Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/17/15
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 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 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
939 PM EST MON FEB 16 2015
.UPDATE...
A 1006 MB LOW IS CURRENTLY MOVING NORTHEAST INTO CENTRAL GEORGIA.
THE WARM FRONT HAS LIFTED WELL NORTH OF OUR AREA AND THIS IS
EVIDENCED BY THE VERY MILD TEMPERATURES IN THE LOW TO MID 60S
ACROSS THE AREA THIS EVENING UNDER A BLANKET OF MID AND HIGH
CLOUDS. THE LOW WILL CONTINUE TO MOVE NORTHEAST...REACHING THE
SOUTH CAROLINA COAST BY TUESDAY MORNING. A TRAILING COLD FRONT
WILL PUSH INTO THE AREA LATE TONIGHT AND CONTINUE SOUTH REACHING
OUR SOUTHERN ZONES EARLY TUESDAY AFTERNOON BEFORE SLOWING TO A
CRAWL. WIDESPREAD RAIN WILL ACCOMPANY THE FRONT INTO THE AREA LATE
TONIGHT AND THEN STEADILY PRESS SOUTHEAST THROUGH OUR FORECAST
AREA DURING THE DAY ON TUESDAY. THE GOING FORECAST HAS THIS ALL
HANDLED RATHER WELL AND NO MAJOR CHANGES ARE NECESSARY THIS
EVENING.
&&
.AVIATION...VFR CONDITIONS MUCH OF TONIGHT. MODELS SHOW
BAND OF RAIN MOVING OVER TAF SITES IN THE 10Z-13Z PERIOD
CIGS ARE EXPECTED TO LOWER TO LOW-END MVFR TOWARD DAWN.
LATEST HRRR GUIDANCE SUGGESTS BAND OF CIGS CLOSE TO OVC010
ASSOCIATED WITH THIS BAND OF RAIN. IFR CIGS POSSIBLE...BUT
AT THIS POINT KEEPING CIGS AT OVC010. BAND TO REMAIN
OVER TAF SITES THRU EARLY AFTERNOON...THEN ACTIVITY MAY
BECOME MORE SCATTERED IN NATURE AND LIGHTER...WITH
SOMEWHAT HIGHER CIGS.
INCREASING PRESSURE GRADIENT MAY SUPPORT SOME INCREASE IN
SOUTHWEST SFC WINDS LATER TONIGHT...PERHAPS AN OCCASIONAL
GUST TO 18-20KTS. WINDS SHIFT TO WESTERLY MIDDAY TUE...THEN
NORTHWEST LATE IN THE DAY.
&&
.MARINE...
SOUTHERLY WINDS WILL CONTINUE TO INCREASE TONIGHT...VEERING TO
THE SOUTHWEST AFTER MIDNIGHT AHEAD OF AN APPROACHING COLD FRONT.
A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE NEARSHORE WATERS AND A
GALE WARNING IS IN EFFECT FOR THE OFFSHORE WATERS TO ACCOUNT FOR
FREQUENT GUSTS TO GALE FORCE OFFSHORE OVERNIGHT THROUGH EARLY
TUESDAY MORNING. THE COLD FRONT WILL PUSH THROUGH WITH WIDESPREAD
RAIN ON TUESDAY WITH A SHARP DECREASE IN WINDS TUESDAY AFTERNOON
AS WINDS VEER TO THE NORTHWEST IN THE WAKE OF THE COLD FRONT.
RIP CURRENTS: LOW RISK EXPECTED ON TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 53 57 35 51 / 90 100 20 0
SSI 58 61 38 51 / 60 100 50 0
JAX 61 64 39 54 / 50 100 60 0
SGJ 62 68 42 54 / 30 100 70 0
GNV 61 66 39 55 / 50 100 60 0
OCF 60 69 43 57 / 30 100 70 0
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...GALE WARNING UNTIL NOON EST TUESDAY 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 NOON EST TUESDAY 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.
&&
$$
SHULER/WOLF/
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 COLUMBIA SC
826 PM EST MON FEB 16 2015
.SYNOPSIS...
LOW PRESSURE WILL BE NEAR THE FORECAST AREA TONIGHT AND OFF THE
COAST TUESDAY. WINTER-TYPE PRECIPITATION WILL OCCUR ACROSS THE
NORTHERN PORTIONS OF SC BECAUSE OF THE COLDER AIR MASS IN PLACE
AHEAD OF THE SYSTEM. WELL BELOW NORMAL TEMPERATURES EXPECTED
THROUGH THE WEEK UNDER THE INFLUENCE OF AN ARCTIC AIR MASS.
&&
.NEAR TERM /TONIGHT/...
BROAD UPPER LEVEL TROUGH IN THE MIDWEST WILL CONTINUE SHIFTING
EAST WITH SOUTHWESTERLY FLOW INCREASING ACROSS THE CAROLINAS. LATEST
MODEL GUIDANCE STILL SUPPORTS LOW TRACK ACROSS THE WESTERN PART OF
THE FORECAST AREA TONIGHT. MODELS DO NOT HAVE A HANDLE ON THE
CURRENT SURFACE TEMPERATURES NORTH OF THE FRONT. THE CLOSEST
GUIDANCE APPEARS TO BE THE RUC AND HRRR...WITH THE ERLAV GUIDANCE
ALSO CLOSE. USED A GENERAL BLEND OF THAT GUIDANCE...WITH SOME
TWEAKS TO ACCOUNT FOR THE FREEZING LINE.
REGIONAL RADARS SHOW LARGE AREA OF PRECIP MOVING INTO THE
WESTERN/CENTRAL PORTIONS OF THE CWA. PRECIPITABLE WATER INCREASES
TO NEAR 1.3 INCHES BY 06Z TUESDAY AND ISENTROPIC LIFT IS ALSO VERY
STRONG DURING THIS TIME SO HAVE HIGHEST POPS 03Z TO 09Z. LEADING
EDGE OF THE PRECIP SHIELD HAS YIELDED ONLY LIGHT PRECIP...WITH
TRACE AMOUNTS. AS THE DEEPER MOISTURE/PRECIP MOVES INTO THE
AREA...AMOUNTS WILL INCREASE...WITH A FEW HUNDREDTHS AN HOUR BEING
SEEN. AT THIS TIME THE WEDGE IS HOLDING STRONG ACROSS THE UPSTATE
AND WESTERN CWA...WITH THE FREEZING LINE SITUATED JUST OFF TO THE
WEST OF LINCOLN/MCCORMICK COUNTIES...THEN UP TO NEWBERRY...THEN
ACROSS SOUTHERN LANCASTER COUNTY AND OVER TO CHERAW IN
CHESTERFIELD COUNTY. THIS LINE HAS REMAIN FAIRLY CONSTANT IN ITS
LOCATION THE PAST SEVERAL HOURS...AND TO NOT ANTICIPATE MUCH
MOVEMENT UNTIL THE SURFACE LOW NEARS THE AREA. AS THE LOW MOVES
THROUGH THERE MAY BE MINOR WARMING ALONG THE FRONT. THE CURRENT
FREEZING RAIN ADVISORY WILL REMAIN IN EFFECT OVERNIGHT...WHICH IS
IN LINE WITH THE CURRENT TEMPERATURES. ICING ESTIMATE IN MOST
AREAS LESS THAN A TENTH OF AN INCH WITH THE HIGHEST AMOUNTS
EXPECTED IN NORTHERN LANCASTER COUNTY OF UP TO TWO TENTHS OF AN
INCH. WILL CONTINUE TO MONITOR QPF AMOUNTS...AND CAN NOT RULE OUT
UPGRADING TO A WINTER WARNING IF SIGNIFICANT AMOUNTS OF ICE BECOME
LIKELY.
AREAS OFF TO THE SOUTH OF THE FREEZING LINE WILL REMAIN ALL RAIN
OVERNIGHT...ALTHOUGH AREAS CLOSE TO THE SURFACE FRONT MAY BE ABLE
TO SEE SOME SLEET MIXED IN AT TIMES UNTIL THE WARM NOSE ALOFT
MOVES INTO THE REGION AHEAD OF THE LOW. TEMPERATURES ACROSS THE
EXTREME SOUTH MAY ACTUALLY RISE OVERNIGHT AHEAD OF THE LOW DUE TO
STRONG WARM ADVECTION.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
BOTH THE NAM AND GFS SHOW THE CENTER OF THE LOW ALONG THE VA/NC
COAST BY 12Z TUESDAY MORNING WITH MOISTURE DECREASING ACROSS THE
AREA AS THE LOW CONTINUES TO SHIFT FURTHER NORTHEAST THROUGH THE
DAY ON TUESDAY. SHORTWAVE ENERGY ASSOCIATED WITH THE TROUGH WILL
PROMOTE A SLIGHT CHANCE OF LIGHT PRECIP TUESDAY MORNING AS IT
CROSSES THE REGION. MODEL SOUNDINGS SUGGEST MOISTURE BECOMING
QUITE SHALLOW EARLY TUESDAY...KEPT LOW CHANCE POPS EARLY AND
PRECIPITATION MAINLY LIQUID RAIN ALTHOUGH LIGHT FREEZING
RAIN/DRIZZLE POSSIBLE IN THE NORTH MIDLANDS THROUGH ABOUT 15Z.
MODELS CONTINUE TO HINT AT A SLIGHT CHANCE OF LIGHT SNOW TUESDAY
NIGHT AS THE UPPER TROUGH SHIFTS EAST...ALTHOUGH MOISTURE APPEARS
VERY LIMITED...SO HAVE KEPT POPS LOW FOR NOW. HIGHS ON TUESDAY ARE
FORECAST IN THE LOWER 40S NORTH TO LOWER 50S SOUTH. DECREASING
CLOUDS TUESDAY NIGHT WILL PROMOTE LOWS IN THE UPPER 20S NORTH TO
LOWER 30S SOUTH.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
GENERALLY DRY INTO THE WEEKEND. HIGH PRESSURE WILL BUILD IN FROM THE
WEST WITH A REINFORCING SHOT OF ARCTIC AIR MOVING INTO THE AREA
THURSDAY AND FRIDAY. ANOTHER LOW PRESSURE SYSTEM DEVELOPING IN
THE SOUTHERN PLAINS BY EARLY SATURDAY WILL MOVE INTO THE TN VALLEY
BY SUNDAY AS MORE HIGH PRESSURE BUILDS IN FROM THE NORTH. AS A
RESULT...A COLD AIR DAMMING SCENARIO MAY OVER THE WEEKEND INTO
MONDAY. STILL LOTS OF QUESTIONS REGARDING TIMING AND PLACEMENT OF
THIS NEXT SYSTEM AND THE POSSIBILITY OF ANY WINTRY PRECIPITATION
EARLY NEXT WEEK. BUT WITH SOME MANY MODEL UNCERTAINTIES AT THIS
TIME...FOR NOW WILL KEEP PRECIPITATION ALL LIQUID SATURDAY INTO
MONDAY WITH CHANCE POPS. TEMPERATURES GENERALLY BELOW NORMAL THROUGH
THE EXTENDED PERIOD...WITH WELL BELOW NORMAL TEMPERATURES THURSDAY
AND FRIDAY. IN FACT...CURRENT MEX/MEN GUIDANCE HAS TEMPERATURES
ABOUT 20 TO 25 DEGREES BELOW NORMAL FOR CAE AND AGS THURSDAY AND
FRIDAY.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
MVFR CIGS ACROSS MUCH OF THE FORECAST AREA CURRENTLY. AREA OF LOW
PRESSURE OVER N ALA WILL TRACK EAST ACROSS N CENT GA AND CENT SC
TONIGHT. ASSOCIATED AREA OF RAIN WILL SHIFT EAST ACROSS THE REGION.
EXPECT MVFR CIGS/VSBYS WITH THE RAIN AREA. NORTH OF THE LOW
TRACK...AN IN SITU WEDGE WITH LOW CIGS EXPECTED TO DEVELOP...WHICH
ARE EXPECTED TO SHIFT SOUTH ACROSS OUR TERMINALS ON THE BACK SIDE OF
THE DEPARTING SURFACE LOW LATE TONIGHT INTO EARLY TUESDAY MORNING.
MODELS SUGGEST THE BULK OF THE PRECIP WILL END FOR OUR TERMINALS
EARLY TUESDAY MORNING. THE WINDS WILL BE QUITE VARIABLE AND SHIFTING
IN DIRECTION THROUGH THE OVERNIGHT DUE TO THE PASSAGE OF THE LOW.
STRONG LOW LEVEL JET AHEAD OF THE LOW WARRANTS INCLUSION OF LLWS.
SLOW IMPROVEMENT IN CIGS EXPECTED DURING THE DAY TUESDAY.
EXTENDED AVIATION OUTLOOK...MVFR CIGS COULD LINGER OR REDEVELOP INTO
TUESDAY NIGHT. BREEZY CONDITIONS EXPECTED WEDNESDAY AND THURSDAY.
CIG RESTRICTIONS AND SHOWER CHANCES COULD RETURN SAT/SUN.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...FREEZING RAIN ADVISORY UNTIL 7 AM EST TUESDAY FOR SCZ015-016-
020>022.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
617 PM EST MON FEB 16 2015
.SYNOPSIS...
LOW PRESSURE WILL BE NEAR THE FORECAST AREA TONIGHT AND OFF THE
COAST TUESDAY. WINTER-TYPE PRECIPITATION WILL OCCUR ACROSS THE
NORTHERN PORTIONS OF SC BECAUSE OF THE COLDER AIR MASS IN PLACE
AHEAD OF THE SYSTEM. WELL BELOW NORMAL TEMPERATURES EXPECTED
THROUGH THE WEEK UNDER THE INFLUENCE OF AN ARCTIC AIR MASS.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
BROAD UPPER LEVEL TROUGH IN THE MIDWEST WILL CONTINUE SHIFTING
EAST WITH SOUTHWESTERLY FLOW INCREASING ACROSS THE CAROLINAS. 19Z
SURFACE ANALYSIS SHOWS HIGH PRESSURE ALONG THE NC/VA COAST RIDGING
INTO THE FORECAST AREA. MEANWHILE...LOW PRESSURE OVER THE TN/MS
VALLEY REGION IS SHIFTING NORTHEAST TOWARD THE REGION ACCOMPANIED
BY A LARGE SWATH OF PRECIPITATION. REGIONAL RADAR COMPOSITE THIS
AFTERNOON SHOWS LIGHT PRECIPITATION BEGINNING TO MOVE INTO THE
WESTERN MIDLANDS AND CSRA WHICH IS SUPPORTED BY WARM ADVECTION AND
ISENTROPIC LIFT AHEAD OF THE LOW. WE HAVE RECEIVED A FEW REPORTS
OF LIGHT SLEET IN NEWBERRY COUNTY. DRY AIR MASS IS MOISTENING FROM
THE SOUTH THIS AFTERNOON WITH DEWPOINTS ON THE RISE. DEWPOINTS IN
THE PEE DEE AND NORTHERN MIDLANDS REMAIN VERY DRY...GENERALLY IN
THE SINGLE DIGITS.
LATEST MODEL GUIDANCE STILL SUPPORTS LOW TRACK ACROSS THE WESTERN
PART OF THE FORECAST AREA TONIGHT. HRRR APPEARS TO BE TRACKING
WELL WITH CURRENT RADAR TRENDS AND IS MUCH FASTER WITH THE PRECIP
REACHING THE AREA THAN THE 12Z NAM. THIS AGREES PRETTY WELL WITH
TIMING IN CURRENT FORECAST SO HAVE NOT MADE ANY TIMING
ADJUSTMENTS. HIGH RESOLUTION MODELS LIKE THE RAP AND HRRR ARE
WARMER THAN SOME OF THE OTHER GUIDANCE BUT BELIEVE THIS MAY BE
A LITTLE OVERDONE AS THESE MODELS HAVE BEEN TOO HIGH WITH THE
DEWPOINTS SO FAR TODAY. PRECIPITABLE WATER INCREASES TO NEAR 1.3
INCHES BY 06Z TUESDAY AND ISENTROPIC LIFT IS ALSO VERY STRONG
DURING THIS TIME SO HAVE HIGHEST POPS 03Z TO 09Z. MODEL SOUNDINGS
INDICATE DEEP WARM NOSE ACROSS THE REGION TONIGHT AS VERY STRONG
LOW LEVEL WARM ADVECTION DEVELOPS. SOUTHWEST 850MB JETMAX GREATER
THAN 60KTS. SHALLOW FREEZING LAYER LIKELY NORTH OF CAE. LARGE
TEMPERATURE GRADIENT EXPECTED WITH FREEZING TEMPS NORTH OF CAE
TONIGHT TO POSSIBLY LOW 50S IN THE CSRA AS WARM ADVECTION
INCREASES AND DEEPENS. TEMPERATURES EXPECTED TO RISE OVERNIGHT IN
THE SOUTHERN AREAS.
WITH DEEP WARM NOSE AND SHALLOW FREEZING LAYER...STILL EXPECT
FREEZING RAIN IN THE NORTH MIDLANDS...PIEDMONT AND PEE DEE
OVERNIGHT. ICING ESTIMATE IN MOST AREAS LESS THAN A TENTH OF AN
INCH WITH THE HIGHEST AMOUNTS EXPECTED IN NORTHERN LANCASTER
COUNTY OF UP TO TWO TENTHS OF AN INCH. FREEZING RAIN ADVISORY
REMAINS IN EFFECT.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
BOTH THE NAM AND GFS SHOW THE CENTER OF THE LOW ALONG THE VA/NC
COAST BY 12Z TUESDAY MORNING WITH MOISTURE DECREASING ACROSS THE
AREA AS THE LOW CONTINUES TO SHIFT FURTHER NORTHEAST THROUGH THE
DAY ON TUESDAY. SHORTWAVE ENERGY ASSOCIATED WITH THE TROUGH WILL
PROMOTE A SLIGHT CHANCE OF LIGHT PRECIP TUESDAY MORNING AS IT
CROSSES THE REGION. MODEL SOUNDINGS SUGGEST MOISTURE BECOMING
QUITE SHALLOW EARLY TUESDAY...KEPT LOW CHANCE POPS AND
PRECIPITATION MAINLY LIQUID RAIN ALTHOUGH LIGHT FREEZING
RAIN/DRIZZLE POSSIBLE IN THE NORTH MIDLANDS THROUGH ABOUT 15Z.
MODELS CONTINUE TO HINT AT A SLIGHT CHANCE OF LIGHT SNOW TUESDAY
NIGHT AS THE UPPER TROUGH SHIFTS EAST...ALTHOUGH MOISTURE APPEARS
VERY LIMITED...SO HAVE KEPT POPS LOW FOR NOW. HIGHS ON TUESDAY ARE
FORECAST IN THE LOWER 40S NORTH TO LOWER 50S SOUTH. DECREASING
CLOUDS TUESDAY NIGHT WILL PROMOTE LOWS IN THE UPPER 20S NORTH TO
LOWER 30S SOUTH.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
GENERALLY DRY INTO THE WEEKEND. HIGH PRESSURE WILL BUILD IN FROM THE
WEST WITH A REINFORCING SHOT OF ARCTIC AIR MOVING INTO THE AREA
THURSDAY AND FRIDAY. ANOTHER LOW PRESSURE SYSTEM DEVELOPING IN
THE SOUTHERN PLAINS BY EARLY SATURDAY WILL MOVE INTO THE TN VALLEY
BY SUNDAY AS MORE HIGH PRESSURE BUILDS IN FROM THE NORTH. AS A
RESULT...A COLD AIR DAMMING SCENARIO MAY OVER THE WEEKEND INTO
MONDAY. STILL LOTS OF QUESTIONS REGARDING TIMING AND PLACEMENT OF
THIS NEXT SYSTEM AND THE POSSIBILITY OF ANY WINTRY PRECIPITATION
EARLY NEXT WEEK. BUT WITH SOME MANY MODEL UNCERTAINTIES AT THIS
TIME...FOR NOW WILL KEEP PRECIPITATION ALL LIQUID SATURDAY INTO
MONDAY WITH CHANCE POPS. TEMPERATURES GENERALLY BELOW NORMAL THROUGH
THE EXTENDED PERIOD...WITH WELL BELOW NORMAL TEMPERATURES THURSDAY
AND FRIDAY. IN FACT...CURRENT MEX/MEN GUIDANCE HAS TEMPERATURES
ABOUT 20 TO 25 DEGREES BELOW NORMAL FOR CAE AND AGS THURSDAY AND
FRIDAY.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
MVFR CIGS ACROSS MUCH OF THE FORECAST AREA CURRENTLY. AREA OF LOW
PRESSURE OVER N ALA WILL TRACK EAST ACROSS N CENT GA AND CENT SC
TONIGHT. ASSOCIATED AREA OF RAIN WILL SHIFT EAST ACROSS THE REGION.
EXPECT MVFR CIGS/VSBYS WITH THE RAIN AREA. NORTH OF THE LOW
TRACK...AN IN SITU WEDGE WITH LOW CIGS EXPECTED TO DEVELOP...WHICH
ARE EXPECTED TO SHIFT SOUTH ACROSS OUR TERMINALS ON THE BACK SIDE OF
THE DEPARTING SURFACE LOW LATE TONIGHT INTO EARLY TUESDAY MORNING.
MODELS SUGGEST THE BULK OF THE PRECIP WILL END FOR OUR TERMINALS
EARLY TUESDAY MORNING. THE WINDS WILL BE QUITE VARIABLE AND SHIFTING
IN DIRECTION THROUGH THE OVERNIGHT DUE TO THE PASSAGE OF THE LOW.
STRONG LOW LEVEL JET AHEAD OF THE LOW WARRANTS INCLUSION OF LLWS.
SLOW IMPROVEMENT IN CIGS EXPECTED DURING THE DAY TUESDAY.
EXTENDED AVIATION OUTLOOK...MVFR CIGS COULD LINGER OR REDEVLOP INTO
TUESDAY NIGHT. BREEZY CONDITIONS EXPECTED WEDNESDAY AND THURSDAY.
CIG RESTRICTIONS AND SHOWER CHANCES COULD RETURN SAT/SUN.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...FREEZING RAIN ADVISORY UNTIL 7 AM EST TUESDAY FOR SCZ015-016-
020>022.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
953 PM EST MON FEB 16 2015
.UPDATE...
THE SYNOPSIS AND NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 953 PM EST MON FEB 16 2015
A HIGH PRESSURE RIDGE WILL BRIEFLY BUILD IN OVERNIGHT WITH MAINLY
CLEAR SKIES AND COLD TEMPERATURES. THE UPPER TROUGH OVER THE AREA
WILL GET REINFORCED TUESDAY NIGHT WITH ANOTHER SHOT OF COLD AIR
THAT WILL BRING DANGEROUS COLD TO THE AREA TUESDAY NIGHT THROUGH
THURSDAY NIGHT. THE WEEKEND SHOULD BRING A WARMUP TO THE AREA BUT
WILL ALSO BRING ADDITIONAL CHANCES FOR ACCUMULATING SNOW.
&&
.NEAR TERM /OVERNIGHT/...
ISSUED AT 953 PM EST MON FEB 16 2015
SNOW HAS DEPARTED OUT OF THE FORECAST AREA WITH FAIRLY RAPID
CLEARING AS A HIGH PRESSURE RIDGE BUILDS ACROSS THE AREA. TEMPS
VARIED WIDELY AT 0230Z...RANGING FROM NEAR 0 DEGREES IN SOME
LOCATIONS WITH A SNOWPACK TO THE TEENS IN OTHER SPOTS.
AFTER THE SNOWFALL TODAY...RELATIVELY QUIET FORECAST SETS UP
OVERNIGHT WITH THE ONLY REAL ISSUE FOCUSED ON THE LOW TEMPS. HIGH
PRESSURE RIDGE WILL DRIFT EAST ACROSS THE OHIO VALLEY TONIGHT WITH
STRATUS BACK OVER THE MISSISSIPPI VALLEY HOLDING OFF UNTIL LATE
TONIGHT IN THE WEST AND LIKELY CLOSER TO DAYBREAK OVER EASTERN
COUNTIES. WITH MAINLY CLEAR SKIES EXPECTED FOR SEVERAL HOURS AND
LIGHT WINDS...TEMPERATURES WILL TUMBLE. COLDEST TEMPS WILL LIKELY
BE FOUND IN SOUTHERN COUNTIES WITH THE PRESENCE OF A FRESH AND IN
SOME SPOTS DEEP SNOWPACK. UTILIZED 00Z RAP FOR HOURLY TEMPS BUT IN
GENERAL...DROPPED LOWS IN SOME SPOTS SEVERAL DEGREES. DO EXPECT
NORMAL COOL SPOTS OVER SOUTHERN FORECAST AREA WILL GO SUBZERO...
MAYBE AS LOW AS -5.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
ISSUED AT 348 PM EST MON FEB 16 2015
THE MAIN FOCUS IN THE SHORT TERM IS THE COLD TEMPERATURES AND WIND
CHILLS. MODELS ARE IN DECENT AGREEMENT ON PATTERN BUT MOS GUIDANCE
NUMBERS SHOWING SOME DIFFERENCES AND WILL DISCUSS PREFERENCE AND
REASONING BELOW.
A LARGE UPPER TROUGH WILL CONTINUE TO HOLD SWAY OVER THE EASTERN U.S
THROUGH THE SHORT TERM. THIS WILL ALLOW FOR A STEADY STREAM OF COLD
AIR INTO CENTRAL INDIANA. GIVEN MODEL 850 MB TEMPERATURES STARTING
IN THE -TEENS AND DROPPING INTO THE -22 TO -28 RANGE HAVE FAVORED
THE COLDER GUIDANCE NUMBERS OF THE MAV...AND HAVE EVEN DROPPED SOME
FROM THERE AT TIMES. LOWS TUESDAY NIGHT/WEDNESDAY MORNING WILL BE IN
THE LOW SINGLE DIGITS TO BELOW ZERO OVER THE SOUTHERN AREAS WITH
SNOWPACK FROM TODAY. WEDNESDAY NIGHT COULD SEE LOWS FROM A FEW
DEGREES BELOW ZERO TO NEAR 10 BELOW ZERO OVER THE SNOWPACK. HIGHS ON
WEDNESDAY AND THURSDAY WILL BE MAINLY IN THE SINGLE DIGITS.
WITH CYCLONIC FLOW LOOK FOR MOSTLY CLOUDY SKIES TO BE THE RULE ALONG
WITH SOME SLIGHT CHANCES FOR LIGHT SNOW AND BETTER CHANCES FOR
FLURRIES OFF AND ON. THERE IS SOME DISCERNIBLE UPPER FORCING TUESDAY
EVENING AND AGAIN ON WEDNESDAY BUT WITH LITTLE MOISTURE TO WORK WITH
WILL JUST CARRY SLIGHT CHANCES.
WILL LIKELY NEED HEADLINES FOR WIND CHILLS WEDNESDAY AND
THURSDAY...BUT GIVEN THE NUMBER OF PERIODS OUT AND CURRENT
HEADLINES RUNNING WOULD PREFER TO WAIT PAST THIS ISSUANCE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 245 PM EST MON FEB 16 2015
TEMPERATURES AND POPS INCLUDING TIMING AND PRECIP TYPE WILL BE THE
MAIN CONCERN FOR THE EXTENDED. AT THIS TIME...EXTENDED MODELS AND
ENSEMBLES ARE TOO FAR APART TO CONFIDENTLY CHANGE THE REGIONAL
BLEND...SO LEFT IT AS IT IS WITH CHANCE POPS STARTING FRIDAY NIGHT
AS A WARM FRONT LIFTS UP FROM THE SOUTHWEST. POPS IN ORDER THROUGH
LATE WEEKEND WITH SOUTHERLY FLOW AHEAD OF A FRONTAL SYSTEM. COULD
SEE A WINTRY MIX ACROSS OUR FAR SOUTHERN ZONES..BUT AT THIS POINT
WILL LEAVE IT ALL SNOW AND ADJUST AS IT GETS CLOSER AND OR MODELS
CONVERGE UPON A COMMON SOLUTION.
TEMPERATURES SHOULD START OFF COLD WITHIN DEPARTING ARCTIC HIGH
PRESSURE BUT THEN WARM TO CLOSER TO NORMAL BY SATURDAY AS THE WARM
FRONT MOVES THROUGH. STILL...EVEN THEN AND MORE SO AFTER THE COLD
FRONTAL PASSAGE...BELOW NORMAL TEMPERATURES WILL CONTINUE.
&&
.AVIATION /DISCUSSION FOR THE 170300Z KIND TAF UPDATE/...
ISSUED AT 913 PM EST MON FEB 16 2015
NO SIGNIFICANT CHANGES MADE TO THE FORECAST AT THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.
BACK EDGE OF PRECIPITATION SHIELD EXPECTED TO BE
SOUTH OF THE TAF SITES BY ISSUANCE TIME BASED ON RADAR LOOP.
CEILINGS ABOVE 050 SHOULD GRADUALLY THIN OUT FROM NORTHWEST TO
SOUTHEAST LATER TONIGHT. MODEL GUIDANCE SUGGESTS SOME FOG POTENTIAL
DURING THE EARLY MORNING HOURS AT KHUF/KBMG AFTER CLOUDS THIN OUT
OVER FRESH SNOW COVER...BUT CONFIDENCE NOT HIGH ENOUGH YET TO
INCLUDE IN THE FORECAST. VFR CEILINGS 040-050 CURRENTLY PUSHING INTO
NORTHWEST ILLINOIS EXPECTED TO BEGIN MOVING OVER THE TAF SITES FROM
THE NORTHWEST AFTER ABOUT 170900Z.
SURFACE WINDS 010-040 DEGREES AROUND 7 KTS EARLY THIS EVENING
EXPECTED TO BECOME LIGHT BY LATE TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP/RYAN
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM...MK
AVIATION...JAS
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
716 PM MST MON FEB 16 2015
.UPDATE...
ISSUED AT 706 PM MST MON FEB 16 2015
CURRENT FORECAST CONCERN WILL BE HOW FAR SOUTH CURRENT AREA OF
SNOW IN NORTHERN NEBRASKA GETS BEFORE DIMINISHING. H85-H7 LAPSE
RATES REMAIN FAVORABLE FOR THE NEXT 2 HOURS BUT BEGIN TO DECREASE
AFTER THAT. GIVEN THE CURRENT MOTION...DOUBTFUL ATMOSPHERE WILL BE
AS UNSTABLE BY THEN AND AM GOING TO LEAN TOWARDS PRECIP NOT MAKING
IT...BUT WILL KEEP AN EYE ON THINGS. OTHERWISE...ANOTHER ROUND OF
SNOW SHOWERS APPEARS POSSIBLE TOMORROW AND FINE TUNED POPS A BIT
TO HIGHLIGHT MOST LIKELY AREAS.
POTENTIAL FOR STRONG WINDS REMAINS...ALTHOUGH STRONGEST (50KT)
WINDS APPEAR TO BE ABOVE THE DRY ADIABATIC MIXED LAYER. WHILE A
PARCEL COULD POTENTIALLY MIX DOWN THE STRONGER WINDS...THINK IT IS
MORE LIKELY THAT CLOUDS AND SHOWERS WOULD LIMIT POTENTIAL FOR
BRINGING THESE WINDS INTO THE BOUNDARY LEVEL.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 208 PM MST MON FEB 16 2015
LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS BROAD TROUGH
ACROSS THE EASTERN US WITH SHORTWAVE ALONG BASE OF TROUGH OVER
COLORADO. AT THE SURFACE LOW PRESSURE REMAINS IN PLACE OVER NORTH
CENTRAL KANSAS...WITH HIGH PRESSURE ACROSS THE NORTHERN ROCKIES
EXTENDING SOUTH TOWARDS NORTHERN COLORADO.
STEEP LOW LEVEL LAPSE RATES AND WEAK INSTABILITY HAVE LED TO
RAIN/SNOW SHOWER DEVELOPMENT THIS AFTERNOON ACROSS THE CWA.
GRAUPEL HAS BEEN OBSERVED WITH SOME OF THIS ACTIVITY. THIS
ACTIVITY WILL MAINLY BE TIED TO DAYTIME HEATING...QUICKLY ENDING
AS LOW LEVELS STABILIZE NEAR SUNSET. THERE WILL BE SOME WEAK
FORCING AROUND THE REGION OVERNIGHT...HOWEVER OTHER THAN MAYBE A
FEW FLURRIES IT DOESN`T APPEAR TO BE SUPPORTIVE OF MEASURABLE
PRECIP.
BETTER FORCING IS PROGGED TO MOVE THROUGH THE REGION BY 12Z
TUESDAY AS POSITIVE MID LEVEL VORTICITY ASSOCIATED WITH SHORTWAVE
TROUGH ROTATES INTO THE REGION. THIS WILL RESULT IN SHOWER
REDEVELOPMENT FROM THE NORTH TO THE SOUTH...INCREASING IN COVERAGE
AS LAPSE RATES STEEPEN WITH DAYTIME HEATING. I COULD SEE A
RAIN/SNOW/ICE PELLET MIX AGAIN LIKE TODAY...WITH MINIMAL TO NO
ACCUMULATIONS. UNIDIRECTIONAL GRADIENT AND WINDS ALOFT INCREASE
DURING THE DAY...AND IF WE WERE TO MIX TO 700MB WE COULD SEE
WARNING CRITERIA WINDS MIX TO THE SURFACE. MIXING HEIGHTS APPEAR
TO BE LIMITED DUE TO INCREASING CLOUD COVER...THOUGH THERMAL
PROFILES IN CLEAR SKIES COULD SUPPORT MUCH DEEPER MIXING. FOR NOW
I KEPT GUSTS 45-50MPH. THERE IS A CONCERN THAT SHOWERS COULD HELP
MIX STRONGER WINDS TO THE SURFACE. WINDS COULD ALSO COMBINE WITH
SHOWERS TO REDUCE VISIBILITIES.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 141 PM MST MON FEB 16 2015
WITH THE PASSAGE OF THE SHORTWAVE THRU THE CWA ON TUESDAY...THE TRI
STATE REGION WILL TREND INTO A DRY PERIOD FROM TUESDAY NIGHT RIGHT
INTO 12Z FRIDAY. DURING THIS TIMEFRAME...H5 RIDGE WILL FLATTEN SOME
OVER THE WESTERN PORTION OF THE COUNTRY...ALLOWING FOR WNW FLOW OVER
THE AREA. AT THE SURFACE...HIGH PRESSURE SLIDES SOUTH FROM CANADA
SHIFTING EAST THRU THE WEEK...AND A LEE-SIDE TROUGH SETS UP OVER THE
EASTERN SIDE OF THE ROCKIES. INCREASING WAA WILL RESULT AS SOUTHERLY
FLOW TAPS INTO WARMER AIR. FROM FRIDAY ON THRU NEXT MONDAY...
SHORTWAVE WILL PINWHEEL AROUND BROAD UPPER LOW TO THE EAST...SETTING
UP OVER THE ROCKIES. BLOCKING PATTERN OFF THE WEST COAST...AS WELL
AS OVER THE CENTRAL ATLANTIC OCEAN...KEEPS UPPER TROUGH OVER THE
ROCKIES. THIS SYSTEM WILL BE ABLE TO TAP INTO PACIFIC MOISTURE...
FEEDING IT INTO THE REGION FOR THE PERIOD. AT THE SURFACE HIGH
PRESSURE AGAIN BUILDING DOWN FROM CENTRAL CANADA WILL PROVIDE AN
EASTERLY/UPSLOPE FETCH INTO THE REGION. THE RESULT WILL BE CHANCE
POPS FOR -SW THRU THE ENTIRE FRIDAY THRU MONDAY TIMEFRAME WITH LIGHT
SCATTERED AMOUNTS. A WAA TREND FOR THE FIRST HALF OF THE EXTENDED
WILL GIVE WAY TO BELOW NORMAL NUMBERS WITH THE ARRIVAL OF THE COLD
CANADIAN RIDGE. OVERALL HIGHS WILL RANGE FROM THE 40S WEDNESDAY UP
TO NEAR 60F FOR THURS/FRI...THEN DROP DOWN INTO THE 20S TO L30S FOR
THE WEEKEND INTO NEXT MONDAY. OVERNIGHT LOWS WILL SEE BIG DROP AT
THE END OF THE WEEK WITH CANADIAN RIDGE OVER AREA. LOWS WILL RANGE
FROM THE TEENS AND MID 20S THRU FRIDAY NIGHT...THEN DOWN TO THE
TEENS AND SINGLE NUMBERS OVER THE UPCOMING WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 439 PM MST MON FEB 16 2015
CURRENT SHALLOW CONVECTIVE SHOWERS WILL CONTINUE TO DECREASE IN
INTENSITY AND COVERAGE AS THE SUN GOES DOWN AND TEMPERATURES COOL.
COULD STILL SEE A STRAY SHOWER NEAR MCCOOK BEFORE 02Z...BUT DO NOT
EXPECT TO SEE LIFR CONDITIONS THAT APPEARED WITH PREVIOUS
ACTIVITY. OTHER WISE...EXPECT A PERIOD OF VFR CONDITIONS TO
DEVELOP OVERNIGHT WITH WINDS OUT OF THE WNW. AS THE MORNING
COMMENCES...LITTLE HEATING IS REQUIRED FOR DEVELOPMENT OF LOW
STRATOCUMULUS AND ANOTHER ROUND OF SNOW SHOWERS. NOT READY TO
BRING DOWN THE VISBY FORECAST ANYWHERE BUT PERIOD OF MVFR CIGS IS
LIKELY AT MCK.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...DR
LONG TERM...JN
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
448 PM MST MON FEB 16 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 208 PM MST MON FEB 16 2015
LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS BROAD TROUGH
ACROSS THE EASTERN US WITH SHORTWAVE ALONG BASE OF TROUGH OVER
COLORADO. AT THE SURFACE LOW PRESSURE REMAINS IN PLACE OVER NORTH
CENTRAL KANSAS...WITH HIGH PRESSURE ACROSS THE NORTHERN ROCKIES
EXTENDING SOUTH TOWARDS NORTHERN COLORADO.
STEEP LOW LEVEL LAPSE RATES AND WEAK INSTABILITY HAVE LED TO
RAIN/SNOW SHOWER DEVELOPMENT THIS AFTERNOON ACROSS THE CWA.
GRAUPEL HAS BEEN OBSERVED WITH SOME OF THIS ACTIVITY. THIS
ACTIVITY WILL MAINLY BE TIED TO DAYTIME HEATING...QUICKLY ENDING
AS LOW LEVELS STABILIZE NEAR SUNSET. THERE WILL BE SOME WEAK
FORCING AROUND THE REGION OVERNIGHT...HOWEVER OTHER THAN MAYBE A
FEW FLURRIES IT DOESN`T APPEAR TO BE SUPPORTIVE OF MEASURABLE
PRECIP.
BETTER FORCING IS PROGGED TO MOVE THROUGH THE REGION BY 12Z
TUESDAY AS POSITIVE MID LEVEL VORTICITY ASSOCIATED WITH SHORTWAVE
TROUGH ROTATES INTO THE REGION. THIS WILL RESULT IN SHOWER
REDEVELOPMENT FROM THE NORTH TO THE SOUTH...INCREASING IN COVERAGE
AS LAPSE RATES STEEPEN WITH DAYTIME HEATING. I COULD SEE A
RAIN/SNOW/ICE PELLET MIX AGAIN LIKE TODAY...WITH MINIMAL TO NO
ACCUMULATIONS. UNIDIRECTIONAL GRADIENT AND WINDS ALOFT INCREASE
DURING THE DAY...AND IF WE WERE TO MIX TO 700MB WE COULD SEE
WARNING CRITERIA WINDS MIX TO THE SURFACE. MIXING HEIGHTS APPEAR
TO BE LIMITED DUE TO INCREASING CLOUD COVER...THOUGH THERMAL
PROFILES IN CLEAR SKIES COULD SUPPORT MUCH DEEPER MIXING. FOR NOW
I KEPT GUSTS 45-50MPH. THERE IS A CONCERN THAT SHOWERS COULD HELP
MIX STRONGER WINDS TO THE SURFACE. WINDS COULD ALSO COMBINE WITH
SHOWERS TO REDUCE VISIBILITIES.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 141 PM MST MON FEB 16 2015
WITH THE PASSAGE OF THE SHORTWAVE THRU THE CWA ON TUESDAY...THE TRI
STATE REGION WILL TREND INTO A DRY PERIOD FROM TUESDAY NIGHT RIGHT
INTO 12Z FRIDAY. DURING THIS TIMEFRAME...H5 RIDGE WILL FLATTEN SOME
OVER THE WESTERN PORTION OF THE COUNTRY...ALLOWING FOR WNW FLOW OVER
THE AREA. AT THE SURFACE...HIGH PRESSURE SLIDES SOUTH FROM CANADA
SHIFTING EAST THRU THE WEEK...AND A LEE-SIDE TROUGH SETS UP OVER THE
EASTERN SIDE OF THE ROCKIES. INCREASING WAA WILL RESULT AS SOUTHERLY
FLOW TAPS INTO WARMER AIR. FROM FRIDAY ON THRU NEXT MONDAY...
SHORTWAVE WILL PINWHEEL AROUND BROAD UPPER LOW TO THE EAST...SETTING
UP OVER THE ROCKIES. BLOCKING PATTERN OFF THE WEST COAST...AS WELL
AS OVER THE CENTRAL ATLANTIC OCEAN...KEEPS UPPER TROUGH OVER THE
ROCKIES. THIS SYSTEM WILL BE ABLE TO TAP INTO PACIFIC MOISTURE...
FEEDING IT INTO THE REGION FOR THE PERIOD. AT THE SURFACE HIGH
PRESSURE AGAIN BUILDING DOWN FROM CENTRAL CANADA WILL PROVIDE AN
EASTERLY/UPSLOPE FETCH INTO THE REGION. THE RESULT WILL BE CHANCE
POPS FOR -SW THRU THE ENTIRE FRIDAY THRU MONDAY TIMEFRAME WITH LIGHT
SCATTERED AMOUNTS. A WAA TREND FOR THE FIRST HALF OF THE EXTENDED
WILL GIVE WAY TO BELOW NORMAL NUMBERS WITH THE ARRIVAL OF THE COLD
CANADIAN RIDGE. OVERALL HIGHS WILL RANGE FROM THE 40S WEDNESDAY UP
TO NEAR 60F FOR THURS/FRI...THEN DROP DOWN INTO THE 20S TO L30S FOR
THE WEEKEND INTO NEXT MONDAY. OVERNIGHT LOWS WILL SEE BIG DROP AT
THE END OF THE WEEK WITH CANADIAN RIDGE OVER AREA. LOWS WILL RANGE
FROM THE TEENS AND MID 20S THRU FRIDAY NIGHT...THEN DOWN TO THE
TEENS AND SINGLE NUMBERS OVER THE UPCOMING WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 439 PM MST MON FEB 16 2015
CURRENT SHALLOW CONVECTIVE SHOWERS WILL CONTINUE TO DECREASE IN
INTENSITY AND COVERAGE AS THE SUN GOES DOWN AND TEMPERATURES COOL.
COULD STILL SEE A STRAY SHOWER NEAR MCCOOK BEFORE 02Z...BUT DO NOT
EXPECT TO SEE LIFR CONDITIONS THAT APPEARED WITH PREVIOUS
ACTIVITY. OTHER WISE...EXPECT A PERIOD OF VFR CONDITIONS TO
DEVELOP OVERNIGHT WITH WINDS OUT OF THE WNW. AS THE MORNING
COMMENCES...LITTLE HEATING IS REQUIRED FOR DEVELOPMENT OF LOW
STRATOCUMULUS AND ANOTHER ROUND OF SNOW SHOWERS. NOT READY TO
BRING DOWN THE VISBY FORECAST ANYWHERE BUT PERIOD OF MVFR CIGS IS
LIKELY AT MCK.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JN
AVIATION...JRM
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...UPDATED
NWS JACKSON KY
1100 PM EST MON FEB 16 2015
.UPDATE...
ISSUED AT 1055 PM EST MON FEB 16 2015
THE BACK EDGE OF THE STEADIER SNOW OR FLURRIES HAS WORKED EAST OF
INTERSTATE 75 PER RADAR IMAGERY AND REGIONAL OBSERVATIONS.
HOWEVER...SOME ENHANCED RETURNS REMAIN IN THE FAR SOUTHEAST...BUT
THIS BAND SHOULD GRADUALLY MOVE INTO VA AND WV OVER THE NEXT HOUR.
NEAR TERM MODELS...SUCH AS THE HRRR RUNS HAVE ALL THE SNOW IN THE
FAR SOUTHEAST ENDING BY 7Z TO 8Z...OR 2 TO 3 AM. AT THIS TIME...WE
PLAN TO ALLOW THE WARNINGS TO RUN THEIR COURSE AND THEN REPLACE
WITH AN SPS FOR THE REMAINDER OF THE OVERNIGHT.
UPDATE ISSUED AT 755 PM EST MON FEB 16 2015
THE STEADIER SNOW HAS TAPERED OFF...BUT LIGHT TO MODERATE SNOW
REMAINS AND THERE ARE SOME ENHANCED AREAS OF REFLECTIVITY ACROSS
THE SOUTHEASTERN COUNTIES. THE THREAT FOR AT LEAST LIGHT SNOW WILL
REMAIN UNTIL THE UPPER LEVEL TROUGH MOVES THROUGH. EVEN WITH RATES
HAVING DECREASED...SNOW COVERED ROADS REMAIN AND EVEN ANY LIGHT
ADDITIONAL SNOW WILL IMPACT TRAVEL AND BEGIN TO FILL BACK IN ROADS
THAT HAVE BEEN PLOWED. ATTM...PLANS OUR TO LET THE WINTER STORM
WARNINGS WILL BE ALLOWED TO RUN THEIR COURSE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 415 PM EST MON FEB 16 2015
A WINTER STORM TRACKING ACROSS THE SOUTHEASTERN STATES WILL REACH
THE CAROLINA COASTLINE LATE TONIGHT AND THEN OFF THE EAST COAST
BY TUESDAY MORNING. A WESTERN RIDGE AND EASTERN TROUGH PATTERN IS
EXPECTED THROUGH MIDWEEK. A DEEP CLOSED LOW WILL DIVE SOUTH TOWARD
THE GREAT LAKES AND SOUTHERN ONTARIO AND BRING THE BEGINNING OF
ANOTHER ARCTIC BLAST LATE STARTING ON TUESDAY NIGHT. THIS WINTER
STORM IS BRINGING THE MOST WIDESPREAD IMPACTS AS FAR AS SNOWFALL
TO THE REGION IN THE LAST 10 TO 20 YEARS. IN MANY PLACES...THE
SNOW HAS BEEN ON THE DRIER SIDE...WHICH IS LIMITING POWER OUTAGE
POTENTIAL. SOME LOWER RATIO SNOW IS LIKELY FALLING CLOSER TO THE
VA AND TN BORDERS WHERE THE ATMOSPHERE IS WARMER. THIS LOW
THE WINTER STORM CONTINUES TO AFFECT THE REGION AND IT IS LEADING
TO TOTALS NEAR DOUBLE DIGITS IF NOT NEARLY A FOOT OR MORE ATTM.
AS THE SHORTWAVE TROUGH APPROACHES THE AREA THE LATEST SHORT TERM
GUIDANCE SUGGEST MODERATE TO HEAVY SNOW HANGING ON THROUGH LATE
EVENING WITH RATES OF 1 TO 2 INCH PER HOUR AT TIMES. LOCATIONS
NEAR THE TN AND VA BORDERS...SHOULD ALSO EXPERIENCE AN END TO MIX
WITH FREEZING RAIN AND SLEET. THE SNOW SHOULD WIND DOWN BY
MIDNIGHT OR 1 AM IN MOST LOCATIONS. AN ADDITIONAL TWO OR THREE TO
SEVEN INCHES SHOULD FALL THROUGH THE END OF THE EVENT.
A RIDGE OF HIGH PRESSURE WILL BRING A RESPITE TO THE SNOW CHANCES
AS THE LOW DEPARTS...BUT ADDITIONAL SNOW SHOWERS ARE POSSIBLE LATE
ON TUESDAY AS A WAVE TRACKS INTO THE MID SOUTH. THE THREAT FOR THE
SNOW SHOWERS WILL LINGER THROUGH THE END OF THE PERIOD AS AN
ARCTIC BOUNDARY APPROACHES AND CROSSES THE AREA. THE THREAT FOR
THESE SNOW SHOWERS WILL LINGER INTO THE LONG TERM PERIOD.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 355 PM EST MON FEB 16 2015
ALL EYES TURN TO A ARCTIC COLD FRONT DROPPING SOUTHEAST THROUGH
THE DAY ON WEDNESDAY. SPOKE OF UPPER LEVEL ENERGY FROM A QUASI
STATIONARY UPPER LEVEL CLOSED LOW ACROSS CANADA WILL BRING ARCTIC
AIR SOUTH INTO THE OHO VALLEY. THERE WILL BE SOME MOISTURE WITH
THIS FRONT AND COUPLED WITH SURFACE TO 3 KM LAPSE RATES 8 C/KM
BASED ON NAM...GIVEN THIS WOULD EXPECT THERE TO ONCE AGAIN BE SNOW
SQUALLS ACROSS THE REGION ESPECIALLY IN THE AFTERNOON ON
WEDNESDAY. THESE SQUALLS WILL BE ACCOMPANIED BY STRONG WINDS AND
WHITE OUT CONDITIONS. THIS UNSTABLE ATMOSPHERE PRESENTED BY THE
GUIDANCE WOULD ALSO SUPPORT ISOLATED THUNDERSNOW IN HEAVIER SNOW
SQUALLS. THIS INSTABILITY AND MOISTURE ARE PERSISTENT EVEN INTO
THE EVENING. BEHIND THIS FRONT EXPECT TEMPERATURES TO QUICKLY FALL
THROUGH THE EVENING WEDNESDAY INTO THE SINGLE DIGITS. THURSDAY
MORNING LOWS BOTTOM OUT INTO THE NEG SINGLE DIGITS WITH WIND
CHILLS WELL INTO THE NEG TEENS IN MANY SPOTS. THIS COLD AIR
PERSISTS THROUGH FRIDAY. HIGH PRESSURE TRIES TO BUILD EAST AND
FLOW AROUND THE HIGH COULD KEEP SOME MOISTURE ACROSS THE REGION
AND HAVE OPTED TO KEEP SOME FLURRIES. THIS HIGH PRESSURE WILL
PROGRESS EAST AND THEN WE START LOOKING AT THE NEXT SYSTEM MOVING
IN FOR THE WEEKEND. RIGHT NOW THERE CONTINUES TO BE A FAIR AMOUNT
OF UNCERTAINTY IN THE MODELS AT THIS POINT ON EXACTLY WHERE THE
ACCESS OF BEST QPF LINES UP. THAT SAID THE PROFILES ALSO SUPPORT
SNOW TO MIX AND RAIN THROUGH THE DAY ON SATURDAY. THERE CONTINUES
TO BE QUESTION AS TO PRECIP TYPE ALONG WITH HOW MUCH RAIN. THE
CONCERN WOULD CONTINUE TO BE HOW MUCH RAIN AND HOW MUCH SNOW
LINGERS GIVEN COLD TEMPERATURES UP TO THIS. RIGHT NOW KEPT CLOSE
TO SUPERBLEND IN THIS PART OF LONG TERM UNTIL BETTER AGREEMENTCAN
BE SEEN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 632 PM EST MON FEB 16 2015
EXPECT SOME LINGERING CEILINGS ACROSS MOST OF THE TAF SITES THIS
EVENING AS THIS WINTER STORM BEGINS TO EXIT OUT OF OUR AREA
TONIGHT. CIGS WILL SLOWLY LIFT THROUGH THE EVENING BUT WONT GET
ABOVE MVFR CONDITIONS AS SOME LINGERING LOW LEVEL DECKS WILL HANG
BEHIND THIS SYSTEM INTO TOMORROW. A FEW INSTANCES OF REDUCED
VISIBILITY WILL LINGER AS WELL AS THE LAST OF THE SNOW MOVES OUT
AS WELL. WINDS WILL CONTINUE TO BE LIGHT AND VARIABLE WITH THIS
SYSTEM AS IT MOVES OUT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR KYZ044-
050>052-058>060-068-069-079-080-083>086-104-106-108-111-114-116.
WINTER STORM WARNING UNTIL 3 AM EST TUESDAY FOR KYZ087-088-107-
109-110-112-113-115-117>120.
&&
$$
UPDATE...JP
SHORT TERM...JP
LONG TERM...DJ
AVIATION...SHALLENBERGER
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 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
932 PM EST MON FEB 16 2015
.SYNOPSIS...
LOW PRESSURE IS EXPECTED TO BRING ANOTHER ROUND OF SNOW TO THE
REGION OVERNIGHT...WITH HEAVIEST TOTALS TO THE SOUTH. SEVERAL
DISTURBANCES WILL KEEP COLD AND UNSETTLED WEATHER THROUGH THE
REMAINDER OF THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
OVERALL PATTERN IS WELL HANDLED BY FORECAST BUT DID MAKE SOME
TWEAKS. WITH THIS UPDATE...BRINGING AN END TO THE STEADY SNOW AN
HOUR OR TWO MORE QUICKLY THAN PREVIOUSLY FORECAST. EXTRAPOLATION
BRINGS BACK EDGE OF MAIN PRECIP THROUGH ZZV BY 04Z...PIT BY
06Z...AND MGW BY 09Z. RAP OMEGA/DEFORMATION FIELDS GIVE SOME ROUGH
AGREEMENT WITH THIS. ALSO REDUCED SNOW AMOUNTS A BIT ACROSS THE
NORTH...ESPECIALLY NORTH OF I-80 WHERE ACCUMULATION WILL BE TOUGH
TO COME BY. DID INCREASE SLIGHTLY NEAR I-70 WHERE MIDLEVEL
DEFORMATION CONTINUES TO FEED STRONGER RADAR RETURNS/HEAVIER SNOW
RATES. THIS BAND WILL SLOWLY MOVE SOUTHEAST OVER THE NEXT FEW
HOURS. CURRENT HEADLINES SEEM TO BE HANDLING THE SITUATION WELL
AND WILL NOT BE CHANGING AT THIS TIME. CL
PREVIOUS DISCUSSION FOR TUESDAY FOLLOWS...
WIDESPREAD SNOWFALL WILL BE OVER BY SUNRISE TUESDAY MORNING...BUT
WITH WINDS SHIFTING AROUND TO THE WEST...A BRIEF PERIOD OF UPSLOPE
SNOW SHOULD OCCUR IN THE WV/MD RIDGES. SNOWFALL TOTALS DURING THIS
TIME PERIOD SHOULD BE LESS THAN AN INCH. THERE SHOULD BE AT LEAST
SOME PARTIAL CLEARING LATE MORNING INTO EARLY AFTERNOON BEFORE THE
NEXT SYSTEM ADVANCES FROM THE WEST. DAYTIME TEMPERATURES TUESDAY
WILL BE RELATIVELY WARMER...WITH HIGHS RANGING FROM THE MID TEENS
TO THE MID 20S. ALTHOUGH THESE VALUES ARE STILL 15-20 DEGREES
COLDER THAN NORMAL...TUESDAY APPEARS AS IF IT WILL HAVE THE
WARMEST DAYTIME TEMPERATURES OF THE WORK WEEK.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/...
A POTENT SHORTWAVE WILL TRANSITION ACROSS THE FORECAST AREA
EARLY WEDNESDAY MORNING WITH THE NEXT SURGE OF ARCTIC AIR QUICKLY
RUSHING IN ON THE BACKSIDE OF THE TROUGH. NOT A GREAT DEAL OF
MOISTURE IS AVAILABLE WITH THIS FEATURE SO OVERALL SNOWFALL
AMOUNTS ARE FORECAST TO BE RELATIVELY LIGHT...WITH THE HIGHEST
AMOUNTS ALONG THE I80 CORRIDOR AND THE RIDGES. TEMPERATURES WILL
HAVE MINIMAL RECOVERY FROM MORNING LOWS ON WEDNESDAY...DROPPING
DOWN TO SUBZERO VALUES BY THURSDAY MORNING. WIND CHILL HEADLINES
LIKELY NEEDED AGAIN AS WITH THE MOST RECENT SYSTEM. FRIDAY MORNING
LOWS WILL APPROACH RECORDS AS WINDS DIMINISH AND COMBINATION OF
FRESH SNOW...LESS CLOUD COVERAGE...AND LIGHT WINDS OVERNIGHT WILL
ALLOW FOR MAX RADIATIONAL COOLING. MINIMAL CHANGE WAS NEEDED TO
THE INHERITED FORECAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
BY THURSDAY NIGHT SURFACE RIDGE OF HIGH PRESSURE WILL BUILD ACROSS
REGION WITH WINDS DIMINISHING AND CLEARING SKIES. WITH A BETTER
RADIATIONAL COOLING NIGHT RECORD LOW TEMPERATURES WELL BELOW ZERO
ARE EXPECTED FRIDAY MORNING.
SURFACE RIDGE WILL THEN SHIFT QUICKLY EAST SATURDAY AS UPPER LEVEL
FLOW BECOMES MORE ZONAL UNDER A DEEP CLOSED LOW ACROSS EASTERN
CANADA. TIMING DIFFERENCES BETWEEN MODELS WITH PIECES OF ENERGY IN
THIS FAST FLOW LEAD TO CHC POPS FOR SNOW SHOWERS FOR THE WEEKEND.
TEMPERATURES WILL MODERATE BUT CONTINUE BELOW SEASONAL AVERAGES.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
TERMINALS SOUTH OF PIT HAVE DETERIORATED TO IFR IN SNOW SHOWERS
WITH CIGS REMAINING MVFR. WILL EXPECT THESE TERMINALS TO CONTINUE
WITH IFR VISIBILITIES AND MVFR CIGS THROUGH THE DURATION OF THE
SNOW...ABOUT 05Z FOR ZZV AND ABOUT 10Z FOR LBE. SNOW WILL SLOWLY
TAPER DOWN WEST TO EAST BETWEEN 05-10Z FOR TERMINALS IN BETWEEN.
MVFR CIGS WILL REMAIN FOR THE EARLY PORTION OF TUESDAY BEFORE
CLOUDS BREAK AND LIFT BACK TO VFR TUESDAY AFTERNOON.
TAX
OUTLOOK.../TUESDAY THROUGH SATURDAY/...
THE BEST CHANCE FOR WIDESPREAD RESTRICTIONS WILL BE WEDNESDAY AND
WEDNESDAY NIGHT AS ANOTHER ARCTIC AIR MASS MOVES INTO THE REGION.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR MDZ001.
OH...WINTER WEATHER ADVISORY UNTIL 4 AM EST TUESDAY FOR OHZ057-068-
069.
PA...WINTER WEATHER ADVISORY UNTIL 4 AM EST TUESDAY FOR PAZ031-075.
WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR PAZ074-076.
WV...WINTER WEATHER ADVISORY UNTIL 4 AM EST TUESDAY FOR WVZ004-012-
021-022.
WINTER STORM WARNING UNTIL 7 AM EST TUESDAY FOR WVZ041.
WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR WVZ023.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
648 PM EST MON FEB 16 2015
.SYNOPSIS...
LOW PRESSURE IS EXPECTED TO BRING ANOTHER ROUND OF SNOW TO THE
REGION OVERNIGHT...WITH HEAVIEST TOTALS TO THE SOUTH. SEVERAL
DISTURBANCES WILL KEEP COLD AND UNSETTLED WEATHER THROUGH THE
REMAINDER OF THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
NO SIGNIFICANT CHANGES MADE...PREVIOUS FORECAST REMAINS LARGELY ON
TRACK. AS OF 6PM SNOW MADE IT INTO THE PGH METRO AREA AND WAS
SLOWLY OOZING NORTHWARD.
MODERATE TO HEAVY SNOW OVER SW OHIO ASSOCIATED WITH UPPER LEVEL
DEFORMATION WILL NEED TO BE MONITORED OVER THE NEXT SEVERAL HOURS.
THE LATEST HRRR HAS THIS UPPER LEVEL DEFORMATION OVERLAPPING THE
MID-LEVEL BAND THROUGH 04Z JUST SOUTH OF PGH. THIS OCCURS AS UPPER
LEVEL SUPPORT RAMPS UP IN THE FORM OF THE RIGHT ENTRANCE REGION OF
THE UPPER LEVEL JET STREAK. THESE SHOULD COMBINE TO ENHANCE
SNOWFALL...MAINLY SOUTH OF I-70 IN OUR FORECAST AREA OVERNIGHT.
THIS WILL BE MONITORED CLOSELY OVER THE NEXT 1-2HRS FOR POSSIBLE
ADVISORY EXPANSION.
TAX
PREVIOUS DISCUSSION BELOW...
LOW PRESSURE CURRENTLY OVER ALABAMA WILL TRACK OFF THE NORTH
CAROLINA COAST BY TUESDAY MORNING. THE MOISTURE FROM THIS SYSTEM
WILL EXTEND ALL THE WAY NORTH INTO THE OHIO VALLEY...BRINGING
SNOWFALL TONIGHT. CLEARLY...PRECIPITATION TYPE WILL NOT BE AN
ISSUE CONSIDERING THE RECENT TREND IN TEMPERATURES. THE SREF WAS
NOT USED IN THE FORECAST CONSIDERING IT WAS A HIGH OUTLIER
COMPARED TO ALL OTHER MODELS. TRIED TO STRIKE A BIT OF A
COMPROMISE CONSIDERING DIFFERENCES IN HIGH-RESOLUTION VERSUS
SYNOPTIC MODELS. ALTHOUGH THE TRACK OF THE STORM IS AGREED UPON BY
ALL MODELS...DIFFERENCES IN DEFORMATION AREA CAUSED SOME CONCERN
FOR SNOWFALL TOTALS. 12Z SYNOPTIC MODELS TRACKED SLIGHTLY FARTHER
TO THE SOUTH THAN 06Z MODEL RUNS...SHIFTING ALL
PRECIPITATION/SNOWFALL TOTALS FARTHER TO THE SOUTH. HOWEVER...THE
HIGH-RESOLUTION MODELS SUCH AS THE RAP/HRRR HAS TRACKED SLIGHTLY
SLOWER AND FARTHER TO THE WEST WITH THEIR DEFORMATION ZONES. IF
THESE SOLUTIONS TURNED OUT TO BE CORRECT...SNOWFALL WOULD LAST A
FEW HOURS LONGER AND FOCUS OF SNOW COULD BE SLIGHTLY FARTHER TO
THE WEST THAN DEPICTED BY THE SYNOPTIC MODELS. IN THE
END...CHANGES TO THE FORECAST WERE TO SLIGHTLY INCREASE SNOWFALL
ACROSS THE FORECAST AREA...BUT BY NO MORE THAN A HALF INCH TO AN
INCH. HAVE ALSO ADDED SNOW NORTH OF THE INTERSTATE 80
CORRIDOR...BUT AGAIN...KEPT SNOWFALL TOTALS LESS THAN A INCH. NO
CHANGES HAVE BEEN MADE TO THE ADVISORY/WARNING...BUT IF HRRR/RAP
FORECAST IS CORRECT...MOST LIKELY AREA THAT ADVISORY WOULD NEED TO
BE EXPANDED TO WOULD BE COUNTIES SUCH AS BELMONT...OHIO...AND
WASHINGTON. WITH EASTERLY WINDS OVERNIGHT...TYPICAL UPSLOPE SNOW
LOCATIONS WILL NOT BE THE FAVORED LOCATION FOR HIGHER THAN
FORECASTED SNOWFALL AMOUNTS.
WIDESPREAD SNOWFALL WILL BE OVER BY SUNRISE TUESDAY MORNING...BUT
WITH WINDS SHIFTING AROUND TO THE WEST...A BRIEF PERIOD OF UPSLOPE
SNOW SHOULD OCCUR IN THE WV/MD RIDGES. SNOWFALL TOTALS DURING THIS
TIME PERIOD SHOULD BE LESS THAN AN INCH. THERE SHOULD BE AT LEAST
SOME PARTIAL CLEARING LATE MORNING INTO EARLY AFTERNOON BEFORE THE
NEXT SYSTEM ADVANCES FROM THE WEST. DAYTIME TEMPERATURES TUESDAY
WILL BE RELATIVELY WARMER...WITH HIGHS RANGING FROM THE MID TEENS
TO THE MID 20S. ALTHOUGH THESE VALUES ARE STILL 15-20 DEGREES
COLDER THAN NORMAL...TUESDAY APPEARS AS IF IT WILL HAVE THE
WARMEST DAYTIME TEMPERATURES OF THE WORK WEEK.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/...
