... 16 LATEST IN 1943
WORCESTER.... 12 LATEST IN 1963
HARTFORD..... 12 IN 2003
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WIND CHILL WARNING FROM 4 PM SUNDAY TO 8 AM EST MONDAY FOR
CTZ002>004.
WINTER STORM WARNING UNTIL 4 PM EST SUNDAY FOR CTZ002-003.
WINTER STORM WARNING UNTIL 7 PM EST SUNDAY FOR CTZ004.
MA...BLIZZARD WARNING UNTIL 4 AM EST MONDAY FOR MAZ005-013-017-018-
020-021-023.
COASTAL FLOOD WARNING FROM 6 AM TO 11 AM EST SUNDAY FOR MAZ007-
019-022.
WIND CHILL WARNING FROM 4 PM SUNDAY TO 8 AM EST MONDAY FOR
MAZ005>007-010>019-026.
BLIZZARD WARNING UNTIL 7 AM EST MONDAY FOR MAZ006-007-014>016-
019-022-024.
COASTAL FLOOD ADVISORY FROM 6 AM TO 11 AM EST SUNDAY FOR
MAZ015-016-024.
WINTER STORM WARNING UNTIL 4 PM EST SUNDAY FOR MAZ002-003-
008>011.
WINTER STORM WARNING UNTIL 7 PM EST SUNDAY FOR MAZ004-012-026.
WIND CHILL WARNING FROM 4 PM SUNDAY TO 11 AM EST MONDAY FOR
MAZ002>004-008-009.
RI...BLIZZARD WARNING UNTIL 4 AM EST MONDAY FOR RIZ006>008.
WIND CHILL WARNING FROM 4 PM SUNDAY TO 8 AM EST MONDAY FOR
RIZ001>004.
WINTER STORM WARNING UNTIL 7 PM EST SUNDAY FOR RIZ001>005.
MARINE...HEAVY FREEZING SPRAY WARNING FROM 10 AM SUNDAY TO 7 AM EST
MONDAY FOR ANZ231>235-237-250-251-254>256.
HURRICANE FORCE WIND WARNING FROM 7 AM TO 7 PM EST SUNDAY FOR
ANZ231-232-250-254-255.
STORM WARNING FROM 4 AM SUNDAY TO 5 AM EST MONDAY FOR ANZ230-
233>237-251-256.
&&
$$
SYNOPSIS...KJC/EVT
NEAR TERM...KJC/EVT
SHORT TERM...EVT
LONG TERM...KJC
AVIATION...KJC/EVT
MARINE...KJC/EVT
TIDES/COASTAL FLOODING...THOMPSON
CLIMATE...WTB
AREA FORECAST DISCUSSION
NWS TAUNTON MA
625 PM EST SAT FEB 14 2015
.SYNOPSIS...
A POWERFUL OFFSHORE STORM WILL RAPIDLY DEVELOP TONIGHT THROUGH
SUNDAY. THERE WILL BE A PERIOD OF BLIZZARD CONDITIONS ACROSS
COASTAL COMMUNITIES SUNDAY MORNING...ALONG WITH HURRICANE FORCE
WIND GUSTS ACROSS THE OUTER CAPE AND NANTUCKET. EXCEPTIONALLY
COLD AIR...THE COLDEST OF THE SEASON...FOLLOWS LATE SUNDAY INTO
TUESDAY MORNING. ANOTHER STORM SYSTEM IS EXPECTED BY MIDWEEK
FOLLOWED BY ANOTHER SURGE OF BITTER COLD.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
625 PM UPDATE...
DECENT AREA OF MODERATE TO HEAVY SNOW MOVING NORTH ACROSS EASTERN
NEW ENG AND ESPECIALLY SOUTH COASTAL MA EARLY THIS EVENING. HI-RES
GUIDANCE AND RAP DOING A PRETTY GOOD JOB SIGNALING THIS HEAVIER
SNOW AND SHIFTS THE AREA TO NE MA DURING THE EVENING.
LOCALIZED SNOWFALL RATES OF 1 TO 2 INCHES PER HOUR ARE LIKELY IN
SOME OF THE HEAVIER BANDS. SNOWFALL ACCUM OF 3-6 INCHES WITH
LOCALLY HIGHER AMOUNTS POSSIBLE ACROSS PARTS OF E MA THROUGH THIS
EVENING. SOME OF THE GUIDANCE IS TARGETING ESSEX COUNTY FOR SOME
HEAVY SNOWFALL THROUGH ABOUT 06Z AS THIS AREA OF HEAVIER SNOW
SHIFTS TO THE NORTH.
THEN CONSENSUS OF THE GUIDANCE STRONGLY INDICATING A DRY SLOT AND
LULL IN THE SNOW FROM ABOUT 03-09Z AS ONE AREA OF ENHANCED
SNOWFALL DEVELOPS TO THE N WHILE A SECOND AREA ASSOCD WITH THE
MID LEVEL LOW TAKES SHAPE SOUTH OF THE COAST WITH SNE IN BETWEEN
THESE AREAS.
THEREAFTER...EXPECT SNOW TO FILL BACK IN ACROSS THE
REGION LATE TONIGHT...ESPECIALLY E NEW ENG AS MID LEVEL LOW
BEGINS TO DEEPEN AS IT TRACKS S OF NEW ENG. ONE WILDCARD LATE
TONIGHT AND SUN MORNING IS POTENTIAL FOR CONVECTIVE BANDS OF VERY
HEAVY SNOW TO DEVELOP IN THE COMMA HEAD AS MID LEVEL LAPSE RATES
DECREASE TO 8-9 C/KM. THIS IS REALLY IMPRESSIVE CONVECTIVE
INSTABILITY. THERE IS NO WAY OF KNOWING WHERE THESE BANDS MAY
DEVELOP SIMILAR TO FORECASTING LOCATION OF SUMMERTIME CONVECTION
BUT WOULD NOT BE SURPRISED TO SEE LOCALIZED 3-4"/HOUR SNOWFALL
RATES AND THUNDERSNOW UNDER ONE OF THESE BANDS.
PREVIOUS DISCUSSION...
LOW PRES WILL TAKE SHAPE TONIGHT E OF THE NJ COAST...THEN RAPIDLY
INTENSIFY OVERNIGHT SE OF NANTUCKET OVERNIGHT AS STRONG H5 SHORT
WAVE RIDES INTO BASE OF DIGGING TROUGH...TRYING TO CUT OFF
OVERNIGHT AS THE TROUGH BEGINS TO BECOME NEGATIVELY TILTED.
NOTING THAT MOST SHORT RANGE MODELS DEVELOP THE INTENSIFYING LOW A
BIT FURTHER E THAN PREVIOUS RUNS...BUT STILL DO EXPECT A PERIOD OF
VERY STRONG WINDS AS LOW LEVEL NE JET QUICKLY INCREASES TO 50-65 KT
FROM 1000 TO 900 HPA ACROSS THE GULF OF MAINE ALONG WITH LAPSE
RATES ON ORDER 8.5C-10C/KM. BIG QUESTION AT THIS POINT WILL BE HOW
CLOSE TO THE COAST THIS OCCURS...ALLOWING THESE STRONG WINDS TO
MIX DOWN. AS COMMA HEAD ROTATES AROUND THE DEEPENING LOW
OFFSHORE...WILL SEE N-NE WINDS ALSO QUICKLY INCREASE TOWARD
DAYBREAK.
NEXT QUESTION THAT CONTINUES IS WHETHER THERE WILL BE A BREAK IN
THE PRECIP SHIELD OVERNIGHT AS THE LOW TAKES SHAPE. MODELS HAVING
THEIR ISSUES WITH THE TIMING OF THIS FEATURE BUT ALL DO SHOW THIS
IN ONE FORM OR ANOTHER. EXPECT LIGHT SNOW TO CONTINUE EARLY
TONIGHT...WITH SOME POCKETS OF MODERATE SNOW. THEN...AS THE COMMA
HEAD DEVELOPS AROUND THE RAPIDLY INTENSIFYING LOW AFTER
MIDNIGHT...EXPECT WRAP AROUND PRECIP TO WORK INTO NE MA SOMETIME
AROUND 08Z...THEN WORK S-SW ACROSS CENTRAL AND EASTERN AREAS
TOWARD DAYBREAK.
USED A BLEND OF PREVIOUS FORECAST ALONG WITH GFS AND EC...PLUS
THEIR ENSEMBLES. LEANED AGAINST USING THE 12Z NAM AS THIS RUN
SEEMED TO HAVE PROBLEMS HANDLING THE DEEPENING OF THE LOW.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
EXPECT LOW TO ELONGATE W-E TO THE E OF CAPE COD...DEEPENING TO
AROUND 975-980 HPA DURING SUNDAY. SOME TIMING ISSUES BETWEEN THE
TWO OP MODELS USED...THE GFS AND ECMWF IN BRINGING THE WRAP AROUND
MOISTURE ACROSS CENTRAL AND EASTERN AREAS. LEANED TOWARD ENSEMBLES
WITH SOMEWHAT QUICKER TIMING THAN THE 12Z EC RUN...CLOSER TO THE
GFS. WILL ALSO SEE WINDS INCREASE QUICKLY SUNDAY MORNING.
AS THE WINDS PICK UP...WILL SEE AREAS OF BLOWING SNOW DEVELOP.
WILL LIKELY SEE GUSTS UP TO AT LEAST 50 MPH...POSSIBLY UP TO
HURRICANE FORCE ACROSS THE CAPE AND ISLANDS. WHAT WILL ALSO HELP
IN KEEPING WINDS BLOWING IS THE ARCTIC AIRMASS THAT WORKS IN AS
THE LOW DEPARTS SUNDAY AFTERNOON. SNOWFALL SHOULD DIMINISH FROM
W-E DURING THE AFTERNOON...BUT THE BLOWING SNOW COULD KEEP
LOWER VISIBILITIES.
WITH THE STRONG MAINLY ONSHORE WINDS /N-NE DIRECTION/...WILL SEE
PROBLEMS WITH THE SUNDAY MORNING HIGH TIDE ACROSS THE NORMAL
PROBLEMATIC AREAS OF CAPE ANN AND THE SOUTH SHORE TO THE CAPE COD
BAY SHORELINE. PLEASE SEE THE COASTAL FLOOD SECTION BELOW.
WITH THE LOW A BIT FURTHER OFFSHORE...DID LOWER THE SNOW AMOUNTS
JUST A TAD...WITH MAX OF 10-14 INCHES ACROSS NE MA...8-10 INCHES
OVER N CENTRAL AND REMAINDER OF E MA...THEN DOWN TO 4-6 INCHES
OVER THE CT VALLEY. WITH THE STRONG WINDS...THOUGH...WILL LIKELY
SEE BLIZZARD CONDITIONS AT TIMES MAINLY DURING SUNDAY MORNING.
BEST SHOT REMAINS ACROSS E MA.
FINALLY...AS THE ARCTIC AIR WORKS IN ON THE STRONG N-NW WINDS
LATER SUNDAY...WIND CHILL VALUES WILL DROP TO -10 TO -20 ACROSS
CENTRAL AND WESTERN AREAS WITH THE LOWEST VALUES ACROSS THE HIGHER
TERRAIN BY AROUND SUNSET. WIND CHILL WARNINGS REMAIN IN EFFECT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
* COLDEST AIR OF THE SEASON EARLY NEXT WEEK
* DANGEROUSLY COLD WIND CHILLS SUNDAY NIGHT AND MONDAY MORNING
* ANOTHER STORM POSSIBLE BY MIDWEEK BUT CONFIDENCE IS LOW
* ANOTHER SURGE OF BITTER COLD FOLLOWS FOR THE END OF NEXT WEEK
SUNDAY NIGHT INTO MONDAY NIGHT...
WIND CHILL WARNINGS CONTINUE INTO MONDAY MORNING.
INTENSE LOW PRES WILL BE MOVING INTO NOVA SCOTIA SUN NIGHT WITH
STRONG NW WINDS DRAGGING DOWN THE COLDEST AIR OF THE SEASON INTO
SNE. MAINLY DRY CONDITIONS AND MOSTLY CLEAR SKIES...BUT OCEAN
EFFECT CLOUDS WILL LINGER OVER THE CAPE/ISLANDS AND IT APPEARS
SOME SNOW SHOWERS WILL AFFECT THE OUTER CAPE GIVEN HOW EXTREME THE
INSTABILITY WILL BE OVER THE OCEAN AS ARCTIC AIR MOVES IN. ANY
ACCUM SUN NIGHT SHOULD BE LESS THAN AN INCH AS MIXING DEPTH IS
RATHER SHALLOW...MOSTLY BELOW 900 MB AND TRAJECTORY WILL BE NW
WHICH WILL KEEP BULK OF ACTIVITY OFFSHORE.
BLOWING SNOW WILL BE AN ISSUE FOR MOST OF SUNDAY NIGHT. STILL
EXPECTING WIND GUSTS UP TO 50 MPH IN THE EARLY EVENING IN THE
COASTAL PLAIN BEFORE WINDS GRADUALLY DIMINISH THROUGH THE NIGHT
BUT STILL GUSTING TO 25-35 MPH OVERNIGHT...AND UP TO 45 MPH OUTER
CAPE/ISLANDS. CONSIDERABLE BLOWING SNOW AND REDUCED VSBYS.
THE MAIN STORY FOR SUN NIGHT INTO MON MORNING WILL BE THE BITTER
COLD AND DANGEROUSLY COLD WIND CHILLS. TEMPS WILL LIKELY BE 25-30
DEGREES BELOW NORMAL. USED A BLEND OF MOS AND 2M TEMPS WHICH
SHOW MINS DROPPING TO ZERO TO 10 BELOW ACROSS MOST OF SNE AND 10
TO 15 BELOW OVER THE HIGHER ELEVATIONS. EXPECT WIND CHILLS 20 TO
30 BELOW ZERO IN THE COASTAL PLAIN AND 30 TO 40 BELOW OVER THE
HIGHER ELEVATIONS IN CENTRAL AND W MA. THIS IS DANGEROUS COLD AND
FROSTBITE ON EXPOSED FLESH CAN OCCUR QUICKLY.
GUSTY NW WINDS WILL CONTINUE MONDAY AND DESPITE SUNSHINE MAXES
WILL ONLY REACH THE SINGLE NUMBERS TO LOWER TEENS. WIND CHILLS
DURING THE AFTERNOON WILL ONLY RECOVER INTO THE SINGLE NUMBERS
BELOW ZERO...BUT COLDER OVER THE HIGHER ELEVATIONS.
FOR MON NIGHT WINDS WILL FINALLY DIMINISH AS SFC RIDGE BUILDS IN
FROM THE WEST...BUT ANOTHER BITTER COLD NIGHT WITH MINS ZERO TO 10
BELOW ACROSS MUCH OF SNE...EXCEPT SINGLE NUMBERS NEAR THE COAST.
WIND CHILLS WILL BE 5 TO 20 BELOW AND ADVISORIES WILL LIKELY BE
NEEDED.
TUE...HIGH CLOUDS WILL BE MOVING INTO THE REGION. LIGHT WINDS
EXPECTED WITH SFC RIDGING OVER THE REGION AND TEMPS MODERATE INTO
THE TEENS AND POSSIBLY LOWER 20S IN THE COASTAL PLAIN.
TUESDAY NIGHT INTO WEDNESDAY NIGHT...
CONFIDENCE REMAINS SOMEWHAT LOW FOR THE SOUTHERN STREAM SYSTEM
EMERGING OFF THE MID ATLC COAST AND TRACKING SOUTH OF NEW
ENGLAND. MODELS HAVE STRUGGLED WITH THE TRACK WITH POOR RUN TO
RUN CONSISTENCY. LATEST DETERMINISTIC GUIDANCE KEEPS TRACK WELL
SOUTH OF THE BENCHMARK WITH GFS ON THE NW PERIPHERY OF THE
GUIDANCE ENVELOPE. THE GEFS MEMBERS ARE MOSTLY CLUSTERED CLOSE TO
THE BENCHMARK WITH NORMAL TIMING DIFFERENCES...WHILE THERE IS
CONSIDERABLE SPREAD AMONG THE ECENS MEMBERS. THE SHORTWAVE ENERGY
RESPONSIBLE FOR THE STORM IS NOT REACHING THE WEST COAST UNTIL
SUNDAY SO CONFIDENCE IN A GIVEN SOLUTION REMAINS LOW.
WE ARE LEANING TOWARD A BLEND OF ENSEMBLE MEAN SOLUTIONS WHICH
HAVE SHOWN LESS VARIABILITY BUT STILL HAVE TO LEAVE ALL MODEL
SOLUTIONS ON THE TABLE UNTIL SOME CLUSTERING IN THE GUIDANCE
EMERGES.
A TRACK CLOSE TO THE BENCHMARK WOULD BRING A MODERATE SNOW EVENT
TO E NEW ENG...ALTHOUGH PROGRESSIVE NATURE OF THIS SYSTEM WOULD
LIKELY PRECLUDE A BIG HIT. A FURTHER OFFSHORE TRACK WOULD HAVE A
MINIMAL IMPACT.
THURSDAY INTO FRIDAY...
ANOTHER SURGE OF BITTER COLD AND DANGEROUSLY COLD WIND CHILLS
FOLLOW FOR THU INTO FRI WITH 850 MB TEMPS DROPPING TO -20 TO
-30C...WHICH IS 2-3 SD BELOW NORMAL. MORE SUBZERO MINS THU NIGHT
AND FRI NIGHT WITH MAXES IN THE TEENS.
SATURDAY...
LOTS OF UNCERTAINTY AT THIS TIME RANGE. MODERATING TEMPS
EXPECTED...BUT ECMWF BRINGS SOME OVERRUNNING SNOW INTO SNE WHILE
GFS IS DRY.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SUNDAY/...
THROUGH 00Z...MODERATE TO HIGH CONFIDENCE.
EXPECT -SN WITH PERIODS OF MODERATE SN INTO THIS EVENING. EXPECT
MVFR-IFR CIG/VSBYS WITH LOCAL LIFR. GENERAL E-NE WINDS AT 5-10 KT
EXCEPT SE WINDS AROUND 10 KT ACROSS SE MA...CAPE COD AND THE
ISLANDS...WHICH WILL BEGIN TO BACK TO E-NE BY 00Z.
TONIGHT...MODERATE CONFIDENCE.
EXPECT -SN/SN TO CONTINUE...BUT TAPER OFF A BIT ACROSS CENTRAL
AND WESTERN AREAS BY 02Z-03Z. EXPECT MVFR-IFR CIGS/MVFR VSBYS
THROUGH MIDNIGHT. AFTER MIDNIGHT...WINDS BECOME N-NE AND BEGIN TO
INCREASE MAINLY ALONG THE E COAST...SUSTAINED AT 20-30 KT WITH
GUSTS UP TO 35-45 KT. EXPECT LIFR-VLIFR CIGS...AND VSBYS TO LOWER
BELOW 1/2 MILE IN SN/+SN AND BLSN BY 10Z-12Z.
SUNDAY...MODERATE CONFIDENCE.
STORM INTENSIFYING RAPIDLY OFFSHORE. N WINDS GUSTING AROUND 40-50
KTS ACROSS MUCH OF INTERIOR S NEW ENGLAND WITH GUSTS AROUND 50-65
KTS ACROSS E AND SE COASTAL TERMINALS WHERE +SN/BLSN EXPECTED.
STRONGEST WINDS AROUND MIDDAY. IFR-VLIFR CIGS/VSBYS. 1/4SM VSBYS
AT TIMES. AIRPORT WEATHER WARNINGS LIKELY TO BE NEEDED FOR GUSTY
WINDS AND SNOWFALL RATES OF AN INCH PER HOUR.
KBOS TAF...MODERATE CONFIDENCE IN TAF.
KBDL TAF...MODERATE CONFIDENCE IN TAF.
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
SUNDAY NIGHT INTO MONDAY...HIGH CONFIDENCE. CONDITIONS IMPROVE
TO VFR...EXCEPT LINGERING MVFR OVER THE OUTER CAPE IN OCEAN EFFECT
CLOUDS AND SCT SNOW SHOWERS SUN NIGHT. NW WIND GUSTS TO 40-45 KT
IN THE EVENING...THEN GRADUALLY DIMINISHING DURING THE NIGHT. NW
GUSTS 25-35 KT MON...STRONGEST OUTER CAPE/ISLANDS.
TUESDAY...HIGH CONFIDENCE. VFR WITH LIGHT WINDS.
TUESDAY NIGHT INTO WEDNESDAY...LOW CONFIDENCE. CONDITIONS WILL
DEPEND ON HOW CLOSE A COASTAL STORM TRACKS TO SNE. POTENTIAL FOR
IFR SNOW AND STRONG WINDS LATE TUE NIGHT INTO WED...BUT LESS
IMPACT IF STORM TRACKS WELL OFFSHORE.
THURSDAY...MODERATE CONFIDENCE. VFR. GUSTY NW WINDS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SUNDAY/...
TONIGHT AND SUNDAY...MODERATE CONFIDENCE.
AS LOW PRES INTENSIFIES E-SE OF NANTUCKET...EXPECT N-NE WINDS TO
BECOME N OVERNIGHT AND RAPIDLY INCREASE. EXPECT SUSTAINED WINDS UP
TO 50-60 KT AND GUSTS UP TO 60-70 KT LATE TONIGHT THROUGH SUNDAY...
HIGHEST ACROSS THE EASTERN WATERS. SEAS WILL BUILD UP TO AROUND
15 FT TONIGHT WILL BUILD UP TO AROUND 25 FT ACROSS THE EASTERN
WATERS ON SUNDAY.
HEADLINES ON THE WATERS CONTINUED...EXCEPT TOOK DOWN THE HEAVY
FREEZING SPRAY WARNING FOR BOSTON HARBOR AND NARRAGANSETT BAY WITH
MUCH LOWER SEAS THERE. TOUGH TO GENERATE FREEZING SPRAY WITH LOW
SEAS AND MUCH LOWER FETCH. EXPECT REDUCED VSBYS IN MODERATE TO
HEAVY SNOW.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
SUNDAY NIGHT INTO MONDAY...MODERATE CONFIDENCE. MOSTLY GALE
FORCE NW WINDS...EXCEPT LINGERING STORM FORCE GUSTS OVER EASTERN
WATERS SUN EVENING. WINDS GRADUALLY DIMINISH THROUGH
MONDAY...POSSIBLY SUB GALE OVER NEARSHORE IN THE AFTERNOON AND
DROPPING BELOW SCA ALL WATERS BY LATE MON NIGHT. HEAVY FREEZING
SPRAY LIKELY SUN NIGHT INTO MON.
TUESDAY...HIGH CONFIDENCE. WINDS AND SEAS BELOW SCA AS HIGH PRES
BUILDS OVER THE WATERS.
WEDNESDAY...LOW CONFIDENCE. DEPENDING ON HOW CLOSE YET ANOTHER
STORM SYSTEM GETS TO THE SOUTHEASTERN WATERS...GALES OR SMALL
CRAFT ADVISORIES ARE LIKELY. A CLOSER TRACK WOULD SUGGEST GALES
WHILE A FURTHER SE TRACK WOULD SUGGEST SMALL CRAFT ADVISORIES.
WEDNESDAY NIGHT INTO THURSDAY...MODERATE CONFIDENCE. NW WIND
GUSTS APPROACHING GALE ARE LIKELY. MORE FREEZING SPRAY.
&&
.TIDES/COASTAL FLOODING...
MINOR TO MODERATE COASTAL FLOODING AND AREAS OF SIGNIFICANT BEACH
EROSION ARE EXPECTED FOR THE SALISBURY TO CAPE ANN AND HULL TO
DENNIS REACHES OF COASTLINE. THE COASTAL FLOOD WARNING REMAINS IN
EFFECT FOR THOSE AREAS. MINOR COASTAL FLOODING IS STILL EXPECTED
ALONG A FEW PORTIONS OF SHORE BORDERING BOSTON HARBOR AND NANTUCKET
HARBOR...AND A COASTAL FLOOD ADVISORY REMAINS IN EFFECT THERE. THE
NORTH SHORE FROM GLOUCESTER TO LYNN TECHNICALLY FALLS UNDER THE
COASTAL FLOOD WARNING BUT THAT IS ONLY BECAUSE THE ZONE INCORPORATES
ALL OF THE ESSEX COUNTY COAST. WE ANTICIPATE NO WORSE THAN MINOR
COASTAL FLOODING FROM GLOUCESTER TO LYNN WITH THIS STORM.
WE HAVE ONLY MADE FAIRLY MINOR TWEAKS TO THE FORECAST STORM SURGE
AND WAVE HEIGHT FOR THE TIME OF THE HIGH TIDE SUNDAY MORNING...730
AM TO 830 AM MOST LOCATIONS. BOTH THE ETSS AND ESTOFS STORM SURGE
GUIDANCE INCREASED SOME ON THE 1200 UTC RUN. THAT GUIDANCE AND THE
LATEST POSITIONING/CONFIGURATION OF THE LOW LEVEL JET WAS IMPETUS
TO INCREASE THE STORM SURGE BY A FEW TENTHS ALONG THE SCITUATE TO
DENNIS REACH OF COASTLINE. THE OVERALL PICTURE OF EXPECTED IMPACTS
AND WARNINGS/ADVISORIES HAS NOT CHANGED APPRECIABLY. AT THE TIME
OF THE SUNDAY MORNING HIGH TIDE...WE ANTICIPATE A STORM SURGE OF 2
TO 2.5 FEET ALONG THE MA EAST COAST AND WAVES 15 TO 20 FEET
SEVERAL MILES OFF THE COAST.
THE SURGE AND SEAS WILL CONTINUE TO BUILD DURING THE OUTGOING TIDE
AND WILL PROBABLY CAUSE THE TIDE TO RECEDE MUCH SLOWER THAN NORMAL
AND MAY EVEN CREST AS MUCH AS A HALF HOUR AFTER THE TIME OF THE
SCHEDULED ASTRONOMICAL HIGH TIDE IN SOME LOCATIONS. ALONG THE CAPE
COD BAY SHORE FROM SANDWICH TO DENNIS...THE STORM SURGE MAY CREST
NEAR OR EVEN A LITTLER HIGHER THAN 3.5 FEET BUT SEVERAL HOURS AFTER
THE TIME OF THE ASTRONOMICAL HIGH TIDE.
THE SUNDAY EVENING HIGH TIDE IS LOWER ASTRONOMICALLY...AND THE WIND
SHOULD HAVE BECOME OFFSHORE FOR MOST SHORELINES BY THAT TIME. THUS
WE ANTICIPATE AT THIS TIME LITTLE OR NO IMPACT FOR THE SUNDAY
EVENING HIGH TIDE.
&&
.CLIMATE...
PRESIDENTS DAY MONDAY WILL BE VERY COLD ALTHOUGH SOME OF THAT WILL
BE DUE TO THE WIND. SOME OF THE LOW MAXIMUM RECORDS MAY BE AT
RISK. HERE ARE THE COLD TEMPERATURE RECORDS FOR THAT DATE.
FEBRUARY 16 RECORD LOW
BOSTON ...... -9 IN 1943
PROVIDENCE... -10 IN 1943
WORCESTER.... -24 IN 1943
HARTFORD .... -24 IN 1943
FEBRUARY 16 RECORD LOW MAXIMUM
BOSTON ...... 14 IN 1943
PROVIDENCE... 16 LATEST IN 1943
WORCESTER.... 12 LATEST IN 1963
HARTFORD..... 12 IN 2003
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WIND CHILL WARNING FROM 4 PM SUNDAY TO 8 AM EST MONDAY FOR
CTZ002>004.
WINTER STORM WARNING UNTIL 4 PM EST SUNDAY FOR CTZ002-003.
WINTER STORM WARNING UNTIL 7 PM EST SUNDAY FOR CTZ004.
MA...BLIZZARD WARNING UNTIL 4 AM EST MONDAY FOR MAZ005-013-017-018-
020-021-023.
COASTAL FLOOD WARNING FROM 6 AM TO 11 AM EST SUNDAY FOR MAZ007-
019-022.
WIND CHILL WARNING FROM 4 PM SUNDAY TO 8 AM EST MONDAY FOR
MAZ005>007-010>019-026.
BLIZZARD WARNING UNTIL 7 AM EST MONDAY FOR MAZ006-007-014>016-
019-022-024.
COASTAL FLOOD ADVISORY FROM 6 AM TO 11 AM EST SUNDAY FOR
MAZ015-016-024.
WINTER STORM WARNING UNTIL 4 PM EST SUNDAY FOR MAZ002-003-
008>011.
WINTER STORM WARNING UNTIL 7 PM EST SUNDAY FOR MAZ004-012-026.
WIND CHILL WARNING FROM 4 PM SUNDAY TO 11 AM EST MONDAY FOR
MAZ002>004-008-009.
RI...BLIZZARD WARNING UNTIL 4 AM EST MONDAY FOR RIZ006>008.
WIND CHILL WARNING FROM 4 PM SUNDAY TO 8 AM EST MONDAY FOR
RIZ001>004.
WINTER STORM WARNING UNTIL 7 PM EST SUNDAY FOR RIZ001>005.
MARINE...HEAVY FREEZING SPRAY WARNING FROM 10 AM SUNDAY TO 7 AM EST
MONDAY FOR ANZ231>235-237-250-251-254>256.
HURRICANE FORCE WIND WARNING FROM 7 AM TO 7 PM EST SUNDAY FOR
ANZ231-232-250-254-255.
STORM WARNING FROM 4 AM SUNDAY TO 5 AM EST MONDAY FOR ANZ230-
233>237-251-256.
&&
$$
SYNOPSIS...KJC/EVT
NEAR TERM...KJC/EVT
SHORT TERM...EVT
LONG TERM...KJC
AVIATION...KJC/EVT
MARINE...KJC/EVT
TIDES/COASTAL FLOODING...
CLIMATE...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1024 PM EST SAT FEB 14 2015
.SYNOPSIS...
LOW PRESSURE WILL RAPIDLY INTENSIFY JUST TO OUR EAST AS IT THEN
TRACKS TO THE OFFSHORE WATERS OF NEW ENGLAND THROUGH SUNDAY. THE
STORM CENTER IS EXPECTED TO REACH NOVA SCOTIA ON SUNDAY. HIGH
PRESSURE IS ANTICIPATED TO BUILD FROM THE GREAT LAKES ON SUNDAY
NIGHT TO THE NORTHEASTERN STATES FOR MONDAY INTO TUESDAY. LOW
PRESSURE IS THEN FORECAST TO BE LOCATED OVER THE WATERS OFF THE
CAROLINAS ON TUESDAY, BEFORE PASSING WELL TO OUR SOUTHEAST AND EAST
AND STRENGTHENING TUESDAY NIGHT. ANOTHER ARCTIC FRONT IS EXPECTED
TO ARRIVE ON WEDNESDAY WITH HIGH PRESSURE FOLLOWING FOR THE END OF
THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
LOW PRESSURE CONTINUES TO ORGANIZE AND INTENSITY NOW JUST EAST OF
OUR ATLANTIC COAST. A RATHER DYNAMIC SITUATION UNFOLDED EARLIER
WHICH RESULTED IN BANDING FEATURES FROM NEAR THE PHILADELPHIA
METRO ON SOUTH AND EASTWARD. WE RECEIVED SOME REPORTS OF 2-4
INCHES OF SNOW WITHIN ABOUT AN HOUR FROM NORTHERN DELAWARE TO
SALEM, CUMBERLAND, GLOUCESTER AND CAMDEN COUNTIES. THIS FEATURE
SHIFTED EASTWARD AND IS NOW CLEARING THE COAST. FARTHER WEST AND
NORTH, A SNOW SQUALL MOVED THROUGH WITH EVEN SOME LIGHTNING
REPORTED. THE WATER VAPOR SHOWS PLENTY OF SHORT WAVE ENERGY AND
ALSO WIND ENERGY DIVING INTO THE MID ATLANTIC, WHICH WILL RAPIDLY
INTENSITY THE SURFACE LOW AS IT TRACKS OFFSHORE. THE RAP AND HRRR
GUIDANCE SUGGESTING SOME WRAPAROUND SNOWS LINGER FOR PORTIONS OF
THE REGION, AND WE ARE SEEING SOME REDEVELOPMENT TAKING PLACE WEST
OF PHILADELPHIA AS OF 03Z. THEREFORE, ADJUSTMENTS WERE MADE TO THE
FORECAST AND THE STORM TOTAL SNOW MAP WAS RE-POSTED TO GET THE
IDEA ON WHAT IS EXPECTED. THE AMOUNTS HAVE VARIED GIVEN THE
EARLIER BANDING THAT TOOK PLACE ACROSS THE SOUTHERN AREAS.
WE WILL MAINTAIN THE WINTER WEATHER ADVISORY FOR MUCH OF THE AREA
WITH SOME MAINLY LIGHT ADDITIONAL SNOWFALL EXPECTED, BUT MAINLY
BECAUSE OF STRONG WINDS RESULTING IN BLOWING SNOW WITH
SIGNIFICANTLY REDUCED VISIBILITIES. ALSO, TEMPERATURES WILL BE
PLUMMETING OVERNIGHT.
DUE TO THE RAPIDLY INTENSIFYING STORM AND LOTS OF WIND ENERGY
ALOFT, NORTHWEST WINDS WILL INCREASE WITH GUSTS IN THE 50 TO 60
MPH RANGE AFTER 3 AM OR SO. THIS WILL BE ABOUT THE TIME WHEN THE
AXIS OF THE MID-LEVEL TROUGH MOVES THROUGH, AND ONCE THAT
HAPPENS, COLD AIR ADVECTION WILL BEGIN IN EARNEST, AND THE
TEMPERATURE WILL START A FREE-FALL INTO THE SINGLE
DIGITS...ESPECIALLY UP NORTH. THE COMBINATION OF VERY STRONG WINDS
AND EXTREMELY COLD TEMPERATURES WILL PRODUCE WIND CHILL VALUES
LESS THAN (COLDER THAN) MINUS 20 DEGREE F IN OUR NORTHERN TIER
COUNTIES...SO A WIND CHILL WARNING IS IN EFFECT FOR THOSE AREAS
STARTING EARLY SUNDAY MORNING.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
WINDY CONDITIONS WILL CONTINUE THROUGH THE DAY...WITH EXTREMELY
WINDY CONDITIONS THROUGH THE MORNING HOURS. GUSTS IN THE 50 TO 60
MPH RANGE ARE EXPECTED...WITH A FEW ISOLATED HIGHER GUSTS
POSSIBLE. THE BIG CONCERN IS POWER OUTAGES DUE TO FALLING LIMBS ON
WIRES COMBINED WITH EXTREMELY COLD TEMPERATURES. THIS IS
POTENTIALLY A VERY DANGEROUS SITUATION. DAYTIME HEATING UNDER
CLEAR SKIES WON/T HELP TEMPERATURES RECOVER MUCH FROM THEIR
OVERNIGHT LOWS GIVEN THE STRENGTH OF THE COLD AIR ADVECTION. HIGHS
IN THE NORTH WON`T GET OUT OF THE SINGLE DIGITS...AND HIGHS IN THE
SOUTH WILL ONLY BE IN THE TEENS. WIND CHILL WARNINGS ARE POSTED
FOR THE FAR NORTH...WITH WIND CHILL ADVISORIES POSTED FOR MOST
OTHER AREAS TO THE SOUTH LATER IN THE DAY AS TEMPERATURES START TO
FALL ONCE THE SUN STARTS TO SET. HIGH WIND WARNINGS ARE IN EFFECT
THE ENTIRE CWA INTO SUNDAY AFTERNOON. WINDS ARE EXPECTED TO
SUBSIDE SOMEWHAT DURING THE AFTERNOON HOURS AND SHOULDN/T BE AS
SEVERE BY LATE IN THE DAY. WITH THE STRONG WINDS...BLOWING SNOW
WILL CONTINUE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
THE STORM SYSTEM IS EXPECTED TO BE LOCATED OVER NOVA SCOTIA ON
SUNDAY NIGHT AS HIGH PRESSURE SLOWLY BUILDS TOWARD OUR REGION FROM
THE GREAT LAKES. THE PRESSURE GRADIENT WILL CONTINUE TO LESSEN
SLOWLY ON SUNDAY NIGHT IN OUR REGION AND MORE MARKEDLY ON MONDAY.
AS A RESULT, IT SHOULD REMAIN BRISK ON SUNDAY NIGHT EVEN AS WIND
SPEEDS DIMINISH GRADUALLY. HOWEVER, THE DECREASE IN WIND SPEEDS
WILL LIKELY BE QUITE NOTICEABLE ON MONDAY.
THE WIND SHOULD REMAIN STRONG ENOUGH AND TEMPERATURES LOW ENOUGH
ON SUNDAY NIGHT INTO MONDAY MORNING TO WARRANT THE CONTINUATION OF
A WIND CHILL WARNING FOR THE POCONOS AND FOR SUSSEX COUNTY, NEW
JERSEY AND A WIND CHILL ADVISORY ELSEWHERE IN OUR FORECAST AREA.
BOTH THE WARNING AND THE ADVISORY WILL RUN UNTIL 1100 AM MONDAY.
MINIMUM TEMPERATURES ARE ANTICIPATED TO RANGE FROM AROUND -10 TO
-15 IN THE POCONOS TO AROUND +5 IN SOUTHERN DELAWARE EARLY ON
MONDAY MORNING. IT IS POSSIBLE THAT PHILADELPHIA WILL RECORD ITS
FIRST SUB ZERO TEMPERATURE SINCE JANUARY 19, 1994. IT WILL BE
CLOSE.
THE AREA OF HIGH PRESSURE IS FORECAST TO BUILD ACROSS OUR REGION
ON MONDAY AND TUESDAY AND IT SHOULD MODIFY GRADUALLY. HIGHS ARE
EXPECTED TO BE MAINLY IN THE TEENS AND LOWER 20S ON MONDAY WITH
LOWS MOSTLY IN THE SINGLE DIGITS ABOVE ZERO ON MONDAY NIGHT.
MAXIMUM TEMPERATURES ARE EXPECTED TO BE IN THE 20S AND LOWER 30S
ON TUESDAY.
CLOUDS SHOULD BE ON THE INCREASE ON TUESDAY AS THE HIGH LIFTS TO
OUR NORTHEAST. THERE REMAIN SOME DIFFERENCES IN THE MODEL
SOLUTIONS REGARDING THE LOW OR LOWS THAT ARE EXPECTED TO MOVE OFF
THE CAROLINA COAST AROUND TUESDAY BEFORE PASSING TO OUR SOUTHEAST
AND EAST. THE LATEST CONSENSUS SEEMS TO SUGGEST THAT THE BEST
CHANCE FOR ANY SNOW IS FROM LATE TUESDAY INTO TUESDAY NIGHT WITH
THE BETTER POTENTIAL FOR ACCUMULATING SNOW ON THE COASTAL PLAIN.
HOWEVER, IT REMAINS A LOW CONFIDENCE FORECAST AND IT WILL LIKELY
BE ADJUSTED AS WE GET CLOSER TO THE EVENT.
THERE REMAINS FAIRLY GOOD AGREEMENT ON THE ARRIVAL OF ANOTHER
ARCTIC FRONT ON WEDNESDAY. SNOW SHOWERS OR SNOW SQUALLS ARE
POSSIBLE WITH THE FRONT ALONG WITH A DEVELOPING BRISK NORTHWEST
WIND IN ITS WAKE FOR LATE WEDNESDAY AND WEDNESDAY NIGHT. THE
LATEST MODEL GUIDANCE IS NOT SUGGESTING WIND SPEEDS NEARLY AS
STRONG AS THOSE EXPECTED FOR TONIGHT INTO SUNDAY. NEVERTHELESS, WE
MAY HAVE ANOTHER ROUND OF HAZARDOUS WIND CHILL VALUES FROM
WEDNESDAY NIGHT INTO THURSDAY MORNING.
COLD HIGH PRESSURE IS FORECAST TO FOLLOW FOR THURSDAY INTO
SATURDAY. OUR NEXT AREA OF PRECIPITATION IS EXPECTED TO APPROACH
FROM THE SOUTHWEST AND WEST NEXT WEEKEND.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
PERIODS OF SNOW AT VARYING INTENSITY THROUGH THE OVERNIGHT,
RESULTING IN MVFR OR LOWER CONDITIONS. THE CEILINGS MAY GRADUALLY
IMPROVE THOUGH LATE, AND ESPECIALLY DURING SUNDAY. NORTHWEST WINDS
WILL GUST FROM 40 TO 50 KNOTS ACROSS THE REGION INTO SUNDAY THAT
WILL THEN TAPER OFF THROUGH THE AFTERNOON AND EVENING. SOME
UNCERTAINTY DOES EXIST INTO THE EXTEND OF CLOUD COVER ON SUNDAY
WITH A CLEARING TREND BY THE END OF THE DAY.
OUTLOOK...
SUNDAY NIGHT...VFR WITH A NORTHWEST WIND 15 TO 20 KNOTS GUSTING
NEAR 25 TO 30 KNOTS.
MONDAY AND MONDAY NIGHT...VFR.
TUESDAY...MAINLY VFR WITH A CHANCE OF SNOW DEVELOPING FROM SOUTH
TO NORTH IN THE REGION.
TUESDAY NIGHT...MVFR OR IFR CONDITIONS ARE POSSIBLE IN SNOW.
WEDNESDAY...MVFR OR IFR CONDITIONS ARE POSSIBLE IN SNOW OR SNOW
SHOWERS. A STRONG COLD FRONT IS FORECAST TO ARRIVE IN THE
AFTERNOON WITH A GUSTY NORTHWEST WIND DEVELOPING IN ITS WAKE.
WEDNESDAY NIGHT...VFR WITH A GUSTY NORTHWEST WIND.
THURSDAY...VFR.
&&
.MARINE...
STORM WARNINGS CONTINUE ON THE WATERS. ARCTIC FRONT TO CROSS THE
AREA THIS EVENING. A BURST OF GUSTY WINDS AND SNOW WILL ACCOMPANY
THE FRONT. WINDS STEADILY INCREASE THROUGH THE NIGHT UP TO GALE
FORCE TONIGHT AND CLOSE TO STORM FORCE BY DAWN SUN INTO SUN
AFTERNOON. GRADUAL IMPROVEMENT AFTER THAT. SNOW OVERNIGHT.
FREEZING SPRAY TONIGHT AND SUNDAY.
OUTLOOK...
SUNDAY NIGHT...A NORTHWESTERLY GALE ALONG WITH A HEAVY FREEZING
SPRAY WARNING. BLOW OUT TIDES ARE POSSIBLE, MAINLY ON THE TIDAL
DELAWARE RIVER.
MONDAY...SMALL CRAFT ADVISORY CONDITIONS ARE LIKELY DUE TO A
CONTINUED GUSTY NORTHWEST WIND. LIGHT TO MODERATE FREEZING SPRAY.
MONDAY NIGHT AND TUESDAY...NO MARINE HEADLINES ARE ANTICIPATED.
LIGHT FREEZING SPRAY IS POSSIBLE ON MONDAY EVENING.
TUESDAY NIGHT AND WEDNESDAY... A SMALL CRAFT ADVISORY IS
POSSIBLE.
WEDNESDAY NIGHT AND THURSDAY...NORTHWESTERLY GALE FORCE WIND
GUSTS MAY OCCUR. LIGHT TO MODERATE FREEZING SPRAY.
&&
.TIDES/COASTAL FLOODING...
THE VERY STRONG NORTHWESTERLY WIND THAT IS EXPECTED FOR TONIGHT
INTO SUNDAY WILL PUSH WATER AWAY FROM THE COASTS OF NEW JERSEY AND
DELAWARE. LOW WATER LEVELS ARE ANTICIPATED AND THEY HAVE THE
POTENTIAL TO AFFECT NAVIGATION. THE GREATEST IMPACT IS EXPECTED TO
BE ON THE TIDAL PORTION OF THE DELAWARE RIVER. WATERS LEVELS THERE
MAY FALL TO -2.5 TO -3.5 FEET MEAN LOWER LOW WATER ON SUNDAY
AFTERNOON BASED ON THE LATEST GUIDANCE. WHILE CONDITIONS MAY FALL
JUST SHORT OF THE CRITERION FOR A LOW WATER ADVISORY ALONG THE
COAST AND ON DELAWARE BAY, A SPECIAL STATEMENT MAY BE NEEDED FOR
THE TIDAL DELAWARE RIVER FOR THE LOW TIDE CYCLES ON SUNDAY
AFTERNOON AND AGAIN ON SUNDAY NIGHT. THE CRITERION FOR A LOW WATER
ADVISORY/SPECIAL STATEMENT IS AN EXPECTED WATER LEVEL OF -1.8 FEET
OR LESS MEAN LOWER LOW WATER.
&&
.CLIMATE...
AT THIS TIME WE ARE FORECASTING RECORD OR NEAR RECORD LOW
TEMPERATURES FOR MONDAY MORNING 2/16.
THOSE RECORD LOWS FOR THE 16TH FOLLOW
KACY 3 ABOVE 1888, 1875
KPHL 2 ABOVE 1888
KILG 2 ABOVE 1943
KTTN 1 ABOVE 1888
KGED 10 ABOVE 1987 (SHORTER PERIOD OF RECORD DATING BACK ONLY TO
1948)
KRDG 0 1904
KMPO -14 1943
KABE -7 1943
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...HIGH WIND WARNING UNTIL 2 PM EST SUNDAY FOR PAZ054-055-061-062.
WIND CHILL ADVISORY FROM 6 AM SUNDAY TO 11 AM EST MONDAY FOR
PAZ060>062-101-103-105.
HIGH WIND WARNING UNTIL 2 PM EST SUNDAY FOR PAZ060-070-071-
101>106.
WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR PAZ054-055-
060>062-070-071-101>106.
WIND CHILL ADVISORY FROM 4 PM SUNDAY TO 11 AM EST MONDAY FOR
PAZ070-071-102-104-106.
WIND CHILL WARNING FROM 6 AM SUNDAY TO 11 AM EST MONDAY FOR
PAZ054-055.
NJ...HIGH WIND WARNING UNTIL 2 PM EST SUNDAY FOR NJZ001-007-008.
WINTER WEATHER ADVISORY UNTIL 1 PM EST SUNDAY FOR NJZ001-008-
010-012>014.
WIND CHILL ADVISORY FROM 6 AM SUNDAY TO 11 AM EST MONDAY FOR
NJZ007>009.
HIGH WIND WARNING UNTIL 2 PM EST SUNDAY FOR NJZ009-010-012>027.
WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR NJZ007-009-
015>027.
WIND CHILL ADVISORY FROM 4 PM SUNDAY TO 11 AM EST MONDAY FOR
NJZ010-012>027.
WIND CHILL WARNING FROM 6 AM SUNDAY TO 11 AM EST MONDAY FOR
NJZ001.
DE...HIGH WIND WARNING UNTIL 2 PM EST SUNDAY FOR DEZ001>004.
WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR DEZ001.
WIND CHILL ADVISORY FROM 4 PM SUNDAY TO 11 AM EST MONDAY FOR
DEZ001>004.
MD...HIGH WIND WARNING UNTIL 2 PM EST SUNDAY FOR MDZ008-012-015-019-
020.
WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR MDZ008-012.
WIND CHILL ADVISORY FROM 4 PM SUNDAY TO 11 AM EST MONDAY FOR
MDZ008-012-015-019-020.
MARINE...HEAVY FREEZING SPRAY WARNING FROM 8 AM SUNDAY TO 6 AM EST
MONDAY FOR ANZ430-431-450>455.
STORM WARNING UNTIL 6 PM EST SUNDAY FOR ANZ430-431-450>455.
&&
$$
SYNOPSIS...GORSE/IOVINO
NEAR TERM...GAINES/GORSE
SHORT TERM...MIKETTA
LONG TERM...IOVINO
AVIATION...IOVINO/MIKETTA
MARINE...IOVINO/MIKETTA
TIDES/COASTAL FLOODING...
CLIMATE...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
658 PM EST SAT FEB 14 2015
.SYNOPSIS...
LOW PRESSURE WILL SLIDE EASTWARD ACROSS OUR REGION THIS EVENING.
THE SYSTEM IS FORECAST TO INTENSIFY RAPIDLY TONIGHT AS IT MOVES
OVER THE WATERS OFF NEW ENGLAND. THE STORM CENTER IS EXPECTED TO
REACH NOVA SCOTIA ON SUNDAY. HIGH PRESSURE IS ANTICIPATED TO BUILD
FROM THE GREAT LAKES ON SUNDAY NIGHT TO THE NORTHEASTERN STATES
FOR MONDAY INTO TUESDAY. LOW PRESSURE IS FORECAST TO BE LOCATED
OVER THE WATERS OFF THE CAROLINAS ON TUESDAY BEFORE PASSING WELL
TO OUR SOUTHEAST AND EAST AND STRENGTHENING ON TUESDAY NIGHT.
ANOTHER ARCTIC COLD FRONT FROM THE NORTHWEST IS EXPECTED TO ARRIVE
ON WEDNESDAY WITH HIGH PRESSURE FOLLOWING FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
WITH THE 6:30 PM UPDATE: DEWPOINTS WERE RAISED SEVERAL DEGREES
ACROSS THE REGION. EVENTHOUGH WINDS ARE LIGHTER CURRENTLY, THEY
SHOULD BE PICKING UP SHORTLY OUT OF THE SOUTH THEN THE NORTHWEST
AFTER THE FRONTAL PASSAGE. IN TERMS OF THE SNOWFALL, AN IMPRESSIVE
LINE OF SNOW SQUALLS WILL CONTINUE MOVING TOWARD THE REGION FROM
THE WEST. ANOTHER PERIOD OF SNOW IS DEVELOPING NEAR BALTIMORE.
CURRENT RAP AND HRRR RUNS SHOW THE SNOW SQUALL LINE WEAKENING SOME
AND THE PERIOD OF SNOW ACROSS MARYLAND MOVING NORTHEAST ALONG
INTERSTATE 95. THIS SHOULD TRACK UP INTERSTATE 295 AND POINTS JUST
TO THE EAST IN NJ THEN SLIDE OFFSHORE IN CENTRAL NJ. QPF AND
SNOWFALL HAVE BEEN RAISED SLIGHTLY IN THESE AREAS FOR THE EVENING.
THE RAP AND HRRR EARLIER HAD HEAVIER QPF THAN CURRENTLY
ADVERTISED. CHANGES IN SNOW TOTALS, WHILE SLIGHTLY HIGHER IN SPOTS
DO NOT REFLECT A MAJOR CHANGE FROM PREVIOUS FORECAST THINKING.
PREVIOUS UPDATE: A VERY STRONG COLD FRONT MOVING TOWARD CENTRAL PA
AT PRESS TIME WILL BARREL THROUGH OUR REGION EARLY THIS EVENING.
ONCE THE FRONT ARRIVES, SNOW COULD BECOME BRIEFLY HEAVY, WITH
VISIBILITIES DROPPING BECAUSE OF THE SNOW. WINDS WILL ALSO MAKE AN
ABRUPT CHANGE IN DIRECTION TO THE NORTHWEST, WITH GUSTS BETWEEN 20
AND 30 MPH TO START, BEFORE INCREASING EVEN MORE DURING THE
OVERNIGHT HOURS. MANY AREAS COULD SEE GUSTS IN THE 50 TO 60 MPH
RANGE AFTER 3 AM OR SO. THIS WILL BE ABOUT THE TIME WHEN THE AXIS
OF THE MID- LEVEL TROUGH MOVES THROUGH, AND ONCE THAT HAPPENS,
COLD AIR ADVECTION WILL BEGIN IN EARNEST, AND THE TEMPERATURE WILL
START A FREE-FALL INTO THE SINGLE DIGITS...ESPECIALLY UP NORTH.
THE COMBINATION OF VERY STRONG WINDS AND EXTREMELY COLD
TEMPERATURES WILL PRODUCE WIND CHILL VALUES LESS THAN (COLDER
THAN) MINUS 20 DEGREE F IN OUR NORTHERN TIER COUNTIES...SO A WIND
CHILL WARNING IS IN EFFECT FOR THOSE AREAS STARTING EARLY SUNDAY
MORNING. A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR OUR
ENTIRE CWA (EXCEPT THE DELMARVA SOUTH OF THE C&D CANAL) FOR
SNOW...4 TO 6 IN NORTH, 3 TO 4 IN THE LEHIGH VALLEY AND CENTRAL
NEW JERSEY...2 TO 3 IN THE PHILA EXURBS, 1 TO 2 IN THE IMMEDIATE
PHILA AREA...AND 1 INCH OR LESS FURTHER SOUTH. SNOW WILL BE FLUFFY
GIVEN THE LOW DEW POINT TEMPERATURES...SO IT WILL BLOW AROUND VERY
EASILY ONCE THE WIND PICKS UP. LOWS TONIGHT WILL DROP DOWN TO
ABOUT ZERO IN THE FAR NORTH...AND IN THE LOW TEENS FAR SOUTH.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
WINDY CONDITIONS WILL CONTINUE THROUGH THE DAY...WITH EXTREMELY
WINDY CONDITIONS THROUGH THE MORNING HOURS. GUSTS IN THE 50 TO 60
MPH RANGE ARE EXPECTED...WITH A FEW ISOLATED HIGHER GUSTS
POSSIBLE. THE BIG CONCERN IS POWER OUTAGES DUE TO FALLING LIMBS ON
WIRES COMBINED WITH EXTREMELY COLD TEMPERATURES. THIS IS
POTENTIALLY A VERY DANGEROUS SITUATION. DAYTIME HEATING UNDER
CLEAR SKIES WON/T HELP TEMPERATURES RECOVER MUCH FROM THEIR
OVERNIGHT LOWS GIVEN THE STRENGTH OF THE COLD AIR ADVECTION. HIGHS
IN THE NORTH WON`T GET OUT OF THE SINGLE DIGITS...AND HIGHS IN THE
SOUTH WILL ONLY BE IN THE TEENS. WIND CHILL WARNINGS ARE POSTED
FOR THE FAR NORTH...WITH WIND CHILL ADVISORIES POSTED FOR MOST
OTHER AREAS TO THE SOUTH LATER IN THE DAY AS TEMPERATURES START TO
FALL ONCE THE SUN STARTS TO SET. HIGH WIND WARNINGS ARE IN EFFECT
THE ENTIRE CWA INTO SUNDAY AFTERNOON. WINDS ARE EXPECTED TO
SUBSIDE SOMEWHAT DURING THE AFTERNOON HOURS AND SHOULDN/T BE AS
SEVERE BY LATE IN THE DAY. WITH THE STRONG WINDS...BLOWING SNOW
WILL CONTINUE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
THE STORM SYSTEM IS EXPECTED TO BE LOCATED OVER NOVA SCOTIA ON
SUNDAY NIGHT AS HIGH PRESSURE SLOWLY BUILDS TOWARD OUR REGION FROM
THE GREAT LAKES. THE PRESSURE GRADIENT WILL CONTINUE TO LESSEN
SLOWLY ON SUNDAY NIGHT IN OUR REGION AND MORE MARKEDLY ON MONDAY.
AS A RESULT, IT SHOULD REMAIN BRISK ON SUNDAY NIGHT EVEN AS WIND
SPEEDS DIMINISH GRADUALLY. HOWEVER, THE DECREASE IN WIND SPEEDS
WILL LIKELY BE QUITE NOTICEABLE ON MONDAY.
THE WIND SHOULD REMAIN STRONG ENOUGH AND TEMPERATURES LOW ENOUGH
ON SUNDAY NIGHT INTO MONDAY MORNING TO WARRANT THE CONTINUATION OF
A WIND CHILL WARNING FOR THE POCONOS AND FOR SUSSEX COUNTY, NEW
JERSEY AND A WIND CHILL ADVISORY ELSEWHERE IN OUR FORECAST AREA.
BOTH THE WARNING AND THE ADVISORY WILL RUN UNTIL 1100 AM MONDAY.
MINIMUM TEMPERATURES ARE ANTICIPATED TO RANGE FROM AROUND -10 TO
-15 IN THE POCONOS TO AROUND +5 IN SOUTHERN DELAWARE EARLY ON
MONDAY MORNING. IT IS POSSIBLE THAT PHILADELPHIA WILL RECORD ITS
FIRST SUB ZERO TEMPERATURE SINCE JANUARY 19, 1994. IT WILL BE
CLOSE.
THE AREA OF HIGH PRESSURE IS FORECAST TO BUILD ACROSS OUR REGION
ON MONDAY AND TUESDAY AND IT SHOULD MODIFY GRADUALLY. HIGHS ARE
EXPECTED TO BE MAINLY IN THE TEENS AND LOWER 20S ON MONDAY WITH
LOWS MOSTLY IN THE SINGLE DIGITS ABOVE ZERO ON MONDAY NIGHT.
MAXIMUM TEMPERATURES ARE EXPECTED TO BE IN THE 20S AND LOWER 30S
ON TUESDAY.
CLOUDS SHOULD BE ON THE INCREASE ON TUESDAY AS THE HIGH LIFTS TO
OUR NORTHEAST. THERE REMAIN SOME DIFFERENCES IN THE MODEL
SOLUTIONS REGARDING THE LOW OR LOWS THAT ARE EXPECTED TO MOVE OFF
THE CAROLINA COAST AROUND TUESDAY BEFORE PASSING TO OUR SOUTHEAST
AND EAST. THE LATEST CONSENSUS SEEMS TO SUGGEST THAT THE BEST
CHANCE FOR ANY SNOW IS FROM LATE TUESDAY INTO TUESDAY NIGHT WITH
THE BETTER POTENTIAL FOR ACCUMULATING SNOW ON THE COASTAL PLAIN.
HOWEVER, IT REMAINS A LOW CONFIDENCE FORECAST AND IT WILL LIKELY
BE ADJUSTED AS WE GET CLOSER TO THE EVENT.
THERE REMAINS FAIRLY GOOD AGREEMENT ON THE ARRIVAL OF ANOTHER
ARCTIC FRONT ON WEDNESDAY. SNOW SHOWERS OR SNOW SQUALLS ARE
POSSIBLE WITH THE FRONT ALONG WITH A DEVELOPING BRISK NORTHWEST
WIND IN ITS WAKE FOR LATE WEDNESDAY AND WEDNESDAY NIGHT. THE
LATEST MODEL GUIDANCE IS NOT SUGGESTING WIND SPEEDS NEARLY AS
STRONG AS THOSE EXPECTED FOR TONIGHT INTO SUNDAY. NEVERTHELESS, WE
MAY HAVE ANOTHER ROUND OF HAZARDOUS WIND CHILL VALUES FROM
WEDNESDAY NIGHT INTO THURSDAY MORNING.
COLD HIGH PRESSURE IS FORECAST TO FOLLOW FOR THURSDAY INTO
SATURDAY. OUR NEXT AREA OF PRECIPITATION IS EXPECTED TO APPROACH
FROM THE SOUTHWEST AND WEST NEXT WEEKEND.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TIMING OF THE HEAVY SNOW BURST LOOKS TO BE BETWEEN 00 (CLOSER TO RDG) AND
03Z (CLOSER TO ACY) ACROSS THE REGION, LASTING AN HOUR OR TWO IN
MOST PLACES. ACCUMULATIONS OF AN INCH OR TWO COULD OCCUR IN THIS
TIMEFRAME, ACCUMULATIONS ON RUNWAYS AS WELL. CEILINGS MAY DROP TO
IFR WITH THE HEAVIEST SNOW. CEILINGS SHOULD GRADUALLY REBOUND
OVERNIGHT. WINDS WILL SHIFT TO THE NORTHWEST AND INCREASE
THROUGHOUT THE NIGHT. GUSTS FROM 40 TO 50 KNOTS ARE LIKELY ACROSS
THE REGION INTO SUNDAY THAT WILL TAPE OFF THROUGH THE AFTERNOON
AND EVENING. SOME UNCERTAINTY DOES EXIST INTO THE EXTEND OF
CLOUDCOVER ON SUNDAY WITH A CLEARING TREND BY THE END OF THE DAY.
OUTLOOK...
SUNDAY NIGHT...VFR WITH A NORTHWEST WIND 15 TO 20 KNOTS GUSTING
NEAR 25 TO 30 KNOTS.
MONDAY AND MONDAY NIGHT...VFR.
TUESDAY...MAINLY VFR WITH A CHANCE OF SNOW DEVELOPING FROM SOUTH
TO NORTH IN THE REGION.
TUESDAY NIGHT...MVFR OR IFR CONDITIONS ARE POSSIBLE IN SNOW.
WEDNESDAY...MVFR OR IFR CONDITIONS ARE POSSIBLE IN SNOW OR SNOW
SHOWERS. A STRONG COLD FRONT IS FORECAST TO ARRIVE IN THE
AFTERNOON WITH A GUSTY NORTHWEST WIND DEVELOPING IN ITS WAKE.
WEDNESDAY NIGHT...VFR WITH A GUSTY NORTHWEST WIND.
THURSDAY...VFR.
&&
.MARINE...
STORM WARNINGS CONTINUE ON THE WATERS. ARCTIC FRONT TO CROSS THE
AREA THIS EVENING. A BURST OF GUSTY WINDS AND SNOW WILL ACCOMPANY
THE FRONT. WINDS STEADILY INCREASE THROUGH THE NIGHT UP TO GALE
FORCE TONIGHT AND CLOSE TO STORM FORCE BY DAWN SUN INTO SUN
AFTERNOON. GRADUAL IMPROVEMENT AFTER THAT. SNOW OVERNIGHT.
FREEZING SPRAY TONIGHT AND SUNDAY.
OUTLOOK...
SUNDAY NIGHT...A NORTHWESTERLY GALE ALONG WITH A HEAVY FREEZING
SPRAY WARNING. BLOW OUT TIDES ARE POSSIBLE, MAINLY ON THE TIDAL
DELAWARE RIVER.
MONDAY...SMALL CRAFT ADVISORY CONDITIONS ARE LIKELY DUE TO A
CONTINUED GUSTY NORTHWEST WIND. LIGHT TO MODERATE FREEZING SPRAY.
MONDAY NIGHT AND TUESDAY...NO MARINE HEADLINES ARE ANTICIPATED.
LIGHT FREEZING SPRAY IS POSSIBLE ON MONDAY EVENING.
TUESDAY NIGHT AND WEDNESDAY... A SMALL CRAFT ADVISORY IS
POSSIBLE.
WEDNESDAY NIGHT AND THURSDAY...NORTHWESTERLY GALE FORCE WIND
GUSTS MAY OCCUR. LIGHT TO MODERATE FREEZING SPRAY.
&&
.TIDES/COASTAL FLOODING...
THE VERY STRONG NORTHWESTERLY WIND THAT IS EXPECTED FOR TONIGHT
INTO SUNDAY WILL PUSH WATER AWAY FROM THE COASTS OF NEW JERSEY AND
DELAWARE. LOW WATER LEVELS ARE ANTICIPATED AND THEY HAVE THE
POTENTIAL TO AFFECT NAVIGATION. THE GREATEST IMPACT IS EXPECTED TO
BE ON THE TIDAL PORTION OF THE DELAWARE RIVER. WATERS LEVELS THERE
MAY FALL TO -2.5 TO -3.5 FEET MEAN LOWER LOW WATER ON SUNDAY
AFTERNOON BASED ON THE LATEST GUIDANCE. WHILE CONDITIONS MAY FALL
JUST SHORT OF THE CRITERION FOR A LOW WATER ADVISORY ALONG THE
COAST AND ON DELAWARE BAY, A SPECIAL STATEMENT MAY BE NEEDED FOR
THE TIDAL DELAWARE RIVER FOR THE LOW TIDE CYCLES ON SUNDAY
AFTERNOON AND AGAIN ON SUNDAY NIGHT. THE CRITERION FOR A LOW WATER
ADVISORY/SPECIAL STATEMENT IS AN EXPECTED WATER LEVEL OF -1.8 FEET
OR LESS MEAN LOWER LOW WATER.
&&
.CLIMATE...
AT THIS TIME WE ARE FORECASTING RECORD OR NEAR RECORD LOW
TEMPERATURES FOR MONDAY MORNING 2/16.
THOSE RECORD LOWS FOR THE 16TH FOLLOW
KACY 3 ABOVE 1888, 1875
KPHL 2 ABOVE 1888
KILG 2 ABOVE 1943
KTTN 1 ABOVE 1888
KGED 10 ABOVE 1987 (SHORTER PERIOD OF RECORD DATING BACK ONLY TO
1948)
KRDG 0 1904
KMPO -14 1943
KABE -7 1943
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO 2 PM EST SUNDAY FOR
PAZ054-055-061-062.
WIND CHILL ADVISORY FROM 6 AM SUNDAY TO 11 AM EST MONDAY FOR
PAZ060>062-101-103-105.
HIGH WIND WARNING FROM 10 PM THIS EVENING TO 2 PM EST SUNDAY
FOR PAZ060-070-071-101>106.
WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR PAZ054-055-
060>062-070-071-101>106.
WIND CHILL ADVISORY FROM 4 PM SUNDAY TO 11 AM EST MONDAY FOR
PAZ070-071-102-104-106.
WIND CHILL WARNING FROM 6 AM SUNDAY TO 11 AM EST MONDAY FOR
PAZ054-055.
NJ...HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO 2 PM EST SUNDAY FOR
NJZ001-007-008.
WINTER WEATHER ADVISORY UNTIL 1 PM EST SUNDAY FOR NJZ001-008-
010-012>014.
WIND CHILL ADVISORY FROM 6 AM SUNDAY TO 11 AM EST MONDAY FOR
NJZ007>009.
HIGH WIND WARNING FROM 10 PM THIS EVENING TO 2 PM EST SUNDAY
FOR NJZ009-010-012>027.
WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR NJZ007-009-
015>027.
WIND CHILL ADVISORY FROM 4 PM SUNDAY TO 11 AM EST MONDAY FOR
NJZ010-012>027.
WIND CHILL WARNING FROM 6 AM SUNDAY TO 11 AM EST MONDAY FOR
NJZ001.
DE...HIGH WIND WARNING FROM 10 PM THIS EVENING TO 2 PM EST SUNDAY
FOR DEZ001>004.
WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR DEZ001.
WIND CHILL ADVISORY FROM 4 PM SUNDAY TO 11 AM EST MONDAY FOR
DEZ001>004.
MD...HIGH WIND WARNING FROM 10 PM THIS EVENING TO 2 PM EST SUNDAY
FOR MDZ008-012-015-019-020.
WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR MDZ008-012.
WIND CHILL ADVISORY FROM 4 PM SUNDAY TO 11 AM EST MONDAY FOR
MDZ008-012-015-019-020.
MARINE...HEAVY FREEZING SPRAY WARNING FROM 8 AM SUNDAY TO 6 AM EST
MONDAY FOR ANZ430-431-450>455.
STORM WARNING FROM 10 PM THIS EVENING TO 6 PM EST SUNDAY FOR
ANZ430-431-450>455.
&&
$$
SYNOPSIS...IOVINO
NEAR TERM...GAINES/MIKETTA
SHORT TERM...MIKETTA
LONG TERM...IOVINO
AVIATION...IOVINO/MIKETTA
MARINE...IOVINO/MIKETTA
TIDES/COASTAL FLOODING...
CLIMATE...
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1132 PM CST THU FEB 12 2015
.UPDATE...
800 PM CST
EVENING UPDATE...
WILL LET WINTER STORM WARNING FOR PORTER COUNTY EXPIRE ON SCHEDULE
THIS EVENING...AS LAKE EFFECT SNOW HAS WEAKENED AND SHIFTED EAST OF
THE AREA. OTHER MINOR CHANGES TO FORECAST WAS TO INCREASE CLOUD
COVER A BIT AND SLOW TEMPERATURE DROP OFF THIS EVENING WITH CIRRUS
AND PATCHY MID CLOUD OVER MUCH OF THE CWA.
HEIGHT RISES AND STRONG SUBSIDENCE IN THE WAKE OF THIS MORNING/S
STRONG SHORT WAVE DISTURBANCE HAS RESULTED IN SURFACE HIGH PRESSURE
SPREADING ACROSS THE MID-MISSISSIPPI VALLEY AND INTO WEST CENTRAL IL
THROUGH EARLY THIS EVENING. WEAKENING/BACKING OF LOW LEVEL WIND
FIELD AND ASSOCIATED WEAKENING CONVERGENCE OVER LAKE MICHIGAN
COMBINED WITH LOWERING SUBSIDENCE INVERSION HAS ALLOWED LAKE EFFECT
SNOW TO WEAKEN FROM STRONG SINGLE-BAND EARLIER THIS AFTERNOON TO
MUCH LESS INTENSE PARALLEL BAND SHOWERS FOCUSED LARGELY INTO MI/IN
EAST OF PORTER COUNTY AT 755 PM. OTHER THAN A FEW LINGERING FLURRIES
SNOW HAS ENDED...AND THE WINTER STORM WARNING WILL EXPIRE AT 8 PM
CST AS PLANNED.
OTHERWISE...CONSIDERABLE MID/HIGH CLOUD COVER...THOUGH THIN IN
SPOTS...HAS RESULTED IN TEMPS FALLING OFF MORE SLOWLY THAN FORECAST.
HAVE INCREASED CLOUD COVER AND SLOWED THE TEMPERATURE ROLL OFF
THROUGH THIS EVENING...THOUGH MINS FROM GOING FORECAST STILL LOOK
REASONABLE WITH LIGHT/VARIABLE WINDS IN SURFACE RIDGE AND ANY
CLEARING AFTER MIDNIGHT.
OTHER THAN AFOREMENTIONED TWEAKS TO HOURLY FORECAST GRIDS...NO SIG
CHANGES TO GOING FORECAST FOR TONIGHT.
RATZER
&&
.SHORT TERM...
323 PM CST
TONIGHT THROUGH SUNDAY...
