Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/11/15
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
847 PM MST TUE FEB 10 2015
.UPDATE...
ISSUED AT 847 PM MST TUE FEB 10 2015
THE COLD FRONT HAS RECENTLY MOVED THROUGH CHEYENNE AND IS
THEREFORE STILL ON TRACK TO REACH THE DENVER AREA BY ABOUT
MIDNIGHT. DEW POINTS HAVE BEEN RISING RAPIDLY ACROSS WYOMING AFTER
THE COLD FRONT...SO EXPECT THE AIRMASS TO MOISTEN RAPIDLY
DURING THE EARLY MORNING HOURS. A FEW RADAR ECHOES HAVE ALSO SHOWN
UP TO THE NORTH OF CHEYENNE IN THE PAST FEW SCANS. THE ADJUSTMENTS
THAT WERE MADE TO THE FORECAST EARLIER ARE STILL VALID...SO WILL
NOT MAKE ANY MORE CHANGES AT THIS POINT. SNOW AMOUNTS UP TO 6 OR 7
INCHES IN THE FOOTHILLS AND PARK COUNTY WILL BE CLOSE TO ADVISORY
CRITERIA...BUT WILL NOT ISSUE ANY HIGHLIGHTS AT THIS POINT SINCE
THE EVENT IS NOT EXPECTED TO BE THAT LONG IN DURATION. HRRR AND
RAP MODELS CONTINUE SHOWING THE SNOW COMING TO A RAPID END OVER
THE FOOTHILLS AND DENVER METRO AREA BETWEEN 5 AM AND 7 AM.
HOPEFULLY THINGS WILL CLEAR OUT SOON ENOUGH TO MINIMIZE THE IMPACT
ON THE MORNING COMMUTE.
UPDATE ISSUED AT 559 PM MST TUE FEB 10 2015
INITIAL PRECIPITATION THIS EVENING WILL LIKELY REMAIN CONFINED TO
POINTS SOUTH OF THE I-70 CORRIDOR AS AIRMASS FARTHER NORTH IS VERY
DRY AS EVIDENCED BY DEEP SUBCLOUD LAYER ON 00Z DENVER SOUNDING.
HAVE DELAYED PRECIP CHANCES FROM THE I-70 CORRIDOR NORTH THIS
EVENING. HOWEVER...WE ARE STILL ON TRACK FOR SNOW IN THE
OVERNIGHT PERIOD AFTER FRONTAL ARRIVAL. COLD FRONT IS NEAR CASPER
WYOMING WHICH MEANS ITS TIMED TO DENVER BY OR SHORTLY BEFORE
MIDNIGHT. THATS WHEN A MORE SIGNIFICANT UPSLOPE COMPONENT IS
EXPECTED TO DEVELOP...AND DECENT MOISTURE BEHIND THE FRONT.
AIRMASS IS QUITE UNSTABLE PER LATEST OBSERVED AND FORECAST
SOUNDINGS...SO SOME POTENTIAL FOR UPRIGHT CONVECTION. HAVE
INCREASED POPS AND SOME SNOW AMOUNTS IN/RIGHT NEXT TO THE
FOOTHILLS PER THIS AND LATEST HRRR/RAP OUTPUT. NOT A CLEAR CUT
SITUATION BY ANY MEANS AS THERE WILL LIKELY BE A VERY SHARP CUTOFF
IN PRECIPITATION AREA. ZONES 36 AND 37...SOUTHERN FOOTHILLS AND
PARK COUNTY MAY STILL NEED ADVISORY LATER THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 225 PM MST TUE FEB 10 2015
OVERALL TIMING AND TRACK OF THIS NEXT SYSTEM REMAIN IN TACT. UPPER
LEVEL JET MAX OVER NORTHERN COLORADO WL SHIFT EASTWARD OVERNIGHT
AS THE TROUGH AXIS SLIDES ACROSS THE REGION. MID LEVEL LAPSE RATES
NOT BAD...7-8C/KM. WINDS WL BECOME NORTHERLY THIS AFTN AS AN
INITIAL FRONT PUSHES INTO THE CWFA WITH A COLD PUSH THIS EVENING.
BEST COMBINATION OF SHALLOW UPSLOPE FOLLOWING THE FRONT AND
DYNAMICS ASSOCIATED WITH THE UPPER JET WILL BE IN ZONES 34..36..37
AND 41. HIGH RES MODELS GENERALLY IN THE 3-6 INCH RANGE FROM SNOW
TOTALS...WITH A COUPLE GOING WITH 8 INCHES. THE SYSTEM IS NOT
PARTICULARLY COLD INITIALLY WITH MIX OF RAIN AND SNOW BELOW 8
THOUSAND FEET THIS EVENING. WL HOLD OFF ON GOING WITH A WINTER
WEATHER ADVISORY AT THIS TIME...WL GO WITH AMOUNTS SLIGHTLY LESS
WITH 2 TO 5 INCHES PRIMARILY ZONE 36 WITH SLIGHTLY LESSER AMOUNTS
IN THE ADJACENT ZONES. AS FAR AS THE DENVER AREA IS CONCERNED...WL
GO WITH LIKELY POPS HEAVIEST SOUTH OF INTERSTATE 70 WITH 1-3
INCHES IN THE GRIDS. AREAS NORTH OF I70 WL LIKELY SEE LESSER
AMOUNTS OF AN INCH OR LESS. ON WEDNESDAY...THE SYSTEM WL EXIT TO
THE EAST WITH LOW CLOUDS LINGERING THROUGH THE MORNING HOURS. THE
MID AND UPPER LEVELS WILL BE DRIER WITH TEMPERATURES CLOSER TO
SEASONAL NORMALS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 225 PM MST TUE FEB 10 2015
LARGE UPPER RIDGE ANCHORED OVER THE WESTERN CONUS WILL KEEP THE
CWA UNDER A RELATIVELY COOL NORTHWESTERLY FLOW THROUGH SATURDAY.
THIS WILL KEEP TEMPERATURES WELL BELOW RECORD LEVELS...BUT AMPLE
SUNSHINE AND LIGHT DOWNSLOPE FLOW SHOULD RESULT IN TEMPS SEVERAL
DEGS ABOVE AVERAGE. OVER THE WEEKEND...MODELS SHOW THE UPPER RIDGE
RETROGRADING OVER THE EASTERN PACIFIC WHICH ALLOWS A WEAK
SHORTWAVE TROUGH TO SWEEP DOWN FROM THE PACIFIC NORTHWEST. MODELS
PARTICULARLY THE GFS SHOWS STEADY AMPLIFICATION IN THIS WAVE ON
ITS WAY ACRS SRN IDAHO AND WRN WY LATE IN WEEKEND. MEANWHILE DOWN
ACRS N- CNTRL AND NERN COLORADO...MID AND HIGH-LEVEL MOISTURE OUT
AHEAD OF THIS WAVE WILL CAUSE A GRADUAL INCREASE IN CLOUDS
RESULTING IN A SLIGHT DIG IN TEMPERATURES ON SUNDAY...BUT NO
PRECIP YET. BY MONDAY MORNING BOTH THE GFS AND ECMWF SHOW THIS
TROUGH STRENGTHENING OVER WYOMING. GFS ALSO SHOWS A COLD FRONT
RACING SOUTH ACRS ERN COLORADO...WHILE THE EC STILL SHOWS THE
FRONT UP OVER CNTRL WYOMING. DURING THE DAY MONDAY INTO MONDAY
NIGHT...THE GFS SWINGS THIS SYSTEM OVER THE FCST AREA...WHILE THE
EC SWINGS THIS SYSTEM JUST THE NORTH AND EAST OF THE AREA DURING
THE SAME PERIOD. FOR NOW WILL INTRODUCE LOW POPS EVERYWHERE AND
DROP TEMPS TO NEAR AVERAGE LEVELS.
&&
.AVIATION...(FOR THE TAFS THROUGH 06Z WEDNESDAY EVENING)
ISSUED AT 847 PM MST TUE FEB 10 2015
STILL EXPECT CEILINGS TO COME DOWN RAPIDLY AFTER THE FRONTAL
PASSAGE AROUND 06Z. WILL PROBABLY GO WITH PREVAILING IFR
CONDITIONS FOR THE 07Z-11Z PERIOD. CONDITIONS WILL PROBABLY BE
LOWER AT KBJC AND KAPA THAN AT KDEN...SINCE THE UPSLOPE
CONTRIBUTION TO CLOUDS AND SNOWFALL WILL BE MOST ENHANCED NEAR THE
FOOTHILLS. RAPID IMPROVEMENT IN CONDITIONS IS EXPECTED THROUGH THE
MORNING TOMORROW.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DANKERS
SHORT TERM...COOPER
LONG TERM...BAKER
AVIATION...DANKERS
AREA FORECAST DISCUSSION
NWS NEW YORK NY
410 PM EST MON FEB 9 2015
.SYNOPSIS...
LOW PRESSURE WILL TRACK SOUTHEAST OF LONG ISLAND THROUGH TONIGHT.
HIGH PRESSURE BUILDS IN FROM THE NORTH TUESDAY THROUGH
WEDNESDAY...GIVING WAY TO LOW PRESSURE WEDNESDAY NIGHT AND
THURSDAY. THE LOW DEEPENS AS IT MOVES EAST THURSDAY NIGHT AND
FRIDAY. ANOTHER AREA OF LOW PRESSURE MAY IMPACT THE AREA THIS
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
MUCH OF THE STEADIEST WINTRY PRECIPITATION HAS ENDED ACROSS THE
REGION THIS AFTERNOON. HAVE CONTINUED WITH LIKELY POPS THROUGH
THIS EVENING AS WEAK ENERGY ALOFT AND SHORTWAVE TROUGH MOVES
ACROSS THE AREA. LIFT IS OVERALL WEAK HOWEVER SO NOT ANTICIPATING
ANY SIGNIFICANT PRECIPITATION. AS THE SURFACE LOW BEGINS TO
DEEPEN OFF THE SOUTHEAST COAST TONIGHT...THE BEST LIFT WILL FOCUS
SOUTH OF THE CWA.
THE COLUMN ALOFT WILL CONTINUE TO COOL THROUGH THIS EVENING SO ANY
PRECIPITATION THAT FALLS WILL BE PREDOMINATELY SNOW. ACROSS
SOUTHERN ZONES...LATEST THERMAL PROFILES FROM THE HRRR ARE INDICATING
THE BEST LIFT MAY OCCUR BELOW THE SNOW GROWTH ZONE ACROSS SOUTHERN
ZONES...SO SLEET OR FREEZING RAIN IS STILL POSSIBLE. ANY ICE/SLEET
WILL BE LIGHT WITH AROUND A TRACE TO A FEW HUNDREDTHS AT MOST. NEW
SNOWFALL ACCUMULATION WILL BE UP TO AN INCH.
DUE TO THE POTENTIAL FOR LIGHT ICE THIS EVENING ACROSS SOUTHERN
ZONES...SOME ADDITIONAL SNOW ACROSS THE INTERIOR...AND
COLLABORATION WITH SURROUNDING OFFICES...THE WINTER WEATHER
ADVISORY CONTINUES. THE ADVISORY NOW EXPIRES AT MIDNIGHT. IF LITTLE OR NO
PRECIPITATION FALLS...THE ADVISORY COULD BE CANCELED SOONER.
AFTER MIDNIGHT...DRIER AIR WORKS ITS WAY INTO THE REGION SO ANY
LINGERING PRECIPITATION WILL END.
A BLEND OF MAV/MET GUIDANCE ACCEPTED FOR LOWS TONIGHT.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
HIGH PRESSURE BUILDS OVER THE TRI-STATE FROM SOUTHERN CANADA AS
LOW PRESSURE DEEPENS OFF THE SOUTHEAST COAST. CLOUDS WILL SLOWLY
CLEAR FROM NORTHWEST TO SOUTHEAST ACROSS THE AREA. PRESSURE
GRADIENT BETWEEN THE DEEPENING LOW AND BUILDING HIGH PRESSURE WILL
KEEP BREEZY CONDITIONS...ESPECIALLY NEAR THE COAST. PARTLY CLOUDY
SKIES AND BREEZY CONDITIONS WILL CONTINUE TUESDAY NIGHT.
TEMPERATURES FOR THIS PERIOD ARE A BLEND OF MAV/MET GUIDANCE. WIND
CHILLS TUESDAY NIGHT WILL FALL INTO THE SINGLE DIGITS FOR MOST
LOCATIONS...AND LOW TEENS IN THE NEW YORK CITY METRO.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
ACTIVE WINTER PATTERN WILL CONTINUE THROUGH THIS TIME FRAME. BITTER
COLD EXPECTED ALONG WITH POTENTIAL FOR TWO STORM SYSTEMS TO IMPACT
THE AREA.
HIGH PRESSURE WEDNESDAY BRIEFLY BUILDS. HOWEVER...NEXT VIGOROUS
SHORTWAVE THAT ORIGINATES FROM THE POLE DIVES DOWN ACROSS THE GREAT
LAKES REGION...WITH CLIPPER LOW ACCOMPANYING IT AT THE SFC. THE LOW
PASSES ACROSS THE GREAT LAKES REGION WEDNESDAY NIGHT...MOVING TOWARD
THE AREA EARLY THURSDAY. AS THE AMPLIFIED TROUGH MOVES ACROSS THE
NORTHEAST...THE LOW DEEPENS CONSIDERABLY OVER THE GULF STREAM. THERE
ARE DIFFERENCES WITH THE PROGRESSION OF THIS LOW...DUE TO SLIGHT
DIFFERENCES ALOFT PER LATEST OPERATIONAL GFS AND 12Z ECMWF.
AS FOR SENSIBLE WEATHER...WILL INCREASE POPS/COVERAGE TO LIKELY IN
SNOW THURSDAY...WITH POTENTIAL FOR ACCUMULATING SNOW THURSDAY
THROUGH THURSDAY EVENING. BETTER CHANCE THURSDAY NIGHT WOULD BE
ACROSS EASTERN LOCATIONS.
THEN...UPPER TROUGH MOVES EAST...ONLY TO GIVE WAY TO NEXT
SHORTWAVE...WHICH COULD BE DEEPER...THIS WEEKEND.
ANOTHER SFC LOW AHEAD OF THIS TROUGH DIVES ACROSS THE GREAT LAKES
REGION...ONLY TO DEEPEN SOMEWHERE TO THE SOUTH THIS WEEKEND.
OVERALL...COLD AIR WILL PREVAIL. WED AND THU WILL BE COLD...BUT WILL
FEEL WARM COMPARED TO WHAT IS IN STORE FOR OUR AREA FRIDAY THROUGH
MONDAY. FRIGID TEMPS CAN BE EXPECTED...WITH TEMPS AVERAGING AT LEAST
20 DEGREES BELOW NORMAL. DANGEROUS WIND CHILLS ARE ALSO EXPECTED
ESPECIALLY THU NIGHT INTO FRIDAY...AND AGAIN SAT NIGHT INTO SUNDAY
WITH GUSTY NW WINDS.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
THIS REMAINS A DISORGANIZED EVENT WHICH WILL FEATURE MAINLY LIGHT
SNOW/FLURRIES...MIXED WITH -FZRA AT TIMES PRIMARILY NORTH OF THE NYC
TERMINALS. THERE COULD ALSO BE SOME PATCHY -FZRA/FZDZ DURING THE
EVENING HOURS WITH DEEP MOISTURE AND WEAK LIFT. CONFIDENCE IS TOO
LOW TO MENTION IN THE TAFS AT THIS TIME.
GENERALLY MVFR CIGS WITH NE WINDS AT 10-15 G20KT.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: PATCHY FZRA/FZDZ POSSIBLE THIS EVENING.
KLGA FCSTER COMMENTS: PATCHY FZRA/FZDZ POSSIBLE THIS EVENING.
KEWR FCSTER COMMENTS: PATCHY FZRA/FZDZ POSSIBLE THIS EVENING.
KTEB FCSTER COMMENTS: PATCHY FZRA/FZDZ POSSIBLE THIS EVENING.
KHPN FCSTER COMMENTS: OCCASIONAL IFR POSSIBLE THROUGH THIS
EVENING.
KISP FCSTER COMMENTS: PATCHY FZRA/FZDZ POSSIBLE THIS EVENING.
.OUTLOOK FOR 21Z TUE THROUGH SAT...
.TUE AFT...VFR. NORTH GUSTS AROUND 20KT.
.TUE NIGHT-WED...VFR.
.THU...MVFR TO IFR POSSIBLE IN SNOW...ESPECIALLY EASTERN
TERMINALS. .
.THU NIGHT-FRI...VFR. NW WINDS G40KT...DIMINISHING FRI NIGHT.
.SAT...VFR.
&&
.MARINE...
GALES ARE EXPECTED ON THE OCEAN WATERS TONIGHT THROUGH TUESDAY
AFTERNOON...WITH SCA CONDITIONS ON NON-OCEAN WATERS. HAVE EXTENDED
THE GALE WARNING AND SCA THROUGH 19Z TUESDAY. WINDS AND SEAS WILL
CONTINUE TO INCREASE TONIGHT AS PRESSURE GRADIENT TIGHTENS BETWEEN
HIGH PRESSURE TO THE NORTH...AND LOW PRESSURE TO THE SOUTH. SEAS
ON THE OCEAN WILL BE 6 TO 9 FT THROUGH TUESDAY AFTERNOON.
WINDS WILL LIKELY FALL BELOW GALES ON TUESDAY AFTERNOON SO A SCA
WILL LIKELY BE NEEDED TUESDAY AFTERNOON AND EVENING ON THE OCEAN. SEAS
WILL ALSO DECREASE TO BETWEEN 5 TO 7 FT TUESDAY AFTERNOON AND
EVENING.ON NON-OCEAN WATERS...WINDS AND SEAS WILL LIKELY FALL
BELOW SCA LEVELS AFTER 19Z TUESDAY.
DEEP LOW PRESSURE WELL TO THE EAST EARLY WEDNESDAY WILL GIVE WAY
TO BRIEF HIGH PRESSURE. THEN...LOW PRESSURE QUICKLY APPROACHES THE
WATERS WEDNESDAY NIGHT...WITH A COLD FRONT MOVING THROUGH EARLY
THURSDAY. LOW PRESSURE DEEPENS TO THE EAST THURSDAY NIGHT...WITH
GALE CONDITIONS LIKELY THURSDAY NIGHT INTO FRIDAY. THIS LOW
DEPARTS TO THE NORTHEAST LATE FRIDAY. THEN...YET ANOTHER LOW
APPROACHES SATURDAY...POSSIBLY DEEPENING LATE.
ROUGH SEA CONDITIONS ARE EXPECTED THROUGH MUCH OF THE MID TO LATE
WEEK PERIOD.
&&
.HYDROLOGY...
NO HYDROLOGIC PROBLEMS ARE EXPECTED THROUGH WEDNESDAY NIGHT. UP
TO A QUARTER OF AN INCH...LOCALLY HIGHER...OF LIQUID EQUIVALENT IS
POSSIBLE THURSDAY AND THURSDAY NIGHT. THIS WILL BE IN THE FORM OF
SNOW...SO NO HYDROLOGIC IMPACTS ARE ANTICIPATED.
&&
.EQUIPMENT...
NEW YORK CITY ALL HAZARDS RADIO...FREQUENCY 162.550 MHZ...IS OFF
THE AIR DUE TO A TELEPHONE LINE COMMUNICATIONS FAILURE.
TECHNICIANS ARE WORKING ON THE ISSUE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
CTZ005>012.
NY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
NYZ067>075-078>081-176>179.
NJ...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NJZ002-
004-006-103>108.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EST TUESDAY FOR ANZ330-335-338-
340-345.
GALE WARNING UNTIL 2 PM EST TUESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...DS/PW
NEAR TERM...DS
SHORT TERM...DS
LONG TERM...PW
AVIATION...DW
MARINE...DS/PW
HYDROLOGY...DS/PW
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
703 AM EST MON FEB 9 2015
.SYNOPSIS...
LOW PRESSURE WILL TRACK OFFSHORE SOUTHEAST OF LONG ISLAND THROUGH
TONIGHT. HIGH PRESSURE BUILDS IN FROM THE NORTH TUESDAY AND LASTS
THROUGH WEDNESDAY. LOW PRESSURE WILL MOVE ACROSS THE REGION
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. HIGH PRESSURE BUILDS IN
FOR FRIDAY. ANOTHER LOW MOVES INTO THE REGION SATURDAY AND
SATURDAY NIGHT...WITH HIGH PRESSURE FOLLOWING SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WILL BE MOVING IN SOUTHEAST CANADA WHILE LOW
PRESSURE APPROACHES FROM THE DELMARVA. LOW PRESSURE STAYS SOUTH OF
THE REGION AND HIGH PRESSURE STAYS WELL NORTH OF THE REGION
THROUGH THE DAY TODAY. AS LOW PRESSURE MOVES OVER THE ATLANTIC
SOME SLIGHT STRENGTHENING AND DEEPENING IS EXPECTED OUT AHEAD OF
THE MID AND UPPER LEVEL TROUGH...RESULTING IN AN EXPANSION OF
PRECIP COVERAGE. THE FIRST HALF OF THIS EVENT IS THROUGH THIS
MORNING WITH THE WARM NOSE ALOFT MAKING FOR FREEZING RAIN AT THE
COAST WITH SNOW...OCCASIONALLY MIXING WITH SLEET AND FREEZING
RAIN...ACROSS THE INTERIOR. THE SECOND HALF OF THIS EVENT WILL BE
CHANGING PRIMARILY TO SNOW AND SLEET AT THE COAST WITH SOME
LEFTOVER FREEZING RAIN AS THE WARM NOSE WEAKENS THIS AFTERNOON AND
COLD AIR ADVECTION TAKES OVER.
00Z RUNS OF NAM AND ECMWF DEPICT BETTER QPF TO OBSERVED RADAR TRENDS
THAN THE CMC AND GFS. 00Z ECMWF SHOWING QPF THAT WOULD AGREE WITH
THE REFLECTIVITY FORECAST OF THE 04Z HRRR SO WILL BE RELYING MORE
UPON THE ECMWF FOR POP TRENDS.
MUCH OF THE SNOW AND ICE WILL BE ONGOING UNTIL AROUND 18Z FROM A
GENERAL MODEL CONSENSUS AND MODEL BUFKIT SOUNDING BOUNDARY LAYER
ANALYSIS. THE SIGNATURES WITHIN MSLP SHOW PROMINENT COLD AIR
DAMMING. THE NE WINDS AT THE SURFACE WILL BE INCREASING WITH A
PERSISTENT WARM NOSE AROUND 900MB...HELPING SET UP FOR PROLONGED
FREEZING RAIN ACROSS NYC/COASTAL AREAS OF NE NJ AND SOUTHERN PARTS
OF THE LOWER HUDSON VALLEY AS WELL AS LONG ISLAND. FARTHER NORTH THE
WARM NOSE WILL MAKE ITS APPEARANCE BRIEFLY BUT SNOW WILL BE DOMINANT
BEFORE AND AFTER THAT TIME.
WHAT MAKES THIS A CHALLENGING FORECAST IS HOW WELL THE MODELS ARE
DEPICTING THE WARM NOSE AND ITS DEPTH RELATIVE TO COLDER AIR NEAR
THE SURFACE. SLEET COULD VERY WELL BE MORE OF A POSSIBILITY WITH
LESS OF A WARM NOSE BUT A THICKER NEAR SURFACE LAYER BELOW
FREEZING. THIS OCCURRED ACROSS PARTS OF NYC AND WESTERN LONG
ISLAND THIS MORNING AS CONVEYED BY THE BRIGHT BANDING SIGNATURE
WITHIN THE OKX DOPPLER RADAR REFLECTIVITY.
QPF IS ALWAYS AN AREA OF LARGER UNCERTAINTY WITHIN THE FORECAST
MODELS AND WHILE IT COULD TREND HIGHER IF GFS IS CORRECT...NAM AND
ECMWF AS AFOREMENTIONED ARE BETTER MATCHING UP WITH OBSERVATIONS IN
RADAR SO THIS WOULD MAKE FOR LIGHTER QPF...A GENERAL 0.2 TO 0.5
LIQUID EQUIVALENT WITH AROUND 0.2 FOR NYC/URBAN NE NJ/LONG ISLAND
AND GRADUALLY HIGHER TOTALS TO THE NORTH. SO WITH THE
ICE...ACCRETION WILL BE MAINLY BETWEEN 0.1 TO 0.2 INCH WHILE SNOW
ACROSS THE INTERIOR WILL BE 4 TO 6 INCHES STORM TOTAL...THIS BEING
SPREAD OUT ACROSS NEARLY A 24 HOUR PERIOD.
FOR HIGH TEMPS TODAY...ECMWF AND NAM12 RAW 2M TEMPS WERE
USED...YIELDING MID 20S TO AROUND 30 FOR MUCH OF THE REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
THE SECOND HALF OF THIS WINTER EVENT WILL BE ONGOING WITH THE LOW
PRESSURE IN THE ATLANTIC SLIGHTLY DEEPENING AHEAD OF THE MID AND
UPPER LEVEL TROUGH AS HIGH PRESSURE WEAKENS IN SOUTHEAST CANADA.
THE WEAKENING PRESSURE GRADIENT WILL LEAD TO WINDS DECREASING.
THERE WILL BE MAINLY SNOW LEFTOVER GOING THROUGH THE EVENING WITH
PERHAPS ANOTHER 1-2 INCHES. WITH THE COLD AIR ADVECTION CONTINUING
WITHIN THE ATMOSPHERE AND RETENTION OF ENOUGH MOISTURE AND HENCE
ICE NUCLEI...NO FURTHER ICE ACCRETION IS EXPECTED WITH
PRECIPITATION TYPE STAYING AS MAINLY SNOW. LOWS WERE A BLEND OF
NAM12 2M TEMPS AND GMOS.
FOR TUESDAY...ANOTHER STRONG CANADIAN HIGH BUILDS IN FROM THE
NORTHWEST. THIS WILL REINFORCE THE COLD AIR ADVECTION BUT WITH MORE
SUN...TEMPERATURES WILL BE RELATIVELY WARMER THAN THE PREVIOUS DAY.
HIGHS FORECAST ARE IN THE LOWER 30S FOR MOST LOCATIONS. THESE WERE
TAKEN FROM 2/3 GMOS AND 1/3 NAM12 2M TEMPERATURES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
AN ACTIVE UPPER NORTHERN STREAM WILL BRING A COUPLE OF SHORTWAVES
THROUGH THE REGION WEDNESDAY NIGHT NIGHT AND SATURDAY NIGHT. WHILE
AT THE SURFACE ONE LOW IS EXPECTED TO MOVE ACROSS THE AREA WEDNESDAY
NIGHT INTO THURSDAY...MOVING OFF THE DELMARVA THURSDAY NIGHT AND
INTENSIFY...AND MOVE TO THE NORTHEAST BY FRIDAY MORNING. COLD AIR
WILL BE IN PLACE AND AN ALL LIGHT SNOW EVENT IS FORECAST. AT THIS
TIME WITH THE STORM QUICK MOVING A COUPLE OF INCHES OF SNOW
ACCUMULATION IS POSSIBLE.
MUCH COLDER AIR MOVES INTO THE AREA BEHIND THE DEPARTING LOW
THURSDAY NIGHT INTO FRIDAY NIGHT AS HIGH PRESSURE BUILDS TO THE
WEST. THE HIGH QUICKLY WEAKENS AS ANOTHER SURFACE LOW MOVES OUT OF
CENTRAL CANADA AND TRACKS WEST AND SOUTH...MOVING OFF THE MID
ATLANTIC COAST SATURDAY NIGHT. THE AREA WILL BE ON THE EDGE OF THE
PRECIPITATION SHIELD WITH THIS LOW...WITH RATHER LIGHT
PRECIPITATION...AND WILL HAVE ONLY SLIGHT CHANCE POPS LATE SATURDAY
INTO SATURDAY NIGHT. WITH A COLD AIRMASS IN PLACE AS THE LOW TRACKS
THROUGH LIGHT SNOW IS EXPECTED. THE COLD AIR WILL BE RE ENFORCED
BEHIND THE LOW WITH TEMPERATURES POSSIBLY THE COLDEST OF THE WINTER
SEASON SUNDAY NIGHT...WITH LOWS BELOW ZERO ACROSS MUCH OF THE
INLAND...AND APPROACHING ZERO NEAR THE COAST.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
HIGH IMPACT WINTER WEATHER EVENT EXPECTED IN THE NY METRO TODAY
WAVES LOW PRESSURE WILL MOVE ALONG A COLD FRONT TO THE SOUTH.
MAINLY LOW END MVFR TO IFR. WINTRY MIX CHANGES TO SNOW THIS AFTN
FOR MOST TERMINALS. A LIGHT PCPN EVENT OVERALL...BUT POTENTIALLY
HIGH IMPACT DUE TO THE PROLONGED PERIOD OF LIGHT FROZEN/FREEZING
PCPN.
NE WINDS NEAR 15 KT WITH GUSTS JUST OVER 20 KT.
FORECAST SNOW TOTALS...
KJFK/KLGA/KEWR/KTEB/ISP...1-2 INCHES...WITH UP TO AROUND A TENTH OF
AN INCH OF ICE.
KHPN/KBDR/KGON...2-3 INCHES...WITH UP TO AROUND A TENTH OF AN INCH
OF ICE.
KSWF...4-7 INCHES.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: CHC TEMPO OR PREVAILING MVFR TODAY. CHANGE
TO SNOW MAY BE FORECAST TO OCCUR AN HOUR OR TWO TOO LATE.
KLGA FCSTER COMMENTS: CHC TEMPO OR PREVAILING MVFR TODAY. SNOW MIGHT
NOT BE PREVALENT IN THE WINTRY MIX THIS MORNING. CHANGE TO SNOW
MAY BE FORECAST TO OCCUR AN HOUR OR TWO TOO LATE.
KEWR FCSTER COMMENTS: CHC TEMPO OR PREVAILING MVFR TODAY. CHANGE
TO SNOW MAY BE FORECAST TO OCCUR AN HOUR OR TWO TOO LATE.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: CHC TEMPO OR PREVAILING MVFR TODAY. SNOW MIGHT
NOT BE PREVALENT IN THE WINTRY MIX BEFORE 15-16Z. CHANGE TO SNOW
MAY BE FORECAST TO OCCUR AN HOUR OR TWO TOO LATE.
KHPN FCSTER COMMENTS: CHC TEMPO OR PREVAILING MVFR TODAY. .
KISP FCSTER COMMENTS: SLEET POSSIBLE IN THE WINTRY MIX BEFORE 15Z.
CHANGE TO SNOW MAY BE FORECAST TO OCCUR AN HOUR OR TWO TOO LATE.
.OUTLOOK FOR 12Z TUE THROUGH FRI...
.TUE...MVFR CIGS AM. VFR PM. NORTH GUSTS AROUND 20KT.
.TUE NIGHT...VFR.
.WED...MVFR CIGS.
.THU...MVFR TO IFR IN LIGHT SNOW...BECOMING VFR LATE WITH
NW WINDS G40KT.
.THU NIGHT-FRI...VFR. NW WINDS G40KT...DIMINISHING FRI NIGHT.
&&
.MARINE...
INCREASING WINDS AND SEAS AS PRESSURE GRADIENT TIGHTENS BETWEEN
HIGH PRESSURE NORTH OF THE WATERS AND LOW PRESSURE SOUTH OF THE
WATERS. GALES FOR THE OCEAN TODAY AND TONIGHT...COULD DIMINISH
EARLIER TONIGHT THAN FORECAST. WIND GUSTS WERE PRETTY CLOSE TO THE
THRESHOLD SO LEFT THE END TIMING AS BEFORE AND UPGRADED TO GALE
WARNINGS FOR THE OCEAN. SEAS ON THE OCEAN INCREASE TO 6 TO 9 FT
LATER THIS AFTERNOON AND INTO THIS EVENING.
NON-OCEAN WATERS WILL HAVE SCA CONDITIONS THROUGH TONIGHT. THESE
COULD LINGER ON TUESDAY BUT A DOWNWARD TREND IS FORECAST AND
CONDITIONS SEEMED MARGINAL SO SCA WAS NOT YET EXTENDED THROUGH
TUESDAY.
SMALL CRAFT WIND GUSTS AND SEAS REMAIN TUESDAY NIGHT INTO
WEDNESDAY ON THE OCEAN WATERS WHILE THE REMAINDER OF THE FORECAST
WATERS ARE BELOW ADVISORY LEVELS. LONG TERM SMALL CRAFT SEAS ON
THE OCEAN REMAIN INTO FRIDAY NIGHT. LOW PRESSURE DEEPENING EAST OF
THE WATERS THURSDAY NIGHT INTO FRIDAY WILL PRODUCE SMALL CRAFT
GUSTS ON THE OCEAN AND EASTERN FORECAST WATERS. WITH THE LOW
MOVING TO THE NORTHEAST FRIDAY NIGHT INTO SATURDAY WIND GUSTS WILL
DIMINISH TO BELOW SMALL CRAFT. SEAS ALSO DIMINISH BELOW SMALL
CRAFT ON THE OCEAN BY LATE FRIDAY NIGHT INTO EARLY SATURDAY...AND
REMAIN BELOW THROUGH SATURDAY.
&&
.HYDROLOGY...
LIQUID EQUIVALENT AMOUNTS OF AROUND 0.1 TO 0.5 INCH ARE EXPECTED
WITH THIS SYSTEM THROUGH TONIGHT. NO HYDROLOGIC PROBLEMS ARE
EXPECTED.
A TENTH OR TWO OF LIQUID EQUIVALENT IS POSSIBLE FROM WEDNESDAY
NIGHT THROUGH THURSDAY NIGHT...FALLING AS LIGHT SNOW.
&&
.EQUIPMENT...
NEW YORK CITY ALL HAZARDS RADIO...FREQUENCY 162.550 MHZ...IS OFF
THE AIR DUE TO A TELEPHONE LINE COMMUNICATIONS FAILURE.
TECHNICIANS ARE WORKING ON THE ISSUE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 6 AM EST TUESDAY FOR CTZ005>012.
NY...WINTER WEATHER ADVISORY UNTIL 6 AM EST TUESDAY FOR NYZ067>075-
078>081-176>179.
NJ...WINTER WEATHER ADVISORY UNTIL 6 AM EST TUESDAY FOR NJZ002-004-
006-103>108.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR ANZ330-335-338-
340-345.
GALE WARNING UNTIL 6 AM EST TUESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...JM/MET
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...MET
AVIATION...JC
MARINE...JM/MET
HYDROLOGY...JM/MET
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
441 AM EST MON FEB 9 2015
.SYNOPSIS...
LOW PRESSURE WILL TRACK OFFSHORE SOUTHEAST OF LONG ISLAND THROUGH
TONIGHT. HIGH PRESSURE BUILDS IN FROM THE NORTH TUESDAY AND LASTS
THROUGH WEDNESDAY. LOW PRESSURE WILL MOVE ACROSS THE REGION
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. HIGH PRESSURE BUILDS IN
FOR FRIDAY. ANOTHER LOW MOVES INTO THE REGION SATURDAY AND
SATURDAY NIGHT...WITH HIGH PRESSURE FOLLOWING SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WILL BE MOVING IN SOUTHEAST CANADA WHILE LOW
PRESSURE APPROACHES FROM THE DELMARVA. LOW PRESSURE STAYS SOUTH OF
THE REGION AND HIGH PRESSURE STAYS WELL NORTH OF THE REGION
THROUGH THE DAY TODAY. AS LOW PRESSURE MOVES OVER THE ATLANTIC
SOME SLIGHT STRENGTHENING AND DEEPENING IS EXPECTED OUT AHEAD OF
THE MID AND UPPER LEVEL TROUGH...RESULTING IN AN EXPANSION OF
PRECIP COVERAGE. THE FIRST HALF OF THIS EVENT IS THROUGH THIS
MORNING WITH THE WARM NOSE ALOFT MAKING FOR FREEZING RAIN AT THE
COAST WITH SNOW ACROSS THE INTERIOR. THE SECOND HALF OF THIS EVENT
WILL BE CHANGING PRIMARILY TO SNOW AND SLEET AT THE COAST WITH
SOME LEFTOVER FREEZING RAIN AS THE WARM NOSE WEAKENS THIS
AFTERNOON AND COLD AIR ADVECTION TAKES OVER.
00Z RUNS OF NAM AND ECMWF DEPICT BETTER QPF TO OBSERVED RADAR TRENDS
THAN THE CMC AND GFS. 00Z ECMWF SHOWING QPF THAT WOULD AGREE WITH
THE REFLECTIVITY FORECAST OF THE 04Z HRRR SO WILL BE RELYING MORE
UPON THE ECMWF FOR POP TRENDS.
MUCH OF THE SNOW AND ICE WILL BE ONGOING UNTIL AROUND 18Z FROM A
GENERAL MODEL CONSENSUS AND MODEL BUFKIT SOUNDING BOUNDARY LAYER
ANALYSIS. THE SIGNATURES WITHIN MSLP SHOW PROMINENT COLD AIR
DAMMING. THE NE WINDS AT THE SURFACE WILL BE INCREASING WITH A
PERSISTENT WARM NOSE AROUND 900MB...HELPING SET UP FOR PROLONGED
FREEZING RAIN ACROSS NYC/COASTAL AREAS OF NE NJ AND SOUTHERN PARTS
OF THE LOWER HUDSON VALLEY AS WELL AS LONG ISLAND. FARTHER NORTH THE
WARM NOSE WILL MAKE ITS APPEARANCE BRIEFLY BUT SNOW WILL BE DOMINANT
BEFORE AND AFTER THAT TIME.
WHAT MAKES THIS A CHALLENGING FORECAST IS HOW WELL THE MODELS ARE
DEPICTING THE WARM NOSE AND ITS DEPTH RELATIVE TO COLDER AIR NEAR
THE SURFACE. SLEET COULD VERY WELL BE MORE OF A POSSIBILITY WITH
LESS OF A WARM NOSE BUT A THICKER NEAR SURFACE LAYER BELOW FREEZING.
QPF IS ALWAYS AN AREA OF LARGER UNCERTAINTY WITHIN THE FORECAST
MODELS AND WHILE IT COULD TREND HIGHER IF GFS IS CORRECT...NAM AND
ECMWF AS AFOREMENTIONED ARE BETTER MATCHING UP WITH OBSERVATIONS IN
RADAR SO THIS WOULD MAKE FOR LIGHTER QPF...A GENERAL 0.2 TO 0.5
LIQUID EQUIVALENT WITH AROUND 0.2 FOR NYC/URBAN NE NJ/LONG ISLAND
AND GRADUALLY HIGHER TOTALS TO THE NORTH.
FOR HIGH TEMPS TODAY...ECMWF AND NAM12 RAW 2M TEMPS WERE USED MID
20S TO AROUND 30 FOR MUCH OF THE REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
THE SECOND HALF OF THIS WINTER EVENT WILL BE ONGOING WITH THE LOW
PRESSURE IN THE ATLANTIC SLIGHTLY DEEPENING AHEAD OF THE MID AND
UPPER LEVEL TROUGH AS HIGH PRESSURE WEAKENS IN SOUTHEAST CANADA.
THE WEAKENING PRESSURE GRADIENT WILL LEAD TO WINDS DECREASING.
THERE WILL BE MAINLY SNOW LEFTOVER GOING THROUGH THE EVENING WITH
PERHAPS ANOTHER 1-2 INCHES. WITH THE COLD AIR ADVECTION CONTINUING
WITHIN THE ATMOSPHERE AND RETENTION OF ENOUGH MOISTURE AND HENCE
ICE NUCLEI...NO FURTHER ICE ACCRETION IS EXPECTED. LOWS WERE A
BLEND OF NAM12 2M TEMPS AND GMOS.
FOR TUESDAY...ANOTHER STRONG CANADIAN HIGH BUILDS IN FROM THE
NORTHWEST. THIS WILL REINFORCE THE COLD AIR ADVECTION BUT WITH MORE
SUN...TEMPERATURES WILL BE RELATIVELY WARMER THAN THE PREVIOUS DAY.
HIGHS FORECAST ARE IN THE LOWER 30S FOR MOST LOCATIONS. THESE WERE
TAKEN FROM 2/3 GMOS AND 1/3 NAM12 2M TEMPERATURES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
AN ACTIVE UPPER NORTHERN STREAM WILL BRING A COUPLE OF SHORTWAVES
THROUGH THE REGION WEDNESDAY NIGHT NIGHT AND SATURDAY NIGHT. WHILE
AT THE SURFACE ONE LOW IS EXPECTED TO MOVE ACROSS THE AREA WEDNESDAY
NIGHT INTO THURSDAY...MOVING OFF THE DELMARVA THURSDAY NIGHT AND
INTENSIFY...AND MOVE TO THE NORTHEAST BY FRIDAY MORNING. COLD AIR
WILL BE IN PLACE AND AN ALL LIGHT SNOW EVENT IS FORECAST. AT THIS
TIME WITH THE STORM QUICK MOVING A COUPLE OF INCHES OF SNOW
ACCUMULATION IS POSSIBLE.
MUCH COLDER AIR MOVES INTO THE AREA BEHIND THE DEPARTING LOW
THURSDAY NIGHT INTO FRIDAY NIGHT AS HIGH PRESSURE BUILDS TO THE
WEST. THE HIGH QUICKLY WEAKENS AS ANOTHER SURFACE LOW MOVES OUT OF
CENTRAL CANADA AND TRACKS WEST AND SOUTH...MOVING OFF THE MID
ATLANTIC COAST SATURDAY NIGHT. THE AREA WILL BE ON THE EDGE OF THE
PRECIPITATION SHIELD WITH THIS LOW...WITH RATHER LIGHT
PRECIPITATION...AND WILL HAVE ONLY SLIGHT CHANCE POPS LATE SATURDAY
INTO SATURDAY NIGHT. WITH A COLD AIRMASS IN PLACE AS THE LOW TRACKS
THROUGH LIGHT SNOW IS EXPECTED. THE COLD AIR WILL BE RE ENFORCED
BEHIND THE LOW WITH TEMPERATURES POSSIBLY THE COLDEST OF THE WINTER
SEASON SUNDAY NIGHT...WITH LOWS BELOW ZERO ACROSS MUCH OF THE
INLAND...AND APPROACHING ZERO NEAR THE COAST.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
HIGH IMPACT WINTER WEATHER EVENT EXPECTED IN THE NY METRO TODAY
WAVES LOW PRESSURE WILL MOVE ALONG A COLD FRONT TO THE SOUTH.
MAINLY IFR. WINTRY MIX CHANGES TO SNOW THIS AFTN FOR MOST TERMINALS.
A LIGHT PCPN EVENT OVERALL...BUT POTENTIALLY HIGH IMPACT DUE TO THE
PROLONGED PERIOD OF LIGHT FROZEN/FREEZING PCPN.
NE WINDS NEAR 15 KT WITH GUSTS JUST OVER 20 KT.
FORECAST SNOW TOTALS...
KJFK/KLGA/KEWR/KTEB/ISP...1-2 INCHES...WITH UP TO AROUND A TENTH OF
AN INCH OF ICE.
KHPN/KBDR/KGON...2-3 INCHES...WITH UP TO AROUND A TENTH OF AN INCH
OF ICE.
KSWF...4-7 INCHES.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: BRIEF SHOWER OR TWO OF -FZRA POSSIBLE BEFORE
10Z. CHC TEMPO OR PREVAILING MVFR TODAY. CHANGE TO SNOW MAY BE OFF
BY AN HOUR OR TWO.
KLGA FCSTER COMMENTS: BRIEF SHOWER OR TWO OF -FZRA POSSIBLE BEFORE
10Z.CHC TEMPO OR PREVAILING MVFR TODAY. CHANGE TO SNOW MAY BE OFF BY
AN HOUR OR TWO.
KEWR FCSTER COMMENTS: BRIEF SHOWER OR TWO OF -FZRA POSSIBLE BEFORE
10Z. CHC TEMPO OR PREVAILING MVFR TODAY. CHANGE TO SNOW MAY BE OFF
BY AN HOUR OR TWO.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: BRIEF SHOWER OR TWO OF -FZRA POSSIBLE BEFORE
10Z. OCCASIONAL GUSTS UP TO 20 KT POSSIBLE THROUGH EARLY AFTN. CHC
TEMPO OR PREVAILING MVFR TODAY. CHANGE TO SNOW MAY BE OFF BY AN HOUR
OR TWO.
KHPN FCSTER COMMENTS: GUSTS THIS MORNING MIGHT BE ONLY OCCASIONAL.
CHC TEMPO OR PREVAILING MVFR TODAY. CHANGE TO SNOW MAY BE OFF BY AN
HOUR OR TWO.
KISP FCSTER COMMENTS: GUSTS BEFORE 12Z MIGHT BE ONLY OCCASIONAL.
CHANGE TO SNOW MAY BE OFF BY AN HOUR OR TWO.
&&
.MARINE...
INCREASING WINDS AND SEAS AS PRESSURE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE NORTH OF THE WATERS AND LOW PRESSURE SOUTH OF THE WATERS.
GALES FOR THE OCEAN TODAY AND TONIGHT...COULD DIMINISH EARLIER
TONIGHT THAN FORECAST. WIND GUSTS WERE PRETTY CLOSE TO THE
THRESHOLD SO LEFT THE END TIMING AS BEFORE AND UPGRADED TO GALE
WARNINGS FOR THE OCEAN. SEAS ON THE OCEAN INCREASE TO 6 TO 9 FT
LATER THIS AFTERNOON AND INTO THIS EVENING.
NON-OCEAN WATERS WILL HAVE SCA CONDITIONS THROUGH TONIGHT. THESE
COULD LINGER ON TUESDAY BUT A DOWNWARD TREND IS FORECAST AND
CONDITIONS SEEMED MARGINAL SO SCA WAS NOT YET EXTENDED THROUGH
TUESDAY.
SMALL CRAFT WIND GUSTS AND SEAS REMAIN TUESDAY NIGHT INTO
WEDNESDAY ON THE OCEAN WATERS WHILE THE REMAINDER OF THE FORECAST
WATERS ARE BELOW ADVISORY LEVELS. LONG TERM SMALL CRAFT SEAS ON
THE OCEAN REMAIN INTO FRIDAY NIGHT. LOW PRESSURE DEEPENING EAST OF
THE WATERS THURSDAY NIGHT INTO FRIDAY WILL PRODUCE SMALL CRAFT
GUSTS ON THE OCEAN AND EASTERN FORECAST WATERS. WITH THE LOW
MOVING TO THE NORTHEAST FRIDAY NIGHT INTO SATURDAY WIND GUSTS WILL
DIMINISH TO BELOW SMALL CRAFT. SEAS ALSO DIMINISH BELOW SMALL
CRAFT ON THE OCEAN BY LATE FRIDAY NIGHT INTO EARLY SATURDAY...AND
REMAIN BELOW THROUGH SATURDAY.
&&
.HYDROLOGY...
LIQUID EQUIVALENT AMOUNTS OF AROUND 0.1 TO 0.5 INCH ARE EXPECTED
WITH THIS SYSTEM THROUGH TONIGHT. NO HYDROLOGIC PROBLEMS ARE
EXPECTED.
A TENTH OR TWO OF LIQUID EQUIVALENT IS POSSIBLE FROM WEDNESDAY
NIGHT THROUGH THURSDAY NIGHT...FALLING AS LIGHT SNOW.
&&
.EQUIPMENT...
NEW YORK CITY ALL HAZARDS RADIO...FREQUENCY 162.550 MHZ...IS OFF
THE AIR DUE TO A TELEPHONE LINE COMMUNICATIONS FAILURE.
TECHNICIANS ARE WORKING ON THE ISSUE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 6 AM EST TUESDAY FOR CTZ005>012.
NY...WINTER WEATHER ADVISORY UNTIL 6 AM EST TUESDAY FOR NYZ067>075-
078>081-176>179.
NJ...WINTER WEATHER ADVISORY UNTIL 6 AM EST TUESDAY FOR NJZ002-004-
006-103>108.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR ANZ330-335-338-
340-345.
GALE WARNING UNTIL 6 AM EST TUESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...JM/MET
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...MET
AVIATION...JC
MARINE...JM/MET
HYDROLOGY...JM/MET
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1013 PM EST TUE FEB 10 2015
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION TONIGHT THROUGH
WEDNESDAY...BEFORE A DRY COLD FRONT SWEEPS THROUGH THE AREA ON
THURSDAY. DRY HIGH PRESSURE WILL PREVAIL INTO SATURDAY...WITH A
REINFORCING COLD FRONT MOVING THROUGH SATURDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
NO MAJOR CHANGES TO THE PREVIOUS FORECAST OTHER THAN TO TAKE DOWN
THE LAKE WIND ADVISORY. LATEST SATELLITE IMAGERY INDICATES MAINLY
CLEAR SKIES OVER SOUTHEAST SC/GA WITH UPSTREAM CLOUDS OVER SE
NC/NE SC ON A DIMINISHING TREND. A DIMINISHING PRESSURE GRADIENT
WILL MEAN DIMINISHING WINDS THE REST OF THE NIGHT...WITH THE
STRONGEST WINDS OVER COASTAL SC. TEMPERATURES WILL FALL BACK INTO
THE MID TO UPPER 30S MOST AREAS BY DAYBREAK...COOLEST ACROSS
INTERIOR SE SC.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
SURFACE HIGH PRESSURE WILL BRIEFLY BUILD IN WEDNESDAY AHEAD OF AN
APPROACHING COLD FRONT MOVING THROUGH THE OHIO VALLEY...WHILE WEAK
RIDGING PREVAILS ALOFT. DESPITE MOSTLY CLEAR SKIES...NORTHERLY FLOW
WILL KEEP TEMPERATURES SLIGHTLY COOLER THAN NORMAL MAINLY IN THE
UPPER 50S/LOW 60S. LOWS WEDNESDAY NIGHT WILL BE IN THE UPPER
30S/AROUND 40.
THURSDAY...DEEP UPPER TROUGH AND ASSOCIATED VORT MAX WILL SWING EAST
AND SEND A COLD FRONT THROUGH THE AREA. LACK OF SIGNIFICANT MOISTURE
AND SUBSIDENCE NOTED IN MODEL SOUNDINGS WILL KEEP A DRY FORECAST IN
TACT. BREEZY CONDITIONS WILL DEVELOP THROUGH THE DAY AS THE PRESSURE
GRADIENT TIGHTENS AND STRONGER WINDS ALOFT GET MIXED DOWN TO THE
SURFACE. WEST/NORTHWEST WINDS OF 15-20 MPH WITH HIGHER GUSTS WILL BE
COMMON ACROSS THE AREA. WESTERLY DOWNSLOPE FLOW WILL HELP BOOST
TEMPERATURES TO THE LOW 60S. STRONG COLD ADVECTION IN WAKE OF THE
FRONT WILL ALLOW TEMPS TO DROP WELL BELOW NORMAL THURSDAY
NIGHT...WITH LOWS IN THE UPPER 20S. ELEVATED WINDS WILL MAKE IT FEEL
COLDER...HOWEVER CONDITIONS LOOK TO REMAIN ABOVE WIND CHILL ADVISORY
CRITERIA.
FRIDAY...WEAKENING HIGH PRESSURE WILL MOVE INTO THE AREA ALLOWING
QUIET WEATHER TO CONTINUE. RATHER COLD AIR MASS WILL REMAIN IN PLACE
WITH SHALLOW LOW LEVEL THICKNESS VALUES SUPPORTING HIGHS ONLY IN THE
MID 40S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A COLD AND DRY SPELL IS SETTING UP FOR THE LONG RANGE PERIODS.
CANADIAN HIGH PRESSURE WILL WEAKEN ON SATURDAY WITH SOME WEAK ZONAL
FLOW ALLOWING FOR A SLIGHT TEMPERATURE RECOVERY INTO THE 50S.
HOWEVER A REINFORCING COLD FRONT ASSOCIATED WITH A POWERFUL UPPER
SHORTWAVE WILL PUSH THROUGH SATURDAY NIGHT. OVERNIGHT LOWS BOTH
SATURDAY AND SUNDAY NIGHTS WILL DROP WELL INTO THE 20S. SUNDAY HIGHS
WILL STRUGGLE TO REACH 40 DEGREES AND BE COMBINED WITH 10-20 MPH
WINDS...POTENTIALLY RESULTING IN WIND CHILL ADVISORY CONDITIONS.
SOME RECOVERY IN TEMPS AND DEWPOINTS EXPECTED MONDAY INTO TUESDAY AS
THE AREA OF HIGH PRESSURE MOVES OFF THE SOUTHEAST COAST AND RETURN
FLOW DEVELOPS. A COLD FRONT COULD AFFECT THE AREA LATE TUESDAY.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
VFR. GUSTS NEAR 20 KT WILL LINGER AT KCHS THROUGH ABOUT 06Z. 2K
FT WINDS WILL BE NORTHERLY AT 35-40 KT AT KCHS AS WELL THROUGH
THIS TIME BUT WITH GUSTY SURFACE WINDS WE DO NOT ANTICIPATE LLWS
TO BE A CONCERN.
EXTENDED AVIATION OUTLOOK...VFR.
&&
.MARINE...
TONIGHT...EXTENDED THE ONGOING GALE WARNINGS A BIT LONGER AS THE
LATEST RAP GUIDANCE SHOWS A BIT OF A SURGE PRIOR TO
DAYBREAK...ALTHOUGH GALES WILL BE MARGINAL AND MAINLY CONFINED TO
THE EASTERN PORTIONS OF THE CHARLESTON COUNTY WATERS AND OUTER GA
WATERS. ALSO EXTENDED THE ADVISORY FOR CHARLESTON HARBOR SEVERAL
MORE HOURS FOR 25 KT GUSTS...MAINLY NEAR THE HARBOR ENTRANCE.
ELSEWHERE THE ADVISORIES WILL HANG ON THROUGH THE NIGHT...MAINLY
FOR GUSTS TO 25 KT.
WEDNESDAY THROUGH SUNDAY...WINDS/SEAS WILL SUBSIDE ON WEDNESDAY
WITH ALL NEAR SHORE MARINE ZONES HEADLINE-FREE BY MIDDAY. OUTER GA
WATERS WILL LIKELY HANG ON TO THE SMALL CRAFT ADVISORY THROUGH THE
DAY AS SEAS ARE STILL EXPECTED TO REMAIN 4-6 FEET. CONDITIONS WILL
ONCE AGAIN DETERIORATE THURSDAY WITH THE NEXT COLD FRONT THAT
MOVES THROUGH THE WATERS. STRONG COLD ADVECTION IN WAKE OF THE
FRONT WILL RESULT IN SOLID SMALL CRAFT ADVISORIES FOR MOST IF NOT
ALL OF THE WATERS THURSDAY AFTERNOON INTO FRIDAY. WINDS/SEAS WILL
DROP BELOW ADVISORY CRITERIA ON FRIDAY. YET ANOTHER ROUND OF
HAZARDOUS MARINE CONDITIONS EXPECTED SATURDAY NIGHT INTO SUNDAY
BEHIND A COLD FRONT. WINDS MAY EVEN REACH GALE FORCE THUS HAVE
MAINTAINED MENTION IN THE HAZARDOUS WEATHER OUTLOOK.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EST WEDNESDAY FOR AMZ330.
SMALL CRAFT ADVISORY UNTIL 9 AM EST WEDNESDAY FOR AMZ352-354.
GALE WARNING UNTIL 2 AM EST WEDNESDAY FOR AMZ350-374.
&&
$$
SYNOPSIS...WMS
NEAR TERM...RJB
SHORT TERM...ECT
LONG TERM...JRL
AVIATION...ECT/RJB
MARINE...ECT/JRL/RJB
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
201 AM EST MON FEB 9 2015
.SYNOPSIS...
A COLD FRONT WILL PUSH THROUGH LATER TODAY...PROVIDING SHOWERS AND
POSSIBLY AN ISOLATED THUNDERSTORM. FAIR WEATHER EXPECTED TUESDAY
AND WEDNESDAY WITH GENERALLY SEASONAL TEMPERATURES. A DRY COLD
FRONT WILL MOVE THROUGH THURSDAY...FOLLOWED BY MUCH COLDER
CONDITIONS FRIDAY THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
EARLY THIS MORNING...COLD FRONT WILL REMAIN WEST OF THE FORECAST AREA
DURING THE EARLY MORNING HOURS. SOUTHWESTERLY WINDS WILL REMAIN
GENERALLY AROUND 5 MPH THROUGH THE NIGHT. LATEST HRRR AS WELL AS
00Z NAM AND GFS SUGGEST THAT THE EARLY MORNING HOURS WILL REMAIN
DRY. ALTHOUGH MOISTURE WILL INCREASE BEFORE DAWN...THE SURFACE
WINDS ALONG WITH A LOW-LEVEL JET SHOULD HELP TO INHIBIT ANY
WIDESPREAD FOG. CAN NOT RULE OUT SOME PATCHY FOG THOUGH IN
ISOLATED LOCATIONS. LOWS AROUND SUNRISE RATHER MODERATE...WITH
READINGS AROUND 50 DEGREES.
LATER TODAY...LOW PRESSURE WILL BEGIN THE DAY OVER THE MID-
ATLANTIC WITH A COLD FRONT EXTENDING THROUGH THE TN RIVER VALLEY. THROUGH
THE DAY THE LOW CENTER WILL MOVE SOUTHEASTWARD INTO THE CAROLINAS BY
MID EVENING THEN OFFSHORE TONIGHT. THIS WILL BRING THE COLD FRONT
THROUGH THE FORECAST AREA DURING THE AFTERNOON HOURS WITH COOLER
AND DRIER AIR MOVING IN TONIGHT. HRRR/NAM/GFS ALL SHOWING BEST
CHANCE FOR RAIN ACROSS THE AREA WILL BE MAINLY DURING THE
AFTERNOON AND EVENING HOURS. INSTABILITY REMAINS WEAK WITH
FROPA...HOWEVER THERE IS ENOUGH INSTABILITY AND FRONTAL LIFT TO
REMAIN WITH ISOLATED THUNDER DURING THE AFTERNOON AND EARLY EVENING
HOURS. HIGH TEMPERATURES TODAY WILL BE IN THE MIDDLE TO UPPER 60S.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
THE RAIN WILL END LATER THIS EVENING AS THE COLD FRONT MOVES
TOWARDS THE COAST. SKIES WILL REMAIN MOSTLY CLOUDY TONIGHT AS SOME
PVA LINGERS BEHIND THE FRONT. LOWS TONIGHT WILL BE MAINLY IN THE
LOWER TO MIDDLE 40S.
TUESDAY AND TUESDAY NIGHT...LOW PRESSURE WILL TRACK FURTHER AWAY
FROM THE REGION TUESDAY AS HIGH PRESSURE AND WEAK UPPER LEVEL
RIDGING BUILD ACROSS THE AREA. THIS WILL BRING SLIGHTLY COOLER AND
DRIER AIR BACK TO THE REGION ALONG WITH MOSTLY CLEAR SKIES. WITH A
MODERATE PRESSURE GRADIENT OVER THE REGION DURING THE DAY TUESDAY
WINDS WILL BE NORTHERLY AROUND 10 MPH WITH GUSTS AROUND 15
MPH...WHICH WILL DISSIPATE DURING THE EVENING AS THE GRADIENT
WEAKENS. TEMPERATURES WILL RANGE FROM THE MID 50S IN THE NORTHERN
MIDLANDS TO AROUND 60 IN THE CSRA WITH OVERNIGHT LOWS IN THE LOWER
TO MIDDLE 30S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
MODELS REMAIN IN GOOD AGREEMENT THROUGH THE LONG TERM WITH A QUICK
SUCCESSION OF SYSTEMS CROSSING THE REGION. HIGH PRESSURE WILL
REMAIN IN CONTROL OF THE REGION WEDNESDAY AS LOW PRESSURE TRACKS
THROUGH THE GREAT LAKES AND PUSHES A COLD FRONT INTO THE OHIO
VALLEY WEDNESDAY EVENING. THE COLD FRONT WILL CROSS THE MIDLANDS
DURING THE LATE MORNING/EARLY AFTERNOON HOURS THURSDAY AND MOVE
OFFSHORE THURSDAY EVENING. BEHIND THE FRONT COLDER AND DRIER AIR
WILL QUICKLY OVERTAKE THE REGION ALONG WITH A TIGHT PRESSURE
GRADIENT. HAVE INCREASED WIND SPEEDS FOR THURSDAY AND THURSDAY
NIGHT...HOWEVER MODELS INDICATE WIND SPEEDS COULD APPROACH 20 MPH
WITH HIGHER GUSTS THURSDAY AFTERNOON AND EVENING AS THE COLD AIR
ADVECTION MOVES INTO THE AREA. THE COLDER AIR AND HIGH PRESSURE
WILL REMAIN IN CONTROL OF THE AREA FOR FRIDAY THROUGH SUNDAY WITH
AN UPPER LEVEL DISTURBANCE MOVING ACROSS THE AREA SATURDAY AND
SUNDAY. LATEST MODEL GUIDANCE INDICATING SOME ARCTIC AIR WILL KEEP
TEMPS WELL BELOW NORMAL THIS WEEKEND. HAVE TRENDED TEMPS DOWNWARD
FOR THE WEEKEND. DRY WEATHER EXPECTED THROUGH THE EXTENDED PERIOD.
TEMPERATURES THROUGH THE LONG TERM WILL BE SLIGHTLY ABOVE NORMAL
WEDNESDAY AND THURSDAY AND WELL BELOW NORMAL FOR FRIDAY THROUGH
SUNDAY.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH 15Z THEN MORE
UNCERTAINTY DURING THE AFTERNOON AND EVENING AS A COLD FRONT
PUSHES THROUGH THE REGION.
SURFACE LOW PRESSURE DEVELOPING OVER THE EASTERN OHIO VALLEY WILL
DRIFT SOUTHEASTWARD AS AN UPPER TROUGH AMPLIFIES TO THE
WEST...ALLOWING LOW LEVEL FLOW TO VEER MORE SOUTHWESTERLY AS
MOISTURE INCREASES ACROSS THE REGION. SATELLITE IMAGERY AND
OBSERVATIONS CONFIRM THIS AS WIDESPREAD LOW VFR CIGS AROUND
5000-6000 FT OVERSPREAD THE TERMINALS AT THE START OF THE FORECAST
PERIOD. A COLD FRONT WILL PUSH TOWARDS THE REGION THIS AFTERNOON
AND GUIDANCE SUGGESTS CIG RESTRICTIONS WILL OCCUR ALONG AND BEHIND
THE FRONT AFTER 21Z-00Z BUT CONFIDENCE IS LOW GIVEN HRRR/RAP
SHOWING ONLY LOW END VFR CIGS CONTINUING. HAVE DECIDED TO
INTRODUCE MVFR CIGS 18Z-21Z WITH SHOWERS AHEAD OF THE FRONT. THERE
ARE INDICATIONS OF IFR CIGS AFTER 00Z BUT WILL NOT INCLUDE IN THIS
FORECAST. WEAK INSTABILITY AND STRONG FORCING MAY LEAD TO ISOLATED
THUNDERSTORMS AHEAD OF THE FRONT BUT DUE TO THE ISOLATED NATURE
WILL NOT INCLUDE IN THE FORECAST.
EXTENDED AVIATION OUTLOOK...A FRONT MAY PROVIDE A CHANCE OF
SHOWERS EARLY MONDAY EVENING. RESTRICTIONS POSSIBLE MONDAY NIGHT
UNTIL DRIER AIR WORKS INTO THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1258 AM EST MON FEB 9 2015
.SYNOPSIS...
A COLD FRONT WILL COME THROUGH MONDAY...PROVIDING SHOWERS AND
POSSIBLY AN ISOLATED THUNDERSTORM. FAIR WEATHER EXPECTED TUESDAY
AND WEDNESDAY WITH GENERALLY SEASONAL TEMPERATURES. A DRY COLD
FRONT WILL MOVE THROUGH THURSDAY...FOLLOWED BY MUCH COOLER
CONDITIONS FRIDAY INTO SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
COLD FRONT WILL REMAIN WEST OF THE FORECAST AREA OVERNIGHT.
SOUTHWESTERLY WINDS WILL REMAIN GENERALLY AROUND 5 MPH THROUGH THE
NIGHT. THE OVERNIGHT HOURS WILL REMAIN DRY...WITH ONLY A VERY
SLIGHT CHANCE OF LIGHT PRECIP GETTING CLOSE TO THE WESTERN CWA
TOWARDS MORNING. THIS IS CONSISTENT WITH HRRR MODEL SIMULATED
REFLECTIVITY. ALTHOUGH MOISTURE WILL INCREASE OVERNIGHT...THE
SURFACE WINDS ALONG WITH A LOW-LEVEL JET SHOULD HELP TO INHIBIT
ANY WIDESPREAD FOG. CAN NOT RULE OUT SOME PATCHY FOG THOUGH IN
ISOLATED LOCATIONS. OVERNIGHT LOWS RATHER MODERATE...WITH READINGS
AROUND 50 DEGREES.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
MONDAY AND MONDAY NIGHT...LOW PRESSURE WILL BEGIN THE DAY OVER
NORTHEASTERN WV WITH A COLD FRONT EXTENDING THROUGH THE CENTRAL
GULF STATES. THROUGH THE DAY THE LOW CENTER WILL MOVE
SOUTHEASTWARD REACHING NORTHERN NC BY MID EVENING THEN OFFSHORE
MONDAY NIGHT. THIS WILL BRING THE COLD FRONT THROUGH THE FORECAST
AREA DURING THE AFTERNOON HOURS WITH COOLER AND DRIER AIR MOVING
IN MONDAY NIGHT. MODELS CONTINUE TO INCREASE THE CHANCE OF RAIN
AND WITH THE UPPER LEVEL TROUGH CONTINUING TO AMPLIFY AND
SOUTHWESTERLY FLOW THROUGH THE DAY MONDAY USHERING GULF MOISTURE
INTO THE AREA HAVE SLIGHTLY INCREASED POPS FOR MONDAY AFTERNOON
INTO MONDAY EVENING. INSTABILITY REMAINS WEAK WITH FROPA...HOWEVER
THERE IS ENOUGH INSTABILITY AND FRONTAL LIFT TO REMAIN WITH
ISOLATED THUNDER DURING THE AFTERNOON AND EVENING HOURS. HIGH
TEMPERATURES MONDAY WILL BE IN THE MIDDLE TO UPPER 60S WITH LOWS
MONDAY NIGHT IN THE LOWER TO MIDDLE 40S.
TUESDAY AND TUESDAY NIGHT...LOW PRESSURE WILL TRACK FURTHER AWAY
FROM THE REGION TUESDAY AS HIGH PRESSURE AND WEAK UPPER LEVEL
RIDGING BUILD ACROSS THE AREA. THIS WILL BRING SLIGHTLY COOLER AND
DRIER AIR BACK TO THE REGION ALONG WITH MOSTLY CLEAR SKIES. WITH A
MODERATE PRESSURE GRADIENT OVER THE REGION DURING THE DAY TUESDAY
WINDS WILL BE NORTHERLY AROUND 10 MPH WITH GUSTS AROUND 15
MPH...WHICH WILL DISSIPATE DURING THE EVENING AS THE GRADIENT
WEAKENS. TEMPERATURES WILL RANGE FROM THE MID 50S IN THE NORTHERN
MIDLANDS TO AROUND 60 IN THE CSRA WITH OVERNIGHT LOWS IN THE LOWER
TO MIDDLE 30S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
MODELS REMAIN IN GOOD AGREEMENT THROUGH THE LONG TERM WITH A QUICK
SUCCESSION OF SYSTEMS CROSSING THE REGION. HIGH PRESSURE WILL
REMAIN IN CONTROL OF THE REGION WEDNESDAY AS LOW PRESSURE TRACKS
THROUGH THE GREAT LAKES AND PUSHES A COLD FRONT INTO THE OHIO
VALLEY WEDNESDAY EVENING. THE COLD FRONT WILL CROSS THE MIDLANDS
DURING THE LATE MORNING/EARLY AFTERNOON HOURS THURSDAY AND MOVE
OFFSHORE THURSDAY EVENING. BEHIND THE FRONT COLDER AND DRIER AIR
WILL QUICKLY OVERTAKE THE REGION ALONG WITH A TIGHT PRESSURE
GRADIENT. HAVE INCREASED WIND SPEEDS FOR THURSDAY AND THURSDAY
NIGHT...HOWEVER MODELS INDICATE WIND SPEEDS COULD APPROACH 20 MPH
WITH HIGHER GUSTS THURSDAY AFTERNOON AND EVENING AS THE COLD AIR
ADVECTION MOVES INTO THE AREA. THE COLDER AIR AND HIGH PRESSURE
WILL REMAIN IN CONTROL OF THE AREA FOR FRIDAY THROUGH SUNDAY WITH
AN UPPER LEVEL DISTURBANCE MOVING NORTH OF THE AREA SATURDAY AND
SUNDAY. THIS WILL BRING SOME CLOUDINESS BACK TO THE FORECAST WITH
NO RAIN EXPECTED. TEMPERATURES THROUGH THE LONG TERM WILL BE
SLIGHTLY ABOVE NORMAL WEDNESDAY AND THURSDAY WITH BELOW NORMAL FOR
FRIDAY THROUGH SUNDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH 15Z THEN MORE
UNCERTAINTY DURING THE AFTERNOON AND EVENING AS A COLD FRONT
PUSHES THROUGH THE REGION.
SURFACE LOW PRESSURE DEVELOPING OVER THE EASTERN OHIO VALLEY WILL
DRIFT SOUTHEASTWARD AS AN UPPER TROUGH AMPLIFIES TO THE
WEST...ALLOWING LOW LEVEL FLOW TO VEER MORE SOUTHWESTERLY AS
MOISTURE INCREASES ACROSS THE REGION. SATELLITE IMAGERY AND
OBSERVATIONS CONFIRM THIS AS WIDESPREAD LOW VFR CIGS AROUND
5000-6000 FT OVERSPREAD THE TERMINALS AT THE START OF THE FORECAST
PERIOD. A COLD FRONT WILL PUSH TOWARDS THE REGION THIS AFTERNOON
AND GUIDANCE SUGGESTS CIG RESTRICTIONS WILL OCCUR ALONG AND BEHIND
THE FRONT AFTER 21Z-00Z BUT CONFIDENCE IS LOW GIVEN HRRR/RAP
SHOWING ONLY LOW END VFR CIGS CONTINUING. HAVE DECIDED TO
INTRODUCE MVFR CIGS 18Z-21Z WITH SHOWERS AHEAD OF THE FRONT. THERE
ARE INDICATIONS OF IFR CIGS AFTER 00Z BUT WILL NOT INCLUDE IN THIS
FORECAST. WEAK INSTABILITY AND STRONG FORCING MAY LEAD TO ISOLATED
THUNDERSTORMS AHEAD OF THE FRONT BUT DUE TO THE ISOLATED NATURE
WILL NOT INCLUDE IN THE FORECAST.
EXTENDED AVIATION OUTLOOK...A FRONT MAY PROVIDE A CHANCE OF
SHOWERS EARLY MONDAY EVENING. RESTRICTIONS POSSIBLE MONDAY NIGHT
UNTIL DRIER AIR WORKS INTO THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
841 PM CST TUE FEB 10 2015
.UPDATE...
840 PM CST
FOR EVENING UPDATE...
MADE SOME CHANGES TO AERIAL COVERAGE IN POPS/WX FOR TONIGHT...WITH
FOCUS INITIALLY ALONG RELATIVELY NARROW BAND SEEN IN RADAR RETURNS
FROM PEORIA NORTHEAST TO NEAR JOLIET AT 815 PM.
00Z SOUNDING FROM DVN SHOWS IMPRESSIVE WARM LAYER OF +6 C AT ABOUT
870 MB...WITH STEEP LAPSE RATES FROM THERE TO NEAR 700 MB...AND
ANOTHER LAYER OF STEEP LAPSE RATES ABOVE ABOUT 640 MB. GIVEN THESE
STEEP LAPSE RATES ALOFT IT/S NOT SURPRISING TO SEE A CONVECTIVE
NATURE TO RADAR RETURNS ACROSS THE AREA THIS EVENING...WITH 35-40
DBZ RETURNS NOTED IN "CORES" SOUTHWEST OF KLOT. THIS APPEARS TO BE
IN LINE WITH LOW LEVEL THERMAL ADVECTION AXIS PER 00Z RAOB ANALYSIS
AND SPC MESOANALYSIS DATA. GIVEN THERMAL PROFILES WOULD EXPECT
RAIN/FREEZING RAIN TO BE A PRIMARY PRECIP TYPE...THOUGH THE
CONDITIONALLY UNSTABLE LAYER ALOFT APPEARS TO BE PRODUCE MAINLY
GRAUPEL/ICE PELLETS WHERE THE STRONGER RADAR RETURNS ARE.
THANKFULLY...THE MUCH WEAKER RETURNS ELSEWHERE AND DRY LOW LEVELS
WERE RESULTING IN LITTLE/NO PRECIPITATION REACHING THE GROUND PER
SURFACE OBS AND PING PROJECT DATA.
PARENT SHORT WAVE CIRCULATION CLEARLY SEEN IN REGIONAL RADAR MOSAIC
LIFTING EAST-NORTHEAST ACROSS WI...AND EXPECT MOST OF THE CURRENT
LIGHT BANDED PRECIP WILL MOVE EAST OF THE AREA BY/SHORTLY AFTER
MIDNIGHT. SECONDARY SHORT WAVE CURRENTLY HEADING INTO SOUTHWEST
MINNESOTA WILL DIG TOWARD THE AREA OVERNIGHT HOWEVER...WITH SURFACE
LOW PRESSURE CURRENTLY OVER MINNESOTA MOVING EAST AND THE TRAILING
SURFACE TROUGH/OCCLUDED FRONT MOVING INTO THE CWA LATE
TONIGHT/WEDNESDAY MORNING. AMPLE LOW-LEVEL MOISTURE EXISTS WITHIN
THE LOW LEVEL FRONTAL ZONE...NOTED IN EXTENSIVE AREA OF LOW CLOUDS
ACROSS IA/MN/WI. FORECAST SOUNDINGS SUGGEST POTENTIAL FOR AT LEAST
SOME PATCHY LIGHT FREEZING DRIZZLE OVERNIGHT INTO EARLY WEDNESDAY AS
SHORT WAVE PRODUCES LARGE SCALE ASCENT ATOP SHALLOW MOIST NEAR
SURFACE LAYER...WHICH FORECAST SOUNDINGS INDICATE WILL NOT BE COOL
ENOUGH FOR ICE NUCLEI. THEREFORE...LIGHT FREEZING DRIZZLE POTENTIAL
INCREASES AFTER MIDNIGHT INTO EARLY WEDNESDAY MORNING...BEFORE
FRONTAL PASSAGE AND GUSTY NORTHWEST WINDS DRY THINGS OUT.
RATZER
&&
.SHORT TERM...
345 PM CST
THROUGH THURSDAY...
MAIN FORECAST CONCERNS ARE WITH PRECIP/PRECIP TYPE LATE THIS
AFTERNOON INTO THE OVERNIGHT...LINGERING LIGHT SNOW SHOWERS ON
THURSDAY...AND THEN WITH ACCUMULATING LAKE EFFECT SNOW EXPECTED
LATE WEDNESDAY NIGHT INTO THURSDAY.
LATEST RADAR MOSAIC SHOWING LEADING EDGE OF PRECIP STILL STEADILY
PROGRESSING EAST ACROSS EASTERN IOWA...AND CURRENTLY APPROACHING
FAR NORTHWEST ILLINOIS AT THIS TIME. THIS PRECIP IS RIDING ALONG
WARM ADVECTION WING...OUT AHEAD OF THE SOUTHERN END OF A FAIRLY
STOUT VORT MAX MOVING THROUGH MINNESOTA AND WISCONSIN. WITH THIS
VORT MAX SHIFTING EAST THIS AFTERNOON INTO THE EVENING...LARGE
SCALE ASCENT WILL CONTINUE TO QUICKLY INCREASE ACROSS THE CWA.
PREVIOUSLY MENTIONED DRY AIR IN PLACE IS NOW APPEARING TO BE TOO
MUCH A FACTOR AS FORCING SHOULD BE ABLE TO OVERCOME IT. THIS WILL
LIKELY OCCUR AS SOON AS 23-00Z FOR THE NORTHWEST CWA AND THEN MORE
TOWARDS THE 2-3Z TIME FRAME FOR NORTH CENTRAL AND NORTHEAST
ILLINOIS. DID BRING POPS FURTHER SOUTH TOWARDS THE I80 CORRIDOR
BRIEFLY THIS EVENING...BUT STILL THINK THE BEST CHANCES FOR PRECIP
WILL BE ALONG AND NORTH OF THE I88 CORRIDOR. RAISED POPS TO HIGH
CHANCE POPS...AND LIMITED THEM HERE DUE TO OVERALL DURATION AND
COVERAGE WHICH APPEAR TO BE SMALL. UPON SATURATION...THERMAL
PROFILES WOULD SUGGEST A BRIEF MIX OF SNOW AND SLEET AT THE ONSET
BEFORE A QUICK TRANSITION OVER TO ALL SNOW OCCURS. EXPECT THIS
TREND TO CONTINUE THROUGH THE EVENING BUT WITH ONCE AGAIN SMALLER
WINDOW OF PRECIP EXPECTED...DONT ANTICIPATE MUCH IN TERMS OF ANY
ACCUMULATION. AT MOST WOULD A COUPLE OF TENTHS OF AN INCH OF
SNOWFALL. DEEPER MOISTURE IS LOST MORE TOWARDS 5Z ACROSS MUCH OF
THE CWA...BUT STILL HOVERING AROUND THE POSSIBILITY FOR INCLUSION
OF CRYSTALS. THIS WILL OCCUR THE DEPARTURE OF THE INITIAL
WAVE...BUT WITH THE ARRIVAL OF AN ADDITIONAL WAVE AND SURFACE
TROUGH/FRONT INTO EARLY WEDNESDAY MORNING. COVERAGE AND DURATION
OF ADDITIONAL PRECIP SHOULD ALSO BE SMALL...BUT WITH SNOW AND
FREEZING DRIZZLE THEN POSSIBLE. ANY LINGERING PRECIP SHOULD BE
DEPARTING WEDNESDAY MORNING...BUT WITH A SLIGHT POSSIBILITY FOR
FOR ADDITIONAL SCATTERED LIGHT SNOW SHOWERS POSSIBLE IN THE
AFTERNOON.
LARGE UPPER LEVEL TROUGH WILL BE DIGGING SOUTH ACROSS THE REGION
WEDNESDAY NIGHT...AS A STRONG VORT MAX ROUNDS THE BASE OF THIS
TROUGH. THIS WILL MARK THE ARRIVAL OF A MUCH COLDER AIRMASS AND
WITH THIS STRONG VORT MAX MOVING ACROSS THE AREA...SNOW SHOWERS
WILL LIKELY REDEVELOP WEDNESDAY NIGHT. OF MORE CONCERN IS WITH THE
LAKE EFFECT SNOW SHOWERS EXPECTED ACROSS NORTHWEST INDIANA...LATE
WEDNESDAY NIGHT INTO MUCH OF THURSDAY. AS THIS COLDER AIR SPILLS
SOUTH ACROSS THE LAKE WEDNESDAY NIGHT...THERMODYNAMICS OVER THE
LAKE BECOME HIGHLY CONDUCIVE FOR MODERATE TO HEAVY LAKE EFFECT
SNOW ACROSS THE SOUTHERN END OF THE LAKE. IMPRESSIVE INVERSION
HEIGHT AS WELL AS EVEN MORE IMPRESSIVE DELTA TS COINCIDING WITH
STRONG SYNOPTIC LIFT AND LIKELY STRONG CONVERGENCE WILL ALL BE
PRESENT...BUT WITH CONFIDENCE AS TO WHERE THE BEST SNOW WILL
DEVELOP IS STILL ON THE LOWER SIDE. AM CONFIDENT THAT PORTER
COUNTY WILL OBSERVE SNOW BUT AM NOT AS CONFIDENT WITH THE DURATION
OF THE LIKELY HEAVIER SNOW. CURRENT THINKING/FORECAST IS FOR LAKE
EFFECT TO DEVELOP LATE THURSDAY NIGHT INTO WEDNESDAY MORNING WITH
THE BEST ACCUMULATION DURING THIS TIME. BASED ON THIS...HAVE
ADVISORY LEVEL SNOWFALL TOTALS ACROSS PORTER COUNTY. IF LAKE
EFFECT SNOWBAND WERE TO SETUP ACROSS PORTER COUNTY WHICH IS STILL
A DEFINITE POSSIBILITY...THEN TOTALS COULD EASILY EXCEED 6 INCHES.
WILL NEED TO MONITOR THIS PERIOD FOR THE POTENTIAL OF HIGHER
SNOWFALL TOTALS AND WITH STRONG NORTHERLY WINDS ALSO
EXPECTED...THEN BLOWING AND DRIFTING SNOW COULD EASILY BECOME
ISSUES. AS HIGH PRESSURE BUILDS ACROSS THE REGION AND LOW LEVEL
FLOW BACKS...LAKE EFFECT SHOULD DIMINISH THURSDAY EVENING.
RODRIGUEZ
&&
.LONG TERM...
345 PM CST
THURSDAY NIGHT THROUGH TUESDAY...
HIGH PRESSURE IN PLACE AND THIS COLDER AIRMASS WILL LIKELY PRODUCE
LOW TEMPS IN THE SINGLE DIGITS AND WITH LOCATIONS ACROSS NORTH
CENTRAL ILLINOIS MORE THAN LIKELY FALLING BELOW ZERO. BRIEF LULL
IN THE SNOW WILL END ON FRIDAY AS ANOTHER WAVE PUSHES THROUGH THE
REGION...PRODUCING LIGHT ACCUMULATIONS OVER THE ENTIRE CWA.
ANOTHER PUSH OF COLDER AIR IS APPEARING LIKELY FOR THE WEEKEND AS
ANOTHER LARGE TROUGH DIGS ACROSS THE REGION. DID LOWER TEMPS BELOW
GUIDANCE AS A COLDER TREND IS MORE FAVORED. THIS WILL ALSO HELP
PRODUCE ANOTHER GOOD SETUP FOR LAKE EFFECT SNOW DEVELOPMENT ACROSS
NORTHWEST INDIANA ESPECIALLY SATURDAY AND SATURDAY NIGHT...WITH
SEVERAL INCHES OF SNOW A DISTINCT POSSIBILITY DURING THIS PERIOD.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* POTENTIAL FOR A VERY SHORT PERIOD OF SNOW...POSSIBLY BRIEFLY
MIXED WITH SLEET...THIS EVENING.
* CHANCE OF LIGHT FREEZING DRIZZLE LATE TONIGHT WITH LOWER MVFR
CIGS DEVELOPING.
* LOW MVFR CIGS LATE TONIGHT INTO WEDNESDAY MORNING.
* STRONG GUSTY WEST-NORTHWEST WINDS DEVELOPING BY LATE WEDNESDAY MORNING.
KJB
//DISCUSSION...UPDATED 00Z...
CURRENTLY WATCHING AN AREA OF PRECIPITATION DEVELOPING
ACROSS NORTHWESTERN ILLINOIS AND POINTS NORTHWARD INTO WISCONSIN.
THIS ACTIVITY COULD PRODUCE A SHORT PERIOD OF SNOW/GRAUPEL AT
KRFD OVER THE NEXT COUPLE HOURS...AND POSSIBLY AT SOME OF THE
EASTERN TERMINALS BETWEEN 02 AND 05 UTC THIS EVENING. THERE IS A
GOOD AMOUNT OF DRIER AIR IN THE LOWER LEVELS OF THE
ATMOSPHERE...SO MOST OF THE RADAR ECHOS ARE NOT REACHING THE
GROUND. HOWEVER...GIVEN THE POTENTIAL FOR SOME MORE ROBUST
CONVECTIVE CELLS...PERIODS OF SNOW AND OR GRAUPEL COULD BEGIN TO
REACH THE SURFACE AS IT BEGINS TO MOISTEN THE LOWER LEVELS. BRIEF
PERIODS OF IFR OR LOWER VISIBILITIES COULD RESULT IN THE HEAVIER
PRECIPITATION.
LOWER CLOUDS SHOULD BEGIN TO DEVELOP OVER THE AREA LATE TONIGHT INTO
WEDNESDAY MORNING. SOME AREAS OF -FZDZ COULD ALSO ACCOMPANY THESE
LOWER CIGS. HOWEVER...CONFIDENCE ON THE EXTENT OF -FZDZ LATER
TONIGHT REMAINS LOW.
A COLD FRONT WILL SHIFT ACROSS THE AREA BY LATE WEDNESDAY MORNING.
WINDS BEHIND THIS FRONT ARE EXPECTED TO RAPIDLY BECOME GUSTY OUT
OF THE WEST-NORTHWEST. CURRENT INDICATIONS ARE THAT WINDS WILL GUST
IN THE 25 TO 30 KT RANGE DURING THE AFTERNOON AND EVENING ON
WEDNESDAY. AN ARCTIC AIRMASS IS EXPECTED TO BEGIN SHIFTING SOUTHWARD
OVER THE AREA WEDNESDAY EVENING AS AN UPPER AIR DISTURBANCE
APPROACHES. THIS COULD RESULT IN SOME SNOW SHOWERS AND REDUCED
VISIBILITIES OVER THE AREA WEDNESDAY EVENING AND NIGHT.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM TO HIGH IN WIND TRENDS THROUGH THE PERIOD.
* LOW WITH THE PERIOD OF LIGHT SNOW/GRAUPEL THIS
EVENING.
* LOW TO MEDIUM CONFIDENCE IN FREEZING DRIZZLE LATE TONIGHT.
* MEDIUM TO HIGH CONFIDENCE IN LOW MVFR CIGS LATE TONIGHT INTO
WEDNESDAY MORNING.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
* THURSDAY...MVFR CIGS POSSIBLE EARLY. STRONG/GUSTY NORTHWEST WINDS.
* FRIDAY...SLIGHT CHANCE OF SNOW. MVFR POSSIBLE. WEST/SOUTHWEST
WINDS.
* SATURDAY...CHANCE OF FLURRIES. MVFR POSSIBLE. VERY STRONG/GUSTY
NORTHWEST WINDS.
* SUNDAY...DRY/VFR. WEST/SOUTHWEST WINDS.
* MONDAY...MVFR POSSIBLE. SOUTHWEST WINDS.
KJB
&&
.MARINE...
322 PM CST
MULTIPLE MARINE CONCERNS AS WE ENTER A VERY COLD AND ACTIVE PATTERN.
THIS EVENING...THERE COULD BE BRIEF WINDOW OF NEAR SMALL CRAFT
CONDITIONS ALONG THE FAR NORTHEAST ILLINOIS SHORE AS SOUTHEAST
WINDS INCREASE TO 15 TO 25 KT. WINDS WILL THEN SHIFT SOUTHERLY ON
THE ENTIRE LAKE AS A WEAK LOW OVER THE UPPER MIDWEST APPROACHES.
THERE COULD BE A FEW GUSTS TO 30 KT ON THE NORTHERN HALF OF THE
LAKE TONIGHT IN THE PEAK OF THE SOUTHERLY FLOW.
A STRONG COLD FRONT TRAILING FROM THE LOW WILL SWEEP ACROSS THE LAKE
BY MID DAY WEDNESDAY OR SO...WITH AN EXPANSIVE 1040+ MB ARCTIC HIGH
SPREADING IN FROM THE NORTHERN PLAINS BEHIND IT. VERY TIGHT PRESSURE
GRADIENT AND BITTERLY COLD AIR MASS WILL ENABLE WINDS TO QUICKLY
RAMP UP TO GALE FORCE BY EARLY WEDNESDAY EVENING FOR THE OPEN WATERS
THEN LATER IN THE EVENING FOR THE NEARSHORE. IN ADDITION...HEAVY
FREEZING SPRAY WILL DEVELOP AS AIR TEMPERATURES PLUMMET. HAVE ISSUED
A GALE WARNING AND HEAVY FREEZING SPRAY WARNING FOR THE LAKE
WEDNESDAY EVENING/NIGHT INTO THURSDAY AFTERNOON...WITH A SMALL CRAFT
LEADING UP TO THE GALE WARNING FOR THE NEAR SHORE WEDNESDAY
AFTERNOON AND EVENING. EXPECTING PEAK GUSTS UP TO 40 KT WITH THIS
EVENT...AND THERE IS SOME POTENTIAL FOR UP TO 45 KT IN/NEAR THE
LAKE EFFECT CONVERGENCE BAND EARLY THURSDAY MORNING.
THERE WILL BE ONLY A BRIEF CALMER PERIOD THURSDAY NIGHT INTO
FRIDAY...FOLLOWED BY YET ANOTHER STRONG ARCTIC FRONT SWEEPING ACROSS
THE LAKE FRIDAY EVENING/NIGHT. VERY SIMILAR SETUP TO WEDNESDAY NIGHT
INTO THURSDAY BUT AN EVEN TIGHTER PRESSURE GRADIENT DUE TO STRONGER
LOW PRESSURE TO THE EAST SHOULD RESULT IN AT LEAST GALES TO 45 KT
AND HEAVY FREEZING SPRAY. WINDS...WAVES AND FREEZING SPRAY WILL
DIMINISH LATER SATURDAY NIGHT INTO SUNDAY AS THE ARCTIC HIGH MOVES
OVER THE LAKE.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...NOON WEDNESDAY TO MIDNIGHT THURSDAY.
HEAVY FREEZING SPRAY WARNING...LMZ080-LMZ261-LMZ362-LMZ364-
LMZ366-LMZ563-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-
LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...MIDNIGHT
THURSDAY TO 3 PM THURSDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...MIDNIGHT THURSDAY TO 3 PM THURSDAY.
GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...6 PM WEDNESDAY TO 3 PM
THURSDAY.
&&
$$
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
834 PM CST Tue Feb 10 2015
.UPDATE...
ISSUED AT 825 PM CST TUE FEB 10 2015
Fast moving weather system passing to our north has spread a band
of mid level clouds east into central Illinois this evening. ILX and
DVN 00z soundings indicating a fairly substantial (4-6 deg C) around
850 mb or approx 5000 feet above ground. Have had some reports of
sleet and even some brief light freezing rain/mist near Altona in
northern Knox county over the past hour with the higher dBZs now
headed towards Lacon where a brief period of sleet will be possible
over the next half hour. The band of very light precip was tracking
east at about 35 to 40 mph so its not going to be around our area
too much longer. Have updated the ZFP to include the potential for
a brief period of sleet and possibly a little light snow, but based
on current and forecast soundings, the better bet is with the sleet
for the next hour. Otherwise, cloud cover and a southerly wind
tonight should help keep temperatures from falling off too much
further before a cold front, one of 3 strong fronts to push across
our area over the next week, tracks through central Illinois just
before dawn on Wednesday setting up our area for what appears to
be a windy and very cold stretch of weather.
&&
.SHORT TERM...(Tonight)
ISSUED AT 258 PM CST TUE FEB 10 2015
Stratocumulus clouds 1.5-2k ft are now west of I-55 and eroding and
will continue to decrease toward the nw over IL river valley late
this afternoon into early this evening due to influence of high
pressure ridge axis into IL. HRRR model has been handling the
clearing of low clouds well and will continue to follow its lead.
Broken to overcast mid level clouds 8-12k ft over IA and far nw IL
will spread east across central IL during this evening especially
north of I-72 where skies become mostly cloudy. These clouds ahead
of 1010 mb low pressure along the eastern ND/SD border will track
ene to the Keweenaw peninsula in upper MI by 12Z/6 am Wed with its
cold front moving toward the IL river. Meanwhile southeast IL will
likely stay in the clear most of this evening with skies becoming
partly cloudy overnight in southeast IL. Light mix of precipitation
over eastern IA and moving east into WI and far NW IL at mid
afternoon. Forecast models keep light precipitation north of I-80
tonight over northern IL. Lows tonight in the upper 20s to near 30F
with mildest readings from Springfield southwest. ESE winds less
than 10 mph to veer ssw during overnight and turn WNW nw of IL by
sunrise behind cold front.
&&
.LONG TERM...(Wednesday through Tuesday)
ISSUED AT 258 PM CST TUE FEB 10 2015
The extended will be dominated by large temperature variations,
highlighted by two surges of Arctic air into the western Great Lakes
and eastern CONUS. Precipitation will be light with any shortwaves
through Monday.
The upper ridge along the West Coast will remain a semi-permanent
feature over the 5 to 6 days, with a long wave trough east of the
Continental Divide. A brief push of warm air into the area tonight
ahead of the first cold front should help Wednesday start out with
rising temps possibly even before sunrise. The cold front could
start pushing across our western counties shortly after sunrise, but
the affects of the cold air will be delayed across the rest of the
area until afternoon when the northwest winds increase in the strong
cold air advection. A few light snow showers or flurries could
develop Wed afternoon NE of CMI to DNV where a weak shortwave helps
provide some lift in the advancing cold air. A better chance for
snow showers in our area looks to be Wed night as a strong 500mb
vort max dives south into IL. Any snow accums would be very light
and mainly confined to areas NE of BMI to MTO. Flurries could extend
as far west as Springfield and Taylorville, depending on available
moisture.
Wind chills later Wed night will drop into the -5 to -15F range,
which is just outside of our advisory levels. However, those wind
chill numbers are for the sustained winds, and gusts to 30 mph could
easily push wind chills much colder than that at times.
Thursday will be a blustery day with NW winds of 20-25 and gusts to
35 mph. Some flurries cold linger east of I-57, but the shortwave
aloft will depart east of IL early in the day to help shut down
potential for precip.
Another brief warmup is indicated for Friday, as highs climb toward
freezing in the south and into the upper 20s north.
The strongest surge of Arctic air this week is expected late Friday
night and Saturday, as a deep closed low drops straight south from
the upper latitudes into the Great Lakes region. The coldest air,
with 850 mb temperatures around -25 to -28C, will be over our area
on Saturday. Strong N winds of 25 mph gusting to 40 mph will put
wind chills into the advisory criteria between -15F and -20F
starting Saturday morning across the northern CWA. Those bitterly
cold wind chills appear likely all the way through mid-morning on
Sunday. Temperatures on Sunday will warm slightly, but still remain
well below normal in the teens to around 20. Washington`s
Birthday/Monday looks to be much warmer with highs into the low to
mid 30s as a storm system approaches southern Illinois. Some
indications are for a period of rain or snow in portions of central
IL, with a band of measurable snow possible. The track of that
system has shifted farther south in the 12z GFS, keeping light snow
confined to areas south of I-72, but the ECMWF still has the effects
of the storm reaching well into IL with rain/snow south and snow
north. Will keep chance PoPs across the entire area Monday night for
now. Beyond that, there are indications of yet another push of cold
air for late Tuesday and Tuesday night.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
ISSUED AT 505 PM CST TUE FEB 10 2015
VFR conditions are expected thru this evening into the early
morning hours before a cold front sweeps across the area
after 09z accompanied by MVFR cigs. Most of the lower clouds
have shifted away from the TAF sites late this afternoon and
expect a band of mid level clouds 7000-10,000 feet to push
over the area this evening. Upstream observations not showing
much in the way of precip making it to the ground with this
band of clouds so will not include anything in the early eve.
As the cold front moves thru late tonight, expect low level
moisture to increase behind the front in the cold advection
which will produce the MVFR cigs thru the morning into the
early afternoon hours before we see any improvement later
in the day.
Cigs look to range from 1000-2000 feet behind the cold front
tomorrow morning with forecast soundings suggesting the cloud
bases to increase to around 2500 feet by afternoon. Surface winds
tonight will be from the southeast at 8 to 13kts and then begin to
veer more into a westerly direction after 06z and finally into the
northwest just after FROPA in the 09z-13z time frame. Wind speeds
tomorrow will increase at 12 to 17 kts with a few gusts
approaching 25 kts at times in the afternoon.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...07
LONG TERM...Shimon
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
539 PM CST TUE FEB 10 2015
.SHORT TERM...
345 PM CST
THROUGH THURSDAY...
MAIN FORECAST CONCERNS ARE WITH PRECIP/PRECIP TYPE LATE THIS
AFTERNOON INTO THE OVERNIGHT...LINGERING LIGHT SNOW SHOWERS ON
THURSDAY...AND THEN WITH ACCUMULATING LAKE EFFECT SNOW EXPECTED
LATE WEDNESDAY NIGHT INTO THURSDAY.
LATEST RADAR MOSAIC SHOWING LEADING EDGE OF PRECIP STILL STEADILY
PROGRESSING EAST ACROSS EASTERN IOWA...AND CURRENTLY APPROACHING
FAR NORTHWEST ILLINOIS AT THIS TIME. THIS PRECIP IS RIDING ALONG
WARM ADVECTION WING...OUT AHEAD OF THE SOUTHERN END OF A FAIRLY
STOUT VORT MAX MOVING THROUGH MINNESOTA AND WISCONSIN. WITH THIS
VORT MAX SHIFTING EAST THIS AFTERNOON INTO THE EVENING...LARGE
SCALE ASCENT WILL CONTINUE TO QUICKLY INCREASE ACROSS THE CWA.
PREVIOUSLY MENTIONED DRY AIR IN PLACE IS NOW APPEARING TO BE TOO
MUCH A FACTOR AS FORCING SHOULD BE ABLE TO OVERCOME IT. THIS WILL
LIKELY OCCUR AS SOON AS 23-00Z FOR THE NORTHWEST CWA AND THEN MORE
TOWARDS THE 2-3Z TIME FRAME FOR NORTH CENTRAL AND NORTHEAST
ILLINOIS. DID BRING POPS FURTHER SOUTH TOWARDS THE I80 CORRIDOR
BRIEFLY THIS EVENING...BUT STILL THINK THE BEST CHANCES FOR PRECIP
WILL BE ALONG AND NORTH OF THE I88 CORRIDOR. RAISED POPS TO HIGH
CHANCE POPS...AND LIMITED THEM HERE DUE TO OVERALL DURATION AND
COVERAGE WHICH APPEAR TO BE SMALL. UPON SATURATION...THERMAL
PROFILES WOULD SUGGEST A BRIEF MIX OF SNOW AND SLEET AT THE ONSET
BEFORE A QUICK TRANSITION OVER TO ALL SNOW OCCURS. EXPECT THIS
TREND TO CONTINUE THROUGH THE EVENING BUT WITH ONCE AGAIN SMALLER
WINDOW OF PRECIP EXPECTED...DONT ANTICIPATE MUCH IN TERMS OF ANY
ACCUMULATION. AT MOST WOULD A COUPLE OF TENTHS OF AN INCH OF
SNOWFALL. DEEPER MOISTURE IS LOST MORE TOWARDS 5Z ACROSS MUCH OF
THE CWA...BUT STILL HOVERING AROUND THE POSSIBILITY FOR INCLUSION
OF CRYSTALS. THIS WILL OCCUR THE DEPARTURE OF THE INITIAL
WAVE...BUT WITH THE ARRIVAL OF AN ADDITIONAL WAVE AND SURFACE
TROUGH/FRONT INTO EARLY WEDNESDAY MORNING. COVERAGE AND DURATION
OF ADDITIONAL PRECIP SHOULD ALSO BE SMALL...BUT WITH SNOW AND
FREEZING DRIZZLE THEN POSSIBLE. ANY LINGERING PRECIP SHOULD BE
DEPARTING WEDNESDAY MORNING...BUT WITH A SLIGHT POSSIBILITY FOR
FOR ADDITIONAL SCATTERED LIGHT SNOW SHOWERS POSSIBLE IN THE
AFTERNOON.
LARGE UPPER LEVEL TROUGH WILL BE DIGGING SOUTH ACROSS THE REGION
WEDNESDAY NIGHT...AS A STRONG VORT MAX ROUNDS THE BASE OF THIS
TROUGH. THIS WILL MARK THE ARRIVAL OF A MUCH COLDER AIRMASS AND
WITH THIS STRONG VORT MAX MOVING ACROSS THE AREA...SNOW SHOWERS
WILL LIKELY REDEVELOP WEDNESDAY NIGHT. OF MORE CONCERN IS WITH THE
LAKE EFFECT SNOW SHOWERS EXPECTED ACROSS NORTHWEST INDIANA...LATE
WEDNESDAY NIGHT INTO MUCH OF THURSDAY. AS THIS COLDER AIR SPILLS
SOUTH ACROSS THE LAKE WEDNESDAY NIGHT...THERMODYNAMICS OVER THE
LAKE BECOME HIGHLY CONDUCIVE FOR MODERATE TO HEAVY LAKE EFFECT
SNOW ACROSS THE SOUTHERN END OF THE LAKE. IMPRESSIVE INVERSION
HEIGHT AS WELL AS EVEN MORE IMPRESSIVE DELTA TS COINCIDING WITH
STRONG SYNOPTIC LIFT AND LIKELY STRONG CONVERGENCE WILL ALL BE
PRESENT...BUT WITH CONFIDENCE AS TO WHERE THE BEST SNOW WILL
DEVELOP IS STILL ON THE LOWER SIDE. AM CONFIDENT THAT PORTER
COUNTY WILL OBSERVE SNOW BUT AM NOT AS CONFIDENT WITH THE DURATION
OF THE LIKELY HEAVIER SNOW. CURRENT THINKING/FORECAST IS FOR LAKE
EFFECT TO DEVELOP LATE THURSDAY NIGHT INTO WEDNESDAY MORNING WITH
THE BEST ACCUMULATION DURING THIS TIME. BASED ON THIS...HAVE
ADVISORY LEVEL SNOWFALL TOTALS ACROSS PORTER COUNTY. IF LAKE
EFFECT SNOWBAND WERE TO SETUP ACROSS PORTER COUNTY WHICH IS STILL
A DEFINITE POSSIBILITY...THEN TOTALS COULD EASILY EXCEED 6 INCHES.
WILL NEED TO MONITOR THIS PERIOD FOR THE POTENTIAL OF HIGHER
SNOWFALL TOTALS AND WITH STRONG NORTHERLY WINDS ALSO
EXPECTED...THEN BLOWING AND DRIFTING SNOW COULD EASILY BECOME
ISSUES. AS HIGH PRESSURE BUILDS ACROSS THE REGION AND LOW LEVEL
FLOW BACKS...LAKE EFFECT SHOULD DIMINISH THURSDAY EVENING.
RODRIGUEZ
&&
.LONG TERM...
345 PM CST
THURSDAY NIGHT THROUGH TUESDAY...
HIGH PRESSURE IN PLACE AND THIS COLDER AIRMASS WILL LIKELY PRODUCE
LOW TEMPS IN THE SINGLE DIGITS AND WITH LOCATIONS ACROSS NORTH
CENTRAL ILLINOIS MORE THAN LIKELY FALLING BELOW ZERO. BRIEF LULL
IN THE SNOW WILL END ON FRIDAY AS ANOTHER WAVE PUSHES THROUGH THE
REGION...PRODUCING LIGHT ACCUMULATIONS OVER THE ENTIRE CWA.
ANOTHER PUSH OF COLDER AIR IS APPEARING LIKELY FOR THE WEEKEND AS
ANOTHER LARGE TROUGH DIGS ACROSS THE REGION. DID LOWER TEMPS BELOW
GUIDANCE AS A COLDER TREND IS MORE FAVORED. THIS WILL ALSO HELP
PRODUCE ANOTHER GOOD SETUP FOR LAKE EFFECT SNOW DEVELOPMENT ACROSS
NORTHWEST INDIANA ESPECIALLY SATURDAY AND SATURDAY NIGHT...WITH
SEVERAL INCHES OF SNOW A DISTINCT POSSIBILITY DURING THIS PERIOD.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* POTENTIAL FOR A VERY SHORT PERIOD OF SNOW...POSSIBLY BRIEFLY
MIXED WITH SLEET...THIS EVENING.
* CHANCE OF LIGHT FREEZING DRIZZLE LATE TONIGHT WITH LOWER MVFR
CIGS DEVELOPING.
* LOW MVFR CIGS LATE TONIGHT INTO WEDNESDAY MORNING.
* STRONG GUSTY WEST-NORTHWEST WINDS DEVELOPING BY LATE WEDNESDAY MORNING.
KJB
//DISCUSSION...UPDATED 00Z...
CURRENTLY WATCHING AN AREA OF PRECIPITATION DEVELOPING
ACROSS NORTHWESTERN ILLINOIS AND POINTS NORTHWARD INTO WISCONSIN.
THIS ACTIVITY COULD PRODUCE A SHORT PERIOD OF SNOW/GRAUPEL AT
KRFD OVER THE NEXT COUPLE HOURS...AND POSSIBLY AT SOME OF THE
EASTERN TERMINALS BETWEEN 02 AND 05 UTC THIS EVENING. THERE IS A
GOOD AMOUNT OF DRIER AIR IN THE LOWER LEVELS OF THE
ATMOSPHERE...SO MOST OF THE RADAR ECHOS ARE NOT REACHING THE
GROUND. HOWEVER...GIVEN THE POTENTIAL FOR SOME MORE ROBUST
CONVECTIVE CELLS...PERIODS OF SNOW AND OR GRAUPEL COULD BEGIN TO
REACH THE SURFACE AS IT BEGINS TO MOISTEN THE LOWER LEVELS. BRIEF
PERIODS OF IFR OR LOWER VISIBILITIES COULD RESULT IN THE HEAVIER
PRECIPITATION.
LOWER CLOUDS SHOULD BEGIN TO DEVELOP OVER THE AREA LATE TONIGHT INTO
WEDNESDAY MORNING. SOME AREAS OF -FZDZ COULD ALSO ACCOMPANY THESE
LOWER CIGS. HOWEVER...CONFIDENCE ON THE EXTENT OF -FZDZ LATER
TONIGHT REMAINS LOW.
A COLD FRONT WILL SHIFT ACROSS THE AREA BY LATE WEDNESDAY MORNING.
WINDS BEHIND THIS FRONT ARE EXPECTED TO RAPIDLY BECOME GUSTY OUT
OF THE WEST-NORTHWEST. CURRENT INDICATIONS ARE THAT WINDS WILL GUST
IN THE 25 TO 30 KT RANGE DURING THE AFTERNOON AND EVENING ON
WEDNESDAY. AN ARCTIC AIRMASS IS EXPECTED TO BEGIN SHIFTING SOUTHWARD
OVER THE AREA WEDNESDAY EVENING AS AN UPPER AIR DISTURBANCE
APPROACHES. THIS COULD RESULT IN SOME SNOW SHOWERS AND REDUCED
VISIBILITIES OVER THE AREA WEDNESDAY EVENING AND NIGHT.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM TO HIGH IN WIND TRENDS THROUGH THE PERIOD.
* LOW WITH THE PERIOD OF LIGHT SNOW/GRAUPEL THIS
EVENING.
* LOW TO MEDIUM CONFIDENCE IN FREEZING DRIZZLE LATE TONIGHT.
* MEDIUM TO HIGH CONFIDENCE IN LOW MVFR CIGS LATE TONIGHT INTO
WEDNESDAY MORNING.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
* THURSDAY...MVFR CIGS POSSIBLE EARLY. STRONG/GUSTY NORTHWEST WINDS.
* FRIDAY...SLIGHT CHANCE OF SNOW. MVFR POSSIBLE. WEST/SOUTHWEST
WINDS.
* SATURDAY...CHANCE OF FLURRIES. MVFR POSSIBLE. VERY STRONG/GUSTY
NORTHWEST WINDS.
* SUNDAY...DRY/VFR. WEST/SOUTHWEST WINDS.
* MONDAY...MVFR POSSIBLE. SOUTHWEST WINDS.
KJB
&&
.MARINE...
322 PM CST
MULTIPLE MARINE CONCERNS AS WE ENTER A VERY COLD AND ACTIVE PATTERN.
THIS EVENING...THERE COULD BE BRIEF WINDOW OF NEAR SMALL CRAFT
CONDITIONS ALONG THE FAR NORTHEAST ILLINOIS SHORE AS SOUTHEAST
WINDS INCREASE TO 15 TO 25 KT. WINDS WILL THEN SHIFT SOUTHERLY ON
THE ENTIRE LAKE AS A WEAK LOW OVER THE UPPER MIDWEST APPROACHES.
THERE COULD BE A FEW GUSTS TO 30 KT ON THE NORTHERN HALF OF THE
LAKE TONIGHT IN THE PEAK OF THE SOUTHERLY FLOW.
A STRONG COLD FRONT TRAILING FROM THE LOW WILL SWEEP ACROSS THE LAKE
BY MID DAY WEDNESDAY OR SO...WITH AN EXPANSIVE 1040+ MB ARCTIC HIGH
SPREADING IN FROM THE NORTHERN PLAINS BEHIND IT. VERY TIGHT PRESSURE
GRADIENT AND BITTERLY COLD AIR MASS WILL ENABLE WINDS TO QUICKLY
RAMP UP TO GALE FORCE BY EARLY WEDNESDAY EVENING FOR THE OPEN WATERS
THEN LATER IN THE EVENING FOR THE NEARSHORE. IN ADDITION...HEAVY
FREEZING SPRAY WILL DEVELOP AS AIR TEMPERATURES PLUMMET. HAVE ISSUED
A GALE WARNING AND HEAVY FREEZING SPRAY WARNING FOR THE LAKE
WEDNESDAY EVENING/NIGHT INTO THURSDAY AFTERNOON...WITH A SMALL CRAFT
LEADING UP TO THE GALE WARNING FOR THE NEAR SHORE WEDNESDAY
AFTERNOON AND EVENING. EXPECTING PEAK GUSTS UP TO 40 KT WITH THIS
EVENT...AND THERE IS SOME POTENTIAL FOR UP TO 45 KT IN/NEAR THE
LAKE EFFECT CONVERGENCE BAND EARLY THURSDAY MORNING.
THERE WILL BE ONLY A BRIEF CALMER PERIOD THURSDAY NIGHT INTO
FRIDAY...FOLLOWED BY YET ANOTHER STRONG ARCTIC FRONT SWEEPING ACROSS
THE LAKE FRIDAY EVENING/NIGHT. VERY SIMILAR SETUP TO WEDNESDAY NIGHT
INTO THURSDAY BUT AN EVEN TIGHTER PRESSURE GRADIENT DUE TO STRONGER
LOW PRESSURE TO THE EAST SHOULD RESULT IN AT LEAST GALES TO 45 KT
AND HEAVY FREEZING SPRAY. WINDS...WAVES AND FREEZING SPRAY WILL
DIMINISH LATER SATURDAY NIGHT INTO SUNDAY AS THE ARCTIC HIGH MOVES
OVER THE LAKE.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...NOON WEDNESDAY TO MIDNIGHT THURSDAY.
HEAVY FREEZING SPRAY WARNING...LMZ080-LMZ261-LMZ362-LMZ364-
LMZ366-LMZ563-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-
LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...MIDNIGHT
THURSDAY TO 3 PM THURSDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...MIDNIGHT THURSDAY TO 3 PM THURSDAY.
GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...6 PM WEDNESDAY TO 3 PM
THURSDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
508 PM CST Tue Feb 10 2015
.SHORT TERM...(Tonight)
ISSUED AT 258 PM CST TUE FEB 10 2015
Stratocumulus clouds 1.5-2k ft are now west of I-55 and eroding and
will continue to decrease toward the nw over IL river valley late
this afternoon into early this evening due to influence of high
pressure ridge axis into IL. HRRR model has been handling the
clearing of low clouds well and will continue to follow its lead.
Broken to overcast mid level clouds 8-12k ft over IA and far nw IL
will spread east across central IL during this evening especially
north of I-72 where skies become mostly cloudy. These clouds ahead
of 1010 mb low pressure along the eastern ND/SD border will track
ene to the Keweenaw peninsula in upper MI by 12Z/6 am Wed with its
cold front moving toward the IL river. Meanwhile southeast IL will
likely stay in the clear most of this evening with skies becoming
partly cloudy overnight in southeast IL. Light mix of precipitation
over eastern IA and moving east into WI and far NW IL at mid
afternoon. Forecast models keep light precipitation north of I-80
tonight over northern IL. Lows tonight in the upper 20s to near 30F
with mildest readings from Springfield southwest. ESE winds less
than 10 mph to veer ssw during overnight and turn WNW nw of IL by
sunrise behind cold front.
&&
.LONG TERM...(Wednesday through Tuesday)
ISSUED AT 258 PM CST TUE FEB 10 2015
The extended will be dominated by large temperature variations,
highlighted by two surges of Arctic air into the western Great Lakes
and eastern CONUS. Precipitation will be light with any shortwaves
through Monday.
The upper ridge along the West Coast will remain a semi-permanent
feature over the 5 to 6 days, with a long wave trough east of the
Continental Divide. A brief push of warm air into the area tonight
ahead of the first cold front should help Wednesday start out with
rising temps possibly even before sunrise. The cold front could
start pushing across our western counties shortly after sunrise, but
the affects of the cold air will be delayed across the rest of the
area until afternoon when the northwest winds increase in the strong
cold air advection. A few light snow showers or flurries could
develop Wed afternoon NE of CMI to DNV where a weak shortwave helps
provide some lift in the advancing cold air. A better chance for
snow showers in our area looks to be Wed night as a strong 500mb
vort max dives south into IL. Any snow accums would be very light
and mainly confined to areas NE of BMI to MTO. Flurries could extend
as far west as Springfield and Taylorville, depending on available
moisture.
Wind chills later Wed night will drop into the -5 to -15F range,
which is just outside of our advisory levels. However, those wind
chill numbers are for the sustained winds, and gusts to 30 mph could
easily push wind chills much colder than that at times.
Thursday will be a blustery day with NW winds of 20-25 and gusts to
35 mph. Some flurries cold linger east of I-57, but the shortwave
aloft will depart east of IL early in the day to help shut down
potential for precip.
Another brief warmup is indicated for Friday, as highs climb toward
freezing in the south and into the upper 20s north.
The strongest surge of Arctic air this week is expected late Friday
night and Saturday, as a deep closed low drops straight south from
the upper latitudes into the Great Lakes region. The coldest air,
with 850 mb temperatures around -25 to -28C, will be over our area
on Saturday. Strong N winds of 25 mph gusting to 40 mph will put
wind chills into the advisory criteria between -15F and -20F
starting Saturday morning across the northern CWA. Those bitterly
cold wind chills appear likely all the way through mid-morning on
Sunday. Temperatures on Sunday will warm slightly, but still remain
well below normal in the teens to around 20. Washington`s
Birthday/Monday looks to be much warmer with highs into the low to
mid 30s as a storm system approaches southern Illinois. Some
indications are for a period of rain or snow in portions of central
IL, with a band of measurable snow possible. The track of that
system has shifted farther south in the 12z GFS, keeping light snow
confined to areas south of I-72, but the ECMWF still has the effects
of the storm reaching well into IL with rain/snow south and snow
north. Will keep chance PoPs across the entire area Monday night for
now. Beyond that, there are indications of yet another push of cold
air for late Tuesday and Tuesday night.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
ISSUED AT 505 PM CST TUE FEB 10 2015
VFR conditions are expected thru this evening into the early
morning hours before a cold front sweeps across the area
after 09z accompanied by MVFR cigs. Most of the lower clouds
have shifted away from the TAF sites late this afternoon and
expect a band of mid level clouds 7000-10,000 feet to push
over the area this evening. Upstream observations not showing
much in the way of precip making it to the ground with this
band of clouds so will not include anything in the early eve.
As the cold front moves thru late tonight, expect low level
moisture to increase behind the front in the cold advection
which will produce the MVFR cigs thru the morning into the
early afternoon hours before we see any improvement later
in the day.
Cigs look to range from 1000-2000 feet behind the cold front
tomorrow morning with forecast soundings suggesting the cloud
bases to increase to around 2500 feet by afternoon. Surface winds
tonight will be from the southeast at 8 to 13kts and then begin to
veer more into a westerly direction after 06z and finally into the
northwest just after FROPA in the 09z-13z time frame. Wind speeds
tomorrow will increase at 12 to 17 kts with a few gusts
approaching 25 kts at times in the afternoon.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...Shimon
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1248 PM EST MON FEB 9 2015
.SYNOPSIS...
ISSUED AT 1059 AM EST MON FEB 9 2015
HIGH PRESSURE WILL BE MOVING INTO THE AREA TODAY AND TONIGHT.
SKIES WILL BE MOSTLY CLOUDY TODAY AND THEN BEGIN CLEARING UP
TONIGHT. HIGH TEMPERATURES TODAY WILL RANGE FROM THE LOWER 20S IN
SOUTHERN MICHIGAN TO THE LOWER 30S ALONG THE OHIO RIVER. LOWS
TONIGHT WILL RANGE FROM SINGLE DIGITS ABOVE ZERO IN SOUTHERN
MICHIGAN TO THE LOWER 20S ALONG THE OHIO RIVER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM EST MON FEB 9 2015
MUCH QUIETER PERIOD IN STORE WITH ONLY FORECAST ISSUES BEING ENDING
OF PATCHY FREEZING DRIZZLE AND WHEN/IF SKIES BEGIN TO CLEAR LATER
TODAY INTO TONIGHT.
SOME WEAK LIFT WAS REMAINING AHEAD OF A SHORT WAVE DROPPING THROUGH
THE AREA. RADAR RETURNS HAVE BEEN INCREASING AND A FEW
SPOTS...INCLUDING HERE AT THE OFFICE...HAVE BEEN SEEING SOME VERY
LIGHT FREEZING DRIZZLE COURTESY OF THE LOSS OF ANY ICE CRYSTAL
DEVELOPMENT IN THE CLOUDS. HAVE EXPANDED PATCHY FZDZ FOR SE HALF OF
THE AREA THROUGH 11Z BEFORE ENDING AS WAVE EXIT THE AREA. DON`T
ANTICIPATE ANY ICING ISSUES BUT A FEW SLICK SPOTS ARE POSSIBLE.
GREATER CONCERN IN TERMS OF ROADS WILL LIKELY BE FROM RECENT
MELTED SNOW REFREEZING ON SURFACES.
EXTENSIVE CLOUD COVER...COMBINED WITH CONTINUED ADVECTION OF COLDER
AIR...WILL CAUSE LITTLE IN THE WAY OF AN UPTICK IN TEMPS TODAY WITH
MOST AREAS MAYBE SEEING A 3 TO 5 DEGREE CLIMB AT BEST BY LATE
AFTERNOON. BACK EDGE OF STRATUS WAS LOCATED FROM ALPENA MI TO NEAR
GREEN BAY AND WAS MOVING SLOWLY SOUTH. 6Z RUN OF NAM TRIES TO BRING
CLEARING INTO PARTS OF THE AREA BY MID AFTERNOON WITH THE RUC AND
LOCAL WRF A TOUCH SLOWER...MORE CLOSER TO 00Z. HAVE KEPT WITH SLOWER
TREND FOR NOW WITH SOME THIN SPOTS LIKELY TO APPEAR BY LATE
AFTERNOON IN THE NORTH.
CLEARING SKIES TONIGHT WILL ALLOW FOR TEMPS TO DROP INTO THE TEENS
SOUTH OF ROUTE 30 AND SINGLE DIGITS NORTH. MAY NOT BE COLD ENOUGH IN
THE NORTH IF SKIES GO COMPLETELY CLEAR. DID MAKE MINOR ADJUSTMENTS
FAR NORTH/NE.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 333 AM EST MON FEB 9 2015
ARCTIC STREAM SW OVR WRN NUNAVUT THIS MORNING WILL AMPLIFY SEWD EARLY
IN THE PD AND MARKEDLY DEEPEN ERN NOAM TROUGHING AS SECONDARY ARCTIC
WAVE FOLLOWS LT PD. THIS WILL BRING ABOUT THE COLDEST AIR OF THE
SEASON SO FAR W/TEMP DEPARTURES OF 20+ DEGREES BLO NORMAL LIKELY FOR
MOST OF THE PD.
LEAD ARCTIC DISTURBANCE WILL DIG ACRS THE LAKES ON WED W/GENERALLY
LTL FANFARE LOCALLY AS SW AND ASSOCD MSTR PLUME PASS WELL NORTH AND
DISCOUNTED ALLBLEND POPS W/GROSS MODEL CONSENSUS HOLDING DRY HERE.
HWVR PASSAGE OF ARCTIC SFC BNDRY WED NIGHT ALG W/VIGOROUS HGT FALLS
ALOFT TIED TO SHARPENING H7-5 TROUGH ALOFT AND MORE FVRBL CYCLONIC
LL FLW TRAJECTORIES WITHIN BLOSSOMING LK AGGREGATE TROUGHING WARRANT
AN APPRECIABLE BOOST TO LK EFFECT SHSN CONTG INTO THU. AHD OF THIS
FTR...LOW AMPLITUDE RIDGING WILL MAKE WED THE WARMEST DAY OF THE PD.
SECONDARY FOLLOWING ARCTIC WAVE WILL DROP DOWN ACRS THE LAKES FRI
NIGHT W/LK EFFECT LIKELY DVLPG IN ITS WAKE LT FRI NIGHT THROUGH SAT.
OTRWS TEMPS TURNING SHARPLY COLDER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1231 PM EST MON FEB 9 2015
STRATUS DECK HAS HELD STRONG ACROSS THE AREA THROUGH MID DAY. A
COLD...DRY HIGH PRESSURE IS MOVING SOUTH OUT OF THE NORTHERN
PLAINS AND WILL CAUSE THE STRATUS DECK TO SCATTER OUT BY LATE
THIS EVENING. WINDS WILL WEAKEN TO THE 5 KT OR LESS RANGE BY THE
OVERNIGHT HOURS AS A COLD ARCTIC HIGH MOVES OVERHEAD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LOTHAMER
SHORT TERM...FISHER
LONG TERM...T
AVIATION...BENTLEY
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1109 AM EST MON FEB 9 2015
.SYNOPSIS...
ISSUED AT 1059 AM EST MON FEB 9 2015
HIGH PRESSURE WILL BE MOVING INTO THE AREA TODAY AND TONIGHT.
SKIES WILL BE MOSTLY CLOUDY TODAY AND THEN BEGIN CLEARING UP
TONIGHT. HIGH TEMPERATURES TODAY WILL RANGE FROM THE LOWER 20S IN
SOUTHERN MICHIGAN TO THE LOWER 30S ALONG THE OHIO RIVER. LOWS
TONIGHT WILL RANGE FROM SINGLE DIGITS ABOVE ZERO IN SOUTHERN
MICHIGAN TO THE LOWER 20S ALONG THE OHIO RIVER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM EST MON FEB 9 2015
MUCH QUIETER PERIOD IN STORE WITH ONLY FORECAST ISSUES BEING ENDING
OF PATCHY FREEZING DRIZZLE AND WHEN/IF SKIES BEGIN TO CLEAR LATER
TODAY INTO TONIGHT.
SOME WEAK LIFT WAS REMAINING AHEAD OF A SHORT WAVE DROPPING THROUGH
THE AREA. RADAR RETURNS HAVE BEEN INCREASING AND A FEW
SPOTS...INCLUDING HERE AT THE OFFICE...HAVE BEEN SEEING SOME VERY
LIGHT FREEZING DRIZZLE COURTESY OF THE LOSS OF ANY ICE CRYSTAL
DEVELOPMENT IN THE CLOUDS. HAVE EXPANDED PATCHY FZDZ FOR SE HALF OF
THE AREA THROUGH 11Z BEFORE ENDING AS WAVE EXIT THE AREA. DON`T
ANTICIPATE ANY ICING ISSUES BUT A FEW SLICK SPOTS ARE POSSIBLE.
GREATER CONCERN IN TERMS OF ROADS WILL LIKELY BE FROM RECENT
MELTED SNOW REFREEZING ON SURFACES.
EXTENSIVE CLOUD COVER...COMBINED WITH CONTINUED ADVECTION OF COLDER
AIR...WILL CAUSE LITTLE IN THE WAY OF AN UPTICK IN TEMPS TODAY WITH
MOST AREAS MAYBE SEEING A 3 TO 5 DEGREE CLIMB AT BEST BY LATE
AFTERNOON. BACK EDGE OF STRATUS WAS LOCATED FROM ALPENA MI TO NEAR
GREEN BAY AND WAS MOVING SLOWLY SOUTH. 6Z RUN OF NAM TRIES TO BRING
CLEARING INTO PARTS OF THE AREA BY MID AFTERNOON WITH THE RUC AND
LOCAL WRF A TOUCH SLOWER...MORE CLOSER TO 00Z. HAVE KEPT WITH SLOWER
TREND FOR NOW WITH SOME THIN SPOTS LIKELY TO APPEAR BY LATE
AFTERNOON IN THE NORTH.
CLEARING SKIES TONIGHT WILL ALLOW FOR TEMPS TO DROP INTO THE TEENS
SOUTH OF ROUTE 30 AND SINGLE DIGITS NORTH. MAY NOT BE COLD ENOUGH IN
THE NORTH IF SKIES GO COMPLETELY CLEAR. DID MAKE MINOR ADJUSTMENTS
FAR NORTH/NE.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 333 AM EST MON FEB 9 2015
ARCTIC STREAM SW OVR WRN NUNAVUT THIS MORNING WILL AMPLIFY SEWD EARLY
IN THE PD AND MARKEDLY DEEPEN ERN NOAM TROUGHING AS SECONDARY ARCTIC
WAVE FOLLOWS LT PD. THIS WILL BRING ABOUT THE COLDEST AIR OF THE
SEASON SO FAR W/TEMP DEPARTURES OF 20+ DEGREES BLO NORMAL LIKELY FOR
MOST OF THE PD.
LEAD ARCTIC DISTURBANCE WILL DIG ACRS THE LAKES ON WED W/GENERALLY
LTL FANFARE LOCALLY AS SW AND ASSOCD MSTR PLUME PASS WELL NORTH AND
DISCOUNTED ALLBLEND POPS W/GROSS MODEL CONSENSUS HOLDING DRY HERE.
HWVR PASSAGE OF ARCTIC SFC BNDRY WED NIGHT ALG W/VIGOROUS HGT FALLS
ALOFT TIED TO SHARPENING H7-5 TROUGH ALOFT AND MORE FVRBL CYCLONIC
LL FLW TRAJECTORIES WITHIN BLOSSOMING LK AGGREGATE TROUGHING WARRANT
AN APPRECIABLE BOOST TO LK EFFECT SHSN CONTG INTO THU. AHD OF THIS
FTR...LOW AMPLITUDE RIDGING WILL MAKE WED THE WARMEST DAY OF THE PD.
SECONDARY FOLLOWING ARCTIC WAVE WILL DROP DOWN ACRS THE LAKES FRI
NIGHT W/LK EFFECT LIKELY DVLPG IN ITS WAKE LT FRI NIGHT THROUGH SAT.
OTRWS TEMPS TURNING SHARPLY COLDER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 630 AM EST MON FEB 9 2015
IFR CONDITIONS HOLDING STRONG AT KFWA WITH FREEZING DRIZZLE
PERSISTING FOR PAST SEVERAL HOURS. TRENDS SUGGEST THE FZDZ SHOULD
END OVER THE NEXT COUPLE OF HOURS SO HAVE WENT WITH PREDOMINATE
MENTION THROUGH 14Z AND WILL DEFER TO DAY SHIFT TO MONITOR TRENDS.
AS FOR KSBN...MVFR CIGS IN PLACE WITH BRIEF EXCURTIONS TO VFR IN
NARROW AREA OF IMPROVED CONDITIONS. 2 OF THE HI RES MODELS
SUGGESTED THIS MAY OCCUR AND SHOW THE CURRENT CONDITIONS HOLDING
ON. BIT SKEPTICAL THAT IT CAN HOLD ON TO THE HIGHER CIGS GIVEN
UPSTREAM OBS. HOWEVER...HAS BEEN THE CASE NOW FOR OVER 3 HOURS SO
MAY BE SOME INFLUENCE FROM LK MICHIGAN AND THE NE FLOW. WILL GO WITH
CONTINUED MVFR THROUGH LATE AFTERNOON.
LATER THIS EVENING DRY AIR SHOULD MOVE FAR ENOUGH SOUTH TO BRING
VFR CONDITIONS TO BOTH SITES WITH QUIET WEATHER OVERNIGHT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LOTHAMER
SHORT TERM...FISHER
LONG TERM...T
AVIATION...FISHER
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
635 AM EST MON FEB 9 2015
.SYNOPSIS...
ISSUED AT 333 AM EST MON FEB 9 2015
HIGH PRESSURE WILL BUILD INTO THE REGION INTO TONIGHT...BRINGING
DRIER BUT COLDER WEATHER. SKIES WILL CLEAR FROM NORTH TO
SOUTH THIS AFTERNOON AND EVENING. TEMPERATURES WILL NOT WARM MUCH
TODAY...ONLY REACHING MID 20S. MOSTLY CLEAR SKIES WILL ALLOW
OVERNIGHT LOWS TO RANGE FROM THE SINGLE DIGITS NORTH TO THE TEENS
SOUTH.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM EST MON FEB 9 2015
MUCH QUIETER PERIOD IN STORE WITH ONLY FORECAST ISSUES BEING ENDING
OF PATCHY FREEZING DRIZZLE AND WHEN/IF SKIES BEGIN TO CLEAR LATER
TODAY INTO TONIGHT.
SOME WEAK LIFT WAS REMAINING AHEAD OF A SHORT WAVE DROPPING THROUGH
THE AREA. RADAR RETURNS HAVE BEEN INCREASING AND A FEW
SPOTS...INCLUDING HERE AT THE OFFICE...HAVE BEEN SEEING SOME VERY
LIGHT FREEZING DRIZZLE COURTESY OF THE LOSS OF ANY ICE CRYSTAL
DEVELOPMENT IN THE CLOUDS. HAVE EXPANDED PATCHY FZDZ FOR SE HALF OF
THE AREA THROUGH 11Z BEFORE ENDING AS WAVE EXIT THE AREA. DON`T
ANTICIPATE ANY ICING ISSUES BUT A FEW SLICK SPOTS ARE POSSIBLE.
GREATER CONCERN IN TERMS OF ROADS WILL LIKELY BE FROM RECENT
MELTED SNOW REFREEZING ON SURFACES.
EXTENSIVE CLOUD COVER...COMBINED WITH CONTINUED ADVECTION OF COLDER
AIR...WILL CAUSE LITTLE IN THE WAY OF AN UPTICK IN TEMPS TODAY WITH
MOST AREAS MAYBE SEEING A 3 TO 5 DEGREE CLIMB AT BEST BY LATE
AFTERNOON. BACK EDGE OF STRATUS WAS LOCATED FROM ALPENA MI TO NEAR
GREEN BAY AND WAS MOVING SLOWLY SOUTH. 6Z RUN OF NAM TRIES TO BRING
CLEARING INTO PARTS OF THE AREA BY MID AFTERNOON WITH THE RUC AND
LOCAL WRF A TOUCH SLOWER...MORE CLOSER TO 00Z. HAVE KEPT WITH SLOWER
TREND FOR NOW WITH SOME THIN SPOTS LIKELY TO APPEAR BY LATE
AFTERNOON IN THE NORTH.
CLEARING SKIES TONIGHT WILL ALLOW FOR TEMPS TO DROP INTO THE TEENS
SOUTH OF ROUTE 30 AND SINGLE DIGITS NORTH. MAY NOT BE COLD ENOUGH IN
THE NORTH IF SKIES GO COMPLETELY CLEAR. DID MAKE MINOR ADJUSTMENTS
FAR NORTH/NE.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 333 AM EST MON FEB 9 2015
ARCTIC STREAM SW OVR WRN NUNAVUT THIS MORNING WILL AMPLIFY SEWD EARLY
IN THE PD AND MARKEDLY DEEPEN ERN NOAM TROUGHING AS SECONDARY ARCTIC
WAVE FOLLOWS LT PD. THIS WILL BRING ABOUT THE COLDEST AIR OF THE
SEASON SO FAR W/TEMP DEPARTURES OF 20+ DEGREES BLO NORMAL LIKELY FOR
MOST OF THE PD.
LEAD ARCTIC DISTURBANCE WILL DIG ACRS THE LAKES ON WED W/GENERALLY
LTL FANFARE LOCALLY AS SW AND ASSOCD MSTR PLUME PASS WELL NORTH AND
DISCOUNTED ALLBLEND POPS W/GROSS MODEL CONSENSUS HOLDING DRY HERE.
HWVR PASSAGE OF ARCTIC SFC BNDRY WED NIGHT ALG W/VIGOROUS HGT FALLS
ALOFT TIED TO SHARPENING H7-5 TROUGH ALOFT AND MORE FVRBL CYCLONIC
LL FLW TRAJECTORIES WITHIN BLOSSOMING LK AGGREGATE TROUGHING WARRANT
AN APPRECIABLE BOOST TO LK EFFECT SHSN CONTG INTO THU. AHD OF THIS
FTR...LOW AMPLITUDE RIDGING WILL MAKE WED THE WARMEST DAY OF THE PD.
SECONDARY FOLLOWING ARCTIC WAVE WILL DROP DOWN ACRS THE LAKES FRI
NIGHT W/LK EFFECT LIKELY DVLPG IN ITS WAKE LT FRI NIGHT THROUGH SAT.
OTRWS TEMPS TURNING SHARPLY COLDER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 630 AM EST MON FEB 9 2015
IFR CONDITIONS HOLDING STRONG AT KFWA WITH FREEZING DRIZZLE
PERSISTING FOR PAST SEVERAL HOURS. TRENDS SUGGEST THE FZDZ SHOULD
END OVER THE NEXT COUPLE OF HOURS SO HAVE WENT WITH PREDOMINATE
MENTION THROUGH 14Z AND WILL DEFER TO DAY SHIFT TO MONITOR TRENDS.
AS FOR KSBN...MVFR CIGS IN PLACE WITH BRIEF EXCURTIONS TO VFR IN
NARROW AREA OF IMPROVED CONDITIONS. 2 OF THE HI RES MODELS
SUGGESTED THIS MAY OCCUR AND SHOW THE CURRENT CONDITIONS HOLDING
ON. BIT SKEPTICAL THAT IT CAN HOLD ON TO THE HIGHER CIGS GIVEN
UPSTREAM OBS. HOWEVER...HAS BEEN THE CASE NOW FOR OVER 3 HOURS SO
MAY BE SOME INFLUENCE FROM LK MICHIGAN AND THE NE FLOW. WILL GO WITH
CONTINUED MVFR THROUGH LATE AFTERNOON.
LATER THIS EVENING DRY AIR SHOULD MOVE FAR ENOUGH SOUTH TO BRING
VFR CONDITIONS TO BOTH SITES WITH QUIET WEATHER OVERNIGHT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...FISHER
SHORT TERM...FISHER
LONG TERM...T
AVIATION...FISHER
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
341 AM EST MON FEB 9 2015
.SYNOPSIS...