A POTENT SHORTWAVE WILL TRANSITION ACROSS THE FORECAST AREA
EARLY WEDNESDAY MORNING WITH THE NEXT SURGE OF ARCTIC AIR QUICKLY
RUSHING IN ON THE BACKSIDE OF THE TROUGH. NOT A GREAT DEAL OF
MOISTURE IS AVAILABLE WITH THIS FEATURE SO OVERALL SNOWFALL
AMOUNTS ARE FORECAST TO BE RELATIVELY LIGHT...WITH THE HIGHEST
AMOUNTS ALONG THE I80 CORRIDOR AND THE RIDGES. TEMPERATURES WILL
HAVE MINIMAL RECOVERY FROM MORNING LOWS ON WEDNESDAY...DROPPING
DOWN TO SUBZERO VALUES BY THURSDAY MORNING. WIND CHILL HEADLINES
LIKELY NEEDED AGAIN AS WITH THE MOST RECENT SYSTEM. FRIDAY MORNING
LOWS WILL APPROACH RECORDS AS WINDS DIMINISH AND COMBINATION OF
FRESH SNOW...LESS CLOUD COVERAGE...AND LIGHT WINDS OVERNIGHT WILL
ALLOW FOR MAX RADIATIONAL COOLING. MINIMAL CHANGE WAS NEEDED TO
THE INHERITED FORECAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
BY THURSDAY NIGHT SURFACE RIDGE OF HIGH PRESSURE WILL BUILD ACROSS
REGION WITH WINDS DIMINISHING AND CLEARING SKIES. WITH A BETTER
RADIATIONAL COOLING NIGHT RECORD LOW TEMPERATURES WELL BELOW ZERO
ARE EXPECTED FRIDAY MORNING.
SURFACE RIDGE WILL THEN SHIFT QUICKLY EAST SATURDAY AS UPPER LEVEL
FLOW BECOMES MORE ZONAL UNDER A DEEP CLOSED LOW ACROSS EASTERN
CANADA. TIMING DIFFERENCES BETWEEN MODELS WITH PIECES OF ENERGY IN
THIS FAST FLOW LEAD TO CHC POPS FOR SNOW SHOWERS FOR THE WEEKEND.
TEMPERATURES WILL MODERATE BUT CONTINUE BELOW SEASONAL AVERAGES.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
TERMINALS SOUTH OF PIT HAVE DETERIORATED TO IFR IN SNOW SHOWERS
WITH CIGS REMAINING MVFR. WILL EXPECT THESE TERMINALS TO CONTINUE
WITH IFR VISIBILITIES AND MVFR CIGS THROUGH THE DURATION OF THE
SNOW...ABOUT 05Z FOR ZZV AND ABOUT 10Z FOR LBE. SNOW WILL SLOWLY
TAPER DOWN WEST TO EAST BETWEEN 05-10Z FOR TERMINALS IN BETWEEN.
MVFR CIGS WILL REMAIN FOR THE EARLY PORTION OF TUESDAY BEFORE
CLOUDS BREAK AND LIFT BACK TO VFR TUESDAY AFTERNOON.
TAX
OUTLOOK.../TUESDAY THROUGH SATURDAY/...
THE BEST CHANCE FOR WIDESPREAD RESTRICTIONS WILL BE WEDNESDAY AND
WEDNESDAY NIGHT AS ANOTHER ARCTIC AIR MASS MOVES INTO THE REGION.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR MDZ001.
OH...WINTER WEATHER ADVISORY UNTIL 4 AM EST TUESDAY FOR OHZ057-068-
069.
PA...WINTER WEATHER ADVISORY UNTIL 4 AM EST TUESDAY FOR PAZ031-075.
WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR PAZ074-076.
WV...WINTER WEATHER ADVISORY UNTIL 4 AM EST TUESDAY FOR WVZ004-012-
021-022.
WINTER STORM WARNING UNTIL 7 AM EST TUESDAY FOR WVZ041.
WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR WVZ023.
&&
$$
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
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 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 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 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 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 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
1005 PM CST MON FEB 16 2015
.UPDATE...
ISSUED AT 955 PM CST MON FEB 16 2015
SHORTWAVE IN THE NORTHWEST FLOW ALOFT PRODUCED SOME HALF TO 1.5
INCH AMOUNTS OUT WEST. THIS FEATURE TO DIVE SOUTH OVERNIGHT WITH
REINFORCING COLD AIR AND STRENGTHENING WINDS FOR TUESDAY. WITH
VERY COLD TEMPERATURES...WILL NOT TAKE MUCH TO GET FLURRIES OR
PATCHY LIGHT SNOW. LIGHT SNOW HAS BEEN PATCHY OVER A COUPLE OF
COUNTIES AS IT DROPS SOUTH. FRONTOGENESIS INCREASES AS IT DROPS
SOUTH. THE HI RES MODELS CONFINE THE ACCUMULATING SNOW TO THE
SOUTHWEST PART OF OUR FORECAST AREA AND THE NEW NAM BRUSHES THE
WESTERN COUNTIES AS WELL. WILL MAINTAIN SOME LIGHT ACCUMULATIONS
FOR THE WESTERN/SOUTHWEST AREAS OVERNIGHT. SOME OF THE LIGHT SNOW
AND FLURRIES MAY CONTINUE INTO TUESDAY.
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 300 PM CST MON FEB 16 2015
THE PRIMARY FORECAST CONCERN IS POTENTIAL FOR A BAND OF ACCUMULATING
SNOW ACROSS PARTS OF EASTERN NEBRASKA TONIGHT.
UPPER AIR CHARTS FROM 12Z HAD THE FOLLOWING MAIN FEATURES. A STRONG
JETSTREAM WAS NOTED AT 300 MB FROM ALBERTA INTO UTAH...WITH A
COUPLE OF JET SEGMENTS OF OVER 130 KNOTS. A STRONGER JET SEGMENT
OF AROUND 170 KNOTS WAS OVER PENNSYLVANIA. A BROAD AREA OF 12 HOUR
HEIGHT FALLS OF 50 METERS OR MORE AT 500 MB EXTENDED FROM UTAH TO
IOWA AND FROM SOUTH DAKOTA TO TEXAS. A STRONG RIDGE WAS LOCATED
FROM OFF THE CALIFORNIA COAST UP INTO THE YUKON. WINDS WERE
GENERALLY FROM THE NORTHWEST IN THE LOWER AND MIDDLE TROPOSPHERE
FROM OUR AREA NORTHWEST INTO CANADA. PREVIOUSLY MENTIONED 500 MB
RIDGE TO OUR WEST WILL BUILD EAST AND THEN FLATTEN THROUGH
THURSDAY...WHILE A CLOSED LOW FORMS AND DROPS SOUTHEAST ACROSS
ONTARIO AND INTO THE EASTERN GREAT LAKES REGION.
A FAST MOVING SHORTWAVE IN COMBINATION WITH A COMPACT LOW PRESSURE
CENTER SHOULD BRING A BAND OF LIGHT SNOW TO THE REGION TONIGHT.
THE EXACT PLACEMENT OF THIS BAND IS SOMEWHAT UNCERTAIN...BUT THE
LATEST MODEL CONSENSUS (USING A BLEND OF 12Z NAM...18Z NAM...19Z
13 KM RAP ...18Z HRRR AND 15Z SREF MEAN) PLACES THE AXIS FROM
PARTS OF NORTH CENTRAL NEBRASKA INTO NORTHEAST KANSAS. BEST
POTENTIAL IS LIKELY JUST NORTH AND NORTHEAST OF THE TRACK OF THE
SURFACE LOW PRESSURE CENTER. SOUNDINGS...MID LEVEL FRONTOGENESIS
AND IMPRESSIVE 700 MB OMEGA VALUES IN THE DENDRITIC GROWTH ZONE
FROM THE NAM SUGGEST THE ATMOSPHERE MAY PRODUCE SOME AMOUNTS OVER
ONE INCH IN PARTS OF CENTRAL OR SOUTHEAST NEBRASKA DOWN INTO
NORTHEAST KANSAS. BUT WE HAVE MAX AMOUNTS AROUND ONE INCH FOR NOW
AND WILL MENTION THE LOCALIZED POTENTIAL FOR HIGHER AMOUNTS IN THE
HWO. THAT SYSTEM SHOULD PUSH QUICKLY SOUTH OUT OF OUR AREA BY
ABOUT SUNRISE...BUT SOME ISOLATED TO SCATTERED SNOW SHOWERS MAY
OCCUR INTO THE AFTERNOON HOURS. AFTER THAT...SNOW CHANCES SEEM LOW
FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...BUT A SLIGHT CHANCE
OF SNOW WILL RETURN BY THURSDAY.
COLD CANADIAN HIGH PRESSURE WILL BE BUILDING SOUTH FROM ALBERTA
AND SASKATCHEWAN THROUGH WEDNESDAY. WIND CHILLS MAY REACH NEAR
ADVISORY VALUES IN THE NORTH AND NORTHEAST PARTS OF THE FORECAST
AREA LATE TUESDAY NIGHT AND WEDNESDAY MORNING...BUT WILL NOT ISSUE
AN ADVISORY AT THIS POINT. THEN AS THE RIDGE MOVES OFF TO THE
SOUTHEAST AND SOUTHERLY RETURN FLOW DEVELOPS...TEMPERATURES WILL
MODERATE A BIT.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 300 PM CST MON FEB 16 2015
500 MB RIDGE WILL DEVELOP AGAIN FROM THE EASTERN PACIFIC UP INTO
THE YUKON FROM THURSDAY NIGHT INTO SUNDAY. LATEST RUNS OF THE
GFS... ECMWF AND CANADIAN MODELS AGREE ON THE GENERAL LARGE SCALE
FEATURES INTO SUNDAY. DETAILS START TO DIVERGE EARLY NEXT
WEEK...AND CONFIDENCE FALLS TO BELOW NORMAL BY THAT TIME. HAD TO
INCLUDE SOME LOW POPS FOR LIGHT SNOW CHANCES MUCH OF THIS PERIOD.
FRIDAY LOOKS LIKE THE WARMEST DAY...WHEN WE SHOULD SEE HIGHS IN
THE 40S WEST AND 30S EAST. LOWS WILL BE MOSTLY IN THE TEENS...BUT
UPPER TEENS TO MID 20S FOR FRIDAY NIGHT.
&&
.AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 515 PM CST MON FEB 16 2015
VFR CONDITIONS INITIALLY...THEN EXPECT MVFR CONDITIONS TO DEVELOP
ALONG WITH SOME LIGHT SNOW AS A WEATHER DISTURBANCE MOVES THROUGH
TONIGHT. WILL MONITOR RADAR TRENDS AS UNSURE HOW FAR EAST THE
BAND OF SNOW WILL MAKE IT. FOR NOW...INCLUDED PERIODS OF MVFR CIGS
AT KOFK/KLNK MAINLY BETWEEN 05Z-13Z AND -SN MENTION AT KLNK
BETWEEN 08Z AND 12Z. VFR CONDITIONS SHOULD RETURN WITH INCREASING
NORTHWEST WINDS 10-20KTS WITH GUSTS 25-30KTS BEGINNING 16-18Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...ZAPOTOCNY
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
515 PM CST MON FEB 16 2015
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 300 PM CST MON FEB 16 2015
THE PRIMARY FORECAST CONCERN IS POTENTIAL FOR A BAND OF ACCUMULATING
SNOW ACROSS PARTS OF EASTERN NEBRASKA TONIGHT.
UPPER AIR CHARTS FROM 12Z HAD THE FOLLOWING MAIN FEATURES. A STRONG
JETSTREAM WAS NOTED AT 300 MB FROM ALBERTA INTO UTAH...WITH A
COUPLE OF JET SEGMENTS OF OVER 130 KNOTS. A STRONGER JET SEGMENT
OF AROUND 170 KNOTS WAS OVER PENNSYLVANIA. A BROAD AREA OF 12 HOUR
HEIGHT FALLS OF 50 METERS OR MORE AT 500 MB EXTENDED FROM UTAH TO
IOWA AND FROM SOUTH DAKOTA TO TEXAS. A STRONG RIDGE WAS LOCATED
FROM OFF THE CALIFORNIA COAST UP INTO THE YUKON. WINDS WERE
GENERALLY FROM THE NORTHWEST IN THE LOWER AND MIDDLE TROPOSPHERE
FROM OUR AREA NORTHWEST INTO CANADA. PREVIOUSLY MENTIONED 500 MB
RIDGE TO OUR WEST WILL BUILD EAST AND THEN FLATTEN THROUGH
THURSDAY...WHILE A CLOSED LOW FORMS AND DROPS SOUTHEAST ACROSS
ONTARIO AND INTO THE EASTERN GREAT LAKES REGION.
A FAST MOVING SHORTWAVE IN COMBINATION WITH A COMPACT LOW PRESSURE
CENTER SHOULD BRING A BAND OF LIGHT SNOW TO THE REGION TONIGHT.
THE EXACT PLACEMENT OF THIS BAND IS SOMEWHAT UNCERTAIN...BUT THE
LATEST MODEL CONSENSUS (USING A BLEND OF 12Z NAM...18Z NAM...19Z
13 KM RAP ...18Z HRRR AND 15Z SREF MEAN) PLACES THE AXIS FROM
PARTS OF NORTH CENTRAL NEBRASKA INTO NORTHEAST KANSAS. BEST
POTENTIAL IS LIKELY JUST NORTH AND NORTHEAST OF THE TRACK OF THE
SURFACE LOW PRESSURE CENTER. SOUNDINGS...MID LEVEL FRONTOGENESIS
AND IMPRESSIVE 700 MB OMEGA VALUES IN THE DENDRITIC GROWTH ZONE
FROM THE NAM SUGGEST THE ATMOSPHERE MAY PRODUCE SOME AMOUNTS OVER
ONE INCH IN PARTS OF CENTRAL OR SOUTHEAST NEBRASKA DOWN INTO
NORTHEAST KANSAS. BUT WE HAVE MAX AMOUNTS AROUND ONE INCH FOR NOW
AND WILL MENTION THE LOCALIZED POTENTIAL FOR HIGHER AMOUNTS IN THE
HWO. THAT SYSTEM SHOULD PUSH QUICKLY SOUTH OUT OF OUR AREA BY
ABOUT SUNRISE...BUT SOME ISOLATED TO SCATTERED SNOW SHOWERS MAY
OCCUR INTO THE AFTERNOON HOURS. AFTER THAT...SNOW CHANCES SEEM LOW
FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...BUT A SLIGHT CHANCE
OF SNOW WILL RETURN BY THURSDAY.
COLD CANADIAN HIGH PRESSURE WILL BE BUILDING SOUTH FROM ALBERTA
AND SASKATCHEWAN THROUGH WEDNESDAY. WIND CHILLS MAY REACH NEAR
ADVISORY VALUES IN THE NORTH AND NORTHEAST PARTS OF THE FORECAST
AREA LATE TUESDAY NIGHT AND WEDNESDAY MORNING...BUT WILL NOT ISSUE
AN ADVISORY AT THIS POINT. THEN AS THE RIDGE MOVES OFF TO THE
SOUTHEAST AND SOUTHERLY RETURN FLOW DEVELOPS...TEMPERATURES WILL
MODERATE A BIT.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 300 PM CST MON FEB 16 2015
500 MB RIDGE WILL DEVELOP AGAIN FROM THE EASTERN PACIFIC UP INTO
THE YUKON FROM THURSDAY NIGHT INTO SUNDAY. LATEST RUNS OF THE
GFS... ECMWF AND CANADIAN MODELS AGREE ON THE GENERAL LARGE SCALE
FEATURES INTO SUNDAY. DETAILS START TO DIVERGE EARLY NEXT
WEEK...AND CONFIDENCE FALLS TO BELOW NORMAL BY THAT TIME. HAD TO
INCLUDE SOME LOW POPS FOR LIGHT SNOW CHANCES MUCH OF THIS PERIOD.
FRIDAY LOOKS LIKE THE WARMEST DAY...WHEN WE SHOULD SEE HIGHS IN
THE 40S WEST AND 30S EAST. LOWS WILL BE MOSTLY IN THE TEENS...BUT
UPPER TEENS TO MID 20S FOR FRIDAY NIGHT.
&&
.AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 515 PM CST MON FEB 16 2015
VFR CONDITIONS INITIALLY...THEN EXPECT MVFR CONDITIONS TO DEVELOP
ALONG WITH SOME LIGHT SNOW AS A WEATHER DISTURBANCE MOVES THROUGH
TONIGHT. WILL MONITOR RADAR TRENDS AS UNSURE HOW FAR EAST THE
BAND OF SNOW WILL MAKE IT. FOR NOW...INCLUDED PERIODS OF MVFR CIGS
AT KOFK/KLNK MAINLY BETWEEN 05Z-13Z AND -SN MENTION AT KLNK
BETWEEN 08Z AND 12Z. VFR CONDITIONS SHOULD RETURN WITH INCREASING
NORTHWEST WINDS 10-20KTS WITH GUSTS 25-30KTS BEGINNING 16-18Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...ZAPOTOCNY
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 RALEIGH NC
1050 PM EST MON FEB 16 2015
.SYNOPSIS...A LOW PRESSURE SYSTEM WILL STRENGTHEN OVER THE SOUTHEAST
U.S. OVERNIGHT...AND TRACK NORTHEAST ALONG THE CAROLINA COAST EARLY
TUESDAY MORNING.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 1050 PM MONDAY...
...CONDITIONS DETERIORATING ACROSS CENTRAL NC WITH WIDESPREAD
HAZARDOUS TRAVEL AND NUMEROUS POWER OUTAGES LIKELY...
...WINTER STORM WARNINGS AND WINTER WEATHER ADVISORY REMAIN IN
EFFECT...
HAVE UPGRADED THE FAR SE COUNTIES TO A WARNING AS THE NORTHERN
SECTIONS OF THESE COUNTIES HAVE THE POTENTIAL TO MEET OR EXCEED A
QUARTER OF AN INCH ICE ACCRUAL. TEMPS IN THIS REGION HOLDING IN THE
UPPER 20S AND WILL LIKELY REMAIN AT OR BELOW 30 DEGREES...ESPECIALLY
NORTH OF A CLINTON-FAYETTEVILLE-LAURINBURG LINE.
AREA SOUNDINGS AND LATEST HRRR SOUNDING DATA STILL DEPICT A DECENT
COLD NOSE -8 TO -10 DEGREES C WITH AN EQUALLY IMPRESSIVE WARM NOSE
OF 7 DEGREES C NEAR FAYETTEVILLE. STILL APPEARS THAT BULK OF PRECIP
WILL BE FREEZING RAIN OR A MIXTURE OF SLEET/FREEZING RAIN (DEPENDENT
ON PRECIP INTENSITY). THE LONGER THE PRECIP REMAINS MIXED...THE LESS
ICE ACCRETION WILL OCCUR BUT STILL ENOUGH TO CREATE DANGEROUS ICE
ACCRUAL ON POWERLINES AND TREES. IF PRECIP WERE TO GO MORE TOWARD
ALL SLEET...SLEET ACCUMULATION OF AN INCH OR LITTLE MORE WILL OCCUR
AND ICE ACCRUAL WILL BE SEVERELY LIMITED.
WILL MAINTAIN WARNING ELSEWHERE BUT HAVE LOWERED "MAXIMUM" ICE
ACCRUAL BELOW A HALF INCH. -WSS
820 PM UPDATE...
PRECIP COVERAGE AND INTENSITY WILL BE INCREASING EXPOTENTIALLY NEXT
FEW HOURS AS S/W AND ATTENDANT SFC LOW LIFTS E-NE OUT OF THE LOWER
MS VALLEY INTO THE DEEP SOUTH. THE SFC LOW...PER 23Z HRRR
MODEL...STILL PROJECTED TO TRACK IMMEDIATELY SOUTH-SE OF CENTRAL NC
OVERNIGHT.
00Z GSO SOUNDING DEPICTS SOME IMPRESSIVE DATA...ESPECIALLY THE 75KT
JET AT 6K FT. THIS JET PULLING WARMER AIR ALOFT OVER THE
REGION...CAUSING THE PRECIPITATION TYPE TO TRANSITION OVER TO MOSTLY
FREEZING RAIN SOUTH OF HIGHWAY 64...TO A MIXTURE OF SLEET/FREEZING
RAIN ACROSS THE NORTHERN PIEDMONT-NORTHERN/CENTRAL COASTAL PLAIN.
APPEARS MIXTURE SNOW/SLEET STILL FEASIBLE OVER THE FAR NORTHERN
TRIAD AND THE VIRGINIA BORDER COUNTIES THROUGH 10 PM-MIDNIGHT...BUT
EVEN HERE...APPEARS THAT FREEZING RAIN MIXED WITH SLEET WILL BE THE
DOMINATE PRECIP OVERNIGHT.
STILL APPEARS BULK OF PRECIPITATION WILL OCCUR BETWEEN 10 PM - 5
AM....WHEN BEST LIFT OCCURS IN CONJUNCTION WITH A 140KT JET LIFTING
NE ACROSS VA.
HAVE SEVERELY CUTBACK ON SNOW AMOUNTS ACROSS THE NORTHERN PIEDMONT
AND INCREASED ICING POTENTIAL IN VICINITY OF THE TRIAD. THE ICING
NUMBERS IN THE NW PIEDMONT MAY NEED TO BE ADJUSTED UPWARD AS NEW
DATA ARRIVES.
STILL APPEARS THAT A THREAT FOR A DEVASTATING ICE STORM IS A VERY
REAL POSSIBILITY IN A WEST-EAST BAND ACROSS SECTIONS OF PIEDMONT,
SANDHILLS AND COASTAL PLAIN. THIS THREAT APPEARS GREATEST IN
VICINITY OR JUST SOUTH OF HIGHWAY 64. STILL...AMOUNTS WILL BE
DEPENDENT UPON WHETHER PRECIP REMAINED MIXED OR PREDOMINATELY ONE OR
THE OTHER. THE MORE MIXTURE WE RECEIVE...ICE ACRRUAL AMOUNTS WILL BE
A LITTLE LESS. ALSO...IF PRECIPITATION FALLS MODERATE OR
HEAVILY...THIS WOULD LIMIT ICE ACCRUAL AS WELL. NEEDLESS TO
SAY...WITH TEMPERATURES IN THE 20S...ANY TYPE OF PRECIP THAT FALLS
WILL QUICKLY MAKE ROADS SLICK AND BECOMING QUITE
HAZARDOUS.
HAVE ALSO ADJUSTED ICING AMOUNTS IN THE FAR SE AS IT APPEARS ICE
ACCRUAL IN THIS REGION MAY BE A LITTLE LESS AS TEMPS HOVER NEAR OR
JUST BELOW FREEZING...LIMITING ICE ACCRETION.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 325 PM MONDAY...
A SHORTWAVE RESULTING FROM A MERGER OF A WAVE CURRENTLY DIVING
THROUGH THE ROCKIES AND THE SHEARING LOW OVER THE CALIFORNIA
BAJA...WILL ROUND THE BASE OF THE FULL-LATITUDE TROUGH AND CROSS THE
SOUTHEAST US TUESDAY NIGHT. DEEP MOISTURE AND THE SYNOPTIC FRONTAL
ZONE WILL BE OFFSHORE BY THEN...SO IT APPEARS THE RESULTING SURFACE
LOW AND PRECIP WILL ALSO BE OFFSHORE AS WELL. LOWS IN THE UPPER
TEENS TO MID 20S.
A SPEED MAX AND ASSOCIATED VORTICITY WILL DIVE THROUGH THE BACK SIDE
OF THE DEEP UPPER TROUGH AND CROSS THE AREA ON WEDNESDAY. FORECAST
SOUNDINGS SHOW SUFFICIENT MOISTURE FOR ICE IN THE -10 TO -20C
LAYER...WHICH ITSELF IS PRETTY LOW IN THIS ARCTIC AIRMASS. Q-VECTOR
CONVERGENCE INCREASE WEDNESDAY AFTERNOON...AND COMBINED WITH STEEP
LOW-LEVEL LAPSE RATES AND SOME WEAK INSTABILITY...SEEMS TO BE ENOUGH
SUPPORT FOR A LOW-END CHANCE OF SNOW SHOWERS AS THE NEXT ARCTIC
FRONT PLOWS THROUGH THE AREA. IF THESE SNOW SHOWERS WERE TO
DEVELOP...THERE COULD BE SOME TRAVEL CONCERNS GIVEN HOW COLD GROUND
TEMPERATURES WILL CONTINUE TO BE. HOWEVER...RATES WOULD NEED TO BE
HIGH AND CONFIDENCE IS VERY LOW AT THIS POINT. HIGHS WEDNESDAY ONLY
INT HE LOW TO MID 30S.
THE STRONG ARCTIC FRONT WILL BE EAST OF THE AREA WEDNESDAY NIGHT AND
THICKNESSES ARE FORECAST TO PLUMMET TO SOMEWHERE IN THE NEIGHBORHOOD
OF 1220M BOTH THURSDAY AND FRIDAY MORNING AS STRONG HIGH PRESSURE
SETTLES OVER HEAD BY FRIDAY. THE GFS IS MUCH COLDER THAN THE ECMWF
WITH 1200M...A VALUE THAT APPEARS TO HAVE BEEN REACH ONLY A COUPLE
TIMES IN THE PAST 50 YEARS. EVEN WITH THE WARMER ECMWF...LOWS WILL
BE IN THE LOW TI MID SINGLE DIGIT RANGE...AND A NEGATIVE TEMP CANT
BE RULED OUT AT THIS POINT. HIGHS THURSDAY LOOK TO ONLY BE IN THE
UPPER TEENS TO MID 20S BASED ON THICKNESS SCHEMES AND DRY ADIABATIC
MIXING. SLIGHTLY WARMER ON FRIDAY IN THE MID 20S TO LOWER 30S.THIS
WILL VERY LIKELY BE RECORD BREAKING COLD THAT WILL WARRANT SOME
PREPARATIONS AND EXTRA PRECAUTIONS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
AS OF 325 PM MONDAY...
...RECORD BREAKING AND DANGEROUSLY COLD CONDITIONS FOR THE SECOND
HALF OF THE WEEK...
THE PATTERN SHIFTS A LITTLE OVER THE WEEKEND AS THE UPPER LOW NEAR
THE HUDSON BAY FILLS IN AND THE UPPER LEVEL FLOW OVER THE SOUTHERN
US TURNS TO SOUTHWESTERLY. MODELS ARE SUGGESTIVE OF A SYSTEM
LIFTING FROM THE SOUTHWEST US THROUGH TOWARD THE MIDWEST.
HOWEVER...THE ECWMF AND GFS SHOW MARKEDLY DIFFERENTLY SOLUTIONS.
THE ECMWF SHOWS A STORM TRACK THROUGH THE OHIO VALLEY WHILE THE GFS
LINGERS THE ARCTIC FRONT NEAR OUR LATITUDE AND HAS A COUPLE "OVER-
RUNNING" EVENTS THAT COULD CAUSE SOME WINTRY WEATHER. GIVEN THE
IMPENDING STORM AND UNCERTAINTY...HAVE LEANED ON WPC FOR THIS PERIOD
WITH BASICALLY A CHANCE POPS THROUGH THE LATTER HALF OF THE WEEKEND
AND HIGHS REBOUNDING INTO THE UPPER 30S AND 40S.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 707 PM MONDAY...
CONDITIONS WILL DETERIORATE RAPIDLY BETWEEN 00 TO 03Z...WITH
WIDESPREAD IFR CEILINGS IN A WINTRY MIX OVERSPREADING THE AREA
THROUGH THE OVERNIGHT HOURS...ENDING 10-14Z WEST TO EAST.
PREDOMINATE P-TYPE AT KINT AND KGSO WILL BE SLEET...MIXING WITH A
SOME FREEZING RAIN. AT KRDU AND KRWI...THE PREDOMINATE P-TYPE WILL
BE FREEZING RAIN. KFAY COULD SEE MULTIPLE CHANGE-OVERS...WITH PRECIP
BEGIN AS FZRA...POTENTIALLY CHANGING OVER TO RAIN AOA 06Z...AND THEN
CHANGING BACK TO FZRA OR FZDZ BEFORE ENDING.
GRADUAL IMPROVEMENT WILL BEGIN AFTER 12Z TUES... WITH ALL SITES
EXPECTED TO BECOME MVFR AND POSSIBLY VFR TUES AFTERNOON.
ANOTHER STRONG ARCTIC COLD FRONT MAY BRING A BRIEF PERIOD OF MVFR
CEILINGS WITH SNOW SHOWERS WEDNESDAY AFTERNOON AND EVENING. HIGH
PRESSURE WILL BRING A HIGH LIKELIHOOD OF VFR CONDITIONS THURSDAY AND
FRIDAY... BEFORE ANOTHER SYSTEM POTENTIALLY IMPACTS THE AREA ON
SATURDAY.
&&
.CLIMATE...
...THE FOLLOWING ARE RECORD LOW AND LOW MAXIMUM TEMPERATURES FOR
FEBRUARY 16TH...19TH...AND 20TH...FOR GSO...RDU...AND FAY...
RECORD LOWS
GSO RDU FAY
FEBRUARY 16: 8 IN 1905 11 IN 1905 17 IN 1991
FEBRUARY 19: 12 IN 1979 11 IN 1979 8 IN 1958
FEBRUARY 20: 14 IN 1934 13 IN 1979 12 IN 1958
RECORD LOW MAXIMUMS
GSO RDU FAY
FEBRUARY 16: 27 IN 1958 30 IN 1943 33 IN 1943
FEBRUARY 19: 32 IN 1958 31 IN 1903 26 IN 1979
FEBRUARY 20: 29 IN 1947 32 IN 1947 37 IN 1972
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON EST TUESDAY FOR NCZ011-027-028-042-043-
077-078-085-088-089.
WINTER STORM WARNING UNTIL 9 AM EST TUESDAY FOR NCZ007>010-021>026-
038>041-073>076-083-084.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...BLS
LONG TERM...BLS
AVIATION...CBL
CLIMATE...RAH
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
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
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 STATE COLLEGE PA
819 PM EST MON FEB 16 2015
.SYNOPSIS...
LOW PRESSURE WILL TRACK SOUTH OF THE REGION TONIGHT AND EARLY
TUESDAY FOLLOWED BY ANOTHER BLAST OF ARCTIC AIR THAT WILL MOVE
INTO THE REGION FOR THE MID TO LATE WEEK PERIOD.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
RADAR AND SFC OBS INDICATE LIGHT SNOW HAS OVERSPREAD THE SOUTHERN
TIER COUNTIES OF CENTRAL PA AS OF 01Z. LIGHT SNOW WILL MARCH
NORTHWARD OVERNIGHT...AS SFC WAVE PASSES SOUTH OF PA. LATEST 4KM
NAM AND HRRR SUGGESTS THE SNOW WILL GET TO ARND I-80 BY 03Z...THEN
REACH IT/S NORTHERNMOST EXTENT ACROSS THE N MTNS BY MIDNIGHT.
BEST 850-700MB FRONTOGENETIC FORCING IN MDLS SUGGESTS THE AXIS OF
HEAVIEST SNOW WILL BE SOUTH OF THE PA-MD BORDER...WITH PERHAPS FAR
SRN LANCASTER-YORK COUNTIES PICKING UP SLIGHTLY HIGHER AMOUNTS AS
THE BEST WARM ADVECTION/FRONTOGENESIS MOVES THROUGH OVERNIGHT.
SREF/GEFS SUPPORT CONFINING QPF OF HALF INCH OR MORE SOUTH OF THE
BORDER...LEADING TO A HIGH CONFIDENCE OF A MAINLY LIGHT SNOWFALL.
BLENDED MDL QPF CONTINUES TO INDICATE ONLY ARND 0.20 INCHES ACROSS
THE S TIER...WITH ALMOST NOTHING OVR THE N MTNS. HOWEVER...AN
EXAMINATION OF MDL TIME SECTIONS INDICATES NEARLY ALL LIFT WITHIN
THE CLOUD LAYER FALLS WITHIN THE DENDRITIC GROWTH ZONE...IMPLYING
A HIGH SNOW/WATER RATIO OF CLOSE TO 20 TO 1. THEREFORE...SNOW
TOTALS OF NR 4 INCHES STILL SEEM PROBABLE ALONG THE MD BORDER.
WILL CONTINUE THE WINTER WEATHER ADVISORY WITH NO PLANNED CHANGES
AT THIS POINT IN TIME...FOR THE SOUTHERN 2 LAYERS OF COUNTIES IN
OUR CWA. THE SOUTHERN TIER IS EXPECTED TO SEE BETWEEN 2 AND 4 INCHES
OF SNOW BY THE MORNING COMMUTE TUESDAY...WHILE LESSER AMOUNTS OF
AROUND AN INCH ARE ANTICIPATED ALONG INTERSTATE 80 AND PERHAPS
A DUSTING OVR THE N MTNS.
PRECIP WILL BE TAPERING OFF IN THE HOURS JUST AFTER MIDNIGHT OVER
MY SWRN ZONES WITH MOST OF THE SNOW HAVING ENDED EVEN IN THE EAST
BY AROUND SUNRISE.
OVERNIGHT LOWS WILL AVERAGE IN THE SINGLE DIGITS...TO PERHAPS THE
LOWER TEENS OVER THE SE.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
THE BROAD AREA OF WEAK TO MDT ASCENT ASSOCIATED WITH THE COUPLED
UPPER JET WILL SCOOT QUICKLY EAST OF THE REGION TUESDAY MORNING
FOLLOWED BY WEST-SOUTHWESTERLY FLOW IN THE LOW TO MID
LEVELS...ALLOWING FOR SOME PARTIAL CLEARING IN THE AFTERNOON.
I FOLLOWED MOS POPS MOST CLOSELY LEADING TO A MAINLY DRY DAY FCST
FOR MOST AREAS. ANY LINGERING LGT SNOW OVER THE EASTERN COUNTIES
SHOULD END ARND OR SHORTLY AFTER 12Z.
TEMPS DURING THE DAY TUESDAY WILL WARM BY ANOTHER 10 DEG COMPARED
TO TODAY`S HIGHS. IT`S PRETTY AMAZING THAT EVEN AFTER THE
UPCOMING 2 DAYS OF MODERATING TEMPS...HIGHS TUESDAY WILL STILL BE
15-20 DEG BELOW NORMAL FOR THE DATE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
VERY COLD AIR WILL CONTINUE TO IMPACT THE REGION THROUGH AT LEAST
THE UPCOMING WORK-WEEK AS A STRONG UPPER LEVEL RIDGE REMAINS OVER
THE WESTERN U.S. AND CONTINUES TO DIRECT POLAR AIR INTO THE
EASTERN U.S. VIA PERSISTENT TROUGH.
SHORT WAVE ENERGY IS FORECAST TO CROSS THE INTO THE PAC LATE IN
THE WEEK AND DIG INTO THE FOUR CORNERS REGION AS THE UPPER RIDGE
REBUILDS NWD INTO WRN CANADA. THIS WILL SHIFT THE UPPER TROF AXIS
NOW COVERING THE EASTERN U.S. - WESTWARD. THIS IN TURN WILL LEAD
TO A FLATTENING OF THE UPPER FLOW OVER THE NORTHEAST NEXT WEEKEND
AND A MODERATION AWAY FROM THE BITTER COLD IN THE CURRENT PATTERN.
PRIOR TO THIS LATE WEEK...LARGE SCALE FLOW MODIFICATION WE`LL HAVE
TO DEAL WITH ONE MORE ARCTIC BLAST...THE LEADING EDGE OF WHICH
WILL PUSH ACROSS THE STATE DURING THE DAY WEDNESDAY. SOMEWHAT
SIMILAR TO SATURDAY...WE SEE A WELL-DEFINED AREA OF STEEP 850-500
MB LAPSE RATES AROUND...OR IN EXCESS OF 7C/KM THAT WILL MOVE
ACROSS THE WESTERN MTNS DURING THE EARLY TO MID AFTERNOON...AND
THROUGH THE SUSQ VALLEY EARLY WED EVENING. ALTHOUGH LIKELY NOT AS
EXTENSIVE AND CONSISTENTLY INTENSE OF A LINE THAT WE SAW SATURDAY
/COMPLETE WITH FEW FLASHES OF LIGHTNING IN SOME LOCATIONS/...THE
SQUALLS ASSOCIATED WITH THIS RIBBON OF INSTABILITY WED WILL LIKELY
COME IN THE FORM ONE OR TWO LINES...AND DUMP A QUICK .5 TO 1.5
INCHES OF SNOW - GREATLY IMPACTING TRAVEL FOR A SHORT PERIOD.
BEHIND THIS SYSTEM YET ANOTHER SURGE OF EXTREMELY COLD AIR WILL
SURGE ACROSS THE STATE FOR THE SECOND HALF OF THE WEEK.
SIMILAR...EXTREMELY COLD TEMPS AT 850 MB ARE FORECAST TO MOVE OVER
THE STATE THURSDAY AND FRIDAY /AND COULD BE EVEN A FEW DEG C LOWER
THAN THOSE ASSOCIATED WITH THIS PAST SUNDAY-MONDAY ARCTIC
AIRMASS/. 03Z SREF SHOWS MEAN 850 TEMPS OF -25 TO -28C COVERING
ALL OF CENTRAL PENN WHICH IS ABOUT -3 SIGMA. HIGH TEMPS THURSDAY
MAY STAY A FEW-SVRL DEG F BELOW ZERO AGAIN ACROSS THE NRN
MTNS...AND HOLD IN THE SINGLE DIGITS TO LOWER TEENS ACROSS THE
REST OF CENTRAL AND SRN PENN...BEFORE MODERATING BY 5-7 DEG
FRIDAY. MORNING LOWS THURSDAY AND FRIDAY COULD RIVAL THOSE OF
SUNDAY AND MONDAY MORNING.
THE CENTER OF THIS NEXT ARCTIC HIGH MAY SLIDE JUST SOUTH OF THE
REGION THEN OFF THE MID ATLANTIC COAST - PER THE 00Z EC...WHILE
THE GEFS WOULD SUGGEST A LITTLE MORE IN THE WAY OF LLVL COLD AIR
DAMMING OVER THE CWA...PRECEDING INCREASING MOISTURE AND A WINTRY
MIX OR SNOW SPREADING IN FROM THE SW...THEN ANOTHER PUSH OF
ARCTIC AIR FOR LATE SUNDAY AND MONDAY.
TEMPERATURES NEXT SUNDAY...HOWEVER...HOLD THE POTENTIAL TO RISE
ABOVE THE FREEZING MARK OVER A GOOD PART OF CENTRAL PA AS THE
EARLIER MENTIONED MODERATION IN THE UPPER FLOW IS FORECAST TO
ARRIVE. THE NEXT SHORTWAVE TROF IS ALSO CURRENTLY TIMED FOR NEXT
WEEKEND...LEADING TO THE POSSIBILITY OF SNOW OR RAIN FOR A CHANGE
OVER SRN PA AND SNOW OVER THEN NORTH.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
SNOW INTO JST...AS EXPECTED.
DID ADJUST TIMING SOME ELSEWHERE...SNOW RUNNING JUST A TAD
BEHIND.
EARLIER DISCUSSION BELOW.
STILL VFR...BUT EXPECT CONDITIONS TO DO DOWN FAST ONCE SNOW
STARTS...GIVEN THE DRY AIRMASS.
MINOR ADJUSTMENTS MADE TO 21Z TAFS.
EARLIER DISCUSSION BELOW.
VFR WITH NO SIG WX CONDITIONS THROUGH LATE AFTERNOON.
LOW PRESSURE MOVING NEWD FROM AL OFF THE MID ATLC COAST OVERNIGHT
WILL SPREAD SNOW AND IFR CONDS ACROSS THE SRN 1/2 OF THE
AIRSPACE LATER THIS AFTERNOON AND OVERNIGHT. SNOW WILL BE QUICK-
HITTING AND END BY 12-15Z TUESDAY FROM WEST TO EAST. HIGHEST
CONFIDENCE IN IFR IS OVER THE SRN AIRFIELDS. USED A BLEND OF HIGH
RES MDLS FOR TIMING WITH SNOW ONSET 21-00Z SPREADING FROM SW TO
NE.
OUTLOOK...
WED-THU...MVFR/IFR -SHSN WRN 1/3. VFR/MVFR -SHSN CENTRAL/ERN 2/3
FRI...BCMG VFR. NO SIG WX.
SAT...MVFR WITH SNOW SHOWERS ASSOC WITH AN APPROACHING COLD FRONT.
&&
.CLIMATE...
MOST OF THE FORECAST AREA WAS ZERO OR COLDER LAST NIGHT WITH
CHANDLER`S VALLEY BEING THE COLDEST COMING IN AT -32.
HARRISBURG AND WILLIAMSPORT BOTH TIED THEIR RECORD LOWS FOR THE
DATE. HARRISBURG WAS 0 AND WILLIAMSPORT WAS -5.
RECORD LOWS/YEAR
HARRISBURG.............0/1905
WILLIAMSPORT..........-5/1905
STATE COLLEGE.........-8/1904
YORK..................-7/1963
ALTOONA...............-2/2004
BRADFORD..............-23/1943
CLEARFIELD............-6/1930
JOHNSTOWN.............-10/1943
LANCASTER.............+2/1987
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR PAZ024>028-
033>036-056-057-059-063>066.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...GARTNER
AVIATION...LA CORTE/MARTIN
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
637 PM EST MON FEB 16 2015
.SYNOPSIS...
LOW PRESSURE WILL TRACK SOUTH OF THE REGION TONIGHT AND EARLY
TUESDAY FOLLOWED BY ANOTHER BLAST OF ARCTIC AIR THAT WILL MOVE
INTO THE REGION FOR THE MID TO LATE WEEK PERIOD.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
SFC OBS AND WEB CAMS INDICATE LIGHT SNOW HAS OVERSPREAD PORTIONS
OF SOMERSET...BEDFORD AND FULTON COUNTIES AS OF 22Z. LIGHT SNOW
WILL MARCH NORTHWARD OVERNIGHT...AS SFC WAVE PASSES SOUTH OF PA.
LATEST 4KM NAM AND HRRR SUGGESTS THE SNOW WILL GET TO ARND I-80
BY 03Z...THEN REACH IT/S NORTHERNMOST EXTENT ACROSS THE N MTNS BY
MIDNIGHT.
BEST 850-700MB FRONTOGENETIC FORCING IN MDLS SUGGESTS THE AXIS OF
HEAVIEST SNOW WILL BE SOUTH OF THE PA-MD BORDER...WITH PERHAPS FAR
SRN LANCASTER-YORK COUNTIES PICKING UP SLIGHTLY HIGHER AMOUNTS AS
THE BEST WARM ADVECTION/FRONTOGENESIS MOVES THROUGH OVERNIGHT.
SREF/GEFS SUPPORT CONFINING QPF OF HALF INCH OR MORE SOUTH OF THE
BORDER...LEADING TO A HIGH CONFIDENCE OF A MAINLY LIGHT-MODERATE
SNOWFALL. BLENDED MDL QPF CONTINUES TO INDICATE ONLY ARND 0.20
INCHES ACROSS THE S TIER...WITH ALMOST NOTHING OVR THE N MTNS.
HOWEVER...AN EXAMINATION OF MDL TIME SECTIONS INDICATES NEARLY ALL
LIFT WITHIN THE CLOUD LAYER FALLS WITHIN THE DENDRITIC GROWTH
ZONE...IMPLYING A HIGH SNOW/WATER RATIO OF CLOSE TO 20 TO 1.
THEREFORE...SNOW TOTALS OF NR 4 INCHES STILL SEEM PROBABLE ALONG
THE MD BORDER.
WILL CONTINUE THE WINTER WEATHER ADVISORY WITH NO PLANNED CHANGES
AT THIS POINT IN TIME...FOR THE SOUTHERN 2 LAYERS OF COUNTIES IN
OUR CWA. THE SOUTHERN TIER IS EXPECTED TO SEE BETWEEN 2 AND 4 INCHES
OF SNOW BY THE MORNING COMMUTE TUESDAY...WHILE LESSER AMOUNTS OF
AROUND AN INCH ARE ANTICIPATED ALONG INTERSTATE 80 AND PERHAPS
A DUSTING OVR THE N MTNS.
PRECIP WILL BE TAPERING OFF IN THE HOURS JUST AFTER MIDNIGHT OVER
MY SWRN ZONES WITH MOST OF THE SNOW HAVING ENDED EVEN IN THE EAST
BY AROUND SUNRISE.
OVERNIGHT LOWS WILL AVERAGE IN THE SINGLE DIGITS...TO PERHAPS THE
LOWER TEENS OVER THE SE.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
THE BROAD AREA OF WEAK TO MDT ASCENT ASSOCIATED WITH THE COUPLED
UPPER JET WILL SCOOT QUICKLY EAST OF THE REGION TUESDAY MORNING
FOLLOWED BY WEST-SOUTHWESTERLY FLOW IN THE LOW TO MID
LEVELS...ALLOWING FOR SOME PARTIAL CLEARING IN THE AFTERNOON.
I FOLLOWED MOS POPS MOST CLOSELY LEADING TO A MAINLY DRY DAY FCST
FOR MOST AREAS. THINKING IS THAT ANY LINGERING LIGHT SNOW SHOWERS
WILL BE CONFINED TO WESTERN HIGHER ELEVATIONS.
TEMPS DURING THE DAY TUESDAY WILL WARM BY ANOTHER 10 DEG COMPARED
TO TODAY`S HIGHS. IT`S PRETTY AMAZING THAT EVEN AFTER THE
UPCOMING 2 DAYS OF MODERATING TEMPS...HIGHS TUESDAY WILL STILL BE
15-20 DEG BELOW NORMAL FOR THE DATE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
VERY COLD AIR WILL CONTINUE TO IMPACT THE REGION THROUGH AT LEAST
THE UPCOMING WORK-WEEK AS A STRONG UPPER LEVEL RIDGE REMAINS OVER
THE WESTERN U.S. AND CONTINUES TO DIRECT POLAR AIR INTO THE
EASTERN U.S. VIA PERSISTENT TROUGH.
SHORT WAVE ENERGY IS FORECAST TO CROSS THE INTO THE PAC LATE IN
THE WEEK AND DIG INTO THE FOUR CORNERS REGION AS THE UPPER RIDGE
REBUILDS NWD INTO WRN CANADA. THIS WILL SHIFT THE UPPER TROF AXIS
NOW COVERING THE EASTERN U.S. - WESTWARD. THIS IN TURN WILL LEAD
TO A FLATTENING OF THE UPPER FLOW OVER THE NORTHEAST NEXT WEEKEND
AND A MODERATION AWAY FROM THE BITTER COLD IN THE CURRENT PATTERN.
PRIOR TO THIS LATE WEEK...LARGE SCALE FLOW MODIFICATION WE`LL HAVE
TO DEAL WITH ONE MORE ARCTIC BLAST...THE LEADING EDGE OF WHICH
WILL PUSH ACROSS THE STATE DURING THE DAY WEDNESDAY. SOMEWHAT
SIMILAR TO SATURDAY...WE SEE A WELL-DEFINED AREA OF STEEP 850-500
MB LAPSE RATES AROUND...OR IN EXCESS OF 7C/KM THAT WILL MOVE
ACROSS THE WESTERN MTNS DURING THE EARLY TO MID AFTERNOON...AND
THROUGH THE SUSQ VALLEY EARLY WED EVENING. ALTHOUGH LIKELY NOT AS
EXTENSIVE AND CONSISTENTLY INTENSE OF A LINE THAT WE SAW SATURDAY
/COMPLETE WITH FEW FLASHES OF LIGHTNING IN SOME LOCATIONS/...THE
SQUALLS ASSOCIATED WITH THIS RIBBON OF INSTABILITY WED WILL LIKELY
COME IN THE FORM ONE OR TWO LINES...AND DUMP A QUICK .5 TO 1.5
INCHES OF SNOW - GREATLY IMPACTING TRAVEL FOR A SHORT PERIOD.
BEHIND THIS SYSTEM YET ANOTHER SURGE OF EXTREMELY COLD AIR WILL
SURGE ACROSS THE STATE FOR THE SECOND HALF OF THE WEEK.
SIMILAR...EXTREMELY COLD TEMPS AT 850 MB ARE FORECAST TO MOVE OVER
THE STATE THURSDAY AND FRIDAY /AND COULD BE EVEN A FEW DEG C LOWER
THAN THOSE ASSOCIATED WITH THIS PAST SUNDAY-MONDAY ARCTIC
AIRMASS/. 03Z SREF SHOWS MEAN 850 TEMPS OF -25 TO -28C COVERING
ALL OF CENTRAL PENN WHICH IS ABOUT -3 SIGMA. HIGH TEMPS THURSDAY
MAY STAY A FEW-SVRL DEG F BELOW ZERO AGAIN ACROSS THE NRN
MTNS...AND HOLD IN THE SINGLE DIGITS TO LOWER TEENS ACROSS THE
REST OF CENTRAL AND SRN PENN...BEFORE MODERATING BY 5-7 DEG
FRIDAY. MORNING LOWS THURSDAY AND FRIDAY COULD RIVAL THOSE OF
SUNDAY AND MONDAY MORNING.
THE CENTER OF THIS NEXT ARCTIC HIGH MAY SLIDE JUST SOUTH OF THE
REGION THEN OFF THE MID ATLANTIC COAST - PER THE 00Z EC...WHILE
THE GEFS WOULD SUGGEST A LITTLE MORE IN THE WAY OF LLVL COLD AIR
DAMMING OVER THE CWA...PRECEDING INCREASING MOISTURE AND A WINTRY
MIX OR SNOW SPREADING IN FROM THE SW...THEN ANOTHER PUSH OF
ARCTIC AIR FOR LATE SUNDAY AND MONDAY.
TEMPERATURES NEXT SUNDAY...HOWEVER...HOLD THE POTENTIAL TO RISE
ABOVE THE FREEZING MARK OVER A GOOD PART OF CENTRAL PA AS THE
EARLIER MENTIONED MODERATION IN THE UPPER FLOW IS FORECAST TO
ARRIVE. THE NEXT SHORTWAVE TROF IS ALSO CURRENTLY TIMED FOR NEXT
WEEKEND...LEADING TO THE POSSIBILITY OF SNOW OR RAIN FOR A CHANGE
OVER SRN PA AND SNOW OVER THEN NORTH.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
SNOW INTO JST...AS EXPECTED.
DID ADJUST TIMING SOME ELSEWHERE...SNOW RUNNING JUST A TAD
BEHIND.
EARLIER DISCUSSION BELOW.
STILL VFR...BUT EXPECT CONDITIONS TO DO DOWN FAST ONCE SNOW
STARTS...GIVEN THE DRY AIRMASS.
MINOR ADJUSTMENTS MADE TO 21Z TAFS.
EARLIER DISCUSSION BELOW.
VFR WITH NO SIG WX CONDITIONS THROUGH LATE AFTERNOON.
LOW PRESSURE MOVING NEWD FROM AL OFF THE MID ATLC COAST OVERNIGHT
WILL SPREAD SNOW AND IFR CONDS ACROSS THE SRN 1/2 OF THE
AIRSPACE LATER THIS AFTERNOON AND OVERNIGHT. SNOW WILL BE QUICK-
HITTING AND END BY 12-15Z TUESDAY FROM WEST TO EAST. HIGHEST
CONFIDENCE IN IFR IS OVER THE SRN AIRFIELDS. USED A BLEND OF HIGH
RES MDLS FOR TIMING WITH SNOW ONSET 21-00Z SPREADING FROM SW TO
NE.
OUTLOOK...
WED-THU...MVFR/IFR -SHSN WRN 1/3. VFR/MVFR -SHSN CENTRAL/ERN 2/3
FRI...BCMG VFR. NO SIG WX.
SAT...MVFR WITH SNOW SHOWERS ASSOC WITH AN APPROACHING COLD FRONT.
&&
.CLIMATE...
MOST OF THE FORECAST AREA WAS ZERO OR COLDER LAST NIGHT WITH
CHANDLER`S VALLEY BEING THE COLDEST COMING IN AT -32.
HARRISBURG AND WILLIAMSPORT BOTH TIED THEIR RECORD LOWS FOR THE
DATE. HARRISBURG WAS 0 AND WILLIAMSPORT WAS -5.
RECORD LOWS/YEAR
HARRISBURG.............0/1905
WILLIAMSPORT..........-5/1905
STATE COLLEGE.........-8/1904
YORK..................-7/1963
ALTOONA...............-2/2004
BRADFORD..............-23/1943
CLEARFIELD............-6/1930
JOHNSTOWN.............-10/1943
LANCASTER.............+2/1987
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR PAZ024>028-
033>036-056-057-059-063>066.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD/LA CORTE
SHORT TERM...LA CORTE
LONG TERM...GARTNER
AVIATION...LA CORTE/MARTIN
CLIMATE...LA CORTE
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 BROWNSVILLE TX
545 PM CST MON FEB 16 2015
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...THE COLD FRONT HAS PASSED THROUGH ALL TERMINALS AND
IS TRACKING SOUTH OF THE RIO GRANDE RIVER. IFR TO LOWER END MVFR
CEILING HAVE QUICKLY FILLED IN WAKE OF THE FRONT WITH NORTH WINDS
GUSTING 25 TO 30 KNOTS THROUGH AT LEAST 8 PM. THE HIGHER GUST TO
BECOME LESS FREQUENT WITH TIME WITH A STEADY NORTH WIND THE REST
OF THE NIGHT. CEILINGS TO RISE SLIGHTLY BUT REMAIN MAINLY ON THE
LOWER END OF MVFR UNTIL SUNRISE OR BY MID MORNING TUESDAY WHEN
THE MIGHT APPROACH VFR.
&&
.PREV DISCUSSION... /ISSUED 316 PM CST MON FEB 16 2015/
SHORT TERM /NOW THROUGH TUESDAY NIGHT/...A STRONG COLD FRONT
EXTENDING CURRENTLY FROM NEAR RIO GRANDE CITY TO NEAR BAFFIN BAY
WITH A PRE FRONTAL TROUGH AHEAD OF THE FRONT...ACROSS THE UPPER
PORTIONS OF THE RIO GRANDE VALLEY. WEST TO SOUTHWEST WINDS BETWEEN
2 TO 4K FEET MIXING DOWN TO THE SURFACE ALONG WITH FULL SUNSHINE HAS
ALLOWED TEMPERATURES TO SPIKE INTO THE LOW TO MID 80S ACROSS THE
VALLEY. BASED ON THE LATEST NAM/RAP AND HRRR DATA...THE STRONG FRONT
IS EXPECTED TO MOVE THROUGH MCALLEN AND HARLINGEN BETWEEN 4 AND 5
PM...BROWNSVILLE BETWEEN 5 AND 6 PM AND OFF THE LOWER TEXAS COAST
AROUND 7 PM. A DRASTIC CHANGE TO TEMPERATURES...BREEZY NORTH
WINDS...INCREASING LOW CLOUDINESS AND A POSSIBLE LIGHT SHOWER WILL
ACCOMPANY THE SHARP FROPA. TEMPERATURES WILL CONTINUE TO DROP
THROUGH THE EVENING WITH OVERNIGHT LOW TEMPERATURES IN THE 40S UNDER
MOSTLY CLOUDY SKIES. A MID TO UPPER LEVEL DISTURBANCE WILL MOVE
OVERHEAD TONIGHT. THIS FEATURE WILL SUPPORT ISOLATED TO SCATTERED
SHOWERS ACROSS THE REGION TONIGHT AND MAY LINGER ALONG THE COAST
INTO THE GULF WATERS TUESDAY MORNING.
SURFACE HIGH PRESSURE WILL BUILD ACROSS DEEP SOUTH TEXAS ON TUESDAY.
SKIES WILL GRADUALLY CLEAR BY TUESDAY AFTERNOON WITH TEMPERATURES
REMAINING WELL BELOW NORMAL. HIGH TEMPERATURES ON TUESDAY WILL BE IN
THE MID TO UPPER 50S WITH A FEW 60S POSSIBLE ACROSS THE WESTERN AREA
WITH MODERATE NORTH TO NORTHEAST WINDS. SURFACE HIGH PRESSURE
SETTLES ACROSS THE AREA TUESDAY NIGHT. CLEAR SKIES...DRY AIR AND
LIGHT WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING TUESDAY NIGHT.
OVERNIGHT LOW TEMPERATURES TUESDAY NIGHT EXPECTED TO FALL INTO THE
UPPER 30S ACROSS THE NORTHERN RANCHLANDS...LOWER 40S ACROSS THE RIO
GRANDE VALLEY AND THE MID 40S ALONG THE BEACHES.
LONG TERM /WEDNESDAY THROUGH MONDAY/...500 MB RIDGING WILL
BUILD OVER DEEP SOUTH TX STARTING WEDNESDAY CONTINUING INTO FRIDAY
WHICH WILL ALLOW THE 1000-500 MB THICKNESSES TO INCREASE WITH A
PERSISTENT S-SE SURFACE FLOW BRINGING IN STEADY WAA AT THE LOW
LEVELS. THIS WILL ALLOW TEMPS TO STEADILY INCREASE THROUGH THE END
OF THIS WEEK. AS THE WEEKEND APPROACHES THE 500 MB RIDGE WILL BE
ERODED STEADILY AS A SERIES OF STRONG SHORT WAVES CARVE OUT A
BROAD 500 MB TROUGH OVER THE NORTHERN HALF OF THE LOWER 48 STATES.
AS THIS 500 MB TROFFING DEEPENS A COLD FRONT WILL BE PUSHED
TOWARDS DEEP SOUTH TX ON SUN.
THE ECMWF AND GFS ARE IN GOOD AGREEMENT IN THE OVERALL PLACEMENT
OF THE 500 MB FEATURES THROUGH FRI. THE MODELS THEN START TO
DIVERGE STEADILY FROM SAT THROUGH MON WITH THE ECMWF DIGGING A
DEEPER 500 MB TROUGH AXIS OVER THE LOWER 48 STATES VERSUS THE GFS.
THE GFS KEEPS THE 500 MB TROUGH AXIS MORE ELONGATED FROM THE WEST
COAST UP THROUGH THE GREAT LAKES WHICH KEEPS THE COLD FRONT FROM
PUSHING THROUGH THE RGV.
MOISTURE ADVECTION AHEAD OF THIS NEXT POTENTIAL FROPA IS NOT THE
GREATEST IN THE WORLD SO WILL HOLD THE POPS AROUND 20 % LATE IN
THE FORECAST PERIOD UNTIL THE MODELS RESOLVE THEMSELVES A BIT
BETTER.
WILL LEAN MORE TOWARDS THE ECMWF SOLUTION THROUGH DAY 7 FOR TEMPS.
OVERALL CONFIDENCE IN THE FORECAST IS PRETTY GOOD THROUGH FRI THEN
STARTS TO DROP FOR THE SAT THROUGH MON PERIOD DUE TO THE ECMWF AND
GFS DIVERGENCE LATE IN THE PERIOD.
MARINE...NOW THROUGH TUESDAY NIGHT...LIGHT SOUTH TO SOUTHWEST WINDS
WILL CONTINUE ALONG THE LOWER TEXAS COASTAL FOR THE NEXT FEW HOURS.
A STRONG COLD FRONT WILL MOVE FROM NORTH TO SOUTH ACROSS THE MARINE
AREA. WINDS WILL QUICKLY SHIFT TO THE NORTH TO NORTHWEST WITH GUSTY
WINDS. A SMALL CRAFT ADVISORY IS IN EFFECT FOR ALL OF THE LOWER
TEXAS COASTAL WINDS DUE TO VERY STRONG WINDS WITH ROUGH SEAS ON THE
GULF. MARINE CONDITIONS GRADUALLY IMPROVE TUESDAY EVENING INTO
WEDNESDAY AS HIGH PRESSURE SETTLES ACROSS THE AREA.
WEDNESDAY THROUGH SATURDAY...A MODERATE TO STRONG S-SE WINDS WILL
PREVAIL IN THE LONGER RANGE MARINE FORECAST PERIOD AS BROAD
SURFACE RIDGING REMAINS IN PLACE OVER THE GULF OF MEX. THE PGF
TIGHTENS UP ENOUGH FROM LATE THURS THROUGH SATURDAY TO POSSIBLY
RESULT IN SOME SCA FOR THE GULF WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 48 56 45 66 / 30 20 0 0
BROWNSVILLE 47 57 44 67 / 30 20 0 0
HARLINGEN 46 57 42 67 / 30 20 0 0
MCALLEN 47 60 42 68 / 20 10 0 0
RIO GRANDE CITY 47 60 41 69 / 20 10 0 0
SOUTH PADRE ISLAND 51 56 52 64 / 40 30 0 0
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 3 AM CST TUESDAY FOR GMZ130-
132-135.
SMALL CRAFT ADVISORY UNTIL 6 PM CST TUESDAY FOR GMZ150-155-170-
175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
59...SHORT TERM/AVIATION
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
910 PM MST MON FEB 16 2015
.SYNOPSIS...A FEW SHOWERS MAY OCCUR EAST OF TUCSON TONIGHT. COULD
SEE SOME PATCHY FOG DEVELOP IN THE VALLEYS MAINLY SOUTH TO SOUTHEAST
OF TUCSON TONIGHT INTO TUESDAY MORNING. DRY CONDITIONS WITH WELL
ABOVE NORMAL DAYTIME TEMPERATURES WILL THEN PREVAIL TUESDAY AND
CONTINUE INTO THIS WEEKEND.
&&
.DISCUSSION...WATER VAPOR IMAGERY...17/00Z UPPER-AIR PLOTS AND MOST
RECENT MODEL GUIDANCE SHOW SHORTWAVE TROUGH CURRENTLY IN THE GENERAL
VICINITY OF THE FOUR CORNERS REGION IS PROGGED TO SWING INTO
NORTHERN NEW MEXICO AND THE TEXAS PANHANDLE BY EARLY TUESDAY
MORNING. THE LATEST IR SATELLITE IMAGERY SHOWS CLOUDINESS ASSOCIATED
WITH THIS SYSTEM COVERING MUCH OF EASTERN NEW MEXICO AND
SOUTHEASTERN COLORADO...WITH A THIN BAND OF LOW TO MID LEVEL CLOUDS
EXTENDING WESTWARD ACROSS WEST CENTRAL NEW MEXICO INTO EAST CENTRAL
ARIZONA...SPECIFICALLY THE WHITE MOUNTAINS OF APACHE COUNTY. THIS
BAND OF CLOUDS IS MOVING SOUTH SOUTHEAST. SOME ADDITIONAL HIGH
CLOUDS DROPPING SOUTH ON THE EASTERN FLANK OF THE RIDGE ACROSS PARTS
OF NEVADA....UTAH AND WESTERN ARIZONA. AT ANY RATE...THE LATEST RUN
OF THE HRRR INDICATES THAT THE AFOREMENTIONED BAND OF CLOUDS OVER
THE WHITE MOUNTAINS SHOULD CONTINUE TO SHIFT INTO WESTERN NEW MEXICO
OVERNIGHT.
NAM MOS GUIDANCE FROM EARLIER TODAY (12Z RUN) INDICATED A 47 PERCENT
CHANCE OF PRECIPITATION AT SAFFORD...WHILE THE GFS INDICATED ZERO
AND THE ECMWF SHOWED 6-HR POPS IN THE TEENS. THAT SAID...THE 00Z RUN
OF THE NAM NOW SHOWS ONLY A 10 PERCENT CHANCE OF SHOWERS FOR SAFFORD
BEFORE 12Z. WILL MAKE SOME TWEAKS TO THE POP FORECAST FOR THE
REMAINDER OF THE OVERNIGHT PERIOD TO REFLECT SLIGHT CHANCES NEAR THE
APPROACHING CLOUD BAND...BUT WILL TRIM BACK POPS OVER PARTS OF
COCHISE COUNTY IN ORDER TO MESH WITH EL PASO...BUT REFLECT A
DECREASING THREAT FOR SHOWERS.
AS OF 03Z (8 PM MST)...TEMPERATURES ACROSS THE REGION RANGED FROM
THE MID 50S TO THE MID 60S...WITH THE TUCSON INTL AIRPORT REPORTING
A TEMP OF 64 DEGS. THIS AFTERNOON THE HIGH AT TIA WAS 73 DEGS...
WHICH WAS 4 DEGS ABOVE NORMAL FOR THIS DATE. THE INHERITED OVERNIGHT
LOW TEMPS SEEM TO BE OK...BUT WILL MAKE SOME ADJUSTMENTS TO THE
SHORT TERM HOURLY TEMP GRIDS IN ORDER TO REFLECT ONGOING TRENDS.
FOR DETAILS REGARDING THE FORECAST BEYOND TONIGHT...PLEASE REFER TO
THE PREVIOUS DISCUSSION BELOW.
&&
.AVIATION...VALID THRU 18/06Z.
HIGH CLOUDS WILL CONTINUE TO STREAM INTO THE AREA AS THE SHORTWAVE
TROUGH OVER THE FOUR CORNERS EDGES THROUGH. THERE REMAINS SOME
LINGERING CU NEAR THE BORDER THOUGH THIS WILL DISSIPATE OVER THE
NEXT COUPLE OF HOURS. GENERALLY LIGHT WINDS EXPECTED THROUGH THE
PERIOD...WITH THE EXCEPTION OF THE SLIGHTLY ELEVATED...THOUGH
DIMINISHING...WINDS AT KSAD/KDUG THIS EVENING. THESE LIGHT WINDS
COULD SETUP SOME FOG DEVELOPMENT THIS MORNING THOUGH GIVEN THE HIGH
CLOUDS SPREADING IN WILL LIKELY REMOVE MENTION FROM TAFS WITH THE
06Z ISSUANCE. HIGH RES GUIDANCE SUPPORTS REMOVING THE MENTION AS
WELL. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...DRY CONDITIONS WITH WELL ABOVE NORMAL DAYTIME
TEMPERATURES AND GENERALLY LIGHT TERRAIN DRIVEN WINDS WILL BE THE
RULE INTO THIS WEEKEND.