MULTIPLE WINTER CONCERNS OVER THE NEXT FEW DAYS...INCLUDING IN ORDER
OF SIGNIFICANCE:
ANOTHER SIGNIFICANT LAKE EFFECT EVENT APPEARING LIKELY LATE SATURDAY
INTO SUNDAY MORNING...BITTERLY COLD AND WINDY ON VALENTINES DAY AND
NIGHT...SNOW SHOWERS WITH AN ARCTIC FRONT FRIDAY NIGHT...AND
POSSIBLE LIGHT SNOW ON FRIDAY.
TONIGHT...WILL LIKELY BE ABLE TO EXPIRE WSW IN PORTER CO. FOR LAKE
EFFECT AS PLANNED OR POSSIBLY EARLIER AS SNOW SHOWERS CONTINUE TO
WEAKEN IN INTENSITY. ARCTIC HIGH WILL BE OVERHEAD BUT THEN SHIFT
EAST. INCREASING CLOUDS WILL PREVENT A MUCH COLDER NIGHT...THOUGH
LOW MINUS SINGLE DIGITS APPEAR A GOOD BET IN TYPICAL COLDER
SPOTS...WITH POSITIVE SINGLE DIGITS FOR THE REST OF THE AREA.
ON FRIDAY...WARM FRONT TRAILING FROM CLIPPER TRACKING NEAR LAKE
SUPERIOR WILL APPROACH AREA...WITH BROAD ASCENT. HAVE CONCERN WITH
SOME GUIDANCE...NAMELY ECMWF...KEEPING THINGS DRY...BUT NAM/GFS/GEM
FORECAST SOUNDINGS INDICATE ENOUGH SATURATION AND WEAK ASCENT
THROUGH DGZ FROM THE LATE MORNING INTO EARLY AFTERNOON MAINLY NORTH
OF I-80. SHOULD SEE AN AREA OF LIGHT SNOW LIFTING NORTHEAST...WHICH
COULD PUT DOWN A DUSTING IN SPOTS. CONTINUED WARM ADVECTION THROUGH
LATE DAY SHOULD ENABLE TEMPS TO RECOVER INTO 20S AREA WIDE.
FRIDAY NIGHT...VERY IMPRESSIVE ARCTIC FRONT WILL APPROACH AREA LATE
IN THE NIGHT. 850 MB TEMPS OUT AHEAD OF IT ACTUALLY WARM TO LOWER
MINUS SINGLE DIGITS CELSIUS...SO -25 TO -30C AIR BEHIND FRONT WILL
SHARPEN THERMAL GRADIENT AND QUICKLY STEEPEN LAPSE RATES ALONG AND
BEHIND FRONT. ASCENT WILL BE ASSISTED BY VERY POWERFUL MIDLEVEL
SHORT WAVE DIVING SOUTHEASTWARD AND NOSE OF 140 KT UPPER JET. THUS
EXPECT...SNOW SHOWERS TO BREAK OUT MAINLY AFTER MIDNIGHT AND SPREAD
SOUTH. COULD SEE A HALF INCH TO EVEN AS MUCH AS AN INCH IN SPOTS BY
DAYBREAK SATURDAY...ESPECIALLY ALONG/SOUTH OF I-88. BUMPED POPS TO
MID/HIGH CHANCE IN THIS PERIOD. LOW TEMPERATURES ARE LIKELY TO BE
SATURDAY`S HIGH TEMPS WITH MUCH OF THE NIGHT REMAINING NEARLY STEADY
FROM FRIDAY HIGHS UNTIL FROPA.
SATURDAY AND SUNDAY NOT INCLUDING LAKE EFFECT....THE ARCTIC DAM
WILL BREAK ON SATURDAY ...WITH NO MODERATION SHOWN IN GUIDANCE OF
-25 TO -27C 850 MB THERMAL TROUGH ARRIVING BY MID DAY ON
VALENTINES DAY. TEMPERATURES WILL PLUMMET AS STRONG COLD ADVECTION
RAMPS UP. COULD SEE SOME FLURRIES AND SNOW SHOWERS CONTINUE IN THE
MORNING AS LIFT WILL STILL BE PROVIDED FROM POWERFUL UPPER VORT
OVER AREA...THOUGH ARCTIC AIR MASS WILL BECOME INCREASINGLY DRY.
EXTREMELY STRONG PRESSURE GRADIENT BETWEEN 1045 MB+ ARCTIC HIGH
OVER NORTHERN PLAINS AND CLIPPER DEEPENING TO SUB 1000 MB OVER
EASTERN LAKES WILL RESULT IN NNW WINDS GUSTING TO 35 TO 45 MPH AND
POSSIBLY STRONGER ON INDIANA SHORE...WHERE A WIND HEADLINE MAY BE
NEEDED PRIOR TO LAKE EFFECT ISSUES.
WIND CHILL VALUES WILL FALL TO 10 TO 20 BELOW BY LATE AFTERNOON
AND EARLY EVENING. THEN SUBZERO LOWS OUTSIDE OF DOWNTOWN CHICAGO
AND NW INDIANA PLUS ONLY SLOWLY DIMINISHING WINDS WILL YIELD WIND
CHILLS OF 20 TO 30 BELOW LATE SATURDAY NIGHT INTO SUNDAY MORNING.
WILL IN ALL LIKELIHOOD NEED A WIND CHILL ADVISORY STARTING
VALENTINES DAY EVENING. DRESS APPROPRIATE FOR DANGEROUS COLD IF
YOU HAVE DINNER PLANS SATURDAY NIGHT OR CONSIDER SPENDING THE
NIGHT IN WITH YOUR VALENTINE IF YOU HAVEN`T MADE PLANS YET! VERY
GRADUAL WARM ADVECTION ON SUNDAY SHOULD ALLOW HIGHS TO RECOVER TO
THE HIGH SINGLE DIGITS TO MID TEENS.
LAKE EFFECT DISCUSSION FOR SATURDAY INTO SUNDAY...EXTREME 850 MB TO
LAKE DELTA TS OF ABOUT 25C AND EQUILIBRIUM LEVELS AT OR OVER 10KFT
ARE LIKELY TO RESULT IN IMPRESSIVE LAKE EFFECT SNOW BAND(S) DEVELOPING
OVER SOUTHERN LAKE MICHIGAN. WILL STILL NEED TO ASSESS LATEST GUIDANCE
CONCERNING OVERALL EVOLUTION...BUT GUIDANCE HAS REMAINED IN
EXCELLENT AGREEMENT IN SWINGING BOUNDARY LAYER FLOW FROM NNW
SATURDAY AFTERNOON AND EARLY EVENING TO NORTHERLY SATURDAY NIGHT
AND THEN NORTH-NORTHEAST TO NORTHEAST ON SUNDAY. STEADY LAKE SNOWS
COULD GET INTO PORTER COUNTY AS EARLY AS SATURDAY AFTERNOON. I
THEN BROUGHT CATEGORICAL POPS WESTWARD SATURDAY NIGHT INTO SUNDAY
MORNING...WITH ACTIVITY WEAKENING OVER NORTHEAST ILLINOIS DUE TO
SUBSIDENCE AND INCREASINGLY DRY AIR ON SUNDAY AFTERNOON. POTENTIAL
MESOLOW/ENHANCED CONVERGENCE COULD LET SNOW HANG ON A BIT LONGER
THAN WOULD OTHERWISE EXPECT. WILL LIKELY NEED SOME SORT OF LAKE
EFFECT HEADLINE AND WOULDNT BE SURPRISED WITH NEEDING ANOTHER
WARNING FOR AT LEAST PORTER COUNTY GIVEN IMPRESSIVE PARAMETERS. AT
LEAST 6 INCHES OF ACCUMULATION APPEAR POSSIBLE FOR THE NORTHERN
HALF OF PORTER...WHICH COULD BE CONSERVATIVE.
RC
&&
.LONG TERM...
111 PM CST
SUNDAY NIGHT THROUGH THURSDAY...
HIGH AMPLITUDE RIDING REBUILDS YET AGAIN JUST OFFSHORE OF THE
PACIFIC COASTLINE FOR THE EARLY HALF OF THE WEEK. AFTER SOME
RECOVERY ON MONDAY...THIS PATTERN SUGGESTS WE WILL REMAIN IN A
COLDER NW FLOW PATTERN WITH BELOW NORMAL TEMPERATURES AN OCCASIONAL
CHANCE FOR LIGHT SNOW.
SURFACE HIGH PRESSURE QUICKLY SHIFTS EAST ON SUNDAY NIGHT OPENING
THE DOOR TO A SERIES OF DISTURBANCES IN WEST/NORTHWEST FLOW ALOFT.
WARM AIR ADVECTION BEHIND THE DEPARTING HIGH MAY TRIGGER SOME LIGHT
SNOW IN OUR WESTERN AREAS SUNDAY NIGHT...BUT THESE DISTURBANCES LOOK
TO SPLIT THE AREA WITH ONE WAVES DIGGING SOUTH CLOSER TO THE
LINGERING LOW LEVEL BAROCLINIC ZONE THAT BLASTED THROUGH THE AREA ON
SATURDAY. SOME OF THIS MAY GRAZE OUR SOUTHERN COUNTIES FROM LASALLE
EAST TO BENTON COUNTY INDIANA DURING THE DAY MONDAY. THE OTHER
PACIFIC WAVE BY THIS TIME WOULD HAVE TAKEN A
MORE ARCTIC ROUTE GRAZES OUR NORTHERN ZONES AND LARGELY PASSES BY TO
OUR NORTH. THAT SAID...LIGHT ISENTROPIC LIFT AHEAD OF THE NORTHERN
SHORTWAVE KEEPS CHANCES FOR LIGHT SNOW GOING FOR NORTH CENTRAL
ILLINOIS MONDAY...THEN ALONG AND NORTH OF I-88 MONDAY NIGHT. MODELS
ARE NOT IN GREAT AGREEMENT ABOUT ACCUMULATING SNOW WITH THE SPLIT
ENERGY ON MONDAY/MONDAY NIGHT...THUS SOME LOW CHANCE POPS CARRIED.
SHOULD BE A CLOUDIER PERIOD NONETHELESS.
THE PATTERN THEN BECOMES HIGHLY AMPLIFIED OVER OUR REGION WITH LOW
PRESSURE OVER HUDSON BAY WHILE A DEEP UPPER TROUGH DIGS INTO THE
FOUR CORNERS REGION/DESERT SOUTHWEST. THE LEADING EDGE OF A COLD
FRONT BEGINS OOZING IN TUESDAY. THESE TWO SYSTEMS EVENTUALLY MERGE
INTO A UNIFIED TROUGH WHICH PASSES OVER THE REGION ON LATER TUESDAY
AND TUESDAY NIGHT. MUCH OF THE FORCING WITH THIS WILL BE SOUTH OF
THE AREA LEAVING US COLD AND DRIER WITH SOME LAKE EFFECT SNOWS IN
NORTHWEST INDIANA. PICTURE GETS A BIT MORE MUDDLED SNOWFALL WISE MID
TO LATE WEEK LEAVING US SUSCEPTIBLE TO CLIPPERS...BUT HAVE HIGHER
CONFIDENCE IN CONTINUED COLDER WEATHER AND SOME LAKE EFFECT SNOW.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* CHANCE OF FLURRIES/LIGHT SNOW AND TEMPORARY MVFR CONDITIONS MID
FRIDAY AFTERNOON THROUGH EARLY EVENING.
* HIGHER CHANCE FOR A PERIOD OF SNOW SHOWERS REDUCING VISIBILITY
TO IFR LATE FRIDAY NIGHT INTO EARLY SATURDAY MORNING.
* GUSTY NORTHWEST WINDS DEVELOPING LATE FRIDAY NIGHT BECOMING EVEN
STRONGER EARLY SATURDAY MORNING WITH GUSTS TO AT LEAST 35 KNOTS.
//DISCUSSION...UPDATED 06Z...
A HIGH PRESSURE RIDGE WILL MOVE EAST OF THE AREA THROUGH FRIDAY
MORNING WITH SOUTHWEST WINDS TO KICK IN AND STRENGTHEN INTO THE
AFTERNOON. GUSTS SHOULD BE PERIODICALLY IN THE 18-25KT RANGE.
CLOUDS WILL GRADUALLY THICKEN AND LOWER DURING THE MORNING AND
EARLY AFTERNOON. UPSTREAM OBSERVATIONS INDICATE SOME LIGHT SNOW /
FLURRIES WITHIN THIS AREA OF ASCENT AND EXPECT SIMILAR ACROSS
EASTERN WI AND PROBABLY NORTHEAST IL AND NORTHWEST IN FRIDAY
AFTERNOON AND EARLY EVENING. A BRIEF PERIOD OR TWO OF MVFR
CONDITIONS IS POSSIBLE...NAMELY CIGS. LIMITED DEEP LAYER
SATURATION SHOULD PREVENT ANY CONDITIONS WORSE THAN THIS DURING
THAT TIME.
A STRONG JET STREAM BUCKLE WILL DRIVE AN ARCTIC COLD FRONT ACROSS
THE AREA LATE FRIDAY NIGHT SHIFTING WINDS NORTHWEST AND INCREASING
SPEEDS. THESE WILL LIKELY JUMP UP EVEN FURTHER JUST AFTER SUNRISE
SATURDAY. IN THE FEW HOUR WINDOW FOLLOWING THE FRONTAL
PASSAGE...THE ATMOSPHERE LOOKS PRIMED FOR AT LEAST SCATTERED SNOW
SHOWERS. GIVEN THE CONCURRENT WIND SPEEDS...IFR VISIBILITY WOULD
BE FAVORED DIRECTLY UNDER ANY OF THESE SNOW SHOWERS. LIGHT
ACCUMULATIONS OF UNDER ONE INCH ARE EXPECTED WITH THESE.
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* LOW-MEDIUM IN SNOW POTENTIAL AND INTENSITY FRIDAY AFTERNOON AND
ATTENDANT MVFR CIGS POTENTIAL.
* MEDIUM-HIGH IN SNOW SHOWER POTENTIAL LATE FRIDAY NIGHT INTO
EARLY SATURDAY. MEDIUM-HIGH ON BRIEF PERIOD OF IFR. LOW ON EXACT
TIMING.
* HIGH IN WINDS.
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...PRIMARILY VFR. STRONG/GUSTY NORTHWEST WINDS.
SUNDAY...CHANCE OF MVFR CIGS/FLURRIES.
MONDAY THROUGH WEDNESDAY...PRIMARILY VFR.
MTF/IZZI
&&
.MARINE...
425 PM CST
HIGHER WIND SPEEDS STILL IN PLACE ACROSS THE ENTIRE LAKE AS A
FAIRLY TIGHT PRESSURE GRADIENT REMAINS OVERHEAD...WHILE HIGH
PRESSURE MOVES SOUTHEAST OVER THE REGION. DO EXPECT THE GRADIENT
TO RELAX RATHER QUICKLY THIS EVENING...AND WITH WINDS DIMINISHING
WHILE BECOMING MORE WESTERLY. THESE LIGHTER WINDS WILL BE ON THE
BRIEF SIDE AS SOUTHWEST WINDS INCREASE ONCE AGAIN ON FRIDAY OUT
AHEAD OF AN APPROACHING LOW FROM THE NORTHWEST. EXPECT WINDS TO 30
KT ONCE AGAIN ON FRIDAY...BUT BECOMING MORE WEST AND NORTHWEST BY
FRIDAY EVENING. DEPARTING LOW PRESSURE AND THEN BUILDING HIGH
PRESSURE FROM THE NORTHWEST WILL ALLOW FOR WINDS TO CONTINUE
INCREASING LATE FRIDAY NIGHT INTO SATURDAY MORNING...WITH GALES
APPEARING LIKELY. HAVE NORTHWEST TO NORTH GALES TO 45 KT MENTIONED
IN THE FORECAST...BUT COULD SEE AN UPWARD TREND OCCURRING WITH
STORM FORCE WINDS DEFINITELY NOT OUT OF THE QUESTION DURING THE
DAY ON SATURDAY. A GALE WATCH HAS BEEN ISSUED FOR THE OPEN WATERS
AND THE NEARSHORE WATERS DURING THIS TIME...WITH WINDS DIMINISHING
SATURDAY NIGHT.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 AM FRIDAY.
GALE WATCH...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...6 AM
SATURDAY TO 3 AM SUNDAY.
GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...3 AM SATURDAY TO 3 AM
SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1107 PM CST Thu Feb 12 2015
.UPDATE...
ISSUED AT 830 PM CST THU FEB 12 2015
Arctic high pressure centered over our area early this evening
has allowed winds to subside with an increase in cirrus from
northwest to southeast as our next weather system moves into
the Missouri River Valley. Early evening temperatures have
fallen off but not as quickly as thought as the thicker cirrus
has kept the numbers in check early this evening. Weather system
to our west responsible for the increase in clouds this evening
was producing some scattered areas of light snow over west central
and southwest Iowa this evening with both the HRRR and Rapid
Refresh models keeping the light snows to our west before it
diminishes as it heads east into extreme west central IL Friday
morning. Current forecast has this well handled this evening, so
other than the usual tweaks to the early evening temperatures,
no other changes were needed that would require an updated
ZFP at this time.
&&
.SHORT TERM...(Tonight)
ISSUED AT 252 PM CST THU FEB 12 2015
Latest water vapor imagery shows broad northwesterly flow over the
Midwest, with numerous weak short-waves embedded within the pattern.
Next wave of interest to the weather across central Illinois is
currently located over western North Dakota and is expected to track
S/SE to the Missouri/Iowa border by 12z. 20z/2pm surface obs show
light snow falling along/ahead of this feature across the Dakotas.
As the wave tracks southeastward, it is expected to shear/weaken
with time, resulting in only very minor lift arriving across the
western KILX CWA late tonight. With forecast soundings remaining
unsaturated, have opted to remove mentionable PoPs overnight in
favor of just a chance of flurries along/west of a Galesburg to
Jacksonville line. Given initially mostly clear skies and
diminishing winds, temperatures will quickly bottom out in the
single digits and teens by mid to late evening. As clouds increase
and a light southerly return flow begins to develop late, readings
will likely rise a couple of degrees toward dawn, especially west of
the I-55 corridor.
&&
.LONG TERM...(Friday through Thursday)
ISSUED AT 252 PM CST THU FEB 12 2015
An extended period of colder to much colder than normal conditions
is expected across central and southeast Illinois, lingering at
least through the end of next week. Persistent ridging up to Pacific
coast into Alaska and downstream troffing over at least the eastern
half of North America will help ensure this fact. Periodic waves in
the predominantly northwest upper-level level flow will be
accompanied by reinforcing shots of cold air, and possibly some
light snow or flurries. The upper troffing will dig enough to our
west by next Monday/Tuesday to at least pose the risk of a stronger
system moving our way, but recent model trends have been pushing
this system further south.
Temperatures will briefly moderate Friday ahead of our next major
clipper type wave for Saturday. A weaker wave will pass mainly to
our north of Friday, which may bring some flurries to northern
sections of the forecast area, but no significant snowfall is
anticipated. Saturday`s clipper is potent, but will pass far enough
to our north/east to be a minimal snowfall threat. The more notable
impact with its passage will be winds gusting over 30 mph Saturday
into Saturday night. These winds will help usher in bitterly cold
sub-zero wind chill temperatures for the entire forecast area
Saturday night into Sunday.
A few waves in the broader North American trof expected to be in
place for early next week will come toward the area from a more
westerly or even southwesterly direction. This track should allow
these waves to have more moisture to work with as far as being snow
producers. However, model trends have pushed the main baroclinic
zone/storm track much further south, which should greatly diminish
the local threat of significant snow accumulation Monday into
Tuesday. Since the system/systems with the early week waves has/have
the potential to be significant, will continue to keep a close eye
on later guidance. However, at this point, the model trends are
looking more optimistic as far as keeping the significant
precipitation away from the forecast area.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 1100 PM CST THU FEB 12 2015
VFR conditions are expected to continue through Friday evening.
High pressure was drifting slowly away from our area late this
evening while a weak weather disturbance over the Missouri Valley
has produced some light snow over western Iowa into northwest
Missouri. We have seen an increase in mid and high level clouds
from the northwest this evening and these clouds are expected to
hold overnight. As a weather disturbance passes to our north Friday
clouds will drop to low VFR in a few locations with a few of the
models indicating the potential for a few flurries, mainly across
our northern TAF sites late tomorrow morning into the afternoon
hours before the disturbance shifts off to our east by evening.
Surface winds will be light and variable tonight and then shift
into a southerly direction at 10 to 15 kts Friday morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...Barnes
LONG TERM...Bak
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS DES MOINES IA
407 AM CST FRI FEB 13 2015
.SHORT TERM /TODAY/...
ISSUED AT 345 AM CST FRI FEB 13 2015
GOOD WAA ADVECTION IS UNDERWAY...BUT MOISTURE IS LACKING AND THE
FORCING IS RELATIVELY WEAK...THOUS THE SNOW BAND IS NOT PRODUCING
MUCH. MEASURABLE SNOW FROM HERE ON OUT IS PRETTY MUCH OUT OF THE
QUESTION AND WILL LIKELY TAKE OUT GRADUALLY OUT OF THE CWA AS
FLURRIES TEMPS TODAY WILL MODERATE WITH THE SOUTHWEST HALF OF THE
CWA MAKING IT JUST ABOVE FREEZING. SOUTH TO SOUTHWEST WINDS ARE
FAVORABLE...BUT NOT STRONG ENOUGH TO REALLY MIX DOWN THE WARMER AIR.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 345 AM CST FRI FEB 13 2015
THE LONG TERM IS INTERESTING. IN GENERAL THE PATTERN CHANGES
LITTLE WITH A VERY AMPLIFIED UPPER RIDGE ACROSS THE WEST AND A
TROUGH OVER THE GREAT LAKES AND THE EAST. THE UPPER MIDWEST GET
CAUGHT IN THE MIDDLE WITH A PARADE OF SHORT WAVES BUT MOISTURE
ISNT GREAT AND FORCING IS RATHER HIT OR MISS. WHAT IS EVIDENT IS
THAT THE PATTERN WE ARE IN WILL BE COLD. AFTER TODAY WE ARE NOT
GOING TO SEE TEMPS MUCH ABOVE FREEZING FOR A WHILE.
TONIGHT INTO SATURDAY A TROUGH SWEEPS OUT OF ONTARIO ACROSS
EASTERN MN AND WISCONSIN. FURTHER WEST A SUBTLE WAVE DRIFTS ACROSS
THE REGION AHEAD OF THE TROUGH. THERE IS THE POSSIBILITY OF A
BRIEF SHOT OF LIGHT SNOW ACROSS THE WEST SATURDAY NIGHT AND AREA
WIDE SUNDAY WITH THE TROUGH PASSAGE. MOST LOCATIONS WEST WILL SEE
AN INCH TO AN INCH AND A HALF WHILE LOCATIONS EAST WILL SEE JUST
SLIGHTLY LESS. HOWEVER AS THE TROUGH COMES DOWN AND BRINGS DOWN A
SHOT OF VERY COLD AIR...WINDS ACROSS NORTHERN AND EASTERN IOWA
WILL CRANK UP FOR SATURDAY. WINDS WILL GENERALLY BE 15 TO 25 MPH
WITH 20 TO 30 MPH WINDS AND HIGHER GUSTS ACROSS THE NORTH AND
EAST. SATURDAY NIGHT LOOKS VERY COLD. WINDS WILL BE DIMINISHING
BUT WIND CHILLS WILL APPROACH OR EXCEED WIND CHILL ADVISORY
CRITERIA THOUGH IT MAY NOT LAST LONG OR BE OVER A WIDESPREAD AREA.
THIS WILL NEED TO BE MONITORED.
SUNDAY AND SUNDAY NIGHT ANOTHER WAVE PASSES OVER IOWA BRINGING
ANOTHER SHOT FOR LIGHT SNOW. THE MODELS ARE HAVING A TOUGH TIME
RESOLVING THIS THOUGH AND RIGHT NOW CANNOT AGREE ON WHETHER IT
WILL BE LITTLE MORE THAN FLURRIES OR IF LIGHT AMOUNTS ARE MORE
LIKELY. WE GET INTO SOME VERY WEAK WARM ADVECTION LATE SUNDAY AND
MONDAY WHERE THE SOUTHWEST MAY GET INTO THE LOWER 30S. THE REST OF
THE STATE WILL STILL BE IN THE 20S THOUGH.
ANOTHER SHORTWAVE PASSES BY MONDAY INTO TUESDAY AND APPEARS DRY
BUT WILL USHER IN ANOTHER SHOT OF COLD AIR SO ITS BACK TO TEMPS IN
THE SINGLE DIGITS AND TEENS WITH LOWS BELOW ZERO NORTHEAST TO THE
TEENS SOUTHWEST. THE PATTERN REPEATS THROUGH THE REST OF THE WEEK
WITH SLIGHTLY WARMER TEMPS AGAIN THURSDAY INTO FRIDAY. THE WARM UP
ON FRIDAY COULD BE SIGNIFICANT BUT WILL BE SHORT LIVED...AND IF
THE EURO IS RIGHT...WILL BE SHORT LIVED.
&&
.AVIATION...13/06Z
ISSUED AT 1054 PM CST THU FEB 12 2015
LIGHT SNOW MAKING LITTLE EAST PROGRESS WITH FORCING AND LIFT
CONCENTRATED WEST OF I35 AS LACK OF SATURATION EAST OF I35
CONTINUES. HRRR SHOWS DRAMATIC WEAKENING OF BAND...SO ALONG WITH
CURRENT TRENDS HAVE CUT BACK ON COVERAGE AND LIMITED VSBY
REDUCTIONS AND CIG LOWERING THROUGH 12Z. SOME BKN MID LEVEL CLOUDS
REMAIN THROUGH DAY PRIOR TO ARRIVAL OF ARCTIC BOUNDARY AND
POSSIBLE -SN AGAIN TOWARD END OF PERIOD AS FRONT CROSSES THE
REGION BY 14/06Z. STRONG NW WINDS TO DEVELOP LATE IN THE PERIOD
MAINLY AFT 14/03Z NORTH SECTIONS. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MS
LONG TERM...FAB
AVIATION...REV
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1053 PM CST THU FEB 12 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 350 PM CST THU FEB 12 2015
LIGHT SNOW IS DEVELOPING ACROSS SOUTH DAKOTA AHEAD OF A SHORT WAVE
DROPPING SOUTHEAST THROUGH NORTH DAKOTA. THE VERTICAL ASCENT IS
BEING ENHANCED BY MID LEVEL THETA E ADVECTION IN ADDITION TO THE
KINEMATICS ASSOCIATED WITH THE SHORT WAVE. THIS FORCING WILL ARRIVE
ACROSS NORTHWEST IOWA BY LATE THIS AFTERNOON AND ARRIVE INTO THE
CENTRAL PORTION OF THE STATE BY THIS EVENING. SOME DISCONTINUITY
BETWEEN THE PERIOD OF PEAK FORCING AND TIMING OF MAX SATURATION
THROUGH THE COLUMN. THE DISCONTINUITY IS DUE TO THE INITIAL FORCING
BEING SPENT TRYING TO SATURATE THE DRY LOW LEVELS LEFT OVER FROM THE
DEPARTING HIGH PRESSURE SYSTEM. LIGHT SNOW IS LIKELY WITH MINOR
ACCUMULATIONS...GENERALLY ONE HALF INCH OR LESS. WINDS WILL SWITCH
TO THE SOUTH OVERNIGHT AS THE HIGH DEPARTS. TEMPERATURES WILL BE
STEADY TO RISING AFTER 06Z.
.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 350 PM CST THU FEB 12 2015
ALTHOUGH THERE MAY BE SOME MINOR MODERATION LATE...THERE IS STILL NO
SIGN OF SIGNIFICANT PATTERN CHANGE THROUGH THE PERIOD WITH MEAN
TROUGH INTO THE CENTRAL OR ERN CONUS. TEMPS WILL BRIEFLY REBOUND
BACK TO NORMAL FRI...WITH LINGERING EARLY MORNING WARM ADVECTION LIGHT
SNOW POSSIBLY FAR NE...BUT A SHORT WAVE/PV ANOMALY PASSAGE MUCH
LIKE YESTERDAY WILL DRIVE ANOTHER COLD FRONT AND SUBSEQUENT SURGE
OF ARCTIC AIR THROUGH THE STATE INTO THE NIGHT. TRAILING LOBE OF
FORCING MAY PRODUCE SOME TOKEN LIGHT SNOW BUT FORCING AND MOISTURE
IS DISJOINTED AND NEVER REALLY PHASES. ICE BEARING LIFT IS FAIRLY
TYPICAL ALOFT AT ONSET BUT FAVORED DENDRITIC GROWTH ZONE /DGZ/
TEMPS CRASH WITH COLD AIR ADVECTION INTO EARLY SAT MORNING WITH
STRATUS POTENTIALLY PRODUCING LOW BASED LIGHT SNOW OR FLURRIES.
MSLP GRADIENT AND MIXED LAYER WINDS WILL BE PUSHING ADVISORY
CRITERIA...MAINLY SUSTAINED /26KTS/...DURING THE MORNING NE. SAT
NIGHT LOOKS QUITE COLD WITH READINGS BELOW ZERO NE TWO-THIRDS
ALTHOUGH INCREASING CLOUDINESS WITH WEAK WARM ADVECTION MAY TEMPER
THINGS SOMEWHAT.
RECENT ECMWF/GFS TRENDS NOW SUGGEST NRN STREAM WILL BE MORE DOMINATE
EARLY NEXT WEEK WHICH LEADS TO TWO SENSIBLE WEATHER CHANGES. THE
FIRST WILL BE THE ADDITION OF LOW END POPS AROUND SUN...AT LEAST FOR
A START...WITH MAIN FOCUS NORTH. FORCING IS FAIRLY DEEP WITH
CERTAINLY ADEQUATE MOISTURE FOR PRECIP. QPF AMOUNTS ARE FAIRLY LOW
WITH THIS SYSTEM...WHICH WOULD BE EXPECTED IN THIS COLD
AIRMASS...HOWEVER SNOW RATIOS MAY BE GREATLY INFLATED WITH DGZ DEPTH
AROUND 10KFT AND BRIEFLY PHASED WITH ZONE OF MAX OMEGA. COBB SNOW
RATIOS REFLECT THIS AS WELL...JUMPING INTO THE 20S. IF CURRENT
TRENDS CONTINUE SUN WILL CERTAINLY NEED TO BE WATCHED WITH HIGHER
POPS AND AMOUNTS NEEDED.
THIS MORE NRN STREAM EMPHASIS HAS ALSO LOWERED HEIGHTS AND PUSHED
THE PREVIOUSLY ANTICIPATED MON/MON NIGHT SOUTHERN SNOW FARTHER
AWAY FROM FORECAST AREA. THERE ARE STILL LOW POPS IN THE
FORECAST...BUT THIS IS LIKELY MORE A REFLECTION OF 00Z ECMWF
INFLUENCE THAN ANYTHING AND COULD VERY WELL BE LESSENED FURTHER OR
REMOVED ALTOGETHER IF THE 12Z GFS HOLDS TRUE AND 12Z ECMWF GETS
INTO THE MIDNIGHT SHIFT FORECAST. OTHERWISE THE REMAINDER OF THE
FORECAST LOOKS DRY WITH PERSISTENT BELOW NORMAL TEMPERATURES WITH
JET STAYING AWAY FROM IA IN HEART OF TROUGH THROUGH AT LEAST THU.
ALTHOUGH THE 12Z ECMWF IS LESS AGGRESSIVE...POPS MAY NEED TO BE
ADDED AROUND WED IF THE MORE BULLISH 12Z GFS MAINTAINS ITSELF.
&&
.AVIATION...13/06Z
ISSUED AT 1054 PM CST THU FEB 12 2015
LIGHT SNOW MAKING LITTLE EAST PROGRESS WITH FORCING AND LIFT
CONCENTRATED WEST OF I35 AS LACK OF SATURATION EAST OF I35
CONTINUES. HRRR SHOWS DRAMATIC WEAKENING OF BAND...SO ALONG WITH
CURRENT TRENDS HAVE CUT BACK ON COVERAGE AND LIMITED VSBY
REDUCTIONS AND CIG LOWERING THROUGH 12Z. SOME BKN MID LEVEL CLOUDS
REMAIN THROUGH DAY PRIOR TO ARRIVAL OF ARCTIC BOUNDARY AND
POSSIBLE -SN AGAIN TOWARD END OF PERIOD AS FRONT CROSSES THE
REGION BY 14/06Z. STRONG NW WINDS TO DEVELOP LATE IN THE PERIOD
MAINLY AFT 14/03Z NORTH SECTIONS. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DONAVON
LONG TERM...SMALL
AVIATION...REV
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
936 PM EST SAT FEB 14 2015
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 330 PM EST SAT FEB 14 2015
DANGEROUS COLD IS IN STORE TONIGHT AND SUNDAY MORNING. WIND CHILLS
OF 20 TO 35 BELOW WILL RESULT IN FROSTBITE TIMES OF 15 MINUTES OR
LESS.
STRONG WINDS AND BLOWING SNOW WILL SUBSIDE THIS EVENING. HEAVY SNOW
SHOWERS NEAR LAKE MICHIGAN WILL END BY MIDNIGHT. WIND CHILLS WILL
RECOVER SUNDAY AFTERNOON WITH LIGHT WINDS AND BRIGHT SUNSHINE BUT
HIGH TEMPERATURES WILL BE ONLY IN THE SINGLE DIGITS.
TEMPERATURES WILL CONTINUE TO AVERAGE WELL BELOW FOR THE NEXT WEEK
OR MORE. ADDITIONAL PERIODS OF SNOW ARE LIKELY... HEAVY AT TIMES
NEAR LAKE MICHIGAN.
&&
.UPDATE...
ISSUED AT 936 PM EST SAT FEB 14 2015
WE HAVE EXTENDED THE WINTER STORM WARNING ALONG THE COASTLINE
UNTIL 4 AM SUNDAY MORNING. THE BAND OF LAKE EFFECT COMING INTO THE
LAKESHORE COUNTIES HAS BEEN SOMEWHAT STATIONARY OVER THE LAST
COUPLE OF HOURS. IT IS GOING TO TAKE A LITTLE LONGER THAN
PREVIOUSLY EXPECTED TO MOVE OFFSHORE. WINDS ARE COMING DOWN...BUT
VISIBILITIES ARE STILL QUITE LOW WITH SOME BLOWING SNOW STILL
LIKELY OCCURRING. ONCE THE BAND MOVES OFFSHORE...VISIBILITIES WILL
IMPROVE AND BLOWING AND DRIFTING SHOULD END.
UPDATE ISSUED AT 736 PM EST SAT FEB 14 2015
WE ARE ISSUING AN UPDATE EARLY THIS EVENING TO TRANSITION ALL
INLAND COUNTIES OVER TO A WIND CHILL WARNING. THE WINTER STORM
WARNING WILL CONTINUE FOR NOW UNTIL THE EXPIRATION TIME OF 10 PM
THIS EVENING...DEPENDING ON HOW FAST/SLOW THE LAST SNOW BANDS MOVE OFFSHORE.
THE MAIN HAZARD FOR INLAND AREAS HAS NOW TRANSITIONED TO THE
DANGEROUS WIND CHILLS EXPECTED TONIGHT AND TOMORROW MORNING. THE
SNOW SHOWERS HAVE COME TO AN END INLAND...AND WINDS HAVE
DIMINISHED ENOUGH TO ALLOW THE BLOWING AND DRIFTING TO DIMINISH.
WIND CHILLS CONTINUE TO LOOK LIKE THEY WILL APPROACH 30 BELOW AT
MOST INLAND LOCATIONS WITH A WIND REMAINING UP AND THE COLD ARCTIC
AIR STILL MOVING IN.
WE WILL LIKELY DO THE SAME THING FOR THE LAKESHORE COUNTIES ONCE
THE SNOW SHOWERS ARE PUSHED OFFSHORE BY THE DEVELOPING LAND BREEZE
COMPONENT. WE DO NOT WANT TO DO IT YET AS MANY COMMUNITIES/
COUNTIES ALONG THE LAKESHORE ARE HAVING TROUBLES WITH MANY ROADS
BEING DRIFTED SHUT STILL WITH THE FALLING SNOW AND BETTER WINDS THERE.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 330 PM EST SAT FEB 14 2015
ATTENTION SHIFTS FROM SNOW/BLOWING SNOW AND HIGH WINDS TO EXTREME
COLD TONIGHT. THE ONGOING HEADLINES WILL REMAIN IN EFFECT FOR A FEW
MORE HOURS TO COVER THE PERIODIC WHITEOUT/GROUND BLIZZARD SITUATION
THEN BECOME WIND CHILL HEADLINES.
WIND GUSTS ARE PEAKING NOW THROUGH ABOUT 5 PM BUT ARE EXPECTED TO
SHUT DOWN PRETTY QUICK THIS EVENING AS THE BOUNDARY LAYER DECOUPLES
SHORTLY AFTER 7 PM. HOWEVER SUSTAINED WINDS DO STAY UP MUCH OF THE
NIGHT WITH SPEEDS OF 10 TO 20 MPH. GUIDANCE HAS BEEN CONSISTENT
SHOWING AIR TEMPS FALLING TO 5 TO 15 BELOW WHICH SUPPORTS MIN WIND
CHILLS REACHING 25 BELOW OR LOWER OVER MUCH OF THE AREA.
INLAND CLEARING/LAND BREEZE FORMATION THIS EVENING WILL ASSIST IN
SENDING LAKESHORE SNOWS OFFSHORE. LATEST HRRR HAS THE LAKE EFFECT
SNOW BANDS SHIFTING OFFSHORE OF MKG AROUND 7 PM...HOLLAND AROUND 8
PM... SOUTH HAVEN AROUND 10 PM... AND LUDINGTON AROUND MIDNIGHT.
SURFACE RIDGING BUILDS IN QUICKLY ON SUNDAY CAUSING WINDS TO LIGHTEN
UP CONSIDERABLY. THUS WIND CHILLS RECOVER SUBSTANTIALLY IN THE
AFTERNOON UNDER BRIGHT SKIES IN FRIGID ARCTIC AIR MASS.
HI RES MODELS BEYOND 24 HOURS INDICATE MESOLOW CIRCULATION WILL
DEVELOP OVER SRN OR CNTRL LAKE MICHIGAN WITHIN MID LAKE CONVERGENCE
BAND. THIS SEEMS REASONABLE GIVEN VERY COLD/CLEAR SYNOPTIC PATTERN
AND STRONG LAND BREEZE CIRCULATIONS ON ALL SIDES OF LK MI. THIS
FEATURE SHOULD EVENTUALLY COME ONSHORE NORTH OF HOLLAND LATE SUNDAY
NIGHT OR MONDAY MORNING AS SYNOPTIC FLOW TURNS SOUTHWESTERLY.
MID LAKE MESO FEATURES CAN PRODUCE EXCESSIVE SNOW RATES... SO THIS
WILL NEED TO BE CLOSELY WATCHED. ALSO DEEPER MOISTURE ARRIVES ABOUT
THE SAME THIS FEATURE COMES ONSHORE AND THE DGZ RETURNS BACK INTO
THE CLOUD LAYER DUE TO WARMING. ADVISORY/WARNING MAY BE NEEDED
MON/MON NGT FOR WEST CENTRAL LWR MI INCLUDING MKG/LDM AREAS.
POSSIBLY BIV/GRR AS WELL DEPENDING ON MEAN LOW LEVEL WIND DIRECTION.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 330 PM EST SAT FEB 14 2015
THE LONG RANGE FORECAST PERIOD CONTINUES TO LOOK VERY COLD AND
SNOWY. ANOTHER SURGE OF ARCTIC AIR WILL BEGIN TO ARRIVE LATE TUESDAY
THROUGH TUESDAY NIGHT BEHIND THE ARCTIC COLD FRONT. MAX TEMPS
WEDNESDAY THROUGH FRIDAY WILL STRUGGLE TO REACH THE UPPER SINGLE
DIGITS TO LOWER TEENS.
THE ARCTIC FRONT WILL BRING POTENTIAL FOR A ROUND OF SNOW SHOWERS
TUESDAY WITH LAKE EFFECT SNOW SHOWERS ANTICIPATED MID TO LATE WEEK.
SIGNIFICANT HEAVY LAKE EFFECT SNOW EVENTS ARE NOT ANTICIPATED BUT
SEVERAL INCHES OF VERY DRY FLUFFY SNOW ARE POSSIBLE THROUGH MID TO
LATE WEEK.
WIND CHILL VALUES WILL BE QUITE COLD AS WELL MID TO LATE WEEK. WIND
CHILL READINGS WEDNESDAY THROUGH FRIDAY MORNING COULD BE COLDER THAN
15 DEGREES BELOW ZERO... ESPECIALLY OVER THE INTERIOR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 645 PM EST SAT FEB 14 2015
FOR THE MOST PART THE SNOW PART OF THIS EVENT IS ENDED AT MOST OF
THE TAF SITES...ONLY MKG WILL CONTINUE TO SEE SNOW SHOWERS TILL
AROUND 06Z-08Z. SURFACE WINDS WILL DIMINISH TO NORTH AROUND 10
KNOTS BY 06Z AND REMAIN SO THROUGH SUNDAY AFTERNOON.
ALL OF THE MODELS ARE EMPHATIC ABOUT BRINGING DRY AIR DOWN FROM
THE NORTH CLEARING BETWEEN 03Z AND 05Z. SATELLITE IMAGES GIVE THE
MODEL FORECAST STRONG SUPPORT AS IR LOOPS SHOW THIS ALREADY
HAPPENING. AFTER THAT SKIES REMAIN CLEAR MOST OF THE DAY ON
SUNDAY. THIS HAPPENS DUE TO WINDS THROUGH 10000 FT AGL TURNING
NORTH BY 03Z THEN NORTH NORTHEAST BY 09Z AND REMAINING SO THROUGH
MOST OF SUNDAY AS SURFACE HIGH PRESSURE MOVES INTO THE AREA. ALL
OF THIS WILL ALSO MEANS WILL DIMINISH CONSIDERABLY OVER THE NEXT
FEW HOURS. BY 06Z ALL BUT MKG SHOULD BE CLEAR WITH A NORTH WIND
AROUND 10 KNOTS.
MUSKEGON WILL REMAIN CLOSE TO THE EDGE OF THE ACTIVE SNOW BAND
UNTIL AROUND 06Z AFTER THAT IT SHOULD PUSH OFF SHORE. MY TAF MAY
HAVE THE SNOW LASTING TO LONG THERE...BUT WE WILL MONITOR THAT
OVER THE NEXT FEW HOURS.
&&
.HYDROLOGY...
ISSUED AT 1115 AM EST SAT FEB 14 2015
THE CORE OF THE WINTER SEASONS COLDEST AIR WILL CONTINUE TO MOVE IN
THROUGH THE DAY TODAY INTO SUNDAY. TEMPERATURES WILL CONTINUE TO
TUMBLE.
THEREFORE...ICE HAS NOT BUDGED AND CONDITIONS ARE STABLE. THERE IS
IS LOW RISK THAT ANY MOVEMENT WILL OCCUR THROUGH NEXT WEEK AS THE
WARMEST HIGH TEMPERATURES IN THE NEXT SEVERAL DAYS ONLY REACH INTO
THE 20S. DAILY AVERAGE TEMPERATURES IN THE SINGLE DIGITS AND TEENS
WILL AID IN ADDITIONAL ICE FORMATION OR EXPANSION.
LIQUID CONTRIBUTION WILL REMAIN RATHER LOW DAY TO DAY. ADDITIONAL
ROUNDS OF SNOW ARE POSSIBLE THIS WEEK...ESPECIALLY ALONG THE LAKE
SHORE...BUT NOT MUCH MELTING WILL BE TAKING PLACE THROUGH THE PERIOD.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WARNING UNTIL 4 AM EST SUNDAY FOR MIZ037-043-050-
056-064-071.
WIND CHILL WARNING UNTIL NOON EST SUNDAY FOR MIZ038>040-044>046-
051-052-057>059-065>067-072>074.
LM...NONE.
&&
$$
UPDATE...NJJ
SYNOPSIS...MEADE
SHORT TERM...MEADE
LONG TERM...LAURENS
AVIATION...WDM
HYDROLOGY...JAM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
736 PM EST SAT FEB 14 2015
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 330 PM EST SAT FEB 14 2015
DANGEROUS COLD IS IN STORE TONIGHT AND SUNDAY MORNING. WIND CHILLS
OF 20 TO 35 BELOW WILL RESULT IN FROSTBITE TIMES OF 15 MINUTES OR
LESS.
STRONG WINDS AND BLOWING SNOW WILL SUBSIDE THIS EVENING. HEAVY SNOW
SHOWERS NEAR LAKE MICHIGAN WILL END BY MIDNIGHT. WIND CHILLS WILL
RECOVER SUNDAY AFTERNOON WITH LIGHT WINDS AND BRIGHT SUNSHINE BUT
HIGH TEMPERATURES WILL BE ONLY IN THE SINGLE DIGITS.
TEMPERATURES WILL CONTINUE TO AVERAGE WELL BELOW FOR THE NEXT WEEK
OR MORE. ADDITIONAL PERIODS OF SNOW ARE LIKELY... HEAVY AT TIMES
NEAR LAKE MICHIGAN.
&&
.UPDATE...
ISSUED AT 736 PM EST SAT FEB 14 2015
WE ARE ISSUING AN UPDATE EARLY THIS EVENING TO TRANSITION ALL
INLAND COUNTIES OVER TO A WIND CHILL WARNING. THE WINTER STORM
WARNING WILL CONTINUE FOR NOW UNTIL THE EXPIRATION TIME OF 10 PM
THIS EVENING...DEPENDING ON HOW FAST/SLOW THE LAST SNOW BANDS MOVE OFFSHORE.
THE MAIN HAZARD FOR INLAND AREAS HAS NOW TRANSITIONED TO THE
DANGEROUS WIND CHILLS EXPECTED TONIGHT AND TOMORROW MORNING. THE
SNOW SHOWERS HAVE COME TO AN END INLAND...AND WINDS HAVE
DIMINISHED ENOUGH TO ALLOW THE BLOWING AND DRIFTING TO DIMINISH.
WIND CHILLS CONTINUE TO LOOK LIKE THEY WILL APPROACH 30 BELOW AT
MOST INLAND LOCATIONS WITH A WIND REMAINING UP AND THE COLD ARCTIC
AIR STILL MOVING IN.
WE WILL LIKELY DO THE SAME THING FOR THE LAKESHORE COUNTIES ONCE
THE SNOW SHOWERS ARE PUSHED OFFSHORE BY THE DEVELOPING LAND BREEZE
COMPONENT. WE DO NOT WANT TO DO IT YET AS MANY COMMUNITIES/
COUNTIES ALONG THE LAKESHORE ARE HAVING TROUBLES WITH MANY ROADS
BEING DRIFTED SHUT STILL WITH THE FALLING SNOW AND BETTER WINDS THERE.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 330 PM EST SAT FEB 14 2015
ATTENTION SHIFTS FROM SNOW/BLOWING SNOW AND HIGH WINDS TO EXTREME
COLD TONIGHT. THE ONGOING HEADLINES WILL REMAIN IN EFFECT FOR A FEW
MORE HOURS TO COVER THE PERIODIC WHITEOUT/GROUND BLIZZARD SITUATION
THEN BECOME WIND CHILL HEADLINES.
WIND GUSTS ARE PEAKING NOW THROUGH ABOUT 5 PM BUT ARE EXPECTED TO
SHUT DOWN PRETTY QUICK THIS EVENING AS THE BOUNDARY LAYER DECOUPLES
SHORTLY AFTER 7 PM. HOWEVER SUSTAINED WINDS DO STAY UP MUCH OF THE
NIGHT WITH SPEEDS OF 10 TO 20 MPH. GUIDANCE HAS BEEN CONSISTENT
SHOWING AIR TEMPS FALLING TO 5 TO 15 BELOW WHICH SUPPORTS MIN WIND
CHILLS REACHING 25 BELOW OR LOWER OVER MUCH OF THE AREA.
INLAND CLEARING/LAND BREEZE FORMATION THIS EVENING WILL ASSIST IN
SENDING LAKESHORE SNOWS OFFSHORE. LATEST HRRR HAS THE LAKE EFFECT
SNOW BANDS SHIFTING OFFSHORE OF MKG AROUND 7 PM...HOLLAND AROUND 8
PM... SOUTH HAVEN AROUND 10 PM... AND LUDINGTON AROUND MIDNIGHT.
SURFACE RIDGING BUILDS IN QUICKLY ON SUNDAY CAUSING WINDS TO LIGHTEN
UP CONSIDERABLY. THUS WIND CHILLS RECOVER SUBSTANTIALLY IN THE
AFTERNOON UNDER BRIGHT SKIES IN FRIGID ARCTIC AIR MASS.
HI RES MODELS BEYOND 24 HOURS INDICATE MESOLOW CIRCULATION WILL
DEVELOP OVER SRN OR CNTRL LAKE MICHIGAN WITHIN MID LAKE CONVERGENCE
BAND. THIS SEEMS REASONABLE GIVEN VERY COLD/CLEAR SYNOPTIC PATTERN
AND STRONG LAND BREEZE CIRCULATIONS ON ALL SIDES OF LK MI. THIS
FEATURE SHOULD EVENTUALLY COME ONSHORE NORTH OF HOLLAND LATE SUNDAY
NIGHT OR MONDAY MORNING AS SYNOPTIC FLOW TURNS SOUTHWESTERLY.
MID LAKE MESO FEATURES CAN PRODUCE EXCESSIVE SNOW RATES... SO THIS
WILL NEED TO BE CLOSELY WATCHED. ALSO DEEPER MOISTURE ARRIVES ABOUT
THE SAME THIS FEATURE COMES ONSHORE AND THE DGZ RETURNS BACK INTO
THE CLOUD LAYER DUE TO WARMING. ADVISORY/WARNING MAY BE NEEDED
MON/MON NGT FOR WEST CENTRAL LWR MI INCLUDING MKG/LDM AREAS.
POSSIBLY BIV/GRR AS WELL DEPENDING ON MEAN LOW LEVEL WIND DIRECTION.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 330 PM EST SAT FEB 14 2015
THE LONG RANGE FORECAST PERIOD CONTINUES TO LOOK VERY COLD AND
SNOWY. ANOTHER SURGE OF ARCTIC AIR WILL BEGIN TO ARRIVE LATE TUESDAY
THROUGH TUESDAY NIGHT BEHIND THE ARCTIC COLD FRONT. MAX TEMPS
WEDNESDAY THROUGH FRIDAY WILL STRUGGLE TO REACH THE UPPER SINGLE
DIGITS TO LOWER TEENS.
THE ARCTIC FRONT WILL BRING POTENTIAL FOR A ROUND OF SNOW SHOWERS
TUESDAY WITH LAKE EFFECT SNOW SHOWERS ANTICIPATED MID TO LATE WEEK.
SIGNIFICANT HEAVY LAKE EFFECT SNOW EVENTS ARE NOT ANTICIPATED BUT
SEVERAL INCHES OF VERY DRY FLUFFY SNOW ARE POSSIBLE THROUGH MID TO
LATE WEEK.
WIND CHILL VALUES WILL BE QUITE COLD AS WELL MID TO LATE WEEK. WIND
CHILL READINGS WEDNESDAY THROUGH FRIDAY MORNING COULD BE COLDER THAN
15 DEGREES BELOW ZERO... ESPECIALLY OVER THE INTERIOR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 645 PM EST SAT FEB 14 2015
FOR THE MOST PART THE SNOW PART OF THIS EVENT IS ENDED AT MOST OF
THE TAF SITES...ONLY MKG WILL CONTINUE TO SEE SNOW SHOWERS TILL
AROUND 06Z-08Z. SURFACE WINDS WILL DIMINISH TO NORTH AROUND 10
KNOTS BY 06Z AND REMAIN SO THROUGH SUNDAY AFTERNOON.
ALL OF THE MODELS ARE EMPHATIC ABOUT BRINGING DRY AIR DOWN FROM
THE NORTH CLEARING BETWEEN 03Z AND 05Z. SATELLITE IMAGES GIVE THE
MODEL FORECAST STRONG SUPPORT AS IR LOOPS SHOW THIS ALREADY
HAPPENING. AFTER THAT SKIES REMAIN CLEAR MOST OF THE DAY ON
SUNDAY. THIS HAPPENS DUE TO WINDS THROUGH 10000 FT AGL TURNING
NORTH BY 03Z THEN NORTH NORTHEAST BY 09Z AND REMAINING SO THROUGH
MOST OF SUNDAY AS SURFACE HIGH PRESSURE MOVES INTO THE AREA. ALL
OF THIS WILL ALSO MEANS WILL DIMINISH CONSIDERABLY OVER THE NEXT
FEW HOURS. BY 06Z ALL BUT MKG SHOULD BE CLEAR WITH A NORTH WIND
AROUND 10 KNOTS.
MUSKEGON WILL REMAIN CLOSE TO THE EDGE OF THE ACTIVE SNOW BAND
UNTIL AROUND 06Z AFTER THAT IT SHOULD PUSH OFF SHORE. MY TAF MAY
HAVE THE SNOW LASTING TO LONG THERE...BUT WE WILL MONITOR THAT
OVER THE NEXT FEW HOURS.
&&
.HYDROLOGY...
ISSUED AT 1115 AM EST SAT FEB 14 2015
THE CORE OF THE WINTER SEASONS COLDEST AIR WILL CONTINUE TO MOVE IN
THROUGH THE DAY TODAY INTO SUNDAY. TEMPERATURES WILL CONTINUE TO
TUMBLE.
THEREFORE...ICE HAS NOT BUDGED AND CONDITIONS ARE STABLE. THERE IS
IS LOW RISK THAT ANY MOVEMENT WILL OCCUR THROUGH NEXT WEEK AS THE
WARMEST HIGH TEMPERATURES IN THE NEXT SEVERAL DAYS ONLY REACH INTO
THE 20S. DAILY AVERAGE TEMPERATURES IN THE SINGLE DIGITS AND TEENS
WILL AID IN ADDITIONAL ICE FORMATION OR EXPANSION.
LIQUID CONTRIBUTION WILL REMAIN RATHER LOW DAY TO DAY. ADDITIONAL
ROUNDS OF SNOW ARE POSSIBLE THIS WEEK...ESPECIALLY ALONG THE LAKE
SHORE...BUT NOT MUCH MELTING WILL BE TAKING PLACE THROUGH THE PERIOD.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MIZ037-043-
050-056-064-071.
WIND CHILL WARNING UNTIL NOON EST SUNDAY FOR MIZ038>040-044>046-
051-052-057>059-065>067-072>074.
LM...NONE.
&&
$$
UPDATE...NJJ
SYNOPSIS...MEADE
SHORT TERM...MEADE
LONG TERM...LAURENS
AVIATION...WDM
HYDROLOGY...JAM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
646 PM EST SAT FEB 14 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 330 PM EST SAT FEB 14 2015
DANGEROUS COLD IS IN STORE TONIGHT AND SUNDAY MORNING. WIND CHILLS
OF 20 TO 35 BELOW WILL RESULT IN FROSTBITE TIMES OF 15 MINUTES OR
LESS.
STRONG WINDS AND BLOWING SNOW WILL SUBSIDE THIS EVENING. HEAVY SNOW
SHOWERS NEAR LAKE MICHIGAN WILL END BY MIDNIGHT. WIND CHILLS WILL
RECOVER SUNDAY AFTERNOON WITH LIGHT WINDS AND BRIGHT SUNSHINE BUT
HIGH TEMPERATURES WILL BE ONLY IN THE SINGLE DIGITS.
TEMPERATURES WILL CONTINUE TO AVERAGE WELL BELOW FOR THE NEXT WEEK
OR MORE. ADDITIONAL PERIODS OF SNOW ARE LIKELY... HEAVY AT TIMES
NEAR LAKE MICHIGAN.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 330 PM EST SAT FEB 14 2015
ATTENTION SHIFTS FROM SNOW/BLOWING SNOW AND HIGH WINDS TO EXTREME
COLD TONIGHT. THE ONGOING HEADLINES WILL REMAIN IN EFFECT FOR A FEW
MORE HOURS TO COVER THE PERIODIC WHITEOUT/GROUND BLIZZARD SITUATION
THEN BECOME WIND CHILL HEADLINES.
WIND GUSTS ARE PEAKING NOW THROUGH ABOUT 5 PM BUT ARE EXPECTED TO
SHUT DOWN PRETTY QUICK THIS EVENING AS THE BOUNDARY LAYER DECOUPLES
SHORTLY AFTER 7 PM. HOWEVER SUSTAINED WINDS DO STAY UP MUCH OF THE
NIGHT WITH SPEEDS OF 10 TO 20 MPH. GUIDANCE HAS BEEN CONSISTENT
SHOWING AIR TEMPS FALLING TO 5 TO 15 BELOW WHICH SUPPORTS MIN WIND
CHILLS REACHING 25 BELOW OR LOWER OVER MUCH OF THE AREA.
INLAND CLEARING/LAND BREEZE FORMATION THIS EVENING WILL ASSIST IN
SENDING LAKESHORE SNOWS OFFSHORE. LATEST HRRR HAS THE LAKE EFFECT
SNOW BANDS SHIFTING OFFSHORE OF MKG AROUND 7 PM...HOLLAND AROUND 8
PM... SOUTH HAVEN AROUND 10 PM... AND LUDINGTON AROUND MIDNIGHT.
SURFACE RIDGING BUILDS IN QUICKLY ON SUNDAY CAUSING WINDS TO LIGHTEN
UP CONSIDERABLY. THUS WIND CHILLS RECOVER SUBSTANTIALLY IN THE
AFTERNOON UNDER BRIGHT SKIES IN FRIGID ARCTIC AIR MASS.
HI RES MODELS BEYOND 24 HOURS INDICATE MESOLOW CIRCULATION WILL
DEVELOP OVER SRN OR CNTRL LAKE MICHIGAN WITHIN MID LAKE CONVERGENCE
BAND. THIS SEEMS REASONABLE GIVEN VERY COLD/CLEAR SYNOPTIC PATTERN
AND STRONG LAND BREEZE CIRCULATIONS ON ALL SIDES OF LK MI. THIS
FEATURE SHOULD EVENTUALLY COME ONSHORE NORTH OF HOLLAND LATE SUNDAY
NIGHT OR MONDAY MORNING AS SYNOPTIC FLOW TURNS SOUTHWESTERLY.
MID LAKE MESO FEATURES CAN PRODUCE EXCESSIVE SNOW RATES... SO THIS
WILL NEED TO BE CLOSELY WATCHED. ALSO DEEPER MOISTURE ARRIVES ABOUT
THE SAME THIS FEATURE COMES ONSHORE AND THE DGZ RETURNS BACK INTO
THE CLOUD LAYER DUE TO WARMING. ADVISORY/WARNING MAY BE NEEDED
MON/MON NGT FOR WEST CENTRAL LWR MI INCLUDING MKG/LDM AREAS.
POSSIBLY BIV/GRR AS WELL DEPENDING ON MEAN LOW LEVEL WIND DIRECTION.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 330 PM EST SAT FEB 14 2015
THE LONG RANGE FORECAST PERIOD CONTINUES TO LOOK VERY COLD AND
SNOWY. ANOTHER SURGE OF ARCTIC AIR WILL BEGIN TO ARRIVE LATE TUESDAY
THROUGH TUESDAY NIGHT BEHIND THE ARCTIC COLD FRONT. MAX TEMPS
WEDNESDAY THROUGH FRIDAY WILL STRUGGLE TO REACH THE UPPER SINGLE
DIGITS TO LOWER TEENS.
THE ARCTIC FRONT WILL BRING POTENTIAL FOR A ROUND OF SNOW SHOWERS
TUESDAY WITH LAKE EFFECT SNOW SHOWERS ANTICIPATED MID TO LATE WEEK.
SIGNIFICANT HEAVY LAKE EFFECT SNOW EVENTS ARE NOT ANTICIPATED BUT
SEVERAL INCHES OF VERY DRY FLUFFY SNOW ARE POSSIBLE THROUGH MID TO
LATE WEEK.
WIND CHILL VALUES WILL BE QUITE COLD AS WELL MID TO LATE WEEK. WIND
CHILL READINGS WEDNESDAY THROUGH FRIDAY MORNING COULD BE COLDER THAN
15 DEGREES BELOW ZERO... ESPECIALLY OVER THE INTERIOR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 645 PM EST SAT FEB 14 2015
FOR THE MOST PART THE SNOW PART OF THIS EVENT IS ENDED AT MOST OF
THE TAF SITES...ONLY MKG WILL CONTINUE TO SEE SNOW SHOWERS TILL
AROUND 06Z-08Z. SURFACE WINDS WILL DIMINISH TO NORTH AROUND 10
KNOTS BY 06Z AND REMAIN SO THROUGH SUNDAY AFTERNOON.
ALL OF THE MODELS ARE EMPHATIC ABOUT BRINGING DRY AIR DOWN FROM
THE NORTH CLEARING BETWEEN 03Z AND 05Z. SATELLITE IMAGES GIVE THE
MODEL FORECAST STRONG SUPPORT AS IR LOOPS SHOW THIS ALREADY
HAPPENING. AFTER THAT SKIES REMAIN CLEAR MOST OF THE DAY ON
SUNDAY. THIS HAPPENS DUE TO WINDS THROUGH 10000 FT AGL TURNING
NORTH BY 03Z THEN NORTH NORTHEAST BY 09Z AND REMAINING SO THROUGH
MOST OF SUNDAY AS SURFACE HIGH PRESSURE MOVES INTO THE AREA. ALL
OF THIS WILL ALSO MEANS WILL DIMINISH CONSIDERABLY OVER THE NEXT
FEW HOURS. BY 06Z ALL BUT MKG SHOULD BE CLEAR WITH A NORTH WIND
AROUND 10 KNOTS.
MUSKEGON WILL REMAIN CLOSE TO THE EDGE OF THE ACTIVE SNOW BAND
UNTIL AROUND 06Z AFTER THAT IT SHOULD PUSH OFF SHORE. MY TAF MAY
HAVE THE SNOW LASTING TO LONG THERE...BUT WE WILL MONITOR THAT
OVER THE NEXT FEW HOURS.
&&
.HYDROLOGY...
ISSUED AT 1115 AM EST SAT FEB 14 2015
THE CORE OF THE WINTER SEASONS COLDEST AIR WILL CONTINUE TO MOVE IN
THROUGH THE DAY TODAY INTO SUNDAY. TEMPERATURES WILL CONTINUE TO
TUMBLE.
THEREFORE...ICE HAS NOT BUDGED AND CONDITIONS ARE STABLE. THERE IS
IS LOW RISK THAT ANY MOVEMENT WILL OCCUR THROUGH NEXT WEEK AS THE
WARMEST HIGH TEMPERATURES IN THE NEXT SEVERAL DAYS ONLY REACH INTO
THE 20S. DAILY AVERAGE TEMPERATURES IN THE SINGLE DIGITS AND TEENS
WILL AID IN ADDITIONAL ICE FORMATION OR EXPANSION.
LIQUID CONTRIBUTION WILL REMAIN RATHER LOW DAY TO DAY. ADDITIONAL
ROUNDS OF SNOW ARE POSSIBLE THIS WEEK...ESPECIALLY ALONG THE LAKE
SHORE...BUT NOT MUCH MELTING WILL BE TAKING PLACE THROUGH THE PERIOD.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MIZ037-038-
043-044-050-056-057-064-071.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR MIZ039-
040-045-046-051-052-058-059-065>067-072>074.
LM...NONE.
&&
$$
SYNOPSIS...MEADE
SHORT TERM...MEADE
LONG TERM...LAURENS
AVIATION...WDM
HYDROLOGY...JAM
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1002 PM CST Sat Feb 14 2015
.UPDATE...
Issued at 954 PM CST SAT FEB 14 2015
Have backed off on introducing snow into the fcst. The nearly arid
airmass is too dry to overcome and it will take awhile to top-down
saturate. So will remove any mention of PoPs overnight and only
mention slight chance PoPs for Sunday morning. 00z NAM/GFs, LSX local
WRF, RAP and HRRR generate no measurable precipitation. Since it
would take significant upward vertical motion and rapid saturation to
overcome this very dry airmass this seems like a reasonable
expectation.
But things look like they will get very interesting from mid Sunday
afternoon through evening. Models are generating moisture further
north within a region of increasing layered frontogenesis. There is
also some isentropic ascent being generated at h7 with one or two
vorticity bands coinciding with the frontogenesis. Not enough time to
chew through all of the new data in time to make significant changes
to the forecast and the need to collaborate with adjacent offices.
Also don`t want to paint the mid shift into a corner but suspect they
will be considering adjusting the region of accumulating snow.
&&
.SHORT TERM...(This Evening through Tuesday Afternoon)
Issued at 223 PM CST SAT FEB 14 2015
Models continue to struggle with the clipper system digging through
the Rockies and merging with richer moisture south of the area. The
GFS, NAM and SREF all have trended drier with the system, while the
GEM and the ECMWF have increased their QPF leading to greater snow
amounts. If anything has been consistent with forecast over the last
few days it`s that models have been extremely inconsistent both with
the track of the upper wave as well as placement and amount of QPF.
For all intents and purposes, this just doesn`t look like big storm
for our forecast area. First, the amount of dry air moving into the
region in the wake of the frontal passage will be tough to overcome.
Second, that dry gets reinforced as the surface high shifts to the
Great Lakes are and we maintain an easterly/northeasterly surface
fetch. It seems that the GEM and ECMWF are perhaps too broad in
their QPF fields given the intrusion of dry air, so have minimized
their input into the forecast. Third, the jet structure still looks
off for getting any significant precipitation for our area. It`s not
until further south and east the some jet enhancement comes into
play leading to greater precipitation amounts south and east of the
forecast area. Fourth, there seems to be a lack of any persistent
frontogenetic band until the enhanced jet dynamics come into play and
then even that is to our south. Fifth, the very strong dendritic
zone omega is gone, perhaps shifting a bit south. That was one the
main features that looked to potential overcome the significant
low-level dry air. About the only positive thing working for this
system is the weak ascent associated with it as the wave passes by.
As a result of the negatives with this system, have continued to
trend amounts downward. For most of the forecast area, this equates
to about dusting to perhaps half an inch. Amounts should increase
over the southern to southeastern zones but still be less than an
inch and half.
Precipitation looks to shift away from the forecast area Sunday
night, giving way to temperatures in the single digits and teens for
Monday morning. Temperatures may rebound to near freezing Monday
afternoon but limited mixing and the potential for lingering cloud
cover, inhibiting maximum insolation, should keep temperatures on
the cold side. Cold air looks to be reinforced late in the day
Tuesday with another cold front. This may also bring us another
round of light snow but for now will continue with just a flurry
mention as as upper-level support looks meager at best. Instead,
cyclonically curved flow and very cold air aloft look to be main
driver of any snow.
.LONG TERM...(Tuesday Evening through Saturday)
Issued at 223 PM CST SAT FEB 14 2015
Upper-level pattern to initially be dominated by broad northwest
flow as longwave troughing stretches from eastern Canada down into
the American Southeast. Despite the passage of several shortwave
troughs embedded in northwest flow...high pressure over the Tenn and
Lwr Miss Rvr Vlys will limit any moisture return into our area
through the latter stages of the work week. The end result will be
continued below normal and dry conditions...at least through Friday
anyway. Following this...upper pattern to become more zonal across the
Nation/s midsection as longwave ridging begins to build across the
American West. As this occurs...both the GFS and ECMWF 12Z solutions
suggest a southern stream storm system tracking east-northeast from
the southern Plains by the start of the weekend. For now...the GFS
has the furthest northward track of this storm system...while the
ECMWF is quite a bit further south. If the GFS solution were taken
verbatim...expect rain to begin overspreading the area Friday night
as warm air advection begins interacting with a preexisting warm
front over the Arkansas River Vly. Initial looks at this system
suggest P-type will mainly be in the form of rain /at least
initially/ as both GFS and ECMWF suggest 850 temps above 0C through
at least Saturday. For now...will maintain Slgt Chc pops through
the conclusion of the fcst.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday Evening)
Issued at 505 PM CST SAT FEB 14 2015
VFR conditions expected through the forecast, though could see
reduced conditions toward the end of the period. Increased winds
will veer through Sunday afternoon, with gusts possible up to 20kts
in the overnight period. Have excluded snow from forecast for the
time being. Greatest forcing remains to the southeast, with weak
indications present to the west near the terminal sites. However, the
best chance of any degradation in visibilities and ceilings
associated with this winter system will occur after 21Z and into the
next forecast period.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...MJ
SHORT TERM...CDB
LONG TERM...32
AVIATION...Welsh
AREA FORECAST DISCUSSION
NWS BILLINGS MT
220 PM MST FRI FEB 13 2015
.SHORT TERM...VALID FOR SAT AND SUN...
...AFTER A VERY PLEASANT AND WARM DAY TODAY...THE WEATHER WILL GET
MORE INTERESTING BY THE END OF THE HOLIDAY WEEKEND...
DAYTIME HIGH TEMPERATURES THIS AFTERNOON ARE APPROACHING NEAR
RECORD VALUES DUE TO STRONG MIXING IN THE LOWER PORTIONS OF THE
ATMOSPHERE. 1 PM TEMPERATURES ACROSS THE REGION WERE GENERALLY IN THE
UPPER 50S AND LOWER 60S AND ON THE RISE DUE TO FAIRLY PERSISTENT
SURFACE WINDS.