ISSUED AT 333 AM EST MON FEB 9 2015
HIGH PRESSURE WILL BUILD INTO THE REGION INTO TONIGHT...BRINGING
DRIER BUT COLDER WEATHER. SKIES WILL CLEAR FROM NORTH TO
SOUTH THIS AFTERNOON AND EVENING. TEMPERATURES WILL NOT WARM MUCH
TODAY...ONLY REACHING MID 20S. MOSTLY CLEAR SKIES WILL ALLOW
OVERNIGHT LOWS TO RANGE FROM THE SINGLE DIGITS NORTH TO THE TEENS
SOUTH.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM EST MON FEB 9 2015
MUCH QUIETER PERIOD IN STORE WITH ONLY FORECAST ISSUES BEING ENDING
OF PATCHY FREEZING DRIZZLE AND WHEN/IF SKIES BEGIN TO CLEAR LATER
TODAY INTO TONIGHT.
SOME WEAK LIFT WAS REMAINING AHEAD OF A SHORT WAVE DROPPING THROUGH
THE AREA. RADAR RETURNS HAVE BEEN INCREASING AND A FEW
SPOTS...INCLUDING HERE AT THE OFFICE...HAVE BEEN SEEING SOME VERY
LIGHT FREEZING DRIZZLE COURTESY OF THE LOSS OF ANY ICE CRYSTAL
DEVELOPMENT IN THE CLOUDS. HAVE EXPANDED PATCHY FZDZ FOR SE HALF OF
THE AREA THROUGH 11Z BEFORE ENDING AS WAVE EXIT THE AREA. DON`T
ANTICIPATE ANY ICING ISSUES BUT A FEW SLICK SPOTS ARE POSSIBLE.
GREATER CONCERN IN TERMS OF ROADS WILL LIKELY BE FROM RECENT
MELTED SNOW REFREEZING ON SURFACES.
EXTENSIVE CLOUD COVER...COMBINED WITH CONTINUED ADVECTION OF COLDER
AIR...WILL CAUSE LITTLE IN THE WAY OF AN UPTICK IN TEMPS TODAY WITH
MOST AREAS MAYBE SEEING A 3 TO 5 DEGREE CLIMB AT BEST BY LATE
AFTERNOON. BACK EDGE OF STRATUS WAS LOCATED FROM ALPENA MI TO NEAR
GREEN BAY AND WAS MOVING SLOWLY SOUTH. 6Z RUN OF NAM TRIES TO BRING
CLEARING INTO PARTS OF THE AREA BY MID AFTERNOON WITH THE RUC AND
LOCAL WRF A TOUCH SLOWER...MORE CLOSER TO 00Z. HAVE KEPT WITH SLOWER
TREND FOR NOW WITH SOME THIN SPOTS LIKELY TO APPEAR BY LATE
AFTERNOON IN THE NORTH.
CLEARING SKIES TONIGHT WILL ALLOW FOR TEMPS TO DROP INTO THE TEENS
SOUTH OF ROUTE 30 AND SINGLE DIGITS NORTH. MAY NOT BE COLD ENOUGH IN
THE NORTH IF SKIES GO COMPLETELY CLEAR. DID MAKE MINOR ADJUSTMENTS
FAR NORTH/NE.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 333 AM EST MON FEB 9 2015
ARCTIC STREAM SW OVR WRN NUNAVUT THIS MORNING WILL AMPLIFY SEWD EARLY
IN THE PD AND MARKEDLY DEEPEN ERN NOAM TROUGHING AS SECONDARY ARCTIC
WAVE FOLLOWS LT PD. THIS WILL BRING ABOUT THE COLDEST AIR OF THE
SEASON SO FAR W/TEMP DEPARTURES OF 20+ DEGREES BLO NORMAL LIKELY FOR
MOST OF THE PD.
LEAD ARCTIC DISTURBANCE WILL DIG ACRS THE LAKES ON WED W/GENERALLY
LTL FANFARE LOCALLY AS SW AND ASSOCD MSTR PLUME PASS WELL NORTH AND
DISCOUNTED ALLBLEND POPS W/GROSS MODEL CONSENSUS HOLDING DRY HERE.
HWVR PASSAGE OF ARCTIC SFC BNDRY WED NIGHT ALG W/VIGOROUS HGT FALLS
ALOFT TIED TO SHARPENING H7-5 TROUGH ALOFT AND MORE FVRBL CYCLONIC
LL FLW TRAJECTORIES WITHIN BLOSSOMING LK AGGREGATE TROUGHING WARRANT
AN APPRECIABLE BOOST TO LK EFFECT SHSN CONTG INTO THU. AHD OF THIS
FTR...LOW AMPLITUDE RIDGING WILL MAKE WED THE WARMEST DAY OF THE PD.
SECONDARY FOLLOWING ARCTIC WAVE WILL DROP DOWN ACRS THE LAKES FRI
NIGHT W/LK EFFECT LIKELY DVLPG IN ITS WAKE LT FRI NIGHT THROUGH SAT.
OTRWS TEMPS TURNING SHARPLY COLDER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1239 AM EST MON FEB 9 2015
COLDER AIR WAS SWEEPING ACROSS THE AREA WITH NORTH TO NORTHEAST
WINDS DOMINATING AT BOTH SITES. HIT AND MISS FREEZING RAIN/SNOW
MAY IMPACT KFWA FOR A FEW MORE HOURS BEFORE SHIFTING EAST.
UPSTREAM TRENDS ONLY SHOWING A FEW POCKETS OF FREEZING DRIZZLE SO
WILL RUN WITH TEMPO FOR A FEW HOURS AT ONSET AND LEAVE AT THAT FOR NOW.
HAVE LEFT IFR CONDITIONS THROUGH THE NIGHT WITH SLOW IMPROVEMENT
INTO MVFR AFTER 12Z. HI RES MODELS SPLIT ON WHETHER STRATUS
REMAINS OR NOT INTO TONIGHT. TRENDS ACROSS NORTHERN MICHIGAN SHOW
SUBSIDENCE TAKING PLACE WITH HINTS OF A SOUTHWARD SHIFT WHICH
LOCAL WRF DEPICTS. FOR NOW WILL LEAVE MVFR CONDITIONS THROUGH 06Z
BUT MAY BE ABLE TO IMPROVE FURTHER TO VFR WITH 12Z ISSUANCE.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...FISHER
SHORT TERM...FISHER
LONG TERM...T
AVIATION...FISHER
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DES MOINES IA
328 PM CST MON FEB 9 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 328 PM CST MON FEB 9 2015
MAIN CONCERNS ARE CLOUD COVER AND APPROACHING WAVE FROM THE WEST.
LOW STRATUS ERODING OVER THE NORTH MOMENTARILY BUT SHOULD BEGIN TO
FILL BACK IN AFTER SUNSET. THE HRRR SHOWS THE CURRENT SETUP QUITE
WELL WITH SOME THINNING OF THE CLOUD DECK OVER THE NORTH FOLLOWED
BY CLOUDS FILLING IN ONCE AGAIN. THE UPSTREAM SHORT WAVE OVER MT
WILL MOVE SOUTHEAST OVERNIGHT AND SHOULD BEGIN TO IMPACT THE
NORTHWEST WITH PRECIPITATION CHANCES BETWEEN 09-12Z. BUFR
SOUNDINGS OVER THE NORTHWEST SHOW LOWER LAYERS THICKENING TOWARD
MORNING WITH SOME LIFT INCREASING TOWARD 12Z. WILL MAINTAIN LIGHT
FREEZING DRIZZLE ACROSS THE NORTHWEST TRANSITIONING TO A CHANCE
FOR LIGHT FREEZING DRIZZLE OR LIGHT FREEZING RAIN/ICE PELLET MIX
BY 12Z. INITIALLY THERE IS NOT MUCH IN THE WAY OF ICE INTRODUCTION
WHICH WOULD FAVOR SOME LIGHT FREEZING DRIZZLE. TEMPERATURES
TONIGHT ARE CHALLENGING AS WELL. GUIDANCE DROPS VALUES INTO THE
TEENS NORTH TO LOWER TO MID 20S MOST AREAS. LAST NIGHT MOIST
BOUNDARY LAYER AND CLOUD COVER KEPT MINS IN THE LOWER 30S. THOUGH
NOT EXPECTING IT TO BE THAT WARM TONIGHT THERE SHOULD BE A DECENT
GRADIENT FROM EAST TO SOUTHWEST WITH UPPER TEENS EAST TO THE MID
TO UPPER 20S OVER THE SOUTHWEST WHERE CLOUDS WILL HOLD.
.LONG TERM /TUESDAY THROUGH MONDAY/...
ISSUED AT 328 PM CST MON FEB 9 2015
LITTLE HAS CHANGED IN OVERALL FORECAST THINKING FROM PREVIOUS
SHIFTS. A LOW PRESSURE SYSTEM WILL SPREAD PRECIPITATION ACROSS
MOST OF MINNESOTA ON TUESDAY...WITH LIGHT PRECIPITATION AFFECTING
NORTHERN IOWA...THEN PUSH A PRETTY STRONG COLD FRONT ACROSS IOWA
ON TUESDAY NIGHT AND WEDNESDAY MORNING. THE PRECIPITATION ACROSS
NORTHERN IOWA STILL LOOKS SPOTTY AND VERY LIGHT...WITH FORECAST
SOUNDINGS SHOWING CLOUD DEPTHS WAVERING BETWEEN ABOUT 3000 AND
8000 FEET AND MAINLY LOCATED BENEATH BOTH THE ICE INTRODUCTION
LAYER AND THE LIMITED FORCING ASSOCIATED WITH THE LOW PASSING BY
TO THE NORTH. THIS SUPPORTS MOSTLY A DRIZZLE/LIGHT RAIN SCENARIO
WITH TEMPERATURES NEAR OR A LITTLE BELOW FREEZING...LIKELY LEADING
TO SOME LIGHT ICE ACCUMULATIONS OF PERHAPS A FEW HUNDREDTHS OF AN
INCH. GIVEN THE RELATIVELY LOW CONFIDENCE IN ACCUMULATING
PRECIPITATION OCCURRING IN OUR AREA...WITH ONLY 40 TO 50 POPS IN
THE NORTH AND VERY LIGHT EXPECTED AMOUNTS...HAVE NOT ISSUED AN
ADVISORY AT THIS TIME. HOWEVER...THIS WILL BE CLOSELY MONITORED
TONIGHT AND TOMORROW AND ONE MAY YET BECOME WARRANTED IF THERE IS
A MORE CONSISTENT SIGNAL FOR MEANINGFUL ICE ACCUMULATION/IMPACTS.
THE LIGHT PRECIPITATION ACROSS THE NORTH WILL END ON TUESDAY
NIGHT...THEN THE AFOREMENTIONED COLD FRONT WILL SWEEP RAPIDLY
SOUTHEASTWARD ACROSS THE AREA. WINDS WILL SURGE SIGNIFICANTLY ON
WEDNESDAY MORNING...THEN AGAIN ON WEDNESDAY EVENING AS ONE LAST
500 MB IMPULSE ROUNDS THE TROUGH AND IS REFLECTED BY A TIGHTENING
SURFACE PRESSURE GRADIENT. FORECAST SOUNDINGS INDICATE WINDS AT
THE TOP OF THE MIXED LAYER APPROACHING 40 KNOTS AT TIMES AND THERE
IS AN INCREASING POSSIBILITY...ESPECIALLY GIVEN THE COLD AIR
ADVECTION AND EFFICIENT MIXING EXPECTED...THAT A WIND ADVISORY MAY
BECOME NECESSARY AT SOME POINT FOR WEDNESDAY INTO WEDNESDAY NIGHT.
TEMPERATURES WILL LIKELY REMAIN STEADY OR FALL DURING THE DAY
WEDNESDAY...THEN PLUMMET FURTHER WEDNESDAY NIGHT WITH WIND CHILLS
OF AROUND 20 TO 25 BELOW FORECAST ACROSS NORTHERN IOWA BY THURSDAY
MORNING.
AS A SURFACE HIGH PRESSURE AREA CROSSES IOWA ON THURSDAY WINDS
WILL LIGHTEN SUBSTANTIALLY BUT IT WILL REMAIN COLD...THEN WE WILL
CONTINUE THIS SERIES OF ALTERNATING HIGHS AND LOW PRESSURE TROUGHS
THROUGH THE WEEKEND. THIS WILL RESULT IN A MODEST WARM UP ON
FRIDAY...ANOTHER FRONTAL PASSAGE LATE FRIDAY...MORE STRONG WINDS
AROUND FRIDAY NIGHT INTO SATURDAY...MORE COLD ON SATURDAY AND
SATURDAY NIGHT...ETC. IN A REPEAT OF THE PATTERN WE HAVE SEEN FOR
THE LAST SEVERAL DAYS ALREADY. THERE IS SOME INDICATION IN THE
PAST SEVERAL RUNS OF THE ECMWF AND GFS THAT THIS PATTERN COULD
SHIFT A BIT FURTHER SOUTHWARD AROUND MONDAY OR TUESDAY OF NEXT
WEEK AS A BROAD 500 MB TROUGH DIGS A BIT FURTHER DOWN INTO THE
CENTRAL U.S. IF THIS VERIFIES THEN IT WOULD SPREAD THE BULK OF THE
PRECIPITATION FROM THE ASSOCIATED SURFACE SYSTEM MORE ACROSS IOWA
RATHER THAN FURTHER NORTH AS WE HAVE SEEN THUS FAR...HOWEVER AT
THIS RANGE IT IS WAY TOO EARLY TO GET MUCH DETAIL OUT OF WHAT THIS
WOULD MEAN FOR SENSIBLE WEATHER AND PRECIPITATION AMOUNTS ACROSS
CENTRAL IOWA.
&&
.AVIATION...09/18Z
ISSUED AT 1153 AM CST MON FEB 9 2015
MAIN CONCERNS CONTINUE TO BE THE STRATUS DECK AND POTENTIAL FOR
SOME LIGHT FREEZING RAIN EARLY TUESDAY THROUGH 18Z. CURRENT TRENDS
SHOW SOME OCCASIONAL BREAKS IN THE CIGS OVER NORTH CENTRAL IA WITH
SOME EXPANSION SOUTH TOWARD KFOD AND KMCW EXPECTED WITH A FEW
HOURS OF VFR CONDITIONS EXPECTED PRIOR TO 00Z. ELSEWHERE CIGS
BOUNCING BETWEEN MVFR/VFR OR REMAINING MVFR THROUGH 00Z. AFT 00Z
EXPECT BOUNDARY LAYER TO LOWER WITH RETURN OF MVFR CIGS
REGIONWIDE. OVER THE NORTH AT KFOD AND KMCW...SOME POTENTIAL FOR
IFR CONDITIONS TO RETURN AFT 11Z WITH -FZRADZPL POSSIBLE. SOME
UNCERTAINTY ON COVERAGE BUT HAVE CONFINED TO NORTHERN SITES AS
MOST PROBABLE.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...REV
LONG TERM...LEE
AVIATION...REV
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1138 PM CST SUN FEB 8 2015
.UPDATE...
ISSUED AT 617 PM CST SUN FEB 8 2015
UPDATE TO ADD SPRINKLES ACROSS THE SOUTH THROUGH THE EARLY EVENING
HOURS. RECENT HRRR RUNS HAVE THIS PRECIP MODELED WELL. THE WEAK
SHORT WAVE SUPPORTING THE PRECIP WILL EXIT THE AREA BY LATE EVENING.
&&
.SYNOPSIS...
ISSUED AT 316 PM CST SUN FEB 8 2015
INCREASING NORTH TO NORTHEAST WINDS IN THE WAKE OF THE DEPARTING LOW
PRESSURE SYSTEM WAS BEGINNING TO ADVECT A NOTICEABLY COLDER AIRMASS
INTO THE REGION THIS AFTERNOON. AT 2 PM...TEMPERATURES RANGED FROM
AROUND 30 IN THE FAR NORTHEAST TO THE MID 40S...AND POSSIBLY UPPER
40S...OVER FAR NORTHEAST MO. AN UPPER LEVEL SHORTWAVE AND A CHAIN
OF WEAK LOWS ALONG A COLD FRONT AT THE SURFACE WAS OVER THE
SOUTHERN GREAT LAKES AND OHIO RIVER VALLEY RESPECTIVELY. A TROUGH OF LOW
PRESSURE AT THE SURFACE EXTENDED SOUTHWEST INTO TX...WHILE THE
COLD FRONT CURVED BACK W AND NW ACROSS CENTRAL MO INTO NEB AND SW
SD. THIS WAS ALIGNED UNDER THE NW FLOW ALOFT AND BAROCLINIC AXIS
AT 850 MB...WHICH WAS TIGHTEST ALONG THE CANADIAN BORDER. VERY
MILD TEMPERATURES AT 850 MB REMAINED OVER MUCH OF THE CENTRAL AND
SOUTHERN PLAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 316 PM CST SUN FEB 8 2015
THE MAIN CHALLENGE IS TRENDS WITH TEMPERATURES AND CLOUDS AS COLD
AIR ADVECTION CONTINUES IN THE WAKE OF THE SYSTEM MOVING THROUGH THE
OHIO RIVER VALLEY. SATELLITE IMAGERY AND SURFACE OBSERVATIONS SHOWED
AN EXTENSIVE AREA OF STRATUS NORTHEAST OF STALLED BOUNDARY BISECTING
THE NORTHERN PLAINS...ENCOMPASSING ALL OF MN...WI...AND THE GREAT
LAKES. IN THE LOCAL AREA...THE LOW CLOUDS HAVE ADVANCED TO ROUGHLY
ALONG AND EAST OF A LINE FROM INDEPENDENCE THROUGH MUSCATINE TO
GALESBURG. THIS SHOULD OVERSPREAD THE ENTIRE FORECAST AREA BY THIS
EVENING AND REMAIN IN PLACE OVERNIGHT WITH THE BACK EDGE OVER LAKE
SUPERIOR POSSIBLY REACHING NORTHERN IL TOWARD SUNRISE AT THE CURRENT
RATE. A DEEP LOW LEVEL COLD ADVECTION FLOW WILL ADVECT AN AIRMASS
WITH TEMPERATURES CURRENTLY IN THE LOWER 20S AND EVEN A FEW TEENS
OVER WI INTO THE FORECAST AREA OVERNIGHT. THUS...EVEN WITH OVERCAST
CONDITIONS...A BLEND OF GUIDANCE TEMPERATURES RANGING FROM AROUND 15
NORTH TO THE MID 20S SOUTH LOOKED REASONABLE. THE INCREASINGLY DRIER
AIRMASS SHOULD GRADUALLY ELIMINATE THE LIGHT FOG AND HAZE THAT
WAS REDUCING VISIBILITIES TO 3 MILES OR LESS OVER MUCH OF THE
AREA.
MONDAY...THE BIG QUESTION WILL BE HOW LONG IT WILL TAKE FOR THE
LOW CLOUDS TO CLEAR OUT UNDER THE INCREASING MID LEVEL SUBSIDENCE
AND HIGH PRESSURE MOVING IN AT THE SURFACE. FOR NOW...HAVE GONE WITH
A BROAD-BRUSHED...GRADUAL CLEARING TREND WITH AT LEAST PARTLY SUNNY
SKIES BY AFTERNOON. LIMITED SUNSHINE AND SHALLOW MIXING INTO THE
CONTINUED LOW LEVEL NORTHERLY FLOW SHOULD RESULT IN A COMPARATIVELY
COLDER DAY WITH HIGHS FROM ONLY THE MID 20S NORTH TO MID 30S IN
THE FAR SOUTH...CLOSEST TO THE EDGE OF THE SNOWFIELD.
.LONG TERM...(MONDAY NIGHT THROUGH NEXT SUNDAY)
ISSUED AT 316 PM CST SUN FEB 8 2015
QUIET CONDITIONS WILL BE SEEN ACROSS THE AREA MONDAY NIGHT AS TWO
STORM SYSTEMS MOVE OUT OF THE ROCKIES. TEMPERATURES WILL AVERAGE
BELOW NORMAL.
TUESDAY THROUGH WEDNESDAY THE WEAK STORM SYSTEMS WILL PASS MAINLY
NORTH OF THE AREA. MOISTURE IS LIMITED AND THE BETTER FORCING IS
ACROSS MINNESOTA INTO WISCONSIN.
AREAS ALONG/SOUTH OF I-80 SHOULD REMAIN DRY TUESDAY THOUGH WEDNESDAY
WITH TEMPERATURES SLIGHTLY ABOVE NORMAL.
AREAS ALONG/NORTH OF HIGHWAY 30 MAY SEE SOME VERY LIGHT
PRECIPITATION. THERMAL PROFILES SUPPORT THE POTENTIAL OF SOME VERY
LIGHT SNOW WITH POSSIBLY A LITTLE SLEET MIXED IN WITH IT. THE BETTER
CHANCES FOR ANY SNOW/SLEET WILL BE NORTH OF HIGHWAY 20.
AS FOR AMOUNTS...A DUSTING OF ACCUMULATION MAY BE POSSIBLE IN THE
HIGHWAY 20 CORRIDOR.
WEDNESDAY NIGHT ON...
THE MODEL CONSENSUS HAS QUIET CONDITIONS WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT AS HIGH PRESSURE MOVES THROUGH THE MIDWEST.
TEMPERATURES WILL AVERAGE WELL BELOW NORMAL.
ON FRIDAY A STORM SYSTEM MOVES FROM MINNESOTA INTO WISCONSIN.
MOISTURE IS LIMITED AND THE OVERALL FORCING IS NOT GREAT. THUS MOST
OF THE FORCING SHOULD GO INTO CLOUD DEVELOPMENT AS THE ASSOCIATED
FRONT MOVES THROUGH THE AREA. NONETHELESS...THE MODEL CONSENSUS DOES
HAVE SLIGHT CHANCE POPS OVER ROUGHLY THE NORTHERN HALF OF THE AREA
WHEN THE STRONGEST FORCING/MOISTURE ARE PRESENT.
FRIDAY NIGHT THROUGH SATURDAY NIGHT QUIET CONDITIONS ARE AGAIN
EXPECTED AS ANOTHER HIGH PRESSURE MOVES THROUGH THE MIDWEST.
TEMPERATURES WILL AVERAGE BELOW NORMAL.
ON SUNDAY THE MODEL CONSENSUS HAS SLIGHT CHANCE POPS FOR MUCH OF THE
AREA AS A WEAK DISTURBANCE DROPS SOUTHEAST FROM THE CANADIAN PLAINS.
LIKE THE FRIDAY SYSTEM...MOISTURE WILL BE LIMITED. TEMPERATURES
SHOULD CONTINUE TO AVERAGE BELOW NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1132 PM CST SUN FEB 8 2015
DRY NORTHEAST FLOW IS RESULTING IN GENERALLY IMPROVING
VISIBILITIES LATE THIS EVENING...WITH THIS TREND EXPECTED TO
CONTINUE AT KCID/KBRL. OTHERWISE...EXPECT MAINLY MVFR STRATUS
OVERNIGHT INTO MONDAY MORNING. LOW CONFIDENCE IN TIMING OF THE
DECK SCATTERING OUT AROUND 21Z MONDAY AFTERNOON.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...RP KINNEY
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...08
AVIATION...RP KINNEY
AREA FORECAST DISCUSSION
NWS TOPEKA KS
344 PM CST Mon Feb 9 2015
.SHORT TERM...(This Evening through Tuesday)
Issued at 343 PM CST MON FEB 9 2015
Surface high pressure ridge extends southeast across eastern Kansas
from Minnesota. Cool east to northeast flow along with stratus which
has held on most of the day, has kept temperatures from rising much
from morning lows especially across north central Kansas.
Latest visible satellite loop shows the stratus breaking up from
central Missouri into east central Kansas. HRRR, NAM and RAP show
some semblance of this trend for partial clearing from Emporia to
Topeka along with some further clearing this evening into northeast
Kansas. Areas of north central Kansas look to stay in the stratus
tonight. The low clouds may reform later tonight across the east.
Areas of fog are likely for much of the area overnight. Lows tonight
will vary due to breaks in the clouds. Expecting lows in the upper
20s to low to mid 30s.
Thermal axis noses into northeast Kansas on Tuesday ahead of the
next shortwave and surface frontal boundary. Forecast soundings show
mixing to 925mb to 900mb in the afternoon. Stratus looks to break up
in the late morning and early afternoon hours. Highs will range from
the 50s to around 60.
.LONG TERM...(Tuesday Night through Monday)
Issued at 343 PM CST MON FEB 9 2015
Next cold front still on track to move through the county warning
area (cwa) Tuesday night as a weak shortwave trough extending from
the Great Lakes into the southwest CONUS moves through and shears
with time. The initial push of cooler air will lower highs into the
upper 30s and lower 40s for Wednesdays and should move through the
area dry as well.
As the stronger secondary d cold front moves through late
Wednesday/Wednesday night...a much colder push of air will
overspread the area. The GFS is deeper with the eastern trough and
colder than the EC. Following lows in the teens and lower 20s
Thursday morning...highs will struggle to reach the 20s and lower
30s most areas. Again...with only weak forcing and limited
moisture...will maintain a dry fcst.
The upper ridging along the west coast will amplify and edge
eastward by Friday with warmer air temporarily advecting into the
cwa with highs into the 40s east and the low to mid 50s west. Models
are in agreement with the next strong northwest flow wave into the
eastern CONUS trough which will drive another push colder air back
into the cwa with highs mainly in the 30s Saturday...then the low to
mid 40s Sunday.
Even warmer air will then overspread the area on Monday with highs
mainly in the low to middle 50s as another longer wave trough
approaches the central plains. There will be a chance for rain
across the southeast cwa during the day...then a chance for rain or
snow that night as the cold front moves through.
&&
.AVIATION...(For the 18Z TAFs through 18Z Tuesday Afternoon)
Issued at 1156 AM CST MON FEB 9 2015
Expect conditions at the terminals to improve a bit this afternoon
to the MVFR range. The stratus should persist though and the
possibility of dipping back into the IFR category tonight will
likely play out. Late in the TAF period we should see more a more
stable trend in the improvement of conditions to the MVFR then
eventually VFR as the stratus recedes north of the terminals and a
weak ridge pushes through the region.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...53
LONG TERM...63
AVIATION...Drake
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1203 PM CST Mon Feb 9 2015
.UPDATE...
Issued at 852 AM CST MON FEB 9 2015
Extended dense fog advisory until 11 am for Republic, Cloud and
Ottawa Counties as visibilities continue to be around 1/4 mile.
Expect gradual improvement over the next couple of hours.
&&
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 156 AM CST MON FEB 9 2015
Backdoor cold front has pushed southwest through the forecast
area overnight as another weak wave tracked into the mid MS
valley. Behind the front cold air advection has caused fog and
stratus as a weak surface ridge slides through NE and into KS
later today. The lowest visibilities are currently located on the
western edge of the fog/stratus over south central NE. Winds
should decrease as the ridge approaches the forecast area limiting
the amount of mixing as most sites are only a few degrees away
from saturation. Several runs of the SREF and HRRR show that dense
fog may try to build into north central KS this morning therefore
have kept the mention of fog in the forecast. Not confident if the
visibilities will warrant an advisory at this point and or when
they will improve. It appears that eastern KS will only experience
minor visibility restrictions through mid morning hours. The more
solid fog in north central KS may try to hold on until late
morning, but should lift into a stratus deck by noon. Stratus and
or fog should push over the entire area within the next few hours
although the question is how long it sticks around today. As of
now most of the guidance is suggesting clouds last most of the
daytime hours, but may begin to scatter out on the southern edge.
Regardless have lowered the high temperatures today due to the
uncertainty of the cloud cover, which should roughly range from 40
in far northeast KS to 50 in central KS. By tonight the surface
high retreats eastward allowing return flow. The better chances
for stratus tonight will push slightly westward into central KS
and central NE ahead of the next shortwave forecast to track over
the northern plains.
.LONG TERM...(Tuesday through Sunday)
Issued at 156 AM CST MON FEB 9 2015
Another above normal day is on track for Tuesday, as area remains
between systems and under warm nose aloft. Highs forecast to mix
from the lower 50s northeast to near 60 in the west. GFS is faster
with the arrival of the front and has it through much of the area
by sunrise while NAM remains slower, bisecting the CWA by sunrise.
Think a well mixed boundary layer will keep overnight lows up in
the 30s, and may rise in the morning if frontal boundary is
slower, but otherwise expect steady to falling temperatures on
Wednesday afternoon. Highs in the lower 40s may occur early. Lows
fall quickly into the teens as the cold high moves due south into
the Central Plains. Cold advection slowly moderates and shifts
east into Thursday but highs only around 20 in the northeast to
lower 30s in the southern counties.
Large scale longwave trof setting up over the Eastern half of the
US is persistent in sending rounds of cold air nearly due
southward out of central Canada into the Plains for late week into
the weekend. Friday still a transition day between cold surges and
brings a rebound back into the 40s to near 50 for high
temperatures before more cold air comes southward for Saturday.
Trend for the eastern trof is deeper and farther south and west,
however it does appear to progress to the east later in the
weekend as the upper jet rounds the base of the trof and next
shortwave across Canada aids in an easterly trend. Temperatures in
the 30s to low 40s could be generous for Saturday, as may be the
forecast lows in the upper teens, but could start to see
moderating influences by Sunday. Kept a near normal temperature
forecast in the upper 30s to lower 40s for Sunday.
&&
.AVIATION...(For the 18Z TAFs through 18Z Tuesday Afternoon)
Issued at 1156 AM CST MON FEB 9 2015
Expect conditions at the terminals to improve a bit this afternoon
to the MVFR range. The stratus should persist though and the
possibility of dipping back into the IFR category tonight will
likely play out. Late in the TAF period we should see more a more
stable trend in the improvement of conditions to the MVFR then
eventually VFR as the stratus recedes north of the terminals and a
weak ridge pushes through the region.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...53
SHORT TERM...Sanders
LONG TERM...67
AVIATION...Drake
AREA FORECAST DISCUSSION
NWS WICHITA KS
1040 AM CST MON FEB 9 2015
.UPDATE...
ISSUED AT 1039 AM CST MON FEB 9 2015
BACKDOOR COLD FRONT CONTINUES TO PUSH SOUTHWEST ACROSS THE FORECAST
AREA...WITH A VERY LOW STRATUS AND FOG DECK IN ITS WAKE. HAVE
ALREADY UPDATED THE GRID/ZONES TO EXTEND THE DENSE FOG ADVISORY FOR
CENTRAL KS UNTIL NOON...AS LATEST HI-RES SHORT TERM MODELS KEEP
BOUNDARY LAYER RH VALUES VERY HIGH ACROSS MOST OF CENTRAL KS UNTIL
AROUND NOON BEFORE IT STARTS TO BURN OFF. SO NOON EXPIRATION OF THE
DENSE FOG ADVISORY SHOULD BE OKAY. STAY TUNED.
THIS LOW CLOUD DECK AND NE FLOW WILL CERTAINLY THROW WRENCH IN THE
MAX TEMP FORECAST FOR TODAY. SOME AREAS OF CENTRAL KS WILL STAY IN
THE CLOUDS/FOG AT LEAST UNTIL NOON...WHICH MAY DRASTICALLY CUT INTO
FORECAST MAX TEMPS TODAY. SO WILL ADJUST THE MAX TEMP DOWN
ACCORDINGLY. EXPECT SOME AREAS NORTH AND NORTHEAST OF WICHITA TO
STRUGGLE TO MAKE THE LOW 50S.
KETCHAM
UPDATE ISSUED AT 903 AM CST MON FEB 9 2015
GONNA SEND OUT A QUICK UPDATE AND EXTEND THE DENSE FOG ADVISORY
UNTIL NOON. BACKDOOR COLD FRONT CONTINUES TO PUSH SOUTH...WITH NE
SECTIONS OF WICHITA METRO NOW BEGINNING TO HAVE REDUCED
VISIBILITIES. HI-RES SHORT TERM MODELS DO NOT COMPLETELY BURN OFF
THE FOG UNTIL AROUND NOON...AS COOLER AIR FROM THE NORTHEAST RUNS
INTO HIGHER SURFACE DEWPOINT AIR. SO THINK FOG/STRATUS WILL BE
STUBBORN TO BURN OFF...ESPECIALLY IN CENTRAL KS.
KETCHAM
UPDATE ISSUED AT 741 AM CST MON FEB 9 2015
DENSE FOG IS ADVANCING FURTHER SOUTH THAN ORIGINALLY
THOUGHT...HAVE EXPANDED THE DENSE FOG ADVISORY ACROSS ALL OF
CENTRAL AND PORTIONS OF SOUTH CENTRAL KANSAS. VISIBILITY ALONG THE
LEADING EDGE OF THE STRATUS IS REPORTED TO BE LESS THAN 1/4 MILE.
BILLINGS WRIGHT
UPDATE ISSUED AT 654 AM CST MON FEB 9 2015
WITH LOW VISIBILITIES ALONG AND BEHIND THE LEADING EDGE OF THE
STRATUS...HAVE ISSUED A DENSE FOG ADVISORY FOR A PORTION OF
CENTRAL KANSAS THROUGH 15Z. VISIBILITIES MAY LIFT SOME AFTER
INITIAL DROP ALONG THE LEADING EDGE...BUT FEEL EVEN PATCHY DENSE
FOG MAY CAUSE PROBLEMS FOR TRAVELERS ALONG I-70.
BILLINGS WRIGHT
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 348 AM CST MON FEB 9 2015
TODAY-TONIGHT:
BACKDOOR COLD FRONT WILL CONTINUE TO PUSH ACROSS THE AREA...WITH
LOW CLOUDS GRADUALLY SPREADING INTO AT LEAST THE NE HALF OF THE
FORECAST AREA. APPEARS THAT FRONT WILL SAG A BIT FURTHER SOUTH/
WEST THAN PREVIOUS ANTICIPATED. SOME CONCERN FOR TRANSIENT DENSE
FOG ALONG LEADING EDGE OF COLDER AIR...WITH 1-4 MILE VISIBILITY
FOG FURTHER INTO THE POST FRONTAL AIRMASS. BEST SETUP FOR DENSE
FOG APPEARS TO BE JUST NORTH OF FORECAST AREA. SURFACE RIDGE WILL
QUICKLY OVERSPREAD THE AREA DURING THE DAY AND WEAK RETURN FLOW
DEVELOPS TONIGHT. THIS WILL MAKE LOWS A BIT TRICKY AS WELL.
TUE-WED:
WEAK RETURN FLOW CONTINUE ON TUE WITH SLIGHT REBOUND IN
TEMPERATURES IN THE NE HALF OF FORECAST AREA. THE NEXT SURGE OF
COLDER AIR WILL ARRIVE TUE NIGHT...WITH COLD AIR ADVECTION
INCREASING DURING THE DAY WED. TEMPERATURES WILL LIKELY
ROLLER COASTER DURING THE DAY AS COLD AIR ADVECTION AND
INSOLATION VARY. PRECIPITATION CHANCES WITH FRONT LOOK TO BE QUITE
LOW GIVEN RELATIVELY DRY LOW LEVEL AIR. -HOWERTON
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 348 AM CST MON FEB 9 2015
GFS/ECMWF IN FAIRLY GOOD AGREEMENT WITH RIDGE BUILDING IN THE
WESTERN US AND TROUGHING IN THE EAST. BOTH SHOW A LARGE SURFACE
HIGH OVERSPREADING THE CENTRAL US...SENDING MUCH COOLER AIR INTO
THE AREA ON SAT...WHICH WILL PERSIST INTO SUN. ALWAYS A TOUGH
CALL...DESPITE MODEL AGREEMENT...AS SLIGHTLY MORE ZONAL UPPER
FLOW COULD SHUNT COLDEST AIR EAST OF THE AREA. HOWEVER THERE WAS
SUFFICIENT AGREEMENT BETWEEN MODELS AND SURROUNDING OFFICES TO
HEDGE COOLER THAN GUIDANCE AT THIS POINT. -HOWERTON
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 559 AM CST MON FEB 9 2015
CHALLENGING MORNING FOR AVIATION WITH MVFR TO IFR AND POSSIBLY
SOME LIFR CEILINGS/VISIBILITY MOVING IN WITH THE BACKDOOR FRONT
FROM THE NORTHWEST. THE RR AND HRRR HAVE DONE WELL WITH THE
PROGRESSION OF THE LOW CLOUDS OVER THE PAST FEW HOURS AND REALLY
FOCUSED ON IT FOR THE FIRST PART OF THE FORECAST. FEEL KRSL/KSLN
WILL FEEL THE BRUNT OF THE WORST CONDITIONS WITH KHUT/KICT AND
KCNU HAVING SOME MODERATE MVFR IMPACTS. THE LOWEST
CEILINGS/VISIBILITY WITH IFR TO LIFR CRITERIA ARE EXPECTED ALONG
THE WESTWARD MOVING ADVANCEMENT OF THE STRATUS WHICH WILL IMPACT
KRSL/KSLN THIS MORNING. THIS PROGRESSION WILL STOP BY MID MORNING
AND LOW CLOUDS WILL ERODE BY AFTERNOON WITH VFR CONDITIONS
EXPECTED TO RETURN. NORTHERLY WINDS WILL BECOME EASTERLY AND
EVENTUALLY SOUTHEASTERLY DURING THE DAY AND THROUGHOUT THE
OVERNIGHT HOURS.
BILLINGS WRIGHT
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 56 35 61 41 / 0 0 0 0
HUTCHINSON 57 35 60 40 / 0 0 0 0
NEWTON 53 34 59 39 / 0 0 0 0
ELDORADO 53 34 61 40 / 0 0 0 0
WINFIELD-KWLD 59 36 63 42 / 0 0 0 0
RUSSELL 60 36 60 39 / 0 0 0 0
GREAT BEND 62 36 60 39 / 0 0 0 0
SALINA 51 33 59 38 / 0 0 0 0
MCPHERSON 54 34 59 39 / 0 0 0 0
COFFEYVILLE 53 32 61 42 / 0 0 0 0
CHANUTE 49 31 60 40 / 0 0 0 0
IOLA 48 31 59 39 / 0 0 0 0
PARSONS-KPPF 51 32 61 42 / 0 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR KSZ032-033-047>052-
067>069-083.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
903 AM CST MON FEB 9 2015
.UPDATE...
ISSUED AT 903 AM CST MON FEB 9 2015
GONNA SEND OUT A QUICK UPDATE AND EXTEND THE DENSE FOG ADVISORY
UNTIL NOON. BACKDOOR COLD FRONT CONTINUES TO PUSH SOUTH...WITH NE
SECTIONS OF WICHITA METRO NOW BEGINNING TO HAVE REDUCED
VISIBILITIES. HI-RES SHORT TERM MODELS DO NOT COMPLETELY BURN OFF
THE FOG UNTIL AROUND NOON...AS COOLER AIR FROM THE NORTHEAST RUNS
INTO HIGHER SURFACE DEWPOINT AIR. SO THINK FOG/STRATUS WILL BE
STUBBORN TO BURN OFF...ESPECIALLY IN CENTRAL KS.
KETCHAM
UPDATE ISSUED AT 741 AM CST MON FEB 9 2015
DENSE FOG IS ADVANCING FURTHER SOUTH THAN ORIGINALLY
THOUGHT...HAVE EXPANDED THE DENSE FOG ADVISORY ACROSS ALL OF
CENTRAL AND PORTIONS OF SOUTH CENTRAL KANSAS. VISIBILITY ALONG THE
LEADING EDGE OF THE STRATUS IS REPORTED TO BE LESS THAN 1/4 MILE.
BILLINGS WRIGHT
UPDATE ISSUED AT 654 AM CST MON FEB 9 2015
WITH LOW VISIBILITIES ALONG AND BEHIND THE LEADING EDGE OF THE
STRATUS...HAVE ISSUED A DENSE FOG ADVISORY FOR A PORTION OF
CENTRAL KANSAS THROUGH 15Z. VISIBILITIES MAY LIFT SOME AFTER
INITIAL DROP ALONG THE LEADING EDGE...BUT FEEL EVEN PATCHY DENSE
FOG MAY CAUSE PROBLEMS FOR TRAVELERS ALONG I-70.
BILLINGS WRIGHT
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 348 AM CST MON FEB 9 2015
TODAY-TONIGHT:
BACKDOOR COLD FRONT WILL CONTINUE TO PUSH ACROSS THE AREA...WITH
LOW CLOUDS GRADUALLY SPREADING INTO AT LEAST THE NE HALF OF THE
FORECAST AREA. APPEARS THAT FRONT WILL SAG A BIT FURTHER SOUTH/
WEST THAN PREVIOUS ANTICIPATED. SOME CONCERN FOR TRANSIENT DENSE
FOG ALONG LEADING EDGE OF COLDER AIR...WITH 1-4 MILE VISIBILITY
FOG FURTHER INTO THE POST FRONTAL AIRMASS. BEST SETUP FOR DENSE
FOG APPEARS TO BE JUST NORTH OF FORECAST AREA. SURFACE RIDGE WILL
QUICKLY OVERSPREAD THE AREA DURING THE DAY AND WEAK RETURN FLOW
DEVELOPS TONIGHT. THIS WILL MAKE LOWS A BIT TRICKY AS WELL.
TUE-WED:
WEAK RETURN FLOW CONTINUE ON TUE WITH SLIGHT REBOUND IN
TEMPERATURES IN THE NE HALF OF FORECAST AREA. THE NEXT SURGE OF
COLDER AIR WILL ARRIVE TUE NIGHT...WITH COLD AIR ADVECTION
INCREASING DURING THE DAY WED. TEMPERATURES WILL LIKELY
ROLLER COASTER DURING THE DAY AS COLD AIR ADVECTION AND
INSOLATION VARY. PRECIPITATION CHANCES WITH FRONT LOOK TO BE QUITE
LOW GIVEN RELATIVELY DRY LOW LEVEL AIR. -HOWERTON
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 348 AM CST MON FEB 9 2015
GFS/ECMWF IN FAIRLY GOOD AGREEMENT WITH RIDGE BUILDING IN THE
WESTERN US AND TROUGHING IN THE EAST. BOTH SHOW A LARGE SURFACE
HIGH OVERSPREADING THE CENTRAL US...SENDING MUCH COOLER AIR INTO
THE AREA ON SAT...WHICH WILL PERSIST INTO SUN. ALWAYS A TOUGH
CALL...DESPITE MODEL AGREEMENT...AS SLIGHTLY MORE ZONAL UPPER
FLOW COULD SHUNT COLDEST AIR EAST OF THE AREA. HOWEVER THERE WAS
SUFFICIENT AGREEMENT BETWEEN MODELS AND SURROUNDING OFFICES TO
HEDGE COOLER THAN GUIDANCE AT THIS POINT. -HOWERTON
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 559 AM CST MON FEB 9 2015
CHALLENGING MORNING FOR AVIATION WITH MVFR TO IFR AND POSSIBLY
SOME LIFR CEILINGS/VISIBILITY MOVING IN WITH THE BACKDOOR FRONT
FROM THE NORTHWEST. THE RR AND HRRR HAVE DONE WELL WITH THE
PROGRESSION OF THE LOW CLOUDS OVER THE PAST FEW HOURS AND REALLY
FOCUSED ON IT FOR THE FIRST PART OF THE FORECAST. FEEL KRSL/KSLN
WILL FEEL THE BRUNT OF THE WORST CONDITIONS WITH KHUT/KICT AND
KCNU HAVING SOME MODERATE MVFR IMPACTS. THE LOWEST
CEILINGS/VISIBILITY WITH IFR TO LIFR CRITERIA ARE EXPECTED ALONG
THE WESTWARD MOVING ADVANCEMENT OF THE STRATUS WHICH WILL IMPACT
KRSL/KSLN THIS MORNING. THIS PROGRESSION WILL STOP BY MID MORNING
AND LOW CLOUDS WILL ERODE BY AFTERNOON WITH VFR CONDITIONS
EXPECTED TO RETURN. NORTHERLY WINDS WILL BECOME EASTERLY AND
EVENTUALLY SOUTHEASTERLY DURING THE DAY AND THROUGHOUT THE
OVERNIGHT HOURS.
BILLINGS WRIGHT
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 57 35 61 41 / 0 0 0 0
HUTCHINSON 58 35 60 40 / 0 0 0 0
NEWTON 54 34 59 39 / 0 0 0 0
ELDORADO 54 34 61 40 / 0 0 0 0
WINFIELD-KWLD 60 36 63 42 / 0 0 0 0
RUSSELL 61 36 60 39 / 0 0 0 0
GREAT BEND 63 36 60 39 / 0 0 0 0
SALINA 52 33 59 38 / 0 0 0 0
MCPHERSON 55 34 59 39 / 0 0 0 0
COFFEYVILLE 54 32 61 42 / 0 0 0 0
CHANUTE 50 31 60 40 / 0 0 0 0
IOLA 49 31 59 39 / 0 0 0 0
PARSONS-KPPF 52 32 61 42 / 0 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR KSZ032-033-047>052-
067>069-083.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
852 AM CST Mon Feb 9 2015
.UPDATE...
Issued at 852 AM CST MON FEB 9 2015
Extended dense fog advisory until 11 am for Republic, Cloud and
Ottawa Counties as visibilities continue to be around 1/4 mile.
Expect gradual improvement over the next couple of hours.
&&
.SHORT TERM...(Today and Tonight)
Issued at 156 AM CST MON FEB 9 2015
Backdoor cold front has pushed southwest through the forecast
area overnight as another weak wave tracked into the mid MS
valley. Behind the front cold air advection has caused fog and
stratus as a weak surface ridge slides through NE and into KS
later today. The lowest visibilities are currently located on the
western edge of the fog/stratus over south central NE. Winds
should decrease as the ridge approaches the forecast area limiting
the amount of mixing as most sites are only a few degrees away
from saturation. Several runs of the SREF and HRRR show that dense
fog may try to build into north central KS this morning therefore
have kept the mention of fog in the forecast. Not confident if the
visibilities will warrant an advisory at this point and or when
they will improve. It appears that eastern KS will only experience
minor visibility restrictions through mid morning hours. The more
solid fog in north central KS may try to hold on until late
morning, but should lift into a stratus deck by noon. Stratus and
or fog should push over the entire area within the next few hours
although the question is how long it sticks around today. As of
now most of the guidance is suggesting clouds last most of the
daytime hours, but may begin to scatter out on the southern edge.
Regardless have lowered the high temperatures today due to the
uncertainty of the cloud cover, which should roughly range from 40
in far northeast KS to 50 in central KS. By tonight the surface
high retreats eastward allowing return flow. The better chances
for stratus tonight will push slightly westward into central KS
and central NE ahead of the next shortwave forecast to track over
the northern plains.
.LONG TERM...(Tuesday through Sunday)
Issued at 156 AM CST MON FEB 9 2015
Another above normal day is on track for Tuesday, as area remains
between systems and under warm nose aloft. Highs forecast to mix
from the lower 50s northeast to near 60 in the west. GFS is faster
with the arrival of the front and has it through much of the area
by sunrise while NAM remains slower, bisecting the CWA by sunrise.
Think a well mixed boundary layer will keep overnight lows up in
the 30s, and may rise in the morning if frontal boundary is
slower, but otherwise expect steady to falling temperatures on
Wednesday afternoon. Highs in the lower 40s may occur early. Lows
fall quickly into the teens as the cold high moves due south into
the Central Plains. Cold advection slowly moderates and shifts
east into Thursday but highs only around 20 in the northeast to
lower 30s in the southern counties.
Large scale longwave trof setting up over the Eastern half of the
US is persistent in sending rounds of cold air nearly due
southward out of central Canada into the Plains for late week into
the weekend. Friday still a transition day between cold surges and
brings a rebound back into the 40s to near 50 for high
temperatures before more cold air comes southward for Saturday.
Trend for the eastern trof is deeper and farther south and west,
however it does appear to progress to the east later in the
weekend as the upper jet rounds the base of the trof and next
shortwave across Canada aids in an easterly trend. Temperatures in
the 30s to low 40s could be generous for Saturday, as may be the
forecast lows in the upper teens, but could start to see
moderating influences by Sunday. Kept a near normal temperature
forecast in the upper 30s to lower 40s for Sunday.
&&
.AVIATION...(For the 12Z TAFs through 12Z Tuesday Morning)
Issued at 521 AM CST MON FEB 9 2015
MVFR/IFR conditions will continue through the afternoon hours.
Visibilities are expected to improve later this morning. The main
uncertainty will be the timing of when the stratus scatters out.
For now have gone with conditions improving around 19-20Z although
the clouds edge could set up near the taf sites. There is a chance
visibilities could decrease to MVFR early tomorrow morning.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY until 11 AM CST this morning FOR
KSZ008-020-034.
&&
$$
UPDATE...53
SHORT TERM...Sanders
LONG TERM...67
AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS WICHITA KS
741 AM CST MON FEB 9 2015
.UPDATE...
ISSUED AT 741 AM CST MON FEB 9 2015
DENSE FOG IS ADVANCING FURTHER SOUTH THAN ORIGINALLY
THOUGHT...HAVE EXPANDED THE DENSE FOG ADVISORY ACROSS ALL OF
CENTRAL AND PORTIONS OF SOUTH CENTRAL KANSAS. VISIBILITY ALONG THE
LEADING EDGE OF THE STRATUS IS REPORTED TO BE LESS THAN 1/4 MILE.
BILLINGS WRIGHT
UPDATE ISSUED AT 654 AM CST MON FEB 9 2015
WITH LOW VISIBILITIES ALONG AND BEHIND THE LEADING EDGE OF THE
STRATUS...HAVE ISSUED A DENSE FOG ADVISORY FOR A PORTION OF
CENTRAL KANSAS THROUGH 15Z. VISIBILITIES MAY LIFT SOME AFTER
INITIAL DROP ALONG THE LEADING EDGE...BUT FEEL EVEN PATCHY DENSE
FOG MAY CAUSE PROBLEMS FOR TRAVELERS ALONG I-70.
BILLINGS WRIGHT
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 348 AM CST MON FEB 9 2015
TODAY-TONIGHT:
BACKDOOR COLD FRONT WILL CONTINUE TO PUSH ACROSS THE AREA...WITH
LOW CLOUDS GRADUALLY SPREADING INTO AT LEAST THE NE HALF OF THE
FORECAST AREA. APPEARS THAT FRONT WILL SAG A BIT FURTHER SOUTH/
WEST THAN PREVIOUS ANTICIPATED. SOME CONCERN FOR TRANSIENT DENSE
FOG ALONG LEADING EDGE OF COLDER AIR...WITH 1-4 MILE VISIBILITY
FOG FURTHER INTO THE POST FRONTAL AIRMASS. BEST SETUP FOR DENSE
FOG APPEARS TO BE JUST NORTH OF FORECAST AREA. SURFACE RIDGE WILL
QUICKLY OVERSPREAD THE AREA DURING THE DAY AND WEAK RETURN FLOW
DEVELOPS TONIGHT. THIS WILL MAKE LOWS A BIT TRICKY AS WELL.
TUE-WED:
WEAK RETURN FLOW CONTINUE ON TUE WITH SLIGHT REBOUND IN
TEMPERATURES IN THE NE HALF OF FORECAST AREA. THE NEXT SURGE OF
COLDER AIR WILL ARRIVE TUE NIGHT...WITH COLD AIR ADVECTION
INCREASING DURING THE DAY WED. TEMPERATURES WILL LIKELY
ROLLER COASTER DURING THE DAY AS COLD AIR ADVECTION AND
INSOLATION VARY. PRECIPITATION CHANCES WITH FRONT LOOK TO BE QUITE
LOW GIVEN RELATIVELY DRY LOW LEVEL AIR. -HOWERTON
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 348 AM CST MON FEB 9 2015
GFS/ECMWF IN FAIRLY GOOD AGREEMENT WITH RIDGE BUILDING IN THE
WESTERN US AND TROUGHING IN THE EAST. BOTH SHOW A LARGE SURFACE
HIGH OVERSPREADING THE CENTRAL US...SENDING MUCH COOLER AIR INTO
THE AREA ON SAT...WHICH WILL PERSIST INTO SUN. ALWAYS A TOUGH
CALL...DESPITE MODEL AGREEMENT...AS SLIGHTLY MORE ZONAL UPPER
FLOW COULD SHUNT COLDEST AIR EAST OF THE AREA. HOWEVER THERE WAS
SUFFICIENT AGREEMENT BETWEEN MODELS AND SURROUNDING OFFICES TO
HEDGE COOLER THAN GUIDANCE AT THIS POINT. -HOWERTON
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 559 AM CST MON FEB 9 2015
CHALLENGING MORNING FOR AVIATION WITH MVFR TO IFR AND POSSIBLY
SOME LIFR CEILINGS/VISIBILITY MOVING IN WITH THE BACKDOOR FRONT
FROM THE NORTHWEST. THE RR AND HRRR HAVE DONE WELL WITH THE
PROGRESSION OF THE LOW CLOUDS OVER THE PAST FEW HOURS AND REALLY
FOCUSED ON IT FOR THE FIRST PART OF THE FORECAST. FEEL KRSL/KSLN
WILL FEEL THE BRUNT OF THE WORST CONDITIONS WITH KHUT/KICT AND
KCNU HAVING SOME MODERATE MVFR IMPACTS. THE LOWEST
CEILINGS/VISIBILITY WITH IFR TO LIFR CRITERIA ARE EXPECTED ALONG
THE WESTWARD MOVING ADVANCEMENT OF THE STRATUS WHICH WILL IMPACT
KRSL/KSLN THIS MORNING. THIS PROGRESSION WILL STOP BY MID MORNING
AND LOW CLOUDS WILL ERODE BY AFTERNOON WITH VFR CONDITIONS
EXPECTED TO RETURN. NORTHERLY WINDS WILL BECOME EASTERLY AND
EVENTUALLY SOUTHEASTERLY DURING THE DAY AND THROUGHOUT THE
OVERNIGHT HOURS.
BILLINGS WRIGHT
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 57 35 61 41 / 0 0 0 0
HUTCHINSON 58 35 60 40 / 0 0 0 0
NEWTON 54 34 59 39 / 0 0 0 0
ELDORADO 54 34 61 40 / 0 0 0 0
WINFIELD-KWLD 60 36 63 42 / 0 0 0 0
RUSSELL 61 36 60 39 / 0 0 0 0
GREAT BEND 63 36 60 39 / 0 0 0 0
SALINA 52 33 59 38 / 0 0 0 0
MCPHERSON 55 34 59 39 / 0 0 0 0
COFFEYVILLE 54 32 61 42 / 0 0 0 0
CHANUTE 50 31 60 40 / 0 0 0 0
IOLA 49 31 59 39 / 0 0 0 0
PARSONS-KPPF 52 32 61 42 / 0 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR KSZ032-033-
047>052-067>069-083.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
654 AM CST MON FEB 9 2015
.UPDATE...
ISSUED AT 654 AM CST MON FEB 9 2015
WITH LOW VISIBILITIES ALONG AND BEHIND THE LEADING EDGE OF THE
STRATUS...HAVE ISSUED A DENSE FOG ADVISORY FOR A PORTION OF
CENTRAL KANSAS THROUGH 15Z. VISIBILITIES MAY LIFT SOME AFTER
INITIAL DROP ALONG THE LEADING EDGE...BUT FEEL EVEN PATCHY DENSE
FOG MAY CAUSE PROBLEMS FOR TRAVELERS ALONG I-70.
BILLINGS WRIGHT
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 348 AM CST MON FEB 9 2015
TODAY-TONIGHT:
BACKDOOR COLD FRONT WILL CONTINUE TO PUSH ACROSS THE AREA...WITH
LOW CLOUDS GRADUALLY SPREADING INTO AT LEAST THE NE HALF OF THE
FORECAST AREA. APPEARS THAT FRONT WILL SAG A BIT FURTHER SOUTH/
WEST THAN PREVIOUS ANTICIPATED. SOME CONCERN FOR TRANSIENT DENSE
FOG ALONG LEADING EDGE OF COLDER AIR...WITH 1-4 MILE VISIBILITY
FOG FURTHER INTO THE POST FRONTAL AIRMASS. BEST SETUP FOR DENSE
FOG APPEARS TO BE JUST NORTH OF FORECAST AREA. SURFACE RIDGE WILL
QUICKLY OVERSPREAD THE AREA DURING THE DAY AND WEAK RETURN FLOW
DEVELOPS TONIGHT. THIS WILL MAKE LOWS A BIT TRICKY AS WELL.
TUE-WED:
WEAK RETURN FLOW CONTINUE ON TUE WITH SLIGHT REBOUND IN
TEMPERATURES IN THE NE HALF OF FORECAST AREA. THE NEXT SURGE OF
COLDER AIR WILL ARRIVE TUE NIGHT...WITH COLD AIR ADVECTION
INCREASING DURING THE DAY WED. TEMPERATURES WILL LIKELY
ROLLER COASTER DURING THE DAY AS COLD AIR ADVECTION AND
INSOLATION VARY. PRECIPITATION CHANCES WITH FRONT LOOK TO BE QUITE
LOW GIVEN RELATIVELY DRY LOW LEVEL AIR. -HOWERTON
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 348 AM CST MON FEB 9 2015
GFS/ECMWF IN FAIRLY GOOD AGREEMENT WITH RIDGE BUILDING IN THE
WESTERN US AND TROUGHING IN THE EAST. BOTH SHOW A LARGE SURFACE
HIGH OVERSPREADING THE CENTRAL US...SENDING MUCH COOLER AIR INTO
THE AREA ON SAT...WHICH WILL PERSIST INTO SUN. ALWAYS A TOUGH
CALL...DESPITE MODEL AGREEMENT...AS SLIGHTLY MORE ZONAL UPPER
FLOW COULD SHUNT COLDEST AIR EAST OF THE AREA. HOWEVER THERE WAS
SUFFICIENT AGREEMENT BETWEEN MODELS AND SURROUNDING OFFICES TO
HEDGE COOLER THAN GUIDANCE AT THIS POINT. -HOWERTON
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 559 AM CST MON FEB 9 2015
CHALLENGING MORNING FOR AVIATION WITH MVFR TO IFR AND POSSIBLY
SOME LIFR CEILINGS/VISIBILITY MOVING IN WITH THE BACKDOOR FRONT
FROM THE NORTHWEST. THE RR AND HRRR HAVE DONE WELL WITH THE
PROGRESSION OF THE LOW CLOUDS OVER THE PAST FEW HOURS AND REALLY
FOCUSED ON IT FOR THE FIRST PART OF THE FORECAST. FEEL KRSL/KSLN
WILL FEEL THE BRUNT OF THE WORST CONDITIONS WITH KHUT/KICT AND
KCNU HAVING SOME MODERATE MVFR IMPACTS. THE LOWEST
CEILINGS/VISIBILITY WITH IFR TO LIFR CRITERIA ARE EXPECTED ALONG
THE WESTWARD MOVING ADVANCEMENT OF THE STRATUS WHICH WILL IMPACT
KRSL/KSLN THIS MORNING. THIS PROGRESSION WILL STOP BY MID MORNING
AND LOW CLOUDS WILL ERODE BY AFTERNOON WITH VFR CONDITIONS
EXPECTED TO RETURN. NORTHERLY WINDS WILL BECOME EASTERLY AND
EVENTUALLY SOUTHEASTERLY DURING THE DAY AND THROUGHOUT THE
OVERNIGHT HOURS.
BILLINGS WRIGHT
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 57 35 61 41 / 0 0 0 0
HUTCHINSON 58 35 60 40 / 0 0 0 0
NEWTON 54 34 59 39 / 0 0 0 0
ELDORADO 54 34 61 40 / 0 0 0 0
WINFIELD-KWLD 60 36 63 42 / 0 0 0 0
RUSSELL 61 36 60 39 / 0 0 0 0
GREAT BEND 63 36 60 39 / 0 0 0 0
SALINA 52 33 59 38 / 0 0 0 0
MCPHERSON 55 34 59 39 / 0 0 0 0
COFFEYVILLE 54 32 61 42 / 0 0 0 0
CHANUTE 50 31 60 40 / 0 0 0 0
IOLA 49 31 59 39 / 0 0 0 0
PARSONS-KPPF 52 32 61 42 / 0 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR KSZ032-033-
048-049.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
559 AM CST MON FEB 9 2015
...UPDATED FOR 12Z AVIATION DISCUSSION...
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 348 AM CST MON FEB 9 2015
TODAY-TONIGHT:
BACKDOOR COLD FRONT WILL CONTINUE TO PUSH ACROSS THE AREA...WITH
LOW CLOUDS GRADUALLY SPREADING INTO AT LEAST THE NE HALF OF THE
FORECAST AREA. APPEARS THAT FRONT WILL SAG A BIT FURTHER SOUTH/
WEST THAN PREVIOUS ANTICIPATED. SOME CONCERN FOR TRANSIENT DENSE
FOG ALONG LEADING EDGE OF COLDER AIR...WITH 1-4 MILE VISIBILITY
FOG FURTHER INTO THE POST FRONTAL AIRMASS. BEST SETUP FOR DENSE
FOG APPEARS TO BE JUST NORTH OF FORECAST AREA. SURFACE RIDGE WILL
QUICKLY OVERSPREAD THE AREA DURING THE DAY AND WEAK RETURN FLOW
DEVELOPS TONIGHT. THIS WILL MAKE LOWS A BIT TRICKY AS WELL.
TUE-WED:
WEAK RETURN FLOW CONTINUE ON TUE WITH SLIGHT REBOUND IN
TEMPERATURES IN THE NE HALF OF FORECAST AREA. THE NEXT SURGE OF
COLDER AIR WILL ARRIVE TUE NIGHT...WITH COLD AIR ADVECTION
INCREASING DURING THE DAY WED. TEMPERATURES WILL LIKELY
ROLLER COASTER DURING THE DAY AS COLD AIR ADVECTION AND
INSOLATION VARY. PRECIPITATION CHANCES WITH FRONT LOOK TO BE QUITE
LOW GIVEN RELATIVELY DRY LOW LEVEL AIR. -HOWERTON
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 348 AM CST MON FEB 9 2015
GFS/ECMWF IN FAIRLY GOOD AGREEMENT WITH RIDGE BUILDING IN THE
WESTERN US AND TROUGHING IN THE EAST. BOTH SHOW A LARGE SURFACE
HIGH OVERSPREADING THE CENTRAL US...SENDING MUCH COOLER AIR INTO
THE AREA ON SAT...WHICH WILL PERSIST INTO SUN. ALWAYS A TOUGH
CALL...DESPITE MODEL AGREEMENT...AS SLIGHTLY MORE ZONAL UPPER
FLOW COULD SHUNT COLDEST AIR EAST OF THE AREA. HOWEVER THERE WAS
SUFFICIENT AGREEMENT BETWEEN MODELS AND SURROUNDING OFFICES TO
HEDGE COOLER THAN GUIDANCE AT THIS POINT. -HOWERTON
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 559 AM CST MON FEB 9 2015
CHALLENGING MORNING FOR AVIATION WITH MVFR TO IFR AND POSSIBLY
SOME LIFR CEILINGS/VISIBILITY MOVING IN WITH THE BACKDOOR FRONT
FROM THE NORTHWEST. THE RR AND HRRR HAVE DONE WELL WITH THE
PROGRESSION OF THE LOW CLOUDS OVER THE PAST FEW HOURS AND REALLY
FOCUSED ON IT FOR THE FIRST PART OF THE FORECAST. FEEL KRSL/KSLN
WILL FEEL THE BRUNT OF THE WORST CONDITIONS WITH KHUT/KICT AND
KCNU HAVING SOME MODERATE MVFR IMPACTS. THE LOWEST
CEILINGS/VISIBILITY WITH IFR TO LIFR CRITERIA ARE EXPECTED ALONG
THE WESTWARD MOVING ADVANCEMENT OF THE STRATUS WHICH WILL IMPACT
KRSL/KSLN THIS MORNING. THIS PROGRESSION WILL STOP BY MID MORNING
AND LOW CLOUDS WILL ERODE BY AFTERNOON WITH VFR CONDITIONS
EXPECTED TO RETURN. NORTHERLY WINDS WILL BECOME EASTERLY AND
EVENTUALLY SOUTHEASTERLY DURING THE DAY AND THROUGHOUT THE
OVERNIGHT HOURS.
BILLINGS WRIGHT
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 57 35 61 41 / 0 0 0 0
HUTCHINSON 58 35 60 40 / 0 0 0 0
NEWTON 54 34 59 39 / 0 0 0 0
ELDORADO 54 34 61 40 / 0 0 0 0
WINFIELD-KWLD 60 36 63 42 / 0 0 0 0
RUSSELL 61 36 60 39 / 0 0 0 0
GREAT BEND 63 36 60 39 / 0 0 0 0
SALINA 52 33 59 38 / 0 0 0 0
MCPHERSON 55 34 59 39 / 0 0 0 0
COFFEYVILLE 54 32 61 42 / 0 0 0 0
CHANUTE 50 31 60 40 / 0 0 0 0
IOLA 49 31 59 39 / 0 0 0 0
PARSONS-KPPF 52 32 61 42 / 0 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
534 AM CST Mon Feb 9 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 156 AM CST MON FEB 9 2015
Backdoor cold front has pushed southwest through the forecast
area overnight as another weak wave tracked into the mid MS
valley. Behind the front cold air advection has caused fog and
stratus as a weak surface ridge slides through NE and into KS
later today. The lowest visibilities are currently located on the
western edge of the fog/stratus over south central NE. Winds
should decrease as the ridge approaches the forecast area limiting
the amount of mixing as most sites are only a few degrees away
from saturation. Several runs of the SREF and HRRR show that dense
fog may try to build into north central KS this morning therefore
have kept the mention of fog in the forecast. Not confident if the
visibilities will warrant an advisory at this point and or when
they will improve. It appears that eastern KS will only experience
minor visibility restrictions through mid morning hours. The more
solid fog in north central KS may try to hold on until late
morning, but should lift into a stratus deck by noon. Stratus and
or fog should push over the entire area within the next few hours
although the question is how long it sticks around today. As of
now most of the guidance is suggesting clouds last most of the
daytime hours, but may begin to scatter out on the southern edge.
Regardless have lowered the high temperatures today due to the
uncertainty of the cloud cover, which should roughly range from 40
in far northeast KS to 50 in central KS. By tonight the surface
high retreats eastward allowing return flow. The better chances
for stratus tonight will push slightly westward into central KS
and central NE ahead of the next shortwave forecast to track over
the northern plains.
.LONG TERM...(Tuesday through Sunday)
Issued at 156 AM CST MON FEB 9 2015
Another above normal day is on track for Tuesday, as area remains
between systems and under warm nose aloft. Highs forecast to mix
from the lower 50s northeast to near 60 in the west. GFS is faster
with the arrival of the front and has it through much of the area
by sunrise while NAM remains slower, bisecting the CWA by sunrise.
Think a well mixed boundary layer will keep overnight lows up in
the 30s, and may rise in the morning if frontal boundary is
slower, but otherwise expect steady to falling temperatures on
Wednesday afternoon. Highs in the lower 40s may occur early. Lows
fall quickly into the teens as the cold high moves due south into
the Central Plains. Cold advection slowly moderates and shifts
east into Thursday but highs only around 20 in the northeast to
lower 30s in the southern counties.
Large scale longwave trof setting up over the Eastern half of the
US is persistent in sending rounds of cold air nearly due
southward out of central Canada into the Plains for late week into
the weekend. Friday still a transition day between cold surges and
brings a rebound back into the 40s to near 50 for high
temperatures before more cold air comes southward for Saturday.
Trend for the eastern trof is deeper and farther south and west,
however it does appear to progress to the east later in the
weekend as the upper jet rounds the base of the trof and next
shortwave across Canada aids in an easterly trend. Temperatures in
the 30s to low 40s could be generous for Saturday, as may be the
forecast lows in the upper teens, but could start to see
moderating influences by Sunday. Kept a near normal temperature
forecast in the upper 30s to lower 40s for Sunday.
&&
.AVIATION...(For the 12Z TAFs through 12Z Tuesday Morning)
Issued at 521 AM CST MON FEB 9 2015
MVFR/IFR conditions will continue through the afternoon hours.
Visibilities are expected to improve later this morning. The main
uncertainty will be the timing of when the stratus scatters out.
For now have gone with conditions improving around 19-20Z although
the clouds edge could set up near the taf sites. There is a chance
visibilities could decrease to MVFR early tomorrow morning.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY until 9 AM CST this morning FOR KSZ008-020-
034.
&&
$$
SHORT TERM...Sanders
LONG TERM...67
AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
525 AM CST MON FEB 9 2015
...UPDATED FOR AVIATION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 341 AM CST MON FEB 9 2015
THE UPPER LEVEL RIDGE OVER THE ROCKIES THE LAST COUPLE OF DAYS
WILL SLOWLY SHIFT EASTWARD INTO THE PLAINS DURING THE SHORT TERM
PERIOD. A STRONG 100+ KNOT 250 MB JET WILL BE OBSERVED NORTH OF
THIS RIDGE, WITH ITS MAXIMUM LOCATED MAINLY NORTH OF THE FORECAST
AREA. DRY CONDITIONS CONTINUE IN THE MID TO UPPER LEVELS OF THE
ATMOSPHERE LEADING TO MOSTLY CLEAR SKIES TODAY THROUGH TONIGHT.
WINDS WILL GENERALLY BE FROM THE NORTHWEST THIS MORNING, SHIFTING
TO THE SOUTH SOUTHEAST BY NOON AS LEE TROUGHING INTENSIFIES ACROSS
EASTERN COLORADO. AS FOR TEMPERATURES, ANOTHER MILD DAY IS IN
STORE WITH HIGHS RANGING FROM THE MID 60S ACROSS CENTRAL AND SOUTH
CENTRAL KANSAS TO LOWER 70S ACROSS FAR SOUTHWESTERN KANSAS. LOWS
TONIGHT ARE FORECASTED TO DIP INTO THE MID TO UPPER 30S WITH A FEW
AREAS REACHING AROUND 40 DEGREES ACROSS THE KS/OK BORDER.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 228 AM CST MON FEB 9 2015
A SHORTWAVE TROUGH WILL MOVE ACROSS THE PLAINS ON WEDNESDAY WITH AN
ASSOCIATED COLD FRONT. MODEL FORECAST SOUNDINGS LOOK TOO DRY TO
SUPPORT ANY PRECIP REACHING THE GROUND, SO HAVE LOWERED POPS TO LESS
THAN 15 PERCENT. AHEAD OF THE TROUGH ON TUESDAY, HIGH TEMPS WILL
STILL BE MILD IN THE MID TO UPPER 60S WITH MOSTLY SUNNY SKIES. HIGHS
FALL BACK INTO THE MID 40S IN SOUTH CENTRAL SECTIONS TO AROUND 50
ELSEWHERE ACROSS SOUTHWESTERN KANSAS ON WEDNESDAY BEHIND THE COLD
FRONT WITH INCREASING CLOUDS.
DRY AND WARMER NORTHWEST FLOW ALOFT FOLLOWS THE SHORTWAVE TROUGH ON
THURSDAY INTO FRIDAY, WITH HIGHS IN THE 50S CENTRAL TO 60S FAR
WEST, ON THURSDAY, WARMING INTO THE 60S FRIDAY.
MODELS IN GOOD AGREEMENT ON SATURDAY WITH A SHORTWAVE TROUGH IN
NORTHWEST FLOW ALOFT MOVING FROM CENTRAL CANADA AND INTO THE
MISSISSIPPI VALLEY. THIS SYSTEM LOOKS TO PUSH AN ARCTIC SURGE INTO
THE PLAINS AS A 1045 MB SURFACE HIGH DEVELOPS ACROSS THE NORTHERN
PLAINS. WILL GO AHEAD AND START TRENDING TOWARD COLDER HIGHS FROM
AROUND 50 OVER SOUTH CENTRAL SECTIONS, AND AROUND 60 TO 65 FAR
SOUTHWEST, WITH THIS ARCTIC SURGE. ACTUAL HIGHS COULD BE 10 TO 20
DEGREES COLDER THAN THIS. LATER SHIFTS WILL LIKELY NEED TO TREND
EVEN COLDER. CONSENSUS WAS REACHED TO AT LEAST TREND TOWARD THE
COLDER TEMPS IN THE GRIDS THAN WHAT THE NEW REGIONAL GUIDANCE HAD.
FOR SUNDAY, WARMER RETURN FLOW MOVES BACK INTO WESTERN KANSAS AS THE
ARCTIC SURFACE HIGH MOVES EAST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 519 AM CST MON FEB 9 2015
VFR CONDITIONS ARE EXPECTED TODAY INTO THE EVENING. SOME LOW
STRATUS AND FOG WILL APPROACH THE KHYS TERMINAL FOR A FEW HOURS
THIS MORNING PER HRRR AND RAP MODEL FORECASTS AS A DOME OF HIGH
PRESSURE BUILDS INTO CENTRAL KANSAS. A LEE TROUGH ALSO DEVELOPS
TODAY WITH LIGHT AND VARIABLE WINDS THIS MORNING BECOMING
SOUTHEASTERLY UPSLOPE THIS AFTERNOON AND EVENING AT 10-15KT. SOME
LOW STRATUS AND FOG IS POSSIBLE TOWARDS THE END OF THE TAF PERIOD
FOR KDDC AND KHYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 68 38 65 37 / 0 0 0 0
GCK 70 35 67 37 / 0 0 0 10
EHA 72 40 68 36 / 0 0 0 10
LBL 73 36 69 37 / 0 0 0 0
HYS 66 36 62 38 / 0 0 0 0
P28 66 37 63 40 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HOVORKA_42
LONG TERM...KRUSE
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS TOPEKA KS
256 AM CST Mon Feb 9 2015
.SHORT TERM...(Today and Tonight)
Issued at 156 AM CST MON FEB 9 2015
Backdoor cold front has pushed southwest through the forecast
area overnight as another weak wave tracked into the mid MS
valley. Behind the front cold air advection has caused fog and
stratus as a weak surface ridge slides through NE and into KS
later today. The lowest visibilities are currently located on the
western edge of the fog/stratus over south central NE. Winds
should decrease as the ridge approaches the forecast area limiting
the amount of mixing as most sites are only a few degrees away
from saturation. Several runs of the SREF and HRRR show that dense
fog may try to build into north central KS this morning therefore
have kept the mention of fog in the forecast. Not confident if the
visibilities will warrant an advisory at this point and or when
they will improve. It appears that eastern KS will only experience
minor visibility restrictions through mid morning hours. The more
solid fog in north central KS may try to hold on until late
morning, but should lift into a stratus deck by noon. Stratus and
or fog should push over the entire area within the next few hours
although the question is how long it sticks around today. As of
now most of the guidance is suggesting clouds last most of the
daytime hours, but may begin to scatter out on the southern edge.
Regardless have lowered the high temperatures today due to the
uncertainty of the cloud cover, which should roughly range from 40
in far northeast KS to 50 in central KS. By tonight the surface
high retreats eastward allowing return flow. The better chances
for stratus tonight will push slightly westward into central KS
and central NE ahead of the next shortwave forecast to track over
the northern plains.
.LONG TERM...(Tuesday through Sunday)
Issued at 156 AM CST MON FEB 9 2015
Another above normal day is on track for Tuesday, as area remains
between systems and under warm nose aloft. Highs forecast to mix
from the lower 50s northeast to near 60 in the west. GFS is faster
with the arrival of the front and has it through much of the area
by sunrise while NAM remains slower, bisecting the CWA by sunrise.
Think a well mixed boundary layer will keep overnight lows up in
the 30s, and may rise in the morning if frontal boundary is
slower, but otherwise expect steady to falling temperatures on
Wednesday afternoon. Highs in the lower 40s may occur early. Lows
fall quickly into the teens as the cold high moves due south into
the Central Plains. Cold advection slowly moderates and shifts
east into Thursday but highs only around 20 in the northeast to
lower 30s in the southern counties.
Large scale longwave trof setting up over the Eastern half of the
US is persistent in sending rounds of cold air nearly due
southward out of central Canada into the Plains for late week into
the weekend. Friday still a transition day between cold surges and
brings a rebound back into the 40s to near 50 for high
temperatures before more cold air comes southward for Saturday.
Trend for the eastern trof is deeper and farther south and west,
however it does appear to progress to the east later in the
weekend as the upper jet rounds the base of the trof and next
shortwave across Canada aids in an easterly trend. Temperatures in
the 30s to low 40s could be generous for Saturday, as may be the
forecast lows in the upper teens, but could start to see
moderating influences by Sunday. Kept a near normal temperature
forecast in the upper 30s to lower 40s for Sunday.
&&
.AVIATION...(For the 06Z TAFs through 06Z Monday Night)
Issued at 1120 PM CST SUN FEB 8 2015
A complicated TAF period ahead with stratus moving toward TAF
sites scheduled to arrive between 07Z and 08Z. MHK should be
firmly in stratus with IFR to LIFR cig heights and occasion vis
restrictions to 2SM or less. TOP/FOE will initially be on the
edge of the stratus, and could see IFR cigs, low MVFR cigs, or
even a bit of clearing. Vis should decrease to 3-5 SM regardless,
and have more confidence in IFR to low MVFR cigs will build in
after 10Z. Stratus looks likely to hold strong into late morning
and possibly well into the afternoon before scattering to VFR.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Sanders
LONG TERM...67
AVIATION...Barjenbruch
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1155 PM CST SUN FEB 8 2015
.DISCUSSION...
FOR THE 06Z TAF PACKAGE.
&&
.AVIATION...
DEVELOPMENT OF CLOUD DECK AROUND 4-5K FT AND PERSISTENT ALBEIT
LIGHT WINDS HAS DELAYED FOG FORMATION OR AT LEAST KEPT IT FROM
BECOMING TOO WIDESPREAD/DENSE THUS FAR. LIGHTER WINDS AND A CLEAR
SKY HAS RESULTED IN IFR/LIFR AT THE ACADIANA TERMINALS...THOUGH
THE INFLUX OF CLOUDS FROM THE NW MAY DISRUPT THIS/RESULT IN VSBYS
BOUNCING AROUND A BIT...AS THEY ARE AT KBPT. OTHERWISE...THERE
REMAINS THE POTENTIAL AT KLCH...WITH KAEX THE ONLY TERMINAL WHERE
IFR WAS REMOVED. INCREASING NORTH WINDS/DIURNAL MIXING WILL ERODE
ANY FOG BY MID MORNING...WITH VFR EXPECTED TO PREVAIL FOR THE REST
OF MONDAY.
13
&&
.PREV DISCUSSION... /ISSUED 914 PM CST SUN FEB 8 2015/
DISCUSSION...
SFC ANALYSIS SHOWS COLLAPSING PRESSURE GRADIENT AHEAD OF THE
FRONT OVER C TO NE TX/NW LA...WITH CALM WINDS AREAWIDE. IR SAT
AND SFC OBS SHOWS MID LEVEL OVC DECK DEVELOPING ACROSS SE TX TO C
LA...WITH SFC TEMPS/DEWPTS WITHIN A DEGREE OR TWO NEAR 60/LOWER
60S. PATCHY GROUND FOG JUST OUTSIDE THE NWS OFFICE A HINT OF
THINGS TO COME THIS EVENING AND OVERNIGHT. LATEST HRRR GUIDANCE
AGREES WITH PREVIOUS FORECAST AND OTHER NUMERICAL GUIDANCE...GOING
FOR PATCHY FOG THIS EVENING...GRADUALLY GROWING TO AREAS OF FOG
WITH VIS BELOW ONE MILE POSSIBLE BETWEEN MIDNIGHT TO DAYBREAK. THE
STRONGEST SIGNAL CONTINUES TO ALONG AND SOUTH OF U.S. 190 TO THE
COAST AND THE NEAR COASTAL WATERS OUT 20 NM.
FOR THE UPDATES...REFRESHED TEMP/DEWPT GRIDS AND ENHANCED THE FOG
WORDING FOR INLAND AREAS & COASTAL LAKES/BAYS AND COASTAL WATERS
OUT 20 NM. DEPENDING ON VIS TRENDS...A DENSE FOG ADVISORY MAY HAVE
TO BE ISSUED FOR PORTIONS OF THE AREA OVERNIGHT. BY DAYBREAK...THE
FRONT IS EXPECTED TO BE APPROACHING THE COAST...WITH VIS
DRASTICALLY IMPROVING BEHIND THE FRONT INLAND. MARINE FOG MAY
LINGER INTO THE MID MORNING HOURS...BUT EXPECTED TO BE GONE BY THE
LATE MORNING AND AFTERNOON.
DML
PREV DISCUSSION... /ISSUED 557 PM CST SUN FEB 8 2015/
DISCUSSION...
FOR THE 00Z TAF PACKAGE.
AVIATION...
CURRENTLY VFR AT ALL SITES...BUT THAT IS EXPECTED TO CHANGE LATER
TONIGHT AS MODEL TIME HEIGHTS/FCST SOUNDINGS AND DETERMINISTIC
GUIDANCE ALL SUGGEST FOG FORMATION AHEAD OF AN APPROACHING COLD
FRONT. SAW LITTLE REASON TO DEVIATE FROM INHERITED TAF PACKAGE IN
THIS REGARD. VFR TO PREVAIL TOMORROW AMID GUSTY NORTH WINDS AND
DRIER AIR SPILLING IN BEHIND THE FRONT.
13
PREV DISCUSSION... /ISSUED 403 PM CST SUN FEB 8 2015/
DISCUSSION...
VERY NICE SPRING DAY ON TAP AS TEMPS CLIMBED INTO THE LOWER 70S
MOST LOCATIONS. TONIGHT WILL SEE A WEAK FRONT PUSH THROUGH THE
REGION. LOOKING FOR SOME FOG AND A FEW SHOWERS/DRIZZLE PRIOR TO
THE FRONTAL PASSAGE. SKIES CLEARING TOMORROW WITH TEMPS BACK INTO
THE 70S... COULD SPRING FINALLY BE HERE. CLOSE MAYBE.
ANYWAY... A VERY QUIET WEATHER PATTERN IN STORE THIS WEEK WITH THE
NEXT FRONT EXPECTED THROUGH ON THURSDAY. THIS WILL BRING TEMPS
BACK DOWN ON THE CHILLY SIDE TOWARDS LATE IN THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 56 74 44 64 / 20 10 0 0
KBPT 56 74 48 67 / 20 10 0 0
KAEX 54 72 41 61 / 20 10 0 0
KLFT 56 73 44 62 / 20 10 0 0
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1029 PM CST SUN FEB 8 2015
.AVIATION...
COLD FRONT HAS MOVED SOUTH OF OUR TERMINAL LOCATIONS THIS EVENING
AND WITH IT...ANY CHANCE OF ANY ISOLATED SHOWER ACTIVITY SHOULD
REMAIN SOUTH AND EAST OF OUR TERMINALS THROUGH THE REMAINDER OF
THE NIGHT. IR IMAGERY DOES SHOW THE REDEVELOPMENT OF A
STRATOCUMULUS LAYER AROUND 4-5KFT JUST SOUTH OF THE CORRIDOR.
THERE IS VIRTUALLY NO DRIER AIR WITH THE FRONTAL PASSAGE AND AS A
RESULT...WE ARE BEGINNING TO SEE SOME PATCHY FOG DEVELOP ACROSS S
AR/NE TX AND N LA TERMINALS. IN FACT...AS OF 0430Z...THE ELD
TERMINAL VSBY HAS DROPPED TO 1/4SM WITH 1HDFT VV. THIS IS IN GOOD
AGREEMENT WITH THE HRRR WHICH HAS HIGH RH VALUES ACROSS VIRTUALLY
ALL OF OUR TERMINAL AIRSPACE OVERNIGHT. HAVE ADDED THIS
POSSIBILITY TO THE 06Z TAF PACKAGE.
AFTER SUNRISE...LOOKING FOR VFR CONDITIONS TO PREVAIL. NNW WINDS
WILL INCREASE TO AROUND 10KTS ACROSS ALL TERMINAL LOCATIONS BEFORE
DECOUPLING AROUND 00Z TUE.
13
&&
.PREV DISCUSSION... /ISSUED 1022 PM CST SUN FEB 8 2015/
DISCUSSION...
MAIN CONCERN FOR THE UPDATE THIS EVENING WILL BE THE POTENTIAL FOR
FOG DEVELOPMENT. DEWPOINT SPREADS ARE NARROW ATTM...AND WITH VERY
LITTLE DRY AIR IN THE WAKE OF THE PASSING COLD FRONT COMBINED WITH
LIGHT WINDS AND CLEARING SKIES...WE ARE ALREADY SEEING FOG
DEVELOPMENT OVER SRN AR. HAVE ADDED PATCHY DENSE FOG WORDING TO
THE GRIDS AREAWIDE.
HAVE LEFT 20 POPS ACROSS THE SERN SECTIONS OF THE REGION AS THE
COLD FRONT IS STILL MAKING ITS WAY ACROSS THESE AREAS. RECENT CU
DEVELOPMENT OVER THESE AREAS SUGGESTS THAT WE COULD STILL SEE A
SHWR OR TWO. OTHERWISE...THE GRIDS ARE IN GOOD SHAPE AND NO OTHER
CHANGES ARE ANTICIPATED ATTM.
/12/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 49 71 40 65 42 / 10 0 0 0 0
MLU 51 69 37 60 37 / 20 0 0 0 0
DEQ 39 69 37 63 40 / 0 0 0 0 0
TXK 47 68 39 63 40 / 10 0 0 0 0
ELD 47 66 36 60 38 / 10 0 0 0 0
TYR 48 72 42 70 45 / 10 0 0 0 0
GGG 47 72 42 68 44 / 10 0 0 0 0
LFK 53 74 43 71 45 / 20 0 0 0 0
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
12/13
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1022 PM CST SUN FEB 8 2015
.DISCUSSION...
MAIN CONCERN FOR THE UPDATE THIS EVENING WILL BE THE POTENTIAL FOR
FOG DEVELOPMENT. DEWPOINT SPREADS ARE NARROW ATTM...AND WITH VERY
LITTLE DRY AIR IN THE WAKE OF THE PASSING COLD FRONT COMBINED WITH
LIGHT WINDS AND CLEARING SKIES...WE ARE ALREADY SEEING FOG
DEVELOPMENT OVER SRN AR. HAVE ADDED PATCHY DENSE FOG WORDING TO
THE GRIDS AREAWIDE.
HAVE LEFT 20 POPS ACROSS THE SERN SECTIONS OF THE REGION AS THE
COLD FRONT IS STILL MAKING ITS WAY ACROSS THESE AREAS. RECENT CU
DEVELOPMENT OVER THESE AREAS SUGGESTS THAT WE COULD STILL SEE A
SHWR OR TWO. OTHERWISE...THE GRIDS ARE IN GOOD SHAPE AND NO OTHER
CHANGES ARE ANTICIPATED ATTM. /12/
&&
.PREV DISCUSSION... /ISSUED 448 PM CST SUN FEB 8 2015/
AVIATION...
COLD FRONT WAS NEAR A HRO...GYI...SEP...JCT LINE AS OF 22Z THIS
AFTN. FRONT SHOULD REALLY PICK UP SPEED THIS EVENING AND SHOULD
PUSH THROUGH ALL OUR TERMINAL LOCATIONS BEFORE 06Z TNGT. AHEAD OF
THE FRONT...EXTENSIVE CU FIELD EXISTS WITH HEIGHTS RANGING FROM
4-6KFT. THIS CU FIELD IS AFFECTING ALL TERMINALS...ALBEIT A LITTLE
THIN IN AND AROUND THE TYR/GGG AND MLU TERMINALS WHERE MIXING HAS
HELPED TO CREATE A FEW BREAKS IN THE OVC. THE BACK EDGE OF THIS
CLOUD COVER WAS ADVANCING SOUTHEAST NEAR 18-20KTS AND THUS...THE
TXK AND TYR TERMINALS WILL HAVE LIKELY LOST THEIR LOWER CEILINGS
WITH THE 00Z TAF PACKAGE.
LATEST RUN OF THE HRRR SUGGESTS SOME ISOLATED TO WIDELY SCATTERED
SHOWERS DEVELOPING MAINLY SOUTH OF THE I-20 CORRIDOR...POSSIBLY
EFFECTING THE LFK/MLU TERMINALS. THIS SEEMS POSSIBLE AS FRONTAL
FORCING WILL BE A LITTLE STRONGER IN THE VICINITY OF THESE TWO
TERMINALS. MENTIONED VCSH FOR A FEW HOURS THIS EVENING FOR THESE
LOCATIONS UNTIL THE FRONT BYPASSES THEM AFTER MIDNIGHT.
OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD.
EXPECTING A WEAK WIND SHIFT WITH THE FRONTAL PASSAGE THIS EVENING
WITH WINDS BECOMING NW. A MORE NORTHERLY DIRECTION IS EXPECTED BY
MID TO LATE MORNING ON MONDAY WITH SPEEDS PICKING UP TO AROUND
8-10KTS WITH SUFFICIENT MIXING.
13
PREV DISCUSSION... /ISSUED 349 PM CST SUN FEB 8 2015/
DISCUSSION...
GENERALLY QUIET WEATHER IS EXPECTED OVER THE NEXT SEVERAL DAYS
WITH ABOVE NORMAL TEMPERATURES EXPECTED THROUGH THURSDAY AND VERY
LITTLE OF THE WAY OF RAIN CHANCES.
PERSISTENT STRATUS DECK HAS BEEN SCATTERING OUT SOUTH OF I-20
TODAY BUT A THICK BAND OF CLOUD COVER WILL MOVE ACROSS THE AREA
AHEAD OF A SFC TROUGH. THE TROUGH WILL MOVE ACROSS THE AREA THIS
EVENING/TONIGHT AND SKIES SHOULD RAPIDLY CLEAR AFTER IT PASSES AS
WINDS SHIFT TO THE NORTH AND DRIER AIR WORKS INTO THE REGION. MID
LVL SHORTWAVE TROUGH CURRENTLY OVER NRN KS WILL DIVE SEWD AND
COULD PROVIDE SOME ADDITIONAL ASCENT ALONG THE SFC BOUNDARY TO
DEVELOP A FEW SHWRS SOUTH OF I-20 TONIGHT. I CONSIDERED REMOVING
POPS COMPLETELY TONIGHT AS IT APPEARS FROM THE LATEST WV LOOPS
THAT THE SHORTWAVE MAY TRACK A LITTLE FARTHER NORTH AND AWAY FROM
THE SFC BOUNDARY THAN THE MODEL GUIDANCE SUGGESTS. HOWEVER...CANNOT
COMPLETELY RULE OUT A COUPLE OF SHWRS SO WILL MAINTAIN THE SLIGHT
CHANCE POPS.
UPPER RIDGING AND A SFC HIGH PRESSURE SHOULD DOMINATE OUR WEATHER
FOR MONDAY AND TUESDAY. VAST MAJORITY OF THE MODELS WERE WAY TOO
COOL WITH THEIR MAX TEMP FORECASTS FOR TODAY. LOOKING UPSTREAM
BEHIND THE TROUGH IN OK...TEMPS HAVE BEEN WARMER THAN OURS WITH
SOME LOCATIONS NEAR OR ABOVE 80 DEGREES F. GIVEN THE CONDITIONS
UPSTREAM AND WITH MOSTLY CLEAR SKIES...PLENTY OF DRY AIR...AND
UPPER RIDGING EXPECTED OVERHEAD...MAX TEMPS ON MONDAY SHOULD BE
NEAR IF NOT WARMER THAN TODAY SO HAVE GONE WARMER THAN MOST OF THE
MODELS. TEMPS MAY BE A BIT COOLER ON TUESDAY AS THE LOW LVL FLOW
BECOMES ELY WHICH COULD ADVECT SOME SLIGHTLY COOLER AIR INTO THE
REGION. TEMPS SHOULD REBOUND BACK TO NEAR OR ABOVE 70 DEGREES F ON
WEDNESDAY AHEAD OF OUR NEXT COLD FRONT.
COLD FRONT SHOULD ARRIVE LATE WEDNESDAY/EARLY FRIDAY. LATEST
MODELS GENERALLY MAINTAIN A DRY FORECAST AND THIS MAKES SENSE AS
THERE WILL BE LITTLE TIME FOR DEEP LAYER MOISTURE TO BUILD PRIOR
TO THE FRONT/S ARRIVAL. COLDER AIR WILL ARRIVE BEHIND THE FRONT
WHICH SHOULD COOL TEMPS BACK TO NEAR CLIMO FOR THE END OF THE WORK
WEEK FOLLOWED BY ANOTHER WARMING TREND HEADING INTO NEXT WEEKEND.
/09/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 49 71 40 65 42 / 10 0 0 0 0
MLU 51 69 37 60 37 / 20 0 0 0 0
DEQ 39 69 37 63 40 / 0 0 0 0 0
TXK 47 68 39 63 40 / 10 0 0 0 0
ELD 47 66 36 60 38 / 10 0 0 0 0
TYR 48 72 42 70 45 / 10 0 0 0 0
GGG 47 72 42 68 44 / 10 0 0 0 0
LFK 53 74 43 71 45 / 20 0 0 0 0
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
12
AREA FORECAST DISCUSSION
NWS CARIBOU ME
415 PM EST MON FEB 9 2015
.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY MOVE NORTH OF THE REGION THROUGH
WEDNESDAY. NEW LOW PRESSURE FROM THE GREAT LAKES WILL REFORM OFF
THE MID ATLANTIC STATES ON THURSDAY AND WILL STRENGTHEN AS IT
TRACKS SOUTH OF NOVA SCOTIA ON FRIDAY.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
DESPITE RADAR REF RETURNS OVR CNTRL AND DOWNEAST ME...COLD AND DRY
LLVL AIR IS PREVENTING MUCH IN THE WAY OF SNFL FROM REACHING THE
GROUND EVEN TO THE DOWNEAST COAST. OUR BEST ESTIMATION IS THAT THE
OUTER ISLANDS AND ALG THE IMMEDIATE COAST OF SW COASTAL HANCOCK
COUNTY MAY BE EXPERIENCING LGT SN ATTM. THE FACT THAT MOST OF
COASTAL HANCOCK COUNTY HAS NOT RECEIVED MEASURABLE SN SINCE LATE
LATE NGT AND FCST RADAR REF BY THE HRRR MODEL BARELY BRUSHES
COASTAL DOWNEAST ME INTO THE OVRNGT HAS ALLOWED US TO DROP THE
REMAINING PTN OF THE SN ADV. ANY ACCUMULATING SNFL...MSLY THIS EVE
WILL BE LMTD TO THE COAST AND WILL MSLY AMT TO AN INCH OR LESS
WITH UP TO 2 INCHES OR SO OVR THE OUTER ISLANDS...WITH ANY STEADY
LGT SNFL MOVG SE OF THE COAST LATE TNGT.
OTHERWISE...SKIES WILL BEGIN CLR OVR THE N AND PTLY TO MSLY CLDY
CNTRL PTNS OF THE FA THIS EVE. A WEAK S/WV FROM CNTRL QB COULD
BEING CLDNSS BACK TO NRN ME LATE TNGT AS IT CROSSES JUST N OF THE
REGION. FOR THIS REASON...IT WILL BE ANOTHER TRICKY NGT FOR FCST
LOW TEMPS. EVEN SO...925MB TEMPS LATE TNGT WILL BE A LITTLE WARMER
THAN LAST NGTS...SO EVEN UNDER MCLR SKIES ALL NGT...OVRNGT LOWS
SHOULD NOT BE AS COLD...AND OF COURSE...ANY ADDITIONAL LOWER CLD
CVR LATE TNGT WILL EVEN ADD A FEW DEG F TO LOWS.
BEHIND THE NRN BRANCH S/WV...A MDT RE-SURGENCE OF ARCTIC AIR FROM
NRN QB MOVES SE INTO THE REGION FROM NRN QB LATE TUE INTO TUE NGT
WHICH AFT MILDER HI TEMPS TUE WILL RESULT IN ANOTHER COLD OVRNGT
LOW TUES NGT...PERHAPS COLDER THAN WHAT WE SHOW THIS UPDATE.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
DRY AND UNSEASONABLY COLD WILL CONTINUE WEDNESDAY AND WEDNESDAY
NIGHT AS HIGH PRESSURE REMAINS TO OUR NORTH. HIGHS TEMPERATURES
WEDNESDAY WILL BE IN THE SINGLE DIGITS ABOVE ZERO AND 10 TO 15
ABOVE ACROSS CENTRAL AND DOWN EAST AREAS. LOWS WEDNESDAY NIGHT
COULD BE TRICKY WITH INCREASING CLOUDS EXPECTED WEDNESDAY NIGHT.
THE COLDEST TEMPERATURES ARE EXPECTED ACROSS THE EASTERN AREAS
WHERE LOWS MAY GET DOWN TO AS COLD AS 10 BELOW IF CLOUDS HOLD OFF
LONG ENOUGH. A CLIPPER TYPE LOW WILL APPROACH FROM THE WEST ON
THURSDAY AND THEN REDEVELOP EAST OF THE NJ COAST LATER THURSDAY
AFTERNOON. WE COULD SEE A LITTLE LIGHT SNOW MOVING INTO THE AREA
LATE THURSDAY AFTERNOON BUT ANY SNOW ACCUMULATIONS IF ANY WILL BE
LIGHT. HIGHS ON THURSDAY WILL BE A FEW DEGREES WARMER BUT STILL
CONTINUED WELL BELOW NORMAL FOR THIS TIME OF YEAR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
LOW PRESSURE WILL LIKELY PASS TOO FAR TO OUR SOUTH THURSDAY NIGHT
AND FRIDAY TO BRING MUCH IN THE WAY OF SNOW ACCUMULATION TO THE
AREA. THE EXCEPTION COULD BE FOR PORTIONS OF WASHINGTON COUNTY
WHERE SEVERAL INCHES OF SNOW COULD ACCUMULATE. ANY SNOW WILL WIND
DOWN LATER FRIDAY AND GIVE WAY TO PARTIAL CLEARING FRIDAY NIGHT
AND SATURDAY. ANOTHER COASTAL LOW COULD BRING MORE SNOW TO THE
REGION LATE IN THE WEEKEND AND EARLY NEXT WEEK. TEMPERATURES WILL
REMAIN BELOW NORMAL THROUGH THE LONG TERM PERIOD.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
NEAR TERM: VFR ALL SITES THRU TUE NGT...XCPT MVFR CLGS/VSBYS
POSSIBLE WITH LGT SNFL AT KBHB UNTIL LATE TNGT.
SHORT TERM: VFR WEDNESDAY THROUGH THURSDAY. MVFR/IFR IS POSSIBLE
IN -SN THURSDAY NIGHT AND FRIDAY. VFR WILL RETURN FRIDAY NIGHT
THROUGH SATURDAY NIGHT. IFR POSSIBLE IN SN ON SUNDAY.
&&
.MARINE...
NEAR TERM: WILL CONT WITH AN SCA THRU THE LATE NGT...WITH WINDS
DROPPING BLO SCA LVL ON TUE...BEFORE INCREASING AGAIN BACK TO SCA
RANGE LATE TUE NGT. THE MIDNGT CREW CAN DETERMINE WHETHER TO KEEP
AN SCA UP FOR WED OR TO CHG FOR AN SCA FOR SEAS ON TUE.
OTHERWISE...SIMILAR TO WINDS...MDT FZGSPY WILL CONTINUE THRU THE
OVRNGT OVR THE INNER BAY/HARBOR MZ052...THEN BECOME LGT ON TUE AND
INCREASE AGAIN TO MDT BY LATE TUE NGT. CURRENT OBSVD WV HTS ARE
RUNNING A LITTLE ABV WW3 WV GUIDANCE...SO BEGAN THIS EVE ABOUT A
FOOT ABV THEN TRANSITIONED TO WW3 VALUES ON TUE.
SHORT TERM: WINDS/SEAS SHOULD REMAIN BELOW SMALL CRAFT LEVELS
THROUGH THURSDAY. WIND/SEAS MAY INCREASE TO SMALL CRAFT ADVISORY
LEVELS THURSDAY AND FRIDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR ANZ050>052.
FREEZING SPRAY ADVISORY UNTIL 5 AM EST TUESDAY FOR ANZ052.
&&
$$
NEAR TERM...VJN
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...VJN/DUDA
MARINE...VJN/DUDA
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
917 AM EST MON FEB 9 2015
.SYNOPSIS...
COLDER AIR WILL FILTER IN AS THE DAY PROGRESSES. CLOUDY CONDITIONS
WILL HOLD THROUGH TUESDAY BEFORE
&&
.NEAR TERM /THROUGH TONIGHT/...
9AM UPDATE...
COLD TEMPERATURES CONTINUE TO INVADE THE AREA...ESPECIALLY AREAS
NORTH AND WEST OF PGH. THIS COULD LEAD TO FREEZING OF ANY
REMAINING LIQUID THAT REMAINS ON ROADWAYS AND SIDEWALKS. ISSUED AN
SPS TO COVER THIS RE-FREEZE THREAT.
ELSEWHERE...THE SEEMINGLY INNOCUOUS ECHOES THAT EXISTED NEAR CMH
2-3HRS AGO HAVE BLOSSOMED AND ARE SPREADING LIGHT RAIN AND
FREEZING RAIN ACROSS ERN OH THE NRN PANHANDLE OF WV AND EXTREME SW PA.
THE LATEST HRRR HAS THIS PROGGED WELL AND WAS USED AS A BASELINE
FOR SHIFTING THIS PRECIPITATION EASTWARD THROUGH THE AFTERNOON.
ALSO FOLLOWING A BLEND OF THE LATEST HRRR TEMPS WITH THE PREVIOUS
FORECAST TO YIELD SFC TEMPS FAVORABLE OF MOSTLY RAIN FOR THIS
REMAINING PRECIPITATION. LIGHT FZRA OR SLEET IS MIXING ALONG THE BACK
EDGE...BUT THE RAP SHOWS MID-LEVEL MOISTURE QUICKLY SHUNTING EAST
OVER THE RIDGES BY AFTERNOON. STILL WITH FALLING TEMPERATURES AND
SFC TEMPS REACHING BELOW FREEZING BEFORE THE PRECIPITATION FULLY
DISSIPATES...A FREEZING RAIN ADVISORY WAS NECESSARY FOR A FEW HOURS.
TAX
PREVIOUS DISCUSSION...
TROUGH AXIS WILL PASS THROUGH TONIGHT. THE MAIN LIFT
WITH THE UPPER LEVEL WAVE MOVES THROUGH DURING THE EVENING
HOURS...EXITING THE RIDGES AFTER MIDNIGHT. THIS WOULD BE A GOOD
TIME TO SEE PATCHY FREEZING DRIZZLE. FREEZING DRIZZLE THAT DOES
DEVELOP WOULD HOLD ON LONGEST IN THE RIDGES.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
UPPER LEVEL RIDGE WILL MOVE INTO THE UPPER MIDWEST TUESDAY AND
THE COLD POOL ALOFT WILL MODIFY AS IT SINKS INTO NORTHERN WV.
STILL DOES NOT APPEAR THAT WE WILL BE ABLE TO GET RID OF THE LOW
CLOUD DECK AS MODEL SOUNDINGS CONTINUE TO SHOW SATURATION AT
AROUND 1000FT THROUGH TUESDAY. THIS WILL HELP TO HOLD TEMPS DOWN
AS WELL.
WARM ADVECTION WEDNESDAY...AHEAD OF THE NEXT SYSTEM MOVING THROUGH
THE GREAT LAKES. EVEN WITH THE WAA...MODELS STILL WANT TO HOLD
ONTO LOW CLOUD DECK. DON`T HAVE A LOT OF CONFIDENCE WITH THIS
SCENARIO SO WILL CONTINUE WITH PREVIOUS THINKING OF DECREASING
CLOUD COVER.
FOR THE MOST PART....WEDNESDAY LOOKS DRY. COULD SEE A RAIN OR SNOW
SHOWER SNEAK INTO THE NORTHERN HALF OF THE AREA LATE IN THE DAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
COLD AIR IS PROJECTED TO REMAIN OVER THE REGION THROUGH THE WEEKEND
AS A BROAD...HIGH AMPLITUDE UPPER TROUGH IS MODEL DEVELOPED OVER
EASTERN NORTH AMERICA.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
CURRENT THINKING IS THAT TAFS WILL STAY IFR OR LOWER THE ENTIRE
PERIOD. QUESTION IN THE NEAR TERM WILL BE HOW LONG IT TAKES SOME
SITES TO LIFT OUT OF LIFR CONDITIONS. LOTS OF MOISTURE REMAINS IN
THE ATMOSPHERE DUE TO MELTING SNOWPACK...BUT VISIBILITIES IN OHIO
HAVE BEEN ON THE RISE ONCE TEMPERATURES FALL BELOW FREEZING. THINK
THAT FKL/DUJ/BVI MAY STAY LIFR THROUGH THE TAF PERIOD...WITH THE
REST OF THE TERMINALS RETURNING TO IFR CONDITIONS BY THE
AFTERNOON. FREEZING DRIZZLE CANNOT BE RULED OUT. ZANESVILLE COULD
HAVE SOME THIS MORNING...AND THE MOST LIKELY PERIOD FOR THE REST
OF THE FORECAST AREA COMING THIS EVENING. NOT ENOUGH CONFIDENCE TO
INCLUDE IN TAFS AT THIS TIME.
OUTLOOK.../TUESDAY THROUGH FRIDAY/...
PERIODIC RESTRICTIONS WILL PLAGUE THE REGION THIS WEEK AS LOW
LEVEL MOISTURE LINGERS AND AS A STRONG COLD FRONT PASSES DURING
MID WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR OHZ058-059-068-
069.
PA...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR PAZ029.
WV...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR WVZ002>004.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
836 AM EST MON FEB 9 2015
.SYNOPSIS...
COLDER AIR WILL FILTER IN AS THE DAY PROGRESSES. CLOUDY CONDITIONS
WILL HOLD THROUGH TUESDAY BEFORE
&&
.NEAR TERM /THROUGH TONIGHT/...
8AM UPDATE...
ISSUED THE EXPIRATION OF THE FZRA ADVISORY WITH PRECIPITATION
MOVING OUT OF THE ADVISED AREA. COLD TEMPERATURES CONTINUE TO
INVADE THE AREA...ESPECIALLY AREAS NORTH AND WEST OF PGH. THIS
COULD LEAD TO FREEZING OF ANY REMAINING LIQUID THAT REMAINS ON
ROADWAYS AND SIDEWALKS. ISSUED AN SPS TO COVER THIS RE-FREEZE
THREAT.
ELSEWHERE...THE SEEMINGLY INNOCUOUS ECHOES THAT EXISTED NEAR CMH
1-2HRS AGO HAVE BLOSSOMED AND ARE SPREADING LIGHT RAIN AND A MIX
ACROSS OUR SOUTH. THE LATEST HRRR HAS THIS PROGGED WELL AND WAS
USED AS A BASELINE FOR SHIFTING THIS PRECIPITATION EASTWARD
THROUGH THE AFTERNOON. ALSO FOLLOWING A BLEND OF THE LATEST HRRR
TEMPS WITH THE PREVIOUS FORECAST TO YIELD SFC TEMPS FAVORABLE OF
MOSTLY RAIN FOR THIS REMAINING PRECIPITATION. LIGHT FZRA OR SLEET
COULD MIX ACROSS THE BACK EDGE...BUT THE RAP SHOWS MID-LEVEL
MOISTURE QUICKLY SHUNTING EAST OVER THE RIDGES BY AFTERNOON. THE
MIXING OF FZRA/SLEET IS EXPECTED ALONG THE DRYING BACK EDGE...AND
ANY MIXED PRECIP SHOULD REMAIN VERY LIGHT. DONT EXPECT THE NEED
FOR ADDITIONAL ADVISORIES AT THIS TIME.
TAX
PREVIOUS DISCUSSION...
TROUGH AXIS WILL PASS THROUGH TONIGHT. THE MAIN LIFT
WITH THE UPPER LEVEL WAVE MOVES THROUGH DURING THE EVENING
HOURS...EXITING THE RIDGES AFTER MIDNIGHT. THIS WOULD BE A GOOD
TIME TO SEE PATCHY FREEZING DRIZZLE. FREEZING DRIZZLE THAT DOES
DEVELOP WOULD HOLD ON LONGEST IN THE RIDGES.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
UPPER LEVEL RIDGE WILL MOVE INTO THE UPPER MIDWEST TUESDAY AND
THE COLD POOL ALOFT WILL MODIFY AS IT SINKS INTO NORTHERN WV.
STILL DOES NOT APPEAR THAT WE WILL BE ABLE TO GET RID OF THE LOW
CLOUD DECK AS MODEL SOUNDINGS CONTINUE TO SHOW SATURATION AT
AROUND 1000FT THROUGH TUESDAY. THIS WILL HELP TO HOLD TEMPS DOWN
AS WELL.
WARM ADVECTION WEDNESDAY...AHEAD OF THE NEXT SYSTEM MOVING THROUGH
THE GREAT LAKES. EVEN WITH THE WAA...MODELS STILL WANT TO HOLD
ONTO LOW CLOUD DECK. DON`T HAVE A LOT OF CONFIDENCE WITH THIS
SCENARIO SO WILL CONTINUE WITH PREVIOUS THINKING OF DECREASING
CLOUD COVER.
FOR THE MOST PART....WEDNESDAY LOOKS DRY. COULD SEE A RAIN OR SNOW
SHOWER SNEAK INTO THE NORTHERN HALF OF THE AREA LATE IN THE DAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
COLD AIR IS PROJECTED TO REMAIN OVER THE REGION THROUGH THE WEEKEND
AS A BROAD...HIGH AMPLITUDE UPPER TROUGH IS MODEL DEVELOPED OVER
EASTERN NORTH AMERICA.
&&
.AVIATION /13Z MONDAY THROUGH FRIDAY/...
CURRENT THINKING IS THAT TAFS WILL STAY IFR OR LOWER THE ENTIRE
PERIOD. QUESTION IN THE NEAR TERM WILL BE HOW LONG IT TAKES SOME
SITES TO LIFT OUT OF LIFR CONDITIONS. LOTS OF MOISTURE REMAINS IN
THE ATMOSPHERE DUE TO MELTING SNOWPACK...BUT VISIBILITIES IN OHIO
HAVE BEEN ON THE RISE ONCE TEMPERATURES FALL BELOW FREEZING. THINK
THAT FKL/DUJ/BVI MAY STAY LIFR THROUGH THE TAF PERIOD...WITH THE
REST OF THE TERMINALS RETURNING TO IFR CONDITIONS BY THE
AFTERNOON. FREEZING DRIZZLE CANNOT BE RULED OUT. ZANESVILLE COULD
HAVE SOME THIS MORNING...AND THE MOST LIKELY PERIOD FOR THE REST
OF THE FORECAST AREA COMING THIS EVENING. NOT ENOUGH CONFIDENCE TO
INCLUDE IN TAFS AT THIS TIME.
OUTLOOK.../TUESDAY THROUGH FRIDAY/...
PERIODIC RESTRICTIONS WILL PLAGUE THE REGION THIS WEEK AS LOW
LEVEL MOISTURE LINGERS AND AS A STRONG COLD FRONT PASSES DURING
MID WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
946 PM EST TUE FEB 10 2015
.UPDATE...
ISSUED AT 945 PM EST TUE FEB 10 2015
FCST NOT QUITE GOING AS PLANNED AS IT LOOKS LIKE SNOWFALL AMOUNTS
ARE GOING TO FALL SHORT OF ADVY CRITERIA BASED ON RADAR IMAGERY/OBS
AND TRENDS. HAVE CUT SNOW AMOUNTS DOWN TO MOSTLY 1-2 INCHES FOR THE
TONIGHT PERIOD...NOT ADVY WORTHY AMOUNTS. A FEW SPOTS MAY REACH 3.
THOSE HIGHER AMOUNTS MAY BE FOUND OVER THE KEWEENAW AND PERHAPS SOME
PORTIONS OF SCNTRL UPPER MI...CLOSER TO VORT MAX AND MORE
CONSOLIDATED SNOW AREA MOVING ACROSS WI. BIGGER CHANGE WAS TO ADD
-FZDZ INTO THE FCST BASED LARGELY ON UPSTREAM OBS...BUT ALSO BASED
ON SOME HINTS IN FCST SOUNDINGS THAT THERE WILL BE A LOSS OF ICE
CRYSTALS. WILL LET ADVY PLAY OUT WITH THE INTRODUCTION OF
-FZDZ. THAT SAID...SINCE IT WILL HAVE SNOWED BEFORE -FZDZ
OCCURS...IMPACT OF THE -FZDZ ON ROADWAYS WILL LIKELY BE MUCH MORE
LIMITED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 353 PM EST TUE FEB 10 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A POLAR BRANCH WNW
FLOW ALOFT OVER THE UPPER GREAT LKS BTWN AN ARCTIC BRANCH FARTHER N
IN CANADA AND A SUBTROPICAL BRANCH OVER THE SRN CONUS. SHRTWV
EMBEDDED IN THIS POLAR BRANCH FLOW IS MOVING ESE TOWARD WRN MN...
CAUSING 12HR H3 HGT FALLS UP TO 120M. ACCOMPANYING AREA OF PCPN IS
OVER MN UNDER AREA OF DEEPER MSTR ENHANCED BY UPR DVGC AHEAD OF THIS
FEATURE AS WELL AS WAA/ISENTROPIC ASCENT BEST SHOWN ON THE 290-300K
SFCS /ABOUT H6-75/ AND SPREADING TO THE NE TOWARD THE WRN CWA.
AHEAD OF THIS PCPN...SKIES OVER UPR MI ARE MAINLY CLDY WITH MOIST
LLVL AIRMASS TRAPPED UNDER SHARP INVRN BASE ARND H9. THERE HAS BEEN
SOME PATCHY LIGHT FREEZING DZ IN AREAS OVER THE KEWEENAW/NCENTRAL
WHERE LLVL ESE FLOW UPSLOPES.
MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON SN AMOUNTS
ASSOCIATED WITH INCOMING SHRTWV AND GOING HEADLINES.
LATE TODAY/TNGT...AS AREA OF ISENTROPIC ASCENT/UPR DVGC/DEEP LYR
QVECTOR CNVGC IN ADVANCE OF SHRTWV MOVING THRU MN PUSHES INTO THE
CWA...EXPECT SN TO OVERSPREAD THE AREA W-E. MODELS ARE INDICATING
A 9-12 HR PERIOD OF FORCING BEFORE THE ARRIVAL OF SOME DEEP LYR
QVECTOR DVGC/DNVA OVER THE W LATE IN THE WAKE OF THE SHRTWV/SFC LO
MOVING OVER CENTRAL UPR MI/NRN LK SUP BY 12Z WED. BUT SOME LINGERING
DRY AIR JUST ABOVE THE INVRN BASE WL HINDER THE DEVELOPMENT OF
STEADIER PCPN...ESPECIALLY IN AREAS THAT EXPERIENCE A DOWNSLOPE
WIND COMPONENT WITH ONGOING S FLOW...SO THE ACTUAL WINDOW FOR
STEADIER SN WL ACTUALLY BE 6-9 HRS. MODELS INDICATE ABOUT 2.5 G/KG
SPECIFIC HUMIDITY WL BE PRESENT ON THE 290K SFC ARND H7...WHICH
WOULD SUPPORT GOING FCST UP 3 TO 4 INCHES OF SNOW DURING THE 6-9 HR
WINDOW OF STEADY PCPN. ABSENCE OF ANY PHASING WITH THE ARCTIC/
SUBTROPICAL BRANCES AND SHARPER UPR DVGC ASSOCIATED WITH THE JET
CORES IN THOSE BRANCHES AS WELL AS FCST HI THIN DGZ THAT WL LIMIT
SN/WATER RATIOS WL LIMIT SN TOTALS. LATE TNGT...EXPECT THE PCPN OVER
THE W TO DIMINISH FOR AT LEAST A TIME FOLLOWING THE EXIT OF THE DEEP
UPR FORCING AND PASSAGE OF LO PRES TROF ACCOMPANYING SFC LO MOVING
THRU NRN LK SUP. THE INCOMING AIRMASS WL BE INITIALLY TOO WARM TO
SUPPORT LES. GOING HEADLINES APPEAR TO BE IN GOOD SHAPE. DID ADD
LUCE COUNTY TO THE HEADLINE MIX WITH ARND 3 INCHES EXPECTED THERE
BEFORE THE SN DIMINISHES LATER ON WED MRNG.
WED...LINGERING STEADY SN OVER THE ERN CWA SHOULD END IN THE MRNG
WITH THE PASSAGE OF SHRTWV/ACCOMPANYING SFC LO PRES TROF AND EXIT OF
DEEP LYR QVECTOR CNVGC. GUIDANCE THEN SHOWS AN ARCTIC BRANCH SHRTWV
DIGGING SHARPLY TO NEAR WRN LK SUP BY 00Z THU...WITH H85 TEMPS
FALLING TOWARD -21C OVER THE NW CWA BY 00Z THU FOLLOWING ATTENDANT
COLD FROPA. NNW H925 WINDS INCRSG UP TO 30-35KTS IN THE SHARP CYC
FLOW LEFT IN THE WAKE OF THIS DISTURBANCE AND DEEPENING LO PRES
EXITING TO THE E IN THE STRONG CAA WL RESULT IN VERY GUSTY SFC WINDS
THAT WL AT LEAST APRCH ADVY LEVELS AS WELL AS CONSIDERABLE BLSN IN
ADDITION TO THE LES IN EXPOSED AREAS NEAR LK SUP. THE COMBINATION OF
THE SHARP CYC FLOW AS WELL AS SOME DPVA/DEEP LYR QVECTOR CNVGC/
DEEPENING MSTR WITH THE STRONG CAD MAY BRING A PERIOD OF SOME LK
ENHANCED SN LATE IN THE DAY OVER THE W. LATER SHIFTS WL
NEED TO INCLUDE ADDITIONAL HEADLINES FOR AT LEAST AREAS NEAR LK SUP
FOR LATER WED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 348 PM EST TUE FEB 10 2015
STEADY N TO NNE WINDS WILL ALREADY BE SET UP AT 00Z THURSDAY...WITH
THE SFC LOW OVER NE LAKE HURON. MUCH OF WEDNESDAY NIGHT WILL BE
MARKED BY STRONG WINDS WITH GUSTS ON THE ORDER OF 30-40KTS. THERE IS
A POCKET OF 35-40KT WINDS BETWEEN 925 AND 800MB FROM 00Z-12Z
THURSDAY. THERE WILL DEFINETLY BE A NON-DIURNAL TREND TO THE WINDS.
WINDS WILL REMAIN OUT OF THE N THROUGH 12Z SUNDAY...ALTHOUGH WEAKEN
SIGNIFICANTLY LATE SATURDAY NIGHT/EARLY SUNDAY MONRING. IT WILL BE
AN EXTENDED PERIOD OF LAKE EFFECT SNOW SHOWERS...THAT WHEN
ACCOMPANIED WITH THE WIND AND THE SNOW ALREADY ON THE GROUND...WILL
RESULT IN SHARPLY REDUCED VISIBILITIES. HEADLINES WILL EVENTUALLY BE
POSTED FOR THIS PERIOD TO NOT ONLY HIGHLIGHT THE 2-4IN OF SNOW FROM
WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT...BUT THE BLOWING SNOW
SHARPLY REDUCING VIS. WILL CONTINUE TO HIGHLIGHT THIS PERIOD IN THE
HWO...WITH THE MAIN FOCUS OF THE SNOW AND BLOWING SNOW BEING ALONG
LAKE SUPERIOR...AND MAINLY FROM THE HURON MOUNTAINS THROUGH MUNISING
AND GRAND MARIAS.
BY DAYBREAK THURSDAY THE SFC WILL HAVE SHIFTED TO NY AND THE STRONG
1048-1052MB/30.9IN HIGH WILL HAVE SLIPPED INTO THE DAKOTAS. THE
PRESSURE GRADIENT WILL WEAKEN DURING THE AFTERNOON HOURS AS THE HIGH
WEAKENS SLIGHTLY ACROSS IA.
EXPECT THE SFC RIDGE TO EXTEND DIRECTLY OVER THE CWA 00-06Z
FRIDAY...BRINGING THE LIGHTEST WINDS OF THE PERIOD AND SHIFTING
LINGERING LES OVER E ALGER AND SCHOOLCRAFT/W LUCE COUNTIES FROM LATE
AFTERNOON THROUGH THE EVENING HOURS. OFFSHORE WINDS WILL TAKE HOLD
ACROSS ALL OF N UPPER MI BY 12Z FRIDAY.
QUICK ON THE HEALS OF THIS PAST SYSTEM...THE NEXT SFC LOW OVER THE W
HALF OF ONTARIO AT 12Z FRIDAY SHOULD CROSS N/CENTRAL LAKE SUPERIOR
BY MID DAY...AND DEEPEN OVER E LAKE SUPERIOR/UPPER MI BY 00Z
SATURDAY. A LIMITED PERIOD OF WAA WILL MEAN THAT 850MB TEMPS WILL
ONLY RISE TO AROUND -18C FRIDAY MORNING-EARLY AFTERNOON. AFTER THE
PASSAGE OF THE LOW LOOK FOR THE -20 TO -25C 850MB AIR TO FILTER BACK
IN. UNLIKE THE PAST COUPLE OF EVENTS...FREEZING DRIZZLE ON THE ONSET
WILL NOT BE A CONCERN.
NW WINDS WILL BE PICKING UP ACROSS THE W HALF OF UPPER MY BY AROUND
21Z...AND INCREASE ACROSS THE ENTIRE CWA OVERNIGHT TURNING FROM OUT
OF THE NW TO N AS THE SFC LOW EXITS ACROSS LAKE HURON AND THE COLD
AIR SETTLES IN WITH THE 500MB LOW OVER CENTRAL ONTARIO AT 06Z
SATURDAY SINKING OVER CENTRAL/E UPPER MI AROUND 12Z. -25 TO -35C AIR
WILL BE OVER THE W HALF BY 12Z SATURDAY /COLDEST OFF THE 10/12Z RUN
OF THE GFS/. EXPECT COLD AND BLUSTERY CONDITIONS LATE FRIDAY NIGHT
THROUGH SATURDAY!
AS PREVIOUSLY STATED...THE FIRST WAVE OF LAKE EFFECT AND STRONG
WINDS WEDNESDAY NIGHT AND THURSDAY WILL GIVE A GOOD FEEL TO WHAT
WILL HAPPEN FRIDAY NIGHT INTO SATURDAY. AT THIS POINT EXPECT
CONDITIONS TO BE WORSE THAN THE FIRST WAVE AND THERE WILL LIKELY BE
A PERIOD OF BLIZZARD CONDITIONS FOR THE FAVORED MARQUETTE-MUNISING
STRETCH AND PERSONS WILL LIKELY NEED TO PLAN FOR THE POSSIBILITY OF
M-28 BEING CLOSED.
WIND CHILL READINGS SATURDAY MORNING WILL FALL TO -15 TO -25F
SATURDAY MORNING AS THE STRONG WINDS COMBINE WITH LOWS AROUND 0F.
LOOK FOR SOME MODERATION TO THE VERY COLD AIR ALOFT SUNDAY...BUT
STILL AROUND -20 TO -25C THROUGH THE DAY SUNDAY. THERE IS SOME
DISCREPANCIES IN THE LOCAL WIND SHIFTS ACROSS LAKE SUPERIOR
SUNDAY...BUT THE TREND WILL BE IMPROVING CONDITIONS EITHER WAY AS
THE SFC HIGH SHIFTS OVERHEAD SUNDAY AND EXITS E SUNDAY
AFTERNOON/EVENING. THE NEXT GOOD CHANCE OF SNOW FOR LATE MONDAY
NIGHT/TUESDAY DOESN/T LOOK TOO IMPRESSIVE OFF THE ECMWF...BUT MORE
DYNAMIC OFF THE GFS. A BLENDED MODEL SOLUTION SEEMS REASONABLE AT
THIS POINT...AS THE MAIN CONCERS AND FOCUS FOR THIS FCST PERIOD ARE
RIGHT AT THE BEGINING AND THEN FRIDAY NIGHT THROUGH SATURDAY
MORNING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 652 PM EST TUE FEB 10 2015
AT KIWD...EXPECT MVFR CONDITIONS TO GENERALLY BE THE RULE TONIGHT
WITH DISTURBANCE PASSING ACROSS THE AREA. HEAVIER SNOW WILL OCCUR
THIS EVENING AND MAY LEAD TO OCNL IFR CONDITIONS. WINDS WILL SHIFT
TO THE W FOLLOWING THE PASSAGE OF A LOW PRES TROF EARLY ON WED
MORNING. COLD FROPA TOWARD 15Z WILL BRING STRONGER NW WINDS/LES AND
A RETURN OF IFR CONDITIONS. ARRIVAL OF ANOTHER SFC TROF LATE IN THE
AFTN WILL INCREASE LES AND RESULT IN LIFR CONDITIONS.
AT KCMX...EXPECT IFR/LIFR CONDITIONS TO PREVAIL THRU THE EVENING AS
STEADIER SNOW MOVES ACROSS THE AREA. THERE WILL LIKELY BE A BIT OF A
LULL LATER IN THE NIGHT WITH MVFR CONDITIONS...BUT WSHFT TO AN
UPSLOPE W DIRECTION AROUND 12Z FOLLOWING A LOW PRES TROF PASSAGE
SHOULD BRING A RETURN OF IFR CIGS. GUSTY NW WINDS AND LES/IFR
CONDITIONS WILL FOLLOW COLD FROPA BY LATE MORNING. ARRIVAL OF
ANOTHER SFC TROF IN THE AFTN WILL INCREASE LES/WINDS AND RESULT IN
LIFR CONDITIONS IN -SHSN/BLSN.
AT KSAW...EXPECT IFR CONDITIONS TO DEVELOP IN THE NEXT FEW HRS AS
-SN ARRIVES AND UPSLOPE S WIND CONTINUES. CONDITIONS ARE LIKELY TO
FALL TO LIFR FOR AT LEAST A TIME DURING THE NIGHT UNDER THE BAND OF
STEADY SN. ONCE THIS AREA OF PCPN EXITS BY 12Z...CONDITIONS SHOULD
RETURN TO MVFR WITH STRENGTHENING DOWNSLOPE W WIND VEERING NW
FOLLOWING LOW PRES TROF PASSAGE/COLD FROPA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 348 PM EST TUE FEB 10 2015
THE GALE WATCH FOR WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING WILL
BE UPGRADED TO A GALE WARNING. HEAVY FREEZING SPRAY WARNING WILL BE
NEEDED.
A RIDGE STRETCHING FROM JAMES BAY TO THE LOWER GREAT LAKES WILL
SHIFT E ACROSS QUEBEC TONIGHT. MEANWHILE...A TROUGH ACROSS THE UPPER
MS VALLEY WILL MOVE ACROSS LAKE SUPERIOR LATE TONIGHT AND WEDNESDAY
MORNING. THE LOW WILL CONTINUE E ACROSS THE LOWER GREAT LAKES
THROUGH WEDNESDAY NIGHT AS A TROUGH REMAINS ACROSS LOWER MI. A HIGH
ACROSS S CENTRAL CANADA WEDNESDAY WILL MOVE TO THE MID MS VALLEY ON
THURSDAY AND BUILD A RIDGE ACROSS LAKE SUPERIOR LATE THURSDAY INTO
THURSDAY NIGHT. IN BETWEEN THE EXITING LOW AND NEARING HIGH...N
GALES OF 35 TO 45 KNOTS ACROSS CENTRAL AND EASTERN LAKE SUPERIOR
LATE WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING.
LOOK FOR A LOW ACROSS MANITOBA THURSDAY NIGHT TO SINK ACROSS LAKE
SUPERIOR FRIDAY AFTERNOON AND EVENING...AND THE CENTRAL APPALACHIANS
SATURDAY AFTERNOON...WHILE A LARGE HIGH NEARS FROM SOUTH CENTRAL
CANADA AND THE NORTHERN PLAINS. THIS WILL BRING ABOUT ANOTHER ROUND
OF N GALES OF 35 TO 45 KNOTS AND HEAVY FREEZING SPRAY IS POSSIBLE
FRIDAY NIGHT THROUGH SATURDAY...MAINLY OVER CENTRAL AND EASTERN LAKE
SUPERIOR. EXPECT THE HIGH TO DRIFT ACROSS THE UPPER GREAT LAKES ON
SUNDAY...WITH MUCH LIGHTER WINDS TAKING HOLD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 7 AM EST /6 AM CST/ WEDNESDAY FOR
MIZ001-003>005-010-011-084.
WINTER WEATHER ADVISORY UNTIL 7 AM EST WEDNESDAY FOR MIZ006-013-
014-085.
WINTER WEATHER ADVISORY UNTIL 4 AM EST /3 AM CST/ WEDNESDAY FOR
MIZ002-009.
WINTER WEATHER ADVISORY FROM 1 AM TO 10 AM EST WEDNESDAY FOR
MIZ007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM WEDNESDAY TO 1 PM EST
THURSDAY FOR LSZ267.
GALE WARNING FROM 4 PM WEDNESDAY TO 1 PM EST THURSDAY FOR LSZ267.
HEAVY FREEZING SPRAY WARNING FROM 1 PM WEDNESDAY TO 7 PM EST
THURSDAY FOR LSZ266.
GALE WARNING FROM 1 PM WEDNESDAY TO 4 PM EST THURSDAY FOR LSZ266.
GALE WARNING FROM 1 PM WEDNESDAY TO 1 PM EST THURSDAY FOR LSZ265.
HEAVY FREEZING SPRAY WARNING FROM 1 PM WEDNESDAY TO 1 PM EST
THURSDAY FOR LSZ264.
GALE WARNING FROM 1 PM WEDNESDAY TO 10 AM EST THURSDAY FOR
LSZ264.
HEAVY FREEZING SPRAY WARNING FROM 1 PM WEDNESDAY TO 7 AM EST
THURSDAY FOR LSZ263.
GALE WARNING FROM 1 PM WEDNESDAY TO 7 AM EST THURSDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...ROLFSON
SHORT TERM...KC
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
654 PM EST TUE FEB 10 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 353 PM EST TUE FEB 10 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A POLAR BRANCH WNW
FLOW ALOFT OVER THE UPPER GREAT LKS BTWN AN ARCTIC BRANCH FARTHER N
IN CANADA AND A SUBTROPICAL BRANCH OVER THE SRN CONUS. SHRTWV
EMBEDDED IN THIS POLAR BRANCH FLOW IS MOVING ESE TOWARD WRN MN...
CAUSING 12HR H3 HGT FALLS UP TO 120M. ACCOMPANYING AREA OF PCPN IS
OVER MN UNDER AREA OF DEEPER MSTR ENHANCED BY UPR DVGC AHEAD OF THIS
FEATURE AS WELL AS WAA/ISENTROPIC ASCENT BEST SHOWN ON THE 290-300K
SFCS /ABOUT H6-75/ AND SPREADING TO THE NE TOWARD THE WRN CWA.
AHEAD OF THIS PCPN...SKIES OVER UPR MI ARE MAINLY CLDY WITH MOIST
LLVL AIRMASS TRAPPED UNDER SHARP INVRN BASE ARND H9. THERE HAS BEEN
SOME PATCHY LIGHT FREEZING DZ IN AREAS OVER THE KEWEENAW/NCENTRAL
WHERE LLVL ESE FLOW UPSLOPES.
MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON SN AMOUNTS
ASSOCIATED WITH INCOMING SHRTWV AND GOING HEADLINES.
LATE TODAY/TNGT...AS AREA OF ISENTROPIC ASCENT/UPR DVGC/DEEP LYR
QVECTOR CNVGC IN ADVANCE OF SHRTWV MOVING THRU MN PUSHES INTO THE
CWA...EXPECT SN TO OVERSPREAD THE AREA W-E. MODELS ARE INDICATING
A 9-12 HR PERIOD OF FORCING BEFORE THE ARRIVAL OF SOME DEEP LYR
QVECTOR DVGC/DNVA OVER THE W LATE IN THE WAKE OF THE SHRTWV/SFC LO
MOVING OVER CENTRAL UPR MI/NRN LK SUP BY 12Z WED. BUT SOME LINGERING
DRY AIR JUST ABOVE THE INVRN BASE WL HINDER THE DEVELOPMENT OF
STEADIER PCPN...ESPECIALLY IN AREAS THAT EXPERIENCE A DOWNSLOPE
WIND COMPONENT WITH ONGOING S FLOW...SO THE ACTUAL WINDOW FOR
STEADIER SN WL ACTUALLY BE 6-9 HRS. MODELS INDICATE ABOUT 2.5 G/KG
SPECIFIC HUMIDITY WL BE PRESENT ON THE 290K SFC ARND H7...WHICH
WOULD SUPPORT GOING FCST UP 3 TO 4 INCHES OF SNOW DURING THE 6-9 HR
WINDOW OF STEADY PCPN. ABSENCE OF ANY PHASING WITH THE ARCTIC/
SUBTROPICAL BRANCES AND SHARPER UPR DVGC ASSOCIATED WITH THE JET
CORES IN THOSE BRANCHES AS WELL AS FCST HI THIN DGZ THAT WL LIMIT
SN/WATER RATIOS WL LIMIT SN TOTALS. LATE TNGT...EXPECT THE PCPN OVER
THE W TO DIMINISH FOR AT LEAST A TIME FOLLOWING THE EXIT OF THE DEEP
UPR FORCING AND PASSAGE OF LO PRES TROF ACCOMPANYING SFC LO MOVING
THRU NRN LK SUP. THE INCOMING AIRMASS WL BE INITIALLY TOO WARM TO
SUPPORT LES. GOING HEADLINES APPEAR TO BE IN GOOD SHAPE. DID ADD
LUCE COUNTY TO THE HEADLINE MIX WITH ARND 3 INCHES EXPECTED THERE
BEFORE THE SN DIMINISHES LATER ON WED MRNG.