&&
.PREV DISCUSSION...THE UPPER PATTERN THRU FRI WILL BE CHARACTERIZED
WITH A RIDGE NEAR THE WEST COAST AND A TROUGH OVER THE ERN CONUS.
AFTER ANY LOW CLOUDS/FOG DISSIPATE TUE MORNING...CLEAR SKIES OR
MOSTLY CLEAR SKIES WILL OCCUR THRU THURSDAY. INCREASING MID AND HIGH
CLOUDS WILL THEN PRODUCE PARTLY CLOUDY SKIES THUR NIGHT AND FRI.
A PATTERN CHANGE WILL OCCUR STARTING FRI NIGHT AND CONTINUE INTO
EARLY NEXT WEEK. THE UPPER RIDGE IS PROGGED TO RETROGRADE WEST OF
130W...AND AN UPPER LEVEL TROUGH WILL THEN DEVELOP OVER THE GREAT
BASIN/INTERMOUNTAIN WEST. THE 16/12Z GFS WAS DEEPER WITH THIS TROUGH
VERSUS THE 16/12Z ECMWF...ESPECIALLY THIS WEEKEND. IN FACT...THE GFS
SUGGESTS THAT SOME SHOWERS WILL OCCUR ACROSS ERN SECTIONS SAT.
THEREAFTER...THE GFS/ECMWF WERE IN BETTER AGREEMENT WITH THE UPPER
PATTERN EARLY NEXT WEEK. THESE SOLUTIONS DEPICTED A DRY...ZONAL FLOW
REGIME ACROSS THE AREA. GIVEN THE CONTINUED RUN-TO-RUN DIFFERENCES
BETWEEN GFS/ECMWF SOLUTIONS AND PER COORD WITH NEIGHBORING
WFO/S...HAVE MAINTAINED DRY CONDITIONS SAT-MON.
HIGH TEMPS TUE WILL BE SIMILAR TO TEMPS ACHIEVED THIS AFTERNOON...
THEN ABOUT 5 DEGS F OR SO OF DAILY WARMING IS FORECAST TO OCCUR
WED-THUR. THE WARMEST DAY FOR MOST LOCALES WILL BE THUR...THEN A
GRADUAL COOLING TREND IS ON TAP SAT-MON.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
CURRENT DISCUSSION...MOLLERE
AVIATION/FIRE WEATHER...MEADOWS
PREVIOUS DISCUSSION...FRANCIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
359 AM EST TUE FEB 17 2015
.SYNOPSIS...
A STORM MOVING OFF THE MID ATLANTIC COAST MAY BRING SOME
LIGHT SNOW TO FAR SOUTHERN AREAS...OTHERWISE IT WILL BE MOSTLY
CLOUDY AND CONTINUED COLD TODAY. AN ARCTIC COLD FRONT WILL BRING
SOME SNOW SHOWERS TO THE REGION TOMORROW INTO TOMORROW NIGHT WITH
MORE BITTER COLD AIR TO FOLLOW FOR THURSDAY AND FRIDAY. TEMPERATURES
WILL REMAIN BELOW NORMAL THROUGH THE UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 359 AM EST...IR SATELLITE IMAGERY SHOWS OUR REGION IS ON
THE NORTHERN EDGE OF A SHIELD OF CLOUDS FROM A STORM SYSTEM OVER
THE MID ATLANTIC STATES. THE FAR NORTHERN AND WESTERN AREAS OF THE
CWA ARE IN NEARLY CLEAR SKIES...WHICH IS ALLOWING FOR TEMPS TO
CONTINUE TO FREE FALL. PARTS OF THE ADIRONDACKS...INCLUDING THE
LAKE GEORGE AND GLENS FALLS AREAS...ARE -10 TO -30 DEGREES. WINDS
ARE NEARLY CALM...SO DESPITE THE FRIGID AIRMASS...THERE IS NO
ADDITIONAL WIND CHILL FACTOR IN PLACE. MEANWHILE...IN AREAS WHERE
CLOUD COVER IS PRESENT...TEMPS ARE MUCH WARMER...MAINLY ZERO TO 12
DEGREES. TEMPS IN THESE ARE ALREADY NEAR THEIR MINS...AND ARE
LIKELY TO HOLD STEADY OR ONLY SLOWLY FALL TOWARDS DAYBREAK.
WITH THE STORM SYSTEM MOVING OFF THE MID ATLANTIC COAST...SOME
LIGHT SNOW IS BEING REPORTED ACROSS THE POCONOS...NORTH
JERSEY...AND IN THE NYC METRO AREA. KENX RADAR SHOWS SOME LIGHT
RETURNS FURTHER NORTH THAN THAT...SUCH AS OVER THE CATSKILLS AND
MID HUDSON VALLEY...BUT THE VERY DRY AIRMASS IN PLACE AT LOW
LEVELS IS ALLOWING THIS PRECIP TO DRY UP BEFORE IT REACHES THE
SFC. THE 07Z 3KM HRRR SHOWS SOME LIGHT SNOWFALL MAY TRY TO FALL
ACROSS ULSTER...DUTCHESS...AND LITCHFIELD COUNTIES THROUGH ABOUT 9
AM. IF THE ATMOSPHERE IS ABLE TO MOISTEN UP ENOUGH...A DUSTING TO
AN INCH OF SNOW COULD BE POSSIBLE ACROSS THOSE AREAS. FURTHER
NORTH...NO SNOWFALL IS EXPECTED TO OCCUR. AFTER ABOUT MID
MORNING...POPS TAPER OFF ACROSS OUR AREA.
THE STORM SYSTEM WILL MOVE OUT TO SEA LATER TODAY. CLOUDY SKIES
WILL GRADUALLY GIVE WAY TO A FEW BREAKS FOR VALLEY AREAS BY LATE
IN THE DAY...OTHERWISE SKIES WILL REMAIN MOSTLY CLOUDY OVER THE
AREA. MAX TEMPS TODAY WILL GENERALLY BE IN THE TEENS...WITH SOME
READINGS NEAR 20 IN FAR SOUTHERN AREAS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
DRY WEATHER IS EXPECTED TO BE IN PLACE TONIGHT...WITH WEAK HIGH
PRESSURE IN PLACE OVER THE AREA. THERE MAY BE SOME BREAKS IN THE
CLOUDS...AND WITH LIGHT WINDS AND SNOWPACK IN PLACE...ANOTHER VERY
COLD NIGHT IS EXPECTED. TEMPS WILL RANGE BETWEEN 10 BELOW AND 10
ABOVE...WITH THE COLDEST READINGS OVER THE ADIRONDACKS...SRN
VT...AND BERKSHIRES.
AN ARCTIC COLD FRONT WILL BE APPROACHING THE REGION FROM THE GREAT
LAKES FOR WEDNESDAY. IN ADDITION TO A STRONG SHORTWAVE...THIS
FRONT WILL BE AIDED BY A TIGHT THERMAL GRADIENT ALOFT. BOTH THE
NAM12 AND THE 4KM WFO BTV WRF SUGGEST THAT A LINE OF CONVECTIVE
SNOW SQUALLS COULD ACCOMPANY THIS FRONTAL BOUNDARY AS IT CROSSES
OUR AREA WED AFTN INTO WED EVENING. WHILE SNOW AMOUNTS ARE LIKELY
BE LIGHT /MAINLY AN INCH OR LESS/...ANY SNOW SQUALL COULD BE
ACCOMPANIED BY A BRIEF REDUCTION IN VISIBILITY AND STRONG WINDS.
TEMPS WILL BE MILDER AHEAD OF THIS FRONT...WITH LOW TO MID 20S FOR
MANY AREAS.
BEHIND THE ARCTIC FRONT...MUCH COLDER AIR WILL MOVE INTO THE
REGION ONCE AGAIN FOR WED NIGHT INTO THURSDAY. TEMPS WILL FALL
TO 10 BELOW TO 10 ABOVE FOR WED NIGHT...AND WON/T RISE MUCH FOR
DURING THE DAY THURSDAY...WITH HIGHS ONLY ZERO TO 15 ABOVE OVER
THE AREA. IN ADDITION...THERE WILL BE A GUSTY W-NW BREEZE...ESP
FOR THE HIGH TERRAIN AREAS. SOME ADDITIONAL SNOW SHOWERS WILL BE
POSSIBLE WED NIGHT INTO THURSDAY AS THE UPPER LEVEL DISTURBANCE
MOVES ACROSS THE REGION...AND ANOTHER SFC LOW STARTS TO DEVELOP
OFF THE NEW ENGLAND COAST. AN ADDITIONAL COATING TO AN INCH WILL
BE POSSIBLE ACROSS THE REGION. ALSO...THERE MAY BE SOME LAKE
EFFECT ACTIVITY OFF LAKE ONTARIO AS WELL...AND THIS BAND COULD
EXTEND INTO PARTS OF THE WESTERN MOHAWK VALLEY AS WELL...DEPENDING
ON IT/S EXACT ORIENTATION AND INLAND EXTENT OFF THE LAKE. WE WILL
BE MONITORING THIS POTENTIAL CLOSELY OVER THE NEXT FEW DAYS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
..BELOW TO MUCH BELOW NORMAL TEMPS CONTINUE THROUGH THE LONG TERM
PORTION OF THE FORECAST..
SO FAR FOR THE MONTH OF FEBRUARY WE ARE IN SECOND PLACE WITH RESPECT
TO THE AVERAGE COLDEST AND WELL WITHIN THE TOP 10 OF THE SNOWIEST
SINCE OUR RECORDS BEGAN BACK INTO THE 1800S. AS MORE COLD AIR AND
SNOW ARE IN THE FORECAST...WILL BE INTERESTING TO WATCH TRENDS WHEN
WE CLOSE OUT THE MONTH ON THE 28TH.
AS THE PREVIOUS EXCELLENT DISCUSSION DETAILED...DEPARTING UPPER
LOW/VORTEX WILL ALLOW FOR CLOUDS AND THE CHANCE FOR ADDITIONAL LIGHT
SNOW/SNOW SHOWERS THURSDAY NIGHT /MAINLY INTO THE TERRAIN/. AS
AROUND 500DM HEIGHTS AND H850 TEMPS WELL INTO THE SUB 20S CELSIUS
COMBINING WITH A RATHER TIGHT PRESSURE GRADIENT...ADDITIONAL WIND
CHILL HEADLINES APPEAR LIKELY AT THIS TIME. WE WILL CONTINUE TO
HIGHLIGHT THIS HAZARD IN THE HWO.
CONSENSUS CONTINUES TO FAVOR RIDGING TO EVOLVE ACROSS THE ENTIRE
REGION FRIDAY INTO FRIDAY EVENING. WHILE WE WILL BE NULL OF
PRECIPITATION...IT WILL REMAIN COLD WITH TEMPERATURES MAINLY INTO
THE SINGLE DIGITS. WINDS WILL BE DIMINISHING AS WE SHOULD
EXPERIENCE A BREAK FROM THE WIND CHILL HEADLINES.
HOWEVER...HUDSON BAY VORTEX BECOMES REESTABLISHED THIS WEEKEND. A
FEW PV ANOMALIES ARE SET TO DIVE SOUTHEAST FROM THE NORTHWEST
TERRITORIES AND MOVE ACROSS THE REGION THROUGH THE WEEKEND. THE
ECMWF HAS RELAXED ITS HIGHLY AMPLIFIED SURFACE WAVE DEVELOPMENT AND
IS MORE IN LINE WITH THE GFS AS A PROGRESSIVE WAVE. THIS WILL ONLY
ADD TO THE SNOW BASE WITH AVERAGE GFS/ECMWF QPF VALUES BETWEEN ONE
QUARTER AND ONE HALF INCH. WHERE THESE MODELS DIFFER IS THE EXIT
STRATEGY WHERE THE ECMWF IS MUCH QUICKER THAN THE GFS. FOR NOW...WE
WILL INCREASE POPS FOR THIS WEEKEND WITH MORE ACCUMULATING LIGHT
SNOW.
SUNDAY NIGHT INTO MONDAY...ANOTHER POTENTIALLY BITTERLY COLD NIGHT
WITH THE COMBINATION OF LIKELY MORE FRESH SNOW...DIMINISHING WINDS
AS THE SURFACE HIGH BUILDS INTO THE REGION AND CLEARING SKIES.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
THICKENING AND LOWERING CLOUDS TO BE EXPECTED THE REMAINDER OF
THE OVERNIGHT PERIOD AS CIGS SHOULD REMAIN IN VFR TERRITORY.
RESTRICTIONS ARRIVE MAINLY AT KPOU TOWARD MORNING WITH SOME LIGHT
SNOW AND LOWERING CIGS. KPSF REMAINS ON THE NORTHERN PERIPHERY OF
THIS SYSTEM AS WE WILL CONTINUE WITH VCSH AT THIS TIME. AS THE
STORM PASSES OFF THE MID ATLANTIC COAST...LOWER LEVEL MOISTURE
BORDERING VFR/MVFR WILL REMAIN IN THE FORECAST FOR THE BALANCE OF
THE DAY.
WINDS AT KPSF WILL REMAIN FROM THE WEST WITH DIMINISHING SPEEDS AS
WINDS ELSEWHERE WILL BE OR BECOME LIGHT AND VARIABLE OVERNIGHT
THROUGH TUESDAY.
OUTLOOK...
TUE NIGHT-WED AM: NO OPERATIONAL IMPACT. NO SIG WX.
WED PM-WED NIGHT: LOW OPERATIONAL IMPACT. CHC -SHSN.
THU-FRI: NO OPERATIONAL IMPACT. NO SIG WX.
SAT: MODERATE OPERATIONAL IMPACT. CHC SN.
&&
.HYDROLOGY...
ICE WILL CONTINUE TO THICKEN ON AREA RIVERS...STREAMS...LAKES...AND
PONDS...AS CONTINUED BELOW NORMAL TEMPERATURES REMAIN IN PLACE
THROUGH THE ENTIRE UPCOMING WEEK. TEMPERATURES ARE NOT EXPECTED TO
RISE ABOVE FREEZING DURING THE NEXT FIVE DAYS.
ANY PRECIP...ALL IN THE FORM OF SNOW...WILL BE FAIRLY LIGHT OVER
THE NEXT FEW DAYS. SOME LIGHT SNOW MAY IMPACT FAR SOUTHERN AREAS
THROUGH MID MORNING TODAY...BUT AMOUNTS WILL BE SMALL AND WILL
HAVE NO IMMEDIATE HYDROLOGIC IMPACT. SOME SNOW SHOWERS MAY IMPACT
THE ENTIRE REGION AS WELL FOR WEDNESDAY AFTERNOON THROUGH THURSDAY
AS WELL.
SOME GAGES WILL EXPERIENCE ICE EFFECTS...AND SOME ERRONEOUS DATA
MAY BE SEEN FROM TIME TO TIME.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...FRUGIS
LONG TERM...BGM
AVIATION...BGM
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
405 AM EST TUE FEB 17 2015
.SYNOPSIS...
LOW PRESSURE WILL MOVE OFF THE COAST TODAY. PRECIPITATION WILL END
EARLY THIS MORNING. WELL BELOW NORMAL TEMPERATURES EXPECTED
THROUGH THE WEEK UNDER THE INFLUENCE OF AN ARCTIC AIR MASS.
&&
.NEAR TERM /THROUGH TODAY/...
LATEST HRRR AND RAP GUIDANCE INDICATES PRECIPITATION LIKELY PUSH
EAST OF THE REGION EARLY THIS MORNING AS ISENTROPIC DOWN-GLIDE
DEVELOPS. PLAN IS TO LET WARNINGS AND ADVISORIES EXPIRE AT 700 AM. MODELS
INDICATE COLD ADVECTION DURING THE DAY AND CONSIDERABLE CLOUDINESS
UPSTREAM SO EXPECT TEMPERATURES TO STRUGGLE TO RISE THROUGH THE
40S.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/...
EASTERN CONUS UPPER LEVEL TROUGH AMPLIFIES TONIGHT AND WEDNESDAY
WITH RESULTING STRENGTHENING COLD ADVECTION. LIGHT WINDS TONIGHT
SO TEMPERATURES WILL FALL BELOW FREEZING. INCREASING WEST LOW
LEVEL WINDS EXPECTED DURING THE DAY WEDNESDAY...LAKE WIND ADVISORY
WILL LIKELY BE NEEDED WITH SUSTAINED WINDS AROUND 20 KTS AND
FREQUENT GUSTS ABOVE 30 KTS POSSIBLE. STRONG SHORT WAVES ROTATING
THROUGH REGION DURING THE DAY...DEEP MOISTURE LIMITED BUT CANT
RULE OUT SOME LIGHT SNOW SHOWERS IN THE AFTERNOON MAINLY NORTH
MIDLANDS. MODEL SOUNDINGS NORTH MIDLANDS SUPPORTS A LOW POPS IN
THAT REGION. CONSIDERABLE CLOUDS LIKELY THROUGH THE DAY THEN
CLEARING BEHIND THE SHORT WAVE IN THE EVENING. WINDS LIKELY TO
STAY UP THROUGH AT LEAST MIDNIGHT WITH STRONG MIXING/CONTINUED
COLD ADVECTION. MAX TEMPERATURE FORECAST BELOW GUIDANCE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
GENERALLY DRY INTO THE WEEKEND. HIGH PRESSURE WILL BUILD IN FROM THE
WEST WITH A REINFORCING SHOT OF ARCTIC AIR MOVING INTO THE AREA
THURSDAY AND FRIDAY. ANOTHER LOW PRESSURE SYSTEM DEVELOPING IN
THE SOUTHERN PLAINS BY EARLY SATURDAY WILL MOVE INTO THE TN VALLEY
BY SUNDAY AS MORE HIGH PRESSURE BUILDS IN FROM THE NORTH. AS A
RESULT...A COLD AIR DAMMING SCENARIO MAY OVER THE WEEKEND INTO
MONDAY. STILL LOTS OF QUESTIONS REGARDING TIMING AND PLACEMENT OF
THIS NEXT SYSTEM AND THE POSSIBILITY OF ANY WINTRY PRECIPITATION
EARLY NEXT WEEK. BUT WITH SOME MANY MODEL UNCERTAINTIES AT THIS
TIME...FOR NOW WILL KEEP PRECIPITATION ALL LIQUID SATURDAY INTO
MONDAY WITH CHANCE POPS. TEMPERATURES GENERALLY BELOW NORMAL THROUGH
THE EXTENDED PERIOD...WITH WELL BELOW NORMAL TEMPERATURES THURSDAY
AND FRIDAY. IN FACT...CURRENT MEX/MEN GUIDANCE HAS TEMPERATURES
ABOUT 20 TO 25 DEGREES BELOW NORMAL FOR CAE AND AGS THURSDAY AND
FRIDAY.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
IFR CIGS MVFR VSBYS ACROSS ALL BUT THE SE PORTIONS OF THE FORECAST
AREA WHICH REMAINS VFR. STRONG LOW LEVEL JET AHEAD OF THE LOW
WARRANTS INCLUSION OF LLWS. LOW PRESSURE OVER CENTRAL GA WILL
TRACK EAST ACROSS CENTRAL GA AND EASTERN SC TONIGHT...MAINLY ALONG
THE WARM FRONT THAT EXTENDS FROM JUST SOUTH OF AUGUSTA TO MYRTLE
BEACH. FREEZING RAIN MAINLY NORTH OF A SALUDA TO BISHOPVILLE LINE
AND RAIN SOUTH OF THE LINE. MODELS HAVE THE BACK EDGE OF THE
PRECIP FROM A CHARLOTTE TO AUGUSTA LINE AROUND 13Z SWEEPING
EASTWARD OUT OF THE AREA BY 17Z WITH SLOW IMPROVEMENT IN CIGS
EXPECTED DURING THE DAY.
EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS EXPECTED WEDNESDAY
AND THURSDAY. CIG RESTRICTIONS AND SHOWER CHANCES COULD RETURN
SAT/SUN.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...ICE STORM WARNING UNTIL 7 AM EST THIS MORNING FOR SCZ015-016-
020-021.
FREEZING RAIN ADVISORY UNTIL 7 AM EST THIS MORNING FOR SCZ022-
026>028.
GA...NONE.
&&
$$
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
331 AM CST Tue Feb 17 2015
.SHORT TERM...(Today)
ISSUED AT 330 AM CST TUE FEB 17 2015
A shortwave will trigger scattered flurries early this morning
across a large portion of central and southeast IL. The back edge
of the band of clouds/flurries is approaching NW IL at 3 am, and
should progress from NW to SE across the area this morning. Will
keep a mention of flurries along that band of clouds as it
progresses across the area.
Even in the clearing behind the shortwave, forecast soundings show
enough residual low level moisture for clouds to redevelop in any
periods of sunshine. Will work a period of clearing in the NW
counties later this morning, but increase clouds again later in the
afternoon.
The short range models continue to show a fast moving wave just west
of IL triggering a band of light snow later this afternoon. As the
wave curves around the south end of IL, snow showers will begin to
develop just south of our counties toward sunset. Have stuck with
just flurries for the snow forecast, and will not carry PoPs for
measurable snow near that feature.
Clear skies and light winds in the areas with new snow cover has
allowed temps early this morning to drop significantly below
guidance. Robinson has reached -10F, Lawrenceville -5, and Mount
Carmel -4 at 3 am. Unless the SE areas see some sunshine early this
afternoon, their highs will likely be affected by the bitterly cold
start to the day. Will trim a few degrees from forecast highs in the
southeast, and remain closer to a MAV/MET blend farther north.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 330 AM CST TUE FEB 17 2015
00Z models continue to dig a strong upper level trof into the
Midwest during midweek and usher in more arctic air into the region
with the coldest temps from Wed thru Thu. A wind chill advisory will
eventually be needed Wed night and Thu morning across central and
southeast IL for wind chills of 15-25 below zero.
A northern stream short wave that digs into the trof over IL/IN
tonight keeps most of its light snow just south of central IL CWA
though scattered flurries will likely occur tonight into Wed. 850 mb
temps drop to -25 to -27C by Wed evening and this to be another
frigid air mass with highs struggling to reach 10F both Wed and Thu.
Lows Tue night in the single digits, then drop into single digits
below zero Wed night and some areas near IN border could dip below
zero again Thu night. A secondary arctic cold front plows se through
central IL late tonight into Wed morning. Brisk nw winds behind this
cold front on Wed will already bring wind chills down to -15F or a
bit colder Wed morning over IL river valley especially nw of the
river and reaching near wind chill advisory criteria. Coldest wind
chills of 15-25 below zero will occur Wed night into Thu morning and
coldest readings over Knox and Stark counties.
Deep upper level trof shifts east of IL Thu night and Friday while
arctic high pressure also drifts east of IL across the Ohio river
valley Thu night and Fri morning. Temps will be slow to climb
however on Friday due to mostly cloudy skies with highs in the low to
mid 20s. Have small chances of light snow Friday afternoon sw
counties ahead of next short wave. Extended models still differ with
handling southern stream storm system this weekend. ECWMF model has
trended further south with it surface low from central IL down to
just south of IL Sat. While GFS has surface low near KY/TN border by
midnight Sat night. GEM model moves low across TN on Sat. Due to
difference in models and from previous runs, stayed close to
guidance pops which are trending upward in southeast IL Sat/Sat
night. Looks cold enough for mainly light snow, though do continue a
mix over southeast IL on Sat. Have just slight chance of light snow
Sunday and then dry across area by Sunday evening. Highs in the low
to mid 30s Sat cool off again early next week on Sunday and Monday
behind this storm system.
The Climate Prediction Center (CPC) day 8-14 outlook for Feb 24-Mar
2 has IL in greater than 60% chance of below normal temperatures and
greater than 40% chance of below normal precipitaton. So winter
looks to hold on the next two weeks.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1110 PM CST MON FEB 16 2015
Low VFR cigs spreading slowly east and southeast late this
evening and should encompass all TAF sites by 09z. Cold front
pushing across east central Iowa will bring about a wind shift
Tuesday morning into the west and northwest along with a period
of MVFR cigs immediately behind the frontal passage. Latest RAP
and HRRR forecasts suggest the MVFR cigs should push into PIA
around 09z and finally into CMI at 12z. Based on the past several
forecast runs, it appears about a 2-3 hour period of MVFR cigs
before improving to VFR by 15z at PIA and 18z over in CMI.
500 mb trof axis still located to our west on Tuesday so if we do
see any breaks in the cloud cover, the rather cold 500 mb temps
will lead to some scattered to broken stratocu clouds between
3000-4000 feet during the afternoon. At this point will include a
scattered group at 3500 feet. A few flurries will be possible with
or just behind the cold front tomorrow morning and possibly again
the afternoon but at this time it appears coverage will be quite
limited so have decided to hold off any mention of flurries in
this set of TAFs. Surface winds will be light southwest overnight
and switch into the west around dawn Tuesday and then into the
northwest as the front shifts off to our east. Wind speeds tonight
will be less than 10 kts and increase to between 10 and 15 kts
on Tuesday with a few gusts near 20 kts by late morning or early
afternoon, before diminishing around sunset.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Shimon
LONG TERM...07
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1133 PM CST MON FEB 16 2015
.SHORT TERM...
224 PM CST
THROUGH WEDNESDAY...
RELATIVELY QUIET DAY TODAY...WITH THE SNOW PASSING WELL SOUTH OF THE
FORECAST AREA AND LIGHT/VARIABLE WINDS THIS AFTN. THIS HAS KEPT THE
LAKE EFFECT SNOW CONFINED TO THE CENTRAL/NORTHERN PORTIONS OF THE
LAKE...WHICH REMAINS VISIBLE ON SATELLITE IMAGERY. SFC TEMPS HAVE
REMAINED IN THE TEENS ACROSS MUCH OF THE FORECAST AREA. THE EXTREME
SOUTHERN CWFA MAY BE ABLE TO SEE A FEW LOCATIONS TOUCH 20 DEGREES
LATE THIS AFTN.
WEAK GRADIENT WILL REMAIN OVER THE FORECAST AREA TONIGHT...THEN AS
DAYBREAK APPROACHES THE ARCTIC AIR ACROSS THE UPPER MIDWEST WILL
DIVE SOUTH. POTENT 850MB THERMAL TROUGH OF -18 TO -20 DEG C ARRIVES
ACROSS THE NORTHERN CWFA BY 15Z TUE...THEN CONTINUES TO PUSH
SOUTH/SOUTHEAST THROUGHOUT THE AFTN. TEMPS SHUD BE ABLE TO WARM INTO
THE MID/UPR TEENS BY MIDDAY...THEN REMAIN STATIONARY WITH THE COLD
AIR ADVECTING IN. THE FAR NORTHWEST CWFA MAY OBSERVE FALLING TEMPS
BY EARLY AFTN. GUIDANCE HAS CONTINUED TO HINT THAT SOME LGT SNOW MAY
DEVELOP IN THE AFTN HOURS. THE MOISTURE IS VERY
SHALLOW/MARGINAL...BUT WITH LAPSE RATES STEEPENING IT IS POSSIBLE WE
COULD SEE SOME LGT SNOW BUT OPTED TO MENTION FLURRIES AT THIS TIME.
THEN AFT SUNSET TUE EVE THE MOISTURE DEPTH DECREASES WITH LIFT
BECOMING MINIMAL. SO THERE COULD BE A LULL IN FLURRIES/LGT
SNOW...UNTIL A REINFORCING TROUGH OF COLD AIR ARRIVES TUE NGT/EARLY
WED. MOISTURE CONTINUES TO BE MINIMAL TUE NGT/EARLY WED...BUT THE
LIFT/OMEGA ALONG WITH LAPSE RATES LOOKS SLIGHTLY BETTER. SO HAVE
HELD ONTO A SLT CHC POPS OR LGT SNOW IN THIS TIMEFRAME. ANY
ACCUMULATIONS SHOULD BE LESS THAN ONE INCH. WINDS WILL BE ON THE
INCREASE TUE NGT/EARLY WED...WITH LOWS AROUND 0 AND WIND CHILLS
DIPPING INTO THE TEENS BELOW ZERO.
THE THERMAL TROUGH TUE NGT/WED WILL BE MUCH COLDER THAN THE PRIOR
NIGHT...WITH GUIDANCE PROGGING -22 TO -24 DEG C BY WED. THIS WILL
LIKELY KEEP TEMPS FROM WARMING MUCH BEYOND THE SINGLE DIGITS ABOVE
ZERO. CLOUD COVER WILL BE DECREASING WED NGT WITH HIGH PRESSURE
BUILDING IN FROM THE WEST. WINDS WILL REMAIN BREEZY FROM THE
NORTHWEST. WITH CLOUDS THINNING WED NGT...TEMPS WILL QUICKLY
RADIATING INTO THE SINGLE DIGITS BELOW ZERO. DANGEROUS WIND CHILLS
ARE FORECAST FOR EARLY THUR...APPROACHING -20 TO -30 DEG.
BEACHLER
&&
.LONG TERM...
224 PM CST
THURSDAY THROUGH MONDAY...
THE LONGWAVE PATTERN GOING THROUGH THE END OF THE WEEK INTO EARLY
NEXT WEEK LOOKS TO BE A REPEAT OF THE PAST. HIGH AMPLITUDE RIDGE
ACROSS ALASKA COUPLED WITH A DOWNSTREAM RIDGE OVER THE NORTH
ATLANTIC WILL LOCK IN PLACE THE BROAD TROUGHING ACROSS THE CENTRAL
CONUS/GREAT LAKES/NORTHEAST CONUS THROUGH AT LEAST THE NEXT WEEK.
THERE IS SOME RELAXING TO THE POTENCY OF THE THERMAL TROUGH OVER THE
WEEKEND...HOWEVER ENSEMBLES ARE IN GOOD AGREEMENT THAT THE RIDGE
OVER ALASKA MAY FURTHER STRENGTHEN HEADING INTO THE SECOND HALF OF
THE WEEKEND/EARLY NEXT WEEK.
PERIODIC CHANCES FOR FLURRIES/LGT SNOW WILL ARRIVE OVER THE
WEEKEND/EARLY NEXT WEEK. TEMPS THUR WILL REMAIN IN THE SINGLE DIGITS
ABOVE ZERO...TO THE TEENS FRI. THEN OVER THE WEEKEND WITH SOME
RELAXING TO THE ARCTIC AIRMASS...TEMPS SHUD RETURN TO THE MID/UPR
20S.
BEACHLER
&&
.CLIMATE...
WHILE THE COLDEST AIR ALOFT ARRIVES WEDNESDAY...THE COLDEST SURFACE
TEMPERATURES MAY RESULT ON THURSDAY FEBRUARY 19TH...WHICH RIGHT NOW
APPEARS COULD JEOPARDIZE SOME RECORDS...ESPECIALLY THE LOW MAXS.
FEB 19TH
RECORD LOW RECORD LOW MAX
CHICAGO -7 (1936) 9 (1936)
ROCKFORD -16 (1979) 7 (1959)
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* POTENTIAL FOR SOME SNOW SHOWERS AND FLURRIES TOWARDS
MORNING...MVFR CONDITIONS POSSIBLE.
* POTENTIAL FOR A SHORT PERIOD OF HEAVIER SNOW SHOWERS LATE
TUESDAY NIGHT WITH IFR POSSIBLE.
KJB
//DISCUSSION...UPDATED 06Z...
A COLD FRONT WILL MOVE ACROSS THE TERMINALS AROUND DAYBREAK THIS
MORNING. A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LIKELY PUSH
ACROSS THE AREA PRIOR TO ITS ARRIVAL...AND THIS COULD RESULT IN SOME
BRIEF PERIODS OF SOME MVFR VIS AND CIGS. OTHERWISE MOST OF THE DAY
TODAY WILL BE DOMINATED BY A WEST-NORTHWEST WIND AROUND 290 DEGREES
WITH SOME SOME LOW END GUSTS UP AROUND 18 KT POSSIBLE.
LATER IN THE TAF PERIOD...LATER TUESDAY NIGHT...A STRONG ATMOSPHERIC
DISTURBANCE IS EXPECTED TO MOVE OVER THE AREA. AS THIS DOES SO...A
PERIOD OF HEAVIER SNOW SHOWERS COULD OCCUR...AND THIS COULD RESULT
IN REDUCED VISIBILITIES AND SOME MINOR SNOW ACCUMULATIONS. AT THIS
TIME IT APPEARS THE BEST POTENTIAL WOULD COME AFTER 06 UTC WEDNESDAY
MORNING. IT ALSO APPEARS TO BE A SHORT LIVED EVENT. I HAVE ADDED A
PROB 30 TO THE CURRENT 30 HOUR ORD TAF TO ADVERTISE THIS POTENTIAL.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM ON TIMING OF SNOW SHOWERS THIS MORNING.
* LOW TO MEDIUM ON EXTENT OF SNOW SHOWERS LATER TUESDAY NIGHT.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...CHANCE OF FLURRIES ESPECIALLY EARLY. MVFR CIGS
POSSIBLE. BREEZY NORTHWEST WINDS.
THURSDAY...MAINLY VFR. NORTHWEST WINDS.
FRIDAY...CHANCE OF SNOW MAINLY FRIDAY NIGHT. MVFR/IFR POSSIBLE
LATE. SOUTH WINDS.
SATURDAY...CHANCE OF SNOW. MVFR POSSIBLE. SOUTHWEST WINDS
BECOMING NORTHWEST.
SUNDAY...SLIGHT CHANCE OF SNOW SHOWERS. MVFR POSSIBLE. NORTH-
NORTHEAST WINDS.
RATZER
&&
.MARINE...
216 PM...HIGH PRESSURE OVER THE EASTERN LAKES WILL MOVE NORTHEAST
TONIGHT AS IT WEAKENS. A COLD FRONT/TROUGH OF LOW PRESSURE OVER
THE UPPER MIDWEST WILL MOVE SOUTHEAST ACROSS THE LAKE OVERNIGHT.
WEAK LOW PRESSURE WILL DEVELOP ALONG THIS TROUGH OVER EASTERN LAKE
SUPERIOR TUESDAY MORNING. AS THIS LOW MOVES TO LAKE HURON TUESDAY
NIGHT...THE GRADIENT WILL REMAIN WEAK OVER NORTHERN LAKE MICHIGAN.
THE GRADIENT WILL SLOWLY TIGHTEN OVER SOUTHERN LAKE MICHIGAN INTO
WEDNESDAY MORNING AS HIGH PRESSURE BUILDS ACROSS THE PLAINS. THIS
HIGH WILL MOVE SOUTHEAST TO THE OHIO VALLEY BY THURSDAY EVENING...
AS THE GRADIENT SLOWLY WEAKENS OVER THE WESTERN LAKES. THERE COULD
BE A PERIOD OF LOW END GALES OVER THE SOUTHERN HALF OR SO OF LAKE
MICHIGAN ON WEDNESDAY...BUT CONFIDENCE IS LOW. AS THE HIGH SHIFTS
EAST OF THE LAKE...WINDS WILL TURN SOUTHERLY FRIDAY AND FRIDAY
NIGHT. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1115 PM CST Mon Feb 16 2015
.UPDATE...
ISSUED AT 825 PM CST MON FEB 16 2015
The storm system that produced the heavy snow over southeast
Illinois last night through this morning has shifted well east
of our area early this evening with weak high pressure moving
across central Illinois. The latest surface map showing another
cold front poised to our northwest and forecast to track across
our area tomorrow morning. Other than some lower clouds and
scattered flurries, not much in the way of weather associated
with it. As far as tonight is concerned, clouds were on the
increase again over northwest Illinois, but were still mostly
clear over east central and far southeast Illinois. The
combination of the mostly clear sky and relatively light winds
in southeast Illinois, coupled with a fresh snow cover, has
led to some rapid temperature falls. Have made some adjustments
to the early evening as well as overnight temperatures in this
area to account for the faster temperature decline this evening.
Should have an updated forecast out by 845 pm.
&&
.SHORT TERM...(Tonight)
ISSUED AT 306 PM CST MON FEB 16 2015
20z/2pm analysis shows light snow continuing to fall across the E/SE
KILX CWA, mainly along/southeast of an Effingham to Paris line.
Based on radar timing tools, most of the precip will shift into
Indiana by 00z: however, will hang on to slight chance PoPs across
the far SE around Robinson and Lawrenceville through early evening
in case departure slows. Further north and west, the cloud cover
has thinned out this afternoon, allowing a few peeks of sunshine to
occur. Partly to mostly cloudy conditions will prevail through the
evening hours before a cold front currently across Minnesota/the
Dakotas approaches from the northwest overnight. Clouds will be on
the increase ahead of the boundary and a few snow flurries may occur
along/west of I-55 as the profile moistens and lift increases.
Overnight low temperatures will be coldest across the southeast
where a deep snow cover is in place. Have therefore undercut MAV
guidance numbers by a couple of degrees there, resulting in lows in
the single digits along/south of a Taylorville to Paris line.
Elsewhere have gone a little above guidance in the teens due to
increasing clouds and a light SW flow ahead of the approaching cold
front.
&&
.LONG TERM...(Tuesday through Monday)
ISSUED AT 306 PM CST MON FEB 16 2015
A very cold midweek forecast is shaping up. A surface cold front
will push southeastward across central Illinois through the day
Tuesday causing temperatures to level off early in the day and
eventually decrease in the late afternoon. Highs will range from the
mid teens to lower 20s. Areas northwest of the Illinois River may
see max temperatures before noon, while areas south of I-70 may see
max temperatures mid afternoon. Limited moisture will cause this to
have little precipitation associated with it, however scattered snow
flurries will be possible as the surface cold front and upper trough
cross the area. Brisk northwest winds of 10-15 mph will follow the
cold front causing very chilly conditions.
Another cold front will trail closely behind for early Wednesday
morning bringing in even colder temperatures and winds 15-20 mph
with gusts to the mid 20s. Low temperatures of around 0 to 5 degrees
above are expected Wednesday morning. This will result in wind chill
temperatures of -15 to -20 degrees as far south as I-72. This may
require the issuance of a wind chill advisory for these areas. A few
more snow flurries are possible along with the cold front. Sub-zero
temperatures will continue to spread southeastward across the region
by Thursday morning resulting in wind chill temperatures of -15 to
-25 degrees throughout central IL.
Temperatures will gradually moderate late in the week as the deep
trough over the central and eastern U.S. shifts eastward allowing a
southerly flow to develop along with some light warm frontal
precipitation by Friday into the weekend. Models still disagreeing on
whether a significant precipitation event could take shape over the
weekend. ECMWF model has been closest to this idea with a low
tracking northeastward across the southern tip of Illinois while GFS
and Canadian keep significant precipitation off to the south. ECMWF
has trended slightly southward in the 12Z solution versus last
nights 00Z solution.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1110 PM CST MON FEB 16 2015
Low VFR cigs spreading slowly east and southeast late this
evening and should encompass all TAF sites by 09z. Cold front
pushing across east central Iowa will bring about a wind shift
Tuesday morning into the west and northwest along with a period
of MVFR cigs immediately behind the frontal passage. Latest RAP
and HRRR forecasts suggest the MVFR cigs should push into PIA
around 09z and finally into CMI at 12z. Based on the past several
forecast runs, it appears about a 2-3 hour period of MVFR cigs
before improving to VFR by 15z at PIA and 18z over in CMI.
500 mb trof axis still located to our west on Tuesday so if we do
see any breaks in the cloud cover, the rather cold 500 mb temps
will lead to some scattered to broken stratocu clouds between
3000-4000 feet during the afternoon. At this point will include a
scattered group at 3500 feet. A few flurries will be possible with
or just behind the cold front tomorrow morning and possibly again
the afternoon but at this time it appears coverage will be quite
limited so have decided to hold off any mention of flurries in
this set of TAFs. Surface winds will be light southwest overnight
and switch into the west around dawn Tuesday and then into the
northwest as the front shifts off to our east. Wind speeds tonight
will be less than 10 kts and increase to between 10 and 15 kts
on Tuesday with a few gusts near 20 kts by late morning or early
afternoon, before diminishing around sunset.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...Barnes
LONG TERM...Onton
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1133 PM EST MON FEB 16 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 953 PM EST MON FEB 16 2015
A HIGH PRESSURE RIDGE WILL BRIEFLY BUILD IN OVERNIGHT WITH MAINLY
CLEAR SKIES AND COLD TEMPERATURES. THE UPPER TROUGH OVER THE AREA
WILL GET REINFORCED TUESDAY NIGHT WITH ANOTHER SHOT OF COLD AIR
THAT WILL BRING DANGEROUS COLD TO THE AREA TUESDAY NIGHT THROUGH
THURSDAY NIGHT. THE WEEKEND SHOULD BRING A WARMUP TO THE AREA BUT
WILL ALSO BRING ADDITIONAL CHANCES FOR ACCUMULATING SNOW.
&&
.NEAR TERM /OVERNIGHT/...
ISSUED AT 953 PM EST MON FEB 16 2015
SNOW HAS DEPARTED OUT OF THE FORECAST AREA WITH FAIRLY RAPID
CLEARING AS A HIGH PRESSURE RIDGE BUILDS ACROSS THE AREA. TEMPS
VARIED WIDELY AT 0230Z...RANGING FROM NEAR 0 DEGREES IN SOME
LOCATIONS WITH A SNOWPACK TO THE TEENS IN OTHER SPOTS.
AFTER THE SNOWFALL TODAY...RELATIVELY QUIET FORECAST SETS UP
OVERNIGHT WITH THE ONLY REAL ISSUE FOCUSED ON THE LOW TEMPS. HIGH
PRESSURE RIDGE WILL DRIFT EAST ACROSS THE OHIO VALLEY TONIGHT WITH
STRATUS BACK OVER THE MISSISSIPPI VALLEY HOLDING OFF UNTIL LATE
TONIGHT IN THE WEST AND LIKELY CLOSER TO DAYBREAK OVER EASTERN
COUNTIES. WITH MAINLY CLEAR SKIES EXPECTED FOR SEVERAL HOURS AND
LIGHT WINDS...TEMPERATURES WILL TUMBLE. COLDEST TEMPS WILL LIKELY
BE FOUND IN SOUTHERN COUNTIES WITH THE PRESENCE OF A FRESH AND IN
SOME SPOTS DEEP SNOWPACK. UTILIZED 00Z RAP FOR HOURLY TEMPS BUT IN
GENERAL...DROPPED LOWS IN SOME SPOTS SEVERAL DEGREES. DO EXPECT
NORMAL COOL SPOTS OVER SOUTHERN FORECAST AREA WILL GO SUBZERO...
MAYBE AS LOW AS -5.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
ISSUED AT 348 PM EST MON FEB 16 2015
THE MAIN FOCUS IN THE SHORT TERM IS THE COLD TEMPERATURES AND WIND
CHILLS. MODELS ARE IN DECENT AGREEMENT ON PATTERN BUT MOS GUIDANCE
NUMBERS SHOWING SOME DIFFERENCES AND WILL DISCUSS PREFERENCE AND
REASONING BELOW.
A LARGE UPPER TROUGH WILL CONTINUE TO HOLD SWAY OVER THE EASTERN U.S
THROUGH THE SHORT TERM. THIS WILL ALLOW FOR A STEADY STREAM OF COLD
AIR INTO CENTRAL INDIANA. GIVEN MODEL 850 MB TEMPERATURES STARTING
IN THE -TEENS AND DROPPING INTO THE -22 TO -28 RANGE HAVE FAVORED
THE COLDER GUIDANCE NUMBERS OF THE MAV...AND HAVE EVEN DROPPED SOME
FROM THERE AT TIMES. LOWS TUESDAY NIGHT/WEDNESDAY MORNING WILL BE IN
THE LOW SINGLE DIGITS TO BELOW ZERO OVER THE SOUTHERN AREAS WITH
SNOWPACK FROM TODAY. WEDNESDAY NIGHT COULD SEE LOWS FROM A FEW
DEGREES BELOW ZERO TO NEAR 10 BELOW ZERO OVER THE SNOWPACK. HIGHS ON
WEDNESDAY AND THURSDAY WILL BE MAINLY IN THE SINGLE DIGITS.
WITH CYCLONIC FLOW LOOK FOR MOSTLY CLOUDY SKIES TO BE THE RULE ALONG
WITH SOME SLIGHT CHANCES FOR LIGHT SNOW AND BETTER CHANCES FOR
FLURRIES OFF AND ON. THERE IS SOME DISCERNIBLE UPPER FORCING TUESDAY
EVENING AND AGAIN ON WEDNESDAY BUT WITH LITTLE MOISTURE TO WORK WITH
WILL JUST CARRY SLIGHT CHANCES.
WILL LIKELY NEED HEADLINES FOR WIND CHILLS WEDNESDAY AND
THURSDAY...BUT GIVEN THE NUMBER OF PERIODS OUT AND CURRENT
HEADLINES RUNNING WOULD PREFER TO WAIT PAST THIS ISSUANCE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 245 PM EST MON FEB 16 2015
TEMPERATURES AND POPS INCLUDING TIMING AND PRECIP TYPE WILL BE THE
MAIN CONCERN FOR THE EXTENDED. AT THIS TIME...EXTENDED MODELS AND
ENSEMBLES ARE TOO FAR APART TO CONFIDENTLY CHANGE THE REGIONAL
BLEND...SO LEFT IT AS IT IS WITH CHANCE POPS STARTING FRIDAY NIGHT
AS A WARM FRONT LIFTS UP FROM THE SOUTHWEST. POPS IN ORDER THROUGH
LATE WEEKEND WITH SOUTHERLY FLOW AHEAD OF A FRONTAL SYSTEM. COULD
SEE A WINTRY MIX ACROSS OUR FAR SOUTHERN ZONES..BUT AT THIS POINT
WILL LEAVE IT ALL SNOW AND ADJUST AS IT GETS CLOSER AND OR MODELS
CONVERGE UPON A COMMON SOLUTION.
TEMPERATURES SHOULD START OFF COLD WITHIN DEPARTING ARCTIC HIGH
PRESSURE BUT THEN WARM TO CLOSER TO NORMAL BY SATURDAY AS THE WARM
FRONT MOVES THROUGH. STILL...EVEN THEN AND MORE SO AFTER THE COLD
FRONTAL PASSAGE...BELOW NORMAL TEMPERATURES WILL CONTINUE.
&&
.AVIATION /DISCUSSION FOR THE 170600Z TAFS/...
ISSUED AT 1133 PM EST MON FEB 16 2015
SYNOPTIC PATTERN FAVORS FOG DEVELOPMENT OVERNIGHT OVER FRESH SNOW
COVER IN THE KBMG AND POSSIBLY THE KHUF AREAS. WILL ADD SOME
VISIBILITY RESTRICTIONS IN FOG IN THE KBMG AREA THROUGH THE MID
MORNING HOURS OF TUESDAY. AT THIS TIME...APPEARS ANY IFR
RESTRICTIONS WILL BE FAIRLY BRIEF AND LOCALIZED...SO WILL KEEP
CONDITIONS ABOVE IFR. CONFIDENCE IN VISIBILITY RESTRICTIONS AT KHUF
IS LOWER...SO WILL LEAVE OUT THERE.
OTHERWISE...VFR DECK 040-050 PUSHING SOUTHEAST THROUGH NORTHERN
ILLINOIS EXPECTED TO BEGIN MOVING INTO THE TAF SITES FROM THE
NORTHWEST AFTER 170900Z. MVFR CEILINGS AROUND 025 SHOULD BEGIN TO
DEVELOP TOWARDS MIDDAY TUESDAY AS LOWER LEVEL LAPSE RATE STEEPEN. A
FEW LIGHT SNOW SHOWERS MAY DEVELOP TOWARDS MIDDAY AS WELL...BUT
POTENTIAL FOR VISIBILITY RESTRICTIONS LOOK LOW AT THIS TIME.
MORE WIDESPREAD SNOW SHOWER ACTIVITY POSSIBLE AFTER 171800Z AS A
FRONT MOVES THROUGH.
LIGHT SURFACE WINDS OVERNIGHT EXPECTED TO BECOME 240-270 DEGREES AT
8-11 KTS BY MIDDAY TUESDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP/RYAN
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM...MK
AVIATION...JAS
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
1226 AM MST TUE FEB 17 2015
.UPDATE...
ISSUED AT 706 PM MST MON FEB 16 2015
CURRENT FORECAST CONCERN WILL BE HOW FAR SOUTH CURRENT AREA OF
SNOW IN NORTHERN NEBRASKA GETS BEFORE DIMINISHING. H85-H7 LAPSE
RATES REMAIN FAVORABLE FOR THE NEXT 2 HOURS BUT BEGIN TO DECREASE
AFTER THAT. GIVEN THE CURRENT MOTION...DOUBTFUL ATMOSPHERE WILL BE
AS UNSTABLE BY THEN AND AM GOING TO LEAN TOWARDS PRECIP NOT MAKING
IT...BUT WILL KEEP AN EYE ON THINGS. OTHERWISE...ANOTHER ROUND OF
SNOW SHOWERS APPEARS POSSIBLE TOMORROW AND FINE TUNED POPS A BIT
TO HIGHLIGHT MOST LIKELY AREAS.
POTENTIAL FOR STRONG WINDS REMAINS...ALTHOUGH STRONGEST (50KT)
WINDS APPEAR TO BE ABOVE THE DRY ADIABATIC MIXED LAYER. WHILE A
PARCEL COULD POTENTIALLY MIX DOWN THE STRONGER WINDS...THINK IT IS
MORE LIKELY THAT CLOUDS AND SHOWERS WOULD LIMIT POTENTIAL FOR
BRINGING THESE WINDS INTO THE BOUNDARY LEVEL.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 208 PM MST MON FEB 16 2015
LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS BROAD TROUGH
ACROSS THE EASTERN US WITH SHORTWAVE ALONG BASE OF TROUGH OVER
COLORADO. AT THE SURFACE LOW PRESSURE REMAINS IN PLACE OVER NORTH
CENTRAL KANSAS...WITH HIGH PRESSURE ACROSS THE NORTHERN ROCKIES
EXTENDING SOUTH TOWARDS NORTHERN COLORADO.
STEEP LOW LEVEL LAPSE RATES AND WEAK INSTABILITY HAVE LED TO
RAIN/SNOW SHOWER DEVELOPMENT THIS AFTERNOON ACROSS THE CWA.
GRAUPEL HAS BEEN OBSERVED WITH SOME OF THIS ACTIVITY. THIS
ACTIVITY WILL MAINLY BE TIED TO DAYTIME HEATING...QUICKLY ENDING
AS LOW LEVELS STABILIZE NEAR SUNSET. THERE WILL BE SOME WEAK
FORCING AROUND THE REGION OVERNIGHT...HOWEVER OTHER THAN MAYBE A
FEW FLURRIES IT DOESN`T APPEAR TO BE SUPPORTIVE OF MEASURABLE
PRECIP.
BETTER FORCING IS PROGGED TO MOVE THROUGH THE REGION BY 12Z
TUESDAY AS POSITIVE MID LEVEL VORTICITY ASSOCIATED WITH SHORTWAVE
TROUGH ROTATES INTO THE REGION. THIS WILL RESULT IN SHOWER
REDEVELOPMENT FROM THE NORTH TO THE SOUTH...INCREASING IN COVERAGE
AS LAPSE RATES STEEPEN WITH DAYTIME HEATING. I COULD SEE A
RAIN/SNOW/ICE PELLET MIX AGAIN LIKE TODAY...WITH MINIMAL TO NO
ACCUMULATIONS. UNIDIRECTIONAL GRADIENT AND WINDS ALOFT INCREASE
DURING THE DAY...AND IF WE WERE TO MIX TO 700MB WE COULD SEE
WARNING CRITERIA WINDS MIX TO THE SURFACE. MIXING HEIGHTS APPEAR
TO BE LIMITED DUE TO INCREASING CLOUD COVER...THOUGH THERMAL
PROFILES IN CLEAR SKIES COULD SUPPORT MUCH DEEPER MIXING. FOR NOW
I KEPT GUSTS 45-50MPH. THERE IS A CONCERN THAT SHOWERS COULD HELP
MIX STRONGER WINDS TO THE SURFACE. WINDS COULD ALSO COMBINE WITH
SHOWERS TO REDUCE VISIBILITIES.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 1209 AM MST TUE FEB 17 2015
PATTERN CHANGE WILL GET UNDERWAY AT THE BEGINNING OF THE PERIOD AS
A LONGWAVE TROUGH DIGS INTO THE CENTRAL CONUS. EVENTUALLY AN
UPPER LOW WILL PINCH OFF OVER THE GREAT BASIN AND A STRONG TROUGH
SETTLE INTO THE GREAT LAKES. BOTTOM LINE FOR THE CENTRAL HIGH
PLAINS WILL BE BELOW NORMAL TEMPERATURES AND OCCASIONAL CHANCES
FOR SNOW. THOSE SNOW CHANCES WILL BEGIN FRIDAY NIGHT AND CONTINUE
THROUGH MONDAY...WITH BEST CHANCES ON SATURDAY. ECMWF AND GFS
BOTH AGREE THAT THERE WILL BE SNOW...BUT HAVE HUGE DIFFERENCES IN
THE AMOUNTS. THE COLORADO FRONT RANGE WILL SEE THE MOST WITH GOOD
LOW LEVEL UPSLOPE FORECAST. BEST ESTIMATE AT THIS TIME WOULD BE A
MODERATE SNOWFALL IN THE 3 TO 6 INCH RANGE...HIGHEST AMOUNTS IN
EASTERN COLORADO...BUT CONFIDENCE IS LOW DUE TO AFOREMENTIONED
MODEL INCONSISTENCIES WITH AMOUNTS. THIS WILL NOT BE A CLOSED
UPPER LOW SITUATION SO WIND AND AND BLOWING SNOW DO NOT APPEAR TO
BE A THREAT AT THIS TIME. AS FOR TEMPERATURES...SUNDAY AND MONDAY
WILL BE THE COLDEST DAYS WITH TEMPERATURES NOT LIKELY GETTING OUT
OF THE 20S...THEN SOME MODEST WARMING TO START THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1030 PM MST MON FEB 16 2015
VFR CONDITIONS WILL CONTINUE THROUGH 12Z WITH DECAYING SNOW
SHOWERS AROUND MCCOOK BRINGING A BRIEF 4000FT CIG TONIGHT...BUT NO
PREVAILING REDUCED FLIGHT CATEGORIES. CONFIDENCE HAS LOWERED A BIT
IN MVFR CIGS AROUND MCCOOK IN THE 12-18Z PERIOD...BUT GIVEN
EXPECTED T-TD SPREADS AND SNOW SHOWERS IN THE AREA AM GOING TO
KEEP THINGS AROUND 2500 FEET FOR A PORTION OF THE DAY. WINDS STILL
LOOK TO REMAIN STRONG FROM 15Z THROUGH 23Z WITH GUSTS EXCEEDING
40KTS DURING THE EARLY AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...DR
LONG TERM...024
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1038 PM MST MON FEB 16 2015
.UPDATE...
ISSUED AT 706 PM MST MON FEB 16 2015
CURRENT FORECAST CONCERN WILL BE HOW FAR SOUTH CURRENT AREA OF
SNOW IN NORTHERN NEBRASKA GETS BEFORE DIMINISHING. H85-H7 LAPSE
RATES REMAIN FAVORABLE FOR THE NEXT 2 HOURS BUT BEGIN TO DECREASE
AFTER THAT. GIVEN THE CURRENT MOTION...DOUBTFUL ATMOSPHERE WILL BE
AS UNSTABLE BY THEN AND AM GOING TO LEAN TOWARDS PRECIP NOT MAKING
IT...BUT WILL KEEP AN EYE ON THINGS. OTHERWISE...ANOTHER ROUND OF
SNOW SHOWERS APPEARS POSSIBLE TOMORROW AND FINE TUNED POPS A BIT
TO HIGHLIGHT MOST LIKELY AREAS.
POTENTIAL FOR STRONG WINDS REMAINS...ALTHOUGH STRONGEST (50KT)
WINDS APPEAR TO BE ABOVE THE DRY ADIABATIC MIXED LAYER. WHILE A
PARCEL COULD POTENTIALLY MIX DOWN THE STRONGER WINDS...THINK IT IS
MORE LIKELY THAT CLOUDS AND SHOWERS WOULD LIMIT POTENTIAL FOR
BRINGING THESE WINDS INTO THE BOUNDARY LEVEL.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 208 PM MST MON FEB 16 2015
LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS BROAD TROUGH
ACROSS THE EASTERN US WITH SHORTWAVE ALONG BASE OF TROUGH OVER
COLORADO. AT THE SURFACE LOW PRESSURE REMAINS IN PLACE OVER NORTH
CENTRAL KANSAS...WITH HIGH PRESSURE ACROSS THE NORTHERN ROCKIES
EXTENDING SOUTH TOWARDS NORTHERN COLORADO.
STEEP LOW LEVEL LAPSE RATES AND WEAK INSTABILITY HAVE LED TO
RAIN/SNOW SHOWER DEVELOPMENT THIS AFTERNOON ACROSS THE CWA.
GRAUPEL HAS BEEN OBSERVED WITH SOME OF THIS ACTIVITY. THIS
ACTIVITY WILL MAINLY BE TIED TO DAYTIME HEATING...QUICKLY ENDING
AS LOW LEVELS STABILIZE NEAR SUNSET. THERE WILL BE SOME WEAK
FORCING AROUND THE REGION OVERNIGHT...HOWEVER OTHER THAN MAYBE A
FEW FLURRIES IT DOESN`T APPEAR TO BE SUPPORTIVE OF MEASURABLE
PRECIP.
BETTER FORCING IS PROGGED TO MOVE THROUGH THE REGION BY 12Z
TUESDAY AS POSITIVE MID LEVEL VORTICITY ASSOCIATED WITH SHORTWAVE
TROUGH ROTATES INTO THE REGION. THIS WILL RESULT IN SHOWER
REDEVELOPMENT FROM THE NORTH TO THE SOUTH...INCREASING IN COVERAGE
AS LAPSE RATES STEEPEN WITH DAYTIME HEATING. I COULD SEE A
RAIN/SNOW/ICE PELLET MIX AGAIN LIKE TODAY...WITH MINIMAL TO NO
ACCUMULATIONS. UNIDIRECTIONAL GRADIENT AND WINDS ALOFT INCREASE
DURING THE DAY...AND IF WE WERE TO MIX TO 700MB WE COULD SEE
WARNING CRITERIA WINDS MIX TO THE SURFACE. MIXING HEIGHTS APPEAR
TO BE LIMITED DUE TO INCREASING CLOUD COVER...THOUGH THERMAL
PROFILES IN CLEAR SKIES COULD SUPPORT MUCH DEEPER MIXING. FOR NOW
I KEPT GUSTS 45-50MPH. THERE IS A CONCERN THAT SHOWERS COULD HELP
MIX STRONGER WINDS TO THE SURFACE. WINDS COULD ALSO COMBINE WITH
SHOWERS TO REDUCE VISIBILITIES.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 141 PM MST MON FEB 16 2015
WITH THE PASSAGE OF THE SHORTWAVE THRU THE CWA ON TUESDAY...THE TRI
STATE REGION WILL TREND INTO A DRY PERIOD FROM TUESDAY NIGHT RIGHT
INTO 12Z FRIDAY. DURING THIS TIMEFRAME...H5 RIDGE WILL FLATTEN SOME
OVER THE WESTERN PORTION OF THE COUNTRY...ALLOWING FOR WNW FLOW OVER
THE AREA. AT THE SURFACE...HIGH PRESSURE SLIDES SOUTH FROM CANADA
SHIFTING EAST THRU THE WEEK...AND A LEE-SIDE TROUGH SETS UP OVER THE
EASTERN SIDE OF THE ROCKIES. INCREASING WAA WILL RESULT AS SOUTHERLY
FLOW TAPS INTO WARMER AIR. FROM FRIDAY ON THRU NEXT MONDAY...
SHORTWAVE WILL PINWHEEL AROUND BROAD UPPER LOW TO THE EAST...SETTING
UP OVER THE ROCKIES. BLOCKING PATTERN OFF THE WEST COAST...AS WELL
AS OVER THE CENTRAL ATLANTIC OCEAN...KEEPS UPPER TROUGH OVER THE
ROCKIES. THIS SYSTEM WILL BE ABLE TO TAP INTO PACIFIC MOISTURE...
FEEDING IT INTO THE REGION FOR THE PERIOD. AT THE SURFACE HIGH
PRESSURE AGAIN BUILDING DOWN FROM CENTRAL CANADA WILL PROVIDE AN
EASTERLY/UPSLOPE FETCH INTO THE REGION. THE RESULT WILL BE CHANCE
POPS FOR -SW THRU THE ENTIRE FRIDAY THRU MONDAY TIMEFRAME WITH LIGHT
SCATTERED AMOUNTS. A WAA TREND FOR THE FIRST HALF OF THE EXTENDED
WILL GIVE WAY TO BELOW NORMAL NUMBERS WITH THE ARRIVAL OF THE COLD
CANADIAN RIDGE. OVERALL HIGHS WILL RANGE FROM THE 40S WEDNESDAY UP
TO NEAR 60F FOR THURS/FRI...THEN DROP DOWN INTO THE 20S TO L30S FOR
THE WEEKEND INTO NEXT MONDAY. OVERNIGHT LOWS WILL SEE BIG DROP AT
THE END OF THE WEEK WITH CANADIAN RIDGE OVER AREA. LOWS WILL RANGE
FROM THE TEENS AND MID 20S THRU FRIDAY NIGHT...THEN DOWN TO THE
TEENS AND SINGLE NUMBERS OVER THE UPCOMING WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1030 PM MST MON FEB 16 2015
VFR CONDITIONS WILL CONTINUE THROUGH 12Z WITH DECAYING SNOW
SHOWERS AROUND MCCOOK BRINGING A BRIEF 4000FT CIG TONIGHT...BUT NO
PREVAILING REDUCED FLIGHT CATEGORIES. CONFIDENCE HAS LOWERED A BIT
IN MVFR CIGS AROUND MCCOOK IN THE 12-18Z PERIOD...BUT GIVEN
EXPECTED T-TD SPREADS AND SNOW SHOWERS IN THE AREA AM GOING TO
KEEP THINGS AROUND 2500 FEET FOR A PORTION OF THE DAY. WINDS STILL
LOOK TO REMAIN STRONG FROM 15Z THROUGH 23Z WITH GUSTS EXCEEDING
40KTS DURING THE EARLY AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...DR
LONG TERM...JN
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS JACKSON KY
1225 AM EST TUE FEB 17 2015
.UPDATE...
ISSUED AT 1225 AM EST TUE FEB 17 2015
UPDATED TO EXPIRE WESTERN SEGMENTS OF THE WINTER STORM WARNING AND
REPLACED IT WITH AN SPS TO HIGHLIGHT TREACHEROUS ROAD CONDITIONS
INTO THE DAY TUESDAY. ALSO UPDATED TO REMOVE POPS FROM OUR WESTERN
AREAS AS SNOW HAS ENDED. LOOKS LIKE SNOW SHOULD MOVE ON OUT BY 08Z
WITH THE LAST SEGMENTS OF THE WINTER STORM WARNING BEING ALLOWED
TO EXPIRE.
UPDATE ISSUED AT 1055 PM EST MON FEB 16 2015
THE BACK EDGE OF THE STEADIER SNOW OR FLURRIES HAS WORKED EAST OF
INTERSTATE 75 PER RADAR IMAGERY AND REGIONAL OBSERVATIONS.
HOWEVER...SOME ENHANCED RETURNS REMAIN IN THE FAR SOUTHEAST...BUT
THIS BAND SHOULD GRADUALLY MOVE INTO VA AND WV OVER THE NEXT HOUR.
NEAR TERM MODELS...SUCH AS THE HRRR RUNS HAVE ALL THE SNOW IN THE
FAR SOUTHEAST ENDING BY 7Z TO 8Z...OR 2 TO 3 AM. AT THIS TIME...WE
PLAN TO ALLOW THE WARNINGS TO RUN THEIR COURSE AND THEN REPLACE
WITH AN SPS FOR THE REMAINDER OF THE OVERNIGHT.