BY TONIGHT...MODELS ARE IN GOOD AGREEMENT IN BRINGING A BACK DOOR
COLD FRONT WITH THE AIR BEHIND IT ORIGINATING FROM SOUTHERN
SASKATCHEWAN AND MANITOBA. THERE IS NOT ANY DOUBT IT WILL GET
COOLER IN THE OUR FAR EASTERN ZONES...BUT THERE IS UNCERTAINTY IN HOW
FAR WEST THE COLD AIR WILL ACTUALLY GET. THERE IS A CHANCE SOME
LOCATIONS OUT EAST...BAKER...EKALAKA...COULD SEE HIGHS HOVERING
AROUND 30 DEGREES TOMORROW...WHILE OTHER LOCATIONS SUCH AS
BILLINGS SEE HIGHS WELL INTO THE 50S. WINDS WILL SHIFT EASTERLY
WITH THE ONSET OF THIS BAROCLINIC ZONE...AND BRING SOME CLOUD
COVER WITH IT. HRRR BUFKIT SOUNDING ANALYSIS SUGGESTS THE EASTERLY
FLOW WILL BRING DIMINISHED VISIBILITIES TO KMLS AND KBHK BY
SATURDAY MORNING. HOWEVER...THE COLDEST AIR WILL REMAIN WELL TO
THE NORTH AND EAST OF THE BILLINGS CWA.
FOR SATURDAY NIGHT INTO SUNDAY...THINGS GET A LITTLE MORE
INTERESTING AS THE AFOREMENTIONED LINGERING FRONT INTERACTS WITH
AN UPPER LEVEL SHORTWAVE MOVING IN FROM THE NORTHWEST. THE MAIN
IMPACT WILL NOW TURN TO SNOW ACCUMULATIONS IN THE BEARTOOTH
FOOTHILLS. BUFKIT SOUNDING ANALYSIS HINTS AT A BRIEF PERIOD OF
UPSLOPE FLOW ACCOMPANIED WITH A FAIRLY UNSTABLE AIR MASS BY
TOMORROW AFTERNOON...WHICH COULD GENERATE SEVERAL INCHES OF SNOW
FOR AREAS NEAR NYE AND RED LODGE. TAKING A LOOK AT THE CIPS
ANALOGS FOR SIMILAR CASES...IT FURTHER BACKS THE THEORY THAT THE
FOOTHILL LOCATIONS ARE THE PREFERRED AREA FOR POTENTIAL
ACCUMULATING SNOW. EITHER WAY...DECIDED TO HOLD OFF ON ISSUANCE
OF A WINTER WEATHER ADVISORY AT THIS FORECAST PACKAGE...AS AMOUNTS
ARE STILL NOT SOLIDIFIED AT THIS TIME. WOULD GUESS ANYWHERE FROM
3-6 INCHES IS POSSIBLE WHEN ALL IS SAID AND DONE. SINGER
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
EXTENDED PERIOD BEGINS ON MONDAY WITH THE NOSE OF A STRONG UPPER
LEVEL JET DIVING INTO NORTHERN IDAHO. DURING THE DAYS TO
FOLLOW...THIS JET STREAK WILL SLIDE TO THE EAST AND ASSIST THE
PROGRESSION OF A SERIES OF SHORTWAVES THROUGH THE REGION. THERE
REMAINS THE POTENTIAL FOR SOME ACCUMULATING SNOW IN BOTH THE BIG
HORN AND BEARTOOTH RANGES...AS THE ORIENTATION OF THE MAIN UPPER
LEVEL FORCING FAVORS THOSE PARTICULAR AREAS THE MOST.
AFTER A BRIEF COOLDOWN EARLY IN THE WEEK...TEMPERATURES WILL
AGAIN BECOME SOMEWHAT MILD AFTER MONDAY. THE FORECAST REMAINS
UNCERTAIN AFTER THAT...SO LEFT THE REMAINING FORECAST AS IS UNTIL
MODELS COME INTO BETTER AGREEMENT. SINGER
&&
.AVIATION...
SOMEWHAT GUSTY WINDS WILL CONTINUE INTO THIS EVENING AT ALL
TERMINALS. BY TONIGHT...HOWEVER...A COLD FRONT WILL MAKE ITS WAY
FROM THE NORTHEAST INTO FAR EASTERN MONTANA. WINDS WILL SHIFT TO
AN EASTERLY COMPONENT AT KBHK AND KMLS...BRINGING IN LOW LEVEL
CLOUDS DURING THE OVERNIGHT HOURS. THEREFORE...MVFR CONDITIONS MAY
COME INTO PLAY AT THAT TIME. SINGER
&&
.PRELIMINARY POINT TEMP/POPS...
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 035/059 034/046 027/036 018/037 024/043 028/049 031/046
01/E 25/W 54/J 32/J 11/B 11/B 22/W
LVM 039/060 034/047 026/036 018/040 023/048 029/049 032/048
01/N 34/W 53/J 21/B 11/N 11/N 22/W
HDN 030/056 029/046 024/035 013/034 018/041 023/049 026/045
01/E 24/W 44/J 32/J 22/J 11/B 22/W
MLS 025/038 024/043 021/030 009/026 015/036 019/042 024/040
12/S 21/E 23/J 21/B 22/J 11/B 22/J
4BQ 027/043 027/045 023/033 013/028 017/039 020/047 026/043
12/O 21/E 24/J 31/B 22/J 11/B 22/W
BHK 014/024 017/037 020/027 005/021 010/032 017/038 021/037
12/S 31/N 24/J 21/B 22/J 11/E 22/J
SHR 031/056 029/045 023/032 013/031 016/040 020/047 025/043
01/B 33/W 55/J 42/J 22/J 11/B 22/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1250 AM EST FRI FEB 13 2015
.SYNOPSIS...
ARCTIC AIR WILL POUR DOWN FROM CANADA TONIGHT, PRODUCING DANGEROUS
WIND CHILLS OVERNIGHT INTO FRIDAY AFTERNOON. A STORM SYSTEM
SLIDING OUT OF THE GREAT LAKES WILL BRING A FEW INCHES OF SNOW ON
SATURDAY, WITH THE COLDEST AIR SO FAR THIS WINTER TO FOLLOW FOR
SUNDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1030 PM UPDATE...
DRY AIR HAS WEAKENED THE CENTRAL NY SNOW BAND FROM JUST A FEW
HOURS AGO AND OUR FLOW IS FINALLY BECOMING MORE NORTHWEST. THE
RESPONSE IS A SPRAY OF MULTI BAND LAKE SNOWS, EXTENDING ALL THE
WAY INTO THE POCONOS OF NEPA. MAIN UPDATE WAS TO INCREASE SNOW
AMOUNTS IN NEPA INTO THE DUSTING TO 2" RANGE. THE COMBINATION OF
WIND AND SNOW WILL CONTINUE TO PRODUCE LOW VSBYS FOR THE NEXT FEW
HOURS. USED A LAV/HRRR BLEND FOR TEMPS. WE ARE ALREADY AT ZERO
HERE AT THE OFFICE, WITH SUSTAINED WINDS OF 20 MPH. WIND CHILL
WARNING LOOKS GOOD. PREVIOUS AFD IS BELOW.
550 PM UPDATE...
TEMP FORECAST ON TRACK WITH SINGLE NUMBERS ALREADY IN OUR FAR
WEST. LATEST HRRR SEEMS TO HAVE A GREAT HANDLE ON FALLING TEMPS
THIS EVENING, AND OUR CURRENT FORECAST MATCHES THIS VERY WELL.
I DID TWEAK SNOW AMOUNTS AND POPS FOR THE NEXT FEW HOURS AS THE
BAND OVER OSWEGO COUNTY HAS NOT MOVED AS FAR SOUTH AS ANTICIPATED.
OVERALL A QUICK COATING TO AN INCH IS POSSIBLE OVER MUCH OF THE
AREA THROUGH THIS EVENING AS COLDER AIR CONTINUES TO POUR INTO THE
AREA, WITH ON AND OFF SNOW SQUALLS. WHILE AMOUNTS ARE NOT HIGH,
SNOWFALL RATES AND INCREASING WIND WILL CREATE LOW VSBYS FROM TIME
TO TIME. LOCALLY HIGHER AMOUNTS OF 2" TO 4" POSSIBLE ALONG THE
SHORELINE OF ONEIDA LAKE IN PLACES LIKE SYLVAN BEACH, AND JEWELL,
BUT THE HIGHER TOTALS WILL BE MORE IN OSWEGO COUNTY ITSELF.
PREVIOUS AFD IS BELOW.
115 PM UPDATE... POWERFUL CAA WILL INCREASE THROUGH THE
EVENING HOURS, WITH SURFACE TEMPERATURES EXPECTED TO FALL 10 TO 15
DEGREES IN JUST A MATTER OF A FEW HOURS. 925 MB TEMPS WILL FALL
TO -21C AT BGM BY 6Z AND TO -24C BY 12Z.
STRONG GRADIENT WILL KEEP WINDS BETWEEN 12 AND 18 MPH OVERNIGHT,
WHILE GUSTS CONTINUE AROUND 25 MPH.
THE COMBINATION OF WIND AND WELL BELOW TEMPERATURES WILL PRODUCE
RARE WIND CHILL WARNING CRITERIA APPARENT TEMPERATURES...MAINLY
BETWEEN -25F AND -30F. ADVISORY CRITERIA APPARENT TEMPERATURES
SHOULD HOLD INTO FRIDAY AFTERNOON.
1055 AM UPDATE...
WEAK CAA HAS BEGUN THROUGH THE FA. TEMPERATURES WILL HOLD STEADY
OR SLIGHTLY FALL THROUGH THE NEXT 3 TO 5 HOURS. FAR MORE POWERFUL
CAA WILL COMMENCE LATER THIS AFTERNOON AND ACCELERATE AFTER
SUNSET.
MADE MINOR ADJUSTMENTS TO TEMPERATURE TRENDS AND ALTERED THE
GRIDDED POPS/WX BASED ON LATEST NAM12 PROGS. OTHERWISE THE
FORECAST IS IN EXCELLENT SHAPE.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
200 PM UPDATE...
FRIGID APPARENT TEMPERATURES REMAIN IN PLACE THROUGH FRIDAY
AFTERNOON. LIGHT LAKE EFFECT SNOW SHOWERS TO THE NORTH WILL TAPER
OFF AS WINDS SHIFT AND DIRECTIONAL SHEAR INCREASES.
ON SATURDAY, A POWERFUL CYCLONE WILL DROP OUT OF THE GREAT LAKES.
GIVEN THE AMOUNT OF COLD AIR, IT SHOULD COME AS NO SURPRISE THAT
THE SNOW GROWTH AREA IS MAXIMIZED. HOWEVER MOISTURE IS LIMITED, SO
DESPITE THE STRENGTH OF THE STORM, WE ARE FORECASTING A BORDERLINE
ADVISORY/NO-ADVISORY EVENT, WITH 3 TO 4 INCHES OF SNOW
ACCUMULATION OVER AN 18 HOUR PERIOD.
A STAGGERING AMOUNT OF ARCTIC AIR POURS DOWN BEHIND THE CYCLONE.
AT THE SAME TIME, THE CYCLONE EXPLODES ALONG THE ATLANTIC COAST
WHILE THE DOME OF HIGH PRESSURE SLIDES DOWN FROM THE UPPER
MIDWEST. AS A RESULT, A STEEP PRESSURE GRADIENT WILL DEVELOP. THE
COMBINATION OF FRIGID TEMPERATURES SATURDAY NIGHT INTO SUNDAY
LOOKS QUITE DANGEROUS. APPARENT TEMPERATURES BELOW -30F ARE
ANTICIPATED.
925MB TEMPS AT BGM ARE AROUND -23C ON SUNDAY, SO MOST AREAS WILL
SEE MAX TEMPERATURES AROUND ZERO DEGREES. THE HILLTOPS AND THE
NORTHERN FA WILL BE EVEN COLDER.
350 AM EST UPDATE...
FRIDAY WILL FEEL MISERABLY COLD AS WELL AS 850MB TEMPS WILL ONLY
MODERATE BY A COUPLE OF DEGREES. HIGH PRESSURE WILL BUILD OVER THE
REGION ON FRI DURING THE DAY WHICH WILL PUT AN END TO LAKE EFFECT
SHOWERS OVR NY. TEMPS FRIDAY AFTERNOON ARE EXPECTED TO RISE
SLIGHTLY ABOVE ZERO. TEMPS LATE FRI NIGHT/SAT MORNING ARE EXPECTED
TO BE VERY ALSO. MAY NEED TO ISSUE AN ADDITIONAL ADVISORY FOR THIS
TIME FRAME... BUT WILL HOLD OFF FOR NOW.
THE NEXT STORM SYSTEM WILL START TO IMPACT THE CWA SATURDAY
MORNING. STRONG WAA WILL TAKE PLACE AHEAD OF THE SYSTEM RESULTING
IN TEMPS RISING INTO THE LOW MID 20S. THIS SYSTEM MAY BRING
WIDESPREAD SNOW TO THE CWA AND POSSIBLY ADVISORY SNOWFALL AMOUNTS.
WILL KEEP CLOSE EYE ON EVOLUTION OF THIS STORM. THE COLD FRONT
ATTENDANT WITH THIS SYSTEM WILL SURGE THROUGH THE CWA ON SUNDAY.
THE AIRMASS BEHIND THIS SYSTEM WILL BE EVEN COLDER THAN THE
AIRMASS EXPECTED TO MOVE THROUGH LATE TONIGHT. DANGEROUS WIND
CHILL VALUES MAY BE LIKELY AGAIN LATE SAT NIGHT. WIND CHILL VALUES
OF NEGATIVE 30 MAY BE POSSIBLE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIPRES BLDS IN ON MON BRINGING AN END TO ANY LEFTOVER LE IN CNTRL
NY. RDGG REMAINS IN CNTRL THRU TUE WITH A SLOW MODERATION IN TEMPS
UNDER GNRLY CLR SKIES...ALTHOUGH BLO ZERO TEMPS STILL VERY PSBL
OVERNIGHT.
NEXT SYSTEM APRCHS FOR TUE AND WED WITH THE GFS AND EURO IN
FAIR AGREEMENT. ESSENTIALLY A SRN STREAM WV GRABS GULF MOISTURE
AND PHASES WITH A SHRT WV DROPPING SEWRD IN THE NRN STREAM TO DVLP
A SIGNIFICANT SFC LOW OVER THE SE US LATE TUE AND EARLY WED.
SYSTEM THEN RIDES THE SW FLOW TO A PSN NEAR JERSEY CST LTR WED.
THIS BRINGS THE PSBLTY OF COASTAL RAIN BUT A MORE SIGNIFICANT SNOW
INLAND AND OVER THE BGM FCST AREA LATE TUE INTO WED. MODEL DFRNCS
INCLUDE THE USUAL SPEED ISSUES...AND THAT THE EURO SHOWS A WEAKER AND
MORE SHEARED SFC LOW WHILE THE 12Z GFS SHOWS A MORE CONSOLIDATED
LOW AND A STRONGER INV TROF BACK OVER THE FCST AREA. IN ANY
EVENT...PLENTY OF TIME AND PLENTY TO WATCH FOR FOR THE NEXT STORM
IN THE AREA.
FLWD HPC GUID FOR TEMPS WHICH MATCHED WELL WITH THE PRVS FCST AND
SURROUNDING OFFICES. FOR SOME REASON...HPC HAS BEEN DOWNPLAYING
THE PTNL FOR LE IN THE WAKE OF THE WEEKEND SYSTEM SO HAVE BUMPED
UP POPS FOR THAT PSBLTY. FLWD HPC MORE CLOSELY FOR THE APRCHG SYSTEM
AT THE END OF THE PD.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
06Z FRI UPDATE... PERSISTENT MULTI-BAND LES WILL CONTINUE TO BRING
OCNL IFR RESTRICTIONS AT KSYR/KITH/KBGM THROUGH AT LEAST 12-15Z.
RESTRICTIVE CONDS AT KELM/KAVP SHOULD BE TEMPORARY...ENDING BY
ARND 08Z...WHILE KRME REMAINS VFR.
DURG THE LATE MRNG/EARLY AFTN PD (15-21Z)...OTHER THAN RESIDUAL
MVFR RESTRICTIONS AT KSYR...VFR SHOULD PREVAIL AREA-WIDE.
LATE IN THE DAY (21Z-00Z SAT)...A RELATIVELY BRIEF PD OF IFR VSBY`S
IS EXPECTED AT KSYR/KRME...AS A LES BAND LIFTS BACK THROUGH THE
RGN. OTHWS...VFR SHOULD CONTINUE THROUGH THE END OF THE VALID TAF
PD (06Z SAT).
.OUTLOOK...
SAT...RESTRICTIONS FROM -SHSN AND POSSIBLE SNOW SQUALLS.
SUN...RESTRICTIONS POSSIBLE FROM -SHSN...MAINLY CNY.
MON...MAINLY VFR.
TUE...COASTAL LOW POSSIBLY PRODUCING -SN AND ASSOCIATED RESTRICTIONS...
ESPECIALLY LATE TUE-TUE NGT.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WIND CHILL WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ038>040-043-044-047-048-072.
NY...WIND CHILL WARNING UNTIL 4 PM EST THIS AFTERNOON FOR NYZ009-
015>018-022>025-036-037-044>046-055>057-062.
&&
$$
SYNOPSIS...DJP
NEAR TERM...DJP/HEDEN
SHORT TERM...DJP
LONG TERM...DGM
AVIATION...MLJ/MDP
AREA FORECAST DISCUSSION
NWS RALEIGH NC
804 PM EST SAT FEB 14 2015
.SYNOPSIS...
A STRONG COLD FRONT SWEEPS ACROSS NORTH CAROLINA THROUGH
THIS EVENING. ARCTIC HIGH PRESSURE THEN BUILDS SOUTHEAST OVER THE
REGION SUNDAY INTO MONDAY. A STORM SYSTEM MOVES INTO THE SOUTHEAST
UNITED STATES BY TUESDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 310 PM SATURDAY...
THE LATEST SURFACE ANALYSIS SHOWED THE ARCTIC COLD FRONT MOVING
TOWARD THE OHIO RIVER...WITH DECENT PRESSURE FALLS ONGOING AROUND
THE DEEPENING SURFACE LOW OVER WESTERN PENNSYLVANIA AND WIND GUSTS
BEHIND THE FRONT PEAKING AT SOME LOWER 40S KNOTS IN PARTS OF CENTRAL
INDIANA AND OHIO. THERE WERE SOME GUSTS AROUND 30KT STARTING TO GET
INTO THE MOUNTAINS OF NORTH CAROLINA AND SOUTHWEST VIRGINIA. TIMING
OF THE SURFACE FRONT AND THE ONSET OF THE GUSTY WINDS MAY RESULT IN
WINDS APPROACHING WIND ADVISORY CRITERIA A LITTLE LATER...AND THE
CURRENT PLAN IS TO START THE WIND ADVISORY IN THE NORTHWEST PIEDMONT
AT 6 PM...KEEPING THE TIMING AS IS FOR THE REST OF CENTRAL NORTH
CAROLINA AND ADDING THE COUNTIES IN THE FAR SOUTHWEST PIEDMONT AS
BUFR SOUNDINGS AND HRRR WRF 10M WIND GUSTS REALLY DO NOT
DISCRIMINATE MUCH IN THE POTENTIAL WIND FOR CENTRAL NORTH CAROLINA.
THE GFS BUFR SOUNDINGS ARE CONCERNING IN TERMS OF WIND POTENTIAL
WITH SOME MIXING SUGGESTING VALUES THAT COULD APPROACH WARNING
CRITERIA REGARDING GUSTS...IN THE MID TO UPPER 40S KNOTS AT THE TOP
OF THE MIXED LAYER. THE HRRR WRF 10M WINDS ARE SIMILAR...BUT THE NAM
BUFR SOUNDINGS SHOW WINDS SOLIDLY REMAINING IN ADVISORY CRITERIA
WHICH IS SIMILAR TO THE RAP. AS NOTED IN PREVIOUS DISCUSSIONS...THE
GREATEST WIND SHOULD BE WITH AND JUST BEHIND THE FRONT THROUGH THE
EVENING AND INTO THE EARLY OVERNIGHT WITH THE STRONG PRESSURE RISES
AND THICKNESS PACKING. BY SUNRISE SUNDAY...WINDS SHOULD STILL REMAIN
GUSTY...BUT THE 925MB WINDS ARE FORECAST BY THE GFS TO FALL FROM
AROUND 50KT THIS EVENING TO 30 TO 40KT BY 12Z SUNDAY...SO THE TIMING
OF THE WIND ADVISORY TO 6 AM SEEMS REASONABLE.
THE OVERNIGHT TEMPERATURE FORECAST IS STILL CHALLENGING...WITH THE
MAV MOS TAKING KGSO NOW ALL THE WAY DOWN TO 7F FOR A LOW...WITH THE
MET MOS AT 17F AND MOST OF THE GUIDANCE NEAR 20F FOR THE REST OF
CENTRAL NORTH CAROLINA. THE BIAS-CORRECTED MOS GUIDANCE MAY HAVE THE
BEST HANDLE ON THE SITUATION...A GOOD COMPROMISE BETWEEN WHAT COULD
BE EXPECTED BASED SOLELY ON 1000-850MB THICKNESSES WHICH WOULD
STRONGLY SUGGEST SINGLE DIGITS...AND THE MAJORITY OF THE GUIDANCE
WHICH IS SEVERAL CATEGORIES HIGHER. PLANNING ON MINIMUM TEMPERATURES
IN THE LOWER TEENS NORTHWEST TO NEAR 20 FAR SOUTH.
GIVEN THE WIND AND THE FORECAST LOWS...WIND CHILL ADVISORY CRITERIA
WILL BE CLOSE IN MANY AREAS NORTH OF U.S. 64. THE ANTICIPATED
FORECAST VALUES OF WIND AND TEMPERATURE WOULD RESULT IN MINIMUM
APPARENT TEMPERATURES LATE TONIGHT JUST BELOW ZERO FROM THE
IMMEDIATE TRIAD TO NEAR HENDERSON...AND ON THE ZERO LINE FROM ABOUT
LEXINGTON TO NEAR OR JUST NORTH OF ROCKY MOUNT. IN COORDINATION WITH
ADJACENT OFFICES AND GIVEN THE GRIDDED FORECAST VALUES OF WIND CHILL
LATE WILL ISSUE A WIND CHILL ADVISORY LATE TONIGHT AND EARLY SUNDAY
MORNING FOR MUCH OF CENTRAL NORTH CAROLINA NORTH OF A LINE FROM
ABOUT KEXX TO KRWI. THIS WILL INCLUDE RANDOLPH...CHATHAM...AND WAKE
COUNTIES TO NASH AND HALIFAX NORTH. THE FORMER THREE COUNTIES COULD
LIKELY BE ON THE MARGINS OF AN ADVISORY BUT SHOULD BE CLOSE ENOUGH
IN SOME PARTS OF THEM TO INCLUDE AT THIS POINT.
EXPECT ENOUGH FORCING AS THE LEFT ENTRANCE REGION OF 140KT 300MB AND
500MB JETS...WITH THE FRONT AND STRONG MID-LEVEL VORTICITY
ADVECTION...TO HAVE ISOLATED TO SCATTERED SHOWERS ALONG THE FRONT
DESPITE PRECIPITABLE WATER VALUES ONLY RISING TO ABOUT NORMAL...OR
JUST BELOW 0.5 INCH. THE HRRR WRF DEPICTS A NARROW BAND OF ISOLATED
TO SCATTERED SHOWERS...WITH THE RELATIVELY GREATER CHANCE IN THE
INTERSTATE 85 CORRIDOR TOWARD KRWI AND KIXA CLOSER TO THE STRONGER
FORCING ALOFT AND LIFT. BUFR SOUNDINGS TOWARD KFAY AND ESPECIALLY
TOWARD KRWI SHOW THE COINCIDENCE OF LOW LEVELS COOLING AND MOISTURE
IN THE -10C OR SLIGHTLY COLDER ZONE THAT SOME OF WHATEVER
PRECIPITATION OCCURS COULD BE MIXED RAIN AND FLURRIES. ANY NON-
LIQUID SHOULD BE QUITE FLEETING WITH THE DRY AIR SURGE MOVING INTO
THE AREA AND THE PACE OF THE FRONTAL PASSAGE.
&&
.SHORT TERM /SUNDAY NIGHT/...
AS OF 310 PM SATURDAY...
THE SURFACE HIGH WILL BUILD IN RAPIDLY WITH THE GRADIENT SLOWLY
RELAXING. 925MB WINDS DIMINISH ALONG WITH 850MB WINDS DIMINISHING TO
20 TO 30KT DURING THE DAY TO 00Z MONDAY. PRECIPITABLE WATER VALUES
AT OR BELOW 0.1 INCH FROM LATE TONIGHT THROUGH SUNDAY WILL RESULT IN
A DRY AIR MASS ALTHOUGH TEMPERATURES SHOULD BE CHILLY. HIGHS SHOULD
ONLY BE FROM THE UPPER 20S FAR NORTH TO POSSIBLY THE MID 30S IN THE
FAR SOUTHWEST PIEDMONT...RESULTING IN MUCH IF NOT ALL OF THE DAY
ACROSS CENTRAL NORTH CAROLINA BELOW FREEZING. SURFACE DEW POINTS
FALL TO CLOSE TO -5F TO -10F...MAKING MINIMUM RELATIVE HUMIDITIES
FROM 15 TO 20 PERCENT. IN COORDINATION WITH THE FOREST SERVICE...
WHILE THESE MINIMUM RELATIVE HUMIDITIES ARE PRETTY LOW...THE COLD
TEMPERATURES TO START...AND THE EXPECTATION THAT AS THE TEMPERATURES
WARM SLOWLY THE WINDS GRADUALLY DIMINISH...RESULT IN MORE OF AN
INCREASED FIRE DANGER CONCERN AS OPPOSED TO RED FLAG. SHOULD THE
TEMPERATURES RISE FASTER THAN EXPECTED AND THE WIND REMAIN GUSTIER
LONGER THAN ANTICIPATED WELL INTO THE 20S KNOTS...A RED FLAG WARNING
COULD BE REQUIRED.
SUNDAY NIGHT...AS THE FLOW ALOFT BACKS...CHANNELED VORTICITY ALOFT
IS FORECAST TO MOVE INTO CENTRAL NORTH CAROLINA ALONG WITH AN
INCREASE IN UPPER-LEVEL MOISTURE. BOTH THE NAM AND GFS BUFR
SOUNDINGS PROVIDE FOR GOOD MOISTURE BY THE LATE NIGHT HOURS OVER
MUCH OF CENTRAL NORTH CAROLINA AT AND ABOVE ABOUT 700MB. THE SUB-
CLOUD LAYER IS VERY DRY AT AND AROUND 850MB...SO WHILE THERE COULD
BE VIRGA WITH EVEN SOME LIMITED LIFT...THE DRY SUB-CLOUD LAYER
SHOULD PRECLUDE ANY EVEN TRACE PRECIPITATION FROM REACHING THE
GROUND. TEMPERATURES SHOULD FALL QUICKLY SUNDAY EVENING BEFORE MORE
CLOUDS START TO MOVE IN UNDER A LIGHT WIND...LOWS IN THE TEENS TO
NEAR 20.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...
INCREASING CONFIDENCE FOR WINTER STORM CONDITIONS LATE MONDAY
THROUGH TUESDAY...
DAYTIME MONDAY WILL SEE INCREASING CLOUDINESS AHEAD OF A LEAD SHORT
WAVE THAT`S PROGGED TO ZIP ACROSS THE STATE BETWEEN 15Z MON AND 03Z
TUE. THEN THE MAIN SYSTEM...IN THE FORM OF A SOUTHERN STREAM DRIVEN
SFC LOW WILL LIFT FROM THE DEEP SOUTH MONDAY EVENING TO SOMEWHERE
ALONG OR JUST OFF THE CAROLINA COAST DURING THE DAY TUESDAY...THEN
LIFT NE AND AWAY TUESDAY NIGHT.
IMPACTS ON MONDAY: MONDAY WILL REMAIN COLD (HIGHS ONLY IN THE LOW-
MID 30S)...AND THAT WILL SET THE STAGE FOR SNOW AS THE P-TYPE...AND
EFFICIENT ACCUMULATION POTENTIAL...WITH ANY PRECIP THAT FALLS LATE
MONDAY INTO THE EARLY MORNING HOURS TUESDAY. A BAND OF LIGHT PRECIP
IS EXPECTED TO MOVE ACROSS CENTRAL NC DURING THE LATE AFTERNOON
MONDAY THROUGH LATE MONDAY EVENING...RESULTING IN PERHAPS AN INCH OR
TWO OF SNOW ACCUMULATION MAINLY ACROSS THE WESTERN PIEDMONT AND
ALONG AND SOUTH OF HWY 64...WITH PERHAPS LIGHTER AMOUNTS ACROS OUR
NE ZONES.
THEN FOR THE MAIN SYSTEM EARLY TUESDAY MORNING THROUGH WEDNESDAY
MORNING...WE STILL HAVE FAIRLY LOW CONFIDENCE GIVEN THE ON-GOING
MODEL DIFFERENCES...ESPECIALLY NOW THAT THE 12Z ECMWF IS EVEN FASTER
AND FARTHER EAST WITH THE SFC LOW...AND MORE IMPORTANTLY MUCH
FARTHER EAST WITH THE DEEPEST MOISTURE. IF THE 12Z ECWMF WERE TO
VERIFY...WE`D BE LOOKING AT A WARNING-CRITERIA SNOW EVENT (3 OR MORE
INCHES) ACROSS MUCH OF OUR CWA...MOSTLY FALLING MONDAY NIGHT INTO
TUESDAY MORNING...WITH PERHAPS SOME FREEZING RAIN MIXING IN ACROSS
OUR SE ZONES...ALL OF WHICH ENDS BY TUESDAY AFTERNOON AS THE LOW
EXITS. THE 12Z GFS...WHICH HAS BEEN BOUNCING AROUND A LOT...HAS
SHIFTED BACK EAST A BIT WITH THE LOW POSITION AND ITS SWATH OF
HEAVIEST QPF VALUES. THE 12Z GFS SUGGESTS THE FOLLOWING:
-THE COLUMN WILL REMAIN COLDEST...THUS ALLOWING FOR AN ALL-SNOW
EVENT...ACROSS OUR TRIAD ZONES...BUT THAT`S WHERE THE LEAST QPF
IS...THUS SUGGESTING SNOW AMOUNTS BARELY REACH WARNING CRITERIA.
-A SWATH OF WARNING-CRITERIA SNOW ALONG THE HWY 64 CORRIDOR...WHICH
MAY MIX WITH OR CHANGE TO FREEZING RAIN...POTENTIALLY ADDING A LAYER
OF ICE ON TOP OF ANY SNOW THAT FALLS...DURING THE DAYLIGHT HOURS
TUESDAY...BEFORE CHANGING BACK TO SNOW TUESDAY NIGHT WITH ANOTHER
LIGHT ACCUMULATION OF SNOW BEFORE ENDING EARLY WED MORNING.
-ACROSS OUR SOUTHERN AND SOUTHEAST-MOST ZONES...A BRIEF PERIOD OF
SNOW (PERHAPS AN INCH OR SO) IN THE PREDAWN HOURS TUESDAY...THEN
CHANGING TO A PERIOD OF FREEZING RAIN DURING THE DAYTIME TUESDAY.
GFS WOULD SUGGEST THAT WARNING CRITERIA ICE ACCUMULATION (A 1/4 INCH
OR MORE) IS POSSIBLE IN THIS AREA...BUT TEMPS BY TUESDAY AFTERNOON
WILL BE CLOSE TO FREEZING..AND GIVEN THE DAYTIME FACTOR...ALL OF
WHICH COULD LIMIT ICE ACCUMS. ALSO...ACROSS THE FAR SOUTHERN PORTION
OF THIS AREA (NEAR THE SC BORDER)...TEMPS MAY WARM ENOUGH TO GO TO
ALL RAIN...WHICH WOULD GREATLY LIMIT THE ICE ACCUMS.
ONE OF THE GREATEST CHALLENGES WITH THIS FORECAST WILL BE PREDICTING
THE JUXTAPOSITION OF THE COLD-ENOUGH-FOR-SNOW AIR WITH THE HEAVY
QPF...THAT COULD RESULT IN A HEAVY SNOW SWEET SPOT SOMEWHERE IN OUR
CWA. RIGHT NOW...IT`S JUST TOO SOON TO SAY IF AND WHERE THAT WILL
HAPPEN. MORE IMPORTANTLY...WE NEED TO PAY CLOSE ATTENTION TO THE
FREEZING RAIN POTENTIAL...AS SOME OF THE GUIDANCE (SUCH AS THE
NAM...WHICH APPEARS TO BE AN OUTLIER AS IT OFTEN IS) SUGGESTS ICE
ACCUMULATION MAY BE THE BIGGER STORY HERE. STAY TUNED!
AFTER THAT STORM EXITS...LOOK FOR QUIET WEATHER FROM WEDNESDAY
THROUGH FRIDAY...ALBEIT REMAINING BITTER COLD WITH TEMPS REMAINING
BELOW FREEZING FOR A PROLONGED PERIOD DURING THE LATTER HALF OF THE
WEEK..AND POSSIBILITY FOR LOW-TEENS OR UPPER-SINGLE-DIGIT LOWS
THURSDAY AND FRIDAY MORNING. THEN THE NEXT PRECIP-MAKER APPEARS TO
ARRIVE ON SATURDAY.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 755 PM SATURDAY...
24 HOUR TAF PERIOD: VFR CONDITIONS ARE EXPECTED TO CONTINUE FOR THE
24 HOUR TAF PERIOD. HOWEVER... GUSTY NORTHWESTERLY ARE EXPECTED
BEHIND A STRONG ARCTIC COLD FRONT EXPECTED TO MOVE ACROSS THE REGION
THIS EVENING. WINDS GUST OF 25 TO 40 KTS ARE EXPECT THIS EVENING
INTO EARLY TUESDAY MORNING OUT OF THE NORTHWEST... LEADING TO
CROSSWIND ISSUES FOR SW TO NE ORIENTED RUNWAYS. IN ADDITION... A
BRIEF SHOWER OR SNOW SHOWERS WILL BE POSSIBLE AS THE LOW LEVEL
FRONTAL ZONE CROSSES THE REGION THIS EVENING. HOWEVER... WE DO NOT
ANTICIPATE ANY SUB-VFR CONDITIONS WITH ANY PRECIP... AS ANY PRECIP
SHOULD BE LIGHT AND FALLING FROM CLOUD BASES OF 5 TO 8 KFT.
GUSTY NORTHWESTERLY WINDS WILL CONTINUE ON SUNDAY. HOWEVER.. WINDS
ARE ONLY EXPECTED TO BE IN THE 10 TO 15 KT SUSTAINED RANGE... WITH
GUSTS OF 25 TO 30 KTS. EXPECT WINDS WILL WEAKEN CONSIDERABLE LATE IN
THE DAY THOUGH... AROUND 21/22Z WITH THE PRESSURE GRADIENT BEGINNING TO
WEAK.
OUTLOOK: WINDS WILL CONTINUE TO DIMINISH SUNDAY NIGHT AND BECOME
LIGHT...AS HIGHER CLOUDS SPREAD INTO CENTRAL NORTH CAROLINA AND
GRADUALLY THICKEN AND LOWER OVER MOST OF THE AREA BY MONDAY MORNING.
A LOW PRESSURE SYSTEM IS EXPECTED TO MOVE INTO THE SOUTHEASTERN
STATES BY TUESDAY... SPREADING WINTRY PRECIP ACROSS NC LATE MONDAY
INTO TUESDAY. AVIATION INTERESTS SHOULD MONITOR THE LATEST FORECASTS
AND CONSIDER THE EFFECTS OF WINTRY PRECIPITATION ALONG WITH SUB-VFR
CONDITIONS. VFR CONDITIONS ARE GENERALLY EXPECTED TO RETURN BY
WEDNESDAY AND CONTINUE THROUGH THURSDAY.
&&
.FIRE WEATHER...
AS OF 310 PM SUNDAY...
AS NOTED IN THE SHORT-TERM DISCUSSION ABOVE...FOLLOWING THE FIRE
WEATHER CONCERNS OF TODAY...SURFACE DEW POINTS FALL TO CLOSE TO -5F
TO -10F SUNDAY...MAKING MINIMUM RELATIVE HUMIDITIES FROM 15 TO 20
PERCENT. IN COORDINATION WITH THE FOREST SERVICE...WHILE THESE
MINIMUM RELATIVE HUMIDITIES ARE PRETTY LOW...THE COLD TEMPERATURES
TO START...AND THE EXPECTATION THAT AS THE TEMPERATURES WARM SLOWLY
THE WINDS GRADUALLY DIMINISH...RESULT IN MORE OF AN INCREASED FIRE
DANGER CONCERN AS OPPOSED TO RED FLAG. SHOULD THE TEMPERATURES RISE
FASTER THAN EXPECTED AND THE WIND REMAIN GUSTIER LONGER THAN
ANTICIPATED WELL INTO THE 20S KNOTS...A RED FLAG WARNING COULD BE
REQUIRED.
&&
.CLIMATE...
THE FOLLOWING ARE TEMPERATURE RECORDS FOR FEBRUARY 15 AND 16:
RECORD LOWS
GSO RDU FAY
FEBRUARY 15: 6 IN 1943 6 IN 1899 12 IN 1943
FEBRUARY 16: 8 IN 1905 11 IN 1905 17 IN 1991
RECORD LOW MAXIMUMS
GSO RDU FAY
FEBRUARY 15: 28 IN 1943 29 IN 1943 36 IN 1965
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 AM EST SUNDAY FOR NCZ008>011-024>028-
040>043-073>078-083>086-088-089.
WIND ADVISORY UNTIL 6 AM EST SUNDAY FOR NCZ007-021>023-038-039.
WIND CHILL ADVISORY FROM 4 AM TO 9 AM EST SUNDAY FOR
NCZ007>011-021>027-038>041.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...RAH
AVIATION...RAH/DJF
FIRE WEATHER...DJF
CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
609 PM EST SAT FEB 14 2015
.SYNOPSIS...
A STRONG COLD FRONT SWEEPS ACROSS NORTH CAROLINA THROUGH
THIS EVENING. ARCTIC HIGH PRESSURE THEN BUILDS SOUTHEAST OVER THE
REGION SUNDAY INTO MONDAY. A STORM SYSTEM MOVES INTO THE SOUTHEAST
UNITED STATES BY TUESDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 310 PM SATURDAY...
THE LATEST SURFACE ANALYSIS SHOWED THE ARCTIC COLD FRONT MOVING
TOWARD THE OHIO RIVER...WITH DECENT PRESSURE FALLS ONGOING AROUND
THE DEEPENING SURFACE LOW OVER WESTERN PENNSYLVANIA AND WIND GUSTS
BEHIND THE FRONT PEAKING AT SOME LOWER 40S KNOTS IN PARTS OF CENTRAL
INDIANA AND OHIO. THERE WERE SOME GUSTS AROUND 30KT STARTING TO GET
INTO THE MOUNTAINS OF NORTH CAROLINA AND SOUTHWEST VIRGINIA. TIMING
OF THE SURFACE FRONT AND THE ONSET OF THE GUSTY WINDS MAY RESULT IN
WINDS APPROACHING WIND ADVISORY CRITERIA A LITTLE LATER...AND THE
CURRENT PLAN IS TO START THE WIND ADVISORY IN THE NORTHWEST PIEDMONT
AT 6 PM...KEEPING THE TIMING AS IS FOR THE REST OF CENTRAL NORTH
CAROLINA AND ADDING THE COUNTIES IN THE FAR SOUTHWEST PIEDMONT AS
BUFR SOUNDINGS AND HRRR WRF 10M WIND GUSTS REALLY DO NOT
DISCRIMINATE MUCH IN THE POTENTIAL WIND FOR CENTRAL NORTH CAROLINA.
THE GFS BUFR SOUNDINGS ARE CONCERNING IN TERMS OF WIND POTENTIAL
WITH SOME MIXING SUGGESTING VALUES THAT COULD APPROACH WARNING
CRITERIA REGARDING GUSTS...IN THE MID TO UPPER 40S KNOTS AT THE TOP
OF THE MIXED LAYER. THE HRRR WRF 10M WINDS ARE SIMILAR...BUT THE NAM
BUFR SOUNDINGS SHOW WINDS SOLIDLY REMAINING IN ADVISORY CRITERIA
WHICH IS SIMILAR TO THE RAP. AS NOTED IN PREVIOUS DISCUSSIONS...THE
GREATEST WIND SHOULD BE WITH AND JUST BEHIND THE FRONT THROUGH THE
EVENING AND INTO THE EARLY OVERNIGHT WITH THE STRONG PRESSURE RISES
AND THICKNESS PACKING. BY SUNRISE SUNDAY...WINDS SHOULD STILL REMAIN
GUSTY...BUT THE 925MB WINDS ARE FORECAST BY THE GFS TO FALL FROM
AROUND 50KT THIS EVENING TO 30 TO 40KT BY 12Z SUNDAY...SO THE TIMING
OF THE WIND ADVISORY TO 6 AM SEEMS REASONABLE.
THE OVERNIGHT TEMPERATURE FORECAST IS STILL CHALLENGING...WITH THE
MAV MOS TAKING KGSO NOW ALL THE WAY DOWN TO 7F FOR A LOW...WITH THE
MET MOS AT 17F AND MOST OF THE GUIDANCE NEAR 20F FOR THE REST OF
CENTRAL NORTH CAROLINA. THE BIAS-CORRECTED MOS GUIDANCE MAY HAVE THE
BEST HANDLE ON THE SITUATION...A GOOD COMPROMISE BETWEEN WHAT COULD
BE EXPECTED BASED SOLELY ON 1000-850MB THICKNESSES WHICH WOULD
STRONGLY SUGGEST SINGLE DIGITS...AND THE MAJORITY OF THE GUIDANCE
WHICH IS SEVERAL CATEGORIES HIGHER. PLANNING ON MINIMUM TEMPERATURES
IN THE LOWER TEENS NORTHWEST TO NEAR 20 FAR SOUTH.
GIVEN THE WIND AND THE FORECAST LOWS...WIND CHILL ADVISORY CRITERIA
WILL BE CLOSE IN MANY AREAS NORTH OF U.S. 64. THE ANTICIPATED
FORECAST VALUES OF WIND AND TEMPERATURE WOULD RESULT IN MINIMUM
APPARENT TEMPERATURES LATE TONIGHT JUST BELOW ZERO FROM THE
IMMEDIATE TRIAD TO NEAR HENDERSON...AND ON THE ZERO LINE FROM ABOUT
LEXINGTON TO NEAR OR JUST NORTH OF ROCKY MOUNT. IN COORDINATION WITH
ADJACENT OFFICES AND GIVEN THE GRIDDED FORECAST VALUES OF WIND CHILL
LATE WILL ISSUE A WIND CHILL ADVISORY LATE TONIGHT AND EARLY SUNDAY
MORNING FOR MUCH OF CENTRAL NORTH CAROLINA NORTH OF A LINE FROM
ABOUT KEXX TO KRWI. THIS WILL INCLUDE RANDOLPH...CHATHAM...AND WAKE
COUNTIES TO NASH AND HALIFAX NORTH. THE FORMER THREE COUNTIES COULD
LIKELY BE ON THE MARGINS OF AN ADVISORY BUT SHOULD BE CLOSE ENOUGH
IN SOME PARTS OF THEM TO INCLUDE AT THIS POINT.
EXPECT ENOUGH FORCING AS THE LEFT ENTRANCE REGION OF 140KT 300MB AND
500MB JETS...WITH THE FRONT AND STRONG MID-LEVEL VORTICITY
ADVECTION...TO HAVE ISOLATED TO SCATTERED SHOWERS ALONG THE FRONT
DESPITE PRECIPITABLE WATER VALUES ONLY RISING TO ABOUT NORMAL...OR
JUST BELOW 0.5 INCH. THE HRRR WRF DEPICTS A NARROW BAND OF ISOLATED
TO SCATTERED SHOWERS...WITH THE RELATIVELY GREATER CHANCE IN THE
INTERSTATE 85 CORRIDOR TOWARD KRWI AND KIXA CLOSER TO THE STRONGER
FORCING ALOFT AND LIFT. BUFR SOUNDINGS TOWARD KFAY AND ESPECIALLY
TOWARD KRWI SHOW THE COINCIDENCE OF LOW LEVELS COOLING AND MOISTURE
IN THE -10C OR SLIGHTLY COLDER ZONE THAT SOME OF WHATEVER
PRECIPITATION OCCURS COULD BE MIXED RAIN AND FLURRIES. ANY NON-
LIQUID SHOULD BE QUITE FLEETING WITH THE DRY AIR SURGE MOVING INTO
THE AREA AND THE PACE OF THE FRONTAL PASSAGE.
&&
.SHORT TERM /SUNDAY NIGHT/...
AS OF 310 PM SATURDAY...
THE SURFACE HIGH WILL BUILD IN RAPIDLY WITH THE GRADIENT SLOWLY
RELAXING. 925MB WINDS DIMINISH ALONG WITH 850MB WINDS DIMINISHING TO
20 TO 30KT DURING THE DAY TO 00Z MONDAY. PRECIPITABLE WATER VALUES
AT OR BELOW 0.1 INCH FROM LATE TONIGHT THROUGH SUNDAY WILL RESULT IN
A DRY AIR MASS ALTHOUGH TEMPERATURES SHOULD BE CHILLY. HIGHS SHOULD
ONLY BE FROM THE UPPER 20S FAR NORTH TO POSSIBLY THE MID 30S IN THE
FAR SOUTHWEST PIEDMONT...RESULTING IN MUCH IF NOT ALL OF THE DAY
ACROSS CENTRAL NORTH CAROLINA BELOW FREEZING. SURFACE DEW POINTS
FALL TO CLOSE TO -5F TO -10F...MAKING MINIMUM RELATIVE HUMIDITIES
FROM 15 TO 20 PERCENT. IN COORDINATION WITH THE FOREST SERVICE...
WHILE THESE MINIMUM RELATIVE HUMIDITIES ARE PRETTY LOW...THE COLD
TEMPERATURES TO START...AND THE EXPECTATION THAT AS THE TEMPERATURES
WARM SLOWLY THE WINDS GRADUALLY DIMINISH...RESULT IN MORE OF AN
INCREASED FIRE DANGER CONCERN AS OPPOSED TO RED FLAG. SHOULD THE
TEMPERATURES RISE FASTER THAN EXPECTED AND THE WIND REMAIN GUSTIER
LONGER THAN ANTICIPATED WELL INTO THE 20S KNOTS...A RED FLAG WARNING
COULD BE REQUIRED.
SUNDAY NIGHT...AS THE FLOW ALOFT BACKS...CHANNELED VORTICITY ALOFT
IS FORECAST TO MOVE INTO CENTRAL NORTH CAROLINA ALONG WITH AN
INCREASE IN UPPER-LEVEL MOISTURE. BOTH THE NAM AND GFS BUFR
SOUNDINGS PROVIDE FOR GOOD MOISTURE BY THE LATE NIGHT HOURS OVER
MUCH OF CENTRAL NORTH CAROLINA AT AND ABOVE ABOUT 700MB. THE SUB-
CLOUD LAYER IS VERY DRY AT AND AROUND 850MB...SO WHILE THERE COULD
BE VIRGA WITH EVEN SOME LIMITED LIFT...THE DRY SUB-CLOUD LAYER
SHOULD PRECLUDE ANY EVEN TRACE PRECIPITATION FROM REACHING THE
GROUND. TEMPERATURES SHOULD FALL QUICKLY SUNDAY EVENING BEFORE MORE
CLOUDS START TO MOVE IN UNDER A LIGHT WIND...LOWS IN THE TEENS TO
NEAR 20.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...
INCREASING CONFIDENCE FOR WINTER STORM CONDITIONS LATE MONDAY
THROUGH TUESDAY...
DAYTIME MONDAY WILL SEE INCREASING CLOUDINESS AHEAD OF A LEAD SHORT
WAVE THAT`S PROGGED TO ZIP ACROSS THE STATE BETWEEN 15Z MON AND 03Z
TUE. THEN THE MAIN SYSTEM...IN THE FORM OF A SOUTHERN STREAM DRIVEN
SFC LOW WILL LIFT FROM THE DEEP SOUTH MONDAY EVENING TO SOMEWHERE
ALONG OR JUST OFF THE CAROLINA COAST DURING THE DAY TUESDAY...THEN
LIFT NE AND AWAY TUESDAY NIGHT.
IMPACTS ON MONDAY: MONDAY WILL REMAIN COLD (HIGHS ONLY IN THE LOW-
MID 30S)...AND THAT WILL SET THE STAGE FOR SNOW AS THE P-TYPE...AND
EFFICIENT ACCUMULATION POTENTIAL...WITH ANY PRECIP THAT FALLS LATE
MONDAY INTO THE EARLY MORNING HOURS TUESDAY. A BAND OF LIGHT PRECIP
IS EXPECTED TO MOVE ACROSS CENTRAL NC DURING THE LATE AFTERNOON
MONDAY THROUGH LATE MONDAY EVENING...RESULTING IN PERHAPS AN INCH OR
TWO OF SNOW ACCUMULATION MAINLY ACROSS THE WESTERN PIEDMONT AND
ALONG AND SOUTH OF HWY 64...WITH PERHAPS LIGHTER AMOUNTS ACROS OUR
NE ZONES.
THEN FOR THE MAIN SYSTEM EARLY TUESDAY MORNING THROUGH WEDNESDAY
MORNING...WE STILL HAVE FAIRLY LOW CONFIDENCE GIVEN THE ON-GOING
MODEL DIFFERENCES...ESPECIALLY NOW THAT THE 12Z ECMWF IS EVEN FASTER
AND FARTHER EAST WITH THE SFC LOW...AND MORE IMPORTANTLY MUCH
FARTHER EAST WITH THE DEEPEST MOISTURE. IF THE 12Z ECWMF WERE TO
VERIFY...WE`D BE LOOKING AT A WARNING-CRITERIA SNOW EVENT (3 OR MORE
INCHES) ACROSS MUCH OF OUR CWA...MOSTLY FALLING MONDAY NIGHT INTO
TUESDAY MORNING...WITH PERHAPS SOME FREEZING RAIN MIXING IN ACROSS
OUR SE ZONES...ALL OF WHICH ENDS BY TUESDAY AFTERNOON AS THE LOW
EXITS. THE 12Z GFS...WHICH HAS BEEN BOUNCING AROUND A LOT...HAS
SHIFTED BACK EAST A BIT WITH THE LOW POSITION AND ITS SWATH OF
HEAVIEST QPF VALUES. THE 12Z GFS SUGGESTS THE FOLLOWING:
-THE COLUMN WILL REMAIN COLDEST...THUS ALLOWING FOR AN ALL-SNOW
EVENT...ACROSS OUR TRIAD ZONES...BUT THAT`S WHERE THE LEAST QPF
IS...THUS SUGGESTING SNOW AMOUNTS BARELY REACH WARNING CRITERIA.
-A SWATH OF WARNING-CRITERIA SNOW ALONG THE HWY 64 CORRIDOR...WHICH
MAY MIX WITH OR CHANGE TO FREEZING RAIN...POTENTIALLY ADDING A LAYER
OF ICE ON TOP OF ANY SNOW THAT FALLS...DURING THE DAYLIGHT HOURS
TUESDAY...BEFORE CHANGING BACK TO SNOW TUESDAY NIGHT WITH ANOTHER
LIGHT ACCUMULATION OF SNOW BEFORE ENDING EARLY WED MORNING.
-ACROSS OUR SOUTHERN AND SOUTHEAST-MOST ZONES...A BRIEF PERIOD OF
SNOW (PERHAPS AN INCH OR SO) IN THE PREDAWN HOURS TUESDAY...THEN
CHANGING TO A PERIOD OF FREEZING RAIN DURING THE DAYTIME TUESDAY.
GFS WOULD SUGGEST THAT WARNING CRITERIA ICE ACCUMULATION (A 1/4 INCH
OR MORE) IS POSSIBLE IN THIS AREA...BUT TEMPS BY TUESDAY AFTERNOON
WILL BE CLOSE TO FREEZING..AND GIVEN THE DAYTIME FACTOR...ALL OF
WHICH COULD LIMIT ICE ACCUMS. ALSO...ACROSS THE FAR SOUTHERN PORTION
OF THIS AREA (NEAR THE SC BORDER)...TEMPS MAY WARM ENOUGH TO GO TO
ALL RAIN...WHICH WOULD GREATLY LIMIT THE ICE ACCUMS.
ONE OF THE GREATEST CHALLENGES WITH THIS FORECAST WILL BE PREDICTING
THE JUXTAPOSITION OF THE COLD-ENOUGH-FOR-SNOW AIR WITH THE HEAVY
QPF...THAT COULD RESULT IN A HEAVY SNOW SWEET SPOT SOMEWHERE IN OUR
CWA. RIGHT NOW...IT`S JUST TOO SOON TO SAY IF AND WHERE THAT WILL
HAPPEN. MORE IMPORTANTLY...WE NEED TO PAY CLOSE ATTENTION TO THE
FREEZING RAIN POTENTIAL...AS SOME OF THE GUIDANCE (SUCH AS THE
NAM...WHICH APPEARS TO BE AN OUTLIER AS IT OFTEN IS) SUGGESTS ICE
ACCUMULATION MAY BE THE BIGGER STORY HERE. STAY TUNED!
AFTER THAT STORM EXITS...LOOK FOR QUIET WEATHER FROM WEDNESDAY
THROUGH FRIDAY...ALBEIT REMAINING BITTER COLD WITH TEMPS REMAINING
BELOW FREEZING FOR A PROLONGED PERIOD DURING THE LATTER HALF OF THE
WEEK..AND POSSIBILITY FOR LOW-TEENS OR UPPER-SINGLE-DIGIT LOWS
THURSDAY AND FRIDAY MORNING. THEN THE NEXT PRECIP-MAKER APPEARS TO
ARRIVE ON SATURDAY.
&&
.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
AS OF 1240 PM SATURDAY...
FOR THE 18Z VALID TAF PERIOD...PRIMARY AVIATION CONCERN WILL BE THE
WIND. AN ARCTIC FRONT WILL SWEEP THROUGH CENTRAL NORTH CAROLINA VERY
LATE THIS AFTERNOON THROUGH THE EVENING...BRINGING WITH IT A
POSSIBLE PERIOD OF LOW VFR CEILINGS AND A SHOWER OR TWO. AHEAD OF
THE FRONT SOUTHWEST WINDS GUST TO 30KT...THEN BEHIND THE FRONT...
WINDS TURN SHARPLY NORTHWEST AND INCREASE TO GUSTS AT LEAST INTO THE
UPPER 30S KNOTS...WITH A FEW HIGHER GUSTS LIKELY IN SPOTS. WIND
SPEEDS GRADUALLY DIMINISH SUNDAY.
BEYOND THE 18Z VALID TAF PERIOD...WINDS WILL CONTINUE TO DIMINISH
SUNDAY NIGHT AND BECOME LIGHT...AS HIGHER CLOUDS SPREAD INTO CENTRAL
NORTH CAROLINA AND GRADUALLY THICKEN AND LOWER OVER MOST OF THE AREA
BY MONDAY MORNING. A LOW PRESSURE SYSTEM MOVES INTO THE SOUTHEAST
STATES BY TUESDAY...AND THE EVENTUAL TRACK OF THE SYSTEM WILL HAVE
OBVIOUS IMPLICATIONS ON THE CENTRAL NORTH CAROLINA WEATHER. AVIATION
INTERESTS SHOULD MONITOR THE LATEST FORECASTS AND CONSIDER THE
EFFECTS OF WINTRY PRECIPITATION ALONG WITH SUB-VFR CONDITIONS...WITH
AT LEAST LIGHT WINTRY PRECIPITATION POSSIBLE AS EARLY AS THE DAYTIME
ON MONDAY AS THE AIR MASS MOISTENS FROM ABOVE. VFR CONDITIONS RETURN
BY WEDNESDAY AND CONTINUE THROUGH THURSDAY.
&&
.FIRE WEATHER...
AS OF 310 PM SUNDAY...
AS NOTED IN THE SHORT-TERM DISCUSSION ABOVE...FOLLOWING THE FIRE
WEATHER CONCERNS OF TODAY...SURFACE DEW POINTS FALL TO CLOSE TO -5F
TO -10F SUNDAY...MAKING MINIMUM RELATIVE HUMIDITIES FROM 15 TO 20
PERCENT. IN COORDINATION WITH THE FOREST SERVICE...WHILE THESE
MINIMUM RELATIVE HUMIDITIES ARE PRETTY LOW...THE COLD TEMPERATURES
TO START...AND THE EXPECTATION THAT AS THE TEMPERATURES WARM SLOWLY
THE WINDS GRADUALLY DIMINISH...RESULT IN MORE OF AN INCREASED FIRE
DANGER CONCERN AS OPPOSED TO RED FLAG. SHOULD THE TEMPERATURES RISE
FASTER THAN EXPECTED AND THE WIND REMAIN GUSTIER LONGER THAN
ANTICIPATED WELL INTO THE 20S KNOTS...A RED FLAG WARNING COULD BE
REQUIRED.
&&
.CLIMATE...
THE FOLLOWING ARE TEMPERATURE RECORDS FOR FEBRUARY 15 AND 16:
RECORD LOWS
GSO RDU FAY
FEBRUARY 15: 6 IN 1943 6 IN 1899 12 IN 1943
FEBRUARY 16: 8 IN 1905 11 IN 1905 17 IN 1991
RECORD LOW MAXIMUMS
GSO RDU FAY
FEBRUARY 15: 28 IN 1943 29 IN 1943 36 IN 1965
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 AM EST SUNDAY FOR NCZ008>011-024>028-
040>043-073>078-083>086-088-089.
WIND ADVISORY UNTIL 6 AM EST SUNDAY FOR NCZ007-021>023-038-039.
WIND CHILL ADVISORY FROM 4 AM TO 9 AM EST SUNDAY FOR
NCZ007>011-021>027-038>041.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...RAH
AVIATION...DJF
FIRE WEATHER...DJF
CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1251 AM CST FRI FEB 13 2015
.UPDATE...
ISSUED AT 1251 AM CST FRI FEB 13 2015
CLOUDS HAD CLEARED THROUGH JAMESTOWN...AND TEMPERATURES IN SOUTH
CENTRAL NORTH DAKOTA REMAINED FROM 5-10F...WHILE TEMPERATURES IN THE
FAR WEST HAD RISEN TO AROUND 30F WITH LIGHT WESTERLY WINDS. EXPECT
RISING TEMPERATURES IN CENTRAL NORTH DAKOTA EARLY THIS MORNING AS
WARM ADVECTION CONTINUES PUSHING EASTWARD. ADJUSTED MINIMUM
TEMPERATURES ACCORDINGLY.
UPDATE ISSUED AT 924 PM CST THU FEB 12 2015
AT 9 PM CST CLOUDS HAVE CLEARED THROUGH A RUGBY TO STEELE TO
WISHEK LINE THIS EVENING AS WARM ADVECTION ERODES AND TRANSLATES THE
CLOUD DECK. EXPECT THE CLOUDS TO CLEAR JAMESTOWN BY 1 AM CST. SEEM
TO BE ENOUGH MIXING IN THE BOUNDARY LAYER TO HOLD TEMPERATURES UP
TONIGHT IN SPITE OF THE CLEARING. CURRENT FORECAST MINS LOOK OK.
ADJUSTED CLOUDS TO FIT THE TREND.
UPDATE ISSUED AT 627 PM CST THU FEB 12 2015
DECREASED POPS ACROSS THE SOUTHEAST AND DECREASED CLOUD COVER AS
THE CLOUD DECK IS PUSHING SOUTHEAST FASTER THAN ORIGINALLY
FORECAST. OTHERWISE FORECAST REMAINS ON TRACK.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 400 PM CST THU FEB 12 2015
SNOW ENDING THIS EVENING SOUTHEAST AND LIGHT SNOW ON FRIDAY
HIGHLIGHT THE SHORT TERM.
LIGHT SNOW FOCUSED ACROSS THE JAMES RIVER VALLEY AS OF 2130 UTC
WILL CONTINUE TO QUICKLY DIMINISH BY EARLY THIS EVENING BASED UPON
RADAR TRENDS AND THE 19 UTC HRRR SIMULATED REFLECTIVITY. THE 12
AND INCOMING 18 UTC DETERMINISTIC AND ENSEMBLE SUITES ARE IN AGREEMENT
ON A BAND OF LIGHT SNOW DEVELOPING ACROSS NORTHWEST AND CENTRAL
NORTH DAKOTA DURING THE DAY ON FRIDAY IN ASSOCIATION WITH THE
BAROCLINIC ZONE ON THE LEADING EDGE OF THE NEXT ARCTIC HIGH THAT
WILL PROPAGATE INTO THE NORTHERN PLAINS FRIDAY AFTERNOON AND
EVENING. SNOWFALL AMOUNTS OF LESS THAN ONE INCH ARE EXPECTED.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 400 PM CST THU FEB 12 2015
A COLD FRONT IS EXPECTED TO SWING THROUGH THE AREA FRIDAY. SOME
LIGHT SNOW IS POSSIBLE ALONG THE FRONT AS SURFACE LOW PRESSURE
DEVELOPS ACROSS EASTERN MONTANA. COLD CANADIAN AIR WILL THEN
FILTER INTO THE REGION FRIDAY NIGHT INTO SATURDAY. WIND CHILL
HEADLINES MAY BE NEEDED EAST OF THE MISSOURI RIVER SATURDAY.
THE LATEST 12 UTC MODELS CONTINUE THE TREND OF PREVIOUS
RUNS...WITH A SHORTWAVE AND INVERTED TROUGH SLIDING THROUGH
WESTERN AND CENTRAL NORTH DAKOTA LATE SATURDAY AFTERNOON THROUGH
SUNDAY. WIDESPREAD SNOW AMOUNTS BETWEEN ONE AND FOUR INCHES APPEAR
LIKELY BY SUNDAY EVENING. NORTHERN NORTH DAKOTA APPEARS TO BE
FAVORED TO RECEIVE THE HIGHEST SNOWFALL TOTALS WITH THIS EVENT.
SCATTERED SNOW COULD LINGER THROUGH MONDAY AS STRONG COLD AIR
ADVECTION TAKES HOLD.
THE ECMWF CONTINUES ITS DRY AND COLD FORECAST MONDAY NIGHT
THROUGH WEDNESDAY. HOWEVER THE LATEST GFS RUN BRINGS A CLIPPER
THROUGH NORTH DAKOTA WEDNESDAY AND PRODUCES SOME LIGHT SNOW. WIND
CHILL HEADLINES MAY BE NEEDED MONDAY NIGHT AND TUESDAY NIGHT FOR
AREAS EAST OF THE MISSOURI RIVER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1251 AM CST FRI FEB 13 2015
AT MIDNIGHT CST...WEAK HIGH PRESSURE EXTENDED ACROSS THE WESTERN
DAKOTAS AS A TROUGH OF LOW PRESSURE WAS RETREATING THROUGH
MINNESOTA. MVFR CLOUDS AT KJMS ARE EXPECTED TO CLEAR TO VFR AROUND
06Z. OTHERWISE VFR ACROSS THE REGION AT 06Z. THE NEXT COLD FRONT TO
AFFECT THE REGION EXTENDED FROM A LOW IN NORTHERN MANITOBA
SOUTHWESTWARD ACROSS SOUTHERN SASKATCHEWAN. MVFR CIGS IN SOUTHERN
MANITOBA AND SOUTHERN SASKATCHEWAN ARE EXPECTED TO MOVE INTO KMOT
AND KJMS AROUND/AFTER 12Z...AND THEN EXPAND WESTWARD TO KISN AND
KBIS BY AROUND 18Z...AND KDIK BY AROUND 21Z. THE COLD FRONT AND
ASSOCIATED STRONG COLD ADVECTION BRING A CHANCE FOR SNOW ACROSS
WESTERN NORTH DAKOTA FRIDAY AFTERNOON AND EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...AYD
LONG TERM...AJ
AVIATION...JV
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1103 PM EST SAT FEB 14 2015
.SYNOPSIS...
ARCTIC AIR IS BLASTING INTO THE STATE. THE COLDEST AIR OF THE
SEASON WILL BE UPON US SUNDAY INTO EARLY MONDAY ALONG WITH
DANGEROUSLY LOW WIND CHILLS OF 20 TO 35 BELOW ZERO. THE NEXT
CHANCE FOR SNOW WILL BE AROUND MID WEEK AS AN AREA OF LOW PRESSURE
MOVES NORTHEAST FROM THE GULF COAST STATES. THE ABNORMAL COLD WILL
BE HERE FOR QUITE A LONG TIME.
&&
.NEAR TERM /UNTIL 8 AM SUNDAY MORNING/...
10 PM UPDATE...
NO CHANGES TO FLAGS. WHILE THE SNOWFALL IS ALL BUT OVER...THE
BLOWING SNOW WILL CONTINUE THROUGH THE NIGHT. MID SHIFT CAN RE-
EVALUATE AS NECESSARY. BFD ALREADY AT 1F...AND WIND CHILLS ALREADY
SUB-20-BELOW THERE. TIMING ALL REMAINS THE SAME FOR THE WIND AND
WIND CHILL PRODUCTS. TABLE SET WELL. WILL FRESHEN UP THE WORDING
ON THOSE STATEMENTS.
645 PM UPDATE...
SQUALL CONTINUE EASTWARD AND LOOKS JUST AS BAD AS EVER. EARLIER
INDICATIONS FROM HRRR IMPLIED SOME WEAKENING...BUT NOT VERY MUCH
WEAKENING APPEARS TO BE HAPPENEING YET. LOSS OF DAYTIME HEATING -
FUNNY TO TYPE THAT WORD - WILL DOUBTLESSLY SERVE TO WEAKEN IT
SOMEWHAT - BUT NOT BEFORE IT IS ALMOST OUT OF THE CTP CWA. IT
CONTINUES MOVING AT A REGULAR PACE AND HAVE TIMED IT OUT IN LESS
THAN 2 HRS. EXPECT THE NASTY WINDS AND ISOLD/SCT SHSN BEHIND IT TO
DIMINISH A BIT FOR THE NEXT HR OR TWO. BUT THE NWRLY FLOW WILL
BRING ADDTNL SHSN INTO THE NW AND LAURELS ALL NIGHT AND FLURRIES
ELSEWHERE. WIND CHILL IS ALREADY -14 AT BFD/DUJ AND -13 AT JST.
ALL LOOKS TO BE IN LINE...BUT MAY BE ABLE TO DO SOME CHOPPING OF
THE WINT WX ADVY WITH THE NEXT UPDATE - AS SNOW AMOUNTS WILL BE
LIGHTER OVERNIGHT.
PREV...
SENT A QUICK UPDATE TO COVER INCLUDING THE SOUTHERN ZONES IN A
WINTER WEATHER ADVISORY.
MESO ANAL INDICATES THE ARCTIC COLD FRONT AT MID DAY IS ENTERING
FAR NWRN PA. RADAR SHOWS A DEVELOPING LINE OF SNOW SHOWERS AND
SQUALLS ALONG THE SHARP CONVERGENCE ZONE. LOCALLY WE HAVE A
WIDESPREAD AREA OF FAIRLY LIGHT SNOW BEING FORCED BY STRONG WARM
ADVECTION AHEAD OF THE APPROACHING FRONT. HIGHER ELEVATIONS TO OUR
WEST HAVE EXPERIENCED SMALL ACCUMS OF AN INCH OR 2...WHILE JUST
EAST OF THE HIGHER TERRAIN AMOUNTS HAVE BEEN OF THE NUISANCE OR
DUSTING VARIETY.
HIGH RES MODELS CONTINUE TO INDICATE A LINE OF SNOW SQUALLS NOW
ENTERING NW PORTIONS OF THE REGION...PROGRESSING OFF TO THE EAST
THEREAFTER. RAP DEVELOPS SOME IMPRESSIVE INSTABILITY FOR MID
FEBRUARY...WITH STEEPENING LOW-MID LEVEL LAPSE RATES AND EVEN
COOKING UP A COUPLE OF HUNDRED JOULES OF CAPE IN RESPONSE TO
RAPIDLY FALLING HEIGHTS AND TEMPS ALOFT.
CURRENT TIMING HAS THE COLD FRONT/SQUALL LINE MOVING THROUGH
BRADFORD AROUND 20Z/3PM...MOVING EAST TO A LINE FROM JOHNSTOWN
THROUGH CLEARFIELD UP INTO COUDERSPORT AROUND 21Z/4PM...AND INTO
RENOVO-STATE COLLEGE-ALTOONA BY 22Z/5PM. EAST OF THE CENTRAL
MOUNTAINS THE HRRR TRIES TO MAKE THE SQUALL LINE MORE
DISORGANIZED SO TIMING MAY BE MORE NEBULOUS.
I WOULD NOT RULE OUT A LITTLE THUNDER SNOW AS THE FORCING LOOKS
ESPECIALLY ROBUST FOR THE TIME OF YEAR.
TEMPS IN THE 20S TO LOWER 30S AHEAD OF THE FRONT AND THE
POTENTIAL FOR WET/PRE-TREATED ROADS FROM ANY LIGHT SNOW AHEAD OF
THE FRONT...WILL LEAD TO A DANGEROUS...FLASH FREEZE SETUP AS THE
ARCTIC FRONT PLOWS EAST ACROSS THE STATE ACCOMPANIED BY ONE OR TWO
DISTINCT NORTH/SOUTH BANDS OF BLINDING SNOW SQUALLS...SHARPLY
FALLING TEMPS...AND WIND GUSTS OF 35-45 MPH. HAZARDOUS INTERSTATE
TRAVEL CONDITIONS ARE EXPECTED TO DEVELOP FROM WEST TO EAST THIS
AFTERNOON.