WED...LINGERING STEADY SN OVER THE ERN CWA SHOULD END IN THE MRNG
WITH THE PASSAGE OF SHRTWV/ACCOMPANYING SFC LO PRES TROF AND EXIT OF
DEEP LYR QVECTOR CNVGC. GUIDANCE THEN SHOWS AN ARCTIC BRANCH SHRTWV
DIGGING SHARPLY TO NEAR WRN LK SUP BY 00Z THU...WITH H85 TEMPS
FALLING TOWARD -21C OVER THE NW CWA BY 00Z THU FOLLOWING ATTENDANT
COLD FROPA. NNW H925 WINDS INCRSG UP TO 30-35KTS IN THE SHARP CYC
FLOW LEFT IN THE WAKE OF THIS DISTURBANCE AND DEEPENING LO PRES
EXITING TO THE E IN THE STRONG CAA WL RESULT IN VERY GUSTY SFC WINDS
THAT WL AT LEAST APRCH ADVY LEVELS AS WELL AS CONSIDERABLE BLSN IN
ADDITION TO THE LES IN EXPOSED AREAS NEAR LK SUP. THE COMBINATION OF
THE SHARP CYC FLOW AS WELL AS SOME DPVA/DEEP LYR QVECTOR CNVGC/
DEEPENING MSTR WITH THE STRONG CAD MAY BRING A PERIOD OF SOME LK
ENHANCED SN LATE IN THE DAY OVER THE W. LATER SHIFTS WL
NEED TO INCLUDE ADDITIONAL HEADLINES FOR AT LEAST AREAS NEAR LK SUP
FOR LATER WED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 348 PM EST TUE FEB 10 2015
STEADY N TO NNE WINDS WILL ALREADY BE SET UP AT 00Z THURSDAY...WITH
THE SFC LOW OVER NE LAKE HURON. MUCH OF WEDNESDAY NIGHT WILL BE
MARKED BY STRONG WINDS WITH GUSTS ON THE ORDER OF 30-40KTS. THERE IS
A POCKET OF 35-40KT WINDS BETWEEN 925 AND 800MB FROM 00Z-12Z
THURSDAY. THERE WILL DEFINETLY BE A NON-DIURNAL TREND TO THE WINDS.
WINDS WILL REMAIN OUT OF THE N THROUGH 12Z SUNDAY...ALTHOUGH WEAKEN
SIGNIFICANTLY LATE SATURDAY NIGHT/EARLY SUNDAY MONRING. IT WILL BE
AN EXTENDED PERIOD OF LAKE EFFECT SNOW SHOWERS...THAT WHEN
ACCOMPANIED WITH THE WIND AND THE SNOW ALREADY ON THE GROUND...WILL
RESULT IN SHARPLY REDUCED VISIBILITIES. HEADLINES WILL EVENTUALLY BE
POSTED FOR THIS PERIOD TO NOT ONLY HIGHLIGHT THE 2-4IN OF SNOW FROM
WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT...BUT THE BLOWING SNOW
SHARPLY REDUCING VIS. WILL CONTINUE TO HIGHLIGHT THIS PERIOD IN THE
HWO...WITH THE MAIN FOCUS OF THE SNOW AND BLOWING SNOW BEING ALONG
LAKE SUPERIOR...AND MAINLY FROM THE HURON MOUNTAINS THROUGH MUNISING
AND GRAND MARIAS.
BY DAYBREAK THURSDAY THE SFC WILL HAVE SHIFTED TO NY AND THE STRONG
1048-1052MB/30.9IN HIGH WILL HAVE SLIPPED INTO THE DAKOTAS. THE
PRESSURE GRADIENT WILL WEAKEN DURING THE AFTERNOON HOURS AS THE HIGH
WEAKENS SLIGHTLY ACROSS IA.
EXPECT THE SFC RIDGE TO EXTEND DIRECTLY OVER THE CWA 00-06Z
FRIDAY...BRINGING THE LIGHTEST WINDS OF THE PERIOD AND SHIFTING
LINGERING LES OVER E ALGER AND SCHOOLCRAFT/W LUCE COUNTIES FROM LATE
AFTERNOON THROUGH THE EVENING HOURS. OFFSHORE WINDS WILL TAKE HOLD
ACROSS ALL OF N UPPER MI BY 12Z FRIDAY.
QUICK ON THE HEALS OF THIS PAST SYSTEM...THE NEXT SFC LOW OVER THE W
HALF OF ONTARIO AT 12Z FRIDAY SHOULD CROSS N/CENTRAL LAKE SUPERIOR
BY MID DAY...AND DEEPEN OVER E LAKE SUPERIOR/UPPER MI BY 00Z
SATURDAY. A LIMITED PERIOD OF WAA WILL MEAN THAT 850MB TEMPS WILL
ONLY RISE TO AROUND -18C FRIDAY MORNING-EARLY AFTERNOON. AFTER THE
PASSAGE OF THE LOW LOOK FOR THE -20 TO -25C 850MB AIR TO FILTER BACK
IN. UNLIKE THE PAST COUPLE OF EVENTS...FREEZING DRIZZLE ON THE ONSET
WILL NOT BE A CONCERN.
NW WINDS WILL BE PICKING UP ACROSS THE W HALF OF UPPER MY BY AROUND
21Z...AND INCREASE ACROSS THE ENTIRE CWA OVERNIGHT TURNING FROM OUT
OF THE NW TO N AS THE SFC LOW EXITS ACROSS LAKE HURON AND THE COLD
AIR SETTLES IN WITH THE 500MB LOW OVER CENTRAL ONTARIO AT 06Z
SATURDAY SINKING OVER CENTRAL/E UPPER MI AROUND 12Z. -25 TO -35C AIR
WILL BE OVER THE W HALF BY 12Z SATURDAY /COLDEST OFF THE 10/12Z RUN
OF THE GFS/. EXPECT COLD AND BLUSTERY CONDITIONS LATE FRIDAY NIGHT
THROUGH SATURDAY!
AS PREVIOUSLY STATED...THE FIRST WAVE OF LAKE EFFECT AND STRONG
WINDS WEDNESDAY NIGHT AND THURSDAY WILL GIVE A GOOD FEEL TO WHAT
WILL HAPPEN FRIDAY NIGHT INTO SATURDAY. AT THIS POINT EXPECT
CONDITIONS TO BE WORSE THAN THE FIRST WAVE AND THERE WILL LIKELY BE
A PERIOD OF BLIZZARD CONDITIONS FOR THE FAVORED MARQUETTE-MUNISING
STRETCH AND PERSONS WILL LIKELY NEED TO PLAN FOR THE POSSIBILITY OF
M-28 BEING CLOSED.
WIND CHILL READINGS SATURDAY MORNING WILL FALL TO -15 TO -25F
SATURDAY MORNING AS THE STRONG WINDS COMBINE WITH LOWS AROUND 0F.
LOOK FOR SOME MODERATION TO THE VERY COLD AIR ALOFT SUNDAY...BUT
STILL AROUND -20 TO -25C THROUGH THE DAY SUNDAY. THERE IS SOME
DISCREPANCIES IN THE LOCAL WIND SHIFTS ACROSS LAKE SUPERIOR
SUNDAY...BUT THE TREND WILL BE IMPROVING CONDITIONS EITHER WAY AS
THE SFC HIGH SHIFTS OVERHEAD SUNDAY AND EXITS E SUNDAY
AFTERNOON/EVENING. THE NEXT GOOD CHANCE OF SNOW FOR LATE MONDAY
NIGHT/TUESDAY DOESN/T LOOK TOO IMPRESSIVE OFF THE ECMWF...BUT MORE
DYNAMIC OFF THE GFS. A BLENDED MODEL SOLUTION SEEMS REASONABLE AT
THIS POINT...AS THE MAIN CONCERS AND FOCUS FOR THIS FCST PERIOD ARE
RIGHT AT THE BEGINING AND THEN FRIDAY NIGHT THROUGH SATURDAY
MORNING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 652 PM EST TUE FEB 10 2015
AT KIWD...EXPECT MVFR CONDITIONS TO GENERALLY BE THE RULE TONIGHT
WITH DISTURBANCE PASSING ACROSS THE AREA. HEAVIER SNOW WILL OCCUR
THIS EVENING AND MAY LEAD TO OCNL IFR CONDITIONS. WINDS WILL SHIFT
TO THE W FOLLOWING THE PASSAGE OF A LOW PRES TROF EARLY ON WED
MORNING. COLD FROPA TOWARD 15Z WILL BRING STRONGER NW WINDS/LES AND
A RETURN OF IFR CONDITIONS. ARRIVAL OF ANOTHER SFC TROF LATE IN THE
AFTN WILL INCREASE LES AND RESULT IN LIFR CONDITIONS.
AT KCMX...EXPECT IFR/LIFR CONDITIONS TO PREVAIL THRU THE EVENING AS
STEADIER SNOW MOVES ACROSS THE AREA. THERE WILL LIKELY BE A BIT OF A
LULL LATER IN THE NIGHT WITH MVFR CONDITIONS...BUT WSHFT TO AN
UPSLOPE W DIRECTION AROUND 12Z FOLLOWING A LOW PRES TROF PASSAGE
SHOULD BRING A RETURN OF IFR CIGS. GUSTY NW WINDS AND LES/IFR
CONDITIONS WILL FOLLOW COLD FROPA BY LATE MORNING. ARRIVAL OF
ANOTHER SFC TROF IN THE AFTN WILL INCREASE LES/WINDS AND RESULT IN
LIFR CONDITIONS IN -SHSN/BLSN.
AT KSAW...EXPECT IFR CONDITIONS TO DEVELOP IN THE NEXT FEW HRS AS
-SN ARRIVES AND UPSLOPE S WIND CONTINUES. CONDITIONS ARE LIKELY TO
FALL TO LIFR FOR AT LEAST A TIME DURING THE NIGHT UNDER THE BAND OF
STEADY SN. ONCE THIS AREA OF PCPN EXITS BY 12Z...CONDITIONS SHOULD
RETURN TO MVFR WITH STRENGTHENING DOWNSLOPE W WIND VEERING NW
FOLLOWING LOW PRES TROF PASSAGE/COLD FROPA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 348 PM EST TUE FEB 10 2015
THE GALE WATCH FOR WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING WILL
BE UPGRADED TO A GALE WARNING. HEAVY FREEZING SPRAY WARNING WILL BE
NEEDED.
A RIDGE STRETCHING FROM JAMES BAY TO THE LOWER GREAT LAKES WILL
SHIFT E ACROSS QUEBEC TONIGHT. MEANWHILE...A TROUGH ACROSS THE UPPER
MS VALLEY WILL MOVE ACROSS LAKE SUPERIOR LATE TONIGHT AND WEDNESDAY
MORNING. THE LOW WILL CONTINUE E ACROSS THE LOWER GREAT LAKES
THROUGH WEDNESDAY NIGHT AS A TROUGH REMAINS ACROSS LOWER MI. A HIGH
ACROSS S CENTRAL CANADA WEDNESDAY WILL MOVE TO THE MID MS VALLEY ON
THURSDAY AND BUILD A RIDGE ACROSS LAKE SUPERIOR LATE THURSDAY INTO
THURSDAY NIGHT. IN BETWEEN THE EXITING LOW AND NEARING HIGH...N
GALES OF 35 TO 45 KNOTS ACROSS CENTRAL AND EASTERN LAKE SUPERIOR
LATE WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING.
LOOK FOR A LOW ACROSS MANITOBA THURSDAY NIGHT TO SINK ACROSS LAKE
SUPERIOR FRIDAY AFTERNOON AND EVENING...AND THE CENTRAL APPALACHIANS
SATURDAY AFTERNOON...WHILE A LARGE HIGH NEARS FROM SOUTH CENTRAL
CANADA AND THE NORTHERN PLAINS. THIS WILL BRING ABOUT ANOTHER ROUND
OF N GALES OF 35 TO 45 KNOTS AND HEAVY FREEZING SPRAY IS POSSIBLE
FRIDAY NIGHT THROUGH SATURDAY...MAINLY OVER CENTRAL AND EASTERN LAKE
SUPERIOR. EXPECT THE HIGH TO DRIFT ACROSS THE UPPER GREAT LAKES ON
SUNDAY...WITH MUCH LIGHTER WINDS TAKING HOLD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 7 AM EST /6 AM CST/ WEDNESDAY FOR
MIZ001-003>005-010-011-084.
WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 7 AM EST
WEDNESDAY FOR MIZ006-013-014-085.
WINTER WEATHER ADVISORY UNTIL 4 AM EST /3 AM CST/ WEDNESDAY FOR
MIZ002-009.
WINTER WEATHER ADVISORY FROM 1 AM TO 10 AM EST WEDNESDAY FOR
MIZ007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM WEDNESDAY TO 1 PM EST
THURSDAY FOR LSZ267.
GALE WARNING FROM 4 PM WEDNESDAY TO 1 PM EST THURSDAY FOR LSZ267.
HEAVY FREEZING SPRAY WARNING FROM 1 PM WEDNESDAY TO 7 PM EST
THURSDAY FOR LSZ266.
GALE WARNING FROM 1 PM WEDNESDAY TO 4 PM EST THURSDAY FOR LSZ266.
GALE WARNING FROM 1 PM WEDNESDAY TO 1 PM EST THURSDAY FOR LSZ265.
HEAVY FREEZING SPRAY WARNING FROM 1 PM WEDNESDAY TO 1 PM EST
THURSDAY FOR LSZ264.
GALE WARNING FROM 1 PM WEDNESDAY TO 10 AM EST THURSDAY FOR
LSZ264.
HEAVY FREEZING SPRAY WARNING FROM 1 PM WEDNESDAY TO 7 AM EST
THURSDAY FOR LSZ263.
GALE WARNING FROM 1 PM WEDNESDAY TO 7 AM EST THURSDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
510 PM EST MON FEB 9 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 348 PM EST MON FEB 9 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT
OVER THE GREAT LKS BTWN AN UPR RDG OVER THE WRN PLAINS AND A TROF
ACROSS THE ERN CONUS. A SHRTWV EMBEDDED IN THIS NW FLOW AND
ACCOMPANYING AREA OF SOMEWHAT DEEPER MSTR/DYNAMIC FORCING THAT
LIFTED INVRN BASE UP TO ARND 4K FT AGL BROUGHT AN UPTICK THIS MRNG
TO THE LES IN THE PRESENCE OF INVRN BASE TEMPS ARND -12C OVER MAINLY
THE NCNTRL WHERE OBSVD N WINDS UPSLOPE. BUT DNVA/SUBSIDENCE IN THE
WAKE OF THE SHRTWV PASSAGE AND IN ADVANCE OF APRCHG SHRTWV RDG HAVE
CAUSED THE LES TO DIMINISH THIS AFTN...AND EVEN FOR THE LO CLDS TO
BREAK UP TO A CERTAIN EXTENT. SINCE THE 12Z INL/YPL ROABS TO THE NW
SHOW MSTR EXTENDING UP THRU ABOUT H7...PLENTY OF CLD COVER AND SOME
FLURRIES LINGER UPSTREAM IN NRN MN AND NW ONTARIO. LOOKING FARTHER
UPSTREAM...A FAIRLY VIGOROUS SHRTWV IS MOVING INTO THE PAC NW AND
OVER THE WRN RDG.
LATE TODAY/TNGT...ALTHOUGH THE LLVLS WL REMAIN COLD ENUF FOR LES...
LARGE SCALE SUBSIDENCE IN ADVANCE OF APRCHG SHRTWV RDG THAT DEPRESS
INVRN BASE TOWARD 2-3K FT WL LIMIT LES INTENSITY AND COVERAGE.
INITIALLY...LLVL LIGHT WINDS ARE FCST TO BACK TOWARD THE NW INTO
THIS EVNG AHEAD OF THE INCOMING SFC RDG. SO MOST OF THE LINGERING
LES/LK CLDS SHOULD BE TO THE E OF MQT AND OVER THE KEWEENAW THIS
EVNG. LIGHT WINDS ASSOCIATED WITH THE PASSING SFC RDG AXIS MAY ALLOW
FOR A MESOLO PRES TO DVLP. HOWEVER...PRESENCE OF A GOOD DEAL OF ICE
NEAR LK SUP E OF MARQUETTE WL LIMIT THE POTENTIAL IMPACT OF THIS
FEATURE IN THESE AREAS. AS THE WINDS TEND TO SHIFT BACK TO THE NE
LATER FOLLOWING THE PASSAGE OF THE RDG AXIS TO THE E...SOME LES
MIGHT SHIFT BACK TOWARD MARQUETTE. ANOTHER WEAK SHRTWV/AREA OF DEEP
LYR QVECTOR CNVGC IS FCST TO MOVE BY LATE TNGT. BUT SINCE SFC RDG
AXIS WL BE PASSING THRU AT THAT TIME...THE IMPACT SHOULD BE MINIMAL.
EXPECT THE LOWEST MIN TEMPS OVER THE E AND SCNTRL WHERE LIGHT E
WINDS WL DRAIN OFF SOME VERY COLD OVER ONTARIO AND MSTR/CLDS TO THE
NW WL HAVE A HARDER TIME REACHING.
TUE...LARGE SCALE WAA/DEEP LYR QVECTOR CNVGC/UPR DVGC IN INCRSG SSE
FLOW BTWN DEPARTING SFC HI PRES RDG TO THE E AND IN ADVANCE OF
SHRTWV NOW OVER THE PAC NW THAT WL BE MOVING THRU THE NRN PLAINS IS
FCST TO ARRIVE IN THE AFTN. THE ARRIVAL OF THIS FORCING AND
ACCOMPANYING UVV WL ALLOW FOR THICKENING CLDS AND SOME SN TO PUSH
INTO THE WRN COUNTIES DURING THE AFTN. H7 SPECIFIC HUMIDITY FCST UP
TO 3 G/KG UNDER THE AXIS OF WAA INDICATES A FEW INCHES OF SN MAY
ACCUMULATE OVER THE FAR W BY 00Z DESPITE A RATHER HI...NARROW DGZ.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 510 PM EST MON FEB 9 2015
BOUTS OF COLD AND SNOW WILL BE THE THEME FOR THE LONG TERM PERIOD.
SNOW WILL BE EXPANDING W TO E ACROSS THE CWA TUESDAY NIGHT AS THE
MAIN SFC LOW OVER S AND CENTRAL MN CROSSES FAR W BY 06Z...AND SPLITS
THE AREA IN HALF BY 12Z WEDNESDAY. 850MB TEMPS WILL FALL TO AROUND -
12C BEHIND THE LOW...WITH -20C AIR WEDNESDAY EVENING ON FAVORABLE
UPSLOPE FLOW.
CONTINUED TO MENTION THE POTENTIAL FOR WIDESPREAD SNOW TUESDAY
AFTERNOON THROUGH TUESDAY NIGHT WITH A FEW INCHES OF SNOW
ACCUMULATION POSSIBLE...THEN LAKE EFFECT SNOW WEDNESDAY INTO
THURSDAY. GUSTY NW TO N WINDS WILL HELP PRODUCE BLOWING SNOW AND
REDUCED VIS WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING. MAY NEED
TO ISSUE WINTER WX ADVISORY FOR THE 2-4.5IN OF SNOW TUESDAY THROUGH
DAYBREAK WEDNESDAY...AND DEPENDING ON THE FOCUS OF MODERATE LES FOR
SNOW AND BLOWING SNOW FOR THE LONGER DURATION LES FOR THE N WIND
FAVORED AREAS OF GOGEBIC/ONTONAGON AND BARAGA/MARQUETTE E ALONG LAKE
SUPERIOR AS 850MB TEMPS FALL TO AROUND -25C.
WITH ALL THIS COLD AIR...WIND CHILL VALUES ARE EXPECTED TO FALL
BETWEEN 15 BELOW AND 25 BELOW ZERO THURSDAY MORNING INLAND FROM THE
GREAT LAKES.
THE N WINDS WILL ALSO BE A CONCERN FOR LATE FRIDAY EVENING THROUGH
ALL OF SATURDAY...WITH THE BEST CHANCE OF LES N CENTRAL. DID BUMP UP
THE WINDS/GUSTS APPROX 5KTS SATURDAY MORNING. LOOKING AT IT FROM A
DIFFERENT PERSPECTIVE...THIS WIND SATURDAY WILL PROBABLY RESULT IN A
RESTRICTION OR ROAD CLOSURE OF M-28 EAST OF HARVEY THROUGH MUNISING
LATE FRIDAY NIGHT THROUGH SATURDAY MORNING...ESPECIALLY CONSIDERING
THE AMOUNT OF SNOW THAT WILL BE ABLE TO ACCUMULATE ON THE SNOW JUST
OFFSHORE. AS THIS IS STILL 4-5 DAYS OUT...LOOK FOR ADJUSTMENTS TO
THE ONGOING FCST. IMPROVING CONDITIONS WILL COME IN SATURDAY NIGHT
AS THE SFC LOW SINING ACROSS THE UPPER GREAT LAKES FRIDAY
AFTERNOON/EVENING PUSHES TO THE CENTRAL APPALACHIANS BY SATURDAY
AFTERNOON. VERY STRONG HIGH PRESSURE ACROSS S CANADA AND THE CENTRAL
PLAINS WILL THEN SLOWLY MOVE IN. THE SFC RIDGE WILL BE
DIRECTLY OVERHEAD SUNDAY MORNING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1236 PM EST MON FEB 9 2015
LLVL MSTR TRAPPED BLO A SUBSIDENCE INVRN WL CAUSE PREDOMINANT MVFR
CONDITIONS AT CMX THIS FCST PERIOD. ALTHOUGH LO CLDS/MVFR CIGS WL
DOMINATE SAW EARLY...EXPECT SOME VFR WX TO RETURN TO SAW LATE THIS
AFTN/EVNG AS THE LLVL WINDS BACK TO A DOWNSLOPE NW DIRECTION UNDER
LARGER SCALE SUBSIDENCE AHEAD OF AN APRCHG HI PRES RDG. BUT AS THE
SFC RDG PASSES TO THE E OF THE AREA...VEERING WINDS BACK TO THE NE
OVERNGT AND THEN THE SE ON TUE WL BRING A RETURN OF LO CLDS AND
POSSIBLY EVEN IFR CIGS ON TUE. AT IWD...MVFR CIGS WL LINGER INTO
THIS EVNG IN THE NW FLOW AHEAD OF APRCH SFC RDG. AS THE FLOW TURNS
TO A DOWNSLOPE SE DIRECTION TNGT...EXPECT VFR CONDITIONS AT THAT
SITE THRU TUE MRNG.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 349 PM EST MON FEB 9 2015
A COUPLE ROUNDS AND HEAVY FREEZING SPRAY ARE EXPECTED THIS PERIOD. A
RIDGE ACROSS LAKE SUPERIOR WILL SLOWLY ERODE TUESDAY...AS A LOW
NEARS FROM THE N PLAINS. EXPECT THE LOW TO CROSS THE UPPER GREAT
LAKE TUESDAY NIGHT AND WEDNESDAY...THE LOWER GREAT LAKES WEDNESDAY
NIGHT...AND EVENTUALLY END UP DEEPENING SIGNIFICANTLY OFF THE NEW
ENGLAND COAST THURSDAY NIGHT. THIS WILL BE WHILE A HIGH ACROSS S
CENTRAL CANADA WEDNESDAY MOVES TO THE MID MS VALLEY THURSDAY NIGHT
...AND BUILDS A RIDGE ACROSS LAKE SUPERIOR LATE THURSDAY INTO
THURSDAY NIGHT. A GALE WATCH HAS BEEN ISSUED FOR MUCH OF CENTRAL TO
E LAKE SUPERIOR WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING AS
MAINLY N WINDS INCREASE W/30-40KT GUSTS.
LOOK FOR A LOW ACROSS MANITOBA THURSDAY NIGHT TO SINK ACROSS THE
UPPER GREAT LAKES FRIDAY...AND INTO THE CENTRAL APPALACHIANS
SATURDAY AFTERNOON...WHILE LARGE HIGH PRESSURE NEARS FROM THE S
CENTRAL CANADA AND THE NORTHERN PLAINS. THIS WILL BRING ABOUT
ANOTHER PERIOD OF MAINLY N GALES OF 35-40KTS OVER MUCH OF LAKE
SUPERIOR FRIDAY EVENING THROUGH SATURDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON
FOR LSZ266-267.
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING FOR
LSZ265.
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING FOR
LSZ264.
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...- NONE -
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
354 PM EST MON FEB 9 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 348 PM EST MON FEB 9 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT
OVER THE GREAT LKS BTWN AN UPR RDG OVER THE WRN PLAINS AND A TROF
ACROSS THE ERN CONUS. A SHRTWV EMBEDDED IN THIS NW FLOW AND
ACCOMPANYING AREA OF SOMEWHAT DEEPER MSTR/DYNAMIC FORCING THAT
LIFTED INVRN BASE UP TO ARND 4K FT AGL BROUGHT AN UPTICK THIS MRNG
TO THE LES IN THE PRESENCE OF INVRN BASE TEMPS ARND -12C OVER MAINLY
THE NCNTRL WHERE OBSVD N WINDS UPSLOPE. BUT DNVA/SUBSIDENCE IN THE
WAKE OF THE SHRTWV PASSAGE AND IN ADVANCE OF APRCHG SHRTWV RDG HAVE
CAUSED THE LES TO DIMINISH THIS AFTN...AND EVEN FOR THE LO CLDS TO
BREAK UP TO A CERTAIN EXTENT. SINCE THE 12Z INL/YPL ROABS TO THE NW
SHOW MSTR EXTENDING UP THRU ABOUT H7...PLENTY OF CLD COVER AND SOME
FLURRIES LINGER UPSTREAM IN NRN MN AND NW ONTARIO. LOOKING FARTHER
UPSTREAM...A FAIRLY VIGOROUS SHRTWV IS MOVING INTO THE PAC NW AND
OVER THE WRN RDG.
LATE TODAY/TNGT...ALTHOUGH THE LLVLS WL REMAIN COLD ENUF FOR LES...
LARGE SCALE SUBSIDENCE IN ADVANCE OF APRCHG SHRTWV RDG THAT DEPRESS
INVRN BASE TOWARD 2-3K FT WL LIMIT LES INTENSITY AND COVERAGE.
INITIALLY...LLVL LIGHT WINDS ARE FCST TO BACK TOWARD THE NW INTO
THIS EVNG AHEAD OF THE INCOMING SFC RDG. SO MOST OF THE LINGERING
LES/LK CLDS SHOULD BE TO THE E OF MQT AND OVER THE KEWEENAW THIS
EVNG. LIGHT WINDS ASSOCIATED WITH THE PASSING SFC RDG AXIS MAY ALLOW
FOR A MESOLO PRES TO DVLP. HOWEVER...PRESENCE OF A GOOD DEAL OF ICE
NEAR LK SUP E OF MARQUETTE WL LIMIT THE POTENTIAL IMPACT OF THIS
FEATURE IN THESE AREAS. AS THE WINDS TEND TO SHIFT BACK TO THE NE
LATER FOLLOWING THE PASSAGE OF THE RDG AXIS TO THE E...SOME LES
MIGHT SHIFT BACK TOWARD MARQUETTE. ANOTHER WEAK SHRTWV/AREA OF DEEP
LYR QVECTOR CNVGC IS FCST TO MOVE BY LATE TNGT. BUT SINCE SFC RDG
AXIS WL BE PASSING THRU AT THAT TIME...THE IMPACT SHOULD BE MINIMAL.
EXPECT THE LOWEST MIN TEMPS OVER THE E AND SCNTRL WHERE LIGHT E
WINDS WL DRAIN OFF SOME VERY COLD OVER ONTARIO AND MSTR/CLDS TO THE
NW WL HAVE A HARDER TIME REACHING.
TUE...LARGE SCALE WAA/DEEP LYR QVECTOR CNVGC/UPR DVGC IN INCRSG SSE
FLOW BTWN DEPARTING SFC HI PRES RDG TO THE E AND IN ADVANCE OF
SHRTWV NOW OVER THE PAC NW THAT WL BE MOVING THRU THE NRN PLAINS IS
FCST TO ARRIVE IN THE AFTN. THE ARRIVAL OF THIS FORCING AND
ACCOMPANYING UVV WL ALLOW FOR THICKENING CLDS AND SOME SN TO PUSH
INTO THE WRN COUNTIES DURING THE AFTN. H7 SPECIFIC HUMIDITY FCST UP
TO 3 G/KG UNDER THE AXIS OF WAA INDICATES A FEW INCHES OF SN MAY
ACCUMULATE OVER THE FAR W BY 00Z DESPITE A RATHER HI...NARROW DGZ.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 349 PM EST MON FEB 9 2015
PRELIMINARY. THIS SECTION TO BE EXPANDED WITHIN THE NEXT HOUR.
BOUTS OF COLD AND SNOW WILL BE THE THEME FOR THE LONG TERM PERIOD.
LOOK FOR STRONG WINDS N CENTRAL ALONG LAKE SUPERIOR NOT ONLY FOR
WEDNESDAY AFTERNOON THROUGH AT LEAST THURSDAY MORNING...BUT ALSO FOR
LATE FRIDAY EVENING THROUGH ALL OF SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1236 PM EST MON FEB 9 2015
LLVL MSTR TRAPPED BLO A SUBSIDENCE INVRN WL CAUSE PREDOMINANT MVFR
CONDITIONS AT CMX THIS FCST PERIOD. ALTHOUGH LO CLDS/MVFR CIGS WL
DOMINATE SAW EARLY...EXPECT SOME VFR WX TO RETURN TO SAW LATE THIS
AFTN/EVNG AS THE LLVL WINDS BACK TO A DOWNSLOPE NW DIRECTION UNDER
LARGER SCALE SUBSIDENCE AHEAD OF AN APRCHG HI PRES RDG. BUT AS THE
SFC RDG PASSES TO THE E OF THE AREA...VEERING WINDS BACK TO THE NE
OVERNGT AND THEN THE SE ON TUE WL BRING A RETURN OF LO CLDS AND
POSSIBLY EVEN IFR CIGS ON TUE. AT IWD...MVFR CIGS WL LINGER INTO
THIS EVNG IN THE NW FLOW AHEAD OF APRCH SFC RDG. AS THE FLOW TURNS
TO A DOWNSLOPE SE DIRECTION TNGT...EXPECT VFR CONDITIONS AT THAT
SITE THRU TUE MRNG.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 349 PM EST MON FEB 9 2015
A COUPLE ROUNDS AND HEAVY FREEZING SPRAY ARE EXPECTED THIS PERIOD. A
RIDGE ACROSS LAKE SUPERIOR WILL SLOWLY ERODE TUESDAY...AS A LOW
NEARS FROM THE N PLAINS. EXPECT THE LOW TO CROSS THE UPPER GREAT
LAKE TUESDAY NIGHT AND WEDNESDAY...THE LOWER GREAT LAKES WEDNESDAY
NIGHT...AND EVENTUALLY END UP DEEPENING SIGNIFICANTLY OFF THE NEW
ENGLAND COAST THURSDAY NIGHT. THIS WILL BE WHILE A HIGH ACROSS S
CENTRAL CANADA WEDNESDAY MOVES TO THE MID MS VALLEY THURSDAY NIGHT
...AND BUILDS A RIDGE ACROSS LAKE SUPERIOR LATE THURSDAY INTO
THURSDAY NIGHT. A GALE WATCH HAS BEEN ISSUED FOR MUCH OF CENTRAL TO
E LAKE SUPERIOR WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING AS
MAINLY N WINDS INCREASE W/30-40KT GUSTS.
LOOK FOR A LOW ACROSS MANITOBA THURSDAY NIGHT TO SINK ACROSS THE
UPPER GREAT LAKES FRIDAY...AND INTO THE CENTRAL APPALACHIANS
SATURDAY AFTERNOON...WHILE LARGE HIGH PRESSURE NEARS FROM THE S
CENTRAL CANADA AND THE NORTHERN PLAINS. THIS WILL BRING ABOUT
ANOTHER PERIOD OF MAINLY N GALES OF 35-40KTS OVER MUCH OF LAKE
SUPERIOR FRIDAY EVENING THROUGH SATURDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON
FOR LSZ266-267.
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING FOR
LSZ265.
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING FOR
LSZ264.
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
348 PM EST MON FEB 9 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 348 PM EST MON FEB 9 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT
OVER THE GREAT LKS BTWN AN UPR RDG OVER THE WRN PLAINS AND A TROF
ACROSS THE ERN CONUS. A SHRTWV EMBEDDED IN THIS NW FLOW AND
ACCOMPANYING AREA OF SOMEWHAT DEEPER MSTR/DYNAMIC FORCING THAT
LIFTED INVRN BASE UP TO ARND 4K FT AGL BROUGHT AN UPTICK THIS MRNG
TO THE LES IN THE PRESENCE OF INVRN BASE TEMPS ARND -12C OVER MAINLY
THE NCNTRL WHERE OBSVD N WINDS UPSLOPE. BUT DNVA/SUBSIDENCE IN THE
WAKE OF THE SHRTWV PASSAGE AND IN ADVANCE OF APRCHG SHRTWV RDG HAVE
CAUSED THE LES TO DIMINISH THIS AFTN...AND EVEN FOR THE LO CLDS TO
BREAK UP TO A CERTAIN EXTENT. SINCE THE 12Z INL/YPL ROABS TO THE NW
SHOW MSTR EXTENDING UP THRU ABOUT H7...PLENTY OF CLD COVER AND SOME
FLURRIES LINGER UPSTREAM IN NRN MN AND NW ONTARIO. LOOKING FARTHER
UPSTREAM...A FAIRLY VIGOROUS SHRTWV IS MOVING INTO THE PAC NW AND
OVER THE WRN RDG.
LATE TODAY/TNGT...ALTHOUGH THE LLVLS WL REMAIN COLD ENUF FOR LES...
LARGE SCALE SUBSIDENCE IN ADVANCE OF APRCHG SHRTWV RDG THAT DEPRESS
INVRN BASE TOWARD 2-3K FT WL LIMIT LES INTENSITY AND COVERAGE.
INITIALLY...LLVL LIGHT WINDS ARE FCST TO BACK TOWARD THE NW INTO
THIS EVNG AHEAD OF THE INCOMING SFC RDG. SO MOST OF THE LINGERING
LES/LK CLDS SHOULD BE TO THE E OF MQT AND OVER THE KEWEENAW THIS
EVNG. LIGHT WINDS ASSOCIATED WITH THE PASSING SFC RDG AXIS MAY ALLOW
FOR A MESOLO PRES TO DVLP. HOWEVER...PRESENCE OF A GOOD DEAL OF ICE
NEAR LK SUP E OF MARQUETTE WL LIMIT THE POTENTIAL IMPACT OF THIS
FEATURE IN THESE AREAS. AS THE WINDS TEND TO SHIFT BACK TO THE NE
LATER FOLLOWING THE PASSAGE OF THE RDG AXIS TO THE E...SOME LES
MIGHT SHIFT BACK TOWARD MARQUETTE. ANOTHER WEAK SHRTWV/AREA OF DEEP
LYR QVECTOR CNVGC IS FCST TO MOVE BY LATE TNGT. BUT SINCE SFC RDG
AXIS WL BE PASSING THRU AT THAT TIME...THE IMPACT SHOULD BE MINIMAL.
EXPECT THE LOWEST MIN TEMPS OVER THE E AND SCNTRL WHERE LIGHT E
WINDS WL DRAIN OFF SOME VERY COLD OVER ONTARIO AND MSTR/CLDS TO THE
NW WL HAVE A HARDER TIME REACHING.
TUE...LARGE SCALE WAA/DEEP LYR QVECTOR CNVGC/UPR DVGC IN INCRSG SSE
FLOW BTWN DEPARTING SFC HI PRES RDG TO THE E AND IN ADVANCE OF
SHRTWV NOW OVER THE PAC NW THAT WL BE MOVING THRU THE NRN PLAINS IS
FCST TO ARRIVE IN THE AFTN. THE ARRIVAL OF THIS FORCING AND
ACCOMPANYING UVV WL ALLOW FOR THICKENING CLDS AND SOME SN TO PUSH
INTO THE WRN COUNTIES DURING THE AFTN. H7 SPECIFIC HUMIDITY FCST UP
TO 3 G/KG UNDER THE AXIS OF WAA INDICATES A FEW INCHES OF SN MAY
ACCUMULATE OVER THE FAR W BY 00Z DESPITE A RATHER HI...NARROW DGZ.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 355 AM EST MON FEB 9 2015
A FAIRLY ACTIVE LONG TERM FORECAST...WITH A SHORTWAVE AND LOW
PRESSURE SYSTEM MOVING THROUGH THE REGION TO START THE PERIOD AND
BRINGING A FEW INCHES OF SNOW ACROSS MUCH OF UPPER MICHIGAN.
COLD AIR WILL SURGE IN BEHIND THIS SYSTEM AND LEAD TO TEMPERATURES
FALLING WELL BELOW NORMAL ALONG WITH MODERATE LAKE EFFECT SNOW IN
THE NORTH WIND SNOWBELTS. AFTER A BRIEF REPRIEVE THURSDAY NIGHT INTO
FRIDAY MORNING...ANOTHER SURGE OF COLD AIR WILL DIVE SOUTHEAST
ACROSS THE AREA BEHIND A CLIPPER SYSTEM FRIDAY AFTERNOON AND BRING
ANOTHER ROUND OF LAKE EFFECT SNOW AND COLD TEMPERATURES TO START
THE WEEKEND.
THE SYSTEM THAT WILL BRING THE INITIAL WAVE OF PRECIPITATION IS
STARTING TO MOVE ONSHORE OVER THE PACIFIC NORTHWEST AND WILL SHIFT
EAST ACROSS THE ROCKIES TONIGHT. AS THE SHORTWAVE SLIDES EAST
THROUGH THE NORTHERN PLAINS ON TUESDAY...A WEAK SURFACE LOW WILL
REDEVELOP IN THE PLAINS. EXPECT SNOW TO SHIFT EAST INTO THE CWA
TUESDAY AFTERNOON UNDER THE BROAD MID LEVEL WARM AIR ADVECTION AND
THEN STRENGTHEN TUESDAY EVENING OVER THE WEST AS THE MAIN PIECE OF
SHORTWAVE ENERGY MOVES THROUGH THE AREA. THE MODELS HAVE SHIFTED
NORTH WITH THE TRACK OF THIS ENERGY...THUS QPF AMOUNTS HAVE TRENDED
UP WHEN COMPARED TO 24HRS AGO. THE LATEST CONSENSUS FROM THE 00Z
MODEL RUNS HAS QPF AMOUNTS IN THE 0.2-0.3 INCH RANGE FOR MUCH OF THE
CWA. WITH A LITTLE STRONGER PUSH OF THIS WARM AIR ADVECTION...THE
MODELS ARE INDICATING MORE OF THE CLOUD BEING BELOW THE DGZ VS IN
IT...SO WILL FOLLOW THE COBB SNOW RATIOS OF AROUND 13-14 TO 1 FOR
MUCH OF THE AREA. THIS ENDS UP PRODUCING SNOWFALL AMOUNTS IN THE
2 TO 4.5 INCH RANGE. WITH SOME AREAS LIKELY NEEDING AN ADVISORY
WITH THIS PERIOD OF SNOW...WILL CONTINUE TO MENTION IT IN THE HWO.
THE HEAVIEST SNOW SHOULD PUSH EAST FAIRLY QUICKLY THROUGH THE NIGHT
AND THAT DOES LEAVE A LITTLE BIT OF A CONCERN OF SOME FREEZING
DRIZZLE MIXING IN ON THE BACK SIDE OF THE PRECIP LATE TUESDAY NIGHT
AS THE DEEP MOISTURE DEPARTS. THE TEMPERATURE PROFILE IS HOVERING
AROUND -10C WHICH IS BORDERLINE FOR SEEING DRIZZLE...SO WILL STICK
TO SNOW AT THIS POINT AND REASSESS ON FUTURE SHIFTS.
EXPECT A BRIEF PERIOD LULL IN THE PRECIPITATION LATE TUESDAY NIGHT
AND WEDNESDAY MORNING AS THE LOW DEPARTS BEFORE THE COLD AIR SURGES
INTO THE AREA UNDER INCREASING NORTHWESTERLY WINDS AS A STRONG
NORTHERN STREAM SHORTWAVE DIVES SOUTHEAST ACROSS THE AREA. THIS WILL
USHER IN SIGNIFICANTLY COLDER AIR...850MB TEMPS FALLING FROM -10C
TUESDAY NIGHT TO -24C WEDNESDAY NIGHT...AND LEAD TO THE DEVELOPMENT
OF LAKE EFFECT. WITH THE ADDITIONAL MOISTURE AND STEEPENING LOW
LEVEL LAPSE RATES (LAKE EQUILIBRIUM LEVELS RISING TO AROUND 8KFT)
ASSOCIATED WITH THE SHORTWAVE AND COLDER AIR MOVING INTO THE
AREA...EXPECT A PERIOD OF MODERATE LAKE EFFECT SNOW LATE WEDNESDAY
AFTERNOON AND INTO WEDNESDAY NIGHT. WHILE IT WILL INITIALLY BE IN
THE NORTHWEST WIND SNOWBELTS...QUICKLY VEERING WINDS TO THE NORTH
WEDNESDAY EVENING WILL FOCUS THE SNOW IN THOSE FAVORED AREAS. WILL
FOCUS THE HIGHEST POPS/SNOWFALL OVER THE NORTH CENTRAL (AND NORTHERN
PARTS OF THE KEWEENAW PENINSULA) WHERE THE LONGEST ICE FREE FETCH
IS LOCATED...WITH LESSER AMOUNTS OVER THE WESTERN AREAS DUE TO THE
ICE AROUND ISLE ROYALE SHORTENING THE FETCH. WHILE MUCH OF THE
FORCING WILL BE IN THE DGZ DURING THIS FAVORABLE PERIOD OF LAKE
EFFECT...THINK THE STRONG WINDS (30-40KTS) WILL FRACTURE THE FLAKES
AND LIMIT THE ACCUMULATIONS SOME. BUT THIS WILL LEAD TO INCREASED
VISIBILITY REDUCTION (LIKELY BELOW 1/2MI AT TIMES IN SPOTS BETWEEN
MARQUETTE/MUNISING) AND WILL CONTINUE THAT HEIGHTENED WORDING IN
THE HWO. AT THIS POINT...HAVE SNOWFALL AMOUNTS OF 2-5 INCHES OVER
THE WEST AND 3 TO 7 INCHES OVER THE EAST FOR WEDNESDAY AFTERNOON
THROUGH THURSDAY.
EXPECT THE SNOW INTENSITY TO DIMINISH FROM WEST TO EAST ON
THURSDAY...AS AN APPROACHING HIGH PRESSURE RIDGE FROM CENTRAL CANADA
LOWERS INVERSION HEIGHTS AND BRINGS DRIER AIR INTO THE AREA. WITH
THE COLD AIR IN PLACE ON THURSDAY (HIGHS IN THE SINGLE DIGITS AND
LOWER TEENS ABOVE ZERO)...THURSDAY NIGHT LOOKS TO BE A COLD NIGHT
WHERE SKIES CLEAR OUT AWAY FROM ANY LINGERING LAKE EFFECT. IT MAY BE
A SHORT LIVED CLEARING...AS HIGH CLOUDS FROM THE NEXT SHORTWAVE
APPROACH THE AREA...BUT WILL STILL GO TOWARDS THE COLDER SOLUTIONS
(TEENS BELOW ZERO OVER THE INTERIOR) SINCE JUST A COUPLE HOURS OF
CLEARING AND LIGHT WINDS SHOULD ALLOW TEMPERATURES TO QUICKLY DROP.
THE AREA OF HIGH PRESSURE WILL SLIDE SOUTHEAST OF THE AREA ON
FRIDAY...AS ANOTHER SHORTWAVE DIVES SOUTHEAST ACROSS THE AREA
THAT AFTERNOON. EXPECT ANY SNOWFALL AMOUNTS TO BE LIGHT DUE TO
THE LIMITED MOISTURE AVAILABLE...BUT IT WILL USHER IN ANOTHER
PERIOD OF LAKE EFFECT SNOW FOR LATER FRIDAY NIGHT AND SATURDAY.
LATEST MODEL RUNS ARE SHOWING 850MB TEMPERATURES FALLING TO AROUND
-30C ON SATURDAY...WHICH WILL LIKELY HAVE HIGHS STRUGGLING TO GET
MUCH ABOVE ZERO AND HAVE TRENDED THE HIGHS DOWN SEVERAL DEGREES. IN
FACT...HIGHS WILL LIKELY BE CLOSE TO THE NORMAL LOWS FOR THAT TIME
FRAME. THAT AMOUNT OF COLD AIR WILL LEAD TO VERY FINE FLAKE LAKE
EFFECT AND WITH NORTHERLY WINDS ONCE AGAIN GUSTING TO 25-40KTS LATE
FRIDAY NIGHT THROUGH SATURDAY...EXPECT VERY POOR VISIBILITIES
(LIKELY NEAR ZERO AT TIMES BETWEEN MARQUETTE/MUNISING ALONG THE LAKE
SUPERIOR SHORELINE). WILL ADD THAT MENTION TO THE HWO WITH SIMILAR
WORDING TO WEDNESDAY NIGHT. HIGH PRESSURE BUILDING INTO THE AREA
SATURDAY NIGHT WILL ONCE AGAIN LEAD TO DIMINISHING LAKE EFFECT INTO
SUNDAY MORNING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1236 PM EST MON FEB 9 2015
LLVL MSTR TRAPPED BLO A SUBSIDENCE INVRN WL CAUSE PREDOMINANT MVFR
CONDITIONS AT CMX THIS FCST PERIOD. ALTHOUGH LO CLDS/MVFR CIGS WL
DOMINATE SAW EARLY...EXPECT SOME VFR WX TO RETURN TO SAW LATE THIS
AFTN/EVNG AS THE LLVL WINDS BACK TO A DOWNSLOPE NW DIRECTION UNDER
LARGER SCALE SUBSIDENCE AHEAD OF AN APRCHG HI PRES RDG. BUT AS THE
SFC RDG PASSES TO THE E OF THE AREA...VEERING WINDS BACK TO THE NE
OVERNGT AND THEN THE SE ON TUE WL BRING A RETURN OF LO CLDS AND
POSSIBLY EVEN IFR CIGS ON TUE. AT IWD...MVFR CIGS WL LINGER INTO
THIS EVNG IN THE NW FLOW AHEAD OF APRCH SFC RDG. AS THE FLOW TURNS
TO A DOWNSLOPE SE DIRECTION TNGT...EXPECT VFR CONDITIONS AT THAT
SITE THRU TUE MRNG.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 425 AM EST MON FEB 9 2015
A WEAK PRES GRADIENT OVER REGION WILL CONTINUE INTO TUESDAY AS A
HIGH PRES RIDGE MOVES OVER THE AREA. WINDS WILL BE GENERALLY LESS
THAN 20 KT THROUGH THE PD. LIGHT WINDS WILL CONTINUE TUE NIGHT INTO
WED MORNING AS A LOW PRES TROUGH MOVES INTO THE AREA...BUT THEN
WINDS RAMP UP ON THE BACKSIDE OF THE TROUGH WITH NORTH GALES 35-40
KNOTS AND HEAVY FREEZING SPRAY EXPECTED ACROSS MUCH OF THE LAKE LATE
WED INTO THU...STRONGEST CENTRAL AND EAST. NORTH WINDS SHOULD COME
DOWN BLO GALES LATE THU OVER THE ERN LAKE AS A HIGH PRES RIDGE MOVES
IN FM THE WEST. ANOTHER LOW PRES SYSTEM MOVING IN ON FRI WILL BRING
ANOTHER BOUT OF NORTH GALES 35-40 KNOTS AND HEAVY FREEZING SPRAY
LATE FRI NIGHT INTO SAT EVENING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON
FOR LSZ266-267.
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING FOR
LSZ265.
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING FOR
LSZ264.
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
414 PM CST MON FEB 9 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 413 PM CST MON FEB 9 2015
TURNED OUT TO BE A BEAUTIFUL DAY OUTSIDE OF WESTERN AND FAR SOUTHERN
MN...AS A WEDGE OF DRY AIR EMANATING FROM HIGH PRESSURE MOVING INTO
WRN ONTARIO HELPED CLEAR SKIES OUT. HOWEVER...TROUBLE IS ALREADY
BREWING TO OUR WEST AS WATER VAPOR IMAGERY SHOWS A POWERFUL WAVE
MOVING ACROSS THE NW CONUS. THIS WAVE WILL QUICKLY WORK ACROSS THE
DAKOTAS TONIGHT AND MN TUESDAY...PROVIDING US WITH THE POTPOURRI OF
WINTRY PRECIPITATION ON TUESDAY THAT WE HAVE BEEN ADVERTISING FOR
THE LAST SEVERAL DAYS.
WE DID NOT SEE MUCH CHANGE IN THE GUIDANCE TODAY WITH WHAT WAS SEEN
LAST NIGHT...SO THIS FORECAST DID NOT CHANGE A WHOLE LOT
EITHER...WITH ABOUT THE ONLY CHANGE OF SIGNIFICANCE BEING TO SLOW
DOWN HOW QUICKLY PRECIP MOVES INTO AND THEN ACROSS THE MPX CWA.
THIS FORECAST FAVORED THE GFS FOR BOTH P-TYPE AND QPF. FOR P-
TYPE...THE NAM...ALONG WITH THE RAP WERE CONSIDERABLY WARMER WITH
THE WARM NOSE ALOFT THAN THE GFS/ECMWF. HAD WE GONE THE NAM
ROUTE...A MIX WOULD HAVE BEEN MENTIONED FARTHER NORTH THAN IT IS
TUESDAY AFTERNOON...AND SAID MIX WOULD BE MORE OF A FZRA/SLEET/SNOW
MIX /MOST LIKELY TO LEAST LIKELY/ AS OPPOSED TO THE CURRENT
SLEET/SNOW/FZRA MIX THAT WE HAVE.
FOR QPF...THE NAM IS A CONSIDERABLE SRN OUTLIER. THE POTENTIAL
PROBLEM WITH IT STARTS TONIGHT...WHEN THE NAM SHOWS NEARLY A QUARTER
INCH OF QPF FALLING BY 12Z TUESDAY IN NE SODAK...IN ADDITION TO
ANOTHER QPF BULLSEYE FROM CENTRAL NODAK INTO SE NODAK. THE RAP AND
HOPWRF HAVE THE NODAK BULLSEYE...BUT SHOW CONSIDERABLY LESS QPF INTO
SODAK. THE LATENT HEAT DIFFERENCES THIS CREATES THEN CASCADES INTO
TUESDAY...WHEN THE NAM SHOWS QPF IN EXCESS OF 0.3" ALL THE WAY DOWN
TO MANKATO. THE GFS ON THE OTHER HAND HAS THE NODAK QPF...BUT MUCH
LOWER QPF DOWN INTO SODAK...SIMILAR TO WHAT THE RAP/HOPWRF
HAVE...HENCE FAVORING THE QPF THAT DIRECTION. WE THEN TEMPERED THE
GFS QPF A BIT WITH THE ECMWF/SREF AND ENDED UP WITH 0.3" QPF DOWN
ABOUT AS FAR SOUTH AS THE TWIN CITIES DOWN TO MENOMINEE. CONVERTING
THIS QPF OVER TO SNOW WITH RATIOS IN THE 10-12:1 RANGE AND WE ENDED
UP WITH SNOWFALL AMOUNTS BETWEEN 2 AND 5 INCHES NORTH OF A
MORRIS/MINNEAPOLIS/EAU CLAIRE LINE WITH THE LARGEST AMOUNTS UP
AROUND MILLE LACS LAKE TO POINTS EAST.
THE HEAVIEST SNOW IS EXPECTED IN CENTRAL MN AS THEY WILL GET THE
COMBINATION OF WAA AND DEFORMATION SNOW. FARTHER SOUTH...THE
MAJORITY OF THE PRECIP WILL FALL IN THE WAA BAND. THIS WILL RESULT
IN A 2-4 HOUR WINDOW WHERE SNOWFALL RATES ARE LIKELY NEAR OR IN
EXCESS OF AN INCH PER HOUR...SO THIS SNOW WILL FALL IN A SHORT
AMOUNT OF TIME. TIMING WISE...THINGS DO NOT LOOK TO BE TO DISSIMILAR
FROM WHAT WE SAW LAST TUESDAY WHEN ABOUT 2 INCHES OF SNOW SEVERAL
IMPACTED THE EVENING COMMUTE IN THE TWIN CITIES. WITH A SIMILAR
SCENARIO EXPECTED TO TO PLAY OUT TOMORROW...PULLED THE ADVISORY DOWN
TO COVER ALL BUT THE SRN TWIN CITIES METRO. DECIDED AGAINST PUTTING
HEADLINES ANY FARTHER SOUTH THAN WHAT WE HAVE NOW SINCE THERE ARE
MORE QUESTIONS AS TO HOW MUCH PRECIP LOCATIONS FARTHER SOUTH WILL
ACTUALLY SEE. IN ADDITION...WITH CURRENT PRIMARY P-TYPE EXPECTED TO
BE SLEET AS OPPOSED TO FREEZING RAIN...THAT WILL LIMIT THE TRAVEL
IMPACT FROM THIS PRECIP AS WELL. HOWEVER...THIS WILL BE AN AREA THAT
WILL NEED TO BE CLOSELY MONITORED THROUGH THE NIGHT.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 413 PM CST MON FEB 9 2015
THE EXTENDED PERIOD CAN BE CHARACTERIZED AS BLW NORMAL IN TERMS OF
TEMPERATURES AS THE MEAN PATTERN SHIFTS TO A MORE NW
DIRECTION...LEADING TO COLDER CANADIAN AIR FILTERING SOUTHWARD.
A BRIEF PERIOD TUESDAY EVENING OF MIXED PRECIPITATION ALONG THE MN
RIVER VALLEY WILL QUICKLY CHG TO ALL SNOW AS A MUCH COLDER AIR MASS
REPLACES THE CURRENT ONE. BASED ON THE STRENGTH OF A SECONDARY
SHRTWV MOVING SE ACROSS THE UPPER MIDWEST TUESDAY NIGHT/WEDNESDAY
AND THE STRENGTH OF THE CAA BEHIND IT...BREEZY/WINDY CONDS WILL
DEVELOP...ESPECIALLY IN THE TYPICAL AREAS OF WC/SC MN WHERE GUSTS UP
TO 45 MPH WILL BE COMMON. WAS CONSIDERING A BLOWING SNOW PROBLEM IN
THESE AREAS...BUT DO TO A LACK OF SNOW COVER AND NO ADDITIONAL NEW
SNOW EXPECTED...DO NOT ANTICIPATE ANY CONCERNS.
VERY LITTLE CHC/S OF PRECIPITATION IS EXPECTED PAST TUESDAY
EVENING...WITH THE EXCEPTION BY NEXT MONDAY AS THE MEAN PATTERN WILL
REMAIN DRY AND UNEVENTFUL. TWO STRONG COLD FRONTS WILL MOVE ACROSS
OUR REGION...ONE WILL OCCUR TUESDAY AFTN/EVENING...AND ANOTHER
FRIDAY AFTN/SATURDAY MORNING. THESE FRONTS WILL CAUSE A FEW SNOW
SHOWERS TO DEVELOP...BUT AGAIN NOT EXPECTING MUCH IN THE WAY OF
ACCUMULATIONS.
OVER THE PAST TWO MONTHS...THE MEAN AREA OF ARCTIC AIR HAS REMAINED
ACROSS NE NORTH AMERICA...AFFECTING MAINLY THE NE CONUS...AND
EASTERN CANADA. ONCE IN A WHILE A BRIEF COLD SPELL MOVES ACROSS THE
UPPER MIDWEST/GREAT LAKES AS THE PATTERN BUCKLES. THE LATEST
PROBABILISTIC FORECASTS ON NCEP GEFS REFORECASTS CFS/V2...HAS 50H
ANOMALIES SHIFTING ACROSS THE ALASKA REGION...WITH A SECONDARY 50H
ANOMALY FOCUSING ACROSS THE DEEP SOUTH/SW. THIS BASICALLY SHIFTS THE
COLDER AIR ACROSS NORTHEAST CANADA FURTHER TO THE SW ACROSS THE
GREAT LAKES...AND THE EASTERN 1/3 OF NORTH AMERICA. THIS ALSO
SUGGESTS A STRONGER CORRELATION OF ABV NORMAL ANOMALIES FOCUSING
ACROSS THE GREAT BASIN AND THE FAR WEST COAST. THE TIME FRAME FOR
THIS PERIOD IS FEB 15 TO FEB 24. THE 45 DAY CFS PLUMES FOR THE PAST
4 RUNS DOES SUPPORT THE COLDER PATTERN DEVELOPING IN OUR REGION FOR
THE SECOND AND THIRD WEEK OF FEB 24. IN ADDITION...IT SEEMS IT MAYBE
A WETTER PATTERN AS THE STRONGER JET WORKS ACROSS THE CENTRAL
CONUS...LEADING TO A BETTER CHC OF A THERMAL BOUNDARY AND WIDESPREAD
PRECIPITATION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 104 PM CST MON FEB 9 2015
A NICE WEDGE OF DRY AIR HAS PUSHED DOWN FROM THE NE...HELPING
CLEAR SKIES OUT ACROSS MUCH OF THE AREA THIS MORNING. THE MAIN
QUESTION IS HOW FAR WEST DOES THIS CLEARING MAKE IT. FOR
NOW...LEFT CLOUDS IN ONLY AT AXN...BUT IT WILL BE CLOSE.
OTHERWISE...THIS DRY AIR LOOKS TO BE TOUGH TO DISLODGE...WITH
MVFR OR LOWER CIGS MOVING BACK IN WITH THE PRECIP TUE MORNING. AS
FOR THAT PRECIP...ONLY CHANGE MADE FROM 12Z TAFS WAS TO SLOW DOWN
THE ARRIVAL OF THE PRECIP SOME. GFS/NAM SOUNDINGS SHOW THE INITIAL
HOUR OR TWO OF PRECIP BEING A SLEET/SNOW MIX AT AXN BEFORE GOING
ALL SNOW...WHILE RWF WILL LIKELY SEE A LITTLE BE OF EVERYTHING.
KEPT STC/MSP AS ALL SNOW...THOUGH THE NAM BRINGS WARM AIR FAR
ENOUGH NORTH TO BRING SOME MIX INTO THE EQUATION AT MSP. THIS
SYSTEM LOOKS TO BRING A QUICK...BUT HEAVY BURST OF PRECIP LATE
MORNING THROUGH THE AFTERNOON...WITH MORE PERSISTENT SNOW HANGING
UP IN CENTRAL MN...LIKELY NEAR OR JUST NORTH OF AXN/STC.
KMSP...CONFIDENCE IS HIGH IN VFR CONDS REMAINING THROUGH
12Z...THOUGH THERE IS SOME THREAT WE COULD SEE MVFR CIGS ARRIVE A
COUPLE OF HOURS AHEAD OF THE PRECIP. GIVEN MODEL AGREEMENT ON
PRECIP TIMING TUE MORNING...EXPECT PRECIP TO BREAK OUT +/- 1.5
HOURS FROM WHAT IS IN THE TAF. FAVORED THE GFS...WHICH KEEPS PYTPE
AS SNOW...WHICH IS THE PREDOMINATE P-TYPE SEEN WITH THE SREF.
THERE WILL LIKELY BE A 2-4 HOUR WINDOW DURING THE AFTERNOON WITH A
STRONG PRECIP BURST...WHERE VIS...ASSUMING IT IS ALL SNOW...WILL
LIKELY GET DOWN TO 1/2SM. CONFIDENCE IS TO LOW IN TIMING WHEN THAT
MAY OCCUR AND WE HAVE A COUPLE OF MORE ITERATION OF THE TAF
BEFORE WE GET THERE ANYWAYS.
/OUTLOOK FOR KMSP/
WED...MVFR WITH. WINDS NW 15G25-30KT.
THU...BCMG VFR. WINDS BCMG LGT/VAR.
FRI...CHC MVFR CIGS. WINDS SW 5-10 KTS BCMG NW 15-20G25 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM 6 AM TO 9 PM CST TUESDAY FOR MNZ041-
042-047>049-054>058-064.
WINTER WEATHER ADVISORY FROM 9 AM TUESDAY TO MIDNIGHT CST
TUESDAY NIGHT FOR MNZ043>045-050>053-059>063.
WI...WINTER WEATHER ADVISORY FROM 9 AM TUESDAY TO MIDNIGHT CST
TUESDAY NIGHT FOR WIZ014-015-023-025.
&&
$$
SHORT TERM...MPG
LONG TERM...JLT
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1058 PM CST Sun Feb 8 2015
.UPDATE...
Issued at 932 PM CST SUN FEB 8 2015
Satellite imagery and surface obs show an extensive low cloud deck
slipping south while the western edge expands slowly westward.
NAM/RAP condensation pressure deficit progs as well as latest NAM
Bufr and RAP soundings show this moisture will be trapped under the
frontal inversion and thus difficult to break up while cold air
advection is occurring. With this in mind will increase cloud cover
overnight as well as into at least Monday afternoon. This now calls
into question Monday`s high temperatures. If we do indeed remain
mainly cloudy highs will struggle to reach 40 over the west central
CWA. New model guidance supports lowering highs for tomorrow.
&&
.DISCUSSION...
Issued at 241 PM CST SUN FEB 8 2015
Benign weather conditions will continue tonight through much of the
forecast period with no mentionable PoPs. NW flow aloft will
dominate as the region sits on the periphery of upper-level trough
after trough that rotates down from Canada, through the Great
Lakes region, and the Northeast. In the middle of the upcoming week,
phasing occurs across the center of the country as a shortwave
ejecting out of the Pacific NW becomes enveloped by longwave
trough rotating through the Great Lakes. This side lobe of colder
air will find its way into this forecast area, courtesy of surface
high pressure riding down from Canada via North Dakota on the
backside of the phasing with the longwave trough.
Behind the weak front that came through today, temperatures
tonight and tomorrow will be cooler than what was observed this
weekend. They`ll be closer to normal for this time of year but
still a few degrees above. Temps will then rise again for Tuesday,
level off Wednesday, then drop well off on Thursday due to the
aforementioned colder air expected to arrive. This chilly weather
will be very short-lived, however, as highs on Friday noticeably
rebound.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday Night)
Issued at 1049 PM CST SUN FEB 8 2015
Scattered 7kft deck with a few sprinkles has moved across the
terminals this evening ahead of an MVFR stratus deck that is now
pushing towards the terminals from the north. Light fog has begun to
develop out ahead of this stratus deck and upstream obs indicate vsby
could drop down to 3SM. Vsby looks to improve by tomorrow morning
with MVFR stratus deck hanging tight across the region through
tomorrow afternoon given most recent model analysis. Winds will
gradually shift to more easterly by the end of the period.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...MJ
DISCUSSION...lg
AVIATION...PMM
AREA FORECAST DISCUSSION...UPDATED
NWS GLASGOW MT
1039 AM MST MON FEB 9 2015
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH WEDNESDAY...
AS PROMISED...REVISITED THE FOG SITUATION. THE FOGS SHOWS NO SIGNS
OF DISSIPATING SOON...EXCEPT FOR GARFIELD COUNTY. THEREFORE
UPDATED WX GRID AFTERNOON FOG BASED ON RAP AND HRRR. MODIFIED THE
DENSE FOG ADVISORY TO STRETCH OUT TO 21Z. SCT
PREVIOUS UPDATE...
THE DENSE FOG ADVISORY REMAINS IN EFFECT THIS MORNING AND IT WILL
BE REVISITED LATER IN THE MORNING. THE MAIN UPDATE WAS TO
TEMPERATURES WHICH SHOULD TREND COOLER TODAY. MADE UPDATE BASED ON
RAP GUIDANCE WHICH LOWERED MAXIMUM TEMPERATURES ALONG AND NORTH OF
THE HI-LINE ABOUT 6 DEGREES COOLER. THIS INCREASED THE LIKELIHOOD
THAT FREEZING RAIN WILL BEING SOONER. THIS RESULTED IN ALTERING
THE START TIME AND SLIGHTLY EXPANDING THE FZRA ADVSRY. AGAIN USED
THE POT TOOL TO DETERMINE THE PRECIPITATION TYPE. SCT
PREVIOUS DISCUSSION...
SYNOPTIC SET UP...COLDEST AIR OF THE NORTHERN HEMISPHERE SET OVER
THE CANADIAN TERRITORIES WITH MODIFIED ARCTIC AIR WARMING DOWN
THROUGH THE CANADIAN PRAIRIE PROVINCES TO THE INTERNATIONAL BORDER
WHERE ITS FORMS A SHARP FRONTAL BOUNDARY. A WARM CORE RIDGE RUNS
NORTH FROM THE FOUR CORNERS THROUGH UTAH AND COMES TO A HEAD OVER
WESTERN MONTANA. FARTHER WEST...A COOL TROUGH RUNS FROM NORTHERN
CALIFORNIA UP INTO THE PACIFIC NORTHWEST AND SOUTHERN BRITISH
COLUMBIA.
TODAY THROUGH TONIGHT...MORNING WILL BEGIN AS DENSE FOG FROM THE
WAFFLING FRONTAL BOUNDARY GETS PUSHED BACK TO THE NORTH. THE TIP
OF THE RIDGE WILL BE MOVING THIS WARM FRONT BACK TO THE
INTERNATIONAL BORDER DURING THE AFTERNOON BUT AS THE RIDGE EXITS
TO THE EAST. PACIFIC MOISTURE WILL BEGIN FLOWING OVER THE BORDER
DURING THE LATE AFTERNOON AND FORMING UP RAIN SHOWERS ACROSS THE
REGION. A SHORTWAVE EMBEDDED IN THE FLOW WILL AMPLIFY THE [PRECIP
INTENSITY OVERNIGHT AND ALLOW SOME OF THE MODIFIED COLD AIR DOWN
OVERNIGHT. AS THE SURFACE AIR IS BELOW FREEZING A CHANGE OVER TO
FREEZING RAIN WILL BE POSSIBLE ALONG THE FRONT THIS EVENING.
THEREFORE A FREEZING RAIN ADVISORY IS OUT THROUGH THE AFTERNOON
AND OVERNIGHT PERIODS.
TUESDAY THROUGH WEDNESDAY...BY TUESDAY ENOUGH COLD WILL HAVE MOVED
INTO THE AREA TO TRANSITION ANY REMAINING PRECIPITATION TO SNOW
SHOWERS. AS MOISTURE SHOULD BE LACKING BY THIS TIME CHANCES FOR
SNOW ARE VERY LOW AND LIKELY ON FLURRIES WILL BE EXPERIENCE
TUESDAY. HIGHS WILL ALSO DROP BELOW FREEZING AND SHOULD CONTINUE
THROUGH WEDNESDAY. GAH
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
MODELS HAVE AN UPPER RIDGE OVER THE WESTERN US FOR THURSDAY AND
FRIDAY. THE RIDGE AXIS IS FORECASTED TO BE OVER EASTERN WASHINGTON
WHICH PUTS EASTERN MONTANA IN NORTHWEST FLOW ALOFT. ODELS BRING A
WARM FRONT EAST THURSDAY AND THURSDAY NIGHT WITH LITTLE OR NO
MOISTURE. WILL MAINTAIN DRY FORECAST. TEMPERATURES WILL BE WARMER
IN THE SOUTHWEST THAN IN THE NORTHEAST AS LOW LEVEL INVERSIONS ARE
EXPECTED TO LIMIT WARMING IN THE NORTHEAST.
THE MODELS HAVE A SHORTWAVE TROUGH MOVING SOUTHEAST ACROSS
SASKATCHEWAN AND NORTH DAKOTA ON FRIDAY. THIS WILL BRING THE FRONT
BACK WEST INTO EASTERN MONTANA. THERE IS LITTLE OR NO MOISTURE
WITH THE FRONT. WILL MAINTAIN DRY FORECAST. MODELS DIFFER SOMEWHAT
ON HOW FAR THE FRONT GOES BEFORE IT MOVES EAST AGAIN ON SATURDAY.
WILL MAINTAIN COLDER NORTHEAST AND WARMER SOUTHWEST FOR
TEMPERATURE FORECAST.
THE RIDGE TO THE WEST GETS FLATTENED ON SATURDAY BY SHORTWAVE
TROUGH MOVING INLAND ACROSS BRITISH COLUMBIA AND ALBERTA. THE
SYSTEM WILL BRING A COLD FRONT THROUGH THE AREA ON SUNDAY WITH
ENOUGH MOISTURE FOR A SLIGHT CHANCE OF PRECIP. A MIX OF PRECIP TYPES ARE
POSSIBLE AS WARMER AIR ALOFT IS EXPECTED SATURDAY NIGHT WHICH
COULD LEAD TO SOME LIGHT FREEZING RAIN.
A STRONGER UPPER TROUGH MOVES SOUTHEAST ACROSS THE PACIFIC
NORTHWEST EARLY NEXT WEEK AND BRINGS A STRONGER COLD FRONT THROUGH
THE AREA WHICH MUCH COLDER TEMPERATURES. THE SYSTEM COULD ALSO
BRING SOME SNOW TO THE AREA. FORRESTER
&&
.AVIATION...
IFR/LIFR THIS MORNING WITH EITHER DENSE FOG OR VERY LOW CLOUD CEILINGS.
THE FOG IS EXPECTED BEGIN TO THIN AS AN AREA OF RAIN MOVES INTO
THE REGION FROM THE WEST THIS AFTERNOON. WITH TEMPERATURES ONLY
RISING INTO THE LOW TO MID 30S...FREEZING RAIN IS LIKELY AT THE
TAF SITES FOR THIS AFTERNOON AND EVENING ALONG WITH A MIX OF LOW VFR/MVFR
CEILINGS.
WINDS: WILL BE MAINLY FROM THE EAST TODAY 10 TO 15 KNOTS. A COLD
FRONT TONIGHT WILL TURN THE WINDS TO THE NORTHWEST.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 2 PM MST THIS AFTERNOON FOR CENTRAL AND
SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...DANIELS...
DAWSON...EASTERN ROOSEVELT...MCCONE...NORTHERN PHILLIPS...
NORTHERN VALLEY...PRAIRIE...RICHLAND...SHERIDAN...WESTERN
ROOSEVELT...WIBAUX.
FREEZING RAIN ADVISORY UNTIL 5 AM MST TUESDAY FOR CENTRAL AND
SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...DANIELS...
EASTERN ROOSEVELT...NORTHERN PHILLIPS...NORTHERN VALLEY...
RICHLAND...SHERIDAN...WESTERN ROOSEVELT.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
255 PM CST MON FEB 9 2015
.SYNOPSIS...
ISSUED AT 254 PM CST MON FEB 9 2015
AT H5 TROUGH FROM GREAT LAKES INTO FLORIDA PANHANDLE WITH
ASSOCIATED PRECIPITATION ALL ALONG THE EASTERN SEABOARD. RIDGE
INTO THE NORTHERN PLAINS WITH FAIRLY STRONG WAVE MOVING ACROSS THE
PACIFIC NORTHWEST.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 254 PM CST MON FEB 9 2015
MAIN FORECAST CONCERN FOR THE OVERNIGHT REVOLVES AROUND THE WESTWARD
RETURN OF STRATUS AND/OR FOG. THE NAM MODEL IS ONCE AGAIN THE MOST
BULLISH WITH REDUCED VISIBILITY...BRINGING DENSE FOG AS FAR WEST AS
THE HIGHWAY 83 CORRIDOR. THE HRRR SEEMS TO BE A GOOD COMPROMISE FOR
NOW...WHICH INDICATES FOG IN THE SAME GENERAL AREA AS SEEN EARLIER
TODAY. SURFACE LOW PRESSURE IS SHOWN TO MOVE EAST ACROSS SOUTHERN
SOUTH DAKOTA OVERNIGHT...DRAGGING A TROUGH THROUGH THE
SANDHILLS...SO AM EXPECTING A GREATER WESTWARD...OR
SOUTHWEST...TRAJECTORY OF THE LOWER TROPOSPHERIC WIND...WHICH WILL
DRAW DRY LOW LEVEL AIR BACK INTO THE REGION. THIS BOUNDARY IS SHOWN
TO BE ALONG OR NEAR HIGHWAY 281 BY 12Z TOMORROW. FOR THIS...WOULD
EXPECT SOME IMPROVEMENT IN VISIBILITY AND SKY COVER FROM WEST TO
EAST THROUGH THE OVERNIGHT HOURS AND THE STRATUS SHOULD ONLY BE
CONFINED TO OUR FAR EAST.
A WEAK UPPER LEVEL DISTURBANCE/PV ANOMALY WILL CROSS THE
CENTRAL/NORTHERN PLAINS OVERNIGHT PROVIDING FOR A LEAST A SLIGHT
CHANCE OF PRECIPITATION ACROSS OUR FAR NORTHEAST. THE MODELS ARE
KEYING ON THE GREATEST FORCING WELL NORTH OF THE FORECAST AREA...AND
WITH SATURATION CONFINED TO THE LOWER TROPOSPHERE...RAIN WILL BE
DIFFICULT. AM LEANING TOWARD A DRIZZLE POTENTIAL...OR VERY LIGHT
RAIN...IF PRECIPITATION WERE TO BE REALIZED. ANY LIFT IS QUICKLY
EAST OF THE FORECAST AREA BY 12Z TUESDAY...BEYOND THAT...THE REST OF
THE DAY APPEARS DRY.
TEMPERATURES OVERNIGHT WILL BE MILD AS WAA SPREADS EAST AHEAD OF THE
PASSING SURFACE TROUGH. FORECAST LOWS RANGE FROM THE UPPER 20S IN
THE RIVER VALLEYS...TO THE MID 30S ACROSS THE HEART OF THE SANDHILLS
WHERE GREATER MIXING IS ANTICIPATED. FOR TUESDAY...THE DISTURBANCE
WILL DRAW SLIGHTLY COOLER AIR ACROSS WEST CENTRAL NEBRASKA. HIGHS
WERE TRENDED ACCORDINGLY...WITH MOST LOCATIONS SEEING A DROP OF 5-7F
FROM WHAT WAS OBSERVED TODAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 254 PM CST MON FEB 9 2015
MODELS IN FAIR AGREEMENT IN MID TERM AND THEN HAVING SOME
VARIABILITY IN LONG TERM SOLUTIONS. TUESDAY NIGHT COOLER AIR
FILTERS IN ACROSS THE NORTHERN PLAINS INTO WESTERN NEBRASKA. WITH
THE UPPER RIDGE IN PLACE THE HIGH PRESSURE WILL BE MOVED FURTHER
EAST WITH A STATIONARY BOUNDARY FROM THE NORTHERN NEBRASKA
PANHANDLE INTO BROKEN BOW. WARMER 40S TO THE SOUTHWEST AND 30S TO
THE NORTHEAST. LOWS WEDNESDAY NIGHT QUITE COLD WITH MOSTLY CLEAR
SKIES AND LIGHT WINDS. SINGLE DIGITS ONEILL AND LOW 20S OVER
SOUTHWEST NEBRASKA. SOUTHERLY WINDS THURSDAY WILL MODERATE
TEMPERATURES SOME WHAT ON THE BACKSIDE OF THE SURFACE HIGH. MILD
NIGHT THURSDAY NIGHT WITH RETURN FLOW. FRIDAY TEMPERATURES REBOUND
INTO THE 40S NORTH AND 50S SOUTH. A DRY BACKDOOR COLD FRONT WILL
MOVE ACROSS THE FORECAST AREA FRIDAY NIGHT INTO SATURDAY WITH
HIGHS ON SATURDAY RANGING FROM THE 20S ONEILL TO MID 40S IMPERIAL.
TEMPERATURES REBOUND SUNDAY WITH 40S NORTH AND 50S SOUTH IN RETURN
FLOW. INCREASING MOISTURE ACROSS THE SOUTHERN PLAINS SUNDAY AND AN
ARCTIC COLD FRONT MOVING SOUTH ACROSS THE NORTHERN PLAINS WILL SEE
A RETURN TO SNOW IN THE FORECAST SUNDAY NIGHT INTO MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1114 AM CST MON FEB 9 2015
UNCERTAINTY IN THE 18Z TAF FORECAST CYCLE AS NEAR TERM GUIDANCE IS
MIXED ON THE EVENTUAL BREAK UP OF STRATUS THAT IS CURRENTLY SITUATED
ACROSS NORTH CENTRAL NEBRASKA. THE NAM MODEL CONTINUES TO BE THE
MOST BULLISH IN DEVELOPING STRATUS WEST ACROSS MUCH OF WEST
CENTRAL NEBRASKA...INCLUDING THE KLBF AND KVTN TERMINALS OVERNIGHT.
THE GFS IS SUGGESTING CLEAR SKIES BELOW 12K FEET. ATTM...DISCOUNTING
THE NAM GUIDANCE AS SOUTHWEST LOWER TROPOSPHERIC FLOW SHOULD HELP
SCOUR MOISTURE. IN ADDITION...THE MODEL SHOWED A SIMILAR WESTWARD
PROGRESSION LAST NIGHT IMPACTING KVTN AND KLBF...THIS HAS NOT
HAPPENED IN A WHILE...DESPITE SOLID SNOW MELT. FOR NOW WILL GO
WITH VFR AT BOTH TERMINALS...BUT CANNOT ENTIRE RULE OUT THAT UPDATES
MAY BE NEEDED. OTHERWISE DENSE FOG IS SHOWN TO IMPACT OUR EASTERN
TERMINALS THROUGH MUCH OF THE FORECAST PERIOD...THERE MAY BE A
BRIEF PERIOD WHERE CEILINGS LIFT AT KONL...BUT MODEL GUIDANCE
POINTS TO A QUICK RETURN OVERNIGHT...THIS MAY ALSO IMPACT THE KBBW
TERMINAL.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...POWER
SHORT TERM...JACOBS
LONG TERM...POWER
AVIATION...JACOBS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1148 AM CST MON FEB 9 2015
.UPDATE...
ISSUED AT 614 AM CST MON FEB 9 2015
PER SATELLITE TRENDS AND HRRR VISIBILITY GUIDANCE...FELT IT
PRUDENT TO ADD FRANKLIN/SMITH/OSBORNE COUNTIES TO EXISTING DENSE
FOG ADVISORY...AS THE FAR WESTERN EDGE OF STRATUS IS JUST STARTING
TO CREEP INTO THESE AREAS AND THE WORST FOG SEEMS TO BE ALONG AND
ROUGHLY 50 MILES BEHIND THE EDGE. INTERESTINGLY...THERE ARE SOME
SIGNS THAT THE WESTERN EDGE OF FOG/STRATUS MAY FINALLY BE
STALLING...AND ONCOMING DAY SHIFT WILL HAVE TO MONITOR THE
EVOLUTION OF THIS VERY SHARP EDGE TODAY...AND POTENTIALLY MAJOR
RESULTANT IMPLICATIONS FOR TEMPS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 456 AM CST MON FEB 9 2015
WHAT 24 HOURS AGO APPEARED TO BE A FAIRLY "STRAIGHTFORWARD" SHORT
TERM PERIOD WITH WELL-ABOVE AVERAGE TEMPS CWA-WIDE HAS
UNFORTUNATELY MORPHED INTO A RATHER CHALLENGING PERIOD WITH
PLENTY OF FOG (SOME DENSE) TO START OUT...THE LIKELIHOOD OF LOW
STRATUS AND POSSIBLY AT-LEAST-LIGHT FOG HANGING ON EVEN THROUGH
THIS AFTERNOON WITHIN THE NORTHEAST 1/3 TO 1/2 OF THE CWA...AND OF
COURSE THE RESULTANT FAIRLY MAJOR IMPLICATIONS ON TEMPERATURES.
THIS SETS THE STAGE FOR POSSIBLY ONE OF THE MORE CHALLENGING 1ST
PERIOD HIGH TEMP FORECASTS THIS FORECASTER HAS SEEN IN AWHILE...AS
THERE WILL EASILY BE A 20-30 DEGREE GRADIENT FROM THE
CLOUDY/CHILLIER EAST-NORTHEAST COUNTIES TO THE MOSTLY SUNNY/WARMER
WEST/SOUTHWEST COUNTIES. ACROSS A CORRIDOR THROUGH THE CENTRAL
CWA HERE THE EDGE OF THE STUBBORN STRATUS WILL LIKELY RESIDE MUCH
OF THE DAY...THERE IS EASILY 10-DEGREE TEMP BUST POTENTIAL. PUT
ANOTHER WAY...UNFORTUNATELY THOSE HOPING FOR A REALLY NICE AND AT
LEAST PARTIALLY SUNNY DAY ANYWHERE NEAR AND EAST THROUGH NORTH OF
THE TRI-CITIES WILL BE FACING A GLOOMY MONDAY LETDOWN.
NOT EVEN COUNTING THE FAIRLY SIGNIFICANT FORECAST MODIFICATIONS
MADE TO MUCH OF THE CWA FOR TODAY...THERE IS YET ANOTHER QUANDARY
REGARDING WHETHER AT LEAST LIGHT FOG WILL REALLY EVER COMPLETELY
GO AWAY ESPECIALLY WITHIN THE NORTHEAST 1/3 OF THE CWA THROUGH
THESE NEXT 24 HOURS...WITH AT LEAST SOME POSSIBILITY OF DENSE FOG
ISSUES AGAIN SHOWING THEIR HAND TONIGHT. HOWEVER...WITH STRONGER
SOUTHEAST-SOUTHERLY SURFACE BREEZES AND BOUNDARY LAYER FLOW THAN
THIS MORNING...CONFIDENCE IS NOT HIGH ENOUGH AT THIS TIME TO GO
WITH ANYTHING MORE THAN A BASELINE "PATCHY FOG" MENTION FOR
TONIGHT.
WITH EVERYTHING ELSE GOING ON...FORTUNATELY CONFIDENCE IS STILL
PRETTY HIGH IN A PRECIP-FREE 24 HOURS ACROSS THE VAST MAJORITY OF
THE CWA. THAT BEING SAID...BOTH THE 00Z/06Z NAM SUGGEST THAT LOW-
LEVEL SATURATION DEPTH/BOUNDARY LAYER MIXING COULD GET DEEP ENOUGH
OVERNIGHT TO SUPPORT AT LEAST SOME SPOTTY LIGHT DRIZZLE OVERNIGHT
MAINLY NEAR/NORTH OF NEBRASKA HIGHWAY 92 AND THIS HAS BEEN ADDED
TO THE FORECAST AS WELL. FORTUNATELY...WITH LOW TEMPS FORECAST TO
DROP NO LOWER THAN 32-34 DEGREES ACROSS THE MAJORITY OF THIS
AREA...WAS ABLE TO STEER CLEAR OF ANY LIGHT FREEZING DRIZZLE/ICING
CONCERNS.
GOING OVER THE CURRENT SITUATION AS OF 1030Z/430 AM...BROAD
SURFACE HIGH PRESSURE IS PROVIDING A VERY LIGHT/VARIABLE WIND
REGIME THIS MORNING...WHICH HAS SET THE STAGE FOR LOCALLY DENSE
FOG DEVELOPMENT ESPECIALLY ALONG AND WITHIN ROUGHLY 50 MILES
BEHIND THE LEADING EDGE OF A SOLID DECK OF LOW STRATUS WHICH HAS
STEADILY "BACK-DOORED" INTO THE CWA FROM EAST- TO-WEST SINCE LAST
EVENING BEHIND A MODEST COLD FRONT. AS OF THIS WRITING...THIS
STRATUS IS ROUGHLY BISECTING THE CWA FROM WEST- TO- EAST...WITH
WESTERN COUNTIES CLEAR AND LARGELY FOG-FREE IN SHARP CONTRAST TO
THE SITUATION FARTHER EAST. IN THE LARGER-SCALE MID- UPPER LEVEL
SCENE...YOU WOULDN/T EXPECT TO HAVE SO MANY COMPLICATIONS GOING ON
AT THE SURFACE...AS WATER VAPOR SATELLITE AND SHORT TERM MODEL
DATA REVEAL A FAIRLY BENIGN NORTHWESTERLY FLOW IN THE PRESENCE OF
BROAD SHORTWAVE RIDGING OVER THE CENTRAL PLAINS. TEMP-WISE...MOST
OF THE CWA SHOULD REALIZE OVERNIGHT LOWS IN THE 27-33 RANGE...WITH
THE LOW STRATUS OBVIOUSLY HALTING MUCH OF ANY FALL CENTRAL AND
EAST.
LOOKING AHEAD-FORECAST WISE...THE PARAMOUNT CONCERN RIGHT AWAY IS
THE ONGOING DENSE FOG ADVISORY CURRENTLY IN EFFECT FOR MOST
COUNTIES EAST-NORTHEAST OF A KEARNEY-OSBORNE LINE. TO ITS
CREDIT...THE VARIOUS OVERNIGHT HRRR VISIBILITY PRODUCT RUNS HAVE
BEEN DOING AN EXCELLENT JOB CAPTURING THE WESTWARD PROGRESSION OF
THE STRATUS AND FOG. BASED ON ITS TRENDS ALONG WITH 11-3.9 MICRON
SATELLITE...CANNOT RULE OUT A FEW MORE COUNTIES NEEDING TACKED
ONTO THE WEST SIDE OF THE EXISTING ADVISORY WITHIN THE NEXT FEW
HOURS...AND WILL KEEP AN EYE ON THINGS. AS FOR ADVISORY
TIMING...IN KEEPING IN COLLABORATION WITH SURROUNDING OFFICES THAT
ISSUED THEIR ADVISORIES FIRST...HAVE GONE WITH A 15Z/9AM
EXPIRATION TIME...BUT AM FEELING MORE AND MORE STRONGLY THAT DAY
SHIFT WILL LIKELY HAVE TO EXTEND A DECENT PORTION OF THE AREA
THROUGH AT LEAST 18Z/NOON...ESPECIALLY NEAR AND EAST-NORTHEAST OF
THE TRI- CITIES. WITH SURFACE BREEZES ONLY VERY SLOWLY PICKING UP
TODAY TO GENERALLY 10-15 MPH FROM THE SOUTHEAST...THIS HAS THE
LOOKS OF A DAY THAT COULD KEEP AT LEAST LIGHT FOG FIRMLY IN PLACE
ESSENTIALLY ALL DAY LONG IN AT LEAST A HANDFUL OF COUNTIES.
MOVING BEYOND THE OBVIOUS FOG ISSUES...THE NEXT QUESTION FOR TODAY
IS WHETHER THE LOW STRATUS WILL TRY TO BREAK UP AT ALL AND/OR
ERODE FROM SOUTHWEST-TO-NORTHEAST WITH DAYTIME HEATING. FOR
THIS...AGAIN FOLLOWED VERY CLOSE TO HRRR MODEL THINKING...WHICH
PRESENTS A RATHER STARK CONTRAST BETWEEN MOSTLY SUNNY SKIES IN
WEST/SOUTHWEST COUNTIES AND POTENTIALLY SOLID OVERCAST (AT LEAST
MOSTLY CLOUDY) IN EASTERN/NORTHERN ZONES. ALTHOUGH STILL SUBJECT
TO PLENTY OF ERROR...MADE VERY NOTABLE 10-12 DEGREE CUTS TO HIGH
TEMPS IN ROUGHLY THE NORTHEAST 1/2...WITH MORE MODEST CUTS UP TO
AROUND 5 DEGREES IN THE SOUTHWEST 1/2. FAR SOUTHWEST ZONES WERE
ACTUALLY CHANGED VERY LITTLE. THE NET RESULT...AT LEAST FOR
NOW...IS A HIGH TEMP FORECAST AIMING FROM UPPER 30S/LOW 40S MUCH
OF THE NORTHEAST 1/2 AND MUCH WARMER 50S TO MID-60S SOUTHWEST.
DEPENDING ON HOW THICK STRATUS AND FOG REMAINS...UPPER 30S COULD
END UP BEING OPTIMISTIC IN SOME NORTHEAST COUNTIES.
TURNING TO THIS EVENING/TONIGHT...AS TOUCHED ON ABOVE HAVE ADDED A
BASELINE PATCHY FOG MENTION TO MUCH OF THE NORTHEAST 1/2 OF THE
CWA...WHICH MAY VERY WELL NEED TO BE BEEFED UP BY NEXT FEW SHIFTS
DEPENDING ON TRENDS. ONE FACTOR HOWEVER LESS FAVORABLE FOR
WIDESPREAD DENSE FOG WILL BE INCREASING SOUTHERLY BREEZES OF
GENERALLY 15 MPH WITH HIGHER GUSTS...PICKING UP IN RESPONSE TO LOW
PRESSURE PASSING EASTWARD ACROSS THE DAKOTAS...WHILE A LOW-
AMPLITUDE MID LEVEL SHORTWAVE TROUGH FLATTENS THE RIDGE AND ENTERS
THE NORTHERN/CENTRAL PLAINS. THESE BREEZES AND THE EXPECTATION OF
PLENTY OF CLOUD COVER IN MOST AREAS SHOULD KEEP TEMPS FROM
DROPPING MUCH...AND MADE LITTLE CHANGE HERE WITH MOST PLACES INTO
THE 33-37 RANGE. PRECIP-WISE...WHILE THE VAST MAJORITY OF MID-
LEVEL SATURATION/FORCING SHOULD FOCUS ANY MEASURABLE OVERNIGHT
PRECIP SAFELY NORTH OF THE CWA NEAR AND ESPECIALLY NORTH OF THE
NEB/SD BORDER...NAM PLAN-VIEW AND FORECAST SOUNDINGS EXHIBITED
ENOUGH LOW-LEVEL SATURATION DEPTH TO AROUND 1/2-KILOMETER OR
HIGHER...ALONG WITH A TELL-TALE "SPLOTCHY LIGHT QPF" SIGNAL...TO
JUSTIFY THE AFOREMENTIONED SLIGHT CHANCE OF LIGHT DRIZZLE IN
NORTHERN ZONES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 345 AM CST MON FEB 9 2015
THE RIDGE OF HIGH PRESSURE ACROSS THE PLAINS WILL BEGIN TO BREAK
DOWN ON TUESDAY AS AN UPPER LEVEL DISTURBANCE CROSSES THE ROCKIES
AND EVENTUALLY STEERS A COLD FRONT ACROSS THE LOCAL AREA TUESDAY
NIGHT THROUGH WEDNESDAY. IN THE MEANTIME...EXPECT TUESDAY TO BE A
FAIRLY NICE DAY ACROSS THE LOCAL AREA AS A SURFACE TROUGH/WARM FRONT
WILL BE MAKING ITS WAY INTO EASTERN NEBRASKA BY LATE MORNING. WHILE
THERE IS A SMALL POTENTIAL FOR SOME FOG TO START THE DAY...WITH
WESTERLY DOWNSLOPE FLOW DEVELOPING BY MID MORNING...ANY FOG THAT
DOES MANAGE TO DEVELOP SHOULD DISSIPATE RAPIDLY DURING THE MORNING
HOURS...WITH MOSTLY SUNNY SKIES AND UNSEASONABLY WARM TEMPERATURES
BEING THE RULE BY AFTERNOON.
DURING THE EVENING HOURS TUESDAY...EXPECT A FAIRLY STRONG COLD FRONT
TO RAPIDLY DROP SOUTHWARD FROM THE NORTHERN PLAINS...REACHING
ROUGHLY THE NE/KS STATE LINES BY DAYBREAK WEDNESDAY. WITH
TEMPERATURES ALOFT EXPECTED TO DROP 10-15C BEHIND THIS FRONT...EXPECT
A NOTICEABLY COOLER DAY ON WEDNESDAY ALONG WITH SOME INCREASED
LOW/MID LEVEL CLOUD COVER. IN ADDITION TO THE ANTICIPATED
CLOUD COVER AND COOLER TEMPERATURES...BREEZY NORTHERLY WINDS BEHIND
THIS FRONT WILL LIKELY MAKE FOR A BLUSTERY DAY ACROSS THE REGION.
WHILE WINDS SHOULD LIGHTEN UP SOME THURSDAY...THE COOLER
AIRMASS IS EXPECTED TO LINGER...WITH TEMPERATURES DROPPING TO NEAR
OR POSSIBLY EVEN A TAD BELOW CLIMO BOTH THURSDAY MORNING AND
THURSDAY AFTERNOON.
THEREAFTER...WINDS ARE EXPECTED TO TURN SOUTHERLY ON FRIDAY AHEAD OF
YET ANOTHER UPPER LEVEL DISTURBANCE EMBEDDED IN NORTHWESTERLY FLOW
ALOFT THAT IS EXPECTED TO STEER A COLD FRONT ACROSS THE LOCAL AREA
OVER THE UPCOMING WEEKEND. WHILE THERE IS SOME DISCREPANCY WITH
JUST HOW COLD THIS AIRMASS WILL BE...WITH THE EC BEING ROUGHLY 10F
COOLER THAN THE GFS WITH TEMPERATURES OVER THE UPCOMING
WEEKEND...WITH THE AGREEMENT AT LEAST A MODERATELY COOLER AIRMASS
TRAVERSING THE LOCAL AREA...OPTED TO TRIM DOWN BLENDED GUIDANCE
FOR SATURDAY THROUGH SUNDAY IN COORDINATION WITH SURROUNDING
OFFICES. OTHER THAN THE FLUCTUATING TEMPERATURES...THE EXTENDED
FORECAST CONTINUES TO LOOK DRY...WITH SOME HINTS OF MOISTURE IN
EXTENDED MODELS REACHING THE LOCAL AREA POSSIBLY EARLY NEXT WEEK
AS A PACIFIC SYSTEM WORKS ITS WAY ACROSS THE INTERMOUNTAIN WEST.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1148 AM CST MON FEB 9 2015
VFR CONDITIONS CURRENTLY FORECAST FOR KEAR THROUGH THE NEXT 24
HOURS. KGRI IS A DIFFERENT STORY...WITH VLIFR CONDITIONS TO START
THE TAF PERIOD...BUT WE ARE HOLDING OUT HOPE THAT SOME IMPROVEMENT
WILL BE NOTED LATER THIS AFTERNOON. IT IS BECOMING INCREASINGLY
LIKELY THAT ANOTHER ROUND OF SUB-VFR CONDITIONS WILL BE REALIZED
TONIGHT INTO TUESDAY MORNING FOR PORTIONS OF THE REGION AS LOW
CLOUDS AND FOG ONCE AGAIN INFILTRATE THE REGION.
STRATUS...WITH A CEILING NEAR 200FT AGL...PERSISTS ACROSS MUCH OF
THE REGION AS OF THIS WRITING...AND FOG WITH VISIBILITY AT OR
BELOW 1/4SM PERSISTS ALONG THE WESTERN PERIPHERY OF THIS STRATUS.
AS A RESULT...KGRI REMAINS AT VLIFR LEVELS IN RESTRICTED
VISIBILITY AND A LOW CEILING. KEAR IS JUST FAR ENOUGH WEST AND
LUCKILY...IS CURRENTLY OBSERVING VFR CONDITIONS...A TREND WHICH IS
EXPECTED TO CONTINUE THIS AFTERNOON INTO TONIGHT. THERE IS SOME
HOPE THAT THIS FOG COULD DISSIPATE AND THE CEILING COULD INCREASE
AT KGRI LATER THIS AFTERNOON...BUT FORECAST CONFIDENCE THROUGH
SUNSET IS LOW AND MULTIPLE TAF AMENDMENTS ARE POSSIBLE. FOR NOW AT
KGRI...WENT AHEAD WITH VLIFR THROUGH 19Z...WITH PREVAILING MVFR
AND TEMPO VLIFR 19-21Z...FOLLOWED BY VFR 21-10Z...AND THEN IFR
CONDITIONS 10-15Z. FOR KEAR...KEPT VFR CONDITIONS GOING THROUGH
THE NEXT 24 HOURS...BUT THIS WILL NEED TO BE CLOSELY MONITORED IN
CASE THE STRATUS/FOG TRIES TO MAKE A PUSH FARTHER WEST THAN
CURRENTLY ANTICIPATED. THE SURFACE WIND AT BOTH TAF SITES WILL
START THE TAF PERIOD LIGHT AND VARIABLE...BUT BECOME MORE
ESTABLISHED FROM THE SOUTHEAST TONIGHT...AND MORE FROM THE
SOUTHWEST AND EVENTUALLY WEST ON TUESDAY. THERE IS AN OPPORTUNITY
FOR WEAK LOW LEVEL WIND SHEAR AT BOTH TAF SITES TONIGHT
06-12Z...BUT AT THIS TIME THIS WIND SHEAR IS EXPECTED TO REMAIN
TOO WEAK FOR INCLUSION IN EITHER TAF.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR NEZ039>041-
046>049-061>064-074>077-084>087.
KS...DENSE FOG ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR KSZ006-007-
018-019.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...ROSSI
AVIATION...BRYANT
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1115 AM CST MON FEB 9 2015
.UPDATE...
ISSUED AT 505 AM CST MON FEB 9 2015
A CAM SHOT OF A CAR TRAVELING NEAR NEWPORT INDICATES NO FOG WHICH
IS SUPPORTED BY SATELLITE SHOWING SOME EROSION ON THE WESTERN FLANK
OF THE ARCTIC FRONT. WEST WINDS AT AINSWORTH SUPPORT THIS. ROCK
COUNTY HAS BEEN REMOVED FROM THE DENSE FOG ADVISORY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM CST MON FEB 9 2015
THE ARCTIC FRONT AND FOG APPEAR TO BE STATIONARY AT 08Z. LOW
PRESSURE WILL DEEPEN ACROSS THE NRN HIGH PLAINS TODAY AND DRAW THE
FRONT WEST TOWARD HIGHWAY 83. THE HIGH TEMPERATURE FORECAST TODAY
USES THE RAP AND ARW MODELS WHICH HAVE DISPOSED OF ANY SNOW COVER
FOR HIGHS IN THE 60S WEST OF THE FRONT AND 40S EAST OF THE FRONT.
THE DENSE FOG THIS MORNING SHOULD LIFT FROM 15Z ONWARD AND
INCREASING WINDS ASSOCIATED WITH DEEPENING LOW PRESSURE SHOULD
PREVENT REDEVELOPMENT TONIGHT AS THIS LOW DROPS INTO SCNTL SD. LOWS
TONIGHT REFLECT THIS WITH 30S MOST AREAS...20S IN THE PLATTE RIVER
VALLEY CONFLUENCE.
GIVEN THE ABOVE FREEZING LOWS FORECAST TONIGHT...THE LIGHT RAIN
CHANCE NORTH OF ONEILL SHOULD NOT POSE AN ICE THREAT AND ALL MODEL
SOLNS SUGGEST THIS WILL BE THE CASE KEEPING THAT RISK WELL NORTH AND
EAST OF THE FCST AREA. STILL TEMPERATURES NORTH AND EAST OF ONEILL
ARE NEAR OR AT FREEZING SUGGESTING IT WILL BE CLOSE.
LASTLY...ALL MODELS MAINTAIN OVERCAST SKIES ALONG AND EAST OF THE
ARCTIC FRONT AND MOSTLY CLEAR SKIES WEST OF THE FRONT. A MULTI MODEL
BLEND WAS USED FOR SKY COVER TODAY AND TONIGHT WHICH LINED UP CLOSE
TO THE TEMPERATURE FORECAST PROVIDED BY THE ARW AND RAP MODELS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 356 AM CST MON FEB 9 2015
MAIN FORECAST CONCERNS THROUGH THE MID AND LONG RANGE PORTIONS OF
THE FORECAST DEAL WITH TEMPERATURES AS A PRIMARILY DRY FORECAST IS
AT HAND.
THE FORECAST MODELS ARE IN DECENT AGREEMENT THROUGHOUT THE TIME
PERIOD AS THE UPPER LEVEL PATTERN STAYS PERSISTENT WITH A LONGWAVE
TROUGH OVER THE EAST COAST AND RIDGING ACROSS THE WEST. THIS LEAVES
THE NORTHERN AND CENTRAL PLAINS UNDER THE INFLUENCE OF NORTHWEST
FLOW. THERE WILL BE SEVERAL WEAK SHORTWAVE TROUGHS THAT PASS OVER
THE LOCAL AREA...AND AS TIMING HAS IMPROVED WHEN COMPARING MODELS
HAVE HIGHER CONFIDENCE IN THEIR INFLUENCE THIS FORECAST CYCLE.
THE LARGE AND IMPRESSIVE LOOKING CYCLONE CURRENTLY OVER THE PACIFIC
NORTHWEST WILL WEAKEN OVER THE NEXT 24 HOURS AS IT MOVES FURTHER
ONSHORE AND CROSSES THE ROCKY MOUNTAINS. THIS WILL CAUSE IT TO BREAK
UP INTO SEVERAL WEAK PV ANOMALIES...WITH THE FIRST TWO PASSING
ACROSS THE NORTHERN AND CENTRAL PLAINS...WITH THE THIRD STAYING OVER
THE WESTERN CONUS...EVENTUALLY DIGGING INTO THE SOUTHWEST AND
CLOSING OFF OVER BAJA CALIFORNIA. WITH THE NORTHERN PV
ANOMALIES...THE FIRST WILL MOVE ACROSS THE CENTRAL PLAINS EARLY IN
THE DAY TUESDAY...WITH THE SECOND MOVING SOUTHEAST FROM NORTH DAKOTA
INTO IOWA TUESDAY NIGHT. THERE WILL BE ASSOCIATED SURFACE LOWS OVER
THE DAKOTAS WITH A WEAK FRONT DRAGGING ACROSS NEBRASKA THROUGH THE
DAY TUESDAY...THEN A SECOND STRONGER SURFACE COLD FRONT PASSING
ACROSS THE FORECAST AREA TUESDAY NIGHT. TEMPERATURES SHOULDN/T SEE
MUCH OF AN IMPACT FROM THE PASSAGE OF THE FIRST FRONT...HOWEVER DO
EXPECT WINDS BEHIND THE FRONT TO INCREASE A BIT AS THE BOUNDARY
LAYER MIXES. DID INCREASE HIGHS FOR TUESDAY SLIGHTLY AS THE TREND
LATELY HAS BEEN WARMER THAN THE MODELS HAVE BEEN INDICATING SO AT
LEAST PUT HIGHS NEAR THE HIGH END OF MODEL GUIDANCE. THE BETTER
CHANCES FOR WINDS TO INCREASE WILL COME BEHIND THE TUESDAY NIGHT
FRONT AS THE PRESSURE GRADIENT TIGHTENS...COLD AIR ADVECTION WILL BE
ONGOING...AND WITH UNIDIRECTIONAL WINDS GOING ALOFT AND 850MB WINDS
OF 30-40KTS IF THE BOUNDARY LAYER CAN STAY MIXED A BREEZY NIGHT WILL
BE IN STORE FOR MUCH OF THE AREA. DID LOWER LOWS TUESDAY NIGHT A FEW
DEGREES...BUT NOT SIGNIFICANTLY BECAUSE OF INCREASED CLOUD COVER AND
THE MIXED BOUNDARY LAYER...DESPITE THE COLDER AIR PUSHING IN.
WEDNESDAY SHOULD BE ANOTHER BREEZY DAY...ESPECIALLY EARLY ON. THE
PRESSURE GRADIENT WILL RELAX THROUGH THE DAY...BOTH AT THE SURFACE
AND ALOFT SO EVEN WITH GOOD MIXING OF THE BOUNDARY LAYER TO 850MB OR
800MB AS THE GFS WOULD SUGGEST WINDS WILL LIKELY DECREASE INTO THE
AFTERNOON HOURS. ALSO...TEMPERATURES WILL BE COOLER WITH NEAR NORMAL
VALUES EXPECTED. KEPT HIGHS SLIGHTLY ABOVE GUIDANCE VALUES DUE TO
TRENDS AND AS THERE SHOULD BE GOOD SUNSHINE TO HELP WARM THINGS
DURING THE DAY.
CANADIAN HIGH PRESSURE WILL BUILD INTO THE PLAINS WEDNESDAY NIGHT
AND THURSDAY BEHIND A POTENT SHORTWAVE TROUGH THAT WILL DIG
SOUTHEAST FROM THE NORTHWEST TERRITORIES INTO THE GREAT LAKES. THERE
ARE VERY SLIGHT DIFFERENCES IN THE DETAILS OF THIS SHORTWAVE...BUT
THESE DIFFERENCES WILL HAVE LITTLE IMPACT ON THE SENSIBLE WEATHER
LOCALLY. IN GENERAL...THIS SYSTEM WILL BRING A BACKDOOR COLD FRONT
ACROSS NEBRASKA WEDNESDAY NIGHT...BRINGING COOLER TEMPERATURES INTO
THE AREA. THAT BEING SAID...THE COLDEST AIR WITH 850MB TEMPERATURES
BELOW -20C WILL STAY WELL TO THE EAST OF THE AREA. LOWS WEDNESDAY
NIGHT WERE DROPPED A FEW DEGREES...WITH READINGS EXPECTED IN THE
SINGLE DIGITS AND TEENS FOR MUCH OF THE FORECAST AREA. ALSO...THE
SURFACE HIGH WILL DRIFT SOUTHEAST AND AT THIS TIME IS LOOKING TO
STAY EAST INTO THE MISSOURI AND MISSISSIPPI RIVER VALLEYS SO WILL
KEEP THE COLDEST OVERNIGHT TEMPERATURES EAST OF THE AREA.
THEN ANOTHER SHORTWAVE TROUGH WILL DIG INTO THE TROUGH ON SATURDAY.
THIS SYSTEM ORIGINATES OVER THE ARCTIC SO IT WILL HAVE COLDER AIR
YET WITH IT...BUT AS IT STAYS FAIRLY COMPACT...UNLESS THE MODELS
CHANGE TUNES AND ALLOW A TRACK FURTHER WEST...LOCAL AREAS WON/T
EXPERIENCE THE MUCH COLDER AIR. TEMPERATURES IN THE OUTER PERIODS OF
THE FORECAST WERE TRENDED COLDER FROM THE PREVIOUS
FORECAST...ESPECIALLY OVER THE EASTERN PARTS OF THE FORECAST
AREA...BECAUSE OF THE BETTER MODEL AGREEMENT WITH THESE STRONG
SYSTEMS MOVING SOUTH INTO THE TROUGH. THE WESTERN PORTIONS OF THE
FORECAST AREA MAY CONTINUE TO LIE JUST FAR ENOUGH WEST TO STAY UNDER
THE INFLUENCE OF THE RIDGE AND MAY CONTINUE TO SEE HIGHS ABOVE
NORMAL. AS MENTIONED EARLIER...THE FORECAST IS DRY THROUGH SUNDAY.
WITH EACH PASSING SHORTWAVE TROUGH...THERE WILL BE SOME ENHANCED
LIFT...BUT MOISTURE WILL BE VERY LIMITED...ESPECIALLY IN THE LOW
LEVELS AND THE SYSTEMS WILL BE MOVING QUICK ENOUGH TO DISALLOW
TOP-DOWN SATURATION FROM OCCURRING AND MAY JUST GET SOME VIRGA AT
TIMES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1114 AM CST MON FEB 9 2015
UNCERTAINTY IN THE 18Z TAF FORECAST CYCLE AS NEAR TERM GUIDANCE IS
MIXED ON THE EVENTUAL BREAK UP OF STRATUS THAT IS CURRENTLY SITUATED
ACROSS NORTH CENTRAL NEBRASKA. THE NAM MODEL CONTINUES TO BE THE
MOST BULLISH IN DEVELOPING STRATUS WEST ACROSS MUCH OF WEST
CENTRAL NEBRASKA...INCLUDING THE KLBF AND KVTN TERMINALS OVERNIGHT.
THE GFS IS SUGGESTING CLEAR SKIES BELOW 12K FEET. ATTM...DISCOUNTING
THE NAM GUIDANCE AS SOUTHWEST LOWER TROPOSPHERIC FLOW SHOULD HELP
SCOUR MOISTURE. IN ADDITION...THE MODEL SHOWED A SIMILAR WESTWARD
PROGRESSION LAST NIGHT IMPACTING KVTN AND KLBF...THIS HAS NOT
HAPPENED IN A WHILE...DESPITE SOLID SNOW MELT. FOR NOW WILL GO
WITH VFR AT BOTH TERMINALS...BUT CANNOT ENTIRE RULE OUT THAT UPDATES
MAY BE NEEDED. OTHERWISE DENSE FOG IS SHOWN TO IMPACT OUR EASTERN
TERMINALS THROUGH MUCH OF THE FORECAST PERIOD...THERE MAY BE A
BRIEF PERIOD WHERE CEILINGS LIFT AT KONL...BUT MODEL GUIDANCE
POINTS TO A QUICK RETURN OVERNIGHT...THIS MAY ALSO IMPACT THE KBBW
TERMINAL.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR NEZ006-007-
010-028-029.
&&
$$
UPDATE...CDC
SHORT TERM...CDC
LONG TERM...BROOKS
AVIATION...JACOBS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
615 AM CST MON FEB 9 2015
.UPDATE...
ISSUED AT 614 AM CST MON FEB 9 2015
PER SATELLITE TRENDS AND HRRR VISIBILITY GUIDANCE...FELT IT
PRUDENT TO ADD FRANKLIN/SMITH/OSBORNE COUNTIES TO EXISTING DENSE
FOG ADVISORY...AS THE FAR WESTERN EDGE OF STRATUS IS JUST STARTING
TO CREEP INTO THESE AREAS AND THE WORST FOG SEEMS TO BE ALONG AND
ROUGHLY 50 MILES BEHIND THE EDGE. INTERESTINGLY...THERE ARE SOME
SIGNS THAT THE WESTERN EDGE OF FOG/STRATUS MAY FINALLY BE
STALLING...AND ONCOMING DAY SHIFT WILL HAVE TO MONITOR THE
EVOLUTION OF THIS VERY SHARP EDGE TODAY...AND POTENTIALLY MAJOR
RESULTANT IMPLICATIONS FOR TEMPS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 456 AM CST MON FEB 9 2015
WHAT 24 HOURS AGO APPEARED TO BE A FAIRLY "STRAIGHTFORWARD" SHORT
TERM PERIOD WITH WELL-ABOVE AVERAGE TEMPS CWA-WIDE HAS
UNFORTUNATELY MORPHED INTO A RATHER CHALLENGING PERIOD WITH
PLENTY OF FOG (SOME DENSE) TO START OUT...THE LIKELIHOOD OF LOW
STRATUS AND POSSIBLY AT-LEAST-LIGHT FOG HANGING ON EVEN THROUGH
THIS AFTERNOON WITHIN THE NORTHEAST 1/3 TO 1/2 OF THE CWA...AND OF
COURSE THE RESULTANT FAIRLY MAJOR IMPLICATIONS ON TEMPERATURES.
THIS SETS THE STAGE FOR POSSIBLY ONE OF THE MORE CHALLENGING 1ST
PERIOD HIGH TEMP FORECASTS THIS FORECASTER HAS SEEN IN AWHILE...AS
THERE WILL EASILY BE A 20-30 DEGREE GRADIENT FROM THE
CLOUDY/CHILLIER EAST-NORTHEAST COUNTIES TO THE MOSTLY SUNNY/WARMER
WEST/SOUTHWEST COUNTIES. ACROSS A CORRIDOR THROUGH THE CENTRAL
CWA HERE THE EDGE OF THE STUBBORN STRATUS WILL LIKELY RESIDE MUCH
OF THE DAY...THERE IS EASILY 10-DEGREE TEMP BUST POTENTIAL. PUT
ANOTHER WAY...UNFORTUNATELY THOSE HOPING FOR A REALLY NICE AND AT
LEAST PARTIALLY SUNNY DAY ANYWHERE NEAR AND EAST THROUGH NORTH OF
THE TRI-CITIES WILL BE FACING A GLOOMY MONDAY LETDOWN.
NOT EVEN COUNTING THE FAIRLY SIGNIFICANT FORECAST MODIFICATIONS
MADE TO MUCH OF THE CWA FOR TODAY...THERE IS YET ANOTHER QUANDARY
REGARDING WHETHER AT LEAST LIGHT FOG WILL REALLY EVER COMPLETELY
GO AWAY ESPECIALLY WITHIN THE NORTHEAST 1/3 OF THE CWA THROUGH
THESE NEXT 24 HOURS...WITH AT LEAST SOME POSSIBILITY OF DENSE FOG
ISSUES AGAIN SHOWING THEIR HAND TONIGHT. HOWEVER...WITH STRONGER
SOUTHEAST-SOUTHERLY SURFACE BREEZES AND BOUNDARY LAYER FLOW THAN
THIS MORNING...CONFIDENCE IS NOT HIGH ENOUGH AT THIS TIME TO GO
WITH ANYTHING MORE THAN A BASELINE "PATCHY FOG" MENTION FOR
TONIGHT.
WITH EVERYTHING ELSE GOING ON...FORTUNATELY CONFIDENCE IS STILL
PRETTY HIGH IN A PRECIP-FREE 24 HOURS ACROSS THE VAST MAJORITY OF
THE CWA. THAT BEING SAID...BOTH THE 00Z/06Z NAM SUGGEST THAT LOW-
LEVEL SATURATION DEPTH/BOUNDARY LAYER MIXING COULD GET DEEP ENOUGH
OVERNIGHT TO SUPPORT AT LEAST SOME SPOTTY LIGHT DRIZZLE OVERNIGHT
MAINLY NEAR/NORTH OF NEBRASKA HIGHWAY 92 AND THIS HAS BEEN ADDED
TO THE FORECAST AS WELL. FORTUNATELY...WITH LOW TEMPS FORECAST TO
DROP NO LOWER THAN 32-34 DEGREES ACROSS THE MAJORITY OF THIS
AREA...WAS ABLE TO STEER CLEAR OF ANY LIGHT FREEZING DRIZZLE/ICING
CONCERNS.
GOING OVER THE CURRENT SITUATION AS OF 1030Z/430 AM...BROAD
SURFACE HIGH PRESSURE IS PROVIDING A VERY LIGHT/VARIABLE WIND
REGIME THIS MORNING...WHICH HAS SET THE STAGE FOR LOCALLY DENSE
FOG DEVELOPMENT ESPECIALLY ALONG AND WITHIN ROUGHLY 50 MILES
BEHIND THE LEADING EDGE OF A SOLID DECK OF LOW STRATUS WHICH HAS
STEADILY "BACK-DOORED" INTO THE CWA FROM EAST- TO-WEST SINCE LAST
EVENING BEHIND A MODEST COLD FRONT. AS OF THIS WRITING...THIS
STRATUS IS ROUGHLY BISECTING THE CWA FROM WEST- TO- EAST...WITH
WESTERN COUNTIES CLEAR AND LARGELY FOG-FREE IN SHARP CONTRAST TO
THE SITUATION FARTHER EAST. IN THE LARGER-SCALE MID- UPPER LEVEL
SCENE...YOU WOULDN/T EXPECT TO HAVE SO MANY COMPLICATIONS GOING ON
AT THE SURFACE...AS WATER VAPOR SATELLITE AND SHORT TERM MODEL
DATA REVEAL A FAIRLY BENIGN NORTHWESTERLY FLOW IN THE PRESENCE OF
BROAD SHORTWAVE RIDGING OVER THE CENTRAL PLAINS. TEMP-WISE...MOST
OF THE CWA SHOULD REALIZE OVERNIGHT LOWS IN THE 27-33 RANGE...WITH
THE LOW STRATUS OBVIOUSLY HALTING MUCH OF ANY FALL CENTRAL AND
EAST.
LOOKING AHEAD-FORECAST WISE...THE PARAMOUNT CONCERN RIGHT AWAY IS
THE ONGOING DENSE FOG ADVISORY CURRENTLY IN EFFECT FOR MOST
COUNTIES EAST-NORTHEAST OF A KEARNEY-OSBORNE LINE. TO ITS
CREDIT...THE VARIOUS OVERNIGHT HRRR VISIBILITY PRODUCT RUNS HAVE
BEEN DOING AN EXCELLENT JOB CAPTURING THE WESTWARD PROGRESSION OF
THE STRATUS AND FOG. BASED ON ITS TRENDS ALONG WITH 11-3.9 MICRON
SATELLITE...CANNOT RULE OUT A FEW MORE COUNTIES NEEDING TACKED
ONTO THE WEST SIDE OF THE EXISTING ADVISORY WITHIN THE NEXT FEW
HOURS...AND WILL KEEP AN EYE ON THINGS. AS FOR ADVISORY
TIMING...IN KEEPING IN COLLABORATION WITH SURROUNDING OFFICES THAT
ISSUED THEIR ADVISORIES FIRST...HAVE GONE WITH A 15Z/9AM
EXPIRATION TIME...BUT AM FEELING MORE AND MORE STRONGLY THAT DAY
SHIFT WILL LIKELY HAVE TO EXTEND A DECENT PORTION OF THE AREA
THROUGH AT LEAST 18Z/NOON...ESPECIALLY NEAR AND EAST-NORTHEAST OF
THE TRI- CITIES. WITH SURFACE BREEZES ONLY VERY SLOWLY PICKING UP
TODAY TO GENERALLY 10-15 MPH FROM THE SOUTHEAST...THIS HAS THE
LOOKS OF A DAY THAT COULD KEEP AT LEAST LIGHT FOG FIRMLY IN PLACE
ESSENTIALLY ALL DAY LONG IN AT LEAST A HANDFUL OF COUNTIES.
MOVING BEYOND THE OBVIOUS FOG ISSUES...THE NEXT QUESTION FOR TODAY
IS WHETHER THE LOW STRATUS WILL TRY TO BREAK UP AT ALL AND/OR
ERODE FROM SOUTHWEST-TO-NORTHEAST WITH DAYTIME HEATING. FOR
THIS...AGAIN FOLLOWED VERY CLOSE TO HRRR MODEL THINKING...WHICH
PRESENTS A RATHER STARK CONTRAST BETWEEN MOSTLY SUNNY SKIES IN
WEST/SOUTHWEST COUNTIES AND POTENTIALLY SOLID OVERCAST (AT LEAST
MOSTLY CLOUDY) IN EASTERN/NORTHERN ZONES. ALTHOUGH STILL SUBJECT
TO PLENTY OF ERROR...MADE VERY NOTABLE 10-12 DEGREE CUTS TO HIGH
TEMPS IN ROUGHLY THE NORTHEAST 1/2...WITH MORE MODEST CUTS UP TO
AROUND 5 DEGREES IN THE SOUTHWEST 1/2. FAR SOUTHWEST ZONES WERE
ACTUALLY CHANGED VERY LITTLE. THE NET RESULT...AT LEAST FOR
NOW...IS A HIGH TEMP FORECAST AIMING FROM UPPER 30S/LOW 40S MUCH
OF THE NORTHEAST 1/2 AND MUCH WARMER 50S TO MID-60S SOUTHWEST.
DEPENDING ON HOW THICK STRATUS AND FOG REMAINS...UPPER 30S COULD
END UP BEING OPTIMISTIC IN SOME NORTHEAST COUNTIES.
TURNING TO THIS EVENING/TONIGHT...AS TOUCHED ON ABOVE HAVE ADDED A
BASELINE PATCHY FOG MENTION TO MUCH OF THE NORTHEAST 1/2 OF THE
CWA...WHICH MAY VERY WELL NEED TO BE BEEFED UP BY NEXT FEW SHIFTS
DEPENDING ON TRENDS. ONE FACTOR HOWEVER LESS FAVORABLE FOR
WIDESPREAD DENSE FOG WILL BE INCREASING SOUTHERLY BREEZES OF
GENERALLY 15 MPH WITH HIGHER GUSTS...PICKING UP IN RESPONSE TO LOW
PRESSURE PASSING EASTWARD ACROSS THE DAKOTAS...WHILE A LOW-
AMPLITUDE MID LEVEL SHORTWAVE TROUGH FLATTENS THE RIDGE AND ENTERS
THE NORTHERN/CENTRAL PLAINS. THESE BREEZES AND THE EXPECTATION OF
PLENTY OF CLOUD COVER IN MOST AREAS SHOULD KEEP TEMPS FROM
DROPPING MUCH...AND MADE LITTLE CHANGE HERE WITH MOST PLACES INTO
THE 33-37 RANGE. PRECIP-WISE...WHILE THE VAST MAJORITY OF MID-
LEVEL SATURATION/FORCING SHOULD FOCUS ANY MEASURABLE OVERNIGHT
PRECIP SAFELY NORTH OF THE CWA NEAR AND ESPECIALLY NORTH OF THE
NEB/SD BORDER...NAM PLAN-VIEW AND FORECAST SOUNDINGS EXHIBITED
ENOUGH LOW-LEVEL SATURATION DEPTH TO AROUND 1/2-KILOMETER OR
HIGHER...ALONG WITH A TELL-TALE "SPLOTCHY LIGHT QPF" SIGNAL...TO
JUSTIFY THE AFOREMENTIONED SLIGHT CHANCE OF LIGHT DRIZZLE IN
NORTHERN ZONES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 345 AM CST MON FEB 9 2015
THE RIDGE OF HIGH PRESSURE ACROSS THE PLAINS WILL BEGIN TO BREAK
DOWN ON TUESDAY AS AN UPPER LEVEL DISTURBANCE CROSSES THE ROCKIES
AND EVENTUALLY STEERS A COLD FRONT ACROSS THE LOCAL AREA TUESDAY
NIGHT THROUGH WEDNESDAY. IN THE MEANTIME...EXPECT TUESDAY TO BE A
FAIRLY NICE DAY ACROSS THE LOCAL AREA AS A SURFACE TROUGH/WARM FRONT
WILL BE MAKING ITS WAY INTO EASTERN NEBRASKA BY LATE MORNING. WHILE
THERE IS A SMALL POTENTIAL FOR SOME FOG TO START THE DAY...WITH
WESTERLY DOWNSLOPE FLOW DEVELOPING BY MID MORNING...ANY FOG THAT
DOES MANAGE TO DEVELOP SHOULD DISSIPATE RAPIDLY DURING THE MORNING
HOURS...WITH MOSTLY SUNNY SKIES AND UNSEASONABLY WARM TEMPERATURES
BEING THE RULE BY AFTERNOON.
DURING THE EVENING HOURS TUESDAY...EXPECT A FAIRLY STRONG COLD FRONT
TO RAPIDLY DROP SOUTHWARD FROM THE NORTHERN PLAINS...REACHING
ROUGHLY THE NE/KS STATE LINES BY DAYBREAK WEDNESDAY. WITH
TEMPERATURES ALOFT EXPECTED TO DROP 10-15C BEHIND THIS FRONT...EXPECT
A NOTICEABLY COOLER DAY ON WEDNESDAY ALONG WITH SOME INCREASED
LOW/MID LEVEL CLOUD COVER. IN ADDITION TO THE ANTICIPATED
CLOUD COVER AND COOLER TEMPERATURES...BREEZY NORTHERLY WINDS BEHIND
THIS FRONT WILL LIKELY MAKE FOR A BLUSTERY DAY ACROSS THE REGION.
WHILE WINDS SHOULD LIGHTEN UP SOME THURSDAY...THE COOLER
AIRMASS IS EXPECTED TO LINGER...WITH TEMPERATURES DROPPING TO NEAR
OR POSSIBLY EVEN A TAD BELOW CLIMO BOTH THURSDAY MORNING AND
THURSDAY AFTERNOON.
THEREAFTER...WINDS ARE EXPECTED TO TURN SOUTHERLY ON FRIDAY AHEAD OF
YET ANOTHER UPPER LEVEL DISTURBANCE EMBEDDED IN NORTHWESTERLY FLOW
ALOFT THAT IS EXPECTED TO STEER A COLD FRONT ACROSS THE LOCAL AREA
OVER THE UPCOMING WEEKEND. WHILE THERE IS SOME DISCREPANCY WITH
JUST HOW COLD THIS AIRMASS WILL BE...WITH THE EC BEING ROUGHLY 10F
COOLER THAN THE GFS WITH TEMPERATURES OVER THE UPCOMING
WEEKEND...WITH THE AGREEMENT AT LEAST A MODERATELY COOLER AIRMASS
TRAVERSING THE LOCAL AREA...OPTED TO TRIM DOWN BLENDED GUIDANCE
FOR SATURDAY THROUGH SUNDAY IN COORDINATION WITH SURROUNDING
OFFICES. OTHER THAN THE FLUCTUATING TEMPERATURES...THE EXTENDED
FORECAST CONTINUES TO LOOK DRY...WITH SOME HINTS OF MOISTURE IN
EXTENDED MODELS REACHING THE LOCAL AREA POSSIBLY EARLY NEXT WEEK
AS A PACIFIC SYSTEM WORKS ITS WAY ACROSS THE INTERMOUNTAIN WEST.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 615 AM CST MON FEB 9 2015
AS OUTLINED IN THE PREVIOUS 06Z DISCUSSION... THIS HAS BECOME A
CONSIDERABLY MORE CHALLENGING AVIATION PERIOD THAN EXPECTED 18-24
HOURS AGO AS A BACK DOOR COLD FRONT HEADING IN FROM THE NORTHEAST
IS PROMOTING A SOLID DECK OF STRATUS/DENSE FOG AND RESULTANT
LIFR/VLIFR CONDITIONS THIS MORNING AT KGRI. GIVEN THAT THESE VERY
POOR CONDITIONS ARE ALREADY SOLIDLY IN PLACE AT KGRI...EXPECT THEM
TO CONTINUE AND ONLY SLOWLY IMPROVE THROUGH THE LATE MORNING/EARLY
AFTERNOON...AND WILL MAINTAIN A LOW-CONFIDENCE RETURN TO VFR
VISIBILITY AT 20Z WITH AN MVFR CEILING BEFORE BRINGING BACK MVFR
VISIBILITY LATER IN THE NIGHT. AS FOR KEAR...UNCERTAINTY IS OFF
THE CHARTS HERE...AS THERE ARE SIGNS THAT THE WESTERN EDGE OF
DENSE FOG/STRATUS COULD STALL WITHIN 5-10 MILES EAST OF THE
TERMINAL THIS MORNING...THUS SPARING KEAR FROM MAJOR ISSUES. AS A
RESULT...WILL HANG ONTO A FEW HOURS OF IFR VISIBILITY AND LIFR
CEILING POTENTIAL AT KEAR THIS MORNING...BUT IT COULD POSSIBLY
SKATE BY WITH VFR AS WELL AND AMENDMENTS ARE VERY POSSIBLE.
FORTUNATELY...CONFIDENCE IN SURFACE WIND IS CONSIDERABLY
HIGHER AT BOTH SITES...AS A LIGHT/VARIABLE REGIME THIS MORNING
GRADUALLY GIVES WAY TO STEADIER SOUTHEAST BREEZES THIS
AFTERNOON...WHICH THEN PICK UP EVEN MORE THIS EVENING EVENING WITH
GUST POTENTIAL 15-20KT AS DIRECTION TURNS MORE SOUTHWESTERLY LATE
IN THE PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR NEZ039>041-
046>049-061>064-074>077-084>087.
KS...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR KSZ006-007-
018-019.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...ROSSI
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
534 AM CST MON FEB 9 2015
.UPDATE...
ISSUED AT 505 AM CST MON FEB 9 2015
A CAM SHOT OF A CAR TRAVELING NEAR NEWPORT INDICATES NO FOG WHICH
IS SUPPORTED BY SATELLITE SHOWING SOME EROSION ON THE WESTERN FLANK
OF THE ARCTIC FRONT. WEST WINDS AT AINSWORTH SUPPORT THIS. ROCK
COUNTY HAS BEEN REMOVED FROM THE DENSE FOG ADVISORY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM CST MON FEB 9 2015
THE ARCTIC FRONT AND FOG APPEAR TO BE STATIONARY AT 08Z. LOW
PRESSURE WILL DEEPEN ACROSS THE NRN HIGH PLAINS TODAY AND DRAW THE
FRONT WEST TOWARD HIGHWAY 83. THE HIGH TEMPERATURE FORECAST TODAY
USES THE RAP AND ARW MODELS WHICH HAVE DISPOSED OF ANY SNOW COVER
FOR HIGHS IN THE 60S WEST OF THE FRONT AND 40S EAST OF THE FRONT.
THE DENSE FOG THIS MORNING SHOULD LIFT FROM 15Z ONWARD AND
INCREASING WINDS ASSOCIATED WITH DEEPENING LOW PRESSURE SHOULD
PREVENT REDEVELOPMENT TONIGHT AS THIS LOW DROPS INTO SCNTL SD. LOWS
TONIGHT REFLECT THIS WITH 30S MOST AREAS...20S IN THE PLATTE RIVER
VALLEY CONFLUENCE.
GIVEN THE ABOVE FREEZING LOWS FORECAST TONIGHT...THE LIGHT RAIN
CHANCE NORTH OF ONEILL SHOULD NOT POSE AN ICE THREAT AND ALL MODEL
SOLNS SUGGEST THIS WILL BE THE CASE KEEPING THAT RISK WELL NORTH AND
EAST OF THE FCST AREA. STILL TEMPERATURES NORTH AND EAST OF ONEILL
ARE NEAR OR AT FREEZING SUGGESTING IT WILL BE CLOSE.
LASTLY...ALL MODELS MAINTAIN OVERCAST SKIES ALONG AND EAST OF THE
ARCTIC FRONT AND MOSTLY CLEAR SKIES WEST OF THE FRONT. A MULTI MODEL
BLEND WAS USED FOR SKY COVER TODAY AND TONIGHT WHICH LINED UP CLOSE
TO THE TEMPERATURE FORECAST PROVIDED BY THE ARW AND RAP MODELS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 356 AM CST MON FEB 9 2015
MAIN FORECAST CONCERNS THROUGH THE MID AND LONG RANGE PORTIONS OF
THE FORECAST DEAL WITH TEMPERATURES AS A PRIMARILY DRY FORECAST IS
AT HAND.
THE FORECAST MODELS ARE IN DECENT AGREEMENT THROUGHOUT THE TIME
PERIOD AS THE UPPER LEVEL PATTERN STAYS PERSISTENT WITH A LONGWAVE
TROUGH OVER THE EAST COAST AND RIDGING ACROSS THE WEST. THIS LEAVES
THE NORTHERN AND CENTRAL PLAINS UNDER THE INFLUENCE OF NORTHWEST
FLOW. THERE WILL BE SEVERAL WEAK SHORTWAVE TROUGHS THAT PASS OVER
THE LOCAL AREA...AND AS TIMING HAS IMPROVED WHEN COMPARING MODELS
HAVE HIGHER CONFIDENCE IN THEIR INFLUENCE THIS FORECAST CYCLE.
THE LARGE AND IMPRESSIVE LOOKING CYCLONE CURRENTLY OVER THE PACIFIC
NORTHWEST WILL WEAKEN OVER THE NEXT 24 HOURS AS IT MOVES FURTHER
ONSHORE AND CROSSES THE ROCKY MOUNTAINS. THIS WILL CAUSE IT TO BREAK
UP INTO SEVERAL WEAK PV ANOMALIES...WITH THE FIRST TWO PASSING
ACROSS THE NORTHERN AND CENTRAL PLAINS...WITH THE THIRD STAYING OVER
THE WESTERN CONUS...EVENTUALLY DIGGING INTO THE SOUTHWEST AND
CLOSING OFF OVER BAJA CALIFORNIA. WITH THE NORTHERN PV
ANOMALIES...THE FIRST WILL MOVE ACROSS THE CENTRAL PLAINS EARLY IN
THE DAY TUESDAY...WITH THE SECOND MOVING SOUTHEAST FROM NORTH DAKOTA
INTO IOWA TUESDAY NIGHT. THERE WILL BE ASSOCIATED SURFACE LOWS OVER
THE DAKOTAS WITH A WEAK FRONT DRAGGING ACROSS NEBRASKA THROUGH THE
DAY TUESDAY...THEN A SECOND STRONGER SURFACE COLD FRONT PASSING
ACROSS THE FORECAST AREA TUESDAY NIGHT. TEMPERATURES SHOULDN/T SEE
MUCH OF AN IMPACT FROM THE PASSAGE OF THE FIRST FRONT...HOWEVER DO
EXPECT WINDS BEHIND THE FRONT TO INCREASE A BIT AS THE BOUNDARY
LAYER MIXES. DID INCREASE HIGHS FOR TUESDAY SLIGHTLY AS THE TREND
LATELY HAS BEEN WARMER THAN THE MODELS HAVE BEEN INDICATING SO AT
LEAST PUT HIGHS NEAR THE HIGH END OF MODEL GUIDANCE. THE BETTER
CHANCES FOR WINDS TO INCREASE WILL COME BEHIND THE TUESDAY NIGHT
FRONT AS THE PRESSURE GRADIENT TIGHTENS...COLD AIR ADVECTION WILL BE
ONGOING...AND WITH UNIDIRECTIONAL WINDS GOING ALOFT AND 850MB WINDS
OF 30-40KTS IF THE BOUNDARY LAYER CAN STAY MIXED A BREEZY NIGHT WILL
BE IN STORE FOR MUCH OF THE AREA. DID LOWER LOWS TUESDAY NIGHT A FEW
DEGREES...BUT NOT SIGNIFICANTLY BECAUSE OF INCREASED CLOUD COVER AND
THE MIXED BOUNDARY LAYER...DESPITE THE COLDER AIR PUSHING IN.
WEDNESDAY SHOULD BE ANOTHER BREEZY DAY...ESPECIALLY EARLY ON. THE
PRESSURE GRADIENT WILL RELAX THROUGH THE DAY...BOTH AT THE SURFACE
AND ALOFT SO EVEN WITH GOOD MIXING OF THE BOUNDARY LAYER TO 850MB OR
800MB AS THE GFS WOULD SUGGEST WINDS WILL LIKELY DECREASE INTO THE
AFTERNOON HOURS. ALSO...TEMPERATURES WILL BE COOLER WITH NEAR NORMAL
VALUES EXPECTED. KEPT HIGHS SLIGHTLY ABOVE GUIDANCE VALUES DUE TO
TRENDS AND AS THERE SHOULD BE GOOD SUNSHINE TO HELP WARM THINGS
DURING THE DAY.
CANADIAN HIGH PRESSURE WILL BUILD INTO THE PLAINS WEDNESDAY NIGHT
AND THURSDAY BEHIND A POTENT SHORTWAVE TROUGH THAT WILL DIG
SOUTHEAST FROM THE NORTHWEST TERRITORIES INTO THE GREAT LAKES. THERE
ARE VERY SLIGHT DIFFERENCES IN THE DETAILS OF THIS SHORTWAVE...BUT
THESE DIFFERENCES WILL HAVE LITTLE IMPACT ON THE SENSIBLE WEATHER
LOCALLY. IN GENERAL...THIS SYSTEM WILL BRING A BACKDOOR COLD FRONT
ACROSS NEBRASKA WEDNESDAY NIGHT...BRINGING COOLER TEMPERATURES INTO
THE AREA. THAT BEING SAID...THE COLDEST AIR WITH 850MB TEMPERATURES
BELOW -20C WILL STAY WELL TO THE EAST OF THE AREA. LOWS WEDNESDAY
NIGHT WERE DROPPED A FEW DEGREES...WITH READINGS EXPECTED IN THE
SINGLE DIGITS AND TEENS FOR MUCH OF THE FORECAST AREA. ALSO...THE
SURFACE HIGH WILL DRIFT SOUTHEAST AND AT THIS TIME IS LOOKING TO
STAY EAST INTO THE MISSOURI AND MISSISSIPPI RIVER VALLEYS SO WILL
KEEP THE COLDEST OVERNIGHT TEMPERATURES EAST OF THE AREA.