UPDATE ISSUED AT 755 PM EST MON FEB 16 2015
THE STEADIER SNOW HAS TAPERED OFF...BUT LIGHT TO MODERATE SNOW
REMAINS AND THERE ARE SOME ENHANCED AREAS OF REFLECTIVITY ACROSS
THE SOUTHEASTERN COUNTIES. THE THREAT FOR AT LEAST LIGHT SNOW WILL
REMAIN UNTIL THE UPPER LEVEL TROUGH MOVES THROUGH. EVEN WITH RATES
HAVING DECREASED...SNOW COVERED ROADS REMAIN AND EVEN ANY LIGHT
ADDITIONAL SNOW WILL IMPACT TRAVEL AND BEGIN TO FILL BACK IN ROADS
THAT HAVE BEEN PLOWED. ATTM...PLANS OUR TO LET THE WINTER STORM
WARNINGS WILL BE ALLOWED TO RUN THEIR COURSE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 415 PM EST MON FEB 16 2015
A WINTER STORM TRACKING ACROSS THE SOUTHEASTERN STATES WILL REACH
THE CAROLINA COASTLINE LATE TONIGHT AND THEN OFF THE EAST COAST
BY TUESDAY MORNING. A WESTERN RIDGE AND EASTERN TROUGH PATTERN IS
EXPECTED THROUGH MIDWEEK. A DEEP CLOSED LOW WILL DIVE SOUTH TOWARD
THE GREAT LAKES AND SOUTHERN ONTARIO AND BRING THE BEGINNING OF
ANOTHER ARCTIC BLAST LATE STARTING ON TUESDAY NIGHT. THIS WINTER
STORM IS BRINGING THE MOST WIDESPREAD IMPACTS AS FAR AS SNOWFALL
TO THE REGION IN THE LAST 10 TO 20 YEARS. IN MANY PLACES...THE
SNOW HAS BEEN ON THE DRIER SIDE...WHICH IS LIMITING POWER OUTAGE
POTENTIAL. SOME LOWER RATIO SNOW IS LIKELY FALLING CLOSER TO THE
VA AND TN BORDERS WHERE THE ATMOSPHERE IS WARMER. THIS LOW
THE WINTER STORM CONTINUES TO AFFECT THE REGION AND IT IS LEADING
TO TOTALS NEAR DOUBLE DIGITS IF NOT NEARLY A FOOT OR MORE ATTM.
AS THE SHORTWAVE TROUGH APPROACHES THE AREA THE LATEST SHORT TERM
GUIDANCE SUGGEST MODERATE TO HEAVY SNOW HANGING ON THROUGH LATE
EVENING WITH RATES OF 1 TO 2 INCH PER HOUR AT TIMES. LOCATIONS
NEAR THE TN AND VA BORDERS...SHOULD ALSO EXPERIENCE AN END TO MIX
WITH FREEZING RAIN AND SLEET. THE SNOW SHOULD WIND DOWN BY
MIDNIGHT OR 1 AM IN MOST LOCATIONS. AN ADDITIONAL TWO OR THREE TO
SEVEN INCHES SHOULD FALL THROUGH THE END OF THE EVENT.
A RIDGE OF HIGH PRESSURE WILL BRING A RESPITE TO THE SNOW CHANCES
AS THE LOW DEPARTS...BUT ADDITIONAL SNOW SHOWERS ARE POSSIBLE LATE
ON TUESDAY AS A WAVE TRACKS INTO THE MID SOUTH. THE THREAT FOR THE
SNOW SHOWERS WILL LINGER THROUGH THE END OF THE PERIOD AS AN
ARCTIC BOUNDARY APPROACHES AND CROSSES THE AREA. THE THREAT FOR
THESE SNOW SHOWERS WILL LINGER INTO THE LONG TERM PERIOD.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 355 PM EST MON FEB 16 2015
ALL EYES TURN TO A ARCTIC COLD FRONT DROPPING SOUTHEAST THROUGH
THE DAY ON WEDNESDAY. SPOKE OF UPPER LEVEL ENERGY FROM A QUASI
STATIONARY UPPER LEVEL CLOSED LOW ACROSS CANADA WILL BRING ARCTIC
AIR SOUTH INTO THE OHO VALLEY. THERE WILL BE SOME MOISTURE WITH
THIS FRONT AND COUPLED WITH SURFACE TO 3 KM LAPSE RATES 8 C/KM
BASED ON NAM...GIVEN THIS WOULD EXPECT THERE TO ONCE AGAIN BE SNOW
SQUALLS ACROSS THE REGION ESPECIALLY IN THE AFTERNOON ON
WEDNESDAY. THESE SQUALLS WILL BE ACCOMPANIED BY STRONG WINDS AND
WHITE OUT CONDITIONS. THIS UNSTABLE ATMOSPHERE PRESENTED BY THE
GUIDANCE WOULD ALSO SUPPORT ISOLATED THUNDERSNOW IN HEAVIER SNOW
SQUALLS. THIS INSTABILITY AND MOISTURE ARE PERSISTENT EVEN INTO
THE EVENING. BEHIND THIS FRONT EXPECT TEMPERATURES TO QUICKLY FALL
THROUGH THE EVENING WEDNESDAY INTO THE SINGLE DIGITS. THURSDAY
MORNING LOWS BOTTOM OUT INTO THE NEG SINGLE DIGITS WITH WIND
CHILLS WELL INTO THE NEG TEENS IN MANY SPOTS. THIS COLD AIR
PERSISTS THROUGH FRIDAY. HIGH PRESSURE TRIES TO BUILD EAST AND
FLOW AROUND THE HIGH COULD KEEP SOME MOISTURE ACROSS THE REGION
AND HAVE OPTED TO KEEP SOME FLURRIES. THIS HIGH PRESSURE WILL
PROGRESS EAST AND THEN WE START LOOKING AT THE NEXT SYSTEM MOVING
IN FOR THE WEEKEND. RIGHT NOW THERE CONTINUES TO BE A FAIR AMOUNT
OF UNCERTAINTY IN THE MODELS AT THIS POINT ON EXACTLY WHERE THE
ACCESS OF BEST QPF LINES UP. THAT SAID THE PROFILES ALSO SUPPORT
SNOW TO MIX AND RAIN THROUGH THE DAY ON SATURDAY. THERE CONTINUES
TO BE QUESTION AS TO PRECIP TYPE ALONG WITH HOW MUCH RAIN. THE
CONCERN WOULD CONTINUE TO BE HOW MUCH RAIN AND HOW MUCH SNOW
LINGERS GIVEN COLD TEMPERATURES UP TO THIS. RIGHT NOW KEPT CLOSE
TO SUPERBLEND IN THIS PART OF LONG TERM UNTIL BETTER AGREEMENT CAN
BE SEEN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1225 AM EST TUE FEB 17 2015
SOME LIGHT SNOW CONTINUES TO HOLD OVER FAR EASTERN KENTUCKY...BUT
THIS WILL BE ON THE WAY OUT OVER THE NEXT FEW HOURS. IN THE WAKE
OF THE SNOW...MVFR CIGS WILL LINGER...BORDERING ON IFR AT TIMES
THROUGH DAYBREAK. VFR CONDITIONS WILL TEMPORARILY MOVE BACK IN BY
MID MORNING TUESDAY WITH A GOOD DEAL OF SUNSHINE ANTICIPATED. OUR
NEXT WEATHER SYSTEM WILL MOVE IN LATE TUESDAY EVENING AND
ESPECIALLY OVERNIGHT WHICH WILL BRING THE THREAT OF LOW CIGS TO
THE AREA ONCE MORE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 3 AM EST EARLY THIS MORNING FOR
KYZ087-088-107-109-110-112-113-115-117>120.
&&
$$
UPDATE...KAS
SHORT TERM...JP
LONG TERM...DJ
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1146 PM CST MON FEB 16 2015
.UPDATE...
ISSUED AT 955 PM CST MON FEB 16 2015
SHORTWAVE IN THE NORTHWEST FLOW ALOFT PRODUCED SOME HALF TO 1.5
INCH AMOUNTS OUT WEST. THIS FEATURE TO DIVE SOUTH OVERNIGHT WITH
REINFORCING COLD AIR AND STRENGTHENING WINDS FOR TUESDAY. WITH
VERY COLD TEMPERATURES...WILL NOT TAKE MUCH TO GET FLURRIES OR
PATCHY LIGHT SNOW. LIGHT SNOW HAS BEEN PATCHY OVER A COUPLE OF
COUNTIES AS IT DROPS SOUTH. FRONTOGENESIS INCREASES AS IT DROPS
SOUTH. THE HI RES MODELS CONFINE THE ACCUMULATING SNOW TO THE
SOUTHWEST PART OF OUR FORECAST AREA AND THE NEW NAM BRUSHES THE
WESTERN COUNTIES AS WELL. WILL MAINTAIN SOME LIGHT ACCUMULATIONS
FOR THE WESTERN/SOUTHWEST AREAS OVERNIGHT. SOME OF THE LIGHT SNOW
AND FLURRIES MAY CONTINUE INTO TUESDAY.
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 300 PM CST MON FEB 16 2015
THE PRIMARY FORECAST CONCERN IS POTENTIAL FOR A BAND OF ACCUMULATING
SNOW ACROSS PARTS OF EASTERN NEBRASKA TONIGHT.
UPPER AIR CHARTS FROM 12Z HAD THE FOLLOWING MAIN FEATURES. A STRONG
JETSTREAM WAS NOTED AT 300 MB FROM ALBERTA INTO UTAH...WITH A
COUPLE OF JET SEGMENTS OF OVER 130 KNOTS. A STRONGER JET SEGMENT
OF AROUND 170 KNOTS WAS OVER PENNSYLVANIA. A BROAD AREA OF 12 HOUR
HEIGHT FALLS OF 50 METERS OR MORE AT 500 MB EXTENDED FROM UTAH TO
IOWA AND FROM SOUTH DAKOTA TO TEXAS. A STRONG RIDGE WAS LOCATED
FROM OFF THE CALIFORNIA COAST UP INTO THE YUKON. WINDS WERE
GENERALLY FROM THE NORTHWEST IN THE LOWER AND MIDDLE TROPOSPHERE
FROM OUR AREA NORTHWEST INTO CANADA. PREVIOUSLY MENTIONED 500 MB
RIDGE TO OUR WEST WILL BUILD EAST AND THEN FLATTEN THROUGH
THURSDAY...WHILE A CLOSED LOW FORMS AND DROPS SOUTHEAST ACROSS
ONTARIO AND INTO THE EASTERN GREAT LAKES REGION.
A FAST MOVING SHORTWAVE IN COMBINATION WITH A COMPACT LOW PRESSURE
CENTER SHOULD BRING A BAND OF LIGHT SNOW TO THE REGION TONIGHT.
THE EXACT PLACEMENT OF THIS BAND IS SOMEWHAT UNCERTAIN...BUT THE
LATEST MODEL CONSENSUS (USING A BLEND OF 12Z NAM...18Z NAM...19Z
13 KM RAP ...18Z HRRR AND 15Z SREF MEAN) PLACES THE AXIS FROM
PARTS OF NORTH CENTRAL NEBRASKA INTO NORTHEAST KANSAS. BEST
POTENTIAL IS LIKELY JUST NORTH AND NORTHEAST OF THE TRACK OF THE
SURFACE LOW PRESSURE CENTER. SOUNDINGS...MID LEVEL FRONTOGENESIS
AND IMPRESSIVE 700 MB OMEGA VALUES IN THE DENDRITIC GROWTH ZONE
FROM THE NAM SUGGEST THE ATMOSPHERE MAY PRODUCE SOME AMOUNTS OVER
ONE INCH IN PARTS OF CENTRAL OR SOUTHEAST NEBRASKA DOWN INTO
NORTHEAST KANSAS. BUT WE HAVE MAX AMOUNTS AROUND ONE INCH FOR NOW
AND WILL MENTION THE LOCALIZED POTENTIAL FOR HIGHER AMOUNTS IN THE
HWO. THAT SYSTEM SHOULD PUSH QUICKLY SOUTH OUT OF OUR AREA BY
ABOUT SUNRISE...BUT SOME ISOLATED TO SCATTERED SNOW SHOWERS MAY
OCCUR INTO THE AFTERNOON HOURS. AFTER THAT...SNOW CHANCES SEEM LOW
FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...BUT A SLIGHT CHANCE
OF SNOW WILL RETURN BY THURSDAY.
COLD CANADIAN HIGH PRESSURE WILL BE BUILDING SOUTH FROM ALBERTA
AND SASKATCHEWAN THROUGH WEDNESDAY. WIND CHILLS MAY REACH NEAR
ADVISORY VALUES IN THE NORTH AND NORTHEAST PARTS OF THE FORECAST
AREA LATE TUESDAY NIGHT AND WEDNESDAY MORNING...BUT WILL NOT ISSUE
AN ADVISORY AT THIS POINT. THEN AS THE RIDGE MOVES OFF TO THE
SOUTHEAST AND SOUTHERLY RETURN FLOW DEVELOPS...TEMPERATURES WILL
MODERATE A BIT.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 300 PM CST MON FEB 16 2015
500 MB RIDGE WILL DEVELOP AGAIN FROM THE EASTERN PACIFIC UP INTO
THE YUKON FROM THURSDAY NIGHT INTO SUNDAY. LATEST RUNS OF THE
GFS... ECMWF AND CANADIAN MODELS AGREE ON THE GENERAL LARGE SCALE
FEATURES INTO SUNDAY. DETAILS START TO DIVERGE EARLY NEXT
WEEK...AND CONFIDENCE FALLS TO BELOW NORMAL BY THAT TIME. HAD TO
INCLUDE SOME LOW POPS FOR LIGHT SNOW CHANCES MUCH OF THIS PERIOD.
FRIDAY LOOKS LIKE THE WARMEST DAY...WHEN WE SHOULD SEE HIGHS IN
THE 40S WEST AND 30S EAST. LOWS WILL BE MOSTLY IN THE TEENS...BUT
UPPER TEENS TO MID 20S FOR FRIDAY NIGHT.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1135 PM CST MON FEB 16 2015
VFR CONDITIONS INITIALLY...WITH SOME PERIODS OF MVFR CIGS AND
PATCHY LIGHT SNOW THROUGH TUESDAY MORNING AS A WEATHER DISTURBANCE
MOVES THROUGH. SOME ECHOES SHOWING UP ON RADAR AND DID MENTION -SN
AT KLNK TONIGHT. ADDITIONAL LIGHT SNOW/FLURRIES MAY DEVELOP
TUESDAY MORNING. DUE TO UNCERTAINTY OF COVERAGE...FOR NOW JUST
MENTIONED AT KOFK BETWEEN 12-16Z. VARIABLE NORTHWEST WINDS 5 TO
15KT. NORTHWEST WINDS INCREASE TO 10-20KTS WITH GUSTS 25-30KTS
BEGINNING 16-18Z THEN DECREASE TO 10KTS OR LESS AFTER 00Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...ZAPOTOCNY
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1235 AM EST TUE FEB 16 2015
.SYNOPSIS...A LOW PRESSURE SYSTEM WILL STRENGTHEN OVER THE SOUTHEAST
U.S. OVERNIGHT...AND TRACK NORTHEAST ALONG THE CAROLINA COAST EARLY
TUESDAY MORNING.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 1050 PM MONDAY...
...CONDITIONS DETERIORATING ACROSS CENTRAL NC WITH WIDESPREAD
HAZARDOUS TRAVEL AND NUMEROUS POWER OUTAGES LIKELY...
...WINTER STORM WARNINGS REMAIN IN EFFECT...
HAVE UPGRADED THE FAR SE COUNTIES TO A WARNING AS THE NORTHERN
SECTIONS OF THESE COUNTIES HAVE THE POTENTIAL TO MEET OR EXCEED A
QUARTER OF AN INCH ICE ACCRUAL. TEMPS IN THIS REGION HOLDING IN THE
UPPER 20S AND WILL LIKELY REMAIN AT OR BELOW 30 DEGREES...ESPECIALLY
NORTH OF A CLINTON-FAYETTEVILLE-LAURINBURG LINE.
AREA SOUNDINGS AND LATEST HRRR SOUNDING DATA STILL DEPICT A DECENT
COLD NOSE -8 TO -10 DEGREES C WITH AN EQUALLY IMPRESSIVE WARM NOSE
OF 7 DEGREES C NEAR FAYETTEVILLE. STILL APPEARS THAT BULK OF PRECIP
WILL BE FREEZING RAIN OR A MIXTURE OF SLEET/FREEZING RAIN (DEPENDENT
ON PRECIP INTENSITY). THE LONGER THE PRECIP REMAINS MIXED...THE LESS
ICE ACCRETION WILL OCCUR BUT STILL ENOUGH TO CREATE DANGEROUS ICE
ACCRUAL ON POWERLINES AND TREES. IF PRECIP WERE TO GO MORE TOWARD
ALL SLEET...SLEET ACCUMULATION OF AN INCH OR LITTLE MORE WILL OCCUR
AND ICE ACCRUAL WILL BE SEVERELY LIMITED.
WILL MAINTAIN WARNING ELSEWHERE BUT HAVE LOWERED "MAXIMUM" ICE
ACCRUAL BELOW A HALF INCH. -WSS
820 PM UPDATE...
PRECIP COVERAGE AND INTENSITY WILL BE INCREASING EXPONENTIALLY NEXT
FEW HOURS AS S/W AND ATTENDANT SFC LOW LIFTS E-NE OUT OF THE LOWER
MS VALLEY INTO THE DEEP SOUTH. THE SFC LOW...PER 23Z HRRR
MODEL...STILL PROJECTED TO TRACK IMMEDIATELY SOUTH-SE OF CENTRAL NC
OVERNIGHT.
00Z GSO SOUNDING DEPICTS SOME IMPRESSIVE DATA...ESPECIALLY THE 75KT
JET AT 6K FT. THIS JET PULLING WARMER AIR ALOFT OVER THE
REGION...CAUSING THE PRECIPITATION TYPE TO TRANSITION OVER TO MOSTLY
FREEZING RAIN SOUTH OF HIGHWAY 64...TO A MIXTURE OF SLEET/FREEZING
RAIN ACROSS THE NORTHERN PIEDMONT-NORTHERN/CENTRAL COASTAL PLAIN.
APPEARS MIXTURE SNOW/SLEET STILL FEASIBLE OVER THE FAR NORTHERN
TRIAD AND THE VIRGINIA BORDER COUNTIES THROUGH 10 PM-MIDNIGHT...BUT
EVEN HERE...APPEARS THAT FREEZING RAIN MIXED WITH SLEET WILL BE THE
DOMINATE PRECIP OVERNIGHT.
STILL APPEARS BULK OF PRECIPITATION WILL OCCUR BETWEEN 10 PM - 5
AM....WHEN BEST LIFT OCCURS IN CONJUNCTION WITH A 140KT JET LIFTING
NE ACROSS VA.
HAVE SEVERELY CUTBACK ON SNOW AMOUNTS ACROSS THE NORTHERN PIEDMONT
AND INCREASED ICING POTENTIAL IN VICINITY OF THE TRIAD. THE ICING
NUMBERS IN THE NW PIEDMONT MAY NEED TO BE ADJUSTED UPWARD AS NEW
DATA ARRIVES.
STILL APPEARS THAT A THREAT FOR A DEVASTATING ICE STORM IS A VERY
REAL POSSIBILITY IN A WEST-EAST BAND ACROSS SECTIONS OF PIEDMONT,
SANDHILLS AND COASTAL PLAIN. THIS THREAT APPEARS GREATEST IN
VICINITY OR JUST SOUTH OF HIGHWAY 64. STILL...AMOUNTS WILL BE
DEPENDENT UPON WHETHER PRECIP REMAINED MIXED OR PREDOMINATELY ONE OR
THE OTHER. THE MORE MIXTURE WE RECEIVE...ICE ACCRUAL AMOUNTS WILL BE
A LITTLE LESS. ALSO...IF PRECIPITATION FALLS MODERATE OR
HEAVILY...THIS WOULD LIMIT ICE ACCRUAL AS WELL. NEEDLESS TO
SAY...WITH TEMPERATURES IN THE 20S...ANY TYPE OF PRECIP THAT FALLS
WILL QUICKLY MAKE ROADS SLICK AND BECOMING QUITE
HAZARDOUS.
HAVE ALSO ADJUSTED ICING AMOUNTS IN THE FAR SE AS IT APPEARS ICE
ACCRUAL IN THIS REGION MAY BE A LITTLE LESS AS TEMPS HOVER NEAR OR
JUST BELOW FREEZING...LIMITING ICE ACCRETION.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 325 PM MONDAY...
A SHORTWAVE RESULTING FROM A MERGER OF A WAVE CURRENTLY DIVING
THROUGH THE ROCKIES AND THE SHEARING LOW OVER THE CALIFORNIA
BAJA...WILL ROUND THE BASE OF THE FULL-LATITUDE TROUGH AND CROSS THE
SOUTHEAST US TUESDAY NIGHT. DEEP MOISTURE AND THE SYNOPTIC FRONTAL
ZONE WILL BE OFFSHORE BY THEN...SO IT APPEARS THE RESULTING SURFACE
LOW AND PRECIP WILL ALSO BE OFFSHORE AS WELL. LOWS IN THE UPPER
TEENS TO MID 20S.
A SPEED MAX AND ASSOCIATED VORTICITY WILL DIVE THROUGH THE BACK SIDE
OF THE DEEP UPPER TROUGH AND CROSS THE AREA ON WEDNESDAY. FORECAST
SOUNDINGS SHOW SUFFICIENT MOISTURE FOR ICE IN THE -10 TO -20C
LAYER...WHICH ITSELF IS PRETTY LOW IN THIS ARCTIC AIRMASS. Q-VECTOR
CONVERGENCE INCREASE WEDNESDAY AFTERNOON...AND COMBINED WITH STEEP
LOW-LEVEL LAPSE RATES AND SOME WEAK INSTABILITY...SEEMS TO BE ENOUGH
SUPPORT FOR A LOW-END CHANCE OF SNOW SHOWERS AS THE NEXT ARCTIC
FRONT PLOWS THROUGH THE AREA. IF THESE SNOW SHOWERS WERE TO
DEVELOP...THERE COULD BE SOME TRAVEL CONCERNS GIVEN HOW COLD GROUND
TEMPERATURES WILL CONTINUE TO BE. HOWEVER...RATES WOULD NEED TO BE
HIGH AND CONFIDENCE IS VERY LOW AT THIS POINT. HIGHS WEDNESDAY ONLY
INT HE LOW TO MID 30S.
THE STRONG ARCTIC FRONT WILL BE EAST OF THE AREA WEDNESDAY NIGHT AND
THICKNESSES ARE FORECAST TO PLUMMET TO SOMEWHERE IN THE NEIGHBORHOOD
OF 1220M BOTH THURSDAY AND FRIDAY MORNING AS STRONG HIGH PRESSURE
SETTLES OVER HEAD BY FRIDAY. THE GFS IS MUCH COLDER THAN THE ECMWF
WITH 1200M...A VALUE THAT APPEARS TO HAVE BEEN REACH ONLY A COUPLE
TIMES IN THE PAST 50 YEARS. EVEN WITH THE WARMER ECMWF...LOWS WILL
BE IN THE LOW TI MID SINGLE DIGIT RANGE...AND A NEGATIVE TEMP CANT
BE RULED OUT AT THIS POINT. HIGHS THURSDAY LOOK TO ONLY BE IN THE
UPPER TEENS TO MID 20S BASED ON THICKNESS SCHEMES AND DRY ADIABATIC
MIXING. SLIGHTLY WARMER ON FRIDAY IN THE MID 20S TO LOWER 30S.THIS
WILL VERY LIKELY BE RECORD BREAKING COLD THAT WILL WARRANT SOME
PREPARATIONS AND EXTRA PRECAUTIONS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
AS OF 325 PM MONDAY...
...RECORD BREAKING AND DANGEROUSLY COLD CONDITIONS FOR THE SECOND
HALF OF THE WEEK...
THE PATTERN SHIFTS A LITTLE OVER THE WEEKEND AS THE UPPER LOW NEAR
THE HUDSON BAY FILLS IN AND THE UPPER LEVEL FLOW OVER THE SOUTHERN
US TURNS TO SOUTHWESTERLY. MODELS ARE SUGGESTIVE OF A SYSTEM
LIFTING FROM THE SOUTHWEST US THROUGH TOWARD THE MIDWEST.
HOWEVER...THE ECWMF AND GFS SHOW MARKEDLY DIFFERENTLY SOLUTIONS.
THE ECMWF SHOWS A STORM TRACK THROUGH THE OHIO VALLEY WHILE THE GFS
LINGERS THE ARCTIC FRONT NEAR OUR LATITUDE AND HAS A COUPLE "OVER-
RUNNING" EVENTS THAT COULD CAUSE SOME WINTRY WEATHER. GIVEN THE
IMPENDING STORM AND UNCERTAINTY...HAVE LEANED ON WPC FOR THIS PERIOD
WITH BASICALLY A CHANCE POPS THROUGH THE LATTER HALF OF THE WEEKEND
AND HIGHS REBOUNDING INTO THE UPPER 30S AND 40S.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 1235 AM MONDAY...
WIDESPREAD MVFR TO IFR CEILINGS IN A WINTRY MIX WILL CONTINUE ACROSS
THE AREA THROUGH 12 TO 15Z.
PREDOMINATE P-TYPE AT KINT AND KGSO WILL BE SLEET...MIXING WITH A
SOME FREEZING RAIN. KRDU AND KRWI...FREEZING RAIN MIXED WITH SLEET
WILL ALSO BE THE PREDOMINATE P-TYPE. KFAY WILL SEE MOSTLY FZRA.
GRADUAL IMPROVEMENT WILL BEGIN AFTER 15Z TUES... WITH ALL SITES
EXPECTED TO BECOME MVFR AND POSSIBLY VFR TUES AFTERNOON/EVENING.
ANOTHER STRONG ARCTIC COLD FRONT MAY BRING A BRIEF PERIOD OF MVFR
CEILINGS WITH SNOW SHOWERS WEDNESDAY AFTERNOON AND EVENING. HIGH
PRESSURE WILL BRING A HIGH LIKELIHOOD OF VFR CONDITIONS THURSDAY AND
FRIDAY... BEFORE ANOTHER SYSTEM POTENTIALLY IMPACTS THE AREA ON
SATURDAY.
&&
.CLIMATE...
...THE FOLLOWING ARE RECORD LOW AND LOW MAXIMUM TEMPERATURES FOR
FEBRUARY 16TH...19TH...AND 20TH...FOR GSO...RDU...AND FAY...
RECORD LOWS
GSO RDU FAY
FEBRUARY 16: 8 IN 1905 11 IN 1905 17 IN 1991
FEBRUARY 19: 12 IN 1979 11 IN 1979 8 IN 1958
FEBRUARY 20: 14 IN 1934 13 IN 1979 12 IN 1958
RECORD LOW MAXIMUMS
GSO RDU FAY
FEBRUARY 16: 27 IN 1958 30 IN 1943 33 IN 1943
FEBRUARY 19: 32 IN 1958 31 IN 1903 26 IN 1979
FEBRUARY 20: 29 IN 1947 32 IN 1947 37 IN 1972
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON EST TUESDAY FOR NCZ011-027-028-042-043-
077-078-085-088-089.
WINTER STORM WARNING UNTIL 9 AM EST TUESDAY FOR NCZ007>010-021>026-
038>041-073>076-083-084.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...BLS
LONG TERM...BLS
AVIATION...CBL
CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
330 AM CST TUE FEB 17 2015
.SHORT TERM (TODAY THROUGH WEDNESDAY)...FINAL PIECE OF MID LEVEL
FORCING IN THE BASE OF THE TROUGH WILL ROTATE THROUGH THE CWA THIS
MORNING. HAVE FOLLOWED SLIGHTLY CLOSER TO THE HRRR THROUGH MIDDAY
GIVEN THE BETTER HANDLING OF WHERE PRECIP IS CURRENTLY FALLING
ACROSS SOUTHERN AREAS OF SJT AND MAF CWAS. THAT SAID...THERE IS A
SIGNIFICANT DRY LAYER BELOW 800MB ACROSS NORTHERN AND EASTERN
AREAS OF THE CWA...WHICH MAY PREVENT MUCH OF THE PRECIP FROM REACHING
THE GROUND (ESPECIALLY NORTH OF A LLANO TO AUSTIN TO SCHULLENBURG
LINE). WHERE PRECIP DOES REACH THE GROUND...COLUMN WILL BE COOL
ENOUGH ALONG AND WEST OF I-35 FOR LIGHT SLEET OR SNOW FLURRIES TO
MIX IN...ESPECIALLY ACROSS CENTRAL AND WESTERN HILL COUNTRY. THERE
WAS SOME -SN REPORTED EARLIER IN OZONA. GROUND TEMPERATURES FOR
MOST LOCATIONS WILL REMAIN ABOVE FREEZING AND THEREFORE GENERALLY
NO ACCUMULATION IS EXPECTED. HOWEVER...CAN NOT RULE OUT SOME VERY
PATCHY...ELEVATED SURFACES ACROSS THE NORTHERN HILL COUNTRY SEEING
SOME VERY LIGHT ACCUMULATIONS. OVERALL...NOT ENOUGH TO WARRANT AN
ADVISORY...BUT WILL ISSUE AN SPS.
CLEARING WILL TAKE PLACE WEST TO EAST THIS AFTERNOON AND EVENING.
CLEAR SKIES AND LIGHT WINDS...WITH LOW LEVEL RIDGE AXIS OVER THE
CWA...WILL LEAD TO A COLD NIGHT. LOWS WEDNESDAY MORNING DIP INTO
THE MID AND UPPER 20S ACROSS THE HILL COUNTRY AND LOW TO MID 30S
ELSEWHERE. HIGHS REBOUND INTO THE MID 60S UNDER SUNNY SKIES
WEDNESDAY.
JR
&&
.LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...A WARMING TREND WILL
OCCUR THURSDAY THROUGH SATURDAY ACROSS THE CWA...WITH TEMPERATURES
BACK ABOVE NORMAL FRIDAY AND SATURDAY. LOW LEVEL RETURN FLOW WILL
DEVELOP OVER THE AREA ON THURSDAY...WITH A RETURN OF CLOUDS
THURSDAY NIGHT. PATCHY DRIZZLE AND ISOLATED SHOWERS POSSIBLE
MAINLY ALONG AND EAST OF I-35 FRIDAY AND SATURDAY. ECMWF AND GFS
IN GENERAL AGREEMENT WITH THE NEXT COLD FRONT MOVING THROUGH
SOUTH-CENTRAL TEXAS SUNDAY MORNING. ISENTROPIC UPGLIDE PATTERN
DEVELOPS OVER THE SHALLOW...COLD AIRMASS LEADING TO CLOUDY AND MUCH
COLDER CONDITIONS SUNDAY AND MONDAY ALONG WITH CHANCES FOR RAIN.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 51 35 65 40 71 / 20 0 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 49 29 64 35 69 / 20 0 0 0 0
NEW BRAUNFELS MUNI AIRPORT 50 32 66 38 72 / 20 0 0 0 0
BURNET MUNI AIRPORT 49 32 62 37 68 / 20 0 0 0 0
DEL RIO INTL AIRPORT 53 35 67 43 72 / 20 0 0 0 0
GEORGETOWN MUNI AIRPORT 51 31 64 37 68 / 20 0 0 0 0
HONDO MUNI AIRPORT 53 30 65 37 73 / 30 0 0 0 0
SAN MARCOS MUNI AIRPORT 51 31 65 37 71 / 20 0 0 0 0
LA GRANGE - FAYETTE REGIONAL 51 33 65 38 71 / 20 0 0 0 0
SAN ANTONIO INTL AIRPORT 52 33 65 40 71 / 30 0 0 0 0
STINSON MUNI AIRPORT 53 33 65 39 72 / 30 0 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...18
SYNOPTIC/GRIDS...76
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
327 AM CST TUE FEB 17 2015
.DISCUSSION...
RAIN FROM EARLIER THIS MORNING HAS PUSHED OFF THE COAST LEAVING
CLOUDY AND COLD CONDITIONS IN ITS WAKE. THERE IS CURRENTLY SOME
VERY LIGHT SNOW BEING REPORTED IN THE TEXAS HILL COUNTRY THAT IS
SLOWLY FALLING APART AS IT PUSHES TO THE EAST. THE HRRR HAS BEEN
THE MODEL OF CHOICE THIS MORNING AND HAS SOME VERY LIGHT
REFLECTIVITY MAKING IT INTO THE AREA JUST AFTER SUNRISE THIS
MORNING. ANY PRECIP WILL BE FIGHTING VERY DRY AIR THOUGH BETWEEN
700 AND 850 MB. IF SOME PRECIP DOES REACH THE GROUND IT WILL
PROBABLY HIT THE GROUND AS SLEET. WE WILL CONTINUE TO WATCH THE
LIGHT PRECIP OUT WEST AND MAKE ADJUSTMENTS TO THE FORECAST AS
NEEDED.
AFTER THE PRECIP EXITS THE AREA THIS MORNING SKIES WILL BEGIN TO
GRADUALLY CLEAR FROM WEST TO EAST THIS AFTERNOON AS DRIER AIR
WORKS IN FROM THE NORTH. WEDNESDAY MORNING STILL LOOKS COLD AS
SURFACE HIGH PRESSURE MOVES OVERHEAD. DURING THE DAY WEDNESDAY THE
WARMING TREND WILL START AS SURFACE HIGH PRESSURE BEGINS TO PUSH
EAST. THE CHANCE OF RAIN THEN RETURNS TO THE FORECAST STARTING
FRIDAY AFTERNOON AHEAD OF THE NEXT UPPER LEVEL SYSTEM DIVING SOUTH
OVER THE WEST COAST. MODELS HAVE STRUGGLED WITH THIS DISTURBANCE
THE LAST COUPLE OF DAYS BUT SEEM TO BE CONVERGING ON A SOLUTION.
THE GFS... ECMWF... AND CMC ALL DIVE THE ENERGY SOUTHWARDS AND
FORM A CUT OFF LOW NEAR THE NEVADA/ CALIFORNIA BORDER. STILL
THERE REMAINS DIFFERENCES IN THE COLD FRONT TIMING FOR SUNDAY WITH
THE EURO BEING THE FASTEST AND THE GFS BEING SLIGHT SLOWER. FOR
NOW HAVE TRENDED TOWARDS THE EURO WHICH BRINGS THE FRONT THROUGH
SUNDAY MORNING. ISENTROPIC UPGLIDE THEN LOOKS TO COMMENCE ALLOWING
THE CHANCE OF RAIN TO REMAIN IN THE FORECAST THROUGH THE BEGINNING
OF THE NEXT WORK WEEK. 23
&&
.MARINE...
STRONG COLD FRONT HAS PUSHED INTO THE GULF WITH STRONG NORTHERLY
WINDS BEHIND IT THIS MORNING. WINDS SHOULD BE DECREASING THROUGH THE
MORNING AND WILL KEEP A SCA FOR THE OFFSHORE WATERS OF THE UPPER TX
COAST. SCEC WILL BE IN EFFECT FOR THE NEAR SHORE WATERS AND BAYS.
HIGH PRESSURE BUILDS OVER THE REGION TONIGHT INTO WED ALLOWING FOR
LIGHT WINDS AND LOW SEAS.
MODELS STILL SHOW STRONG SE WINDS DEVELOPING THUR AND PERSISTING
THROUGH SATURDAY. LONG SOUTHERLY FETCH SHOULD BUILD SEAS TO NEAR 6FT
NEAR SHORE AND 9-10FT OFFSHORE SO SCA WILL BE LIKELY. COLD FRONT
SHOULD PUSH OFF THE COAST DURING THE DAY SUNDAY AND TURN WINDS TO
THE N/NE. SCA WILL LIKELY BE NEEDED AGAIN BUT FOR OFFSHORE WINDS.
ECMWF SHOWING THE FRONT COULD PUSH THROUGH SUN MORNING INSTEAD OF
LATER IN THE DAY. FORECAST WAS TRENDED IN THIS DIRECTION.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 48 35 63 38 64 / 20 0 0 0 0
HOUSTON (IAH) 49 34 64 38 64 / 20 0 0 0 0
GALVESTON (GLS) 49 42 61 47 62 / 20 0 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 9 AM CST THIS MORNING
FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20
NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 9 AM CST THIS MORNING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...23
AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
320 AM CST TUE FEB 17 2015
.SHORT TERM...
UPPER LEVEL IMPULSE TRANSLATING THROUGH THE AREA THIS MORNING RIGHT
ON SCHEDULE...AND DIRECTED MORE TOWARDS SOUTHERN ZONES WITH LIFT AND
SLIGHTLY DEEPER MOISTURE. THE MID LEVEL LIFT OVERNIGHT SO FAR HAS
SUCCEEDED IN MODEST TOP-DOWN MOISTENING AND SURFACE DEW-POINTS LATELY
HAVE RISEN OVER SOUTHERN ZONES AT LEAST TO THE POINT WHERE LIGHT
SNOW OR SNOW SHOWERS COULD REACH THE GROUND OVER A LARGER AREA. WITH
THAT...HOWEVER...THE RECENT RAP TRENDS SUPPORT ONLY A BRIEF
OPPORTUNITY FOR MOSTLY INSIGNIFICANT ACCUMULATIONS ACROSS MAINLY THE
SOUTHWESTERN SOUTH PLAINS OVER THE NEXT SEVERAL HOURS. THE
PREVIOUSLY ISSUED WINTER WEATHER ADVISORY IN THE SOUTHWESTERN SOUTH
PLAINS STILL SEEMS MORE THAN ADEQUATE BARRING UNEXPECTED LIFT
FURTHER NORTH OR EAST AND LIKELY WILL EXPIRE AT 12Z IF NOT EARLIER.
REMAINING LIGHT SNOW OR SNOW SHOWERS SHOULD FADE AROUND MID MORNING.
IN SPITE OF DRYING TRENDS ON BACK SIDE OF THIS WAVE...SHORT TERM
WRF/NAM CONTINUES TO INDICATE A WEAK CONVECTIVE SIGNAL AROUND MID
DAY INTO AT LEAST EARLY AFTERNOON AND WE HAVE RETAINED LIGHT RAIN
SHOWER POSSIBILITY THIS AREA. FURTHER DRYING AND CLEARING WILL OCCUR
LATER TODAY AND OVERNIGHT. MINOR CHANGES REMAINDER OF FORECAST.
RMCQUEEN
.LONG TERM...
MEDIUM RANGE MODELS ARE BEGINNING TO SHOW A GLIMMER OF HOPE DEPICTING
A LITTLE MORE CONSISTENCY FOR THIS WEEKEND INTO EARLY NEXT WEEK.
BEFORE THEN...SURFACE LEE TROUGHING WILL RETURN ON THURSDAY AND
FRIDAY BUMPING TEMPERATURES BACK WELL ABOVE SEASONAL AVERAGES AS
PREVIOUSLY SEEN THIS WINTER SEASON ON THESE TYPES OF DAYS. A STRONG
COLD FRONT WILL MAKE ITS WAY INTO THE AREA ON SATURDAY AHEAD OF A
SURFACE RIDGE SPILLING INTO THE PLAINS AND MIDWEST YET AGAIN. MODELS
SHOW COLD 850MB TEMPERATURES BETWEEN -6 AND -9C BY MONDAY MORNING.
BOTH THE GFS AND ECMWF HAVE BEEN SHOWING VERY LIGHT QPF AMOUNTS ON
SUNDAY AND MONDAY NEXT WEEK. MOST OF THIS ACTIVITY IS DICTATED BY
ISENTROPIC LIFT WITH NEARLY ZONAL FLOW ALOFT. THESE TYPES OF
PATTERNS WHICH ARE DOMINATED BY UPGLIDE TEND TO BE VERY LIGHT IN
PRECIPITATION AMOUNTS AND ARE USUALLY DEFINED BY DRIZZLE. WITH THE
COLD AIR IN PLACE WE COULD SEE A WINTRY MIX OF FZRA/FZDZ EARLY NEXT
WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 44 22 55 29 / 20 0 0 0
TULIA 45 24 55 29 / 20 0 0 0
PLAINVIEW 47 25 56 30 / 20 0 0 0
LEVELLAND 47 26 61 31 / 30 0 0 0
LUBBOCK 48 26 60 31 / 20 0 0 0
DENVER CITY 47 27 62 31 / 30 0 0 0
BROWNFIELD 46 26 61 32 / 30 0 0 0
CHILDRESS 53 25 56 29 / 20 0 0 0
SPUR 50 28 60 32 / 20 0 0 0
ASPERMONT 52 28 62 33 / 20 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
TXZ039-040.
&&
$$
05/01
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1137 PM CST MON FEB 16 2015
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...MVFR CIGS TO PREVAIL TONIGHT AS A SHARP SURFACE
INVERSION HAS BECOME ESTABLISHED IN WAKE OF THE FRONT. A WEAK
BUT PERSISTENT OVERRUNNING PATTERN WILL KEEP CIGS BETWEEN
1000-2500 FEET THROUGH TUESDAY MORNING. DRIER AIR EVENTUALLY
WORKS ITS WAY INTO THE VALLEY AS HIGH PRESSURE MOVES SOUTH
WEAKENING THE INVERSION AND ALLOWING FOR THE LOWER CLOUDS TO
BREAK AND RISE. IMPROVING FLYING CONDITIONS ARE ANTICIPATED
ESPECIALLY AFTER 3 PM. NORTH WINDS GUSTS AROUND 20 KTS TONIGHT
AND TUESDAY MORNING BEFORE BECOMING LESS FREQUENT.
&&
.PREV DISCUSSION... /ISSUED 1029 PM CST MON FEB 16 2015/
DISCUSSION...A FEW MINOR TWEAKS TO THE POP FORECAST OVERNIGHT.
SHALLOW MOISTURE AND WEAK OVERRUNNING WITH MINOR DISTURBANCES IN
THE MID LEVEL SOUTHWEST FLOW TO LIMIT RAINFALL OVERNIGHT. ECHOS
OUT WEST TO PRODUCE A FEW SPRINKLES WITH NOT MUCH FANFARE. BEST
POPS HAVE BEEN SHIFTED OUT WEST WITH SLIGHT CHANCES ELSEWHERE.
TEMPERATURES ARE IN THE BALL PARK AND WINDS CONTINUE TO STEADILY
DIMINISH.
PREV DISCUSSION... /ISSUED 545 PM CST MON FEB 16 2015/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...THE COLD FRONT HAS PASSED THROUGH ALL TERMINALS AND
IS TRACKING SOUTH OF THE RIO GRANDE RIVER. IFR TO LOWER END MVFR
CEILING HAVE QUICKLY FILLED IN WAKE OF THE FRONT WITH NORTH WINDS
GUSTING 25 TO 30 KNOTS THROUGH AT LEAST 8 PM. THE HIGHER GUST TO
BECOME LESS FREQUENT WITH TIME WITH A STEADY NORTH WIND THE REST
OF THE NIGHT. CEILINGS TO RISE SLIGHTLY BUT REMAIN MAINLY ON THE
LOWER END OF MVFR UNTIL SUNRISE OR BY MID MORNING TUESDAY WHEN
THE MIGHT APPROACH VFR.
PREV DISCUSSION... /ISSUED 316 PM CST MON FEB 16 2015/
SHORT TERM /NOW THROUGH TUESDAY NIGHT/...A STRONG COLD FRONT
EXTENDING CURRENTLY FROM NEAR RIO GRANDE CITY TO NEAR BAFFIN BAY
WITH A PRE FRONTAL TROUGH AHEAD OF THE FRONT...ACROSS THE UPPER
PORTIONS OF THE RIO GRANDE VALLEY. WEST TO SOUTHWEST WINDS BETWEEN
2 TO 4K FEET MIXING DOWN TO THE SURFACE ALONG WITH FULL SUNSHINE HAS
ALLOWED TEMPERATURES TO SPIKE INTO THE LOW TO MID 80S ACROSS THE
VALLEY. BASED ON THE LATEST NAM/RAP AND HRRR DATA...THE STRONG FRONT
IS EXPECTED TO MOVE THROUGH MCALLEN AND HARLINGEN BETWEEN 4 AND 5
PM...BROWNSVILLE BETWEEN 5 AND 6 PM AND OFF THE LOWER TEXAS COAST
AROUND 7 PM. A DRASTIC CHANGE TO TEMPERATURES...BREEZY NORTH
WINDS...INCREASING LOW CLOUDINESS AND A POSSIBLE LIGHT SHOWER WILL
ACCOMPANY THE SHARP FROPA. TEMPERATURES WILL CONTINUE TO DROP
THROUGH THE EVENING WITH OVERNIGHT LOW TEMPERATURES IN THE 40S UNDER
MOSTLY CLOUDY SKIES. A MID TO UPPER LEVEL DISTURBANCE WILL MOVE
OVERHEAD TONIGHT. THIS FEATURE WILL SUPPORT ISOLATED TO SCATTERED
SHOWERS ACROSS THE REGION TONIGHT AND MAY LINGER ALONG THE COAST
INTO THE GULF WATERS TUESDAY MORNING.
SURFACE HIGH PRESSURE WILL BUILD ACROSS DEEP SOUTH TEXAS ON TUESDAY.
SKIES WILL GRADUALLY CLEAR BY TUESDAY AFTERNOON WITH TEMPERATURES
REMAINING WELL BELOW NORMAL. HIGH TEMPERATURES ON TUESDAY WILL BE IN
THE MID TO UPPER 50S WITH A FEW 60S POSSIBLE ACROSS THE WESTERN AREA
WITH MODERATE NORTH TO NORTHEAST WINDS. SURFACE HIGH PRESSURE
SETTLES ACROSS THE AREA TUESDAY NIGHT. CLEAR SKIES...DRY AIR AND
LIGHT WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING TUESDAY NIGHT.
OVERNIGHT LOW TEMPERATURES TUESDAY NIGHT EXPECTED TO FALL INTO THE
UPPER 30S ACROSS THE NORTHERN RANCHLANDS...LOWER 40S ACROSS THE RIO
GRANDE VALLEY AND THE MID 40S ALONG THE BEACHES.
LONG TERM /WEDNESDAY THROUGH MONDAY/...500 MB RIDGING WILL
BUILD OVER DEEP SOUTH TX STARTING WEDNESDAY CONTINUING INTO FRIDAY
WHICH WILL ALLOW THE 1000-500 MB THICKNESSES TO INCREASE WITH A
PERSISTENT S-SE SURFACE FLOW BRINGING IN STEADY WAA AT THE LOW
LEVELS. THIS WILL ALLOW TEMPS TO STEADILY INCREASE THROUGH THE END
OF THIS WEEK. AS THE WEEKEND APPROACHES THE 500 MB RIDGE WILL BE
ERODED STEADILY AS A SERIES OF STRONG SHORT WAVES CARVE OUT A
BROAD 500 MB TROUGH OVER THE NORTHERN HALF OF THE LOWER 48 STATES.
AS THIS 500 MB TROFFING DEEPENS A COLD FRONT WILL BE PUSHED
TOWARDS DEEP SOUTH TX ON SUN.
THE ECMWF AND GFS ARE IN GOOD AGREEMENT IN THE OVERALL PLACEMENT
OF THE 500 MB FEATURES THROUGH FRI. THE MODELS THEN START TO
DIVERGE STEADILY FROM SAT THROUGH MON WITH THE ECMWF DIGGING A
DEEPER 500 MB TROUGH AXIS OVER THE LOWER 48 STATES VERSUS THE GFS.
THE GFS KEEPS THE 500 MB TROUGH AXIS MORE ELONGATED FROM THE WEST
COAST UP THROUGH THE GREAT LAKES WHICH KEEPS THE COLD FRONT FROM
PUSHING THROUGH THE RGV.
MOISTURE ADVECTION AHEAD OF THIS NEXT POTENTIAL FROPA IS NOT THE
GREATEST IN THE WORLD SO WILL HOLD THE POPS AROUND 20 % LATE IN
THE FORECAST PERIOD UNTIL THE MODELS RESOLVE THEMSELVES A BIT
BETTER.
WILL LEAN MORE TOWARDS THE ECMWF SOLUTION THROUGH DAY 7 FOR TEMPS.
OVERALL CONFIDENCE IN THE FORECAST IS PRETTY GOOD THROUGH FRI THEN
STARTS TO DROP FOR THE SAT THROUGH MON PERIOD DUE TO THE ECMWF AND
GFS DIVERGENCE LATE IN THE PERIOD.
MARINE...NOW THROUGH TUESDAY NIGHT...LIGHT SOUTH TO SOUTHWEST WINDS
WILL CONTINUE ALONG THE LOWER TEXAS COASTAL FOR THE NEXT FEW HOURS.
A STRONG COLD FRONT WILL MOVE FROM NORTH TO SOUTH ACROSS THE MARINE
AREA. WINDS WILL QUICKLY SHIFT TO THE NORTH TO NORTHWEST WITH GUSTY
WINDS. A SMALL CRAFT ADVISORY IS IN EFFECT FOR ALL OF THE LOWER
TEXAS COASTAL WINDS DUE TO VERY STRONG WINDS WITH ROUGH SEAS ON THE
GULF. MARINE CONDITIONS GRADUALLY IMPROVE TUESDAY EVENING INTO
WEDNESDAY AS HIGH PRESSURE SETTLES ACROSS THE AREA.
WEDNESDAY THROUGH SATURDAY...A MODERATE TO STRONG S-SE WINDS WILL
PREVAIL IN THE LONGER RANGE MARINE FORECAST PERIOD AS BROAD
SURFACE RIDGING REMAINS IN PLACE OVER THE GULF OF MEX. THE PGF
TIGHTENS UP ENOUGH FROM LATE THURS THROUGH SATURDAY TO POSSIBLY
RESULT IN SOME SCA FOR THE GULF WATERS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 3 AM CST TUESDAY FOR GMZ130-
132-135.
SMALL CRAFT ADVISORY UNTIL 6 PM CST TUESDAY FOR GMZ150-155-170-
175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
67/61
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1029 PM CST MON FEB 16 2015
.DISCUSSION...A FEW MINOR TWEAKS TO THE POP FORECAST OVERNIGHT.
SHALLOW MOISTURE AND WEAK OVERRUNNING WITH MINOR DISTURBANCES IN
THE MID LEVEL SOUTHWEST FLOW TO LIMIT RAINFALL OVERNIGHT. ECHOS
OUT WEST TO PRODUCE A FEW SPRINKLES WITH NOT MUCH FANFARE. BEST
POPS HAVE BEEN SHIFTED OUT WEST WITH SLIGHT CHANCES ELSEWHERE.
TEMPERATURES ARE IN THE BALL PARK AND WINDS CONTINUE TO STEADILY
DIMINISH.
&&
.PREV DISCUSSION... /ISSUED 545 PM CST MON FEB 16 2015/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...THE COLD FRONT HAS PASSED THROUGH ALL TERMINALS AND
IS TRACKING SOUTH OF THE RIO GRANDE RIVER. IFR TO LOWER END MVFR
CEILING HAVE QUICKLY FILLED IN WAKE OF THE FRONT WITH NORTH WINDS
GUSTING 25 TO 30 KNOTS THROUGH AT LEAST 8 PM. THE HIGHER GUST TO
BECOME LESS FREQUENT WITH TIME WITH A STEADY NORTH WIND THE REST
OF THE NIGHT. CEILINGS TO RISE SLIGHTLY BUT REMAIN MAINLY ON THE
LOWER END OF MVFR UNTIL SUNRISE OR BY MID MORNING TUESDAY WHEN
THE MIGHT APPROACH VFR.
PREV DISCUSSION... /ISSUED 316 PM CST MON FEB 16 2015/
SHORT TERM /NOW THROUGH TUESDAY NIGHT/...A STRONG COLD FRONT
EXTENDING CURRENTLY FROM NEAR RIO GRANDE CITY TO NEAR BAFFIN BAY
WITH A PRE FRONTAL TROUGH AHEAD OF THE FRONT...ACROSS THE UPPER
PORTIONS OF THE RIO GRANDE VALLEY. WEST TO SOUTHWEST WINDS BETWEEN
2 TO 4K FEET MIXING DOWN TO THE SURFACE ALONG WITH FULL SUNSHINE HAS
ALLOWED TEMPERATURES TO SPIKE INTO THE LOW TO MID 80S ACROSS THE
VALLEY. BASED ON THE LATEST NAM/RAP AND HRRR DATA...THE STRONG FRONT
IS EXPECTED TO MOVE THROUGH MCALLEN AND HARLINGEN BETWEEN 4 AND 5
PM...BROWNSVILLE BETWEEN 5 AND 6 PM AND OFF THE LOWER TEXAS COAST
AROUND 7 PM. A DRASTIC CHANGE TO TEMPERATURES...BREEZY NORTH
WINDS...INCREASING LOW CLOUDINESS AND A POSSIBLE LIGHT SHOWER WILL
ACCOMPANY THE SHARP FROPA. TEMPERATURES WILL CONTINUE TO DROP
THROUGH THE EVENING WITH OVERNIGHT LOW TEMPERATURES IN THE 40S UNDER
MOSTLY CLOUDY SKIES. A MID TO UPPER LEVEL DISTURBANCE WILL MOVE
OVERHEAD TONIGHT. THIS FEATURE WILL SUPPORT ISOLATED TO SCATTERED
SHOWERS ACROSS THE REGION TONIGHT AND MAY LINGER ALONG THE COAST
INTO THE GULF WATERS TUESDAY MORNING.
SURFACE HIGH PRESSURE WILL BUILD ACROSS DEEP SOUTH TEXAS ON TUESDAY.
SKIES WILL GRADUALLY CLEAR BY TUESDAY AFTERNOON WITH TEMPERATURES
REMAINING WELL BELOW NORMAL. HIGH TEMPERATURES ON TUESDAY WILL BE IN
THE MID TO UPPER 50S WITH A FEW 60S POSSIBLE ACROSS THE WESTERN AREA
WITH MODERATE NORTH TO NORTHEAST WINDS. SURFACE HIGH PRESSURE
SETTLES ACROSS THE AREA TUESDAY NIGHT. CLEAR SKIES...DRY AIR AND
LIGHT WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING TUESDAY NIGHT.
OVERNIGHT LOW TEMPERATURES TUESDAY NIGHT EXPECTED TO FALL INTO THE
UPPER 30S ACROSS THE NORTHERN RANCHLANDS...LOWER 40S ACROSS THE RIO
GRANDE VALLEY AND THE MID 40S ALONG THE BEACHES.
LONG TERM /WEDNESDAY THROUGH MONDAY/...500 MB RIDGING WILL
BUILD OVER DEEP SOUTH TX STARTING WEDNESDAY CONTINUING INTO FRIDAY
WHICH WILL ALLOW THE 1000-500 MB THICKNESSES TO INCREASE WITH A
PERSISTENT S-SE SURFACE FLOW BRINGING IN STEADY WAA AT THE LOW
LEVELS. THIS WILL ALLOW TEMPS TO STEADILY INCREASE THROUGH THE END
OF THIS WEEK. AS THE WEEKEND APPROACHES THE 500 MB RIDGE WILL BE
ERODED STEADILY AS A SERIES OF STRONG SHORT WAVES CARVE OUT A
BROAD 500 MB TROUGH OVER THE NORTHERN HALF OF THE LOWER 48 STATES.
AS THIS 500 MB TROFFING DEEPENS A COLD FRONT WILL BE PUSHED
TOWARDS DEEP SOUTH TX ON SUN.
THE ECMWF AND GFS ARE IN GOOD AGREEMENT IN THE OVERALL PLACEMENT
OF THE 500 MB FEATURES THROUGH FRI. THE MODELS THEN START TO
DIVERGE STEADILY FROM SAT THROUGH MON WITH THE ECMWF DIGGING A
DEEPER 500 MB TROUGH AXIS OVER THE LOWER 48 STATES VERSUS THE GFS.
THE GFS KEEPS THE 500 MB TROUGH AXIS MORE ELONGATED FROM THE WEST
COAST UP THROUGH THE GREAT LAKES WHICH KEEPS THE COLD FRONT FROM
PUSHING THROUGH THE RGV.
MOISTURE ADVECTION AHEAD OF THIS NEXT POTENTIAL FROPA IS NOT THE
GREATEST IN THE WORLD SO WILL HOLD THE POPS AROUND 20 % LATE IN
THE FORECAST PERIOD UNTIL THE MODELS RESOLVE THEMSELVES A BIT
BETTER.
WILL LEAN MORE TOWARDS THE ECMWF SOLUTION THROUGH DAY 7 FOR TEMPS.
OVERALL CONFIDENCE IN THE FORECAST IS PRETTY GOOD THROUGH FRI THEN
STARTS TO DROP FOR THE SAT THROUGH MON PERIOD DUE TO THE ECMWF AND
GFS DIVERGENCE LATE IN THE PERIOD.
MARINE...NOW THROUGH TUESDAY NIGHT...LIGHT SOUTH TO SOUTHWEST WINDS
WILL CONTINUE ALONG THE LOWER TEXAS COASTAL FOR THE NEXT FEW HOURS.
A STRONG COLD FRONT WILL MOVE FROM NORTH TO SOUTH ACROSS THE MARINE
AREA. WINDS WILL QUICKLY SHIFT TO THE NORTH TO NORTHWEST WITH GUSTY
WINDS. A SMALL CRAFT ADVISORY IS IN EFFECT FOR ALL OF THE LOWER
TEXAS COASTAL WINDS DUE TO VERY STRONG WINDS WITH ROUGH SEAS ON THE
GULF. MARINE CONDITIONS GRADUALLY IMPROVE TUESDAY EVENING INTO
WEDNESDAY AS HIGH PRESSURE SETTLES ACROSS THE AREA.
WEDNESDAY THROUGH SATURDAY...A MODERATE TO STRONG S-SE WINDS WILL
PREVAIL IN THE LONGER RANGE MARINE FORECAST PERIOD AS BROAD
SURFACE RIDGING REMAINS IN PLACE OVER THE GULF OF MEX. THE PGF
TIGHTENS UP ENOUGH FROM LATE THURS THROUGH SATURDAY TO POSSIBLY
RESULT IN SOME SCA FOR THE GULF WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 48 56 45 66 / 20 20 0 0
BROWNSVILLE 47 57 44 67 / 20 20 0 0
HARLINGEN 46 57 42 67 / 20 20 0 0
MCALLEN 47 60 42 68 / 20 10 0 0
RIO GRANDE CITY 47 60 41 69 / 30 10 0 0
SOUTH PADRE ISLAND 51 56 52 64 / 20 30 0 0
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 3 AM CST TUESDAY FOR GMZ130-
132-135.
SMALL CRAFT ADVISORY UNTIL 6 PM CST TUESDAY FOR GMZ150-155-170-
175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
59/68
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1249 AM EST TUE FEB 17 2015
.SYNOPSIS...
A WINTER STORM WILL MOVE ACROSS THE MID-ATLANTIC REGION TONIGHT.
THIS STORM WILL PRODUCE HEAVY SNOW ACROSS THE VIRGINIA`S AND A
MIXTURE OF SNOW...SLEET...AND FREEZING RAIN ACROSS THE CAROLINAS.
THE STORM WILL MOVE EAST AND OFF THE COAST TUESDAY...FOLLOWED BY
THE PASSAGE OF AN ARCTIC COLD FRONT ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS 1145 PM EST MONDAY...
MAIN SHORT WAVE AND UPPER JET SUPPORT WERE CROSSING THROUGH
SOUTHERN VIRGINIA AT 11PM. WESTERN EDGE OF THE MODERATE TO HEAVY
SNOW WAS ADVANCING EAST THROUGH THE FORECAST AREA. EXPECT THIS TO
CLEAR THE SOUTHEAST COUNTIES AROUND MIDNIGHT. LIGHT SNOW WILL END
FROM WEST TO EAST BETWEEN 08Z/3AM AND 12Z/7AM BASED ON LOCAL WRF
AND HRRR GUIDANCE.
00Z SOUNDING AT RNK HAD WARM NOSE OF -1.1C WHILE GSO SOUNDING
SHOWED A WARM NOSE AT 0C. GETTING NUMEROUS REPORTS OF SLEET FROM
WILKES COUNTY ACROSS THE NORTH CAROLINA FOOTHILLS AND PIEDMONT.
WITH THE BULK OF THE MODERATE TO HEAVY SNOW NOW MOVING
OUT...REMAINING SNOW ACCUMULATIONS THROUGH 12Z/7AM WILL BE IN THE
1 TO 3 INCH RANGE.
NO CHANGES ARE PLANNED TO THE WINTER STORM WARNINGS AT THIS TIME.
MODELS ARE IN VERY GOOD AGREEMENT WITH THE FORECAST TRACK OF THIS
STORM AND THE PLACEMENT OF THE HEAVIEST SNOW. SEE NO REASON STRAY
FROM GUIDANCE.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
AS OF 400 AM EST MONDAY...
WILL START TUESDAY NIGHT OFF WITH WINDS SHIFTING MORE SOUTHWESTERLY
AHEAD OF OUR NEXT ARCTIC COLD FRONT. OVERNIGHT LOW TEMPERATURES WILL
RANGE FROM THE LOW TEENS ACROSS THE MOUNTAINS...TO THE MID AND UPPER
TEENS ACROSS THE PIEDMONT. WIND SPEEDS WILL INCREASE TOWARD DAWN AS
THE PRESSURE GRADIENT TIGHTENS...WHICH WILL PUSH WIND CHILL
TEMPERATURES INTO THE LOW SINGLE DIGITS ACROSS THE MOUNTAINS...AND
BELOW ZERO IN A FEW SPOTS.
THE ARCTIC COLD FRONT WILL ARRIVE DURING LATE WEDNESDAY MORNING...
RESULTING IN ANOTHER RAPID DROP IN TEMPERATURES AND AN INCREASE IN
WIND SPEEDS...ALTHOUGH NOT A STRONG AS THOSE OBSERVED THIS PAST
WEEKEND. THAT STATED...WOULD NOT BE SURPRISED TO SEE 50 MPH GUSTS
ACROSS THE HIGHER RIDGES WEDNESDAY EVENING AND WEDNESDAY NIGHT. THE
FRONT WILL ALSO BRING WITH IT ANOTHER ROUND OF SNOW SHOWERS THAT
WILL AFFECT THE ENTIRE FORECAST REGION TO SOME DEGREE. ONE TO THREE
INCHES OF ADDITIONAL SNOWFALL CAN BE EXPECTED ALONG THE WEST FACING
SLOPES...WITH LOCALLY HIGHER AMOUNTS...WHILE A QUARTER TO HALF INCH
OF ADDITIONAL SNOW CAN BE EXPECTED FOR THE FOOTHILLS AND THE
PIEDMONT. THE VERY COLD AIR BUILDING IN BEHIND THE FRONT WILL ENSURE
A DRY POWDERY SNOW...WHICH WILL BLOW EASILY IN THE GUSTY WINDS. AS
SUCH...HAZARDOUS TRAVEL CONDITIONS CAN BE EXPECTED DUE TO DRIFTING
OF SNOW ON ROADWAYS AND OCCASIONAL WHITE OUT CONDITIONS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 400 PM EST MONDAY...
WILL BE UPDATED BY 600 PM.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 1245 AM EST TUESDAY...
HIGH CONFIDENCE FORECAST AS WINTER STORM WILL CONTINUE POOR
FLYING CONDITIONS WITH SNOW. MODERATE TO HEAVY SNOW HAS MOVED OUT
OF REGION. RADAR AND OBSERVATIONS AT 05Z INDICATED MVFR CEILINGS
AND A MIX OF LIGHT SNOW...SLEET AND FREEZING DRIZZLE AS FAR NORTH
AS KBCB...KROA AND KLYH. ANY ADDITIONAL SNOW AND SLEET
ACCUMULATION WILL BE ONE OR TWO INCHES. A LIGHT GLAZE OF ICE IS
POSSIBLE ON TOP OF THE SNOW AND SLEET.
THE PRECIPITATION WILL TAPER OFF FROM WEST TO EAT BETWEEN 09Z/4AM
AND 12Z/7AM. HOWEVER...CEILINGS WILL LOWER BACK TO IFR OR LIFR.
ONCE THE SURFACE LOW MOVES OFF THE VIRGINIA COAST...WINDS WILL
COME AROUND TO THE NORTHWEST. CEILINGS WILL BEGIN TO LIFT EAST OF
THE BLUE RIDGE BY LATE AFTERNOON. MODERATE CONFIDENCE THAT
KROA/KDAN AND KLYH WILL IMPROVE TO VFR BY 00Z/7PM TUESDAY.
AN ARCTIC COLD FRONT COMES THROUGH WEDNESDAY WITH STRONG
NORTHWEST WINDS WEDNESDAY INTO THURSDAY. MOUNTAIN SNOW SHOWERS
WITH MVFR CEILINGS AND VISIBILITIES ARE LIKELY WEDNESDAY AND
WEDNESDAYS NIGHT AND WILL BEGIN TO DISSIPATE ON THURSDAY. WITH
STRONG DOWNSLOPE WINDS...CONDITIONS FARTHER EAST OF THE BLUE
RIDGE WILL BE VFR.
THE NEXT VFR DAY IN THE MOUNTAINS WILL NOT BE UNTIL FRIDAY.
ANOTHER FRONT APPROACHES FROM THE WEST ON SATURDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER STORM WARNING UNTIL NOON EST TODAY FOR VAZ007-009>020-
022>024-032>035-043>047-058-059.
NC...WINTER STORM WARNING UNTIL NOON EST TODAY FOR NCZ001>006-
018>020.
WV...WINTER STORM WARNING UNTIL NOON EST TODAY FOR WVZ042>044-507-
508.