A WINTER WX ADVISORY COVERS MUCH OF CENTRAL PA THROUGH 12Z SUNDAY
AS MODEL BLENDED QPF COMBINED WITH SLR/S OF CLOSE TO 20/1 SUPPORT
A GENERAL 2-4 INCH SNOWFALL TODAY AND TONIGHT FROM THE ONE-TWO
PUNCH OF THE ARCTIC FRONT...THEN PERIODS OF SNOW/SNOW SHOWERS
ASSOCIATED WITH THE PASSAGE OF THE SE DIGGING CLOSED UPPER LOW.
THE HIGHER SNOWFALL AMOUNTS WILL BE CONFINED TO MAINLY THE NW
MTNS...WRN POCONOS AND ENDLESS MTNS OF NEPA...AND THE LAUREL
HIGHLANDS IN THE SOUTHWEST.
EVEN THOSE LOCATIONS THAT FALL SHORT OF ADVISORY CRITERIA SNOW
WILL HAVE TO CONTEND WITH AREAS OF BLOWING/DRIFTING SNOW BEHIND
THE COLD FRONT LATE TODAY AND TONIGHT. BUFKIT SOUNDINGS SUPPORT
FREQUENT GUSTS IN THE 35-40KT RANGE IN WAKE OF FRONT ACROSS MUCH
OF THE CENTRAL RIDGE AND VALLEY REGION...LASTING THRU TONIGHT.
EVEN HIGHER GUSTS...OCNLY UP TO BETWEEN 45-50 KTS APPEAR LIKELY
ACROSS THE REGION NEAR AND TO THE SE OF I-81...SO THE HIGH WIND
WATCH TRANSITIONED TO A HIGH WIND WARNING THERE. THE HIGH WIND
WARNING AND WIND ADVISORY RUNS THROUGH NOON SUNDAY.
THE LOW SHOULD BE QUICKLY RE-DEVELOPING OVER EASTERN PA OR OVER
THE COASTAL WATERS BY EVENING...WITH THE LOCAL AREA TRANSITIONING
INTO A POST COLD FRONTAL FLOW PATTERN. WITH THE LOW EXPECTED TO
BE DEEPENING RAPIDLY...STRONG GUSTY WINDS WILL DEVELOP AND
CONTINUE INTO THE OVERNIGHT CAUSING WIND CHILLS TO DIP TO
DANGEROUSLY LOW LEVELS OVER THE ENTIRE FCST AREA. AFTER
COLLABORATION WITH SURROUNDING WFOS WE DECIDED TO ISSUE A WIND
CHILL WARNING FOR THE ENTIRE CWA TONIGHT THROUGH MONDAY MORNING.
ACTUAL AIR TEMPERATURES WILL PLUMMET TONIGHT TO BETWEEN 5 AND 15
DEGREES BELOW ZERO ACROSS THE NORTHWEST MOUNTAINS AND LAUREL
HIGHLANDS...AND SETTLE BETWEEN ZERO AND 5 ABOVE THROUGHOUT THE
LARGER METRO AREAS OF THE LOWER SUSQUEHANNA VALLEY.
&&
.SHORT TERM /8 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
SHALLOW STRATO CU CLOUDS CLOUDS SHOULD BREAK ALONG AND TO THE SE
OF THE I-99/I-80/RT 220 CORRIDOR SUNDAY AS HIGH PRESSURE BUILDS
EAST FROM THE OHIO VALLEY LATE IN THE DAY. SCATTERED FLURRIES WILL
OCCUR SUNDAY AFTERNOON ACROSS THE CENTRAL ZONES...WHILE THE NW
MTNS AND LAURELS COULD SEE LOCALLY UP TO ANOTHER ADDITIONAL
COATING TO ONE INCH FROM SCATTERED SNOW SHOWERS.
HIGH TEMPERATURES WILL STRUGGLE TO REACH 5 BELOW ZERO ACROSS THE
NORTHWEST MOUNTAINS...AND WILL ONLY MAKE IT TO 10 TO 12 DEGREES
ABOVE ZERO ACROSS THE LOWER SUSQUEHANNA VALLEY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
VERY COLD AIR WILL CONTINUE TO IMPACT THE REGION THROUGH AT LEAST
THE NEXT WEEK AS STRONG RIDGE OVER WESTERN U.S. CONTINUES TO
DIRECT POLAR AIR INTO THE EASTERN U.S. VIA PERSISTENT TROUGH.
RECORD LOWS FOR THE DATE EARLY MONDAY APPEAR LIKELY. LOWS EARLY
MONDAY MORNING UNDER CLEAR TO PARTLY CLOUDY SKIES WITH DIMINISHING
WIND WILL EASILY AVERAGE 10-15 BELOW ZERO ACROSS THE NRN AND
WESTERN MTNS...AND 5-10 BELOW ZERO THROUGHOUT MUCH OF THE CENTRAL
RIDGE AND VALLEY REGION. SOME PROTECTED VALLEYS ACROSS THE NORTH
COULD DIP TO NEAR 25 BELOW BETWEEN 09-12Z MONDAY. SURFACE HIGH
WILL PROPAGATE ACROSS CENTRAL PA MONDAY AND MONDAY NIGHT...MOVING
OFFSHORE ON TUESDAY.
STILL AT LEAST SOME POTENTIAL INDICATED FOR SOME PHASING OF
NORTHERN AND SOUTHERN STREAM WAVES OVER THE GULF COAST AND
SOUTHEASTERN U.S. BY LATER TUE INTO WED...BRINGING THE CHANCE OF
SNOW TO THE REGION. HOWEVER...AGAIN TODAY MODEL TRENDS OVER CONTINUE
TO LEND CREDENCE TOWARD A MORE SUPPRESSED/FLATTER SOUTHERN STREAM
SYSTEM WITH THE ARCTIC AIR DOMINATING THE GREAT LAKES REGION AND
NE U.S. AND THE BULK OF ANY STEADIER/STRATIFORM PRECIP STAYING
CONFINED TO THE SE U.S. AND MAYBE THE VIRGINIAS.
YET ANOTHER SURGE OF EXTREMELY COLD AIR RIDES IN ON PERSISTENT
NORTHWEST LATE NEXT WEEK...AS A MASSIVE RIDGE OF SURFACE HIGH
PRESSURE COVERS THE EASTERN HALF OF THE CONUS.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
UPPER LEVEL LOW JUST SOUTH OF IPT WILL CONTINUE TO SPIN
UP A MAJOR WINTER STORM. DID CUT BACK ON THINGS HERE AND
THERE ABOUT AN HOUR AGO. STILL CONCERN THAT MOISTURE WILL
WORK BACK TO THE SW...ALONG WITH BANDS OF SNOW FROM THE
FROM THE NW. DID A FEW MORE ADJUSTMENTS AT 03Z.
THE MAIN CONCERN INTO SUNDAY WILL BE STRONG WINDS AND
BLOWING SNOW...ALONG WITH EXTREME COLD.
CONDITIONS WILL SLOWLY IMPROVE LATE SUNDAY.
OUTLOOK...
MON...VFR/NO SIG WX.
MONDAY NIGHT AND TUE...CHANCE OF SNOW...MAINLY NW AND SE.
WED...CHANCE OF SNOW SHOWERS...MAINLY NW. SOME CHANCE OF
SNOW ACROSS THE SE EARLY.
THU...CHANCE OF SNOW SHOWERS ACROSS THE WEST AND NORTH.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR PAZ004>006-
010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066.
WIND ADVISORY UNTIL NOON EST SUNDAY FOR PAZ012-017>019-024>028-
033>035-037-041-042-045-046-049>053.
WIND CHILL WARNING UNTIL 10 AM EST MONDAY FOR PAZ012-018-019-
025>028-034>037-041-042-045-046-049>053-056>059-063>066.
WIND CHILL WARNING UNTIL 10 AM EST MONDAY FOR PAZ004>006-010-
011-017-024-033.
HIGH WIND WARNING UNTIL NOON EST SUNDAY FOR PAZ036-056>059-
063>066.
&&
$$
SYNOPSIS...DANGELO/LA CORTE
NEAR TERM...DANGELO/LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1005 PM EST SAT FEB 14 2015
.SYNOPSIS...
ARCTIC AIR IS BLASTING INTO THE STATE. THE COLDEST AIR OF THE
SEASON WILL BE UPON US SUNDAY INTO EARLY MONDAY ALONG WITH
DANGEROUSLY LOW WIND CHILLS OF 20 TO 35 BELOW ZERO. THE NEXT
CHANCE FOR SNOW WILL BE AROUND MID WEEK AS AN AREA OF LOW PRESSURE
MOVES NORTHEAST FROM THE GULF COAST STATES. THE ABNORMAL COLD WILL
BE HERE FOR QUITE A LONG TIME.
&&
.NEAR TERM /UNTIL 8 AM SUNDAY MORNING/...
10 PM UPDATE...
NO CHANGES TO FLAGS. WHILE THE SNOWFALL IS ALL BUT OVER...THE
BLOWING SNOW WILL CONTINUE THROUGH THE NIGHT. MID SHIFT CAN RE-
EVALUATE AS NECESSARY. BFD ALREADY AT 1F...AND WIND CHILLS ALREADY
SUB-20-BELOW THERE. TIMING ALL REMAINS THE SAME FOR THE WIND AND
WIND CHILL PRODUCTS. TABLE SET WELL. WILL FRESHEN UP THE WORDING
ON THOSE STATEMENTS.
645 PM UPDATE...
SQUALL CONTINUE EASTWARD AND LOOKS JUST AS BAD AS EVER. EARLIER
INDICATIONS FROM HRRR IMPLIED SOME WEAKENING...BUT NOT VERY MUCH
WEAKENING APPEARS TO BE HAPPENEING YET. LOSS OF DAYTIME HEATING -
FUNNY TO TYPE THAT WORD - WILL DOUBTLESSLY SERVE TO WEAKEN IT
SOMEWHAT - BUT NOT BEFORE IT IS ALMOST OUT OF THE CTP CWA. IT
CONTINUES MOVING AT A REGULAR PACE AND HAVE TIMED IT OUT IN LESS
THAN 2 HRS. EXPECT THE NASTY WINDS AND ISOLD/SCT SHSN BEHIND IT TO
DIMINISH A BIT FOR THE NEXT HR OR TWO. BUT THE NWRLY FLOW WILL
BRING ADDTNL SHSN INTO THE NW AND LAURELS ALL NIGHT AND FLURRIES
ELSEWHERE. WIND CHILL IS ALREADY -14 AT BFD/DUJ AND -13 AT JST.
ALL LOOKS TO BE IN LINE...BUT MAY BE ABLE TO DO SOME CHOPPING OF
THE WINT WX ADVY WITH THE NEXT UPDATE - AS SNOW AMOUNTS WILL BE
LIGHTER OVERNIGHT.
PREV...
SENT A QUICK UPDATE TO COVER INCLUDING THE SOUTHERN ZONES IN A
WINTER WEATHER ADVISORY.
MESO ANAL INDICATES THE ARCTIC COLD FRONT AT MID DAY IS ENTERING
FAR NWRN PA. RADAR SHOWS A DEVELOPING LINE OF SNOW SHOWERS AND
SQUALLS ALONG THE SHARP CONVERGENCE ZONE. LOCALLY WE HAVE A
WIDESPREAD AREA OF FAIRLY LIGHT SNOW BEING FORCED BY STRONG WARM
ADVECTION AHEAD OF THE APPROACHING FRONT. HIGHER ELEVATIONS TO OUR
WEST HAVE EXPERIENCED SMALL ACCUMS OF AN INCH OR 2...WHILE JUST
EAST OF THE HIGHER TERRAIN AMOUNTS HAVE BEEN OF THE NUISANCE OR
DUSTING VARIETY.
HIGH RES MODELS CONTINUE TO INDICATE A LINE OF SNOW SQUALLS NOW
ENTERING NW PORTIONS OF THE REGION...PROGRESSING OFF TO THE EAST
THEREAFTER. RAP DEVELOPS SOME IMPRESSIVE INSTABILITY FOR MID
FEBRUARY...WITH STEEPENING LOW-MID LEVEL LAPSE RATES AND EVEN
COOKING UP A COUPLE OF HUNDRED JOULES OF CAPE IN RESPONSE TO
RAPIDLY FALLING HEIGHTS AND TEMPS ALOFT.
CURRENT TIMING HAS THE COLD FRONT/SQUALL LINE MOVING THROUGH
BRADFORD AROUND 20Z/3PM...MOVING EAST TO A LINE FROM JOHNSTOWN
THROUGH CLEARFIELD UP INTO COUDERSPORT AROUND 21Z/4PM...AND INTO
RENOVO-STATE COLLEGE-ALTOONA BY 22Z/5PM. EAST OF THE CENTRAL
MOUNTAINS THE HRRR TRIES TO MAKE THE SQUALL LINE MORE
DISORGANIZED SO TIMING MAY BE MORE NEBULOUS.
I WOULD NOT RULE OUT A LITTLE THUNDER SNOW AS THE FORCING LOOKS
ESPECIALLY ROBUST FOR THE TIME OF YEAR.
TEMPS IN THE 20S TO LOWER 30S AHEAD OF THE FRONT AND THE
POTENTIAL FOR WET/PRE-TREATED ROADS FROM ANY LIGHT SNOW AHEAD OF
THE FRONT...WILL LEAD TO A DANGEROUS...FLASH FREEZE SETUP AS THE
ARCTIC FRONT PLOWS EAST ACROSS THE STATE ACCOMPANIED BY ONE OR TWO
DISTINCT NORTH/SOUTH BANDS OF BLINDING SNOW SQUALLS...SHARPLY
FALLING TEMPS...AND WIND GUSTS OF 35-45 MPH. HAZARDOUS INTERSTATE
TRAVEL CONDITIONS ARE EXPECTED TO DEVELOP FROM WEST TO EAST THIS
AFTERNOON.
A WINTER WX ADVISORY COVERS MUCH OF CENTRAL PA THROUGH 12Z SUNDAY
AS MODEL BLENDED QPF COMBINED WITH SLR/S OF CLOSE TO 20/1 SUPPORT
A GENERAL 2-4 INCH SNOWFALL TODAY AND TONIGHT FROM THE ONE-TWO
PUNCH OF THE ARCTIC FRONT...THEN PERIODS OF SNOW/SNOW SHOWERS
ASSOCIATED WITH THE PASSAGE OF THE SE DIGGING CLOSED UPPER LOW.
THE HIGHER SNOWFALL AMOUNTS WILL BE CONFINED TO MAINLY THE NW
MTNS...WRN POCONOS AND ENDLESS MTNS OF NEPA...AND THE LAUREL
HIGHLANDS IN THE SOUTHWEST.
EVEN THOSE LOCATIONS THAT FALL SHORT OF ADVISORY CRITERIA SNOW
WILL HAVE TO CONTEND WITH AREAS OF BLOWING/DRIFTING SNOW BEHIND
THE COLD FRONT LATE TODAY AND TONIGHT. BUFKIT SOUNDINGS SUPPORT
FREQUENT GUSTS IN THE 35-40KT RANGE IN WAKE OF FRONT ACROSS MUCH
OF THE CENTRAL RIDGE AND VALLEY REGION...LASTING THRU TONIGHT.
EVEN HIGHER GUSTS...OCNLY UP TO BETWEEN 45-50 KTS APPEAR LIKELY
ACROSS THE REGION NEAR AND TO THE SE OF I-81...SO THE HIGH WIND
WATCH TRANSITIONED TO A HIGH WIND WARNING THERE. THE HIGH WIND
WARNING AND WIND ADVISORY RUNS THROUGH NOON SUNDAY.
THE LOW SHOULD BE QUICKLY RE-DEVELOPING OVER EASTERN PA OR OVER
THE COASTAL WATERS BY EVENING...WITH THE LOCAL AREA TRANSITIONING
INTO A POST COLD FRONTAL FLOW PATTERN. WITH THE LOW EXPECTED TO
BE DEEPENING RAPIDLY...STRONG GUSTY WINDS WILL DEVELOP AND
CONTINUE INTO THE OVERNIGHT CAUSING WIND CHILLS TO DIP TO
DANGEROUSLY LOW LEVELS OVER THE ENTIRE FCST AREA. AFTER
COLLABORATION WITH SURROUNDING WFOS WE DECIDED TO ISSUE A WIND
CHILL WARNING FOR THE ENTIRE CWA TONIGHT THROUGH MONDAY MORNING.
ACTUAL AIR TEMPERATURES WILL PLUMMET TONIGHT TO BETWEEN 5 AND 15
DEGREES BELOW ZERO ACROSS THE NORTHWEST MOUNTAINS AND LAUREL
HIGHLANDS...AND SETTLE BETWEEN ZERO AND 5 ABOVE THROUGHOUT THE
LARGER METRO AREAS OF THE LOWER SUSQUEHANNA VALLEY.
&&
.SHORT TERM /8 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
SHALLOW STRATO CU CLOUDS CLOUDS SHOULD BREAK ALONG AND TO THE SE
OF THE I-99/I-80/RT 220 CORRIDOR SUNDAY AS HIGH PRESSURE BUILDS
EAST FROM THE OHIO VALLEY LATE IN THE DAY. SCATTERED FLURRIES WILL
OCCUR SUNDAY AFTERNOON ACROSS THE CENTRAL ZONES...WHILE THE NW
MTNS AND LAURELS COULD SEE LOCALLY UP TO ANOTHER ADDITIONAL
COATING TO ONE INCH FROM SCATTERED SNOW SHOWERS.
HIGH TEMPERATURES WILL STRUGGLE TO REACH 5 BELOW ZERO ACROSS THE
NORTHWEST MOUNTAINS...AND WILL ONLY MAKE IT TO 10 TO 12 DEGREES
ABOVE ZERO ACROSS THE LOWER SUSQUEHANNA VALLEY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
VERY COLD AIR WILL CONTINUE TO IMPACT THE REGION THROUGH AT LEAST
THE NEXT WEEK AS STRONG RIDGE OVER WESTERN U.S. CONTINUES TO
DIRECT POLAR AIR INTO THE EASTERN U.S. VIA PERSISTENT TROUGH.
RECORD LOWS FOR THE DATE EARLY MONDAY APPEAR LIKELY. LOWS EARLY
MONDAY MORNING UNDER CLEAR TO PARTLY CLOUDY SKIES WITH DIMINISHING
WIND WILL EASILY AVERAGE 10-15 BELOW ZERO ACROSS THE NRN AND
WESTERN MTNS...AND 5-10 BELOW ZERO THROUGHOUT MUCH OF THE CENTRAL
RIDGE AND VALLEY REGION. SOME PROTECTED VALLEYS ACROSS THE NORTH
COULD DIP TO NEAR 25 BELOW BETWEEN 09-12Z MONDAY. SURFACE HIGH
WILL PROPAGATE ACROSS CENTRAL PA MONDAY AND MONDAY NIGHT...MOVING
OFFSHORE ON TUESDAY.
STILL AT LEAST SOME POTENTIAL INDICATED FOR SOME PHASING OF
NORTHERN AND SOUTHERN STREAM WAVES OVER THE GULF COAST AND
SOUTHEASTERN U.S. BY LATER TUE INTO WED...BRINGING THE CHANCE OF
SNOW TO THE REGION. HOWEVER...AGAIN TODAY MODEL TRENDS OVER CONTINUE
TO LEND CREDENCE TOWARD A MORE SUPPRESSED/FLATTER SOUTHERN STREAM
SYSTEM WITH THE ARCTIC AIR DOMINATING THE GREAT LAKES REGION AND
NE U.S. AND THE BULK OF ANY STEADIER/STRATIFORM PRECIP STAYING
CONFINED TO THE SE U.S. AND MAYBE THE VIRGINIAS.
YET ANOTHER SURGE OF EXTREMELY COLD AIR RIDES IN ON PERSISTENT
NORTHWEST LATE NEXT WEEK...AS A MASSIVE RIDGE OF SURFACE HIGH
PRESSURE COVERS THE EASTERN HALF OF THE CONUS.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
NOT A LOT OF CHANGE FROM EARLIER. 00Z TAFS SENT.
MOST INTENSE SNOW WENT JUST SE OF IPT.
SOUTHERN END OF THE BAND WEAKEN AS IT MOVED EAST OF BEDFORD.
HOWEVER...MORE MULTIPLE BANDS FORMED ACROSS THE SE...WHERE
IT WAS A LITTLE WARMER.
EARLIER DISCUSSION BELOW.
CURRENT FCST LOOKS GOOD. MINOR ADJUSTMENTS MADE TO THE 21Z TAFS.
EVEN SOME THUNDER WITH THE SNOW SQUALLS.
FROM EARLIER THIS AFT.
THE ARCTIC COLD FRONT IS ENTERING NWRN PA AS OF MID DAY....
A SFC LOW ASSOCIATED WITH THE COLD FRONT TRACK ESE ACROSS THE NRN
MID ATLANTIC STATES THIS AFTERNOON BEFORE RAPIDLY INTENSIFYING
JUST OFFSHORE SRN NEW ENGLAND TONIGHT INTO EARLY SUNDAY.
THE ARCTIC COLD FRONT WILL MOVE THROUGH THE FLYING AREA AND BE
THE FOCUS FOR LOCALLY HEAVY SNOW SQUALLS THIS AFTERNOON AND
EVENING...WITH AN AREA OF PRE-FRONTAL LIGHT SNOW AND MVFR/IFR
CONDITIONS ALREADY IMPACTING THE WRN 1/3 TO 1/2 OF THE AIRSPACE.
OVERALL EXPECT PREVAILING IFR ACROSS THE HIGHER ELEVATION SITES
FROM JST UP THROUGH BFD. CENTRAL TERMINALS WILL SEE PERIODS OF
IFR BUT MVFR WILL MORE LIKELY BE THE PREVAILING FLIGHT CAT.
PREVAILING VFR WITH PERIODS OF MVFR CAN BE EXPECTED AT THE SERN
SITES. USED 1HR TEMPO TO SHOW BEST TIME WINDOW FOR HEAVY SNOW AND
REDUCED CONDITIONS ASSOCIATED WITH EXPECTED SNOW SQUALL
ACTIVITY...WITH A SHARP DROP IN VIS TO 1/2 MILE OR LESS. WIND WILL
BECOME THE MAIN CONCERN LATER TONIGHT INTO EARLY SUNDAY WITH
PEAK GUSTS IN THE 35-45KT RANGE FROM AROUND 300 DEGREES. MVFR/IFR
IN OCNL SHSN WILL LINGER OVER THE WRN TERMINALS INTO SUNDAY WITH
GRADUAL IMPROVEMENT EXPECTED DURING THE DAY. ELSEWHERE LOOK FOR A
RETURN TO LOW VFR WITH CIGS BTWN 3000-5000`.
OUTLOOK...
MON-TUE...VFR/NO SIG WX.
WED-THU...MVFR/IFR SHSN WEST. VFR/MVFR EAST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR PAZ004>006-
010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066.
WIND ADVISORY UNTIL NOON EST SUNDAY FOR PAZ012-017>019-024>028-
033>035-037-041-042-045-046-049>053.
WIND CHILL WARNING UNTIL 10 AM EST MONDAY FOR PAZ012-018-019-
025>028-034>037-041-042-045-046-049>053-056>059-063>066.
WIND CHILL WARNING UNTIL 10 AM EST MONDAY FOR PAZ004>006-010-
011-017-024-033.
HIGH WIND WARNING UNTIL NOON EST SUNDAY FOR PAZ036-056>059-
063>066.
&&
$$
SYNOPSIS...DANGELO/LA CORTE
NEAR TERM...DANGELO/LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
644 PM EST SAT FEB 14 2015
.SYNOPSIS...
AN ARCTIC COLD FRONT WILL SWEEP THROUGH THE COMMONWEALTH THIS
AFTERNOON AND EVENING. THE COLDEST AIR OF THE SEASON WILL BE WITH
US SUNDAY INTO EARLY MONDAY ALONG WITH DANGEROUSLY LOW WIND CHILLS
OF 20 TO 35 BELOW ZERO. THE NEXT CHANCE FOR SNOW WILL BE AROUND
MID WEEK AS AN AREA OF LOW PRESSURE MOVES NORTHEAST FROM THE GULF
COAST STATES.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SENT A QUICK UPDATE TO COVER INCLUDING THE SOUTHERN ZONES IN A
WINTER WEATHER ADVISORY.
MESO ANAL INDICATES THE ARCTIC COLD FRONT AT MID DAY IS ENTERING
FAR NWRN PA. RADAR SHOWS A DEVELOPING LINE OF SNOW SHOWERS AND
SQUALLS ALONG THE SHARP CONVERGENCE ZONE. LOCALLY WE HAVE A
WIDESPREAD AREA OF FAIRLY LIGHT SNOW BEING FORCED BY STRONG WARM
ADVECTION AHEAD OF THE APPROACHING FRONT. HIGHER ELEVATIONS TO OUR
WEST HAVE EXPERIENCED SMALL ACCUMS OF AN INCH OR 2...WHILE JUST
EAST OF THE HIGHER TERRAIN AMOUNTS HAVE BEEN OF THE NUISANCE OR
DUSTING VARIETY.
HIGH RES MODELS CONTINUE TO INDICATE A LINE OF SNOW SQUALLS NOW
ENTERING NW PORTIONS OF THE REGION...PROGRESSING OFF TO THE EAST
THEREAFTER. RAP DEVELOPS SOME IMPRESSIVE INSTABILITY FOR MID
FEBRUARY...WITH STEEPENING LOW-MID LEVEL LAPSE RATES AND EVEN
COOKING UP A COUPLE OF HUNDRED JOULES OF CAPE IN RESPONSE TO
RAPIDLY FALLING HEIGHTS AND TEMPS ALOFT.
CURRENT TIMING HAS THE COLD FRONT/SQUALL LINE MOVING THROUGH
BRADFORD AROUND 20Z/3PM...MOVING EAST TO A LINE FROM JOHNSTOWN
THROUGH CLEARFIELD UP INTO COUDERSPORT AROUND 21Z/4PM...AND INTO
RENOVO-STATE COLLEGE-ALTOONA BY 22Z/5PM. EAST OF THE CENTRAL
MOUNTAINS THE HRRR TRIES TO MAKE THE SQUALL LINE MORE
DISORGANIZED SO TIMING MAY BE MORE NEBULOUS.
I WOULD NOT RULE OUT A LITTLE THUNDER SNOW AS THE FORCING LOOKS
ESPECIALLY ROBUST FOR THE TIME OF YEAR.
TEMPS IN THE 20S TO LOWER 30S AHEAD OF THE FRONT AND THE
POTENTIAL FOR WET/PRE-TREATED ROADS FROM ANY LIGHT SNOW AHEAD OF
THE FRONT...WILL LEAD TO A DANGEROUS...FLASH FREEZE SETUP AS THE
ARCTIC FRONT PLOWS EAST ACROSS THE STATE ACCOMPANIED BY ONE OR TWO
DISTINCT NORTH/SOUTH BANDS OF BLINDING SNOW SQUALLS...SHARPLY
FALLING TEMPS...AND WIND GUSTS OF 35-45 MPH. HAZARDOUS INTERSTATE
TRAVEL CONDITIONS ARE EXPECTED TO DEVELOP FROM WEST TO EAST THIS
AFTERNOON.
A WINTER WX ADVISORY COVERS MUCH OF CENTRAL PA THROUGH 12Z SUNDAY
AS MODEL BLENDED QPF COMBINED WITH SLR/S OF CLOSE TO 20/1 SUPPORT
A GENERAL 2-4 INCH SNOWFALL TODAY AND TONIGHT FROM THE ONE-TWO
PUNCH OF THE ARCTIC FRONT...THEN PERIODS OF SNOW/SNOW SHOWERS
ASSOCIATED WITH THE PASSAGE OF THE SE DIGGING CLOSED UPPER LOW.
THE HIGHER SNOWFALL AMOUNTS WILL BE CONFINED TO MAINLY THE NW
MTNS...WRN POCONOS AND ENDLESS MTNS OF NEPA...AND THE LAUREL
HIGHLANDS IN THE SOUTHWEST.
EVEN THOSE LOCATIONS THAT FALL SHORT OF ADVISORY CRITERIA SNOW
WILL HAVE TO CONTEND WITH AREAS OF BLOWING/DRIFTING SNOW BEHIND
THE COLD FRONT LATE TODAY AND TONIGHT. BUFKIT SOUNDINGS SUPPORT
FREQUENT GUSTS IN THE 35-40KT RANGE IN WAKE OF FRONT ACROSS MUCH
OF THE CENTRAL RIDGE AND VALLEY REGION...LASTING THRU TONIGHT.
EVEN HIGHER GUSTS...OCNLY UP TO BETWEEN 45-50 KTS APPEAR LIKELY
ACROSS THE REGION NEAR AND TO THE SE OF I-81...SO THE HIGH WIND
WATCH TRANSITIONED TO A HIGH WIND WARNING THERE. THE HIGH WIND
WARNING AND WIND ADVISORY RUNS THROUGH NOON SUNDAY.
THE LOW SHOULD BE QUICKLY RE-DEVELOPING OVER EASTERN PA OR OVER
THE COASTAL WATERS BY EVENING...WITH THE LOCAL AREA TRANSITIONING
INTO A POST COLD FRONTAL FLOW PATTERN. WITH THE LOW EXPECTED TO
BE DEEPENING RAPIDLY...STRONG GUSTY WINDS WILL DEVELOP AND
CONTINUE INTO THE OVERNIGHT CAUSING WIND CHILLS TO DIP TO
DANGEROUSLY LOW LEVELS OVER THE ENTIRE FCST AREA. AFTER
COLLABORATION WITH SURROUNDING WFOS WE DECIDED TO ISSUE A WIND
CHILL WARNING FOR THE ENTIRE CWA TONIGHT THROUGH MONDAY MORNING.
ACTUAL AIR TEMPERATURES WILL PLUMMET TONIGHT TO BETWEEN 5 AND 15
DEGREES BELOW ZERO ACROSS THE NORTHWEST MOUNTAINS AND LAUREL
HIGHLANDS...AND SETTLE BETWEEN ZERO AND 5 ABOVE THROUGHOUT THE
LARGER METRO AREAS OF THE LOWER SUSQUEHANNA VALLEY.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
SHALLOW STRATO CU CLOUDS CLOUDS SHOULD BREAK ALONG AND TO THE SE
OF THE I-99/I-80/RT 220 CORRIDOR SUNDAY AS HIGH PRESSURE BUILDS
EAST FROM THE OHIO VALLEY LATE IN THE DAY. SCATTERED FLURRIES WILL
OCCUR SUNDAY AFTERNOON ACROSS THE CENTRAL ZONES...WHILE THE NW
MTNS AND LAURELS COULD SEE LOCALLY UP TO ANOTHER ADDITIONAL
COATING TO ONE INCH FROM SCATTERED SNOW SHOWERS.
HIGH TEMPERATURES WILL STRUGGLE TO REACH 5 BELOW ZERO ACROSS THE
NORTHWEST MOUNTAINS...AND WILL ONLY MAKE IT TO 10 TO 12 DEGREES
ABOVE ZERO ACROSS THE LOWER SUSQUEHANNA VALLEY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
VERY COLD AIR WILL CONTINUE TO IMPACT THE REGION THROUGH AT LEAST
THE NEXT WEEK AS STRONG RIDGE OVER WESTERN U.S. CONTINUES TO
DIRECT POLAR AIR INTO THE EASTERN U.S. VIA PERSISTENT TROUGH.
RECORD LOWS FOR THE DATE EARLY MONDAY APPEAR LIKELY. LOWS EARLY
MONDAY MORNING UNDER CLEAR TO PARTLY CLOUDY SKIES WITH DIMINISHING
WIND WILL EASILY AVERAGE 10-15 BELOW ZERO ACROSS THE NRN AND
WESTERN MTNS...AND 5-10 BELOW ZERO THROUGHOUT MUCH OF THE CENTRAL
RIDGE AND VALLEY REGION. SOME PROTECTED VALLEYS ACROSS THE NORTH
COULD DIP TO NEAR 25 BELOW BETWEEN 09-12Z MONDAY. SURFACE HIGH
WILL PROPAGATE ACROSS CENTRAL PA MONDAY AND MONDAY NIGHT...MOVING
OFFSHORE ON TUESDAY.
STILL AT LEAST SOME POTENTIAL INDICATED FOR SOME PHASING OF
NORTHERN AND SOUTHERN STREAM WAVES OVER THE GULF COAST AND
SOUTHEASTERN U.S. BY LATER TUE INTO WED...BRINGING THE CHANCE OF
SNOW TO THE REGION. HOWEVER...AGAIN TODAY MODEL TRENDS OVER CONTINUE
TO LEND CREDENCE TOWARD A MORE SUPPRESSED/FLATTER SOUTHERN STREAM
SYSTEM WITH THE ARCTIC AIR DOMINATING THE GREAT LAKES REGION AND
NE U.S. AND THE BULK OF ANY STEADIER/STRATIFORM PRECIP STAYING
CONFINED TO THE SE U.S. AND MAYBE THE VIRGINIAS.
YET ANOTHER SURGE OF EXTREMELY COLD AIR RIDES IN ON PERSISTENT
NORTHWEST LATE NEXT WEEK...AS A MASSIVE RIDGE OF SURFACE HIGH
PRESSURE COVERS THE EASTERN HALF OF THE CONUS.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
NOT A LOT OF CHANGE FROM EARLIER. 00Z TAFS SENT.
MOST INTENSE SNOW WENT JUST SE OF IPT.
SOUTHERN END OF THE BAND WEAKEN AS IT MOVED EAST OF BEDFORD.
HOWEVER...MORE MULTIPLE BANDS FORMED ACROSS THE SE...WHERE
IT WAS A LITTLE WARMER.
EARLIER DISCUSSION BELOW.
CURRENT FCST LOOKS GOOD. MINOR ADJUSTMENTS MADE TO THE 21Z TAFS.
EVEN SOME THUNDER WITH THE SNOW SQUALLS.
FROM EARLIER THIS AFT.
THE ARCTIC COLD FRONT IS ENTERING NWRN PA AS OF MID DAY....
A SFC LOW ASSOCIATED WITH THE COLD FRONT TRACK ESE ACROSS THE NRN
MID ATLANTIC STATES THIS AFTERNOON BEFORE RAPIDLY INTENSIFYING
JUST OFFSHORE SRN NEW ENGLAND TONIGHT INTO EARLY SUNDAY.
THE ARCTIC COLD FRONT WILL MOVE THROUGH THE FLYING AREA AND BE
THE FOCUS FOR LOCALLY HEAVY SNOW SQUALLS THIS AFTERNOON AND
EVENING...WITH AN AREA OF PRE-FRONTAL LIGHT SNOW AND MVFR/IFR
CONDITIONS ALREADY IMPACTING THE WRN 1/3 TO 1/2 OF THE AIRSPACE.
OVERALL EXPECT PREVAILING IFR ACROSS THE HIGHER ELEVATION SITES
FROM JST UP THROUGH BFD. CENTRAL TERMINALS WILL SEE PERIODS OF
IFR BUT MVFR WILL MORE LIKELY BE THE PREVAILING FLIGHT CAT.
PREVAILING VFR WITH PERIODS OF MVFR CAN BE EXPECTED AT THE SERN
SITES. USED 1HR TEMPO TO SHOW BEST TIME WINDOW FOR HEAVY SNOW AND
REDUCED CONDITIONS ASSOCIATED WITH EXPECTED SNOW SQUALL
ACTIVITY...WITH A SHARP DROP IN VIS TO 1/2 MILE OR LESS. WIND WILL
BECOME THE MAIN CONCERN LATER TONIGHT INTO EARLY SUNDAY WITH
PEAK GUSTS IN THE 35-45KT RANGE FROM AROUND 300 DEGREES. MVFR/IFR
IN OCNL SHSN WILL LINGER OVER THE WRN TERMINALS INTO SUNDAY WITH
GRADUAL IMPROVEMENT EXPECTED DURING THE DAY. ELSEWHERE LOOK FOR A
RETURN TO LOW VFR WITH CIGS BTWN 3000-5000`.
OUTLOOK...
MON-TUE...VFR/NO SIG WX.
WED-THU...MVFR/IFR SHSN WEST. VFR/MVFR EAST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR PAZ004>006-
010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066.
WIND ADVISORY UNTIL NOON EST SUNDAY FOR PAZ012-017>019-024>028-
033>035-037-041-042-045-046-049>053.
WIND CHILL WARNING FROM MIDNIGHT TONIGHT TO 10 AM EST MONDAY
FOR PAZ012-018-019-025>028-034>037-041-042-045-046-049>053-
056>059-063>066.
WIND CHILL WARNING UNTIL 10 AM EST MONDAY FOR PAZ004>006-010-
011-017-024-033.
HIGH WIND WARNING UNTIL NOON EST SUNDAY FOR PAZ036-056>059-
063>066.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
528 PM EST FRI FEB 13 2015
.SYNOPSIS...
A STRONG ARCTIC FRONT WILL SLICE ACROSS THE COMMONWEALTH FROM THE
LATE SATURDAY MORNING THROUGH SATURDAY AFTERNOON...PRECEDED BY
AREAS OF LIGHT SNOW AND A LINE OF INTENSE SNOW SQUALLS. WIDESPREAD
LIGHT SNOW ACCUMULATIONS ARE EXPECTED FOR MOST...WHILE A FEW TO
SEVERAL INCHES OF WIND BLOWN SNOW ARE POSSIBLE ACROSS THE HIGHER
ELEVATIONS OF THE NORTHERN AND WESTERN MOUNTAINS...AND IN
PARTICULAR THE LAUREL HIGHLANDS.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
MCLEAR SKIES AND LIGHT WINDS TO START THIS EVENING...AS SFC RIDGE
DRIFTS ACROSS CENTRAL PA. HOWEVER...SATL LOOP SHOWS CLOUDS IN
ADVANCE OF APPROACHING CLIPPER ABOUT TO ENTER WESTERN PA AT 22Z.
IDEAL RADIATIONAL COOLING SHOULD RESULT IN MIN TEMPS THIS
EVENING...THEN STEADY OR SLOWLY RISING READINGS AS CLOUDS ARRIVE
BTWN 00Z-05Z FROM WEST TO EAST. CONSALL OUTPUT SUGGEST LOWS WILL
RANGE FROM THE UPPER SINGLE DIGITS TO LTEENS OVER MOST OF THE
AREA. HOWEVER...LATEST RAP OUTPUT SUGGESTS THE COLDER VALLEYS OF
THE NORTH WILL DIP BLW ZERO FOR A TIME THIS EVENING...WITH SOME
SINGLE DIGITS IN THE FROST POCKETS OF THE CENTRAL AND SOUTHERN
COUNTIES.
REGIONAL RADAR LOOP AT 22Z SHOWS LIGHT SNOW ACROSS MICHIGAN IN
REGION OF WAA AHEAD OF CLIPPER. LATEST NR TERM MDL DATA SUGGESTS
THIS LGT SNOW WILL OVERSPREAD THE N MTNS BTWN 03Z-06Z. LACK OF
DEEP MOISTURE WILL LIMIT LGT ACCUMS TO MAINLY THE N MTNS...WHERE
SOUTHERLY FLOW/OROGRAPHIC LIFT WILL PLAY A ROLE. BLEND OF MDL QPF
SUPPORTS SNOW AMTS BY DAWN OF NEAR AN INCH ACROSS THE N MTNS...WITH
LITTLE IF ANY ACCUM SOUTH OF I-80.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
A VIGOROUS UPPER TROUGH AND ASSOCIATED ARCTIC FRONT WILL
DROP SOUTHEAST THROUGH THE REGION DURING THE DAY SATURDAY.
BROAD UPPER DIFFLUENCE AHEAD OF THIS TROUGH AND A BRIEF PERIOD OF
SWRLY FLOW AT THE SURFACE WILL MAINTAIN LIGHT SNOW/SNOW SHOWERS
ACROSS WESTERN AND CENTRAL AREAS THROUGH THE MORNING HOURS.
AN APPROX 75NM WIDE BAND OF STEEP MID-LEVEL LAPSE RATES /OR 7-8C
PER KM/ OCCURS ALONG AND JUST IN ADVANCE OF THE ARCTIC FRONT
SATURDAY. THIS WILL LEAD TO SCATTERED...BLINDING SNOW SQUALLS
GIVEN THE STRONG 40-45 KT WINDS AT 850 MB SURROUNDING THE CFROPA.
BTV SNOW SQUALL PARAMETER AND HI RES MESO MODELS ARE HITTING ON
ALL CYLINDERS WITH THIS SQUALL EVENT...AND IT IS CLEAR THAT THE
ARCTIC AIR WILL HAVE A LOUD ARRIVAL PUNCTUATED BY A LINE OF
INTENSE SNOW SQUALLS WITH HAZARDOUS INTERSTATE TRAVEL CONDITIONS
EXPECTED FROM WEST TO EAST SATURDAY AFTERNOON.
FAVORABLE UPSLOPE LOCATIONS NEAR AND TO THE WEST OF RT 219 SEE A
GENERAL 2-4 INCHES...WITH ANOTHER INCH OR SO POSSIBLE FROM THE
LINE OF SQUALLS LEADING TO A GENERAL 3 TO 5 INCHES AND GARNERING
THE ISSUANCE OF A WINTER WEATHER ADVISORY FOR SOMERSET CAMBRIA AND
CLEARFIELD COUNTIES. FARTHER NORTH...SIMILAR 2-3 INCH AMOUNTS LIKELY
ACROSS THE MTNS NE OF KIPT AS THE CENTER OF THE 700-500 MB LOW
MOVES NEAR OR JUST SOUTH OF THE REGION LATE SAT NIGHT.
WIND CHILL WATCH FOR SAT EVENING THROUGH SUNDAY MORNING FOR THE
ENTIRE CWA REMAINS IN EFFECT. HIGH WIND WATCH FOR THE LOWER SUSQ
RIVER VALLEY ALSO REMAINS IN EFFECT.
HIGHS SATURDAY WILL NOSE INTO THE LOWER 20S LATE IN THE MORNING
ACROSS THE NW MTNS AND LAURELS...AND INTO THE LOWER 30S ACROSS THE
SE ZONES EARLY SATURDAY AFTERNOON - BEFORE THE ARCTIC FRONT SURGES
SE ACROSS THE REGION.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
VERY COLD AIR WILL CONTINUE TO IMPACT THE REGION THROUGH AT LEAST
THE NEXT WEEK AS STRONG RIDGE OVER WESTERN U.S. CONTINUES TO
DIRECT POLAR AIR INTO THE EASTERN U.S. VIA PERSISTENT TROUGH.
NEXT STORM WILL BE EXITING THE REGION SAT NIGHT /AND WILL BE
DEEPENING RAPIDLY AS IT IMPACTS THE NEW ENGLAND COAST/...WITH
SNOW SHOWERS LINGERING MAINLY IN MY HIGHER TERRAIN INTO SUNDAY.
SOME DEFORMATION SNOWFALL IS POSSIBLE OVER EASTERN PORTIONS OF MY
CWA EARLY SUNDAY...AND HAVE KEPT ELEVATED POPS AND LIGHT
ACCUMULATIONS OF UP TO A FEW INCHES IN FOR THAT LIKELIHOOD.
BIGGER STORM WILL BE SURGE OF BRUTALLY COLD AIR IN ITS
WAKE...BRINGING THE COLDEST AIR OF THE SEASON TO PA. THE COLDEST
TEMPS /AND WIND CHILLS/ ARRIVE SAT NIGHT AND CONTINUE INTO
SUNDAY...WITH COLDEST STRAIGHT- UP TEMP READINGS SUN NIGHT WHEN
GEFS MEAN 850 MB TEMPS DROP TO -24 TO -28C ACROSS CENTRAL PENN.
AFTERNOON HIGHS SUNDAY WILL REMAIN BELOW ZERO ACROSS THE NORTHERN
MOUNTAINS AND LAUREL HIGHLANDS...AND MAINLY IN THE SINGLE DIGITS
ABOVE ZERO ELSEWHERE. TO COMPLICATE MATTERS...STRONG NORTHWEST
WIND GUSTS ANTICIPATED OVER 40 MPH SAT NIGHT AND EARLY SUNDAY
WILL BRING ANOTHER ROUND OF DANGEROUS...AND EVEN COLDER WIND
CHILLS OF 20 TO 30 BELOW ZERO. THOUGH WINDS WILL GRADUALLY RELAX
INTO MON...COMBINATION OF COLD TEMPS AND WIND JUSTIFIES THE WIND
CHILL WATCH CURRENTLY IN EFFECT THROUGH THAT 36HR PERIOD. THIS
WILL LIKELY NEED TO BE UPGRADED TO A WARNING AS EVENT WINDOW
APPROACHES. WILL ALSO NEED TO STRONGLY CONSIDER A WIND ADVISORY
ESP FOR HIGHER TERRAIN AND NW-SE ALIGNED VALLEYS ACROSS SOUTHERN
AREAS SAT NIGHT INTO EARLY SUN WITH PEAK WIND GUSTS IN THE 40-50
MPH RANGE.
RECORD LOWS FOR THE DATE EARLY MONDAY APPEAR LIKELY. LOWS EARLY
MONDAY MORNING UNDER CLEAR TO PARTLY CLOUDY SKIES WITH DIMINISHING
WIND WILL EASILY AVERAGE 10-15 BELOW ZERO ACROSS THE NRN AND
WESTERN MTNS...AND 5-10 BELOW ZERO THROUGHOUT MUCH OF THE CENTRAL
RIDGE AND VALLEY REGION. SOME PROTECTED VALLEYS ACROSS THE NORTH
COULD DIP TO NEAR 25 BELOW BETWEEN 09-12Z MONDAY. SURFACE HIGH
WILL PROPAGATE ACROSS CENTRAL PA MONDAY AND MONDAY NIGHT...MOVING
OFFSHORE ON TUESDAY.
STILL AT LEAST SOME POTENTIAL INDICATED FOR SOME PHASING OF
NORTHERN AND SOUTHERN STREAM WAVES OVER THE GULF COAST AND
SOUTHEASTERN U.S. BY LATER TUE INTO WED...BRINGING THE CHANCE OF
SNOW TO THE REGION. HOWEVER...MODEL TRENDS OVER PREVIOUS FEW DAYS
CONTINUE TO LEND CREEDENCE TOWARD A MORE SUPPRESSED/FLATTER
SOUTHERN STREAM SYSTEM WITH THE ARCTIC AIR DOMINATING THE GREAT
LAKES REGION AND NE U.S. AND THE BULK OF ANY STEADIER/STRATIFORM
PRECIP STAYING CONFINED TO THE SE U.S. AND MAYBE THE VIRGINIAS.
YET ANOTHER SURGE OF EXTREMELY COLD AIR RIDES IN ON PERSISTENT
NORTHWEST LATE NEXT WEEK...AS A MASSIVE RIDGE OF SURFACE HIGH
PRESSURE COVERS THE EASTERN HALF OF THE CONUS.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
VFR PREVAILING THIS AFTERNOON...WITH HIGH PRESSURE OVER THE
AIRSPACE. SFC WINDS WILL CONTINUE TO SUBSIDE AND GRADUALLY BACK
TO THE WSW TONIGHT...AS LOW PRES TRACKS SE ACROSS THE UPPER GREAT
LAKES.
AN ACTIVE WINTER WX PERIOD IS SHAPING UP FOR THE WEEKEND WITH
WIDESPREAD SNOW AND REDUCED VISBYS ON SAT FOLLOWED BY STRONG
WINDS SAT NGT INTO EARLY SUNDAY. HIGH PRESSURE SHOULD RETURN VFR
TO THE AREA EARLY NEXT WEEK.
OUTLOOK...
SAT...BCMG MVFR/IFR IN -SN. STG FROPA. WNW SFC WND GUSTS 25-35KTS.
SUN...MVFR/IFR WEST IN -SHSN. VFR/MVFR CENTRAL AND EAST. WNW SFC
WND GUSTS 25-35KTS...GRADUALLY DIMINISHING WEST TO EAST.
MON...MVFR -SHSN EARLY WEST...BCMG VFR. VFR ELSEWHERE.
TUE...CHC OF PM SNOW.
WED...CHC OF AM SNOW.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR PAZ012-018-019-025>028-034>037-041-042-045-046-
049>053-056>059-063>066.
WINTER WEATHER ADVISORY FROM 7 AM SATURDAY TO MIDNIGHT EST
SUNDAY NIGHT FOR PAZ017-024-033.
WIND CHILL WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING
FOR PAZ004>006-010-011-017-024-033.
HIGH WIND WATCH FROM SATURDAY EVENING THROUGH SUNDAY MORNING
FOR PAZ036-056>059-063>066.
&&
$$
SYNOPSIS...DEVOIR/LAMBERT
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...DEVOIR/LAMBERT
LONG TERM...RXR
AVIATION...DEVOIR/STEINBUGL
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
905 PM CST SAT FEB 14 2015
.UPDATE...
ISSUED ANOTHER UPDATE TO FURTHER REDUCE POPS AND SNOW AMOUNTS IN
THE NEXT 6 HOURS. THE MAIN WAVE OF ENERGY WILL STILL INFLUENCE THE
REGION LATER TONIGHT INTO SUNDAY MORNING. STRONG WARM AIR
ADVECTION/ISENTROPIC LIFT ACROSS THE FAR NORTHEAST CWA COULD STILL
RESULT IN A HALF INCH OF SNOW OR SO BETWEEN 6Z AND 12Z. WILL
CONTINUE TO MONITOR AND ADJUST ACCORDINGLY.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
WATCHING AN AREA OF RADAR RETURNS ACROSS THE CENTRAL
DAKOTAS...WITH OBS SHOWING SNOW ACROSS ND BUT YET TO SEE ANYTHING
OF SIGNIFICANCE ACROSS SD. WEB CAM AT LEMMON DOES APPEAR TO SHOW
LIGHT SNOW HAS BEGUN. STILL A DECENT AMOUNT OF DRY AIR TO OVERCOME
BASED ON RAP SOUNDINGS BUT IMAGINE MBG WILL BEGIN REPORTING -SN
BEFORE TOO LONG. HAVE SCALED BACK SNOW AMOUNTS JUST A BIT ACROSS
THE EASTERN CWA GIVEN THE MOISTENING OF THE ATMOSPHERE THAT WILL
HAVE TO TAKE PLACE FIRST. SHOULD STILL BE ABLE TO SEE AROUND AN
INCH FOR MOST PLACES ALONG AND EAST OF THE JAMES VALLEY. SYSTEM
LOOKS TO BE OUT OF HERE BY SUNDAY AFTERNOON WITH WARMER
TEMPERATURES MOVING BACK IN. ANOTHER COLD FRONT IN ON TRACK TO
SWEEP SOUTH ACROSS THE AREA MONDAY AFTERNOON...BRINGING ANOTHER
SHOT OF GUSTY NORTH WINDS AND COLD AIR TO THE REGION.
.LONG TERM...TUESDAY THROUGH SATURDAY
VERY GOOD AGREEMENT WITH THE MODELS IN THE LONG TERM WITH THE UPPER
LEVEL LONG WAVE PATTERN ALONG WITH THE SURFACE FEATURES. THE LONG
TERM LOOKS TO HAVE MAINLY BELOW TO MUCH BELOW NORMAL TEMPERATURES
THROUGH AT THE LEAST TUESDAY...WEDNESDAY AND THURSDAY. A LARGE UPPER
LEVEL LOW PRESSURE TROUGH ACROSS EASTERN CANADA AND THE EASTERN US
THROUGH MOST OF THE PERIOD WILL BRING PREVAILING FLOW FROM CANADA
AND THE ARCTIC. AT THE SURFACE...A COUPLE HIGH PRESSURE AREAS WILL
MOVE ACROSS THE REGION FROM THE NORTH. THERE WILL ALSO BE A FEW
WEAK UPPER LEVEL SHORT WAVE TROUGHS AND SURFACE COLD FRONTS MOVING
THROUGH BRINGING SOME CHANCES OF LIGHT SNOW/FLURRIES WITH THEM.
LEFT IT MAINLY DRY THROUGH THE LONG TERM AT THIS TIME. TEMPERATURES
MAY RISE CLOSER TO NORMAL TO SLIGHTLY ABOVE NORMAL OUT WEST BY
FRIDAY AND SATURDAY.
&&
.AVIATION...
00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
LIGHT TO MODERATE SNOW SHOWERS ARE MOVING FROM WEST TO EAST
ACROSS THE CENTRAL DAKOTAS THIS EVENING. SNOW WILL ENCOUNTER DRIER
AIR AS IT MOVES EAST...HOWEVER MODELS DO SHOW THE COLUMN
SATURATING QUICKLY. SNOW IS EXPECTED TO REACH THE KABR TAF SITE BY
2Z...AND THE KATY TAF SITE BY 4Z. IFR CONDITIONS CAN BE EXPECTED
AS SNOW MOVES OVERHEAD...WITH BRIEF LIFR CONDITIONS POSSIBLE. MVFR
STRATUS WILL STICK AROUND THROUGH MOST OF THE NIGHT BEFORE VFR
CONDITIONS RETURN BY EARLY SUNDAY MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...SERR
SHORT TERM...TMT
LONG TERM...MOHR
AVIATION...SERR
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
655 PM CST SAT FEB 14 2015
.UPDATE...
FIRST UPDATE TO NARROW THE AREA OF POPS AND REDUCED SNOWFALL
AMOUNTS THIS EVENING. THE 00Z SOUNDING AT KABR IS SHOWING AN
EXTREMELY DRY LOW LEVEL LAYER /800 MB DEWPOINT DEPRESSION NEAR 40
C/. MODELS SHOW THE LAYER SATURATING EVENTUALLY...BUT CONFIDENCE
IS LOW IN HOW QUICKLY THIS WILL HAPPEN. THE MAIN FORCING WITH THE
UPPER WAVE DOES LOOK LIKE IT IS YET TO REACH THIS REGION...SO
PERHAPS AT THAT POINT SNOWFALL WILL KICK IN AGAIN. WILL MONITOR
AND MAKE ADJUSTMENTS AS NECESSARY THIS EVENING. AT THIS POINT IT
SEEMS A STRETCH TO ACCUMULATE AN INCH OF SNOW ANYWHERE IN OUR CWA.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
WATCHING AN AREA OF RADAR RETURNS ACROSS THE CENTRAL
DAKOTAS...WITH OBS SHOWING SNOW ACROSS ND BUT YET TO SEE ANYTHING
OF SIGNIFICANCE ACROSS SD. WEB CAM AT LEMMON DOES APPEAR TO SHOW
LIGHT SNOW HAS BEGUN. STILL A DECENT AMOUNT OF DRY AIR TO OVERCOME
BASED ON RAP SOUNDINGS BUT IMAGINE MBG WILL BEGIN REPORTING -SN
BEFORE TOO LONG. HAVE SCALED BACK SNOW AMOUNTS JUST A BIT ACROSS
THE EASTERN CWA GIVEN THE MOISTENING OF THE ATMOSPHERE THAT WILL
HAVE TO TAKE PLACE FIRST. SHOULD STILL BE ABLE TO SEE AROUND AN
INCH FOR MOST PLACES ALONG AND EAST OF THE JAMES VALLEY. SYSTEM
LOOKS TO BE OUT OF HERE BY SUNDAY AFTERNOON WITH WARMER
TEMPERATURES MOVING BACK IN. ANOTHER COLD FRONT IN ON TRACK TO
SWEEP SOUTH ACROSS THE AREA MONDAY AFTERNOON...BRINGING ANOTHER
SHOT OF GUSTY NORTH WINDS AND COLD AIR TO THE REGION.
.LONG TERM...TUESDAY THROUGH SATURDAY
VERY GOOD AGREEMENT WITH THE MODELS IN THE LONG TERM WITH THE UPPER
LEVEL LONG WAVE PATTERN ALONG WITH THE SURFACE FEATURES. THE LONG
TERM LOOKS TO HAVE MAINLY BELOW TO MUCH BELOW NORMAL TEMPERATURES
THROUGH AT THE LEAST TUESDAY...WEDNESDAY AND THURSDAY. A LARGE UPPER
LEVEL LOW PRESSURE TROUGH ACROSS EASTERN CANADA AND THE EASTERN US
THROUGH MOST OF THE PERIOD WILL BRING PREVAILING FLOW FROM CANADA
AND THE ARCTIC. AT THE SURFACE...A COUPLE HIGH PRESSURE AREAS WILL
MOVE ACROSS THE REGION FROM THE NORTH. THERE WILL ALSO BE A FEW
WEAK UPPER LEVEL SHORT WAVE TROUGHS AND SURFACE COLD FRONTS MOVING
THROUGH BRINGING SOME CHANCES OF LIGHT SNOW/FLURRIES WITH THEM.
LEFT IT MAINLY DRY THROUGH THE LONG TERM AT THIS TIME. TEMPERATURES
MAY RISE CLOSER TO NORMAL TO SLIGHTLY ABOVE NORMAL OUT WEST BY
FRIDAY AND SATURDAY.
&&
.AVIATION...
00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
LIGHT TO MODERATE SNOW SHOWERS ARE MOVING FROM WEST TO EAST
ACROSS THE CENTRAL DAKOTAS THIS EVENING. SNOW WILL ENCOUNTER DRIER
AIR AS IT MOVES EAST...HOWEVER MODELS DO SHOW THE COLUMN
SATURATING QUICKLY. SNOW IS EXPECTED TO REACH THE KABR TAF SITE BY
2Z...AND THE KATY TAF SITE BY 4Z. IFR CONDITIONS CAN BE EXPECTED
AS SNOW MOVES OVERHEAD...WITH BRIEF LIFR CONDITIONS POSSIBLE. MVFR
STRATUS WILL STICK AROUND THROUGH MOST OF THE NIGHT BEFORE VFR
CONDITIONS RETURN BY EARLY SUNDAY MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...SERR
SHORT TERM...TMT
LONG TERM...MOHR
AVIATION...SERR
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
541 PM CST SAT FEB 14 2015
.UPDATE...
SEE THE UPDATED AVIATION DISCUSSION BELOW.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
WATCHING AN AREA OF RADAR RETURNS ACROSS THE CENTRAL
DAKOTAS...WITH OBS SHOWING SNOW ACROSS ND BUT YET TO SEE ANYTHING
OF SIGNIFICANCE ACROSS SD. WEB CAM AT LEMMON DOES APPEAR TO SHOW
LIGHT SNOW HAS BEGUN. STILL A DECENT AMOUNT OF DRY AIR TO OVERCOME
BASED ON RAP SOUNDINGS BUT IMAGINE MBG WILL BEGIN REPORTING -SN
BEFORE TOO LONG. HAVE SCALED BACK SNOW AMOUNTS JUST A BIT ACROSS
THE EASTERN CWA GIVEN THE MOISTENING OF THE ATMOSPHERE THAT WILL
HAVE TO TAKE PLACE FIRST. SHOULD STILL BE ABLE TO SEE AROUND AN
INCH FOR MOST PLACES ALONG AND EAST OF THE JAMES VALLEY. SYSTEM
LOOKS TO BE OUT OF HERE BY SUNDAY AFTERNOON WITH WARMER
TEMPERATURES MOVING BACK IN. ANOTHER COLD FRONT IN ON TRACK TO
SWEEP SOUTH ACROSS THE AREA MONDAY AFTERNOON...BRINGING ANOTHER
SHOT OF GUSTY NORTH WINDS AND COLD AIR TO THE REGION.
.LONG TERM...TUESDAY THROUGH SATURDAY
VERY GOOD AGREEMENT WITH THE MODELS IN THE LONG TERM WITH THE UPPER
LEVEL LONG WAVE PATTERN ALONG WITH THE SURFACE FEATURES. THE LONG
TERM LOOKS TO HAVE MAINLY BELOW TO MUCH BELOW NORMAL TEMPERATURES
THROUGH AT THE LEAST TUESDAY...WEDNESDAY AND THURSDAY. A LARGE UPPER
LEVEL LOW PRESSURE TROUGH ACROSS EASTERN CANADA AND THE EASTERN US
THROUGH MOST OF THE PERIOD WILL BRING PREVAILING FLOW FROM CANADA
AND THE ARCTIC. AT THE SURFACE...A COUPLE HIGH PRESSURE AREAS WILL
MOVE ACROSS THE REGION FROM THE NORTH. THERE WILL ALSO BE A FEW
WEAK UPPER LEVEL SHORT WAVE TROUGHS AND SURFACE COLD FRONTS MOVING
THROUGH BRINGING SOME CHANCES OF LIGHT SNOW/FLURRIES WITH THEM.
LEFT IT MAINLY DRY THROUGH THE LONG TERM AT THIS TIME. TEMPERATURES
MAY RISE CLOSER TO NORMAL TO SLIGHTLY ABOVE NORMAL OUT WEST BY
FRIDAY AND SATURDAY.
&&
.AVIATION...
00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
LIGHT TO MODERATE SNOW SHOWERS ARE MOVING FROM WEST TO EAST
ACROSS THE CENTRAL DAKOTAS THIS EVENING. SNOW WILL ENCOUNTER DRIER
AIR AS IT MOVES EAST...HOWEVER MODELS DO SHOW THE COLUMN
SATURATING QUICKLY. SNOW IS EXPECTED TO REACH THE KABR TAF SITE BY
2Z...AND THE KATY TAF SITE BY 4Z. IFR CONDITIONS CAN BE EXPECTED
AS SNOW MOVES OVERHEAD...WITH BRIEF LIFR CONDITIONS POSSIBLE. MVFR
STRATUS WILL STICK AROUND THROUGH MOST OF THE NIGHT BEFORE VFR
CONDITIONS RETURN BY EARLY SUNDAY MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...SERR
SHORT TERM...TMT
LONG TERM...MOHR
AVIATION...SERR
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1123 AM CST FRI FEB 13 2015
.UPDATE...
ISSUED AT 939 AM CST FRI FEB 13 2015
INCREASED THE SNOW CHANCES FOR THE REST OF THE MORNING INTO THE
AFTERNOON ACROSS THE NORTHERN SECTIONS OF THE AREA. PERSISTENT
LIGHT SNOW HAS BEEN FALLING AHEAD OF THE APPROACHING COLD FRONT
AND BOTH THE 13.12Z NAM AND 13.14Z RAP SHOW A SHORT WAVE TROUGH
WILL PASS THROUGH NORTHERN WISCONSIN AS THE COLD FRONT COMES
THROUGH. THIS WAVE LOOKS TO BE STRONG ENOUGH TO PRODUCE A PERIOD
OF MODERATE TO STRONG PV ADVECTION IN THE 500-300 MB LAYER ALONG
WITH WEAK TO MODERATE QG CONVERGENCE IN THE 1000-500 MB LAYER.
IN THE WARM SECTOR AHEAD OF THE COLD FRONT THERE SHOULD ALSO BE
BETWEEN 2 AND 4 UBAR/S OF UP GLIDE ON THE 285K SURFACE. SNOWFALL
AMOUNTS SHOULD REMAIN LIGHT WITH ACCUMULATIONS OF LESS THAN AN
INCH FROM THIS ACTIVITY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 235 AM CST FRI FEB 13 2015
UPPER LEVEL SHORTWAVE TROUGH DROPPING SOUTH/SOUTHEAST OUT OF CANADA
TO ACROSS THE GREAT LAKES SAT. SFC FRONT/LOW WILL DRIVE AHEAD OF THE
TROUGH...SLIDING ACROSS THE REGION TODAY. WARM AIR ADVECTION IN THE
850-700 MB LAYER AHEAD OF THE SFC BOUNDARY...ALONG WITH UPGLIDE ON
THE 280-295 K SFCS. LATEST FOG/STRATUS SATELLITE IMAGERY POINTS TO A
LARGE EXPANSE OF CLOUDS TRACKING SOUTHEAST ACROSS MN...ASSOCIATED
WITH THE LOW LEVEL THERMODYNAMICS-SFC FRONT. SOME LIGHT SNOW ACROSS
NORTHERN PORTIONS OF MN. BUFKIT SOUNDINGS VIA THE RAP/NAM/GFS
SUGGEST MAINLY NEAR SFC-MID LEVEL SATURATION. PROFILES ARE SOMEWHAT
MESSY IN THAT THE MOISTURE PROFILE IS NOT WELL DEFINED. SHOULD BE
COLD ENOUGH FOR ICE...ALTHOUGH COLDEST ICE BEARING LAYER LOOKS NEAR
SFC RATHER THAN A LOFT. OVERALL...NOT EXPECTING MUCH FOR
ACCUMULATIONS AND BEST CHANCES WILL BE THIS MORNING - HIGHER IN THE
I-94 CORRIDOR NORTHEAST.
WHAT THIS SHORTWAVE LACKS IN PCPN IT WILL MAKE UP FOR WITH STRONG
WINDS AND BITTER COLD.
SIGNIFICANT TIGHTENING IN THE SFC PRESSURE GRADIENT TONIGHT INTO
SATURDAY AS THE UPPER LEVEL TROUGH DROPS IN. STRONG COLD AIR
ADVECTION AND SINKING AIR VIA QG DIVERGENCE MAXED BETWEEN 12-18Z
SAT. SFC PRESSURE GRADIENT MAGNITUDES CLIMB ABOVE 40 KTS FOR THE
EASTERN 1/2 OF WI SAT...WITH BUFKIT SOUNDINGS AT RST/LSE MIXING DOWN
LOW 30 KTS. WINDS WILL BE ON THE INCREASE LATER THIS AFTERNOON...BUT
SHOULD START TO RAMP UP OVERNIGHT...PERSISTING INTO SATURDAY
AFTERNOON.
COLD AIR SURGES IN TONIGHT...WITH LOW 20S BELOW ZERO AT 925 MB SAT
AFTERNOON THROUGH SUNDAY. SUNDAY LOOKS TO BE THE COLDEST MORNING AS
HIGH PRESSURE STARTS TO APPROACH FROM THE NORTHERN PLAINS.
RADIATIONAL COOLING...WITH A LIGHTER WIND FIELD AND MOSTLY CLEAR
SKIES...WILL SUPPORT LOWS IN THE TEENS TO NEAR 20 BELOW ZERO.
THE COMBINATION OF THE STRONG WINDS AND TUMBLING TEMPS MAKE WIND
CHILL ADVISORIES LIKELY FOR A BULK OF THE REGION LATE TONIGHT
THROUGH SAT MORNING. DESPITE MUCH LIGHTER WINDS FOR SAT NIGHT/SUN
MORNING...ANOTHER ADVISORY MAY BE NEEDED AS JUST A SLIGHT STIR OF 5
TO 10 KTS COULD DROP WIND CHILLS INTO THE MID -20S.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 235 AM CST FRI FEB 13 2015
EXTENDED MODELS IN GOOD AGREEMENT WITH KEEPING THE REGION UNDER
NORTHWEST FLOW FOR MUCH OF NEXT WEEK. ECMWF/GFS/GEM ALL POINT TO A
FAIRLY ACTIVE FLOW WITH BITS OF ENERGY SPINNING THROUGH THE
FLOW...BUT NOTHING OVERLY DISTINCT AT THIS TIME...OR OF APPRECIABLE
STRENGTH. LIKELY SEE SOME LIGHT SNOW OR FLURRIES FROM TIME TO
TIME...BUT AMOUNTS LOOK MINIMAL.
ONE SUCH DAY LOOKS LIKE SUNDAY NIGHT INTO MONDAY. AN UPPER LEVEL
SHORTWAVE IS SLATED TO SLIDE ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY...WITH SOME MOSTLY MID-UPPER LEVEL QG CONVERGENCE WITH IT.
850-700MB WARM AIR ADVECTION LEADS THE SHORTWAVE ACROSS THE REGION.
QUITE A LOT OF DRY/COLD AIR FOR THIS SYSTEM TO BATTLE AS IT MOVES IN
THOUGH...AND MUCH OF ITS FORCING WILL HAVE TO GO INTO SATURATION.
PROBABLY HAS ENOUGH LIFT AND EVENTUAL SATURATION FOR SOME LIGHT SNOW-
FLURRIES SUNDAY NIGHT THROUGH MONDAY. AMOUNTS SHOULD BE HELD IN
CHECK THOUGH...AND LOOK MINIMAL AT THIS TIME.
WILL LET THE CONSENSUS SOLUTION SORT OUT SNOW CHANCES BEYOND THIS
PERIOD.
MORE SIGNIFICANTLY WILL BE THE ABUNDANCE OF COLD AIR THE NORTHWEST
FLOW WILL BRING. CPC 6-10 AND 8-14 DAY OUTLOOKS KEEP THE REGION IN
HIGH PROBABILITIES FOR BELOW NORMALS TEMPERATURES - IN EXCESS OF 80
PERCENT. NAEFS 850 MB TEMP ANOMALIES ARE GENERALLY -1 TO -3 THROUGH
THE PERIOD. ITS GOING TO STAY COLD THROUGH THE NEW WORK WEEK. SOME
INDICATIONS THAT THE FOLLOWING WEEKEND TEMPS COULD MODERATE A BIT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1123 AM CST FRI FEB 13 2015
THE COLD FRONT CONTINUES TO ADVANCE SOUTHEAST AND STILL LOOKS TO
BE ON TRACK TO PASS THROUGH BOTH TAF SITES LATE THIS AFTERNOON.