THEN ANOTHER SHORTWAVE TROUGH WILL DIG INTO THE TROUGH ON SATURDAY.
THIS SYSTEM ORIGINATES OVER THE ARCTIC SO IT WILL HAVE COLDER AIR
YET WITH IT...BUT AS IT STAYS FAIRLY COMPACT...UNLESS THE MODELS
CHANGE TUNES AND ALLOW A TRACK FURTHER WEST...LOCAL AREAS WON/T
EXPERIENCE THE MUCH COLDER AIR. TEMPERATURES IN THE OUTER PERIODS OF
THE FORECAST WERE TRENDED COLDER FROM THE PREVIOUS
FORECAST...ESPECIALLY OVER THE EASTERN PARTS OF THE FORECAST
AREA...BECAUSE OF THE BETTER MODEL AGREEMENT WITH THESE STRONG
SYSTEMS MOVING SOUTH INTO THE TROUGH. THE WESTERN PORTIONS OF THE
FORECAST AREA MAY CONTINUE TO LIE JUST FAR ENOUGH WEST TO STAY UNDER
THE INFLUENCE OF THE RIDGE AND MAY CONTINUE TO SEE HIGHS ABOVE
NORMAL. AS MENTIONED EARLIER...THE FORECAST IS DRY THROUGH SUNDAY.
WITH EACH PASSING SHORTWAVE TROUGH...THERE WILL BE SOME ENHANCED
LIFT...BUT MOISTURE WILL BE VERY LIMITED...ESPECIALLY IN THE LOW
LEVELS AND THE SYSTEMS WILL BE MOVING QUICK ENOUGH TO DISALLOW
TOP-DOWN SATURATION FROM OCCURRING AND MAY JUST GET SOME VIRGA AT
TIMES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 533 AM CST MON FEB 9 2015
THE LIFR CIGS AND VSBY ALONG HIGHWAY 281 IS EXPECTED TO IMPROVE TO
IFR/MVFR CIGS AROUND 18Z. THESE LOW CLOUDS MAY GET SWEPT WEST
TOWARD KANW-KVTN THIS AFTN AS LOW PRESSURE DEEPENS ACROSS SD.
EITHER WAY...IFR/MVFR CIGS ARE EXPECTED TO CONTINUE ALONG 281
THIS AFTN AND TONIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR NEZ006-007-
010-028-029.
&&
$$
UPDATE...CDC
SHORT TERM...CDC
LONG TERM...BROOKS
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
505 AM CST MON FEB 9 2015
.UPDATE...
ISSUED AT 505 AM CST MON FEB 9 2015
A CAM SHOT OF A CAR TRAVELING NEAR NEWPORT INDICATES NO FOG WHICH
IS SUPPORTED BY SATELLITE SHOWING SOME EROSION ON THE WESTERN FLANK
OF THE ARCTIC FRONT. WEST WINDS AT AINSWORTH SUPPORT THIS. ROCK
COUNTY HAS BEEN REMOVED FROM THE DENSE FOG ADVISORY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM CST MON FEB 9 2015
THE ARCTIC FRONT AND FOG APPEAR TO BE STATIONARY AT 08Z. LOW
PRESSURE WILL DEEPEN ACROSS THE NRN HIGH PLAINS TODAY AND DRAW THE
FRONT WEST TOWARD HIGHWAY 83. THE HIGH TEMPERATURE FORECAST TODAY
USES THE RAP AND ARW MODELS WHICH HAVE DISPOSED OF ANY SNOW COVER
FOR HIGHS IN THE 60S WEST OF THE FRONT AND 40S EAST OF THE FRONT.
THE DENSE FOG THIS MORNING SHOULD LIFT FROM 15Z ONWARD AND
INCREASING WINDS ASSOCIATED WITH DEEPENING LOW PRESSURE SHOULD
PREVENT REDEVELOPMENT TONIGHT AS THIS LOW DROPS INTO SCNTL SD. LOWS
TONIGHT REFLECT THIS WITH 30S MOST AREAS...20S IN THE PLATTE RIVER
VALLEY CONFLUENCE.
GIVEN THE ABOVE FREEZING LOWS FORECAST TONIGHT...THE LIGHT RAIN
CHANCE NORTH OF ONEILL SHOULD NOT POSE AN ICE THREAT AND ALL MODEL
SOLNS SUGGEST THIS WILL BE THE CASE KEEPING THAT RISK WELL NORTH AND
EAST OF THE FCST AREA. STILL TEMPERATURES NORTH AND EAST OF ONEILL
ARE NEAR OR AT FREEZING SUGGESTING IT WILL BE CLOSE.
LASTLY...ALL MODELS MAINTAIN OVERCAST SKIES ALONG AND EAST OF THE
ARCTIC FRONT AND MOSTLY CLEAR SKIES WEST OF THE FRONT. A MULTI MODEL
BLEND WAS USED FOR SKY COVER TODAY AND TONIGHT WHICH LINED UP CLOSE
TO THE TEMPERATURE FORECAST PROVIDED BY THE ARW AND RAP MODELS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 356 AM CST MON FEB 9 2015
MAIN FORECAST CONCERNS THROUGH THE MID AND LONG RANGE PORTIONS OF
THE FORECAST DEAL WITH TEMPERATURES AS A PRIMARILY DRY FORECAST IS
AT HAND.
THE FORECAST MODELS ARE IN DECENT AGREEMENT THROUGHOUT THE TIME
PERIOD AS THE UPPER LEVEL PATTERN STAYS PERSISTENT WITH A LONGWAVE
TROUGH OVER THE EAST COAST AND RIDGING ACROSS THE WEST. THIS LEAVES
THE NORTHERN AND CENTRAL PLAINS UNDER THE INFLUENCE OF NORTHWEST
FLOW. THERE WILL BE SEVERAL WEAK SHORTWAVE TROUGHS THAT PASS OVER
THE LOCAL AREA...AND AS TIMING HAS IMPROVED WHEN COMPARING MODELS
HAVE HIGHER CONFIDENCE IN THEIR INFLUENCE THIS FORECAST CYCLE.
THE LARGE AND IMPRESSIVE LOOKING CYCLONE CURRENTLY OVER THE PACIFIC
NORTHWEST WILL WEAKEN OVER THE NEXT 24 HOURS AS IT MOVES FURTHER
ONSHORE AND CROSSES THE ROCKY MOUNTAINS. THIS WILL CAUSE IT TO BREAK
UP INTO SEVERAL WEAK PV ANOMALIES...WITH THE FIRST TWO PASSING
ACROSS THE NORTHERN AND CENTRAL PLAINS...WITH THE THIRD STAYING OVER
THE WESTERN CONUS...EVENTUALLY DIGGING INTO THE SOUTHWEST AND
CLOSING OFF OVER BAJA CALIFORNIA. WITH THE NORTHERN PV
ANOMALIES...THE FIRST WILL MOVE ACROSS THE CENTRAL PLAINS EARLY IN
THE DAY TUESDAY...WITH THE SECOND MOVING SOUTHEAST FROM NORTH DAKOTA
INTO IOWA TUESDAY NIGHT. THERE WILL BE ASSOCIATED SURFACE LOWS OVER
THE DAKOTAS WITH A WEAK FRONT DRAGGING ACROSS NEBRASKA THROUGH THE
DAY TUESDAY...THEN A SECOND STRONGER SURFACE COLD FRONT PASSING
ACROSS THE FORECAST AREA TUESDAY NIGHT. TEMPERATURES SHOULDN/T SEE
MUCH OF AN IMPACT FROM THE PASSAGE OF THE FIRST FRONT...HOWEVER DO
EXPECT WINDS BEHIND THE FRONT TO INCREASE A BIT AS THE BOUNDARY
LAYER MIXES. DID INCREASE HIGHS FOR TUESDAY SLIGHTLY AS THE TREND
LATELY HAS BEEN WARMER THAN THE MODELS HAVE BEEN INDICATING SO AT
LEAST PUT HIGHS NEAR THE HIGH END OF MODEL GUIDANCE. THE BETTER
CHANCES FOR WINDS TO INCREASE WILL COME BEHIND THE TUESDAY NIGHT
FRONT AS THE PRESSURE GRADIENT TIGHTENS...COLD AIR ADVECTION WILL BE
ONGOING...AND WITH UNIDIRECTIONAL WINDS GOING ALOFT AND 850MB WINDS
OF 30-40KTS IF THE BOUNDARY LAYER CAN STAY MIXED A BREEZY NIGHT WILL
BE IN STORE FOR MUCH OF THE AREA. DID LOWER LOWS TUESDAY NIGHT A FEW
DEGREES...BUT NOT SIGNIFICANTLY BECAUSE OF INCREASED CLOUD COVER AND
THE MIXED BOUNDARY LAYER...DESPITE THE COLDER AIR PUSHING IN.
WEDNESDAY SHOULD BE ANOTHER BREEZY DAY...ESPECIALLY EARLY ON. THE
PRESSURE GRADIENT WILL RELAX THROUGH THE DAY...BOTH AT THE SURFACE
AND ALOFT SO EVEN WITH GOOD MIXING OF THE BOUNDARY LAYER TO 850MB OR
800MB AS THE GFS WOULD SUGGEST WINDS WILL LIKELY DECREASE INTO THE
AFTERNOON HOURS. ALSO...TEMPERATURES WILL BE COOLER WITH NEAR NORMAL
VALUES EXPECTED. KEPT HIGHS SLIGHTLY ABOVE GUIDANCE VALUES DUE TO
TRENDS AND AS THERE SHOULD BE GOOD SUNSHINE TO HELP WARM THINGS
DURING THE DAY.
CANADIAN HIGH PRESSURE WILL BUILD INTO THE PLAINS WEDNESDAY NIGHT
AND THURSDAY BEHIND A POTENT SHORTWAVE TROUGH THAT WILL DIG
SOUTHEAST FROM THE NORTHWEST TERRITORIES INTO THE GREAT LAKES. THERE
ARE VERY SLIGHT DIFFERENCES IN THE DETAILS OF THIS SHORTWAVE...BUT
THESE DIFFERENCES WILL HAVE LITTLE IMPACT ON THE SENSIBLE WEATHER
LOCALLY. IN GENERAL...THIS SYSTEM WILL BRING A BACKDOOR COLD FRONT
ACROSS NEBRASKA WEDNESDAY NIGHT...BRINGING COOLER TEMPERATURES INTO
THE AREA. THAT BEING SAID...THE COLDEST AIR WITH 850MB TEMPERATURES
BELOW -20C WILL STAY WELL TO THE EAST OF THE AREA. LOWS WEDNESDAY
NIGHT WERE DROPPED A FEW DEGREES...WITH READINGS EXPECTED IN THE
SINGLE DIGITS AND TEENS FOR MUCH OF THE FORECAST AREA. ALSO...THE
SURFACE HIGH WILL DRIFT SOUTHEAST AND AT THIS TIME IS LOOKING TO
STAY EAST INTO THE MISSOURI AND MISSISSIPPI RIVER VALLEYS SO WILL
KEEP THE COLDEST OVERNIGHT TEMPERATURES EAST OF THE AREA.
THEN ANOTHER SHORTWAVE TROUGH WILL DIG INTO THE TROUGH ON SATURDAY.
THIS SYSTEM ORIGINATES OVER THE ARCTIC SO IT WILL HAVE COLDER AIR
YET WITH IT...BUT AS IT STAYS FAIRLY COMPACT...UNLESS THE MODELS
CHANGE TUNES AND ALLOW A TRACK FURTHER WEST...LOCAL AREAS WON/T
EXPERIENCE THE MUCH COLDER AIR. TEMPERATURES IN THE OUTER PERIODS OF
THE FORECAST WERE TRENDED COLDER FROM THE PREVIOUS
FORECAST...ESPECIALLY OVER THE EASTERN PARTS OF THE FORECAST
AREA...BECAUSE OF THE BETTER MODEL AGREEMENT WITH THESE STRONG
SYSTEMS MOVING SOUTH INTO THE TROUGH. THE WESTERN PORTIONS OF THE
FORECAST AREA MAY CONTINUE TO LIE JUST FAR ENOUGH WEST TO STAY UNDER
THE INFLUENCE OF THE RIDGE AND MAY CONTINUE TO SEE HIGHS ABOVE
NORMAL. AS MENTIONED EARLIER...THE FORECAST IS DRY THROUGH SUNDAY.
WITH EACH PASSING SHORTWAVE TROUGH...THERE WILL BE SOME ENHANCED
LIFT...BUT MOISTURE WILL BE VERY LIMITED...ESPECIALLY IN THE LOW
LEVELS AND THE SYSTEMS WILL BE MOVING QUICK ENOUGH TO DISALLOW
TOP-DOWN SATURATION FROM OCCURRING AND MAY JUST GET SOME VIRGA AT
TIMES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1149 PM CST SUN FEB 8 2015
BACK DOOR COLD FRONT BRINGING VLIFR CONDITIONS /STRATUS AND FOG/
TO PORTIONS OF NORTH CENTRAL NEBRASKA THROUGH MID MORNING. AT
THIS TIME NEAR TERM MODELS STALL THE FRONT NEAR AN KANW TO KBBW
LINE...THUS DO NOT HAVE A MENTION IN EITHER KLBF OR KVTN TERMINAL
FORECASTS. THIS WILL NEED TO BE MONITORED CLOSELY...OTHERWISE VFR
WITH SOME PASSING HIGH CLOUDS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR NEZ006-007-
010-028-029.
&&
$$
UPDATE...CDC
SHORT TERM...CDC
LONG TERM...BROOKS
AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS HASTINGS NE
456 AM CST MON FEB 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 456 AM CST MON FEB 9 2015
WHAT 24 HOURS AGO APPEARED TO BE A FAIRLY "STRAIGHTFORWARD" SHORT
TERM PERIOD WITH WELL-ABOVE AVERAGE TEMPS CWA-WIDE HAS
UNFORTUNATELY MORPHED INTO A RATHER CHALLENGING PERIOD WITH
PLENTY OF FOG (SOME DENSE) TO START OUT...THE LIKELIHOOD OF LOW
STRATUS AND POSSIBLY AT-LEAST-LIGHT FOG HANGING ON EVEN THROUGH
THIS AFTERNOON WITHIN THE NORTHEAST 1/3 TO 1/2 OF THE CWA...AND OF
COURSE THE RESULTANT FAIRLY MAJOR IMPLICATIONS ON TEMPERATURES.
THIS SETS THE STAGE FOR POSSIBLY ONE OF THE MORE CHALLENGING 1ST
PERIOD HIGH TEMP FORECASTS THIS FORECASTER HAS SEEN IN AWHILE...AS
THERE WILL EASILY BE A 20-30 DEGREE GRADIENT FROM THE
CLOUDY/CHILLIER EAST-NORTHEAST COUNTIES TO THE MOSTLY SUNNY/WARMER
WEST/SOUTHWEST COUNTIES. ACROSS A CORRIDOR THROUGH THE CENTRAL
CWA HERE THE EDGE OF THE STUBBORN STRATUS WILL LIKELY RESIDE MUCH
OF THE DAY...THERE IS EASILY 10-DEGREE TEMP BUST POTENTIAL. PUT
ANOTHER WAY...UNFORTUNATELY THOSE HOPING FOR A REALLY NICE AND AT
LEAST PARTIALLY SUNNY DAY ANYWHERE NEAR AND EAST THROUGH NORTH OF
THE TRI-CITIES WILL BE FACING A GLOOMY MONDAY LETDOWN.
NOT EVEN COUNTING THE FAIRLY SIGNIFICANT FORECAST MODIFICATIONS
MADE TO MUCH OF THE CWA FOR TODAY...THERE IS YET ANOTHER QUANDARY
REGARDING WHETHER AT LEAST LIGHT FOG WILL REALLY EVER COMPLETELY
GO AWAY ESPECIALLY WITHIN THE NORTHEAST 1/3 OF THE CWA THROUGH
THESE NEXT 24 HOURS...WITH AT LEAST SOME POSSIBILITY OF DENSE FOG
ISSUES AGAIN SHOWING THEIR HAND TONIGHT. HOWEVER...WITH STRONGER
SOUTHEAST-SOUTHERLY SURFACE BREEZES AND BOUNDARY LAYER FLOW THAN
THIS MORNING...CONFIDENCE IS NOT HIGH ENOUGH AT THIS TIME TO GO
WITH ANYTHING MORE THAN A BASELINE "PATCHY FOG" MENTION FOR
TONIGHT.
WITH EVERYTHING ELSE GOING ON...FORTUNATELY CONFIDENCE IS STILL
PRETTY HIGH IN A PRECIP-FREE 24 HOURS ACROSS THE VAST MAJORITY OF
THE CWA. THAT BEING SAID...BOTH THE 00Z/06Z NAM SUGGEST THAT LOW-
LEVEL SATURATION DEPTH/BOUNDARY LAYER MIXING COULD GET DEEP ENOUGH
OVERNIGHT TO SUPPORT AT LEAST SOME SPOTTY LIGHT DRIZZLE OVERNIGHT
MAINLY NEAR/NORTH OF NEBRASKA HIGHWAY 92 AND THIS HAS BEEN ADDED
TO THE FORECAST AS WELL. FORTUNATELY...WITH LOW TEMPS FORECAST TO
DROP NO LOWER THAN 32-34 DEGREES ACROSS THE MAJORITY OF THIS
AREA...WAS ABLE TO STEER CLEAR OF ANY LIGHT FREEZING DRIZZLE/ICING
CONCERNS.
GOING OVER THE CURRENT SITUATION AS OF 1030Z/430 AM...BROAD
SURFACE HIGH PRESSURE IS PROVIDING A VERY LIGHT/VARIABLE WIND
REGIME THIS MORNING...WHICH HAS SET THE STAGE FOR LOCALLY DENSE
FOG DEVELOPMENT ESPECIALLY ALONG AND WITHIN ROUGHLY 50 MILES
BEHIND THE LEADING EDGE OF A SOLID DECK OF LOW STRATUS WHICH HAS
STEADILY "BACK-DOORED" INTO THE CWA FROM EAST- TO-WEST SINCE LAST
EVENING BEHIND A MODEST COLD FRONT. AS OF THIS WRITING...THIS
STRATUS IS ROUGHLY BISECTING THE CWA FROM WEST- TO- EAST...WITH
WESTERN COUNTIES CLEAR AND LARGELY FOG-FREE IN SHARP CONTRAST TO
THE SITUATION FARTHER EAST. IN THE LARGER-SCALE MID- UPPER LEVEL
SCENE...YOU WOULDN/T EXPECT TO HAVE SO MANY COMPLICATIONS GOING ON
AT THE SURFACE...AS WATER VAPOR SATELLITE AND SHORT TERM MODEL
DATA REVEAL A FAIRLY BENIGN NORTHWESTERLY FLOW IN THE PRESENCE OF
BROAD SHORTWAVE RIDGING OVER THE CENTRAL PLAINS. TEMP-WISE...MOST
OF THE CWA SHOULD REALIZE OVERNIGHT LOWS IN THE 27-33 RANGE...WITH
THE LOW STRATUS OBVIOUSLY HALTING MUCH OF ANY FALL CENTRAL AND
EAST.
LOOKING AHEAD-FORECAST WISE...THE PARAMOUNT CONCERN RIGHT AWAY IS
THE ONGOING DENSE FOG ADVISORY CURRENTLY IN EFFECT FOR MOST
COUNTIES EAST-NORTHEAST OF A KEARNEY-OSBORNE LINE. TO ITS
CREDIT...THE VARIOUS OVERNIGHT HRRR VISIBILITY PRODUCT RUNS HAVE
BEEN DOING AN EXCELLENT JOB CAPTURING THE WESTWARD PROGRESSION OF
THE STRATUS AND FOG. BASED ON ITS TRENDS ALONG WITH 11-3.9 MICRON
SATELLITE...CANNOT RULE OUT A FEW MORE COUNTIES NEEDING TACKED
ONTO THE WEST SIDE OF THE EXISTING ADVISORY WITHIN THE NEXT FEW
HOURS...AND WILL KEEP AN EYE ON THINGS. AS FOR ADVISORY
TIMING...IN KEEPING IN COLLABORATION WITH SURROUNDING OFFICES THAT
ISSUED THEIR ADVISORIES FIRST...HAVE GONE WITH A 15Z/9AM
EXPIRATION TIME...BUT AM FEELING MORE AND MORE STRONGLY THAT DAY
SHIFT WILL LIKELY HAVE TO EXTEND A DECENT PORTION OF THE AREA
THROUGH AT LEAST 18Z/NOON...ESPECIALLY NEAR AND EAST-NORTHEAST OF
THE TRI- CITIES. WITH SURFACE BREEZES ONLY VERY SLOWLY PICKING UP
TODAY TO GENERALLY 10-15 MPH FROM THE SOUTHEAST...THIS HAS THE
LOOKS OF A DAY THAT COULD KEEP AT LEAST LIGHT FOG FIRMLY IN PLACE
ESSENTIALLY ALL DAY LONG IN AT LEAST A HANDFUL OF COUNTIES.
MOVING BEYOND THE OBVIOUS FOG ISSUES...THE NEXT QUESTION FOR TODAY
IS WHETHER THE LOW STRATUS WILL TRY TO BREAK UP AT ALL AND/OR
ERODE FROM SOUTHWEST-TO-NORTHEAST WITH DAYTIME HEATING. FOR
THIS...AGAIN FOLLOWED VERY CLOSE TO HRRR MODEL THINKING...WHICH
PRESENTS A RATHER STARK CONTRAST BETWEEN MOSTLY SUNNY SKIES IN
WEST/SOUTHWEST COUNTIES AND POTENTIALLY SOLID OVERCAST (AT LEAST
MOSTLY CLOUDY) IN EASTERN/NORTHERN ZONES. ALTHOUGH STILL SUBJECT
TO PLENTY OF ERROR...MADE VERY NOTABLE 10-12 DEGREE CUTS TO HIGH
TEMPS IN ROUGHLY THE NORTHEAST 1/2...WITH MORE MODEST CUTS UP TO
AROUND 5 DEGREES IN THE SOUTHWEST 1/2. FAR SOUTHWEST ZONES WERE
ACTUALLY CHANGED VERY LITTLE. THE NET RESULT...AT LEAST FOR
NOW...IS A HIGH TEMP FORECAST AIMING FROM UPPER 30S/LOW 40S MUCH
OF THE NORTHEAST 1/2 AND MUCH WARMER 50S TO MID-60S SOUTHWEST.
DEPENDING ON HOW THICK STRATUS AND FOG REMAINS...UPPER 30S COULD
END UP BEING OPTIMISTIC IN SOME NORTHEAST COUNTIES.
TURNING TO THIS EVENING/TONIGHT...AS TOUCHED ON ABOVE HAVE ADDED A
BASELINE PATCHY FOG MENTION TO MUCH OF THE NORTHEAST 1/2 OF THE
CWA...WHICH MAY VERY WELL NEED TO BE BEEFED UP BY NEXT FEW SHIFTS
DEPENDING ON TRENDS. ONE FACTOR HOWEVER LESS FAVORABLE FOR
WIDESPREAD DENSE FOG WILL BE INCREASING SOUTHERLY BREEZES OF
GENERALLY 15 MPH WITH HIGHER GUSTS...PICKING UP IN RESPONSE TO LOW
PRESSURE PASSING EASTWARD ACROSS THE DAKOTAS...WHILE A LOW-
AMPLITUDE MID LEVEL SHORTWAVE TROUGH FLATTENS THE RIDGE AND ENTERS
THE NORTHERN/CENTRAL PLAINS. THESE BREEZES AND THE EXPECTATION OF
PLENTY OF CLOUD COVER IN MOST AREAS SHOULD KEEP TEMPS FROM
DROPPING MUCH...AND MADE LITTLE CHANGE HERE WITH MOST PLACES INTO
THE 33-37 RANGE. PRECIP-WISE...WHILE THE VAST MAJORITY OF MID-
LEVEL SATURATION/FORCING SHOULD FOCUS ANY MEASURABLE OVERNIGHT
PRECIP SAFELY NORTH OF THE CWA NEAR AND ESPECIALLY NORTH OF THE
NEB/SD BORDER...NAM PLAN-VIEW AND FORECAST SOUNDINGS EXHIBITED
ENOUGH LOW-LEVEL SATURATION DEPTH TO AROUND 1/2-KILOMETER OR
HIGHER...ALONG WITH A TELL-TALE "SPLOTCHY LIGHT QPF" SIGNAL...TO
JUSTIFY THE AFOREMENTIONED SLIGHT CHANCE OF LIGHT DRIZZLE IN
NORTHERN ZONES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 345 AM CST MON FEB 9 2015
THE RIDGE OF HIGH PRESSURE ACROSS THE PLAINS WILL BEGIN TO BREAK
DOWN ON TUESDAY AS AN UPPER LEVEL DISTURBANCE CROSSES THE ROCKIES
AND EVENTUALLY STEERS A COLD FRONT ACROSS THE LOCAL AREA TUESDAY
NIGHT THROUGH WEDNESDAY. IN THE MEANTIME...EXPECT TUESDAY TO BE A
FAIRLY NICE DAY ACROSS THE LOCAL AREA AS A SURFACE TROUGH/WARM FRONT
WILL BE MAKING ITS WAY INTO EASTERN NEBRASKA BY LATE MORNING. WHILE
THERE IS A SMALL POTENTIAL FOR SOME FOG TO START THE DAY...WITH
WESTERLY DOWNSLOPE FLOW DEVELOPING BY MID MORNING...ANY FOG THAT
DOES MANAGE TO DEVELOP SHOULD DISSIPATE RAPIDLY DURING THE MORNING
HOURS...WITH MOSTLY SUNNY SKIES AND UNSEASONABLY WARM TEMPERATURES
BEING THE RULE BY AFTERNOON.
DURING THE EVENING HOURS TUESDAY...EXPECT A FAIRLY STRONG COLD FRONT
TO RAPIDLY DROP SOUTHWARD FROM THE NORTHERN PLAINS...REACHING
ROUGHLY THE NE/KS STATE LINES BY DAYBREAK WEDNESDAY. WITH
TEMPERATURES ALOFT EXPECTED TO DROP 10-15C BEHIND THIS FRONT...EXPECT
A NOTICEABLY COOLER DAY ON WEDNESDAY ALONG WITH SOME INCREASED
LOW/MID LEVEL CLOUD COVER. IN ADDITION TO THE ANTICIPATED
CLOUD COVER AND COOLER TEMPERATURES...BREEZY NORTHERLY WINDS BEHIND
THIS FRONT WILL LIKELY MAKE FOR A BLUSTERY DAY ACROSS THE REGION.
WHILE WINDS SHOULD LIGHTEN UP SOME THURSDAY...THE COOLER
AIRMASS IS EXPECTED TO LINGER...WITH TEMPERATURES DROPPING TO NEAR
OR POSSIBLY EVEN A TAD BELOW CLIMO BOTH THURSDAY MORNING AND
THURSDAY AFTERNOON.
THEREAFTER...WINDS ARE EXPECTED TO TURN SOUTHERLY ON FRIDAY AHEAD OF
YET ANOTHER UPPER LEVEL DISTURBANCE EMBEDDED IN NORTHWESTERLY FLOW
ALOFT THAT IS EXPECTED TO STEER A COLD FRONT ACROSS THE LOCAL AREA
OVER THE UPCOMING WEEKEND. WHILE THERE IS SOME DISCREPANCY WITH
JUST HOW COLD THIS AIRMASS WILL BE...WITH THE EC BEING ROUGHLY 10F
COOLER THAN THE GFS WITH TEMPERATURES OVER THE UPCOMING
WEEKEND...WITH THE AGREEMENT AT LEAST A MODERATELY COOLER AIRMASS
TRAVERSING THE LOCAL AREA...OPTED TO TRIM DOWN BLENDED GUIDANCE
FOR SATURDAY THROUGH SUNDAY IN COORDINATION WITH SURROUNDING
OFFICES. OTHER THAN THE FLUCTUATING TEMPERATURES...THE EXTENDED
FORECAST CONTINUES TO LOOK DRY...WITH SOME HINTS OF MOISTURE IN
EXTENDED MODELS REACHING THE LOCAL AREA POSSIBLY EARLY NEXT WEEK
AS A PACIFIC SYSTEM WORKS ITS WAY ACROSS THE INTERMOUNTAIN WEST.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1247 AM CST MON FEB 9 2015
SORRY FOR THE LATE 06Z DISCUSSION...BUT AS COVERED IN PREVIOUS 00Z
DISCUSSION THIS HAS BECOME A CONSIDERABLY MORE PESSIMISTIC
AVIATION PERIOD THAN EXPECTED EVEN 12 HOURS AGO AS A BACK DOOR
COLD FRONT HEADING IN FROM THE NORTHEAST IS PROMOTING A SOLID DECK
OF INCOMING IFR STRATUS AND LIKELY A MULTI-HOUR PERIOD OF
VISIBILITY RANGING ANYWHERE FROM LIFR TO MVFR...WITH A PERIOD OF
DENSE FOG VLIFR NOT OUT OF THE QUESTION. WHILE THESE VERY POOR
CONDITIONS ARE ALREADY SETTLING INTO KGRI AS OF THIS WRITING...IT
MAY TAKE ANOTHER 2-4 HOURS FOR THESE CONDITIONS TO DEVELOP
WESTWARD INTO KEAR. ALTHOUGH FOG ISSUES WILL LIKELY IMPROVE
THROUGH THE DAY...LOW STRATUS COULD REMAIN STUBBORNLY IN PLACE AT
KGRI WELL INTO THE AFTERNOON AT LEAST...WHILE KEAR MAY RESIDE
QUITE CLOSE TO THE INTERFACE BETWEEN THE LOW STRATUS AND LEGIT VFR
CONDITIONS FARTHER WEST/SOUTHWEST. AT LEAST FOR NOW...HAVE
HUNG ONTO A LOW-CONFIDENCE RETURN TO VFR CONDITIONS TO KGRI IN
THE MID-AFTERNOON AND A BIT EARLIER AT KEAR...BUT THIS IS SUBJECT
TO PLENTY OF CHANGE. THE BOTTOM LINE: IT MAY BE DIFFICULT ENOUGH
TRYING TO PIN DOWN THE FIRST 6 HOURS LET ALONE BEYOND THAT DURING
THESE NEXT 24 HOURS OR SO. FORTUNATELY...CONFIDENCE IN SURFACE
WIND IS CONSIDERABLY HIGHER...AS A LIGHT/VARIABLE REGIME THIS
MORNING GRADUALLY GIVES WAY TO STEADIER SOUTHEAST BREEZES DURING
THE DAY...WHICH THEN PICK UP EVEN MORE MONDAY EVENING WITH GUST
POTENTIAL 15-20KT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR NEZ039>041-
046>049-061>064-074>077-085>087.
KS...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR KSZ007-019.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...ROSSI
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
357 AM CST MON FEB 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM CST MON FEB 9 2015
THE ARCTIC FRONT AND FOG APPEAR TO BE STATIONARY AT 08Z. LOW
PRESSURE WILL DEEPEN ACROSS THE NRN HIGH PLAINS TODAY AND DRAW THE
FRONT WEST TOWARD HIGHWAY 83. THE HIGH TEMPERATURE FORECAST TODAY
USES THE RAP AND ARW MODELS WHICH HAVE DISPOSED OF ANY SNOW COVER
FOR HIGHS IN THE 60S WEST OF THE FRONT AND 40S EAST OF THE FRONT.
THE DENSE FOG THIS MORNING SHOULD LIFT FROM 15Z ONWARD AND
INCREASING WINDS ASSOCIATED WITH DEEPENING LOW PRESSURE SHOULD
PREVENT REDEVELOPMENT TONIGHT AS THIS LOW DROPS INTO SCNTL SD. LOWS
TONIGHT REFLECT THIS WITH 30S MOST AREAS...20S IN THE PLATTE RIVER
VALLEY CONFLUENCE.
GIVEN THE ABOVE FREEZING LOWS FORECAST TONIGHT...THE LIGHT RAIN
CHANCE NORTH OF ONEILL SHOULD NOT POSE AN ICE THREAT AND ALL MODEL
SOLNS SUGGEST THIS WILL BE THE CASE KEEPING THAT RISK WELL NORTH AND
EAST OF THE FCST AREA. STILL TEMPERATURES NORTH AND EAST OF ONEILL
ARE NEAR OR AT FREEZING SUGGESTING IT WILL BE CLOSE.
LASTLY...ALL MODELS MAINTAIN OVERCAST SKIES ALONG AND EAST OF THE
ARCTIC FRONT AND MOSTLY CLEAR SKIES WEST OF THE FRONT. A MULTI MODEL
BLEND WAS USED FOR SKY COVER TODAY AND TONIGHT WHICH LINED UP CLOSE
TO THE TEMPERATURE FORECAST PROVIDED BY THE ARW AND RAP MODELS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 356 AM CST MON FEB 9 2015
MAIN FORECAST CONCERNS THROUGH THE MID AND LONG RANGE PORTIONS OF
THE FORECAST DEAL WITH TEMPERATURES AS A PRIMARILY DRY FORECAST IS
AT HAND.
THE FORECAST MODELS ARE IN DECENT AGREEMENT THROUGHOUT THE TIME
PERIOD AS THE UPPER LEVEL PATTERN STAYS PERSISTENT WITH A LONGWAVE
TROUGH OVER THE EAST COAST AND RIDGING ACROSS THE WEST. THIS LEAVES
THE NORTHERN AND CENTRAL PLAINS UNDER THE INFLUENCE OF NORTHWEST
FLOW. THERE WILL BE SEVERAL WEAK SHORTWAVE TROUGHS THAT PASS OVER
THE LOCAL AREA...AND AS TIMING HAS IMPROVED WHEN COMPARING MODELS
HAVE HIGHER CONFIDENCE IN THEIR INFLUENCE THIS FORECAST CYCLE.
THE LARGE AND IMPRESSIVE LOOKING CYCLONE CURRENTLY OVER THE PACIFIC
NORTHWEST WILL WEAKEN OVER THE NEXT 24 HOURS AS IT MOVES FURTHER
ONSHORE AND CROSSES THE ROCKY MOUNTAINS. THIS WILL CAUSE IT TO BREAK
UP INTO SEVERAL WEAK PV ANOMALIES...WITH THE FIRST TWO PASSING
ACROSS THE NORTHERN AND CENTRAL PLAINS...WITH THE THIRD STAYING OVER
THE WESTERN CONUS...EVENTUALLY DIGGING INTO THE SOUTHWEST AND
CLOSING OFF OVER BAJA CALIFORNIA. WITH THE NORTHERN PV
ANOMALIES...THE FIRST WILL MOVE ACROSS THE CENTRAL PLAINS EARLY IN
THE DAY TUESDAY...WITH THE SECOND MOVING SOUTHEAST FROM NORTH DAKOTA
INTO IOWA TUESDAY NIGHT. THERE WILL BE ASSOCIATED SURFACE LOWS OVER
THE DAKOTAS WITH A WEAK FRONT DRAGGING ACROSS NEBRASKA THROUGH THE
DAY TUESDAY...THEN A SECOND STRONGER SURFACE COLD FRONT PASSING
ACROSS THE FORECAST AREA TUESDAY NIGHT. TEMPERATURES SHOULDN/T SEE
MUCH OF AN IMPACT FROM THE PASSAGE OF THE FIRST FRONT...HOWEVER DO
EXPECT WINDS BEHIND THE FRONT TO INCREASE A BIT AS THE BOUNDARY
LAYER MIXES. DID INCREASE HIGHS FOR TUESDAY SLIGHTLY AS THE TREND
LATELY HAS BEEN WARMER THAN THE MODELS HAVE BEEN INDICATING SO AT
LEAST PUT HIGHS NEAR THE HIGH END OF MODEL GUIDANCE. THE BETTER
CHANCES FOR WINDS TO INCREASE WILL COME BEHIND THE TUESDAY NIGHT
FRONT AS THE PRESSURE GRADIENT TIGHTENS...COLD AIR ADVECTION WILL BE
ONGOING...AND WITH UNIDIRECTIONAL WINDS GOING ALOFT AND 850MB WINDS
OF 30-40KTS IF THE BOUNDARY LAYER CAN STAY MIXED A BREEZY NIGHT WILL
BE IN STORE FOR MUCH OF THE AREA. DID LOWER LOWS TUESDAY NIGHT A FEW
DEGREES...BUT NOT SIGNIFICANTLY BECAUSE OF INCREASED CLOUD COVER AND
THE MIXED BOUNDARY LAYER...DESPITE THE COLDER AIR PUSHING IN.
WEDNESDAY SHOULD BE ANOTHER BREEZY DAY...ESPECIALLY EARLY ON. THE
PRESSURE GRADIENT WILL RELAX THROUGH THE DAY...BOTH AT THE SURFACE
AND ALOFT SO EVEN WITH GOOD MIXING OF THE BOUNDARY LAYER TO 850MB OR
800MB AS THE GFS WOULD SUGGEST WINDS WILL LIKELY DECREASE INTO THE
AFTERNOON HOURS. ALSO...TEMPERATURES WILL BE COOLER WITH NEAR NORMAL
VALUES EXPECTED. KEPT HIGHS SLIGHTLY ABOVE GUIDANCE VALUES DUE TO
TRENDS AND AS THERE SHOULD BE GOOD SUNSHINE TO HELP WARM THINGS
DURING THE DAY.
CANADIAN HIGH PRESSURE WILL BUILD INTO THE PLAINS WEDNESDAY NIGHT
AND THURSDAY BEHIND A POTENT SHORTWAVE TROUGH THAT WILL DIG
SOUTHEAST FROM THE NORTHWEST TERRITORIES INTO THE GREAT LAKES. THERE
ARE VERY SLIGHT DIFFERENCES IN THE DETAILS OF THIS SHORTWAVE...BUT
THESE DIFFERENCES WILL HAVE LITTLE IMPACT ON THE SENSIBLE WEATHER
LOCALLY. IN GENERAL...THIS SYSTEM WILL BRING A BACKDOOR COLD FRONT
ACROSS NEBRASKA WEDNESDAY NIGHT...BRINGING COOLER TEMPERATURES INTO
THE AREA. THAT BEING SAID...THE COLDEST AIR WITH 850MB TEMPERATURES
BELOW -20C WILL STAY WELL TO THE EAST OF THE AREA. LOWS WEDNESDAY
NIGHT WERE DROPPED A FEW DEGREES...WITH READINGS EXPECTED IN THE
SINGLE DIGITS AND TEENS FOR MUCH OF THE FORECAST AREA. ALSO...THE
SURFACE HIGH WILL DRIFT SOUTHEAST AND AT THIS TIME IS LOOKING TO
STAY EAST INTO THE MISSOURI AND MISSISSIPPI RIVER VALLEYS SO WILL
KEEP THE COLDEST OVERNIGHT TEMPERATURES EAST OF THE AREA.
THEN ANOTHER SHORTWAVE TROUGH WILL DIG INTO THE TROUGH ON SATURDAY.
THIS SYSTEM ORIGINATES OVER THE ARCTIC SO IT WILL HAVE COLDER AIR
YET WITH IT...BUT AS IT STAYS FAIRLY COMPACT...UNLESS THE MODELS
CHANGE TUNES AND ALLOW A TRACK FURTHER WEST...LOCAL AREAS WON/T
EXPERIENCE THE MUCH COLDER AIR. TEMPERATURES IN THE OUTER PERIODS OF
THE FORECAST WERE TRENDED COLDER FROM THE PREVIOUS
FORECAST...ESPECIALLY OVER THE EASTERN PARTS OF THE FORECAST
AREA...BECAUSE OF THE BETTER MODEL AGREEMENT WITH THESE STRONG
SYSTEMS MOVING SOUTH INTO THE TROUGH. THE WESTERN PORTIONS OF THE
FORECAST AREA MAY CONTINUE TO LIE JUST FAR ENOUGH WEST TO STAY UNDER
THE INFLUENCE OF THE RIDGE AND MAY CONTINUE TO SEE HIGHS ABOVE
NORMAL. AS MENTIONED EARLIER...THE FORECAST IS DRY THROUGH SUNDAY.
WITH EACH PASSING SHORTWAVE TROUGH...THERE WILL BE SOME ENHANCED
LIFT...BUT MOISTURE WILL BE VERY LIMITED...ESPECIALLY IN THE LOW
LEVELS AND THE SYSTEMS WILL BE MOVING QUICK ENOUGH TO DISALLOW
TOP-DOWN SATURATION FROM OCCURRING AND MAY JUST GET SOME VIRGA AT
TIMES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1149 PM CST SUN FEB 8 2015
BACK DOOR COLD FRONT BRINGING VLIFR CONDITIONS /STRATUS AND FOG/
TO PORTIONS OF NORTH CENTRAL NEBRASKA THROUGH MID MORNING. AT
THIS TIME NEAR TERM MODELS STALL THE FRONT NEAR AN KANW TO KBBW
LINE...THUS DO NOT HAVE A MENTION IN EITHER KLBF OR KVTN TERMINAL
FORECASTS. THIS WILL NEED TO BE MONITORED CLOSELY...OTHERWISE VFR
WITH SOME PASSING HIGH CLOUDS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR NEZ006-007-
009-010-028-029.
&&
$$
SHORT TERM...CDC
LONG TERM...BROOKS
AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
225 AM EST MON FEB 9 2015
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE EAST ALONG A FRONT DRAPED OVER THE
AREA BRINGING A MIX OF PRECIPITATION TO THE AREA TONIGHT. COLDER
AIR WILL MOVE INTO THE AREA OVERNIGHT AND MONDAY, CHANGING THE
WINTRY MIX TO ALL SNOW, FROM NORTH TO SOUTH. THE SNOW WILL
DIMINISH BY MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TODAY/...
930 PM UPDATE...
WEST TO EAST SURFACE BOUNDARY DIVIDING TEMPERATURES IN THE TEENS
TO THE NORTH AND 30S TO THE SOUTH. BEST PRECIP TO THE NORTH OF THE
BOUNDARY WHICH IS MOSTLY SNOW. THE BOUNDARY IS SLOWLY MOVING SOUTH
CHANGING MIXED PRECIP TO SNOW. IN NE PA MIXED BAG. TEMPS WILL COOL
AND PRECIP WILL CHANGE TO SNOW FROM N TO S. CHASING HOURLY TEMPS
WITH THE SHARP GRADIENT OTHERWISE GRIDS ARE DECENT. SNOW AMOUNTS
ACROSS THE FINGER LAKES AND MOHAWK VALLEY COMING IN HIGHER THAN
FORECAST BUT EITHER WAY SOLIDLY IN WARNING. SNOW AMOUNTS HERE
SOUTH STILL YET TO OCCUR SO CONFIDENCE LOWER. COMPARED TO
YESTERDAY MODELS PULL OUT SNOW FASTER MONDAY NIGHT SO TIMES MAY
NEED TO BE SHAVED ON THE BACK SIDE OF THE WARNING. SNOW ENDING
AFTERNOON AND EVE NOT EVE AND OVERNIGHT.
230 PM UPDATE...
AS COMPLEX AS THIS FORECAST IS, FROM A METEOROLOGICAL PERSPECTIVE
IT IS BEAUTIFUL TO WATCH. RIGHT NOW WE HAVE AN EXTREME THERMAL
GRADIENT ACROSS THE AREA. THE CENTRAL AND SOUTHERN PART OF THE
FORECAST AREA IS SITTING IN THE MIDDLE 30S TO NEAR 40, WHILE
SYRACUSE IS STILL JUST 19. YOU WANT TO TALK EXTREMES. ITHACA HAS
DROPPED TO 27 OVER THE PAST FEW HOURS WHILE JUST EAST AT CORTLAND
IT IS STILL 37! ALONG AND JUST NORTH OF THIS GRADIENT AN EAST/WEST
AXIS OF PRECIPITATION HAS BROKEN OUT FROM SOUTHERN ONTARIO EAST
THROUGH CENTRAL NEW YORK. GRADUALLY THROUGH EARLY EVENING THIS
AREA OF PRECIPITATION WILL EXPAND. AT FIRST THE THERMAL GRADIENT
WON`T MOVE MUCH, SO THE MAIN FOCUS OF PRECIPITATION WILL BE WHERE
IT IS NOW OR MAINLY ACROSS CENTRAL NEW YORK WITH LITTLE TO NO
PRECIPITATION FARTHER SOUTH.
LATER THIS EVENING AS THE BOUNDARY SLOWLY, SLOWLY SLIDES SOUTH,
OUR TEMPS WILL COOL AND THE EXPANDING AREA OF PRECIPITATION WILL
ALSO EXPAND SOUTHWARD. I THREW OUT THE MUCH WARMER 12Z GFS AS IT
IS ALREADY TOO WARM WITH 850 TEMPS OF +2C WHERE CURRENT MESO
ANALYSIS SHOWS 850 TEMPS CLOSER TO 0C OR -1C. IN FACT WHILE THE
12Z NAM AND 12Z EURO ARE THE CLOSEST MODELS TO REALITY AT 850 MB,
CURRENT ANALYSIS SHOWS THEY ARE EVEN RUNNING A TAD WARM AT THAT
LEVEL. FOLLOWING THE NAM AND RUC MODEL SOUNDINGS, AND LOOKING AT
THE LOW LEVEL DRY AIR WE HAVE IN PLACE, WET BULBING AS
PRECIPITATION EXPANDS THIS EVENING WILL LIKELY COOL THE COLUMN
ENOUGH TO CHANGE US OVER TO SNOW FROM NORTH TO SOUTH. DURING THE
TRANSITION A PERIOD OF SLEET OR FREEZING RAIN IS POSSIBLE.
ACROSS NY STATE, PRETTY MUCH ALL SNOW IS EXPECTED NORTH OF A
CORTLAND TO NORWICH LINE. ACROSS THE SOUTHERN TIER OF NY A WINTRY
MIX IS POSSIBLE AT THE ONSET, AND SURFACE TEMPS SUPPORT JUST RAIN
IN THE VALLEYS NEAR GREATER BINGHAMTON. EVEN HERE HOWEVER, COOLING
OF THE COLUMN WILL CHANGE US OVER TO ALL SNOW TOWARD 03Z/04Z AS
PRECIPITATION BECOMES STEADIER. A LIGHT COATING OF ICE IS POSSIBLE
PRIOR TO THE TRANSITION TO ALL SNOW, BUT ICE AMOUNTS ARE NOT
EXPECTED TO BE SIGNIFICANT IN NY STATE. TOTAL SNOW AMOUNTS WILL
RANGE FROM 8" TO 12" ACROSS CENTRAL NY AND THE CATSKILLS WHERE
WE STAY ALL SNOW. 5" TO 10" FROM THE FINGER LAKES DOWN THROUGH THE
SOUTHERN TIER WHERE MIXING IS A CONCERN. IN THE 5" TO 10" AREA,
THE HIGHER AMOUNTS WILL OCCUR IN THE FINGER LAKES, WITH THE LOWER
AMOUNTS NEAR THE NY/PA LINE.
ACROSS NORTHERN PA, THE TRANSITION PROCESS TO A WINTRY MIX AND
EVENTUALLY ALL SNOW WILL BE MUCH, MUCH SLOWER. THIS WILL BE
ESPECIALLY TRUE IN THE WILKES-BARRE/SCRANTON AREA. WHILE WE MAY
SEE A WINTRY MIX EARLY IN THE EVENING ACROSS THE NORTHERN TIER AND
NORMALLY COLDER SPOTS OF PIKE/WAYNE COUNTIES, THE WYOMING VALLEY
SHOULD NOT SEE ANY CHANGEOVER UNTIL AFTER MIDNIGHT. HERE WE DO NOT
EXPECT A CHANGE TO ALL SNOW UNTIL CLOSER TO MID MONDAY MORNING.
DUE TO THE PROLONGED PERIOD OF SLEET AND/OR FREEZING RAIN, ICE
AMOUNTS ARE EXPECTED TO BE MORE SIGNIFICANT, AND SNOW AMOUNTS LESS
SO. ICE AMOUNTS BETWEEN A TENTH AND TWO TENTHS ARE LIKELY, WITH
SNOW GENERALLY IN THE 3" TO 6" RANGE. THE HIGHEST SNOW AMOUNTS
WILL BE NEAR THE NY/PA LINE. CURRENT ADVISORY AND WARNING IN GOOD
SHAPE WITH MINOR SNOW ADJUSTMENTS TO REFLECT LATEST TRENDS OF
SLIGHTLY LESS SNOW FROM NEAR THE NY/PA LINE SOUTHWARD.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
245 PM UPDATE...
MONDAY NIGHT/TUESDAY...DRYING IN THE -10C TO -20C LAYER MONDAY
NIGHT WILL MEAN AN END TO PRECIPITATION FROM WEST TO EAST. SINCE
WE STILL HAVE A BIT OF MOISTURE BUT NOT MUCH IN THE IDEAL SNOW
GROWTH REGION, IN INCLUDED A MENTION OF FREEZING DRIZZLE/FLURRIES
WHERE CHANCES FOR PRECIPITATION DROP BELOW 60%. DRIER WEATHER
BUILDS IN FOR TUESDAY.
TUESDAY NIGHT...SFC HIGH PRES OVER EASTERN CANADA WILL PROVIDE A
MAINLY CLEAR AND COLD NIGHT. LOWS WILL GENERALLY RANGE IN THE
SINGLE NUMBERS WITH READINGS AROUND 10 ACROSS THE FAR SE.
WEDNESDAY...A CLIPPER LOW WILL MOVE THROUGH THE NORTHERN GREAT
LAKES AND BRING A CHANCE FOR LIGHT SNOW DURING THE AFTERNOON
ACROSS MUCH OF CENTRAL NEW YORK. WILL CONTINUE WITH A DRY FORECAST
FOR NE PA AS BEST MOISTURE AND LIFT WILL RESIDE OVER THE NRN CWA.
BRIEF WARMUP AHEAD OF THIS SYSTEM WILL ALLOW TEMPS TO RISE INTO
THE MID/UPPER 20S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
0225 AM UPDATE...NO MAJOR CHANGES NEEDED TO LONG RANGE FORECAST
WITH THIS UPDATE. GUIDANCE IS STILL IN GOOD AGREEMENT ON A VERY
COLD PATTERN FOR LATE THIS WEEK THROUGH NEXT WEEKEND. ONLY MINOR
ADJUSTMENTS TO POP/WX GRIDS WERE MADE FOR THURSDAY AND FRIDAY AS
POPS WERE ADJUSTED UP DOWNWIND OF LAKE ONTARIO WHERE THERE WILL
LIKELY BE SOME LAKE EFFECT
PREVIOUS DISCUSSION...EXTENDED FORECAST PERIOD WILL BE DOMINATED BY AN UPPER
LEVEL TROF OVER THE EASTERN UNITED STATES WHICH WILL KEEP
TEMPERATURES WELL BELOW NORMAL THROUGH THE PERIOD.
WEDNESDAY NIGHT INTO THURSDAY A CLIPPER SFC LOW WILL TRACK THROUGH
THE SOUTHERN GREAT LAKES THEN EASTWARD THROUGH PA. THIS FEATURE
WILL BRING LIGHT SNOW ACCUMS TO THE REGION, GENERALLY LESS THAN
THREE INCHES. ONCE THIS WAVE PASSES ANOTHER SHOT OF ARCTIC AIR
WILL OVERSPREAD THE REGION AND PERSIST THROUGH THE WEEKEND. TEMPS
THURSDAY NIGHT THROUGH SATURDAY WILL RUN 15 TO 25 DEGREES BELOW
NORMAL. ANOTHER WEAK CLIPPER TYPE LOW MAY IMPACT THE AREA SATURDAY
INTO SATURDAY NIGHT.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
06Z UPDATE...
SNOW WILL CONTINUE OVERNIGHT THROUGH MONDAY MORNING FOR THE NY
TERMINALS WITH CONDITIONS PREDOMINATELY BELOW ALTERNATE MINIMUMS
AS VISIBILITIES WILL GENERALLY BE AROUND 1 SM. FOR KAVP, RAIN WILL
CHANGE TO A MIX OF FREEZING RAIN AND SLEET LATE TONIGHT WITH
VISIBILITIES LOWERING TO IFR AND THEN BELOW ALTERNATE MINS BY MID
MORNING MONDAY AS PRECIPITATION CHANGES TO ALL SNOW. SNOW WILL
GRADUALLY EASE THROUGH MONDAY AFTERNOON INTO THE EARLY EVENING
WITH IMPROVING CONDITIONS DURING THIS TIME PERIOD FOR ALL TERMINALS.
HOWEVER WE STILL EXPECT MVFR CONDITIONS THROUGH MONDAY EVENING.
ALSO, THERE WILL BE A RISK FOR SOME PATCHY FREEZING DRIZZLE MONDAY
EVENING BUT AT THIS POINT CONFIDENCE IS NOT HIGH ENOUGH TO MENTION
IT IN THE TAFS. WINDS GENERALLY VARIABLE BUT UNDER 10 KTS.
OUTLOOK...
MON NGT - TUE...MVFR CIG POSSIBLY LASTING MUCH OF TUE FOR SEVERAL
TERMINALS DUE TO MOISTURE TRAPPED UNDER INVERSION.
TUE NGT - WED MRNG...MAINLY VFR.
LATE WED - THU...RESTRICTIONS POSSIBLE AREA-WIDE FROM AREAWIDE -SN.
FRI...RESTRICTIONS POSSIBLE AT THE CNY TERMINALS FROM
-SHSN...WITH MAINLY VFR EXPECTED AT KAVP.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 1 AM EST TUESDAY FOR PAZ038>040-
043-044-047-048-072.
NY...WINTER STORM WARNING UNTIL 7 AM EST TUESDAY FOR NYZ009-015>018-
022>025-036-037-044>046-055>057-062.
&&
$$
SYNOPSIS...HEDEN/TAC
NEAR TERM...HEDEN/TAC
SHORT TERM...HEDEN/RRM
LONG TERM...PCF/RRM
AVIATION...PCF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1254 AM EST MON FEB 9 2015
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE EAST ALONG A FRONT DRAPED OVER THE
AREA BRINGING A MIX OF PRECIPITATION TO THE AREA TONIGHT. COLDER
AIR WILL MOVE INTO THE AREA OVERNIGHT AND MONDAY, CHANGING THE
WINTRY MIX TO ALL SNOW, FROM NORTH TO SOUTH. THE SNOW WILL
DIMINISH BY MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TODAY/...
930 PM UPDATE...
WEST TO EAST SURFACE BOUNDARY DIVIDING TEMPERATURES IN THE TEENS
TO THE NORTH AND 30S TO THE SOUTH. BEST PRECIP TO THE NORTH OF THE
BOUNDARY WHICH IS MOSTLY SNOW. THE BOUNDARY IS SLOWLY MOVING SOUTH
CHANGING MIXED PRECIP TO SNOW. IN NE PA MIXED BAG. TEMPS WILL COOL
AND PRECIP WILL CHANGE TO SNOW FROM N TO S. CHASING HOURLY TEMPS
WITH THE SHARP GRADIENT OTHERWISE GRIDS ARE DECENT. SNOW AMOUNTS
ACROSS THE FINGER LAKES AND MOHAWK VALLEY COMING IN HIGHER THAN
FORECAST BUT EITHER WAY SOLIDLY IN WARNING. SNOW AMOUNTS HERE
SOUTH STILL YET TO OCCUR SO CONFIDENCE LOWER. COMPARED TO
YESTERDAY MODELS PULL OUT SNOW FASTER MONDAY NIGHT SO TIMES MAY
NEED TO BE SHAVED ON THE BACK SIDE OF THE WARNING. SNOW ENDING
AFTERNOON AND EVE NOT EVE AND OVERNIGHT.
230 PM UPDATE...
AS COMPLEX AS THIS FORECAST IS, FROM A METEOROLOGICAL PERSPECTIVE
IT IS BEAUTIFUL TO WATCH. RIGHT NOW WE HAVE AN EXTREME THERMAL
GRADIENT ACROSS THE AREA. THE CENTRAL AND SOUTHERN PART OF THE
FORECAST AREA IS SITTING IN THE MIDDLE 30S TO NEAR 40, WHILE
SYRACUSE IS STILL JUST 19. YOU WANT TO TALK EXTREMES. ITHACA HAS
DROPPED TO 27 OVER THE PAST FEW HOURS WHILE JUST EAST AT CORTLAND
IT IS STILL 37! ALONG AND JUST NORTH OF THIS GRADIENT AN EAST/WEST
AXIS OF PRECIPITATION HAS BROKEN OUT FROM SOUTHERN ONTARIO EAST
THROUGH CENTRAL NEW YORK. GRADUALLY THROUGH EARLY EVENING THIS
AREA OF PRECIPITATION WILL EXPAND. AT FIRST THE THERMAL GRADIENT
WON`T MOVE MUCH, SO THE MAIN FOCUS OF PRECIPITATION WILL BE WHERE
IT IS NOW OR MAINLY ACROSS CENTRAL NEW YORK WITH LITTLE TO NO
PRECIPITATION FARTHER SOUTH.
LATER THIS EVENING AS THE BOUNDARY SLOWLY, SLOWLY SLIDES SOUTH,
OUR TEMPS WILL COOL AND THE EXPANDING AREA OF PRECIPITATION WILL
ALSO EXPAND SOUTHWARD. I THREW OUT THE MUCH WARMER 12Z GFS AS IT
IS ALREADY TOO WARM WITH 850 TEMPS OF +2C WHERE CURRENT MESO
ANALYSIS SHOWS 850 TEMPS CLOSER TO 0C OR -1C. IN FACT WHILE THE
12Z NAM AND 12Z EURO ARE THE CLOSEST MODELS TO REALITY AT 850 MB,
CURRENT ANALYSIS SHOWS THEY ARE EVEN RUNNING A TAD WARM AT THAT
LEVEL. FOLLOWING THE NAM AND RUC MODEL SOUNDINGS, AND LOOKING AT
THE LOW LEVEL DRY AIR WE HAVE IN PLACE, WET BULBING AS
PRECIPITATION EXPANDS THIS EVENING WILL LIKELY COOL THE COLUMN
ENOUGH TO CHANGE US OVER TO SNOW FROM NORTH TO SOUTH. DURING THE
TRANSITION A PERIOD OF SLEET OR FREEZING RAIN IS POSSIBLE.
ACROSS NY STATE, PRETTY MUCH ALL SNOW IS EXPECTED NORTH OF A
CORTLAND TO NORWICH LINE. ACROSS THE SOUTHERN TIER OF NY A WINTRY
MIX IS POSSIBLE AT THE ONSET, AND SURFACE TEMPS SUPPORT JUST RAIN
IN THE VALLEYS NEAR GREATER BINGHAMTON. EVEN HERE HOWEVER, COOLING
OF THE COLUMN WILL CHANGE US OVER TO ALL SNOW TOWARD 03Z/04Z AS
PRECIPITATION BECOMES STEADIER. A LIGHT COATING OF ICE IS POSSIBLE
PRIOR TO THE TRANSITION TO ALL SNOW, BUT ICE AMOUNTS ARE NOT
EXPECTED TO BE SIGNIFICANT IN NY STATE. TOTAL SNOW AMOUNTS WILL
RANGE FROM 8" TO 12" ACROSS CENTRAL NY AND THE CATSKILLS WHERE
WE STAY ALL SNOW. 5" TO 10" FROM THE FINGER LAKES DOWN THROUGH THE
SOUTHERN TIER WHERE MIXING IS A CONCERN. IN THE 5" TO 10" AREA,
THE HIGHER AMOUNTS WILL OCCUR IN THE FINGER LAKES, WITH THE LOWER
AMOUNTS NEAR THE NY/PA LINE.
ACROSS NORTHERN PA, THE TRANSITION PROCESS TO A WINTRY MIX AND
EVENTUALLY ALL SNOW WILL BE MUCH, MUCH SLOWER. THIS WILL BE
ESPECIALLY TRUE IN THE WILKES-BARRE/SCRANTON AREA. WHILE WE MAY
SEE A WINTRY MIX EARLY IN THE EVENING ACROSS THE NORTHERN TIER AND
NORMALLY COLDER SPOTS OF PIKE/WAYNE COUNTIES, THE WYOMING VALLEY
SHOULD NOT SEE ANY CHANGEOVER UNTIL AFTER MIDNIGHT. HERE WE DO NOT
EXPECT A CHANGE TO ALL SNOW UNTIL CLOSER TO MID MONDAY MORNING.
DUE TO THE PROLONGED PERIOD OF SLEET AND/OR FREEZING RAIN, ICE
AMOUNTS ARE EXPECTED TO BE MORE SIGNIFICANT, AND SNOW AMOUNTS LESS
SO. ICE AMOUNTS BETWEEN A TENTH AND TWO TENTHS ARE LIKELY, WITH
SNOW GENERALLY IN THE 3" TO 6" RANGE. THE HIGHEST SNOW AMOUNTS
WILL BE NEAR THE NY/PA LINE. CURRENT ADVISORY AND WARNING IN GOOD
SHAPE WITH MINOR SNOW ADJUSTMENTS TO REFLECT LATEST TRENDS OF
SLIGHTLY LESS SNOW FROM NEAR THE NY/PA LINE SOUTHWARD.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
245 PM UPDATE...
MONDAY NIGHT/TUESDAY...DRYING IN THE -10C TO -20C LAYER MONDAY
NIGHT WILL MEAN AN END TO PRECIPITATION FROM WEST TO EAST. SINCE
WE STILL HAVE A BIT OF MOISTURE BUT NOT MUCH IN THE IDEAL SNOW
GROWTH REGION, IN INCLUDED A MENTION OF FREEZING DRIZZLE/FLURRIES
WHERE CHANCES FOR PRECIPITATION DROP BELOW 60%. DRIER WEATHER
BUILDS IN FOR TUESDAY.
TUESDAY NIGHT...SFC HIGH PRES OVER EASTERN CANADA WILL PROVIDE A
MAINLY CLEAR AND COLD NIGHT. LOWS WILL GENERALLY RANGE IN THE
SINGLE NUMBERS WITH READINGS AROUND 10 ACROSS THE FAR SE.
WEDNESDAY...A CLIPPER LOW WILL MOVE THROUGH THE NORTHERN GREAT
LAKES AND BRING A CHANCE FOR LIGHT SNOW DURING THE AFTERNOON
ACROSS MUCH OF CENTRAL NEW YORK. WILL CONTINUE WITH A DRY FORECAST
FOR NE PA AS BEST MOISTURE AND LIFT WILL RESIDE OVER THE NRN CWA.
BRIEF WARMUP AHEAD OF THIS SYSTEM WILL ALLOW TEMPS TO RISE INTO
THE MID/UPPER 20S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
EXTENDED FORECAST PERIOD WILL BE DOMINATED BY AN UPPER LEVEL TROF
OVER THE EASTERN UNITED STATES WHICH WILL KEEP TEMPERATURES WELL
BELOW NORMAL THROUGH THE PERIOD.
WEDNESDAY NIGHT INTO THURSDAY A CLIPPER SFC LOW WILL TRACK THROUGH
THE SOUTHERN GREAT LAKES THEN EASTWARD THROUGH PA. THIS FEATURE
WILL BRING LIGHT SNOW ACCUMS TO THE REGION, GENERALLY LESS THAN
THREE INCHES. ONCE THIS WAVE PASSES ANOTHER SHOT OF ARCTIC AIR
WILL OVERSPREAD THE REGION AND PERSIST THROUGH THE WEEKEND. TEMPS
THURSDAY NIGHT THROUGH SATURDAY WILL RUN 15 TO 25 DEGREES BELOW
NORMAL. ANOTHER WEAK CLIPPER TYPE LOW MAY IMPACT THE AREA SATURDAY
INTO SATURDAY NIGHT.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
06Z UPDATE...
SNOW WILL CONTINUE OVERNIGHT THROUGH MONDAY MORNING FOR THE NY
TERMINALS WITH CONDITIONS PREDOMINATELY BELOW ALTERNATE MINIMUMS
AS VISIBILITIES WILL GENERALLY BE AROUND 1 SM. FOR KAVP, RAIN WILL
CHANGE TO A MIX OF FREEZING RAIN AND SLEET LATE TONIGHT WITH
VISIBILITIES LOWERING TO IFR AND THEN BELOW ALTERNATE MINS BY MID
MORNING MONDAY AS PRECIPITATION CHANGES TO ALL SNOW. SNOW WILL
GRADUALLY EASE THROUGH MONDAY AFTERNOON INTO THE EARLY EVENING
WITH IMPROVING CONDITIONS DURING THIS TIME PERIOD FOR ALL TERMINALS.
HOWEVER WE STIL EXPECT MVFR CONDITIONS THROUGH MONDAY EVENING.
ALSO, THERE WILL BE A RISK FOR SOME PATCHY FREEZING DRIZZLE MONDAY
EVENING BUT AT THIS POINT CONFIDENCE IS NOT HIGH ENOUGH TO MENTION
IT IN THE TAFS. WINDS GENERALLY VARIABLE BUT UNDER 10 KTS.
OUTLOOK...
MON NGT - TUE...MVFR CIG POSSIBLY LASTING MUCH OF TUE FOR SEVERAL
TERMINALS DUE TO MOISTURE TRAPPED UNDER INVERSION.
TUE NGT - WED MRNG...MAINLY VFR.
LATE WED - THU...RESTRICTIONS POSSIBLE AREA-WIDE FROM AREAWIDE -SN.
FRI...RESTRICTIONS POSSIBLE AT THE CNY TERMINALS FROM
-SHSN...WITH MAINLY VFR EXPECTED AT KAVP.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 1 AM EST TUESDAY FOR PAZ038>040-
043-044-047-048-072.
NY...WINTER STORM WARNING UNTIL 7 AM EST TUESDAY FOR NYZ009-015>018-
022>025-036-037-044>046-055>057-062.
&&
$$
SYNOPSIS...HEDEN/TAC
NEAR TERM...HEDEN/TAC
SHORT TERM...HEDEN/RRM
LONG TERM...RRM
AVIATION...PCF
AREA FORECAST DISCUSSION
NWS BISMARCK ND
859 PM CST TUE FEB 10 2015
.UPDATE...
ISSUED AT 856 PM CST TUE FEB 10 2015
ALTHOUGH SOME ISOLATED GUSTS IN SIOUX AND BURLEIGH COUNTY
REMAIN...THE WINDS ARE GENERALLY DIMINISHING SOUTH CENTRAL SO
WILL ALLOW THE WIND ADVISORY TO EXPIRE THERE. ACROSS THE JAMES RIVER
VALLEY OAKS IS GUSTING TO 48 MPH AT THIS TIME. WILL KEEP THE JAMES
RIVER VALLEY PORTION GONG THROUGH EXPIRATION AT 06Z/MIDNIGHT CST.
UPDATE ISSUED AT 551 PM CST TUE FEB 10 2015
LATEST WINDS AND WIND GUSTS NOW INCREASING ACROSS THE SOUTH
CENTRAL AS THE FORECAST 3HR PRESSURE RISE MOVES ACROSS THIS AREA.
CURRENT WIND ADVISORY IN PLACE FOR A LOW END ADVISORY. SATELLITE
AND RADAR SHOW SOME BANDED SNOW SHOWERS THROUGH CENTRAL NORTH
DAKOTA/ WILL AD 30 TO 50 CHANCE FOR SNOW MINOT TO BISMARCK TO
JAMESTOWN FOR THIS THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 320 PM CST TUE FEB 10 2015
STRONG WINDS AND FALLING TEMPERATURES HIGHLIGHT THE SHORT TERM FORECAST.
AS A OF 20 UTC...A 5MB/3HR PRESSURE RISE BUBBLE WAS ANALYZED OVER
LAKE SAKAKAWEA. THIS FEATURE WILL CONTINUE TO PROPAGATE SOUTHEAST
THROUGH THE LATE AFTERNOON AND EARLY EVENING. WITH 35 TO 40 KTS TO
MIX PER 19 UTC RAP SOUNDINGS...AND ISALLOBARIC FORCING FROM THE
PRESSURE RISES...LOW END WIND ADVISORY CRITERIA GUSTS ARE EXPECTED
INTO THE EARLY EVENING SOUTHWEST AND SOUTH CENTRAL. DID MAINTAIN
A SLIGHT CHANCE FOR SNOW THROUGH THE EVENING AS WELL FOR MUCH OF
WESTERN AND CENTRAL NORTH DAKOTA WITH LIGHT SNOW BEING OBSERVED AT
MULTIPLE SITES ACROSS NORTH DAKOTA INTO SOUTHERN CANADA.
FOR WEDNESDAY...COLD SURFACE HIGH PRESSURE WILL BUILD ACROSS NORTH
DAKOTA. THIS WILL YIELD LITTLE TEMPERATURE RECOVERY FROM MORNING
LOWS WITH CONTINUED COLD AIR ADVECTION THROUGH THE DAY. ADVISORY
LEVEL WIND CHILLS MAY BE POSSIBLE ACROSS THE TURTLE MOUNTAINS BY
LATE AFTERNOON. HOWEVER...WILL FORGO ANY ADVISORY FOR NOW. GIVEN
GOOD AGREEMENT THROUGH THE PERIOD...A BLEND OF THE 12 UTC SUITE
WAS USED FOR MOST FIELDS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 320 PM CST TUE FEB 10 2015
THE LONG TERM WILL BE CHARACTERIZED BY SEVERAL COLD BLASTS AND
OCCASIONAL SNOW CHANCES.
WEDNESDAY NIGHT INTO THURSDAY IS WHEN THE FIRST SUCH COLD BLAST
ENTERS THE REGION. ARCTIC HIGH PRESSURE WILL SETTLE OVER NORTH
DAKOTA THURSDAY MORNING. WITH CLEAR SKIES AND THE MAJORITY OF THE
REGION UNDER AT LEAST A LIGHT BLANKET OF SNOW...TEMPERATURES
SHOULD PLUMMET THURSDAY MORNING INTO THE TEENS AND POSSIBLY 20S
BELOW ZERO EAST OF THE MISSOURI RIVER. SCATTERED LIGHT SNOW MAY
FOLLOW THE HIGH PRESSURE AS AN UPPER LEVEL JET SHOULD BE IN A
FAVORABLE POSITION FOR BROAD SCALE LIFT.
THE NEXT BLAST ARRIVES SATURDAY...WHERE ONCE AGAIN TEMPERATURES
SHOULD ONCE AGAIN FALL INTO THE TEENS BELOW ZERO. AND ONCE AGAIN
SNOW WILL BE POSSIBLE FOLLOWING THE HIGH PRESSURE. HOWEVER...THE
12 UTC GFS AND ECMWF ARE MORE BULLISH WITH THIS EVENT AS A SURFACE
LOW IS FORECAST TO DEVELOP ACROSS EASTERN MONTANA AND SLIDE
SOUTHEAST THROUGH THE DAY SUNDAY. THERE IS THE POTENTIAL FOR MORE
SIGNIFICANT ACCUMULATION WITH THIS EVENT AS THERE APPEARS TO BE
FOCUSED LOW LEVEL ASCENT ALONG WITH THE UPPER LEVEL JET DYNAMICS.
OTHERWISE...THE LONG TERM LOOKS DRY...WITH COLD TEMPERATURES EAST
OF THE MISSOURI AND TEMPERATURES WEST OF THE MISSOURI RIVER
LOOKING RATHER MILD...WITH READINGS IN THE 30S MOST DAYS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 551 PM CST TUE FEB 10 2015
MAIN HAZARDS TO AVIATION WILL BE MVR TO LOCAL IFR CEILINGS AND
VSBYS IN SNOW SHOWERS THIS EVENING. SNOW WILL GREATLY DIMINISH
AFTER 03Z. THEN CLOUDS MVFR TO LOW VFR STRATUS WILL REMAIN OVER
MOST OF THE REGION,
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR NDZ023-025-036-037-
047-048-050-051.
&&
$$
UPDATE...WAA
SHORT TERM...AYD
LONG TERM...AJ
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
601 PM CST TUE FEB 10 2015
.UPDATE...
ISSUED AT 551 PM CST TUE FEB 10 2015
LATEST WINDS AND WIND GUSTS NOW INCREASING ACROSS THE SOUTH
CENTRAL AS THE FORECAST 3HR PRESSURE RISE MOVES ACROSS THIS AREA.
CURRENT WIND ADVISORY IN PLACE FOR A LOW END ADVISORY. SATELLITE
AND RADAR SHOW SOME BANDED SNOW SHOWERS THROUGH CENTRAL NORTH
DAKOTA/ WILL AD 30 TO 50 CHANCE FOR SNOW MINOT TO BISMARCK TO
JAMESTOWN FOR THIS THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 320 PM CST TUE FEB 10 2015
STRONG WINDS AND FALLING TEMPERATURES HIGHLIGHT THE SHORT TERM FORECAST.
AS A OF 20 UTC...A 5MB/3HR PRESSURE RISE BUBBLE WAS ANALYZED OVER
LAKE SAKAKAWEA. THIS FEATURE WILL CONTINUE TO PROPAGATE SOUTHEAST
THROUGH THE LATE AFTERNOON AND EARLY EVENING. WITH 35 TO 40 KTS TO
MIX PER 19 UTC RAP SOUNDINGS...AND ISALLOBARIC FORCING FROM THE
PRESSURE RISES...LOW END WIND ADVISORY CRITERIA GUSTS ARE EXPECTED
INTO THE EARLY EVENING SOUTHWEST AND SOUTH CENTRAL. DID MAINTAIN
A SLIGHT CHANCE FOR SNOW THROUGH THE EVENING AS WELL FOR MUCH OF
WESTERN AND CENTRAL NORTH DAKOTA WITH LIGHT SNOW BEING OBSERVED AT
MULTIPLE SITES ACROSS NORTH DAKOTA INTO SOUTHERN CANADA.
FOR WEDNESDAY...COLD SURFACE HIGH PRESSURE WILL BUILD ACROSS NORTH
DAKOTA. THIS WILL YIELD LITTLE TEMPERATURE RECOVERY FROM MORNING
LOWS WITH CONTINUED COLD AIR ADVECTION THROUGH THE DAY. ADVISORY
LEVEL WIND CHILLS MAY BE POSSIBLE ACROSS THE TURTLE MOUNTAINS BY
LATE AFTERNOON. HOWEVER...WILL FORGO ANY ADVISORY FOR NOW. GIVEN
GOOD AGREEMENT THROUGH THE PERIOD...A BLEND OF THE 12 UTC SUITE
WAS USED FOR MOST FIELDS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 320 PM CST TUE FEB 10 2015
THE LONG TERM WILL BE CHARACTERIZED BY SEVERAL COLD BLASTS AND
OCCASIONAL SNOW CHANCES.
WEDNESDAY NIGHT INTO THURSDAY IS WHEN THE FIRST SUCH COLD BLAST
ENTERS THE REGION. ARCTIC HIGH PRESSURE WILL SETTLE OVER NORTH
DAKOTA THURSDAY MORNING. WITH CLEAR SKIES AND THE MAJORITY OF THE
REGION UNDER AT LEAST A LIGHT BLANKET OF SNOW...TEMPERATURES
SHOULD PLUMMET THURSDAY MORNING INTO THE TEENS AND POSSIBLY 20S
BELOW ZERO EAST OF THE MISSOURI RIVER. SCATTERED LIGHT SNOW MAY
FOLLOW THE HIGH PRESSURE AS AN UPPER LEVEL JET SHOULD BE IN A
FAVORABLE POSITION FOR BROAD SCALE LIFT.
THE NEXT BLAST ARRIVES SATURDAY...WHERE ONCE AGAIN TEMPERATURES
SHOULD ONCE AGAIN FALL INTO THE TEENS BELOW ZERO. AND ONCE AGAIN
SNOW WILL BE POSSIBLE FOLLOWING THE HIGH PRESSURE. HOWEVER...THE
12 UTC GFS AND ECMWF ARE MORE BULLISH WITH THIS EVENT AS A SURFACE
LOW IS FORECAST TO DEVELOP ACROSS EASTERN MONTANA AND SLIDE
SOUTHEAST THROUGH THE DAY SUNDAY. THERE IS THE POTENTIAL FOR MORE
SIGNIFICANT ACCUMULATION WITH THIS EVENT AS THERE APPEARS TO BE
FOCUSED LOW LEVEL ASCENT ALONG WITH THE UPPER LEVEL JET DYNAMICS.
OTHERWISE...THE LONG TERM LOOKS DRY...WITH COLD TEMPERATURES EAST
OF THE MISSOURI AND TEMPERATURES WEST OF THE MISSOURI RIVER
LOOKING RATHER MILD...WITH READINGS IN THE 30S MOST DAYS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 551 PM CST TUE FEB 10 2015
MAIN HAZARDS TO AVIATION WILL BE MVR TO LOCAL IFR CEILINGS AND
VSBYS IN SNOW SHOWERS THIS EVENING. SNOW WILL GREATLY DIMINISH
AFTER 03Z. THEN CLOUDS MVFR TO LOW VFR STRATUS WILL REMAIN OVER
MOST OF THE REGION,
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 9 PM CST /8 PM MST/ THIS EVENING FOR
NDZ019>022-033>035-040>046.
WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR NDZ023-025-036-037-
047-048-050-051.
&&
$$
UPDATE...WAA
SHORT TERM...AYD
LONG TERM...AJ
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
410 PM CST MON FEB 9 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 400 PM CST MON FEB 9 2015
THE UPCOMING MIXED PRECIPITATION EVENT HIGHLIGHTS THE SHORT TERM
FORECAST.
IN REGARDS TO HEADLINES...WILL LET THE DENSE FOG ADVISORY ACROSS
MUCH OF THE WEST AND CENTRAL CONTINUE THROUGH 00 UTC WITH
CONTINUED UPSLOPE SOUTHEASTERLY FLOW. OTHER THAN ADDING
SIOUX...GRANT...STARK AND HETTINGER COUNTIES TO THE FREEZING RAIN
ADVISORY...ALL OTHER WINTER HEADLINES REMAIN UNCHANGED.
IN GENERAL...OVERALL EXPECTATIONS FOR THE EVENT VARY LITTLE WITH
THIS FORECAST PACKAGE THAT UTILIZED THE 12 AND INCOMING 18 UTC
DETERMINISTIC AND ENSEMBLE SUITES COMPARED TO THE 06 AND 00 UTC
GUIDANCE. THE 18 THROUGH 20 UTC HRRR ITERATIONS LINE UP WELL WITH
RADAR ACROSS EASTERN MONTANA AND WILL WEIGH HEAVILY ON THESE
SOLUTIONS IN THE NEAR TERM...BLENDED TO THE GLOBAL 12 AND 18 UTC
SUITES THROUGH THE NIGHT. THIS SUPPORTS AN EXPANDED THREAT FOR
FREEZING RAIN INTO SOUTHWEST NORTH DAKOTA GIVEN SURFACE
TEMPERATURES THAT HAVE REMAINED BELOW FREEZING UNDER THE STRATUS.
FOLLOWED CLOSELY TO THE 19-20 UTC RAP AND 18 UTC NAM BUFR
SOUNDINGS FOR THE STRENGTH OF THE WARM LAYER ALOFT. AS ALWAYS IN
MIXED PRECIPITATION TYPES EVENTS...THIS VARIABLE IS THE MOST
UNCERTAIN. EXPECT THE WARM LAYER ALOFT TO SUPPORT LIQUID TO THE
SURFACE FROM NORTHWEST THROUGH SOUTH CENTRAL NORTH DAKOTA THROUGH
10-12 UTC...BEFORE A TRANSITION TO A SLEET AND SNOW MIX AND AN
EVENTUAL END TO PRECIPITATION WITH A DRY SLOT OVERTAKING THE AREA.
FOR LOCATIONS ALONG AND NORTH OF HIGHWAYS 2 AND
52....PRECIPITATION IS EXPECTED TO BE ALL SNOW...WITH A SLIGHT
CHANCE FOR FREEZING DRIZZLE GIVEN LOW LEVEL SATURATION WARMER
THAN -10 C UNTIL THE FULL COLUMN CAN SATURATE AND SUPPORT ICE
CRYSTALS TO THE GROUND. THE 18 UTC GFS/NAM HAVE BOTH COME IN WITH
HIGHER QPF...ESPECIALLY ACROSS THE JAMES RIVER VALLEY INTO THE
TURTLE MOUNTAINS IN THE 06-12 UTC TIME FRAME. THIS TREND WILL HAVE
TO BE MONITORED IN THE 00 UTC RUNS...AS THIS WOULD LEAD TO HIGHER
SNOWFALL...AND POSSIBLE GREATER ICE ACCUMULATIONS IN THE SOUTHERN
JAMES RIVER VALLEY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 410 PM CST MON FEB 9 2015
...THE MAIN IMPACT IN THE LONG TERM IS COLD...
TUESDAY`S SYSTEM WILL DEPART THE REGION BY LATE TUESDAY NIGHT.
SCATTERED LIGHT SNOW WILL DIMINISH THROUGH THE EVENING HOURS WITH
LITTLE TO NO ADDITIONAL ACCUMULATION EXPECTED.
THE REST OF THE LONG TERM FORECAST LOOKS RATHER COLD ACROSS THE
EAST AND MILD ACROSS THE SOUTHWEST. A COLD AND DRY ARCTIC AIRMASS
WILL ENTER WEDNESDAY INTO THURSDAY. A STRONG SURFACE HIGH WILL
SETTLE ACROSS THE AREA THURSDAY MORNING...WHICH COULD LEAD TO VERY
COLD TEMPERATURES...AROUND 20 BELOW...ACROSS NORTH CENTRAL NORTH
DAKOTA.
A WARM FRONT IS THEN EXPECTED TO ENTER WESTERN NORTH DAKOTA
THURSDAY AFTERNOON AND EVENING WHICH SHOULD BRING MUCH WARMER
TEMPERATURES WESTERN NORTH DAKOTA. OVERALL THE LONG TERM LOOKS
RATHER DRY...WITH A FEW FLURRIES POSSIBLE THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY EVENING)
ISSUED AT 400 PM CST MON FEB 9 2015
WIDESPREAD IFR TO LIFR CONDITIONS IN FOG AND STRATUS WILL CONTINUE
THIS AFTERNOON AND INTO THE EVENING ACROSS WESTERN AND CENTRAL
NORTH DAKOTA. ANOTHER ROUND OF LIGHT FREEZING RAIN WILL
OVERSPREAD KISN/KDIK/KBIS BETWEEN 00Z AND 06Z TUESDAY...WITH LIGHT
SNOW DEVELOPING OVER KMOT AND LIGHT SNOW AND SLEET AT KJMS MONDAY
NIGHT. CONTINUED IFR CONDITIONS EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR
NDZ009-010-017>020-031>034-040>045.
FREEZING RAIN ADVISORY FROM 9 PM CST /8 PM MST/ THIS EVENING TO
NOON CST /11 AM MST/ TUESDAY FOR NDZ019>022-034>036-042-045>047-
050.
FREEZING RAIN ADVISORY UNTIL 6 AM CST /5 AM MST/ TUESDAY FOR
NDZ001-009-010-017-018-033-041.
WINTER WEATHER ADVISORY UNTIL NOON CST TUESDAY FOR NDZ002-003-
011.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 PM CST
TUESDAY FOR NDZ004-005-012-013-023-025-037-048-051.
&&
$$
SHORT TERM...AJ
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1250 PM CST MON FEB 9 2015
.UPDATE...
ISSUED AT 1250 PM CST MON FEB 9 2015
FORECAST IN GOOD SHAPE FOR THE REST OF TODAY. NO CHANGES PLANNED
YET FOR TONIGHT INTO TUESDAY. HOWEVER...HERE ARE THE LATEST THOUGHTS...
THE SOUTHERN WAVE APPEARS STRONG ON WATER VAPOR IMAGERY...AND
COULD VERY WELL CAUSE THE ABOVE FREEZING WARM LAYER ALOFT TO BE
FURTHER NORTH/EAST THAN WHAT THE MODELS ARE INDICATING. THIS WOULD
SPREAD FREEZING RAIN INTO MUCH SOUTHEAST NORTH DAKOTA. THIS IN
ONLY A POSSIBILITY...AND WILL ATTEMPT TO ASSESS THIS FURTHER WITH
THE NEXT UPDATE. MAY NEED A FREEZING RAIN ADVISORY FOR THESE PARTS
OF THE REGION.
TO THE NORTH AND EAST...SNOWFALL APPEARS CERTAIN ON TUESDAY...BUT
AMOUNTS STILL THE BIG QUESTION. HI-RES MODELS ALL INDICATE TWO
SEPARATE AREAS OF HIGHER QPF...RELATED TO WHERE EACH SHORTWAVE
TRACKS. THINKING MOST AREAS WILL RECEIVE 1-3 INCHES...BUT WHERE
THE STRONGER FORCING IS LOCATED (AT THIS POINT LIKELY WEST CENTRAL
MINNESOTA....AND NEAR THE INTERNATIONAL BORDER) SHOULD GET 3-5
INCHES.
THEN...20-30MPH WINDS TUESDAY NIGHT COULD BLOW THE SNOW AROUND.
NOT SURE HOW TO MESSAGE OR HANDLE THIS EVENT...AND WHETHER OR NOT
HEADLINES ARE REQUIRED AT THIS POINT. WILL ATTEMPT TO MAKE MORE
SENSE OF THIS SYSTEM WITH THE NEXT UPDATE AS OTHER OFFICES ARE
BEGINNING TO ISSUE HEADLINES.
UPDATE ISSUED AT 958 AM CST MON FEB 9 2015
NOT MUCH FOR CONCERNS TODAY...ALTHOUGH MAX TEMPS MAY NOT GET QUITE
AS WARM CONSIDERING WEAK FLOW...COLDER AIRMASS...AND CLOUD COVER.
SOUTHERLY LOW-LEVEL FLOW/WEAK WARM AIR ADVECTION AHEAD OF THE
TUESDAY SYSTEM BEGINS LATER THIS AFTERNOON INTO THE EVENING. THIS
WEAK FORCING MAY BE ENOUGH TO PRODUCE FLURRIES AND/OR FZDZ AHEAD
OF THE STRONGER FORCING LATER TONIGHT AND TUESDAY. THE RAP AND
OTHER VARIOUS MODELS ARE INDICATING VERY WEAK QPF IN THIS REGIME.
THE MAIN CONCERN WITH THIS SCENARIO WOULD BE THE FZDZ POTENTIAL.
THERE IS DRY AIR ALOFT...AND THE BEST CHANCE FOR SUPERCOOLED
WATER DROPLETS WOULD BE ACROSS THE SOUTHERN FA WHERE THE
AVERAGE TEMPERATURE IN THE LOW LEVEL SATURATED LAYER IS WARMER
(<-6C). DID INCLUDE PATCHY FZDZ HERE...AND MAY NEED TO CONSIDER
INCREASING THE COVERAGE IF THE SITUATION WARRANTS.
WILL BE TAKING A CLOSER LOOK AT TUESDAY SNOWFALL AMOUNTS AND WIND
SPEEDS TUESDAY NIGHT WITH LATER UPDATES. THE THINKING REMAINS
RELATIVELY THE SAME AT THIS POINT.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 321 AM CST MON FEB 9 2015
ONE WEAK SHORT WAVE MOVING THRU NRN MN ATTM. A NARROW AREA OF SNOW
SHOWERS WITH THIS FEATURE THROUGH PARTS OF NE ND/NW MN. CLOUDS
WILL HOLD TODAY. COULD BE A FEW FLURRIES OVER NW MN LEFTOVER FROM
THE EXITING SHORT WAVE AND OVER NE ND/DVL BASIN UNDER STRATOCU
DECK. ROLLA-BRANDON MB AND A FEW OTHER SPOTS HAVE HAD -SN PAST FEW
HOURS. OTHERWISE DRY TODAY AND INTO THIS EVENING. LARGE UPPER
LEVEL STORM SYSTEM OFF OREGON COAST WITH A POTENT SHORT WAVE
MOVING INTO NW NEVADA AND ERN OREGON. A PIECE OF THIS SYSTEM WILL
MOVE EAST AND INTO THE NRN PLAINS TUESDAY. MODELS REMAIN DIFFERENT
IN QPF LOCATION AND AMOUNTS...BUT NOT BY HUGE AMOUNTS. OVERALL
TREND IS FOR A BIT NORTHWARD PLACEMENT OF SFC LOW AND QPF. INITIAL
SFC LOW WILL MOVE THRU NRN MT INTO NW ND BY 12Z TUES. A BAND OF
WARM ADVECTION PRECIPITATION WILL OCCUR FROM THE LOW SOUTH-
SOUTHEASTWARD AS IT MOVES INTO WRN ND TONIGHT AND REACHES DVL
BASIN PRIMARILY AFTER 09Z AND THE RRV NR 12Z TUE. BACKED OFF ON
TIMING OF POPS FOR A BIT DELAYED EASTWARD MOVEMENT. AS MAIN SFC
LOW MOVES INTO NORTH CENTRAL ND TUESDAY MORNING A SECOND LOW WILL
BE IN CNTRL-ERN SD. A SECOND PIECE OF WARM ADV AND FRONTOGENETIC
FORCING WILL BE DEVELOPING TUESDAY MORNING IN WCNTRL MN AS NRN LOW
WEAKENS A BIT. THUS MODELS DO HAVE TWO AREAS OF MAIN PRECIPITATION
ONE IN NE ND/SRN MANITOBA AND THE OTHER SOMEWHERE IN WCNTRL OR
CNTRL MN TUESDAY. PRECIPITATION MOVES EAST PRETTY QUICKLY WITH
SOME WRAPAROUND LIGHT SNOW LASTING INTO NE ND/NW MN TUESDAY NIGHT.
PTYPE ISSUES APPEAR REGULATED TO JUST SOUTHWEST OF THE FCST AREA.
USING GFS THERMAL PROFILES...A BRIEF PD OF FZRA OR SLEET PSBL IN
FAR SOUTHWEST CORNER OF FCST AREA NR 12Z BUT OVERALL THERMAL
PROFILES AND BUFKIT AND SREF PLUMES SHOW A SNOW EVENT FOR OUR
FORECAST AREA. HOW MUCH? SW FCST AREA GETS DRY SLOTTED LIKELY WITH
ONLY A BRIEF PD OF PRECIP AND IF SNOW ONLY AMOUNTS TO 1-2 INCHES
WEST AND SOUTH OF FARGO. A BIT HEAVIER SNOW AREA DEVELOPS OVER
PARTS OF CNTRL MN AND THEN INTO NW MN/NE ND WHERE SNOWFALL OF 3-4
INCHES SEEMS MORE LIKELY. SO BASED ON THIS SOME PARTS OF THE FCST
AREA WILL HAVE ADVISORY LEVEL SNOWFALL. WITHOUT MUCH FREEZING
PRECIPITATION PARTS OF SE ND MAY NOT HAVE ADVISORY LEVEL SNOWFALL.
WITH STILL QUESTIONS ON PRECIP AND STILL PSBL FURTHER SHIFT NORTH
OF PRECIP AND WITH MOST OF THE PRECIP NOT FALLING TIL NR 12Z AND
AFTERWARDS ON TUESDAY...HELD OFF ON ANY ADVISORY HEADLINES. COORD
WITH ABR/MPX/DLH ON THIS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 321 AM CST MON FEB 9 2015
LIGHT SNOW WILL END IN NE ND/NW MN OVERNIGHT TUESDAY NIGHT.
WEDNESDAY TO SUNDAY...THE END OF THE WEEK AND INTO NEXT WEEKEND
DOMINATED WITH COLD TEMPS AND DRY WEATHER ACROSS THE NORTHERN
PLAINS. STRONG SFC HIGH PRESSURE BUILDS INTO THE REGION WEDNESDAY IN
THE WAKE OF THE TUESDAY STORM SYSTEM AS 500MB FLOW BECOMES NORTHERLY
BRINGING DOWN THE ARCTIC AIRMASS. SINGLE DIGITS HIGHS EXPECTED WED
AND THURSDAY BEFORE SOME TEMP MODERATION WITH WEAK WAA THURSDAY
NIGHT INTO EARLY FRIDAY BEFORE THE NEXT ARCTIC 1040MB PLUS SFC HIGH
BUILDS INTO THE RED RIVER VALLEY REESTABLISHING THE SINGLE DIGITS
HIGHS FOR THE WEEKEND. ONLY POP CHANCE REMAINS MINOR...ASSOCIATED
WITH THE WEAK WAA FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1250 PM CST MON FEB 9 2015
PRETTY WEAK WINDS OUT THERE RIGHT NOW BUT THESE WILL BEGIN TO TURN
EAST-SE BY LATE AFTERNOON ACROSS THE KDVL REGION. THIS MAY HELP TO
IMPROVE THE VSBYS DUE TO FOG ACROSS THAT AREA SOME BUT WILL HAVE TO
SEE. CAN EXPECT THE EAST-SE WIND SWITCH IN OTHER AREAS LATE TONIGHT
INTO EARLY TUE. PRETTY MUCH LEFT CEILINGS ABOUT WHERE THEY ARE AT
RIGHT NOW UNTIL THE LIGHT SNOW BEGINS TO MOVE IN. BEGIN TO BRING IN
THE LOWEST VSBYS FROM SNOW AROUND 12Z AT KFAR/KGFK AND A FEW HOURS
LATER FOR KTVF/KBJI.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...RIDDLE
LONG TERM...JK/RIDDLE
AVIATION...GODON
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1216 PM CST MON FEB 9 2015
.UPDATE...
ISSUED AT 1215 PM CST MON FEB 9 2015
ONCE AGAIN...EXTENDED THE DENSE FOG ADVISORY NOW THROUGH 00 UTC AS
SOUTHEAST UPSLOPE FLOW HAS LEAD TO NO IMPROVEMENT IN VISIBILITY
ACROSS MUCH OF WESTERN AND CENTRAL NORTH DAKOTA. OTHERWISE...THE
REMAINDER OF THE FORECAST INCLUDING THE UPCOMING MIXED
PRECIPITATION EVENT IS IN LINE WITH THE MAJORITY OF THE 12 UTC
GUIDANCE SUITE.
UPDATE ISSUED AT 844 AM CST MON FEB 9 2015
QUICK UPDATE TO EXTEND THE DENSE FOG ADVISORY UNTIL 18 UTC...AS
WEBCAM...SURFACE OBSERVATION AND SATELLITE TRENDS THROUGH 1430
UTC SHOW LITTLE IMPROVEMENT IN VISIBILITY THIS MORNING.
UPDATE ISSUED AT 615 AM CST MON FEB 9 2015
FOR MORNING UPDATE MAIN CHANGE WILL BE TO PUSH FOG COVERAGE FURTHER
EAST WITH REPORTS OF REDUCED VISIBILITY COMING IN THROUGHOUT THE
AREA. WILL KEEP DENSE FOG ADVISORY GOING IN THE WEST WITH SOME
OBS COMING IN AT ONE-QUARTER MILE. OTHERWISE...GOING FORECAST IS
IN GOOD SHAPE.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY AFTERNOON)
ISSUED AT 430 AM CST MON FEB 9 2015
A PLETHORA OF HEADLINES DOMINATES THE SHORT TERM PERIOD. FOR THE
NEAR TERM...NOW THROUGH 15Z MONDAY...WILL MAINTAIN CURRENT THE DENSE
FOG ADVISORY AS THE FOG/STRATUS LOOP AND SURFACE OBSERVATIONS SHOW
A VARIETY OF VISIBILITIES OF AT/NEAR OR BELOW ONE QUARTER OF A
MILE. LATEST HRRR CEILING FORECAST SHOWS CLOUDS LIFTING OVER THE
SOUTHWEST PORTION THIS AFTERNOON...FROM TROTTERS TO NEAR DICKINSON
AND HETTINGER. ALONG AND EAST OF THIS LINE...EXPECT STRATUS TO
CONTINUE.
LATEST WATER VAPOR IMAGERY SHOWS A RIDGE OVER THE NORTHERN ROCKIES
WITH A SERIES OF SHORTWAVES BEGINNING TO SHIFT THE RIDGE AND
FLATTEN IT ACROSS THE INTERMOUNTAIN WEST. THIS WILL LEAD TO A
FLATTER FLOW AS THE RIDGE COLLAPSES THIS AFTERNOON FOR WESTERN AND
CENTRAL NORTH DAKOTA. SURFACE LOW WILL EMERGE OVER CENTRAL MONTANA
THIS AFTERNOON IN RESPONSE TO THE SHORTWAVE ALOFT. MODEL SUITE IN
GOOD AGREEMENT WITH THE TRACK OF THIS LOW...SHIFTING EAST INTO
WESTERN NORTH DAKOTA BY 12Z TUESDAY AND INTO THE JAMES RIVER
VALLEY TUESDAY AFTERNOON. WARM AIR ALOFT WILL BE MAINTAINED UNTIL
THE LOW MOVES EAST TUESDAY AFTERNOON. BUFKIT TEMPERATURE PROFILES
CONSISTENT WITH LIGHT FREEZING RAIN DEVELOPING ACROSS THE
NORTHWEST EARLY MONDAY EVENING AND SPREADING INTO SOUTH CENTRAL
MONDAY NIGHT. DECENT OMEGA/LIFT IN THE 850-300MB LAYER FOR ALL
AREAS EXCEPT THE SOUTHWEST. MAIN BURST OF PRECIPITATION WILL OCCUR
AHEAD OF THE SURFACE LOW ALONG AND EAST OF A WARM FRONT MONDAY
EVENING AND MONDAY NIGHT. EXPECT A DRY SLOT TO PUNCH INTO
SOUTHWEST NORTH DAKOTA BY 12Z AND PUSH INTO SOUTH CENTRAL NORTH
DAKOTA TOWARD 15Z-18Z TUESDAY...WITH PRECIPITATION CONTINUING FROM
THE TURTLE MOUNTAINS SOUTH INTO THE JAMES RIVER VALLEY. AS THE LOW
PROGRESSES EAST...COLDER AIR WILL BE DRAWN FROM NORTH TO SOUTH
CHANGING ANY PRECIPITATION BACK TO SNOW TUESDAY AFTERNOON. HOWEVER
ACCUMULATIONS OUTSIDE OF THE TURTLE MOUNTAINS AND JAMES RIVER
VALLEY WILL BE LIGHT. HEAVIEST SNOWFALL WILL BE IN THE VICINITY OF
THE TURTLE MOUNTAINS WITH 3 TO 6 INCHES EXPECTED. LIGHT FREEZING
RAIN AND SNOW WILL CULMINATE THE FORECAST FOR THE NORTH CENTRAL
AND JAMES RIVER VALLEY...WHILE FREEZING RAIN WILL BE THE DOMINATE
FEATURE FOR THE NORTHWEST AND SOUTH CENTRAL.
OTHER THAN MINOR TIMING ISSUES WITH THIS SYSTEM...THE OVERALL THEME
OF LIGHT FREEZING RAIN AND SNOW HAS BEEN VERY MUCH CONSISTENT.
THUS HAVE DECIDED TO ISSUE HEADLINES BEGINNING MONDAY EVENING
THROUGH TUESDAY AFTERNOON. ESSENTIALLY A FREEZING RAIN ADVISORY IS
IN EFFECT FOR THE NORTHWEST AND SOUTH CENTRAL MONDAY EVENING INTO
TUESDAY MORNING. A WINTER WEATHER ADVISORY FOR LIGHT FREEZING RAIN
AND SNOW IS IN EFFECT FOR NORTH CENTRAL AND THE JAMES RIVER
VALLEY...WHILE A WINTER WEATHER ADVISORY FOR SNOW IS HEADLINED
IN/AROUND THE TURTLE MOUNTAINS. THE SOUTHWEST WILL EXPERIENCE A
CHANCE OF LIGHT FREEZING RAIN...BUT AT THIS POINT HAVE KEPT THE
ADVISORY HEADLINES WHERE POPS ARE LIKELY AND/OR CATEGORICAL.
TIMING AND AMOUNTS IN THE SOUTHWEST APPEAR BRIEF AND LIGHT. WILL
LET FUTURE SHIFTS TAKE A LOOK AT THIS FOR ANY CHANGES.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 430 AM CST MON FEB 9 2015
AFOREMENTIONED SYSTEM WILL GRADUALLY EXIT TOWARDS THE EAST TUESDAY
NIGHT WITH SNOW TAPERING...AND ANY ADDITIONAL ACCUMULATIONS BEING
MINIMAL.
COLD...DRY...AND BREEZY CONDITIONS EXPECTED WEDNESDAY AS FRIGID
AIRMASS CONTINUES TO SETTLE INTO THE AREA...WITH MANY LOCATIONS
SEEING SINGLE DIGIT HIGHS. SURFACE HIGH SETTLES THROUGH THE AREA
WEDNESDAY NIGHT BRINGING CALMING WINDS AND FRIGID
TEMPERATURES...PARTICULARLY OVER THE NORTH CENTRAL WHERE SOME
LOCATIONS MAY PUSH 20 BELOW FOR LOW TEMPS.
WARM FRONT TRIES TO LIFT INTO THE AREA THURSDAY BRINGING MUCH WARMER
TEMPS TO THE SOUTHWEST AND POSSIBLY SOME LIGHT SNOW TO THE CENTRAL
PART OF THE STATE. NEXT CHANCES FOR PRECIPITATION THEN COME DURING
THE WEEKEND INTO EARLY NEXT WEEK AS ACTIVE PATTERN WITH A VARIETY OF
WEAK WAVES PASSING THROUGH RETURNS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1215 PM CST MON FEB 9 2015
WIDESPREAD IFR TO LIFR CONDITIONS IN FOG AND STRATUS WILL CONTINUE
THIS AFTERNOON AND INTO THE EVENING ACROSS WESTERN AND CENTRAL
NORTH DAKOTA. ANOTHER ROUND OF LIGHT FREEZING RAIN WILL
OVERSPREAD KISN/KDIK/KBIS BETWEEN 00Z AND 06Z TUESDAY...WITH LIGHT
FREEZING RAIN AND SNOW DEVELOPING OVER KMOT AND LIGHT SNOW AND SLEET
AT KJMS MONDAY NIGHT. CONTINUED IFR CONDITIONS EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR
NDZ009-010-017>020-031>034-040>045.
FREEZING RAIN ADVISORY FROM 9 PM THIS EVENING TO NOON CST
TUESDAY FOR NDZ019>022-034>036-046-047-050.
FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
TUESDAY FOR NDZ001-009-010-017-018.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST
TUESDAY FOR NDZ002-003-011.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 PM CST
TUESDAY FOR NDZ004-005-012-013-023-025-037-048-051.
&&
$$
UPDATE...AYD
SHORT TERM...KS
LONG TERM...JJS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
958 AM CST MON FEB 9 2015
.UPDATE...
ISSUED AT 958 AM CST MON FEB 9 2015
NOT MUCH FOR CONCERNS TODAY...ALTHOUGH MAX TEMPS MAY NOT GET QUITE
AS WARM CONSIDERING WEAK FLOW...COLDER AIRMASS...AND CLOUD COVER.
SOUTHERLY LOW-LEVEL FLOW/WEAK WARM AIR ADVECTION AHEAD OF THE
TUESDAY SYSTEM BEGINS LATER THIS AFTERNOON INTO THE EVENING. THIS
WEAK FORCING MAY BE ENOUGH TO PRODUCE FLURRIES AND/OR FZDZ AHEAD
OF THE STRONGER FORCING LATER TONIGHT AND TUESDAY. THE RAP AND
OTHER VARIOUS MODELS ARE INDICATING VERY WEAK QPF IN THIS REGIME.
THE MAIN CONCERN WITH THIS SCENARIO WOULD BE THE FZDZ POTENTIAL.
THERE IS DRY AIR ALOFT...AND THE BEST CHANCE FOR SUPERCOOLED
WATER DROPLETS WOULD BE ACROSS THE SOUTHERN FA WHERE THE
AVERAGE TEMPERATURE IN THE LOW LEVEL SATURATED LAYER IS WARMER
(<-6C). DID INCLUDE PATCHY FZDZ HERE...AND MAY NEED TO CONSIDER
INCREASING THE COVERAGE IF THE SITUATION WARRANTS.
WILL BE TAKING A CLOSER LOOK AT TUESDAY SNOWFALL AMOUNTS AND WIND
SPEEDS TUESDAY NIGHT WITH LATER UPDATES. THE THINKING REMAINS
RELATIVELY THE SAME AT THIS POINT.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 321 AM CST MON FEB 9 2015
ONE WEAK SHORT WAVE MOVING THRU NRN MN ATTM. A NARROW AREA OF SNOW
SHOWERS WITH THIS FEATURE THROUGH PARTS OF NE ND/NW MN. CLOUDS
WILL HOLD TODAY. COULD BE A FEW FLURRIES OVER NW MN LEFTOVER FROM
THE EXITING SHORT WAVE AND OVER NE ND/DVL BASIN UNDER STRATOCU
DECK. ROLLA-BRANDON MB AND A FEW OTHER SPOTS HAVE HAD -SN PAST FEW
HOURS. OTHERWISE DRY TODAY AND INTO THIS EVENING. LARGE UPPER
LEVEL STORM SYSTEM OFF OREGON COAST WITH A POTENT SHORT WAVE
MOVING INTO NW NEVADA AND ERN OREGON. A PIECE OF THIS SYSTEM WILL
MOVE EAST AND INTO THE NRN PLAINS TUESDAY. MODELS REMAIN DIFFERENT
IN QPF LOCATION AND AMOUNTS...BUT NOT BY HUGE AMOUNTS. OVERALL
TREND IS FOR A BIT NORTHWARD PLACEMENT OF SFC LOW AND QPF. INITIAL
SFC LOW WILL MOVE THRU NRN MT INTO NW ND BY 12Z TUES. A BAND OF
WARM ADVECTION PRECIPITATION WILL OCCUR FROM THE LOW SOUTH-
SOUTHEASTWARD AS IT MOVES INTO WRN ND TONIGHT AND REACHES DVL
BASIN PRIMARILY AFTER 09Z AND THE RRV NR 12Z TUE. BACKED OFF ON
TIMING OF POPS FOR A BIT DELAYED EASTWARD MOVEMENT. AS MAIN SFC
LOW MOVES INTO NORTH CENTRAL ND TUESDAY MORNING A SECOND LOW WILL
BE IN CNTRL-ERN SD. A SECOND PIECE OF WARM ADV AND FRONTOGENETIC
FORCING WILL BE DEVELOPING TUESDAY MORNING IN WCNTRL MN AS NRN LOW
WEAKENS A BIT. THUS MODELS DO HAVE TWO AREAS OF MAIN PRECIPITATION
ONE IN NE ND/SRN MANITOBA AND THE OTHER SOMEWHERE IN WCNTRL OR
CNTRL MN TUESDAY. PRECIPITATION MOVES EAST PRETTY QUICKLY WITH
SOME WRAPAROUND LIGHT SNOW LASTING INTO NE ND/NW MN TUESDAY NIGHT.
PTYPE ISSUES APPEAR REGULATED TO JUST SOUTHWEST OF THE FCST AREA.
USING GFS THERMAL PROFILES...A BRIEF PD OF FZRA OR SLEET PSBL IN
FAR SOUTHWEST CORNER OF FCST AREA NR 12Z BUT OVERALL THERMAL
PROFILES AND BUFKIT AND SREF PLUMES SHOW A SNOW EVENT FOR OUR
FORECAST AREA. HOW MUCH? SW FCST AREA GETS DRY SLOTTED LIKELY WITH
ONLY A BRIEF PD OF PRECIP AND IF SNOW ONLY AMOUNTS TO 1-2 INCHES
WEST AND SOUTH OF FARGO. A BIT HEAVIER SNOW AREA DEVELOPS OVER
PARTS OF CNTRL MN AND THEN INTO NW MN/NE ND WHERE SNOWFALL OF 3-4
INCHES SEEMS MORE LIKELY. SO BASED ON THIS SOME PARTS OF THE FCST
AREA WILL HAVE ADVISORY LEVEL SNOWFALL. WITHOUT MUCH FREEZING
PRECIPITATION PARTS OF SE ND MAY NOT HAVE ADVISORY LEVEL SNOWFALL.
WITH STILL QUESTIONS ON PRECIP AND STILL PSBL FURTHER SHIFT NORTH
OF PRECIP AND WITH MOST OF THE PRECIP NOT FALLING TIL NR 12Z AND
AFTERWARDS ON TUESDAY...HELD OFF ON ANY ADVISORY HEADLINES. COORD
WITH ABR/MPX/DLH ON THIS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 321 AM CST MON FEB 9 2015
LIGHT SNOW WILL END IN NE ND/NW MN OVERNIGHT TUESDAY NIGHT.
WEDNESDAY TO SUNDAY...THE END OF THE WEEK AND INTO NEXT WEEKEND
DOMINATED WITH COLD TEMPS AND DRY WEATHER ACROSS THE NORTHERN
PLAINS. STRONG SFC HIGH PRESSURE BUILDS INTO THE REGION WEDNESDAY IN
THE WAKE OF THE TUESDAY STORM SYSTEM AS 500MB FLOW BECOMES NORTHERLY
BRINGING DOWN THE ARCTIC AIRMASS. SINGLE DIGITS HIGHS EXPECTED WED
AND THURSDAY BEFORE SOME TEMP MODERATION WITH WEAK WAA THURSDAY
NIGHT INTO EARLY FRIDAY BEFORE THE NEXT ARCTIC 1040MB PLUS SFC HIGH
BUILDS INTO THE RED RIVER VALLEY REESTABLISHING THE SINGLE DIGITS
HIGHS FOR THE WEEKEND. ONLY POP CHANCE REMAINS MINOR...ASSOCIATED
WITH THE WEAK WAA FRIDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 706 AM CST MON FEB 9 2015
A BIT DRIER LOW LEVEL AIR INTO THE NRN RRV HAS HELPED SCOUR OUT
THE MVFR CLOUDS FOR THE MOST PART LEAVING LOW END VFR CIGS.
OTHERWISE TO THE EAST AND WEST MVFR CIGS WITH PATCHY IFR CIGS AND
LIGHT FOG DVL BASIN. LOOK FOR A GENERAL LIGHT NORTH WIND TO TURN
MORE NORTHEAST AND THEN EAST BY TONIGHT WITH CLOUD COVER
CONTINUING. TREND WILL BE FOR LOWEST CIGS TO BE WEST OF THE RED
RIVER VALLEY WITH IN GENERAL MVFR CIGS RRV AND INTO MN. THREAT FOR
SNOW MOVES INTO DVL REGION BY 07Z TUES AND INTO THE GFK/FAR AREA
BY 10-11Z TUES.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...RIDDLE
LONG TERM...JK/RIDDLE
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
844 AM CST MON FEB 9 2015
.UPDATE...
ISSUED AT 844 AM CST MON FEB 9 2015
QUICK UPDATE TO EXTEND THE DENSE FOG ADVISORY UNTIL 18 UTC...AS
WEBCAM...SURFACE OBSERVATION AND SATELLITE TRENDS THROUGH 1430
UTC SHOW LITTLE IMPROVEMENT IN VISIBILITY THIS MORNING.
UPDATE ISSUED AT 615 AM CST MON FEB 9 2015
FOR MORNING UPDATE MAIN CHANGE WILL BE TO PUSH FOG COVERAGE FURTHER
EAST WITH REPORTS OF REDUCED VISIBILITY COMING IN THROUGHOUT THE
AREA. WILL KEEP DENSE FOG ADVISORY GOING IN THE WEST WITH SOME
OBBS COMING IN AT ONE-QUARTER MILE. OTHERWISE...GOING FORECAST IS
IN GOOD SHAPE.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY AFTERNOON)
ISSUED AT 430 AM CST MON FEB 9 2015
A PLETHORA OF HEADLINES DOMINATES THE SHORT TERM PERIOD. FOR THE
NEAR TERM...NOW THROUGH 15Z MONDAY...WILL MAINTAIN CURRENT THE DENSE
FOG ADVISORY AS THE FOG/STRATUS LOOP AND SURFACE OBSERVATIONS SHOW
A VARIETY OF VISIBILITIES OF AT/NEAR OR BELOW ONE QUARTER OF A
MILE. LATEST HRRR CEILING FORECAST SHOWS CLOUDS LIFTING OVER THE
SOUTHWEST PORTION THIS AFTERNOON...FROM TROTTERS TO NEAR DICKINSON
AND HETTINGER. ALONG AND EAST OF THIS LINE...EXPECT STRATUS TO
CONTINUE.
LATEST WATER VAPOR IMAGERY SHOWS A RIDGE OVER THE NORTHERN ROCKIES
WITH A SERIES OF SHORTWAVES BEGINNING TO SHIFT THE RIDGE AND
FLATTEN IT ACROSS THE INTERMOUNTAIN WEST. THIS WILL LEAD TO A
FLATTER FLOW AS THE RIDGE COLLAPSES THIS AFTERNOON FOR WESTERN AND
CENTRAL NORTH DAKOTA. SURFACE LOW WILL EMERGE OVER CENTRAL MONTANA
THIS AFTERNOON IN RESPONSE TO THE SHORTWAVE ALOFT. MODEL SUITE IN
GOOD AGREEMENT WITH THE TRACK OF THIS LOW...SHIFTING EAST INTO
WESTERN NORTH DAKOTA BY 12Z TUESDAY AND INTO THE JAMES RIVER
VALLEY TUESDAY AFTERNOON. WARM AIR ALOFT WILL BE MAINTAINED UNTIL
THE LOW MOVES EAST TUESDAY AFTERNOON. BUFKIT TEMPERATURE PROFILES
CONSISTENT WITH LIGHT FREEZING RAIN DEVELOPING ACROSS THE
NORTHWEST EARLY MONDAY EVENING AND SPREADING INTO SOUTH CENTRAL
MONDAY NIGHT. DECENT OMEGA/LIFT IN THE 850-300MB LAYER FOR ALL
AREAS EXCEPT THE SOUTHWEST. MAIN BURST OF PRECIPITATION WILL OCCUR
AHEAD OF THE SURFACE LOW ALONG AND EAST OF A WARM FRONT MONDAY
EVENING AND MONDAY NIGHT. EXPECT A DRY SLOT TO PUNCH INTO
SOUTHWEST NORTH DAKOTA BY 12Z AND PUSH INTO SOUTH CENTRAL NORTH
DAKOTA TOWARD 15Z-18Z TUESDAY...WITH PRECIPITATION CONTINUING FROM
THE TURTLE MOUNTAINS SOUTH INTO THE JAMES RIVER VALLEY. AS THE LOW
PROGRESSES EAST...COLDER AIR WILL BE DRAWN FROM NORTH TO SOUTH
CHANGING ANY PRECIPITATION BACK TO SNOW TUESDAY AFTERNOON. HOWEVER
ACCUMULATIONS OUTSIDE OF THE TURTLE MOUNTAINS AND JAMES RIVER
VALLEY WILL BE LIGHT. HEAVIEST SNOWFALL WILL BE IN THE VICINITY OF
THE TURTLE MOUNTAINS WITH 3 TO 6 INCHES EXPECTED. LIGHT FREEZING
RAIN AND SNOW WILL CULMINATE THE FORECAST FOR THE NORTH CENTRAL
AND JAMES RIVER VALLEY...WHILE FREEZING RAIN WILL BE THE DOMINATE
FEATURE FOR THE NORTHWEST AND SOUTH CENTRAL.
OTHER THAN MINOR TIMING ISSUES WITH THIS SYSTEM...THE OVERALL THEME
OF LIGHT FREEZING RAIN AND SNOW HAS BEEN VERY MUCH CONSISTENT.
THUS HAVE DECIDED TO ISSUE HEADLINES BEGINNING MONDAY EVENING
THROUGH TUESDAY AFTERNOON. ESSENTIALLY A FREEZING RAIN ADVISORY IS
IN EFFECT FOR THE NORTHWEST AND SOUTH CENTRAL MONDAY EVENING INTO
TUESDAY MORNING. A WINTER WEATHER ADVISORY FOR LIGHT FREEZING RAIN
AND SNOW IS IN EFFECT FOR NORTH CENTRAL AND THE JAMES RIVER
VALLEY...WHILE A WINTER WEATHER ADVISORY FOR SNOW IS HEADLINED
IN/AROUND THE TURTLE MOUNTAINS. THE SOUTHWEST WILL EXPERIENCE A
CHANCE OF LIGHT FREEZING RAIN...BUT AT THIS POINT HAVE KEPT THE
ADVISORY HEADLINES WHERE POPS ARE LIKELY AND/OR CATEGORICAL.
TIMING AND AMOUNTS IN THE SOUTHWEST APPEAR BRIEF AND LIGHT. WILL
LET FUTURE SHIFTS TAKE A LOOK AT THIS FOR ANY CHANGES.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 430 AM CST MON FEB 9 2015
AFOREMENTIONED SYSTEM WILL GRADUALLY EXIT TOWARDS THE EAST TUESDAY
NIGHT WITH SNOW TAPERING...AND ANY ADDITIONAL ACCUMULATIONS BEING
MINIMAL.
COLD...DRY...AND BREEZY CONDITIONS EXPECTED WEDNESDAY AS FRIGID
AIRMASS CONTINUES TO SETTLE INTO THE AREA...WITH MANY LOCATIONS
SEEING SINGLE DIGIT HIGHS. SURFACE HIGH SETTLES THROUGH THE AREA
WEDNESDAY NIGHT BRINGING CALMING WINDS AND FRIGID
TEMPERATURES...PARTICULARLY OVER THE NORTH CENTRAL WHERE SOME
LOCATIONS MAY PUSH 20 BELOW FOR LOW TEMPS.
WARM FRONT TRIES TO LIFT INTO THE AREA THURSDAY BRINGING MUCH WARMER
TEMPS TO THE SOUTHWEST AND POSSIBLY SOME LIGHT SNOW TO THE CENTRAL
PART OF THE STATE. NEXT CHANCES FOR PRECIPITATION THEN COME DURING
THE WEEKEND INTO EARLY NEXT WEEK AS ACTIVE PATTERN WITH A VARIETY OF
WEAK WAVES PASSING THROUGH RETURNS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 842 AM CST MON FEB 9 2015
LATEST SATELLITE IMAGERY AND SURFACE OBSERVATIONS CONTINUE TO
INDICATE LIFR CIGS AND LIFR/IFR VSBYS. CIGS ARE EXPECTED TO IMPROVE
TO VFR OVER SOUTHWEST NORTH DAKOTA...APPROACHING KDIK BY MID
AFTERNOON. THUS HAVE LIFTED CIGS AT KDIK TO MVFR...BUT THIS WILL
NEED SOME ADJUSTING AS THE MORNING PROGRESSES. OTHERWISE...STRATUS
DOMINATES THE REMAINING TERMINALS WITH IFR CIGS AND MVFR VSBYS
MONDAY AFTERNOON. ANOTHER ROUND OF LIGHT FREEZING RAIN WILL
OVERSPREAD KISN/KDIK/KBIS BETWEEN 00Z AND 06Z TUESDAY...WITH LIGHT
FREEZING RAIN AND SNOW DEVELOPING OVER KMOT AND LIGHT SNOW AND SLEET
AT KJMS MONDAY NIGHT. CIGS WILL DETERIORATE BACK TO LIFR/IFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR NDZ009-
010-017>020-031>034-040>045.
FREEZING RAIN ADVISORY FROM 9 PM THIS EVENING TO NOON CST
TUESDAY FOR NDZ019>022-034>036-046-047-050.
FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
TUESDAY FOR NDZ001-009-010-017-018.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST
TUESDAY FOR NDZ002-003-011.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 PM CST
TUESDAY FOR NDZ004-005-012-013-023-025-037-048-051.
&&
$$
UPDATE...AYD
SHORT TERM...KS
LONG TERM...JJS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
622 AM CST MON FEB 9 2015
.UPDATE...
ISSUED AT 615 AM CST MON FEB 9 2015
FOR MORNING UPDATE MAIN CHANGE WILL BE TO PUSH FOG COVERAGE FURTHER
EAST WITH REPORTS OF REDUCED VISIBILITY COMING IN THROUGHOUT THE
AREA. WILL KEEP DENSE FOG ADVISORY GOING IN THE WEST WITH SOME
OBBS COMING IN AT ONE-QUARTER MILE. OTHERWISE...GOING FORECAST IS
IN GOOD SHAPE.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY AFTERNOON)
ISSUED AT 430 AM CST MON FEB 9 2015
A PLETHORA OF HEADLINES DOMINATES THE SHORT TERM PERIOD. FOR THE
NEAR TERM...NOW THROUGH 15Z MONDAY...WILL MAINTAIN CURRENT THE DENSE
FOG ADVISORY AS THE FOG/STRATUS LOOP AND SURFACE OBSERVATIONS SHOW
A VARIETY OF VISIBILITIES OF AT/NEAR OR BELOW ONE QUARTER OF A
MILE. LATEST HRRR CEILING FORECAST SHOWS CLOUDS LIFTING OVER THE
SOUTHWEST PORTION THIS AFTERNOON...FROM TROTTERS TO NEAR DICKINSON
AND HETTINGER. ALONG AND EAST OF THIS LINE...EXPECT STRATUS TO
CONTINUE.
LATEST WATER VAPOR IMAGERY SHOWS A RIDGE OVER THE NORTHERN ROCKIES
WITH A SERIES OF SHORTWAVES BEGINNING TO SHIFT THE RIDGE AND
FLATTEN IT ACROSS THE INTERMOUNTAIN WEST. THIS WILL LEAD TO A
FLATTER FLOW AS THE RIDGE COLLAPSES THIS AFTERNOON FOR WESTERN AND
CENTRAL NORTH DAKOTA. SURFACE LOW WILL EMERGE OVER CENTRAL MONTANA
THIS AFTERNOON IN RESPONSE TO THE SHORTWAVE ALOFT. MODEL SUITE IN
GOOD AGREEMENT WITH THE TRACK OF THIS LOW...SHIFTING EAST INTO
WESTERN NORTH DAKOTA BY 12Z TUESDAY AND INTO THE JAMES RIVER
VALLEY TUESDAY AFTERNOON. WARM AIR ALOFT WILL BE MAINTAINED UNTIL
THE LOW MOVES EAST TUESDAY AFTERNOON. BUFKIT TEMPERATURE PROFILES
CONSISTENT WITH LIGHT FREEZING RAIN DEVELOPING ACROSS THE
NORTHWEST EARLY MONDAY EVENING AND SPREADING INTO SOUTH CENTRAL
MONDAY NIGHT. DECENT OMEGA/LIFT IN THE 850-300MB LAYER FOR ALL
AREAS EXCEPT THE SOUTHWEST. MAIN BURST OF PRECIPITATION WILL OCCUR
AHEAD OF THE SURFACE LOW ALONG AND EAST OF A WARM FRONT MONDAY
EVENING AND MONDAY NIGHT. EXPECT A DRY SLOT TO PUNCH INTO
SOUTHWEST NORTH DAKOTA BY 12Z AND PUSH INTO SOUTH CENTRAL NORTH
DAKOTA TOWARD 15Z-18Z TUESDAY...WITH PRECIPITATION CONTINUING FROM
THE TURTLE MOUNTAINS SOUTH INTO THE JAMES RIVER VALLEY. AS THE LOW
PROGRESSES EAST...COLDER AIR WILL BE DRAWN FROM NORTH TO SOUTH
CHANGING ANY PRECIPITATION BACK TO SNOW TUESDAY AFTERNOON. HOWEVER
ACCUMULATIONS OUTSIDE OF THE TURTLE MOUNTAINS AND JAMES RIVER
VALLEY WILL BE LIGHT. HEAVIEST SNOWFALL WILL BE IN THE VICINITY OF
THE TURTLE MOUNTAINS WITH 3 TO 6 INCHES EXPECTED. LIGHT FREEZING
RAIN AND SNOW WILL CULMINATE THE FORECAST FOR THE NORTH CENTRAL
AND JAMES RIVER VALLEY...WHILE FREEZING RAIN WILL BE THE DOMINATE
FEATURE FOR THE NORTHWEST AND SOUTH CENTRAL.
OTHER THAN MINOR TIMING ISSUES WITH THIS SYSTEM...THE OVERALL THEME
OF LIGHT FREEZING RAIN AND SNOW HAS BEEN VERY MUCH CONSISTENT.
THUS HAVE DECIDED TO ISSUE HEADLINES BEGINNING MONDAY EVENING
THROUGH TUESDAY AFTERNOON. ESSENTIALLY A FREEZING RAIN ADVISORY IS
IN EFFECT FOR THE NORTHWEST AND SOUTH CENTRAL MONDAY EVENING INTO
TUESDAY MORNING. A WINTER WEATHER ADVISORY FOR LIGHT FREEZING RAIN
AND SNOW IS IN EFFECT FOR NORTH CENTRAL AND THE JAMES RIVER
VALLEY...WHILE A WINTER WEATHER ADVISORY FOR SNOW IS HEADLINED
IN/AROUND THE TURTLE MOUNTAINS. THE SOUTHWEST WILL EXPERIENCE A
CHANCE OF LIGHT FREEZING RAIN...BUT AT THIS POINT HAVE KEPT THE
ADVISORY HEADLINES WHERE POPS ARE LIKELY AND/OR CATEGORICAL.
TIMING AND AMOUNTS IN THE SOUTHWEST APPEAR BRIEF AND LIGHT. WILL
LET FUTURE SHIFTS TAKE A LOOK AT THIS FOR ANY CHANGES.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 430 AM CST MON FEB 9 2015
AFOREMENTIONED SYSTEM WILL GRADUALLY EXIT TOWARDS THE EAST TUESDAY
NIGHT WITH SNOW TAPERING...AND ANY ADDITIONAL ACCUMULATIONS BEING
MINIMAL.
COLD...DRY...AND BREEZY CONDITIONS EXPECTED WEDNESDAY AS FRIGID
AIRMASS CONTINUES TO SETTLE INTO THE AREA...WITH MANY LOCATIONS
SEEING SINGLE DIGIT HIGHS. SURFACE HIGH SETTLES THROUGH THE AREA
WEDNESDAY NIGHT BRINGING CALMING WINDS AND FRIGID
TEMPERATURES...PARTICULARLY OVER THE NORTH CENTRAL WHERE SOME
LOCATIONS MAY PUSH 20 BELOW FOR LOW TEMPS.
WARM FRONT TRIES TO LIFT INTO THE AREA THURSDAY BRINGING MUCH WARMER
TEMPS TO THE SOUTHWEST AND POSSIBLY SOME LIGHT SNOW TO THE CENTRAL
PART OF THE STATE. NEXT CHANCES FOR PRECIPITATION THEN COME DURING
THE WEEKEND INTO EARLY NEXT WEEK AS ACTIVE PATTERN WITH A VARIETY OF
WEAK WAVES PASSING THROUGH RETURNS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 615 AM CST MON FEB 9 2015
LATEST SATELLITE IMAGERY AND SURFACE OBSERVATIONS CONTINUE TO
INDICATE LIFR CIGS AND LIFR/IFR VSBYS. CIGS ARE EXPECTED TO IMPROVE
TO VFR OVER SOUTHWEST NORTH DAKOTA...APPROACHING KDIK BY MID
AFTERNOON. THUS HAVE LIFTED CIGS AT KDIK TO MVFR...BUT THIS WILL
NEED SOME ADJUSTING AS THE MORNING PROGRESSES. OTHERWISE...STRATUS
DOMINATES THE REMAINING TERMINALS WITH IFR CIGS AND MVFR VSBYS
MONDAY AFTERNOON. ANOTHER ROUND OF LIGHT FREEZING RAIN WILL
OVERSPREAD KISN/KDIK/KBIS BETWEEN 00Z AND 06Z TUESDAY...WITH LIGHT
FREEZING RAIN AND SNOW DEVELOPING OVER KMOT AND LIGHT SNOW AND SLEET
AT KJMS MONDAY NIGHT. CIGS WILL DETERIORATE BACK TO LIFR/IFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CST /9 AM MST/ THIS MORNING FOR
NDZ009-010-017>020-031>034-040>045.
FREEZING RAIN ADVISORY FROM 9 PM THIS EVENING TO NOON CST
TUESDAY FOR NDZ019>022-034>036-046-047-050.
FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
TUESDAY FOR NDZ001-009-010-017-018.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST
TUESDAY FOR NDZ002-003-011.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 PM CST
TUESDAY FOR NDZ004-005-012-013-023-025-037-048-051.
&&
$$
UPDATE...JJS
SHORT TERM...KS
LONG TERM...JJS
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
432 AM CST MON FEB 9 2015
.SHORT TERM...(TODAY THROUGH TUESDAY AFTERNOON)
ISSUED AT 430 AM CST MON FEB 9 2015
A PLETHORA OF HEADLINES DOMINATES THE SHORT TERM PERIOD. FOR THE
NEAR TERM...NOW THROUGH 15Z MONDAY...WILL MAINTAIN CURRENT THE DENSE
FOG ADVISORY AS THE FOG/STRATUS LOOP AND SURFACE OBSERVATIONS SHOW
A VARIETY OF VISIBILITIES OF AT/NEAR OR BELOW ONE QUARTER OF A
MILE. LATEST HRRR CEILING FORECAST SHOWS CLOUDS LIFTING OVER THE
SOUTHWEST PORTION THIS AFTERNOON...FROM TROTTERS TO NEAR DICKINSON
AND HETTINGER. ALONG AND EAST OF THIS LINE...EXPECT STRATUS TO
CONTINUE.
LATEST WATER VAPOR IMAGERY SHOWS A RIDGE OVER THE NORTHERN ROCKIES
WITH A SERIES OF SHORTWAVES BEGINNING TO SHIFT THE RIDGE AND
FLATTEN IT ACROSS THE INTERMOUNTAIN WEST. THIS WILL LEAD TO A
FLATTER FLOW AS THE RIDGE COLLAPSES THIS AFTERNOON FOR WESTERN AND
CENTRAL NORTH DAKOTA. SURFACE LOW WILL EMERGE OVER CENTRAL MONTANA
THIS AFTERNOON IN RESPONSE TO THE SHORTWAVE ALOFT. MODEL SUITE IN
GOOD AGREEMENT WITH THE TRACK OF THIS LOW...SHIFTING EAST INTO
WESTERN NORTH DAKOTA BY 12Z TUESDAY AND INTO THE JAMES RIVER
VALLEY TUESDAY AFTERNOON. WARM AIR ALOFT WILL BE MAINTAINED UNTIL
THE LOW MOVES EAST TUESDAY AFTERNOON. BUFKIT TEMPERATURE PROFILES
CONSISTENT WITH LIGHT FREEZING RAIN DEVELOPING ACROSS THE
NORTHWEST EARLY MONDAY EVENING AND SPREADING INTO SOUTH CENTRAL
MONDAY NIGHT. DECENT OMEGA/LIFT IN THE 850-300MB LAYER FOR ALL
AREAS EXCEPT THE SOUTHWEST. MAIN BURST OF PRECIPITATION WILL OCCUR
AHEAD OF THE SURFACE LOW ALONG AND EAST OF A WARM FRONT MONDAY
EVENING AND MONDAY NIGHT. EXPECT A DRY SLOT TO PUNCH INTO
SOUTHWEST NORTH DAKOTA BY 12Z AND PUSH INTO SOUTH CENTRAL NORTH
DAKOTA TOWARD 15Z-18Z TUESDAY...WITH PRECIPITATION CONTINUING FROM
THE TURTLE MOUNTAINS SOUTH INTO THE JAMES RIVER VALLEY. AS THE LOW
PROGRESSES EAST...COLDER AIR WILL BE DRAWN FROM NORTH TO SOUTH
CHANGING ANY PRECIPITATION BACK TO SNOW TUESDAY AFTERNOON. HOWEVER
ACCUMULATIONS OUTSIDE OF THE TURTLE MOUNTAINS AND JAMES RIVER
VALLEY WILL BE LIGHT. HEAVIEST SNOWFALL WILL BE IN THE VICINITY OF
THE TURTLE MOUNTAINS WITH 3 TO 6 INCHES EXPECTED. LIGHT FREEZING
RAIN AND SNOW WILL CULMINATE THE FORECAST FOR THE NORTH CENTRAL
AND JAMES RIVER VALLEY...WHILE FREEZING RAIN WILL BE THE DOMINATE
FEATURE FOR THE NORTHWEST AND SOUTH CENTRAL.
OTHER THAN MINOR TIMING ISSUES WITH THIS SYSTEM...THE OVERALL THEME
OF LIGHT FREEZING RAIN AND SNOW HAS BEEN VERY MUCH CONSISTENT.
THUS HAVE DECIDED TO ISSUE HEADLINES BEGINNING MONDAY EVENING
THROUGH TUESDAY AFTERNOON. ESSENTIALLY A FREEZING RAIN ADVISORY IS
IN EFFECT FOR THE NORTHWEST AND SOUTH CENTRAL MONDAY EVENING INTO
TUESDAY MORNING. A WINTER WEATHER ADVISORY FOR LIGHT FREEZING RAIN
AND SNOW IS IN EFFECT FOR NORTH CENTRAL AND THE JAMES RIVER
VALLEY...WHILE A WINTER WEATHER ADVISORY FOR SNOW IS HEADLINED
IN/AROUND THE TURTLE MOUNTAINS. THE SOUTHWEST WILL EXPERIENCE A
CHANCE OF LIGHT FREEZING RAIN...BUT AT THIS POINT HAVE KEPT THE
ADVISORY HEADLINES WHERE POPS ARE LIKELY AND/OR CATEGORICAL.
TIMING AND AMOUNTS IN THE SOUTHWEST APPEAR BRIEF AND LIGHT. WILL
LET FUTURE SHIFTS TAKE A LOOK AT THIS FOR ANY CHANGES.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 430 AM CST MON FEB 9 2015
AFOREMENTIONED SYSTEM WILL GRADUALLY EXIT TOWARDS THE EAST TUESDAY
NIGHT WITH SNOW TAPERING...AND ANY ADDITIONAL ACCUMULATIONS BEING
MINIMAL.
COLD...DRY...AND BREEZY CONDITIONS EXPECTED WEDNESDAY AS FRIGID
AIRMASS CONTINUES TO SETTLE INTO THE AREA...WITH MANY LOCATIONS
SEEING SINGLE DIGIT HIGHS. SURFACE HIGH SETTLES THROUGH THE AREA
WEDNESDAY NIGHT BRINGING CALMING WINDS AND FRIGID
TEMPERATURES...PARTICULARLY OVER THE NORTH CENTRAL WHERE SOME
LOCATIONS MAY PUSH 20 BELOW FOR LOW TEMPS.