&&
$$
SYNOPSIS...AMS/PM
NEAR TERM...AMS/PM
SHORT TERM...NF
LONG TERM...NF
AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1152 PM EST MON FEB 16 2015
.SYNOPSIS...
A WINTER STORM WILL MOVE ACROSS THE MID-ATLANTIC REGION TONIGHT.
THIS STORM WILL PRODUCE HEAVY SNOW ACROSS THE VIRGINIA`S AND A
MIXTURE OF SNOW...SLEET...AND FREEZING RAIN ACROSS THE CAROLINAS.
THE STORM WILL MOVE EAST AND OFF THE COAST TUESDAY...FOLLOWED BY
THE PASSAGE OF AN ARCTIC COLD FRONT ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS 1145 PM EST MONDAY...
MAIN SHORT WAVE AND UPPER JET SUPPORT WERE CROSSING THROUGH
SOUTHERN VIRGINIA AT 11PM. WESTERN EDGE OF THE MODERATE TO HEAVY
SNOW WAS ADVANCING EAST THROUGH THE FORECAST AREA. EXPECT THIS TO
CLEAR THE SOUTHEAST COUNTIES AROUND MIDNIGHT. LIGHT SNOW WILL END
FROM WEST TO EAST BETWEEN 08Z/3AM AND 12Z/7AM BASED ON LOCAL WRF
AND HRRR GUIDANCE.
00Z SOUNDING AT RNK HAD WARM NOSE OF -1.1C WHILE GSO SOUNDING
SHOWED A WARM NOSE AT 0C. GETTING NUMEROUS REPORTS OF SLEET FROM
WILKES COUNTY ACROSS THE NORTH CAROLINA FOOTHILLS AND PIEDMONT.
WITH THE BULK OF THE MODERATE TO HEAVY SNOW NOW MOVING
OUT...REMAINING SNOW ACCUMULATIONS THROUGH 12Z/7AM WILL BE IN THE
1 TO 3 INCH RANGE.
NO CHANGES ARE PLANNED TO THE WINTER STORM WARNINGS AT THIS TIME.
MODELS ARE IN VERY GOOD AGREEMENT WITH THE FORECAST TRACK OF THIS
STORM AND THE PLACEMENT OF THE HEAVIEST SNOW. SEE NO REASON STRAY
FROM GUIDANCE.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 400 AM EST MONDAY...
WILL START TUESDAY NIGHT OFF WITH WINDS SHIFTING MORE SOUTHWESTERLY
AHEAD OF OUR NEXT ARCTIC COLD FRONT. OVERNIGHT LOW TEMPERATURES WILL
RANGE FROM THE LOW TEENS ACROSS THE MOUNTAINS...TO THE MID AND UPPER
TEENS ACROSS THE PIEDMONT. WIND SPEEDS WILL INCREASE TOWARD DAWN AS
THE PRESSURE GRADIENT TIGHTENS...WHICH WILL PUSH WIND CHILL
TEMPERATURES INTO THE LOW SINGLE DIGITS ACROSS THE MOUNTAINS...AND
BELOW ZERO IN A FEW SPOTS.
THE ARCTIC COLD FRONT WILL ARRIVE DURING LATE WEDNESDAY MORNING...
RESULTING IN ANOTHER RAPID DROP IN TEMPERATURES AND AN INCREASE IN
WIND SPEEDS...ALTHOUGH NOT A STRONG AS THOSE OBSERVED THIS PAST
WEEKEND. THAT STATED...WOULD NOT BE SURPRISED TO SEE 50 MPH GUSTS
ACROSS THE HIGHER RIDGES WEDNESDAY EVENING AND WEDNESDAY NIGHT. THE
FRONT WILL ALSO BRING WITH IT ANOTHER ROUND OF SNOW SHOWERS THAT
WILL AFFECT THE ENTIRE FORECAST REGION TO SOME DEGREE. ONE TO THREE
INCHES OF ADDITIONAL SNOWFALL CAN BE EXPECTED ALONG THE WEST FACING
SLOPES...WITH LOCALLY HIGHER AMOUNTS...WHILE A QUARTER TO HALF INCH
OF ADDITIONAL SNOW CAN BE EXPECTED FOR THE FOOTHILLS AND THE
PIEDMONT. THE VERY COLD AIR BUILDING IN BEHIND THE FRONT WILL ENSURE
A DRY POWDERY SNOW...WHICH WILL BLOW EASILY IN THE GUSTY WINDS. AS
SUCH...HAZARDOUS TRAVEL CONDITIONS CAN BE EXPECTED DUE TO DRIFTING
OF SNOW ON ROADWAYS AND OCCASIONAL WHITE OUT CONDITIONS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 400 PM EST MONDAY...
WILL BE UPDATED BY 600 PM.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 700 PM EST MONDAY...
HIGH CONFIDENCE FORECAST AS WINTER STORM WILL CONTINUE POOR
FLYING CONDITIONS WITH SNOW. IFR AND LIFR CONDITIONS WITH MODERATE
TO HEAVY SNOW WILL CONTINUE ACROSS THE REGION THROUGH 09Z/4AM. THE
SNOW WILL TAPER OFF FROM WEST TO EAT BETWEEN 09Z/4AM AND 12Z/7AM.
HOWEVER...EVEN THOUGH THE SNOW WILL END CEILINGS WILL REMAIN IFR
OR LIFR. ONCE THE SURFACE LOW MOVES OFF THE VIRGINIA COAST...WINDS
WILL COME AROUND TO THE NORTHWEST AND CEILINGS WILL BEGIN TO LIFT
EAT OF THE BLUE RIDGE. MODERATE CONFIDENCE THAT KROA/KDAN AND KLYH
WILL IMPROVE TO MVFR AFTER 18Z/1PM.
AN ARCTIC COLD FRONT COMES THROUGH TUESDAY NIGHT WITH STRONG
NORTHWEST WIND FOR BOTH WEDNESDAY AND THURSDAY. MOUNTAIN SNOW
SHOWERS AND AT LEAST MVFR CIGS WILL LINGER ACROSS THE MOUNTAINS
THROUGH THURSDAY. THE NEXT COMPLETELY CLEAR VFR WILL NOT BE UNTIL
FRIDAY IN THE MOUNTAINS. ANOTHER FRONTAL SYSTEM APPROACHES FROM
THE WEST SATURDAY INTO SUNDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER STORM WARNING UNTIL NOON EST TUESDAY FOR VAZ007-009>020-
022>024-032>035-043>047-058-059.
NC...WINTER STORM WARNING UNTIL NOON EST TUESDAY FOR NCZ001>006-
018>020.
WV...WINTER STORM WARNING UNTIL NOON EST TUESDAY FOR WVZ042>044-507-
508.
&&
$$
SYNOPSIS...AMS/PM
NEAR TERM...AMS/PM
SHORT TERM...NF
LONG TERM...NF
AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
937 AM EST TUE FEB 17 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE OFFSHORE THIS MORNING AS A STRENGTHENING LOW
PRESSURE SYSTEM SHIFTS OFF THE MID-ATLANTIC COAST. A SERIES OF
REINFORCING COLD FRONTS WILL THEN MOVE THROUGH TONIGHT AND AGAIN
LATE WEDNESDAY. ARCTIC HIGH PRESSURE WILL THEN BUILD INTO THE REGION
AND PERSIST THROUGH FRIDAY. A COASTAL TROUGH WILL DEVELOP ON
SATURDAY...THEN LIFT NORTH ON SUNDAY AHEAD OF AN APPROACHING COLD
FRONT. THE COLD FRONT WILL MOVE THROUGH SUNDAY NIGHT THEN STALL
OFFSHORE AS A WAVE OF LOW PRESSURE TRACKS ALONG IT EARLY NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE COLD FRONT IS ALONG OR JUST OFF THE COAST AT 17/14Z...EXCEPT
ALONG THE UPPER CHARLESTON COUNTY COAST. THE FRONT WILL CLEAR
MCCLELLANVILLE WITHIN THE HOUR.
MOST OF THE SIGNIFICANT RAINS HAVE ENDED. THE ONLY EXCEPTION IS
ALONG THE UPPER GEORGIA COAST WHERE A SECONDARY SURGE OF MOISTURE
IS WORKING ITS WAY IN FROM THE SOUTHWEST. ADJUSTED POPS TO ACCOUNT
OR CURRENT TRENDS. RAINS WILL GRADUALLY END LATER THIS AFTERNOON
ALONG THE GEORGIA COAST...BUT WILL INCREASE AGAIN AS YET ANOTHER
MOISTURE SURGE WORKS ACROSS THE AREA.
MOST AREAS HAVE LIKELY SEEN THEIR DAYTIME HIGH AS TEMPERATURES
ARE FALLING QUICKLY BEHIND THE COLD FRONT. THE DEGREE OF THERMAL
RECOVERY THIS AFTERNOON REMAINS HIGHLY UNCERTAIN WITH SOME
GUIDANCE INDICATING INLAND AREAS COULD REMAIN IN THE 30S WHILE
HOLDING IN THE 40S AT THE COAST. USED A 30/30/30 BLEND OF ENSEMBLE
DATA...H3R AND RAP DATA TO CONSTRUCT HOURLY TEMPERATURES THROUGH
SUNSET. ALSO RECALCULATED HIGH TEMPERATURES BASED ON THIS...BUT
AGAIN...DAILY HIGHS HAVE LIKELY ALREADY OCCURRED IN MOST AREAS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...THE UPPER TROUGH AXIS WILL BE APPROACHING LATE SO THERE
WILL BE SOME PVA AND JET FORCING WHICH WILL MAINTAIN AT LEAST A
SLIGHT CHANCE FOR SHOWERS NEAR THE COAST THROUGH THE EVENING.
TEMPERATURES WILL PLUMMET TOWARD NEAR THE FREEZING MARK LATE BUT
SUFFICIENT MOISTURE SHOULD BE OFFSHORE BY THEN.
WEDNESDAY AND WEDNESDAY NIGHT...A LONG WAVE TROUGH WILL PREVAIL
OVER THE EASTERN UNITED STATES IN THE MID AND UPPER LEVELS OF THE
ATMOSPHERE. AT THE SURFACE...HIGH PRESSURE WILL BUILD INTO THE
REGION FROM THE SOUTHERN PLAINS TO START THE DAY BUT THEN A
REINFORCING COLD FRONT WILL MOVE THROUGH LATE...WITH ARCTIC HIGH
PRESSURE TO FOLLOW THROUGH WEDNESDAY NIGHT.
A DRY WESTERLY FLOW WILL ENSURE THAT NO PRECIPITATION ACCOMPANIES
THE FRONTAL PASSAGE...HOWEVER THERE COULD BE A FEW CLOUDS AROUND
RESULTING IN PARTLY CLOUDY SKIES. A DOWNSLOPE COMPONENT TO THE FLOW
SHOULD ALLOW TEMPERATURES TO WARM TO AROUND 50 OR THE LOWER 50S FOR
HIGHS ACROSS THE AREA. BREEZY CONDITIONS ARE EXPECTED TO DEVELOP IN
THE AFTERNOON AS A LOW LEVEL JET STRENGTHENS AHEAD OF THE COLD
FRONT...WITH GUSTS OF 25-35 MPH...HIGHEST NEAR AND JUST SOUTH OF THE
SAVANNAH RIVER. STRONG COLD AIR ADVECTION IN WAKE OF THE FRONT WILL
PREVENT WINDS FROM DECOUPLING WEDNESDAY NIGHT...AND BREEZY
CONDITIONS ARE EXPECTED TO CONTINUE. IT LOOKS TO BE A COLD NIGHT
WEDNESDAY NIGHT...WITH LOWS IN THE MID 20S ACROSS MUCH OF THE AREA.
THE COMBINATION OF COLD TEMPERATURES AND WIND SHOULD LOWER WIND
CHILL VALUES WELL INTO THE TEENS...THUS WIND CHILL ADVISORIES MAY BE
NEEDED.
THURSDAY AND THURSDAY NIGHT...THE LONG WAVE TROUGH WILL GRADUALLY
SHIFT EASTWARD...WITH THE 500 MB FLOW ALONG THE WESTERN PERIPHERY OF
THE TROUGH FUNNELING IN WHAT WILL LIKELY BE THE COLDEST AIRMASS OF
THE SEASON DIRECT FROM THE ARCTIC. IN FACT...850 MB TEMPERATURES
LOOK TO BE AS COLD AS -10C TO -17C. MEANWHILE...EXPANSIVE HIGH
PRESSURE AT THE SURFACE WILL BUILD IN FROM THE MISSISSIPPI VALLEY.
DESPITE NEARLY FULL SUNSHINE...THICKNESS VALUES ONLY SUPPORT HIGHS
IN THE LOWER TO MID 30S ACROSS MUCH OF THE AREA. HOWEVER...FIGURE A
DOWNSLOPE FLOW MAY OFFSET THAT A BIT SO THE FORECAST WILL INDICATE
HIGHS IN THE MID AND UPPER 30S...EXCEPT AROUND 40 OR IN THE LOWER
40S ALONG AND SOUTH OF I-16. THIS WILL VERY LIKELY RESULT IN RECORD
LOW MAXIMUMS FOR OUR PRIMARY CLIMATE SITES. CONTINUED COLD AIR
ADVECTION THURSDAY NIGHT MAY PREVENT WINDS FROM FULLY
DECOUPLING...WITH LOWS IN THE UPPER TEENS TO LOWER 20S ACROSS THE
AREA. WIND CHILL ADVISORIES LOOK MOST LIKELY LATE THURSDAY NIGHT AS
A RESULT...WITH WIND CHILLS POSSIBLY FALLING AS LOW AS 5F TO 15F
ABOVE ZERO.
FRIDAY...AS THE LONG WAVE TROUGH LIFTS/WEAKENS...HEIGHTS WILL
GRADUALLY RISE ACROSS THE AREA. AT THE SURFACE...HIGH PRESSURE WILL
SHIFT ACROSS THE CENTRAL APPALACHIANS THEN OVER THE SOUTHERN MID-
ATLANTIC AND CAROLINAS. STILL A VERY COLD AIR MASS...WITH HIGHS IN
THE UPPER 30S TO LOWER 40S ACROSS MOST OF THE AREA.
LAKE WINDS...WINDS ON LAKE MOULTRIE COULD REACH LAKE WIND
ADVISORY CRITERIA SOMETIME DURING THE LATE WEDNESDAY THROUGH
THURSDAY NIGHT TIME PERIOD AS STRONG COLD AIR ADVECTION DEVELOPS
OVER THE AREA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
A MORE PROGRESSIVE ZONAL UPPER LEVEL FLOW WILL PREVAIL INTO THE
START OF THE WEEKEND. AS A RESULT...SURFACE HIGH PRESSURE WILL SHIFT
OFF THE MID-ATLANTIC COAST WITH A WEAK COASTAL TROUGH SETTING UP
ALONG THE SOUTHEAST COAST. SOME ENHANCED LOW LEVEL CONVERGENCE COULD
RESULT IN ISOLATED SHOWERS ALONG THE COAST AND INTO THE CHARLESTON
TRI-COUNTY AREA. THE COASTAL TROUGH WILL LIFT NORTHWARD ON
SUNDAY...AS A COLD FRONT APPROACHES FROM THE NORTHWEST. TEMPERATURES
WILL BE ON A WARMING TREND THROUGH THE WEEKEND...ACTUALLY RETURNING
TO ABOVE NORMAL BRIEFLY ON SUNDAY.
THE COLD FRONT SHOULD MOVE THROUGH SUNDAY NIGHT...ACCOMPANIED BY
SHOWERS. THE FRONT THEN APPEARS TO STALL OFF THE SOUTHEAST COAST
INTO EARLY NEXT WEEK...AND EXHIBIT ANAFRONTAL CHARACTERISTICS WITH
PRECIPITATION OCCURRING TO ITS NORTH AND WEST OVER THE AREA. THERE IS
CONCERN THAT COLD AIR FILTERING INTO THE REGION BEHIND THE FRONT
COULD RESULT IN SOME TYPE OF WINTRY PRECIPITATION AND WE WILL NEED
TO MONITOR THIS OVER THE COURSE OF THE WEEK.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
THE STEADY RAIN WILL PUSH OFFSHORE SHORTLY AFTER THE TAF/S
INITIALIZE...BUT SOME LINGERING SHOWERS ARE POSSIBLE THROUGH
MIDDAY SO VICINITY SHOWERS WILL BE MENTIONED IN THE FORECAST.
BEHIND A COLD FRONT PUSHING OFFSHORE BY MID-MORNING...A PERIOD OF
IFR CEILINGS AT KCHS AND LOW-END MVFR CEILINGS AT KSAV ARE
EXPECTED THROUGH ABOUT 18Z. CEILINGS SHOULD THEN REMAIN MVFR AT
BOTH TERMINALS THROUGH LATE AFTERNOON...BEFORE RISING TO VFR FOR
THE REMAINDER OF THE FORECAST PERIOD. GUSTY WINDS ARE POSSIBLE
THROUGH MIDDAY AS WELL.
EXTENDED AVIATION OUTLOOK...GUSTY WINDS WILL OCCUR AT THE TERMINALS
THROUGH THURSDAY. MVFR OR LOWER CEILINGS ARE POSSIBLE FRIDAY NIGHT
INTO SATURDAY AS A COASTAL TROUGH DEVELOPS. OTHERWISE...VFR
CONDITIONS ARE EXPECTED TO PREVAIL.
&&
.MARINE...
TODAY...EXPECT IMPROVING CONDITIONS ALL WATERS TODAY. DROPPED THE
GALE WARNING FOR CHARLESTON COUNTY WATERS BASED ON THE LATEST
PILOT BOAT REPORTS. GALE WARNINGS REMAIN IN EFFECT FOR THE
GEORGIA OFFSHORE WATERS THROUGH EARLY AFTERNOON.
WEDNESDAY THROUGH SUNDAY...CONDITIONS WILL DETERIORATE OVER THE
WATERS LATE WEDNESDAY AS STRONG COLD AIR ADVECTION DEVELOPS IN WAKE
OF A PASSING COLD FRONT...AND GUSTY WINDS WILL CONTINUE THROUGH
THURSDAY NIGHT. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR ALL
WATERS DURING THIS PERIOD...WITH A WINDOW OF GALE FORCE GUSTS
POSSIBLE OVER THE OUTER GEORGIA WATERS MAINLY WEDNESDAY NIGHT. THE
SURFACE PRESSURE GRADIENT WILL RELAX LATE IN THE WEEK INTO THE
WEEKEND AS HIGH PRESSURE PASSES TO THE NORTH AND A COASTAL TROUGH
EVENTUALLY DEVELOPS. A COLD FRONT WILL THEN APPROACH FROM THE
NORTHWEST LATE IN THE WEEKEND...BUT CONDITIONS SHOULD REMAIN BELOW
SMALL CRAFT ADVISORY LEVELS.
&&
.FIRE WEATHER...
RAINFALL EARLY THIS MORNING WILL HELP TO MOISTEN FUELS...BUT AMOUNTS
WILL GENERALLY BE AROUND 1/2 INCH OR LESS. BREEZY CONDITIONS AND A
DRY DOWNSLOPE FLOW WILL ALLOW FUELS TO BEGIN TO DRY OUT WEDNESDAY
AND THERE COULD ONCE AGAIN BE SOME FIRE WEATHER CONCERNS BY THURSDAY
WHEN HUMIDITY FALLS TO 15-25 PERCENT AND WINDS GUST 25-35 MPH.
&&
.TIDES/COASTAL FLOODING...
TIDES COULD APPROACH ADVISORY LEVELS DURING THE EARLY MORNING HIGH
TIDE CYCLE WED...ESPECIALLY ALONG THE SC COAST.
&&
.CLIMATE...
RECORD LOWS FOR FEBRUARY 19...
NORTH CHARLESTON /KCHS/...20 SET IN 1968
DOWNTOWN CHARLESTON /KCXM/...21 SET IN 1979
SAVANNAH /KSAV/...19 SET IN 1958
RECORD LOW MAX TEMPS FOR FEBRUARY 19...
NORTH CHARLESTON /KCHS/...42 SET IN 1972
DOWNTOWN CHARLESTON /KCXM/...42 LAST SET IN 1979
SAVANNAH /KSAV/...40 SET IN 1910
RECORD LOWS FOR FEBRUARY 20...
NORTH CHARLESTON /KCHS/...22 LAST SET IN 1968
DOWNTOWN CHARLESTON /KCXM/...28 SET IN 1958
SAVANNAH /KSAV/...22 SET IN 1958
RECORD LOW MAX TEMPS FOR FEBRUARY 20...
NORTH CHARLESTON /KCHS/...44 SET IN 1959
DOWNTOWN CHARLESTON /KCXM/...44 SET IN 1978
SAVANNAH /KSAV/...44 SET IN 1908
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR AMZ350-
352-354.
GALE WARNING UNTIL 2 PM EST THIS AFTERNOON FOR AMZ374.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
645 AM EST TUE FEB 17 2015
.SYNOPSIS...
LOW PRESSURE WILL MOVE OFF THE COAST TODAY. PRECIPITATION WILL END
EARLY THIS MORNING. WELL BELOW NORMAL TEMPERATURES EXPECTED
THROUGH THE WEEK UNDER THE INFLUENCE OF AN ARCTIC AIR MASS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST HRRR AND RAP GUIDANCE INDICATES PRECIPITATION LIKELY PUSH
EAST OF THE REGION EARLY THIS MORNING AS ISENTROPIC DOWN-GLIDE
DEVELOPS. WARNINGS AND ADVISORIES EXPIRE AT 700 AM. MODELS
INDICATE COLD ADVECTION DURING THE DAY AND CONSIDERABLE CLOUDINESS
UPSTREAM SO EXPECT TEMPERATURES TO STRUGGLE TO RISE THROUGH THE
40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
EASTERN CONUS UPPER LEVEL TROUGH AMPLIFIES TONIGHT AND WEDNESDAY
WITH RESULTING STRENGTHENING COLD ADVECTION. LIGHT WINDS TONIGHT
SO TEMPERATURES WILL FALL BELOW FREEZING. INCREASING WEST LOW
LEVEL WINDS EXPECTED DURING THE DAY WEDNESDAY...LAKE WIND ADVISORY
WILL LIKELY BE NEEDED WITH SUSTAINED WINDS AROUND 20 KTS AND
FREQUENT GUSTS ABOVE 30 KTS POSSIBLE. STRONG SHORT WAVES ROTATING
THROUGH REGION DURING THE DAY...DEEP MOISTURE LIMITED BUT CANT
RULE OUT SOME LIGHT SNOW SHOWERS IN THE AFTERNOON MAINLY NORTH
MIDLANDS. MODEL SOUNDINGS NORTH MIDLANDS SUPPORTS A LOW POPS IN
THAT REGION. CONSIDERABLE CLOUDS LIKELY THROUGH THE DAY THEN
CLEARING BEHIND THE SHORT WAVE IN THE EVENING. WINDS LIKELY TO
STAY UP THROUGH AT LEAST MIDNIGHT WITH STRONG MIXING/CONTINUED
COLD ADVECTION. MAX TEMPERATURE FORECAST BELOW GUIDANCE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
GENERALLY DRY INTO THE WEEKEND. HIGH PRESSURE WILL BUILD IN FROM THE
WEST WITH A REINFORCING SHOT OF ARCTIC AIR MOVING INTO THE AREA
THURSDAY AND FRIDAY. ANOTHER LOW PRESSURE SYSTEM DEVELOPING IN
THE SOUTHERN PLAINS BY EARLY SATURDAY WILL MOVE INTO THE TN VALLEY
BY SUNDAY AS MORE HIGH PRESSURE BUILDS IN FROM THE NORTH. AS A
RESULT...A COLD AIR DAMMING SCENARIO MAY OVER THE WEEKEND INTO
MONDAY. STILL LOTS OF QUESTIONS REGARDING TIMING AND PLACEMENT OF
THIS NEXT SYSTEM AND THE POSSIBILITY OF ANY WINTRY PRECIPITATION
EARLY NEXT WEEK. BUT WITH SOME MANY MODEL UNCERTAINTIES AT THIS
TIME...FOR NOW WILL KEEP PRECIPITATION ALL LIQUID SATURDAY INTO
MONDAY WITH CHANCE POPS. TEMPERATURES GENERALLY BELOW NORMAL THROUGH
THE EXTENDED PERIOD...WITH WELL BELOW NORMAL TEMPERATURES THURSDAY
AND FRIDAY. IN FACT...CURRENT MEX/MEN GUIDANCE HAS TEMPERATURES
ABOUT 20 TO 25 DEGREES BELOW NORMAL FOR CAE AND AGS THURSDAY AND
FRIDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
IFR CIGS MVFR/VFR VSBYS ACROSS MOST OF THE AREA AS LOW PRESSURE
WORKS NORTHEAST ALONG THE COAST. EXPECT MVFR CIGS VFR VSBYS AFTER
16Z WITH VFR CIGS/VSBYS AFTER 19Z.
EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS EXPECTED WEDNESDAY
AND THURSDAY. CIG RESTRICTIONS AND SHOWER CHANCES COULD RETURN
SAT/SUN.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
604 AM EST TUE FEB 17 2015
.SYNOPSIS...
LOW PRESSURE WILL MOVE OFF THE COAST TODAY. PRECIPITATION WILL END
EARLY THIS MORNING. WELL BELOW NORMAL TEMPERATURES EXPECTED
THROUGH THE WEEK UNDER THE INFLUENCE OF AN ARCTIC AIR MASS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST HRRR AND RAP GUIDANCE INDICATES PRECIPITATION LIKELY PUSH
EAST OF THE REGION EARLY THIS MORNING AS ISENTROPIC DOWN-GLIDE
DEVELOPS. PLAN IS TO LET WARNINGS AND ADVISORIES EXPIRE AT 700 AM. MODELS
INDICATE COLD ADVECTION DURING THE DAY AND CONSIDERABLE CLOUDINESS
UPSTREAM SO EXPECT TEMPERATURES TO STRUGGLE TO RISE THROUGH THE
40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
EASTERN CONUS UPPER LEVEL TROUGH AMPLIFIES TONIGHT AND WEDNESDAY
WITH RESULTING STRENGTHENING COLD ADVECTION. LIGHT WINDS TONIGHT
SO TEMPERATURES WILL FALL BELOW FREEZING. INCREASING WEST LOW
LEVEL WINDS EXPECTED DURING THE DAY WEDNESDAY...LAKE WIND ADVISORY
WILL LIKELY BE NEEDED WITH SUSTAINED WINDS AROUND 20 KTS AND
FREQUENT GUSTS ABOVE 30 KTS POSSIBLE. STRONG SHORT WAVES ROTATING
THROUGH REGION DURING THE DAY...DEEP MOISTURE LIMITED BUT CANT
RULE OUT SOME LIGHT SNOW SHOWERS IN THE AFTERNOON MAINLY NORTH
MIDLANDS. MODEL SOUNDINGS NORTH MIDLANDS SUPPORTS A LOW POPS IN
THAT REGION. CONSIDERABLE CLOUDS LIKELY THROUGH THE DAY THEN
CLEARING BEHIND THE SHORT WAVE IN THE EVENING. WINDS LIKELY TO
STAY UP THROUGH AT LEAST MIDNIGHT WITH STRONG MIXING/CONTINUED
COLD ADVECTION. MAX TEMPERATURE FORECAST BELOW GUIDANCE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
GENERALLY DRY INTO THE WEEKEND. HIGH PRESSURE WILL BUILD IN FROM THE
WEST WITH A REINFORCING SHOT OF ARCTIC AIR MOVING INTO THE AREA
THURSDAY AND FRIDAY. ANOTHER LOW PRESSURE SYSTEM DEVELOPING IN
THE SOUTHERN PLAINS BY EARLY SATURDAY WILL MOVE INTO THE TN VALLEY
BY SUNDAY AS MORE HIGH PRESSURE BUILDS IN FROM THE NORTH. AS A
RESULT...A COLD AIR DAMMING SCENARIO MAY OVER THE WEEKEND INTO
MONDAY. STILL LOTS OF QUESTIONS REGARDING TIMING AND PLACEMENT OF
THIS NEXT SYSTEM AND THE POSSIBILITY OF ANY WINTRY PRECIPITATION
EARLY NEXT WEEK. BUT WITH SOME MANY MODEL UNCERTAINTIES AT THIS
TIME...FOR NOW WILL KEEP PRECIPITATION ALL LIQUID SATURDAY INTO
MONDAY WITH CHANCE POPS. TEMPERATURES GENERALLY BELOW NORMAL THROUGH
THE EXTENDED PERIOD...WITH WELL BELOW NORMAL TEMPERATURES THURSDAY
AND FRIDAY. IN FACT...CURRENT MEX/MEN GUIDANCE HAS TEMPERATURES
ABOUT 20 TO 25 DEGREES BELOW NORMAL FOR CAE AND AGS THURSDAY AND
FRIDAY.
&&
.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
IFR CIGS MVFR/VFR VSBYS ACROSS MOST OF THE AREA AS LOW PRESSURE
WORKS NORTHEAST ALONG THE COAST. EXPECT MVFR CIGS VFR VSBYS AFTER
16Z WITH VFR CIGS/VSBYS AFTER 19Z.
EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS EXPECTED WEDNESDAY
AND THURSDAY. CIG RESTRICTIONS AND SHOWER CHANCES COULD RETURN
SAT/SUN.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...ICE STORM WARNING UNTIL 7 AM EST THIS MORNING FOR SCZ015-016-
020-021.
FREEZING RAIN ADVISORY UNTIL 7 AM EST THIS MORNING FOR SCZ022-
026>028.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
758 AM CST TUE FEB 17 2015
.SHORT TERM...
301 AM CST
THROUGH WEDNESDAY...
EARLY MORNING WATER VAPOR IMAGERY SHOWS THE AMPLIFYING UPPER FLOW
PATTERN WHICH WILL BRING ANOTHER ROUND OF BITTERLY COLD AIR TO THE
AREA. A LARGE LONGWAVE TROUGH IS SPREAD ACROSS THE EASTERN TWO-
THIRDS OF NORTH AMERICA WHILE SHARP LONGWAVE RIDGING EXTENDS UP
THE WEST COAST. SEVERAL SUBTLE SHORTWAVES ARE EMBEDDED IN THE
NORTHERLY FLOW FROM NORTHERN CANADA TO THE CENTRAL PLAINS. THE
MAIN WAVE OF NOTE IS ONE THAT IS QUICKLY MOVING SOUTHWARD ACROSS
CENTRAL SASKATCHEWAN AND MANITOBA...AND WILL BRING THE PUSH OF
COLDEST AIR TOMORROW. IN THE NEAR TERM...A WAVE DROPPING
SOUTHEASTWARD FROM MINNESOTA WILL CROSS THE AREA EARLY THIS
MORNING. AT THE SURFACE...A COLD FRONT EXTENDS FROM LOW PRESSURE
OVER HUDSON BAY WITH A SECONDARY CIRCULATION OVER THE EASTERN U.P.
OF MICHIGAN. THE FRONT WILL CROSS THE AREA BY MID MORNING TURNING
WINDS NORTHWESTERLY. RADAR MOSAIC SHOWS LIGHT RETURNS ACROSS THE
AREA WHICH ARE PRODUCING SOME FLURRIES AND A LITTLE LIGHT SNOW.
BANDS OF LIGHT SNOW SHOWERS ARE APPROACHING IN CLOSER PROXIMITY TO
THE FRONT AND THE ASSOCIATED UPPER WAVE AND MAY RESULT IN SNOW
INTENSE ENOUGH TO LOWER VSBY TO A FEW MILES THANKS TO STEEP LOW
LEVEL LAPSE RATES ALLOWING FOR A CONVECTIVE COMPONENT. COVERAGE
WILL NOT BE THAT GREAT AND DURATION WILL BE SHORT BUT WILL WORK
LOW POPS THROUGH THE AREA THROUGH MID MORNING. H85 TEMPS FALL TO
-16 TO -20C BY LATE DAY WITH H92 TEMPS FROM -16 TO -18C YIELDING
HIGHS IN THE LOWER TEENS NORTH TO AROUND 20 SOUTH. THERE WILL NOT
BE MUCH IN THE WAY OF LARGE SCALE LIFT BY AFTERNOON WITH THE UPPER
TROUGH EXITING BUT LOW LEVEL LAPSE RATES AND CONTINUED CLOUD
COVER/MOISTURE MAY LEAD TO SOME FLURRY ACTIVITY THANKS TO THE
PRESENCE OF ICE CRYSTALS IN THE STEEP LAPSE RATE ZONE.
THE CENTRAL SASKATCHEWAN/MANITOBA TROUGH WORKS ACROSS THE AREA
TONIGHT. THIS TROUGH SHOULD BRING BETTER LARGE SCALE FORCING WITH IT
BUT ALSO ANOTHER ROUND OF STEEP LAPSE RATES WITH ANOTHER STRONG COLD
FRONT. AM CONCERNED THAT THERE WILL BE A HIGHER COVERAGE OF FAIRLY
INTENSE SNOW SHOWERS THAT ACCOMPANIES THE TROUGH/FRONT PASSAGE LATE
THIS EVENING AND OVERNIGHT. WITH A FAIRLY SHORT DURATION TO ANY
GIVEN SNOW SHOWER ACCUMULATION WOULD BE LIMITED BUT COULD FORESEE
GREATLY REDUCED VSBY IN THE SNOW SHOWERS THAT DO OCCUR WITH A QUICK
ACCUMULATION...NOT UNLIKE SOME OF THE SNOW SQUALLS THAT OCCURRED WITH
A FRONTAL PASSAGE OVER THE WEEKEND. AT THIS POINT OCCURRENCE LOOKS
TO END RIGHT AROUND THE START OF THE WEDNESDAY MORNING RUSH WHICH
ADDS TO THE CONCERN. WILL CONTINUE WITH SLIGHT AND LOW CHANCE POPS
FOR NOW BUT WILL PASS CONCERNS ALONG TO THE DAY SHIFT. STEEP LAPSE
RATES AND CONTINUED COLD ADVECTION MAY RESULT IN PERIODS OF FLURRIES
OR EVEN SOME ADDITIONAL LIGHT SNOW THROUGH MUCH OF WEDNESDAY. LAKE
EFFECT SNOW WILL SKIRT NORTHEAST PORTER COUNTY SO INTERMITTENT BOUTS
OF LIGHT SNOW WILL OCCUR WEDNESDAY. HIGH TEMPS WILL BE A BIT TRICKY
WITH DIFFERENCES IN THE TIMING OF THE ARRIVAL OF THE COLDEST AIR.
THE GFS REMAINS THE FASTEST WITH THE INFLUX OF H85 TEMPS OF -28C AND
H92 TEMPS OF -24C BY EARLY AFTERNOON...WHILE THE NAM/ECMWF ARE
SLOWER WITH THE ARRIVAL OF AIR THIS COLD UNTIL EVENING. LOCAL
H85/H92 CLIMO UTILIZING A SLOWER ARRIVAL OF THE COLDEST AIR SIDES
MORE WITH SOME OF THE BETTER PERFORMING GUIDANCE OF LATE SUGGESTING
HIGHS IN THE UPPER SINGLE DIGITS NORTHWEST TO THE LOWER TEENS
SOUTHEAST. THESE MAY OCCUR EARLY WITH FALLING TEMPS THROUGH THE DAY.
BASED ON GREATER SUPPORT FOR SLIGHTLY WARMER HIGHS...AT LEAST
EARLY...WILL NUDGE VALUES UP A FEW DEGREES. STEADY NORTHWEST WINDS
WILL KEEP TEMPS FROM RADIATING OUT WEDNESDAY NIGHT THOUGH THEY WILL
STILL FALL TO BETWEEN ABOUT 2 BELOW AND 10 BELOW. THE WINDS WILL
ALSO PUSH WIND CHILLS TO BETWEEN -20 AND -30 F INTO THURSDAY MORNING
SO A WIND CHILL ADVISORY WILL LIKELY BE NEEDED.
MDB
&&
.LONG TERM...
301 AM CST
THURSDAY THROUGH MONDAY...
HIGH PRESSURE WILL STRETCH FROM
MANITOBA TO THE LOWER MISSISSIPPI RIVER VALLEY THURSDAY MORNING AND
STEADILY SLIDE EASTWARD. WESTERN UPPER RIDGING WILL BREAK DOWN AND
BE PUSHED EASTWARD INTO THE AREA AHEAD OF A TROUGH THAT WILL BE
DROPPING SOUTHEAST ACROSS WESTERN CANADA. TIMING OF TEMP
MODIFICATION WILL AGAIN BE AN ISSUE WITH THE GFS BEING THE SLOWEST
ON THE ARRIVAL OF WARMING ALOFT. THE DIFFERENCES MAY BE MOOT AS THE
HIGH WILL BE PASSING OVERHEAD LEAVING WEAK LOW LEVEL FLOW AND WEAK
MIXING. WILL CONTINUE WITH HIGHS FROM ROUND 5 NORTH TO 10 SOUTH
THURSDAY. LAKE EFFECT SNOW CHANCES WILL CONTINUE ACROSS NORTHEAST
PORTER COUNTY THURSDAY BEFORE SUBSIDENCE STARTS TO LIMIT LAKE EFFECT
BY THURSDAY EVENING. THE PATTERN SHIFTS INTO THE WEEKEND WITH THE
BIG EASTERN TROUGH BEING KICKED OUT INTO THE ATLANTIC AND A MORE
ZONAL FLOW SETTING UP ACROSS MOST OF THE U.S. THE AFOREMENTIONED
WESTERN CANADA TROUGH WILL CONTINUE EASTWARD FRIDAY AND MAY BRING
SOME PRECIP TO THE REGION. ENERGY THEN DIGS INTO THE WESTERN U.S.
TRIGGERING SFC LOW DEVELOPMENT OVER TEXAS BY SATURDAY. THIS LOW WILL
RIDE NORTHEAST ALONG A BAROCLINIC ZONE INTO SUNDAY WITH GUIDANCE
CONTINUING TO BE AT ODDS WITH WHERE EXACTLY THE TRACK WILL SET
UP...THOUGH THE SIGNAL FOR THIS SYSTEM OCCURRING IS BECOMING MORE
CONSISTENT. WILL NEED TO KEEP AN EYE ON THIS AS IT WILL DICTATE POPS
OVER THE WEEKEND. WITH THE PATTERN SHIFT TEMPS WILL MODERATE INTO
THE UPPER 20S AND POSSIBLY LOWER 30S SATURDAY WITH COOLER READINGS
SUNDAY AND MONDAY AS ANOTHER STRONG HIGH PRESSURE SYSTEM WILL TAKE
OVER. LESS AMPLIFIED FLOW WILL BE IN PLACE SO THE COOL DOWN WILL NOT
BE AS NOTABLE WITH HIGHS LOOKING TO BE AROUND 20.
MDB
&&
.CLIMATE...
WHILE THE COLDEST AIR ALOFT ARRIVES WEDNESDAY...THE COLDEST SURFACE
TEMPERATURES MAY RESULT ON THURSDAY FEBRUARY 19TH...WHICH RIGHT NOW
APPEARS COULD JEOPARDIZE SOME RECORDS...ESPECIALLY THE LOW MAXS.
FEB 19TH
RECORD LOW RECORD LOW MAX
CHICAGO -7 (1936) 9 (1936)
ROCKFORD -16 (1979) 7 (1959)
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* A FEW LINGERING SNOW SHOWERS EARLY THIS MORNING THROUGH AROUND
16 UTC...POSSIBLE PERIODS OF LOW MVFR CIGS/VIS.
* POTENTIAL FOR A SHORT PERIOD OF HEAVIER SNOW SHOWERS LATE TONIGHT
WITH IFR POSSIBLE.
KREIN
//DISCUSSION...UPDATED 12Z...
A COLD FRONT IS IN THE PROCESS OF MOVING ACROSS NORTHERN ILLINOIS.
ONCE THIS FRONT PASSES WE WILL SEE A QUICK END TO THE LIGHT SNOW
SHOWERS AND FLURRIES FOR A PERIOD. WINDS WILL TREND TOWARDS A WEST-
NORTHWEST DIRECTION AROUND 290 DEGREES WITH SOME LOW END GUSTS UP
AROUND 18 KT POSSIBLE AT TIMES THROUGH THE DAY.
LATER TODAY NIGHT A STRONGER ATMOSPHERIC DISTURBANCE IS EXPECTED TO
MOVE OVER THE AREA. AS THIS DOES SO...A PERIOD OF HEAVIER SNOW
SHOWERS COULD OCCUR...AND THIS COULD RESULT IN REDUCED
VISIBILITIES AND SOME MINOR SNOW ACCUMULATIONS. AT THIS TIME IT
APPEARS THE BEST POTENTIAL WOULD COME AFTER 06 UTC WEDNESDAY
MORNING AND LAST THROUGH THE PREDAWN HOURS OF WEDNESDAY MORNING. I
HAVE CONTINUED THE PROB 30 MENTION OF THIS AT KORD AND ADDED IN
FOR THE OTHER TERMINALS UNTIL A MORE PRECISE TIMING CAN BE IRONED
OUT.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM TO HIGH CONFIDENCE IN OCNL MVFR CIGS/VIS WITH LINGERING
SNOW SHOWERS THIS MORNING.
* MEDIUM TO HIGH CONFIDENCE IN ENDING TIME OF SNOW SHOWERS THIS
MORNING.
* LOW TO MEDIUM ON EXTENT OF SNOW SHOWERS LATER TONIGHT.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR WITH WEST-NORTHWEST WINDS.
THURSDAY...MAINLY VFR. NORTHWEST WINDS.
FRIDAY...CHANCE OF SNOW. IFR POSSIBLE. GUSTY SOUTH WINDS.
SATURDAY...CHANCE OF SNOW. IFR POSSIBLE. SOUTHWEST WINDS BECOMING
NORTHWEST.
SUNDAY...MAINLY VFR. NORTH-NORTHEAST WINDS.
MONDAY...VFR. WESTERLY WINDS.
KJB
&&
.MARINE...
148 AM CST
A PERIOD OF STRONG NORTHWESTERLY WINDS WILL SET UP ACROSS THE LAKE
ON WEDNESDAY AS THE GRADIENT TIGHTENS IN RESPONSE TO THE APPROACH OF
AN ARCTIC SURFACE HIGH OVER THE NORTHERN PLAINS. IT APPEARS THESE
STRONG NORTHWEST WINDS WILL CONTINUE WEDNESDAY NIGHT...WITH A SOLID
30 KT OF WIND EXPECTED. IT ALSO APPEARS THAT SOME 35 KT GALES COULD
OCCUR AT TIMES ACROSS THE SOUTH END OF LAKE MICHIGAN DURING THIS
PERIOD. ALTHOUGH THIS APPEARS TO BE A MARGINAL EVENT FOR GALES...IF
ANY GOOD CONVERGENT BANDS OF LAKE EFFECT SNOW SET UP...THIS COULD
PRODUCE PERIODS OF LOCALLY STRONGER WINDS OVER SOUTHERN AND
EASTERN PORTIONS OF THE LAKE. THEREFORE...I HAVE OPTED TO GO
AHEAD WITH A GALE WATCH FOR WEDNESDAY AND WEDNESDAY NIGHT OVER
SOUTHERN LAKE MICHIGAN...EXCLUDING THE NEAR SHORE WATERS. I WILL
ALSO INCLUDE A HEAVY FREEZING SPRAY WATCH FOR THESE SAME AREAS DUE
TO THE VERY COLD AIRMASS EXPECTED CONCURRENTLY WITH THESE STRONG
WINDS.
WINDS WILL EASE BAY THURSDAY AS THE SURFACE RIDGE OF HIGH PRESSURE
BEGINS TO SHIFT OVER THE WESTERN LAKES REGION. HOWEVER...IT APPEARS
THAT WINDS WILL QUICKLY PICK UP OUT OF THE SOUTH BY FRIDAY AS
ANOTHER CLIPPER SYSTEM TRACKS ACROSS SOUTHERN CANADA. THIS COULD
RESULT IN 30 KT SOUTHERLY WINDS AND MORE FREEZING SPRAY LAKE-WIDE ON
FRIDAY.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...6 AM
WEDNESDAY TO 3 AM THURSDAY.
HEAVY FREEZING SPRAY WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-
LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-
LMZ878...6 AM WEDNESDAY TO 3 AM THURSDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
558 AM CST Tue Feb 17 2015
.SHORT TERM...(Today)
ISSUED AT 330 AM CST TUE FEB 17 2015
A shortwave will trigger scattered flurries early this morning
across a large portion of central and southeast IL. The back edge
of the band of clouds/flurries is approaching NW IL at 3 am, and
should progress from NW to SE across the area this morning. Will
keep a mention of flurries along that band of clouds as it
progresses across the area.
Even in the clearing behind the shortwave, forecast soundings show
enough residual low level moisture for clouds to redevelop in any
periods of sunshine. Will work a period of clearing in the NW
counties later this morning, but increase clouds again later in the
afternoon.
The short range models continue to show a fast moving wave just west
of IL triggering a band of light snow later this afternoon. As the
wave curves around the south end of IL, snow showers will begin to
develop just south of our counties toward sunset. Have stuck with
just flurries for the snow forecast, and will not carry PoPs for
measurable snow near that feature.
Clear skies and light winds in the areas with new snow cover has
allowed temps early this morning to drop significantly below
guidance. Robinson has reached -10F, Lawrenceville -5, and Mount
Carmel -4 at 3 am. Unless the SE areas see some sunshine early this
afternoon, their highs will likely be affected by the bitterly cold
start to the day. Will trim a few degrees from forecast highs in the
southeast, and remain closer to a MAV/MET blend farther north.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 330 AM CST TUE FEB 17 2015
00Z models continue to dig a strong upper level trof into the
Midwest during midweek and usher in more arctic air into the region
with the coldest temps from Wed thru Thu. A wind chill advisory will
eventually be needed Wed night and Thu morning across central and
southeast IL for wind chills of 15-25 below zero.
A northern stream short wave that digs into the trof over IL/IN
tonight keeps most of its light snow just south of central IL CWA
though scattered flurries will likely occur tonight into Wed. 850 mb
temps drop to -25 to -27C by Wed evening and this to be another
frigid air mass with highs struggling to reach 10F both Wed and Thu.
Lows Tue night in the single digits, then drop into single digits
below zero Wed night and some areas near IN border could dip below
zero again Thu night. A secondary arctic cold front plows se through
central IL late tonight into Wed morning. Brisk nw winds behind this
cold front on Wed will already bring wind chills down to -15F or a
bit colder Wed morning over IL river valley especially nw of the
river and reaching near wind chill advisory criteria. Coldest wind
chills of 15-25 below zero will occur Wed night into Thu morning and
coldest readings over Knox and Stark counties.
Deep upper level trof shifts east of IL Thu night and Friday while
arctic high pressure also drifts east of IL across the Ohio river
valley Thu night and Fri morning. Temps will be slow to climb
however on Friday due to mostly cloudy skies with highs in the low to
mid 20s. Have small chances of light snow Friday afternoon sw
counties ahead of next short wave. Extended models still differ with
handling southern stream storm system this weekend. ECWMF model has
trended further south with it surface low from central IL down to
just south of IL Sat. While GFS has surface low near KY/TN border by
midnight Sat night. GEM model moves low across TN on Sat. Due to
difference in models and from previous runs, stayed close to
guidance pops which are trending upward in southeast IL Sat/Sat
night. Looks cold enough for mainly light snow, though do continue a
mix over southeast IL on Sat. Have just slight chance of light snow
Sunday and then dry across area by Sunday evening. Highs in the low
to mid 30s Sat cool off again early next week on Sunday and Monday
behind this storm system.
The Climate Prediction Center (CPC) day 8-14 outlook for Feb 24-Mar
2 has IL in greater than 60% chance of below normal temperatures and
greater than 40% chance of below normal precipitation. So winter
looks to hold on the next two weeks.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 558 AM CST TUE FEB 17 2015
Low VFR cigs and flurries will affect the TAF sites for a few
hours early this TAF period, under a weak surface trough. A brief
period of MVFR clouds could occur at BMI, but kept the prevailing
conditions VFR. The trough will slide east this morning, with some
clearing for a few hours behind it. HRRR and RAP output indicate
clouds will redevelop during the day as a cold front pushes SE
across the area. Flurries will be possible with that feature. A
strong 500mb vort max diving south tonight into the upper trough
axis will likely trigger MVFR clouds and widespread flurries or
snow showers. Have included prevailing light snow beginning around
06z tonight, but did not introduce any MVFR vis restrictions with
this TAF issuance.
W-SW winds early this morning will become northwest late this
morning, then increase this afternoon to 12-14kts sustained and
gusts to 22kt. Wind gusts will diminish this evening, but
sustained winds could remain around 10kt for much of the night as
the vigorous shortwave moves south into Illinois.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Shimon
LONG TERM...07
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
507 AM CST TUE FEB 17 2015
.SHORT TERM...
301 AM CST
THROUGH WEDNESDAY...
EARLY MORNING WATER VAPOR IMAGERY SHOWS THE AMPLIFYING UPPER FLOW
PATTERN WHICH WILL BRING ANOTHER ROUND OF BITTERLY COLD AIR TO THE
AREA. A LARGE LONGWAVE TROUGH IS SPREAD ACROSS THE EASTERN TWO-
THIRDS OF NORTH AMERICA WHILE SHARP LONGWAVE RIDGING EXTENDS UP
THE WEST COAST. SEVERAL SUBTLE SHORTWAVES ARE EMBEDDED IN THE
NORTHERLY FLOW FROM NORTHERN CANADA TO THE CENTRAL PLAINS. THE
MAIN WAVE OF NOTE IS ONE THAT IS QUICKLY MOVING SOUTHWARD ACROSS
CENTRAL SASKATCHEWAN AND MANITOBA...AND WILL BRING THE PUSH OF
COLDEST AIR TOMORROW. IN THE NEAR TERM...A WAVE DROPPING
SOUTHEASTWARD FROM MINNESOTA WILL CROSS THE AREA EARLY THIS
MORNING. AT THE SURFACE...A COLD FRONT EXTENDS FROM LOW PRESSURE
OVER HUDSON BAY WITH A SECONDARY CIRCULATION OVER THE EASTERN U.P.
OF MICHIGAN. THE FRONT WILL CROSS THE AREA BY MID MORNING TURNING
WINDS NORTHWESTERLY. RADAR MOSAIC SHOWS LIGHT RETURNS ACROSS THE
AREA WHICH ARE PRODUCING SOME FLURRIES AND A LITTLE LIGHT SNOW.
BANDS OF LIGHT SNOW SHOWERS ARE APPROACHING IN CLOSER PROXIMITY TO
THE FRONT AND THE ASSOCIATED UPPER WAVE AND MAY RESULT IN SNOW
INTENSE ENOUGH TO LOWER VSBY TO A FEW MILES THANKS TO STEEP LOW
LEVEL LAPSE RATES ALLOWING FOR A CONVECTIVE COMPONENT. COVERAGE
WILL NOT BE THAT GREAT AND DURATION WILL BE SHORT BUT WILL WORK
LOW POPS THROUGH THE AREA THROUGH MID MORNING. H85 TEMPS FALL TO
-16 TO -20C BY LATE DAY WITH H92 TEMPS FROM -16 TO -18C YIELDING
HIGHS IN THE LOWER TEENS NORTH TO AROUND 20 SOUTH. THERE WILL NOT
BE MUCH IN THE WAY OF LARGE SCALE LIFT BY AFTERNOON WITH THE UPPER
TROUGH EXITING BUT LOW LEVEL LAPSE RATES AND CONTINUED CLOUD
COVER/MOISTURE MAY LEAD TO SOME FLURRY ACTIVITY THANKS TO THE
PRESENCE OF ICE CRYSTALS IN THE STEEP LAPSE RATE ZONE.
THE CENTRAL SASKATCHEWAN/MANITOBA TROUGH WORKS ACROSS THE AREA
TONIGHT. THIS TROUGH SHOULD BRING BETTER LARGE SCALE FORCING WITH IT
BUT ALSO ANOTHER ROUND OF STEEP LAPSE RATES WITH ANOTHER STRONG COLD
FRONT. AM CONCERNED THAT THERE WILL BE A HIGHER COVERAGE OF FAIRLY
INTENSE SNOW SHOWERS THAT ACCOMPANIES THE TROUGH/FRONT PASSAGE LATE
THIS EVENING AND OVERNIGHT. WITH A FAIRLY SHORT DURATION TO ANY
GIVEN SNOW SHOWER ACCUMULATION WOULD BE LIMITED BUT COULD FORESEE
GREATLY REDUCED VSBY IN THE SNOW SHOWERS THAT DO OCCUR WITH A QUICK
ACCUMULATION...NOT UNLIKE SOME OF THE SNOW SQUALLS THAT OCCURRED WITH
A FRONTAL PASSAGE OVER THE WEEKEND. AT THIS POINT OCCURRENCE LOOKS
TO END RIGHT AROUND THE START OF THE WEDNESDAY MORNING RUSH WHICH
ADDS TO THE CONCERN. WILL CONTINUE WITH SLIGHT AND LOW CHANCE POPS
FOR NOW BUT WILL PASS CONCERNS ALONG TO THE DAY SHIFT. STEEP LAPSE
RATES AND CONTINUED COLD ADVECTION MAY RESULT IN PERIODS OF FLURRIES
OR EVEN SOME ADDITIONAL LIGHT SNOW THROUGH MUCH OF WEDNESDAY. LAKE
EFFECT SNOW WILL SKIRT NORTHEAST PORTER COUNTY SO INTERMITTENT BOUTS
OF LIGHT SNOW WILL OCCUR WEDNESDAY. HIGH TEMPS WILL BE A BIT TRICKY
WITH DIFFERENCES IN THE TIMING OF THE ARRIVAL OF THE COLDEST AIR.
THE GFS REMAINS THE FASTEST WITH THE INFLUX OF H85 TEMPS OF -28C AND
H92 TEMPS OF -24C BY EARLY AFTERNOON...WHILE THE NAM/ECMWF ARE
SLOWER WITH THE ARRIVAL OF AIR THIS COLD UNTIL EVENING. LOCAL
H85/H92 CLIMO UTILIZING A SLOWER ARRIVAL OF THE COLDEST AIR SIDES
MORE WITH SOME OF THE BETTER PERFORMING GUIDANCE OF LATE SUGGESTING
HIGHS IN THE UPPER SINGLE DIGITS NORTHWEST TO THE LOWER TEENS
SOUTHEAST. THESE MAY OCCUR EARLY WITH FALLING TEMPS THROUGH THE DAY.
BASED ON GREATER SUPPORT FOR SLIGHTLY WARMER HIGHS...AT LEAST
EARLY...WILL NUDGE VALUES UP A FEW DEGREES. STEADY NORTHWEST WINDS
WILL KEEP TEMPS FROM RADIATING OUT WEDNESDAY NIGHT THOUGH THEY WILL
STILL FALL TO BETWEEN ABOUT 2 BELOW AND 10 BELOW. THE WINDS WILL
ALSO PUSH WIND CHILLS TO BETWEEN -20 AND -30 F INTO THURSDAY MORNING
SO A WIND CHILL ADVISORY WILL LIKELY BE NEEDED.
MDB
&&
.LONG TERM...
301 AM CST
THURSDAY THROUGH MONDAY...
HIGH PRESSURE WILL STRETCH FROM
MANITOBA TO THE LOWER MISSISSIPPI RIVER VALLEY THURSDAY MORNING AND
STEADILY SLIDE EASTWARD. WESTERN UPPER RIDGING WILL BREAK DOWN AND
BE PUSHED EASTWARD INTO THE AREA AHEAD OF A TROUGH THAT WILL BE
DROPPING SOUTHEAST ACROSS WESTERN CANADA. TIMING OF TEMP
MODIFICATION WILL AGAIN BE AN ISSUE WITH THE GFS BEING THE SLOWEST
ON THE ARRIVAL OF WARMING ALOFT. THE DIFFERENCES MAY BE MOOT AS THE
HIGH WILL BE PASSING OVERHEAD LEAVING WEAK LOW LEVEL FLOW AND WEAK
MIXING. WILL CONTINUE WITH HIGHS FROM ROUND 5 NORTH TO 10 SOUTH
THURSDAY. LAKE EFFECT SNOW CHANCES WILL CONTINUE ACROSS NORTHEAST
PORTER COUNTY THURSDAY BEFORE SUBSIDENCE STARTS TO LIMIT LAKE EFFECT
BY THURSDAY EVENING. THE PATTERN SHIFTS INTO THE WEEKEND WITH THE
BIG EASTERN TROUGH BEING KICKED OUT INTO THE ATLANTIC AND A MORE
ZONAL FLOW SETTING UP ACROSS MOST OF THE U.S. THE AFOREMENTIONED
WESTERN CANADA TROUGH WILL CONTINUE EASTWARD FRIDAY AND MAY BRING
SOME PRECIP TO THE REGION. ENERGY THEN DIGS INTO THE WESTERN U.S.
TRIGGERING SFC LOW DEVELOPMENT OVER TEXAS BY SATURDAY. THIS LOW WILL
RIDE NORTHEAST ALONG A BAROCLINIC ZONE INTO SUNDAY WITH GUIDANCE
CONTINUING TO BE AT ODDS WITH WHERE EXACTLY THE TRACK WILL SET
UP...THOUGH THE SIGNAL FOR THIS SYSTEM OCCURRING IS BECOMING MORE
CONSISTENT. WILL NEED TO KEEP AN EYE ON THIS AS IT WILL DICTATE POPS
OVER THE WEEKEND. WITH THE PATTERN SHIFT TEMPS WILL MODERATE INTO
THE UPPER 20S AND POSSIBLY LOWER 30S SATURDAY WITH COOLER READINGS
SUNDAY AND MONDAY AS ANOTHER STRONG HIGH PRESSURE SYSTEM WILL TAKE
OVER. LESS AMPLIFIED FLOW WILL BE IN PLACE SO THE COOL DOWN WILL NOT
BE AS NOTABLE WITH HIGHS LOOKING TO BE AROUND 20.
MDB
&&
.CLIMATE...
WHILE THE COLDEST AIR ALOFT ARRIVES WEDNESDAY...THE COLDEST SURFACE
TEMPERATURES MAY RESULT ON THURSDAY FEBRUARY 19TH...WHICH RIGHT NOW
APPEARS COULD JEOPARDIZE SOME RECORDS...ESPECIALLY THE LOW MAXS.
FEB 19TH
RECORD LOW RECORD LOW MAX
CHICAGO -7 (1936) 9 (1936)
ROCKFORD -16 (1979) 7 (1959)
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* POTENTIAL FOR A SHORT PERIOD OF HEAVIER SNOW SHOWERS LATE TONIGHT
WITH IFR POSSIBLE.
KJB
//DISCUSSION...UPDATED 12Z...
A COLD FRONT IS IN THE PROCESS OF MOVING ACROSS NORTHERN ILLINOIS.
ONCE THIS FRONT PASSES WE WILL SEE A QUICK END TO THE LIGHT SNOW
SHOWERS AND FLURRIES FOR A PERIOD. WINDS WILL TREND TOWARDS A WEST-
NORTHWEST DIRECTION AROUND 290 DEGREES WITH SOME LOW END GUSTS UP
AROUND 18 KT POSSIBLE AT TIMES THROUGH THE DAY.
LATER TODAY NIGHT A STRONGER ATMOSPHERIC DISTURBANCE IS EXPECTED TO
MOVE OVER THE AREA. AS THIS DOES SO...A PERIOD OF HEAVIER SNOW
SHOWERS COULD OCCUR...AND THIS COULD RESULT IN REDUCED
VISIBILITIES AND SOME MINOR SNOW ACCUMULATIONS. AT THIS TIME IT
APPEARS THE BEST POTENTIAL WOULD COME AFTER 06 UTC WEDNESDAY
MORNING AND LAST THROUGH THE PREDAWN HOURS OF WEDNESDAY MORNING. I
HAVE CONTINUED THE PROB 30 MENTION OF THIS AT KORD AND ADDED IN
FOR THE OTHER TERMINALS UNTIL A MORE PRECISE TIMING CAN BE IRONED
OUT.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* LOW TO MEDIUM ON EXTENT OF SNOW SHOWERS LATER TONIGHT.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR WITH WEST-NORTHWEST WINDS.
THURSDAY...MAINLY VFR. NORTHWEST WINDS.
FRIDAY...CHANCE OF SNOW. IFR POSSIBLE. GUSTY SOUTH WINDS.
SATURDAY...CHANCE OF SNOW. IFR POSSIBLE. SOUTHWEST WINDS BECOMING
NORTHWEST.
SUNDAY...MAINLY VFR. NORTH-NORTHEAST WINDS.
MONDAY...VFR. WESTERLY WINDS.
KJB
&&
.MARINE...
148 AM CST
A PERIOD OF STRONG NORTHWESTERLY WINDS WILL SET UP ACROSS THE LAKE
ON WEDNESDAY AS THE GRADIENT TIGHTENS IN RESPONSE TO THE APPROACH OF
AN ARCTIC SURFACE HIGH OVER THE NORTHERN PLAINS. IT APPEARS THESE
STRONG NORTHWEST WINDS WILL CONTINUE WEDNESDAY NIGHT...WITH A SOLID
30 KT OF WIND EXPECTED. IT ALSO APPEARS THAT SOME 35 KT GALES COULD
OCCUR AT TIMES ACROSS THE SOUTH END OF LAKE MICHIGAN DURING THIS
PERIOD. ALTHOUGH THIS APPEARS TO BE A MARGINAL EVENT FOR GALES...IF
ANY GOOD CONVERGENT BANDS OF LAKE EFFECT SNOW SET UP...THIS COULD
PRODUCE PERIODS OF LOCALLY STRONGER WINDS OVER SOUTHERN AND
EASTERN PORTIONS OF THE LAKE. THEREFORE...I HAVE OPTED TO GO
AHEAD WITH A GALE WATCH FOR WEDNESDAY AND WEDNESDAY NIGHT OVER
SOUTHERN LAKE MICHIGAN...EXCLUDING THE NEAR SHORE WATERS. I WILL
ALSO INCLUDE A HEAVY FREEZING SPRAY WATCH FOR THESE SAME AREAS DUE
TO THE VERY COLD AIRMASS EXPECTED CONCURRENTLY WITH THESE STRONG
WINDS.
WINDS WILL EASE BAY THURSDAY AS THE SURFACE RIDGE OF HIGH PRESSURE
BEGINS TO SHIFT OVER THE WESTERN LAKES REGION. HOWEVER...IT APPEARS
THAT WINDS WILL QUICKLY PICK UP OUT OF THE SOUTH BY FRIDAY AS
ANOTHER CLIPPER SYSTEM TRACKS ACROSS SOUTHERN CANADA. THIS COULD
RESULT IN 30 KT SOUTHERLY WINDS AND MORE FREEZING SPRAY LAKE-WIDE ON
FRIDAY.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...6 AM
WEDNESDAY TO 3 AM THURSDAY.
HEAVY FREEZING SPRAY WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-
LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-
LMZ878...6 AM WEDNESDAY TO 3 AM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
331 AM CST Tue Feb 17 2015
.SHORT TERM...(Today)
ISSUED AT 330 AM CST TUE FEB 17 2015
A shortwave will trigger scattered flurries early this morning
across a large portion of central and southeast IL. The back edge
of the band of clouds/flurries is approaching NW IL at 3 am, and
should progress from NW to SE across the area this morning. Will
keep a mention of flurries along that band of clouds as it
progresses across the area.
Even in the clearing behind the shortwave, forecast soundings show
enough residual low level moisture for clouds to redevelop in any
periods of sunshine. Will work a period of clearing in the NW
counties later this morning, but increase clouds again later in the
afternoon.
The short range models continue to show a fast moving wave just west
of IL triggering a band of light snow later this afternoon. As the
wave curves around the south end of IL, snow showers will begin to
develop just south of our counties toward sunset. Have stuck with
just flurries for the snow forecast, and will not carry PoPs for
measurable snow near that feature.
Clear skies and light winds in the areas with new snow cover has
allowed temps early this morning to drop significantly below
guidance. Robinson has reached -10F, Lawrenceville -5, and Mount
Carmel -4 at 3 am. Unless the SE areas see some sunshine early this
afternoon, their highs will likely be affected by the bitterly cold
start to the day. Will trim a few degrees from forecast highs in the
southeast, and remain closer to a MAV/MET blend farther north.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 330 AM CST TUE FEB 17 2015
00Z models continue to dig a strong upper level trof into the
Midwest during midweek and usher in more arctic air into the region
with the coldest temps from Wed thru Thu. A wind chill advisory will
eventually be needed Wed night and Thu morning across central and
southeast IL for wind chills of 15-25 below zero.
A northern stream short wave that digs into the trof over IL/IN
tonight keeps most of its light snow just south of central IL CWA
though scattered flurries will likely occur tonight into Wed. 850 mb
temps drop to -25 to -27C by Wed evening and this to be another
frigid air mass with highs struggling to reach 10F both Wed and Thu.