ONCE THE FRONT PASSES THROUGH...THE WINDS WILL SWITCH AROUND TO
THE NORTHWEST AND BECOME GUSTY. HOWEVER...THE STRONGEST WINDS WILL
NOT OCCUR UNTIL LATE TONIGHT INTO SATURDAY MORNING WHEN THE 13.12Z
NAM SHOWS THE STEEPEST LOW LEVEL LAPSE RATES WILL BE IN PLACE WITH
WINDS OF 30 KNOTS AT THE TOP OF THE MIXED LAYER. THIS MIXED LAYER
ALSO LOOKS LIKE IT WILL BE SATURATED FOR MVFR CEILINGS AND WITH
SOME LIFT THROUGH THIS COLUMN FROM THE PASSAGE OF THE STRONG UPPER
LEVEL SHORT WAVE AND LOW LEVEL CYCLONIC FLOW...WOULD EXPECT TO SEE
SOME FLURRIES AT BOTH TAF SITES. IT LOOKS LIKE DRIER AIR WILL
START TO MOVE IN SATURDAY MORNING TO ALLOW THE CLOUDS TO SCATTER
OUT...BUT THE WINDS WILL REMAIN GUSTY THROUGH THE MORNING AS THE
STEEP LAPSE RATES REMAIN IN PLACE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...04
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
939 AM CST FRI FEB 13 2015
.UPDATE...
ISSUED AT 939 AM CST FRI FEB 13 2015
INCREASED THE SNOW CHANCES FOR THE REST OF THE MORNING INTO THE
AFTERNOON ACROSS THE NORTHERN SECTIONS OF THE AREA. PERSISTENT
LIGHT SNOW HAS BEEN FALLING AHEAD OF THE APPROACHING COLD FRONT
AND BOTH THE 13.12Z NAM AND 13.14Z RAP SHOW A SHORT WAVE TROUGH
WILL PASS THROUGH NORTHERN WISCONSIN AS THE COLD FRONT COMES
THROUGH. THIS WAVE LOOKS TO BE STRONG ENOUGH TO PRODUCE A PERIOD
OF MODERATE TO STRONG PV ADVECTION IN THE 500-300 MB LAYER ALONG
WITH WEAK TO MODERATE QG CONVERGENCE IN THE 1000-500 MB LAYER.
IN THE WARM SECTOR AHEAD OF THE COLD FRONT THERE SHOULD ALSO BE
BETWEEN 2 AND 4 UBAR/S OF UP GLIDE ON THE 285K SURFACE. SNOWFALL
AMOUNTS SHOULD REMAIN LIGHT WITH ACCUMULATIONS OF LESS THAN AN
INCH FROM THIS ACTIVITY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 235 AM CST FRI FEB 13 2015
UPPER LEVEL SHORTWAVE TROUGH DROPPING SOUTH/SOUTHEAST OUT OF CANADA
TO ACROSS THE GREAT LAKES SAT. SFC FRONT/LOW WILL DRIVE AHEAD OF THE
TROUGH...SLIDING ACROSS THE REGION TODAY. WARM AIR ADVECTION IN THE
850-700 MB LAYER AHEAD OF THE SFC BOUNDARY...ALONG WITH UPGLIDE ON
THE 280-295 K SFCS. LATEST FOG/STRATUS SATELLITE IMAGERY POINTS TO A
LARGE EXPANSE OF CLOUDS TRACKING SOUTHEAST ACROSS MN...ASSOCIATED
WITH THE LOW LEVEL THERMODYNAMICS-SFC FRONT. SOME LIGHT SNOW ACROSS
NORTHERN PORTIONS OF MN. BUFKIT SOUNDINGS VIA THE RAP/NAM/GFS
SUGGEST MAINLY NEAR SFC-MID LEVEL SATURATION. PROFILES ARE SOMEWHAT
MESSY IN THAT THE MOISTURE PROFILE IS NOT WELL DEFINED. SHOULD BE
COLD ENOUGH FOR ICE...ALTHOUGH COLDEST ICE BEARING LAYER LOOKS NEAR
SFC RATHER THAN A LOFT. OVERALL...NOT EXPECTING MUCH FOR
ACCUMULATIONS AND BEST CHANCES WILL BE THIS MORNING - HIGHER IN THE
I-94 CORRIDOR NORTHEAST.
WHAT THIS SHORTWAVE LACKS IN PCPN IT WILL MAKE UP FOR WITH STRONG
WINDS AND BITTER COLD.
SIGNIFICANT TIGHTENING IN THE SFC PRESSURE GRADIENT TONIGHT INTO
SATURDAY AS THE UPPER LEVEL TROUGH DROPS IN. STRONG COLD AIR
ADVECTION AND SINKING AIR VIA QG DIVERGENCE MAXED BETWEEN 12-18Z
SAT. SFC PRESSURE GRADIENT MAGNITUDES CLIMB ABOVE 40 KTS FOR THE
EASTERN 1/2 OF WI SAT...WITH BUFKIT SOUNDINGS AT RST/LSE MIXING DOWN
LOW 30 KTS. WINDS WILL BE ON THE INCREASE LATER THIS AFTERNOON...BUT
SHOULD START TO RAMP UP OVERNIGHT...PERSISTING INTO SATURDAY
AFTERNOON.
COLD AIR SURGES IN TONIGHT...WITH LOW 20S BELOW ZERO AT 925 MB SAT
AFTERNOON THROUGH SUNDAY. SUNDAY LOOKS TO BE THE COLDEST MORNING AS
HIGH PRESSURE STARTS TO APPROACH FROM THE NORTHERN PLAINS.
RADIATIONAL COOLING...WITH A LIGHTER WIND FIELD AND MOSTLY CLEAR
SKIES...WILL SUPPORT LOWS IN THE TEENS TO NEAR 20 BELOW ZERO.
THE COMBINATION OF THE STRONG WINDS AND TUMBLING TEMPS MAKE WIND
CHILL ADVISORIES LIKELY FOR A BULK OF THE REGION LATE TONIGHT
THROUGH SAT MORNING. DESPITE MUCH LIGHTER WINDS FOR SAT NIGHT/SUN
MORNING...ANOTHER ADVISORY MAY BE NEEDED AS JUST A SLIGHT STIR OF 5
TO 10 KTS COULD DROP WIND CHILLS INTO THE MID -20S.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 235 AM CST FRI FEB 13 2015
EXTENDED MODELS IN GOOD AGREEMENT WITH KEEPING THE REGION UNDER
NORTHWEST FLOW FOR MUCH OF NEXT WEEK. ECMWF/GFS/GEM ALL POINT TO A
FAIRLY ACTIVE FLOW WITH BITS OF ENERGY SPINNING THROUGH THE
FLOW...BUT NOTHING OVERLY DISTINCT AT THIS TIME...OR OF APPRECIABLE
STRENGTH. LIKELY SEE SOME LIGHT SNOW OR FLURRIES FROM TIME TO
TIME...BUT AMOUNTS LOOK MINIMAL.
ONE SUCH DAY LOOKS LIKE SUNDAY NIGHT INTO MONDAY. AN UPPER LEVEL
SHORTWAVE IS SLATED TO SLIDE ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY...WITH SOME MOSTLY MID-UPPER LEVEL QG CONVERGENCE WITH IT.
850-700MB WARM AIR ADVECTION LEADS THE SHORTWAVE ACROSS THE REGION.
QUITE A LOT OF DRY/COLD AIR FOR THIS SYSTEM TO BATTLE AS IT MOVES IN
THOUGH...AND MUCH OF ITS FORCING WILL HAVE TO GO INTO SATURATION.
PROBABLY HAS ENOUGH LIFT AND EVENTUAL SATURATION FOR SOME LIGHT SNOW-
FLURRIES SUNDAY NIGHT THROUGH MONDAY. AMOUNTS SHOULD BE HELD IN
CHECK THOUGH...AND LOOK MINIMAL AT THIS TIME.
WILL LET THE CONSENSUS SOLUTION SORT OUT SNOW CHANCES BEYOND THIS
PERIOD.
MORE SIGNIFICANTLY WILL BE THE ABUNDANCE OF COLD AIR THE NORTHWEST
FLOW WILL BRING. CPC 6-10 AND 8-14 DAY OUTLOOKS KEEP THE REGION IN
HIGH PROBABILITIES FOR BELOW NORMALS TEMPERATURES - IN EXCESS OF 80
PERCENT. NAEFS 850 MB TEMP ANOMALIES ARE GENERALLY -1 TO -3 THROUGH
THE PERIOD. ITS GOING TO STAY COLD THROUGH THE NEW WORK WEEK. SOME
INDICATIONS THAT THE FOLLOWING WEEKEND TEMPS COULD MODERATE A BIT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 542 AM CST FRI FEB 13 2015
A WARM FRONT PUSHING THROUGH THE AREA TODAY WILL PRODUCE POCKETS
OF LIGHT SNOW OR FLURRIES MAINLY THIS MORNING WITH CIGS TEETERING
BETWEEN VFR AND HIGHER-END MVFR. AN ARCTIC COLD FRONT WILL PLUNGE
THROUGH THE AREA TONIGHT WITH FROPA EXPECTED AT KRST AROUND 03Z
AND AT KLSE AROUND 05Z. THERE WILL LIKELY BE A FEW FLURRIES AGAIN
WITH THE COLD FRONTAL PASSAGE MAINLY ALONG AND EAST OF THE
MISSISSIPPI RIVER WITH CEILINGS RIGHT ON THE VFR/MVFR CUSP. PLAN
ON GUSTY NORTHWEST TONIGHT IN THE 15KT TO 30KT RANGE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...04
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1150 PM CST THU FEB 12 2015
.UPDATE...
ISSUED AT 911 PM CST THU FEB 12 2015
THE MAIN FOCUS THIS EVENING IS ON THE SNOW CHANCES OVERNIGHT INTO
FRIDAY. CURRENTLY...A BAND OF SNOW HAS DEVELOPED ALONG THE SOUTH
DAKOTA/MINNESOTA BORDER AND IS TRAILING TO THE SOUTHEAST AND
DIMINISHING AS IT GOES INTO WESTERN IOWA. THE NORTHERN EDGE OF IT
IS FADING QUICK AS WELL...SO THE QUESTION IS WITH WHETHER THERE
WILL BE ANY REDEVELOPMENT ALONG THIS BROAD LOW LEVEL WARM AIR
ADVECTION DRIFTING EAST ACROSS THE REGION. RAP THERMAL PROFILES
HAVE TRENDED TOWARD BEING MORE SATURATED WITH ENOUGH LIFT TO
PRODUCE SOME LIGHT SNOW AS THE WAA COMES THROUGH. BASED ON THE
12.12/18Z NAM/GFS/ECMWF/GEM...THERE APPEARS TO BE TWO MAIN AREAS
OF 850MB WAA WITH THE FIRST BEING ON THE BAND OF SNOW CURRENTLY
OFF TO THE WEST AND ANOTHER DROPPING DOWN ACROSS NORTHERN
MINNESOTA/WISCONSIN. IT APPEARS THAT OUR BEST SHOT AT SNOW COMES
WITH THIS SECOND SHOT OF WAA WHICH COMES IN SLOWER THAN PREVIOUS
TRENDS. SO...HAVE SLOWED DOWN THE SNOW CHANCES FOR OVERNIGHT INTO
TOMORROW BUT KEPT AMOUNTS THE SAME AT LESS THAN AN INCH.
&&
.SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)
ISSUED AT 251 PM CST THU FEB 12 2015
MAIN FCST CONCERNS THIS PERIOD...-SN CHANCES LATE TONIGHT/FRI
MORNING...FLURRY/-SHSN CHANCES WITH ARCTIC FRONTAL PASSAGE
FRI NIGHT...WINDS LATE FRI NIGHT...TEMPERATURES.
18Z DATA ANALYSIS HAD A 1036-1040MB CAN/ARCTIC HIGH FROM SOUTHWEST
ONT TO EASTERN KS...DRIFTING SLOWLY SOUTHEAST ACROSS THE MID/UPPER
MS VALLEY. GENERALLY CLEAR/SUNNY SKIES ACROSS MN/IA/WI UNDER THE
HIGH...WITH ONLY SOME HIGH CLOUDS AHEAD OF THE NEXT NORTHWEST FLOW
SHORTWAVE SPREADING OVER WESTERN MN. WINDS WERE LIGHT WITH WIND
CHILLS ABATING. EVEN WITH THE SUNSHINE...MID-DAY TEMPS ACROSS MUCH
OF MN/IA WI ONLY IN THE -10F TO +10F RANGE...SOME 10F-20F BELOW
NORMAL.
12.12Z MODELS INITIALIZED WILL AND PRESENT VERY SIMILAR SOLUTIONS
FOR TONIGHT THRU FRI NIGHT AS 2 NORTHWEST FLOW SYSTEMS IMPACT THE
REGION. TREND IS A LITTLE FLATTER/WEAKER WITH A SHORTWAVE TO RIPPLE
SOUTHEAST ACROSS THE REGION LATER TONIGHT/EARLY FRI...THEN A LITTLE
STRONGER/SLOWER WITH THE SHORTWAVE TO DROP IN FRI NIGHT. GIVEN THE
TIGHT CONSENSUS...SHORT-TERM FCST CONFIDENCE IS GOOD THIS CYCLE.
FOR THE SHORT TERM...ALL MODELS SHOWING MID/HIGH LEVEL MOISTURE AT
ABOVE 700MB TO INCREASE/THICKEN OVER THE REGION TONIGHT AS LOWER
LEVEL WARM ADVECTION GRADUALLY SPREADS EAST ACROSS THE AREA.
PREVIOUS FORECASTER TRENDED TONIGHTS LOWS LATE THIS EVENING THEN
STEADY/SLOWLY RISING OVERNIGHT...WHICH LOOKS GOOD. TIGHT SIGNAL
FOR THE 925-700MB MOISTURE IN THE WARM ADVECTION/LIFT AHEAD OF THE
LOWER LEVEL WAVE TO SPREAD INTO THE WEST END OF THE FCST AREA AROUND
06Z...NOT REACHING THE EAST END OF THE FCST AREA UNTIL AROUND 12Z
FRI. WEAKER/FLATTER TREND OF THE SHORTWAVE RESULTS IN LESS OF A
LIFTING SIGNAL ACROSS THE AREA LATER TONIGHT/FRI. ALL MODELS
HAVE TRENDED DRIER WITH THE QPF SINCE THE 11.12Z RUNS...BUT STILL
MANAGE TO SQUEEZE OUT SOME VERY LIGHT QPF AS THE ROUND OF LOWER
LEVEL THERMODYNAMIC FORCING PUSHES ACROSS THE FCST AREA. LIMITED -SN
CHANCES TO WHEN THE 925-700MB MOISTURE MOVES INTO/ACROSS THE FCST
AREA...AFTER MIDNIGHT TONIGHT THRU MAINLY FRI MORNING. MEASURABLE
SNOW CHANCES IN THE 30-40 PERCENT 06-18Z FRI LOOK GOOD FOR NOW.
APPEARS AROUND 1/2 INCH OF SNOW WOULD BE POSSIBLE IF THE STRONGER...
MORE SATURATED OF THE MODELS WERE TO VERIFY.
A WARMER DAY FRI WITH HIGHS NEAR NORMAL AS 925MB TEMPS WARM INTO THE
-6C TO -9C IN THE WARM ADVECTION WESTERLY FLOW. WARMUP IS SHORT
LIVED AS NEXT STRONG SHORTWAVE DROPS ACROSS LK SUPERIOR AND DRIVES A
STRONG ARCTIC FRONT SOUTH ACROSS THE AREA FRI NIGHT. SFC-850MB LAYER
GENERALLY REMAINS SATURATED FRI NIGHT...WITH SOME WEAK LIFT TO
ACCOMPANY THE FRONT AS THE COLD ADVECTION PUTS THE SQUEEZE ON THE
WATER HOLDING CAPACITY OF THE LOWER PORTION OF THE COLUMN. ADDED SCT
FLURRY MENTION TO GRIDS FOR FRI NIGHT. 925MB TEMPS CRASH BACK INTO
THE -16C TO -21C RANGE AFTER MIDNIGHT FRI NIGHT...WITH TEMPS A FEW
DEGREES EITHER SIDE OF 0F BY 12Z SAT. THIS WITH GRADIENT WINDS
AROUND 20KTS GUSTING 30-35KTS PRODUCING WIND CHILLS OF -10 TO -25 BY
12Z SAT. MAY YET NEED A WIND CHILL ADVISORY FOR NORTHERN PORTIONS
OF THE FCST AREA LATE FRI NIGHT. FAVORED THE MODEL/ENSEMBLE
CONSENSUS OF LOWS/HIGHS FOR TONIGHT THRU FRI NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 251 PM CST THU FEB 12 2015
FCST CONCERNS FOR SATURDAY THRU SUN NIGHT...COLD TEMPERATURES AS
ARCTIC HIGH PRESSURE DRIFTS ACROSS THE UPPER MIDWEST...-SN CHANCES
IN RETURNING WARM ADVECTION SUN NIGHT.
12.12Z MODELS IN GOOD AGREEMENT AS THE FRI NIGHT SHORTWAVE ROTATES
QUICKLY SOUTHEAST/OUT OF THE REGION. TIGHTER CONSENSUS FOR SLOW HGT
RISES LATER SAT/SAT NIGHT AS TROUGHING DEEPENS ALONG THE EAST COAST
AND AHEAD OF ANOTHER SHORTWAVE PASSING NEAR LK WINNIPEG BY 12Z SUN.
HGTS FALL AGAIN SUN/SUN NIGHT AS THIS ENERGY CARVES OUT MORE BROAD
TROUGHING OVER THE NORTH-CENTRAL CONUS. SOME SHORTWAVE DETAIL
DIFFERENCES BY SUN/SUN NIGHT BUT TREND IS FOR MORE TROUGHING/
SHORTWAVE ENERGY OVER THE NORTHERN PLAINS/UPPER MIDWEST FOR LATER
SUN/SUN NIGHT. FCST CONFIDENCE IN THE SAT THRU SUN NIGHT PERIOD IS
GOOD THIS CYCLE.
1040MB OR HIGHER ARCTIC HIGH TO BUILD ACROSS THE UPPER MIDWEST SAT
THRU SUN. TIGHT PRESSURE GRADIENT AND COLD ADVECTION ON THE FRONT
SIDE OF THE HIGH IS OVER THE AREA SAT. 925MB TEMPS PROGGED TO DROP
INTO THE -20C TO -25C RANGE BY 00Z SUN AND REMAIN THERE SAT NIGHT.
WITH NORTHWEST WINDS AROUND 20KTS GUSTING 25-35KTS MUCH OF SAT...
TEMPS WILL STRUGGLE TO WARM MUCH IF AT ALL. IF FRI NIGHT COLD
ADVECTION IS DELAYED A BIT...HIGHS SAT MAY BE IN THE 12-14Z RANGE
THEN DROP A FEW DEGREES FOR THE REST OF THE DAY. WIND CHILLS MUCH OF
SAT LOOKING TO BE IN THE -15 TO -25 RANGE AND APPEARS A WIND CHILL
ADVISORY WILL BE NEEDED FOR PORTIONS OF THE FCST AREA AT LEAST SAT
MORNING. SAT NIGHT SHAPING UP TO BE ONE OF THE COLDEST NIGHTS OF THE
2014-2015 WINTER WITH THE CENTER OF THE HIGH OVER WI/EASTERN IA AT
12Z SUN. LIGHT/CALM WINDS...MOSTLY CLEAR SKIES AND SNOW DEPTHS
MOSTLY 3 TO 8 INCHES...MOST LOCATIONS LOOKING AT LOWS OF -10F TO
-20F...PERHAPS AS LOW AS -30F IN THE SHELTERED LOW LAYING LOCATIONS.
WINDS WILL BE QUITE LIGHT SAT NIGHT INTO SUN MORNING...BUT WITH
TEMPS THAT COLD WILL LIKELY NEED A WIND CHILL ADVISORY FOR MOST IF
NOT ALL OF THE FCST AREA FOR LATER SAT NIGHT/SUN MORNING. SLOW
MODERATION STARTS SUN/SUN NIGHT AS THE CENTER OF THE HIGH DRIFTS
EAST OF THE AREA AND LOW LEVEL WARM ADVECTION RETURNS. TEMPS SUN/SUN
NIGHT STILL AROUND 20F BELOW NORMAL THOUGH. HIGHER LEVEL MOISTURE/
CLOUDS INCREASE THRU THE DAY SUNDAY WITH THE 925-700MB MOISTURE
PROGGED SPREAD WEST TO EAST ACROSS THE FCST AREA LATER SUN
AFTERNOON/SUN NIGHT. SMALL -SN CHANCE IN THE WEST END OF THE FCST
AREA SUN AFTERNOON AND A SMALL CHANCE ACROSS MUCH OF THE FCST AREA
SUN NIGHT REASONABLE FOR NOW. TRENDED TOWARD COLDER OF GUIDANCE LOWS
SAT NIGHT...OTHERWISE STAYED NEAR THE MODEL/ENSEMBLE CONSENSUS FOR
HIGHS/LOWS SAT/SUN/SUN NIGHT.
FOR MONDAY THRU THURSDAY...DAYS 4 TO 7...
MAIN FCST CONCERNS THIS PERIOD...SMALL -SN CHANCES CENTERED ON MON
AND AGAIN THU...BELOW NORMAL TEMPERATURES THRU THE PERIOD.
MEDIUM RANGE MODEL RUNS OF 12.00Z/12.12Z IN GOOD AGREEMENT FOR
ANOTHER STRONGER SHORTWAVE TROUGH TO BE DROPPING INTO THE NORTHERN
PLAINS MON...THEN MOVING INTO/ACROSS THE UPPER MIDWEST MON NIGHT
THRU TUE NIGHT. DIFFERENCES BY 12Z WED ON HOW QUICKLY THE TROUGH
AXIS WOULD MOVE EAST OF THE REGION...GFS FASTER...ECMWF SLOWER WITH
EACH HOLDING CONSISTENCY TO ITS PREVIOUS RUNS. GENERAL AGREEMENT
FOR THE TROUGHING TO SWING EAST OF THE AREA WED...WITH RISING HGTS
WED NIGHT INTO THU AHEAD OF ANOTHER SHORTWAVE TROUGH PROGGED TO DROP
SOUTH ACROSS MANITOBA. GIVEN THE GENERAL LARGER SCALE MODEL
AGREEMENT NEXT WEEK...DAY 4-7 FCST CONFIDENCE IS AVERAGE THIS CYCLE.
ROUND OF LOWER LEVEL WARM ADVECTION/ISENTROPIC LIFT TO SPREAD ACROSS
THE AREA MON INTO MON NIGHT AS THE WEEKEND ARCTIC HIGH MOVES FURTHER
EAST/SOUTH. SFC/LOWER LEVEL TROUGH WITH THE NEXT MID LEVEL SHORTWAVE
ENERGY TO PUSH ACROSS THE REGION AS WELL MON/MON NIGHT. SMALL -SN
CHANCES MON/MON NIGHT PER THE MODEL CONSENSUS REASONABLE FOR NOW
UNTIL THE AVAILABLE MOISTURE DETAILS COME INTO BETTER FOCUS. PASSING
SFC TROUGH USHERS ANOTHER CAN/ARCTIC HIGH INTO THE UPPER MIDWEST FOR
LATER MON NIGHT INTO WED. AFTER A BIT OF A WARMUP MON...925MB TEMPS
IN THE -8C TO -12C RANGE AT 00Z TUE...925MB TEMPS PROGGED BACK IN
THE -19 TO -23C RANGE BY 12Z WED. ON WED..MORE PROGRESSIVE GFS
SPREADS IN LOW LEVEL WARM ADVECTION WHILE ECMWF CONTINUES WITH
COLD ADVECTION. OVERALL DIFFERENCE OF 925MB TEMPS ON WED ONLY 2C
TO 4C...BUT NOT A LOT OF CONFIDENCE ON HIGHS GIVEN NORTHWEST VS.
SOUTHWEST LOW LEVEL FLOW AND CLOUD DIFFERENCES BETWEEN GFS/ECMWF.
MORE CONSISTENT SIGNAL FOR A STRONGER ROUND OF LOW LEVEL WARM
ADVECTION/LIFT AHEAD OF THE NEXT TROUGH TO SPREAD ACROSS THE
REGION THU. EVEN WITH THIS...NAEFS ENSEMBLE AVERAGE HAS LOW LEVEL
TEMPS 1-2 STANDARD DEVIATIONS BELOW NORMAL ON THU. MODEL/ENSEMBLE
CONSENSUS OF HIGHS/LOWS FOR MON-THU APPEARS WELL TRENDED FOR
NOW...REMAINING SOME 5 TO 15 DEGREES BELOW NORMAL NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1150 PM CST THU FEB 12 2015
THE MAIN FOCUS CONTINUES TO BE ON THE CHANCES FOR SNOW AND SUB-VFR
FLIGHT CONDITIONS AS IT MOVES THROUGH. IT STILL LOOKS LIKE THE
POTENTIAL FOR LIGHT SNOW WILL BE TOWARD DAYBREAK. CURRENTLY...THIS
SNOW IS DEVELOPING ACROSS NORTHERN MINNESOTA WITH CONDITIONS
MAINLY MVFR FROM LOW CEILINGS. A FEW SPOTS HAVE VISIBILITY DOWN
AROUND 2SM...BUT IT IS PRETTY BRIEF. WAS NOT CONFIDENT ENOUGH TO
DROP DOWN CONDITIONS TO IFR YET...BUT A BRIEF PERIOD OF IT WILL BE
POSSIBLE AS THIS SNOW COMES THROUGH FRIDAY MORNING. CONDITIONS ARE
EXPECTED TO IMPROVE GOING INTO THE AFTERNOON/EVENING AS WINDS COME
AROUND TO THE WEST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1028 PM CST THU FEB 12 2015
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SYNOPSIS...ISSUED AT 239 PM CST THU FEB 12 2015
WATER VAPOR LOOP AND RUC ANALYSIS REVEALS AMPLIFIED PATTERN
FEATURING WEST COAST RIDGE AND BROAD UPSTREAM TROF ACROSS MUCH OF
NORTH AMERICA. MODELS INDICATE THIS PATTERN WILL STAY IN PLACE OVER
MUCH OF NEXT WEEK ALLOWING FOR PERIODIC SURGES OF ARCTIC AIR INTO
THE REGION RESULTING IN BLO NORMAL TEMPS. MODELS ADVERTISE ONLY
PERIODIC LIGHT PCPN WITH A FEW CLIPPER SHORTWAVES TRAVERSING AREA.
&&
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 239 PM CST THU FEB 12 2015
MINS TEMP FCST TONIGHT COULD BE TRICKY AS WINDS WILL DIE OFF WITH
SFC RDG MOVING ACROSS THE AREA. ALSO WAA MID-HIGH CLOUDS WILL BE
SPREADING INTO THE AREA AHEAD OF SHORTWAVE AND ASSOC SFC LOW DIVING
DOWN FM CENTRAL CANADA. THESE CLOUDS DEPENDING ON HOW THICK THEY ARE
MAY TEMPER RADIATIONAL COOLING UNDER LIGHT WIND REGIME. GIVEN
UNCERTAINTY WITH CLOUD THICKNESS DECIDED TO USED A BLEND OF COLDER
BASE REG GEM/ECMWF TEMPS AND MOS GUIDE TEMPS WHICH WAS CLOSE TO PREV
FCST AND IN MEDIUM RANGE OF TEMP GUIDANCE.
BACKED OFF SLIGHTLY ON POPS FOR FRI AS MODELS INDICATE BEST MOISTURE
AND ISENTROPIC ASCENT STAYING GENERALLY NORTH OF WI CLOSER TO TRACK
OF SHORTWAVE AND ASSOC SFC LOW. HAVE POPS RANGING FROM HIGH CHC
(AROUND 50 PCT) NORTH TO LOWER CHC 30-40 POPS FOR SOUTHERN PORTIONS
OF CWA. WAA WL HELP TEMPS RECOVER TO AROUND 20F...BUT MAX TEMPS
PROBABLY WON/T OCCUR UNTIL LATE IN THE DAY SO ADJUSTED DIURNAL CURVE
ACCORDINGLY.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 233 PM CST THU FEB 12 2015
N-NW WINDS WILL BE ON THE INCREASE LATE FRIDAY NIGHT INTO SATURDAY
THANKS TO THE INCREASING PRESSURE GRADIENT BETWEEN THE EXITING SFC
LOW SHIFTING FROM JUST E OF LAKE SUPERIOR AT 00Z SATURDAY TO THE
LOWER GREAT LAKES SATURDAY AFTERNOON...AND THE COLD ARCTIC HIGH
SINKING ACROSS S CENTRAL CANADA AND INTO THE N PLAINS. WHILE THE
COLDEST AIR WILL REMAIN N-NE OF WI...STILL EXPECT 850MB TEMPS TO
BOTTOM OUT AROUND -27 TO -30C SATURDAY AFTERNOON. AS A
RESULT...STEADY TO FALLING TEMPERATRUES WILL BE COMMON SATURDAY AS
THIS COLDER AIR RUSHES IN. HIGHS SATURDAY MAY ONLY ONLY TOP OUT IN
THE -3 TO 7F RANGE /COLDEST NE/.
KEPT THE POTENTIAL FOR BLOWING SNOW WHERE POPS WERE OVER 14
PERCENT...AND WIND GUSTS WERE OVER 20KTS. THE BEST CHANCE OF SNOW
WILL BE OVER THE N ANE E TIER COUNTIES AS LAKE EFFECT ON STRONG
WINDS BLOW WELL INLAND AND INTO N WI.
UNDER A CLEARING SKY SATURDAY NIGHT...AND WITH WINDS OF 5-10KTS OUT
OF THE N-NNW...WIND CHILL READINGS OF 25 TO 30 BELOW ZERO WILL BE
POSSIBLE. LOOK FOR LATER UPDATES AND FORECASTS ON THIS ARCTIC
AIRMASS AND LOW WIND CHILLS.
GENEARALLY FOLLOWED A MODEL BLEND FOR MUCH OF THIS PERIOD. NO
SIGNIFICANT STORMS ANTICIPATED...BUT WITH COLD WEATHER CONTINUING.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1022 PM CST THU FEB 12 2015
EXPECT VFR CONDITIONS AT ALL TAF SITES OVERNIGHT...WITH
INCREASING MID-LEVEL CLOUDS ANTICIPATED. A CLIPPER LOW PRESSURE
WILL TRACK NORTH OF THE REGION ON FRIDAY...AND BRING SOME LIGHT
SNOW AND ASSOCIATED MVFR CONDITIONS DURING THE DAY. A STRONG COLD
FRONT WILL MOVE THROUGH THE FORECAST AREA DURING THE LATE AFT/EVG...
AND SHOULD BRING SCT SNOW SHOWERS/FLURRIES...MVFR CIGS AND
INCREASING NW WINDS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS.......VOSS
SHORT TERM.....VOSS
LONG TERM......KF
AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS TAUNTON MA
443 AM EST SUN FEB 15 2015
.SYNOPSIS...
A POWERFUL OFFSHORE STORM WILL RAPIDLY DEVELOP TODAY. THERE WILL
BE A PERIOD OF BLIZZARD CONDITIONS THIS SUNDAY MORNING...
ESPECIALLY TOWARD THE COASTS...WITH HURRICANE FORCE WIND GUSTS
ACROSS THE OUTER CAPE AND NANTUCKET. EXCEPTIONALLY COLD AIR...THE
COLDEST OF THE SEASON...FOLLOWS LATE SUNDAY INTO TUESDAY MORNING.
ANOTHER STORM SYSTEM IS EXPECTED BY MIDWEEK FOLLOWED BY ANOTHER
SURGE OF BITTER COLD.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
15/00Z SOUNDINGS ARE IMPRESSIVE. AS FAR WEST AS PITTSBURGH AND
CINCINNATI...NEAR DRY ADIABATIC LAPSE THROUGH A VERY DEEP LAYER.
ALSO SEEING SIGNS OF A TROPOPAUSE FOLD...WITH THE BASE OF THE
TROPOPAUSE AS LOW AS 700 MB OR SO. WE HAVE CONCERNS THE OFFSHORE
STORM WILL INTENSIFY EVEN MORE EXPLOSIVELY THAN PREVIOUSLY THOUGHT
LATER TODAY.
LATEST RUNS OF THE HI-RESOLUTION GUIDANCE TRYING TO BEAR THIS OUT.
SOME...LIKE THE HRRR AND REGIONAL CANADIAN...SHOWING AN IMPRESSIVE
BANDING SIGNATURE. AT THIS POINT...WE CONTINUE TO HAVE LITTLE
CONFIDENCE IN EXACTLY WHERE THIS BAND WILL ESTABLISH ITSELF. WHERE
IT DOES PERSIST FOR A TIME...WILL LIKELY SEE LOCALLY HEAVIER
SNOWFALL...WITH RATES OF 2-4 INCHES PER HOUR. THIS IS A
COMPLICATING THE TOTAL SNOWFALL FORECAST.
AS OF 4 AM...WATCHING AN IMPRESSIVE SNOW BAND MOVING SOUTH ACROSS
EASTERN MASSACHUSETTS. WEBCAMS SHOWING SNOW IS RAPIDLY PILING UP
ACROSS ESSEX COUNTY. FORTUNATELY...THIS BAND DOES SEEM TO BE
PROGRESSIVE. 15/08Z HRRR SEEMS TO HAVE THE RIGHT IDEA...SO WILL
LEAN HEAVILY IN THAT DIRECTION FOR TIMING. WILL CONTINUE TO
MONITOR ITS PROGRESS. WE EXPECT SOME CHANGES TO OUR SNOWFALL
FORECAST AS WE GET MORE INFORMATION LATER THIS MORNING. MOST OF
THE SNOWFALL WILL BE DONE BY NOON. THE EXCEPTION SHOULD BE ACROSS
THE OUTER CAPE AND NANTUCKET WHERE OCEAN-EFFECT SNOW WILL LIKELY
PERSIST A BIT LONGER.
WITH THE POTENTIAL FOR BLOWING SNOW ONCE THE WINDS PICK UP...ONE
POSSIBLE DECIDED TO EXPAND THE BLIZZARD WARNING ONE MORE TIER
WEST EARLIER THIS MORNING.
DECIDED TO LEAVE THE WINTER STORM WARNING ALONG AND WEST OF THE CT
RIVER. THE LATEST REPORTS WE HAVE INDICATE SOLID ADVISORY LEVEL
EVENT SO FAR. THINKING THE BRUNT OF THE SNOWFALL WILL BE MAINLY
EAST OF THIS AREA TODAY...BUT CANNOT COMPLETELY RULE OUT HEAVIER
SNOW BANDS MAKING IT THAT FAR WEST. WILL CONTINUE TO REEVALUATE
THIS RISK LATER THIS MORNING.
WITH THE STRONG MAINLY ONSHORE WINDS /N-NE DIRECTION/...WILL SEE
PROBLEMS WITH THE SUNDAY MORNING HIGH TIDE ACROSS THE NORMAL
PROBLEMATIC AREAS OF CAPE ANN AND THE SOUTH SHORE TO THE CAPE COD
BAY SHORELINE. PLEASE SEE THE COASTAL FLOOD SECTION BELOW.
FINALLY...AS THE ARCTIC AIR WORKS IN ON THE STRONG N-NW WINDS
LATER SUNDAY...WIND CHILL VALUES WILL DROP TO -10 TO -20 ACROSS
CENTRAL AND WESTERN AREAS WITH THE LOWEST VALUES ACROSS THE HIGHER
TERRAIN BY AROUND SUNSET. WIND CHILL WARNINGS REMAIN IN EFFECT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
WIND CHILL WARNINGS CONTINUE INTO MONDAY MORNING.
INTENSE LOW PRES WILL BE MOVING INTO NOVA SCOTIA TONIGHT WITH
STRONG NW WINDS DRAGGING DOWN THE COLDEST AIR OF THE SEASON INTO
SOUTHERN NEW ENGLAND. MAINLY DRY CONDITIONS AND MOSTLY CLEAR
SKIES...BUT OCEAN-EFFECT CLOUDS WILL LINGER OVER THE CAPE/ISLANDS
AND IT APPEARS SOME SNOW SHOWERS WILL AFFECT THE OUTER CAPE GIVEN
HOW EXTREME THE INSTABILITY WILL BE OVER THE OCEAN AS ARCTIC AIR
MOVES IN. ANY SNOW ACCUMULATION TONIGHT SHOULD BE LESS THAN AN
INCH AS MIXING DEPTH IS RATHER SHALLOW...MOSTLY BELOW 900 MB AND
TRAJECTORY WILL BE NW...WHICH WILL KEEP THE MAJORITY OF SNOW
SHOWERS OFFSHORE.
BLOWING SNOW WILL BE AN ISSUE FOR MOST OF TONIGHT...ESPECIALLY
TOWARD THE COASTS STILL EXPECTING WIND GUSTS UP TO 50 MPH EARLY
THIS EVENING ACROSS THE COASTAL PLAIN. WINDS GRADUALLY DIMINISH
THROUGH THE NIGHT...BUT STILL GUSTING TO 25-35 MPH OVERNIGHT...
AND UP TO 45 MPH OUTER CAPE/ISLANDS. CONSIDERABLE BLOWING SNOW
WITH REDUCED VISIBILITY.
THE MAIN STORY FOR TONIGHT INTO MONDAY MORNING WILL BE THE BITTER
COLD AND DANGEROUSLY LOW WIND CHILLS. TEMPERATURES WILL LIKELY BE
25-30 DEGREES BELOW NORMAL. EXPECTING WIND CHILLS 20 TO 30 BELOW
ZERO ACROSS THE COASTAL PLAIN...AND 30 TO 40 BELOW OVER THE
HIGHER ELEVATIONS IN CENTRAL AND WESTERN MA. THIS IS DANGEROUS
COLD. FROSTBITE ON EXPOSED FLESH CAN OCCUR QUICKLY.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
*/ HIGHLIGHTS...
- POTENTIAL MIDWEEK STORM SYSTEM MAINLY IN THE FORM OF SNOW
- CONTINUED BITTERLY COLD
- NO BREAK IN THE WEATHER PATTERN
- NEXT CHANCE OF WARMTH: SOMETIME SPRING INTO SUMMER
*/ OVERVIEW...
ENSEMBLE-MEAN PREFERENCE FORECAST. POSITIVE TELECONNECTION PATTERNS.
BROADER CYCLONIC FLOW CONTINUES THROUGH WHICH WE WILL SEE ADDITIONAL
WEATHER SYSTEMS FOLLOWED BY SHOTS OF COLD ARCTIC AIR. IT APPEARS WE
WILL NOT SEE A BREAK IN A PATTERN OVER THE NEXT WEEK. THE MASSIVE
AMOUNTS OF SNOW WILL REMAIN TO REMIND US JUST HOW AWFUL WINTER HAS
BEEN AND HOW WONDERFUL IT CAN BE LIVING IN NEW ENGLAND. HAPPY DAYS
ARE HERE AGAIN!
*/ DAILIES...
MONDAY INTO MONDAY NIGHT...
VERY COLD AND DRY. INITIAL BLUSTERY NW-WINDS YIELDING EXCEPTIONALLY
COLD WIND CHILL VALUES OF 15 TO 25 DEGREES BELOW-ZERO INTO MIDDAY.
WIND CHILL HEADLINES CONTINUING. WINDS RELAXING WHILE HIGHS TOP OUT
INTO THE SINGLE-DIGITS TO LOW-TEENS INTO THE LATER-HALF OF THE DAY.
SAVING CAVEAT IS ABUNDANT SUNSHINE.
LIGHT WINDS OVERNIGHT WITH A RENEWED SNOWPACK BENEATH HIGH PRESSURE.
PRIOR TO INCREASING LOW- TO MID-LEVEL CLOUDS FROM THE S...ANTICIPATE
RADIATIONAL COOLING ACROSS INTERIOR NEW ENGLAND. LOWS DROPPING WELL-
BELOW ZERO WITH LIKELY DRAINAGE LOCATIONS LOWER THAN 10-BELOW. HAVE
CONFIDENCE IN SUCH OUTCOMES AROUND THE MERRIMACK RIVER VALLEY.
TUESDAY INTO TUESDAY NIGHT...
PREFER ENSEMBLE-MEANS AND A CONSENSUS FORECAST SPREAD. NO PREFERENCE
WITH CONTINUED MODEL SPREAD. DOES APPEAR TO BE A WEAK-WAVE IMPULSE
ALONG THE OFFSHORE BAROCLINIC-ZONE LOW THAT INVOKES AN INFLECTION
LOW THAT UNDERGOES MATURATION DOWNSTREAM AS THE UPPER-LEVEL PATTERN
MEETS THE SURFACE REFLECTION. MUCH GREATER TILT / SEPARATION WITHIN
THE VERTICAL PRESSURE PATTERN RATHER THAN A NEARLY-STACKED SETUP. NO
CLOSED LOW INDICATIONS. THIS HAS BEEN CONSISTENTLY ADVERTISED WITHIN
EC-ENS ALONG WITH A COLD SOLUTION. HOPEFULLY NO SURPRISES WITH LATER
FORECAST GUIDANCE.
SO CONFIDENCE IN AN ALL-SNOW OVER-RUNNING EVENT. UNCERTAIN AS TO
AMOUNTS AND IMPACTS...BUT WOULD PLACE THE GREATEST CONFIDENCE ALONG
THE S/SE-COASTLINE WITH RESPECT TO IMPACTS. SHOULD MATURATION OCCUR
WELL TO THE E THEN SNOW SHOULD REMAIN GENERALLY ON THE LIGHTER-SIDE
WITH ADVISORY-LEVEL ACCUMULATIONS. THINKING 15:1 TO 20:1 SNOW-TO-
LIQUID RATIOS S TO N. SOME BLOWING AND DRIFTING IS POSSIBLE PENDING
THE PROXIMITY OF THE OFFSHORE LOW TO S NEW ENGLAND. DETAILS SHOULD
BECOME MORE SPECIFIC AS WE GET CLOSER TO THE EVENT. ALL IN DUE TIME.
WEDNESDAY INTO WEDNESDAY NIGHT...
CONTINUED ENSEMBLE-MEAN PREFERENCE. FROM A CONSENSUS OF FORECAST
GUIDANCE...MID- TO UPPER-LEVEL FEATURES SWEEPING ACROSS THE REGION
SEEMINGLY INVOKE A LOW OVER THE GREAT LAKES REGION TOWARDS AREAS OF
GREATER BAROCLINICITY OFFSHORE. SOMEWHAT CONCERNED. QUESTION WHETHER
THIS IS ANOTHER ONE-/TWO-PUNCH AS WE HAVE SEEN THIS SEASON. NEED TO
WATCH THIS FORECAST PERIOD CLOSELY AS ENERGY BECOMES BETTER SAMPLED
INTO PERIODS OF HIGHER FORECAST RESOLUTION. AM NOT SOLD ON ANYTHING
FOR THE TUESDAY-WEDNESDAY PERIOD AS THE INDIVIDUAL 50-MEMBERS OF THE
EC-ENSEMBLE EXHIBIT A CONSIDERABLE SPREAD.
THURSDAY ONWARD...
OF ONLY CERTAINTY IS THE EXPECTATION OF THE BROAD CYCLONIC PATTERN
PREVAILING ACROSS THE REGION THROUGH WHICH ADDITIONAL ENERGY ALOFT
YIELDS AREAS OF LOW PRESSURE AND ADVERSE WEATHER FOLLOWED BY SHOTS
OF COLD ARCTIC AIR. APPEARING AS IF THE SNOWY AND BELOW-NORMAL TEMP
PATTERN CONTINUES...NEVER ENDING. CPC 6-10/8-14 AND CIPS ANALOGS AT
192-HOURS OUT WOULD ALL AGREE THAT WE REMAIN IN THE FREEZER.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TONIGHT/...TODAY...MODERATE
CONFIDENCE...MAINLY DUE TO TIMING ISSUES WITH HEAVIER SNOWBANDS.
STORM INTENSIFYING RAPIDLY OFFSHORE. N WINDS GUSTING AROUND 40-50
KTS ACROSS MUCH OF INTERIOR SRN NEW ENGLAND WITH GUSTS AROUND
50-65 KTS ACROSS E AND SE COASTAL TERMINALS WHERE +SN/BLSN
EXPECTED. STRONGEST WINDS AROUND MIDDAY. CIGS WILL IMPROVE ACROSS
CENTRAL AND WESTERN AREAS TO VFR...BUT LOW LEVEL VSBYS REDUCED
WITH BLSN.
TONIGHT...MAINLY VFR CIGS ACROSS SOUTHERN NEW ENGLAND. MVFR CIGS
ACROSS OUTER CAPE COD. SOME QUESTION WITH VISIBILITY DUE TO BLSN.
EXPECTING A TREND TO VFR WITH DIMINISHING WIND.
KBOS TAF...MODERATE CONFIDENCE IN TAF.
KBDL TAF...MODERATE CONFIDENCE IN TAF.
OUTLOOK...MONDAY THROUGH THURSDAY...
MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.
BLUSTERY NW-WINDS EARLY UP AROUND 25-35 KTS LIKELY TO RESULT IN BLSN
WITH IFR-LIFR VSBYS. WINDS DIMINISH INTO EVENING. LOW-END VFR / MVFR
OCEAN-EFFECT CIGS MAY LINGER ACROSS THE CAPE / ISLANDS. INCREASING
MID- TO HIGH CLOUDS INTO TUESDAY.
TUESDAY INTO WEDNESDAY...LOW CONFIDENCE.
SNOW POSSIBLE PARENT WITH IFR-LIFR OUTCOMES. N/NW-WINDS PERHAPS
BLUSTERY.
THURSDAY...LOW CONFIDENCE.
VFR. NW-WINDS. LOW-END VFR / MVFR OCEAN-EFFECT CIGS LINGERING ACROSS
THE CAPE / ISLANDS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TONIGHT/...
THROUGH TONIGHT...MODERATE CONFIDENCE.
EXPECT WINDS TO EVENTUALLY BACK N-NE THIS MORNING AND RAPIDLY
INCREASE. EXPECT SUSTAINED WINDS UP TO 50-60 KT AND GUSTS UP TO
60-70 KT THROUGH TODAY...HIGHEST ACROSS THE EASTERN WATERS. SEAS
WILL BUILD UP TO AROUND 15 FT TONIGHT WILL BUILD UP TO AROUND 25
FT ACROSS THE EASTERN WATERS TODAY.
HEADLINES ON THE WATERS CONTINUED. CONSIDERED THE NEED FOR
FREEZING SPRAY ADVISORIES IN BOSTON HARBOR AND NARRAGANSETT BAY.
WHILE IT IS TOUGHER TO GENERATE FREEZING SPRAY WITH MUCH LOWER
SEAS AND REDUCED FETCH ON THOSE BODIES OF WATER...VESSEL SPEEDS
WILL BE CRUCIAL. EXPECTING REDUCED VISIBILITIES IN MODERATE TO
HEAVY SNOW.
OUTLOOK...MONDAY THROUGH THURSDAY...
MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.
BLUSTERY NW-WINDS EARLY UP AROUND 35-40 KTS RESULTING IN SEAS AROUND
10-14 FEET ON THE OUTER WATERS. MODERATE-HEAVY FREEZING SPRAY WITH
AN ARCTIC AIRMASS MOVING OVER THE WATERS. ACTIVITY DIMINISHING INTO
MONDAY EVENING WITH GALES DROPPING OFF TO SMALL-CRAFTS AS FREEZING
SPRAY WARNINGS CONVERT TO HEADLINES. MOST HEADLINES DROP OFF TUESDAY
MORNING WITH ONLY SMALL-CRAFTS HOLDING ON THE OUTER WATERS FOR SEAS.
TUESDAY INTO WEDNESDAY...LOW CONFIDENCE.
OFFSHORE STORM LIKELY. PROXIMITY TO S NEW ENGLAND UNCERTAIN. SNOW
POSSIBLE. N/NW-WINDS PERHAPS BLUSTERY POTENTIALLY TO GALE-FORCE.
INCREASING SEAS POSSIBLE.
THURSDAY...LOW CONFIDENCE.
IN WAKE OF THE STORM...BLUSTERY NW-WINDS POSSIBLY TO GALE-FORCE.
POTENTIAL FOR LINGERING SNOW. SEAS INCREASE. FREEZING SPRAY ISSUES.
&&
.TIDES/COASTAL FLOODING...
MINOR TO MODERATE COASTAL FLOODING AND AREAS OF SIGNIFICANT BEACH
EROSION ARE EXPECTED FOR THE SALISBURY TO CAPE ANN AND HULL TO
DENNIS REACHES OF COASTLINE. THE COASTAL FLOOD WARNING REMAINS IN
EFFECT FOR THOSE AREAS. MINOR COASTAL FLOODING IS STILL EXPECTED
ALONG A FEW PORTIONS OF SHORE BORDERING BOSTON HARBOR AND NANTUCKET
HARBOR...AND A COASTAL FLOOD ADVISORY REMAINS IN EFFECT THERE. THE
NORTH SHORE FROM GLOUCESTER TO LYNN TECHNICALLY FALLS UNDER THE
COASTAL FLOOD WARNING BUT THAT IS ONLY BECAUSE THE ZONE INCORPORATES
ALL OF THE ESSEX COUNTY COAST. WE ANTICIPATE NO WORSE THAN MINOR
COASTAL FLOODING FROM GLOUCESTER TO LYNN WITH THIS STORM.
WE HAVE ONLY MADE FAIRLY MINOR TWEAKS TO THE FORECAST STORM SURGE
AND WAVE HEIGHT FOR THE TIME OF THE HIGH TIDE THIS MORNING...730
AM TO 830 AM MOST LOCATIONS. THE LATEST POSITIONING/CONFIGURATION
OF THE LOW LEVEL JET WAS IMPETUS TO INCREASE THE STORM SURGE BY A
FEW TENTHS ALONG THE SCITUATE TO DENNIS REACH OF COASTLINE. THE
OVERALL PICTURE OF EXPECTED IMPACTS AND WARNINGS/ADVISORIES HAS
NOT CHANGED APPRECIABLY. AT THE TIME OF THIS MORNING/S HIGH
TIDE...WE ANTICIPATE A STORM SURGE OF 2 TO 2.5 FEET ALONG THE MA
EAST COAST AND WAVES 15 TO 20 FEET SEVERAL MILES OFF THE COAST.
THE SURGE AND SEAS WILL CONTINUE TO BUILD DURING THE OUTGOING TIDE
AND WILL PROBABLY CAUSE THE TIDE TO RECEDE MUCH SLOWER THAN NORMAL
AND MAY EVEN CREST AS MUCH AS A HALF HOUR AFTER THE TIME OF THE
SCHEDULED ASTRONOMICAL HIGH TIDE IN SOME LOCATIONS. ALONG THE CAPE
COD BAY SHORE FROM SANDWICH TO DENNIS...THE STORM SURGE MAY CREST
NEAR OR EVEN A LITTLER HIGHER THAN 3.5 FEET BUT SEVERAL HOURS AFTER
THE TIME OF THE ASTRONOMICAL HIGH TIDE.
THIS EVENING/S HIGH TIDE IS LOWER ASTRONOMICALLY...AND THE WIND
SHOULD HAVE BECOME OFFSHORE FOR MOST SHORELINES BY THAT TIME. THUS
WE ANTICIPATE AT THIS TIME LITTLE OR NO IMPACT FOR THIS HIGH TIDE.
&&
.CLIMATE...
PRESIDENTS DAY MONDAY WILL BE VERY COLD ALTHOUGH SOME OF THAT WILL
BE DUE TO THE WIND. SOME OF THE LOW MAXIMUM RECORDS MAY BE AT
RISK. HERE ARE THE COLD TEMPERATURE RECORDS FOR THAT DATE.
FEBRUARY 16 RECORD LOW
BOSTON ......-9 IN 1943 PROVIDENCE...-10 IN 1943 WORCESTER....
-24 IN 1943 HARTFORD ....-24 IN 1943
FEBRUARY 16 RECORD LOW MAXIMUM
BOSTON ......14 IN 1943 PROVIDENCE...16 LATEST IN 1943
WORCESTER....12 LATEST IN 1963 HARTFORD.....12 IN 2003
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WIND CHILL WARNING FROM 4 PM THIS AFTERNOON TO 8 AM EST MONDAY
FOR CTZ002>004.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR CTZ002-
003.
WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR CTZ004.
MA...WIND CHILL ADVISORY FROM 4 PM THIS AFTERNOON TO 11 AM EST
MONDAY FOR MAZ020>024.
BLIZZARD WARNING UNTIL 4 AM EST MONDAY FOR MAZ005-013-017-018-
020-021-023.
COASTAL FLOOD WARNING UNTIL 11 AM EST THIS MORNING FOR MAZ007-
019-022.
WIND CHILL WARNING FROM 4 PM THIS AFTERNOON TO 8 AM EST MONDAY
FOR MAZ005>007-010>019-026.
BLIZZARD WARNING UNTIL 7 AM EST MONDAY FOR MAZ006-007-014>016-
019-022-024.
COASTAL FLOOD ADVISORY UNTIL 11 AM EST THIS MORNING FOR MAZ015-
016-024.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR MAZ002-
003-008>011.
BLIZZARD WARNING UNTIL 7 PM EST THIS EVENING FOR MAZ004-012-
026.
WIND CHILL WARNING FROM 4 PM THIS AFTERNOON TO 11 AM EST
MONDAY FOR MAZ002>004-008-009.
RI...WIND CHILL ADVISORY FROM 4 PM THIS AFTERNOON TO 11 AM EST
MONDAY FOR RIZ006>008.
BLIZZARD WARNING UNTIL 4 AM EST MONDAY FOR RIZ006>008.
WIND CHILL WARNING FROM 4 PM THIS AFTERNOON TO 8 AM EST MONDAY
FOR RIZ001>004.
BLIZZARD WARNING UNTIL 7 PM EST THIS EVENING FOR RIZ001>005.
MARINE...HEAVY FREEZING SPRAY WARNING FROM 10 AM THIS MORNING TO 1 PM
EST MONDAY FOR ANZ231>235-237-250-251-254>256.
HURRICANE FORCE WIND WARNING FROM 7 AM THIS MORNING TO 7 PM
EST THIS EVENING FOR ANZ231-232-250-254-255.
STORM WARNING UNTIL 5 AM EST MONDAY FOR ANZ230-233>237-251-256.
&&
$$
SYNOPSIS...BELK/SIPPRELL
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...SIPPRELL
AVIATION...BELK/SIPPRELL
MARINE...BELK/SIPPRELL
TIDES/COASTAL FLOODING...STAFF
CLIMATE...STAFF
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1126 PM EST SAT FEB 14 2015
.SYNOPSIS...
A POWERFUL OFFSHORE STORM WILL RAPIDLY DEVELOP TONIGHT THROUGH
SUNDAY. THERE WILL BE A PERIOD OF BLIZZARD CONDITIONS ACROSS
COASTAL COMMUNITIES SUNDAY MORNING...ALONG WITH HURRICANE FORCE
WIND GUSTS ACROSS THE OUTER CAPE AND NANTUCKET. EXCEPTIONALLY
COLD AIR...THE COLDEST OF THE SEASON...FOLLOWS LATE SUNDAY INTO
TUESDAY MORNING. ANOTHER STORM SYSTEM IS EXPECTED BY MIDWEEK
FOLLOWED BY ANOTHER SURGE OF BITTER COLD.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
1125 PM UPDATE...
INTERESTING FORECAST FOR SURE THIS EVENING. THE PREVIOUSLY
EXPECTED LULL HAS FINALLY ARRIVED ACROSS MOST OF SOUTHERN NEW
ENGLAND. A LOT OF LIGHTNING STRIKES SEEN OFFSHORE OF THE MID
ATLANTIC COAST...BUT IT IS QUITE CLOSE TO THE EDGE OF THE
DETECTION NETWORK. THE MAIN POINT WITH THIS IS THERE IS AN
ABUNDANCE OF POTENTIAL ENERGY TO BE TAPPED. WE ARE NOT YET DONE
WITH THIS STORM.
15/00Z SOUNDINGS ARE IMPRESSIVE. AS FAR WEST AS PITTSBURGH AND
CINCINNATI...NEAR DRY ADIABATIC LAPSE THROUGH A VERY DEEP LAYER.
ALSO SEEING SIGNS OF A TROPOPAUSE FOLD...WITH THE BASE OF THE
TROPOPAUSE AS LOW AS 700 MB OR SO. WE HAVE CONCERNS THE OFFSHORE
STORM WILL INTENSIFY EVEN MORE EXPLOSIVELY THAN PREVIOUSLY THOUGHT
LATE TONIGHT INTO SUNDAY.
LATEST RUNS OF THE HI-RESOLUTION GUIDANCE TRYING TO BEAR THIS OUT.
SOME...LIKE THE HRRR AND REGIONAL CANADIAN...SHOWING AN IMPRESSIVE
BANDING SIGNATURE. AT THIS POINT...HAVE LITTLE CONFIDENCE IN
EXACTLY WHERE THIS BAND WILL ESTABLISH ITSELF. WHERE IT DOES
PERSIST FOR A TIME...WILL LIKELY SEE LOCALLY HEAVIER SNOWFALL WITH
RATES OF 2-4 INCHES PER HOUR. THIS IS A COMPLICATING THE TOTAL
SNOWFALL FORECAST.
WITH THE POTENTIAL FOR BLOWING SNOW ONCE THE WINDS PICK
UP...GIVING SOME THOUGHT TO EXPANDING THE BLIZZARD WARNING FARTHER
WEST. WILL NEED A LITTLE MORE TIME TO EVALUATE THAT.
PREVIOUS DISCUSSION...
LOW PRES WILL TAKE SHAPE TONIGHT E OF THE NJ COAST...THEN RAPIDLY
INTENSIFY OVERNIGHT SE OF NANTUCKET OVERNIGHT AS STRONG H5 SHORT
WAVE RIDES INTO BASE OF DIGGING TROUGH...TRYING TO CUT OFF
OVERNIGHT AS THE TROUGH BEGINS TO BECOME NEGATIVELY TILTED.
NOTING THAT MOST SHORT RANGE MODELS DEVELOP THE INTENSIFYING LOW A
BIT FURTHER E THAN PREVIOUS RUNS...BUT STILL DO EXPECT A PERIOD OF
VERY STRONG WINDS AS LOW LEVEL NE JET QUICKLY INCREASES TO 50-65 KT
FROM 1000 TO 900 HPA ACROSS THE GULF OF MAINE ALONG WITH LAPSE
RATES ON ORDER 8.5C-10C/KM. BIG QUESTION AT THIS POINT WILL BE HOW
CLOSE TO THE COAST THIS OCCURS...ALLOWING THESE STRONG WINDS TO
MIX DOWN. AS COMMA HEAD ROTATES AROUND THE DEEPENING LOW
OFFSHORE...WILL SEE N-NE WINDS ALSO QUICKLY INCREASE TOWARD
DAYBREAK.
NEXT QUESTION THAT CONTINUES IS WHETHER THERE WILL BE A BREAK IN
THE PRECIP SHIELD OVERNIGHT AS THE LOW TAKES SHAPE. MODELS HAVING
THEIR ISSUES WITH THE TIMING OF THIS FEATURE BUT ALL DO SHOW THIS
IN ONE FORM OR ANOTHER. EXPECT LIGHT SNOW TO CONTINUE EARLY
TONIGHT...WITH SOME POCKETS OF MODERATE SNOW. THEN...AS THE COMMA
HEAD DEVELOPS AROUND THE RAPIDLY INTENSIFYING LOW AFTER
MIDNIGHT...EXPECT WRAP AROUND PRECIP TO WORK INTO NE MA SOMETIME
AROUND 08Z...THEN WORK S-SW ACROSS CENTRAL AND EASTERN AREAS
TOWARD DAYBREAK.
USED A BLEND OF PREVIOUS FORECAST ALONG WITH GFS AND EC...PLUS
THEIR ENSEMBLES. LEANED AGAINST USING THE 12Z NAM AS THIS RUN
SEEMED TO HAVE PROBLEMS HANDLING THE DEEPENING OF THE LOW.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
EXPECT LOW TO ELONGATE W-E TO THE E OF CAPE COD...DEEPENING TO
AROUND 975-980 HPA DURING SUNDAY. SOME TIMING ISSUES BETWEEN THE
TWO OP MODELS USED...THE GFS AND ECMWF IN BRINGING THE WRAP AROUND
MOISTURE ACROSS CENTRAL AND EASTERN AREAS. LEANED TOWARD ENSEMBLES
WITH SOMEWHAT QUICKER TIMING THAN THE 12Z EC RUN...CLOSER TO THE
GFS. WILL ALSO SEE WINDS INCREASE QUICKLY SUNDAY MORNING.
AS THE WINDS PICK UP...WILL SEE AREAS OF BLOWING SNOW DEVELOP.
WILL LIKELY SEE GUSTS UP TO AT LEAST 50 MPH...POSSIBLY UP TO
HURRICANE FORCE ACROSS THE CAPE AND ISLANDS. WHAT WILL ALSO HELP
IN KEEPING WINDS BLOWING IS THE ARCTIC AIRMASS THAT WORKS IN AS
THE LOW DEPARTS SUNDAY AFTERNOON. SNOWFALL SHOULD DIMINISH FROM
W-E DURING THE AFTERNOON...BUT THE BLOWING SNOW COULD KEEP
LOWER VISIBILITIES.
WITH THE STRONG MAINLY ONSHORE WINDS /N-NE DIRECTION/...WILL SEE
PROBLEMS WITH THE SUNDAY MORNING HIGH TIDE ACROSS THE NORMAL
PROBLEMATIC AREAS OF CAPE ANN AND THE SOUTH SHORE TO THE CAPE COD
BAY SHORELINE. PLEASE SEE THE COASTAL FLOOD SECTION BELOW.
WITH THE LOW A BIT FURTHER OFFSHORE...DID LOWER THE SNOW AMOUNTS
JUST A TAD...WITH MAX OF 10-14 INCHES ACROSS NE MA...8-10 INCHES
OVER N CENTRAL AND REMAINDER OF E MA...THEN DOWN TO 4-6 INCHES
OVER THE CT VALLEY. WITH THE STRONG WINDS...THOUGH...WILL LIKELY
SEE BLIZZARD CONDITIONS AT TIMES MAINLY DURING SUNDAY MORNING.
BEST SHOT REMAINS ACROSS E MA.
FINALLY...AS THE ARCTIC AIR WORKS IN ON THE STRONG N-NW WINDS
LATER SUNDAY...WIND CHILL VALUES WILL DROP TO -10 TO -20 ACROSS
CENTRAL AND WESTERN AREAS WITH THE LOWEST VALUES ACROSS THE HIGHER
TERRAIN BY AROUND SUNSET. WIND CHILL WARNINGS REMAIN IN EFFECT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
* COLDEST AIR OF THE SEASON EARLY NEXT WEEK
* DANGEROUSLY COLD WIND CHILLS SUNDAY NIGHT AND MONDAY MORNING
* ANOTHER STORM POSSIBLE BY MIDWEEK BUT CONFIDENCE IS LOW
* ANOTHER SURGE OF BITTER COLD FOLLOWS FOR THE END OF NEXT WEEK
SUNDAY NIGHT INTO MONDAY NIGHT...
WIND CHILL WARNINGS CONTINUE INTO MONDAY MORNING.
INTENSE LOW PRES WILL BE MOVING INTO NOVA SCOTIA SUN NIGHT WITH
STRONG NW WINDS DRAGGING DOWN THE COLDEST AIR OF THE SEASON INTO
SNE. MAINLY DRY CONDITIONS AND MOSTLY CLEAR SKIES...BUT OCEAN
EFFECT CLOUDS WILL LINGER OVER THE CAPE/ISLANDS AND IT APPEARS
SOME SNOW SHOWERS WILL AFFECT THE OUTER CAPE GIVEN HOW EXTREME THE
INSTABILITY WILL BE OVER THE OCEAN AS ARCTIC AIR MOVES IN. ANY
ACCUM SUN NIGHT SHOULD BE LESS THAN AN INCH AS MIXING DEPTH IS
RATHER SHALLOW...MOSTLY BELOW 900 MB AND TRAJECTORY WILL BE NW
WHICH WILL KEEP BULK OF ACTIVITY OFFSHORE.
BLOWING SNOW WILL BE AN ISSUE FOR MOST OF SUNDAY NIGHT. STILL
EXPECTING WIND GUSTS UP TO 50 MPH IN THE EARLY EVENING IN THE
COASTAL PLAIN BEFORE WINDS GRADUALLY DIMINISH THROUGH THE NIGHT
BUT STILL GUSTING TO 25-35 MPH OVERNIGHT...AND UP TO 45 MPH OUTER
CAPE/ISLANDS. CONSIDERABLE BLOWING SNOW AND REDUCED VSBYS.
THE MAIN STORY FOR SUN NIGHT INTO MON MORNING WILL BE THE BITTER
COLD AND DANGEROUSLY COLD WIND CHILLS. TEMPS WILL LIKELY BE 25-30
DEGREES BELOW NORMAL. USED A BLEND OF MOS AND 2M TEMPS WHICH
SHOW MINS DROPPING TO ZERO TO 10 BELOW ACROSS MOST OF SNE AND 10
TO 15 BELOW OVER THE HIGHER ELEVATIONS. EXPECT WIND CHILLS 20 TO
30 BELOW ZERO IN THE COASTAL PLAIN AND 30 TO 40 BELOW OVER THE
HIGHER ELEVATIONS IN CENTRAL AND W MA. THIS IS DANGEROUS COLD AND
FROSTBITE ON EXPOSED FLESH CAN OCCUR QUICKLY.
GUSTY NW WINDS WILL CONTINUE MONDAY AND DESPITE SUNSHINE MAXES
WILL ONLY REACH THE SINGLE NUMBERS TO LOWER TEENS. WIND CHILLS
DURING THE AFTERNOON WILL ONLY RECOVER INTO THE SINGLE NUMBERS
BELOW ZERO...BUT COLDER OVER THE HIGHER ELEVATIONS.
FOR MON NIGHT WINDS WILL FINALLY DIMINISH AS SFC RIDGE BUILDS IN
FROM THE WEST...BUT ANOTHER BITTER COLD NIGHT WITH MINS ZERO TO 10
BELOW ACROSS MUCH OF SNE...EXCEPT SINGLE NUMBERS NEAR THE COAST.
WIND CHILLS WILL BE 5 TO 20 BELOW AND ADVISORIES WILL LIKELY BE
NEEDED.
TUE...HIGH CLOUDS WILL BE MOVING INTO THE REGION. LIGHT WINDS
EXPECTED WITH SFC RIDGING OVER THE REGION AND TEMPS MODERATE INTO
THE TEENS AND POSSIBLY LOWER 20S IN THE COASTAL PLAIN.
TUESDAY NIGHT INTO WEDNESDAY NIGHT...
CONFIDENCE REMAINS SOMEWHAT LOW FOR THE SOUTHERN STREAM SYSTEM
EMERGING OFF THE MID ATLC COAST AND TRACKING SOUTH OF NEW
ENGLAND. MODELS HAVE STRUGGLED WITH THE TRACK WITH POOR RUN TO
RUN CONSISTENCY. LATEST DETERMINISTIC GUIDANCE KEEPS TRACK WELL
SOUTH OF THE BENCHMARK WITH GFS ON THE NW PERIPHERY OF THE
GUIDANCE ENVELOPE. THE GEFS MEMBERS ARE MOSTLY CLUSTERED CLOSE TO
THE BENCHMARK WITH NORMAL TIMING DIFFERENCES...WHILE THERE IS
CONSIDERABLE SPREAD AMONG THE ECENS MEMBERS. THE SHORTWAVE ENERGY
RESPONSIBLE FOR THE STORM IS NOT REACHING THE WEST COAST UNTIL
SUNDAY SO CONFIDENCE IN A GIVEN SOLUTION REMAINS LOW.
WE ARE LEANING TOWARD A BLEND OF ENSEMBLE MEAN SOLUTIONS WHICH
HAVE SHOWN LESS VARIABILITY BUT STILL HAVE TO LEAVE ALL MODEL
SOLUTIONS ON THE TABLE UNTIL SOME CLUSTERING IN THE GUIDANCE
EMERGES.
A TRACK CLOSE TO THE BENCHMARK WOULD BRING A MODERATE SNOW EVENT
TO E NEW ENG...ALTHOUGH PROGRESSIVE NATURE OF THIS SYSTEM WOULD
LIKELY PRECLUDE A BIG HIT. A FURTHER OFFSHORE TRACK WOULD HAVE A
MINIMAL IMPACT.
THURSDAY INTO FRIDAY...
ANOTHER SURGE OF BITTER COLD AND DANGEROUSLY COLD WIND CHILLS
FOLLOW FOR THU INTO FRI WITH 850 MB TEMPS DROPPING TO -20 TO
-30C...WHICH IS 2-3 SD BELOW NORMAL. MORE SUBZERO MINS THU NIGHT
AND FRI NIGHT WITH MAXES IN THE TEENS.
SATURDAY...
LOTS OF UNCERTAINTY AT THIS TIME RANGE. MODERATING TEMPS
EXPECTED...BUT ECMWF BRINGS SOME OVERRUNNING SNOW INTO SNE WHILE
GFS IS DRY.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SUNDAY/...
TONIGHT...MODERATE CONFIDENCE.
BRIEF LULL IN THE SNOWFALL THIS EVENING. EXPECTING SNOW TO RESUME
AFTER 06Z...AND RAPIDLY INTENSIFY LATE TONIGHT. WINDS BECOME N-NE
AND BEGIN TO INCREASE MAINLY ALONG THE E COAST...SUSTAINED AT
20-30 KT WITH GUSTS UP TO 35-45 KT. EXPECTING LIFR-VLIFR
CIGS/VSBYS IN SN/+SN. BLSN DEVELOPS AROUND OR AFTER 10Z.
SUNDAY...MODERATE CONFIDENCE.
STORM INTENSIFYING RAPIDLY OFFSHORE. N WINDS GUSTING AROUND 40-50
KTS ACROSS MUCH OF INTERIOR S NEW ENGLAND WITH GUSTS AROUND 50-65
KTS ACROSS E AND SE COASTAL TERMINALS WHERE +SN/BLSN EXPECTED.