WARM FRONT TRIES TO LIFT INTO THE AREA THURSDAY BRINGING MUCH WARMER
TEMPS TO THE SOUTHWEST AND POSSIBLY SOME LIGHT SNOW TO THE CENTRAL
PART OF THE STATE. NEXT CHANCES FOR PRECIPITATION THEN COME DURING
THE WEEKEND INTO EARLY NEXT WEEK AS ACTIVE PATTERN WITH A VARIETY OF
WEAK WAVES PASSING THROUGH RETURNS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 430 AM CST MON FEB 9 2015
SATELLITE IMAGERY AND SURFACE OBSERVATIONS CONTINUE TO INDICATE
IFR CIGS AND LIFR VSBYS. CIGS ARE EXPECTED TO LIFT TO VFR IN
SOUTHWEST NORTH DAKOTA BY MID AFTERNOON...WITH DICKINSON ON THE
FRINGES OF SOME CLEARING. THE REST OF THE TERMINALS WILL REMAIN
LOCKED IN THE STRATUS WITH IFR CIGS. EXPECT LIGHT FREEZING RAIN TO
OVERSPREAD KISN/KDIK/KBIS SHORTLY AFTER 00Z TUESDAY...WITH LIGHT FREEZING
RAIN AND SNOW DEVELOPING OVER KMOT AND KJMS. THIS WILL CONTINUE
THROUGH 12Z TUESDAY AND BEYOND.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CST /9 AM MST/ THIS MORNING FOR
NDZ009-010-017>020-031>034-040>045.
FREEZING RAIN ADVISORY FROM 9 PM THIS EVENING TO NOON CST
TUESDAY FOR NDZ019>022-034>036-046-047-050.
FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
TUESDAY FOR NDZ001-009-010-017-018.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST
TUESDAY FOR NDZ002-003-011.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 PM CST
TUESDAY FOR NDZ004-005-012-013-023-025-037-048-051.
&&
$$
SHORT TERM...KS
LONG TERM...JJS
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1140 PM CST SUN FEB 8 2015
.UPDATE...
ISSUED AT 1140 PM CST SUN FEB 8 2015
CURRENT FORECAST ENCOMPASSING THE DENSE FOG ADVISORY AND PATCHY
FREEZING DRIZZLE REMAINS ON TRACK. LATEST FOG/STRATUS IMAGERY
LOOP AND SURFACE OBSERVATIONS CONTINUE TO SHOW A WIDE AREA OF
DENSE FOG/STRATUS OVER THE WEST ALONG WITH PATCHY FREEZING DRIZZLE
WEST AND CENTRAL. THE LATEST HRRR CONTINUES TO INDICATE THAT THIS
WILL VERY SOON REACH THE FAR SOUTHWEST WHICH HAS REMAINED
RELATIVELY CLEAR. CONCUR WITH THIS IDEA AS SATELLITE SHOWS THE
STRATUS FILTERING INTO THE FAR SOUTHWEST AT THIS MOMENT. THUS NO
CHANGES TO THIS UPDATE AS THE HRRR/RAP13 LOW LEVEL MOISTURE
PROFILES MAINTAIN THE CLOUDS THROUGH MONDAY.
ATTENTION TURNS TO MONDAY EVENING THROUGH TUESDAY. BASED ON THE
LATEST 00Z DATA AND BUFKIT TEMPERATURE PROFILES....WILL BE FOCUSING
IN ON FREEZING RAIN FOR MOST OF WESTERN AND CENTRAL NORTH DAKOTA
MONDAY EVENING/NIGHT...AND SNOW IN THE NORTHEAST.
UPDATE ISSUED AT 941 PM CST SUN FEB 8 2015
MAIN UPDATE WAS FOR DENSE FOG CONCERNS IN THE WEST. WENT BACK AND
ADJUSTED TEMPERATURES DOWN JUST A BIT IN THE EAST WHERE WE WERE
ALREADY CLOSE TO OVERNIGHT LOWS. WITH OVERCAST SKIES DONT THINK WE
WILL DROP MUCH BUT WITH COLD NORTH TO NORTHEAST SURFACE FLOW OVER
THE FAR EASTERN COUNTIES...THINK THEY SHOULD DROP A FEW MORE
DEGREES. STILL SOME VERY LIGHT PRECIPITATION OVER THE FAR EASTERN
ZONES. KEPT THE SLIGHT CHANCE OF MIXED PRECIP. RECENT REPORT OF
SOME LIGHT FREEZING DRIZZLE IN BISMARCK. WILL ADD A MENTION OF
PATCHY FREEZING DRIZZLE WHEREVER WE HAVE FOG.
UPDATE ISSUED AT 847 PM CST SUN FEB 8 2015
MAIN FORECAST ISSUE LATE THIS EVENING WILL BE FOG AND WHAT TO DO
WITH THE CURRENT DENSE FOG ADVISORY. AFTER LOOKING OVER LATEST
OBSERVATIONS...WX CAMS...ROAD REPORT AND LATEST SATELLITE...HAVE
DECIDED TO EXPAND THE CURRENT ADVISORY TO INCLUDE THE REMAINDER OF
SOUTHWEST NORTH DAKOTA. VISIBILITIES ON THE LEADING EDGE OF THE
STRATUS EXPANDING SOUTHWEST ARE AROUND A QUARTER MILE. LATEST
RAP/HRRR SHOW THE STRATUS EXPANDING THROUGH ALL OF THE SOUTHWEST
LATE TONIGHT. FARTHER NORTH AND EAST...VISIBILITIES HAVE REMAINED
LOW FROM DICKINSON AND GLEN ULLIN NORTH THROUGH DUNN COUNTY.
CURRENT WX CAM SHOT FROM NEW TOWN LOOKS LIKE DENSE FOG. LATEST
ROAD REPORT ALSO INDICATES VISIBILITIES DOWN TO A QUARTER MILE
ACROSS PARTS OF WILLIAMS COUNTY ALONG HIGHWAY 2. THOUGHT WE MIGHT
BE ABLE TO DROP THE NORTHERN PORTIONS OF THE ADVISORY...AND WE MAY
BE ABLE TO LATER BUT AT THIS TIME...ENOUGH VERIFICATION TO KEEP IT
GOING. THINK THE FOG SHOULD SPREAD INTO PORTIONS OF BOWMAN AND
SLOPE COUNTY BEFORE MIDNIGHT SO INSTEAD OF ADDING THEM LATER WILL
INCLUDE THEM NOW. LATEST HRRR DOES INDICATE LOWEST VISIBILITIES
ALONG THE WESTERN FRINGE OF THE STRATUS LATE TONIGHT INTO MONDAY
MORNING. WHICH WILL BE OVER THIS AREA BY THEN. OTHERWISE...SPREAD
MENTION OF PATCHY FOG TO MOST AREAS ALONG AND WEST OF THE HIGHWAY
83 CORRIDOR.
UPDATE ISSUED AT 547 PM CST SUN FEB 8 2015
WILL EXTEND THE DENSE FOG ADVISORY THROUGH 03 UTC. AREAS OF DENSE
FOG STILL NOTED ON WEATHER CAMS OVER MAINLY DUNN COUNTY...BUT DOES
EXTEND NORTH INTO EASTERN WILLIAMS AND WESTERN MOUNTRAIL. ALSO
SOUTH INTO FAR WESTERN STARK AND PORTIONS OF MERCER...OLIVER...
MORTON AND GRANT COUNTIES. LATEST HRRR SHOWS THE AREA OF LOWEST
VISIBILITIES SHIFTING FARTHER SOUTH INTO SOUTHWEST NORTH DAKOTA BY
MID EVENING. WILL NEED TO MONITOR AND POSSIBLY EXTEND DENSE FOG
ADVISORY TO THE SOUTHWEST BUT THIS WILL NOT BE UNTIL THE SURFACE
LOW CURRENTLY OVER THE SOUTHWEST...SHIFTS FARTHER SOUTHEAST AND
NORTHERLY FLOW KICKS IN SPREADING THE STRATUS INTO THIS AREA. THUS
WILL JUST EXTEND CURRENT ADVISORY AND WE CAN CANCEL EARLY IF
NEEDED.
OTHERWISE ONLY MINOR CHANGES TO THE CURRENT GRIDS. UPDATED TEXT
PRODUCTS WILL BE OUT SHORTLY.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 330 PM CST SUN FEB 8 2015
HIGHLIGHTS OF THE SHORT TERM ARE FOG AND FREEZING DRIZZLE THIS
AFTERNOON INTO TONIGHT.
BASED ON WEBCAM TRENDS FROM 20 TO 21 UTC...ISSUED A DENSE FOG
ADVISORY FOR PORTIONS OF WESTERN NORTH DAKOTA ARCHING FROM
WILLIAMS AND MOUNTRAIL COUNTIES SOUTH THROUGH GRANT AND MORTON
COUNTIES THROUGH 00 UTC. UNCERTAINTY REMAINS AS TO IF THE WESTERN
EDGE OF THE STRATUS BANK WHERE THE DENSE FOG RESIDES WILL CONTINUE
TO SLOWLY ERODE THIS AFTERNOON...OR IF THE EASTWARD EROSION WILL
HALT WITH DECREASING INSOLATION. THUS...WILL ALLOW THE NEXT SHIFT
TO EVALUATE. ELSEWHERE ACROSS CENTRAL NORTH DAKOTA EAST OF HIGHWAY
83....DID ADD A MENTION OF PATCHY FREEZING DRIZZLE TO THE SLIGHT
CHANCE SNOW WITH A POTENTIAL LOSS OF ICE CRYSTALS IN THE COLUMN
THROUGH THE EVENING. HOWEVER...DO NOT EXPECT IMPACTS TO RISE TO
ADVISORY LEVEL. FOR MONDAY...THE SIMILAR SETUP CONTINUES OF HIGHS
IN THE SOUTHWEST BEING MUCH WARMER...NAMELY THE 40S WHERE SOME SUN
MAY BREAK OUT...TO THE TEENS ACROSS THE TURTLE MOUNTAINS UNDER A
BROAD STRATUS DECK.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 PM CST SUN FEB 8 2015
MAIN CONCERN FOR THE LONG TERM PERIOD WILL BE THE NEXT SYSTEM MOVING
IN MONDAY NIGHT THROUGH TUESDAY NIGHT BRINGING FREEZING RAIN AND
SNOW TO THE REGION.
MONDAY NIGHT THROUGH TUESDAY NIGHT: AN UPPER LEVEL SHORTWAVE TROUGH
MOVES INTO WESTERN NORTH DAKOTA LATE AFTERNOON MONDAY AND EXITS THE
REGION TO THE EAST LATE TUESDAY NIGHT.
MONDAY EVENING: A SURFACE LOW DEVELOPS IN THE LEE OF THE ROCKIES AND
BRINGS WARM AIR INTO THE REGION. PRECIPITATION WILL START OUT AS
LIGHT RAIN IN FAR SOUTHWESTERN NORTH DAKOTA WHERE TEMPERATURES
SHOULD BE IN THE 30S AND 40S...AND LIGHT FREEZING RAIN ELSEWHERE.
LATE MONDAY NIGHT: COLDER AIR WILL INTRUDE INTO NORTHERN NORTH
DAKOTA...AND FREEZING RAIN SHOULD CHANGEOVER TO ALL SNOW ALONG AND
NORTH OF A LINE FROM WILLISTON TO MINOT AND JAMESTOWN. FREEZING RAIN
SHOULD CONTINUE SOUTH AND WEST OF THIS LINE.
TUESDAY: A WINTRY MIX EXPECTED IN A BROAD AREA MAINLY ALONG THE
MISSOURI RIVER...WITH SNOW EXPECTED NORTH AND EAST...AND FREEZING
RAIN SOUTH AND WEST OF THE MISSOURI. COLD ADVECTION DURING THE DAY
TUESDAY SHOULD SEE A CHANGEOVER TO SNOW FROM NORTH TO SOUTH ACROSS
THE STATE.
TUESDAY NIGHT: PRECIPITATION IN THE FORM OF ALL SNOW EXCEPT DURING
THE EVENING IN THE FAR SOUTHWEST...WHERE A TRANSITION SHOULD OCCUR
DURING THE EVENING HOURS.
OVERALL: LIGHT TO MODERATE SNOWFALL ACCUMULATIONS ARE POSSIBLE
ACROSS NORTHERN NORTH DAKOTA AND THE TURTLE MOUNTAINS. THE CHANCE OF
ACCUMULATING ICE ACROSS MONDAY NIGHT INTO TUESDAY WILL BE GREATEST
ALONG AND SOUTH OF US HIGHWAYS 2 AND 52. SHOULD THE NEXT MODEL RUNS
DEPICT A DIFFERENT STORM TRACK WHICH WOULD TRANSLATE INTO A COLDER
(OR WARMER) SCENARIO FOR OUR AREA...THIS WILL AFFECT GREATLY THE
PRECIPITATION TYPE EXPECTED ACROSS THE REGION...AND HENCE THE
ANTICIPATED AMOUNTS OF FREEZING RAIN OR SNOW.
QUIET WEATHER RETURNS WEDNESDAY ON THE BACK SIDE OF THE DEPARTING
SYSTEM WITH COLDER CONDITIONS ACROSS MUCH OF THE AREA. A GRADUAL
WARMING TREND WILL DEVELOP LATE IN THE WEEK AS AN UPPER TROUGH OVER
THE WESTERN CONUS AMPLIFIES AND SLOWLY SHIFTS EASTWARD. ACTIVE
NORTHWEST FLOW PATTERN THEN RETURNS FOR THE WEEKEND BRINGING
PRECIPITATION CHANCES TO THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1140 PM CST SUN FEB 8 2015
LATEST HRRR/NUMERICAL GUIDANCE CONTINUE TO INDICATE LIFR-IFR
CEILINGS AND MVFR-IFR VISIBILITIES IN FOG FOR KISN...KDIK...KBIS AND
KMOT THROUGH MONDAY MORNING...WITH VISIBILITIES IMPROVING BUT IFR
CEILING INTO THE AFTERNOON AND POSSIBLY COMPLETELY THROUGH THE
FORECAST PERIOD OF 06 UTC TUESDAY. KJMS CEILINGS ARE EXPECTED TO
REMAIN MAINLY MVFR BUT COULD DROP TO IFR FOR A PERIOD LATE TONIGHT
INTO MONDAY MORNING WITH POSSIBLY SOME MVFR FOG. DEVELOPING LOW
PRESSURE WILL MOVE INTO EASTERN MONTANA BY 06 UTC TUESDAY. AHEAD OF
THE LOW...PRECIPITATION WILL SPREAD INTO WESTERN NORTH DAKOTA FROM
00-06 UTC TUESDAY. BROUGHT RAIN TO KDIK AND FZRA TO KISN AROUND 01
UTC. THEN FZRA TO KBIS AND FZRA AND -SN TO KMOT AROUND 04 UTC.
PRECIPITATION WILL CONTINUE BEYOND THE FORECAST PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CST /9 AM MST/ MONDAY FOR NDZ009-
010-017>020-031>034-040>045.
&&
$$
UPDATE...KS
SHORT TERM...AYD
LONG TERM...JV
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
919 PM EST TUE FEB 10 2015
.SYNOPSIS...
HIGH PRESSURE BUILDS IN TONIGHT. ARCTIC FRONTS CROSSES WEDNESDAY
NIGHT AND AGAIN ON SATURDAY....AND MAYBE EVEN AGAIN NEXT WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
900 PM UPDATE...NO SIGNIFICANT CHANGES MADE. DID ADJUST CLOUDS
TONIGHT BASED ON CURRENT SATELLITE.
PREVIOUS DISCUSSION...
CURRENT SATELLITE IMAGERY SHOWS THE AREA BLANKETED BY LLVL STRATUS
AIDED BY RESIDUAL MOISTURE FROM THE SFC LOW NOW PULLING AWAY FROM
THE MID-ATLANTIC COAST. SOME CLEARING IS BEING OBSERVED IN THE FAR
NW COUNTIES OF OUR CWA AS THE MOISTURE IS SLOWLY ERODED BY DRIER
AIR FROM THE WEST. THE RAP HAS THE BEST HANDLE ON THIS...BUT THATS
NOT SAYING MUCH. MOST GUIDANCE HAS BEEN TERRIBLE WITH RESPECT TO
THE CLEARING OF THE LOW CLOUDS. MOISTURE IS EXPECTED TO HOLD
LONGER IN THE MNTS...WHERE LOW CEILINGS WILL PERSIST UNTIL WED
MORNING.
RELATIVELY QUIET NIGHT ON TAP WITH CLOUD COVER CONTINUING TO ERODE
AS THE UPPER RIDGE SETTLES IN. TEMPERATURES WILL REMAIN ON THE
COOL SIDE TONIGHT AS WE DECOUPLE...BUT WAA BEGINS TO KICK FOR
DAYBREAK AND MIXING WILL BRING WEDS TEMPS BACK UP INTO THE 40S FOR
MOST LOCATIONS.
FOR AS LONG AS IT TOOK THE SW RIDGE TO BUILD IN AND DRY THINGS
OUT...IT UNFORTUNATELY WONT STAY LONG. THE FIRST IN A SERIES OF
UPPER LEVEL WAVES WILL ARRIVE EARLY WEDS AFTERNOON...BRINGING
MAINLY CLOUDS BACK TO THE AREA. AS THE UPPER LEVEL WAVE
ARRIVES...IT DEAMPLIFIES AND THE FLOW ALOFT BECOMES MORE ZONAL.
STILL...SOME WEAK MID-LEVEL CONVERGENCE EXISTS AHEAD OF THE FIRST
WAVE AND MODELS HAVE CONSISTENTLY INCLUDED QPF WITH LIGHT SHOWERS
WEDS EVENING. NOT SOLD ON THE IDEA...BUT WITH THIS FEATURE EVEN
RESOLVED IN THE COARSER SUITE OF MODELS...THOUGHT IS WAS PRUDENT
TO INTRODUCE SLIGHT CHC POPS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
ACTIVE AND COLD WEATHER PATTERN REMAINS IN THE SHORT TERM AS A
BARRAGE OF UPPER LEVEL WAVES WILL REINFORCE THE MEAN TROF IN THE
EAST. ANOTHER WEAK WAVE WILL PASS JUST NORTH OF THE FORECAST AREA
WEDS NIGHT AND AGAIN WILL DEAMPLIFY AS ON APPROACH. THIS
DEAMPLIFICATION IS DUE TO THE THIRD AND BY FAR MOST VIGOROUS WAVE
DROPPING IN QUICKLY BEHIND IT. EXPECT LIGHT RAIN CHANGING OVER TO
LIGHT SNOW FOR MAINLY NRN PORTIONS OF THE CWA THROUGH THE PRE-DAWN
HOURS THURS.
AROUND DAWN THURS...CONDITIONS WILL DETERIORATE VERY QUICKLY. AS
AN AMPLIFYING TROF DROPS THROUGH THE WRN GREAT LAKES AND TRIES TO
CLOSE OFF AT 500MB. THIS WILL SEND A A VIGOROUS WAVE THROUGH THE
FORECAST AREA...USHERING IN A COLD FRONT WITH A VASTLY DIFFERENT
AIR MASS BEHIND IT. TEMPERATURES WILL FOLLOW A NON-DIURNAL CURVE
WITH THURS HIGHS MORE THAN LIKELY REALIZED NEAR SUNRISE.
ORIENTED ALONG THE COLD FRONT...SNOW SHOWERS WILL OVERTAKE THE
REGION FROM W TO E QUICKLY DURING THE DAYLIGHT HOURS THURS. BEHIND
THE COLD FRONT...850MB TEMPS WILL DROP SHARPLY INTO THE -10 TO
-15C RANGE ALLOWING CRYSTAL GROWTH TO BE MAXIMIZED. WITH LAPSE
RATES STEEPENING...CONVECTIVE SNOW SQUALLS WILL PERSIST THROUGH THURS
EVENING. THE BTV SNOW SQUALL PARAMETER DRIVEN BY THE 12Z NAM DATA
SHOWS A BULLSEYE OF GREATER THAN 4 FOR MUCH OF THE AFTERNOON
THURS...FURTHER DIAGNOSING A PRIME SET UP FOR SNOW SQUALLS TO
EXIST.
MOISTURE IS DRIVEN INTO THE MOUNTAINS THROUGH THURS NIGHT...AND
SNOW SHOWERS SHOULD PERSIST THERE THROUGH MIDNIGHT THURS.
ELSEWHERE...THE MOISTURE QUICKLY DRIES UP...BUT THE AIRMASS IS
COLD ENOUGH THAT LIGHT SNOW SHOWERS OR FLURRIES COULD PERSIST
THROUGH LATE THURS EVENING.
EXPECT MOUNTAINOUS LOCATIONS TO BE IN THE SINGLE DIGITS TO BELOW
ZERO...AS WELL AS SINGLE DIGITS IN SOUTHEAST OHIO FRIDAY MORNING.
ADDING TO THIS IS THE STRONG...GUSTY WINDS THAT WILL DRIVE WIND
CHILLS TO NEAR 0 ACROSS THE LOWLANDS AND WELL BELOW 0 IN THE
MOUNTAINS. STILL EXPECTING WIND CHILL ADVISORY CRITERIA TO BE MET
ACROSS MUCH OF THE MOUNTAINOUS COUNTIES AND PARTS OF NORTHERN WV.
WILL CONTINUE TO HIGHLIGHT IN THE HWO.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MEAN TROF PERSISTS ACROSS THE ERN CONUS THROUGH THE EXTENDED
PERIOD KEEPING A PROLONGED COLD AND DISTURBED WEATHER PATTERN.
BRIEF SFC HIGH FRI WILL BE FOLLOWED QUICKLY BY YET ANOTHER VERY
STRONG CLOSED UPPER LOW THIS WEEKEND. THIS WILL ONCE AGAIN
REINFORCE THE COLD AIR...BRINGING THE COLDEST TEMPERATURES OF THE
WEEK TO OUR AREA. MORE LIGHT SNOW IS EXPECTED THROUGH THE
WEEKEND...BUT THE MAIN STORY LINE WILL BE THE COLD TEMPERATURES.
NEXT WEEK BEGINS WITH A VERY BRIEF SPELL OF ZONAL FLOW ALOFT AND
TEMPERATURE MODERATION BEFORE YET ANOTHER INTRUSION OF ARCTIC AIR.
MAINLY FOLLOW WPC FOR WEATHER VARIABLES IN THE EXTENDED...WITH
CONSIDERABLE MODEL AGREEMENT BETWEEN THE GFS/ECMWF.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
CLEAR SKIES HAVE BEEN TRYING TO MOVE INTO WESTERN CWA EARLY THIS
EVENING...BUT HAVING A FAIRLY HARD TIME. DO HAVE VFR IN THE
WESTERN WV LOWLANDS AND OHIO RIVER VALLEY. GENERALLY STUCK IN IFR
IN THE MOUNTAINS. FAIRLY LOW CONFIDENCE IN THE PROGRESSION OF THIS
CLEARING OVERNIGHT...AS MODELS TRY TO INDICATE IT FILLING BACK
IN...WITH MVFR CIG/VIS ACROSS THE LOWLANDS AND IFR IN THE
MOUNTAINS. STUCK FAIRLY CLOSE TO LAMP GUIDANCE WITH MVFR FROM CKB-
CRW AND WEST. THEN HAVE DENSE FOG FORMING IN THE MOUNTAINS. ANY
LINGERING IFR/MVFR WILL DISSIPATE THROUGH MID MORNING TOMORROW AS
CIRRUS BEGIN MOVING IN FROM THE WEST.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z THURSDAY...
FORECAST CONFIDENCE: LOW.
ALTERNATE SCENARIO: TIMING OF IMPROVEMENT MAY VARY. MVFR CIGS MAY
NOT MATERIALIZE TONIGHT. IFR FOG IN THE MOUNTAINS OVERNIGHT
TONIGHT MAY NOT HAPPEN EITHER.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE WED
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EST 1HRLY 19 20 21 22 23 00 01 02 03 04 05 06
CRW CONSISTENCY M M M M M M H M M M M M
HTS CONSISTENCY H H M M M M M M M M H H
BKW CONSISTENCY L L L L L L L L L L L L
EKN CONSISTENCY M M M M M M L L L L L L
PKB CONSISTENCY H H M M M M M M M M H H
CKB CONSISTENCY H H M H H H H H H H H H
AFTER 00Z THURSDAY...
IFR IN THE MOUNTAINOUS COUNTIES IN SNOW SHOWERS ON THURSDAY AND
AGAIN SATURDAY AFTERNOON...EACH IN THE WAKE OF ARCTIC FRONTS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TAX
NEAR TERM...TAX/MZ
SHORT TERM...TAX
LONG TERM...TAX
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
642 PM EST TUE FEB 10 2015
.SYNOPSIS...
HIGH PRESSURE BUILDS IN TONIGHT. ARCTIC FRONTS CROSSES WEDNESDAY
NIGHT AND AGAIN ON SATURDAY....AND MAYBE EVEN AGAIN NEXT WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
640 PM UPDATE...TWEAKED HOURLY GRIDS BASED ON CURRENT OBS AND
TRENDS...BUT NO SIGNIFICANT CHANGES MADE.
PREVIOUS DISCUSSION...
CURRENT SATELLITE IMAGERY SHOWS THE AREA BLANKETED BY LLVL STRATUS
AIDED BY RESIDUAL MOISTURE FROM THE SFC LOW NOW PULLING AWAY FROM
THE MID-ATLANTIC COAST. SOME CLEARING IS BEING OBSERVED IN THE FAR
NW COUNTIES OF OUR CWA AS THE MOISTURE IS SLOWLY ERODED BY DRIER
AIR FROM THE WEST. THE RAP HAS THE BEST HANDLE ON THIS...BUT THATS
NOT SAYING MUCH. MOST GUIDANCE HAS BEEN TERRIBLE WITH RESPECT TO
THE CLEARING OF THE LOW CLOUDS. MOISTURE IS EXPECTED TO HOLD
LONGER IN THE MNTS...WHERE LOW CEILINGS WILL PERSIST UNTIL WED
MORNING.
RELATIVELY QUIET NIGHT ON TAP WITH CLOUD COVER CONTINUING TO ERODE
AS THE UPPER RIDGE SETTLES IN. TEMPERATURES WILL REMAIN ON THE
COOL SIDE TONIGHT AS WE DECOUPLE...BUT WAA BEGINS TO KICK FOR
DAYBREAK AND MIXING WILL BRING WEDS TEMPS BACK UP INTO THE 40S FOR
MOST LOCATIONS.
FOR AS LONG AS IT TOOK THE SW RIDGE TO BUILD IN AND DRY THINGS
OUT...IT UNFORTUNATELY WONT STAY LONG. THE FIRST IN A SERIES OF
UPPER LEVEL WAVES WILL ARRIVE EARLY WEDS AFTERNOON...BRINGING
MAINLY CLOUDS BACK TO THE AREA. AS THE UPPER LEVEL WAVE
ARRIVES...IT DEAMPLIFIES AND THE FLOW ALOFT BECOMES MORE ZONAL.
STILL...SOME WEAK MID-LEVEL CONVERGENCE EXISTS AHEAD OF THE FIRST
WAVE AND MODELS HAVE CONSISTENTLY INCLUDED QPF WITH LIGHT SHOWERS
WEDS EVENING. NOT SOLD ON THE IDEA...BUT WITH THIS FEATURE EVEN
RESOLVED IN THE COARSER SUITE OF MODELS...THOUGHT IS WAS PRUDENT
TO INTRODUCE SLIGHT CHC POPS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
ACTIVE AND COLD WEATHER PATTERN REMAINS IN THE SHORT TERM AS A
BARRAGE OF UPPER LEVEL WAVES WILL REINFORCE THE MEAN TROF IN THE
EAST. ANOTHER WEAK WAVE WILL PASS JUST NORTH OF THE FORECAST AREA
WEDS NIGHT AND AGAIN WILL DEAMPLIFY AS ON APPROACH. THIS
DEAMPLIFICATION IS DUE TO THE THIRD AND BY FAR MOST VIGOROUS WAVE
DROPPING IN QUICKLY BEHIND IT. EXPECT LIGHT RAIN CHANGING OVER TO
LIGHT SNOW FOR MAINLY NRN PORTIONS OF THE CWA THROUGH THE PRE-DAWN
HOURS THURS.
AROUND DAWN THURS...CONDITIONS WILL DETERIORATE VERY QUICKLY. AS
AN AMPLIFYING TROF DROPS THROUGH THE WRN GREAT LAKES AND TRIES TO
CLOSE OFF AT 500MB. THIS WILL SEND A A VIGOROUS WAVE THROUGH THE
FORECAST AREA...USHERING IN A COLD FRONT WITH A VASTLY DIFFERENT
AIR MASS BEHIND IT. TEMPERATURES WILL FOLLOW A NON-DIURNAL CURVE
WITH THURS HIGHS MORE THAN LIKELY REALIZED NEAR SUNRISE.
ORIENTED ALONG THE COLD FRONT...SNOW SHOWERS WILL OVERTAKE THE
REGION FROM W TO E QUICKLY DURING THE DAYLIGHT HOURS THURS. BEHIND
THE COLD FRONT...850MB TEMPS WILL DROP SHARPLY INTO THE -10 TO
-15C RANGE ALLOWING CRYSTAL GROWTH TO BE MAXIMIZED. WITH LAPSE
RATES STEEPENING...CONVECTIVE SNOW SQUALLS WILL PERSIST THROUGH THURS
EVENING. THE BTV SNOW SQUALL PARAMETER DRIVEN BY THE 12Z NAM DATA
SHOWS A BULLSEYE OF GREATER THAN 4 FOR MUCH OF THE AFTERNOON
THURS...FURTHER DIAGNOSING A PRIME SET UP FOR SNOW SQUALLS TO
EXIST.
MOISTURE IS DRIVEN INTO THE MOUNTAINS THROUGH THURS NIGHT...AND
SNOW SHOWERS SHOULD PERSIST THERE THROUGH MIDNIGHT THURS.
ELSEWHERE...THE MOISTURE QUICKLY DRIES UP...BUT THE AIRMASS IS
COLD ENOUGH THAT LIGHT SNOW SHOWERS OR FLURRIES COULD PERSIST
THROUGH LATE THURS EVENING.
EXPECT MOUNTAINOUS LOCATIONS TO BE IN THE SINGLE DIGITS TO BELOW
ZERO...AS WELL AS SINGLE DIGITS IN SOUTHEAST OHIO FRIDAY MORNING.
ADDING TO THIS IS THE STRONG...GUSTY WINDS THAT WILL DRIVE WIND
CHILLS TO NEAR 0 ACROSS THE LOWLANDS AND WELL BELOW 0 IN THE
MOUNTAINS. STILL EXPECTING WIND CHILL ADVISORY CRITERIA TO BE MET
ACROSS MUCH OF THE MOUNTAINOUS COUNTIES AND PARTS OF NORTHERN WV.
WILL CONTINUE TO HIGHLIGHT IN THE HWO.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MEAN TROF PERSISTS ACROSS THE ERN CONUS THROUGH THE EXTENDED
PERIOD KEEPING A PROLONGED COLD AND DISTURBED WEATHER PATTERN.
BRIEF SFC HIGH FRI WILL BE FOLLOWED QUICKLY BY YET ANOTHER VERY
STRONG CLOSED UPPER LOW THIS WEEKEND. THIS WILL ONCE AGAIN
REINFORCE THE COLD AIR...BRINGING THE COLDEST TEMPERATURES OF THE
WEEK TO OUR AREA. MORE LIGHT SNOW IS EXPECTED THROUGH THE
WEEKEND...BUT THE MAIN STORY LINE WILL BE THE COLD TEMPERATURES.
NEXT WEEK BEGINS WITH A VERY BRIEF SPELL OF ZONAL FLOW ALOFT AND
TEMPERATURE MODERATION BEFORE YET ANOTHER INTRUSION OF ARCTIC AIR.
MAINLY FOLLOW WPC FOR WEATHER VARIABLES IN THE EXTENDED...WITH
CONSIDERABLE MODEL AGREEMENT BETWEEN THE GFS/ECMWF.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
CLEAR SKIES HAVE BEEN TRYING TO MOVE INTO WESTERN CWA EARLY THIS
EVENING...BUT HAVING A FAIRLY HARD TIME. DO HAVE VFR IN THE
WESTERN WV LOWLANDS AND OHIO RIVER VALLEY. GENERALLY STUCK IN IFR
IN THE MOUNTAINS. FAIRLY LOW CONFIDENCE IN THE PROGRESSION OF THIS
CLEARING OVERNIGHT...AS MODELS TRY TO INDICATE IT FILLING BACK
IN...WITH MVFR CIG/VIS ACROSS THE LOWLANDS AND IFR IN THE
MOUNTAINS. STUCK FAIRLY CLOSE TO LAMP GUIDANCE WITH MVFR FROM CKB-
CRW AND WEST. THEN HAVE DENSE FOG FORMING IN THE MOUNTAINS. ANY
LINGERING IFR/MVFR WILL DISSIPATE THROUGH MID MORNING TOMORROW AS
CIRRUS BEGIN MOVING IN FROM THE WEST.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z THURSDAY...
FORECAST CONFIDENCE: LOW.
ALTERNATE SCENARIO: TIMING OF IMPROVEMENT MAY VARY. MVFR CIGS MAY
NOT MATERIALIZE TONIGHT. IFR FOG IN THE MOUNTAINS OVERNIGHT
TONIGHT MAY NOT HAPPEN EITHER.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE WED
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EST 1HRLY 19 20 21 22 23 00 01 02 03 04 05 06
CRW CONSISTENCY M M M M M M H M M M M M
HTS CONSISTENCY H H M M M M M M M M H H
BKW CONSISTENCY L L L L L L L L L L L L
EKN CONSISTENCY M M M M M M L L L L L L
PKB CONSISTENCY H H M M M M M M M M H H
CKB CONSISTENCY H H M H H H H H H H H H
AFTER 00Z THURSDAY...
IFR IN THE MOUNTAINOUS COUNTIES IN SNOW SHOWERS ON THURSDAY AND
AGAIN SATURDAY AFTERNOON...EACH IN THE WAKE OF ARCTIC FRONTS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TAX
NEAR TERM...TAX/MZ
SHORT TERM...TAX
LONG TERM...TAX
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1026 PM EST TUE FEB 10 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL BUILD INTO PENNSYLVANIA OVERNIGHT
AND WEDNESDAY. A PAIR OF POTENT SHORTWAVES AND ASSOCIATED CLIPPERS
WILL CARVE OUT A DEEP UPPER LEVEL TROUGH OVER THE NORTHEAST CONUS
LATE THIS WEEK THROUGH EARLY NEXT WEEK. THESE SYSTEMS WILL BRING
BITTERLY COLD AIR BACK INTO CENTRAL PENNSYLVANIA WHICH WILL LAST
THROUGH THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
10 PM UPDATE...
CLOUDS CLOUDS AND MORE CLOUDS. THE NORTHERN TIPS OF THE FINGER
LAKES ARE STARTING TO APPEAR...SO THERE IS SOME HOPE FOR CLEARING.
BUT HAVE KEPT ON WITH THE PREV IDEA OF CLOUDS HOLDING ON PRETTY
LONG INTO THE NIGHT...ESP IN THE WESTERN MTNS. HAVE ADDED A DEG OR
TWO TO MINS IN THOSE CLOUDIER AREAS AND KNOCKED ONE OR TWO OFF IN
THE SE.
740 PM UPDATE...
CLOUDS HANGING TOUGH AND SHOWING NO SIGNS OF GOING AWAY. IN
FACT...THE WEAK NRLY FLOW IS ONLY REINFORCING THEM. WHILE HIGH
PRESSURE IS SLATED TO BUILD IN...CANNOT GO WITH TOO MUCH CLEARING
AS THE SUBSIDENCE INVERSION HAS NOT STARTED TO SHOW UP.
PREV...
AS A RIDGE OF HIGH PRESSURE REMAINS OVER THE REGION...LARGE SCALE
SUBSIDENCE DOMINATES THE FORECAST THROUGH TOMORROW. THE MAIN
CONCERN WILL BE HOW MUCH CLEARING IS OBSERVED. CURRENT HRRR AND
MODEL SOUNDINGS SUGGEST STRATOCU WILL CONTINUE THROUGH THE REST OF
THE AFTERNOON AND INTO THE EVENING. THE WINDS ARE COMING FROM THE
NORTH TO NORTHEAST...AND AS THEY SHIFT TO THE EAST...THERE WILL BE
SOME DRY AIR ADVECTION. THE THICKEST CLOUDS CONTINUE TO BE OVER
THE CENTRAL AND NW MTNS...ESPECIALLY THE LAURELS...WHERE LOW
STRATOCU...UPSLOPE FLOW...AND LOW LEVEL MOISTURE FROM YESTERDAYS
PRECIPITATION AND CORRESPONDING MELTED SNOWPACK HAVE ALLOWED FOR
REDUCED VISIBILITIES AS WELL. THESE CONDITIONS WILL SLOWLY WEAKEN
AS THE NIGHT CONTINUES AS THE RIDGE FLATTENS...AND MORE ZONAL
UPPER LEVEL FLOW MOVES OVER THE REGION FOR TOMORROW.
FAIR WX EXPECTED TONIGHT AS THE DRY AIR MOVES INTO THE
REGION...CLOUDS WILL SLOWLY BREAK UP AND DISSIPATE. IF THE SFC
DECOUPLES OVERNIGHT...THERE IS A CHANCE FOR SOME LOW CLOUDS TO
REDEVELOP...MAINLY OVER THE CENTRAL AND NORTHWEST MOUNTAINS.
LIGHT WINDS...CLEARING SKIES AND SNOW COVER SHOULD ALLOW TEMPS TO
FALL SEVERAL DEG BLW SEASONAL NORMS WITH TEMPERATURES RANGING FROM
THE LOW SINGLE DIGITS IN THE NORTHEAST...TO THE MID TO UPPER TEENS
ELSEWHERE.
OVERALL FAIR WEATHER WILL CONTINUE THROUGH TOMORROW AS A POTENT
SHORTWAVE WILL BE DIVING SOUTHEASTWARD INTO THE GREAT LAKES REGION
LATE WEDNESDAY. THE WINDS SHIFT TO THE NORTHWEST OUT AHEAD OF THIS
TROUGH. THIS SYSTEM WILL BRING AN INCREASE CHANCE FOR
PRECIPITATION THROUGH THE NW MTNS LATE WEDNESDAY.
PARTIAL SUNSHINE AND A BRIEF SHOT OF WAA IN ADVANCE OF CLIPPER
SHOULD HELP TEMPS RECOVER TO NEAR NORMAL WED AFTN WITH MAXES
MOSTLY IN THE LOW TO MID 30S.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
THE WAVE TRAIN OF ALBERTA CLIPPERS BEGINS WEDNESDAY NIGHT AND
THURSDAY. NOT MANY SIGNIFICANT CHANGES HAVE OCCURRED IN THE MODEL
CONSENSUS TRACK AND INTENSITY OF THESE FEATURES OVER THE PAST 24
HOURS...SO MINOR MODIFICATIONS TO POPS...TEMPS..AND WIND/WIND
CHILLS HAVE BEEN MADE WITH THIS ROUND OF GRIDDED DATA.
AFTER A BRIEF...SEVERAL-HOUR PERIOD OF WARM ADVECTION CLOUDS AND
A FEW AREAS OF LIGHT SNOW/SNOW SHOWERS ACROSS NRN AND WRN PENN
LATE WED/WED NIGHT...THE FIRST CLIPPER IS STILL TIMED TO PUSH THE
LEADING EDGE OF AN ARCTIC AIRMASS INTO THE COMMONWEALTH LATE WED
NIGHT AND THURSDAY MORNING.
TEMPS STARTING OUT IN THE 20S THURSDAY MORNING WILL BE FOLLOWED
BY GRADUALLY FALLING TEMPS ALL DAY /AT LEAST ACROSS CENTRAL AND
NWRN PENN/ WITH NUMEROUS SNOW SHOWERS FLYING ACROSS THE
ALLEGHENIES...AND FLURRIES/SCATTERED SNOW SHOWERS OCCURRING
THROUGHOUT THE CENTRAL RIDGE AND VALLEY REGION.
AN ACCUMULATION OF 1-3 INCHES APPEARS POSSIBLE ACROSS THE LAURELS
AND NW MTNS...WHILE JUST A COATING TO ONE HALF OF AN INCH IS
EXPECTED ELSEWHERE.
AS THE LEADING EDGE OF THE VERY COLD MID LEVEL AIR PUSHES SE
ACROSS THE STATE DURING PRIME HEATING OF THE LATE MORNING AND
AFTERNOON HOURS...850-500 MB LAPSE RATES WILL STEEPEN TO AROUND
6.5C/KM WHICH WILL SUPPORT SOME BRIEF...HEAVY SNOW SHOWERS/SQUALLS.
SHOULD THIS SCENARIO BECOME MORE EVIDENT...POPS ACROSS THE SE HALF
OF THE CWA WILL NEED TO BE INCREASED FOR ANTICIPATED LIGHT ACCUMS
OF SNOW.
NW WINDS INCREASING TO 10-18 KTS WITH GUSTS OCNLY TO 25-30 KTS IN
THE AFTERNOON WILL USHER IN BITTERLY COLD TEMPS AND WIND CHILLS.
WIDESPREAD WIND CHILL ADVISORY VALUES LOOK PROBABLY THROUGHOUT THE
RIDGE AND VALLEY REGION LATE THURSDAY NIGHT/EARLY FRIDAY...WITH
WARNING CRITERIA /LESS THAN -25C/ POSSIBLE ACROSS PORTIONS OF THE
NORTH AND WEST. THE SUSQ VALLEY MAY ESCAPE THE BRUTALLY COLD WIND
CHILLS WITH APPARENT TEMPS OF -10 TO -14F.
LATER SHIFTS - OVERNIGHT TONIGHT OR WEDNESDAY WILL LIKELY BE
POSTING WIND CHILL WATCH/OR ADVISORY FOR THE AFOREMENTIONED
LOCATIONS.
THE ALLEGHENY PLATEAU. A BITING WIND WILL LIKELY ACCOMPANY THE
SUB- ZERO TEMPS...DUE TO TIGHT PRES GRADIENT WEST OF RAPIDLY
DEVELOPING COASTAL STORM EAST OF NEW ENG.
FRIDAY WILL LIKELY BE ONE OF THE COLDEST DAYS OF THE WINTER SEASON
SO FAR WITH ANOMALOUSLY GEFS MEAN 850 MB TEMPS STILL FCST TO
PLUMMET TO ARND -20C OVER THE AREA. HIGH TEMPS FRIDAY PROJECTED
TO VARY VARY FROM JUST THE SINGLE DIGITS ACROSS THE NORTHERN
MTNS...TO THE MID AND UPPER TEENS ACROSS THE SOUTHERN VALLEYS.
AN EXTENSIVE RIDGE OF HIGH PRESSURE BUILDS EAST ACROSS THE FRIDAY
INTO EARLY FRIDAY NIGHT WITH SLOWLY DECREASING NW WINDS AND
PARTLY TO MOSTLY SUNNY SKIES ACROSS THE CENTRAL AND SE ZONES. THE
NW MTNS MAY HAVE A TOUGH TIME BREAKING UP THE SHALLOW STRATO CU
THOUGH...SO HEDGED TOWARD MSTLY CLOUDY ACROSS THE NRN AND WRN MTNS
/BUT WITH LITTLE MORE THAN SOME FLURRIES/.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE NEXT CAR IN THE CLIPPER TRAIN RIDES ACROSS THE CWA LATE
FRIDAY NIGHT AND SATURDAY...ACCOMPANIED BY NUMEROUS SNOW
SHOWERS...OR EVEN A FEW PERIODS OF STEADY SNOW INTO SATURDAY
EVENING AS SOME MODEL GUIDANCE INDICATES A CLOSED MID/UPPER LOW
CENTER FORMING OVER CENTRAL/ERN PENN BEFORE SCOOTING QUICKLY EAST
OFF THE MID ATLANTIC COAST. AIR BEHIND THIS SYSTEM WILL BE EVEN A
FEW-SVRL DEG F COLDER THAN THE INITIAL LATE WEEK CLIPPER. TEMPS
SHOULD STEADILY FALL /FROM THEIR ALREADY BELOW NORMAL VALUES/
SATURDAY AFTERNOON/EVENING...WITH A FEW SQUALLS EMBEDDED IN THE
LARGER SCALE AREAS OF LIGHTER SNOW.
AS THE SFC LOW RAPIDLY DEEPENS JUST OFF THE MID ATLANTIC/SRN NEW
ENGLAND COAST SAT NIGHT/SUNDAY...NW WINDS WILL INCREASE TO
SUSTAINED SPEEDS IN THE TEENS-LOW 20 KT RANGE WITH GUSTS UP TO 30
KTS...SIMILAR OR COLDER WIND CHILLS /THAN THURSDAY NIGHT`S ARE
EXPECTED BY VERY EARLY SUNDAY/.
A TRUE TASTE OF THE ARCTIC WILL BE PLATED UP FOR RESIDENTS OF
PENN SUNDAY...WITH MEAN GEFS 850 MB TEMPS BOTTOMING OUT IN THE
LOW-MID -20C RANGE - RESULTING IN SFC MAX TEMPS POSSIBLY STAYING
JUST BELOW ZERO ACROSS THE NRN MTNS...AND ONLY REACHING THE UPPER
SINGLE DIGITS TO MID TEENS AT BEST ACROSS THE CENTRAL AND SRN
PORTIONS OF THE STATE.
GRADUAL CLEARING FOR SUNDAY NIGHT/MONDAY AS A LARGE AREA OF HIGH
PRESSURE SETTLES SE ACROSS THE STATE. SHOULD THE WIND DIMINISH AND
SKIES CLEAR OUT QUICK ENOUGH...WIDESPREAD SUB-ZERO TEMPS ARE WOULD
BECOME LIKELY...WITH EVEN SOME RECORD MINS FOR THE DATE POSSIBLE.
FOR A QUICK EXAMPLE...WILLIAMSPORT`S LOW FOR FEB 16TH IS -5F SET
OVER A CENTURY AGO IN 1905...AND OUR FCST LOW THERE NEXT TUESDAY
MORNING IS IS -3F. GEFS MIN TEMP RANGE FOR KITP ON FEB 16TH IS
BETWEEN -3F AND -14F...SO I/M BEING OPTIMISTICALLY WARM- HEARTED
WITH THAT FCST LOW RIGHT AFTER V-DAY.
THE THIRD DIGGING SHORTWAVE /POSSIBLE CABOOSE/ TUESDAY...MAY HELP
TO BRIEFLY CARVE OUT THE MEAN ERN U.S. A LITTLE FURTHER TO THE
WEST /WHILE TEAMING UP WITH SOME SRN STREAM ENERGY/ ALLOWING FOR
SOME GOMEX MOISTURE TO BE PICKED UP BY THE SYSTEM BEFORE IT HEADS
EAST- NORTHEAST TWD THE VA/MID ATLANTIC COAST. FOR NOW...AND AT
THIS TIME RANGE WILL GO WITH ABOVE CLIMO POPS ACROSS THE CENTRAL
AND EAST FOR CHC OF LIGHT SNOW OR SNOW SHOWERS /DEPENDING ON
WHETHER WE SEE A DOMINANT NRN STREAM CLIPPER...OR PHASING NRN AND
SRN STREAM FEATURES/. TEMPS MONDAY AND TUESDAY WILL SLOWLY REBOUND
BUT LIKELY STAY SEVERAL DEG F BELOW NORMAL.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
MINOR CHANGES MADE TO THE 03Z TAF PACKAGE.
EARLIER DISCUSSION BELOW.
GIVEN STRONG INVERSION IN PLACE AND TIME OF DAY...DID ADJUST
00Z TAF PACKAGE TO HOLD ONTO LOWER CLDS UNTIL LATE WED MORNING.
THIS MAINLY IN SPOTS WHERE THE CLOUDS ARE NOW. WAS BETTER IN THE
LOCAL AREA AT LUNCH TIME TODAY.
STILL EXPECTING A DECENT AFTERNOON FOR MOST IF NOT ALL THE
AREA ON WED AFT.
CONDITIONS WILL DETERIORATE AFT 00Z THU AS ANOTHER TROUGH DROPS
THROUGH THE GREAT LAKES AND THROUGH PENNSYLVANIA WEDNESDAY NIGHT
INTO THURSDAY.
OUTLOOK...
WED NGT-THU...MVFR/IFR IN -SN. GUSTY NW WINDS THU NIGHT INTO
EARLY FRI BEHIND FROPA.
FRI...MVFR/IFR WITH -SHSN WEST.
SAT...MVFR/IFR WITH -SN.
SUN...MVFR/IFR WEST IN -SHSN. VFR ACROSS THE EAST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...LAMBERT
LONG TERM...FITZGERALD/LAMBERT
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1003 PM EST TUE FEB 10 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL BUILD INTO PENNSYLVANIA OVERNIGHT
AND WEDNESDAY. A PAIR OF POTENT SHORTWAVES AND ASSOCIATED CLIPPERS
WILL CARVE OUT A DEEP UPPER LEVEL TROUGH OVER THE NORTHEAST CONUS
LATE THIS WEEK THROUGH EARLY NEXT WEEK. THESE SYSTEMS WILL BRING
BITTERLY COLD AIR BACK INTO CENTRAL PENNSYLVANIA WHICH WILL LAST
THROUGH THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
10 PM UPDATE...
CLOUDS CLOUDS AND MORE CLOUDS. THE NORTHERN TIPS OF THE FINGER
LAKES ARE STARTING TO APPEAR...SO THERE IS SOME HOPE FOR CLEARING.
BUT HAVE KEPT ON WITH THE PREV IDEA OF CLOUDS HOLDING ON PRETTY
LONG INTO THE NIGHT...ESP IN THE WESTERN MTNS. HAVE ADDED A DEG OR
TWO TO MINS IN THOSE CLOUDIER AREAS AND KNOCKED ONE OR TWO OFF IN
THE SE.
740 PM UPDATE...
CLOUDS HANGING TOUGH AND SHOWING NO SIGNS OF GOING AWAY. IN
FACT...THE WEAK NRLY FLOW IS ONLY REINFORCING THEM. WHILE HIGH
PRESSURE IS SLATED TO BUILD IN...CANNOT GO WITH TOO MUCH CLEARING
AS THE SUBSIDENCE INVERSION HAS NOT STARTED TO SHOW UP.
PREV...
AS A RIDGE OF HIGH PRESSURE REMAINS OVER THE REGION...LARGE SCALE
SUBSIDENCE DOMINATES THE FORECAST THROUGH TOMORROW. THE MAIN
CONCERN WILL BE HOW MUCH CLEARING IS OBSERVED. CURRENT HRRR AND
MODEL SOUNDINGS SUGGEST STRATOCU WILL CONTINUE THROUGH THE REST OF
THE AFTERNOON AND INTO THE EVENING. THE WINDS ARE COMING FROM THE
NORTH TO NORTHEAST...AND AS THEY SHIFT TO THE EAST...THERE WILL BE
SOME DRY AIR ADVECTION. THE THICKEST CLOUDS CONTINUE TO BE OVER
THE CENTRAL AND NW MTNS...ESPECIALLY THE LAURELS...WHERE LOW
STRATOCU...UPSLOPE FLOW...AND LOW LEVEL MOISTURE FROM YESTERDAYS
PRECIPITATION AND CORRESPONDING MELTED SNOWPACK HAVE ALLOWED FOR
REDUCED VISIBILITIES AS WELL. THESE CONDITIONS WILL SLOWLY WEAKEN
AS THE NIGHT CONTINUES AS THE RIDGE FLATTENS...AND MORE ZONAL
UPPER LEVEL FLOW MOVES OVER THE REGION FOR TOMORROW.
FAIR WX EXPECTED TONIGHT AS THE DRY AIR MOVES INTO THE
REGION...CLOUDS WILL SLOWLY BREAK UP AND DISSIPATE. IF THE SFC
DECOUPLES OVERNIGHT...THERE IS A CHANCE FOR SOME LOW CLOUDS TO
REDEVELOP...MAINLY OVER THE CENTRAL AND NORTHWEST MOUNTAINS.
LIGHT WINDS...CLEARING SKIES AND SNOW COVER SHOULD ALLOW TEMPS TO
FALL SEVERAL DEG BLW SEASONAL NORMS WITH TEMPERATURES RANGING FROM
THE LOW SINGLE DIGITS IN THE NORTHEAST...TO THE MID TO UPPER TEENS
ELSEWHERE.
OVERALL FAIR WEATHER WILL CONTINUE THROUGH TOMORROW AS A POTENT
SHORTWAVE WILL BE DIVING SOUTHEASTWARD INTO THE GREAT LAKES REGION
LATE WEDNESDAY. THE WINDS SHIFT TO THE NORTHWEST OUT AHEAD OF THIS
TROUGH. THIS SYSTEM WILL BRING AN INCREASE CHANCE FOR
PRECIPITATION THROUGH THE NW MTNS LATE WEDNESDAY.
PARTIAL SUNSHINE AND A BRIEF SHOT OF WAA IN ADVANCE OF CLIPPER
SHOULD HELP TEMPS RECOVER TO NEAR NORMAL WED AFTN WITH MAXES
MOSTLY IN THE LOW TO MID 30S.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
THE WAVE TRAIN OF ALBERTA CLIPPERS BEGINS WEDNESDAY NIGHT AND
THURSDAY. NOT MANY SIGNIFICANT CHANGES HAVE OCCURRED IN THE MODEL
CONSENSUS TRACK AND INTENSITY OF THESE FEATURES OVER THE PAST 24
HOURS...SO MINOR MODIFICATIONS TO POPS...TEMPS..AND WIND/WIND
CHILLS HAVE BEEN MADE WITH THIS ROUND OF GRIDDED DATA.
AFTER A BRIEF...SEVERAL-HOUR PERIOD OF WARM ADVECTION CLOUDS AND
A FEW AREAS OF LIGHT SNOW/SNOW SHOWERS ACROSS NRN AND WRN PENN
LATE WED/WED NIGHT...THE FIRST CLIPPER IS STILL TIMED TO PUSH THE
LEADING EDGE OF AN ARCTIC AIRMASS INTO THE COMMONWEALTH LATE WED
NIGHT AND THURSDAY MORNING.
TEMPS STARTING OUT IN THE 20S THURSDAY MORNING WILL BE FOLLOWED
BY GRADUALLY FALLING TEMPS ALL DAY /AT LEAST ACROSS CENTRAL AND
NWRN PENN/ WITH NUMEROUS SNOW SHOWERS FLYING ACROSS THE
ALLEGHENIES...AND FLURRIES/SCATTERED SNOW SHOWERS OCCURRING
THROUGHOUT THE CENTRAL RIDGE AND VALLEY REGION.
AN ACCUMULATION OF 1-3 INCHES APPEARS POSSIBLE ACROSS THE LAURELS
AND NW MTNS...WHILE JUST A COATING TO ONE HALF OF AN INCH IS
EXPECTED ELSEWHERE.
AS THE LEADING EDGE OF THE VERY COLD MID LEVEL AIR PUSHES SE
ACROSS THE STATE DURING PRIME HEATING OF THE LATE MORNING AND
AFTERNOON HOURS...850-500 MB LAPSE RATES WILL STEEPEN TO AROUND
6.5C/KM WHICH WILL SUPPORT SOME BRIEF...HEAVY SNOW SHOWERS/SQUALLS.
SHOULD THIS SCENARIO BECOME MORE EVIDENT...POPS ACROSS THE SE HALF
OF THE CWA WILL NEED TO BE INCREASED FOR ANTICIPATED LIGHT ACCUMS
OF SNOW.
NW WINDS INCREASING TO 10-18 KTS WITH GUSTS OCNLY TO 25-30 KTS IN
THE AFTERNOON WILL USHER IN BITTERLY COLD TEMPS AND WIND CHILLS.
WIDESPREAD WIND CHILL ADVISORY VALUES LOOK PROBABLY THROUGHOUT THE
RIDGE AND VALLEY REGION LATE THURSDAY NIGHT/EARLY FRIDAY...WITH
WARNING CRITERIA /LESS THAN -25C/ POSSIBLE ACROSS PORTIONS OF THE
NORTH AND WEST. THE SUSQ VALLEY MAY ESCAPE THE BRUTALLY COLD WIND
CHILLS WITH APPARENT TEMPS OF -10 TO -14F.
LATER SHIFTS - OVERNIGHT TONIGHT OR WEDNESDAY WILL LIKELY BE
POSTING WIND CHILL WATCH/OR ADVISORY FOR THE AFOREMENTIONED
LOCATIONS.
THE ALLEGHENY PLATEAU. A BITING WIND WILL LIKELY ACCOMPANY THE
SUB- ZERO TEMPS...DUE TO TIGHT PRES GRADIENT WEST OF RAPIDLY
DEVELOPING COASTAL STORM EAST OF NEW ENG.
FRIDAY WILL LIKELY BE ONE OF THE COLDEST DAYS OF THE WINTER SEASON
SO FAR WITH ANOMALOUSLY GEFS MEAN 850 MB TEMPS STILL FCST TO
PLUMMET TO ARND -20C OVER THE AREA. HIGH TEMPS FRIDAY PROJECTED
TO VARY VARY FROM JUST THE SINGLE DIGITS ACROSS THE NORTHERN
MTNS...TO THE MID AND UPPER TEENS ACROSS THE SOUTHERN VALLEYS.
AN EXTENSIVE RIDGE OF HIGH PRESSURE BUILDS EAST ACROSS THE FRIDAY
INTO EARLY FRIDAY NIGHT WITH SLOWLY DECREASING NW WINDS AND
PARTLY TO MOSTLY SUNNY SKIES ACROSS THE CENTRAL AND SE ZONES. THE
NW MTNS MAY HAVE A TOUGH TIME BREAKING UP THE SHALLOW STRATO CU
THOUGH...SO HEDGED TOWARD MSTLY CLOUDY ACROSS THE NRN AND WRN MTNS
/BUT WITH LITTLE MORE THAN SOME FLURRIES/.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE NEXT CAR IN THE CLIPPER TRAIN RIDES ACROSS THE CWA LATE
FRIDAY NIGHT AND SATURDAY...ACCOMPANIED BY NUMEROUS SNOW
SHOWERS...OR EVEN A FEW PERIODS OF STEADY SNOW INTO SATURDAY
EVENING AS SOME MODEL GUIDANCE INDICATES A CLOSED MID/UPPER LOW
CENTER FORMING OVER CENTRAL/ERN PENN BEFORE SCOOTING QUICKLY EAST
OFF THE MID ATLANTIC COAST. AIR BEHIND THIS SYSTEM WILL BE EVEN A
FEW-SVRL DEG F COLDER THAN THE INITIAL LATE WEEK CLIPPER. TEMPS
SHOULD STEADILY FALL /FROM THEIR ALREADY BELOW NORMAL VALUES/
SATURDAY AFTERNOON/EVENING...WITH A FEW SQUALLS EMBEDDED IN THE
LARGER SCALE AREAS OF LIGHTER SNOW.
AS THE SFC LOW RAPIDLY DEEPENS JUST OFF THE MID ATLANTIC/SRN NEW
ENGLAND COAST SAT NIGHT/SUNDAY...NW WINDS WILL INCREASE TO
SUSTAINED SPEEDS IN THE TEENS-LOW 20 KT RANGE WITH GUSTS UP TO 30
KTS...SIMILAR OR COLDER WIND CHILLS /THAN THURSDAY NIGHT`S ARE
EXPECTED BY VERY EARLY SUNDAY/.
A TRUE TASTE OF THE ARCTIC WILL BE PLATED UP FOR RESIDENTS OF
PENN SUNDAY...WITH MEAN GEFS 850 MB TEMPS BOTTOMING OUT IN THE
LOW-MID -20C RANGE - RESULTING IN SFC MAX TEMPS POSSIBLY STAYING
JUST BELOW ZERO ACROSS THE NRN MTNS...AND ONLY REACHING THE UPPER
SINGLE DIGITS TO MID TEENS AT BEST ACROSS THE CENTRAL AND SRN
PORTIONS OF THE STATE.
GRADUAL CLEARING FOR SUNDAY NIGHT/MONDAY AS A LARGE AREA OF HIGH
PRESSURE SETTLES SE ACROSS THE STATE. SHOULD THE WIND DIMINISH AND
SKIES CLEAR OUT QUICK ENOUGH...WIDESPREAD SUB-ZERO TEMPS ARE WOULD
BECOME LIKELY...WITH EVEN SOME RECORD MINS FOR THE DATE POSSIBLE.
FOR A QUICK EXAMPLE...WILLIAMSPORT`S LOW FOR FEB 16TH IS -5F SET
OVER A CENTURY AGO IN 1905...AND OUR FCST LOW THERE NEXT TUESDAY
MORNING IS IS -3F. GEFS MIN TEMP RANGE FOR KITP ON FEB 16TH IS
BETWEEN -3F AND -14F...SO I/M BEING OPTIMISTICALLY WARM- HEARTED
WITH THAT FCST LOW RIGHT AFTER V-DAY.
THE THIRD DIGGING SHORTWAVE /POSSIBLE CABOOSE/ TUESDAY...MAY HELP
TO BRIEFLY CARVE OUT THE MEAN ERN U.S. A LITTLE FURTHER TO THE
WEST /WHILE TEAMING UP WITH SOME SRN STREAM ENERGY/ ALLOWING FOR
SOME GOMEX MOISTURE TO BE PICKED UP BY THE SYSTEM BEFORE IT HEADS
EAST- NORTHEAST TWD THE VA/MID ATLANTIC COAST. FOR NOW...AND AT
THIS TIME RANGE WILL GO WITH ABOVE CLIMO POPS ACROSS THE CENTRAL
AND EAST FOR CHC OF LIGHT SNOW OR SNOW SHOWERS /DEPENDING ON
WHETHER WE SEE A DOMINANT NRN STREAM CLIPPER...OR PHASING NRN AND
SRN STREAM FEATURES/. TEMPS MONDAY AND TUESDAY WILL SLOWLY REBOUND
BUT LIKELY STAY SEVERAL DEG F BELOW NORMAL.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
GIVEN STRONG INVERSION IN PLACE AND TIME OF DAY...DID ADJUST
00Z TAF PACKAGE TO HOLD ONTO LOWER CLDS UNTIL LATE WED MORNING.
THIS MAINLY IN SPOTS WHERE THE CLOUDS ARE NOW. WAS BETTER IN THE
LOCAL AREA AT LUNCH TIME TODAY.
STILL EXPECTING A DECENT AFTERNOON FOR MOST IF NOT ALL THE
AREA ON WED AFT.
CONDITIONS WILL DETERIORATE AFT 00Z THU AS ANOTHER TROUGH DROPS
THROUGH THE GREAT LAKES AND THROUGH PENNSYLVANIA WEDNESDAY NIGHT
INTO THURSDAY.
OUTLOOK...
WED NGT-THU...MVFR/IFR IN -SN. GUSTY NW WINDS THU NIGHT INTO
EARLY FRI BEHIND FROPA.
FRI...MVFR/IFR WITH -SHSN WEST.
SAT...MVFR/IFR WITH -SN.
SUN...MVFR/IFR WEST IN -SHSN. VFR ACROSS THE EAST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...LAMBERT
LONG TERM...FITZGERALD/LAMBERT
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
741 PM EST TUE FEB 10 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL BUILD INTO PENNSYLVANIA OVERNIGHT
AND WEDNESDAY. A PAIR OF POTENT SHORTWAVES AND ASSOCIATED CLIPPERS
WILL CARVE OUT A DEEP UPPER LEVEL TROUGH OVER THE NORTHEAST CONUS
LATE THIS WEEK THROUGH EARLY NEXT WEEK. THESE SYSTEMS WILL BRING
BITTERLY COLD AIR BACK INTO CENTRAL PENNSYLVANIA WHICH WILL LAST
THROUGH THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
740 PM UPDATE...
CLOUDS HANGING TOUGH AND SHOWING NO SIGNS OF GOING AWAY. IN
FACT...THE WEAK NRLY FLOW IS ONLY REINFORCING THEM. WHILE HIGH
PRESSURE IS SLATED TO BUILD IN...CANNOT GO WITH TOO MUCH CLEARING
AS THE SUBSIDENCE INVERSION HAS NOT STARTED TO SHOW UP.
PREV...
AS A RIDGE OF HIGH PRESSURE REMAINS OVER THE REGION...LARGE SCALE
SUBSIDENCE DOMINATES THE FORECAST THROUGH TOMORROW. THE MAIN
CONCERN WILL BE HOW MUCH CLEARING IS OBSERVED. CURRENT HRRR AND
MODEL SOUNDINGS SUGGEST STRATOCU WILL CONTINUE THROUGH THE REST OF
THE AFTERNOON AND INTO THE EVENING. THE WINDS ARE COMING FROM THE
NORTH TO NORTHEAST...AND AS THEY SHIFT TO THE EAST...THERE WILL BE
SOME DRY AIR ADVECTION. THE THICKEST CLOUDS CONTINUE TO BE OVER
THE CENTRAL AND NW MTNS...ESPECIALLY THE LAURELS...WHERE LOW
STRATOCU...UPSLOPE FLOW...AND LOW LEVEL MOISTURE FROM YESTERDAYS
PRECIPITATION AND CORRESPONDING MELTED SNOWPACK HAVE ALLOWED FOR
REDUCED VISIBILITIES AS WELL. THESE CONDITIONS WILL SLOWLY WEAKEN
AS THE NIGHT CONTINUES AS THE RIDGE FLATTENS...AND MORE ZONAL
UPPER LEVEL FLOW MOVES OVER THE REGION FOR TOMORROW.
FAIR WX EXPECTED TONIGHT AS THE DRY AIR MOVES INTO THE
REGION...CLOUDS WILL SLOWLY BREAK UP AND DISSIPATE. IF THE SFC
DECOUPLES OVERNIGHT...THERE IS A CHANCE FOR SOME LOW CLOUDS TO
REDEVELOP...MAINLY OVER THE CENTRAL AND NORTHWEST MOUNTAINS.
LIGHT WINDS...CLEARING SKIES AND SNOW COVER SHOULD ALLOW TEMPS TO
FALL SEVERAL DEG BLW SEASONAL NORMS WITH TEMPERATURES RANGING FROM
THE LOW SINGLE DIGITS IN THE NORTHEAST...TO THE MID TO UPPER TEENS
ELSEWHERE.
OVERALL FAIR WEATHER WILL CONTINUE THROUGH TOMORROW AS A POTENT
SHORTWAVE WILL BE DIVING SOUTHEASTWARD INTO THE GREAT LAKES REGION
LATE WEDNESDAY. THE WINDS SHIFT TO THE NORTHWEST OUT AHEAD OF THIS
TROUGH. THIS SYSTEM WILL BRING AN INCREASE CHANCE FOR
PRECIPITATION THROUGH THE NW MTNS LATE WEDNESDAY.
PARTIAL SUNSHINE AND A BRIEF SHOT OF WAA IN ADVANCE OF CLIPPER
SHOULD HELP TEMPS RECOVER TO NEAR NORMAL WED AFTN WITH MAXES
MOSTLY IN THE LOW TO MID 30S.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
THE WAVE TRAIN OF ALBERTA CLIPPERS BEGINS WEDNESDAY NIGHT AND
THURSDAY. NOT MANY SIGNIFICANT CHANGES HAVE OCCURRED IN THE MODEL
CONSENSUS TRACK AND INTENSITY OF THESE FEATURES OVER THE PAST 24
HOURS...SO MINOR MODIFICATIONS TO POPS...TEMPS..AND WIND/WIND
CHILLS HAVE BEEN MADE WITH THIS ROUND OF GRIDDED DATA.
AFTER A BRIEF...SEVERAL-HOUR PERIOD OF WARM ADVECTION CLOUDS AND
A FEW AREAS OF LIGHT SNOW/SNOW SHOWERS ACROSS NRN AND WRN PENN
LATE WED/WED NIGHT...THE FIRST CLIPPER IS STILL TIMED TO PUSH THE
LEADING EDGE OF AN ARCTIC AIRMASS INTO THE COMMONWEALTH LATE WED
NIGHT AND THURSDAY MORNING.
TEMPS STARTING OUT IN THE 20S THURSDAY MORNING WILL BE FOLLOWED
BY GRADUALLY FALLING TEMPS ALL DAY /AT LEAST ACROSS CENTRAL AND
NWRN PENN/ WITH NUMEROUS SNOW SHOWERS FLYING ACROSS THE
ALLEGHENIES...AND FLURRIES/SCATTERED SNOW SHOWERS OCCURRING
THROUGHOUT THE CENTRAL RIDGE AND VALLEY REGION.
AN ACCUMULATION OF 1-3 INCHES APPEARS POSSIBLE ACROSS THE LAURELS
AND NW MTNS...WHILE JUST A COATING TO ONE HALF OF AN INCH IS
EXPECTED ELSEWHERE.
AS THE LEADING EDGE OF THE VERY COLD MID LEVEL AIR PUSHES SE
ACROSS THE STATE DURING PRIME HEATING OF THE LATE MORNING AND
AFTERNOON HOURS...850-500 MB LAPSE RATES WILL STEEPEN TO AROUND
6.5C/KM WHICH WILL SUPPORT SOME BRIEF...HEAVY SNOW SHOWERS/SQUALLS.
SHOULD THIS SCENARIO BECOME MORE EVIDENT...POPS ACROSS THE SE HALF
OF THE CWA WILL NEED TO BE INCREASED FOR ANTICIPATED LIGHT ACCUMS
OF SNOW.
NW WINDS INCREASING TO 10-18 KTS WITH GUSTS OCNLY TO 25-30 KTS IN
THE AFTERNOON WILL USHER IN BITTERLY COLD TEMPS AND WIND CHILLS.
WIDESPREAD WIND CHILL ADVISORY VALUES LOOK PROBABLY THROUGHOUT THE
RIDGE AND VALLEY REGION LATE THURSDAY NIGHT/EARLY FRIDAY...WITH
WARNING CRITERIA /LESS THAN -25C/ POSSIBLE ACROSS PORTIONS OF THE
NORTH AND WEST. THE SUSQ VALLEY MAY ESCAPE THE BRUTALLY COLD WIND
CHILLS WITH APPARENT TEMPS OF -10 TO -14F.
LATER SHIFTS - OVERNIGHT TONIGHT OR WEDNESDAY WILL LIKELY BE
POSTING WIND CHILL WATCH/OR ADVISORY FOR THE AFOREMENTIONED
LOCATIONS.
THE ALLEGHENY PLATEAU. A BITING WIND WILL LIKELY ACCOMPANY THE
SUB- ZERO TEMPS...DUE TO TIGHT PRES GRADIENT WEST OF RAPIDLY
DEVELOPING COASTAL STORM EAST OF NEW ENG.
FRIDAY WILL LIKELY BE ONE OF THE COLDEST DAYS OF THE WINTER SEASON
SO FAR WITH ANOMALOUSLY GEFS MEAN 850 MB TEMPS STILL FCST TO
PLUMMET TO ARND -20C OVER THE AREA. HIGH TEMPS FRIDAY PROJECTED
TO VARY VARY FROM JUST THE SINGLE DIGITS ACROSS THE NORTHERN
MTNS...TO THE MID AND UPPER TEENS ACROSS THE SOUTHERN VALLEYS.
AN EXTENSIVE RIDGE OF HIGH PRESSURE BUILDS EAST ACROSS THE FRIDAY
INTO EARLY FRIDAY NIGHT WITH SLOWLY DECREASING NW WINDS AND
PARTLY TO MOSTLY SUNNY SKIES ACROSS THE CENTRAL AND SE ZONES. THE
NW MTNS MAY HAVE A TOUGH TIME BREAKING UP THE SHALLOW STRATO CU
THOUGH...SO HEDGED TOWARD MSTLY CLOUDY ACROSS THE NRN AND WRN MTNS
/BUT WITH LITTLE MORE THAN SOME FLURRIES/.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE NEXT CAR IN THE CLIPPER TRAIN RIDES ACROSS THE CWA LATE
FRIDAY NIGHT AND SATURDAY...ACCOMPANIED BY NUMEROUS SNOW
SHOWERS...OR EVEN A FEW PERIODS OF STEADY SNOW INTO SATURDAY
EVENING AS SOME MODEL GUIDANCE INDICATES A CLOSED MID/UPPER LOW
CENTER FORMING OVER CENTRAL/ERN PENN BEFORE SCOOTING QUICKLY EAST
OFF THE MID ATLANTIC COAST. AIR BEHIND THIS SYSTEM WILL BE EVEN A
FEW-SVRL DEG F COLDER THAN THE INITIAL LATE WEEK CLIPPER. TEMPS
SHOULD STEADILY FALL /FROM THEIR ALREADY BELOW NORMAL VALUES/
SATURDAY AFTERNOON/EVENING...WITH A FEW SQUALLS EMBEDDED IN THE
LARGER SCALE AREAS OF LIGHTER SNOW.
AS THE SFC LOW RAPIDLY DEEPENS JUST OFF THE MID ATLANTIC/SRN NEW
ENGLAND COAST SAT NIGHT/SUNDAY...NW WINDS WILL INCREASE TO
SUSTAINED SPEEDS IN THE TEENS-LOW 20 KT RANGE WITH GUSTS UP TO 30
KTS...SIMILAR OR COLDER WIND CHILLS /THAN THURSDAY NIGHT`S ARE
EXPECTED BY VERY EARLY SUNDAY/.
A TRUE TASTE OF THE ARCTIC WILL BE PLATED UP FOR RESIDENTS OF
PENN SUNDAY...WITH MEAN GEFS 850 MB TEMPS BOTTOMING OUT IN THE
LOW-MID -20C RANGE - RESULTING IN SFC MAX TEMPS POSSIBLY STAYING
JUST BELOW ZERO ACROSS THE NRN MTNS...AND ONLY REACHING THE UPPER
SINGLE DIGITS TO MID TEENS AT BEST ACROSS THE CENTRAL AND SRN
PORTIONS OF THE STATE.
GRADUAL CLEARING FOR SUNDAY NIGHT/MONDAY AS A LARGE AREA OF HIGH
PRESSURE SETTLES SE ACROSS THE STATE. SHOULD THE WIND DIMINISH AND
SKIES CLEAR OUT QUICK ENOUGH...WIDESPREAD SUB-ZERO TEMPS ARE WOULD
BECOME LIKELY...WITH EVEN SOME RECORD MINS FOR THE DATE POSSIBLE.
FOR A QUICK EXAMPLE...WILLIAMSPORT`S LOW FOR FEB 16TH IS -5F SET
OVER A CENTURY AGO IN 1905...AND OUR FCST LOW THERE NEXT TUESDAY
MORNING IS IS -3F. GEFS MIN TEMP RANGE FOR KITP ON FEB 16TH IS
BETWEEN -3F AND -14F...SO I/M BEING OPTIMISTICALLY WARM- HEARTED
WITH THAT FCST LOW RIGHT AFTER V-DAY.
THE THIRD DIGGING SHORTWAVE /POSSIBLE CABOOSE/ TUESDAY...MAY HELP
TO BRIEFLY CARVE OUT THE MEAN ERN U.S. A LITTLE FURTHER TO THE
WEST /WHILE TEAMING UP WITH SOME SRN STREAM ENERGY/ ALLOWING FOR
SOME GOMEX MOISTURE TO BE PICKED UP BY THE SYSTEM BEFORE IT HEADS
EAST- NORTHEAST TWD THE VA/MID ATLANTIC COAST. FOR NOW...AND AT
THIS TIME RANGE WILL GO WITH ABOVE CLIMO POPS ACROSS THE CENTRAL
AND EAST FOR CHC OF LIGHT SNOW OR SNOW SHOWERS /DEPENDING ON
WHETHER WE SEE A DOMINANT NRN STREAM CLIPPER...OR PHASING NRN AND
SRN STREAM FEATURES/. TEMPS MONDAY AND TUESDAY WILL SLOWLY REBOUND
BUT LIKELY STAY SEVERAL DEG F BELOW NORMAL.
&&
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
GIVEN STRONG INVERSION IN PLACE AND TIME OF DAY...DID ADJUST
00Z TAF PACKAGE TO HOLD ONTO LOWER CLDS UNTIL LATE WED MORNING.
THIS MAINLY IN SPOTS WHERE THE CLOUDS ARE NOW. WAS BETTER IN THE
LOCAL AREA AT LUNCH TIME TODAY.
STILL EXPECTING A DECENT AFTERNOON FOR MOST IF NOT ALL THE
AREA ON WED AFT.
CONDITIONS WILL DETERIORATE AFT 00Z THU AS ANOTHER TROUGH DROPS
THROUGH THE GREAT LAKES AND THROUGH PENNSYLVANIA WEDNESDAY NIGHT
INTO THURSDAY.
OUTLOOK...
WED NGT-THU...MVFR/IFR IN -SN. GUSTY NW WINDS THU NIGHT INTO
EARLY FRI BEHIND FROPA.
FRI...MVFR/IFR WITH -SHSN WEST.
SAT...MVFR/IFR WITH -SN.
SUN...MVFR/IFR WEST IN -SHSN. VFR ACROSS THE EAST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...LAMBERT
LONG TERM...FITZGERALD/LAMBERT
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
637 PM EST TUE FEB 10 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL BUILD INTO PENNSYLVANIA TODAY AND
WEDNESDAY. A PAIR OF POTENT SHORTWAVES AND ASSOC CLIPPERS WILL
CARVE OUT A DEEP UPPER LVL TROUGH OVER THE NORTHEAST CONUS LATE
THIS WEEK THROUGH EARLY NEXT WEEK. THESE SYSTEMS WILL BRING COLD
BITTER AIR BACK INTO CENTRAL PENNSYLVANIA THROUGH THE SECOND HALF
OF THE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS A RIDGE OF HIGH PRESSURE REMAINS OVER THE REGION...LARGE SCALE
SUBSIDENCE DOMINATES THE FORECAST THROUGH TOMORROW. THE MAIN
CONCERN WILL BE HOW MUCH CLEARING IS OBSERVED. CURRENT HRRR AND
MODEL SOUNDINGS SUGGEST STRATOCU WILL CONTINUE THROUGH THE REST OF
THE AFTERNOON AND INTO THE EVENING. THE WINDS ARE COMING FROM THE
NORTH TO NORTHEAST...AND AS THEY SHIFT TO THE EAST...THERE WILL BE
SOME DRY AIR ADVECTION. THE THICKEST CLOUDS CONTINUE TO BE OVER
THE CENTRAL AND NW MTNS...ESPECIALLY THE LAURELS...WHERE LOW
STRATOCU...UPSLOPE FLOW...AND LOW LEVEL MOISTURE FROM YESTERDAYS
PRECIPITATION AND CORRESPONDING MELTED SNOWPACK HAVE ALLOWED FOR
REDUCED VISIBILITIES AS WELL. THESE CONDITIONS WILL SLOWLY WEAKEN
AS THE NIGHT CONTINUES AS THE RIDGE FLATTENS...AND MORE ZONAL
UPPER LEVEL FLOW MOVES OVER THE REGION FOR TOMORROW.
FAIR WX EXPECTED TONIGHT AS THE DRY AIR MOVES INTO THE
REGION...CLOUDS WILL SLOWLY BREAK UP AND DISSIPATE. IF THE SFC
DECOUPLES OVERNIGHT...THERE IS A CHANCE FOR SOME LOW CLOUDS TO
REDEVELOP...MAINLY OVER THE CENTRAL AND NORTHWEST MOUNTAINS.
LIGHT WINDS...CLEARING SKIES AND SNOW COVER SHOULD ALLOW TEMPS TO
FALL SEVERAL DEG BLW SEASONAL NORMS WITH TEMPERATURES RANGING FROM
THE LOW SINGLE DIGITS IN THE NORTHEAST...TO THE MID TO UPPER TEENS
ELSEWHERE.
OVERALL FAIR WEATHER WILL CONTINUE THROUGH TOMORROW AS A POTENT
SHORTWAVE WILL BE DIVING SOUTHEASTWARD INTO THE GREAT LAKES REGION
LATE WEDNESDAY. THE WINDS SHIFT TO THE NORTHWEST OUT AHEAD OF THIS
TROUGH. THIS SYSTEM WILL BRING AN INCREASE CHANCE FOR
PRECIPITATION THROUGH THE NW MTNS LATE WEDNESDAY.
PARTIAL SUNSHINE AND A BRIEF SHOT OF WAA IN ADVANCE OF CLIPPER
SHOULD HELP TEMPS RECOVER TO NEAR NORMAL WED AFTN WITH MAXES
MOSTLY IN THE LOW TO MID 30S.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
THE WAVE TRAIN OF ALBERTA CLIPPERS BEGINS WEDNESDAY NIGHT AND
THURSDAY. NOT MANY SIGNIFICANT CHANGES HAVE OCCURRED IN THE MODEL
CONSENSUS TRACK AND INTENSITY OF THESE FEATURES OVER THE PAST 24
HOURS...SO MINOR MODIFICATIONS TO POPS...TEMPS..AND WIND/WIND
CHILLS HAVE BEEN MADE WITH THIS ROUND OF GRIDDED DATA.
AFTER A BRIEF...SEVERAL-HOUR PERIOD OF WARM ADVECTION CLOUDS AND
A FEW AREAS OF LIGHT SNOW/SNOW SHOWERS ACROSS NRN AND WRN PENN
LATE WED/WED NIGHT...THE FIRST CLIPPER IS STILL TIMED TO PUSH THE
LEADING EDGE OF AN ARCTIC AIRMASS INTO THE COMMONWEALTH LATE WED
NIGHT AND THURSDAY MORNING.
TEMPS STARTING OUT IN THE 20S THURSDAY MORNING WILL BE FOLLOWED
BY GRADUALLY FALLING TEMPS ALL DAY /AT LEAST ACROSS CENTRAL AND
NWRN PENN/ WITH NUMEROUS SNOW SHOWERS FLYING ACROSS THE
ALLEGHENIES...AND FLURRIES/SCATTERED SNOW SHOWERS OCCURRING
THROUGHOUT THE CENTRAL RIDGE AND VALLEY REGION.
AN ACCUMULATION OF 1-3 INCHES APPEARS POSSIBLE ACROSS THE LAURELS
AND NW MTNS...WHILE JUST A COATING TO ONE HALF OF AN INCH IS
EXPECTED ELSEWHERE.
AS THE LEADING EDGE OF THE VERY COLD MID LEVEL AIR PUSHES SE
ACROSS THE STATE DURING PRIME HEATING OF THE LATE MORNING AND
AFTERNOON HOURS...850-500 MB LAPSE RATES WILL STEEPEN TO AROUND
6.5C/KM WHICH WILL SUPPORT SOME BRIEF...HEAVY SNOW SHOWERS/SQUALLS.
SHOULD THIS SCENARIO BECOME MORE EVIDENT...POPS ACROSS THE SE HALF
OF THE CWA WILL NEED TO BE INCREASED FOR ANTICIPATED LIGHT ACCUMS
OF SNOW.
NW WINDS INCREASING TO 10-18 KTS WITH GUSTS OCNLY TO 25-30 KTS IN
THE AFTERNOON WILL USHER IN BITTERLY COLD TEMPS AND WIND CHILLS.
WIDESPREAD WIND CHILL ADVISORY VALUES LOOK PROBABLY THROUGHOUT THE
RIDGE AND VALLEY REGION LATE THURSDAY NIGHT/EARLY FRIDAY...WITH
WARNING CRITERIA /LESS THAN -25C/ POSSIBLE ACROSS PORTIONS OF THE
NORTH AND WEST. THE SUSQ VALLEY MAY ESCAPE THE BRUTALLY COLD WIND
CHILLS WITH APPARENT TEMPS OF -10 TO -14F.
LATER SHIFTS - OVERNIGHT TONIGHT OR WEDNESDAY WILL LIKELY BE
POSTING WIND CHILL WATCH/OR ADVISORY FOR THE AFOREMENTIONED
LOCATIONS.
THE ALLEGHENY PLATEAU. A BITING WIND WILL LIKELY ACCOMPANY THE
SUB- ZERO TEMPS...DUE TO TIGHT PRES GRADIENT WEST OF RAPIDLY
DEVELOPING COASTAL STORM EAST OF NEW ENG.
FRIDAY WILL LIKELY BE ONE OF THE COLDEST DAYS OF THE WINTER SEASON
SO FAR WITH ANOMALOUSLY GEFS MEAN 850 MB TEMPS STILL FCST TO
PLUMMET TO ARND -20C OVER THE AREA. HIGH TEMPS FRIDAY PROJECTED
TO VARY VARY FROM JUST THE SINGLE DIGITS ACROSS THE NORTHERN
MTNS...TO THE MID AND UPPER TEENS ACROSS THE SOUTHERN VALLEYS.
AN EXTENSIVE RIDGE OF HIGH PRESSURE BUILDS EAST ACROSS THE FRIDAY
INTO EARLY FRIDAY NIGHT WITH SLOWLY DECREASING NW WINDS AND
PARTLY TO MOSTLY SUNNY SKIES ACROSS THE CENTRAL AND SE ZONES. THE
NW MTNS MAY HAVE A TOUGH TIME BREAKING UP THE SHALLOW STRATO CU
THOUGH...SO HEDGED TOWARD MSTLY CLOUDY ACROSS THE NRN AND WRN MTNS
/BUT WITH LITTLE MORE THAN SOME FLURRIES/.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE NEXT CAR IN THE CLIPPER TRAIN RIDES ACROSS THE CWA LATE
FRIDAY NIGHT AND SATURDAY...ACCOMPANIED BY NUMEROUS SNOW
SHOWERS...OR EVEN A FEW PERIODS OF STEADY SNOW INTO SATURDAY
EVENING AS SOME MODEL GUIDANCE INDICATES A CLOSED MID/UPPER LOW
CENTER FORMING OVER CENTRAL/ERN PENN BEFORE SCOOTING QUICKLY EAST
OFF THE MID ATLANTIC COAST. AIR BEHIND THIS SYSTEM WILL BE EVEN A
FEW-SVRL DEG F COLDER THAN THE INITIAL LATE WEEK CLIPPER. TEMPS
SHOULD STEADILY FALL /FROM THEIR ALREADY BELOW NORMAL VALUES/
SATURDAY AFTERNOON/EVENING...WITH A FEW SQUALLS EMBEDDED IN THE
LARGER SCALE AREAS OF LIGHTER SNOW.
AS THE SFC LOW RAPIDLY DEEPENS JUST OFF THE MID ATLANTIC/SRN NEW
ENGLAND COAST SAT NIGHT/SUNDAY...NW WINDS WILL INCREASE TO
SUSTAINED SPEEDS IN THE TEENS-LOW 20 KT RANGE WITH GUSTS UP TO 30
KTS...SIMILAR OR COLDER WIND CHILLS /THAN THURSDAY NIGHT`S ARE
EXPECTED BY VERY EARLY SUNDAY/.
A TRUE TASTE OF THE ARCTIC WILL BE PLATED UP FOR RESIDENTS OF
PENN SUNDAY...WITH MEAN GEFS 850 MB TEMPS BOTTOMING OUT IN THE
LOW-MID -20C RANGE - RESULTING IN SFC MAX TEMPS POSSIBLY STAYING
JUST BELOW ZERO ACROSS THE NRN MTNS...AND ONLY REACHING THE UPPER
SINGLE DIGITS TO MID TEENS AT BEST ACROSS THE CENTRAL AND SRN
PORTIONS OF THE STATE.
GRADUAL CLEARING FOR SUNDAY NIGHT/MONDAY AS A LARGE AREA OF HIGH
PRESSURE SETTLES SE ACROSS THE STATE. SHOULD THE WIND DIMINISH AND
SKIES CLEAR OUT QUICK ENOUGH...WIDESPREAD SUB-ZERO TEMPS ARE WOULD
BECOME LIKELY...WITH EVEN SOME RECORD MINS FOR THE DATE POSSIBLE.
FOR A QUICK EXAMPLE...WILLIAMSPORT`S LOW FOR FEB 16TH IS -5F SET
OVER A CENTURY AGO IN 1905...AND OUR FCST LOW THERE NEXT TUESDAY
MORNING IS IS -3F. GEFS MIN TEMP RANGE FOR KITP ON FEB 16TH IS
BETWEEN -3F AND -14F...SO I/M BEING OPTIMISTICALLY WARM- HEARTED
WITH THAT FCST LOW RIGHT AFTER V-DAY.
THE THIRD DIGGING SHORTWAVE /POSSIBLE CABOOSE/ TUESDAY...MAY HELP
TO BRIEFLY CARVE OUT THE MEAN ERN U.S. A LITTLE FURTHER TO THE
WEST /WHILE TEAMING UP WITH SOME SRN STREAM ENERGY/ ALLOWING FOR
SOME GOMEX MOISTURE TO BE PICKED UP BY THE SYSTEM BEFORE IT HEADS
EAST- NORTHEAST TWD THE VA/MID ATLANTIC COAST. FOR NOW...AND AT
THIS TIME RANGE WILL GO WITH ABOVE CLIMO POPS ACROSS THE CENTRAL
AND EAST FOR CHC OF LIGHT SNOW OR SNOW SHOWERS /DEPENDING ON
WHETHER WE SEE A DOMINANT NRN STREAM CLIPPER...OR PHASING NRN AND
SRN STREAM FEATURES/. TEMPS MONDAY AND TUESDAY WILL SLOWLY REBOUND
BUT LIKELY STAY SEVERAL DEG F BELOW NORMAL.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
GIVEN STRONG INVERSION IN PLACE AND TIME OF DAY...DID ADJUST
00Z TAF PACKAGE TO HOLD ONTO LOWER CLDS UNTIL LATE WED MORNING.
THIS MAINLY IN SPOTS WHERE THE CLOUDS ARE NOW. WAS BETTER IN THE
LOCAL AREA AT LUNCH TIME TODAY.
STILL EXPECTING A DECENT AFTERNOON FOR MOST IF NOT ALL THE
AREA ON WED AFT.
CONDITIONS WILL DETERIORATE AFT 00Z THU AS ANOTHER TROUGH DROPS
THROUGH THE GREAT LAKES AND THROUGH PENNSYLVANIA WEDNESDAY NIGHT
INTO THURSDAY.
OUTLOOK...
WED NGT-THU...MVFR/IFR IN -SN. GUSTY NW WINDS THU NIGHT INTO
EARLY FRI BEHIND FROPA.
FRI...MVFR/IFR WITH -SHSN WEST.
SAT...MVFR/IFR WITH -SN.
SUN...MVFR/IFR WEST IN -SHSN. VFR ACROSS THE EAST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD/CERU
NEAR TERM...FITZGERALD/CERU/MARTIN
SHORT TERM...LAMBERT
LONG TERM...FITZGERALD/LAMBERT
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
408 PM EST MON FEB 9 2015
.SYNOPSIS...
LOW PRESSURE WILL SLIDE EASTWARD THROUGH THE AREA TODAY. COLD AIR
WILL REMAIN FOR MIDWEEK BEFORE ANOTHER FRONTAL SYSTEM APPROACHES
FROM THE UPPER GREAT LAKES THURSDAY. BITTERLY COLD AIR WILL
FOLLOW FOR THE END OF THE WEEK AND WEEKEND.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
THE SURFACE LOW CONTINUES TO MOVE THROUGH CENTRAL PA THIS
AFTERNOON. THE BULK OF THIS STORMS ENERGY HAS MOVED OFF TO THE
EAST...HOWEVER A CLUSTER OF RAIN SHOWERS IS CURRENTLY MOVING
THROUGH THE LAURELS AND SOUTHERN HALF OF PA...SPREADING THROUGH
THE LOWER SUSQ AND CENTRAL PA LATE THIS AFTERNOON AND THIS
EVENING. THE BIG QUESTION IS WHERE TEMPERATURES WILL BE. WARM AIR
REMAINS OVER THE LAURELS AND COLD AIR IS HOLDING OVER THE LOWER
SUSQ. DUE TO THE TRACK OF THE PRECIPITATION...THE LATEST HRRR AND
SHORT RANGE MODELS...AND SFC TEMPERATURES...HAVE EXTENDED THE
FREEZING RAIN ADVISORY. IF THE TEMPERATURES DROP FASTER IN THE
NORTH...IT MAY NEED TO BE EXPANDED. AS THE TEMPERATURES DROP BOTH
AT THE SURFACE AND ALOFT AS THE UPPER LEVEL TROUGH PROGRESSES
EASTWARD...THE RAIN/FREEZING RAIN WILL TRANSITION TO SNOW. EXPECT
THIS TO OCCUR 22Z TO 02Z.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM TUESDAY/...
AS PRECIPITATION CONTINUES TO FADE THIS EVENING THE MIXED
PRECIPITATION SHOULD PERSIST THROUGH THE FIRST HALF OF THE
EVENING IN THE FAR SOUTHEAST. HOWEVER...AS TEMPERATURES CONTINUE
TO DROP ALOFT...LIGHT SNOWFALL REMAINS PROBABLE ACROSS THE
SOUTHERN HALF OF PA THROUGH THE FIRST HALF OF THE EVENING. THE
MOISTURE WILL DIMINISH AND CUTS OFF ALTOGETHER LATE TONIGHT. THERE
IS STILL A SLIGHT CHANCE FOR LIGHT SNOWFALL ACROSS THE NORTHERN
PORTION OF PENNSYLVANIA. THE MODEL SOUNDINGS HAVE CONTINUED TO
COOL...WHICH MAKES ANY FREEZING DRIZZLE ACROSS THE NORTH LESS
LIKELY. HOWEVER HAVE LEFT MENTION OF PATCHY FREEZING DRIZZLE
POSSIBLE.
AS THE WEAK HIGH BUILDS OVER THE REGION TUESDAY...COLD DRY AIR
SHOULD DOMINATE WITH HIGH TEMPERATURES CONTINUING TO RUN ABOUT 5
DEGREES BELOW NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
TUESDAY NIGHT/WEDNESDAY WILL START OUT WITH FAIR WEATHER AS A
RIDGE OF HIGH PRESSURE AT THE SURFACE AND ALOFT SLIDES ESE ACROSS
THE REGION. EXPECT PARTLY TO MOSTLY SUNNY SKIES WEDNESDAY MORNING
WITH LIGHT AND VARIABLE WIND AND NEAR NORMAL MIN TEMPS.
WINDS WILL BECOME LIGHT FROM THE SOUTH IN THE AFTERNOON AS THE
RIDGE SLIDES EAST AND A DECK OF MAINLY MID- LEVEL CLOUDS
INCREASES FROM THE WEST. SFC TEMPS WED AFTERNOON WILL BE A FEW TO
SVRL DEG F BELOW NORMAL /WITH TEMPS IN THE 925-850 MB ALSO CLOSE
TO NORMAL/.
BIG CHANGES OCCUR FOR LATE IN THE WEEK BEHIND AN INITIAL ARCTIC
FRONT THAT WILL PLOW SE ACROSS THE STATE LATER WEDNESDAY NIGHT
/NW/ AND THURSDAY MORNING /SERN ZONES/. PAINTED LIKELY POPS FOR
SNOW SHOWERS ACROSS THE NRN AND WESTERN MTNS AS LIMITED LAKE
MOISTURE IS FED INTO THE VERY COLD AIR AND LIFTED ACROSS THE
ALLEGHENIES. POPS MAY EASILY BE UNDERDONE...AND THERE COULD BE
AT LEAST A FEW INCHES OF SNOW ACROSS THE FAVORED UPSLOPE AREAS AS
THE BASE OF THE SUBSIDENCE INVERSION LIFTS TO BETWEEN 7-9 KFT AGL.
EXPECT STEADILY FALLING TEMPS ALL DAY THURSDAY WITH NORTHWEST
WINDS GUSTING UP TO 30 KTS AT TIMES. THIS WILL LEAD TO WIND CHILLS
FALLING WELL INTO THE SINGLE DIGITS BY LATE AFTERNOON...THEN WELL
BELOW ZERO AND LIKELY INTO AT LEAST THE WIND CHILLY ADVISORY RANGE
ACROSS THE NRN AND WRN MTNS. PORTIONS OF THE NRN MTNS COULD
APPROACH WIND CHILL WARNING CRITERIA OF -25F.
FRIDAY WILL LIKELY BE ONE OF THE COLDEST DAYS OF THE WINTER SEASON
SO FAR WITH ANOMALOUSLY GEFS MEAN 850 MB TEMPS /-20 TO -22C/
RIGHT OVER THE ALLEGHENIES/. HIGH TEMPS WILL VARY FROM JUST THE
SINGLE DIGITS ACROSS THE NORTHERN MTNS...TO THE MID AND UPPER
TEENS ACROSS THE SOUTHERN VALLEYS. THIS WILL BE ABOUT 20F BELOW
NORMAL IN MANY LOCATIONS.
ANOTHER COLD NIGHT FRIDAY NIGHT...BUT WITH LESS WIND AS A RIDGE OF
HIGH PRESSURE SLIDES SE ACROSS PENN. TEMPS REBOUND BY ABOUT 7-10
DEG F FROM FRIDAY/S HIGHS...FOLLOWED BY YET ANOTHER STRONG
CLIPPER DIGGING IT/S WAY ACROSS THE UPPER MIDWEST/GLAKES REGION.
THE AIR BEHIND THIS FEATURE COULD BE EVEN A FEW DEG C COLDER WITH
850 TEMPS IN THE MID -20S OVER THE CWA. A FEW PERIODS OF SNOW/SNOW
SHOWERS WILL ACCOMPANY THE PASSAGE OF THIS FEATURE.
SATURDAY COULD BE A NEAR REPEAT OF THURSDAY WITH TEMPS FALLING
THROUGHOUT THE DAY /BUT STARTING OUT AT COLDER LEVELS/. IT/S A
LONG WAY OFF...BUT BASED ON EC ENSEMBLE MEAN TEMPS AND THE 12Z
GEFS...SUNDAY COULD BE THE COLDEST DAY WE/LL SEE UNTIL AT LEAST
NEXT WINTER. OUR CURRENT... GRIDDED FCST TEMPS ARE AT THE HIGHER
END OF MOST SOLUTIONS...IN THE SINGLE DIGITS NORTH...AND LOWER TO
MID TEENS TO THE SOUTH OF INTERSTATE 80.
A GRADUAL WARMUP OCCURS EARLY NEXT WEEK /BUT TEMPS MONDAY AND
TUESDAY SHOULD STILL BE SEVERAL DEG F OR MORE BELOW NORMAL/.
OUTLOOK...
TUE...AM LOW CIGS WITH PM IMPROVEMENT.
WED-THU...MVFR/IFR IN -SN.
THU NGT-FRI...GUSTY NW WINDS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ028-
036-056-057-059-063>066.
&&
$$
SYNOPSIS...DANGELO/CERU
NEAR TERM...CERU
SHORT TERM...CERU
LONG TERM...LAMBERT
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
305 PM EST MON FEB 9 2015
.SYNOPSIS...
LOW PRESSURE WILL SLIDE EASTWARD THROUGH THE AREA TODAY. COLD AIR
WILL REMAIN FOR MIDWEEK BEFORE ANOTHER FRONTAL SYSTEM APPROACHES
FROM THE UPPER GREAT LAKES THURSDAY. BITTERLY COLD AIR WILL
FOLLOW FOR THE END OF THE WEEK AND WEEKEND.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
THE SURFACE LOW CONTINUES TO MOVE THROUGH CENTRAL PA THIS
AFTERNOON. THE BULK OF THIS STORMS ENERGY HAS MOVED OFF TO THE
EAST...HOWEVER A CLUSTER OF RAIN SHOWERS IS CURRENTLY MOVING
THROUGH THE LAURELS AND SOUTHERN HALF OF PA...SPREADING THROUGH
THE LOWER SUSQ AND CENTRAL PA LATE THIS AFTERNOON AND THIS
EVENING. THE BIG QUESTION IS WHERE TEMPERATURES WILL BE. WARM AIR
REMAINS OVER THE LAURELS AND COLD AIR IS HOLDING OVER THE LOWER
SUSQ. DUE TO THE TRACK OF THE PRECIPITATION...THE LATEST HRRR AND
SHORT RANGE MODELS...AND SFC TEMPERATURES...HAVE EXTENDED THE
FREEZING RAIN ADVISORY. IF THE TEMPERATURES DROP FASTER IN THE
NORTH...IT MAY NEED TO BE EXPANDED. AS THE TEMPERATURES DROP BOTH
AT THE SURFACE AND ALOFT AS THE UPPER LEVEL TROUGH PROGRESSES
EASTWARD...THE RAIN/FREEZING RAIN WILL TRANSITION TO SNOW. EXPECT
THIS TO OCCUR 22Z TO 02Z.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM TUESDAY/...
AS PRECIPITATION CONTINUES TO FADE THIS EVENING THE MIXED
PRECIPITATION SHOULD PERSIST THROUGH THE FIRST HALF OF THE
EVENING IN THE FAR SOUTHEAST. HOWEVER...AS TEMPERATURES CONTINUE
TO DROP ALOFT...LIGHT SNOWFALL REMAINS PROBABLE ACROSS THE
SOUTHERN HALF OF PA THROUGH THE FIRST HALF OF THE EVENING. THE
MOISTURE WILL DIMINISH AND CUTS OFF ALTOGETHER LATE TONIGHT. THERE
IS STILL A SLIGHT CHANCE FOR LIGHT SNOWFALL ACROSS THE NORTHERN
PORTION OF PENNSYLVANIA. THE MODEL SOUNDINGS HAVE CONTINUED TO
COOL...WHICH MAKES ANY FREEZING DRIZZLE ACROSS THE NORTH LESS
LIKELY. HOWEVER HAVE LEFT MENTION OF PATCHY FREEZING DRIZZLE
POSSIBLE.
AS THE WEAK HIGH BUILDS OVER THE REGION TUESDAY...COLD DRY AIR
SHOULD DOMINATE WITH HIGH TEMPERATURES CONTINUING TO RUN ABOUT 5
DEGREES BELOW NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE LARGE UPPER LEVEL TROUGH SHOULD MOVE OFF THE COAST AND OUT INTO
THE ATLANTIC TUESDAY EVENING. IN ITS WAKE...A WEAK RIDGE FOLLOWED BY
PREDOMINATELY ZONAL FLOW WILL OVERTAKE THE REGION WEDNESDAY. THE
WEST TO NORTHWESTERLY FLOW WILL BRING DRYING CONDITIONS AND A
CLEARING OF SKIES EARLY WEDNESDAY. HOWEVER THIS WILL BE SHORT LIVED
AS A MID LEVEL LOW AND ASSOCIATED TROUGH WILL MOVING INTO THE
REGION WEDNESDAY NIGHT INTO THURSDAY. THE UPPER LEVEL FLOW IS MORE
DIVERGENT...BUT MID LEVEL MOISTURE AND A WEAK SHORT WAVE SHOULD
COUPLE WITH UPSLOPE ENHANCEMENT TO BRING LIGHT SNOWFALLS THROUGH
THIS TIMEFRAME. CURRENT ENSEMBLES SHOW THE UPPER LEVEL LOW SHOULD
MOVE INTO EASTERN CANADA THURSDAY AS ITS CORRESPONDING TROUGH WILL
TREK THROUGH THE GREAT LAKES AND THROUGH PENNSYLVANIA THURSDAY
EVENING. THIS SYSTEM SHOULD BE MAINLY COLD AND DRY. CURRENT MID TO
LONG RANGE MODELS ARE IN FAIR AGREEMENT ON THE STRENGTH AND
POSITION OF THIS SYSTEM. SNOWFALL IS PROBABLE IN THE HIGHER
ELEVATIONS...INCLUDING THE WESTERN AND CENTRAL MOUNTAINS...THOUGH
WITH LOW QPF/S SNOWFALL SHOULD BE LIGHT. THE BIGGEST TAKEAWAY FROM
THIS SYSTEM IS THE STRONG COLD AIR ADVECTION THAT WILL FOLLOW IN
ITS WAKE AS AN ARCTIC AIRMASS WILL DROP DOWN...850MB TEMPS ARE
PROGGED IN THE -16C TO -23C RANGE.
OVERNIGHT LOWS THURSDAY NIGHT INTO FRIDAY MORNING COULD BE IN THE
UPPER SINGLE DIGITS THROUGH THE LOWER SUSQ...TO AROUND ZERO IN THE
NW MTNS. THE STRONG NORTHWEST GRADIENT COULD ALSO ALLOW FOR
PERSISTENT WINDS THROUGH THIS TIMEFRAME WHICH COULD ALLOW WIND
CHILLS TO BE A CONCERN. THIS COLD AIR SHOULD SIT OVER THE REGION
INTO THE WEEKEND. THE TIMING OF THE NEXT LOW TO MOVE THE REGION IS
IN QUESTION. CURRENTLY IT LOOKS TO FOLLOW QUICKLY BEHIND THE LATE
WORK WEEK SYSTEM....TRAVERSING THROUGH THE GREAT LAKES REGION BY
SATURDAY EVENING. THAT SYSTEM SEEMS SIMILAR TO THE PREVIOUS
STORM...THOUGH IT SEEMS TO HAVE BETTER DYNAMICS AND COULD BRING
ANOTHER SHOT OF SNOW TO CENTRAL PA SATURDAY NIGHT INTO SUNDAY. AS
THERE IS STILL SOME DISCONTINUITY AND VARIANCE IN TIMING...
CONFIDENCE IS LOW CURRENTLY.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
WIDESPREAD BELOW IFR CONDITIONS CONTINUE TO DOMINATE THE REGION AS
LOW CIGS CONTINUE DUE TO THE LOW STRATOCU FROM THE SFC LOW
TRACKING THROUGH THE REGION. THESE CIGS...AND LOW VSBYS ACROSS THE
CENTRAL MOUNTAINS WILL CONTINUE THROUGH THE FIRST HALF OF THE
EVENING...BEFORE SLOWLY IMPROVING TOWARDS MORNING.
IPT...BEING FURTHEST TO THE NORTH WILL HAVE THE QUICKEST CLEARING
AS THE UPPER LEVEL TROUGH SWINGS THROUGH. HOWEVER MVFR CIGS WILL
CONTINUE AT IPT INTO TOMORROW MORNING.
THE LOW CIGS WILL SLOWLY IMPROVE BETWEEN 10 TO 15Z TOMORROW
MORNING WITH VFR DOMINATING TOMORROW AS A WEAK HIGH BUILD IN.
OUTLOOK...
TUE...AM LOW CIGS WITH PM IMPROVEMENT.
WED-THU...MVFR/IFR IN -SN.
THU NGT-FRI...GUSTY NW WINDS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ028-
036-056-057-059-063>066.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...CERU
AVIATION...LAMBERT/GARTNER
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1150 AM CST MON FEB 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CST MON FEB 9 2015
EASTERLY FLOW WILL LOCK IN THE LOW LEVEL MOISTURE...RESULTING IN LOW
STRATUS LINGERING THROUGH THE DAY. PATCHY FOG IS ALSO LIKELY AT
LEAST THROUGH THE MORNING HOURS. AN AREA OF DENSE FOG HAS FORMED ON
THE EDGE OF THE STRATUS ACROSS OUR SOUTH CENTRAL SD COUNTIES. HAVE A
DENSE FOG ADVISORY THERE THROUGH 15Z. HRRR HAS A DECENT HANDLE ON
THIS AREA...AND SUGGESTS VISIBILITIES SHOULD START IMPROVING BY MID
MORNING...WITH GREGORY COUNTY THE LAST TO IMPROVE. FREEZING DRIZZLE
POTENTIAL IS STILL UNCERTAIN. LOW LEVEL MOISTURE IS PRETTY
DEEP...BUT A LACK OF A LOW LEVEL LIFTING MECHANISM IS PROBABLY
HOLDING DRIZZLE AT BAY AT THIS POINT. WILL LEAVE A MENTION IN THE
FORECAST THIS MORNING THOUGH...GIVEN THE DEEP SATURATION AND MODELS
HINTING IN A SLIGHT UPTICK IN LOW LEVEL LIFT. AT THIS TIME NOT
EXPECTING ANY DRIZZLE TO BE HEAVY ENOUGH TO CAUSE PROBLEMS...BUT DAY
SHIFT WILL HAVE TO MONITOR. GIVEN THE LOW CLOUDS...CUT BACK HIGHS
TODAY AS NOT THINKING WE WARM MUCH. SO LOOKING AT MAINLY UPPER 20S
EAST TO 30S WEST.
ATTENTION THEN TURNS TO OUR NEXT SYSTEM MOVING ACROSS THE NORTHERN
PLAINS TONIGHT...WITH PRECIPITATION MOVING EAST ACROSS THE AREA
AFTER MIDNIGHT. MODELS ARE FOCUSING IN ON A SOLUTION SLIGHTLY
FURTHER NORTH THAN THEY WERE SHOWING YESTERDAY. THIS RESULTS IN THE
BEST MID LEVEL MOISTURE AND HIGHEST QPF STAYING NORTH. STILL SEE A
DECENT PERIOD OF LIFT MOVE ACROSS OUR AREA...BUT THE DRY AIR WILL
GREATLY CUT INTO PRECIPITATION AMOUNTS. THROUGH 12Z GENERALLY
LOOKING AT LESS THAN FIVE HUNDREDTHS OF QPF...GREATEST IN THE NORTH
ALONG THE HIGHWAY 14 CORRIDOR. THE NORTHERN SOLUTION ALSO MEANS
TEMPERATURES ALOFT ARE WARM ENOUGH TO SUPPORT MAINLY LIGHT FREEZING
RAIN AS A PRECIPITATION TYPE...WITH SLEET POTENTIALLY MIXING IN
ACROSS SOUTHWEST MINNESOTA.
MAY ALSO HAVE TO DEAL WITH FREEZING DRIZZLE LATER TONIGHT AS WELL.
LOW LEVEL LIFT BECOMES QUITE STRONG AHEAD OF THE WAVE AND LOW LEVEL
BOUNDARY...WITH THE LIFT COLLOCATED WITH A FAIRLY DEEP LAYER OF
SATURATION FROM 0 TO 1 KM. THIS SEEMS TO SUGGEST A STRONGER SIGNAL
FOR FREEZING DRIZZLE. SO EVEN IF A MAJORITY OF THE LARGE SCALE
PRECIPITATION STAYS TO OUR NORTH...STILL MAY HAVE TO WORRY ABOUT
FREEZING DRIZZLE. SO WILL PROBABLY EVENTUALLY NEED A FREEZING RAIN
ADVISORY FOR PORTIONS OF THE AREA...WITH UNTREATED SURFACES BECOMING
ICY. SOUTHERN EXTENT IS UNCERTAIN...AND SINCE MOST OF THE ISSUES
WILL NOT BE UNTIL AFTER MIDNIGHT...WILL HOLD OFF ON AN ADVISORY FOR
NOW AND LET DAY SHIFT EXAMINE NEW GUIDANCE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 334 AM CST MON FEB 9 2015
ALL 00Z MODELS HAVE TRENDED FURTHER NORTH WITH THE WAVE PASSAGE
TUESDAY MORNING. THIS INCLUDES THE ECMWF AND GEM. AT THIS TIME...OUR
FORECAST AREA IS ON THE SOUTHERN EDGE OF UPPER DIV Q FORCING...AND
THERE IS LITTLE IN THE WAY OF FRONTOGENETIC FORCING ALSO. ALL OF
THIS COUPLED WITH SOME FAIRLY DRY MID LEVELS...IT DOES NOT LOOK LIKE
A LARGE QPF EVENT ON TUESDAY. STILL...HIGH POPS ARE WARRANTED
THROUGHOUT MOST OF OUR EASTERN ZONES IN THE MORNING WITH A STRONG
POTENTIAL FOR LIGHT ICING...WITH THE SYSTEM RAPIDLY WINDING DOWN IN
THE AFTERNOON. WITH DRY MID LEVELS...WE WILL HAVE TO WATCH THE
POTENTIAL FOR FREEZING DRIZZLE...AT LEAST EAST OF THE JAMES RIVER
VALLEY IN THE MORNING. BUT FOR NOW...WENT THE MEASURABLE POPS ROUTE.
IN ADDITION WITH A WARM LAYER WELL ABOVE FREEZING FROM 850-
750MB...THERE IS LITTLE TO NO THREAT FOR SNOW IN OUR NORTHERN ZONES
TUESDAY MORNING AT THIS TIME. FOR TEMPERATURES TUESDAY...WITH
DECREASING CLOUDS FROM WEST TO EAST AND A FAVORABLE WIND DIRECTION
AHEAD OF THE NEXT MODIFIED ARCTIC FRONT COMING IN TUESDAY NIGHT...
TEMPERATURES LOOK A BIT WARMER...WITH UPPER 30S IN OUR FAR EASTERN
ZONES...AND 50S IN THE SOUTH CENTRAL SD ZONES. THIS SHOULD MELT ANY
ICE WHICH FALLS MONDAY NIGHT AND EARLY TUESDAY...BUT NOT UNTIL AFTER
THE MORNING COMMUTE.
AS MENTIONED ABOVE...THE NEXT COLD FRONT MOVES RAPIDLY INTO OUR AREA
TUESDAY NIGHT. THIS FRONT WILL DRAMATICALLY COOL OFF TEMPERATURES
AND PROVIDE WINDY CONDITIONS TUESDAY NIGHT AND WEDNESDAY. WITH
FAVORABLE TEMPERATURES ALOFT COINCIDENT WITH MOISTURE FROM 925MB-
850MB...DECIDED TO MENTION OCCASIONAL FLURRIES LATE TUESDAY NIGHT
FOR ALL BUT OUR FAR SOUTHERN ZONES WHERE LOW LEVEL MOISTURE LOOKS
TOO THIN TO SUPPORT FLURRIES. LOWS WILL BE IN THE UPPER TEENS NORTH
TO MID 20S SOUTH...AND WILL NOT RISE MUCH IF ANY ON WEDNESDAY. THIS
WILL BE FOLLOWED BY A CHILLY NIGHT WEDNESDAY NIGHT WITH LOWS IN THE
SINGLE DIGITS ABOVE ZERO...WITH SOME READINGS JUST BELOW ZERO IN OUR
NORTHERN ZONES.
ON THURSDAY...SURFACE WINDS WILL RETURN TO A SOUTHERLY DIRECTION
WITH SOME WARM AIR ADVECTION ALOFT. WOULD NOT BE SURPRISED TO SEE
SOME FLURRIES GENERALLY ALONG AND WEST OF INTERSTATE 29. BUT SO FAR
THE POTENTIAL LOOKS LIGHT ENOUGH TO NOT MENTION YET IN THE FORECAST.
OTHERWISE THE LONGER RANGE OF THE FORECAST LOOKS FAIRLY BENIGN.
STILL DOES NOT LOOK LIKE ANY BIG PRECIPITATION MAKERS FRIDAY THROUGH
SUNDAY. THERE WILL BE ANOTHER REINFORCING SHOT OF MODIFIED ARCTIC
AIR COMING DOWN FRIDAY NIGHT. THIS MAKES HIGH TEMPERATURE
FORECASTING FOR FRIDAY A BIT OF A CHALLENGE...BECAUSE IF THE FRONT
WOULD HAPPEN TO SPEED UP JUST 3 TO 6 HOURS...OUR FORECAST AREA ON
FRIDAY COULD BE A FULL TEN DEGREES COLDER. BUT RIGHT NOW MODEL
CONSENSUS SHOWS A FAIRLY DECENT DAY ON FRIDAY. ON SATURDAY... HIGHS
WILL ONCE AGAIN BE CHILLY BUT PROBABLY NOT BRUTALLY COLD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1143 AM CST MON FEB 9 2015
LOW STRATUS AND AREAS OF FOG TO LINGER THROUGH THE DAY. CIGS
LIKELY WILL NOT CHANGE MUCH INTO TONIGHT...FLUCTUATING BETWEEN
LIFR AND LOW END MVFR. BY LATE TONIGHT LIGHT FREEZING RAIN...SLEET
AND DRIZZLE SHOULD MOVE INTO THE AREA...MAINLY ALONG AND NORTH
OF INTERSTATE 90. LEFT OUT MENTION IN KSUX WHERE CHANCES ARE
LOWEST. SOUTHERLY WINDS WILL ALSO BECOME BLUSTERY
OVERNIGHT...GUSTING TO AROUND 25 KTS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...DENSE FOG ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR SDZ050-
057>059-063>065-068-069.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...MJ
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
533 AM CST MON FEB 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CST MON FEB 9 2015
EASTERLY FLOW WILL LOCK IN THE LOW LEVEL MOISTURE...RESULTING IN LOW
STRATUS LINGERING THROUGH THE DAY. PATCHY FOG IS ALSO LIKELY AT
LEAST THROUGH THE MORNING HOURS. AN AREA OF DENSE FOG HAS FORMED ON
THE EDGE OF THE STRATUS ACROSS OUR SOUTH CENTRAL SD COUNTIES. HAVE A
DENSE FOG ADVISORY THERE THROUGH 15Z. HRRR HAS A DECENT HANDLE ON
THIS AREA...AND SUGGESTS VISIBILITIES SHOULD START IMPROVING BY MID
MORNING...WITH GREGORY COUNTY THE LAST TO IMPROVE. FREEZING DRIZZLE
POTENTIAL IS STILL UNCERTAIN. LOW LEVEL MOISTURE IS PRETTY
DEEP...BUT A LACK OF A LOW LEVEL LIFTING MECHANISM IS PROBABLY
HOLDING DRIZZLE AT BAY AT THIS POINT. WILL LEAVE A MENTION IN THE
FORECAST THIS MORNING THOUGH...GIVEN THE DEEP SATURATION AND MODELS
HINTING IN A SLIGHT UPTICK IN LOW LEVEL LIFT. AT THIS TIME NOT
EXPECTING ANY DRIZZLE TO BE HEAVY ENOUGH TO CAUSE PROBLEMS...BUT DAY
SHIFT WILL HAVE TO MONITOR. GIVEN THE LOW CLOUDS...CUT BACK HIGHS
TODAY AS NOT THINKING WE WARM MUCH. SO LOOKING AT MAINLY UPPER 20S
EAST TO 30S WEST.
ATTENTION THEN TURNS TO OUR NEXT SYSTEM MOVING ACROSS THE NORTHERN
PLAINS TONIGHT...WITH PRECIPITATION MOVING EAST ACROSS THE AREA
AFTER MIDNIGHT. MODELS ARE FOCUSING IN ON A SOLUTION SLIGHTLY
FURTHER NORTH THAN THEY WERE SHOWING YESTERDAY. THIS RESULTS IN THE
BEST MID LEVEL MOISTURE AND HIGHEST QPF STAYING NORTH. STILL SEE A
DECENT PERIOD OF LIFT MOVE ACROSS OUR AREA...BUT THE DRY AIR WILL
GREATLY CUT INTO PRECIPITATION AMOUNTS. THROUGH 12Z GENERALLY
LOOKING AT LESS THAN FIVE HUNDREDTHS OF QPF...GREATEST IN THE NORTH
ALONG THE HIGHWAY 14 CORRIDOR. THE NORTHERN SOLUTION ALSO MEANS
TEMPERATURES ALOFT ARE WARM ENOUGH TO SUPPORT MAINLY LIGHT FREEZING
RAIN AS A PRECIPITATION TYPE...WITH SLEET POTENTIALLY MIXING IN
ACROSS SOUTHWEST MINNESOTA.
MAY ALSO HAVE TO DEAL WITH FREEZING DRIZZLE LATER TONIGHT AS WELL.
LOW LEVEL LIFT BECOMES QUITE STRONG AHEAD OF THE WAVE AND LOW LEVEL
BOUNDARY...WITH THE LIFT COLLOCATED WITH A FAIRLY DEEP LAYER OF
SATURATION FROM 0 TO 1 KM. THIS SEEMS TO SUGGEST A STRONGER SIGNAL
FOR FREEZING DRIZZLE. SO EVEN IF A MAJORITY OF THE LARGE SCALE
PRECIPITATION STAYS TO OUR NORTH...STILL MAY HAVE TO WORRY ABOUT
FREEZING DRIZZLE. SO WILL PROBABLY EVENTUALLY NEED A FREEZING RAIN
ADVISORY FOR PORTIONS OF THE AREA...WITH UNTREATED SURFACES BECOMING
ICY. SOUTHERN EXTENT IS UNCERTAIN...AND SINCE MOST OF THE ISSUES
WILL NOT BE UNTIL AFTER MIDNIGHT...WILL HOLD OFF ON AN ADVISORY FOR
NOW AND LET DAY SHIFT EXAMINE NEW GUIDANCE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 334 AM CST MON FEB 9 2015
ALL 00Z MODELS HAVE TRENDED FURTHER NORTH WITH THE WAVE PASSAGE
TUESDAY MORNING. THIS INCLUDES THE ECMWF AND GEM. AT THIS TIME...OUR
FORECAST AREA IS ON THE SOUTHERN EDGE OF UPPER DIV Q FORCING...AND
THERE IS LITTLE IN THE WAY OF FRONTOGENETIC FORCING ALSO. ALL OF
THIS COUPLED WITH SOME FAIRLY DRY MID LEVELS...IT DOES NOT LOOK LIKE
A LARGE QPF EVENT ON TUESDAY. STILL...HIGH POPS ARE WARRANTED
THROUGHOUT MOST OF OUR EASTERN ZONES IN THE MORNING WITH A STRONG
POTENTIAL FOR LIGHT ICING...WITH THE SYSTEM RAPIDLY WINDING DOWN IN
THE AFTERNOON. WITH DRY MID LEVELS...WE WILL HAVE TO WATCH THE
POTENTIAL FOR FREEZING DRIZZLE...AT LEAST EAST OF THE JAMES RIVER
VALLEY IN THE MORNING. BUT FOR NOW...WENT THE MEASURABLE POPS ROUTE.
IN ADDITION WITH A WARM LAYER WELL ABOVE FREEZING FROM 850-
750MB...THERE IS LITTLE TO NO THREAT FOR SNOW IN OUR NORTHERN ZONES
TUESDAY MORNING AT THIS TIME. FOR TEMPERATURES TUESDAY...WITH
DECREASING CLOUDS FROM WEST TO EAST AND A FAVORABLE WIND DIRECTION
AHEAD OF THE NEXT MODIFIED ARCTIC FRONT COMING IN TUESDAY NIGHT...
TEMPERATURES LOOK A BIT WARMER...WITH UPPER 30S IN OUR FAR EASTERN
ZONES...AND 50S IN THE SOUTH CENTRAL SD ZONES. THIS SHOULD MELT ANY
ICE WHICH FALLS MONDAY NIGHT AND EARLY TUESDAY...BUT NOT UNTIL AFTER
THE MORNING COMMUTE.
AS MENTIONED ABOVE...THE NEXT COLD FRONT MOVES RAPIDLY INTO OUR AREA
TUESDAY NIGHT. THIS FRONT WILL DRAMATICALLY COOL OFF TEMPERATURES
AND PROVIDE WINDY CONDITIONS TUESDAY NIGHT AND WEDNESDAY. WITH
FAVORABLE TEMPERATURES ALOFT COINCIDENT WITH MOISTURE FROM 925MB-
850MB...DECIDED TO MENTION OCCASIONAL FLURRIES LATE TUESDAY NIGHT
FOR ALL BUT OUR FAR SOUTHERN ZONES WHERE LOW LEVEL MOISTURE LOOKS
TOO THIN TO SUPPORT FLURRIES. LOWS WILL BE IN THE UPPER TEENS NORTH
TO MID 20S SOUTH...AND WILL NOT RISE MUCH IF ANY ON WEDNESDAY. THIS
WILL BE FOLLOWED BY A CHILLY NIGHT WEDNESDAY NIGHT WITH LOWS IN THE
SINGLE DIGITS ABOVE ZERO...WITH SOME READINGS JUST BELOW ZERO IN OUR
NORTHERN ZONES.
ON THURSDAY...SURFACE WINDS WILL RETURN TO A SOUTHERLY DIRECTION
WITH SOME WARM AIR ADVECTION ALOFT. WOULD NOT BE SURPRISED TO SEE
SOME FLURRIES GENERALLY ALONG AND WEST OF INTERSTATE 29. BUT SO FAR
THE POTENTIAL LOOKS LIGHT ENOUGH TO NOT MENTION YET IN THE FORECAST.
OTHERWISE THE LONGER RANGE OF THE FORECAST LOOKS FAIRLY BENIGN.
STILL DOES NOT LOOK LIKE ANY BIG PRECIPITATION MAKERS FRIDAY THROUGH
SUNDAY. THERE WILL BE ANOTHER REINFORCING SHOT OF MODIFIED ARCTIC
AIR COMING DOWN FRIDAY NIGHT. THIS MAKES HIGH TEMPERATURE
FORECASTING FOR FRIDAY A BIT OF A CHALLENGE...BECAUSE IF THE FRONT
WOULD HAPPEN TO SPEED UP JUST 3 TO 6 HOURS...OUR FORECAST AREA ON
FRIDAY COULD BE A FULL TEN DEGREES COLDER. BUT RIGHT NOW MODEL
CONSENSUS SHOWS A FAIRLY DECENT DAY ON FRIDAY. ON SATURDAY... HIGHS
WILL ONCE AGAIN BE CHILLY BUT PROBABLY NOT BRUTALLY COLD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 529 AM CST MON FEB 9 2015
LOW STRATUS AND AREAS OF FOG TO LINGER THROUGH THE DAY. CIGS
LIKELY WILL NOT CHANGE MUCH INTO TONIGHT...FLUCTUATING BETWEEN
LIFR AND LOW END MVFR. VISIBILITY SHOULD IMPROVE BY LATER THIS
MORNING...BUT PATCHY FOG MAY LINGER. BY LATE TONIGHT LIGHT
FREEZING RAIN AND DRIZZLE SHOULD MOVE INTO THE AREA...MAINLY NORTH
OF THE MISSOURI RIVER. SOUTHERLY WINDS WILL ALSO BECOME BLUSTERY
OVERNIGHT...GUSTING TO AROUND 25 KTS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR SDZ050-057-
063.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...MJ
AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
335 AM CST MON FEB 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CST MON FEB 9 2015
EASTERLY FLOW WILL LOCK IN THE LOW LEVEL MOISTURE...RESULTING IN LOW
STRATUS LINGERING THROUGH THE DAY. PATCHY FOG IS ALSO LIKELY AT
LEAST THROUGH THE MORNING HOURS. AN AREA OF DENSE FOG HAS FORMED ON
THE EDGE OF THE STRATUS ACROSS OUR SOUTH CENTRAL SD COUNTIES. HAVE A
DENSE FOG ADVISORY THERE THROUGH 15Z. HRRR HAS A DECENT HANDLE ON
THIS AREA...AND SUGGESTS VISIBILITIES SHOULD START IMPROVING BY MID
MORNING...WITH GREGORY COUNTY THE LAST TO IMPROVE. FREEZING DRIZZLE
POTENTIAL IS STILL UNCERTAIN. LOW LEVEL MOISTURE IS PRETTY
DEEP...BUT A LACK OF A LOW LEVEL LIFTING MECHANISM IS PROBABLY
HOLDING DRIZZLE AT BAY AT THIS POINT. WILL LEAVE A MENTION IN THE
FORECAST THIS MORNING THOUGH...GIVEN THE DEEP SATURATION AND MODELS
HINTING IN A SLIGHT UPTICK IN LOW LEVEL LIFT. AT THIS TIME NOT
EXPECTING ANY DRIZZLE TO BE HEAVY ENOUGH TO CAUSE PROBLEMS...BUT DAY
SHIFT WILL HAVE TO MONITOR. GIVEN THE LOW CLOUDS...CUT BACK HIGHS
TODAY AS NOT THINKING WE WARM MUCH. SO LOOKING AT MAINLY UPPER 20S
EAST TO 30S WEST.
ATTENTION THEN TURNS TO OUR NEXT SYSTEM MOVING ACROSS THE NORTHERN
PLAINS TONIGHT...WITH PRECIPITATION MOVING EAST ACROSS THE AREA
AFTER MIDNIGHT. MODELS ARE FOCUSING IN ON A SOLUTION SLIGHTLY
FURTHER NORTH THAN THEY WERE SHOWING YESTERDAY. THIS RESULTS IN THE
BEST MID LEVEL MOISTURE AND HIGHEST QPF STAYING NORTH. STILL SEE A
DECENT PERIOD OF LIFT MOVE ACROSS OUR AREA...BUT THE DRY AIR WILL
GREATLY CUT INTO PRECIPITATION AMOUNTS. THROUGH 12Z GENERALLY
LOOKING AT LESS THAN FIVE HUNDREDTHS OF QPF...GREATEST IN THE NORTH
ALONG THE HIGHWAY 14 CORRIDOR. THE NORTHERN SOLUTION ALSO MEANS
TEMPERATURES ALOFT ARE WARM ENOUGH TO SUPPORT MAINLY LIGHT FREEZING
RAIN AS A PRECIPITATION TYPE...WITH SLEET POTENTIALLY MIXING IN
ACROSS SOUTHWEST MINNESOTA.
MAY ALSO HAVE TO DEAL WITH FREEZING DRIZZLE LATER TONIGHT AS WELL.
LOW LEVEL LIFT BECOMES QUITE STRONG AHEAD OF THE WAVE AND LOW LEVEL
BOUNDARY...WITH THE LIFT COLLOCATED WITH A FAIRLY DEEP LAYER OF
SATURATION FROM 0 TO 1 KM. THIS SEEMS TO SUGGEST A STRONGER SIGNAL
FOR FREEZING DRIZZLE. SO EVEN IF A MAJORITY OF THE LARGE SCALE
PRECIPITATION STAYS TO OUR NORTH...STILL MAY HAVE TO WORRY ABOUT
FREEZING DRIZZLE. SO WILL PROBABLY EVENTUALLY NEED A FREEZING RAIN
ADVISORY FOR PORTIONS OF THE AREA...WITH UNTREATED SURFACES BECOMING
ICY. SOUTHERN EXTENT IS UNCERTAIN...AND SINCE MOST OF THE ISSUES
WILL NOT BE UNTIL AFTER MIDNIGHT...WILL HOLD OFF ON AN ADVISORY FOR
NOW AND LET DAY SHIFT EXAMINE NEW GUIDANCE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 334 AM CST MON FEB 9 2015
ALL 00Z MODELS HAVE TRENDED FURTHER NORTH WITH THE WAVE PASSAGE
TUESDAY MORNING. THIS INCLUDES THE ECMWF AND GEM. AT THIS TIME...OUR
FORECAST AREA IS ON THE SOUTHERN EDGE OF UPPER DIV Q FORCING...AND
THERE IS LITTLE IN THE WAY OF FRONTOGENETIC FORCING ALSO. ALL OF
THIS COUPLED WITH SOME FAIRLY DRY MID LEVELS...IT DOES NOT LOOK LIKE
A LARGE QPF EVENT ON TUESDAY. STILL...HIGH POPS ARE WARRANTED
THROUGHOUT MOST OF OUR EASTERN ZONES IN THE MORNING WITH A STRONG
POTENTIAL FOR LIGHT ICING...WITH THE SYSTEM RAPIDLY WINDING DOWN IN
THE AFTERNOON. WITH DRY MID LEVELS...WE WILL HAVE TO WATCH THE
POTENTIAL FOR FREEZING DRIZZLE...AT LEAST EAST OF THE JAMES RIVER
VALLEY IN THE MORNING. BUT FOR NOW...WENT THE MEASURABLE POPS ROUTE.
IN ADDITION WITH A WARM LAYER WELL ABOVE FREEZING FROM 850-
750MB...THERE IS LITTLE TO NO THREAT FOR SNOW IN OUR NORTHERN ZONES
TUESDAY MORNING AT THIS TIME. FOR TEMPERATURES TUESDAY...WITH
DECREASING CLOUDS FROM WEST TO EAST AND A FAVORABLE WIND DIRECTION
AHEAD OF THE NEXT MODIFIED ARCTIC FRONT COMING IN TUESDAY NIGHT...
TEMPERATURES LOOK A BIT WARMER...WITH UPPER 30S IN OUR FAR EASTERN
ZONES...AND 50S IN THE SOUTH CENTRAL SD ZONES. THIS SHOULD MELT ANY
ICE WHICH FALLS MONDAY NIGHT AND EARLY TUESDAY...BUT NOT UNTIL AFTER
THE MORNING COMMUTE.
AS MENTIONED ABOVE...THE NEXT COLD FRONT MOVES RAPIDLY INTO OUR AREA
TUESDAY NIGHT. THIS FRONT WILL DRAMATICALLY COOL OFF TEMPERATURES
AND PROVIDE WINDY CONDITIONS TUESDAY NIGHT AND WEDNESDAY. WITH
FAVORABLE TEMPERATURES ALOFT COINCIDENT WITH MOISTURE FROM 925MB-
850MB...DECIDED TO MENTION OCCASIONAL FLURRIES LATE TUESDAY NIGHT
FOR ALL BUT OUR FAR SOUTHERN ZONES WHERE LOW LEVEL MOISTURE LOOKS
TOO THIN TO SUPPORT FLURRIES. LOWS WILL BE IN THE UPPER TEENS NORTH
TO MID 20S SOUTH...AND WILL NOT RISE MUCH IF ANY ON WEDNESDAY. THIS
WILL BE FOLLOWED BY A CHILLY NIGHT WEDNESDAY NIGHT WITH LOWS IN THE
SINGLE DIGITS ABOVE ZERO...WITH SOME READINGS JUST BELOW ZERO IN OUR
NORTHERN ZONES.
ON THURSDAY...SURFACE WINDS WILL RETURN TO A SOUTHERLY DIRECTION
WITH SOME WARM AIR ADVECTION ALOFT. WOULD NOT BE SURPRISED TO SEE
SOME FLURRIES GENERALLY ALONG AND WEST OF INTERSTATE 29. BUT SO FAR
THE POTENTIAL LOOKS LIGHT ENOUGH TO NOT MENTION YET IN THE FORECAST.
OTHERWISE THE LONGER RANGE OF THE FORECAST LOOKS FAIRLY BENIGN.