Lows Tue night in the single digits, then drop into single digits
below zero Wed night and some areas near IN border could dip below
zero again Thu night. A secondary arctic cold front plows se through
central IL late tonight into Wed morning. Brisk nw winds behind this
cold front on Wed will already bring wind chills down to -15F or a
bit colder Wed morning over IL river valley especially nw of the
river and reaching near wind chill advisory criteria. Coldest wind
chills of 15-25 below zero will occur Wed night into Thu morning and
coldest readings over Knox and Stark counties.
Deep upper level trof shifts east of IL Thu night and Friday while
arctic high pressure also drifts east of IL across the Ohio river
valley Thu night and Fri morning. Temps will be slow to climb
however on Friday due to mostly cloudy skies with highs in the low to
mid 20s. Have small chances of light snow Friday afternoon sw
counties ahead of next short wave. Extended models still differ with
handling southern stream storm system this weekend. ECWMF model has
trended further south with it surface low from central IL down to
just south of IL Sat. While GFS has surface low near KY/TN border by
midnight Sat night. GEM model moves low across TN on Sat. Due to
difference in models and from previous runs, stayed close to
guidance pops which are trending upward in southeast IL Sat/Sat
night. Looks cold enough for mainly light snow, though do continue a
mix over southeast IL on Sat. Have just slight chance of light snow
Sunday and then dry across area by Sunday evening. Highs in the low
to mid 30s Sat cool off again early next week on Sunday and Monday
behind this storm system.
The Climate Prediction Center (CPC) day 8-14 outlook for Feb 24-Mar
2 has IL in greater than 60% chance of below normal temperatures and
greater than 40% chance of below normal precipitaton. So winter
looks to hold on the next two weeks.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1110 PM CST MON FEB 16 2015
Low VFR cigs spreading slowly east and southeast late this
evening and should encompass all TAF sites by 09z. Cold front
pushing across east central Iowa will bring about a wind shift
Tuesday morning into the west and northwest along with a period
of MVFR cigs immediately behind the frontal passage. Latest RAP
and HRRR forecasts suggest the MVFR cigs should push into PIA
around 09z and finally into CMI at 12z. Based on the past several
forecast runs, it appears about a 2-3 hour period of MVFR cigs
before improving to VFR by 15z at PIA and 18z over in CMI.
500 mb trof axis still located to our west on Tuesday so if we do
see any breaks in the cloud cover, the rather cold 500 mb temps
will lead to some scattered to broken stratocu clouds between
3000-4000 feet during the afternoon. At this point will include a
scattered group at 3500 feet. A few flurries will be possible with
or just behind the cold front tomorrow morning and possibly again
the afternoon but at this time it appears coverage will be quite
limited so have decided to hold off any mention of flurries in
this set of TAFs. Surface winds will be light southwest overnight
and switch into the west around dawn Tuesday and then into the
northwest as the front shifts off to our east. Wind speeds tonight
will be less than 10 kts and increase to between 10 and 15 kts
on Tuesday with a few gusts near 20 kts by late morning or early
afternoon, before diminishing around sunset.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Shimon
LONG TERM...07
AVIATION...Smith
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
948 AM CST TUE FEB 17 2015
.UPDATE...
ISSUED AT 942 AM CST TUE FEB 17 2015
9AM TEMPERATURES ACROSS THE AREA WERE HIGHER THAN FORECAST FOR 10
AM. A QUICK LOOK AT THE RUC AND HRRR HIGH TEMPS AND THE SATELLITE
IMAGE...SUPPORTS DAYTIME HIGH TEMPS BEING SLIGHTLY HIGHER THAN
PREVIOUS FORECAST...ESPECIALLY ACROSS SOUTHERN PORTIONS OF THE
CWA. RAISED POPS A FEW DEGREES CWA WIDE. ALSO ADDED SN-- TO MORE
OF THE NW ZONES TODAY. AGITATED CU FIELD WAS LEADING TO FLURRIES
AS THEY HEADED SOUTH IN THE N TO NW FLOW. NO ACCUMULATION IS
EXPECTED DURING THE DAY FROM THESE FLURRIES.
&&
.SYNOPSIS...
ISSUED AT 342 AM CST TUE FEB 17 2015
MSAS SURFACE ANALYSIS INDICATED THE SURFACE COLD FRONT EXTENDED
FROM EASTERN UPPER MI SW ACROSS WI...EASTERN IA TO N CENTRAL KS AT
08Z. IN THE LOCAL AREA...THE BOUNDARY WAS ROUGHLY FROM KMSN
THROUGH THE QUAD CITIES TO JUST NORTH OF KIRK. A POST FRONTAL
SURGE OF MID LEVEL SUBSIDENCE AND DRY AIR HAD LEAD TO A LARGE AREA
OF CLEARING IN THE STRATOCU ACROSS MUCH OF CENTRAL IA...WITH
SATELLITE IR/FOG CHANNEL IMAGERY SHOWING PATCHY LOW CLOUDS UPSTREAM
UNDER THE NW FLOW ALOFT ACROSS MN AND THE DAKOTAS. KDVN 88D AND
SURFACE REPORTS INDICATED SCATTERED FLURRIES OR VERY LIGHT SNOW
SHOWERS PUSHING EAST AHEAD OF THE FRONT ACROSS NW IL. WITH A
RATHER UNIMPRESSIVE POST FRONTAL PRESSURE RISES...WINDS WERE ONLY
INCREASING TO 10 TO 15 KTS IMMEDIATELY BEHIND THE FRONT.
LIKEWISE...THE COLD AIR ADVECTION WAS ONLY LOWERING TEMPERATURES
INTO THE UPPER SINGLE DIGITS OVER NE IA...WHILE READINGS WERE
STEADY TO SLOWLY FALLING IN THE TEENS TO LOWER 20S OVER THE LOCAL
AREA. THE MORE IMPRESSIVE PUSH OF ARCTIC AIR WAS FURTHER NORTH
BEHIND A SUBTLE SECONDARY COLD FRONT ACROSS WI...MN INTO
SD...MARKING THE LEADING EDGE OF TEMPERATURES IN THE SINGLE DIGITS
BELOW ZERO TO THE NORTH.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM CST TUE FEB 17 2015
THE ONSET OF COLDER TEMPERATURES AND ASSOCIATED BITTER COLD WIND
CHILLS IS THE PRIMARY FOCUS. HAVE ISSUED A WIND CHILL ADVISORY
FOR LATE TONIGHT THROUGH WED MORNING OVER EASTERN IA...WHERE WIND
CHILLS WILL LIKELY DROP BELOW -20 FOR A SUFFICIENT PERIOD DUE TO
INCREASING NW WINDS AND FALLING TEMPERATURES BEHIND THE SECONDARY
FRONTAL SURGE LATE TONIGHT.
TODAY...TEMPERATURES HAVE BEEN ADJUSTED UPWARDS IN THE NEAR TERM
FOLLOWING A SLIGHTLY SLOWER FRONTAL PASSAGE AND WEAKER COLD AIR
ADVECTION THAT FOLLOWS. THROUGH THE REST OF THE DAY...THERE IS A
GOOD POTENTIAL FOR PERIODS OF SUNSHINE LOOKING AT THE LIMITED EXTENT
OF LOW CLOUDS UPSTREAM AND MEAGER MOISTURE ON AREA SOUNDINGS. STEEP
LOW LEVEL LAPSE RATES AND A SHALLOW LOW LEVEL MOISTURE LAYER MOVING
OUT OF THE PLAINS WILL SUPPORT FLURRIES OVER ESPECIALLY THE SOUTH.
AFTER FALLING THROUGH AT LEAST MID MORNING...TEMPERATURES SHOULD
RECOVER TO HIGHS FROM AROUND 10 NORTH TO 20 IN THE FAR SOUTH.
TONIGHT...AN ADVANCING...STRENGTHENING UPPER LEVEL SHORTWAVE
TROUGH AND REINFORCING SHOT OF COLD AIR ADVECTION WILL LIKELY
SPREAD SCATTERED SNOW SHOWERS OR FLURRIES OVER THE FORECAST AREA.
WILL HAVE HIGHER CHANCE POPS FOR POSSIBLE DUSTING OF ACCUMULATION
ACROSS THE NORTH AND NORTHEAST. DEVELOPING NW WINDS FROM 15 TO 25
MPH AND TEMPERATURES FALLING TO AROUND ZERO IN THE NORTH TOWARD
DAWN WILL LIKELY DRIVE WIND CHILLS INTO THE ADVISORY THRESHOLD
RANGE OF -20 AND BELOW BEGINNING AFTER ABOUT 3 AM...MAINLY OVER
EAST CENTRAL IA. CURRENT FORECAST PARAMETERS HAVE WIND CHILLS
MAINLY IN THE MINUS TEENS ELSEWHERE. MIN TEMPERATURES FORECAST IN
A RANGE OF 3 BELOW TO 3 ABOVE WILL LIKELY OCCUR AFTER SUNRISE.
BASED ON BIASES FROM RECENT EVENTS AND THE LATE SEASON TIMING...HAVE
TRENDED TEMPERATURES ON THE WARMER SIDE OF FORECAST GUIDANCE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 342 AM CST TUE FEB 17 2015
THE CONSISTENT MESSAGE IS A CONTINUATION OF WELL BELOW NORMAL
TEMPERATURES FOR THE AREA.
THE PROXIMITY OF THE UPPER LEVEL DISTURBANCE AT SUNRISE WEDNESDAY
SUGGESTS THAT SOME FLURRIES MAY PERSIST INTO THE FIRST PART OF THE
MORNING ACROSS THE FAR EAST AND NORTHEAST AREAS. ONCE THE
DISTURBANCE MOVES INTO THE GREAT LAKES SKIES SHOULD SLOWLY CLEAR
DURING THE DAY.
THE STRONGER SUN ANGLE SHOULD PARTIALLY HELP TO OFFSET THE COLD AIR
ADVECTING INTO THE AREA ON WEDNESDAY. REGARDLESS...IT WILL BE VERY
COLD WITH MAX TEMPERATURES 25 TO 30 DEGREES BELOW NORMAL.
THE ARCTIC HIGH SETTLES ACROSS THE AREA WEDNESDAY NIGHT RESULTING IN
BITTER COLD. BASED ON FORECAST LOWS AND WIND SPEEDS...HEADLINES FOR
WIND CHILL WILL BE NEEDED FOR MUCH OF THE AREA WEDNESDAY NIGHT THAT
EXTENDS INTO THURSDAY MORNING. CONFIDENCE ON THIS IS NOW MODERATE TO
HIGH.
QUIET AND COLD CONDITIONS WILL BE SEEN ACROSS THE AREA ON THURSDAY
AS THE ARCTIC HIGH MOVES ACROSS THE AREA. MAX TEMPERATURES WILL
CONTINUE TO BE 25 TO 30 DEGREES BELOW NORMAL.
QUIET AND DRY CONDITIONS WILL BE SEEN ACROSS THE AREA THURSDAY
EVENING. THERE SHOULD BE A QUICK DROP OFF IN TEMPERATURES BEFORE
CLOUDS ASSOCIATED WITH AN UPPER LEVEL DISTURBANCE MOVE INTO THE AREA.
LATE THURSDAY NIGHT A BAND OF LIGHT SNOW WILL MOVE ACROSS WESTERN
IOWA. MOST OF THE AREA WILL REMAIN DRY LATE THURSDAY NIGHT BUT THE
FAR SOUTHWEST AND SOUTH AREAS MAY SEE SOME FLURRIES OR LIGHT SNOW.
THE KEY TO WHETHER ANY PRECIPITATION OCCURS WILL BE THE DEPTH OF THE
DRY AIR ACROSS THE AREA.
FRIDAY ON...
THE MODELS CONTINUE THE TREND OF BELOW NORMAL TEMPERATURES THROUGH
NEXT WEEKEND AND INTO EARLY NEXT WEEK.
THE SOUTHERN JET WILL REMAIN ACTIVE FROM THE SOUTHERN PLAINS INTO
THE TENNESSEE VALLEY BUT SEVERAL WEAK DISTURBANCES WILL BE MOVING
SOUTHEAST ACROSS THE AREA IN THE NORTHERN JET. AS SUCH THERE WILL BE
SEVERAL CHANCES FOR FLURRIES OR VERY LIGHT SNOW FRIDAY THROUGH THE
FIRST PART OF THE WEEKEND. HOWEVER...LIMITED MOISTURE SUGGESTS ANY
SNOWFALL WOULD BE A TRACE TO A DUSTING MOST OF THE TIME.
THE MODEL CONSENSUS HAS SLIGHT CHANCE POPS FRIDAY/FRIDAY NIGHT AS
THE FIRST WEAK DISTURBANCE MOVES THROUGH THE AREA.
SATURDAY/SATURDAY NIGHT THE MODEL CONSENSUS HAS SLIGHT CHANCE TO
CHANCE POPS FOR MUCH OF THE AREA. THIS IS THE NEXT SIGNIFICANT STORM
SYSTEM THAT THE MODELS HAVE BEEN SUGGESTING FOR THE WEEKEND.
HOWEVER...THERE REMAINS QUESTIONS REGARDING HOW MUCH INTERACTION
THERE WILL BE BETWEEN THE NORTHERN AND SOUTHERN JETS. IF THE JETS
REMAIN SEPARATE...WHICH IS SUGGESTED BY THE OVERALL PATTERN...THEN
THIS STORM SYSTEM WOULD END UP BEING MUCH FURTHER SOUTH.
ADDITIONALLY...HOW FAST THE NEXT ARCTIC HIGH DROPS DOWN INTO THE
PLAINS AND UPPER MIDWEST WILL BE IMPORTANT. A FASTER ARRIVAL OF THE
ARCTIC HIGH WOULD ALSO SHUNT THE STORM SYSTEM FURTHER SOUTH.
SUNDAY THROUGH MONDAY THE MODEL CONSENSUS HAS DRY BUT COLD
CONDITIONS AS THE NEXT ARCTIC HIGH MOVES THROUGH THE MIDWEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 553 AM CST TUE FEB 17 2015
MOSTLY CLEAR SKIES AND VFR CONDITIONS WILL START OUT THE PERIOD...
FOLLOWED BY PERIODS OF LOW CLOUDS WITH MVFR CIGS AND FLURRIES BY
AFTERNOON THROUGH EVENING. ANOTHER COLD FRONT WILL CAUSE NORTHWEST
WINDS TO BECOME GUSTY AND INCREASE OVERNIGHT TONIGHT. THIS WILL
ALSO BRING A PERIOD OF LIGHT SNOW OR SNOW SHOWERS...ESPECIALLY TO
THE DBQ SITE IN THE EVENING. FOR NOW...THIS IS KEPT AS MVFR...BUT
THERE IS A POTENTIAL THAT CONDITIONS COULD LOWER TO IFR AT
DBQ...WHICH IS NOT INCLUDED IN THE CURRENT FORECAST. ALL SITES ARE
LIKELY TO SEE AT LEAST A PERIOD OF MVFR CONDITIONS OVERNIGHT
BEFORE IMPROVING TOWARD SUNRISE WEDNESDAY.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WIND CHILL ADVISORY FROM 3 AM TO NOON CST WEDNESDAY FOR BENTON-
BUCHANAN-CEDAR-CLINTON-DELAWARE-DUBUQUE-IOWA-JACKSON-
JOHNSON-JONES-LINN.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...GIBBS
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...08
AVIATION...SHEETS
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
702 AM CST Tue Feb 17 2015
.UPDATE:
Issued at 656 AM CST Tue Feb 17 2015
Latest few runs of the RAP model continue to focus in on southern
Missouri and southern Illinois counties for the heaviest snowfall
late this afternoon and this evening. The model is much more
robust with QPF and is supported by the latest 4km Local WRF with
around 0.25 inches in a band from Shannon County Missouri through
Reynolds, Iron and Madison. Have increasing confidence of the
main band location so have went ahead and increased POPs to
categorical and inched QPF/snowfall up a little more, but not to
the extend that the latest RAP suggests. I also expanded chance POPs
this evening further north into the St. Louis Metro as a stronger
shortwave would also lead to a more broad lighter snow shield to
develop north of the heaviest band ahead of the shortwave. In fact
the latest RAP suggests up to an inch as far north as the Missouri
River. Will brief oncoming dayshift of the trends in the short
term model guidance and the potential need for an advisory across
the far southern counties of the CWA late this afternoon and this
evening.
CVKING
&&
.SHORT TERM: (Through Late This Afternoon)
Issued at 332 AM CST Tue Feb 17 2015
Next shortwave helping to dig out the upper level trof across the
eastern 2/3rds of the CONUS will bring another shot of accumulating
snow across mainly the southern zones of the CWA this afternoon and
this evening. Used a model consensus approach for location of POPs
and increased them into the likely category. Dayshift will need to
fine tune and increase to categorical once the band of snow begins
to develop. Certainly appears that there will be enough lift and
moisture to justify increasing snowfall amounts a tad as well with
up to two inches possible within the band of snow. Otherwise,
temperatures today will respond nicely ahead of the approaching cold
front from the north, with highs ranging from the 20s north to the
30s south.
CVKING
.LONG TERM: (Tonight through Monday)
Issued at 332 AM CST Tue Feb 17 2015
(Wednesday through Thursday)
Focus thru this period will be temps with little in the way of
precip currently anticipated.
Have kept dry PoPs going for Wed attm. Given progd soundings thru
Wed, expect flurries to be possible throughout the day. However, it
seems plausible that bands will be possible where more than just
flurries may be possible. This, of course, is a short term forecast
issue.
Otherwise, only minor changes to temps have been made as prev
forecast still appears to be on track. Continued the cold trend, aob
coldest guidance at most times especially overnight. Mdls are in
good agreement with the sfc ridge building into the area Wed night.
As clouds clear out of the region, temps shud drop quickly with
snowpack across the region. Thurs shud be slightly warmer across
most of the CWA as the sfc ridge builds ewd and thermal ridge
approaches the area.
(Friday through Monday)
Overall, not a lot of change from the prev forecast thru the extd.
Mdls continue to indicate the potential for another measurable SN
event Thurs night into Fri. Mdls are in somewhat good agreement with
a s/w embedded within the NW flow Thurs night, with good low and mid
level frontogenesis. Mdls have come into slightly better agreement
and have raised PoPs a bit. However, questions remain regarding
exactly where this precip band may set up.
As the deep upper low finally pulls newd out into the nrn Atlantic,
flow become much more zonal this weekend with the next trof digging
into wrn U.S. Mdl spread increases with individual s/ws thru the
extd. The GEM becomes an outlier thru much of this period and have
trended away from this soln.
However, mdls are in relatively good agreement with a sfc low
developing with an associated trof on Sat. Increased PoPs across
mainly srn portions of the region. While mdl thermal profiles are
currently in close agreement, this may change as the system
approaches. Believe it was prudent to add another p-type as current
trends suggest that many p-types will be possible or probable.
However, have currently only added IP to the forecast as this is the
other dominant p-type currently expected. As the thermal ridge
builds into the area, it is very possible that precip will change
from SN, to IP, to FZRA to RA and back again during this event. Will
leave these details to future forecasts as confidence builds and
mdls come into better agreement.
Beyond this system, mdls build another ridge into the region,
bringing colder temps. However, current indications are that this
ridge will not be as cold as earlier this week.
Tilly
&&
.AVIATION: (For the 12z TAFs through 12z Wednesday Morning)
Issued at 516 AM CST Tue Feb 17 2015
Shortwave and attendant cold front will bring a wind shift and
chance of flurries or light snow to the terminals today. The cold
front should be through KUIN by 12Z and arrive during the lunch
hour at KCOU and the St. Louis Metro terminals. The cold front
will cause winds to shift from west to northwest. The upper level
disturbance (shortwave) will sweep across the region later this
afternoon and this evening with the greatest potential of
accumulating snow remaining south of the terminals across southern
Missouri and Illinois. At this time only expect flurries or very
light snow to be observed at the terminals. The wind will actually
back to the west again overnight ahead of an even stronger cold
front that is progged to arrive Wednesday morning. Gusty northwest
winds will accompany this secondary cold front.
Specifics for KSTL:
Have the front timed through St. Louis around 21Z with flurries or
very light snow lasting into the evening hours. Stronger front
arrives 12Z on Wednesday with coldest air of the season.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
339 AM MST TUE FEB 17 2015
.SHORT TERM...VALID FOR TDY AND WED...
SNOW SHOWER ACTIVITY EARLY THIS MORNING WILL GRADUALLY WANE TODAY
AND LEAD TO A DRIER WEATHER PATTERN TONIGHT AND WEDNESDAY.
A NARROW BAND OF RELATIVELY INTENSE SNOW FORMED AFTER MIDNIGHT IN
CENTRAL YELLOWSTONE COUNTY AND WAS CENTERED ACROSS THE BILLINGS
HEIGHTS WHERE SPOTTERS HAVE REPORTED UP TO 3 INCHES OF SNOW AS OF
300 AM MST. THIS BAND FORMED IN UNSTABLE NORTHWEST FLOW ALOFT...
AND WAS ENHANCED IN THE VICINITY OF A WEAK SURFACE WIND SHIFT. IT
WAS VERY NARROW /LESS THAN 5 MILES WIDE/ AND THUS VERY DIFFICULT
TO ANTICIPATE RIGHT UP UNTIL RADAR BEGAN TO SUPPORT ITS FORMATION.
SOME VERY RECENT RADAR TRENDS AS OF 330 AM MST SUGGEST THE BAND
IS WEAKENING...SO ADDITIONAL ACCUMULATION IN THE CITY THROUGH
EARLY THIS MORNING WILL LIKELY BE LESS THAN AN INCH.
OTHERWISE...SNOW SHOWER ACTIVITY IS ALSO CONTINUING OVER FAR SOUTH
CENTRAL MT AND NORTH CENTRAL WY AS OF 330 AM MST...AND OVERNIGHT
MODEL TRENDS SUGGEST IT WILL LINGER THROUGH THE MORNING. HRRR RUNS
EVEN HANG ONTO SNOW IN THE FORT SMITH AND SHERIDAN AREA RIGHT INTO
THE AFTERNOON...THOUGH WITH DECREASING INTENSITY IN TIME. WE THUS
EXTENDED THE WINTER WEATHER ADVISORY FOR BIG HORN...SOUTHERN ROSE-
BUD AND SHERIDAN COUNTIES AND THE NORTHEAST BIGHORN MOUNTAINS OUT
UNTIL NOON MST TODAY. ADDITIONAL ACCUMULATIONS SHOULD ONLY BE ONE
OR TWO INCHES...BUT ROADS WILL REMAIN SLIPPERY AND SNOW COVERED.
BY THIS EVENING...THE AIR MASS WILL BE STABILIZING AS THE HEIGHTS
ALOFT RISE. WE THUS HAVE A DRY FORECAST IN PLAY OVERNIGHT TONIGHT
AND INTO WEDNESDAY...THOUGH AS WARM AIR ADVECTION ALOFT GETS GOING
THERE ARE HINTS IN SOME 00 UTC GUIDANCE FOR VERY LIGHT SNOW ACROSS
SOUTHEASTERN MT TONIGHT INTO WEDNESDAY. FORECAST SOUNDINGS SUGGEST
SATURATION WILL BE LIMITED IN THE NEAR-SURFACE LAYER THOUGH AND SO
WE KEPT WITH THE IDEA OF A DRY FORECAST FOR NOW.
HIGHS TODAY WILL BE COOL...RANGING FROM THE TEENS EAST AND PERHAPS
IN AREAS WHERE SNOW COVER IS GREATEST TO THE 30S F ACROSS SOUTH
CENTRAL MT. WARMING WILL BEGIN IN EARNEST WEDNESDAY ACROSS SOUTH
CENTRAL MT WITH HIGHS IN THE 50S F IN THE FOOTHILLS...BUT MIXING
WILL BE LIMITED FURTHER EAST IN SOUTHEASTERN MT WITH CLOUD COVER
AND LIGHT SOUTHEAST WINDS AHEAD OF A DEVELOPING WARM FRONT. HIGHS
WILL THUS STAY IN THE 20S F WEDNESDAY ACROSS FAR SOUTHEASTERN MT
AND IN FACT OUR FORECAST BE OPTIMISTIC IN SPOTS. SCHULTZ
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
THURSDAY WILL BE MILD BEHIND A PACIFIC FRONTAL PASSAGE...WITH
FAIRLY STRONG WEST WINDS ALONG OUR FOOTHILLS ESPECIALLY IN THE
MORNING. OUR WEST AND CENTRAL PARTS SHOULD BE WELL-MIXED AND SEE
TEMPS RISE INTO THE 50S...BUT LATEST MODEL RUNS SUGGEST THE SFC
TROF MAY NOT PUSH ALL THE WAY TO THE DAKOTAS...KEEPING PLACES LIKE
BAKER AND EKALAKA COLDER THAN THE REST OF THE CWA. WILL NEED TO
KEEP AN EYE ON THE WINDS AS THE USUAL FOOTHILL LOCATIONS SHOULD
SEE GUSTS TO 50 MPH.
CONFIDENCE CONTINUES TO INCREASE IN A SURGE OF COLD CANADIAN AIR
BY THE END OF THE WEEK. COLD ADVECTION WILL ACTUALLY BEGIN
FRIDAY...IE MAYBE A COMBINATION OF RAIN AND SNOW SHOWERS ON THIS
DAY WITH SHORTWAVE ENERGY FROM THE NW. INTERESTING FACET OF THIS
HIGHLY AMPLIFYING FLOW IS THE POSITIVELY TILTED NATURE OF THE TROF
AS IT PUSHES TOWARD THE NORTHERN GREAT BASIN...WITH STRONG UPPER
RIDGING OFF THE PAC COAST INTO BRITISH COLUMBIA. THIS SHOULD ALLOW
FOR STRONG CANADIAN SFC RIDGING OVER EASTERN MT...WHICH ALL MODELS
SHOW HAPPENING...WITH PRESSURES TO NEAR 1050MB OVER NORTH DAKOTA
BY 12Z SUNDAY PER THE GFS ENSEMBLE MEAN. AS A RESULT WE ARE
LOOKING AT A COUPLE OF FAIRLY COLD DAYS SATURDAY AND SUNDAY.
MODELS STILL DIFFER IN MAGNITUDE OF COLD...SOME SUGGEST 850MB
TEMPS NEAR -20C BY EARLY SUNDAY...WHICH WOULD BE THE COLDEST WE
HAVE SEEN IN QUITE SOME TIME. MAIN FORECAST ADJUSTMENTS WERE TO
RAISE POPS FOR WHAT WILL BE SNOWFALL FRIDAY NIGHT AND SATURDAY...
THIS IS THE TIME OF GREATEST BAROCLINICITY...AND TO LOWER TEMPS
SEVERAL DEGREES SATURDAY AND SUNDAY. IT DOES APPEAR WE WILL SEE
DRYING BY SUNDAY AS THE TROF PUSHES SOUTH OF US...AND CONSENSUS IS
FOR KLONDIKE CHINOOKING BY LATE SUNDAY OR SUNDAY NIGHT.
ACTIVE NORTHERLY FLOW WILL CONTINUE INTO NEXT WEEK AS MORE ENERGY
MOVES INTO OUR AREA BY MONDAY. WILL ADD CLIMO POPS WITH A MODEST
WARMING TREND EARLY NEXT WEEK.
JKL
&&
.AVIATION...
SNOW SHOWERS WILL CONTINUE THIS MORNING IN CENTRAL PARTS OF OUR
FORECAST AREA...IMPACTING KBIL AND KSHR. THESE SNOW SHOWERS WILL
PRODUCE LOCALIZED MVFR TO IFR CONDITIONS...AND WILL TAPER OFF
GRADUALLY THIS AFTERNOON AND EVENING. LOCAL MVFR CIGS WILL ALSO
IMPACT EASTERN AREAS NEAR KMLS AND KBHK EARLY THIS MORNING. VFR
FLIGHT CONDITIONS WILL BECOME DOMINANT ACROSS THE AREA TONIGHT.
JKL
&&
.PRELIMINARY POINT TEMP/POPS...
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 034 021/048 034/056 033/044 025/031 011/029 019/041
3/J 10/B 01/N 23/O 45/S 21/B 12/W
LVM 039 025/053 036/054 034/045 025/034 012/032 018/042
1/B 00/N 01/N 24/O 45/S 32/S 12/W
HDN 031 018/042 027/053 028/045 023/032 010/028 012/039
5/J 11/E 01/B 23/O 44/S 21/B 12/J
MLS 023 008/030 020/045 025/039 017/028 006/028 014/036
1/N 11/E 11/B 22/S 32/S 21/B 12/J
4BQ 023 010/031 022/048 026/042 020/029 008/024 010/037
2/J 11/E 11/B 22/O 33/S 21/B 12/J
BHK 017 902/024 014/039 024/036 012/023 000/020 008/034
1/N 11/B 12/W 23/S 32/S 11/B 12/J
SHR 028 016/041 025/052 026/044 022/032 010/026 009/038
9/J 20/B 00/B 23/O 45/S 32/S 12/J
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL NOON MST TODAY FOR
ZONES 38-57-58.
WY...WINTER WEATHER ADVISORY IN EFFECT UNTIL NOON MST TODAY FOR
ZONES 98-99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
935 AM CST TUE FEB 17 2015
.UPDATE...
ONLY RETURNS LEFT ON RADAR AT 930AM WERE LOCATED OVER
KARNES...DEWITT...AND LAVACA COUNTIES AND ON ITS WAY OUT. FOR THE
REST OF THE DAY...NOT EXPECTING ANY OTHER PRECIP AND CLOUDS WILL
BE ON THE DECREASE.
PERFORMED THE TYPICAL OBS BLEND INTO FORECAST HOURLIES AS WELL AS
REMOVING POPS FROM THE GRIDS FOR THE REMAINDER OF THE MORNING.
TB3
&&
.PREV DISCUSSION... /ISSUED 550 AM CST TUE FEB 17 2015/
AVIATION... /12Z TAF UPDATE/
AREAS OF LIGHT RAIN MIXED WITH SLEET AND SNOW CONTINUE TRACKING
EAST FROM THE EDWARDS PLATEAU INTO THE HILL COUNTRY AND CENTRAL
TX. A FEW SNOW AND SLEET REPORTS ARE BEGINNING TO TRICKLE IN OVER
THE NORTHERN HILL COUNTRY...AND THE RADAR ECHOES AND MODEL
SOUNDING DATA LOOK FAVORABLE FOR SOME OF THIS ACTIVITY TO REACH
THE AUS VCNTY FOR A FEW HOURS. MIXED PRECIP LOOKS LESS CERTAIN FOR
SAT/SSF/DRT...AND WILL HANDLE THESE AREAS SHOULD RADAR ECHOES
STRENGTHEN SOUTHWARD. MOST OF THE CIGS ARE HOLDING IN THE VFR
CATEGORY...AND RADAR TRENDS CONTINUE ON A SLOW DECREASE. THUS WILL
KEEP VFR SKIES OVER THE AREA TAF SITES. SOME ADDED GUSTS PICKED UP
THIS MORNING ALONG I-35 WHERE A SLIGHT TIGHTENING OF THE PRESSURE
GRADIENT WAS NOTED. BY 18Z...PRECIP SHOULD BE OUT OF THE TAF
LOCATIONS...AND CLOUDS AND WINDS SHOULD BOTH BE TRENDING
DOWNWARD...AND MOSTLY CLEAR SKIES WITH LIGHT WINDS ARE EXPECTED
TONIGHT.
PREV DISCUSSION... /ISSUED 330 AM CST TUE FEB 17 2015/
SHORT TERM (TODAY THROUGH WEDNESDAY)...FINAL PIECE OF MID LEVEL
FORCING IN THE BASE OF THE TROUGH WILL ROTATE THROUGH THE CWA THIS
MORNING. HAVE FOLLOWED SLIGHTLY CLOSER TO THE HRRR THROUGH MIDDAY
GIVEN THE BETTER HANDLING OF WHERE PRECIP IS CURRENTLY FALLING
ACROSS SOUTHERN AREAS OF SJT AND MAF CWAS. THAT SAID...THERE IS A
SIGNIFICANT DRY LAYER BELOW 800MB ACROSS NORTHERN AND EASTERN
AREAS OF THE CWA...WHICH MAY PREVENT MUCH OF THE PRECIP FROM REACHING
THE GROUND (ESPECIALLY NORTH OF A LLANO TO AUSTIN TO SCHULLENBURG
LINE). WHERE PRECIP DOES REACH THE GROUND...COLUMN WILL BE COOL
ENOUGH ALONG AND WEST OF I-35 FOR LIGHT SLEET OR SNOW FLURRIES TO
MIX IN...ESPECIALLY ACROSS CENTRAL AND WESTERN HILL COUNTRY. THERE
WAS SOME -SN REPORTED EARLIER IN OZONA. GROUND TEMPERATURES FOR
MOST LOCATIONS WILL REMAIN ABOVE FREEZING AND THEREFORE GENERALLY
NO ACCUMULATION IS EXPECTED. HOWEVER...CAN NOT RULE OUT SOME VERY
PATCHY...ELEVATED SURFACES ACROSS THE NORTHERN HILL COUNTRY SEEING
SOME VERY LIGHT ACCUMULATIONS. OVERALL...NOT ENOUGH TO WARRANT AN
ADVISORY...BUT WILL ISSUE AN SPS.
CLEARING WILL TAKE PLACE WEST TO EAST THIS AFTERNOON AND EVENING.
CLEAR SKIES AND LIGHT WINDS...WITH LOW LEVEL RIDGE AXIS OVER THE
CWA...WILL LEAD TO A COLD NIGHT. LOWS WEDNESDAY MORNING DIP INTO
THE MID AND UPPER 20S ACROSS THE HILL COUNTRY AND LOW TO MID 30S
ELSEWHERE. HIGHS REBOUND INTO THE MID 60S UNDER SUNNY SKIES
WEDNESDAY.
JR
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...A WARMING TREND WILL
OCCUR THURSDAY THROUGH SATURDAY ACROSS THE CWA...WITH TEMPERATURES
BACK ABOVE NORMAL FRIDAY AND SATURDAY. LOW LEVEL RETURN FLOW WILL
DEVELOP OVER THE AREA ON THURSDAY...WITH A RETURN OF CLOUDS
THURSDAY NIGHT. PATCHY DRIZZLE AND ISOLATED SHOWERS POSSIBLE
MAINLY ALONG AND EAST OF I-35 FRIDAY AND SATURDAY. ECMWF AND GFS
IN GENERAL AGREEMENT WITH THE NEXT COLD FRONT MOVING THROUGH
SOUTH-CENTRAL TEXAS SUNDAY MORNING. ISENTROPIC UPGLIDE PATTERN
DEVELOPS OVER THE SHALLOW...COLD AIRMASS LEADING TO CLOUDY AND MUCH
COLDER CONDITIONS SUNDAY AND MONDAY ALONG WITH CHANCES FOR RAIN.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 51 35 65 40 71 / 20 0 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 49 29 64 35 69 / 20 0 0 0 0
NEW BRAUNFELS MUNI AIRPORT 50 32 66 38 72 / 20 0 0 0 0
BURNET MUNI AIRPORT 49 32 62 37 68 / 20 0 0 0 0
DEL RIO INTL AIRPORT 53 35 67 43 72 / 20 0 0 0 0
GEORGETOWN MUNI AIRPORT 51 31 64 37 68 / 20 0 0 0 0
HONDO MUNI AIRPORT 53 30 65 37 73 / 30 0 0 0 0
SAN MARCOS MUNI AIRPORT 51 31 65 37 71 / 20 0 0 0 0
LA GRANGE - FAYETTE REGIONAL 51 33 65 38 71 / 20 0 0 0 0
SAN ANTONIO INTL AIRPORT 52 33 65 40 71 / 30 0 0 0 0
STINSON MUNI AIRPORT 53 33 65 39 72 / 30 0 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...24
SYNOPTIC/GRIDS...03
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
626 AM CST TUE FEB 17 2015
.UPDATE...
DWINDLING SNOW ON RADAR THOUGH WITH LIGHT BANDS STILL TO FOLLOW
SEEMS IN LINE WITH LATEST RAP RUN. ALLOWED WINTER WEATHER ADVISORY
TO EXPIRE SOUTHWESTERN SOUTH PLAINS...DO NOT ANTICIPATE MORE THAN
A DUSTING REMAINDER OF THE AREA WITH SNOW MOSTLY ENDING BY 15Z.
RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 537 AM CST TUE FEB 17 2015/
AVIATION...
LIGHT SNOW WILL DWINDLE OVER THE NEXT COUPLE HOURS ACROSS THE SOUTHERN
SOUTH PLAINS INCLUDING KLBB WITH MVFR DOMINATING THROUGH 13Z OR 14Z.
BOTH KPVW AND KCDS APPEAR TOO DISTANT FROM THE BULK OF LIFT AND
DEEPER MOISTURE TO MENTION LINGERING SNOW CHANCES. DOWNSLOPE DRYING
WILL INCREASE MID TO LATE MORNING THOUGH STILL JUST ENOUGH MOISTURE
PERHAPS FOR A CUMULUS FIELD CONNECTED WITH MID LEVEL COOL POCKET
PASSING OVERHEAD. DRY AND VFR OVERNIGHT. RMCQUEEN
PREV DISCUSSION... /ISSUED 320 AM CST TUE FEB 17 2015/
SHORT TERM...
UPPER LEVEL IMPULSE TRANSLATING THROUGH THE AREA THIS MORNING RIGHT
ON SCHEDULE...AND DIRECTED MORE TOWARDS SOUTHERN ZONES WITH LIFT AND
SLIGHTLY DEEPER MOISTURE. THE MID LEVEL LIFT OVERNIGHT SO FAR HAS
SUCCEEDED IN MODEST TOP-DOWN MOISTENING AND SURFACE DEW-POINTS LATELY
HAVE RISEN OVER SOUTHERN ZONES AT LEAST TO THE POINT WHERE LIGHT
SNOW OR SNOW SHOWERS COULD REACH THE GROUND OVER A LARGER AREA. WITH
THAT...HOWEVER...THE RECENT RAP TRENDS SUPPORT ONLY A BRIEF
OPPORTUNITY FOR MOSTLY INSIGNIFICANT ACCUMULATIONS ACROSS MAINLY THE
SOUTHWESTERN SOUTH PLAINS OVER THE NEXT SEVERAL HOURS. THE
PREVIOUSLY ISSUED WINTER WEATHER ADVISORY IN THE SOUTHWESTERN SOUTH
PLAINS STILL SEEMS MORE THAN ADEQUATE BARRING UNEXPECTED LIFT
FURTHER NORTH OR EAST AND LIKELY WILL EXPIRE AT 12Z IF NOT EARLIER.
REMAINING LIGHT SNOW OR SNOW SHOWERS SHOULD FADE AROUND MID MORNING.
IN SPITE OF DRYING TRENDS ON BACK SIDE OF THIS WAVE...SHORT TERM
WRF/NAM CONTINUES TO INDICATE A WEAK CONVECTIVE SIGNAL AROUND MID
DAY INTO AT LEAST EARLY AFTERNOON AND WE HAVE RETAINED LIGHT RAIN
SHOWER POSSIBILITY THIS AREA. FURTHER DRYING AND CLEARING WILL OCCUR
LATER TODAY AND OVERNIGHT. MINOR CHANGES REMAINDER OF FORECAST.
RMCQUEEN
LONG TERM...
MEDIUM RANGE MODELS ARE BEGINNING TO SHOW A GLIMMER OF HOPE DEPICTING
A LITTLE MORE CONSISTENCY FOR THIS WEEKEND INTO EARLY NEXT WEEK.
BEFORE THEN...SURFACE LEE TROUGHING WILL RETURN ON THURSDAY AND
FRIDAY BUMPING TEMPERATURES BACK WELL ABOVE SEASONAL AVERAGES AS
PREVIOUSLY SEEN THIS WINTER SEASON ON THESE TYPES OF DAYS. A STRONG
COLD FRONT WILL MAKE ITS WAY INTO THE AREA ON SATURDAY AHEAD OF A
SURFACE RIDGE SPILLING INTO THE PLAINS AND MIDWEST YET AGAIN. MODELS
SHOW COLD 850MB TEMPERATURES BETWEEN -6 AND -9C BY MONDAY MORNING.
BOTH THE GFS AND ECMWF HAVE BEEN SHOWING VERY LIGHT QPF AMOUNTS ON
SUNDAY AND MONDAY NEXT WEEK. MOST OF THIS ACTIVITY IS DICTATED BY
ISENTROPIC LIFT WITH NEARLY ZONAL FLOW ALOFT. THESE TYPES OF
PATTERNS WHICH ARE DOMINATED BY UPGLIDE TEND TO BE VERY LIGHT IN
PRECIPITATION AMOUNTS AND ARE USUALLY DEFINED BY DRIZZLE. WITH THE
COLD AIR IN PLACE WE COULD SEE A WINTRY MIX OF FZRA/FZDZ EARLY NEXT
WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 44 22 55 29 / 20 0 0 0
TULIA 45 24 55 29 / 20 0 0 0
PLAINVIEW 47 25 56 30 / 20 0 0 0
LEVELLAND 47 26 61 31 / 30 0 0 0
LUBBOCK 48 26 60 31 / 20 0 0 0
DENVER CITY 47 27 62 31 / 30 0 0 0
BROWNFIELD 46 26 61 32 / 30 0 0 0
CHILDRESS 53 25 56 29 / 20 0 0 0
SPUR 50 28 60 32 / 20 0 0 0
ASPERMONT 52 28 62 33 / 20 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/99
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
612 AM CST TUE FEB 17 2015
.DISCUSSION...
12Z TAF DISCUSSION IN AVIATION SECTION...
&&
.AVIATION...
WATCHING A SHORT WAVE TROUGH ON WATER VAPOR IMAGERY OVER C TX
WHICH SHOULD MOVE EAST DURING THE DAY TODAY. PRECIP WITH THIS WAVE
SHOULD STAY NORTH OF MOST OF THE TERMINALS BUT STILL A SMALL
CHANCE OF A FEW SHOWERS. WILL LEAVE OUT MENTION OF PRECIP FOR NOW
AS ANY PRECIP WILL BE SHORT LIVED. COLD ADVECTION SHOULD BE STRONG
ENOUGH TO SLOWLY ERODE MVFR CIGS THIS MORNING AS THE WAVE PULLS
EAST OF THE AREA. THINK CIGS BECOME VFR 16-18Z WITH SKIES CLEARING
THROUGH THE AFTERNOON. HIGH PRESSURE BUILDING THROUGH TEXAS WILL
SUPPORT LIGHT WINDS AND CLEAR SKIES TONIGHT.
39
&&
.PREV DISCUSSION... /ISSUED 327 AM CST TUE FEB 17 2015/
DISCUSSION...
RAIN FROM EARLIER THIS MORNING HAS PUSHED OFF THE COAST LEAVING
CLOUDY AND COLD CONDITIONS IN ITS WAKE. THERE IS CURRENTLY SOME
VERY LIGHT SNOW BEING REPORTED IN THE TEXAS HILL COUNTRY THAT IS
SLOWLY FALLING APART AS IT PUSHES TO THE EAST. THE HRRR HAS BEEN
THE MODEL OF CHOICE THIS MORNING AND HAS SOME VERY LIGHT
REFLECTIVITY MAKING IT INTO THE AREA JUST AFTER SUNRISE THIS
MORNING. ANY PRECIP WILL BE FIGHTING VERY DRY AIR THOUGH BETWEEN
700 AND 850 MB. IF SOME PRECIP DOES REACH THE GROUND IT WILL
PROBABLY HIT THE GROUND AS SLEET. WE WILL CONTINUE TO WATCH THE
LIGHT PRECIP OUT WEST AND MAKE ADJUSTMENTS TO THE FORECAST AS
NEEDED.
AFTER THE PRECIP EXITS THE AREA THIS MORNING SKIES WILL BEGIN TO
GRADUALLY CLEAR FROM WEST TO EAST THIS AFTERNOON AS DRIER AIR
WORKS IN FROM THE NORTH. WEDNESDAY MORNING STILL LOOKS COLD AS
SURFACE HIGH PRESSURE MOVES OVERHEAD. DURING THE DAY WEDNESDAY THE
WARMING TREND WILL START AS SURFACE HIGH PRESSURE BEGINS TO PUSH
EAST. THE CHANCE OF RAIN THEN RETURNS TO THE FORECAST STARTING
FRIDAY AFTERNOON AHEAD OF THE NEXT UPPER LEVEL SYSTEM DIVING SOUTH
OVER THE WEST COAST. MODELS HAVE STRUGGLED WITH THIS DISTURBANCE
THE LAST COUPLE OF DAYS BUT SEEM TO BE CONVERGING ON A SOLUTION.
THE GFS... ECMWF... AND CMC ALL DIVE THE ENERGY SOUTHWARDS AND
FORM A CUT OFF LOW NEAR THE NEVADA/ CALIFORNIA BORDER. STILL
THERE REMAINS DIFFERENCES IN THE COLD FRONT TIMING FOR SUNDAY WITH
THE EURO BEING THE FASTEST AND THE GFS BEING SLIGHT SLOWER. FOR
NOW HAVE TRENDED TOWARDS THE EURO WHICH BRINGS THE FRONT THROUGH
SUNDAY MORNING. ISENTROPIC UPGLIDE THEN LOOKS TO COMMENCE ALLOWING
THE CHANCE OF RAIN TO REMAIN IN THE FORECAST THROUGH THE BEGINNING
OF THE NEXT WORK WEEK. 23
MARINE...
STRONG COLD FRONT HAS PUSHED INTO THE GULF WITH STRONG NORTHERLY
WINDS BEHIND IT THIS MORNING. WINDS SHOULD BE DECREASING THROUGH THE
MORNING AND WILL KEEP A SCA FOR THE OFFSHORE WATERS OF THE UPPER TX
COAST. SCEC WILL BE IN EFFECT FOR THE NEAR SHORE WATERS AND BAYS.
HIGH PRESSURE BUILDS OVER THE REGION TONIGHT INTO WED ALLOWING FOR
LIGHT WINDS AND LOW SEAS.
MODELS STILL SHOW STRONG SE WINDS DEVELOPING THUR AND PERSISTING
THROUGH SATURDAY. LONG SOUTHERLY FETCH SHOULD BUILD SEAS TO NEAR 6FT
NEAR SHORE AND 9-10FT OFFSHORE SO SCA WILL BE LIKELY. COLD FRONT
SHOULD PUSH OFF THE COAST DURING THE DAY SUNDAY AND TURN WINDS TO
THE N/NE. SCA WILL LIKELY BE NEEDED AGAIN BUT FOR OFFSHORE WINDS.
ECMWF SHOWING THE FRONT COULD PUSH THROUGH SUN MORNING INSTEAD OF
LATER IN THE DAY. FORECAST WAS TRENDED IN THIS DIRECTION.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 48 35 63 38 64 / 20 0 0 0 0
HOUSTON (IAH) 49 34 64 38 64 / 20 0 0 0 0
GALVESTON (GLS) 49 42 61 47 62 / 20 0 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 9 AM CST THIS MORNING
FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20
NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 9 AM CST THIS MORNING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...23
AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
550 AM CST TUE FEB 17 2015
.AVIATION... /12Z TAF UPDATE/
AREAS OF LIGHT RAIN MIXED WITH SLEET AND SNOW CONTINUE TRACKING
EAST FROM THE EDWARDS PLATEAU INTO THE HILL COUNTRY AND CENTRAL
TX. A FEW SNOW AND SLEET REPORTS ARE BEGINNING TO TRICKLE IN OVER
THE NORTHERN HILL COUNTRY...AND THE RADAR ECHOES AND MODEL
SOUNDING DATA LOOK FAVORABLE FOR SOME OF THIS ACTIVITY TO REACH
THE AUS VCNTY FOR A FEW HOURS. MIXED PRECIP LOOKS LESS CERTAIN FOR
SAT/SSF/DRT...AND WILL HANDLE THESE AREAS SHOULD RADAR ECHOES
STRENGTHEN SOUTHWARD. MOST OF THE CIGS ARE HOLDING IN THE VFR
CATEGORY...AND RADAR TRENDS CONTINUE ON A SLOW DECREASE. THUS WILL
KEEP VFR SKIES OVER THE AREA TAF SITES. SOME ADDED GUSTS PICKED UP
THIS MORNING ALONG I-35 WHERE A SLIGHT TIGHTENING OF THE PRESSURE
GRADIENT WAS NOTED. BY 18Z...PRECIP SHOULD BE OUT OF THE TAF
LOCATIONS...AND CLOUDS AND WINDS SHOULD BOTH BE TRENDING
DOWNWARD...AND MOSTLY CLEAR SKIES WITH LIGHT WINDS ARE EXPECTED
TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 330 AM CST TUE FEB 17 2015/
SHORT TERM (TODAY THROUGH WEDNESDAY)...FINAL PIECE OF MID LEVEL
FORCING IN THE BASE OF THE TROUGH WILL ROTATE THROUGH THE CWA THIS
MORNING. HAVE FOLLOWED SLIGHTLY CLOSER TO THE HRRR THROUGH MIDDAY
GIVEN THE BETTER HANDLING OF WHERE PRECIP IS CURRENTLY FALLING
ACROSS SOUTHERN AREAS OF SJT AND MAF CWAS. THAT SAID...THERE IS A
SIGNIFICANT DRY LAYER BELOW 800MB ACROSS NORTHERN AND EASTERN
AREAS OF THE CWA...WHICH MAY PREVENT MUCH OF THE PRECIP FROM REACHING
THE GROUND (ESPECIALLY NORTH OF A LLANO TO AUSTIN TO SCHULLENBURG
LINE). WHERE PRECIP DOES REACH THE GROUND...COLUMN WILL BE COOL
ENOUGH ALONG AND WEST OF I-35 FOR LIGHT SLEET OR SNOW FLURRIES TO
MIX IN...ESPECIALLY ACROSS CENTRAL AND WESTERN HILL COUNTRY. THERE
WAS SOME -SN REPORTED EARLIER IN OZONA. GROUND TEMPERATURES FOR
MOST LOCATIONS WILL REMAIN ABOVE FREEZING AND THEREFORE GENERALLY
NO ACCUMULATION IS EXPECTED. HOWEVER...CAN NOT RULE OUT SOME VERY
PATCHY...ELEVATED SURFACES ACROSS THE NORTHERN HILL COUNTRY SEEING
SOME VERY LIGHT ACCUMULATIONS. OVERALL...NOT ENOUGH TO WARRANT AN
ADVISORY...BUT WILL ISSUE AN SPS.
CLEARING WILL TAKE PLACE WEST TO EAST THIS AFTERNOON AND EVENING.
CLEAR SKIES AND LIGHT WINDS...WITH LOW LEVEL RIDGE AXIS OVER THE
CWA...WILL LEAD TO A COLD NIGHT. LOWS WEDNESDAY MORNING DIP INTO
THE MID AND UPPER 20S ACROSS THE HILL COUNTRY AND LOW TO MID 30S
ELSEWHERE. HIGHS REBOUND INTO THE MID 60S UNDER SUNNY SKIES
WEDNESDAY.
JR
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...A WARMING TREND WILL
OCCUR THURSDAY THROUGH SATURDAY ACROSS THE CWA...WITH TEMPERATURES
BACK ABOVE NORMAL FRIDAY AND SATURDAY. LOW LEVEL RETURN FLOW WILL
DEVELOP OVER THE AREA ON THURSDAY...WITH A RETURN OF CLOUDS
THURSDAY NIGHT. PATCHY DRIZZLE AND ISOLATED SHOWERS POSSIBLE
MAINLY ALONG AND EAST OF I-35 FRIDAY AND SATURDAY. ECMWF AND GFS
IN GENERAL AGREEMENT WITH THE NEXT COLD FRONT MOVING THROUGH
SOUTH-CENTRAL TEXAS SUNDAY MORNING. ISENTROPIC UPGLIDE PATTERN
DEVELOPS OVER THE SHALLOW...COLD AIRMASS LEADING TO CLOUDY AND MUCH
COLDER CONDITIONS SUNDAY AND MONDAY ALONG WITH CHANCES FOR RAIN.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 51 35 65 40 71 / 20 0 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 49 29 64 35 69 / 20 0 0 0 0
NEW BRAUNFELS MUNI AIRPORT 50 32 66 38 72 / 20 0 0 0 0
BURNET MUNI AIRPORT 49 32 62 37 68 / 20 0 0 0 0
DEL RIO INTL AIRPORT 53 35 67 43 72 / 20 0 0 0 0
GEORGETOWN MUNI AIRPORT 51 31 64 37 68 / 20 0 0 0 0
HONDO MUNI AIRPORT 53 30 65 37 73 / 30 0 0 0 0
SAN MARCOS MUNI AIRPORT 51 31 65 37 71 / 20 0 0 0 0
LA GRANGE - FAYETTE REGIONAL 51 33 65 38 71 / 20 0 0 0 0
SAN ANTONIO INTL AIRPORT 52 33 65 40 71 / 30 0 0 0 0
STINSON MUNI AIRPORT 53 33 65 39 72 / 30 0 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...18
SYNOPTIC/GRIDS...76
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
537 AM CST TUE FEB 17 2015
.AVIATION...
LIGHT SNOW WILL DWINDLE OVER THE NEXT COUPLE HOURS ACROSS THE SOUTHERN
SOUTH PLAINS INCLUDING KLBB WITH MVFR DOMINATING THROUGH 13Z OR 14Z.
BOTH KPVW AND KCDS APPEAR TOO DISTANT FROM THE BULK OF LIFT AND
DEEPER MOISTURE TO MENTION LINGERING SNOW CHANCES. DOWNSLOPE DRYING
WILL INCREASE MID TO LATE MORNING THOUGH STILL JUST ENOUGH MOISTURE
PERHAPS FOR A CUMULUS FIELD CONNECTED WITH MID LEVEL COOL POCKET
PASSING OVERHEAD. DRY AND VFR OVERNIGHT. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 320 AM CST TUE FEB 17 2015/
SHORT TERM...
UPPER LEVEL IMPULSE TRANSLATING THROUGH THE AREA THIS MORNING RIGHT
ON SCHEDULE...AND DIRECTED MORE TOWARDS SOUTHERN ZONES WITH LIFT AND
SLIGHTLY DEEPER MOISTURE. THE MID LEVEL LIFT OVERNIGHT SO FAR HAS
SUCCEEDED IN MODEST TOP-DOWN MOISTENING AND SURFACE DEW-POINTS LATELY
HAVE RISEN OVER SOUTHERN ZONES AT LEAST TO THE POINT WHERE LIGHT
SNOW OR SNOW SHOWERS COULD REACH THE GROUND OVER A LARGER AREA. WITH
THAT...HOWEVER...THE RECENT RAP TRENDS SUPPORT ONLY A BRIEF
OPPORTUNITY FOR MOSTLY INSIGNIFICANT ACCUMULATIONS ACROSS MAINLY THE
SOUTHWESTERN SOUTH PLAINS OVER THE NEXT SEVERAL HOURS. THE
PREVIOUSLY ISSUED WINTER WEATHER ADVISORY IN THE SOUTHWESTERN SOUTH
PLAINS STILL SEEMS MORE THAN ADEQUATE BARRING UNEXPECTED LIFT
FURTHER NORTH OR EAST AND LIKELY WILL EXPIRE AT 12Z IF NOT EARLIER.
REMAINING LIGHT SNOW OR SNOW SHOWERS SHOULD FADE AROUND MID MORNING.
IN SPITE OF DRYING TRENDS ON BACK SIDE OF THIS WAVE...SHORT TERM
WRF/NAM CONTINUES TO INDICATE A WEAK CONVECTIVE SIGNAL AROUND MID
DAY INTO AT LEAST EARLY AFTERNOON AND WE HAVE RETAINED LIGHT RAIN
SHOWER POSSIBILITY THIS AREA. FURTHER DRYING AND CLEARING WILL OCCUR
LATER TODAY AND OVERNIGHT. MINOR CHANGES REMAINDER OF FORECAST.
RMCQUEEN
LONG TERM...
MEDIUM RANGE MODELS ARE BEGINNING TO SHOW A GLIMMER OF HOPE DEPICTING
A LITTLE MORE CONSISTENCY FOR THIS WEEKEND INTO EARLY NEXT WEEK.
BEFORE THEN...SURFACE LEE TROUGHING WILL RETURN ON THURSDAY AND
FRIDAY BUMPING TEMPERATURES BACK WELL ABOVE SEASONAL AVERAGES AS
PREVIOUSLY SEEN THIS WINTER SEASON ON THESE TYPES OF DAYS. A STRONG
COLD FRONT WILL MAKE ITS WAY INTO THE AREA ON SATURDAY AHEAD OF A
SURFACE RIDGE SPILLING INTO THE PLAINS AND MIDWEST YET AGAIN. MODELS
SHOW COLD 850MB TEMPERATURES BETWEEN -6 AND -9C BY MONDAY MORNING.
BOTH THE GFS AND ECMWF HAVE BEEN SHOWING VERY LIGHT QPF AMOUNTS ON
SUNDAY AND MONDAY NEXT WEEK. MOST OF THIS ACTIVITY IS DICTATED BY
ISENTROPIC LIFT WITH NEARLY ZONAL FLOW ALOFT. THESE TYPES OF
PATTERNS WHICH ARE DOMINATED BY UPGLIDE TEND TO BE VERY LIGHT IN
PRECIPITATION AMOUNTS AND ARE USUALLY DEFINED BY DRIZZLE. WITH THE
COLD AIR IN PLACE WE COULD SEE A WINTRY MIX OF FZRA/FZDZ EARLY NEXT
WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 44 22 55 29 / 20 0 0 0
TULIA 45 24 55 29 / 20 0 0 0
PLAINVIEW 47 25 56 30 / 20 0 0 0
LEVELLAND 47 26 61 31 / 30 0 0 0
LUBBOCK 48 26 60 31 / 20 0 0 0
DENVER CITY 47 27 62 31 / 30 0 0 0
BROWNFIELD 46 26 61 32 / 30 0 0 0
CHILDRESS 53 25 56 29 / 20 0 0 0
SPUR 50 28 60 32 / 20 0 0 0
ASPERMONT 52 28 62 33 / 20 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
TXZ039-040.
&&
$$
99/99/05
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
426 AM MST TUE FEB 17 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 200 AM MST TUE FEB 17 2015
THE MAIN FORECAST CONCERN OVER THE SHORT TERM WILL PRIMARILY BE IN
THE FIRST 24 HOURS DUE TO LOCALLY HEAVY SNOW SHOWERS MOVING SOUTH
ACROSS THE AREA EARLY THIS MORNING. THE NEXT WEAK UPPER LEVEL
SHORTWAVE IS NOW PUSHING INTO EASTERN WYOMING AND THE WESTERN
DAKOTAS AS A STRONG 150KT JET MAX MOVES SOUTHWARD INTO THE HIGH
PLAINS. LOW TO MIDLEVEL INSTABILITY DUE TO STEEP LAPSE RATES
BETWEEN 800MB TO 600MB WILL SUPPORT BANDED SNOWFALL THROUGH TODAY
AS ALREADY SEEN ON CURRENT KCYS RADAR LOOP. RADAR SHOWS A BAND OF
LOCALLY HEAVY SNOWFALL STRETCHING FROM DOUGLAS SOUTHEAST TOWARDS
THE CHEYENNE RIDGE SOUTH OF TORRINGTON...WHICH IS A BIT FURTHER
SOUTH THAN EXPECTED. THANKFULLY...THESE SHOWERS CONTAIN
RELATIVELY NARROW BANDS OF LOCALLY HEAVY SNOWFALL AND ARE MOVING
RATHER QUICK ACROSS THE AREA. THAT MAY CHANGE THIS MORNING HOWEVER
AS MODELS SHOW SOME ENHANCED LIFT IN THE VICINITY OF THE BLACK
HILLS AND PORTIONS OF FAR EASTERN WYOMING AND NORTHERN NEBRASKA
PANHANDLE. THIS AREA IS ALSO NEAR THE LEFT EXIT REGION OF THE
JET...SO KEPT POP ON THE HIGH SIDE NORTH OF THE PLATTE RIVER
VALLEY THIS MORNING. HOWEVER...HAVE TO QUESTION WHETHER THE BLACK
HILLS AND THE NORTHERLY WINDS ARE RESULTING IN SOME SNOW SHADOWING
EFFECT ACROSS THE FAR NORTHERN ZONES. EITHER WAY...SNOWFALL
AMOUNTS WILL BE TRICKY DUE TO THE CONVECTIVE BANDING...BUT CAN NOT
RULE OUT A QUICK 1 TO 2 INCHES OF SNOW ACROSS THE HIGH PLAINS.
THIS THREAT WILL SHIFT EAST THROUGH THE DAY AS THE JET AXIS SHIFTS
EASTWARD AS WELL. ON THE WESTERN HALF OF THE JET...DRIER AIR ALOFT
WILL BEGIN TO ENTER THE AREA AND DESCENT DOWN TO NEAR
500MB...GREATLY LOWERING THE POTENTIAL OF WIDESPREAD SNOW SHOWERS
OVER MOST OF SOUTHEAST WYOMING BY LATE THIS AFTERNOON. DUE TO THE
STEEP LAPSE RATES ACROSS THE AREA AND LLVL COLD AIR
ADVECTION...WINDS WILL ALSO BE AN ISSUE. KEPT THE WIND ADVISORY
OUT FOR THE SOUTHERN NE PANHANDLE TODAY FOR SUSTAINED WIND SPEEDS
BETWEEN 30 TO 35 MPH AND GUSTS AROUND 45 MPH. WILL ALSO NEED TO
MONITOR THE POTENTIAL FOR BLOWING SNOW IN AREAS THAT RECEIVED A
FEW INCHES OF SNOW ACCUMULATION DUE TO THE LOCALLY HEAVY SNOWFALL.
HOWEVER...THE AREA MIGHT NOT BE LARGE ENOUGH TO SUPPORT AN
ADVISORY. WILL CONTINUE TO MONITOR WEBCAMS AND REPORTS ACROSS THE
AREA IN THE EVENT AN ADVISORY FOR BLOWING SNOW AND REDUCED
VISIBILITIES IS NEEDED.
BY LATE THIS AFTERNOON AND INTO THIS EVENING...LAPSE RATES WILL
DECREASE FROM WEST TO EAST AS SNOW SHOWERS WILL TAPER TO ISOLATED
FLURRIES ACROSS THE HIGH PLAINS. CLOUDS WILL REMAIN OVER THE AREA
DUE TO THE VIGOROUS JET STREAM AND PLENTIFUL MIDLEVEL MOISTURE.
HOWEVER...DO NOT EXPECT MUCH IN THE WAY OF PRECIP TUESDAY NIGHT
SINCE MODEL SOUNDINGS SHOW A DEEP DRY LAYER ALOFT MOVING INTO THE
AREA.
FOR WEDNESDAY AND THURSDAY...MODELS SHOW THE STRONG RIDGE AXIS
ALONG THE WEST COAST WEAKENING AND FLATTENING OUT AS IT MOVES
EASTWARD INTO THE ROCKY MOUNTAINS...MAINLY DUE TO THE STRENGTH OF
THE ARCTIC AIRMASS IMPACTING THE EASTERN TWO THIRDS OF THE
COUNTRY. TEMPERATURES WILL RETURN TO AROUND NORMAL FOR THIS TIME
OF THE YEAR DUE TO SOME DOWNSLOPE FLOW WITH HIGHS IN THE MID 30S
TO MID 40S...WARMEST OVER THE SOUTHEAST WYOMING HIGH PLAINS AND
THE SOUTHERN NEBRASKA PANHANDLE. THE MID TO UPPER LEVEL FLOW WILL
BACK AND BECOME MORE WESTERLY ON THURSDAY AHEAD OF THE NEXT STORM
SYSTEM...WHICH WILL ALLOW TEMPERATURES TO INCREASE INTO THE UPPER
40S TO UPPER 50S ACROSS MOST OF THE FORECAST AREA. WILL HAVE TO
MONITOR WINDS ACROSS SOUTHEAST WYOMING FOR THURSDAY MORNING.
MODELS DO INDICATE THAT THE WIND PRONE AREAS MAY GET CLOSE TO HIGH
WIND CRITERIA. FOR NOW...INCREASED WINDS BETWEEN 30 TO 40 MPH
SUSTAINED WITH GUSTS AROUND 55 MPH. THE 850 TO 700MB GRADIENT DOES
INCREASE TO AROUND 55 DM DURING THIS TIME PERIOD...AND WILL SEE IF
FUTURE MODEL RUNS CONTINUE TO TREND HIGHER.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 300 AM MST TUE FEB 17 2015
UNSETTLED WEATHER IN THE EXTENDED WITH MOST AREAS SEEING SNOW AT
SOME POINT THROUGH THE WEEKEND.
GOOD AGREEMENT BETWEEN THE GFS AND ECMWF BRINGING NEXT SHORTWAVE
INTO SOUTHEAST WYOMING FRIDAY AFTERNOON. FRONT SAGS TO THE
COLORADO/WYOMING BORDER FRIDAY AFTERNOON WITH WIDESPREAD RAIN
TURNING QUICKLY TO SNOW FRIDAY EVENING.