STRONGEST WINDS AROUND MIDDAY. CIGS WILL IMPROVE ACROSS CENTRAL
AND WESTERN AREAS TO VFR...BUT LOW LEVEL VSBYS REDUCED WITH BLSN.
KBOS TAF...MODERATE CONFIDENCE IN TAF.
KBDL TAF...MODERATE CONFIDENCE IN TAF.
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
SUNDAY NIGHT INTO MONDAY...HIGH CONFIDENCE. CONDITIONS IMPROVE
TO VFR...EXCEPT LINGERING MVFR OVER THE OUTER CAPE IN OCEAN EFFECT
CLOUDS AND SCT SNOW SHOWERS SUN NIGHT. NW WIND GUSTS TO 40-45 KT
IN THE EVENING...THEN GRADUALLY DIMINISHING DURING THE NIGHT. NW
GUSTS 25-35 KT MON...STRONGEST OUTER CAPE/ISLANDS.
TUESDAY...HIGH CONFIDENCE. VFR WITH LIGHT WINDS.
TUESDAY NIGHT INTO WEDNESDAY...LOW CONFIDENCE. CONDITIONS WILL
DEPEND ON HOW CLOSE A COASTAL STORM TRACKS TO SNE. POTENTIAL FOR
IFR SNOW AND STRONG WINDS LATE TUE NIGHT INTO WED...BUT LESS
IMPACT IF STORM TRACKS WELL OFFSHORE.
THURSDAY...MODERATE CONFIDENCE. VFR. GUSTY NW WINDS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SUNDAY/...
TONIGHT AND SUNDAY...MODERATE CONFIDENCE.
EXPECT WINDS TO EVENTUALLY BACK N-NE OVERNIGHT AND RAPIDLY
INCREASE. EXPECT SUSTAINED WINDS UP TO 50-60 KT AND GUSTS UP TO
60-70 KT LATE TONIGHT THROUGH SUNDAY...HIGHEST ACROSS THE EASTERN
WATERS. SEAS WILL BUILD UP TO AROUND 15 FT TONIGHT WILL BUILD UP
TO AROUND 25 FT ACROSS THE EASTERN WATERS ON SUNDAY.
HEADLINES ON THE WATERS CONTINUED...EXCEPT TOOK DOWN THE HEAVY
FREEZING SPRAY WARNING FOR BOSTON HARBOR AND NARRAGANSETT BAY WITH
MUCH LOWER SEAS THERE. TOUGH TO GENERATE FREEZING SPRAY WITH LOW
SEAS AND MUCH LOWER FETCH. EXPECT REDUCED VSBYS IN MODERATE TO
HEAVY SNOW.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
SUNDAY NIGHT INTO MONDAY...MODERATE CONFIDENCE. MOSTLY GALE
FORCE NW WINDS...EXCEPT LINGERING STORM FORCE GUSTS OVER EASTERN
WATERS SUN EVENING. WINDS GRADUALLY DIMINISH THROUGH
MONDAY...POSSIBLY SUB GALE OVER NEARSHORE IN THE AFTERNOON AND
DROPPING BELOW SCA ALL WATERS BY LATE MON NIGHT. HEAVY FREEZING
SPRAY LIKELY SUN NIGHT INTO MON.
TUESDAY...HIGH CONFIDENCE. WINDS AND SEAS BELOW SCA AS HIGH PRES
BUILDS OVER THE WATERS.
WEDNESDAY...LOW CONFIDENCE. DEPENDING ON HOW CLOSE YET ANOTHER
STORM SYSTEM GETS TO THE SOUTHEASTERN WATERS...GALES OR SMALL
CRAFT ADVISORIES ARE LIKELY. A CLOSER TRACK WOULD SUGGEST GALES
WHILE A FURTHER SE TRACK WOULD SUGGEST SMALL CRAFT ADVISORIES.
WEDNESDAY NIGHT INTO THURSDAY...MODERATE CONFIDENCE. NW WIND
GUSTS APPROACHING GALE ARE LIKELY. MORE FREEZING SPRAY.
&&
.TIDES/COASTAL FLOODING...
MINOR TO MODERATE COASTAL FLOODING AND AREAS OF SIGNIFICANT BEACH
EROSION ARE EXPECTED FOR THE SALISBURY TO CAPE ANN AND HULL TO
DENNIS REACHES OF COASTLINE. THE COASTAL FLOOD WARNING REMAINS IN
EFFECT FOR THOSE AREAS. MINOR COASTAL FLOODING IS STILL EXPECTED
ALONG A FEW PORTIONS OF SHORE BORDERING BOSTON HARBOR AND NANTUCKET
HARBOR...AND A COASTAL FLOOD ADVISORY REMAINS IN EFFECT THERE. THE
NORTH SHORE FROM GLOUCESTER TO LYNN TECHNICALLY FALLS UNDER THE
COASTAL FLOOD WARNING BUT THAT IS ONLY BECAUSE THE ZONE INCORPORATES
ALL OF THE ESSEX COUNTY COAST. WE ANTICIPATE NO WORSE THAN MINOR
COASTAL FLOODING FROM GLOUCESTER TO LYNN WITH THIS STORM.
WE HAVE ONLY MADE FAIRLY MINOR TWEAKS TO THE FORECAST STORM SURGE
AND WAVE HEIGHT FOR THE TIME OF THE HIGH TIDE SUNDAY MORNING...730
AM TO 830 AM MOST LOCATIONS. BOTH THE ETSS AND ESTOFS STORM SURGE
GUIDANCE INCREASED SOME ON THE 1200 UTC RUN. THAT GUIDANCE AND THE
LATEST POSITIONING/CONFIGURATION OF THE LOW LEVEL JET WAS IMPETUS
TO INCREASE THE STORM SURGE BY A FEW TENTHS ALONG THE SCITUATE TO
DENNIS REACH OF COASTLINE. THE OVERALL PICTURE OF EXPECTED IMPACTS
AND WARNINGS/ADVISORIES HAS NOT CHANGED APPRECIABLY. AT THE TIME
OF THE SUNDAY MORNING HIGH TIDE...WE ANTICIPATE A STORM SURGE OF 2
TO 2.5 FEET ALONG THE MA EAST COAST AND WAVES 15 TO 20 FEET
SEVERAL MILES OFF THE COAST.
THE SURGE AND SEAS WILL CONTINUE TO BUILD DURING THE OUTGOING TIDE
AND WILL PROBABLY CAUSE THE TIDE TO RECEDE MUCH SLOWER THAN NORMAL
AND MAY EVEN CREST AS MUCH AS A HALF HOUR AFTER THE TIME OF THE
SCHEDULED ASTRONOMICAL HIGH TIDE IN SOME LOCATIONS. ALONG THE CAPE
COD BAY SHORE FROM SANDWICH TO DENNIS...THE STORM SURGE MAY CREST
NEAR OR EVEN A LITTLER HIGHER THAN 3.5 FEET BUT SEVERAL HOURS AFTER
THE TIME OF THE ASTRONOMICAL HIGH TIDE.
THE SUNDAY EVENING HIGH TIDE IS LOWER ASTRONOMICALLY...AND THE WIND
SHOULD HAVE BECOME OFFSHORE FOR MOST SHORELINES BY THAT TIME. THUS
WE ANTICIPATE AT THIS TIME LITTLE OR NO IMPACT FOR THE SUNDAY
EVENING HIGH TIDE.
&&
.CLIMATE...
PRESIDENTS DAY MONDAY WILL BE VERY COLD ALTHOUGH SOME OF THAT WILL
BE DUE TO THE WIND. SOME OF THE LOW MAXIMUM RECORDS MAY BE AT
RISK. HERE ARE THE COLD TEMPERATURE RECORDS FOR THAT DATE.
FEBRUARY 16 RECORD LOW
BOSTON ......-9 IN 1943 PROVIDENCE...-10 IN 1943 WORCESTER....
-24 IN 1943 HARTFORD ....-24 IN 1943
FEBRUARY 16 RECORD LOW MAXIMUM
BOSTON ......14 IN 1943 PROVIDENCE...16 LATEST IN 1943
WORCESTER....12 LATEST IN 1963 HARTFORD.....12 IN 2003
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WIND CHILL WARNING FROM 4 PM SUNDAY TO 8 AM EST MONDAY FOR
CTZ002>004.
WINTER STORM WARNING UNTIL 4 PM EST SUNDAY FOR CTZ002-003.
WINTER STORM WARNING UNTIL 7 PM EST SUNDAY FOR CTZ004.
MA...BLIZZARD WARNING UNTIL 4 AM EST MONDAY FOR MAZ005-013-017-018-
020-021-023.
COASTAL FLOOD WARNING FROM 6 AM TO 11 AM EST SUNDAY FOR MAZ007-
019-022.
WIND CHILL WARNING FROM 4 PM SUNDAY TO 8 AM EST MONDAY FOR
MAZ005>007-010>019-026.
BLIZZARD WARNING UNTIL 7 AM EST MONDAY FOR MAZ006-007-014>016-
019-022-024.
COASTAL FLOOD ADVISORY FROM 6 AM TO 11 AM EST SUNDAY FOR
MAZ015-016-024.
WINTER STORM WARNING UNTIL 4 PM EST SUNDAY FOR MAZ002-003-
008>011.
WINTER STORM WARNING UNTIL 7 PM EST SUNDAY FOR MAZ004-012-026.
WIND CHILL WARNING FROM 4 PM SUNDAY TO 11 AM EST MONDAY FOR
MAZ002>004-008-009.
RI...BLIZZARD WARNING UNTIL 4 AM EST MONDAY FOR RIZ006>008.
WIND CHILL WARNING FROM 4 PM SUNDAY TO 8 AM EST MONDAY FOR
RIZ001>004.
WINTER STORM WARNING UNTIL 7 PM EST SUNDAY FOR RIZ001>005.
MARINE...HEAVY FREEZING SPRAY WARNING FROM 10 AM SUNDAY TO 7 AM EST
MONDAY FOR ANZ231>235-237-250-251-254>256.
HURRICANE FORCE WIND WARNING FROM 7 AM TO 7 PM EST SUNDAY FOR
ANZ231-232-250-254-255.
STORM WARNING FROM 4 AM SUNDAY TO 5 AM EST MONDAY FOR ANZ230-
233>237-251-256.
&&
$$
SYNOPSIS...KJC/EVT
NEAR TERM...BELK/KJC/EVT
SHORT TERM...EVT
LONG TERM...KJC
AVIATION...BELK/KJC/EVT
MARINE...KJC/EVT
TIDES/COASTAL FLOODING...STAFF
CLIMATE...STAFF
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
420 AM EST SUN FEB 15 2015
.SYNOPSIS...SFC ANALYSIS SHOWS ARCTIC COLD FRONT LOCATED NEAR THE
ALTAMAHA RIVER MOVING STEADILY SWD. SW TO W FLOW AROUND 10 MPH AND
TEMPS ARE IN THE UPPER 40S AND LOWER 50S. POTENT MID TO UPPER LEVEL
TROUGH IS OVER THE MID ATLC AND NE STATES AND IS NOW OFFSHORE OVER
THE SE CONUS WITH SUBSIDENCE IN ITS WAKE. STRONG SFC HIGH PRES IS
LOCATED WELL TO OUR N NEAR THE GREAT LAKES AROUND 1044 MB...HELPING
TO PUSH THE SFC FRONT SWD THROUGH SE GA ATTM.
.SHORT TERM... TODAY...THE STRONG COLD FRONT WILL CONTINUE TO PUSH
SWD EARLY THIS MORNING AND MOVE INTO CENTRAL FL BY THE EARLY
AFTERNOON. SFC HIGH PRES WILL BUILD IN FROM THE N WITH WINDS
DECREASING AND TURNING TO NELY. COLD ADVECTION AND N-NE WINDS WILL
RESULT IN COOLER TEMPS TODAY...AROUND 50 N ZONES AND LOWER TO MID
60S S PORTIONS. JUST A NARROW BAND OF A FEW CLOUDS ACCOMPANY THE
FRONT AND HIGH CLOUDS CURRENTLY OVER THE NW GULF OF MEXICO AND TX
AREA WILL SLIDE EWD AS THE MID LEVEL TROUGH MOVES OUT AND ZONAL FLOW
ENSUES. OVERALL MOSTLY SUNNY WITH INCREASED HIGH CLOUDS IN THE AFTN.
TONIGHT...AS HIGH CLOUDS INCREASE THIS WILL HELP PUT A LID ON THE
COOLING TREND OVERNIGHT AND HAVE TWEAKED THE MIN TEMPS UP A BIT.
STILL LOOKS LIKE SOME FREEZING TEMPS POSSIBLE IN SE GA AND MID 30S
TO LOWER 40S IN NE FL. KEPT A MENTION OF PATCHY FROST IN THE FCST
GRIDS WITH AREAS OF FROST PREDICTED WHERE TEMPS ANTICIPATED TO BE
AROUND THE 30-34 DEG RANGE. PARTLY CLOUDY SKIES EXPECTED DUE TO THE
MID-UPPER LEVEL CLOUDS.
MONDAY...SKY COVER CONTINUES TO INCREASE AS STORM SYSTEM GATHERS
STRENGTH W OF THE AREA WITH MID LEVEL TROUGHING MOVING THROUGH THE
MS VALLEY. SFC LOW EXPECTED TO TRACK FROM ERN TX IN THE MORNING TO
TO AL BY LATE AFTN FORCING LOCAL LOW LEVEL FLOW TO TURN SE AND THEN
S LATER IN THE DAY. AS A RESULT WARM FRONT WILL PUSH THROUGH THE
AREA WITH TEMPS ABLE TO REACH WARM READINGS COMPARED TO THE PAST FEW
DAYS IN THE ZONES IN THE LOWER 70S...BUT EXPECT LOCATIONS N OF
WAYCROSS TO STAY IN THE LOWER TO MID 60S WHERE CLOUDS WILL BE
THICKEST. FAVORED SOMEWHAT COOLER MAX TEMPS THAN GUIDANCE DUE TO
CLOUDS. NOT MUCH CHANGE TO RAIN CHANCES WITH ISOLD TO SCT SHOWERS
PUSHING INTO OUR SE GA ZONES IN THE AFTN...WHILE A FEW SHOWERS ARE
POSSIBLE NEAR A WEAK SFC TROUGH OVER THE OFFSHORE COASTAL WATERS. MOS
POPS LOOKED A BIT OVERDONE OVER NE FL BUT CAN`T RULE OUT A FEW
SPRINKLES IN THE AFTN DUE TO WEAK CONVERGENT SE-S FLOW MAINLY NEAR
THE COAST.
MONDAY NIGHT THROUGH TUESDAY NIGHT...DETERMINING THE PRECIPITATION
TIMING AND RESULTANT POP GRADIENT IS THE MAIN CHALLENGE MONDAY
NIGHT. WE WILL SEE OVERCAST SKIES WITH RAIN STARTING TO SPREAD INTO
INLAND SE GA AS GULF LOW ENCROACHES THE REGION. CONFIDENT IN
SCATTERED TO NUMEROUS SHOWERS OVERSPREADING MUCH OF SE GA THROUGH
THE NIGHT WHILE NE FL WILL SEE MUCH LOWER RAINFALL CHANCES. POPS
MONDAY NIGHT WILL BE TAPERED WITH CATEGORICAL (75%) NW PART OF CWA
TO THE TEENS ACROSS THE SRN TIER. CLOUD COVER WILL KEEP LOWS NEAR 50
SE GA AND IN THE MID 50S NE FL. MODELS HAVE TRENDED NORTHWARD WITH
THE SURFACE LOW WITH THE EXCEPTION OF THE NAM. THE SURFACE LOW IS
FORECAST TO TRACK FROM CENTRAL ALABAMA QUICKLY NORTHEASTWARD
OFFSHORE OF THE MID ATLANTIC COAST BY DAYBREAK TUESDAY. THE
ATTENDING SFC FRONT WILL PUSH INTO SE GA LATE MONDAY NIGHT AND
MIGRATE THROUGH THE REGION AND PUSH THROUGH INTO NORTH CENTRAL FL BY
TUESDAY AFTERNOON. THE GFS / ECMWF WAY MORE PROGRESSIVE WITH THE
HANDLING OF THIS FRONT THAN EARLIER RUNS WITH ECMWF HANGING A LITTLE
LONGER WITH PRECIP FIELD TUESDAY EVENING NEAR THE IMMEDIATE COAST.
COLDER AIRMASS WILL PLUNGE INTO THE REGION LATE TUESDAY NIGHT AND
EARLY WEDNESDAY. LOWS WILL QUICKLY DROP INTO THE 30S ACROSS SE GA
AND SUWANNEE VALLEY AND LOWER/MIDDLE 40S AREAS EAST OF INTERSTATE 95
IN NE FL. MODELS ARE PUSHING MOISTURE OUT OF THE REGION JUST AHEAD
OF THE COLDER AIRMASS SO NO CHANGEOVER TO FROZEN PCPN EXPECTED AS IT
ENDS AS SOME OUTLIER MODELS ARE ATTEMPTING TO SHOW OVER NW PRECIPICE
OF INTERIOR SE GA.
.LONG TERM...
WED-FRI...UNSEASONABLY COLD HIGH PRESSURE AND AIRMASS WILL SETTLE
NORTH OF THE REGION AND EXPECT MAINLY SUNNY SKIES AND CHILLY DAYTIME
TEMPS IN THE 40S/50S WHILE SUB-FREEZING TEMPS ARE EXPECTED THU AND
FRI MORNINGS WITH FREEZES LIKELY OVER INLAND AREAS AND POSSIBLE HARD
FREEZES IN NORMALLY COLDER LOCATIONS. SOME HARD FREEZE PREPARATIONS
WILL LIKELY BE NEEDED BY OUR COMMUNITIES DURING THIS PERIOD.
SAT AND SUN...ZONAL FLOW ALOFT AND WARMING TREND IN STORE FOR NEXT
WEEKEND. LIGHT ONSHORE FLOW WILL COMMENCE BY LATE FRIDAY EVENING AND
SATURDAY. WINDS WILL VEER TO THE SOUTHWEST SUNDAY WITH INCREASING
CLOUDS AHEAD OF THE NEXT LOW PRESSURE SYSTEM DEVELOPING OVER THE
ARKLAMISS REGION WITH ISOLD TO WIDELY SCATTERED SHOWERS ACROSS SE GA
LATER IN THE DAY SUNDAY. TEMPS WARMING CLOSER TO SEASONABLE VALUES
IN THE 60S SATURDAY AND MOSTLY INTO THE 70S ON SUNDAY.
&&
.AVIATION...VFR PREVAILS. LLWS WAS INCLUDED EARLY THIS MORNING GIVEN
ABOUT 40 KT AT 1000 FT PER VWP AND RUC13 GUIDANCE. AS THE FRONT
MOVES SWD...WINDS ALOFT WILL WEAKEN AND SFC WINDS WILL INCREASE
ENDING LLWS MENTION IN THE TAFS. WINDS WILL SHIFT AROUND THE CLOCK
FROM WLY NOW TO NW AND N BY 12Z-14Z WITH SPEEDS AROUND 10-15G20KT
THEN BECOMING NELY AND DECREASING IN THE AFTN.
&&
.MARINE...STRONG WLY FLOW WILL TURN TO THE N BETWEEN 12Z AND 15Z
TODAY...AND SLOWLY WEAKEN THROUGH THE AFTN AS A SFC HIGH PRES CENTER
DEVELOPS NEAR THE SC/GA BORDER. SCA HEADLINES IN EFFECT AND MADE NOW
CHANGES TO THE TIMING. LATEST NWPS WAVE RUN SEEMED TO CAPTURE WAVE
HEIGHTS WELL WITH LITTLE ADJUSTMENT. WINDS BECOME NE AND E TONIGHT
AND THEN SLOWLY VEER AROUND TO THE SE DIRECTION BY LATE MONDAY
MORNING SPEEDS MAINLY UNDER 15KT. MONDAY AFTERNOON...SELY WINDS
INCREASE AHEAD OF THE APPROACHING FRONTAL SYSTEM AND SFC LOW WITH 15-
20 KT POSSIBLE OFFSHORE. SFC LOW TRACKS NEWD FROM SRN GA TUE WITH
FRONTAL PASSAGE TUESDAY WITH WINDS SHIFTING FROM SW TO NW. WITH THIS
EVENT...AN EXTENDED PERIOD OF SCA CONDS LOOKS TO START MON NIGHT AND
POSSIBLY CONTINUE THROUGH THU...ESPECIALLY FOR THE OFFSHORE WATERS.
RIP CURRENTS: LOW TO MODERATE RISK DUE TO LINGERING SWELLS AND THE
NNE FLOW BY THIS AFTERNOON.
&&
.FIRE WEATHER...THIS AFTERNOON EXPECT ELEVATED DISPERSIONS AND LOW
RELATIVE HUMIDITIES (20-30%) ACROSS SE GA AND SUWANNEE VALLEY WITH
FUEL MOISTURE LEVELS REMAINING TOO MOIST AND ABOVE CRITICAL LEVELS
TO KEEP ANY RED FLAGS FROM BEING NEEDED.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 50 32 61 50 / 0 0 20 70
SSI 47 37 58 52 / 0 0 10 50
JAX 54 36 66 54 / 0 0 10 30
SGJ 53 41 66 57 / 0 0 10 20
GNV 61 37 70 55 / 0 0 10 20
OCF 65 39 71 56 / 0 0 10 20
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR WATERS
FROM ALTAMAHA SOUND GA TO FERNANDINA BEACH FL FROM 20 TO 60
NM-WATERS FROM FERNANDINA BEACH TO ST. AUGUSTINE FL FROM 20
TO 60 NM-WATERS FROM ST. AUGUSTINE TO FLAGLER BEACH FL FROM
20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR COASTAL
WATERS FROM ALTAMAHA SOUND TO FERNANDINA BEACH FL OUT 20 NM-
COASTAL WATERS FROM FERNANDINA BEACH TO ST. AUGUSTINE FL
OUT 20 NM-COASTAL WATERS FROM ST. AUGUSTINE TO FLAGLER
BEACH FL OUT 20 NM.
&&
$$
SHASHY/CORDERO/
AREA FORECAST DISCUSSION
NWS GOODLAND KS
236 AM MST SUN FEB 15 2015
.SHORT TERM...(THIS AFTERNOON THROUGH SUNDAY)
ISSUED AT 153 PM MST SAT FEB 14 2015
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS 499 DM UPPER LOW
CENTERED OVER THE EASTERN GREAT LAKES REGION. NW FLOW IS IN PLACE
ACROSS THE PLAINS, WITH A SHORTWAVE TROUGH MOVING INTO THE
NORTHERN PLAINS FROM CANADA. AT THE SURFACE A COLD FRONT IS IN THE
PROCESS OF MOVING ACROSS OUR CWA...AND IS CURRENTLY WEST OF KGLD
NEAR THE COLORADO BORDER...EXTENDING SOUTH JUST EAST OF KDDC.
THIS FRONT WILL CONTINUE TO TRANSITION WESTWARD THROUGH THE LATE
AFTERNOON AND EVENING...BEFORE STALLING IN EASTERN COLORADO (WEST
OF OUR CWA). CAA WILL CONTINUE THROUGH THE OVERNIGHT PERIOD WITH
MUCH COLDER TEMPS CONTINUING THROUGH THE DAY SUNDAY. THERE MAY BE
A PERIOD OF RETURN FLOW AND CLEARING IN SKY COVER FROM THE
SOUTHWEST...WHERE HIGHS SUNDAY MAY WARM INTO THE 40S. LOW-MID
CLOUDS MAY HOLD ON ACROSS THE EAST WHERE TEMPS MAY STRUGGLE TO
WARM ABOVE FREEZING SUNDAY AFTERNOON. NAM/SREF/RAP/HRRR CONTINUE
TO SHOW BL MOISTURE POOLING ALONG FRONTAL ZONE IN EASTERN COLORADO
WHICH COULD SUPPORT ADDITIONAL STRATUS OR FOG DEVELOPMENT. WE MAY
BE WELL MIXED ENOUGH THAT SIGNIFICANT VIS RESTRICTIONS WOULD NOT
BE AN ISSUE...AND GUIDANCE CURRENTLY KEEPS VIS ABOVE 3SM. I LEFT
PATCHY FREEZING FOG MENTION IN THE WEST...BUT NOT A LOT OF
CONFIDENCE.
SHORTWAVE TROUGH MOVES OVER THE REGION WITH SECOND ROUND OF CAA
ARRIVING BY LATE AFTERNOON. MAIN AREA OF FORCING WILL BE ASSOCIATE
WITH LOBE OF VORTICITY/ELEVATED BAROCLINIC ZONE WHICH CURRENT
TIMING FAVORS LATE AFTERNOON IN THE NORTH. MADE ADJUSTMENTS TO
BLEND WITH EVENING PERIOD AND SHOW THIS TRANSITION. ANY PRECIP IN
THE AFTERNOON WILL LIKELY BE MORE OF A RAIN/SNOW MIX BASED ON TEMP
PROFILES/WBZ HEIGHTS.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 236 AM MST SUN FEB 15 2015
THIS EXTENDED FORECAST RUN IS UNFORTUNATELY PLAGUED BY ENSEMBLE
SPREAD AND SIZABLE DISAGREEMENT BETWEEN OPERATIONAL RUNS. THUS...
THESE PROBLEMS LEAD TO FORECASTER UNCERTAINTY ON UPPER LEVEL TROUGH
EVOLUTION BEYOND FRIDAY. HOWEVER...SOME CERTAINTIES CAN BE GLEANED
FROM GUIDANCE OUTPUT: 1. WE WILL WARM UP FOR THE MIDDLE/END OF NEXT
WEEK AND 2. WE LIKELY PLUNGE INTO ANOTHER COLD AIRMASS BY THE
WEEKEND. AS FOR PRECIPITATION CHANCES...MAJOR GUIDANCE DISCREPANCIES
NEED TO BE RESOLVED BEFORE WE CAN CONFIDENTLY DETERMINE WHAT WILL BE
RECEIVED.
BEGINNING WITH WEDNESDAY...A WARMING TREND ENSUES ACROSS THE REGION
AS THE PRIMARY...VIGOROUS EASTERN U.S. LONGWAVE TROUGH EDGES EAST.
THIS ALLOWS SOUTHWEST FLOW AND WARMING TEMPERATURES. AS WITH
YESTERDAYS LONG-TERM RUN...STILL NEED TO KEEP A CLOSE EYE ON WIND
SPEEDS. INTENSE 700 MB JET SHOULD BE SLOWLY EXITING THE REGION.
HOWEVER...UPWARDS OF 50 KTS REMAINS OVERHEAD AT 18Z. FORTUNATELY...
REMAIN UNDERWHELMED BY FORECAST SOUNDINGS...LAPSE RATES AND THUS
MIXING POTENTIAL. MOST LIKELY SCENARIO FOR LIGHT WINDS YESTERDAY
REMAINS THE LEAD SOLUTION THIS RUN. WARMER CONDITIONS ANTICIPATED
THURSDAY...HOWEVER...A SHORTWAVE TROUGH PUSHING IN FROM THE PACIFIC
NORTHWEST MAY THROW A WRENCH INTO THIS LIKELIHOOD AS INCREASING
CLOUD COVER WOULD BE EXPECTED.
FRIDAY AND BEYOND...FORECAST GUIDANCE LACKS CONSISTENCY AND VARIES
WILDLY IN SOLUTION. OPERATIONAL GFS AND EUROPEAN RUNS ARE COMPLETELY
OUT OF SYNC BY SUNDAY. THIS HAS MAJOR IMPLICATIONS TOWARDS WEATHER
WE WOULD OBSERVE. IF THE GFS IS RIGHT...THE REGION WOULD OBSERVE
OFF/ON PRECIPITATION...LIKELY SNOW...SATURDAY INTO MONDAY. EUROPEAN
SOLUTION SUGGESTS A FORECAST SIMILAR TO WHAT PREVIOUS TWO SYSTEMS
HAVE DONE FOR US...SOME LIGHT SNOW WITH MOST PRECIPITATION CONFINED
ALONG THE COLORADO FRONT RANGE. THE OPERATIONAL GFS DEVELOPS A LARGE
TROUGH OF LOW PRESSURE OVER THE WESTERN UNITED STATES THAT SLOWLY
PROGRESSES EAST MONDAY. MEANWHILE...THE EUROPEAN HAS A QUICK MOVING
NORTHWEST FLOW DISTURBANCE SATURDAY AND A DIGGING LONGWAVE TROUGH
CONFINED ALONG THE WEST COAST. FURTHER EXAMINATION OF GEFS ENSEMBLES
SUGGEST A LARGE AMOUNT OF SPREAD WITH MEMBERS SUPPORTING EITHER
SOLUTION OR DEPICTING A NEW ONE ONE ITS OWN. EITHER WAY...WE WILL BE
COOLER AS ANOTHER CANADIAN HIGH SLIDES SOUTH OVER THE PLAINS. WHAT
IS VERY UNCERTAIN IS TIMING OF PRECIPITATION CHANCES AND AMOUNTS.
OVERALL...MAINTAINED WHAT THE CR INITIALIZATION PROCEDURE PROVIDED.
FEEL MODEL UNCERTAINTY IS RESULT OF AN ANTICIPATED NORTHERN
HEMISPHERE UPPER LEVEL PATTERN CHANGE AND FUTURE FORECAST RUNS
SHOULD BEGIN TO HONE IN ON WHAT EXACTLY TO EXPECT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1000 PM MST SAT FEB 14 2015
KGLD...VFR CONDITIONS EXPECTED FROM TAF ISSUANCE THROUGH 22Z.
WINDS FROM THE SOUTHEAST AROUND 12KTS FROM TAF ISSUANCE THROUGH
17Z THEN SHIFTING TO THE NORTH AROUND 7KTS THROUGH 20Z AND 12KTS
FROM 21Z-22Z BEFORE DECREASING A BIT. MOSTLY MID CLOUDS EXPECTED.
MODEL RH X-SECTIONS SHOW A LAYER OF HIGH MOISTURE AROUND
2500-3000` SO HAVE KEPT A SCATTERED DECK AT THAT LEVEL. AFTER 23Z
A WEATHER DISTURBANCE APPROACHES FROM THE NORTH BRINGING MVFR CIGS
THROUGH THE REST OF THE TAF PERIOD. SOME LIGHT SNOW IS POSSIBLE
AFTER 03Z WITH REDUCED VISIBILITIES.
KMCK...VFR/MVFR CIGS EXPECTED FROM TAF ISSUANCE FOR A FEW/SEVERAL
HOURS WITH EAST OR EAST-SOUTHEAST WINDS AROUND 12KTS. BY 15Z WINDS
BECOME LIGHT/VARIABLE WITH VFR CONDITIONS. AROUND 21Z WIND SHIFT
MOVES THROUGH WITH NORTHWEST WINDS UNDER 10KTS AND LOWERING (BUT
REMAINING VFR) CIGS. AROUND 00Z LIGHT/VARIABLE WINDS MOVE IN WITH
VFR CONDITIONS CONTINUING THROUGH THE REST OF THE TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...RRH
AVIATION...99
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1000 PM MST SAT FEB 14 2015
.SHORT TERM...(THIS AFTERNOON THROUGH SUNDAY)
ISSUED AT 153 PM MST SAT FEB 14 2015
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS 499 DM UPPER LOW
CENTERED OVER THE EASTERN GREAT LAKES REGION. NW FLOW IS IN PLACE
ACROSS THE PLAINS, WITH A SHORTWAVE TROUGH MOVING INTO THE
NORTHERN PLAINS FROM CANADA. AT THE SURFACE A COLD FRONT IS IN THE
PROCESS OF MOVING ACROSS OUR CWA...AND IS CURRENTLY WEST OF KGLD
NEAR THE COLORADO BORDER...EXTENDING SOUTH JUST EAST OF KDDC.
THIS FRONT WILL CONTINUE TO TRANSITION WESTWARD THROUGH THE LATE
AFTERNOON AND EVENING...BEFORE STALLING IN EASTERN COLORADO (WEST
OF OUR CWA). CAA WILL CONTINUE THROUGH THE OVERNIGHT PERIOD WITH
MUCH COLDER TEMPS CONTINUING THROUGH THE DAY SUNDAY. THERE MAY BE
A PERIOD OF RETURN FLOW AND CLEARING IN SKY COVER FROM THE
SOUTHWEST...WHERE HIGHS SUNDAY MAY WARM INTO THE 40S. LOW-MID
CLOUDS MAY HOLD ON ACROSS THE EAST WHERE TEMPS MAY STRUGGLE TO
WARM ABOVE FREEZING SUNDAY AFTERNOON. NAM/SREF/RAP/HRRR CONTINUE
TO SHOW BL MOISTURE POOLING ALONG FRONTAL ZONE IN EASTERN COLORADO
WHICH COULD SUPPORT ADDITIONAL STRATUS OR FOG DEVELOPMENT. WE MAY
BE WELL MIXED ENOUGH THAT SIGNIFICANT VIS RESTRICTIONS WOULD NOT
BE AN ISSUE...AND GUIDANCE CURRENTLY KEEPS VIS ABOVE 3SM. I LEFT
PATCHY FREEZING FOG MENTION IN THE WEST...BUT NOT A LOT OF
CONFIDENCE.
SHORTWAVE TROUGH MOVES OVER THE REGION WITH SECOND ROUND OF CAA
ARRIVING BY LATE AFTERNOON. MAIN AREA OF FORCING WILL BE ASSOCIATE
WITH LOBE OF VORTICITY/ELEVATED BAROCLINIC ZONE WHICH CURRENT
TIMING FAVORS LATE AFTERNOON IN THE NORTH. MADE ADJUSTMENTS TO
BLEND WITH EVENING PERIOD AND SHOW THIS TRANSITION. ANY PRECIP IN
THE AFTERNOON WILL LIKELY BE MORE OF A RAIN/SNOW MIX BASED ON TEMP
PROFILES/WBZ HEIGHTS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 159 PM MST SAT FEB 14 2015
FOR THE EXTENDED PERIOD...THE H5 RIDGE WHICH HAD BEEN OVER THE
WESTERN HALF OF THE COUNTRY OVER THE PAST SEVERAL DAYS...WILL NOW
SHIFT FURTHER WEST FOR THE UPCOMING WEEK...MAINLY SETTING UP ALONG
THE WEST COAST. THIS IN TURN WILL ALLOW A BROAD...DEEP H5 LOW TO
ENCOMPASS ALMOST 2/3RDS OF THE COUNTRY. DURING THE COURSE OF THE
UPCOMING WEEK...THE TRI STATE REGION WILL SEE A COUPLE OF SHORTWAVES
MOVING ALONG THE BASE OF THE UPPER LOW...GIVING THE CWA A CHANCE FOR
SOME NEEDED PRECIPITATION.
FIRST SYSTEM WILL MOVE SOUTH THRU THE ROCKIES LATE SUNDAY NIGHT INTO
MONDAY NIGHT...FOLLOWED BY A WEAKER SECONDARY SYSTEM ON TUESDAY. A
STRONG SURFACE RIDGE WILL ACCOMPANY THE FIRST SHORTWAVE...EDGING
DOWN THE EAST SIDE OF THE ROCKIES IN TANDEM WITH THE SHORTWAVE. THIS
IS GOING TO PUT AN EASTERLY FETCH ACROSS THE AREA...WITH SOME
UPSLOPE POTENTIAL FOR WESTERN ZONES AS SYSTEM SLIDES THRU THE AREA.
WILL BE CONTINUING AS A RESULT THE SNOWFALL GRADIENT FROM PREVIOUS
FORECAST...WITH HIGHEST POTENTIAL OVER WESTERN ZONES...ESPECIALLY
FOR EASTERN COLORADO. MODEL DIFFERENCE IN AMT OF QPF POTENTIAL FOR
THIS SYSTEM. THINKING UPSLOPE/OROGRAPHIC EFFECTS WILL HAVE BEST
CHANCE FOR SNOW ACCUM IN AFOREMENTIONED AREAS AT 1-2" WITH 0.5-1"
FOR EASTERN ZONES. SECOND SHORTWAVE PASSES THRU CENTRAL KANSAS ON
TUESDAY WITH EASTERN ZONES IN CWA GETTING CLIPPED AS IT SWINGS THRU.
WILL GO WITH A SLIGHT CHANCE FOR -RW/-SW...WITH LITTLE TO NO ACCUM
EXPECTED.
DRY CONDITIONS EXPECTED TUESDAY NIGHT THRU THURSDAY NIGHT WITH HIGH
PRESSURE MAIN WEATHER FEATURE OVER THE CENTRAL PLAINS...AND LEE-SIDE
TROUGH FORMATION OVER THE EASTERN SIDE OF THE ROCKIES. GOING INTO
FRIDAY AND NEXT SATURDAY...GFS/ECMWF DO DIFFER ON TIMING(AS MUCH AS
12 HRS) OF NEXT SHORTWAVE TO DIG SOUTH THRU THE ROCKIES AND ACROSS
THE CENTRAL PLAINS. CONSENSUS IS TO KEEP SLIGHT CHANCE POPS IN FOR
NOW. TEMPS ARE WARM ENOUGH DURING THE DAYTIME HOURS TO SUPPORT RW
MIXING IN WITH -SW...BUT -SW AT NIGHT.
TEMPERATURES IN THE EXTENDED WILL NEAR NORMAL NUMBERS EARLY IN THE
FORECAST WITH THE ARRIVAL OF CAA WITH MONDAY SHORTWAVE...THEN
INCREASING TO ABOVE NORMAL AS RIDGE SETS UP TO EAST THRU
MIDWEEK...THEN BACK DOWN TO NEAR NORMAL BY END OF WEEK WITH ARRIVAL
OF NEXT SHORTWAVE. OVERALL HIGHS WILL MAINLY IN THE 40S WITH 50S
POSSIBLE FRIDAY...AND OVERNIGHT LOWS WILL MAINLY RANGE IN THE TEENS
WITH SOME L20S BY END OF WEEK TIMEFRAME. SOME WIND GUSTS COULD REACH
INTO THE 15-25MPH RANGE WITH GRADIENT BEHIND EACH SUBSEQUENT
SHORTWAVE PASSAGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1000 PM MST SAT FEB 14 2015
KGLD...VFR CONDITIONS EXPECTED FROM TAF ISSUANCE THROUGH 22Z.
WINDS FROM THE SOUTHEAST AROUND 12KTS FROM TAF ISSUANCE THROUGH
17Z THEN SHIFTING TO THE NORTH AROUND 7KTS THROUGH 20Z AND 12KTS
FROM 21Z-22Z BEFORE DECREASING A BIT. MOSTLY MID CLOUDS EXPECTED.
MODEL RH X-SECTIONS SHOW A LAYER OF HIGH MOISTURE AROUND
2500-3000` SO HAVE KEPT A SCATTERED DECK AT THAT LEVEL. AFTER 23Z
A WEATHER DISTURBANCE APPROACHES FROM THE NORTH BRINGING MVFR CIGS
THROUGH THE REST OF THE TAF PERIOD. SOME LIGHT SNOW IS POSSIBLE
AFTER 03Z WITH REDUCED VISIBILITIES.
KMCK...VFR/MVFR CIGS EXPECTED FROM TAF ISSUANCE FOR A FEW/SEVERAL
HOURS WITH EAST OR EAST-SOUTHEAST WINDS AROUND 12KTS. BY 15Z WINDS
BECOME LIGHT/VARIABLE WITH VFR CONDITIONS. AROUND 21Z WIND SHIFT
MOVES THROUGH WITH NORTHWEST WINDS UNDER 10KTS AND LOWERING (BUT
REMAINING VFR) CIGS. AROUND 00Z LIGHT/VARIABLE WINDS MOVE IN WITH
VFR CONDITIONS CONTINUING THROUGH THE REST OF THE TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JN
AVIATION...99
AREA FORECAST DISCUSSION
NWS CARIBOU ME
112 AM EST SUN FEB 15 2015
.SYNOPSIS...
A NOR`EASTER WILL RAPIDLY INTENSIFY ACROSS THE GULF OF MAINE
OVERNIGHT INTO SUNDAY...THEN SLOWLY EXIT ACROSS THE MARITIMES
SUNDAY NIGHT AND MONDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1250 AM UPDATE: LATEST RADAR LOOP SHOWED PRECIP SHIELD FURTHER E
W/AN ENHANCED BAND ACROSS SOUTHERN MAINE AND OFF THE COAST. THERE
WAS ANOTHER BAND SETTING UP ACROSS EASTERN MAINE FROM WASHINGTON
COUNTY NORTHWARD INTO SE AROOSTOOK COUNTY. SO FAR THE HIGHEST
SNOWFALL AMOUNTS HAVE BEEN DOWN ACROSS COASTAL AND EASTERN
WASHINGTON COUNTY W/UP TO 6 INCHES AND STILL SNOWING. THE 03Z RUNS
OF THE RAP AND NAM WERE HANDLING THINGS WELL AND NOW SHOWING A JOG
FURTHER E W/THE INTENSE BANDING. 06Z SURFACE ANALYSIS SHOWED
SOME NICE CONVERGENCE IN THE ENHANCED PRECIP AND LOW PRES
INTENSIFYING OFF OF CAPE COD AND MOVING ENE. THEREFORE,
ADJUSTMENTS WERE MADE TO THE QPF AND SNOWFALL AMOUNTS W/A SHIFT TO
THE E AND LOWERING THE AMOUNTS INCLUDING THE GREENVILLE AND BANGOR
REGIONS.
WE MIGHT BE ABLE TO DOWNGRADE THE WESTERN ZONES TO
WINTER WEATHER ADVISORIES. THE PLAN ATTM IS TO KEEP BLIZZARD
WARNINGS/WINTER STORM WARNINGS IN PLACE ACROSS THE EASTERN SIDE OF
THE REGION.
PREVIOUS DISCUSSION...
THE LOW WILL DEEPEN DRAMATICALLY THROUGH THE NIGHT. AS IT REACHES
THE GULF OF MAINE AND DRAWS A DEEP FLOW OF ATLANTIC MOISTURE
NORTHWARD...A POWERFUL BAND OF SNOW FEATURING SNOWFALL RATES OF 2
TO 4 INCHES AN HOUR WILL HIT THE DOWN EAST COAST EARLY SUNDAY
MORNING. THERE IS SOME INSTABILITY ALOFT THAT SUGGESTS THUNDER
SNOW IS POSSIBLE FOR THE DOWN EAST COAST SUNDAY MORNING. THIS
PUNCH HAS THE POTENTIAL TO PRODUCE A QUICK 12 TO 16 INCHES OF SNOW
IN WASHINGTON AND HANCOCK COUNTIES BY LATE SUNDAY MORNING WHERE
MAX OMEGAS WILL COINCIDE WITH STRONG DENDRITIC GROWTH. BY LATER
SUNDAY MORNING...THE BEST LIFT IS TRANSFERRING EASTWARD INTO THE
CANADIAN MARITIMES. HOWEVER...THE TROWAL REGION WILL REMAIN OVER
EASTERN MAINE AND ADVANCE NORTHWARD ACROSS THE FORECAST AREA WHILE
GRADUALLY WEAKENING. BANDING WITHIN THE DEFORMATION ZONE WILL
PRODUCE SOME AREAS OF HEAVIER SNOW THROUGH THE AFTERNOON. THE NET
RESULT IS THAT THE HIGHEST SNOWFALL TOTALS CONTINUE TO BE
ANTICIPATED AROUND WASHINGTON COUNTY WITH A MAXIMUM OF 2 FEET BY
MONDAY MORNING. ON THE OTHER HAND...THE STORM WILL BE FAR LESS
POTENT TOWARDS THE ALLAGASH AND SAINT JOHN VALLEY WHERE STORM
TOTALS MAY NOT HIT 7 INCHES...BUT HAVE LEFT WARNINGS IN PLACE DUE
TO THE IMPACT OF 50 MPH WIND GUSTS WITH THIS SNOW.
OVERALL...SNOW AMOUNTS WERE REDUCED SLIGHTLY TODAY WITH A MORE
EASTWARD STORM TRACK. THAT SAID...THE IMPACTS OF THIS STORM SHOULD
NOT BE DOWNPLAYED IN THIS FORECAST AREA. WIND FORECASTS HAVE NOT
CHANGED. GUSTS IN EXCESS OF 60 MPH CAN STILL BE EXPECTED WITHIN
MUCH OF THE BLIZZARD WARNING AREA. ELSEWHERE...GUSTS TO 50 MPH ARE
LIKELY. THE POWDERY NATURE OF THIS SNOW AND THESE WINDS WILL
CREATE SIGNIFICANT BLOWING AND DRIFTING. WHITEOUTS ARE PROBABLE.
WIND CHILLS WILL BE IN THE -10 TO -20F RANGE DURING THE STORM.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
VERY INTENSE LOW PRESSURE WILL BE LOCATED OVER NOVA SCOTIA SUNDAY
EVENING. AT THE SAME TIME STRONG HIGH PRESSURE WILL BE POSITIONED
OVER THE GREAT LAKES. THE JUXTAPOSITION OF THE TWO SYSTEM WILL
PRODUCE A STRONG PRESSURE GRADIENT AND GUSTY WINDS ACROSS THE
STATE AS THE LOW PULLS AWAY TO THE NORTHEAST ALONG WITH SNOW
BANDS. WINDS WILL CONTINUE TO CAUSE CONSIDERABLE DRIFTING OF THE
SNOW SUNDAY NIGHT. WINDS ARE THEN EXPECTED TO SLOWLY DECREASE
DURING THE DAY MONDAY. HIGH PRESSURE WILL CONTINUE TO APPROACH
FROM THE WEST MONDAY NIGHT AND CREST OVER THE STATE DURING THE DAY
TUESDAY. FOR POPS... QPF AND SKY WILL BLEND THE NAM... GFS AND
ECMWF. HAVE USED THE OFFICE SNOW FROM THICKNESS TOOL FOR SNOWFALL
AMOUNTS. THE NAM12 WAS USED FOR WIND SPEED. HAVE INITIALIZED THE
TEMPERATURE GRIDS WITH THE SUPER BLEND THEN LOWER NUMBERS A FEW
DEGREES DUE TO VERY COLD AIRMASS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE MAIN FOCUS FOR THE LONG TERM IS ANOTHER POTENTIAL COASTAL
EVENT FOR WED-THU TIME FRAME. THE 12Z OPERATIONAL MODELS HAVE
TRENDED FURTHER SOUTH AND EAST WITH THIS SYSTEM, WHICH WOULD KEEP
THE HEAVIEST SNOW ACROSS DOWNEAST (ONCE AGAIN). HOWEVER, IT SHOULD
BE NOTED THAT SEVERAL OF THE ENSEMBLE MEMBERS OF BOTH THE ECMWF
AND THE GFS TRACK THE LOW CENTER UP THROUGH THE BAY OF FUNDY, OR
EVEN ACROSS DOWNEAST MAINE ITSELF. THESE LATTER SOLUTIONS WOULD
SHIFT THE HEAVIER SNOW TO CENTRAL OR EVEN NORTHERN MAINE. WITH
CONFIDENCE BELOW NORMAL FOR HOW THIS WILL EXACTLY PLAY OUT, HAVE
STAYED CLOSE WITH A MODEL BLEND, WHICH IS CONSISTENT WITH THE
PREVIOUS FORECAST. ONCE THIS SYSTEM MOVES AWAY, COLD HIGH PRESSURE
WILL BUILD ACROSS THE EASTERN CONUS, WITH MAINLY DRY WEATHER
EXPECTED FOR THE END OF THE WEEK. TEMPERATURES WILL REMAIN WELL
BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: IFR CONDITIONS WILL CONTINUE THROUGH THE NIGHT FOR BHB
AND BGR AND DETERIORATE TO VLIFR VERY LATE TONIGHT THROUGH SUNDAY
MORNING. FROM HUL NORTHWARD...EXPECT VFR CONDITIONS TO GIVE WAY TO
MVFR CIGS WITH A PERIOD OF IFR VIS IN SNOW LATE THIS EVENING.
AFTER THIS PERIOD OF SNOW...CONDITIONS WILL BE VFR/MVFR UNTIL THE
SNOW ADVANCES NORTH INTO HUL BEFORE DAYBREAK SUNDAY AND EVENTUALLY
REACHES FVE TOWARDS LATE MORNING. ALL TERMINALS WILL BE HAVE
ISSUES WITH LLWS SUNDAY. WINDS AROUND FL040 TO FL050 ARE EXPECTED
TO BE AROUND 75 KTS. NORTHERLY SURFACE WIND GUSTS MAY HIT 60 MPH
AT BGR AND BHB. 50 MPH GUSTS ARE POSSIBLE FOR OTHER TERMINALS.
HEAVY SNOW AND THESE WINDS WILL MAKE RUNWAY CLEARING OPERATIONS
VERY DIFFICULT ON SUNDAY.
SHORT TERM: EXPECT IFR CONDITIONS MONDAY NIGHT THEN IMPROVING TO
VFR CONDITIONS MONDAY AND TUESDAY.
&&
.MARINE...
NEAR TERM: THE TIMING ON THE STORM LOOKS SIMILAR. HAVE INCREASED
MAXIMUM GUSTS TO 65 KTS. WINDS WILL INCREASE RAPIDLY ACCOMPANIED
BY HEAVY SNOW EARLY SUNDAY MORNING. SEAS WILL BUILD IN THE
AFTERNOON TOWARDS 15 TO 20 FEET. HEAVY FREEZING SPRAY STARTS FOR
THE INTRACOASTAL WATERS IN THE AFTERNOON AND SPREADS SOUTH AND
EAST BY LATE AFTERNOON.
SHORT TERM: FOR WINDS: HAVE USED THE NAM12. FOR WAVES: PRIMARY
WAVE SYSTEM SUNDAY NIGHT IS OFF-SHORE WIND WAVE WITH WAVE HEIGHTS
LIMITED BY FETCH DISTANCE FROM THE COAST. THIS WAVE GROUP IS
ACCOMPANIED BY A SECONDARY SOUTHEAST LONG PERIOD WAVE SYSTEM 5-6
FEET/12 SECONDS. THE LONG PERIOD WAVE GROUP IS EXPECTED TO SUBSIDE
SUNDAY NIGHT INTO MONDAY BUT STRONG OFF SHORE WIND WAVE WILL ONLY
SLOWLY SUBSIDE MONDAY INTO MONDAY NIGHT. ALSO EXPECT SIGNIFICANT
FREEZING SPRAY SUNDAY NIGHT INTO MONDAY. WILL USE NEAR SHORE WAVE
MODEL FOR WAVE GRIDS TO TAKE ADVANTAGE OF HIGHER RESOLUTION.
&&
.TIDES/COASTAL FLOODING...
A COASTAL HAZARD MESSAGE WAS ISSUED LATE THIS AFTERNOON FOR AROUND
THE TIME OF HIGH TIDE. PRIMARY CONCERN IS HIGH TIDE 0657 10.4
FEET SUNDAY MORNING AT BAR HARBOR. LATEST INDICATION IS THAT WIND
DIRECTION WILL TAKE A SLIGHTLY OFF-SHORE DIRECTION PRIOR TO HIGH
TIDE SUNDAY MORNING SO STORM SURGE NOT QUITE AS HIGH AS EXPECTED
24 HOURS AGO NOW EXPECT 1 TO 1.5 FOOT SURGE WHICH WOULD MAKE
MAXIMUM STORM TIDE LEVEL TO SLIGHTLY UNDER 12 FEET. AS WAS THE
CASE YESTERDAY WIND DIRECTION WILL KEEP LARGEST WAVES WELL OFF-
SHORE WITH WAVE HEIGHTS APPROACHING THE SURF ZONE AT TIME OF HIGH
TIDE AROUND 7 FEET. THERE IS ALSO A SECONDARY LONGER PERIOD WAVE
SYSTEM ARRIVING FROM THE SOUTHEAST AT TIME OF HIGH... HOWEVER WAVE
HEIGHTS WITH THIS WAVE GROUP STILL APPEAR TO BE LIMITED TO AROUND
5 FEET. SO WITH LIMITED WAVE HEIGHTS APPROACHING THE COAST ONLY
MINOR OVERTOPPING IS POSSIBLE IN SOME EXPOSED AREAS AT TIME OF
HIGH TIDE.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MEZ001>006-010.
BLIZZARD WARNING UNTIL 7 AM EST MONDAY FOR MEZ011-015>017-
029>032.
MARINE...HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 11 AM
EST MONDAY FOR ANZ050>052.
STORM WARNING FROM 4 AM EARLY THIS MORNING TO 7 AM EST MONDAY
FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1212 AM EST SUN FEB 15 2015
.SYNOPSIS...
AN ARCTIC FRONT HAS BROUGHT BITTERLY COLD TEMPERATURES TO THE
REGION TO START THE NEW WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
MIDNIGHT UPDATE WAS ISSUED TO EXPIRE THE WINTER WEATHER ADVISORY
OVER THE RIDGE ZONES AS SCATTERED SNOW SHOWERS AND FLURRIES ARE
ALL THAT REMAIN AS DRY ADVECTION AND SUBSIDENCE CONTINUE TO ERODE
THE POTENTIAL FOR FURTHER ACCUMULATION.
THE WIND CHILL WARNING REMAINS IN EFFECT ALTHOUGH ADJUSTMENTS
BASED ON THE LATEST OBS AND RAP GUIDANCE REQUIRE A DOWNWARD WIND
BUMP. READINGS REMAIN MARGINAL AT BEST OUTSIDE OF THE RIDGES...BUT
NO CHANGES FOR NOW.
DESPITE A GRADUAL WARMING IN TEMPERATURES ALOFT AFTER DAYBREAK...HIGHS
WILL LIKELY NOT MODERATE WELL AS W-NW FLOW CONTINUES. SURFACE HIGH
WILL CONTINUE TO BUILD EASTWARD DURING THE DAY SUNDAY...HELPING TO
SCATTER OUT CLOUDS AND DIMINISH WIND BY LATE IN THE DAY.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
ALREADY FRIGID TEMPERATURES WILL FURTHER PLUMMET AFTER NIGHTFALL
AS THE HIGH SHIFTS EASTWARD AND WIND CONTINUES TO DIMINISH. EXPECT
SUB ZERO READINGS ONCE AGAIN ON MONDAY MORNING...ALBEIT WITH
LIGHTER WIND...AND ONLY RELATIVE IMPROVEMENT THROUGH THE DAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE LONG TERM PERIOD REMAINS A LOW CONFIDENCE DEPICTION AS MODELS
CONTINUE TO PROG THE TUESDAY...WEDNESDAY SYSTEM TO OUR SOUTH.
MORE COLD AND OCCASIONAL CHANCES FOR SNOW SHOWERS CAN BE EXPECTED
AS SOLUTIONS INDICATE DEVELOPMENT OF A BROAD...HIGH AMPLITUDE
NORTH AMERICAN TROUGH BY MID TO LATE WEEK. WPC GUIDANCE CONTINUES
TO BE IN LINE WITH THESE TRENDS AND FEW ADJUSTMENTS WERE NEEDED
FOR THE LONG TERM FORECAST.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
COLD NORTHWEST FLOW ACROSS LAKE HURON IS EXPECTED TO BRING NARROW
BANDS OF MVFR TO LOW VFR STRATOCU THROUGH EARLY MORNING WITH LAKE
ERIE REMAINING FROZEN. SCATTERED TO OCCASIONALY BROKEN VFR STRATOCU...
WITH PATCHY MVFR...WILL REMAIN POSSIBLE SUNDAY. ANY REMAINING
SNOW SHOWERS SHOULD GRADUALLY DIMINISH OVERNIGHT AS MUCH DRIER AIR
MOVES IN AND SUBSIDENCE INCREASES. GUSTY NORTHWEST WINDS WILL
BEGING TO GRADUALLY DIMINISH LATER TODAY AS THE PRESSURE GRADIENT
DECREASES WITH BUILDING HIGH PRESSURE.
OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
A SERIES OF DISTURBANCES WILL BRING POSSIBLE PERIODIC RESTRICTIONS
MONDAY NIGHT THROUGH THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND CHILL WARNING UNTIL 10 AM EST MONDAY FOR MDZ001.
OH...WIND CHILL WARNING UNTIL 10 AM EST MONDAY FOR OHZ039>041-
048>050-057>059-068-069.
PA...WIND CHILL WARNING UNTIL 10 AM EST MONDAY FOR PAZ007>009-
013>016-020>023-029-031-073>076.
WV...WIND CHILL WARNING UNTIL 10 AM EST MONDAY FOR WVZ001>004-012-
021>023-041.
&&
$$
15/07
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1142 PM EST SAT FEB 14 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 330 PM EST SAT FEB 14 2015
DANGEROUS COLD IS IN STORE TONIGHT AND SUNDAY MORNING. WIND CHILLS
OF 20 TO 35 BELOW WILL RESULT IN FROSTBITE TIMES OF 15 MINUTES OR
LESS.
STRONG WINDS AND BLOWING SNOW WILL SUBSIDE THIS EVENING. HEAVY SNOW
SHOWERS NEAR LAKE MICHIGAN WILL END BY MIDNIGHT. WIND CHILLS WILL
RECOVER SUNDAY AFTERNOON WITH LIGHT WINDS AND BRIGHT SUNSHINE BUT
HIGH TEMPERATURES WILL BE ONLY IN THE SINGLE DIGITS.
TEMPERATURES WILL CONTINUE TO AVERAGE WELL BELOW FOR THE NEXT WEEK
OR MORE. ADDITIONAL PERIODS OF SNOW ARE LIKELY... HEAVY AT TIMES
NEAR LAKE MICHIGAN.
&&
.UPDATE...
ISSUED AT 936 PM EST SAT FEB 14 2015
WE HAVE EXTENDED THE WINTER STORM WARNING ALONG THE COASTLINE
UNTIL 4 AM SUNDAY MORNING. THE BAND OF LAKE EFFECT COMING INTO THE
LAKESHORE COUNTIES HAS BEEN SOMEWHAT STATIONARY OVER THE LAST
COUPLE OF HOURS. IT IS GOING TO TAKE A LITTLE LONGER THAN
PREVIOUSLY EXPECTED TO MOVE OFFSHORE. WINDS ARE COMING DOWN...BUT
VISIBILITIES ARE STILL QUITE LOW WITH SOME BLOWING SNOW STILL
LIKELY OCCURRING. ONCE THE BAND MOVES OFFSHORE...VISIBILITIES WILL
IMPROVE AND BLOWING AND DRIFTING SHOULD END.
UPDATE ISSUED AT 736 PM EST SAT FEB 14 2015
WE ARE ISSUING AN UPDATE EARLY THIS EVENING TO TRANSITION ALL
INLAND COUNTIES OVER TO A WIND CHILL WARNING. THE WINTER STORM
WARNING WILL CONTINUE FOR NOW UNTIL THE EXPIRATION TIME OF 10 PM
THIS EVENING...DEPENDING ON HOW FAST/SLOW THE LAST SNOW BANDS MOVE OFFSHORE.
THE MAIN HAZARD FOR INLAND AREAS HAS NOW TRANSITIONED TO THE
DANGEROUS WIND CHILLS EXPECTED TONIGHT AND TOMORROW MORNING. THE
SNOW SHOWERS HAVE COME TO AN END INLAND...AND WINDS HAVE
DIMINISHED ENOUGH TO ALLOW THE BLOWING AND DRIFTING TO DIMINISH.
WIND CHILLS CONTINUE TO LOOK LIKE THEY WILL APPROACH 30 BELOW AT
MOST INLAND LOCATIONS WITH A WIND REMAINING UP AND THE COLD ARCTIC
AIR STILL MOVING IN.
WE WILL LIKELY DO THE SAME THING FOR THE LAKESHORE COUNTIES ONCE
THE SNOW SHOWERS ARE PUSHED OFFSHORE BY THE DEVELOPING LAND BREEZE
COMPONENT. WE DO NOT WANT TO DO IT YET AS MANY COMMUNITIES/
COUNTIES ALONG THE LAKESHORE ARE HAVING TROUBLES WITH MANY ROADS
BEING DRIFTED SHUT STILL WITH THE FALLING SNOW AND BETTER WINDS THERE.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 330 PM EST SAT FEB 14 2015
ATTENTION SHIFTS FROM SNOW/BLOWING SNOW AND HIGH WINDS TO EXTREME
COLD TONIGHT. THE ONGOING HEADLINES WILL REMAIN IN EFFECT FOR A FEW
MORE HOURS TO COVER THE PERIODIC WHITEOUT/GROUND BLIZZARD SITUATION
THEN BECOME WIND CHILL HEADLINES.
WIND GUSTS ARE PEAKING NOW THROUGH ABOUT 5 PM BUT ARE EXPECTED TO
SHUT DOWN PRETTY QUICK THIS EVENING AS THE BOUNDARY LAYER DECOUPLES
SHORTLY AFTER 7 PM. HOWEVER SUSTAINED WINDS DO STAY UP MUCH OF THE
NIGHT WITH SPEEDS OF 10 TO 20 MPH. GUIDANCE HAS BEEN CONSISTENT
SHOWING AIR TEMPS FALLING TO 5 TO 15 BELOW WHICH SUPPORTS MIN WIND
CHILLS REACHING 25 BELOW OR LOWER OVER MUCH OF THE AREA.
INLAND CLEARING/LAND BREEZE FORMATION THIS EVENING WILL ASSIST IN
SENDING LAKESHORE SNOWS OFFSHORE. LATEST HRRR HAS THE LAKE EFFECT
SNOW BANDS SHIFTING OFFSHORE OF MKG AROUND 7 PM...HOLLAND AROUND 8
PM... SOUTH HAVEN AROUND 10 PM... AND LUDINGTON AROUND MIDNIGHT.
SURFACE RIDGING BUILDS IN QUICKLY ON SUNDAY CAUSING WINDS TO LIGHTEN
UP CONSIDERABLY. THUS WIND CHILLS RECOVER SUBSTANTIALLY IN THE
AFTERNOON UNDER BRIGHT SKIES IN FRIGID ARCTIC AIR MASS.
HI RES MODELS BEYOND 24 HOURS INDICATE MESOLOW CIRCULATION WILL
DEVELOP OVER SRN OR CNTRL LAKE MICHIGAN WITHIN MID LAKE CONVERGENCE
BAND. THIS SEEMS REASONABLE GIVEN VERY COLD/CLEAR SYNOPTIC PATTERN
AND STRONG LAND BREEZE CIRCULATIONS ON ALL SIDES OF LK MI. THIS
FEATURE SHOULD EVENTUALLY COME ONSHORE NORTH OF HOLLAND LATE SUNDAY
NIGHT OR MONDAY MORNING AS SYNOPTIC FLOW TURNS SOUTHWESTERLY.
MID LAKE MESO FEATURES CAN PRODUCE EXCESSIVE SNOW RATES... SO THIS
WILL NEED TO BE CLOSELY WATCHED. ALSO DEEPER MOISTURE ARRIVES ABOUT
THE SAME THIS FEATURE COMES ONSHORE AND THE DGZ RETURNS BACK INTO
THE CLOUD LAYER DUE TO WARMING. ADVISORY/WARNING MAY BE NEEDED
MON/MON NGT FOR WEST CENTRAL LWR MI INCLUDING MKG/LDM AREAS.
POSSIBLY BIV/GRR AS WELL DEPENDING ON MEAN LOW LEVEL WIND DIRECTION.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 330 PM EST SAT FEB 14 2015
THE LONG RANGE FORECAST PERIOD CONTINUES TO LOOK VERY COLD AND
SNOWY. ANOTHER SURGE OF ARCTIC AIR WILL BEGIN TO ARRIVE LATE TUESDAY
THROUGH TUESDAY NIGHT BEHIND THE ARCTIC COLD FRONT. MAX TEMPS
WEDNESDAY THROUGH FRIDAY WILL STRUGGLE TO REACH THE UPPER SINGLE
DIGITS TO LOWER TEENS.
THE ARCTIC FRONT WILL BRING POTENTIAL FOR A ROUND OF SNOW SHOWERS
TUESDAY WITH LAKE EFFECT SNOW SHOWERS ANTICIPATED MID TO LATE WEEK.
SIGNIFICANT HEAVY LAKE EFFECT SNOW EVENTS ARE NOT ANTICIPATED BUT
SEVERAL INCHES OF VERY DRY FLUFFY SNOW ARE POSSIBLE THROUGH MID TO
LATE WEEK.
WIND CHILL VALUES WILL BE QUITE COLD AS WELL MID TO LATE WEEK. WIND
CHILL READINGS WEDNESDAY THROUGH FRIDAY MORNING COULD BE COLDER THAN
15 DEGREES BELOW ZERO... ESPECIALLY OVER THE INTERIOR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1142 PM EST SAT FEB 14 2015
THE DOMINANT SNOW BAND IS NOW STARTING TO MOVE OFF SHORE AS
EXPECTED...THERE IS ONE MORE SMALL BAND... CURRENTLY (0430Z) OVER
EASTERN OCEANA...MUSKEGON AND OTTAWA COUNTIES AND THAT TOO IS
SLOWLY MOVING WESTWARD. SO I PUT ONE HOUR OF TEMPO IFR SNOW IN MKG
FOR THAT BAND. AFTER THAT MKG TOO SHOULD START TO SEE SOME
CLEARING.
THE REST OF THE TAF SITES WILL BE CLEAR THROUGH SUNSET SUNDAY AND
THAT MAY EVEN LAST TILL MIDNIGHT. WINDS WILL BE LIGHT SUNDAY.
&&
.HYDROLOGY...
ISSUED AT 1115 AM EST SAT FEB 14 2015
THE CORE OF THE WINTER SEASONS COLDEST AIR WILL CONTINUE TO MOVE IN
THROUGH THE DAY TODAY INTO SUNDAY. TEMPERATURES WILL CONTINUE TO
TUMBLE.
THEREFORE...ICE HAS NOT BUDGED AND CONDITIONS ARE STABLE. THERE IS
IS LOW RISK THAT ANY MOVEMENT WILL OCCUR THROUGH NEXT WEEK AS THE
WARMEST HIGH TEMPERATURES IN THE NEXT SEVERAL DAYS ONLY REACH INTO
THE 20S. DAILY AVERAGE TEMPERATURES IN THE SINGLE DIGITS AND TEENS
WILL AID IN ADDITIONAL ICE FORMATION OR EXPANSION.
LIQUID CONTRIBUTION WILL REMAIN RATHER LOW DAY TO DAY. ADDITIONAL
ROUNDS OF SNOW ARE POSSIBLE THIS WEEK...ESPECIALLY ALONG THE LAKE
SHORE...BUT NOT MUCH MELTING WILL BE TAKING PLACE THROUGH THE PERIOD.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WARNING UNTIL 4 AM EST SUNDAY FOR MIZ037-043-050-
056-064-071.
WIND CHILL WARNING UNTIL NOON EST SUNDAY FOR MIZ038>040-044>046-
051-052-057>059-065>067-072>074.
LM...NONE.
&&
$$
UPDATE...NJJ
SYNOPSIS...MEADE
SHORT TERM...MEADE
LONG TERM...LAURENS
AVIATION...WDM
HYDROLOGY...JAM
AREA FORECAST DISCUSSION
NWS DULUTH MN
336 AM CST SUN FEB 15 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 336 AM CST SUN FEB 15 2015
AN ARCTIC HIGH PRESSURE DESCENDING INTO THE UPPER GREAT LAKES TODAY
WILL BE FOLLOWED BY A WEAK CLIPPER SYSTEM WHICH WILL BRING A CHANCE
FOR LIGHT SNOWFALL ACCUMULATIONS TODAY/TONIGHT. PRIMARY CONCERN FOR
THE SHORT TERM IS TIMING AND INTENSITY OF SNOWFALL AS A RESULT OF
THIS CLIPPER SYSTEM TODAY. ANOTHER CONCERN OF A MUCH SMALLER SPATIAL
SCALE IS CONVERGENCE OVER LAKE SUPERIOR RESULTING IN LAKE EFFECT
SNOW SHOWERS POSSIBLY AFFECTING THE NORTH AND/OR SOUTH SHORE NEAR
THE TWIN PORTS. TEMPERATURES WARM UP BRIEFLY MONDAY AS LOW/MID LEVEL
WINDS BECOME OUT OF THE SOUTHWEST LATE SUNDAY INTO MONDAY.
EARLY THIS MORNING...WEAK CONVERGENCE OVER LAKE SUPERIOR WEST OF A
LINE FROM SILVER BAY TO THE BAYFIELD PENINSULA POSSIBLY MAY LEAD TO
LAKE EFFECT SNOW SHOWER DEVELOPMENT. THIS IS EVIDENT ON RADAR AS
WEAK ECHOES AS WELL AS AN INTERMITTENT 2KFT CEILING DEVELOPING AT
SUPERIOR AIRPORT AND DULUTH SKY HARBOR. MOST SHORT-RANGE GUIDANCE IS
NOT PICKING UP ON THIS WITH THE EXCEPTION OF THE 00Z GEM-REGIONAL.
NO SURFACE REPORTS OF SNOWFALL AS OF 09Z /3 AM CST/ THIS
MORNING...WITH THE EXCEPTION OF ASHLAND WHERE FAVORABLE LAKE EFFECT
CONDITIONS HAVE EXISTED FOR A LONGER PERIOD OF TIME DUE TO A VERY
LIGHT BUT PERSISTENT NORTHEASTERLY WIND. WORKING AGAINST LAKE
EFFECT SNOW SHOWERS IS LESS THAN OPTIMAL MOISTURE AT LOW LEVELS AND
SOME WEAK DIRECTIONAL SHEAR AT LOW LEVELS PREVENTING A PERSISTENT
BAND FROM DEVELOPING. OPTED TO INCLUDE SOME ISO/SCT SNOW SHOWER
WORDING IN EARLY THIS MORNING...AND WILL CONTINUE TO MONITOR AND
UPDATE AS RADAR/OBS WARRANT. OTHERWISE...TEMPERATURES APPEAR ON
TRACK WITH PORTIONS OF BORDERLAND /SUCH AS INL/ NOT DIPPING AS LOW
AS ORIGINALLY EXPECTED DUE TO HIGH LEVEL CLOUD COVER.