STILL DOES NOT LOOK LIKE ANY BIG PRECIPITATION MAKERS FRIDAY THROUGH
SUNDAY. THERE WILL BE ANOTHER REINFORCING SHOT OF MODIFIED ARCTIC
AIR COMING DOWN FRIDAY NIGHT. THIS MAKES HIGH TEMPERATURE
FORECASTING FOR FRIDAY A BIT OF A CHALLENGE...BECAUSE IF THE FRONT
WOULD HAPPEN TO SPEED UP JUST 3 TO 6 HOURS...OUR FORECAST AREA ON
FRIDAY COULD BE A FULL TEN DEGREES COLDER. BUT RIGHT NOW MODEL
CONSENSUS SHOWS A FAIRLY DECENT DAY ON FRIDAY. ON SATURDAY... HIGHS
WILL ONCE AGAIN BE CHILLY BUT PROBABLY NOT BRUTALLY COLD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1129 PM CST SUN FEB 8 2015
LOW CEILINGS AND FOG WILL REMAIN PRIMARY AVIATION CONCERN THROUGH
THE TAF PERIOD. CEILINGS GENERALLY MVFR-IFR RANGE...BUT LOCALIZED
LIFR CONDITIONS LIKELY THROUGH MIDDAY MONDAY. LOWEST CONDITIONS ARE
EXPECTED TO AFFECT HIGHER ELEVATIONS IN SOUTHWEST MN...AS WELL AS
LOCATIONS WEST OF THE JAMES RIVER VALLEY. POTENTIAL FOR SOME SPOTTY
LIGHT FREEZING DRIZZLE THROUGH THE FIRST HALF OF THE TAF PERIOD...
WITH LOWER CEILINGS AND MVFR-IFR VISIBILITY. OPTED TO INCLUDE BRIEF
PERIOD OF THIS FOR KHON/KFSD TAFS DUE TO IMPACT FROM EVEN MINIMAL
ICING...ESPECIALLY DURING 08Z-12Z WINDOW WHEN THE MORNING FLIGHTS
ARE BEING PREPPED.
SLOW IMPROVEMENT IN CEILINGS/VISIBILITY THROUGHOUT THE DAY MONDAY...
WITH VISIBILITY EXPECTED TO BECOME VFR...BUT CEILINGS MORE LIKELY TO
REMAIN IN MVFR RANGE THROUGH THE END OF THE TAF PERIOD. POTENTIAL
FOR ANOTHER ICING EVENT TO AFFECT PARTS OF THE FORECAST AREA MONDAY
NIGHT...BUT PRECIPITATION CURRENTLY LOOKS TO HOLD OFF UNTIL AFTER
10/06Z.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR SDZ050-057-
063.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...MJ
AVIATION...JH
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1134 AM CST MON FEB 9 2015
.AVIATION 18Z DISCUSSION...
SHORTWAVE AXIS WILL WORK ACROSS THE MID STATE THIS AFTERNOON.
IMPULSES UPSTREAM WILL PIVOT ACROSS THE AREA TONIGHT. SOME LIGHT
PRECIP WILL PERSIST THROUGH MUCH OF THE TAF PD...MAINLY ACROSS THE
CSV AREA. SOME LIGHT MIXED PRECIPITATION WILL BE POSSIBLE AFT
06Z. NVA WILL WIN OUT BY 12Z WITH SOME PARTIAL CLEARING THEREAFTER.
&&
.PREV DISCUSSION... /ISSUED 1031 AM CST MON FEB 9 2015/
DISCUSSION UPDATE...
LOW LEVEL MOISTURE TO PREVAIL THROUGH THE DAY. SHORTWAVE TROUGH
AXIS WILL REACH THE PLATEAU AROUND 18Z. WE ARE STILL SEEING SOME
WEAK PVA ON THE BACK SIDE OF THE TROUGH...AND THAT WILL BE IN PLAY
THROUGH THIS EVENING. THUS...DESPITE THE FACT THAT THE HRRR IS
BACKING OFF ON THE PRECIP ONCE WE GET PAST 18Z THIS EVENING...WILL
ELECT TO KEEP THE WEATHER GRIDS AS IS. FURTHERMORE...LOW LEVEL
CONDENSATION PRESSURE DEFICITS WILL REMAIN ELEVATED.
AS FOR TEMPERATURES...WITH THE CAA AND CLOUDINESS REMAINING IN
PLACE...TEMPS WILL STRUGGLE TO WARM TODAY. IN FACT...CAA AT THE
850 MB LEVEL WILL REALLY KICK IN AFT 18Z. WILL THEREFORE RUN THE
SERP TOOL AND START CUTTING MAX TEMPS FOR TODAY.
UPDATE OUT SHORTLY.
PREV DISCUSSION... /ISSUED 531 AM CST MON FEB 9 2015/
AVIATION...
EXPECT LOW CIGS TO PERSIST THROUGH MOST OF THE TAF PERIOD...WITH
ALL THREE SITES SEEING MVFR CIGS WITH IFR POSSIBLE AT CSV. WINDS
WILL GRADUALLY SHIFT TO THE NORTH AS A FRONT PUSHES THROUGH THE
AREA EARLY...WITH LIGHT PRECIPITATION ENDING AS THE FRONT PASSES.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1031 AM CST MON FEB 9 2015
.DISCUSSION UPDATE...
LOW LEVEL MOISTURE TO PREVAIL THROUGH THE DAY. SHORTWAVE TROUGH
AXIS WILL REACH THE PLATEAU AROUND 18Z. WE ARE STILL SEEING SOME
WEAK PVA ON THE BACK SIDE OF THE TROUGH...AND THAT WILL BE IN PLAY
THROUGH THIS EVENING. THUS...DESPITE THE FACT THAT THE HRRR IS
BACKING OFF ON THE PRECIP ONCE WE GET PAST 18Z THIS EVENING...WILL
ELECT TO KEEP THE WEATHER GRIDS AS IS. FURTHERMORE...LOW LEVEL
CONDENSATION PRESSURE DEFICITS WILL REMAIN ELEVATED.
AS FOR TEMPERATURES...WITH THE CAA AND CLOUDINESS REMAINING IN
PLACE...TEMPS WILL STRUGGLE TO WARM TODAY. IN FACT...CAA AT THE
850 MB LEVEL WILL REALLY KICK IN AFT 18Z. WILL THEREFORE RUN THE
SERP TOOL AND START CUTTING MAX TEMPS FOR TODAY.
UPDATE OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 531 AM CST MON FEB 9 2015/
AVIATION...
EXPECT LOW CIGS TO PERSIST THROUGH MOST OF THE TAF PERIOD...WITH
ALL THREE SITES SEEING MVFR CIGS WITH IFR POSSIBLE AT CSV. WINDS
WILL GRADUALLY SHIFT TO THE NORTH AS A FRONT PUSHES THROUGH THE
AREA EARLY...WITH LIGHT PRECIPITATION ENDING AS THE FRONT PASSES.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
914 PM CST TUE FEB 10 2015
.UPDATE...
THE BANDS OF SNOW/ISOLATED SLEET HAD A HARD TIME REACHING THE
GROUND DUE TO THE INITIAL DRY LOW LEVEL AIR. LATEST RAP SOUNDINGS
SHOW MOISTENING HAS OCCURRED OVER MUCH OF THE FORECAST AREA
EXCEPT FOR THE FAR EAST...WHICH WILL OCCUR SHORTLY. ACROSS THE FAR
NORTH THERE WAS SOME SNOW REACHING THE GROUND MAINLY ACROSS
MARQUETTE/GREEN LAKE AND NORTHERN PORTIONS OF FOND DU LAC AND
SHEBOYGAN COUNTIES. AREAS JUST TO THE NORTH PICKED UP A QUICK
INCH AND SOME ACCUMULATING SNOW OCCURED IN THE FAR NORTH BORDER
AREA OF THE FORECAST AREA.
NOW WITH MOISTENING THE HRRR SHOWS MORE PRECIPITATION WITH THE
SURFACE TROUGH...AGAIN MAINLY IN NORTH AREAS. THIS WOULD BE LIGHT.
THEN THERE MAY BE SOME PATCHY DRIZZLE IN THE AREAS WITH LOW
STRATUS BEHIND THE TROUGH.
&&
.AVIATION/06Z TAFS/...
VFR/MVFR CEILINGS SHOULD DROP TO MVFR/IFR FROM THE WEST
OVERNIGHT...AND REMAIN MVFR CATEGORY ON WEDNESDAY. LIGHT SNOW
SHOWERS AND FLURRIES WILL AFFECT TAF SITES AT TIMES LATER TONIGHT
INTO WEDNESDAY.
WINDS WILL GRADUALLY VEER SOUTHWEST TO WEST LATER TONIGHT. WINDS
WILL BECOME NORTHWEST AFTER STRONG COLD FRONTAL PASSAGE BETWEEN
12Z AND 15Z WEDNESDAY. NORTHWESTERLY GUSTS TO 25 KNOTS ARE
EXPECTED IN THE AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 336 PM CST TUE FEB 10 2015/
TONIGHT AND WEDNESDAY...FORECAST CONFIDENCE IS MEDIUM.
STRONG 500 MB SHORTWAVE TROUGH IS EXPECTED TO SLIDE EAST NORTHEAST
ACROSS THE REGION INTO THIS EVENING...WITH ANOTHER SLIDING SOUTHEAST
INTO THE AREA AROUND 12Z WEDNESDAY. BEST UPWARD VERTICAL MOTION FROM
THE FIRST SHORTWAVE...ALONG WITH FOCUSED WARM AIR ADVECTION AND 850
MB TO 700 MB Q VECTOR CONVERGENCE...REMAINS OVER NORTHERN AND
CENTRAL WISCONSIN. THIS DOES BRUSH THE FAR NORTHERN COUNTIES.
LATEST MESOSCALE MODELS ARE IN GENERAL AGREEMENT WITH SHOWING A BAND
OF MAINLY LIGHT SNOW SHOWERS/FLURRIES SLIDING EAST ACROSS THE AREA
THROUGH THE EARLY EVENING HOURS...WITH LIGHTER REFLECTIVITIES IN ITS
WAKE FOR LATER THIS EVENING AND OVERNIGHT. A FAIR AMOUNT OF DRY AIR
IN THE LOW LEVELS HAS RESULTED IN LITTLE TO NO PRECIPITATION BEING
OBSERVED BY UPSTREAM OBSERVATION SITES.
THINK THAT THERE SHOULD BE SCATTERED TO NUMEROUS LIGHT SNOW SHOWERS
AT BEST WITH THIS BAND...SO USED THAT WORDING IN THE FORECAST FOR
TONIGHT. SOME UNCERTAINTY HERE WITH AREAL COVERAGE GIVEN THE DRY LOW
LEVELS.
AREA FORECAST SOUNDINGS FROM NAM/GFS/RAP/HRRR GENERALLY SHOW MAINLY
LIGHT SNOW WHERE DEEP SATURATION IN AIR COLUMN OCCURS. THE INITIAL
BAND OF REFLECTIVITY MAY ALSO CONTAIN PATCHY LIGHT FREEZING
DRIZZLE...AS ICE CRYSTALS MAY NOT BE INTRODUCED INTO AIR COLUMN AT
TIMES. SOUNDINGS LATER THIS EVENING AND OVERNIGHT SHOWING PATCHY
LIGHT FREEZING DRIZZLE CONTINUING...WITH LOSS OF ICE CRYSTALS.
FOR TONIGHT...CONTINUED HIGHEST POPS IN THE FAR NORTH...LOWER TO THE
SOUTH TONIGHT. AROUND 1 INCH OF SNOW ACCUMULATION IS EXPECTED FAR
NORTH...TO A DUSTING AT BEST FAR SOUTH.
AREA REMAINS IN CYCLONIC FLOW AT 500 MB WEDNESDAY...WITH STRONG
VORTICITY MAXIMUM SHIFTING TOWARD THE AREA LATER IN THE DAY. AREA
FORECAST SOUNDINGS SUPPORT ISOLATED TO SCATTERED LIGHT SNOW SHOWER
ACTIVITY WITH MOIST LOW LEVELS AND STEEP LOW LEVEL LAPSE RATES IN
DENDRITE SNOW GROWTH ZONE. NORTHWEST WINDS BEHIND STRONG COLD FRONT
WILL BECOME GUSTY ON WEDNESDAY...GUSTING UP TO 25 KNOTS IN THE
AFTERNOON.
TEMPERATURES WILL REMAIN NEARLY STEADY TONIGHT WITH THE WARM AIR
ADVECTION...THEN WILL HAVE EARLY HIGHS ON WEDNESDAY BEFORE STRONG
COLD FRONT MOVES THROUGH. TEMPERATURES WILL THEN GRADUALLY FALL WITH
THE COLD AIR ADVECTION KICKING IN DURING THE DAY.
WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE IS HIGH.
A DEEP 500MB TROUGH DIVES SOUTH THROUGH THE STATE OVERNIGHT. A
STRONG VORTICITY MAXIMUM MOVES THROUGH WITH THE TROUGH AXIS SO HAVE
LIGHT SNOW OVERNIGHT. GUSTY NORTHWEST WINDS WILL CONTINUE THRU THURS
MORNING AND WILL START TO WIND DOWN DURING THE AFTERNOON AS SURFACE
HIGH PRESSURE MOVES INTO THE REGION. STRONG COLD AIR ADVECTION
BRINGS 925 TEMPERATURES TO AROUND -20C YIELDING HIGHS IN THE SINGLE
DIGITS. THURSDAY MORNING WIND CHILL VALUES LOOK TO BE AROUND -15
DEGREES.
THURSDAY NIGHT THRU FRIDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM.
WARM AIR ADVECTION FOLLOWING A THERMAL RIDGE KEEPS TEMPS FROM
DROPPING MUCH THURSDAY NIGHT FROM THE CHILLY DAYTIME HIGHS AND
BRINGS SOME MODERATION TO TEMPS ON FRI. THE NEXT LOW MOVES NORTH OF
THE STATE ON FRIDAY WITH A CHANCE FOR LIGHT SNOW ALONG THE SURFACE
TROUGH. COULD SEE ABOUT A HALF INCH OF ACCUMULATION.
SATURDAY THRU SUNDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
ANOTHER DEEP 500MB TROUGH DIGS SOUTH ACROSS THE STATE ON SATURDAY
BRINGING ANOTHER SURGE OF COLD AIR AND GUSTY NORTHWEST WINDS. 925
TEMPS GET DOWN TO -23C. THE COLDEST SURFACE TEMPERATURES DURING THE
EXTENDED PERIOD WILL BE SATURDAY NIGHT WHERE TEMPS OF -10 TO -15 ARE
FORECAST AWAY FROM THE LAKE. THIS IS A TIME PERIOD TO MONITOR FOR A
WIND CHILL ADVISORY. WINDS WILL BE WINDING DOWN OVERNIGHT AHEAD OF
HIGH PRESSURE BUILDING INTO THE REGION ON SUNDAY...BUT LIGHT WINDS
WILL BE ENOUGH TO CREATE WIND CHILL VALUES OF -20 TO -25 SUNDAY
MORNING.
A SHORTWAVE MOVES ACROSS THE REGION SUNDAY NIGHT BRINGING ANOTHER
CHANCE FOR LIGHT SNOW.
MONDAY AND TUESDAY...FORECAST CONFIDENCE IS LOW.
500MB FLOW BECOMES LESS AMPLIFIED ON MONDAY AND A PAIR OF SHORTWAVES
MOVE THROUGH. THE ECMWF CONTINUES TO INDICATE LIGHT SNOW ALONG A
FRONTAL BOUNDARY WHILE THE GFS IS MUCH DRIER. MODEL CONSENSUS OF
POPS RESULTS IN A CHANCE FOR LIGHT SNOW.
AVIATION/00Z TAFS/...
BAND OF LIGHT SNOW SHOWERS/FLURRIES WILL MOVE EAST THROUGH TAF SITES
THROUGH EARLY THIS EVENING. SOME UNCERTAINTY WITH AREAL COVERAGE
GIVEN THE DRY AIR IN LOW LEVELS OF ATMOSPHERE. IT SHOULD AFFECT
MADISON FROM 22Z TUESDAY TO 00Z WEDNESDAY...AND THE EASTERN SITES
BETWEEN 23Z TUESDAY AND 02Z WEDNESDAY.
0.1 TO 0.2 INCHES OF SNOW AT MOST WOULD BE EXPECTED...BUT CONFIDENCE
IS LOW WITH THIS. KEPT MAINLY VFR CONDITIONS GOING WITH THIS LIGHT
SNOW SHOWER BAND...AS AM NOT SEEING MUCH IN THE WAY OF VISIBILITY
RESTRICTIONS UPSTREAM.
VFR/MVFR CEILINGS SHOULD DROP TO 600 TO 1000 FEET ABOVE GROUND LEVEL
BY LATER THIS EVENING AND OVERNIGHT...AND REMAIN MVFR CATEGORY ON
WEDNESDAY. LIGHT SNOW SHOWERS AND FLURRIES WILL AFFECT TAF SITES AT
TIMES LATER TONIGHT INTO WEDNESDAY...BUT WILL LEAVE OUT OF TAFS DUE
TO LOW CONFIDENCE IN TIMING AND AREAL COVERAGE.
WINDS WILL GRADUALLY VEER SOUTH BY THIS EVENING...THEN SOUTHWEST TO
WEST LATER TONIGHT. WINDS WILL BECOME NORTHWEST AFTER STRONG COLD
FRONTAL PASSAGE BETWEEN 12Z AND 15Z WEDNESDAY. NORTHWESTERLY GUSTS
TO 25 KNOTS ARE EXPECTED IN THE AFTERNOON.
MARINE...
A STRONG PRESSURE GRADIENT WILL DEVELOP AFTER A STRONG COLD FRONTAL
PASSAGE EARLY WEDNESDAY MORNING. GUSTY NORTHWEST WINDS WILL
RESULT...LINGERING THROUGH THURSDAY. GUSTS TO 30 KNOTS ARE EXPECTED
LATER WEDNESDAY MORNING INTO WEDNESDAY EVENING...SO A SMALL CRAFT
ADVISORY WILL BE ISSUED FOR THIS PERIOD. WAVES WILL BECOME HIGH AS
WELL...HIGHEST TOWARD THE OPEN WATERS.
NORTHWEST GUSTS TO 35 KNOT GALES ARE EXPECTED LATER WEDNESDAY NIGHT
INTO THURSDAY MORNING...AND ASSOCIATED HIGH WAVES SHOULD BRING HEAVY
FREEZING SPRAY. THUS...A GALE WARNING AND HEAVY FREEZING SPRAY
WARNING WILL BE ISSUED FOR THIS PERIOD. WINDS AND WAVES WILL
SUBSIDE LATER THURSDAY INTO THURSDAY NIGHT...WHERE MORE SMALL CRAFT
ADVISORIES WILL BE NEEDED.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...HEAVY FREEZING SPRAY WARNING FROM MIDNIGHT WEDNESDAY NIGHT TO
NOON CST THURSDAY FOR LMZ643>646.
SMALL CRAFT ADVISORY FROM 9 AM WEDNESDAY TO MIDNIGHT CST
WEDNESDAY NIGHT FOR LMZ643>646.
GALE WARNING FROM MIDNIGHT WEDNESDAY NIGHT TO NOON CST THURSDAY
FOR LMZ643>646.
&&
$$
UPDATE...HENTZ
TONIGHT/WEDNESDAY AND AVIATION/MARINE...WOOD
WEDNESDAY NIGHT THROUGH TUESDAY...MARQUARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1121 AM CST MON FEB 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 319 AM CST MON FEB 9 2015
HIGHLIGHTS/CONCERNS
1. CAN CLOUDS CLEAR TODAY...AND WHERE.
CURRENTLY AS OF 09Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A POTENT UPPER TROUGH ALONG THE U.S. WEST COAST...RIDGING
FROM THE DESERT SOUTHWEST INTO ALBERTA...AND GENERAL TROUGHING OVER
THE EASTERN U.S.. A WEAK SHORTWAVE WAS ALSO EVIDENT OVER NORTHERN
MN. THIS SHORTWAVE WAS PRODUCING JUST SOME HIGH CLOUDS. THOSE CLOUDS
WERE OVER TOP OF AN EXPANSIVE STRATUS DECK...STRETCHING FROM NORTH
DAKOTA INTO MUCH OF MN...IA AND A LOT OF WI. HOWEVER...CLEARING WAS
EVIDENT ACROSS NORTHEAST WI MARCHING SOUTHWESTWARD...RESULTING FROM
A NORTHEAST LOW LEVEL FLOW BRINGING IN DRIER AIR FROM EASTERN
ONTARIO. THE CLOUDS HAVE HELPED TO HOLD TEMPERATURES UP INTO THE
UPPER TEENS TO MID 20S...DESPITE A COLD ADVECTION PATTERN IN PLACE.
925MB TEMPS RANGED FROM -7 TO -11C PER RAP ANALYSIS.
MUCH OF THE NEXT 24 HOURS IS RELATIVELY QUIET. UPPER RIDGING OVER
THE WESTERN U.S. IS PROGGED TO FLATTEN OUT AND GET PUSHED EASTWARD
INTO THE FORECAST AREA TONIGHT...IN RESPONSE TO THE POTENT TROUGH
ALONG THE WEST COAST BREAKING APART AND MOVING INTO THE DAKOTAS BY
12Z TUESDAY. SUBSIDENCE ASSOCIATED WITH THE UPPER RIDGING SHOULD
HELP KEEP CONDITIONS DRY. THE MAIN CONCERN REVOLVES AROUND THE
CURRENT STRATUS DECK AND POTENTIAL FOR CLEARING. LOOKING AT THE 925-
850MB WIND FLOW...TO SEE IF THAT CLEARING IN NORTHEAST WI CAN MAKE
IT INTO THE FORECAST AREA...THAT FLOW IS PROGGED TO WEAKEN AND BACK
MORE NORTHERLY THROUGH THE DAY. WE WILL HAVE DAYTIME HEATING TO HELP
MIX SOME...SO IT WOULD SEEM THAT THE EAST HALF OF THE FORECAST AREA
WOULD STAND TO HAVE THE BEST CHANCE TO SCATTER/CLEAR OUT. FROM THE
MISSISSIPPI RIVER WEST...IT COULD EASILY STAY CLOUDY ALL DAY AND
INTO TONIGHT. GIVEN THE EXPECTED CLOUD TRENDS AND 925MB TEMPS ONLY
FORECAST TO WARM MAYBE 1C TODAY...TEMPERATURES ARE GOING TO STRUGGLE
TO CLIMB. MAYBE WE GET A 5 DEGREE RISE. LOWS TONIGHT WILL BE COLDEST
TOWARDS CENTRAL WI WITH THE BEST CHANCE TO HAVE CLEAR SKIES AND
LIGHT WINDS. COULD SEE POTENTIAL FOR SINGLE DIGIT LOWS WHERE IT
CLEARS OUT. OTHERWISE MORE TEENS TO LOW 20S SEEMS REASONABLE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 319 AM CST MON FEB 9 2015
HIGHLIGHTS/CONCERNS...
1. PRECIPITATION CHANCES/AMOUNTS/TYPE TUESDAY-TUESDAY NIGHT
2. WINDS/BLOWING SNOW POTENTIAL WEDNESDAY-WEDNESDAY NIGHT
3. WIND CHILLS THURSDAY MORNING
4. ANOTHER ARCTIC BLAST LOOKING MORE LIKELY FOR SATURDAY
THE SHORTWAVE TROUGH OVER THE DAKOTAS AT 12Z TUESDAY IS PROGGED TO
MOVE THROUGH THE FORECAST AREA TUESDAY EVENING...WITH YET A SECOND
SHORTWAVE TROUGH COMING THROUGH AFTER MIDNIGHT TUESDAY NIGHT. DPVA
FROM BOTH TROUGHS COMBINED WITH DECENT ISENTROPIC LIFT...ESPECIALLY
FROM THE FIRST ONE...WILL BRING PRECIPITATION TO THE FORECAST AREA.
BEST JUXTAPOSITION OF MOISTURE WITH FORCING REMAINS NORTH OF I-90
AND GIVEN VERY GOOD RUN TO RUN CONSISTENCY...HAVE CONTINUED TO
INCREASE PRECIPITATION CHANCES. IT SHOULD BE NOTED THAT A BREAK IN
PRECIPITATION IS LIKELY BETWEEN THE 2 SHORTWAVES...MOST PROBABLE
DURING TUESDAY AFTERNOON AND EVENING SOUTH OF HIGHWAY 10. TRIED TO
CONVEY THIS IN THE GRIDDED FORECAST. THE PRECIPITATION TYPE REMAINS
PROBLEMATIC. NORTH OF I-90 CONFIDENCE IS FAIRLY HIGH FOR SNOW WITH
NO ISSUES OF A WARM LAYER OR LOSING ICE IN THE CLOUD. SOUTH OF I-90
BOTH OF THOSE ISSUES EXIST...BUT AT THE SAME TIME THERE MAY NOT BE
MUCH PRECIPITATION SOUTH OF I-90. THUS...THE AMOUNT OF ANY SLEET OR
FREEZING RAIN/DRIZZLE IS EXTREMELY UNCERTAIN. REGARDING SNOWFALL
AMOUNTS...GIVEN THE DENDRITIC GROWTH ZONE IS UP HIGH AND
THIN...ANTICIPATING SNOW TO WATER RATIOS AROUND 10 TO 1. WITH GOOD
MODEL CONSENSUS FOR 24 HOUR QPF AMOUNTS IN THE 0.2-0.3 INCH RANGE
WHERE SNOW IS THE MAIN P-TYPE...SHOULD BE LOOKING AT 2-3 INCHES OF
SNOWFALL. HIGHEST AMOUNTS WOULD OCCUR IN TAYLOR COUNTY. WINTER
WEATHER ADVISORIES ARE POSSIBLE...ESPECIALLY IF CONFIDENCE GROWS FOR
SOME FREEZING RAIN TO OCCUR.
ATTENTION THEN TURNS TO A VERY POTENT SHORTWAVE TROUGH...CURRENTLY
COMING OFF THE ARCTIC OCEAN INTO THE NORTHWEST TERRITORIES OF
CANADA...PROGGED TO DROP THROUGH THE REGION LATE WEDNESDAY INTO
WEDNESDAY NIGHT. PRECIPITATION WILL BE HARD TO COME BY FOR THE
TROUGH BECAUSE OF THE MOISTURE BEING SHUNTED AWAY BY THE
TUESDAY/TUESDAY NIGHT SYSTEM. HOWEVER...THERE COULD BE SOME
INSTABILITY INDUCED SNOW SHOWERS PRODUCED WEDNESDAY NIGHT AS THE
TROUGH COMES THROUGH. MORE SIGNIFICANTLY...THE TROUGH BRINGS IN AN
INCREASE IN WINDS AND ARCTIC AIR. NORTHWEST 925MB WINDS INCREASE TO
30 TO 40 KT DURING THE AFTERNOON AND EVENING...CAUSING THE
ASSOCIATED TEMPS TO PLUMMET FROM -8 TO -12C AT 18Z WED TO -20 TO
-25C AT 12Z THU. THOSE 12Z THU READINGS ARE COLDER THAN BEFORE
AND THUS HAVE HAD TO LOWER LOWS A FEW DEGREES WEDNESDAY NIGHT.
THESE LOWS COMBINED WITH THE WINDS ARE MAKING A WIND CHILL
ADVISORY LOOK MORE LIKELY WEST OF THE MS RIVER AND OVER NORTH
CENTRAL WI. ADDITIONALLY...WITH MODEL SOUNDINGS DEPICTING MIXING
TO 850- 900MB...30 KT GUSTS SEEM EASILY POSSIBLE. THESE GUSTS WILL
CAUSE ANY SNOW FROM TUESDAY...TUESDAY NIGHT AND WEDNESDAY NIGHT TO
BLOW AROUND. THEREFORE...ADDED SOME PATCHY BLOWING SNOW TO THE
FORECAST.
THE ARCTIC AIR LOOKS TO LINGER OVER THE AREA ON THURSDAY SO LOWERED
HIGHS A FEW DEGREES. HOWEVER...BRIEF UPPER RIDGING THEN COMES
SOUTHEAST OVER THE AREA FOR THURSDAY NIGHT INTO FRIDAY TO BRING IN
WARMER AIR. 925MB TEMPS CLIMB TO -7 TO -12C BY 00Z SAT ACCORDING TO
THE 09.00Z EC/GFS. SOME LIGHT SNOW COULD ACCOMPANY THIS WARMER AIR
FOR FRIDAY.
ANOTHER ARCTIC BLAST THEN LOOKS TO AFFECT THE REGION FOR SATURDAY...
CAUSED BY A VERY POTENT SHORTWAVE TROUGH PROGGED TO DROP DOWN INTO
THE WESTERN GREAT LAKES. THIS TROUGH IS CURRENTLY OVER THE ARCTIC
OCEAN JUST NORTH OF EASTERN SIBERIA...A GREAT SOURCE REGION FOR VERY
COLD AIR. 850MB TEMPERATURE STANDARDIZED ANOMALIES FALL TO -2 TO
-2.5 ON SATURDAY PER THE 09.00Z EC/GFS...AND AS SUCH THE MEX
GUIDANCE AND ECMWF MAX T GUIDANCE ONLY HAVE HIGHS IN THE SINGLE
DIGITS. ACCOMPANYING THIS SHORTWAVE TROUGH IS ALSO A STRONG SURGE OF
WIND SO WE COULD BE DEALING WITH MORE WIND CHILL ISSUES. FOR NOW
FOLLOWED A CONSENSUS BLEND OF ALL GUIDANCE...WHICH IS WEAKER ON
WINDS AND WARMER ON TEMPERATURES. HOWEVER...WINDS MAY NEED TO BE
INCREASED ALONG WITH TEMPERATURES LOWERED OVER THE NEXT FEW DAYS IF
MODELS CONTINUE TO PROG THE TROUGH GOING THROUGH THE WESTERN GREAT
LAKES.
WE SHOULD SEE SOME MODIFICATION OF THE ARCTIC AIR FOR SUNDAY AND
MONDAY AS THE POTENT TROUGH DIGS AND HEADS OFF THE U.S. EAST COAST.
SIMILAR TO FRIDAY...MAY SEE A LITTLE LIGHT SNOW WITH THE WARM
ADVECTION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1120 AM CST MON FEB 9 2015
EXTENSIVE FIELD OF VFR STRATOCUMULUS PRESENTLY ACROSS THE
AREA...BUT VISIBLE/IR SATELLITE IMAGERY SHOW A SLOW EROSION FROM
NORTH TO SOUTH AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION.
VFR CONDITIONS EXPECTED TO CONTINUE THROUGH TONIGHT WITH AN
INCREASE IN MID-LEVEL //BASES AOA 10KFT// CLOUD AFTER 09Z AHEAD OF
A FAIRLY VIGOROUS AREA OF LOW PRESSURE MOVING THROUGH THE
NORTHERN PLAINS. EXPECTING LIGHT SNOW TO BREAK OUT AT KRST AROUND
15Z AND AT KLSE TOWARD THE END OF THE TAF PERIOD/17Z-ISH. APPEARS
VSBY AT KRST WILL DETERIORATE INTO IFR CATEGORY WITH THE ONSET OF
THE SNOW WHILE KLSE MAINTAINS VFR IN THE 17-18Z TIME FRAME.
APPEARS IFR CONDITIONS WILL LINGER AT KRST THROUGH THE REST OF
TUESDAY WITH SOME FZDZ POSSIBLE THROUGH THE AFTERNOON. KLSE
APPEARS TO REMAIN MVFR WITH FZDZ ALSO POSSIBLE THROUGH THE
AFTERNOON HOURS. WILL LET EVENING FORECASTER HONE IN ON DETAILS
WITH THE 10.00Z TAF ISSUANCE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
544 AM CST MON FEB 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 319 AM CST MON FEB 9 2015
HIGHLIGHTS/CONCERNS
1. CAN CLOUDS CLEAR TODAY...AND WHERE.
CURRENTLY AS OF 09Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A POTENT UPPER TROUGH ALONG THE U.S. WEST COAST...RIDGING
FROM THE DESERT SOUTHWEST INTO ALBERTA...AND GENERAL TROUGHING OVER
THE EASTERN U.S.. A WEAK SHORTWAVE WAS ALSO EVIDENT OVER NORTHERN
MN. THIS SHORTWAVE WAS PRODUCING JUST SOME HIGH CLOUDS. THOSE CLOUDS
WERE OVER TOP OF AN EXPANSIVE STRATUS DECK...STRETCHING FROM NORTH
DAKOTA INTO MUCH OF MN...IA AND A LOT OF WI. HOWEVER...CLEARING WAS
EVIDENT ACROSS NORTHEAST WI MARCHING SOUTHWESTWARD...RESULTING FROM
A NORTHEAST LOW LEVEL FLOW BRINGING IN DRIER AIR FROM EASTERN
ONTARIO. THE CLOUDS HAVE HELPED TO HOLD TEMPERATURES UP INTO THE
UPPER TEENS TO MID 20S...DESPITE A COLD ADVECTION PATTERN IN PLACE.
925MB TEMPS RANGED FROM -7 TO -11C PER RAP ANALYSIS.
MUCH OF THE NEXT 24 HOURS IS RELATIVELY QUIET. UPPER RIDGING OVER
THE WESTERN U.S. IS PROGGED TO FLATTEN OUT AND GET PUSHED EASTWARD
INTO THE FORECAST AREA TONIGHT...IN RESPONSE TO THE POTENT TROUGH
ALONG THE WEST COAST BREAKING APART AND MOVING INTO THE DAKOTAS BY
12Z TUESDAY. SUBSIDENCE ASSOCIATED WITH THE UPPER RIDGING SHOULD
HELP KEEP CONDITIONS DRY. THE MAIN CONCERN REVOLVES AROUND THE
CURRENT STRATUS DECK AND POTENTIAL FOR CLEARING. LOOKING AT THE 925-
850MB WIND FLOW...TO SEE IF THAT CLEARING IN NORTHEAST WI CAN MAKE
IT INTO THE FORECAST AREA...THAT FLOW IS PROGGED TO WEAKEN AND BACK
MORE NORTHERLY THROUGH THE DAY. WE WILL HAVE DAYTIME HEATING TO HELP
MIX SOME...SO IT WOULD SEEM THAT THE EAST HALF OF THE FORECAST AREA
WOULD STAND TO HAVE THE BEST CHANCE TO SCATTER/CLEAR OUT. FROM THE
MISSISSIPPI RIVER WEST...IT COULD EASILY STAY CLOUDY ALL DAY AND
INTO TONIGHT. GIVEN THE EXPECTED CLOUD TRENDS AND 925MB TEMPS ONLY
FORECAST TO WARM MAYBE 1C TODAY...TEMPERATURES ARE GOING TO STRUGGLE
TO CLIMB. MAYBE WE GET A 5 DEGREE RISE. LOWS TONIGHT WILL BE COLDEST
TOWARDS CENTRAL WI WITH THE BEST CHANCE TO HAVE CLEAR SKIES AND
LIGHT WINDS. COULD SEE POTENTIAL FOR SINGLE DIGIT LOWS WHERE IT
CLEARS OUT. OTHERWISE MORE TEENS TO LOW 20S SEEMS REASONABLE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 319 AM CST MON FEB 9 2015
HIGHLIGHTS/CONCERNS...
1. PRECIPITATION CHANCES/AMOUNTS/TYPE TUESDAY-TUESDAY NIGHT
2. WINDS/BLOWING SNOW POTENTIAL WEDNESDAY-WEDNESDAY NIGHT
3. WIND CHILLS THURSDAY MORNING
4. ANOTHER ARCTIC BLAST LOOKING MORE LIKELY FOR SATURDAY
THE SHORTWAVE TROUGH OVER THE DAKOTAS AT 12Z TUESDAY IS PROGGED TO
MOVE THROUGH THE FORECAST AREA TUESDAY EVENING...WITH YET A SECOND
SHORTWAVE TROUGH COMING THROUGH AFTER MIDNIGHT TUESDAY NIGHT. DPVA
FROM BOTH TROUGHS COMBINED WITH DECENT ISENTROPIC LIFT...ESPECIALLY
FROM THE FIRST ONE...WILL BRING PRECIPITATION TO THE FORECAST AREA.
BEST JUXTAPOSITION OF MOISTURE WITH FORCING REMAINS NORTH OF I-90
AND GIVEN VERY GOOD RUN TO RUN CONSISTENCY...HAVE CONTINUED TO
INCREASE PRECIPITATION CHANCES. IT SHOULD BE NOTED THAT A BREAK IN
PRECIPITATION IS LIKELY BETWEEN THE 2 SHORTWAVES...MOST PROBABLE
DURING TUESDAY AFTERNOON AND EVENING SOUTH OF HIGHWAY 10. TRIED TO
CONVEY THIS IN THE GRIDDED FORECAST. THE PRECIPITATION TYPE REMAINS
PROBLEMATIC. NORTH OF I-90 CONFIDENCE IS FAIRLY HIGH FOR SNOW WITH
NO ISSUES OF A WARM LAYER OR LOSING ICE IN THE CLOUD. SOUTH OF I-90
BOTH OF THOSE ISSUES EXIST...BUT AT THE SAME TIME THERE MAY NOT BE
MUCH PRECIPITATION SOUTH OF I-90. THUS...THE AMOUNT OF ANY SLEET OR
FREEZING RAIN/DRIZZLE IS EXTREMELY UNCERTAIN. REGARDING SNOWFALL
AMOUNTS...GIVEN THE DENDRITIC GROWTH ZONE IS UP HIGH AND
THIN...ANTICIPATING SNOW TO WATER RATIOS AROUND 10 TO 1. WITH GOOD
MODEL CONSENSUS FOR 24 HOUR QPF AMOUNTS IN THE 0.2-0.3 INCH RANGE
WHERE SNOW IS THE MAIN P-TYPE...SHOULD BE LOOKING AT 2-3 INCHES OF
SNOWFALL. HIGHEST AMOUNTS WOULD OCCUR IN TAYLOR COUNTY. WINTER
WEATHER ADVISORIES ARE POSSIBLE...ESPECIALLY IF CONFIDENCE GROWS FOR
SOME FREEZING RAIN TO OCCUR.
ATTENTION THEN TURNS TO A VERY POTENT SHORTWAVE TROUGH...CURRENTLY
COMING OFF THE ARCTIC OCEAN INTO THE NORTHWEST TERRITORIES OF
CANADA...PROGGED TO DROP THROUGH THE REGION LATE WEDNESDAY INTO
WEDNESDAY NIGHT. PRECIPITATION WILL BE HARD TO COME BY FOR THE
TROUGH BECAUSE OF THE MOISTURE BEING SHUNTED AWAY BY THE
TUESDAY/TUESDAY NIGHT SYSTEM. HOWEVER...THERE COULD BE SOME
INSTABILITY INDUCED SNOW SHOWERS PRODUCED WEDNESDAY NIGHT AS THE
TROUGH COMES THROUGH. MORE SIGNIFICANTLY...THE TROUGH BRINGS IN AN
INCREASE IN WINDS AND ARCTIC AIR. NORTHWEST 925MB WINDS INCREASE TO
30 TO 40 KT DURING THE AFTERNOON AND EVENING...CAUSING THE
ASSOCIATED TEMPS TO PLUMMET FROM -8 TO -12C AT 18Z WED TO -20 TO
-25C AT 12Z THU. THOSE 12Z THU READINGS ARE COLDER THAN BEFORE
AND THUS HAVE HAD TO LOWER LOWS A FEW DEGREES WEDNESDAY NIGHT.
THESE LOWS COMBINED WITH THE WINDS ARE MAKING A WIND CHILL
ADVISORY LOOK MORE LIKELY WEST OF THE MS RIVER AND OVER NORTH
CENTRAL WI. ADDITIONALLY...WITH MODEL SOUNDINGS DEPICTING MIXING
TO 850- 900MB...30 KT GUSTS SEEM EASILY POSSIBLE. THESE GUSTS WILL
CAUSE ANY SNOW FROM TUESDAY...TUESDAY NIGHT AND WEDNESDAY NIGHT TO
BLOW AROUND. THEREFORE...ADDED SOME PATCHY BLOWING SNOW TO THE
FORECAST.
THE ARCTIC AIR LOOKS TO LINGER OVER THE AREA ON THURSDAY SO LOWERED
HIGHS A FEW DEGREES. HOWEVER...BRIEF UPPER RIDGING THEN COMES
SOUTHEAST OVER THE AREA FOR THURSDAY NIGHT INTO FRIDAY TO BRING IN
WARMER AIR. 925MB TEMPS CLIMB TO -7 TO -12C BY 00Z SAT ACCORDING TO
THE 09.00Z EC/GFS. SOME LIGHT SNOW COULD ACCOMPANY THIS WARMER AIR
FOR FRIDAY.
ANOTHER ARCTIC BLAST THEN LOOKS TO AFFECT THE REGION FOR SATURDAY...
CAUSED BY A VERY POTENT SHORTWAVE TROUGH PROGGED TO DROP DOWN INTO
THE WESTERN GREAT LAKES. THIS TROUGH IS CURRENTLY OVER THE ARCTIC
OCEAN JUST NORTH OF EASTERN SIBERIA...A GREAT SOURCE REGION FOR VERY
COLD AIR. 850MB TEMPERATURE STANDARDIZED ANOMALIES FALL TO -2 TO
-2.5 ON SATURDAY PER THE 09.00Z EC/GFS...AND AS SUCH THE MEX
GUIDANCE AND ECMWF MAX T GUIDANCE ONLY HAVE HIGHS IN THE SINGLE
DIGITS. ACCOMPANYING THIS SHORTWAVE TROUGH IS ALSO A STRONG SURGE OF
WIND SO WE COULD BE DEALING WITH MORE WIND CHILL ISSUES. FOR NOW
FOLLOWED A CONSENSUS BLEND OF ALL GUIDANCE...WHICH IS WEAKER ON
WINDS AND WARMER ON TEMPERATURES. HOWEVER...WINDS MAY NEED TO BE
INCREASED ALONG WITH TEMPERATURES LOWERED OVER THE NEXT FEW DAYS IF
MODELS CONTINUE TO PROG THE TROUGH GOING THROUGH THE WESTERN GREAT
LAKES.
WE SHOULD SEE SOME MODIFICATION OF THE ARCTIC AIR FOR SUNDAY AND
MONDAY AS THE POTENT TROUGH DIGS AND HEADS OFF THE U.S. EAST COAST.
SIMILAR TO FRIDAY...MAY SEE A LITTLE LIGHT SNOW WITH THE WARM
ADVECTION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 543 AM CST MON FEB 9 2015
DRIER AIR MOVING INTO THE AREA FROM NORTHEAST WISCONSIN WILL CAUSE
CEILINGS TO GRADUALLY RISE AND EVENTUALLY CLEAR. JUST IN THE PAST
2 TO 3 HOURS...CEILINGS NORTH OF INTERSTATE 90 IN WISCONSIN HAVE
BECOME VFR. THIS SHOULD OCCUR IN NORTHEAST IOWA...SOUTHEAST
MINNESOTA...AND SOUTHWEST WISCONSIN BETWEEN 09.13Z AND 09.17Z.
MODEL SOUNDINGS ARE STILL SHOWING VARYING TIMES ON WHEN SKIES WILL
CLEAR. THE RAP KEEPS SKIES CLOUDY INTO THE EVENING AT BOTH TAF
SITES. THIS SEEMS TO BE TOO SLOW. MEANWHILE THE GFS HAS THIS OCCUR
EARLY AFTERNOON WHICH MIGHT BE TOO EARLY AT THE TAF SITES. THE NAM
WAS IN BETWEEN SHOWING CLEARING AROUND 10.00Z. THIS ALSO SEEMS A
BIT TOO LATE...SO OPTED TO GO WITH A BLEND OF THE GFS AND NAM
WHICH WOULD HAVE CLEARING OCCURRING AT KLSE AT 09.22Z AMD KRST
09.23Z. ONCE SKIES CLEAR...CEILINGS WILL REMAIN VFR THROUGHOUT THE
TIME PERIOD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
319 AM CST MON FEB 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 319 AM CST MON FEB 9 2015
HIGHLIGHTS/CONCERNS
1. CAN CLOUDS CLEAR TODAY...AND WHERE.
CURRENTLY AS OF 09Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A POTENT UPPER TROUGH ALONG THE U.S. WEST COAST...RIDGING
FROM THE DESERT SOUTHWEST INTO ALBERTA...AND GENERAL TROUGHING OVER
THE EASTERN U.S.. A WEAK SHORTWAVE WAS ALSO EVIDENT OVER NORTHERN
MN. THIS SHORTWAVE WAS PRODUCING JUST SOME HIGH CLOUDS. THOSE CLOUDS
WERE OVER TOP OF AN EXPANSIVE STRATUS DECK...STRETCHING FROM NORTH
DAKOTA INTO MUCH OF MN...IA AND A LOT OF WI. HOWEVER...CLEARING WAS
EVIDENT ACROSS NORTHEAST WI MARCHING SOUTHWESTWARD...RESULTING FROM
A NORTHEAST LOW LEVEL FLOW BRINGING IN DRIER AIR FROM EASTERN
ONTARIO. THE CLOUDS HAVE HELPED TO HOLD TEMPERATURES UP INTO THE
UPPER TEENS TO MID 20S...DESPITE A COLD ADVECTION PATTERN IN PLACE.
925MB TEMPS RANGED FROM -7 TO -11C PER RAP ANALYSIS.
MUCH OF THE NEXT 24 HOURS IS RELATIVELY QUIET. UPPER RIDGING OVER
THE WESTERN U.S. IS PROGGED TO FLATTEN OUT AND GET PUSHED EASTWARD
INTO THE FORECAST AREA TONIGHT...IN RESPONSE TO THE POTENT TROUGH
ALONG THE WEST COAST BREAKING APART AND MOVING INTO THE DAKOTAS BY
12Z TUESDAY. SUBSIDENCE ASSOCIATED WITH THE UPPER RIDGING SHOULD
HELP KEEP CONDITIONS DRY. THE MAIN CONCERN REVOLVES AROUND THE
CURRENT STRATUS DECK AND POTENTIAL FOR CLEARING. LOOKING AT THE 925-
850MB WIND FLOW...TO SEE IF THAT CLEARING IN NORTHEAST WI CAN MAKE
IT INTO THE FORECAST AREA...THAT FLOW IS PROGGED TO WEAKEN AND BACK
MORE NORTHERLY THROUGH THE DAY. WE WILL HAVE DAYTIME HEATING TO HELP
MIX SOME...SO IT WOULD SEEM THAT THE EAST HALF OF THE FORECAST AREA
WOULD STAND TO HAVE THE BEST CHANCE TO SCATTER/CLEAR OUT. FROM THE
MISSISSIPPI RIVER WEST...IT COULD EASILY STAY CLOUDY ALL DAY AND
INTO TONIGHT. GIVEN THE EXPECTED CLOUD TRENDS AND 925MB TEMPS ONLY
FORECAST TO WARM MAYBE 1C TODAY...TEMPERATURES ARE GOING TO STRUGGLE
TO CLIMB. MAYBE WE GET A 5 DEGREE RISE. LOWS TONIGHT WILL BE COLDEST
TOWARDS CENTRAL WI WITH THE BEST CHANCE TO HAVE CLEAR SKIES AND
LIGHT WINDS. COULD SEE POTENTIAL FOR SINGLE DIGIT LOWS WHERE IT
CLEARS OUT. OTHERWISE MORE TEENS TO LOW 20S SEEMS REASONABLE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 319 AM CST MON FEB 9 2015
HIGHLIGHTS/CONCERNS...
1. PRECIPITATION CHANCES/AMOUNTS/TYPE TUESDAY-TUESDAY NIGHT
2. WINDS/BLOWING SNOW POTENTIAL WEDNESDAY-WEDNESDAY NIGHT
3. WIND CHILLS THURSDAY MORNING
4. ANOTHER ARCTIC BLAST LOOKING MORE LIKELY FOR SATURDAY
THE SHORTWAVE TROUGH OVER THE DAKOTAS AT 12Z TUESDAY IS PROGGED TO
MOVE THROUGH THE FORECAST AREA TUESDAY EVENING...WITH YET A SECOND
SHORTWAVE TROUGH COMING THROUGH AFTER MIDNIGHT TUESDAY NIGHT. DPVA
FROM BOTH TROUGHS COMBINED WITH DECENT ISENTROPIC LIFT...ESPECIALLY
FROM THE FIRST ONE...WILL BRING PRECIPITATION TO THE FORECAST AREA.
BEST JUXTAPOSITION OF MOISTURE WITH FORCING REMAINS NORTH OF I-90
AND GIVEN VERY GOOD RUN TO RUN CONSISTENCY...HAVE CONTINUED TO
INCREASE PRECIPITATION CHANCES. IT SHOULD BE NOTED THAT A BREAK IN
PRECIPITATION IS LIKELY BETWEEN THE 2 SHORTWAVES...MOST PROBABLE
DURING TUESDAY AFTERNOON AND EVENING SOUTH OF HIGHWAY 10. TRIED TO
CONVEY THIS IN THE GRIDDED FORECAST. THE PRECIPITATION TYPE REMAINS
PROBLEMATIC. NORTH OF I-90 CONFIDENCE IS FAIRLY HIGH FOR SNOW WITH
NO ISSUES OF A WARM LAYER OR LOSING ICE IN THE CLOUD. SOUTH OF I-90
BOTH OF THOSE ISSUES EXIST...BUT AT THE SAME TIME THERE MAY NOT BE
MUCH PRECIPITATION SOUTH OF I-90. THUS...THE AMOUNT OF ANY SLEET OR
FREEZING RAIN/DRIZZLE IS EXTREMELY UNCERTAIN. REGARDING SNOWFALL
AMOUNTS...GIVEN THE DENDRITIC GROWTH ZONE IS UP HIGH AND
THIN...ANTICIPATING SNOW TO WATER RATIOS AROUND 10 TO 1. WITH GOOD
MODEL CONSENSUS FOR 24 HOUR QPF AMOUNTS IN THE 0.2-0.3 INCH RANGE
WHERE SNOW IS THE MAIN P-TYPE...SHOULD BE LOOKING AT 2-3 INCHES OF
SNOWFALL. HIGHEST AMOUNTS WOULD OCCUR IN TAYLOR COUNTY. WINTER
WEATHER ADVISORIES ARE POSSIBLE...ESPECIALLY IF CONFIDENCE GROWS FOR
SOME FREEZING RAIN TO OCCUR.
ATTENTION THEN TURNS TO A VERY POTENT SHORTWAVE TROUGH...CURRENTLY
COMING OFF THE ARCTIC OCEAN INTO THE NORTHWEST TERRITORIES OF
CANADA...PROGGED TO DROP THROUGH THE REGION LATE WEDNESDAY INTO
WEDNESDAY NIGHT. PRECIPITATION WILL BE HARD TO COME BY FOR THE
TROUGH BECAUSE OF THE MOISTURE BEING SHUNTED AWAY BY THE
TUESDAY/TUESDAY NIGHT SYSTEM. HOWEVER...THERE COULD BE SOME
INSTABILITY INDUCED SNOW SHOWERS PRODUCED WEDNESDAY NIGHT AS THE
TROUGH COMES THROUGH. MORE SIGNIFICANTLY...THE TROUGH BRINGS IN AN
INCREASE IN WINDS AND ARCTIC AIR. NORTHWEST 925MB WINDS INCREASE TO
30 TO 40 KT DURING THE AFTERNOON AND EVENING...CAUSING THE
ASSOCIATED TEMPS TO PLUMMET FROM -8 TO -12C AT 18Z WED TO -20 TO
-25C AT 12Z THU. THOSE 12Z THU READINGS ARE COLDER THAN BEFORE
AND THUS HAVE HAD TO LOWER LOWS A FEW DEGREES WEDNESDAY NIGHT.
THESE LOWS COMBINED WITH THE WINDS ARE MAKING A WIND CHILL
ADVISORY LOOK MORE LIKELY WEST OF THE MS RIVER AND OVER NORTH
CENTRAL WI. ADDITIONALLY...WITH MODEL SOUNDINGS DEPICTING MIXING
TO 850- 900MB...30 KT GUSTS SEEM EASILY POSSIBLE. THESE GUSTS WILL
CAUSE ANY SNOW FROM TUESDAY...TUESDAY NIGHT AND WEDNESDAY NIGHT TO
BLOW AROUND. THEREFORE...ADDED SOME PATCHY BLOWING SNOW TO THE
FORECAST.
THE ARCTIC AIR LOOKS TO LINGER OVER THE AREA ON THURSDAY SO LOWERED
HIGHS A FEW DEGREES. HOWEVER...BRIEF UPPER RIDGING THEN COMES
SOUTHEAST OVER THE AREA FOR THURSDAY NIGHT INTO FRIDAY TO BRING IN
WARMER AIR. 925MB TEMPS CLIMB TO -7 TO -12C BY 00Z SAT ACCORDING TO
THE 09.00Z EC/GFS. SOME LIGHT SNOW COULD ACCOMPANY THIS WARMER AIR
FOR FRIDAY.
ANOTHER ARCTIC BLAST THEN LOOKS TO AFFECT THE REGION FOR SATURDAY...
CAUSED BY A VERY POTENT SHORTWAVE TROUGH PROGGED TO DROP DOWN INTO
THE WESTERN GREAT LAKES. THIS TROUGH IS CURRENTLY OVER THE ARCTIC
OCEAN JUST NORTH OF EASTERN SIBERIA...A GREAT SOURCE REGION FOR VERY
COLD AIR. 850MB TEMPERATURE STANDARDIZED ANOMALIES FALL TO -2 TO
-2.5 ON SATURDAY PER THE 09.00Z EC/GFS...AND AS SUCH THE MEX
GUIDANCE AND ECMWF MAX T GUIDANCE ONLY HAVE HIGHS IN THE SINGLE
DIGITS. ACCOMPANYING THIS SHORTWAVE TROUGH IS ALSO A STRONG SURGE OF
WIND SO WE COULD BE DEALING WITH MORE WIND CHILL ISSUES. FOR NOW
FOLLOWED A CONSENSUS BLEND OF ALL GUIDANCE...WHICH IS WEAKER ON
WINDS AND WARMER ON TEMPERATURES. HOWEVER...WINDS MAY NEED TO BE
INCREASED ALONG WITH TEMPERATURES LOWERED OVER THE NEXT FEW DAYS IF
MODELS CONTINUE TO PROG THE TROUGH GOING THROUGH THE WESTERN GREAT
LAKES.
WE SHOULD SEE SOME MODIFICATION OF THE ARCTIC AIR FOR SUNDAY AND
MONDAY AS THE POTENT TROUGH DIGS AND HEADS OFF THE U.S. EAST COAST.
SIMILAR TO FRIDAY...MAY SEE A LITTLE LIGHT SNOW WITH THE WARM
ADVECTION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1114 PM CST SUN FEB 8 2015
LARGE EXPANSE OF MVFR CLOUDS REMAINS OVER THE UPPER MIDWEST THIS
EVENING. HOWEVER...SOME DRIER AIR CAN BE SEEN WORKING SOUTHWEST
ACROSS THE EASTERN SECTIONS OF LAKE SUPERIOR AND THE U.P. OF
MICHIGAN. THE 09.00Z NAM SEEMS TO HAVE A GOOD HANDLE ON THIS DRIER
AIR AND CONTINUES TO WORK IT SOUTHWEST AND OVERSPREADS THE REGION
LATE MONDAY AFTERNOON. THE 09.00Z GFS IS MUCH MORE AMBITIOUS WITH
THE DRYING AND WOULD SUGGEST THE LOW CLOUDS WOULD CLEAR OUT MONDAY
MORNING. THE 09.03Z RAP IS IN CLOSER AGREEMENT WITH THE NAM
SHOWING THE LOW LEVEL MOISTURE REMAINING IN PLACE THROUGH THE END
OF ITS MODEL RUN TIME...WHICH IS 21Z MONDAY AFTERNOON. WILL GO
WITH THE SLOWER CLEARING TRENDS OF THE NAM AND RAP AND HOLD THE
CLOUDS IN UNTIL VERY LATE MONDAY AFTERNOON AND THEN SCATTER THEM
OUT FOR VFR CONDITIONS MONDAY EVENING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1114 PM CST SUN FEB 8 2015
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 230 PM CST SUN FEB 8 2015
FORECAST FOCUS IS ON THE WINTER PCPN EXPECTED FOR TUE INTO WED.
MODELS HAVE BEEN IN GOOD AGREEMENT WITH PUSHING A SHORTWAVE TROUGH
INTO A WEST COAST RIDGE...BREAKING IT DOWN A BIT...BUT SLIDING THE
TROUGH ACROSS THE NORTHERN PLAINS AND OVER THE UPPER MISSISSIPPI
RIVER VALLEY ON TUE. BROAD THERMODYNAMIC FORCING LEADS THE SHORTWAVE
INTO THE REGION...WITH WARM AIR ADVECTION IN THE 925-700 MB LAYER
AND ISENTROPIC UPGLIDE ALONG THE 280-295 K SURFACES. SOME QG
CONVERGENCE WITH IT...STRONGER IN THE 850-700 MB LAYER. ITS NOT AN
OVERLY DYNAMIC SYSTEM...WITH MUCH OF ITS LIFT FROM THE SOMEWHAT DEEP
BUT NOT STRONG THERMODYNAMICS.
WHILE THE MODELS ALL AGREE ON BRINGING THIS SYSTEM ACROSS THE
REGION...THERE ARE DIFFERENCES ON HOW FAST AND HOW FAR SOUTH. THE
GFS AND GEM ARE QUICKER BY 6-12 HOURS COMPARED TO THE NAM AND ECMWF.
THE 08.12Z EC RUN IS FARTHER NORTH THAN THE OTHER MODELS...BUT ALL
SAY PCPN IS LIKELY ALONG I-90 AND NORTH. WILL TREND POPS HIGHER IN
THE NORTH WITH THIS HIGH CONSENSUS...AND TAKE A BLEND FOR TIMING.
SEVERAL CONSIDERATIONS FOR PCPN TYPE AS A WARM LAYER A LOFT AND LOSS
OF ICE IN THE CLOUD WILL BE FACTORS.
SATURATION INCREASES WITH THE APPROACH OF THE SYSTEM...AND NAM/GFS
BUFKIT SOUNDINGS SUGGEST IT WILL BE DEEP ENOUGH TO HAVE ICE IN THE
CLOUD FOR MUCH OF THE FORECAST AREA - ESPECIALLY I-90 AND NORTH.
SOUTH OF THERE ITS TOUCH AND GO WHETHER THERE WILL BE ICE. AS THE
SFC LOW TRACKS EAST TUE NIGHT THERE LOOKS TO BE A LOSS OF ICE FOR
AWHILE...WITH DEEPER SATURATION RETURNING AND THUS ICE IN
THE CLOUD...IN THE DEFORMATION REGION OF THE DEPARTING LOW.
FOR AMOUNTS...BULK OF THE QPF RESTS TO THE NORTH. DENDRITIC GROWTH
ZONE IS FAIRLY SHALLOW PER THE SREF AND BUFKIT SOUNDINGS. COBB
OUTPUT CONCURS...WITH GENERALLY 10:1 OR LESS FOR SNOW RATIOS. AS IT
STANDS RIGHT NOW...LOOKING AT 2 TO POTENTIALLY 4 INCHES NORTH OF
HIGHWAY 10 IN NORTH-CENTRAL WI...SOUTH TO I-90 ABOUT 1-2 INCHES.
FURTHER SOUTH A WINTRY MIX WILL KEEP AMOUNTS TO LESS THAN AN
INCH...BUT ALSO HAS THE POTENTIAL FOR A LIGHT GLAZE OF ICE.
COULD NEED A WINTER WEATHER ADVISORY FOR TUE-TUE NIGHT FOR SNOW IN
THE FAR NORTH...AND POSSIBLY FARTHER SOUTH IF THE FREEZING PCPN IS
REALIZED AND RESULTS IN IMPACTS TO TRAVEL.
TIGHT PRESSURE GRADIENT POST THE LOW FOR WED SHOULD RAMP WINDS UP.
DEPENDING ON WHERE THE SNOW FALLS - AND HOW MUCH - THERE COULD BE
SOME BLOWING/DRIFTING CONCERNS. GUSTS FROM 30 TO 35 MPH OVER THE
OPEN TERRAIN OF SOUTHEAST MN/NORTHEAST IA LOOK LIKELY AT THIS TIME.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 230 PM CST SUN FEB 8 2015
HIGH PRESSURE BUILDS IN BEHIND THE DEPARTING STORM SYSTEM FROM
TUE...WITH THE SFC HIGH OVERHEAD THU NIGHT. SHOT OF COLD CANADIAN
AIR ACCOMPANIES THE HIGH...AND NAEFS 850 MB ANOMALIES SIT AT -1/-2
WED NIGHT INTO FRI. WITH THE UPPER LEVEL FLOW HOLDING
NORTHWESTERLY...THE COOLER THAN NORMAL TEMPS ARE LIKELY TO STICK
AROUND INTO THE UPCOMING WEEKEND.
SOME SUGGESTIONS IN THE GFS AND ECMWF THAT A WEAK RIPPLE IN THIS
NORTHWEST FLOW COULD SLIDE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY
FRIDAY. QUICK MOVER...BUT COULD BRING A PERIOD OF LIGHT SNOW.
AMOUNTS LOOK MINIMAL AT THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1114 PM CST SUN FEB 8 2015
LARGE EXPANSE OF MVFR CLOUDS REMAINS OVER THE UPPER MIDWEST THIS
EVENING. HOWEVER...SOME DRIER AIR CAN BE SEEN WORKING SOUTHWEST
ACROSS THE EASTERN SECTIONS OF LAKE SUPERIOR AND THE U.P. OF
MICHIGAN. THE 09.00Z NAM SEEMS TO HAVE A GOOD HANDLE ON THIS DRIER
AIR AND CONTINUES TO WORK IT SOUTHWEST AND OVERSPREADS THE REGION
LATE MONDAY AFTERNOON. THE 09.00Z GFS IS MUCH MORE AMBITIOUS WITH
THE DRYING AND WOULD SUGGEST THE LOW CLOUDS WOULD CLEAR OUT MONDAY
MORNING. THE 09.03Z RAP IS IN CLOSER AGREEMENT WITH THE NAM
SHOWING THE LOW LEVEL MOISTURE REMAINING IN PLACE THROUGH THE END
OF ITS MODEL RUN TIME...WHICH IS 21Z MONDAY AFTERNOON. WILL GO
WITH THE SLOWER CLEARING TRENDS OF THE NAM AND RAP AND HOLD THE
CLOUDS IN UNTIL VERY LATE MONDAY AFTERNOON AND THEN SCATTER THEM
OUT FOR VFR CONDITIONS MONDAY EVENING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1150 PM CST TUE FEB 10 2015
.UPDATE...
FOR EVENING UPDATE...
MADE SOME CHANGES TO AERIAL COVERAGE IN POPS/WX FOR TONIGHT...WITH
FOCUS INITIALLY ALONG RELATIVELY NARROW BAND SEEN IN RADAR RETURNS
FROM PEORIA NORTHEAST TO NEAR JOLIET AT 815 PM.
00Z SOUNDING FROM DVN SHOWS IMPRESSIVE WARM LAYER OF +6 C AT ABOUT
870 MB...WITH STEEP LAPSE RATES FROM THERE TO NEAR 700 MB...AND
ANOTHER LAYER OF STEEP LAPSE RATES ABOVE ABOUT 640 MB. GIVEN THESE
STEEP LAPSE RATES ALOFT IT/S NOT SURPRISING TO SEE A CONVECTIVE
NATURE TO RADAR RETURNS ACROSS THE AREA THIS EVENING...WITH 35-40
DBZ RETURNS NOTED IN "CORES" SOUTHWEST OF KLOT. THIS APPEARS TO BE
IN LINE WITH LOW LEVEL THERMAL ADVECTION AXIS PER 00Z RAOB ANALYSIS
AND SPC MESOANALYSIS DATA. GIVEN THERMAL PROFILES WOULD EXPECT
RAIN/FREEZING RAIN TO BE A PRIMARY PRECIP TYPE...THOUGH THE
CONDITIONALLY UNSTABLE LAYER ALOFT APPEARS TO BE PRODUCE MAINLY
GRAUPEL/ICE PELLETS WHERE THE STRONGER RADAR RETURNS ARE.
THANKFULLY...THE MUCH WEAKER RETURNS ELSEWHERE AND DRY LOW LEVELS
WERE RESULTING IN LITTLE/NO PRECIPITATION REACHING THE GROUND PER
SURFACE OBS AND PING PROJECT DATA.
PARENT SHORT WAVE CIRCULATION CLEARLY SEEN IN REGIONAL RADAR MOSAIC
LIFTING EAST-NORTHEAST ACROSS WI...AND EXPECT MOST OF THE CURRENT
LIGHT BANDED PRECIP WILL MOVE EAST OF THE AREA BY/SHORTLY AFTER
MIDNIGHT. SECONDARY SHORT WAVE CURRENTLY HEADING INTO SOUTHWEST
MINNESOTA WILL DIG TOWARD THE AREA OVERNIGHT HOWEVER...WITH SURFACE
LOW PRESSURE CURRENTLY OVER MINNESOTA MOVING EAST AND THE TRAILING
SURFACE TROUGH/OCCLUDED FRONT MOVING INTO THE CWA LATE
TONIGHT/WEDNESDAY MORNING. AMPLE LOW-LEVEL MOISTURE EXISTS WITHIN
THE LOW LEVEL FRONTAL ZONE...NOTED IN EXTENSIVE AREA OF LOW CLOUDS
ACROSS IA/MN/WI. FORECAST SOUNDINGS SUGGEST POTENTIAL FOR AT LEAST
SOME PATCHY LIGHT FREEZING DRIZZLE OVERNIGHT INTO EARLY WEDNESDAY AS
SHORT WAVE PRODUCES LARGE SCALE ASCENT ATOP SHALLOW MOIST NEAR
SURFACE LAYER...WHICH FORECAST SOUNDINGS INDICATE WILL NOT BE COOL
ENOUGH FOR ICE NUCLEI. THEREFORE...LIGHT FREEZING DRIZZLE POTENTIAL
INCREASES AFTER MIDNIGHT INTO EARLY WEDNESDAY MORNING...BEFORE
FRONTAL PASSAGE AND GUSTY NORTHWEST WINDS DRY THINGS OUT.
RATZER
&&
.SHORT TERM...
345 PM CST
THROUGH THURSDAY...
MAIN FORECAST CONCERNS ARE WITH PRECIP/PRECIP TYPE LATE THIS
AFTERNOON INTO THE OVERNIGHT...LINGERING LIGHT SNOW SHOWERS ON
THURSDAY...AND THEN WITH ACCUMULATING LAKE EFFECT SNOW EXPECTED
LATE WEDNESDAY NIGHT INTO THURSDAY.
LATEST RADAR MOSAIC SHOWING LEADING EDGE OF PRECIP STILL STEADILY
PROGRESSING EAST ACROSS EASTERN IOWA...AND CURRENTLY APPROACHING
FAR NORTHWEST ILLINOIS AT THIS TIME. THIS PRECIP IS RIDING ALONG
WARM ADVECTION WING...OUT AHEAD OF THE SOUTHERN END OF A FAIRLY
STOUT VORT MAX MOVING THROUGH MINNESOTA AND WISCONSIN. WITH THIS
VORT MAX SHIFTING EAST THIS AFTERNOON INTO THE EVENING...LARGE
SCALE ASCENT WILL CONTINUE TO QUICKLY INCREASE ACROSS THE CWA.
PREVIOUSLY MENTIONED DRY AIR IN PLACE IS NOW APPEARING TO BE TOO
MUCH A FACTOR AS FORCING SHOULD BE ABLE TO OVERCOME IT. THIS WILL
LIKELY OCCUR AS SOON AS 23-00Z FOR THE NORTHWEST CWA AND THEN MORE
TOWARDS THE 2-3Z TIME FRAME FOR NORTH CENTRAL AND NORTHEAST
ILLINOIS. DID BRING POPS FURTHER SOUTH TOWARDS THE I80 CORRIDOR
BRIEFLY THIS EVENING...BUT STILL THINK THE BEST CHANCES FOR PRECIP
WILL BE ALONG AND NORTH OF THE I88 CORRIDOR. RAISED POPS TO HIGH
CHANCE POPS...AND LIMITED THEM HERE DUE TO OVERALL DURATION AND
COVERAGE WHICH APPEAR TO BE SMALL. UPON SATURATION...THERMAL
PROFILES WOULD SUGGEST A BRIEF MIX OF SNOW AND SLEET AT THE ONSET
BEFORE A QUICK TRANSITION OVER TO ALL SNOW OCCURS. EXPECT THIS
TREND TO CONTINUE THROUGH THE EVENING BUT WITH ONCE AGAIN SMALLER
WINDOW OF PRECIP EXPECTED...DONT ANTICIPATE MUCH IN TERMS OF ANY
ACCUMULATION. AT MOST WOULD A COUPLE OF TENTHS OF AN INCH OF
SNOWFALL. DEEPER MOISTURE IS LOST MORE TOWARDS 5Z ACROSS MUCH OF
THE CWA...BUT STILL HOVERING AROUND THE POSSIBILITY FOR INCLUSION
OF CRYSTALS. THIS WILL OCCUR THE DEPARTURE OF THE INITIAL
WAVE...BUT WITH THE ARRIVAL OF AN ADDITIONAL WAVE AND SURFACE
TROUGH/FRONT INTO EARLY WEDNESDAY MORNING. COVERAGE AND DURATION
OF ADDITIONAL PRECIP SHOULD ALSO BE SMALL...BUT WITH SNOW AND
FREEZING DRIZZLE THEN POSSIBLE. ANY LINGERING PRECIP SHOULD BE
DEPARTING WEDNESDAY MORNING...BUT WITH A SLIGHT POSSIBILITY FOR
FOR ADDITIONAL SCATTERED LIGHT SNOW SHOWERS POSSIBLE IN THE
AFTERNOON.
LARGE UPPER LEVEL TROUGH WILL BE DIGGING SOUTH ACROSS THE REGION
WEDNESDAY NIGHT...AS A STRONG VORT MAX ROUNDS THE BASE OF THIS
TROUGH. THIS WILL MARK THE ARRIVAL OF A MUCH COLDER AIRMASS AND
WITH THIS STRONG VORT MAX MOVING ACROSS THE AREA...SNOW SHOWERS
WILL LIKELY REDEVELOP WEDNESDAY NIGHT. OF MORE CONCERN IS WITH THE
LAKE EFFECT SNOW SHOWERS EXPECTED ACROSS NORTHWEST INDIANA...LATE
WEDNESDAY NIGHT INTO MUCH OF THURSDAY. AS THIS COLDER AIR SPILLS
SOUTH ACROSS THE LAKE WEDNESDAY NIGHT...THERMODYNAMICS OVER THE
LAKE BECOME HIGHLY CONDUCIVE FOR MODERATE TO HEAVY LAKE EFFECT
SNOW ACROSS THE SOUTHERN END OF THE LAKE. IMPRESSIVE INVERSION
HEIGHT AS WELL AS EVEN MORE IMPRESSIVE DELTA TS COINCIDING WITH
STRONG SYNOPTIC LIFT AND LIKELY STRONG CONVERGENCE WILL ALL BE
PRESENT...BUT WITH CONFIDENCE AS TO WHERE THE BEST SNOW WILL
DEVELOP IS STILL ON THE LOWER SIDE. AM CONFIDENT THAT PORTER
COUNTY WILL OBSERVE SNOW BUT AM NOT AS CONFIDENT WITH THE DURATION
OF THE LIKELY HEAVIER SNOW. CURRENT THINKING/FORECAST IS FOR LAKE
EFFECT TO DEVELOP LATE THURSDAY NIGHT INTO WEDNESDAY MORNING WITH
THE BEST ACCUMULATION DURING THIS TIME. BASED ON THIS...HAVE
ADVISORY LEVEL SNOWFALL TOTALS ACROSS PORTER COUNTY. IF LAKE
EFFECT SNOWBAND WERE TO SETUP ACROSS PORTER COUNTY WHICH IS STILL
A DEFINITE POSSIBILITY...THEN TOTALS COULD EASILY EXCEED 6 INCHES.
WILL NEED TO MONITOR THIS PERIOD FOR THE POTENTIAL OF HIGHER
SNOWFALL TOTALS AND WITH STRONG NORTHERLY WINDS ALSO
EXPECTED...THEN BLOWING AND DRIFTING SNOW COULD EASILY BECOME
ISSUES. AS HIGH PRESSURE BUILDS ACROSS THE REGION AND LOW LEVEL
FLOW BACKS...LAKE EFFECT SHOULD DIMINISH THURSDAY EVENING.
RODRIGUEZ
&&
.LONG TERM...
345 PM CST
THURSDAY NIGHT THROUGH TUESDAY...
HIGH PRESSURE IN PLACE AND THIS COLDER AIRMASS WILL LIKELY PRODUCE
LOW TEMPS IN THE SINGLE DIGITS AND WITH LOCATIONS ACROSS NORTH
CENTRAL ILLINOIS MORE THAN LIKELY FALLING BELOW ZERO. BRIEF LULL
IN THE SNOW WILL END ON FRIDAY AS ANOTHER WAVE PUSHES THROUGH THE
REGION...PRODUCING LIGHT ACCUMULATIONS OVER THE ENTIRE CWA.
ANOTHER PUSH OF COLDER AIR IS APPEARING LIKELY FOR THE WEEKEND AS
ANOTHER LARGE TROUGH DIGS ACROSS THE REGION. DID LOWER TEMPS BELOW
GUIDANCE AS A COLDER TREND IS MORE FAVORED. THIS WILL ALSO HELP
PRODUCE ANOTHER GOOD SETUP FOR LAKE EFFECT SNOW DEVELOPMENT ACROSS
NORTHWEST INDIANA ESPECIALLY SATURDAY AND SATURDAY NIGHT...WITH
SEVERAL INCHES OF SNOW A DISTINCT POSSIBILITY DURING THIS PERIOD.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* MVFR CIGS DEVELOPING OVERNIGHT AND CONTINUING THRU THE PERIOD.
* POSSIBLE IFR CIGS THRU MID MORNING.
* POSSIBLE LIGHT FREEZING DRIZZLE TOWARD DAYBREAK.
* STRONG/GUSTY NORTHWEST WINDS DEVELOPING LATE MORNING AND
CONTINUING THRU THE PERIOD.
* CHANCE OF SNOW SHOWERS WEDNESDAY EVENING/NIGHT. CMS
//DISCUSSION...UPDATED 06Z...
LOW PRESSURE OVER THE UPPER MIDWEST WILL MOVE ACROSS THE NORTHERN
LAKES THIS MORNING. A TRAILING COLD FRONT WILL MOVE ACROSS THE
TERMINALS LATE THIS MORNING. SOUTHERLY WINDS AHEAD OF THIS LOW
WILL SHIFT MORE WESTERLY AFTER SUNRISE AND THEN TO THE NORTHWEST
AFTER THE COLD FRONT PASSES. SPEEDS UP TO 10KTS OVERNIGHT WILL
INCREASE TO 10-15KTS LATER THIS MORNING. BUT ONCE WINDS SHIFT TO
THE NORTHWEST...SPEEDS WILL INCREASE TO 15-18KTS WITH GUSTS INTO
THE MID/UPPER 20 KT RANGE. AS COLDER AIR SPREADS ACROSS THE AREA
WEDNESDAY NIGHT...SPEEDS/GUSTS WILL LIKELY INCREASE FURTHER.
VFR CIGS WILL LOWER TO MVFR FROM WEST TO EAST OVERNIGHT AS THE
LOW LEVELS SATURATE. ITS POSSIBLE CIGS MAY LOWER TO IFR AND IF
THIS OCCURS...IT WOULD MOST LIKELY BE AFTER DAYBREAK AND AHEAD OF
THE COLD FRONT...BUT CONFIDENCE IS LOW FOR IFR CIGS.
AS CIGS LOWER TOWARD LOW MVFR BY DAYBREAK...SOME PATCHY FREEZING
DRIZZLE IS ALSO POSSIBLE BUT CONFIDENCE IS ALSO LOW. TEMPS MAY
ALSO WARM TO NEAR OR JUST ABOVE FREEZING BY 12Z-14Z...LIMITING ANY
POTENTIAL ICING POTENTIAL...SHOULD THE DRIZZLE MATERIALIZE.
LATER WEDNESDAY EVENING...AS THE COLDER AIR SPREADS ACROSS THE
AREA...LOW LEVEL INSTABILITY LOOKS SUFFICIENT FOR SOME SNOW
SHOWERS AND WHILE OVERALL DURATION COULD BE JUST A FEW HOURS...
KEPT A LONGER DURATION PROB GOING FOR UNCERTAIN TIMING. CMS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH FOR MVFR CIGS DEVELOPING OVERNIGHT...MEDIUM FOR TIMING.
* LOW FOR IFR CIGS OVERNIGHT/WEDNESDAY MORNING.
* LOW FOR LIGHT FREEZING DRIZZLE TOWARD DAYBREAK.
* HIGH FOR WINDS THRU THE PERIOD.
* MEDIUM FOR SNOW SHOWERS WEDNESDAY EVENING/NIGHT...LOW FOR
TIMING/DURATION AND SPECIFIC VIS REDUCTIONS. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
* THURSDAY...MVFR CIGS POSSIBLE EARLY. STRONG/GUSTY NORTHWEST WINDS.
* FRIDAY...SLIGHT CHANCE OF SNOW. MVFR POSSIBLE. WEST/SOUTHWEST
WINDS.
* SATURDAY...CHANCE OF FLURRIES. MVFR POSSIBLE. VERY STRONG/GUSTY
NORTHWEST WINDS.
* SUNDAY...DRY/VFR. WEST/SOUTHWEST WINDS.
* MONDAY...MVFR POSSIBLE. SOUTHWEST WINDS.
KJB
&&
.MARINE...
322 PM CST
MULTIPLE MARINE CONCERNS AS WE ENTER A VERY COLD AND ACTIVE PATTERN.
THIS EVENING...THERE COULD BE BRIEF WINDOW OF NEAR SMALL CRAFT
CONDITIONS ALONG THE FAR NORTHEAST ILLINOIS SHORE AS SOUTHEAST
WINDS INCREASE TO 15 TO 25 KT. WINDS WILL THEN SHIFT SOUTHERLY ON
THE ENTIRE LAKE AS A WEAK LOW OVER THE UPPER MIDWEST APPROACHES.
THERE COULD BE A FEW GUSTS TO 30 KT ON THE NORTHERN HALF OF THE
LAKE TONIGHT IN THE PEAK OF THE SOUTHERLY FLOW.
A STRONG COLD FRONT TRAILING FROM THE LOW WILL SWEEP ACROSS THE LAKE
BY MID DAY WEDNESDAY OR SO...WITH AN EXPANSIVE 1040+ MB ARCTIC HIGH
SPREADING IN FROM THE NORTHERN PLAINS BEHIND IT. VERY TIGHT PRESSURE
GRADIENT AND BITTERLY COLD AIR MASS WILL ENABLE WINDS TO QUICKLY
RAMP UP TO GALE FORCE BY EARLY WEDNESDAY EVENING FOR THE OPEN WATERS
THEN LATER IN THE EVENING FOR THE NEARSHORE. IN ADDITION...HEAVY
FREEZING SPRAY WILL DEVELOP AS AIR TEMPERATURES PLUMMET. HAVE ISSUED
A GALE WARNING AND HEAVY FREEZING SPRAY WARNING FOR THE LAKE
WEDNESDAY EVENING/NIGHT INTO THURSDAY AFTERNOON...WITH A SMALL CRAFT
LEADING UP TO THE GALE WARNING FOR THE NEAR SHORE WEDNESDAY
AFTERNOON AND EVENING. EXPECTING PEAK GUSTS UP TO 40 KT WITH THIS
EVENT...AND THERE IS SOME POTENTIAL FOR UP TO 45 KT IN/NEAR THE
LAKE EFFECT CONVERGENCE BAND EARLY THURSDAY MORNING.
THERE WILL BE ONLY A BRIEF CALMER PERIOD THURSDAY NIGHT INTO
FRIDAY...FOLLOWED BY YET ANOTHER STRONG ARCTIC FRONT SWEEPING ACROSS
THE LAKE FRIDAY EVENING/NIGHT. VERY SIMILAR SETUP TO WEDNESDAY NIGHT
INTO THURSDAY BUT AN EVEN TIGHTER PRESSURE GRADIENT DUE TO STRONGER
LOW PRESSURE TO THE EAST SHOULD RESULT IN AT LEAST GALES TO 45 KT
AND HEAVY FREEZING SPRAY. WINDS...WAVES AND FREEZING SPRAY WILL
DIMINISH LATER SATURDAY NIGHT INTO SUNDAY AS THE ARCTIC HIGH MOVES
OVER THE LAKE.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 AM
WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...NOON WEDNESDAY TO MIDNIGHT THURSDAY.
HEAVY FREEZING SPRAY WARNING...LMZ080-LMZ261-LMZ362-LMZ364-
LMZ366-LMZ563-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-
LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...MIDNIGHT
THURSDAY TO 3 PM THURSDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...MIDNIGHT THURSDAY TO 3 PM THURSDAY.
GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...6 PM WEDNESDAY TO 3 PM
THURSDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1103 PM CST Tue Feb 10 2015
.UPDATE...
ISSUED AT 825 PM CST TUE FEB 10 2015
Fast moving weather system passing to our north has spread a band
of mid level clouds east into central Illinois this evening. ILX and
DVN 00z soundings indicating a fairly substantial (4-6 deg C) around
850 mb or approx 5000 feet above ground. Have had some reports of
sleet and even some brief light freezing rain/mist near Altona in
northern Knox county over the past hour with the higher dBZs now
headed towards Lacon where a brief period of sleet will be possible
over the next half hour. The band of very light precip was tracking
east at about 35 to 40 mph so its not going to be around our area
too much longer. Have updated the ZFP to include the potential for
a brief period of sleet and possibly a little light snow, but based
on current and forecast soundings, the better bet is with the sleet
for the next hour. Otherwise, cloud cover and a southerly wind
tonight should help keep temperatures from falling off too much
further before a cold front, one of 3 strong fronts to push across
our area over the next week, tracks through central Illinois just
before dawn on Wednesday setting up our area for what appears to
be a windy and very cold stretch of weather.
&&
.SHORT TERM...(Tonight)
ISSUED AT 258 PM CST TUE FEB 10 2015
Stratocumulus clouds 1.5-2k ft are now west of I-55 and eroding and
will continue to decrease toward the nw over IL river valley late
this afternoon into early this evening due to influence of high
pressure ridge axis into IL. HRRR model has been handling the
clearing of low clouds well and will continue to follow its lead.
Broken to overcast mid level clouds 8-12k ft over IA and far nw IL
will spread east across central IL during this evening especially
north of I-72 where skies become mostly cloudy. These clouds ahead
of 1010 mb low pressure along the eastern ND/SD border will track
ene to the Keweenaw peninsula in upper MI by 12Z/6 am Wed with its
cold front moving toward the IL river. Meanwhile southeast IL will
likely stay in the clear most of this evening with skies becoming
partly cloudy overnight in southeast IL. Light mix of precipitation
over eastern IA and moving east into WI and far NW IL at mid
afternoon. Forecast models keep light precipitation north of I-80
tonight over northern IL. Lows tonight in the upper 20s to near 30F
with mildest readings from Springfield southwest. ESE winds less
than 10 mph to veer ssw during overnight and turn WNW nw of IL by
sunrise behind cold front.
&&
.LONG TERM...(Wednesday through Tuesday)
ISSUED AT 258 PM CST TUE FEB 10 2015
The extended will be dominated by large temperature variations,
highlighted by two surges of Arctic air into the western Great Lakes
and eastern CONUS. Precipitation will be light with any shortwaves
through Monday.
The upper ridge along the West Coast will remain a semi-permanent
feature over the 5 to 6 days, with a long wave trough east of the
Continental Divide. A brief push of warm air into the area tonight
ahead of the first cold front should help Wednesday start out with
rising temps possibly even before sunrise. The cold front could
start pushing across our western counties shortly after sunrise, but
the affects of the cold air will be delayed across the rest of the
area until afternoon when the northwest winds increase in the strong
cold air advection. A few light snow showers or flurries could
develop Wed afternoon NE of CMI to DNV where a weak shortwave helps
provide some lift in the advancing cold air. A better chance for
snow showers in our area looks to be Wed night as a strong 500mb
vort max dives south into IL. Any snow accums would be very light
and mainly confined to areas NE of BMI to MTO. Flurries could extend
as far west as Springfield and Taylorville, depending on available
moisture.
Wind chills later Wed night will drop into the -5 to -15F range,
which is just outside of our advisory levels. However, those wind
chill numbers are for the sustained winds, and gusts to 30 mph could
easily push wind chills much colder than that at times.
Thursday will be a blustery day with NW winds of 20-25 and gusts to
35 mph. Some flurries cold linger east of I-57, but the shortwave
aloft will depart east of IL early in the day to help shut down
potential for precip.
Another brief warmup is indicated for Friday, as highs climb toward
freezing in the south and into the upper 20s north.
The strongest surge of Arctic air this week is expected late Friday
night and Saturday, as a deep closed low drops straight south from
the upper latitudes into the Great Lakes region. The coldest air,
with 850 mb temperatures around -25 to -28C, will be over our area
on Saturday. Strong N winds of 25 mph gusting to 40 mph will put
wind chills into the advisory criteria between -15F and -20F
starting Saturday morning across the northern CWA. Those bitterly
cold wind chills appear likely all the way through mid-morning on
Sunday. Temperatures on Sunday will warm slightly, but still remain
well below normal in the teens to around 20. Washington`s
Birthday/Monday looks to be much warmer with highs into the low to
mid 30s as a storm system approaches southern Illinois. Some
indications are for a period of rain or snow in portions of central
IL, with a band of measurable snow possible. The track of that
system has shifted farther south in the 12z GFS, keeping light snow
confined to areas south of I-72, but the ECMWF still has the effects
of the storm reaching well into IL with rain/snow south and snow
north. Will keep chance PoPs across the entire area Monday night for
now. Beyond that, there are indications of yet another push of cold
air for late Tuesday and Tuesday night.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
ISSUED AT 1100 PM CST TUE FEB 10 2015
VFR cigs expected to deteriorate to MVFR cigs between 06z-09z
from northwest to southeast as a fast moving frontal boundary
sweeps across the region. Latest satellite data and upstream
surface observations indicate the leading edge of the MVFR
cigs were already pushing towards the Mississippi River and
based on the present movement should be approaching PIA around
06z and be into our eastern forecast sites by no later than
08z. Cigs initially were around 2500 feet but lower to between
1200-2000 feet over parts of central Iowa, which should translate
east into our area during the early morning hours. Soundings also
indicate the potential for some tempo IFR cigs by late morning
into the afternoon hours, especially across our northern TAF
locations. Models not as aggressive in clearing to our northwest
late in the afternoon so will keep the MVFR cigs going into at
least the early evening hours. Surface winds will veer more into
a southerly direction overnight with speeds of 5 to 10kts and
the switch into the west and northwest and increase in speed to
between 15 and 20 kts by late morning with gusts around 25 kts
at times during the afternoon and early evening.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...07
LONG TERM...Shimon
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS GOODLAND KS
252 AM MST WED FEB 11 2015
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 246 AM MST WED FEB 11 2015
UPPER FLOW WILL BE NORTHWEST THROUGH FRIDAY NIGHT WITH A AMPLIFIED
RIDGE OVER THE WESTERN CONUS. SURFACE HIGH PRESSURE WILL MOVE INTO
THE CENTRAL PLAINS TODAY AND TONIGHT. A TROUGH WILL MOVE INTO
EASTERN COLORADO THURSDAY/THURSDAY NIGHT AS HIGH PRESSURE SHIFTS
EAST. HIGH PRESSURE WILL MOVE INTO THE REGION BEHIND THE EXITING
SURFACE TROUGH FRIDAY/FRIDAY NIGHT.
SUBSIDENCE WILL FOLLOW THE EXITING SHORTWAVE THIS MORNING AND
CONTINUE THROUGH TONIGHT. A WEAK SHORTWAVE IS NOTED IN THE FLOW ON
THURSDAY BUT MOISTURE IS WELL TO THE EAST OF THE FA SO THAT
PRECIPITATION SHOULD BE UNLIKELY. SUBSIDENCE FOLLOWS THE EXITING
SHORTWAVE THURSDAY NIGHT AND CONTINUES THROUGH FRIDAY NIGHT. AS A
RESULT, ALL PERIODS WILL BE DRY WITH NIL POPS.
NAM BOUNDARY LAYER RH INCREASES TO 90 PERCENT AS THE COLD FRONT
MOVES INTO THE FA THIS MORNING. THE HRRR INDICATES CEILINGS OF
AROUND 1000FT. THE LOWER CEILINGS WILL MOVE OUT OF THE SOUTHERN FA
BY 17Z ACCORDING TO THE HRRR.
850 TEMPERATURES INDICATE SEASONABLE TEMPERATURES TODAY IN THE MID
40S AND THEN WARMING UP TO THE LOWER 60S IN EASTERN COLORADO
THURSDAY WITH MID 50S IN NORTHWEST KANSAS. MAX TEMPERATURES FRIDAY
SHOULD RISE TO NEAR 60. MIN TEMPERATURES SHOULD COOL TO THE LOWER
TO MID 20S TONIGHT AND THEN MODERATE TO THE LOWER 30S THURSDAY AND
FRIDAY NIGHTS.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 246 AM MST WED FEB 11 2015
SATURDAY THROUGH TUESDAY WILL SEE TEMPERATURES RETURNING TO MORE
NORMAL VALUES AS A COOLER AIR MASS MOVES OVER THE AREA BEGINNING
SATURDAY...AS WELL AS A CHANCE FOR PRECIPITATION EARLY NEXT WEEK.
OVER THE WEEKEND THE UPPER LEVEL RIDGE THAT HAS BEEN SITUATED OVER
THE GREAT BASIN WILL BE PUSHED BACK WEST AS A STRONGER UPPER LEVEL
TROUGH MOVES SOUTHEAST OUT OF CANADA. THE TROUGH WILL DEEPEN AS IT
MOVES SOUTHEAST ACROSS THE CONUS. AS IT DOES SO THE UPPER LEVEL
FLOW WILL RESEMBLE MORE OF A SPLIT FLOW SETUP...PRIOR TO THE
TROUGH REACHING THE HIGH PLAINS. IF THIS PATTERN DOES DEVELOP
THERE WILL BE VERY LITTLE CHANCE FOR PRECIPITATION MONDAY NIGHT
DUE TO THE UPPER LEVEL FORCING GOING AROUND THE AREA. HOWEVER WILL
LEAVE IN THE CONSENSUS OF MINIMAL CHANCES FOR PRECIPITATION AS THE
TROUGH MOVES THROUGH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1041 PM MST TUE FEB 10 2015
A COLD FRONT IS IN THE PROCESS OF MOVING THROUGH THE FORECAST
AREA. BEHIND THE FRONT OCCASIONAL MVFR CEILINGS CAN BE EXPECTED
UNTIL NEAR 13Z FOR BOTH TAF SITES. AFTER THAT...MVFR CONDITIONS
ARE EXPECTED FOR THE REST OF THE PERIOD. AFTER 13Z...NORTH WINDS
WILL STRENGTHEN AND PRODUCE GUSTS TO NEAR 25 KNOTS UNTIL MID
AFTERNOON WHEN THEY BEGIN TO DECREASE. LATE IN THE AFTERNOON INTO
THE EARLY AFTERNOON...THE WINDS WILL BECOME LIGHT AND VARIABLE AND
SLOW SHIFT TO A SOUTHWEST DIRECTION.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...FS
LONG TERM...JTL
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS TOPEKA KS
326 AM CST Wed Feb 11 2015
.SHORT TERM...(Today and Tonight)
Issued at 325 AM CST WED FEB 11 2015
Next in a series of cold fronts making its way southward toward the
CWA at this hour. Increasing northerly winds and stratus are
expected Eastern Kansas through the morning hours. Strong shortwave
also noted over southern Colorado, streaming stratus to the east
over Western Kansas, however energy dropping into the back of this
system should drive this southward through the day today and leave
little impact over our area.
Cold air advection continues through the day today. This combined
with stratus early should hold high temperatures only in the 30s to
near 40 this afternoon, however northerly winds will leave it
feeling like highs in the 20s to low 30s. NAM is more aggressive
with keeping clouds over the area while HRRR and GFS/EC indicate
subsidence and clearing for at least a portion of the day today.
Evening hours bring a break in the winds and the clouds, however
secondary cold front advances southward across the area after
midnight and brings in even colder temperatures in the teens. Given
north winds of 15 to 20 mph, also anticipate wind chill values near
zero, and as low as -10 near in the far northeastern counties by
early Thursday.
.LONG TERM...(Thursday through Tuesday)
Issued at 325 AM CST WED FEB 11 2015
Northwest flow aloft keeps temperatures as the main challenge into
the weekend. Surface high comes in Thursday for decreasing winds,
but the cold air in place will keep temps about 10F colder than
today. Still appears temps may be rather steady or slowly rise late
Thursday night as warm air surges back east ahead of next strong
upper wave rotating around the persistent upper level trough in the
east. This continues to suggest a much warmer Friday than recent
days, but the weekend periods bring much colder temps again with
cold front coming through late Friday night into Saturday. Have a
rather high temperature spread across the area Saturday and timing
of best cold air advection varies so confidence on specifics is low.
Limited mixing in 850mb temps around -8 C brings an even colder
Sunday.
Final few periods of this forecast bring increasing precipitation
chances. There is fairly good operational and ensemble agreement in
the western upper ridge redeveloping off the coast for a more zonal
to even southwest flow taking shape early in the week. Resulting
deep isentropic lift should be able to saturate enough of the column
for precip chances as early as late Sunday night but with greater
chances Monday into Monday night. Precip type looking more
challenging than most normal long-range forecasts with questions on
depth of moisture to produce ice in the cloud and the potential for
an above-freezing layer to develop under still cold near-surface
conditions.
&&
.AVIATION...(For the 06Z TAFs through 06Z Wednesday Night)
Issued at 1116 PM CST TUE FEB 10 2015
Latest observational trends upstream near the cold front suggest a
later arrival in gusty winds than previous forecast. VFR prevails
with an increase in mid level clouds as light northwest winds
gradually increase above 10 kts behind the boundary between 10 and
12Z. MVFR stratus accompanies the stronger winds mid morning onward.
Widespread wind gusts to 26 kts are expected shortly after sunrise
through the afternoon. Still some uncertainty from guidance on
how quickly deck scatters to VFR...occurring most likely during
the mid afternoon.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...67
LONG TERM...65
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
316 AM EST WED FEB 11 2015
.SYNOPSIS...
A LATE DAY COLD FRONT WILL BEGIN THE TRANSITION TO FRIGID TEMPERATURES
WHICH WILL PERSIST INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
OVERALL...A SOFT DAY IS ANTICIPATED FOR THE UPPER OHIO REGION AS
A STRONG SHORTWAVE TROUGH...WITH AXIS OVER THE UPPER MISSISSIPPI
VALLEY THIS MORNING...PROGRESSES OVER THE GREAT LAKES. WARM
ADVECTION IN ADVANCE OF THAT SYSTEM SHOULD SUPPORT HIGHS NEAR THE
MID FEBRUARY AVERAGES DESPITE A CLOUD INCREASE WITH THE MID LEVEL
MOISTURE SURGE. THE TEMPERATURE FORECAST WAS TWEAKED USING THE
LATEST SREF...NAM...AND RAP GUIDANCE TRENDS...BUT CHANGES WERE
MINIMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
THE ACTUAL COLD FRONT PASSAGE IS NOT EXPECTED TO BE DRAMATIC AS
FAR AS PRECIPITATION IS CONCERNED WITH THE LOW CENTER PROJECTED
TOWARD NEW YORK AND A MID LEVEL DRY SLOT RAPIDLY ENCROACHING INTO
UPPER OHIO VALLEY AIRSPACE. HOWEVER...THURSDAY TEMPERATURES WILL
BE ON THE DECLINE...WITH SNOW SHOWER COVERAGE INCREASING UNDER A
FRIGID MID LEVEL THERMAL TROUGH.
THE STEEPENING LOW LEVEL LAPSE RATES AND A SHALLOW DENDRITIC
GROWTH ZONE WILL RESULT IN INCREASED CONVECTIVE SNOW SHOWER
ACCUMULATION POTENTIAL ON THURSDAY...ESPECIALLY IN THE USUAL
UPSLOPE AREAS OF THE RIDGES AND ZONES IN LEE OF THE LAKES. NOT
MUCH CHANGE WAS NEEDED FOR THE ONGOING 1-2 FORECAST WITH 2-4
INCHES ON THE RIDGES.
EASTWARD PROGRESS OF THE MAIN MID LEVEL COLD POOL...I.E. FALLING
INVERSION LEVELS WITH DRY ADVECTION SHOULD RAPIDLY LIMIT ADDITIONAL
ACCUMULATION POTENTIAL ON THURSDAY NIGHT.
THE COLD THURSDAY NIGHT AND FRIDAY TEMPERATURE FORECAST WAS NOT
DISPUTED MUCH BY INCOMING GUIDANCE AS A HIGH AMPLITUDE EASTERN
U.S. UPPER TROUGH AXIS IS DEVELOPED SLOWLY EASTWARD...HENCE
CHANGES WERE MINIMAL ALTHOUGH THE WIND WAS REDONE USING NAM AND
GFS GRIDS. WIND CHILL INDICES STILL ARE PROJECTED INTO THE
ADVISORY RANGE OF -10 TO -20C...SO A HAZARDOUS WEATHER OUTLOOK
MENTION WILL BE MAINTAINED WITH A MENTION OF SNOW ACCUMULATION IN
THE RIDGES...WHERE THE BETTER CHANCE FOR AN ADVISORY IS ON
THURSDAY.
NO REPRIEVE IS INDICATED THIS WEEKEND AS THE ECMWF AND GFS SOLUTIONS
ARE OF A STRONG SHORTWAVE ROTATING SOUTHWARD OUT OF THE HUDSON BAY
AREA. THAT SYSTEM AS MODELED WOULD RECARVE THE UPPER TROUGH OVER
THE EASTERN U.S. CURRENT PROJECTIONS ARE THAT THE MID LEVEL LOW
CENTER WILL REMAIN NORTH OF THE AREA...THUS KEEPING THE SNOW FAVORABLE
TROWAL...FRONTOGENESIS REGIONS AT BAY. NEVERTHELESS...A COLD COLUMN
WILL MAINTAIN FRIGID TEMPERATURES AND HIGH SNOW RATIO PARAMETERS.
PRECIPITATION PROBABILTIES WERE BUMPED UP ON SATURDAY IN ACCORDANCE
WITH THESE TRENDS AND GENERALLY ARE IN LINE WITH GFS GRIDS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS UPPER LOW MOVES EAST OF THE REGION...SNOW SHOWERS WILL WIND
DOWN SATURDAY NIGHT WITH SOME LAKE EFFECT CONTINUING INTO SUNDAY.
WITH THE SURFACE HIGH THEN BUILDING INTO THE REGION SUNDAY
NIGHT...WINDS WILL DIMINISH AND ALL SNOW WILL COME TO AN END.
SUNDAY AND SUNDAY NIGHT APPEARS TO BE THE COLDEST 24 HOUR PERIOD
OF THE WINTER SO FAR...WITH HIGHS IN THE SINGLE DIGITS AND LOWS
RANGING FROM 5 ABOVE TO 10 BELOW. WINDS MAY GO LIGHT WITH THE HIGH
PRESSURE CENTER OVERHEAD...WHICH COULD LIMIT JUST HOW LOW WIND
CHILL VALUES GO. LOW MOVES NORTHEAST FROM THE SOUTHERN PLAINS
MONDAY NIGHT INTO TUESDAY. EVEN WITH WARMER TEMPERATURES MOVING IN
BY MONDAY NIGHT...TEMPERATURES WILL REMAIN COLD ENOUGH THAT ALL
PRECIPITATION SHOULD FALL AS SNOW WITH THAT SYSTEM.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
STRATUS WILL CONTINUE OVERNIGHT AT FKL/DUJ/LBE...WITH THE WESTERN
EDGE OF STRATUS CURRENTLY HOVERING JUST EAST OF AGC/MGW. LOW
CONFIDENCE FORECAST IN WHETHER THOSE TWO TERMINALS WILL BE
IMPACTED...BUT HAVE PULLED THE MENTION OF STRATUS PREVIOUSLY IN THE
PIT/BVI/HLG TAFS. MVFR FOG HAS ALSO MOVED INTO ZZV...AND SHOULD
PERSIST THROUGH THE NIGHT. STRATUS SHOULD DIMINISH IN COVERAGE AFTER
SUNRISE...ALTHOUGH FKL/DUJ COULD POTENTIALLY STAY IN THE STRATUS
THROUGH THE TAF PERIOD. HAVE GONE MORE PESSIMISTIC THAN PREVIOUS
TAFS FOR THOSE TWO SITES. COLD FRONT PUSHES THROUGH THE REGION THIS
EVENING...BRINGING RESTRICTIONS AND A SHIFT IN THE WINDS. STILL
UNSURE OF HOW LOW VISIBILITIES WILL DROP WITH SNOW SHOWERS...BUT
HAVE AT LEAST BROUGHT A MENTION OF SNOW INTO SEVERAL SITES.
OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
RESTRICTIONS WILL CONTINUE INTO THURSDAY BEHIND THE COLD FRONT.
PERIODIC RESTRICTIONS ARE THEN LIKELY INTO THE WEEKEND WITH A SERIES
OF DISTURBANCES.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15/33
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1251 AM EST WED FEB 11 2015
.SYNOPSIS...
A LATE DAY COLD FRONT WILL BEGIN THE TRANSITION TO FRIGID TEMPERATURES
WHICH WILL PERSIST FOR THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
THE POST MIDNIGHT UPDATE FEATURED ONLY MINOR ADJUSTMENTS AS STRATUS
OVER NORTHERN AND EASTERN ZONES PERSISTS UNDER A SHARP INVERSION.
SUBSIDENCE UNDER A BUILDING RIDGE HAS KEPT SKIES MOSTLY CLEAR
ELSEWHERE.
OVERALL...A SOFT DAY IS ANTICIPATED FOR THE UPPER OHIO REGION AS A
STRONG SHORTWAVE TROUGH...WITH AXIS OVER THE UPPER MISSISSIPPI
VALLEY THIS MORNING...PROGRESSES OVER THE GREAT LAKES. WARM
ADVECTION IN ADVANCE OF THAT SYSTEM SHOULD SUPPORT HIGHS NEAR THE
MID FEBRUARY AVERAGES DESPITE A CLOUD INCREASE WITH THE MID LEVEL
MOISTURE SURGE. THE TEMPERATURE FORECAST WAS TWEAKED USING THE
LATEST SREF...NAM...AND RAP GUIDANCE TRENDS...BUT CHANGES WERE
MINIMAL.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
THE ACTUAL COLD FRONT PASSAGE IS NOT EXPECTED TO BE DRAMATIC AS
FAR AS PRECIPITATION IS CONCERNED WITH THE LOW CENTER PROJECTED
TOWARD NEW YORK AND A MID LEVEL DRY SLOT RAPIDLY ENCROACHING INTO
UPPER OHIO VALLEY AIRSPACE. HOWEVER...THURSDAY TEMPERATURES WILL
BE ON THE DECLINE...WITH SNOW SHOWER COVERAGE INCREASING UNDER A
FRIGID MID LEVEL THERMAL TROUGH.
THE STEEPENING LOW LEVEL LAPSE RATES AND A SHALLOW DENDRITIC GROWTH
WILL RESULT IN INCREASED CONVECTIVE SNOW SHOWER ACCUMULATION
POTENTIAL...ESPECIALLY IN THE USUAL UPSLOPE AREAS OF THE RIDGES
AND ZONES IN LEE OF THE LAKES. NOT MUCH CHANGE WAS NEEDED FOR THE
ONGOING 1-3 FORECAST WITH 2-4 INCHES ON THE RIDGES.
EASTWARD PROGRESS OF THE MAIN MID LEVEL COLD POOL...I.E. FALLING
INVERSION LEVELS WITH DRY ADVECTION SHOULD RAPIDLY LIMIT ADDITIONAL
ACCUMULATION POTENTIAL ON THURSDAY NIGHT.
THE COLD THURSDAY NIGHT AND FRIDAY TEMPERATURE FORECAST WAS NOT
DISPUTED MUCH BY INCOMING GUIDANCE AS A HIGH AMPLITUDE EASTERN
U.S. UPPER TROUGH DEVELOPS...HENCE CHANGES WERE MINIMAL ALTHOUGH
THE WIND WAS REDONE USING NAM AND GFS GRIDS. WIND CHILL INDICES
STILL ARE PROJECTED INTO THE ADVISORY RANGE OF -10 TO -20C...SO A
HAZARDOUS WEATHER OUTLOOK MENTION WILL BE MAINTAINED WITH A
MENTION OF SNOW ACCUMULATION IN THE RIDGES...WHERE THE BETTER
CHANCE FOR AN ADVISORY IS ON THURSDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
LOW PRESSURE WITH ORIGINS IN THE ARCTIC DROPS SOUTH ACROSS THE
REGION SATURDAY BRINGING A WIDESPREAD LIGHT SNOW. SNOW RATIOS FOR
THIS SYSTEM WILL BE QUITE HIGH 20:1 - 30:1. A FEW INCHES APPEAR
LIKELY...HOWEVER DUE TO TIMING DIFFERENCES TRENDED POPS UPWARD AND
KEPT LIKELY POPS CONFINED TO THE HIGHER TERRAIN FOR THE TIME
BEING.
IN WAKE OF THIS SYSTEM...ANOTHER BLAST OF ARCTIC AIR INVADES THE
UPPER OHIO VALLEY. 850MB TEMPERATURES BOTTOM OUT BETWEEN -24C TO
-26C SUN AFTERNOON WHILE SCATTERED SNOW SHOWERS LINGER WITH THE
EXODUS OF THE MID LEVEL TROUGH. SOUTHWEST WINDS ON THE BACK SIDE OF
THE SURFACE ANTICYCLONE ERADICATES COLD AIR AND A QUICK WARM UP TO
TEMPS ONLY 10 DEGREES BELOW NORMAL IS PROJECTED MONDAY.
TEMPERATURES WERE A WEIGHTED BLEND OF EXISTING FORECAST...GFS MEX
GUIDANCE...AND ECMWF STATISTICAL GUIDANCE.
&&
.AVIATION /05Z WEDNESDAY THROUGH SUNDAY/...
STRATUS WILL CONTINUE OVERNIGHT AT FKL/DUJ/LBE...WITH THE WESTERN
EDGE OF STRATUS CURRENTLY HOVERING JUST EAST OF AGC/MGW. LOW
CONFIDENCE FORECAST IN WHETHER THOSE TWO TERMINALS WILL BE
IMPACTED...BUT HAVE PULLED THE MENTION OF STRATUS PREVIOUSLY IN THE
PIT/BVI/HLG TAFS. MVFR FOG HAS ALSO MOVED INTO ZZV...AND SHOULD
PERSIST THROUGH THE NIGHT. STRATUS SHOULD DIMINISH IN COVERAGE AFTER
SUNRISE...ALTHOUGH FKL/DUJ COULD POTENTIALLY STAY IN THE STRATUS
THROUGH THE TAF PERIOD. HAVE GONE MORE PESSIMISTIC THAN PREVIOUS
TAFS FOR THOSE TWO SITES. COLD FRONT PUSHES THROUGH THE REGION THIS
EVENING...BRINGING RESTRICTIONS AND A SHIFT IN THE WINDS. STILL
UNSURE OF HOW LOW VISIBILITIES WILL DROP WITH SNOW SHOWERS...BUT
HAVE AT LEAST BROUGHT A MENTION OF SNOW INTO SEVERAL SITES.
OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
RESTRICTIONS WILL CONTINUE INTO THURSDAY BEHIND THE COLD FRONT.
PERIODIC RESTRICTIONS ARE THEN LIKELY INTO THE WEEKEND WITH A SERIES
OF DISTURBANCES.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15/33
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
419 AM EST WED FEB 11 2015
.UPDATE...
ISSUED AT 945 PM EST TUE FEB 10 2015
FCST NOT QUITE GOING AS PLANNED AS IT LOOKS LIKE SNOWFALL AMOUNTS
ARE GOING TO FALL SHORT OF ADVY CRITERIA BASED ON RADAR IMAGERY/OBS
AND TRENDS. HAVE CUT SNOW AMOUNTS DOWN TO MOSTLY 1-2 INCHES FOR THE
TONIGHT PERIOD...NOT ADVY WORTHY AMOUNTS. A FEW SPOTS MAY REACH 3.
THOSE HIGHER AMOUNTS MAY BE FOUND OVER THE KEWEENAW AND PERHAPS SOME
PORTIONS OF SCNTRL UPPER MI...CLOSER TO VORT MAX AND MORE
CONSOLIDATED SNOW AREA MOVING ACROSS WI. BIGGER CHANGE WAS TO ADD
-FZDZ INTO THE FCST BASED LARGELY ON UPSTREAM OBS...BUT ALSO BASED
ON SOME HINTS IN FCST SOUNDINGS THAT THERE WILL BE A LOSS OF ICE
CRYSTALS. WILL LET ADVY PLAY OUT WITH THE INTRODUCTION OF
-FZDZ. THAT SAID...SINCE IT WILL HAVE SNOWED BEFORE -FZDZ
OCCURS...IMPACT OF THE -FZDZ ON ROADWAYS WILL LIKELY BE MUCH MORE
LIMITED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 353 PM EST TUE FEB 10 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A POLAR BRANCH WNW
FLOW ALOFT OVER THE UPPER GREAT LKS BTWN AN ARCTIC BRANCH FARTHER N
IN CANADA AND A SUBTROPICAL BRANCH OVER THE SRN CONUS. SHRTWV
EMBEDDED IN THIS POLAR BRANCH FLOW IS MOVING ESE TOWARD WRN MN...
CAUSING 12HR H3 HGT FALLS UP TO 120M. ACCOMPANYING AREA OF PCPN IS
OVER MN UNDER AREA OF DEEPER MSTR ENHANCED BY UPR DVGC AHEAD OF THIS
FEATURE AS WELL AS WAA/ISENTROPIC ASCENT BEST SHOWN ON THE 290-300K
SFCS /ABOUT H6-75/ AND SPREADING TO THE NE TOWARD THE WRN CWA.
AHEAD OF THIS PCPN...SKIES OVER UPR MI ARE MAINLY CLDY WITH MOIST
LLVL AIRMASS TRAPPED UNDER SHARP INVRN BASE ARND H9. THERE HAS BEEN
SOME PATCHY LIGHT FREEZING DZ IN AREAS OVER THE KEWEENAW/NCENTRAL
WHERE LLVL ESE FLOW UPSLOPES.
MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON SN AMOUNTS
ASSOCIATED WITH INCOMING SHRTWV AND GOING HEADLINES.
LATE TODAY/TNGT...AS AREA OF ISENTROPIC ASCENT/UPR DVGC/DEEP LYR
QVECTOR CNVGC IN ADVANCE OF SHRTWV MOVING THRU MN PUSHES INTO THE
CWA...EXPECT SN TO OVERSPREAD THE AREA W-E. MODELS ARE INDICATING
A 9-12 HR PERIOD OF FORCING BEFORE THE ARRIVAL OF SOME DEEP LYR
QVECTOR DVGC/DNVA OVER THE W LATE IN THE WAKE OF THE SHRTWV/SFC LO
MOVING OVER CENTRAL UPR MI/NRN LK SUP BY 12Z WED. BUT SOME LINGERING
DRY AIR JUST ABOVE THE INVRN BASE WL HINDER THE DEVELOPMENT OF
STEADIER PCPN...ESPECIALLY IN AREAS THAT EXPERIENCE A DOWNSLOPE
WIND COMPONENT WITH ONGOING S FLOW...SO THE ACTUAL WINDOW FOR
STEADIER SN WL ACTUALLY BE 6-9 HRS. MODELS INDICATE ABOUT 2.5 G/KG
SPECIFIC HUMIDITY WL BE PRESENT ON THE 290K SFC ARND H7...WHICH
WOULD SUPPORT GOING FCST UP 3 TO 4 INCHES OF SNOW DURING THE 6-9 HR
WINDOW OF STEADY PCPN. ABSENCE OF ANY PHASING WITH THE ARCTIC/
SUBTROPICAL BRANCES AND SHARPER UPR DVGC ASSOCIATED WITH THE JET
CORES IN THOSE BRANCHES AS WELL AS FCST HI THIN DGZ THAT WL LIMIT
SN/WATER RATIOS WL LIMIT SN TOTALS. LATE TNGT...EXPECT THE PCPN OVER
THE W TO DIMINISH FOR AT LEAST A TIME FOLLOWING THE EXIT OF THE DEEP
UPR FORCING AND PASSAGE OF LO PRES TROF ACCOMPANYING SFC LO MOVING
THRU NRN LK SUP. THE INCOMING AIRMASS WL BE INITIALLY TOO WARM TO
SUPPORT LES. GOING HEADLINES APPEAR TO BE IN GOOD SHAPE. DID ADD
LUCE COUNTY TO THE HEADLINE MIX WITH ARND 3 INCHES EXPECTED THERE
BEFORE THE SN DIMINISHES LATER ON WED MRNG.
WED...LINGERING STEADY SN OVER THE ERN CWA SHOULD END IN THE MRNG
WITH THE PASSAGE OF SHRTWV/ACCOMPANYING SFC LO PRES TROF AND EXIT OF
DEEP LYR QVECTOR CNVGC. GUIDANCE THEN SHOWS AN ARCTIC BRANCH SHRTWV
DIGGING SHARPLY TO NEAR WRN LK SUP BY 00Z THU...WITH H85 TEMPS
FALLING TOWARD -21C OVER THE NW CWA BY 00Z THU FOLLOWING ATTENDANT
COLD FROPA. NNW H925 WINDS INCRSG UP TO 30-35KTS IN THE SHARP CYC
FLOW LEFT IN THE WAKE OF THIS DISTURBANCE AND DEEPENING LO PRES
EXITING TO THE E IN THE STRONG CAA WL RESULT IN VERY GUSTY SFC WINDS
THAT WL AT LEAST APRCH ADVY LEVELS AS WELL AS CONSIDERABLE BLSN IN
ADDITION TO THE LES IN EXPOSED AREAS NEAR LK SUP. THE COMBINATION OF
THE SHARP CYC FLOW AS WELL AS SOME DPVA/DEEP LYR QVECTOR CNVGC/
DEEPENING MSTR WITH THE STRONG CAD MAY BRING A PERIOD OF SOME LK
ENHANCED SN LATE IN THE DAY OVER THE W. LATER SHIFTS WL
NEED TO INCLUDE ADDITIONAL HEADLINES FOR AT LEAST AREAS NEAR LK SUP
FOR LATER WED.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 419 AM EST WED FEB 11 2015
NAM SHOWS A DEEP 500 MB TROUGH OVER THE GREAT LAKES REGION 12Z THU
WITH A 500 MB RIDGE ON THE WEST COAST. PATTERN CHANGES LITTLE FOR
12Z FRI. A CLOSED 500 MB LOW HEADS SOUTH OUT OF HUDSON BAY FRI NIGHT
AND DIGS A DEEP TROUGH INTO THE UPPER GREAT LAKES 12Z SAT. AN
ALBERTA CLIPPER SYSTEM MOVES THROUGH THE AREA LATER FRI AFTERNOON
AND EVENING AND THE NAM HAS SOME 850-500 MB Q-VECTOR CONVERGENCE AND
DEEPER MOISTURE MOVE THROUGH THE CWA FRI BEFORE MOVING OUT FRI
NIGHT.
DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST AS PREVIOUS
FORECAST SEEMED TO HAVE THINGS WELL IN HAND. LAKE EFFECT SNOW
CONTINUES INTO THU WITH WINDS DECREASING DURING THE MORNING. WILL
CONTINUE WITH THE ADVISORIES INTO THU FOR THE SNOW AND BLOWING SNOW.
CLIPPER SYSTEM FOR FRI HAS WINDS INCREASING FRI NIGHT AND SNOW
AMOUNTS DO NOT LOOK REAL IMPRESSIVE...BUT WILL GET SOME BLOWING AND
DRIFTING OF SNOW AGAIN FRI NIGHT INTO SAT.
IN THE EXTENDED...GFS AND ECMWF SHOW A CLOSED 500 MB LOW OVER THE
UPPER GREAT LAKES 12Z SAT WITH COLD AIR MOVING ACROSS THE AREA. 850
MB TEMPERATURES ACROSS LAKE SUPERIOR ARE FROM -25C TO -30C AT THAT
TIME. THIS 500 MB TROUGH MOVES TO THE EASTERN U.S. 12Z SUN WITH SFC
HIGH PRESSURE OVER THE AREA. A COLD FRONT THEN MOVES INTO THE UPPER
GREAT LAKES 12Z MON WITH 850 MB TEMPERATURES AROUND -18C. COOLER AIR
IS AGAIN POISED TO MOVE INTO THE AREA ON TUE. TEMPERATURES WILL
REMAIN WELL BELOW NORMAL THIS FORECAST PERIOD WITH SOME LAKE EFFECT
SNOW BEING THE PREVALENT PCPN TYPE. AN ALBERTA CLIPPER SYSTEM HAS
ALREADY MOVED THROUGH THE AREA ON SAT. WILL HAVE TO CONTEND WITH
WIND CHILL WARNINGS AND ADVISORIES FOR SATURDAY AND WILL MENTION IN
THE HWO FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1157 PM EST TUE FEB 10 2015
AT KIWD/KCMX...EXPECT MVFR CONDITIONS TO GENERALLY BE THE RULE
OVERNIGHT WITH OCNL -SN THAT MAY MIX AT TIMES WITH -FZDZ. WINDS WILL
SHIFT TO AN UPSLOPE W FOLLOWING THE PASSAGE OF A LOW PRES TROF LATE
IN THE NIGHT/EARLY MORNING...AND THIS SHOULD BRING A PERIOD OF IFR
CONDITIONS. COLD FROPA AROUND MID MORNING WILL THEN BRING STRONGER
NW WINDS/LAKE EFFECT SNOW...MAINTAINING IFR CONDITIONS. PASSAGE OF
ANOTHER SFC TROF LATE IN THE AFTN/EARLY EVENING WILL INCREASE LES
AND PROBABLY DROP CONDITIONS TO LIFR IN -SHSN/BLSN.
AT KSAW...EXPECT MVFR CONDITIONS TO FALL TO IFR IN THE NEXT FEW HRS
AS UPSLOPE S WIND CONTINUES. OCNL -SN MAY MIX AT TIMES WITH -FZDZ.
CONDITIONS SHOULD RETURN TO MVFR WITH STRENGTHENING DOWNSLOPE W WIND
VEERING NW FOLLOWING LOW PRES TROF PASSAGE EARLY THIS MORNING AND
THEN COLD FROPA LATER IN THE MORNING. PASSAGE OF ANOTHER SFC TROF
THIS EVENING WILL SIGNIFICANTLY INCREASE LAKE EFFECT SNOW/WINDS AND
BLSN...RESULTING IN CONDITIONS FALLING TO LIFR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 AM EST WED FEB 11 2015
TWO GALE AND HEAVY FREEZING SPRAY EVENTS WILL OCCUR DURING THE
FORECAST PERIOD. THE FIRST WILL BE THROUGH THU AND THE SECOND WILL
BE FRIDAY NIGHT AND SATURDAY. THE STRONGER EVENT WILL BE FRIDAY
NIGHT AND SATURDAY WITH GALES TO 45 KNOTS AND THERE COULD BE SOME
STORM FORCE GUSTS WITH THOSE.
LOW PRESSURE OVER LAKE SUPERIOR THIS MORNING WILL MOVE TO JUST EAST
OF GEORGIAN BAY BY THIS EVENING. STRONG HIGH PRESSURE WILL MOVE INTO
SOUTH CENTRAL CANADA BY THIS EVENING AND WILL MOVE TO THE MID
MISSISSIPPI VALLEY ON THURSDAY AND BUILD A RIDGE ACROSS LAKE
SUPERIOR LATE THURSDAY INTO THURSDAY NIGHT. A LOW PRESSURE SYSTEM
ACROSS MANITOBA THURSDAY NIGHT WILL MOVE SOUTHEASTWARD ACROSS LAKE
SUPERIOR FRIDAY AFTERNOON AND EVENING. ANOTHER STRONG HIGH PRESSURE
ACROSS CENTRAL CANADA SATURDAY MORNING WILL MOVE TO THE UPPER GREAT
LAKES ON SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 10 AM EST
THURSDAY FOR MIZ001>004-084.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST
THURSDAY FOR MIZ013-085.
WINTER WEATHER ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
MIZ006-014-085.
WINTER WEATHER ADVISORY FROM NOON TODAY TO 9 AM CST THURSDAY FOR
MIZ009.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 4 PM EST
THURSDAY FOR MIZ005.
WINTER STORM WARNING FROM 4 PM THIS AFTERNOON TO 7 PM EST
THURSDAY FOR MIZ006.
WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 1 PM EST
THURSDAY FOR LSZ267.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 1 PM EST THURSDAY FOR
LSZ267.
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 7 PM
EST THURSDAY FOR LSZ266.
GALE WARNING FROM 1 PM THIS AFTERNOON TO 4 PM EST THURSDAY FOR
LSZ266.
GALE WARNING FROM 1 PM THIS AFTERNOON TO 1 PM EST THURSDAY FOR
LSZ265.
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 1 PM
EST THURSDAY FOR LSZ264.
GALE WARNING FROM 1 PM THIS AFTERNOON TO 10 AM EST THURSDAY FOR
LSZ264.
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 7 AM
EST THURSDAY FOR LSZ263.
GALE WARNING FROM 1 PM THIS AFTERNOON TO 7 AM EST THURSDAY FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...ROLFSON
SHORT TERM...KC
LONG TERM...07
AVIATION...ROLFSON
MARINE...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1157 PM EST TUE FEB 10 2015
.UPDATE...
ISSUED AT 945 PM EST TUE FEB 10 2015
FCST NOT QUITE GOING AS PLANNED AS IT LOOKS LIKE SNOWFALL AMOUNTS
ARE GOING TO FALL SHORT OF ADVY CRITERIA BASED ON RADAR IMAGERY/OBS
AND TRENDS. HAVE CUT SNOW AMOUNTS DOWN TO MOSTLY 1-2 INCHES FOR THE
TONIGHT PERIOD...NOT ADVY WORTHY AMOUNTS. A FEW SPOTS MAY REACH 3.
THOSE HIGHER AMOUNTS MAY BE FOUND OVER THE KEWEENAW AND PERHAPS SOME
PORTIONS OF SCNTRL UPPER MI...CLOSER TO VORT MAX AND MORE
CONSOLIDATED SNOW AREA MOVING ACROSS WI. BIGGER CHANGE WAS TO ADD
-FZDZ INTO THE FCST BASED LARGELY ON UPSTREAM OBS...BUT ALSO BASED
ON SOME HINTS IN FCST SOUNDINGS THAT THERE WILL BE A LOSS OF ICE
CRYSTALS. WILL LET ADVY PLAY OUT WITH THE INTRODUCTION OF
-FZDZ. THAT SAID...SINCE IT WILL HAVE SNOWED BEFORE -FZDZ
OCCURS...IMPACT OF THE -FZDZ ON ROADWAYS WILL LIKELY BE MUCH MORE
LIMITED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 353 PM EST TUE FEB 10 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A POLAR BRANCH WNW
FLOW ALOFT OVER THE UPPER GREAT LKS BTWN AN ARCTIC BRANCH FARTHER N
IN CANADA AND A SUBTROPICAL BRANCH OVER THE SRN CONUS. SHRTWV
EMBEDDED IN THIS POLAR BRANCH FLOW IS MOVING ESE TOWARD WRN MN...
CAUSING 12HR H3 HGT FALLS UP TO 120M. ACCOMPANYING AREA OF PCPN IS
OVER MN UNDER AREA OF DEEPER MSTR ENHANCED BY UPR DVGC AHEAD OF THIS
FEATURE AS WELL AS WAA/ISENTROPIC ASCENT BEST SHOWN ON THE 290-300K
SFCS /ABOUT H6-75/ AND SPREADING TO THE NE TOWARD THE WRN CWA.
AHEAD OF THIS PCPN...SKIES OVER UPR MI ARE MAINLY CLDY WITH MOIST
LLVL AIRMASS TRAPPED UNDER SHARP INVRN BASE ARND H9. THERE HAS BEEN
SOME PATCHY LIGHT FREEZING DZ IN AREAS OVER THE KEWEENAW/NCENTRAL
WHERE LLVL ESE FLOW UPSLOPES.
MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON SN AMOUNTS
ASSOCIATED WITH INCOMING SHRTWV AND GOING HEADLINES.
LATE TODAY/TNGT...AS AREA OF ISENTROPIC ASCENT/UPR DVGC/DEEP LYR
QVECTOR CNVGC IN ADVANCE OF SHRTWV MOVING THRU MN PUSHES INTO THE
CWA...EXPECT SN TO OVERSPREAD THE AREA W-E. MODELS ARE INDICATING
A 9-12 HR PERIOD OF FORCING BEFORE THE ARRIVAL OF SOME DEEP LYR
QVECTOR DVGC/DNVA OVER THE W LATE IN THE WAKE OF THE SHRTWV/SFC LO
MOVING OVER CENTRAL UPR MI/NRN LK SUP BY 12Z WED. BUT SOME LINGERING
DRY AIR JUST ABOVE THE INVRN BASE WL HINDER THE DEVELOPMENT OF
STEADIER PCPN...ESPECIALLY IN AREAS THAT EXPERIENCE A DOWNSLOPE
WIND COMPONENT WITH ONGOING S FLOW...SO THE ACTUAL WINDOW FOR
STEADIER SN WL ACTUALLY BE 6-9 HRS. MODELS INDICATE ABOUT 2.5 G/KG
SPECIFIC HUMIDITY WL BE PRESENT ON THE 290K SFC ARND H7...WHICH
WOULD SUPPORT GOING FCST UP 3 TO 4 INCHES OF SNOW DURING THE 6-9 HR
WINDOW OF STEADY PCPN. ABSENCE OF ANY PHASING WITH THE ARCTIC/
SUBTROPICAL BRANCES AND SHARPER UPR DVGC ASSOCIATED WITH THE JET
CORES IN THOSE BRANCHES AS WELL AS FCST HI THIN DGZ THAT WL LIMIT
SN/WATER RATIOS WL LIMIT SN TOTALS. LATE TNGT...EXPECT THE PCPN OVER
THE W TO DIMINISH FOR AT LEAST A TIME FOLLOWING THE EXIT OF THE DEEP
UPR FORCING AND PASSAGE OF LO PRES TROF ACCOMPANYING SFC LO MOVING
THRU NRN LK SUP. THE INCOMING AIRMASS WL BE INITIALLY TOO WARM TO
SUPPORT LES. GOING HEADLINES APPEAR TO BE IN GOOD SHAPE. DID ADD
LUCE COUNTY TO THE HEADLINE MIX WITH ARND 3 INCHES EXPECTED THERE
BEFORE THE SN DIMINISHES LATER ON WED MRNG.
WED...LINGERING STEADY SN OVER THE ERN CWA SHOULD END IN THE MRNG
WITH THE PASSAGE OF SHRTWV/ACCOMPANYING SFC LO PRES TROF AND EXIT OF
DEEP LYR QVECTOR CNVGC. GUIDANCE THEN SHOWS AN ARCTIC BRANCH SHRTWV
DIGGING SHARPLY TO NEAR WRN LK SUP BY 00Z THU...WITH H85 TEMPS
FALLING TOWARD -21C OVER THE NW CWA BY 00Z THU FOLLOWING ATTENDANT
COLD FROPA. NNW H925 WINDS INCRSG UP TO 30-35KTS IN THE SHARP CYC
FLOW LEFT IN THE WAKE OF THIS DISTURBANCE AND DEEPENING LO PRES
EXITING TO THE E IN THE STRONG CAA WL RESULT IN VERY GUSTY SFC WINDS
THAT WL AT LEAST APRCH ADVY LEVELS AS WELL AS CONSIDERABLE BLSN IN
ADDITION TO THE LES IN EXPOSED AREAS NEAR LK SUP. THE COMBINATION OF
THE SHARP CYC FLOW AS WELL AS SOME DPVA/DEEP LYR QVECTOR CNVGC/
DEEPENING MSTR WITH THE STRONG CAD MAY BRING A PERIOD OF SOME LK
ENHANCED SN LATE IN THE DAY OVER THE W. LATER SHIFTS WL
NEED TO INCLUDE ADDITIONAL HEADLINES FOR AT LEAST AREAS NEAR LK SUP
FOR LATER WED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 348 PM EST TUE FEB 10 2015
STEADY N TO NNE WINDS WILL ALREADY BE SET UP AT 00Z THURSDAY...WITH
THE SFC LOW OVER NE LAKE HURON. MUCH OF WEDNESDAY NIGHT WILL BE
MARKED BY STRONG WINDS WITH GUSTS ON THE ORDER OF 30-40KTS. THERE IS
A POCKET OF 35-40KT WINDS BETWEEN 925 AND 800MB FROM 00Z-12Z
THURSDAY. THERE WILL DEFINETLY BE A NON-DIURNAL TREND TO THE WINDS.
WINDS WILL REMAIN OUT OF THE N THROUGH 12Z SUNDAY...ALTHOUGH WEAKEN
SIGNIFICANTLY LATE SATURDAY NIGHT/EARLY SUNDAY MONRING. IT WILL BE
AN EXTENDED PERIOD OF LAKE EFFECT SNOW SHOWERS...THAT WHEN
ACCOMPANIED WITH THE WIND AND THE SNOW ALREADY ON THE GROUND...WILL
RESULT IN SHARPLY REDUCED VISIBILITIES. HEADLINES WILL EVENTUALLY BE
POSTED FOR THIS PERIOD TO NOT ONLY HIGHLIGHT THE 2-4IN OF SNOW FROM
WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT...BUT THE BLOWING SNOW
SHARPLY REDUCING VIS. WILL CONTINUE TO HIGHLIGHT THIS PERIOD IN THE
HWO...WITH THE MAIN FOCUS OF THE SNOW AND BLOWING SNOW BEING ALONG
LAKE SUPERIOR...AND MAINLY FROM THE HURON MOUNTAINS THROUGH MUNISING
AND GRAND MARIAS.
BY DAYBREAK THURSDAY THE SFC WILL HAVE SHIFTED TO NY AND THE STRONG
1048-1052MB/30.9IN HIGH WILL HAVE SLIPPED INTO THE DAKOTAS. THE
PRESSURE GRADIENT WILL WEAKEN DURING THE AFTERNOON HOURS AS THE HIGH
WEAKENS SLIGHTLY ACROSS IA.
EXPECT THE SFC RIDGE TO EXTEND DIRECTLY OVER THE CWA 00-06Z
FRIDAY...BRINGING THE LIGHTEST WINDS OF THE PERIOD AND SHIFTING
LINGERING LES OVER E ALGER AND SCHOOLCRAFT/W LUCE COUNTIES FROM LATE
AFTERNOON THROUGH THE EVENING HOURS. OFFSHORE WINDS WILL TAKE HOLD
ACROSS ALL OF N UPPER MI BY 12Z FRIDAY.
QUICK ON THE HEALS OF THIS PAST SYSTEM...THE NEXT SFC LOW OVER THE W
HALF OF ONTARIO AT 12Z FRIDAY SHOULD CROSS N/CENTRAL LAKE SUPERIOR
BY MID DAY...AND DEEPEN OVER E LAKE SUPERIOR/UPPER MI BY 00Z
SATURDAY. A LIMITED PERIOD OF WAA WILL MEAN THAT 850MB TEMPS WILL
ONLY RISE TO AROUND -18C FRIDAY MORNING-EARLY AFTERNOON. AFTER THE
PASSAGE OF THE LOW LOOK FOR THE -20 TO -25C 850MB AIR TO FILTER BACK
IN. UNLIKE THE PAST COUPLE OF EVENTS...FREEZING DRIZZLE ON THE ONSET
WILL NOT BE A CONCERN.
NW WINDS WILL BE PICKING UP ACROSS THE W HALF OF UPPER MY BY AROUND
21Z...AND INCREASE ACROSS THE ENTIRE CWA OVERNIGHT TURNING FROM OUT
OF THE NW TO N AS THE SFC LOW EXITS ACROSS LAKE HURON AND THE COLD
AIR SETTLES IN WITH THE 500MB LOW OVER CENTRAL ONTARIO AT 06Z
SATURDAY SINKING OVER CENTRAL/E UPPER MI AROUND 12Z. -25 TO -35C AIR
WILL BE OVER THE W HALF BY 12Z SATURDAY /COLDEST OFF THE 10/12Z RUN
OF THE GFS/. EXPECT COLD AND BLUSTERY CONDITIONS LATE FRIDAY NIGHT
THROUGH SATURDAY!
AS PREVIOUSLY STATED...THE FIRST WAVE OF LAKE EFFECT AND STRONG
WINDS WEDNESDAY NIGHT AND THURSDAY WILL GIVE A GOOD FEEL TO WHAT
WILL HAPPEN FRIDAY NIGHT INTO SATURDAY. AT THIS POINT EXPECT
CONDITIONS TO BE WORSE THAN THE FIRST WAVE AND THERE WILL LIKELY BE
A PERIOD OF BLIZZARD CONDITIONS FOR THE FAVORED MARQUETTE-MUNISING
STRETCH AND PERSONS WILL LIKELY NEED TO PLAN FOR THE POSSIBILITY OF
M-28 BEING CLOSED.
WIND CHILL READINGS SATURDAY MORNING WILL FALL TO -15 TO -25F
SATURDAY MORNING AS THE STRONG WINDS COMBINE WITH LOWS AROUND 0F.
LOOK FOR SOME MODERATION TO THE VERY COLD AIR ALOFT SUNDAY...BUT
STILL AROUND -20 TO -25C THROUGH THE DAY SUNDAY. THERE IS SOME
DISCREPANCIES IN THE LOCAL WIND SHIFTS ACROSS LAKE SUPERIOR
SUNDAY...BUT THE TREND WILL BE IMPROVING CONDITIONS EITHER WAY AS
THE SFC HIGH SHIFTS OVERHEAD SUNDAY AND EXITS E SUNDAY
AFTERNOON/EVENING. THE NEXT GOOD CHANCE OF SNOW FOR LATE MONDAY
NIGHT/TUESDAY DOESN/T LOOK TOO IMPRESSIVE OFF THE ECMWF...BUT MORE
DYNAMIC OFF THE GFS. A BLENDED MODEL SOLUTION SEEMS REASONABLE AT
THIS POINT...AS THE MAIN CONCERS AND FOCUS FOR THIS FCST PERIOD ARE
RIGHT AT THE BEGINING AND THEN FRIDAY NIGHT THROUGH SATURDAY
MORNING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1157 PM EST TUE FEB 10 2015
AT KIWD/KCMX...EXPECT MVFR CONDITIONS TO GENERALLY BE THE RULE
OVERNIGHT WITH OCNL -SN THAT MAY MIX AT TIMES WITH -FZDZ. WINDS WILL
SHIFT TO AN UPSLOPE W FOLLOWING THE PASSAGE OF A LOW PRES TROF LATE
IN THE NIGHT/EARLY MORNING...AND THIS SHOULD BRING A PERIOD OF IFR
CONDITIONS. COLD FROPA AROUND MID MORNING WILL THEN BRING STRONGER
NW WINDS/LAKE EFFECT SNOW...MAINTAINING IFR CONDITIONS. PASSAGE OF
ANOTHER SFC TROF LATE IN THE AFTN/EARLY EVENING WILL INCREASE LES
AND PROBABLY DROP CONDITIONS TO LIFR IN -SHSN/BLSN.