REALLY NEED TO WATCHING THIS FRONT AS IT STALLS OVER CENTRAL
COLORADO. 60-70 MILES FURTHER NORTH AND SOUTHERN WYOMING COULD BE
IN FOR A MAJOR WINTER EVENT. RIGHT NOW THOUGH...BEST CHANCES LOOK
TO BE FRIDAY NIGHT INTO SATURDAY MORNING. BOTH GFS AND ECMWF IN
AGREEMENT HOLDING ONTO SOME LIGHT QPF OVER OUR SOUTHERN BORDER
THROUGH THE WEEKEND...SO KEPT SOME LOW CHANCE POPS GOING THROUGH
SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 423 AM MST TUE FEB 17 2015
LATEST HRRR GUIDANCE USED FOR THE 12Z TAF SUITE. SHOWING SOME
NBANDS OF SNOW DEVELOPING OUT IN THE PANHANDLE THIS MORNING THAT
COULD PRODUCE SOME TEMPO CONDITIONS. BEST LOCATION LOOKS TO BE
KBFF AND KSNY IN THE SOUTHERN PANHANDLE. WINDS WILL BE ANOTHER
ISSUE TODAY AS MOST AIRPORTS WILL SEE SOME PRETTY STRONG NORTHWEST
WINDS. WINDS SHOULD DECREASE TOWARDS SUNSET TODAY.
&&
.FIRE WEATHER...
ISSUED AT 130 AM MST TUE FEB 17 2015
NO FIRE WEATHER CONCERNS THROUGH THIS WEEK. TEMPERATURES WILL
CONTINUE TO BE BELOW NORMAL THROUGH TUESDAY BEFORE THEY MODERATE
SOME ON WEDNESDAY AND THURSDAY. MINIMUM AFTERNOON HUMIDITY VALUES
WILL BE ABOVE 3O PERCENT. A STRONG COLD FRONT WILL PUSH SOUTHWARD
ACROSS THE AREA BRINGING A MODIFIED ARCTIC AIRMASS IN ADDITION TO
WIDESPREAD SNOWFALL BY NEXT WEEKEND.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...WIND ADVISORY FROM 8 AM THIS MORNING TO 4 PM MST THIS AFTERNOON
FOR NEZ019>021-054-055.
&&
$$
SHORT TERM...TJT
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...TJT
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
337 PM CST TUE FEB 17 2015
.SHORT TERM...
320 PM CST
TONIGHT THROUGH THURSDAY...
MAIN CONCERN IS WITH BITTERLY COLD TEMPERATURES AND WIND CHILLS AS
NEAR RECORD COLD AIR MASS FOR MID TO LATE FEBRUARY IMPACTS THE AREA.
IN ADDITION...EXPECTING FAIRLY WIDESPREAD SNOW SHOWERS LATE TONIGHT
INTO WEDNESDAY MORNING.
MORNING RAOBS SHOWED HEART OF COLD AIR MASS...WITH 850 MB TEMPS OF
ABOUT -25 TO -30C FROM KINL UP TO HUDSON BAY. STRONG PV ANOMALY ON
LEADING EDGE OF THIS AIR MASS IS NOTED ON W/V IMAGERY FROM EASTERN
DAKOKTAS INTO WESTERN ONTARIO AND THIS WILL MOVE OVER THE AREA
TONIGHT INTO EARLY THURSDAY. IN NEAR TERM...WILL CONTINUE TO SEE
OCCASIONAL FLURRIES...WITH LINGERING SNOW SHOWERS EXITING NW
INDIANA. FORCING FROM UPPER WAVE/PV ANOMALY AND STEEPENING OF
LAPSE RATES SHOULD RESULT IN FAIRLY WIDESPREAD SCATTERED SNOW
SHOWERS PIVOTING SOUTHEASTWARD FROM AROUND MIDNIGHT TONIGHT
THROUGH EARLY THURSDAY MORNING. SIMILAR TO PREVIOUS OCCURRENCES
WITHIN THE PAST WEEK...NOT ALL AREAS WILL SEE ACCUMULATIONS...BUT
WOULDNT BE SURPRISED IF HEAVIER SNOW SQUALLS ARE EMBEDDED WITHIN
SCATTERED SNOW SHOWER ACTIVITY...YIELDING LOCALLY 1/2 INCH TO 1
INCH ACCUMS AND SIGNIFICANTLY REDUCED VISIBILITY. COLD ADVECTION
SHOULD FORCE TEMPERATURES DOWN TO ROUGHLY 0 TO +6 RANGE BY
DAYBREAK WEDNESDAY.
TEMPERATURE TRENDS ARE TRICKY ON WEDNESDAY BECAUSE OF HOW ANOMALOUS
AIR MASS IS. MINUS MID TO UPPER 20SC AIRMASS AT 850 MB PROGGED BY
LATE IN THE DAY IS AMONGST THE COLDEST OBSERVED AT ILX/DVN IN THE
MONTH OF FEBRUARY...AND ESPECIALLY THIS LATE IN THE MONTH. HAVE
SHOWN A VERY MINIMAL RECOVERY FROM MORNING LOWS INTO MID DAY/HIGHS
MID TO HIGH POSITIVE SINGLE DIGITS/FOLLOWED BY A FALL IN THE
AFTERNOON..BUT THIS VERY WELL COULD BE OVERDONE. BEST FORCING WILL
BE OFF TO EAST...BUT DEEP UPPER TROUGH REMAINING OVERHEAD AND STEEP
LOW LEVEL LAPSE RATES SHOULD KEEP AT LEAST ISOLATED SNOW SHOWERS AND
FLURRIES AROUND INTO EARLY WEDNESDAY AFTERNOON. STRONG LOW LEVEL
COLD ADVECTION WILL CONTINUE THROUGH WEDNESDAY NIGHT...WITH 925 MB
TEMPS IN THE MID MINUS 20SC BY EARLY THURSDAY. THUS DESPITE HIGH
PRESSURE REMAINING WELL NORTHWEST AND PRECLUDING RADIATIONAL
COOLING...SUBZERO LOWS ARE EXPECTED CWA WIDE...AND RELATIVELY
UNIFORM RANGING FROM MID MINUS SINGLE DIGITS TO AROUND 10 BELOW.
EVEN DOWNTOWN CHICAGO SHOULD FALL TO SEVERAL DEGREES BELOW ZERO.
WILL NEED A WIND CHILL ADVISORY FOR THE ENTIRE CWA WEDNESDAY
EVENING/NIGHT THROUGH THURSDAY MORNING...WITH LOWEST VALUES
RANGING FROM 20 TO 30 BELOW ZERO.
THERMAL TROUGH WILL ONLY SLOWLY DEPART TO THE NORTHEAST ON
THURSDAY...SO AFTER BITTERLY COLD START TO DAY...CONTINUE TO
FORECAST RECORD/NEAR RECORD LOW HIGH TEMPERATURES IN THE LOW TO MID
POSITIVE SINGLE DIGITS. SEE CLIMATE SECTION FOR ADDITIONAL DETAILS.
REGARDING LAKE EFFECT POTENTIAL ON WEDNESDAY INTO WEDNESDAY
NIGHT...GUIDANCE CONTINUES TO FOCUS MAINLY EAST OF PORTER COUNTY
WITH WNW BOUNDARY LAYER FLOW. HOWEVER...WITH EXTREME COLD AIR MASS
OVER RELATIVELY MILD LAKE WATERS...COULD STILL SEE SOME MINOR
ACCUMULATIONS IN NORTHEAST PORTER COUNTY IN LIGHT MULTIBAND SNOW
SHOWERS.
RC
&&
.LONG TERM...
320 PM CST
THURSDAY NIGHT THROUGH TUESDAY...
TO BE ISSUED SHORTLY.
RC
&&
.CLIMATE...
WHILE THE COLDEST AIR ALOFT ARRIVES WEDNESDAY...THE COLDEST SURFACE
TEMPERATURES MAY RESULT ON THURSDAY FEBRUARY 19TH...WHICH RIGHT NOW
APPEARS COULD JEOPARDIZE SOME RECORDS...ESPECIALLY THE LOW MAXS.
FEB 19TH
RECORD LOW RECORD LOW MAX
CHICAGO -7 (1936) 9 (1936)
ROCKFORD -16 (1979) 7 (1959)
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* GUSTY WLY-WNWLY WINDS TO 20 KT THROUGH LATE THIS AFTERNOON.
* OCNL -SHSN THROUGH SUNSET.
* POTENTIAL FOR A SHORT PERIOD OF MODERATE SNOW SHOWERS LATE
TONIGHT WITH PERIODS IFR VIS/MVFR CIGS POSSIBLE.
* GUSTY NWLY WINDS TO 25KT TOMORROW.
KREIN
//DISCUSSION...UPDATED 18Z...
A WEAK COLD FRONT HAS PUSHED THROUGH ALL OF THE TERMINALS...EXCEPT
GYY...AT ISSUANCE TIME. EXPECT THAT THE FRONT SHOULD PUSH PAST GYY
WITHIN THE NEXT HOURS OR SO. FOLLOWING THE FROPA...SCT SNOW
SHOWERS HAVE ENDED AND SKIES ARE IMPROVING TO VFR AND WINDS HAVE
SHIFTED TO GENERALLY NWLY. WITH INCREASED SUNSHINE AND POST FRONTAL
COLD ADVECTION...EXPECT GUSTS TO 20KT THROUGH THE AFTERNOON.
ANOTHER PERIOD OF LIGHT SNOW IS POSSIBLE TONIGHT AS A MID LEVEL
IMPULSE CROSSES THE REGION...AROUND THE SOUTHWESTERN PERIPHERY OF A
BROAD UPPER TROUGH COVERING THE ERN/CNTRL CONUS. SINCE THE AIRMASS
OVER THE REGION IS STILL RELATIVELY DRY...ANTICIPATE ONLY MINOR
ACCUMULATIONS...PERHAPS AROUND 1 INCH...BUT WITH WINDS LIKELY TO
REMAIN ABOVE 10KT THROUGH THE NIGHT...EXPECT THE MAIN IMPACT TO BE
REDUCED VISIBILITY...LIKELY DROPPING INTO IFR LEVELS. GIVEN SOME
UNCERTAINTY TO THE EXACT TIMING OF THE SYSTEM CROSSING THE
AREA...WILL MAINTAIN THE GOING PROB30 GROUP...BUT ANTICIPATE THAT
THIS WILL BE UPGRADED TO A TEMPO OR PREVAILING GROUP AS TIMING
BECOMES MORE CERTAIN. FOLLOWING THE PASSAGE OF AN ASSOCIATED SFC
COLD FRONT...VERY COLD AIR WILL FILTER IN ACROSS THE AREA AS
STRONG HIGH PRESSURE BUILDS OVER THE NRN/CNTRL PLAINS AND A WEAK
SFC LOW PRESSURE MOVES THROUGH THE ERN GREAT LAKES. A MODERATE
PRESSURE GRADIENT AND STRONG COLD ADVECTION WILL LEAD TO GUSTY
NWLY WINDS THOUGH THE DAY TOMORROW...WITH GUSTS TO 25KT OR
POSSIBLY HIGHER.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM TO HIGH CONFIDENCE IN WIND TRENDS THROUGH THE PERIOD.
* MEDIUM TO HIGH CONFIDENCE IN ANOTHER ROUND OF LIGHT SNOW LATE TONIGHT.
* MEDIUM CONFIDENCE IN TIMING AND DURATION OF REDUCED CIGS/VIS
ASSOCIATED WITH THE SNOW.
* LOW TO MEDIUM CONFIDENCE IN HOW LOW CIGS/VIS WILL DROP DURG
PERIODS OF SNOW.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR WITH WEST-NORTHWEST WINDS.
THURSDAY...MAINLY VFR. NORTHWEST WINDS.
FRIDAY...CHANCE OF SNOW. IFR POSSIBLE. GUSTY SOUTH WINDS.
SATURDAY...CHANCE OF SNOW. IFR POSSIBLE. SOUTHWEST WINDS BECOMING
NORTHWEST.
SUNDAY...MAINLY VFR. NORTH-NORTHEAST WINDS.
MONDAY...VFR. WESTERLY WINDS.
KJB
&&
.MARINE...
336 PM CST
WESTERLY WINDS IN PLACE LATE THIS AFTERNOON ARE EXPECTED TO BECOME
MORE NORTHERLY TONIGHT AS LOW PRESSURE DEPARTS TO THE EAST AND
HIGH PRESSURE BUILDS OVER THE CENTRAL PART OF THE US. SPEEDS WILL
ALSO INCREASE TONIGHT AS THE SURFACE GRADIENT TIGHTENS AND HAS
COLDER AIR CONTINUES TO SPILL SOUTH ACROSS THE REGION...WITH WINDS
TO 30 KT LIKELY. INCREASING WINDS WILL CONTINUE ON WEDNESDAY WITH
GALES LIKELY PRIMARILY ON THE SOUTHERN HALF OF THE
LAKE...ALTHOUGH....A SMALL WINDOW OF GALE FORCE GUSTS DO APPEAR
POSSIBLE ACROSS THE NORTH HALF WEDNESDAY AFTERNOON. SO HAVE ISSUED
A GALE WARNING FOR THE SOUTH HALF AS WELL AS A HEAVY FREEZING
SPRAY WARNING FOR WEDNESDAY INTO WEDNESDAY EVENING. NORTHWEST
WINDS WILL SLOWLY DIMINISH WEDNESDAY NIGHT INTO THURSDAY...BUT
WITH WINDS TO 30KT STILL LIKELY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...HEAVY FREEZING SPRAY WARNING...LMZ080-LMZ567-LMZ669-LMZ671-
LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-
LMZ876-LMZ878...6 AM WEDNESDAY TO 9 PM WEDNESDAY.
GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...6 AM
WEDNESDAY TO 9 PM WEDNESDAY.
GALE WARNING...LMZ745...9 AM WEDNESDAY TO 6 PM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744...9 AM
WEDNESDAY TO 6 PM WEDNESDAY.
&&
$$
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
320 PM CST Tue Feb 17 2015
.SHORT TERM...(Tonight)
ISSUED AT 320 PM CST TUE FEB 17 2015
Slightly complicated forecast in the short term as the long wave
trof rotates around and through the region tonight, with a couple
shortwaves on satellite imagery. HRRR and RUC/RAPP both producing
more qpf with prev runs and clearly picking up on some snow showers
out to the west. NAM/GFS picking up on it, but mainly concentrating
on wave to the south. As a result, two additions to tonights
forecast...one with the southwest CWA in a line from roughly
Jacksonville to Springfield to Paris...potential for a few tenths of
snowfall. Up to an inch possible, but better chances will be to the
south, where the second change to the forecast is with the more
southerly wave...an inch/inch and a half are possible. Behind the
snow as morning approaches, the northwesterly winds will continue to
increase. Temperatures will mainly run slightly off the normal
diurnal curve as the cold air mass moves southward into the region.
By early morning hours, wind chills will drop to -10 to -15F NW of
the Illinois River Valley.
&&
.LONG TERM...(Wednesday through Tuesday)
ISSUED AT 320 PM CST TUE FEB 17 2015
Another reinforcing push of cold air will move into central Illinois
behind another pressure trough early Wednesday. Very cold arctic air
will result in highs only in the single digits with brisk northwest
winds 15-20 mph and gusts to around 30 mph. Went below MOS guidance
for highs Wed due to extreme variation from climatology and due to
snow cover over portions of the forecast area. As a result, wind
chill values will be below -15 F for much of the area northwest of
the Illinois River and have issued a wind chill advisory from 5 a.m.
to noon. Wind chill temperatures should be just above wind chill
criteria...-10 F or so for the afternoon, but still very cold. Winds
will settle down somewhat overnight Wednesday night causing
temperatures to drop below zero throughout central IL, but wind
chills look to drop to around -15 to -20 F and may need another wind
chill advisory.
Deep upper level trof shifts east of IL Thu night and Friday while
arctic high pressure also drifts east of IL across the Ohio river
valley Thu night and Fri morning. Temps will be slow to climb on
Friday due to mostly cloudy skies with highs in the low to mid 20s.
Have small chances of light snow Friday afternoon as moist warm
advection affects the region.
Extended models coming to better agreement on track of southern
stream storm system this weekend, with track of low passing the
southern tip of Illinois Saturday. Looks cold enough for mainly
light snow, though continue with a mix over southeast IL on Sat.
Have just slight chance of light snow Sunday and then dry across
area by Sunday evening. Highs in the low to mid 30s Sat cool off
again early next week on Sunday and Monday behind this storm
system.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1148 AM CST TUE FEB 17 2015
Brief clearing behind the boundary this morning and northwesterly
winds setting up across the region. Northwesterly winds will
continue through tomorrow morning becoming brisk and gusty to
25 kts by mid morning. SC are expected to move in associated
with a small wave as well as develop over the FA this afternoon
and bring chance for flurries. More widespread threat for -SN
moving in just before midnight and spreading east into the morning
hours. Skies mainly VFR until the -SN and drop to MVFR between 05z
and 12z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY from 5 AM to Noon CST Wednesday FOR
ILZ027>029-036-040.
&&
$$
SHORT TERM...HJS
LONG TERM...Onton
AVIATION...HJS
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1144 AM CST TUE FEB 17 2015
.UPDATE...
1052 AM CST
SNOW SHOWERS HAVE LINGERED A BIT LONGER THAN EXPECTED OVER
PORTIONS OF NORTHERN IL AND NORTHWEST IN AS FORCING FROM ELONGATED
MIDLEVEL VORT MAX HAS TRANSLATED ACROSS THE AREA. SUPPRESSION ON
BACK SIDE OF WAVE WILL CUT OFF ONGOING SNOW SHOWER ACTIVITY FROM
NORTHWEST TO SOUTHEAST INTO EARLY AFTERNOON...SO HAVE TAILORED LOW
MEASURABLE POPS TO FOLLOW THIS TREND. BASED ON LATEST
RADAR...COULD STILL SEE VISIBILITY BRIEFLY BELOW 1 MILE AT TIMES
IN HEAVIER SNOW SHOWERS...BUT NOT EXPECTING MORE THAN A DUSTING TO
A FEW TENTHS OF AN INCH OF SNOW. ALSO ADJUSTED TEMPS AND DEWPOINTS
A BIT...WITH SLIGHTLY MILDER HIGHS RANGING FROM 20 TO 24 ALONG AND
EAST OF A CHICAGO TO STREATOR LINE. FINALLY...MADE SOME SKY GRID
ADJUSTMENTS TO ACCOUNT FOR CLEARER CONDITIONS IN WESTERN HALF OF
CWA.
THE SNOW SHOWER ACTIVITY THIS MORNING COULD BE A PREVIEW OF LATE
TONIGHT INTO WEDNESDAY MORNING AS A MUCH STRONGER PV ANOMALY
IMPACTS THE AREA. MODELS CONTINUE WITH VERY LOW QPF IN ARCTIC AIR
MASS...BUT EXPECTING POTENTIALLY MORE WIDESPREAD AND HEAVIER SNOW
SHOWERS DUE TO BETTER FORCING FROM STRONGER UPPER WAVE.
UPDATED GRIDS AND ZONES HAVE BEEN SENT.
RC
&&
.SHORT TERM...
301 AM CST
THROUGH WEDNESDAY...
EARLY MORNING WATER VAPOR IMAGERY SHOWS THE AMPLIFYING UPPER FLOW
PATTERN WHICH WILL BRING ANOTHER ROUND OF BITTERLY COLD AIR TO THE
AREA. A LARGE LONGWAVE TROUGH IS SPREAD ACROSS THE EASTERN TWO-
THIRDS OF NORTH AMERICA WHILE SHARP LONGWAVE RIDGING EXTENDS UP
THE WEST COAST. SEVERAL SUBTLE SHORTWAVES ARE EMBEDDED IN THE
NORTHERLY FLOW FROM NORTHERN CANADA TO THE CENTRAL PLAINS. THE
MAIN WAVE OF NOTE IS ONE THAT IS QUICKLY MOVING SOUTHWARD ACROSS
CENTRAL SASKATCHEWAN AND MANITOBA...AND WILL BRING THE PUSH OF
COLDEST AIR TOMORROW. IN THE NEAR TERM...A WAVE DROPPING
SOUTHEASTWARD FROM MINNESOTA WILL CROSS THE AREA EARLY THIS
MORNING. AT THE SURFACE...A COLD FRONT EXTENDS FROM LOW PRESSURE
OVER HUDSON BAY WITH A SECONDARY CIRCULATION OVER THE EASTERN U.P.
OF MICHIGAN. THE FRONT WILL CROSS THE AREA BY MID MORNING TURNING
WINDS NORTHWESTERLY. RADAR MOSAIC SHOWS LIGHT RETURNS ACROSS THE
AREA WHICH ARE PRODUCING SOME FLURRIES AND A LITTLE LIGHT SNOW.
BANDS OF LIGHT SNOW SHOWERS ARE APPROACHING IN CLOSER PROXIMITY TO
THE FRONT AND THE ASSOCIATED UPPER WAVE AND MAY RESULT IN SNOW
INTENSE ENOUGH TO LOWER VSBY TO A FEW MILES THANKS TO STEEP LOW
LEVEL LAPSE RATES ALLOWING FOR A CONVECTIVE COMPONENT. COVERAGE
WILL NOT BE THAT GREAT AND DURATION WILL BE SHORT BUT WILL WORK
LOW POPS THROUGH THE AREA THROUGH MID MORNING. H85 TEMPS FALL TO
-16 TO -20C BY LATE DAY WITH H92 TEMPS FROM -16 TO -18C YIELDING
HIGHS IN THE LOWER TEENS NORTH TO AROUND 20 SOUTH. THERE WILL NOT
BE MUCH IN THE WAY OF LARGE SCALE LIFT BY AFTERNOON WITH THE UPPER
TROUGH EXITING BUT LOW LEVEL LAPSE RATES AND CONTINUED CLOUD
COVER/MOISTURE MAY LEAD TO SOME FLURRY ACTIVITY THANKS TO THE
PRESENCE OF ICE CRYSTALS IN THE STEEP LAPSE RATE ZONE.
THE CENTRAL SASKATCHEWAN/MANITOBA TROUGH WORKS ACROSS THE AREA
TONIGHT. THIS TROUGH SHOULD BRING BETTER LARGE SCALE FORCING WITH IT
BUT ALSO ANOTHER ROUND OF STEEP LAPSE RATES WITH ANOTHER STRONG COLD
FRONT. AM CONCERNED THAT THERE WILL BE A HIGHER COVERAGE OF FAIRLY
INTENSE SNOW SHOWERS THAT ACCOMPANIES THE TROUGH/FRONT PASSAGE LATE
THIS EVENING AND OVERNIGHT. WITH A FAIRLY SHORT DURATION TO ANY
GIVEN SNOW SHOWER ACCUMULATION WOULD BE LIMITED BUT COULD FORESEE
GREATLY REDUCED VSBY IN THE SNOW SHOWERS THAT DO OCCUR WITH A QUICK
ACCUMULATION...NOT UNLIKE SOME OF THE SNOW SQUALLS THAT OCCURRED WITH
A FRONTAL PASSAGE OVER THE WEEKEND. AT THIS POINT OCCURRENCE LOOKS
TO END RIGHT AROUND THE START OF THE WEDNESDAY MORNING RUSH WHICH
ADDS TO THE CONCERN. WILL CONTINUE WITH SLIGHT AND LOW CHANCE POPS
FOR NOW BUT WILL PASS CONCERNS ALONG TO THE DAY SHIFT. STEEP LAPSE
RATES AND CONTINUED COLD ADVECTION MAY RESULT IN PERIODS OF FLURRIES
OR EVEN SOME ADDITIONAL LIGHT SNOW THROUGH MUCH OF WEDNESDAY. LAKE
EFFECT SNOW WILL SKIRT NORTHEAST PORTER COUNTY SO INTERMITTENT BOUTS
OF LIGHT SNOW WILL OCCUR WEDNESDAY. HIGH TEMPS WILL BE A BIT TRICKY
WITH DIFFERENCES IN THE TIMING OF THE ARRIVAL OF THE COLDEST AIR.
THE GFS REMAINS THE FASTEST WITH THE INFLUX OF H85 TEMPS OF -28C AND
H92 TEMPS OF -24C BY EARLY AFTERNOON...WHILE THE NAM/ECMWF ARE
SLOWER WITH THE ARRIVAL OF AIR THIS COLD UNTIL EVENING. LOCAL
H85/H92 CLIMO UTILIZING A SLOWER ARRIVAL OF THE COLDEST AIR SIDES
MORE WITH SOME OF THE BETTER PERFORMING GUIDANCE OF LATE SUGGESTING
HIGHS IN THE UPPER SINGLE DIGITS NORTHWEST TO THE LOWER TEENS
SOUTHEAST. THESE MAY OCCUR EARLY WITH FALLING TEMPS THROUGH THE DAY.
BASED ON GREATER SUPPORT FOR SLIGHTLY WARMER HIGHS...AT LEAST
EARLY...WILL NUDGE VALUES UP A FEW DEGREES. STEADY NORTHWEST WINDS
WILL KEEP TEMPS FROM RADIATING OUT WEDNESDAY NIGHT THOUGH THEY WILL
STILL FALL TO BETWEEN ABOUT 2 BELOW AND 10 BELOW. THE WINDS WILL
ALSO PUSH WIND CHILLS TO BETWEEN -20 AND -30 F INTO THURSDAY MORNING
SO A WIND CHILL ADVISORY WILL LIKELY BE NEEDED.
MDB
&&
.LONG TERM...
301 AM CST
THURSDAY THROUGH MONDAY...
HIGH PRESSURE WILL STRETCH FROM
MANITOBA TO THE LOWER MISSISSIPPI RIVER VALLEY THURSDAY MORNING AND
STEADILY SLIDE EASTWARD. WESTERN UPPER RIDGING WILL BREAK DOWN AND
BE PUSHED EASTWARD INTO THE AREA AHEAD OF A TROUGH THAT WILL BE
DROPPING SOUTHEAST ACROSS WESTERN CANADA. TIMING OF TEMP
MODIFICATION WILL AGAIN BE AN ISSUE WITH THE GFS BEING THE SLOWEST
ON THE ARRIVAL OF WARMING ALOFT. THE DIFFERENCES MAY BE MOOT AS THE
HIGH WILL BE PASSING OVERHEAD LEAVING WEAK LOW LEVEL FLOW AND WEAK
MIXING. WILL CONTINUE WITH HIGHS FROM ROUND 5 NORTH TO 10 SOUTH
THURSDAY. LAKE EFFECT SNOW CHANCES WILL CONTINUE ACROSS NORTHEAST
PORTER COUNTY THURSDAY BEFORE SUBSIDENCE STARTS TO LIMIT LAKE EFFECT
BY THURSDAY EVENING. THE PATTERN SHIFTS INTO THE WEEKEND WITH THE
BIG EASTERN TROUGH BEING KICKED OUT INTO THE ATLANTIC AND A MORE
ZONAL FLOW SETTING UP ACROSS MOST OF THE U.S. THE AFOREMENTIONED
WESTERN CANADA TROUGH WILL CONTINUE EASTWARD FRIDAY AND MAY BRING
SOME PRECIP TO THE REGION. ENERGY THEN DIGS INTO THE WESTERN U.S.
TRIGGERING SFC LOW DEVELOPMENT OVER TEXAS BY SATURDAY. THIS LOW WILL
RIDE NORTHEAST ALONG A BAROCLINIC ZONE INTO SUNDAY WITH GUIDANCE
CONTINUING TO BE AT ODDS WITH WHERE EXACTLY THE TRACK WILL SET
UP...THOUGH THE SIGNAL FOR THIS SYSTEM OCCURRING IS BECOMING MORE
CONSISTENT. WILL NEED TO KEEP AN EYE ON THIS AS IT WILL DICTATE POPS
OVER THE WEEKEND. WITH THE PATTERN SHIFT TEMPS WILL MODERATE INTO
THE UPPER 20S AND POSSIBLY LOWER 30S SATURDAY WITH COOLER READINGS
SUNDAY AND MONDAY AS ANOTHER STRONG HIGH PRESSURE SYSTEM WILL TAKE
OVER. LESS AMPLIFIED FLOW WILL BE IN PLACE SO THE COOL DOWN WILL NOT
BE AS NOTABLE WITH HIGHS LOOKING TO BE AROUND 20.
MDB
&&
.CLIMATE...
WHILE THE COLDEST AIR ALOFT ARRIVES WEDNESDAY...THE COLDEST SURFACE
TEMPERATURES MAY RESULT ON THURSDAY FEBRUARY 19TH...WHICH RIGHT NOW
APPEARS COULD JEOPARDIZE SOME RECORDS...ESPECIALLY THE LOW MAXS.
FEB 19TH
RECORD LOW RECORD LOW MAX
CHICAGO -7 (1936) 9 (1936)
ROCKFORD -16 (1979) 7 (1959)
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* GUSTY WLY-WNWLY WINDS TO 20 KT THROUGH LATE THIS AFTERNOON.
* POTENTIAL FOR A SHORT PERIOD OF MODERATE SNOW SHOWERS LATE
TONIGHT WITH PERIODS IFR VIS/MVFR CIGS POSSIBLE.
* GUSTY NWLY WINDS TO 25KT TOMORROW.
KREIN
//DISCUSSION...UPDATED 18Z...
A WEAK COLD FRONT HAS PUSHED THROUGH ALL OF THE TERMINALS...EXCEPT
GYY...AT ISSUANCE TIME. EXPECT THAT THE FRONT SHOULD PUSH PAST GYY
WITHIN THE NEXT HOURS OR SO. FOLLOWING THE FROPA...SCT SNOW
SHOWERS HAVE ENDED AND SKIES ARE IMPROVING TO VFR AND WINDS HAVE
SHIFTED TO GENERALLY NWLY. WITH INCREASED SUNSHINE AND POST FRONTAL
COLD ADVECTION...EXPECT GUSTS TO 20KT THROUGH THE AFTERNOON.
ANOTHER PERIOD OF LIGHT SNOW IS POSSIBLE TONIGHT AS A MID LEVEL
IMPULSE CROSSES THE REGION...AROUND THE SOUTHWESTERN PERIPHERY OF A
BROAD UPPER TROUGH COVERING THE ERN/CNTRL CONUS. SINCE THE AIRMASS
OVER THE REGION IS STILL RELATIVELY DRY...ANTICIPATE ONLY MINOR
ACCUMULATIONS...PERHAPS AROUND 1 INCH...BUT WITH WINDS LIKELY TO
REMAIN ABOVE 10KT THROUGH THE NIGHT...EXPECT THE MAIN IMPACT TO BE
REDUCED VISIBILITY...LIKELY DROPPING INTO IFR LEVELS. GIVEN SOME
UNCERTAINTY TO THE EXACT TIMING OF THE SYSTEM CROSSING THE
AREA...WILL MAINTAIN THE GOING PROB30 GROUP...BUT ANTICIPATE THAT
THIS WILL BE UPGRADED TO A TEMPO OR PREVAILING GROUP AS TIMING
BECOMES MORE CERTAIN. FOLLOWING THE PASSAGE OF AN ASSOCIATED SFC
COLD FRONT...VERY COLD AIR WILL FILTER IN ACROSS THE AREA AS
STRONG HIGH PRESSURE BUILDS OVER THE NRN/CNTRL PLAINS AND A WEAK
SFC LOW PRESSURE MOVES THROUGH THE ERN GREAT LAKES. A MODERATE
PRESSURE GRADIENT AND STRONG COLD ADVECTION WILL LEAD TO GUSTY
NWLY WINDS THOUGH THE DAY TOMORROW...WITH GUSTS TO 25KT OR
POSSIBLY HIGHER.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM TO HIGH CONFIDENCE IN WIND TRENDS THROUGH THE PERIOD.
* MEDIUM TO HIGH CONFIDENCE IN ANOTHER ROUND OF LIGHT SNOW LATE TONIGHT.
* MEDIUM CONFIDENCE IN TIMING AND DURATION OF REDUCED CIGS/VIS
ASSOCIATED WITH THE SNOW.
* LOW TO MEDIUM CONFIDENCE IN HOW LOW CIGS/VIS WILL DROP DURG
PERIODS OF SNOW.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR WITH WEST-NORTHWEST WINDS.
THURSDAY...MAINLY VFR. NORTHWEST WINDS.
FRIDAY...CHANCE OF SNOW. IFR POSSIBLE. GUSTY SOUTH WINDS.
SATURDAY...CHANCE OF SNOW. IFR POSSIBLE. SOUTHWEST WINDS BECOMING
NORTHWEST.
SUNDAY...MAINLY VFR. NORTH-NORTHEAST WINDS.
MONDAY...VFR. WESTERLY WINDS.
KJB
&&
.MARINE...
148 AM CST
A PERIOD OF STRONG NORTHWESTERLY WINDS WILL SET UP ACROSS THE LAKE
ON WEDNESDAY AS THE GRADIENT TIGHTENS IN RESPONSE TO THE APPROACH OF
AN ARCTIC SURFACE HIGH OVER THE NORTHERN PLAINS. IT APPEARS THESE
STRONG NORTHWEST WINDS WILL CONTINUE WEDNESDAY NIGHT...WITH A SOLID
30 KT OF WIND EXPECTED. IT ALSO APPEARS THAT SOME 35 KT GALES COULD
OCCUR AT TIMES ACROSS THE SOUTH END OF LAKE MICHIGAN DURING THIS
PERIOD. ALTHOUGH THIS APPEARS TO BE A MARGINAL EVENT FOR GALES...IF
ANY GOOD CONVERGENT BANDS OF LAKE EFFECT SNOW SET UP...THIS COULD
PRODUCE PERIODS OF LOCALLY STRONGER WINDS OVER SOUTHERN AND
EASTERN PORTIONS OF THE LAKE. THEREFORE...I HAVE OPTED TO GO
AHEAD WITH A GALE WATCH FOR WEDNESDAY AND WEDNESDAY NIGHT OVER
SOUTHERN LAKE MICHIGAN...EXCLUDING THE NEAR SHORE WATERS. I WILL
ALSO INCLUDE A HEAVY FREEZING SPRAY WATCH FOR THESE SAME AREAS DUE
TO THE VERY COLD AIRMASS EXPECTED CONCURRENTLY WITH THESE STRONG
WINDS.
WINDS WILL EASE BAY THURSDAY AS THE SURFACE RIDGE OF HIGH PRESSURE
BEGINS TO SHIFT OVER THE WESTERN LAKES REGION. HOWEVER...IT APPEARS
THAT WINDS WILL QUICKLY PICK UP OUT OF THE SOUTH BY FRIDAY AS
ANOTHER CLIPPER SYSTEM TRACKS ACROSS SOUTHERN CANADA. THIS COULD
RESULT IN 30 KT SOUTHERLY WINDS AND MORE FREEZING SPRAY LAKE-WIDE ON
FRIDAY.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...6 AM
WEDNESDAY TO 3 AM THURSDAY.
HEAVY FREEZING SPRAY WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-
LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-
LMZ878...6 AM WEDNESDAY TO 3 AM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1055 AM CST Tue Feb 17 2015
.UPDATE...
ISSUED AT 1050 AM CST TUE FEB 17 2015
Cold front moving through today almost exiting the CWA with brief
clearing behind the boundary. More sc on its way behind the
boundary and expected to develop through the remainder of the
afternoon making the sunshine brief this morning. Cannot rule out
the flurries from the impending short wave and developing cloud
cover. Forecast doing pretty well in the shorter term. No major
adjustments expected in the short term for now, with the sole
exception the brief change in the sky grids before 20z.
&&
.SHORT TERM...(Today)
ISSUED AT 330 AM CST TUE FEB 17 2015
A shortwave will trigger scattered flurries early this morning
across a large portion of central and southeast IL. The back edge
of the band of clouds/flurries is approaching NW IL at 3 am, and
should progress from NW to SE across the area this morning. Will
keep a mention of flurries along that band of clouds as it
progresses across the area.
Even in the clearing behind the shortwave, forecast soundings show
enough residual low level moisture for clouds to redevelop in any
periods of sunshine. Will work a period of clearing in the NW
counties later this morning, but increase clouds again later in the
afternoon.
The short range models continue to show a fast moving wave just west
of IL triggering a band of light snow later this afternoon. As the
wave curves around the south end of IL, snow showers will begin to
develop just south of our counties toward sunset. Have stuck with
just flurries for the snow forecast, and will not carry PoPs for
measurable snow near that feature.
Clear skies and light winds in the areas with new snow cover has
allowed temps early this morning to drop significantly below
guidance. Robinson has reached -10F, Lawrenceville -5, and Mount
Carmel -4 at 3 am. Unless the SE areas see some sunshine early this
afternoon, their highs will likely be affected by the bitterly cold
start to the day. Will trim a few degrees from forecast highs in the
southeast, and remain closer to a MAV/MET blend farther north.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 330 AM CST TUE FEB 17 2015
00Z models continue to dig a strong upper level trof into the
Midwest during midweek and usher in more arctic air into the region
with the coldest temps from Wed thru Thu. A wind chill advisory will
eventually be needed Wed night and Thu morning across central and
southeast IL for wind chills of 15-25 below zero.
A northern stream short wave that digs into the trof over IL/IN
tonight keeps most of its light snow just south of central IL CWA
though scattered flurries will likely occur tonight into Wed. 850 mb
temps drop to -25 to -27C by Wed evening and this to be another
frigid air mass with highs struggling to reach 10F both Wed and Thu.
Lows Tue night in the single digits, then drop into single digits
below zero Wed night and some areas near IN border could dip below
zero again Thu night. A secondary arctic cold front plows se through
central IL late tonight into Wed morning. Brisk nw winds behind this
cold front on Wed will already bring wind chills down to -15F or a
bit colder Wed morning over IL river valley especially nw of the
river and reaching near wind chill advisory criteria. Coldest wind
chills of 15-25 below zero will occur Wed night into Thu morning and
coldest readings over Knox and Stark counties.
Deep upper level trof shifts east of IL Thu night and Friday while
arctic high pressure also drifts east of IL across the Ohio river
valley Thu night and Fri morning. Temps will be slow to climb
however on Friday due to mostly cloudy skies with highs in the low to
mid 20s. Have small chances of light snow Friday afternoon sw
counties ahead of next short wave. Extended models still differ with
handling southern stream storm system this weekend. ECWMF model has
trended further south with it surface low from central IL down to
just south of IL Sat. While GFS has surface low near KY/TN border by
midnight Sat night. GEM model moves low across TN on Sat. Due to
difference in models and from previous runs, stayed close to
guidance pops which are trending upward in southeast IL Sat/Sat
night. Looks cold enough for mainly light snow, though do continue a
mix over southeast IL on Sat. Have just slight chance of light snow
Sunday and then dry across area by Sunday evening. Highs in the low
to mid 30s Sat cool off again early next week on Sunday and Monday
behind this storm system.
The Climate Prediction Center (CPC) day 8-14 outlook for Feb 24-Mar
2 has IL in greater than 60% chance of below normal temperatures and
greater than 40% chance of below normal precipitation. So winter
looks to hold on the next two weeks.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 558 AM CST TUE FEB 17 2015
Low VFR cigs and flurries will affect the TAF sites for a few
hours early this TAF period, under a weak surface trough. A brief
period of MVFR clouds could occur at BMI, but kept the prevailing
conditions VFR. The trough will slide east this morning, with some
clearing for a few hours behind it. HRRR and RAP output indicate
clouds will redevelop during the day as a cold front pushes SE
across the area. Flurries will be possible with that feature. A
strong 500mb vort max diving south tonight into the upper trough
axis will likely trigger MVFR clouds and widespread flurries or
snow showers. Have included prevailing light snow beginning around
06z tonight, but did not introduce any MVFR vis restrictions with
this TAF issuance.
W-SW winds early this morning will become northwest late this
morning, then increase this afternoon to 12-14kts sustained and
gusts to 22kt. Wind gusts will diminish this evening, but
sustained winds could remain around 10kt for much of the night as
the vigorous shortwave moves south into Illinois.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...Shimon
LONG TERM...07
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
442 PM EST TUE FEB 17 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 354 PM EST TUE FEB 17 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR TROF
CENTERED OVER SW HUDSON BAY DOWNSTREAM OF HI AMPLITUDE RDG ALONG THE
W COAST. H5/H7/H85 TEMPS UNDER THE CORE OF THE COLDEST AIR ARND NW
ONTARIO/NE MANITOBA ARE AS LO AS -46C/-33C/-30C RESPECTIVELY.
DESPITE CONSIDERABLE ICE COVER ON LK SUP...ESPECIALLY OVER THE W...
AND THE APRCH OF A WEAK SHRTWV RDG/SOME DNVA...SOME LES CONTINUES IN
THE SN BELTS IMPACTED BY THE COLD NW LLVL FLOW LEFT IN THE WAKE OF A
DISTURBANCE WHICH PASSED LAST NGT. THE MOST OPEN WATER IS LOCATED
OVER THE SCENTRAL PART OF THE LK...SO THE MORE NMRS SN SHOWERS ARE
MOVING INTO THE E HALF OF ALGER COUNTY. LOOKING UPSTREAM...THERE IS
A SHRTWV DIGGING SSEWD THRU MANITOBA. DESPITE PWAT UNDER 0.10
INCH...THERE IS A LARGE AREA OF CLD COVER AND SOME LIGHT SN UNDER
THE DPVA/DEEP LYR QVECTOR CNVGC AHEAD OF THIS SHRTWV WITH 00Z-12Z H5
HGT FALLS AOA 100M AND SOME FAIRLY DEEP MSTR THRU H7 DEPICTED ON THE
12Z YPL ROAB.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON GOING HEADLINES...LES
COVERAGE/AMOUNTS AND TEMPS/LO WIND CHILLS.
TNGT...DIGGING MANITOBA SHRTWV IS PROGGED TO TRACK SSEWD THRU MN AND
INTO WI...WITH DPVA/DEEP LYR QVECTOR CNVGC ON THE CYC SIDE OF THE
TRACK OF THIS FEATURE IMPACTING UPR MI. MODEL FCST SDNGS SHOW DCRSG
STABILITY/DEEPENING MSTR LATE TODAY OVER THE W AND THEN ESPECIALLY
NEAR THE WI BORDER CLOSER TO THE TRACK OF THE DISTURBANCE INTO THE
OVERNGT. WITH THE SHRTWV PASSAGE...THERE WL ALSO BE A REINFORCING
COLD FROPA/WSHFT TO THE NNW THAT IS FCST TO DRAG H85 TEMPS AS LO AS -
30C OVER THE W BY 12Z WED. EARLIER IN THE SEASON...THIS SETUP WOULD
HAVE PRESENTED AN OPPORTUNITY FOR SOME SGNFT LES. BUT CONSIDERABLE
ICE COVER OVER LK SUP AND ABSENCE OF DGZ WITH INFLUX OF BITTERLY
COLD AIR WL GREATLY LIMIT SN TOTALS. THE BEST CHC FOR SOME HEAVIER
LES WL BE IN ALGER COUNTY...WHICH WL BE DOWNWIND OF THE MORE OPEN
WATERS OVER SCENTRAL LK SUP AND IN AREA OF ENHANCED LLVL LAND BREEZE
TYPE CNVGC EXACERBATED BY THE ICE COVER ON LK SUP. BUT WSHFT FM THE
WNW TO NNW IN THE WAKE OF THE COLD FROPA WL SHIFT THE FOCUS FOR THE
MORE NMRS SN SHOWERS FM THE E HALF OF THE COUNTY TO AREAS ARND OR
JUST W OF MUNISING. ALTHOUGH THE DOWNSLOPE NATURE OF THE NW FLOW WL
LIMIT POPS OVER THE SCENTRAL...WL CARRY SOME SCHC/CHC POPS IN THAT
AREA TO ACCOUNT FOR THE PERIOD OF DEEPER HI RH AND DYNAMIC FORCING.
SINCE THE PRES GRADIENT WL TIGHTEN IN THE WAKE OF THE SHRWV
PASSAGE/COLD FROPA...H925 WINDS ARE FCST TO INCRS TO 20-25 KTS
OVERNGT. ALSO...GROWING ICE COVER ON LK SUP WL LIMIT MODERATION OF
THE INCOMING ARCTIC AIRMASS. THESE FACTORS WL RESULT IN AT LEAST
MARGINAL WIND CHILL ADVY CONDITIONS OVER MUCH OF THE W HALF OF UPR
MI AS THE H85 TEMP TUMBLES TOWARD -30C TOWARD 12Z. ALTHOUGH WIND
SPEEDS MAY BE MARGINAL FOR THE ADVY CRITERIA... OPTED TO MAINTAIN
THE GOING HEADLINES AND ADD BARAGA/MARQUETTE COUNTIES TO THE
HEADLINE.
WED...ARRIVAL OF DNVA/DEEP LYR QVECTOR DVGC/SUBSIDENCE IN THE WAKE
OF THE SHRTWV PASSAGE WL TEND TO SUPPRESS LINGERING SN SHOWERS
DOWNWIND OF LK SUP AND END THE PCPN COMPLETELY OVER THE SCENTRAL
DURING THE MRNG. AS THE FLOW BACKS A BIT TO THE NW AGAIN...ALGER
COUNTY WL REMAIN THE FOCUS FOR THE MORE NMRS AND HEAVIER SN
SHOWERS...ESPECIALLY IN THE MRNG. MAINTAINED WINTER WX HEADLINE FOR
ALGER COUNTY TNGT THRU WED AND WED NGT /SEE LONG TERM DISCUSSION.
WITH H85 TEMPS REMAINING NOT FAR FM -30C...EXPECT MAX TEMPS TO
STRUGGLE TO REACH ZERO...ESPCIALLY OVER THE NW HALF WHERE THE WIND
CHILL HEADLINE WL RUN UNTIL 18Z.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 440 PM EST TUE FEB 17 2015
THE OVERALL PATTERN WILL CONTINUE TO BE DOMINATED BY A MID/UPPER
LEVEL RIDGE FROM THE ERN PACIFIC INTO WRN CANADA AND A TROUGH FROM
HUDSON BAY INTO THE CENTRAL AND ERN CONUS. THIS WILL ALLOW ADDITIONAL
BOUTS OF COLD AIR TO MOVE INTO THE WRN LAKES INTO NEXT WEEK WITH
TEMPERATURES REMAINING WELL BELOW NORMAL.
WED NIGHT...THE MAIN FCST ISSUE CONTINUES TO BE THE VERY COLD AIR.
ALTHOUGH WINDS WILL GENERALLY BE LESS THAN 10 MPH...WITH AIR TEMPS
FALLING INTO THE -10 TO -20 RANGE...WIND CHILL VALUES COULD AGAIN
DROP INTO THE -20 TO -30 RANGE EVEN WITH THE WINDS ONLY AROUND 5 MPH.
THE HIGH RES MODELS WERE RELATIVELY CONSISTENT IN FOCUSING LES INTO
ALGER COUNTY DOWNSTREAM OF THE REMAINING OPEN PATCH OF WATER IN THE
DEEPEST PORTION OF LAKE SUPERIOR. FAVORABLE LOW LEVEL CONV IN THE
NARROW OPEN AREA COULD PRODUCE A HEAVIER SNOW BAND WITH ADDITIONAL
SNOW AMOUNTS IN THE 1 TO 4 INCH RANGE ARE EXPECTED.
HOWEVER...CONFIDENCE IS LOW GIVEN THE CHANGING/INCREASING AMOUNTS OF
ICE COVER.
THU AND THU NIGHT...THE ARCTIC HIGH WILL BUILD INTO THE AREA WITH
MAINLY LIGHT WINDS. EXPECT ENOUGH CLEARING FOR TEMPS TO DROP OFF
INTO THE -15 TO 25 RANGE WITH SOME LOCAL READINGS POSSIBLY DOWN TO
AROUND -30F. HOWEVER...MAINLY LIGHT/CALM WINDS SHOULD PREVAIL. ANY
REMAINING LES INTO ALGER COUNTY WILL DIMINISH AND LIFT OFFSHORE AS
WINDS BECOME SW BY EVENING.
FRI INTO FRI NIGHT...A TROUGH MOVING TOWARD THE WRN LAKES WILL
RESULT IN A BROAD WAA PATTERN THROUGH THE REGION. THE MODELS WERE IN
RELATIVELY GOOD AGREEMENT THAT DEEP LAYER ISENTROPIC ASCENT AHEAD
THIS FEATURES WILL PRODUCE SOME LIGHT SNOW. FOR NOW...POPS WERE LEFT
IN THE CHANCE RANGE...BUT WOULD EXPECT THAT IF THE TRENDS HOLD UP A
HIGHER POP LOW QPF/SNOW EVENT WILL DEVELOP WITH OVERALL SNOW AMOUNTS
OF AN INCH OR TWO. THE INCREASING SW FLOW OFF OF LAKE MICHIGAN COULD
BRING A SNOW BAND INTO THE FAR SE CWA BUT WITH THE EXTENSIVE ICE
THAT HAS DEVELOPED OVER NRN LAKE MI...CONFIDENCE IS LOW THAT IT WILL
BRING SIGNIFICANT ADDITIONAL SNOW AMOUNTS.
SAT-TUE...ANOTHER BATCH OF ARCTIC AIR WILL SLIDE INTO THE AREA BY
SUN WITH TEMPS FROM ZERO TO 10 BELOW SAT NIGHT AND IN THE SINGLE
DIGITS SUN. NW WINDS COULD BRING SOME LIGHT SNOW SHOWERS TO THE AREA
FROM ANY REMAINING GAPS IN THE ICE COVER...MAINLY OVER THE EAST
HALF. FCST UNCERTAINTY IS HIGHER BY TUE...AS THE 00Z/12Z ECMWF
REMAINED SIGNIFICANTLY MORE AGGRESSIVE WITH THE NEXT SHRTWV AND
AMOUNT OF COLD MOVING IN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1225 PM EST TUE FEB 17 2015
DESPITE THE PRESENCE OF QUITE A BIT OF ICE COVER OVER WESTERN LK
SUP...EXPECT LES TO PERSIST THIS FCST PERIOD IN A COLD W TO NW FLOW
OF ARCTIC AIR. THE BEST CHC FOR THE SHSN/LOWER IFR VSBYS WL BE AT
CMX AND IWD...WHERE THE LLVL FLOW WL UPSLOPE...AND DURING THE
EVENING/EARLY OVERNGT HRS WHEN A REINFORCING COLD FNT WL SWING THRU
THE AREA. AT CMX...THERE MAY BE SOME IMPROVEMENT LATE WITH THE
DEPARTURE OF DEEPER MSTR AND A MORE UNFAVORABLE NNW WIND. ALTHOUGH
THE SN WILL NOT BE HEAVY...SMALL SN FLAKES ASSOCIATED WITH THE VERY
COLD AIR WL BE EFFICIENT AT REDUCING VSBY...SO IFR CONDITIONS ARE
LIKELY TO PERSIST AT IWD THRU THE ENTIRE PERIOD. DOWNSLOPE NATURE OF
THE FLOW WL LIMIT SN INTENSITY AT SAW...BUT MVFR CIGS ARE STILL
LIKELY TO PREDOMINATE WITH THE INCOMING DISTURBANCE/DEEPER MSTR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 354 PM EST TUE FEB 17 2015
WINDS WILL BE MAINLY 30 KTS OR LESS THE REST OF THE WEEK INTO NEXT
WEEKEND. THERE MAY BE A FEW GALE FORCE GUSTS IN THE VCNTY OF STRONG
BAND OF LAKE EFFECT SNOW OVER SCENTRAL LK SUPERIOR LATE TONIGHT
THROUGH WED NIGHT. HEAVY FREEZING SPRAY COULD DEVELOP IN THE LIMITED
OPEN WATER OF SCENTRAL LK SUPERIOR ON WED NIGHT. ICE COVERAGE WILL
CONTINUE TO EXPAND THROUGH THE WEEK AS ARCTIC AIRMASS SETTLES OVER
THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR MIZ006.
WIND CHILL ADVISORY FROM 4 AM EST /3 AM CST/ TO 1 PM EST /NOON
CST/ WEDNESDAY FOR MIZ001>005-009>011-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLB
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
356 PM EST TUE FEB 17 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 354 PM EST TUE FEB 17 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR TROF
CENTERED OVER SW HUDSON BAY DOWNSTREAM OF HI AMPLITUDE RDG ALONG THE
W COAST. H5/H7/H85 TEMPS UNDER THE CORE OF THE COLDEST AIR ARND NW
ONTARIO/NE MANITOBA ARE AS LO AS -46C/-33C/-30C RESPECTIVELY.
DESPITE CONSIDERABLE ICE COVER ON LK SUP...ESPECIALLY OVER THE W...
AND THE APRCH OF A WEAK SHRTWV RDG/SOME DNVA...SOME LES CONTINUES IN
THE SN BELTS IMPACTED BY THE COLD NW LLVL FLOW LEFT IN THE WAKE OF A
DISTURBANCE WHICH PASSED LAST NGT. THE MOST OPEN WATER IS LOCATED
OVER THE SCENTRAL PART OF THE LK...SO THE MORE NMRS SN SHOWERS ARE
MOVING INTO THE E HALF OF ALGER COUNTY. LOOKING UPSTREAM...THERE IS
A SHRTWV DIGGING SSEWD THRU MANITOBA. DESPITE PWAT UNDER 0.10
INCH...THERE IS A LARGE AREA OF CLD COVER AND SOME LIGHT SN UNDER
THE DPVA/DEEP LYR QVECTOR CNVGC AHEAD OF THIS SHRTWV WITH 00Z-12Z H5
HGT FALLS AOA 100M AND SOME FAIRLY DEEP MSTR THRU H7 DEPICTED ON THE
12Z YPL ROAB.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON GOING HEADLINES...LES
COVERAGE/AMOUNTS AND TEMPS/LO WIND CHILLS.
TNGT...DIGGING MANITOBA SHRTWV IS PROGGED TO TRACK SSEWD THRU MN AND
INTO WI...WITH DPVA/DEEP LYR QVECTOR CNVGC ON THE CYC SIDE OF THE
TRACK OF THIS FEATURE IMPACTING UPR MI. MODEL FCST SDNGS SHOW DCRSG
STABILITY/DEEPENING MSTR LATE TODAY OVER THE W AND THEN ESPECIALLY
NEAR THE WI BORDER CLOSER TO THE TRACK OF THE DISTURBANCE INTO THE
OVERNGT. WITH THE SHRTWV PASSAGE...THERE WL ALSO BE A REINFORCING
COLD FROPA/WSHFT TO THE NNW THAT IS FCST TO DRAG H85 TEMPS AS LO AS -
30C OVER THE W BY 12Z WED. EARLIER IN THE SEASON...THIS SETUP WOULD
HAVE PRESENTED AN OPPORTUNITY FOR SOME SGNFT LES. BUT CONSIDERABLE
ICE COVER OVER LK SUP AND ABSENCE OF DGZ WITH INFLUX OF BITTERLY
COLD AIR WL GREATLY LIMIT SN TOTALS. THE BEST CHC FOR SOME HEAVIER
LES WL BE IN ALGER COUNTY...WHICH WL BE DOWNWIND OF THE MORE OPEN
WATERS OVER SCENTRAL LK SUP AND IN AREA OF ENHANCED LLVL LAND BREEZE
TYPE CNVGC EXACERBATED BY THE ICE COVER ON LK SUP. BUT WSHFT FM THE
WNW TO NNW IN THE WAKE OF THE COLD FROPA WL SHIFT THE FOCUS FOR THE
MORE NMRS SN SHOWERS FM THE E HALF OF THE COUNTY TO AREAS ARND OR
JUST W OF MUNISING. ALTHOUGH THE DOWNSLOPE NATURE OF THE NW FLOW WL
LIMIT POPS OVER THE SCENTRAL...WL CARRY SOME SCHC/CHC POPS IN THAT
AREA TO ACCOUNT FOR THE PERIOD OF DEEPER HI RH AND DYNAMIC FORCING.
SINCE THE PRES GRADIENT WL TIGHTEN IN THE WAKE OF THE SHRWV
PASSAGE/COLD FROPA...H925 WINDS ARE FCST TO INCRS TO 20-25 KTS
OVERNGT. ALSO...GROWING ICE COVER ON LK SUP WL LIMIT MODERATION OF
THE INCOMING ARCTIC AIRMASS. THESE FACTORS WL RESULT IN AT LEAST
MARGINAL WIND CHILL ADVY CONDITIONS OVER MUCH OF THE W HALF OF UPR
MI AS THE H85 TEMP TUMBLES TOWARD -30C TOWARD 12Z. ALTHOUGH WIND
SPEEDS MAY BE MARGINAL FOR THE ADVY CRITERIA... OPTED TO MAINTAIN
THE GOING HEADLINES AND ADD BARAGA/MARQUETTE COUNTIES TO THE
HEADLINE.
WED...ARRIVAL OF DNVA/DEEP LYR QVECTOR DVGC/SUBSIDENCE IN THE WAKE
OF THE SHRTWV PASSAGE WL TEND TO SUPPRESS LINGERING SN SHOWERS
DOWNWIND OF LK SUP AND END THE PCPN COMPLETELY OVER THE SCENTRAL
DURING THE MRNG. AS THE FLOW BACKS A BIT TO THE NW AGAIN...ALGER
COUNTY WL REMAIN THE FOCUS FOR THE MORE NMRS AND HEAVIER SN
SHOWERS...ESPECIALLY IN THE MRNG. MAINTAINED WINTER WX HEADLINE FOR
ALGER COUNTY TNGT THRU WED AND WED NGT /SEE LONG TERM DISCUSSION.
WITH H85 TEMPS REMAINING NOT FAR FM -30C...EXPECT MAX TEMPS TO
STRUGGLE TO REACH ZERO...ESPCIALLY OVER THE NW HALF WHERE THE WIND
CHILL HEADLINE WL RUN UNTIL 18Z.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 529 AM EST TUE FEB 17 2015
STRONG UPPER LOW VCNTY OF NEWFOUNDLAND AND LABRADOR CANADA LIFTS
TOWARD GREENLAND. RESULT IS TROUGHING WITH BITTER COLD EXPANDING FM
NUNAVUT AND HUDSON BAY SOUTH TO THE GREAT LAKES THROUGH LATE THIS
WEEK. CORE OF COLDEST AIR WEDNESDAY INTO THURSDAY. TEMPS MODERATE
FRIDAY AND SATURDAY BEFORE ANOTHER BRIEFER SURGE OF COLDER AIR MOVES
IN LATER IN THE WEEKEND. SIGNS OF A MORE SIGNIFICANT MODERATION IN
TEMPS WAS EXPECTED FOR NEXT WEEK BUT MODELS HAVE TRENDED COLDER SO
THAT ANY MODERATION WOULD NOW BE SHORT LIVED.
LEADING COLD FRONT HAS MOVED THROUGH THE AREA THIS MORNING. SECOND
RE-INFORCING FRONT DUE BY DAYBREAK WEDNESDAY AS SHORTWAVE DROPPING
SOUTH OVER NORTHERN MANITOBA CURRENTLY MOVES ACROSS UPPER GREAT
LAKES. MAIN IMPACT FM THE SHORTWAVE/FROPA IS TO VEER WINDS MORE
NORTHERLY OVR LK SUPERIOR AND TO ADD MOISTURE AND LIFT BLO 10KFT
WHILE INCREASING INVERSIONS TOWARD 10KFT AND LAKE EQL/S NEARING
15KFT. OPEN WATER IS BECOMING A PREMIUM ON LK SUPERIOR WITH LATEST
NUMBERS SHOWING NEARLY 85 PCT OF LK SUPERIOR ICE COVERED. ONLY
APPRECIABLE AREA OF OPEN WATER IS OVER DEEPEST PORTION OF THE LAKE
CENTERED NORTH OF MUNISING...AND THAT IS SHRINKING AS WELL. GIVEN
THE EXTENT OF SFC CONVERGENCE THAT WILL BE PRESENT DUE TO THE
EXPANDING ICE COVER AND EMPHASIZED BY BITTER COLD AIRMASS OVER
REGION...A RELATIVELY NARROW BAND OF LAKE EFFECT SNOW SHOWERS IS
EXPECTED TO FOCUS OVER ALGER AND POSSIBLY NORTHERN SCHOOLCRAFT
COUNTIES WEDNESDAY INTO WEDNESDAY NIGHT. LAKE EFFECT CLOUD LAYER
WILL BE AT TEMPS LOWER THAN -20C. CONTINUE TO EXPECT VERY FINE
FLAKES THAT WILL BE VERY EFFECTIVE AT REDUCING VSBY BUT NOT VERY
GOOD AT ADDING UP TO MUCH SNOW ACCUMULATION. MIXED LAYER WINDS
WITHIN THE BAND TO AROUND 25 KTS SUGGEST GUSTY WINDS AND BLSN
ISSUES.
OVERALL...ADVY THROUGH WEDNESDAY NIGHT FOR ALGER COUNTY LOOKS ON
TRACK. GIVEN DEPTH OF LES AND ABUNDANCE OF SMALL FLAKES WITH SUCH
INSTABILITY...LOCATIONS THAT BECOME DIRECTLY INFLUENCED BY THE
HEAVIEST SNOW BAND WILL LIKELY EXPERIENCE WHITEOUT CONDITIONS. TOUGH
CALL TO SAY EXACTLY WHERE THAT WILL BE THOUGH. MESOSCALE MODELS
/NAM/GEM-REGIONAL AND NCEP WRF MODELS/ AND LOCAL WRF ALL POINT TO
MAIN BAND IMPACTING WESTERN OR CENTRAL ALGER COUNTY NEAR THE SHORE
THEN DRIFTING EAST LATER WEDNESDAY INTO WEDNESDAY NIGHT AS WINDS
BACK WITH ARRIVAL OF SFC HIGH IN THE PLAINS. OBVIOUSLY...WILL BE A
NEAR TERM/NOWCAST EVENT SINCE EVEN DOMINANT BANDS ARE RELATIVELY
NARROW.
MODELS CONTINUE TO SHOW SPOTTY LGT QPF OVER WESTERN COUNTIES. COULD
SEE FLURRIES OR VERY LGT SNOW SHOWERS WITH A FEW BREAKS IN THE ICE
SEEN MONDAY AFTN NEAR THE APOSTLE ISLANDS. GIVEN OVERALL EXTENT OF
BUILDING ICE COVERAGE WILL CONTINUE TO DOWNPLAY THE POPS AND REDUCE
INFLUENCE OF POPS/HIGHER SKY COVER FARTHER INLAND AS DRY ARCTIC HIGH
PRESSURE DRAWS CLOSER WEDNESDAY NIGHT INTO THURSDAY.
BITTER COLD WILL BE MAIN STORY FOR MOST OF UPR MICHIGAN. ONCE TEMPS
FALL BLO ZERO OVER WESTERN CWA ON TUESDAY NIGHT THEY MAY NOT REACH
ABOVE ZERO UNTIL FRIDAY. WIND CHILL ADVISORIES MAY BE NEEDED
WEDNESDAY NIGHT INTO THURSDAY MORNING...BUT IT IS NOT A SURE THING
AS WINDS MAY END UP LESS THAN 5 MPH OVER MOST OF THE CWA. EXCEPTION
WOULD BE RIGHT ALONG LK SUPERIOR SHORE WHERE WINDS WILL BE AROUND 10
MPH AND IT LOOKS JUST COLD ENOUGH FOR ADVY CRITERIA OF 25-35 BELOW
ZERO TO BE MET.
HIGH PRESSURE FIRMLY OVERHEAD ON THURSDAY/THURSDAY NIGHT. LES WILL
DRIFT OFFSHORE OF EASTERN CWA THURSDAY EVENING. WARM AIR ADVECTION
ALOFT BTWN THE HIGH AND LOW PRESSURE TROUGH MOVING OVER NORTHERN
PLAINS RESULTS IN HIGH CLOUDS AFTER MIDNIGHT...BUT HIGH AND LIGHT
WINDS SHOULD BE AROUND LONG ENOUGH INITIALLY IN THE EVENING TO LEAD
TO PLUMMETING TEMPS. LOWERED MINS INTO THE MID 20S BELOW ZERO AT
INTERIOR SPOTS OVER WEST. COLD ALL AREAS THOUGH WITH MINS OVER
ENTIRE CWA OF AT LEAST 10 BELOW. GENERALLY LGT WINDS INLAND BUT
ALONG LK SUPERIOR WINDS WILL BE STEADY ENOUGH TO RESULT IN WIND
CHILLS 25 TO 30 BELOW ZERO.
LOW PRESSURE TROUGH OVER THE NORTHERN PLAINS ON FRIDAY MORNING
CROSSES THE UPPER GREAT LAKES FRIDAY NIGHT INTO SATURDAY MORNING.
PERIOD OF LGT SNOW SHOULD ACCOMPANY THIS SYSTEM. SSW WINDS OFF LK
MICHIGAN MAY RESULT IN LAKE ENHANCEMENT FOR KISQ TO KERY. EXPANDING
ICE COVERAGE ON LK MICHIGAN MAY TEMPER THAT POTENTIAL THOUGH.