TODAY...PRIMARY CONCERN IS A CLIPPER SYSTEM WHICH WILL BRING A BRIEF
PERIOD OF LIGHT SNOW SHOWERS. INCREASED POPS SLIGHTLY WHILE
ATTEMPTING TO CAPTURE THE FACT THAT INITIALLY THIS AFTERNOON THE
DURATION OF SNOWFALL WILL BE JUST A FEW HOURS. SNOW AMOUNTS WILL BE
A COATING TO AN INCH AT MOST...AND CURRENT SNOWFALL FORECAST MAY BE
ON THE HIGH SIDE...BUT AM COUNTING ON A HIGH SNOW RATIO /AROUND 20
TO 1/ SIMILAR TO FRIDAY MORNING IN THE TWIN PORTS AREA. A LITTLE
CONCERNED THAT THE HRRR/HIRES ARW ARE DIMINISHING THE LARGE-SCALE
LIFT AS THE CLIPPER MOVES TOWARDS THE WESTERN EDGE OF THE CWA THIS
MORNING...BUT 00Z AND 06Z NAM/NAM 4KM CONUS NEST/HIRES NMM AND
LATEST FEW RUNS OF RAP ARE MORE SUPPORTIVE OF CURRENT FORECAST. LOW
LEVEL LAPSE RATES WILL SUPPORT MIXING TO AROUND 900MB AT TIMES THIS
AFTERNOON...AND WHILE LOW LEVEL WINDS ARE NOT VERY STRONG COULD SEE
A FEW GUSTS IN THE 15-20KT RANGE DURING AND FOLLOWING SNOW SHOWERS
TODAY. TEMPERATURES RISING TO THE SINGLE DIGITS ABOVE ZERO IN MOST
LOCATIONS.
TONIGHT...SNOW SHOWERS END IN MOST LOCATIONS AS WEAK MID-LEVEL
RIDGING DEVELOPS OVER SOUTHERN ONTARIO TOWARDS MORNING. FOLLOWING
THE MAIN CLIPPER A SECONDARY 925/850MB TROUGH WILL MOVE THROUGH
CENTRAL MINNESOTA AND NORTHWEST WISCONSIN...AND WITH LOW LEVEL
MOISTURE ALREADY IN PLACE COULD SEE FLURRIES/LIGHT SNOW DEVELOPING.
UNLIKE PREVIOUS FEW EVENTS THERE TEMPS THROUGH THE COLUMN WILL BE
EITHER WITHIN OR COLDER THAN THE DENDRITIC GROWTH ZONE...SO FREEZING
DRIZZLE WILL NOT BE A CONCERN. TEMPERATURES FALLING TO NEAR TO
SINGLE DIGITS BELOW ZERO...WITH USUAL COLD SPOTS IN THE ARROWHEAD
REGION OF MINNESOTA DROPPING INTO THE MID-TEENS BELOW ZERO. MOST
GUIDANCE IS COLDER FOR THE LOW TEMPS...BUT SINCE CLOUDS WILL REMAIN
IN PLACE ALL NIGHT AND LOW LEVEL WINDS HAVE A SOUTHERLY COMPONENT
DECIDED TO GO A BIT WARMER THAN MODEL CONSENSUS.
MONDAY....WINDS TURN OUT OF THE WEST/NORTHWEST AND PRESSURE GRADIENT
OVER MINNESOTA INCREASES AS YET ANOTHER ARCTIC HIGH PRESSURE
DESCENDS FROM THE CANADIAN PRAIRIE TOWARDS THE NORTHERN HIGH
PLAINS. WINDS MAY BECOME BREEZY IN THE AFTERNOON...GUSTING TO
AROUND 20KTS AT TIMES. A LOW/MID LEVEL CLOUD DECK WILL STICK
AROUND MOST OF THE DAY...AND STEEP LOW LEVEL LAPSE RATES COULD
LEAD TO A FEW SNOW SHOWERS OR FLURRIES THROUGHOUT THE DAY DESPITE
A LACK OF GREAT LARGE-SCALE LIFT /BUT ABSENCE OF OVERWHELMING
LARGE-SCALE SUBSIDENCE/. TEMPS WARMER...RISING TO THE LOW TO MID
TEENS...AND EVEN NEAR 20 ALONG THE INTERSTATE 35 CORRIDOR.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 336 AM CST SUN FEB 15 2015
AN UPPER LOW ANCHORED NEAR HUDSON BAY WILL REMAIN NEARLY STATIONARY
FROM MONDAY NIGHT THROUGH FRIDAY. AT THE SFC...THIS TRANSLATES INTO
ARCTIC HIGH PRESSURE DRIFTING OVER THE FORECAST AREA FROM MANITOBA
MONDAY NIGHT THROUGH THURSDAY. COLD...DRY AIR WILL BE LOCKED IN
PLACE DURING THIS TIME. A NW FLOW WILL BE OVER THE FORECAST AREA AS
WELL AS OVER LAKE SUPERIOR. LAKE EFFECT SNOW SHOWERS WILL OCCUR
REGULARLY OVER THE GOGEBIC RANGE OF NE ASHLAND AND NORTHERN IRON
COUNTIES MONDAY NIGHT THROUGH THURSDAY. SNOW AMOUNTS WILL BE LIMITED
HOWEVER AS THIS TYPE OF AIRMASS WILL INDUCE ICE FORMATION ON LAKE
SUPERIOR AND WILL LIMIT THE ACCUMULATION POTENTIAL.
REGARDLESS...WILL HAVE SOME POPS THROUGH THIS PERIOD...EVEN INTO
SOUTHERN ASHLAND AND IRON COUNTIES. EACH NIGHT WILL HAVE THE
CAPABILITY OF LOW WIND CHILL VALUES...BUT WILL SAVE THE HEADLINES
FOR A LATER TIME AS THE SFC WIND DECOUPLES EACH NIGHT. FRIDAY AND
FRIDAY NIGHT WILL BE AFFECTED BY A CLOSED LOW PUSHING A SFC LOW
THROUGH THE FORECAST AREA. SOME LIGHT ACCUMULATIONS ARE ANTICIPATED.
SATURDAY FINDS THE RETURN OF ARCTIC HIGH PRESSURE TO THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1138 PM CST SAT FEB 14 2015
GENERALLY VFR CONDITIONS THROUGH THE TAF PERIOD AT ALL TAF
SITES...WITH A PERIOD OF MVFR VISIBILITIES AND CEILINGS LATE
TOMORROW AFTERNOON AND INTO TOMORROW NIGHT AT SOME SITES. PRIMARY
CONCERN IS A WEAK CLIPPER SYSTEM THAT WILL MOVE THROUGH THE REGION
TOMORROW PRODUCING A BRIEF PERIOD OF SNOWFALL WHICH WILL LIKELY
LOWER VISIBILITY TO MVFR LEVELS AT TIMES...AND MAY LOWER CEILINGS TO
MVFR CEILINGS AT WORST. WHILE A VERY SHORT PERIOD OF IFR VISIBILITY
DUE TO INTENSE SNOWFALL CANNOT BE RULED OUT...ESPECIALLY AT INL AND
HIB WHERE SNOWFALL IS EXPECTED TO BE MOST INTENSE...DO NOT HAVE
ENOUGH CONFIDENCE IN SPECIFIC TIMING AT THIS POINT. BEST TIMING FOR
THE INTENSE SNOWFALL WILL BE LATE MORNING AT INL/HIB/BRD...IN THE
17Z TO 19Z TIMEFRAME...LATE AFTERNOON /21Z-00Z/ AT DLH...AND EARLY
EVENING /00Z-03Z/ AT HYR.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 5 0 16 -9 / 80 40 10 0
INL 6 -12 10 -17 / 60 10 10 0
BRD 9 4 16 -7 / 80 20 10 0
HYR 6 1 15 -6 / 30 30 20 0
ASX 6 1 15 -3 / 40 30 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...JJM
LONG TERM...GSF
AVIATION...JJM
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1056 PM CST Sat Feb 14 2015
.UPDATE...
Issued at 954 PM CST SAT FEB 14 2015
Have backed off on introducing snow into the fcst. The nearly arid
airmass is too dry to overcome and it will take awhile to top-down
saturate. So will remove any mention of PoPs overnight and only
mention slight chance PoPs for Sunday morning. 00z NAM/GFs, LSX local
WRF, RAP and HRRR generate no measurable precipitation. Since it
would take significant upward vertical motion and rapid saturation to
overcome this very dry airmass this seems like a reasonable
expectation.
But things look like they will get very interesting from mid Sunday
afternoon through evening. Models are generating moisture further
north within a region of increasing layered frontogenesis. There is
also some isentropic ascent being generated at h7 with one or two
vorticity bands coinciding with the frontogenesis. Not enough time to
chew through all of the new data in time to make significant changes
to the forecast and the need to collaborate with adjacent offices.
Also don`t want to paint the mid shift into a corner but suspect they
will be considering adjusting the region of accumulating snow.
&&
.SHORT TERM...(This Evening through Tuesday Afternoon)
Issued at 223 PM CST SAT FEB 14 2015
Models continue to struggle with the clipper system digging through
the Rockies and merging with richer moisture south of the area. The
GFS, NAM and SREF all have trended drier with the system, while the
GEM and the ECMWF have increased their QPF leading to greater snow
amounts. If anything has been consistent with forecast over the last
few days it`s that models have been extremely inconsistent both with
the track of the upper wave as well as placement and amount of QPF.
For all intents and purposes, this just doesn`t look like big storm
for our forecast area. First, the amount of dry air moving into the
region in the wake of the frontal passage will be tough to overcome.
Second, that dry gets reinforced as the surface high shifts to the
Great Lakes are and we maintain an easterly/northeasterly surface
fetch. It seems that the GEM and ECMWF are perhaps too broad in
their QPF fields given the intrusion of dry air, so have minimized
their input into the forecast. Third, the jet structure still looks
off for getting any significant precipitation for our area. It`s not
until further south and east the some jet enhancement comes into
play leading to greater precipitation amounts south and east of the
forecast area. Fourth, there seems to be a lack of any persistent
frontogenetic band until the enhanced jet dynamics come into play and
then even that is to our south. Fifth, the very strong dendritic
zone omega is gone, perhaps shifting a bit south. That was one the
main features that looked to potential overcome the significant
low-level dry air. About the only positive thing working for this
system is the weak ascent associated with it as the wave passes by.
As a result of the negatives with this system, have continued to
trend amounts downward. For most of the forecast area, this equates
to about dusting to perhaps half an inch. Amounts should increase
over the southern to southeastern zones but still be less than an
inch and half.
Precipitation looks to shift away from the forecast area Sunday
night, giving way to temperatures in the single digits and teens for
Monday morning. Temperatures may rebound to near freezing Monday
afternoon but limited mixing and the potential for lingering cloud
cover, inhibiting maximum insolation, should keep temperatures on
the cold side. Cold air looks to be reinforced late in the day
Tuesday with another cold front. This may also bring us another
round of light snow but for now will continue with just a flurry
mention as as upper-level support looks meager at best. Instead,
cyclonically curved flow and very cold air aloft look to be main
driver of any snow.
.LONG TERM...(Tuesday Evening through Saturday)
Issued at 223 PM CST SAT FEB 14 2015
Upper-level pattern to initially be dominated by broad northwest
flow as longwave troughing stretches from eastern Canada down into
the American Southeast. Despite the passage of several shortwave
troughs embedded in northwest flow...high pressure over the Tenn and
Lwr Miss Rvr Vlys will limit any moisture return into our area
through the latter stages of the work week. The end result will be
continued below normal and dry conditions...at least through Friday
anyway. Following this...upper pattern to become more zonal across the
Nation/s midsection as longwave ridging begins to build across the
American West. As this occurs...both the GFS and ECMWF 12Z solutions
suggest a southern stream storm system tracking east-northeast from
the southern Plains by the start of the weekend. For now...the GFS
has the furthest northward track of this storm system...while the
ECMWF is quite a bit further south. If the GFS solution were taken
verbatim...expect rain to begin overspreading the area Friday night
as warm air advection begins interacting with a preexisting warm
front over the Arkansas River Vly. Initial looks at this system
suggest P-type will mainly be in the form of rain /at least
initially/ as both GFS and ECMWF suggest 850 temps above 0C through
at least Saturday. For now...will maintain Slgt Chc pops through
the conclusion of the fcst.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday Night)
Issued at 1058 PM CST SAT FEB 14 2015
Expecting VFR conditions initially, with gradually deteriorating
conditions during the latter half of the forecast. Increasing chances
of winter weather affecting the terminal sites, though the main focus
remains to the southeast. Onset is expected to occur late in the
forecast with degraded visibilities and ceilings extending into the
subsequent period. Otherwise, increased winds will remain out of the
east, with periodic gusts up to 20kts in the overnight hours.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...MJ
SHORT TERM...CDB
LONG TERM...32
AVIATION...Welsh
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
141 AM CST SUN FEB 15 2015
.UPDATE...
ISSUED AT 141 AM CST SUN FEB 15 2015
RECEIVED A COUPLE HIGHER SNOWFALL REPORTS FROM THE DEVILS LAKE
BASIN. ITS HARD TO SAY EXACTLY HOW ACCURATE THESE ESTIMATED
REPORTS ARE...BUT THEY VARY FROM 5 TO 8 INCHES...WHICH IS LIKELY
TOO HIGH BUT STILL INDICATIVE OF SOMETHING. WILL ISSUE AN ADVISORY
FOR 3-6 INCHES OF SNOW FOR THE DEVILS LAKE BASIN. CURRENT RADAR
IMAGERY DOES NOT SUPPORT THE RAP AND HRRR IDEA FOR AN ADDITIONAL
1-3 INCHES THROUGH 12Z. HOWEVER...THE UPPER WAVE IS YET TO PASS
SO AT LEAST SOME LIGHT SNOW SHOULD CONTINUE. VERY HIGH SNOW RATIOS
LEADING TO HIGHER THAN EXPECTED SNOWFALL. WILL MONITOR OTHER
AREAS...BUT AT THIS TIME MOST GUIDANCE CONTINUES TO SUGGEST
FORCING TO WEAKEN AFTER 09Z...SO OTHER AREAS SHOULD ALONG AND WEST OF
THE VALLEY SHOULD BE WITHIN THE 1-3 INCH RANGE...WITH AREAS EAST
OF THE VALLEY LESS THAN AN INCH.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 251 PM CST SAT FEB 14 2015
MAIN FORECAST CHALLENGE WILL BE THE BAND OF LIGHT SNOW MOVING IN
LATER TONIGHT. MODELS SEEM TO BE SLOWER ON BRINGING IT INTO THE
AREA AS WELL AS LOWER ON EXPECTED SNOW AMOUNTS. AS OF MID
AFTERNOON A RIDGE AXIS EXTENDED DOWN THE WESTERN EDGE OF THE RED
RIVER VALLEY. TO THE EAST OF THIS WINDS HAVE BECOME LIGHT NORTH
AND TO THE WEST WINDS WERE LIGHT EAST-SE. THE SNOW BAND HAS MOVED
INTO WESTERN ND WITH LIGHT SNOW BEING REPORTED AT KISN/KDIK.
LATEST HIGH RES MODELS AND 18Z NAM12 DO NOT BRING ANY OF THIS INTO
OUR WESTERN FA UNTIL AROUND OR AFTER 03Z SUN. THEN THE MAIN WAVE
WILL TRACK ACROSS THE NORTHERN HALF OF THE FA. MODELS SHOW THE
BEST POTENTIAL FOR 1-2 INCHES ACROSS THE KDVL REGION BEFORE THESE
AMOUNTS DRY UP SOME MOVING EAST...TO MORE AN INCH OR LESS. THIS
MAKES SENSE WITH THE DRY LOW LAYER IN PLACE WITH SFC DEW POINTS IN
THE TEENS TO AROUND 20 BELOW ZERO. STILL SUNNY IN THE EAST WITH
CLOUDS WEST...SO THERE WILL BE MORE TEMP DROP THIS EVENING IN THE
EAST BEFORE TEMPS STEADY OR RISE A BIT LATE. THE LIGHT SNOW SHOULD
TAPER OFF THRU THE DAY SUNDAY. LOOKS TO STAY FAIRLY CLOUDY INTO
SUNDAY NIGHT WHICH WILL KEEP ANY WIND CHILL HEADLINES AT BAY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 251 PM CST SAT FEB 14 2015
THERE MAY BE SOME DECREASE IN CLOUDS MON NIGHT INTO EARLY TUE.
IF THIS HOLDS TRUE...WHEN COMBINED WITH STEADY NORTH WINDS IT MAY
RESULT IN COLD WINDS CHILLS AGAIN. COOL AND BLUSTERY DAY ON TAP
FOR TUE WITH SOME LIGHT SNOW CHANCES IN THE EAST.
TUESDAY NIGHT-SATURDAY...PERSISTENT NORTHWEST FLOW ALOFT WILL
CONTINUE OVER THE NORTHERN PLAINS THROUGH THE PERIOD...KEEPING TEMPS
BELOW AVERAGE. A DRY MID-WEEK PERIOD IS EXPECTED AS SFC RIDGING
SLIDES OVER THE REGION. TEMPS ON WEDNESDAY WILL STRUGGLE TO RISE
ABOVE 0...WITH PERHAPS SOME REBOUND IN TEMPS FOR LATE IN THE WORK WEEK.
THERE IS LOWER CONFIDENCE IN TIMING OF ANY EMBEDDED SHORTWAVE
TROUGHS AT THE END OF THE PERIOD...AFFECTING LIGHT PRECIP CHANCES
AND DAY-TO-DAY TEMP TRENDS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1138 PM CST SAT FEB 14 2015
-SN WILL CONTINUE TO SLOWLY SPREAD EAST ACROSS THE REGION THIS
FORECAST PERIOD. BEST CHANCES FOR MVFR/LOCALLY IFR CIGS/VSBY WILL
BE ACROSS THE DVL AND GFK AREAS OVERNIGHT. REMAINDER OF THE TAF
SITES SHOULD REMAIN MOSTLY VFR AS SNOW BAND BEGINS TO WEAKEN LATER
TONIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL 7 AM CST THIS MORNING FOR NDZ006-
007-014-015-024-026-054.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...GODON
LONG TERM...GODON/MAKOWSKI
AVIATION...VOELKER
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1136 PM CST SAT FEB 14 2015
.UPDATE...
SEE THE UPDATED AVIATION DISCUSSION BELOW.
ISSUED ANOTHER UPDATE TO FURTHER REDUCE POPS AND SNOW AMOUNTS IN
THE NEXT 6 HOURS. THE MAIN WAVE OF ENERGY WILL STILL INFLUENCE THE
REGION LATER TONIGHT INTO SUNDAY MORNING. STRONG WARM AIR
ADVECTION/ISENTROPIC LIFT ACROSS THE FAR NORTHEAST CWA COULD STILL
RESULT IN A HALF IN OF SNOW OR SO BETWEEN 6Z AND 12Z. WILL CONTINUE
TO MONITOR AND ADJUST ACCORDINGLY.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
WATCHING AN AREA OF RADAR RETURNS ACROSS THE CENTRAL
DAKOTAS...WITH OBS SHOWING SNOW ACROSS ND BUT YET TO SEE ANYTHING
OF SIGNIFICANCE ACROSS SD. WEB CAM AT LEMMON DOES APPEAR TO SHOW
LIGHT SNOW HAS BEGUN. STILL A DECENT AMOUNT OF DRY AIR TO OVERCOME
BASED ON RAP SOUNDINGS BUT IMAGINE MBG WILL BEGIN REPORTING -SN
BEFORE TOO LONG. HAVE SCALED BACK SNOW AMOUNTS JUST A BIT ACROSS
THE EASTERN CWA GIVEN THE MOISTENING OF THE ATMOSPHERE THAT WILL
HAVE TO TAKE PLACE FIRST. SHOULD STILL BE ABLE TO SEE AROUND AN
INCH FOR MOST PLACES ALONG AND EAST OF THE JAMES VALLEY. SYSTEM
LOOKS TO BE OUT OF HERE BY SUNDAY AFTERNOON WITH WARMER
TEMPERATURES MOVING BACK IN. ANOTHER COLD FRONT IN ON TRACK TO
SWEEP SOUTH ACROSS THE AREA MONDAY AFTERNOON...BRINGING ANOTHER
SHOT OF GUSTY NORTH WINDS AND COLD AIR TO THE REGION.
.LONG TERM...TUESDAY THROUGH SATURDAY
VERY GOOD AGREEMENT WITH THE MODELS IN THE LONG TERM WITH THE UPPER
LEVEL LONG WAVE PATTERN ALONG WITH THE SURFACE FEATURES. THE LONG
TERM LOOKS TO HAVE MAINLY BELOW TO MUCH BELOW NORMAL TEMPERATURES
THROUGH AT THE LEAST TUESDAY...WEDNESDAY AND THURSDAY. A LARGE UPPER
LEVEL LOW PRESSURE TROUGH ACROSS EASTERN CANADA AND THE EASTERN US
THROUGH MOST OF THE PERIOD WILL BRING PREVAILING FLOW FROM CANADA
AND THE ARCTIC. AT THE SURFACE...A COUPLE HIGH PRESSURE AREAS WILL
MOVE ACROSS THE REGION FROM THE NORTH. THERE WILL ALSO BE A FEW
WEAK UPPER LEVEL SHORT WAVE TROUGHS AND SURFACE COLD FRONTS MOVING
THROUGH BRINGING SOME CHANCES OF LIGHT SNOW/FLURRIES WITH THEM.
LEFT IT MAINLY DRY THROUGH THE LONG TERM AT THIS TIME. TEMPERATURES
MAY RISE CLOSER TO NORMAL TO SLIGHTLY ABOVE NORMAL OUT WEST BY
FRIDAY AND SATURDAY.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
WARM AIR ADVECTION AND FORCING ASSOCIATED WITH AN UPPER LEVEL
SHORTWAVE MOVING ACROSS NORTHERN NORTH DAKOTA WILL RESULT IN LIGHT
SNOW SHOWERS OVER THE KABR AND KATY TAF SITES THROUGH EARLY SUNDAY
MORNING. PERIODS OF MVFR CIGS AND VSBYS ARE POSSIBLE AS SNOW
SHOWERS MOVE ACROSS THE REGION. WHILE SNOW WILL REMAIN EAST THE OF
KMBG TAF SITE...MVFR CIGS WILL LIKELY MOVE OVER THIS REGION AS
WELL. LIGHT WEST NORTHWEST WINDS AND VFR CONDITIONS SHOULD RETURN
TO THE REGION SUNDAY AFTERNOON.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...SERR
SHORT TERM...TMT
LONG TERM...MOHR
AVIATION...SERR
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
241 AM PST SUN FEB 15 2015
.SYNOPSIS...
HIGH PRESSURE OVER CALIFORNIA WILL KEEP DRY CONDITIONS AND ABOVE
NORMAL TEMPERATURES ACROSS THE REGION THROUGH NEXT WEEK. PATCHY FOG
WILL ALSO BE POSSIBLE IN THE SAN JOAQUIN VALLEY EACH NIGHT INTO THE
MORNING HOURS.
&&
.DISCUSSION...PATCHY DENSE FOG WAS REPORTED IN MERCED AND MADERA
OVERNIGHT AS WELL AS JUST WEST OF HIGHWAY 99. THE HRRR INDICATES
VISIBILITY WILL BEGIN TO RAPIDLY IMPROVE AROUND 16Z...WITH CLEAR
SKIES BY THE MID MORNING HOURS.
UPPER LEVEL HIGH PRESSURE CONTINUES TO DOMINATE THE EASTERN
PACIFIC...EXTENDING NORTH INTO ALASKA. THIS WILL BRING ABOVE
NORMAL TEMPERATURES...DRY WEATHER...AND PATCHY LATE NIGHT AND
EARLY MORNING FOG. DAYTIME HIGH TEMPERATURES WILL GENERALLY RANGE
FROM THE LOW TO MID 70S THROUGH THE VALLEY...FOOTHILL...AND DESERT
LOCATIONS. THESE TEMPERATURES ARE AROUND 10 DEGREES ABOVE NORMAL
FOR THE MIDDLE OF FEBRUARY.
AN UPPER LEVEL SHORT WAVE WILL MOVE EAST TOWARD THE BRITISH
COLUMBIA COASTLINE ON WEDNESDAY AND BEGIN MOVING NEARLY DUE SOUTH
INTO THE GREAT BASIN FRIDAY INTO THE WEEKEND. THIS WILL RESULT IN
A COOLING TREND FOR THE REGION DURING THE SECOND HALF OF NEXT
WEEKEND GIVEN THE CONTINENTAL ORIGIN OF THE SHORT WAVE. BY
SUNDAY...DAYTIME HIGH TEMPERATURES WILL GENERALLY RANGE IN THE LOW
TO MID 60S...NEAR NORMAL VALUES FOR THIS TIME OF YEAR.
ADDITIONALLY...NCEPS GLOBAL ENSEMBLE MEAN FORECAST...AS WELL AS
THE OPERATIONAL FORECAST MODELS...ARE IN GOOD AGREEMENT ABOUT THE
INSIDE SLIDER IMPACTING THE AREA...BUT ARE ALL INDICATING
DIFFERENT IMPACTS FOR THE REGION. THE NAFES PROBABILITY OF
MEASUREABLE PRECIPITATION SHOWS AN INCREASE IN PROBABILITY OVER
THE SIERRA NEVADA IN THE PAST FEW RUNS. HOWEVER...GIVEN THE MAJOR
DIFFERENCES WITH ENSEMBLE MEAN FORECASTS FROM RUN TO RUN AS WELL
AS THE OPERATIONAL MODELS...WE HAVE LEFT OUT ANY CHANCE OF
PRECIPITATION. WE WILL CONTINUE TO MONITOR THIS WEATHER SITUATION
CLOSELY LEADING UP TO NEXT WEEKEND.
&&
.AVIATION...
IN THE SAN JOAQUIN VALLEY...PATCHY LIFR CIGS AND VIS AT KMCE AND
KMER AND DOWN CENTER OF THE VALLEY UNTIL 16Z SUNDAY. OTHERWISE...VFR
CONDITIONS WITH LIGHT AND VARIABLE WINDS ACROSS THE CENTRAL
CALIFORNIA INTERIOR.
&&
.AIR QUALITY ISSUES...
ON SUNDAY FEBRUARY 15 2015... FIREPLACE/WOOD STOVE BURNING STATUS
IS: NO BURNING UNLESS REGISTERED IN FRESNO... KERN... KINGS AND
TULARE COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.CLIMATE...
RECORDS
SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR
KFAT 02-15 79:1977 49:1990 58:1902 24:1990
KFAT 02-16 80:1943 48:1956 56:1957 27:1956
KFAT 02-17 84:1930 47:1890 57:1986 29:1956
KBFL 02-15 84:1977 50:1911 56:1982 21:1903
KBFL 02-16 88:1902 37:1919 55:1982 22:1903
KBFL 02-17 85:1930 44:1932 56:1968 24:1903
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...RILEY
AVN/FW...BEAN
SYNOPSIS...RILEY
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
613 AM EST SUN FEB 15 2015
.SYNOPSIS...
A POWERFUL OFFSHORE STORM WILL RAPIDLY DEVELOP TODAY. THERE WILL
BE A PERIOD OF BLIZZARD CONDITIONS THIS SUNDAY MORNING...
ESPECIALLY TOWARD THE COASTS...WITH HURRICANE FORCE WIND GUSTS
ACROSS THE OUTER CAPE AND NANTUCKET. EXCEPTIONALLY COLD AIR...THE
COLDEST OF THE SEASON...FOLLOWS LATE SUNDAY INTO TUESDAY MORNING.
ANOTHER STORM SYSTEM IS EXPECTED BY MIDWEEK FOLLOWED BY ANOTHER
SURGE OF BITTER COLD.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
610 AM UPDATE...
LATEST RUNS OF THE HRRR CONTINUE TO HAVE A GOOD HANDLE ON TIMING
AN INTENSE SNOW BAND ACROSS EASTERN MASSACHUSETTS. WILL LEAN
HEAVILY UPON ITS TIMING FOR THIS UPDATE.
REPORTS COMING IN OF THUNDERSNOW...WHICH IS ALSO SHOWING UP ON THE
NATIONAL LIGHTNING DETECTION NETWORK. WE CONTINUE TO RECEIVE
REPORTS OF 2-4 INCH/HOUR SNOWFALL RATES WITH THIS BAND.
FORTUNATELY...THIS BAND IS RATHER PROGRESSIVE...AND IS EXPECTED TO
MOVE PAST CAPE COD AND THE ISLANDS BY MID MORNING. WILL NEED TO
CONTINUE TO MONITOR THE PROGRESS OF THIS BAND. SHOULD IT STALL
OVER SOUTHEAST MA...WHICH IS A POSSIBILITY...THE SNOW COULD PILE
UP FAST.
PREVIOUS DISCUSSION...
15/00Z SOUNDINGS ARE IMPRESSIVE. AS FAR WEST AS PITTSBURGH AND
CINCINNATI...NEAR DRY ADIABATIC LAPSE THROUGH A VERY DEEP LAYER.
ALSO SEEING SIGNS OF A TROPOPAUSE FOLD...WITH THE BASE OF THE
TROPOPAUSE AS LOW AS 700 MB OR SO. WE HAVE CONCERNS THE OFFSHORE
STORM WILL INTENSIFY EVEN MORE EXPLOSIVELY THAN PREVIOUSLY THOUGHT
LATER TODAY.
LATEST RUNS OF THE HI-RESOLUTION GUIDANCE TRYING TO BEAR THIS OUT.
SOME...LIKE THE HRRR AND REGIONAL CANADIAN...SHOWING AN IMPRESSIVE
BANDING SIGNATURE. AT THIS POINT...WE CONTINUE TO HAVE LITTLE
CONFIDENCE IN EXACTLY WHERE THIS BAND WILL ESTABLISH ITSELF. WHERE
IT DOES PERSIST FOR A TIME...WILL LIKELY SEE LOCALLY HEAVIER
SNOWFALL...WITH RATES OF 2-4 INCHES PER HOUR. THIS IS A
COMPLICATING THE TOTAL SNOWFALL FORECAST.
AS OF 4 AM...WATCHING AN IMPRESSIVE SNOW BAND MOVING SOUTH ACROSS
EASTERN MASSACHUSETTS. WEBCAMS SHOWING SNOW IS RAPIDLY PILING UP
ACROSS ESSEX COUNTY. FORTUNATELY...THIS BAND DOES SEEM TO BE
PROGRESSIVE. 15/08Z HRRR SEEMS TO HAVE THE RIGHT IDEA...SO WILL
LEAN HEAVILY IN THAT DIRECTION FOR TIMING. WILL CONTINUE TO
MONITOR ITS PROGRESS. WE EXPECT SOME CHANGES TO OUR SNOWFALL
FORECAST AS WE GET MORE INFORMATION LATER THIS MORNING. MOST OF
THE SNOWFALL WILL BE DONE BY NOON. THE EXCEPTION SHOULD BE ACROSS
THE OUTER CAPE AND NANTUCKET WHERE OCEAN-EFFECT SNOW WILL LIKELY
PERSIST A BIT LONGER.
WITH THE POTENTIAL FOR BLOWING SNOW ONCE THE WINDS PICK UP...ONE
POSSIBLE DECIDED TO EXPAND THE BLIZZARD WARNING ONE MORE TIER
WEST EARLIER THIS MORNING.
DECIDED TO LEAVE THE WINTER STORM WARNING ALONG AND WEST OF THE CT
RIVER. THE LATEST REPORTS WE HAVE INDICATE SOLID ADVISORY LEVEL
EVENT SO FAR. THINKING THE BRUNT OF THE SNOWFALL WILL BE MAINLY
EAST OF THIS AREA TODAY...BUT CANNOT COMPLETELY RULE OUT HEAVIER
SNOW BANDS MAKING IT THAT FAR WEST. WILL CONTINUE TO REEVALUATE
THIS RISK LATER THIS MORNING.
WITH THE STRONG MAINLY ONSHORE WINDS /N-NE DIRECTION/...WILL SEE
PROBLEMS WITH THE SUNDAY MORNING HIGH TIDE ACROSS THE NORMAL
PROBLEMATIC AREAS OF CAPE ANN AND THE SOUTH SHORE TO THE CAPE COD
BAY SHORELINE. PLEASE SEE THE COASTAL FLOOD SECTION BELOW.
FINALLY...AS THE ARCTIC AIR WORKS IN ON THE STRONG N-NW WINDS
LATER SUNDAY...WIND CHILL VALUES WILL DROP TO -10 TO -20 ACROSS
CENTRAL AND WESTERN AREAS WITH THE LOWEST VALUES ACROSS THE HIGHER
TERRAIN BY AROUND SUNSET. WIND CHILL WARNINGS REMAIN IN EFFECT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
WIND CHILL WARNINGS CONTINUE INTO MONDAY MORNING.
INTENSE LOW PRES WILL BE MOVING INTO NOVA SCOTIA TONIGHT WITH
STRONG NW WINDS DRAGGING DOWN THE COLDEST AIR OF THE SEASON INTO
SOUTHERN NEW ENGLAND. MAINLY DRY CONDITIONS AND MOSTLY CLEAR
SKIES...BUT OCEAN-EFFECT CLOUDS WILL LINGER OVER THE CAPE/ISLANDS
AND IT APPEARS SOME SNOW SHOWERS WILL AFFECT THE OUTER CAPE GIVEN
HOW EXTREME THE INSTABILITY WILL BE OVER THE OCEAN AS ARCTIC AIR
MOVES IN. ANY SNOW ACCUMULATION TONIGHT SHOULD BE LESS THAN AN
INCH AS MIXING DEPTH IS RATHER SHALLOW...MOSTLY BELOW 900 MB AND
TRAJECTORY WILL BE NW...WHICH WILL KEEP THE MAJORITY OF SNOW
SHOWERS OFFSHORE.
BLOWING SNOW WILL BE AN ISSUE FOR MOST OF TONIGHT...ESPECIALLY
TOWARD THE COASTS STILL EXPECTING WIND GUSTS UP TO 50 MPH EARLY
THIS EVENING ACROSS THE COASTAL PLAIN. WINDS GRADUALLY DIMINISH
THROUGH THE NIGHT...BUT STILL GUSTING TO 25-35 MPH OVERNIGHT...
AND UP TO 45 MPH OUTER CAPE/ISLANDS. CONSIDERABLE BLOWING SNOW
WITH REDUCED VISIBILITY.
THE MAIN STORY FOR TONIGHT INTO MONDAY MORNING WILL BE THE BITTER
COLD AND DANGEROUSLY LOW WIND CHILLS. TEMPERATURES WILL LIKELY BE
25-30 DEGREES BELOW NORMAL. EXPECTING WIND CHILLS 20 TO 30 BELOW
ZERO ACROSS THE COASTAL PLAIN...AND 30 TO 40 BELOW OVER THE
HIGHER ELEVATIONS IN CENTRAL AND WESTERN MA. THIS IS DANGEROUS
COLD. FROSTBITE ON EXPOSED FLESH CAN OCCUR QUICKLY.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
*/ HIGHLIGHTS...
- POTENTIAL MIDWEEK STORM SYSTEM MAINLY IN THE FORM OF SNOW
- CONTINUED BITTERLY COLD
- NO BREAK IN THE WEATHER PATTERN
- NEXT CHANCE OF WARMTH: SOMETIME SPRING INTO SUMMER
*/ OVERVIEW...
ENSEMBLE-MEAN PREFERENCE FORECAST. POSITIVE TELECONNECTION PATTERNS.
BROADER CYCLONIC FLOW CONTINUES THROUGH WHICH WE WILL SEE ADDITIONAL
WEATHER SYSTEMS FOLLOWED BY SHOTS OF COLD ARCTIC AIR. IT APPEARS WE
WILL NOT SEE A BREAK IN A PATTERN OVER THE NEXT WEEK. THE MASSIVE
AMOUNTS OF SNOW WILL REMAIN TO REMIND US JUST HOW AWFUL WINTER HAS
BEEN AND HOW WONDERFUL IT CAN BE LIVING IN NEW ENGLAND. HAPPY DAYS
ARE HERE AGAIN!
*/ DAILIES...
MONDAY INTO MONDAY NIGHT...
VERY COLD AND DRY. INITIAL BLUSTERY NW-WINDS YIELDING EXCEPTIONALLY
COLD WIND CHILL VALUES OF 15 TO 25 DEGREES BELOW-ZERO INTO MIDDAY.
WIND CHILL HEADLINES CONTINUING. WINDS RELAXING WHILE HIGHS TOP OUT
INTO THE SINGLE-DIGITS TO LOW-TEENS INTO THE LATER-HALF OF THE DAY.
SAVING CAVEAT IS ABUNDANT SUNSHINE.
LIGHT WINDS OVERNIGHT WITH A RENEWED SNOWPACK BENEATH HIGH PRESSURE.
PRIOR TO INCREASING LOW- TO MID-LEVEL CLOUDS FROM THE S...ANTICIPATE
RADIATIONAL COOLING ACROSS INTERIOR NEW ENGLAND. LOWS DROPPING WELL-
BELOW ZERO WITH LIKELY DRAINAGE LOCATIONS LOWER THAN 10-BELOW. HAVE
CONFIDENCE IN SUCH OUTCOMES AROUND THE MERRIMACK RIVER VALLEY.
TUESDAY INTO TUESDAY NIGHT...
PREFER ENSEMBLE-MEANS AND A CONSENSUS FORECAST SPREAD. NO PREFERENCE
WITH CONTINUED MODEL SPREAD. DOES APPEAR TO BE A WEAK-WAVE IMPULSE
ALONG THE OFFSHORE BAROCLINIC-ZONE LOW THAT INVOKES AN INFLECTION
LOW THAT UNDERGOES MATURATION DOWNSTREAM AS THE UPPER-LEVEL PATTERN
MEETS THE SURFACE REFLECTION. MUCH GREATER TILT / SEPARATION WITHIN
THE VERTICAL PRESSURE PATTERN RATHER THAN A NEARLY-STACKED SETUP. NO
CLOSED LOW INDICATIONS. THIS HAS BEEN CONSISTENTLY ADVERTISED WITHIN
EC-ENS ALONG WITH A COLD SOLUTION. HOPEFULLY NO SURPRISES WITH LATER
FORECAST GUIDANCE.
SO CONFIDENCE IN AN ALL-SNOW OVER-RUNNING EVENT. UNCERTAIN AS TO
AMOUNTS AND IMPACTS...BUT WOULD PLACE THE GREATEST CONFIDENCE ALONG
THE S/SE-COASTLINE WITH RESPECT TO IMPACTS. SHOULD MATURATION OCCUR
WELL TO THE E THEN SNOW SHOULD REMAIN GENERALLY ON THE LIGHTER-SIDE
WITH ADVISORY-LEVEL ACCUMULATIONS. THINKING 15:1 TO 20:1 SNOW-TO-
LIQUID RATIOS S TO N. SOME BLOWING AND DRIFTING IS POSSIBLE PENDING
THE PROXIMITY OF THE OFFSHORE LOW TO S NEW ENGLAND. DETAILS SHOULD
BECOME MORE SPECIFIC AS WE GET CLOSER TO THE EVENT. ALL IN DUE TIME.
WEDNESDAY INTO WEDNESDAY NIGHT...
CONTINUED ENSEMBLE-MEAN PREFERENCE. FROM A CONSENSUS OF FORECAST
GUIDANCE...MID- TO UPPER-LEVEL FEATURES SWEEPING ACROSS THE REGION
SEEMINGLY INVOKE A LOW OVER THE GREAT LAKES REGION TOWARDS AREAS OF
GREATER BAROCLINICITY OFFSHORE. SOMEWHAT CONCERNED. QUESTION WHETHER
THIS IS ANOTHER ONE-/TWO-PUNCH AS WE HAVE SEEN THIS SEASON. NEED TO
WATCH THIS FORECAST PERIOD CLOSELY AS ENERGY BECOMES BETTER SAMPLED
INTO PERIODS OF HIGHER FORECAST RESOLUTION. AM NOT SOLD ON ANYTHING
FOR THE TUESDAY-WEDNESDAY PERIOD AS THE INDIVIDUAL 50-MEMBERS OF THE
EC-ENSEMBLE EXHIBIT A CONSIDERABLE SPREAD.
THURSDAY ONWARD...
OF ONLY CERTAINTY IS THE EXPECTATION OF THE BROAD CYCLONIC PATTERN
PREVAILING ACROSS THE REGION THROUGH WHICH ADDITIONAL ENERGY ALOFT
YIELDS AREAS OF LOW PRESSURE AND ADVERSE WEATHER FOLLOWED BY SHOTS
OF COLD ARCTIC AIR. APPEARING AS IF THE SNOWY AND BELOW-NORMAL TEMP
PATTERN CONTINUES...NEVER ENDING. CPC 6-10/8-14 AND CIPS ANALOGS AT
192-HOURS OUT WOULD ALL AGREE THAT WE REMAIN IN THE FREEZER.
&&
.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TONIGHT/...
TODAY...MODERATE CONFIDENCE...MAINLY DUE TO TIMING ISSUES WITH
HEAVIER SNOWBANDS. STORM INTENSIFYING RAPIDLY OFFSHORE. N WINDS
GUSTING AROUND 40-50 KTS ACROSS MUCH OF INTERIOR SRN NEW ENGLAND
WITH GUSTS AROUND 50-65 KTS ACROSS E AND SE COASTAL TERMINALS
WHERE +SN/BLSN EXPECTED. STRONGEST WINDS AROUND MIDDAY. CIGS WILL
IMPROVE ACROSS CENTRAL AND WESTERN AREAS TO VFR...BUT LOW LEVEL
VSBYS REDUCED WITH BLSN.
TONIGHT...MAINLY VFR CIGS ACROSS SOUTHERN NEW ENGLAND. MVFR CIGS
ACROSS OUTER CAPE COD. SOME QUESTION WITH VISIBILITY DUE TO BLSN.
EXPECTING A TREND TO VFR WITH DIMINISHING WIND.
KBOS TAF...MODERATE CONFIDENCE IN TAF.
KBDL TAF...MODERATE CONFIDENCE IN TAF.
OUTLOOK...MONDAY THROUGH THURSDAY...
MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.
BLUSTERY NW-WINDS EARLY UP AROUND 25-35 KTS LIKELY TO RESULT IN BLSN
WITH IFR-LIFR VSBYS. WINDS DIMINISH INTO EVENING. LOW-END VFR / MVFR
OCEAN-EFFECT CIGS MAY LINGER ACROSS THE CAPE / ISLANDS. INCREASING
MID- TO HIGH CLOUDS INTO TUESDAY.
TUESDAY INTO WEDNESDAY...LOW CONFIDENCE.
SNOW POSSIBLE PARENT WITH IFR-LIFR OUTCOMES. N/NW-WINDS PERHAPS
BLUSTERY.
THURSDAY...LOW CONFIDENCE.
VFR. NW-WINDS. LOW-END VFR / MVFR OCEAN-EFFECT CIGS LINGERING ACROSS
THE CAPE / ISLANDS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TONIGHT/...
THROUGH TONIGHT...MODERATE CONFIDENCE.
EXPECT WINDS TO EVENTUALLY BACK N-NE THIS MORNING AND RAPIDLY
INCREASE. EXPECT SUSTAINED WINDS UP TO 50-60 KT AND GUSTS UP TO
60-70 KT THROUGH TODAY...HIGHEST ACROSS THE EASTERN WATERS. SEAS
WILL BUILD UP TO AROUND 15 FT TONIGHT WILL BUILD UP TO AROUND 25
FT ACROSS THE EASTERN WATERS TODAY.
HEADLINES ON THE WATERS CONTINUED. CONSIDERED THE NEED FOR
FREEZING SPRAY ADVISORIES IN BOSTON HARBOR AND NARRAGANSETT BAY.
WHILE IT IS TOUGHER TO GENERATE FREEZING SPRAY WITH MUCH LOWER
SEAS AND REDUCED FETCH ON THOSE BODIES OF WATER...VESSEL SPEEDS
WILL BE CRUCIAL. EXPECTING REDUCED VISIBILITIES IN MODERATE TO
HEAVY SNOW.
OUTLOOK...MONDAY THROUGH THURSDAY...
MONDAY INTO MONDAY NIGHT...HIGH CONFIDENCE.
BLUSTERY NW-WINDS EARLY UP AROUND 35-40 KTS RESULTING IN SEAS AROUND
10-14 FEET ON THE OUTER WATERS. MODERATE-HEAVY FREEZING SPRAY WITH
AN ARCTIC AIRMASS MOVING OVER THE WATERS. ACTIVITY DIMINISHING INTO
MONDAY EVENING WITH GALES DROPPING OFF TO SMALL-CRAFTS AS FREEZING
SPRAY WARNINGS CONVERT TO HEADLINES. MOST HEADLINES DROP OFF TUESDAY
MORNING WITH ONLY SMALL-CRAFTS HOLDING ON THE OUTER WATERS FOR SEAS.
TUESDAY INTO WEDNESDAY...LOW CONFIDENCE.
OFFSHORE STORM LIKELY. PROXIMITY TO S NEW ENGLAND UNCERTAIN. SNOW
POSSIBLE. N/NW-WINDS PERHAPS BLUSTERY POTENTIALLY TO GALE-FORCE.
INCREASING SEAS POSSIBLE.
THURSDAY...LOW CONFIDENCE.
IN WAKE OF THE STORM...BLUSTERY NW-WINDS POSSIBLY TO GALE-FORCE.
POTENTIAL FOR LINGERING SNOW. SEAS INCREASE. FREEZING SPRAY ISSUES.
&&
.TIDES/COASTAL FLOODING...
MINOR TO MODERATE COASTAL FLOODING AND AREAS OF SIGNIFICANT BEACH
EROSION ARE EXPECTED FOR THE SALISBURY TO CAPE ANN AND HULL TO
DENNIS REACHES OF COASTLINE. THE COASTAL FLOOD WARNING REMAINS IN
EFFECT FOR THOSE AREAS. MINOR COASTAL FLOODING IS STILL EXPECTED
ALONG A FEW PORTIONS OF SHORE BORDERING BOSTON HARBOR AND NANTUCKET
HARBOR...AND A COASTAL FLOOD ADVISORY REMAINS IN EFFECT THERE. THE
NORTH SHORE FROM GLOUCESTER TO LYNN TECHNICALLY FALLS UNDER THE
COASTAL FLOOD WARNING BUT THAT IS ONLY BECAUSE THE ZONE INCORPORATES
ALL OF THE ESSEX COUNTY COAST. WE ANTICIPATE NO WORSE THAN MINOR
COASTAL FLOODING FROM GLOUCESTER TO LYNN WITH THIS STORM.
WE HAVE ONLY MADE FAIRLY MINOR TWEAKS TO THE FORECAST STORM SURGE
AND WAVE HEIGHT FOR THE TIME OF THE HIGH TIDE THIS MORNING...730
AM TO 830 AM MOST LOCATIONS. THE LATEST POSITIONING/CONFIGURATION
OF THE LOW LEVEL JET WAS IMPETUS TO INCREASE THE STORM SURGE BY A
FEW TENTHS ALONG THE SCITUATE TO DENNIS REACH OF COASTLINE. THE
OVERALL PICTURE OF EXPECTED IMPACTS AND WARNINGS/ADVISORIES HAS
NOT CHANGED APPRECIABLY. AT THE TIME OF THIS MORNING/S HIGH
TIDE...WE ANTICIPATE A STORM SURGE OF 2 TO 2.5 FEET ALONG THE MA
EAST COAST AND WAVES 15 TO 20 FEET SEVERAL MILES OFF THE COAST.
THE SURGE AND SEAS WILL CONTINUE TO BUILD DURING THE OUTGOING TIDE
AND WILL PROBABLY CAUSE THE TIDE TO RECEDE MUCH SLOWER THAN NORMAL
AND MAY EVEN CREST AS MUCH AS A HALF HOUR AFTER THE TIME OF THE
SCHEDULED ASTRONOMICAL HIGH TIDE IN SOME LOCATIONS. ALONG THE CAPE
COD BAY SHORE FROM SANDWICH TO DENNIS...THE STORM SURGE MAY CREST
NEAR OR EVEN A LITTLER HIGHER THAN 3.5 FEET BUT SEVERAL HOURS AFTER
THE TIME OF THE ASTRONOMICAL HIGH TIDE.
THIS EVENING/S HIGH TIDE IS LOWER ASTRONOMICALLY...AND THE WIND
SHOULD HAVE BECOME OFFSHORE FOR MOST SHORELINES BY THAT TIME. THUS
WE ANTICIPATE AT THIS TIME LITTLE OR NO IMPACT FOR THIS HIGH TIDE.
&&
.CLIMATE...
PRESIDENTS DAY MONDAY WILL BE VERY COLD ALTHOUGH SOME OF THAT WILL
BE DUE TO THE WIND. SOME OF THE LOW MAXIMUM RECORDS MAY BE AT
RISK. HERE ARE THE COLD TEMPERATURE RECORDS FOR THAT DATE.
FEBRUARY 16 RECORD LOW
BOSTON ......-9 IN 1943 PROVIDENCE...-10 IN 1943 WORCESTER....
-24 IN 1943 HARTFORD ....-24 IN 1943
FEBRUARY 16 RECORD LOW MAXIMUM
BOSTON ......14 IN 1943 PROVIDENCE...16 LATEST IN 1943
WORCESTER....12 LATEST IN 1963 HARTFORD.....12 IN 2003
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WIND CHILL WARNING FROM 4 PM THIS AFTERNOON TO 8 AM EST MONDAY
FOR CTZ002>004.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR CTZ002-
003.
WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR CTZ004.
MA...WIND CHILL ADVISORY FROM 4 PM THIS AFTERNOON TO 11 AM EST
MONDAY FOR MAZ020>024.
BLIZZARD WARNING UNTIL 4 AM EST MONDAY FOR MAZ005-013-017-018-
020-021-023.
COASTAL FLOOD WARNING UNTIL 11 AM EST THIS MORNING FOR MAZ007-
019-022.
WIND CHILL WARNING FROM 4 PM THIS AFTERNOON TO 8 AM EST MONDAY
FOR MAZ005>007-010>019-026.
BLIZZARD WARNING UNTIL 7 AM EST MONDAY FOR MAZ006-007-014>016-
019-022-024.
COASTAL FLOOD ADVISORY UNTIL 11 AM EST THIS MORNING FOR MAZ015-
016-024.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR MAZ002-
003-008>011.
BLIZZARD WARNING UNTIL 7 PM EST THIS EVENING FOR MAZ004-012-
026.
WIND CHILL WARNING FROM 4 PM THIS AFTERNOON TO 11 AM EST
MONDAY FOR MAZ002>004-008-009.
RI...WIND CHILL ADVISORY FROM 4 PM THIS AFTERNOON TO 11 AM EST
MONDAY FOR RIZ006>008.
BLIZZARD WARNING UNTIL 4 AM EST MONDAY FOR RIZ006>008.
WIND CHILL WARNING FROM 4 PM THIS AFTERNOON TO 8 AM EST MONDAY
FOR RIZ001>004.
BLIZZARD WARNING UNTIL 7 PM EST THIS EVENING FOR RIZ001>005.
MARINE...HEAVY FREEZING SPRAY WARNING FROM 10 AM THIS MORNING TO 1 PM
EST MONDAY FOR ANZ231>235-237-250-251-254>256.
HURRICANE FORCE WIND WARNING UNTIL 7 PM EST THIS EVENING FOR
ANZ231-232-250-254-255.
STORM WARNING UNTIL 5 AM EST MONDAY FOR ANZ230-233>237-251-256.
&&
$$
SYNOPSIS...BELK/SIPPRELL
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...SIPPRELL
AVIATION...BELK/SIPPRELL
MARINE...BELK/SIPPRELL
TIDES/COASTAL FLOODING...
CLIMATE...
AREA FORECAST DISCUSSION
NWS CARIBOU ME
704 AM EST SUN FEB 15 2015
.SYNOPSIS...
A NOR`EASTER WILL RAPIDLY INTENSIFY ACROSS THE GULF OF MAINE
TODAY AND MOVE SLOWLY ACROSS THE CANADIAN MARITIMES TONIGHT AND
MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
630 AM UPDATE: FURTHER ADJUSTMENTS NEEDED ON THE SNOWFALL SIDE AS
WELL AS THE PLACEMENT. THIS MEAN LESS SNOWFALL FOR THE BANGOR-
LINCOLN REGION DOWN INTO BAR HARBOR. EAST OF THERE, IT LOOKS LIKE
SNOWFALL COULD BE ENHANCED FOR A TIME INTO THE AFTERNOON. THE
LATES RAP CONTINUES TO HAVE A GOOD LOCK ON THINGS OVERALL
W/ENHANCED SNOWFALL PIVOTING BACK ACROSS EASTERN AROOSTOOK COUNTY
AND WASHINGTON COUNTY. FURTHER W, RADAR NOT SHOWING MUCH AS DRY
AIR WORKING N AS SEEN ON THE WATER VAPOR IMAGERY. IR SATELLITE
IMAGERY SHOWED LARGE AREA OF ENHANCEMENT WORKING UP ACROSS EASTERN
MAINE AND NEW BRUNSWICK. ANOTHER AREA OF ENHANCEMENT WAS WORKING
UP FROM THE GULF OF MAINE.
A MAJOR SHIFT IN THINGS THIS MORNING AS THE BEST DEFORMATION
BANDING NOW LOOKS TO BE ACROSS SOUTHERN MAINE TOWARD GYX`S
CWA(YORK COUNTY) AND ACROSS COASTAL AND EASTERN MAINE(HANCOCK AND
WASHINGTON COUNTY). THIS WILL MEAN LESS SNOWFALL WEST OF THE ROUT
ONE CORRIDOR FROM HOULTON DOWN THROUGH MACHIAS.
THE LATEST SURFACE ANALYSIS SHOWED INTENSIFYING LOW PRES PULLING
NE TOWARD THE GULF OF MAINE. IR SATELLITE IMAGERY SHOWED THE BEST
ENHANCED CLOUD TOPS MOVING NORTHWARD ACROSS EASTERN 1/2 OF MAINE.
UNDER THIS ENHANCED AREA WILL BE MODERATE SNOW W/PERIODS OF HEAVY
SNOW. FURTHER W, THINGS DROP OFF AND FORCING AND CONVERGENCE ARE
WEAKER. THE 07Z RADAR LOOP SHOWED 2 AREAS OF BANDING OCCURRING. ONE
WAS OVER SOUTHERN MAINE NEAR YORK COUNTY AND THE OTHER AREA WAS
MOVING ACROSS EASTERN WASHINGTON COUNTY. WE HAD REPORTS THROUGH 3
AM OF 6 TO 8 INCHES IN CENTRAL AND COASTAL WASHINGTON COUNTY AND
LESS AS ONE TRAVELS N AND W. THE LATEST RUNS OF THE NAM/RAP AND
CANADIAN GEM WERE DOING WELL W/THE PLACEMENT OF THE PRECIP SHIELD
AND ENHANCED BANDING FURTHER E. THEREFORE, CHANGES WERE MADE TO
LOWER THE QPF/SNOWFALL AMOUNTS WEST OF THE ROUTE 1 CORRIDOR SAY
FROM HOULTON SOUTHWARD TO MACHIAS AS FORCING AND DEFORMATION
BANDING ARE WEAKER. HIGHEST AMOUNTS WILL BE IN WASHINGTON COUNTY
AS ANYWHERE FROM 16 TO 24 INCHES COULD ACCUMULATE ESPECIALLY IN
THE CALAIS AND EASTPORT AREAS. THE BANGOR AND LINCOLN REGIONS
COULD RECEIVE 6 TO 9 INCHES OF FLUFFY SNOW WHILE FURTHER WEST AND
NORTH, AMOUNTS DROP OFF W/4 TO 8 INCHES FOR NW MAINE SUCH AS THE
ST. JOHN VALLEY. DECIDED TO KEEP THE EASTERN SIDE OF MAINE IN THE
8 TO 12 INCH RANGE FROM CARIBOU DOWN INTO HOULTON AS SOME
ENHANCED BANDING IS SHOWN TO WRAP BACK AS THE LOW EXPLODES HEADING
TOWARD NOVA SCOTIA.
NNW WINDS WILL CRANK UP TODAY AS ADVERTISED. MODEL SOUNDINGS
STILL SUPPORT SUSTAINED WINDS TO 30 TO 40 MPH OVER THE DOWNEAST
AND COAST W/GUST POTENTIAL TO 55 TO 65 MPH ESPECIALLY ALONG THE
IMMEDIATE COAST AND EASTERN WASHINGTON COUNTY. FURTHER NORTH AND
WEST, 25 TO 35 W/GUSTS TO 50 MPH EXPECTED RIGHT INTO TONIGHT.
GIVEN THE STRONG WINDS AND SNOWFALL EXPECTED, DECIDED TO STAY
W/THE CURRENT HEADLINES AND STRESS THE IMPACT DUE TO BLOWING AND
DRIFTING SNOW AND WHITEOUTS. TRAVEL COULD BE TREACHEROUS AS THE
STRONG WINDS WILL MAKE SNOW REMOVAL DIFFICULT.
SO FOR THE HEADLINES, THE MAIN ADJUSTMENT WAS FOR THE WESTERN
AREAS OF NORTHERN AND CENTRAL AND PISCATAQUIS COUNTY AS WELL AS
NORTHERN SOMERSET COUNTY AS A WINTER WEATHER ADVISORY IS IN EFFECT
AS SNOWFALL WILL BE HARD PRESSED TO HIT 4 INCHES, BUT THE WIND
ONCE AGAIN WILL BE THE MAIN ISSUE. ALSO, GIVEN THE WINDS AND VERY
COLD TEMPERATURES TONIGHT, DECIDED TO PLACE THESE AREAS UNDER A
WIND CHILL WARNING FOR WIND CHILLS AS LOW AS 35 BELOW. THIS WAS
COLLABORATED W/GYX THIS MORNING. THE WIND CHILLS WILL BE A CONCERN
TONIGHT ELSEWHERE W/THE GUSTY NNW WINDS. THE DAYCREW CAN ASSESS
THIS FURTHER TODAY.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
BLOWING SNOW AND SLOWLY DIMINISHING WINDS WILL BE THE HIGHLIGHTS
FOR WASHINGTONS BIRTHDAY. MUCH BELOW NORMAL TEMPERATURES WILL
PERSIST THROUGH TUESDAY WITH ARCTIC HIGH PRESSURE IN FIRM CONTROL.
A COASTAL STORM MAY BRING A CHANCE OF LIGHT SNOW TO THE COAST
TUESDAY AFTERNOON.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COASTAL LOW PRESSURE SYSTEM WILL PASS TO THE SOUTH AND EAST OF
MAINE TUESDAY NIGHT WITH A CONTINUED CHANCE OF SNOW MAINLY NEAR THE
COAST. A FULL LATITUDE UPPER TROUGH SETS UP ALONG THE EAST COAST
LATER THIS WEEK FOR A REINFORCING SHOT OF ARCTIC AIR. LIGHT SNOW
WILL BE POSSIBLE WITH AN ARCTIC FRONT WEDNESDAY INTO THURSDAY.
&&
.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: MVFR/VFR THIS MORNING FOR THE NORTHERN TERMINALS BUT
CONDITIONS SHOULD DETERIORATE TODAY INTO TONIGHT DOWN TO IFR
W/LLWS AND VSYS AT TIMES LESS THAN 1/2SM. KBGR AND KBHB WILL IFR
TO LIFR TODAY W/SOME IMPROVEMENT TO MVFR TONIGHT TO EVEN VFR LATE,
BUT WINDS WILL LEAD TO LLWS AND SEVERE TURBULENCE.
SHORT TERM: MVFR OR IFR CONDITIONS IS EXPECTED AT TAF SITES ON
MONDAY DUE TO BLOWING SNOW AND AGAIN WEDNESDAY NIGHT INTO THURSDAY
IN SNOW.
&&
.MARINE...
NEAR TERM: STORM WARNING AND HEAVY FREEZING SPRAY WARNING REMAINS
IN PLACE. WINDS ARE APCHG GALE FORCE ATTM AND WILL INCREASE TO
STORM LATER THIS MORNING W/GUST POSSIBLE TO 60+ KTS. THE OUTER
WATERS COULD ACTUALLY SEE HURRICANE FORCE WIND GUSTS. DID NOT MAKE
ANY ADJUSTMENTS TO THE SEAS AS AN INCREASE TO 14 TO 20 FT LOOKS
IN ORDER ESPECIALLY OVER THE OUTER WATERS.
SHORT TERM: A GALE WARNING WILL BE NEEDED THROUGH MONDAY EVENING
WITH WIND GUSTS IN EXCESS OF 40 MPH. FREEZING SPRAY WILL REMAIN A
HAZARD MONDAY WITH HEAVY ICE ACCUMULATION POSSIBLE.
&&
.TIDES/COASTAL FLOODING...
THE COASTAL FLOOD STATEMENT WILL BE ALLOWED TO DROP OFF AT 8 AM.
PRIMARY CONCERN IS HIGH TIDE AT 0657 W/10.4 FEET AT BAR HARBOR.
WIND DIRECTION WILL TAKE A AN OFFSHORE DIRECTION PRIOR TO HIGH
TIDE THIS MORNING. STORM SURGE IS NOT QUITE AS HIGH BUT WE DO
STILL EXPECT A 1 TO 1.5 FOOT SURGE WHICH WOULD MAKE MAXIMUM STORM
TIDE LEVEL TO SLIGHTLY UNDER 12 FEET. THE WIND DIRECTION WILL KEEP
LARGEST WAVES WELL OFFSHORE WITH WAVE HEIGHTS APPROACHING THE SURF
ZONE AT TIME OF HIGH TIDE AROUND 7 FEET. A SECONDARY LONGER PERIOD
WAVE SYSTEM IS SHOWN TO ARRIVE FROM THE SOUTHEAST AT TIME OF HIGH.
WAVE HEIGHTS WITH THIS WAVE GROUP APPEAR TO BE LIMITED TO AROUND 5
FEET. GIVEN THE LIMITED WAVE HEIGHTS APPROACHING THE COAST, ONLY
MINOR OVERTOPPING IS POSSIBLE IN SOME EXPOSED AREAS AT TIME OF
HIGH TIDE THIS MORNING.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MEZ001-002-005-
006.
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MEZ003-004-
010.
WIND CHILL WARNING FROM 1 AM TO 8 AM EST MONDAY FOR MEZ003-004-
010.
BLIZZARD WARNING UNTIL 7 AM EST MONDAY FOR MEZ011-015>017-
029>032.
MARINE...HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 11 AM
EST MONDAY FOR ANZ050>052.
STORM WARNING UNTIL 7 AM EST MONDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...OKULSKI
LONG TERM...OKULSKI
AVIATION...HEWITT/OKULSKI
MARINE...HEWITT/OKULSKI
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS DULUTH MN
517 AM CST SUN FEB 15 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 336 AM CST SUN FEB 15 2015
AN ARCTIC HIGH PRESSURE DESCENDING INTO THE UPPER GREAT LAKES TODAY
WILL BE FOLLOWED BY A WEAK CLIPPER SYSTEM WHICH WILL BRING A CHANCE
FOR LIGHT SNOWFALL ACCUMULATIONS TODAY/TONIGHT. PRIMARY CONCERN FOR
THE SHORT TERM IS TIMING AND INTENSITY OF SNOWFALL AS A RESULT OF
THIS CLIPPER SYSTEM TODAY. ANOTHER CONCERN OF A MUCH SMALLER SPATIAL
SCALE IS CONVERGENCE OVER LAKE SUPERIOR RESULTING IN LAKE EFFECT
SNOW SHOWERS POSSIBLY AFFECTING THE NORTH AND/OR SOUTH SHORE NEAR
THE TWIN PORTS. TEMPERATURES WARM UP BRIEFLY MONDAY AS LOW/MID LEVEL
WINDS BECOME OUT OF THE SOUTHWEST LATE SUNDAY INTO MONDAY.
EARLY THIS MORNING...WEAK CONVERGENCE OVER LAKE SUPERIOR WEST OF A
LINE FROM SILVER BAY TO THE BAYFIELD PENINSULA POSSIBLY MAY LEAD TO
LAKE EFFECT SNOW SHOWER DEVELOPMENT. THIS IS EVIDENT ON RADAR AS
WEAK ECHOES AS WELL AS AN INTERMITTENT 2KFT CEILING DEVELOPING AT
SUPERIOR AIRPORT AND DULUTH SKY HARBOR. MOST SHORT-RANGE GUIDANCE IS
NOT PICKING UP ON THIS WITH THE EXCEPTION OF THE 00Z GEM-REGIONAL.
NO SURFACE REPORTS OF SNOWFALL AS OF 09Z /3 AM CST/ THIS
MORNING...WITH THE EXCEPTION OF ASHLAND WHERE FAVORABLE LAKE EFFECT
CONDITIONS HAVE EXISTED FOR A LONGER PERIOD OF TIME DUE TO A VERY
LIGHT BUT PERSISTENT NORTHEASTERLY WIND. WORKING AGAINST LAKE
EFFECT SNOW SHOWERS IS LESS THAN OPTIMAL MOISTURE AT LOW LEVELS AND
SOME WEAK DIRECTIONAL SHEAR AT LOW LEVELS PREVENTING A PERSISTENT
BAND FROM DEVELOPING. OPTED TO INCLUDE SOME ISO/SCT SNOW SHOWER
WORDING IN EARLY THIS MORNING...AND WILL CONTINUE TO MONITOR AND
UPDATE AS RADAR/OBS WARRANT. OTHERWISE...TEMPERATURES APPEAR ON
TRACK WITH PORTIONS OF BORDERLAND /SUCH AS INL/ NOT DIPPING AS LOW
AS ORIGINALLY EXPECTED DUE TO HIGH LEVEL CLOUD COVER.
TODAY...PRIMARY CONCERN IS A CLIPPER SYSTEM WHICH WILL BRING A BRIEF
PERIOD OF LIGHT SNOW SHOWERS. INCREASED POPS SLIGHTLY WHILE
ATTEMPTING TO CAPTURE THE FACT THAT INITIALLY THIS AFTERNOON THE
DURATION OF SNOWFALL WILL BE JUST A FEW HOURS. SNOW AMOUNTS WILL BE
A COATING TO AN INCH AT MOST...AND CURRENT SNOWFALL FORECAST MAY BE
ON THE HIGH SIDE...BUT AM COUNTING ON A HIGH SNOW RATIO /AROUND 20
TO 1/ SIMILAR TO FRIDAY MORNING IN THE TWIN PORTS AREA. A LITTLE
CONCERNED THAT THE HRRR/HIRES ARW ARE DIMINISHING THE LARGE-SCALE
LIFT AS THE CLIPPER MOVES TOWARDS THE WESTERN EDGE OF THE CWA THIS
MORNING...BUT 00Z AND 06Z NAM/NAM 4KM CONUS NEST/HIRES NMM AND
LATEST FEW RUNS OF RAP ARE MORE SUPPORTIVE OF CURRENT FORECAST. LOW
LEVEL LAPSE RATES WILL SUPPORT MIXING TO AROUND 900MB AT TIMES THIS
AFTERNOON...AND WHILE LOW LEVEL WINDS ARE NOT VERY STRONG COULD SEE
A FEW GUSTS IN THE 15-20KT RANGE DURING AND FOLLOWING SNOW SHOWERS
TODAY. TEMPERATURES RISING TO THE SINGLE DIGITS ABOVE ZERO IN MOST
LOCATIONS.
TONIGHT...SNOW SHOWERS END IN MOST LOCATIONS AS WEAK MID-LEVEL
RIDGING DEVELOPS OVER SOUTHERN ONTARIO TOWARDS MORNING. FOLLOWING
THE MAIN CLIPPER A SECONDARY 925/850MB TROUGH WILL MOVE THROUGH
CENTRAL MINNESOTA AND NORTHWEST WISCONSIN...AND WITH LOW LEVEL
MOISTURE ALREADY IN PLACE COULD SEE FLURRIES/LIGHT SNOW DEVELOPING.
UNLIKE PREVIOUS FEW EVENTS THERE TEMPS THROUGH THE COLUMN WILL BE
EITHER WITHIN OR COLDER THAN THE DENDRITIC GROWTH ZONE...SO FREEZING
DRIZZLE WILL NOT BE A CONCERN. TEMPERATURES FALLING TO NEAR TO
SINGLE DIGITS BELOW ZERO...WITH USUAL COLD SPOTS IN THE ARROWHEAD
REGION OF MINNESOTA DROPPING INTO THE MID-TEENS BELOW ZERO. MOST
GUIDANCE IS COLDER FOR THE LOW TEMPS...BUT SINCE CLOUDS WILL REMAIN
IN PLACE ALL NIGHT AND LOW LEVEL WINDS HAVE A SOUTHERLY COMPONENT
DECIDED TO GO A BIT WARMER THAN MODEL CONSENSUS.