AT KSAW...EXPECT MVFR CONDITIONS TO FALL TO IFR IN THE NEXT FEW HRS
AS UPSLOPE S WIND CONTINUES. OCNL -SN MAY MIX AT TIMES WITH -FZDZ.
CONDITIONS SHOULD RETURN TO MVFR WITH STRENGTHENING DOWNSLOPE W WIND
VEERING NW FOLLOWING LOW PRES TROF PASSAGE EARLY THIS MORNING AND
THEN COLD FROPA LATER IN THE MORNING. PASSAGE OF ANOTHER SFC TROF
THIS EVENING WILL SIGNIFICANTLY INCREASE LAKE EFFECT SNOW/WINDS AND
BLSN...RESULTING IN CONDITIONS FALLING TO LIFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 348 PM EST TUE FEB 10 2015
THE GALE WATCH FOR WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING WILL
BE UPGRADED TO A GALE WARNING. HEAVY FREEZING SPRAY WARNING WILL BE
NEEDED.
A RIDGE STRETCHING FROM JAMES BAY TO THE LOWER GREAT LAKES WILL
SHIFT E ACROSS QUEBEC TONIGHT. MEANWHILE...A TROUGH ACROSS THE UPPER
MS VALLEY WILL MOVE ACROSS LAKE SUPERIOR LATE TONIGHT AND WEDNESDAY
MORNING. THE LOW WILL CONTINUE E ACROSS THE LOWER GREAT LAKES
THROUGH WEDNESDAY NIGHT AS A TROUGH REMAINS ACROSS LOWER MI. A HIGH
ACROSS S CENTRAL CANADA WEDNESDAY WILL MOVE TO THE MID MS VALLEY ON
THURSDAY AND BUILD A RIDGE ACROSS LAKE SUPERIOR LATE THURSDAY INTO
THURSDAY NIGHT. IN BETWEEN THE EXITING LOW AND NEARING HIGH...N
GALES OF 35 TO 45 KNOTS ACROSS CENTRAL AND EASTERN LAKE SUPERIOR
LATE WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING.
LOOK FOR A LOW ACROSS MANITOBA THURSDAY NIGHT TO SINK ACROSS LAKE
SUPERIOR FRIDAY AFTERNOON AND EVENING...AND THE CENTRAL APPALACHIANS
SATURDAY AFTERNOON...WHILE A LARGE HIGH NEARS FROM SOUTH CENTRAL
CANADA AND THE NORTHERN PLAINS. THIS WILL BRING ABOUT ANOTHER ROUND
OF N GALES OF 35 TO 45 KNOTS AND HEAVY FREEZING SPRAY IS POSSIBLE
FRIDAY NIGHT THROUGH SATURDAY...MAINLY OVER CENTRAL AND EASTERN LAKE
SUPERIOR. EXPECT THE HIGH TO DRIFT ACROSS THE UPPER GREAT LAKES ON
SUNDAY...WITH MUCH LIGHTER WINDS TAKING HOLD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 7 AM EST /6 AM CST/ WEDNESDAY FOR
MIZ001-003>006-010-011-013-014-084-085.
WINTER WEATHER ADVISORY UNTIL 4 AM EST /3 AM CST/ WEDNESDAY FOR
MIZ002-009.
WINTER WEATHER ADVISORY UNTIL 10 AM EST WEDNESDAY FOR MIZ007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM WEDNESDAY TO 1 PM EST
THURSDAY FOR LSZ267.
GALE WARNING FROM 4 PM WEDNESDAY TO 1 PM EST THURSDAY FOR LSZ267.
HEAVY FREEZING SPRAY WARNING FROM 1 PM WEDNESDAY TO 7 PM EST
THURSDAY FOR LSZ266.
GALE WARNING FROM 1 PM WEDNESDAY TO 4 PM EST THURSDAY FOR LSZ266.
GALE WARNING FROM 1 PM WEDNESDAY TO 1 PM EST THURSDAY FOR LSZ265.
HEAVY FREEZING SPRAY WARNING FROM 1 PM WEDNESDAY TO 1 PM EST
THURSDAY FOR LSZ264.
GALE WARNING FROM 1 PM WEDNESDAY TO 10 AM EST THURSDAY FOR
LSZ264.
HEAVY FREEZING SPRAY WARNING FROM 1 PM WEDNESDAY TO 7 AM EST
THURSDAY FOR LSZ263.
GALE WARNING FROM 1 PM WEDNESDAY TO 7 AM EST THURSDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...ROLFSON
SHORT TERM...KC
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KF
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
933 PM MST TUE FEB 10 2015
.UPDATE...
JUST MADE SOME MINOR FORECAST ADJUSTMENTS THIS EVENING. RADAR
SHOWED PRECIPITATION HAD JUST ABOUT EXITED THE SW PORTION OF THE
REGION THIS EVENING...BUT JET FORCING AND WEAK WARM ADVECTION WERE
CAUSING ADDITIONAL LIGHT SNOW SHOWERS TO DEVELOP IN N CENTRAL MT.
THESE SNOW SHOWERS WERE MOVING S INTO THE FORECAST AREA. MODELS
DRIED OUT THE REGION AFTER 06Z...THEN SHOWED SOME PRECIPITATION
FORMING ALONG A SECONDARY SURGE OF COLDER AIR INTO THE NE PART OF
THE AREA WED MORNING. ADJUSTED POPS THROUGH 06Z TO FIT RADAR
TRENDS...THEN DRIED OUT 06-12Z. ON WED MORNING...SHIFTED THE LOW
POPS FURTHER E TO COVER KBHK...BROADUS AND EKALAKA AND WENT WITH A
SNOW/LIGHT FREEZING DRIZZLE MIX BASED ON RAP SOUNDINGS. SATELLITE
IMAGERY AND SURFACE OBSERVATIONS SHOWED A GOOD DEAL OF LOW TO
MID CLOUDS OVER THE AREA WHICH SHOULD KEEP FOG FROM DEVELOPING IN
MOST AREAS. DID ADD PATCHY FOG TO JUDITH GAP WHERE RH WAS AT 100
PERCENT. TEMPERATURES AND WINDS WERE IN GOOD SHAPE. ARTHUR
&&
.SHORT TERM...VALID FOR WED AND THU...
COLDER AIR OVER EASTERN AND NORTHERN MONTANA PUSHING INTO
SOUTH CENTRAL MONTANA BUT NORTHWEST FLOW ALOFT AND UNSTABLE
CONDITIONS KEEPING THE AIRMASS MIXED AND TEMPERATURES ARE SLOW TO
FALL. INSTABILITY BEING UNLEASHED BY THE LIFT FROM THE COLD AIR
PUSH IS PRODUCING SHOWER ACTIVITY BUT RADAR IS SHOWING THIS
PROCESS IT MOST INTENSE FOR THE BILLINGS AREA RIGHT NOW WITH KTFX
RADAR SHOWING A DRYING TREND UPSTREAM. HAVE LOWERED POPS FOR THE
EVENING BECAUSE ACTIVITY IS BEEN REALLY LIMITED IN COVERAGE SO
FAR. ONLY EXPECT AN INCH IN THE FOOTHILLS WITH ONLY A BRIEF SNOW
SHOWER OR SNOW PELLETS IN THE PLAINS EARLY THIS EVENING. THIS
ACTIVITY WILL CONTINUE TO DECREASE OVERNIGHT BUT ENOUGH MOISTURE
AROUND AS THE COLD AIR DEEPENS TO KEEP SOME FLURRIES AROUND.
SECONDARY PUSH OF COLDER AIR INTO NORTHEAST MONTANA AND THE
DAKOTAS ON WEDNESDAY WITH A WEAK BIT OF MID LEVEL WARM AIR
ADVECTION WILL ALLOW THE AIRMASS TO STAY MOIST OVER AN AREA EAST
OF BILLINGS OVER TO MILES CITY. THIS WILL ALLOW THE FLURRY
ACTIVITY TO CONTINUE. FURTHER WEST THE AIRMASS STAYS DRIER BUT
EASTERLY SURFACE WINDS WILL KEEP TEMPERATURES COOL...AT LEAST BY
FEBRUARY 2015 STANDARDS.
WEDNESDAY NIGHT THE COLD AIR RETREATS AND A SURFACE TROUGH FORMS
ALONG THE FRONT RANGE OF THE ROCKIES AS THE RIDGE AXIS OVER THE
PACIFIC NORTHWEST WEAKENS. THIS WILL ALLOW GAP FLOW WINDS TO BEGIN
DEVELOPING FOR THE LIVINGSTON AND NYE AREAS BUT LACK OF MID LEVEL
SUPPORT AND ONLY MODERATE PRESSURE GRADIENTS SHOULD LIMIT WIND
SPEEDS SO DO NOT ANTICIPATE ADVISORY LEVEL WINDS AT THIS TIME. BY
LATE WEDNESDAY NIGHT THIS SURFACE TROUGH BEGINS AN EASTWARD
MIGRATION AND MODERATING DOWNSLOPE WINDS CAN BE EXPECTED IN THE
CENTRAL ZONES. THE MOISTURE WHICH HAD BEEN SUPPORTING FLURRIES
SHIFTS EASTWARD INTO THE DAKOTAS BRINGING AN END TO THE FLURRIES.
THURSDAY WILL SEE TEMPERATURES RISE BUT SURFACE WINDS WILL BE
NORTHWESTERLY AS MID LEVEL MOMENTUM MIXES DOWN. THIS WILL SUPPORT
TEMPERATURES WELL INTO THE 50S ESPECIALLY AS CLOUD COVER DECREASES
ALLOWING SOME DIURNAL WARMING. A LIGHT WESTERLY DOWNSLOPE CAN BE
EXPECTED THURSDAY NIGHT AS STRONGER SURFACE HIGH PRESSURE FORMS
OVER WESTERN MONTANA BUT GRADIENTS WILL BE FAIRLY LIGHT. LOOKS DRY
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT ACROSS THE AREA. BORSUM
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
EXTENDED PERIOD BEGINS FRIDAY WITH THE WESTERN US UNDER THE
INFLUENCE OF AN UPPER LEVEL RIDGE. HIGHER HEIGHTS WILL BE ACTING
TO KEEP TEMPERATURES FAIRLY WARM FOR MID FEBRUARY ACROSS THE
CWA...WELL INTO THE UPPER 50S AT MOST LOCATIONS.
BY SATURDAY...UPPER LEVEL ENERGY OFF THE WEST COAST WILL BREAK
DOWN THE ENTRENCHED RIDGE AND USHER IN UNSETTLED NORTHWESTERLY FLOW.
THERE IS A BIT OF MODEL UNCERTAINTY WITH THE SYSTEM EARLY NEXT
WEEK...MAINLY IN THE FORM OF TEMPERATURES. IT WILL DEFINITELY BE
COLDER THAN IT HAS BEEN WITH SOME SNOW...BUT TOO EARLY TO SAY JUST
HOW COLD AND HOW MUCH. SINGER
&&
.AVIATION...
MVFR CONDITIONS WILL PREVAIL ACROSS CENTRAL AND EASTERN PORTIONS
OF THE REGION INTO WEDNESDAY MORNING WITH LOW CEILINGS.
OTHERWISE...VFR CONDITIONS WILL PREVAIL. FRIEDERS
&&
.PRELIMINARY POINT TEMP/POPS...
WED THU FRI SAT SUN MON TUE
-----------------------------------------------------------
BIL 026/043 030/059 038/062 037/058 037/051 030/038 016/029
21/B 00/N 00/B 00/B 11/B 34/J 42/J
LVM 030/052 036/056 039/061 040/058 037/053 031/041 018/033
20/B 00/N 11/B 11/B 01/B 44/W 42/J
HDN 023/041 025/059 032/061 030/056 031/052 027/037 012/027
21/B 00/E 00/B 00/B 11/B 34/J 42/J
MLS 018/030 018/051 029/053 024/044 029/046 025/032 010/023
02/J 00/E 00/B 01/E 11/B 23/J 32/J
4BQ 019/036 021/056 032/058 026/051 030/050 026/036 012/026
12/J 00/E 00/B 01/B 11/B 24/J 31/E
BHK 013/027 010/046 027/048 016/034 024/043 022/030 006/021
12/J 00/E 00/B 01/E 11/N 23/J 31/B
SHR 023/044 023/059 032/059 030/060 031/050 025/036 012/025
21/B 00/E 00/B 00/B 11/B 34/J 42/J
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
348 AM EST WED FEB 11 2015
.SYNOPSIS...
DEEP LOW PRESSURE OFF THE NORTH CAROLINA COAST WILL PULL SLOWLY
AWAY FROM THE FORECAST AREA TODAY. COLD WEATHER TODAY WILL GIVE
WAY TO A VERY BRIEF WARM-UP ON THURSDAY BEFORE THE NEXT ROUND OF
ARCTIC AIR BEGINS TO ARRIVE EARLY THURSDAY EVENING...AND
CONTINUING THROUGH EARLY FRIDAY. AN EVEN COLDER PUSH OF ARCTIC AIR WILL
ARRIVE LATE SATURDAY NIGHT THROUGH SUNDAY. THE CHILL WILL ABATE ON
MONDAY AND MAY GIVE WAY TO THE NEXT BONAFIDE CHANCE FOR
PRECIPITATION ON TUESDAY OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM WEDNESDAY...POWERFUL LOW PRESSURE LOCATED SEVERAL HUNDRED
MILES EAST OF THE OUTER BANKS WILL MOVE FARTHER AWAY FROM THE
CAROLINAS TODAY. THIS WILL ALLOW A SHORTWAVE RIDGE AND A WEAK
SURFACE RIDGE TO MOVE ACROSS THE AREA THIS EVENING.
THERE IS ONE LAST PIECE OF THIS STORM TO DEAL WITH HOWEVER. A STRONG
SUBSIDENCE INVERSION AROUND 925 MB (2500 FEET AGL) HAS TRAPPED
ATLANTIC MOISTURE THROWN BACK AROUND THE STORM ACROSS EASTERN NORTH
CAROLINA. THESE CLOUDS LOOK LIKE THEY WILL BE QUITE PERSISTENT...
POTENTIALLY HANGING AROUND WILMINGTON THROUGH EARLY AFTERNOON BEFORE
CLEARING FINALLY DEVELOPS.
THE WESTERN EDGE OF THESE CLOUDS IS GOING TO BE VERY TOUGH TO PIN
DOWN. THE LATEST RUC SHOWS CLOUDS CROSSING I-95 AND GOING AS FAR
WEST AS DARLINGTON AND BENNETTSVILLE BEFORE STOPPING. (OTHER MODELS
ARE NOT QUITE THIS FAR WEST.) GIVEN THE THIN VERTICAL DEPTH OF THE
CLOUD DECK THE WESTERN EDGE SHOULD FRAGMENT THROUGH VERTICAL MIXING
AND DRYING OF THE BOUNDARY LAYER FROM ALOFT A COUPLE HOURS AFTER
SUNRISE...WITH THE EROSION THEN WORKING ITS WAY BACK EASTWARD TO THE
COAST. WITH THE CLOUDS I HAVE ADJUSTED TEMPERATURES DOWNWARD
ESPECIALLY IN THE BURGAW/WILMINGTON/SOUTHPORT AREA WITH UPPER 40S
EXPECTED HERE. THE REMAINDER OF THE AREA SHOULD REACH 50-55...
WARMEST WEST OF I-95 IN SOUTH CAROLINA.
TONIGHT CLEAR SKIES ARE EXPECTED WITH CALM WINDS AND GOOD
RADIATIONAL COOLING. LOWS SHOULD RANGE FROM THE LOWER TO MIDDLE
30S...COOLEST ACROSS INTERIOR SE NORTH CAROLINA.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...LONGWAVE PATTERN ALOFT TO REMAIN
RELATIVELY UNCHANGED...WITH THE DEEP UPPER TROF AFFECTING THE
EASTERN 1/3RD TO 1/2 OF THE UNITED STATES...AND UPPER RIDGING
ACROSS THE WESTERN 1/3RD TO 1/2 OF THE UNITED STATES. SHORT WAVE
TROFS OR VORTS ALOFT WILL BE ROTATING THRU THIS LONGWAVE UPPER
TROF...KEEPING IT WELL AMPLIFIED DURING THIS TIME PERIOD. THE MEAN
UPPER LONGWAVE TROF NORTH TO SOUTH AXIS IS PROGGED TO REMAIN EITHER
OVERHEAD OR JUST OFF THE EAST COAST. WHAT THIS MEANS FOR THE ILM
CWA IS FOR CONTINUED BELOW OR WELL BELOW NORMAL TEMPS...WITH ONLY
A BRIEF WARM UP PRIOR TO THE PASSAGE OF THE NEXT UPPER S/W TROF...
OR CLIPPER SINCE THEY ORIGINATE ACROSS WEST-CENTRAL CANADA.
AS FOR THIS TIME PERIOD...A BRIEF WARM UP WILL OCCUR DURING
DAYTIME THU AHEAD OF THE NEXT UPPER S/W TROF. THU MAXES MAY
ACTUALLY REACH THE NORM FOR THIS TIME OF THE YEAR. THE MAIN
DYNAMICS OF THIS UPPER S/W TROF TO REMAIN NORTH OF THE FA THU AFTN
AND NIGHT...ALONG WITH THE SFC LOW THAT RE-DEVELOPS AND
INTENSIFIES OFFSHORE FROM THE NEW ENGLAND COAST. ANY DEEP
MOISTURE AVBL FOR PCPN OCCURRENCE TO REMAIN WELL NORTH OF THE FA.
THE SHALLOW MOISTURE THAT WILL BE AVBL WILL BE USED FOR SCT/BKN
CLOUDS AHEAD AND/OR ALONG THE SFC COLD FRONT. LATEST SREF ALSO
INDICATES THAT NO MEASURABLE PCPN TO ACCOMPANY THIS CFP OR THERE-
AFTER. DRYING OF THE ATM COLUMN AND EXCELLENT CAA OR ARCTIC AIR
ADVECTION...UNDER GUSTY NW WINDS WILL OCCUR THU NIGHT INTO FRI AS
THE SFC LOW NEARLY BOMBS WELL OFFSHORE FROM THE NEW ENGLAND COAST
RESULTING IN A WELL TIGHTENED SFC PG ACROSS THE FA.
AS FOR FRI INTO FRI NIGHT...THE CENTER OF THE ARCTIC HIGH WILL BE
LOCATED OVER THE CENTRAL GULF COAST STATES AND THE BOMBING SFC LOW
WILL BE MOVING THRU THE CANADIAN MARITIMES. AS FOR THE ILM
CWA...THE BRUTAL WINDS WILL DIMINISH DURING FRI INTO FRI NIGHT.
SKIES WILL REMAIN RELATIVELY CLEAR WITH A QUIET AND COLD FRI
NIGHT ON TAP.
OVERALL...USED THE NAM MOS GUIDANCE FOR THE NEAR TERM PERIOD
ESPECIALLY WITH DAYTIME HIGHS. FOR EXAMPLE...A NEARLY 1 TO 2
CATEGORY DIFFERENCE EXISTS FOR THE NAM AND GFS MOS GUIDANCE FOR
THU MAX TEMPS ACROSS THE ILM CWA.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...STRATUS BASED AT 2000-2500 FEET AGL WILL AFFECT THE ILM
AIRPORT THROUGH MID-TO-LATE LATE MORNING ACCORDING TO LATEST
HIGH-RES MODELS AND EXTRAPOLATION OF NIGHTTIME SATELLITE IMAGERY.
THIS IS THE BACK EDGE OF MOISTURE SWIRLING AROUND A POWERFUL LOW
SEVERAL HUNDRED MILES OFF THE CAROLINA COAST. VFR CONDITIONS INLAND
ARE EXPECTED THROUGH THE PERIOD...ALTHOUGH SCATTERED LOW STRATUS
(2000 FT AGL) COULD PUSH INTO THE CRE AND LBT AIRPORTS TEMPORARILY
THROUGH DAYBREAK.
SURFACE WINDS NORTH 10 KNOTS ARE EXPECTED...EXCEPT NEAR ILM UNDER
THE CLOUDS WHERE 10-15G25KT IS EXPECTED. SKIES SHOULD CLEAR EVEN AT
ILM BY LATE MORNING WITH VFR CONDITIONS THIS AFTERNOON THROUGH
TONIGHT.
EXTENDED OUTLOOK...EXPECT VFR THROUGH THE EXTENDED PERIOD.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM WEDNESDAY...A POWERFUL STORM CENTERED ALONG 70W OFF THE
NORTH CAROLINA COASTLINE WILL MOVE FARTHER OUT TO SEA TODAY. THE
BELT OF STRONGEST NORTHERLY WINDS SURROUNDING THIS STORM HAS ALREADY
CLEARED THE COASTAL WATERS. FOR THIS REASON THE GALE WARNING HAS
BEEN LOWERED TO A SMALL CRAFT ADVISORY. GRADUALLY DIMINISHING WIND
SPEEDS ARE EXPECTED THROUGH THE DAY. BY TONIGHT WINDS WILL BE LIGHT
FROM THE NW AS A TRANSITORY RIDGE MOVES ACROSS THE AREA. WINDS WILL
THEN BACK AROUND TO THE SW OVERNIGHT BEHIND THE DEPARTING RIDGE.
SEAS MAY TAKE SOME TIME TO DECAY AS AN EASTERLY BACKSWELL CONTINUES
THROUGH TONIGHT. DOMINANT WAVE PERIODS OF 6 TO 7 SECONDS THIS
MORNING WILL SHIFT TO 13 SECONDS THIS AFTERNOON AS THE BACKSWELL
REPLACES LOCAL WIND WAVES AS THE PRIMARY WAVE TRAIN. WAVE PERIODS
THIS LONG BEGIN TO "FEEL" BOTTOM IN WATER DEPTHS OF ~400 FEET...SO
INSIDE THE COASTAL WATERS ZONES (0-20 MILES) SWELL HEIGHTS SHOULD
DIMINISH SUBSTANTIALLY FROM THAT OBSERVED FARTHER OFFSHORE.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...THU STARTS OUT DOCILE FOR BOTH WINDS AND
SEAS ACROSS THE FA...BUT QUICKLY DETERIORATES DURING THE DAY AND
CONTINUING ESPECIALLY THU NIGHT THRU MUCH OF DAYTIME FRI. THIS IN
RESPONSE TO YET ANOTHER CLIPPER LOW THAT DIVES EAST-SOUTHEAST FROM
CANADA TO OFF THE NJ-DEL COAST...THEN RAPIDLY INTENSIFIES OR NEARLY
BOMBS OFF THE NEW ENGLAND COAST THU NIGHT INTO FRI...BEFORE SLOWLY
MOVING NE TO THE CANADIAN MARITIMES BY LATE FRI. THE SFC COLD
FRONT TO PUSH ACROSS THE ILM WATERS LATE THU AFTN OR EARLY
EVENING. THE SFC PG WILL TIGHTEN DRAMATICALLY ACROSS THE AREA
WATERS THU NITE INTO FRI...ACCOMPANIED BY EXCELLENT COLD AIR OR
SHOULD I SAY ARCTIC AIR ADVECTION.
SW-WSW WINDS THU AHEAD OF THE COLD FRONT...WILL VEER TO A GUSTY
GALE FORCE NW WIND FOR THU NIGHT INTO EARLY FRI. A GALE WATCH
LIKLEY WILL BE NEEDED AT THE NEXT FULL UPDATE DURING WED. RIDGING
FROM THE HIGHS CENTER WILL PUSH ACROSS THE LOCAL WATERS LATE FRI
INTO FRI NIGHT ALLOWING BOTH WINDS AND SEAS TO RESPECTIVELY
DIMINISH AND SUBSIDE. AM SOMEWHAT WORRIED THAT WAVEWATCH3 AND SWAN
ARE NOT HANDLING THE BACK GROUND SWELL FROM THE DEEP LOW THAT IS
CURRENTLY PULLING VERY SLOWLY TO THE EAST. MAY ACTUALLY GO ABOVE
GUIDANCE FOR SIGNIFICANT SEAS DURING THU. THE WIND DRIVEN VARIETY
WILL RULE SIG. SEAS COME THU NIGHT THRU FRI.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM WEDNESDAY...
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR AMZ254-256.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ250-
252.
&&
$$
SYNOPSIS...DCH
NEAR TERM...TRA
SHORT TERM...DCH
LONG TERM...DCH
AVIATION...TRA/SGL
MARINE...
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1228 AM EST WED FEB 11 2015
.SYNOPSIS...
STRONG LOW PRESSURE OFF THE NORTH CAROLINA COAST WILL PULL SLOWLY
AWAY FROM THE AREA TODAY. COOL WEATHER WILL GIVE WAY TO A VERY BRIEF
WARMUP ON THURSDAY BEFORE ARCTIC AIR BEGINS TO ARRIVE THURSDAY
EVENING. AN EVEN COLDER PUSH OF ARCTIC AIR WILL ARRIVE ON SUNDAY.
THE CHILL WILL ABATE ON MONDAY AND MAY GIVE WAY TO SOME WET WEATHER
TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 1230 AM WEDNESDAY...BASED ON LATEST RUC AND NAM MODELS PLUS
EXTRAPOLATION OF SATELLITE TRENDS...SKY COVER HAS BEEN ADJUSTED
UPWARDS ACROSS SE NORTH CAROLINA WHERE THE LOW STRATUS DECK WILL
PERSIST THROUGH (AND PERHAPS BEYOND) DAYBREAK. THE BACK EDGE OF THIS
STRATUS DECK MAY EVEN LUNGE WEST AS FAR AS LUMBERTON AND THE MYRTLE
BEACH AREA BEFORE DAYBREAK ALTHOUGH THE ODDS OF ALL-OUT CLOUDY
CONDITIONS ARE QUITE LOW THERE. MINOR ADJUSTMENTS UPWARD TO LOW TEMP
AND WIND SPEED FORECASTS HAVE BEEN MADE FOR THE CLOUDIER AREAS WHERE
RADIATIONAL COOLING WILL NOT OCCUR...LITTLE IF ANY CHANGES HAVE BEEN
MADE ELSEWHERE. DISCUSSION FROM 1030 PM FOLLOWS...
CLOUD COVER HAS BECOME VERY PATCHY WEST OF A LBT TO MYR LINE...WITH
SKIES TOTALLY CLEAR FROM TIME TO TIME. THIS VERY SLOW EROSION OF THE
THICK CLOUD COVER WILL SLOWLY EDGE OFFSHORE THROUGH THE NIGHT.
LOW PRESSURE CONTINUES TO DEEPEN OFF THE COAST WITH LATEST ANALYSIS
NOW SHOWING THE LOW UNDER 991 MB. COMBINATION OF STRENGTHENING LOW
AND HIGH PRESSURE BUILDING SOUTH FROM EASTERN CANADA HAS PINCHED THE
GRADIENT.
BOTH THE SURFACE AND 500 MB LOW WILL PUSH FARTHER EAST TONIGHT...
SLOWLY ALLOWING FOR INCREASED SUBSIDENCE AND AN EROSION OF THE CLOUD
COVER FROM W AND S TO E AND N. FORECAST SOUNDINGS INDICATE
PRECIPITABLE WATER VALUES DROPPING TO LESS THAN ONE-QUARTER OF AN
INCH OVERNIGHT. SOME WRAP AROUND LOW-LEVEL MOISTURE MAY LINGER ALONG
THE CAPE FEAR COAST WELL INTO THE NIGHT AND MOISTURE PROFILES AND
SOME MOS GUIDANCE DO HINT AT THIS POSSIBILITY.
WINDS WILL CONTINUE TO VERY SLOWLY DIMINISH AS THE TIGHTEST OF THE
PRESSURE GRADIENT...ASSOCIATED WITH DEPARTING LOW PRESSURE...PULLS
FURTHER N AND E. WIND SPEEDS INTO LATE EVE...IN THE 15 TO 25 MPH
RANGE...WILL DECREASE TO 10 TO 15 MPH OVERNIGHT. COLD AIR ADVECTION
WILL DICTATE TEMPS...WITH NO SIGNIFICANT RADIATIONAL COOLING...GIVEN
THE BOUNDARY LAYER WILL NOT BE ABLE TO FULLY DECOUPLE...WE EXPECT
WIDESPREAD LOWER 30S BY DAYBREAK.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...LINGERING MOISTURE ALONG THE COAST EARLY
WEDNESDAY MORNING ASSOCIATED WITH LARGE SPINNING GYRE OVER THE
WESTERN ATLANTIC. CLEARING SHOULD BE RAPID HOWEVER AS THE SYSTEM
MOVES OFF THE NORTHEAST WHILE ALSO ENTRAINING DRY AIR ON ITS WESTERN
PERIPHERY. THE SENSE OF LOW LEVEL TEMPERATURE ADVECTION WILL REMAIN
WEAKLY COLD BUT THE RETURN OF SUNSHINE WILL FAVOR HIGHS 50-54. CLEAR
SKIES REMAIN MOST OF WEDNESDAY NIGHT BUT THERE IS JUST ENOUGH WIND
TO PRECLUDE RADIATIONAL COOLING OPTIMIZATION. THURSDAY FEATURES
SUNSHINE FOR MOST OF THE DAY AND A PRE-FRONTAL SOUTHWESTERLY FLOW
WILL BOOST HIGHS ABOVE 60. ARCTIC COLD FRONTAL PASSAGE LIKELY
INDUCES EARLIER THAN NORMAL NON-DIURNAL TEMPERATURE DROPS LATE
AFTERNOON AND EVENING ESPECIALLY INLAND ZONES. VERY STRONG TRAILING
VORT MAX GLANCES BY TO OUR NORTH. IT SHOULD BE STRONG ENOUGH TO
WRING OUT ANY REMAINING MOISTURE...SO LITTLE THAT PRECIPITATION WILL
NOT BE MEASURABLE...BUT SHOULD TAKE THE FORM OF FLURRIES. WHAT FEW
FLAKES DO FALL WILL BE MAINLY CONFINED TO BLADEN AND PENDER
COUNTIES.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...HIGH AMPLITUDE RIDGE IN THE WEST AND TROUGH
IN THE EAST WILL PROVIDE AN AVENUE FOR COLD ARCTIC AIR TO RIDE DOWN
INTO THE SOUTHEAST FRI THROUGH THE WEEKEND. AS COLD FRONT MOVES
FARTHER OUT TO SEA AND HIGH PRESSURE BUILDS IN ON FRI EXPECT PLENTY
OF COLD AND DRY AIR TO MOVE IN. 850 TEMPS WILL BE DOWN NEAR -8C AND
EVEN WITH SUNSHINE...TEMPS WILL STRUGGLE TO MAKE IT TO 40. GUSTY NW
WINDS WILL MAKE IT FEEL LIKE THE 30S FOR HIGH TEMPS. DEEP NW FLOW ON
FRIDAY WILL BACK TOWARD THE WEST LATE FRI THROUGH SAT AS FLOW
FLATTENS A BIT ON THE BOTTOM OF BROAD TROUGH IN THE EAST BEFORE NEXT
SYSTEM BEGINS TO DIG DOWN FROM THE GREAT LAKES BY LATE SAT. WEAK
HIGH PRESSURE AT THE SURFACE OVER THE OHIO VALLEY ON FRI WILL SHIFT
EAST TOWARD THE COAST AND DISSIPATE AND OVERALL GRADIENT WILL RELAX
SOME. THIS WILL ALLOW AIR MASS TO MODIFY SLIGHTLY FOR A BRIEF TIME
TO ALLOW TEMPS TO REBOUND CLOSER TO 50 ON SATURDAY BUT NEXT SYSTEM
WILL CARVE OUT THE TROUGH IN THE EAST BY LATE SAT AS ARCTIC FRONT
DRAWS NEAR. THE FLOW ALOFT BASICALLY REMAINS W TO NW THROUGH THE
WEEKEND...NOT TAPPING INTO ANY GULF MOISTURE OR WARM AIR AND
ALTHOUGH THE DYNAMICS LOOK DECENT SAT NIGHT...THE AIR MASS REMAINS
DRY AND THEREFORE NOT EXPECTING ANY PCP AND LIMITED...IF ANY CLOUDS
WITH FRONTAL PASSAGE.
THE ARCTIC BLAST BEHIND THE FRONT WILL WORK ITS WAY IN DURING
VALENTINE`S EVENING IN GUSTY W-NW WINDS. 850 TEMPS THAT WERE ABLE TO
WORK THEIR WAY BACK UP TO -3C WILL PLUMMET ONCE AGAIN POSSIBLY LOWER
THAN -20 C AS H5 HEIGHTS DROP OUT TO 530 DEM WHICH...AS MENTIONED
PREVIOUSLY...WILL BE ABOUT -3 STANDARD DEVIATIONS FROM CLIMO.
OVERALL...EXPECT TEMPS TO STRUGGLE TO BREAK FREEZING WITH OVERNIGHT
LOWS DOWN IN THE TEENS MOST PLACES SUN NIGHT AS CAA WANES AND
RATIONAL COOLING EFFECTS TAKE OVER. THE GUSTY NW WINDS SUNDAY AFTN
WILL MAKE IT FEEL LIKE THE 20S MOST PLACES. DEWPOINT TEMPS WILL BE
BELOW 0 DEGREES F ON SUNDAY AFTN WITH THIS BITTER COLD AND DRY
ARCTIC AIR MASS IN PLACE.
DRY AND COLD ADVECTION WILL CONTINUE THROUGH MONDAY AS HIGH PRESSURE
BUILDS DOWN FROM THE NW. WINDS WILL LIGHTEN AND AIR MASS WILL BEGIN
TO MODIFY LATE MONDAY INTO TUES AS HIGH PRESSURE SHIFTS OFF SHORE
AND WARMER AND MOISTER RETURN FLOW SETS UP AHEAD OF NEXT COLD FRONT
SLATED TO CROSS THE AREA BY WED MORNING. PLENTY OF WAA WILL BRING
TEMPS ABOVE FREEZING BY TUES MID MORNING AND THEREFORE WILL LEAVE
OUT MENTION OF ANY MIXED PCP ALTHOUGH IT IS NOT OUT OF THE QUESTION
BRIEFLY VERY EARLY TUES MORNING.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...STRATUS BASED AT 2000-2500 FEET AGL WILL AFFECT THE ILM
AIRPORT THROUGH MID-TO-LATE LATE MORNING ACCORDING TO LATEST
HIGH-RES MODELS AND EXTRAPOLATION OF NIGHTTIME SATELLITE IMAGERY.
THIS IS THE BACK EDGE OF MOISTURE SWIRLING AROUND A POWERFUL LOW
SEVERAL HUNDRED MILES OFF THE CAROLINA COAST. VFR CONDITIONS INLAND
ARE EXPECTED THROUGH THE PERIOD...ALTHOUGH SCATTERED LOW STRATUS
(2000 FT AGL) COULD PUSH INTO THE CRE AND LBT AIRPORTS TEMPORARILY
THROUGH DAYBREAK.
SURFACE WINDS NORTH 10 KNOTS ARE EXPECTED...EXCEPT NEAR ILM UNDER
THE CLOUDS WHERE 10-15G25KT IS EXPECTED. SKIES SHOULD CLEAR EVEN AT
ILM BY LATE MORNING WITH VFR CONDITIONS THIS AFTERNOON THROUGH
TONIGHT.
EXTENDED OUTLOOK...EXPECT VFR THROUGH THE EXTENDED PERIOD.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 AM WEDNESDAY...NO SIGNIFICANT CHANGES ARE NEEDED TO THE
FORECAST AT THIS TIME. PREVIOUS DISCUSSION FROM 1030 PM FOLLOWS...
A GALE WARNING CONTINUES AS LOW PRESSURE STRENGTHENS A LITTLE MORE
AS IT PULLS SLOWLY AWAY FROM COASTAL NORTH CAROLINA OVERNIGHT. THE
PRESSURE GRADIENT WILL FINALLY BEGIN TO RELAX WED MORNING AND THE
GALE WARNING WILL LIKELY BE DOWNGRADED TO A SMALL CRAFT ADVISORY AT
THAT TIME. A NORTH WIND OF 25 TO 35 KT HAS DRIVEN SEAS TO 5 TO 9 FT
WITHIN 20 NM. SEAS AT THE FRYING PAN SHOALS BUOY HAVE BEEN AS HIGH
AS 11 FT THIS EVE. ACROSS LONG BAY...WHERE A NORTH WIND GREATLY
REDUCES THE FETCH...SEAS WERE LESS THAN 3 FT. SEAS WILL NOT BEGIN TO
SIGNIFICANTLY SUBSIDE UNTIL AFTER SUNRISE WED.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...STILL A LITTLE TOUGH TO SAY AT WHAT SPEED
CONDITIONS WILL IMPROVE ON WEDNESDAY AS THE AGITATED WINDS AND SEAS
WILL BE ASSOCIATED WITH A VERY LARGE AND SLOW MOVING OCCLUDED STORM
SYSTEM WELL OFFSHORE. SUCH SYSTEMS MOVEMENT IS NOT ALWAYS HANDLED
SPECTACULARLY BY COMPUTER MODELS. IT WOULD SEEM THAT THERE MAY BE A
LINGERING SMALL CRAFT ADVISORY FOR A TIME FOLLOWING THE LOWERING OF
THE GALE WARNING. WINDS WILL GROW MUCH LIGHTER WEDNESDAY NIGHT AS
THE STORM CONTINUES ITS SLOW EXIT. THE STORM WILL STILL BE VERY
LARGE AND POWERFUL HOWEVER AND WILL STILL BE FLINGING CONSIDERABLE
BACK SWELL ENERGY OUR WAY...SOME OF WHICH WILL BE WAVE SHADOWED BY
CAPE HATTERAS. THIS BACKSWELL ABATES BY THURSDAY OVER THE 0-20 NM
FCST ZONES BUT WILL STILL BE LURKING NOT TOO MUCH FARTHER OFFSHORE.
THEN COMES AN AFTERNOON PASSAGE OF AN ARCTIC FRONT THAT WILL PUSH
CONDITIONS BACK INTO SMALL CRAFT ADVISORY CRITERIA.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 300 PM TUESDAY...GUSTY NW WINDS TO START THE PERIOD WILL
LIGHTEN AND BACK TO THE W THROUGH FRIDAY AS WEAK HIGH PRESSURE
BUILDS IN. SEAS OF 3-6 FT FIRST THING FRIDAY WILL FALL QUICKLY TO
AROUND 2 FT BY FRI NIGHT...BUT W TO SLIGHTLY SW WINDS WILL RISE
ONCE AGAIN ON SATURDAY AHEAD OF THE NEXT COLD FRONT. THIS WILL PUSH
SEAS UP TO 2 TO 4 AND CLOSER TO 3 TO 5 FT LATE SAT AFTN...BUT THE
STRONGEST WINDS WILL OCCUR BEHIND THE COLD FRONT...WHEN NW WINDS
WILL REACH AT LEAST 20-30 KTS. LOOKS LIKE POSSIBLE GALE WARNING MAY
BE NEEDED FOR THESE STRONG WINDS SAT NIGHT INTO SUNDAY. SEAS WILL
RISE RAPIDLY THROUGH SAT NIGHT WITH CURRENT WNA SHOWING WAVE HEIGHTS
UP TO 10 FT IN THE OUTER WATERS SAT NIGHT. THE GREATEST SEAS WILL
GET PUSHED WAY OUT WITH THIS VERY STRONG OFF SHORE FLOW THROUGH
SUNDAY. THE ARCTIC AIR RUSHING OVER THE RELATIVELY WARMER OCEAN
WATERS WILL KEEP A VERY WELL MIXED MARINE LAYER THROUGH SUN NIGHT
BUT GRADIENT WINDS WILL WEAKEN SLOWLY ALLOWING SEAS TO DIMINISH BY
MON MORNING.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...GALE WARNING UNTIL 5 AM EST WEDNESDAY FOR AMZ250-252-
254-256.
&&
$$
NEAR TERM...RJD/TRA
SHORT TERM...MBB
LONG TERM...RGZ
AVIATION...SGL/TRA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
305 AM CST WED FEB 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 305 AM CST WED FEB 11 2015
THE ISSUANCE OF A WIND CHILL ADVISORY IS THE MAIN HIGHLIGHT IN THE
SHORT TERM PERIOD.
A 1050MB SURFACE HIGH PRESSURE CURRENTLY OVER EAST CENTRAL ALBERTA
WILL SLIDE SOUTHEAST TO NEAR REGINA BY 00Z THURSDAY...NEAR HARVEY
AT 06Z THURSDAY...AND INTO CASSELTON BY 12Z THURSDAY. EXPECT A
MOSTLY CLEAR SKY TO DEVELOP AS THE HIGH APPROACHES THIS AFTERNOON
AND TONIGHT. SUB ZERO LOW TEMPERATURES AND WINDS TO 10 MPH WILL
RESULT IN WIND CHILL TEMPERATURES TO 35 BELOW ZERO. A WIND CHILL
ADVISORY HAS BEEN HOISTED TO REFLECT THIS. THE TURTLE MOUNTAINS
WILL BE THE FIRST AREA TO DROP TO AROUND 25 BELOW BY MID AFTERNOON
TODAY AND THUS HAVE DIVIDED THE ADVISORY OUT INTO TWO AREAS. THE
TURTLE MOUNTAINS WILL BE VALID FROM 21Z WEDNESDAY THROUGH 18Z
THURSDAY...AND REMAINING LOCALES ALONG AND EAST OF THE MISSOURI
RIVER WILL HAVE A VALID TIME OF 00Z THURSDAY THROUGH 18Z THURSDAY.
THE LATEST WATER VAPOR IMAGERY SHOWS A NORTHWEST FLOW INTO NORTH
DAKOTA WITH ARCTIC AIR DESCENDING SOUTH FROM ALBERTA/SASKATCHEWAN.
SUCCESSIVE BUT WEAK SHORTWAVES WITH MOSTLY CHANNELED VORTICITY
POSE A SMALL THREAT FOR LIGHT SNOW IN SOUTHWEST NORTH DAKOTA
TODAY. HIGH RESOLUTION HRRR AND RAP13 INDICATE THIS AND HAVE
MAINTAINED THIS FEATURE FROM PREVIOUS FORECASTS. REGIONAL RADAR
ALREADY PICKING UP ON WEAK REFLECTIVITY`S EMERGING OVER NORTH
CENTRAL MONTANA. THE WINDOW OF OPPORTUNITY FOR LIGHT SNOW IS
ROUGHLY FROM 14Z-20Z TODAY. ELSEWHERE THE FOG/STRATUS LOOP SHOWS A
MOSTLY CLEAR SKY ACROSS THE NORTH CENTRAL WHICH IS WORKING TOWARD
THE SOUTH CENTRAL AT THIS TIME. STILL POCKETS OF STRATUS UPSTREAM.
BUFKIT SOUNDINGS THROUGHOUT THE UPCOMING MORNING MAINTAIN A MOIST
BOUNDARY LAYER...AND ONCE MIXING DEVELOPS BY MID MORNING...EXPECT
A PARTLY TO MOSTLY CLOUDY SKY TO ENSUE FOR A FEW HOURS. CONTINUED
MIXING INTO THE AFTERNOON WILL EVENTUALLY LEAD TO LESS CLOUDS AS
SUBSIDENCE AND DRIER AIR ALOFT GETS ENTRAINED AND LEADS TO
CLEARING CONDITIONS. HENCE WHATEVER CLOUDS TO DEVELOP EARLY ON
TODAY WILL DECREASE DURING THE MID TO LATE AFTERNOON. WARM AIR
ADVECTION DEVELOPS WEST OF THE MISSOURI RIVER WEDNESDAY NIGHT
LEADING TO RISING MOTION AND INCREASING CLOUDS IN THE WEST. THUS
TEMPERATURES NOT QUITE AS COLD WITH MINIMUM TEMPERATURES REMAINING
IN THE SINGLE DIGITS ABOVE ZERO WEST. OVERNIGHT LOWS ALONG AND
EAST OF THE MISSOURI RIVER WILL RANGE FROM 10 TO 20 BELOW
ZERO...AND AS MENTIONED ABOVE WIND CHILL TEMPERATURES TO 35 BELOW
ZERO.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 305 AM CST WED FEB 11 2015
THE MEDIUM RANGE MODELS CAUGHT UP WITH THE ECMWF AND ARE NOW
FORECASTING SNOW DEVELOPING AHEAD OF A WARM FRONT OVER WESTERN AND
CENTRAL NORTH DAKOTA THURSDAY. INCREASED SNOW CHANCES MAINLY
THURSDAY AFTERNOON AS A RESULT. NEW SNOW ACCUMULATIONS SHOULD
REMAIN LESS THAN AN INCH.
A DRY COLD FRONTAL PASSAGE IS THEN PROGGED FRIDAY. COLD CANADIAN
AIR IS EXPECTED TO FILTER INTO THE REGION AGAIN FRIDAY NIGHT INTO
SATURDAY. WIND CHILL HEADLINES MAY BE NEEDED EAST OF THE MISSOURI
RIVER FRIDAY NIGHT.
THE MEDIUM RANGE MODELS ARE COMING INTO BETTER AGREEMENT
FORECASTING A SHORTWAVE AND ITS ATTENDANT FRONT DIVING ACROSS
WESTERN AND CENTRAL NORTH DAKOTA LATE SATURDAY AFTERNOON THROUGH
SUNDAY. INCREASED THE CHANCES FOR SNOW GIVEN THE HIGHER CONFIDENCE
WITH THE LATEST MODEL RUNS. SNOW ACCUMULATIONS LOOK TO BE MORE
THAN PREVIOUSLY FORECAST AS WELL. WIDESPREAD AMOUNTS BETWEEN ONE
AND THREE INCHES LOOK POSSIBLE.
SNOW CHANCES WILL LINGER MONDAY AS A COLD FRONT IS PROGGED TO
PUSH FROM NORTH TO SOUTH. HOWEVER...NEW ACCUMULATIONS APPEAR
LIGHT. DRY AND COLD CONDITIONS ARE FORECAST MONDAY NIGHT THROUGH
TUESDAY AS CANADIAN HIGH PRESSURE SETTLES ACROSS MONTANA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 305 AM CST WED FEB 11 2015
LATEST SATELLITE IMAGERY SHOWS MOSTLY CLEAR CONDITIONS WORKING
INTO NORTH CENTRAL NORTH DAKOTA/KMOT...AND SHIFTING SOUTH INTO
KBIS AND KJMS. EXPECT MAINLY VFR CIGS THROUGH MID MORNING WITH
POCKETS OF MVFR CIGS DEVELOPING FROM 15Z-21Z. THE WESTERN
TERMINALS OF KISN AND KDIK WILL LIKELY REMAIN IN THE STRATUS
THROUGH EARLY AFTERNOON. HOWEVER THE OVERALL TREND ACROSS WESTERN
AND CENTRAL NORTH DAKOTA WILL BE FOR DECREASING CLOUDS WEDNESDAY
AFTERNOON AND A RETURN TO VFR CONDITIONS BY 21Z AT ALL TERMINALS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON CST THURSDAY
FOR NDZ001>003-010>013-021>023-025-035>037-046>048-050-051.
WIND CHILL ADVISORY FROM 3 PM THIS AFTERNOON TO NOON CST
THURSDAY FOR NDZ004-005.
&&
$$
SHORT TERM...KS
LONG TERM...TM
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1153 PM CST TUE FEB 10 2015
.UPDATE...
ISSUED AT 1153 PM CST TUE FEB 10 2015
LATEST SATELLITE IMAGERY AND SURFACE OBSERVATIONS SHOW CLOUDY
CONDITIONS WITH POCKETS OF LIGHT SNOW SHOWERS ACROSS CENTRAL AND
SOUTHERN NORTH DAKOTA. A POCKET OF CLEARING IS WORKING THROUGH THE
NORTH CENTRAL AND WILL CONTINUE TO DIVE SOUTHEAST OVERNIGHT. WILL
LET THE WIND ADVISORY EXPIRE IN THE JAMES RIVER VALLEY AS SCHEDULED
AT MIDNIGHT TONIGHT. BRISK NORTHWEST WINDS WILL CONTINUE OVERNIGHT...BUT
SUSTAINED WINDS OF 30 MPH WILL BE ISOLATED AT BEST AS THE MAXIMUM
PRESSURE RISE BUBBLE SHIFTS FARTHER AWAY.
LOOKING AHEAD...WIND CHILL TEMPERATURES TO 25 BELOW ZERO BEGIN TO
EMERGE OVER THE TURTLE MOUNTAINS NEAR SUNRISE WEDNESDAY...AND THIS
EXPAND ACROSS MOST OF NORTH CENTRAL AND INTO THE JAMES RIVER VALLEY
WEDNESDAY NIGHT. WILL BE LOOKING AT POSSIBLE HEADLINES IN THE NEXT
FORECAST ONCE ALL DATA IS ANALYZED AND POPULATED.
UPDATE ISSUED AT 856 PM CST TUE FEB 10 2015
ALTHOUGH SOME ISOLATED GUSTS IN SIOUX AND BURLEIGH COUNTY
REMAIN...THE WINDS ARE GENERALLY DIMINISHING SOUTH CENTRAL SO
WILL ALLOW THE WIND ADVISORY TO EXPIRE THERE. ACROSS THE JAMES RIVER
VALLEY OAKS IS GUSTING TO 48 MPH AT THIS TIME. WILL KEEP THE JAMES
RIVER VALLEY PORTION GONG THROUGH EXPIRATION AT 06Z/MIDNIGHT CST.
UPDATE ISSUED AT 551 PM CST TUE FEB 10 2015
LATEST WINDS AND WIND GUSTS NOW INCREASING ACROSS THE SOUTH
CENTRAL AS THE FORECAST 3HR PRESSURE RISE MOVES ACROSS THIS AREA.
CURRENT WIND ADVISORY IN PLACE FOR A LOW END ADVISORY. SATELLITE
AND RADAR SHOW SOME BANDED SNOW SHOWERS THROUGH CENTRAL NORTH
DAKOTA/ WILL AD 30 TO 50 CHANCE FOR SNOW MINOT TO BISMARCK TO
JAMESTOWN FOR THIS THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 320 PM CST TUE FEB 10 2015
STRONG WINDS AND FALLING TEMPERATURES HIGHLIGHT THE SHORT TERM FORECAST.
AS A OF 20 UTC...A 5MB/3HR PRESSURE RISE BUBBLE WAS ANALYZED OVER
LAKE SAKAKAWEA. THIS FEATURE WILL CONTINUE TO PROPAGATE SOUTHEAST
THROUGH THE LATE AFTERNOON AND EARLY EVENING. WITH 35 TO 40 KTS TO
MIX PER 19 UTC RAP SOUNDINGS...AND ISALLOBARIC FORCING FROM THE
PRESSURE RISES...LOW END WIND ADVISORY CRITERIA GUSTS ARE EXPECTED
INTO THE EARLY EVENING SOUTHWEST AND SOUTH CENTRAL. DID MAINTAIN
A SLIGHT CHANCE FOR SNOW THROUGH THE EVENING AS WELL FOR MUCH OF
WESTERN AND CENTRAL NORTH DAKOTA WITH LIGHT SNOW BEING OBSERVED AT
MULTIPLE SITES ACROSS NORTH DAKOTA INTO SOUTHERN CANADA.
FOR WEDNESDAY...COLD SURFACE HIGH PRESSURE WILL BUILD ACROSS NORTH
DAKOTA. THIS WILL YIELD LITTLE TEMPERATURE RECOVERY FROM MORNING
LOWS WITH CONTINUED COLD AIR ADVECTION THROUGH THE DAY. ADVISORY
LEVEL WIND CHILLS MAY BE POSSIBLE ACROSS THE TURTLE MOUNTAINS BY
LATE AFTERNOON. HOWEVER...WILL FORGO ANY ADVISORY FOR NOW. GIVEN
GOOD AGREEMENT THROUGH THE PERIOD...A BLEND OF THE 12 UTC SUITE
WAS USED FOR MOST FIELDS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 320 PM CST TUE FEB 10 2015
THE LONG TERM WILL BE CHARACTERIZED BY SEVERAL COLD BLASTS AND
OCCASIONAL SNOW CHANCES.
WEDNESDAY NIGHT INTO THURSDAY IS WHEN THE FIRST SUCH COLD BLAST
ENTERS THE REGION. ARCTIC HIGH PRESSURE WILL SETTLE OVER NORTH
DAKOTA THURSDAY MORNING. WITH CLEAR SKIES AND THE MAJORITY OF THE
REGION UNDER AT LEAST A LIGHT BLANKET OF SNOW...TEMPERATURES
SHOULD PLUMMET THURSDAY MORNING INTO THE TEENS AND POSSIBLY 20S
BELOW ZERO EAST OF THE MISSOURI RIVER. SCATTERED LIGHT SNOW MAY
FOLLOW THE HIGH PRESSURE AS AN UPPER LEVEL JET SHOULD BE IN A
FAVORABLE POSITION FOR BROAD SCALE LIFT.
THE NEXT BLAST ARRIVES SATURDAY...WHERE ONCE AGAIN TEMPERATURES
SHOULD ONCE AGAIN FALL INTO THE TEENS BELOW ZERO. AND ONCE AGAIN
SNOW WILL BE POSSIBLE FOLLOWING THE HIGH PRESSURE. HOWEVER...THE
12 UTC GFS AND ECMWF ARE MORE BULLISH WITH THIS EVENT AS A SURFACE
LOW IS FORECAST TO DEVELOP ACROSS EASTERN MONTANA AND SLIDE
SOUTHEAST THROUGH THE DAY SUNDAY. THERE IS THE POTENTIAL FOR MORE
SIGNIFICANT ACCUMULATION WITH THIS EVENT AS THERE APPEARS TO BE
FOCUSED LOW LEVEL ASCENT ALONG WITH THE UPPER LEVEL JET DYNAMICS.
OTHERWISE...THE LONG TERM LOOKS DRY...WITH COLD TEMPERATURES EAST
OF THE MISSOURI AND TEMPERATURES WEST OF THE MISSOURI RIVER
LOOKING RATHER MILD...WITH READINGS IN THE 30S MOST DAYS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1153 PM CST TUE FEB 10 2015
LATEST SATELLITE IMAGERY SHOWS A STRATUS REGIME CONTINUING FOR MOST
OF WESTERN AND CENTRAL NORTH DAKOTA. HOWEVER PARTIAL CLEARING IN THE
NORTH CENTRAL HAS PUSHED INTO KMOT WITH VFR CONDITIONS. MAIN THEME
FOR THIS TAF PERIOD WILL BE A MIX BETWEEN MVFR AND LOW VFR CIGS
THROUGH WEDNESDAY MORNING...THEN A TREND TOWARD A CLEARING SKY
WEDNESDAY AFTERNOON INTO WEDNESDAY EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR NDZ023-025-036-037-
047-048-050-051.
&&
$$
UPDATE...KS
SHORT TERM...AYD
LONG TERM...AJ
AVIATION...KS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
105 AM EST WED FEB 11 2015
.SYNOPSIS...
HIGH PRESSURE BUILDS IN OVERNIGHT. ARCTIC FRONTS CROSSES WEDNESDAY
NIGHT AND AGAIN ON SATURDAY....AND MAYBE EVEN AGAIN NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
100 AM UPDATE...
FCST ON TRACK.
900 PM UPDATE...NO SIGNIFICANT CHANGES MADE. DID ADJUST CLOUDS
TONIGHT BASED ON CURRENT SATELLITE.
PREVIOUS DISCUSSION...
CURRENT SATELLITE IMAGERY SHOWS THE AREA BLANKETED BY LLVL STRATUS
AIDED BY RESIDUAL MOISTURE FROM THE SFC LOW NOW PULLING AWAY FROM
THE MID-ATLANTIC COAST. SOME CLEARING IS BEING OBSERVED IN THE FAR
NW COUNTIES OF OUR CWA AS THE MOISTURE IS SLOWLY ERODED BY DRIER
AIR FROM THE WEST. THE RAP HAS THE BEST HANDLE ON THIS...BUT THATS
NOT SAYING MUCH. MOST GUIDANCE HAS BEEN TERRIBLE WITH RESPECT TO
THE CLEARING OF THE LOW CLOUDS. MOISTURE IS EXPECTED TO HOLD
LONGER IN THE MNTS...WHERE LOW CEILINGS WILL PERSIST UNTIL WED
MORNING.
RELATIVELY QUIET NIGHT ON TAP WITH CLOUD COVER CONTINUING TO ERODE
AS THE UPPER RIDGE SETTLES IN. TEMPERATURES WILL REMAIN ON THE
COOL SIDE TONIGHT AS WE DECOUPLE...BUT WAA BEGINS TO KICK FOR
DAYBREAK AND MIXING WILL BRING WEDS TEMPS BACK UP INTO THE 40S FOR
MOST LOCATIONS.
FOR AS LONG AS IT TOOK THE SW RIDGE TO BUILD IN AND DRY THINGS
OUT...IT UNFORTUNATELY WONT STAY LONG. THE FIRST IN A SERIES OF
UPPER LEVEL WAVES WILL ARRIVE EARLY WEDS AFTERNOON...BRINGING
MAINLY CLOUDS BACK TO THE AREA. AS THE UPPER LEVEL WAVE
ARRIVES...IT DEAMPLIFIES AND THE FLOW ALOFT BECOMES MORE ZONAL.
STILL...SOME WEAK MID-LEVEL CONVERGENCE EXISTS AHEAD OF THE FIRST
WAVE AND MODELS HAVE CONSISTENTLY INCLUDED QPF WITH LIGHT SHOWERS
WEDS EVENING. NOT SOLD ON THE IDEA...BUT WITH THIS FEATURE EVEN
RESOLVED IN THE COARSER SUITE OF MODELS...THOUGHT IS WAS PRUDENT
TO INTRODUCE SLIGHT CHC POPS.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
ACTIVE AND COLD WEATHER PATTERN REMAINS IN THE SHORT TERM AS A
BARRAGE OF UPPER LEVEL WAVES WILL REINFORCE THE MEAN TROF IN THE
EAST. ANOTHER WEAK WAVE WILL PASS JUST NORTH OF THE FORECAST AREA
WEDS NIGHT AND AGAIN WILL DEAMPLIFY AS ON APPROACH. THIS
DEAMPLIFICATION IS DUE TO THE THIRD AND BY FAR MOST VIGOROUS WAVE
DROPPING IN QUICKLY BEHIND IT. EXPECT LIGHT RAIN CHANGING OVER TO
LIGHT SNOW FOR MAINLY NRN PORTIONS OF THE CWA THROUGH THE PRE-DAWN
HOURS THURS.
AROUND DAWN THURS...CONDITIONS WILL DETERIORATE VERY QUICKLY. AS
AN AMPLIFYING TROF DROPS THROUGH THE WRN GREAT LAKES AND TRIES TO
CLOSE OFF AT 500MB. THIS WILL SEND A A VIGOROUS WAVE THROUGH THE
FORECAST AREA...USHERING IN A COLD FRONT WITH A VASTLY DIFFERENT
AIR MASS BEHIND IT. TEMPERATURES WILL FOLLOW A NON-DIURNAL CURVE
WITH THURS HIGHS MORE THAN LIKELY REALIZED NEAR SUNRISE.
ORIENTED ALONG THE COLD FRONT...SNOW SHOWERS WILL OVERTAKE THE
REGION FROM W TO E QUICKLY DURING THE DAYLIGHT HOURS THURS. BEHIND
THE COLD FRONT...850MB TEMPS WILL DROP SHARPLY INTO THE -10 TO
-15C RANGE ALLOWING CRYSTAL GROWTH TO BE MAXIMIZED. WITH LAPSE
RATES STEEPENING...CONVECTIVE SNOW SQUALLS WILL PERSIST THROUGH THURS
EVENING. THE BTV SNOW SQUALL PARAMETER DRIVEN BY THE 12Z NAM DATA
SHOWS A BULLSEYE OF GREATER THAN 4 FOR MUCH OF THE AFTERNOON
THURS...FURTHER DIAGNOSING A PRIME SET UP FOR SNOW SQUALLS TO
EXIST.
MOISTURE IS DRIVEN INTO THE MOUNTAINS THROUGH THURS NIGHT...AND
SNOW SHOWERS SHOULD PERSIST THERE THROUGH MIDNIGHT THURS.
ELSEWHERE...THE MOISTURE QUICKLY DRIES UP...BUT THE AIRMASS IS
COLD ENOUGH THAT LIGHT SNOW SHOWERS OR FLURRIES COULD PERSIST
THROUGH LATE THURS EVENING.
EXPECT MOUNTAINOUS LOCATIONS TO BE IN THE SINGLE DIGITS TO BELOW
ZERO...AS WELL AS SINGLE DIGITS IN SOUTHEAST OHIO FRIDAY MORNING.
ADDING TO THIS IS THE STRONG...GUSTY WINDS THAT WILL DRIVE WIND
CHILLS TO NEAR 0 ACROSS THE LOWLANDS AND WELL BELOW 0 IN THE
MOUNTAINS. STILL EXPECTING WIND CHILL ADVISORY CRITERIA TO BE MET
ACROSS MUCH OF THE MOUNTAINOUS COUNTIES AND PARTS OF NORTHERN WV.
WILL CONTINUE TO HIGHLIGHT IN THE HWO.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MEAN TROF PERSISTS ACROSS THE ERN CONUS THROUGH THE EXTENDED
PERIOD KEEPING A PROLONGED COLD AND DISTURBED WEATHER PATTERN.
BRIEF SFC HIGH FRI WILL BE FOLLOWED QUICKLY BY YET ANOTHER VERY
STRONG CLOSED UPPER LOW THIS WEEKEND. THIS WILL ONCE AGAIN
REINFORCE THE COLD AIR...BRINGING THE COLDEST TEMPERATURES OF THE
WEEK TO OUR AREA. MORE LIGHT SNOW IS EXPECTED THROUGH THE
WEEKEND...BUT THE MAIN STORY LINE WILL BE THE COLD TEMPERATURES.
NEXT WEEK BEGINS WITH A VERY BRIEF SPELL OF ZONAL FLOW ALOFT AND
TEMPERATURE MODERATION BEFORE YET ANOTHER INTRUSION OF ARCTIC AIR.
MAINLY FOLLOW WPC FOR WEATHER VARIABLES IN THE EXTENDED...WITH
CONSIDERABLE MODEL AGREEMENT BETWEEN THE GFS/ECMWF.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
MOIST LOW LEVEL NRLY FLOW CONTINUES ON BACK SIDE OF LOW PRESSURE
MOVING OFF THE E COAST. THIS HAS THE MOUNTAINS SOCKED IN IN IFR
BOTH EKN AND BKW ON OR SOON TO BE ON BOTH CIGS AND VSBYS. HIGH
PRESSURE BUILDING IN TOWARD DAWN WILL CAUSE THE FLOW TO
DIMINISH...WHICH OF COURSE DOES NOTHING TO SCOUR OUT THE LOW LEVEL
MOISTURE. AS SUCH...IT WILL TAKE POST DAY BREAK MIXING TO IMPROVE
CONDITIONS THERE.
OUT ACROSS THE LOWLANDS WHERE CLEARING DID MANAGE TO TAKE
PLACE...MVFR VALLEY MIST IS LIKELY...WITH IFR VALLEY FOG NEAR DAWN
MOST LIKELY AT CRW AND CKB. THIS WILL BURN OFF AFTER SUNRISE...AND
IT MAY HAVE DRIED OUT JUST ENOUGH TO NOT HAVE MORNING CU.
HIGH PRESSURE MOVES E OF THE AREA WED...AND HIGH AND THEN MID CLOUD
INCREASE AS AN ARCTIC FRONT APPROACHES FROM THE NW. THIS WILL START
BRINGING LOWER CLOUDS AND SNOW SHOWERS INTO THE MIDDLE OHIO VALLEY
06Z THU.
LIGHT N SFC FLOW BECOMES CALM BY DAWN AND THEN LIGHT AND VARIABLE
WED...AND THEN LIGHT W TO SW AHEAD OF THE ARCTIC FRONT LATE WED AND
WED EVENING. LIGHT AND VARIABLE FLOW ALOFT WILL BECOME LIGHT W WED
AND THEN INCREASE TO MODERATE W WED NT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIO: IFR CONDITIONS IN THE MOUNTAINS MAY VARY...AS
MAY FORMATION AND TIMING OF IFR FOG IN LOWLAND VALLEYS.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE WED 02/11/15
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY M M M M M M M H H H H H
HTS CONSISTENCY M M M M H H H H H H H H
BKW CONSISTENCY L M L L L L L L H H H H
EKN CONSISTENCY L L L L L L L H H H H H
PKB CONSISTENCY M M M M H H H H H H H H
CKB CONSISTENCY M M M M M M M H H H H H
AFTER 06Z THURSDAY...
IFR IN THE MOUNTAINOUS COUNTIES IN SNOW SHOWERS ON THURSDAY...AND AT
TIMES SATURDAY NIGHT...EACH IN THE WAKE OF ARCTIC FRONTS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...MZ
NEAR TERM...TRM/MZ
SHORT TERM...SL
LONG TERM...ARJ
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
344 AM CST WED FEB 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CST WED FEB 11 2015
A COLDER AND BREEZY DAY IS ON TAP FOR THE AREA TODAY. NORTHWESTERLY
WINDS WILL AVERAGE 15 TO 30 MPH...WITH A FEW GUSTS APPROACHING 40
MPH...MAINLY IN SOUTHWEST MINNESOTA. CLOUD COVER A BIT TRICKY...BUT
OVERALL THINKING IT STAYS MOSTLY CLOUDY. WE DO SEE ENOUGH DRYING
THOUGH THAT THINK SOME PEAKS OF SUN ARE LIKELY. WIND CHILLS THIS
MORNING WILL RANGE FROM 0 TO -10. HIGHS THIS AFTERNOON WILL REACH
THE UPPER TEENS SOUTHWEST MINNESOTA TO THE UPPER 20S TO AROUND 30
ALONG THE MISSOURI RIVER.
WILL SEE A SECONDARY SURGE OF COLD AIR DIVE SOUTH INTO THE REGION
TONIGHT. THIS WILL HELP ENHANCE WINDS A BIT THIS EVENING AND WILL
LIKELY APPROACH SUSTAINED ADVISORY CRITERIA OF 30 MPH...ESPECIALLY
IN SOUTHWEST MINNESOTA. HOWEVER WILL BE PRETTY MARGINAL...AND
THINKING THE HIGHEST GUSTS WILL GENERALLY STAY BELOW 45 MPH. SO WILL
HOLD OFF ON ANY ADVISORY. TEMPERATURES WILL PLUMMET AGAIN
TONIGHT...ALTHOUGH THE STRONG WINDS AND CLOUDS WILL PREVENT A
RADIATIONAL DROP. AS THE SURFACE HIGH DROPS SOUTH...SKIES WILL
CLEAR AND WINDS WILL WEAKEN BY MORNING...BUT WITHOUT SNOW
COVER...STILL NOT THINKING TEMPERATURES REALLY TANK. THUS GOING WITH
LOWS FROM 0 TO -5 IN THE NORTHEAST HALF OF THE AREA AND 0 TO +5
SOUTHWEST. WIND CHILLS WILL DROP INTO THE -10 TO -20 RANGE BY
MIDNIGHT AND STAY THERE INTO THE MORNING. WILL BE AROUND WIND CHILL
ADVISORY CRITERIA NORTHEAST OF A DESMET TO SIOUX FALLS TO SPENCER
LINE...WITH VALUES BETWEEN -20 AND -25 POSSIBLE. GIVEN MARGINAL
VALUES WILL NOT ISSUE ANYTHING AND LET DAY SHIFT REASSESS...EITHER
WAY IT WILL BE A COLD MORNING.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 343 AM CST WED FEB 11 2015
THE FORECAST IN THE INTERMEDIATE AND LONGER TERM IS HIGHLIGHTED BY A
SHARP NORTHWEST FLOW ALOFT WITH A BROAD LONG WAVE TROUGH DOMINATING
EASTERN NORTH AMERICA. THIS PATTERN WILL CONTINUALLY GIVE OUR AREA
SHORT WAVES MOVING DOWN FROM CANADA. THE PATTERN WILL BE WINDY...
WITH PLENTY OF COLD AIR ADVECTION SURGES INTERRUPTED BY BRIEF WARM
AIR ADVECTION PERIODS.
ONCE SUCH BRIEF WARM ADVECTION SURGE OCCURS ON THURSDAY WHEN SURFACE
HIGH PRESSURE MOVES OFF TO THE EAST. MANY OF THE DETERMINISTIC
GLOBAL MODELS AS WELL AS HIRES SOLUTIONS CONTINUE TO SHOW A STRIPE
OF SNOW DEVELOPING ON THE LEADING EDGE OF THE WARM FRONT.
INCLUDED CHANCE POPS LATE THURSDAY AFTERNOON AND EVENING MAINLY EAST
OF THE JAMES RIVER VALLEY WHERE MOISTURE PROFILES ARE FAIRLY
SATURATED THROUGH A DEEP LAYER. THE ONLY THING LACKING IS STRONG
MOISTURE BELOW ABOUT 800MB...OR THIS COULD BE A DECENT LIGHT SNOW
EVENT. AS IT SITS NOW...SNOW AMOUNTS LOOK TO BE GENERALLY AROUND A
HALF INCH OR LESS. BUT WOULD NOT BE SURPRISED AS WE GET CLOSER TO
THE EVENT IF IT TURNS INTO A HIGH POP/LOW QPF EVENT FOR MANY
AREAS...AT LEAST EAST OF I 29 IF THIS MODEL TREND CONTINUES.
WITH THE AFOREMENTIONED WARM AIR ADVECTION...TEMPERATURES WILL NOT
COOL OFF MUCH THURSDAY NIGHT IF ANY AT ALL...LEADING INTO A
SEASONABLY MILD DAY ON FRIDAY AHEAD OF THE NEXT ARCTIC COLD FRONT.
ON FRIDAY HIGHS SHOULD RANGE FROM THE 30S EAST...TO WIDESPREAD 40S
IN OUR WESTERN ZONES.
THEN THE BOTTOM FALLS OUT. BIG COLD FRONT MOVES SOUTHWARD FRIDAY
NIGHT. ONCE AGAIN SIMILAR TO THE NEAR TERM...WOULD NOT BE SURPRISED
IF WIND SPEEDS PUSHED WIND ADVISORY CRITERIA IN A 3 TO 6 HOUR PERIOD
WITH THE STRONG COLD AIR ADVECTION PUSH. IN ADDITION...THE GFS SHOWS
A BIT OF LIGHT SNOW POTENTIAL EAST OF THE JAMES RIVER FRIDAY NIGHT.
HOWEVER THIS WAS NOT BACKED UP YET BY THE ECMWF OR GEM GLOBAL. THE
ECMWF WAS THE FIRST MODEL TO PICK UP ON THE PROBABLE LIGHT SNOW
EVENT FOR LATE THURSDAY AFTERNOON AND EVENING...LEADING THE OTHER
TWO MODELS. THEREFORE WOULD NOT RULE OUT FLURRIES FRIDAY NIGHT BUT
KEPT IT DRY FOR NOW DUE TO THE ECMWF AND GEM GLOBAL SOLUTIONS.
SATURDAY WILL HARBOR A MINIMAL RISE IN TEMPERATURES OF ONLY ABOUT 5
DEGREES OFF OF MID MORNING LOWS. LIKELY STAYING IN THE SINGLE DIGITS
ABOVE ZERO IN SOUTHWEST MN...TO MAYBE NEAR 20 IN GREGORY COUNTY.
THEN SIMILAR TO THURSDAY...ANOTHER BRIEF SURGE OF WARM AIR ADVECTION
SETS UP SATURDAY NIGHT EXCEPT THIS AIR MASS IS COLDER OVERALL.
SLIGHT CHANCE TO CHANCE POPS ARE WARRANTED FOR MOST OF THE FORECAST
AREA SATURDAY NIGHT AND/OR SUNDAY...WITH WHAT SHOULD BE AN INCH OR
LESS OF SNOW POTENTIAL. AGAIN...IF THIS MODEL TREND HOLDS...POPS
WILL BE GOING UP WITH FUTURE RUNS AS WE GET CLOSER TO THE EVENT.
MONDAY CONTINUES TO BE AN INTERESTING DAY. THE ECMWF CONTINUES TO BE
BULLISH WITH A DECENT SNOW EVENT AS A STRONG SHORT WAVE INTERACTS
WITH STRONG LOW TO MID LEVEL CONVERGENCE. AT THE SURFACE...IT
CONTINUES TO SHOW ANOTHER ARCTIC HIGH OOZING DOWN...COUPLED WITH LOW
PRESSURE IN THE CENTRAL AND SOUTHERN PLAINS PROVIDING A GOOD SQUEEZE
OF AIR IN OUR AREA WITH PLENTY OF ISENTROPIC LIFT. THE GEM AND GFS
CONTINUE TO BE MUCH LESS BULLISH SO ONLY CHANCE POPS ARE WARRANTED.
BUT SOMETHING TO WATCH FOR AS THE DAYS PROGRESS. ONE THING THE
MODELS DO AGREE ON...IS MORE ARCTIC AIR POURING IN FOR NEXT TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1039 PM CST TUE FEB 10 2015
EXPECT MVFR CIGS TO LINGER THROUGH THE NIGHT IN THE COLD AIR
ADVECTION REGIME BEHIND THE FRONT. TIMING OF THE STRATUS LIFTING
OR CLEARING OUT IS UNCERTAIN...WITH THE NAM AND GFS HOLDING ONTO
IT INTO WEDNESDAY WHILE THE HRRR LIFTS IT INTO VFR FROM WEST TO
EAST EARLY IN THE TAF PERIOD. WILL GO WITH A MORE PESSIMISTIC
SOLUTION WITH THE COLD AIR ADVECTION REGIME. SCATTERED FLURRIES
WILL ALSO BE POSSIBLE OVERNIGHT. WINDS WILL BE BLUSTERY FROM THE
NORTHWEST WITH GUSTS AS HIGH AS 35 KT INTO THE EARLY MORNING
HOURS. WHILE WINDS DO DECREASE AROUND DAYBREAK...THEY WILL REMAIN
BREEZY THROUGH THE DAY WEDNESDAY WITH GUSTS AROUND 20 TO 30 KT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...MJ
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1049 PM CST TUE FEB 10 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 255 PM CST TUE FEB 10 2015
PRECIPITATION OUT AHEAD OF A SURFACE TROUGH IS FINALLY COMING TO AN
END OVER SOUTHWESTERN MINNESOTA THIS AFTERNOON. OTHERWISE...COLDER
AIR WILL BEGIN FEEDING INTO THE REGION OVERNIGHT...AND WITH ENHANCED
MIXING AND A TIGHTENING GRADIENT NORTHWESTERLY WINDS WILL PICK UP
THROUGH THE EVENING AND CONTINUE THROUGH MOST OF THE DAY ON
WEDNESDAY. A SHORTWAVE PRESENTLY OVER NORTH DAKOTA WILL DROP
SOUTHWARD TONIGHT...AND MAY PROVIDE ENOUGH LIFT TO TRIGGER A FEW
FLURRIES THROUGH OUR NORTH AND EAST IN A SATURATED DENDRITIC LAYER.
WITH THE COLD AIR ADVECTION...IT WILL BE A MUCH COLDER NIGHT WITH
LOWS IN THE TEENS TO AROUND 20. A SURFACE RIDGE WILL BUILD SOUTHWARD
ACROSS THE REGION ON WEDNESDAY...AND AS MENTIONED PREVIOUSLY IT WILL
BE WINDY. HIGHS WILL RUN FROM THE TEENS OVER EAST CENTRAL SD AND
SOUTHWESTERN MN...TO THE UPPER 20S THROUGH THE MO RIVER CORRIDOR.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 255 PM CST TUE FEB 10 2015
COLD HIGH PRESSURE BUILDS INTO THE AREA ON WEDNESDAY NIGHT SO WENT
AHEAD AND LOWERED LOWS JUST A TOUCH. WITHOUT A LOT OF SNOW COVER NOT
GOING TO BE NEARLY AS COLD AS IT COULD BE. SINGLE DIGITS BELOW ZERO
ALONG AND NORTH OF INTERSTATE 90 AND SINGLE DIGITS ABOVE ZERO SOUTH.
THURSDAY WILL SEE HIGH PRESSURE SHIFT SOUTHEAST QUICKLY WITH RETURN
FLOW AND WARMER AIR TRYING TO BUILD IN...MAINLY IN THE EVENING AND
NIGHT TIME. SO THE HIGH TEMPERATURES WILL STILL BE PRETTY
COLD...TEENS IN THE EAST AND LOWER 30S IN SOUTH CENTRAL SOUTH
DAKOTA.
WITH A FAVORABLE THERMAL PROFILE AND WEAK WAVE SLIDING SOUTH WILL
ADD SOME SMALL POPS FOR LIGHT SNOW IN THE EASTERN THIRD OF THE CWA.
RELATIVELY MILD THURSDAY NIGHT INTO FRIDAY WITH LOWS IN THE TEENS
AND HIGHS FROM AROUND 30 IN SOUTHWEST MINNESOTA TO THE MID 40S IN
SOUTH CENTRAL SOUTH DAKOTA.
IN THE OUTER PERIODS (SATURDAY THROUGH TUESDAY)...WEST TO NORTHWEST
FLOW ALOFT WILL OCCASIONALLY AMPLIFY TO A MORE NORTHERLY DIRECTION
ALLOWING COLDER AIR TO FILTER IN. SATURDAY WILL BE ONE OF THESE
TIMES WHEN SOME PRETTY DARN COLD AIR WILL DRIVE INTO THE REGION.
WITH A DECENT GRADIENT IN THE MORNING THE ACTUAL TEMPERATURE WILL
NOT BE TOO EXCESSIVELY COLD...MAINLY SINGLE DIGITS...BUT THE WIND
CHILL VALUES WILL LIKELY FALL TO 15 BELOW TO 25 BELOW ZERO. NOT OUT
OF THE QUESTION SATURDAY NIGHT INTO SUNDAY TO GET A LITTLE LIGHT
SNOW AS RETURN FLOW ALOFT DEVELOPS BUT FOR NOW WILL KEEP POPS FAIRLY
LOW. THE MODELS BECOME A LITTLE LESS AGREEABLE MONDAY INTO TUESDAY
BUT STILL THE OVERALL MESSAGE WILL BE BELOW NORMAL TEMPERATURES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1039 PM CST TUE FEB 10 2015
EXPECT MVFR CIGS TO LINGER THROUGH THE NIGHT IN THE COLD AIR
ADVECTION REGIME BEHIND THE FRONT. TIMING OF THE STRATUS LIFTING
OR CLEARING OUT IS UNCERTAIN...WITH THE NAM AND GFS HOLDING ONTO
IT INTO WEDNESDAY WHILE THE HRRR LIFTS IT INTO VFR FROM WEST TO
EAST EARLY IN THE TAF PERIOD. WILL GO WITH A MORE
PESSIMISTICSOLUTIONWITH THE COLD AIR ADVECTION REGIME. SCATTERED
FLURRIES WILL ALSO BE POSSIBLE OVERNIGHT. WINDS WILL BE BLUSTERY
FROM THE NORTHWEST WITH GUSTS AS HIGH AS 35 KT INTO THE EARLY
MORNING HOURS. WHILE WINDS DO DECREASE AROUND DAYBREAK...THEY WILL
REMAIN BREEZY THROUGH THE DAY WEDNESDAY WITH GUSTS AROUND 20 TO 30
KT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...08
AVIATION...
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
404 AM CST WED FEB 11 2015
.SHORT TERM...
NORTHERLY WIND SHIFT HAS PUSHED THROUGH ALREADY BUT STRONGER
PRESSURE GRADIENT STILL AWAITS WITH MAIN COLD AIR ADVECTION LATER
THIS MORNING INTO THE EARLY AFTERNOON. MOST RECENT RAP AND HRRR RUNS
SEEM TO SUPPORT WIND SPEEDS NEAR OR JUST SHY OF WIND ADVISORY
LEVELS. A WEAK UPPER LOW MEANWHILE EXPECTED TO PINCH OFF ACROSS THE
SOUTHERN ROCKIES LATER TODAY WHILE DROPPING SOUTHWARD. BEST LIFT AND
MOISTURE APPEAR TO REMAIN JUST TO OUR WEST...BUT PERHAPS ENOUGH LIFT
WITH MEAGER MOISTURE LAYERS TO SUPPORT LOW CHANCES OF LIGHT RAIN OR
SHOWERS MAINLY WESTERN AND CENTRAL ZONES AT LEAST THIS AFTERNOON AND
EARLY EVENING. LATEST SOLUTIONS HAVE TRIMMED BETTER PRECIPITATION A
BIT FURTHER WEST OF PREVIOUS FORECAST AND WE HAVE FOLLOWED THIS
TREND AS WELL. DRYING AND SUBSIDENT AIRMASS SHOULD GRADUALLY TAKE
BACK OVER OVERNIGHT. RECENT TEMPERATURE GUIDANCE REASONABLY SIMILAR
TO PREVIOUS WITH ONLY MINOR CHANGES. RMCQUEEN
.LONG TERM...
DRY NORTHWEST FLOW WILL SET UP THURSDAY INTO THE WEEKEND BETWEEN
WEST COAST RIDGING EXTENDING INTO THE YUKON/NORTHWEST TERRITORIES
AND LOCKED IN CYCLONIC FLOW ACROSS EASTERN NORTH AMERICA. SURFACE
RIDGING WILL SLIDE EAST INTO THE MIDWEST THURSDAY AS LEE TROUGHING
TAKES FORM IN THE FRONT RANGE BEFORE EJECTING INTO THE PLAINS FRIDAY
BRINGING A NORTHERLY WIND SHIFT TO THE SOUTH PLAINS. ANY SEMBLANCE
OF COOLER AIR WILL REMAIN BOTTLED UP SEVERAL HUNDRED MILES TO THE
NORTHEAST...ALLOWING THE WARMING TREND TO CONTINUE INTO THE WEEKEND.
AFTER TEMPERATURES TOPPING OUT NEAR NORMAL IN THE 50S THURSDAY...A
STEADY RISE INTO THE 60S AND 70S WILL BE ON DECK FOR FRIDAY AND
SATURDAY RESPECTIVELY. A BACKDOOR FRONT WILL PUSH THROUGH THE PLAINS
SATURDAY AS YET ANOTHER LOBE OF ENERGY ROTATES AROUND A LOW ANCHORED
IN VICINITY OF HUDSON BAY...ARRIVING SOMETIME EARLY SUNDAY AND
LIKELY RESULTING IN A DECENT NORTHEAST TO SOUTHWEST TEMPERATURE
GRADIENT WITH HIGHS RANGING FROM THE UPPER 50S IN THE FAR SOUTHEAST
PANHANDLE TO NEAR 70 IN THE SOUTHWEST SOUTH PLAINS.
A SIGNIFICANT PATTERN CHANGE CONTINUES TO LOOM FOR EARLY NEXT WEEK
WITH BACKING UPPER FLOW DOWNSTREAM OF AN UPPER LOW...ORIGINATING
FROM A LOW OFF BAJA PHASING WITH THE RETROGRADE CUTOFF LOW
RESPONSIBLE FOR TODAY/S FRONT...AND SHORTWAVE TROUGH MIGRATING
SOUTHEASTWARD OUT OF WESTERN CANADA. MOISTURE ADVECTION LOOKS TO
HAVE LONG ENOUGH OF A RESIDENCE TIME FOR PRECIPITATION TO BECOME A
POSSIBILITY BY LATE MONDAY INTO TUESDAY AT THIS JUNCTURE. THIS LOOKS
TO BE WHEN NWP SOLUTIONS BEST CONVERGE ON UPPER SUPPORT COMBINING
WITH FRONTOGENETICAL FORCING FROM WHAT AT THIS POINT LOOKS TO BE A
STOUT FRONT...SERVING AS A REMINDER THAT FEBRUARY IS INDEED WINTER
IN THE NORTHERN HEMISPHERE. OVERALL TRENDS HAVE BEEN SHOWING THIS
PATTERN DEVELOPING WITH EASTERN PACIFIC RIDGING BECOMING HIGHLY
AMPLIFIED ENOUGH TO ALLOW FOR A SIGNIFICANT DUMP OF COLD AIR THROUGH
THE CENTRAL CONUS. AS FAR AS PRECIPITATION TYPE...A MIX OF RAIN AND
SNOW INITIALLY TRANSITIONING TO ALL SNOW SEEMS VALID GIVEN THIS
EXPECTED PUNCH OF CANADIAN AIR LASTING INTO MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 43 26 55 30 / 40 10 0 0
TULIA 47 28 54 30 / 20 10 0 0
PLAINVIEW 49 28 54 30 / 20 10 0 0
LEVELLAND 50 30 54 31 / 20 20 0 0
LUBBOCK 51 30 54 31 / 20 10 0 0
DENVER CITY 50 31 54 30 / 20 30 0 0
BROWNFIELD 50 31 54 31 / 20 30 0 0
CHILDRESS 56 30 53 32 / 10 10 0 0
SPUR 53 31 53 31 / 10 10 0 0
ASPERMONT 57 33 52 33 / 10 10 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/31
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1018 AM EST WED FEB 11 2015
.SYNOPSIS...
GENERALLY COLD AND DRY CONDITIONS EXPECTED TODAY. LIGHT OCEAN
EFFECT SNOW WILL AFFECT PORTIONS OF SOUTHEAST COASTAL
MASSACHUSETTS TODAY INTO TONIGHT. NUISANCE LIGHT SNOW MAINLY FOR
SOUTHEAST NEW ENGLAND ESPECIALLY CAPE COD AND THE ISLANDS THURSDAY
INTO FRIDAY. A MORE POTENT WINTER STORM IS POSSIBLE FOR SATURDAY
INTO SUNDAY. BELOW AVERAGE TEMPERATURES FOR MUCH OF THE FORECAST
PERIOD...WITH AN ARCTIC CHILL EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...
OCEAN EFFECT SNOW FAIRLY EXPANSIVE ACROSS MUCH OF E MA AND INTO
RI THIS MORNING. HRRR NOT PICKING UP ON THIS AT ALL BUT HIRESWRF
IS HINTING AT IT ALTHOUGH NOT TO THE EXTENT OF WHAT/S HAPPENING.
SNOW PRODUCTION ALL OCCURRING BELOW 9O0 MB AS STRONG SUBSIDENCE
INVERSION ABOVE THIS. SOUNDINGS ARE SATURATED BELOW 900 MB WITH
FAIRLY STEEP LAPSE RATES. COLDEST TEMPS IN THE MIXED LAYER AROUND
-11 TO -12C SO DELTA T FROM SST IS RUNNING ABOUT 14-15C AND
SATURATION THROUGH -12C ALLOWING FOR ICE NUCLEATION AND FAVORABLE
SNOW PRODUCTION. WITH NE TRAJECTORY SNOW IS EXTENDING WEST ACROSS
MUCH OF E MA AND EVEN INTO RI. ALSO NOTING SOME DECENT LOW LEVEL
CONVERGENCE E COASTAL MA WITH N/NW WINDS AT BOS/OWD AND NE WINDS
AT BOS BUOY AND GHG WHICH IS HELPING TO ENHANCE THE SNOW IN THIS
AREA.
NOT MUCH CHANGE NOTED IN THE SOUNDINGS THROUGH THE DAY SO EXPECT
SNOW...MOSTLY LIGHT TO CONTINUE FOR MUCH OF THE DAY IN E MA WITH
PERIODIC LIGHTER SNOW IN RI. HIRESWRF MORE BULLISH ON SNOWFALL
THIS AFTERNOON ACROSS SE MA COASTAL MA. ACCUM OF AN INCH OR 2 IS
LIKELY...ESPECIALLY IN E MA FROM BOS SOUTH THROUGH OWD AND INTO
PLYMOUTH COUNTY.
FURTHER WEST...EXPECT PT-MOSUNNY SKIES ACROSS CENTRAL AND W MA
INTO THE CT VALLEY FURTHER REMOVED FROM MARINE INFLUENCE AND OCEAN
MOISTURE.
GUSTY N/NE WINDS TO 30-40 MPH WILL CONTINUE INTO THE EARLY
AFTERNOON ACROSS SE COASTAL MA AND ESPECIALLY THE
CAPE/ISLANDS...STRONGEST AT ACK. WINDS WILL BEGIN TO DIMINISH AFT
18Z. NO CHANGES TO TEMPS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
FOR TONIGHT...SNOW BANDS SHOULD BEGIN TO DISSIPATE BY AROUND
MIDNIGHT AS THE LOW DEPARTS AND PRES GRADIENT WEAKENS. NEXT SYSTEM
ALREADY STARTS TO APPROACH OUT OF NY STATE. WILL SEE MID AND HIGH
CLOUDS INCREASE FROM THE W ACROSS WESTERN AREAS TONIGHT. MAY SEE
SOME SCT LIGHT SNOW MOVE INTO THE E SLOPES OF THE BERKSHIRES AFTER
08Z. WINDS WILL BECOME LIGHT AND VARIABLE AS TEMPS FALL BACK...
GENERALLY IN THE SINGLE DIGITS AWAY FROM THE COAST EXCEPT POSSIBLY
BELOW ZERO IN A FEW SPOTS ACROSS THE HIGHER INLAND TERRAIN...
RANGING TO THE TEENS TO LOWER 20S ALONG THE IMMEDIATE COAST.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
*/ HIGHLIGHTS...
- NUISANCE LIGHT SNOW THURSDAY INTO FRIDAY
- MORE POTENT WINTER STORM POSSIBLE SATURDAY INTO SUNDAY
- ARCTIC CHILL EARLY NEXT WEEK
*/ OVERVIEW...
DETERMINISTIC AND ENSEMBLE-MEMBER SOLUTIONS CLUSTERING QUITE WELL
FOR THE THURSDAY-FRIDAY PERIOD WITH THE NUISANCE LIGHT SNOW MAINLY
ACROSS SE NEW ENGLAND FOLLOWING BY AN ARCTIC INTRUSION OF COLDER
AIR. THEREAFTER ENSEMBLE SOLUTIONS ARE PREFERRED WHICH ADVERTISE A
+PNA/+NAO TREND. LOOKING AT AN ACTIVE WEATHER PATTERN LONG TERM WITH
PREFERRED TROUGHING ACROSS THE E-CONUS ALONG WITH CONTINUED WAVES OF
ARCTIC AIR. WINTER NOT COMING TO AN END ANY TIME SOON. TEMPERATURES
EXPECTED TO REMAIN BELOW-NORMAL FOR QUITE SOMETIME. NO CONFIDENCE TO
ASSUME THIS PATTERN WILL BREAK ANY TIME SOON.
*/ DAILIES...
THURSDAY INTO FRIDAY MORNING...
FORECAST GUIDANCE CONSENSUS SIGNALS A PROGRESSIVE FLOW PATTERN THRU
WHICH PACIFIC-ENERGY DIVES SE THRU BROADER CYCLONIC FLOW AMPLIFYING
AN H5 OPEN-WAVE TROUGH AND ACCOMPANYING JET-STREAK ACROSS THE NE-
CONUS. SURFACE LOW PRESSURE IS INVOKED ACROSS REGIONS OF BETTER BARO-
CLINICITY WELL-OFFSHORE OF NEW ENGLAND SE OF THE 40N/70W BENCHMARK
TUESDAY QUICKLY DEEPENING EASTWARD TOWARDS SE CANADA TUESDAY NIGHT.
AM SKEPTICAL AS TO WHETHER WE WILL EVEN SEEN ADVISORY-LEVEL CRITERIA
WITH THIS STORM. VENTURE TO GUESS THAT REACHING CRITERIA WOULD BE
A CONSEQUENCE OF THE FLUFF-FACTOR OF THE SNOW WITH HIGH SNOW-TO-
LIQUID RATIOS.INTENSIFICATION/OCCLUSION OF THE STORM DOES NOT OCCUR
UNTIL WELL DOWNSTREAM BY WHICH POINT THE H7 LOW CLOSES OFF AS WARM-
MOIST HIGHER-PWAT AIR IS DRAWN INTO THE CENTER. MUCH OF THE FOCUS
ACROSS OUR REGION IS DURING THE OVERRUNNING PHASE ALBEIT BRIEF AS
LOW- TO MID-LEVEL MOISTURE ISENTROPICALLY ASCENDS ALONG 285-295K
SURFACES ENCOUNTERING FRONTOGENESIS ALONG THE SW-NE THERMAL GRADIENT
AND MID-LEVEL ASCENT PER MAIN IMPULSE THROUGH THE H5 OPEN-WAVE TROUGH.
NO LONGER DOES IT APPEAR THAT TROWALING AND BACK-BANDING OF MOISTURE
WILL PREVAIL AS THE STORM WILL BE WELL DOWNSTREAM.
LOOKING AT LIGHT SNOW TO RAMP-UP THROUGH THE DAY THURSDAY...WITH
THE MAJORITY OF IMPACTS CENTERED AROUND THE THURSDAY AFTERNOON/
EVENING COMMUTE WHEN ISENTROPIC ASCENT/DEEP-LAYER LIFT ARE AT
THEIR GREATEST POTENTIAL YIELDING DECENT OMEGA THRU BEST SNOW-
GROWTH REGIONS. AM EXPECTING ACTIVITY TO TAPER OFF BEGINNING
MIDNIGHT INTO FRIDAY MORN. NOT A PRONOUNCED SYSTEM...BUT THE
LONGEVITY OF WHICH LOOK TO YIELD QPF AMOUNTS AROUND 0.2 INCHES...
AND CONSIDERING A 12:1 TO 15:1 SNOW TO LIQUID RATIO WOULD RESULT
IN SNOWFALL AMOUNTS RANGING ON AVERAGE 2 TO 4 INCHES. SO THIS
EVENT IS APPEARING TO BE A LOW-END ADVISORY STORM /WHEW/ FOR
MAINLY THE CAPE AND ISLANDS BASED ON CONFIDENCE. BUT AM GOING TO
HOLD OFF ON THE ISSUANCE OF ANY HEADLINES. WHY? WELL FOR ONE
FORECAST GUIDANCE HAVE TRENDED SLIGHT FASTER AND E WITH THIS
SYSTEM...AND TWO...THIS HAS SUBSEQUENTLY DOWNGRADED QPF AMOUNTS.
AM GOING TO LET THE DAY- SHIFT TAKE ONE MORE LOOK AT IT BUT AGAIN
BASED ON CONFIDENCE...WOULD SUGGEST WINTER WEATHER ADVISORIES FOR
THE CAPE AND ISLANDS.
AS THE STORM LIFTS OUT TO SEA INTENSIFYING...ISALLOBARIC COMPONENT
OF THE WIND AMPLIFIES THE NW-FLOW. COUPLED WITH STRONG COLD-AIR
ADVECTION REARWARD...AND WIND CHILLS ARE EXPECTED TO FALL TO OR
BELOW -15 DEGREES ACROSS THE HIGH TERRAIN OF THE BERKSHIRES AND
WORCESTER HILLS.
FRIDAY INTO SATURDAY MORNING...
FRIDAY WILL BE WINDY OUT OF THE NW AS THE STORM AMPLIFIES TO THE
E AND HIGH PRESSURE BUILDS IN FROM THE W. A COLD DAY FOR SURE
AIDED BY BLUSTERY FLOW MAKING IT FEEL COLDER. MID- TO UPPER-20S
HIGHS WILL ACTUALLY FEEL MORE IN THE TEENS. MUCH COLDER INTO
SATURDAY MORNING AS HIGH PRESSURE ALLOWS WINDS TO RELAX OVER THE
DEEP SNOWPACK. A SAVING CAVEAT PREVENTING GOOD RADIATIONAL COOLING
IS INCREASING CLOUDS AHEAD OF THE NEXT STORM SYSTEM THROUGH THE
REMAINDER OF THE WEEKEND. LOWS FALLING INTO THE SINGLE DIGITS WITH
A FEW SPOTS LIKELY TO FALL BELOW-ZERO...ESPECIALLY E/NE INTERIOR
MASSACHUSETTS.
WIND CHILL ADVISORIES MAY NEED TO CONTINUE THROUGH THE DAY FOR THE
HIGH TERRAIN OF N/W MA...DEFINITELY FRIDAY NIGHT INTO SATURDAY MORN.
SATURDAY INTO SUNDAY...
CONTINUED ENSEMBLE/DETERMINISTIC AGREEMENT OF AN ARCTIC IMPULSE
DIVING SE THRU THE BROADER CYCLONIC FLOW INVOKING A CLOSED H5 LOW
AND SURFACE LOW PRESSURE REFLECTION IN PROXIMITY TO THE 40N/70W
BENCHMARK AROUND MIDNIGHT SUNDAY. WHILE THE THURSDAY-FRIDAY SYSTEM
LOOKS MEDIOCRE...THE SATURDAY-SUNDAY SYSTEMS APPEARS TO HAVE MORE
POTENCY AND A MORE PLOWABLE SNOW.
ASSOCIATED ENERGY IS STILL WELL N OVER THE ARCTIC...POORLY SAMPLED.
BUT THAT DOES NOT DETER FROM EVALUATING. AS HAS BEEN THE PATTERN
WITH ROBUST SYSTEMS THIS SEASON...AN INITIAL OVER-RUNNING EVENT
TRANSITIONS INTO MORE MESOSCALE BANDING REARWARD OF THE SYSTEM
WITHIN BETTER LOW- TO MID-LEVEL TROWALING / FRONTOGENESIS AS THE
LOW INTENSIFIES DRAWING WARM-MOIST AIR CYCLONICALLY TO ITS CORE.
SIMILAR SIGNALS APPEAR WITH THIS SYSTEM WITH THE MAJORITY OF
IMPACTS ACROSS SE NEW ENGLAND. SOLUTIONS WOBBLE AND ARE SLIGHTLY
PROGRESSIVE WITH AN INCREASINGLY POSITIVE-FORECAST NAO SIGNAL.
QUESTION AS TO WHETHER OUTCOMES ARE COMPLICATED BY THE NON-CLASSIC
DOUBLE-BARREL H5 LOW PATTERN FORECAST ACROSS THE NE- CONUS. STILL
PLENTY OF TIME TO CHEW ON THIS ONE. SHOULD PROBABLY GET THROUGH
THE THURSDAY-FRIDAY STORM FIRST.
SUNDAY NIGHT INTO EARLY NEXT WEEK...
AS HAS BEEN THE CASE OVER THE PAST WEEK...DETERMINISTIC/ENSEMBLE-
MEMBER SOLUTIONS HAVE SIGNALED A DECENT ARCTIC AIR OUTBREAK TOWARDS
MID-FEBRUARY. CIPS ANALOGS CONTINUE TO CONVEY HIGH CONFIDENCE
ALONG WITH THE FORECAST CONSENSUS AVERAGE OF H85 TEMPS FALLING BELOW
-20C FOR THE PERIOD RESULTING IN HIGHS ONLY INTO THE TEENS WITH
LOWS WELL BELOW-ZERO INTO MONDAY. A BELOW-NORMAL PATTERN CONTINUING
FOR THE REST OF THE EARLY WEEK PERIOD LOCKED IN BY HIGH PRESSURE.
WIND-CHILL HEADLINES WILL LIKELY NEED TO BE ENTERTAINED FOR THE
SATURDAY NIGHT INTO MONDAY MORNING TIMEFRAME.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TONIGHT/...MODERATE CONFIDENCE.
15Z UPDATE...
TODAY...HIGH CONFIDENCE.
INTERIOR VFR WITH AREAS OF MVFR/IFR IN OCEAN EFFECT SNOW E MA.
MVFR CONDITIONS EXTENDING INTO RI. LIGHT ACCUMS UPWARDS OF 2
INCHES IN SPOTS...GENERALLY AROUND 1-INCH. NE WIND GUSTS TO 25-35
KT SE COASTAL MA AND CAPE/ISLANDS WILL BEGIN TO DIMINISH AFT 18Z.
TONIGHT...HIGH CONFIDENCE.
MVFR E MA/RI WITH -SN LINGERING. CONTINUED MVFR-IFR VSBYS WITH -SN
TOWARDS 6Z. VFR W WITH INCREASING MID-HIGH CIGS. N/NE-WINDS
DIMINISH GUSTING UPWARDS AROUND 25 KTS.
KBOS TAF...MODERATE CONFIDENCE IN TAF. MVFR VSBYS POSSIBLE WITH
-SN. HELD WITH -6SM. PRESENT N/NW-WINDS ARE EXPECTED TO KEEP THE
MORE MODERATE SNOW S OF THE TERMINAL.
KBDL TAF...HIGH CONFIDENCE IN TAF. WILL HOLD VFR THROUGHOUT.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY INTO FRIDAY...MODERATE CONFIDENCE.
MAJORITY OF IMPACTS OVER SE NEW ENGLAND ESP CAPE COD / ISLANDS. -SN.
MVFR-LIFR IMPACTS. INCREASING NW-WINDS INTO FRIDAY...TAPERING LATE.
GUSTS 25-30 KTS... STRONGER ACROSS THE COAST UP AROUND 35 KTS.
FRIDAY NIGHT INTO EARLY SATURDAY...MODERATE CONFIDENCE.
VFR. NW-WINDS DIMINISHING. BRIEF PERIOD OF SKC PRIOR TO
INCREASING MID- TO HIGH-LEVEL CIGS LATE.
SATURDAY INTO SUNDAY...LOW CONFIDENCE.
ANOTHER STORM SYSTEM. FOCUS OF IMPACTS ACROSS E/SE NEW ENGLAND.
MVFR-LIFR IMPACTS WITH SNOW. LLWS IMPACTS POSSIBLE DURING ONSET
WITH N/NE WINDS AT THE SURFACE AND BREEZY SW-WINDS 2 KFT AGL
ALOFT. OTHERWISE RETURN OF BLUSTERY NW-WINDS IN WAKE OF THE STORM.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TONIGHT/...HIGH CONFIDENCE.
7 AM UPDATE...NO MAJOR CHANGES.
NE WINDS WILL CONTINUE TO GUST TO 35-40 KT ON THE SOUTHERN WATERS
THIS MORNING...BUT SHOULD START TO DIMINISH TO SMALL CRAFTS
BEGINNING AROUND MIDDAY ON THE NEAR SHORE BAYS/SOUNDS. CONTINUES
SMALL CRAFTS THROUGH TONIGHT. WINDS WILL DIMINISH TONIGHT AS LOW
PRES WELL S OF NEW ENGLAND MOVES AWAY AND HIGH PRES RIDGE BUILDS
ACROSS. HOWEVER...SEAS WILL REMAIN HIGH FROM LEFTOVER SWELLS FROM
THE LOW. LIGHT FREEZING SPRAY EXPECTED THROUGH THIS EVENING.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY INTO FRIDAY...MODERATE CONFIDENCE.
MAJORITY OF IMPACTS OVER SE NEW ENGLAND ESP CAPE COD / ISLANDS.
LIGHT SNOW. VISIBILITY IMPACTS OVER THE WATERS. INCREASING NW-
WINDS INTO FRIDAY WITH GALE FORCE GUSTS AND WAVES BUILDING 8 TO 10
FEET ON THE OUTER WATERS...BOTH OF WHICH TAPERING LATE FRIDAY.
FRIDAY NIGHT INTO EARLY SATURDAY...MODERATE CONFIDENCE.
NW-WINDS DIMINISHING VEERING W. HIGH PRESSURE BUILDING INTO THE
WATERS. SEAS DROPPING BELOW 5 FEET BY SATURDAY MORNING.
SATURDAY INTO SUNDAY...LOW CONFIDENCE.
ANOTHER STORM SYSTEM. FOCUS OF IMPACTS ACROSS E/SE NEW ENGLAND.
SNOW ANTICIPATED RESULTING IN VISIBILITY RESTRICTIONS OVER THE
WATERS. OTHERWISE RETURN OF BLUSTERY NW-WINDS IN WAKE OF THE STORM
TO GALE FORCE BEGINNING SUNDAY MIDNIGHT. POTENTIAL FOR GUSTS UP TO
AROUND 45 KTS SUNDAY. SEAS POTENTIALLY BUILDING UP TO 20 FEET ON
THE OUTER WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...GALE WARNING UNTIL 3 PM EST THIS AFTERNOON FOR ANZ232-256.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
ANZ233>235-237.
SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR ANZ230.
SMALL CRAFT ADVISORY UNTIL 4 AM EST THURSDAY FOR ANZ231.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ236.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THURSDAY FOR ANZ250-251.
GALE WARNING UNTIL 5 PM EST THIS AFTERNOON FOR ANZ254-255.
&&
$$
SYNOPSIS...SIPPRELL/EVT
NEAR TERM...KJC
SHORT TERM...EVT
LONG TERM...SIPPRELL
AVIATION...KJC/SIPPRELL/EVT
MARINE...SIPPRELL/EVT
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1012 AM EST WED FEB 11 2015
.SYNOPSIS...
A HIGH PRESSURE SYSTEM OVER SOUTHERN QUEBEC PROVINCE WILL SLOWLY
EASE EAST TODAY AND TONIGHT. A COLD FRONT WILL CROSS THE AREA ON
THURSDAY, WITH A STRONG LOW PRESSURE SYSTEM DEVELOPING ALONG THIS
FRONT AND INTENSIFYING RAPIDLY AS IT MOVES SOUTHEAST OF CAPE COD. AN
ARCTIC HIGH PRESSURE SYSTEM WILL MOVE OVER THE REGION ON FRIDAY.
ANOTHER LOW PRESSURE SYSTEM MOVING THROUGH THE EASTERN GREAT LAKES ON
SATURDAY IS PREDICTED TO INTENSIFY EVEN MORE RAPIDLY AS IT PASSES
SOUTH OF LONG ISLAND ON SATURDAY NIGHT. ANOTHER ARCTIC HIGH
PRESSURE SYSTEM SHOULD THEN REACH THE MISSISSIPPI VALLEY ON
SUNDAY AND THE APPALACHIANS ON MONDAY. A LOW PRESSURE SYSTEM
SHOULD REACH THE TENNESSEE VALLEY ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AN AREA OF LOW PRESSURE THAT WAS LOCATED ABOUT 500 MILES OFF THE
MID-ATLANTIC COAST THIS MORNING WILL CONTINUE TO DRIFT OUT TO SEA
TODAY. ANOTHER AREA OF LOW PRESSURE WAS ANALYZED OVER LAKE SUPERIOR.
THIS ALBERTA CLIPPER WILL MOVE E-SEWD ACROSS THE UPPER GREAT LAKES.
THE EASTERN SEABOARD WILL BE POSITIONED BETWEEN BOTH OF THESE LOWS
WITH A WEAK RIDGE RIDGE EXTENDING SOUTHWARD FROM ARCTIC HIGH
PRESSURE THAT IS ANCHORED NEAR THE QUEBEC-LABRADOR BORDER.
THE FORECAST AREA WILL BE DRY TODAY WHILE MOST LOCATIONS. HIGH
CLOUDS WILL INCREASE THIS AFTERNOON AS AN UPPER TROUGH APPROACHES
FROM THE OH VALLEY, BUT GENERALLY MOST SUNNY SKIES ARE EXPECTED. THE
ONE EXCEPTION IS ALONG THE NJ AND DE COAST WHERE STRATOCU HAS BEEN
PERSISTENT. A LOOP OF THE MORNING VISIBLE SATELLITE IMAGERY SHOWED
SOME CLEARING ON THE WESTERN EDGE OF THE MARINE CLOUDS ALONG THE
COAST FROM ACY NORTHWARD. FORECAST RH FIELDS FROM THE RAP WERE USED
AS A PROXY FOR PREDICTING THE EVOLUTION OF THE STRATOCU SINCE THIS
MODEL SEEMED TO HAVE HAD A GOOD HANDLE ON IT THIS MORNING. THE RAP
SIMULATES THESE CLOUDS EXPANDING SLIGHTLY INLAND IN NJ THIS
AFTERNOON, PRESUMABLY IN RESPONSE TO THE DEEPER MIXING ON LAND.
MADE ONLY MINOR TWEAKS TO THE TEMPS TODAY, MAINLY DECREASE MAX TEMPS
1-3F ALONG THE IMMEDIATE COAST (DUE TO THE STUBBORN MARINE CLOUDS)
AND RAISE MAX TEMPS BY THE SAME MAGNITUDE FARTHER INLAND. OVERALL,
MAX TEMPS ABOUT 5F BELOW NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
CLOUD COVER WILL INCREASE AND LOWER THROUGH THE NIGHT AHEAD OF AN
APPROACHING CLIPPER SYSTEM. NOT MUCH IN THE WAY OF PRECIPITATION IS
EXPECTED FOR MOST OF THE AREA THROUGH THE OVERNIGHT HOURS, BUT SOME
SNOW SHOWERS MAY BEGIN MAKING THEIR WAY INTO THE FAR NORTHWESTERN
AREAS OVERNIGHT AND TOWARD DAYBREAK THURSDAY AS MOISTURE INCREASES
AND SOME LOW LEVEL LIFT MOVES INTO THE AREA.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THIS TIME PERIOD WILL BE DOMINATED BY A PAIR OF ARCTIC OUTBREAKS OF
VERY COLD AIR RIVALING THE OUTBREAKS FROM JANUARY 2014. THE
COMBINATION OF TEMPERATURE AND POSSIBLY ADVISORY LEVEL WIND GUSTS
WILL PRODUCE MODERATE TO HIGH IMPACT THREAT FROM WIND CHILLS.
THERE ARE ALSO THREE SHOTS AT SNOW IN THE LONG TERM. SINCE TWO OF
THEM INVOLVE MILLER B SYSTEMS, THERE REMAINS HIGHER UNCERTAINTY AS
TO THEIR IMPACT IN OUR AREA. THE FINAL LOW IS A MORE CONVENTIONAL
ONE PREDICTED TO ARRIVE FROM THE SOUTHERN PLAINS. ITS THE LAST IN
THE SERIES AND ITS LATITUDINAL SHIFTS WILL IMPACT PTYPE. WE SHOULD
HAVE A BETTER HANDLE ON THAT ONE FURTHER IN ADVANCE AS OPPOSED TO
VALENTINE`S NIGHT LOW WITH ITS NORLUN TROF FEATURE THAT IS MORE OF
A BEAR TO ACCURATELY FORECAST MUCH IN ADVANCE.
LIKE LAST NIGHT, THE GFS INITIALIZATION AT 850MB AND 500MB LOOKED
SLIGHTLY POORER THAN THE WRF-NMMB AND LIKE LAST NIGHT ITS 925MB
INITIALIZATION WAS BETTER. UNLIKE LAST NIGHT THE GEFS MEAN SUPPORTS
THE OPERATIONAL GFS AND THE GFS AND ECMWF RUNS ARE PRETTY SIMILAR.
THEY WERE USED WITH SOME WPC BLENDING FOR THE LONG TERM.
FOR THURSDAY NOW THAT THE GFS HAS JOINED THE OTHER MODELS WITH A
MORE SUBDUED SECONDARY CYCLOGENESIS ON THURSDAY, OUR PREDICTED SNOW
HAS COME DOWN A NOTCH CLOSER TO THE COAST WITH LESS THAN AN INCH
SOUTH OF THE INTERSTATE 78 CORRIDOR. WE KEPT AN INCH TO TWO NORTH
BECAUSE THE BURLINGTON WINDEX TOOL IS INDICATING MORE INTENSE SNOW
SHOWERS LIKELY. BECAUSE OF THE VORT MAX POSITIONING, THIS MAY OCCUR
ANYWHERE IN OUR CWA, BUT THE SOUTHERN PART OF OUR CWA SHOULD HAVE
SOME MELTING ISSUES (MAYBE EVEN SOME RAIN DURING LIGHTER
INTENSITIES) AS THE MODELS HAVE TRENDED WARMER. ALSO DEEPER
MOISTURE IS NORTH AS ARE OUR HIGHEST POPS. WE HAVE EFFECTIVELY
DOUBLED POPS BECAUSE OF THE PREDICTED PASSING OF THE VORT MAX. THE
COLD BIAS IN BOTH THE 2M AND STAT GUIDANCE TEMPS CONTINUES ON NON
PRECIPITATING DAYS. GIVEN THE AFTERNOON ARRIVAL OF THE VORT MAX,
WE SIDED WITH HIGHER STAT GUIDANCE FOR MAX TEMPS.
FARTHER OFFSHORE DEVELOPMENT ALSO MEANS LESS LINGERING OF PCPN
CHANCES. THE TROF AXIS ITSELF IS ALSO A BIT FASTER. POPS WERE
REDUCED THU EVENING. AS THE LOW INTENSIFIES OFFSHORE, (IT IS SLOWER
THAN LAST NIGHT, NOW ABOUT 20MB/24HRS) THE GRADIENT IS PREDICTED TO
TIGHTEN. THE GFS BRINGS WIND ADVISORY LEVEL GUSTS, WHILE THE
WRF-NMMB AND ECMWF COME UP A LITTLE SHORT. GIVEN THE DP/DT HAS BEEN
FOR LATER INTENSIFICATION, WE KEPT WIND GUSTS BELOW ADVISORY LEVELS.
REGARDLESS, MUCH COLDER AIR WILL BE ARRIVING AND WIND CHILL
ADVISORY LEVELS MIGHT BE REACHED IN THE POCONOS WITH SUB ZERO WIND
CHILL APPARENT TEMPS ELSEWHERE. SINGLE NUMBER MINS SHOULD PREVAIL
NORTHWEST OF THE FALL LINE WITH ALL OTHER MINS IN THE MID TEENS OR
LOWER.
THE THERMAL TROF PASSES FRIDAY MORNING WITH SOME MODIFICATION OF THE
AIR MASS STARTING FROM AN EXTREMELY LOW POINT. WINDS SHOULD DECREASE
AS THE DAY PROGRESSES. BUT, MAX TEMPS WILL BE LOWER THAN THE NORMAL
MIN TEMPS. BANKING ON CLOUDINESS ASSOCIATED WITH THE GREAT LAKES
LOW TO HOLD TEMPERATURES UP ON FRIDAY NIGHT. WITH LIGHT WINDS IF
THIS DOES NOT OCCUR, OUR MINS, ESPECIALLY NORTH, WILL BE TOO WARM BY
AS MUCH AS 10 DEGREES.
THEN ALL EYES WILL BE ON THE REDEVELOPMENT OF THE GREAT LAKES LOW.
AN EXTREMELY COLD PIECE OF THE PV IS FORECAST TO PASS ACROSS OUR CWA
AND INITIATE CYCLOGEN OFF THE MID ATLC COAST. IN FACT BOTH THE CAN
GGEM AND ECMWF HAVE A TERTIARY CYCLOGEN UNDERNEATH THE 500MB CLOSED
LOW ON SATURDAY NIGHT. BESIDE INCREASING THE NORLUN TROF CHANCES OF AN
AXIS OF HEAVIER SNOW (THIS HAS BEEN BOUNCING AROUND SOUNDING RUN TO
SOUNDING RUN BETWEEN NJ AND LONG ISLAND), IT TIGHTENS THE GRADIENT
TO THE POINT THAT ADVY LEVEL WIND GUSTS WOULD BE REACHED. HIGH WINDS
NOT OUT OF THE QUESTION EITHER. BUT, THIS SYSTEM HAS YET TO ENTER
CANADA AND WHILE THE GFS AND ECMWF INITIALIZATION LOOKED GOOD, ITS
STILL COMING FROM A RATHER DATA SPARSE AREA. COMING FROM FRIDAY`S
PERSPECTIVE, THE SOUTHERLY FLOW PRECEDING THIS LOW WILL MAKE
SATURDAY FEEL BETTER EVEN THOUGH MAX TEMPS SHOULD STILL BE ABOUT
10 DEGREES COLDER THAN NORMAL.
THEN THE TEETH OF THE ARCTIC OUTBREAK IS EXPECTED ON SUNDAY INTO
MONDAY AS WE SHOULD EXPERIENCE THE COLDEST FEBRUARY WEATHER SINCE
1996 AND BEYOND THAT WE`D BE GOING BACK TO 1979. VICIOUSLY COLD ON
SUNDAY WITH STILL STRONG WINDS AROUND THE DEPARTING LOW. WIND
CHILL ADVISORY LEVEL TEMPS MIGHT OCCUR NORTH WITH MORE WIDESPREAD
WIND CHILL ADVISORY AND POSSIBLY WIND CHILL WARNING LEVEL APPARENT
TEMPS ON SUNDAY NIGHT. HIGH TEMPERATURES ON SUNDAY SHOULD NOT MOVE
MUCH AND SUNDAY NIGHT SHOULD BE THE COLDEST NIGHT OF THE OUTBREAK.
THERE WILL BE A TEMPERATURE RECOVERY ON MONDAY AND WINDS SHOULD
FINALLY DIMINISH. IN FACT TEMPERATURES MAY JUST KEEP ON RISING
THROUGH MONDAY NIGHT INTO TUESDAY.
A LOW PRESSURE SYSTEM EMERGING FROM THE TENNESSEE VALLEY WOULD BRING
PRECIPITATION INTO OUR AREA BY TUESDAY DAY. INITIALLY COLD ENOUGH
FOR SNOW. THE MODELS ARE RETROGRADING THE 500MB RIDGE TO THE POINT
THAT THIS LOW MIGHT BE ABLE TO CUT NORTHWEST OF US. PLENTY OF MOVING
PARTS AND WOULDNT BANK ON THIS. PLUS THE DEEP FREEZE TEMPS
LEADING INTO THIS WOULD PROLONG ICING POTENTIAL IF PTYPE IS NOT
SNOW.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR TODAY AND THIS EVENING. THE ONE AIRPORT WE HAVE TO WATCH FOR MVFR
CIGS THIS AFTERNOON INTO TONIGHT IS ACY. STRATOCU OFF THE WATERS
HAD ERODED NEAR ACY JUST AFTER SUNRISE THIS MORNING. HOWEVER,
LATEST GUIDANCE TRIES TO BRING THE LOW CLOUDS BACK INLAND TO ACY
AFTER 18Z TODAY.
CLOUDS WILL INCREASE LATE IN THE DAY AND LOWER TONIGHT. MVFR CIGS
MAY BEGIN MOVING INTO THE AREA OVERNIGHT OUT TOWARD ABE/RDG AND
DURING THE EARLY MORNING THURSDAY FARTHER EAST.
N-NE WINDS AROUND 10 KT THIS MORNING WILL OCCASIONALLY GUST TO 20
KT. WINDS WILL VEER MORE OUT OF THE E-NE THIS AFTERNOON AND
EVENING AOB 10 KT. LIGHT AND VARIABLE WINDS OVERNIGHT.
OUTLOOK...
WEDNESDAY NIGHT...MAINLY VFR. SOME MVFR CONDITIONS POSSIBLE LATE
NORTHWEST AIRPORTS.
THURSDAY...VFR START. HOWEVER, SNOW COULD REDUCE CONDITIONS INTO THE
MVFR OR IFR CATEGORY, ESPECIALLY AT NORTHERN AIRPORTS AND TERMINALS.
THURSDAY NIGHT THROUGH FRIDAY NIGHT...MAINLY VFR. VERY STRONG AND
GUSTY NORTHWEST WINDS LIKELY EXCEEDING 30 KNOTS. WINDS DECREASING
FRIDAY NIGHT.
SATURDAY INTO SATURDAY NIGHT...A CHANCE OF SNOW COULD ONCE AGAIN
REDUCE CONDITIONS IN THE MVFR OR IFR CATEGORY. INCREASING NORTHWEST
WINDS SATURDAY NIGHT.
SUNDAY...VFR BUT VERY WINDY (GUSTS COULD EXCEED 40 KNOTS) AND VERY
VERY COLD.
&&
.MARINE...
SCA WAS ALLOWED TO EXPIRE FOR THE LOWER DE BAY AT 10 AM AS WIND
GUSTS HAVE DIMINISHED TO 15 KT OR LESS. SCA CONTINUES FOR THE
COASTAL ZONES WITH GUSTS STILL AROUND 25 KT THIS MORNING. SEAS
HAVE ARE STILL HIGH THIS MORNING, RANGING FROM 9-13 FT. THE SCA
MAY BE ABLE TO BE CONVERTED TO A HAZARDOUS SEAS SCA WITH WINDS
BECOME LIGHT LATE IN THE DAY THROUGH THURSDAY MORNING WHILE SEAS
WILL STILL REMAIN ELEVATED.
OUTLOOK...
THURSDAY...SEAS ON THE OCEAN NECESSITATED EXTENDING THE SMALL CRAFT
ADVISORY THROUGH THE DAY. SUB SMALL CRAFT ADVISORY ON DELAWARE BAY.
THURSDAY NIGHT AND FRIDAY...WE ISSUED A GALE WATCH FOR NORTHWESTERLY
GALE FORCE GUSTS. ALSO POSSIBLY MODERATE FREEZING SPRAY.
FRIDAY NIGHT...WINDS DECREASING TO SUB SMALL CRAFT ADVISORY AS THE
NIGHT PROGRESSES.
SATURDAY...WINDS SHOULD BE INCREASING RAPIDLY LATER IN THE DAY AND
SATURDAY NIGHT POSSIBLY REACHING GALE CRITERIA. FREEZING SPRAY.
SUNDAY...SUSTAINED GALE FORCE WINDS ARE POSSIBLE. STORM FORCE GUSTS
POSSIBLE. MODERATE FREEZING SPRAY, POSSIBLY BECOMING HEAVY SUNDAY
NIGHT.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR
ANZ430-431-450>455.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THURSDAY FOR ANZ450>455.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ431.
&&
$$
SYNOPSIS...GIGI
NEAR TERM...KLEIN
SHORT TERM...ROBERTSON
LONG TERM...GIGI
AVIATION...GIGI/KLEIN
MARINE...GIGI/KLEIN
AREA FORECAST DISCUSSION
NWS TOPEKA KS
541 AM CST Wed Feb 11 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 325 AM CST WED FEB 11 2015
Next in a series of cold fronts making its way southward toward the
CWA at this hour. Increasing northerly winds and stratus are
expected Eastern Kansas through the morning hours. Strong shortwave
also noted over southern Colorado, streaming stratus to the east
over Western Kansas, however energy dropping into the back of this
system should drive this southward through the day today and leave
little impact over our area.
Cold air advection continues through the day today. This combined
with stratus early should hold high temperatures only in the 30s to
near 40 this afternoon, however northerly winds will leave it
feeling like highs in the 20s to low 30s. NAM is more aggressive
with keeping clouds over the area while HRRR and GFS/EC indicate
subsidence and clearing for at least a portion of the day today.
Evening hours bring a break in the winds and the clouds, however
secondary cold front advances southward across the area after
midnight and brings in even colder temperatures in the teens. Given
north winds of 15 to 20 mph, also anticipate wind chill values near
zero, and as low as -10 near in the far northeastern counties by
early Thursday.
.LONG TERM...(Thursday through Tuesday)
Issued at 325 AM CST WED FEB 11 2015
Northwest flow aloft keeps temperatures as the main challenge into
the weekend. Surface high comes in Thursday for decreasing winds,
but the cold air in place will keep temps about 10F colder than
today. Still appears temps may be rather steady or slowly rise late
Thursday night as warm air surges back east ahead of next strong
upper wave rotating around the persistent upper level trough in the
east. This continues to suggest a much warmer Friday than recent
days, but the weekend periods bring much colder temps again with
cold front coming through late Friday night into Saturday. Have a
rather high temperature spread across the area Saturday and timing
of best cold air advection varies so confidence on specifics is low.
Limited mixing in 850mb temps around -8 C brings an even colder
Sunday.
Final few periods of this forecast bring increasing precipitation
chances. There is fairly good operational and ensemble agreement in
the western upper ridge redeveloping off the coast for a more zonal
to even southwest flow taking shape early in the week. Resulting
deep isentropic lift should be able to saturate enough of the column
for precip chances as early as late Sunday night but with greater
chances Monday into Monday night. Precip type looking more
challenging than most normal long-range forecasts with questions on
depth of moisture to produce ice in the cloud and the potential for
an above-freezing layer to develop under still cold near-surface
conditions.
&&
.AVIATION...(For the 12Z TAFs through 12Z Thursday Morning)
Issued at 539 AM CST WED FEB 11 2015
MVFR cigs continue for the morning and potentially into the
afternoon hours at all TAF sites, although some guidance
suggesting deck could become scattered after only a few hours.
Breezy northerly winds continue today, take a break late afternoon
into the evening hours, then another front increases winds again
toward end of the TAF period.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...67
LONG TERM...65
AVIATION...67
AREA FORECAST DISCUSSION
NWS GOODLAND KS
438 AM MST WED FEB 11 2015
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 246 AM MST WED FEB 11 2015
UPPER FLOW WILL BE NORTHWEST THROUGH FRIDAY NIGHT WITH A AMPLIFIED
RIDGE OVER THE WESTERN CONUS. SURFACE HIGH PRESSURE WILL MOVE INTO
THE CENTRAL PLAINS TODAY AND TONIGHT. A TROUGH WILL MOVE INTO
EASTERN COLORADO THURSDAY/THURSDAY NIGHT AS HIGH PRESSURE SHIFTS
EAST. HIGH PRESSURE WILL MOVE INTO THE REGION BEHIND THE EXITING
SURFACE TROUGH FRIDAY/FRIDAY NIGHT.
SUBSIDENCE WILL FOLLOW THE EXITING SHORTWAVE THIS MORNING AND
CONTINUE THROUGH TONIGHT. A WEAK SHORTWAVE IS NOTED IN THE FLOW ON
THURSDAY BUT MOISTURE IS WELL TO THE EAST OF THE FA SO THAT
PRECIPITATION SHOULD BE UNLIKELY. SUBSIDENCE FOLLOWS THE EXITING
SHORTWAVE THURSDAY NIGHT AND CONTINUES THROUGH FRIDAY NIGHT. AS A
RESULT, ALL PERIODS WILL BE DRY WITH NIL POPS.
NAM BOUNDARY LAYER RH INCREASES TO 90 PERCENT AS THE COLD FRONT
MOVES INTO THE FA THIS MORNING. THE HRRR INDICATES CEILINGS OF
AROUND 1000FT. THE LOWER CEILINGS WILL MOVE OUT OF THE SOUTHERN FA
BY 17Z ACCORDING TO THE HRRR.
850 TEMPERATURES INDICATE SEASONABLE TEMPERATURES TODAY IN THE MID
40S AND THEN WARMING UP TO THE LOWER 60S IN EASTERN COLORADO
THURSDAY WITH MID 50S IN NORTHWEST KANSAS. MAX TEMPERATURES FRIDAY
SHOULD RISE TO NEAR 60. MIN TEMPERATURES SHOULD COOL TO THE LOWER
TO MID 20S TONIGHT AND THEN MODERATE TO THE LOWER 30S THURSDAY AND
FRIDAY NIGHTS.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 246 AM MST WED FEB 11 2015
SATURDAY THROUGH TUESDAY WILL SEE TEMPERATURES RETURNING TO MORE
NORMAL VALUES AS A COOLER AIR MASS MOVES OVER THE AREA BEGINNING
SATURDAY...AS WELL AS A CHANCE FOR PRECIPITATION EARLY NEXT WEEK.
OVER THE WEEKEND THE UPPER LEVEL RIDGE THAT HAS BEEN SITUATED OVER
THE GREAT BASIN WILL BE PUSHED BACK WEST AS A STRONGER UPPER LEVEL
TROUGH MOVES SOUTHEAST OUT OF CANADA. THE TROUGH WILL DEEPEN AS IT
MOVES SOUTHEAST ACROSS THE CONUS. AS IT DOES SO THE UPPER LEVEL
FLOW WILL RESEMBLE MORE OF A SPLIT FLOW SETUP...PRIOR TO THE
TROUGH REACHING THE HIGH PLAINS. IF THIS PATTERN DOES DEVELOP
THERE WILL BE VERY LITTLE CHANCE FOR PRECIPITATION MONDAY NIGHT
DUE TO THE UPPER LEVEL FORCING GOING AROUND THE AREA. HOWEVER WILL
LEAVE IN THE CONSENSUS OF MINIMAL CHANCES FOR PRECIPITATION AS THE
TROUGH MOVES THROUGH.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 431 AM MST WED FEB 11 2015
STRATUS CIGS WILL CONTINUE AT KGLD AND KMCK UNTIL AROUND 16Z AND
THEN MOVE OUT PRDUCING VFR CONDITIONS. WINDS WILL BE BREEZY TODAY
BEHIND THE COLD FRONT. WINDS WILL BECOME LIGHT AND VARIABLE
TONIGHT AS ANOTHER BATCH OF CLOUDS MOVE THROUGH WITH VFR
CONDITIONS PERSISTING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...FS
LONG TERM...JTL
AVIATION...FS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
634 AM EST WED FEB 11 2015
.SYNOPSIS...
A LATE DAY COLD FRONT WILL BEGIN THE TRANSITION TO FRIGID TEMPERATURES
WHICH WILL PERSIST INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
OVERALL...A SOFT DAY IS ANTICIPATED FOR THE UPPER OHIO REGION AS
A STRONG SHORTWAVE TROUGH...WITH AXIS OVER THE UPPER MISSISSIPPI
VALLEY THIS MORNING...PROGRESSES OVER THE GREAT LAKES. WARM
ADVECTION IN ADVANCE OF THAT SYSTEM SHOULD SUPPORT HIGHS NEAR THE
MID FEBRUARY AVERAGES DESPITE A CLOUD INCREASE WITH THE MID LEVEL
MOISTURE SURGE. THE TEMPERATURE FORECAST WAS TWEAKED USING THE
LATEST SREF...NAM...AND RAP GUIDANCE TRENDS...BUT CHANGES WERE
MINIMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
THE ACTUAL COLD FRONT PASSAGE IS NOT EXPECTED TO BE DRAMATIC AS
FAR AS PRECIPITATION IS CONCERNED WITH THE LOW CENTER PROJECTED
TOWARD NEW YORK AND A MID LEVEL DRY SLOT RAPIDLY ENCROACHING INTO
UPPER OHIO VALLEY AIRSPACE. HOWEVER...THURSDAY TEMPERATURES WILL
BE ON THE DECLINE...WITH SNOW SHOWER COVERAGE INCREASING UNDER A
FRIGID MID LEVEL THERMAL TROUGH.
THE STEEPENING LOW LEVEL LAPSE RATES AND A SHALLOW DENDRITIC
GROWTH ZONE WILL RESULT IN INCREASED CONVECTIVE SNOW SHOWER
ACCUMULATION POTENTIAL ON THURSDAY...ESPECIALLY IN THE USUAL
UPSLOPE AREAS OF THE RIDGES AND ZONES IN LEE OF THE LAKES. NOT
MUCH CHANGE WAS NEEDED FOR THE ONGOING 1-2 FORECAST WITH 2-4
INCHES ON THE RIDGES.
EASTWARD PROGRESS OF THE MAIN MID LEVEL COLD POOL...I.E. FALLING
INVERSION LEVELS WITH DRY ADVECTION SHOULD RAPIDLY LIMIT ADDITIONAL
ACCUMULATION POTENTIAL ON THURSDAY NIGHT.
THE COLD THURSDAY NIGHT AND FRIDAY TEMPERATURE FORECAST WAS NOT
DISPUTED MUCH BY INCOMING GUIDANCE AS A HIGH AMPLITUDE EASTERN
U.S. UPPER TROUGH AXIS IS DEVELOPED SLOWLY EASTWARD...HENCE
CHANGES WERE MINIMAL ALTHOUGH THE WIND WAS REDONE USING NAM AND
GFS GRIDS. WIND CHILL INDICES STILL ARE PROJECTED INTO THE
ADVISORY RANGE OF -10 TO -20C...SO A HAZARDOUS WEATHER OUTLOOK
MENTION WILL BE MAINTAINED WITH A MENTION OF SNOW ACCUMULATION IN
THE RIDGES...WHERE THE BETTER CHANCE FOR AN ADVISORY IS ON
THURSDAY.
NO REPRIEVE IS INDICATED THIS WEEKEND AS THE ECMWF AND GFS SOLUTIONS
ARE OF A STRONG SHORTWAVE ROTATING SOUTHWARD OUT OF THE HUDSON BAY
AREA. THAT SYSTEM AS MODELED WOULD RECARVE THE UPPER TROUGH OVER
THE EASTERN U.S. CURRENT PROJECTIONS ARE THAT THE MID LEVEL LOW
CENTER WILL REMAIN NORTH OF THE AREA...THUS KEEPING THE SNOW FAVORABLE
TROWAL...FRONTOGENESIS REGIONS AT BAY. NEVERTHELESS...A COLD COLUMN
WILL MAINTAIN FRIGID TEMPERATURES AND HIGH SNOW RATIO PARAMETERS.
PRECIPITATION PROBABILITIES WERE BUMPED UP ON SATURDAY IN ACCORDANCE
WITH THESE TRENDS AND GENERALLY ARE IN LINE WITH GFS GRIDS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS UPPER LOW MOVES EAST OF THE REGION...SNOW SHOWERS WILL WIND
DOWN SATURDAY NIGHT WITH SOME LAKE EFFECT CONTINUING INTO SUNDAY.
WITH THE SURFACE HIGH THEN BUILDING INTO THE REGION SUNDAY
NIGHT...WINDS WILL DIMINISH AND ALL SNOW WILL COME TO AN END.