SOUNDINGS SHOW A LOT OF THE MOISTURE/LIFT FOR FRIDAY SYSTEM RESIDES
IN DGZ SO SLR/S PUSHING TOWARD 20:1 WILL BOOST THE SNOW
ACCUMULATIONS. MIXING RATIOS AT H7 HAVE TICKED UP SLIGHTLY WITH UP
TO 1.5G/KG FORECAST FRIDAY AFTN INTO FRIDAY EVENING. IF STRONGEST
FORCING DIRECTLY IMPACTS THE AREA...COULD SEE A FEW INCHES OF
SNOW...GREATEST OVER THE EASTERN CWA. BEHIND THIS SYSTEM...ANOTHER
SURGE OF COLD AIR SWEEPS THROUGH FOR SUNDAY. AIRMASS WILL BE DRY AND
THERE WILL BE MORE ICE COVER ON LK SUPERIOR THAN NOW. LES SHOULD BE
MINIMAL IN THE SNOW BELTS EAST OF MARQUETTE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1225 PM EST TUE FEB 17 2015
DESPITE THE PRESENCE OF QUITE A BIT OF ICE COVER OVER WESTERN LK
SUP...EXPECT LES TO PERSIST THIS FCST PERIOD IN A COLD W TO NW FLOW
OF ARCTIC AIR. THE BEST CHC FOR THE SHSN/LOWER IFR VSBYS WL BE AT
CMX AND IWD...WHERE THE LLVL FLOW WL UPSLOPE...AND DURING THE
EVENING/EARLY OVERNGT HRS WHEN A REINFORCING COLD FNT WL SWING THRU
THE AREA. AT CMX...THERE MAY BE SOME IMPROVEMENT LATE WITH THE
DEPARTURE OF DEEPER MSTR AND A MORE UNFAVORABLE NNW WIND. ALTHOUGH
THE SN WILL NOT BE HEAVY...SMALL SN FLAKES ASSOCIATED WITH THE VERY
COLD AIR WL BE EFFICIENT AT REDUCING VSBY...SO IFR CONDITIONS ARE
LIKELY TO PERSIST AT IWD THRU THE ENTIRE PERIOD. DOWNSLOPE NATURE OF
THE FLOW WL LIMIT SN INTENSITY AT SAW...BUT MVFR CIGS ARE STILL
LIKELY TO PREDOMINATE WITH THE INCOMING DISTURBANCE/DEEPER MSTR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 354 PM EST TUE FEB 17 2015
WINDS WILL BE MAINLY 30 KTS OR LESS THE REST OF THE WEEK INTO NEXT
WEEKEND. THERE MAY BE A FEW GALE FORCE GUSTS IN THE VCNTY OF STRONG
BAND OF LAKE EFFECT SNOW OVER SCENTRAL LK SUPERIOR LATE TONIGHT
THROUGH WED NIGHT. HEAVY FREEZING SPRAY COULD DEVELOP IN THE LIMITED
OPEN WATER OF SCENTRAL LK SUPERIOR ON WED NIGHT. ICE COVERAGE WILL
CONTINUE TO EXPAND THROUGH THE WEEK AS ARCTIC AIRMASS SETTLES OVER
THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR MIZ006.
WIND CHILL ADVISORY FROM 4 AM EST /3 AM CST/ TO 1 PM EST /NOON
CST/ WEDNESDAY FOR MIZ001>005-009>011-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1237 PM CST Tue Feb 17 2015
.UPDATE:
Issued at 656 AM CST Tue Feb 17 2015
Latest few runs of the RAP model continue to focus in on southern
Missouri and southern Illinois counties for the heaviest snowfall
late this afternoon and this evening. The model is much more
robust with QPF and is supported by the latest 4km Local WRF with
around 0.25 inches in a band from Shannon County Missouri through
Reynolds, Iron and Madison. Have increasing confidence of the
main band location so have went ahead and increased POPs to
categorical and inched QPF/snowfall up a little more, but not to
the extend that the latest RAP suggests. I also expanded chance POPs
this evening further north into the St. Louis Metro as a stronger
shortwave would also lead to a more broad lighter snow shield to
develop north of the heaviest band ahead of the shortwave. In fact
the latest RAP suggests up to an inch as far north as the Missouri
River. Will brief oncoming dayshift of the trends in the short
term model guidance and the potential need for an advisory across
the far southern counties of the CWA late this afternoon and this
evening.
CVKING
&&
.SHORT TERM: (Through Late This Afternoon)
Issued at 332 AM CST Tue Feb 17 2015
Next shortwave helping to dig out the upper level trof across the
eastern 2/3rds of the CONUS will bring another shot of accumulating
snow across mainly the southern zones of the CWA this afternoon and
this evening. Used a model consensus approach for location of POPs
and increased them into the likely category. Dayshift will need to
fine tune and increase to categorical once the band of snow begins
to develop. Certainly appears that there will be enough lift and
moisture to justify increasing snowfall amounts a tad as well with
up to two inches possible within the band of snow. Otherwise,
temperatures today will respond nicely ahead of the approaching cold
front from the north, with highs ranging from the 20s north to the
30s south.
CVKING
.LONG TERM: (Tonight through Monday)
Issued at 332 AM CST Tue Feb 17 2015
(Wednesday through Thursday)
Focus thru this period will be temps with little in the way of
precip currently anticipated.
Have kept dry PoPs going for Wed attm. Given progd soundings thru
Wed, expect flurries to be possible throughout the day. However, it
seems plausible that bands will be possible where more than just
flurries may be possible. This, of course, is a short term forecast
issue.
Otherwise, only minor changes to temps have been made as prev
forecast still appears to be on track. Continued the cold trend, aob
coldest guidance at most times especially overnight. Mdls are in
good agreement with the sfc ridge building into the area Wed night.
As clouds clear out of the region, temps shud drop quickly with
snowpack across the region. Thurs shud be slightly warmer across
most of the CWA as the sfc ridge builds ewd and thermal ridge
approaches the area.
(Friday through Monday)
Overall, not a lot of change from the prev forecast thru the extd.
Mdls continue to indicate the potential for another measurable SN
event Thurs night into Fri. Mdls are in somewhat good agreement with
a s/w embedded within the NW flow Thurs night, with good low and mid
level frontogenesis. Mdls have come into slightly better agreement
and have raised PoPs a bit. However, questions remain regarding
exactly where this precip band may set up.
As the deep upper low finally pulls newd out into the nrn Atlantic,
flow become much more zonal this weekend with the next trof digging
into wrn U.S. Mdl spread increases with individual s/ws thru the
extd. The GEM becomes an outlier thru much of this period and have
trended away from this soln.
However, mdls are in relatively good agreement with a sfc low
developing with an associated trof on Sat. Increased PoPs across
mainly srn portions of the region. While mdl thermal profiles are
currently in close agreement, this may change as the system
approaches. Believe it was prudent to add another p-type as current
trends suggest that many p-types will be possible or probable.
However, have currently only added IP to the forecast as this is the
other dominant p-type currently expected. As the thermal ridge
builds into the area, it is very possible that precip will change
from SN, to IP, to FZRA to RA and back again during this event. Will
leave these details to future forecasts as confidence builds and
mdls come into better agreement.
Beyond this system, mdls build another ridge into the region,
bringing colder temps. However, current indications are that this
ridge will not be as cold as earlier this week.
Tilly
&&
.AVIATION: (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 1208 PM CST Tue Feb 17 2015
Cold front extending from northern MI southwest through STL and
COU will continue moving southeastward with the surface wind
becoming nwly behind the front. Areas of low level clouds around
3000-6000 feet will continue to advect southeastward through the
area this afternoon and tonight. An upper level disturbance will
move east-southeastward through the area tonight, while a
secondary cold front moves southeastward through the taf sites
late tonight and Wednesday morning. Some light snow can be
expected this evening, mainly south of the taf sites, although
flurries or a brief period of light snow is possible further
north. For now will just include flurries in the tafs with no
visibility restrictions. The surface wind will strengthen and
become gusty Wednesday morning after passage of the secondary cold
front. The cloud ceilings may lower into the MVFR catagory as well
Wednesday morning after fropa.
Specifics for KSTL: Low level, VFR cloudiness will continue to
advect southeastward through STL this aftenoon and tonight, with
cigs likely dropping down to the MVFR catagory Wednesday morning.
There may be a brief period of light snow this evening, but for
now will just include flurries in the STL TAF tonight with no
visibility restrictions. Light surface wind should become nwly
later this afternoon, then become relatively strong and gusty
after the passage of a second cold front Wednesday morning.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
247 PM MST TUE FEB 17 2015
.SHORT TERM...VALID FOR WED AND THU...
AN AREA OF LIGHT SNOW SHOWERS STILL HANGING ON FROM ROUNDUP TO
FORT SMITH TO SHERIDAN. AREA RESPONDING TO A WEAK BAROCLINIC ZONE
AND JET DYNAMICS. HRRR LINGERS THIS ACTIVITY THROUGH THE EVENING.
ADDED SOME LOW POPS TONIGHT AS MOISTURE LOOKS RATHER LIMITED. WARM
AIR ALOFT OVERNIGHT WILL CAUSE ACTIVITY TO SHIFT EAST AND BECOME
MORE FLURRIES...SO ADDED LATE TONIGHT INTO WEDNESDAY.
WARMER TEMPERATURES IN STORE FOR WEDNESDAY AS THE RIDGE TO THE
WEST SHIFTS EAST AND FLATTENS OUT. DOWNSLOPE FLOW WILL DRY US OUT
AND ALLOW HIGHS TO REACH THE UPPER 40S TO LOWER 50S OVER WESTERN
AND CENTRAL ZONES. THE EAST WILL BE A LITTLE COOLER AS THE SURFACE
TROUGH DOES NOT QUITE CLEAR THE STATE. WINDS WILL PICK UP OVER THE
WEST WEDNESDAY AFTERNOON AND NIGHT. 700MB WINDS REACH 45KTS AND
LOCAL GUIDANCE TOOLS INDICATE WINDS SHOULD STAY BELOW HIGHLIGHT
CRITERIA...SO LEFT WIND HIGHLIGHTS ON THE SIDELINE. THAT BEING
SAID...SHOULD BE WINDY AND MAINTAINED STRONG WIND GUSTS MENTIONED
IN THE GRIDS.
THE SURFACE TROUGH WILL SLIDE INTO THE DAKOTAS WEDNESDAY NIGHT
AND THURSDAY AND ALLOW ALL LOCATIONS TO EXPERIENCE ABOVE SEASONAL
TEMPERATURES. WEAK ENERGY SLIPS ACROSS THE AREA...BUT WILL BE
STARVED FOR MOISTURE DURING THE DAY. DEEPER MOISTURES FLOWS INTO
THE FORECAST AREA THURSDAY NIGHT BEHIND THE INITIAL WAVE...SO KEPT
POPS IN THEN. TWH
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
AN UPPER LEVEL TROUGH WILL MOVE SOUTH ACROSS IDAHO INTO UTAH
FRIDAY. AS IT DOES...IT WILL DROP ANOTHER COLD FRONT ACROSS OUR
FORECAST AREA USHERING IN GUSTY NORTHERLY WINDS. THIS WILL RESULT
IN AN UNSTABLE NORTH TO NORTHWEST FLOW ALOFT DURING THE DAY AND
CONTINUING THROUGH SATURDAY. SCATTERED RAIN AND SNOW SHOWERS
FRIDAY WILL CHANGE TO ALL SNOW FRIDAY EVENING/NIGHT. THE MOST
FAVORED AREAS FOR ACCUMULATING SNOW WILL BE THE MOUNTAIN
LOCATIONS...AS WELL AS THE BEARTOOTH/ABSAROKA FOOTHILLS. THIS
INITIAL COLD FRONT WILL NOT BE TOO COLD WITH THE COLDER AIR THOUGH
BEING ACROSS OUR FAR EASTERN AREAS. HOWEVER...A SECONDARY SHOT OF
COLD AIR MOVES SOUTH AND FURTHER WEST LATE IN THE DAY SATURDAY
INTO SUNDAY BRINGING ANOTHER CHANCE FOR LIGHT SNOW TO THE FORECAST
AREA. TEMPERATURES FRIDAY WILL BE AT OR SLIGHTLY ABOVE NORMAL
BEFORE DROPPING BELOW NORMAL SATURDAY AND SUNDAY.
HIGH PRESSURE RIDGING BUILDS BACK ACROSS THE FORECAST AREA MONDAY
BRINGING WARMER TEMPERATURES. HOWEVER...THIS LOOKS TO BE SHORT-
LIVED AS ANOTHER DISTURBANCE WILL MOVE SOUTHEAST OUT OF CANADA
ALONG WITH A COLD FRONT LATE TUESDAY/TUESDAY NIGHT BRINGING
ANOTHER CHANCE FOR SNOW ALONG WITH COLDER TEMPERATURES. HOOLEY
&&
.AVIATION...
LIGHT SNOW SHOWERS WILL CONTINUE THROUGH 06Z ACROSS THE CENTRAL
AND SOUTHERN AREAS...MAINLY IMPACTING KSHR WHERE OCCASIONAL MVFR
CONDITIONS WILL BE POSSIBLE. THE MOUNTAINS AND FOOTHILLS AREAS
WILL BE OBSCURED AT TIMES ESPECIALLY ACROSS THE BIG HORN
MOUNTAINS. ELSEWHERE...VFR CONDITIONS WILL PREVAIL THROUGH THIS
EVENING AND OVERNIGHT HOURS. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
WED THU FRI SAT SUN MON TUE
-----------------------------------------------------------
BIL 020/048 033/056 033/046 027/032 014/032 021/043 027/045
10/B 01/N 23/O 44/S 21/B 12/O 22/O
LVM 024/053 035/054 034/043 025/035 013/033 020/043 029/048
00/N 01/N 24/O 46/S 32/S 12/O 22/R
HDN 017/042 026/053 028/045 025/031 012/031 017/041 024/043
21/E 01/B 23/O 44/S 21/B 12/S 22/O
MLS 007/030 019/045 025/040 020/025 007/027 017/038 019/038
01/M 11/B 23/O 32/S 21/B 12/S 22/S
4BQ 009/031 021/048 026/043 022/029 009/028 016/041 021/040
11/M 01/B 23/O 33/S 21/B 02/S 22/O
BHK 903/024 013/039 024/037 015/020 002/023 013/035 016/034
01/B 12/W 23/O 32/S 10/U 02/S 22/S
SHR 015/041 024/052 026/041 022/029 009/027 011/040 022/042
20/B 01/B 24/O 45/S 32/S 12/S 22/O
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
1144 AM MST TUE FEB 17 2015
.UPDATE...
CANCELLED THE REMAINDER OF THE WINTER WEATHER ADVISORIES.
ACTIVITY HAS DECREASED TO A SCATTERED LIGHT SNOW SHOWERS. TWH
&&
.SHORT TERM...VALID FOR TDY AND WED...
SNOW SHOWER ACTIVITY EARLY THIS MORNING WILL GRADUALLY WANE TODAY
AND LEAD TO A DRIER WEATHER PATTERN TONIGHT AND WEDNESDAY.
A NARROW BAND OF RELATIVELY INTENSE SNOW FORMED AFTER MIDNIGHT IN
CENTRAL YELLOWSTONE COUNTY AND WAS CENTERED ACROSS THE BILLINGS
HEIGHTS WHERE SPOTTERS HAVE REPORTED UP TO 3 INCHES OF SNOW AS OF
300 AM MST. THIS BAND FORMED IN UNSTABLE NORTHWEST FLOW ALOFT...
AND WAS ENHANCED IN THE VICINITY OF A WEAK SURFACE WIND SHIFT. IT
WAS VERY NARROW /LESS THAN 5 MILES WIDE/ AND THUS VERY DIFFICULT
TO ANTICIPATE RIGHT UP UNTIL RADAR BEGAN TO SUPPORT ITS FORMATION.
SOME VERY RECENT RADAR TRENDS AS OF 330 AM MST SUGGEST THE BAND
IS WEAKENING...SO ADDITIONAL ACCUMULATION IN THE CITY THROUGH
EARLY THIS MORNING WILL LIKELY BE LESS THAN AN INCH.
OTHERWISE...SNOW SHOWER ACTIVITY IS ALSO CONTINUING OVER FAR SOUTH
CENTRAL MT AND NORTH CENTRAL WY AS OF 330 AM MST...AND OVERNIGHT
MODEL TRENDS SUGGEST IT WILL LINGER THROUGH THE MORNING. HRRR RUNS
EVEN HANG ONTO SNOW IN THE FORT SMITH AND SHERIDAN AREA RIGHT INTO
THE AFTERNOON...THOUGH WITH DECREASING INTENSITY IN TIME. WE THUS
EXTENDED THE WINTER WEATHER ADVISORY FOR BIG HORN...SOUTHERN ROSE-
BUD AND SHERIDAN COUNTIES AND THE NORTHEAST BIGHORN MOUNTAINS OUT
UNTIL NOON MST TODAY. ADDITIONAL ACCUMULATIONS SHOULD ONLY BE ONE
OR TWO INCHES...BUT ROADS WILL REMAIN SLIPPERY AND SNOW COVERED.
BY THIS EVENING...THE AIR MASS WILL BE STABILIZING AS THE HEIGHTS
ALOFT RISE. WE THUS HAVE A DRY FORECAST IN PLAY OVERNIGHT TONIGHT
AND INTO WEDNESDAY...THOUGH AS WARM AIR ADVECTION ALOFT GETS GOING
THERE ARE HINTS IN SOME 00 UTC GUIDANCE FOR VERY LIGHT SNOW ACROSS
SOUTHEASTERN MT TONIGHT INTO WEDNESDAY. FORECAST SOUNDINGS SUGGEST
SATURATION WILL BE LIMITED IN THE NEAR-SURFACE LAYER THOUGH AND SO
WE KEPT WITH THE IDEA OF A DRY FORECAST FOR NOW.
HIGHS TODAY WILL BE COOL...RANGING FROM THE TEENS EAST AND PERHAPS
IN AREAS WHERE SNOW COVER IS GREATEST TO THE 30S F ACROSS SOUTH
CENTRAL MT. WARMING WILL BEGIN IN EARNEST WEDNESDAY ACROSS SOUTH
CENTRAL MT WITH HIGHS IN THE 50S F IN THE FOOTHILLS...BUT MIXING
WILL BE LIMITED FURTHER EAST IN SOUTHEASTERN MT WITH CLOUD COVER
AND LIGHT SOUTHEAST WINDS AHEAD OF A DEVELOPING WARM FRONT. HIGHS
WILL THUS STAY IN THE 20S F WEDNESDAY ACROSS FAR SOUTHEASTERN MT
AND IN FACT OUR FORECAST BE OPTIMISTIC IN SPOTS. SCHULTZ
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
THURSDAY WILL BE MILD BEHIND A PACIFIC FRONTAL PASSAGE...WITH
FAIRLY STRONG WEST WINDS ALONG OUR FOOTHILLS ESPECIALLY IN THE
MORNING. OUR WEST AND CENTRAL PARTS SHOULD BE WELL-MIXED AND SEE
TEMPS RISE INTO THE 50S...BUT LATEST MODEL RUNS SUGGEST THE SFC
TROF MAY NOT PUSH ALL THE WAY TO THE DAKOTAS...KEEPING PLACES LIKE
BAKER AND EKALAKA COLDER THAN THE REST OF THE CWA. WILL NEED TO
KEEP AN EYE ON THE WINDS AS THE USUAL FOOTHILL LOCATIONS SHOULD
SEE GUSTS TO 50 MPH.
CONFIDENCE CONTINUES TO INCREASE IN A SURGE OF COLD CANADIAN AIR
BY THE END OF THE WEEK. COLD ADVECTION WILL ACTUALLY BEGIN
FRIDAY...IE MAYBE A COMBINATION OF RAIN AND SNOW SHOWERS ON THIS
DAY WITH SHORTWAVE ENERGY FROM THE NW. INTERESTING FACET OF THIS
HIGHLY AMPLIFYING FLOW IS THE POSITIVELY TILTED NATURE OF THE TROF
AS IT PUSHES TOWARD THE NORTHERN GREAT BASIN...WITH STRONG UPPER
RIDGING OFF THE PAC COAST INTO BRITISH COLUMBIA. THIS SHOULD ALLOW
FOR STRONG CANADIAN SFC RIDGING OVER EASTERN MT...WHICH ALL MODELS
SHOW HAPPENING...WITH PRESSURES TO NEAR 1050MB OVER NORTH DAKOTA
BY 12Z SUNDAY PER THE GFS ENSEMBLE MEAN. AS A RESULT WE ARE
LOOKING AT A COUPLE OF FAIRLY COLD DAYS SATURDAY AND SUNDAY.
MODELS STILL DIFFER IN MAGNITUDE OF COLD...SOME SUGGEST 850MB
TEMPS NEAR -20C BY EARLY SUNDAY...WHICH WOULD BE THE COLDEST WE
HAVE SEEN IN QUITE SOME TIME. MAIN FORECAST ADJUSTMENTS WERE TO
RAISE POPS FOR WHAT WILL BE SNOWFALL FRIDAY NIGHT AND SATURDAY...
THIS IS THE TIME OF GREATEST BAROCLINICITY...AND TO LOWER TEMPS
SEVERAL DEGREES SATURDAY AND SUNDAY. IT DOES APPEAR WE WILL SEE
DRYING BY SUNDAY AS THE TROF PUSHES SOUTH OF US...AND CONSENSUS IS
FOR KLONDIKE CHINOOKING BY LATE SUNDAY OR SUNDAY NIGHT.
ACTIVE NORTHERLY FLOW WILL CONTINUE INTO NEXT WEEK AS MORE ENERGY
MOVES INTO OUR AREA BY MONDAY. WILL ADD CLIMO POPS WITH A MODEST
WARMING TREND EARLY NEXT WEEK.
JKL
&&
.AVIATION...
SNOW SHOWERS WILL CONTINUE THIS MORNING ACROSS THE SOUTHERN
PORTIONS OF OUR FORECAST AREA...MAINLY IMPACTING KSHR. THE SNOW
SHOWERS WILL PRODUCE LOCALIZED MVFR TO IFR CONDITIONS BUT WILL
TAPER OFF BY EARLY THIS AFTERNOON. THE MOUNTAINS WILL BE OBSCURED
AT TIMES. OTHERWISE...VFR CONDITIONS WILL PREVAIL TODAY. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 034 021/048 034/056 033/048 027/034 016/034 021/043
1/E 10/B 01/N 23/O 45/S 21/B 12/W
LVM 039 025/053 036/054 034/045 025/037 015/035 020/043
1/B 00/N 01/N 24/O 45/S 32/S 12/W
HDN 031 018/042 027/053 028/047 025/033 014/033 017/041
2/J 11/E 01/B 23/O 44/S 21/B 12/J
MLS 023 008/030 020/045 025/042 020/027 009/029 017/038
1/N 11/E 11/B 22/S 32/S 21/B 12/J
4BQ 023 010/031 022/048 026/045 022/031 011/030 016/041
2/J 11/E 11/B 22/O 33/S 21/B 12/J
BHK 017 902/024 014/039 024/039 015/022 004/025 013/035
0/N 11/B 12/W 23/S 32/S 11/B 12/J
SHR 028 016/041 025/052 026/043 022/031 011/029 011/040
5/J 20/B 00/B 23/O 45/S 32/S 12/J
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
924 AM MST TUE FEB 17 2015
.UPDATE...
SNOW SHOWER ACTIVITY WINDING DOWN OVER SOUTHERN SECTIONS. STILL
LIGHTLY SNOWING AT SHERIDAN WITH STRONGER RETURNS OVER THE
BIGHORNS. WEAK ECHOS EXTEND NORTHWEST TOWARD LEWISTOWN BUT NOTHING
SIGNIFICANT. DECIDED TO DROP NORTHERN BIG HORN AND SOUTHERN
ROSEBUD COUNTIES OUT OF THE ADVISORY AND DROP POPS TO SCATTERED.
WILL KEEP SHERIDAN COUNTY AND THE BIGHORN MOUNTAINS GOING FOR A
COUPLE MORE HOURS. COLD START IN BAKER WITH LOWS FALLING BELOW
ZERO. MAY NOT BE ABLE TO REACH FORECAST HIGH THERE...BUT WITH
SUNSHINE...WILL LET FORECAST RIDE. REST OF THE FORECAST IN GOOD
SHAPE. TWH
&&
.SHORT TERM...VALID FOR TDY AND WED...
SNOW SHOWER ACTIVITY EARLY THIS MORNING WILL GRADUALLY WANE TODAY
AND LEAD TO A DRIER WEATHER PATTERN TONIGHT AND WEDNESDAY.
A NARROW BAND OF RELATIVELY INTENSE SNOW FORMED AFTER MIDNIGHT IN
CENTRAL YELLOWSTONE COUNTY AND WAS CENTERED ACROSS THE BILLINGS
HEIGHTS WHERE SPOTTERS HAVE REPORTED UP TO 3 INCHES OF SNOW AS OF
300 AM MST. THIS BAND FORMED IN UNSTABLE NORTHWEST FLOW ALOFT...
AND WAS ENHANCED IN THE VICINITY OF A WEAK SURFACE WIND SHIFT. IT
WAS VERY NARROW /LESS THAN 5 MILES WIDE/ AND THUS VERY DIFFICULT
TO ANTICIPATE RIGHT UP UNTIL RADAR BEGAN TO SUPPORT ITS FORMATION.
SOME VERY RECENT RADAR TRENDS AS OF 330 AM MST SUGGEST THE BAND
IS WEAKENING...SO ADDITIONAL ACCUMULATION IN THE CITY THROUGH
EARLY THIS MORNING WILL LIKELY BE LESS THAN AN INCH.
OTHERWISE...SNOW SHOWER ACTIVITY IS ALSO CONTINUING OVER FAR SOUTH
CENTRAL MT AND NORTH CENTRAL WY AS OF 330 AM MST...AND OVERNIGHT
MODEL TRENDS SUGGEST IT WILL LINGER THROUGH THE MORNING. HRRR RUNS
EVEN HANG ONTO SNOW IN THE FORT SMITH AND SHERIDAN AREA RIGHT INTO
THE AFTERNOON...THOUGH WITH DECREASING INTENSITY IN TIME. WE THUS
EXTENDED THE WINTER WEATHER ADVISORY FOR BIG HORN...SOUTHERN ROSE-
BUD AND SHERIDAN COUNTIES AND THE NORTHEAST BIGHORN MOUNTAINS OUT
UNTIL NOON MST TODAY. ADDITIONAL ACCUMULATIONS SHOULD ONLY BE ONE
OR TWO INCHES...BUT ROADS WILL REMAIN SLIPPERY AND SNOW COVERED.
BY THIS EVENING...THE AIR MASS WILL BE STABILIZING AS THE HEIGHTS
ALOFT RISE. WE THUS HAVE A DRY FORECAST IN PLAY OVERNIGHT TONIGHT
AND INTO WEDNESDAY...THOUGH AS WARM AIR ADVECTION ALOFT GETS GOING
THERE ARE HINTS IN SOME 00 UTC GUIDANCE FOR VERY LIGHT SNOW ACROSS
SOUTHEASTERN MT TONIGHT INTO WEDNESDAY. FORECAST SOUNDINGS SUGGEST
SATURATION WILL BE LIMITED IN THE NEAR-SURFACE LAYER THOUGH AND SO
WE KEPT WITH THE IDEA OF A DRY FORECAST FOR NOW.
HIGHS TODAY WILL BE COOL...RANGING FROM THE TEENS EAST AND PERHAPS
IN AREAS WHERE SNOW COVER IS GREATEST TO THE 30S F ACROSS SOUTH
CENTRAL MT. WARMING WILL BEGIN IN EARNEST WEDNESDAY ACROSS SOUTH
CENTRAL MT WITH HIGHS IN THE 50S F IN THE FOOTHILLS...BUT MIXING
WILL BE LIMITED FURTHER EAST IN SOUTHEASTERN MT WITH CLOUD COVER
AND LIGHT SOUTHEAST WINDS AHEAD OF A DEVELOPING WARM FRONT. HIGHS
WILL THUS STAY IN THE 20S F WEDNESDAY ACROSS FAR SOUTHEASTERN MT
AND IN FACT OUR FORECAST BE OPTIMISTIC IN SPOTS. SCHULTZ
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
THURSDAY WILL BE MILD BEHIND A PACIFIC FRONTAL PASSAGE...WITH
FAIRLY STRONG WEST WINDS ALONG OUR FOOTHILLS ESPECIALLY IN THE
MORNING. OUR WEST AND CENTRAL PARTS SHOULD BE WELL-MIXED AND SEE
TEMPS RISE INTO THE 50S...BUT LATEST MODEL RUNS SUGGEST THE SFC
TROF MAY NOT PUSH ALL THE WAY TO THE DAKOTAS...KEEPING PLACES LIKE
BAKER AND EKALAKA COLDER THAN THE REST OF THE CWA. WILL NEED TO
KEEP AN EYE ON THE WINDS AS THE USUAL FOOTHILL LOCATIONS SHOULD
SEE GUSTS TO 50 MPH.
CONFIDENCE CONTINUES TO INCREASE IN A SURGE OF COLD CANADIAN AIR
BY THE END OF THE WEEK. COLD ADVECTION WILL ACTUALLY BEGIN
FRIDAY...IE MAYBE A COMBINATION OF RAIN AND SNOW SHOWERS ON THIS
DAY WITH SHORTWAVE ENERGY FROM THE NW. INTERESTING FACET OF THIS
HIGHLY AMPLIFYING FLOW IS THE POSITIVELY TILTED NATURE OF THE TROF
AS IT PUSHES TOWARD THE NORTHERN GREAT BASIN...WITH STRONG UPPER
RIDGING OFF THE PAC COAST INTO BRITISH COLUMBIA. THIS SHOULD ALLOW
FOR STRONG CANADIAN SFC RIDGING OVER EASTERN MT...WHICH ALL MODELS
SHOW HAPPENING...WITH PRESSURES TO NEAR 1050MB OVER NORTH DAKOTA
BY 12Z SUNDAY PER THE GFS ENSEMBLE MEAN. AS A RESULT WE ARE
LOOKING AT A COUPLE OF FAIRLY COLD DAYS SATURDAY AND SUNDAY.
MODELS STILL DIFFER IN MAGNITUDE OF COLD...SOME SUGGEST 850MB
TEMPS NEAR -20C BY EARLY SUNDAY...WHICH WOULD BE THE COLDEST WE
HAVE SEEN IN QUITE SOME TIME. MAIN FORECAST ADJUSTMENTS WERE TO
RAISE POPS FOR WHAT WILL BE SNOWFALL FRIDAY NIGHT AND SATURDAY...
THIS IS THE TIME OF GREATEST BAROCLINICITY...AND TO LOWER TEMPS
SEVERAL DEGREES SATURDAY AND SUNDAY. IT DOES APPEAR WE WILL SEE
DRYING BY SUNDAY AS THE TROF PUSHES SOUTH OF US...AND CONSENSUS IS
FOR KLONDIKE CHINOOKING BY LATE SUNDAY OR SUNDAY NIGHT.
ACTIVE NORTHERLY FLOW WILL CONTINUE INTO NEXT WEEK AS MORE ENERGY
MOVES INTO OUR AREA BY MONDAY. WILL ADD CLIMO POPS WITH A MODEST
WARMING TREND EARLY NEXT WEEK. JKL
&&
.AVIATION...
SNOW SHOWERS WILL CONTINUE THIS MORNING ACROSS THE SOUTHERN
PORTIONS OF OUR FORECAST AREA...MAINLY IMPACTING KSHR. THE SNOW
SHOWERS WILL PRODUCE LOCALIZED MVFR TO IFR CONDITIONS BUT WILL
TAPER OFF BY EARLY THIS AFTERNOON. THE MOUNTAINS WILL BE OBSCURED
AT TIMES. OTHERWISE...VFR CONDITIONS WILL PREVAIL TODAY. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 034 021/048 034/056 033/044 025/031 011/029 019/041
3/J 10/B 01/N 23/O 45/S 21/B 12/W
LVM 039 025/053 036/054 034/045 025/034 012/032 018/042
1/B 00/N 01/N 24/O 45/S 32/S 12/W
HDN 031 018/042 027/053 028/045 023/032 010/028 012/039
5/J 11/E 01/B 23/O 44/S 21/B 12/J
MLS 023 008/030 020/045 025/039 017/028 006/028 014/036
1/N 11/E 11/B 22/S 32/S 21/B 12/J
4BQ 023 010/031 022/048 026/042 020/029 008/024 010/037
2/J 11/E 11/B 22/O 33/S 21/B 12/J
BHK 017 902/024 014/039 024/036 012/023 000/020 008/034
1/N 11/B 12/W 23/S 32/S 11/B 12/J
SHR 028 016/041 025/052 026/044 022/032 010/026 009/038
9/J 20/B 00/B 23/O 45/S 32/S 12/J
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL NOON MST TODAY FOR
ZONE 38.
WY...WINTER WEATHER ADVISORY IN EFFECT UNTIL NOON MST TODAY FOR
ZONES 98-99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORMAN OK
1226 PM CST TUE FEB 17 2015
.UPDATE...
RADAR IS SHOWING PRECIPITATION DEVELOPING ACROSS THE NORTHERN
TEXAS PANHANDLE... ALTHOUGH SOME OF THIS MAY BE VIRGA AT THIS
TIME. BUT GIVEN THIS INCREASE IN COVERAGE AND THE HRRR AND RAP
BOTH SHOWING SOME FORECAST REFLECTIVITY AND QPF MOVING ACROSS THE
AREA THIS AFTERNOON. THEREFORE WE HAVE EXPANDED THE POPS /ALBEIT
LOW POPS/ ACROSS ALMOST ALL OF THE AREA.
&&
.PREV DISCUSSION... /ISSUED 523 AM CST TUE FEB 17 2015/
DISCUSSION...
THE 12Z AVIATION DISCUSSION FOLLOWS....
AVIATION...
A COLD FRONT WILL BRING A WIND SHIFT AND INCREASING WINDS TO THE
REGION TODAY...WHILE AN ASSOCIATED UPPER-LEVEL DISTURBANCE WILL
GENERATE A FEW SHRA AT TIMES. THE SHRA WILL BE TOO MINOR IN
IMPACT...AND TOO FEW IN NUMBER...TO WARRANT ANY MENTION IN THE
TAFS. WINDS WILL DECREASE AND BECOME MORE VARIABLE IN DIRECTION
AFTER SUNSET.
PREV DISCUSSION... /ISSUED 433 AM CST TUE FEB 17 2015/
DISCUSSION...
A FEW SHOWERS MAY OCCUR TODAY AS WEAK DISTURBANCES CIRCULATE
THROUGH A LARGE UPPER-LEVEL TROUGH. TEMPERATURES WILL RISE TO NEAR
THE AVERAGE FOR THIS TIME OF YEAR TODAY...BUT A SLIGHT
REINFORCEMENT OF THE COLDER AIR WILL MAKE TOMORROW A BIT COLDER.
A SURFACE LOW WILL DEVELOP OVER WEST TEXAS THURSDAY AND THURSDAY
NIGHT...AND CIRCULATION AROUND THIS FEATURE WILL BRING A SURGE OF
WARMER AND MUCH MORE HUMID AIR INTO OUR SOUTHERN COUNTIES.
THIS WARMER AND MORE HUMID AIR WILL CONTINUE ITS NORTHWARD
ADVANCE ON FRIDAY...LEADING TO A CLOUDY...HUMID DAY ACROSS MOST OF
OKLAHOMA AND NORTH TEXAS. A FEW SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE FRIDAY AND FRIDAY NIGHT AS THE OVERALL STORM SYSTEM
BEGINS TO SHIFT EAST.
A STRONG COLD FRONT WILL ADVANCE SOUTHEAST ACROSS OKLAHOMA AND
NORTH TEXAS SATURDAY AND SATURDAY NIGHT. THIS WILL BRING MUCH
COOLER AIR INTO THE REGION. RAIN CHANCES WILL CHANGE TO SNOW
CHANCES IN THE NORTH INITIALLY...AND THE RAIN/SNOW LINE WILL SHIFT
BACK AND FORTH ACROSS THE REGION UNTIL MONDAY NIGHT...WHEN
RAIN/SNOW CHANCES FINALLY END. AT THIS TIME...IT DOES NOT APPEAR
THAT WE WILL SEE ORGANIZED AREAS OF SNOWFALL...SO ACCUMULATIONS
SHOULD BE LIGHT WHERE THEY OCCUR AT ALL.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 51 25 44 23 / 20 0 0 0
HOBART OK 52 25 49 26 / 20 0 0 0
WICHITA FALLS TX 55 29 54 29 / 20 0 0 0
GAGE OK 49 20 48 24 / 20 0 0 0
PONCA CITY OK 47 20 37 17 / 20 10 0 0
DURANT OK 51 30 50 25 / 20 10 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PORTLAND
206 PM PST TUE FEB 17 2015
.SYNOPSIS...A STRONG RIDGE OF HIGH PRES OVER THE REGION WILL WEAKEN
SOME...ALLOWING A COUPLE OF WEAK SYSTEMS TO MOVE ACROSS THE PACIFIC
NW IN THE MIDDLE AND LATTER PART OF THE WEEK. OFFSHORE FLOW WILL
REDEVELOP OVER THE WEEKEND AGAIN AS THE RIDGE REBUILDS.
&&
.SHORT TERM...CURRENT THROUGH FRIDAY...VISIBLE SATELLITE IMAGERY
THIS AFTERNOON SHOWS JUST A COUPLE OF CIRRUS CLOUDS ACROSS THE
FORECAST AREA AND WE WILL CONTINUE TO EXPERIENCE ANOTHER WARM AND
SUNNY DAY. THIS PATTERN WILL SHIFT SLIGHTLY OVER THE NEXT 24 HOURS
AS HIGH PRESSURE BEGINS TO WEAKEN AND SOUTHERLY FLOW MOVES UP THE
COAST AND THEN INLAND. THE S/SW FLOW IS VERY APPARENT ON SATELLITE
TODAY DUE TO AN ASSOCIATED LOW STRATUS PUSH WHICH HAS MADE IT AS FAR
NORTH AS ABOUT TILLAMOOK OFFSHORE AND IS BEGINNING TO AFFECT THE
DOUGLAS COUNTY COAST ON LAND. THIS PUSH WILL CONTINUE NORTHWARD WITH
THE COAST ENGULFED IN CLOUDS BY WEDNESDAY MORNING AND MOSTLY CLOUDY
SKIES PUSHING INLAND DURING THE DAY WEDNESDAY. THE RAP APPEARS TO BE
DOING THE BEST JOB WITH TIMING AT THIS POINT.
THE FIRST OF A NUMBER OF WEAK SHORTWAVES MOVES THROUGH THE AREA
WEDNESDAY AND MAY HELP TO SQUEEZE OUT SOME DRIZZLE ALONG THE COAST.
WED NIGHT INTO THU MODELS INDICATE RIDGE BEGINNING TO REBUILD
OFFSHORE...WITH A MORE NORTHERLY TRACK FOR SHORTWAVES TO DROP
THROUGH THE REGION. MOISTURE AT THIS POINT REMAINS PRIMARILY IN THE
LOW LEVELS...BELOW ABOUT 6K FT...BUT THE TRACK OF THE SHORTWAVES
ALONG WITH BEST ONSHORE FLOW IN THE N INDICATE A CHANCE FOR SHOWERS
TO REMAIN ACROSS THE N PART OF THE FORECAST AREA. MODELS DIVERGE
SLIGHTLY FRIDAY REGARDING THE POSITION OF ONE LAST SHORTWAVE. THE
GFS BRINGS THE SHORTWAVE RIGHT OVER THE FORECAST AREA AND CALLS FOR
CONTINUING POPS THROUGH FRIDAY WHILE THE ECMWF PUSHES IT INTO
EASTERN OREGON AND SHOWS A DRY SOLUTION FRIDAY WEST OF THE CASCADES.
HAVE TRENDED TOWARD THE DRIER ECMWF AND LEFT OUT MENTIONABLE POPS
FRIDAY FOR THE TIME BEING. BOWEN
.LONG TERM...DRY NORTHERLY FLOW WILL MAINTAIN SUNNY AND SEASONAL
TEMPERATURES THIS WEEKEND. SATURDAY...FLOW ALOFT TURNS MORE
NORTHEASTERLY...WHICH WILL KEEP TEMPERATURES ON THE COOLER SIDE AS
WELL AS THE POSSIBILITY FOR BREEZY EAST WINDS THROUGH THE COLUMBIA
GORGE. HIGH PRESSURE SHIFTS INLAND...ALLOWING TEMPERATURES TO WARM
UP AGAIN INTO THE LOWER 60S SUNDAY INTO EARLY NEXT WEEK. MODELS ARE
REALLY TRYING TO BRING IN SOME PRECIPITATION...AND POSSIBLY SNOW TO
THE CASCADES BY MIDDLE OF NEXT WEEK...BUT DON`T HOLD YOUR BREATH
GIVEN THE EXTREMELY DRY ENVIRONMENT IN PLACE BY THAT TIME. /27
&&
.AVIATION...VFR INLAND THROUGH AT LEAST MOST OF THE EVENING. A
SOUTHERLY STRATUS/FIG SURGE IS NEARING NEWPORT WITH LIFR CIGS
EXPECTED TO ARRIVE AROUND THE 23Z TIME FRAME. MODEL DATA INDICATES THE
MARINE FRONT WILL BE DEEP ENOUGH TO SPILL OVER INTO THE WILLAMETTE
VALLEY AND BRING A SOUTHWESTERLY BURST OF WIND AND EVENTUALLY AN
IFR DECK TO KEUG BY LATER THIS EVENING. WILL SEE THE COASTAL DECK
CONTINUE TO PUSH NORTH AND REACH KAST CLOSER TO 05Z. HAVE HIGH
CONFIDENCE THE STRATUS WILL IMPACT KONP AND KAST BUT HAVE LESS
CONFIDENCE WITH REGARD TO THE SPECIFIC TIMING. AS THE OFFSHORE
SURFACE MOVES NORTH...WILL EVENTUALLY SEE THE WINDS SHIFT ONSHORE
OVERNIGHT AND BRING MOIST MARINE AIR TO THE INLAND TERMINALS. BOTH
NAM AND GFS TIME HEIGHT FORECASTS SHOW A 3000 FT CIG DEVELOPING AT
KHIO...KPDX...AND KTTD AROUND DAYBREAK. WILL PROBABLY NOT SEE
MUCH CHANGE ANYWHERE THROUGHOUT THE REST OF THE DAY AS AN OFFSHORE
COLD FRONT NEARS TOWARD THE AFTERNOON.
KPDX AND APPROACHES...VFR CONDITIONS UNDER EAST WINDS WILL
CONTINUE THROUGH THIS EVENING. WINDS WILL BEGIN TO SLACK OFF THIS
AFTERNOON AS THE SURFACE GRADIENT WEAKENS THEN TURN ONSHORE THIS
EVENING. THE ONSHORE WINDS WILL BRING COOL MOIST MARINE AIR ALONG
WITH CIGS AROUND 030 NEAR DAYBREAK. EXPECT LITTLE CHANGE ON
WEDNESDAY THEREAFTER. JBONK
&&
.MARINE...SURFACE LOW PRESSURE BRINGING SOUTHERLY STRATUS/FOG
SURGE UP THE COAST. CENTRAL WATERS ARE NEARLY COVERED AT THIS TIME
AND EXPECT THE NORTHERN WATERS WILL BE IN SIMILAR SHAPE BY MID
EVENING. SMALL CRAFT ADVISORY GUSTS WILL TRAIL THE LEADING EDGE OF
THE MARINE FRONT THIS EVENING AND INTO WEDNESDAY MORNING ALONG
WITH SOUTHERLY PRE FRONTAL WINDS AHEAD OF A WEAKENING COLD FRONT
WEDNESDAY EVENING. HIGH PRESSURE REBUILDS ALOFT AND AT THE SURFACE
THEREAFTER.A SURFACE THERMAL LOW DEVELOPS OVER SW OREGON AND NRN
CALIFORNIA TO BRING SUMMERTIME PATTERN OF GUSTY NORTH WINDS NEARER
SHORE AND MARGINALLY FLIRTING WITH SMALL CRAFT GUST CRITERIA OF 21
KT AT TIMES. SEAS ACROSS ALL WATERS APPEAR TO REMAIN 4 TO 7 FT FOR
THE BULK OF THE WEEK AHEAD BECOMING WIND WAVE DOMINATED AT TIMES.
/JBONK
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 9 PM THIS EVENING TO 9 AM
PST WEDNESDAY FOR WATERS FROM CAPE SHOALWATER WA TO CASCADE
HEAD OR FROM 10 TO 60 NM-WATERS FROM CASCADE HEAD TO
FLORENCE OR FROM 10 TO 60 NM.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
PLEASE SEE THE 18Z AVIATION FORECAST DISCUSSION BELOW.
&&
.AVIATION...
CLOUD COVER WILL GRADUALLY DECREASE ACROSS SOUTH CENTRAL TEXAS
THROUGH THE REMAINDER OF THIS AFTERNOON AND EARLY EVENING. BKN-OVC
CLOUD BASES AROUND 6K AGL WILL BECOME SCT BY LATE AFTERNOON AS
NORTHERLY WINDS DECREASE. SKIES SHOULD REMAIN CLEAR OVERNIGHT AS
WINDS BECOME LIGHT AND VARIABLE. FOR TOMORROW MORNING...LIGHT
SOUTHWEST TO WEST WINDS DEVELOP ALONG THE I-35 CORRIDOR...WHILE
LIGHT SOUTHEASTERLY WINDS DEVELOP AT KDRT.
&&
.PREV DISCUSSION... /ISSUED 935 AM CST TUE FEB 17 2015/
UPDATE...
ONLY RETURNS LEFT ON RADAR AT 930AM WERE LOCATED OVER
KARNES...DEWITT...AND LAVACA COUNTIES AND ON ITS WAY OUT. FOR THE
REST OF THE DAY...NOT EXPECTING ANY OTHER PRECIP AND CLOUDS WILL
BE ON THE DECREASE.
PERFORMED THE TYPICAL OBS BLEND INTO FORECAST HOURLIES AS WELL AS
REMOVING POPS FROM THE GRIDS FOR THE REMAINDER OF THE MORNING.
TB3
PREV DISCUSSION... /ISSUED 330 AM CST TUE FEB 17 2015/
SHORT TERM (TODAY THROUGH WEDNESDAY)...FINAL PIECE OF MID LEVEL
FORCING IN THE BASE OF THE TROUGH WILL ROTATE THROUGH THE CWA THIS
MORNING. HAVE FOLLOWED SLIGHTLY CLOSER TO THE HRRR THROUGH MIDDAY
GIVEN THE BETTER HANDLING OF WHERE PRECIP IS CURRENTLY FALLING
ACROSS SOUTHERN AREAS OF SJT AND MAF CWAS. THAT SAID...THERE IS A
SIGNIFICANT DRY LAYER BELOW 800MB ACROSS NORTHERN AND EASTERN
AREAS OF THE CWA...WHICH MAY PREVENT MUCH OF THE PRECIP FROM REACHING
THE GROUND (ESPECIALLY NORTH OF A LLANO TO AUSTIN TO SCHULLENBURG
LINE). WHERE PRECIP DOES REACH THE GROUND...COLUMN WILL BE COOL
ENOUGH ALONG AND WEST OF I-35 FOR LIGHT SLEET OR SNOW FLURRIES TO
MIX IN...ESPECIALLY ACROSS CENTRAL AND WESTERN HILL COUNTRY. THERE
WAS SOME -SN REPORTED EARLIER IN OZONA. GROUND TEMPERATURES FOR
MOST LOCATIONS WILL REMAIN ABOVE FREEZING AND THEREFORE GENERALLY
NO ACCUMULATION IS EXPECTED. HOWEVER...CAN NOT RULE OUT SOME VERY
PATCHY...ELEVATED SURFACES ACROSS THE NORTHERN HILL COUNTRY SEEING
SOME VERY LIGHT ACCUMULATIONS. OVERALL...NOT ENOUGH TO WARRANT AN
ADVISORY...BUT WILL ISSUE AN SPS.
CLEARING WILL TAKE PLACE WEST TO EAST THIS AFTERNOON AND EVENING.
CLEAR SKIES AND LIGHT WINDS...WITH LOW LEVEL RIDGE AXIS OVER THE
CWA...WILL LEAD TO A COLD NIGHT. LOWS WEDNESDAY MORNING DIP INTO
THE MID AND UPPER 20S ACROSS THE HILL COUNTRY AND LOW TO MID 30S
ELSEWHERE. HIGHS REBOUND INTO THE MID 60S UNDER SUNNY SKIES
WEDNESDAY.
JR
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...A WARMING TREND WILL
OCCUR THURSDAY THROUGH SATURDAY ACROSS THE CWA...WITH TEMPERATURES
BACK ABOVE NORMAL FRIDAY AND SATURDAY. LOW LEVEL RETURN FLOW WILL
DEVELOP OVER THE AREA ON THURSDAY...WITH A RETURN OF CLOUDS
THURSDAY NIGHT. PATCHY DRIZZLE AND ISOLATED SHOWERS POSSIBLE
MAINLY ALONG AND EAST OF I-35 FRIDAY AND SATURDAY. ECMWF AND GFS
IN GENERAL AGREEMENT WITH THE NEXT COLD FRONT MOVING THROUGH
SOUTH-CENTRAL TEXAS SUNDAY MORNING. ISENTROPIC UPGLIDE PATTERN
DEVELOPS OVER THE SHALLOW...COLD AIRMASS LEADING TO CLOUDY AND MUCH
COLDER CONDITIONS SUNDAY AND MONDAY ALONG WITH CHANCES FOR RAIN.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 51 35 65 40 71 / 20 0 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 49 29 64 35 69 / 20 0 0 0 0
NEW BRAUNFELS MUNI AIRPORT 50 32 66 38 72 / 20 0 0 0 0
BURNET MUNI AIRPORT 49 32 62 37 68 / 20 0 0 0 0
DEL RIO INTL AIRPORT 53 35 67 43 72 / 20 0 0 0 0
GEORGETOWN MUNI AIRPORT 51 31 64 37 68 / 20 0 0 0 0
HONDO MUNI AIRPORT 53 30 65 37 73 / 30 0 0 0 0
SAN MARCOS MUNI AIRPORT 51 31 65 37 71 / 20 0 0 0 0
LA GRANGE - FAYETTE REGIONAL 51 33 65 38 71 / 20 0 0 0 0
SAN ANTONIO INTL AIRPORT 52 33 65 40 71 / 30 0 0 0 0
STINSON MUNI AIRPORT 53 33 65 39 72 / 30 0 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...24
SYNOPTIC/GRIDS...03
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
1135 AM CST TUE FEB 17 2015
.AVIATION...
CEILINGS WILL REMAIN MOSTLY VFR AT THE TAF SITES WITH BRIEF
PERIODS OF MVFR CONTINUING AT KCDS AND KPVW. EXPECT CEILINGS TO
GRADUALLY INCREASE INTO THE VFR RANGE BY LATE THIS AFTERNOON AND
SHOULD SEE VFR CONDITIONS CONTINUE THROUGH THE OVERNIGHT HOURS
INTO WEDNESDAY.
&&
.PREV DISCUSSION... /ISSUED 626 AM CST TUE FEB 17 2015/
UPDATE...
DWINDLING SNOW ON RADAR THOUGH WITH LIGHT BANDS STILL TO FOLLOW
SEEMS IN LINE WITH LATEST RAP RUN. ALLOWED WINTER WEATHER ADVISORY
TO EXPIRE SOUTHWESTERN SOUTH PLAINS...DO NOT ANTICIPATE MORE THAN
A DUSTING REMAINDER OF THE AREA WITH SNOW MOSTLY ENDING BY 15Z.
RMCQUEEN
PREV DISCUSSION... /ISSUED 537 AM CST TUE FEB 17 2015/
AVIATION...
LIGHT SNOW WILL DWINDLE OVER THE NEXT COUPLE HOURS ACROSS THE SOUTHERN
SOUTH PLAINS INCLUDING KLBB WITH MVFR DOMINATING THROUGH 13Z OR 14Z.
BOTH KPVW AND KCDS APPEAR TOO DISTANT FROM THE BULK OF LIFT AND
DEEPER MOISTURE TO MENTION LINGERING SNOW CHANCES. DOWNSLOPE DRYING
WILL INCREASE MID TO LATE MORNING THOUGH STILL JUST ENOUGH MOISTURE
PERHAPS FOR A CUMULUS FIELD CONNECTED WITH MID LEVEL COOL POCKET
PASSING OVERHEAD. DRY AND VFR OVERNIGHT. RMCQUEEN
PREV DISCUSSION... /ISSUED 320 AM CST TUE FEB 17 2015/
SHORT TERM...
UPPER LEVEL IMPULSE TRANSLATING THROUGH THE AREA THIS MORNING RIGHT
ON SCHEDULE...AND DIRECTED MORE TOWARDS SOUTHERN ZONES WITH LIFT AND
SLIGHTLY DEEPER MOISTURE. THE MID LEVEL LIFT OVERNIGHT SO FAR HAS
SUCCEEDED IN MODEST TOP-DOWN MOISTENING AND SURFACE DEW-POINTS LATELY
HAVE RISEN OVER SOUTHERN ZONES AT LEAST TO THE POINT WHERE LIGHT
SNOW OR SNOW SHOWERS COULD REACH THE GROUND OVER A LARGER AREA. WITH
THAT...HOWEVER...THE RECENT RAP TRENDS SUPPORT ONLY A BRIEF
OPPORTUNITY FOR MOSTLY INSIGNIFICANT ACCUMULATIONS ACROSS MAINLY THE
SOUTHWESTERN SOUTH PLAINS OVER THE NEXT SEVERAL HOURS. THE
PREVIOUSLY ISSUED WINTER WEATHER ADVISORY IN THE SOUTHWESTERN SOUTH
PLAINS STILL SEEMS MORE THAN ADEQUATE BARRING UNEXPECTED LIFT
FURTHER NORTH OR EAST AND LIKELY WILL EXPIRE AT 12Z IF NOT EARLIER.
REMAINING LIGHT SNOW OR SNOW SHOWERS SHOULD FADE AROUND MID MORNING.
IN SPITE OF DRYING TRENDS ON BACK SIDE OF THIS WAVE...SHORT TERM
WRF/NAM CONTINUES TO INDICATE A WEAK CONVECTIVE SIGNAL AROUND MID
DAY INTO AT LEAST EARLY AFTERNOON AND WE HAVE RETAINED LIGHT RAIN
SHOWER POSSIBILITY THIS AREA. FURTHER DRYING AND CLEARING WILL OCCUR
LATER TODAY AND OVERNIGHT. MINOR CHANGES REMAINDER OF FORECAST.
RMCQUEEN
LONG TERM...
MEDIUM RANGE MODELS ARE BEGINNING TO SHOW A GLIMMER OF HOPE DEPICTING
A LITTLE MORE CONSISTENCY FOR THIS WEEKEND INTO EARLY NEXT WEEK.
BEFORE THEN...SURFACE LEE TROUGHING WILL RETURN ON THURSDAY AND
FRIDAY BUMPING TEMPERATURES BACK WELL ABOVE SEASONAL AVERAGES AS
PREVIOUSLY SEEN THIS WINTER SEASON ON THESE TYPES OF DAYS. A STRONG
COLD FRONT WILL MAKE ITS WAY INTO THE AREA ON SATURDAY AHEAD OF A
SURFACE RIDGE SPILLING INTO THE PLAINS AND MIDWEST YET AGAIN. MODELS
SHOW COLD 850MB TEMPERATURES BETWEEN -6 AND -9C BY MONDAY MORNING.
BOTH THE GFS AND ECMWF HAVE BEEN SHOWING VERY LIGHT QPF AMOUNTS ON
SUNDAY AND MONDAY NEXT WEEK. MOST OF THIS ACTIVITY IS DICTATED BY
ISENTROPIC LIFT WITH NEARLY ZONAL FLOW ALOFT. THESE TYPES OF
PATTERNS WHICH ARE DOMINATED BY UPGLIDE TEND TO BE VERY LIGHT IN
PRECIPITATION AMOUNTS AND ARE USUALLY DEFINED BY DRIZZLE. WITH THE
COLD AIR IN PLACE WE COULD SEE A WINTRY MIX OF FZRA/FZDZ EARLY NEXT
WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 44 22 55 29 / 20 0 0 0
TULIA 45 24 55 29 / 20 0 0 0
PLAINVIEW 47 25 56 30 / 20 0 0 0
LEVELLAND 47 26 61 31 / 30 0 0 0
LUBBOCK 48 26 60 31 / 20 0 0 0
DENVER CITY 47 27 62 31 / 30 0 0 0
BROWNFIELD 46 26 61 32 / 30 0 0 0
CHILDRESS 53 25 56 29 / 20 0 0 0
SPUR 50 28 60 32 / 20 0 0 0
ASPERMONT 52 28 62 33 / 20 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
310 PM CST TUE FEB 17 2015
.TONIGHT AND WEDNESDAY...CONFIDENCE - HIGH.
A POTENT 500MB SHORTWAVE TROUGH WILL SWING THROUGH THE REGION LATER
TONIGHT...WITH THE VORTICITY MAXIMA JUST TO OUR SOUTHWEST. THIS
SYSTEM WILL BE COINCIDENT WITH DECENT LOW LEVEL MOISTURE ADVECTION
AND GOOD 850MB COLD AIR ADVECTION. RAP BUFKIT SOUNDINGS INDICATE LOW
LEVEL LAPSE RATES WILL STEEPEN NEARLY DRY ADIABATICALLY THIS
EVENING. WEAK ISENTROPIC OMEGA WILL LIMIT SNOW AMOUNTS TONIGHT TO
BETWEEN A FEW TENTHS UP TO A HALF INCH ACROSS THE CWA.
THE BIG STORY WILL BE THE SINKING TEMPERATURES. 850MB TEMPERATURES
WILL REACH NEAR -28C OVER THE WESTERN HALF OF OUR CWA BY 18Z
WEDNESDAY. GUSTY NORTHWEST WINDS WILL KEEP WIND CHILLS DOWN...WITH
VALUES NEAR -20 FOR OUR FAR WESTERN TIER OF COUNTIES. WITH THE
INCREASE IN WIND SPEEDS AND GOOD COLD AIR ADVECTION...ISSUED A WIND
CHILL ADVISORY FOR SAUK...IOWA...AND LAFAYETTE COUNTIES BETWEEN 9Z
TO 16Z WED. TEMPERATURES WILL STAY COLD FOR WEDNESDAY WITH HIGHS
REACHING ONLY INTO THE SINGLE DIGITS ABOVE ZERO.
.WEDNESDAY NIGHT THROUGH FRIDAY...CONFIDENCE - HIGH.
ARCTIC COLD AIR WILL REMAIN ENTRENCHED OVER THE REGION THROUGH
THURSDAY NIGHT. 925H TEMPS FALL TO AROUND -25C WED NGT. HOWEVER
MIXY BOUNDARY LAYER AND POSSIBLE SOME LINGERING STRATUS WILL PREVENT
TEMPERATURE FREE FALL OVERNIGHT. NEVER THE LESS...STILL EXPECT
OVERNIGHT LOWS TO DIP TO BETWEEN -5 AND -12 CAUSING WIND CHILLS TO
DROP TO BETWEEN 20 AND 30 BELOW. A WIND CHILL ADVISORY WILL LIKELY
BE ISSUED ON WEDNESDAY FOR THIS PERIOD.
AN EVEN COLDER NIGHT LIES AHEAD FOR THURSDAY NIGHT AS LESS WIND AND
CLOUDS ARE EXPECTED. OVERNIGHT LOWS MAY DIP TO AS COLD AS -16 IN
LOW AREAS OF THE EASTERN CWA AWAY FROM THE SHORE. MORE QUESTIONABLE
HOWEVER WHETHER A WIND CHILL ADVISORY WILL BE NEEDED AS HIGH
PRESSURE RIDGE PASSING ACROSS SRN WI WILL RESULT IN DECOUPLING AND
LIGHT SFC WINDS OVERNIGHT.
CLOUDS WILL ALSO BEGIN TO INCREASE LATE IN THE NIGHT DUE TO UPSTREAM
STRONG WARM AIR ADVECTION. WEAK LAYER Q-VECTOR CONVERGENCE CLIPS
SRN WI WITH BETTER FORCING REMAINING TO THE NORTH. NEVER THE
LESS...WITH COLD DOME IN PLACE AND VIGOROUS WARM AIR
ADVECTION...WOULD NOT BE SURPRISED TO SEE MORE WIDESPREAD -SN
OVERSPREAD SRN WI ON FRI. HOWEVER FOR NOW DUE TO UNCERTAINTY WRT
STRENGTH OF LIFT AND COLUMN MOISTURE...WL KEEP POPS IN THE CHANCE
CATEGORY FOR NOW.
.FRIDAY NIGHT THROUGH SATURDAY NIGHT...CONFIDENCE - MEDIUM.
SLOWER EASTWARD PROGRESS OF SHORT WAVE TROF ACROSS WI FRIDAY NIGHT
SO WL CONTINUE SMALL POPS FOR -SN AS COLUMN MOISTURE EXTENDS TO
ABOUT 10K FT. TEMPORARY ZONAL TO SOUTHWEST FLOW ALOFT EARLY IN THE
WEEKEND WILL ALLOW AREA OF STRENGTHENING LOW PRESSURE ALONG
BAROCLINIC ZONE TO MOVE FROM THE SOUTHERN PLAINS INTO THE TN AND OH
VALLEY REGION ON SAT. ECMWF HAS BEEN TRENDING FARTHER SOUTH WITH
THE AFFECTS FROM THIS SYSTEM WHILE THE GFS HAS BEEN EDGING FARTHER
NORTH. ECMWF AND GFS CONVERGING ON SIMILAR SOLUTION WHICH KEEPS
SNOW SHIELD FROM THIS SYSTEM SOUTH OF SRN WI...MORE IN LINE WITH
LATEST CMC. WINDS MAY BRIEFLY TURN TO THE NORTHEAST AFTER TROUGH
PASSAGE FRIDAY NIGHT WHICH MAY BRING SOME LIGHT LAKE EFFECT TO THE
SOUTHEAST.
.SUNDAY THROUGH TUESDAY...CONFIDENCE - MEDIUM.
SHARPENING SHORT-WAVE TROF OVER ERN CONUS ASSOCIATED WITH ABOVE
SYSTEM WILL RESULT IN NORTHWEST STEERING FLOW AND COLDER TEMPS
RETURNING FOR SUNDAY AND LASTING INTO THE FIRST DAYS OF THE WEEK OF
THE 23RD. BOTH ECMWF AND GFS SHOW VIGOROUS SHORT WAVE TROF MOVING
SOUTHEAST AND AFFECTING THE WESTERN GTLAKES IN THE MON NGT/TUE
PERIOD. TEMPERATURES EARLY NEXT WEEK DO NOT LOOK TO BE AS COLD AS
WHAT IS EXPECTED THE NEXT SEVERAL DAYS...HOWEVER WILL REMAIN BELOW
NORMAL FOR LATE FEBRUARY.
&&
.AVIATION/00Z TAFS/...
500MB SHORTWAVE TROUGH WILL MOVE THROUGH THE REGION LATER
TONIGHT...SPARKING CHANCES OF LIGHT SNOW. A QUICK BURST OF MODERATE
SNOW IS POSSIBLE DUE TO THE STRENGTH OF THE POSITIVE VORTICITY
ADVECTION ASSOCIATED WITH THIS SHORTWAVE. IN GENERAL...VFR
CONDITIONS WILL PERSIST UNTIL THE LATE EVENING HOURS WHEN THE
SHORTWAVE TROUGH MOVES IN ABOUT 03Z TONIGHT. MVFR CONDITIONS WILL
BECOME MORE COMMON AS LIGHT SNOW DEVELOPS. WINDS WILL STAY FROM THE
NORTHWEST THROUGH THE EVENING AND OVERNIGHT HOURS. GUSTY WINDS OF UP
TO 25KTS ARE POSSIBLE TOMORROW AFTERNOON AS THE PRESSURE GRADIENT
TIGHTENS.
&&
.MARINE...
THE POTENTIAL FOR HIGHER WAVES ALONG THE NEARSHORE WILL INCREASE DUE
TO STRENGTHENING NORTHWEST WINDS...WITH GUSTS UP TO 25KTS DURING THE
DAY WEDNESDAY...ALONG WITH SOME BREAKS IN THE ICE ALONG THE LAKE MI
SHORE. DECIDED TO ISSUE A SMALL CRAFT ADVISORY IN EFFECT FROM 15Z
WED TO 00Z THURS DUE TO THE INCREASE IN WINDS. SOME LIGHT SNOW IS
ALSO A POTENTIAL LATER TONIGHT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY WIZ056-062-067 FROM 09Z/18 TO 15Z/18.
LM...SMALL CRAFT ADVISORY FROM 15Z/18 TO 00Z/19 LMZ643>646.
$$
TONIGHT AND WEDNESDAY/AVIATION/MARINE....JTS
WEDNESDAY NIGHT THROUGH TUESDAY...MBK