MONDAY....WINDS TURN OUT OF THE WEST/NORTHWEST AND PRESSURE GRADIENT
OVER MINNESOTA INCREASES AS YET ANOTHER ARCTIC HIGH PRESSURE
DESCENDS FROM THE CANADIAN PRAIRIE TOWARDS THE NORTHERN HIGH
PLAINS. WINDS MAY BECOME BREEZY IN THE AFTERNOON...GUSTING TO
AROUND 20KTS AT TIMES. A LOW/MID LEVEL CLOUD DECK WILL STICK
AROUND MOST OF THE DAY...AND STEEP LOW LEVEL LAPSE RATES COULD
LEAD TO A FEW SNOW SHOWERS OR FLURRIES THROUGHOUT THE DAY DESPITE
A LACK OF GREAT LARGE-SCALE LIFT /BUT ABSENCE OF OVERWHELMING
LARGE-SCALE SUBSIDENCE/. TEMPS WARMER...RISING TO THE LOW TO MID
TEENS...AND EVEN NEAR 20 ALONG THE INTERSTATE 35 CORRIDOR.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 336 AM CST SUN FEB 15 2015
AN UPPER LOW ANCHORED NEAR HUDSON BAY WILL REMAIN NEARLY STATIONARY
FROM MONDAY NIGHT THROUGH FRIDAY. AT THE SFC...THIS TRANSLATES INTO
ARCTIC HIGH PRESSURE DRIFTING OVER THE FORECAST AREA FROM MANITOBA
MONDAY NIGHT THROUGH THURSDAY. COLD...DRY AIR WILL BE LOCKED IN
PLACE DURING THIS TIME. A NW FLOW WILL BE OVER THE FORECAST AREA AS
WELL AS OVER LAKE SUPERIOR. LAKE EFFECT SNOW SHOWERS WILL OCCUR
REGULARLY OVER THE GOGEBIC RANGE OF NE ASHLAND AND NORTHERN IRON
COUNTIES MONDAY NIGHT THROUGH THURSDAY. SNOW AMOUNTS WILL BE LIMITED
HOWEVER AS THIS TYPE OF AIRMASS WILL INDUCE ICE FORMATION ON LAKE
SUPERIOR AND WILL LIMIT THE ACCUMULATION POTENTIAL.
REGARDLESS...WILL HAVE SOME POPS THROUGH THIS PERIOD...EVEN INTO
SOUTHERN ASHLAND AND IRON COUNTIES. EACH NIGHT WILL HAVE THE
CAPABILITY OF LOW WIND CHILL VALUES...BUT WILL SAVE THE HEADLINES
FOR A LATER TIME AS THE SFC WIND DECOUPLES EACH NIGHT. FRIDAY AND
FRIDAY NIGHT WILL BE AFFECTED BY A CLOSED LOW PUSHING A SFC LOW
THROUGH THE FORECAST AREA. SOME LIGHT ACCUMULATIONS ARE ANTICIPATED.
SATURDAY FINDS THE RETURN OF ARCTIC HIGH PRESSURE TO THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 517 AM CST SUN FEB 15 2015
DEPARTING HIGH PRESSURE RESULTS IN VFR ACROSS THE TERMINALS AT THE
START OF THE FORECAST. BY MID DAY...LIGHT SNOW WILL SPREAD OVER
THE TERMINALS FROM WEST TO EAST AS AN UPPER LEVEL SHORT WAVE MOVES
ALONG THE INTERNATIONAL BORDER. CIGS/VSBYS DROP INTO THE MVFR
RANGE WITH ISOLD IFR VSBYS IN MORE ROBUST AREAS OF SNOW. VSBYS
WILL IMPROVE TO VFR AFTER 22Z...BUT LIGHT SNOW/FLURRIES WILL
PERSIST THROUGH THE END OF THE FORECAST WITH MVFR CIGS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 5 0 16 -9 / 80 40 10 0
INL 6 -12 10 -17 / 60 10 10 0
BRD 9 4 16 -7 / 80 20 10 0
HYR 6 1 15 -6 / 30 30 20 0
ASX 6 1 15 -3 / 40 30 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...JJM
LONG TERM...GSF
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
956 AM EST SUN FEB 15 2015
.SYNOPSIS...
HIGH PRESSURE MOVING IN TODAY. WINTER STORM MONDAY AND MONDAY NIGHT
THEN COLD WITH SNOW SHOWERS AT TIMES FOR REMAINDER OF WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1000 AM UPDATE...
CLEANED UP THE WIND CHILL HEADLINES THIS MORNING TO REFLECT
TRENDS. ANXIOUSLY AWAITING FULL 12Z MODEL SUITE CONCERNING SYSTEM
ON MONDAY. GIVEN HOW BIG OF A N SHIFT THERE IS FROM JUST 24 HRS
AGO...NOT JUMPING THE GUN ON A WARNING UNTIL I SEE THE 12Z RUNS.
PREVIOUS DISCUSSION BELOW...
NAM AND RAP INDICATE 850MB TEMPS DOWN INTO THE -20C TO -25C RANGE
ACROSS CWA EARLY THIS MORNING. THIS COLD AIR CONTINUES TO SQUEEZE
OUT FLURRIES AND LIGHT SNOW SHOWERS VISIBLE ON RADAR AND IR
SAT...WHICH SHOULD GRADUALLY TAPER OF OVER THE NEXT 6 HOURS AS
MOISTURE CONTINUES TO LESSEN. WITH PERSISTENT REDUCED VISIBILITY
AT EKN...WILL EXTEND WINTER WEATHER ADVISORY IN
POCAHONTAS...WEBSTER AND RANDOLPH COUNTIES UNTIL 9AM/14Z...FOR
SNOW AND BLOWING SNOW.
STRUGGLING TO GET WIND CHILLS DOWN TO CRITERIA IN THE WIND CHILL
WARNING EXCEPT AT THE HIGHER ELEVATIONS. HOWEVER WITH A FEW MORE
HOURS OF COOLING...DO NOT HAVE ANY CHANGES PLANNED. HAVE ADVISORY
CRITERIA WIND CHILLS ACROSS THE NORTH AGAIN LATE TODAY AND TONIGHT
AND WILL LIKELY NEED AN ADVISORY. HOWEVER...TO AVOID CONFUSION OF
HAVING A WARNING AND ADVISORY FOR THE SAME COUNTIES WILL DEFER THE
ADVISORY TO THE DAY SHIFT. WILL ADD MENTION TO THE HWO.
POPS BEGIN INCREASING FROM THE SW LATE TONIGHT. WITH SOME SNOW
MOVING INTO SW VA AND WV COAL FIELDS BY THE END OF THE NEAR TERM
PERIOD. BULK OF THIS SYSTEM WILL BE IN SHORT TERM PERIOD...BUT DO
HAVE WINTER STORM WATCH STARTING AT 11Z ACROSS CENTRAL AND SOUTHERN
CWA.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
THE RIGHT REAR OF AN EXITING 250 MB JET MAX MONDAY MORNING COUPLED
WITH THE LEFT ENTRANCE OF A STRENGTHENING 250 MB JET MAX OVER DIXIE
MONDAY EVENING HAS HELPED MODELS DEVELOP DEEPER MOISTURE FURTHER
NORTH IN THE 00Z RUNS.
TRENDED TO FAVOR MORE THE 00Z GFS AND ECMWF OVER THE LESS ROBUST NAM
SOLUTION. A MID LEVEL DRY SLOT DOES SWEEP INTO OUR SW COUNTIES
MONDAY NIGHT. SO DURATION WILL BE LIMITED TO 12 TO 18 HRS. COLD
SURFACES AND AIR TEMPERATURES WILL ALLOW ANY SNOW TO BE SEEN FIRST
ON UNTREATED PAVEMENTS. YET...A BIT CONCERNED THAT THE COLD AIR
MASS ONLY HAS ABOUT .5 PRECIPITABLE WATER TO OUR SOUTH. WILL FLAKE
SIZE BE LIMITED...ESPECIALLY NORTH OF THE INTERSTATE 64 CORRIDOR IN
THE LOWLANDS.
BEST LIFT APPEARS TO BE FOR OUR SW VA COUNTIES ON NORTH TOWARD BKW.
WILL INCLUDE SOME HEAVY AT TIMES IN WORDING THERE.
WILL POST A WINTER STORM WATCH FOR MONDAY INTO MONDAY NIGHT...EVEN
IN SOME COUNTIES...WERE WE HAD NO MENTION OF POPS PREVIOUSLY FOR
MONDAY. WATCH MOSTLY SOUTH OF ROUTE 50 CORRIDOR IN THE OHIO
VALLEY...THEN THRU CENTRAL WV. OF COURSE...DESPITE SIMILAR
SNOWS...THE HIGHER SNOW CRITERIA IN OUR CENTRAL MOUNTAINS COUNTIES
LIMITS POSTED A WATCH THERE. WITH ALL THE CURRENT
HEADLINES...DECIDED ON 1 GENERAL GROUP FOR THE WATCH...OF COURSE THE
SNOW WILL START LATER ACROSS THE NORTHERN COUNTIES COMPARED TO THE
SOUTH.
TUESDAY SHOULD BE A LULL...BEFORE THE APPROACH OF THE NEXT ARCTIC
TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
DUE TO CONSIDERABLE DIFFERENCES BETWEEN THE OPERATIONAL
MODELS...USED A BLEND OF THE GEFS/ECMWF/AND NAEFS ENSEMBLE MEANS FOR
THE FORECAST. BIG QUESTION FOR TUESDAY NIGHT IS WHETHER A SOUTHERN
SYSTEM GRAZES THE REGION...OR STAYS TOO FAR SOUTH. WILL CONTINUE
WITH CHANCE POPS DUE TO UNCERTAINTY. THE ARCTIC AIRMASS THEN POURS
INTO THE AREA WEDNESDAY INTO THURSDAY...PROVIDING FOR UPSLOPE SNOW.
YET ANOTHER SYSTEM WOULD ARRIVE FRIDAY NIGHT INTO SATURDAY.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
STILL SEEING SOME LIGHT SNOW AND BLOWING SNOW...MAINLY IN THE COAL
FIELDS AND MOUNTAINS. ACTIVITY WILL CONTINUE TO TAPER OFF THROUGH
THE NEXT SEVERAL HOURS. WINDS ARE DECREASING...HOWEVER STILL A BIT
GUSTY INTO THIS AFTERNOON. FEW TO SCT CLOUDS TODAY WILL GIVE WAY TO
THICKENING HIGHER CLOUDS MOVING IN FROM THE SOUTHWEST TONIGHT. SNOW
MOVING BACK IN FROM THE SOUTH MONDAY...ALTHOUGH SHOULD NOT IMPACT
TAF SITES UNTIL AFTER CURRENT TAF PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF SNOW ENDING IN MOUNTAINS MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EST 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY M H H H H H H H H H H H
EKN CONSISTENCY M H H H H H H H M M M M
PKB CONSISTENCY M M H H H H H H H H H H
CKB CONSISTENCY H H M H H H H H H H H M
AFTER 12Z MONDAY...
PERIODS OF IFR POSSIBLE IS SNOW MONDAY INTO MONDAY NIGHT AND AGAIN
WEDNESDAY INTO THURSDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER STORM WATCH FROM MONDAY MORNING THROUGH LATE MONDAY
NIGHT FOR WVZ005>008-013>018-024>028-033>037.
WIND CHILL WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
WVZ035>038-046-047.
WIND CHILL ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
WVZ009>011-017>020-027>034-039-040.
OH...WINTER STORM WATCH FROM MONDAY MORNING THROUGH LATE MONDAY
NIGHT FOR OHZ083-085>087.
WIND CHILL ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ066-
067-075-076-083>085.
KY...WINTER STORM WATCH FROM MONDAY MORNING THROUGH LATE MONDAY
NIGHT FOR KYZ101>103-105.
VA...WINTER STORM WATCH FROM MONDAY MORNING THROUGH LATE MONDAY
NIGHT FOR VAZ003-004.
WIND CHILL ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR VAZ003-
004.
&&
$$
SYNOPSIS...KTB/RPY/MZ
NEAR TERM...MZ/30
SHORT TERM...KTB
LONG TERM...RPY
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
545 AM EST SUN FEB 15 2015
.SYNOPSIS...
HIGH PRESSURE MOVING IN TODAY. WINTER STORM MONDAY AND MONDAY NIGHT
THEN COLD WITH SNOW SHOWERS AT TIMES FOR REMAINDER OF WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
NAM AND RAP INDICATE 850MB TEMPS DOWN INTO THE -20C TO -25C RANGE
ACROSS CWA EARLY THIS MORNING. THIS COLD AIR CONTINUES TO SQUEEZE
OUT FLURRIES AND LIGHT SNOW SHOWERS VISIBLE ON RADAR AND IR
SAT...WHICH SHOULD GRADUALLY TAPER OF OVER THE NEXT 6 HOURS AS
MOISTURE CONTINUES TO LESSEN. WITH PERSISTENT REDUCED VISIBILITY AT
EKN...WILL EXTEND WINTER WEATHER ADVISORY IN POCAHONTAS...WEBSTER
AND RANDOLPH COUNTIES UNTIL 9AM/14Z...FOR SNOW AND BLOWING SNOW.
STRUGGLING TO GET WIND CHILLS DOWN TO CRITERIA IN THE WIND CHILL
WARNING EXCEPT AT THE HIGHER ELEVATIONS. HOWEVER WITH A FEW MORE
HOURS OF COOLING...DO NOT HAVE ANY CHANGES PLANNED. HAVE ADVISORY
CRITERIA WIND CHILLS ACROSS THE NORTH AGAIN LATE TODAY AND TONIGHT
AND WILL LIKELY NEED AN ADVISORY. HOWEVER...TO AVOID CONFUSION OF
HAVING A WARNING AND ADVISORY FOR THE SAME COUNTIES WILL DEFER THE
ADVISORY TO THE DAY SHIFT. WILL ADD MENTION TO THE HWO.
POPS BEGIN INCREASING FROM THE SW LATE TONIGHT. WITH SOME SNOW
MOVING INTO SW VA AND WV COAL FIELDS BY THE END OF THE NEAR TERM
PERIOD. BULK OF THIS SYSTEM WILL BE IN SHORT TERM PERIOD...BUT DO
HAVE WINTER STORM WATCH STARTING AT 11Z ACROSS CENTRAL AND SOUTHERN
CWA.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
THE RIGHT REAR OF AN EXITING 250 MB JET MAX MONDAY MORNING COUPLED
WITH THE LEFT ENTRANCE OF A STRENGTHENING 250 MB JET MAX OVER DIXIE
MONDAY EVENING HAS HELPED MODELS DEVELOP DEEPER MOISTURE FURTHER
NORTH IN THE 00Z RUNS.
TRENDED TO FAVOR MORE THE 00Z GFS AND ECMWF OVER THE LESS ROBUST NAM
SOLUTION. A MID LEVEL DRY SLOT DOES SWEEP INTO OUR SW COUNTIES
MONDAY NIGHT. SO DURATION WILL BE LIMITED TO 12 TO 18 HRS. COLD
SURFACES AND AIR TEMPERATURES WILL ALLOW ANY SNOW TO BE SEEN FIRST
ON UNTREATED PAVEMENTS. YET...A BIT CONCERNED THAT THE COLD AIR
MASS ONLY HAS ABOUT .5 PRECIPITABLE WATER TO OUR SOUTH. WILL FLAKE
SIZE BE LIMITED...ESPECIALLY NORTH OF THE INTERSTATE 64 CORRIDOR IN
THE LOWLANDS.
BEST LIFT APPEARS TO BE FOR OUR SW VA COUNTIES ON NORTH TOWARD BKW.
WILL INCLUDE SOME HEAVY AT TIMES IN WORDING THERE.
WILL POST A WINTER STORM WATCH FOR MONDAY INTO MONDAY NIGHT...EVEN
IN SOME COUNTIES...WERE WE HAD NO MENTION OF POPS PREVIOUSLY FOR
MONDAY. WATCH MOSTLY SOUTH OF ROUTE 50 CORRIDOR IN THE OHIO
VALLEY...THEN THRU CENTRAL WV. OF COURSE...DESPITE SIMILAR
SNOWS...THE HIGHER SNOW CRITERIA IN OUR CENTRAL MOUNTAINS COUNTIES
LIMITS POSTED A WATCH THERE. WITH ALL THE CURRENT
HEADLINES...DECIDED ON 1 GENERAL GROUP FOR THE WATCH...OF COURSE THE
SNOW WILL START LATER ACROSS THE NORTHERN COUNTIES COMPARED TO THE
SOUTH.
TUESDAY SHOULD BE A LULL...BEFORE THE APPROACH OF THE NEXT ARCTIC
TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
DUE TO CONSIDERABLE DIFFERENCES BETWEEN THE OPERATIONAL
MODELS...USED A BLEND OF THE GEFS/ECMWF/AND NAEFS ENSEMBLE MEANS FOR
THE FORECAST. BIG QUESTION FOR TUESDAY NIGHT IS WHETHER A SOUTHERN
SYSTEM GRAZES THE REGION...OR STAYS TOO FAR SOUTH. WILL CONTINUE
WITH CHANCE POPS DUE TO UNCERTAINTY. THE ARCTIC AIRMASS THEN POURS
INTO THE AREA WEDNESDAY INTO THURSDAY...PROVIDING FOR UPSLOPE SNOW.
YET ANOTHER SYSTEM WOULD ARRIVE FRIDAY NIGHT INTO SATURDAY.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
STILL SEEING SOME LIGHT SNOW AND BLOWING SNOW...MAINLY IN THE COAL
FIELDS AND MOUNTAINS. ACTIVITY WILL CONTINUE TO TAPER OFF THROUGH
THE NEXT SEVERAL HOURS. WINDS ARE DECREASING...HOWEVER STILL A BIT
GUSTY INTO THIS AFTERNOON. FEW TO SCT CLOUDS TODAY WILL GIVE WAY TO
THICKENING HIGHER CLOUDS MOVING IN FROM THE SOUTHWEST TONIGHT. SNOW
MOVING BACK IN FROM THE SOUTH MONDAY...ALTHOUGH SHOULD NOT IMPACT
TAF SITES UNTIL AFTER CURRENT TAF PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF SNOW ENDING IN MOUNTAINS MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY M M M M H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY M M M M M M H H H H H H
EKN CONSISTENCY M L H M H H H H H H H M
PKB CONSISTENCY M M M M M H H H H H H H
CKB CONSISTENCY H H M H H H M H H H H H
AFTER 12Z MONDAY...
PERIODS OF IFR POSSIBLE IS SNOW MONDAY INTO MONDAY NIGHT AND AGAIN
WEDNESDAY INTO THURSDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER STORM WATCH FROM MONDAY MORNING THROUGH LATE MONDAY
NIGHT FOR WVZ005>008-013>018-024>028-033>037.
WIND CHILL ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
WVZ005>010-013>019-024>030-033-034.
WIND CHILL WARNING UNTIL 4 PM EST THIS AFTERNOON FOR WVZ011-
020-031-032-035>040-046-047.
WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR WVZ038-
046-047.
OH...WINTER STORM WATCH FROM MONDAY MORNING THROUGH LATE MONDAY
NIGHT FOR OHZ083-085>087.
WIND CHILL ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ075-
083>087.
WIND CHILL WARNING UNTIL 4 PM EST THIS AFTERNOON FOR OHZ066-
067-076.
KY...WINTER STORM WATCH FROM MONDAY MORNING THROUGH LATE MONDAY
NIGHT FOR KYZ101>103-105.
WIND CHILL ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
KYZ101>103-105.
VA...WINTER STORM WATCH FROM MONDAY MORNING THROUGH LATE MONDAY
NIGHT FOR VAZ003-004.
WIND CHILL ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR VAZ003-
004.
&&
$$
SYNOPSIS...KTB/RPY/MZ
NEAR TERM...MZ
SHORT TERM...KTB
LONG TERM...RPY
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
930 AM CST SUN FEB 15 2015
.UPDATE...CANCELLED WIND CHILL ADVISORY EARLY AS THE HIGH HAS
SETTLED IN AND EASED THE WINDS. SO WIND CHILL EXPECTED TO
MODERATE FROM THE MINUS TEENS.
KEEPING AN EYE ON LAKE EFFECT BAND SHIFTING WESTWARD TOWARDS THE
SHORE. AT THIS TIME PREFER THE HI-RES NMM AND LATEST HRRR POPS
WHICH SWINGS THE BAND ONSHORE FOR A TIME. NOT DOING MUCH WITH THE
AMOUNTS AT THIS TIME GIVEN A LITTLE WEAKENING TREND TO THE
REFLECTIVITIES. BUT FELT A BOOST IN POPS WAS JUSTIFIED NEAR THE
SHORE GIVEN THE MOMENTUM OF THE BAND. BUFKIT SOUNDINGS SHOW
INVERSION HEIGHTS BETWEEN 5K AND 6K WITH DELTA T VALUES OVER 20
WITH KGRB MRNG RAOB SHOWING -22C.
PC
&&
.AVIATION/18Z TAFS/...LAKE EFFECT BAND LIKELY TO AFFECT LOCALES
FROM KMKE SOUTHWARD TO THE IL BORDER FROM AT LEAST LATE MORNING
INTO MID AFTERNOON. BAND HAS WEAKENED SOMEWHAT BUT STILL ENOUGH
MOMENTUM AND MODEL SUPPORT TO LOWER CIGS/VSBYS ESP FOR KMKE THOUGH
KENW AND KUES MORE QUESTIONABLE FURTHER INLAND. MID LEVEL DECK
SPREADING IN FROM WRN WI AND IA WITH WEAK WAA AND SHORTWAVE
TRAVERSING WELL TO OUR NORTH.
PC
&&
.MARINE...NUMEROUS LAKE EFFECT SNOW SHOWERS WILL AFFECT THE NEARSHORE
WATERS SOUTH OF NORTH POINT LIGHT TODAY WITH MORE ISOLATED SNOW SHOWERS
POSSIBLY AFFECTING THE NEARSHORE WATERS FARTHER NORTH LATER THIS AFTN.
VISIBILITIES IN THE SNOW SHOWERS WILL LIKELY DROP TO LESS THAN ONE
MILE FOR A TIME. RADAR IMAGERY AROUND 15Z SHOWS SNOW SHOWERS ABOUT
5 MILES NORTHEAST OF WIND POINT MOVING SOUTHWEST. STILL EXPECT NORTH
TO NORTHWEST WINDS TO VEER TO THE NORTHEAST AND EAST AS WEAK CONVERGENCE
ZONE MOVES ACROSS NEAR SHORE WATERS.
MBK
&&
.PREV DISCUSSION... /ISSUED 327 AM CST SUN FEB 15 2015/
TODAY AND TONIGHT...FORECAST CONFIDENCE...HIGH
A WEAK UPPER TROUGH WILL REMAIN OVER THE NORTHERN PLAINS AS THE
UPPER FLOW OVER SOUTHERN WISCONSIN BECOMES MORE ZONAL AND THE STRONG
JET MAX MOVES OFF TO THE EAST. VERY WEAK UPPER LEVEL DIVERGENCE.
WEAK 700 MB UPWARD MOTION TODAY AND OVER THE EAST TONIGHT.
850/700 MB WARM AIR ADVECTION FOR THE MOST PART...BUT BECOMES
NEUTRAL FOR A TIME LATER THIS AFTERNOON AT 700 MB AND AT 850 MB
TONIGHT. 700 MB RH INCREASES SLOWLY FROM THE WEST TODAY...REACHING
THE EAST THIS EVENING. 850 MB RH REMAINS DRY. THE 925 MB RH
INCREASES AS THE LOW LEVEL FLOW BECOMES MORE EAST...BRINGING LAKE
MOISTURE INTO SOUTHEAST WISCONSIN THIS AFTERNOON AND INTO SOUTH
CENTRAL WISCONSIN DURING THE EVENING. MESO MODELS BRING SOME LIGHT
QPF MAINLY JUST INLAND NEAR LAKE MICHIGAN. HOWEVER THE SIMULATED
RADAR REFLECTIVITY SPREADS RETURNS...FLURRIES...FARTHER INLAND WITH
THE INCREASING 925 MB MOISTURE. ANY ACCUMULATIONS WILL BE LIMITED
TO THE LAKESHORE AREAS. RATHER STEEP LAPSE RATES WITH NEAR
SATURATION ON THE NAM SOUNDINGS AT MILWAUKEE THIS AFTERNOON REACHING
4 THSD FT. ACCUMULATIONS SHOULD BE UNDER AN INCH.
WIND CHILLS ARE STILL NEAR OR IN THE LOW END OF THE ADVISORY
CRITERIA. OVER SOUTH CENTRAL WISCONSIN WINDS HAVE DECOUPLED IN MANY
AREAS AS THE RIDGE BUILDS IN. WINDS CHILLS THERE ARE MAINLY AROUND
18 BELOW. WILL KEEP ADVISORY FOR NOW AS TEMPERATURES WILL CONTINUE
TO DROP AND WINDS MAY PICK UP A BIT JUST AFTER SUNRISE. HOWEVER
THERE ARE A FEW MID/HIGH LEVEL CLOUDS OVER PORTIONS OF THE WEST
WHICH WILL AFFECT THE TEMPERATURE DROP. MAY END UP CANCELING
ADVISORY IN THAT AREA EARLY.
MONDAY THROUGH THURSDAY...FORECAST CONFIDENCE...MEDIUM
A COUPLE OF WEAK SHORTWAVES MAY BRING SOME LIGHT SNOW OR FLURRIES
AT TIMES MONDAY THROUGH TUESDAY NIGHT. ACCUMULATIONS SHOULD BE A
DUSTING TO A COUPLE TENTHS OF AN INCH AT BEST.
HIGH PRESSURE TO THE WEST WEDNESDAY AND OVERHEAD THURSDAY WILL
BRING DRY WEATHER TO SOUTHERN WISCONSIN.
BELOW NORMAL TEMPERATURES WILL PERSIST THROUGH MID-
WEEK...WITH PARTICULARLY CHILLY CONDITIONS AGAIN WEDNESDAY AND
THURSDAY. WILL PROBABLY SEE WIND CHILLS HIT ADVISORY LEVELS AGAIN
AT TIMES.
FRIDAY AND SATURDAY...FORECAST CONFIDENCE...MEDIUM
ANOTHER WEAK WAVE OR TWO MAY BRING SOME MORE LIGHT SNOW CHANCES
FRIDAY INTO SATURDAY. AMOUNTS LOOK VERY LIGHT ONCE AGAIN. TEMPS AT
LEAST LOOK A LITTLE MILDER FOR THE END OF THE WEEK...THOUGH LIKELY
REMAINING BELOW NORMAL.
AVIATION/12Z TAFS/...
HIGH RESOLUTION MESO MODELS SHOWING A POTENTIAL FOR LAKE-EFFECT SNOW
SHOWERS AFTER 15Z BRUSHING WIND POINT...AND CLIPPING KMKE AND KENW
BEFORE MOVING INLAND AS WINDS TURN ONSHORE WITH CORE OF HIGH
PRESSURE PASSING TO THE EAST. LAKE EFFECT SNOW WOULD BE LIGHT...
ALTHOUGH SOME AREAS IN THE COUNTIES BORDERING LAKE MICHIGAN MAY GET
SOME ACCUMULATIONS...BUT ARE EXPECTED TO BE LESS THAN AN INCH.
THIS WOULD PRODUCE MAINLY MVFR CIGS/VSBYS OVER THE SOUTHEAST...WITH
CEILINGS AROUND 3 THSD FT PUSHING INLAND TOWARD SOUTH CENTRAL
WISCONSIN LATER THIS AFTERNOON AND EVENING. THERE COULD BE A BRIEF
PERIOD OF IFR VSBYS IN THE LAKE SNOW CLOSE TO THE LAKE. ELSEWHERE A
SLOW PROGRESSION OF MID CLOUDS FROM THE WEST TODAY.
MARINE...
WINDS WILL CONTINUE TO LOWER AS GRADIENT RELAXES WITH HIGH BUILDING
OVER REGION.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...99
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
MONDAY THROUGH SATURDAY...DDV
AREA FORECAST DISCUSSION
NWS TUCSON AZ
1015 AM MST SUN FEB 15 2015
.SYNOPSIS...EXPECT ISOLATED TO SCATTERED SHOWERS THROUGH MONDAY
EVENING. THE BEST CHANCE FOR HEAVIER RAINFALL WILL BE SOUTH TO
SOUTHEAST OF TUCSON. THEREAFTER...DRY CONDITIONS WITH ABOVE NORMAL
DAYTIME TEMPERATURES WILL OCCUR TUESDAY THROUGH SATURDAY.
&&
.DISCUSSION...KEMX WSR-88D DETECTED ISOLATED TO SCATTERED 30-45 DBZ
ECHOES THAT EXTENDED FROM THE TUCSON METRO AREA WWD/NWWD INTO WRN
PIMA COUNTY AND SOUTH CENTRAL PINAL COUNTY AT 1710Z. OTHER STRONGER
CELLS WERE BEING DETECTED JUST SOUTH OF THIS FORECAST AREA ACROSS
NRN SONORA. MEASURED RAINFALL AMOUNTS HAVE BEEN LESS THAN ONE TENTH
OF AN INCH. OTHERWISE...MOSTLY CLOUDY TO CLOUDY SKIES AND LIGHT
WINDS WERE THE RULE ACROSS SE AZ AT THIS TIME.
DEWPOINTS AT LOWER ELEVATIONS VALID 16Z RANGED FROM THE LOWER
40S-LOWER 50S F...AND THESE TEMPS WERE ABOUT 10-15 DEGS F HIGHER
VERSUS 24 HOURS AGO. 15/12Z KTWC SOUNDING TOTAL PRECIP WATER VALUE
WAS 0.93 INCH. THIS VALUE WAS THE 12TH HIGHEST ON RECORD FOR
FEBRUARY...AND IS GREATER THAN 3 STANDARD DEVIATIONS ABOVE NORMAL.
15/12Z UPPER AIR PLOTS DEPICTED 566 DM LOW PRESSURE CENTERED JUST SW
OF THE BAJA CALIFORNIA SPUR...AND A HIGH PRESSURE RIDGE WAS JUST OFF
OF THE WEST COAST ESSENTIALLY ADJACENT 130W. LIGHT TO MODERATE
SLY/SWLY FLOW PREVAILED ABOVE 700 MB.
THE UPPER LOW WILL REMAIN QUASI-STATIONARY TODAY...THEN WILL MOVE
GENERALLY EWD AND WEAKEN ACROSS SONORA ON MON. 15/14Z RUC HRRR
SUGGESTS THAT SHOWERS PRODUCING LIGHT RAINFALL WILL CONTINUE WEST-
TO-NORTHWEST OF TUCSON INTO EARLY THIS AFTERNOON. STRONGER PRECIP
ECHOES ARE DEPICTED TO DEVELOP ACROSS SANTA CRUZ/SRN COCHISE
COUNTIES. THIS AREA IS COINCIDENT WITH THE 15/12Z NAM/GFS SOLUTIONS
THAT DEPICT FAIRLY SUBSTANTIAL QPF/S TO OCCUR NEAR THE INTERNATIONAL
BORDER SOUTH-TO-SOUTHEAST OF TUCSON.
THEREAFTER...15/12Z NAM/GFS INDICATE THAT PRECIP CHANCES WILL
DECREASE MARKEDLY MON AS FLOW ALOFT BECOMES INCREASINGLY NWLY IN
RESPONSE TO UPPER RIDGE AMPLIFICATION NEAR THE WEST COAST. HAVE
NOTED THAT THE 15/00Z ECMWF DEPICTED LIGHT QPF/S NE OF TUCSON MON
NIGHT...LIKELY IN RESPONSE TO AN IMPULSE EMBEDDED WITHIN STRONGER
NWLY FLOW ALOFT. MEANWHILE...THE 15/12Z GFS DEPICTED DRY CONDITIONS
AREA-WIDE MON NIGHT.
AT ANY RATE...THE OFFICIAL FORECAST DEPICTS ISOLATED TO SCATTERED
SHOWERS THRU TONIGHT...WITH THE BEST CHANCE OF ANY RAINFALL OF
SIGNIFICANCE TO BE SOUTH-TO-SOUTHEAST OF TUCSON. GIVEN THAT
LIGHTNING STRIKES HAVE BEEN DETECTED ACROSS CENTRAL SONORA AND THE
VERY MODEST INSTABILITY VIA THE 15/12Z KTWC SOUNDING...THERE IS ALSO
A SLIGHT CHANCE OF THUNDERSTORMS THIS AFTERNOON/EVENING MAINLY NEAR
THE INTERNATIONAL BORDER GENERALLY FROM NOGALES TO DOUGLAS. A CHANCE
OF SHOWERS CONTINUES MON AGAIN MAINLY SOUTH-TO-SOUTHEAST OF TUCSON.
A SLIGHT CHANCE OF SHOWERS OCCURS ELSEWHERE MON.
GIVEN THE AFOREMENTIONED DISTURBANCE IN NWLY FLOW ALOFT...THERE IS A
SLIGHT CHANCE OF SHOWERS EAST-TO-SOUTH OF TUCSON MON EVENING. A FEW
LINGERING SHOWERS MAY OCCUR NEAR THE NEW MEXICO BORDER LATE MON
NIGHT. THEREAFTER...DRY CONDITIONS WILL OCCUR TUE-SAT AS HIGH
PRESSURE ALOFT PREVAILS NEAR THE WEST COAST.
HIGH TEMPS THIS WEEK WILL MOSTLY AVERAGE ABOUT 4-12 DEGS F ABOVE
NORMAL. THE COOLEST DAY FOR MOST LOCALES WILL BE TUE.
&&
.AVIATION...VALID THRU 16/18Z.
ISOLATED TO SCATTERED SHOWERS WILL OCCUR INTO MONDAY MORNING. THERE
IS ALSO A SLIGHT CHANCE OF -TSRA SOUTH-TO-SOUTHEAST OF KTUS THIS
AFTERNOON AND THIS EVENING. OTHERWISE...CLOUD DECKS WILL GENERALLY
RANGE FROM 5K-9K FT AGL. SURFACE WIND INTO MONDAY MORNING WILL
MAINLY BE LESS THAN 10 KTS. HOWEVER...NWLY SURFACE WIND AT 12-18 KTS
WITH GUSTS TO 25 KTS WILL OCCUR NE OF KTUS AND ESPECIALLY IN THE
VICINITY OF KSAD THIS AFTERNOON. AVIATION DISCUSSION NOT UPDATED FOR
TAF AMENDMENTS.
&&
.FIRE WEATHER...EXPECT ISOLATED TO SCATTERED SHOWERS THROUGH MONDAY
EVENING. THERE IS ALSO A SLIGHT CHANCE OF THUNDERSTORMS THIS
AFTERNOON AND EVENING...AND AGAIN MONDAY AFTERNOON AND EVENING...
SOUTH TO SOUTHEAST OF TUCSON. DRY CONDITIONS WILL THEN PREVAIL
TUESDAY THROUGH SATURDAY. EXPECT NORMAL DIURNAL WIND TRENDS ACROSS
MUCH OF THE AREA DURING MUCH OF THIS WEEK. HOWEVER...GUSTY NORTHWEST
WINDS WILL OCCUR THIS AFTERNOON AND MONDAY AFTERNOON ACROSS THE GILA
RIVER VALLEY.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
FRANCIS
AREA FORECAST DISCUSSION
NWS DULUTH MN
1208 PM CST SUN FEB 15 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 336 AM CST SUN FEB 15 2015
AN ARCTIC HIGH PRESSURE DESCENDING INTO THE UPPER GREAT LAKES TODAY
WILL BE FOLLOWED BY A WEAK CLIPPER SYSTEM WHICH WILL BRING A CHANCE
FOR LIGHT SNOWFALL ACCUMULATIONS TODAY/TONIGHT. PRIMARY CONCERN FOR
THE SHORT TERM IS TIMING AND INTENSITY OF SNOWFALL AS A RESULT OF
THIS CLIPPER SYSTEM TODAY. ANOTHER CONCERN OF A MUCH SMALLER SPATIAL
SCALE IS CONVERGENCE OVER LAKE SUPERIOR RESULTING IN LAKE EFFECT
SNOW SHOWERS POSSIBLY AFFECTING THE NORTH AND/OR SOUTH SHORE NEAR
THE TWIN PORTS. TEMPERATURES WARM UP BRIEFLY MONDAY AS LOW/MID LEVEL
WINDS BECOME OUT OF THE SOUTHWEST LATE SUNDAY INTO MONDAY.
EARLY THIS MORNING...WEAK CONVERGENCE OVER LAKE SUPERIOR WEST OF A
LINE FROM SILVER BAY TO THE BAYFIELD PENINSULA POSSIBLY MAY LEAD TO
LAKE EFFECT SNOW SHOWER DEVELOPMENT. THIS IS EVIDENT ON RADAR AS
WEAK ECHOES AS WELL AS AN INTERMITTENT 2KFT CEILING DEVELOPING AT
SUPERIOR AIRPORT AND DULUTH SKY HARBOR. MOST SHORT-RANGE GUIDANCE IS
NOT PICKING UP ON THIS WITH THE EXCEPTION OF THE 00Z GEM-REGIONAL.
NO SURFACE REPORTS OF SNOWFALL AS OF 09Z /3 AM CST/ THIS
MORNING...WITH THE EXCEPTION OF ASHLAND WHERE FAVORABLE LAKE EFFECT
CONDITIONS HAVE EXISTED FOR A LONGER PERIOD OF TIME DUE TO A VERY
LIGHT BUT PERSISTENT NORTHEASTERLY WIND. WORKING AGAINST LAKE
EFFECT SNOW SHOWERS IS LESS THAN OPTIMAL MOISTURE AT LOW LEVELS AND
SOME WEAK DIRECTIONAL SHEAR AT LOW LEVELS PREVENTING A PERSISTENT
BAND FROM DEVELOPING. OPTED TO INCLUDE SOME ISO/SCT SNOW SHOWER
WORDING IN EARLY THIS MORNING...AND WILL CONTINUE TO MONITOR AND
UPDATE AS RADAR/OBS WARRANT. OTHERWISE...TEMPERATURES APPEAR ON
TRACK WITH PORTIONS OF BORDERLAND /SUCH AS INL/ NOT DIPPING AS LOW
AS ORIGINALLY EXPECTED DUE TO HIGH LEVEL CLOUD COVER.
TODAY...PRIMARY CONCERN IS A CLIPPER SYSTEM WHICH WILL BRING A BRIEF
PERIOD OF LIGHT SNOW SHOWERS. INCREASED POPS SLIGHTLY WHILE
ATTEMPTING TO CAPTURE THE FACT THAT INITIALLY THIS AFTERNOON THE
DURATION OF SNOWFALL WILL BE JUST A FEW HOURS. SNOW AMOUNTS WILL BE
A COATING TO AN INCH AT MOST...AND CURRENT SNOWFALL FORECAST MAY BE
ON THE HIGH SIDE...BUT AM COUNTING ON A HIGH SNOW RATIO /AROUND 20
TO 1/ SIMILAR TO FRIDAY MORNING IN THE TWIN PORTS AREA. A LITTLE
CONCERNED THAT THE HRRR/HIRES ARW ARE DIMINISHING THE LARGE-SCALE
LIFT AS THE CLIPPER MOVES TOWARDS THE WESTERN EDGE OF THE CWA THIS
MORNING...BUT 00Z AND 06Z NAM/NAM 4KM CONUS NEST/HIRES NMM AND
LATEST FEW RUNS OF RAP ARE MORE SUPPORTIVE OF CURRENT FORECAST. LOW
LEVEL LAPSE RATES WILL SUPPORT MIXING TO AROUND 900MB AT TIMES THIS
AFTERNOON...AND WHILE LOW LEVEL WINDS ARE NOT VERY STRONG COULD SEE
A FEW GUSTS IN THE 15-20KT RANGE DURING AND FOLLOWING SNOW SHOWERS
TODAY. TEMPERATURES RISING TO THE SINGLE DIGITS ABOVE ZERO IN MOST
LOCATIONS.
TONIGHT...SNOW SHOWERS END IN MOST LOCATIONS AS WEAK MID-LEVEL
RIDGING DEVELOPS OVER SOUTHERN ONTARIO TOWARDS MORNING. FOLLOWING
THE MAIN CLIPPER A SECONDARY 925/850MB TROUGH WILL MOVE THROUGH
CENTRAL MINNESOTA AND NORTHWEST WISCONSIN...AND WITH LOW LEVEL
MOISTURE ALREADY IN PLACE COULD SEE FLURRIES/LIGHT SNOW DEVELOPING.
UNLIKE PREVIOUS FEW EVENTS THERE TEMPS THROUGH THE COLUMN WILL BE
EITHER WITHIN OR COLDER THAN THE DENDRITIC GROWTH ZONE...SO FREEZING
DRIZZLE WILL NOT BE A CONCERN. TEMPERATURES FALLING TO NEAR TO
SINGLE DIGITS BELOW ZERO...WITH USUAL COLD SPOTS IN THE ARROWHEAD
REGION OF MINNESOTA DROPPING INTO THE MID-TEENS BELOW ZERO. MOST
GUIDANCE IS COLDER FOR THE LOW TEMPS...BUT SINCE CLOUDS WILL REMAIN
IN PLACE ALL NIGHT AND LOW LEVEL WINDS HAVE A SOUTHERLY COMPONENT
DECIDED TO GO A BIT WARMER THAN MODEL CONSENSUS.
MONDAY....WINDS TURN OUT OF THE WEST/NORTHWEST AND PRESSURE GRADIENT
OVER MINNESOTA INCREASES AS YET ANOTHER ARCTIC HIGH PRESSURE
DESCENDS FROM THE CANADIAN PRAIRIE TOWARDS THE NORTHERN HIGH
PLAINS. WINDS MAY BECOME BREEZY IN THE AFTERNOON...GUSTING TO
AROUND 20KTS AT TIMES. A LOW/MID LEVEL CLOUD DECK WILL STICK
AROUND MOST OF THE DAY...AND STEEP LOW LEVEL LAPSE RATES COULD
LEAD TO A FEW SNOW SHOWERS OR FLURRIES THROUGHOUT THE DAY DESPITE
A LACK OF GREAT LARGE-SCALE LIFT /BUT ABSENCE OF OVERWHELMING
LARGE-SCALE SUBSIDENCE/. TEMPS WARMER...RISING TO THE LOW TO MID
TEENS...AND EVEN NEAR 20 ALONG THE INTERSTATE 35 CORRIDOR.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 336 AM CST SUN FEB 15 2015
AN UPPER LOW ANCHORED NEAR HUDSON BAY WILL REMAIN NEARLY STATIONARY
FROM MONDAY NIGHT THROUGH FRIDAY. AT THE SFC...THIS TRANSLATES INTO
ARCTIC HIGH PRESSURE DRIFTING OVER THE FORECAST AREA FROM MANITOBA
MONDAY NIGHT THROUGH THURSDAY. COLD...DRY AIR WILL BE LOCKED IN
PLACE DURING THIS TIME. A NW FLOW WILL BE OVER THE FORECAST AREA AS
WELL AS OVER LAKE SUPERIOR. LAKE EFFECT SNOW SHOWERS WILL OCCUR
REGULARLY OVER THE GOGEBIC RANGE OF NE ASHLAND AND NORTHERN IRON
COUNTIES MONDAY NIGHT THROUGH THURSDAY. SNOW AMOUNTS WILL BE LIMITED
HOWEVER AS THIS TYPE OF AIRMASS WILL INDUCE ICE FORMATION ON LAKE
SUPERIOR AND WILL LIMIT THE ACCUMULATION POTENTIAL.
REGARDLESS...WILL HAVE SOME POPS THROUGH THIS PERIOD...EVEN INTO
SOUTHERN ASHLAND AND IRON COUNTIES. EACH NIGHT WILL HAVE THE
CAPABILITY OF LOW WIND CHILL VALUES...BUT WILL SAVE THE HEADLINES
FOR A LATER TIME AS THE SFC WIND DECOUPLES EACH NIGHT. FRIDAY AND
FRIDAY NIGHT WILL BE AFFECTED BY A CLOSED LOW PUSHING A SFC LOW
THROUGH THE FORECAST AREA. SOME LIGHT ACCUMULATIONS ARE ANTICIPATED.
SATURDAY FINDS THE RETURN OF ARCTIC HIGH PRESSURE TO THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1205 PM CST SUN FEB 15 2015
A SHORTWAVE WILL MOVE THROUGH THE NORTHLAND THROUGHOUT THE TAF
PERIOD...BRINGING A CHANGE FROM MOSTLY VFR CONDITIONS TO MVFR
CIGS/VSBYS. SOME LIGHT SNOW HAS BEEN ASSOCIATED WITH THIS FEATURE
OVER NORTH CENTRAL AND NORTHWESTERN MN...AND WE SHOULD SEE THIS
LIGHT SNOW MOVE TO THE EAST AS THE DAY WEARS ON. THE SNOW WILL
LARGELY MOVE OUT TONIGHT...BUT LOW CLOUDS...GENERALLY MVFR WILL BE
FOUND IN THE WAKE OF THE SYSTEM.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 0 16 -9 3 / 40 10 0 10
INL -12 10 -17 1 / 10 10 0 20
BRD 4 16 -7 4 / 20 10 0 10
HYR 1 15 -6 4 / 30 20 0 10
ASX 1 15 -3 4 / 30 20 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...JJM
LONG TERM...GSF
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
302 PM CST Sun Feb 15 2015
.SHORT TERM: (Tonight through Monday Night)
Issued at 255 PM CST Sun Feb 15 2015
All data continues to show a winter storm impacting the area tonight
into Sunday, and the 12z model guidance generally is close to the
previous 00z/06z runs adding to the event confidence. That said
there is still significant uncertainty on aspects of the forecast,
namely where the frontogenetical band will set-up and the snow it
will produce before 06z, and the northern edge of snow thereafter.
The overall scenario has changed little since the previous forecast.
Radar currently shows that the initial snow band is trying to
develop from near KSTJ-KMBY-KSET-KSLO in response to strong mid
level frontogenetical forcing and weak warm advection. I have not
seen any snow reports thus far so we are still in the saturation
process due to dry antecedant low levels. Fronotogenetical forcing
and low level warm advection will ramp-up through the remainder of
this afternoon and especially this evening and the expectation is
that this evolving band will intensify producing moderate snowfall
between the 00-06z period. A blend of available short-term
guidance from the RAP, HRRR and deterministic guidance suggests
the band will become established just north of I-70 and become
more west-east oriented producing ~3 inches by 06z.
After 06z conditions begin to change due to the short-wave digging
southeastward into the central Plains. The response appears to be a
southward shift in the mid level frontogenesis and warm advection
supporting this northern band, and increasing large scale ascent
with a vort max head of trof and the backbuilding ULJ. Thus after
06z the primary forcing and ascent shifts southward along and south
of I-70. This would suggest that the northern snow band will fade
while a new and much larger swath of snow spreads/develops across
the southern half of MO/IL. This will place the I-70 corridor on the
northern part of the snow shield and could play havoc with amounts
along the I-70 corridor where the greatest uncertainty in the
forecast resides. Large scale ascent with the migrating short wave
trof and mid level frontogenesis will keep the heart of the snow band
focused south of I-70 across southern MO and southern IL on Sunday
morning with Columbia-St. Louis-Vandalia IL still on the northern
periphery of the deformation snow shield. By mid-late afternoon the
forcing will exit to the east of the area in association with the
migrating short wave trof, bringing and end to the snowfall.
Despite the very cold temperatures and dry nature of the snow, the
sounding profiles continue to show a shallow dendritic growth zone
with much larger profiles supporting columns and plates within the
lift zone. This suggests snow ratios closer to 13-15:1.
The new forecast is not far from the previous one but is a bit lower
in snow totals along I-70 with 5-7 inches due to the uncertainties
discussed, but still looking at 8+ southeast MO into southern IL.
This forecast will need to be further refined this evening in
anticipation of the northern frontogenetic snow band.
No changes needed to the previously issued winter storm watch and
advisories.
Glass
.LONG TERM: (Tuesday through Next Sunday)
Issued at 255 PM CST Sun Feb 15 2015
A cold front wil move southeastward through our forecast area on
Tuesday as a broad positively tilted upper level trough gradually
deepens over the region. There may be some post fronal light snow
Tuesday and Tuesday night, mainly across central and southeast MO
and southwest IL. A secondary cold front will drop southeastward
through our area late Tuesday night and Wednesday morning. Very
cold air is expected to invade our forecast area behind this second
front as a strong surface ridge bulds southeastward into MO from the
northern Plains. The models drop the -24 degree C 850 mb isotherm
southward to near STL on Wednesday. Temperatures on Wednesday and
Wednesday night should be close to 30 degrees below normal due to
this very cold air mass along with snow cover across most of the
forecast area from the recent winter storm. A warming trend should
begin Thursday night due to rising upper level heights along with
surface winds becoming southerly as the surface ridge shifts east of
our area. There may be some light snow Thursday night and Friday,
mainly across southeast MO and southwest IL, due to low-mid level
warm air advection. There will be a better chance of more
significant precipitation Friday night through Sunday as a cold
front sags southward into the area and a southern stream shortwave
approaches. Precipitation type will be in question along and ahead
of the cold front, but should be all snow by Saturday night or
Sunday as another cold air mass drops southward through our area
behind the front.
GKS
&&
.AVIATION: (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1037 AM CST Sun Feb 15 2015
A band of snow is expected to develop later this afternoon from
COU to the St Louis metro area well ahead of an approaching storm
system. The cloud ceiling and visibilities will gradually fall as
the lower levels of the atmosphere saturate and the snow begins.
The cloud ceiling will fall below 1000 feet while the visibility
falls below 1SM as the snowfall becomes heavier this evening. The
snow will be lighter further north in UIN. The snow will continue
Monday morning, but should be of lighter intensity as the surface
low passes well to our south. E-nely surface winds will continue
through the period with the surface ridge centered over the Great
Lakes and Ohio Valley regions, while a surface low moves eastward
through the Southern Plains and Gulf Coast states.
Specifics for KSTL: The cloud ceiling will gradually lower this
afernoon and this evening with light snow beginning late this
afternoon or early this evening, then becoming heavier later this
evening with ceilings dropping below 1000 feet and visibilities
below 1SM. The snow will become lighter by early morning and
eventually come to an end Monday afternoon with the ceiling
possibly rising into the VFR catagory by the end of the taf
forcast period.
GKS
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 16 23 15 26 / 100 80 5 10
Quincy 14 23 12 21 / 50 10 5 10
Columbia 15 25 12 26 / 100 60 5 20
Jefferson City 16 26 13 28 / 100 70 5 20
Salem 15 21 14 25 / 90 90 10 10
Farmington 17 23 12 30 / 100 100 5 20
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...WINTER STORM WARNING until 6 PM CST Monday FOR Boone MO-Callaway
MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-Iron MO-
Jefferson MO-Madison MO-Moniteau MO-Montgomery MO-Osage MO-
Reynolds MO-St. Charles MO-St. Francois MO-St. Louis City
MO-St. Louis MO-Ste. Genevieve MO-Warren MO-Washington MO.
WINTER WEATHER ADVISORY until 6 PM CST Monday FOR Audrain MO-
Lincoln MO-Monroe MO-Pike MO-Ralls MO.
IL...WINTER STORM WARNING until 6 PM CST Monday FOR Bond IL-Clinton
IL-Fayette IL-Madison IL-Marion IL-Monroe IL-Randolph IL-
St. Clair IL-Washington IL.
WINTER WEATHER ADVISORY until 6 PM CST Monday FOR Calhoun IL-
Greene IL-Jersey IL-Macoupin IL-Montgomery IL-Pike IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
243 PM MST SUN FEB 15 2015
.SHORT TERM...VALID FOR MON AND TUE...
THE SHORT TERM LOOKS IN GOOD SHAPE. HAVE NOT MADE MANY CHANGES.
DID REDUCE QPF OVER THE MOUNTAINS SLIGHTLY AND THUS REDUCED THE
SHOW FALL MAYBE AN INCH. MODELS WERE SHOWING SLIGHTLY LOWER
AMOUNTS. AM CONTINUING THE ADVISORIES FOR THE FOOTHILLS AND
BIGHORNS. WHILE THE HRRR SHOWS SOME GOOD BANDS OF HIGHER
PRECIP...THE CURRENT ADVISORY LOOKS GOOD. THE ONE EXCEPTION IS
THE PARADISE VALLEY. HOWEVER...LATEST RUNS KEEP IT JUST EAST IN
THE BEARTOOTHS. WILL CONTINUE TO MONITOR. ALSO POSSIBLE THAT A
CONVECTIVE BAND COULD PRODUCE HIGHER AMOUNTS NEARING WARNING
CRITERIA...BUT AGAIN THE UNCERTAINTY DOES NOT WARRANT ANYTHING AT
THE MOMENT.
GOING INTO TOMORROW...A NORTH SOUTH ORIENTED JET WILL SHIFT
EAST...BISECTING THE AREA. THIS WILL PUT THE EASTERN ZONES IN THE
MORE FAVORABLE LEFT EXIT REGION. WITH THIS INCREASED LIFT...RAISED
POPS SLIGHTLY. PRECIP REMAINS FAIRLY LIGHT SO SNOW TOTALS ARE ONLY
A COUPLE OF INCHES...THOUGH THE BIGHORN MOUNTAINS COULD STILL SEE
UP TO 4 MORE INCHES.
AS FOR TEMPERATURES...NOT MUCH HAS CHANGED. OVERNIGHT MONDAY AND
TUESDAY THE EASTERN PLAINS WILL STILL LIKELY SEE TEMPERATURES DROP
INTO THE SINGLE DIGITS. REIMER
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
THE PERSISTENT NORTHWEST FLOW WILL CONTINUE TO DOMINATE THE
WEATHER PATTERN INTO NEXT WEEKEND. OUR REGION OF THE NORTHERN
ROCKIES WILL CONTINUE TO BE THE BATTLE GROUND BETWEEN THE TROUGH
AND COLD AIRMASS TO OUR EAST AND RIDGE/WARM CONDITIONS TO OUR
WEST. THIS WILL KEEP THE REGION UNSETTLED...BUT NO HIGH IMPACT
EVENTS ANTICIPATED.
WED/THU WILL SEE ANOTHER ROUND OF WARMER AND DRIER CONDITIONS
SHIFT EAST. THERE COULD BE SOME LIGHT WARM AIR ADVECTION PRECIP
INTO EASTERN MONTANA WEDNESDAY AS THE COLDEST AIR RETREATS.
SIGNIFICANT TEMPERATURE DIFFERENCES COULD BE NOTED FROM CENTRAL TO
EASTERN AREAS WHERE THE COLD AIR TRIES TO HANG ON THE LONGEST. THE
NEXT WAVE OF ENERGY DROPS SOUTHEAST ACROSS THE AREA FRIDAY. THIS
WILL SHIFT THE COLD AND UNSETTLED WEATHER BACK INTO THE REGION
BEGINNING FRIDAY AND LINGERING INTO SUNDAY. LIGHT SNOW OR AT
TIMES A RAIN/SNOW MIX WILL OCCUR FROM FRIDAY THROUGH SUNDAY.
FRIEDERS
&&
.AVIATION...
AN UNSTABLE NORTHWEST FLOW WILL BRING PERIODS OF SNOW SHOWERS
ACROSS THE REGION INTO MONDAY WITH A RAIN/SNOW MIX IN THE LOWER
ELEVATIONS. EXPECT RAPIDLY CHANGING FLIGHT CONDITIONS WITH THESE
SHOWERS FROM VFR TO IFR IN SHORT PERIODS OF TIME. MORE WIDESPREAD
IFR CONDITIONS ARE LIKELY IN AND NEAR THE MOUNTAINS...INCLUDING
KSHR AND KLVM. MOUNTAINS WILL BE MOSTLY OBSCURED OVER THE NEXT 24
HOURS. FRIEDERS
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 026/038 023/037 024/043 028/054 033/046 027/038 022/039
53/J 31/B 11/B 01/B 23/W 33/S 22/S
LVM 023/036 020/040 027/053 035/053 034/048 028/040 023/040
74/J 21/B 00/N 01/N 23/W 33/O 22/O
HDN 025/038 021/035 019/041 026/052 028/046 023/036 018/039
46/J 52/J 11/E 01/B 23/W 33/S 22/S
MLS 023/033 012/024 010/034 020/045 025/040 019/031 015/035
39/J 51/B 12/J 01/B 22/W 22/S 22/S
4BQ 023/035 016/028 013/034 022/048 026/042 022/033 017/038
47/J 62/J 12/W 01/B 12/W 32/S 22/S
BHK 021/029 005/017 002/024 013/040 022/036 015/027 011/032
39/J 51/N 11/E 01/B 22/J 22/S 22/S
SHR 022/033 019/031 017/040 023/051 026/044 022/034 016/036
66/J 63/J 12/J 00/B 23/W 43/S 22/S
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 AM MST MONDAY FOR
ZONES 41-56-66.
WY...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 AM MST TUESDAY FOR
ZONE 98.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1126 AM CST SUN FEB 15 2015
.UPDATE...
ISSUED AT 1125 AM CST SUN FEB 15 2015
MAIN CONCERNS ARE WHETHER OR NOT A BAND OF SNOW WILL SETUP AND IF
IT WILL BE NORTH OF THE NEBRASKA/KANSAS BORDER LATE THIS AFTERNOON.
RECENT RUNS OF THE RAP AND HRRR KEEP MOST OF THIS OUT OF OUR AREA.
WILL TEND TO FOLLOW THAT THINKING...BUT KEPT SOME LOW POPS ALONG
THE BORDER FOR NOW. 09Z SREF MEAN...12Z NAM AND 12Z GFS HAVE MAIN
BAND OF SNOW OVER KANSAS AND MISSOURI BUT SOME LIGHT AMOUNTS IN
OUR FAR SOUTHERN ZONES.
A BROAD AREA OF HEIGHT FALLS AT 500 MB WILL BE MOVING SOUTHEAST
THROUGH THE REGION. KOAX SOUNDING FROM 12Z SHOWED A VERY DRY LAYER
CENTERED AROUND 850 MB...WHICH WILL TEND TO LIMIT PCPN. CLOUDS
WILL HOLD MOST OF THE AFTERNOON WITH TEMPERATURES NOT RISING MUCH.
GRIDS AND TEXT PRODUCTS WERE UPDATED EARLIER...WILL CONTINUE TO
TWEAK GRIDS THE NEXT SEVERAL HOURS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 255 AM CST SUN FEB 15 2015
UPPER AIR ANALYSIS/WATER VAPOR IMAGERY REVEALED TWO DISTINCT
CLIPPERS EARLY THIS MORNING. ONE MOVING THROUGH NORTH DAKOTA WHICH
WILL STAY WELL NORTH OF THE REGION AND NOT AFFECT US AS PREVIOUSLY
EXPECTED. THE SECOND CLIPPER WAS MOVING INTO WESTERN WYOMING AND
WILL SPREAD ONTO THE PLAINS THIS AFTERNOON AND EVENING. AN AREA OF
ENHANCEMENT ON THE WATER VAPOR EXTENDING FROM COLORADO THROUGH THE
KS/NE BORDER AREA THROUGH MISSOURI APPEARS TO BE THE PRIME SPOT
FOR SNOW DEVELOPMENT LATE THIS AFTERNOON. MODELS ARE NOW PICKING
UP ON THIS...WITH SUBSTANTIAL PRECIP DEVELOPMENT JUST SOUTH OF THE
FORECAST AREA TONIGHT. THUS HAVE REALIGNED POPS A BIT...WITH A FEW
FLURRIES POSSIBLE ALONG/SOUTH OF I80 THIS AFTERNOON...WITH
MEASURABLE SNOW POSSIBLE FURTHER SOUTH INTO SOUTHEAST NEBRASKA.
ANY SNOW THAT DOES DEVELOP WOULD LIKELY BE SOUTH ACROSS KS/MO
OVERNIGHT. STILL COLD TODAY WITH HIGHS IN THE TEENS AND 20S...AND
LOW 30S ACROSS NORTHEAST NEBRASKA.
A WEAK DOWNSLOPING TROUGH SHOULD SWITCH WINDS TO THE NORTHWEST ON
MONDAY...WHICH WILL HELP BOOST TEMPS INTO THE MID TO UPPER 30S
WITH DRY CONDITIONS.
THE NEXT COLD FRONT ARRIVES MONDAY NIGHT. MODELS TO VARYING
DEGREES ARE STILL SUGGESTING AT LEAST A CHANCE OF FLURRIES AS THE
COLDER AIR ARRIVES. COULD EVEN SEE A SMALL CHANCE OF MEASURABLE
SNOW AS DEPICTED BY NAM/GFS...BUT WILL WAIT FOR ANOTHER SET OF MODEL
RUN BEFORE ADDING POPS.
BACK TO COLDER TEMPS FOR TUESDAY WITH HIGHS MOSTLY IN THE 20S.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 255 AM CST SUN FEB 15 2015
COLD WEATHER CONTINUES FOR WEDNESDAY WITH HIGHS AGAIN IN THE TEENS
WITH NORTHWEST FLOW ALOFT. MODELS TRY TO MODERATE A LITTLE BY
THURSDAY...BUT MAY BE TOO FAST GIVEN PERSISTENT EAST SOUTHEASTERLY
FLOW. THERE IS ALSO A VERY SUBTLE CLIPPER THAT COULD MOVE DOWN THE
MISSOURI VALLEY THURSDAY AS WELL...BUT TOO FAR OUT TO HAVE MUCH
CONFIDENCE. MODELS REALLY WARM THINGS UP BY FRIDAY BACK INTO THE
MID 30S TO LOWER 40S. BY THEN...GFS/ECMWF REALLY DIVERGE ON
SOLUTIONS...THUS NO REAL FORECAST CONFIDENCE DAY 7/8.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1125 AM CST SUN FEB 15 2015
EXPECT MAINLY VFR CONDITIONS THROUGH THE PERIOD. SOME FLURRIES
WILL BE POSSIBLE THIS AFTERNOON...WHICH COULD CAUSE TEMPORARY MVFR
CONDITIONS. SOUTHEAST WINDS WILL OCCUR INTO THIS EVENING. WINDS
WILL SHIFT TO THE NORTHWEST MONDAY MORNING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...MILLER
SHORT TERM...DEWALD
LONG TERM...DEWALD
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
135 PM EST SUN FEB 15 2015
.SYNOPSIS...
HIGH PRESSURE MOVING IN TODAY. WINTER STORM MONDAY AND MONDAY NIGHT
THEN COLD WITH SNOW SHOWERS AT TIMES FOR REMAINDER OF WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1000 AM UPDATE...
CLEANED UP THE WIND CHILL HEADLINES THIS MORNING TO REFLECT
TRENDS. ANXIOUSLY AWAITING FULL 12Z MODEL SUITE CONCERNING SYSTEM
ON MONDAY. GIVEN HOW BIG OF A N SHIFT THERE IS FROM JUST 24 HRS
AGO...NOT JUMPING THE GUN ON A WARNING UNTIL I SEE THE 12Z RUNS.
PREVIOUS DISCUSSION BELOW...
NAM AND RAP INDICATE 850MB TEMPS DOWN INTO THE -20C TO -25C RANGE
ACROSS CWA EARLY THIS MORNING. THIS COLD AIR CONTINUES TO SQUEEZE
OUT FLURRIES AND LIGHT SNOW SHOWERS VISIBLE ON RADAR AND IR
SAT...WHICH SHOULD GRADUALLY TAPER OF OVER THE NEXT 6 HOURS AS
MOISTURE CONTINUES TO LESSEN. WITH PERSISTENT REDUCED VISIBILITY
AT EKN...WILL EXTEND WINTER WEATHER ADVISORY IN
POCAHONTAS...WEBSTER AND RANDOLPH COUNTIES UNTIL 9AM/14Z...FOR
SNOW AND BLOWING SNOW.
STRUGGLING TO GET WIND CHILLS DOWN TO CRITERIA IN THE WIND CHILL
WARNING EXCEPT AT THE HIGHER ELEVATIONS. HOWEVER WITH A FEW MORE
HOURS OF COOLING...DO NOT HAVE ANY CHANGES PLANNED. HAVE ADVISORY
CRITERIA WIND CHILLS ACROSS THE NORTH AGAIN LATE TODAY AND TONIGHT
AND WILL LIKELY NEED AN ADVISORY. HOWEVER...TO AVOID CONFUSION OF
HAVING A WARNING AND ADVISORY FOR THE SAME COUNTIES WILL DEFER THE
ADVISORY TO THE DAY SHIFT. WILL ADD MENTION TO THE HWO.
POPS BEGIN INCREASING FROM THE SW LATE TONIGHT. WITH SOME SNOW
MOVING INTO SW VA AND WV COAL FIELDS BY THE END OF THE NEAR TERM
PERIOD. BULK OF THIS SYSTEM WILL BE IN SHORT TERM PERIOD...BUT DO
HAVE WINTER STORM WATCH STARTING AT 11Z ACROSS CENTRAL AND SOUTHERN
CWA.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
THE RIGHT REAR OF AN EXITING 250 MB JET MAX MONDAY MORNING COUPLED
WITH THE LEFT ENTRANCE OF A STRENGTHENING 250 MB JET MAX OVER DIXIE
MONDAY EVENING HAS HELPED MODELS DEVELOP DEEPER MOISTURE FURTHER
NORTH IN THE 00Z RUNS.
TRENDED TO FAVOR MORE THE 00Z GFS AND ECMWF OVER THE LESS ROBUST NAM
SOLUTION. A MID LEVEL DRY SLOT DOES SWEEP INTO OUR SW COUNTIES
MONDAY NIGHT. SO DURATION WILL BE LIMITED TO 12 TO 18 HRS. COLD
SURFACES AND AIR TEMPERATURES WILL ALLOW ANY SNOW TO BE SEEN FIRST
ON UNTREATED PAVEMENTS. YET...A BIT CONCERNED THAT THE COLD AIR
MASS ONLY HAS ABOUT .5 PRECIPITABLE WATER TO OUR SOUTH. WILL FLAKE
SIZE BE LIMITED...ESPECIALLY NORTH OF THE INTERSTATE 64 CORRIDOR IN
THE LOWLANDS.
BEST LIFT APPEARS TO BE FOR OUR SW VA COUNTIES ON NORTH TOWARD BKW.
WILL INCLUDE SOME HEAVY AT TIMES IN WORDING THERE.
WILL POST A WINTER STORM WATCH FOR MONDAY INTO MONDAY NIGHT...EVEN
IN SOME COUNTIES...WERE WE HAD NO MENTION OF POPS PREVIOUSLY FOR
MONDAY. WATCH MOSTLY SOUTH OF ROUTE 50 CORRIDOR IN THE OHIO
VALLEY...THEN THRU CENTRAL WV. OF COURSE...DESPITE SIMILAR
SNOWS...THE HIGHER SNOW CRITERIA IN OUR CENTRAL MOUNTAINS COUNTIES
LIMITS POSTED A WATCH THERE. WITH ALL THE CURRENT
HEADLINES...DECIDED ON 1 GENERAL GROUP FOR THE WATCH...OF COURSE THE
SNOW WILL START LATER ACROSS THE NORTHERN COUNTIES COMPARED TO THE
SOUTH.
TUESDAY SHOULD BE A LULL...BEFORE THE APPROACH OF THE NEXT ARCTIC
TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
DUE TO CONSIDERABLE DIFFERENCES BETWEEN THE OPERATIONAL
MODELS...USED A BLEND OF THE GEFS/ECMWF/AND NAEFS ENSEMBLE MEANS FOR
THE FORECAST. THE ARCTIC AIRMASS REMAINS OVER THE AREA WEDNESDAY
NIGHT AND THURSDAY...PROVIDING FOR UPSLOPE SNOW. YET ANOTHER SYSTEM
WOULD ARRIVE FRIDAY NIGHT INTO THE WEEKEND. MODELS INDICATE THAT
WARMER AIR MAY BE PULLED UP IN ADVANCE OF THIS SYSTEM.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
STILL SEEING SOME LIGHT SNOW AND BLOWING SNOW...MAINLY IN THE COAL
FIELDS AND MOUNTAINS. ACTIVITY WILL CONTINUE TO TAPER OFF THROUGH
THE NEXT SEVERAL HOURS. WINDS ARE DECREASING...HOWEVER STILL A BIT
GUSTY INTO THIS AFTERNOON. FEW TO SCT CLOUDS TODAY WILL GIVE WAY TO
THICKENING HIGHER CLOUDS MOVING IN FROM THE SOUTHWEST TONIGHT. SNOW
MOVING BACK IN FROM THE SOUTH MONDAY...ALTHOUGH SHOULD NOT IMPACT
TAF SITES UNTIL AFTER CURRENT TAF PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF SNOW ENDING IN MOUNTAINS MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EST 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY M H H H H H H H H H H H
EKN CONSISTENCY M H H H H H H H M M M M
PKB CONSISTENCY M M H H H H H H H H H H
CKB CONSISTENCY H H M H H H H H H H H M
AFTER 18Z MONDAY...
PERIODS OF IFR POSSIBLE IS SNOW MONDAY INTO MONDAY NIGHT AND AGAIN
WEDNESDAY INTO THURSDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER STORM WATCH FROM MONDAY MORNING THROUGH LATE MONDAY
NIGHT FOR WVZ005>008-013>018-024>028-033>037.
WIND CHILL WARNING UNTIL 4 PM EST THIS AFTERNOON FOR WVZ038-
046-047.
OH...WINTER STORM WATCH FROM MONDAY MORNING THROUGH LATE MONDAY
NIGHT FOR OHZ083-085>087.
KY...WINTER STORM WATCH FROM MONDAY MORNING THROUGH LATE MONDAY
NIGHT FOR KYZ101>103-105.
VA...WINTER STORM WATCH FROM MONDAY MORNING THROUGH LATE MONDAY
NIGHT FOR VAZ003-004.
&&
$$
SYNOPSIS...KTB/RPY/MZ
NEAR TERM...MZ/30
SHORT TERM...KTB
LONG TERM...RPY
AVIATION...MZ