SUNDAY AND SUNDAY NIGHT APPEARS TO BE THE COLDEST 24 HOUR PERIOD
OF THE WINTER SO FAR...WITH HIGHS IN THE SINGLE DIGITS AND LOWS
RANGING FROM 5 ABOVE TO 10 BELOW. WINDS MAY GO LIGHT WITH THE HIGH
PRESSURE CENTER OVERHEAD...WHICH COULD LIMIT JUST HOW LOW WIND
CHILL VALUES GO. LOW MOVES NORTHEAST FROM THE SOUTHERN PLAINS
MONDAY NIGHT INTO TUESDAY. EVEN WITH WARMER TEMPERATURES MOVING IN
BY MONDAY NIGHT...TEMPERATURES WILL REMAIN COLD ENOUGH THAT ALL
PRECIPITATION SHOULD FALL AS SNOW WITH THAT SYSTEM.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
STRATUS CONTINUES TO PLAGUE FKL/DUJ/LBE...WITH FKL RIGHT ON THE
BORDER BETWEEN CLEAR SKIES AND NEAR LIFR CEILINGS. MVFR FOG AT ZZV
AND STRATUS AT FKL/DUJ/LBE SHOULD DIMINISH IN COVERAGE BY MID
MORNING...ALTHOUGH FKL/DUJ COULD POTENTIALLY STAY IN THE STRATUS
THROUGH THE TAF PERIOD. COLD FRONT PUSHES THROUGH THE REGION THIS
EVENING...BRINGING MVFR/IFR RESTRICTIONS AND A SHIFT IN THE
WINDS. STILL UNSURE OF HOW LOW VISIBILITIES WILL DROP WITH
SCATTERED SNOW SHOWERS...BUT HAVE AT LEAST BROUGHT A MENTION OF
SNOW INTO ALL TERMINALS. SNOW WILL NOT BECOME MORE WIDESPREAD
UNTIL THURSDAY...WITH IFR SNOW MENTIONED IN THE 30 HOUR PORTION OF
THE PITTSBURGH TAF.
OUTLOOK.../THURSDAY THROUGH SUNDAY/...
RESTRICTIONS SHOULD DIMINISH THURSDAY NIGHT AS THE SYSTEM MOVES
EAST. PERIODIC RESTRICTIONS ARE THEN LIKELY FRIDAY NIGHT THROUGH
SUNDAY WITH A SERIES OF DISTURBANCES.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
555 AM EST WED FEB 11 2015
.SYNOPSIS...
DEEP LOW PRESSURE OFF THE NORTH CAROLINA COAST WILL PULL SLOWLY
AWAY FROM THE FORECAST AREA TODAY. COLD WEATHER TODAY WILL GIVE
WAY TO A VERY BRIEF WARM-UP ON THURSDAY BEFORE THE NEXT ROUND OF
ARCTIC AIR BEGINS TO ARRIVE EARLY THURSDAY EVENING...AND
CONTINUING THROUGH EARLY FRIDAY. AN EVEN COLDER PUSH OF ARCTIC AIR WILL
ARRIVE LATE SATURDAY NIGHT THROUGH SUNDAY. THE CHILL WILL ABATE ON
MONDAY AND MAY GIVE WAY TO THE NEXT BONAFIDE CHANCE FOR
PRECIPITATION ON TUESDAY OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM WEDNESDAY...POWERFUL LOW PRESSURE LOCATED SEVERAL HUNDRED
MILES EAST OF THE OUTER BANKS WILL MOVE FARTHER AWAY FROM THE
CAROLINAS TODAY. THIS WILL ALLOW A SHORTWAVE RIDGE AND A WEAK
SURFACE RIDGE TO MOVE ACROSS THE AREA THIS EVENING.
THERE IS ONE LAST PIECE OF THIS STORM TO DEAL WITH HOWEVER. A STRONG
SUBSIDENCE INVERSION AROUND 925 MB (2500 FEET AGL) HAS TRAPPED
ATLANTIC MOISTURE THROWN BACK AROUND THE STORM ACROSS EASTERN NORTH
CAROLINA. THESE CLOUDS LOOK LIKE THEY WILL BE QUITE PERSISTENT...
POTENTIALLY HANGING AROUND WILMINGTON THROUGH EARLY AFTERNOON BEFORE
CLEARING FINALLY DEVELOPS.
THE WESTERN EDGE OF THESE CLOUDS IS GOING TO BE VERY TOUGH TO PIN
DOWN. THE LATEST RUC SHOWS CLOUDS CROSSING I-95 AND GOING AS FAR
WEST AS DARLINGTON AND BENNETTSVILLE BEFORE STOPPING. (OTHER MODELS
ARE NOT QUITE THIS FAR WEST.) GIVEN THE THIN VERTICAL DEPTH OF THE
CLOUD DECK THE WESTERN EDGE SHOULD FRAGMENT THROUGH VERTICAL MIXING
AND DRYING OF THE BOUNDARY LAYER FROM ALOFT A COUPLE HOURS AFTER
SUNRISE...WITH THE EROSION THEN WORKING ITS WAY BACK EASTWARD TO THE
COAST. WITH THE CLOUDS I HAVE ADJUSTED TEMPERATURES DOWNWARD
ESPECIALLY IN THE BURGAW/WILMINGTON/SOUTHPORT AREA WITH UPPER 40S
EXPECTED HERE. THE REMAINDER OF THE AREA SHOULD REACH 50-55...
WARMEST WEST OF I-95 IN SOUTH CAROLINA.
TONIGHT CLEAR SKIES ARE EXPECTED WITH CALM WINDS AND GOOD
RADIATIONAL COOLING. LOWS SHOULD RANGE FROM THE LOWER TO MIDDLE
30S...COOLEST ACROSS INTERIOR SE NORTH CAROLINA.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...LONGWAVE PATTERN ALOFT TO REMAIN
RELATIVELY UNCHANGED...WITH THE DEEP UPPER TROF AFFECTING THE
EASTERN 1/3RD TO 1/2 OF THE UNITED STATES...AND UPPER RIDGING
ACROSS THE WESTERN 1/3RD TO 1/2 OF THE UNITED STATES. SHORT WAVE
TROFS OR VORTS ALOFT WILL BE ROTATING THRU THIS LONGWAVE UPPER
TROF...KEEPING IT WELL AMPLIFIED DURING THIS TIME PERIOD. THE MEAN
UPPER LONGWAVE TROF NORTH TO SOUTH AXIS IS PROGGED TO REMAIN EITHER
OVERHEAD OR JUST OFF THE EAST COAST. WHAT THIS MEANS FOR THE ILM
CWA IS FOR CONTINUED BELOW OR WELL BELOW NORMAL TEMPS...WITH ONLY
A BRIEF WARM UP PRIOR TO THE PASSAGE OF THE NEXT UPPER S/W TROF...
OR CLIPPER SINCE THEY ORIGINATE ACROSS WEST-CENTRAL CANADA.
AS FOR THIS TIME PERIOD...A BRIEF WARM UP WILL OCCUR DURING
DAYTIME THU AHEAD OF THE NEXT UPPER S/W TROF. THU MAXES MAY
ACTUALLY REACH THE NORM FOR THIS TIME OF THE YEAR. THE MAIN
DYNAMICS OF THIS UPPER S/W TROF TO REMAIN NORTH OF THE FA THU AFTN
AND NIGHT...ALONG WITH THE SFC LOW THAT RE-DEVELOPS AND
INTENSIFIES OFFSHORE FROM THE NEW ENGLAND COAST. ANY DEEP
MOISTURE AVBL FOR PCPN OCCURRENCE TO REMAIN WELL NORTH OF THE FA.
THE SHALLOW MOISTURE THAT WILL BE AVBL WILL BE USED FOR SCT/BKN
CLOUDS AHEAD AND/OR ALONG THE SFC COLD FRONT. LATEST SREF ALSO
INDICATES THAT NO MEASURABLE PCPN TO ACCOMPANY THIS CFP OR THERE-
AFTER. DRYING OF THE ATM COLUMN AND EXCELLENT CAA OR ARCTIC AIR
ADVECTION...UNDER GUSTY NW WINDS WILL OCCUR THU NIGHT INTO FRI AS
THE SFC LOW NEARLY BOMBS WELL OFFSHORE FROM THE NEW ENGLAND COAST
RESULTING IN A WELL TIGHTENED SFC PG ACROSS THE FA.
AS FOR FRI INTO FRI NIGHT...THE CENTER OF THE ARCTIC HIGH WILL BE
LOCATED OVER THE CENTRAL GULF COAST STATES AND THE BOMBING SFC LOW
WILL BE MOVING THRU THE CANADIAN MARITIMES. AS FOR THE ILM
CWA...THE BRUTAL WINDS WILL DIMINISH DURING FRI INTO FRI NIGHT.
SKIES WILL REMAIN RELATIVELY CLEAR WITH A QUIET AND COLD FRI
NIGHT ON TAP.
OVERALL...USED THE NAM MOS GUIDANCE FOR THE NEAR TERM PERIOD
ESPECIALLY WITH DAYTIME HIGHS. FOR EXAMPLE...A NEARLY 1 TO 2
CATEGORY DIFFERENCE EXISTS FOR THE NAM AND GFS MOS GUIDANCE FOR
THU MAX TEMPS ACROSS THE ILM CWA.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 330 AM WEDNESDAY...FOR THIS UPCOMING WEEKEND THRU SUNDAY
...THE LONGWAVE PATTERN REMAINS RELATIVELY UNCHANGED. A WELL
AMPLIFIED UPPER TROF AFFECTING ROUGHLY THE EASTERN 1/2 OF THE
UNITED STATES...AND AMPLIFIED RIDGING ACROSS ROUGHLY THE WESTERN
1/2 OF THE UNITED STATES. IN FACT...THE MODELS ARE IN DECENT
AGREEMENT IN AMPLIFYING THE EASTERN UPPER TROF TO THE POINT OF
ALLOWING AND PUSHING LIFE THREATENING ARCTIC AIR DOWN THE EAST
COAST INTO THE CAROLINAS LATE SATURDAY NIGHT THRU MONDAY MORNING.
WHEN YOU SEE PROGGED 1000-500MB THICKNESSES APPROACHING 505
DECAMETERS AND 850 TEMPS PROGGED AT LESS THAN -20 DEGREES CELCIUS
ACROSS THE ILM CWA DURING THE MENTIONED TIME PERIOD...WORD NEEDS
TO GET OUT. OTHER THAN THE FORECAST ITSELF...WILL HIGHLIGHT THIS
ARCTIC BLAST IN THE HWO AND LIKELY SUBSEQUENT STATEMENTS AS WE
APPROACH THIS TIME PERIOD. THE GOOD THING THOUGH...IS NO
FROZEN/FREEZING PCPN IS EXPECTED WHILE THIS AIRMASS IS IN PLACE
ACROSS THE FA.
FOR MON INTO TUE...THE AMPLIFIED LONGWAVE UPPER PATTERN LOOKS
LIKE IT WANTS TO FLATTEN OUT SOME. WILL INDICATE SOME IMPROVING
TEMPS FOR BOTH MON INTO TUE ALONG WITH THE NEXT BONAFIDE...ALBEIT
A LOW CHANCE...FOR PCPN ACROSS THE FA. AT THIS POINT...NOT PUTTING
TOO MUCH STOCK THIS FAR OUT IN TIME GIVEN THE CURRENT ACTIVE WX
PATTERN.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 12Z...DEEP LOW PRESSURE WELL OFFSHORE HAS GIVEN US GUSTY NORTH
WINDS ALL NIGHT...AND THIS WILL CONTINUE THROUGH THE MORNING HOURS
UNTIL THE GRADIENT FINALLY WEAKENS THIS AFTERNOON. AN MVFR STRATOCU
CEILING WILL AFFECT SOME OF THE TERMINALS THROUGH 14-15Z...AFTER
WHICH IT WILL PROBABLY ERODE. WE ARE IN BETWEEN SYSTEMS
TONIGHT...WITH LIGHT WINDS EXPECTED AND NEARLY CLEAR SKIES.
EXTENDED OUTLOOK...EXPECT VFR THROUGH THE EXTENDED PERIOD.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM WEDNESDAY...A POWERFUL STORM CENTERED ALONG 70W OFF THE
NORTH CAROLINA COASTLINE WILL MOVE FARTHER OUT TO SEA TODAY. THE
BELT OF STRONGEST NORTHERLY WINDS SURROUNDING THIS STORM HAS ALREADY
CLEARED THE COASTAL WATERS. FOR THIS REASON THE GALE WARNING HAS
BEEN LOWERED TO A SMALL CRAFT ADVISORY. GRADUALLY DIMINISHING WIND
SPEEDS ARE EXPECTED THROUGH THE DAY. BY TONIGHT WINDS WILL BE LIGHT
FROM THE NW AS A TRANSITORY RIDGE MOVES ACROSS THE AREA. WINDS WILL
THEN BACK AROUND TO THE SW OVERNIGHT BEHIND THE DEPARTING RIDGE.
SEAS MAY TAKE SOME TIME TO DECAY AS AN EASTERLY BACKSWELL CONTINUES
THROUGH TONIGHT. DOMINANT WAVE PERIODS OF 6 TO 7 SECONDS THIS
MORNING WILL SHIFT TO 13 SECONDS THIS AFTERNOON AS THE BACKSWELL
REPLACES LOCAL WIND WAVES AS THE PRIMARY WAVE TRAIN. WAVE PERIODS
THIS LONG BEGIN TO "FEEL" BOTTOM IN WATER DEPTHS OF ~400 FEET...SO
INSIDE THE COASTAL WATERS ZONES (0-20 MILES) SWELL HEIGHTS SHOULD
DIMINISH SUBSTANTIALLY FROM THAT OBSERVED FARTHER OFFSHORE.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...THU STARTS OUT DOCILE FOR BOTH WINDS AND
SEAS ACROSS THE FA...BUT QUICKLY DETERIORATES DURING THE DAY AND
CONTINUING ESPECIALLY THU NIGHT THRU MUCH OF DAYTIME FRI. THIS IN
RESPONSE TO YET ANOTHER CLIPPER LOW THAT DIVES EAST-SOUTHEAST FROM
CANADA TO OFF THE NJ-DEL COAST...THEN RAPIDLY INTENSIFIES OR NEARLY
BOMBS OFF THE NEW ENGLAND COAST THU NIGHT INTO FRI...BEFORE SLOWLY
MOVING NE TO THE CANADIAN MARITIMES BY LATE FRI. THE SFC COLD
FRONT TO PUSH ACROSS THE ILM WATERS LATE THU AFTN OR EARLY
EVENING. THE SFC PG WILL TIGHTEN DRAMATICALLY ACROSS THE AREA
WATERS THU NITE INTO FRI...ACCOMPANIED BY EXCELLENT COLD AIR OR
SHOULD I SAY ARCTIC AIR ADVECTION.
SW-WSW WINDS THU AHEAD OF THE COLD FRONT...WILL VEER TO A GUSTY
GALE FORCE NW WIND FOR THU NIGHT INTO EARLY FRI. A GALE WATCH
LIKELY WILL BE NEEDED AT THE NEXT FULL UPDATE DURING WED. RIDGING
FROM THE HIGHS CENTER WILL PUSH ACROSS THE LOCAL WATERS LATE FRI
INTO FRI NIGHT ALLOWING BOTH WINDS AND SEAS TO RESPECTIVELY
DIMINISH AND SUBSIDE. AM SOMEWHAT WORRIED THAT WAVEWATCH3 AND SWAN
ARE NOT HANDLING THE BACK GROUND SWELL FROM THE DEEP LOW THAT IS
CURRENTLY PULLING VERY SLOWLY TO THE EAST. MAY ACTUALLY GO ABOVE
GUIDANCE FOR SIGNIFICANT SEAS DURING THU. THE WIND DRIVEN VARIETY
WILL RULE SIG. SEAS COME THU NIGHT THRU FRI.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 330 AM WEDNESDAY...LOOKING AT THE NEXT CLIPPER LOW TO DIVE
FURTHER SE THAN THE PREVIOUS ONE...REDEVELOPING OFF THE DELMARVA
COAST LATE SATURDAY...THEN LIKELY BOMBING AS IT LIFTS NE TO OFF
THE NEW ENGLAND COAST SUNDAY MORNING. ITS ASSOCIATED SFC COLD
FRONT TO PUSH ACROSS THE LOCAL WATERS DURING SAT NIGHT. THE SFC
PRESSURE GRADIENT WILL QUICKLY TIGHTEN ACROSS THE AREA WATERS
SATURDAY NIGHT THRU SUNDAY...DUE TO THE COMBINED AFFECTS FROM A
1050MB SFC HIGH DROPPING OUT OF CANADA AND A SUB 970MB LOW MOVING
NE OFF THE NEW ENGLAND COAST. ADD ARCTIC AIR ADVECTION TO THE
MIX...AND YOU EASILY HAVE GALE FORCE WINDS LATER SAT NIGHT THRU
SUNDAY. AS FOR SIGNIFICANT SEAS...WILL INITIALLY HAVE TO WATCH FOR
ANY BACK GROUND SWELL ON SATURDAY EMANATING FROM THE INTENSE
NORTH ATLANTIC LOWS. BUT FOR LATE SAT THRU SUNDAY...WIND DRIVEN
WAVES FROM GALE FORCE WINDS WILL DOMINATE THE SIGNIFICANT SEAS.
GALE WARNINGS WILL LIKELY BE NEEDED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR AMZ254-256.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ250-
252.
&&
$$
SYNOPSIS...DCH
NEAR TERM...TRA
SHORT TERM...DCH
LONG TERM...DCH
AVIATION...DL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
951 AM CST WED FEB 11 2015
.UPDATE...
ISSUED AT 951 AM CST WED FEB 11 2015
OTHER THAN TO ADD A SCATTERED FLURRY MENTION UNDER THE STRATUS
THIS MORNING PER SURFACE OBSERVATIONS...THE ONGOING FORECAST IS ON
TRACK FOR TODAY AND TONIGHT. TEMPERATURES WILL SLOWLY FALL FROM
MORNING HIGHS THE REMAINDER OF THE DAY AS COLD HIGH PRESSURE
PROPAGATES INTO THE DAKOTAS.
UPDATE ISSUED AT 641 AM CST WED FEB 11 2015
NO MAJOR CHANGES WERE MADE TO THE ONGOING FORECAST. THE CURRENT
WIND CHILL HEADLINES LOOK GOOD FOR TONIGHT INTO THURSDAY MORNING.
ONLY MADE MINOR ADJUSTMENTS TO THE HOURLY SENSIBLE WEATHER GRIDS.
THE UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 305 AM CST WED FEB 11 2015
THE ISSUANCE OF A WIND CHILL ADVISORY IS THE MAIN HIGHLIGHT IN THE
SHORT TERM PERIOD.
A 1050MB SURFACE HIGH PRESSURE CURRENTLY OVER EAST CENTRAL ALBERTA
WILL SLIDE SOUTHEAST TO NEAR REGINA BY 00Z THURSDAY...NEAR HARVEY
AT 06Z THURSDAY...AND INTO CASSELTON BY 12Z THURSDAY. EXPECT A
MOSTLY CLEAR SKY TO DEVELOP AS THE HIGH APPROACHES THIS AFTERNOON
AND TONIGHT. SUB ZERO LOW TEMPERATURES AND WINDS TO 10 MPH WILL
RESULT IN WIND CHILL TEMPERATURES TO 35 BELOW ZERO. A WIND CHILL
ADVISORY HAS BEEN HOISTED TO REFLECT THIS. THE TURTLE MOUNTAINS
WILL BE THE FIRST AREA TO DROP TO AROUND 25 BELOW BY MID AFTERNOON
TODAY AND THUS HAVE DIVIDED THE ADVISORY OUT INTO TWO AREAS. THE
TURTLE MOUNTAINS WILL BE VALID FROM 21Z WEDNESDAY THROUGH 18Z
THURSDAY...AND REMAINING LOCALES ALONG AND EAST OF THE MISSOURI
RIVER WILL HAVE A VALID TIME OF 00Z THURSDAY THROUGH 18Z THURSDAY.
THE LATEST WATER VAPOR IMAGERY SHOWS A NORTHWEST FLOW INTO NORTH
DAKOTA WITH ARCTIC AIR DESCENDING SOUTH FROM ALBERTA/SASKATCHEWAN.
SUCCESSIVE BUT WEAK SHORTWAVES WITH MOSTLY CHANNELED VORTICITY
POSE A SMALL THREAT FOR LIGHT SNOW IN SOUTHWEST NORTH DAKOTA
TODAY. HIGH RESOLUTION HRRR AND RAP13 INDICATE THIS AND HAVE
MAINTAINED THIS FEATURE FROM PREVIOUS FORECASTS. REGIONAL RADAR
ALREADY PICKING UP ON WEAK REFLECTIVITY`S EMERGING OVER NORTH
CENTRAL MONTANA. THE WINDOW OF OPPORTUNITY FOR LIGHT SNOW IS
ROUGHLY FROM 14Z-20Z TODAY. ELSEWHERE THE FOG/STRATUS LOOP SHOWS A
MOSTLY CLEAR SKY ACROSS THE NORTH CENTRAL WHICH IS WORKING TOWARD
THE SOUTH CENTRAL AT THIS TIME. STILL POCKETS OF STRATUS UPSTREAM.
BUFKIT SOUNDINGS THROUGHOUT THE UPCOMING MORNING MAINTAIN A MOIST
BOUNDARY LAYER...AND ONCE MIXING DEVELOPS BY MID MORNING...EXPECT
A PARTLY TO MOSTLY CLOUDY SKY TO ENSUE FOR A FEW HOURS. CONTINUED
MIXING INTO THE AFTERNOON WILL EVENTUALLY LEAD TO LESS CLOUDS AS
SUBSIDENCE AND DRIER AIR ALOFT GETS ENTRAINED AND LEADS TO
CLEARING CONDITIONS. HENCE WHATEVER CLOUDS TO DEVELOP EARLY ON
TODAY WILL DECREASE DURING THE MID TO LATE AFTERNOON. WARM AIR
ADVECTION DEVELOPS WEST OF THE MISSOURI RIVER WEDNESDAY NIGHT
LEADING TO RISING MOTION AND INCREASING CLOUDS IN THE WEST. THUS
TEMPERATURES NOT QUITE AS COLD WITH MINIMUM TEMPERATURES REMAINING
IN THE SINGLE DIGITS ABOVE ZERO WEST. OVERNIGHT LOWS ALONG AND
EAST OF THE MISSOURI RIVER WILL RANGE FROM 10 TO 20 BELOW
ZERO...AND AS MENTIONED ABOVE WIND CHILL TEMPERATURES TO 35 BELOW
ZERO.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 305 AM CST WED FEB 11 2015
THE MEDIUM RANGE MODELS CAUGHT UP WITH THE ECMWF AND ARE NOW
FORECASTING SNOW DEVELOPING AHEAD OF A WARM FRONT OVER WESTERN AND
CENTRAL NORTH DAKOTA THURSDAY. INCREASED SNOW CHANCES MAINLY
THURSDAY AFTERNOON AS A RESULT. NEW SNOW ACCUMULATIONS SHOULD
REMAIN LESS THAN AN INCH.
A DRY COLD FRONTAL PASSAGE IS THEN PROGGED FRIDAY. COLD CANADIAN
AIR IS EXPECTED TO FILTER INTO THE REGION AGAIN FRIDAY NIGHT INTO
SATURDAY. WIND CHILL HEADLINES MAY BE NEEDED EAST OF THE MISSOURI
RIVER FRIDAY NIGHT.
THE MEDIUM RANGE MODELS ARE COMING INTO BETTER AGREEMENT
FORECASTING A SHORTWAVE AND ITS ATTENDANT FRONT DIVING ACROSS
WESTERN AND CENTRAL NORTH DAKOTA LATE SATURDAY AFTERNOON THROUGH
SUNDAY. INCREASED THE CHANCES FOR SNOW GIVEN THE HIGHER CONFIDENCE
WITH THE LATEST MODEL RUNS. SNOW ACCUMULATIONS LOOK TO BE MORE
THAN PREVIOUSLY FORECAST AS WELL. WIDESPREAD AMOUNTS BETWEEN ONE
AND THREE INCHES LOOK POSSIBLE.
SNOW CHANCES WILL LINGER MONDAY AS A COLD FRONT IS PROGGED TO
PUSH FROM NORTH TO SOUTH. HOWEVER...NEW ACCUMULATIONS APPEAR
LIGHT. DRY AND COLD CONDITIONS ARE FORECAST MONDAY NIGHT THROUGH
TUESDAY AS CANADIAN HIGH PRESSURE SETTLES ACROSS MONTANA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY AFTERNOON)
ISSUED AT 951 AM CST WED FEB 11 2015
MVFR/VFR STRATUS THIS MORNING ACROSS WESTERN AND CENTRAL NORTH
DAKOTA WILL CLEAR THROUGH THE AFTERNOON AS HIGH PRESSURE BUILDS
ACROSS THE AREA. BRIEF FLURRIES ARE POSSIBLE AT KMOT AND KJMS
THIS MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON CST THURSDAY
FOR NDZ001>003-010>013-021>023-025-035>037-046>048-050-051.
WIND CHILL ADVISORY FROM 3 PM THIS AFTERNOON TO NOON CST
THURSDAY FOR NDZ004-005.
&&
$$
UPDATE...AYD
SHORT TERM...KS
LONG TERM...TM
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
641 AM CST WED FEB 11 2015
.UPDATE...
ISSUED AT 641 AM CST WED FEB 11 2015
NO MAJOR CHANGES WERE MADE TO THE ONGOING FORECAST. THE CURRENT
WIND CHILL HEADLINES LOOK GOOD FOR TONIGHT INTO THURSDAY MORNING.
ONLY MADE MINOR ADJUSTMENTS TO THE HOURLY SENSIBLE WEATHER GRIDS.
THE UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 305 AM CST WED FEB 11 2015
THE ISSUANCE OF A WIND CHILL ADVISORY IS THE MAIN HIGHLIGHT IN THE
SHORT TERM PERIOD.
A 1050MB SURFACE HIGH PRESSURE CURRENTLY OVER EAST CENTRAL ALBERTA
WILL SLIDE SOUTHEAST TO NEAR REGINA BY 00Z THURSDAY...NEAR HARVEY
AT 06Z THURSDAY...AND INTO CASSELTON BY 12Z THURSDAY. EXPECT A
MOSTLY CLEAR SKY TO DEVELOP AS THE HIGH APPROACHES THIS AFTERNOON
AND TONIGHT. SUB ZERO LOW TEMPERATURES AND WINDS TO 10 MPH WILL
RESULT IN WIND CHILL TEMPERATURES TO 35 BELOW ZERO. A WIND CHILL
ADVISORY HAS BEEN HOISTED TO REFLECT THIS. THE TURTLE MOUNTAINS
WILL BE THE FIRST AREA TO DROP TO AROUND 25 BELOW BY MID AFTERNOON
TODAY AND THUS HAVE DIVIDED THE ADVISORY OUT INTO TWO AREAS. THE
TURTLE MOUNTAINS WILL BE VALID FROM 21Z WEDNESDAY THROUGH 18Z
THURSDAY...AND REMAINING LOCALES ALONG AND EAST OF THE MISSOURI
RIVER WILL HAVE A VALID TIME OF 00Z THURSDAY THROUGH 18Z THURSDAY.
THE LATEST WATER VAPOR IMAGERY SHOWS A NORTHWEST FLOW INTO NORTH
DAKOTA WITH ARCTIC AIR DESCENDING SOUTH FROM ALBERTA/SASKATCHEWAN.
SUCCESSIVE BUT WEAK SHORTWAVES WITH MOSTLY CHANNELED VORTICITY
POSE A SMALL THREAT FOR LIGHT SNOW IN SOUTHWEST NORTH DAKOTA
TODAY. HIGH RESOLUTION HRRR AND RAP13 INDICATE THIS AND HAVE
MAINTAINED THIS FEATURE FROM PREVIOUS FORECASTS. REGIONAL RADAR
ALREADY PICKING UP ON WEAK REFLECTIVITY`S EMERGING OVER NORTH
CENTRAL MONTANA. THE WINDOW OF OPPORTUNITY FOR LIGHT SNOW IS
ROUGHLY FROM 14Z-20Z TODAY. ELSEWHERE THE FOG/STRATUS LOOP SHOWS A
MOSTLY CLEAR SKY ACROSS THE NORTH CENTRAL WHICH IS WORKING TOWARD
THE SOUTH CENTRAL AT THIS TIME. STILL POCKETS OF STRATUS UPSTREAM.
BUFKIT SOUNDINGS THROUGHOUT THE UPCOMING MORNING MAINTAIN A MOIST
BOUNDARY LAYER...AND ONCE MIXING DEVELOPS BY MID MORNING...EXPECT
A PARTLY TO MOSTLY CLOUDY SKY TO ENSUE FOR A FEW HOURS. CONTINUED
MIXING INTO THE AFTERNOON WILL EVENTUALLY LEAD TO LESS CLOUDS AS
SUBSIDENCE AND DRIER AIR ALOFT GETS ENTRAINED AND LEADS TO
CLEARING CONDITIONS. HENCE WHATEVER CLOUDS TO DEVELOP EARLY ON
TODAY WILL DECREASE DURING THE MID TO LATE AFTERNOON. WARM AIR
ADVECTION DEVELOPS WEST OF THE MISSOURI RIVER WEDNESDAY NIGHT
LEADING TO RISING MOTION AND INCREASING CLOUDS IN THE WEST. THUS
TEMPERATURES NOT QUITE AS COLD WITH MINIMUM TEMPERATURES REMAINING
IN THE SINGLE DIGITS ABOVE ZERO WEST. OVERNIGHT LOWS ALONG AND
EAST OF THE MISSOURI RIVER WILL RANGE FROM 10 TO 20 BELOW
ZERO...AND AS MENTIONED ABOVE WIND CHILL TEMPERATURES TO 35 BELOW
ZERO.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 305 AM CST WED FEB 11 2015
THE MEDIUM RANGE MODELS CAUGHT UP WITH THE ECMWF AND ARE NOW
FORECASTING SNOW DEVELOPING AHEAD OF A WARM FRONT OVER WESTERN AND
CENTRAL NORTH DAKOTA THURSDAY. INCREASED SNOW CHANCES MAINLY
THURSDAY AFTERNOON AS A RESULT. NEW SNOW ACCUMULATIONS SHOULD
REMAIN LESS THAN AN INCH.
A DRY COLD FRONTAL PASSAGE IS THEN PROGGED FRIDAY. COLD CANADIAN
AIR IS EXPECTED TO FILTER INTO THE REGION AGAIN FRIDAY NIGHT INTO
SATURDAY. WIND CHILL HEADLINES MAY BE NEEDED EAST OF THE MISSOURI
RIVER FRIDAY NIGHT.
THE MEDIUM RANGE MODELS ARE COMING INTO BETTER AGREEMENT
FORECASTING A SHORTWAVE AND ITS ATTENDANT FRONT DIVING ACROSS
WESTERN AND CENTRAL NORTH DAKOTA LATE SATURDAY AFTERNOON THROUGH
SUNDAY. INCREASED THE CHANCES FOR SNOW GIVEN THE HIGHER CONFIDENCE
WITH THE LATEST MODEL RUNS. SNOW ACCUMULATIONS LOOK TO BE MORE
THAN PREVIOUSLY FORECAST AS WELL. WIDESPREAD AMOUNTS BETWEEN ONE
AND THREE INCHES LOOK POSSIBLE.
SNOW CHANCES WILL LINGER MONDAY AS A COLD FRONT IS PROGGED TO
PUSH FROM NORTH TO SOUTH. HOWEVER...NEW ACCUMULATIONS APPEAR
LIGHT. DRY AND COLD CONDITIONS ARE FORECAST MONDAY NIGHT THROUGH
TUESDAY AS CANADIAN HIGH PRESSURE SETTLES ACROSS MONTANA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 641 AM CST WED FEB 11 2015
THE LATEST SATELLITE IMAGERY SHOWS MOSTLY CLEAR CONDITIONS THROUGH
CENTRAL NORTH DAKOTA...WHICH INCLUDES KMOT/KBIS/KJMS. EXPECT VFR
CIGS THROUGH MID MORNING...FOLLOWED BY MVFR CIGS FROM 15Z-21Z. THE
WESTERN TERMINALS OF KISN AND KDIK WILL REMAIN ON THE FRINGES OF
MVFR AND VFR THROUGH MID TO LATE AFTERNOON. VFR CIGS ARE FORECAST TO
RETURN TO ALL TERMINALS BETWEEN 21Z WEDS AND 00Z THURSDAY. CLOUDS
INCREASE WEST...AT KISN AND KDIK AFTER MIDNIGHT...BUT STILL REMAIN
IN VFR STRATUS UNTIL 12Z THURSDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON CST THURSDAY
FOR NDZ001>003-010>013-021>023-025-035>037-046>048-050-051.
WIND CHILL ADVISORY FROM 3 PM THIS AFTERNOON TO NOON CST
THURSDAY FOR NDZ004-005.
&&
$$
UPDATE...TM
SHORT TERM...KS
LONG TERM...TM
AVIATION...KS
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
545 AM CST WED FEB 11 2015
.AVIATION...
WIND SPEEDS EXPECTED TO INCREASE BY MID TO LATE MORNING AS TIGHTER
SURFACE PRESSURE PACKING MOVES IN. SOLUTIONS HAVE TRENDED A BIT
LESS CERTAIN WITH AN MVFR CLOUD DECK FOR KCDS TODAY...BUT THIS
STILL SEEMS LIKELY FOR KPVW AND KLBB THOUGH A BIT DELAYED. RAIN
CHANCES TOO UNCERTAIN AT EITHER KPVW OR KLBB...BETTER TO THE
WEST...FOR INCLUSION. CLOUDS SHOULD THIN TONIGHT. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 404 AM CST WED FEB 11 2015/
SHORT TERM...
NORTHERLY WIND SHIFT HAS PUSHED THROUGH ALREADY BUT STRONGER
PRESSURE GRADIENT STILL AWAITS WITH MAIN COLD AIR ADVECTION LATER
THIS MORNING INTO THE EARLY AFTERNOON. MOST RECENT RAP AND HRRR RUNS
SEEM TO SUPPORT WIND SPEEDS NEAR OR JUST SHY OF WIND ADVISORY
LEVELS. A WEAK UPPER LOW MEANWHILE EXPECTED TO PINCH OFF ACROSS THE
SOUTHERN ROCKIES LATER TODAY WHILE DROPPING SOUTHWARD. BEST LIFT AND
MOISTURE APPEAR TO REMAIN JUST TO OUR WEST...BUT PERHAPS ENOUGH LIFT
WITH MEAGER MOISTURE LAYERS TO SUPPORT LOW CHANCES OF LIGHT RAIN OR
SHOWERS MAINLY WESTERN AND CENTRAL ZONES AT LEAST THIS AFTERNOON AND
EARLY EVENING. LATEST SOLUTIONS HAVE TRIMMED BETTER PRECIPITATION A
BIT FURTHER WEST OF PREVIOUS FORECAST AND WE HAVE FOLLOWED THIS
TREND AS WELL. DRYING AND SUBSIDENT AIRMASS SHOULD GRADUALLY TAKE
BACK OVER OVERNIGHT. RECENT TEMPERATURE GUIDANCE REASONABLY SIMILAR
TO PREVIOUS WITH ONLY MINOR CHANGES. RMCQUEEN
LONG TERM...
DRY NORTHWEST FLOW WILL SET UP THURSDAY INTO THE WEEKEND BETWEEN
WEST COAST RIDGING EXTENDING INTO THE YUKON/NORTHWEST TERRITORIES
AND LOCKED IN CYCLONIC FLOW ACROSS EASTERN NORTH AMERICA. SURFACE
RIDGING WILL SLIDE EAST INTO THE MIDWEST THURSDAY AS LEE TROUGHING
TAKES FORM IN THE FRONT RANGE BEFORE EJECTING INTO THE PLAINS FRIDAY
BRINGING A NORTHERLY WIND SHIFT TO THE SOUTH PLAINS. ANY SEMBLANCE
OF COOLER AIR WILL REMAIN BOTTLED UP SEVERAL HUNDRED MILES TO THE
NORTHEAST...ALLOWING THE WARMING TREND TO CONTINUE INTO THE WEEKEND.
AFTER TEMPERATURES TOPPING OUT NEAR NORMAL IN THE 50S THURSDAY...A
STEADY RISE INTO THE 60S AND 70S WILL BE ON DECK FOR FRIDAY AND
SATURDAY RESPECTIVELY. A BACKDOOR FRONT WILL PUSH THROUGH THE PLAINS
SATURDAY AS YET ANOTHER LOBE OF ENERGY ROTATES AROUND A LOW ANCHORED
IN VICINITY OF HUDSON BAY...ARRIVING SOMETIME EARLY SUNDAY AND
LIKELY RESULTING IN A DECENT NORTHEAST TO SOUTHWEST TEMPERATURE
GRADIENT WITH HIGHS RANGING FROM THE UPPER 50S IN THE FAR SOUTHEAST
PANHANDLE TO NEAR 70 IN THE SOUTHWEST SOUTH PLAINS.
A SIGNIFICANT PATTERN CHANGE CONTINUES TO LOOM FOR EARLY NEXT WEEK
WITH BACKING UPPER FLOW DOWNSTREAM OF AN UPPER LOW...ORIGINATING
FROM A LOW OFF BAJA PHASING WITH THE RETROGRADE CUTOFF LOW
RESPONSIBLE FOR TODAY/S FRONT...AND SHORTWAVE TROUGH MIGRATING
SOUTHEASTWARD OUT OF WESTERN CANADA. MOISTURE ADVECTION LOOKS TO
HAVE LONG ENOUGH OF A RESIDENCE TIME FOR PRECIPITATION TO BECOME A
POSSIBILITY BY LATE MONDAY INTO TUESDAY AT THIS JUNCTURE. THIS LOOKS
TO BE WHEN NWP SOLUTIONS BEST CONVERGE ON UPPER SUPPORT COMBINING
WITH FRONTOGENETICAL FORCING FROM WHAT AT THIS POINT LOOKS TO BE A
STOUT FRONT...SERVING AS A REMINDER THAT FEBRUARY IS INDEED WINTER
IN THE NORTHERN HEMISPHERE. OVERALL TRENDS HAVE BEEN SHOWING THIS
PATTERN DEVELOPING WITH EASTERN PACIFIC RIDGING BECOMING HIGHLY
AMPLIFIED ENOUGH TO ALLOW FOR A SIGNIFICANT DUMP OF COLD AIR THROUGH
THE CENTRAL CONUS. AS FAR AS PRECIPITATION TYPE...A MIX OF RAIN AND
SNOW INITIALLY TRANSITIONING TO ALL SNOW SEEMS VALID GIVEN THIS
EXPECTED PUNCH OF CANADIAN AIR LASTING INTO MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 43 26 55 30 / 40 10 0 0
TULIA 47 28 54 30 / 20 10 0 0
PLAINVIEW 49 28 54 30 / 20 10 0 0
LEVELLAND 50 30 54 31 / 20 20 0 0
LUBBOCK 51 30 54 31 / 20 10 0 0
DENVER CITY 50 31 54 30 / 20 30 0 0
BROWNFIELD 50 31 54 31 / 20 30 0 0
CHILDRESS 56 30 53 32 / 10 10 0 0
SPUR 53 31 53 31 / 10 10 0 0
ASPERMONT 57 33 52 33 / 10 10 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/05
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1035 AM MST WED FEB 11 2015
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 246 AM MST WED FEB 11 2015
UPPER FLOW WILL BE NORTHWEST THROUGH FRIDAY NIGHT WITH A AMPLIFIED
RIDGE OVER THE WESTERN CONUS. SURFACE HIGH PRESSURE WILL MOVE INTO
THE CENTRAL PLAINS TODAY AND TONIGHT. A TROUGH WILL MOVE INTO
EASTERN COLORADO THURSDAY/THURSDAY NIGHT AS HIGH PRESSURE SHIFTS
EAST. HIGH PRESSURE WILL MOVE INTO THE REGION BEHIND THE EXITING
SURFACE TROUGH FRIDAY/FRIDAY NIGHT.
SUBSIDENCE WILL FOLLOW THE EXITING SHORTWAVE THIS MORNING AND
CONTINUE THROUGH TONIGHT. A WEAK SHORTWAVE IS NOTED IN THE FLOW ON
THURSDAY BUT MOISTURE IS WELL TO THE EAST OF THE FA SO THAT
PRECIPITATION SHOULD BE UNLIKELY. SUBSIDENCE FOLLOWS THE EXITING
SHORTWAVE THURSDAY NIGHT AND CONTINUES THROUGH FRIDAY NIGHT. AS A
RESULT, ALL PERIODS WILL BE DRY WITH NIL POPS.
NAM BOUNDARY LAYER RH INCREASES TO 90 PERCENT AS THE COLD FRONT
MOVES INTO THE FA THIS MORNING. THE HRRR INDICATES CEILINGS OF
AROUND 1000FT. THE LOWER CEILINGS WILL MOVE OUT OF THE SOUTHERN FA
BY 17Z ACCORDING TO THE HRRR.
850 TEMPERATURES INDICATE SEASONABLE TEMPERATURES TODAY IN THE MID
40S AND THEN WARMING UP TO THE LOWER 60S IN EASTERN COLORADO
THURSDAY WITH MID 50S IN NORTHWEST KANSAS. MAX TEMPERATURES FRIDAY
SHOULD RISE TO NEAR 60. MIN TEMPERATURES SHOULD COOL TO THE LOWER
TO MID 20S TONIGHT AND THEN MODERATE TO THE LOWER 30S THURSDAY AND
FRIDAY NIGHTS.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 246 AM MST WED FEB 11 2015
SATURDAY THROUGH TUESDAY WILL SEE TEMPERATURES RETURNING TO MORE
NORMAL VALUES AS A COOLER AIR MASS MOVES OVER THE AREA BEGINNING
SATURDAY...AS WELL AS A CHANCE FOR PRECIPITATION EARLY NEXT WEEK.
OVER THE WEEKEND THE UPPER LEVEL RIDGE THAT HAS BEEN SITUATED OVER
THE GREAT BASIN WILL BE PUSHED BACK WEST AS A STRONGER UPPER LEVEL
TROUGH MOVES SOUTHEAST OUT OF CANADA. THE TROUGH WILL DEEPEN AS IT
MOVES SOUTHEAST ACROSS THE CONUS. AS IT DOES SO THE UPPER LEVEL
FLOW WILL RESEMBLE MORE OF A SPLIT FLOW SETUP...PRIOR TO THE
TROUGH REACHING THE HIGH PLAINS. IF THIS PATTERN DOES DEVELOP
THERE WILL BE VERY LITTLE CHANCE FOR PRECIPITATION MONDAY NIGHT
DUE TO THE UPPER LEVEL FORCING GOING AROUND THE AREA. HOWEVER WILL
LEAVE IN THE CONSENSUS OF MINIMAL CHANCES FOR PRECIPITATION AS THE
TROUGH MOVES THROUGH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1026 AM MST WED FEB 11 2015
VFR EXPECTED AT BOTH KGLD AND KMCK THROUGH THE TAF PERIOD. A
REINFORCING SHOT OF COOLER AIR OVERNIGHT WILL SHIFT WINDS AROUND
TO NORTHEAST AND BE ACCOMPANIED BY SOME MID AND HIGH CLOUDS. SREF
SHOWING LOW PROBABILITIES FOR MVFR CEILINGS AT KMCK AROUND
SUNRISE...BUT CONFIDENCE IS LOW AND KEPT THEM VFR IN THE TAF.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...FS
LONG TERM...JTL
AVIATION...024
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1117 AM CST Wed Feb 11 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 325 AM CST WED FEB 11 2015
Next in a series of cold fronts making its way southward toward the
CWA at this hour. Increasing northerly winds and stratus are
expected Eastern Kansas through the morning hours. Strong shortwave
also noted over southern Colorado, streaming stratus to the east
over Western Kansas, however energy dropping into the back of this
system should drive this southward through the day today and leave
little impact over our area.
Cold air advection continues through the day today. This combined
with stratus early should hold high temperatures only in the 30s to
near 40 this afternoon, however northerly winds will leave it
feeling like highs in the 20s to low 30s. NAM is more aggressive
with keeping clouds over the area while HRRR and GFS/EC indicate
subsidence and clearing for at least a portion of the day today.
Evening hours bring a break in the winds and the clouds, however
secondary cold front advances southward across the area after
midnight and brings in even colder temperatures in the teens. Given
north winds of 15 to 20 mph, also anticipate wind chill values near
zero, and as low as -10 near in the far northeastern counties by
early Thursday.
.LONG TERM...(Thursday through Tuesday)
Issued at 325 AM CST WED FEB 11 2015
Northwest flow aloft keeps temperatures as the main challenge into
the weekend. Surface high comes in Thursday for decreasing winds,
but the cold air in place will keep temps about 10F colder than
today. Still appears temps may be rather steady or slowly rise late
Thursday night as warm air surges back east ahead of next strong
upper wave rotating around the persistent upper level trough in the
east. This continues to suggest a much warmer Friday than recent
days, but the weekend periods bring much colder temps again with
cold front coming through late Friday night into Saturday. Have a
rather high temperature spread across the area Saturday and timing
of best cold air advection varies so confidence on specifics is low.
Limited mixing in 850mb temps around -8 C brings an even colder
Sunday.
Final few periods of this forecast bring increasing precipitation
chances. There is fairly good operational and ensemble agreement in
the western upper ridge redeveloping off the coast for a more zonal
to even southwest flow taking shape early in the week. Resulting
deep isentropic lift should be able to saturate enough of the column
for precip chances as early as late Sunday night but with greater
chances Monday into Monday night. Precip type looking more
challenging than most normal long-range forecasts with questions on
depth of moisture to produce ice in the cloud and the potential for
an above-freezing layer to develop under still cold near-surface
conditions.
&&
.AVIATION...(For the 18Z TAFs through 18Z Thursday Afternoon)
Issued at 1115 AM CST WED FEB 11 2015
For the 18z TAFs, MVFR cigs will continue to scatter out this
morning with breezy northerly winds persisting through late
afternoon. While there will be a brief break in the wind gusts this
evening, expect winds to become gusty once again near KTOP/KFOE
early Thursday morning with another passing wave before diminishing
by late morning.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...67
LONG TERM...65
AVIATION...Johnson/ACH
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1237 PM EST WED FEB 11 2015
.SYNOPSIS...
A LATE DAY COLD FRONT WILL BEGIN THE TRANSITION TO FRIGID TEMPERATURES
WHICH WILL PERSIST INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAIN CHANGE TODAY WAS TO ADJUST TEMPS JUST A FEW DEGREES...UPWARD
IN THE FAR NORTHERN ZONES AND DOWNWARD IN THE REMAINING ZONES.
LINGERING CLOUDS HAVE SUPPRESSED MIXING SUFFICIENTLY TO THROW A
WRENCH IN THE TYPICAL DIURNAL HEATING CURVE. GIVEN THAT THE
NOCTURNAL INVERSION HAS MOSTLY MIXED OUT...IT WILL TAKE THE REST
OF THE AFTERNOON TO MIX OUT THE REMAINING FEW HUNDRED FEET TO
ACHIEVE UPPER 30S. PREVIOUS DISCUSSION FOLLOWS...
OVERALL...A SOFT DAY IS ANTICIPATED FOR THE UPPER OHIO REGION AS
A STRONG SHORTWAVE TROUGH...WITH AXIS OVER THE UPPER MISSISSIPPI
VALLEY THIS MORNING...PROGRESSES OVER THE GREAT LAKES. WARM
ADVECTION IN ADVANCE OF THAT SYSTEM SHOULD SUPPORT HIGHS NEAR THE
MID FEBRUARY AVERAGES DESPITE A CLOUD INCREASE WITH THE MID LEVEL
MOISTURE SURGE. THE TEMPERATURE FORECAST WAS TWEAKED USING THE
LATEST SREF...NAM...AND RAP GUIDANCE TRENDS...BUT CHANGES WERE
MINIMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
THE ACTUAL COLD FRONT PASSAGE IS NOT EXPECTED TO BE DRAMATIC AS
FAR AS PRECIPITATION IS CONCERNED WITH THE LOW CENTER PROJECTED
TOWARD NEW YORK AND A MID LEVEL DRY SLOT RAPIDLY ENCROACHING INTO
UPPER OHIO VALLEY AIRSPACE. HOWEVER...THURSDAY TEMPERATURES WILL
BE ON THE DECLINE...WITH SNOW SHOWER COVERAGE INCREASING UNDER A
FRIGID MID LEVEL THERMAL TROUGH.
THE STEEPENING LOW LEVEL LAPSE RATES AND A SHALLOW DENDRITIC
GROWTH ZONE WILL RESULT IN INCREASED CONVECTIVE SNOW SHOWER
ACCUMULATION POTENTIAL ON THURSDAY...ESPECIALLY IN THE USUAL
UPSLOPE AREAS OF THE RIDGES AND ZONES IN LEE OF THE LAKES. NOT
MUCH CHANGE WAS NEEDED FOR THE ONGOING 1-2 FORECAST WITH 2-4
INCHES ON THE RIDGES.
EASTWARD PROGRESS OF THE MAIN MID LEVEL COLD POOL...I.E. FALLING
INVERSION LEVELS WITH DRY ADVECTION SHOULD RAPIDLY LIMIT ADDITIONAL
ACCUMULATION POTENTIAL ON THURSDAY NIGHT.
THE COLD THURSDAY NIGHT AND FRIDAY TEMPERATURE FORECAST WAS NOT
DISPUTED MUCH BY INCOMING GUIDANCE AS A HIGH AMPLITUDE EASTERN
U.S. UPPER TROUGH AXIS IS DEVELOPED SLOWLY EASTWARD...HENCE
CHANGES WERE MINIMAL ALTHOUGH THE WIND WAS REDONE USING NAM AND
GFS GRIDS. WIND CHILL INDICES STILL ARE PROJECTED INTO THE
ADVISORY RANGE OF -10 TO -20C...SO A HAZARDOUS WEATHER OUTLOOK
MENTION WILL BE MAINTAINED WITH A MENTION OF SNOW ACCUMULATION IN
THE RIDGES...WHERE THE BETTER CHANCE FOR AN ADVISORY IS ON
THURSDAY.
NO REPRIEVE IS INDICATED THIS WEEKEND AS THE ECMWF AND GFS SOLUTIONS
ARE OF A STRONG SHORTWAVE ROTATING SOUTHWARD OUT OF THE HUDSON BAY
AREA. THAT SYSTEM AS MODELED WOULD RECARVE THE UPPER TROUGH OVER
THE EASTERN U.S. CURRENT PROJECTIONS ARE THAT THE MID LEVEL LOW
CENTER WILL REMAIN NORTH OF THE AREA...THUS KEEPING THE SNOW FAVORABLE
TROWAL...FRONTOGENESIS REGIONS AT BAY. NEVERTHELESS...A COLD COLUMN
WILL MAINTAIN FRIGID TEMPERATURES AND HIGH SNOW RATIO PARAMETERS.
PRECIPITATION PROBABILITIES WERE BUMPED UP ON SATURDAY IN ACCORDANCE
WITH THESE TRENDS AND GENERALLY ARE IN LINE WITH GFS GRIDS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS UPPER LOW MOVES EAST OF THE REGION...SNOW SHOWERS WILL WIND
DOWN SATURDAY NIGHT WITH SOME LAKE EFFECT CONTINUING INTO SUNDAY.
WITH THE SURFACE HIGH THEN BUILDING INTO THE REGION SUNDAY
NIGHT...WINDS WILL DIMINISH AND ALL SNOW WILL COME TO AN END.
SUNDAY AND SUNDAY NIGHT APPEARS TO BE THE COLDEST 24 HOUR PERIOD
OF THE WINTER SO FAR...WITH HIGHS IN THE SINGLE DIGITS AND LOWS
RANGING FROM 5 ABOVE TO 10 BELOW. WINDS MAY GO LIGHT WITH THE HIGH
PRESSURE CENTER OVERHEAD...WHICH COULD LIMIT JUST HOW LOW WIND
CHILL VALUES GO. LOW MOVES NORTHEAST FROM THE SOUTHERN PLAINS
MONDAY NIGHT INTO TUESDAY. EVEN WITH WARMER TEMPERATURES MOVING IN
BY MONDAY NIGHT...TEMPERATURES WILL REMAIN COLD ENOUGH THAT ALL
PRECIPITATION SHOULD FALL AS SNOW WITH THAT SYSTEM.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
SOME LOW CLOUDS CONTINUE TO PERSIST IN AREAS ALONG/NEAR THE
RIDGES...AT LOCATIONS LIKE MGW...IDI...AND DUJ. STILL EXPECT THESE
TO MOSTLY BREAK UP BY 20Z. OTHERWISE...VFR EXPECTED INTO THIS
EVENING WITH ONLY MID LEVEL CLOUDS. CIGS WILL DROP BEHIND A COLD
FRONT TONIGHT...WITH MVFR CONDITIONS FORECAST IN SCATTERED TO
NUMEROUS SHSN. SPOTTY IFR VSBYS ALSO POSSIBLE TONIGHT BUT
CONFIDENCE IN COVERAGE/TIMING OF THIS NOT ENOUGH TO INCLUDE YET.
BETTER CHANCE OF IFR AND EVENTUAL LIFR RESTRICTIONS COMES AFTER
12Z THURSDAY AS THE TRUE ARCTIC AIR ARRIVES. EXPECTING A PERIOD OF
SNOW SQUALLS TO ACCOMPANY THIS COLD SHOT...WITH LOCATIONS ALONG
THE RIDGES POTENTIALLY GETTING HIT HARD...ESPECIALLY IN MD/WV.
GUSTY NW WINDS WILL ACCOMPANY THIS ACTIVITY.
OUTLOOK.../THURSDAY THROUGH SUNDAY/...
RESTRICTIONS SHOULD DIMINISH THURSDAY NIGHT AS THE SYSTEM MOVES
EAST. PERIODIC RESTRICTIONS ARE THEN LIKELY FRIDAY NIGHT THROUGH
SUNDAY WITH A SERIES OF DISTURBANCES.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
1203 PM EST WED FEB 11 2015
.SYNOPSIS...
A LATE DAY COLD FRONT WILL BEGIN THE TRANSITION TO FRIGID TEMPERATURES
WHICH WILL PERSIST INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAIN CHANGE TODAY WAS TO ADJUST TEMPS JUST A FEW DEGREES...UPWARD
IN THE FAR NORTHERN ZONES AND DOWNWARD IN THE REMAINING ZONES.
LINGERING CLOUDS HAVE SUPPRESSED MIXING SUFFICIENTLY TO THROW A
WRENCH IN THE TYPICAL DIURNAL HEATING CURVE. GIVEN THAT THE
NOCTURNAL INVERSION HAS MOSTLY MIXED OUT...IT WILL TAKE THE REST
OF THE AFTERNOON TO MIX OUT THE REMAINING FEW HUNDRED FEET TO
ACHIEVE UPPER 30S. PREVIOUS DISCUSSION FOLLOWS...
OVERALL...A SOFT DAY IS ANTICIPATED FOR THE UPPER OHIO REGION AS
A STRONG SHORTWAVE TROUGH...WITH AXIS OVER THE UPPER MISSISSIPPI
VALLEY THIS MORNING...PROGRESSES OVER THE GREAT LAKES. WARM
ADVECTION IN ADVANCE OF THAT SYSTEM SHOULD SUPPORT HIGHS NEAR THE
MID FEBRUARY AVERAGES DESPITE A CLOUD INCREASE WITH THE MID LEVEL
MOISTURE SURGE. THE TEMPERATURE FORECAST WAS TWEAKED USING THE
LATEST SREF...NAM...AND RAP GUIDANCE TRENDS...BUT CHANGES WERE
MINIMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
THE ACTUAL COLD FRONT PASSAGE IS NOT EXPECTED TO BE DRAMATIC AS
FAR AS PRECIPITATION IS CONCERNED WITH THE LOW CENTER PROJECTED
TOWARD NEW YORK AND A MID LEVEL DRY SLOT RAPIDLY ENCROACHING INTO
UPPER OHIO VALLEY AIRSPACE. HOWEVER...THURSDAY TEMPERATURES WILL
BE ON THE DECLINE...WITH SNOW SHOWER COVERAGE INCREASING UNDER A
FRIGID MID LEVEL THERMAL TROUGH.
THE STEEPENING LOW LEVEL LAPSE RATES AND A SHALLOW DENDRITIC
GROWTH ZONE WILL RESULT IN INCREASED CONVECTIVE SNOW SHOWER
ACCUMULATION POTENTIAL ON THURSDAY...ESPECIALLY IN THE USUAL
UPSLOPE AREAS OF THE RIDGES AND ZONES IN LEE OF THE LAKES. NOT
MUCH CHANGE WAS NEEDED FOR THE ONGOING 1-2 FORECAST WITH 2-4
INCHES ON THE RIDGES.
EASTWARD PROGRESS OF THE MAIN MID LEVEL COLD POOL...I.E. FALLING
INVERSION LEVELS WITH DRY ADVECTION SHOULD RAPIDLY LIMIT ADDITIONAL
ACCUMULATION POTENTIAL ON THURSDAY NIGHT.
THE COLD THURSDAY NIGHT AND FRIDAY TEMPERATURE FORECAST WAS NOT
DISPUTED MUCH BY INCOMING GUIDANCE AS A HIGH AMPLITUDE EASTERN
U.S. UPPER TROUGH AXIS IS DEVELOPED SLOWLY EASTWARD...HENCE
CHANGES WERE MINIMAL ALTHOUGH THE WIND WAS REDONE USING NAM AND
GFS GRIDS. WIND CHILL INDICES STILL ARE PROJECTED INTO THE
ADVISORY RANGE OF -10 TO -20C...SO A HAZARDOUS WEATHER OUTLOOK
MENTION WILL BE MAINTAINED WITH A MENTION OF SNOW ACCUMULATION IN
THE RIDGES...WHERE THE BETTER CHANCE FOR AN ADVISORY IS ON
THURSDAY.
NO REPRIEVE IS INDICATED THIS WEEKEND AS THE ECMWF AND GFS SOLUTIONS
ARE OF A STRONG SHORTWAVE ROTATING SOUTHWARD OUT OF THE HUDSON BAY
AREA. THAT SYSTEM AS MODELED WOULD RECARVE THE UPPER TROUGH OVER
THE EASTERN U.S. CURRENT PROJECTIONS ARE THAT THE MID LEVEL LOW
CENTER WILL REMAIN NORTH OF THE AREA...THUS KEEPING THE SNOW FAVORABLE
TROWAL...FRONTOGENESIS REGIONS AT BAY. NEVERTHELESS...A COLD COLUMN
WILL MAINTAIN FRIGID TEMPERATURES AND HIGH SNOW RATIO PARAMETERS.
PRECIPITATION PROBABILITIES WERE BUMPED UP ON SATURDAY IN ACCORDANCE
WITH THESE TRENDS AND GENERALLY ARE IN LINE WITH GFS GRIDS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS UPPER LOW MOVES EAST OF THE REGION...SNOW SHOWERS WILL WIND
DOWN SATURDAY NIGHT WITH SOME LAKE EFFECT CONTINUING INTO SUNDAY.
WITH THE SURFACE HIGH THEN BUILDING INTO THE REGION SUNDAY
NIGHT...WINDS WILL DIMINISH AND ALL SNOW WILL COME TO AN END.
SUNDAY AND SUNDAY NIGHT APPEARS TO BE THE COLDEST 24 HOUR PERIOD
OF THE WINTER SO FAR...WITH HIGHS IN THE SINGLE DIGITS AND LOWS
RANGING FROM 5 ABOVE TO 10 BELOW. WINDS MAY GO LIGHT WITH THE HIGH
PRESSURE CENTER OVERHEAD...WHICH COULD LIMIT JUST HOW LOW WIND
CHILL VALUES GO. LOW MOVES NORTHEAST FROM THE SOUTHERN PLAINS
MONDAY NIGHT INTO TUESDAY. EVEN WITH WARMER TEMPERATURES MOVING IN
BY MONDAY NIGHT...TEMPERATURES WILL REMAIN COLD ENOUGH THAT ALL
PRECIPITATION SHOULD FALL AS SNOW WITH THAT SYSTEM.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
STRATUS CONTINUES TO PLAGUE FKL/DUJ/LBE...WITH FKL RIGHT ON THE
BORDER BETWEEN CLEAR SKIES AND NEAR LIFR CEILINGS. MVFR FOG AT ZZV
AND STRATUS AT FKL/DUJ/LBE SHOULD DIMINISH IN COVERAGE BY MID
MORNING...ALTHOUGH FKL/DUJ COULD POTENTIALLY STAY IN THE STRATUS
THROUGH THE TAF PERIOD. COLD FRONT PUSHES THROUGH THE REGION THIS
EVENING...BRINGING MVFR/IFR RESTRICTIONS AND A SHIFT IN THE
WINDS. STILL UNSURE OF HOW LOW VISIBILITIES WILL DROP WITH
SCATTERED SNOW SHOWERS...BUT HAVE AT LEAST BROUGHT A MENTION OF
SNOW INTO ALL TERMINALS. SNOW WILL NOT BECOME MORE WIDESPREAD
UNTIL THURSDAY...WITH IFR SNOW MENTIONED IN THE 30 HOUR PORTION OF
THE PITTSBURGH TAF.
OUTLOOK.../THURSDAY THROUGH SUNDAY/...
RESTRICTIONS SHOULD DIMINISH THURSDAY NIGHT AS THE SYSTEM MOVES
EAST. PERIODIC RESTRICTIONS ARE THEN LIKELY FRIDAY NIGHT THROUGH
SUNDAY WITH A SERIES OF DISTURBANCES.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
UPDATE...KRAMAR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
500 PM EST WED FEB 11 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 419 PM EST WED FEB 11 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A DEEPENING UPR
TROF OVER CENTRAL NAMERICA DOWNSTREAM OF A RDG OVER THE W. SEVERAL
SHRTWVS ARE EMBEDDED WITHIN THIS TROF...AND THEIR PRESENCE IS
RESPONSIBLE FOR 00Z-12Z H3 HGT FALLS IN EXCESS OF 200M AT YPL. THE
FIRST DISTURBANCE THAT BROUGHT THE LIGHT SN LAST NGT IS NOW MOVING E
INTO WRN QUEBEC. A SECOND SHRTWV THAT BROUGHT ANOTHER ROUND OF MORE
WDSPRD LIGHT SN THIS MRNG IS NOW MOVING TO THE E OF THE AREA...WITH
SUBSIDENCE IN ITS WAKE...WHICH LOWERED THE INVRN BASE TO H9 AT INL
AT 12Z...NOW RESTRICTING SN SHOWERS MAINLY TO AREAS NEAR LK SUP
IMPACTED BY THE COLD NW FLOW IN ITS WAKE. NW SFC WINDS HAVE BEEN
GUSTING AS HI AS 35 MPH...RESULTING IN SOME BLSN/REDUCED VSBYS.
LOOKING TO THE NW... AN EVEN STRONGER SHRTWV IS DIGGING SEWD THRU
MANITOBA AND TOWARD NW MN. 12Z H85-7 TEMPS WERE AS LO AS -30C/-28C
AT THE PAS MANITOBA WITHIN THE COLD SURGE ACCOMPANYING THIS SHRTWV.
THE 12Z RAOB AT THAT SITE ALSO SHOWED A FAIRLY MOIST LYR UP TO JUST
ABOVE H7.
MAIN FCST CONCERNS THRU THU ARE NUMEROUS AND RELATED TO GOING
HEADLINES/LES COVERAGE/AMOUNTS/WINDS AND BLSN AS WELL AS WIND CHILLS
THAT WL ACCOMPANY THIS INCOMING ARCTIC SURGE ASSOCIATED WITH
MANITOBA SHRTWV.
LATE TODAY/TNGT...SHRTWV NOW DIGGING THRU SRN MANITBOA IS FCST TO
DIVE TO NEAR THE MN ARROWHEAD BY 00Z AND INTO THE LOWER LKS BY 12Z
THU. THE ARRIVAL OF THE STRONGER DYNAMIC FORCING/DEEPER MSTR/CYC NW
VEERING N FLOW THIS EVNG ASSOCIATED WITH THIS DISTURBANCE WL BRING A
PERIOD OF LK ENHANCED SN IN AREAS FAVORED BY THESE WINDS AS THE
ACCOMPANYING CAA CAUSES H85 TEMPS TO BOTTOM OUT AS LO AS -25C TO
-27C BY 12Z THU. MIXING OF THE H925 WINDS AS HI AS 35-40 KTS WITH
THE VIGOROUS CAA WL CAUSE VERY GUSTY WINDS AND BLSN AS WELL...
ESPECIALLY IN OPEN AREAS NEAR LK SUP. STEADILY SHIFTING WINDS AND
THE ARRIVAL OF THE VERY COLD AIR THAT WL NEARLY ELIMINATE THE DGZ
AND GUSTY WINDS THAT WL FRAGMENT THE SN FLAKES AND FURTHER LOWER SN/
WATER RATIOS WL LIMIT LES AMOUNTS. THE HIER RES MODELS INDICATE THE
HEAVIEST SN WL FALL IN WRN ALGER COUNTY...WITH MORE PERSISTENT LLVL
CNVGC THERE ENHANCED BY THE PRESENCE OF A LARGE AMOUNT OF ICE BTWN
THE KEWEENAW AND MARQUETTE THAT WL ENHANCE A BIT OF A WNW LAND
BREEZE COMPONENT OFF THE W HALF OF UPR MI. THE STRONG LLVL WINDS WL
BLOW THESE SN SHOWERS FARTHER INLAND AND INTO DELTA COUNTY. THE ICE
COVER OVER FAR ERN LK SUP AND VEERING FLOW TO THE N THAT LIMITS
OVERWATER TRAJECTORY INTO LUCE COUNTY WL HAMPER SN ACCUMS OVER THE
FAR ERN CWA. THE COMBINATION OF THE STRONG WINDS/LO TEMPS FALLING
BLO ZERO WL CAUSE WIND CHILLS TO DIP AS LO AS -25F TO PERHAPS -30F.
LATE TNGT...VIGOROUS DNVA/DEEP LYR QVECTOR DVGC/STEADILY RISING H5
HGTS...FCST UP TO 100M BTWN 06Z-12Z OVER THE FAR W AT IWD...IN THE
WAKE OF THE DIGGING SHRTWV ARE FCST TO SHARPLY LOWER THE SUBSIDENCE
INVRN BASE TOWARD 2K FT AT IWD WL BRING A DIMINISHING TREND TO THE
LES. WEAKENING PRES GRADIENT/DIMINISHING LLVL WINDS FOLLOWING SHIFT
OF PRES CENTER TO THE E OF UPR MI WL CAUSE THE BLSN TO SUBSIDE A BIT
AS WELL.
THU...STEADILY RISING HGTS UNDER THE DNVA/LARGE SCALE QVECTOR DVGC
IN THE WAKE OF DEPARTING SHRTWV TOWARD THE MID ATLANTIC STATES AND
AHEAD OF SHRTWV RDG AXIS MOVING TOWARD THE UPR LKS THAT CAUSE A
CONTINUED LOWERING OF THE INVRN BASE TOWARD 2-3K FT EVEN OVER THE E
HALF LATE IN THE DAY WL BRING ABOUT A DIMINISHING TREND OF THE
LES...LATER OVER THE E. DIMINISHING/BACKING WINDS TOWARD THE NW WITH
APRCH OF SFC HI PRES RDG UNVER THE SUBSIDENCE WL CAUSE THE HEAVIER
LES OVER WRN ALGER COUNTY TO SHIFT TO THE E.
AS FOR THE HEADLINES...ALTHOUGH A GOOD DEAL OF ICE COVER IN THE LK
SUP NEARSHORE AREAS WL LIMIT SN TOTALS A BIT COMPARED TO WHAT WOULD
HAVE HAPPENED EARLY IN THE SEASON...GUSTY WINDS/BLSN EXACERBATED BY
THE NEARSHORE SN COVERED ICE WL BE SUFFICIENT TO WARRANT CONTINUED
HEADLINES. WILL CONTINUE THE WARNING FOR ALGER COUNTY GIVEN SUPPORT
FM THE HI RES MODELS FOR THE HEAVIEST QPF IN THE WESTERN PART OF
THAT COUNTY. ADDED WIND CHILL ADVYS FOR LUCE AND DICKINSON/IRON
COUNTIES WITH WIND CHILLS FALLING AS LO AS -28F IN THE PRESENCE OF
SUSTAINED N WIND NEAR 10 MPH.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 500 PM EST WED FEB 11 2015
THE REGION IS NOW AMIDST AN ACTIVE PATTERN THAT WILL CONTINUE
THROUGH THE PERIOD. THIS PATTERN IS SOMEWHAT REMINISCENT TO LAST
WINTER AS A BROAD TROUGH BUILDS ACROSS EASTERN NORTH AMERICA.
CONCERNS CONTINUE TO GROW FOR POOR CONDITIONS FRIDAY NIGHT AND
SATURDAY WITH THE ARRIVAL OF SOME OF THE COLDEST AIR OF THE SEASON.
STRONG WINDS WILL LEAD TO VERY LOW VISIBILITIES ALONG LAKE
SUPERIOR...WITH BLIZZARD CONDITIONS QUITE POSSIBLE ALONG LAKE
SUPERIOR TO START THE WEEKEND.
THURSDAY NIGHT...A BROAD TROUGH CENTERED NEAR EASTERN HUDSON BAY
WILL SLOWLY SHIFT NORTHEASTWARD AS AN ASSOCIATED SFC TROUGH TRACKS
ACROSS THE LOWER GREAT LAKES. A SUBTLE RIDGE WILL SHIFT ACROSS THE
CWA THURSDAY NIGHT. HOWEVER...WITH COLD AIR LINGERING AROUND AND
INVERSION HEIGHTS REMAINING AROUND 3KFT...SOME LES WILL CONTINUE
ACROSS THE EAST BEFORE WINDS BACK TO THE SW BY DAYBREAK FRIDAY.
FRIDAY THROUGH SATURDAY...A STRENGTHENING UPPER JET COMBINED WITH A
POTENT SHORTWAVE TROUGH DIGGING SE INTO NW ONTARIO WILL INDUCE A SFC
LOW NORTH OF LAKE SUPERIOR FRIDAY MORNING. WEAK ISENTROPIC LIFT
AHEAD OF THIS LOW WILL SPREAD LIGHT SNOW ACROSS MUCH OF THE CWA
DURING THE DAY FRIDAY...WITH ACCUMULATIONS GENERALLY AROUND AN INCH.
BY EARLY-AFTERNOON...THE COLD FRONT ASSOCIATED WITH THE SFC LOW WILL
BE NEARING THE WESTERN CWA. H8 TEMPS FALLING FROM -15 TO -30C OVER
12-18 HOURS WILL ALLOW FOR A RAPID ONSET OF LAKE EFFECT SNOW FOR THE
NW-WIND SNOW BELTS ACROSS THE WEST BY LATE FRIDAY AFTERNOON. THE
WIND WILL QUICKLY BECOME NORTHERLY FOR ALL OF UPPER MI SATURDAY
EVENING AS THE SFC LOW TRACKS INTO NW LAKE HURON/GEORGIAN BAY.
TEMPERATURES WILL FALL QUICKLY...WITH HIGHS FAILING TO RISE ABOVE
ZERO FOR MOST OF THE AREA ON SATURDAY. WITH BLUSTERLY
CONDITIONS...WIND CHILLS WILL BE -20 TO -30F LATE FRIDAY NIGHT
THROUGH SATURDAY NIGHT.
THERE IS LITTLE DOUBT THAT WINDS WILL BE QUITE STRONG /GUSTING OVER
40MPH ALONG LAKE SUPERIOR/ BEHIND THIS FRONT AS AN ARCTIC HIGH OF
APPROX 1050MB BUILDS SE OUT OF SASKATCHEWAN AND THE 1005MB LOW MOVES
TOWARD THE LOWER GREAT LAKES. HOWEVER...THE STRENGTH OF THE PRESSURE
GRADIENT WILL DEPEND HEAVILY ON HOW THE UPPER JET AND MID-LEVEL
TROUGH INTERACT AS THE LOW MOVES AWAY FROM THE AREA. THE BEST
FORCING ON THE LEFT-EXIT OF THE JET LOOKS TO BE SOMEWHAT REMOVED TO
THE SOUTH OF THE MAIN SHORTWAVE ENERGY. IF THESE FEATURES CAN COME
INTO BETTER ALIGNMENT TO PRODUCE A STRONGER LOW...BLIZZARD
CONDITIONS WOULD BE LIKELY ALONG MUCH OF LAKE SUPERIOR FRIDAY NIGHT
THROUGH SATURDAY. THE AFOREMENTIONED ISSUES ALSO PRODUCE A STRONG
ISALLOBARIC WIND COMPONENT THAT IS MORE PERPENDICULAR THAN PARALLEL
TO THE GRADIENT WIND...THUS PROVIDING ONLY MARGINAL ENHANCEMENT TO
THE OVERALL WINDS.
WITH THE VERY COLD...AND RATHER DRY...ARCTIC AIR...SNOWFLAKE
PRODUCTION WILL BE DIFFICULT. THE EXPECTATIONS IS FOR VERY SMALL LOW-
RATIO SNOWFLAKES BY LATE FRIDAY NIGHT. FOR THIS REASON...SNOW
AMOUNTS ARE NOT OF UTMOST CONCERN WITH THIS SYSTEM. THE COMBINATION
OF THE STRONG WINDS AND SMALL SNOWFLAKE SIZE WILL GREATLY REDUCE
VISIBILITY. WHITE-OUT CONDITIONS ARE EXPECTED AT TIMES ALONG LAKE
SUPERIOR...ESPECIALLY SATURDAY MORNING. THE ONE MAJOR WILD CARD WILL
BE THE EVOLUTION OF THE ICE PACK ON LAKE SUPERIOR. ICE MODEL
FORECASTS INDICATE THAT TONIGHTS WINDS WILL GREATLY COMPACT THE ICE
ALONG THE SOUTHERN SHORE OF LAKE SUPERIOR. THIS WOULD PROVIDE MORE
OPEN WATER FOR LES PRODUCTION FOR THE WEEKEND. ADDITIONALLY...THE
ICE SHELF OFF SHORE WILL BE YET ANOTHER SOURCE OF SNOW FOR THE WINDS
TO BLOW AROUND NEAR THE SHORELINES.
WHILE BLIZZARD CONDITIONS ARE APPEARING MORE LIKELY FOR MUCH OF THE
KEWEENAW AND AREAS FROM BIG BAY TO GRAND MARAIS ALONG LAKE SUPERIOR
FRIDAY NIGHT THROUGH SATURDAY...HAVE DECIDED TO HOLD OFF ON ANY
HEADLINES AT THIS TIME FOR TWO REASONS. FIRST...THE MESSAGE
PERTAINING TO ONGOING ADVISORIES AND HEADLINES HIGHLIGHTING TONIGHTS
WEATHER MAY GET MIXED WITH ANY WATCHES FOR FRI NIGHT AND SAT.
SECOND...FORECASTER CONCENSUS IS TO SEE WHAT HAPPENS TONIGHT IN
ORDER TO GET A SAMPLE OF WHAT FRIDAY NIGHT AND SAT MAY HOLD. IF
CONDITIONS TONIGHT BECOME QUITE POOR...CONFIDENCE WILL SIGNIFICANTLY
INCREASE FOR BLIZZARD CONDITIONS EARLY THIS WEEKEND. ANY HEADLINES
MAY NOT BE ISSUED UNTIL THURSDAY...AND COULD SKIP ANY WATCHES AND GO
STRAIGHT TO A WARNING IF NEED BE.
SATURDAY NIGHT AND SUNDAY...LAKE EFFECT SNOW SHOWERS WILL CONTINUE
FOR THE NORTH WIND SNOW BELTS AS A WEAK SECONDARY TROUGH TRACKS
ACROSS THE AREA IN THE EVENING. A MID-LEVEL/SFC RIDGE BUILDING IN
FROM THE NORTHERN PLAINS LATE SATURDAY NIGHT WILL INCREASE
CONVERGENCE ACROSS THE EASTERN LAKE. THIS MAY LEAD TO A CONTINUED
DOMINATE LES BAND BETWEEN MARQUETTE AND MUNISING AS INVERSION
HEIGHTS REMAIN AROUND 5KFT. THIS LES WILL QUICKLY SHIFT OFF SHORE
DURING THE DAY SUNDAY AS THE RIDGE WORKS ACROSS LAKE SUPERIOR.
MONDAY THROUGH WEDNESDAY...A BROAD TROUGH MOVING IN FROM SOUTH-
CENTRAL CANADA WILL BRING SMALL CHANCES OF SNOW FOR MONDAY. THIS
TROUGH WILL AMPLIFY MONDAY NIGHT AND CROSS UPPER MI TUESDAY INTO
TUESDAY NIGHT. THIS WILL BRING ANOTHER ROUND OF BREEZY CONDITIONS
AND INCREASED LES FOR THE NW-WIND SNOW BELTS. HOWEVER...CONDITIONS
ARE NET EXPECTED TO BE AS BAD AS EARLY THIS WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1224 PM EST WED FEB 11 2015
SUBSIDENCE IN THE WAKE OF A PASSING DISTURBANCE WILL RESULT IN
PREDOMINANT MVFR CONDITIONS AT CMX AND IWD THIS AFTN...BUT GUSTY NW
WINDS/BLSN AND A FEW HEAVIER SHSN RELATED TO SURGE OF COLD AIR WL
CAUSE AT LEAST TEMPO IFR CONDITIONS AT THESE LOCATIONS. SINCE THE NW
WINDS DOWNSLOPE INTO SAW...THAT AIRPORT SHOULD SEE VFR TO AT TIMES
MVFR CONDITIONS. AS ANOTHER STRONGER DISTURBANCE/DYNAMIC FORCING AND
DEEPER MSTR ARRIVE TNGT ALONG WITH EVEN STRONGER NNW WINDS THAT WL
CAUSE CONSIDERABLE BLSN...IFR TO LIFR CONDITIONS WL PREVAIL AT ALL 3
TAF SITES. WITH STRONG SUBSIDENCE/DIMINISHING WINDS AND BLSN
FOLLOWING THE PASSAGE OF THIS DISTURBANCE...CONDITIONS WL SLOWLY
IMPROVE TO MVFR LATE TNGT/THU MRNG.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EST WED FEB 11 2015
ONGOING GALES/HEAVY FREEZING SPRAY WILL DIMINISH W-E LATE TONIGHT
AND THU WITH THE APPROACH OF A HI PRES RIDGE/WEAKER PRES GRADIENT
AND DIMINISHING WINDS/WAVES. ANOTHER ROUND OF GALES/HEAVY FREEZING
SPRAY ASSOCIATED WITH ANOTHER ARCTIC AIR INVASION WILL DEVELOP FRI
NIGHT AND PERSIST THRU SAT. NOT OUT OF THE QUESTION THERE COULD BE
SOME STORM FORCE GUSTS ON SAT...ESPECIALLY OVER THE E HALF.
LOW PRESSURE NEAR GEORGIAN BAY WILL SLIDE ACROSS NEW ENGLAND THROUGH
THURSDAY AND DEEPEN. HIGH PRESSURE OVER SASKATCHEWAN WILL THEN
SETTLE OVER THE MID MISSISSIPPI RIVER VALLEY BY THURSDAY AFTERNOON
WITH A RIDGE EXTENDING NORTHWARD ACROSS THE UPPER GREAT LAKES.
EXPECT THE RIDGE TO REACH THE LOWER GREAT LAKES ON FRIDAY AS LOW
PRESSURE MOVES FROM NORTHERN ONTARIO TO LAKE SUPERIOR. THE LOW WILL
DEEPEN AS IT REACHES THE LOWER GREAT LAKES ON SATURDAY AND JUST OFF
THE NEW ENGLAND COAST ON SUNDAY. HIGH PRESSURE BUILDING FROM CENTRAL
CANADA INTO THE NORTHERN PLAINS ON SATURDAY WILL CROSS THE GREAT
LAKES THROUGH MONDAY AS A LOW PRESSURE TROUGH REACHES THE NORTHERN
PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 10 AM EST /9 AM CST/ THURSDAY FOR
MIZ001>004-009-084.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THURSDAY FOR MIZ013-085.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST THURSDAY
FOR MIZ010-011.
WINTER WEATHER ADVISORY UNTIL 4 PM EST THURSDAY FOR MIZ005.
WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR MIZ006.
WIND CHILL ADVISORY FROM 4 AM TO 1 PM EST THURSDAY FOR MIZ007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THURSDAY FOR LSZ267.
GALE WARNING UNTIL 1 PM EST THURSDAY FOR LSZ265-267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST THURSDAY FOR LSZ266.
GALE WARNING UNTIL 4 PM EST THURSDAY FOR LSZ266.
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THURSDAY FOR LSZ264.
GALE WARNING UNTIL 10 AM EST THURSDAY FOR LSZ264.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THURSDAY FOR LSZ263.
GALE WARNING UNTIL 7 AM EST THURSDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TK
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
424 PM EST WED FEB 11 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 419 PM EST WED FEB 11 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A DEEPENING UPR
TROF OVER CENTRAL NAMERICA DOWNSTREAM OF A RDG OVER THE W. SEVERAL
SHRTWVS ARE EMBEDDED WITHIN THIS TROF...AND THEIR PRESENCE IS
RESPONSIBLE FOR 00Z-12Z H3 HGT FALLS IN EXCESS OF 200M AT YPL. THE
FIRST DISTURBANCE THAT BROUGHT THE LIGHT SN LAST NGT IS NOW MOVING E
INTO WRN QUEBEC. A SECOND SHRTWV THAT BROUGHT ANOTHER ROUND OF MORE
WDSPRD LIGHT SN THIS MRNG IS NOW MOVING TO THE E OF THE AREA...WITH
SUBSIDENCE IN ITS WAKE...WHICH LOWERED THE INVRN BASE TO H9 AT INL
AT 12Z...NOW RESTRICTING SN SHOWERS MAINLY TO AREAS NEAR LK SUP
IMPACTED BY THE COLD NW FLOW IN ITS WAKE. NW SFC WINDS HAVE BEEN
GUSTING AS HI AS 35 MPH...RESULTING IN SOME BLSN/REDUCED VSBYS.
LOOKING TO THE NW... AN EVEN STRONGER SHRTWV IS DIGGING SEWD THRU
MANITOBA AND TOWARD NW MN. 12Z H85-7 TEMPS WERE AS LO AS -30C/-28C
AT THE PAS MANITOBA WITHIN THE COLD SURGE ACCOMPANYING THIS SHRTWV.
THE 12Z RAOB AT THAT SITE ALSO SHOWED A FAIRLY MOIST LYR UP TO JUST
ABOVE H7.
MAIN FCST CONCERNS THRU THU ARE NUMEROUS AND RELATED TO GOING
HEADLINES/LES COVERAGE/AMOUNTS/WINDS AND BLSN AS WELL AS WIND CHILLS
THAT WL ACCOMPANY THIS INCOMING ARCTIC SURGE ASSOCIATED WITH
MANITOBA SHRTWV.
LATE TODAY/TNGT...SHRTWV NOW DIGGING THRU SRN MANITBOA IS FCST TO
DIVE TO NEAR THE MN ARROWHEAD BY 00Z AND INTO THE LOWER LKS BY 12Z
THU. THE ARRIVAL OF THE STRONGER DYNAMIC FORCING/DEEPER MSTR/CYC NW
VEERING N FLOW THIS EVNG ASSOCIATED WITH THIS DISTURBANCE WL BRING A
PERIOD OF LK ENHANCED SN IN AREAS FAVORED BY THESE WINDS AS THE
ACCOMPANYING CAA CAUSES H85 TEMPS TO BOTTOM OUT AS LO AS -25C TO
-27C BY 12Z THU. MIXING OF THE H925 WINDS AS HI AS 35-40 KTS WITH
THE VIGOROUS CAA WL CAUSE VERY GUSTY WINDS AND BLSN AS WELL...
ESPECIALLY IN OPEN AREAS NEAR LK SUP. STEADILY SHIFTING WINDS AND
THE ARRIVAL OF THE VERY COLD AIR THAT WL NEARLY ELIMINATE THE DGZ
AND GUSTY WINDS THAT WL FRAGMENT THE SN FLAKES AND FURTHER LOWER SN/
WATER RATIOS WL LIMIT LES AMOUNTS. THE HIER RES MODELS INDICATE THE
HEAVIEST SN WL FALL IN WRN ALGER COUNTY...WITH MORE PERSISTENT LLVL
CNVGC THERE ENHANCED BY THE PRESENCE OF A LARGE AMOUNT OF ICE BTWN
THE KEWEENAW AND MARQUETTE THAT WL ENHANCE A BIT OF A WNW LAND
BREEZE COMPONENT OFF THE W HALF OF UPR MI. THE STRONG LLVL WINDS WL
BLOW THESE SN SHOWERS FARTHER INLAND AND INTO DELTA COUNTY. THE ICE
COVER OVER FAR ERN LK SUP AND VEERING FLOW TO THE N THAT LIMITS
OVERWATER TRAJECTORY INTO LUCE COUNTY WL HAMPER SN ACCUMS OVER THE
FAR ERN CWA. THE COMBINATION OF THE STRONG WINDS/LO TEMPS FALLING
BLO ZERO WL CAUSE WIND CHILLS TO DIP AS LO AS -25F TO PERHAPS -30F.
LATE TNGT...VIGOROUS DNVA/DEEP LYR QVECTOR DVGC/STEADILY RISING H5
HGTS...FCST UP TO 100M BTWN 06Z-12Z OVER THE FAR W AT IWD...IN THE
WAKE OF THE DIGGING SHRTWV ARE FCST TO SHARPLY LOWER THE SUBSIDENCE
INVRN BASE TOWARD 2K FT AT IWD WL BRING A DIMINISHING TREND TO THE
LES. WEAKENING PRES GRADIENT/DIMINISHING LLVL WINDS FOLLOWING SHIFT
OF PRES CENTER TO THE E OF UPR MI WL CAUSE THE BLSN TO SUBSIDE A BIT
AS WELL.
THU...STEADILY RISING HGTS UNDER THE DNVA/LARGE SCALE QVECTOR DVGC
IN THE WAKE OF DEPARTING SHRTWV TOWARD THE MID ATLANTIC STATES AND
AHEAD OF SHRTWV RDG AXIS MOVING TOWARD THE UPR LKS THAT CAUSE A
CONTINUED LOWERING OF THE INVRN BASE TOWARD 2-3K FT EVEN OVER THE E
HALF LATE IN THE DAY WL BRING ABOUT A DIMINISHING TREND OF THE
LES...LATER OVER THE E. DIMINISHING/BACKING WINDS TOWARD THE NW WITH
APRCH OF SFC HI PRES RDG UNVER THE SUBSIDENCE WL CAUSE THE HEAVIER
LES OVER WRN ALGER COUNTY TO SHIFT TO THE E.
AS FOR THE HEADLINES...ALTHOUGH A GOOD DEAL OF ICE COVER IN THE LK
SUP NEARSHORE AREAS WL LIMIT SN TOTALS A BIT COMPARED TO WHAT WOULD
HAVE HAPPENED EARLY IN THE SEASON...GUSTY WINDS/BLSN EXACERBATED BY
THE NEARSHORE SN COVERED ICE WL BE SUFFICIENT TO WARRANT CONTINUED
HEADLINES. WILL CONTINUE THE WARNING FOR ALGER COUNTY GIVEN SUPPORT
FM THE HI RES MODELS FOR THE HEAVIEST QPF IN THE WESTERN PART OF
THAT COUNTY. ADDED WIND CHILL ADVYS FOR LUCE AND DICKINSON/IRON
COUNTIES WITH WIND CHILLS FALLING AS LO AS -28F IN THE PRESENCE OF
SUSTAINED N WIND NEAR 10 MPH.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 419 AM EST WED FEB 11 2015
NAM SHOWS A DEEP 500 MB TROUGH OVER THE GREAT LAKES REGION 12Z THU
WITH A 500 MB RIDGE ON THE WEST COAST. PATTERN CHANGES LITTLE FOR
12Z FRI. A CLOSED 500 MB LOW HEADS SOUTH OUT OF HUDSON BAY FRI NIGHT
AND DIGS A DEEP TROUGH INTO THE UPPER GREAT LAKES 12Z SAT. AN
ALBERTA CLIPPER SYSTEM MOVES THROUGH THE AREA LATER FRI AFTERNOON
AND EVENING AND THE NAM HAS SOME 850-500 MB Q-VECTOR CONVERGENCE AND
DEEPER MOISTURE MOVE THROUGH THE CWA FRI BEFORE MOVING OUT FRI
NIGHT.
DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST AS PREVIOUS
FORECAST SEEMED TO HAVE THINGS WELL IN HAND. LAKE EFFECT SNOW
CONTINUES INTO THU WITH WINDS DECREASING DURING THE MORNING. WILL
CONTINUE WITH THE ADVISORIES INTO THU FOR THE SNOW AND BLOWING SNOW.
CLIPPER SYSTEM FOR FRI HAS WINDS INCREASING FRI NIGHT AND SNOW
AMOUNTS DO NOT LOOK REAL IMPRESSIVE...BUT WILL GET SOME BLOWING AND
DRIFTING OF SNOW AGAIN FRI NIGHT INTO SAT.
IN THE EXTENDED...GFS AND ECMWF SHOW A CLOSED 500 MB LOW OVER THE
UPPER GREAT LAKES 12Z SAT WITH COLD AIR MOVING ACROSS THE AREA. 850
MB TEMPERATURES ACROSS LAKE SUPERIOR ARE FROM -25C TO -30C AT THAT
TIME. THIS 500 MB TROUGH MOVES TO THE EASTERN U.S. 12Z SUN WITH SFC
HIGH PRESSURE OVER THE AREA. A COLD FRONT THEN MOVES INTO THE UPPER
GREAT LAKES 12Z MON WITH 850 MB TEMPERATURES AROUND -18C. COOLER AIR
IS AGAIN POISED TO MOVE INTO THE AREA ON TUE. TEMPERATURES WILL
REMAIN WELL BELOW NORMAL THIS FORECAST PERIOD WITH SOME LAKE EFFECT
SNOW BEING THE PREVALENT PCPN TYPE. AN ALBERTA CLIPPER SYSTEM HAS
ALREADY MOVED THROUGH THE AREA ON SAT. WILL HAVE TO CONTEND WITH
WIND CHILL WARNINGS AND ADVISORIES FOR SATURDAY AND WILL MENTION IN
THE HWO FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1224 PM EST WED FEB 11 2015
SUBSIDENCE IN THE WAKE OF A PASSING DISTURBANCE WILL RESULT IN
PREDOMINANT MVFR CONDITIONS AT CMX AND IWD THIS AFTN...BUT GUSTY NW
WINDS/BLSN AND A FEW HEAVIER SHSN RELATED TO SURGE OF COLD AIR WL
CAUSE AT LEAST TEMPO IFR CONDITIONS AT THESE LOCATIONS. SINCE THE NW
WINDS DOWNSLOPE INTO SAW...THAT AIRPORT SHOULD SEE VFR TO AT TIMES
MVFR CONDITIONS. AS ANOTHER STRONGER DISTURBANCE/DYNAMIC FORCING AND
DEEPER MSTR ARRIVE TNGT ALONG WITH EVEN STRONGER NNW WINDS THAT WL
CAUSE CONSIDERABLE BLSN...IFR TO LIFR CONDITIONS WL PREVAIL AT ALL 3
TAF SITES. WITH STRONG SUBSIDENCE/DIMINISHING WINDS AND BLSN
FOLLOWING THE PASSAGE OF THIS DISTURBANCE...CONDITIONS WL SLOWLY
IMPROVE TO MVFR LATE TNGT/THU MRNG.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EST WED FEB 11 2015
ONGOING GALES/HEAVY FREEZING SPRAY WILL DIMINISH W-E LATE TONIGHT
AND THU WITH THE APPROACH OF A HI PRES RIDGE/WEAKER PRES GRADIENT
AND DIMINISHING WINDS/WAVES. ANOTHER ROUND OF GALES/HEAVY FREEZING
SPRAY ASSOCIATED WITH ANOTHER ARCTIC AIR INVASION WILL DEVELOP FRI
NIGHT AND PERSIST THRU SAT. NOT OUT OF THE QUESTION THERE COULD BE
SOME STORM FORCE GUSTS ON SAT...ESPECIALLY OVER THE E HALF.
LOW PRESSURE NEAR GEORGIAN BAY WILL SLIDE ACROSS NEW ENGLAND THROUGH
THURSDAY AND DEEPEN. HIGH PRESSURE OVER SASKATCHEWAN WILL THEN
SETTLE OVER THE MID MISSISSIPPI RIVER VALLEY BY THURSDAY AFTERNOON
WITH A RIDGE EXTENDING NORTHWARD ACROSS THE UPPER GREAT LAKES.
EXPECT THE RIDGE TO REACH THE LOWER GREAT LAKES ON FRIDAY AS LOW
PRESSURE MOVES FROM NORTHERN ONTARIO TO LAKE SUPERIOR. THE LOW WILL
DEEPEN AS IT REACHES THE LOWER GREAT LAKES ON SATURDAY AND JUST OFF
THE NEW ENGLAND COAST ON SUNDAY. HIGH PRESSURE BUILDING FROM CENTRAL
CANADA INTO THE NORTHERN PLAINS ON SATURDAY WILL CROSS THE GREAT
LAKES THROUGH MONDAY AS A LOW PRESSURE TROUGH REACHES THE NORTHERN
PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 10 AM EST /9 AM CST/ THURSDAY FOR
MIZ001>004-009-084.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THURSDAY FOR MIZ013-085.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST THURSDAY
FOR MIZ010-011.
WINTER WEATHER ADVISORY UNTIL 4 PM EST THURSDAY FOR MIZ005.
WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR MIZ006.
WIND CHILL ADVISORY FROM 4 AM TO 1 PM EST THURSDAY FOR MIZ007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THURSDAY FOR LSZ267.
GALE WARNING UNTIL 1 PM EST THURSDAY FOR LSZ265-267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST THURSDAY FOR LSZ266.
GALE WARNING UNTIL 4 PM EST THURSDAY FOR LSZ266.
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THURSDAY FOR LSZ264.
GALE WARNING UNTIL 10 AM EST THURSDAY FOR LSZ264.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THURSDAY FOR LSZ263.
GALE WARNING UNTIL 7 AM EST THURSDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...07
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1205 PM CST WED FEB 11 2015
.UPDATE...
ISSUED AT 1205 PM CST WED FEB 11 2015
UPDATE TO EXPAND THE FLURRY MENTION TO NEARLY ALL OF WESTERN
AND CENTRAL NORTH DAKOTA THROUGH THE AFTERNOON. OTHERWISE...THE
FORECAST REMAINS ON TRACK AND BLENDED TO OBSERVED TRENDS THROUGH
18 UTC.
UPDATE ISSUED AT 951 AM CST WED FEB 11 2015
OTHER THAN TO ADD A SCATTERED FLURRY MENTION UNDER THE STRATUS
THIS MORNING PER SURFACE OBSERVATIONS...THE ONGOING FORECAST IS ON
TRACK FOR TODAY AND TONIGHT. TEMPERATURES WILL SLOWLY FALL FROM
MORNING HIGHS THE REMAINDER OF THE DAY AS COLD HIGH PRESSURE
PROPAGATES INTO THE DAKOTAS.
UPDATE ISSUED AT 641 AM CST WED FEB 11 2015
NO MAJOR CHANGES WERE MADE TO THE ONGOING FORECAST. THE CURRENT
WIND CHILL HEADLINES LOOK GOOD FOR TONIGHT INTO THURSDAY MORNING.
ONLY MADE MINOR ADJUSTMENTS TO THE HOURLY SENSIBLE WEATHER GRIDS.
THE UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 305 AM CST WED FEB 11 2015
THE ISSUANCE OF A WIND CHILL ADVISORY IS THE MAIN HIGHLIGHT IN THE
SHORT TERM PERIOD.
A 1050MB SURFACE HIGH PRESSURE CURRENTLY OVER EAST CENTRAL ALBERTA
WILL SLIDE SOUTHEAST TO NEAR REGINA BY 00Z THURSDAY...NEAR HARVEY
AT 06Z THURSDAY...AND INTO CASSELTON BY 12Z THURSDAY. EXPECT A
MOSTLY CLEAR SKY TO DEVELOP AS THE HIGH APPROACHES THIS AFTERNOON
AND TONIGHT. SUB ZERO LOW TEMPERATURES AND WINDS TO 10 MPH WILL
RESULT IN WIND CHILL TEMPERATURES TO 35 BELOW ZERO. A WIND CHILL
ADVISORY HAS BEEN HOISTED TO REFLECT THIS. THE TURTLE MOUNTAINS
WILL BE THE FIRST AREA TO DROP TO AROUND 25 BELOW BY MID AFTERNOON
TODAY AND THUS HAVE DIVIDED THE ADVISORY OUT INTO TWO AREAS. THE
TURTLE MOUNTAINS WILL BE VALID FROM 21Z WEDNESDAY THROUGH 18Z
THURSDAY...AND REMAINING LOCALES ALONG AND EAST OF THE MISSOURI
RIVER WILL HAVE A VALID TIME OF 00Z THURSDAY THROUGH 18Z THURSDAY.
THE LATEST WATER VAPOR IMAGERY SHOWS A NORTHWEST FLOW INTO NORTH
DAKOTA WITH ARCTIC AIR DESCENDING SOUTH FROM ALBERTA/SASKATCHEWAN.
SUCCESSIVE BUT WEAK SHORTWAVES WITH MOSTLY CHANNELED VORTICITY
POSE A SMALL THREAT FOR LIGHT SNOW IN SOUTHWEST NORTH DAKOTA
TODAY. HIGH RESOLUTION HRRR AND RAP13 INDICATE THIS AND HAVE
MAINTAINED THIS FEATURE FROM PREVIOUS FORECASTS. REGIONAL RADAR
ALREADY PICKING UP ON WEAK REFLECTIVITY`S EMERGING OVER NORTH
CENTRAL MONTANA. THE WINDOW OF OPPORTUNITY FOR LIGHT SNOW IS
ROUGHLY FROM 14Z-20Z TODAY. ELSEWHERE THE FOG/STRATUS LOOP SHOWS A
MOSTLY CLEAR SKY ACROSS THE NORTH CENTRAL WHICH IS WORKING TOWARD
THE SOUTH CENTRAL AT THIS TIME. STILL POCKETS OF STRATUS UPSTREAM.
BUFKIT SOUNDINGS THROUGHOUT THE UPCOMING MORNING MAINTAIN A MOIST
BOUNDARY LAYER...AND ONCE MIXING DEVELOPS BY MID MORNING...EXPECT
A PARTLY TO MOSTLY CLOUDY SKY TO ENSUE FOR A FEW HOURS. CONTINUED
MIXING INTO THE AFTERNOON WILL EVENTUALLY LEAD TO LESS CLOUDS AS
SUBSIDENCE AND DRIER AIR ALOFT GETS ENTRAINED AND LEADS TO
CLEARING CONDITIONS. HENCE WHATEVER CLOUDS TO DEVELOP EARLY ON
TODAY WILL DECREASE DURING THE MID TO LATE AFTERNOON. WARM AIR
ADVECTION DEVELOPS WEST OF THE MISSOURI RIVER WEDNESDAY NIGHT
LEADING TO RISING MOTION AND INCREASING CLOUDS IN THE WEST. THUS
TEMPERATURES NOT QUITE AS COLD WITH MINIMUM TEMPERATURES REMAINING
IN THE SINGLE DIGITS ABOVE ZERO WEST. OVERNIGHT LOWS ALONG AND
EAST OF THE MISSOURI RIVER WILL RANGE FROM 10 TO 20 BELOW
ZERO...AND AS MENTIONED ABOVE WIND CHILL TEMPERATURES TO 35 BELOW
ZERO.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 305 AM CST WED FEB 11 2015
THE MEDIUM RANGE MODELS CAUGHT UP WITH THE ECMWF AND ARE NOW
FORECASTING SNOW DEVELOPING AHEAD OF A WARM FRONT OVER WESTERN AND
CENTRAL NORTH DAKOTA THURSDAY. INCREASED SNOW CHANCES MAINLY
THURSDAY AFTERNOON AS A RESULT. NEW SNOW ACCUMULATIONS SHOULD
REMAIN LESS THAN AN INCH.
A DRY COLD FRONTAL PASSAGE IS THEN PROGGED FRIDAY. COLD CANADIAN
AIR IS EXPECTED TO FILTER INTO THE REGION AGAIN FRIDAY NIGHT INTO
SATURDAY. WIND CHILL HEADLINES MAY BE NEEDED EAST OF THE MISSOURI
RIVER FRIDAY NIGHT.
THE MEDIUM RANGE MODELS ARE COMING INTO BETTER AGREEMENT
FORECASTING A SHORTWAVE AND ITS ATTENDANT FRONT DIVING ACROSS
WESTERN AND CENTRAL NORTH DAKOTA LATE SATURDAY AFTERNOON THROUGH
SUNDAY. INCREASED THE CHANCES FOR SNOW GIVEN THE HIGHER CONFIDENCE
WITH THE LATEST MODEL RUNS. SNOW ACCUMULATIONS LOOK TO BE MORE
THAN PREVIOUSLY FORECAST AS WELL. WIDESPREAD AMOUNTS BETWEEN ONE
AND THREE INCHES LOOK POSSIBLE.
SNOW CHANCES WILL LINGER MONDAY AS A COLD FRONT IS PROGGED TO
PUSH FROM NORTH TO SOUTH. HOWEVER...NEW ACCUMULATIONS APPEAR
LIGHT. DRY AND COLD CONDITIONS ARE FORECAST MONDAY NIGHT THROUGH
TUESDAY AS CANADIAN HIGH PRESSURE SETTLES ACROSS MONTANA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1205 PM CST WED FEB 11 2015
WIDESPREAD VFR TO MVFR STRATUS WITH SCATTERED LIGHT SNOW SHOWERS
WILL DECREASE FROM NORTH TO SOUTH THROUGH THE AFTERNOON AS SURFACE
HIGH PRESSURE BUILDS INTO THE AREA. BRIEF IFR CONDITIONS IN THE
HEAVIER SNOW SHOWERS ARE POSSIBLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON CST THURSDAY
FOR NDZ001>003-010>013-021>023-025-035>037-046>048-050-051.
WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR NDZ004-005.
&&
$$
UPDATE...AYD
SHORT TERM...KS
LONG TERM...TM
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS TULSA OK
1125 AM CST WED FEB 11 2015
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
BAND OF STRATUS WITH MVFR CIGS WILL IMPACT THE NORTHEAST OK
TAF SITES THIS AFTERNOON...AND MAY MOVE INTO NW AR AS WELL.
THE BAND IS RATHER NARROW...SO EXPECT IMPROVEMENT FOR MOST
AREAS LATER THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 1054 AM CST WED FEB 11 2015/
..UPDATE...
DISCUSSION...
LEADING EDGE OF GUSTY N WINDS AND STRENGTHENING
LOW-LEVEL COLD AIR ADVECTION HAS WORKED TO NEAR
I-40...WITH RAGGED STRATUS DECK LAGGING BEHIND.
WILL SEE MINIMAL WARMING THE REMAINDER OF THE
DAY ACROSS NE OK...AND HAVE NUDGED UP HIGH TEMPS
A BIT ACROSS FAR SE OK PER LATEST HRRR OUTPUT.
SEEING A FEW RADAR ECHOES ACROSS SRN OK...SO A FEW
SPRINKLES/LIGHT SHOWERS NOT OUT OF THE QUESTION
THIS AFTERNOON.
UPDATED PRODUCTS WILL BE OUT SHORTLY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 51 24 41 27 / 10 0 0 0
FSM 60 29 44 26 / 10 0 0 0
MLC 58 29 44 26 / 20 10 0 0
BVO 46 18 38 19 / 10 0 0 0
FYV 53 22 38 18 / 10 0 0 0
BYV 50 20 36 19 / 10 0 0 0
MKO 55 24 42 24 / 10 0 0 0
MIO 46 19 35 24 / 10 0 0 0
F10 54 26 43 25 / 10 0 0 0
HHW 63 33 49 26 / 20 10 0 0
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...18
AREA FORECAST DISCUSSION
NWS TULSA OK
1054 AM CST WED FEB 11 2015
...UPDATE...
.DISCUSSION...
LEADING EDGE OF GUSTY N WINDS AND STRENGTHENING
LOW-LEVEL COLD AIR ADVECTION HAS WORKED TO NEAR
I-40...WITH RAGGED STRATUS DECK LAGGING BEHIND.
WILL SEE MINIMAL WARMING THE REMAINDER OF THE
DAY ACROSS NE OK...AND HAVE NUDGED UP HIGH TEMPS
A BIT ACROSS FAR SE OK PER LATEST HRRR OUTPUT.
SEEING A FEW RADAR ECHOES ACROSS SRN OK...SO A FEW
SPRINKLES/LIGHT SHOWERS NOT OUT OF THE QUESTION
THIS AFTERNOON.
UPDATED PRODUCTS WILL BE OUT SHORTLY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 51 24 41 27 / 10 0 0 0
FSM 60 29 44 26 / 10 0 0 0
MLC 58 29 44 26 / 20 10 0 0
BVO 46 18 38 19 / 10 0 0 0
FYV 53 22 38 18 / 10 0 0 0
BYV 50 20 36 19 / 10 0 0 0
MKO 55 24 42 24 / 10 0 0 0
MIO 46 19 35 24 / 10 0 0 0
F10 54 26 43 25 / 10 0 0 0
HHW 63 33 49 26 / 20 10 0 0
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...18
LONG TERM....05
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1104 AM CST WED FEB 11 2015
.AVIATION...
MVFR CIGS HAVE MOVED INTO ALL THREE TERMINALS LATE THIS MORNING
AND THEY SHOULD REMAIN INTO THE EVENING BEFORE RETURNING TO
VFR. WINDS WILL CONTINUE TO BE GUSTY INTO THIS EVENING AS WELL
WITH SUSTAINED WINDS AROUND 25 KTS WITH GUST TO 35 KTS. THEY WILL
LOWER TO LESS THAN 12 KTS AT ALL THREE TERMINALS AROUND 02Z. CDS
HAS THE BEST CHANCE OF SEEING LIGHT RAIN TODAY...HOWEVER CHANCES
ARE TOO LOW TO BE INCLUDED IN THE TAF AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 1049 AM CST WED FEB 11 2015/
UPDATE...
UPDATED POP GRIDS TO SCALE BACK RAIN CHANCES THROUGH LATE
AFTERNOON. WV IMAGERY SHOWS A SLOT OF DRY AIR PUSHING IN FROM THE
WEST WHICH IS HELPING TO KEEP PRECIP TO THE NORTH AND WEST OF THE
FA. RADAR RETURNS FROM KLBB SHOW LIGHT PRECIP OVER THE TX
PANHANDLE REGION...HOWEVER THE KAMA RADAR SHOWS MUCH LESS COVERAGE
OVERHEAD SHOWING THAT MOST OF WHAT IS FALLING IS IN THE FORM OF
VIRGA THANKS TO DRY MID LEVELS. SO FAR THERE ARE NO AIRPORT OR
MESONET OBS THAT SHOW ANY FALLING PRECIP ACROSS THE PANHANDLE. AS
THE VIRGA WILL HELP WITH SOME TOP DOWN MOISTENING SLIGHT CHANCE
POPS HAVE BEEN KEPT IN FOR OUR NORTHERN AND WESTERN
COUNTIES...THOUGH IT IS UNKNOWN IF THAT WILL EVEN BE ENOUGH TO
HELP RAIN REACH THE GROUND.
PREV DISCUSSION... /ISSUED 404 AM CST WED FEB 11 2015/
SHORT TERM...
NORTHERLY WIND SHIFT HAS PUSHED THROUGH ALREADY BUT STRONGER
PRESSURE GRADIENT STILL AWAITS WITH MAIN COLD AIR ADVECTION LATER
THIS MORNING INTO THE EARLY AFTERNOON. MOST RECENT RAP AND HRRR RUNS
SEEM TO SUPPORT WIND SPEEDS NEAR OR JUST SHY OF WIND ADVISORY
LEVELS. A WEAK UPPER LOW MEANWHILE EXPECTED TO PINCH OFF ACROSS THE
SOUTHERN ROCKIES LATER TODAY WHILE DROPPING SOUTHWARD. BEST LIFT AND
MOISTURE APPEAR TO REMAIN JUST TO OUR WEST...BUT PERHAPS ENOUGH LIFT
WITH MEAGER MOISTURE LAYERS TO SUPPORT LOW CHANCES OF LIGHT RAIN OR
SHOWERS MAINLY WESTERN AND CENTRAL ZONES AT LEAST THIS AFTERNOON AND
EARLY EVENING. LATEST SOLUTIONS HAVE TRIMMED BETTER PRECIPITATION A
BIT FURTHER WEST OF PREVIOUS FORECAST AND WE HAVE FOLLOWED THIS
TREND AS WELL. DRYING AND SUBSIDENT AIRMASS SHOULD GRADUALLY TAKE
BACK OVER OVERNIGHT. RECENT TEMPERATURE GUIDANCE REASONABLY SIMILAR
TO PREVIOUS WITH ONLY MINOR CHANGES. RMCQUEEN
LONG TERM...
DRY NORTHWEST FLOW WILL SET UP THURSDAY INTO THE WEEKEND BETWEEN
WEST COAST RIDGING EXTENDING INTO THE YUKON/NORTHWEST TERRITORIES
AND LOCKED IN CYCLONIC FLOW ACROSS EASTERN NORTH AMERICA. SURFACE
RIDGING WILL SLIDE EAST INTO THE MIDWEST THURSDAY AS LEE TROUGHING
TAKES FORM IN THE FRONT RANGE BEFORE EJECTING INTO THE PLAINS FRIDAY
BRINGING A NORTHERLY WIND SHIFT TO THE SOUTH PLAINS. ANY SEMBLANCE
OF COOLER AIR WILL REMAIN BOTTLED UP SEVERAL HUNDRED MILES TO THE
NORTHEAST...ALLOWING THE WARMING TREND TO CONTINUE INTO THE WEEKEND.
AFTER TEMPERATURES TOPPING OUT NEAR NORMAL IN THE 50S THURSDAY...A
STEADY RISE INTO THE 60S AND 70S WILL BE ON DECK FOR FRIDAY AND
SATURDAY RESPECTIVELY. A BACKDOOR FRONT WILL PUSH THROUGH THE PLAINS
SATURDAY AS YET ANOTHER LOBE OF ENERGY ROTATES AROUND A LOW ANCHORED
IN VICINITY OF HUDSON BAY...ARRIVING SOMETIME EARLY SUNDAY AND
LIKELY RESULTING IN A DECENT NORTHEAST TO SOUTHWEST TEMPERATURE
GRADIENT WITH HIGHS RANGING FROM THE UPPER 50S IN THE FAR SOUTHEAST
PANHANDLE TO NEAR 70 IN THE SOUTHWEST SOUTH PLAINS.
A SIGNIFICANT PATTERN CHANGE CONTINUES TO LOOM FOR EARLY NEXT WEEK
WITH BACKING UPPER FLOW DOWNSTREAM OF AN UPPER LOW...ORIGINATING
FROM A LOW OFF BAJA PHASING WITH THE RETROGRADE CUTOFF LOW
RESPONSIBLE FOR TODAY/S FRONT...AND SHORTWAVE TROUGH MIGRATING
SOUTHEASTWARD OUT OF WESTERN CANADA. MOISTURE ADVECTION LOOKS TO
HAVE LONG ENOUGH OF A RESIDENCE TIME FOR PRECIPITATION TO BECOME A
POSSIBILITY BY LATE MONDAY INTO TUESDAY AT THIS JUNCTURE. THIS LOOKS
TO BE WHEN NWP SOLUTIONS BEST CONVERGE ON UPPER SUPPORT COMBINING
WITH FRONTOGENETICAL FORCING FROM WHAT AT THIS POINT LOOKS TO BE A
STOUT FRONT...SERVING AS A REMINDER THAT FEBRUARY IS INDEED WINTER
IN THE NORTHERN HEMISPHERE. OVERALL TRENDS HAVE BEEN SHOWING THIS
PATTERN DEVELOPING WITH EASTERN PACIFIC RIDGING BECOMING HIGHLY
AMPLIFIED ENOUGH TO ALLOW FOR A SIGNIFICANT DUMP OF COLD AIR THROUGH
THE CENTRAL CONUS. AS FAR AS PRECIPITATION TYPE...A MIX OF RAIN AND
SNOW INITIALLY TRANSITIONING TO ALL SNOW SEEMS VALID GIVEN THIS
EXPECTED PUNCH OF CANADIAN AIR LASTING INTO MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 43 26 55 30 / 20 10 0 0
TULIA 47 28 54 30 / 20 10 0 0
PLAINVIEW 49 28 54 30 / 10 10 0 0
LEVELLAND 50 30 54 31 / 10 20 0 0
LUBBOCK 51 30 54 31 / 10 10 0 0
DENVER CITY 50 31 54 30 / 20 30 0 0
BROWNFIELD 50 31 54 31 / 10 30 0 0
CHILDRESS 56 30 53 32 / 0 10 0 0
SPUR 53 31 53 31 / 0 10 0 0
ASPERMONT 57 33 52 33 / 0 10 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
51/93/51
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1049 AM CST WED FEB 11 2015
.UPDATE...
UPDATED POP GRIDS TO SCALE BACK RAIN CHANCES THROUGH LATE
AFTERNOON. WV IMAGERY SHOWS A SLOT OF DRY AIR PUSHING IN FROM THE
WEST WHICH IS HELPING TO KEEP PRECIP TO THE NORTH AND WEST OF THE
FA. RADAR RETURNS FROM KLBB SHOW LIGHT PRECIP OVER THE TX
PANHANDLE REGION...HOWEVER THE KAMA RADAR SHOWS MUCH LESS COVERAGE
OVERHEAD SHOWING THAT MOST OF WHAT IS FALLING IS IN THE FORM OF
VIRGA THANKS TO DRY MID LEVELS. SO FAR THERE ARE NO AIRPORT OR
MESONET OBS THAT SHOW ANY FALLING PRECIP ACROSS THE PANHANDLE. AS
THE VIRGA WILL HELP WITH SOME TOP DOWN MOISTENING SLIGHT CHANCE
POPS HAVE BEEN KEPT IN FOR OUR NORTHERN AND WESTERN
COUNTIES...THOUGH IT IS UNKNOWN IF THAT WILL EVEN BE ENOUGH TO
HELP RAIN REACH THE GROUND.
&&
.PREV DISCUSSION... /ISSUED 545 AM CST WED FEB 11 2015/
AVIATION...
WIND SPEEDS EXPECTED TO INCREASE BY MID TO LATE MORNING AS TIGHTER
SURFACE PRESSURE PACKING MOVES IN. SOLUTIONS HAVE TRENDED A BIT
LESS CERTAIN WITH AN MVFR CLOUD DECK FOR KCDS TODAY...BUT THIS
STILL SEEMS LIKELY FOR KPVW AND KLBB THOUGH A BIT DELAYED. RAIN
CHANCES TOO UNCERTAIN AT EITHER KPVW OR KLBB...BETTER TO THE
WEST...FOR INCLUSION. CLOUDS SHOULD THIN TONIGHT. RMCQUEEN
PREV DISCUSSION... /ISSUED 404 AM CST WED FEB 11 2015/
SHORT TERM...
NORTHERLY WIND SHIFT HAS PUSHED THROUGH ALREADY BUT STRONGER
PRESSURE GRADIENT STILL AWAITS WITH MAIN COLD AIR ADVECTION LATER
THIS MORNING INTO THE EARLY AFTERNOON. MOST RECENT RAP AND HRRR RUNS
SEEM TO SUPPORT WIND SPEEDS NEAR OR JUST SHY OF WIND ADVISORY
LEVELS. A WEAK UPPER LOW MEANWHILE EXPECTED TO PINCH OFF ACROSS THE
SOUTHERN ROCKIES LATER TODAY WHILE DROPPING SOUTHWARD. BEST LIFT AND
MOISTURE APPEAR TO REMAIN JUST TO OUR WEST...BUT PERHAPS ENOUGH LIFT
WITH MEAGER MOISTURE LAYERS TO SUPPORT LOW CHANCES OF LIGHT RAIN OR
SHOWERS MAINLY WESTERN AND CENTRAL ZONES AT LEAST THIS AFTERNOON AND
EARLY EVENING. LATEST SOLUTIONS HAVE TRIMMED BETTER PRECIPITATION A
BIT FURTHER WEST OF PREVIOUS FORECAST AND WE HAVE FOLLOWED THIS
TREND AS WELL. DRYING AND SUBSIDENT AIRMASS SHOULD GRADUALLY TAKE
BACK OVER OVERNIGHT. RECENT TEMPERATURE GUIDANCE REASONABLY SIMILAR
TO PREVIOUS WITH ONLY MINOR CHANGES. RMCQUEEN
LONG TERM...
DRY NORTHWEST FLOW WILL SET UP THURSDAY INTO THE WEEKEND BETWEEN
WEST COAST RIDGING EXTENDING INTO THE YUKON/NORTHWEST TERRITORIES
AND LOCKED IN CYCLONIC FLOW ACROSS EASTERN NORTH AMERICA. SURFACE
RIDGING WILL SLIDE EAST INTO THE MIDWEST THURSDAY AS LEE TROUGHING
TAKES FORM IN THE FRONT RANGE BEFORE EJECTING INTO THE PLAINS FRIDAY
BRINGING A NORTHERLY WIND SHIFT TO THE SOUTH PLAINS. ANY SEMBLANCE
OF COOLER AIR WILL REMAIN BOTTLED UP SEVERAL HUNDRED MILES TO THE
NORTHEAST...ALLOWING THE WARMING TREND TO CONTINUE INTO THE WEEKEND.
AFTER TEMPERATURES TOPPING OUT NEAR NORMAL IN THE 50S THURSDAY...A
STEADY RISE INTO THE 60S AND 70S WILL BE ON DECK FOR FRIDAY AND
SATURDAY RESPECTIVELY. A BACKDOOR FRONT WILL PUSH THROUGH THE PLAINS
SATURDAY AS YET ANOTHER LOBE OF ENERGY ROTATES AROUND A LOW ANCHORED
IN VICINITY OF HUDSON BAY...ARRIVING SOMETIME EARLY SUNDAY AND
LIKELY RESULTING IN A DECENT NORTHEAST TO SOUTHWEST TEMPERATURE
GRADIENT WITH HIGHS RANGING FROM THE UPPER 50S IN THE FAR SOUTHEAST
PANHANDLE TO NEAR 70 IN THE SOUTHWEST SOUTH PLAINS.
A SIGNIFICANT PATTERN CHANGE CONTINUES TO LOOM FOR EARLY NEXT WEEK
WITH BACKING UPPER FLOW DOWNSTREAM OF AN UPPER LOW...ORIGINATING
FROM A LOW OFF BAJA PHASING WITH THE RETROGRADE CUTOFF LOW
RESPONSIBLE FOR TODAY/S FRONT...AND SHORTWAVE TROUGH MIGRATING
SOUTHEASTWARD OUT OF WESTERN CANADA. MOISTURE ADVECTION LOOKS TO
HAVE LONG ENOUGH OF A RESIDENCE TIME FOR PRECIPITATION TO BECOME A
POSSIBILITY BY LATE MONDAY INTO TUESDAY AT THIS JUNCTURE. THIS LOOKS
TO BE WHEN NWP SOLUTIONS BEST CONVERGE ON UPPER SUPPORT COMBINING
WITH FRONTOGENETICAL FORCING FROM WHAT AT THIS POINT LOOKS TO BE A
STOUT FRONT...SERVING AS A REMINDER THAT FEBRUARY IS INDEED WINTER
IN THE NORTHERN HEMISPHERE. OVERALL TRENDS HAVE BEEN SHOWING THIS
PATTERN DEVELOPING WITH EASTERN PACIFIC RIDGING BECOMING HIGHLY
AMPLIFIED ENOUGH TO ALLOW FOR A SIGNIFICANT DUMP OF COLD AIR THROUGH
THE CENTRAL CONUS. AS FAR AS PRECIPITATION TYPE...A MIX OF RAIN AND
SNOW INITIALLY TRANSITIONING TO ALL SNOW SEEMS VALID GIVEN THIS
EXPECTED PUNCH OF CANADIAN AIR LASTING INTO MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 43 26 55 30 / 20 10 0 0
TULIA 47 28 54 30 / 20 10 0 0
PLAINVIEW 49 28 54 30 / 10 10 0 0
LEVELLAND 50 30 54 31 / 10 20 0 0
LUBBOCK 51 30 54 31 / 10 10 0 0
DENVER CITY 50 31 54 30 / 20 30 0 0
BROWNFIELD 50 31 54 31 / 10 30 0 0
CHILDRESS 56 30 53 32 / 0 10 0 0
SPUR 53 31 53 31 / 0 10 0 0
ASPERMONT 57 33 52 33 / 0 10 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
51/93
AREA FORECAST DISCUSSION
NWS RIVERTON WY
246 PM MST WED FEB 11 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 211 PM MST WED FEB 11 2015
TONIGHT-THURSDAY:
LATEST WATER VAPOR LOOP WAS SHOWING THE UPPER LEVEL RIDGE
CONTINUING TO DOMINATE THE REGION. HOWEVER...THERE IS SOME CIRRUS
BEGINNING TO SPILL OVER THE RIDGE WHICH IS EXPECTED TO MOVE OVER
THE AREA BEGINNING TONIGHT AND CONTINUING THROUGH TOMORROW. THIS
MAY TEND TO RESTRICT TEMPERATURES A BIT TOMORROW...BUT IT SHOULD
STILL BE A NICE DAY WITH FAIRLY LIGHT WIND SPEEDS. WE MAY STILL
NEED TO CONTEND WITH SOME VALLEY FOG...BUT THE CIRRUS WILL TEND TO
LIMIT THAT POTENTIAL.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 211 PM MST WED FEB 11 2015
THURSDAY NIGHT-FRIDAY NIGHT:
NO SIGNIFICANT CHANGES ARE PLANNED THROUGH THIS PERIOD EITHER WITH
MILD TEMPERATURES AND LIGHT WIND SPEEDS CONTINUING DUE TO THE
INFLUENCE OF THE UPPER LEVEL RIDGE IN ROCKIES. WE MAY SEE ENOUGH
MOISTURE AND UPSLOPE FLOW TO GENERATE A FEW RAIN OR SNOW SHOWERS
IN YELLOWSTONE OR THE TETONS...BUT NOT EXPECTING ANYTHING MORE
THAN A DUSTING.
SATURDAY-WEDNESDAY:
THINGS BECOME A LOT MORE ACTIVE AS WE APPROACH SUNDAY INTO SUNDAY
NIGHT. THIS IS DUE TO A STRONG JET DIGGING SOUTH FROM BRITISH
COLUMBIA. MEANWHILE...ANOTHER STRONG UPPER LEVEL JET IN THE
NORTHERN PLAINS BEGINS TO DEPART THE REGION SUNDAY AFTERNOON INTO
SUNDAY NIGHT. THIS DEPARTING JET WILL PUT US UNDER THE INFLUENCE
OF THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL JET BEGINNING
SUNDAY AFTERNOON. THERE WILL BE SOME WEAK CONDITIONAL INSTABILITY
IN THE MOUNTAINS...BUT THERE COULD BE SOME GOOD INERTIAL
INSTABILITY IN THE SOUTHERN HALF OF THE FORECAST AREA WHICH MAY
PROMOTE SOME WIDELY SCATTERED RAIN SHOWERS SUNDAY AFTERNOON. THE
MAIN SHOW IS PROGGED TO SETUP SUNDAY NIGHT INTO MONDAY MORNING AS
THE COLD FRONT BEGINS TO MOVE THROUGH THE AREA. IT APPEARS TO BE
ENOUGH LIFT TO PRODUCE SOME WIDESPREAD SNOW ESPECIALLY IF WE CAN
GET INFLUENCED BY A COUPLED JET SCENARIO. OTHERWISE...MUCH COLDER
AIR WILL BEGIN TO SETTLE INTO THE REGION ON MONDAY NIGHT INTO
TUESDAY AS THE ARCTIC HIGH MOVES IN. IN FACT...HIGHS MAY STRUGGLE
TO GET OUT OF THE TEENS ON TUESDAY WITH OVERNIGHT LOWS DROPPING
BELOW ZERO IN SOME OF THE VALLEYS TUESDAY NIGHT INTO WEDNESDAY
MORNING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1037 AM MST WED FEB 11 2015
PATCHY DENSE FOG IN THE VALLEY CONTINUES TO PLAGUE THE KCOD TAF
SITE THIS MORNING. THIS IS DUE TO GOOD UPVALLEY FLOW WHICH IS
CONTRIBUTING TO THE FOG. WE ARE NOT REAL CONFIDENT WHEN THIS FOG
WILL ERODE...BUT WE DID NOTICE THE VISIBILITY WAS TRYING TO
IMPROVE DURING THE LAST HOUR. HOWEVER...THE HRRR WAS CONTINUING TO
SHOW THE UPVALLEY FLOW CONTINUING DURING THE NEXT COUPLE OF HOURS.
AS A RESULT...WE WENT AHEAD AND KEPT THE VISIBILITY LOW THROUGH
ABOUT 20Z OR SO. MEANWHILE...THE KJAC/KRKS TAF SITES ARE SHOWING
MVFR CEILINGS BUT THESE CEILINGS IMPROVE PRETTY QUICKLY. THE REST
OF THE TAF SITES VFR CONDITIONS SHOULD PREVAIL WITH MAINLY LIGHT
AND VARIABLE WINDS. &&
.FIRE WEATHER...
ISSUED AT 211 PM MST WED FEB 11 2015
A RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE AREA AND BRING MAINLY
DRY AND MILD WEATHER THROUGH SATURDAY. TEMPERATURES WILL BE WELL
ABOVE NORMAL FOR THURSDAY AND FRIDAY. A GUSTY BREEZE WILL BLOW AT
TIMES ACROSS THE SOUTHWESTERN WIND CORRIDOR AND EAST OF THE
ABSAROKAS. RELATIVE HUMIDITY WILL LOWER SUBSTANTIALLY FOR THURSDAY
BUT WILL REMAIN ABOVE RED FLAG CRITERIA.
&&
.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COX
LONG TERM...COX
FIRE WEATHER...COX
AREA FORECAST DISCUSSION
NWS RIVERTON WY
1050 AM MST WED FEB 11 2015
.SHORT TERM...WEDNESDAY THROUGH FRIDAY NIGHT
ALL IN ALL FAIRLY QUIET IN THE SHORT TERM AS SPRING IN FEBRUARY
CONTINUES. A WEAK COLD FRONT SHOULD BE SOUTH OF THE STATE BY
MORNING. A FEW CONVECTIVE SHOWERS DEVELOPED WITH THE UNSTABLE
NORTHWESTERLY FLOW AND THESE ARE ENDING OR MOVING AWAY. BY
MORNING...OTHER THAN MAYBE A LEFTOVER SHOWER IN THE BIG HORN
RANGE...MOST AREAS SHOULD BE DRY BY DAYBREAK. THERE COULD ALSO BE A
BIT OF FOG AROUND EARLY WHERE THE SHOWERS FELL. OTHERWISE...NO
CONCERNS AS RIDGING MOVES ACROSS THE STATE AND BRINGS INCREASING
AMOUNTS OF SUNSHINE. TEMPERATURES WILL BE A FEW DEGREES COLDER...BUT
STILL WARM FOR MID FEBRUARY.
MAINLY QUIET WEATHER WILL CONTINUE THROUGH THE END OF THE WORKWEEK
AS WELL. 700 MILLIBAR WINDS INCREASE FOR THURSDAY SO SOME OF THE
NORMALLY WINDIER SPOTS LIKE THE SOUTHWEST WIND CORRIDOR AND EAST OF
THE ABSAROKAS COULD SEE SOME GUSTY WINDS THURSDAY OR FRIDAY.
OTHERWISE...NO REAL CONCERNS. A WEAK SHORTWAVE MOVES ACROSS THURSDAY
BUT WITH NO MOISTURE TO WORK WITH WE EXPECT ONLY SOME CLOUDS. FRIDAY
ALSO LOOKS MAINLY DRY. TEMPERATURES WILL CONTINUE TO BE WELL ABOVE
AVERAGE WITH HIGHS IN THE 50S COMMONPLACE ACROSS THE LOWER
ELEVATIONS. HOWEVER...DO NOT GET USED TO IT. AS CLASSIC ROCKER DAVID
BOWIE SAID...THERE WILL BE CH-CH-CH CHANGES TO THE WEATHER PATTERN
LATER THIS WEEKEND. MORE ON THAT IN THE LONG TERM DISCUSSION.
.LONG TERM...SATURDAY THROUGH WEDNESDAY
...MUCH COLDER TEMPERATURES AND SNOW ON THE WAY SUNDAY NIGHT INTO TUESDAY...
SYNOPSIS...THE AREA WILL HAVE ONE MORE DAY OF UNSEASONABLY MILD AND DRY
WEATHER ON SATURDAY. A FAST-MOVING DISTURBANCE ACROSS THE NORTHERN
ROCKIES WILL BRING SOME SNOW SHOWERS ACROSS THE NORTHERN MOUNTAINS
SATURDAY NIGHT. CHANCES OF SNOW WILL INCREASE ACROSS THE AREA
SUNDAY AND SUNDAY NIGHT AS A MORE POTENT SYSTEM DIGS SOUTH INTO
THE GREAT BASIN. THIS SYSTEM WILL PULL A CANADIAN COLD FRONT SOUTH
ACROSS WYOMING SUNDAY NIGHT ACCOMPANIED BY GUSTY NORTH WIND AND
SNOW. SNOW IS EXPECTED TO TAPER OFF FROM THE NORTH TUESDAY AS A
DEEPER ARCTIC AIRMASS SETTLES IN. DRY AND COLD CONDITIONS ARE
EXPECTED WEDNESDAY.
DISCUSSION...MEDIUM-RANGE GLOBAL MODELS ALONG WITH ECMWF AND GFS
ENSEMBLE MEANS HAVE ALL LATCHED ON TO A ARCTIC INTRUSION EARLY
NEXT WEEK WITH LESS AGREEMENT AT MID-WEEK ON HOW FAST TO PUSH THE
ARCTIC AIRMASS OUT OF THE AREA. FAST-MOVING SHORTWAVE CRASHES INTO
UPPER RIDGE OVER THE INTERMOUNTAIN WEST ON SATURDAY. MOST
PRECIPITATION EXPECTED TO STAY NORTH OF WYOMING WITH THIS
SYSTEM...BUT IT IS EXPECTED TO KICK UP THE WINDS THROUGH THE DAY
SATURDAY INTO SATURDAY NIGHT. A SHARP UPPER RIDGE IS EXPECTED TO
BUILD OFF THE WEST COAST ON SUNDAY FORMING A HIGH AMPLITUDE RIDGE
REACHING DEEP INTO THE ARCTIC ON MONDAY. POLAR JET STREAM IS
EXPECTED TO EXTEND FROM NORTHERN ALASKA/YUKON WEST OF THE DIVIDE
INTO THE GREAT BASIN ON MONDAY...CARVING OUT LONGWAVE TROUGH
ACROSS THE ROCKIES. THE BEST SETUP FOR HEAVIER SNOW WILL BE SUNDAY
NIGHT INTO MONDAY WITH POSSIBILITY OF BAROCLINIC LEAF FORMING OVER
SURFACE FRONT. H5 -30 ISOTHERM IS EXPECTED TO PUSH SOUTH ACROSS
THE AREA MONDAY AFTERNOON...OR TOO COLD TO HOLD MUCH MOISTURE WITH
SNOW BECOMING LIGHT. 1045 MB ARCTIC HIGH PRESSURE WILL BUILD IN TO
THE AREA ON TUESDAY ALONG WITH H7 TEMPS -20C OR COLDER...SO HIGHS
ON TUESDAY WILL LIKELY STRUGGLE TO GET OUT OF THE SINGLE DIGITS.
FORECAST HAS BEEN TRENDED IN THIS DIRECTION FROM PREVIOUS MODEL
RUNS THAT KEPT THE ARCTIC AIR MOSTLY TO THE EAST. WOULD LIKE TO
SEE SOME CONTINUITY IN NEXT SET OR TWO OF MODEL RUNS TO GO FULL
ARCTIC BLAST FOR TUESDAY. RIGHT NOW FORECAST HAS MOST HIGHS IN THE
TEENS EAST OF THE DIVIDE ON TUESDAY. GFS EXPANDS RIDGE OFF THE
WEST COAST EAST INTO THE ROCKIES ON WEDNESDAY WHILE ECMWF
MAINTAINS SHARPER RIDGE ALONG THE WEST COAST AND KEEPS COLD ARCTIC
AIRMASS OVER WYOMING. FORECAST ALLOWS FOR SOME MODERATION OF
TEMPERATURES ON WEDNESDAY...OR A COMPROMISE BETWEEN THE TWO
EXTREMES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1037 AM MST WED FEB 11 2015
PATCHY DENSE FOG IN THE VALLEY CONTINUES TO PLAGUE THE KCOD TAF
SITE THIS MORNING. THIS IS DUE TO GOOD UPVALLEY FLOW WHICH IS
CONTRIBUTING TO THE FOG. WE ARE NOT REAL CONFIDENT WHEN THIS FOG
WILL ERODE...BUT WE DID NOTICE THE VISIBILITY WAS TRYING TO
IMPROVE DURING THE LAST HOUR. HOWEVER...THE HRRR WAS CONTINUING TO
SHOW THE UPVALLEY FLOW CONTINUING DURING THE NEXT COUPLE OF HOURS.
AS A RESULT...WE WENT AHEAD AND KEPT THE VISIBILITY LOW THROUGH
ABOUT 20Z OR SO. MEANWHILE...THE KJAC/KRKS TAF SITES ARE SHOWING
MVFR CEILINGS BUT THESE CEILINGS IMPROVE PRETTY QUICKLY. THE REST
OF THE TAF SITES VFR CONDITIONS SHOULD PREVAIL WITH MAINLY LIGHT
AND VARIABLE WINDS. &&
.FIRE WEATHER...
A RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE AREA AND BRING MAINLY
DRY AND MILD WEATHER THROUGH FRIDAY. TEMPERATURES WILL BE A FEW
DEGREES COOLER TODAY BEHIND A WEAK COLD FRONT...BUT STILL QUITE MILD
FOR FEBRUARY. TEMPERATURES WILL BE WELL ABOVE NORMAL FOR THURSDAY
AND FRIDAY. A GUSTY BREEZE WILL BLOW AT TIMES ACROSS THE
SOUTHWESTERN WIND CORRIDOR AND EAST OF THE ABSAROKAS. RELATIVE
HUMIDITY WILL LOWER SUBSTANTIALLY FOR THURSDAY BUT REMAIN ABOVE
&&
.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HATTINGS
LONG TERM...AEM
AVIATION...COX
FIRE WEATHER...HATTINGS